Formation of a multicellular organism is a complex process involving differentiation and morphogenesis. During early vertebrate development, the radial symmetric organization of the egg is transferred into a bilateral symmetric organism with three distinct body axes: anteroposterior (AP), dorsoventral, and left–right. Due to cellular movements and proliferation, the body elongates along the AP axis. How are these processes coupled? Two recent publications now indicate that cell migration as well as orientated cell divisions contribute to axis elongation. The processes are coupled (...) through the planar cell polarity pathway.1 At the same time, the AP axis is patterned independently of convergent extension. This process, however, is required for cell migration and represents a cue for polarized cell motility during gastrulation. Thus, it is AP polarity that instructs individual cells how to orientate with respect to the embryonic axis and provides positional information for the process of convergent extension.2 BioEssays 26:1272–1275, 2004. © 2004 Wiley Periodicals, Inc. (shrink)

Se realiza una revisión bibliográfica con el objetivo de analizar los diferentes códigos éticos y deontológicos internacionales, regionales y nacionales de los que se nutre la especialidad de psiquiatría. Se concluye que el comportamiento ético se basa en el sentido de la responsabilidad individual de cada psiquiatra hacia cada paciente y en la capacidad de ambos para determinar cuál es la conducta correcta y más apropiada. Las normas externas y las directrices, tales como los códigos de conducta profesional, las aportaciones (...) de la ética y de las normas legales, no garantizan por sí solas la práctica ética de la medicina, pero constituyen un importante marco referencial. A literature review was performed with the objective of analyzing the various international, regional and national ethical and deontological codes that the psychiatry specialty feeds on. It is concluded that ethical behavior is based on the sense of individual responsibility of each psychiatrist to each patient and the ability of both to determine what the correct and appropriate behavior is. External standards and guidelines, such as professional codes of conduct, the study of ethics and legal standards alone do not guarantee the ethical practice of medicine but are an important framework. (shrink)

Dieser Band untersucht die Beziehungen zwischen staatlichem (kolonialem und post-kolonialem) Recht, islamischem Recht und Gewohnheitsrecht in der islamischen Welt. Die geographische Spannbreite der zwanzig Beiträge reicht vom muslimischen Andalusien und Nordafrika über das osmanische Südosteuropa, den Jemen, Iran, Afghanistan, den Nordkaukasus und Mittelasien bis nach Uighurien (China) und Indonesien. Ein besonderer Schwerpunkt liegt auf den muslimischen Gesellschaften des Russischen Reichs bzw. der ehemaligen Sowjetunion, deren reiche regionale Rechtstraditionen in der allgemeinen Diskussion um den Rechtspluralismus bislang kaum Beachtung fanden. Der vergleichende (...) Ansatz zeigt nicht nur zahlreiche Parallelen in den Entwicklungen auf, sondern bietet auch einen Einblick in die unterschiedlichen Methoden und Herangehensweisen von Rechtsanthropologen, Islamwissenschaftlern, Historikern und Juristen in Ost und West. (shrink)

Wnt proteins can activate different intracellular signaling cascades in various organisms by interacting with receptors of the Frizzled family. The first identified Wnt signaling pathway, the Wnt/β‐catenin pathway, has been studied in much detail and is highly conserved among species. As to non‐canonical Wnt pathways, the current situation is more nebulous partly because the intracellular mediators of this pathway are not yet fully understood and, in some cases, even identified. However, there are increasing data that prove the existence of non‐canonical (...) Wnt signaling and demonstrate its involvement in different developmental processes. In vertebrates, Wnt‐11 and Wnt‐5A can activate the Wnt/JNK pathway, which resembles the planar cell polarity pathway in Drosophila. The Wnt/Ca2+‐pathway has only been described in Xenopus and zebrafish so far and it is unclear whether it also exists in other organisms. Two recent papers provide us with new insight into non‐canonical Wnt signaling by (1) presenting a new intracellular mediator of non‐canonical signaling in Xenopus1 and (2) implicating the existence of an additional non‐canonical Wnt signaling pathway in flies.2 BioEssays 24:881–884, 2002. © 2002 Wiley Periodicals, Inc. (shrink)

In this paper we discuss in some depth the main theorems pertaining to Carnot’s theory of transversals, their initial reception by Servois, and the applications that Brianchon made of them to the theory of conic sections. The contributions of these authors brought the long-forgotten theorems of Desargues and Pascal fully to light, renewed the interest in synthetic geometry in France, and prepared the ground from which projective geometry later developed.

In 1824 Sadi Carnot published Réflexions sur la Puissance Motrice du Feu in which he founded almost the entire thermodynamics theory. Two years after his death, his friend Clapeyron introduced the famous diagram PV for analytically representing the famous Carnot’s cycle: one of the main and crucial ideas presented by Carnot in his booklet. Twenty-five years later, in order to achieve the modern version of the theory, Kelvin and Clausius had to reject the caloric hypothesis, which had (...) influenced a few of Carnot’s arguments. Relying on the possibility of studying the history of science by means of logical investigation, in this paper I shall propose an historical/epistemological research on Sadi Carnot’s original thermodynamics theory in which the French scientist presents more than two principles, all of which are expressed by double negated sentences (generally speaking) within non-classical logic. (shrink)

Lazare Carnot was the unique example in the history of science of someone who inadvertently owed the scientific recognition he eventually achieved to earlier political prominence. He and his son Sadi produced work that derived from their training as engineers and went largely unnoticed by physicists for a generation or more, even though their respective work introduced concepts that proved fundamental when taken up later by other hands. There was, moreover, a filial as well as substantive relation between the (...) work of father and son. Sadi applied to the functioning of heat engines the analysis that his father had developed in his study of the operation of ordinary machines. Specifically, Sadi's idea of a reversible process originated in the use his father made of geometric motions in the analysis of machines in general. (shrink)

We present historical and epistemological notes on the relationships between Chemistry–Physics as dating back to two scientific revolutions: Lavoisier’s Traité Élémentaire de Chimie (1789) and by Sadi Carnot’s Réflexions sur la Puissance Motrice du Feu (1824). Their scientific paradigms and mathematical interpretations of chemical and physical phenomena did not made use of infinitesimal analysis as, i.e., exposed within mechanics and, generally speaking, they were totally different from notable Newtonian paradigm survived until to 19th century. An anomaly was, and two (...) revolutions were produced. (shrink)

Our concern is in explaining how and why models give us useful knowledge. We argue that if we are to understand how models function in the actual scientific practice the representational approach to models proves either misleading or too minimal. We propose turning from the representational approach to the artefactual, which implies also a new unit of analysis: the activity of modelling. Modelling, we suggest, could be approached as a specific practice in which concrete artefacts, i.e., models, are constructed with (...) the help of specific representational means and used in various ways, for example, for the purposes of scientific reasoning, theory construction and design of experiments and other artefacts. Furthermore, in this activity of modelling the model construction is intertwined with the construction of new phenomena, theoretical principles and new scientific concepts. We will illustrate these claims by studying the construction of the ideal heat engine by Sadi Carnot. (shrink)

The case study is presented in the title: Hrabanus Maurus’s In honorem sanctae crucis and Berthold of Nuremberg’s two-part work Liber de misteriis et laudibus sancta crucis and the supplement Liber de misteriis et laudibus interemerate Virginis genitrices Dei et Domini nostril Ihesu ) are confronted and dissected; and the use of the word “transformation” is key to the analytical and interpretive possibilities concerning the medieval formulas the author presents. Close to five hundred years separate the carmina figurata of (...) the Carolingian abbot and the text-images of the Dominican lector and both follow on antique traditions. With more than two hundred pictures of diagrams and illuminations from a multitude of codices, architectural details and religious objects, Hamburger furnishes our understanding of transformation in medieval visual cultures and of the centrality of diagrams in artistic productions. (shrink)

This book offers insights relevant to modern history and epistemology of physics, mathematics and, indeed, to all the sciences and engineering disciplines emerging of 19th century. This research volume is the first of a set of three Springer books on Lazare Nicolas Marguérite Carnot’s (1753–1823) remarkable work: Essay on Machines in General (Essai sur les machines en général [1783] 1786). The other two forthcoming volumes are: Principes fondamentaux de l’équilibre et du mouvement (1803) and Géométrie de position (1803). Lazare (...) Carnot – l'organisateur de la victoire – in Essai sur le machine en général (1786) assumed that the generalization of machines was a necessity for society and its economic development. Subsequently, his new coming science applied to machines attracted considerable interest for technician, as well, already in the 1780’s. With no lack in rigour, Carnot used geometric and trigonometric rather than algebraic arguments, and usually went on to explain in words what the formulae contained. His main physical– mathematical concepts were the Geometric motion and Moment of activity–concept of Work . In particular, he found the invariants of the transmission of motion (by stating the principle of the moment of the quantity of motion) and theorized the condition of the maximum efficiency of mechanical machines (i.e., principle of continuity in the transmission of power). While the core theme remains the theories and historical studies of the text, the book contains an extensive Introduction and an accurate critical English Translation – including the parallel text edition and substantive critical/explicative notes – of Essai sur les machines en général (1786). The authors offer much-needed insight into the relation between mechanics, mathematics and engineering from a conceptual, empirical and methodological, and universalis point of view. As a cutting–edge writing by leading authorities on the history of physics and mathematics, and epistemological aspects, it appeals to historians, epistemologist–philosophers and scientists (physicists, mathematicians and applied sciences and technology). (shrink)

Neste artigo, temos como objetivo um paralelismo epistemológico entre a integração de conceitos (FAUCONNIER; TURNER, 2002) e a eficiência de uma máquina termodinâmica (CARNOT, 1824). Nossa hipótese é a de que o comportamento linguístico equivalha a um sistema adaptativo complexo (DUQUE, 2016),com eficiência máxima em seus processos comunicativos,tal qual uma máquina termodinâmica. Com base em nosso objeto,a saber, as redes de integração conceptual (SILVA, 2019), percebemos que o ser humano mistura conceitos a partir de muitas frentes de informação (frames) (...) e compõe uma estrutura conceptual nova, fruto da amálgama de informações desses frames. Assim, baseando-nos emum método qualitativo, apoiado na visão de Silverman (2000), concluímos que a rede de integração conceptual funciona de forma semelhante a uma máquina térmica de Carnot, na qual elementos são processados de forma a garantir a máxima eficiência.Palavras-chave: Integração conceptual. Máquina de Carnot. Sistemas adaptativos complexos. Comunicação. AbstractIn this article, we aim at an epistemological parallelism between the conceptual blending (FAUCONNIER; TURNER, 2002) and the efficiency of a thermodynamic machine (CARNOT, 1824). Our hypothesis is that linguistic behavior amounts to a complex adaptive system (DUQUE, 2016) with maximum efficiency in its communicative processes in the same way as a thermodynamic machine. Supported by our object, namely the conceptual integration networks (SILVA, 2019), we perceive that the human being mixes concepts from many information fronts (frames) and composes a new conceptual structure, resulting from the amalgamation of information from these frames. Thus, based on the qualitative method supported by Silverman's (2000) vision, we conclude that the conceptual integration network works similarly to a Carnot thermal machine, in which elements are processed in order to ensure maximum efficiency.Keywords: Conceptual blending. Carnot machine.Complex adaptative systems. Communication. ORCIDhttps://orcid.org/0000-0001-7626-1504https://orcid.org/0000-0001-5263-8979. (shrink)