1,884 research outputs found
Probing R-parity violating models of neutrino mass at the LHC via top squark decays
It is shown that the R-parity violating decays of the lighter top squarks
() triggered by the lepton number violating couplings
, where the lepton family index i = 1-3, can be
observed at the LHC via the dilepton di-jet channel even if the coupling is as
small as 10 or 10, which is the case in several models of
neutrino mass, provided it is the next lightest supersymmetric particle(NLSP)
the lightest neutralino being the lightest supersymmetric particle(LSP). We
have first obtained a fairly model independent estimate of the minimum
observable value of the parameter ()) at the LHC for an integrated
luminosity of 10fb as a function of \mlstop by a standard Pythia based
analysis. We have then computed the parameter in several
representative models of neutrino mass constrained by the neutrino oscillation
data and have found that the theoretical predictions are above the estimated
minimum observable levels for a wide region of the parameter space.Comment: 19 pages, 1 Figure and 11 Table
New signals of a R-parity violating model of neutrino mass at the Tevatron
In a variety models of neutrino masses and mixings the lighter top squark
decays into competing R - parity violating and R - parity conserving channels.
Using Pythia we have estimated in a model independent way the minimum value of
P BR()
BR(), where and , corresponding
to an observable signal involving the final state
1 + jets +\met (carried by the neutrinos from the
decay) at Tevatron Run II. For the kinematical cuts designed in this paper P
depends on only. We then compute P for representative
choices of the model parameters constrained by the oscillation data and find
that over a significant region of the allowed parameter space P is indeed
larger than . This signal is complementary to the dilepton + dijet
signal studied in several earlier experimental and phenomenological analyses
and may be observed even if BR() is an order of
magnitude smaller than BR(). The
invariant mass distribution of the hardest lepton and the hardest jet may
determine and reveal the lepton number violating nature of
the underlying interaction. The invariant mass distribution of the two lowest
energy jets may determine .Comment: Some minor changes in language are made at pages 1,2,8 and 18
respectivel
Top squark and neutralino decays in a R-parity violating model constrained by neutrino oscillation data
In a R-parity violating (RPV) model of neutrino mass with three bilinear
couplings and three trilinear couplings , where is
the lepton index, we find six generic scenarios each with a distinctive pattern
of the trilinear couplings consistent with the oscillation data. These patterns
may be reflected in direct RPV decays of the lighter top squark or in the RPV
decays of the lightest superparticle, assumed to be the lightest neutralino.
Typical signal sizes at the Tevatron RUN II and the LHC have been estimated
and the results turn out to be encouraging.Comment: 20 pages, 4 figures, LaTex,typos corrected and reference added for
section 2, a paragraph has been added in the conclusion par
A prospective open-label randomized comparative study in Alzheimer’s disease between two commonly used drugs in coastal Indian population
Background: Currently, therapy for Alzheimer’s disease (AD) is only symptomatic. Only two classes of drugs are approved by the United States Food and Drug Administration. Our study aimed at comparing efficacy and safety of memantine and donepezil in moderate to severe AD patients.Methods: Totally, 22 patients with moderate to severe AD were randomized into the 2 arms of the study. The study was divided into an initial 4 weeks for determination of onset of efficacy and subsequent 28 weeks of the treatment phase. Onset of efficacy and response was defined as >20% and >50% reduction in the mean total score of functional dementia scale (FDS) and clinical global impression scale (CGIS) from baseline to the study end, respectively.Results: Onset of efficacy on FDS and CGIS was 16.7% (mean-time 61.25 days) and 80% (mean-time 36 days) with memantine and donepezil, respectively. Response was 89.3% and 40% with memantine and Donepezil, respectively. Total reduction in FDS and CGIS score of from baseline to the study end was 39.50, 40.00, and 25.60, 27.20 with memantine and donepezil, respectively. Tolerability was 86.33% and 20% with memantine and donepezil, respectively. Anorexia, muscle cramps, constipation, headache, and insomnia, were the common side-effects and self-limiting. Safety was 100% in both groups.Conclusions: Onset of efficacy was faster with donepezil seen at 2 weeks. Response, improvement in CGIS, FDS, and tolerability were better seen with memantine at 40 weeks. Thus, in similar clinical settings, memantine can be preferred
Xylazine in the Opioid Epidemic: A Systematic Review of Case Reports and Clinical Implications
Introduction and objectives: The opioid overdose epidemic is exacerbated by the emergence of Xylazine as an illicit drug adulterant. Xylazine, a veterinary sedative, can potentiate opioid effects while also causing toxic and potentially fatal side effects. This systematic review aims to assess the impact of Xylazine use and overdoses within the opioid epidemic context.Method: A systematic search was conducted following PRISMA guidelines to identify relevant case reports, and case series related to Xylazine use. A comprehensive literature search included databases like Web of Science, PubMed, Embase, and Google Scholar, utilizing keywords and Medical Subject Headings (MeSH) terms related to Xylazine. Thirty-four articles met the inclusion criteria for this review.
Results: Intravenous (IV) administration was a common route for Xylazine use among various methods, including subcutaneous (SC), intramuscular (IM), and inhalation, with overall doses ranging from 40 mg to 4300 mg. The average dose in fatal cases was 1,200 mg, compared to 525 mg in non-fatal cases. Concurrent administration of other drugs, primarily opioids, occurred in 28 cases (47.5%). Intoxication was identified as a notable concern in 32 out of 34 studies, and treatments varied, with the majority experiencing positive outcomes. Withdrawal symptoms were documented in one case study, but the low number of cases with withdrawal symptoms may be attributed to factors such as a limited number of cases or individual variation. Naloxone was administered in eight cases (13.6%), and all patients recovered, although it should not be misconstrued as an antidote for Xylazine intoxication. Of the 59 cases, 21 (35.6%) resulted in fatal outcomes, with 17 involving Xylazine use in conjunction with other drugs. The IV route was a common factor in six out of the 21 fatal cases (28.6%).
Conclusion: This review highlights the clinical challenges associated with Xylazine use and its co-administration with other substances, particularly opioids. Intoxication was identified as a major concern, and treatments varied across the studies, including supportive care, naloxone, and other medications. Further research is needed to explore the epidemiology and clinical implications of Xylazine use. Understanding the motivations and circumstances leading to Xylazine use, as well as its effects on users, is essential for developing effective psychosocial support and treatment interventions to address this public health crisis
Vortex fluctuations in superconducting La-Sr-Cu-O
Vortex fluctuations in the system have been
studied as a function of magnetic field, temperature and carrier concentration
in order to determine the dimensionality of the fluctuations. For a
sample, there is a unique crossing-temperature on the magnetization vs.
temperature plots for all magnetic fields up to 7 T, and the data scale very
well with 2D fluctuation theory. At lower x-values where is much
smaller, there are two well defined crossing points, one at low fields
(typically less than 1 T) and another at high fields (typically 3-7 T). A fit
of the data to fluctuation theory shows that the low field crossing data scale
as 2D fluctuations and the high field crossing data scale as 3D fluctuations.
It would appear that as the magnetic field approaches , there is a 2D
to 3D cross-over where the low field 2D pancake vortex structure transforms
into a 3D vortex structure
Effect of size reduction on the ferromagnetism of the manganite La1-xCaxMnO3 (x = 0.33)
In this paper we report an investigation on the ferromagnetic state and the
nature of ferromagnetic transition of nanoparticles of
using magnetic measurements and neutron
diffraction. The investigation was made on nanoparticles with crystal size down
to nm. The neutron data show that even down to a size of nm the
nanoparticles show finite spontaneous magnetization () although the value
is much reduced compared to the bulk sample. We observed a non-monotonic
variation of the ferromagnetic to paramagnetic transition temperature
with size and found that initially enhances on size reduction, but
for nm it decreases again. The initial enhancement in was
related to an increase in the bandwidth that occured due to a compaction of the
Mn-O bond length and a straightening of the Mn-O-Mn bond angle, as determined
form the neutron data. The size reduction also changes the nature of the
ferromagnetic to paramagnetic transition from first order to second order with
critical exponents approaching mean field values. This was explained as arising
from a truncation of the coherence length by the finite sample size.Comment: 12 figure
Scaling of the Equilibrium Magnetization in the Mixed State of Type-II Superconductors
We discuss the analysis of mixed-state magnetization data of type-II
superconductors using a recently developed scaling procedure. It is based on
the fact that, if the Ginzburg-Landau parameter kappa does not depend on
temperature, the magnetic susceptibility is a universal function of H/H_c2(T),
leading to a simple relation between magnetizations at different temperatures.
Although this scaling procedure does not provide absolute values of the upper
critical fieldH_c2(T), its temperature variation can be established rather
accurately. This provides an opportunity to validate theoretical models that
are usually employed for the evaluation of H_c2(T) from equilibrium
magnetization data. In the second part of the paper we apply this scaling
procedure for a discussion of the notorious first order phase transition in the
mixed state of high temperature superconductors. Our analysis, based on
experimental magnetization data available in the literature, shows that the
shift of the magnetization accross the transition may adopt either sign,
depending on the particular chosen sample. We argue that this observation is
inconsistent with the interpretation that this transition always represents the
melting transition of the vortex lattice.Comment: 18 pages, 12 figure
Do health education initiatives assist socioeconomically disadvantaged populations? : a systematic review and meta-analyses
Background: Health education interventions are considered critical for the prevention and management of conditions of public health concern. Although the burden of these conditions is often greatest in socio-economically disadvantaged populations, the effectiveness of interventions that target these groups is unknown. We aimed to identify and synthesize evidence of the effectiveness of health-related educational interventions in adult disadvantaged populations. Methods: We pre-registered the study on Open Science Framework https://osf.io/ek5yg/. We searched Medline, Embase, Emcare, and the Cochrane Register from inception to 5/04/2022 to identify studies evaluating the effectiveness of health-related educational interventions delivered to adults in socio-economically disadvantaged populations. Our primary outcome was health related behaviour and our secondary outcome was a relevant biomarker. Two reviewers screened studies, extracted data and evaluated risk of bias. Our synthesis strategy involved random-effects meta-analyses and vote-counting. Results: We identified 8618 unique records, 96 met our criteria for inclusion – involving more than 57,000 participants from 22 countries. All studies had high or unclear risk of bias. For our primary outcome of behaviour, meta-analyses found a standardised mean effect of education on physical activity of 0.05 (95% confidence interval (CI) = -0.09–0.19), (5 studies, n = 1330) and on cancer screening of 0.29 (95% CI = 0.05–0.52), (5 studies, n = 2388). Considerable statistical heterogeneity was present. Sixty-seven of 81 studies with behavioural outcomes had point estimates favouring the intervention (83% (95% CI = 73%-90%), p < 0.001); 21 of 28 studies with biomarker outcomes showed benefit (75% (95%CI = 56%-88%), p = 0.002). When effectiveness was determined based on conclusions in the included studies, 47% of interventions were effective on behavioural outcomes, and 27% on biomarkers. Conclusions: Evidence does not demonstrate consistent, positive impacts of educational interventions on health behaviours or biomarkers in socio-economically disadvantaged populations. Continued investment in targeted approaches, coinciding with development of greater understanding of factors determining successful implementation and evaluation, are important to reduce inequalities in health
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