939 resultados para Trait physiology


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Anuran amphibians exhibit different patterns of energy substrate utilization that correlate with the intensity of vocal and locomotor activities. Given the remarkable differences among species in breeding and feeding strategies, and the different ways energy is used in the whole animal, the suggested correlations between calling and locomotor behavior and the level of energy substrates in the muscles responsible for such activities are more complex than previously reported. We explored the relationships between calling and locomotor behavior and energy supply to trunk and hindlimb muscles, respectively, within the ecologically diverse tree-frog genus Scinax. Specifically, we measured the relative amount of carbohydrates and lipids in these two groups of muscles, and in the liver of three species of Scinax that differ in vocal and locomotor performance, and compared our results with those of two other species for which comparable data are available. We also compared the contents of lipids and carbohydrates of conspecific males collected at the beginning and after 4 h of calling activity. The stomach content to potential feeding opportunities across species was also assessed in both groups of males. Scinax hiemalis and S. rizibilis exhibit comparatively low and episodic calling during long periods of activity whereas S. crospedospilus calls at higher rates over shorter periods. Male S. hiemalis had highest levels of trunk muscle glycogen followed by those of S. rizilbilis and S. crospedospilus, respectively. There was no correlation between total lipid content in trunk muscle and calling rate among different species, suggesting that other metabolic aspects may be responsible for the energetic support for vocal activity. The levels of lipids and carbohydrates in trunk and hindlimb muscles and liver of males collected at the beginning and 4 h into the calling period were similar across species, so the extent of energetic reserves does not appear to constrain vocal or locomotor activity. Finally, we found exceptionally high levels of carbohydrates and lipids in the liver of S. rizibilis, a trait perhaps related to a long and demanding breeding period.

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With the aim of determining the genetic basis of metabolic regulation in tomato fruit, we constructed a detailed physical map of genomic regions spanning previously described metabolic quantitative trait loci of a Solanum pennellii introgression line population. Two genomic libraries from S. pennellii were screened with 104 colocated markers from five selected genomic regions, and a total of 614 bacterial artificial chromosome (BAC)/cosmids were identified as seed clones. Integration of sequence data with the genetic and physical maps of Solanum lycopersicum facilitated the anchoring of 374 of these BAC/cosmid clones. The analysis of this information resulted in a genome-wide map of a nondomesticated plant species and covers 10% of the physical distance of the selected regions corresponding to approximately 1% of the wild tomato genome. Comparative analyses revealed that S. pennellii and domesticated tomato genomes can be considered as largely colinear. A total of 1,238,705 bp from both BAC/cosmid ends and nine large insert clones were sequenced, annotated, and functionally categorized. The sequence data allowed the evaluation of the level of polymorphism between the wild and cultivated tomato species. An exhaustive microsynteny analysis allowed us to estimate the divergence date of S. pennellii and S. lycopersicum at 2.7 million years ago. The combined results serve as a reference for comparative studies both at the macrosyntenic and microsyntenic levels. They also provide a valuable tool for fine-mapping of quantitative trait loci in tomato. Furthermore, they will contribute to a deeper understanding of the regulatory factors underpinning metabolism and hence defining crop chemical composition.

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Purpose of review Description of the progress about the vascular effects promoted by thyroid hormones. Recent findings Over the past few years, a number of studies have shown that in addition to genomic effects on blood vessels, thyroid hormones exert extranuclear nongenomic effects on vascular smooth muscle cells and endothelium. These nongenomic effects occur rapidly and do not involve thyroid hormone response elements-mediated transcriptional events. In this context, the genomic and nongenomic events promoted by thyroid hormones act in concert to control the vascular hemodynamic and regulate the cardiovascular function. Summary Considering the antiatherogenic property of thyroid hormones and the rapid effects produced by this molecule as a vasodilator, including that in the coronary bed, a better understanding of the molecular mechanisms involved in its action may contribute to the development of drugs that can be clinically used to increase the known benefits promoted by thyroid hormones in cardiovascular physiology.

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Objective.- To assess urinary 6-sulphatoxymelatonin levels in a large consecutive series of patients with migraine and several comorbidities (chronic fatigue, fibromyalgia, insomnia, anxiety, and depression) as compared with controls. Background.- Urine analysis is widely used as a measure of melatonin secretion, as it is correlated with the nocturnal profile of plasma melatonin secretion. Melatonin has critical functions in human physiology and substantial evidence points to its importance in the regulation of circadian rhythms, sleep, and headache disorders. Methods.- Urine samples were collected into a single plastic container over a 12-hour period from 8:00 pm to 8:00 am of the next day, and 6-sulphatoxymelatonin was measured by quantitative ELISA. All of the patients were given a detailed questionnaire about headaches and additionally answered the following questionnaires: Chalder fatigue questionnaire, Epworth somnolence questionnaire, State-Trait Anxiety Inventory, and the Beck Depression Inventory. Results.- A total of 220 subjects were evaluated - 73 (33%) had episodic migraine, 73 (33%) had chronic migraine, and 74 (34%) were enrolled as control subjects. There was a strong correlation between the concentration of 6-sulphatoxymelatonin detected and chronic migraine. Regarding the comorbidities, this study objectively demonstrates an inverse relationship between 6-sulphatoxymelatonin levels and depression, anxiety, and fatigue. Conclusions.- To our knowledge, this is the first study to evaluate the relationship between the urinary concentration of melatonin and migraine comorbidities. These results support hypothalamic involvement in migraine pathophysiology.

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Background Anxiety related to dental treatment is a fairly common phenomenon. Some studies have shown that there is an association between dental anxiety and general fears and anxiety, neuroticism and general psychological distress. Aim This study was designed to examine the relationship between dental anxiety and trait anxiety. Subjects and methods The sample consisted of 1,030 individuals (688 women; 342 men), aged 30.8 +/- 11.7 years. The Portuguese version of Corah`s Dental Anxiety Scale (DAS) and State-Trait Anxiety Inventory (STAI-T) were used. Results A statistically significant association between high DAS and high STAI-T, but not between high STAI-T and high DAS, was found. The data indicated that subjects with high dental anxiety tend to present with high trait anxiety, but high trait anxiety seems not to predispose to high dental anxiety. Conclusions Our results indicate that dental anxiety is specific, with its own features, and its development is not necessarily associated with trait anxiety.

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Insect disease vectors show diminished fecundity when infected with Plasmodium. This phenomenon has already been demonstrated in laboratory models such as Aedes aegypti, Anopheles gambiae and Anopheles stephensi. This study demonstrates several changes in physiological processes of A. aegypti occurring upon infection with Plasmodium gallinaceum, such as reduced ecdysteroid levels in hemolymph as well as altered expression patterns for genes involved in vitellogenesis, lipid transport and immune response. Furthermore, we could show that P. gallinaceum infected A. aegypti presented a reduction in reproductive fitness, accompanied by an activated innate immune response and increase in lipophorin expression, with the latter possibly representing a nutritional resource for Plasmodium sporozoites. (C) 2010 Elsevier Ltd. All rights reserved.

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Sugarcane is an important crop that has recently become subject to attacks from the weevil Sphenophorus levis, which is not efficiently controlled with chemical insecticides. This demands the development of new control devices for which digestive physiology data are needed. In the present study, ion-exchange chromatography of S. levis whole midgut homogenates, together with enzyme assays with natural and synthetic substrates and specific inhibitors, demonstrated that a cysteine proteinase is a major proteinase, trypsin is a minor one and chymotrypsin is probably negligible. Amylase, maltase and the cysteine proteinase occur in the gut contents and decrease throughout the midgut; trypsin is constant in the entire midgut, whereas a membrane-bound aminopeptidase predominates in the posterior midgut. The cysteine proteinase was purified to homogeneity through ion-exchange chromatography. The purified enzyme had a mass of 37 kDa and was able to hydrolyze Z-Phe-Arg-MCA and Z-Leu-Arg-MCA with k(cat)/K(m) values of 20.0 +/- 1.1 mu M(-1) s(-1) and 30.0 +/- 0.5 mu M(-1) s(-1), respectively, but not Z-Arg-Arg-MCA. The combined results suggest that protein digestion starts in the anterior midgut under the action of a cathepsin L-like proteinase and ends on the surface of posterior midgut cells. All starch digestion takes place in anterior midgut. These data will be instrumental to developing S. levis-resistant sugarcane. (C) 2011 Elsevier Ltd. All rights reserved.

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This thesis develops and evaluates statistical methods for different types of genetic analyses, including quantitative trait loci (QTL) analysis, genome-wide association study (GWAS), and genomic evaluation. The main contribution of the thesis is to provide novel insights in modeling genetic variance, especially via random effects models. In variance component QTL analysis, a full likelihood model accounting for uncertainty in the identity-by-descent (IBD) matrix was developed. It was found to be able to correctly adjust the bias in genetic variance component estimation and gain power in QTL mapping in terms of precision.  Double hierarchical generalized linear models, and a non-iterative simplified version, were implemented and applied to fit data of an entire genome. These whole genome models were shown to have good performance in both QTL mapping and genomic prediction. A re-analysis of a publicly available GWAS data set identified significant loci in Arabidopsis that control phenotypic variance instead of mean, which validated the idea of variance-controlling genes.  The works in the thesis are accompanied by R packages available online, including a general statistical tool for fitting random effects models (hglm), an efficient generalized ridge regression for high-dimensional data (bigRR), a double-layer mixed model for genomic data analysis (iQTL), a stochastic IBD matrix calculator (MCIBD), a computational interface for QTL mapping (qtl.outbred), and a GWAS analysis tool for mapping variance-controlling loci (vGWAS).

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MAPfastR is a software package developed to analyze QTL data from inbred and outbred line-crosses. The package includes a number of modules for fast and accurate QTL analyses. It has been developed in the R language for fast and comprehensive analyses of large datasets. MAPfastR is freely available at: http://www.computationalgenetics.se/?page_id=7.

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Understanding the genetic basis of traits involved in adaptation is a major challenge in evolutionary biology but remains poorly understood. Here, we use genome-wide association mapping using a custom 50 k single nucleotide polymorphism (SNP) array in a natural population of collared flycatchers to examine the genetic basis of clutch size, an important life-history trait in many animal species. We found evidence for an association on chromosome 18 where one SNP significant at the genome-wide level explained 3.9% of the phenotypic variance. We also detected two suggestive quantitative trait loci (QTLs) on chromosomes 9 and 26. Fitness differences among genotypes were generally weak and not significant, although there was some indication of a sex-by-genotype interaction for lifetime reproductive success at the suggestive QTL on chromosome 26. This implies that sexual antagonism may play a role in maintaining genetic variation at this QTL. Our findings provide candidate regions for a classic avian life-history trait that will be useful for future studies examining the molecular and cellular function of, as well as evolutionary mechanisms operating at, these loci.

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Cette dissertation porte sur l’analyse syntactico-sémantique des verbes à trait de complexité. Le trait de complexité (Blanche-Benveniste et al. 1984) réunit une classe de verbes connue comme verbes ‘symétriques’, ‘réciproques’ ou ‘collectifs’ sans toutefois se limiter à ces ensembles (cf. grouiller, collectionner, amonceler, scinder, etc.). Ce trait induit une lecture ‘plurielle’ à l’entité formée du lexème verbal et de ses arguments et qui se traduit, sur le plan morphosyntaxique, par deux propriétés: sélection obligatoire d’une position syntaxique (sujet ou objet) au pluriel; en absence de ce pluriel morphologique, le trait de complexité se réalise par la sélection d’un complément prépositionnel correlié à une position syntaxique (sujet ou objet) et l’interprétation de ‘pluriel’ des deux éléments correliés. L’hypothèse générale, et point de départ de cette dissertation, consiste à préciser l’interprétation de ‘pluralité inhérente’ des verbes à trait de complexité comme étant de type ‘collectif’, défini comme désignant du ‘plus d’un en un’ (Jespersen, 1971). La notion de ‘collectif’ est à distinguer de la notion de ‘pluriel’ (Gillon, 1992) et permet d’expliquer le lien entre les deux propriétés morphosyntaxiques présentées. Cette hypothèse générale s’appuie sur la sélection d’un ensemble d’outils d’analyse. Un premier outil vise à rendre compte, du point de vue formel, des réseaux syntactico-sémantiques, par une représentation abstraite de la syntaxe verbale, conçue comme une ‘syntaxe de position’ et où sont délimitées, autour du noyau verbal, deux zones syntaxiques (zone SUJET et zone OBJET) constituées de points d’ancrage du trait de complexité. En tenant compte de la spécificité du ‘collectif’ par rapport à la ‘pluralité’, le recours au concept d’opérateurs de complexité, entendus comme des opérateurs du trait [+discret] (Doetjes, 1999), permet de mieux définir la notion du ‘collectif’ appliquée au domaine verbal. Les différents opérateurs – affixes dérivationnels, constructions prépositionnelles, constructions en SE - se situent à différents niveaux de structuration. L’analyse par ‘opérateurs de complexité’ ([+discret]) présuppose également la prise en compte de la fonction quantitative. Dans cette perspective, ces opérateurs induisent différents degrés de l‘individuation’ des constituants du ‘collectif’ dénoté par la sémantique des verbes à trait de complexité. Les échelles de gradation de [+discret] rendent compte de cette propriété. Les valeurs de ‘plus d’un’ et ‘en un’ dénotées par les expressions verbales à trait de complexité sont interprétées comme faisant partie d’une structure conceptuelle de type ‘tout-intégré’ d’après l’approche lexicale et multidimensionnelle de la sémantique conceptuelle des relations parties/tout de Moltmann (1997).

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The objective of this work was to evaluate the effect of environmental variables on dairy buffaloes physiology in two different places after milking, shaded plus artificial ventilation and another one non-shaded, in Ribeira Valley, São Paulo State, Brazil. Data on the respiratory rate (RR) and the surface temperature (ST) at udder, neckmiddle, forehead, back middle and rump were collected in 12 dairy buffaloes at autumn. In the same way, it were recorded the black globe temperature in the sun (GTS) and in the shade (GTNS), air temperature and wind speed at padronized height of 1.60 meters. All data were collected at 10:30am and 1:30pm. The results showed statistical difference among black globe temperature, wind speed, RR and ST (P<0.01) in two treatments.The results showed the necessity of protection against the solar radiation in the buffaloes, even in periods of warm climates.

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European corn borer (ECB) [Ostrinia nubilalis (Hubner)] (Lepidoptera: Crambidae) is known to infest Irish potato (Solanum tuberosum L.) but only causes economic damage during the first generation in East Coast potato producing areas. However, in Nebraska, second generation ECB infest potato plants during the bulking period and may reduce yield and/or potato quality. Experiments were conducted in 2001, 2002, and 2003 to examine physiological and yield effects of second generation ECB injury to potato in Nebraska. Pike, Atlantic, and three Frito Lay proprietary varieties (FL1867, FL1879, and FL1833) were used. Experimental plots were infested with four ECB egg masses per plant to simulate ECB infestation by second-generation larvae; controls received no egg masses. Photosynthetic rates, tuber weights, tuber size grades, solids, and fry quality were measured. Potato plants with ECB infestation had significantly reduced photosynthetic rates on ECB-infested stems and on uninfested stems on the same plant when larvae were in the fifth instar. When insects were in the fourth instar, photosynthetic rates were reduced only on ECB-infested stems. In 2001, ECB infestation reduced the average mass of large tubers and increased the amount of small tubers in FL1867 and FL1879. In 2002, significant yield reductions were not observed. Across both years, ECB-infested plots produced fewer large (65- to 100-mm diam.) tubers than control plots. Other tuber properties and chip qualities were unaffected. This study indicates that second generation ECB infestation of approximately 30% infested plants results in economic loss for some chipping varieties and affects tuber bulking. In contrast to east coast growers, Midwest potato farmers must be concerned with second generation ECB.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)