On thin-shell wormholes evolving in flat FRW spacetimes

We analize the stability of a class of thin-shell wormholes with spherical symmetry evolving in flat FRW spacetimes. The wormholes considered here are supported at the throat by a perfect fluid with equation of state $\mathcal{P}=w\sigma$ and have a physical radius equal to $aR$, where $a$ is a time-dependent function describing the dynamics of the throat and $R$ is the background scale factor. The study of wormhole stability is done by means of the stability analysis of dynamic systems.Comment: 8 pages; to appear in MPL

Differences in trajectories and predictive factors of cognition over time in a sample of cognitively healthy adults, in zaragoza, spain

Great inter-individual variability has been reported in the maintenance of cognitive function in aging. We examined this heterogeneity by modeling cognitive trajectories in a population-based longitudinal study of adults aged 55+ years. We hypothesized that (1) distinct classes of cognitive trajectories would be found, and (2) between-class differences in associated factors would be ob-served. The sample comprised 2403 cognitively healthy individuals from the Zaragoza Dementia and Depression (ZARADEMP) project, who had at least three measurements of the Mini-Mental State Examination (MMSE) in a 12-year follow-up. Longitudinal changes in cognitive functioning were modeled using growth mixture models (GMM) in the data. The best-fitting age-adjusted model showed 3 distinct trajectories, with 1-high-to-moderate (21.2% of participants), 2-moderate-stable (67.5%) and, 3-low-and-declining (9.9%) cognitive function over time, respectively. Compared with the reference 2-trajectory, the association of education and depression was significantly different in trajectories 1 and 3. Instrumental activities of daily living (iADLs) were only associated with the declining trajectory. This suggests that intervention strategies should be tailored specifically to individuals with different trajectories of cognitive aging, and intervention strategies designed to maintain cognitive function might be different from those to prevent decline. A stable cognitive performance (‘successful cognitive aging’) rather than a mild decline, might be more ‘normal’ than generally expected

Desigualdad salarial y crecimiento económico en las regiones de México

Only a few studies have analysed the relationship between intraregional inequality and growth, although several studies have measured inequality at the regional level. The objective of this paper is to analyse the relationship between income (wage) inequality and economic growth in different regions of Mexico. We also try to identify factors that explain the variation of intra-regional inequality across Mexican regions and over time. Using macroeconomic databases and publicly available microdata, we apply techniques used in the fields of statistics and econometrics to obtain robust evidence on the relationship between growth and inequality. Our aim is to provide policy recommendations to support the design and implementation of growth-promoting measures thatavoid the exclusion of certain social groups. This paper provides reasons to use a spatial approach and an analysis of particular regions to avoid «one size fits all» policy recommendations.Sólo unos pocos estudios han analizado la relación entre la desigualdad intra-regional y el crecimiento, a pesar de que varios estudios han medido la desigualdad a nivel regional. El objetivo de este trabajo es analizar la relación entre la desigualdad del ingreso (salario) y el crecimiento económico en diferentes regiones de México. También tratamos de identificar los factores que explican la variación de la desigualdad intra-regional a lo largo del tiempo. Para ello, se utilizan bases de datos macroeconómicos y de microdatos a disposición del público y aplicamos técnicas estadísticas y econométricas para obtener evidencia robusta sobre la relación entre crecimiento y desigualdad. Nuestro objetivo es intentar ofrecer recomendaciones de política para apoyar el diseño y la implementación de medidas que promuevan el crecimiento y que eviten así la exclusión de ciertos grupos sociales. El artículo ofrece motivos para utilizar un enfoque espacial y el análisis de determinadas regiones para evitar recomendaciones de política del tipo «one size fits all»

Letter from Professor Lobo

It is my great pleasure to welcome you to the inaugural issue of TheAnnual Review of Criminal Justice Studies. As the faculty advisorof this undergraduate journal, I am proud to present the exceptionalwork of our contributors and the critical perspectives they bring tothe field of criminal justice studies

Web localization: The Spanish SMEs as case of study

Constant changes in the economic environment, where globalization and the development of the knowledge economy act as drivers, are systematically pushing companies towards the challenge of accessing external markets. Web localization constitutes a new field of study and professional intervention. From the translation perspective, localization equates to the website being adjusted to the typological, discursive and genre conventions of the target culture, adapting that website to a different language and culture. This entails much more than simply translating the content of the pages. The content of a webpage is made up of text, images and other multimedia elements, all of which have to be translated and subjected to cultural adaptation. A case study has been carried out to analyze the current presence of localization within Spanish SMEs from the chemical sector. Two types of indicator have been established for evaluating the sample: indicators for evaluating company websites (with a Likert scale from 0-4) and indicators for evaluating web localization (0-2 scale). The results show overall website quality is acceptable (2.5 points out of 4). The higher rating has been obtained by the system quality (with 2.9), followed by information quality (2.7 points) and, lastly, service quality (1.9 points). In the web localization evaluation, the contact information aspects obtain 1.4 points, the visual aspect 1.04, and the navigation aspect was the worse considered (0.37). These types of analysis facilitate the establishment of practical recommendations aimed at SMEs in order to increase their international presence through the localization of their websites.The authors are grateful to the Spanish "Ministry of Science and Innovation" for supporting this study, in the framework of the research Project CSO2015-64532-R, partially funded by the FEDER program of the European Union

Changes in Wage Structure in Mexico Going Beyond the Mean : An Analysis of Differences in Distribution, 1987-2008

This paper conducts an empirical analysis of the relationship between wage inequality, employment structure, and returns to education in urban areas of Mexico during the past two decades (1987-2008). Applying Melly’s (2005) quantile regression based decomposition, we find that changes in wage inequality have been driven mainly by variations in educational wage premia. Additionally, we find that changes in employment structure, including occupation and firm size, have played a vital role

Using Neural Networks to Simulate the Alzheimer's Disease

Making use of biologically plausible artificial neural networks that implement Grossberg’s presynaptic learning rule, we simulate the possible effects of calcium dysregulation in the neuron’s activation function, to represent the most accepted model of Alzheimer's Disease: the calcium dysregulation hypothesis. According to Cudmore and Turrigiano calcium dysregulation alters the shifting dynamic of the neuron’s activation function (intrinsic plasticity). We propose that this alteration might affect the stability of synaptic weights in which memories are stored. The results of the simulation supported the theoretical hypothesis, implying that the emergence of Alzheimer's disease's symptoms such as memory loss and learning problems might be correlated to intrinsic neuronal plasticity impairment due to calcium dysregulation

Clinically significant anxiety as a risk factor for dementia in the elderly community

Objective: To evaluate whether clinically significant anxiety is an independent risk factor for dementia, taking into account both depression among potentially confounding factors and the competing risk of death. Method: During the Zaragoza Dementia and Depression (ZARADEMP) study, a random sample of community dwellers aged 55 years or older was assessed (n = 4803), and a two-wave, 4.5-year follow-up was completed. Geriatric Mental State (GMS)-AGECAT criteria were used to diagnose anxiety and DSM-IV criteria were applied to diagnose incident dementia. The multivariate Fine and Gray regression model was implemented to calculate dementia risk. Results: Compared with non-cases (GMS-AGECAT criteria), the incidence rate of dementia was significantly higher in subcases of anxiety, and particularly significant in the cases of anxiety (incidence rate ratio (IRR): 2.77; P = 0.010). Cases of anxiety, but not subcases, at baseline were significantly associated with dementia risk (adjusted subdistribution hazard ratio (SHR): 2.7; P = 0.019). Conclusion: Clinically significant anxiety is associated with an almost threefold increase in the risk of dementia in the population, even when controlling for depression and considering mortality in the competing risks model

Clinically relevant anxiety and risk of Alzheimer's disease in an elderly community sample: 4.5 years of follow-up.

Objectives: To investigate whether clinically relevant anxiety increased the risk for developing Alzheimer''s disease (AD) while controlling for the presence of depression and other confounders; and to report the population attributable fraction (PAF) associated with anxiety disorder. Method: We used data from the longitudinal, community-based Zaragoza Dementia and Depression (ZARADEMP) study. A random sample of 4057 dementia-free community dwellers aged =55 years were followed for 4.5 years. The Geriatric Mental State-Automated Geriatric Examination for Computer Assisted Taxonomy package was used for the diagnosis of clinically significant cases and subcases of anxiety; and AD was diagnosed by a panel of research psychiatrists according to DSM-IV criteria. Multivariate survival analysis with competing risk regression model was performed. Results: We observed a significant association between anxiety cases at baseline and AD risk in the univariate analysis that persisted in the fully adjusted model (SHR: 3.90; 95% CI: 1.59–9.60; p = 0.003), with a PAF for AD of 6.11% (95% CI: 1.30%–16.17%). No significant association between ‘subcases’ of anxiety at baseline and AD risk was found. Limitations: Data on apolipoprotein E were not available. The hospital-based diagnosis was not completed in all cases of dementia. Conclusion: Late-life, clinically significant anxiety (but not subclinical anxiety) seems to increase the risk of AD, independently of the effect of several confounders, including depression. Taking into account the high prevalence of anxiety among the elderly, future studies are warranted to determine potential risk reduction of AD

Dry batch anaerobic digestion of food waste in a box-type reactor system: Inoculum preparation and reactor performance

A box-type reactor system with liquid inoculum has been studied for the dry anaerobic digestion of foodwaste. The food waste was processed without any pre-treatment to remove physical impurities, neitherwater addition to dilute and slurry the feedstock. The experiment was carried out with inoculum tosubstrate ratios of 1:1 (w/w) and 0.08:1 (VS basis). Previous acclimation of liquid inoculum enhanced theprocess, assuring a fast start up of the box digester and preventing from process failure by volatile fattyacids accumulation. The percolate recirculation strategy was shown to have a relevant effect on theprogress of the process. The results suggest that the process can be optimized by providing low percolaterecirculation rate during the start-up of the box digester followed by an increase in the percolaterecirculation rate when volatile fatty acids decrease and methane content in the biogas increases. Themethane yield obtained in the box digester from the food waste was in the range 460e477 L CH4kg 1VS,being the VS removal efficiency between 91.1 and 91.4%. Globally, the process operated at an organicloading rate of 2.5 kg VS m 3d 1and yielded a volumetric methane production rate of 1.0 m3CH4m3d 1. These results show the high potential of food waste for its conversion in renewable energy by usingthe dry batch anaerobic technology