1,341 research outputs found
Multiwavelength study of the starburst galaxy NGC7714. I: Ultraviolet-Optical spectroscopy
We have studied the physical conditions in the central 300 pc of the
proto-typical starburst galaxy NGC 7714. Our analysis is based on ultraviolet
spectroscopy with the HST+GHRS and ground-based optical observations.The data
are interpreted using evolutionary models optimized for young starburst
regions. The massive stellar population is derived in a self-consistent way
using the continuum and stellar absorption lines in the ultraviolet and the
nebular emission line optical spectrum.
The central starburst has an age of about 4.5 Myr, with little evidence for
an age spread. Wolf-Rayet features at the ultraviolet indicates a stellar
population of 2000 Wolf-Rayet stars. The overall properties of the newly
formed stars are quite similar to those derived, e.g., in 30 Doradus. A
standard Salpeter IMF is consistent with all observational constraints. We find
evidence for spatial structure within the central 300 pc sampled. Therefore it
is unlikely that the nucleus of NGC 7714 hosts a single star cluster exceeding
the properties of other known clusters. Contrary to previous suggestions, we
find no evidence for a nuclear supernova rate that would significantly exceed
the total disk-integrated rate. About one supernova event per century is
predicted.Comment: 19 pages, 9 figures in a tar file. Accepted for publication in ApJ,
1999, March, issue 51
Desarrollo multidisciplinario en investigación y docencia del centro universitario UAEM Valle de México
DESARROLLO MULTIDISCIPLINARIO EN INVESTIGACIÓN Y DOCENCIA DEL CENTRO UNIVERSITARIO UAEM VALLE DE MÉXICOLa Universidad Autónoma del Estado de México ha evolucionado a través de sus 188 años de historia, dedicada a la educación, la investigación, la cultura y el deporte, como sus grandes ejes rectores, formadora de hombres y mujeres con un alto sentido humanista y ético, contribuyendo a lograr nuevas y mejores formas de existencia y convivencia social. Durante el proceso de desconcentración de la UAEM, se crearon las Unidades Académicas y Centros Universitarios para brindar el servicio de educación a más jóvenes en todo el Estado de México, este Centro Universitario fue uno de los primeros y a sus veinte años de existencia se está consolidando como uno de los mejores. Es en los últimos años que se ha venido impulsando la investigación al contar con cuerpos académicos, en formación y en consolidación, con infraestructura de primera tanto en equipo como en laboratorios especializados, con profesores de tiempo completo que participan en congresos, seminarios y presentan publicaciones en revistas indexadas. Por ello para celebrar esos veinte años de existencia de esta honorable institución, se planeó la compilación de esta obra que es parte del quehacer multidisciplinario en investigación y docencia como parte del Plan de Desarrollo 2013-2017, de esta administración. Esta obra reúne investigaciones tanto de profesores como de alumnos desde las diferentes ramas del saber en las que se inscriben sus siete licenciaturas, Actuaría, Administración, Contaduría, Derecho, Economía, Relaciones Económicas Internacionales e Informática Administrativa, tanto presencial como a distancia, así como sus tres ingenierías, Industrial, en Computación y Sistemas y Comunicaciones, así como gracias a la vinculación y colaboración académico – científica que se tiene con otras instituciones de educación superior a nivel nacional, como el Instituto Tecnológico de Orizaba, la Universidad Autónoma de San Luis Potosí, la Universidad Nacional Autónoma de México, la Universidad Autónoma Metropolitana, Universidad Politécnica de Victoria, el Instituto Politécnico Nacional entre otras. En el capítulo 1 se abordan seis temáticas diferentes de vanguardia en el área de las Ingenierías, en los capítulos 2 y 3 se incluyen temas de interés y gran relevancia en materia de ciencias sociales, política y economía. Se hace extensivo un reconocimiento para todos los que participaron tanto en la revisión de los trabajos, como en la compilación del producto final de este Libro intitulado “Desarrollo Multidisciplinario en Investigación y Docencia del Centro Universitario UAEM Valle de México”
Compartiendo saberes de educación y humanidades
Los capítulos referentes a este libro tratan diversos temas tales como: 1) la construcción de los estudiantes de la licenciatura en químico farmacéutico biólogo el juicio valorativo y personaI deI significado en su desarroIIo profesionaI desde eI punto de vista axiológico, 2) se realiza un estudio en el Plantel Cuauhtémoc con Ia finaIidad de orientar a Ia comunidad estudiantiI aI tratamiento deI probIema de los residuos sólidos desde su etapa de diagnóstico hasta una propuesta de solución de la problemática, 3) se analiza como a nivel básico se construye el conocimiento y la participación del género en los estudiantes, en donde se observa que el papel del docente es un promotor importante, 4) es un tema que actualmente está causando mucho interés tanto en la educación como el la población en general, las redes sociales que actuaImente ese consideran un medio de comunicación con mucha influencia dentro de la sociedad, 5) se adentra al campo de la psicología y la tanatología ante los recursos resilientes que presentan las familias ante la muerte de un hijo, 6) es una investigación dedicada a identificar Ias diferentes percepciones que tienen las mujeres y los hombres en relación a la felicidad y la desdicha dentro del matrimonio, 7) es un análisis Transgeneracional para aportar las referencias familiares que permiten la permanencia del abuso sexual infantil en tres generaciones, de las cuales en la última generación se rompe ese secreto avallazador al romper el silencio, 8) es un ensayo acerca del juego terapéutico desde el punto de vista psicoanalítico, en el que se advierte ese juego en el que entra el paciente con el psicoanalista, 9) la metodología de la observación para la integración de la pericial en psicología, en donde se denotan desde la parte jurídica como se fundamente esta pericial y fortalece el logro del dictamen para tener un buen dictamen, 10) es una propuesta de construcción y validez del instrumento BP-22 Bienestar Psicológico en el ámbito de la educación superior, 11) se identifica a Ios procesos eIectoraIes como complicados, de tal manera que abre un panorama al marketing de los partidos políticos para conducir la voluntad ciudadana, y además ayuda al posicionamiento de los partidos, 12) aporta una base sobre Ios procesos identificatorios en eI movimiento estudiantiI de Ia UNAM deI año de I999, pIanteándoIo desde dos ejes de análisis: las identidades universitarias y el apartado del texto, que permiten configurar eI movimiento estudiantiI como un acontecimiento capaz de generar articulaciones nuevas de solidaridad. AI finaI deI Iibro se encuentran Ias síntesis curricuIares de cada uno de los autores, que aportaron sus investigaciones para la integración y generación de nuevos aportes científicos.Como su nombre lo indica COMPARTIENDO SABERES DE EDUCACIÓN Y HUMANIDADES, es un Iibro que denota eI deseo de integrar conocimiento para la comunidad estudiantil, llevarlos al interés de la investigación a través de la participación de los investigadores de diferentes áreas como: la educación, las ciencias sociales y las humanidades. Que les permite tener no solo un espacio en la difusión de los avances de sus estudios, sino que además permite el generar el interés de quién lo lee en diferentes formas de investigación, se encuentran estudios tanto cualitativos como cuantitativos, desde descriptivos hasta un nivel de intervención en la práctica de estas áreas.Universidad Autónoma del Estado de méxic
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy
We measure the energy emitted by extensive air showers in the form of radio
emission in the frequency range from 30 to 80 MHz. Exploiting the accurate
energy scale of the Pierre Auger Observatory, we obtain a radiation energy of
15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV
arriving perpendicularly to a geomagnetic field of 0.24 G, scaling
quadratically with the cosmic-ray energy. A comparison with predictions from
state-of-the-art first-principle calculations shows agreement with our
measurement. The radiation energy provides direct access to the calorimetric
energy in the electromagnetic cascade of extensive air showers. Comparison with
our result thus allows the direct calibration of any cosmic-ray radio detector
against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI.
Supplemental material in the ancillary file
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
Father's occupational exposure to carcinogenic agents and childhood acute leukemia: a new method to assess exposure (a case-control study)
<p>Abstract</p> <p>Background</p> <p>Medical research has not been able to establish whether a father's occupational exposures are associated with the development of acute leukemia (AL) in their offspring. The studies conducted have weaknesses that have generated a misclassification of such exposure. Occupations and exposures to substances associated with childhood cancer are not very frequently encountered in the general population; thus, the reported risks are both inconsistent and inaccurate. In this study, to assess exposure we used a new method, an exposure index, which took into consideration the industrial branch, specific position, use of protective equipment, substances at work, degree of contact with such substances, and time of exposure. This index allowed us to obtain a grade, which permitted the identification of individuals according to their level of exposure to known or potentially carcinogenic agents that are not necessarily specifically identified as risk factors for leukemia. The aim of this study was to determine the association between a father's occupational exposure to carcinogenic agents and the presence of AL in their offspring.</p> <p>Methods</p> <p>From 1999 to 2000, a case-control study was performed with 193 children who reside in Mexico City and had been diagnosed with AL. The initial sample-size calculation was 150 children per group, assessed with an expected odds ratio (OR) of three and a minimum exposure frequency of 15.8%. These children were matched by age, sex, and institution with 193 pediatric surgical patients at secondary-care hospitals. A questionnaire was used to determine each child's background and the characteristics of the father's occupation(s). In order to determine the level of exposure to carcinogenic agents, a previously validated exposure index (occupational exposure index, OEI) was used. The consistency and validity of the index were assessed by a questionnaire comparison, the sensory recognition of the work area, and an expert's opinion.</p> <p>Results</p> <p>The adjusted ORs and 95% confidence intervals (CI) were 1.69 (0.98, 2.92) during the preconception period; 1.98 (1.13, 3.45) during the index pregnancy; 2.11 (1.17, 3.78) during breastfeeding period; 2.17 (1.28, 3.66) after birth; and 2.06 (1.24, 3.42) for global exposure.</p> <p>Conclusion</p> <p>This is the first study in which an OEI was used to assess a father's occupational exposure to carcinogenic agents as a risk factor for the development of childhood AL in his offspring. From our results, we conclude that children whose fathers have been exposed to a high level of carcinogenic agents seem to have a greater risk of developing acute leukemia. However, confounding factors cannot be disregarded due to an incomplete control for confounding.</p
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