Superfluid to normal phase transition in strongly correlated bosons in two and three dimensions

Using quantum Monte Carlo simulations, we investigate the finite-temperature phase diagram of hard-core bosons (XY model) in two- and three-dimensional lattices. To determine the phase boundaries, we perform a finite-size-scaling analysis of the condensate fraction and/or the superfluid stiffness. We then discuss how these phase diagrams can be measured in experiments with trapped ultracold gases, where the systems are inhomogeneous. For that, we introduce a method based on the measurement of the zero-momentum occupation, which is adequate for experiments dealing with both homogeneous and trapped systems, and compare it with previously proposed approaches.Comment: 13 pages, 11 figures. http://link.aps.org/doi/10.1103/PhysRevA.86.04362

Fuga de cerebros en los Hospitales del Estado

En pleno siglo XXI, hay que adecuar la visión a los cambios tecnológicos y a las exigencias que la salud ocupacional pide, para tratar de darle al empleado no solo una buena cobertura en vacunas, sino también, satisfacción laboral. La satisfacción laboral es un tema que ha sido discutido por especialistas como Edwin Locke (psicólogo laboral). Para éste, cada individuo, según sus necesidades y expectativas, hace un juicio de valor en su entorno laboral, logrando satisfacción y/o insatisfacción. Es decir, que tal vez unas enfermeras se sientan satisfechas de trabajar en hospitales privados porque hay menos riesgo de contagio, hay más recursos y equipo, aunque su remuneración sea menor. En los hospitales del Estado, hay más trabajo y a la vez, menos recursos humanos y de materiales, en consecuencia mayor estrés laboral. Si bien es cierto que ahora se les da la oportunidad a muchos profesionales jóvenes encargarse de los servicios, hay todavía servicios, en áreas críticas, en donde no se realiza la rotación de puestos y tampoco se le da mucho apoyo al personal que estudia y trabaja, con la flexibilidad de los horarios. No podemos dejar de lado a las enfermeras que contraen enfermedades comunes crónicas, ocasionadas por el trabajo y/u ocupacionales que limitan su función. Hemos observado, no solo descontento y frustración en salas recargadas de trabajo, donde no baja el nivel de exigencias, saliendo las rotadoras y encargadas en turnos de 12 horas para poder dejar lo mejor posible el servicio. Con el agotamiento continuo, el desánimo y la falta de un sistema de incentivos, llegamos a la deserción de enfermeras que buscan estabilidad laboral y disminuir el riesgo del Síndrome de Burn-out. Muchos profesionales, ya con más años de servicio, demuestran síntomas de descontento por falta de reconocimiento, exceso de trabajo e incluso, apatía en su trato hacia los compañeros y pacientes. Lo anterior lleva al consiguiente aumento de las enfermedades comunes y al ausentismo laboral. La fuga de cerebros es uno de los más graves problemas que enfrenta la salud pública, ya que, al no realizar cambios significativos a nivel del Sistema, por más que se gradúen enfermeras en nuestras Universidades, no tendremos recursos humanos que trabajen con eficiencia, que sienta que este trabajo es una bendición y no un castigo. La fuga de cerebros de los hospitales debe hacer reflexionar a los administrativos de las instituciones de salud, quienes pueden realizar rondas durante los servicios, encuestas al personal y círculos de calidad con el fin de llegar a un consenso, mediante el cual se busquen los mecanismos que contribuyan a evitar la pérdida de profesionales valiosos. Entre las medidas, se sugiere una ordenada reingeniería del personal según preparación y desempeño por puestos. Establecer con apoyo privado, incentivos para enaltecer la autoestima del personal de todas las áreas. Pero, sobre todo, debemos tener presente que lo que mueve el 20 corazón de una institución, no es la tecnología, sino el carisma de la gente que trabaja en ella y, el amor que entregan a lo que hacen. Podríamos señalar que la burocratización de las instituciones de salud y la poca disposición de sus máximos líderes, para promover cambios que fortalezcan la satisfacción y buenas relaciones interpersonales, influye en la fuga de cerebros de las instituciones, ya que la producción y la sobrecarga de trabajo van de la mano, provocando al trabajador mayor agotamiento físico y mental. La sobrecarga de trabajo y la insatisfacción laboral, no solo aumenta el riesgo del síndrome del quemado, con todas sus consecuencias, que van desde irritabilidad, taquicardia, insomnio, entre otras, hasta llegar a la depresión, el aislamiento social y hasta el suicidio

The Rap Net: a geodetic positioning network for Andalusia (South Spain)

In this paper we present a description of the Andalusian Positioning Network, RAP: its objectives; design; development; its problems and its present status. This geodetic network consists of 22 permanent GPS stations whose surveying will provide the data required to obtain relative positions of any place in Andalusia after applying some post-processing techniques and real-time differential corrections. Thus, high-precision geodetic coordinates referred to the WGS-84 system will be provided for anywhere in Andalusia. The station in the network can broadcast a differential correction via internet. Nine stations can also broadcast the RTK corrections via radio. The network has been designed to cover Andalusia and to provide real-time differential corrections in the whole area. The RAP network is referred to the EUREF system and is the new reference frame in Andalusia for the Institute of Cartography of Andalusia’s new cartography. It will also be used to settle photogrametric points or marks for the georeferencing of satellite images; to establish control points for reference networks in civil engineering or GIS applications; for numerous scientific and technological applications, such as precise geoid determination and tropospheric, ionospheric, and climatological studies, among others. Its millimetric precision will ensure success when integrating new projects with other cartographies

Mecanical properties dependency on chemical composition of spheroidal graphite cast iron

Con este trabajo se pretende estudiar la composición química de cuatro escaleras de fundición dúctil para determinar la influencia de los diferentes elementos de aleación sobre la microestructura y las propiedades mecánicas. Las cuatro escaleras tienen las mismas dimensiones de 200 x 100 x 50 (mm). Para determinar cada una de las propiedades de las cuatro fundiciones, hemos considerado que las mismas han tenido diferente velocidad de enfriamiento, de lo que se deriva, que el tamaño de grano varía para cada uno de los casos. En este trabajo, se ha realizado un estudio de las diferentes microestructuras de las escaleras. Se ha considerado el análisis de la influencia del grosor sobre la dureza de cada probeta. No se ha empleado ningún tratamiento térmico. Se ha determinado la resistencia a la tracción y límite elástico. Se han realizado ensayos de Charpy y de mecánica de la fractura.With this work, we try to study the chemical composition of four specimens in form of stair of ductile cast iron to determine the influence of the chemical composition of different alloying elements on microstructure and on mechanical properties. The dimensions of each specimens are 200 x 100 x 50 mm. Cooling rate has been considered to be different for each one of the four stairs when determining the mechanical properties, therefore, grain size varies in each case. In this analysis, the different microstructures of the stairs have been considered. influence of the thickness on hardness of each specimen has been taken into account. Heat treatments are not used. Yield and tensile strength are determined. Charpy tests have been done. Rockwell and Brinell hardness are determined

Genomic and phenotypic analysis of Vavilov's historic landraces reveals the impact of environment and genomic islands of agronomic traits.

The Vavilov Institute of Plant Genetic Resources (VIR), in St. Petersburg, Russia, houses a unique genebank, with historical collections of landraces. When they were collected, the geographical distribution and genetic diversity of most crops closely reflected their historical patterns of cultivation established over the preceding millennia. We employed a combination of genomics, computational biology and phenotyping to characterize VIR's 147 chickpea accessions from Turkey and Ethiopia, representing chickpea's center of origin and a major location of secondary diversity. Genotyping by sequencing identified 14,059 segregating polymorphisms and genome-wide association studies revealed 28 GWAS hits in potential candidate genes likely to affect traits of agricultural importance. The proportion of polymorphisms shared among accessions is a strong predictor of phenotypic resemblance, and of environmental similarity between historical sampling sites. We found that 20 out of 28 polymorphisms, associated with multiple traits, including days to maturity, plant phenology, and yield-related traits such as pod number, localized to chromosome 4. We hypothesize that selection and introgression via inadvertent hybridization between more and less advanced morphotypes might have resulted in agricultural improvement genes being aggregated to genomic 'agro islands', and in genotype-to-phenotype relationships resembling widespread pleiotropy

Medical resource use in patients with psoriatic arthritis in a comprehensive rheumatological center in Colombia

Psoriatic arthritis (PsA), a chronic systemic inflammatory disorder, impairs the quality of life of patients. The aim of this study was to describe the medical resource use in patients with PsA in a comprehensive rheumatological center in Colombia. We retrospectively analyzed patients diagnosed with PsA who were attended in a center of excellence for rheumatic diseases located in Bogotá, D.C. Colombia, from January to December 2019. A database of medical records was analyzed to identify the use of medical resources classified by specialized physician visits, medications and ambulatory services (e.g., diagnostic, laboratory or image procedures, physical therapy). We reported absolute and relative frequencies among diagnostic groups. This study had no risk for patients. Ninety-six patients with PsA were studied, 57% were women. The mean age was 58.08 (±12.3 years), 90.63% of diagnostic was arthropathic psoriasis, other diagnostics were rheumatoid arthritis without rheumatoid factor, unspecified site (2.08%) and psoriasis, unspecified (2.08%) (ICD-10 code L405, M060, L409, respectively). In terms of treatments, most of the patients used a conventional disease-modifying antirheumatic drugs (DMARDs), methotrexate was the most frequent (represented the 14% of prescription and 78% of patients). On the other hand, 56.25% of patients receive treatment with biological DMARDs (10% of prescription). Among these biologicals, adalimumab (17.71%) and secukinumab (16.67%) were the most used. Regarding other health services, the visit to the specialist and the RX were the most common (83.33% of patients). Chest RX and column RX (17.71% each) had the highest frequency. This is one of the first approaches to the estimation of use of medical resources of PsA in Colombia. Frequency of DMARS use was associated to the severity and medical control of patients

Predicting Many Properties of a Quantum System from Very Few Measurements

Predicting the properties of complex, large-scale quantum systems is essential for developing quantum technologies. We present an efficient method for constructing an approximate classical description of a quantum state using very few measurements of the state. This description, called a ‘classical shadow’, can be used to predict many different properties; order log(M) measurements suffice to accurately predict M different functions of the state with high success probability. The number of measurements is independent of the system size and saturates information-theoretic lower bounds. Moreover, target properties to predict can be selected after the measurements are completed. We support our theoretical findings with extensive numerical experiments. We apply classical shadows to predict quantum fidelities, entanglement entropies, two-point correlation functions, expectation values of local observables and the energy variance of many-body local Hamiltonians. The numerical results highlight the advantages of classical shadows relative to previously known methods

Genetic Patterns of Domestication in Pigeonpea (Cajanus cajan (L.) Millsp.) and Wild Cajanus Relatives

Pigeonpea (Cajanus cajan) is an annual or short-lived perennial food legume of acute regional importance, providing significant protein to the human diet in less developed regions of Asia and Africa. Due to its narrow genetic base, pigeonpea improvement is increasingly reliant on introgression of valuable traits from wild forms, a practice that would benefit from knowledge of its domestication history and relationships to wild species. Here we use 752 single nucleotide polymorphisms (SNPs) derived from 670 low copy orthologous genes to clarify the evolutionary history of pigeonpea (79 accessions) and its wild relatives (31 accessions). We identified three well-supported lineages that are geographically clustered and congruent with previous nuclear and plastid sequence-based phylogenies. Among all species analyzed Cajanus cajanifolius is the most probable progenitor of cultivated pigeonpea. Multiple lines of evidence suggest recent gene flow between cultivated and non-cultivated forms, as well as historical gene flow between diverged but sympatric species. Evidence supports that primary domestication occurred in India, with a second and more recent nested population bottleneck focused in tropical regions that is the likely consequence of pigeonpea breeding. We find abundant allelic variation and genetic diversity among the wild relatives, with the exception of wild species from Australia for which we report a third bottleneck unrelated to domestication within India. Domesticated C. cajan possess 75% less allelic diversity than the progenitor clade of wild Indian species, indicating a severe ‘‘domestication bottleneck’’ during pigeonpea domestication