509 research outputs found

    Shape information mediating basic- and subordinate-level object recognition revealed by analyses of eye movements.

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    This study examines the kinds of shape features that mediate basic- and subordinate-level object recognition. Observers were trained to categorize sets of novel objects at either a basic (between-families) or subordinate (within-family) level of classification. We analyzed the spatial distributions of fixations and compared them to model distributions of different curvature polarity (regions of convex or concave bounding contour), as well as internal part boundaries. The results showed a robust preference for fixation at part boundaries and for concave over convex regions of bounding contour, during both basic- and subordinate-level classification. In contrast, mean saccade amplitudes were shorter during basic- than subordinate-level classification. These findings challenge models of recognition that do not posit any special functional status to part boundaries or curvature polarity. We argue that both basic- and subordinate-level classification are mediated by object representations. These representations make explicit internal part boundaries, and distinguish concave and convex regions of bounding contour. The classification task constrains how shape information in these representations is used, consistent with the hypothesis that both parts-based, and image-based, operations support object recognition in human vision

    Vascular Territory Image Analysis Using Vessel Encoded Arterial Spin Labeling

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    Clustering of chronic hepatitis B screening intentions in social networks of Moroccan immigrants in the Netherlands

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    Background Early detection, identification, and treatment of chronic hepatitis B through screening is vital for those at increased risk, e.g. born in hepatitis B endemic countries. In the Netherlands, Moroccan immigrants show low participation rates in health-related screening programmes. Since social networks influence health behaviour, we investigated whether similar screening intentions for chronic hepatitis B cluster within social networks of Moroccan immigrants. Methods We used respondent-driven sampling (RDS) where each participant ("recruiter") was asked to complete a questionnaire and to recruit three Moroccans ("recruitees") from their social network. Logistic regression analyses were used to analyse whether the recruiters' intention to request a screening test was similar to the intention of their recruitees. Results We sampled 354 recruiter-recruitee pairs: for 154 pairs both participants had a positive screening intention, for 68 pairs both had a negative screening intention, and the remaining 132 pairs had a discordant intention to request a screening test. A tie between a recruiter and recruitee was associated with having the same screening intention, after correction for sociodemographic variables (OR 1.70 [1.15-2.51]). Conclusions The findings of our pilot study show clustering of screening intention among individuals in the same network. This provides opportunities for social network interventions to encourage participation in hepatitis B screening initiatives

    Mechanistic models enable the rational use of in vitro drug-target binding kinetics for better drug effects in patients.

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    INTRODUCTION\nDrug-target binding kinetics are major determinants of the time course of drug action for several drugs, as clearly described for the irreversible binders omeprazole and aspirin. This supports the increasing interest to incorporate newly developed high-throughput assays for drug-target binding kinetics in drug discovery. A meaningful application of in vitro drug-target binding kinetics in drug discovery requires insight into the relation between in vivo drug effect and in vitro measured drug-target binding kinetics.\nAREAS COVERED\nIn this review, the authors discuss both the relation between in vitro and in vivo measured binding kinetics and the relation between in vivo binding kinetics, target occupancy and effect profiles.\nEXPERT OPINION\nMore scientific evidence is required for the rational selection and development of drug-candidates on the basis of in vitro estimates of drug-target binding kinetics. To elucidate the value of in vitro binding kinetics measurements, it is necessary to obtain information on system-specific properties which influence the kinetics of target occupancy and drug effect. Mathematical integration of this information enables the identification of drug-specific properties which lead to optimal target occupancy and drug effect in patients.Pharmacolog

    An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics

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    For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types

    Reducing nutrients, organic micropollutants, antibiotic resistance, and toxicity in rural wastewater effluent with subsurface filtration treatment technology

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    The ability of a sub-surface treatment filtration system to remove nutrients, thirty-nine organic contaminants, metals, and antibiotic resistant gene (ARG)-bearing organisms, and to attenuate acute toxicity of wastewater lagoon effluents, was assessed. Significant removal was observed for nutrients between the conventional primary and secondary sewage lagoons, with further average attenuation of 59% and 50% of ammonia and total phosphorus (TP), respectively, within the filter. Effluent concentrations of ammonia ranged from 0.4 to 2.6mg/L and concentrations of TP from 1 to 4.1mg/L, with decreasing acute toxicity from primary to secondary lagoons, and no toxicity observed in the filtration system based on Microtox® assays. Most organic micropollutants were also efficiently removed between the primary and secondary lagoons (e.g., up to 98% for atenolol). However, in general, little attenuation occurred within the filter for estrogenic compounds (e.g., 17α-ethinylestradiol); β-blockers (e.g., metoprolol); antidepressants (e.g., fluoxetine-Prozac); antibacterial agents (e.g., triclosan), non-steroidal anti-inflammatory drugs (e.g., diclofenac); lipid regulators (e.g., clofibric acid); and macrolide (e.g., clarithromycin) and sulfonamide (e.g., sulfamethazine) antibiotics; or metals (Cr, Cu, Fe, Mn, Ni, and Zn). This lack of removal was likely due to a minimal hydraulic residence time within the filter (~6h) under current operating conditions. The lagoon treatment system effectively removed ~99% of sulfonamide resistant bacteria, but the filter both reduced tetracycline-resistant bacteria (~58%) in wastewater and harbored them in the biofilms, as relative abundances of sul and tet genes were greatest there. The filter also harbored nitrifying and denitrifying bacteria, respectively, contributing to N removal. These results suggest that the constructed sub-surface treatment filtration system can provide a low-cost, low-maintenance, and effective means to reduce nutrient loading and improve microbial community structure and function
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