409 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

    Adjunctive quetiapine for serotonin reuptake inhibitor-resistant obsessive-compulsive disorder: A meta-analysis of randomised controlled treatment trials

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    Small studies have shown positive effects from adding a variety of antipsychotic agents in patients with obsessive–compulsive disorder who are unresponsive to treatment with serotonin reuptake inhibitors. The evidence, however, is contradictory. This paper reports a meta-analysis of existing double-blind randomized placebo-controlled studies looking at the addition of the second-generation antipsychotic quetiapine in such cases. Three studies fulfilled the inclusion criteria. Altogether 102 individuals were subjected to analysis using Review Manager (4.2.7). The results showed evidence of efficacy for adjunctive quetiapine (< 400 mg/day) on the primary efficacy criterion, measured as changes from baseline in total Yale–Brown Obsessive Compulsive Scale scores (P = 0.008), the clinical significance of which was limited by between-study heterogeneity. The mechanism underlying the effect may involve serotonin and/or dopamine neurotransmission

    Role of serum ADAMTS13 and Von Willebrand Factor (VWF) as early Prognostic Markers in Identifying the Disease Course in Dengue Fever

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    BACKGROUND : Dengue is one of the common illnesses affecting children at Vellore and all over India. A significant proportion of children with dengue fever develop severe dengue including dengue hemorrhagic fever and dengue shock syndrome. Although most cases of severe illness are characterized by plasma leakage, thrombocytopenia and bleeding, the exact pathophysiology is not yet known. There are various proposed theories for causation of severe dengue. The recent evidence shown that in dengue patients there is an acquired deficiency of ADAMTS13 which causes high levels of VWF and subsequently consumptive coagulopathy. This prospective study aims to identify those patients with dengue fever who will progress to severe disease by studying whether levels of two important biomarkers of endothelial cell activation/ dysfunction, viz. VWF and ADAMTS 13 during early illness are predictive of progression to severe dengue and consequent morbidity and mortality. OBJECTIVES : To ascertain the role of ADAMTS13 deficiency and von Willebrand Factor (VWF) excess as early markers in identification of risk of progression to severe dengue in patients with Dengue fever. METHODS : Prospective study correlating levels of ADAMTS13 and VWF among children with dengue during the early febrile phase (day 1-4) with clinical severity and laboratory parameters of severe disease. RESULTS : ADAMTS13 levels were deficient in 96% of study children, irrespective of stage or phase of dengue infection. Von Willebrand Factor (VWF) activity by collagen-binding assay (CBA) was elevated in 89% of children with dengue infection. VWF activity was elevated in severe dengue compared to non-severe dengue, and in the early toxic phase compared to the febrile phase in children with severe dengue. Neither ADAMTS13 nor VWF activity levels were predictive of the WHO clinical stage of severity of dengue infection in our children. Among clinical markers of severity of illness, hepatomegaly, ascites and pleural effusion, bleeding manifestations, need for blood and inotropic support and total duration of hospital stay were all significantly higher in children with severe dengue. Hepatomegaly at admission and need for ICU admission were seen in children with higher median VWF levels. Need for blood support was significantly associated with lower ADAMTS13 levels. CONCLUSIONS : Markers of endothelial injury such as low ADAMTS13 activity and elevated VWF activity are present in all stages and phases of infection in children with dengue. The median levels of ADAMTS13 and VWF activity did not correlate with either the WHO stages of the disease or the phases of the illness, and therefore cannot be used as prognostic biomarkers of severity of illness due to dengue

    Comparative tolerance of Pinus radiata and microbial activity to copper and zinc in a soil treated with metal-amended biosolids

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    A study was conducted to evaluate the effects of elevated concentrations of copper (Cu) and zinc (Zn) in a soil treated with biosolids previously spiked with these metals on Pinus radiata during a 312-day glasshouse pot trial. The total soil metal concentrations in the treatments were 16, 48, 146 and 232 mg Cu/kg or 36, 141, 430 and 668 mg Zn/kg. Increased total soil Cu concentration increased the soil solution Cu concentration (0.03-0.54 mg/L) but had no effect on leaf and root dry matter production. Increased total soil Zn concentration also increased the soil solution Zn concentration (0.9-362 mg/L). Decreased leaf and root dry matter were recorded above the total soil Zn concentration of 141 mg/kg (soil solution Zn concentration, >4.4 mg/L). A lower percentage of Cu in the soil soluble + exchangeable fraction (5-12 %) and lower Cu2+ concentration in soil solution (0.001-0.06 ΌM) relative to Zn (soil soluble + exchangeable fraction, 12-66 %; soil solution Zn2+ concentration, 4.5-4,419 ΌM) indicated lower bioavailability of Cu. Soil dehydrogenase activity decreased with every successive level of Cu and Zn applied, but the reduction was higher for Zn than for Cu addition. Dehydrogenase activity was reduced by 40 % (EC40) at the total solution-phase and solid-phase soluble + exchangeable Cu concentrations of 0.5 mg/L and 14.5 mg/kg, respectively. For Zn the corresponding EC50 were 9 mg/L and 55 mg/kg, respectively. Based on our findings, we propose that current New Zealand soil guidelines values for Cu and Zn (100 mg/kg for Cu; 300 mg/kg for Zn) should be revised downwards based on apparent toxicity to soil biological activity (Cu and Zn) and radiata pine (Zn only) at the threshold concentration. © 2013 Springer-Verlag Berlin Heidelberg

    Diagnostic accuracy of simplified ultrasound hand examination protocols for detection of inflammation and disease burden in patients with rheumatoid arthritis

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    Background: There is no consensus regarding the minimum number of joints that should be included in an ultrasound (US) scoring system to reliably assess for disease activity in rheumatoid arthritis (RA). / Purpose: To assess whether simplified US protocols for hand examination are as informative as the examination of 22 joints in patients with RA, and to correlate the US parameters with disease activity (DAS-28). / Material and Methods: This is a cross-sectional study of 224 RA patients stratified based on their DAS-28 scores and assessed using eight preselected US examination protocols, including 22, 18, 16, 14, ten, eight, and two different combinations of four joints, respectively. / Results: We found a significant difference between US hand scores regarding their ability to detect active inflammation and erosions. DAS-28 scores correlated very well with the power Doppler (PD) scores generated by all eight US examination protocols (r = 0.89–1, P < 0.05), irrespective of patients' disease activity. Simplified US scores missed information on presence of PD in 20.6–40.2% patients (P < 0.05) and misdiagnosed non-erosive hand RA in 12–38.4% patients (P < 0.05), depending on the number of joints excluded from US hand examination. / Conclusion: Preselected simplified US scores are less reliable in appreciating the disease burden when compared with an extended protocol for 22 joint US examination, raising clinicians' awareness regarding the need to comprehensively assess multiple hand joints to reliably rule out subclinical inflammation

    Comparison between Several Ultrasound Hand Joint Scores and Conventional Radiography in Diagnosing Hand Osteoarthritis

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    This is the first study to investigate the usefulness of a standardized ultrasound (US) examination protocol in diagnosing hand osteoarthritis (OA). We conducted a cross-sectional study including 62 patients, ultimately diagnosed with hand OA based on imaging evidence of osteoarthritic changes with the particular distribution required for fulfilment of American College of Radiology diagnosis criteria. We compared a 32-joint US score (wrists, metacarpophalangeal [MCP], proximal interphalangeal [PIP] or distal interphalangeal [DIP] and carpometacarpal [CMC]-1 joints), with smaller, predefined joint scores, assessing 22 joints (wrists, MCPs and PIPs or PIPs, DIPs and CMC-1), 10 joints (MCP 2–3, PIP 2–3 and CMC-1 or PIP 2–3, DIP 2–3 and CMC-1) and 6 joints (DIP 2–3, CMC-1), respectively. The US findings were correlated with radiographic scores for erosions and osteophytes. Radiographic osteophyte scores correlated well with all the US scores mentioned earlier (R = 0.381 to 0.645, p < 0.05), despite low sensitivity for detection of osteophytes (43.5%) and erosions (28.9%), compared with the 32 joint US score. Both 10 joint US protocols (assessing MCP 2–3, PIP 2–3 and CMC-1 or PIP 2–3, DIP 2–3 and CMC-1 joints) performed better than conventional radiography, by identifying osteophytes in an additional 25.6% and 23.9% of patients, respectively. The conclusion of this study is that the US examination of 10 preselected hand joints is more sensitive than conventional radiography in diagnosing hand OA in patients who do not fulfill American College of Radiology clinical criteria, a finding likely to have practical implications for facilitating diagnosis of hand OA

    Ultrasonography-detected subclinical inflammation in patients with hand osteoarthritis and established rheumatoid arthritis: a comparison between two different pathologies using the same ultrasound examination protocol

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    Objectives: A recent review of ultrasound (US) studies in osteoarthritis (OA) showed very limited data about hand OA. Previous US studies in patients with OA described a degree of overlap between the US appearance of rheumatoid arthritis (RA) and OA joints. The present study aimed to assess the US features of subclinical inflammation in RA and hand OA, using the same US examination protocol. / Methods: A retrospective, cohort study compared patients with established RA (n = 224) and hand OA (n = 73), with respect to several demographic, clinical, laboratory and US parameters. We used a 22-hand joint US examination protocol (wrists, metacarpophalangeal and proximal interphalangeal joints bilaterally – Outcome Measures in Rheumatology Clinical Trials [OMERACT] scoring system) for all patients. / Results: Subclinical joint inflammation in the context of equivocal clinical examination was found in 9.6% of OA patients compared with 46.4% of RA patients (p = 0.0001), despite the fact that there was no significant difference between the degree of chronic joint swelling (synovial hypertrophy grades 2 and 3; p = 0.75 and p = 0.11, respectively). The presence of osteophytes was more common in patients with hand OA, as expected (p = 0.0001). / Conclusions: Our study findings reflected differences between the incidence and characteristics of subclinical inflammation in patients with RA and OA, which could be helpful in patients with an equivocal clinical examination or history of both diseases. Almost one in 10 patients with hand OA had active synovitis, while almost one in two patients with RA had uncontrolled inflammation in at least one joint

    Isolation and Characterisation of Genes Encoding Malate Synthesis and Transport Determinants in the Aluminum-Tolerant Australian Weeping-Grass (\u3cem\u3eMicrolaena Stipoides\u3c/em\u3e)

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    Acid soils cover some 40% of the Earth’s arable land where they represent a major limitation to plant production. Plant growth on acid soils is primarily limited due to aluminium (Al) solubilized by acidity into toxic Al3+ cations which will inhibit root growth resulting in poor uptake of water and nutrients. Many important pasture species lack sufficient Al tolerance within their germplasm to allow effective breeding for this character
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