3,157 research outputs found
Measured Radiation and Background Levels During Transmission of Megawatt Electron Beams Through Millimeter Apertures
We report measurements of photon and neutron radiation levels observed while
transmitting a 0.43 MW electron beam through millimeter-sized apertures and
during beam-off, but accelerating gradient RF-on, operation. These measurements
were conducted at the Free-Electron Laser (FEL) facility of the Jefferson
National Accelerator Laboratory (JLab) using a 100 MeV electron beam from an
energy-recovery linear accelerator. The beam was directed successively through
6 mm, 4 mm, and 2 mm diameter apertures of length 127 mm in aluminum at a
maximum current of 4.3 mA (430 kW beam power). This study was conducted to
characterize radiation levels for experiments that need to operate in this
environment, such as the proposed DarkLight Experiment. We find that sustained
transmission of a 430 kW continuous-wave (CW) beam through a 2 mm aperture is
feasible with manageable beam-related backgrounds. We also find that during
beam-off, RF-on operation, multipactoring inside the niobium cavities of the
accelerator cryomodules is the primary source of ambient radiation when the
machine is tuned for 130 MeV operation.Comment: 9 pages, 11 figures, submitted to Nuclear Instruments and Methods in
Physics Research Section
A Guide for Using NIH Image J for Single Slice Cross-Sectional Area and Composition Analysis of the Thigh from Computed Tomography
Reports using computed tomography (CT) to estimate thigh skeletal muscle cross-sectional area and mean muscle attenuation are often difficult to evaluate due to inconsistent methods of quantification and/or poorly described analysis methods. This CT tutorial provides step-by-step instructions in using free, NIH Image J software to quantify both muscle size and composition in the mid-thigh, which was validated against a robust commercially available software, SliceOmatic. CT scans of the mid-thigh were analyzed from 101 healthy individuals aged 65 and older. Mean cross-sectional area and mean attenuation values are presented across seven defined Hounsfield unit (HU) ranges along with the percent contribution of each region to the total mid-thigh area. Inter-software correlation coefficients ranged from R2 = 0.92–0.99 for all specific area comparisons measured using the Image J method compared to SliceOmatic. We recommend reporting individual HU ranges for all areas measured. Although HU range 0–100 includes the majority of skeletal muscle area, HU range -29 to 150 appears to be the most inclusive for quantifying total thigh muscle. Reporting all HU ranges is necessary to determine the relative contribution of each, as they may be differentially affected by age, obesity, disease, and exercise. This standardized operating procedure will facilitate consistency among investigators reporting computed tomography characteristics of the thigh on single slice images.
Trial Registration: ClinicalTrials.gov NCT02308228
Risk Assessment and Comparative Effectiveness of Left Ventricular Assist Device and Medical Management in Ambulatory Heart Failure Patients The ROADMAP Study 2-Year Results
OBJECTIVES The authors sought to provide the pre-specified primary endpoint of the ROADMAP (Risk Assessment and Comparative Effectiveness of Left Ventricular Assist Device and Medical Management in Ambulatory Heart Failure Patients) trial at 2 years. BACKGROUND The ROADMAP trial was a prospective nonrandomized observational study of 200 patients (97 with a left ventricular assist device [LVAD], 103 on optimal medical management [OMM]) that showed that survival with improved functional status at 1 year was better with LVADs compared with OMM in a patient population of ambulatory New York Heart Association functional class IIIb/IV patients. METHODS The primary composite endpoint was survival on original therapy with improvement in 6-min walk distance \u3e= 75 m. RESULTS Patients receiving LVAD versus OMM had lower baseline health-related quality of life, reduced Seattle Heart Failure Model 1-year survival (78% vs. 84%; p = 0.012), and were predominantly INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) profile 4 (65% vs. 34%; p \u3c 0.001) versus profiles 5 to 7. More LVAD patients met the primary endpoint at 2 years: 30% LVAD versus 12% OMM (odds ratio: 3.2 [95% confidence interval: 1.3 to 7.7]; p = 0.012). Survival as treated on original therapy at 2 years was greater for LVAD versus OMM (70 +/- 5% vs. 41 +/- 5%; p \u3c 0.001), but there was no difference in intent-to-treat survival (70 +/- 5% vs. 63 +/- 5%; p = 0.307). In the OMM arm, 23 of 103 (22%) received delayed LVADs (18 within 12 months; 5 from 12 to 24 months). LVAD adverse events declined after year 1 for bleeding (primarily gastrointestinal) and arrhythmias. CONCLUSIONS Survival on original therapy with improvement in 6-min walk distance was superior with LVAD compared with OMM at 2 years. Reduction in key adverse events beyond 1 year was observed in the LVAD group. The ROADMAP trial provides risk-benefit information to guide patient- and physician-shared decision making for elective LVAD therapy as a treatment for heart failure. (Risk Assessment and Comparative Effectiveness of Left Ventricular Assist Device and Medical Management in Ambulatory Heart Failure Patients [ROADMAP]; NCT01452802
Managing and monitoring equality and diversity in UK sport: An evaluation of the sporting equals Racial Equality Standard and its impact on organizational change
Despite greater attention to racial equality in sport in recent years, the progress of national sports organizations toward creating equality of outcomes has been limited in the United Kingdom. The collaboration of the national sports agencies, equity organizations and national sports organizations (including national governing bodies of sport) has focused on Equality Standards. The authors revisit an earlier impact study of the Racial Equality Standard in sport and supplement it with another round of interview material to assess changing strategies to manage diversity in British sport. In particular, it tracks the impact on organizational commitment to diversity through the period of the establishment of the Racial Equality Standard and its replacement by an Equality Standard that deals with other diversity issues alongside race and ethnicity. As a result, the authors question whether the new, generic Equality Standard is capable of addressing racial diversity and promoting equality of outcomes. © 2006 Sage Publications
What’s so bad about scientism?
In their attempt to defend philosophy from accusations of uselessness made by prominent scientists, such as Stephen Hawking, some philosophers respond with the charge of ‘scientism.’ This charge makes endorsing a scientistic stance, a mistake by definition. For this reason, it begs the question against these critics of philosophy, or anyone who is inclined to endorse a scientistic stance, and turns the scientism debate into a verbal dispute. In this paper, I propose a different definition of scientism, and thus a new way of looking at the scientism debate. Those philosophers who seek to defend philosophy against accusations of uselessness would do philosophy a much better service, I submit, if they were to engage with the definition of scientism put forth in this paper, rather than simply make it analytic that scientism is a mistake
HIV-1/HSV-2 Co-Infected Adults in Early HIV-1 Infection Have Elevated CD4+ T Cell Counts
Introduction. HIV-1 is often acquired in the presence of pre-existing co-infections, such as Herpes Simplex Virus 2 (HSV-2). We examined the impact of HSV-2 status at the time of HIV-1 acquisition for its impact on subsequent clinical course, and total CD4+ T cell phenotypes. Methods. We assessed the relationship of HSV-1/HSV-2 co-infection status on CD4+ T cell counts and HIV-1 RNA levels over time prior in a cohort of 186 treatment naive adults identified during early HIV-1 infection. We assessed the activation and differentiation state of total CD4+ T cells at study entry by HSV-2 status. Results. of 186 recently HIV-1 infected persons, 101 (54%) were sero-positive for HSV-2. There was no difference in initial CD8+ T cell count, or differences between the groups for age, gender, or race based on HSV-2 status. Persons with HIV-1/HSV-2 co-infection sustained higher CD4+ T cell counts over time (+69 cells/ul greater (SD = 33.7, p = 0.04) than those with HIV-1 infection alone (Figure 1), after adjustment for HIV-1 RNA levels (-57 cells per 1 log(10) higher HIV-1 RNA, p<0.0001). We did not observe a relationship between HSV-2 infection status with plasma HIV-1 RNA levels over time. HSV-2 acquistion after HIV-1 acquisition had no impact on CD4+ count or viral load. We did not detect differences in CD4+ T cell activation or differentiation state by HSV-2+ status. Discussion. We observed no effect of HSV-2 status on viral load. However, we did observe that treatment naive, recently HIV-1 infected adults co-infected with HSV-2+ at the time of HIV-1 acquisition had higher CD4+ T cell counts over time. If verified in other cohorts, this result poses a striking paradox, and its public health implications are not immediately clear.Brazilian Program for STD and AIDS, Ministry of HealthSão Paulo City Health DepartmentFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)NIAID/NIHJohn E. Fogarty International CenterAIDS Research Institute of the AIDS Biology Program at UCSFCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Brazilian Ministry of EducationUniversidade Federal de São Paulo, Div Infect Dis, São Paulo, BrazilUniv Calif San Francisco, San Francisco Gen Hosp, Div HIV AIDS, San Francisco, CA USAUniv Calif San Francisco, Dept Expt Med, San Francisco, CA USASao Paula City Hlth Syst, São Paulo, BrazilUniversidade Federal de São Paulo, Div Infect Dis, São Paulo, BrazilBrazilian Program for STD and AIDS, Ministry of Health: 914/BRA/3014 UNESCO/KallasSão Paulo City Health Department: 2004-0.168.922-7/KallasFAPESP: 04/15856-9/KallasNIAID/NIH: AI066917/BarbourNIAID/NIH: AI064520/NixonJohn E. Fogarty International Center: D43 TW00003Web of Scienc
SDSSJ103913.70+533029.7: A Super Star Cluster in the Outskirts of a Galaxy Merger
We describe the serendipitous discovery in the spectroscopic data of the
Sloan Digital Sky Survey of a star-like object, SDSSJ103913.70+533029.7, at a
heliocentric radial velocity of +1012 km/s. Its proximity in position and
velocity to the spiral galaxy NGC 3310 suggests an association with the galaxy.
At this distance, SDSSJ103913.70+533029.7 has the luminosity of a super star
cluster and a projected distance of 17 kpc from NGC 3310. Its spectroscopic and
photometric properties imply a mass of > 10^6 solar masses and an age close to
that of the tidal shells seen around NGC 3310, suggesting that it formed in the
event which formed the shells.Comment: Accepted by AJ: 4 figures (1 color
Magnetized Four-Dimensional Orientifolds
We study deformations of (shift-)orientifolds in four
dimensions in the presence of both uniform Abelian internal magnetic fields and
quantized NS-NS backgrounds, that are shown to be equivalent to
asymmetric shift-orbifold projections. These models are related by -duality
to orientifolds with -branes intersecting at angles. As in corresponding
six-dimensional examples, -branes magnetized along two internal directions
acquire a charge with respect to the R-R six form, contributing to the tadpole
of the orthogonal -branes (``brane transmutation''). The resulting models
exhibit rank reduction of the gauge group and multiple matter families, due
both to the quantized and to the background magnetic fields. Moreover,
the low-energy spectra are chiral and anomaly free if additional -branes
longitudinal to the magnetized directions are present, and if there are no
Ramond-Ramond tadpoles in the corresponding twisted sectors of the undeformed
models.Comment: LaTeX file, 81 pages, 1 figure. 2 references adde
Pharmacokinetics and exposure response relationships of ustekinumab in patients with Crohn's Disease
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