1,546 research outputs found
PocketGraph : graph representation of binding site volumes
The representation of small molecules as molecular graphs is a common technique in various fields of cheminformatics. This approach employs abstract descriptions of topology and properties for rapid analyses and comparison. Receptor-based methods in contrast mostly depend on more complex representations impeding simplified analysis and limiting the possibilities of property assignment. In this study we demonstrate that ligand-based methods can be applied to receptor-derived binding site analysis. We introduce the new method PocketGraph that translates representations of binding site volumes into linear graphs and enables the application of graph-based methods to the world of protein pockets. The method uses the PocketPicker algorithm for characterization of binding site volumes and employs a Growing Neural Gas procedure to derive graph representations of pocket topologies. Self-organizing map (SOM) projections revealed a limited number of pocket topologies. We argue that there is only a small set of pocket shapes realized in the known ligand-receptor complexes
Feeding regimes affected the circadian rhythms of pancreatic digestive enzymes and somatic growth in flathead grey mullet (Mugil cephalus) fry
The effect of different feeding regimes on the circadian rhythms of pancreatic digestive enzyme activities was evaluated in Mugil cephalus fry weighting 0.34 ± 0.01 g. Feeding regimes (feeding ration = 3% stocked biomass) differed on the number of meals offered per day: one, two and ten meals per day (R1, R2 and R3, respectively). The number of meals per day affected somatic growth; in particular, fry from the R3 group (0.80 ± 0.01 g) grew better than their congeners from R2 (0.70 ± 0.01 g) and R1 (0.63 ± 0.01 g) groups (P < 0.05). Feeding behaviour was modulated by the feeding regime, being the maximal gut fullness values found just after meal distribution in R1 and R2 groups, whereas this trend was not observed when feed was offered continuously during light hours (R3). Fry from R1 and R2 groups showed hyperphagia as they tended to store in their gut as much as possible feed particles to be later digested due to the limited daily meals. This strategy negatively affected feed digestion due to inappropriate enzyme to substrate ratio, changes in digestive enzyme activities and chyme transit times, which ultimately impaired growth performance. Enzyme activities were modulated by the number of meals, the more frequent the meals offered, the lower enzyme activities, supporting the hypothesis that digestive function is adapted to obtain a maximum benefit of the ingested nutrients. Present results showed that feeding grey mullet fry continuously during day light hours optimized feed digestion and promoted fry growth.info:eu-repo/semantics/acceptedVersio
Bases para el estudio de la adquisición del sistema verbal del español como lengua extranjera
Los trabajos sobre la adquisición del sistema verbal del español despiertan dudas referidas al número de aprendices que configuran la base del estudio, a la valoración del grado de conocimiento de nuestra lengua por parte de los estudiantes que configuran el análisis, y a la muestra de lengua y la clase de prueba empleadas para evaluar el uso. Hemos de dotarnos de un procedimiento cientÃfico sustentado en la existencia de una base conceptual sólida y en la puesta en marcha de un análisis coherente y consistente de los datos recabados. La base cientÃfica para la construcción de muestras de trabajo fiables se encuentra en la estadÃstica inferencial: debemos concretar nuestros estudios en universos de trabajo accesibles y aprehensibles. Para ello buscaremos los aprendices de español en áreas donde estén adecuadamente cuantificados. El espacio de trabajo ideal serán las pruebas de evaluación de lenguas existentes en la actualidad basadas en escalas de niveles que cuenten con un alto grado de fiabilidad.Research into Spanish verb acquisition raises considerable doubts with regard to the number of learners forming the basis of the study, the knowledge of Spanish those learners have, and the type of language and tests applied to assess their use of the language. It is essential that we adopt a scientific method based on inferential statistics, which will provide us with a solid conceptual basis, and coherent and consistent data analysis. To put this method into practice, we must focus our research on accessible and attainable working universes, and, therefore, work with learners of Spanish in areas where they can be properly quantified. Language assessment tests based on level scales and with a high degree of reliability are the ideal workspace
Response of potential cucurbit rootstocks against Meloidogyne spp
the Cucurbita hybrids, usually used as cucurbit rootstocks, are
susceptible to Meloidogyne.
Its cultivation increases the nematode population densities
at similar levels than ungrafted cucumber or melon crops, and
higher 'Ievels than watermelon.Postprint (published version
La conexión discursiva en textos escritos descriptivos
En este trabajo se estudia, a partir de un corpus de 383 textos, la función de los conectores discursivos en la construcción de escritos redactados sobre la base de una secuencia dominante de naturaleza descriptiva. En primer lugar, se valora cómo afecta al uso de los enlaces la naturaleza conceptual de la descripción según se fije esta en seres humanos o en espacios fÃsicos tales como viviendas. A continuación, se centra en la función de los enlaces temporales y los ordenadores discursivos en la confi guración de perspectivas dinámicas de descripción. En tercer término, se evalúa el uso de los relacionantes locativos como enlaces textuales que establecen un tipo de relación entre un objeto base y un objeto figura ubicados en unidades textuales distintas. Por último, se clasifican los conectores espaciales identificados sobre siete ejes básicos de organización y se analiza la coaparición de enlaces correspondientes a ejes distintos.This study analyzes a corpus of 383 texts in order to study the function of discourse connectors in the creation of written texts with a fundamentally descriptive structure. Firstly, this study assesses the extent to which the conceptual nature of description affects the use of discourse connectors depending on whether it deals with humans or with physical spaces such as houses. Next, the study focuses on the function of discourse and temporal connectors in the configuration of dynamic description perspectives. The third part of the study analyzes the use of locative connectors as linking elements which establish a relationship between a concrete object and a figurative one which are located in different text units. Finally, the spatial connectors found during the study are classified into seven basic organizational categories and the instances of connectors which appear in more than one category are analyzed
Editorial: Animal welfare, Volume I: Animal welfare in aquaculture - Physiological basis and recent findings
Since animal welfare is a multidisciplinary scientific discipline, the papers published in this special issue are based on diverse subjects, such as feeding and nutrition, behavior, immunology, reproduction, pathology, endocrinology, and neuroendocrinology. The studies targeting fish species have been the most frequent, being salmonids the main group. Nevertheless, only one out of the thirteen published articles deals with an invertebrate species, the lobster (Homarus americanus), which highlights the recent interest for crustaceans’ welfare. The results derived from these works state objectively the importance of animal welfare in both physiological and behavioral traits and responses, as well as in zootechnical parameters of interest for farmers.info:eu-repo/semantics/publishedVersio
Influence of glyoxal in the physical characterization of PVA nanofibres
[EN] The influence of solution composition is directly related to the properties of polyvinyl alcohol (PVA) nanofibers. Electrospinning is a viable technique to develop PVA nanofibers. The presence of a crosslinking agent such as glyoxal can produce variations not only in anti-water solubility effect, but also in the morphology of the electrodeposited fibers. The objective of this study was to characterize the influence of glyoxal on PVA nanofibers. Thus, we studied fiber dimensions, the weight of deposited fibers, and fiber crystallinity. The relation between those properties and the properties of the nanofiber web (color, opacity, and roughness) were studied. In this study we changed glyoxal concentration. Scanning electron microscopy, differential scanning calorimetry, and atomic force microscopy showed changes in the fiber properties. We could observe how the diameter fiber increased, the collector surface was widely covered, and the fiber crystallinity decreased. Regarding the properties of the web, the roughness decreased and the color turned whiter.The authors wish to acknowledge the financial support of the MINISTERIO DE CIENCIA E INNOVACION. Ref: CIT-020000-2008-016 for financial support. Also, the microscopy services at UPV are gratefully acknowledged for their assistance in using AFM techniques, and Octavio Fenollar at UPV is gratefully acknowledged for his assistance in using calorimetric techniques.Blanes, M.; Gisbert, MJ.; Marco, B.; Bonet Aracil, MA.; Gisbert Paya, J.; Balart Gimeno, RA. (2010). Influence of glyoxal in the physical characterization of PVA nanofibres. Textile Research Journal. 80(14):1465-1472. doi:10.1177/0040517509357654S14651472801
- …