Differential-thermal analysis around and below the critical temperature Tc of various low-Tc superconductors: A comparative study

We present specific-heat data on the type-II superconductors V3Si, LuNi2B2C and NbSe2 which were acquired with a low-temperature thermal analysis (DTA) technique. We compare our data with available literature data on these superconductors. In the first part we show that the DTA technique allows for fast measurements while providing a very high resolution on the temperature scale. Sharp features in the specific heat such as at the one at the transition to superconductivity are resolved virtually without instrumental broadening. In the second part we investigate the magnetic-field dependence of the specific heats of V3Si and LuNi2B2C at a fixed temperature T=7.5K to demonstrate that DTA techniques also allow for sufficiently precise measurements of absolute values of cp even in the absence of a sharp phase transition. The corresponding data for V3Si and LuNi2B2C are briefly discussed

Thermal expansion, heat capacity and magnetostriction of RAl3_3 (R = Tm, Yb, Lu) single crystals

We present thermal expansion and longitudinal magnetostriction data for cubic RAl3 (R = Tm, Yb, Lu) single crystals. The thermal expansion coefficient for YbAl3 is consistent with an intermediate valence of the Yb ion, whereas the data for TmAl3 show crystal electric field contributions and have strong magnetic field dependencies. de Haas-van Alphen-like oscillations were observed in the magnetostriction data of YbAl3 and LuAl3, several new extreme orbits were measured and their effective masses were estimated. Zero and 140 kOe specific heat data taken on both LuAl3 and TmAl3 for T < 200 K allow for the determination of a CEF splitting scheme for TmAl3

Distinct Mechanisms of Pathogenic DJ-1 Mutations in Mitochondrial Quality Control

The deglycase and chaperone protein DJ-1 is pivotal for cellular oxidative stress responses and mitochondrial quality control. Mutations in PARK7, encoding DJ-1, are associated with early-onset familial Parkinson’s disease and lead to pathological oxidative stress and/or disrupted protein degradation by the proteasome. The aim of this study was to gain insights into the pathogenic mechanisms of selected DJ-1 missense mutations, by characterizing protein–protein interactions, core parameters of mitochondrial function, quality control regulation via autophagy, and cellular death following dopamine accumulation. We report that the DJ-1M26I mutant influences DJ-1 interactions with SUMO-1, in turn enhancing removal of mitochondria and conferring increased cellular susceptibility to dopamine toxicity. By contrast, the DJ-1D149A mutant does not influence mitophagy, but instead impairs Ca2+ dynamics and free radical homeostasis by disrupting DJ-1 interactions with a mitochondrial accessory protein known as DJ-1-binding protein (DJBP/EFCAB6). Thus, individual DJ-1 mutations have different effects on mitochondrial function and quality control, implying mutation-specific pathomechanisms converging on impaired mitochondrial homeostasis

Re-evaluating the resource potential of lomas fog oasis environments for Preceramic hunter-gatherers under past ENSO modes on the south coast of Peru

Lomas – ephemeral seasonal oases sustained by ocean fogs – were critical to ancient human ecology on the desert Pacific coast of Peru: one of humanity’s few independent hearths of agriculture and “pristine” civilisation. The role of climate change since the Late Pleistocene in determining productivity and extent of past lomas ecosystems has been much debated. Here we reassess the resource potential of the poorly studied lomas of the south coast of Peru during the long Middle Pre-ceramic period (c. 8,000 – 4,500 BP): a period critical in the transition to agriculture, the onset of modern El Niño Southern Oscillation (‘ENSO’) conditions, and eustatic sea-level rise and stabilisation and beach progradation. Our method combines vegetation survey and herbarium collection with archaeological survey and excavation to make inferences about both Preceramic hunter-gatherer ecology and the changed palaeoenvironments in which it took place. Our analysis of newly discovered archaeological sites – and their resource context – show how lomas formations defined human ecology until the end of the Middle Preceramic Period, thereby corroborating recent reconstructions of ENSO history based on other data. Together, these suggest that a five millennia period of significantly colder seas on the south coast induced conditions of abundance and seasonal predictability in lomas and maritime ecosystems, that enabled Middle Preceramic hunter-gatherers to reduce mobility by settling in strategic locations at the confluence of multiple eco-zones at the river estuaries. Here the foundations of agriculture lay in a Broad Spectrum Revolution that unfolded, not through population pressure in deteriorating environments, but rather as an outcome of resource abundance.We thank the Ministerio de Cultural del Perú for granting permission for archaeological fieldwork (Resolución Directoral Nº 933-2012-DGPC-VMPCIC/MC, 19 December 2012 and Nº 386-2014-DGPA-VMPCIC/MC, 22 August 2014) and the export of samples for dating; Don Alberto Benavides Ganoza and the people of Samaca for facilitating fieldwork; the Leverhulme Trust (grant number RPG-117) and the late Don Alberto Benavides de la Quintana (grant number RG69428) and the McDonald Institute for Archaeological Research for funding Cambridge University’s One River Archaeological Project, and the NERC Radiocarbon facility (grant number NF/2013/2/2) for funding radiocarbon dating. We also thank the Servicio Nacional Forestal y de Fauna Silvestre (SERFOR) and the Servicio Nacional de Áreas Naturales Protegidas por el Estado (SERNANP), Peru for permits for the Proyecto Kew Perú to carry out botanical and ecological survey, and Delsy Trujillo, Eric Ramírez, Consuelo Borda and other participants of the Proyecto Kew Perú: Conservación, Restauración de Hábitats y Medios de Vida Útiles, Ica, Peru.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.quascirev.2015.10.02

Exploiting protein flexibility to predict the location of allosteric sites

Background: Allostery is one of the most powerful and common ways of regulation of protein activity. However, for most allosteric proteins identified to date the mechanistic details of allosteric modulation are not yet well understood. Uncovering common mechanistic patterns underlying allostery would allow not only a better academic understanding of the phenomena, but it would also streamline the design of novel therapeutic solutions. This relatively unexplored therapeutic potential and the putative advantages of allosteric drugs over classical active-site inhibitors fuel the attention allosteric-drug research is receiving at present. A first step to harness the regulatory potential and versatility of allosteric sites, in the context of drug-discovery and design, would be to detect or predict their presence and location. In this article, we describe a simple computational approach, based on the effect allosteric ligands exert on protein flexibility upon binding, to predict the existence and position of allosteric sites on a given protein structure. Results: By querying the literature and a recently available database of allosteric sites, we gathered 213 allosteric proteins with structural information that we further filtered into a non-redundant set of 91 proteins. We performed normal-mode analysis and observed significant changes in protein flexibility upon allosteric-ligand binding in 70% of the cases. These results agree with the current view that allosteric mechanisms are in many cases governed by changes in protein dynamics caused by ligand binding. Furthermore, we implemented an approach that achieves 65% positive predictive value in identifying allosteric sites within the set of predicted cavities of a protein (stricter parameters set, 0.22 sensitivity), by combining the current analysis on dynamics with previous results on structural conservation of allosteric sites. We also analyzed four biological examples in detail, revealing that this simple coarse-grained methodology is able to capture the effects triggered by allosteric ligands already described in the literature. Conclusions: We introduce a simple computational approach to predict the presence and position of allosteric sites in a protein based on the analysis of changes in protein normal modes upon the binding of a coarse-grained ligand at predicted cavities. Its performance has been demonstrated using a newly curated non-redundant set of 91 proteins with reported allosteric properties. The software developed in this work is available upon request from the authors

TE-Polarized Bessel-Beam Launchers for Wireless Power Transfer at Millimeter Waves: Theory, Design, and Experimental Validation

Transverse-electric (TE) polarized Bessel-beam launchers working at millimeter-wave frequencies are theoretically described, simulated, realized, and experimentally validated. A limited-diffractive near-field distribution up to the so-called nondiffractive-range distance of about 30 mm has been obtained in this work. To generate a pure TE leaky mode, avoiding undesired transverse-magnetic (TM) field components, an innovative feeding scheme is designed consisting of a circular array of four radial slots. To enhance compactness, the four slots are excited through a single-port meandered microstrip feeding network, which has been optimized to ensure the same signal distribution exciting the slots while minimizing unwanted coupling among them. Full-wave simulations allowed for accurately designing a resonant cavity at 30 GHz able to generate a TE-polarized Bessel beam (BB). Two launchers of this kind are then exploited to create a wireless power transfer (WPT) link whose performance is first computed numerically and then verified by means of measurements for different transmitter-receiver distances, namely 25, 35, and 48 mm. These values respectively fall within, in proximity of, and away from the nondiffractive region of the transmitting (TX) device, showing an increasing WPT performance deterioration, as expected. For the case of a 25-mm distance, the evaluated |S21| is - 12 dB, in excellent agreement between full-wave and measurement results

EFECTO DE PROTECT - IT® PARA EL CONTROL DEL GORGOJO, SITOPHILUS ZEA MAIS EN MAÍZ ALMACENADO / EFFECT OF PROTECT - IT® FOR THE CONTROL OF WEEVIL, SITOPHILUS ZEA MAIS IN STORED CORN

El gorgojo del Maíz (Sitophilus zeamais (M) es considerada una de las plagas más importantes que afectan el maíz almacenado, por esto, el objetivo de la presente investigación fue determinar el efecto que ejerce la tierra de diatomea (Protect - It®) sobre el control de esta plaga. Los tratamientos evaluados fueron: Tierra de diatomea a dosis de 0.2, 0.5, 1.0, 2.0, y 3.0, g kg-1 de semilla, Actellic 50 CE a 0.5 mL por kg-1 de semilla y un testigo. Se usó un diseño completamente al azar con siete tratamientos y cuatro repeticiones y la variable de respuesta, porcentaje de mortalidad y germinación de semilla. La mortalidad de los insectos se determinó en cada unidad experimental con una frecuencia de 7, 14, 21, 30 días después de la aplicación con tierra de diatomea (Protect - It®). Los resultados indican que el porcentaje de mortalidad promedio en las evaluaciones registradas a los 30 días fue de 85, 98.7, 100 %; para las dosis de de 0.2, 0.5, 1.0, 2.0, y 3.0, g kg-1 de tierra de diatomea a los 7, 14, 21 y 30 días respectivamente. La tierra de diatomea no afectó la germinación de maíz cuando fueron tratadas con una dosis de 0.5 g kg-1 de semillas

Serie de Redacción Científica: Estudio de Cohortes

Objetive. The cohort study is an observational design. This only includes participants who have the same risk of being exposed, then compares who is exposed and unexposed presents the outcome of interest during the same period. The temporality between the exposure and the outcome of interest in a cohort study is well defined because it is certain that the exposure antecedent to the outcome of interest. Cohort studies can be prospective, retrospective, or a combination of both. One of the main advantages is its longitudinal nature, making it possible to estimate the incidence and relative risk as an association of interest. Some variables may vary over time, so it is essential to use advanced data modeling techniques such as fixed and random effects models.Objetivo. El estudio de cohortes es un diseño de tipo observacional. Este diseño solo incluye participantes que tienen el mismo riesgo de estar expuestos, para luego comparar quienes de los expuestos y no expuestos presentarán el desenlace de interés durante el mismo periodo de tiempo. La temporalidad entre la exposición y el resultado de interés en un estudio de cohorte está bien definida porque se tiene certeza de que la exposición antecede al resultado de interés. Los estudios de cohorte pueden ser prospectivos, retrospectivos o una combinación de ambos. Una de las principales ventajas es su naturaleza longitudinal, lo que permiten estimar la incidencia y el riesgo relativo como asociación de interés. Algunas variables pueden variar en el tiempo por lo que es importante, utilizar técnicas de modelamiento de datos avanzados como los modelos de efectos fijos y aleatorios

Prototipo de estimulador muscular superficial multicanal controlado remotamente

Multichannel Functional Electrical Stimulation (FES) technology is widely employed in artificial motor control research. This study presents the design and evaluation of a four-channel, remotely controlled surface electrical muscle stimulator prototype. The prototype introduces a modern alternative for the control block, employing a Wi-Fi-enabled solution based on the ESP32 microcontroller. This controller enables remote configuration of activation sequences for individual channels and supports extensive customization of parameters for a biphasic waveform stimulus. The current signal is demultiplexed into four outputs. Additionally, this study provides a detailed functional evaluation of the amplification stage and examines the load-dependent limitations of the output current magnitude. Preliminary experimental testing demonstrates the prototype\u27s ability to generate controlled stimulation sequences in hand muscles. The prototype\u27s functional and experimental performance suggests its potential application in artificial motor control research.La tecnología de estimulación eléctrica funcional (EEF) multicanal se utiliza actualmente en la investigación del control motor artificial. Este trabajo describe el diseño y evaluación de un prototipo de estimulador eléctrico muscular de cuatro canales controlado remotamente. El prototipo propone una alternativa moderna para el bloque de control, utilizando el microcontrolador wifi/ESP32. Este permite una secuencia de activación de canales configurable de manera remota y una extensiva configuración de los parámetros de un estímulo en forma de onda bifásica. La señal de corriente se demultiplexa en cuatro salidas. Este estudio también contribuye detallando la evaluación funcional de la etapa de amplificación y estableciendo la dependencia de la magnitud de la carga en los límites de la corriente de salida. La prueba experimental preliminar demuestra la capacidad del prototipo para generar secuencias de estimulación controladas en los músculos de la mano. El desempeño funcional y experimental del prototipo sugiere su potencial uso para investigaciones del control motor artificial

Fibrinogen-to-Albumin Ratio and Blood Urea Nitrogen-to-Albumin Ratio in COVID-19 Patients: A Systematic Review and Meta-Analysis

Fibrinogen-to-albumin ratio (FAR) and blood urea nitrogen-to-albumin ratio (BAR) are inflammatory biomarkers that have been associated with clinical outcomes of multiple diseases. The objective of this study is to evaluate the association of these biomarkers with the severity and mortality of COVID-19 patients. A systematic search was performed in five databases. Observational studies that reported the association between FAR and BAR values with the severity and mortality of COVID-19 patients were included. Random-effects models were used for meta-analyses, and effects were expressed as Odds Ratio (OR) and their 95% confidence intervals (CI). Publication bias was assessed using the Begg test, while the quality assessment was assessed using the Newcastle Ottawa Scale. A total of 21 studies (n = 7949) were included. High FAR values were associated with a higher risk of severity (OR: 2.41; 95% CI 1.41–4.12; p < 0.001) and mortality (OR: 2.05; 95% CI 1.66–2.54; p < 0.001). High BAR values were associated with higher risk of mortality (OR: 4.63; 95% CI 2.11–10.15; p < 0.001). However, no statistically significant association was found between BAR values and the risk of severity (OR: 1.16; 95% CI 0.83–1.63; p = 0.38). High FAR and BAR values were associated with poor clinical outcomes.Revisión por pare