106 research outputs found

    How Will You Share Your Work? Creative Commons Bookmarks and Activity Packet

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    These bookmarks and activity packet were created to teach university students about the Creative Commons during the UWM Libraries\u27 celebration of Open Access Week 2015, October 19-25. The bookmarks provide a quick guide to the Creative Commons licenses and can be printed on colored paper. The activity packet is a Halloween-themed paper doll coloring set that includes public domain and CC-BY materials, as well as a full range of Creative Commons licenses. Through coloring, mixing and matching, and other modifications, students can explore the possibilities of open content, engage in remix culture, and practice attributing the work of others. These materials are licensed under a Creative Commons Attribution 4.0 International License

    Understanding Silent Failures in Medical Image Classification

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    To ensure the reliable use of classification systems in medical applications, it is crucial to prevent silent failures. This can be achieved by either designing classifiers that are robust enough to avoid failures in the first place, or by detecting remaining failures using confidence scoring functions (CSFs). A predominant source of failures in image classification is distribution shifts between training data and deployment data. To understand the current state of silent failure prevention in medical imaging, we conduct the first comprehensive analysis comparing various CSFs in four biomedical tasks and a diverse range of distribution shifts. Based on the result that none of the benchmarked CSFs can reliably prevent silent failures, we conclude that a deeper understanding of the root causes of failures in the data is required. To facilitate this, we introduce SF-Visuals, an interactive analysis tool that uses latent space clustering to visualize shifts and failures. On the basis of various examples, we demonstrate how this tool can help researchers gain insight into the requirements for safe application of classification systems in the medical domain. The open-source benchmark and tool are at: https://github.com/IML-DKFZ/sf-visuals.Comment: Accepted at MICCAI 2

    A Call to Reflect on Evaluation Practices for Failure Detection in Image Classification

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    Reliable application of machine learning-based decision systems in the wild is one of the major challenges currently investigated by the field. A large portion of established approaches aims to detect erroneous predictions by means of assigning confidence scores. This confidence may be obtained by either quantifying the model's predictive uncertainty, learning explicit scoring functions, or assessing whether the input is in line with the training distribution. Curiously, while these approaches all state to address the same eventual goal of detecting failures of a classifier upon real-life application, they currently constitute largely separated research fields with individual evaluation protocols, which either exclude a substantial part of relevant methods or ignore large parts of relevant failure sources. In this work, we systematically reveal current pitfalls caused by these inconsistencies and derive requirements for a holistic and realistic evaluation of failure detection. To demonstrate the relevance of this unified perspective, we present a large-scale empirical study for the first time enabling benchmarking confidence scoring functions w.r.t all relevant methods and failure sources. The revelation of a simple softmax response baseline as the overall best performing method underlines the drastic shortcomings of current evaluation in the abundance of publicized research on confidence scoring. Code and trained models are at https://github.com/IML-DKFZ/fd-shifts

    Operculo-Insular and Anterior Cingulate Plasticity Induced by Transcranial Magnetic Stimulation in the Human Motor Cortex: A Dynamic Casual Modelling Study

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    The ability to induce neuroplasticity with non-invasive brain stimulation techniques offers a unique opportunity to examine the human brain systems involved in pain modulation. In experimental and clinical settings, the primary motor cortex (M1) is commonly targeted to alleviate pain, but its mechanism of action remains unclear. Using dynamic causal modelling (DCM) and Bayesian model selection (BMS), we tested seven competing hypotheses about how TMS modulates the directed influences (or effective connectivity) between M1 and three distinct cortical areas of the medial and lateral pain systems, including the insular (INS), anterior cingulate cortex (ACC), and parietal operculum (PO). The dataset included a novel fMRI acquisition collected synchronously with M1 stimulation during rest and while performing a simple hand motor task. DCM and BMS showed a clear preference for the fully connected model in which all cortical areas receive input directly from M1, with facilitation of the connections INS®M1, PO®M1, and ACC®M1, plus increased inhibition of their reciprocal connections. An additional DCM analysis comparing the reduced models only corresponding to networks with a sparser connectivity within the full model, showed that M1 input into the INS is the second-best model of plasticity following TMS manipulations. The results reported here provide a starting point forinvestigating whether pathway-specific targeting involving M1«INS improves analgesic response beyond conventional targeting. We eagerly await future empirical data and models that tests this hypothesis

    Blind image fusion for hyperspectral imaging with the directional total variation

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    © 2018 IOP Publishing Ltd. Hyperspectral imaging is a cutting-edge type of remote sensing used for mapping vegetation properties, rock minerals and other materials. A major drawback of hyperspectral imaging devices is their intrinsic low spatial resolution. In this paper, we propose a method for increasing the spatial resolution of a hyperspectral image by fusing it with an image of higher spatial resolution that was obtained with a different imaging modality. This is accomplished by solving a variational problem in which the regularization functional is the directional total variation. To accommodate for possible mis-registrations between the two images, we consider a non-convex blind super-resolution problem where both a fused image and the corresponding convolution kernel are estimated. Using this approach, our model can realign the given images if needed. Our experimental results indicate that the non-convexity is negligible in practice and that reliable solutions can be computed using a variety of different optimization algorithms. Numerical results on real remote sensing data from plant sciences and urban monitoring show the potential of the proposed method and suggests that it is robust with respect to the regularization parameters, mis-registration and the shape of the kernel.MJE and C-BS acknowledge support from Leverhulme Trust project 'Breaking the non-convexity barrier', EPSRC grant 'EP/M00483X/1', EPSRC centre 'EP/N014588/1', the Cantab Capital Institute for the Mathematics of Information, and from CHiPS (Horizon 2020 RISE project grant). Moreover, C-BS is thankful for support from the Alan Turing Institute. DAC acknowledges the support of NERC (grant number NE/K016377/1). We are grateful to NERC's Airborne Research Facility and Data Analysis Node for conducting the airborne survey and pre-processing the environmental data collected from Alto Tajo, Spain (survey CAM11/03)

    Screening of DUB activity and specificity by MALDI-TOF mass spectrometry

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    Deubiquitylases (DUBs) are key regulators of the ubiquitin system which cleave ubiquitin moieties from proteins and polyubiquitin chains. Several DUBs have been implicated in various diseases and are attractive drug targets. We have developed a sensitive and fast assay to quantify in vitro DUB enzyme activity using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Unlike other current assays, this method uses unmodified substrates, such as diubiquitin topoisomers. By analyzing 42 human DUBs against all diubiquitin topoisomers we provide an extensive characterization of DUB activity and specificity. Our results confirm the high specificity of many members of the OTU and JAMM DUB families and highlight that all USPs tested display low linkage selectivity. We also demonstrate that this assay can be deployed to assess the potency and specificity of DUB inhibitors by profiling 11 compounds against a panel of 32 DUBs

    The link between rejection sensitivity and borderline personality disorder:A systematic review and meta-analysis

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    OBJECTIVE: People with Borderline Personality Disorder (BPD) may experience heightened rejection sensitivity (RS), a disposition developing from repeated childhood rejecting experiences. It is not known whether the full RS model accounts for the cognitive-affective experiences common in BPD. This systematic review extends upon previous reviews, firstly by assessing the link between childhood rejecting experiences and adult RS, and secondly by considering the link between BPD and RS in both non-clinical and clinical samples.METHOD: Two research questions were devised, and searches based on predetermined criteria were conducted using PsycNET, PubMed, SCOPUS, and Web of Science. Data were extracted by one researcher and 20% was inter-rated, with high levels of agreement. Forty-three papers were systematically reviewed, and 31 included in meta-analysis and meta-regression.RESULTS: Studies assessing the link between childhood rejection and RS are limited; however, emotional abuse and neglect appears linked with RS. Pooled effect sizes suggest RS is linked with BPD (r = .326), with strong effect sizes when comparing clinical and control samples (r = .655). Qualitative synthesis suggests this may be mediated by executive control, although further research is required. The small number of studies considering the full RS model with regard to BPD suggests the interaction between emotional abuse and neglect affects rejection sensitivity; however, outcomes are inconsistent.CONCLUSIONS: Childhood rejection, particularly emotional abuse and neglect, appears to be linked to rejection sensitivity, and rejection sensitivity is linked to BPD. However, this may not be linear. Implications for clinical practice and research are discussed.PRACTITIONER POINTS: Rejection sensitivity is consistently linked with BPD, in clinical and non-clinical samples. Supporting mentalization or improved theory of mind may offer a therapeutic target for this disposition. Considering the causes and effects of rejection sensitivity may offer a non-blaming explanation of interpersonal difficulties in BPD and could be utilized as part of formulation and the therapeutic relationship. However, the possible interaction between emotional abuse and neglect and rejection sensitivity suggests rejection sensitivity is not always apparent for people with BPD. Idiosyncratic formulation should consider this. The literature included in the review is limited to Western populations with a high proportion of females, which may limit generalizability. Measures of rejection sensitivity included in the review were restricted to self-report, which may be subject to bias. Furthermore, measures of childhood rejection were retrospective in nature due to the exclusion of child samples. Further research should consider longitudinal and observational study designs.</p

    Fine Tuning of Globin Gene Expression by DNA Methylation

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    Expression patterns in the globin gene cluster are subject to developmental regulation in vivo. While the γ(A) and γ(G) genes are expressed in fetal liver, both are silenced in adult erythrocytes. In order to decipher the role of DNA methylation in this process, we generated a YAC transgenic mouse system that allowed us to control γ(A) methylation during development. DNA methylation causes a 20-fold repression of γ(A) both in non-erythroid and adult erythroid cells. In erythroid cells this modification works as a dominant mechanism to repress γ gene expression, probably through changes in histone acetylation that prevent the binding of erythroid transcription factors to the promoter. These studies demonstrate that DNA methylation serves as an elegant in vivo fine-tuning device for selecting appropriate genes in the globin locus. In addition, our findings provide a mechanism for understanding the high levels of γ-globin transcription seen in patients with Hereditary Persistence of Fetal Hemoglobin, and help explain why 5azaC and butyrate compounds stimulate γ-globin expression in patients with β-hemoglobinopathies
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