3,580 research outputs found
Detection of newborn infants at risk for congenitat toxoplasmosis in Rio de Janeiro, Brazil
Within the third to fifth day after birth, btood samples for indirect immunefluorescence tests (rF) for toxoplasmosis were taken from l0B2 neonates. B?? (36.50/o) rF.rgG and rF-rgM seronegative cases and 65s (68.b%) rF-rgG seropositive cases reacting from 1:16 to 1:1024 were found. rn 1b such cases e.4%), sera were reactive in both the IgG and IgM classes, 12 cases being IF-IgM : 1:16, and B cases IF-I9M - L:64. These cases were considered. at potential risks for congenital infection þy T. gondii. of these 15 cases, a morphological study of 18 placentas showed data suggestive of prolonged fetal injuries in 11 such cases. All these 13 placentas showed signs of hematogenous inflammatory processes. Four placentas revealed structures with morphological characteristics similar to cysts of Toxo. plasma gondii at the microscopical examination. Of these four neonates where the parasite'was found in the placentas, one infant was underweight and showed discrete microcephaly. Two children had hepatosplenomegaþ, one of them with unilateral retinochoroiditis. The fourth case was clinicalþ normal. In the other 11 cases, selected due to possible risk of congenital infection, one infant was pre. mature, eight were normal, and two showed symptomatolog¡r non-suggestive of congenital toxoplasmosis
Strongly anisotropic spin relaxation in graphene/transition metal dichalcogenide heterostructures at room temperature
Graphene has emerged as the foremost material for future two-dimensional
spintronics due to its tuneable electronic properties. In graphene, spin
information can be transported over long distances and, in principle, be
manipulated by using magnetic correlations or large spin-orbit coupling (SOC)
induced by proximity effects. In particular, a dramatic SOC enhancement has
been predicted when interfacing graphene with a semiconducting transition metal
dechalcogenide, such as tungsten disulphide (WS). Signatures of such an
enhancement have recently been reported but the nature of the spin relaxation
in these systems remains unknown. Here, we unambiguously demonstrate
anisotropic spin dynamics in bilayer heterostructures comprising graphene and
WS. By using out-of-plane spin precession, we show that the spin lifetime
is largest when the spins point out of the graphene plane. Moreover, we observe
that the spin lifetime varies over one order of magnitude depending on the spin
orientation, indicating that the strong spin-valley coupling in WS is
imprinted in the bilayer and felt by the propagating spins. These findings
provide a rich platform to explore coupled spin-valley phenomena and offer
novel spin manipulation strategies based on spin relaxation anisotropy in
two-dimensional materials
Counting BPS Operators in Gauge Theories: Quivers, Syzygies and Plethystics
We develop a systematic and efficient method of counting single-trace and
multi-trace BPS operators with two supercharges, for world-volume gauge
theories of D-brane probes for both and finite . The
techniques are applicable to generic singularities, orbifold, toric, non-toric,
complete intersections, et cetera, even to geometries whose precise field
theory duals are not yet known. The so-called ``Plethystic Exponential''
provides a simple bridge between (1) the defining equation of the Calabi-Yau,
(2) the generating function of single-trace BPS operators and (3) the
generating function of multi-trace operators. Mathematically, fascinating and
intricate inter-relations between gauge theory, algebraic geometry,
combinatorics and number theory exhibit themselves in the form of plethystics
and syzygies.Comment: 59+1 pages, 7 Figure
A novel approach to simulate gene-environment interactions in complex diseases
Background: Complex diseases are multifactorial traits caused by both genetic and environmental factors. They represent the major part of human diseases and include those with largest prevalence and mortality (cancer, heart disease, obesity, etc.). Despite a large amount of information that has been collected about both genetic and environmental risk factors, there are few examples of studies on their interactions in epidemiological literature. One reason can be the incomplete knowledge of the power of statistical methods designed to search for risk factors and their interactions in these data sets. An improvement in this direction would lead to a better understanding and description of gene-environment interactions. To this aim, a possible strategy is to challenge the different statistical methods against data sets where the underlying phenomenon is completely known and fully controllable, for example simulated ones.
Results: We present a mathematical approach that models gene-environment interactions. By this method it is possible to generate simulated populations having gene-environment interactions of any form, involving any number of genetic and environmental factors and also allowing non-linear interactions as epistasis. In particular, we implemented a simple version of this model in a Gene-Environment iNteraction Simulator (GENS), a tool designed to simulate case-control data sets where a one gene-one environment interaction influences the disease risk. The main aim has been to allow the input of population characteristics by using standard epidemiological measures and to implement constraints to make the simulator behaviour biologically meaningful.
Conclusions: By the multi-logistic model implemented in GENS it is possible to simulate case-control samples of complex disease where gene-environment interactions influence the disease risk. The user has full control of the main characteristics of the simulated population and a Monte Carlo process allows random variability. A knowledge-based approach reduces the complexity of the mathematical model by using reasonable biological constraints and makes the simulation more understandable in biological terms. Simulated data sets can be used for the assessment of novel statistical methods or for the evaluation of the statistical power when designing a study
Towards the implementation of laser engineered surface structures for electron cloud mitigation
The LHC operation has proven that the electron cloud could be a significant limiting factor in machine performance, in particular for future High Luminosity LHC (HL-LHC) beams. Electron clouds, generated by electron multipacting in the beam pipes, leads to beam instabilities and beam-induced heat load in cryogenic systems. Laser Engineered Surface Structures (LESS) is a novel surface treatment which changes the morphology of the internal surfaces of vacuum chambers. The surface modification results in a reduced secondary electron yield (SEY) and, consequently, in the eradication of the electron multipacting. Low SEY values of the treated surfaces and flexibility in choosing the laser parameters make LESS a promising treatment for future accelerators. LESS can be applied both in new and existing accelerators owing to the possibility of automated in-situ treatment. This approach has been developed and optimised for the LHC beam screens in which the electron cloud has to be mitigated before the HL-LHC upgrade. We will present the latest steps towards the implementation of LESS
Longitudinal differences in the injury profile of professional male handball players according to competitive-level
The aim was to analyze the differences in professional handball players` injury profile according to the team`s competitive-level (i.e., First division vs. Second division). Fifty-three professional male handball players participated in this study during 4 consecutive seasons in the same team (2015-16 and 2016-17 for the First division league and 2017-18 and 2018-19 for the Second division league). No significant differences in overall incidence was observed between groups (3.69 vs 4.19 injuries/1000 h, RR = 0.88, 95% CI 0.64-1.22, P = 0.44), although significantly greater injury incidence during training sessions was observed in the Second division group (3.06 vs 1.61 injuries/1000 h, RR = 0.52, 95% CI 0.34-0.81, P = 0.01), while greater injury incidence during matches was reported in the First division group (84.03 vs 49.88 injuries/1000 h, RR = 1.68, 95% CI 1.00-2.83, P = 0.05). The second division group presented the greatest injury burden attending to overall, training and match exposure, as well as in most locations and injury types, but no statistically significant differences were observed between groups. Given the between groups differences found in the injury profile of handball player, it is suggested to implement specific preventive strategies attending to the characteristics of each level-group
Novel association of high C-reactive protein levels and A69S at risk alleles in wet age-related macular degeneration women
Purpose: To explore the relationship between plasma C-reactive protein (CRP) levels, the main ARMS2 gene single nucleotide polymorphism (SNP), and gender in patients with neovascular age-related macular degeneration (wet AMD).
Methods: Our study included 131 patients with wetAMD [age-related eye disease study (AREDS) category 4] and 153 control participants (AREDS category 1) from two Spanish retinal units. CRP levels were determined on blood samples by high-sensitivity ELISA assay. According to their CRP level, subjects were categorized into three well-established CRP categories: low (3.00 mg/L, H-CRP). Genomic DNA was extracted from oral swabs using QIAcube (Qiagen, Hilden, Germany) and the A69S; rs10490924 of ARMS2 gene was genotyped by allelic discrimination with validated TaqMan assays (Applied Biosystems, Foster City, CA, USA). Univariate and multivariate logistic regression adjusted for age was used to analyze the genomic frequencies and to calculate odds ratio (OR) using SNPStats software.
Results: Considering CRP risk categories, H-CRP group showed a significant [OR 4.0 (1.9-8.3)] association with wetAMD compared to L-CRP group. The risk genotypes of A69S (TT) SNPs showed an association with wetAMD risk [OR 14.0 (4.8-40.8)]. Interestingly, the gender stratification of the CRP categories showed a significant increase in CRP levels in wetAMD women compared with control women [OR 6.9 (2.2-22.3)] and with wetAMD men [OR 4.6 (1.3-16.9)]. In addition, the subgroup analysis of CRP within A69S genotype and gender showed a link in women between the A69S and CRP levels in the AMD group compared to controls [OR 4.2 (1.4-12.6)].
Conclusion: Our study shows, for the first time, that a different genetic association related with gender could contribute to AMD risk. As a consequence, the risk of female gender in the different CRP levels and A69S SNP frequencies could be taken into consideration to the established risk relationship of high levels of CRP and its association with risk A69S genotype
Relationship among medical student resilience, educational environment and quality of life
Resilience is a capacity to face and overcome adversities, with personal transformation and growth. In medical education, it is critical to understand the determinants of a positive, developmental reaction in the face of stressful, emotionally demanding situations. We studied the association among resilience, quality of life (QoL) and educational environment perceptions in medical students. We evaluated data from a random sample of 1,350 medical students from 22 Brazilian medical schools. Information from participants included the Wagnild and Young's resilience scale (RS-14), the Dundee Ready Educational Environment Measure (DREEM), the World Health Organization Quality of Life questionnaire - short form (WHOQOL-BREF), the Beck Depression Inventory (BDI) and the State-Trait Anxiety Inventory (STAI). Full multiple linear regression models were adjusted for sex, age, year of medical course, presence of a BDI score >= 14 and STAI state or anxiety scores >= 50. Compared to those with very high resilience levels, individuals with very low resilience had worse QoL, measured by overall (beta=-0.89; 95% confidence interval =-1.21 to -0.56) and medical-school related (beta=-0.85; 95% CI=-1.25 to -0.45) QoL scores, environment (beta=-6.48; 95% CI=-10.01 to -2.95), psychological (beta=-22.89; 95% CI=-25.70 to -20.07), social relationships (beta=-14.28; 95% CI=-19.07 to -9.49), and physical health (beta=-10.74; 95% CI=-14.07 to -7.42) WHOQOL-BREF domain scores. They also had a worse educational environment perception, measured by global DREEM score (beta=-31.42; 95% CI=-37.86 to -24.98), learning (beta=-7.32; 95% CI=-9.23 to -5.41), teachers (beta=-5.37; 95% CI=-7.16 to -3.58), academic self-perception (beta=-7.33; 95% CI=-8.53 to -6.12), atmosphere (beta=-8.29; 95% CI=-10.13 to -6.44) and social self-perception (beta=-3.12; 95% CI=-4.11 to -2.12) DREEM domain scores. We also observed a dose-response pattern across resilience level groups for most measurements. Medical students with higher resilience levels had a better quality of life and a better perception of educational environment. Developing resilience may become an important strategy to minimize emotional distress and enhance medical training106CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPE
Strong magnetoelastic effect in CeCo1-xFexSi as Néel order is suppressed
A very strong magnetoelastic effect in the CeCo1-xFexSi alloys is reported. The strength of the magnetostrictive effect can be tuned upon changing x. The moderate low-temperature linear magnetostriction observed at low Fe concentrations becomes very large (ΔLL16T,2K=3×10-3) around the critical concentration xc≈0.23 at which the long-range antiferromagnetic order vanishes. Upon increasing doping through the nonmagnetic region (x>xc), the magnetostriction strength gradually weakens again. The interplay between magnetic order and the Kondo screening appears to cause an enhanced valence susceptibility slightly changing the Ce ions valence, ultimately triggering the large magnetostriction observed around the critical concentration. Previous studies of the evolution of the lattice parameters with x as well as magnetization and x-ray absorption spectroscopy measurements support this hypothesis.Fil: Correa, Víctor Félix. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Bajas Temperaturas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Villagrán Asiares, Alberto Gaston. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Bajas Temperaturas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Betancourth Giraldo, Diana Maria. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Bajas Temperaturas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Encina, Sergio. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Bajas Temperaturas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Pedrazzini, Pablo. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Bajas Temperaturas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Cornaglia de la Cruz, Pablo Sebastian. Comisión Nacional de Energía Atómica. Gerencia del Área Investigaciones y Aplicaciones No Nucleares. Gerencia de Física (CAB). Grupo de Teoría de Sólidos; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Garcia, Daniel Julio. Comisión Nacional de Energía Atómica. Gerencia del Área Investigaciones y Aplicaciones No Nucleares. Gerencia de Física (CAB). Grupo de Teoría de Sólidos; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Sereni, Julian Gustavo Renzo. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Bajas Temperaturas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Maiorov, B.. Los Alamos National High Magnetic Field Laboratory; Estados UnidosFil: Caroca Canales, N.. Max planck institut Fur Chemische Physik Fester Stoffe; AlemaniaFil: Geibel, C.. Max planck institut Fur Chemische Physik Fester Stoffe; Alemani
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