521 research outputs found
Intrinsic Fano factor of nuclear recoils for dark matter searches
Nuclear recoils in germanium and silicon are shown to have much larger
variance in electron-hole production than their electron-recoil counterparts
for recoil energies between 10 and 200\,keV. This effect--owing primarily to
deviations in the amount of energy given to the crystal lattice in response to
a nuclear recoil of a given energy--has been predicted by the Lindhard model.
We parameterize the variance in terms of an intrinsic nuclear recoil Fano
factor which is 24.30.2 and 268 at around 25\,keV for silicon and
germanium respectively. The variance has important effects on the expected
signal shapes for experiments utilizing low-energy nuclear recoils such as
direct dark matter searches and coherent neutrino-nucleus scattering
measurements.Comment: 9 pages, 6 figure
Neutron capture-induced silicon nuclear recoils for dark matter and CENS
Following neutron capture in a material there will be prompt nuclear recoils
in addition to the gamma cascade. The nuclear recoils that are left behind in
materials are generally below 1\,keV and therefore in the range of interest for
dark matter experiments and CENS studies--both as backgrounds and
calibration opportunities. Here we obtain the spectrum of prompt nuclear
recoils following neutron capture for silicon.Comment: 8 pages, 9 figures, 1 tabl
Effectiveness of antipsychotics in reducing suicidal ideation: Possible physiologic mechanisms
Background: The aim of this study is to evaluate whether any specific antipsychotic regi-men or dosage is effective in managing suicidal ideation in schizophrenia. Four comparisons were conducted between: (1) clozapine and other antipsychotics; (2) long-acting injectable and oral antipsy-chotics; (3) atypical and typical antipsychotics; (4) antipsychotics augmented with antidepressants and antipsychotic treatment without antidepressant augmentation. Methods: We recruited 103 participants diagnosed with schizophrenia spectrum disorders. Participants were followed for at least six months. The Beck Scale for Suicidal Ideation (BSS) was used to assess the severity of suicidal ideation at each visit. We performed a multiple linear regression model controlling for BSS score at study entry and other confounding variables to predict the change in the BSS scores between two visits. Results: Overall, there were 28 subjects treated with clozapine (27.2%), and 21 subjects with depot antipsychotics (20.4%). In our sample, 30 subjects experienced some suicidal ideation at study entry. When considering the entire sample, there was a statistically significant decrease in suicidal ideation severity in the follow-up visit compared to the study entry visit (p = 0.043). Conclusions: To conclude, our preliminary analysis implies that antipsychotics are effective in controlling suicidal ideation in schizophrenia patients, but no difference was found among alternative antipsychotics’ classes or dosages
Production and characterization of a bioartificial and functionalised cardiac patch prototype
Predictive and experimental study of intelligent nanoparticles for controlling cardiac ECM after myocardial infarction
Reactions of a Be-10 beam on proton and deuteron targets
The extraction of detailed nuclear structure information from transfer
reactions requires reliable, well-normalized data as well as optical potentials
and a theoretical framework demonstrated to work well in the relevant mass and
beam energy ranges. It is rare that the theoretical ingredients can be tested
well for exotic nuclei owing to the paucity of data. The halo nucleus Be-11 has
been examined through the 10Be(d,p) reaction in inverse kinematics at
equivalent deuteron energies of 12,15,18, and 21.4 MeV. Elastic scattering of
Be-10 on protons was used to select optical potentials for the analysis of the
transfer data. Additionally, data from the elastic and inelastic scattering of
Be-10 on deuterons was used to fit optical potentials at the four measured
energies. Transfers to the two bound states and the first resonance in Be-11
were analyzed using the Finite Range ADiabatic Wave Approximation (FR-ADWA).
Consistent values of the spectroscopic factor of both the ground and first
excited states were extracted from the four measurements, with average values
of 0.71(5) and 0.62(4) respectively. The calculations for transfer to the first
resonance were found to be sensitive to the size of the energy bin used and
therefore could not be used to extract a spectroscopic factor.Comment: 16 Pages, 10 figure
Susceptibility of hamsters to clostridium difficile isolates of differing toxinotype
Clostridium difficile is the most commonly associated cause of antibiotic associated disease (AAD), which caused ~21,000 cases of AAD in 2011 in the U.K. alone. The golden Syrian hamster model of CDI is an acute model displaying many of the clinical features of C. difficile disease. Using this model we characterised three clinical strains of C. difficile, all differing in toxinotype; CD1342 (PaLoc negative), M68 (toxinotype VIII) and BI-7 (toxinotype III). The naturally occurring non-toxic strain colonised all hamsters within 1-day post challenge (d.p.c.) with high-levels of spores being shed in the faeces of animals that appeared well throughout the entire experiment. However, some changes including increased neutrophil influx and unclotted red blood cells were observed at early time points despite the fact that the known C. difficile toxins (TcdA, TcdB and CDT) are absent from the genome. In contrast, hamsters challenged with strain M68 resulted in a 45% mortality rate, with those that survived challenge remaining highly colonised. It is currently unclear why some hamsters survive infection, as bacterial and toxin levels and histology scores were similar to those culled at a similar time-point. Hamsters challenged with strain BI-7 resulted in a rapid fatal infection in 100% of the hamsters approximately 26 hr post challenge. Severe caecal pathology, including transmural neutrophil infiltrates and extensive submucosal damage correlated with high levels of toxin measured in gut filtrates ex vivo. These data describes the infection kinetics and disease outcomes of 3 clinical C. difficile isolates differing in toxin carriage and provides additional insights to the role of each toxin in disease progression
Scaling study of the pion electroproduction cross sections and the pion form factor
The H()n cross section was measured for a range of
four-momentum transfer up to =3.91 GeV at values of the invariant
mass, , above the resonance region. The -dependence of the longitudinal
component is consistent with the -scaling prediction for hard exclusive
processes. This suggests that perturbative QCD concepts are applicable at
rather low values of . Pion form factor results, while consistent with the
-scaling prediction, are inconsistent in magnitude with perturbative QCD
calculations. The extraction of Generalized Parton Distributions from hard
exclusive processes assumes the dominance of the longitudinal term. However,
transverse contributions to the cross section are still significant at
=3.91 GeV.Comment: 6 pages, 3 figure
Study of the A(e,e') Reaction on H, H, C, Al, Cu and Au
Cross sections for the p()n process on H, H, C,
Al, Cu and Au targets were measured at the Thomas
Jefferson National Accelerator Facility (Jefferson Lab) in order to extract the
nuclear transparencies. Data were taken for four-momentum transfers ranging
from =1.1 to 4.8 GeV for a fixed center of mass energy of =2.14
GeV. The ratio of and was extracted from the measured
cross sections for H, H, C and Cu targets at = 2.15
and 4.0 GeV allowing for additional studies of the reaction mechanism. The
experimental setup and the analysis of the data are described in detail
including systematic studies needed to obtain the results. The results for the
nuclear transparency and the differential cross sections as a function of the
pion momentum at the different values of are presented. Global features
of the data are discussed and the data are compared with the results of model
calculations for the p()n reaction from nuclear targets.Comment: 28 pages, 19 figures, submited to PR
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