A model of the radiation emitted by a source in the vicinity of a Kerr black hole

“The present thesis is the study of: the physics that characterizes the Bessel beams, the behavior of the reected radiation by a parabolic mirror considering inclined incident light rays and Kirchho's diraction theory applied to the phenomenon of reection of light ray by a parabolic mirror, in particular that of the LMT/GTM antenna. It is shown that adiractional beams which are invariant under translations along the axis of propagation, are characterized by a family of wavefronts and a caustic, and it is found that the caustic qualitatively coincides with the absolute maximum of the intensity pattern. Then, expressions for: the incident light rays and wavefronts, the reected light rays, the reected wavefronts, the caustic and the ronchigram have been ob- tained; those general results are applied to the parameters of the antenna of the LMT/GTM and it is shown that the caustic has a singularity of the hyperbolic umbilic type, which is locally stable under small perturbations of the optical system. The results presented could be associated to the radiation of a static source, in the geometrical optics limit. Finally, an expression for the intensity pattern associated with the reection of a Bessel beam of order m by the LMT/GTM antenna has been determined; the preliminary results are presented”

The effects of a non-contributory pension program on labor force participation: The case of 70 y Más in Mexico

We estimate the effect of 70 y Más, an age-conditioned transfer program for individuals age 70 and older in rural Mexico, on the labor force participation of beneficiaries and of younger individuals who live with them. Using data from the 2010 Mexican Census, we exploit the age and locality population thresholds to identify the effects of the program. We find that the program reduces the labor force participation of elderly men, particularly of those who live alone and who are relatively poor, but has a much weaker effect on that of elderly women. The program has no statistically significant effect on the labor force participation of either prime-age men or women who live with potential beneficiaries, and it has a negative and significant effect on the labor force participation of boys age 12 to 17, particularly those in the lowest wealth quintiles, but not on that of same-age girls. These results suggest that the program affects mostly the labor supply of the intended beneficiaries, and that of marginal workers, like adolescent boys

“CAPACITACIÓN EN EL MANEJO HIGIÉNICO DE ALIMENTOS AL PERSONAL DE UN SERVICIO DE ALIMENTACIÓN COLECTIVO A TRAVÉS DEL DISTINTIVO H.”

Es de suma importancia capacitar al personal que manipula alimentos, para que de esta forma tengan las bases y fundamentos que señalan las normas que rigen nuestro país para la manipulación higiénica de los alimentos. Las enfermedades transmitidas por los alimentos son uno de los problemas de salud pública que se presentan con mayor frecuencia en la vida cotidiana de la población. Muchas de las enfermedades, tienen su origen en el acto mismo de manipular los alimentos en cualquiera de sus etapas, desde la producción hasta su consumo. El impacto en la salud pública, la contaminación de los alimentos tiene efectos económicos, sobre los establecimientos dedicados a su preparación y venta, así como de quienes contratan a empresas dedicadas a este ramo para su servicio, Si se presentan estas enfermedades en un grupo cerrado de la población, las empresas que brinden sus servicios de alimentación pierden la confiabilidad por parte del cliente. Las medidas para evitar la contaminación de los alimentos son sencillas y pueden ser aplicadas por quien quiera que los manipule, aprendiendo las reglas para su manejo higiénico, empezando por cumplir con los conocimientos teóricos que avalen dichas acciones prácticas. De ello surge la necesidad de unir esfuerzos con el manipulador, otorgando los instrumentos necesarios teórico-prácticos que permitan un mejor desempeño de sus funciones, proporcionando un servicio más profesional y sobre todo de calidad lo que contribuirá a que el rubro de alimentación industrial se sume mas a la lista de servicios de alimentación colectiva que cuenten con el Distintivo H lo que permitirá una carta de presentación probatoria por parte de los comensales, tanto por la variedad gastronómica como por la seguridad de la manipulación higiénica de los alimentos. El conocimiento sobre los alimentos y su manipulación, tiene mayor importancia a inicios del este milenio y ha hecho que sea un área cada vez mas explorada. Diversas instituciones preocupadas por el impacto social derivado de las infecciones provenientes de la mala manipulación higiénica de los alimentos han desarrollado lineamientos cada vez más exigentes en los que los establecimientos fijos que manipulan alimentos deben cumplir para de esta forma garantizar la salud, seguridad y en el caso del sector industrial la productividad. Por lo antes expuesto se plantea la siguiente pregunta de investigación ¿Cuál es el nivel de conocimientos de los manejadores de alimentos previa y post capacitación del distintivo H en el Comedor de la Empresa Manufacturera de Autopartes Eléctricas, ubicada en Toluca Estado de México

Utilización de albedo deshidratado de citrus para clarificación de efluentes

De la industrialización del limón se obtienen muchos subproductos como el jugo concentrado, aceite esencial, cáscara deshidratada y cáscara húmeda. En este trabajo se utilizó el albedo deshidratado de limón para clarificar efluentes, aprovechando la capacidad de absorción de la pectina allí presente (Neme,et al 2008). Este residuo de la industria del limón se exporta como pienso para animales. Para su obtención se extrajo el jugo de limón dejando libre el albedo. Posteriormente se lo secó en una estufa a una temperatura de 60 ºC durante 24 hs para luego triturarlo, obteniéndose diferentes granulometrías: 54 % 2 mm, 36%1 mm y 10% 0,5 mm. El polvo de albedo de distintas granulometrías se colocó en 3 cubas de vidrio de 20 litros. Para evaluar su poder clarificante, se midió la densidad óptica (DO) a 350 nm de longitud de onda (λ) a las 24, 48 y 72 hs luego de poner en contacto con el efluentes; observándose un descenso abrupto de la DO a las 24 hs y permaneciendo casi constante a las 48 y 72 hs de tratado el efluente. El mayor poder clarificante se observó en la granulometría de 0,5 mm; efecto causado por parámetros relacionados con el tamaño y forma de las partículas, como por ejemplo la estabilidad, sabor, color, absorción, velocidad de disolución, uniformidad de contenido de la forma. La reactividad de estos polvos viene dada por la superficie específica, a menor tamaño de partícula mayor superficie, mayor velocidad de disolución, mayor absorción; por lo tanto, aumenta la reactividad del polvo y posee superior poder clarificante que se observa a tan solo transcurridos 25 minutos. Las otras granulometrías también resultaron aclarantes de los efluentes pero después de transcurridas 24 hs, ninguna de las tres cubas presentó mal olor. Sin embargo, se observó crecimiento de hongos pasadas las 72 hs en las cubas conteniendo partículas de 1 y 2 mm, no así en las de granulometría de 0,5 mm.Many by-products are obtained from the industrialization of lemon, such as concentrated juice, essential oil, dehydrated peel and wet peel. In this work, dehydrated lemon albedo was used to clarify effluents taking advantage of the absorption capacity of pectin present in this lemon fraction. This by-product of the lemon industry is exported as animal feed. To obtain the dehydrated lemon peels, juice was extracted from fresh lemons leaving the albedo free. Subsequently, the peels were dried in a stove at 60 °C for 24 h and then grinded obtaining different granulometries: 54% 2 mm, 36% 1 mm and 10% 0.5 mm. The albedo powder of different granulometries was placed in 3 glass buckets of 20 liters. To evaluate its clarifying power, the optical density (OD) at 350 nm wavelength (λ) was measured 24, 48 and 72 h after being put in contact with the effluents, observing an abrupt decrease of DO at 24 hours and remaining almost constant at 48 and 72 h after treatment of the effluent. The greater clarifying power was observed in the granulometry of 0.5 mm; effect caused by parameters related to the size and shape of the particles, such as stability, taste, color, absorption, dissolution rate, uniformity of content of the form. The reactivity of these powders is given by the specific surface area, the smaller the particle size, the higher the surface area, the higher the dissolution rate, the higher the absorption. Therefore, it increases the reactivity of the powder and has superior clarifying power that is observed after only 25 minutes. The other granulometries also clarified the effluents but after 24 hours. Even though none of the three buckets had bad smell, fungi growth was observed after 72 h in the buckets containing particles of 1 and 2 mm, but not in that with a particle size of 0.5 mm.Fil: Juárez, Clarisa.Fil: González, Karina.Fil: María, Federico

Variação diurna do cortisol e sua relação com o estresse: otimismo e estratégias de enfrentamento em mulheres com câncer de mama

O ritmo diurno do cortisol vem sendo visto alterado nos pacientes com câncer. Fatores como o avanço da doença e os níveis de estresse estão sendo considerados para explicar essa condição; contudo, os resultados não são claros. O objetivo deste estudo foi avaliar e determinar se existem diferenças nos níveis de cortisol em mulheres com câncer de mama de diferentes estágios, bem como analisar estratégias de enfrentamento. Foram coletadas amostras de cortisol salival durante dois dias e aplicados questionários psicológicos de estresse percebido, otimismo disposicional e estratégias de enfrentamento a 17 mulheres com câncer de mama em estágio I, II e III. Os resultados mostram que as pacientes com esse câncer nos três estágios apresentam um ritmo diurno de cortisol normal e não se diferenciam significativamente na variável de otimismo. A respeito das variáveis psicológicas, só diferem na variável de otimismo. As estratégias de enfrentamento -espírito de luta e evitação cognitiva- são as variáveis que têm mais influência nos níveis de cortisol e explicam 55% da variação. Discutem-se as implicações desses resultados.El ritmo diurno del cortisol se ha visto alterado en los pacientes con cáncer. Factores como el avance de la enfermedad y los niveles de estrés se han considerado para explicar esta condición; sin embargo, los resultados no son claros. El objetivo de este estudio fue evaluar y determinar si existen diferencias en los niveles de cortisol en mujeres con cáncer de mama en diferentes estadios, y analizar la relación entre los niveles de cortisol y el estrés, el optimismo y las estrategias de afrontamiento. Se recolectaron muestras de cortisol salival durante dos días, y se aplicaron cuestionarios psicológicos de estrés percibido (PSS), optimismo disposicional (LOT-R) y estrategias de afrontamiento (MAC) a 17 mujeres con cáncer de mama en estadio I, II y III. Los resultados muestran que las pacientes con cáncer de mama en los tres estadios presentan un ritmo diurno de cortisol normal y no difieren significativamente en los niveles de cortisol. Respecto a las variables psicológicas, solo difieren en la variable de optimismo. Las estrategias de afrontamiento espíritu de lucha y evitación cognitiva son las variables que tienen más influencia en los niveles de cortisol, y explican un 55% de la varianza. Se discuten las implicaciones de estos resultados.Diurnal cortisol rhythm has been altered in patients with cancer. Factors such as disease progression and stress levels are regarded as possible causes to explain this condition, however results are not clear. The aim of this study was to assess and determine whether there are differences in cortisol levels in women with breast cancer in different stages and analyze the relationship between cortisol levels and stress, optimism and coping strategies. Salivary cortisol samples were collected for two days and psychological questionnaires of perceived stress (PSS), dispositional optimism (LOT-R) and coping strategies (MAC) were administered to 17 breast cancer women in stage I, II and III of the disease. The results show that patients with breast cancer in the three stages have a normal diurnal cortisol rhythm and do not differ significantly in cortisol levels. Regarding the psychological variables, they differ only in optimism. Coping strategies such as fighting spirit and cognitive avoidance are the variables that have more influence on cortisol levels, explaining 55% of variance. The implications of these results are discussed

Quark mixings as a test of a new symmetry of quark Yukawa couplings

Based on the hierarchy exhibited by quarks masses at low energies, we assume that Yukawa couplings of up and down quarks are related by $Y_u\propto Y_d^2$ at grand unification scales. This ansatz gives rise to a symmetrical CKM matrix at the grand unification (GU) scale. Using three specific models as illustrative examples for the evolution down to low energies, we obtain the entries and asymmetries of the CKM matrix which are in very good agreement with their measured values. This indicates that the small asymmetry of the CKM matrix at low energies may be the effect of the renormalization group evolution only.Comment: LaTeX file, 10 pages including 1 tabl

The effect of a transfer program for the elderly in Mexico City on co-residing children's school enrollment

This paper studies whether the increase in government transfers, induced by an old-age pension program for individuals age 70 and older in Mexico, affects co-residing children's school enrollment, using a regression discontinuity analysis. Results suggest that while household composition and other household-level characteristics do not change significantly at the cutoff age for program eligibility, co-residing children's school enrollment increases significantly. This suggests that public resources for older adults might generate benefits for other age groups. An additional finding is that the increase in school enrollment takes places mostly at the program eligibility cutoff and not before. Given that the program transfer is known and potentially anticipated by individuals who are only a few years away from being eligible, this suggests that households might have credit constraints

Precise bounds on the Higgs boson mass

We study the renormalization group evolution of the Higgs quartic coupling $\lambda_{H}$ and the Higgs mass $m_{H}$ in the Standard Model. The one loop equation for $\lambda_{H}$ is non linear and it is of the Riccati type which we numerically and analytically solve in the energy range $[m_{t},E_{GU}]$ where $m_{t}$ is the mass of the top quark and $E_{GU}=10^{14}$ GeV. We find that depending on the value of $\lambda_{H}(m_{t})$ the solution for $\lambda_{H}(E)$ may have singularities or zeros and become negative in the former energy range so the ultra violet cut off of the standard model should be below the energy where the zero or singularity of $\lambda_{H}$ occurs. We find that for $0.369\leq\lambda_{H}(m_{t})\leq0.613$ the Standard Model is valid in the whole range $[m_{t},E_{GU}]$. We consider two cases of the Higgs mass relation to the parameters of the standard model: (a) the effective potential method and (b) the tree level mass relations. The limits for $\lambda_{H}(m_{t})$ correspond to the following Higgs mass relation $150\leq m_{H}\lessapprox 193$ GeV. We also plot the dependence of the ultra violet cut off on the value of the Higgs mass. We analyze the evolution of the vacuum expectation value of the Higgs field and show that it depends on the value of the Higgs mass. The pattern of the energy behavior of the VEV is different for the cases (a) and (b). The behavior of $\lambda_{H}(E)$, $m_{H}(E)$ and $v(E)$ indicates the existence of a phase transition in the standard model. For the effective potential this phase transition occurs at the mass range $m_{H}\approx 180$ GeV and for the tree level mass relations at $m_{H}\approx 168$ GeV.Comment: 14 pages, 7 figures. Expanded the discussion of the Higgs mass relation between the parameters of the Standard Model. Included the method of the Higgs effective potentia

Factores Pronósticos De La Saturación De Oxígeno En Pacientes Con COVID-19 Atendidos En Cuidados Intensivos En Un Hospital De México

Introducción. El COVID-19 es una enfermedad que ha causado problemas nacionales e internacionales de salud pública, afectando a las áreas sanitaria, económica y social. Objetivo. Analizar los factores pronósticos de la saturación de oxígeno según la gasometría arterial en pacientes con COVID-19 atendidos en la unidad de cuidados intensivos. Metodología. Estudio transversal llevado a cabo en el Hospital General de Querétaro, México en el área de terapia intensiva con pacientes positivos a COVID-19 del periodo del 4 de mayo del 2020 al 24 de mayo del 2021, considerando un total de 165 pacientes; el tipo de muestro fue no probabilistico según criterio. Resultados. Son capaces de predecir la saturación de oxígeno la presión arterial de oxigeno entre la fracción inspirada de oxígeno, la glucosa capilar y las plaquetas. Conclusiones. Los datos analizados sugieren la posibilidad de considerar su aplicación en áreas hospitalarias para prevenir la gravedad en pacientes con COVID-19; es necesario continuar documentando más resultados. Introduction. COVID-19 is a disease that has caused national and international public health problems, affecting health, economic and social areas. Objective. To analyze the prognostic factors of oxygen saturation according to arterial blood gases in patients with COVID-19 attended in the intensive care unit. Methodology.  Cross-sectional study carried out at the General Hospital of Queretaro, Mexico in the intensive care area with COVID-19 positive patients from May 4, 2020 to May 24, 2021, considering a total of 165 patients; the type of sampling was non-probabilistic according to criteria. Results. Are able to predict oxygen saturation arterial oxygen pressure between inspired oxygen fraction, capillary glucose and platelets. Conclusions. The data analyzed suggest the possibility of considering its application in hospital areas to prevent severity in patients with COVID-19; it is necessary to continue documenting more results