619 research outputs found
Nestling diet and fledgling production of eurasian kestrels (Falco tinnunculus) in eastern Spain.
We studied 81 Eurasian kestrel (Falco tinnunculus) nests in the Alto Palancia region (Castel16n, eastern Spain) from 1982-87. Fledgling production was recorded in routine visits to the nests, and the diet was determined by pellet analysis. The mean date of laying was 8 May (N -- 24, SD -- 11.5), similar to that of populations breeding further north in Europe. On average, each successful pair produced four fledglings per year (N = 47, SD = 0.7, range = 2-5), and no significant differences in fledging success were found among years. Grasshoppers formed the bulk of the diet during the nestling period. Mammals and birds were scarcely represented. The number of fledglings per successful pair was similar to or higher than that reported from Finland, Germany, and England where voles are the main prey brought to the nestlings. We suggest that a relative abundance of insects, and reduced energy requirements for thermoregulation in Mediterranean areas allow kestrels to successfully feed their young mainly on insects, without reducing fledgling production in relation to populations where voles form the bulk of the nestling diet. Se estudiaron 81 nidos de cernícalo vulgar (Falco tinnunculus) en la comarca del Alto Palancia (Castel16n, Este de España) entre 1982-87. La producci6n de pollos se estudió mediante visitas periódicas a los nidos, y la dieta analizando las egagrópilas recolectadas durante el periodo de permanencia de los pollos en el nido. La fecha media de inicio de la puesta fue el 8 de Mayo (N -- 24, SD -- 11.5), similar a las observadas en otros países de Europa. Cada pareja con éxito produce una media de cuatro pollos por año (N -- 47, SD = 0.7, rango -- 2-5), no habiendo diferencias significativas entre años. Los saltamontes forman la base de la dieta durante el periodo estudiado, estando los mamíferos y las aves escasamente representados. La producción de pollos por pareja con éxito es similar o mayor a las obtenidas en Finlandia, Alemania e Inglaterra, donde los topillos forman la base de la dieta de los pollos. Se sugiere que una mayor disponibilidad de insectos, y una reducción de los requerimientos energéticos de los pollos en las áreas mediterráneas, permiten a los cernícalos alimentar a los pollos con una dieta basada en insectos sin reducir su productividad con respecto a poblaciones donde los mamíferos son la base de la dieta
Production and Evaluation of Activated Carbon from Sludge Generated in a Sewage Treatment Plant
Indexación: ScieloEn este trabajo se evaluó el carbón activado producido a partir de lodo generado en una planta de tratamiento de aguas servidas. El lodo utilizado proviene de un lodo activado tipo aireación extendida y la transformación fue realizada mediante un proceso de activación química con cloruro de zinc y pirólisis. La pirólisis se realizó a diferentes temperaturas (550, 600, 650°C) y tiempos (30, 45 y 60 minutos). El rendimiento en carbón obtenido fluctuó entre el 42 y 66%, registrándose el mayor rendimiento a la temperatura de 550°C. La capacidad de adsorción, para el carbón activado obtenido, evaluada mediante la constante de adsorción lineal, para el colorante cristal violeta, fluctuó entre los 0,05 y 0,132 L/g. De acuerdo a esto, el mejor carbón se obtuvo cuando la temperatura de pirólisis fue de 650 °C. No resulta estadísticamente significativo el efecto del tiempo de pirólisis, en la constante de adsorción lineal.
Abstract
This study evaluated the activated carbon produced from the sludge generated in a sewage treatment plant. The sewage sludge used came from an extended aeration plant, and the transformation was carried out by means of a process of chemical activation with zinc chloride and pyrolysis. Pyrolysis was done at different temperatures (550, 600, 650°C) and times (30, 45 and 60 minutes). The yield of the carbon obtained fluctuated between 42% and 66%, with the highest yield recorded at 550°C. The adsorption capacity for the activated charcoal obtained, evaluated by means of the constant of linear adsorption for the dye crystal violet, fluctuated between 0,05 and 0,132 L/g. According to this, the best charcoal was obtained when pyrolysis temperature was 650°C. The effect of the pyrolysis time on the constant of linear adsorption was not statistically significant
Status of carnivores in Biscay (N lberian peninsula)
The first study on the carnivore community of Biscay was published in 1985. The present study, made twelve years later, was carried out to assess the present situation of these mammals. In this work, data collected from 1990 to 1996 by trapping, sighting, and surveying road and other kills, as well as faeces and tracks are reported. Records of 12 species were obtained, of which American mink Mustela vison (Schreber, 1777) is cited for the first time, and the wolf reappears as a non-occasional species. The main trends observed during the last twelve years seem to be related to changes in land use and management of natural resources. The situation has turned favourable for the most opportunistic species, which have become very abundant in some areas, while populations of the most specialist or relictic species show a more restricted distribution. At the same time, the expansion of wolf and European mink, with the appearance of American mink for the first time, reflect a dynamic but very unstable scene.
Key words: Carnivores, Population status, Distribution, Conservation, lberian peninsula.The first study on the carnivore community of Biscay was published in 1985. The present study, made twelve years later, was carried out to assess the present situation of these mammals. In this work, data collected from 1990 to 1996 by trapping, sighting, and surveying road and other kills, as well as faeces and tracks are reported. Records of 12 species were obtained, of which American mink Mustela vison (Schreber, 1777) is cited for the first time, and the wolf reappears as a non-occasional species. The main trends observed during the last twelve years seem to be related to changes in land use and management of natural resources. The situation has turned favourable for the most opportunistic species, which have become very abundant in some areas, while populations of the most specialist or relictic species show a more restricted distribution. At the same time, the expansion of wolf and European mink, with the appearance of American mink for the first time, reflect a dynamic but very unstable scene.
Key words: Carnivores, Population status, Distribution, Conservation, lberian peninsula.The first study on the carnivore community of Biscay was published in 1985. The present study, made twelve years later, was carried out to assess the present situation of these mammals. In this work, data collected from 1990 to 1996 by trapping, sighting, and surveying road and other kills, as well as faeces and tracks are reported. Records of 12 species were obtained, of which American mink Mustela vison (Schreber, 1777) is cited for the first time, and the wolf reappears as a non-occasional species. The main trends observed during the last twelve years seem to be related to changes in land use and management of natural resources. The situation has turned favourable for the most opportunistic species, which have become very abundant in some areas, while populations of the most specialist or relictic species show a more restricted distribution. At the same time, the expansion of wolf and European mink, with the appearance of American mink for the first time, reflect a dynamic but very unstable scene.
Key words: Carnivores, Population status, Distribution, Conservation, lberian peninsula
Molecular rearrangement of an Aza-Scorpiand macrocycle induced by pH: A computational study
Rearrangements and their control are a hot topic in supramolecular chemistry due to the possibilities that these phenomena open in the design of synthetic receptors and molecular machines. Macrocycle aza-scorpiands constitute an interesting system that can reorganize their spatial structure depending on pH variations or the presence of metal cations. In this study, the relative stabilities of these conformations were predicted computationally by semi-empirical and density functional theory approximations, and the reorganization from closed to open conformations was simulated by using the Monte Carlo multiple minimum method
Quantifying Reproducibility in Computational Biology: The Case of the Tuberculosis Drugome
How easy is it to reproduce the results found in a typical computational biology paper? Either through experience or intuition the reader will already know that the answer is with difficulty or not at all. In this paper we attempt to quantify this difficulty by reproducing a previously published paper for different classes of users (ranging from users with little expertise to domain experts) and suggest ways in which the situation might be improved. Quantification is achieved by estimating the time required to reproduce each of the steps in the method described in the original paper and make them part of an explicit workflow that reproduces the original results. Reproducing the method took several months of effort, and required using new versions and new software that posed challenges to reconstructing and validating the results. The quantification leads to “reproducibility maps” that reveal that novice researchers would only be able to reproduce a few of the steps in the method, and that only expert researchers with advance knowledge of the domain would be able to reproduce the method in its entirety. The workflow itself is published as an online resource together with supporting software and data. The paper concludes with a brief discussion of the complexities of requiring reproducibility in terms of cost versus benefit, and a desiderata with our observations and guidelines for improving reproducibility. This has implications not only in reproducing the work of others from published papers, but reproducing work from one’s own laboratory
Synthesis and characterization of graphene/polythiophene (GR/PT) nanocomposites:Evaluation as high-performance supercapacitor electrodes
Composites of polythiophene (PT) and graphene (GR) with different mass proportions were studied for their application as supercapacitors. Fourier transform infrared spectroscopy (FTIR) along with High Resolution Scanning electron microscopy (HR-SEM) were employed in order to characterize the morphology and composition of the resulting composites. The electrochemical behaviour of these composites was studied by means of cyclic voltammetry and specific capacitance curves were derived from these measurements. The Faradaic impedance spectroscopy response of the different composites, along with that of GR, was also studied. From these measurements it was found that a 1:1 in mass composite of GR and PT showed a higher specific capacitance, even when compared with GR alone. The introduction of the GR in that proportion also showed an enhanced cyclic stability in comparison with the sole polymer. The high specific capacitance (365 F g-1 at 1 A g-1) of this composite material indicates its potential for use as an electrode material for supercapacitors.Fil: Melo, J. P.. Universidad Bernardo OHiggins; ChileFil: Schulz, Eduardo Nicolás. Universidad Nacional del Sur. Departamento de Ingeniería Química. Instituto de Ingeniería Electroquímica y Corrosión; Argentina. University of Birmingham; Reino UnidoFil: Morales Verdejo, C.. Universidad Bernardo OHiggins; ChileFil: Horswell, S. L.. University of Birmingham; Reino UnidoFil: Camarada, M. B.. Universidad Bernardo OHiggins; Chil
White Matter Integrity, Creativity, and Psychopathology: Disentangling Constructs with Diffusion Tensor Imaging
That creativity and psychopathology are somehow linked remains a popular but controversial idea in neuroscience research. Brain regions implicated in both psychosis-proneness and creative cognition include frontal projection zones and association fibers. In normal subjects, we have previously demonstrated that a composite measure of divergent thinking (DT) ability exhibited significant inverse relationships in frontal lobe areas with both cortical thickness and metabolite concentration of N-acetyl-aspartate (NAA). These findings support the idea that creativity may reside upon a continuum with psychopathology. Here we examine whether white matter integrity, assessed by Fractional Anisotropy (FA), is related to two measures of creativity (Divergent Thinking and Openness to Experience). Based on previous findings, we hypothesize inverse correlations within fronto-striatal circuits. Seventy-two healthy, young adult (18–29 years) subjects were scanned on a 3 Tesla scanner with Diffusion Tensor Imaging. DT measures were scored by four raters (α = .81) using the Consensual Assessment Technique, from which a composite creativity index (CCI) was derived. We found that the CCI was significantly inversely related to FA within the left inferior frontal white matter (t = 5.36, p = .01), and Openness was inversely related to FA within the right inferior frontal white matter (t = 4.61, p = .04). These findings demonstrate an apparent overlap in specific white matter architecture underlying the normal variance of divergent thinking, openness, and psychotic-spectrum traits, consistent with the idea of a continuum
Exploiting the Hierarchical Structure of Rule-Based Specifications for Decision Planning
Rule-based specifications have been very successful as a declarative approach in many domains, due to the handy yet solid foundations offered by rule-based machineries like term and graph rewriting. Realistic problems, however, call for suitable techniques to guarantee scalability. For instance, many domains exhibit a hierarchical structure that can be exploited conveniently. This is particularly evident for composition associations of models. We propose an explicit representation of such structured models and a methodology that exploits it for the description and analysis of model- and rule-based systems. The approach is presented in the framework of rewriting logic and its efficient implementation in the rewrite engine Maude and is illustrated with a case study.
Algorithms applied for monitoring pelagic Sargassum
Massive arrivals of pelagic Sargassum to the coasts of several countries in the Atlantic Ocean began in 2011. Monitoring the abundance and distribution of Sargassum in the ocean and along the coasts is necessary to understand the phenomena better and develop forecasting products and management protocols. Most Sargassum monitoring has been conducted in the open ocean through traditional remote sensing techniques. However, since the most significant ecologic and socioeconomic impacts occur on the coasts, it is necessary to monitor these macroalgae on nearshore waters and beaches. This manuscript reviews the remote sensing algorithms used in Sargassum observation reported in the last 17 years in more than sixty high-impact scientific publications. The discussion regarding the evolution of the methodologies used for monitoring these macroalgae allowed us to conclude that the synergy generated by incorporating new disciplines like artificial intelligence and citizen science has positively impacted the development of this field. Additionally, the current state-of-the-art methods, the fundamental challenges, and the directions for future research are also discussed
Investigating the Mechanisms of Hallucinogen-Induced Visions Using 3,4-Methylenedioxyamphetamine (MDA): A Randomized Controlled Trial in Humans
The mechanisms of drug-induced visions are poorly understood. Very few serotonergic hallucinogens have been studied in humans in decades, despite widespread use of these drugs and potential relevance of their mechanisms to hallucinations occurring in psychiatric and neurological disorders.We investigated the mechanisms of hallucinogen-induced visions by measuring the visual and perceptual effects of the hallucinogenic serotonin 5-HT2AR receptor agonist and monoamine releaser, 3,4-methylenedioxyamphetamine (MDA), in a double-blind placebo-controlled study. We found that MDA increased self-report measures of mystical-type experience and other hallucinogen-like effects, including reported visual alterations. MDA produced a significant increase in closed-eye visions (CEVs), with considerable individual variation. Magnitude of CEVs after MDA was associated with lower performance on measures of contour integration and object recognition.Drug-induced visions may have greater intensity in people with poor sensory or perceptual processing, suggesting common mechanisms with other hallucinatory syndromes. MDA is a potential tool to investigate mystical experiences and visual perception
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