917 research outputs found
Environment and Rural Affairs Monitoring & Modelling Programme - ERAMMP Technical Annex 1: Soil nutrient management for improved land. Sustainable Farming Scheme. Evidence Review.
The Brief: Establish intervention logic for Soil Nutrient Management (SNM) plans across all improved agricultural land. Establish the environmental benefits including GHG emissions reduction, biodiversity, water quality and air quality which will be secured through the universal uptake of SNM plans. Identify the contribution that better SNM will make to the economic resilience and sustainability of Welsh agriculture
Displaying the Heterogeneity of the SN 2002cx-like Subclass of Type Ia Supernovae with Observations of the Pan-STARRS-1 Discovered SN2009ku
SN2009ku, discovered by Pan-STARRS-1, is a Type Ia supernova (SNIa), and a
member of the distinct SN2002cx-like class of SNeIa. Its light curves are
similar to the prototypical SN2002cx, but are slightly broader and have a later
rise to maximum in g. SN2009ku is brighter (~0.6 mag) than other SN2002cx-like
objects, peaking at M_V = -18.4 mag - which is still significantly fainter than
typical SNeIa. SN2009ku, which had an ejecta velocity of ~2000 kms^-1 at 18
days after maximum brightness is spectroscopically most similar to SN2008ha,
which also had extremely low-velocity ejecta. However, SN2008ha had an
exceedingly low luminosity, peaking at M_V = -14.2 mag, ~4 mag fainter than
SN2009ku. The contrast of high luminosity and low ejecta velocity for SN2009ku
is contrary to an emerging trend seen for the SN2002cx class. SN2009ku is a
counter-example of a previously held belief that the class was more homogeneous
than typical SNeIa, indicating that the class has a diverse progenitor
population and/or complicated explosion physics. As the first example of a
member of this class of objects from the new generation of transient surveys,
SN2009ku is an indication of the potential for these surveys to find rare and
interesting objects.Comment: 7 pages, 3 figure
Isothermal Plasma Wave Properties of the Schwarzschild de-Sitter Black Hole in a Veselago Medium
In this paper, we study wave properties of isothermal plasma for the
Schwarzschild de-Sitter black hole in a Veselago medium. We use ADM 3+1
formalism to formulate general relativistic magnetohydrodynamical (GRMHD)
equations for the Schwarzschild de-Sitter spacetime in Rindler coordinates.
Further, Fourier analysis of the linearly perturbed GRMHD equations for the
rotating (non-magnetized and magnetized) background is taken whose determinant
leads to a dispersion relation. We investigate wave properties by using
graphical representation of the wave vector, the refractive index, change in
refractive index, phase and group velocities. Also, the modes of wave
dispersion are explored. The results indicate the existence of the Veselago
medium.Comment: 24 pages, 12 figures, accepted for publication in Astrophys. Space
Sci. arXiv admin note: text overlap with arXiv:1101.0884 and arxiv:1007.285
Frictional drag between non-equilibrium charged gases
The frictional drag force between separated but coupled two-dimensional
electron gases of different temperatures is studied using the non-equilibrium
Green function method based on the separation of center-of-mass and relative
dynamics of electrons. As the mechanisms of producing the frictional force we
include the direct Coulomb interaction, the interaction mediated via virtual
and real TA and LA phonons, optic phonons, plasmons, and TA and LA
phonon-electron collective modes. We found that, when the distance between the
two electron gases is large, and at intermediate temperature where plasmons and
collective modes play the most important role in the frictional drag, the
possibility of having a temperature difference between two subsystems modifies
greatly the transresistivity.Comment: 8figure
Transverse Wave Propagation in Relativistic Two-fluid Plasmas in de Sitter Space
We investigate transverse electromagnetic waves propagating in a plasma in
the de Sitter space. Using the 3+1 formalism we derive the relativistic
two-fluid equations to take account of the effects due to the horizon and
describe the set of simultaneous linear equations for the perturbations. We use
a local approximation to investigate the one-dimensional radial propagation of
Alfv\'en and high frequency electromagnetic waves and solve the dispersion
relation for these waves numerically.Comment: 19 pages, 12 figure
QCD Corrections to QED Vacuum Polarization
We compute QCD corrections to QED calculations for vacuum polarization in
background magnetic fields. Formally, the diagram for virtual loops
is identical to the one for virtual loops. However due to
confinement, or to the growth of as decreases, a direct
calculation of the diagram is not allowed. At large we consider the
virtual diagram, in the intermediate region we discuss the role of
the contribution of quark condensates \left and at the
low-energy limit we consider the , as well as charged pion
loops. Although these effects seem to be out of the measurement accuracy of
photon-photon laboratory experiments they may be relevant for -ray
burst propagation. In particular, for emissions from the center of the galaxy
(8.5 kpc), we show that the mixing between the neutral pseudo-scalar pion
and photons renders a deviation from the power-law spectrum in the
range. As for scalar quark condensates \left and
virtual loops are relevant only for very high radiation density
and very strong magnetic fields of order .Comment: 15 pages, 4 figures; Final versio
Report 10b: Considerations for the new scheme. Report to Welsh Government (Contract C210/2016/2017).
Gravitational radiation from a particle in circular orbit around a black hole. V. Black-hole absorption and tail corrections
A particle of mass moves on a circular orbit of a nonrotating black
hole of mass . Under the restrictions and , where
is the orbital velocity, we consider the gravitational waves emitted by such a
binary system. We calculate , the rate at which the gravitational
waves remove energy from the system. The total energy loss is given by , where denotes that part of the
gravitational-wave energy which is carried off to infinity, while
denotes the part which is absorbed by the black hole. We show that the
black-hole absorption is a small effect: . We
also compare the wave generation formalism which derives from perturbation
theory to the post-Newtonian formalism of Blanchet and Damour. Among other
things we consider the corrections to the asymptotic gravitational-wave field
which are due to wave-propagation (tail) effects.Comment: ReVTeX, 17 page
Genetic and Phenotypic Features of Schizophrenia in the UK Biobank
IMPORTANCE Large-scale biobanks provide important opportunities for mental health
research, but selection biases raise questions regarding the comparability of individuals
with those in clinical research settings.
OBJECTIVE To compare the genetic liability to psychiatric disorders in individuals with
schizophrenia in the UK Biobank with individuals in the Psychiatric Genomics Consortium
(PGC) and to compare genetic liability and phenotypic features with participants recruited
from clinical settings.
DESIGN, SETTING, AND PARTICIPANTS This cross-sectional study included participants from
the population-based UK Biobank and schizophrenia samples recruited from clinical settings
(CLOZUK, CardiffCOGS, Cardiff F-Series, and Cardiff Affected Sib-Pairs). Data were collected
between January 1993 and July 2021. Data analysis was conducted between July 2021
and June 2023.
MAIN OUTCOMES AND MEASURES A genome-wide association study of UK Biobank
schizophrenia case-control status was conducted, and the results were compared with
those from the PGC via genetic correlations. To test for differences with the clinical samples,
polygenic risk scores (PRS) were calculated for schizophrenia, bipolar disorder, depression,
and intelligence using PRS-CS. PRS and phenotypic comparisons were conducted using
pairwise logistic regressions. The proportions of individuals with copy number variants
associated with schizophrenia were compared using Firth logistic regression.
RESULTS The sample of 517 375 participants included 1438 UK Biobank participants with
schizophrenia (550 [38.2%] female; mean [SD] age, 54.7 [8.3] years), 499 475 UK Biobank
controls (271 884 [54.4%] female; mean [SD] age, 56.5 [8.1] years), and 4 schizophrenia
research samples (4758 [28.9%] female; mean [SD] age, 38.2 [21.0] years). Liability to
schizophrenia in UK Biobank was highly correlated with the latest genome-wide association
study from the PGC (genetic correlation, 0.98; SE, 0.18) and showed the expected patterns
of correlations with other psychiatric disorders. The schizophrenia PRS explained 6.8% of the
variance in liability for schizophrenia case status in UK Biobank. UK Biobank participants with
schizophrenia had significantly lower schizophrenia PRS than 3 of the clinically ascertained
samples and significantly lower rates of schizophrenia-associated copy number variants than
the CLOZUK sample. UK Biobank participants with schizophrenia had higher educational
attainment and employment rates than the clinically ascertained schizophrenia samples,
lower rates of smoking, and a later age of onset of psychosis.
CONCLUSIONS AND RELEVANCE Individuals with schizophrenia in the UK Biobank, and likely
other volunteer-based biobanks, represent those less severely affected. Their inclusion in
wider studies should enhance the representation of the full spectrum of illness severity
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