852 resultados para Arthropods. Lizards. Niche breadth. Ontogeny. Behavioral plasticity. Seasonality


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We study four measures of problem instance behavior that might account for the observed differences in interior-point method (IPM) iterations when these methods are used to solve semidefinite programming (SDP) problem instances: (i) an aggregate geometry measure related to the primal and dual feasible regions (aspect ratios) and norms of the optimal solutions, (ii) the (Renegar-) condition measure C(d) of the data instance, (iii) a measure of the near-absence of strict complementarity of the optimal solution, and (iv) the level of degeneracy of the optimal solution. We compute these measures for the SDPLIB suite problem instances and measure the correlation between these measures and IPM iteration counts (solved using the software SDPT3) when the measures have finite values. Our conclusions are roughly as follows: the aggregate geometry measure is highly correlated with IPM iterations (CORR = 0.896), and is a very good predictor of IPM iterations, particularly for problem instances with solutions of small norm and aspect ratio. The condition measure C(d) is also correlated with IPM iterations, but less so than the aggregate geometry measure (CORR = 0.630). The near-absence of strict complementarity is weakly correlated with IPM iterations (CORR = 0.423). The level of degeneracy of the optimal solution is essentially uncorrelated with IPM iterations.

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This article gives an overview of presuppositions and explanations posed by behaviorist psychology (particularly its radical branch), cognitive–nativist sciences (i.e. psycholinguistics and a branch of cognitive psychology) and other disciplines regarding important psychological events such as anxiety, stress, fear, mood states and language. In relation to the discussion of environment versus genetics, contributions from behavioral neurobiology and neuropsychology are added, showing evidence of traits that can be multigenerationally inherited in a non-genetic way, which have an impact thought the life of organisms and on their way of interacting with the environment; ways in which behavior can be altered by recently unsuspected environmental agents or events, and the overlooked role of prenatal experiences in the explanation of behavior. The evidence calls into question presuppositions made by the academic disciplines listed above, and suggests alternative behavior reinterpretations and explanations

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Impulsivity has been linked to three main factors: performing without direct involvement of the frontal lobe functions, an increase in the speed of response, and the acquisition of immediate gratification. This behavioral inhibition deficit involves a variety of behaviors including aspects of hyperexcitability, behavioral disinhibition and higher order decision making. Although by tradition, the definition of this executive function has been conceptualized from a psychopathological view, currently, the wide variety of neuropsychological, developmental and animal models assessment techniques encourage us to establish dialogues that integrate the knowledge of these theoretical perspectives for the interpretation and understanding of impulsivity.

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Behavioral neurosciences have evolved from other disciplines such as psychology, psychiatry and neurology, becoming a prominent area within general neuroscience. In mainstream psychology, neurosciences currently have an important role. In this paper we documented articles published in four Latin-American psychology journals and we classified these papers as empirical or theoretical. We analyzed the main topics covered in the behavioral neurosciences. Most of reported research used humans and rats as study subjects, although other species have also been used as models. Data suggest behavioral neurosciences currently play a growing and prominent role in Latin American psychology.

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Objective: To determine the change of behavior in physical activity and the characteristics associated with the use and benefits of Local Physical Activity Center (CLAF) in the population of the town of Santa Fe de Bogota. Materials and methods: We conducted a longitudinal study before and after, which was assessed at admission and 3 months in the intervention program CLAF physical activity, behavior change compared to the physical activity of users. Inclusion criteria: were being active user of CLAF, aged between 15 and 65 years and voluntarily express their participation in the study. Exclusion criteria: Fill incomplete measurement instruments used. The sampling frame of CLAF users, we selected n=55 subjects. To gather information, a questionnaire, which contained the behavioral stages of change, also conducted a survey which determined semistructured features about the benefits and use of CLAF. Results: The total study participants was n = 55, mean age was 40.4 ± 15.3 years, with a minimum 15 and maximum of 64 years, 83.6% were women. 78.2% do not know the purpose of the Local Centre for Physical Activity. The outreach strategy that most came to the group was 58.2 with a verbal type. The time for links to CLAF more frequently in the group evaluated was 1 to 6 months 36.4. The motivation to regularly attend the CLAF in the majority was to improve the physical and / or a 74.5% mental. 89.1% would be willing to recommend to others the use of CLAF. A 81.8% of the population physical activity performed by more than 150 min / wk at moderate intensity; Post CLAF intervention in the subjects showed positive changes in the level of physical activity (p<0.001, Test de Wilcoxon) and behavioral state (p<0.001, Test de Wilcoxon).

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In most studies on civil wars, determinants of conflict have been hitherto explored assuming that actors involved were either unitary or stable. However, if this intra-group homogeneity assumption does not hold, empirical econometric estimates may be biased. We use Fixed Effects Finite Mixture Model (FE-FMM) approach to address this issue that provides a representation of heterogeneity when data originate from different latent classes and the affiliation is unknown. It allows to identify sub-populations within a population as well as the determinants of their behaviors. By combining various data sources for the period 2000-2005, we apply this methodology to the Colombian conflict. Our results highlight a behavioral heterogeneity in guerrilla’s armed groups and their distinct economic correlates. By contrast paramilitaries behave as a rather homogenous group.

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INTRODUCCIÓN: El 80% de los niños y adolescentes con trastornos del espectro autista (TEA) presenta algún trastorno del sueño, en cuya génesis al parecer intervienen alteraciones en la regulación de la melatonina. El objetivo de este metaanálisis fue determinar la eficacia y seguridad de la melatonina para el manejo de ciertos trastornos del sueño en niños con TEA. MÉTODOS: Tres revisores extrajeron los datos relevantes de los ensayos clínicos aleatorizados doble ciego de alta calidad publicados en bases de datos primarias, de ensayos clínicos, de revisiones sistemáticas y de literatura gris; además se realizó búsqueda en bola de nieve. Se analizaron los datos con RevMan 5.3. Se realizó un análisis del inverso de la varianza por un modelo de efectos aleatorios para las diferencias de medias de los desenlaces propuestos: duración del tiempo total, latencia de sueño y número de despertares nocturnos. Se evaluó la heterogeneidad interestudios con el parámetro I2 RESULTADOS: La búsqueda inicial arrojó 355 resultados, de los cuales tres cumplieron los criterios de selección. La melatonina resultó ser un medicamento seguro y eficaz para aumentar la duración total del sueño y disminuir la latencia de sueño en niños y adolescentes con TEA; hasta el momento la evidencia sobre el número de despertares nocturnos no es estadísticamente significativa. DISCUSIÓN: A la luz de la evidencia disponible, la melatonina es una elección segura y eficaz para el manejo de ciertos problemas del sueño en niños y adolescentes con TEA. Es necesario realizar estudios con mayores tamaños muestrales y comparados con otros medicamentos disponibles en el mercado.

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Centrándose en las principales familias de insectos, esta guía de insectos, arañas y otros artrópodos terrestres del todo el mundo, se ocupa de la diversidad de esta clase. Se examinan los veintinueve órdenes de insectos, así como una selección representativa de las arañas y otros artrópodos terrestres de todo el mundo, incluyendo características físicas, ciclo de vida, hábitat y estadios larvales. Tiene índice y fotografías de más de quinientas cincuenta familias de insectos.

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Este manual reúne múltiples perspectivas contemporáneas sobre la eficacia de la intervención en el área de la educación del autismo y de apoyo a la conducta. Presenta una valoración crítica de las normas de la práctica actual, haciendo hincapié en los procedimientos de apoyo empírico y en las aplicaciones de la investigación a la práctica. Es un marco esencial para evaluar los procedimientos educativos y de tratamiento, seleccionando aquellos que son más eficaces, y evaluando los resultados.

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Resumen tomado de la publicaci??n

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Zooplankton community structure (composition, diversity, dynamics and trophic relationships) of Mediterranian marshes, has been analysed by means of a size based approach. In temporary basins the shape of the biomass-size spectra is related to the hydrological cycle. Linear shape spectra are more frequent in flooding situations when nutrient input causes population growth of small-sized organisms, more than compensating for the effect of competitive interactions. During confinement conditions the scarcity of food would decrease zooplankton growth and increase intra- and interspecific interactions between zooplankton organisms which favour the greatest sizes thus leading to the appearance of curved shape spectra. Temporary and permanent basins have similar taxonomic composition but the latter have higher species diversity, a more simplified temporal pattern and a size distribution dominated mainly by smaller sizes. In permanents basins zooplankton growth is not only conditioned by the availability of resources but by the variable predation of planktivorous fish, so that the temporal variability of the spectra may also be a result of temporal differences in fish predation. Size diversity seems to be a better indicator of the degree of this community structure than species diversity. The tendency of size diversity to increase during succession makes it useful to discriminate between different succession stages, fact that is not achieved by analysing only species diversity since it is low both under large and frequent or small and rare disturbances. Amino acid composition differences found among stages of copepod species indicate a gradual change in diet during the life cycle of these copepods, which provide evidence of food niche partitioning during ontogeny, whereas Daphnia species show a relatively constant amino acid composition. There is a relationship between the degree of trophic niche overlap among stages of the different species and nutrient concentration. Copepods, which have low trophic niche overlap among stages are dominant in food-limited environments, probably because trophic niche partitioning during development allow them to reduce intraspecific competition between adults, juveniles and nauplii. Daphnia species are only dominant in water bodies or periods with high productivity, probably due to the high trophic niche overlap between juveniles and adults. These findings suggest that, in addition to the effect of interspecific competition, predation and abiotic factors, the intraspecific competition might play also an important role in structuring zooplankton assemblages.

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La formiga argentina (Linepithema humile) es troba entre les espècies més invasores: originària d'Amèrica del Sud, actualment ha envaït nombroses àrees arreu del món. Aquesta tesi doctoral intenta fer una primera anàlisi integrada i multiescalar de la distribució de la formiga argentina mitjançant l'ús de models de nínxol ecològic. D'acord amb els resultats obtinguts, es preveu que la formiga argentina assoleixi una distribució més àmplia que l'actual. Les prediccions obtingudes a partir dels models concorden amb la distribució actualment coneguda i, a més, indiquen àrees a prop de la costa i dels rius principals com a altament favorables per a l'espècie. Aquests resultats corroboren la idea que la formiga argentina no es troba actualment en equilibri amb el medi. D'altra banda, amb el canvi climàtic, s'espera que la distribució de la formiga argentina s'estengui cap a latituds més elevades en ambdós hemisferis, i sofreixi una retracció en els tròpics a escales globals.