1,196 research outputs found
Impact on South African meat demand of a possible free trade agreement with the European Union
The Rotterdam model is used to estimate a demand system for South African (SA) beef, chicken, mutton and pork during 1971-1995 and identify the potential impacts on demand for these meat types of a Free Trade Agreement (FTA) between SA and the European Union. Conditional cross-price Slutsky elasticity estimates show that for a given 1% change in each meat price under an FTA, the beef price change would have the largest impact on consumption of the other meats. The net effect of the FTA would depend on the extent to which different meat prices fall if meat imports increase. Import competition may be felt particularly from poultry imports as most of SA beef imports are of a low quality.International Relations/Trade, Livestock Production/Industries,
Compact boson stars in K field theories
We study a scalar field theory with a non-standard kinetic term minimally
coupled to gravity. We establish the existence of compact boson stars, that is,
static solutions with compact support of the full system with self-gravitation
taken into account. Concretely, there exist two types of solutions, namely
compact balls on the one hand, and compact shells on the other hand. The
compact balls have a naked singularity at the center. The inner boundary of the
compact shells is singular, as well, but it is, at the same time, a Killing
horizon. These singular, compact shells therefore resemble black holes.Comment: Latex, 45 pages, 25 figures, some references and comments adde
(B-L) Symmetry vs. Neutrino Seesaw
We compute the effective coupling of the Majoron to W bosons at \cO(\hbar)
by evaluating the matrix element of the (B-L) current between the vacuum and a
state. The (B-L) anomaly vanishes, but the amplitude does not vanish
as a result of a UV finite and non-local contribution which is entirely due to
the mixing between left-chiral and right-chiral neutrinos. The result shows how
anomaly-like couplings may arise in spite of the fact that the (B-L) current
remains exactly conserved to all orders in , lending additional support
to our previous proposal to identify the Majoron with the axion.Comment: 13 pages, 1 figure, with additional explanations and clarification
Draft genome sequence of Escherichia coli O157:H7 ATCC 35150 and a nalidixic acid-resistant mutant derivative
Shiga toxin-producing Escherichia coli strains, occasionally isolated from food, are of public health importance. Here, we report on the 5.30-Mbp draft genome sequence of E. coli O157:H7 EDL931 (strain ATCC 35150) and the 5.32-Mbp draft genome sequence of a nalidixic acid-resistant mutant derivative used as a distinguishable control strain in food-testing laboratories
Recommended from our members
A proposal for reducing maximum target doses of drugs for psychosis: Reviewing dose-response literature
YesBackground:
Presently, there is limited guidance on the maximal dosing of psychosis drugs that is based on effectiveness rather than safety or toxicity. Current maximum dosing recommendations may far exceed the necessary degree of dopamine D2 receptor blockade required to treat psychosis. This may lead to excess harm through cognitive impairment and side effects.
Aims:
This analysis aimed to establish guidance for prescribers by optimally dosing drugs for psychosis based on efficacy and benefit.
Methods:
We used data from two dose–response meta-analyses and reviewed seven of the most prescribed drugs for psychosis in the UK. Where data were not available, we used appropriate comparison techniques based on D2 receptor occupancy to extrapolate our recommendations.
Results:
We found that the likely threshold dose for achieving remission of psychotic symptoms was often significantly below the currently licensed dose for these drugs. We therefore recommend that clinicians are cautious about exceeding our recommended doses. Individual factors, however, should be accounted for. We outline potentially relevant factors including age, ethnicity, sex, smoking status and pharmacogenetics. Additionally, we recommend therapeutic drug monitoring as a tool to determine individual pharmacokinetic variation.
Conclusions:
In summary, we propose a new set of maximum target doses for psychosis drugs based on efficacy. Further research through randomised controlled trials should be undertaken to evaluate the effect of reducing doses from current licensing maximums or from doses that are above our recommendations. However, dose reductions should be implemented in a manner that accounts for and reduces the effects of drug withdrawal
Supersymmetry with a Chargino NLSP and Gravitino LSP
We demonstrate that the lightest chargino can be lighter than the lightest
neutralino in supersymmetric models with Dirac gaugino masses as well as within
a curious parameter region of the MSSM. Given also a light gravitino, such as
from low scale supersymmetry breaking, this mass hierarchy leads to an unusual
signal where every superpartner cascades down to a chargino that decays into an
on-shell W and a gravitino, possibly with a macroscopic chargino track. We
clearly identify the region of parameters where this signal can occur. We find
it is generic in the context of the R-symmetric supersymmetric standard model,
whereas it essentially only occurs in the MSSM when sign(M1) is not equal to
sign(M2) = sign(\mu) and tan(beta) is small. We briefly comment on the search
strategies for this signal at the LHC.Comment: 27 pages and 16 figure
Cosmic Chronometers: Constraining the Equation of State of Dark Energy. I: H(z) Measurements
We present new determinations of the cosmic expansion history from
red-envelope galaxies. We have obtained for this purpose high-quality spectra
with the Keck-LRIS spectrograph of red-envelope galaxies in 24 galaxy clusters
in the redshift range 0.2 < z < 1.0. We complement these Keck spectra with
high-quality, publicly available archival spectra from the SPICES and VVDS
surveys. We improve over our previous expansion history measurements in Simon
et al. (2005) by providing two new determinations of the expansion history:
H(z) = 97 +- 62 km/sec/Mpc at z = 0.5 and H(z) = 90 +- 40 km/sec/Mpc at z =
0.8. We discuss the uncertainty in the expansion history determination that
arises from uncertainties in the synthetic stellar-population models. We then
use these new measurements in concert with cosmic-microwave-background (CMB)
measurements to constrain cosmological parameters, with a special emphasis on
dark-energy parameters and constraints to the curvature. In particular, we
demonstrate the usefulness of direct H(z) measurements by constraining the
dark- energy equation of state parameterized by w0 and wa and allowing for
arbitrary curvature. Further, we also constrain, using only CMB and H(z) data,
the number of relativistic degrees of freedom to be 4 +- 0.5 and their total
mass to be < 0.2 eV, both at 1-sigma.Comment: Submitted to JCA
The Leptonic Higgs as a Messenger of Dark Matter
We propose that the leptonic cosmic ray signals seen by PAMELA and ATIC
result from the annihilation or decay of dark matter particles via states of a
leptonic Higgs doublet to leptons, linking cosmic ray signals of dark
matter to LHC signals of the Higgs sector. The states of the leptonic Higgs
doublet are lighter than about 200 GeV, yielding large and
event rates at the LHC. Simple models are
given for the dark matter particle and its interactions with the leptonic
Higgs, for cosmic ray signals arising from both annihilations and decays in the
galactic halo. For the case of annihilations, cosmic photon and neutrino
signals are on the verge of discovery.Comment: 34 pages, 9 figures, minor typos corrected, references adde
RGDS peptides immobilized on titanium alloy stimulate bone cell attachment, differentiation and confer resistance to apoptosis
A major cause of implant failure in skeletal tissues is failure of osseointegration, often due to lack of adhesion of cells to the titanium (Ti) alloy interface. Since arginine- glycine-aspartic acid (RGD)-containing peptides have been shown to regulate osteoblast adhesion, we tested the hypothesis that, bound to a Ti surface, these peptides would promote osteoblasts differentiation, while at the same time inhibit apoptosis. RGDS and RGES (control) peptides were covalently linked to Ti discs using an APTS linker. While the grafting of both RGDS and RGES significantly increased Ti surface roughness, contact angle analysis showed that APTS significantly increased the surface hydrophobicity; when the peptides were tethered to Ti, this was reduced. To evaluate attachment, MC3T3-E1 osteoblast cells were grown on these discs. Significantly more cells attached to the Ti-grafted RGDS then the Ti-grafted RGES control. Furthermore, expression of the osteoblasts phenotype was significantly enhanced on the Ti-grafted RGDS surface. When cells attached to the Ti-grafted RGDS were challenged with staurosporine, an apoptogen, there was significant inhibition of apoptosis; in contrast, osteoblasts adherent to the Ti-grafted RGES were killed. It is concluded that RGD-containing peptides covalently bonded to Ti promotes osteoblasts attachment and survival with minimal changes to the surface of the alloy. Therefore, such modifications to Ti would have the potential to promote osseointegration in vivo
Recommended from our members
Proportion of Antipsychotics with CYP2D6 Pharmacogenetic (PGx) Associations Prescribed in an Early Intervention in Psychosis (EIP) Cohort: A Cross-Sectional Study
YesBackground: Prescribing drugs for psychosis (antipsychotics) is challenging due to high rates of poor treatment outcomes, which are in part explained
by an individual’s genetics. Pharmacogenomic (PGx) testing can help clinicians tailor the choice or dose of psychosis drugs to an individual’s genetics,
particularly psychosis drugs with known variable response due to CYP2D6 gene variants (‘CYP2D6-PGx antipsychotics’).
Aims: This study aims to investigate differences between demographic groups prescribed ‘CYP2D6-PGx antipsychotics’ and estimate the proportion of
patients eligible for PGx testing based on current pharmacogenomics guidance.
Methods: A cross-sectional study took place extracting data from 243 patients’ medical records to explore psychosis drug prescribing, including drug
transitions. Demographic data such as age, sex, ethnicity, and clinical sub-team were collected and summarised. Descriptive statistics explored the
proportion of ‘CYP2D6-PGx antipsychotic’ prescribing and the nature of transitions. We used logistic regression analysis to investigate associations
between demographic variables and prescription of ‘CYP2D6-PGx antipsychotic’ versus ‘non-CYP2D6-PGx antipsychotic’.
Results: Two-thirds (164) of patients had been prescribed a ‘CYP2D6-PGx antipsychotic’ (aripiprazole, risperidone, haloperidol or zuclopenthixol).
Over a fifth (23%) of patients would have met the suggested criteria for PGx testing, following two psychosis drug trials. There were no statistically
significant differences between age, sex, or ethnicity in the likelihood of being prescribed a ‘CYP2D6-PGx antipsychotic’.
Conclusions: This study demonstrated high rates of prescribing ‘CYP2D6-PGx-antipsychotics’ in an EIP cohort, providingThis research was supported by the National Institute for Health and Care Research (NIHR) Yorkshire and Humber Patient Safety Translational Research Centre (NIHR Yorkshire and Humber PSTRC). This research has been funded through a scholarship from the Bradford District Care NHS Foundation Trust in partnership with the University of Bradford
- …