1,184 research outputs found
2000 Families: identifying the research potential of an origins - of migration study
Despite extensive recent advances in the empirical and theoretical study of migration, certain critical areas in the analysis of European migration remain relatively underdeveloped both theoretically and empirically. Specifically, we lack studies that both incorporate an origin comparison and trace processes of intergenerational transmission across migrants over multiple generations and incorporating family migration trajectories. This paper outlines the development, data and design of such a study, the 2000 Families study, framed within a theoretical perspective of ?dissimilation? from origins and over generations. We term the study an origins-of-migration study, in that it captures the country of origin, the family origins and potentially the originating causes of migration processes and outcomes. The resulting data comprised nearly 2,000 migrant and non-migrant Turkish families with members across three or more generations, covering. 50,000 individuals. We reflect on the potential of this study for migration research
Optimizing Nervous System-Specific Gene Targeting with Cre Driver Lines: Prevalence of Germline Recombination and Influencing Factors.
The Cre-loxP system is invaluable for spatial and temporal control of gene knockout, knockin, and reporter expression in the mouse nervous system. However, we report varying probabilities of unexpected germline recombination in distinct Cre driver lines designed for nervous system-specific recombination. Selective maternal or paternal germline recombination is showcased with sample Cre lines. Collated data reveal germline recombination in over half of 64 commonly used Cre driver lines, in most cases with a parental sex bias related to Cre expression in sperm or oocytes. Slight differences among Cre driver lines utilizing common transcriptional control elements affect germline recombination rates. Specific target loci demonstrated differential recombination; thus, reporters are not reliable proxies for another locus of interest. Similar principles apply to other recombinase systems and other genetically targeted organisms. We hereby draw attention to the prevalence of germline recombination and provide guidelines to inform future research for the neuroscience and broader molecular genetics communities
Large-Area (over 50 cm × 50 cm) Freestanding Films of Colloidal InP/ZnS Quantum Dots
Cataloged from PDF version of article.We propose and demonstrate the fabrication of flexible, freestanding films of InP/ZnS quantum dots (QDs) using fatty acid ligands across very large areas (greater than 50 cm x 50 cm), which have been developed for remote phosphor applications in solid-state lighting. Embedded in a poly(methyl methacrylate) matrix, although the formation of stand alone films using other QDs commonly capped with trioctylphosphine oxide (TOPO) and oleic acid is not efficient, employing myristic acid as ligand in the synthesis of these QDs, which imparts a strongly hydrophobic character to the thin film, enables film formation and ease of removal even on surprisingly large areas, thereby avoiding the need for ligand exchange. When pumped by a blue LED, these Cd-free QD films allow for high color rendering, warm white light generation with a color rendering index of 89.30 and a correlated color temperature of 2298 K. In the composite film, the temperature-dependent emission kinetics and energy transfer dynamics among different-sized InP/ZnS QDs are investigated and a model is proposed. High levels of energy transfer efficiency (up to 80%) and strong donor lifetime modification (from 18 to 4 ns) are achieved. The suppression of the nonradiative channels is observed when the hybrid film is cooled to cryogenic temperatures. The lifetime changes of the donor and acceptor InP/ZnS QDs in the film as a result of the energy transfer are explained well by our theoretical model based on the exciton-exciton interactions among the dots and are in excellent agreement with the experimental results. The understanding of these excitonic interactions is essential to facilitate improvements in the fabrication of photometrically high quality nanophosphors. The ability to make such large-area, flexible, freestanding Cd-free QD films pave the way for environmentally friendly phosphor applications including flexible, surface-emitting light engines
Systematic study of trace radioactive impurities in candidate construction materials for EXO-200
The Enriched Xenon Observatory (EXO) will search for double beta decays of
136Xe. We report the results of a systematic study of trace concentrations of
radioactive impurities in a wide range of raw materials and finished parts
considered for use in the construction of EXO-200, the first stage of the EXO
experimental program. Analysis techniques employed, and described here, include
direct gamma counting, alpha counting, neutron activation analysis, and
high-sensitivity mass spectrometry.Comment: 32 pages, 6 figures. Expanded introduction, added missing table
entry. Accepted for publication in Nucl. Instrum. Meth.
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Astrocytes refine cortical connectivity at dendritic spines
During cortical synaptic development, thalamic axons must establish synaptic connections despite the presence of the more abundant intracortical projections. How thalamocortical synapses are formed and maintained in this competitive environment is unknown. Here, we show that astrocyte-secreted protein hevin is required for normal thalamocortical synaptic connectivity in the mouse cortex. Absence of hevin results in a profound, long-lasting reduction in thalamocortical synapses accompanied by a transient increase in intracortical excitatory connections. Three-dimensional reconstructions of cortical neurons from serial section electron microscopy (ssEM) revealed that, during early postnatal development, dendritic spines often receive multiple excitatory inputs. Immuno-EM and confocal analyses revealed that majority of the spines with multiple excitatory contacts (SMECs) receive simultaneous thalamic and cortical inputs. Proportion of SMECs diminishes as the brain develops, but SMECs remain abundant in Hevin-null mice. These findings reveal that, through secretion of hevin, astrocytes control an important developmental synaptic refinement process at dendritic spines. DOI: http://dx.doi.org/10.7554/eLife.04047.00
A Large Hadron Electron Collider at CERN
This document provides a brief overview of the recently published report on
the design of the Large Hadron Electron Collider (LHeC), which comprises its
physics programme, accelerator physics, technology and main detector concepts.
The LHeC exploits and develops challenging, though principally existing,
accelerator and detector technologies. This summary is complemented by brief
illustrations of some of the highlights of the physics programme, which relies
on a vastly extended kinematic range, luminosity and unprecedented precision in
deep inelastic scattering. Illustrations are provided regarding high precision
QCD, new physics (Higgs, SUSY) and electron-ion physics. The LHeC is designed
to run synchronously with the LHC in the twenties and to achieve an integrated
luminosity of O(100) fb. It will become the cleanest high resolution
microscope of mankind and will substantially extend as well as complement the
investigation of the physics of the TeV energy scale, which has been enabled by
the LHC
CoRE-ATAC: A deep learning model for the functional classification of regulatory elements from single cell and bulk ATAC-seq data.
Cis-Regulatory elements (cis-REs) include promoters, enhancers, and insulators that regulate gene expression programs via binding of transcription factors. ATAC-seq technology effectively identifies active cis-REs in a given cell type (including from single cells) by mapping accessible chromatin at base-pair resolution. However, these maps are not immediately useful for inferring specific functions of cis-REs. For this purpose, we developed a deep learning framework (CoRE-ATAC) with novel data encoders that integrate DNA sequence (reference or personal genotypes) with ATAC-seq cut sites and read pileups. CoRE-ATAC was trained on 4 cell types (n = 6 samples/replicates) and accurately predicted known cis-RE functions from 7 cell types (n = 40 samples) that were not used in model training (mean average precision = 0.80, mean F1 score = 0.70). CoRE-ATAC enhancer predictions from 19 human islet samples coincided with genetically modulated gain/loss of enhancer activity, which was confirmed by massively parallel reporter assays (MPRAs). Finally, CoRE-ATAC effectively inferred cis-RE function from aggregate single nucleus ATAC-seq (snATAC) data from human blood-derived immune cells that overlapped with known functional annotations in sorted immune cells, which established the efficacy of these models to study cis-RE functions of rare cells without the need for cell sorting. ATAC-seq maps from primary human cells reveal individual- and cell-specific variation in cis-RE activity. CoRE-ATAC increases the functional resolution of these maps, a critical step for studying regulatory disruptions behind diseases
Using Nonlinear Static Procedures for the Seismic Assessment of Irregular RC Buildings
The application of Nonlinear Static Procedures (NSPs) to assess the seismic vulnerability of existing structures
has become widely accepted and extensively used in the literature as well as in engineering practice.
Nevertheless, their success in predicting the response of irregular buildings is not yet fully verified. The main
goal of the present study is to evaluate the capability and accuracy of some of the existing nonlinear static
procedures (N2 and ACSM, in this case) to estimate the seismic performance of irregular structures. In order to
accomplish this objective, four existing buildings, irregular in plan and elevation, were subjected to an extensive
number of nonlinear static and dynamic analyses. The comparisons, focused on both global and local response
parameters provide first indications on the reliability of static procedures to estimate the actual response of
irregular RC buildings.N/
Risk of out-of-hospital cardiac arrest in patients with epilepsy and users of antiepileptic drugs
Aims: A few studies suggested that epilepsy and antiepileptic drugs with sodium channel-blocking properties were independently associated with out-of-hospital cardiac arrest (OHCA). However, these findings have not yet been replicated. Methods: Using Danish registries, we conducted a nested case–control study in a cohort of individuals between 1 June 2001 and 31 December 2015. Cases were defined as OHCA from presumed cardiac causes, and were matched with non-OHCA-controls based on sex, and age on the date of OHCA. Exposure of interest was epilepsy or antiepileptic drug use. To study the association between individual antiepileptic drug use and the rate of OHCA, we compared each antiepileptic drug with valproic acid. Cox regression with time-dependent covariates was conducted to calculate hazard ratio (HR) and 95% confidence interval (CI). Results: We identified 35 195 OHCA-cases and 351 950 matched non-OHCA controls. Epilepsy (cases: 3.58%, controls: 1.60%) was associated with increased rate of OHCA compared with the general population (HR: 1.76, 95%CI: 1.64–1.88) when common OHCA risk factors were taken into account. When we studied antiepileptic drug use, we found that 2 antiepileptic drugs without sodium channel blockage, clonazepam (HR: 1.88, 95%CI: 1.45–2.44) and pregabalin (HR: 1.33, 95%CI: 1.05–1.69), were associated with OHCA, whereas none of the antiepileptic drugs with sodium channel blockage were associated with OHCA. Conclusion: Epilepsy is associated with increased rate of OHCA. Our findings do not support a possible association between antiepileptic drugs with sodium channel-blocking properties and OHCA
A study of a class of p-type equations
In this paper, we give known embedding theorems in Sobolev spaces and Sobolev-Morrey spaces with dominant mixed derivatives. And as an application of the embedding theorems we study the problem of existence, uniqueness and smoothness of solutions of p -type equation
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