Chronic Delivery of a Thrombospondin-1 Mimetic Decreases Skeletal Muscle Capillarity in Mice

Angiogenesis is an essential process for normal skeletal muscle function. There is a growing body of evidence suggesting that thrombospondin-1 (TSP-1), a potent antiangiogenic protein in tumorigenesis, is an important regulator of both physiological and pathological skeletal muscle angiogenesis. We tested the hypothesis that chronic exposure to a TSP-1 mimetic (ABT-510), which targets the CD36 TSP-1 receptor, would decrease skeletal muscle capillarity as well as alter the balance between positive and negative angiogenic proteins under basal conditions. Osmotic minipumps with either ABT-510 or vehicle (5% dextrose) were implanted subcutaneously in the subscapular region of C57/BL6 mice for 14 days. When compared to the vehicle treated mice, the ABT-510 group had a 20% decrease in capillarity in the superficial region of the gastrocnemius (GA), 11% decrease in the plantaris (PLT), and a 35% decrease in the soleus (SOL). ABT-510 also decreased muscle protein expression of vascular endothelial growth factor (VEGF) in both the GA (−140%) and SOL (−62%); however there was no change in VEGF in the PLT. Serum VEGF was not altered in ABT-510 treated animals. Endogenous TSP-1 protein expression in all muscles remained unaltered. Tunnel staining revealed no difference in muscle apoptosis between ABT-510 and vehicle treated groups. These data provide evidence that the anti-angiogenic effects of TSP-1 are mediated, at least in part, via the CD36 receptor. It also suggests that under physiologic conditions the TSP-1/CD36 axis plays a role in regulating basal skeletal muscle microvessel density

The acceptance and use of the e-learning systems among the university teachers in Ecuador

The success of an e-learning system depends largely on the acceptance and use that teachers give this tool. After critically evaluate models of technology adoption, including the Technology Acceptance Model (TAM) and TAM2, we built a conceptual model to predict the level of acceptance and use of e-learning system among teachers. This model extends TAM2 and includes technical support, computer self-efficacy, social influence, perceived enjoyment and satisfaction. Data were collected from 145 teachers of a University in Ecuador. For data collection, a form in Likert scale was sent by email. Upon receipt of the data, these missing data reported 4.2%, to correct this data imputation method it was applied for replacement by mean. After performing the checks about satisfactory reliability and validity, the structural model was tested using PLS. The results indicate that perceived ease of use and perceived usefulness have a direct effect on the intension of using e-learning systems. Perceived enjoyment, perceived ease of use and social influence have a direct effect on the perceived usefulness. Perceived enjoyment and computer self-efficacy both have a direct effect on perceived ease of use of e-learning systems. Universities Principals should not only worry about the basic design of e-learning systems, but also explicitly address individual differences among teachers using e-learning system.Postprint (published version

Modelo de competencias para microempresarios como instrumento de desarrollo productivo

Los microempresarios generalmente desconocen sus competencias básicas, en especial su aplicación y los beneficios que se obtienen cuando estas competencias se vinculan con el desarrollo de la gestión empresarial. Bajo ésta premisa, se propone un modelo de competencias dirigido exclusivamente a los microempresarios. Las competencias son debidamente identificadas y agrupadas en sectores mediante la revisión de literatura y una investigación de campo. Las competencias obtenidas están orientadas a una fácil y correcta aplicación, y distribuidas en los ámbitos de acción en que los microempresarios realizan sus actividades, tendientes a fortalecer su desarrollo productivo y motivar su formación personal y profesional.Postprint (published version

Competency model for microentrepreneurs in depressed environments

Microentrepreneurs who have their businesses located in depressed regions are generally unaware of their basic competencies, especially their application and the benefits that are obtained when these are linked to the development of business management. Under this premise, this study aims to propose a competency model for microentrepreneurs to offer them a better understanding of how basic competences can improve their management actions and business performance. The competences in dimensions are identified and grouped; likewise, the importance of the model is determined with the support of a panel of experts linked to the micro enterprise sector. The competences proposed are distributed in the areas of action in which microentrepreneurs develop their activities. As a result, the model establishes 27 competencies that determine microentrepreneurs’ competences in depressed environments. Benefits for microentrepreneurs are additional knowledge to plan better training in basic competences and the improvement of their management skills and business performancePostprint (author's final draft

Aceptación y uso de los sistemas e-learning por estudiantes de grado de Ecuador : el caso de una universidad estatal

Objeto: El objetivo de esta investigación fue adaptar el Modelo de Aceptación de la Tecnología (TAM) para predecir el uso y la intención de uso de los sistemas e-learning entre los estudiantes de grado de una universidad estatal en Ecuador, con la intención de mejorar el entendimiento de los factores que puedan potenciar el uso de estos sistemas y facilitar la aplicación de políticas para incrementar los beneficios que éstos aportan al proceso de enseñanza y aprendizaje. Diseño/metodología/enfoque: El análisis tiene fundamento epistemológico en lo empírico-inductivo, basado en la observación de la percepción. En base a la revisión de la literatura científica sobre la evaluación y aceptación de los sistemas e-learning, se ha adaptado el modelo al caso de Ecuador y se ha elaborado un cuestionario con 52 ítems basado en escalas de Likert. El instrumento fue enviado por correo electrónico a 600 estudiantes de grado de una universidad estatal en Ecuador, respondiendo satisfactoriamente 423 de ellos. Se realizaron comprobaciones de validez y fiabilidad del modelo de ecuaciones estructurales por mínimos cuadrados parciales (PLS), con el soporte del software estadístico SmartPLS. Aportaciones y resultados: Los resultados indican que todas las hipótesis del TAM se cumplen en el contexto ecuatoriano, al momento de evaluar la aceptación de los sistemas e-learning entre los estudiantes de grado de una universidad estatal. El principal aporte fue identificar que el entretenimiento percibido, la influencia social y la auto-eficacia computacional, tienen un efecto directo sobre los dos constructos principales del TAM, facilidad de uso percibida (PEOU) y utilidad percibida (PU). También se encontró que la satisfacción (S) recibe una elevada influencia directa de PU y a su vez S influye en el uso de los sistemas e-learning, siendo el primero un aporte específico de este estudio. El soporte técnico reflejó no tener influencia sobre los constructos fundamentales del TAM. Limitaciones: La investigación fue realizada a los estudiantes de grado en una sola universidad estatal categoría B de Ecuador, siendo la realidad de este país más compleja, al existir cuatro categorías con características distintas. Tampoco se han considerado la edad, género, estudiantes de posgrado, condición socio económica, entre otras características de los estudiantes que puede afectar la investigación. Implicaciones prácticas: La identificación de los factores que influyen en la aceptación y uso de los sistemas e-learning, contribuirá a crear y mejorar los entornos de enseñanza aprendizaje para los estudiantes universitarios. Permitiendo explotar con mayor eficiencia los beneficios de estas herramientas tecnológicas, adaptándolas a las políticas de gestión de las instituciones de educación superior. Originalidad / Valor añadido: Este artículo presenta datos empíricos sobre el uso y aceptación de los sistemas e-learning en los estudiantes de una determinada universidad de Ecuador. No se evidencian estudios similares en el país y el modelo puede ser considerado para futuros estudios de alcance nacional.Postprint (published version

The Effects of Training on the Competitive Economic Advantage of Companies in Spain

The search for factors that lead to competitive advantage in a company in relation to its competitors is a widely debated subject; a wide range of issues have been examined to determine which factors are the most influential. The aim of this paper is to study training effect on business results (particularly on firm's financial turnover). For the present research, the classical model of Industrial Economy as a frame of reference has been used. The data collection instrument was a questionnaire sent to 381 large organizations in Catalonia (Spain) during 2009 and 2010. The empirical section of the present article was developed using structural equation modeling (SEM). Results relate training to company's financial turnover in a positive way. The General Expenditure and Costs is the variable that most contributes to the explanation of firms' financial turnover. The Organization of Training variable is the second most important construct to account for financial turnover However, training is required to be well organized as well as properly financed

Fibroblast growth factor receptor 5 (FGFR5) is a co-receptor for FGFR1 that is up-regulated in beta-cells by cytokine-induced inflammation

Fibroblast growth factor receptor-1 (FGFR1) activity at the plasma membrane is tightly controlled by the availability of co-receptors and competing receptor isoforms. We have previously shown that FGFR1 activity in pancreatic beta-cells modulates a wide range of processes, including lipid metabolism, insulin processing, and cell survival. More recently, we have revealed that co-expression of FGFR5, a receptor isoform that lacks a tyrosine-kinase domain, influences FGFR1 responses. We therefore hypothesized that FGFR5 is a co-receptor to FGFR1 that modulates responses to ligands by forming a receptor heterocomplex with FGFR1. We first show here increased FGFR5 expression in the pancreatic islets of nonobese diabetic (NOD) mice and also in mouse and human islets treated with proinflammatory cytokines. Using siRNA knockdown, we further report that FGFR5 and FGFR1 expression improves beta-cell survival. Co-immunoprecipitation and quantitative live-cell imaging to measure the molecular interaction between FGFR5 and FGFR1 revealed that FGFR5 forms a mixture of ligand-independent homodimers (25%) and homotrimers (75%) at the plasma membrane. Interestingly, co-expressed FGFR5 and FGFR1 formed heterocomplexes with a 2:1 ratio and subsequently responded to FGF2 by forming FGFR5/FGFR1 signaling complexes with a 4:2 ratio. Taken together, our findings identify FGFR5 as a co-receptor that is up-regulated by inflammation and promotes FGFR1-induced survival, insights that reveal a potential target for intervention during beta-cell pathogenesis

Rentabilidad y el costo de estudiar educación superior en Chile: Reflexiones para la discusión

El sistema de educación superior chileno ha dado respuesta a su creciente matrícula y masificación, especialmente en estudiantes de estratos socioeconómicos bajos, a través del aumento importante de becas y préstamos del Estado. Este último instrumento de financiamiento ha posibilitado un aumento de egresados de las universidades chilenas, posibilitándole obtener su título universitario e insertarse en el mercado laboral. En este contexto, el objetivo de este trabajo es aportar a la discusión teórica sobre la problemática de la rentabilidad y el costo de estudiar educación superior en Chile, con el fin de obtener lecciones para nuevas políticas públicas. Para ello, se realiza un enfoque documental. Se evidencia que Chile posee una de las tasas de retorno de la educación superior más alta entre los países de la OECD. Sin embargo, se observa una rentabilidad heterogénea de las carreras, que conlleva realidades distintas en los ingresos de los egresados. Pero más aún se cuestiona, el alto costo de los precios de las carreras y por ende, un elevado endeudamiento de varias generaciones de estudiantes producto de la política de Estado que liberalizó la formas de financiamiento con la presencia de bancos privados y con un importante costo para el aparato estatal que inyectó recursos al sistema para garantizar el riesgo de no pago

Percentage, bacterial etiology and antibiotic susceptibility of acute respiratory infection and pneumonia among children in rural Senegal

Acute respiratory infections (ARI) are still a major health problem in most developing countries. So far no study has evaluated the importance of childhood ARI in rural Senegal. We prospectively studied ARI, the percentage of pneumonia and related mortality, as well as the bacterial composition of nasopharyngeal flora using nasopharyngeal aspirates in 114 children, aged 2-59 months, presenting at Ndioum's pediatric ward. Excluded from the trial were those children that had had antimicrobial therapy in the previous 2 weeks. The Kirby-Bauer method was used to determine antibiotic resistance throughout the study. The percentage of ARI and pneumonia among the population tested was 24 per cent and 11 per cent respectively. Streptococcus pneumonia was often resistant to cotrimoxazole (31 per cent) but only 9 per cent were resistant to chloramphenicol and 14 per cent to penicillin. Haemophilus influenzae (HI) was uniformly sensitive to ampicillin, and only 4 per cent were resistant to chloramphenicol and 11 per cent to cotrimoxazole. We conclude that SP and HI resistance to cotrimoxazole is important and warrants larger clinical trials using chloramphenicol. Information campaigns and intense management of comorbidities are desirable in this type of population. Comorbidities (tuberculosis, malaria, HIV-AIDS, severe malnutrition) are determinant variables in many ARI cases and carry a high negative prognosis value

A new P-wave tomographic model (cap22) for North America: implications for the subduction and cratonic metasomatic modification history of western Canada and Alaska

Our understanding of the present-day state and evolution of the Canadian and Alaskan mantle is hindered by a lack of absolute P-wavespeed constraints that provide complementary sensitivity to composition in conjunction with existing S-wavespeed models. Consequently, cratonic modification, orogenic history of western North America and complexities within the Alaskan Proto-Pacific subduction system remain enigmatic. One challenge concerns the difficulties in extracting absolute arrival-time measurements from often-noisy data recorded by temporary seismograph networks required to fill gaps in continental and global databases. Using the Absolute Arrival-time Recovery Method (AARM), we extract >180,000 new absolute arrival-time residuals from seismograph stations across Canada and Alaska and combine these data with USArray and global arrival-time data from the contiguous US and Alaska. We develop a new absolute P-wavespeed tomographic model, CAP22, spanning North America that significantly improves resolution in Canada and Alaska over previous models. Slow wavespeeds below the Canadian Cordillera sharply abut fast wavespeeds of the continental interior at the Rocky Mountain Trench in southwest Canada. Slow wavespeeds below the Mackenzie Mountains continue farther inland in northwest Canada, indicating Proterozoic-Archean metasomatism of the Slave craton. Inherited tectonic lineaments colocated with this north-south wavespeed boundary suggest that both the crust and mantle may control Cordilleran orogenic processes. In Alaska, fast upper mantle wavespeeds below the Wrangell Volcanic Field favor a conventional subduction related mechanism for volcanism. Finally, seismic evidence for the subducted Kula and Yukon slabs indicate tectonic reconstructions of western North America may require revision