838 research outputs found
Eficiencia, competitividad y políticas de promoción empresarial. Estudio del sector agroalimentario en España.
En el plano internacional, la última década se está caracterizando por cambios importantes en el comercio internacional, que vienen determinados entre otras cosas, por, su rápida evolución (el crecimiento del comercio internacional dobla en los últimos años al del PIB), la internacionalización y diversificación del origen de la producción (de los 20 principales exportadores del mundo, cinco pertenecen al sudeste asiático) (1), el impulso técnico que se manifiesta en toda la cadena de valor, incluida la logística, y el rápido e intenso proceso de desregularización económica que se viene produciendo en los últimos cinco años
La Internacionalización de las cooperativas agroalimentarias. Necesidad y problemática.
El sector agroalimentario es de los pocos que están resistiéndose a la crisis sin ver frenado su crecimiento. Las cooperativas son el pilar del desarrollo de la producción y comercialización de productos agroalimentarios en España y en Europa. Si queremos que continúen actuando como motor del sector en nuestro país, estas deben desarrollarse hacia los mercados internacionales. Pero las cooperativas se enfrentan a carencias y problemas del entorno, internos y estratégicos que les restan competitividad y dificultan su expansión internacional. Diagnosticar estos problemas y apuntar líneas de actuación para superarlos, es el primer paso para el desarrollo internaciona
Thirty years of Political Science in Spain: professionalization, expansion and adjustment
The return of democracy to Spain in 1977 cleared the way for the institutional differentiation and launch of the discipline in the country. However, this double process did not actually crystallize until the mid 1980’s, when the “Political Science and Public Administration” was approved by the government as a separate field of knowledge. This article intends to provide an account of the most relevant milestones that took place since then until the last few years of the 20th century, when full institutionalization of the discipline was reached with the publication of the first issue of this Journal. Moreover, the article systematizes a comprehensive set of data on students, faculty staff, teaching and research structures, scientific congresses, etc., with an aim at offering a balance of the main events and changes experienced by the discipline and the profession during their consolidation phase in the 21st century. The developments covered here have contributed to the evolution from the initial amateurism to the professionalization of scholars dedicated to this social science, which has gained full recognition in the academic sphere both nationally and internationally, even if it still suffers from a lack of legitimacy concerning the specificity of its subject vis-à-vis other social sciences.</p
Green extraction of antioxidant compounds from olive tree leaves based on naturaldeep eutectic solvents
Agri-food industries generate a large amount of waste that offers great revalorization opportunities within the circular economy framework. In recent years, new methodologies for the extraction of compounds with more eco-friendly solvents have been developed, such as the case of natural deep eutectic solvents (NADES). In this study, a methodology for extracting phenolic compounds from olive tree leaves using NADES has been optimized. The conditions established as the optimal rely on a solvent composed of choline chloride and glycerol at a molar ratio of 1:5 with 30% water. The extraction was carried out at 80 °C for 2 h with constant agitation. The extracts obtained have been analyzed by high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) in MRM mode. The comparison with conventional ethanol/water extraction has shown that NADES, a more environmentally friendly alternative, has improved extraction efficiency. The main polyphenols identified in the NADES extract were Luteolin-7-O-glucoside, Oleuropein, 3-Hydroxytyrosol, Rutin, and Luteolin at the concentrations of 262, 173, 129, 34, and 29 mg kg−1 fresh weight, respectively
Impact of Nutrition on Pulmonary Arterial Hypertension
Pulmonary arterial hypertension (PAH) is characterized by sustained vasoconstriction, vascular remodeling, inflammation, and in situ thrombosis. Although there have been important advances in the knowledge of the pathophysiology of PAH, it remains a debilitating, limiting, and rapidly progressive disease. Vitamin D and iron deficiency are worldwide health problems of pandemic proportions. Notably, these nutritional alterations are largely more prevalent in PAH patients than in the general population and there are several pieces of evidence suggesting that they may trigger or aggravate disease progression. There are also several case reports associating scurvy, due to severe vitamin C deficiency, with PAH. Flavonoids such as quercetin, isoflavonoids such as genistein, and other dietary polyphenols including resveratrol slow the progression of the disease in animal models of PAH. Finally, the role of the gut microbiota and its interplay with the diet, host immune system, and energy metabolism is emerging in multiple cardiovascular diseases. The alteration of the gut microbiota has also been reported in animal models of PAH. It is thus possible that in the near future interventions targeting the nutritional status and the gut dysbiosis will improve the outcome of these patients
Experimental and Theoretical Brownian Dynamics Analysis of Ion Transport During Cellular Electroporation of E. coli Bacteria
Escherichia coli bacterium is a rod-shaped organism composed of a complex
double membrane structure. Knowledge of electric field driven ion transport
through both membranes and the evolution of their induced permeabilization has
important applications in biomedical engineering, delivery of genes and
antibacterial agents. However, few studies have been conducted on Gram-negative
bacteria in this regard considering the contribution of all ion types. To
address this gap in knowledge, we have developed a deterministic and stochastic
Brownian dynamics model to simulate in 3D space the motion of ions through
pores formed in the plasma membranes of E. coli cells during electroporation.
The diffusion coefficient, mobility, and translation time of Ca,
Mg, Na, K, and Cl ions within the pore region are estimated
from the numerical model. Calculations of pore's conductance have been
validated with experiments conducted at Gustave Roussy. From the simulations,
it was found that the main driving force of ionic uptake during the pulse is
the one due to the externally applied electric field. The results from this
work provide a better understanding of ion transport during electroporation,
aiding in the design of electrical pulses for maximizing ion throughput,
primarily for application in cancer treatment.Comment: Annals of Biomedical Engineering, 202
Relación entre la aptitud cardiorrespiratoria y el rendimiento en inglés como lengua extranjera
The aim of the present study was to examine the relationship between cardiorespiratory fitness and foreign language score, among primary and secondary education
students in a group of 223 students (111 of primary school and 122 of secondary school)
from Baleares region, Spain, aged between 9 and 16 years old that participated in the study.
A statistical regression analysis was carried out for the comparison of the two variables
(cardiorespiratory fitness and English subject score) in primary and secondary education.
Physical fitness was assessed using the 6-minute walk test (6MWT) and the values obtained
were shown in VO2max. English subject scores were collected at the end of the year prior to
the test. The results obtained did not reveal any correlation between VO2max and final English
score in primary school (r=.04, p=.65). However, dataset revealed a positive small correlation between VO2max and final English score in secondary school (r=.26, p=.01). These
findings suggest that while physical activity may have some positive effect on final score, the
relationship is complex and may be influenced by various other factors. Further research is
needed to better understand the relationship between physical activity and learning, as well
as the potential moderating factors involved.El objetivo del presente estudio fue el de examinar la relación existente entre la aptitud cardiorrespiratoria y el aprendizaje del inglés como lengua extranjera entre
los estudiantes de educación primaria y secundaria en un grupo de 223 estudiantes (111
estudiantes de educación primaria y 112 estudiantes de educación secundaria) de la región
de Baleares, España, con edades comprendidas entre los 9 y los 15 años participaron en el
presente estudio. Se llevó a cabo un análisis estadístico de regresión para la comparación
de las dos variables (aptitud cardiorrespiratoria y puntuación en la asignatura de inglés) en
educación primaria y educación secundaria. La aptitud física se evaluó mediante la prueba
de caminata de 6 minutos (6MWT) y los valores obtenidos se mostraron en VO2max. Las
notas de la asignatura de inglés se recogieron al acabar el curso anterior a la realización de
la prueba. Los resultados obtenidos no revelaron ninguna correlación entre el VO2max y la
puntuación final de inglés en educación primaria. Sin embargo, el conjunto de datos reveló una pequeña y positiva correlación entre el VO2max y la puntuación final en inglés educación
secundaria. Estos hallazgos sugieren, si bien la actividad física puede tener algún efecto
positivo en el rendimiento académico, la relación es compleja y puede estar influenciada
por diversos factores. Por todo ello, se necesita más investigación para comprender mejor
la relación entre la actividad física el rendimiento académico, así como los posibles factores
moderadores involucrados
Utilizando ARMSim y QtARMSim para la docencia de Arquitectura de Computadores
Muchos de los objetivos formativos de las asignaturas de introducción a la Arquitectura de Computadores se centran en aquellos
aspectos que conforman la visión que un programador en lenguaje ensamblador tiene de un computador. Por regla general, para
definir dichos objetivos se suele utilizar una arquitectura de computador concreta, que normalmente se selecciona con el doble
criterio de que sea lo más sencilla posible y, a la vez, motive al estudiantado.
La arquitectura ARM es una candidata idónea como vehículo conductor en la docencia de Arquitectura de Computadores.
Por un lado, al estar basada en la arquitectura RISC (Reduced Instruction Set Computer), es relativamente sencilla. Por otro, se
trata de una arquitectura actual y ampliamente difundida (especialmente en dispositivos móviles, smartphones y tabletas), lo que
motiva al estudiantado.
Para poder realizar prácticas sobre ARM es conveniente disponer de un simulador o de una herramienta de desarrollo sobre
una máquina ARM. Puesto que dicha materia se explica en los primeros cursos, conviene que la aplicación seleccionada sea
sencilla de utilizar y lo suficientemente flexible. Por otro lado, conviene que sea software libre, para poder adaptarla en caso
necesario, y también multiplataforma y gratuita, para facilitar que el estudiante que lo desee pueda instalarla en su propio equipo.
Tras evaluar distintas opciones, finalmente se optó por desarrollar y liberar un simulador propio de ARM, ARMSim, y una interfaz
gráfica para dicho simulador, QtARMSim.
El motor de simulación, ARMSim, y su interfaz, QtARMSim, han sido utilizados durante el curso 2014–15. Las críticas
recibidas, tanto por los estudiantes como por los profesores de laboratorio, han sido muy positivas.Many of the training objectives of the Introduction to Computer Architecture modules focus on those aspects that conform the vision that an assembly language programmer has about a computer. As a rule, in order to define those objectives a concrete computer architecture is used following the following criteria: simplicity
and ability to motivate students.
ARM architecture is an ideal candidate for the didactics of Computer Architecture. On the one hand, being based on RISC architecture (Reduced Instruction Set Computer) it is rather simple. On the other, it is widely spread contemporary architecture (especially in mobile phones, smartphones and tablets), something that motivates students.
In order to carry out ARM practice it would be convenient to have a simulator or a development tool on an ARM machine. Given the fact that this module is taught during the first academic years, it would also be convenient that the application selected was easy to use and flexible enough. Besides, it would be a good idea that it used freeware in order to be adapted if necessary, besides being free of charge
and cross-platform-based so the students may install it in their own computers.
After assessing several options, an ARM simulator (ARMSim) as well as a graphic interface for the latter (QtARMSim) were finally developed.
The simulation engine, ARMSim, as well as its interface, QtARMSim, were used during the 2014/2015 academic year. The feedback received from both the students and lab lecturers have been remarkably positive
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