109 research outputs found

    Step roughness on Ag(111) investigated by STM: a systematic study of tip influence

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    We have investigated monatomic steps on Ag(111) by STM at different temperatures. At room temperature, the rough appearance of these steps is usually attributed to thermal step fluctuations. We have investigated the influence of the tip systematically. Applying a new test, we demonstrate that even subtle influences can lead to wrong results in statistical analysis

    Label Assistant: A Workflow for Assisted Data Annotation in Image Segmentation Tasks

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    Recent research in the field of computer vision strongly focuses on deep learning architectures to tackle image processing problems. Deep neural networks are often considered in complex image processing scenarios since traditional computer vision approaches are expensive to develop or reach their limits due to complex relations. However, a common criticism is the need for large annotated datasets to determine robust parameters. Annotating images by human experts is time-consuming, burdensome, and expensive. Thus, support is needed to simplify annotation, increase user efficiency, and annotation quality. In this paper, we propose a generic workflow to assist the annotation process and discuss methods on an abstract level. Thereby, we review the possibilities of focusing on promising samples, image pre-processing, pre-labeling, label inspection, or post-processing of annotations. In addition, we present an implementation of the proposal by means of a developed flexible and extendable software prototype nested in hybrid touchscreen/laptop device

    Interphase chromosome positioning in in vitro porcine cells and ex vivo porcine tissues

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    Copyright @ 2012 The Authors. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and 85 reproduction in any medium, provided the original author and source are credited. The article was made available through the Brunel University Open Access Publishing Fund.BACKGROUND: In interphase nuclei of a wide range of species chromosomes are organised into their own specific locations termed territories. These chromosome territories are non-randomly positioned in nuclei which is believed to be related to a spatial aspect of regulatory control over gene expression. In this study we have adopted the pig as a model in which to study interphase chromosome positioning and follows on from other studies from our group of using pig cells and tissues to study interphase genome re-positioning during differentiation. The pig is an important model organism both economically and as a closely related species to study human disease models. This is why great efforts have been made to accomplish the full genome sequence in the last decade. RESULTS: This study has positioned most of the porcine chromosomes in in vitro cultured adult and embryonic fibroblasts, early passage stromal derived mesenchymal stem cells and lymphocytes. The study is further expanded to position four chromosomes in ex vivo tissue derived from pig kidney, lung and brain. CONCLUSIONS: It was concluded that porcine chromosomes are also non-randomly positioned within interphase nuclei with few major differences in chromosome position in interphase nuclei between different cell and tissue types. There were also no differences between preferred nuclear location of chromosomes in in vitro cultured cells as compared to cells in tissue sections. Using a number of analyses to ascertain by what criteria porcine chromosomes were positioned in interphase nuclei; we found a correlation with DNA content.This study is partly supported by Sygen International PLC

    Slope of the superconducting gap function in Bi2Sr2CaCu2O8+δBi_2Sr_2CaCu_2O_{8+\delta} measured by vacuum tunneling spectroscopy

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    Reproducible scanning tunneling microscope (STM) spectra of Bi2Sr2CaCu2O8+δBi_2Sr_2CaCu_2O_{8+\delta} consistently exhibit asymmetric tunneling characteristics, with the higher peak conductance corresponding to a negatively biased sample. We consider various possible sources of this asymmetry that are not intrinsic to the superconducting state, including energy dependence of the normal state densities of states of sample and/or tip, existence of bandwidth cutoffs, unequal work functions of tip and sample, and energy-dependent transmission probability. None of these effects can explain the sign and temperature dependence of the observed asymmetry. This indicates that the observed asymmetry reflects an intrinsic property of the superconducting state: an energy-dependent superconducting gap function with non-zero slope at the Fermi energy. Such a sloped gap function will also give rise to a thermoelectric effect in STM experiments, resulting in a positivepositive thermopower. We discuss the feasibility of observing this thermoelectric effect with an STM and conclude that it is easily observable. An analysis of thermoelectric currents and voltages together with the tunneling spectra as function of temperature and tip- sample distance would allow for accurate determination of the slope of the gap function. It is suggested that it would be very worthwhile to perform these experiments, because the slope of the gap function reflects a fundamental property of the superconducting state. The theory of hole superconductivity has predicted the existence of such a slope, of universal sign, in all superconductors. It is furthermore argued that recent experimental results on vortex lattice imaging provide further strong evidence for the existence of the gap slope discussed here.Comment: Changes from original version: the discussion on Ref. 13 is modified. Publication info: to be published in Phys.Rev.B (May 99) Author's e-mail: [email protected]

    Genome-wide linkage analysis of inguinal hernia in pigs using affected sib pairs

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    BACKGROUND: Inguinal and scrotal hernias are of great concern to pig producers, and lead to poor animal welfare and severe economic loss. Selection against these conditions is highly preferable, but at this time no gene, Quantitative Trait Loci (QTL), or mode of inheritance has been identified in pigs or in any other species. Therefore, a complete genome scan was performed in order to identify genomic regions affecting inguinal and scrotal hernias in pigs. Records from seedstock breeding farms were collected. No clinical examinations were executed on the pigs and there was therefore no distinction between inguinal and scrotal hernias. The genome scan utilised affected sib pairs (ASP), and the data was analysed using both an ASP test based on Non-parametric Linkage (NPL) analysis, and a Transmission Disequilibrium Test (TDT). RESULTS: Significant QTLs (p < 0.01) were detected on 8 out of 19 porcine chromosomes. The most promising QTLs, however, were detected in SSC1, SSC2, SSC5, SSC6, SSC15, SSC17 and SSCX; all of these regions showed either statistical significance with both statistical methods, or convincing significance with one of the methods. Haplotypes from these suggestive QTL regions were constructed and analysed with TDT. Of these, six different haplotypes were found to be differently transmitted (p < 0.01) to healthy and affected pigs. The most interesting result was one haplotype on SSC5 that was found to be transmitted to hernia pigs with four times higher frequency than to healthy pigs (p < 0.00005). CONCLUSION: For the first time in any species, a genome scan has revealed suggestive QTLs for inguinal and scrotal hernias. While this study permitted the detection of chromosomal regions only, it is interesting to note that several promising candidate genes, including INSL3, MIS, and CGRP, are located within the highly significant QTL regions. Further studies are required in order to narrow down the suggestive QTL regions, investigate the candidate genes, and to confirm the suggestive QTLs in other populations. The haplotype associated with inguinal and scrotal hernias may help in achieving selection against the disorder

    A Snapshot of CNVs in the Pig Genome

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    Recent studies of mammalian genomes have uncovered the extent of copy number variation (CNV) that contributes to phenotypic diversity, including health and disease status. Here we report a first account of CNVs in the pig genome covering part of the chromosomes 4, 7, 14, and 17 already sequenced and assembled. A custom tiling oligonucleotide array was used with a median probe spacing of 409 bp for screening 12 unrelated Duroc boars that are founders of a large family material. After a strict CNV calling pipeline, 37 copy number variable regions (CNVRs) across all four chromosomes were identified, with five CNVRs overlapping segmental duplications, three overlapping pig unigenes and one overlapping a RefSeq pig mRNA. This CNV snapshot analysis is the first of its kind in the porcine genome and constitutes the basis for a better understanding of porcine phenotypes and genotypes with the prospect of identifying important economic traits

    The practice of violence risk assessment in Spain

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    Background. Violence risk assessment is a key requirement in professional decision making involving prevention, intervention or reporting on human behavior. The use of structured tools for violence risk assessment has shown to improve the accuracy of assessments based exclusively on clinical judgment or expertise in psychiatric, correctional and legal settings. Objectives. This study presents results of the first survey about professional practices associated with tools for violence risk assessment in Spain. Materials and methods. The information was collected by administering an online-based survey that was distributed by e-mail to members of professional organizations around the country. Results. As in professional contexts worldwide, the Robert Hare’s psychopathy scales (Psychopathy Checklist-Revised and Psychopathy Checklist: Screening Version) and the Historical-Clinical-Risk Management-20 topped the list of the most used tools both by professional choice and institutional requirement. Conclusions. We provide novel data on the prevalence of use and the perceived utility of specific tools, as well as on other issues related to the professional practice of violence risk assessment in Spain, which can guide professional in the health care, correctional and forensic settings, as well as those responsible for decisions in institutions about choosing which tool to implement.Facultad de Ciencias Médica

    The practice of violence risk assessment in Spain

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    Background. Violence risk assessment is a key requirement in professional decision making involving prevention, intervention or reporting on human behavior. The use of structured tools for violence risk assessment has shown to improve the accuracy of assessments based exclusively on clinical judgment or expertise in psychiatric, correctional and legal settings. Objectives. This study presents results of the first survey about professional practices associated with tools for violence risk assessment in Spain. Materials and methods. The information was collected by administering an online-based survey that was distributed by e-mail to members of professional organizations around the country. Results. As in professional contexts worldwide, the Robert Hare’s psychopathy scales (Psychopathy Checklist-Revised and Psychopathy Checklist: Screening Version) and the Historical-Clinical-Risk Management-20 topped the list of the most used tools both by professional choice and institutional requirement. Conclusions. We provide novel data on the prevalence of use and the perceived utility of specific tools, as well as on other issues related to the professional practice of violence risk assessment in Spain, which can guide professional in the health care, correctional and forensic settings, as well as those responsible for decisions in institutions about choosing which tool to implement.Facultad de Ciencias Médica

    The practice of violence risk assessment in Spain

    Get PDF
    Background. Violence risk assessment is a key requirement in professional decision making involving prevention, intervention or reporting on human behavior. The use of structured tools for violence risk assessment has shown to improve the accuracy of assessments based exclusively on clinical judgment or expertise in psychiatric, correctional and legal settings. Objectives. This study presents results of the first survey about professional practices associated with tools for violence risk assessment in Spain. Materials and methods. The information was collected by administering an online-based survey that was distributed by e-mail to members of professional organizations around the country. Results. As in professional contexts worldwide, the Robert Hare’s psychopathy scales (Psychopathy Checklist-Revised and Psychopathy Checklist: Screening Version) and the Historical-Clinical-Risk Management-20 topped the list of the most used tools both by professional choice and institutional requirement. Conclusions. We provide novel data on the prevalence of use and the perceived utility of specific tools, as well as on other issues related to the professional practice of violence risk assessment in Spain, which can guide professional in the health care, correctional and forensic settings, as well as those responsible for decisions in institutions about choosing which tool to implement.Facultad de Ciencias Médica
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