Extant theoretical work on the political resource curse implies that dependence on resource revenues should decrease autocracies’ likelihood of democratizing but not necessarily affect democracies’ chances of survival. Yet most previous empirical studies estimate models that are ill-suited to address this claim. We improve upon earlier studies, estimating a dynamic logit model that interacts a continuous measure of resource dependence with an indicator of regime type using data from 166 countries, covering the period from 1816-2006. We find that an increase (...) in resource dependence at time t - 1 increases the likelihood of autocratic persistence at t, but has no appreciable effect on democratic survival. We go beyond existing empirical studies to show that increases in resource dependence have persistent and substantial cumulative effects on autocracies' likelihood of becoming democratic over the long-term, showing that the total effect of resource dependence on regime type is much larger than the short-term (one period) effect indicates. (shrink)

In this dissertation, I seek to explain G.W.F. Hegel’s view that human accessible conceptual content can provide knowledge about the nature or essence of things. I call this view “Conceptual Transparency.” It finds its historical antecedent in the views of eighteenth century German rationalists, which were strongly criticized by Immanuel Kant. I argue that Hegel explains Conceptual Transparency in such a way that preserves many implications of German rationalism, but in a form that is largely compatible with Kant’s criticisms of (...) the original rationalist version. After providing background on Hegel’s relationship to the traditional rationalist theory of concepts and Kant’s challenge to it, I claim that Hegel’s central task is to provide a theory of conceptual content that allows a relationship to the objective world without being dependent on the specifically sensory aspect of the world, which Kant’s theory of concepts required. Since many interpreters deny that Hegel’s use of the term “concept” is comparable to other historical philosophers (or our own), I first show that Hegel’s critique of standard conceptions of concepts presupposes an agreement of subject matter. I then show how Hegel’s account of the “formal concept” provides the skeleton for a view of conceptual content that relies on negative relations between terms, rather than a relation to sensibility, to provide content. Hegel’s account of conceptual content is completed when he shows how a universal term is further specified so that it can determine singular objects. This occurs in its adequate form in a teleological process. I argue that Hegel’s account of teleology in the Science of Logic is an attempt to explain how and where Conceptual Transparency obtains. A teleological process is one in which a concept constitutes an object, and this means that a concept is perfectly adequate to express that thing’s nature and not merely to represent it. However, in the final chapter, I show that Hegel’s concept of teleology is meant paradigmatically to illuminate how human purposive processes have constituted a social world that is conceptually accessible to us. In this way, the primary “province” of Hegel’s rationalism is the human constructed world. (shrink)

Neil Sinhababu and I presented Backward Clock, an original counterexample to Robert Nozick’s truth-tracking analysis of propositional knowledge. Fred Adams, John Barker and Murray Clarke argue that Backward Clock is no such counterexample. Their argument fails to nullify Backward Clock which also shows that other tracking analyses, such as Dretske’s and one that Adams et al. may well have in mind, are inadequate.

This study is intended to measure the readiness of the public elementary school heads on the principles of sustainable leadership. This study utilized the mixed-method design. Creswell & Clark (2017), defined mixed methods research as a research approach that combines both qualitative and quantitative methods in a single study to gain a more comprehensive understanding of a research question or topic. This approach allows researchers to leverage the strengths of both qualitative and quantitative methods. The following major findings on (...) the quantitative aspect are: the school heads are slightly ready on the worldview principle while moderately ready to influence and complexity. However, they are highly ready to network, self-leadership, and work across boundaries. Positive themes emerged for the qualitative part with the results as: improved communication, increased motivation, and enhanced creativity. It can be concluded that the school heads are slightly ready when it comes to worldview principles. The SDO should create capacity training that could increase the readiness of the school heads on this principle of sustainable leadership. (shrink)

Alexius Meinong developed a notion of defective objects in order to account for various logical and psychological paradoxes. The notion is of historical interest, since it presages recent work on the logical paradoxes by Herzberger and Kripke. But it fails to do the job it was designed for. However, a technique implicit in Meinong's investigation is more successful and can be adapted to resolve a similar paradox discovered by Romane Clark in a revised version of Meinong's Theory of Objects (...) due to Rapaport. One family of paradoxes remains, but it is argued that they are unavoidable and relatively harmless. (shrink)

In “Beat the (Backward) Clock,” we argued that John Williams and Neil Sinhababu’s Backward Clock Case fails to be a counterexample to Robert Nozick’s or Fred Dretske’s Theories of Knowledge. Williams’ reply to our paper, “There’s Nothing to Beat a Backward Clock: A Rejoinder to Adams, Barker and Clarke,” is a further attempt to defend their counterexample against a range of objections. In this paper, we argue that, despite the number and length of footnotes, Williams is still (...) wrong. (shrink)

ABSTRACT Drawing inspiration from Fred Dretske, L. S. Carrier, John A. Barker, and Robert Nozick, we develop a tracking analysis of knowing according to which a true belief constitutes knowledge if and only if it is based on reasons that are sensitive to the fact that makes it true, that is, reasons that wouldn’t obtain if the belief weren’t true. We show that our sensitivity analysis handles numerous Gettier-type cases and lottery problems, blocks pathways leading to skepticism, and validates the (...) epistemic closure thesis that correct inferences from known premises yield knowledge of the conclusions. We discuss the plausible views of Ted Warfield and Branden Fitelson regarding cases of knowledge acquired via inference from false premises, and we show how our sensitivity analysis can account for such cases. We present arguments designed to discredit putative counterexamples to sensitivity analyses recently proffered by Tristan Haze, John Williams and Neil Sinhababu, which involve true statements made by untrustworthy informants and strange clocks that sometimes display the correct time while running backwards. Finally, we show that in virtue of employing the paradox-free subjunctive conditionals codified by Relevance Logic theorists instead of the paradox-laden subjunctive conditionals codified by Robert Stalnaker and David Lewis. (shrink)

In a recent very interesting and important challenge to tracking theories of knowledge, Williams & Sinhababu claim to have devised a counter-example to tracking theories of knowledge of a sort that escapes the defense of those theories by Adams & Clarke. In this paper we will explain why this is not true. Tracking theories are not undermined by the example of the backward clock, as interesting as the case is.

Some of the most forceful objections to William Wollaston's moral theory come from his early critics, namely, Thomas Bott (1688-1754), Francis Hutcheson (1694-1746), and John Clarke of Hull (1687-1734). These objections are little known, while the inferior objections of Hume, Bentham, and later prominent critics are familiar. This fact is regrettable. For instance, it impedes a robust understanding of eighteenth-century British ethics; also, it fosters a questionable view as to why Wollaston's theory, although at first well received, soon faded in (...) esteem among philosophers. This paper gives Wollaston's early critics some of the attention they deserve. It reconstructs some of their objections to Wollaston's philosophy, addresses replies to those objections, and shows that despite some minor flaws, the objections succeed. A fact that becomes clear is that Wollaston's philosophy had suffered devastating criticism years before Hume wrote anything against it. (shrink)

This paper challenges Francis Hutcheson's and John Clarke of Hull's alleged demonstrations that William Wollaston's moral theory is inconsistent. It also present a form of the inconsistency objection that fares better than theirs, namely, that of Thomas Bott (1688-1754). Ultimately, the paper shows that Wollaston's moral standard is not what some have thought it to be; that consequently, his philosophy withstands the best-known efforts to expose it as inconsistent; and further, that one of the least-known British moralists is more important (...) than hitherto thought, in that he uncovers the inconsistency Clarke and Hutcheson try in vain to elicit. (shrink)

In a well-known footnote in Book 3 of his Treatise of Human Nature, Hume calls William Wollaston's moral theory a "whimsical system" and purports to destroy it with a few brief objections. The first of those objections, although fatally flawed, has hitherto gone unrefuted. To my knowledge, its chief error has escaped attention. In this paper I expose that error; I also show that it has relevance beyond the present subject. It can occur with regard to any moral theory which, (...) like Wollaston's, locates the wrongness of an act in a property that can reside in non-actions no less than in actions. (shrink)

Abstract Scientific discoveries must have more impact on philosophy (Bechtel, 2001. Part. I.I.). That is the thesis of the American professor of philosophy William Bechtel. Applications of the insights from the neurosciences could perhaps lead to a breakthrough in solving metaphysical and religious questions. Philosophers must assume the task of building bridges between the exact (and cognitive) sciences and contemporary philosophy (Bechtel, 2002. 49). This paper is a critical analysis of the promises of a relatively new discipline: Neurophilosophy.

If the world itself is metaphysically indeterminate in a specified respect, what follows? In this paper, we develop a theory of metaphysical indeterminacy answering this question.

Reshaping the neo-Aristotelian doctrines about the human soul was Descartes’s most spectacular enterprise, which gave birth to some of the sharpest debates in the Republic of Letters. Neverthe- less, it was certainly Descartes’s intention, as already expressed in the Discours de la méthode, to show that his new metaphysics could be supplemented with experimental research in the field of medicine and the conservation of life. It is no surprise then that several natural philosophers and doctors, such as Henricus Regius from (...) Utrecht, who had studied in Padua with William Harvey, rallied in support, in order to gain a more substantial theoretical basis for their research. Taking as his ground some general metaphysical assumptions, such as the existence of God, the immortality of the soul, and perhaps the separability of the pure understanding, Regius intended to secure a new philosophy of man, which was able to reflect his medical interests and complement his account of human nature. This is the story that is now gaining currency, and it is surely accurate, at least in part. Desmond Clarke has recently defended the same view1, based on the remarkable studies of the Utrecht scholars Theo Verbeek and Erik-Jan Bos. Here I would like to challenge some aspects of this view and ask how Regius, who was perceived as the philosopher most closely associated with Descartes, became a betrayer of his mentor. (shrink)

To meet the luck objection to incompatibilism, philosophers such as Timothy O’Connor, Randolph Clark, and William Rowe resurrected the Reidian notion of agent causation, which implies the “Substance-Causal Thesis” (SCT): some causes are fundamentally substances, not events. I examine an objection to SCT by C. D. Broad, developed by Carl Ginet, that substances cannot cause events because substances cannot explain why events happen when they do. The objection fails as it rests on a demand for contrastive explanations of free (...) actions. However, I show that a slightly different objection succeeds in showing SCT false. (shrink)

Panpsychism, the view that consciousness is present everywhere at the fundamental level of reality, has established itself as an increasingly popular option in the philosophy of mind. Situated between substance dualism and reductive physicalism, panpsychism aims to capture the intuitions behind both, integrating consciousness into the physical world without explaining it in terms of purely physical facts. In this thesis, I offer a defence of panpsychism. -/- First, I examine influential arguments against physicalism, such as Thomas Nagel’s (1974, 1979) perspective-based (...) proposal, Frank Jackson’s (1982) knowledge argument, David Chalmers’ (1996, 2010) conceivability argument, as well as vagueness arguments (Antony 2006a; Tye 1996). I argue that none of them offers a knockdown case against physicalism, particularly because of the threat presented by the phenomenal concept strategy (Chalmers 2007; Papineau 2007a), though they suggest panpsychism as a promising alternative that avoids many common objections. -/- Second, I discuss independent arguments for panpsychism, including the Russellian monist view (Goff 2017; Russell 1927/1992), the intrinsic nature argument (Seager 2006; Strawson 2006), recent developments in the literature as presented by Hedda Hassel Mørch (2018, 2020) and Luca Dondoni (2022), Tye’s (2021b) representational panpsychism based on the vagueness argument, as well as cosmopsychism (Nagasawa & Wager 2016; Shani 2015) – an alternative to panpsychism that shares its aims whilst claiming to avoid its shortcomings. -/- Third, I address the most pressing objection to panpsychism: the combination problem or the question of how fundamental consciousness can combine to lead to complex consciousness (James 1890). Focusing especially on the subject-summing version of the combination problem or the issue of how small subjects can combine to form complex subjects, I go over various proposals for either solving or avoiding it, such as Philip Goff’s (2016) phenomenal bonding relation and William Seager’s (2010) combinatorial infusion proposal, arguing against both and agreeing at the end with Sam Coleman (2014), who advocates that subject-summing is demonstrably incoherent. -/- However, as I argue in the fourth and final chapter, the panpsychist still has an option that avoids the subject-summing problem, while also circumventing the objections faced by the alternative view of cosmopsychism. Inspired though not reliant on the philosophy of Gottfried Wilhelm Leibniz (1902/2005), I introduce what I call monadic panpsychism, the view that the phenomenal character of any given consciousness-bearing physical ultimate is determined by its relations to other such ultimates featuring in the relevant causal structure. -/- The theory consists of two key claims. The first is that phenomenal qualities are relational rather than intrinsic. This view has precedent in literature on the philosophy of mind, such as in Rudolf Carnap (1928), Gottlob Frege (1956), Moritz Schlick (1959), as well as more recently in David Hilbert and Mark Kalderon (2000) and Austen Clark (2000), though not in the context of panpsychism. -/- The second claim is that physical ultimates only possess a very basic form of consciousness necessary for experiencing as such. There are many ways to conceptualise this basic consciousness: non-relational or intrinsic, rudimentary and non-specific, a point of view without experiences, the minimal subject, a mere conduit for experience, phenomenal space, etc. Russellian panpsychists offer a more detailed proposal in which every physical ultimate has an appropriate associated type of experience. For example, all quarks have the same quark-type of experience, assuming for the sake of discussion that quarks are ultimates. Still, arguing for a more minimal notion, as I do, requires making less claims and should not be controversial to any panpsychist. -/- So, what follows from these two claims? I propose that the relational constitution of phenomenal qualities has its endpoint at the fundamental level rather than at the level of a combined complex or emergent subject. Put simply, physical ultimates guarantee the basic consciousness or the point of view that I occupy, while the relational structure constitutes my rich and full human experience. So to speak, relationally constituted phenomenal qualities ‘anchor’ themselves in physical ultimates. As long as these relations result in a phenomenally unified experience, which is an uncontroversial thesis, then no matter where that process reaches the end of its causal chain, it will necessarily be experienced from a subjective point of view. -/- Since only qualities but not subjects need to combine, my proposal avoids the subject-summing version of the combination problem, which is arguably an insurmountable challenge to other forms of panpsychism. Because of this, I conclude that my theory contributes to the field, serving as a good starting point for further developments of neither combinatory nor emergent panpsychism with regard to subjects. (shrink)

From Hegel to Engels, Sartre and Ruyer (Ruyer, 1933), to name only a few, materialism is viewed as a necropolis, or the metaphysics befitting such an abode; many speak of matter’s crudeness, bruteness, coldness or stupidity. Science or scientism, on this view, reduces the living world to ‘dead matter’, ‘brutish’, ‘mechanical, lifeless matter’, thereby also stripping it of its freedom (Crocker, 1959). Materialism is often wrongly presented as ‘mechanistic materialism’ – with ‘Death of Nature’ echoes of de-humanization and hostility to (...) the Scientific Revolution (which knew nothing of materialism!), also a powerful Christian theme in Cudworth, Clarke and beyond (Overhoff, 2000). Here I challenge this view, building on some aspects of Israel’s Radical Enlightenment concept (Israel, 2001), which has been controversial but for my purposes is a useful claim about the dissemination of a home-grown Spinozism, sometimes reformulated as an ontology of the life sciences, an aspect Israel does not address (compare Secrétan et al., eds., 2007; Citton, 2006). First, I examine some ‘moments’ of radical Enlightenment materialism such as La Mettrie and Diderot (including his Encyclopédie entry “Spinosiste”), but also anonymous, clandestine texts such as L’Âme Matérielle, to emphasize their distinctive focus on the specific existence of organic beings. Second, I show how this ‘embodied’, non-mechanistic character of Enlightenment ‘vital materialism’ makes it different from other episodes, and perhaps more of an ethics than is usually thought (also via the figure of the materialist as ‘laughing philosopher’). Third, I reflect on what this implies for our image of the Enlightenment – no longer a Frankfurt School and/or Foucaldian vision of ‘discipline’, regimentation and order (as in Mayr, 1986) – but ‘vital’, without, conversely, being a kind of holist vitalism “at odds with the universalizing discourse of Encyclopedist materialism, with its insistence on the uniformity of nature and the universality of physical laws” (Williams, 2003): vital materialism is still materialism. Its ethics tends towards hedonism, but its most radical proponents (Diderot, La Mettrie and later Sade) disagree as to what this means. (shrink)

While there has been significant discussion in the health sciences and ethics literatures about problems associated with publication practices (e.g., ghost- and gift-authorship, conflicts of interest), there has been relatively little practical guidance developed to help researchers determine how they should fairly allocate credit for multi-authored publications. Fair allocation of credit requires that participating authors be acknowledged for their contribution and responsibilities, but it is not obvious what contributions should warrant authorship, nor who should be responsible for the quality and (...) content of the scientific research findings presented in a publication. In this paper, we review arguments presented in the ethics and health science literatures, and the policies or guidelines proposed by learned societies and journals, in order to explore the link between author contribution and responsibility in multi-author multidisciplinary health science publications. We then critically examine the various procedures used in the field to help researchers fairly allocate authorship. (shrink)

We discuss arguments against the thesis that the world itself can be vague. The first section of the paper distinguishes dialectically effective from ineffective arguments against metaphysical vagueness. The second section constructs an argument against metaphysical vagueness that promises to be of the dialectically effective sort: an argument against objects with vague parts. Firstly, cases of vague parthood commit one to cases of vague identity. But we argue that Evans' famous argument against will not on its own enable one to (...) complete the reductio in the present context. We provide a metaphysical premise that would complete the reductio, but note that it seems deniable. We conclude by drawing general morals from our case study. (shrink)

Background There has been debate on whether a global or unified field of bioethics exists. If bioethics is a unified global field, or at the very least a closely shared way of thinking, then we should expect bioethicists to behave the same way in their academic activities anywhere in the world. This paper investigates whether there is a 'global bioethics' in the sense of a unified academic community. Methods To address this question, we study the web-linking patterns of bioethics institutions, (...) the citation patterns of bioethics papers and the buying patterns of bioethics books. Results All three analyses indicate that there are geographical and institutional differences in the academic behavior of bioethicists and bioethics institutions. Conclusion These exploratory studies support the position that there is no unified global field of bioethics. This is a problem if the only reason is parochialism. But these regional differences are probably of less concern if one notices that bioethics comes in many not always mutually understandable dialects. (shrink)

This study aimed to understand the preserved elements of self-identity in persons with moderate to severe dementia attributable to Alzheimer’s disease. A semi-structured interview was developed to explore the narrative self among residents with dementia in a residential care facility and residents without dementia in an independent living setting. The interviews were transcribed verbatim from audio recordings and analyzed for common themes, while being sensitive to possible differences between the groups. The participants with dementia showed evidence of self-reference even though (...) losses in explicit memory were evident. The most noticeable difference between the two groups was time frame reference. Nonetheless, all participants showed understanding of their role in relationships and exhibited concrete preferences. Our findings suggest that memory loss and other cognitive deficits associated with moderate to severe dementia do not necessarily lead to a loss of “self.”. (shrink)

In Canada, there are currently no guidelines at either the federal or provincial level regarding the provision of kidney transplantation services to foreign nationals (FN). Renal transplant centres have, in the past, agreed to put refugee claimants and other FNs on the renal transplant waiting list, in part, because these patients (refugee claimants) had health insurance through the Interim Federal Health Programme to cover the costs of medication and hospital care. However, severe cuts recently made to this programme have forced (...) clinicians to question whether they should continue with transplants for FNs, for financial and ethical reasons. This paper first examines different national policies (eg, in Canada, USA, France and the UK) to map the diversity of approaches regarding transplantation for FNs, and then works through different considerations commonly used to support or oppose the provision of organs to these patients: (1) the organ shortage; (2) the free-rider problem; (3) the risk of becoming a transplant destination; (4) the impact on organ donation rates; (5) physicians’ duties; (6) economic concerns; (7) vulnerability. Using a Canadian case as a focus, and generalising through a review of various national policies, we analyse the arguments for and against transplantation for FNs with a view to bringing clarity to what is a sensitive political and clinical management issue. Our aim is to help transplant centres, clinicians and ethicists reflect on the merits of possible options, and the rationales behind them. (shrink)

Genetic testing in the workplace is a technology both full of promise and fraught with ethical peril. Though not yet common, it is likely to become increasingly so. We survey the key arguments in favour of such testing, along with the most significant ethical worries. We further propose a set of pragmatic criteria, which, if met, would make it permissible for employers to offer (but not to require) workplace genetic testing.

When looking at a scene, observers feel that they see its entire structure in great detail and can immediately notice any changes in it. However, when brief blank fields are placed between alternating displays of an original and a modified scene, a striking failure of perception is induced: identification of changes becomes extremely difficult, even when changes are large and made repeatedly. Identification is much faster when a verbal cue is provided, showing that poor visibility is not the cause of (...) this difficulty. Identification is also faster for objects mentioned in brief verbal descriptions of the scene. These results support the idea that observers never form a complete, detailed representation of their surroundings. In addition, results also indicate that attention is required to perceive change, and that in the absence of localized motion signals it is guided on the basis of high-level interest. (shrink)

Surveillance programs supporting the management of One Health issues such as antibiotic resistance are complex systems in themselves. Designing ethical surveillance systems is thus a complex task (retroactive and iterative), yet one that is also complicated to implement and evaluate (e.g., sharing, collaboration, and governance). The governance of health surveillance requires attention to ethical concerns about data and knowledge (e.g., performance, trust, accountability, and transparency) and empowerment ethics, also referred to as a form of responsible self-governance. Ethics in reflexive governance (...) operates as a systematic critical-thinking procedure that aims to define its value: What are the “right” criteria to justify how to govern “good” actions for a “better” future? The objective is to lay the foundations for a methodological framework in empirical bioethics, the rudiments of which have been applied to a case study to building reflexive governance in One Health. This ongoing critical thinking process involves “mapping, framing, and shaping” the dynamics of interests and perspectives that could jeopardize a “better” future. This paper proposes to hybridize methods to combine insights from collective deliberation and expert evaluation through a reflexive governance functioning as a community-based action-ethics methodology. The intention is to empower individuals and associations in a dialogue with society, which operation is carried out using a case study approach on data sharing systems. We based our reasoning on a feasibility study conducted in Québec, Canada (2018–2021), envisioning an antibiotic use surveillance program in animal health for 2023. Using the adaptive cycle and governance techniques and perspectives, we synthesize an alternative governance model rooted in the value of empowerment. The framework, depicted as a new “research and design (R&D)” practice, is linking operation and innovation by bridging the gap between Reflexive, Evaluative, and Deliberative reasonings and by intellectualizing the management of democratizing critical thinking locally (collective ethics) by recognizing its context (social ethics). Drawing on the literature in One Health and sustainable development studies, this article describes how a communitarian and pragmatic approach can broaden the vision of feasibility studies to ease collaboration through public-private-academic partnerships. The result is a process that “reassembles” the One Health paradigm under the perspective of global bioethics to create bridges between the person and the ecosystem through pragmatic ethics. (shrink)

Promotion of prescription drugs may appear to be severely limited in some jurisdictions due to restrictions on direct-to-consumer advertising. However, in most jurisdictions, strategies exist to raise consumer awareness about prescription drugs, notably through the deployment of direct-to-consumer information campaigns that encourage patients to seek help for particular medical conditions. In Canada, DTCI is presented by industry and regulated by Health Canada as being purely informational activities, but their design and integration in broader promotional campaigns raise very similar ethical concerns (...) as those associated with DTCA. Specifically, DTCI can be an effective means of familiarizing the public with the scope and benefits of a particular prescription drug and so, like DTCA, can promote increased patient-consumer demand and thus a problematic rise in the prescribing and use of medications that may be neither the most appropriate nor the most cost-effective. Yet, with DTCI the industry is playing within the existing rules and regulations set by health regulators. To respond appropriately to this regulatory incoherence, we argue that DTCI should be regulated as a type of direct-to-consumer indirect advertising. Even if the case and specific regulations presented here are Canadian, the implications extend to every country that has a partial or total prohibition on DTCA. (shrink)

OBJETIVO -/- O estudante de Zootecnia e de Veterinária, quando se depara com a produção animal, um dos pilares importantes é a reprodução, uma vez que é a perpetuação da espécie, seja para gerar filhas de uma vaca campeã em produção leiteira e de um touro com rusticidade e com aptidão produtiva de corte, ou mesmo para reposição de um plantel, o mesmo deve estar consciente de que esse ramo é de extrema responsabilidade, já que estará intimamente lidando com a (...) vida e com um investimento que pode gerar lucros em demasia para a propriedade ou, se mal feito o manejo da reprodução, trazer sérios transtornos para a mesma. -/- Nesse trabalho, o estudante revisará os sucessos da puberdade e estacionalidade reprodutiva relacionando-os com os processos endócrinos e os fatores que afetam sua manifestação como os nutricionais, para compreender a maneira ao qual podem ser manipuladas. -/- -/- • _____INTRODUÇÃO -/- A puberdade marca o início da vida reprodutiva do animal, permitindo integrar o indivíduo ao seu ciclo produtivo. A estacionalidade é uma característica de adaptação que algumas espécies desenvolveram para fazer garantir a eficiência da reprodução e a sobrevivência dos filhotes. -/- -/- • _____PUBERDADE -/- A puberdade é atingida quando o animal é capaz de produzir e liberar gametas viáveis e funcionais (férteis). Na fêmea esse fato ocorre na primeira ovulação, que geralmente coincide com a manifestação do comportamento do cio; e nos machos durante a primeira ejaculação com espermatozoides viáveis. -/- Do ponto de vista da produção animal, puberdade prematura ou precoce, é importante para poder permitir a incorporação dos animais ao ciclo produtivo o mais rapidamente possível. No caso de touros holandeses, por exemplo, é desejável que produzam sêmen precocemente para incorporá-los a prova de progênie; nas fêmeas, entretanto, deve-se considerar que nem sempre é conveniente usar o primeiro ciclo ou cio para reprodução. É o caso das marrãs (porcas primíparas), onde é benéfico esperar até o segundo ou terceiro estro para aumentar o tamanho da ninhada. Também pode ser vantajoso esperar que o indivíduo alcance sua maturidade sexual, que ocorre quando a fêmea consegue se reproduzir sem sofrer efeitos adversos. A ovelha nascida na primavera, por exemplo, pode engravidar no outono seguinte e dar à luz no primeiro ano de vida, mas seu crescimento pode ser afetado; o mesmo ocorre com a novilha, em que o acasalamento precoce pode promover distorcia por falta de desenvolvimento pélvico. -/- A puberdade é um processo gradual e está intimamente relacionada à taxa de crescimento e ao metabolismo energético. O recém-nascido usa energia para funções vitais, principalmente termorregulação; esse feito se deve ao fato de os jovens possuírem uma superfície corporal muito elevada em relação ao seu volume. Durante o desenvolvi-mento subsequente dos tecidos também há prioridade no uso de nutrientes, que inicialmente favorecem o desenvolvimento do tecido ósseo e muscular, e uma vez que estes atingem determinado tamanho de acordo com as condições genéticas do indivíduo, inicia-se o desenvolvimento do tecido adiposo, que é indicativa de um reservatório de energia. É importante ressaltar que existe uma interação entre a genética e o meio ambiente, de forma que o potencial genético só será expresso se o meio ambiente for favorável. -/- Para que a ovulação ocorra, é necessário considerar o funcionamento do eixo hipotálamo-hipófise-gonodal. O aumento da frequência pulsátil do GnRH hipotalâmico e em consequência do LH hipofisário provoca a maturação do folículo em nível gonodal, o que aumenta a produção de estrógenos. O aumento dos estrogênios causa, por feedback positivo no hipotálamo, a liberação do pico pré-ovulatório de LH e, consequentemente, a ovulação. Na fase pré-púbere, a frequência dos pulsos de GnRH e LH é muito baixa e insuficiente para provocar a maturação folicular, pois o hipotálamo é inibido e, portanto, não ocorre ovulação. -/- A geração pulsátil de GnRH no momento reprodutivo adequado para desencadear o início da puberdade depende de uma rede neural complexa que, além dos neurônios GnRH, inclui outros neurônios e células da glia; ele também integra vários sinais internos e externos para o corpo. A morfologia dos neurônios GnRH também é única, uma vez que seus dendritos também podem funcionar como axônios, dando-lhes uma função distinta. A geração de pulsos também indica a necessidade de sincronização entre subpopulações de neurônios GnRH, que, acima de tudo, parece ser extrínseca a esses neurônios e envolve múltiplos hormônios e neurotransmissores -/- Se dois níveis de conexões aferentes são considerados, estima-se que cada neurônio de GnRH pode ser conectado a cerca de cinco milhões de outros neurônios; milhares de genes, então, podem estar envolvidos no processo da puberdade. A importância funcional e hierárquica de cada um desses genes no controle dos neurônios GnRH, juntamente com outros fatores neuronais e gliais, pode diferir entre as espécies. Existem, no entanto, componentes fundamentais que parecem ser comuns a todos os mamíferos e que se situam nos níveis hierárquicos mais elevados, ajudando a compreender a progressão do processo puberal. Assim, todas as espécies de mamíferos estudadas, por exemplo, têm aglomerados de neurônios kisspeptinérgicos (que secretam kisspeptina), envolvidos na regulação da secreção tônica e secreção cíclica de GnRH, que também se classifica como o elemento mais alto na hierarquia desse complexo neuronal após considerar os neurônios GnRH. -/- Sabe-se que o eixo hipotálamo-hipofisário-gonodal está ativo desde as primeiras fases da vida do indivíduo, mesmo antes do nascimento em certas espécies. A secreção de GnRH, no entanto, é suprimida mais tarde no desenvolvimento e permanece dessa forma até o período pré-púbere, quando será reativada gradualmente. -/- Por várias décadas, a supressão e reinicialização dos pulsos de GnRH foi atribuída a uma hipótese conhecida como teoria gonadostat que afirma que o centro tônico do hipotálamo é inibido devido à sua sensibilidade ao mecanismo de feedback negativo dos esteroides gonodais, é aumentado; portanto, o GnRH e a consequente secreção de gonadotrofinas (FSH e LH) são insuficientes para a ocorrência da maturação folicular e espermatogênese. Essa sensibilidade diminui progressivamente à medida que a puberdade se aproxima. -/- Sabe-se agora que existem fatores não gonodais que agem em paralelo com os esteroides para mediar mudanças no feedback negativo que também são específicos da espécie. -/- Na fêmea, o centro gerador de pulso cíclico também deve ser considerado, o qual é responsável por iniciar a primeira ovulação. O centro cíclico é composto por uma segunda subpopulação de neurônios GnRH que é reativada por meio de uma complexa interação entre vários sistemas neuronais inibitórios (que devem reduzir progressiva-mente sua influência) e outros sistemas excitatórios, que, por sua vez, operam por meio de diferentes neurotransmissores, como o ácido γ-amino-butírico (GABA) e seus receptores, glutamato, óxido nítrico e neuropeptídio Y (NPY). Esses fatores, juntamente com as alterações morfológicas observadas nos neurônios do GnRH à medida que a puberdade se aproxima, e com as interações e sinais aferentes das células gliais, levam a um padrão de progressão linear que culminará na reativação do centro cíclico. Esse processo era conhecido anteriormente como teoria da maturação central e faz parte das mudanças que configuram o processo para chegar à puberdade. A elevação nas concen-trações de estradiol subsequente à reativação gradual do centro gerador de pulso tônico GnRH provavelmente permitirá a maturação final do centro cíclico. -/- A forma como cada organismo estabelece o momento certo para iniciar as mudanças que levam à puberdade é conhecido; a existência de algum mecanismo neurobiológico que constitui um relógio interno pode ser considerada. No entanto, esse mecanismo afetaria principalmente o desenvolvimento neuronal no nível central; também seria difícil compará-lo com a maneira pela qual fatores externos ao indivíduo afetam o início da puberdade. Nessa perspectiva, um sistema que permita receber informações completas sobre o crescimento e desenvolvimento do indivíduo poderia ser mais prático. Os mediadores desse sistema incluem o hormônio do crescimento, IGF-I, leptina e outros substratos metabólicos. A leptina em particular, que sinaliza as reservas de tecido adiposo, é um dos elementos mais importantes e, embora não determine quando começa a puberdade, se atua como fator permissivo para que o processo progrida, uma vez que excede um nível limite. A consideração do estágio de desenvolvimento do animal para o início da puberdade era anteriormente conhecida como o peso corporal crítico ou teoria do lipostato. É importante considerar que as três teorias mencionadas não são exclusivas. -/- O mecanismo da puberdade nos machos é semelhante ao já descrito; entretanto, deve-se lembrar que no macho o centro cíclico não está ativo. À medida que a puberdade se aproxima, o crescimento testicular é desencadeado e, em ruminantes e suínos, o pênis que estava preso à mucosa prepucial é gradualmente liberado. -/- -/- • _____FATORES QUE INFLUENCIAM A PUBERDADE -/- Os animais podem manifestar a puberdade de três formas diferentes. Pode ser tardia e o animal demorar para estar apto a reprodução; precoce e o animal entrar na vida reprodutiva antes do esperado ou pode ser normal e o animal estar com boa conformação e idade. Para tanto, alguns fatores podem interferir à manifestação da puberdade pelos animais como a genética, idade e peso, nutrição, fotoperíodo e o próprio manejo adotado. -/- -/- Genética -/- O genótipo afeta a idade da puberdade, pois algumas raças são anteriores a outras. Nos bovinos, as raças europeias atingem a puberdade antes dos zebuínos, isto é, uma novilha ou novilho da raça holandesa atinge a puberdade primeiro que os animais da mesma idade e do mesmo peso da raça nelore, por exemplo. -/- Da mesma forma, as porcas da raça chinesa Meishan atingem a puberdade por volta dos 115 dias de idade, metade da idade das raças brancas. As ovelhas de raças de corte, da mesma forma, são mais precoces que os produtores de lã. As raças pequenas, da mesma forma, são geralmente mais precoces, pelo menos em bovinos (jersey x guzerá) e em caninos. Os híbridos, por outro lado, apresentam puberdade mais precoce que os puros, devido ao efeito da heterose. Por este motivo, em certas espécies são utilizadas linhas híbridas. -/- -/- Idade e peso -/- A tabela 1 mostra a idade média de início da puberdade em espécies domésticas. O peso vivo (PV) adulto é mais relevante para a idade na puberdade nos ruminantes, enquanto em suínos é menos decisivo. A tabela também apresenta a porcentagem de peso corporal necessária para a puberdade ocorrer de forma natural. -/- -/- Tabela 1: Idade e peso a puberdade das espécies domésticas -/- Espécie -/- Fêmea (meses) -/- Macho (meses) -/- PV adulto (%) -/- Gado holandês -/- 11 (8-15) -/- 11 (7-18) -/- 30-40 -/- Gado brahman -/- 19 -/- 17 -/- 45-60 -/- Caprinos e ovinos -/- 7 (4-14) -/- 7 (6-9) -/- 40-60 -/- Suínos -/- 6 (5-7) -/- 7 (5-8) -/- 75 -/- Equinos -/- 18 (12-19) -/- 14 (10-24) -/- - -/- Caninos -/- 12 (6-24) -/- 9 (5-12) -/- - -/- Felinos -/- 8 (4-12) -/- 9 (8-10) -/- - -/- Fonte: VALENCIA, 2018. -/- Nutrição -/- Como a puberdade está relacionada à taxa de crescimento, os animais que recebem uma nutrição adequada e balanceada apresentarão puberdade em uma idade mais jovem, ou seja, mais precocemente; ao contrário, a puberdade será tardia nos animais que sofreram restrição alimentar, que estão desnutridos ou que tiveram seu crescimento afetado por doenças infecciosas ou parasitárias. A superalimentação também não é recomendada, pois pode alterar tanto os sinais que são recebidos pelo hipotálamo quanto sua resposta a eles. -/- Logo, o manejo alimentar adotado deve estar de acordo com as normas estabeleci-das pelos especialistas na área, principalmente no tocante as exigências nutricionais que devem servir de regra na propriedade. Sendo assim, os animais entrarão em puberdade com as taxas de alta qualidade o que afetará positivamente na prole futura e dará retorno lucrativo ao proprietário. -/- -/- Época do ano (Fotoperíodo) -/- Em fêmeas de espécies sazonais, como ovelhas e cabras, existem certos requisitos de fotoperíodo que devem ser atendidos para que a puberdade ocorra. Nessas espécies, um período de exposição a dias longos é necessário, seguido por outro de exposição a dias curtos. Na verdade, os cordeiros e cabritos nascidos fora da estação, mesmo que tenham atingido o peso necessário, terão que esperar até o outono seguinte (a estação reprodutiva) para atingir a puberdade. Os machos, por outro lado, não estão sujeitos a essas limitações nos requisitos fotoperiódicos para apresentar a puberdade. -/- Em novilhas nascidas no outono, por outro lado, a puberdade ocorre antes de um ano de idade, no verão seguinte ou no início do outono, mais cedo do que nas nascidas na primavera, devido à exposição a longos dias durante os primeiros seis meses do ano após seu nascimento aceleram seu crescimento. Em gatos, o aumento do fotoperíodo também acelera o início da puberdade. -/- Em ovelhas e novilhas, a primeira ovulação que ocorre ao entrar na puberdade é silenciosa; ou seja, não é acompanhada de sinais comportamentais de cio como a micção frequente, inchamento da vulva, uma montando a outra e deixando-se montar etc., pois para que esse comportamento se manifeste, o sistema nervoso necessita de uma pré-sensibilização com progesterona que não estará presente até o próximo ciclo, após o desenvolvimento do corpo lúteo vindo desta primeira ovulação. -/- -/- Sociossexual -/- A interação de indivíduos da mesma espécie ou a presença ou ausência de sinais de bioestimulação, como feromônios, pode afetar o período de puberdade. A puberdade, por exemplo, é atrasada em porcas criadas individualmente em comparação com porcas criadas em grupo. Além disso, na porca, ovelha e cabra, a exposição ao macho estimula as fêmeas e a puberdade aparece mais precocemente. -/- -/- Manejo -/- Certas práticas de manejo podem acelerar a puberdade, especialmente no período pré-púbere. Em porcas próximas à puberdade, por exemplo, o estresse causado por procedimentos, como o transporte de um local para outro ou a exposição ao macho, faz com que apareça o estro em torno de sete dias após a realização do manejo mencionado. -/- -/- • _____ESTACIONALIDADE REPRODUTIVA -/- A estacionalidade ou sazonalidade reprodutiva é uma estratégia evolutiva que se desenvolveu em algumas espécies; tende a tornar a reprodução mais eficiente. Nos países de latitudes distantes do equador, o objetivo é que as crias nasçam na primavera, época do ano mais favorável, graças à abundância de alimentos e às amenas condições climáticas. No caso da ovelha, cuja gestação dura cinco meses, para que os partos ocorram na primavera, ela deve engravidar no outono (figura 1), quando os dias são curtos; enquanto a égua, tendo uma gestação de aproximadamente 11 meses, deve conceber na primavera, quando os dias são longos; assim, o parto ocorrerá na primavera do ano seguinte (figura 2). -/- -/- Figura 1: Esquema ilustrativo da estacionalidade reprodutiva na espécie ovina. Fonte: PIRES et al., 2011. -/- -/- Esta característica evolutiva desenvolvida pela seleção natural na maioria das espécies silvestres e ainda é conservado por algumas espécies domésticas, como ovelhas, cabras, cavalos e gatos. Em bovinos e suínos, ao contrário, a domesticação levou à perda quase total da estacionalidade reprodutiva. -/- A estacionalidade reprodutiva é codificada nos genes; significa então que a seleção natural favoreceu a propagação de genes que permitiam acoplar a hora do nascimento com a melhor época do ano, por isso passou a ser considerada um método anticoncepcional natural. -/- -/- Figura 2: ciclo reprodutivo anual em espécies estacionais; onde são apresentados os períodos de gestação e a forma como se agrupam os nascimentos, independentemente da época reprodutiva da espécie, em vermelho as fêmeas estão apresentando estro ou cio. Fonte: VALENCIA, 2018. -/- -/- Fotoperíodo -/- Para sincronizar o período fértil com a época mais favorável do ano, a maioria das espécies sazonais usa o fotoperíodo (quantidade de luz diária ao longo do ano). -/- Este sinal ambiental é seguro, confiável e se repete a cada ano. Ovinos e caprinos se reproduzem na época do ano em que os dias são curtos e os equinos quando são longos. O grau de sazonalidade depende da origem da raça. As raças nativas de países localizados em latitudes elevadas (> 50°,ovelhas: soay, blackface, suffolk; cabras: saanen, alpino francês, toggenburg; equinos: puro-sangue, hanoveriano) terão uma estacionalidade mais acentuada do que as latitudes menores ou mediterrâneas (ovelhas: merino; cabras: murciana granadina; equinos: quarto de milha). Também existem raças de latitudes próximas ao Equador cuja estacionalidade é baixa ou nula (ovelhas: raças de pelo, crioulas; cabras: raças africanas e asiáticas) (tabela 2). -/- Para a maioria das raças de ovinos e caprinos, a estação reprodutiva começa no final do verão e início do outono; caracteriza-se pela apresentação de ciclos estrais sucessivos, e termina no final do inverno, quando se inicia o anestro, que se caracteriza pela ausência de ovulação. Nos equinos, ocorre o contrário, uma vez que a estação reprodutiva ocorre na primavera e no verão. -/- -/- Tabela 2: Relação entre a origem da raça e o grau de estacionalidade ou sazonalidade -/- Espécie -/- Alta -/- Média -/- Baixa -/- Ovinos -/- Suffolk, raças britânicas de lã e corte -/- Merino -/- Pelibuey, crioulas -/- Caprinos -/- Saanen, alpino, toggenburg -/- Murciana granadina -/- Crioula -/- Equinos -/- Puro-sangue, hanoveriano, quarto de milha -/- - -/- Crioula, burros -/- Fonte: VALENCIA, 2018. -/- -/- Mecanismo neuroendócrino da estacionalidade -/- Durante o período de anestro, o fotoperíodo exerce efeito inibitório sobre o centro tônico do GnRH no hipotálamo, diminuindo a frequência de pulso. Consequentemente, a pulsatilidade do LH também diminui, que agora é incapaz de induzir a maturação folicular, o aumento dos estrogênios, o pico pré-ovulatório de LH e, portanto, a ovulação. -/- Isso ocorre porque durante o anestro a sensibilidade do hipotálamo ao mecanismo de feedback negativo dos estrogênios e de outros fatores de origem não gonodal é aumentada. Ao aproximar-se da estação reprodutiva, a sensibilidade hipotalâmica diminui e o aumento da pulsatilidade do GnRH causa as mudanças que culminam na ovulação. Portanto, o mecanismo endócrino do anestro estacional é semelhante ao do anestro pré-púbere e de alguns outros tipos de anestro. -/- A estacionalidade é um bom exemplo da interação entre o meio ambiente e o sistema neuroendócrino, pois o organismo é capaz de traduzir um sinal externo ambiental, como o fotoperíodo, em um sinal hormonal interno, que neste caso é a melatonina. -/- A glândula pineal secreta melatonina durante as horas de escuridão. Os animais sazonais apresentam um ritmo reprodutivo endógeno, que é regulado por janelas de fotossensibilidade, determinadas por mudanças na duração do dia. O sinal luminoso é captado pela retina e conduzido, via nervo, pelo trato retino-hipotalâmico até o núcleo supraquiasmático, que funciona como o relógio biológico do corpo. Daí o sinal viaja para o núcleo para-ventricular, depois para o gânglio cervical e, finalmente, para a glândula pineal, que responde secretando melatonina (figura 3). -/- Nas ovelhas, a estação reprodutiva começa quando a duração do dia diminui e, naturalmente, a noite aumenta; na égua, ocorre quando os dias se alongam. -/- A primavera não é necessariamente a melhor época do ano em todas as regiões do globo. Nas latitudes tropicais, a primavera coincide com a seca e não com a abundância de forragem, aspecto a ser levado em consideração ao programar a reprodução. -/- Outro ponto importante a considerar é que as raças europeias sazonais mantêm sua estacionalidade no Brasil. -/- -/- Figura 3: Mecanismo do fotoperíodo em ovinos e a melatonina. Fonte: HAFEZ, 2004. -/- -/- Estacionalidade no macho -/- O macho é menos afetado que a fêmea pelas mudanças típicas de cada época do ano, já que sua função reprodutiva não é necessariamente interrompida durante o anestro ou repouso sexual, embora a produção de hormônios reprodutivos, tamanho e tônus testicular, a libido, as características qualitativas e quantitativas do ejaculado e a fertilidade do esperma podem ser diminuídas. O nível de afetação depende do grau de sazonalidade da raça e da latitude. Por fim, os efeitos do fotoperíodo devem ser separados dos nutricionais, que também variam com a época do ano. -/- -/- REFERÊNCIAS BIBLIOGRÁFICAS -/- -/- BEARDEN, Henry Joe et al. Reproducción animal aplicada. México: Manual Moderno, 1982. -/- BROOKS, P. H.; COLE, D. J. A. The effect of the presence of a boar on the attainment of puberty in gilts. Reproduction, v. 23, n. 3, p. 435-440, 1970. -/- CARDOSO, Daniel; DE PAULA NOGUEIRA, Guilherme. Mecanismos neuroendócrinos envolvidos na puberdade de novilhas. Arquivos de Ciências Veterinárias e Zoologia da Unipar, v. 10, n. 1, 2007. -/- CHEMINEAU, P. et al. Induction and persistence of pituitary and ovarian activity in the out-of-season lactating dairy goat after a treatment combining a skeleton photoperiod, melatonin and the male effect. Reproduction, v. 78, n. 2, p. 497-504, 1986. -/- CLARKE, Iain J. et al. Kisspeptin and seasonality in sheep. Peptides, v. 30, n. 1, p. 154-163, 2009. -/- CORTEEL, J. M. Production, storage and insemination of goat semen. In: Management and Reproduction in Sheep and Goats Symposium, Madison, Wis. (USA), 1977. University of Wisconsin, 1977. -/- CUNNINGHAM, James. Tratado de fisiologia veterinária. Elsevier Health Sciences, 2011. -/- CUPPS, Perry T. (Ed.). Reproduction in domestic animals. Elsevier, 1991. -/- DUKES, Henry Hugh; SWENSON, Melvin J.; REECE, William O. Dukes fisiologia dos animais domésticos. Editora Guanabara Koogan, 1996. -/- DÝRMUNDSSON, Ó. R.; LEES, J. L. Effect of rams on the onset of breeding activity in Clun Forest ewe lambs. The Journal of Agricultural Science, v. 79, n. 2, p. 269-271, 1972. -/- EBLING, F. J. P.; FOSTER, D. L. Photoperiod requirements for puberty differ from those for the onset of the adult breeding season in female sheep. Reproduction, v. 84, n. 1, p. 283-293, 1988. -/- FIELDS, Michael J.; SAND, Robert S.; YELICH, Joel V. (Ed.). Factors affecting calf crop: Biotechnology of reproduction. CRC Press, 2001. -/- HAFEZ, Elsayed Saad Eldin; HAFEZ, Bahaa. Reprodução animal. São Paulo: Manole, 2004. -/- HUGHES, P. E.; PHILIP, G.; SISWADI, R. The effects of contact frequency and transport on the efficacy of the boar effect. Animal Reproduction Science, v. 46, n. 1-2, p. 159-165, 1997. -/- KARSCH, FRED J. et al. Neuroendocrine basis of seasonal reproduction. In: Proceedings of the 1983 Laurentian Hormone Conference. Academic Press, 1984. p. 185-232. -/- LINCOLN, G. A.; SHORT, R. V. Seasonal breeding: nature's contraceptive. In: Proceedings of the 1979 Laurentian Hormone Conference. Academic Press, 1980. p. 1-52. -/- MELLO, Raquel Rodrigues Costa. Puberdade e maturidade sexual em touros bovinos. Agropecuária Científica no Semiárido, v. 10, n. 3, p. 11-28, 2015. -/- MEZA‐HERRERA, C. A. et al. Neuroendocrine, metabolic and genomic cues signalling the onset of puberty in females. Reproduction in Domestic Animals, v. 45, n. 6, p. e495-e502, 2010. -/- MONTEIRO, Claudia Dias; BICUDO, Sony Dimas; TOMA, Hugo Shisei. Puberdade em fêmeas ovinas. Pubvet, v. 4, p. Art. 850-857, 2010. -/- OLIVEIRA, Daniel de Jesus Cardoso de. Mecanismos neuroendócrinos envolvidos na puberdade de novilhas da raça Nelore. 2006. Tese de Doutorado em Medicina Veterinária. Universidade de São Paulo. -/- OLSTER, DEBORAH H.; FOSTER, DOUGLAS L. Control of gonadotropin secretion in the male during puberty: a decrease in response to steroid inhibitory feedback in the absence of an increase in steroid-independent drive in the sheep. Endocrinology, v. 118, n. 6, p. 2225-2234, 1986. -/- PIRES, Bruno Carlos et al. Métodos para elevar o ritmo reprodutivo dos ovinos. PUBVET, Londrina, V. 5, N. 11, Ed. 158, Art. 1071, 2011. -/- PLANT, Tony M.; ZELEZNIK, Anthony J. (Ed.). Knobil and Neill's physiology of reproduction. New York: Academic Press, 2014. -/- RAMIREZ, Domingo V.; MCCANN, S. M. Comparison of the regulation of luteinizing hormone (LH) secretion in immature and adult rats. Endocrinology, v. 72, n. 3, p. 452-464, 1963. -/- ROSER, JANET F.; HUGHES, JOHN P. Seasonal effects on seminal quality, plasma hormone concentrations, and GnRH‐induced LH response in fertile and subfertile stallions. Journal of andrology, v. 13, n. 3, p. 214-223, 1992. -/- SALOMONI, Eduardo et al. Idade e peso à puberdade em fêmeas de corte puras e cruzas em campo natural. Pesquisa Agropecuária Brasileira, v. 23, n. 10, p. 1171-1179, 1988. -/- SMITH, Jeremy T.; CLARKE, Iain J. Seasonal breeding as a neuroendocrine model for puberty in sheep. Molecular and cellular endocrinology, v. 324, n. 1-2, p. 102-109, 2010. -/- VALENCIA, J. Pubertad y estacionalidad reproductiva. In. PORTA, L. R.; MEDRANO, J. H. H. Fisiología reproductiva de los animales domésticos. Cidade do México: FMVZ-UNAM, 2018. -/- WHITTEMORE, Colin et al. The science and practice of pig production. Blackwell Science Ltd, 1998. -/- -/- -/- FIXAÇÃO DO ASSUNTO -/- -/- 1. Defina o que é puberdade e como ela manifesta-se no corpo. -/- -/- -/- 2. Diferencie puberdade de maturidade sexual. -/- -/- -/- 3. Quais são os fenômenos que devem ser observados em fêmeas que estão entrando na puberdade? -/- -/- -/- 4. Qual o papel do GnRH e do IGF-I sobre a puberdade? -/- 5. Um produtor possui duas ovelhas e um carneiro reprodutor, as ovelhas possuem idade e peso, mas não manifestaram seu primeiro cio, quais elementos que você recomenda ao produtor para induzir a ciclicidade dessas fêmeas? -/- -/- -/- 6. De forma geral, quais os fatores que podem afetar a entrada na puberdade dos animais? -/- -/- -/- 7. Defina estacionalidade reprodutiva. -/- -/- -/- 8. O que é fotoperíodo e qual sua importância para a reprodução dos animais domésticos? -/- -/- -/- 9. Defina as relações existentes entre a origem da raça e o grau de estacionalidade e como tais teorias se aplicam ao rebanho brasileiro. -/- -/- -/- 10. Qual o papel da glândula pineal para a estacionalidade reprodutiva? -/- -/- -/- 11. Por que os machos são menos afetados pela sazonalidade reprodutiva do que as fêmeas? -/- -/- -/- 12. Sabendo-se sobre os termos de puberdade e estacionalidade e as características de ambos nas espécies domésticas, pede-se: um criador deseja obter 5 novas crias ovinas e 5 caprinas em seu plantel até o final do ano, para tanto ele ainda possui um ano e está na estação do verão, sabendo-se sobre a estacionalidade dessas espécies elabore um projeto reprodutivo de modo que essas 10 fêmeas possam gerar uma cria cada até a primavera. -/- -/- Dados: 10 fêmeas gerando 10 crias. 1 macho ovino e 1 caprino. Fêmeas com 1 ano de idade (2º cio) e peso corporal = 55% do peso adulto. Verão de 2020 para parir na primavera de 2020. (shrink)

A current advance within the agricultural industry is the use of genetic engineering to produce novel crops for food production. This technology raises questions about how societies should position themselves with respect to genetically modified (GM) crop development and implementation; namely, how should the potentials and risks of this technology be evaluated? We argue that current methods to evaluate the risks and benefits of GM crops are inadequate and not conducive to the strategic development of this technology, where a way (...) to ameliorate technology assessments for GM crops is to include farmers in the research process of evaluating these crops prior to their commercialization. However, particularities concerning the ethical status of such research require special consideration and vigilance. For example, in such technology assessment initiatives, farmers would occupy both the roles of research participant and research investigator. Other particularities surface due to factors related to the nature of GM crops. These particularities are examined with reference to concepts drawn from the field of research ethics, namely informed consent, compensatory decisions, and issues of participant inclusion/exclusion. (shrink)

There is a widely acknowledged shortage of and an increasing demand for transplantable human organs and tissues (e.g., kidney, heart, lung, liver, cornea) in developed and developing countries around the world. In response to this need, Lott and Savulescu (2007) propose the creation of a human embryonic stem (hESC) bank to facilitate the equitable and efficient dissemination of human leukocyte anti- gen (HLA) matched tissues and organs to patients in need of replacement. Although not an unreasonable proposal, the authors go (...) on to make a much stronger claim. They argue that hESCs are such important tools for addressing the massive unmet global need for organs that it is ethically justified to require mandatory banking of spare embryos, and they argue for the use of financial (or other) inducements to procure embryos for the derivation of hESCs. (shrink)

While every health care system stakeholder would seem to be concerned with obtaining the greatest value from a given technology, there is often a disconnect in the perception of value between a technology’s promoters and those responsible for the ultimate decision as to whether or not to pay for it. Adopting an empirical ethics approach, this paper examines how five Canadian medical device manufacturers, via their websites, frame the corporate “value proposition” of their innovation and seek to respond to what (...) they consider the key expectations of their customers. Our analysis shows that the manufacturers’ framing strategies combine claims that relate to valuable socio-technical goals and features such as prevention, efficiency, sense of security, real-time feedback, ease of use and flexibility, all elements that likely resonate with a large spectrum of health care system stakeholders. The websites do not describe, however, how the innovations may impact health care delivery and tend to obfuscate the decisional trade-offs these innovations represent from a health care system perspective. Such framing strategies, we argue, tend to bolster physicians’ and patients’ expectations and provide a large set of stakeholders with powerful rhetorical tools that may influence the health policy arena. Because these strategies are difficult to counter given the paucity of evidence and its limited use in policymaking, establishing sound collective health care priorities will require solid critiques of how certain kinds of medical devices may provide a better (i.e., more valuable) response to health care needs when compared to others. (shrink)

We take up the challenge of developing an international network with capacity to survey the world's scientists on an ongoing basis, providing rich datasets regarding the opinions of scientists and scientific sub-communities, both at a time and also over time. The novel methodology employed sees local coordinators, at each institution in the network, sending survey invitation emails internally to scientists at their home institution. The emails link to a ‘10 second survey’, where the participant is presented with a single statement (...) to consider, and a standard five point Likert scale. In June 2023, a group of 30 philosophers and social scientists invited 20,085 scientists across 30 institutions in 12 countries to participate, gathering 6,807 responses to the statement 'Science has put it beyond reasonable doubt that COVID-19 is caused by a virus'. The study demonstrates that it is possible to establish a global network to quickly ascertain scientific opinion on a large international scale, with high response rate, low opt-out rate, and in a way that allows for significant (perhaps indefinite) repeatability. Measuring scientific opinion in this new way would be a valuable complement to currently available approaches, potentially informing policy decisions and public understanding across diverse fields. (shrink)

Gerald Gaus argued in his 1996 book Justificatory Liberalism that proponents of public reason liberalism should attempt to ground their position in a specific epistemology. Critics of public reason liberalism such as David Enoch have also argued that public reason liberals need to elucidate their epistemic claims. Surprisingly, few public reason liberals have taken up Gaus and Enoch on their challenge. This paper will interact with the epistemological position undergirding the public justification principle, access internalism, arguing that it fails. In (...) its place, I put forward and defend proper functionalism as the better grounding epistemology, and then defend the new theory from possible objections. The result will be a synthesis of Nicholas Wolterstorff’s version of liberalism and an externalist version of convergence public reason liberalism. (shrink)

Concern about the ethics of clinical drug trials research on patients and healthy volunteers has been the subject of significant ethical analysis and policy development—protocols are reviewed by Research Ethics Committees and subjects are protected by informed consent procedures. More recently attention has begun to be focused on DNA banking for clinical and pharmacogenetics research. It is, however, surprising how little attention has been paid to the commercial nature of such research, or the unique issues that present when subjects are (...) asked to consent to the storage of biological samples. Our contention is that in the context of pharmacogenetic add-on studies to clinical drug trials, the doctrine of informed consent fails to cover the broader range of social and ethical issues. Applying a sociological perspective, we foreground issues of patient/subject participation or ‘work’, the ambiguity of research subject altruism, and the divided loyalties facing many physicians conducting clinical research. By demonstrating the complexity of patient and physician involvement in clinical drug trials, we argue for more comprehensive ethical review and oversight that moves beyond reliance on informed consent to incorporate understandings of the social, political and cultural elements that underpin the diversity of ethical issues arising in the research context. (shrink)

Truth is undefined for imperative statements. However, if imperatives implicitly reference a fact, they can be rephrased as truth­-valuable declaratives explicitly referencing that fact. But are there such facts? Kenny held that any imperative references a set of wishes held by its imperator. I extend his thesis by proposing that imperator wishes are facts implicitly referenced by imperatives and explicitly referencing them yields semantically isomorphic declaratives. I implement this thesis with modal operators for wants and cause with which declarative schemata (...) are formed to automate translation of imperatives into semantically isomorphic declaratives called proxy-­imperatives. The proxy-­imperatives match imperative behavior and provide semantic validation of imperative arguments thereby integrating imperative reasoning into classic truth­-valuable logic. (shrink)

Observers inspected normal, high quality color displays of everyday visual scenes while their eye movements were recorded. A large display change occurred each time an eye blink occurred. Display changes could either involve "Central Interest" or "Marginal Interest" locations, as determined from descriptions obtained from independent judges in a prior pilot experiment. Visual salience, as determined by luminance, color, and position of the Central and Marginal interest changes were equalized. -/- The results obtained were very similar to those obtained in (...) prior experiments showing failure to detect changes occurring simultaneously with saccades, flicker, or “mudsplashes” in the visual scene: Many changes were very hard to detect, and Marginal Interest changes were harder to detect than Central Interest changes. -/- Analysis of eye movements showed, as expected, that the probability of detecting a change depended on the eye’s distance from the change location. However a surprising finding was that both for Central and Marginal Interest changes, evenwhen observers were directly fixating the change locations (within 1 degree),more than 40% of the time they still failed to see the changes. It seems that looking at something does not guarantee you “ see” it. (shrink)

Jusqu’à présent, les discussions au sein de la communauté universitaire et dans la littérature scientifique sur la conduite responsable en recherche (CRR), incluant l’intégrité scientifique et l’éthique de la recherche, ont principalement été menées par les chercheurs en sciences de la santé et en sciences fondamentales. Préoccupés, à juste titre, par des problèmes d’inconduite, leurs effets négatifs sur la rigueur scientifique et la confiance du public dans l’entreprise de la recherche, ces débats ont conduit à l’élaboration et à la mise (...) en œuvre de lignes directrices nationales et de politiques institutionnelles. Ces lignes directrices visent entre autres à promouvoir la CRR, notamment dans le but de prévenir ces inconduites. Cependant, pour garantir la pertinence et une application appropriée de ces normes à tous les domaines universitaires, il est nécessaire que les sciences humaines et sociales (SHS) contribuent plus directement à ces discussions. Un tel engagement devrait permettre d’exprimer les particularités disciplinaires et méthodologiques des SHS, dont certaines peuvent être très différentes des sciences appliquées et fondamentales. Cela permettrait également de s’assurer que la littérature sur la CRR ainsi que les politiques et les directives qui en découlent soient à la fois fondées sur des principes universellement généralisables, mais aussi appliquées avec nuance afin de refléter la diversité des pratiques disciplinaires. Dans ce chapitre, nous explorons trois grands domaines dans lesquels les SHS pourraient contribuer à façonner les discussions dans la littérature sur la CRR, tout en informant les chercheurs en SHS des meilleures pratiques en matière de CRR : l’autorat/paternité, la collaboration et l’autorégulation. (shrink)

We argue that, in order to explain the relative strengths of our reasons to contribute to different collective endeavours, approaches to the ethics of collective action must understand the strengths of our reasons to make a given contribution as proportional to its expected benefits, or its chances of bringing about benefits in proportion to their magnitudes. The view that most clearly meets this proportionality requirement is the expected consequences approach, which identifies our reasons to perform an act with its expected (...) benefits. We contend that views other than the expected consequences approach must similarly proportion the expected degrees of what they take to be reason-giving features of a contribution – such as its virtuousness, appropriate expression, support by considerations of fairness, or helping without making a difference – to the contribution’s expected benefits. The proportionality requirement explains why we should spend more time participating in strategic social, political, and labour movement activities, while avoiding unproductive conflicts and merely performative activities. We conclude that the proportionality requirement, and the ability of views other than the expected consequences approach to meet it, are important for thinking and communicating about the ethics of collective action in ways that are simultaneously most compelling and most strategic. (shrink)

Objective Our study sought to (1) describe the practices and preferences of Colombian adolescents in accessing sexual and reproductive health services: accompanied versus alone; (2) compare actual practices with stated preferences; and (3) determine age and gender differences regarding the practice and these stated preferences. -/- Methods 812 participants aged 11–24 years old answered a survey in two Profamilia clinics in the cities of Medellin and Cali in Colombia. A cross-sectional analysis was performed to compare participants’ answers based on the (...) variables of gender and age. -/- Results A quarter of participants visited the clinic alone (25.4%). Females were more likely to go alone in comparison to males (26.3% vs 14.1%; p = 0.031), and older participants went alone more often than younger participants (p < 0.001). Most participants – 72.7% (95 %CI: 69.3–75.9) – expressed a preference in being accompanied to the clinic, and more than 90% had their preferences met. The preferences of older participants were, however, less likely to be met than those of younger participants (p < 0.001), notably, because they predominantly wanted to be accompanied. -/- Conclusion Contemporary public health and bioethics literature advocates in favor of developing health services that better meet the preferences of adolescents. The present research highlights an apparent blind spot related to the role that others (e.g., parents, friends, partners) can or should play in accompanying adolescent patients when they access sexual and reproductive health services. Respecting adolescents’ preferences, and hence their autonomy, is not simply a matter of ensuring freedom from constraints (e.g., their right and ability to go alone). Rather, it should also consider the liberty to choose whether to be accompanied when accessing SHRS and by whom. (shrink)

Throughout the biological and biomedical sciences there is a growing need for, prescriptive ‘minimum information’ (MI) checklists specifying the key information to include when reporting experimental results are beginning to find favor with experimentalists, analysts, publishers and funders alike. Such checklists aim to ensure that methods, data, analyses and results are described to a level sufficient to support the unambiguous interpretation, sophisticated search, reanalysis and experimental corroboration and reuse of data sets, facilitating the extraction of maximum value from data sets (...) them. However, such ‘minimum information’ MI checklists are usually developed independently by groups working within representatives of particular biologically- or technologically-delineated domains. Consequently, an overview of the full range of checklists can be difficult to establish without intensive searching, and even tracking thetheir individual evolution of single checklists may be a non-trivial exercise. Checklists are also inevitably partially redundant when measured one against another, and where they overlap is far from straightforward. Furthermore, conflicts in scope and arbitrary decisions on wording and sub-structuring make integration difficult. This presents inhibit their use in combination. Overall, these issues present significant difficulties for the users of checklists, especially those in areas such as systems biology, who routinely combine information from multiple biological domains and technology platforms. To address all of the above, we present MIBBI (Minimum Information for Biological and Biomedical Investigations); a web-based communal resource for such checklists, designed to act as a ‘one-stop shop’ for those exploring the range of extant checklist projects, and to foster collaborative, integrative development and ultimately promote gradual integration of checklists. (shrink)

Depuis 2020, le monde a connu une situation sanitaire exceptionnelle à la suite de la pandémie de Covid-19, faisant face à une incertitude dans le monde médical clinique, de la recherche et dans l’ensemble des domaines connexes en santé publique. Le caractère imprévisible et l’absence de données fiables en lien avec ce virus ont fait émerger une quantité d’enjeux éthiques concrets, cela a donc révélé un domaine particulier, la bioéthique, et plus particulièrement une profession, les bioéthiciens. Les « bioéthiciens » (...) se sont fait connaître du grand public en se dressant parfois comme des garde-fous contre des dérives sanitaires, à d’autres moments comme des lanceurs d’alertes face à des injustices naissantes, ou comme critiques, polémistes et parfois même militants dans les médias ou en tant qu’acteurs de première ligne dans les systèmes politico-sanitaires. Ces divers rôles et pratiques illustrent bien la diversité et l’hétérogénéité du domaine de la bioéthique. Toutefois, l’absence de professionnalisation traditionnelle et formelle de la bioéthique complexifie la compréhension de ce champ disciplinaire. Même en Amérique du Nord, où la pratique de la bioéthique est professionnalisée, il ne s’agit toujours pas d’une profession officiellement reconnue et le terme « bioéthicien » lui-même peut être controversé. La forte présence de cette profession durant la pandémie de Covid-19 a révélé l’importance de décrire ce qu’est un bioéthicien, les fonctions qu’il occupe et en quoi consistent ses interventions. Nous apportons cette clarification nécessaire en expliquant la nature de la bioéthique contemporaine dans toute sa diversité. Comme nous l’a démontré la pandémie de Covid-19, les bioéthiciens représentant un soutien et un guide indispensable de nos jours menés par leur esprit critique et leur réflexivité permanente. (shrink)

"Nothing Better Than Death" is a comprehensive analysis of the near-death experiences profiled on the www.near-death.com website. This book provides complete NDE testimonials, summaries of various NDEs, NDE research conclusions, a Question and Answer section, an analysis of NDEs and Christian doctrines, famous quotations about life and death, a NDE bibliography, book notes, a list of NDE resources on the Internet, and a list of NDE support groups associated with IANDS.org - the International Association for Near-Death Studies. The unusual title (...) of this book, "Nothing Better Than Death," was inspired by NDE experiencer Dr. Dianne Morrissey who once said, "If I lived a billion years more, in my body or yours, there's not a single experience on Earth that could ever be as good as being dead. Nothing.". (shrink)

This paper develops a notion of manipulative gaslighting, which is designed to capture something not captured by epistemic gaslighting, namely the intent to undermine women by denying their testimony about harms done to them by men. Manipulative gaslighting, I propose, consists in getting someone to doubt her testimony by challenging its credibility using two tactics: “sidestepping” and “displacing”. I explain how manipulative gaslighting is distinct from reasonable disagreement, with which it is sometimes confused. I also argue for three further claims: (...) that manipulative gaslighting is a method of enacting misogyny, that it is often a collective phenomenon, and, as collective, qualifies as a mode of psychological oppression. (shrink)

CLE aims and clients’ needs conflict where students’ interests are put beyond clients’ needs. Students have interests in gaining employment, impressing instructors and supervisors, and experiencing the active application of law. Where the clients’ service-needs are subordinated to students’ interests, the relationship between the two—the ‘tension’—is tilted in a manner in which the clients are disserved through the fulfilment of students’ interests. This may be exacerbated by faulty institutional cultures where clinical faculty are treated differently, or as less accomplished or (...) ‘worthwhile’ than their ‘traditional’ counterparts. This also emphasizes that it is the clinical law faculty who may exacerbate or assuage the tension, as it is for clinical faculty to assure that clients’ needs are met on ethical grounds,20 and to equate the practice of law with excellence before students. (shrink)

BioéthiqueOnline was launched in March 2012 as a non-peer reviewed journal with the aim of providing a platform to facilitate and encourage the development of a bilingual bioethics community in Canada and internationally. In light of discussions amongst the Editorial Committee over the past few months regarding the growth of the journal, we have decided to move to a peer-reviewed process for articles submitted to the journal.

Discussions concerning whether there is a natural right to health care may occur in various forms, resulting in policy recommendations for how to implement any such right in a given society. But health care policies may be judged by international standards including the UN Universal Declaration of Human Rights. The rights enumerated in the UDHR are grounded in traditions of moral theory, a philosophical analysis of which is necessary in order to adjudicate the value of specific policies designed to enshrine (...) rights such as a right to health care. We begin with an overview of the drafting of the UDHR and highlight the primary influence of natural law theory in validating the rights contained therein. We then provide an explication of natural law theory by reference to the writings of Thomas Aquinas, as well as elucidate the complementary “capabilities approach” of Martha Nussbaum. We conclude that a right to health care ought to be guaranteed by the state. (shrink)

The comprehension of anaphoric relations may be guided not only by discourse, but also syntactic information. In the literature on online processing, however, the focus has been on audible pronouns and descriptions whose reference is resolved mainly on the former. This paper examines one relation that both lacks overt exponence, and relies almost exclusively on syntax for its resolution: adjunct control, or the dependency between the null subject of a non-finite adjunct and its antecedent in sentences such as Mickey talked (...) to Minnie before ___ eating. Using visual world eyetracking, we compare the time course of interpreting this null subject and overt pronouns (Mickey talked to Minnie before he ate). We show that when control structures are highly frequent, listeners are just as quick to resolve reference in either case. When control structures are less frequent, reference resolution based on structural information still occurs upon hearing the non-finite verb, but more slowly, especially when unaided by structural and referential predictions. This may be due to increased difficulty in recognizing that a referential dependency is necessary. These results indicate that in at least some contexts, referential expressions whose resolution depends on very different sources of information can be resolved approximately equally rapidly, and that the speed of interpretation is largely independent of whether or not the dependency is cued by an overt referring expression. (shrink)

Bioethics experts played a key role in ensuring a coherent ethical response to the COVID-19 pandemic in the fields of healthcare, public health, and scientific research in Canada. In the province of Quebec, a group of academic and practicing bioethicists met periodically in the early months of the pandemic to discuss approaches and solutions to ethical dilemmas encountered during the crisis. These meetings created the opportunity for a national survey of bioethics practitioners from different fields. The survey, in which forty-five (...) Canadian bioethics practitioners (clinical ethicists, ethicist members of REBs and government health policy ethicists, or any bioethicist practicing outside of academia) participated, explored their concerns, challenges and opportunities during the first wave of the pandemic, with the objective of informing bioethics research about the difficulties experienced by bioethicists “in the field”. Participants reported increased stress levels, increased workloads, and a greater proportion of their work being devoted to public health ethics. Most of their concerns focused on groups other than themselves, such as health professionals, patients, research participants, and people in vulnerable socio-economic situations. An optimism about the future of bioethics was noted due to an increased awareness of the importance of bioethics by the public and by health and research institutions. (shrink)

This article identifies and compares meanings of wildfire risk mitigation for stakeholders in the Front Range of Colorado, USA. We examine the case of a collaborative partnership sponsored by government agencies and directed to decrease hazardous fuels in interface areas. Data were collected by way of key informant interviews and focus groups. The analysis is guided by the Circuit of Culture model in communication research. We found both shared and differing meanings between members of this partnership (the ‘‘producers’’) and other (...) stakeholders not formally in the partnership (the ‘‘consumers’’). We conclude that those promoting the partnership’s project to mitigate risk are primarily aligned with a discourse of scientific management. Stakeholders outside the partnership follow a discourse of community. We argue that failure to recognize and account for differences in the way risk mitigation is framed and related power dynamics could hamper the communicational efforts of the collaborative partnership and impact goals for fuels reduction. We recommend ways that both groups can capitalize on shared meanings and how agency managers and decision makers can build better working relationships with interface communities and other external stakeholders. (shrink)

Ebola is a deadly disease with no cure; there is no vaccine developed yet. Many died during the 2014 outbreak in West Africa, and many healthcare professionals went to the virus infected area to treat the patients while placing their lives in danger. Not every medical professional placed in the field is a fully trained specialist, and sometimes one or two under-trained doctors are in charge of the entire clinic with some nurses and operating technicians. When unexpected outbreaks of the (...) virus occur in the places, the doctor(s) would encounter medical and ethical dilemmas. Should they leave or stay? In fact, this dilemma is not confined to the Ebola pandemic but relevant to all similar cases. In this paper, three authors, a medical resident, a clinical bioethicist, and a theoretical bioethicist respond to the dilemma. (shrink)