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1.
Hist Sci ; 58(4): 417-436, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32588656

RESUMO

Pseudonymous mathematician Nicolas Bourbaki and his lesser-known counterpart E.S. Pondiczery, devised respectively in France and in Princeton in the mid-1930s, together index a pivotal moment in the history of modern mathematics, marked by international infrastructures and institutions that depended on mathematicians' willingness to play along with mediated personifications. By pushing these norms and practices of personification to their farcical limits, Bourbaki's and Pondiczery's impersonators underscored the consensual social foundations of legitimate participation in a scientific community and the symmetric fictional character of both fraud and integrity in scientific authorship. To understand authorial identity and legitimacy, individual authors' conduct and practices matter less than the collective interpersonal relations of authorial assertion and authentication that take place within disciplinary institutions.

2.
Nature ; 553(7688): 271-273, 2018 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-29345675
3.
Nature ; 553(7688): 271-273, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32094640
4.
Clin Biochem ; 49(3): 248-52, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26601570

RESUMO

BACKGROUND: According to the prevailing theory about the genetic background to lactose intolerance, there are three genotypes but only two adult physiological phenotypes: lactase persistence in individuals with the CT and TT genotypes and lactase non-persistence in individuals with the CC genotype. However, analysis of lactase activity from intestinal biopsies has revealed three distinct levels of activity, suggesting that an intermediate physiological phenotype may exist. AIM: To assess possible disparities between different genotypes with regard to biomarkers of lactase activity and physical symptoms during an oral lactose load test. METHODS: A retrospective study using an oral lactose load test (n=487). Concentrations of hydrogen in exhaled air and blood glucose were measured. Afterwards, subjects were asked to provide oral mucosa samples for genotyping and answer a questionnaire (participation rate 56%, n=274). RESULTS: Mean hydrogen levels in exhaled air at 120min were significantly higher in the CT genotype than in the TT genotype. There was no significant difference in blood glucose levels between the two groups. Reported symptoms, with the possible exception of abdominal pain, were equally prevalent in both groups. CONCLUSIONS: Subjects with the CT and TT genotypes, hitherto classified as lactase-persistent, differ in their physiological response to lactose intake, indicating differences in phenotype which could have clinical significance.


Assuntos
Lactase/metabolismo , Intolerância à Lactose/genética , Dor Abdominal/enzimologia , Dor Abdominal/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Biomarcadores/sangue , Feminino , Genótipo , Humanos , Lactase/genética , Intolerância à Lactose/enzimologia , Teste de Tolerância a Lactose , Masculino , Pessoa de Meia-Idade , Fenótipo , Polimorfismo de Nucleotídeo Único , Prevalência , Estudos Retrospectivos , beta-Galactosidase/genética
5.
Br J Hist Sci ; 47(173 Pt 2): 239-55, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24941733

RESUMO

This paper identifies 'savage numbers'--number-like or number-replacing concepts and practices attributed to peoples viewed as civilizationally inferior--as a crucial and hitherto unrecognized body of evidence in the first two decades of the Victorian science of prehistory. It traces the changing and often ambivalent status of savage numbers in the period after the 1858-1859 'time revolution' in the human sciences by following successive reappropriations of an iconic 1853 story from Francis Galton's African travels. In response to a fundamental lack of physical evidence concerning prehistoric men, savage numbers offered a readily available body of data that helped scholars envisage great extremes of civilizational lowliness in a way that was at once analysable and comparable, and anecdotes like Galton's made those data vivid and compelling. Moreover, they provided a simple and direct means of conceiving of the progressive scale of civilizational development, uniting societies and races past and present, at the heart of Victorian scientific racism.


Assuntos
Antropologia Cultural/história , Historiografia , Civilização , Evolução Cultural , História do Século XIX , História do Século XX , Reino Unido
6.
J Am Chem Soc ; 127(2): 508-9, 2005 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-15643859

RESUMO

The 1,2,4-dithiazolidine-3,5-dione heterocycle, also referred to as a dithiasuccinoyl (Dts)-amine, serves as a readily removable amino protecting group for building blocks used in syntheses of peptides, glycopeptides, and PNA; it is also useful as a masked isocyanate and (inversely) as a sulfurization reagent for trivalent phosphorus. Bis(chlorocarbonyl)disulfane, the two-sulfur analogue of succinyl chloride, has been envisioned as a reagent for facile single-step elaboration of the heterocycle. However, reactions of bis(chlorocarbonyl)disulfane directly with primary amines fail to yield Dts-amines for reasons that are discussed. Inspired by several precedents from the organosilicon chemistry literature that a trimethylsilyl group may serve as a "large proton," a successful, high-yield preparation of Dts-amines through reactions of bis(chlorocarbonyl)disulfane with bis(trimethylsilyl)amines has been developed. Studies aimed at elucidating mechanistic reasons for these observations are also presented.


Assuntos
Aminas/química , Aminas/síntese química , Compostos de Enxofre/química , Tiazolidinedionas/síntese química , Compostos de Trimetilsilil/química
7.
Am J Physiol Heart Circ Physiol ; 286(4): H1394-401, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15020303

RESUMO

In the rat heart the actin-bound nucleotide contained both ATP and ADP. The ratio of bound ATP to bound ADP depended on the functional state of the heart; it was higher in hearts stopped reversibly in diastole (low Ca(2+), high Mg(2+), or high K(+)), than in stimulated (inotropic agents or pacing) hearts. Immunoblotting and gel electrophoresis showed the existence of G-actin (30% of total actin) in the cytoplasm of the heart. Pure actin was isolated from rat hearts: in G-actin the bound nucleotide readily exchanged with ATP or ADP, and in F-actin the bound nucleotide did not exchange with ATP or ADP. The free and bound nucleotides were separated in the intact heart by extraction with 75% methanol at -15 degrees C. In rat hearts perfused with (32)P-labeled orthophosphate the actin-bound nucleotide rapidly exchanged with the cytoplasmic ATP. The full exchange of the bound ATP was immediate, whereas the full exchange of the bound ADP was slower. The full exchange of the bound ATP was independent of the heartbeat frequency, whereas the full exchange of the bound ADP was frequency dependent. The data suggest that the transformation of actin monomer-ATP to actin polymer-ADP is a part of the normal contraction-relaxation cycle of the rat heart.


Assuntos
Actinas/metabolismo , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Miocárdio/metabolismo , Actinas/química , Animais , Citosol/metabolismo , Eletroforese em Gel de Poliacrilamida , Frequência Cardíaca/fisiologia , Técnicas In Vitro , Cinética , Masculino , Mitocôndrias Cardíacas/metabolismo , Miofibrilas/metabolismo , Tamanho do Órgão/fisiologia , Ratos , Ratos Sprague-Dawley , Viscosidade
8.
Biophys Chem ; 100(1-3): 177-82, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12646364

RESUMO

The paper of Edsall and Mehl, 'The effect of denaturing agents on myosin, II. Viscosity and double refraction of flow', J. Biol. Chem. 133 (1940) 409-429, inspired our research on actin and actomyosin. It led to the specific purification of actin with magnesium ions and to the demonstration of the central role of the Mg(2+)-activated actomyosin ATPase in contraction of live muscle.


Assuntos
Actinas/história , Actomiosina/história , Actinas/fisiologia , Actomiosina/fisiologia , Adenosina Trifosfatases/metabolismo , Bioquímica/história , História do Século XX , Magnésio/fisiologia , Contração Muscular/fisiologia
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