824 resultados para Glycogen content


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The amount of nitrogen required to complete an insect's life cycle may vary greatly among species that have evolved distinct life history traits. Myrmecophilous caterpillars in the Lycaenidae family produce nitrogen-rich exudates from their dorsal glands to attract ants for protection, and this phenomenon has been postulated to shape the caterpillar's host-plant choice. Accordingly, it was postulated that evolution towards myrmecophily in Lycaenidae is correlated with the utilization of nitrogen-rich host plants. Although our results were consistent with the evolutionary shifts towards high-nutrient host plants serving as exaptation for the evolution of myrmecophily in lycaenids, the selection of nitrogen-rich host plants was not confined to lycaenids. Butterfly species in the nonmyrmecophilous family Pieridae also preferred nitrogen-rich host plants. Thus, we conclude that nitrogen is an overall important component in the caterpillar diet, independent of the level of myrmecophily, as nitrogen can enhance the overall insect fitness and survival. However, when nitrogen can be obtained through alternative means, as in socially parasitic lycaenid species feeding on ant brood, the selective pressure for maintaining the use of nutrient-rich host plants is relaxed, enabling the colonization of nitrogen-poor host plants.

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Aquest estudi pretén investigar els intercanvis verbals mestre/a – aprenent(s) en dos contextos d'instrucció diferents: classes amb un enfocament AICLE (Aprenentatge Integrat de Continguts Curriculars i Llengua Estrangera) on s’aprenen continguts no lingüístics a través de l’anglès, per una banda, i classes 'tradicionals' d'anglès com a llengua estrangera, on l’anglès és alhora objecte d’estudi i vehicle de comunicació, per una altra banda. Més concretament, les preguntes que formula el/la mestre/a, la producció oral dels aprenents i el 'feedback' del/de la mestre/a en els episodis d’atenció a la forma s’han estudiat a la llum de les principals teories provinents del camp de l’Adquisició de Segones Llengües (SLA) per tal de demostrar el seu paper en l’aprenentatge de l’anglès. El corpus de dades prové de l’enregistrament de 7 sessions AICLE i d'11 sessions EFL enregistrades en format àudio i vídeo en dos centres públics d’Educació Primària (EP) de Catalunya. A cadascuna de les escoles, el/la mateix/a mestre/a és l’encarregat/da dels dos tipus d’instrucció amb el mateix grup d’aprenents (10-11 anys d’edat), fet que permet eliminar variables individuals com l'aptitud dels aprenents o l'estil del/de la mestre/a.Els resultats mostren un cert nombre de similituds discursives entre AICLE i EFL donat que ambdós enfocaments tenen lloc en el context-classe amb unes característiques ben definides. Tal com apunta la recerca realitzada en aquest camp, la instrucció AICLE reuneix un seguit de condicions idònies per un major desenvolupament dels nivells de llengua anglesa més enllà de les classes ‘tradicionals’ d’anglès. Malgrat això, aquest estudi sembla indicar que el potencial d'AICLE pel que fa a facilitar una exposició rica a l’anglès i una producció oral significativa no s’explota degudament. En aquest sentit, els resultats d’aquest estudi poden contribuir a la formació dels futurs professors d'AICLE si es busca l’assoliment d’una complementarietat d’ambdós contextos amb l’objectiu últim de millorar els nivells de domini de la llengua anglesa.

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This research investigates differences in the stereotype content of immigrant groups between linguistic regions. We expected that immigrant groups who speak the local language of a specific linguistic region would be perceived as more competitive within this region than in another linguistic region. Further, we expected these differences would underlie regional differences in stereotype content, albeit only for the warmth dimension. Predictions were tested in the two largest linguistic regions of Switzerland. As expected, in the German-speaking region, locals perceived German immigrants as more competitive and thus as less warm, whereas in the French-speaking region, locals perceived French immigrants as more competitive and, consequently, as less warm. So, paradoxically, immigrants with strong integration potential are particularly disliked because they are regarded as direct competitors.

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Los sistemas de radio cognitivos son una solución a la deficiente distribución del espectro inalámbrico de frecuencias. Usando acceso dinámico al medio, los usuarios secundarios pueden comunicarse en canales de frecuencia disponibles, mientras los usuarios asignados no están usando dichos canales. Un buen sistema de mensajería de control es necesario para que los usuarios secundarios no interfieran con los usuarios primarios en las redes de radio cognitivas. Para redes en donde los usuarios son heterogéneos en frecuencia, es decir, no poseen los mismos canales de frecuencia para comunicarse, el grupo de canales utilizado para transmitir información de control debe elegirse cuidadosamente. Por esta razón, en esta tesis se estudian las ideas básicas de los esquemas de mensajería de control usados en las redes de radio cognitivas y se presenta un esquema adecuado para un control adecuado para usuarios heterogéneos en canales de frecuencia. Para ello, primero se presenta una nueva taxonomía para clasificar las estrategias de mensajería de control, identificando las principales características que debe cumplir un esquema de control para sistemas heterogéneos en frecuencia. Luego, se revisan diversas técnicas matemáticas para escoger el mínimo número de canales por los cuales se transmite la información de control. Después, se introduce un modelo de un esquema de mensajería de control que use el mínimo número de canales y que utilice las características de los sistemas heterogéneos en frecuencia. Por último, se comparan diversos esquemas de mensajería de control en términos de la eficiencia de transmisión.

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Time-lapse geophysical data acquired during transient hydrological experiments are being increasingly employed to estimate subsurface hydraulic properties at the field scale. In particular, crosshole ground-penetrating radar (GPR) data, collected while water infiltrates into the subsurface either by natural or artificial means, have been demonstrated in a number of studies to contain valuable information concerning the hydraulic properties of the unsaturated zone. Previous work in this domain has considered a variety of infiltration conditions and different amounts of time-lapse GPR data in the estimation procedure. However, the particular benefits and drawbacks of these different strategies as well as the impact of a variety of key and common assumptions remain unclear. Using a Bayesian Markov-chain-Monte-Carlo stochastic inversion methodology, we examine in this paper the information content of time-lapse zero-offset-profile (ZOP) GPR traveltime data, collected under three different infiltration conditions, for the estimation of van Genuchten-Mualem (VGM) parameters in a layered subsurface medium. Specifically, we systematically analyze synthetic and field GPR data acquired under natural loading and two rates of forced infiltration, and we consider the value of incorporating different amounts of time-lapse measurements into the estimation procedure. Our results confirm that, for all infiltration scenarios considered, the ZOP GPR traveltime data contain important information about subsurface hydraulic properties as a function of depth, with forced infiltration offering the greatest potential for VGM parameter refinement because of the higher stressing of the hydrological system. Considering greater amounts of time-lapse data in the inversion procedure is also found to help refine VGM parameter estimates. Quite importantly, however, inconsistencies observed in the field results point to the strong possibility that posterior uncertainties are being influenced by model structural errors, which in turn underlines the fundamental importance of a systematic analysis of such errors in future related studies.

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Report to Margaret Thompson, Chief Clerk, about Recycled Content Plastic Bag and Soy Inks.

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A novel approach to the study of hepatic glycogen kinetics and fractional gluconeogenesis in vivo is described. Ten healthy female subjects were fed an iso-caloric diet containing 55% carbohydrate energy with a 13C abundance of 1.083 atom percent for a 3-day baseline period; then, a diet of similar composition, but providing carbohydrate with a 13C abundance of 1.093 atom percent was started and continued for 5 days. Resting respiratory gas exchanges, urinary nitrogen excretion, breath 13CO2 and plasma 13C glucose were measured every morning in the fasting state. The enrichment in 13C of hepatic glycogen was calculated from these measured data. 13C glycogen enrichment increased after switching to a 13C enriched carbohydrate diet, and was identical to the 13C enrichment of dietary carbohydrates after 3 days. The time required to renew 50% of hepatic glycogen, as determined from the kinetics of 13C glycogen enrichment, was 18.9 +/- 3.6 h. Fractional gluconeogenesis, as determined from the difference between the enrichments of glucose oxidized originating from hepatic glycogen and plasma glucose 13C was 50.8 +/- 5.3%. This non-invasive method will allow the study of hepatic glycogen metabolism in insulin-resistant patients.

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The investigation of gender differences in emotion has attracted much attention given the potential ramifications on our understanding of sexual differences in disorders involving emotion dysregulation. Yet, research on content-specific gender differences across adulthood in emotional responding is lacking. The aims of the present study were twofold. First, we sought to investigate to what extent gender differences in the self-reported emotional experience are content specific. Second, we sought to determine whether gender differences are stable across the adult lifespan. We assessed valence and arousal ratings of 14 picture series, each of a different content, in 94 men and 118 women aged 20 to 81. Compared to women, men reacted more positively to erotic images, whereas women rated low-arousing pleasant family scenes and landscapes as particularly positive. Women displayed a disposition to respond with greater defensive activation (i.e., more negative valence and higher arousal), in particular to the most arousing unpleasant contents. Importantly, significant interactions between gender and age were not found for any single content. This study makes a novel contribution by showing that gender differences in the affective experiences in response to different contents persist across the adult lifespan. These findings support the "stability hypothesis" of gender differences across age.

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In spite of the fact that the Ars predicandi populo is attributed to Eiximenis in only one of the three extant manuscripts, there is no doubt that it is one of his works.First of all, the internal references to this treatise in the pages of Terç and Dotzè del Crestià are an irrefutable testimony and, secondly, the presence of an autographvolume of sermons which begins with the Ars in the inventory of the Eiximenis library made shortly after his death. The writing of the Ars and the collection of sermons which introduces it must be dated prior to the beginning of the Crestià encyclopedia (1379) because of the complexity that entailed the writing of a collection of three perhaps four volumes of sermons. Due to a series of formal and codicological reasons it must be concluded that the chapter entitled De consiliis circa predicacionem cannot be attributed to Eiximenis and thus be excluded from the Ars

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Neurodegenerative and psychiatric disorders including Alzheimer's, Parkinson's or Huntington's diseases and schizophrenia have been associated with a deficit in glutathione (GSH). In particular, a polymorphism in the gene of glutamate cysteine ligase modulatory subunit (GCLM) is associated with schizophrenia. GSH is the most important intracellular antioxidant and is necessary for the removal of reactive by-products generated by the utilization of glucose for energy supply. Furthermore, glucose metabolism through the pentose phosphate pathway is a major source of NADPH, the cofactor necessary for the regeneration of reduced glutathione. This study aims at investigating glucose metabolism in cultured astrocytes from GCLM knockout mice, which show decreased GSH levels. No difference in the basal metabolism of glucose was observed between wild-type and knockout cells. In contrast, glycogen levels were lower and its turnover was higher in knockout astrocytes. These changes were accompanied by a decrease in the expression of the genes involved in its synthesis and degradation, including the protein targeting to glycogen. During an oxidative challenge induced by tert-Butylhydroperoxide, wild-type cells increased their glycogen mobilization and glucose uptake. However, knockout astrocytes were unable to mobilize glycogen following the same stress and they could increase their glucose utilization only following a major oxidative insult. Altogether, these results show that glucose metabolism and glycogen utilization are dysregulated in astrocytes showing a chronic deficit in GSH, suggesting that alterations of a fundamental aspect of brain energy metabolism is caused by GSH deficit and may therefore be relevant to metabolic dysfunctions observed in schizophrenia.

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Background: The COSMIN checklist (COnsensus-based Standards for the selection of health status Measurement INstruments) was developed in an international Delphi study to evaluate the methodological quality of studies on measurement properties of health-related patient reported outcomes (HR-PROs). In this paper, we explain our choices for the design requirements and preferred statistical methods for which no evidence is available in the literature or on which the Delphi panel members had substantial discussion. Methods: The issues described in this paper are a reflection of the Delphi process in which 43 panel members participated. Results: The topics discussed are internal consistency (relevance for reflective and formative models, and distinction with unidimensionality), content validity (judging relevance and comprehensiveness), hypotheses testing as an aspect of construct validity (specificity of hypotheses), criterion validity (relevance for PROs), and responsiveness (concept and relation to validity, and (in) appropriate measures).Conclusions: We expect that this paper will contribute to a better understanding of the rationale behind the items, thereby enhancing the acceptance and use of the COSMIN checklist.

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Neuron-astrocyte reciprocal communication at synapses has emerged as a novel signalling pathway in brain function. Astrocytes sense the level of synaptic activity and, in turn, influence its efficacy through the regulated release of ''glio- transmitters'' such as glutamate, ATP or D-serine. A calcium- dependent exocytosis is proposed to drive the release of gliotransmitters but its existence is still debated. To shed light onto the mechanisms controlling the storage and the release of gliotransmitters and namely D-serine, we have developed a new method for the immunoisolation of synaptobrevin 2-positive vesicles from rat cortical astrocytes in culture. The purified organelles are clear round shape vesicles of excellent purity as judged by electron microscopy. Immunoblotting analysis revealed that isolated vesicles contain most of the major proteins already described for neuron-derived vesicles. In addition, we have analyzed the content for various amino acids of these vesicles by means of chiral capillary electro- phoresis coupled to laser-induced fluorescence detection and liquid chromatography coupled to mass spectrometry. Post- embedding immunogold labelling of the rat neocortex and hippocampus further revealed the expression of D-serine and glutamate in astrocyte processes contacting excitatory sy- napses. Our results provide significant support for the existence of secretory glial vesicles storing chemical substances like D- serine and glutamate and thus point to the co-release of amino acids by exocytosis in astrocytes.

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