919 resultados para Screen Size
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Objective-Inflammation and proteolysis crucially contribute to myocardial ischemia and reperfusion injury. The extracellular matrix metalloproteinase inducer EMMPRIN (CD147) and its ligand cyclophilin A (CyPA) may be involved in both processes. The aim of the study was to characterize the role of the CD147 and CyPA interplay in myocardial ischemia/reperfusion (I/R) injury.Methods and Results-Immunohistochemistry showed enhanced expression of CD147 and CyPA in myocardial sections from human autopsies of patients who had died from acute myocardial infarction and from mice at 24 hours after I/R. At 24 hours and 7 days after I/R, the infarct size was reduced in CD147(+/-) mice vs CD147(+/+) mice (C57Bl/6), in mice (C57Bl/6) treated with monoclonal antibody anti-CD147 vs control monoclonal antibody, and in CyPA(-/-) mice vs CyPA(+/+) mice (129S6/SvEv), all of which are associated with reduced monocyte and neutrophil recruitment at 24 hours and with a preserved systolic function at 7 days. The combination of CyPA(-/-) mice with anti-CD147 treatment did not yield further protection compared with either inhibition strategy alone. In vitro, treatment with CyPA induced monocyte chemotaxis in a CD147-and phosphatidylinositol 3-kinase-dependent manner and induced monocyte rolling and adhesion to endothelium (human umbilical vein endothelial cells) under flow in a CD147-dependent manner.Conclusion-CD147 and its ligand CyPA are inflammatory mediators after myocardial ischemia and reperfusion and represent potential targets to prevent myocardial I/R injury.
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Insulin controls glucose homeostasis by regulating glucose use in peripheral tissues, and its own production and secretion in pancreatic beta cells. These responses are largely mediated downstream of the insulin receptor substrates, IRS-1 and IRS-2 (refs 4-8), through distinct signalling pathways. Although a number of effectors of these pathways have been identified, their roles in mediating glucose homeostasis are poorly defined. Here we show that mice deficient for S6 kinase 1, an effector of the phosphatidylinositide-3-OH kinase signalling pathway, are hypoinsulinaemic and glucose intolerant. Whereas insulin resistance is not observed in isolated muscle, such mice exhibit a sharp reduction in glucose-induced insulin secretion and in pancreatic insulin content. This is not due to a lesion in glucose sensing or insulin production, but to a reduction in pancreatic endocrine mass, which is accounted for by a selective decrease in beta-cell size. The observed phenotype closely parallels those of preclinical type 2 diabetes mellitus, in which malnutrition-induced hypoinsulinaemia predisposes individuals to glucose intolerance.
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Las estructuras de tamaño y edad de dos bosques monoespecificos subalpinos de Pinus uncinata en el Pirineo, fueron estudiadas e interpretadas introduciendo una clasificación sencilla de los árboles según la exposición de su copa a la radiación solar directa. Ambas poblaciones muestran distribuciones de diámetro de J invertida irregulares, cuya Interpretación es incierta. Por el contrario, la estructura de edad en ambos bosques muestra picos visibles, los cuales, si se tienen en cuenta la exposición de la copa, indican que la regeneración se produce en claros del bosque. Se analizaron las series de anillos de crecimiento de los árboles de cada sitio para reconstruir su historia reciente de perturbaciones Identificando los incrementos bruscos del crecimiento. El régimen de perturbaciones en los dos bosques es diferente, y en ambos casos muestra un efecto madelador análogo sobre la estructura de edad. Se concluye que P. uncinata se comporta como una especie heliófila que puede formar bosques maduros o multicohorte bajo determinados regímenes de perturbaciones suaves, gracias a su capacidad para iniciar la regeneración en claros pequeños. Este proceso tiene lugar en un lapso de tiempo corto después de la incidencia de las perturbaciones.
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In the vast majority of bottom-up proteomics studies, protein digestion is performed using only mammalian trypsin. Although it is clearly the best enzyme available, the sole use of trypsin rarely leads to complete sequence coverage, even for abundant proteins. It is commonly assumed that this is because many tryptic peptides are either too short or too long to be identified by RPLC-MS/MS. We show through in silico analysis that 20-30% of the total sequence of three proteomes (Schizosaccharomyces pombe, Saccharomyces cerevisiae, and Homo sapiens) is expected to be covered by Large post-Trypsin Peptides (LpTPs) with M(r) above 3000 Da. We then established size exclusion chromatography to fractionate complex yeast tryptic digests into pools of peptides based on size. We found that secondary digestion of LpTPs followed by LC-MS/MS analysis leads to a significant increase in identified proteins and a 32-50% relative increase in average sequence coverage compared to trypsin digestion alone. Application of the developed strategy to analyze the phosphoproteomes of S. pombe and of a human cell line identified a significant fraction of novel phosphosites. Overall our data indicate that specific targeting of LpTPs can complement standard bottom-up workflows to reveal a largely neglected portion of the proteome.
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This article explores the case of Barcelona as paradigmatic global city in such transnational productions as Vicky Cristina Barcelona by Woody Allen (2008) and Biutiful by Alejandro González Iñárritu (2010). Allen"s film shows the extreme dilution that national and linguistic identity undergoes under foreign eyes in its rendition of a"hip Barcelona" for tourists"invaded" by transnational subjects in search of bourgeois pleasures. Maybe in pursuit of a more"real" city, Iñárritu"s Biutiful moves to the Barcelona of the immigrants and the undocumented, a transnational and paradoxical location inhabited by those who need to cross borders in order to survive. Through reference to the work of Manuel Castells, Saskia Sassen, Neil Smith and Michel De Certeau among others, we argue that neither of these representations of the city is more real or unreal than the other. In their drastically divergent ways, both films contribute their external perspectives to the imaginary construction of Barcelona as a fascinating global city and can be seen as a dyptich of a transnational Barcelona. Further, they contribute to the ongoing debate about the polarization between the local and the global, the construction of urban boarders inside cities through gentrification, the transformation of the places we (would like to) inhabit, and the translation of all these into visual terms.
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In social animals, body size can be shaped by multiple factors, such as direct genetic effects, maternal effects, or the social environment. In ants, the body size of queens correlates with the social structure of the colony: colonies headed by a single queen (monogyne) generally produce larger queens that are able to found colonies independently, whereas colonies headed by multiple queens (polygyne) tend to produce smaller queens that stay in their natal colony or disperse with workers. We performed a cross-fostering experiment to investigate the proximate causes of queen size variation in the socially polymorphic ant Formica selysi. As expected if genetic or maternal effects influence queen size, eggs originating from monogyne colonies developed into larger queens than eggs collected from polygyne colonies, be they raised by monogyne or polygyne workers. In contrast, eggs sampled in monogyne colonies were smaller than eggs sampled in polygyne colonies. Hence, eggs from monogyne colonies are smaller but develop into larger queens than eggs from polygyne colonies, independently of the social structure of the workers caring for the brood. These results demonstrate that a genetic polymorphism or maternal effect transmitted to the eggs influences queen size, which probably affects the social structure of new colonies.
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OBJECTIVE: Accuracy studies of Patient Safety Indicators (PSIs) are critical but limited by the large samples required due to low occurrence of most events. We tested a sampling design based on test results (verification-biased sampling [VBS]) that minimizes the number of subjects to be verified. METHODS: We considered 3 real PSIs, whose rates were calculated using 3 years of discharge data from a university hospital and a hypothetical screen of very rare events. Sample size estimates, based on the expected sensitivity and precision, were compared across 4 study designs: random and VBS, with and without constraints on the size of the population to be screened. RESULTS: Over sensitivities ranging from 0.3 to 0.7 and PSI prevalence levels ranging from 0.02 to 0.2, the optimal VBS strategy makes it possible to reduce sample size by up to 60% in comparison with simple random sampling. For PSI prevalence levels below 1%, the minimal sample size required was still over 5000. CONCLUSIONS: Verification-biased sampling permits substantial savings in the required sample size for PSI validation studies. However, sample sizes still need to be very large for many of the rarer PSIs.
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Lynch's (1980a) optimal-body-size model is designed to explain some major trends in cladoceran life histories; in particular the fact that large and littoral species seem to be bang-bang strategists (they grow first and the reproduce) whereas smaller planktonic species seem to be intermediate strategists (they grow and reproduce simultaneously). Predation is assumed to be an important selective pressure for these trends. Simocephalus vetulus (Müller) does not fit this pattern; being a littoral and relatively large species but an intermediate strategist. As shown by computer simulations, this species would reduce its per capita rate of increase by adopting the strategy predicted by the optimal-body-size model. Two aspects of the model are criticized: (1) the optimization criterion is shown to be incorrect and (2) the prediction of an intermediate strategy is not justified. Structural constraints are suggested to be responsible for the intermediate strategy of S.vetulus. Biotic interactions seem to have little effect on the observed life-history patterns of this species.
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An experiment was conducted to determine the fruit size, mineral composition and quality of trickle-irrigated tomatoes as affected by potassium fertilizer rates. Six potassium (K) rates were applied as KCl, corresponding to 0, 48.4, 118.6, 188.8, 259.0 and 399.4 kg ha-1, with four replicates, following a randomized block design. Quadratic responses to K rates were observed for double extra large (diameter > 60 mm), extra large (56 to 60 mm) and large (52 to 56 mm) fruit yields. Maximum yields of these classes were achieved with K rates of 116, 190 and 233 kg ha-1, respectively. Fruit dry matter, phosphorus, sulfur and magnesium contents were not affected by K rates, but nitrate and K contents showed significant increments as K rates were increased. Vitamin C, total soluble solids, lycopene and beta-carotene contents in the fruits were not affected by K rates. Increments in the K rate lowered the fruit pH and increased total acids content.
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Abstract Island biogeography has provided fundamental hypotheses in population genetics, ecology and evolutionary biology. Insular populations usually face different feeding conditions, predation pressure, intraspecific and interspecific competition than continental populations. This so-called island syndrome can promote the evolution of specific phenotypes like a small (or large) body size and a light (or dark) colouration as well as influence the evolution of sexual dimorphism. To examine whether insularity leads to phenotypic differentiation in a consistent way in a worldwide-distributed nonmigratory species, we compared body size, body shape and colouration between insular and continental barn owl (Tyto alba) populations by controlling indirectly for phylogeny. This species is suitable because it varies in pheomelanin-based colouration from reddish-brown to white, and it displays eumelanic black spots for which the number and size vary between individuals, populations and species. Females are on average darker pheomelanic and display more and larger eumelanic spots than males. Our results show that on islands barn owls exhibited smaller and fewer eumelanic spots and lighter pheomelanic colouration, and shorter wings than on continents. Sexual dimorphism in pheomelanin-based colouration was less pronounced on islands than continents (i.e. on islands males tended to be as pheomelanic as females), and on small islands owls were redder pheomelanic and smaller in size than owls living on larger islands. Sexual dimorphism in the size of eumelanic spots was more pronounced (i.e. females displayed much larger spots than males) in barn owls living on islands located further away from a continent. Our study indicates that insular conditions drive the evolution towards a lower degree of eumelanism, smaller body size and affects the evolution of sexual dichromatism in melanin-based colour traits. The effect of insularity was more pronounced on body size and shape than on melanic traits.
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Sexual selection in lek-breeding species might drastically lower male effective population size, with potentially important consequences for evolutionary and conservation biology. Using field-monitoring and parental-assignment methods, we analyzed sex-specific variances in breeding success in a population of European treefrogs, to (1) help understanding the dynamics of genetic variance at sex-specific loci, and (2) better quantify the risk posed by genetic drift in this species locally endangered by habitat fragmentation. The variance in male mating success turned out to be markedly lower than values obtained from other amphibian species with polygamous mating systems. The ratio of effective breeding size to census breeding size was only slightly lower in males (0.44) than in females (0.57), in line with the patterns of genetic diversity previously reported from H. arborea sex chromosomes. Combining our results with data on age at maturity and adult survival, we show that the negative effect of the mating system is furthermore compensated by the effect of delayed maturity, so that the estimated instantaneous effective size broadly corresponded to census breeding size. We conclude that the lek-breeding system of treefrogs impacts only weakly the patterns of genetic diversity on sex-linked genes and the ability of natural populations to resist genetic drift.
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Effect size indices are indispensable for carrying out meta-analyses and can also be seen as an alternative for making decisions about the effectiveness of a treatment in an individual applied study. The desirable features of the procedures for quantifying the magnitude of intervention effect include educational/clinical meaningfulness, calculus easiness, insensitivity to autocorrelation, low false alarm and low miss rates. Three effect size indices related to visual analysis are compared according to the aforementioned criteria. The comparison is made by means of data sets with known parameters: degree of serial dependence, presence or absence of general trend, changes in level and/or in slope. The percent of nonoverlapping data showed the highest discrimination between data sets with and without intervention effect. In cases when autocorrelation or trend is present, the percentage of data points exceeding the median may be a better option to quantify the effectiveness of a psychological treatment.
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This study explores the impact of relative size on the intra- and intergroup attitudes of groups who either share a language or have a different language. For that purpose, we examined international attitudes, comparing a small nation, Switzerland, and two larger nations, Germany and France. We found support for the assumption that large neighbouring nations pose a threat to the smaller nation's identity, especially when they are linguistically similar. Consequently, in line with Tajfel's Social Identity Theory (1978), the smaller nation's inhabitants evaluate those of the larger nation less positively, liking them less and perceiving them to be more arrogant than vice versa. By investigating the special case of the French-speaking and the German-speaking Swiss as linguistic groups within their own nation we were able to demonstrate that these groups seek support with the larger-linguistically-similar nation to defend themselves against the more direct in-country threat to their identity. They acknowledge the similarity with the larger nation, yet keep defending their social identity by expressing a dislike for this perceived similarity.
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In terrestrial snakes, many cases of intraspecific shifts in dietary habits as a function of predator sex and body size are driven by gape-limitation - and hence, are most common in species that feed on relatively large prey, and exhibit a wide body-size range. Our data on seasnakes reveal an alternative mechanism for intraspecific niche partitioning, based on sex-specific seasonal anorexia induced by reproductive activities. Turtle-headed seasnakes (Emydocephalus annulatus) on coral reefs in the New Caledonian Lagoon feed entirely on the eggs of demersal-spawning fishes. DNA sequence data (cytochrome b gene) on eggs that we palpated from stomachs of 37 snakes showed that despite this ontogenetic-stage specialization, the prey come from a taxonomically diverse array of species including damselfish (41% of samples, at least 5 species), blennies (41%, 4 species) and gobies (19%, 5 species). The composition of snake diets shifted seasonally (with damselfish dominating in winter but not summer), presumably reflecting seasonality of fish reproduction. That seasonal shift affects male and female snakes differently, because reproduction is incompatible with foraging. Adult female seasnakes ceased feeding when they became heavily distended with developing embryos in late summer, and males ceased feeding while they were mate-searching in winter. The sex divergence in foraging habits may be amplified by sexual size dimorphism; females grow larger than males, and larger snakes (of both sexes) feed more on damselfish (which often lay their eggs in exposed sites) than on blennies and gobies (whose eggs are hidden within narrow crevices). Specific features of reproductive biology of coral-reef fish (seasonality and nest type) have generated intraspecific niche partitioning in these seasnakes, by mechanisms different from those that apply to terrestrial snakes.