602 research outputs found

    Una actividad física eficiente ante el reto de una sociedad de jóvenes influenciada por el modernismo y la tecnología

    Get PDF
    Actualmente los jóvenes se encuentran influenciados por un estilo de vida dominado por la modernidad y los avances tecnológicos, lo que deriva en una vida sedentaria que produce efectos nocivos en todos los sentidos y todos los ámbitos. Esto, aunado a los programas de un sistema institucional educativo y deportivo con innumerables carencias, nos lleva a una situación más complicada, en la que se añaden factores perjudiciales que abarcan la ignorancia, la incapacidad y los intereses personales, que no nos ayudan a edificar alternativas que comiencen a funcionar. Es primordial el establecimiento de una solución pronta y efectiva, encaminada a sistematizar una actividad física adecuada, basada en argumentos científicos y métodos acordes, que nos provean los diversos beneficios que su práctica otorga y nos ayuden a detener el proceso de deterioro físico, al cual el ritmo de vida actual no arroja

    Evaluación de las causas de falla de un dique usando redes bayesianas

    Get PDF
    Context: Forensic geotechnical engineering aims to determine the most likely causes leading to geotechnical failures. Standard practice tests a set of credible hypotheses against the collected evidence using backward analysis and complex but deterministic geotechnical models. Geotechnical models involving uncertainty are not usually employed to analyze the causes of failure, even though soil parameters are uncertain, and evidence is often incomplete. Method: This paper introduces a probabilistic model approach based on Bayesian Networks to test hypotheses in light of collected evidence. Bayesian networks simulate patterns of human reasoning under uncertainty through a bidirectional inference process known as “explaining away.” In this study, Bayesian Networks are used to test several credible hypotheses about the causes of levee failures. Probability queries and the K-Most Probable Explanation algorithm (K-MPE) are used to assess the hypotheses. Results: This approach was applied to the analysis of a well-known levee failure in Breitenhagen, Germany, where previous forensic studies found a multiplicity of competing explanations for the causes of failure. The approach allows concluding that the failure was most likely caused by a combination of high phreatic levels, a conductive layer, and weak soils, thus allowing to discard a significant number of competing explanations. Conclusions: The proposed approach is expected to improve the accuracy and transparency of conclusions about the causes of failure in levee structures.Contexto: La ingeniería geotécnica forense tiene como objetivo determinar las causas más probables que conducen a fallas de tipo geotécnico. La práctica habitual pone a prueba un conjunto de hipótesis a la luz de la evidencia, utilizando análisis retrospectivos y modelos geotécnicos complejos pero deterministas. Los modelos geotécnicos que involucran incertidumbre no suelen emplearse para analizar las causas de falla, a pesar de que los parámetros del suelo son inciertos y la evidencia suele ser incompleta. Método: Este artículo presenta un enfoque de modelo probabilístico basado en redes bayesianas para evaluar hipótesis con base en la evidencia recolectada. Las redes bayesianas simulan patrones de razonamiento humano bajo incertidumbre a través de un proceso de inferencia bidireccional conocido como explaining away [explicación]. En este estudio, las redes bayesianas se utilizan para probar hipótesis creíbles sobre las causas de falla de un dique. Para evaluar las hipótesis se utilizan consultas de probabilidad y el algoritmo de explicación más probable (K-MPE). Resultados: El enfoque se empleó en el análisis de un dique en Breitenhagen, Alemania, donde varios estudios forenses anteriores encontraron multiplicidad de explicaciones contrapuestas acerca de las causas de falla. El enfoque permite concluir que la causa más probable de falla fue una combinación de altos niveles freáticos, una capa de suelo de alta permeabilidad y suelos de baja resistencia, lo que permitió descartar un número significativo de explicaciones contrapuestas. Conclusiones: Se espera que el enfoque probabilístico propuesto mejore la precisión y la transparencia de las conclusiones sobre las causas de falla en estructuras tipo dique

    Dismorfia muscular y uso de sustancias ergogénicas. Una revisión sistemática.

    Get PDF
    El uso de sustancias ergogénicas (USE) no se restringe a la consecución de un mayor desempeño atlético, actualmente también es una conducta de cambio corporal, vía el desarrollo muscular; no obstante, poco se sabe de la relación entre dismorfia muscular (DM) y USE. Por tanto se realizó una revisión sistemática de los estudios empíricos que, durante la última década (2004-2014), la han examinado. De entrada, destaca el hecho de que, de los 22 artículos analizados, solo en 13 se explicita este interés. Además, aunque los datos documentados delinean algunas vertientes relevantes, como la existencia de una alta concomitancia (60-90%) de DM y USE, en general las evidencias son aún incipientes e inciertas, principalmente debido a la gran disparidad metodológica entre estudios y, particularmente, en cuanto a los indicadores, los parámetros y las medidas que, en el contexto de la DM, se han venido empleando para evaluar USE

    Immune protection against Trypanosoma cruzi induced by TcVac4 in a canine model

    Get PDF
    Chagas disease, caused by Trypanosoma cruzi, is endemic in southern parts of the American continent. Herein, we have tested the protective efficacy of a DNA-prime/T. rangeli-boost (TcVac4) vaccine in a dog (Canis familiaris) model. Dogs were immunized with two-doses of DNA vaccine (pcDNA3.1 encoding TcG1, TcG2, and TcG4 antigens plus IL-12- and GMCSF- encoding plasmids) followed by two doses of glutaraldehyde-inactivated T. rangeli epimastigotes (TrIE); and challenged with highly pathogenic T. cruzi (SylvioX10/4) isolate. Dogs given TrIE or empty pcDNA3.1 were used as controls. We monitored post-vaccination and post-challenge infection antibody response by an ELISA, parasitemia by blood analysis and xenodiagnosis, and heart function by electrocardiography. Post-mortem anatomic and pathologic evaluation of the heart was conducted. TcVac4 induced a strong IgG response (IgG2>IgG1) that was significantly expanded post-infection, and moved to a nearly balanced IgG2/IgG1 response in chronic phase. In comparison, dogs given TrIE or empty plasmid DNA only developed high IgG titers with IgG2 predominance in response to T. cruzi infection. Blood parasitemia, tissue parasite foci, parasite transmission to triatomines, electrocardiographic abnormalities were significantly lower in TcVac4-vaccinated dogs than was observed in dogs given TrIE or empty plasmid DNA only. Macroscopic and microscopic alterations, the hallmarks of chronic Chagas disease, were significantly decreased in the myocardium of TcVac4-vaccinated dogs.We conclude that TcVac4 induced immunity was beneficial in providing resistance to T. cruzi infection, evidenced by control of chronic pathology of the heart and preservation of cardiac function in dogs. Additionally, TcVac4 vaccination decreased the transmission of parasites from vaccinated/infected animals to triatomines.CONACYT PROY No. 156701 UAEM PROY No. 2381/2006U National Institutes of Health/National Institute of Allergy and Infectious Diseases http://www.niaid.nih.gov/Pages/ default.aspx GRANT NUMBER (AI072538) NJG; American Heart Association http://www.heart.org/ HEARTORG/ GRANT NUMBER (0855059F) to NJG

    RELACIÓN ENTRE SOMNOLENCIA Y TURNOS DE TRABAJO EN UNA MUESTRA DE POLICÍA LOCAL.

    Get PDF
    Background: Excesive daytime sleepiness is a frequent in our socirty and a public health problem due to it association with work and traffic accidents. The aim of the present study is to evaluate the relationship between daytime somnolence, as measured by the ESS and shift-work in a sample of local policemen. Results: Our results show that policemen in permanent shift and morning shift present higher scores in daytime sleepiness. Besides, in this study 36,5% of the sample suffered a job accident, and in 9% of this sample, the accidents were associated to fatigue.Fundamento: La somnolencia diurna excesiva es un síntoma frecuente en nuestra sociedad y un importante problema de salud publica debido a su asociación con los accidentes laborales y de tráfico. El objetivo del presente estudio es establecer la relación entre somnolencia diurna medida con el ESS y los diferentes turnos de trabajo, en una muestra de policía local. Resultados: Indican que los agentes que se encuentran en el turno fijo y de mañana presentan mayores puntuaciones en somnolencia diurna. También se establece en este estudio que un 36,5% de la muestra padecieron un accidente laboral y que de ellos un 9% establecen que fueron debidos a la fatiga

    Outcomes of abdominal wall reconstruction in patients with the combination of complex midline and lateral incisional hernias.

    Get PDF
    Background The best treatment for the combined defects of midline and lateral incisional hernia is not known. The aim of our multicenter study was to evaluate the operative and patient-reported outcomes using a modified posterior component separation in patients who present with the combination of midline and lateral incisional hernia. Methods We identified patients from a prospective, multicenter database who underwent operative repairs of a midline and lateral incisional hernia at 4 centers with minimum 2-year follow-up. Hernias were divided into a main hernia based on the larger size and associated abdominal wall hernias. Outcomes reported were short- and long-term complications, including recurrence, pain, and bulging. Quality of life was assessed with the European Registry for Abdominal Wall Hernias Quality of Life score. Results Fifty-eight patients were identified. Almost 70% of patients presented with a midline defect as the main incisional hernia. The operative technique was a transversus abdominis release in 26 patients (45%), a modification of transversus abdominis release 27 (47%), a reverse transversus abdominis release in 3 (5%), and a primary, lateral retromuscular preperitoneal approach in 2 (3%). Surgical site occurrences occurred in 22 patients (38%), with only 8 patients (14%) requiring procedural intervention. During a mean follow-up of 30.1 ± 14.4 months, 2 (3%) cases of recurrence were diagnosed and required reoperation. There were also 4 (7%) patients with asymptomatic but visible bulging. The European Registry for Abdominal Wall Hernias Quality of Life score showed a statistically significant decrease in the 3 domains (pain, restriction, and cosmetic) in the postoperative score compared with the preoperative score. Conclusion The different techniques of posterior component separation in the treatment of combined midline and lateral incisional hernia show acceptable results, despite the associated high complexity. Patient-reported outcomes after measurement of the European Registry for Abdominal Wall Hernias Quality of Life score demonstrated a clinically important improvement in quality of life and pain.post-print2.323 K

    Identification of tissue microRNAs predictive of sunitinib activity in patients with metastatic renal cell carcinoma

    Get PDF
    PURPOSE: To identify tissue microRNAs predictive of sunitinib activity in patients with metastatic renal-cell-carcinoma (MRCC) and to evaluate in vitro their mechanism of action in sunitinib resistance. METHODS: We screened 673 microRNAs using TaqMan Low-density-Arrays (TLDAs) in tumors from MRCC patients with extreme phenotypes of marked efficacy and resistance to sunitinib, selected from an identification cohort (n = 41). The most relevant differentially expressed microRNAs were selected using bioinformatics-based target prediction analysis and quantified by qRT-PCR in tumors from patients presenting similar phenotypes selected from an independent cohort (n = 101). In vitro experiments were conducted to study the role of miR-942 in sunitinib resistance. RESULTS: TLDAs identified 64 microRNAs differentially expressed in the identification cohort. Seven candidates were quantified by qRT-PCR in the independent series. MiR-942 was the most accurate predictor of sunitinib efficacy (p = 0.0074). High expression of miR-942, miR-628-5p, miR-133a, and miR-484 was significantly associated with decreased time to progression and overall survival. These microRNAs were also overexpressed in the sunitinib resistant cell line Caki-2 in comparison with the sensitive cell line. MiR-942 overexpression in Caki-2 up-regulates MMP-9 and VEGF secretion which, in turn, promote HBMEC endothelial migration and sunitinib resistance. CONCLUSIONS: We identified differentially expressed microRNAs in MRCC patients presenting marked sensitivity or resistance to sunitinib. MiR-942 was the best predictor of efficacy. We describe a novel paracrine mechanism through which high miR-942 levels in MRCC cells up-regulates MMP-9 and VEGF secretion to enhance endothelial migration and sunitinib resistance. Our results support further validation of these miRNA in clinical confirmatory studies
    corecore