228 research outputs found
Vitamin D3 Receptor (VDR) Gene rs2228570 (Fok1) and rs731236 (Taq1) Variants Are Not Associated with the Risk for Multiple Sclerosis: Results of a New Study and a Meta-Analysis
Background: Some epidemiological, genetic, and experimental data suggest a possible role of vitamin D in the pathogenesis of multiple sclerosis (MS) and in experimental autoimmune encephalomyelitis. Data on the possible contribution of several single nucleotide polymorphisms (SNP) in the vitamin D receptor (VDR) gene to the risk for MS are controversial. Several studies suggested an interaction between some SNPs in the VDR gene and HLADRB1*1501 in the risk for MS.
Objectives: The aim of this study was to investigate a possible influence of the SNPs rs2228570 and rs731236 in the VDR gene in the risk for MS. A secondary objective was to address the possible interactions between VDR genes and HLADRB1*1501.
Methods: We analyzed the allelic and genotype frequency of VDR rs2228570, rs731236, and HLADRB1*1501 (rs3135388) in 303 patients with MS and 310 healthy controls, using TaqMan Assays. We also conducted a meta-analysis, that was carried out by using the software Meta-Disc 1.1.1 (http://www.hrc.es/investigacion/metadisc.html; Unit of Clinical Statistics, Hospital Ramon y Cajal, Madrid, Spain). Heterogeneity between studies in terms of degree of association was tested using the Q-statistic.
Results: VDR rs2228570 and rs731236 allelic and genotype frequencies did not differ significantly between MS patients and controls, and were unrelated with the age of onset of MS, gender, and course of MS. HLADRB1*1501 showed a high association with the risk of developing MS 4.76(95% C. I. = 3.14-7.27; p<0.0001). The meta-analysis, after excluding data of one study that was responsible of heterogeneity for rs731236 polymorphism, showed lack of relation of both SNPs with the risk for MS. HLADRB1*1501 showed lack of interaction with VDR rs2228570 and rs731236 in increasing MS risk.
Conclusions: These results suggest that VDR rs2228570 and rs731236 polymorphisms are not related with the risk for MS, and did not confirm interaction between these VDR SNPs and HLADRB1 in the risk for MS.This work was supported in part by Grants FIS PS09/00943, PS09/00469, and RETICS RD07/0064/0016 from Fondo de Investigación Sanitaria, Instituto de Salud Carlos III, Spain, and GR10068 from Junta de Extremadura, Spain.Peer Reviewe
Competitividad, rendimientos crecientes y comercio intra-industrial en la manufactura peruana, 1970-1995
This essay pretends to show, on the one hand, that the gains of competition are concentrated only on industrial branches with statistically significant increasing returns to scale and, on the other hand, that the significance of intra-industrial trade has been reduced during the last years. The empirical test is done by the use of a model which permits identify the kind of returns to scale existent in each of the 32 industrial branches of the manufacturing sector. Moreover, the econometrics estimation of the model makes it possible to test the importance of the demand factors to explain the trend and the dynamics of growth and capital accumulation in the manufacturing sector.
Competitividad en la industria manufacturera peruana, 1985-1995
This paper is concerned with competition in the peruvian manufacturing industry. A simple model of competition is estimated in order to evaluate the influence of productivity changes and relative labor costs. With this purpose an index of competition was constructed for 32 industrial branches, with export and import data, following the revealed comparative advantages methodology. The period of analysis goes from 1985 to 1995. The labor costs are measured in current dollars. Hence, the exchange rate effects on the competitiveness of the industrial branches are taken into account by the labor cost variable. The model also includes an index of capacity utilization in order to estimate the net effects of productivity and labor cost on the industrial competitiveness. One of the most striking results of this research is that only 8 industrial branches out of 32 considered, won competitiveness during 1985-1995. The trade liberalization and the exchange rate overvaluation are the main responsible for the massive lost of industrial competitiveness during 1991-1995.
Thr105Ile (rs11558538) polymorphism in the histamine N-methyltransferase (HNMT) gene and risk for Parkinson disease A PRISMA-compliant systematic review and meta-analysis
Background/aims: Several neuropathological, biochemical, and pharmacological data suggested a possible role of histamine in the etiopathogenesis of Parkinson disease (PD). The single nucleotide polymorphism (SNP) rs11558538 in the histamine Nmethyltransferase (HNMT) gene has been associated with the risk of developing PD by several studies but not by some others. We carried out a systematic review that included all the studies published on PD risk related to the rs11558538 SNP, and we conducted a meta-analysis following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.
Methods: We used several databases to perform the systematic review, the software Meta-DiSc 1.1.1 to perform the metaanalysis of the eligible studies, and the Q-statistic to test heterogeneity between studies.
Results: The meta-analysis included 4 eligible case–control association studies for the HNMT rs11558538 SNP and the risk for PD (2108 patients, 2158 controls). The frequency of the minor allele positivity showed a statistically significant association with a decreased risk for PD, both in the total series and in Caucasians. Although homozygosity for the minor allele did not reach statistical significance, the test for trend indicates the occurrence of a gene–dose effect. Global diagnostic odds ratios (95% confidence intervals) for rs11558538T were 0.61 (0.46–0.81) for the total group, and 0.63 (0.45–0.88) for Caucasian patients.
Conclusion: The present meta-analysis confirms published evidence suggesting that the HNMT rs11558538 minor allele is related to a reduced risk of developing PD.Trabajo financiado por:
Instituto de Salud Carlos III. Fondo de Investigación Sanitaria. Ayudas PI12/00241, PI12/00324, PI15/00303 y RETICS RD12/0013/0002
Junta de Extremadura y Fondos FEDER. Ayuda GR15026peerReviewe
La economía peruana del último medio siglo : ensayos de interpretación
Los artículos de este libro son el producto de investigaciones sobre la economía peruana del último medio siglo, realizadas entre fines de los años setenta y el año 2000. Durante los últimos cincuenta años ocurrieron tres hechos importantes. En primer lugar, un proceso de sustitución de importaciones que formalmente se inició con la ley de industrialización de 1959 y se agotó en menos de veinte años. En segundo lugar, la crisis de este proceso y el derrumbe del producto bruto interno per cápita durante el primer gobierno de Alan García (1985-1990) hasta los niveles registrados en los años 1959-1960. Y, en tercer lugar, la restauración del modelo primario exportador con la aplicación de políticas y reformas neoliberales desde los primeros años de la década de los noventa
Análisis del rendimiento académico según los niveles de actividad física y satisfacción vital. Una revisión sistemática
[Abstract] Academic performance is one of the most studied variables in the educational context.
Likewise, students' physical activity and quality of life have a direct incidence on their
academic success. Therefore, the aim of this systematic review is to analyse the effects
of physical activity and quality of life on students' academic performance. The Web of
Science, SCOPUS and PubMed databases were used to select articles published
between 2013 and 2023. The criteria established by the Preferred Reporting Items for
Systematic Reviews and Meta-Analyses (PRISMA) statement were followed for the
elaboration of the systematic review, with the final sample of 17 articles. Results show
how regular physical activity improves academic performance in mathematics and
language. Moreover, it is also observed that quality of life also plays a key role in the
drop-out or lower grade point average of students at any educational stage.[Resumen] El rendimiento académico es una de las variables más estudiadas en el contexto educativo. Asimismo, la actividad física y la calidad de vida de los estudiantes tienen una incidencia directa en su éxito académico. Por ello, el objetivo de esta revisión sistemática es analizar los efectos de la actividad física y la calidad de vida en el rendimiento académico de los estudiantes. Se utilizaron las bases de datos Web of Science, SCOPUS y PubMed para seleccionar los artículos publicados entre 2013 y 2023. Para la elaboración de la revisión sistemática se siguieron los criterios establecidos por la declaración Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), siendo la muestra final de 17 artículos. Los resultados muestran cómo la práctica regular de actividad física mejora el rendimiento académico en matemáticas y lengua. Además, también se observa que la calidad de vida juega un papel clave en el abandono o la disminución de la nota media de los alumnos en cualquier etapa educativa
Studying asphalt binder fatigue pattern by using a dynamic shear rheometer
This article was aimed at determining fatigue test results regarding different types of binder when using a dynamic shear rheometer (DSR). The tests were carried out in stress conditions at 20ºC. The stress input signal was a constant amplitude, 1.59 Hz frequency sine wave. Asphalt binders B-13/22, B-40/50, B-60/70, B-80/00, B-150/200 and BM-3c (modified asphalt) were studied. The test measured strain, complex modulus (G*), dissipated energy and dissipated energy ratio (DER) with the number of cycles. Strain criteria were used for determining binder fatigue failure (DER). Failure was defined as the point at which (DER) dropped 10% after peaking. Laws of asphalt fatigue were obtained from the strain and failure cycle results.El objetivo principal del artículo fue el de determinar el comportamiento a fatiga de diferentes tipos de asfaltos a partir de ensayos en el reómetro de corte dinámico (DSR). Los ensayos en el DSR se realizaron a un esfuerzo seno-soidal de amplitud constante, a una frecuencia de 1,59 Hz y a 20 ºC. Los asfaltos estudiados fueron B-13/22, B-40/50, B-60/70, B-80/00, B-150/200 y un BM-3c (as-falto modificado). Durante los ensayos se midió la evolu-ción de la deformación, el módulo complejo, el ángulo de desfase, la energía disipada y el ratio de energía disi-pada con los ciclos de carga, parámetros para determinar el ciclo de fallo por fatiga de los asfaltos. En primer lugar se estableció en las curvas de evolución de la defor-mación con los ciclos de carga el rango de deformación de rotura, zona donde la evolución de la deformación crece en forma súbita y se presenta el fallo por fatiga. Luego del análisis del ratio de energía disipada (DER) y de la evolución de la deformación con los ciclos de carga, se determinó el ciclo donde se produce el fallo. Del estudio se obtuvo un nuevo criterio de fallo de fatiga, consistente en calcular la fatiga del asfalto cuando alcanza un valor de 10% pasado el valor máximo de la curva de ratio de energía disipada. Por último, se obtuvieron las leyes de fatiga de los asfaltos con los resultados de deformación de rotura y ciclo de fallo
Impact of Physical Activity and Bio-Psycho-Social Factors on Social Network Addiction and Gender Differences in Spanish Undergraduate Education Students
Social network use has increased in recent years. Social networks are fast-changing and
may cause negative effects such as dependence and addiction. Hence, it was decided to establish
two research aims: (1) to identify the social network used by university students and their use levels
according to their sex and (2) to analyse how age, body mass index, physical activity, emotional
intelligence and social network type affect addiction to social networks according to young people’s
sex. A cross-sectional study was designed involving Spanish university students from Education
Degrees. The mean age of the participants was 20.84 years (±2.90). Females made up 69.8% of the
sample and males 30.2%. An online questionnaire was administered that included sociodemographic
questions, IPAQ-SF and TMMS-24. This study found that all students use WhatsApp and more than
97% have YouTube and Instagram accounts. The linear regression model obtained was as follows:
social network addiction = 3.355 + 0.336*emotional attention − 0.263*emotional clarity. There is a positive
relationship between social network addiction and emotional attention (r = 0.25; p < 0.001) and
negative relationships between social network addiction and emotional clarity (r = −0.16; p = 0.002)
and between social network addiction and age (r = −0.17; p = 0.001). University students report
lower levels of social network addiction and slightly higher levels of social network addiction among
females. In addition, there are significant differences between the average social network addiction
scores of university students in terms of their use of Telegram, TikTok and Twitch
Calidad en el sector financiero-banca del Perú
El sector financiero del Perú es crítico para el desarrollo económico nacional, ya que cumple con la función vital de traspasar fondos de las unidades superavitarias o ahorradoras a las unidades deficitarias. Sector del cual actualmente se desconoce su nivel de calidad, siendo esencial brindar servicios a clientes que cada año son más exigentes y mejor informados. En esto radica la importancia de esta investigación, que no solo permitió conocer cuál es el nivel de calidad que tienen las instituciones financieras del Perú, sino también identificar si existe diferencias significativas en el nivel de calidad entre las empresas del sector financiero que tienen un SGC con ISO 9001 y las que no cuentan con este estándar de calidad.
Se presenta una investigación con un alcance descriptivo y explicativo, y un enfoque cuantitativo, al buscar establecer si hay o no relación entre la variable independiente y la dependiente. Donde la calidad se está midiendo a través de nueve factores, que fueron definidos por Benzaquen (2013): (a) Alta Gerencia, (b) Planeamiento de la Calidad, (c) Auditoría y Evaluación de la Calidad, (d) Diseño de Productos, (e) Gestión de la Calidad de los Proveedores, (f) Control y Mejoramiento de Procesos, (g) Educación y Entrenamiento, (h) Círculos de Calidad y (i) Enfoque hacia la Satisfacción del Cliente.
Utilizando el cuestionario TQM se encuestó a una muestra de 185 agencias que pertenecen a 37 instituciones financieras, a partir de una población de 3,203 agencias, entre las que se incluye a la banca múltiple, las cajas municipales y las cajas rurales de ahorro. Se concluye que en este sector sí hay relación entre la implementación de las normas ISO 9001, como Sistema de Gestión de Calidad y el nivel obtenido en los nueve factores de éxito de la calidad. Pero dicha relación es negativa, ya que las empresas con SGC sin ISO 9001 obtuvieron un mejor desempeño. En términos generales, se encontró que la calidad del sector financiero es elevada y que probablemente esto se deba a que es un sector con procesos
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altamente estandarizado y muy supervisado por diversas entidades, donde se implementan diversos SGCThe Financial Sector of Peru is critical for national economic development as it meets the vital role of transferring funds or saving surplus to deficit units. Sector which currently its quality is unknown, being essential to provide services to clients each year are more demanding and better informed. Herein lies the importance of this research, which not only allowed to know what level of quality they have the financial institutions of Peru, but also identify whether there is a relationship between the implementation of the ISO 9001 standards and quality level.
An investigation of descriptive and explanatory approach is presented, to seek to establish whether there is relationship between an independent variable and a dependent. Where quality is being measured through nine factors, which were defined by Benzaquén (2013): (a) Senior Management, (b) Quality Planning, (c) Audit and Quality Assessment, (d) Design products, (e) Quality Management Providers (f) Control and Process Improvement, (g) Education and Training, (h) and Quality Circles (i) Approach to Customer Satisfaction.
The questionnaire TQM has been used to interview a sample of 185 agencies, in 37 financial institutions from a population of 3,203 offices including banks, as well as municipal or rural saving entities. Conclusions reveal that for these companies there is a negative relationship between the implementation of the ISO 9001 standards and the level on the nine success quality factors. It was also found that the quality in the financial sector is high and that this is probably due to it being a sector with highly standardized processes and highly supervised by various entities, which have implemented TQM through different systems.Tesi
Disrupción en el uso de la web 2.0 en los hoteles independientes
Las tecnologías de la Web 2.0 en ocasiones no se muestran nada claras, cuando se ha de demostrar como un mayor o menor uso de las redes sociales, afectará de forma negativa o positiva a la mejora de la reputación on-line. En esta ocasión, el estudio muestra un caso singular, donde un establecimiento de la ciudad de Sevilla, ha ocupado en los dos últimos años el puesto número uno en Tripadvisor, haciendo poco uso de esta redes sociales en la Web 2.0. Singular porque el uso que se hace de estas tecnologías para mantenerse en este primer puesto, no es siempre el más adecuado, y se produce a menudo un cierto nivel de disrupción, al romperse la línea de comunicación, y el ritmo de publicación.The Web 2.0 technologies is sometimes not at all clear, when you have to show as a greater or lesser use of social media, negative or positive affect on improving the way online reputation. This time, the study shows a unique case, where a property of the city of Seville, has occupied in the past two years the number one spot on Tripadvisor, making little use of this social networking on the Web 2.0. Singular that the use made of these technologies to stay in first place this is not always the most appropriate, and often produces a certain level of disruption, breaking the communication line, and the rate of publication
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