2,103 research outputs found

    Tribute to Dean Timothy J. Heinsz, A

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    Timothy J. Heinsz, Earl F. Nelson Professor of Law, and Director for the Center for the Study of Dispute Resolution, received his undergraduate degree from St. Louis University and his law degree from Cornell University. He came to the University of Missouri-Columbia School of Law as an associate professor in 1979, and became a full professor in 1981. Between 1988 and 2001, he was dean of the law school. He became Director of the Center for the Study of Dispute Resolution in 2002. On July 2, 2004, Dean Heinsz had a heart attack while jogging on the MKT Trail near his home and died. He was 56 years old. In the days following his death the School of Law received an outpouring of kindness and support from alumni and friends, the legal community, law schools nationwide, and citizens of Columbia. In recognition of his commitment to this law school the editors respectfully dedicate this issue to the memory of Dean Timothy J. Heins

    A classification atlas of stellar spectra of luminosity types III and V for the Burke - Gaffney Observatory

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    1 online resource ( ix, 95 pages) : graphsIncludes abstract and appendix.Includes bibliographical references (page A7).The MK classification system is defined by the spectra of an array of standard stars and is based on the appearances and relative intensities of selected spectral lines, blends, and bands observed in the blue-violet region of the spectrum. In spite of recent studies showing the necessity of revising the system to include an abundance parameter, the MK system remains a two dimensional classification system based on temperature types and luminosity classes. A Spotz spectrograph which was recently acquired by the Burke - Gaffney Observatory, was used after an initial period of testing, to produce a series of spectrograms of selected MK standard stars of luminosity types III and V. The testing was necessary to obtain the correct spectrograph operating settings (camera focus, grating tilt, slit width, and stellar exposure times) and to devise a satisfactory observing procedure for photographing stellar spectra in blue violet wavelength region. the resulting photographic sequence or atlas of spectrograms could then be used at the Burke - Gaffney Observatory to assign MK classifications to other stars. Eleven program stars were employed to test the classification capability and accuracy of the produced atlas. The results proved very satisfactory as in all cases the atlas assigned spectral types were within one subclass of the accepted classifications and nine of the eleven stars were given the correct luminosity classes. Secondary objectives involved the testing of the classification capacity of the spectrograph when using the observatory's Varo image tube and a study of the Halifax night sky spectrum. The reults of the image tube testing indicated that a classification atlas using this apparatus may prove valuable and should be produced. The night sky spectrum of Halifax was heavily marked with emmission lines from mercury and sodium vapour lamps

    Observing Strategies for the Detection of Jupiter Analogs

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    To understand the frequency, and thus the formation and evolution, of planetary systems like our own solar system, it is critical to detect Jupiter-like planets in Jupiter-like orbits. For long-term radial-velocity monitoring, it is useful to estimate the observational effort required to reliably detect such objects, particularly in light of severe competition for limited telescope time. We perform detailed simulations of observational campaigns, maximizing the realism of the sampling of a set of simulated observations. We then compute the detection limits for each campaign to quantify the effect of increasing the number of observational epochs and varying their time coverage. We show that once there is sufficient time baseline to detect a given orbital period, it becomes less effective to add further time coverage-rather, the detectability of a planet scales roughly as the square root of the number of observations, independently of the number of orbital cycles included in the data string. We also show that no noise floor is reached, with a continuing improvement in detectability at the maximum number of observations N = 500 tested here.Peer reviewe

    Cool Jupiters greatly outnumber their toasty siblings : Occurrence rates from the Anglo-Australian Planet Search

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    This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©2019 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.Our understanding of planetary systems different to our own has grown dramatically in the past 30 yr. However, our efforts to ascertain the degree to which the Solar system is abnormal or unique have been hindered by the observational biases inherent to the methods that have yielded the greatest exoplanet hauls. On the basis of such surveys, one might consider our planetary system highly unusual - but the reality is that we are only now beginning to uncover the true picture. In this work, we use the full 18-yr archive of data from the Anglo-Australian Planet Search to examine the abundance of 'cool Jupiters' - analogues to the Solar system's giant planets, Jupiter and Saturn. We find that such planets are intrinsically far more common through the cosmos than their siblings, the hot Jupiters.We find that the occurrence rate of such 'cool Jupiters' is 6.73 +2.09 -1.13 per cent, almost an order of magnitude higher than the occurrence of hot Jupiters (at 0.84 +0.70 -0.20 per cent). We also find that the occurrence rate of giant planets is essentially constant beyond orbital distances of ~1 au. Our results reinforce the importance of legacy radial velocity surveys for the understanding of the Solar system's place in the cosmos.Peer reviewe

    Across-formant integration and speech intelligibility:effects of acoustic source properties in the presence and absence of a contralateral interferer

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    The role of source properties in across-formant integration was explored using three-formant (F1+F2+F3) analogues of natural sentences (targets). In experiment 1, F1+F3 were harmonic analogues (H1+H3) generated using a monotonous buzz source and second-order resonators; in experiment 2, F1+F3 were tonal analogues (T1+T3). F2 could take either form (H2 or T2). Target formants were always presented monaurally; the receiving ear was assigned randomly on each trial. In some conditions, only the target was present; in others, a competitor for F2 (F2C) was presented contralaterally. Buzz-excited or tonal competitors were created using the time-reversed frequency and amplitude contours of F2. Listeners must reject F2C to optimize keyword recognition. Whether or not a competitor was present, there was no effect of source mismatch between F1+F3 and F2. The impact of adding F2C was modest when it was tonal but large when it was harmonic, irrespective of whether F2C matched F1+F3. This pattern was maintained when harmonic and tonal counterparts were loudness-matched (experiment 3). Source type and competition, rather than acoustic similarity, governed the phonetic contribution of a formant. Contrary to earlier research using dichotic targets, requiring across-ear integration to optimize intelligibility, H2C was an equally effective informational masker for H2 as for T2

    Protector and friend: Turning points and discursive constructions of the stepparent role

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    Objective: To understand turning points (TPs) in the development of positive stepparent–stepchild communication and relationships. Background: Scholars stress the importance of communication in co-constructing healthy stepparent–stepchild relationships. The researchers focused on positive stepparenting via understanding transformational turning point (TP) events across time. Research questions explored how stepparents with an overall positive relationship with a stepchild characterize TPs and the discursive constructions of the stepparent role. Method: The team analyzed 877 pages of data from 37 in-depth interviews with stepparents who described self-identified TP events, reflected in visual graphs of 279 TPs. Results: Data were coded into 11 TP types, focused on structural and role changes for stepparents, co-constructed over time. The top three TP types were changes in household composition, communicating support through offering protection and being present/available, and role change, most frequently by functioning as a parent versus friend. All the TPs highlight discursive work to forge positive stepparenting roles. Conclusions: The findings extend earlier studies of stepchildren’s experiences and communication practices that ground resilience to manage relational resources through investments of quality time and enactment of social support. Implications: Applications suggest support for stepparents to have quality interactions with stepchildren and training to develop healthy communication practices and facilitate resilience

    Nuclear Retention of Multiply Spliced HIV-1 RNA in Resting CD4(+) T Cells

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    HIV-1 latency in resting CD4(+) T cells represents a major barrier to virus eradication in patients on highly active antiretroviral therapy (HAART). We describe here a novel post-transcriptional block in HIV-1 gene expression in resting CD4(+) T cells from patients on HAART. This block involves the aberrant localization of multiply spliced (MS) HIV-1 RNAs encoding the critical positive regulators Tat and Rev. Although these RNAs had no previously described export defect, we show that they exhibit strict nuclear localization in resting CD4(+) T cells from patients on HAART. Overexpression of the transcriptional activator Tat from non-HIV vectors allowed virus production in these cells. Thus, the nuclear retention of MS HIV-1 RNA interrupts a positive feedback loop and contributes to the non-productive nature of infection of resting CD4(+) T cells. To define the mechanism of nuclear retention, proteomic analysis was used to identify proteins that bind MS HIV-1 RNA. Polypyrimidine tract binding protein (PTB) was identified as an HIV-1 RNA-binding protein differentially expressed in resting and activated CD4(+) T cells. Overexpression of PTB in resting CD4(+) T cells from patients on HAART allowed cytoplasmic accumulation of HIV-1 RNAs. PTB overexpression also induced virus production by resting CD4(+) T cells. Virus culture experiments showed that overexpression of PTB in resting CD4(+) T cells from patients on HAART allowed release of replication-competent virus, while preserving a resting cellular phenotype. Whether through effects on RNA export or another mechanism, the ability of PTB to reverse latency without inducing cellular activation is a result with therapeutic implications

    Aminoglycosides for Intra-Abdominal Infection: Equal to the Challenge?

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    Background: Aminoglycosides, combined with antianaerobic agents, have been used widely for the treatment of intra-abdominal infection. However, some prospective randomized controlled trials and other data suggested that aminoglycosides were less efficacious than newer comparators for the treatment of these infections. We therefore performed a meta-analysis of all prospective randomized controlled trials utilizing aminoglycosides to reevaluate the efficacy of these agents for the treatment of intra-abdominal infection. Methods: Published English-language prospective randomized controlled trials comparing aminoglycosides with other agents for treatment of intra-abdominal infection were identified by MEDLINE search. For each study, data were collected regarding the number of patients enrolled and evaluated, their basic demographic characteristics, the sources of the intra-abdominal infections, the number of failures as determined by the study investigators, quality score, and the use of serum drug concentrations to monitor aminoglycoside therapy. These data were combined to calculate odds ratios for risk of therapeutic failure, which were assessed for significance using Chi-square analysis. Results: Forty-seven prospective randomized controlled trials comparing aminoglycosides to other agents were identified. These were published between 1981 and 2000, and included a total of 5,182 evaluable patients. Analysis of all studies combined revealed an odds ratio that slightly, but significantly, favored the comparators. After excluding six trials using comparators that lacked accepted antianaerobic efficacy, the odds ratio more strongly favored comparators. Trials published since 1990 also notably favored comparators. Analyzing results by quality score or the use of aminoglycoside monitoring did not alter these findings. Conclusions: In this meta-analysis, aminoglycosides were less efficacious than newer comparators for the treatment of intra-abdominal infection. Given the well-known toxicities of these agents, we conclude that they should not be used as first-line therapy for these infections

    Benchmarking image codecs by assessment of coded test images: the development of test images and new objective quality metrics, Journal of Telecommunications and Information Technology, 2006, nr 1

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    Objective quality measures are required for benchmarking codec performance. Our aim was to develop a simple, accurate method capable of rapidly measuring the degree of blockiness, edge-blur and ringing due to image compression. Two test images were designed to emphasise these artefacts. The efficacy of the new metrics is demonstrated using a JPEG codec at a range of compression levels
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