1,509 research outputs found

    X-Rays from the Nearby Solitary Millisecond Pulsar PSR J0030+0451 - the Final ROSAT Observations

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    We report on X-ray observations of the solitary 4.8 ms pulsar PSR J0030+0451. The pulsar was one of the last targets observed in DEC-98 by the ROSAT PSPC. X-ray pulses are detected on a 4.5σ4.5\sigma level and make the source the 11th11^{th} millisecond pulsar detected in the X-ray domain. The pulsed fraction is found to be 69±1869\pm18%. The X-ray pulse profile is characterized by two narrow peaks which match the gross pulse profile observed at 1.4 GHz. Assuming a Crab-like spectrum the X-ray flux is in the range fx=23×1013f_x= 2-3\times 10^{-13} erg s1^{-1} cm2^{-2} (0.12.40.1-2.4 keV), implying an X-ray efficiency of Lx/E˙0.55×103(d/0.23kpc)2L_x/\dot{E}\sim 0.5-5 \times 10^{-3} (d/0.23 {kpc})^2.Comment: Accepted for publication in Ap

    Shared Governance at Virginia Commonwealth University: Increasing Awareness of Shared Governance Among Faculty

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    Abstract SHARED GOVERNANCE AT VIRGINIA COMMONWEALTH UNIVERSITY: INCREASING AWARENESS OF SHARED GOVERNANCE AMONG FACULTY By Andrea H. Becker, Carlton H. Goode, Jennifer C. Rivers, Melissa W. Tyler A capstone project submitted in partial fulfillment of the requirements for the degree of Doctor of Education in the Department of Educational Leadership at Virginia Commonwealth University Virginia Commonwealth University, 2022. Capstone Chair: Jonathan D. Becker, Ph.D., Department of Educational Leadership The primary focus of this study is to understand and define the concept of shared governance as practiced at Virginia Commonwealth University (VCU). The researchers approached the study through three guiding questions: What is shared governance as understood through relevant literature and practice; What are the current faculty perceptions of shared governance at VCU; How can awareness of shared governance be increased at the institution? A naturalistic study was conducted including a thorough literature review and narrative data collection from focus groups, individual interviews, and a modified charrette. Participants included faculty across the institution from a variety of ranks, units, and demographics. The study found faculty perceptions and literature speak to two overarching ways to experience shared governance at VCU: structure and culture. Structural components included the lack of standardized systems, workflow, and communication methods between university stakeholders. Cultural components encompassed decreased trust, engagement, and value of engaging in shared governance. Using the information collected, this paper offers recommendations for a collective definition of shared governance and strategies for increasing awareness. Keywords: shared governance, faculty governance, participatory governance, structure, communication, recognition, trust, transparenc

    New Pulsars from an Arecibo Drift Scan Search

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    We report the discovery of pulsars J0030+0451, J0711+0931, and J1313+0931 that were found in a search of 470 square degrees at 430 MHz using the 305m Arecibo telescope. The search has an estimated sensitivity for long period, low dispersion measure, low zenith angle, and high Galactic latitude pulsars of ~1 mJy, comparable to previous Arecibo searches. Spin and astrometric parameters for the three pulsars are presented along with polarimetry at 430 MHz. PSR J0030+0451, a nearby pulsar with a period of 4.8 ms, belongs to the less common category of isolated millisecond pulsars. We have measured significant polarization in PSR J0030+0451 over more than 50% of the period, and use these data for a detailed discussion of its magnetospheric geometry. Scintillation observations of PSR J0030+0451 provide an estimate of the plasma turbulence level along the line of sight through the local interstellar medium.Comment: 21 pages, 4 figures, Accepted for Publication in Ap

    Alpha-actinin-binding antibodies in relation to systemic lupus erythematosus and lupus nephritis

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    This study investigated the overall clinical impact of anti-α-actinin antibodies in patients with pre-selected autoimmune diseases and in a random group of anti-nuclear antibody (ANA)-positive individuals. The relation of anti-α-actinin antibodies with lupus nephritis and anti-double-stranded DNA (anti-dsDNA) antibodies represented a particular focus for the study. Using a cross-sectional design, the presence of antibodies to α-actinin was studied in selected groups, classified according to the relevant American College of Rheumatology classification criteria for systemic lupus erythematosus (SLE) (n = 99), rheumatoid arthritis (RA) (n = 68), Wegener's granulomatosis (WG) (n = 85), and fibromyalgia (FM) (n = 29), and in a random group of ANA-positive individuals (n = 142). Renal disease was defined as (increased) proteinuria with haematuria or presence of cellular casts. Sera from SLE, RA, and Sjøgren's syndrome (SS) patients had significantly higher levels of anti-α-actinin antibodies than the other patient groups. Using the geometric mean (± 2 standard deviations) in FM patients as the upper cutoff, 20% of SLE patients, 12% of RA patients, 4% of SS patients, and none of the WG patients were positive for anti-α-actinin antibodies. Within the SLE cohort, anti-α-actinin antibody levels were higher in patients with renal flares (p = 0.02) and correlated independently with anti-dsDNA antibody levels by enzyme-linked immunosorbent assay (p < 0.007) but not with other disease features. In the random ANA group, 14 individuals had anti-α-actinin antibodies. Of these, 36% had SLE, while 64% suffered from other, mostly autoimmune, disorders. Antibodies binding to α-actinin were detected in 20% of SLE patients but were not specific for SLE. They correlate with anti-dsDNA antibody levels, implying in vitro cross-reactivity of anti-dsDNA antibodies, which may explain the observed association with renal disease in SLE

    The Identification of the X-ray Counterpart to PSR J2021+4026

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    We report the probable identification of the X-ray counterpart to the gamma-ray pulsar PSR J2021+4026 using imaging with the Chandra X-ray Observatory ACIS and timing analysis with the Fermi satellite. Given the statistical and systematic errors, the positions determined by both satellites are coincident. The X-ray source position is R.A. 20h21m30.733s, Decl. +40 deg 26 min 46.04sec (J2000) with an estimated uncertainty of 1.3 arsec combined statistical and systematic error. Moreover, both the X-ray to gamma-ray and the X-ray to optical flux ratios are sensible assuming a neutron star origin for the X-ray flux. The X-ray source has no cataloged infrared-to-visible counterpart and, through new observations, we set upper limits to its optical emission of i' >23.0 mag and r' > 25.2mag. The source exhibits an X-ray spectrum with most likely both a powerlaw and a thermal component. We also report on the X-ray and visible light properties of the 43 other sources detected in our Chandra observation.Comment: Accepted for publication in the Astrophysical Journa

    Head-Toes-Knees-Shoulders task and EF in two samples of adolescents in Brazil and United States

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    Executive function (EF) is a foundational cognitive construct, which is linked to better cognitive and physical health throughout development. The present study examines the construct validity of an EF task, the Head-Toes-Knees-Shoulders task (HTKS) that was initially developed for young children, in a sample of adolescents. We investigate the initial validity and range in scores between 54 adolescents from Brazil (mean age 12.58) and 56 US adolescents (mean age 12.48) from different socioeconomic contexts. Results indicated that the HTKS showed sufficient variability in both samples, especially for a measure of HTKS efficiency (completion time divided by the total score). The US sample performed better on all cognitive measures. For the Brazilian sample, regression models controlling for age and sex showed a significant relationship between the digit span working memory task, the HTKS total score, and the HTKS efficiency score. The Heart and Flowers cognitive flexibility measure was also included as an independent variable only for the Brazil sample, showing a significant relationship with both HTKS scores. For the US sample, results showed that only the HTKS efficiency score was significantly related to the digit span working memory task. This study highlights the importance of cognitive efficiency measures to achieve greater validity, as they can assess a broader range of performance with different populations. The HTKS showed good ecological validity with two adolescent samples, as it differentiated between populations with high and low socioeconomic status from different cultural contexts

    Specific phobia predicts psychopathology in young women

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    Contains fulltext : 90255.pdf (publisher's version ) (Closed access)Although specific phobia is characterized by an early age at onset and by high rates of comorbidity, few studies have examined comorbid relationships prospectively. The present study investigated the association between specific phobia and the risk of a broad range of psychopathology among young women in the community. Data came from the Dresden Predictor Study in which 1,538 German women (18-25 years) completed a diagnostic interview at two time points. Women with specific phobia had a twofold increase in odds of developing any anxiety disorder, generalized anxiety disorder, depression, and any somatoform disorder during 17 months, compared to women without specific phobia. Except for depression, these associations persisted after adjustment for all comorbid mental disorders. Specific phobia thus appears to be a risk factor for a variety of problems. The result further underpins the necessity for early intervention for specific phobia to prevent later mental health problems

    The atypical kinase RIOK1 promotes tumor growth and invasive behavior

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    Despite being overexpressed in different tumor entities, RIO kinases are hardly characterized in mammalian cells. We investigated the role of these atypical kinases in different cancer cells. Using isogenic colon-, breast- and lung cancer cell lines, we demonstrate that knockdown of RIOK1, but not of RIOK2 or RIOK3, strongly impairs proliferation and invasiveness in conventional and 3D culture systems. Interestingly, these effects were mainly observed in RAS mutant cancer cells. In contrast, growth of RAS wildtype Caco-2 and Bcr-Abl-driven K562 cells is not affected by RIOK1 knockdown, suggesting a specific requirement for RIOK1 in the context of oncogenic RAS signaling. Furthermore, we show that RIOK1 activates NF-κB signaling and promotes cell cycle progression. Using proteomics, we identified the pro-invasive proteins Metadherin and Stathmin1 to be regulated by RIOK1. Additionally, we demonstrate that RIOK1 promotes lung colonization in vivo and that RIOK1 is overexpressed in different subtypes of human lung- and breast cancer. Altogether, our data suggest RIOK1 as a potential therapeutic target, especially in RAS-driven cancers

    HLA-DRB1*15:01-DQA1*01:02-DQB1*06:02 Haplotype Protects Autoantibody-Positive Relatives From Type 1 Diabetes Throughout the Stages of Disease Progression

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    The HLA-DRB1*15:01-DQA1*01:02-DQB1*06:02 haplotype is linked to protection from the development of type 1 diabetes (T1D). However, it is not known at which stages in the natural history of T1D development this haplotype affords protection. We examined a cohort of 3,358 autoantibody-positive relatives of T1D patients in the Pathway to Prevention (PTP) Study of the Type 1 Diabetes TrialNet. The PTP study examines risk factors for T1D and disease progression in relatives. HLA typing revealed that 155 relatives carried this protective haplotype. A comparison with 60 autoantibody-negative relatives suggested protection from autoantibody development. Moreover, the relatives with DRB1*15:01-DQA1*01:02-DQB1*06:02 less frequently expressed autoantibodies associated with higher T1D risk, were less likely to have multiple autoantibodies at baseline, and rarely converted from single to multiple autoantibody positivity on follow-up. These relatives also had lower frequencies of metabolic abnormalities at baseline and exhibited no overall metabolic worsening on follow-up. Ultimately, they had a very low 5-year cumulative incidence of T1D. In conclusion, the protective influence of DRB1*15:01-DQA1*01:02-DQB1*06:02 spans from autoantibody development through all stages of progression, and relatives with this allele only rarely develop T1D
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