On the coupling of vector fields to the Gauss-Bonnet invariant

Inflationary models including vector fields have attracted a great deal of attention over the past decade. Such an interest owes to the fact that they might contribute to, or even be fully responsible for, the curvature perturbation imprinted in the CMB. However, the necessary breaking of the vector field's conformal invariance during inflation is not without problems. In recent years it has been realized that a number of instabilities endangering the consistency of the theory arise when the conformal invariance is broken by means of a non-minimal coupling to gravity. In this paper we consider a massive vector field non-minimally coupled to gravity through the Gauss-Bonnet invariant, and investigate whether the vector can obtain a nearly scale-invariant perturbation spectrum while evading the emergence of perturbative instabilities. We find that the strength of the coupling must be extremely small if the vector field is to have a chance to contribute to the total curvature perturbation.Comment: 8 pages, 1 figur

Behavior of early warnings near the critical temperature in the two-dimensional Ising model

Among the properties that are common to complex systems, the presence of critical thresholds in the dynamics of the system is one of the most important. Recently, there has been interest in the universalities that occur in the behavior of systems near critical points. These universal properties make it possible to estimate how far a system is from a critical threshold. Several early-warning signals have been reported in time series representing systems near catastrophic shifts. The proper understanding of these early-warnings may allow the prediction and perhaps control of these dramatic shifts in a wide variety of systems. In this paper we analyze this universal behavior for a system that is a paradigm of phase transitions, the Ising model. We study the behavior of the early-warning signals and the way the temporal correlations of the system increase when the system is near the critical point.Comment: 20 pages, 8 figures, Submitted to PLOS ONE on Oct. 20th 2014. PONE-D-14-4718

Quantification of Irregular Rhythms in Chronobiology: A Time- Series Perspective

In optimal conditions of youth and health, most—if not all—physiological systems obey regular circadian rhythms in response to the periodic day-night cycle and can be well described by standard techniques such as cosinor analysis. Adverse conditions can disturb the regularity and amplitude of circadian cycles, and, recently, there is interest in the field of chronobiology to quantify irregularities in the circadian rhythm as a means to track underlying pathologies. Alterations in physiological rhythms over a wide range of frequency scales may give additional information on health conditions but are often not considered in traditional analyses. Wavelets have been introduced to decompose physiological time series in components of different frequencies and can quantify irregular patterns, but the results may depend on the choice of the mother wavelet basis which is arbitrary. An alternative approach are recent data-adaptive time-series decomposition techniques, such as singular spectrum analysis (SSA), where the basis functions are generated by the data itself and are user-independent. In the present contribution, we compare wavelets and SSA analysis for the quantification of irregular rhythms at different frequency scales and discuss their respective advantages and disadvantages for application in chronobiology

Aportes de la Geologia e Ingenieria a la recuperación de areas afectadas por carcavamiento.

El trabajo se realizo en el sitio arqueológico Shincal de Quimivil, (Londres - Belén, Catamarca). El clima es árido continental, las precipitaciones irregulares, violentas y torrenciales, generan un ámbito propicio para una fuerte actividad hídrica. La erosión hídrica superficial se manifiesta desde surcos de canalización de la escorrentía, hasta cárcavas de importantes dimensiones que afectan las estructuras del sitio. Otro factor importante es la presencia de ctenomys, puesto que sus cuevas ofrecen una vía de infiltración y escurrimiento hídrico subsuperficial. Se han reconocido y cartografiado cinco cárcavas y tres vías principales de escurrimiento superficial que alimentan las cárcavas exacerbando la erosión retrocederte en las cabeceras.\ud Durante este trabajo se realizo reconocimiento de campo; relevamiento geomorfológico del área, relevamiento planialtimétrico del Sitio, del conjunto de cárcavas, de cada cárcava presente y de vías principales de escurrimiento superficial.\ud Se elaboro la cartografía temática, el análisis estadístico de datos y la vinculación de los datos numéricos, cartográficos y bibliográficos, en base a lo cual, se efectuó el análisis y propuesta de estrategias de corrección y control de las cárcavas que afectan las estructuras combinando obras hidráulicas, estructuras mecánicas y repoblación vegetal con especies autóctonas

Colonial Organization of Mine Labour in Charcas 1 (Present-Day Bolivia) and Its Consequences 2 (Sixteenth to the Seventeenth Centuries)

This article analyses the changes in the organization of labour during the sixteenth and seventeenth centuries in colonial Charcas, present-day Bolivia, focusing on the role that different colonial authorities played in this process and its consequences. The Spanish took advantage of the pre-Hispanic organization of labour from the beginning of their conquest. However, in a colonial context, labour relations changed significantly, and the architect of those alterations was Viceroy Francisco de Toledo. We examine the transformations in mine labour carried out by the Spanish colonial polity; these had a significant effect not only on mining, but also on all labour relations in the southern colonial Andes.Fil: Gil Montero, Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Instituto de Geografía, Historia y Ciencias Sociales. Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto de Geografía, Historia y Ciencias Sociales; ArgentinaFil: Zagalsky, Paula Cecilia. Universidad Nacional de Jujuy; Argentina. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Squalene stimulates a key innate immune cell to foster wound healing and tissue repair

Anti-inflammatory effects of virgin olive oil (VOO) have been described recently, along with its wound healing effect. One of the main minor compounds found in VOO is squalene (SQ), which also possesses preventive effects against skin damage and anti-inflammatory properties. The inflammatory response is involved in wound healing and manages the whole process by macrophages, among others, as the main innate cells with a critical role in the promotion and resolution of inflammation for tissue repair. Because of that, this work is claimed to describe the role that squalene exerts in the immunomodulation of M1 proinflammatory macrophages, which are the first cells implicate in recent injuries. Pro- and anti-inflammatory cytokines were analysed using TPH1 cell experimental model. SQ induced an increase in the synthesis of anti-inflammatory cytokines, such as IL-10, IL-13, and IL-4, and a decrease in proinflammatory signals, such as TNF-α and NF-κB in M1 proinflammatory macrophages. Furthermore, SQ enhanced remodelling and repairing signals (TIMP-2) and recruitment signals of eosinophils and neutrophils, responsible for phagocytosis processes. These results suggest that SQ is able to promote wound healing by driving macrophage response in inflammation. Therefore, squalene could be useful at the resolution stage of wound healing

Naturally lignan-rich foods: a dietary tool for health promotion?

Dietary guidelines universally advise adherence to plant-based diets. Plant-based foods confer considerable health benefits, partly attributable to their abundant micronutrient (e.g., polyphenol) content. Interest in polyphenols is largely focused on the contribution of their antioxidant activity to the prevention of various disorders, including cardiovascular disease and cancer. Polyphenols are classified into groups, such as stilbenes, flavonoids, phenolic acids, lignans and others. Lignans, which possess a steroid-like chemical structure and are defined as phytoestrogens, are of particular interest to researchers. Traditionally, health benefits attributed to lignans have included a lowered risk of heart disease, menopausal symptoms, osteoporosis and breast cancer. However, the intake of naturally lignan-rich foods varies with the type of diet. Consequently, based on the latest humans’ findings and gathered information on lignan-rich foods collected from Phenol Explorer database this review focuses on the potential health benefits attributable to the consumption of different diets containing naturally lignan-rich foods. Current evidence highlight the bioactive properties of lignans as human health-promoting molecules. Thus, dietary intake of lignan-rich foods could be a useful way to bolster the prevention of chronic illness, such as certain types of cancers and cardiovascular disease

Long-term results between interval surgery and follow-up after percutaneous cholecystostomy: a retrospective cohort study

Introduction: Although cholecystectomy is the treatment of choice for acute cholecystitis (AC), in patients with high surgical risk percutaneous cholecystostomy (PC) is chosen in some cases. The aim of this report is to follow up these patients and evaluate biliary recurrences after PC. Methods: A descriptive retrospective study was carried out in a third level hospital from August 2005 to December 2014. All patients diagnosed with acute lithiasis cholecystitis who were indicated as initial treatment with antibiotic therapy and PC echo-guided were included. Patients requiring emergent cholecystectomy during hospital and those who died during the AC episode were excluded. After hospital discharge, the patients were divided into two groups group 1 (interval cholecystectomy) and group 2 (no surgery). Results: From the 86 healed patients, there were 8 losses in the follow-up, so 78 patients were analyzed group 1 (n = 12) and group 2 (n = 66

Comorbidities in a sample of adults with HIV in Puerto Rico: an exploratory study.

Background: Puerto Rico is among the areas with the highest estimated rates of people living with HIV in the United States. Despite the epidemiologic data available, there is limited real-world information that can help understand the comorbidities of people with HIV. In this study, we describe common comorbidities among adults with HIV attending treatment clinics in Puerto Rico. Methods: An exploratory, retrospective, cross-sectional study was conducted at five HIV clinics in Puerto Rico. A random sample of medical records was reviewed. Descriptive statistics were used to summarize patient demographics, morbidity, and clinical characteristics. Multivariate analyses were conducted to explore comorbidities by age and sex. Results: A total of 250 (179 men; 71 women) medical records were reviewed. Participants\u27 mean age was 47.9 years and on average they had been living with HIV for 9 years. Most (97.6%) had at least one comorbidity. The most common comorbidities were dyslipidemia and hypertension. Men were more likely to have been diagnosed with alcohol misuse while women were more likely to have been diagnosed with obesity, human papillomavirus (HPV), hypothyroidism, and osteoporosis. Participants younger than 50 years of age were more likely to have history of alcohol misuse while older individuals (50 years and old) were more likely to have been diagnosed with dyslipidemia, hypertension, and diabetes. Adjusting by sex and age, women were more likely to have been diagnosed with obesity and depression and those older than 50 years were more likely to have had a diagnosis of dyslipidemia, hypertension, HPV, and diabetes. Conclusions: This is one of the few studies assessing comorbidities among adults with HIV in Puerto Rico, among Latino/Hispanics within the United States, and Latin America. Consistent with other studies, cardiovascular diseases are common among adults with HIV in Puerto Rico. Findings support the need for awareness and real-world evidence about comorbidities among people with HIV when implementing screenings and prescribing drugs