Carbon monoxide (CO), a product of organic oxidation processes, arises in vivo during cellular metabolism, most notably heme degradation. CO binds to the heme iron of most hemoproteins. Tissue hypoxia following hemoglobin saturation represents a principle cause of CO‐induced mortality in higher organisms, though cellular targets cannot be excluded. Despite extreme toxicity at high concentrations, low concentrations of CO can confer cytoprotection during ischemia/reperfusion or inflammation‐induced tissue injury. Likewise, heme oxygenase, an enzyme that produces CO, biliverdin and iron, as well (...) as a secondary increase in ferritin synthesis, from the oxidation of heme, can confer protection in vivo and in vitro. CO has been shown to affect several intracellular signaling pathways, including guanylate cyclase, which generates guanosine 3′:5′ cyclic monophosphate and the mitogen‐activated protein kinases (MAPK). Such pathways mediate, in part, the known vasoregulatory, anti‐inflammatory, anti‐apoptotic and anti‐proliferative effects of this gas. Exogenous CO delivered at low concentrations is showing therapeutic potential as an anti‐inflammatory agent and as such can modulate numerous pathophysiological states. This review will delve into the biological significance and medical applications of this gas molecule. BioEssays 26:270–280, 2004. © 2004 Wiley Periodicals, Inc. (shrink)

Boyer suggests that laws cannot account for ownership intuitions, but there may be situations when intuitions hew to laws almost perfectly. Laws granting governments taxation powers provide an interesting case study. We report data here suggesting that people's intuitions track law very closely, and are unaffected by manipulating a P() tag input. We propose two hypotheses to explain this finding.

By constructing a maximal incomplete d.r.e. degree, the nondensity of the partial order of the d.r.e. degrees is established. An easy modification yields the nondensity of the n-r.e. degrees and of the ω-r.e. degrees.

Resumo: Este artigo se inicia discutindo um tema relativamente clássico na epistemologia, qual seja, analogia, conceito e teoria, explorando uma perspectiva contemporânea do fazer científico e, em alguma medida, da filosofia. A partir daí, busca reacender o debate, sempre necessário, sobre teoria, analogia e conceito, à luz da produção do conhecimento científico, destacando abordagens supradisciplinares e transparadigmáticas. Para tanto, socorre-se de diferentes áreas do conhecimento científico, a sociologia clássica e contemporânea, elementos da biologia, aspectos da cibernética, para demostrar que a (...) ciência, de modo geral, considerando suas múltiplas disciplinas, intercambia de forma cada vez mais dinâmica raciocínios analógicos, com vistas a dar conta da crescente complexidade em que se encontra.: This paper begins by discussing a classical theme in epistemology, namely analogy, concept, and theory using. It explores a contemporary perspective on scientific practies, Including some aspects of philosophical thinking. So it seeks to rekindle the always necessary debate on theory, analogy and concept about scientific production based on supradisciplinary and transparadigmatic approaches. In order to do so, we draw from different areas of scientific knowledge, classical and contemporary sociology, elements of biology, aspects of cybernetics, in order to demonstrate that science, considering its multiple disciplines, increasingly exchanges analogical reasoning. This is done to account for the growing complexity of current scientific knowledge. (shrink)

Hugh Lacey (1939) é pesquisador emérito na Swarthmore College, Pennsylvania, Estados Unidos, onde começou a lecionar em 1972. É Doutor em História e Filosofia da Ciência pela Universidade de Indiana (EUA), tendosido professor visitante na Universidade de São Paulo em diversas ocasiões (1973, 1996, 2000 e 2004). Seus trabalhos atribuem lugares próprios aos valores dentro da tecnociência, procurando mostrar que a abordagem científica materialista precisa assumir também o lugar que as coisas ocupam em sistemas ecológicos e sociais. Lacey é autor (...) de diversos artigos e livros, entre os quais estão Valores e Atividade Científica 1, Valores e Atividade Científica 2, A Controvérsia sobre os transgênicos: questões científicas e éticas, entre outros. (shrink)

Léo Coutellec propose dans cet ouvrage de construire un espace de réflexion critique sur ce qu’il nomme la science impliquée. Nom d’une science qui prend acte de sa responsabilité, attentive aux conséquences, une science qui ouvre la possibilité d’un questionnement sur ses finalités, qui ne revendique plus sa neutralité axiologique pour affirmer son objectivité, la science impliquée vise au partage des savoirs et des pouvoirs liés à ces savoirs. Pour l’auteur, l’enjeu est de doter la science d’un nouveau principe démocratique (...) qui permettrait, non pas de la sortir de la tourmente sociétale dans laquelle elle semble être prise, mais de la penser au pluriel dans la profondeur de son implication radicale au réel. Sa réflexion épistémologique sur les sciences rejoint celle de l’éthique. Issu d’une conférence donnée à l’occasion du 20e anniversaire du groupe Sciences en questions, ce petit ouvrage renouvelle les réflexions épistémologiques et philosophiques au sein de la démarche scientifique et notre façon de penser la responsabilité dans les sciences. (shrink)

Em 'Saber de e saber que' o autor penetra no terreno da Lógica Simbólica, percorrendo algumas trilhas da Filosofia da Ciência. A obra traz um "mix" de Teoria do Conhecimento, Lógica, Filosofia da Linguagem e Metodologia da Ciência. Segundo o autor, O 'Saber de' corresponde aos primeiros conhecimentos gerados pelos objetos que envolvem as pessoas, provocando um 'ajuste intelectual' que posteriormente necessitará de um 'Saber como' agir com a utilização da razão, visando satisfazer os desejos humanos.Finalmente o 'Saber que' leva (...) a fazer interferências, que com o auxílio da lógica, permite chegar à 'sabedoria'. (shrink)

This article explores the changing relationships between geometric and arithmetic ideas in medieval Europe mathematics, as reflected via the propositions of Book II of Euclid’s Elements. Of particular interest is the way in which some medieval treatises organically incorporated into the body of arithmetic results that were formulated in Book II and originally conceived in a purely geometric context. Eventually, in the Campanus version of the Elements these results were reincorporated into the arithmetic books of the Euclidean treatise. Thus, while (...) most of the Latin versions of the Elements had duly preserved the purely geometric spirit of Euclid’s original, the specific text that played the most prominent role in the initial passage of the Elements from manuscript to print—i.e., Campanus’ version—followed a different approach. On the one hand, Book II itself continued to appear there as a purely geometric text. On the other hand, the first ten results of Book II could now be seen also as possiblytranslatable into arithmetic, and in many cases even as inseparably associated with their arithmetic representation. (shrink)

This paper responds to two aspects of Ralph Johnson's Manifest Rationality (2000). The first is his critique of deductivism. The second is his failure to make room for some species of argument (e.g., visual and kisceral arguments) proposed by recent commentators. In the first case, Johnson holds that argumentation theorists have adopted a notion of argument which is too narrow. In the second, that they have adopted one which is too broad. I discuss the case Johnson makes for both claims, (...) and possible objections to his analysis. (shrink)

We announce and explain recent results on the computably enumerable (c.e.) sets, especially their definability properties (as sets in the spirit of Cantor), their automorphisms (in the spirit of Felix Klein's Erlanger Programm), their dynamic properties, expressed in terms of how quickly elements enter them relative to elements entering other sets, and the Martin Invariance Conjecture on their Turing degrees, i.e., their information content with respect to relative computability (Turing reducibility).

Este libro es una recopilación de artículos, ponencias y conversaciones -casi todos provenientes del Seminario de Problemas Científicos y Filosóficos de la UNAM- y conforman un diálogo, que recuerda el intercambio epistolar, entre dos figuras destacadas dentro de la filosofía de la ciencia en México. Los textos se han ordenado cronológicamente y están escritos en un tono informal; el objetivo es introducir al lector en los temas actuales de la filosofía de la ciencia desde dos enfoques distintos, el ético y (...) el epistemológico. (shrink)

Post in 1944 began studying properties of a computably enumerable set A such as simple, h-simple, and hh-simple, with the intent of finding a property guaranteeing incompleteness of A . From the observations of Post and Myhill , attention focused by the 1950s on properties definable in the inclusion ordering of c.e. subsets of ω, namely E = . In the 1950s and 1960s Tennenbaum, Martin, Yates, Sacks, Lachlan, Shoenfield and others produced a number of elegant results relating ∄-definable properties (...) of A , like maximal, hh-simple, atomless, to the information content of A . Harrington and Soare gave an answer to Post's program for definable properties by producing an ∄-definable property Q which guarantees that A is incomplete and noncomputable, but developed a new Δ 3 0 -automorphism method to prove certain other properties are not ∄-definable. In this paper we introduce new ∄-definable properties relating the ∄-structure of A to deg, which answer some open questions. In contrast to Q we exhibit here an ∄-definable property T which allows such a rapid flow of elements into A that A must be complete even though A may possess many other properties such as being promptly simple. We also present a related property NL which has a slower flow but fast enough to guarantee that A is not low, even though A may possess virtually all other related lowness properties and A may simultaneously be promptly simple. (shrink)

Este artigo parte de uma proposta terapêutica psicanalítica de cura pela fala e das premissas dos estudos a respeito de um performativo para conjurar referenciais e tecer considerações acerca do feitiço, tomando-o na sua dimensão de acontecimento singular e de natureza imprevisível. Esta discussão ocorrerá debruçada sobre os meios de um capitalismo e pautada a partir das ambivalências de uma ideia de fetiche. No ensejo desta discussão, são retomadas algumas colocações que elaboram sobre os interstícios entre magia e política para (...) indicar a importância de uma dimensão incapturável no fazer científico. (shrink)

By constructing a maximal incomplete d.r.e. degree, the nondensity of the partial order of the d.r.e. degrees is established. An easy modification yields the nondensity of the n-r.e. degrees and of the ω-r.e. degrees.