Magnetism and Quantum Melting in Moir\'e-Material Wigner Crystals

Recent experiments have established that semiconductor-based moir\'e materials can host incompressible states at a series of fractional moir\'e-miniband fillings. These states have been identified as generalized Wigner crystals in which electrons localize on a subset of the available triangular-lattice moir\'e superlattice sites. In this article, we use momentum-space exact diagonalization to investigate the many-body ground state evolution at rational fillings from the weak-hopping classical lattice gas limit, in which only spin degrees-of-freedom are active at low energies, to the strong-hopping metallic regime where the Wigner crystals melt. We specifically address the nature of the magnetic ground states of the generalized Wigner crystals at fillings $\nu$ = 1/3 and $\nu$ = 2/3.Comment: 12 pages, 8 figure

Correlación entre gérmenes aislados en cultivo de secreciones y riesgo de amputación en pie diabéticos ingresados en Hospital Bautista, Managua-Nicaragua, enero 2019- diciembre 2021

Analizar la correlación entre gérmenes aislados en cultivo de secreciones de pie diabético y el riesgo de amputación en pacientes ingresados en Hospital Bautista de Nicaragua, periodo enero 2019 a diciembre 2021. Diseño metodológico: Estudio observacional, descriptivo, correlacional, retrospectivo, transversal, de asociación. Realizado en el departamento de Managua, en el Hospital Bautista, en el departamento de Medicina Interna y Ortopedia en el periodo de enero 2019 a diciembre 2021. El universo estuvo constituido por pacientes ingresados con diagnóstico de pie diabético en los cuales se realizó aislamiento microbiológico por cultivo de secreciones en el periodo seleccionado. Resultados: Las comorbilidades más frecuentes asociadas fueron la Hipertensión arterial, obesidad y tabaquismo crónico, se evidencio que los años de evolución de la enfermedad (10-20 años), mal control metabólico, presencia de neuropatía periférica y deformaciones mecánicas en pie son importantes factores de riesgo para desarrollo de pie diabético. Se encontró por medio de la prueba de Tau b de Kendall que no existe asociación entre gérmenes aislados y presencia de lesiones severas (ulcera profunda y necrosis). No se evidencio que existiera correlación entre gérmenes aislados y amputaciones mediante prueba de correlación de Pearson. El esquema de tratamiento más utilizado en el estudio fue doble esquema con carbapenémico y glucopéptido. Se utilizo escala de WIFI para valorar severidad. Conclusión: La edad con más prevalencia de pie diabético en nuestro estudio fue mayor de 60 años, predominio masculino. Las pruebas de correlación de Pearson y Tau b de Kendall no encontraron una significancia estadística entre gérmenes aislados y amputaciones, ni gérmenes – lesiones encontrada

Itinerant ferromagnetism in transition metal dichalcogenides moir\'e superlattices

Moir\'e materials are artificial crystals formed at van der Waals heterojunctions that have emerged as a highly tunable platform to realize much of the rich quantum physics of electrons in atomic scale solids, also providing opportunities to discover new quantum phases of matter. Here we use finite-size exact diagonalization methods to explore the physics of single-band itinerant electron ferromagnetism in semiconductor moir\'e materials. We predict where ferromagnetism is likely to occur in triangular-lattice moir\'e systems, and where it is likely to yield the highest Curie temperatures.Comment: 15 pages, 14 figure

Deconstructing Red-Black Trees with Bantling

The refinement of DNS has harnessed access points, and current trends suggest that the improvement of reinforcement learning will soon emerge. Here, authors verify the understanding of web browsers, demonstrates the private importance of cyberinformatics. In order to answer this challenge, we validate that despite the fact that multi-processors and vacuum tubes can synchronize to achieve this mis- sion, vacuum tubes and local-area networks can col- laborate to overcome this question

Lectura de radiografía convencional de tórax

Chest radiography has been one of the most widely used imaging studies for many years as a diagnostic method, hence the importance of knowing how to interpret this study well in daily medical practice. It is important to have an order when observing it and to know the normal anatomical structures in the different projections to be able to recognize pathological data. It must also be remembered that normal structures in children have certain variants on adult radiography.La radiografía de tórax ha sido uno de los estudios de imagen más utilizadas desde hace muchos años como método diagnóstico, de ahí la importancia de saber interpretar bien dicho estudio en la práctica médica diaria. Es importante tener un orden al momento de observarla y conocer las estructuras anatómicas normales en las diferentes proyecciones para poder reconocer datos patológicos. También hay que recordar que las estructuras normales en los niños tienen ciertas variantes a la radiografía del adulto

Purkinje cell loss in experimental autoimmune encephalomyelitis

Gray matter atrophy observed by brain MRI is an important correlate to clinical disability and disease duration in multiple sclerosis. The objective of this study was to link brain atrophy visualized by neuroimaging to its underlying neuropathology using the MS model, experimental autoimmune encephalomyelitis (EAE). Volumetric changes in brains of EAE mice, as well as matched healthy normal controls, were quantified by collecting post-mortem high-resolution T2-weighted magnetic resonance microscopy and actively stained magnetic resonance histology images. Anatomical delineations demonstrated a significant decrease in the volume of the whole cerebellum, cerebellar cortex, and molecular layer of the cerebellar cortex in EAE as compared to normal controls. The pro-apoptotic marker caspase-3 was detected in Purkinje cells and a significant decrease in Purkinje cell number was found in EAE. Cross modality and temporal correlations revealed a significant association between Purkinje cell loss on neuropathology and atrophy of the molecular layer of the cerebellar cortex by neuroimaging. These results demonstrate the power of using combined population atlasing and neuropathology approaches to discern novel insights underlying gray matter atrophy in animal models of neurodegenerative disease

Genetic Overview of the Maya Populations: Mitochondrial DNA Haplogroups

We identified the mitochondrial DNA haplogroups A, B, C and D in 75 present-day Maya individuals, 24 Maya individuals of the colonial period and one pre-Columbian Maya individual from Quintana Roo, Mexico. We examined these data together with those of 21 Maya populations accounting for 647 present-day Maya individuals and 104 ancient Maya individuals. A demographic study based on the analysis of fertility and endogamy was carried out in two modern Maya populations to identify cultural factors that influence the mitochondrial haplogroup genetic diversity. Most present-day and ancient Maya populations show a distribution pattern of mitochondrial haplogroup frequencies A, C, B and D in decreasing order, with haplogroup D absent in several populations. Considering only modern Maya populations with at least 50 individuals analyzed, the present-day Tzotzil and Lacandon populations from Chiapas show the higher and lower genetic diversities, 0.706 and 0.025 respectively. Our results show small genetic differences between the Maya populations with exception of the present-day Tojolabal and Lacandon populations from Chiapas. The present-day Lacandon population from Chiapas is different to other Maya populations in showing almost only haplogroup A. This result suggests a long history of isolation and endogamy as well as a possible founder effect inside the Lacandonian rain-forest. The contemporary Tojolabal population is the only one with an unusual mitochondrial haplogroup pattern exhibiting a frequency of haplogroup B higher than A and the absence of haplogroup C. With a small sample size, the pre-Columbian Copan Maya show a high content of haplogroup C and a low frequency of haplogroup D. The genetic homogeneity of the Maya populations is indicative of a common origin and nearly continuous gene flow in the long-term within a general isolation of the whole group, conversely to the Nahua populations that had different origins. Our demographic study showed high fertility rates and high levels of endogamy in the present-day Maya populations from Quintana Roo here analyzed that are consistent with their general low genetic diversity. We propose that the genetic similarity among ancient and present-day Maya populations persists due to a strong sense of social cohesion and identity that impacts their marriage practices maintaining this cultural group isolated. These factors have constrained gene flow inside the Maya region and impeded the differentiation among the Maya. Discernment of genetic differentiation within the peninsula is constrained by the lack of sampling documentation in the literature

Wind Energy and the Turbulent Nature of the Atmospheric Boundary Layer

Wind turbines operate in the atmospheric boundary layer, where they are exposed to the turbulent atmospheric flows. As the response time of wind turbine is typically in the range of seconds, they are affected by the small scale intermittent properties of the turbulent wind. Consequently, basic features which are known for small-scale homogeneous isotropic turbulence, and in particular the well-known intermittency problem, have an important impact on the wind energy conversion process. We report on basic research results concerning the small-scale intermittent properties of atmospheric flows and their impact on the wind energy conversion process. The analysis of wind data shows strongly intermittent statistics of wind fluctuations. To achieve numerical modeling a data-driven superposition model is proposed. For the experimental reproduction and adjustment of intermittent flows a so-called active grid setup is presented. Its ability is shown to generate reproducible properties of atmospheric flows on the smaller scales of the laboratory conditions of a wind tunnel. As an application example the response dynamics of different anemometer types are tested. To achieve a proper understanding of the impact of intermittent turbulent inflow properties on wind turbines we present methods of numerical and stochastic modeling, and compare the results to measurement data. As a summarizing result we find that atmospheric turbulence imposes its intermittent features on the complete wind energy conversion process. Intermittent turbulence features are not only present in atmospheric wind, but are also dominant in the loads on the turbine, i.e. rotor torque and thrust, and in the electrical power output signal. We conclude that profound knowledge of turbulent statistics and the application of suitable numerical as well as experimental methods are necessary to grasp these unique features (...)Comment: Accepted by the Journal of Turbulence on May 17, 201

Planificación y diseño de una plataforma web para la gestión de procesos de investigación en un sistema integrado de información para la Dirección General de Investigación de la Universidad de San Carlos de Guatemala

Diseñar e implementar una plataforma web que sea utilizada por la DIGI para manejar los procesos de registro de investigadores, registro de evaluadores, realización de propuestas de investigación, contratación de personal para las investigaciones, compras de insumos, compras de equipos, seguimiento de investigación, finalización de investigación y generación de indicadores en forma de reportes que agrupen información de interés, así realizar un análisis del proceso actual para generar un entendimiento y así posteriormente poder automatizarlo por medio de la plataforma y capacitar a los usuarios de DIGI a utilizar la plataforma