563 research outputs found

    Comparison of VQ and DTW classifiers for speaker verification

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    This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.---- Copyright IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.An investigation into the relative speaker verification performance of various types of vector quantisation (VQ) and dynamic time warping (DTW) classifiers is presented. The study covers a number of algorithmic issues involved in the above classifiers, and examines the effects of these on the verification accuracy. The experiments are based on the use of a subset from the Brent (telephone quality) speech database. This subset consists of repetitions of isolated digit utterances 1 to 9 and zero. The paper describes the experimental work, and presents an analysis of the results

    Open-Set Speaker Identification under Mismatch Conditions

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    Full text of this paper is not available in the UHRA.This paper presents investigations into the performance of open-set, text-independent speaker identification (OSTI-SI) under mismatched data conditions. The scope of the study includes attempts to reduce the adverse effects of such conditions through the introduction of a modified parallel model combination (PMC) method together with condition-adjusted T-Norm (CT-Norm) into the OSTI-SI framework. The experiments are conducted using examples of real world noise. Based on the outcomes, it is demonstrated that the above approach can lead to considerable improvements in the accuracy of open-set speaker identification operating under severely mismatched data conditions. The paper details the realisation of the modified PMC method and CT-Norm in the context of OSTI-SI, presents the experimental investigations and provides an analysis of the results.otherPeer reviewe

    Strategies For Improving Academic Performance By Non-Native English Speakers In Graduate Programs

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    Over the past decade, the number of non-native English speaking students in higher education has increased dramatically. Educators at all levels have experienced challenges in meeting the academic needs of these students and continue to seek strategies for addressing these challenges. This paper describes some of this research related to K-12 and suggests ways for applying the results to improve the academic performance of non-native English speaking students in U.S. graduate programs. Educators in higher education can benefit from the research focused on K-12 and should seek ways to replicate the successful strategies in the graduate classroom

    Threat, Efficacy and Message Framing in Consumer Healthcare

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    Purpose: The purpose of this paper is to empirically examine the interactive effects of message framing, perceived threat and efficacy appeals on attitudes/intentions towards consumer healthcare communications, particularly, cataract surgery. Design/methodology/approach: This paper develops two conceptual models dealing with threat, efficacy and framing and tests them with data collected from two field experiments. Findings: The results reveal that high efficacy messages in combination with high threat or loss-framed messages have a significant positive influence on consumer attitudes and intentions in the consumer healthcare arena. Practical implications: The findings have managerial value and public policy implications for healthcare officials in developing effective communications material. Specifically, this paper recommends that high threat, high efficacy and loss-framed efficacy messages be used. Originality/value: This research extends previous work by demonstrating the effectiveness of threat appeals and framing on consumer attitudes and intentions to undergo cataract surgery. It also demonstrates the use of communication models in the healthcare domain

    Identifying COPD in routinely collected electronic health records: a systematic scoping review

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    Although routinely collected electronic health records (EHRs) are widely used to examine outcomes related to COPD, consensus regarding the identification of cases from electronic healthcare databases is lacking. We systematically examine and summarise approaches from the recent literature. MEDLINE via EBSCOhost was searched for COPD-related studies using EHRs published from January 1, 2018 to November 30, 2019. Data were extracted relating to the case definition of COPD and determination of COPD severity and phenotypes. From 185 eligible studies, we found widespread variation in the definitions used to identify people with COPD in terms of code sets used (with 20 different code sets in use based on the ICD-10 classification alone) and requirement of additional criteria (relating to age (n=139), medication (n=31), multiplicity of events (n=21), spirometry (n=19) and smoking status (n=9)). Only seven studies used a case definition which had been validated against a reference standard in the same dataset. Various proxies of disease severity were used since spirometry results and patient-reported outcomes were not often available. To enable the research community to draw reliable insights from EHRs and aid comparability between studies, clear reporting and greater consistency of the definitions used to identify COPD and related outcome measures is key

    A 2-Dose AERAS-402 Regimen Boosts CD8+ Polyfunctionality in HIV-Negative, BCG-Vaccinated Recipients

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    Despite the widespread use of BCG, tuberculosis (TB) remains a global threat. Existing vaccine candidates in clinical trials are designed to replace or boost BCG which does not provide satisfying long-term protection. AERAS-402 is a replication-deficient Ad35 vaccine encoding a fusion protein of the M. tuberculosis (Mtb) antigens 85A, 85B, and TB10.4. The present phase I trial assessed the safety and immunogenicity of AERAS-402 in participants living in India – a highly TB-endemic area. Healthy male participants aged 18–45 years with a negative QuantiFERON-TB Gold in-tube test (QFT) were recruited. Enrolled participants (n=12) were randomized 2:1 to receive two intramuscular injections of either AERAS-402 (3 x 1010 viral particles [vp]); (n=8) or placebo (n=4) on study days 0 and 28. Safety and immunogenicity parameters were evaluated for up to 182 days post the second injection. Immunogenicity was assessed by a flow cytometry-based intracellular cytokine staining (ICS) assay and transcriptional profiling. The latter was examined using dual-color-Reverse-Transcriptase-Multiplex-Ligation-dependent-Probe-Amplification (dc-RT MLPA) assay. AERAS-402 was well tolerated, and no vaccine-related serious adverse events were recorded. The vaccine-induced CD8+ T-cell responses were dominated by cells co-expressing IFN-Îł, TNF-α, and IL-2 (“polyfunctional” cells) and were more robust than CD4+ T-cell responses. Five genes (CXCL10, GNLY, IFI35, IL1B and PTPRCv2) were differentially expressed between the AERAS-402-group and the placebo group, suggesting vaccine-induced responses. Further, compared to pre-vaccination, three genes (CLEC7A, PTPRCv1 and TAGAP) were consistently up-regulated following two doses of vaccination in the AERAS-402-group. No safety concerns were observed for AERAS-402 in healthy Indian adult males. The vaccine-induced predominantly polyfunctional CD8+ T cells in response to Ag85B, humoral immunity, and altered gene expression profiles in peripheral blood mononuclear cells (PBMCs) indicative of activation of various immunologically relevant biological pathways.publishedVersio

    Perirhinal cortex and the recognition of relative familiarity

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    Spontaneous object recognition (SOR) is a widely used task of recognition memory in rodents which relies on their propensity to explore novel (or relatively novel) objects. Network models typically define perirhinal cortex as a region required for recognition of previously seen objects largely based on findings that lesions or inactivations of this area produce SOR deficits. However, relatively little is understood about the relationship between the activity of cells in the perirhinal cortex that signal novelty and familiarity and the behavioural responses of animals in the SOR task. Previous studies have used objects that are either highly familiar or absolutely novel, but everyday memory is for objects that sit on a spectrum of familiarity which includes objects that have been seen only a few times, or objects that are similar to objects which have been previously experienced. We present two studies that explore cellular activity (through c-fos imaging) within perirhinal cortex of rats performing SOR where the familiarity of objects has been manipulated. Despite robust recognition memory performance, we show no significant changes in perirhinal activity related to the level of familiarity of the objects. Reasons for this lack of familiarity-related modulation in perirhinal cortex activity are discussed. The current findings support emerging evidence that perirhinal responses to novelty are complex and that task demands are critical to the involvement of perirhinal cortex in the control of object recognition memory
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