178 research outputs found
The role of surface-based representations of shape in visual object recognition
This study contrasted the role of surfaces and volumetric shape primitives in three-dimensional object recognition. Observers (N�=�50) matched subsets of closed contour fragments, surfaces, or volumetric parts to whole novel objects during a whole�part matching task. Three factors were further manipulated: part viewpoint (either same or different between component parts and whole objects), surface occlusion (comparison parts contained either visible surfaces only, or a surface that was fully or partially occluded in the whole object), and target�distractor similarity. Similarity was varied in terms of systematic variation in nonaccidental (NAP) or metric (MP) properties of individual parts. Analysis of sensitivity (d�) showed a whole�part matching advantage for surface-based parts and volumes over closed contour fragments�but no benefit for volumetric parts over surfaces. We also found a performance cost in matching volumetric parts to wholes when the volumes showed surfaces that were occluded in the whole object. The same pattern was found for both same and different viewpoints, and regardless of target�distractor similarity. These findings challenge models in which recognition is mediated by volumetric part-based shape representations. Instead, we argue that the results are consistent with a surface-based model of high-level shape representation for recognition
Criteria for the use of omics-based predictors in clinical trials.
The US National Cancer Institute (NCI), in collaboration with scientists representing multiple areas of expertise relevant to 'omics'-based test development, has developed a checklist of criteria that can be used to determine the readiness of omics-based tests for guiding patient care in clinical trials. The checklist criteria cover issues relating to specimens, assays, mathematical modelling, clinical trial design, and ethical, legal and regulatory aspects. Funding bodies and journals are encouraged to consider the checklist, which they may find useful for assessing study quality and evidence strength. The checklist will be used to evaluate proposals for NCI-sponsored clinical trials in which omics tests will be used to guide therapy
Encoding optimization for quantum machine learning demonstrated on a superconducting transmon qutrit
Qutrits, three-level quantum systems, have the advantage of potentially
requiring fewer components than the typically used two-level qubits to
construct equivalent quantum circuits. This work investigates the potential of
qutrit parametric circuits in machine learning classification applications. We
propose and evaluate different data-encoding schemes for qutrits, and find that
the classification accuracy varies significantly depending on the used
encoding. We therefore propose a training method for encoding optimization that
allows to consistently achieve high classification accuracy. Our theoretical
analysis and numerical simulations indicate that the qutrit classifier can
achieve high classification accuracy using fewer components than a comparable
qubit system. We showcase the qutrit classification using the optimized
encoding method on superconducting transmon qutrits, demonstrating the
practicality of the proposed method on noisy hardware. Our work demonstrates
high-precision ternary classification using fewer circuit elements,
establishing qutrit parametric quantum circuits as a viable and efficient tool
for quantum machine learning applications
Identifying Tightly Regulated and Variably Expressed Networks by Differential Rank Conservation (DIRAC)
A powerful way to separate signal from noise in biology is to convert the molecular data from individual genes or proteins into an analysis of comparative biological network behaviors. One of the limitations of previous network analyses is that they do not take into account the combinatorial nature of gene interactions within the network. We report here a new technique, Differential Rank Conservation (DIRAC), which permits one to assess these combinatorial interactions to quantify various biological pathways or networks in a comparative sense, and to determine how they change in different individuals experiencing the same disease process. This approach is based on the relative expression values of participating genes—i.e., the ordering of expression within network profiles. DIRAC provides quantitative measures of how network rankings differ either among networks for a selected phenotype or among phenotypes for a selected network. We examined disease phenotypes including cancer subtypes and neurological disorders and identified networks that are tightly regulated, as defined by high conservation of transcript ordering. Interestingly, we observed a strong trend to looser network regulation in more malignant phenotypes and later stages of disease. At a sample level, DIRAC can detect a change in ranking between phenotypes for any selected network. Variably expressed networks represent statistically robust differences between disease states and serve as signatures for accurate molecular classification, validating the information about expression patterns captured by DIRAC. Importantly, DIRAC can be applied not only to transcriptomic data, but to any ordinal data type
Consensus Analysis of Whole Transcriptome Profiles from Two Breast Cancer Patient Cohorts Reveals Long Non-Coding RNAs Associated with Intrinsic Subtype and the Tumour Microenvironment.
Long non-coding RNAs (lncRNAs) are emerging as crucial regulators of cellular processes and diseases such as cancer; however, their functions remain poorly characterised. Several studies have demonstrated that lncRNAs are typically disease and tumour subtype specific, particularly in breast cancer where lncRNA expression alone is sufficient to discriminate samples based on hormone status and molecular intrinsic subtype. However, little attempt has been made to assess the reproducibility of lncRNA signatures across more than one dataset. In this work, we derive consensus lncRNA signatures indicative of breast cancer subtype based on two clinical RNA-Seq datasets: the Utah Breast Cancer Study and The Cancer Genome Atlas, through integration of differential expression and hypothesis-free clustering analyses. The most consistent signature is associated with breast cancers of the basal-like subtype, leading us to generate a putative set of six lncRNA basal-like breast cancer markers, at least two of which may have a role in cis-regulation of known poor prognosis markers. Through in silico functional characterization of individual signatures and integration of expression data from pre-clinical cancer models, we discover that discordance between signatures derived from different clinical cohorts can arise from the strong influence of non-cancerous cells in tumour samples. As a consequence, we identify nine lncRNAs putatively associated with breast cancer associated fibroblasts, or the immune response. Overall, our study establishes the confounding effects of tumour purity on lncRNA signature derivation, and generates several novel hypotheses on the role of lncRNAs in basal-like breast cancers and the tumour microenvironment
Interferon-driven alterations of the host’s amino acid metabolism in the pathogenesis of typhoid fever
Enteric fever, caused by Salmonella enterica serovar Typhi, is an important public health problem in resource-limited settings and, despite decades of research, human responses to the infection are poorly understood. In 41 healthy adults experimentally infected with wild-type S. Typhi, we detected significant cytokine responses within 12 h of bacterial ingestion. These early responses did not correlate with subsequent clinical disease outcomes and likely indicate initial host–pathogen interactions in the gut mucosa. In participants developing enteric fever after oral infection, marked transcriptional and cytokine responses during acute disease reflected dominant type I/II interferon signatures, which were significantly associated with bacteremia. Using a murine and macrophage infection model, we validated the pivotal role of this response in the expression of proteins of the host tryptophan metabolism during Salmonella infection. Corresponding alterations in tryptophan catabolites with immunomodulatory properties in serum of participants with typhoid fever confirmed the activity of this pathway, and implicate a central role of host tryptophan metabolism in the pathogenesis of typhoid fever
Sensemaking, sensegiving and absorptive capacity in complex procurements
This study explores and describes i) the nature of knowledge exchange processes at the frontline employee (FLE) level and ii) how FLE sensemaking processes affect buyer firm knowledge management practices in complex procurement contexts. The study utilizes an in-depth case analysis in the mining industry to identify a taxonomy of four buyer sensemaking investment/supplier collaboration profiles, to describe three sensegiving supplier roles (“confidence builders”, “competent collaborators”, and “problem-solvers”) and to explore how these evolve during complex procurement implementation. The study concludes with a conceptual model of the apparent linkages between sensemaking, sensegiving and buyer firm absorptive capacity in complex procurements. This study shows how micro-level (FLE) interactions influence macro-level knowledge integration (absorptive capacity) in the buyer firm. For managers, the study shows how the allocation of time and resources affects FLE-level knowledge exchange, with ultimate effect on buyer firm absorptive capacity
Methylome Analysis and Epigenetic Changes Associated with Menarcheal Age
CAD received funding from EU-Europe aid grant CRIS 2009/223–507.The EPIC cohort is supported by the Europe Against Cancer Program of the European
Commission (SANCO). The individual centres also received funding from: Denmark (Danish Cancer Society); France (Ligue centre le Cancer, Institut Gustave Roussy,
Mutuelle Ge´ne´rale de l’Education Nationale, and Institut National de la Sante´ et de la Recherche Me´dicale (INSERM)); Greece (Hellenic Ministry of Health, the Stavros
Niarchos Foundation and the Hellenic Health Foundation); Germany (German Cancer Aid, German Cancer Research Center, and Federal Ministry of Education and
Research (Grant 01-EA-9401)); Italy (Italian Association for Research on Cancer and the National Research Council); The Netherlands (Dutch Ministry of Public Health,
Welfare and Sports (VWS), Netherlands Cancer Registry (NKR), LK Research Funds, Dutch Prevention Funds, and Dutch ZON (Zorg Onderzoek Nederland), World Cancer
Research Fund (WCRF)); Spain (Health Research Fund (FIS) of the Spanish Ministry of Health (Exp 96/0032) and the participating regional governments and
institutions); Sweden (Swedish Cancer Society, Swedish Scientific Council, and Regional Government of Skane); and the United Kingdom (Cancer Research UK and
Medical Research Council UK and Breast Cancer Campaign). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of
the manuscript
Updated Guidance Regarding The Risk ofAllergic Reactions to COVID-19 Vaccines and Recommended Evaluation and Management: A GRADE Assessment, and International Consensus Approach
This guidance updates 2021 GRADE (Grading of Recommendations Assessment, Development and Evaluation) recommendations regarding immediate allergic reactions following coronavirus disease 2019 (COVID-19) vaccines and addresses revaccinating individuals with first-dose allergic reactions and allergy testing to determine revaccination outcomes. Recent meta-analyses assessed the incidence of severe allergic reactions to initial COVID-19 vaccination, risk of mRNA-COVID-19 revaccination after an initial reaction, and diagnostic accuracy of COVID-19 vaccine and vaccine excipient testing in predicting reactions. GRADE methods informed rating the certainty of evidence and strength of recommendations. A modified Delphi panel consisting of experts in allergy, anaphylaxis, vaccinology, infectious diseases, emergency medicine, and primary care from Australia, Canada, Europe, Japan, South Africa, the United Kingdom, and the United States formed the recommendations. We recommend vaccination for persons without COVID-19 vaccine excipient allergy and revaccination after a prior immediate allergic reaction. We suggest against \u3e 15-minute postvaccination observation. We recommend against mRNA vaccine or excipient skin testing to predict outcomes. We suggest revaccination of persons with an immediate allergic reaction to the mRNA vaccine or excipients be performed by a person with vaccine allergy expertise in a properly equipped setting. We suggest against premedication, split-dosing, or special precautions because of a comorbid allergic history
QoRTs: a comprehensive toolset for quality control and data processing of RNA-Seq experiments
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