O estudo dos fatos e episódios científicos é importante no sentido de possibilitar a compreensão do desenvolvimento das Ciências em contextos tanto do ensino, em diversos níveis, quanto da pesquisa. No entanto, a leitura dessa construção histórica precisa considerar visões de Ciência que superem as perspectivas lineares e neutras sobre a construção do processo de produção científica. Sob tal perspectiva, propõe-se nesse artigo uma releitura do movimento de elaboração do modelo da dupla hélice do DNA a partir do (...) aporte epistemológico de Thomas Kuhn. Entendemos ser este um contexto importante que permeia a formação científica, tanto na educação básica quanto no ensino superior, no campo das Ciências Biológicas e que os conceitos desenvolvidos a partir da elaboração do modelo da dupla hélice são basilares para a compreensão de conhecimentos relacionados à genética, citologia, evolução, dentre outros. No processo de revisitar esse recorte histórico, identificamos os embates teóricos entre pesquisadores de diversos campos, a competição e o consenso como elementos que mobilizam a busca de respostas na concretização de um novo paradigma. Dessa forma, a dinamicidade da Ciência se mostra presente rejeitando a ideia do dado pronto e valorizando o processo no qual o conhecimento se constrói. Propomos que este seja um exercício de reflexão considerando-se que revisitar a história da Ciência a partir de diferentes perspectivas epistemológicas pode propiciar aos sujeitos novos olhares em um devir que descortine conceitos construídos de maneira dinâmica por homens e mulheres que, entre ires e vires, dão significado aos fenômenos que nos rodeiam. Palavras-chave: DNA, Thomas Kuhn, ciência normal, revolução científica. (shrink)

O presente artigo objetiva realizar um estudo de caso que aplica o modelo de inferência da melhor explicação (inference to the best explanation, IBE) de Peter Lipton ao episódio histórico da construção do modelo de dupla-hélice do DNA, no século XX. Procura avaliar a eficiência de tal modelo quando confrontado com a história da ciência e em que medida é capaz de rivalizar com ou superar outros modelos de explicação já consolidados na literatura de filosofia da ciência, tais (...) como os modelos nomológico-dedutivo e indutivo-estatístico de Carl Hempel, o modelo de relevância estatística de Wesley Salmon, ou, ainda, o modelo pragmático de explicação de Bas van Fraassen. Por fim, a conclusão apresentada é que o modelo de inferência da melhor explicação se mostra mais eficaz para ilustrar esse episódio da história da genética do que as outras propostas filosóficas analisadas. (shrink)

In this paper, I discuss the discovery of the DNA structure by Francis Crick and James Watson, which has provoked a large historical literature but has yet not found entry into philosophical debates. I want to redress this imbalance. In contrast to the available historical literature, a strong emphasis will be placed upon analysing the roles played by theory, model, and evidence and the relationship between them. In particular, I am going to discuss not only Crick and Watson's well-known model (...) and Franklin's x-ray diffraction pictures (the evidence) but also the less well known theory of helical diffraction, which was absolutely crucial to Crick and Watson's discovery. The insights into this groundbreaking historical episode will have consequences for the ‘new’ received view of scientific models and their function and relationship to theory and world. The received view, dominated by works by Cartwright and Morgan and Morrison ([1999]), rather than trying to put forth a ‘theory of models’, is interested in questions to do with (i) the function of models in scientific practice and (ii) the construction of models. In regard to (i), the received view locates the model (as an idealized, simplified version of the real system under investigation) between theory and the world and sees the model as allowing the application of the former to the latter. As to (ii) Cartwright has argued for a phenomenologically driven view and Morgan and Morrison ([1999]) for the ‘autonomy’ of models in the construction process: models are determined neither by theory nor by the world. The present case study of the discovery of the DNA structure strongly challenges both (i) and (ii). In contrast to claim (i) of the received view, it was not Crick and Watson's model but rather the helical diffraction theory which served a mediating purpose between the model and the x-ray diffraction pictures. In particular, Cartwright's take on (ii) is refuted by a comparison of Franklin's bottom-up approach with Crick and Watson's top-down approach in constructing the model. The former led to difficulties, which only a strong confidence in the structure incorporated in the model could circumvent. How to Get to the Structure 1.1 X-ray diffraction and its synthesis 1.2 Model building and Pauling's panache 1.3 The structure of proteins 1.3.1 A failed inference to the best explanation 1.3.2 The misleading 5.1 Å spot in proteins and how to get rid of it 1.3.3 Derived predictions from Pauling's alpha-helix of protein molecules The CCV Theory of Helical X-Ray Diffraction 2.1 The role of the CCV theory in the discovery of the DNA structure Killing the Helix 3.1 Appreciating all evidence—in vain Conclusion Epilogue: Chargaff's Ratios CiteULike Connotea Del.icio.us What's this? (shrink)

Habermas se ha valido a menudo de la expresión "sociedad postsecular" para referirse al proceso de aprendizaje mutuo entre la razón ilustrada y la conciencia religiosa en el seno de las sociedades modernas. Esa expresión es utilizada por el pensador alemán en dos acepciones distintas. Unas veces la emplea como categoría sociológica descriptiva y otras como categoría filosófica de carácter normativo. En este trabajo rechazamos el uso descriptivo del concepto de sociedad postsecular, haciéndonos eco de las críticas que contra él (...) se han vertido desde la sociología de la religión contemporánea. A la vez, reconocemos el interés que reviste la propuesta normativa de Habermas. Tras exponer el sentido preciso de esa propuesta, examinamos la principal acusación que contra ella cabe formular: la de funcionalismo religioso. (shrink)

En los últimos tiempos, destacadas figuras del horizonte filosófico y teológico español se han declarado partidarias de lo que ha dado en llamarse ética civil. El propósito de este trabajo es exponer las razones por las que no puedo compartir la postura de mis distinguidos colegas. El estudio de algunos de sus textos -que serán citados abundantemente en lo que sigue- me ha empujado a la conclusión de que bajo el nombre de ética civil circulan confundidas dos propuestas morales diferentes, (...) a las que llamare concepción estática y concepción dinámica de la ética civil, respectivamente. Y no se trata, según creo, de dos teorías complementarias (de suerte que pudieran combinarse en una unidad teórica superior), sino de dos teorías incompatibles. Por si esta ambigüedad fuera poco, hay razones para pensar que ambas son inaceptables. (shrink)

O presente estudo constitui um ensaio crítico de reflexão sobre a questão dos limites da linguagem em Wittgenstein. A perspectiva deste estudo observa, numa primeira parte, o próprio procedimento do método wittgen-steiniano e segue um modelo de discurso plural, a partir de várias perspectivas que, não só permitem desconstruir a aparente unidade da razão, como indagar interiormente do próprio limite da análise wittgensteiniana. Retomando a caracterização da linguagem e do pensamento nos seus traços fundamentais, desde o "Tractatus" até às "Investigações (...) Filosóficas", chama-se a atenção para os pontos de dificuldade, da indefinição e da cons-trutividade do modelo de Wittgenstein. A plena lição do "autómaton" da linguagem face a uma possível diferenciação dos signos e aprofundamento lógico, constitui uma parte desta reflexão que se complementa pela referência aos horizontes de resíduo do não-linguístico, ou até do indizível, numa dupla maneira de estabelecer os limites da linguagem. Enfim, e a título conclusivo, apontam-se, não apenas os contornos do que se entende como uma moral retórica da linguagem em Wittgenstein, mas para perspectivas originais de um reaprofundamento em termos etioló-gicos de diferenciação de escala da lógica e da linguagem, e de recuperação de uma intencionalidade psico-lógico-linguística superando aquela indiferen-ciação do dizer no automático da fala estatuída na "ordinary language". /// La présente étude constitue un essai critique qui réfléchie sur la question des limites du langage dans la philosophie de Wittgenstein. Dans une première partie la perspective de cette réflexion analise les procédés que Wittgenstein lui-même utilise dans sa méthode, et pour cela se sert d'un modèle de discours pluriel, lequel permet non seulement la déconstruction de l'apparente unité de la raison, mais aussi faire une enquête au dedans des limites de l'analyse wittgensteinienne. Reprenant la caractérisation du langage et de la pensée dans ses traits principaux, dès le "Tractatus" jusqu'aux "Investigations Philosophiques", on remarque les points de difficulté, d'indéfînition et de constructivité du modèle de Wittgenstein. La leçon de l'"autômaton" du langage face à une possible diférenciation des signes et l'approfondissement logique, constitue une partie de cette réflexion, qui se complémente par la référence aux horizons résiduels du non-linguistique, ou de l'indicible même, dans une double manière d'établir les limites du langage. Finalement, et comme une conclusion, on remarque, non seulement les contours de ce qu'on considère une morale réthorique du langage chez Witt- genstein, mais aussi pour les perspectives originelles qui permettent reprendre profondément, en termes étiologiques les différences d'échelles logique et linguistique, et récuperer une intentionalité psycho-logico-linguistique. Ainsi on réussit à supérer cette indifférenciation du dire dans l'authomatique de la parole qui s'etablie dans l'"ordinary language". /// The present study is a critical essay on the question of language's limits in Wittgenstein's thought. First of all, the view of this study observes how Wittgensteinian method proceeds. This investigation adopts a pluralistic model of speach, from several points of view, which not only allow to desconstruct the pseudo-unity of reason, but also, make possible to investigate about the inner limits of Wittgenstein's analysis. The Author remarks the difficulties of the non-definition and the construed vity of the Wittgensteinian model of thought, remembering the characteristic relationship language and thought, from Tractatus, to Philosophical Investigations. In order to a possible differenciation of signs and deeper logical analysis, the "automaton" of languages gives us a lesson which is another important part of this reflexion. This point is completed by the reference on the residual boundaries of non-linguistic, or even, non sayable, in a double way of establishing the limits of language. At last, and as a conclusion, the author points out, not only the outlines of the so called "rethoric moral" of language in Wittgenstein philosophy, but also to original views. These views allow a new deeper understanding, in ethiological terms. Different logical and linguistical scales are pointed as a mean, to recover a psycho-logico-linguistic intentionality, overcoming the indifferenciation of authomatic speech as established in "ordinary language". (shrink)

A pesquisa em história da filosofia visa compreender de onde o filósofo fala, a quem se dirige, contra quem escreve, por que decidiu escrever e os efeitos de sua escrita, unificando texto e contexto. Por isso, se distingue da leitura rigorosa que caracteriza o procedimento estrutural. Inaugurada como disciplina filosófica por Hegel, a história da filosofia foi interpretada de maneiras diferentes pela posição relativista, pela posição estrutural francesa e por Merleau-Ponty. Este propõe a noção de “impensado” das obras de pensamento, (...) como o excesso da obra, aquilo que dá a pensar e mantém a obra aberta. É esse impensado que nos abre a possibilidade de interrogar nosso próprio presente. Claude Lefort, aluno de Merleau-Ponty, vê como um enigma da obra de pensamento a possibilidade de suscitar discursos. E conclui que se escrever e interpretar são o mesmo, ler e interpretar também são o mesmo. (shrink)

Aging of the organism is associated with highly reproducible DNA methylation (DNAm) changes, which facilitate estimation of donor age. Cancer is also associated with DNAm changes, which may contribute to disease development. Here, we speculate that age‐associated DNAm changes may increase the risk of tumor initiation. Notably, when using epigenetic signatures for age‐estimations tumor cells are often predicted to be much older than the chronological age of the patient. We demonstrate that aberrant hypermethylation within the gene DNA methyltransferase 3A (DNMT3A) (...) – which may contribute to initiation of acute myeloid leukemia (AML) – is particularly observed in AML samples that reveal significantly more age‐associated DNAm changes. The functional relevance of age‐associated DNAm changes remains to be elucidated, but they occur genome wide, in a highly reproducible manner, and most likely influence chromatin organization – and hence may favor acquisition of aberrant DNAm patterns contributing to cancer in the elderly. (shrink)

Control of the population diversity in genetic algorithms applied to the protein structure prediction problem. Genetic Algorithms (GAs), a successful approach for optimization problems, usually fail when employed in the standard configuration in the protein structure prediction problem, since the solution space is very large and the population converges before a reasonable percentage of the possible solutions is explored. Thus, this work investigates the effect of increasing the diversity of the population on this problem by using Hypermutation and Random Immigrants, (...) two traditional population diversity control schemes, in the structure prediction of the proteins Crambin (PDB 1CRN), Met-Enkephalin (PDB 1PLW), and DNA-Ligand (PDB 1ENH). Results show a significant reduction of the minimal energy found, thanks to the diversity, but this does not necessarily means a higher similarity to the original structure.(Portuguese). (English) Copyright of Scientia is the property of Universidade do Vale do Rio dos Sinos and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (shrink)

O presente artigo aborda a dupla tarefa da teoria do conhecimento nas “Cinco Lições” de Edmund Husserl: a tarefa crítica denuncia o contrasenso inerente aos tipos de ceticismo em relação ao conhecimento; a tarefa positiva promove a pergunta pela essência do conhecimento. O artigo destaca que a dupla tarefa da teoria do conhecimento é o que determina o itinerário das “Cinco Lições”. O artigo revela, por fim, que a teoria do conhecimento equipara-se a uma fenomenologia do conhecimento, e (...) o que vale para esta fenomenologia valerá para a fenomenologia em geral. (shrink)

O ensaio discute as relações entre a produção poética e a experiência pandêmica. Estabelece o movimento identitário do narrador poético entre três modalidades de produção poética. Trata-se de triangulação artística que se envidencia entre Poema Minuto, Diet Poesia e Minimalismus Pandemicus. Para a caracterização do deslocamento intervérsico a tríplice produção artística, vale-se dos conceitos de “celebração móvel” de Hall (2006), das noções de dupla vocalidade da Signifyin(g) e da tripla dimensão de Exu e Iorubás, segundo Gates (1988), além da (...) ideia de política da conversão de West (1994). O ensaio sugere recorrer a uma ética do amor que, segundo West, teria a capacidade de estabelecer uma epistemologia poética com vistas a proteger a terra e fazer um mundo melhor. (shrink)

http://dx.doi.org/10.5007/1808-1711.2012v16n1p1 A teoria darwinista tem contribuído para a discussão de problemas nos mais diversos campos filosóficos, entre os quais se inclui a ética e a teoria moral. A sociobiologia e a psicologia evolucionista elucidaram muitos aspectos do comportamento social de diversas espécies animais, a partir de mecanismos como a seleção de parentesco e o altruísmo recíproco que, contudo, são insuficientes para explicar a cooperação no caso humano. Como alternativa, a teoria da dupla herança busca explicar o comportamento humano considerando (...) tanto a biologia quanto as ciências sociais. Segundo esta abordagem, a psicologia social humana é caracterizada por instintos sociais tribais e marcadores simbólicos, que resultam em uma mente que pressupõe princípios morais inatos e universais, selecionados para a vida em grupos orientados por normas sociais, mas que são plasticamente moldados à realidade cultural de cada sociedade. (shrink)

The RAD6 pathway of budding yeast, Saccharomyces cerevisiae, is responsible for a substantial fraction of this organism's resistance to DNA damage, and also for induced mutagenesis. The pathway appears to incorporate two different recovery processes, both regulated by RAD6. The error‐prone recovery prcess accounts for only a small amount of RAD6‐dependent resistance, but probably all induced mutagenesis. The underlying mechanism, for error‐prone recovery is very likely to be translesion synthesis. The error‐free recovery process accounts for most of RAD6‐dependent resistace, but (...) its mechanism is less clear; it may entail error‐free bypass by template switching and/or DNA gap filling by recombination. RAD6 regulates these activities by ubiquitinateins, and the roles they play in error‐free and error‐prone recovery, have not yet been established. (shrink)

O propósito do artigo é apresentar o conceito de ‘tópica política’ como o recurso teórico necessário para elucidação das determinações formais que estruturam as relações políticas em seu nível mais geral. A primeira seção do texto evoca os contextos doutrinários em que o conceito de tópica foi introduzido com intenções em alguma medida análogas às que animam o artigo, sendo brevemente considerados os usos do termo nas obras de Aristóteles, Kant e Freud. A segunda seção examina os conceitos de divisão (...) e unidade, tratando de mostrar que as sociedades humanas são ao mesmo tempo necessariamente divididas e unificadas. Divididas na medida em que, como já mostrara Aristóteles e como o repetirá Tomás de Aquino, sendo a sociedade composta por uma multidão, o estatuto de sua unidade é necessariamente sui generis: ela não pode ser absolutamente una, pois, se o fosse, já não poderia ser uma cidade. Unificadas na medida em que as diferenças e distinções sociais, na medida em que adquirem caráter político, sobrevêm sempre dentro de uma sociedade, a unidade desta última tendo estatuto necessariamente reflexivo. A terceira seção introduz o exame dos conceitos de identidade e representação a partir da análise crítica da tese do jovem Marx de acordo com a qual a democracia é a verdade da monarquia mas a monarquia não é verdade da democracia. A seção prossegue com a retomada do exame destas noções a partir das análises de Carl Schmitt. A quarta e última seção do texto trata de explicitar os ganhos críticos, heurísticos e metapolíticos que a introdução do conceito de tópica na teoria política pode proporcionar. (shrink)

For nearly two decades, nonengineered human DNA was patented without challenge. The US Supreme Court recently agreed that many of those patents do not fit accurately into any currently accepted scheme of intellectual property protection. One should consider: whether DNA fits into other forms of property protection (land, moveables, chattels, etc.); whether DNA warrants a new and unique form of property protection, or whether DNA belongs to the class of objects generally considered to be as “the commons.” Current schemes of (...) patent protection for genes are entirely new, unwarranted by precedent, and utterly aberrant in applying the law of patent. Nonetheless, it bears examining how intellectual property schemes might serve as guidance for new forms of intellectual property protection for genes, if indeed those genes fit into classical dimensions of intellectual property. Private ownership of property has emerged as the dominant legal institution covering modes of possession. (shrink)

The political and financial investments in the implementation of forensic DNA databases and the ethical issues related to their use and expansion justify inquiries into their performance and general utility. The main function of a forensic DNA database is to produce matches between individuals and crime scene stains, which requires a constant input of individual profiles and crime scene stains. This is conditioned, among other factors, by the legislation, namely the criteria for inclusion of profiles and the periods of time (...) and conditions for their retention and/or deletion. This article aims to provide an overview of the different legislative models for DNA databasing in Europe and ponder if wider inclusion criteria – and, consequently, database size – translates into more matches between profiles of crime scene stains and included individuals. The legislation governing forensic DNA databases in 22 countries in the European Union was analysed in order to propose a typology of two major groups of legislative criteria for inclusion/retention of profiles that can be classified as having either expansive effects or restrictive effects. We argue that expansive criteria for inclusion and retention of profiles do not necessarily translate into significant gains in output performance. (shrink)

This paper focuses on the question of whether DNA patents help or hinder scientific discovery and innovation. While DNA patents create a wide variety of possible benefits and harms for science and technology, the evidence we have at this point in time supports the conclusion that they will probably promote rather than hamper scientific discovery and innovation. However, since DNA patenting is a relatively recent phenomena and the biotechnology industry is in its infancy, we should continue to gather evidence about (...) the effects of DNA patenting on scientific innovation and discovery as well the economic, social, and legal conditions relating to intellectual property in biotechnology. We should give the free market, the courts, researchers, and patent offices a chance to settle issues related to innovation and discovery, before we seek legislative remedies, since new laws proposed at this point would lack adequate foresight and could do more harm than good. However, we should be open to new laws or regulations on DNA patents if they are required to in order to deal with some of the biases and limitations of the free market. (shrink)

DNA glycosylases remove aberrant DNA nucleobases as the first enzymatic step of the base excision repair (BER) pathway. The alkyl‐DNA glycosylases AlkC and AlkD adopt a unique structure based on α‐helical HEAT repeats. Both enzymes identify and excise their substrates without a base‐flipping mechanism used by other glycosylases and nucleic acid processing proteins to access nucleobases that are otherwise stacked inside the double‐helix. Consequently, these glycosylases act on a variety of cationic nucleobase modifications, including bulky adducts, not previously associated with (...) BER. The related non‐enzymatic HEAT‐like repeat (HLR) proteins, AlkD2, and AlkF, have unique nucleic acid binding properties that expand the functions of this relatively new protein superfamily beyond DNA repair. Here, we review the phylogeny, biochemistry, and structures of the HLR proteins, which have helped broaden our understanding of the mechanisms by which DNA glycosylases locate and excise chemically modified DNA nucleobases. (shrink)

Currently there are persistent doubts about the meaning and contributions of the gene concept, mostly related to its interpretation as a stretch of DNA encoding a single functional product, i.e., the classical molecular gene concept. There is, however, much conceptual variation around genes, leading to important difficulties in genetics teaching. We investigated whether and how conceptual variation related to the gene concept and gene function models is present in school science and what potential problems it may bring to genetics teaching (...) and learning. Here, we report results on how ideas about genes and gene function are treated in textbooks and appear in students’ views and, also, about a teaching strategy for improving higher education students’ understanding of scientific models and conceptual variation around genes and their functions. (shrink)

DNA profiling is a well-established technology for use in the criminal justice system, both in courtrooms and elsewhere. The fact that DNA profiles are based on non-coding DNA and do not reveal details about the physical appearance of an individual has contributed to the acceptability of this type of evidence. Its success in criminal investigation, combined with major innovations in the field of genetics, have contributed to a change of role for this type of evidence. Nowadays DNA evidence is not (...) merely about identification, where trace evidence is compared to a sample taken from a suspect. An ever-growing role is anticipated for DNA profiling as an investigative tool, a technique aimed at generating a suspect where there is none. One of these applications is the inference of visible traits. As this article will show, racial classifications are at the heart of this application. The Netherlands and its legal regulation of 'externally visible traits' will serve as an example. It will be shown that, to make this technology work, a large number of actors has to be enrolled and their articulations invited. This indicates that instead of a 'silent witness', a DNA profile should rather be seen as an 'articulate collective'. Based on two cases, I argue that the normativity of visible traits is context-dependent. Taking into account the practices in which technology is put to use alerts us to novel ethical questions raised by their application. (shrink)

Certain sequences of double‐helical DNA can be recognized and tightly bound by oligonucleotides. The effects of such triple‐helical structures on DNA binding proteins have been studied. Stabilities of DNA triple‐helices at or near physiological conditions are sufficient to inhibit DNA binding proteins directed to overlapping sites. Such proteins include restriction endonucleases, methylases, transcription factors, and RNA polymerases. These and Other results suggest that oligonucleotide‐directed triple‐helix formation could provide the basis for designing artificial gene repressors. The general question of whether biological (...) systems employ RNA molecules for recognition and regulation of double‐helical DNA is discussed. (shrink)

DNA methylation is a quintessential epigenetic mechanism. Widely considered a stable regulator of gene silencing, it represents a form of “molecular braille,” chemically printed on DNA to regulate its structure and the expression of genetic information. However, there was a time when methyl groups simply existed in cells, mysteriously speckled across the cytosine building blocks of DNA. Why was the code of life chemically modified, apparently by “no accident of enzyme action” (Wyatt 1951 )? If all cells in a body (...) share the same genome sequence, how do they adopt unique functions and maintain stable developmental states? Do cells remember? In this historical perspective, I review epigenetic history and principles and the tools, key scientists, and concepts that brought us the synthesis and discovery of prokaryotic and eukaryotic methylated DNA. Drawing heavily on Gerard Wyatt’s observation of asymmetric levels of methylated DNA across species, as well as to a pair of visionary 1975 DNA methylation papers, 5-methylcytosine is connected to DNA methylating enzymes in bacteria, the maintenance of stable cellular states over development, and to the regulation of gene expression through protein-DNA binding. These works have not only shaped our views on heritability and gene regulation but also remind us that core epigenetic concepts emerged from the intrinsic requirement for epigenetic mechanisms to exist. Driven by observations across prokaryotic and eukaryotic worlds, epigenetic systems function to access and interpret genetic information across all forms of life. Collectively, these works offer many guiding principles for our epigenetic understanding for today, and for the next generation of epigenetic inquiry in a postgenomics world. (shrink)

Those objecting to human DNA patenting frequently do so on the grounds that the practice violates or threatens human dignity. For example, from 1993 to 1994, more than thirty organizations representing indigenous peoples approved formal declarations objecting to the National Institutes of Health's bid to patent viral DNA taken from subjects in Papua New Guinea and the Solomon Islands. Although these were not patents on human DNA, the organizations argued that the patents could harm and exploit indigenous peoples and violate (...) their cultural values. NIH eventually dropped one of its patent applications.On May 18, 1995, 180 religious leaders, led by biotechnology critic Jeremy Rifkin, held a press conference objecting to DNA patenting in Washington, D.C. In their “Joint Appeal against Human and Animal Patenting,” these leaders decried any attempt to patent nature. Some of the more outspoken members of the Joint Appeal likened DNA patenting to slavery, while others objected to treating human beings as marketable commodities. In his recent book, The Biotech Century, Rifkin rehashed the objections to DNA patenting voiced by members of the Joint Appeal. (shrink)

Eminent scientists are well-placed to bring the novel works of others, even if not in their own areas of expertise, to general attention. In so doing, they may be able to extend original accounts or introduce new terminologies, but they are basically messengers, not innovators. In the 1940s an evolutionary theory of biological aging was explained by Peter Medawar, and informational concepts relating to DNA were explained by Erwin Schrödinger. Both explanations were eventually traced back to the Victorian polymath Samuel (...) Butler—one by Medawar’s research associate Alex Comfort, and the other, albeit indirectly, by Schrödinger himself. In his time Butler’s works were too erudite for general readers and too laden with populist jargon for contemporary experts to take seriously. However, today it appears counterfactually plausible that an early acceptance of his ideas would have greatly quickened the pace of research. (shrink)

In the past twenty years, advances in forensic DNA technology have revolutionized the American criminal justice system. The use of forensic DNA testing in America began in 1987, and its demonstrated scientific accuracy quickly led jurisdictions to accept expert testimony regarding DNA matches between suspects and crime scene evidence. Wielding the power to exonerate the innocent and apprehend the guilty, the use of DNA identification technology has become an indispensable resource for prosecutors and law enforcement officials, as well as for (...) defense lawyers representing persons falsely accused or wrongfully convicted of crimes they did not commit. As states began to compile DNA profiles from convicted offenders, the need for a repository for these profiles resulted in the DNA database.Originally, DNA databases included only “those classes of offenders with a high recidivism rate, such as sex offenders and violent felons.” Recognizing the crime-solving potential of this technology, state legislatures soon began to expand the scope of DNA database statutes to include broader classes of offenders. (shrink)

The paper tries to show that an evolutionary perspective helps us to address what is called the adaptation problem, that is, the remarkable coherence, and seemingly successful design, existing between our cognitive tools and the phenomena of the material world. It argues that a fine-grained description of the structure and function of experimental techniques—as a special type amongst evolving scientific practices—is a condition for a better understanding and, ultimately, an explanation of how adaptation among the heterogeneous elements of experimental knowledge (...) is attained. Some apparently contradictory features of techniques, such as their high context-dependency and their capabilities to reproduce and diversify outside their original contexts, are addressed with the help of the concepts of technical variation and the historical entrenchment of phenomena in techniques. In order to do so, a case-study on the construction of satellite-DNA and the evolution of nucleic acid hybridization, a research project carried out by Roy J. Britten and his colleagues in the 1960s, is presented in detail. This case illustrates the close relationship existing between the evolution of techniques and the stabilization of phenomena in experimental biology. (shrink)

The proliferation of mitochondrial DNA (mtDNA) with deletion mutations has been linked to aging and age related neurodegenerative conditions. In this study we model the effect of mtDNA half-life on mtDNA competition and selection. It has been proposed that mutation deletions (mtDNAdel\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\text {mtDNA}_{del}$$\end{document}) have a replicative advantage over wild-type (mtDNAwild\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\text {mtDNA}_{wild}$$\end{document}) and that this is detrimental to the host cell, especially in post-mitotic (...) cells. An individual cell can be viewed as forming a closed ecosystem containing a large population of independently replicating mtDNA. Within this enclosed environment a selfishly replicating mtDNAdel\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\text {mtDNA}_{del}$$\end{document} would compete with the mtDNAwild\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\text {mtDNA}_{wild}$$\end{document} for space and resources to the detriment of the host cell. In this paper, we use a computer simulation to model cell survival in an environment where mtDNAwild\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\text {mtDNA}_{wild}$$\end{document} compete with mtDNAdel\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\text {mtDNA}_{del}$$\end{document} such that the cell expires upon mtDNAwild\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\text {mtDNA}_{wild}$$\end{document} extinction. We focus on the survival time for long lived post-mitotic cells, such as neurons. We confirm previous observations that mtDNAdel\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\text {mtDNA}_{del}$$\end{document} do have a replicative advantage over mtDNAwild\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\text {mtDNA}_{wild}$$\end{document}. As expected, cell survival times diminished with increased mutation probabilities, however, the relationship between survival time and mutation rate was non-linear, that is, a ten-fold increase in mutation probability only halved the survival time. The results of our model also showed that a modest increase in half-life had a profound affect on extending cell survival time, thereby, mitigating the replicative advantage of mtDNAdel\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\text {mtDNA}_{del}$$\end{document}. Given the relevance of mitochondrial dysfunction to various neurodegenerative conditions, we propose that therapies to increase mtDNA half-life could significantly delay their onset. (shrink)

A small number of states have enacted laws that authorize the taking and analysis of DNA from certain categories of arrestees. This article addresses the constitutionality, under the Fourth Amendment, of taking DNA samples from persons subject to arrest.

In this review, we discuss how two evolutionarily conserved pathways at the interface of DNA replication and repair, template switching and break-induced replication, lead to the deleterious large-scale expansion of trinucleotide DNA repeats that cause numerous hereditary diseases. We highlight that these pathways, which originated in prokaryotes, may be subsequently hijacked to maintain long DNA microsatellites in eukaryotes. We suggest that the negative mutagenic outcomes of these pathways, exemplified by repeat expansion diseases, are likely outweighed by their positive role in (...) maintaining functional repetitive regions of the genome such as telomeres and centromeres. Break-induced replication and template switching are conserved mechanisms of replication fork restart. They do not cause microsatellite instability in prokaryotes, but promote repeat expansion in eukaryotes. We suggest that TS and BIR persisted in eukaryotes despite their mutagenic potential because they help maintain long repetitive telomeres and centromeres. (shrink)

DNA replication stress threatens ordinary DNA synthesis. The evolutionarily conserved DNA replication stress response pathway involves sensor kinase Mec1/ATR, adaptor protein Mrc1/Claspin, and effector kinase Rad53/Chk1, which spurs a host of changes to stabilize replication forks and maintain genome integrity. DNA replication forks consist of largely distinct sets of proteins at leading and lagging strands that function autonomously in DNA synthesis in vitro. In this article, we discuss eSPAN and BrdU‐IP‐ssSeq, strand‐specific sequencing technologies that permit analysis of protein localization and (...) DNA synthesis at individual strands in budding yeast. Using these approaches, we show that under replication stress Rad53 stalls DNA synthesis on both leading and lagging strands. On lagging strands, it stimulates PCNA unloading, and on leading strands, it attenuates the replication function of Mrc1‐Tof1. We propose that in doing so, Rad53 couples leading and lagging strand DNA synthesis during replication stress, thereby preventing the emergence of harmful ssDNA. (shrink)

The paper uses insights from the so-called rape in disguise case study to describe forensic DNA practices in the Netherlands in late 1980s. It describes how "reliabilities" of forensic DNA practices were achieved. One such reliability - convincing evidence - proliferates body parts through time and space. Then, attention shifts to the individual who was suspected of having committed the rape. He was asked to deliver tissue for DNA typing, but refused to do so. Hence DNA typing could not be (...) used to connect the suspect to a cervical smear collected from the body of the victim. His refusal and the legal impossibility to use force to obtain his biological material led first to questions in the Dutch parliament and then to the Dutch forensic DNA law. Other legal measures enacted after this are also described. I argue that, by means of the various Dutch forensic DNA laws and new forensic genetic techniques, the application of forensic DNA practices have shifted from identification and evidence to a tool for criminal investigation and prevention of future crimes. In the final part of the paper, the right to inviolability of the body and its synonym bodily integrity are emphasised. I argue that despite the various forensic DNA laws, bodily integrity of obtained tissue for DNA typing is still at stake as the result of convincing evidence. (shrink)

Balanced pools of deoxyribonucleoside triphosphates (dNTPs) are essential for DNA replication to occur with maximum fidelity. Conditions that create biased dNTP pools stimulate mutagenesis, as well as other phenomena, such as recombination or cell death. In this essay we consider the effective dNTP concentrations at replication sites under normal conditions, and we ask how maintenance of these levels contributes toward the natural fidelity of DNA replication. We focus upon two questions. (1) In prokaryotic systems, evidence suggests that replication is driven (...) by small, localized, rapidly replenished dNTP pools that do not equilibrate with the bulk dNTP pools in the cell. Since these pools cannot be analyzed directly, what indirect approaches can illuminate the nature of these replication‐active pools? (2) In eukaryotic cells, the normal dNTP pools are highly asymmetric, with dGTP being the least abundant nucleotide. Moreover, the composition of the dNTP pools changes as cells progress through the cell cycle. To what extent might these natural asymmetries contribute toward a recently described phenomenon, the differential rate of evolution of different genes in the same genome? (shrink)

The debate over recombinant DNA research is a unique event, perhaps a turning point, in the history of science. For the first time in modern history there has been widespread public discussion about whether and how a promising though potentially dangerous line of research shall be pursued. At root the debate is a moral debate and, like most such debates, requires proper assessment of the facts at crucial stages in the argument. A good deal of the controversy over recombinant DNA (...) research arises because some of the facts simply are not yet known. There are many empirical questions we would like to have answered before coming to a decision-questions about the reliability of proposed containment facilities, about the viability of enfeebled strains of E. coli, about the ways in which pathogenic organisms do their unwelcome work, and much more. But all decisions cannot wait until the facts are available; some must be made now. It is to be expected that people with different hunches about what the facts will turn out to be will urge different decisions on how recombinant DNA research should be regulated. However, differing expectations about the facts have not been the only fuel for controversy. A significant part of the current debate can be traced to differences over moral principles. Also, unfortunately, there has been much unnecessary debate generated by careless moral reasoning and a failure to attend to the logical structure of some of the moral arguments that have been advanced. (shrink)

This paper defends a moralized account of conventions, according to which conventional practices are necessarily normative reasons that are ultimately grounded on moral principles . It argues that a convention exists just in case the fact that others participate in some common practice as well as facts about their motivating reasons for doing so, justify conformity to that practice. The paper locates this moralized account within the relevant philosophical literature and argues that it does better than its rivals in explaining (...) the presence of both motivating and normative reasons in our concept of convention. (shrink)

A hypothesis for the control of eukaryotic DNA replication at the chromosomal level is proposed. The specific regulatory problem arises from the subdivision of the genome into thousands of individually replicating units, each of which must be duplicated a single time during S‐phase. The hypothesis is based on the finding of direct repeats at replication origins. Such repeats can adopt, beyond the full‐length double helical structure, another configuration exposing two single‐stranded loops that provide suitable templates for the initiation of DNA (...) replication. Any further initiation at the same origin is excluded as the single strandedness is eliminated by the replication process. Restoration of the initiable loop structure is proposed to occur by DNA‐protein rearrangements involved in chromosome condensation and duplication of the chromosomal protein backbone during mitosis. A possible role of the maturation promoting factor (MPF) is suggested. (shrink)

Since the mid-1990s most EU Member States have established a national forensic DNA database. These mass repositories of DNA profiles enable the police to identify DNA stains which are found at crime scenes and are invaluable in criminal investigation. Governments have always brushed aside privacy objections by stressing that the stored DNA profiles do not contain sensitive genetic information on the included individuals and that they reside under the statutory privacy protection regulations. However, it has been generally overlooked that the (...) police also store the DNA samples from which the DNA profiles are derived. Although these DNA samples are actually a potential source of genetic information, they have so far scarcely been the subject of discussion. In this article we will show that both European and national regulations offer inadequate protection to completely prevent function creep, that is, the use of these forensic DNA samples for purposes beyond those envisaged at the time of collection. (shrink)

O conceito de potentia possui uma pluralidade de sentidos na obra de Hobbes, sendo empregado na física, na antropologia, nas reflexões sobre o direito e sobre a política, bem como no discurso sobre Deus e seus atributos. Neste artigo, o exame será circunscrito ao conceito hobbesiano de potência (power) no Short Tract em seu diálogo com a tradição aristotélica da potência e do ato, isto é, ao conceito físico de potência por meio do qual os movimentos são explicados. O que (...) pretendo indicar é que já nessa obra esse conceito se forjou em oposição ao conceito aristotélico e à tradição escolástica, por mais que essa primeira formulação da noção de potência seja problemática. Hobbes fundamenta uma dupla fonte do determinismo no Short Tract, fonte que se tornará una com a reformulação do conceito de potência nos textos posteriores, como exporei na segunda parte do artigo. (shrink)

The ethically controversial option of genetic population screening used to be restricted to a small number of rather rare diseases by methodological limitations which are now about to be overcome. With the new technology of DNA microarrays ("DNA chip"), emerging from the synthesis of microelectronics and molecular biology, methods are now at hand for the development of mass screening programmes for a wide spectrum of genetic traits. Thus, the DNA chip may be the key technology for a refined preventive medicine (...) as well as a new dimension of eugenics. The forthcoming introduction of the DNA chip technology into medical practice urgently requires an internationally consistent framework of ethical standards and legal limitations if we do not want it to become a new Pandora's box. (shrink)

In the spring of 2005, the Portuguese government passed legislation paving the way for all residents to contribute their DNA to a national database to be used for medical and forensic purposes. There was no significant opposition. In sharp contrast, the United States will experience a contentious debate with strong opposition from many groups if and when such a law is proposed. Some of the reasons have to do with a history of sharply different experiences with, and trust of, the (...) criminal justice system. (shrink)

The concept of regulatory ‘checkpoints’ in the eukaryotic cycle has proved to be a fruitful one. Here, its applicability to the bacterial cell cycle is examined. A primitive DNA damage checkpoint operates in E. coli such that, after exposure to ultraviolet light, while excision repair occurs, chromosome replication continues very slowly with the production of discontinuous daughter strands. The slower the rate of excision of photoproducts, the greater the delay before the normal rate of DNA replication is restored, the additional (...) time for repair ensuring that normal survival is maintained. A model is proposed in which replication rate is controlled by the ratio of RecAcoated to uncoated single stranded regions of DNA in the replication fork. There are also two cell division inhibitors SulA (=SfiA) and SfiC under the control of the SOS system and sensitive to DNA damage, but they are irrelevant to the survival of wild‐type bacteria under normal conditions. In strains where SulA and SfiC do not operate, inhibition is not influenced by the rate of excision repair and so fails one of the criteria for a DNA damage checkpoint, namely the monitoring of the DNA for the level of residual damage. (shrink)

The existing literature on the development of recombinant DNA technology and genetic engineering tends to focus on Stanley Cohen and Herbert Boyer's recombinant DNA cloning technology and its commercialization starting in the mid-1970s. Historians of science, however, have pointedly noted that experimental procedures for making recombinant DNA molecules were initially developed by Stanford biochemist Paul Berg and his colleagues, Peter Lobban and A. Dale Kaiser in the early 1970s. This paper, recognizing the uneasy disjuncture between scientific authorship and legal invention (...) in the history of recombinant DNA technology, investigates the development of recombinant DNA technology in its full scientific context. I do so by focusing on Stanford biochemist Berg's research on the genetic regulation of higher organisms. As I hope to demonstrate, Berg's new venture reflected a mass migration of biomedical researchers as they shifted from studying prokaryotic organisms like bacteria to studying eukaryotic organisms like mammalian and human cells. It was out of this boundary crossing from prokaryotic to eukaryotic systems through virus model systems that recombinant DNA technology and other significant new research techniques and agendas emerged. Indeed, in their attempt to reconstitute 'life' as a research technology, Stanford biochemists' recombinant DNA research recast genes as a sequence that could be rewritten thorough biochemical operations. The last part of this paper shifts focus from recombinant DNA technology's academic origins to its transformation into a genetic engineering technology by examining the wide range of experimental hybridizations which occurred as techniques and knowledge circulated between Stanford biochemists and the Bay Area's experimentalists. Situating their interchange in a dense research network based at Stanford's biochemistry department, this paper helps to revise the canonized history of genetic engineering's origins that emerged during the patenting of Cohen-Boyer's recombinant DNA cloning procedures. (shrink)

Histone octamers (hos) and DNA topoisomerase I contribute, along with other proteins, to the higher order structure of chromatin. Here we report on the similar topological requirements of these two protein model systems for their interaction with DNA. Both histone octamers and topoisomerase I positively and consistently respond to DNA supercoiling and curvature, and to the spatial accessibility of the preferential interaction sites. These findings (1) point to the relevance of the topology‐related DNA conformation in protein interactions and define the (...) particular role of the helically phased rotational information; and (2) help to solve the apparent paradoxical behaviour of ubiquitous and abundant proteins that interact with defined DNA sites in spite of the lack of clear sequence consensuses. Considering firstly, that the interactions with DNA of both DNA topoisomerase I and histone octamers are topology‐sensitive and that upon their interaction the DNA conformation is modified; and secondly, that similar behaviours have also been reported for DNA topoisomerase II and histone H1, a topology‐based functional correlation among all these determinants of the higher order structure of chromatin is here suggested. (shrink)