3,527 research outputs found

    Similarity and dissimilarity as evidence in perceptual categorization

    Get PDF
    In exemplar models the similarities between a new stimulus and each category exemplar constitute positive evidence for category membership. In contrast, other models assume that, if the new stimulus is sufficiently dissimilar to a category member, then that dissimilarity constitutes evidence against category membership. We propose a new similarity–dissimilarity exemplar model that provides a framework for integrating these two types of accounts. The evidence for a category is assumed to be the summed similarity to members of that category plus the summed dissimilarity to members of competing categories. The similarity–dissimilarity exemplar model is shown to mimic the standard exemplar model very closely in the unidimensional domain

    Sequence effects in categorization of simple perceptual stimuli

    Get PDF
    Categorization research typically assumes that the cognitive system has access to a (more or less noisy) representation of the absolute magnitudes of the properties of stimuli and that this information is used in reaching a categorization decision. However, research on identification of simple perceptual stimuli suggests that people have very poor representations of absolute magnitude information and that judgments about absolute magnitude are strongly influenced by preceding material. The experiments presented here investigate such sequence effects in categorization tasks. Strong sequence effects were found. Classification of a borderline stimulus was more accurate when preceded by a distant member of the opposite category than by a distant member of the same category. It is argued that this category contrast effect cannot be accounted for by extant exemplar or decision-bound models of categorization. The effect suggests the use of relative magnitude information in categorization. A memory and contrast model illustrates how relative magnitude information may be used in categorization

    Metabolism impacts upon Candida immunogenicity and pathogenicity at multiple levels

    Get PDF
    Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved. Open Access funded by Wellcome TrustNon peer reviewedPublisher PD

    Grouping Normal Type Ia Supernovae by UV to Optical Color Differences

    Get PDF
    Observations of many SNe Ia with the UVOT instrument on the Swift satellite has revealed that there exists order to the differences in the UV-OPT colors of normal SNe. We examine UV-OPT color curves for 25 SNe Ia, dividing them into 4 groups, finding that ~1/3 of these SNe Ia have bluer UV-OPT colors than the larger group, with these "NUV-blue" SNe Ia 0.4 mag bluer than the "NUV-red" SNe Ia in u-v. Another group of events feature colors similar to NUV-red SNe Ia in the u-v to uvw1-v colors, but similar to the NUV-blue SNe Ia in the uvm2-v color. We name these events "MUV-blue". The last group initially has colors similar to NUV-red SNe Ia, but with color curves that feature more modest changes than the larger NUV-red group. These "irregular" events are comprised of all the NUV-red events with the broadest optical peaks, which leads us to consider this minor group a subset of the NUV-red group. When so separated and the accounting is made for the rapid time evolution of the UV-OPT colors, we find that the scatter in two NUV-OPT colors, u-v & uvw1-v, is at the level of the scatter in b-v. This finding is promising for extending the cosmological utilization of SNe Ia into the NUV. We generate spectrophotometry of SNe Ia that have been observed with HST and argue that there is a fundamental spectral difference in the 2900-3500A wavelength range, a range suggested to be dominated by absorption from iron-peak elements. The NUV-blue SNe Ia feature less NUV absorption than the NUV-red SNe Ia. We show that all the NUV-blue SNe Ia in this sample have also featured evidence of unburned carbon in optical spectra, whereas only one NUV-red SN Ia features that absorption line. Every NUV-blue event also exhibits a low gradient of the SiII 6355A absorption feature, but many NUV-red events also exhibit a low gradient, perhaps suggestive that NUV-blue events are a subset of the larger LVG group.Comment: Accepted to the Astrophysical Journal Updated version: Sept 16, 201

    Treatment of Malignant Fibrous Histiocytoma and Atypical Fibrous Xanthomas with Micrographic Surgery

    Full text link
    Fibrous tumors of the soft tissue are usually benign, but some fibrous neoplasms such as dermatofibrosarcoma protuberans (DFSP), atypical fibroxanthoma (AFX), and malignant fibrohistiocytoma (MFH) can be very destructive locally with a high recurrence rate after local excision. On occasion, they can metastasize. Previous reports have confirmed the high success rate of Mohs micrographic surgery for the treatment of DFSP, but data have been lacking on the potential benefit of this surgical approach for MFH and AFX tumors. Over the past 6 years, we have treated 17 patients with MFH (20 tumors) and 5 patients with AFX with Mohs micrographic surgery. A retrospective analysis of the surgical results is presented. To date (average 3-year follow-up), all patients contacted are tumor free with only one recurrence; no patient has developed metastatic disease. Our results to date are very encouraging; they lend support to Mohs micrographic surgery as a desired surgical approach for these diffiult-to-cure neoplasms.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73298/1/j.1524-4725.1989.tb03149.x.pd

    Candida albicans colonization and dissemination from the murine gastrointestinal tract : the influence of morphology and Th17 immunity

    Get PDF
    This article is protected by copyright. All rights reserved. This work was supported by the Wellcome Trust (086558, 080088, 102705), a Wellcome Trust Strategic Award (097377) and a studentship from the University of Aberdeen. D.K. was supported by grant 5R01AI083344 from the National Institute of Allergy and Infectious Diseases and by a Voelcker Young Investigator Award from the Max and Minnie Tomerlin Voelcker Fund.Peer reviewedPublisher PD

    Cell wall protection by the Candida albicans class I chitin synthases

    Get PDF
    Open Access funded by Medical Research Council Acknowledgments We thank Kevin Mackenzie in the Microscopy and Histology Core Facility (Institute of Medical Sciences, University of Aberdeen), and Donna MacCallum for helpful statistical advice. This work was supported by grants from the Wellcome Trust (0868827 and 080088) including a Wellcome Trust Strategic Award (097377) and an Investigator Award to NG (101873), an MRC New Investigator Award to ML (MR/J008230/1) and a PhD scholarship awarded to KP from the Ministry of Sciences and Technology and Chiang Mai University, Thailand. Author contributions are as follows: KP constructed strains, performed the majority of the experiments, analyzed the data and contributed to the preparation of the manuscript. JA produced Fig. S1 using the data from the phosphoproteomic analysis conducted by SP and AB. NG conceived and designed experiments, analyzed data and commented on drafts of the manuscript. ML constructed strains, conceived, designed and performed experiments, analyzed data and wrote the manuscript.Peer reviewedPublisher PD

    New Clox Systems for rapid and efficient gene disruption in Candida albicans

    Get PDF
    Acknowledgements: We are grateful to Janet Quinn, Lila Kastora, Joanna Potrykus, Michelle Leach, and others for sharing their experiences with the Clox cassettes. We thank Julia Kohler for her kind gift of the NAT1-flipper plasmid pJK863, Claudia Jacob for her advice with In-fusion cloning, and our colleagues in the Aberdeen Fungal Group for numerous stimulating discussions. Data Availability: The authors confirm that all data underlying the findings are fully available without restriction. The sequences of all Clox cassettes are available in GenBank: URA3-Clox (loxP-URA3-MET3p-cre-loxP): GenBank accession number KC999858. NAT1-Clox (loxP-NAT1-MET3p-cre-loxP): GenBank accession number KC999859. LAL (loxP-ARG4-loxP): GenBank accession number DQ015897. LHL (loxP-HIS1-loxP): GenBank accession number DQ015898. LUL (loxP-URA3-loxP): GenBank accession number DQ015899. Funding: This work was supported by the Wellcome Trust (www.wellcome.ac.uk): S.S., F.C.O., N.A.R.G., A.J.P.B. (080088); N.A.R.G., A.J.P.B. (097377). The authors also received support from the European Research Council [http://erc.europa.eu/]: DSC. ERB, AJPB (STRIFE Advanced Grant; C-2009-AdG-249793). The European Commission also provided funding [http://ec.europa.eu/research/fp7]: I.B., A.J.P.B. (FINSysB MC-ITN; PITN-GA-2008-214004). Also the UK Biotechnology and Biological Research Council provided support [www.bbsrc.ac.uk]: N.A.R.G., A.J.P.B. (Research Grant; BB/F00513X/1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD
    corecore