Collaborative explanation,explanatory roles,and scientific explaining in practice

Scientific explanation is a perennial topic in philosophy of science, but the literature has fragmented into specialized discussions in different scientific disciplines. An increasing attention to scientific practice by philosophers is (in part) responsible for this fragmentation and has put pressure on criteria of adequacy for philosophical accounts of explanation, usually demanding some form of pluralism. This commentary examines the arguments offered by Fagan and Woody with respect to explanation and understanding in scientific practice. I begin by scrutinizing Fagan's concept of collaborative explanation, highlighting its distinctive advantages and expressing concern about several of its assumptions. Then I analyze Woody's attempt to reorient discussions of scientific explanation around functional considerations, elaborating on the wider implications of this methodological recommendation. I conclude with reflections on synergies and tensions that emerge when the two papers are juxtaposed and how these draw attention to critical issues that confront ongoing philosophical analyses of scientific explanation.     

Melanocyte-stimulating hormone and learned appetitive behavior

Résumé Cette étude indique que l'administration de MSH aux rats les fait retenir une tâche appétitive. Un effet sur la persévération ou la mémoire est impliqué.     

Radiation induced avoidance behavior transfer by brain extracts of mice

Zusammenfassung In «naiven» Mäusen werden Verhaltensveränderungen nach Injektion kleiner Mengen von Gehirnmaterial aus Saccharin bevorzugenden und röntgenbestrahlten Mäusen beobachtet. Es trat Vermeidung der Saccharinlösung ein, und zwar ähnlich wie sonst in «trainierten», Saccharin bevorzugenden Tieren nach der Bestrahlung.     

On the relationship between wool quality and the type and concentration of blood potassium in sheep

Résumé Dans le sang des moutons, la fréquence des gènes du type LK est en relation linéaire inversément proportionelle à l'épaisseur de la fibre de laine. Il en va de mÊme pour le degré de concentration du potassium. En se basant sur ces observations, les auteurs envisagent la possibilité d'améliorer la qualité de la laine ordinaire.     

1-14C-acetyl-coenzyme A as steroid precursor in the monkey adrenal in vitro

Zusammenfassung Nach In-vitro-Inkubation von Nebennierenschnitten eines Rhesusaffen mit 1-¹⁴C-acetyl-CoA und 7 -³H-Pregnenolon konnte man Pregnenolon, DHEA und Progesteron isolieren, die alle sowohl³H-als auch¹⁴C-Aktivität enthielten. Es ergaben sich Hinweise für verschiedene Biosynthesewege für Pregnenolon und DHEA.     

The effects of prostaglandin E1 on the systemic and pulmonary circulations of intact dogs. The influence of urethane and pentobarbital anesthesia

Zusammenfassung Es wird gezeigt, dass Phenobarbital- und Urethan-Anästhesie nach Infusion von PGE₁ in den Kreislauf normaler Hunde verschiedene hämodynamische Reaktionen (Herzminutenvolumen, Herzfrequenz, Durchblutung der Peripherie) verursacht.Die Intrakoronarinfusion von PGE₁ mit der Narkose ergab einen negativ chronotropen und einen negativ inotropen Effekt.

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Supported by grants No. HE-06769 from the National Heart Institutes of the U.S. Public Health Service, the Rudolph Matas Memorial Fund for the Kate Prewitt Hess Laboratory and the Rowell A. Billups Fund for Research in Heart Disease.     

Alkaloids ofBerberis laurina Billb. II. Two new phenolic biscoclaurine alkaloids

Zusammenfassung Die Isolierung von zwei neuen dauricinartigen AlkaloÏden, Espinin and Espinidin, ausBerberis laurina, und deren Strukturaufklärung durch Spektroskopie und Degradation werden beschrieben.     

Surrénalite autoimmune expérimentale chez la souris

Summary In CF 1 mice, by injection of surrenalian tissue mixed with complete Freund's adjuvant, we have induced an immune surrenalitis with auto-antibodies. The lesions are maximal on day 15 but they are only transitory.

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Travail du Laboratorie d'Hygène, Faculté de Médecine de Lyon, service du ProfesseurThivolet.

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Avec l'aide technique de MlleGermain.     

Role of the ubiquitin–proteasome system in the regulation of P2Y13 receptor expression: impact on hepatic HDL uptake

The protective effect of high density lipoproteins (HDL) against atherosclerosis is mainly attributed to their capacity to transport excess cholesterol from peripheral tissues back to the liver for further elimination into the bile, a process called reverse cholesterol transport (RCT). Recently, the importance of the P2Y₁₃ receptor (P2Y₁₃-R) was highlighted in HDL metabolism since HDL uptake by the liver was decreased in P2Y₁₃-R deficient mice, which translated into impaired RCT. Here, we investigated for the first time the molecular mechanisms regulating cell surface expression of P2Y₁₃-R. When transiently expressed, P2Y₁₃-R was mainly detected in the endoplasmic reticulum (ER) and strongly subjected to proteasome degradation while its homologous P2Y₁₂ receptor (P2Y₁₂-R) was efficiently targeted to the plasma membrane. We observed an inverse correlation between cell surface expression and ubiquitination level of P2Y₁₃-R in the ER, suggesting a close link between ubiquitination of P2Y₁₃-R and its efficient targeting to the plasma membrane. The C-terminus tail exchange between P2Y₁₃-R and P2Y₁₂-R strongly restored plasma membrane expression of P2Y₁₃-R, suggesting the involvement of the intra-cytoplasmic tail of P2Y₁₃-R in expression defect. Accordingly, proteasomal inhibition increased plasma membrane expression of functionally active P2Y₁₃-R in hepatocytes, and consequently stimulated P2Y₁₃-R-mediated HDL endocytosis. Importantly, proteasomal inhibition strongly potentiated HDL hepatic uptake (>200 %) in wild-type but not in P2Y₁₃-R-deficient mice, thus reinforcing the role of P2Y₁₃-R expression in regulating HDL metabolism. Therefore, specific inhibition of the ubiquitin–proteasome system might be a novel powerful HDL therapy to enhance P2Y₁₃-R expression and consequently promote the overall RCT.