2,513 research outputs found
До питання конституційної правосуб’єктності українського народу
Розглядаються поняття сутності, характеру і змісту конституційної правосуб’єктності українського народу.Рассматриваются понятия сущности, характера и содержания конституционной
правосубъектности украинского народа.The article deals with the notion, subject matter, character and content of constitutional legal standing of Ukrainian people
Proximity to Sports Facilities and Sports Participation for Adolescents in Germany
Objectives - To assess the relationship between proximity to specific sports facilities and participation in the corresponding sports activities for adolescents in Germany.
Methods - A sample of 1,768 adolescents aged 11–17 years old and living in 161 German communities was examined. Distances to the nearest sports facilities were calculated as an indicator of proximity to sports facilities using Geographic Information Systems (GIS). Participation in specific leisure-time sports activities in sports clubs was assessed using a self-report questionnaire and individual-level socio-demographic variables were derived from a parent questionnaire. Community-level socio-demographics as covariates were selected from the INKAR database, in particular from indicators and maps on land development. Logistic regression analyses were conducted to examine associations between proximity to the nearest sports facilities and participation in the corresponding sports activities.
Results - The logisitic regression analyses showed that girls residing longer distances from the nearest gym were less likely to engage in indoor sports activities; a significant interaction between distances to gyms and level of urbanization was identified. Decomposition of the interaction term showed that for adolescent girls living in rural areas participation in indoor sports activities was positively associated with gym proximity. Proximity to tennis courts and indoor pools was not associated with participation in tennis or water sports, respectively.
Conclusions - Improved proximity to gyms is likely to be more important for female adolescents living in rural areas
Factors influencing consent rates of deceased organ donation in Western Cape Province, South Africa
Background. South Africa (SA) has very low and unchanging organ donation rates. A key point in the pathway of organ donation is obtaining informed consent from the family, which is necessary before organ donation can proceed. There is no published SA research on the consent rate and factors that influence this.Objectives. To describe the number of requests for consent and factors influencing this process in the SA context.Methods. A prospective descriptive study was performed of all requests to families for organ donation in Western Cape Province, SA, by Groote Schuur Hospital (state sector), Red Cross War Memorial Children’s Hospital (state sector) and Netcare (private sector) transplant co-ordinators from 1 May 2017 to 1 May 2018 to describe factors influencing consent rates.Results. The 6 co-ordinators (3 state sector and 3 private sector) recorded data of 83 consecutive families approached in 16 hospitals over the 1-year period. Consent to organ donation was granted for 23 family requests (n=18 (state sector); n=5 (private sector)). The number of families approached was greater in the state sector (n=74) than in the private sector (n=9). The overall consent rate was 27.7% (24.3% (state sector); 55.5% (private sector)). The majority of referrals came from trauma and emergency units (n=55; 66.3%) and very few from intensive care units (n=25; 30.1%). Immediate fluid resuscitation was required in 56 (67.5%) potential donors. The majority of families (n=74; 89.2%) were receptive to the organ donation request, independent of their ultimate decision regarding donation. The main reason given for refusing to consent was that it was against their religion (n=21) or culture (n=18).Conclusions. This study showed that the number of families approached for consent to organ donation were low in the Western Cape (lower in the private sector), with a low consent rate (lower in the state sector). Donor management by clinical teams needs to be ongoing and active during the consent process. Consent discussions (and public awareness initiatives) need to be sensitive to and deal with religious and cultural reservations about organ donation
Observation of Sommerfeld precursors on a fluid surface
We report the observation of two types of Sommerfeld precursors (or
forerunners) on the surface of a layer of mercury. When the fluid depth
increases, we observe a transition between these two precursor surface waves in
good agreement with the predictions of asymptotic analysis. At depths thin
enough compared to the capillary length, high frequency precursors propagate
ahead of the ''main signal'' and their period and amplitude, measured at a
fixed point, increase in time. For larger depths, low frequency ''precursors''
follow the main signal with decreasing period and amplitude. These behaviors
are understood in the framework of the analysis first introduced for linear
transient electromagnetic waves in a dielectric medium by Sommerfeld and
Brillouin [1].Comment: to be published in Physical Review Letter
The stem/progenitor landscape is reshaped in a mouse model of essential thrombocythemia and causes excess megakaryocyte production
Frameshift mutations in CALR (calreticulin) are associated with essential thrombocythemia (ET), but the stages at and mechanisms by which mutant CALR drives transformation remain incompletely defined. Here, we use single-cell approaches to examine the hematopoietic stem/progenitor cell landscape in a mouse model of mutant CALR-driven ET. We identify a trajectory linking hematopoietic stem cells (HSCs) with megakaryocytes and prospectively identify a previously unknown intermediate population that is overrepresented in the disease state. We also show that mutant CALR drives transformation primarily from the earliest stem cell compartment, with some contribution from megakaryocyte progenitors. Last, relative to wild-type HSCs, mutant CALR HSCs show increases in JAK-STAT signaling, the unfolded protein response, cell cycle, and a previously undescribed up-regulation of cholesterol biosynthesis. Overall, we have identified a novel megakaryocyte-biased cell population that is increased in a mouse model of ET and described transcriptomic changes linking CALR mutations to increased HSC proliferation and megakaryopoiesis
Revenue Optimization for the Ocean Grazer Wave Energy Converter through Storage Utilization
Increased penetration of renewable energy generation motivates a change of paradigm in the way power systems are structured and operated, as advocated by the smart grid concept. Accordingly, in this paper we investigate the lossless storage capabilities of the Ocean Grazer wave energy converter (WEC), which could facilitate the aforementioned paradigm shift. This specific WEC exhibits both adaptability with respect to the incoming waves and significant lossless storage capabilities. We propose a model predictive control (MPC) strategy based on a lumped dynamical model in order to mitigate power imbalances in the power grid and maximize the revenue of the WEC. Furthermore, we illustrate that the proposed strategy exploits the WEC energy storage capabilities and we show the economic benefits it brings. Lastly, the proposed strategy is compared with a heuristic approach and a setting without storage
Three ways to solve the orbit of KIC11558725: a 10 day beaming sdB+WD binary with a pulsating subdwarf
The recently discovered subdwarf B (sdB) pulsator KIC11558725 features a rich
g-mode frequency spectrum, with a few low-amplitude p-modes at short periods,
and is a promising target for a seismic study aiming to constrain the internal
structure of this star, and of sdB stars in general.
We have obtained ground-based spectroscopic Balmer-line radial-velocity
measurements of KIC11558725, spanning the 2010 and 2011 observing seasons. From
these data we have discovered that KIC11558725 is a binary with period P=10.05
d, and that the radial-velocity amplitude of the sdB star is 58 km/s.
Consequently the companion of the sdB star has a minimum mass of 0.63 M\odot,
and is therefore most likely an unseen white dwarf.
We analyse the near-continuous 2010-2011 Kepler light curve to reveal orbital
Doppler-beaming light variations at the 238 ppm level, which is consistent with
the observed spectroscopic orbital radial-velocity amplitude of the subdwarf.
We use the strongest 70 pulsation frequencies in the Kepler light curve of the
subdwarf as clocks to derive a third consistent measurement of the orbital
radial-velocity amplitude, from the orbital light-travel delay.
We use our high signal-to-noise average spectra to study the atmospheric
parameters of the sdB star, deriving Teff = 27 910K and log g = 5.41 dex, and
find that carbon, nitrogen and oxygen are underabundant relative to the solar
mixture.
Furthermore, we extract more than 160 significant frequencies from the Kepler
light curve. We investigate the pulsation frequencies for expected period
spacings and rotational splittings. We find period-spacing sequences of
spherical-harmonic degrees \ell=1 and \ell=2, and we associate a large fraction
of the g-modes in KIC11558725 with these sequences. From frequency splittings
we conclude that the subdwarf is rotating subsynchronously with respect to the
orbit
Mass ratio from Doppler beaming and R{\o}mer delay versus ellipsoidal modulation in the Kepler data of KOI-74
We present a light curve analysis and radial velocity study of KOI-74, an
eclipsing A star + white dwarf binary with a 5.2 day orbit. Aside from new
spectroscopy covering the orbit of the system, we used 212 days of publicly
available Kepler observations and present the first complete light curve
fitting to these data, modelling the eclipses and transits, ellipsoidal
modulation, reflection, and Doppler beaming. Markov Chain Monte Carlo
simulations are used to determine the system parameters and uncertainty
estimates. Our results are in agreement with earlier studies, except that we
find an inclination of 87.0 \pm 0.4\degree, which is significantly lower than
the previously published value. We find that the mass ratio derived from the
radial velocity amplitude (q=0.104 \pm 0.004) disagrees with that derived from
the ellipsoidal modulation (q=0.052 \pm 0.004} assuming corotation). This was
found before, but with our smaller inclination, the discrepancy is even larger
than previously reported. Accounting for the rapid rotation of the A-star is
found to increase the discrepancy even further by lowering the mass ratio to
q=0.047 \pm 0.004. These results indicate that one has to be extremely careful
in using the amplitude of an ellipsoidal modulation signal in a close binary to
determine the mass ratio, when a proof of corotation is not firmly established.
The radial velocities that can be inferred from the detected Doppler beaming in
the light curve are found to be in agreement with our spectroscopic radial
velocity determination. We also report the first measurement of R{\o}mer delay
in a light curve of a compact binary. This delay amounts to -56 \pm 17 s and is
consistent with the mass ratio derived from the radial velocity amplitude. The
firm establishment of this mass ratio at q=0.104 \pm 0.004 leaves little doubt
that the companion of KOI-74 is a low mass white dwarf.Comment: 9 pages, 7 figures, 2 tables; accepted for publication in MNRA
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