Charbel Niño El-Hani

A síndrome de Down e sua patogênese: considerações sobre o determinismo genético

The analysis of causal factors for Down syndrome and its pathogenesis allows, beyond the analysis itself, a review of the natural history of the syndrome and the effects of the trisomy of 21q22 chromosome band which has been considered critical for the development of the disorder. Although there is always a chromosome imbalance in Down syndrome patients, the relevance of the genetic determinism can be questioned since DS subjects cognitive potential can be better developed through theearly intervention of neuro-motor and psycho-educational programs.

On some theoretical grounds for an organism-centered biology: Property emergence, supervenience, and downward causation

In this paper, we investigate some theoretical grounds for bridging the gap between an organism-centered biology and the chemical basis of biological explanation, as expressed in the prevailing molecular perspective in biological research. First, we present a brief survey of the role of the organism concept in biological thought. We advance the claim that emergentism (with its fundamental tenets: ontological physicalism, qualitative novelty, property emergence, theory of levels, irreducibility of the emergents, and downward causation) can provide a metaphysical basis for a coherent sort of organicism. Downward causation (DC) is the key notion in emergentist philosophy, as shown by the tension between the aspects of dependence and nonreducibility in the concept of supervenience, preferred by many philosophers to emergence as a basis for nonreductive physicalism. As supervenience physicalism does not lead, arguably, to a stable nonreductive physicalist account, we maintain that a philosophical alternative worthy of investigation is that of a combination of supervenience and property emergence in the formulation of such a stance. Taking as a starting-point O’Connor’s definition of an emergent property, we discuss how a particular interpretation of downward causation (medium DC), inspired by Aristotelian causal modes, results in an explanation of property emergence compatible with both physicalism and non-reductionism. In this account of emergence, one may claim that biology, as a science of living organization, is and remains a science of the organism, even if completely explained by the laws of chemistry. We conclude the paper with a new definition of an emergent property.

Evidence against a Relationship between Dermatoglyphic Asymmetry and Male Sexual Orientation

Hall and Kimura (1994) studied the relation between dermatoglyphic asymmetry and male sexual orientation in a sample of 66 homosexual and 182 heterosexual men. They found that more homosexual men possessed a leftward dermatoglyphic asymmetry than did heterosexual men. In this paper, we report a comparative study about the relationship between sexual orientation and dermatoglyphic characteristics, including 60 homosexual men, 76 heterosexual men, and 60 heterosexual women, recruited from the general population, and also from a gay-rights nongovernmental organization, in Salvador, Brazil. Ulnar loops were the most frequent dermatoglyphic pattern in all groups, followed by whorls, arches, and radial loops. A chi-square analysis comparing the frequencies of the patterns in the three groups only showed an excess of ulnar loops in women (p < 0.05) and arches in men (p < 0.01), but did not reveal significant differences between homosexuals and the other groups studied. There was no significant difference between gay and straight men on total ridge count. We found a preponderance of rightward asymmetry in homosexual and heterosexual men, as well as in heterosexual women. Our results do not agree with Hall and Kimuras data indicating that more gay men possessed the minority leftward asymmetry than did straight men. There was no significant difference in leftward asymmetry in the sample studied. The results reported in this paper do not support any relation between dermatoglyphic asymmetry and male sexual orientation, and, thus, any hypothesis concerning a biological intrauterine contribution to adult sexual orientation somehow associated with dermatoglyphic development.

Livros didáticos de Biologia do Ensino Médio: resultados do PNLEM/2007

RESUMO:Em 2005, os livros didaticos de Biologia do ensino medio publicados no Brasilforam avaliados, como parte do Programa Nacional do Livro para o Ensino Medio(PNLEM). Neste artigo, relatamos resultados dessa avaliacao. Os criterios e o processo deavaliacao sao apresentados de modo detalhado, bem como os principais problemas dasobras nao-recomendadas para compra pelo MEC e os principais aspectos positivos dasobras recomendadas. Das 18 obras submetidas a avaliacao, nove satisfizeram os criteriosminimos de qualidade para aprovacao. Sete obras didaticas excluidas apresentaram proble-mas em todas as classes de criterios de avaliacao. Todas as nove obras excluidas exibiramproblemas relativos a correcao e adequacao conceituais, e a precisao da informacao basicafornecida. As qualidades mais frequentes nas obras recomendadas diziam respeito a ade-quacao metodologica e a construcao do conhecimento. Nao encontramos evidencias cla-ras de que a frequencia de escolha pelos professores do ensino medio refletiu a qualidadedos itens avaliados, conforme estabelecida pela equipe que analisou as obras.Palavras-chave:Livros Didaticos; Ensino de Biologia; Ensino Medio; PNLEM.