971 research outputs found
Solar Neutrinos from CNO Electron Capture
The neutrino flux from the sun is predicted to have a CNO-cycle contribution
as well as the known pp-chain component. Previously, only the fluxes from beta+
decays of 13N, 15O, and 17F have been calculated in detail. Another neutrino
component that has not been widely considered is electron capture on these
nuclei. We calculate the number of interactions in several solar neutrino
detectors due to neutrinos from electron capture on 13N, 15O, and 17F, within
the context of the Standard Solar Model. We also discuss possible non-standard
models where the CNO flux is increased.Comment: 4 pages, 1 figure, submitted to Phys. Rev. C; v2 has minor changes
including integration over solar volume and addition of missing reference to
previous continuum electron capture calculation; v3 has minor changes
including addition of references and the correction of a small (about 1%)
numerical error in the table
Positron-neutrino correlation in the 0^+ \to 0^+ decay of ^{32}Ar
The positron-neutrino correlation in the decay of
Ar was measured at ISOLDE by analyzing the effect of lepton recoil on
the shape of the narrow proton group following the superallowed decay. Our
result is consistent with the Standard Model prediction. For vanishing Fierz
interference we find , which yields improved
constraints on scalar weak interactions
rp-Process weak-interaction mediated rates of waiting-point nuclei
Electron capture and positron decay rates are calculated for
neutron-deficient Kr and Sr waiting point nuclei in stellar matter. The
calculation is performed within the framework of pn-QRPA model for rp-process
conditions. Fine tuning of particle-particle, particle-hole interaction
parameters and a proper choice of the deformation parameter resulted in an
accurate reproduction of the measured half-lives. The same model parameters
were used to calculate stellar rates. Inclusion of measured Gamow-Teller
strength distributions finally led to a reliable calculation of weak rates that
reproduced the measured half-lives well under limiting conditions. For the
rp-process conditions, electron capture and positron decay rates on Kr
and Sr are of comparable magnitude whereas electron capture rates on
Sr and Kr are 1--2 orders of magnitude bigger than the
corresponding positron decay rates. The pn-QRPA calculated electron capture
rates on Kr are bigger than previously calculated. The present
calculation strongly suggests that, under rp-process conditions, electron
capture rates form an integral part of weak-interaction mediated rates and
should not be neglected in nuclear reaction network calculations as done
previously.Comment: 13 pages, 4 figures, 4 tables; Astrophysics and Space Science (2012
Spin-Orbit Splitting in Non-Relativistic and Relativistic Self-Consistent Models
The splitting of single-particle energies between spin-orbit partners in
nuclei is examined in the framework of different self-consistent approachs,
non-relativistic as well as relativistic. Analytical expressions of spin-orbit
potentials are given for various cases. Proton spin-orbit splittings are
calculated along some isotopic chains (O, Ca, Sn) and they are compared with
existing data. It is found that the isotopic dependence of the relativistic
mean field predictions is similar to that of some Skyrme forces while the
relativistic Hartree-Fock approach leads to a very different dependence due to
the strong non-locality.Comment: 12 pages, RevTeX, 4 new figs.in .zip format, unchanged conclusions,
Phys. ReV.
Beta-decay in odd-A and even-even proton-rich Kr isotopes
Beta-decay properties of proton-rich odd-A and even-even Krypton isotopes are
studied in the framework of a deformed selfconsistent Hartree-Fock calculation
with density-dependent Skyrme forces, including pairing correlations between
like nucleons in BCS approximation. Residual spin-isospin interactions are
consistently included in the particle-hole and particle-particle channels and
treated in Quasiparticle Random Phase Approximation. The similarities and
differences in the treatment of even-even and odd-A nuclei are stressed.
Comparison to available experimental information is done for Gamow-Teller
strength distributions, summed strengths, and half-lives. The dependence of
these observables on deformation is particularly emphasized in a search for
signatures of the shape of the parent nucleus.Comment: 29 pages, 16 figure
Sri Lankan tsunami refugees: a cross sectional study of the relationships between housing conditions and self-reported health
BACKGROUND: On the 26th December 2004 the Asian tsunami devastated the Sri Lankan coastline. More than two years later, over 14,500 families were still living in transitional shelters. This study compares the health of the internally displaced people (IDP), living in transitional camps with those in permanent housing projects provided by government and non-government organisations in Sri Lanka. METHODS: This study was conducted in seven transitional camps and five permanent housing projects in the south west of Sri Lanka. Using an interviewer-led questionnaire, data on the IDPs' self-reported health and housing conditions were collected from 154 participants from transitional camps and 147 participants from permanent housing projects. Simple tabulation with non-parametric tests and logistic regression were used to identify and analyse relationships between housing conditions and the reported prevalence of specific symptoms. RESULTS: Analysis showed that living conditions were significantly worse in transitional camps than in permanent housing projects for all factors investigated, except 'having a leaking roof'. Transitional camp participants scored significantly lower on self-perceived overall health scores than those living in housing projects. After controlling for gender, age and marital status, living in a transitional camp compared to a housing project was found to be a significant risk factor for the following symptoms; coughs OR: 3.53 (CI: 2.11-5.89), stomach ache 4.82 (2.19-10.82), headache 5.20 (3.09-8.76), general aches and pains 6.44 (3.67-11.33) and feeling generally unwell 2.28 (2.51-7.29). Within transitional camp data, the only condition shown to be a significant risk factor for any symptom was household population density, which increased the risk of stomach aches 1.40 (1.09-1.79) and headaches 1.33 (1.01-1.77). CONCLUSION: Internally displaced people living in transitional camps are a vulnerable population and specific interventions need to be targeted at this population to address the health inequalities that they report to be experiencing. Further studies need to be conducted to establish which aspects of their housing environment predispose them to poorer health
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The Psy-Security-Curriculum ensemble: British Values curriculum policy in English schools
Framed as being in response to terrorist attacks and concerns about religious bias in some English schools, âBritish Valuesâ (BV) curriculum policy forms part of the British Governmentâs Counter-Terrorism and Security Act, 2015. This includes a Duty on teachers in England to actively promote British Values to deter students from radicalisation. This paper, first, traces the history of Britishness in the curriculum to reveal a prevalence of nationalistic, colonial values. Next, an ensemble of recent policies and speeches focusing on British Values is analysed, using a psycho-political approach informed by anti-colonial scholarship. Finally, we interrogate two key critiques of the British Values curriculum discourse: the universality of British Values globally, and concerns over the securitisation of education. Findings indicate that the constitution of white British supremacist subjectivities operate through curriculum as a defence mechanism against perceived threats to white privilege, by normalising a racialised state-controlled social order. The focus is on âBritishâ values, but the analytic framework and findings have wider global significance
Rapid Responders to Frovatriptan in Acute Migraine Treatment: Results from a Long-Term, Open-Label Study
Background. the Chronic Nature of Migraine and the Reliance on Acute Treatment Constitute the Basis of the Present Long-Term, Open-Label Study. Objectives. First, Assessment of the Tolerability and Safety of Frovatriptan, 2.5-7.5 Mg Taken Orally over 24 Hours, for the Acute Treatment of Migraine, Repeatedly over a 12-Month Period. Second, Assessment of the Efficacy and Tolerability of a Second, Double-Blind Dose of 2.5-Mg Frovatriptan, Compared with Placebo, for Nonresponse at 2 Hours after Treatment of Moderate or Severe Headache with 2.5-Mg Frovatriptan. Results. with Regard to the First Attack Treated, 173 (36%) of the 486 Subjects in the Study Did Not Take a Second Dose at 2 Hours for Nonresponse. at 2 Hours and 4 Hours, These Rapid Responders Experienced a Decrease in Headache Intensity from Moderate or Severe to Mild or No Pain in 84% and 98%, Respectively ( Headache Response ). Six Percent of Them Experienced Recurrence of Moderate or Severe Headache within 24 Hours Following a Response at 4 Hours and 12% Took Rescue Medication. the Response, Measured in Terms of Median Time to Complete Migraine Relief, Was Maintained over 30 Subsequent Migraine Attacks, Treated from Attack 2 Onwards over the Course of 12 Months. Conclusion. Frovatriptan Provides a Remarkably Fast and High Headache Response in a Subgroup of More Than One-Third of Migraineurs, with a Very Low 24-Hour Headache Recurrence and Low Rescue Medication Intake. © 2009 American Academy of Pain Medicine
World psychiatric association section of old age psychiatry consensus statement on ethics and capacity in older people with mental disorders
The World Psychiatric Association (WPA) Section of Old Age Psychiatry, since 1997, has developed Consensus Statements relevant to the practice of Old Age Psychiatry. Since 2006 the Section has worked to develop a Consensus Statement on Ethics and Capacity in older people with mental disorders, which was completed in Prague, September 2008, prior to the World Congress in Psychiatry. This Consensus meets one of the goals of the WPA Action Plan 2008â2011, âto promote the highest ethical standards in psychiatric practice and advocate the rights of persons with mental disorders in all regions of the worldâ. This Consensus Statement offers to mental health clinicians caring for older people with mental disorders, caregivers, other health professionals and the general public the setting out of and discourse in ethical principles which can often be complex and challenging, supported by practical guidance in meeting such ethical needs and standards, and to encouraged good clinical practice. Copyright © 2009 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/64443/1/2279_ftp.pd
Social research on neglected diseases of poverty: Continuing and emerging themes
Copyright: © 2009 Manderson et al.Neglected tropical diseases (NTDs) exist and persist for social and economic reasons that enable the vectors and pathogens to take advantage of changes in the behavioral and physical environment. Persistent poverty at household, community, and national levels, and inequalities within and between sectors, contribute to the perpetuation and re-emergence of NTDs. Changes in production and habitat affect the physical environment, so that agricultural development, mining and forestry, rapid industrialization, and urbanization all result in changes in human uses of the environment, exposure to vectors, and vulnerability to infection. Concurrently, political instability and lack of resources limit the capacity of governments to manage environments, control disease transmission, and ensure an effective health system. Social, cultural, economic, and political factors interact and influence government capacity and individual willingness to reduce the risks of infection and transmission, and to recognize and treat disease. Understanding the dynamic interaction of diverse factors in varying contexts is a complex task, yet critical for successful health promotion, disease prevention, and disease control. Many of the research techniques and tools needed for this purpose are available in the applied social sciences. In this article we use this term broadly, and so include behavioral, population and economic social sciences, social and cultural epidemiology, and the multiple disciplines of public health, health services, and health policy and planning. These latter fields, informed by foundational social science theory and methods, include health promotion, health communication, and heath education
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