Evaluación de metodologías para recuento de garrapatas en fase de vida parásita = Evaluation of methodologies for counting of ticks in the parasitic life phase

El estudio tuvo como objetivo comparar la exactitud de las pruebas o métodos de recuento de garrapatas ingurgitadas en hembras bovinas criadas bajo sistemas de producción extensiva. Se utilizaron 49 vacas adultas de los genotipos Criollo Ñeembucú, Pardo Suizo, Brangus y Nelore durante el estío en marzo de 2019.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI

El índice Ka: un nuevo algoritmo para analizar los componentes de la superficie terrestre en imágenes de satélite

El cambio del paisaje de la superficie terrestre, su composición y estructura, ocurrido por causas di- versas, ha estado en la mira de toda la humanidad. Se han desarrollado diversas formas para entender- los y la sensoría remota es lo más reciente y nove- doso para tener un conocimiento rápido de gran- des extensiones. En este estudio se ha desarrollado un nuevo algoritmo para medir estos cambios, así como para identificar valores espectrales de espe- cies de coníferas, utilizando imágenes del satélite Landsat7 ETM+. Los resultados muestran un gran potencial del índice Ka para detectar los diferentes componentes superficiales y su variabilidad debi- do a efectos naturales o antropológicos, etc. The change in the landscape of the terrestrial surface, its composition, and its structure, caused by many factors, has been in the aim of all humanity. Diverse forms have been developed in order to understand them, the sensory remote being the most recent and novel thing in acquiring fast knowledge of large extensions. In this study a new algorithm has been developed to measure these changes, as well as to identify ghastly values of coniferous species using images of the satellite Landsat7 ETM+. The results show a great potential of the Ka index in detecting the different superfi- cial components and its variability due to natural effects or due to man

Genome-environment Interaction in type 2 Diabetes Mellitus

Introduction: type 2 diabetes mellitus is the predominant form of diabetes worldwide. It is a heterogeneous syndrome of multifactorial etiology that combines genetic and environmental factors and it is increasingly important due to its morbidity, mortality and disabling effects, which affect the quality of life of those who suffer from it and of their relatives, and due to the use of medical services. Objective: to identify the contribution of the genome-environment interaction in the genesis of type 2 diabetes mellitus in patients of the Puentes Grandes Polyclinic. Methods: an analytical study of population-based case-control was conducted from February 2015 to March 2016 at the Puentes Grandes Polyclinic. Information was obtained from a written questionnaire and the review of individual medical records. We conducted a study that included 60 cases and 120 controls. Results: the existence of familial aggregation in type 2 diabetes mellitus was confirmed, the risk of suffering the disease was 3.6 times higher when a first degree relative was affected and 3.02 times higher when the risk factor of obesity was present and the risk of becoming ill was 14.12 times higher when genetic and environmental factors were overlapped. Conclusions: Type 2 diabetes mellitus is more likely to appear when genetic and environmental factors coincide because it is a multifactorial disease in which the presence of genetic factors is not enough, but the action of a predisposing environment is required to appear.Introducción: la diabetes mellitus tipo 2 presenta una alta prevalencia a nivel mundial. Es un síndrome heterogéneo de etiología multifactorial que combina factores genéticos y ambientales y que cada vez cobra mayor importancia por su morbilidad, su mortalidad y sus efectos incapacitantes, que afectan la calidad de vida de quienes la padecen y de sus familiares, y por el uso de los servicios médicos. Objetivo: identificar la contribución de la interacción genoma-ambiente en la génesis de la diabetes mellitus tipo 2 en pacientes del Policlínico Puentes Grandes. Métodos: se realizó un estudio analítico de casos y controles con base poblacional desde febrero de 2015 a marzo de 2016 en el Policlínico Puentes Grandes. La información se obtuvo por un cuestionario escrito y la revisión de historias clínicas individuales. Se estudiaron 60 casos y 120 controles. Resultados: se constató la presencia de agregación familiar en la diabetes mellitus tipo 2, el riesgo de padecer la enfermedad fue 3,6 veces mayor cuando se tiene un familiar de primer grado afectado y 3,02 veces mayor cuando estuvo presente el factor de riesgo obesidad y el riesgo de enfermar cuando se imbricaban los factores genéticos y ambientales fue 14,12 veces mayor. Conclusiones: existe mayor probabilidad de presentar diabetes mellitus tipo 2 cuando coinciden los factores genéticos y ambientales porque es una enfermedad multifactorial en la que no es suficiente la presencia de factores genéticos, sino que se necesita la acción de un ambiente predisponente para expresarla

Óxido de grafito dopado con diaminomaleonitrilo: efecto en sus propiedades estructurales y eléctricas

Óxido de grafito (OG) y OG dopado con Diaminomaleonitrilo (OGDAMN) fueron nsintetizados por un método de Hummers y se evaluaron sus propiedades eléctricas por voltamperometría cíclica (VC). Los compuestos grafíticos fueron caracterizados por espectroscopia de Infrarrojo (FTIR), Raman, Espectroscopia fotoelectrónica de rayos (XPS) y Microscopia Electrónica de Alta Resolución (HREM). El OGDAMN mostró una mayor histéresis que la de OG en las curvas de VC, así como una mayor capacitancia específica de 138.8 F.g-1, dos veces más para OGDAMN que para OG. Este comportamiento en parte se debió a un cambio en las distancias intercapa relacionado a la formación de grupos imidazol entre los grupos funcionales del OG y DAMN. Las distancias interplanares de OGDAMN obtenida por HREM fueron en promedio de 7.39Å.Graphite oxide (GO) and GO doped with Diaminomaleonitrile (GODAMN) were synthesized by a Hummer's method and their electrical properties were evaluated by cyclic voltammetry (CV). Graphitic compounds were characterized by Infrared Spectroscopy (FTIR), Raman, X-ray photoelectron spectroscopy (XPS) and High Resolution Electron Microscopy (HREM). GODAMN showed a greater hysteresis than GO in the CV curves, as well as a greater specific capacity of 138.8 F.g-1, twice more for GODAMN than for OG. This behaviour was partly due to a change in the interlayer distances associated with an imidazole formation between the functional groups of OG and DAMN. The interplanar distances of OGDAMN obtained by HREM were on average 7.39Å

Exchanging screen for non-screen sitting time or physical activity might attenuate depression and anxiety: A cross-sectional isotemporal analysis during early pandemics in South America

Objectives: To examine the theoretical substitutions of screen exposure, non-screen sitting time, moderate and vigorous physical activity with depressive and anxiety symptoms in South American adults during the COVID-19 pandemic. Design: A cross-sectional study during the first months of the COVID-19 pandemic with data from 1981 adults from Chile, Argentina, and Brazil. Methods: Depressive and anxiety symptoms were assessed using the Beck Depression and Anxiety Inventories. Participants also reported physical activity, sitting time, screen exposure, sociodemographic, and tobacco use data. Isotemporal substitution models were created using multivariable linear regression methods. Results: Vigorous physical activity, moderate physical activity, and screen exposure were independently associated with depression and anxiety symptoms. In adjusted isotemporal substitution models, replacing 10 min/day of either screen exposure or non-screen sitting time with any intensity of physical activity was associated with lower levels of depressive symptoms. Improvements in anxiety symptoms were found when reallocating either screen exposure or non-screen sitting time to moderate physical activity. Furthermore, replacing 10 min/day of screen exposure with non-screen sitting time was beneficially associated with anxiety (B = − 0.033; 95 % CI = − 0.059, − 0.006) and depression (B = − 0.026; 95 % CI = − 0.050, − 0.002). Conclusions: Replacement of screen exposure with any intensity of physical activity or non-screen sitting time could improve mental health symptoms. Strategies aiming to reduce depressive and anxiety symptoms highlight physical activity promotion. However, future interventions should explore specific sedentary behaviors as some will relate positively while others negatively.Fil: Sadarangani, Kabir P.. Universidad Autónoma de Chile; Chile. Universidad Diego Portales; ChileFil: Schuch, Felipe Barreto. Universidade Federal de Santa Maria; Brasil. Universidad Autónoma de Chile; ChileFil: de Roia, Gabriela Fernanda. Universidad de Flores. Laboratorio de Estudios en Actividad Física;Fil: Martínez Gomez, David. Universidad Autónoma de Madrid; España. Consejo Superior de Investigaciones Científicas; España. Consortium for Biomedical Research in Epidemiology and Public Health; EspañaFil: Chávez, Róbinson. Universidad Andrés Bello; ChileFil: Lobo, Pablo Roberto. Universidad de Flores. Laboratorio de Estudios en Actividad Física;Fil: Cristi Montero, Carlos. Pontificia Universidad Católica de Valparaíso; ChileFil: Werneck, André O.. Universidade de Sao Paulo; BrasilFil: Alzahrani, Hosam. Taif University; Arabia SauditaFil: Ferrari, Gerson. Universidad de Santiago de Chile; ChileFil: Ibañez, Agustin Mariano. Universidad de San Andrés; Argentina. University of California; Estados Unidos. Trinity College Dublin; Irlanda. Universidad Adolfo Ibañez; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Silva, Danilo R.. Universidade Federal de Sergipe; Brasil. Universidad Pablo de Olavide; EspañaFil: Von Oetinger, Astrid. Universidad Diego Portales; Chile. Universidad Mayor; ChileFil: Matias, Thiago S.. Universidade Federal de Santa Catarina; BrasilFil: Grabovac, Igor. Universidad de Viena; AustriaFil: Meyer, Jacob. Iowa State University; Estados Unido

Origin of the large dispersion of magnetic properties in nanostructured oxides: FexO/Fe3O4 nanoparticles as a case study

The intimate relationship between stoichiometry and physicochemical properties in transition-metal oxides makes them appealing as tunable materials. These features become exacerbated when dealing with nanostructures. However, due to the complexity of nanoscale materials, establishing a distinct relationship between structure-morphology and functionalities is often complicated. In this regard, in the FexO/Fe3O4 system a largely unexplained broad dispersion of magnetic properties has been observed. Here we show, thanks to a comprehensive multi-technique approach, a clear correlation between the magneto-structural properties in large (45 nm) and small (9 nm) FexO/Fe3O4 core/shell nanoparticles that can explain the spread of magnetic behaviors. The results reveal that while the FexO core in the large nanoparticles is antiferromagnetic and has bulk-like stoichiometry and unit-cell parameters, the FexO core in the small particles is highly non-stoichiometric and strained, displaying no significant antiferromagnetism. These results highlight the importance of ample characterization to fully understand the properties of nanostructured metal oxides

Search for CP Violation in the Decay Z -> b (b bar) g

About three million hadronic decays of the Z collected by ALEPH in the years 1991-1994 are used to search for anomalous CP violation beyond the Standard Model in the decay Z -> b \bar{b} g. The study is performed by analyzing angular correlations between the two quarks and the gluon in three-jet events and by measuring the differential two-jet rate. No signal of CP violation is found. For the combinations of anomalous CP violating couplings, ${\hat{h}}_b = {\hat{h}}_{Ab}g_{Vb}-{\hat{h}}_{Vb}g_{Ab}$ and $h^{\ast}_b = \sqrt{\hat{h}_{Vb}^{2}+\hat{h}_{Ab}^{2}}$, limits of \hat{h}_b < 0.59$and$h^{\ast}_{b} < 3.02$ are given at 95\% CL.Comment: 8 pages, 1 postscript figure, uses here.sty, epsfig.st

An RNAi in silico approach to find an optimal shRNA cocktail against HIV-1

<p>Abstract</p> <p>Background</p> <p>HIV-1 can be inhibited by RNA interference <it>in vitro </it>through the expression of short hairpin RNAs (shRNAs) that target conserved genome sequences. <it>In silico </it>shRNA design for HIV has lacked a detailed study of virus variability constituting a possible breaking point in a clinical setting. We designed shRNAs against HIV-1 considering the variability observed in naïve and drug-resistant isolates available at public databases.</p> <p>Methods</p> <p>A Bioperl-based algorithm was developed to automatically scan multiple sequence alignments of HIV, while evaluating the possibility of identifying dominant and subdominant viral variants that could be used as efficient silencing molecules. Student t-test and Bonferroni Dunn correction test were used to assess statistical significance of our findings.</p> <p>Results</p> <p>Our <it>in silico </it>approach identified the most common viral variants within highly conserved genome regions, with a calculated free energy of ≥ -6.6 kcal/mol. This is crucial for strand loading to RISC complex and for a predicted silencing efficiency score, which could be used in combination for achieving over 90% silencing. Resistant and naïve isolate variability revealed that the most frequent shRNA per region targets a maximum of 85% of viral sequences. Adding more divergent sequences maintained this percentage. Specific sequence features that have been found to be related with higher silencing efficiency were hardly accomplished in conserved regions, even when lower entropy values correlated with better scores. We identified a conserved region among most HIV-1 genomes, which meets as many sequence features for efficient silencing.</p> <p>Conclusions</p> <p>HIV-1 variability is an obstacle to achieving absolute silencing using shRNAs designed against a consensus sequence, mainly because there are many functional viral variants. Our shRNA cocktail could be truly effective at silencing dominant and subdominant naïve viral variants. Additionally, resistant isolates might be targeted under specific antiretroviral selective pressure, but in both cases these should be tested exhaustively prior to clinical use.</p