Effect of dried leaves of Leucaena leucocephala on rumen fermentation, rumen microbial population, and enteric methane production in crossbred heifers

The effects of dietary inclusion of dried Leucaena leucocephala leaves (DLL) on nutrient digestibility, fermentation parameters, microbial rumen population, and production of enteric methane (CH4) in crossbred heifers were evaluated. Four heifers were used in a 4 × 4 Latin square design consisting of four periods and four levels of inclusion of DLL: 0%, 12%, 24%, and 36% of dry matter (DM) intake. Results showed that DM intake (DMI), organic matter intake, and gross energy intake (GEI) were similar (p > 0.05) among treatments. Apparent digestibility of organic matter, neutral detergent fiber, and energy decreased with increasing levels of DLL in the ration (p 0.05) rumen pH and total volatile fatty acids. Rumen microbial community was not affected (p > 0.05) by treatment. There was a linear reduction (p < 0.05) in CH4 emissions as the levels of DLL in the ration were increased. Results of this study suggest that an inclusion of 12% DM of ration as DLL enhances digestible CP and reduces daily production of enteric CH4 without adversely affecting DMI, rumen microbial population, and fermentation parameters

Segundo ejercicio resuelto de las pruebas selectivas para el ingreso en el Cuerpo Superior de Inspectores de Seguros del Estado

Caso 1. Contabilidad financiera superior. Formulación de la cuenta de pérdidas y ganancias siguiendo los criterios del Plan General de Contabilidad. Caso 2. Contabilidad de sociedades. Derechos de suscripción, ampliación de capital por compensación de deudas, combinaciones de negocios, operaciones con acciones propias y determinación del beneficio distribuible. Caso 3. Análisis económico, financiero y patrimonial de estados financieros. Margen bruto sobre ventas, margen de explotación sobre ventas, rotación de existencias, rotación de deudores comerciales, rotación de cuentas a pagar, análisis del apalancamiento financiero, coeficiente beta y análisis del punto muerto. Caso 4. Consolidación de estados financieros. Balance de situación consolidado, ocios externos y fondo de comercio en primera consolidación, variaciones de patrimonio neto en consolidaciones posteriores e incremento del porcentaje de participación. Cuenta de pérdidas y ganancias consolidada, existencia de plusvalía amortizable en la fecha de toma de control y ajustes por operaciones internas de venta de inmovilizado y existencias

Detection of Mycobacterium avium subsp. paratuberculosis by a Direct In Situ PCR Method

In situ detection of Mycobacterium avium subsp. paratuberculosis is useful for diagnosis and research of paratuberculosis. The aim of this paper was to detect this agent in formalin-fixed, paraffin-embedded tissue samples by a direct in situ PCR. The technique was performed on ileum or ileocaecal lymph node samples from 8 naturally infected cattle and 1 healthy calf, by using p89 and p92 primers for amplification of IS900 sequence. Moderate positive signal was detected in all positive samples and not in negative control, but tissues resulted were affected in many cases due to the enzymatic treatment and the high temperature exposition. Although the technique was useful for Map detection, the signal was lower than immunohistochemistry probably because of the fixation process. In one case, signal was higher, which might be due to the detection of spheroplasts. Thus, the described method should be recommended when others resulted negative or for spheroplasts detection

El uso de la tabla aritmética para el aprendizaje reflexivo de la resolución de las cuatro operaciones básicas de la aritmética, con estudiantes de 4º grado de primaria

Enseñar matemáticas en Educación Básica (Primaria) no solo es enseñar conceptos y algoritmos de forma expositiva, sino que se deben diseñar situaciones didácticas con material manipulativo que permita operar con ellos y resolver problemas que supongan un desafío intelectual, a fin de desarrollar la capacidad de razonamiento y alcanzar la abstracción matemática de los estudiantes de esta etapa. En este sentido, el Plan de Estudios 2011 de Educación Básica de México ha tratado de implementar nuevas estrategias, a fin de ir rompiendo con los esquemas tradicionalistas, buscando que los estudiantes sean responsables de construir nuevos conocimientos a partir de sus saberes previos, de comunicar, analizar e interpretar procedimientos de resolución y encontrar diferentes formas de resolver los problemas. Bajo estas consideraciones, se implementó una secuencia didáctica usando la tabla aritmética creada por Jorge Vaca (2002) en un grupo de estudiantes de 4º grado de primaria, y en otro grupo del mismo grado, una secuencia temática sin el uso de la tabla. El objetivo de este estudio fue comparar en ambos grupos, mediante un pre-test y un pos-test, las medias de los criterios evaluados, a fin de determinar cuál es el efecto de la aplicación de la tabla aritmética en el aprendizaje reflexivo de la resolución de las cuatro operaciones de la aritmética elemental: suma, resta, multiplicación y división. Los resultados de esta comparación mostraron, con diferencias significativas, que al trabajar con la tabla aritmética los estudiantes fueron más críticos y reflexivos, pues analizaron e interpretaron los problemas para poder seleccionar qué tipo de operación o combinación de operaciones desarrollar que permitieran resolverlos

Cytotoxicity induced by carbon nanotubes in experimental malignant glioma

"Despite multiple advances in the diagnosis of brain tumors, there is no effective treatment for glioblastoma. Multiwalled carbon nanotubes (MWCNTs), which were previously used as a diagnostic and drug delivery tool, have now been explored as a possible therapy against neoplasms. However, although the toxicity profile of nanotubes is dependent on the physicochemical characteristics of specific particles, there are no studies exploring how the effectivity of the carbon nanotubes (CNTs) is affected by different methods of production. In this study, we characterize the structure and biocompatibility of four different types of MWCNTs in rat astrocytes and in RG2 glioma cells as well as the induction of cell lysis and possible additive effect of the combination of MWCNTs with temozolomide. We used undoped MWCNTs (labeled simply as MWCNTs) and nitrogen-doped MWCNTs (labeled as N-MWCNTs). The average diameter of both pristine MWCNTs and pristine N-MWCNTs was ~22 and ~35 nm, respectively. In vitro and in vivo results suggested that these CNTs can be used as adjuvant therapy along with the standard treatment to increase the survival of rats implanted with malignant glioma.

Condiciones para el desarrollo de Beauveria bassiana y Metarhizium anisopliae para el control biológico de chapulín frijolero

El chapulín frijolero (Brachystola magna Girard), es un problema en la zona temporalera del estado de Chihuahua, ya que afecta más del 60 % de la superficie sembrada anualmente. Para su control se emplean insecticidas organofosforados y cebos envenenados (CESAVECH, 2001); sin embargo, su uso excesivo ha provocado resistencia de la plaga, acumulación de residuos en el medio ambiente y daños a la flora y fauna silvestre benéfica. Como una alternativa de control biológico se considera el uso de organismos benéficos, que pueden ser incorporados al manejo integrado de plagas, sin efectos nocivos para el medio ambiente y la salud del hombre y los animales (Jiménez 1998). En este trabajo se estudiaron las condiciones óptimas (medio de cultivo, luz y temperatura) para el desarrollo de los aislamientos nativos de hongos entomopatógenos Beauveria bassiana (Bb001) y Metarhizium anisopliae (Ma002), con el fin de utilizarlas en la regulación de la población del chapulín frijolero. Los aislamientos se evaluaron en siete medios de cultivo y siete temperaturas. La mayor esporulación se observó en el medio SDAY. El aislamiento Bb001 mostró el mayor crecimiento en AHM. El crecimiento y esporulación fueron mayores bajo oscuridad continua y a una temperatura de 25 °C. Por otro lado, Ma002 mostró mayor crecimiento en SDA, mayor crecimiento en oscuridad continua, mayor esporulación con luz continua y la temperatura óptima fue de 30 °C. Los resultados mostraron que pueden controlarse adecuadamente las variables ambientales en el laoboratorio, para la reproducción de los hongos B. bassiana (Bb001) y M. anisopliae (Ma002), aislamientos prometedores como una alternativa de control biológico. Abstract The bean grasshopper (Brachystola magna Girard) is a problem in the temporal zone of Chihuahua, because affects above 60 % of the annually sown surface. Organophosphate insecticides and poisoned baits are used to control this insect (CESAVECH, 2001); however, their excessive use has led to pesticide resistance, residues accumulation in the environment affecting beneficial wild flora and fauna. The use of benefical organisms is an alternative of biological control to be incorporated in any integrated pest management. It does not have effects to the environment, nor produce damage on health of men and animals (Jiménez, 1998). In this research, the environmental conditions were studied (culture medium, light and temperature effect), which are suitable for the development of native isolates of entomopathogenic fungus Bauveria bassiana (Bb001) y Metarhizium anisopliae (Ma002). The environmental control is important to regulate growth of bean grasshopper population in temporal region of Chihuahua state. The isolates were evaluated in seven culture mediums and seven temperatures. The greatest isolates sporulation was observed in SDAY. The isolate Bb001 had the best growth in AHM. Isolates growth and sporulation were better under continuos darkness and at 25 °C temperature. On the other hand, Ma002 showed the best growth in SDA, and under continuos darkness; however, the highest sporulation was observed under continuos light and at 30 °C temperature. The results demostrated that lab environmental variables can be controled for growth and development of entomopathogenic fungus B. bassiana and M. anisopliae, which are promising isolates as an alternative of biological control. Keywords: Entomopathogenic fungus, biological control, beneficial organisms, culture mediums, Brachystola magna, bio insecticides

MODELO DE GESTIÓN ACADÉMICA PARA DISMINUIR LA DESERCIÓN DE LOS ESTUDIANTES DE NUEVO INGRESO DEL TECNOLÓGICO NACIONAL DE MÉXICO, EN CELAYA (ACADEMIC MANAGEMENT MODEL TO DECREASE THE DROPOUT PROBLEM OF THE FIRST SEMESTER STUDENTS OF THE TECNOLÓGICO NACIONAL DE MÉXICO EN CELAYA)

ResumenEl objetivo de esta investigación es proponer una estrategia de solución a la problemática de deserción de los alumnos de primer semestre del Tecnológico Nacional de México, en Celaya. El perfil muestral de 636 alumnos, representa un promedio de 13% del total de bajas definitivas en los años 2014, 2015 y 2016. Debido a este problema de deserción, los estudiantes pierden la posibilidad de concretar su plan de vida y carrera.  La recolección de datos se hizo a través de un instrumento validado. La investigación es exploratoria. La relevancia de la investigación consiste en que, una vez identificadas las causas de deserción, se implemente un modelo de gestión académica que impacte en la disminución de la misma. Este modelo será propuesto a los departamentos académicos de la institución para trabajar en su implementación.Palabras clave: deserción, modelo de gestión académica, plan de vida. Abstract The purpose of this research is to propose a strategy to solve the dropout problem of the first semester students from the Tecnológico Nacional de México in Celaya. The sample profile shows that 636 students, representing an average of 13% from the total students registered for the 2014, 2015 and 2016 periods. Due to this dropout problem, the students are not able to conclude their life and career plans. The data collection was made with a previously validated instrument through an exploratory research. The relevance of this research shows that, once the dropout causes are identified, an academic management model has to be implemented to decrease the current rate. This model will later be presented to the university´s academic departaments to work on its implementation.Keywords: dropout, academic management model, life plan

Leading order analysis of neutrino induced dimuon events in the CHORUS experiment

We present a leading order QCD analysis of a sample of neutrino induced charged-current events with two muons in the final state originating in the lead-scintillating fibre calorimeter of the CHORUS detector. The results are based on a sample of 8910 neutrino and 430 antineutrino induced opposite-sign dimuon events collected during the exposure of the detector to the CERN Wide Band Neutrino Beam between 1995 and 1998. % with $E_{\mu 1},E_{\mu 2} > 5$ GeV and $Q^2 > 3$ GeV$^2$ collected %between 1995 and 1998. The analysis yields a value of the charm quark mass of \mc = (1.26\pm 0.16 \pm 0.09) \GeVcc and a value of the ratio of the strange to non-strange sea in the nucleon of $\kappa = 0.33 \pm 0.05 \pm 0.05$, improving the results obtained in similar analyses by previous experiments.Comment: Submitted to Nuclear Physics

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO