2,512 research outputs found

    The use of sarcasm in the classroom as a tool for the development of pragmatic competence in ELT learners: A case study

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    “The Common European Framework of Reference for Languages CEFR, (2002) provides a common basis for the development of language programs, curriculum guidelines, examinations, textbooks and so on, throughout Europe. It also describes a comprehensive way of what language students have to learn to use a language for communication, and the knowledge and skills they need to develop in order to act effectively. The CEFR helps evaluate a good quality of education in higher language education. In addition, this framework provides levels in which it is possible to classify to the language learners according to the fluency and language domain that they possess. These levels are from the basic level “A1” to the advanced level “C2”, in which are located those who dominate the language. At Benemérita Universidad Autónoma de Puebla (BUAP), the Modelo Universitario Minerva (MUM) is in force, which is characterized by its constructivist approach. MUM (2007) establishes that the teacher will have the role of a mediator inside the classroom, also, it establishes the competencies the students will have so that he/she could apply for an academic exchange to national and international institutions after his /her integral formation in his/her major. The main purpose of the MUM is to get good students through a constructivist approach.

    Evolution of the phase-space density and the Jeans scale for dark matter derived from the Vlasov-Einstein equation

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    We discuss solutions of Vlasov-Einstein equation for collisionless dark matter particles in the context of a flat Friedmann universe. We show that, after decoupling from the primordial plasma, the dark matter phase-space density indicator Q remains constant during the expansion of the universe, prior to structure formation. This well known result is valid for non-relativistic particles and is not "observer dependent" as in solutions derived from the Vlasov-Poisson system. In the linear regime, the inclusion of velocity dispersion effects permits to define a physical Jeans length for collisionless matter as function of the primordial phase-space density indicator: \lambda_J = (5\pi/G)^(1/2)Q^(-1/3)\rho_dm^(-1/6). The comoving Jeans wavenumber at matter-radiation equality is smaller by a factor of 2-3 than the comoving wavenumber due to free-streaming, contributing to the cut-off of the density fluctuation power spectrum at the lowest scales. We discuss the physical differences between these two scales. For dark matter particles of mass equal to 200 GeV, the derived Jeans mass is 4.3 x 10^(-6) solar masses.Comment: 18 pages, 2 figures. Accepted for publication in JCA

    Estudio del comportamiento de pinturas acrílicas sobre tablero contrachapado tras envejecimiento artificial

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    Entre los soportes más empleados en arte contemporáneo se encuentran los tableros derivados de la madera. Hasta el momento, las investigaciones para determinar la influencia de un soporte de tablero contrachapado en capas pictóricas acrílicas así como las condiciones óptimas para su conservación, resultan insuficientes o completamente ausentes. En la elaboración de estos tableros se utilizan adhesivos para darles consistencia pero la influencia de estos adhesivos en las capas pictóricas artísticas estará en función del tipo de tablero, del tipo de adhesivo empleado, de las condiciones ambientales y de las características de las capas pictóricas. Es evidente pues, la necesidad de modelos comparativos. Por todos estos motivos, el objetivo principal de esta investigación ha sido comprender la transformación que experimentan estos materiales durante su envejecimiento y las causas que pueden desestabilizar las obras, con el fin de adoptar las medidas necesarias para evitar un envejecimiento prematuro. Mediantela Espectroscopía Infrarroja por Transformada de Fourier FTIR se han analizado los cambios sufridos por modelos experimentales realizados con pinturas acrílicas imprimidas sobre tablero contrachapado trasser sometidos a ciclos de envejecimiento por choquetérmico (Cold-check test) y envejecimiento en condiciones de alta humedad

    a case–control study

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    Objectives: To determine the association between Toxoplasma gondii infection and Parkinson's disease and to investigate whether T. gondii seropositivity is associated with the general characteristics of patients with Parkinson's disease. Design Case–control study. Setting: Cases and controls were enrolled in Durango City, Mexico. Participants: 65 patients with Parkinson's disease and 195 age- and gender-matched control subjects without Parkinson's disease. Primary and secondary: outcome measures Serum samples of participants were analysed for anti-T. gondii IgG and IgM antibodies by commercially available enzyme-linked immunoassays. Prevalence of T. gondii DNA was determined in seropositive subjects using PCR. The association between clinical data and infection was examined by bivariate analysis. Results: Anti-T. gondii IgG antibodies were found in 6/65 cases (9.2%) and in 21/195 controls (10.8%) (OR 0.84; 95% CI 0.32 to 2.18; p=0.81). The frequency of high (>150 IU/mL) antibody levels was similar among cases and controls (p=0.34). None of the anti-T. gondii IgG positive cases and four of the anti-T. gondii IgG positive controls had anti-T. gondii IgM antibodies (p=0.54). The prevalence of T. gondii DNA was comparable in seropositive cases and controls (16.7% and 25%, respectively; p=1.0). Seroprevalence of T. gondii infection was associated with a young age onset of disease (p=0.03), high Unified Parkinson Disease Rating Scale scores (p=0.04) and depression (p=0.02). Seropositivity to T. gondii infection was lower in patients treated with pramipexole than in patients without this treatment (p=0.01). However, none of the associations remained significant after Bonferroni correction. Conclusions: The results do not support an association between T. gondii infection and Parkinson's disease. However, T. gondii infection might have an influence on certain symptoms of Parkinson's disease. Further research to elucidate the role of T. gondii exposure on Parkinson's disease is warranted

    Instalación de la defensa ribereña con gaviones y la evaluación del impacto ambiental del proyecto en el distrito de Paucas – Huari – Áncash

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    La presente investigación tuvo como propósito hacer el diseño estructural de la defensa ribereña con gaviones para luego hacer la evaluación de impacto ambiental del proyecto que se encuentra en el distrito de Paucas, para lo cual se inició con el análisis hidrológico e hidráulico para poder estimar todos los datos necesarios requeridos para el diseño estructural de los gaviones correspondiente a la defensa ribereña, después se realizó la evaluación del impacto ambiental estudiando las partidas del proyecto para luego identificar y valorar los impactos ambientales producidos por la instalación de la defensa ribereña con gaviones, al iniciar la investigación se realizó el modelamiento hidrológico con el programa Arc Gis y luego se exportó los resultados al programa Google Earth y así definir los parámetros necesarios para la tesis, luego se analizaron las tormentas y sus resultados fueron llevados al programa HEC HMS, obteniendo el caudal de diseño requerido para así hacer el modelamiento hidráulico con el programa HEC RAS para obtener el tirante del canal, el análisis se realizó con un periodo de retorno de 100 años por que el proyecto se encuentra en la zona urbana. Por otra parte, se hizo la evaluación de impacto ambiental del proyecto por medio del estudio de las partidas, que dio como resultado los impactos ambientales producidos por la ejecución de la obra, luego estos impactos ambientales se llevaron a una matriz de Leopold que sirvió para valorar y ver el grado de impacto producido por la ejecución de la obra, por último, se propuso un diseño de las medidas de mitigación y prevención para así poder disminuir los impactos ambientales

    Use of elicitors as an approach for sustainable agriculture

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    Plant pathogens are responsible for large declines in agricultural production. Their control is carried out mainly by chemical and frequently proposed biological methods to reduce their environmental impact. On the other hand, plant-pathogen or microbe interactions generate multiple signals within plants activating defense mechanism, some of which can also be induced by elicitors (protective molecules). Elicitor-induced plant signaling serves as a guide to a series of intracellular events that end in activation of transduction cascades and hormonal pathways triggering induced resistance (IR) and consequently activation of plant immunity to environmental stresses. So, it is necessary to understand where and how elicitors act in cellular defense mechanism of crops, to improve protection and management for sustainable crop. Therefore this review focused on main topics that guide induced resistance and therefore activation of plant immune response.Keywords: Elicitors, defense mechanism, Immune response, Induced resistance, MAP

    Analogies between geminivirus and oncovirus: Cell cycle regulation

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    Geminiviruses are a large family of plant viruses whose genome is composed of one or two circular and single strand of DNA. They replicate in the cell nucleus being Rep protein, the only viral protein necessary for their replication process. Geminiviruses as same as animal DNA oncoviruses, like SV40, adenovirus and papillomavirus, use the host replication machinery to replicate their DNA. Consequently, they alter host cell cycle regulation to create a suitable environment for their replication. One of the events involved in this alteration would be the inactivation of the retinoblastoma protein (pRb) that negatively regulates the G1/S transition in cells. The discovery of one homologue of the pRb in plants and the finding that Rep protein of some geminiviruses interacts with human retinoblastoma protein, as well as animal virus oncoproteins, is very interesting. This finding laid the groundwork for subsequent detection of analogies between geminiviruses and animal DNA tumor viruses, especially in their interaction with pRb. Moreover, the finding allowed the determination of how this interaction affects the regulation of the cell cycle in plants and animals. Accumulated knowledge generates new interesting questions and possible implications, and so, in this document, we dare to watch in that direction.Key words: Geminivirus, oncovirus, retinoblastoma protein, cell cycle regulation, endoreduplication

    a case–control seroprevalence study

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    Background Infection with Toxoplasma gondii can be acquired via the ingestion of undercooked or raw meat containing tissue cysts, or via ingestion of water contaminated with oocysts. Professional long distance truck driving may have epidemiological importance for food-borne infections since drivers eat out of home and in places where hygiene and cooking practices are uncertain. We aimed to determine whether interstate truck drivers in Durango, Mexico have an increased risk of infection with T. gondii as indicated by seropositivity; and to determine the socio-demographic, work, clinical, and behavioral characteristics associated with T. gondii seropositivity in interstate truck drivers. Methods Through a case–control study design, 192 truck drivers and 192 controls from the general population of the same region matched by gender and age were examined with enzyme-linked immunoassays for the presence of anti-Toxoplasma IgG and IgM antibodies. Socio-demographic, work, clinical and behavioral characteristics from the truck drivers were obtained. Results Anti-T. gondii IgG antibodies were found in 23 (12.0%) of 192 truck drivers and in 13 (6.8%) of 192 controls (OR = 21.0; 95% CI: 1.23-358.38; P = 0.002). Anti-T. gondii IgM antibodies were found in 7 (3.6%) cases and in 7 (3.6%) controls (P = 1.00). The seroprevalence of T. gondii infection was higher in drivers with reflex impairment than in those without this impairment (4/13, 30.8% vs 19/179, 10.6%, respectively; P = 0.05), and in drivers with hearing impairment than in those without this impairment (3/7, 42.9% vs 20/185, 10.8%, respectively; P = 0.03). Multivariate analysis of work and behavioral characteristics of truck drives showed positive associations of T. gondii exposure with trips to the south of Mexico (OR = 3.11; 95% CI: 1.02-9.44; P = 0.04) and consumption of horse meat (OR = 5.18; 95% CI: 1.62-16.55; P = 0.005). Conclusions Results suggest that interstate truck drivers may have an increased risk for T. gondii infection, and that T. gondii exposure may be impacting neurological functions in truck drivers. Contributing factors for T. gondii exposure should be taken into account for the design of optimal prevention measures against T. gondii infection
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