1000 resultados para 161-975C
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All higher plants possess multiple phytochrome photoreceptors, with phytochrome A (phyA) being light labile and other members of the family being relatively light stable (phyB-phyE in Arabidopsis [Arabidopsis thaliana]). phyA also differs from other members of the family because it enables plants to deetiolate in far-red light-rich environments typical of dense vegetational cover. Later in development, phyA counteracts the shade avoidance syndrome. Light-induced degradation of phyA favors the establishment of a robust shade avoidance syndrome and was proposed to be important for phyA-mediated deetiolation in far-red light. phyA is ubiquitylated and targeted for proteasome-mediated degradation in response to light. Cullin1 and the ubiquitin E3 ligase CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1) have been implicated in this process. Here, we systematically analyze the requirement of cullins in this process and show that only CULLIN1 plays an important role in light-induced phyA degradation. In addition, the role of COP1 in this process is conditional and depends on the presence of metabolizable sugar in the growth medium. COP1 acts with SUPPRESSOR OF PHYTOCHROME A (SPA) proteins. Unexpectedly, the light-induced decline of phyA levels is reduced in spa mutants irrespective of the growth medium, suggesting a COP1-independent role for SPA proteins.
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Kirje
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Wave-shaped ribs were detected at prenatal ultrasound in a 20(+1) week female fetus. At birth, skeletal radiographs showed marked hypomineralization and suggested hypophosphatasia. However, elevated blood calcium and alkaline phosphatase excluded hypophosphatasia and raised the possibility of Jansen metaphyseal dysplasia. Molecular analysis of the PTH/PTHrP receptor gene (PTH1R) showed heterozygosity for a previously undescribed transversion variant (c.1373T>A), which predicts p.Ile458Lys. In vitro evaluation of wild type and mutant PTH/PTHrP receptors supported the pathogenic role of the p.Ile458Lys substitution, and confirmed the diagnosis of Jansen metaphyseal dysplasia. This disorder may present prenatally with wavy ribs and in the newborn with hypomineralization, and may therefore be confused with hypophosphatasia. The mottled metaphyseal lesions typically associated with this disease appear only in childhood.
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Kirje 1.11.1973
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Fred Paccaud, professeur d'épidémiologie et de santé publique (Lausanne), réagit à la campagne de dénigrement menée en avril 2008 contre le directeur de l'Office fédéral de la santé publique et les campagnes de prévention.
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Kirje 13.11.1931
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This study describes a form of partial agonism for a CD8+ CTL clone, S15, in which perforin-dependent killing and IFN-gamma production were lost but Fas (APO1 or CD95)-dependent cytotoxicity preserved. Cloned S15 CTL are H-2Kd restricted and specific for a photoreactive derivative of the Plasmodium berghei circumsporozoite peptide PbCS 252-260 (SYIPSAEKI). The presence of a photoactivatable group in the epitope permitted assessment of TCR-ligand binding by TCR photoaffinity labeling. Selective activation of Fas-dependent killing was observed for a peptide-derivative variant containing a modified photoreactive group. A similar functional response was obtained after binding of the wild-type peptide derivative upon blocking of CD8 participation in TCR-ligand binding. The epitope modification or blocking of CD8 resulted in an > or = 8-fold decrease in TCR-ligand binding. In both cases, phosphorylation of zeta-chain and ZAP-70, as well as calcium mobilization were reduced close to background levels, indicating that activation of Fas-dependent cytotoxicity required weaker TCR signaling than activation of perforin-dependent killing or IFN-gamma production. Consistent with this, we observed that depletion of the protein tyrosine kinase p56(lck) by preincubation of S15 CTL with herbimycin A severely impaired perforin- but not Fas-dependent cytotoxicity. Together with the observation that S15 CTL constitutively express Fas ligand, these results indicate that TCR signaling too weak to elicit perforin-dependent cytotoxicity or cytokine production can induce Fas-dependent cytotoxicity, possibly by translocation of preformed Fas ligand to the cell surface.
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Social insects use multiple lines of collective defences to combat pathogens. One example of a behav- ioural group defence is the use of antimicrobial plant compounds to disinfect the nest. Indeed, wood ants collect coniferous tree resin, and the presence of resin in their nest protects them against fungal and bacterial pathogens. Many questions remain on the mechanisms of resin use, including which factors elicit resin collection and placement within nests. Here, we investigated whether the presence of brood induces Formica paralugubris workers to collect more resin, and whether the workers preferentially place resin near the brood. We also tested whether the collection and placement of resin depends on the presence of the fungal entomopathogen Beauveria bassiana. Workers brought more resin to their nest when brood was present, and preferentially placed the resin near the brood. In contrast, workers did not increase resin collection in response to exposure to B. bassiana, nor did they place resin closer to contaminated brood or contaminated areas of the nest. This lack of response may be explained by a limited effect of resin against the germination and growth of B. bassiana in vitro. Overall, our main result is that woods ants actively position resin near the brood, which probably confers prophylactic protection against other detrimental microorganisms.
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A temperatura exerce grande influência no desenvolvimento dos insetos e o conhecimento desse aspecto é essencial para subsidiar o uso de inimigos naturais como agentes de controle biológico, bem como para a sua criação massal. O presente trabalho teve como objetivo avaliar o efeito de diferentes temperaturas no desenvolvimento de Orius insidiosus (Say, 1832), bem como as suas exigências térmicas. O experimento foi conduzido em câmaras climáticas, a 16, 19, 22, 25, 28 e 31±1°C; UR de 70±10% e fotofase de 12 horas. Como alimento foram utilizados ovos de Anagasta kuehniella (Zeller, 1879). O período embrionário foi de 14,0; 8,9; 6,6; 4,8; 3,9 e 3,3 dias nas temperaturas de 16, 19, 22, 25, 28 e 31°C, respectivamente. Ninfas de todos os instares (independente do sexo que deram origem) foram influenciadas pela temperatura quanto ao seu desenvolvimento, com redução nesse período com o aumento da temperatura. Machos e fêmeas, na temperatura de 25°C, apresentaram um período de desenvolvimento em torno de 12 dias. A temperatura base da fase de ovo foi de 11,78°C e a da fase ninfal foi de 12,27°C e de 13,03°C, para machos e fêmeas, respectivamente. A constante térmica para a fase de ovo foi de 63,75 e para a fase de ninfa de 161,97 e 157,24 graus-dia, para machos e fêmeas, respectivamente. A temperatura de 25°C foi a mais adequada para o desenvolvimento de O. insidiosus.
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Migrants tend to present higher overweight and obesity levels, but whether this relationship applies to all nationalities has seldom been studied. The present study aimed to assess the prevalence of overweight and obesity according to nationality in adults. Cross-sectional population-based samples. Five-year nationwide interview surveys (Swiss Health Surveys - SHS) from 1992 to 2007 (n 63 766) and a local examination survey (CoLaus Study in Lausanne 2004-2006, n 6743). Participants were separated into Swiss, French, German, Italian, Portuguese, Spanish nationals, those from the former Republic of Yugoslavia and from other European and other countries. Compared with Swiss nationals, German and French nationals presented a lower prevalence of overweight and obesity, whereas nationals from Italy, Spain, Portugal and the former Republic of Yugoslavia presented higher levels. Adjusting the SHS data for age, gender, education, smoking, leisure-time physical activity and survey year, a lower risk for overweight and obesity was found for German (OR = 0·80, 95 % CI 0·70, 0·92) and French (OR = 0·74, 95 % CI 0·61, 0·89) nationals, whereas higher risks were found for participants from Italy (OR = 1·45, 95 % CI 1·33, 1·58), Spain (OR = 1·36, 95 % CI 1·15, 1·61), Portugal (OR = 1·25, 95 % CI 1·06, 1·47) and the former Republic of Yugoslavia (OR = 1·98, 95 % CI 1·69, 2·32). Similar findings were observed in the CoLaus Study for Italian (OR = 1·63, 95 % CI 1·29, 2·06), Spanish (OR = 1·54, 95 % CI 1·17, 2·04) and Portuguese (OR = 1·49, 95 % CI 1·16, 1·91) participants and for those from the former Republic of Yugoslavia (OR = 5·34, 95 % CI 3·00, 9·50). Overweight and obesity are unevenly distributed among migrants in Switzerland. Migrants from Southern Europe and from the former Republic of Yugoslavia present higher prevalence rates. This suggests that preventive messages should be tailored to these specific populations.
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Human decision-making has consistently demonstrated deviation from "pure" rationality. Emotions are a primary driver of human actions and the current study investigates how perceived emotions and personality traits may affect decision-making during the Ultimatum Game (UG). We manipulated emotions by showing images with emotional connotation while participants decided how to split money with a second player. Event-related potentials (ERPs) from scalp electrodes were recorded during the whole decision-making process. We observed significant differences in the activity of central and frontal areas when participants offered money with respect to when they accepted or rejected an offer. We found that participants were more likely to offer a higher amount of money when making their decision in association with negative emotions. Furthermore, participants were more likely to accept offers when making their decision in association with positive emotions. Honest, conscientious, and introverted participants were more likely to accept offers. Our results suggest that factors others than a rational strategy may predict economic decision-making in the UG.