The theories of cultural anthropologist Ernest Becker arise from an existential and psychological analysis of the death terror/anxiety deep in the unconscious of every human. Becker details how this anxiety governs the ideologies and behaviors of our species—something now confirmed by thousands of experiments performed by psychologists engaged in contemporary terror management theory (TMT). Humans manage their anxiety through what Becker terms “hero systems”—concepts, beliefs, and myths we create to give us a sense of significance and meaning during, and even (...) beyond our mortal lives. Today, many dominant economic, technological, and religious hero systems seek to confirm our significance by denying that we are—like all other species—animals who must exist in a decaying, mortal body. Becker shows how this attempt to deny our “creatureliness” (basic biological nature) causes humans to stand against the natural world we are embedded in, leading to an assault on the planet and nonhuman animals. As a result, Becker believed pacifism was the only hero system capable of keeping humankind from destroying itself and the earth. Pacifism is the precursor to the more encompassing ethical concept of “reverence for life,” advocated by Dr. Albert Schweitzer. By respecting the will-to-live in all sentient beings, reverence for life transcends concern for humans alone and extends moral and physical safeguards to life as such. Confronting the fact that humans are increasingly alienated from their commodified world and their own being, reverence for life stands as a vital solution to many of our modern problems. And following contemporary TMT research, reverencing life can also expand one’s self-esteem, which research shows lowers death anxiety, reduces aggression, and offers authentic meaning to life itself. (shrink)

Paul Tillich (1886-1965) is generally considered the most original and influential Christian theologian of the 20th century. What's not as widely recognized, outside of academic circles, is his stature as a first-rate existentialist philosopher—in the lineage of Kierkegaard, Heidegger, Nietzsche, and Pascal. Few people have analyzed more areas of existence: from art and architecture to culture, science, economics, politics, technology, psychology, world religions (particularly Buddhism), history, and health and healing. But one of Tillich's primary and enduring concerns was humanity's troubled (...) relationship with the natural world. It was his belief that empathizing with and defending nature was of vital importance to the human spirit, bringing great depth and meaning to our experience of life itself. -/- Though the 1962 publication of Rachel Carson's "Silent Spring" is seen as a pivotal moment in awakening the environmental movement, Tillich was writing decades before this of the commodification and desecration of the natural world. He witnessed the rise of industrialization and the power of this synthetic world to bend humanity to its demands, and warned that “we are living in the late stage of the self-destruction of industrial society, as a world above the given world of nature." Though creative in many respects, he also saw this technical enterprise impoverishing our spiritual lives and inflicting untold suffering on a defenseless planet and our fellow nonhuman animals. -/- With great implications for environmental ethics, a central part of Tillich’s theology is his “multidimensional unity of life,” a unique scientific and moral perspective that vastly expands our concept of life, granting deep significance to even the inorganic dimension. Perhaps most importantly, Tillich challenges religious views that see life on this planet as subordinate to the "real" lives to come after death, famously stating that “there is no salvation [salvus: to heal and make whole] of man if there is no salvation of nature, for man is in nature and nature is in man." -/- In this timely and original assessment of Tillich, Yunt provides a philosophical bulwark against the modern world's increasing assault on science, reason, and nature. And by examining contemporary environmental movements such as deep ecology and ecopsychology, as well as current issues like climate change and the impact of human diet and new technologies on the planet, Yunt brings clarity to the increasingly obvious fact that humans are within the realm of the natural world, not above it. (shrink)

MY CHAPTER CONTRIBUTION: "Paul Tillich's Enduring Relevance to Ecophilosophy and Environmental Ethics" *** -/- BOOK DESCRIPTION: Paul Tillich's ideas and methods continue to inspire and guide students, teachers, and professionals in all fields. He crosses boundaries between the academy and the community, religions and spiritualities, cultures and societies, taking leaders deeper and further than they ever imagined. Tillich is a master of conversation. His thought bridges social polarizations, program silos, and educational specialization. His ideas cannot be contained in a closed (...) system. His methodology has the power to engage other philosophies of life, religions and spiritualities, scientific research, culture shifts, and lifestyle diversity critically and appreciatively. Tillich is also a master of confrontation. His thought challenges political structures, racial and gender inequalities, and social injustice. He is an acute observer of social change and struggles courageously with moral quandaries. He inspires action for today and hope for tomorrow. Each essay explores another facet of Tillich's influence in education, religion, popular culture, science, health, social reform, and political action. They are chosen to be "snapshots" of his ongoing influence, accessible to both undergraduate and graduate students, and relevant to corporate and non-profit leaders alike. Reading this book will open your eyes to discern Tillich's hidden presence in academic curricula, contemporary research, political speeches and social policies, entertainment and internet, books and podcasts, and social media. Tillich can be your intellectual companion in whatever endeavor you choose to pursue. -/- . (shrink)

A review of Abbey-Anne Smith's book "Animals in Tillich's Philosophical Theology.".

This paper examines the lack of philosophical/moral clarity at the root of speciesism. Focusing on the many reasons animal rights deserves a closer look, it investigates such issues as animal experimentation, human diet, and what should be the foundation of our moral reasoning when dealing with human and nonhuman animal relationships.

"A powerfully written work" —Dr. Peter Singer, Princeton University, author of "Animal Liberation" (1975) ***** -/- In this wide-ranging and accessible book, Yunt offers a brief survey of some of the most vital historical, scientific, philosophical, and even religious aspects of animal liberation. Making connections between sexism, racism, homophobia, and speciesism, he shows why nonhuman animals are the last group of sentient beings to gain rights, as well as how the movement to extend basic rights to them—something increasing with (...) each generation—is emerging as the historical and moral end goal humanity has been moving toward throughout its evolution. What’s partly aided this evolution are scientific discoveries unveiling the biological and moral relatedness of humans and nonhuman animals. If such facts begin to inform our ethics, then our awareness of these primal bonds—such as suffering, empathy, sorrow, and joy—will enable humanity to move away from its role as oppressor, and into one of cohabitant and caretaker of the planet and other beings. The devastating issues related to our current exploitation of other species—human health epidemics, environmental catastrophes, and the unnecessary brutality against other sentient life—will finally be confronted in earnest, and it will become apparent that the embrace of animal liberation is, in fact, the beginning of true human liberation. (shrink)

Cognitivism about the emotions is the view that emotions involve judgments (or quasi-judgmental cognitive states) that we could, in principle, articulate without reference to the emotions themselves. D’Arms and Jacobson (2003) argue that no such articulation is available in the case of “possessive” emotions, such as pride and guilt, and, so, cognitivism (in regard to such emotions, at least) is false. This article proposes and defends a cognitivist account of our partiality to the objects of our pride. I argue that (...) taking pride in something requires judging that your relation to that thing indicates that your life accords with some of your personal ideals. This cognitivist account eschews glossing pride in terms of one’s “possession” of what one is proud of and, so, escapes D’Arms and Jacobson’s critique. I motivate this account by critically assessing the most sophisticated possession-based account of pride in the literature, found in Gabriele Taylor (1985). (shrink)

A three dimensional hypercube representing all of the 4,096 dyadic computations in a standard bivalent system has been created. It has been constructed from the 16 functions arrayed in a table of functional completeness that can compute a dyadic relationship. Each component of the dyad is an operator as well as a function, such as “implication” being a result, as well as an operation. Every function in the hypercube has been color keyed to enhance the display of emerging patterns. At (...) the minimum, the hypercube is a “multiplication table” of dyadic computations and produces values in a way that shortens the time to do operations that normally would take longer using conventional truth table methods. It also can serve as a theorem prover and creator. With the hypercube comes a deductive system without the need for axioms. The main significance of the 3-D hypercube at this point is that it is the most fundamental way of displaying all dyadic computations in binary space, thus serving as a way of normalizing the rendition of uninterpreted, or raw, binary space. The hypercube is a dimensionless entity, a standard by which in binary spaces can be measured and classified, analogous to a meter stick. (shrink)

Commentators have often been puzzled by the structure of the _Symposium_; in particular, it is unclear what the relationship is between Socrates’ speech and that of the other symposiasts. This chapter seeks to make a contribution to that debate by highlighting parallels between the first four speeches of the _Symposium_ and the goals of the early education in the Republic. In both dialogues, I contend, we see Plato concerned with educating people through (a) activating and cultivating spirited motivations, (b) becoming (...) lawful and taking virtue as a goal, (c) harmonizing the opposing forces in their soul, and (d) minimizing the appetites and making them orderly. While these are familiar points from the moral education of the Republic, I argue that they also map onto the first four speeches of the _Symposium_ respectively. Because in the _Republic_ this moral education is necessary to make progress on the epistemic ascent, we can speculate that there is a similar point to be made in the _Symposium_ – without first training our character adequately, we will not be able to climb the ladder of love. While the positive effects of Eros described in the early speeches of the _Symposium_ are only imitations of the ideal education regime of Kallipolis, they nevertheless improve one’s character in such a way that better prepares the soul for philosophy. Finally, I argue that the importance of this moral education is dramatized at the end of the _Symposium_ through Agathon’s amicable refutation by Socrates on the one hand, and the drunken entrance of Alcibiades on the other. Agathon shows potential for philosophy whereas Alcibiades is the exemplar of what happens when somebody comes to philosophy without a harmonized soul. (shrink)

In order to graduate, Florida's high school students by law must learn that Communism is evil, dangerous, and fallacious. All students must learn that the U.S. produces the highest standard of living and more freedom than any other economic system on earth. State universities in Florida are creating a curriculum to implement the Americanism versus Communism Act of 1961 and the Free Enterprise and Consumer Education Act of 1975. ;The Florida Department of Education says that ideology, noncritical thinking, is superior (...) to critical thinking and that the superiority of the U.S. political economy and the dignity of the individual rest in part on peoples' being able to express themselves freely. ;Florida's A.V.C. and F.E.C.E.A. proponents have a special way of convincing audiences that they will develop loyalty while at the same time imposing a set of ideas not open to question. ;This work argues that, intentionally or not, Florida's legislature and Department of Education have set up an official ideology and the mechanism to purvey it. This ideological approach defeats the aim of comparing systems objectively. While the stated aim is to promote critical thinking, the D.O.E.'s special philosophy underscoring words like "democracy" results in indoctrinating students with a questionable description of the U.S. system. (shrink)

The primary interpretative challenge for understanding Parmenides’ poem revolves around explaining both the meaning of, and the relationship between, its two primary sections: a) the positively endorsed metaphysical arguments which describe some unified, unchanging, motionless, and eternal “reality”, and b) the ensuing cosmology, which incorporates the very principles explicitly denied in Aletheia. I will refer to this problem as the “A-D Paradox.” I advocate resolving this paradoxical relationship by reading Parmenides’ poem as a ring-composition, and incorporating a modified version of (...) Palmer’s modal interpretation of Aletheia. On my interpretation, Parmenides’ thesis in Aletheia is not a counter-intuitive description of how all the world must truly be, but rather a radical rethinking of divine nature. Understanding Aletheia in this way, the ensuing “cosmology” can be straightforwardly rejected as an exposition of how traditional, mythopoetic accounts have misled mortals in their understanding of divinity. Not only does this interpretative view provide a resolution to the A-D Paradox, it offers a more holistic account of the poem by making the opening lines of introduction integral to understanding Parmenides’ message. By setting forth its own unacceptable fiction, paralleling the elements of the Doxa in a ring-composition, the Proem simultaneously establishes the scope of the ensuing inquiry, and its target. Maintaining Parmenides’ historical position as the “father of metaphysics,” the narrative that he advanced a strictly secular account of all reality is challenged. Instead, Parmenides is best understood as further advancing Xenophanes’ criticisms of traditional religion, an intellectual relationship which the ancient testimonia strongly supports. (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)

Reportedly ever since Pythagoras, but possibly much earlier, humans have been concerned about the way non human animals (henceforward “animals” for convenience) should be treated. By late antiquity all main traditions with regard to this issue had already been established and consolidated, and were only slightly modified during the centuries that followed. Until the nineteenth century philosophers tended to focus primarily on the ontological status of animals, to wit on whether – and to what degree – animals are actually rational (...) beings; accordingly they allowed – or denied – them some kind of moral standing. This modus operandi was for the first time seriously questioned by Jeremy Bentham, who put the issue on a different track. If the question, as Bentham suggested, is not if animals can think or speak, but if they can suffer1, then it seems plausible that moral agents ought to abstain from inflicting unnecessary suffering on animals; in other words, humans might have at least one – even limited – moral duty towards animals. And if this, in turn, is true, then animals should arguably be allowed the commensurate moral right, namely the right not to be inflicted unnecessary pain. Then, if animals possess this right, they could probably possess others, as well. This is how grosso modo the issue of animal rights became a pivotal part of the discussion concerning animal ethics. Bentham himself, of course, wouldn’t have gone that far; to him even the idea of human rights sounded like “simple… rhetorical nonsense upon stilts”.2 It was mostly due to his views, however, that the debate was moved from the way things actually are to the way things should ideally be – thus merging into what, in my view, should always have been: one primarily concerning ethics. (shrink)

Élie HALÉVY (1870-1937), philosophe et historien des idées, fut professeur à l'École libre des sciences politiques, l'ancêtre de l'actuel Sciences Po. Comme son autre grand ouvrage, l'Histoire du peuple anglais au XIXe siècle, paru en six tomes de 1913 à 1932, les trois tomes de La formation du radicalisme philosophique, parus en 1901 pour les deux premiers et en 1904 pour le troisième, reflètent pour partie ses enseignements de l'Ecole libre consacrés à l'histoire britannique. Le premier tome, La jeunesse de (...) Bentham 1776-1789, étudie la doctrine utilitariste non seulement chez celui qu'on regarde comme son fondateur principal, Jeremy Bentham, mais aussi chez les nombreux auteurs qui, en Grande-Bretagne et sur le continent, en dessinèrent avant lui les contours. Le deuxième tome, L’évolution de la doctrine utilitaire de 1789 à 1815, montre comment l'utilitarisme revêtit la forme non seulement d'une école de pensée, mais aussi d'un mouvement pour la réforme économique, sociale et politique. Le rôle coordonnateur nouveau de James Mill, ainsi qu'une convergence de vues avec les économistes, qui poussaient dans le sens des réformes, marquèrent notamment cette évolution. Le troisième tome, Le radicalisme philosophique, continue d'étudier la transformation de l'école en mouvement après la fin des guerres napoléoniennes, lorsque celle-ci commence à engranger ses premiers grands succès réformistes. Bentham, James Mill et les autres penseurs utilitaires sont alors réunis sous l'appellation de philosophic radicals. Le terme temporel de l'ouvrage est le Reform Act de 1832, première étape vers la modernisation du système électoral, que la propagande de ce groupe ne contribua pas peu à faire aboutir. Quoique l'ouvrage d'Halévy vaille en premier lieu par l'immense savoir qu'il déploie, et le nombre et l'excellence des citations qu'il propose, il comporte aussi des thèses historiques et philosophiques originales. On peut citer parmi les premières la thèse, qui relie les trois tomes, voulant que l'utilitarisme britannique trouve sa forme achevée dans l'intervention sur la société, lorsqu'il se mue en radicalisme philosophique, et parmi les secondes, la thèse, énoncée au début du premier tome, voulant qu'il existe trois modèles dominants de jonction des intérêts individuels (la fusion sympathique, l'identification naturelle et l'identification artificielle). Une autre grande thèse, à la fois historique et philosophique, affirme en substance que l'économie politique classique serait un département spécialisé de la pensée utilitaire. La question de savoir jusqu'à quel point Smith, Ricardo et Malthus ont pu adhérer au "principe d'utilité" de Bentham est toujours débattue. En même temps que les élucidations apportées à ce principe, elle contribue à expliquer l'intérêt que les historiens de la pensée économique continuent de porter à l'ouvrage. L'auteur a participé à la réédition de La formation du radicalisme philosophique en 1995 par les Presses Universitaires de France (P.U.F.), suivant un projet collectif lancé par Monique Canto-Sperber. Dans le présent article, antérieur à cette réédition, l'auteur tentait de résumer brièvement un livre qui demeure irremplaçable en dépit d'une conception et d'un style quelque peu datés. (shrink)

Les Cahiers philosophiques de Strasbourg 52 contains an Introduction and 9 new research articles in French & English on Friedrich Schiller's philosophy in relation to German Idealism. All fully available online on Open-Edition and as free e-book. -/- Edited and introduced by Henny Blomme, Laure Cahen-Maurel, & David W. Wood. With contributions by Frederick C. Beiser, María del Rosario Acosta López, Cody Staton, Jeremy D. Hovda, Laure Cahen-Maurel, Quentin Landenne, Katia Hay, Louis Carré, and Charlotte Morel. -/- SOMMAIRE / (...) CONTENTS -/- Introduction: Friedrich Schiller, a German Idealist? (Henny Blomme, Laure Cahen-Maurel & David W. Wood) -/- 1. Frederick C. Beiser. Schiller’s Humanism -/- 2. María del Rosario Acosta López. Une dimension esthétique de la critique : la temporalité du beau dans les lettres de Schiller Sur l’éducation esthétique -/- 3. Cody Staton. In Search of Play: Schiller’s Drive Theory as a Turn Away from Kant -/- 4. Jeremy D. Hovda. Bildung between Kant and Schiller -/- 5. Laure Cahen-Maurel. Fichte avec Schiller : La querelle des Heures à la lumière de Grâce et Dignité -/- 6. Quentin Landenne. La Bildung chez Schiller et Fichte, entre esthétique et politique -/- 7. Katia Hay. On the Tragic-Sublime and Tragic Freedom: Thinking with Schiller and Schelling -/- 8. Louis Carré. Vicissitudes de l’État organique : Kant, Hegel, Schiller -/- 9. Charlotte Morel. Conjoindre idéalisme et réalisme après Hegel : Les lectures de Schiller par Lotze et Lange -/- Résumés / Abstracts. (shrink)

Dans un texte désormais célèbre, Ferdinand de Saussure insiste sur l’arbitraire du signe dont il vante les qualités. Toutefois il s’avère que le symbole, signe non arbitraire, dans la mesure où il existe un rapport entre ce qui représente et ce qui est représenté, joue un rôle fondamental dans la plupart des activités humaines, qu’elles soient scientifiques, artistiques ou religieuses. C’est cette dimension symbolique, sa portée, son fonctionnement et sa signification dans des domaines aussi variés que la chimie, la théologie, (...) les mathématiques, le code de la route et bien d’autres qui est l’objet du livre La Pointure du symbole. -/- Jean-Yves Béziau, franco-suisse, est docteur en logique mathématique et docteur en philosophie. Il a poursuivi des recherches en France, au Brésil, en Suisse, aux États-Unis (UCLA et Stanford), en Pologne et développé la logique universelle. Éditeur-en-chef de la revue Logica Universalis et de la collection Studies in Universal Logic (Springer), il est actuellement professeur à l’Université Fédérale de Rio de Janeiro et membre de l’Académie brésilienne de Philosophie. SOMMAIRE -/- PRÉFACE L’arbitraire du signe face à la puissance du symbole Jean-Yves BÉZIAU La logique et la théorie de la notation (sémiotique) de Peirce (Traduit de l’anglais par Jean-Marie Chevalier) Irving H. ANELLIS Langage symbolique de Genèse 2-3 Lytta BASSET -/- Mécanique quantique : quelle réalité derrière les symboles ? Hans BECK -/- Quels langages et images pour représenter le corps humain ? Sarah CARVALLO Des jeux symboliques aux rituels collectifs. Quelques apports de la psychologie du développement à l’étude du symbolisme Fabrice CLÉMENT Les panneaux de signalisation (Traduit de l’anglais par Fabien Shang) Robert DEWAR Remarques sur l’émergence des activités symboliques Jean LASSÈGUE Les illustrations du "Songe de Poliphile" (1499). Notule sur les hiéroglyphes de Francesca Colonna Pierre-Alain MARIAUX Signes de vie Jeremy NARBY Visualising relations in society and economics. Otto Neuraths Isotype-method against the background of his economic thought Elisabeth NEMETH Algèbre et logique symboliques : arbitraire du signe et langage formel Marie-José DURAND – Amirouche MOKTEFI Les symboles mathématiques, signes du Ciel Jean-Claude PONT La mathématique : un langage mathématique ? Alain M. ROBERT. (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)

“Love hurts”—as the saying goes—and a certain amount of pain and difficulty in intimate relationships is unavoidable. Sometimes it may even be beneficial, since adversity can lead to personal growth, self-discovery, and a range of other components of a life well-lived. But other times, love can be downright dangerous. It may bind a spouse to her domestic abuser, draw an unscrupulous adult toward sexual involvement with a child, put someone under the insidious spell of a cult leader, and even inspire (...) jealousy-fueled homicide. How might these perilous devotions be diminished? The ancients thought that treatments such as phlebotomy, exercise, or bloodletting could “cure” an individual of love. But modern neuroscience and emerging developments in psychopharmacology open up a range of possible interventions that might actually work. These developments raise profound moral questions about the potential uses—and misuses—of such anti-love biotechnology. In this article, we describe a number of prospective love-diminishing interventions, and offer a preliminary ethical framework for dealing with them responsibly should they arise. (shrink)

John Stuart Mill and Jeremy Bentham are often said to have held opposed views concerning the way “the value” of different pleasures should be estimated. Mill is accused of being an inconsistent utilitarian because he thought that, when comparing the value of two pleasures, we should not forget to take their “quality” into account. Bentham, on the other hand, is said to have believed that we should take “only quantity” into consideration. By verifying what they actually wrote, and reflecting (...) on what they meant by words like “value”, “quantity”, and “quality”, we find that these allegations are largely imaginary and that the difference between Mill and Bentham on this question has (at least) been exaggerated. Bentham, for example, did not write that "quantity of pleasure being equal, pushpin is as good as poetry", as is so often reported. In his Principles of Morals and Legislation he clearly tells us why he rejects the inaccurate word “quantity”, when speaking of “the value of (a lot of) pain or pleasure”, and he explicitly introduces “quality” – both the word and the concept – in his analysis of rewards and punishments. These clarifications allow us to sort-out a few other confusions concerning utilitarianism. We explain, for example, why authors like Amartya Sen and Michael Sandel are mistaken in believing that rights and freedoms have “no intrinsic value” (only instrumental value) in utilitarian ethics. (shrink)

Some scientific categories seem to correspond to genuine features of the world and are indispensable for successful science in some domain; in short, they are natural kinds. This book gives a general account of what it is to be a natural kind and puts the account to work illuminating numerous specific examples.

Given the fact that many people use Wikipedia, we should ask: Can we trust it? The empirical evidence suggests that Wikipedia articles are sometimes quite good but that they vary a great deal. As such, it is wrong to ask for a monolithic verdict on Wikipedia. Interacting with Wikipedia involves assessing where it is likely to be reliable and where not. I identify five strategies that we use to assess claims from other sources and argue that, to a greater of (...) lesser degree, Wikipedia frustrates all of them. Interacting responsibly with something like Wikipedia requires new epistemic methods and strategies. (shrink)

We offer a general framework for theorizing about the structure of knowledge and belief in terms of the comparative normality of situations compatible with one’s evidence. The guiding idea is that, if a possibility is sufficiently less normal than one’s actual situation, then one can know that that possibility does not obtain. This explains how people can have inductive knowledge that goes beyond what is strictly entailed by their evidence. We motivate the framework by showing how it illuminates knowledge about (...) the future, knowledge of lawful regularities, knowledge about parameters measured using imperfect instruments, the connection between knowledge, belief, and probability, and the dynamics of knowledge and belief in response to new evidence. (shrink)

In this issue, Ahmadi1 reports on the practice of hymenoplasty—a surgical intervention meant to restore a presumed physical marker of virginity prior to a woman's marriage. As Mehri and Sills2 have stated, these women ‘want to ensure that blood is spilled on their wedding night sheets.’ Although Ahmadi's research was carried out in Iran specifically, this surgery is becoming increasingly popular in a number of Western countries as well, especially among Muslim populations.3 What are the ethics of hymen restoration?Consider the (...) role of the physician. Two of the doctors interviewed by Ahmadi reported being in ‘a perpetual state of guilt because of the surgery's inherent aim at deceiving the groom’ and noted their ‘personal conflict’ at being involved in this deception. Yet: "None of the doctors believed that the surgery was unethical, arguing that the girl could be ‘abused’ and ‘can even die’ if she is discovered not … ". (shrink)

Systems of logico-probabilistic (LP) reasoning characterize inference from conditional assertions interpreted as expressing high conditional probabilities. In the present article, we investigate four prominent LP systems (namely, systems O, P, Z, and QC) by means of computer simulations. The results reported here extend our previous work in this area, and evaluate the four systems in terms of the expected utility of the dispositions to act that derive from the conclusions that the systems license. In addition to conforming to the dominant (...) paradigm for assessing the rationality of actions and decisions, our present evaluation complements our previous work, since our previous evaluation may have been too severe in its assessment of inferences to false and uninformative conclusions. In the end, our new results provide additional support for the conclusion that (of the four systems considered) inference by system Z offers the best balance of error avoidance and inferential power. Our new results also suggest that improved performance could be achieved by a modest strengthening of system Z. (shrink)

In this paper I engage interdisciplinary conversation on inaction as the dominant response to climate change, and develop an analysis of the specific phenomenon of complacency through a critical-feminist lens. I suggest that Chris Cuomo's discussion of the “insufficiency” problem and Susan Sherwin's call for a “public ethics” jointly point toward particularly promising harm-reduction strategies. I draw upon and extend their work by arguing that extant philosophical accounts of complacency are inadequate to the task of sorting out what it means (...) to be complacent on climate change. I offer a sketch for an alternative account, which I take to be a start in the direction of mapping out a diverse array of “motivational vices” that need to be named, grappled with, and remedied. (shrink)

How is what we believe related to how we act? That depends on what we mean by ‘believe’. On the one hand, there is what we're sure of: what our names are, where we were born, whether we are sitting in front of a screen. Surety, in this sense, is not uncommon — it does not imply Cartesian absolute certainty, from which no possible course of experience could dislodge us. But there are many things that we think that we are (...) not sure of. For example, you might think that it will rain sometime this month, but not be sure that it will. Both what we're sure of and what we think have important normative connections to action. But the connections are quite different. This paper explores these issues with respect to assertion, inquiry, and decision making. We conclude by arguing that there is no theoretically significant notion of ‘full belief’ intermediate in strength between thinking and being sure. (shrink)

When confronted with especially complex ecological and social problems such as climate change, how are we to think about responsibility for collective inaction? Social and political philosophers have begun to consider the complexities of acting collectively with a view to creating more just and sustainable societies. Some have recently turned their attention to the question of whether more or less formally organized groups can ever be held morally responsible for not acting collectively, or else for not organizing themselves into groups (...) capable of so doing. In this paper I argue that several questionable assumptions have shaped the character and scope of inquiry to this point, precluding us from grappling with a range of important questions concerning the epistemic dimensions of collective inaction. I offer an overview of recent conversation concerning collective inaction, advance a critique of the picture of responsibility that has emerged from this conversation, and propose an alternative approach to th... (shrink)

We argue that the value of authenticity does not explain the value of self-knowledge. There are a plurality of species of authenticity; in this paper we consider four species: avoiding pretense (section 2), Frankfurtian wholeheartedness (section 3), existential self-knowledge (section 4), and spontaneity (section 5). Our thesis is that, for each of these species, the value of (that species of) authenticity does not (partially) explain the value of self-knowledge. Moreover, when it comes to spontaneity, the value of (that species of) (...) authenticity conflicts with the value of self-knowledge. (shrink)

The Ockhamist claims that our ability to do otherwise is not endangered by God’s foreknowledge because facts about God’s past beliefs regarding future contingents are soft facts about the past—i.e., temporally relational facts that depend in some sense on what happens in the future. But if our freedom, given God’s foreknowledge, requires altering some fact about the past that is clearly a hard fact, then Ockhamism fails even if facts about God’s past beliefs are soft. Recent opponents of Ockhamism, including (...) David Widerker and Peter van Inwagen, have argued along precisely these lines. Their arguments, if successful, would undermine Ockhamism while avoiding the controversy over the alleged softness of facts about God’s past beliefs. But these arguments do not succeed. The past facts they rely on must be clear and uncontroversial examples of hard facts about the past, and these facts must be such that an ability to refrain from the relevant future action implies an ability to alter the relevant hard fact. We demonstrate the flaw in these arguments by showing how they rely on past facts that do not satisfy these criteria. The Ockhamist may have troubles, but this type of argument is not one of them. (shrink)

What are the effects of circumcision on sexual function and experience? And what does sex—in the sense related to gender—have to do with the ethics of circumcision? Jacobs and Arora (2015) give short shrift to the first of these questions; and they do not seem to have considered the second. In this commentary, I explore the relationship between sex (in both senses) and infant male circumcision, and draw some conclusions about the ongoing debate regarding this controversial practice.

When should you engage with difficult arguments against your cherished controversial beliefs? The primary conclusion of this book is that your obligations to engage with counterarguments are more limited than is often thought. In some standard situations, you shouldn't engage with difficult counterarguments and, if you do, you shouldn't engage with them open-mindedly. This conclusion runs counter to aspects of the Millian political tradition and political liberalism, as well as what people working in informal logic tend to say about argumentation. (...) -/- Not all misleading arguments wear their flaws on their sleeve. Each step of a misleading argument might seem compelling and you might not be able to figure out what's wrong with it. Still, even if you can't figure out what's wrong with an argument, you can know that it's misleading. One way to know that an argument is misleading is, counterintuitively, to lack expertise in the methods and evidence-types employed by the argument. When you know that a counterargument is misleading, you shouldn't engage with it open-mindedly and sometimes shouldn't engage with it at all. You shouldn't engage open-mindedly because you shouldn't be willing to reduce your confidence in response to arguments you know are misleading. And you sometimes shouldn't engage closed-mindedly, because to do so can be manipulative or ineffective. -/- In making this case, Jeremy Fantl discusses echo chambers and group polarization, the importance in academic writing of a sympathetic case for the opposition, the epistemology of disagreement, the account of open-mindedness, and invitations to problematic academic speakers. (shrink)

Practical wisdom is the intellectual virtue that enables a person to make reliably good decisions about how, all-things-considered, to live. As such, it is a lofty and important ideal to strive for. It is precisely this loftiness and importance that gives rise to important questions about wisdom: Can real people develop it? If so, how? What is the nature of wisdom as it manifests itself in real people? I argue that we can make headway answering these questions by modeling wisdom (...) on expert skill. Presenting the main argument for this expert skill model of wisdom is the focus of this paper. More specifically, I’ll argue that wisdom is primarily the same kind of epistemic achievement as expert decision-making skill in areas such as firefighting. Acknowledging this helps us see that, and how, real people can develop wisdom. It also helps to resolve philosophical debates about the nature of wisdom. For example, philosophers, including those who think virtue should be modeled on skills, disagree about the extent to which wise people make decisions using intuitions or principled deliberation and reflection. The expert skill model resolves this debate by showing that wisdom includes substantial intuitive and deliberative and reflective abilities. (shrink)

Wilfrid Sellars’s ethical theory was rich and deeply innovative. On Sellars’s view, moral judgments express a special kind of shared intention. Thus, we should see Sellars as an early advocate of an expressivism of plans and intentions, and an early theorist of collective intentionality. He supplemented this theory with a sophisticated logic of intentions, a robust theory of the categorical validity of normative expressions, a subtle way of reconciling the cognitive and motivating aspects of moral judgment, and much more— all (...) within a strict nominalism that preserves Sellars’s commitment to naturalism. The Ethics of Wilfrid Sellars offers the first systematic treatment of this sadly neglected aspect of Sellars’s work and demonstrates that his ethical theory— just like his more widely discussed epistemology— has much to contribute to current debates. (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)

The perception of reality by biosystems is based on different, and in certain respects more effective, principles than those utilized by the more formal procedures of science. As a result, what appears as random pattern to the scientific method can be meaningful pattern to a living organism. The existence of this complementary perception of reality makes possible in principle effective use by organisms of the direct interconnections between spatially separated objects shown to exist in the work of J. S. Bell.

In this paper, we offer a brief, critical survey of contemporary work on truth. We begin by reflecting on the distinction between substantivist and deflationary truth theories. We then turn to three new kinds of truth theory—Kevin Scharp's replacement theory, John MacFarlane's relativism, and the alethic pluralism pioneered by Michael Lynch and Crispin Wright. We argue that despite their considerable differences, these theories exhibit a common "pluralizing tendency" with respect to truth. In the final section, we look at the underinvestigated (...) interface between metaphysical and formal truth theories, pointing to several promising questions that arise here. (shrink)

The evidence is overwhelming that members of particularly wealthy and industry-owning segments of Western societies have much larger carbon footprints than most other humans, and thereby contribute far more than their “fair share” to the enormous problem of climate change. Nonetheless, in this paper we shall counsel against a strategy focused primarily on blaming and shaming and propose, instead, a change in the ethical conversation about climate change. We recommend a shift in the ethical framework from a focus on the (...) role of individual agents and a conversation about guilt; in its place, we propose a relational approach to public health ethics that is centered around the idea of relational solidarity. We begin by briefly reviewing the most common—and woefully inadequate—approach in the West to reducing emissions and responding to the health-related impacts of climate change. We then go on to propose a relational approach to public health ethics as an alternative ethical framework that better fits the moral problems associated with climate change and holds promise for a more meaningful response. (shrink)

Consider the sentence “Lois knows that Superman flies, but she doesn’t know that Clark flies”. In this paper we defend a Millian contextualist semantics for propositional attitude ascriptions, according to which ordinary uses of this sentence are true but involve a mid-sentence shift in context. Absent any constraints on the relevant parameters of context sensitivity, such a semantics would be untenable: it would undermine the good standing of systematic theorizing about the propositional attitudes, trivializing many of the central questions of (...) epistemology, the philosophy of mind, and the philosophy of action. In response to this problem, we prove a series of tenability results. We show that, given certain constraints on the parameters of context sensitivity, there is a broad class of principles of propositional attitude psychology whose good standing follows from corresponding claims about people’s mental representations. But these constraints also have some surprising consequences: they are jointly incompatible with coarse-grained theories of propositions, and they are in tension with a natural picture of how speakers and hearers coordinate on the interpretation of attitude ascriptions. In light of these consequences we explore different ways in which the contextualist picture might be developed, and argue that our preferred way compares favorably with Fregeanism and neo-Russellianism. (shrink)

The article begins by describing two longstanding problems associated with direct inference. One problem concerns the role of uninformative frequency statements in inferring probabilities by direct inference. A second problem concerns the role of frequency statements with gerrymandered reference classes. I show that past approaches to the problem associated with uninformative frequency statements yield the wrong conclusions in some cases. I propose a modification of Kyburg’s approach to the problem that yields the right conclusions. Past theories of direct inference have (...) postponed treatment of the problem associated with gerrymandered reference classes by appealing to an unexplicated notion of projectability . I address the lacuna in past theories by introducing criteria for being a relevant statistic . The prescription that only relevant statistics play a role in direct inference corresponds to the sort of projectability constraints envisioned by past theories. (shrink)

In a recent paper, Sylvia Wenmackers and Leon Horsten discuss how the concept of a fair infinite lottery can best be extended to denumerably infinite lotteries. Their paper uses and builds on the alpha-theory of Vieri Benci and Mauro Di Nasso. The purpose of this paper is to demonstrate a potential problem for alpha-theory.

This chapter addresses concerns that pragmatic encroachers are committed to problematic knowledge variance. It first replies to Charity Anderson and John Hawthorne’s new putative problem cases, which purport to show that pragmatic encroachment is committed to problematic variations in knowledge depending on what choices are available to the potential knower. It argues that the new cases do not provide any new reasons to be concerned about the pragmatic encroacher’s commitment to knowledge-variance. The chapter further argues that concerns about knowledge-variance are (...) not limited to the pragmatic encroacher, but come up for traditional purist invariantism as well. (shrink)

Homeostatic property clusters (HPCs) are offered as a way of understanding natural kinds, especially biological species. I review the HPC approach and then discuss an objection by Ereshefsky and Matthen, to the effect that an HPC qua cluster seems ill-fitted as a description of a polymorphic species. The standard response by champions of the HPC approach is to say that all members of a polymorphic species have things in common, namely dispositions or conditional properties. I argue that this response fails. (...) Instances of an HPC kind need not all be similar in their exhibited properties. Instead, HPCs should instead be understood as unified by the underlying causal mechanism that maintains them. The causal mechanism can both produce and explain some systematic differences between a kind’s members. An HPC kind is best understood not as a single cluster of properties maintained in stasis by causal forces, but as a complex of related property clusters kept in relation by an underlying causal process. This approach requires recognizing that taxonomic systems serve both explanatory and inductive purposes. (shrink)

Because it is unclear how a nonconscious stimulus is cognitively processed, there is uncertainty concerning variables that modulate the processing. In this context recent findings of a set of neuroimaging experiments are important. These findings suggest that conscious and nonconscious stimuli activate same areas of the brain during performance of a similar task. Further, different areas are activated when a task is performed with or without awareness of processing. It appears that the neural network involved in cognitive processing depends on (...) the awareness of processing rather than awareness of perception. Since conscious and nonconscious cognitive processing use separate neural networks, each processing is modulated by different variables. Attention modulates most conscious cognitive processing and most, but not all, nonconscious processing is attention dependent. Nonconscious tasks that require attentional resources, with or without conscious awareness, are processed using the attention dependent system. Further, because attention dependent and attention independent tasks are processed by separate neural networks, the cognitive processing and modulating variables can be understood better if cognitive tasks are defined as attention dependent or attention independent, rather than conscious or nonconscious. (shrink)

What explains why we are subjects for whom objects can have value, and what explains which objects have value for us? Axiologicians say that the value of humanity is the answer. I argue that our value, no matter what it is like, cannot perform this task. We are animals among others. An explanation of the value of objects for us must fit into an explanation of the value of objects for animals generally. Different objects have value for different animals. Those (...) differences depend on differences in animal natures and, in particular, on the diverse characteristic capacities of different animals. Once we invoke animal natures, there is nothing for the value of animality, including the value of humanity, to explain. (shrink)

Dombrowski and Murdoch offer versions of the ontological argument which aim to avoid two types of objection – those concerned with the nature of the divine, and those concerned with the move from an abstract concept to a mind-independent reality. For both, the nature of the concept of God/Good entails its instantiation, and both supply a supporting argument from experience. It is only Murdoch who successfully negotiates the transition from an abstract concept to the instantiation of that concept, however, and (...) this is achieved by means of an ontological argument from moral experience which, in a reversal of the Kantian doctrine, depends ultimately on a form of the cosmological argument. (shrink)

Given the importance of theoretical wisdom in Aristotle’s account of the human good, it is striking that contemporary virtue ethicists have been virtually silent about this intellectual virtue and what contribution it makes – or could make – toward human flourishing. In this paper, I examine, and respond to, two main worries that account for theoretical wisdom’s current marginality. Along the way, I sketch a neo-Aristotelian conception of theoretical wisdom, and argue that this intellectual virtue is more central to the (...) concerns of contemporary virtue ethicists than it has perhaps so far seemed. (shrink)

Plato is often acknowledged as the first philosophical critic of democracy and his Republic is regularly taken as a paradigm of an anti-democratic work. While it is true that Plato objected to much about the democracy of his own time, Plato’s political theorizing also reveals an interest in improving democratic institutions. This chapter explores three themes in Plato’s thinking about democracy: firstly, Plato's insistence that rulers should be knowledgeable and his claim that most people are politically incompetent (§1); secondly, Plato's (...) criticisms of oratory and the corrupting effects of public rhetoric (§2); thirdly, Plato's use of democratic institutions in the Laws (§3). Once we appreciate these different evaluations of democratic practices, we can see that Plato was not simply ‘anti-democratic’ or ‘pro-democratic’ but thought some democratic practices should be abandoned, some reformed, and some adopted. (shrink)

The purpose of this paper is to dissolve paradoxes of the infinite by correctly identifying the infinite natural numbers.