Our paper presents a novel theory of weak crossover effects, based entirely on quantifier scope preferences and their consequences for variable binding. The structural notion of 'crossover' play no role. We develop a theory of scope preferences which ascribes a central role to the AGR-P System.

Trwaj¸a}cy na pocz¸a}tku XXI wieku globalny kryzys gospodarczy wymusza podejmowanie przez przedsiȩbiorstwa działań restrukturyzacyjnych. Zmiany te czȩsto wi¸a}ż¸a} siȩ z redukcj¸a} zatrudnienia i kształtowaniem nowych relacji z pracownikami. Outplacement stanowi wci¸a}ż mało popularn¸a} i słabo rozpoznawaln¸a} w Polsce koncepcjȩ odpowiedzialnego zarz¸adzania zwolnieniami pracowników, która pozwala na złagodzenie negatywnych skutków utraty pracy i na skrócenie okresu bezrobocia. Celem opracowania jest przybliżenie istoty i potencjału stosowania outplacementu w Polsce. Podjȩta krytyczna analiza literatury przedmiotu obejmuje wskazanie działań na rzecz antycypacji procesów restrukturyzacji i (...) funkcji zwolnień monitorowanych w ochronie kompetencji kluczowych przedsiȩbiorstw. Określeni zostali główni interesariusze outplacementu w skali regionalnej oraz możliwości organizacji outplacementu przez partnerstwa i pakty lokalne, czyli z udziałem podmiotów sektora komercyjnego, publicznego i pozarz¸adowego. Podsumowanie zawiera wnioski, co do możliwych działań praktycznych. ** The ongoing at the beginning of the XXI century global economic crisis forces companies to take over restructuring actions. These changes are often associated with the reduction of employment and shaping of the new contract agreements with employees. Outplacement continues to be weakly popular and poorly recognized in Poland. It is the concept of responsible management of redundancies, which allows to mitigate the negative effects of losing a job and reduce the period of unemployment. The aim of this paper is to describe the essence and potential of outplacement usage in Poland. Undertaken critical analysis of the literature indicate measures for anticipate restructuring and outplacement functions in the protection of key enterprises competencies. Outplacement key stakeholders at the regional level were specified. Possibilities of outplacement organization including the local partnerships and pacts were explored. In other words, the cooperation of the commercial, public and non-governmental sector entities. Summary include proposals for further practical actions. (shrink)

The modern global technological landscape is shaped by rapid advances and interconnectivity, leading to a complex ecosystem of innovation, competition and collaboration. Significant developments are being seen in artificial intelligence, telecommunications, biotechnology and energy technologies. Digitalization is redefining industries such as healthcare, transport and finance, while cross-border data flows and 5G infrastructure are accelerating global connectivity. Key players such as the United States, China and Japan are investing heavily in research and development, pushing the capabilities of AI and quantum (...) computing further. These nations have adopted strategic initiatives to increase their technological self-confidence and ensure that their companies remain at the forefront of innovation. The European Union is positioned as a distinct player in the global technological landscape, aiming to stimulate innovation while ensuring trust, privacy and sustainability. By leveraging its regulatory power, investing in digital infrastructure and increasing collaboration between Member States, the EU is seeking to increase its strategic autonomy and competitiveness in the face of rapid technological change. Romania has seen significant development in its technology sector over the past two decades. Driven by a combination of government support, a well-educated workforce and strategic positioning within the European Union, Romania is increasingly making its mark on the technology scene. This study provides an overview of current global technology trends and the state of technology resources in the European Union and in Romania in particular, analyzing the strengths and weaknesses of the sector and highlighting the opportunities and challenges ahead. (shrink)

Divus Augustus Pater. The cult of divine Augustus under the rule of the Julio-Claudian dynasty -/- Summary The cult of divine Augustus was one of the most important phenomena of ideological nature under the rule of the Julio-Claudian dynasty. The crucial point of its development was the apotheosis conducted on 17 September 14 AD. The new cult was derived greatly from numerous borrowings from the rites of various gods of the Roman Pantheon. As divus, Augustus received a separate priest, a (...) private priestess, and a college of priests. The first flamen Augustalis became Germanicus. The holder of this title enjoyed many privileges. It seems unlikely, however, that flamen Augustalis controlled the entire cult of divine Augustus. This was the role of the emperor as both the supreme priest and the inheritor of political power. Sodales Augustales also had special cult functions. This religious fraternity had a mixed private-state character just like many of the institutions of the early principate. It was a cult college of gens Iulia and, most of all, of Augustus. From its beginning it enjoyed high prestige. The members of this religious fraternity were recruited among the Senate elite and the family of the emperor. Sacerdos divi Augusti occupies a different place in the priesthood established to worship Augustus. This female priesthood, despite its humble cult and political role, is of great interest to scholars. In spite of discerning investigations by researchers, there seem to have been only two priestesses in the Julio-Claudian dynasty – Julia Augusta, the widow of the creator of the principate, and Antonia Augusta. There is even no certainty that the latter had preformed the function at all. Augustus, as a god, was given a separate temple under a Senate decree. However, the construction work went slowly ahead. Therefore, divus Augustus was initially worshipped in other places of worship. At first, it was the temple of Mars Ultor. He was also worshipped in the sacrarium on the Palatine. One encounters certain difficulties when trying to identify the places of Augustus’ worship in Rome. Ultimately, there seem to have been two sacraria in the capital of the Empire. There is no certainty, however, whether yet another temple was located next to the templum novum divi Augusti on the Palatine. In trying to analyse the phenomenon of the divinity of the Roman emperors, and Augustus in particular, it is necessary to refer to the genesis of Emperor worship. Within the framework of official religion it is important to distinguish such elements as genius and numen. Although the consecratio act conducted by the Senate meant the crossing of the boundary between the human Augustus and the divine Augustus, it is important to remember that Augustus had prepared his apotheosis for a long time and already enjoyed divine honours during his lifetime. Certain elements of Augustus worship developed under his rule continued to exist for some time after the death of the creator of the principate. Augustus divinity was guarded by the law of maiestas. At the beginning of the rule of Tiberius it mostly protected divus Augustus himself. Gradually, despite some opposition, the law began to serve the ruling emperor. There is little certainty of how many cases were brought under the crimen laesae maiestatis against those who insulted the divine Augustus. The issue of trials for offending the law of maiestas is accounted for one-sidedly by ancient historians, which complicates the work of contemporary researchers. There is, however, no denying that for Tiberius (Augustus’ successor) the trials on the charge of maiestas turned out to be a trap. The cult of divus Augustus was approved throughout the Empire. Nevertheless, some weaker voices of opposition could be heard. These were present in the Senate circles cherishing the memory of the last defenders of the Republic, as well as among some ethnic and religious communities. The latter included Judaism and emerging Christianity. The political consequences of Augustus’ deification were very serious. He significantly contributed to the ruling of the Julio-Claudian dynasty for over 50 years. The main reason for that was the fact that in the Rome of that time the tradition of power succession was not yet well-grounded. Directly after the principate creator’s death, his consecratio took place – he was assigned priests and many godly honours and a temple was erected in his honour. These actions obviously took place under Augustus’ successor Tiberius who, during his rule, constantly tried to emulate the divine predecessor and referred to his decrees on numerous occasions. Tiberius was the emperor who contributed to the cult of his adoptive father to the greatest extent. However, one cannot fail to notice that his actions were somehow ambiguous. It has to be remembered that, in addition to his sincere respect for the divine Augustus, Tiberius also tried to use the authority of the creator of the principate to strengthen his power. This is exemplified by the motto imprinted on coins: DIVVS AVGVSTVS PATER. Caligula took a different approach to the Augustan cult. When assuming power after Tiberius, he was in a different position. The 20-year rule by Augustus’ successor greatly contributed to the strengthening of the idea of the principate ’s stability in the minds of the Romans. This allowed Caligula to pay less heed to the Senate aristocracy, as well as other institutional elements of the Republic. Under these circumstances, the cult of Augustus underwent modifications. Divus Augustus still remained at the heart of the religious propaganda of the Roman state and gens Iulia, but also other members of the family of the young Emperor received a number of honours drawing them closer to the world of gods. Drusilla, for that matter, was made a diva. By this, the idea of domus Augusta received a new confirmation. Caligula himself did not cease to participate in, and support, the rites performed to worship his divine grandfather. The available sources lead us to believe that Augustus constituted for the young princeps a role model and a character to which he often compared himself with. For Claudius, the use of the cult of divine Augustus was important as a tool to strengthen political power. But due to the fact that his personal links with divus Augustus were rather weak, Claudius focused on the cult of his grandmother Livia, Augustus’ wife. He also emphasised the function of sacerdos divi Augusti which his mother Antonia Augusta was to fulfil. Claudius faced the task of the ‘reconstruction’ of the cult of Augustus which had deteriorated, especially during the second part of Caligula’s rule. Claudius took a different direction in imitating Augustus than his two predecessors. Augustus’ model was very capacious, allowing him to find examples which could be adjusted to fit his own political goals and personality. Claudius avoided the stiffness characteristic of Tiberius and, at the same time, respected Augustus’ traditions which he Caligula inadvertently abused. Claudius’ attitude to Augustus is not quite clear. Undoubtedly he kept alive the memory of the first princeps, however, there is a lack of testimony about the new honours conferred on divine Augustus during the rule of this Emperor. Almost all of them concentrate around the person of Claudius or his family. There are, however, no honours conferred on the creator of the principate. This type of attitude caused the cult of divine Augustus to be eclipsed by the cult of the ruling Emperor. Nero, the last representative of the Julio-Claudian dynasty descended, unlike Claudius, directly from the line of Augustus. The new emperor deified his predecessor by using the model of Augustus’ apotheosis. In the first part of his rule he drew greatly from the Augustus model of exercising power. Nero ’s ideological platform seems to be the richest in comparison with other emperors of the Julio-Claudian dynasty. The tradition of links with divus Augustus was, however, only one of many different elements. With time, the tradition appeared to play a still smaller role. The departure from the Augustus model took place on many levels. Some of the steps were very radical, whereas others were less significant. The most serious was the elimination of the members of gens Iulia and gens Claudia, and those who could prove their kinship with both the houses. The devastation in Nero ’s closest family put an end to the concept of domus Augusta. Formally, the Emperor did not renounce the divine creator of the principate but, in practice, the idea of the new domus Augusta no longer aimed at presenting Augustus’ descendants united in a single family. Nero was now alone and any creation of ideological concepts of power under those circumstances had to be based around him. These actions ended in disaster. By giving up the Augustan model, Nero lost the support of the army and, as a result, lost power. Apart from the worship of the state religion in the capital, divus Augustus was the subject of a provincial and municipal cult. Here, the worship of divine Augustus was often a continuation, sometimes in an extended form, of the honours Augustus had been granted during his lifetime. In the cult of divus Augustus, in the provinces one can observe a mutual interweaving of elements copied from the capital model and local traditions. The beginning of the provincial cult of Augustus dates back to the rule of Tiberius. The crucial point for the establishment of the provincial cult in the West was the request of the citizens of Hispania Tarraconensis to build a temple for divine Augustus. It is important to emphasise here that he was appointed on a local initiative. In the East, the genesis of the provincial cult is related to the functioning of koinon. In comparison with the western regions, the cult here was characterised not only by longer history but also an extensive system of priesthood and rich ritual. The intensity of development of municipal and private cult in the West depended on the level of social and economic development of the regions. It assumed the most complex forms in the provinces with well-developed city life – generally in the eastern provinces. Whereas the cult of divine Augustus in the western municipal provinces was similar in character to the cult of the principate’s creator in Italy. The greatest testimony to the cult’s development comes from relatively strongly romanised and, at the same time, the wealthiest regions which had been part of the Empire for a long time. These included the mainly proconsular Africa, Spain and Narbonese Gaul. The sources coming from these regions constitute not only an illustration of the development of the cult of divine Augustus and members of domus Augusta, but are also a sign of the processes of romanisation of great numbers of city populations. It is necessary to note that outside Rome we do not encounter an isolated cult of divine Augustus. Whenever we deal with information concerning temples or rituals dedicated to the deified creator of the principate, other members of the family are also worshipped. In fact, during the whole rule of the Julio-Claudian dynasty we actually deal with the cult of divine Augustus in close association with the worship of domus Augusta – domus divina. (shrink)

The phenomenon of weakness of will – not doing what we perceive as the best action – is not recognized by neoclassical economics due to the axiomatic assumptions of the revealed preference theory (RPT) that people do what is best for them. However, present bias shows that people have different preferences over time. As they cannot be compared by the utility measurements, economists need to normatively decide between selves (short- versus long-term preferences). A problem is that neoclassical economists perceive (...) RPT as value-free and incorporate present bias within the economic framework. The axiomatic assumption that people do what is best for them leads to theoretical and practical dilemmas. This work examines weakness of will to resolve some shortcomings of RPT. The concept of intention is used to provide multiple self conception with the framework to decide between selves, which had not been done before. The paper concludes that individuals should not always follow their revealed preferences (desires) but the intentions (reason) because the latter indicates what people really want. (shrink)

Feynman's sum-over-histories formulation of quantum mechanics has been considered a useful calculational tool in which virtual Feynman histories entering into a coherent quantum superposition cannot be individually measured. Here we show that sequential weak values, inferred by consecutive weak measurements of projectors, allow direct experimental probing of individual virtual Feynman histories, thereby revealing the exact nature of quantum interference of coherently superposed histories. Because the total sum of sequential weak values of multitime projection operators for a (...) complete set of orthogonal quantum histories is unity, complete sets of weak values could be interpreted in agreement with the standard quantum mechanical picture. We also elucidate the relationship between sequential weak values of quantum histories with different coarse graining in time and establish the incompatibility of weak values for nonorthogonal quantum histories in history Hilbert space. Bridging theory and experiment, the presented results may enhance our understanding of both weak values and quantum histories. (shrink)

Indirect speech reports can be true even if they attribute to the speaker the saying of something weaker than what she in fact expressed, yet not all weakenings of what the speaker expressed yield true reports. For example, if Anna utters ‘Bob and Carla passed the exam’, we can accurately report her as having said that Carla passed the exam, but we can not accurately report her as having said that either it rains or it does not, or that either (...) Carla passed the exam or pandas are cute. This paper offers an analysis of speech reports that distinguishes weakenings of what the speaker expressed that yield true reports from weakenings that do not. According to this analysis, speech reports are not only sensitive to the informational content of what the speaker expressed, but also to the possibilities a speaker raises in making an utterance. As I argue, this analysis has significant advantages over its most promising competitors, including views based on work by Barwise and Perry : 668–691, 1981), views appealing to recent work on the notion of content parthood by Fine :199–226, 2016) and Yablo, and Richard’s : 605–616, 1998) proposal appealing to structured propositions. (shrink)

The distinction between nature and artifice has been definitive for Western conceptions of the role of humans within their natural environment. But the human must already be separated from nature in order to distinguish between nature and artifice. This separation, in turn, facilitates a classification of knowledge in general, typically cast in terms of a hierarchy of sciences that ascends from the natural sciences to the social (or human) sciences. However, this hierarchy considers nature as a substantial foundation upon which (...) artifice operates and to which it responds. Here I examine three inter-related concepts that, by focusing on events rather than substances, operate beyond the nature–artifice distinction and thereby resist the hierarchical classification of the sciences: Foucault’s concept of technology, the concept of milieu as it crosses over historically from physics to biology and anthropology, and Deleuze and Guattari’s reconfiguration of the concept of milieu in terms of their concept of machine. (shrink)

Modifying the descriptive and theoretical generalizations of Relativized Minimality, we argue that a significant subset of weak island violations arise when an extracted phrase should scope over some intervener but is unable to. Harmless interveners seem harmless because they can support an alternative reading. This paper focuses on why certain wh-phrases are poor wide scope takers, and offers an algebraic perspective on scope interaction. Each scopal element SE is associated with certain operations (e.g., not with complements). When a (...) wh-phrase scopes over some SE, the operations associated with that SE are performed in its denotation domain. The requisite operations may or may not be available in a domain, however. We present an empirical analysis of a variety of wh-phrases. It is argued that the wh-phrases that escape all weak islands (i.e., can scope over any intervener) are those that range over individuals, the reason being that all Boolean operations are defined for their domain. Collectives, manners, amounts, numbers, etc. all denote in domains with fewer operations and are thus selectively sensitive to scopal interveners—a “semantic relativized minimality effect”. (shrink)

This paper examines the relations between stubbornness and weakness of will, adopting Holton’s definition of weakness of will as an over-readiness to revise one’s resolutions. It posits that both stubbornness and weakness of will are responses to pessimism – the negative perception of a task or its outcome. Contrary to naive judgement, stubbornness is not merely the opposite of weakness; rather, it serves as a preventive behaviour stemming from a fear of weakness of will. Weakness of will and stubbornness (...) can be viewed as two facets of the same phenomenon, both influenced by pessimism. The paper explores the implications of this unified account, particularly at the therapeutic level, suggesting that enhancing self and other trust could reduce both weak and stubborn behaviours. (shrink)

Ever since Machery et al. first decided to test whether non-philosophers assign reference in accordance with the causal-historical account, the reference of proper names has been tested by means of setups modelled on Kripke’s Gödel and Jonah cases. Over the years, the use of these setups as a means to test theories of reference has attracted much criticism. However, previous follow-up studies have supposedly accounted for these criticisms, for the most part without changing the original outcome. We conducted experiments (...) suggesting that participants’ responses in these setups never tracked what they are supposed to track. In our study, we tested the setup itself by using analogues of different setups modelled on Kripke’s Gödel and Jonah cases. Instead of proper names, our analogues featured terms for which we have independent reason to believe that the causal-historical account is not true. The analogues elicited large proportions of supposed causal-historical responses. (shrink)

In abstract algebraic logic, many systems, such as those paraconsistent logics taking inspiration from da Costa's hierarchy, are not algebraizable by even the broadest standard methodologies, as that of Blok and Pigozzi. However, these logics can be semantically characterized by means of non-deterministic algebraic structures such as Nmatrices, RNmatrices and swap structures. These structures are based on multialgebras, which generalize algebras by allowing the result of an operation to assume a non-empty set of values. This leads to an interest in (...) exploring the foundations of multialgebras applied to the study of logic systems. -/- It is well known from universal algebra that, for every signature Sigma, there exist algebras over Sigma which are absolutely free, meaning that they do not satisfy any identities or, alternatively, satisfy the universal mapping property for the class of Sigma-algebras. Furthermore, once we fix a cardinality of the generating set, they are, up to isomorphisms, unique, and equal to algebras of terms (or propositional formulas, in the context of logic). Equivalently, the forgetful functor, from the category of Sigma-algebras to Set, has a left adjoint. This result does not extend to multialgebras. Not only multialgebras satisfying the universal mapping property do not exist, but the forgetful functor U, from the category of Sigma-multialgebras to Set, does not have a left adjoint. -/- In this paper we generalize, in a natural way, algebras of terms to multialgebras of terms, whose family of submultialgebras enjoys many properties of the former. One example is that, to every pair consisting of a function, from a submultialgebra of a multialgebra of terms to another multialgebra, and a collection of choices (which selects how a homomorphism approaches indeterminacies), there corresponds a unique homomorphism, what resembles the universal mapping property. Another example is that the multialgebras of terms are generated by a set that may be viewed as a strong basis, which we call the ground of the multialgebra. Submultialgebras of multialgebras of terms are what we call weakly free multialgebras. Finally, with these definitions at hand, we offer a simple proof that multialgebras with the universal mapping property for the class of all multialgebras do not exist and that U does not have a left adjoint. (shrink)

We report two experiments exploring the perception of how contemporary philosophy is often conducted. We find that (1) participants associate philosophy with the practice of conducting thought experiments and collating intuitions about them, and (2) that this form of inquiry is viewed much less favourably than the typical form of inquiry in psychology: research conducted by teams using controlled experiments and observation. We also found (3) an effect whereby relying on intuition is viewed more favorably in the context of team (...) inquiry than in individual inquiry and (4) that greater prior exposure to philosophy lowered one’s opinion of inquiry driven by intuitions and thought experiments. Finally with respect to participant gender, we found that (5) women favored observation over intuition more than men did, and (6) tended to view a question pursued by a research team as more important than men viewed it. (shrink)

Recent trends in psychiatry involve a transition from categorical to dimensional frameworks, in which the boundary between health and pathology is understood as a difference in degree rather than as a difference in kind. A major tenet of dimensional approaches is that no qualitative distinction can be made between health and pathology. As a consequence, these approaches tend to characterize such a threshold as pragmatic or conventional in nature. However, dimensional approaches to psychopathology raise several epistemological and ontological issues. First, (...) we review major sources of evidence usually recruited in support of the dimensional trend (focusing on clinical observation and biological data), and we show that these are connected to different conceptualizations of how dimensional traits extend across health and pathology. Second, we criticize two unquestioned assumptions that stand at the core of the dimensional trend: a) that there is continuity from health to pathology at the symptomatic level; b) that such continuity reflects an underlying continuity in the genetic liability for pathological conditions. Third, we argue against the idea of a conventional threshold by showing that such a view implies a linear relationship between the genotype and the phenotype. Fourth, drawing on epigenetics and developmental biology, we offer a characterization of mental disorders as stable and dynamic constellations of multi-level variables that differ qualitatively from ‘healthy states’. We conclude by showing that our account has several theoretical advantages over both categorical and dimensional approaches. Notably, it provides crucial insights into psychological development over time and individual differences, with major implications in terms of intervention and clinical decision-making. (shrink)

Combinatory logic (Curry and Feys 1958) is a “variable-free” alternative to the lambda calculus. The two have the same expressive power but build their expressions differently. “Variable-free” semantics is, more precisely, “free of variable binding”: it has no operation like abstraction that turns a free variable into a bound one; it uses combinators—operations on functions—instead. For the general linguistic motivation of this approach, see the works of Steedman, Szabolcsi, and Jacobson, among others. The standard view in linguistics is that reflexive (...) and personal pronouns are free variables that get bound by an antecedent through some coindexing mechanism. In variable free semantics the same task is performed by some combinator that identifies two arguments of the function it operates on (a duplicator). This combinator may be built into the lexical semantics of the pronoun, into that of the antecedent, or it may be a free-floating operation applicable to predicates or larger chunks of texts, i.e. a typeshifter. This note is concerned with the case of cross-sentential anaphora. It adopts Hepple’s and Jacobson’s interpretation of pronouns as identity maps and asks how this can be extended to the cross-sentential case, assuming the dynamic semantic view of anaphora. It first outlines the possibility of interpreting indefinites that antecede non-ccommanded pronouns as existential quantifiers enriched with a duplicator. Then it argues that it is preferable to use the duplicator as a type-shifter that applies “on the fly”. The proposal has consequences for two central ingredients of the classical dynamic semantic treatment: it does away with abstraction over assignments and with treating indefinites as inherently existentially quantified. However, cross-sentential anaphora remains a matter of binding, and the idea of propositions as context change potentials is retained. (shrink)

This study adds to the existing literature on meaningful work by offering a cross-cultural perspective. Since work shapes the kind of person that we are and plays an important role in our well-being, some theorists have adopted a virtue theory approach to meaningful work using an Aristotelian-MacIntyrean framework. For lack of a better term, I will call this a western virtue theory. This paper presents a contemporary virtue-focused Buddhist perspective on the topic. While a virtue-ethics interpretation of Buddhism is (...) now widely accepted and has been applied to several issues, not much has been written about meaningful work using a Buddhist-Aristotelian comparative framework. Buddhism is an important cultural component not only of countries that are predominantly Buddhist, but of other societies that have come in contact with it. To develop a Buddhist framework, I draw heavily from the works of Buddhist scholars, particularly in the West who use a virtue framework in interpreting Buddhism. The aims of my essay are dual. The first is to articulate a straightforward application of Buddhism on the contemporary ethical discussion of meaningful work. The second is to discuss the similarities, clarify the differences, and demonstrate the strengths and weaknesses relative to each other of the Buddhist and the Western virtue theory perspectives. In my analysis, I will argue that consideration of Buddhist perspective will enable us to construct a cross-cultural, inclusive, and pluralistic conceptual model for the deliberation of meaningful work that complements the Western virtue theory. (shrink)

Over the past decade, many politicians and celebrities in North America have found themselves embroiled in scandals that involved them having worn black make-up and in at least one incident white make-up. In most of these cases, the used make-up was part of a costume for Halloween, Purim, Carnival, or a themed party. This article challenges the view that wearing cross-racial make-up on such occasions as part of personal costumes—as opposed to costumes that are integral to specific cultural (...) traditions, such as the New Orleans Zulu parade—is always wrong. To do so, it assesses the five most promising objections to this practice. Although some of these objections count against certain uses of cross-racial make-up, I show that in several high-profile cases where such make-up was worn, none of them had force, whether because the objections themselves were implausible and/or because they did not apply. (shrink)

The representational theory of phenomenal experience is often stated in terms of a supervenience thesis: Byrne recently characterises it as the thesis that “there can be no difference in phenomenal character without a difference in content”, while according to Tye, “[a]t a minimum, the thesis is one of supervenience: necessarily, experiences that are alike in their representational contents are alike in their phenomenal character.” Consequently, much of the debate over whether representationalism is true centres on purported counter-examples – that (...) is to say, purported failures of supervenience. The refutation of putative counter-examples has been, it seems to me, by and large successful. But there is a certain class of these for which the representationalist response has been something less than completely convincing. These are the cross-modality cases. I will explain what I mean, and then argue that the response in question is not only unconvincing but actually undermines the representationalist position. (shrink)

Concurring to information from the Centresfor Illness Control and Anticipation, instruction and religion are both capable indicators of lasting or dissolving unions. The chance of a marriage finishing in separate was lower for individuals with more knowledge, with over half of relational unions of those who did not complete high school having finished in separate compared with roughly 30 percent of relational unions of college graduates. With this overview, the divorce rate dataset from UCI dataset repository is used for (...) predicting the divorce class target with the following contributions. Firstly, the Divorce rate dataset is subjected with the data cleaning and exploratory data analysis. Secondly, the data set is settled with different classifiers to look at the classification before and after feature scaling. Thirdly, the dataset is processed with various cross validation of training and testing dataset i.e 80:20, 30:70, 40:60, 50:50 to improve the accuracy of all the classifiers. Fourth, the dataset is processed with 15, 20 and 30 components of principal component analysis and then applied with all classifier algorithm to analyze the accuracy of divorce rate prediction. Fifth, the performance analysis is done with precision, recall, accuracy, fscore and running time to infer the classification before and after feature scaling. Experimental results show that the Random Forest classifier is found to have the accuracy of 98% for all PCA reduced dataset with 15, 20 and 30 components. The result showsthat Random Forest classifier is found to have the accuracy of 98% for 40:60, 50:50 of training and testing dataset. (shrink)

Immanuel Kant’s notion of weakness or frailty warrants more attention, for it reveals much about his theory of motivation and general metaphysics of mind. As the first and least severe of the three grades of evil, frailty captures those cases where an agent fails to act on their avowed recognition that the moral law is the only legitimate determining ground of the will. The possibility of such cases raises many important questions that have yet to be settled by interpreters. Most (...) importantly, should we account for the failures of weakness by appealing to the activity of reason or sensibility? I will discuss this question in light of a tendency to adopt an overly dualistic reading of Kant’s moral psychology. Focusing on Kant’s remarks on weakness from the Religion and the Metaphysics of Morals, I argue that we should understand weakness as arising from the unique difficulties of sense-dependent judgment, rather than from self-deception, flagging commitment, or overwhelming desire. The resulting account offers a unified moral psychology capable of accommodating the many features of weakness that are difficult to reconcile on other readings. (shrink)

This paper defends an ontology of weak entity realism for homeostatic property cluster (HPC) theories of natural kinds, adapted from Bird’s (Synthese 195(4):1397–1426, 2018) taxonomy of such theories. Weak entity realism about HPC kinds accepts the existence of natural kinds. Weak entity realism denies two theses: that (1) HPC kinds have mind-independent essences, and that (2) HPC kinds reduce to entities, such as complex universals, posited only by metaphysical theories. Strong entity realism accepts (1) and (2), whereas (...) moderate entity realism accepts only (1). Given its commitment to (2), strong entity realism is more theoretically complex than weak entity realism, with little explanatory payoff. Given their commitment to (1), moderate and strong entity realisms cannot explain how the identity conditions of HPC kinds are to be straightforwardly knowable. I argue that weak entity realism avoids such epistemic difficulties. I further rebut two plausible criticisms of weak entity realism, namely that weak entity realism cannot account for quantification over kinds, and that weak entity realism cannot provide identity conditions for HPC kinds which are both scientifically useful and objective. Given the theoretical costs of strong and moderate entity realism, and weak entity realism’s adequate response to its most plausible challenges, weak entity realism about HPCs is to be preferred, especially for biological and chemical kinds. (shrink)

While spreading wide-world, the new coronavirus Sars-CoV-2 made changes in many social departments of our society on levels we never thought about and messes with all our cultural habits. Thus, we witnessed that the religious denominations took into consideration changes without precedent in their cultic history and thus dogmatic as well concerning the actual threat of Coronavirus. We saw for example the Roman-Catholic Church who suspended all masses here and there[1] at first or banned the crucial gestures in rituals [to (...) suspend the distribution of Holy Communion from the Chalice[2], to distribute the Eucharist preferably into the hands of the faithful, and to avoid the physical contact from a peaceful handshake, to forego ash crosses on forehead, to suspend placing water in holy water fonts at the entrance of churches, that the churchgoers "refrain" from kissing or touching the cross for veneration, or even cancellation of masses]. We witnessed Buddhist temples and Protestant churches around Korea [at first] and beyond that have also suspended religious gatherings, and so on. In my case, the Romanian Orthodox Church did the same thing[3], but in a controversial way, firstly making some recommendations for its believers [e.g. not to kiss public icons in Churches, but their indoor ones, and receive Holy Communion with teaspoons for single-use]; afterward same Church reconsidered these recommendations and withdrew its decision [perhaps at the pressure of civil fundamentalists]. How can we qualify all these measures and, moreover, the withdrawal on behalf of religious believers, as weakness, populism, diligence, assuming the human limits, or...something else? What would be the correct and coherent answer religion should assume in this particular regard, and especially what are the reasons to qualify it in a way or another? (shrink)

We investigate risk attitudes when the underlying domain of payoffs is finite and the payoffs are, in general, not numerical. In such cases, the traditional notions of absolute risk attitudes, that are designed for convex domains of numerical payoffs, are not applicable. We introduce comparative notions of weak and strong risk attitudes that remain applicable. We examine how they are characterized within the rank-dependent utility model, thus including expected utility as a special case. In particular, we characterize strong comparative (...) risk aversion under rank-dependent utility. This is our main result. From this and other findings, we draw two novel conclusions. First, under expected utility, weak and strong comparative risk aversion are characterized by the same condition over finite domains. By contrast, such is not the case under non-expected utility. Second, under expected utility, weak comparative risk aversion is characterized by the same condition when the utility functions have finite range and when they have convex range. By contrast, such is not the case under non-expected utility. Thus, considering comparative risk aversion over finite domains leads to a better understanding of the divide between expected and non-expected utility, more generally, the structural properties of the main models of decision-making under risk. (shrink)

Is morality uniquely human or does morality exist in at least some non-human animals? Are animals full-fledged moral creatures or do they merely exhibit proto-morality—evolutionary building blocks or precursors to morality, but not quite the genuine article? Such questions, prompted by remarkable advances in empirical research into the social and emotional lives of non-human animals, have aroused much recent interest amongst scientists, philosophers, and in the popular media, not least for their apparent bearing on questions of human uniqueness, evolution, and (...) the ethical status of animals. The debate over animal morality has produced many valuable contributions and stimulated new areas for empirical and theoretical research. However, focusing on these questions has led researchers to talk at cross-purposes and down some unproductive paths. The problem concerns the terms ‘morality’ and ‘moral’. (shrink)

How should we determine the distribution of psychological traits—such as Theory of Mind, episodic memory, and metacognition—throughout the Animal kingdom? Researchers have long worried about the distorting effects of anthropomorphic bias on this comparative project. A purported corrective against this bias was offered as a cornerstone of comparative psychology by C. Lloyd Morgan in his famous “Canon”. Also dangerous, however, is a distinct bias that loads the deck against animal mentality: our tendency to tie the competence criteria for cognitive capacities (...) to an exaggerated sense of typical human performance. I dub this error “anthropofabulation”, since it combines anthropocentrism with confabulation about our own prowess. Anthropofabulation has long distorted the debate about animal minds, but it is a bias that has been little discussed and against which the Canon provides no protection. Luckily, there is a venerable corrective against anthropofabulation: a principle offered long ago by David Hume, which I call “Hume’s Dictum”. In this paper, I argue that Hume’s Dictum deserves a privileged place next to Morgan’s Canon in the methodology of comparative psychology, illustrating my point through a discussion of the debate over Theory of Mind in nonhuman animals. (shrink)

Domestic courts are often quoting foreign case law on human rights. The conversation pursued through cross-referencing across jurisdictions has added to the globalization of international human rights standards. As the practice is gaining ground and becoming a more permanent feature of domestic judgments, its relevance needs to be examined. A closer look at the practice will bring forth a more realistic understanding of the approaches of domestic courts and the advantages which they offer to the institution. This paper raises (...) few questions on the value and influence of cross-referencing in the area of human rights. Questions in this regard can be posed as to (a) whether cross-referencing is reflective of an emerging consensus on the subject matter? (b) Is it strategic for domestic courts to quote foreign case law? (c) Is the practice of cross-referencing simply a trend or an urge to belong to a community of courts? (d) Is the practice of relevance towards the implementation and advancement of international human rights standards? The topic can shed light on broader themes including the universality of human rights, contestations/disagreements over human rights standards, and the measure of acceptability of international human rights standards within domestic settings. This paper discusses the practice, its role and influence in relation to international human rights standards. Three judgments [of the courts of Nepal, India and Singapore] addressing the human rights and homosexuality agenda have been illustrated for discussion. (shrink)

The movement of people from one country to another in search of greener pasture, peaceful settlement and so on, has become very rampant in the world today. These same reasons have triggered internal migrations as well. Lives have been lost in the bid to circumvent immigration laws of countries by immigrants. The current spate of wars, political crises, natural disasters and hunger has led to increase in illegal migration in the world. Nigeria is not left out. We hear of boundary (...) clashes and insurgencies, which have resulted in illegal emigration to other countries basically in search of job opportunities and better living conditions. Nigerians have severally been repatriated from foreign lands. Recently, over five thousand Nigerians were repatriated from Libya. Nigeria has also played host to migrants from neighbouring countries, and has experienced internal migration in several parts of the country. The frequently asked questions are: “what role can religion play in curbing the spate of illegal migration and refugee crises in Cross River State, Nigeria? The research discovered that religion can be a veritable partner to government in resolving this ever-increasing menace that has become an embarrassment to the state and nation. This work adopted qualitative or explorative research method. It employed the content analysis approach in examining available printed materials on the subject matter. In view of its peculiarity, oral interviews were conducted on specific groups and individuals. This work proposes the involvement of religious organisations in preaching and teaching on the dangers of illegal migration, the provision of vocational training for our teaming youth population to reduce emigration, and the provision of counselling and resettlement programmes for the repatriated and those in refugee camps across the country. The work also encourages the government to evolve modalities to curb the spate of violence and bloodshed that has fuelled refugee crises in Cross River State and Nigeria in general. (shrink)

I offer a new metacognitive account of the feeling of agency over bodily actions. On this model the feeling of agency is the metacognitive monitoring of two cues: i) smoothness of action: done via monitoring the output of the comparison between actual and predicted sensory consequences of action and ii) action outcome: done via monitoring the outcome of action and its success relative to a prior intention. Previous research has shown that the comparator model offers a powerful explanation of (...) the feeling of agency. However, within the literature there is a growing sense of unease with the model; a consensus seems to be building that the model is not up to the task of explaining all of the new discoveries made regarding the feeling of agency since its inception. Most problematically there are paradigms which deeply challenge the comparator model by suggesting that a weak feeling of agency can be elicited even when no motor prediction is formed. The new account offered here inherits the explanatory power of the comparator model whilst avoiding this problem. (shrink)

The viewing patterns of Global Television in Nigeria seem to have undermined the objectives of local media content in the Nigerian media industry. This paper was designed to examine the factors that indicate that global television affect the development of Nigeria’s local content and why most Nigerians prefer to watch global television programmes at the expense of local television programmes even in the wake of assumed improved local contents in the Nigerian media. The study adopted observational and quantitative methods of (...) acquiring data on reasons why most residents in Nigeria prefer to view foreign programmes and how television viewing of global contents from the foreign stations has affected the development of local media content. The questionnaire was the instrument adopted for eliciting data from primary sources who are television viewers in Nigeria. This study proposed and distributed 300 but recovered 267 copies of the ‘Global Television versus Local Television Viewing’ questionnaire to randomly selected members of the population in Calabar, Cross River State. A review of secondary sources including books and articles on television viewing in Nigeria was carried out. The quantitative data was analysed using simple tables and percentages. Findings revealed that a significant number of Nigerians prefer to watch global television programmes because of their intrinsic interest and creative nature including the educational, informational and entertainment value advantage of the programmes over their local counterparts. The study recommends that the states and federal governments in Nigeria should inject more funds into revitalization of local television stations and should employ more experienced and retrain old television staff in their respective television stations in order to improve on the quality and patronage of local content in the Nigerian media. (shrink)

Scalability, efficiency, and security had been a persistent problem over the years in data mining, several techniques had been proposed and implemented but none had been able to solve the problem of scalability, efficiency and security from cloud computing. In this research, we solve the problem scalability, efficiency and security in data mining over cloud computing by using a restful web services and combination of different technologies and tools, our model was trained by using different machine learning algorithm, (...) and finally using different validation and cross-validation methods to compare and validate our results. We build, train, test and deploy our model by restful API services which can be called through an endpoint, and with very high accuracy and huge success. (shrink)

The ways in which the Aristotelian sciences are related to each other has been discussed in the literature, with some focus on the subalternate sciences. While it is acknowledged that Aristotle, and Plato as well, was concerned as well with how the arts were related to one another, less attention has been paid to Aristotle's views on relationships among the arts. In this paper, I argue that Aristotle's account of the subalternate sciences helps shed light on how Aristotle saw the (...) art of rhetoric relating to dialectic and politics. Initial motivation for comparing rhetoric with the subalternate sciences is Aristotle's use of the language of boundary transgression, germane to the Posterior Analytics, when discussing rhetoric’s boundaries, as well as the language of "over" and "under" found in APo. First, I discuss three passages in Rhetoric Book I and argue that Garver's (1988) account cannot be correct. Second, I look to the subalternate sciences, especially focusing on optics and the distinction between "unqualified" optics and mathematical optics. Third, I discuss rhetoric's dependence on both dialectic and politics. (shrink)

Scalability, efficiency, and security had been a persistent problem over the years in data mining, several techniques had been proposed and implemented but none had been able to solve the problem of scalability, efficiency and security from cloud computing. In this research, we solve the problem scalability, efficiency and security in data mining over cloud computing by using a restful web services and combination of different technologies and tools, our model was trained by using different machine learning algorithm, (...) and finally using different validation and cross-validation methods to compare and validate our results. We build, train, test and deploy our model by restful API services which can be called through an endpoint, and with very high accuracy and huge success. (shrink)

This chapter discusses the controversy over the legacy of Kantian moral philosophy in Dewey’s German Philosophy and Politics. It argues that the polemical reaction to Dewey’s book by Julius Ebbinghaus, reiterated through Axel Honneth and Ebbinghaus’s student Georg Geismann, is based on talking at cross-purposes. While Dewey’s reading of Kant is, indeed, flawed, Ebbinghaus and Geismann misconceive Dewey’s argumentative intent. Nevertheless, the controversy serves to clarify Dewey’s line of argument and to discuss parallels with and differences from the (...) world war genealogy and the Frankfurt School’s theory of immanent critique. Furthermore, the chapter suggests that the role of Hegel’s Emptiness Charge in German Philosophy and Politics should be considered in light of Dewey’s theory of growth. Accordingly, Dewey’s book is not merely a piece of “world war literature”, first, because its line of argument also appears in books by Dewey, which are surely not part of this category, and second, because the Hegelian Emptiness Charge is a variant of what Dewey calls a philosophical fallacy. (shrink)

The idea the New Zealand Māori once counted by elevens has been viewed as a cultural misunderstanding originating with a mid-nineteenth-century dictionary of their language. Yet this “remarkable singularity” had an earlier, Continental origin, the details of which have been lost over a century of transmission in the literature. The affair is traced to a pair of scientific explorers, René-Primevère Lesson and Jules Poret de Blosseville, as reconstructed through their publications on the 1822–1825 circumnavigational voyage of the Coquille, a (...) French corvette. Possible explanations for the affair are briefly examined, including whether it might have been a prank by the Polynesians or a misunderstanding or hoax on the part of the Europeans. Reasons why the idea of counting by elevens remains topical are discussed. First, its very oddity has obscured the counting method actually used—setting aside every tenth item as a tally. This “ephemeral abacus” is examined for its physical and mental efficiencies and its potential to explain aspects of numerical structure and vocabulary (e.g., Mangarevan binary counting; the Hawaiian number word for twenty, iwakalua), matters suggesting material forms have a critical if underappreciated role in realising concepts like exponential value. Second, it provides insight into why it can be difficult to appreciate highly elaborated but unwritten numbers like those found throughout Polynesia. Finally, the affair illuminates the difficulty of categorising number systems that use multiple units as the basis of enumeration, like Polynesian pair-counting; potential solutions are offered. (shrink)

The elderly face very challenging situations due to their mental and physical conditions. Like the other country in the world, Bangladesh Government has enacted laws to protect the elderly rights. However, the law does not seem to represent what the elderly actually needs. Therefore, 385 elderly people, aged between 60 and 90 years were surveyed to understand their expectations from family, society, and government. There were 57.1% men and 42.9% women. Most of the elderly (80%) were educated. Just over (...) half (53.5%) had ordinary mental and physical health, while a quarter (31.4%) had good status. More than half (53%) of the participants required 2000–5000 BDTK (Bangladeshi Taka) equivalent to $20-50 to cover monthly treatment expenditures. The majority (67.3%) felt government Old Age Allowance should be increased to BDT 5,000 ($50). Of 13.8% of individuals experienced harsh discourse from family because of the cost of therapy. However, 16.9% of people choose not to respond to this question. More than half (57.4%) of the respondents’ thought caregivers were insufficient. One-third felt that legislation should be changed to take care of parents (33.5%) and One-third felt that children should take care of more (33.5%). Some (3.6%) thought that children should act as they did in their childhood respectively. Almost half (44.2%) of respondents did not know that the elderly should receive a separate senior citizen card for preferential treatment, yet 51.9% thought this. Some (44.7%) felt the elderly should get priority in any queue and discounts in Bus/Uber/Rickshaw. Results also showed that expectation is more than the service provided. Further, a one-stop elderly care clinic is required to provide integrated care and support for the quality of life of the elderly. (shrink)

In this review essay, K. Peter Kuchinke uses three recent publications to consider the question of how to educate young people for work and career. Historically, this question has been central to vocational education, and it is receiving renewed attention in the context of concerns over the ability of schools to provide adequate preparation for occupational roles and career success in a rapidly changing economic landscape. Philip Gonon's Quest for Modern Vocational Education provides a historical account of Georg Kerschensteiner's (...) vision of the role of work as a central subject matter for all students. His approach served as the foundation for the dual system in present‐day Germany. Nancy Hoffman's Schooling in the Workplace contrasts the U.S. system of career preparation for non‐college‐bound students with that of five other OECD nations where workforce and academic preparation are more strongly connected to learning in the workplace. Christopher Winch's Dimensions of Expertise, finally, offers a conceptual analysis of central ideas of vocational knowledge and underscores the important role of learning in the context of practice. The three texts offer historical, comparative, and philosophical analyses of the complex task of preparation for work and challenge education scholars to move the subject matter into the center of contemporary educational theory. (shrink)

This study investigates the dynamics of brick-and-mortar versus click-and-mortar microbusinesses, focusing on the strengths, weaknesses, opportunities, and threats (SWOT) within the local context of Balayan. Ten purposively sampled microbusiness entrepreneurs were examined using the SWOT method. The findings underscore the significance of product assessment, communication, and customer experiences in cultivating trust. Sensory experiences and competitive pricing emerge as strengths, while challenges such as poor sales necessitate strategic interventions. External factors, particularly technological advancements, exert influence on the retail landscape. Key strategies (...) include competitive pricing, flexibility, and an understanding of customer behavior. The study highlights growth potential in tailored experiences but acknowledges the risks posed by e-commerce competition. Additionally, a SWOT strategic plan is developed to leverage internal and external strengths and opportunities while mitigating weaknesses and threats. (shrink)

In this interesting book Aronson discusses lapsed vegetarians, which she dubs lapsos. She argues that lapsos struggle with the implications of eating meat, and in so doing their spirits are strengthened. She offers the book not as a polemic, but rather a peace offering to soften the debate over meat eating, trace ambiguity and nuance, and suggest that being a vegetarian should not be so easy.

The Cartesian concept of nature, which has determined modern thinking until the present time, has become obsolete. It shall be shown that Hegel's objective-idealistic conception of nature discloses, in comparison to that of Descartes, new perspectives for the comprehension of nature and that this, in turn, results in possibilities of actualizing Hegel's philosophy of nature. If the argumentation concerning philosophy of nature is intended to catch up with the concrete Being-of-nature and to meet it in its concretion, then this is (...) impossible for the finite spirit in a strictly a priori sense – this is the thesis supported here which is not at all close to Hegel. As the argumentation rather has to consider the conditions of realization concerning the Being-of-nature, too, it is compelled to take up empirical elements – concerning the organism, for instance, system-theoretical aspects, physical and chemical features of the nervous system, etc. With that, on the one hand, empirical-scientific premises are assumed (e.g. the lawlikeness of nature), which on the other hand become (now close to Hegel) possibly able to be founded in the frame of a Hegelian-idealistic conception. In this sense, a double strategy of empirical-scientific concretization and objective-idealistic foundation is followed up, which represents the methodical basic principle of the developed considerations. In the course of the undertaking, the main aspects of the whole Hegelian design concerning the philosophy of nature are considered – space and time, mass and motion, force and law of nature, the organism, the pro-blem of evolution, psychic being – as well as Hegel's basic thesis concerning the philosophy of nature, that therein a tendency toward coherence and idealization manifests itself in the sense of a (categorically) gradually rising succession of nature: from the separateness of space to the ideality of sensation. In the sense of the double strategy of concretization and foundation it is shown that on the one hand possibilities of philosophical penetration concerning actual empirical-scientific results are opened, and on the other hand – in turn – a re-interpretation of Hegel's theorem on the basis of physical, evolution-theoretical and system-theoretical argumentation also becomes possible. In this mutual crossing-over and elucidation of empirical and Hegelian argumentation not only do perspectives of a new comprehension of nature become visible, but also, at the same time – as an essential consequence of this methodical principle – thoughts on the possibilities of actualizing Hegel's philosophy of nature. (shrink)

I respond to a list of hypotheses explaining why female undergraduates leave philosophy by drawing attention to the period at which we are at and how it affects the task of explanation. I actually focus on ethnic minority underrepresentation, but what I say crosses over: undergraduates one is hoping to attract might well think, “There has to be some problem if these are the proportions at this stage.”.

GAMETOGÊNESE -/- Emanuel Isaque Cordeiro da Silva Instituto Agronômico de Pernambuco Departamento de Zootecnia – UFRPE Embrapa Semiárido -/- • _____OBJETIVO -/- Os estudantes bem informados, estão a buscando conhecimento a todo momento. O estudante de Veterinária e Zootecnia, sabe que a Reprodução é uma área de primordial importância para sua carreira. Logo, o conhecimento da mesma torna-se indispensável. No primeiro trabalho da série fisiologia reprodutiva dos animais domésticos, foi abordado de forma clara, didática e objetiva os mecanismos de diferenciação (...) sexual dos embriões em desenvolvimento, quais os genes envolvidos nesse processo e tudo mais. Nesse segundo trabalho, a abordagem será teórica, mas também clara, sobre a formação primordial dos gametas femininos e masculinos, através da ovogênese nas fêmeas e a espermatogênese nos machos. Esse trabalho visa levar a importância do processo de formação dos gametas e a produção hormonal das gônadas, bem como o entendimento sobre as interações com o eixo hipotálamo-hipofisário. -/- •____INTRODUÇÃO -/- A reprodução sexual é um processo mediante a qual dois organismos da mesma espécie unem seu material genético para dar lugar a um organismo fixo com combinação única de genes; para isso, cada organismo produz células que contém a metade do material genético característico da espécie. Essas células haploides (1n) são denominadas gametas; ao combinar-se um gameta masculino com um feminino produz-se uma célula diploide (2n) (zigoto ou ovo) a partir da qual se forma o embrião. A grande maioria das espécies com reprodução sexual são anisogâmicas, o que significa que produzem dois tipos de gametas diferentes: os gametas masculinos são microscópios, móveis e produzem-se em grande quantidade, enquanto que os femininos são grandes, imóveis e produzem-se em menor quantidade. O tipo de gameta que um indivíduo produz é o que define seu sexo; sobre os animais o macho é o indivíduo que produz grandes quantidades de espermatozoides e a fêmea produz uma menor quantidade de óvulos, enquanto que nas plantas as gônadas masculinas são as produtoras pólen e as femininas produzem oosferas. Os gametas são diferentes do resto das células do organismo, as quais se chamam células somáticas; essas últimas são diploides porque contém dois pares de cromossomos, um par herdado do pai do indivíduo e o outro da mãe. As células somáticas, ademais, se dividem por mitose, ao qual os cromossomos se duplicam antes de cada divisão celular e cada uma das células filhas recebe um complemento diploide idêntico dos cromossomos, logo todas as células somáticas de um indivíduo possuem o mesmo material genético, embora cada tipo celular expresse diferentes combinações de genes. Em contraponto, os gametas são células haploides porque possuem somente um par de cromossomos e a metade do material genético característico da espécie. Cada um dos cromossomos em um gameta é resultado da recombinação dos genes contidos nos cromossomos paterno e materno do indivíduo que originam o gameta, e cada um destes possuem uma combinação única de genes. Os gametas se formam a partir das células germinais, que são células que em sua origem são diploides e elas de “comprometem” a manter-se como uma linha celular especial que em determinado momento sofrerá o processo de meiose para dar origem aos gametas haploides, sejam óvulos ou espermatozoides segundo o sexo do animal. Como descrito no trabalho sobre a diferenciação sexual, as células germinativas primordiais originam-se no epiblasto do embrião, e migram desde o saco vitelino até colonizar as cristas gonodais, onde, por sua vez, proliferam-se e se organizam junto com as células somáticas da gônada primitiva para formar o testículo ou o ovário. As células germinais masculinas e femininas tem a mesma origem embrionária. As gônadas indiferenciadas em um embrião possuem três tipos celulares: as células que dão origem aos gametas (ovogonia ou espermatogonia), as precursoras de células que nutrem os gametas em desenvolvimento (células da granulosa no ovário; células de Sertoli no testículo) e as precursoras de células que secretam hormônios sexuais (células da teca no ovário; células de Leydig no testículo). As células germinais são as únicas estruturas do organismo que têm a capacidade de dividir-se por meiose sofrendo uma redução no número de seus cromossomos, sendo responsável pela transmissão da carga genética aos descendentes. Em contraste, as células somáticas somente se dividem por mitose. A formação dos gametas compreende fases sequenciais de mitose, meiose e pós-meiose. Esses processos são altamente organizados e necessitam de um preciso e bem coordenado programa de expressão genética. Uma das características importantes da gametogênese é a redução cromossômica, que através da meiose, reduz pela metade o número de cromossomos e produz células distintas entre si, devido a trocas de material genético entre os pares de cromossomos provenientes do pai e da mãe, o que ocorre no processo de “crossing over” durante a primeira fase da meiose. A gametogênese é o processo mediante o qual as células germinais de cada sexo se multiplicam, dividem e diferenciam até formar os gametas. No caso da formação dos gametas masculinos o processo recebe o nome específico de espermatogênese, e para os gametas femininos é denominado como ovogênese. Embora os dois processos alcancem o objetivo comum de produção das células haploides, por onde compartilham algumas características, existem diferenças marcadas entre eles devido a necessidade de produzir um número muito distinto de gametas, de tamanho diferente, e com características de motilidade também distintas. -/- •___ESPERMATOGÊNESE -/- A espermatogênese é o processo mediante o qual se produz os gametas masculinos denominados espermatozoides. Durante a vida fetal as células germinais e as células somáticas do testículo em formação organizam-se em túbulos seminíferos que se derivam dos cordões sexuais primários e conformam a maior parte da medula do testículo. Na etapa fetal cada tubo seminífero é delimitado por uma membrana basal, recoberta na parte interior pelas células precursoras das células de Sertoli (um tipo de células somáticas). No exterior do túbulo localizam-se as células precursoras das células de Leydig ou intersticiais (figura 1), que também são células somáticas. Entre a membrana basal e as células de Sertoli encontram-se algumas células germinais denominadas espermatogonias de reserva A0 (denominadas gonócitos) que serão o único tipo de células germinais presentes no testículo enquanto o animal não alcançar a puberdade. As células de Sertoli estabelecem na região basal uniões oclusoras entre si, formando parte da barreira hemato-testicular. As espermatogonias A0 localizam-se por dentro da membrana basal do túbulo seminífero, embora fora da barreira hemato-testicular. Figura 1: fase neonatal. Nota-se a grande infiltração de tecido intersticial em quase 50% da seção originando que os túbulos sejam pequenos e redondos em sua maioria. O citoplasma e núcleo das células pré-Leydig são notadas claramente por essa ser uma espécie suína onde o tecido intersticial está claramente diferenciado. Hematoxilina-eosina (X 220.5). Fonte: Embrapa. -/- O número de células de Sertoli no testículo depende da influência do hormônio folículo estimulante (FSH) presente durante a vida fetal e as primeiras etapas de vida pós-natal. A população de células de Sertoli ao chegar a puberdade se manterá fixa durante o resto da vida do animal; existe uma relação positiva entre o tamanho e a população de células de Sertoli e a capacidade de produção de espermatozoides do testículo. As células de Sertoli são as únicas células somáticas que estão no epitélio seminífero, e sua função é a nutrição, sustentação e controle endócrino das células germinais. As células de Sertoli participam ativamente no processo de liberação dos espermatozoides para a luz do túbulo. Nesse momento, as células de Sertoli realizam a fagocitose de parte do citoplasma do espermatozoide dos chamados corpos residuais. As células de Sertoli também fagocitam as células germinais que se degeneram no curso normal da espermatogênese. Essas células ainda sintetizam grande quantidade de proteínas, como por exemplo as proteínas ABP (androgen hinding protein), que transportam andrógenos para todo o aparelho reprodutivo, transferrinas, que transportam ferro para a respiração celular das células germinais e também às inibinas, que regulam a liberação de FSH pela hipófise, através de um sistema de retroalimentação (feedback) negativa (figura 2). Figura 2: epitélio seminífero, células de Sertoli (flecha) (400 X). Fonte: Embrapa. -/- Antes da puberdade dos túbulos seminíferos observam-se ao corte como estruturas de diâmetro pequeno, sem luz, e conformados unicamente pelas células de Sertoli e espermatogonias de reserva e rodeados por abundante tecido intersticial, ao que estão presentes as células precursoras das células de Leydig. Ainda antes da puberdade, a diferenciação celular manifesta-se primeiro pela presença de espermatócitos primários, os quais se degeneram em geral na fase de paquíteno, por falta de estimulação hormonal. A partir de que o animal chega a puberdade inicia-se o processo de espermatogênese, que se manterá durante toda a vida do animal, exceto em espécies de animais silvestres muito estacionais, ao qual pode se suspender durante a época não reprodutiva para voltar e ser retomada na época ou estação reprodutiva. Depois da puberdade, os túbulos seminíferos possuem um diâmetro muito maior; em seu interior observa-se um grande número de células germinais de todos os tipos, diferentes estádios de divisão, e em seu lúmen contém líquido e espermatozoides. Ainda sobre o alcancei da puberdade, as espermatogonias começam a dividir-se aceleradamente por mitose, enquanto que no espaço intersticial as células mesenquimais também começam a se diferenciar e a dar origem as células de Leydig (figura 3). A partir dessa etapa as células de Leydig (totalmente diferenciadas) são também evidentes no exterior do túbulo, junto com as células mioides ou peritubulares que o rodeiam o que ao contrair-se são responsáveis por controlar o avanço dos fluidos e as células presentes no lúmen do túbulo. As células mioides estão situadas ao redor do túbulo, e é creditado a elas a promoção da contração e da integridade estrutural do túbulo. Esse tipo celular apenas se diferencia na puberdade pela ação dos andrógenos (figura 4). As interações entre as células de Sertoli e as mioides parecem ter um papel importante na manutenção das funções do testículo. Durante o processo de espermatogênese, as espermatogonias de reserva dividem-se periodicamente e enquanto algumas células fixas permanecem como espermatogonias de reserva, outras proliferam e sofrem uma seção de divisões mitóticas durante as quais se vão diferenciando até formarem espermatócitos primários (espermatocitogênese ou fase de mitose), logo sofrem divisões especiais mediante as quais reduzem seu número de cromossomos (fase de meiose), e ao final trocam de forma para converter-se em espermatozoides (espermatocitogênese) (figura 5). Cada uma dessas etapas da espermato- gênese será descrito detalhadamente adiante, antes é necessário a explicação de algumas características das células de Sertoli e de Leydig que ajudarão a entender seu papel durante a espermatogênese. Figura 3: células de Leydig no espaço intersticial do testículo bovino adulto PAS (400 X). Fonte: Embrapa. -/- Figura 4: o estabelecimento da puberdade pela presença de espermatozoides no túbulo. Hematoxilina-eosina (400 X). Fonte: Embrapa. Figura 5: fases mitóticas das espermatogonias (A0 e B) para formação de um espermatócito primário e as duas fases de meiose que se sucedem antes da espermatogênese. Fonte: ZARCO, 2018. -/- Ao início da espermatocitogênese as uniões oclusoras entre as células de Sertoli se abrem por etapas (como as comportas de um submarino) para permitir a passagem das espermatogonias em direção ao centro do túbulo seminífero sem que se estabeleça uma continuidade entre o exterior e o interior da barreira hemato-testicular. Uma vez ultrapassada essa barreira, as sucessivas gerações de espermatogonias, espermatócitos, espermátides e espermatozoides irão se localizar em direção ao interior do túbulo seminífero, em estreita associação com as células de Sertoli. Em consequência, as células de Sertoli dividem o túbulo seminífero em dois compartimentos; o compartimento basal (debaixo das uniões oclusoras das células de Sertoli), ao qual residem as espermatogonias de reserva, e o compartimento adluminal (em direção ao centro do túbulo), cujos espaços entre as células de Sertoli desenvolvem o resto do processo de espermatogênese (meiose e espermatocitogênese). Esse feito é importante porque durante a vida fetal as únicas células germinais existentes eram as espermatogonias de reserva, pelo que os antígenos expressados por gerações mais avançadas (espermatogonias intermediárias, secundárias, espermátides e espermatozoides) não são reconhecidos como próprios do corpo pelo sistema imunológico. Logo, o anterior implica que deve existir uma barreira entre eles e o sangue para evitar um ataque imunológico. Em todas as etapas da espermatogênese, as células de Sertoli atuam como células de suporte para as células germinais, que sempre permanecem recoberta pela membrana das células de Sertoli. Também atuam como células nutricionais já que proporcionam o meio em que as células germinais se desenvolvem e maturam, assim como as substâncias que regulam e sincronizam as sucessivas divisões e transformações das células germinais. As células de Sertoli produzem hormônios, como estrógenos e inibina que atuam sobre a hipófise para regular a secreção das gonadotropinas que controlam a espermatogênese. As células de Leydig que residem no exterior do túbulo seminífero também são importantes para a espermatogênese: produzem a testosterona que estimula e mantém a espermatogênese, bem como serve como substrato sobre o qual atua como aromatizador das células de Sertoli para transformá-las em estrógenos. Como supracitado, para seu estudo podemos dividir a espermatogênese em três fase: espermatocitogênese, meiose e espermiogênese (figura 6). Agora, serão descritas cada uma dessas etapas. Em algumas espécies, incluindo no homem, os macrófagos representam o segundo tipo celular intersticial mais numeroso no testículo, depois das células de Leydig. Os macrófagos e vários subtipos de linfócitos são identificados nós testículos de ovinos e ratos. Eles estão intimamente associados com as células de Leydig e atuam juntamente na regulação da esteroidogênese. Figura 6: fluxograma da espermatogênese. -/- Espermatocitogênese -/- A espermatocitogênese, também chamada de etapa proliferativa ou de mitose, consiste numa série de divisões mitóticas sofridas pelas células descendentes de uma espermatogonia de reserva. Uma vez que a célula se divide, abandona o estado de reserva e começa um processo de diferenciação. As espermatogonias de reserva (denominadas espermatogonias A0 na rata ou As nos humanos) são células que existem desde a vida fetal e que permanecem mitoticamente inativas durante a infância. Uma vez que alcançam a puberdade começam a dividir-se em intervalos regulares, e as células filhas podem permanecer como espermatogonias de reserva ou abandonar a reserva e ingressar na dita espermatocitogênese. Uma vez abandonada a reserva, as células filhas que vão se formando em cada divisão permanecem unidas por pontes citoplasmáticas, constituindo um clone que se divide sincronicamente. As células que se formam depois de cada divisão continuam sendo espermatogonias, porém cada geração é ligeiramente diferente da anterior. Na rata, por exemplo, as espermatogonias tipo A0 ao dividir-se originam espermatogonias do tipo A1, que em sucessivas divisões formam espermatogonias dos tipos A2, A3 e A4, as quais, por sua vez, sofrem outra mitose para formar espermatogonias intermediárias e uma mais para formar espermatogonias do tipo B. Essas últimas se diferenciam (sem se dividir) em espermatócitos primários, processo em que termina a fase de espermatocitogênese, que literalmente significa processo de geração de espermatócitos. As espermatogonias tipo A0 são a fonte para a contínua produção de gametas. A metade delas se dividem e formam células iguais (as chamadas células tronco) e a outra metade forma as espermatogonias A1, que sofre novas divisões mitóticas e formam os tipos 2, 3 e 4. O tipo A4 sofre mitose para formar a intermediária (A In), que por mitose, forma a tipo B (figura 6). Esses tipos de espermatogonias podem ser identificadas em evoluções histológicas de acordo com sua organização topográfica na membrana basal dos túbulos seminíferos ou mediante seu conteúdo de heterocromatina. Outra maneira de diferenciação se baseia em marcadores moleculares específicos que distinguem as espermatogonias tronco (A0) das demais, com os fins de isolamento, desenvolvimento in vitro e transplante. As tipo B passam por mitose para formarem os espermatócitos primários; estes iniciam a primeira etapa da meiose formando os espermatócitos secundários; na segunda etapa da divisão meiótica, cada espermatócito secundário se divide e formam as chamadas espermátides. Quando o testículo alcança seu desenvolvimento total, a meiose completa-se e as espermátides originadas se convertem em espermatozoides. Um dos maiores sinais característicos desse fenômeno é o alargamento das espermátides e sua migração em direção ao lúmen do túbulo seminífero (figuras 4, 7 e 8). Figura 7: espermatogonias marcadas por imuno-histoquímica, anticorpo monoclonal TGFa (400 x). Figura 8: fases de divisões meióticas (M), espermatócitos em paquíteno (PA) e espermatócitos secundários (ES). -/- Figura 9: estádio posterior a liberação dos espermatozoides na luz do túbulo. Hematoxilina-eosina (400 x). Mediante as seis divisões mitóticas que ocorrem durante a espermatocitogênese se forma potencialmente um clone de 64 espermatócitos primários a partir de cada espermatogonia A que ingressa sobre o processo. Não obstante, algumas células sofrem apoptose em cada uma das etapas do processo, ao qual o número real formado é menor. Em outras espécies produzem-se um transcurso similar de divisões mitóticas sucessivas durante a espermatocitogênese, embora a nomenclatura utilizada possa ser distinta, por exemplo nos bovinos as duas últimas divisões mitóticas dão origem as espermatogonias de tipo B1 e B2. -/- Meiose -/- Uma vez que as espermatogonias B se diferenciam em espermatócitos primários, esses iniciam a etapa de meiose, com uma nova divisão; desta vez a divisão é do tipo meiótica. Ao completar-se a primeira divisão meiótica (meiose I) se obtém os espermató-citos secundários, que ao sofrer a segunda divisão meiótica (meiose II) dão origem as espermátides. Vale salientar que a meiose é o processo mediante o qual reduz-se a metade do número de cromossomos, pelo que as espermátides que se obtém são células haploides (1n). Os espermatócitos secundários que se formam depois da primeira divisão meiótica contém a metade do número normal de cromossomos, porém a mesma quantidade de DNA já que cada cromossomo é duplo. As espermátides formadas na conclusão da segunda divisão meiótica (figura 7), por sua vez, contém a metade dos cromossomos, e esse já não são duplos, já que se trata de células 1n. Também deve-se enfatizar que durante a meiose é relevante o entrecruzamento dos cromossomos homólogos, pelo que cada espermátide possui uma combinação única e diferente de genes paternos e maternos. Outro ponto que deve ser levado em consideração é que cada espermátide somente possui um cromossomo sexual; a metade das espermátides contém o cromossomo X herdado da mãe do macho que está levando a cabo a espermatogênese e a outra metade contém o cromossomo Y herdado de seu pai. Para cada espermatócito primário que entra no processo de meiose obtém-se cerca de quatro espermátides, pelo qual ao ser completada a meiose potencialmente se poderiam formar até 256 espermátides por cada espermatogonia que abandona a reserva e ingressa na espermatocitogênese. -/- Espermiogênese -/- Durante a espermiogênese, também chamada de fase de diferenciação, as esper-mátides sofrem, sem se dividir, uma metamorfose que as transforma em espermatozoides, os quais finalmente são liberados das células de Sertoli em direção ao lúmen do túbulo seminífero. A espermiogênese é um processo complicado e longo já que a espermátide deve sofrer complexas trocas nucleares, citoplasmáticas e morfológicas que resultam na forma-ção dos espermatozoides. Algumas dessas mudanças incluem a condensação do material nuclear para formação de um núcleo plano e denso, a eliminação do citoplasma para a constituição de uma célula pequena, a formação de uma estrutura especializada denomi-nada acrossomo ou tampa cefálica, e a formação do pescoço e da cauda (flagelo) do esper-matozoide, do que depende a sua motilidade. Durante a maior parte da espermiogênese, as espermátides se mantém com uma estreita associação com as células de Sertoli; logo, chega-se a observar, então, flagelos que se projetam em direção a luz do túbulo que pare-cem sair das células de Sertoli, sendo na realidade os flagelos dos espermatozoides que ainda não tinham sido liberados pelo lúmen. Ao liberar os espermatozoides em direção a luz do túbulo, as células de Sertoli realizam a fagocitose de parte do citoplasma dos espermatozoides (corpos residuais). Também fagocitam os restos de todas as células germinais que sofrem apoptose ou degeneram-se durante a espermatogênese. Credita-se que ao realizar essas funções as células de Sertoli podem fazer uma monitoração eficiente da espermatogênese, o que lhes permitiria emitir sinais para colaborar na regulação desse processo em nível gonodal e a nível sistêmico através da secreção de hormônios como a inibina e o estradiol. Além da inibina e activina, as células de Sertoli sintetizam outras proteínas, como a ABP (proteína ligadora de andrógenos) que serve como uma molécula de transporte de andrógenos dentro dos túbulos seminíferos, ductos deferentes e epidídimo, ou a transfer-rina, que transporta o ferro necessário para a respiração celular. -/- Resultados da espermatogênese -/- O resultado da espermatogênese não significa apenas uma simples multiplicação das células germinais (até 256 espermatozoides a partir de cada espermatogonia A1), senão que através dela são produzidos gametas haploides pequenos, móveis e com grande diversidade genética entre eles, ao mesmo tempo que se mantêm uma reversa de células mãe (espermatogonias A0) a partir das quais se poderiam originar novos ciclos de esper-matogênese durante o resto da vida do animal. -/- Controle hormonal da espermatogênese -/- Como mencionado, o FSH reproduz um importante papel para o estabelecimento das células de Sertoli durante a vida fetal e início da vida pós-natal. O começo da esper-matogênese também é estimulado pelo FSH, que atua sobre as células de Sertoli para estimular sua função e a ativação de sinais dessas células em direção as células germinais, incluindo-as a abandonar a reserva e ingressar na espermatogênese. O FSH, assim mesmo, estimula a mitose durante o resto da espermatogênese e aumenta a eficiência do processo, já que reduz a apoptose e a degeneração de espermatogonias intermediárias e do tipo B. O FSH também estimula as células de Sertoli para produzirem inibina e ABP. Uma vez iniciada a espermatogênese somente requerem níveis baixos de FSH para se mantê-la. As células de Sertoli também devem ser estimuladas pela testosterona para funcio-nar de maneira adequada; se requer também do LH hipofisário: hormônio que estimula as células de Leydig para produzir testosterona. Por sua vez, a secreção de LH e FSH é regulada pelo GnRH hipotalâmico: esse neurohormônio também faz parte do mecanismo de regulação da espermatogênese. A espermatogênese também é modulada em nível local mediante a produção de determinados fatores e interações entre as células. Dentro dos fatores locais podemos mencionar o fator de crescimento parecido com a insulina 1 (IGF-1), o fator de crescimen-to transformante beta (TGF- β), activina, ocitocina e diversas citocinas. Entre as intera-ções celulares existem tanto uniões de comunicação entre as células de Sertoli e as células germinais, como pontes citoplasmáticas entre todas as células germinais que formam o clone de células descendentes de uma espermatogonia A1. Uma vez que as células de Sertoli iniciam sua função na puberdade é possível manter experimentalmente a espermatogênese somente com testosterona, sem ser requeri-dos nenhum outro hormônio. A quantidade de espermatozoides produzidos, no entanto, é maior quando há presença do FSH. Abaixo do estímulo do FSH as células de Sertoli produzem estradiol e inibina, hormônios que geram uma retroalimentação sobre o eixo hipotálamo-hipofisário para a regulação da secreção de gonadotropinas. Em particular, a inibina reduz a secreção de FSH, pelo qual é factível que sirva como um sinal que evite uma excessiva estimulação as células de Sertoli. -/- Ciclo do epitélio seminífero -/- Em cada espécie as espermatogonias de reserva iniciam um novo processo de divi-sões celulares em intervalos fixos: a casa 14 dias no touro; 12 dias no garanhão e a cada 9 dias no cachaço (reprodutor suíno). A nova geração de células que começam a proliferar sobre a base do tubo deslocam-se em direção ao centro do túbulo a geração anterior, que por sua vez deslocam-se as gerações anteriores. Devido as mudanças que vão sofrendo cada geração celular se ajustam a tempos característicos de cada etapa, já que rodas as células em uma determinada seção do túbulo estão sincronizadas entre si pelas células de Sertoli; em cada espécie somente é possível encontrar um certo número de combinações celulares: 14 diferentes combinações no caso da rata, 8 no touro e 6 no ser humano. A sucessão de possíveis combinações até regressar a primeira combinação se conhece como o ciclo do epitélio seminífero. Na maioria das espécies os espermatozoides que são libera-dos em direção a luz do túbulo provém das células que entraram no processo de esperma-togênese quatro gerações antes que a geração que está ingressando nesse momento, pelo que a espermatogênese no touro dura ao redor de 60 dias e um pouco menos em outras espécies domésticas. Significa que os efeitos negativos das alterações na espermatogêne-se podem estar presentes até dois meses depois de que se produziram essas alterações. Como supracitado, geralmente se observa a mesma combinação celular em toda a área de uma determinada secção transversal do túbulo seminífero. No entanto, se fizermos uma série de secções, observa-se que ao longo do túbulo há uma sucessão ordenada de combinações (a primeira em uma determinada secção; a segunda combinação na seguinte secção, e assim sucessivamente em secções subsequentes até regressar a primeira combi-nação. Teremos, então, que ao início da divisão das espermatogonias A1 se produz de forma sincronizada em uma secção do túbulo, e vai-se transmitindo como uma onda peristáltica as secções adjacentes. Esse processo é denominado como onda do epitélio seminífero e graças à esse túbulo seminífero sempre tem secções em todas as etapas da espermatogênese, com o que se alcança uma produção constante de espermatozoides. -/- Alterações da espermatogênese -/- Nas espécies estacionais a espermatogênese, como já mencionado, pode reduzir-se ou inclusive suspender sua atividade fisiológica durante a época não reprodutiva dessas espécimes, porém esse processo fisiológico não pode ser considerado como uma altera-ção. No entanto, a espermatogênese só pode ser alterada pelas enfermidades ou por fatores externos. A principal causa de alterações na espermatogênese é o aumento da temperatura testicular. Por isso, os testículos são localizados na saco escrotal e são “caídos” para fora do corpo como pode-se observar nos bovinos, caprinos, ovinos, caninos e no próprio homem. A temperatura testicular deve estar cerca de 2 a 6 °C abaixo da temperatura corporal normal. As células germinais masculinas são sensíveis ao calor, pelo qual na maioria dos mamíferos os testículos se encontram fora da cavidade abdominal e existe um sofisticado sistema de termorregulação para mantê-los a uma temperatura menor que a corporal. Se a temperatura corporal for elevada ou se os testículos permanecerem na cavidade abdominal, ou ainda se os sistemas termorreguladores do testículo sejam afetados por fatores inflamatórios como edema ou falta de mobilidade testicular dentro do escroto, a temperatura do tecido testicular aumentará e a espermatogênese sofrerá alterações proporcionais ao excesso de temperatura e a duração da elevação. A espermatogênese também pode ser afetada pela exposição a hormônios ou a outras substâncias. É possível que a causa mais comum (sobretudo no homem) seja o uso de esteroides anabólicos, que elevam a concentração de andrógenos na circulação, provo-cando um feedback negativo sobre a secreção de gonadotropinas. Ao deixar de estimular-se o testículo pelas gonadotropinas, este deixará de produzir testosterona, e as concentra-ções de andrógeno exógeno nunca alcançará as altíssimas concentrações de testosterona que normalmente estão presentes a nível do tecido testicular por ser o local onde se produz o hormônio. Também se supõe que diversas substâncias com propriedades estrogênicas derivadas de processos industriais (indústria dos plásticos, hidrocarbonetos etc.) e presentes no ambiente (fatores xenobióticos) podem ser responsáveis pelas alterações na espermatogênese em diversas espécies, entre as quais se inclui o ser humano. -/- • OVOGÊNESE E FOLICULOGÊNESE -/- A ovogênese é o processo seguido pelas células germinais da fêmea para a forma-ção dos óvulos, que são células haploides. Durante a vida fetal as células germinais proliferam-se no ovário por mitose, formando um grande número de ovogonias, algumas das quais se diferenciam em ovócitos primários que iniciam sua primeira divisão meiótica para deter-se na prófase da divisão. Somente alguns desses ovócitos primários retornarão e concluirão a primeira divisão meiótica em algum momento da vida adulta do animal, dando origem a um ovócito secundário e a um corpo polar. O ovócito secundário inicia a sua segunda divisão meiótica, a qual volta a ficar suspensa até receber um estímulo apropriado, já que somente os ovócitos secundários que são ovulados e penetrados por um espermatozoide retornam e concluem a segunda divisão meiótica, dando origem a um óvulo (figura 10). O processo de ovogênese é realizado dentro dos folículos ovarianos, que também tem que sofrer um longo transcurso de desenvolvimento e diferenciação denominado foliculogênese pelo que a ovogênese como tal realiza-se dentro do marco desse último processo. Por essa razão, na seguinte seção descreverei tanto a ovogênese como a folicu-logênese, e a relação que existe entre ambos. Figura 10: representação da ovogênese. Na etapa de proliferação, as células germinais se diferen-ciam por mitose. A meiose I se caracteriza por uma prófase prolongada, ocorrendo a duplicação do DNA. Nas duas divisões, que ocorrem antes da ovulação e depois da fertilização, a quantidade de DNA é reduzida a 1n, com o fim de que a fusão dos pronúcles (singamia) pós-fertilização, seja gerado um zigoto com um número de cromossomos de 2n (diploide). -/- Geração de ovócitos primários e folículos primordiais Tanto a ovogênese como a foliculogênese iniciam-se durante a vida fetal, quando as células germinais primordiais provenientes do saco vitelino colonizam a gônada primitiva e, junto com as células somáticas z organizam-se para a formação dos cordões sexuais secundários, que se desenvolvem principalmente no córtex do ovário. Nesse período, as células germinais que colonizaram o ovário sofrem até 30 divisões mitóticas, proliferando-se até formar milhares ou milhões de ovogonias, que inicialmente formam “ninhos” constituídos cada um deles por um clone de várias ovogonias que descendem da mesma célula precursora e que se mantêm unidas por pontes citoplasmáticas, sincronizan-do suas divisões mitóticas. Nessa etapa alcança-se a máxima população de células germinais no ovário, que antes de nascer se reduzirá drasticamente por apoptose. No ovário do feto humano chegam a haver até sete milhões de células germinais que ao nascimento se reduzem a dois milhões. Os ovários fetais do bovino, de maneira análoga, chegam a ter até 2.100.000 células germinais, que ao nascimento reduzem para 130.000 aproximadamente. A redução no número de ovogonias produz-se ao mesmo tempo que essas células, que vêm dividindo-se por mitose e estão agrupadas em ninhos, iniciam sua primeira divisão meiótica para se transformarem em ovócitos primários: células germinais que se encontram em uma etapa de suspensão (diplóteno) da prófase da primeira divisão meiótica. Nesse período produz-se uma grande proporção de células germinais; as células somáticas dos cordões sexuais, por sua vez, emitem projeções citoplasmáticas que separam a isolam os ovócitos primários sobreviventes, ficando cada um deles rodeados por uma capa de células aplanadas da (pré) granulosa. Ao mesmo tempo em que se forma uma membrana basal entre as células da granulosa e o tecido intersticial do ovário. Ao ovócito primário rodeado de uma capa de células da (pré) granulosa aplanadas e delimita-das por uma membrana basal denomina-se de folículo primordial (figura 11). Nas vacas os folículos primordiais bem formados já estão presentes nos ovários a partir do dia 90 da gestação. A maioria dos folículos primordiais com os que nasce uma fêmea se manterão inativos durante um longo tempo; muitos deles durante toda a vida do animal. Nos folículos primordiais inativos tanto os ovócitos primários como as células da granulosa conservam sua forma original e mantém um metabolismo reduzido estritamente ao mínimo necessário para manter-se viáveis. Por essa razão, ao realizar um corte histológico de qualquer ovário as estruturas mais numerosas que se observam serão os folículos primordiais. No entanto, cada dia da vida de um animal, inclusive desde a vida fetal, um certo número de folículos primordiais reiniciam seu desenvolvimento, e a partir desse momento um folículo exclusivamente pode ter dois destinos: o primeiro, prosseguir seu desenvolvi-mento até chegar a ovular, e o segundo (que é muito mais frequente) encontrar em algum momento condições inadequadas que fazem fronteira com ele para parar seu desenvolvi-mento, levando-o a sofrer atresia e degenerar até desaparecer do ovário. Figura 11: sequência da foliculogênese apresentando as diferentes estruturas que podemos encontrar em cada fase. Fonte: ZARCO, 2018. Culminação da ovogênese A ovogênese somente se completará quando um ovócito primário reinicia a meio-se; completa sua primeira divisão meiótica para formar um ovócito secundário e um primeiro corpo polar e, quando, finalmente sofrer uma segunda divisão meiótica para formar um óvulo e um segundo corpo polar. Os óvulos são as células 1n que constituem os gametas femininos, pouco numerosos, grandes e imóveis. A grande maioria dos ovóci-tos primários, como veremos mais adiante, nunca retomam a meiose e, em consequência, não chegam a formar ovócitos secundários, e muitos dos ovócitos secundários tampouco sofrem uma segunda divisão meiótica, pelo que não chegam a formar os óvulos. Ao longo da vida de uma fêmea, na maioria das espécies, menos de 0,1% dos ovócitos primários (um a cada mil) chega a terminar a ovogênese, dando origem a um óvulo. O supracitado deve-se a que a ovogênese somente pode retomar-se e ser completa-da em ovócitos primários que se encontram dentro dos folículos primordiais que (uma vez ativados) vão alcançando diversas etapas de seu desenvolvimento em momentos precisos aos que encontram as condições ideais de oxigenação, nutrição, vascularização e exposição a fatores parácrinos e a exposição a concentrações de hormônios que se requerem para que o folículo continue em cada etapa de seu desenvolvimento com o processo de foliculogênese até chegar a ovular. Qualquer folículo que não esteja nessas condições ao longo do desenvolvimento sofrerá degeneração e atresia, pelo que o ovócito primário em seu interior nunca chegará ao ponto em que pode retomar a primeira divisão meiótica. No que resta da presente seção revisaremos o processo de foliculogênese em cujo marco se desenvolve a ovogênese; havemos que tomar de conta que essa última se limita ao que ocorre nas células germinais (ovogonia, ovócito primário, secundário e óvulo), pelo qual depende intimamente do desenvolvimento do folículo de que essas células formam parte. Em um princípio a ativação do folículo primordial e o desenvolvimento folicular são independentes das gonadotropinas: não se conhecem os mecanismos precisos median-te os quais um folículo primordial se ativa e reinicia seu desenvolvimento, nem como se decide quais folículos, dentre as dezenas de milhares de ou centenas de milhares presentes em um ovário se reativarão em um dia em particular. A reativação trata-se de uma liberação de influência de fatores inibidores, já que os folículos primordiais se reativam espontaneamente quando cultivados in vitro, isolados do resto do tecido ovariano. Uma vez que um folículo primordial se ativa, inicia-se um longo processo de desenvolvimento que somente depois de vários meses (ao redor de cinco meses no caso dos bovinos) o levará a um estádio em que seu desenvolvimento posterior requer a presença das gonado-tropinas; daí que se diz que as primeiras etapas do desenvolvimento são independentes das gonadotropinas. Durante a fase independente de gonadotropinas, um folículo primordial que tenha sido ativado e tenha começado a crescer; passará primeiro para a etapa de folículo primá-rio, caracterizada por conter um ovócito primário que está rodeado, por sua vez, por uma capa de células da granulosa, que não são planas, e sim cúbicas. Depois, se o folículo continuar crescendo se transformará em um folículo secundário, ao qual as células da granulosa começam a proliferar (aumentando em número) e se organizam em duas ou mais capas que rodeiam o ovócito primário. Entre o ovócito e as células da granulosa que o rodeiam se forma nesta uma zona pelúcida; ainda assim o ovócito mantém contato direto com essas células, mediante o estabelecimento de pontes citoplasmáticas que atravessam a zona pelúcida. Através dessas pontes citoplasmáticas as células da granulosa podem passar nutrientes e informação ao ovócito primário. O volume e o diâmetro do ovócito primário aumentam ao mesmo tempo que as células da granulosa proliferam-se, para incrementar as capas ao redor do ovócito. De maneira gradual o citoplasma do ovócito primário aumenta até 50 vezes seu volume e a proliferação das células continua. Esses folículos que possuem cada vez mais células e portanto mais capas de células da granulosa se denominam folículos secundários. Para evitar confusões, há a necessidade de nomen-clatura ao qual o folículo vá mudando de nome de primordial a primário e logo, de secun-dário, a terciário, por sua vez, o ovócito que encontra-se em seu interior, a todo momento, segue sendo um ovócito primário. Durante a etapa dependente de gonadotropinas, os folículos secundários começam a formar um espaço cheio de líquido, o antro folicular, desse modo se convertem em folí-culos terciários. Com a utilização de outra nomenclatura, a formação do antro marca a transição entre folículos pré-antrais (sem antro) e folículos antrais (com antro). Em algum momento dessa transição entre folículo secundário e terciário, também aparece a depen-dência de folículos em direção as gonadotropinas, pelo qual somente podem seguir crescendo na presença do hormônio luteinizante (LH) e do hormônio folículo estimulante (FSH). Nos bovinos e em outras espécies (para seu estudo), os folículos antrais são dividi-dos em pequenos, médios e grandes. Embora todos eles possuam um antro folicular, dependendo do seu grau de desenvolvimento requerem diferentes concentrações de gona-dotropinas para continuar o crescimento. Os folículos antrais mais pequenos somente re-querem concentrações baixas de LH e FSH, pelo qual podem continuar crescendo em qualquer momento do ciclo estral inclusive em animais que não estão ciclando (fêmeas em anestro pré-puberal, gestacional, lactacional, estacional). Nas etapas posteriores os folículos antrais requerem primeiro concentrações elevadas de FSH, e nas etapas finais somente podem continuar crescendo na presença de pulsos frequentes de LH, pelo qual somente os folículos que encontram-se sob concentrações apropriadas desses hormônios podem seguir crescendo. Por essa razão, nos animais que se encontram em anestro de qualquer tipo somente é possível encontrar folículos antrais pequenos ou médios, segundo a espécie, e nos animais que se encontram ciclando (estro) o maior tamanho folicular encontrado em um determinado dia do ciclo dependerá das concentrações de FSH e LH presentes nesse momento e nos dias anteriores. Um folículo que chega ao estado máximo de desenvolvimento, conhecido como folículo pré-ovulatório, ao final, somente chegará a ovular se for exposto a um pico pré-ovulatório de LH. Como supracitado, cada dia na vida de uma fêmea inicia seu desenvolvimento um certo número de folículos; a grande maioria sofrem atresia, mas depois da puberdade em cada dia do ciclo estral um ou vários folículos vão encontrando ao longo do seu desenvol-vimento concentrações hormonais que lhes permite chegar na etapa de folículo pré-ovula-tório. Somente nestes folículos, e como consequência de um pico pré-ovulatório de LH, se reinicia e completa-se a primeira divisão meiótica do ovócito primário, produzindo duas células distintas. Uma delas é o ovócito secundário, que retém praticamente todo o citoplasma. Contém, assim mesmo, em seu núcleo um par de cromossomos duplos, a outra é o primeiro corpo polar, que é exclusivamente um núcleo com uma quantidade mínima de citoplasma. Na maioria das espécies ovula-se um ovócito secundário que se encontra, então, suspendido na segunda divisão meiótica. Esta segunda divisão meiótica somente reinicia-rá e completarar-se uma vez que o espermatozoide começa a penetrar sob o ovócito secundário. Ao concluir-se a divisão se forma o segundo corpo polar e completa-se a ovogênese com o qual se obtém o óvulo, célula 1n que constitui o gameta feminino. No entanto, o óvulo existe pouco tempo como tal, já que em poucos minutos/horas (depen-dendo da espécie) se produzirá a fusão do núcleo do mesmo (pró-núcleo feminino) com o do espermatozoide (pró-núcleo masculino), com o qual se completa a fertilização e se forma um novo indivíduo (o ovo ou zigoto). -/- Ondas foliculares -/- Como mencionado supra, todos os dias um determinado número de folículos pri-mordiais se ativam e começam a crescer, os quais crescem em um ritmo característico em cada espécie. Isso provoca que em qualquer momento existam nos ovários folículos pri-mordiais (que começam a crescer em alguns dias ou semanas), assim como folículos secundários em diversas etapas do desenvolvimento, os quais iniciaram seu desenvolvi-mento em semanas ou inclusive meses (segundo o grau de desenvolvimento atual). Também em qualquer momento poderá haver folículos antrais nas etapas iniciais de seu desenvolvimento (com antros que já se podem detectar em cortes histológicos mas não são visíveis macroscopicamente). Todos esses folículos chegaram até seu estado de de-senvolvimento atual (primário, secundário ou antral pequeno), independente da etapa do ciclo estral em que sejam observados ou encontrados. Nos bovinos, os folículos que chegam ao início da etapa antral iniciaram seu desenvolvimento cinco meses antes, e todavia requerem ao redor de 42 dias para chegar ao estado pré-ovulatório. Para continuar seu desenvolvimento, os folículos antrais pequenos devem encon-trar concentrações altas de FSH, que os estimulam para prosseguir o crescimento. Cada vez que se produz uma elevação nas concentrações de FSH, esse hormônio estimula o desenvolvimento de um grupo de folículos antrais pequenos, que começaram a crescer muito tempo antes e que o dia da elevação de FSH tenha alcançado o grau de desenvolvi-mento preciso para responder com eficiência a este hormônio, o qual atuará através de seus receptores nas células da granulosa para estimular a produção de estradiol, a secreção de inibina, a produção de líquido folicular e a proliferação das células da granulosa. Um grupo de folículos antrais pequenos é assim recrutado pelo FSH para acelerar seu cresci-mento e aumentar sua produção de estradiol e inibina (figura 12). Mediante um seguimento ultrassonográfico dos ovários é possível identificar pou-cos dias depois um certo número de folículos, que por haver sido recrutados começam um período de crescimento acelerado. Durante alguns dias vários folículos crescem juntos, porém depois um deles é selecionado para continuar crescendo, enquanto que o restante do grupo deixam de fazê-lo e terminam sofrendo atresia. Através da ultrassom é possível identificar o folículo selecionado, agora chamado folículo domi-nante, já que sua trajetória de crescimento sofre um desvio com respeito a seguida pelo restante do grupo. Os folículos que não foram selecionados deixam de crescer e sofrem atresia já que deixam de possuir o suporte gonadotrópico de FSH, uma vez que as concentrações desse hormônio são suprimidos pela inibina e o estradiol produzidos pelo conjunto de folículos que conformam a onda folicular (figura 12), porém o folículo mais desenvolvido do grupo se converterá em dominante. A inibina atua diretamente a nível hipofisário para reduzir a secreção de FSH. Figura 12: onda folicular e relação dos níveis de FSH, estradiol e LH. Fonte: ZARCO, 2018. -/- Figura 13: Recrutamento, seleção e dominação folicular na espécie ovina e influência do FSH e LH nas fases. Fonte: SILVA, E. I. C. da, 2019. -/- A razão pela qual o folículo dominante é capaz de continuar seu desenvolvimento apesar da baixa nas concentrações de FSH é que o folículo é o único que alcançou o grau de progresso necessário para que apareçam os receptores para LH em suas células da granulosa. Esse processo permite ao folículo dominante ser estimulado pela LH, e que requeira baixas concentrações de FSH para manter seu desenvolvimento. A secreção de LH em forma de pulsos de baixa frequência (um pulso a cada quatro a seis horas), característica da fase lútea do ciclo estral; é suficiente para permitir que um folículo dominante continue crescendo por mais dias depois da sua seleção e que mais tarde mantenha-se viável durante alguns dias embora não aumentem de tamanho. Contu-do, se durante o período viável desse folículo não seja finalizada a fase lútea e não diminuam as concentrações de progesterona, o folículo terminará sofrendo atresia devido a exigência de um padrão de secreção acelerada de LH (aproximadamente um pulso por hora) durante o desenvolvimento pré-ovulatório, que somente pode ser produzido com a ausência da progesterona. Uma vez que um folículo dominante sofre atresia deixa de produzir inibina, pelo qual as concentrações de FSH podem elevar-se novamente para iniciar o recrutamento de outro grupo de folículos a partir da qual se origina uma nova onda folicular. Durante o ciclo estral de uma vaca podem gerar-se dois ou três ondas foliculares; somente em raros casos quatro. A etapa de dominância folicular da primeira onda na grande maioria dos casos não coincide com a regressão do corpo lúteo, pelo qual o primei-ro folículo dominante quase invariavelmente termina em atresia. Em algumas vacas o fo-lículo dominante da segunda onda ainda está viável quando se produz a regressão do corpo lúteo e acelera-se a secreção de LH, pelo qual esse segundo folículo dominante se converte em folículo pré-ovulatório e, ao final ovula. Em outros animais o segundo folícu-lo dominante também perde a sua viabilidade antes da regressão do corpo lúteo, por onde nesses animais se inicia uma terceira onda folicular, da qual surge o folículo que finalmen-te ovulará depois de produzir-se a regressão do corpo lúteo. Sem importar a onda em que se origine, uma vez que um folículo dominante é ex-posto a alta frequência de secreção de LH que se produz depois da regressão do corpo lúteo, aumenta ainda mais sua secreção de estradiol até que as altas concentrações desse hormônio comecem a exercer um feedback positivo para a secreção do LH. Isso provoca-rá a aceleração da frequência de secreção do LH até que os pulsos são tão frequentes que começam a ficar por cima e produzir-se o pico pré-ovulatório de LH, que é responsável pela realização da ovulação e a maturação final do ovócito. -/- •___DIFERENÇAS ENTRE ESPERMATOGÊNESE E OVOGÊNESE -/- Enquanto que na fêmea a ovogênese inicia-se durante a vida fetal, no macho a es-permatogênese começa na puberdade. Na fêmea, a partir de um ovócito primário se origi-na um óvulo; no macho, de um espermatócito primário se produzem, teoricamente, quatro espermatozoides. Outra característica interessante é que enquanto a fêmea já conta desde o nasci-mento com todos os ovócitos que necessitará na vida adulta, o macho necessitará chegar a puberdade para iniciar o desenvolvimento das células sexuais, já que ao nascer somente possui gonócitos precursores das células germinais, células de Sertoli e intersticiais. Na vida adulta de uma fêmea, o número de células germinais desaparece paulati-namente. Uma vez iniciada a espermatogênese no macho, a cada ciclo do epitélio seminí-fero as células germinais são renovadas mantendo a provisão para toda a vida reprodutiva. Na fêmea, a meiose sofre duas interrupções em seu transcurso, e no macho é ininterrupta. Figura 14: representação em diagramação comparativa do desenvolvimento da gametogênese. -/- Principais pontos abordados sobre as diferenças entre a gametogênese masculina e feminina: ❙ Na ovogênese a meiose contêm-se em duas ocasiões esperando acontecimentos externos para prosseguir. Já na espermatogênese não existe a suspensão da meiose. ❙ A espermatogênese é um processo contínuo, enquanto que a ovogênese pode completar exclusivamente um óvulo em cada ciclo estral; já que só pode ser completada por mais de um nas espécies que ovulam vários ovócitos no caso das porcas, cadelas, gatas etc. ❙ Na espermatogênese existem células de reserva que permitem a continuação du-rante toda a vida, enquanto que na ovogênese o número de ovócitos primários é limitado. A fêmea somente conta com os que nasceu, e eles não se dividem. ❙ Na espermatogênese obtém-se até 256 espermatozoides para cada espermatogo-nia que inicia o processo, enquanto que na ovogênese somente se obtém um óvulo a partir de cada ovócito primário. ❙ Durante a espermatogênese se produz uma metamorfose que transforma as es-permátides em espermatozoides. Na ovogênese não ocorre um processo análogo. ❙ Na espermatogênese, durante a meiose produzem-se quatro espermátides a partir de cada espermatócito primário. Na ovogênese se produz somente um óvulo a partir de cada ovócito primário; produz, ademais, dois corpos polares. ❙ Todos os óvulos que se produzem durante a ovogênese contém um cromossomo X, enquanto que a metade dos espermatozoides possuem um cromossomo Y e a outra metade um cromossomo X. ❙ Na espermatogênese produzem-se centenas ou dezenas de milhões de esperma-tozoides por dia, enquanto que na ovogênese se produz um ou alguns óvulos a cada ciclo estral. ❙ A espermatogênese produz gametas macroscópicos e com motilidade própria, enquanto que a ovogênese produz gametas grandes e imóveis. -/- REFERÊNCIAS BIBLIOGRÁFICAS -/- ABDEL-RAOUF, Mohammed et al. The postnatal development of the reproductive organs in bullswith special reference to puberty.(Including growth of the hypophysis and the adrenals). Acta endocrinologica, n. Suppl No. 49, 1960. ADONA, Paulo Roberto et al. Ovogênese e foliculogênese em mamíferos. Journal of Health Sciences, v. 15, n. 3, 2013. AERTS, J. M. J.; BOLS, P. E. J. Ovarian follicular dynamics: a review with emphasis on the bovine species. Part I: Folliculogenesis and pre‐antral follicle development. Reproduction in domestic animals, v. 45, n. 1, p. 171-179, 2010. AERTS, J. M. J.; BOLS, P. E. J. Ovarian follicular dynamics. A review with emphasis on the bovine species. Part II: Antral development, exogenous influence and future prospects. Reproduction in domestic animals, v. 45, n. 1, p. 180-187, 2010. ALBERTINI, David F.; CARABATSOS, Mary Jo. Comparative aspects of meiotic cell cycle control in mammals. Journal of molecular medicine, v. 76, n. 12, p. 795-799, 1998. AUSTIN, Colin Russell; SHORT, R. Reproduction in mammals. Cambridge, 1972. BAKER, T. G. Oogenesis and ovulation. In. Reproduction in Mammals I Germ Cells and Fertilization, p. 29-30, 1972. BEARDEN, Henry Joe et al. Reproducción animal aplicada. México: Manual Moderno, 1982. BIGGERS, John D.; SCHUETZ, Allen W. Oogenesis. University Park Press, 1972. BINELLI, Mario; MURPHY, Bruce D. Coordinated regulation of follicle development by germ and somatic cells. Reproduction, Fertility and Development, v. 22, n. 1, p. 1-12, 2009. CHIARINI-GARCIA, Helio; RUSSELL, Lonnie D. High-resolution light microscopic characterization of mouse spermatogonia. Biology of reproduction, v. 65, n. 4, p. 1170-1178, 2001. CHOUDARY, J. B.; GIER, H. T.; MARION, G. B. Cyclic changes in bovine vesicular follicles. Journal of animal science, v. 27, n. 2, p. 468-471, 1968. CLERMONT, Yves; PEREY, Bernard. Quantitative study of the cell population of the seminiferous tubules in immature rats. American Journal of Anatomy, v. 100, n. 2, p. 241-267, 1957. COSTA, DEILER SAMPAIO; PAULA, T. A. R. Espermatogênese em mamíferos. Scientia, v. 4, 2003. CUNNINGHAM, James. Tratado de fisiologia veterinária. Elsevier Health Sciences, 2011. CUPPS, Perry T. (Ed.). Reproduction in domestic animals. Elsevier, 1991. DA SILVA, Emanuel Isaque Cordeiro. Fisiologia Clínica do Ciclo Estral de Vacas Leiteiras: Desenvolvimento Folicular, Corpo Lúteo e Etapas do Estro. 2020. Acervo pessoal. DA SILVA, Emanuel Isaque Cordeiro. Fisiologia da Reprodução Animal: Ovulação, Controle e Sincronização do Cio. 2020. Acervo pessoal. DUKES, Henry Hugh; SWENSON, Melvin J.; REECE, William O. Dukes fisiologia dos animais domésticos. Editora Guanabara Koogan, 1996. EPIFANO, Olga; DEAN, Jurrien. Genetic control of early folliculogenesis in mice. Trends in Endocrinology & Metabolism, v. 13, n. 4, p. 169-173, 2002. ERICKSON, B. H. Development and senescence of the postnatal bovine ovary. Journal of animal science, v. 25, n. 3, p. 800-805, 1966. REFERÊNCIAS BIBLIOGRÁFICAS -/- FELDMAN, Edward C. et al. Canine and feline endocrinology-e-book. Elsevier health sciences, 2014. FUSCO, Giuseppe; MINELLI, Alessandro. The Biology of Reproduction. Cambridge University Press, 2019. GALINA-HIDALGO, Carlos Salvador. A study of the development of testicular function and an evaluation of testicular biopsy in farm animals. 1971. Tese de Doutorado. Royal Veterinary College (University of London). GALLICANO, G. Ian. Composition, regulation, and function of the cytoskeleton in mammalian eggs and embryos. Front Biosci, v. 6, p. D1089-1108, 2001. GILBERT, Scott F. Biología del desarrollo. Ed. Médica Panamericana, 2005. GNESSI, Lucio; FABBRI, Andrea; SPERA, Giovanni. Gonadal peptides as mediators of development and functional control of the testis: an integrated system with hormones and local environment. Endocrine reviews, v. 18, n. 4, p. 541-609, 1997. HAFEZ, Elsayed Saad Eldin; HAFEZ, Bahaa. Reprodução animal. São Paulo: Manole, 2004. HEDGER, Mark P. Testicular leukocytes: what are they doing?. Reviews of reproduction, v. 2, n. 1, p. 38-47, 1997. HUTSON, James C. Testicular macrophages. In: International review of cytology. Academic Press, 1994. p. 99-143. HYTTEL, P. Gametogênese. In. HYTTEL, Poul; SINOWATZ, Fred; VEJLSTED, Morten. Embriologia veterinária. São Paulo: Elsevier Brasil, 2012. JOHNSON, Martin H. Essential reproduction. Nova Jersey: John Wiley & Sons, 2018. JONES, Richard E.; LOPEZ, Kristin H. Human reproductive biology. Academic Press, 2013. KIERSZENBAUM, Abraham L.; TRES, Laura L. Primordial germ cell‐somatic cell partnership: A balancing cell signaling act. Molecular Reproduction and Development: Incorporating Gamete Research, v. 60, n. 3, p. 277-280, 2001. MATZUK, Martin M. et al. Intercellular communication in the mammalian ovary: oocytes carry the conversation. Science, v. 296, n. 5576, p. 2178-2180, 2002. MCLAREN, Anne. Germ and somatic cell lineages in the developing gonad. Molecular and cellular endocrinology, v. 163, n. 1-2, p. 3-9, 2000. MCKINNON, Angus O. et al. (Ed.). Equine reproduction. John Wiley & Sons, 2011. MERCHANT-LARIOS, Horacio; MORENO-MENDOZA, Norma. Onset of sex differentiation: dialog between genes and cells. Archives of medical research, v. 32, n. 6, p. 553-558, 2001. MINTZ, Beatrice et al. Embryological phases of mammalian gametogenesis. Embryological phases of mammalian gametogenesis., v. 56, n. Suppl. 1, p. 31-43, 1960. MORALES, M. E. et al. Gametogénesis. I. Revisión de la literatura, con enfoque en la ovogénesis. Medicina Universitaria, v. 8, n. 32, p. 183-9, 2006. NAKATSUJI, NORIO; CHUMA, SHINICHIRO. Differentiation of mouse primordial germ cells into female or male germ cells. International Journal of Developmental Biology, v. 45, n. 3, p. 541-548, 2002. NILSSON, Eric; PARROTT, Jeff A.; SKINNER, Michael K. Basic fibroblast growth factor induces primordial follicle development and initiates folliculogenesis. Molecular and cellular endocrinology, v. 175, n. 1-2, p. 123-130, 2001. REFERÊNCIAS BIBLIOGRÁFICAS -/- NORRIS, David O.; LOPEZ, Kristin H. The endocrinology of the mammalian ovary. In: Hormones and reproduction of vertebrates. Academic Press, 2011. p. 59-72. PEDERSEN, Torben. Follicle growth in the immature mouse ovary. European Journal of Endocrinology, v. 62, n. 1, p. 117-132, 1969. PINEDA, Mauricio H. et al. McDonald's veterinary endocrinology and reproduction. Iowa state press, 2003. ROSER, J. F. Endocrine and paracrine control of sperm production in stallions. Animal Reproduction Science, v. 68, n. 3-4, p. 139-151, 2001. RUSSELL, Lonnie D. et al. Histological and histopathological evaluation of the testis. International journal of andrology, v. 16, n. 1, p. 83-83, 1993. RÜSSE, I.; SINOWATZ, F. Gametogenese. Lehrbuch der Embryologie der Haustiere, p. 42-92, 1991. SAITOU, Mitinori; BARTON, Sheila C.; SURANI, M. Azim. A molecular programme for the specification of germ cell fate in mice. Nature, v. 418, n. 6895, p. 293-300, 2002. SALISBURY, Glenn Wade et al. Physiology of reproduction and artificial insemination of cattle. WH Freeman and Company., 1978. SAWYER, Heywood R. et al. Formation of ovarian follicles during fetal development in sheep. Biology of reproduction, v. 66, n. 4, p. 1134-1150, 2002. SCARAMUZZI, R. J.; MARTENSZ, N. D.; VAN LOOK, P. F. A. Ovarian morphology and the concentration of steroids, and of gonadotrophins during the breeding season in ewes actively immunized against oestradiol-17β or oestrone. Reproduction, v. 59, n. 2, p. 303-310, 1980. SEIDEL JR, G. E. et al. Control of folliculogenesis and ovulation in domestic animals: puberal and adult function. In: 9th International Congress on Animal Reproduction and Artificial Insemination, 16th-20th June 1980. II. Round tables. Editorial Garsi., 1980. p. 11-16. SKINNER, Michael K. Cell-cell interactions in the testis. Endocrine Reviews, v. 12, n. 1, p. 45-77, 1991. SMITZ, J. E.; CORTVRINDT, Rita G. The earliest stages of folliculogenesis in vitro. Reproduction, v. 123, n. 2, p. 185-202, 2002. SORENSEN, Anton Marinus. Reproducción animal: principios y prácticas. México, 1982. SUTOVSKY, Peter; MANANDHAR, Gaurishankar. Mammalian spermatogenesis and sperm structure: anatomical and compartmental analysis. In. The sperm cell: Production, maturation, fertilization, regeneration, p. 1-30, 2006. TAZUKE, Salli I. et al. A germline-specific gap junction protein required for survival of differentiating early germ cells. Development, v. 129, n. 10, p. 2529-2539, 2002. VAN STRAATEN, H. W. M.; WENSING, C. J. G. Leydig cell development in the testis of the pig. Biology of Reproduction, v. 18, n. 1, p. 86-93, 1978. TURNBULL, K. E.; BRADEN, A. W. H.; MATTNER, P. E. The pattern of follicular growth and atresia in the ovine ovary. Australian Journal of Biological Sciences, v. 30, n. 3, p. 229-242, 1977. WASSARMAN, Paul M. Gametogenesis. Londres: Academic Press, 2012. WROBEL, K.-H.; SÜß, Franz. Identification and temporospatial distribution of bovine primordial germ cells prior to gonadal sexual differentiation. Anatomy and embryology, v. 197, n. 6, p. 451-467, 1998. REFERÊNCIAS BIBLIOGRÁFICAS -/- ZARCO, L. Gametogénese. In. PORTA, L. R.; MEDRANO, J. H. H. Fisiología reproductiva de los animales domésticos. Cidade do México: FMVZ-UNAM, 2018. ZIRKIN, Barry R. et al. Endocrine and Paracrine Regulation of Mammalian Spermatogenesis. In: Hormones and Reproduction of Vertebrates. Academic Press, 2011. p. 45-57. -/- REALIZAÇÃO -/- . (shrink)

I present an image of humanity as the will to power expressed in context of affirmationand danger in the eternal return. Nietzsche argues the death of God not as a theological argument but as an existential challenge for humanity to be re-experienced. It is read in light of the eternal return: without ontological references or quasi-transcendentals, how is life to be lived? Deleuze contextualizes Nietzsche’s critique of nihilism qua a typology of active and reactive modes of being, however I go (...) beyond to provide what I consider an anthropological account. I do this by differentiating the will to power from individual willing and present the danger that an affirmation of life entails. Nietzsche challenges us with the eternal return. With this, one is led to realize that she is her own destruction (Untergehen) at the same time as her overture (Übergehen). She has the ability, power, capacity to overcome and self-create. With this realization one ought to remain truthful to this in form of truth-telling (Redlichkeit). Nietzsche projects humanity as a perilous crossing over from nihilism to affirmation with an embrace of an ethics of danger. This crossing over is a mark of life as the will to power. It is an overcoming of nihilism and the assurance amidst nihilism’s farce that the godhead is dead and that the eternal return is a daunting challenge we cannot escape from. With these, we are afforded an image of humanity as the will to power. (shrink)

This paper intends to further the understanding of the formal properties of (higher-order) vagueness by connecting theories of (higher-order) vagueness with more recent work in topology. First, we provide a “translation” of Bobzien's account of columnar higher-order vagueness into the logic of topological spaces. Since columnar vagueness is an essential ingredient of her solution to the Sorites paradox, a central problem of any theory of vagueness comes into contact with the modern mathematical theory of topology. Second, Rumfitt’s recent topological reconstruction (...) of Sainsbury’s theory of prototypically defined concepts is shown to lead to the same class of spaces that characterize Bobzien’s account of columnar vagueness, namely, weakly scattered spaces. Rumfitt calls these spaces polar spaces. They turn out to be closely related to Gärdenfors’ conceptual spaces, which have come to play an ever more important role in cognitive science and related disciplines. Finally, Williamson’s “logic of clarity” is explicated in terms of a generalized topology (“locology”) that can be considered an alternative to standard topology. Arguably, locology has some conceptual advantages over topology with respect to the conceptualization of a boundary and a borderline. Moreover, in Williamson’s logic of clarity, vague concepts with respect to a notion of a locologically inspired notion of a “slim boundary” are (stably) columnar. Thus, Williamson’s logic of clarity also exhibits a certain affinity for columnar vagueness. In sum, a topological perspective is useful for a conceptual elucidation and unification of central aspects of a variety of contemporary accounts of vagueness. (shrink)

This study adds to the existing literature on meaningful work by offering a cross-cultural perspective. Since work shapes the kind of person that we are and plays an important role in our well-being, some theorists have adopted a virtue theory approach to meaningful work using an Aristotelian-MacIntyrean framework. For lack of a better term, I will call this a western virtue theory. This paper presents a contemporary virtue-focused Buddhist perspective on the topic. While a virtue-ethics interpretation of Buddhism is (...) now widely accepted and has been applied to several issues, not much has been written about meaningful work using a Buddhist-Aristotelian comparative framework. Buddhism is an important cultural component not only of countries that are predominantly Buddhist, but of other societies that have come in contact with it. To develop a Buddhist framework, I draw heavily from the works of Buddhist scholars, particularly in the West who use a virtue framework in interpreting Buddhism. The aims of my essay are dual. The first is to articulate a straightforward application of Buddhism on the contemporary ethical discussion of meaningful work. The second is to discuss the similarities, clarify the differences, and demonstrate the strengths and weaknesses relative to each other of the Buddhist and the Western virtue theory perspectives. In my analysis, I argue that consideration of Buddhist perspective will enable us to construct a cross-cultural, inclusive, and pluralistic conceptual model for the deliberation of meaningful work that complements the Western virtue theory. (shrink)

Does the Ship of Theseus present a genuine puzzle about persistence due to conflicting intuitions based on “continuity of form” and “continuity of matter” pulling in opposite directions? Philosophers are divided. Some claim that it presents a genuine puzzle but disagree over whether there is a solution. Others claim that there is no puzzle at all since the case has an obvious solution. To assess these proposals, we conducted a cross-cultural study involving nearly 3,000 people across twenty-two countries, (...) speaking eighteen different languages. Our results speak against the proposal that there is no puzzle at all and against the proposal that there is a puzzle but one that has no solution. Our results suggest that there are two criteria—“continuity of form” and “continuity of matter”— that constitute our concept of persistence and these two criteria receive different weightings in settling matters concerning persistence. (shrink)

In his latest attack, even though he claims to be a practitioner of “close reading” (Wills 2018b, 34), it appears that Wills still has not bothered to read the paper in which I defend the thesis he seeks to attack (Mizrahi 2017a), or any of the papers in my exchange with Brown (Mizrahi 2017b; 2018a), as evidenced by the fact that he does not cite them at all. This explains why Wills completely misunderstands Weak Scientism and the arguments for (...) the quantitative superiority (in terms of research output and research impact) as well as qualitative superiority (in terms of explanatory, predictive, and instrumental success) of scientific knowledge over non-scientific knowledge. (shrink)

The Protagoras is the touchstone of Socrates’ moral intellectualist stance. The position in a nutshell stipulates that the proper reevaluation of a desire is enough to neutralize it.[1] The implication of this position is that akrasia or weakness of will is not the result of desire (or fear for that matter) overpowering reason but is due to ignorance. -/- Socrates’ eliminativist position on weakness of will, however, flies in the face of the common-sense experience regarding akratic action and thus Aristotle (...) was at pains to render Socrates’ account of moral incontinence intelligible. The key improvement Aristotle makes to Socrates’s model is to underscore that the conditioning of the akratic’s body plays a critical role in determining the power of one’s appetites and, accordingly, the capacity of one to resist the temptations these appetites present for rational evaluation. As Aristotle puts it, “For the incontinent man is like the people who get drunk quickly and on little wine, i.e., on less than most people.” (1151a 3-4). Aristotle presents what I shall call a somatic paradigm (i.e. the drunkard analogy) in order to tackle the problem of akrasia and it is this somatic solution that marks a significant improvement over Socrates’s intellectualist or informational model or so the tradition tells us. -/- In this paper, I wish to push back on the above Aristotelian explanation. I argue that when one fully examines Socrates’ account of weakness of will that Aristotle’s solution is less effective than is traditionally thought. In fact, Socrates can bring Aristotle’s model into his own; just as Aristotle absorbs what is right about Socrates’s model, namely, that akratic action utilizes reason but to a limited degree, Socrates in Meno (77C-78A) develops his own somatic model of weakness of will that connects to the intellectualist paradigm of the Protagoras. To achieve this rapprochement between the two models, I zero in on the description provided by Socrates of those individuals who desire bad things knowing they are bad as “ill-starred” or “bad spirited” (κακοδαίμων ). The “bad-spirited” is the coward and, in contrast to Aristotle’s drunkard, becomes fearful quickly from little danger. This additional somatic component, when connected to Socrates’s position on akrasia in Protagoras adds a new twist to Socrates’s model in the following way: while no one wishes to be ill-starred such that more harm than good will befall one, one may become so as a result of the bad choices one knowingly makes. -/- -/- [1] “After him came Socrates, who spoke better and further about this subject, but even he was not successful. For he used to make the virtues into sciences, and this is impossible. For the sciences all involve reason, and reason is to be found in the intellectual part of the soul. So that all the virtues, according to him arise in the rational part of the soul. The result is that in making the virtues into sciences he is doing away with the nonrational part of the soul and is thereby doing away with passion and character…” (Aristotle, Magna Moralia 1.1. 1182 a15-26). (shrink)

We often remember in the company of others. In particular, we routinely collaborate with friends, family, or colleagues to remember shared experiences. But surprisingly, in the experimental collaborative recall paradigm, collaborative groups remember less than their potential, an effect termed collaborative inhibition. Rajaram and Pereira-Pasarin (2010) argued that the effects of collaboration on recall are determined by “pre-collaborative” factors. We studied the role of 2 pre-collaborative factors—shared encoding and group relationship—in determining the costs and benefits of collaborative recall. In Experiment (...) 1, we compared groups of strangers who encoded alone versus together, before collaborating to recall. In Experiment 2, we compared groups of friends who encoded alone versus together, before collaborating to recall. We found that shared encoding abolished collaborative inhibition in both Experiments 1 and 2. But prior relationship did not influence collaborative inhibition over and above the effects of shared encoding. Regardless of encoding condition, collaborative group recall contained fewer intrusions than nominal group recall, and these benefits continued in subsequent individual recall. Our findings demonstrate that pre-collaborative factors—specifically shared encoding—have flow-on benefits for group and individual recall amount, but not recall accuracy. We discuss these findings in terms of self- and cross-cuing in collaborative recall. (shrink)

This paper tries to show that the naturalistic view of addiction is mired in contradictions that stem from reducing the addict to a weak-willed subject who loses control over his or her body. From a phenomenological perspective, addiction reveals itself to be a habit which eventually becomes harmful, but has its primary sources in the embodied needs of a worldly subject. The aim of this paper is to uncover the dimensions of the lived addiction that are neglected in (...) the contemporary naturalistic discourse: the lived-body and the worldly context of the addict. Firstly, we try to do justice to the variety of addictions by underlying that their new and surprising forms are determined by the intersubjective tissue wherein the subject operates. Secondly, the loss of control in addiction, how the subject deals with the tendency to satisfy a need, is experienced as powerlessness, as expressed in the accounts of ecstasy addicts regarding altered states of mind. The last section of this paper will argue that this sense of powerlessness cannot be equated with a weakness of the will because a strong, forceful will engenders the same vertigo of being prey to strange powers. The embodied aspect of addiction and the spontaneous, bodily need it saturates will clarify further this claim. (shrink)

Over the past two decades, virtue ethicists have begun to devote increasing attention to applied ethics. In particular, the application of virtue ethical frameworks to the environmental ethics debate has flourished. This chapter reviews recent contributions to the literature in this field and highlights some strengths and weaknesses of thinking about climate change through a virtue ethical lens. Section “Two Benefits of Virtue Ethical Approaches to Climate Change” explores two benefits of applying virtue ethics to climate change: (a) we (...) can better capture the phenomenology of our moral experience, and (b) we avoid the problem of inconsequentialism. Section “A Catalogue of Environmental Virtues” analyzes various practical proposals that have been put forward in the form of specific environmental virtues. Section “An Objection to Virtue-Oriented Approaches to Climate Change” reconstructs a fundamental objection to the idea of using a virtue ethical normative approach to tackling the urgent and imminent dangers of climate change. (shrink)