Proponents of the rule of law argue about whether that ideal should be conceived formalistically or in terms of substantive values. Formalistically, the rule of law is associated with principles like generality, clarity, prospectivity, consistency, etc. Substantively, it is associated with market values, with constitutional rights, and with freedom and human dignity. In this paper, I argue for a third layer of complexity: the procedural aspect of the rule of law; the aspects of rule-of-law requirements that have to do with (...) "natural Justice" or "procedural due process." These I believe have been neglected in the jurisprudential literature devoted specifically to the idea of the rule of law and they deserve much greater emphasis. Moreover procedural values go beyond elementary principles like the guarantee of an unbiased tribunal or the opportunity to present and confront evidence. They include the right to argue in a court about what the law is and what its bearing should be on one's situation. The provision that law makes for argument is necessarily unsettling, and so this emphasis on the procedural aspect highlights the point predictability should not be regarded as the be-all and end-all of the rule of law. (shrink)

In this paper it is argued that the conjunction of linguistic ersatzism, the ontologically deflationary view that possible worlds are maximal and consistent sets of sentences, and possible world semantics, the view that the meaning of a sentence is the set of possible worlds at which it is true, implies that no actual speaker can effectively use virtually any language to successfully communicate information. This result is based on complexity issues that relate to our finite computational ability to deal with (...) large bodies of information and a strong, but well motivated, assumption about the cognitive accessibility of meanings of sentences ersatzers seem to be implicitly committed to. It follows that linguistic ersatzism, possible world semantics, or both must be rejected. (shrink)

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: -/- The main aim of this review will be to assess the effects of changing practitioner empathy or patient expectations for all conditions. The main objective is to conduct a systematic review of randomised trials where the intervention involves manipulating either (a) practitioner empathy or (b) patient expectations, or (c) both.

In this paper, we provide an account of the ontological status of Christ’s dead body, which remained in the tomb during the three days after his crucifixion. Our account holds that Christ’s dead body – during the time between his death and resurrection – was prime matter without a substantial form. We defend this account by showing how it is metaphysically possible for prime matter to exist in actuality without substantial forms. Our argument turns on the truth of two theses: (...) God is able to produce all acts of secondary causes without those secondary causes, and Substantial forms are secondary causes of the actuality of prime matter. We argue that the metaphysical possibility of matter without form is perfectly consistent with holding both there is only one substantial form in a material substance and that prime matter is pure potentiality. Moreover, we argue that the metaphysical possibility of matter without form does little-to-no damage to our natural understanding of material substances. (shrink)

The development of possible worlds semantics for modal claims has led to a more general application of that theory as a complete semantics for various formal and natural languages, and this view is widely held to be an adequate (philosophical) interpretation of the model theory for such languages. We argue here that this view generates a self-referential inconsistency that indicates either the falsity or the incompleteness of PWS.

Mimesis can refer to imitation, emulation, representation, or reenactment - and it is a concept that links together many aspects of ancient Greek Culture. The Western Greek bell-krater on the cover, for example, is painted with a scene from a phlyax play with performers imitating mythical characters drawn from poetry, which also represent collective cultural beliefs and practices. One figure is shown playing a flute, the music from which might imitate nature, or represent deeper truths of the cosmos based upon (...) Pythagorean views (which were widespread in Western Greece at the time). The idea that mimesis should be restricted to ideals was made famous by Plato (whose connections to Pythagoreanism and Siracusa are well-known), and famously challenged by his student Aristotle (not to mention by the mimetic character of Plato’s own poetry). This volume gathers essays not only on the philosophical debate about mimesis, but also on its use in architecture, drama, poetry, history, music, ritual, and visual art. The emphasis is on examples from Hellenic cities in Southern Italy and Sicily, but the insights apply far beyond – even to modern times. Contributors include: Thomas Noble Howe, Francisco J. Gonzalez, Gene Fendt, Guilherme Domingues da Motta, Jeremy DeLong, Carolina Araújo, Marie-Élise Zovko, Lidia Palumbo, Sean Driscoll, Konstantinos Gkaleas, Anna Motta, Jure Zovko, Alexander H. Zistakis, Christos C. Evangeliou, Dorota Tymura, Iris Sulimani, Elliott Domagola, Jonah Radding, Giulia Corrente, Laura Tisi, Ewa Osek, Argyri G. Karanasiou, Rocío Manuela Cuadra Rubio, Jorge Tomás García, Aura Piccioni, and José Miguel Puebla Morón. (shrink)

Le présent travail s'inscrit à l'intersection de deux problèmes épistémologiques majeurs. D'une part, le problème de la démarcation scientifique, qui consiste à identifier ce qui distingue intrinsèquement un système (un énoncé, une théorie, ...) scientifique d'un système non scientifique ou pseudo-scientifique. D'autre part, le problème de l'unité épistémologique des sciences, qui consiste à se demander si toutes les disciplines à vocation scientifique peuvent être vues comme des instanciations d'une notion unique de la scientificité. Ces deux problèmes ont soulevé de nombreux (...) débats ayant mis en évidence un ensemble important de difficultés. Le terme « scientifique » désigne en effet des méthodes empiriques, des constructions théoriques et des pratiques de recherche si hétérogènes qu’il semble voué à l’échec d’en chercher une définition aisée à circonscrire. De plus, les objets des disciplines scientifiques sont eux-mêmes de natures très diverses, ce qui semble rendre pareillement caduque toute recherche d’un concept unique de science qui pourrait s’appliquer indépendamment de la discipline en question. Dans cette thèse, je me propose de prendre à contre-pied cet état de fait en soutenant la possibilité et la pertinence d'un modèle unitaire de la scientificité, tout en me restreignant à une approche épistémologique comparée entre les sciences physiques et les sciences sociales. Pour défendre mon propos, j’ai mobilisé deux types de réponses pouvant être opposées au constat présenté plus haut. D’une part, des réponses de principe, où j’examine et m’oppose à des arguments théoriques soutenant l’impossibilité ou en tout cas la difficulté de définir la scientificité en général, et la nécessité pour les sciences sociales de jouir d’une définition à part. D’autre part, je mobilise également des réponses par l’exemple. J’étudie alors plus en détail l’approche dite « analytique » en sociologie. Ce courant a cela d’intéressant pour mon propos qu’il ne semble pas nécessiter d’épistémologie alternative à celle ayant cours, par exemple, en physique ou en biologie, tout en prétendant bien produire des connaissances sur le monde social. Il s’agit donc d’un contre-exemple concret et manifeste de la thèse soutenant que la sociologie ne peut pas jouir du même type d’épistémologie que les autres disciplines. Plus concrètement, j’élabore un (méta-)modèle unitaire de la scientificité en me concentrant sur une unité d’analyse bien circonscrite : les modèles. Je distingue chez ses derniers, classiquement, deux composantes principales : une composante empirique, qui a pour vocation à identifier des régularités dans le réel auquel on a accès à travers des données, et une composante théorique, à visée explicative et classificatoire. Je propose alors de construire formellement un degré de scientificité global dans lequel se combinent la maximisation d’une certaine quantité d’information définie sur la composante empirique et un critère d’invariance structurelle défini sur la composante théorique. Ces diverses constructions, bien que formelles, permettent d’éclairer efficacement les questions épistémologiques que je me suis données au départ de mon travail, ce dernier ayant vocation à constituer une étape supplémentaire vers un modèle unitaire de la scientificité. (shrink)

Waldron argues that recent treatments of justice have neglected reasonable disagreement about justice itself. So Waldron offers a procedural account of democratic legitimacy, in which contending views of justice can be brought together to arrive at a decision without deciding which one is correct. However, if there is reasonable disagreement about everything, then this includes his preferred account of legitimacy. On the other hand, it is not clear that Waldron is right to count so much disagreement as (...) reasonable. But then Waldron has not undermined the view he opposes in which some prevailing disagreement about justice is held to be unreasonable. (shrink)

The idea that all human beings have equal moral worth has been challenged by insisting that this is utterly counter-intuitive in the case of individuals like, for instance, Hitler on the one hand and Schweitzer on the other. This seems to be confirmed by a hypothetical in which one can only save one of the two: intuitively, one clearly should save Schweitzer, not Hitler, even if Hitler does not pose a threat anymore. The most natural interpretation of this intuition appeals (...) to unequal moral worth. Jeremy Waldron has recently tried to meet this challenge by giving a different interpretation, thereby trying to explain away the counter-intuitive implications of the basic equality doctrine in this case, and by suggesting that the rejection of basic equality comes with counter-intuitive implications of its own. I shall argue that Waldron’s response to the challenge fails on both counts. (shrink)

Among the most persuasive arguments against hate speech bans was made by Ronald Dworkin, who warned of the threat to political legitimacy posed by laws that deny those subject to them adequ...

In this chapter, I will explore the intersection of philosophy and childhood through the intriguing case study of J. S. Mill, who was almost completely denied a childhood—in the nineteenth-century sense of a qualitatively distinct period inclusive of greater play, imaginative freedom, flexibility, and education. For his part, Mill’s lack of such a childhood was the direct result of his father, James Mill (economic theorist and early proponent of Utilitarianism), who in a letter to Jeremy Bentham explicitly formulates a (...) plan to raise his son as an experiment in the Utilitarian “science” of ethics. More specifically, although James Mill’s end was to create a near-superhuman champion of Utilitarianism, his means to that end included denying John access to other children and the Romantic poetry of his contemporaries. Despite this oppressive lack of a childhood, however, J. S. Mill went on to become perhaps the most influential social and political reformer in British history, especially in regard to gender relations through his groundbreaking work for women’s suffrage. This begs the central question of this chapter, namely how could a philosopher’s tyrannized childhood nevertheless lead to his later overturning of such tyranny in the political sphere? (shrink)

The purpose of this article is to consider the question of whether democratic legitimacy requires viewpoint neutrality with regard to political speech – including extremist political speech, such as hate speech. The starting point of my discussion is Jeremy Waldron’s negative answer to this question. He argues that it is permissible for liberal democracies to ban certain extremist viewpoints – such as vituperative hate speech – because such viewpoint-based restrictions protect the dignity of persons and a social and (...) moral environment of mutual respect. According to Waldron, well-drafted narrow hate speech bans are not democratically illegitimate, and they do not undermine systemic democratic legitimacy – that is, the legitimacy of a democratic political system. In contrast to Waldron, I will argue that democratic legitimacy requires viewpoint neutrality to respect persons as thinking agents. I will defend a civil libertarian doctrine of viewpoint neutrality, and this doctrine requires that citizens in liberal democracies ought to have a legal free speech right to do moral wrong – that is, a legal right to express and defend any political viewpoint or idea, even if it is morally wrong to express, or expose others to, such views. It will be argued that any viewpoint-based restriction on public discourse (including narrow hate speech bans) is democratically illegitimate, and that such restrictions undermine systemic democratic legitimacy. (shrink)

Kant limits cosmopolitan right to a universal right of hospitality, condemning European imperial practices towards indigenous peoples, while allowing a right to visit foreign countries for the purpose of offering to engage in commerce. I argue that attempts by contemporary theorists such as Jeremy Waldron to expand and update Kant’s juridical category of cosmopolitan right would blunt or erase Kant’s own anti-colonial doctrine. Waldron’s use of Kant’s category of cosmopolitan right to criticize contemporary identity politics relies on (...) premises that upset Kant’s balanced right to hospitality. An over-extensive right to visit can invoke “Kantian” principles that Kant himself could not have consistently held, without weakening his condemnation of European settlement. I construct an alternative spirit of cosmopolitan right more favorable to the contemporary claims of indigenous peoples. Kant’s analysis suggests there are circumstances when indigenous peoples may choose whether to engage in extensive cultural interaction, and reasonably refuse the risks of subjecting their claims to debate in democratic politics in a unitary public. Cosmopolitan right accorded respect to peoples; any “domestic” adaptation of cosmopolitan right should respect indigenous peoples as peoples, absent a serious public explanation by a democratic state for why it has now become appropriate to treat indigenous peoples merely as individual citizens. (shrink)

I try in this essay to accomplish two things. First I offer some first thoughts toward a clarification of the ethical foundations of private property rights that avoids pitfalls common to more strictly Lockean theories, and is thus better prepared to address arguments posed by critics of standard private property arrangements. Second, I'll address one critical argument that has become pretty common over the years. While versions of the argument can be traced back at least to Pierre Joseph Proudhon, I'll (...) focus on a formulation given it by Jeremy Waldron. The basic idea is that the only sound arguments for private property rights lead to the conclusion that society has an obligation to insure that every citizen possess private property. In Waldron's formulation, what is justifiable is a general, rather than a special, right to private property. I shall try to suggest that this conclusion is unwarranted. (shrink)

The paper makes a twofold contribution. Firstly, it advances a preliminary account of the conditions that need to obtain for constitutional rights to be democratic. Secondly, in so doing, it defends precommitment-based theories from a criticism raised by Jeremy Waldron—namely, that constitutional rights do not become any more democratic when they are democratically adopted, for the people could adopt undemocratic policies without such policies becoming democratic as a result. The paper shows that the reductio applies to political rights, (...) yet not to non-political rights, such as reproductive, environmental, or privacy rights. The democratic status of the former is process-independent. The latter, by contrast, are democratic precisely when they are adopted by democratic means. (shrink)

Jeremy Waldron argues that claims to reparation for historic injustices can be superseded by the demands of justice in the present. For example, justified Maori claims to reparation resulting from the wrongful appropriation of their land by European settlers may be superseded by the claim to a just distribution of resources possessed by the world’s existing inhabitants. However, if we distinguish between reparative and restitutive claims, we see that while claims to restitution may be superseded by changes in (...) circumstance, this does not entail that claims to reparation are. In contrast, claims to reparation are robust to changes in circumstance. (shrink)

Jeremy Waldron has recently raised the question of whether there is anything approximating the creative self-authorship of personal autonomy in the writings of Immanuel Kant. After considering the possibility that Kantian prudential reasoning might serve as a conception of personal autonomy, I argue that the elements of a more suitable conception can be found in Kant’s Tugendlehre, or “Doctrine of Virtue”—specifically, in the imperfect duties of self-perfection and the practical love of others. This discovery is important for at (...) least three reasons: first, it elucidates the relationship among the various conceptions of autonomy employed by personal-autonomy theorists and contemporary Kantians; second, it brings to the surface previously unnoticed or undernoticed features of Kant’s moral theory; and third, it provides an essential line of defense against certain critiques of contemporary Kantian theories, especially that of John Rawls. (shrink)

This paper examines Jeremy Waldron’s ‘core case’ against judicial review. Waldron’s arguments, it shows, exaggerate the importance of voting to our judgements about the legitimacy and democratic credentials of a society and its government. Moreover, Waldron is insufficiently sensitive to the ways that judicial review can provide a legitimate avenue of political activity for those seeking to rectify historic injustice. While judicial review is not necessary for democratic government, the paper concludes that Waldron is wrong (...) to believe that it is a threat to democracy. (shrink)

This paper examines two recent contributions to the hate speech literature – by Steven Heyman and Jeremy Waldron – which seek a justification for the legal restriction of hate speech in an account of the way that hate speech infringes against people’s dignity. These analyses look beyond the first-order hurts and disadvantages suffered by the immediate targets of hate speech, and consider the prospect of hate speech sustaining complex social structures whose wide-scale operations lower the social status of (...) members of targeted groups. In Heyman’s and Waldron’s accounts we find plausible insights into the nature of identity-based social hierarchies, and the harms that redound to subordinated people under the operations of such hierarchies. I argue, however, that both analyses are unsuccessful as justifications for the restriction of hate speech, because they do not ultimately provide reason to think that hate speech is responsible for creating or sustaining identity-based social hierarchies. (shrink)

In discussions of state surveillance, the values of privacy and security are often set against one another, and people often ask whether privacy is more important than national security.2 I will argue that in one sense privacy is more important than national security. Just what more important means is its own question, though, so I will be more precise. I will argue that national security rationales cannot by themselves justify some kinds of encroachments on individual privacy (including some kinds that (...) the United States has conducted). Specifically, I turn my attention to a recent, well publicized, and recently amended statute (section 215 of the USA Patriot Act3), a surveillance program based on that statute (the National Security Agency’s bulk metadata collection program), and a recent change to that statute that addresses some of the public controversy surrounding the surveillance program (the USA Freedom Act).4 That process (a statute enabling surveillance, a program abiding by that statute, a public controversy, and a change in the law) looks like a paradigm case of law working as it should; but I am not so sure. While the program was plausibly legal, I will argue that it was morally and legally unjustifiable. Specifically, I will argue that the interpretations of section 215 that supported the program violate what Jeremy Waldron calls “legal archetypes,”5 and that changes to the law illustrate one of the central features of legal archetypes and violation of legal archetypes. The paper proceeds as follows: I begin in Part 1 by setting out what I call the “basic argument” in favor of surveillance programs. This is strictly a moral argument about the conditions under which surveillance in the service of national security can be justified. In Part 2, I turn to section 215 and the bulk metadata surveillance program based on that section. I will argue that the program was plausibly legal, though based on an aggressive, envelope-pushing interpretation of the statute. I conclude Part 2 by describing the USA Freedom Act, which amends section 215 in important ways. In Part 3, I change tack. Rather than offering an argument for the conditions under which surveillance is justified (as in Part 1), I use the discussion of the legal interpretations underlying the metadata program to describe a key ambiguity in the basic argument, and to explain a distinct concern in the program. Specifically that it undermines a legal archetype. Moreover, while the USA Freedom Act does not violate legal archetypes, and hence meets a condition for justifiability, it helps illustrate why the bulk metadata program did violate archetypes. (shrink)

This collection for a course in Social Thought and the Critique of Power includes selections from Sandra Bartkey, Wendy Brown, Judith Butler, Luc Boltanski, Eve Chiapello, Juergin Habermas, Margaret Kohn, Saskia Sassen, Margit Mayer, David Ciavatta, Michael Hardt, Antonio Negri, and Jeremy Waldron. Selections include material on the city, neoliberalism, computer-mediated life, precarity, cosmopolitanism, and gender. This packet may still be available as a print-on-demand title at the Ryerson University Bookstore.

Thinking of the evils of homophobia and what is needed to survive them requires acknowledging a new category of evil besides the evils of individual deeds, social practices and social structures. That further category is evil social environments. Building on the work of Jeremy Waldron on the harm in hate speech, this chapter extends that account to certain hate crimes that, like the written word, send a lingering social message. The cases of four women survivors of homophobia are (...) then examined in relation to such harm. Two who wrote memoirs had been targeted for murder, one in an evil environment, the other in a more positively responsive environment. The remaining two survival stories are less dramatic. But they are important in how they illustrate ordinary challenges faced successfully by lesbians and gay men in emotionally toxic environments, and how, in this sense, those not directly threatened with murder might still be justly regarded as survivors. The chapter concludes with reflections on the meanings of survival and some of the costs of surviving an evil homophobic environment. (shrink)

The natural duty theory holds that "we have a natural duty to support the laws and institutions of a just state" (Jeremy Waldron). We owe this not because we ever promised to support these laws and institutions, nor because fair play requires we support the cooperative ventures from which we receive benefits. The claim is that we have a general duty to promote institutions that do something justice requires wherever these institutions may be, a duty that does not (...) depend on our having special ties to these institutions, special ties of the sort we have to the institutions of our own government. I argue that we do not need to appeal to the idea of a natural duty to justify compliance with many laws. For example, New Zealanders must not murder, rape, or steal while in France, not because they have a duty to obey laws of a just state, but because it is wrong to murder, rape, or steal. If the natural duty theory is taken to be a statement of the conditions necessary for an obligation to exist, it would wrongly conclude there is no duty to obey laws against murder or rape in a state whose institutions and laws are not just. A second class of laws reflect not moral judgments but, rather, local conventions, conventions that are morally arbitrary but which may be useful in coordinating action. For example, New Zealanders visiting France must drive on the right side of the road, as dictated by French convention. Here, too, the natural duty theory fails to provide a suitable account of the relation noncitizens have to such laws. Our reasons for driving on the right side of the road when this is accepted convention have nothing to do with the justice of the institutions of the state. To flout this convention is not to undermine justice since there is nothing just or unjust about driving on one side of the road or another. I question the advantages of the natural duty theory, especially in light of important ambiguities in the theory. (shrink)

This anthology makes it possible to follow the lines of a 20-year debate between liberal and communitarian theories. The extensive introductory essay provides the reader with a broad overview. The anthological section includes a significant selection of what this debate has produced. The choice includes essays by Michael Sandel, Alasdair MacIntyre, Charles Taylor, Charles Larmore, Kenneth Baynes, Ronald Dworkin, and Philip Selznick aimed at addressing the philosophical issues of the debate: the relationship between the good and the right and the (...) relationship between liberal society and community. A second group of essays, by Bernard Williams, Michael Sandel, Michael Moore, Jeremy Waldron, addresses the more particular issue of the relationship between morality and law, drawing inspiration from controversial judgments of American courts on abortion and homosexual practices. (shrink)

This paper considers a particular instance in which a liberal state –Germany -makes a claim for the limitation of tolerance of religious expression on the grounds of harm. I examine this claim with reference to three basic positions: Firstly,I examine Denise Meyerson’s argument that the domain of religion constitutes an area of intractable dispute and that the state is not entitled to limit liberty in this domain because it cannot justify limitations in a neutrally acceptable way. I argue that Ludin (...) is entitled to wear the Kopftuch on grounds of her right to religious freedom and that the attempt to deny her this entitlement constitutes a breach of individual rights. Meyerson’s arguments rest on the acceptability of Rawls’s idea of public reason. I therefore, secondly, examine Jeremy Waldron’s objections to the use of the deliberative discipline of public reason in cultural disputes as well as his objections to the use of the politics of identity which, he claims, distort our ability to engage in reasoned public debate. I argue that bracketing identity claims eliminates what is peculiar about Ludin’s case.This I bring out, thirdly, by drawing on the views of Melissa Williams, who advances the idea of sensitivity to others’ reasons as reasons, which defines a position midway between Meyerson and Waldron. It is apparent that Ludin’s dilemma is twofold: her status as ‘metic’-as member of a minority at the margins of mainstream German culture, and her status as ‘Muslimin’-as one believed to be suffering sexual discrimination in her own culture, form a double-bind of oppression. They are connected in a way that challenges the integration policies of the German state. (shrink)

In this article, I explore the relationship between the supersession thesis and the rights of future people. In particular, I show that changes in circumstances might supersede future people’s rights. I argue that appropriating resources that belong to future people does not necessarily result in a duty to return the resources in full. I explore how these findings are relevant for climate change justice. Assuming future generations of developing countries originally had a right to use a certain amount of the (...) carbon budget, changing circumstances could result in rights-supersession. Consequently, members of future generations of industrialized countries may be allowed to use part of the share of the carbon budget belonging to developing countries. (shrink)

This article is part of a symposium on property-owning democracy. In A Theory of Justice John Rawls argued that people in a just society would have rights to some forms of personal property, whatever the best way to organise the economy. Without being explicit about it, he also seems to have believed that protection for at least some forms of privacy are included in the Basic Liberties, to which all are entitled. Thus, Rawls assumes that people are entitled to form (...) families, as well as personal associations which reflect their tastes as well as their beliefs and interests. He seems also to have assumed that people are entitled to seclude themselves, as well as to associate with others, and to keep some of their beliefs, knowledge, feelings and ideas to themselves, rather than having to share them with others. So, thinking of privacy as an amalgam of claims to seclusion, solitude, anonymity and intimate association, we can say that Rawls appears to include at least some forms of privacy in his account of the liberties protected by the first principle of justice. -/- However, Rawls did not say very much about how he understands people’s claims to privacy, or how those claims relate to his ideas about property-ownership. This is unfortunate, because two familiar objections to privacy seem particularly pertinent to his conception of the basic liberties. The first was articulated with customary panache by Judith Thomson, in a famous article on the moral right to privacy, in which she argued that talk of a moral right to privacy is confused and confusing, because privacy rights are really just property rights in disguise. The second objection has long been a staple of leftist politics, and is that the association of privacy with private property means that privacy rights are just a mask for coercive and exploitative relationships, and therefore at odds with democratic freedom, equality and solidarity. If the first objection implies that Rawls is wrong to think that protection for privacy can be distinguished from protection of personal property, the second objection implies that Rawls cannot hope to protect privacy without thereby committing himself to the grossest forms of capitalist inequality. -/- In this paper I will not discuss Rawls’ views of property-owning democracy. However, by clarifying the relationship between claims to privacy and claims to property-ownership, I hope to illuminate some of the conceptual, moral and political issues raised by Rawls’ ideas, and by work on the concept of a property-owning democracy, which he inspired. As we will see, privacy-based justifications of private ownership are not always unappealing, and privacy is sometimes promoted, rather than threatened, by collective ownership. The conclusion draws out the significance of these claims for the idea of a property-owning democracy. (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)

The concept of instantiation is realized differently across a variety of metaphysical theories. A certain realization of the concept in a given theory depends on what roles are specified and associated with the concept and its corresponding term as well as what entities are suited to fill those roles. In this paper, the classic realization of the concept of instantiation in a one-category ontology of abstract particulars or tropes is articulated in a novel way and defended against unaddressed objections.

One way to frame the problem of moral luck is as a contradiction in our ordinary ideas about moral responsibility. In the case of two identical reckless drivers where one kills a pedestrian and the other does not, we tend to intuit that they are and are not equally blameworthy. The Character Response sorts these intuitions in part by providing an account of moral responsibility: the drivers must be equally blameworthy, because they have identical character traits and people are originally (...) praiseworthy and blameworthy in virtue of, and only in virtue of, their character traits. After explicating two versions of the Character Response, I argue that they both involve implausible accounts of moral responsibility and fail to provide a good solution to the problem of moral luck. I close by noting how proponents of moral luck can preserve a kernel of truth from the Character Response to explain away the intuition that the drivers are equally blameworthy. (shrink)

While first-person methods are essential for a science of consciousness, it is controversial what form these methods should take and whether any such methods are reliable. I propose that first-person experiments are a reliable method for investigating conscious experience. I outline the history of these methods and describe their characteristics. In particular, a first-person experiment is an intervention on a subject's experience in which independent variables are manipulated, extraneous variables are held fixed, and in which the subject makes a phenomenal (...) judgement about the target experience of the investigation. I examine historical and contemporary examples of first-person experiments: Mariotte’s demonstration of the visual blind spot, Kanizsa’s subjective contours, the Tse Illusion, and investigations of the non-uniform resolution of the visual field. I discuss the role that phenomenal contrast plays in these methods, and how they overcome typical introspective errors. I argue that their intersubjective repeatability is an important factor in their scientific status, however, it is not the only factor. That they control for extraneous factors and confounds is another factor which sets them apart from pseudoscience (e.g., the perception of auras), and hence another reason for classifying them as genuine experiments. Furthermore, by systematically mapping out the structure of visual experience, these methods make scientific progress. Praises of such first-person experimental approaches may not always be sung by philosophers and psychologists, but they continue to flourish as respectable scientific methods nevertheless. (shrink)

All humans have an equal basic moral status. They possess the same fundamental rights, and the comparable interests of each person should count the same in calculations that determine social policy. Neither supposed racial differences, nor skin color, sex, sexual orientation, ethnicity, intelligence, nor any other differences among humans negate their fundamental equal worth and dignity. These platitudes are virtually universally affirmed. A white supremacist racist or an admirer of Adolf Hitler who denies them is rightly regarded as beyond the (...) pale of civilized dialogue. However, a very simple line of argument developed by Peter Singer challenges our understanding of these platitudes and forces us to rethink the basis and nature of the moral equality of all humans. What I call the “Singer Problem” arises if one accepts that the morally significant cognitive capacities that are relevant to the determination of the fundamental moral status of a being vary from individual to individual by degree. The problem is to specify a moral principle determining fundamental moral status that assigns a superior status to humans compared to other animals on the basis of the superior cognitive capacities of humans but also assigns all human persons an equal fundamental moral status regardless of their differing cognitive capacities. More broadly posed, the problem is to specify moral principles that yield intuitively satisfactory implications for the treatment of human individuals and other individual animals given that cognitive capacities differ across species and individuals. A search for a resolution of the Singer problem leads to disappointing results. (shrink)

According to reductive intellectualists about knowledge-how :147–190, 2008; Philos Phenomenol Res 78:439–467, 2009) knowledge-how is a kind of knowledge-that. To the extent that this is right, then insofar as we might conceive of ways knowledge could be extended with reference to active externalist :7–19, 1998; Clark in Supersizing the mind: embodiment, action, and cognitive extension: embodiment, action, and cognitive extension. Oxford University Press, Oxford, 2008) approaches in the philosophy of mind, we should expect no interesting difference between the two. However, (...) insofar as anti-intellectualist approaches to knowledge-how are a viable option, there is an overlooked issue of how knowledge-how might be extended, via active externalism, in ways very differently from knowledge-that. This paper explores this overlooked space, and in doing so, illustrates how a novel form of extended knowledge-how emerges from a pairing of active externalism in the philosophy of mind with anti-intellectualism in the theory of knowledge. Crucial to our argument will be a new way of thinking about the extended mind thesis, as it pertains to the kinds of state one is in when one knows how to do something, and how this state connects with non-accidentally successful performance. (shrink)

The principle of energy conservation is widely taken to be a se- rious difficulty for interactionist dualism (whether property or sub- stance). Interactionists often have therefore tried to make it satisfy energy conservation. This paper examines several such attempts, especially including E. J. Lowe’s varying constants proposal, show- ing how they all miss their goal due to lack of engagement with the physico-mathematical roots of energy conservation physics: the first Noether theorem (that symmetries imply conservation laws), its converse (that conservation (...) laws imply symmetries), and the locality of continuum/field physics. Thus the “conditionality re- sponse”, which sees conservation as (bi)conditional upon symme- tries and simply accepts energy non-conservation as an aspect of interactionist dualism, is seen to be, perhaps surprisingly, the one most in accord with contemporary physics (apart from quantum mechanics) by not conflicting with mathematical theorems basic to physics. A decent objection to interactionism should be a posteri- ori, based on empirically studying the brain. (shrink)

We developed and tested a behavioral version of the Defining Issues Test-1 revised (DIT-1r), which is a measure of the development of moral judgment. We conducted a behavioral experiment using the behavioral Defining Issues Test (bDIT) to examine the relationship between participants’ moral developmental status, moral competence, and reaction time when making moral judgments. We found that when the judgments were made based on the preferred moral schema, the reaction time for moral judgments was significantly moderated by the moral developmental (...) status. In addition, as a participant becomes more confident with moral judgment, the participant differentiates the preferred versus other schemas better particularly when the participant’s abilities for moral judgment are more developed. (shrink)

In The Construction of Social Reality, John Searle develops a theory of institutional facts and objects, of which money, borders and property are presented as prime examples. These objects are the result of us collectively intending certain natural objects to have a certain status, i.e. to ‘count as’ being certain social objects. This view renders such objects irreducible to natural objects. In this paper we propose a radically different approach that is more compatible with standard economic theory. We claim that (...) such institutional objects can be fully understood in terms of actions and incentives, and hence the Searlean apparatus solves a non-existent problem. (shrink)

Some legal theorists say that legal entrapment to commit a crime is incoherent. So far, there is no satisfactorily precise statement of this objection in the literature: it is obscure even as to the type of incoherence that is purportedly involved. (Perhaps consequently, substantial assessment of the objection is also absent.) We aim to provide a new statement of the objection that is more precise and more rigorous than its predecessors. We argue that the best form of the objection asserts (...) that, in attempting to entrap, law-enforcement agents lapse into a form of practical incoherence that involves the attempt simultaneously to pursue contrary ends. We then argue that the objection, in this form, encompasses all cases of legal entrapment only if it is supplemented by appeal to the premise that law-enforcement agents have an absolute duty never to create crimes. (shrink)

Turner argues that computer programs must have purposes, that implementation is not a kind of semantics, and that computers might need to understand what they do. I respectfully disagree: Computer programs need not have purposes, implementation is a kind of semantic interpretation, and neither human computers nor computing machines need to understand what they do.

This paper introduces a model for evidence denial that explains this behavior as a manifestation of rationality and it is based on the contention that social values (measurable as utilities) often underwrite these sorts of responses. Moreover, it is contended that the value associated with group membership in particular can override epistemic reason when the expected utility of a belief or belief system is great. However, it is also true that it appears to be the case that it is still (...) possible for such unreasonable believers to reverse this sort of dogmatism and to change their beliefs in a way that is epistemically rational. The conjecture made here is that we should expect this to happen only when the expected utility of the beliefs in question dips below a threshold where the utility value of continued dogmatism and the associated group membership is no longer sufficient to motivate defusing the counter-evidence that tells against such epistemically irrational beliefs. (shrink)

The purpose of this paper is to think about the various methods of attempting to make money in the capital markets (“investing”). I suggest that though running a betting system on a Roulette wheel is silly, running a betting system on the capital markets may be a good idea.

Psychologists and philosophers have not yet resolved what they take implicit attitudes to be; and, some, concerned about limitations in the psychometric evidence, have even challenged the predictive and theoretical value of positing implicit attitudes in explanations for social behavior. In the midst of this debate, prominent stakeholders in science have called for scientific communities to recognize and countenance implicit bias in STEM fields. In this paper, I stake out a stakeholder conception of implicit bias that responds to these challenges (...) in ways that are responsive to the psychometric evidence, while also being resilient to the sorts of disagreements and scientific progress that would not undermine the soundness of this call. Along the way, my account advocates for attributing collective (group-level) implicit attitudes rather than individual-level implicit attitudes. This position raises new puzzles for future research on the relationship (metaphysical, epistemic, and ethical) between collective implicit attitudes and individual-level attitudes. (shrink)

Whether or not it is coherent to place hope in a future life beyond the grave has become a central question in the larger debate about whether a materialist view of human persons can accommodate Christian belief. Hud Hudson defends a four-dimensional account of resurrection in order to avoid persistent difficulties experienced by three-dimensionalist animalism. I present two difficulties unique to Hudson’s view. The first problem of counterpart hope is a manifestation of a general weakness of four-dimensional views to accommodate (...) adequately prudential concern about one’s future self. More significantly, the second problem of quasi hope demonstrates that even if a temporal parts view can accommodate the possibility of future resurrection it necessarily leaves human beings in the dark about their individual futures and thus incapable of hope. I conclude that whatever its merits in demonstrating the possibility of resurrection, four-dimensionalist materialism cannot accommodate veridical Christian hope. (shrink)

Differential privacy (DP) aims to confer data processing systems with inherent privacy guarantees, offering strong protections for personal data. But DP’s approach to privacy carries with it certain assumptions about how mathematical abstractions will be translated into real-world systems, which—if left unexamined and unrealized in practice—could function to shield data collectors from liability and criticism, rather than substantively protect data subjects from privacy harms. This article investigates these assumptions and discusses their implications for using DP to govern data-driven systems. In (...) Parts 1 and 2, we introduce DP as, on one hand, a mathematical framework and, on the other hand, a kind of real-world sociotechnical system, using a hypothetical case study to illustrate how the two can diverge. In Parts 3 and 4, we discuss the way DP frames privacy loss, data processing interventions, and data subject participation, arguing it could exacerbate existing problems in privacy regulation. In part 5, we conclude with a discussion of DP’s potential interactions with the endogeneity of privacy law, and we propose principles for best governing DP systems. In making such assumptions and their consequences explicit, we hope to help DP succeed at realizing its promise for better substantive privacy protections. (shrink)

Strategic Reliabilism is a framework that yields relative epistemic evaluations of belief-producing cognitive processes. It is a theory of cognitive excellence, or more colloquially, a theory of reasoning excellence (where 'reasoning' is understood very broadly as any sort of cognitive process for coming to judgments or beliefs). First introduced in our book, Epistemology and the Psychology of Human Judgment (henceforth EPHJ), the basic idea behind SR is that epistemically excellent reasoning is efficient reasoning that leads in a robustly reliable fashion (...) to significant, true beliefs. It differs from most contemporary epistemological theories in two ways. First, it is not a theory of justification or knowledge – a theory of epistemically worthy belief. Strategic Reliabilism is a theory of epistemically worthy ways of forming beliefs. And second, Strategic Reliabilism does not attempt to account for an epistemological property that is assumed to be faithfully reflected in the epistemic judgments and intuitions of philosophers. If SR makes recommendations that accord with our reflective epistemic judgments and intuitions, great. If not, then so much the worse for our reflective epistemic judgments and intuitions. (shrink)

The standard taxonomy of theories of epistemic justification generates four positions from the Foundationalism v. Coherentism and Internalism v. Externalism disputes. I develop a new taxonomy driven by two other distinctions: Fundamentalism v. Non-Fundamentalism and Actual-Result v. Proper-Aim conceptions of epistemic justification. Actual-Result theorists hold that a belief is justified only if, as an actual matter of fact, it is held or formed in a way that makes it more likely than not to be true. Proper-Aim theorists hold that a (...) belief is justified only if it is held or formed in a way that it proper or correct insofar as truth is the aim or norm. Fundamentalists hold that which particular ways of holding or forming beliefs that confer justification is knowable a priori; epistemic principles are a priori necessary truths. Non- Fundamentalists disagree; epistemic principles are empirical contingent truths. The new taxonomy generates four positions: Cartesianism, Reliabilism, Intuitionism, and Pragmatism. The first two are Actual-Result; the second two are Proper-Aim. The first and third are Fundamentalist, the second and fourth are Non-Fundamentalist. The new taxonomy illuminates much of the current debate in the theory of epistemic justification. (shrink)