2,250 research outputs found
Las redes sociales como herramienta de análisis estructural input-output
Uno de los aspectos fundamentales que posibilita el conocimiento en profundidad de una economía es la realización de un análisis de su estructura productiva. Dicho análisis supone una importante ayuda no sólo en la toma de decisiones de política económica, sino también constituye un requisito indispensable y previo a las tareas de predicción necesarias en un contexto empresarial. El estudio de una economía puede abordarse desde muy diversas ópticas, una de las cuales es el enfoque input-output, el cual permite analizar conjuntamente las relaciones intersectoriales de una economía y su demanda agregada, con lo cual se dispone de un conocimiento integrado de la actividad económica. Consideramos la teoría de redes como una importante "herramienta", a nuestro juicio poco explotada en el ámbito económico, que constituye un marco general de estudio dentro del cual podemos encuadrar el análisis input-output. Esta teoría permite simplificar el esquema de relaciones surgido entre los sectores de una economía y, por lo tanto, favorecer la comprensión del mismo. El objetivo del presente trabajo es analizar las relaciones interindustriales bajo la óptica de la teoría de las redes sociales y, al mismo tiempo, efectuar una comparación entre los resultados así obtenidos y los que se derivan de la aplicación de los métodos inputoutput clásicos
Decision making and erotic stimuli: An evolutionary perspective
Exposing individuals to erotic stimuli modifies perceived time horizons, causing subjects to assign greater value to the present than the future. This can be explained by different models, including the theory of visceral factors and evolutionary psychology. Specifically, evolutionary theory analyses the latest reasons as explanatory variables of this behaviour. An evolutionary perspective was used to perform two experiments where individuals were exposed to pictures containing erotic stimuli. The first experiment, in which both men and women took part, shows that the influence of such stimuli on risk perception is different in the two sexes. The second experiment, in which only women took part, shows that female risk perception varies according to the subject's aims in a relationship
Effect of the initial conditions on a one-dimensional model of small-amplitude wave propagation in shallow water: II: Blowup for nonsmooth conditions.
Abstract Purpose – The purpose of this paper is to analyze numerically the blowup in finite time of the solutions to a one-dimensional, bidirectional, nonlinear wave model equation for the propagation of small-amplitude waves in shallow water, as a function of the relaxation time, linear and nonlinear drift, power of the nonlinear advection flux, viscosity coefficient, viscous attenuation, and amplitude, smoothness and width of three types of initial conditions. Design/methodology/approach – An implicit, first-order accurate in time, finite difference method valid for semipositive relaxation times has been used to solve the equation in a truncated domain for three different initial conditions, a first-order time derivative initially equal to zero and several constant wave speeds. Findings – The numerical experiments show a very rapid transient from the initial conditions to the formation of a leading propagating wave, whose duration depends strongly on the shape, amplitude and width of the initial data as well as on the coefficients of the bidirectional equation. The blowup times for the triangular conditions have been found to be larger than those for the Gaussian ones, and the latter are larger than those for rectangular conditions, thus indicating that the blowup time decreases as the smoothness of the initial conditions decreases. The blowup time has also been found to decrease as the relaxation time, degree of nonlinearity, linear drift coefficient and amplitude of the initial conditions are increased, and as the width of the initial condition is decreased, but it increases as the viscosity coefficient is increased. No blowup has been observed for relaxation times smaller than one-hundredth, viscosity coefficients larger than ten-thousandths, quadratic and cubic nonlinearities, and initial Gaussian, triangular and rectangular conditions of unity amplitude.Funding for open access charge: Universidad de Málaga / CBU
Influence of Emotional Intelligence, Motivation and Resilience on Academic Performance and the Adoption of Healthy Lifestyle Habits among Adolescents
Included among the basic objectives of Physical Education (PE) classes is the consolidation of habits of a healthy lifestyle among adolescents. However, the main studies in this field have focused on cognitive aspects related to students during these classes, yet they ignore the role that emotions can play in the adoption of future habits. Objectives: To analyze how emotions (emotional intelligence and emotional state) can influence the resilience and motivation of adolescents, as well as academic performance and adoption of healthy lifestyle habits. Methodology: 615 secondary school students between the ages of 14 and 19 participated (M = 16.02; SD = 1.57) in the study. A structural equations model was developed using the main variables and by applying some of the principles of Self-Determination Theory. The results show that emotional intelligence is positively related to positive emotions and negatively related to negative emotions. Positive emotions positively predict both self-motivation towards physical education classes and resilience. Resilience positively predicts self-motivation. Finally, self-motivation acts as a predictor of both academic performance and regular participation in physical activity. Conclusions: This study successfully shows the importance of focusing on emotions in PE classes inasmuch as emotion increases the tendency to get good grades and maintain active lifestyle habits. In this sense, focusing on the emotions of students in PE could prove quite beneficial
Propuesta del diseño de un manual de control interno contable del área de Inventario en la empresa SUMIDENTAL S.A., ubicada en el municipio de Jinotepe, departamento de Carazo durante el II semestre del año 2016
El presente informe consiste en la búsqueda, reconocimiento, descripción, análisis y evaluación de la situación actual en la que se encuentra la empresa SUMIDENTAL S.A. en cuanto a controles internos se refiere, con el objetivo de elaborar propuesta de manual de control interno del área de inventario, que constituya una herramienta eficaz a nivel contable para identificar las debilidades que el sistema de control interno de inventario.
La propuesta de manual de control interno aplicado al área de inventario sugerida en este estudio, surge como resultado de hallazgos identificados en el proceso de análisis que se realizó a la empresa y que servirá de fuente generadora de información oportuna, veraz, confiable que proporcione elementos de apoyo a la gerencia en el proceso toma de decisiones.
Durante el estudio se identificaron, interpretaron, clasificaron, analizaron y evaluaron todos los aspectos que componen el sistema de control interno de la empresa actualmente, en específico, aquellos que tiene que ver con la sección de inventario de la misma y de esta manera fortalecer los controles que se consideran débiles, o crear los inexistentes. Dicho análisis será de suma ayuda a la empresa para el diseño de un nuevo o bien el fortalecimiento del mismo, el cual podría ser extensivo a otras áreas de la misma.
El sistema de control interno aparte de ser una política de gerencia, se constituye como una herramienta esencial para la empresa SUMIDENTAL S.A., y de esta manera pueda modernizarse, cambiar y producir los mejores resultados, con calidad y eficiencia
Characterization of terrestrial hot particles from the Palomares accident using destructive and non-destructive analytical techniques
Several radioactive particles from the Palomares area have been analyzed with the nuclearmicroprobe of the National Accelerator Centre (CNA) in Seville exploring the advantages of combining -PIXE using a 5.5 MeV4He beam with conventional -PIXE analysis using 3 MeV protons. Themeasurements performed with the -particles are more sensitive to the sample surface, while the resultscollected with protons are indicative of the average composition of the hot particle. In this way, importantinformation about the depth distribution of Pu and U in the particles has been obtained. In addition, theparticles have been analyzed by SEM (EDX) and one of them has been sacrificed for the determinationof its U and Pu isotopic composition by ICP-MS and -spectrometry, being gained in this way importantinformation about the composition of the weapons involved in the Palomares accident.Junta de Andalucía Excellence Project TU-DRAMA (Ultra-sensitive techniques for radionuclides determination in environmental materials
Amyloid beta and diabetic pathology cooperatively stimulate cytokine expression in an Alzheimer's mouse model
Background Diabetes is a risk factor for developing Alzheimer's disease (AD); however, the mechanism by which diabetes can promote AD pathology remains unknown. Diabetes results in diverse molecular changes in the brain, including dysregulation of glucose metabolism and loss of cerebrovascular homeostasis. Although these changes have been associated with increased A beta pathology and increased expression of glial activation markers in APPswe/PS1dE9 (APP/PS1) mice, there has been limited characterization, to date, of the neuroinflammatory changes associated with diabetic conditions. Methods To more fully elucidate neuroinflammatory changes associated with diabetes that may drive AD pathology, we combined the APP/PS1 mouse model with either high-fat diet (HFD, a model of pre-diabetes), the genetic db/db model of type 2 diabetes, or the streptozotocin (STZ) model of type 1 diabetes. We then used a multiplexed immunoassay to quantify cortical changes in cytokine proteins. Results Our analysis revealed that pathology associated with either db/db, HFD, or STZ models yielded upregulation of a broad profile of cytokines, including chemokines (e.g., MIP-1 alpha, MIP-1 beta, and MCP-1) and pro-inflammatory cytokines, including IL-1 alpha, IFN-gamma, and IL-3. Moreover, multivariate partial least squares regression analysis showed that combined diabetic-APP/PS1 models yielded cooperatively enhanced expression of the cytokine profile associated with each diabetic model alone. Finally, in APP/PS1xdb/db mice, we found that circulating levels of A beta 1-40, A beta 1-42, glucose, and insulin all correlated with cytokine expression in the brain, suggesting a strong relationship between peripheral changes and brain pathology. Conclusions Altogether, our multiplexed analysis of cytokines shows that Alzheimer's and diabetic pathologies cooperate to enhance profiles of cytokines reported to be involved in both diseases. Moreover, since many of the identified cytokines promote neuronal injury, A beta and tau pathology, and breakdown of the blood-brain barrier, our data suggest that neuroinflammation may mediate the effects of diabetes on AD pathogenesis. Therefore, strategies targeting neuroinflammatory signaling, as well as metabolic control, may provide a promising strategy for intervening in the development of diabetes-associated AD
Hallmarks of Cancer Expression in Oral Lichen Planus: A Scoping Review of Systematic Reviews and Meta-Analyses
Oral lichen planus (OLP) is a common chronic inflammatory disease of unknown etiology
and likely autoimmune nature that is currently considered an oral potentially malignant disorder,
implying that patients suffering from this process are at risk of developing oral cancer in their
lifetime. The molecular alterations that develop in OLP and that make the affected oral epithelium
predisposed to malignancy are unknown, although, as in other autoimmune diseases (ulcerative
colitis, primary biliary cirrhosis, etc.), they may be linked to oncogenesis-promoting effects mediated
by the inflammatory infiltrate. So far there is no in-depth knowledge on how these hallmarks of
cancer are established in the cells of the oral epithelium affected by OLP. In this scoping review of
systematic reviews and meta-analyses the state of evidence based knowledge in this field is presented,
to point out gaps of evidence and to indicate future lines of research. MEDLINE, Embase, Cochrane
Library and Dare were searched for secondary-level studies published before October 2022. The
results identified 20 systematic reviews and meta-analyses critically appraising the hallmarks tumorpromoting
inflammation (n = 17, 85%), sustaining proliferative signaling (n = 2, 10%), and evading
growth suppressors (n = 1, 5%). No evidence was found for the other hallmarks of cancer in OLP.
In conclusion, OLP malignization hypothetically derives from the aggressions of the inflammatory
infiltrate and a particular type of epithelial response based on increased epithelial proliferation,
evasion of growth-suppressive signals and lack of apoptosis. Future evidence-based research is
required to support this hypothesis
Classification of Various Marijuana Varieties by Raman Microscopy and Chemometrics
Fernando Ortega Ojeda desarrolló el procedimiento de tratamiento estadístico de datos y supervisó los cálculos multivariantes en The Unscrambler y SIMCA. The Raman analysis of marijuana is challenging because of the sample's easy photo-degradation caused by the laser intensity. In this study, optimization of collection parameters and laser focusing on marijuana trichome heads allowed collecting Raman spectra without damaging the samples. The Raman spectra of Delta9-tetrahydrocannabinol (THC), cannabidiol (CBD), and cannabinol (CBN) standard cannabinoids were compared with Raman spectra of five different types of marijuana: four Sativa varieties (Amnesia Haze, Amnesia Hy-Pro, Original Amnesia, and Y Griega) and one Indica variety (Black Domina). The results verified the presence of several common spectral bands that are useful for marijuana characterization. Results were corroborated by the quantum chemical simulated Raman spectra of their acid-form (tetrahydrocannabinol acid (THCA), cannabidiol acid (CBDA)) and decarboxylated cannabinoids (THC, CBD, and CBN). A chemometrics-assisted method based on Raman microscopy and OPLS-DA offered good classification among the different marijuana varieties allowing identification of the most significant spectral bands.Instituto Universitario de Investigación en Ciencias Policiales (IUICP), Universidad de Alcalá (UAH)
Iguales, familia y participación en actividades deportivas organizadas durante la adolescencia
Suplemento de artículos seleccionados con revisión del Congreso Andaluz de Psicología de la Actividad Física y el Deporte (13 : 2011 : Sevilla). Editores : José Carlos Caracuel ; Rocío Bohórquez.This study aimed to examine the influence of sport activities by peer groups and the family on the frequency of adolescents' participation in organized sport activities. A sample of 9,821 Spanish adolescent schoolchildren between the ages of 11 and 18 from the 2010 edition of the international study on Health Behaviour in School-Aged Children (HBSC) was used. The results obtained by means of an Answer Tree multivariate analysis indicated that gender was the best predictor of organized sport activity, with participation being notably higher in boys. As for the role of other variables, the practice of sport in peer and family activities were the most influential variables for boys. On the contrary, in the girls' case, age appeared as the first factor and the influence of sport in family activities and the peer group was different depending on age. In conclusion, family and peers seem to be significant influences on involvement in sport, despite having different roles according to the adolescents' gender and age
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