314 research outputs found
Design of the Front End Electronics for the Infrared Camera of JEM-EUSO, and manufacturing and verification of the prototype model
The Japanese Experiment Module (JEM) Extreme Universe Space Observatory
(EUSO) will be launched and attached to the Japanese module of the
International Space Station (ISS). Its aim is to observe UV photon tracks
produced by ultra-high energy cosmic rays developing in the atmosphere and
producing extensive air showers.
The key element of the instrument is a very wide-field, very fast,
large-lense telescope that can detect extreme energy particles with energy
above eV. The Atmospheric Monitoring System (AMS), comprising, among
others, the Infrared Camera (IRCAM), which is the Spanish contribution, plays a
fundamental role in the understanding of the atmospheric conditions in the
Field of View (FoV) of the telescope. It is used to detect the temperature of
clouds and to obtain the cloud coverage and cloud top altitude during the
observation period of the JEM-EUSO main instrument. SENER is responsible for
the preliminary design of the Front End Electronics (FEE) of the Infrared
Camera, based on an uncooled microbolometer, and the manufacturing and
verification of the prototype model. This paper describes the flight design
drivers and key factors to achieve the target features, namely, detector
biasing with electrical noise better than V from Hz to MHz,
temperature control of the microbolometer, from C to C
with stability better than mK over hours, low noise high bandwidth
amplifier adaptation of the microbolometer output to differential input before
analog to digital conversion, housekeeping generation, microbolometer control,
and image accumulation for noise reduction
Phenotypic, morphological, and metabolic characterization of vascular-spheres from human vascular mesenchymal stem cells
The ability to form spheroids under non-adherent conditions is a well-known property of human mesenchymal stem cells (hMSCs), in addition to stemness and multilineage differentiation features. In the present study, we tested the ability of hMSCs isolated from the vascular wall (hVW-MSCs) to grow as spheres, and provide a characterization of this 3D model. hVW-MSCs were isolated from femoral arteries through enzymatic digestion. Spheres were obtained using ultra-low attachment and hanging drop methods. Immunophenotype and pluripotent genes (SOX-2, OCT-4, NANOG) were analyzed by immunocytochemistry and real-time PCR, respectively. Spheres histological and ultrastructural architecture were examined. Cell viability and proliferative capacity were measured using LIVE/DEATH assay and ki-67 proliferation marker. Metabolomic profile was obtained with liquid chromatography–mass spectrometry. In 2D, hVW-MSCs were spindle-shaped, expressed mesenchymal antigens, and displayed mesengenic potential. 3D cultures of hVW-MSCs were CD44+, CD105low, CD90low, exhibited a low propensity to enter the cell cycle as indicated by low percentage of ki-67 expression and accumulated intermediate metabolites pointing to slowed metabolism. The 3D model of hVW-MSCs exhibits stemness, dormancy and slow metabolism, typically observed in stem cell niches. This culture strategy can represent an accurate model to investigate hMSCs features for future clinical applications in the vascular field
Longitudinal Study of Total and Pathogenic Vibrio parahaemolyticus (tdh+ and/or trh+) in Two Natural Extraction Areas of Mytilus chilensis in Southern Chile
Vibrio parahaemolyticus is the leading cause of seafood-associated bacterial gastroenteritis worldwide. Although different studies have focused on its pattern of variation over time, knowledge about the environmental factors driving the dynamics of this pathogen, within the Chilean territory, is still lacking. This study determined the prevalence of total and pathogenic V. parahaemolyticus strains (tdh and/or trh genes) in mussels (Mytilus chilensis) collected from two natural growing areas between 2017 and 2018, using selective agar and PCR analysis. V. parahaemolyticus was detected in 45.6% (93/204) of pooled samples from the Valdivia River Estuary. The pathogenic strains carrying the tdh and/or trh gene were detected in 11.8% (24/204): tdh in 9.8% (20/204), trh in 0.5% (1/204), and 1.5% (3/204) presented both genes. In Reloncaví Fjord, V. parahaemolyticus was detected in 14.4% (30/209) of the samples, pathogenic V. parahaemolyticus carrying the trh gene was detected in 0.5% (1/209) of the samples, while the tdh gene was not detected in the samples from this area. The total count of mauve-purple colonies typical of V. parahaemolyticus on CHROMagar was positively associated by multivariate analysis with area, water temperature, and salinity. Similarly, V. parahaemolyticus detection rates by PCR had a positive correlation with the area and water temperature. The chances of detecting total V. parahaemolyticus in the Valdivia River Estuary are significantly higher than in the Reloncaví Fjord, but inversely, during spring-summer months, the interaction factor between the area and temperature indicated that the chances of detecting V. parahaemolyticus are higher in the Reloncaví Fjord. Interestingly, this period coincides with the season when commercial and natural-growing shellfish are harvested. On the other hand, pathogenic V. parahaemolyticus tdh+ was significantly correlated with an increase of water temperature. These environmental parameters could be used to trigger a warning on potential hazard, which would influence human health and economic losses in aquaculture systems.
Magnetocaloric effect in random magnetic anisotropy materials
In this letter we report the results of entropy variations in random anisotropy magnets composed of TbxY1−xAl2, with x=0.15, 0.20, 0.25, 0.35, 0.40, and 0.50. We discovered large entropy variation associated with the spin glass to paramagnetictransition. Both temperature transition and entropy changes were studied at different temperatures and with different compositions. Our conclusion is that these materials are suitable candidates for use as magnetic refrigerants in a temperature range below 40 K
Modelos de biomasa aérea y subterránea de Hevea brasilienses y Theobroma grandiflorum en la Amazonía colombiana
Biomass models are key tools for estimating carbon in agroecosystems. This research was conducted in Caquetá, Colombia, in plantations and agroforestry systems. A total of 41 trees of Hevea brasiliensis and 40 of Theobroma grandiflorum were sampled to estimate the above-ground biomass (Ab); and 19 and 12 trees, respectively, were excavated to estimate the below-ground biomass (Bb). The models were adjusted based on the determination coefficient (R2), the adjusted R2, and Akaike’s and the Bayesian information criteria. The recommended models for Ab in H. brasiliensis and T. grandiflorum were Ln(Ab)=-2.99+2.72*Ln(DBH) and Ln(Ab)=-2.59+2.48*Ln(D30), respectively (Ab: kg.tree-1; DBH: diameter at breast height in cm; D30: trunk diameter at a 30 cm height). Additionally, models based on diameter and height were developed, as well as others based on the crown area. These models constitute an advancement in improving estimations of biomass and carbon, thus reaching Tier 2 in research and mitigation projects.Los modelos de biomasa son herramientas clave para estimar carbono en agroecosistemas. Esta investigación fue desarrollada en Caquetá, Colombia, en plantaciones y sistemas agroforestales. Se seleccionaron 41 árboles de Hevea brasiliensis y 40 de Theobroma grandiflorum para estimar la biomasa aérea (Ba); y 19 y 12 árboles fueron excavados respectivamente para estimar biomasa subterránea (Bb). Se ajustaron los modelos con base en el coeficiente de determinación (R2), el R2 ajustado, y los criterios de información de Akaike y Bayesiano. Los modelos recomendados para Ba en H. brasiliensis y T. grandiflorum fueron Ln(Ba)=-2.99+2.72*Ln(DAP) y Ln(Ba)=-2.59+2.48*Ln(D30), respectivamente (Ba: kg.árbol-1; DAP: diámetro a la altura del pecho en cm; D30: diámetro del tronco a 30 cm de altura). Adicionalmente, se desarrollaron modelos con base en diámetro y altura, así como otros basados en el área de la copa. Estos modelos son un avance para mejorar las estimaciones de biomasa y carbono, alcanzando un Tier 2 (Nivel 2), en investigación y proyectos de mitigación
Experimental measurement of the quality factor of a Fabry-P\'erot open-cavity axion haloscope
The axion is a hypothetical boson arising from the most natural solution to
the problem of charge and parity symmetry in the strong nuclear force.
Moreover, this pseudoscalar emerges as a dark matter candidate in a parameter
space extending several decades in mass. The Dark-photons \& Axion-Like
particles Interferometer (DALI) is a proposal to search for axion dark matter
in a range that remains under-examined. Currently in a design and prototyping
phase, this haloscope is a multilayer Fabry-P\'erot interferometer. A
proof-of-principle experiment is performed to observe the resonance in a
prototype. The test unveils a quality factor per open cavity of a few hundred
over a bandwidth of the order of dozens of megahertz. The result elucidates a
physics potential to find the, so far elusive, axion, in a sector which can
simultaneously solve the symmetry problem in the strong interaction and the
enigma of dark matter.Comment: 5 pages, 6 figure
Altered developmental programs and oriented cell divisions lead to bulky bones during salamander limb regeneration
There are major differences in duration and scale at which limb development and regeneration proceed, raising the question to what extent regeneration is a recapitulation of development. We address this by analyzing skeletal elements using a combination of micro-CT imaging, molecular profiling and clonal cell tracing. We find that, in contrast to development, regenerative skeletal growth is accomplished based entirely on cartilage expansion prior to ossification, not limiting the transversal cartilage expansion and resulting in bulkier skeletal parts. The oriented extension of salamander cartilage and bone appear similar to the development of basicranial synchondroses in mammals, as we found no evidence for cartilage stem cell niches or growth plate-like structures during neither development nor regeneration. Both regenerative and developmental ossification in salamanders start from the cortical bone and proceeds inwards, showing the diversity of schemes for the synchrony of cortical and endochondral ossification among vertebrates
Cross-sectional study of the association of 5 single nucleotide polymorphisms with enalapril treatment response among South African adults with hypertension
This study investigates the association of 5 single nucleotide polymorphisms (SNPs) in selected genes (ABO, VEGFA, BDKRB2, NOS3, and ADRB2) with blood pressure (BP) response to enalapril. The study further assessed genetic interactions that exist within these genes and their implications in enalapril treatment response among South African adults with hypertension.A total of 284 participants belonging to the Nguni tribe of South Africa on continuous treatment for hypertension were recruited. Five SNPs in enalapril pharmacogenes were selected and genotyped using MassArray. Uncontrolled hypertension was defined as BP ≥140/90 mm Hg. The association between genotypes, alleles, and BP response to treatment was determined by fitting multivariate logistic regression model analysis, and genetic interactions between SNPs were assessed by multifactor dimensionality reduction.Majority of the study participants were female (75.00%), Xhosa (78.87%), and had uncontrolled hypertension (69.37%). All 5 SNPs were exclusively detected among Swati and Zulu participants. In the multivariate (adjusted) logistic model analysis, ADRB2 rs1042714 GC (adjusted odds ratio [AOR] = 2.31; 95% confidence interval [CI] 1.02-5.23; P = .044) and BDKRB2 rs1799722 CT (AOR = 2.74; 95% CI 1.19-6.28; P = .017) were independently associated with controlled hypertension in response to enalapril. While the C allele of VEGFA rs699947 (AOR = 0.37; 95% CI 0.15-0.94; P = .037) was significantly associated with uncontrolled hypertension. A significant interaction between rs699947, rs495828, and rs2070744 (cross-validation consistency = 10/10; P = .0005) in response to enalapril was observed.We confirmed the association of rs1042714 (ADRB2) and rs1799722 (BDKRB2) with controlled hypertension and established an interaction between rs699947 (VEGFA), rs495828 (ABO), and rs2070744 (NOS3) with BP response to enalapril. Our findings have provided substantial evidence for the use of SNPs as predictors for enalapril response among South Africans adults with hypertension. Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc
Obtaining cloud top height from WRF model vertical profiles: application to the EUSO program
The objective of the Extreme Universe Space Observatory (EUSO) program is detection and measurement of high-energy particles that reach earth?s atmosphere from space. Clouds at mid and upper levels of the troposphere can interfere with such detection. Therefore, determining cloud top height with high accuracy is crucial to estimating the effect of clouds on these measurements.With this aim, we developed a method to extract that height using cloud temperature via vertical profiles predicted by the WRF model
The impact of polyphenols on chondrocyte growth and survival: a preliminary report
Background: Imbalances in the functional binding of fibroblast growth factors (FGFs) to their receptors (FGFRs) have consequences for cell proliferation and differentiation that in chondrocytes may lead to degraded cartilage. The toxic, proinflammatory, and oxidative response of cytokines and FGFs can be mitigated by dietary polyphenols.
Objective: We explored the possible effects of polyphenols in the management of osteoarticular diseases using a model based on the transduction of a mutated human FGFR3 (G380R) in murine chondrocytes. This mutation is present in most cases of skeletal dysplasia and is responsible for the overexpression of FGFR3 that, in the presence of its ligand, FGF9, results in toxic effects leading to altered cellular growth.
Design: Different combinations of dietary polyphenols derived from plant extracts were assayed in FGFR3 (G380R) mutated murine chondrocytes, exploring cell survival, chloride efflux, extracellular matrix (ECM) generation, and grade of activation of mitogen-activated protein kinases.
Results: Bioactive compounds from Hibiscus sabdariffa reversed the toxic effects of FGF9 and restored normal growth, suggesting a probable translation to clinical requests in humans. Indeed, these compounds activated the intracellular chloride efflux, increased ECM generation, and stimulated cell proliferation. The inhibition of mitogen-activated protein kinase phosphorylation was interpreted as the main mechanism governing these beneficial effects.
Conclusions: These findings support the rationale behind the encouragement of the development of drugs that repress the overexpression of FGFRs and suggest the dietary incorporation of supplementary nutrients in the management of degraded cartilage.The authors are grateful for the constant support provided by the Hospital Universitari de Sant Joan and the Universitat Rovira i Virgili. Salvador Fernández-Arroyo is the recipient of a Sara Borrell grant (CD12/00672) from the Instituto de Salud Carlos III, Madrid, Spain. The authors also thank the Andalusian Regional Government Council of Innovation and Science for the Excellence Project P11-CTS-7625 and Generalitat Valenciana for the project PROMETEO/2012/007. This work was also supported by projects of the Fundación Areces and the Fundación MAGAR
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