44 research outputs found

    Discrimination of Individual Tigers (\u3cem\u3ePanthera tigris\u3c/em\u3e) from Long Distance Roars

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    This paper investigates the extent of tiger (Panthera tigris) vocal individuality through both qualitative and quantitative approaches using long distance roars from six individual tigers at Omaha\u27s Henry Doorly Zoo in Omaha, NE. The framework for comparison across individuals includes statistical and discriminant function analysis across whole vocalization measures and statistical pattern classification using a hidden Markov model (HMM) with frame-based spectral features comprised of Greenwood frequency cepstral coefficients. Individual discrimination accuracy is evaluated as a function of spectral model complexity, represented by the number of mixtures in the underlying Gaussian mixture model (GMM), and temporal model complexity, represented by the number of sequential states in the HMM. Results indicate that the temporal pattern of the vocalization is the most significant factor in accurate discrimination. Overall baseline discrimination accuracy for this data set is about 70% using high level features without complex spectral or temporal models. Accuracy increases to about 80% when more complex spectral models (multiple mixture GMMs) are incorporated, and increases to a final accuracy of 90% when more detailed temporal models (10-state HMMs) are used. Classification accuracy is stable across a relatively wide range of configurations in terms of spectral and temporal model resolution

    Perceived Transformational Leadership Styles and Job Satisfaction Among Probation Officers

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    As the field of probation service work evolves, so does the role of the probation officer. The problem addressed in this study is that probation officers are experiencing more complexities related to job satisfaction, however there exists limited amount of research on probation leadership and probation officers overall job satisfaction. The purpose of this quantitative study was to investigate whether there is a relationship between the level of job satisfaction of probation officers and supervisors\u27 transformational leadership style. Malsow\u27s hierarchy of need theory and Bass and Avolio\u27s full-range leadership model was utilized as the theoretical framework for the research. The independent variables were (a) Idealized Influence Attributed (IIA), (b) Idealized Influence Behavioral (IIB), (c) Inspirational Motivation (IM), (d) Intellectual Stimulation (IS), and (e) Individualized Consideration (IC). The dependent variable was job satisfaction. The study survey consisting of a demographic questionnaire, Multi-factor Leadership Questionnaire (MLQ), and the Job in General (JIG), questionnaire. One hundred thirty-six probation officers participated in the internet study. Participants were members of the same Professional Association. Spearman\u27s Correlation Statistic and multiple linear regression analyses were performed to test the hypotheses. Findings showed there was a statistically significant, moderate or strong positive correlation between perceived transformational leadership style of the supervisor and self-reported job satisfaction. Implications for positive social change include enhanced knowledge and leadership skills which may aid in producing more positive outcomes on probation officers job satisfaction

    Input-output curves of low and high spontaneous rate auditory nerve fibers are exponential near threshold

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    Input-output (IO) properties of cochlear transduction are frequently determined by analyzing the average discharge rates of auditory nerve fibers (ANFs) in response to relatively long tonal stimulation. The ANFs in cats have spontaneous discharge rates (SRs) that are bimodally distributed, peaking at low (<0.5 spikes/s) and high (∼60 spikes/s) rates, and rate-level characteristics differ depending upon SR. In an effort to assess the instantaneous IO properties of ANFs having different SRs, static IO-curves were constructed from period histograms based on phase-locking of spikes to the stimulus waveform. These curves provide information unavailable in conventional average rate-level curves. We find that all IO curves follow an exponential trajectory. It is argued that the exponential behavior represents the transduction in the IHC and that the difference among ANFs having different SRs is predominantly a difference in gain attributed most likely to synaptic drive

    The very large G-protein coupled receptor VLGR1: a component of the ankle link complex required for the normal development of auditory hair bundles

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    Sensory hair bundles in the inner ear are composed of stereocilia that can be interconnected by a variety of different link types, including tip links, horizontal top connectors, shaft connectors, and ankle links. The ankle link antigen is an epitope specifically associated with ankle links and the calycal processes of photoreceptors in chicks. Mass spectrometry and immunoblotting were used to identify this antigen as the avian ortholog of the very large G-protein-coupled receptor VLGR1, the product of the Usher syndrome USH2C (Mass1) locus. Like ankle links, Vlgr1 is expressed transiently around the base of developing hair bundles in mice. Ankle links fail to form in the cochleae of mice carrying a targeted mutation in Vlgr1 (Vlgr1/del7TM), and the bundles become disorganized just after birth. FM1-43 [N-(3-triethylammonium)propyl)-4-(4-(dibutylamino)styryl) pyridinium dibromide] dye loading and whole-cell recordings indicate mechanotransduction is impaired in cochlear, but not vestibular, hair cells of early postnatal Vlgr1/del7TM mutant mice. Auditory brainstem recordings and distortion product measurements indicate that these mice are severely deaf by the third week of life. Hair cells from the basal half of the cochlea are lost in 2-month-old Vlgr1/del7TM mice, and retinal function is mildly abnormal in aged mutants. Our results indicate that Vlgr1 is required for formation of the ankle link complex and the normal development of cochlear hair bundles

    Lack of Rbl1/p107 Effects on Cell Proliferation and Maturation in the Inner Ear

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    Loss of postnatal mammalian auditory hair cells (HCs) is irreversible. Earlier studies have highlighted the importance of the Retinoblastoma family of proteins (pRBs) (i.e., Rb1, Rbl1/p107, and Rbl2/p130) in the auditory cells’ proliferation and emphasized our lack of information on their specific roles in the auditory system. We have previously demonstrated that lack of Rbl2/p130 moderately affects HCs’ and supporting cells’ (SCs) proliferation. Here, we present evidence supporting multiple roles for Rbl1/p107 in the developing and mature mouse organ of Corti (OC). Like other pRBs, Rbl1/p107 is expressed in the OC, particularly in the Hensen’s and Deiters’ cells. Moreover, Rbl1/p107 impacts maturation and postmitotic quiescence of HCs and SCs, as evidenced by enhanced numbers of these cells and the presence of dividing cells in the postnatal Rbl1/p107−/− OC. These findings were further supported by microarray and bioinformatics analyses, suggesting downregulation of several bHLH molecules, as well as activation of the Notch/Hes/Hey signaling pathway in homozygous Rbl1/p107 mutant mice. Physiological assessments and detection of ectopic HC marker expression in postnatal spiral ganglion neurons (SGNs) provided evidence for incomplete cell maturation and differentiation in Rbl1/p107−/− OC. Collectively, the present study highlights an important role for Rbl1/p107 in OC cell differentiation and maturation, which is distinct from other pRBs

    Incident Sexually Transmitted Infection as a Biomarker for High-Risk Sexual Behavior After Diagnosis of Acute HIV

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    Sexually transmitted infection (STI) diagnosis following diagnosis of acute HIV infection (AHI) indicates ongoing high-risk sexual behavior and possible risk of HIV transmission. We assessed predictors of STI acquisition and the effect of time since care entry on STI incidence in AHI patients in care and receiving consistent risk-reduction messaging

    Antiretroviral Therapy Initiated During Acute HIV Infection Fails to Prevent Persistent T-Cell Activation

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    Initiation of ART during acute HIV-1 infection may prevent persistent immune activation. We analyzed longitudinal CD38+HLA-DR+ CD8+ T cell percentages in 31 acutely infected individuals who started early (median 43 days since infection) and successful ART, and maintained viral suppression through 96 weeks. Pre-therapy a median of 72.6% CD8+ T cells were CD38+HLA-DR+, and while this decreased to 15.6% by 96 weeks, it remained substantially higher than seronegative controls (median 8.9%, p=0.008). Shorter time to suppression predicted lower activation at 96 weeks. These results support the hypothesis that very early events in HIV-1 pathogenesis may result in prolonged immune dysfunction

    Acute HIV-1 Infection in the Southeastern United States: A Cohort Study

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    In 1998 a collaboration between Duke University and the University of North Carolina, Chapel Hill (UNC) was founded to enhance identification of persons with acute HIV-1 infection (AHI). The Duke-UNC AHI Research Consortium Cohort consists of patients ≥18 years old with a positive nucleic acid amplification test (NAAT) and either a negative enzyme immunoassay (EIA) test or a positive EIA with a negative/indeterminate Western blot. Patients were referred to the cohort from acute care settings and state-funded HIV testing sites that use NAAT testing on pooled HIV-1 antibody-negative samples. Between 1998 and 2010, 155 patients with AHI were enrolled: 81 (52%) African-Americans, 63 (41%) white, non-Hispanics, 137 (88%) males, 108 (70%) men who have sex with men (MSM), and 18 (12%) females. The median age was 27 years (IQR 22–38). Most (n=138/155) reported symptoms with a median duration of 17.5 days. The median nadir CD4 count was 408 cells/mm3 (IQR 289–563); the median observed peak HIV-1 level was 726,859 copies/ml (IQR 167,585–3,565,728). The emergency department was the most frequent site of initial presentation (n=55/152; 3 missing data). AHI diagnosis was made at time of first contact in 62/137 (45%; 18 missing data) patients. This prospectively enrolled cohort is the largest group of patients with AHI reported from the Southeastern United States. The demographics reflect the epidemic of this geographic area with a high proportion of African-Americans, including young black MSM. Highlighting the challenges of diagnosing AHI, less than half of the patients were diagnosed at the first healthcare visit. Women made up a small proportion despite increasing numbers in our clinics

    Proceedings of the 3rd Biennial Conference of the Society for Implementation Research Collaboration (SIRC) 2015: advancing efficient methodologies through community partnerships and team science

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    It is well documented that the majority of adults, children and families in need of evidence-based behavioral health interventionsi do not receive them [1, 2] and that few robust empirically supported methods for implementing evidence-based practices (EBPs) exist. The Society for Implementation Research Collaboration (SIRC) represents a burgeoning effort to advance the innovation and rigor of implementation research and is uniquely focused on bringing together researchers and stakeholders committed to evaluating the implementation of complex evidence-based behavioral health interventions. Through its diverse activities and membership, SIRC aims to foster the promise of implementation research to better serve the behavioral health needs of the population by identifying rigorous, relevant, and efficient strategies that successfully transfer scientific evidence to clinical knowledge for use in real world settings [3]. SIRC began as a National Institute of Mental Health (NIMH)-funded conference series in 2010 (previously titled the “Seattle Implementation Research Conference”; $150,000 USD for 3 conferences in 2011, 2013, and 2015) with the recognition that there were multiple researchers and stakeholdersi working in parallel on innovative implementation science projects in behavioral health, but that formal channels for communicating and collaborating with one another were relatively unavailable. There was a significant need for a forum within which implementation researchers and stakeholders could learn from one another, refine approaches to science and practice, and develop an implementation research agenda using common measures, methods, and research principles to improve both the frequency and quality with which behavioral health treatment implementation is evaluated. SIRC’s membership growth is a testament to this identified need with more than 1000 members from 2011 to the present.ii SIRC’s primary objectives are to: (1) foster communication and collaboration across diverse groups, including implementation researchers, intermediariesi, as well as community stakeholders (SIRC uses the term “EBP champions” for these groups) – and to do so across multiple career levels (e.g., students, early career faculty, established investigators); and (2) enhance and disseminate rigorous measures and methodologies for implementing EBPs and evaluating EBP implementation efforts. These objectives are well aligned with Glasgow and colleagues’ [4] five core tenets deemed critical for advancing implementation science: collaboration, efficiency and speed, rigor and relevance, improved capacity, and cumulative knowledge. SIRC advances these objectives and tenets through in-person conferences, which bring together multidisciplinary implementation researchers and those implementing evidence-based behavioral health interventions in the community to share their work and create professional connections and collaborations
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