Las micotoxinas son metabolitos fúngicos secunda­rios que pueden ejercer un efecto tóxico tanto en el hombre como en los animales debido, principalmente, a su exposición a través de los alimentos. La presencia de estos compuestos ha sido demostrada en una amplia variedad de materias primas, alimentos y piensos, en los que lo habitual es encontrar de for­ma frecuente una contaminación múltiple por diferentes mico­toxinas, en pequeñas cantidades, lo que puede generar efectos tóxicos subcrónicos, así como bioacumulación. Este artículo revisa los (...) principales elementos que configuran la problemática de las micotoxinas para el hombre y los animales, y aborda los retos de futuro que se plantean en el estudio de las micotoxinas, entre los que destacan el efecto que el cambio climático puede tener sobre el patrón de contaminación por micotoxinas en los alimentos, el descubrimiento creciente de nuevas micotoxinas en formas modificadas, la evaluación de la coexistencia de estas to­xinas y otros contaminantes, y las formas para detectar e intentar eliminar estos compuestos tóxicos de los alimentos. (shrink)

Recent works about ecumenical systems, where connectives from classical and intuitionistic logics can co-exist in peace, warmed the discussion on proof systems for combining logics. This discussion has been extended to alethic modalities using Simpson’s meta-logical characterization: necessity is independent of the viewer, while possibility can be either intuitionistic or classical. In this work, we propose a pure, label free calculus for ecumenical modalities, nEK\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathsf {nEK}$$\end{document}, where exactly one logical operator figures (...) in introduction rules and every basic object of the calculus can be read as a formula in the language of the ecumenical modal logic EK\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathsf {EK}$$\end{document}. We prove that nEK\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathsf {nEK}$$\end{document} is sound and complete w.r.t. the ecumenical birelational semantics and discuss fragments and extensions. (shrink)

The acoel worm Symsagittifera roscoffensis, an early offshoot of the Bilateria and the only well‐studied marine acoel that lives in a photosymbiotic relationship, exhibits a centralized nervous system, brain regeneration, and a wide repertoire of complex behaviors such as circatidal rhythmicity, photo/geotaxis, and social interactions. While this animal can be collected by the thousands and is studied historically, significant progress is made over the last decade to develop it as an emerging marine model. The authors here present the feasibility of (...) culturing it in the laboratory and describe the progress made on different areas, including genomic and tissue architectures, highlighting the associated challenges. In light of these developments, and on the ability to access abundant synchronized embryos, the authors put forward S. roscoffensis as a marine system to revisit questions in the areas of photosymbiosis, regeneration, chronobiology, and the study of complex behaviors from a molecular and evolutionary perspective. (shrink)

Normal 0 21 false false false ES-CO X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} This article explores Ludwik Fleck’s concepts of collective thinking, style of thinking, esoteric and exoteric communication as precursors of the concepts of paradigm and incommensurability central in Thomas Kuhn’s thought.

_Higher Education and the Color Line_ examines the role of higher education in opening up equal opportunity for mobility in American society--or in reinforcing the segregation between white and nonwhite America. In the wake of the U.S. Supreme Court's landmark decision upholding affirmative action, this comprehensive and timely book outlines the agenda for achieving racial justice in higher education in the next generation. Weaving together current research and a discussion of overarching demographic, legal, and political issues, the book focuses on (...) the racial transformation of higher education and the structural barriers that perpetuate racial stratification at the postsecondary level. _Higher Education and the Color Line_ includes chapters that outline the demographic changes in elementary, secondary, and postsecondary school enrollment; the evolving role of law and policy; the barriers faced by minority college students; and the kinds of programs that best serve them. Topics addressed include financial aid; the role of community colleges; nontraditional paths to postsecondary education; and the role of higher education in social and economic mobility. In addition to providing a thorough and up-to-date assessment of the state of racial integration in higher education, the book goes beyond the usual black-and-white analysis to provide a multiethnic perspective supported by extensive new data. Taken together, these discussions examine the role of higher education in opening up equal opportunity for mobility in American society--or in reinforcing the segregation between white and nonwhite America. It provides insight for how institutions, states, and the country should be thinking about U.S. Supreme Court Justice Sandra Day O’Connor’s hope that affirmative action will no longer be needed in 25 years. (shrink)

En este trabajo se define formamente el concepto de representacion en química utilizando homomorfismos desde estructuras algebraicas, que llamamos sistemas de tipo C, en otras estructuras especiales de símbolos muy relacionados con los que son habituales en la qímica experimental. Para la definicion de los sistemas de tipo C se ha seleccionado un conjunto minimo de relaciones y funciones, que son necesarias para expresar proposiciones significativas en química. Tambien se define un lenguaje formal de primer orden adecuado a los sistemas (...) de tipo C, que llamamos L(C). EI resultado principal que se demuestra es que toda representación que verifica las mismas sentencias de L(C) que un sistema de tipo C, es necesariamente isomorfo a él. Se concluye por lo tanto que puede existir un problema linguístico subyacente en la aplicacion que de la mecaníca cuántica se hace en la química teórica.The concept of representation in chemistry bas been formallv defined by means of homomorphisms from algebraical structures, which we call type-C systems, to some special sets of symbols which can be related to the symbols ordinarily used in experimental chemistry. A minimum number of relations and functions, which would suffice to express significant propositions in chemistry, have been chosen to define type-C systems. A first order formal language L(C) adequate to type-C systems has been defined. It has been shown that each representation that verifies the same sentences of L(C) as a type-C system is necessarily isomorphic to it. It is concluded that a systematic study of the representation problem in chemistry is in order because a deep language problem underlies the application of quantum mechanies to chemical problems. (shrink)

This article presents counter evidence against Smolensky's theory that human intuitive/nonconscious congnitive processes can only be accurately explained in terms of subsymbolic computations carried out in artificial neural networks. We presentsymboliclearning models of two well‐studied, complicated cognitive tasks involving nonconscious acquisition of information: learning production rules and artificial finite state grammars. Our results demonstrate that intuitive learning does not imply subsymbolic computation, and that the already well‐established, perceived correlation between “conscious” and “symbolic” on the one hand, and between “nonconscious” and (...) “subsymbolic” on the other, does not exist. (shrink)

Prior research has found attributions to mediate the relationship between the elements of corporate social responsibility activities and consumer responses to firms; however, the question of what variables determine consumer attributions of CSR remains partially unaddressed. This article analyzes why consumers make attributions of CSR that are either positive, or negative. The results obtained from two empirical studies indicate that company–cause fit, corporate ability, and interpersonal trust have a positive influence on the motives that consumers attribute to CSR, whereas corporate (...) hypocrisy has a negative effect. This research contributes to our understanding of the psychological mechanisms underlying impactful consumer judgments and provides guidance for organizations in responding to such evaluations. (shrink)

Resenha de Frans de Waal. The Age of Empathy: Nature's Lessons for a Kinder Society. London: Souvenir Press, Paperback Edition, 2011.

Comparing mortuary rituals across 57 representative cultures extracted from the Human Relations Area Files, this paper demonstrates that kin of the deceased engage in behaviours to prepare the deceased for disposal that entail close and often prolonged contact with the contaminating corpse. At first glance, such practices are costly and lack obvious payoffs. Building on prior functionalist approaches, we present an explanation of corpse treatment that takes account of the unique adaptive challenges entailed by the death of a loved one. (...) We propose that intimate contact with the corpse provides the bereaved with extensive veridical cues of death, thereby facilitating acceleration of a grieving process that serves to recategorize the deceased as no longer a relationship partner, opening the door to relationship replacement and a return to social functioning. The benefits of exposure to such cues are tempered by the costs of exposure to cues of disease risk, a balance that in part explains the relative rarity of highly invasive mortuary practices that exacerbate the latter factor. We conclude by discussing implications of our model for contemporary mortuary practices in the developed world. (shrink)

This study aimed to adapt the Flourishing Scale to a Chilean high school context and provide evidence of its validity. Data were collected from 1,348 students from three different Chilean schools. The results of confirmatory factor analysis supported a one–factor solution, multiple–group CFA supported gender invariance, and structural equation model indicated that the FS is related to positive and negative academic feelings. Overall, the evidence indicates that the Flourishing Scale adapted to the high school context is an instrument that produces (...) valid and reliable scores in our high school Chilean sample. (shrink)

I) La metafísica de la evidencia, cuya más conspicua expresión es la mathesis universalis cartesiana, busca lo apremiante y necesario, el fundamento o fondo de las cosas, el cual se entiende independiente de la forma y alcanzable por un pensamiento sin supuestos: la retórica es la prescindible qualitas de la filosofía. II) La de Vico, por contra, puede considerarse como una retorsión de esa postura filosófica: al contribuir a desvelar sus supuestos ocultos, los niega. III) La tropología viquiana, al proponer (...) la univocidad de los tropos, hace de la filosofía retórica y de la retórica filosofía: la retórica es la imprescindible quidditas de la filosofía. (shrink)

Estudio bibliográfico de / A bibliographical study of: New Vico Studies, 9, 1991.

Estudio bibliográfico crítico de: / A Bibliographical and Critical Study of: New Vico Studies, XII, 1994; G. Vico, The Art of Rhetoric, G.A. Pinton & A.W. Shippee trans. - eds., Rodopi, Amsterdam - Atlanta, 1996.

Se plantea el problema de la influencia de Suárez en la concepción de la individualidad por Leibniz. Para ello se analiza principalmente la Disputatio Metaphysica de principio individui de Leibniz. Se diferencian tres posturas: tomista, scotista y suareziana. Se confronta la idea de ‘forma’ de Leibniz con la de Aristóteles y la idea de ‘forma sustancial’ con la escolástica y Suárez. La comparación de Leibniz con Suárez se centra en la noción clave de “forma sustancial” y se analizan sus diversos (...) significados. Se formula la coincidencia de ambos autores en torno a la tesis de que la individuación tiene lugar en virtud de la “entidad total”. Finalmente se analiza el significado exacto de esta expresión y se señalan las diferencias entre ambos autores, especialmente las que se producen en la evolución final de Leibniz. Ahí se introduce la concepción de la forma sustancial como principio vital que cohesiona los cuerpos. (shrink)

Este trabajo se centra en el papel de la gestisn de la superacisn de los directivos universitarios y el reto que significa para las universidades latinoamericanas. Desde una perspectiva ciencia- tecnologma y sociedad se pretende determinar las condiciones sociales en que se sustenta la necesidad de elaboracisn de un modelo de superacisn en la gestisn acadimica de los directivos para perfeccionar el proceso formativo de la Escuela Superior Politicnica de Manabm "Manuel Filix Lspez", en Ecuador. A partir de un diagnsstico (...) realizado previamente en esa universidad se identificaron limitaciones en el modelo de gestisn de superacisn actual, que demandan el diseqo e implementacisn de un modelo, ajustado a las necesidades sociales concretas de ese centro de educacisn superior. The role of negotiation in order to improve the level of the principal staff in higher education is the main objective of this research. This work was carried out through a scientific and technologic point of view based on a creative model which develop a formative process at Manuel Filix Lspez" polytechical school in Ecuador. A diagnosis revealed the necessity of implementing a model according to the real needs in higher education. (shrink)

O comportamento de apego se expressa em adultos quando estes se encontram em situações que envolvam medo, mudança ou conflito, como em casos de perda. O objetivo do presente estudo foi investigar os comportamentos de apego adulto frente à perda repentina de um ente querido. Participaram cinco adulto..

Humans and some animal species are able to learn stimulus-response associations by observing others' behavior. It saves energy and time and avoids the danger of trying the wrong actions. Observational learning depends on the capability of mapping the actions of others into our own behaviors, processing outcomes, and combining this knowledge to serve our goals. Observational learning plays a central role in the learning of social skills, cultural knowledge, and tool use. Thus, it is one of the fundamental processes in (...) which infants learn about and from adults. In this paper, we review current methodological approaches employed in observational learning research. We highlight the important role of the prefrontal cortex and cognitive flexibility to support this learning process, develop a new neural working model of observational learning, illustrate how imitation relates to observational learning, and provide directions for future research. (shrink)

O processo de resposta do Teste Pictórico de Memória (TEPIC-M) classifica seus itens em três categorias sequenciais (céu, terra e água). Assim, aventou-se a hipótese que pessoas com uma familiaridade diária com o mar (Aracaju-grupo A) lembrariam mais desses itens quando comparadas com pessoas sem es..

1. Dimensiunea românească a existenței.

Filosofía e Historia dormían en la placidez uterina del mito, cuando quizá el hecho del principio era el principio del hecho, donde acaso no era consciente la distinción entre el origen cronológico y el origen lógico. Pero Filosofía e Historia despertaron y, no acordándose de su matricial maridaje, acordaron mutuamente su divorcio. Tal vez fuera la querella entre Ilustración y Romanticismo la expresión "ideal" de esa escisión efectiva entre lo racional y lo histórico. No obstante, la propia conciencia histórica de (...) la separación aportó justamente la posibilidad de su superación: la "conciencia histórica" misma. Y ése era el requisito necesario para una Filosofía de la Historia. La Scienza Nuova lo cumple porque, contando cómo efectivamente se reúnen Filosofía y Filología, relata idealmente la supresión del enfrentamiento ilustrado-romántico. Vico aporta una conciencia histórica que narra una nueva racionalidad, una modificación de la mente en que haciendo de la razón Historia y de la Historia razón se le restituye al mito su condición histórica y racional, a la par que Filosofía e Historia recuperan su mítica originalidad. (shrink)

Así como Vico comprendió primero que nadie y como nadie la contemporaneidad del mito defendiendo que, lejos de estar en conflicto con la razón, es el instrumento originario con el que escapar a la soledad del hombre frente a una naturaleza muda de sentido, Hans Blumenberg ha sido en nuestro tiempo el mayor defensor de la racionalidad del mito, y con argumentos, a juicio del autor, muy semejantes a los de Vico. El "absolutismo de la realidad", la "metáfora absoluta" y (...) el "principio de razón insuficiente", los tres elementos centrales, según la presente lectura, de la obra de Blumenberg, compartirían con Vico una misma sensibilidad metafórica. (shrink)

This is a collection of twenty-two essays by an eminent philosopher, critic, and theorist that appeared between 1971 and 1992.

Human beings inhabit a symbolic reality that articulates meaning. This is culture understood as a web of meanings that actually builds our identity by providing guidance in the complexity of our environment. It is the complex interplay between identity and alterity, between interiority and exteriority, between familiarity and strangeness. Worldviews set up borders that delimit one's own world and others' ground by establishing stereotypes and prejudices. This article presents the results of a research project on prejudices towards the other in (...) students majoring in Education and Psychology with the aim of offering some reflections on what is at stake in social exclusion policies. (shrink)