497 research outputs found
К вопросу о контроле и автоматизации шахтных дегазационных систем
Розглянуті існуючі системи контролю та автоматизації шахтної газопровідної мережі, а
також засобі контролю газодинамічних параметрів метано-повітряної суміші у дільничному
дегазаційному трубопроводі.The existing system of control and automation of mine degassingnetwork, and controls the gasdynamic parameters of methane-air mixture in the precinct line degassing
Fast X-ray Transients and Their Connection to Gamma-Ray Bursts
Fast X-ray transients (FXTs) with timescales from seconds to hours have been
seen by numerous space instruments. We have assembled archival data from
Ariel-5, HEAO-1 (A-1 and A-2), WATCH, ROSAT, and Einstein to produce a global
fluence-frequency relationship for these events. Fitting the log N-log S
distribution over several orders of magnitude to simple power law we find a
slope of -1.0. The sources of FXTs are undoubtedly heterogeneous, the -1 power
law is an approximate result of the summation of these multiple sources. Two
major contributions come from gamma-ray bursts and stellar flares.
Extrapolating from the BATSE catalog of GRBs, we find that the fraction of
X-ray flashes that can be the X-ray counterparts of gamma-ray bursts is a
function of fluence. Certainly most FXTs are not counterparts of standard
gamma-ray bursts. The fraction of FXTs from non-GRB sources, such as magnetic
stars, is greatest for the faintest FXTs. Our understanding of the FXT
phenomenon remains limited and would greatly benefit from a large, homogeneous
data set, which requires a wide-field, sensitive instrument.Comment: 36 pages, 8 figure
the State of Utah v. Walter Preston Boggess, Jr. : Brief of Respondent
An Appeal from a Judgment of the District Court of the Fourth Judicial District, The Honorable J, Robert Bullock, District Court Judg
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Health-related quality of life in Huntington’s Disease patients: a comparison of proxy assessment and patient self-rating using the disease-specific Huntington’s Disease health-related quality of life questionnaire (HDQoL)
Huntington’s disease (HD) is a fatal, neurodegenerative disease for which there is no known cure. Proxy evaluation is relevant for HD as its manifestation might limit the ability of persons to report their health-related quality of life (HrQoL). This study explored patient–proxy ratings of HrQoL of persons at different stages of HD, and examined factors that may affect proxy ratings. A total of 105 patient–proxy pairs completed the Huntington’s disease health-related quality of life questionnaire (HDQoL) and other established HrQoL measures (EQ-5D and SF-12v2). Proxy–patient agreement was assessed in terms of absolute level (mean ratings) and intraclass correlation. Proxies’ ratings were at a similar level to patients’ self-ratings on an overall Summary Score and on most of the six Specific Scales of the HDQoL. On the Specific Hopes and Worries Scale, proxies on average rated HrQoL as better than patients’ self-ratings, while on both the Specific Cognitive Scale and Specific Physical and Functional Scale proxies tended to rate HrQoL more poorly than patients themselves. The patient’s disease stage and mental wellbeing (SF-12 Mental Component scale) were the two factors that primarily affected proxy assessment. Proxy scores were strongly correlated with patients’ self-ratings of HrQoL, on the Summary Scale and all Specific Scales. The patient–proxy correlation was lower for patients at moderate stages of HD compared to patients at early and advanced stages. The proxy report version of the HDQoL is a useful complementary tool to self-assessment, and a promising alternative when individual patients with advanced HD are unable to self-report
Risk factors of unmet needs among women with breast cancer in the post-treatment phase
OBJECTIVE: Unmet health care needs require additional care resources to achieve optimal patient well-being. In this nationwide study we examined associations between a number of risk factors and unmet needs after treatment among women with breast cancer, while taking into account their health care practices. We expected that more care use would be associated with lower levels of unmet needs. METHODS: A multicenter, prospective, observational design was employed. Women with primary breast cancer completed questionnaires 6 and 15 months post-diagnosis. Medical data were retrieved from medical records. Direct and indirect associations between sociodemographic and clinical risk factors, distress, care use, and unmet needs were investigated with structural equation modeling. RESULTS: Seven hundred forty-six participants completed both questionnaires (response rate 73.7%). The care services received were not negatively associated with the reported levels of unmet needs after treatment. Comorbidity was associated with higher physical and daily living needs. Higher age was associated with higher health system-related and informational needs. Having had chemotherapy and a mastectomy were associated with higher sexuality needs and breast cancer-specific issues, respectively. A higher level of distress was associated with higher levels of unmet need in all domains. CONCLUSIONS: Clinicians may use these results to timely identify which women are at risk of developing specific unmet needs after treatment. Evidence-based, cost-effective (online) interventions that target distress, the most influential risk factor, should be further implemented and disseminated among patients and clinicians
Long Type I X-ray Bursts and Neutron Star Interior Physics
Superbursts are very energetic Type I X-ray bursts discovered in recent years
by long term monitoring of X-ray bursters, believed to be due to unstable
ignition of carbon in the deep ocean of the neutron star. A number of
"intermediate duration" bursts have also been observed, probably associated
with ignition of a thick helium layer. We investigate the sensitivity of these
long X-ray bursts to the thermal profile of the neutron star crust and core. We
first compare cooling models of superburst lightcurves with observations, and
derive constraints on the ignition mass and energy release, and then calculate
ignition models for superbursts and pure helium bursts, and compare to
observations. The superburst lightcurves and ignition models imply that the
carbon mass fraction is approximately 20% or greater in the fuel layer,
constraining models of carbon production. However, the most important result is
that when Cooper pairing neutrino emission is included in the crust, the
temperature is too low to support unstable carbon ignition at the observed
column depths. Some additional heating mechanism is required in the
accumulating fuel layer to explain the observed properties of superbursts. If
Cooper pair emission is less efficient than currently thought, the observed
ignition depths for superbursts imply that the crust is a poor conductor, and
the core neutrino emission is not more efficient than modified URCA. The
observed properties of helium bursts support these conclusions, requiring
inefficient crust conductivity and core neutrino emission.Comment: submitted to ApJ (22 pages, 26 figures
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