88 research outputs found

    The genetic architecture of the human cerebral cortex

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    INTRODUCTION The cerebral cortex underlies our complex cognitive capabilities. Variations in human cortical surface area and thickness are associated with neurological, psychological, and behavioral traits and can be measured in vivo by magnetic resonance imaging (MRI). Studies in model organisms have identified genes that influence cortical structure, but little is known about common genetic variants that affect human cortical structure. RATIONALE To identify genetic variants associated with human cortical structure at both global and regional levels, we conducted a genome-wide association meta-analysis of brain MRI data from 51,665 individuals across 60 cohorts. We analyzed the surface area and average thickness of the whole cortex and 34 cortical regions with known functional specializations. RESULTS We identified 306 nominally genome-wide significant loci (P < 5 × 10−8) associated with cortical structure in a discovery sample of 33,992 participants of European ancestry. Of the 299 loci for which replication data were available, 241 loci influencing surface area and 14 influencing thickness remained significant after replication, with 199 loci passing multiple testing correction (P < 8.3 × 10−10; 187 influencing surface area and 12 influencing thickness). Common genetic variants explained 34% (SE = 3%) of the variation in total surface area and 26% (SE = 2%) in average thickness; surface area and thickness showed a negative genetic correlation (rG = −0.32, SE = 0.05, P = 6.5 × 10−12), which suggests that genetic influences have opposing effects on surface area and thickness. Bioinformatic analyses showed that total surface area is influenced by genetic variants that alter gene regulatory activity in neural progenitor cells during fetal development. By contrast, average thickness is influenced by active regulatory elements in adult brain samples, which may reflect processes that occur after mid-fetal development, such as myelination, branching, or pruning. When considered together, these results support the radial unit hypothesis that different developmental mechanisms promote surface area expansion and increases in thickness. To identify specific genetic influences on individual cortical regions, we controlled for global measures (total surface area or average thickness) in the regional analyses. After multiple testing correction, we identified 175 loci that influence regional surface area and 10 that influence regional thickness. Loci that affect regional surface area cluster near genes involved in the Wnt signaling pathway, which is known to influence areal identity. We observed significant positive genetic correlations and evidence of bidirectional causation of total surface area with both general cognitive functioning and educational attainment. We found additional positive genetic correlations between total surface area and Parkinson’s disease but did not find evidence of causation. Negative genetic correlations were evident between total surface area and insomnia, attention deficit hyperactivity disorder, depressive symptoms, major depressive disorder, and neuroticism. CONCLUSION This large-scale collaborative work enhances our understanding of the genetic architecture of the human cerebral cortex and its regional patterning. The highly polygenic architecture of the cortex suggests that distinct genes are involved in the development of specific cortical areas. Moreover, we find evidence that brain structure is a key phenotype along the causal pathway that leads from genetic variation to differences in general cognitive function

    Volume I. Introduction to DUNE

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    The preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay—these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. The Deep Underground Neutrino Experiment (DUNE) is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- and dual-phase DUNE liquid argon TPC far detector modules. This TDR is intended to justify the technical choices for the far detector that flow down from the high-level physics goals through requirements at all levels of the Project. Volume I contains an executive summary that introduces the DUNE science program, the far detector and the strategy for its modular designs, and the organization and management of the Project. The remainder of Volume I provides more detail on the science program that drives the choice of detector technologies and on the technologies themselves. It also introduces the designs for the DUNE near detector and the DUNE computing model, for which DUNE is planning design reports. Volume II of this TDR describes DUNE\u27s physics program in detail. Volume III describes the technical coordination required for the far detector design, construction, installation, and integration, and its organizational structure. Volume IV describes the single-phase far detector technology. A planned Volume V will describe the dual-phase technology

    ATLAS detector and physics performance: Technical Design Report, 1

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    Deep Underground Neutrino Experiment (DUNE), far detector technical design report, volume III: DUNE far detector technical coordination

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    The preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay—these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. The Deep Underground Neutrino Experiment (DUNE) is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- and dual-phase DUNE liquid argon TPC far detector modules. Volume III of this TDR describes how the activities required to design, construct, fabricate, install, and commission the DUNE far detector modules are organized and managed. This volume details the organizational structures that will carry out and/or oversee the planned far detector activities safely, successfully, on time, and on budget. It presents overviews of the facilities, supporting infrastructure, and detectors for context, and it outlines the project-related functions and methodologies used by the DUNE technical coordination organization, focusing on the areas of integration engineering, technical reviews, quality assurance and control, and safety oversight. Because of its more advanced stage of development, functional examples presented in this volume focus primarily on the single-phase (SP) detector module

    Highly-parallelized simulation of a pixelated LArTPC on a GPU

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    The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype

    Ensayo a campo de la eficacia de acaricidas comerciales para el control de Varroa destructor (Acari: varroidae)

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    La varroosis, causada por Varroa destructor Anderson & Trueman, es una de las principales parasitosis de Apis mellifera L. El objetivo de este trabajo fue evaluar a campo la eficacia del control otoñal con acaricidas comerciales en el partido de Olavarría (Buenos Aires, Argentina). Se utilizó un diseño completamente aleatorizado con cuatro tratamientos y cinco repeticiones en un apiario en producción: 1- Cumavar®, 2- Amivar®, 3- Wang´s Manpu®, y 4- Testigo. Al final del tratamiento se realizó un tratamiento de "choque" con los dos principios activos diferentes al del tratamiento principal. Se monitoreó la infección de ácaros pre y postratamiento; semanalmente se contaron los ácaros caídos para calcular la eficacia de control porcentual (E) y ajustada (Ea) por la fórmula de Abbott. Los acaricidas evaluados resultaron igualmente eficaces en controlar el ácaro V. destructor cuando fueron comparados al tratamiento testigo. Cumavar® tuvo mayor E y Ea (99,5% y 98,9%, respectivamente), las cuales no difirieron (p<0,05) de las obtenidas con Amivar® (89,2% y 87%, respectivamente). Con Wang¿s Manpu® se obtuvo una E de 78% y no difirió estadísticamente (p<0,05) de la E de los otros acaricidas. Sin embargo, la Ea de Wang¿s Manpu® (74,7%) fue significativamente (p<0,05) diferente de la de Cumavar ®. El volteo con Cumavar® fue superior al 90% del total de ácaros a los 14 días de iniciado el ensayo. Con Amivar® y Wang¿s Manpu® el volteo fue de 70% al cabo del mismo período. Los resultados obtenidos ponen de manifiesto la importancia de evaluar regionalmente los diferentes acaricidas comerciales para considerar sus interacciones con el sitio y detectar posibles casos de ácaros resistentes

    Short-term toxicity of various pharmacological agents on the in vitro nitrification process in a simple closed aquatic system

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    During the treatment of fish diseases, drugs which inhibit the nitrification process can cause acute ammonia toxicity. The same phenomenon can occur when fish are put into a tank without active cultures of nitrifying bacteria. The purpose of this study was to quantify the inhibitory effects of 15 pharmacological agents, which are often used as therapeutic agents in ichthyopathology, on ammonia removal and nitrate production in a simple closed aquatic system. The experiments were conducted in polyethylene bags containing activated biofilters and synthetic water solutions, held in a water bath. Ammonia was added to initiate the nitrification process, and graded concentrations of various pharmacological agents were added. The effects of the pharmacological agents on in vitro nitrification were assessed by monitoring ammonia and nitrate concentrations compared to controls with no added agents, for 24 hours. Graded concentrations of ampicillin (Albipen(R)), chloramine T, enrofloxacin (Baytril(R)), erythromycin, levamisole, methylene blue and polymyxin B induced dose-dependent inhibitions of ammonia removal and nitrate production. The corresponding linear regression curves showed high correlation coefficients and were highly significant (p < 0.05). The addition of chloramphenicol, copper (II) sulphate, kanamycin disulphate, malachite green, neomycin sulphate, potassium penicillin G, tetracycline and a mixture of trimethoprim and sulphadoxin (Duoprim(TM)) had no significant effects on the nitrification process. A significant dose-related inhibition of nitrate production, but not of ammonia oxidation, was observed with enrofloxacin. The significant correlation (r = 0.940; p < 0.001) between the degrees of inhibition of ammonia oxidation and nitrate production for the various inhibitory pharmacological agents has also been calculated, with a view to validating this method. The data presented suggest that separate tank facilities for hospitalisation or quarantine are necessary when treating diseased fish with ampicillin, enrofloxacin, chloramine T, erythromycin, levamisole, methylene blue or polymyxin B, in order to avoid ammonia poisoning
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