1,809 research outputs found
Evaluación preliminar del riesgo sanitario por agroquímicos en aguas del Arroyo Azul, provincia de Buenos Aires
Health risk analyses (HRA) indicate whether, and to which extent of severity, a given chemical substance may constitute a threat for health, e.g., the accidental ingestion of water during recreational use with direct contact. Objectives of this paper are to estimate the risk from an accidental ingestion of water carrying agrichemicals (á y ä HCH, Aldrine, ã – Chlordane, Glyphosate, and Imazethapyr) while bathing in the Azul River bathing resort by making use of HRA, and to discuss the potential use of such a tool for water resources management.
It is based on the USEPA model, and, with the exception of the concentration of the substance in water, all other variables (ingestion rate, weight of individuals, frequency and duration of the exposition) are treated probabilistically and fit a recreational scenario with direct contact. The aggregated risk is estimated with an additive model of the particular risk of each substance. Results show that the risk, non carcinogenetic effects, may be disregarded because its value is always less than 1 (Aldrine is the principal contributor). Regarding the carcinogenetic effects, although the value is slightly greater than the limiting value of 10-5, the conservative approach of this study makes it to be minimized (its principal contributor is á –HCH). The Buenos Aires Province does not count with regulations referred to the quality of natural waters used for bathing. For that reason, the HRA stand out as an option for decision-makers given the absence of alternative management strategies.Facultad de Ciencias Naturales y Muse
Evaluación preliminar del riesgo sanitario por agroquímicos en aguas del Arroyo Azul, provincia de Buenos Aires
Health risk analyses (HRA) indicate whether, and to which extent of severity, a given chemical substance may constitute a threat for health, e.g., the accidental ingestion of water during recreational use with direct contact. Objectives of this paper are to estimate the risk from an accidental ingestion of water carrying agrichemicals (á y ä HCH, Aldrine, ã – Chlordane, Glyphosate, and Imazethapyr) while bathing in the Azul River bathing resort by making use of HRA, and to discuss the potential use of such a tool for water resources management.
It is based on the USEPA model, and, with the exception of the concentration of the substance in water, all other variables (ingestion rate, weight of individuals, frequency and duration of the exposition) are treated probabilistically and fit a recreational scenario with direct contact. The aggregated risk is estimated with an additive model of the particular risk of each substance. Results show that the risk, non carcinogenetic effects, may be disregarded because its value is always less than 1 (Aldrine is the principal contributor). Regarding the carcinogenetic effects, although the value is slightly greater than the limiting value of 10-5, the conservative approach of this study makes it to be minimized (its principal contributor is á –HCH). The Buenos Aires Province does not count with regulations referred to the quality of natural waters used for bathing. For that reason, the HRA stand out as an option for decision-makers given the absence of alternative management strategies.Facultad de Ciencias Naturales y Muse
Evaluación preliminar del riesgo sanitario por agroquímicos en aguas del arroyo Azul, provincia de Buenos Aires
Health risk analyses (HRA) indicate whether, and to which extent of severity, a given chemical substance may constitute a threat for health, e.g., the accidental ingestion of water during recreational use with direct contact. Objectives of this paper are to estimate the risk from an accidental ingestion of water carrying agrichemicals (á y ä HCH, Aldrine, ã – Chlordane, Glyphosate, and Imazethapyr) while bathing in the Azul River bathing resort by making use of HRA, and to discuss the potential use of such a tool for water resources management. It is based on the USEPA model, and, with the exception of the concentration of the substance in water, all other variables (ingestion rate, weight of individuals, frequency and duration of the exposition) are treated probabilistically and fit a recreational scenario with direct contact. The aggregated risk is estimated with an additive model of the particular risk of each substance. Results show that the risk, non carcinogenetic effects, may be disregarded because its value is always less than 1 (Aldrine is the principal contributor). Regarding the carcinogenetic effects, although the value is slightly greater than the limiting value of 10-5, the conservative approach of this study makes it to be minimized (its principal contributor is á –HCH). The Buenos Aires Province does not count with regulations referred to the quality of natural waters used for bathing. For that reason, the HRA stand out as an option for decision-makers given the absence of alternative management strategies.Facultad de Ciencias Naturales y Muse
Evaluación preliminar del riesgo sanitario por agroquímicos en aguas del Arroyo Azul, provincia de Buenos Aires
Health risk analyses (HRA) indicate whether, and to which extent of severity, a given chemical substance may constitute a threat for health, e.g., the accidental ingestion of water during recreational use with direct contact. Objectives of this paper are to estimate the risk from an accidental ingestion of water carrying agrichemicals (á y ä HCH, Aldrine, ã – Chlordane, Glyphosate, and Imazethapyr) while bathing in the Azul River bathing resort by making use of HRA, and to discuss the potential use of such a tool for water resources management.
It is based on the USEPA model, and, with the exception of the concentration of the substance in water, all other variables (ingestion rate, weight of individuals, frequency and duration of the exposition) are treated probabilistically and fit a recreational scenario with direct contact. The aggregated risk is estimated with an additive model of the particular risk of each substance. Results show that the risk, non carcinogenetic effects, may be disregarded because its value is always less than 1 (Aldrine is the principal contributor). Regarding the carcinogenetic effects, although the value is slightly greater than the limiting value of 10-5, the conservative approach of this study makes it to be minimized (its principal contributor is á –HCH). The Buenos Aires Province does not count with regulations referred to the quality of natural waters used for bathing. For that reason, the HRA stand out as an option for decision-makers given the absence of alternative management strategies.Health risk analyses (HRA) indicate whether, and to which extent of severity, a given chemical substance may constitute a threat for health, e.g., the accidental ingestion of water during recreational use with direct contact. Objectives of this paper are to estimate the risk from an accidental ingestion of water carrying agrichemicals (á y ä HCH, Aldrine, ã – Chlordane, Glyphosate, and Imazethapyr) while bathing in the Azul River bathing resort by making use of HRA, and to discuss the potential use of such a tool for water resources management. It is based on the USEPA model, and, with the exception of the concentration of the substance in water, all other variables (ingestion rate, weight of individuals, frequency and duration of the exposition) are treated probabilistically and fit a recreational scenario with direct contact. The aggregated risk is estimated with an additive model of the particular risk of each substance. Results show that the risk, non carcinogenetic effects, may be disregarded because its value is always less than 1 (Aldrine is the principal contributor). Regarding the carcinogenetic effects, although the value is slightly greater than the limiting value of 10-5, the conservative approach of this study makes it to be minimized (its principal contributor is á –HCH). The Buenos Aires Province does not count with regulations referred to the quality of natural waters used for bathing. For that reason, the HRA stand out as an option for decision-makers given the absence of alternative management strategies
Hacia una agenda de investigación sobre la relación entre capital social y turismo
The present study conducts a reflective analysis of academic production about the relationship between tourism and social capital, with the aim of responding to the question: What are the themes, variables and paths that the study of social capital ought to follow in the tourism sphere? It became clear that although there is relevant academic production regarding the relationship between tourism and social capital, the entire range of the possibilities for its study and understanding has still not been covered, which in addition limits its academic knowledge, the possibility of designing intervention actions that could have an impact on the improvement of tourism or of social capital in societies where they participate, or in both. The elements to be considered when approaching a research agenda are presented, in order to delve into the knowledge of the relationship between tourism and social capital as theoretical-conceptual framework, that is, stemming from the type of relationship between the themes, the scenarios to be considered, the scales to approach the studies, the actors to be included, and the dimensions, categories, themes or variables to be considered. Finally, reflections are made about what has been researched until today, and the different scientific academic work lines that can be pursued in the future.
El presente ensayo, realiza un análisis reflexivo de la producción académica sobre la relación entre turismo y capital social, con la finalidad de responder a la interrogante ¿cuáles son las temáticas, variables y rumbos que ha de seguir el estudio del capital social en el ámbito turístico? Se encontró que, si bien existe producción académica importante respecto a la relación entre turismo y capital social, aún no se ha cubierto toda la gama de posibilidades para su estudio y comprensión, lo cual limita además de su conocimiento académico, la posibilidad de diseñar acciones de intervención que incidan en la mejora de la propia actividad turística o del capital social en las sociedades que en él participan o en ambos. Se presentan los elementos a considerar al abordar una agenda de investigación para profundizar en el conocimiento de la relación entre turismo y capital social como marco teórico-conceptual, a saber, desde el tipo de relación entre las temáticas, los escenarios a considerar, las escalas para abordar los estudios, los actores a incluir y las dimensiones, categorías, temáticas o variables a considerar. Finalmente se hacen reflexiones sobre lo que hasta el momento se ha investigado y las distintas líneas de trabajo académico científico que pueden seguirse en el futuro
Molecular dynamics simulation of the behaviour of water in nano-confined ionic liquid-water mixtures.
This work describes the behaviour of water molecules in 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid under nanoconfinement, between graphene sheets. By means of molecular dynamics simulations, the adsorption of water molecules at the graphene surface is studied. A depletion of water molecules in the vicinity of the neutral and negatively charged graphene surfaces, and their adsorption at the positively charged surface are observed in line with the preferential hydration of the ionic liquid anions. The findings are appropriately described using a two-level statistical model. The confinement effect on the structure and dynamics of the mixtures is thoroughly analyzed using the density and the potential of mean force profiles, as well as by the vibrational densities of the states of water molecules near the graphene surface. The orientation of water molecules and the water-induced structural transitions in the layer closest to the graphene surface are also discussed.We acknowledge the supercomputing support from the EPSRC funded ARCHIE-WeSt HighPerformance Computer centre (www.archie-west.ac.uk, EPSRC grant no. EP/K000586/1) and the Galician Supercomputing Centre (CESGA). The financial support of the Estonian Materials Technology Program Project SLOKT12180T, Project of European Structure Funds SLOKT12026T, Estonian Institutional Research Project IUT20-013, Estonian Personal Research Project PUT1107, and Estonian Centres of Excellence in Science Project: High-technology Materials for Sustainable Development TK117 is highly appreciated. The financial support of the Spanish Ministry of Economy and Competitiveness MAT2014-57943-C3-1-P and MAT2014- 57943-C3-3-P is gratefully acknowledged. Moreover, this work was funded by the Spanish Ministry of Economy and Competitiveness (FIS2012-33126) and by the Xunta de Galicia (AGRUP2015/11). All these research projects were partially supported by FEDER. Funding from the European Union (COST Action CM 1206) and by the Galician Network on Ionic Liquids, REGALIs (CN 2014/015) is also acknowledged
Protocolo neuropsicopedagógico en la evaluación multidimensional del trastorno por déficit atencional/hiperactividad –TDAH–: Implementación de una experiencia investigativa.
Avances investigativos generados en la especialización en neuropsicopedagogía, adscrita al Programa de Psicología de la Facultad de Ciencias Sociales y Humanas de la Universidad de Manizales, permitieron proponer una aproximación multidimensional precisa, objetiva e integral para la caracterización neuropsicopedagógica de niños y niñas con Trastorno por Déficit Atencional/Hiperactividad –TDAH–. Dicha aproximación contempla también la evaluación neurofisiológica por medio de potenciales evocados cognitivos y la posibilidad de realizar un análisis automatizado de las bioseñales obtenidas. Lo anterior constituye una herramienta fundamental para implementar procesos de identificación del TDAH y para posteriores estudios sobre desórdenes de comportamiento en la población infantil. En particular, con la sistematización de perfiles neuropsicopedagógicos se pretende arrojar datos potencialmente útiles para el desarrollo de un sistema de evaluación informatizado con aplicabilidad en los campos clínico y educativo, lo cual permitirá no solo un mejor conocimiento del trastorno, sino también mejores criterios predictivos sobre el pronóstico y la respuesta de planes de intervención establecidos, entre otros. En este artículo se presentan los componentes que permitieron estructurar el protocolo neuropsicopedagógico y la articulación de los componentes neurofisiológicos y biomédicos, así como algunos resultados preliminares en cada uno de dichos componentes
The intrinsic shape of galaxy bulges
The knowledge of the intrinsic three-dimensional (3D) structure of galaxy
components provides crucial information about the physical processes driving
their formation and evolution. In this paper I discuss the main developments
and results in the quest to better understand the 3D shape of galaxy bulges. I
start by establishing the basic geometrical description of the problem. Our
understanding of the intrinsic shape of elliptical galaxies and galaxy discs is
then presented in a historical context, in order to place the role that the 3D
structure of bulges play in the broader picture of galaxy evolution. Our
current view on the 3D shape of the Milky Way bulge and future prospects in the
field are also depicted.Comment: Invited Review to appear in "Galactic Bulges" Editors: Laurikainen
E., Peletier R., Gadotti D. Springer Publishing. 24 pages, 7 figure
Calibration of the Logarithmic-Periodic Dipole Antenna (LPDA) Radio Stations at the Pierre Auger Observatory using an Octocopter
An in-situ calibration of a logarithmic periodic dipole antenna with a
frequency coverage of 30 MHz to 80 MHz is performed. Such antennas are part of
a radio station system used for detection of cosmic ray induced air showers at
the Engineering Radio Array of the Pierre Auger Observatory, the so-called
Auger Engineering Radio Array (AERA). The directional and frequency
characteristics of the broadband antenna are investigated using a remotely
piloted aircraft (RPA) carrying a small transmitting antenna. The antenna
sensitivity is described by the vector effective length relating the measured
voltage with the electric-field components perpendicular to the incoming signal
direction. The horizontal and meridional components are determined with an
overall uncertainty of 7.4^{+0.9}_{-0.3} % and 10.3^{+2.8}_{-1.7} %
respectively. The measurement is used to correct a simulated response of the
frequency and directional response of the antenna. In addition, the influence
of the ground conductivity and permittivity on the antenna response is
simulated. Both have a negligible influence given the ground conditions
measured at the detector site. The overall uncertainties of the vector
effective length components result in an uncertainty of 8.8^{+2.1}_{-1.3} % in
the square root of the energy fluence for incoming signal directions with
zenith angles smaller than 60{\deg}.Comment: Published version. Updated online abstract only. Manuscript is
unchanged with respect to v2. 39 pages, 15 figures, 2 table
Azimuthal asymmetry in the risetime of the surface detector signals of the Pierre Auger Observatory
The azimuthal asymmetry in the risetime of signals in Auger surface detector
stations is a source of information on shower development. The azimuthal
asymmetry is due to a combination of the longitudinal evolution of the shower
and geometrical effects related to the angles of incidence of the particles
into the detectors. The magnitude of the effect depends upon the zenith angle
and state of development of the shower and thus provides a novel observable,
, sensitive to the mass composition of cosmic rays
above eV. By comparing measurements with predictions from
shower simulations, we find for both of our adopted models of hadronic physics
(QGSJETII-04 and EPOS-LHC) an indication that the mean cosmic-ray mass
increases slowly with energy, as has been inferred from other studies. However,
the mass estimates are dependent on the shower model and on the range of
distance from the shower core selected. Thus the method has uncovered further
deficiencies in our understanding of shower modelling that must be resolved
before the mass composition can be inferred from .Comment: Replaced with published version. Added journal reference and DO
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