2,044 research outputs found

    Self-Evaluation of Black and White College Students

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    A major issue in the social psychology of race relations has been the axiom that blacks tend to manifest lower self-esteem than whites.[1] Much of the empirical support for this hypothesis came from studies demonstrating that blacks are stigmatized and subjected to a variety of unpleasant and derogatory experiences.[2] However, these studies are limited in two respects: first, by their use of small, nonrepresentative samples (primarily nursery school and kindergarten children) and second, by their reliance upon inferential (semi-projective) measures of self-esteem.[3

    Metropolitan Centers: Evaluating Local Implementation of Regional Plans and Policies

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    The Denver and Salt Lake City Metropolitan Planning Organizations (MPOs) have embarked upon regional visioning strategies that promote development around higher density, mixed use centers with current or future access to transit. This study examines the programs and policies in the Salt Lake City and Denver regions to examine regional vision influence on local planning and the opportunities and constraints facing centers. The research team analyzed local plans over the past several decades, interviewed planners, and examined demographic, land use and transportation characteristics in select centers across the region. We found that the regional vision had a moderate influence on local planning, due to vague definitions and criteria. However, light rail investment and market forces have had a more substantial influence—resulting in cities developing supportive transit oriented development policies. While over 100 centers have been designated, many face significant challenges to support regional goals, particularly because many light rail lines were located along rail and freeway alignments. A limited number of “tipping point centers” already contain the necessary elements to be successful with city and private investment. Many “greenfield centers” offer significant future opportunity for development, but their suburban location and infrastructure needs present significant costs and challenges. Many other “redevelopment centers” are dominated by industrial, commercial or office development, and the land use and transportation patterns within these centers present substantial hurdles that may limit their potential to achieve regional goals

    New Horizons: Long-Range Kuiper Belt Targets Observed by the Hubble Space Telescope

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    We report on Hubble Space Telescope (HST) observations of three Kuiper Belt Objects (KBOs), discovered in our dedicated ground-based search campaign, that are candidates for long-range observations from the New Horizons spacecraft: 2011 JY31, 2011 HZ102, and 2013 LU35. Astrometry with HST enables both current and future critical accuracy improvements for orbit precision, required for possible New Horizons observations, beyond what can be obtained from the ground. Photometric colors of all three objects are red, typical of the Cold Classical dynamical population within which they reside; they are also the faintest KBOs to have had their colors measured. None are observed to be binary with HST above separations of ~0.02 arcsec (~700 km at 44 AU) and {\Delta}m less than or equal to 0.5.Comment: Pages: 11, Figures: 2, Tables: 3, Icarus, available online May 2014 (http://dx.doi.org/10.1016/j.icarus.2014.04.014

    Automated speckle tracking algorithm to aid on-axis imaging in echocardiography

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    Obtaining a “correct” view in echocardiography is a subjective process in which an operator attempts to obtain images conforming to consensus standard views. Real-time objective quantification of image alignment may assist less experienced operators, but no reliable index yet exists. We present a fully automated algorithm for detecting incorrect medial/lateral translation of an ultrasound probe by image analysis. The ability of the algorithm to distinguish optimal from sub-optimal four-chamber images was compared to that of specialists—the current “gold-standard.” The orientation assessments produced by the automated algorithm correlated well with consensus visual assessments of the specialists (r=0.87r=0.87) and compared favourably with the correlation between individual specialists and the consensus, 0.82±0.09. Each individual specialist’s assessments were within the consensus of other specialists, 75±14% of the time, and the algorithm’s assessments were within the consensus of specialists 85% of the time. The mean discrepancy in probe translation values between individual specialists and their consensus was 0.97±0.87  cm, and between the automated algorithm and specialists’ consensus was 0.92±0.70  cm. This technology could be incorporated into hardware to provide real-time guidance for image optimisation—a potentially valuable tool both for training and quality control

    Comparison of different approaches to manage multi-site magnetic resonance spectroscopy clinical data analysis

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    IntroductionThe effects caused by differences in data acquisition can be substantial and may impact data interpretation in multi-site/scanner studies using magnetic resonance spectroscopy (MRS). Given the increasing use of multi-site studies, a better understanding of how to account for different scanners is needed. Using data from a concussion population, we compare ComBat harmonization with different statistical methods in controlling for site, vendor, and scanner as covariates to determine how to best control for multi-site data.MethodsThe data for the current study included 545 MRS datasets to measure tNAA, tCr, tCho, Glx, and mI to study the pediatric concussion acquired across five sites, six scanners, and two different MRI vendors. For each metabolite, the site and vendor were accounted for in seven different models of general linear models (GLM) or mixed-effects models while testing for group differences between the concussion and orthopedic injury. Models 1 and 2 controlled for vendor and site. Models 3 and 4 controlled for scanner. Models 5 and 6 controlled for site applied to data harmonized by vendor using ComBat. Model 7 controlled for scanner applied to data harmonized by scanner using ComBat. All the models controlled for age and sex as covariates.ResultsModels 1 and 2, controlling for site and vendor, showed no significant group effect in any metabolites, but the vendor and site were significant factors in the GLM. Model 3, which included a scanner, showed a significant group effect for tNAA and tCho, and the scanner was a significant factor. Model 4, controlling for the scanner, did not show a group effect in the mixed model. The data harmonized by the vendor using ComBat (Models 5 and 6) had no significant group effect in both the GLM and mixed models. Lastly, the data harmonized by the scanner using ComBat (Model 7) showed no significant group effect. The individual site data suggest there were no group differences.ConclusionUsing data from a large clinical concussion population, different analysis techniques to control for site, vendor, and scanner in MRS data yielded different results. The findings support the use of ComBat harmonization for clinical MRS data, as it removes the site and vendor effects

    microRNA expression in the prefrontal cortex of individuals with schizophrenia and schizoaffective disorder

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    BACKGROUND: microRNAs (miRNAs) are small, noncoding RNA molecules that are now thought to regulate the expression of many mRNAs. They have been implicated in the etiology of a variety of complex diseases, including Tourette's syndrome, Fragile × syndrome, and several types of cancer. RESULTS: We hypothesized that schizophrenia might be associated with altered miRNA profiles. To investigate this possibility we compared the expression of 264 human miRNAs from postmortem prefrontal cortex tissue of individuals with schizophrenia (n = 13) or schizoaffective disorder (n = 2) to tissue of 21 psychiatrically unaffected individuals using a custom miRNA microarray. Allowing a 5% false discovery rate, we found that 16 miRNAs were differentially expressed in prefrontal cortex of patient subjects, with 15 expressed at lower levels (fold change 0.63 to 0.89) and 1 at a higher level (fold change 1.77) than in the psychiatrically unaffected comparison subjects. The expression levels of 12 selected miRNAs were also determined by quantitative RT-PCR in our lab. For the eight miRNAs distinguished by being expressed at lower microarray levels in schizophrenia samples versus comparison samples, seven were also expressed at lower levels with quantitative RT-PCR. CONCLUSION: This study is the first to find altered miRNA profiles in postmortem prefrontal cortex from schizophrenia patients

    Quantifying and valuing carbon flows and stores in coastal and shelf ecosystems in the UK

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    Evidence shows that habitats with potential to mitigate against greenhouse gases emissions, by taking up and storing CO2, are being lost due to the effects of on-going human activities and climate change. The carbon storage by terrestrial habitats (e.g. tropical forests) and the role of coastal habitats (‘Blue Carbon’) as carbon storage sinks is well recognised. Offshore shelf sediments are also a manageable carbon store, covering ∌9% of global marine area, but not currently protected by international agreements to enable their conservation. Through a scenario analysis, we explore the economic value of the damage of human activities and climate change can inflict on UK marine habitats, including shelf sea sediments. In a scenario of increased human and climate pressures over a 25-year period, we estimate damage costs up to US$12.5 billion from carbon release linked to disturbance of coastal and shelf sea sediment carbon stores. It may be possible to manage socio-economic pressure to maintain sedimentary carbon storage, but the trade-offs with other global social welfare benefits such as food security will have to be taken into account. To develop effective incentive mechanisms to preserve these valuable coastal and marine ecosystems within a sustainability governance framework, robust evidence is required

    The inpatient burden of abdominal and gynecological adhesiolysis in the US

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    <p>Abstract</p> <p>Background</p> <p>Adhesions are fibrous bands of scar tissue, often a result of surgery, that form between internal organs and tissues, joining them together abnormally. Postoperative adhesions frequently occur following abdominal surgery, and are associated with a large economic burden. This study examines the inpatient burden of adhesiolysis in the United States (i.e., number and rate of events, cost, length of stay [LOS]).</p> <p>Methods</p> <p>Hospital discharge data for patients with primary and secondary adhesiolysis were analyzed using the 2005 Healthcare Cost and Utilization Project's Nationwide Inpatient Sample. Procedures were aggregated by body system.</p> <p>Results</p> <p>We identified 351,777 adhesiolysis-related hospitalizations: 23.2% for primary and 76.8% for secondary adhesiolysis. The average LOS was 7.8 days for primary adhesiolysis. We found that 967,332 days of care were attributed to adhesiolysis-related procedures, with inpatient expenditures totaling 2.3billion(2.3 billion (1.4 billion for primary adhesiolysis; 926millionforsecondaryadhesiolysis).Hospitalizationsforadhesiolysisincreasedsteadilybyageandwerehigherforwomen.Ofsecondaryadhesiolysisprocedures,46.3926 million for secondary adhesiolysis). Hospitalizations for adhesiolysis increased steadily by age and were higher for women. Of secondary adhesiolysis procedures, 46.3% involved the female reproductive tract, resulting in 57,005 additional days of care and 220 million in attributable costs.</p> <p>Conclusions</p> <p>Adhesiolysis remain an important surgical problem in the United States. Hospitalization for this condition leads to high direct surgical costs, which should be of interest to providers and payers.</p

    Systematic Bias in Genomic Classification Due to Contaminating Non-neoplastic Tissue in Breast Tumor Samples

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    Abstract Background Genomic tests are available to predict breast cancer recurrence and to guide clinical decision making. These predictors provide recurrence risk scores along with a measure of uncertainty, usually a confidence interval. The confidence interval conveys random error and not systematic bias. Standard tumor sampling methods make this problematic, as it is common to have a substantial proportion (typically 30-50%) of a tumor sample comprised of histologically benign tissue. This "normal" tissue could represent a source of non-random error or systematic bias in genomic classification. Methods To assess the performance characteristics of genomic classification to systematic error from normal contamination, we collected 55 tumor samples and paired tumor-adjacent normal tissue. Using genomic signatures from the tumor and paired normal, we evaluated how increasing normal contamination altered recurrence risk scores for various genomic predictors. Results Simulations of normal tissue contamination caused misclassification of tumors in all predictors evaluated, but different breast cancer predictors showed different types of vulnerability to normal tissue bias. While two predictors had unpredictable direction of bias (either higher or lower risk of relapse resulted from normal contamination), one signature showed predictable direction of normal tissue effects. Due to this predictable direction of effect, this signature (the PAM50) was adjusted for normal tissue contamination and these corrections improved sensitivity and negative predictive value. For all three assays quality control standards and/or appropriate bias adjustment strategies can be used to improve assay reliability. Conclusions Normal tissue sampled concurrently with tumor is an important source of bias in breast genomic predictors. All genomic predictors show some sensitivity to normal tissue contamination and ideal strategies for mitigating this bias vary depending upon the particular genes and computational methods used in the predictor

    AMI observations of Lynds Dark Nebulae: further evidence for anomalous cm-wave emission

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    Observations at 14.2 to 17.9 GHz made with the AMI Small Array towards fourteen Lynds Dark Nebulae with a resolution of 2' are reported. These sources are selected from the SCUBA observations of Visser et al. (2001) as small angular diameter clouds well matched to the synthesized beam of the AMI Small Array. Comparison of the AMI observations with radio observations at lower frequencies with matched uv-plane coverage is made, in order to search for any anomalous excess emission which can be attributed to spinning dust. Possible emission from spinning dust is identified as a source within a 2' radius of the Scuba position of the Lynds dark nebula, exhibiting an excess with respect to lower frequency radio emission. We find five sources which show a possible spinning dust component in their spectra. These sources have rising spectral indices in the frequency range 14.2--17.9 GHz. Of these five one has already been reported, L1111, we report one new definite detection, L675, and three new probable detections (L944, L1103 and L1246). The relative certainty of these detections is assessed on the basis of three criteria: the extent of the emission, the coincidence of the emission with the Scuba position and the likelihood of alternative explanations for the excess. Extended microwave emission makes the likelihood of the anomalous emission arising as a consequence of a radio counterpart to a protostar or a proto-planetary disk unlikely. We use a 2' radius in order to be consistent with the IRAS identifications of dark nebulae (Parker 1988), and our third criterion is used in the case of L1103 where a high flux density at 850 microns relative to the FIR data suggests a more complicated emission spectrum.Comment: submitted MNRA
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