The time traveler's guide to the quantization of zero modes

We study the relationship between the quantization of a massless scalar field on the two-dimensional Einstein cylinder and in a spacetime with a time machine. We find that the latter picks out a unique prescription for the state of the zero mode in the Einstein cylinder. We show how this choice arises from the computation of the vacuum Wightman function and the vacuum renormalized stress-energy tensor in the time-machine geometry. Finally, we relate the previously proposed regularization of the zero mode state as a squeezed state with the time-machine warp parameter, thus demonstrating that the quantization in the latter regularizes the quantization in an Einstein cylinder

Dynamical mechanism for generation of arrhythmogenic early afterdepolarizations in cardiac myocytes: insights from in silico electrophysiological models

We analyze the dynamical mechanisms underlying the formation of arrhythmogenic early afterdepolarizations (EADs) in two mathematical models of cardiac cellular electrophysiology: the Sato et al. biophysically detailed model of a rabbit ventricular myocyte of dimension 27 and a reduced version of the Luo-Rudy mammalian myocyte model of dimension 3. Based on a comparison of the two models, with detailed bifurcation analysis using spike-counting techniques and continuation methods in the simple model and numerical explorations in the complex model, we locate the point where the first EAD originates in an unstable branch of periodic orbits. These results serve as a basis to propose a conjectured scheme involving a hysteresis mechanism with the creation of alternans and EADs in the unstable branch. This theoretical scheme fits well with electrophysiological experimental data on EAD generation and hysteresis phenomena. Our findings open the door to the development of novel methods for pro-arrhythmia risk prediction related to EAD generation without actual induction of EADs

Utilization of Cooked Cassava and Taro as Alternative Feed in Enhancing Pig Production in Ecuadorian Backyard System

Pork production in Ecuador is of significant economic and nutritional importance. Many of these operations are family- or backyard-based and utilize alternative feed ingredients to reduce production costs. The current study aimed to determine the chemical composition of cooked cassava and taro, and to evaluate their inclusion in the feed of backyard pigs during the growth and fattening phases. A total of 42 castrated pigs from two geographic locations in Ecuador were studied over a period of 100 days, during which their weight and measurements were recorded at three-week intervals. At the end of the experiment, ileum samples were collected from the slaughtered pigs in order to calculate the apparent digestibility of the feed. The crude protein levels of cassava and taro were found to be 3.2% and 2.1%, respectively. The combination of cooked cassava and taro was found to be a suitable replacement for corn, with the best results observed in the group receiving a diet incorporating 21% each of cassava and taro. Analysis of the ileal content also revealed that this group exhibited the highest nitrogen assimilation from the diet

Modeling tree-growth: Assessing climate suitability of temperate forests growing in Moncayo Natural Park (Spain)

In the past few decades, temperate forests have been negatively altered by numerous anthropogenic activities and by the impact of ongoing climate change. These changes may require management actions to help preserve some forest tree species. In this sense, highly-detailed knowledge of tree growth and survival across territorial and climatic gradients will be important for forest conservation. We developed a novel approach to determine the optimal zones of forest growth and expansion through climate suitability maps, using a dense tree-ring network of four forest species in Moncayo Natural Park and high-resolution climate data. Our results showed that the mixed-effects models developed using climate data and tree size were able to predict between 65 and 80% of growth variability along the climatic gradient. All studied species were influenced by climate, and the relationship between growth and climate significantly differed along the prevailing climate gradient. Moreover, the suitability maps showed that the current species distribution is limited, and their application may serve as a tool for adaptive management in forests subjected to climate change

Formación continuada en un equipo de atención primaria: análisis de las sesiones docentes 1996-1998

ObjetivoDescribir las sesiones docentes de un equipo de atención primaria en el trienio 1996-1998. Identificar los profesionales que las realizaron, así como estudiar las áreas del conocimiento abordadas.DiseñoEstudio descriptivo transversal, retrospectivo.EmplazamientoCentro de salud docente perteneciente a una zona de salud rural.ParticipantesTotal de sesiones docentes realizadas durante el trienio estudiado (n = 249).IntervencionesDe la hoja de registro mensual del programa de formación continuada de nuestra gerencia, se extrajeron las siguientes variables: fecha actividad, duración, número de asistentes, tipo de sesión, profesional docente y contenido de actividad (clasificada por patología según órganos y sistemas para sesión bibliográfica, clínica y con experto; cartera servicios de atención primaria-INSALUD 1996 para sesión sobre programa; informática).Mediciones y resultados principalesSesiones por mes: media 6,9 (DE, 4,8). Media asistentes: 9,3 (DE, 3,01). Duración media: 36,5 minutos (DE, 11,0). Tipo de sesión: bibliográfica, 65,2%; sobre programa, 18; sesión con experto, 7,2; informática, 5,6; clínica, 4. Responsables docentes: médico residente, 39,4%; médico de familia tutor, 34,9; médico de familia no tutor, 7,2; ATS, 6,4; médico hospitalario, 4; médico de familia sustituto, 3,6; farmacéutico, 2,8; pediatra, 1,2; fisioterapeuta, 0,4. Contenido actividades más frecuentes: patología general inespecífica, 16,1%; enfermedades de la piel, 8,8, y enfermedades del sistema endocrino, 7,6%.ConclusionesBaja frecuencia de sesiones clínicas. Los responsables docentes fueron mayoritariamente médicos de familia tutores y médicos residentes, siendo escasa la participación del resto de personal.ObjectivesTo describe the teaching sessions of a primary care team in the three-year period 1996-1998. To identify the professionals who ran them and study the areas of knowledge tackled. Design. A retrospective, cross-over, descriptive study.SettingTeaching health centre belonging to a rural health district.ParticipantsAll the teaching sessions that took place during the three-year period (n = 249). Interventions. The following variables were extracted from the monthly register sheet of the ongoing training programme of our management: date of activity, duration, number attending, type of session, teaching professional and contents of activity (classified by pathology according to organs and systems for bibliographic, clinical and expert sessions; portfolio of 1996 Primary Care- INSALUD services for session on programme; computer studies).Measurements and main resultsMean sessions per month: 6.9 (SD: 4.8). Mean attendance: 9.3 persons (SD: 3.01). Mean length: 36.5 minutes (SD: 11.0). Type of session: bibliographic 65.2%, on programme 18%, session with expert 7.2%, computer studies 5.6%, clinical 4%. Responsible for teaching: intern 39.4%; family doctor tutor 34.9%; family doctor not a tutor 7.2%; nurse 6.4%; hospital doctor 4%; locum family doctor 3.6%; pharmacist 2.8%; paediatrician 1.2%; physiotherapist 0.4%. Most common contents: non-specific general pathology (16.1%), skin diseases (8.8%), diseases of the endocrine system (7.6%).ConclusionsLow frequency of clinical sessions. The teachers in charge were mainly family doctor tutors and interns, with the rest of the staff participating little

Influencia de la expropiación forzosa en la disponibilidad de terrenos para la ejecución de obras de modernización de regadíos

La evolución de la economía del país, ha hecho que los tipos de interés hayan disminuido de manera continuada en los últimos años. El hecho de que la determinación del valor de expropiación desde el año 2.007 se lleve a cabo mediante capitalización de rentas y que, por lo tanto, el valor de indemnización dependa del tipo de interés, ha ocasionado un efecto económico difícil para las partes beneficiarias en una expropiación. En este trabajo se estudia la evolución de la normativa, se cuantifican los resultados para el caso de una finca concreta de una explotación de algodón de regadío en el valle del Guadalquivir y se analizan los resultados. En el estudio puede observarse que en los últimos ocho años, el valor de mercado de la tierra ha seguido una tendencia a la baja. Por el contrario, el valor de indemnización por expropiación de la misma se ha disparado, lo que hace inviable a las comunidades de regantes la participación en la modernización de regadíos, así como a la Administración la aplicación del Plan Hidrológico Nacional o Plan Nacional de Regadíos. Estas circunstancias han hecho que, en octubre de 2.015 (Ley de carreteras) y noviembre de 2.015 (Texto refundido de Ley de Suelo), la legislación haya intentado paliar la situación, aunque sigue siendo insuficiente. Por ello se proponen algunas medidas a modo de conclusión al final del trabajo.The evolution of the country's economy has made that interest rates have decreased continuously in recent years. The fact that since the year 2007 the determination of the value of expropriation is being carried out through revenue capitalization, in which the indemnification value depends on the interest rate, has caused a difficult economic impact in the recipient parties of an expropriation. In this paper we study the evolution of the expropriation regulations as well as the assessment of the amount of money corresponding to the expropriation of a farm dedicated the production of cotton in the Guadalquivir valley. In the study it can be seen that over the last eight years the market value of the land has followed a downward trend. On the other hand, the value of compensation for land expropriation has been triggered, making infeasible to the irrigation communities their participation in the modernization of the irrigation systems and hinders the Administration the implementation of the National Hydrological Plan or the National Irrigation Plan. These circumstances have led the Government to try to alleviate the situation with new regulations (road act of October 2015 and revised text of law of soil of November 2015) which remain insufficient. Therefore some legislative proposals are given as conclusions at the end of this work

Characterization and Typology of Backyard Small Pig Farms in Jipijapa, Ecuador

To characterize the traditional systems of small pig producers in Jipijapa (Manabí, Ecuador) and to classify farms into representative categories, we interviewed fifty-five farmers from seven communities considering four dimensions: social, organizational, production methods, and local food resources. Multiple correspondence analyses and hierarchical clusters were carried out using the Ward method. The analysis differentiated communities based on social, productive, and local resource variables, showing three factors that accounted for 85.3% of the total variance: the socioeconomic dimension, related to the welfare of families, explained 34.4% of the variation, the care provided to animals explained 30.9%, and the management practices for the supply of food explained 20%. We identified five clusters that shared common characteristics: Group 1 included farmers from Albajacal, wage workers, and Creole pig breeders, Group 2 included farmers raising pigs under lockdown conditions, Group 3 typified traditional farms from the La Cuesta community, Group 4 included landowners, and Group 5 included professionalized farmers in Colón Alfaro. We also studied the supplied alternative food formulations made up of crop surpluses. The role of small pig farmers is a social activity linked to the location, the crops of each area, and the specific practices for the care of animals

Analyses of Genetic Diversity in the Endangered “Berrenda” Spanish Cattle Breeds Using Pedigree Data

Pedigree analyses of two endangered cattle breeds were performed in order to study the structure and the genetic variability in their populations. Pedigree data were analyzed from 12,057 individuals belonging to the “Berrenda en Negro” cattle breed (BN) and 20,389 individuals belonging to the “Berrenda en Colorado” cattle breed (BC) that were born between 1983 and 2020. BN and BC reference populations (RP) were set up by 2300 and 3988 animals, respectively. The generation interval in BN and BC reference populations was equal to 6.50 and 6.92 years, respectively. The pedigree completeness level was 82.76% in BN and 79.57% in BC. The inbreeding rates were 4.5% in BN and 3.4% in BC, respectively. The relationship among animals when they were born in different herds was 1.8% in BN and 5% in BC; these values increased to 8.5% and 7.7%, respectively when comparing animals that were born in the same herd. The effective number of founding herds was 23.9 in BN and 60.9 in BC. Number of ancestors needed to explain 50% of genes pool in the whole population was 50 and 101, in BN and in BC, respectively. The effective population size based on co-ancestries was 92.28 in BN and 169.92 in BC. The genetic variability has been maintained in both populations over time and the results of this study suggest that measures to promote the conservation of the genetic variability in these two breeds would go through for the exchange of breeding animals among farms and for monitoring the genetic contributions before implementing any selective action

Prevalence and factors associated with problematic internet use in a population of spanish university students

(1) Background: To examine the prevalence, and associated factors of, problematic Internet use in a sample of Spanish university students. (2) Methods: Cross-sectional descriptive study of a convenience sample of 698 university students. Self-esteem, alcohol consumption, perceived social support, depression, anxiety, stress and problematic Internet use were evaluated using the Rosenberg, CAGE, DUKE-UNC-11, DASS-21 and Young’s Internet Addiction Test, respectively. (3) Results: Problematic internet use was reported by 21% of respondents. Risk of problematic Internet use was independently associated with the preferred use of the smartphone, time of exposure to the Internet, less perceived social support, problematic alcohol consumption and symptoms of stress and anxiety. We found significant association between problematic internet use and time of exposure to the Internet, residential status, alcohol consumption, self-esteem, perceived social support and psychological distress, after bivariate analysis. (4) Conclusions: A considerable prevalence of problematic Internet use was found; in our sample problematic Internet use was associated with stress, alcohol consumption, anxiety and perceived social support. Strategies aimed at the early identification of problematic Internet use may lead to an improvement in the psychosocial health of the university student population. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Impacto de la pandemia de COVID-19 en la salud mental

The purpose of the present monograph is to provide a compilation of studies that demonstrate how the COVID-19 pandemic has affected the mental health of various groups of the population in Iberoamerican countries. The nine articles of this special issue analyse subjects such as isolation due to confinement, post-traumatic stress derived from exposure to the coronavirus, the differences in the level of well-being according to social class, the increase of depressive symptoms and suicidal ideation, the effect of the infection on psychological disorders, such as obsessive-compulsive disorder, the increase of anxiety symptoms and the resulting greater demand for psychological care, the effects of healthcare pressure on burnout experienced by healthcare workers, and the role of self-forgiveness and compassion in relation to personal growth and life satisfaction during the pandemic. In sum, this special issue is a sample of the scientific evidence on how this unusual crisis is affecting citizens' psychological health.El propósito del monográfico es presentar un compendio de estudios que muestran cómo la pandemia por la COVID-19 ha impactado la salud mental de diversos sectores de la población de países iberoamericanos. Nueve artículos analizan la soledad a causa del confinamiento, el estrés postraumático derivado de la exposición al coronavirus y sus consecuencias, las diferencias en el nivel de bienestar en función de la clase social, el incremento de la sintomatología depresiva y la ideación suicida, el impacto de la infección en trastornos psicológicos como el obsesivo compulsivo, el incremento de los síntomas de ansiedad y el aumento consecuente de la demanda de atención psicológica, la relación entre el ejercicio físico, pasear al perro y el estado afectivo durante el confinamiento, los efectos de la presión asistencial sobre el desgaste profesional de los trabajadores sanitarios y, finalmente, el papel del perdón a uno mismo y la compasión en relación al crecimiento personal y la satisfacción con la vida durante la pandemia. En suma, este número especial constituye una muestra de la evidencia científica acerca de cómo está afectando a la salud psicológica de la ciudadanía esta inusitada crisis