Free fermionic propagators on a lattice

A method used recently to obtain a formalism for classical fields with non-local actions preserving chiral symmetry and uniqueness of fermion fields yields a discrete version of Huygens' principle with free discrete propagators that recover their continuum forms in certain limit.Comment: LaTex document, 13 pages, 1 figure. Minor changes, two references adde

Estrategias en el coste de producción para Incrementar la rentabilidad de la empresa incofer contratistas generales E.I.R.L. Bagua – Amazonas

La presente investigación: Estrategias en el Coste de Producción para Incrementar la Rentabilidad de la Empresa Incofer Contratistas Generales E.I.R.L. Bagua – Amazonas, consideró como objetivo general Elaborar Estrategias en el coste de Producción para incrementar la rentabilidad de la empresa Incofer Contratista Generales E.I.R.L. Bagua-Amazonas. La investigación tuvo un enfoque mixto, alcance descriptivo y propositiva; la población y muestra fue representada por 18 trabajadores y por los estados financieros; se empleó las técnicas de encuesta, entrevista y análisis documental. Se obtuvo como resultados que la empresa Incofer Contratista Generales E.I.R.L. Bagua-Amazonas, cuenta con estrategias para el control de sus costos sin embargo, no son eficientes ya que no son puestas en práctica, así como no cuenta con políticas bien definas ni determinadas, lo que generó que los costos se incrementen en los últimos periodos; además se evidenció que la rentabilidad ha disminuido para el año 2020, porque sus costos se han incrementado, a pesar que sus activos han sido rentables, además se evidenció que el presupuesto analizado tuvo un incremento del 63% del presupuesto inicial al presupuesto final; dado al inadecuado control de los costos. Es por ello que se han elaborado estrategias para tener mayor control sobre el coste de producción, con la finalidad de incrementar la rentabilidad de la empresaThe present investigation: Strategies in the Cost of Production to Increase the Profitability of the Company Incofer General Contractors E.I.R.L. Bagua - Amazonas, considered as a general objective Develop strategies in the cost of production to increase the profitability of the company Incofer Contratista Generales E.I.R.L. Bagua-Amazonas. The research had a mixed approach, descriptive and purposeful scope; 18 workers represented the population and sample and the financial statements used the techniques of survey, interview and documentary analysis. The results were that the company Incofer Contratista Generales E.I.R.L. Bagua Amazonas, has strategies for controlling its costs, however, they are not efficient since they are not implemented, as well as it does not have well-defined policies or policies, which causes the costs to increase in recent periods ; It is also evident that profitability has decreased for the year 2020, because its costs have increased, although its assets have been profitable. In addition, it was evidenced that the analyzed budget had an increase of 63% from the initial budget to the final budget; due to inadequate cost control. That is why strategies have been developed to have greater control over the cost of production, with the strategy of increasing the profitability of the companyTesi

On the Gas Surrounding High Redshift Galaxy Clusters

Francis & Hewett (1993) identified two 10-Mpc scale regions of the high redshift universe that were seemingly very overdense in neutral hydrogen. Subsequent observations showed that at least one of these gas-rich regions enveloped a cluster of galaxies at redshift 2.38. We present improved observations of the three background QSOs with sightlines passing within a few Mpc of this cluster of galaxies. All three QSOs show strong neutral hydrogen absorption at the cluster redshift, suggesting that this cluster (and perhaps all high redshift clusters) may be surrounded by a ~5 Mpc scale region containing ~ 10^12 solar masses of neutral gas. If most high redshift clusters are surrounded by such regions, we show that the gas must be in the form of many small ( 0.03 cm^-3) clouds, each of mass < 10^6 solar masses. These clouds are themselves probably gathered into > 20 kpc sized clumps, which may be galaxy halos or protogalaxies. If this gas exists, it will be partially photoionised by the UV background. We predict the diffuse Ly-alpha flux from this photoionisation, and place observational limits on its intensity.Comment: 19 pages, 5 figures. Accepted for publication in PAS

Migração em cidades médias do interior nordestino: a atração migratória como elemento distintivo

In Brazil, the debate on intermediary cities gained prominence when the urban population supplanted the rural during the 1970s, and when, in the metropolises, there began a deconcentration of the population which, as from the 1980s, was redistributed across the metropolitan surroundings and the interior of the states. Thus, the aim of the present study is to discover how many intermediary cities there are, where they are located in the interior of the Northeastern region and their relevance in attracting migrants. Microdata was used from the 2010 demographic census, specifically the fixed data topic that questions migrants on their place of residence five years before the reference date of the survey. The results have demonstrated that, although most cities presented a population decline, with a move towards very distant locations (interregional), a large number play a relevant role in intraregional attraction (medium distance) and, notably, intrastate (short distance), which exercise the role of deconcentrating the population of the metropolises. The main immigrant destinations were Caruaru (PE), Petrolina (PE) and Mossoró (RN). On the other hand, the cities presenting the highest negative migration balance were Imperatriz (MA), Itabuna (BA) and Ilhéus (BA). Furthermore, through a literature review and data collected by the study, it was discovered that the definition of an intermediary city based on the criterion of population size is no longer recommended for a country of continental dimensions and distinct stages of development such as Brazil.En Brasil, el debate sobre las ciudades medianas se destaca cuando la población urbana suplanta a la población rural en la década de 1970 y las metrópolis comienzan a desconcentrar a la población y redistribuirla a los estados metropolitanos e interiores a partir de la década de 1980. Por lo tanto, este trabajo apunta a saber cuántos hay, dónde están ubicados en el interior del noreste y la relevancia de las ciudades medianas para atraer migrantes. Se utilizaron microdatos del censo demográfico de 2010, precisamente la fecha fija del elemento que pregunta a los migrantes sobre su lugar de residencia cinco años antes de la fecha de referencia de la encuesta. Los resultados muestran que, aunque la mayoría de las ciudades muestran pérdida de población en direcciones distantes (interregional), una gran parte es relevante en la atracción intrarregional (media distancia) y, especialmente, en la atracción intraestatal (corta distancia), que juegan el papel de desconcentrar a la población de las metrópolis. Las principales rutas de los inmigrantes fueron Caruaru (PE), Petrolina (PE) y Mossoró (RN). Por otro lado, las ciudades con los saldos migratorios negativos más altos fueron Imperatriz (MA), Itabuna (BA) e Ilhéus (BA). Además, a través de una revisión de la literatura y los datos recopilados por el estudio, parece que la definición de una ciudad promedio basada en el criterio del tamaño de la población no es la más adecuada para un país con dimensiones continentales y en diferentes etapas de desarrollo como Brasil.No Brasil, o debate sobre cidades médias ganha destaque quando a população urbana suplanta a rural nos anos 1970 e as metrópoles começam a desconcentrar a população e redistribuí-la pelo entorno metropolitano e interior dos estados a partir da década de 1980. Assim, este trabalho objetiva saber quantas são as cidades médias, onde estão localizadas no interior do Nordeste e qual sua relevância na atração de migrantes. Foram utilizados os microdados do Censo Demográfico 2010, precisamente o quesito data fixa, que pergunta ao migrante sobre o lugar de residência cinco anos antes da data de referência da pesquisa. Os resultados mostram que, apesar de a maioria das cidades apresentarem perda populacional para destinos de mais longas distâncias (inter-regional), grande parte é relevante na atração intrarregional (média distância) e, notadamente, intraestadual (curta distância), que exercem o papel de desconcentrar a população das metrópoles. Os principais rumos dos imigrantes foram Caruaru (PE), Petrolina (PE) e Mossoró (RN). Por outro lado, as cidades com maiores saldos migratórios negativos foram Imperatriz (MA), Itabuna (BA) e Ilhéus (BA). Ademais, por meio da revisão da literatura e dos dados levantados pelo estudo, constata-se que a definição de cidade média baseada no critério de tamanho populacional não é o mais indicado para um país com dimensões continentais e em distintos estágios de desenvolvimento como o Brasil

Competencias directivas y compromiso de gestión escolar percibidos por los docentes de instituciones educativas públicas. Ancash, 2022

En el presente estudio se tuvo como objetivo general determinar la relación existente entre las competencias directivas y compromisos de gestión escolar percibidos por los docentes de instituciones educativas públicas, Ancash, 2022. Para ello el enfoque empleado fue cuantitativo, de un diseño no experimental, descriptivo – correlacional, además, la investigación tuvo la participación de 150 profesores del nivel primaria y secundaria, quiénes respondieron a una serie de interrogantes de dos cuestionarios. Finalmente, los resultados demostraron que las competencias directivas presentan un nivel regular, establecido por el 76% de los docentes, mientras que los compromisos de la gestión escolar, se encuentran en un nivel alto, manifestado por el 58.7%. En conclusión, existe un nivel de correlación positiva, alta y directa entre las competencias directivas y el compromiso de gestión escolar, dado que se obtuvo un valor Rho igual a 0,740** y un p – valor de 0.000, que siendo este último menor a 0.05, lo que quiere decir que la relación es significativa y por tanto se acepta la hipótesis alterna

Asociación entre depresión y control glicémico en pacientes con diabetes mellitus tipo 2 de los consultorios del servicio de Endocrinología del Hospital Nacional Daniel Alcides Carrión, en el periodo octubre-diciembre del 2019

Objetivo: Determinar la asociación existente entre depresión y el pobre control glicémico en pacientes con diabetes mellitus tipo 2. Material y métodos: Estudio tipo observacional, analítico y transversal, realizado en los consultorios externos de la unidad de Endocrinología del Hospital Nacional Daniel Alcides Carrión del Callao – Perú, durante el periodo octubre-diciembre del 2019. Las variables independientes fueron el sexo, la edad (<60 vs. 60 a más), el tipo de tratamiento (vía oral vs. insulina) y el control glicémico, determinado a través de la hemoglobina glicosilada (<7% vs 7% a más). La variable dependiente fue depresión, definido como un puntaje de 15 o más obtenido a través de la prueba PHQ-9. Resultados: En la muestra obtenida de 125 pacientes diabéticos, se encontró una edad promedio de 60 años, 77 (61.6%) pacientes fueron mujeres y 45 (36%) pacientes recibía insulina. Se encontró presencia de depresión en 37 (29.6%) pacientes y de mal control glicémico en 62 (49.6%) pacientes. Se hallaron como factores independientes asociados a la presencia de depresión en pacientes con diabetes mellitus tipo 2 el sexo femenino, con RP=9.737 (IC 95%: 3.014-31.455, p=0.000) y el mal control glicémico, con RP=3.793 (IC 95%: 1.32-10.898, p=0.013) Conclusiones: Se determinó que existe asociación significativa entre el pobre control glicémico y la presencia de depresión en la población estudiada de pacientes diabéticos. También se encontró asociación entre el sexo femenino y depresión en la misma población.Tesi

Engineering design : eicosane microcapsules synthesis and application in polyurethane foams aiming to diminish wheelchair cushion effect on skin temperature

Thermal comfort of wheelchairs still requires improvements, since users remain on the chair for as long as 12 h a day. Increased sweating makes the skin more susceptible to colonization by fungi and bacteria, and may cause pressure ulcers. In this sense, the microencapsulation of Phase-Change Materials (PCMs) may help to enhance wheelchair cushion comfort by regulating heat exchange. This study describes the production of PCM microcapsules and their application in flexible polyurethane foams after expansion, and assesses improvements in heat exchange. Microcapsules with eicosane core coated with melamine-formaldehyde were produced. Eicosane is a thermoregulation agent whose phase-change temperature is near that of the human body’s. Microcapsules were characterized by thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy, and Fourier transform infrared spectroscopy. Then, microcapsules were applied on polyurethane foams by vacuum filtration and high-pressure air gun. Samples were exposed to a heat source and analysed by infrared thermography. The results indicate that thermal load increased in samples treated with microcapsules, especially by pressure air gun, and show that it is possible to enhance thermal comfort in wheelchair seats. Thereby, this study contributes to enhance quality of life for wheelchair users, focusing on thermal comfort provided by cushion seats made from PU foam

The use of different stingless bee species to pollinate cherry tomatoes under protected cultivation

Under standard greenhouse conditions, the tomato fruits of spontaneous self-pollination are expected to be of lower quality than those of bee pollination, as well as that simultaneously use different bee species which can complement pollination services. To test these hypotheses, we evaluated the complementarity of pollination services from the use of three native stingless bee species that have distinct foraging behaviors, Melipona bicolor Lepeletier 1836, Nannotrigona testaceicornis (Lepeletier 1836) and Partamona helleri (Friese 1900) during flowering of cherry tomatoes in greenhouses. Fruit quality parameters resulted from pollination experiments were measured and the acclimatization of the analyzed bee species was evaluated. Visits of M. bicolor and N. testaceicornis to the tomato flowers contributed significantly to the increase in the average weight, seed number, and thickness of the pericarp (only for N. testaceicornis) of the fruits, compared to the spontaneous self-pollination treatment. Partamona helleri, however, did not show any pollen collection behavior in the experimental conditions. Although N. testaceicornis do not perform the buzzing behavior, fruits from its pollination were equivalent to those fruits from pollination by M. bicolor. The simultaneous use of bee species with different flower-visiting behaviors can optimize tomato pollination in greenhouses, contributing significantly to the quality of the fruits and the increase of productivity and consequently the commercial value

Association between adiposity and systemic atherosclerosis: a protocol of a cross-sectional autopsy study.

IntroductionAdiposity has been associated with atherosclerosis in clinical studies. However, few autopsy studies have investigated this association, and they had only examined the coronary artery disease. Moreover, most studies had small sample sizes and were limited to middle-aged or young adults. Our aim is to investigate the association between adiposity and systemic atherosclerosis in an autopsy study.Methods and analysisA sample of 240 deceased with 30 years or more will be evaluated. The sample size was calculated using the lowest correlation coefficient found in previous studies (r=0.109), assuming a power of 90% and α=0.05. We will collect information about sociodemographics, frequency of previous contact of the deceased's next of kin and cardiovascular risk factors. We will measure neck, waist and hip circumferences, weight, height and abdominal subcutaneous tissue thickness, and then we will calculate the body mass index, waist-to-hip ratio, waist-to-height ratio and body shape index. We will also weigh the pericardial and abdominal visceral fat, the heart, and we will measure the left ventricular wall thickness. We will evaluate the presence of myocardial infarction, the degree of atherosclerosis in the aorta, carotid, coronary and cerebral arteries and plaque composition in carotid, coronary and cerebral arteries. For each individual, we will fix arterial and adipose tissue samples in 10% formalin and freeze another adipose tissue sample at -80°C for future studies.Ethics and disseminationEthical approval was granted by the Ethics Committee of University of Sao Paulo Medical School, Brazil. Results will be submitted for publication in a peer-reviewed journal