Probing Yukawian gravitational potential by numerical simulations. I. Changing N-body codes

In the weak field limit general relativity reduces, as is well known, to the Newtonian gravitation. Alternative theories of gravity, however, do not necessarily reduce to Newtonian gravitation; some of them, for example, reduce to Yukawa-like potentials instead of the Newtonian potential. Since the Newtonian gravitation is largely used to model with success the structures of the universe, such as for example galaxies and clusters of galaxies, a way to probe and constrain alternative theories, in the weak field limit, is to apply them to model the structures of the universe. In the present study, we consider how to probe Yukawa-like potentials using N-body numerical simulations.Comment: 17 pages, 11 figures. To appear in General Relativity and Gravitatio

Dinámica del agua y fitoquímicos durante el secado de rodajas de chile habanero rojo (Capsicum chinense)

Habanero pepper (Capsicum chinense) is a source of phytochemicals or bioactive compounds that have shown benefits in human health. For phytochemicals extraction process, a prior drying is required. Therefore, the aim of this study was to evaluate the effect of drying temperature (30, 50 and 70 degrees C) on total capsaicinoids and total carotenoids, and the coefficients of water diffusivity during drying of sliced red habanero pepper. The results show that the bioactive compounds, present a major stability at high temperature (70 degrees C), the effective diffusivity increased with drying temperature and the activation energy of the process was calculated to 39.575 kJ mol(-1) K-1. Several theoretical aspects of average water diffusivity are discussed

Evaluación de 11 híbridos de caña de azúcar (Saccharum spp.) en la región central de Veracruz, México

Objective: The objective of this study was to select new hybrids of sugarcane (Saccharum spp.) adapted to the area supplyof the Central Progreso sugar mill located in Paso del Macho, Veracruz, Mexico.Design/methodology/approach: A group of 11 new hybrids were established in the agroindustrial phase, in ordercompare their adaptation and field and industrial performance using the commercial hybrids Mex 69-290 and CP 72-2086 as controls.Results: The results obtained indicated that during the plant cycle and under local soil conditions, the ColMex 98-100hybrid showed the highest field yield (144.34 t ha?1) and the higher value for the theoretical sugar per hectare (20.26 t),even though it had the lowest values of percentage of sucrose (Pol) (14.64). Regarding the percentage of sucrose, thehighest records were obtained by the ColMex 95-27 (16.97), ColMex 05-627 (16.29), and ColMex 05-47 (16.27) hybrids,with values above the commercial control CP 72-2086 (16.11).Limitations on study/implications: An important limitation for the investigation was the abundance of stones in the topsoil.Findings/conclusions: It can be concluded that after analyzing the agricultural and industrial performance that, the besthybrids were: ColMex 98-100, ColMex 05-47, ColMex 05-627, and CP 71-1038, surpassing the commercial controlsObjetivo: El objetivo de este estudio fue seleccionar nuevos híbridos de caña de azúcar (Saccharum spp.) adaptados al área de abasto del Ingenio Central Progreso localizado en Paso del Macho, Veracruz,México.Diseño/metodología/aproximación: Se estableció en fase agroindustrial un grupo de 11 nuevos híbridos, los cuales fueron comparados por su adaptación y rendimiento de campo e industrial con los híbridos comerciales Mex 69-290 y CP 72-2086.Resultados: Los resultados obtenidos indicaron que durante el ciclo planta y bajo las condiciones edafoclimáticas del lugar, el hibrido ColMex 98-100 resultó ser el mejor en rendimiento de campo (144.34 t ha?1) y mayor valor en azúcar teórica por hectárea (20.26 t), aun teniendo los valores más bajos en porcentaje de sacarosa (Pol) (14.64%). En cuanto a la variable % de sacarosa, los mayores porcentajes lo obtuvieron los híbridos ColMex 95-27 (16.97%), ColMex 05-627 (16.29%) y ColMex 05- 47 (16.27%), con valores por encima del testigo comercial CP 72-2086 (16.11%).Limitaciones del estudio/implicaciones: Una limitación importante para la investigación fue la abundancia de piedras sobre la capa arable del suelo.Hallazgos/conclusiones: Se puede concluir que después de analizar el comportamiento agrícola e industrial, los mejores híbridos fueron: ColMex 98-100, ColMex 05-47, ColMex 05-627 y CP 71-1038,superando a los testigos comerciales

Comparación de la percepción social en playas recreativas arenosas de dos bahías localizadas en el Pacífico Mexicano

En el presente trabajo se desarrollaron dos formatos de encuesta, para incorporar la percepción de los usuarios a la evaluación de la calidad de las playas (Cervantes, 2006 y Silva-Iñiguez, 2006); ambos basados en un modelo cuantitativo para revelar la percepción social de las playas localizadas en la bahía de Santiago, Manzanillo, Col (MZO) y en Acapulco, Gro (ACA). Se aplicaron un total de 790 encuestas (ACA: 390 y MZO: 400), que permitieron conocer el perfil de los usuarios, sus hábitos de recreación y sus opiniones sobre las condiciones biofísicas y de infraestructura de cada playa. En ambas playas la mayoría prefirieron asistir acompañados por sus familias; las principales actividades recreativas fueron nadar, descansar, comer y beber. En general las demandas en ambos sitios coincidieron con incrementar el número de botes de basura, la frecuencia en el servicio de recolección y limpieza, baños y regaderas. Las razones por la que los usuarios seleccionaron la playa a visitar fueron la seguridad y vigilancia, así como las características biofísicas de la misma. La incorporación de esta información a modelos y/o esquemas de evaluación y gestión de playa (a través de índices ambientales) permitió realizar la valoración integral de la playa.In this paper it was developed two survey formats, to include the perception of users on the assessment of the quality of the beaches (Cervantes, 2006 and Silva-Iñiguez, 2006), both based on a quantitative model to reveal the social perception of the beaches on Santiago Bay, Manzanillo, Col (MZO) and Acapulco, Guerrero (ACA). We did a total of 790 surveys (ACA: 390 and MZO: 400), which allowed the user profile, recreation habits and their views on the biophysical and infrastructure of each beach. In both beaches, most people, attended with their families, the main recreational activities were swimming, resting, eating and drinking. In general the demands on both sites agreed to increase the number of waste baskets, the frequency of collection service and cleaning bathrooms and showers. The reasons why the users selected to visit the beach were the safety and security, as well as the biophysical characteristics of the same. Incorporating this information to models and / or evaluation schemes and beach management (through environmental ratings) allowed the comprehensive assessment of the beach

El Desarrollo de Competencias Docentes Para la Inclusión. Narrativas de Docentes en Formación

La indagación se construye a partir de la recuperación de experiencias narradas por estudiantes que cursaron la Licenciatura en Educación Primaria en la Escuela Normal Rural Mactumactzá (ENRM), derivado del Programa Necesidades Educativas Especiales correspondiente al Plan de Estudios de la Licenciatura en Educación Primaria 1997 (LEP’97)

Potential-density pairs for axisymmetric galaxies: the influence of scalar fields

We present a formulation for potential-density pairs to describe axisymmetric galaxies in the Newtonian limit of scalar-tensor theories of gravity. The scalar field is described by a modified Helmholtz equation with a source that is coupled to the standard Poisson equation of Newtonian gravity. The net gravitational force is given by two contributions: the standard Newtonian potential plus a term stemming from massive scalar fields. General solutions have been found for axisymmetric systems and the multipole expansion of the Yukawa potential is given. In particular, we have computed potential-density pairs of galactic disks for an exponential profile and their rotation curves.Comment: 8 pages, no figures, corrected version to the one that will appear in Gen. Relativ. Gravit., where a small typo in eq. (13) is presen

Better adherence to the mediterranean diet could mitigate the adverse consequences of obesity on cardiovascular disease: The SUN prospective cohort

Strong observational evidence supports the association between obesity and cardiovascular events. In elderly high-risk subjects, the Mediterranean diet (MedDiet) was reported to counteract the adverse cardiovascular effects of adiposity. Whether this same attenuation is also present in younger subjects is not known. We prospectively examined the association between obesity and cardiovascular clinical events (myocardial infarction, stroke or cardiovascular death) after 10.9 years follow-up in 19,065 middle-aged men and women (average age 38 year) according to their adherence to the MedDiet (<6 points or ¥6 points in the Trichopoulou’s Mediterranean Diet Score). We observed 152 incident cases of cardiovascular disease (CVD). An increased risk of CVD across categories of body mass index (BMI) was apparent if adherence to the MedDiet was low, with multivariable-adjusted hazard ratios (HRs): 1.44 (95% confidence interval: 0.93–2.25) for ¥25 – <30 kg/m2 of BMI and 2.00 (1.04–3.83) for ¥30 kg/m2 of BMI, compared to a BMI < 25 kg/m2. In contrast, these estimates were 0.77 (0.35–1.67) and 1.15 (0.39–3.43) with good adherence to MedDiet. Better adherence to the MedDiet was associated with reduced CVD events (p for trend = 0.029). Our results suggest that the MedDiet could mitigate the harmful cardiovascular effect of overweight/obesity

Exploratory outcome analyses according to stage and/or residual disease in the ICON7 trial of carboplatin and paclitaxel with or without bevacizumab for newly diagnosed ovarian cancer

Objective: In the randomized phase 3 ICON7 trial (ISRCTN91273375), adding bevacizumab to chemotherapy for newly diagnosed ovarian cancer significantly improved progression-free survival (PFS; primary endpoint) but not overall survival (OS; secondary endpoint) in the intent-to-treat (ITT) population. We explored treatment effect according to stage and extent of residual disease. Methods: Patients with stage IIB-IV or high-risk (grade 3/clear-cell) stage I-IIA ovarian cancer were randomized to receive six cycles of carboplatin and paclitaxel either alone or with bevacizumab 7.5 mg/kg every 3 weeks followed by single-agent bevacizumab for 12 further cycles (total duration 12 months). Post hoc exploratory analyses of subgroups defined by stage and extent of residual disease at diagnosis within the stage IIIB-IV population (European indication) was performed. Results: The PFS benefit from bevacizumab was seen consistently in all subgroups explored. The PFS hazard ratio was 0.77 (95% confidence interval [CI], 0.59-0.99) in 411 patients with stage IIIB-IV ovarian cancer with no visible residuum and 0.81 (95% CI, 0.69-0.95) in 749 patients with stage IIIB-IV disease and visible residuum. As in the ITT population, no OS difference was detected in any subgroup except the previously described 'high-risk' subgroup. Safety results in analyzed subgroups were consistent with the overall population. Conclusions: Adding bevacizumab to front-line chemotherapy improves PFS irrespective of stage/residual disease. In patients with stage III with >1 cm residuum, stage IV or inoperable disease, this translates into an OS benefit. No OS benefit or detriment was seen in other subgroups explored