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In human skin transplanted to the back of 3 strains of immuno-deficient mice the functin of the eccrine sweat glands of the human transplant was tested by topical intradermal application of pilocarine, adrenaline and atropine+pilocarpine. Sweat responses were observed in pre-selected fields of observation by means of video macroscope. The iodine strarch reaction served as an indicator for the appearance of seat sport and permitted the evaluation of areas wetted by sweat in the field of observation. Among 9 animals tested, the hybrids between the CB-17-scid mouse and the BALB/cA-nu mouse (BALB/cA-nu,scid) seemed to exhibit the most consistent seweating response to local pharmacological stimulation. According to histological examination, eccrine sweat glands were preserved in human skin trasplanted into the back skin of the BALB/cA-nu,scid mouse strain. the heterologous, human skin graft provides a novel model permitting, independent of the normal sweat gland innervation, the analysis of moecular receptors of sweat gland cells by which the actions of natural transmitters and pharmacological agents are transduced.  相似文献   

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This paper reviews the approach to forecasting based on the construction of ARIMA time series models. Recent developments in this area are surveyed, and the approach is related to other forecasting methodologies.  相似文献   

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A persistent question about the deBroglie–Bohm interpretation of quantum mechanics concerns the understanding of Born's rule in the theory. Where do the quantum mechanical probabilities come from? How are they to be interpreted? These are the problems of emergence and interpretation. In more than 50 years no consensus regarding the answers has been achieved. Indeed, mirroring the foundational disputes in statistical mechanics, the answers to each question are surprisingly diverse. This paper is an opinionated survey of this literature. While acknowledging the pros and cons of various positions, it defends particular answers to how the probabilities emerge from Bohmian mechanics and how they ought to be interpreted.  相似文献   

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Zusammenfassung Im vorliegenden Aufsatz wird über die Ergebnisse immunologischer und immunochemischer Untersuchungen der Oberfl?chenstrukturen der Eier einiger mediterraner Seeigelarten berichtet. Die Eier werden Antiserum ausgesetzt, das durch Einspritzungen von Seeigel-Gametenmaterial in Kaninchen gewonnen wurde. So erh?lt man eine Reihe mikroskopisch sichtbarer, artspezifischer Antwortreaktionen. Normales Kaninchenserum ist unwirksam. Durch das vergleichende Studium der Aktivit?t verschiedener Antiseren, sowie durch die Antiserum-Hemmtechnik wurden bis jetzt vier voneinander verschiedene Oberfl?chenantigene bei den Eiern vonParacentrotus lividus festgestellt. Mindestens zwei der gefundenen Antigene haben Polysaccharid-Charakter. Die Reaktionen zwischen einem bestimmten Antik?rper und dessen Antigen, das A-Antigen genannt wurde, k?nnen interessanterweise zur parthenogenetischen Aktivierung unbefruchteter Eier führen. Andere Antigen-Antik?rperreaktionen k?nnen Befruchtung und Entwicklung der Eier hemmen. Die m?gliche Bedeutung der verschiedenen Antigene für das Festsetzen der Spermien an der Oberfl?che der Eier sowie für den Beginn der Ei-Aktivierung wird besprochen.   相似文献   

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The vault complex   总被引:2,自引:0,他引:2  
Vaults are large ribonucleoprotein particles found in eukaryotic cells. They are composed of multiple copies of a M r 100,000 major vault protein and two minor vault proteins of M r 193,000 and 240,000, as well as small untranslated RNAs of 86–141 bases. The vault components are arranged into a highly characteristic hollow barrel-like structure of 35 × 65 nm in size. Vaults are predominantly localized in the cytoplasm where they may associate with cytoskeletal elements. A small fraction of vaults are found to be associated with the nucleus. As of yet, the precise cellular function of the vault complex is unknown. However, their distinct morphology and intracellular distribution suggest a role in intracellular transport processes. Here we review the current knowledge on the vault complex, its structure, components and possible functions.Received 23 January 2003; received after revision 13 March 2003; accepted 26 March 2003  相似文献   

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The analytical notions of ‘thought style’, ‘paradigm’, ‘episteme’ and ‘style of reasoning’ are some of the most popular frameworks in the history and philosophy of science. Although their proponents, Ludwik Fleck, Thomas Kuhn, Michel Foucault, and Ian Hacking, are all part of the same philosophical tradition that closely connects history and philosophy, the extent to which they share similar assumptions and objectives is still under debate. In the first part of the paper, I shall argue that, despite the fact that these four thinkers disagree on certain assumptions, their frameworks have the same explanatory goal – to understand how objectivity is possible. I shall present this goal as a necessary element of a common project -- that of historicising Kant's a priori. In the second part of the paper, I shall make an instrumental use of the insights of these four thinkers to form a new model for studying objectivity. I shall also propose a layered diagram that allows the differences between the frameworks to be mapped, while acknowledging their similarities. This diagram will show that the frameworks of style of reasoning and episteme illuminate conditions of possibility that lie at a deeper level than those considered by thought styles and paradigms.  相似文献   

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Résumé Chez les cailles japonaises, le complexe glandulaire du cloaque est en fait localisé dans la lèvre dorsale du cloaque et non de l'anus. Il existe un complexe glandulaire similaire et très petit du côté ventral. La glande active se colore intensément avec le réactif périodique «acide Schiff», avec la fuchsine aldéhyde, avec le bleu d'alciane et métachromatiquement avec le bleu de toluidine. Ceci indique la présence d'une sécrétion de glycomucoprotéines. Le liquide transparent sécrété est transformé en masse blanche mousseuse au contact des bactériesE. coli etProteus mirabilis, présentes en quantités équivalentes dans le proctodeum. Les gaz émis consistent probablement en H2 et CO2, ce dernier peut agir comme tampon et stabiliser le pH de la sécrétion autour de la valeur 6,5.

This work was supported by U.S.P.H.S. grant No. ES 00054, Support for Toxicology Center, and by NASA research grant No. NGR 05-004-028.  相似文献   

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Two letters from William Burnside have recently been found in the Nachlass of Robert Fricke that contain instances of the Burnside Problem prior to its first publication. We present these letters as a whole to the public for the first time. We draw a picture of these two mathematicians and describe their activities leading to their correspondence. We thus gain an insight into their respective motivations, reactions, and attitudes, which may sharpen the current understanding of professional and social interactions of the mathematical community at the turn of the twentieth century. Dedicated to Heiko Harborth on the occasion of his seventieth birthday.  相似文献   

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Drawing on literature on values in science and a case-study of UK cancer policy, this paper argues for a novel account of the demarcation project in terms of trustworthiness. The first part of the paper addresses the relationship between science, politics and demarcation. In 2010, the UK government decided to pay more for cancer drugs than for drugs for other diseases; in 2016, this Cancer Drugs Fund was reformed so as to lower the evidential standards for approving cancer drugs, rather than paying more for them. Are these two ways of treating cancer as “special” importantly different? This paper argues that, if we the argument from inductive risk seriously, they seem equivalent. This result provides further reason to doubt the notion of demarcating science from non-science. However, the second part of the paper complicates this story, arguing that considerations of epistemic trust might give us reasons to prefer epistemic communities centred around “broadly acceptable” standards, and which are “sociologically well-ordered”, regardless of inductive risk concerns. After developing these claims through the cancer case-study, the final section suggests how these concerns might motivate novel versions of the demarcation project.  相似文献   

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This paper examines the anti-psychologism of Paul Natorp, a Marburg School Neo-Kantian. It identifies both Natorp’s principle argument against psychologism and the views underlying the argument that give it its force. Natorp’s argument depends for its success on his view that certain scientific laws constitute the intersubjective content of knowledge. That view in turn depends on Natorp’s conception of subjectivity, so it is only against the background of his conception of subjectivity that his reasons for rejecting psychologism make sense. This interpretation of Natorp suggests that attention paid to late nineteenth century theories of subjectivity and philosophy of psychology could improve our understanding of the emergence of anti-psychologism in that period.  相似文献   

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Meiosis is a key cellular and molecular process for sexual reproduction contributing to the genetic variability of organisms. This process takes place after DNA replication and consists in a double cellular division, giving rise to four haploid daughter cells or gametes. Meiotic recombination between homologous chromosomes, in the meiotic prophase I, is mediated by a tripartite structure named Synaptonemal Complex (SC). The SC is a peptidic scaffold in which the chromatin of homologous chromosomes is organized during the pachytene stage, holding chromosomes together until the meiotic recombination and genetic exchange have taken place. The role of chromatin structure in formation of the SC and the meiotic recombination at meiotic prophase I remain largely unknown. In this review we address the epigenome contribution to the SC formation at meiotic prophase I, with particular attention on the chromatin structure modifications occurring during the sub-stages of meiotic prophase I. Received 18 September 2008; received after revision 10 October 2008; accepted 24 October 2008  相似文献   

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