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Search Results: 1 - 10 of 25970 matches for " MARCO; RUIZ-VELASCO "
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Efecto de la contaminación ambiental sobre las consultas por infecciones respiratorias en ni os de la Ciudad de México
TéLLES-ROJO MARTHA MARíA,ROMIEU ISABELLE,POLO-PE?A MARCO,RUIZ-VELASCO SILVIA
Salud Pública de México , 1997,
Abstract: Objetivo. Modelar la variabilidad en el número de consultas infantiles diarias por motivos respiratorios como consecuencia de los cambios diarios en los niveles de contaminación ambiental, observada en los servicios de urgencias y medicina familiar de un hospital de especialidades del Instituto Mexicano del Seguro Social ubicado en la zona suroeste de la Ciudad de México durante 1993. Material y métodos. Se estudió la correlación entre la presencia de infecciones respiratorias altas y bajas con la exposición a ozono y bióxido de nitrógeno. Para modelar esta asociación se utilizó la técnica de regresión Poisson aplicada sobre modelos de riesgo lineal y no lineal con periodos de latencia entre las mediciones ambientales y la consulta de uno, dos y tres días, así como el promedio de las mediciones de los tres, cinco y siete días previos a la consulta. Resultados. El modelo utilizado estima que un incremento de 50 ppb en el promedio horario de ozono de un día ocasionaría, al día siguiente, un incremento del 9.9% en las consultas de urgencias por infecciones respiratorias altas en el periodo invernal, pudiendo incrementarse hasta en un 30% si el incremento se diera en cinco días consecutivos como promedio. Conclusiones. Los resultados sugieren que la exposición de los menores de 15 a os al ozono y bióxido de nitrógeno inciden significativamente sobre el número de consultas ocasionadas por motivos respiratorios en esta zona de la Ciudad de México.
Efecto de la contaminación ambiental sobre las consultas por infecciones respiratorias en ni?os de la Ciudad de México
TéLLES-ROJO,MARTHA MARíA; ROMIEU,ISABELLE; POLO-PE?A,MARCO; RUIZ-VELASCO,SILVIA; MENESES-GONZáLEZ,FERNANDO; HERNáNDEZ-AVILA,MAURICIO;
Salud Pública de México , 1997, DOI: 10.1590/S0036-36341997000600004
Abstract: objective. to model the variability of medical visits by children for respiratory reasons as a consequence of the daily changes in environmental pollution observed in the emergency and family medicine departments of a hospital of the instituto mexicano del seguro social located in the southwest of mexico city during 1993. materials and methods. the correlation between the presence of upper and lower respiratory tract infections and exposure to ozone and nitrogen dioxide was studied. to model this association, the authors used multivariate poisson regression models with linear and non-linear risk, with lag periods between the environmental measurements and the medical visits of one, two and three days, as well as the average of the measurements of three, five and seven days previous to the visit. results. the model estimates that an increment of 50 ppb in the daily average of ozone would cause an increase of 9.9% in emergency visits due to high respiratory tract infections during the winter, which could rise to 30% if the increment would last five consecutive days in average. conclusions. results suggest that exposure of children younger than 15 years of age to ozone and nitrogen dioxide significantly affect the number of medical visits for respiratory causes in this part of mexico city.
Near-infrared spectro-interferometry of three OH/IR Stars with the VLTI/AMBER instrument
A. E. Ruiz-Velasco,M. Wittkowski,A. Wachter,K. -P. Schroeder,T. Driebe
Physics , 2011, DOI: 10.1051/0004-6361/201117994
Abstract: We investigate the molecular and dusty environment of OH/IR stars in order to characterize the mass-loss process during the tip-AGB superwind phase. Employing the AMBER instrument at the VLT Interferometer we obtained near-infrared H- and K-band spectro-interferometric observations of the three OH/IR stars IRAS 13479-5436, IRAS 14086-6907 and IRAS 17020-5254 with a spectral resolution of about 35. We use a two-component geometrical model, consisting of a uniform disk and a Gaussian disk, to obtain characteristic angular sizes of the central stellar sources and their dust envelopes, as well as the flux ratios between these components. Angular uniform disk diameters of the three central components of the objects above have values between 3.2 mas and 5.4 mas. For their dust envelopes, we find FWHM values between 17.1 mas and 25.2 mas. According to distance estimates from the literature, the central stellar components have radii between 900 R_sun and 1400 R_sun, while their dust envelopes reach FWHM values between 9000 R_sun and 13000 R_sun. The visibility functions of all three sources exhibit wavelength variations that resemble those of earlier VLTI/AMBER observations of semi-regular and Mira variable AGB stars. These are interpreted as characteristic of atmospheric molecular layers lying above the photosphere. We also find that the dust envelopes have a clearly larger optical depth than those known for Mira stars. We interpret this as an expected result of the "superwind" phase, the final 10 000 to 30 000 years of AGB-evolution, when the mass-loss rate increases by a factor of 10-100. By their different optical depths, the three dust shells studied here may represent different stages of the "superwind" and different initial masses.
El acoso escolar (bullying) y su asociación con trastornos psiquiátricos en una muestra de escolares en México
Albores-Gallo,Lilia; Sauceda-García,Juan Manuel; Ruiz-Velasco,Silvia; Roque-Santiago,Eduardo;
Salud Pública de México , 2011, DOI: 10.1590/S0036-36342011000300006
Abstract: objective: to study the relationship between bullying behavior and psychopathology. materials and methods: a total of 1 092 students identified their peers' bullying status based on the bull-s questionnaire. parents completed the child behavior checklist (cbcl) to determine psychopathology levels. results: the bullying group had associations with anxiety, somatic symptoms, oppositionalism and behavior problems; the bully-victims group had associations with attention, oppositionalism and behavior problems; victims had higher anxiety scores.these differences were significant compared with the control group. conclusions: bullying is associated with psychopathology, which requires timely psychiatric attention.
Prevalencia de asma, rinitis y eczema en escolares de la ciudad de Cuernavaca, México
TATTO-CANO MARíA ISABEL,SANíN-AGUIRRE LUZ HELENA,GONZáLEZ VíCTOR,RUIZ-VELASCO SILVIA
Salud Pública de México , 1997,
Abstract: Objetivo. La medición del asma, la rinitis y el eczema ha sido motivo de controversia metodológica por la falta de uniformidad en los diagnósticos operacionales. Con el fin de probar la aplicabilidad de una metodología estandarizada para comparaciones en tiempo y espacio se determinó la prevalencia del asma y de otras enfermedades alérgicas en una muestra aleatoria de escolares (n= 6 238) de 6 a 8 a os y de 11 a 14 a os residentes de Cuernavaca, Morelos, México. Material y métodos. Se aplicó la metodología propuesta por el International Study of Asthma and Allergies in Childhood (ISAAC) para determinar la prevalencia y severidad del asma, la rinitis y el eczema. La información de prevalencia tanto actual como acumulada para dichos padecimientos se obtuvo a través de un cuestionario estandarizado contestado por los padres de los ni os. Resultados. La prevalencia acumulada de asma por diagnóstico médico y sibilancia fue de 5.8% (5.2-6.4) y 21.8% (20.7-22.9) respectivamente; la prevalencia de sibilancia en los últimos 12 meses fue de 8.9% en el grupo de 6 a 8 a os contra 6.6% en el de 11 a 14 a os, p< 0.001. La prevalencia de diagnóstico médico de rinitis fue de 4.9% (4.3-5.5). Con relación a los síntomas típicos de rinitis, en los últimos 12 meses la prevalencia fue de 9.6% (6 a 8 a os) y de 10.1% (11 a 14 a os). La prevalencia de eczema por diagnóstico médico fue de 4.1% (3.6-4.6). La prevalencia de síntomas de eczema en los últimos 12 meses fue de 10.1% (6 a 8 a os) y de 10.6% (11 a 14 a os). Los síntomas severos de asma fueron significativamente más prevalentes en el grupo de 6 a 8 a os y en los meses de oto o. Conclusiones. La prevalencia de asma tanto por diagnóstico médico como por síntomas resulta relativamente baja en relación con otros estudios realizados con la misma metodología. Se analizan las bondades del uso de una metodología estandarizada.
Structure and shaping processes within the extended atmospheres of AGB stars
M. Wittkowski,D. A. Boboltz,I. Karovicova,K. Ohnaka,A. E. Ruiz-Velasco,M. Scholz,A. Zijlstra
Physics , 2011,
Abstract: We present recent studies using the near-infrared instrument AMBER of the VLT Interferometer (VLTI) to investigate the structure and shaping processes within the extended atmosphere of AGB stars. Spectrally resolved near-infrared AMBER observations of the Mira variable S Ori have revealed wavelength-dependent apparent angular sizes. These data were successfully compared to dynamic model atmospheres, which predict wavelength-dependent radii because of geometrically extended molecular layers. Most recently, AMBER closure phase measurements of several AGB stars have also revealed wavelength-dependent deviations from 0/180 deg., indicating deviations from point symmetry. The variation of closure phase with wavelength indicates a complex non-spherical stratification of the extended atmosphere, and may reveal whether observed asymmetries are located near the photosphere or in the outer molecular layers. Concurrent observations of SiO masers located within the extended molecular layers provide us with additional information on the morphology, conditions, and kinematics of this shell. These observations promise to provide us with new important insights into the shaping processes at work during the AGB phase. With improved imaging capabilities at the VLTI, we expect to extend the successful story of imaging studies of planetary nebulae to the photosphere and extended outer atmosphere of AGB stars.
Prevalencia de asma, rinitis y eczema en escolares de la ciudad de Cuernavaca, México
TATTO-CANO,MARíA ISABEL; SANíN-AGUIRRE,LUZ HELENA; GONZáLEZ,VíCTOR; RUIZ-VELASCO,SILVIA; ROMIEU,ISABELLE;
Salud Pública de México , 1997, DOI: 10.1590/S0036-36341997000600002
Abstract: objective. the measurement of asthma, rhinitis and eczema have been subject of controversy due to lack of a standardized methodology. to test the applicability of a standardized methodology for comparisons of time and space we determined the prevalence of asthma and other allergic diseases in a random sample of schoolchildren (n= 6 238) from 6 to 8 and 11 to 14 years of age living in cuernavaca, morelos, mexico. material and methods. the methodology proposed by the international study of asthma and allergies in childhood (isaac) to determine prevalence and severity of asthma, rhinitis and eczema was applied. current and accumulated information on prevalence was obtained by means of a standardized questionnaire answered by the children?s parents. results. the accumulated prevalence of asthma by medical diagnosis and wheezing was 5.8% (5.2-6.4) and 21.8% (20.7-22.9) respectively; prevalence of wheezing in the last 12 months was 8.9% in the group of 6 to 8 years against 6.6% in the 11 to 14 year old group p<0.001. prevalence of the medical diagnosis of rhinitis was 4.9% (4.3-5.5). regarding the typical symptoms of rhinitis, in the last 12 months prevalence was 9.6% (6-8 years) and 10.1% (11-14 years). prevalence of eczema by medical diagnosis was 4.1% (3.6-4.6). prevalence of eczema symptoms in the last 12 months was 10.1% (6-8 years) and 10.6% (11-14 years). prevalence of severe asthma symptoms was significantly higher in the 6 to 8 year olds and in the autumn. conclusions. prevalence of asthma by medical diagnosis and by symptoms is relatively low with respect to other studies performed with the same methodology. the benefits of using a standardized methodology were analyzed.
Susceptibilidad al consumo de tabaco en estudiantes no fumadores de 10 ciudades mexicanas
Arillo-Santillán,Edna; Thrasher,James; Rodríguez-Bola?os,Rosibel; Chávez-Ayala,Rubén; Ruiz-Velasco,Silvia; Lazcano-Ponce,Eduardo;
Salud Pública de México , 2007, DOI: 10.1590/S0036-36342007000800007
Abstract: objective: to identify the cognitive susceptibility to smoking and associated factors in students between 12 and 15 years of age. material and methods: the baseline measurement of a self-administered survey conducted between 2005 and 2006 of 12 293 non-smoking high school students was analyzed. susceptibility was considered to be a student who would accept a cigarette from his or her best friend and would smoke the following year. multilevel logistic regression models were obtained. results: the prevalence of susceptibility was 30%. associated factors were low self-esteem (rm = 1.2, ic95% 1.0-1.5), seeking new sensations (rm = 1.6, ic95% 1.3-2.0) and a favorable attitude towards smoking (rm = 2.6, ic95% 2.2-3.2), as well as the social permissibility reflected in the norms at home (rm = 2.2, ic95% 1.7-2.8). the interaction between permissibility of smoking at home and tobacco consumption by parents existed only for females (rm = 2.1, ic95% 1.1-3.8). conclusions: prevention should promote the sensitization of the family?s parents and teachers as anti-smoking models and encourage tobacco-free homes.
The extended atmospheres of Mira variables probed by VLTI, VLBA, and APEX
M. Wittkowski,D. A. Boboltz,C. de Breuck,M. Gray,E. Humphreys,M. Ireland,I. Karovicova,K. Ohnaka,A. E. Ruiz-Velasco,M. Scholz,P. Whitelock,A. Zijlstra
Physics , 2011,
Abstract: We present an overview on our project to study the extended atmospheres and dust formation zones of Mira stars using coordinated observations with the Very Large Telescope Interferometer (VLTI), the Very Long Baseline Array (VLBA), and the Atacama Pathfinder Experiment (APEX). The data are interpreted using an approach of combining recent dynamic model atmospheres with a radiative transfer model of the dust shell, and combining the resulting model structure with a maser propagation model.
Observation of Small-scale Anisotropy in the Arrival Direction Distribution of TeV Cosmic Rays with HAWC
A. U. Abeysekara,R. Alfaro,C. Alvarez,J. D. álvarez,R. Arceo,J. C. Arteaga-Velázquez,H. A. Ayala Solares,A. S. Barber,B. M. Baughman,N. Bautista-Elivar,E. Belmont,S. Y. BenZvi,D. Berley,M. Bonilla Rosales,J. Braun,K. S. Caballero-Mora,A. Carrami?ana,M. Castillo,U. Cotti,J. Cotzomi,E. de la Fuente,C. De León,T. DeYoung,R. Diaz Hernandez,J. C. Díaz-Vélez,B. L. Dingus,M. A. DuVernois,R. W. Ellsworth,D. W. Fiorino,N. Fraija,A. Galindo,F. Garfias,M. M. González,J. A. Goodman,M. Gussert,Z. Hampel-Arias,J. P. Harding,P. Hüntemeyer,C. M. Hui,A. Imran,A. Iriarte,P. Karn,D. Kieda,G. J. Kunde,A. Lara,R. J. Lauer,W. H. Lee,D. Lennarz,H. León Vargas,J. T. Linnemann,M. Longo,R. Luna-García,K. Malone,A. Marinelli,S. S. Marinelli,H. Martinez,O. Martinez,J. Martínez-Castro,J. A. J. Matthews,J. McEnery,E. Mendoza Torres,P. Miranda-Romagnoli,E. Moreno,M. Mostafá,L. Nellen,M. Newbold,R. Noriega-Papaqui,T. Oceguera-Becerra,B. Patricelli,R. Pelayo,E. G. Pérez-Pérez,J. Pretz,C. Rivière,D. Rosa-González,E. Ruiz-Velasco,J. Ryan,H. Salazar,F. Salesa Greus,A. Sandoval,M. Schneider,G. Sinnis,A. J. Smith,K. Sparks Woodle,R. W. Springer,I. Taboada,P. A. Toale,K. Tollefson,I. Torres,T. N. Ukwatta,L. Villase?or,T. Weisgarber,S. Westerhoff,I. G. Wisher,J. Wood,G. B. Yodh,P. W. Younk,D. Zaborov,A. Zepeda,H. Zhou
Physics , 2014, DOI: 10.1088/0004-637X/796/2/108
Abstract: The High-Altitude Water Cherenkov (HAWC) Observatory is sensitive to gamma rays and charged cosmic rays at TeV energies. The detector is still under construction, but data acquisition with the partially deployed detector started in 2013. An analysis of the cosmic-ray arrival direction distribution based on $4.9\times 10^{10}$ events recorded between June 2013 and February 2014 shows anisotropy at the $10^{-4}$ level on angular scales of about $10^\circ$. The HAWC cosmic-ray sky map exhibits three regions of significantly enhanced cosmic-ray flux; two of these regions were first reported by the Milagro experiment. A third region coincides with an excess recently reported by the ARGO-YBJ experiment. An angular power spectrum analysis of the sky shows that all terms up to $\ell=15$ contribute significantly to the excesses.
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