911 research outputs found
Relativistic descriptions of quasielastic charged-current neutrino-nucleus scattering: application to scaling and superscaling ideas
The analysis of the recent experimental data on charged-current
neutrino-nucleus scattering cross sections measured at MiniBooNE requires fully
relativistic theoretical descriptions also accounting for the role of final
state interactions. In this work we evaluate inclusive quasielastic
differential neutrino cross sections within the framework of the relativistic
impulse approximation. Results based on the relativistic mean field potential
are compared with the ones corresponding to the relativistic Green function
approach. An analysis of scaling and superscaling properties provided by both
models is also presented.Comment: 11 pages, 8 figures, version accepted for publication in Physical
Review
Relativistic descriptions of final-state interactions in charged-current quasielastic neutrino-nucleus scattering at MiniBooNE kinematics
The results of two relativistic models with different descriptions of the
final-state interactions are compared with the MiniBooNE data of
charged-current quasielastic cross sections. The relativistic mean field model
uses the same potential for the bound and ejected nucleon wave functions. In
the relativistic Green's function (RGF) model the final-state interactions are
described in the inclusive scattering consistently with the exclusive
scattering using the same complex optical potential. The RGF results describe
the experimental data for total cross-sections without the need to modify the
nucleon axial mass.Comment: 5 pages 3 figure
Mean-field calculations of exotic nuclei ground states
We study the predictions of three mean-field theoretical approaches in the
description of the ground state properties of some spherical nuclei far from
the stability line. We compare binding energies, single particle spectra,
density distributions, charge and neutron radii obtained with non-relativistic
Hartree-Fock calculations carried out with both zero and finite-range
interactions, and with a relativistic Hartree approach which uses a
finite-range interaction. The agreement between the results obtained with the
three different approaches indicates that these results are more related to the
basic hypotheses of the mean-field approach rather than to its implementation
in actual calculations.Comment: 16 pages, 12 figures, 2 tables, accepted for publication in Physical
Review
Ad- and desorption of Rb atoms on a gold nanofilm measured by surface plasmon polaritons
Hybrid quantum systems made of cold atoms near nanostructured surfaces are
expected to open up new opportunities for the construction of quantum sensors
and for quantum information. For the design of such tailored quantum systems
the interaction of alkali atoms with dielectric and metallic surfaces is
crucial and required to be understood in detail. Here, we present real-time
measurements of the adsorption and desorption of Rubidium atoms on gold
nanofilms. Surface plasmon polaritons (SPP) are excited at the gold surface and
detected in a phase sensitive way. From the temporal change of the SPP phase
the Rubidium coverage of the gold film is deduced with a sensitivity of better
than 0.3 % of a monolayer. By comparing the experimental data with a Langmuir
type adsorption model we obtain the thermal desorption rate and the sticking
probability. In addition, also laser-induced desorption is observed and
quantified.Comment: 9 pages, 6 figure
Myocardial and microvascular injury due to Coronavirus disease 2019
Over the past few months, health systems worldwide have been put to the test with the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Even though the leading clinical manifestations of the SARS-CoV-2 infection involve the respiratory tract, there is a non-negligible risk of systemic involvement leading to the onset of multi-organ failure with fatal consequences. Since the onset of COVID-19, patients with underlying cardiovascular disease have been at increased risk of poor clinical outcomes with higher death rates. Moreover, the occurrence of new-onset cardiac complications is not uncommon among patients hospitalised for COVID-19. Of importance, a significant portion of COVID-19 patients present with myocardial injury. Herein, the authors discuss the mechanisms leading to myocardial and microvascular injury in SARS-CoV-2 infection and their clinical implications
Mammary cistern size during the dry period in healthy dairy cows: A preliminary study for an ultrasonographic evaluation
We evaluated the udder cistern (UC) size during the dry period using ultrasound. Forty healthy quarters were evaluated in both the longitudinal and cross-section of the UC. Quarters were evaluated at the drying-off (T0) and 24 h later (T1), then regularly until the end of the dry period (T7–T58), during the colostrum production phase (TCPP) and at 7 days in milking (T7PP). The Spearman test was applied to find the correlation between the ultrasonographic UC size (UUCS) assessment and time. The Friedman test and Dunn’s test for multiple comparisons as a post-hoc test were performed to compare the forequarter and hindquarter cross-sections (FQCSs and HQCSs, respectively) and the forequarter and hindquarter longitudinal sections (FQLSs and HQLSs, respectively) at T0 vs. T58 vs. TCPP vs. T7PP. A total of 440 images were evaluated. A negative linear correlation between time and FQCS and FQLS (r = −0.95; p < 0.0004) and between time and HQCS and HQLS (r = −0.90; p < 0.002) was found. The UUCS decreased throughout the dry period, starting to increase at the beginning of the next lactation. Measuring the UUCS provides useful information for monitoring the dry period
Inclusive Quasi-Elastic Charged-Current Neutrino-Nucleus Reactions
The Quasi-Elastic (QE) contribution of the nuclear inclusive electron
scattering model developed in Nucl. Phys. A627 (1997) 543 is extended to the
study of electroweak Charged Current (CC) induced nuclear reactions, at
intermediate energies of interest for future neutrino oscillation experiments.
The model accounts for, among other nuclear effects, long range nuclear (RPA)
correlations, Final State Interaction (FSI) and Coulomb corrections.
Predictions for the inclusive muon capture in C and the reaction
C near threshold are also given. RPA correlations are
shown to play a crucial role and their inclusion leads to one of the best
existing simultaneous description of both processes, with accuracies of the
order of 10-15% per cent for the muon capture rate and even better for the LSND
measurement.Comment: 31 pages and 14 figures, accepted for publication as a regular
article in Physical Review
Nuclear effects in charged-current quasielastic neutrino-nucleus scattering
After a short review of the recent developments in studies of
neutrino-nucleus interactions, the predictions for double-differential and
integrated charged current-induced quasielastic cross sections are presented
within two different relativistic approaches: one is the so-called SuSA method,
based on the superscaling behavior exhibited by electron scattering data; the
other is a microscopic model based on relativistic mean field theory, and
incorporating final-state interactions. The role played by the meson-exchange
currents in the two-particle two-hole sector is explored and the results are
compared with the recent MiniBooNE data.Comment: 12 pages, 9 figures, to appear in the Proceedings of "XIII Convegno
di Cortona su Problemi di Fisica Nucleare Teorica", Cortona (Italy), April
6-8, 201
Enrofloxacin against Escherichia coli in turkeys: Which treatment scheme is effective?
Abstract The efficacy of enrofloxacin (ENRO) was evaluated against multidrug-resistant avian pathogenic Escherichia coli correlating the minimum inhibitory concentrations (MIC) of 235 E. coli field strains with its pharmacokinetics (PK) in 50 healthy turkeys (5 groups) with a PK/pharmacodynamic approach. The treatments were as follows: a) single oral gavage and b) single subcutaneous (SC) treatment at the recommended dose of 10 mg/kg; c) single oral gavage, d) 5 d of 10-h pulsed water medication, and e) 5 d of 24-h continuous water medication at the doubled dose of 20 mg/kg. Blood samples were collected at established times over 24 h. Plasma was analyzed using a liquid chromatography tandem mass spectrometry method that was validated in house. A monocompartmental and a noncompartmental model were applied to the data to obtain the PK results. After gavage administration, the mean maximum concentration Cmax/MIC50 and area under the curve AUC0–24/MIC50 ratios were, respectively, 3.07 ± 0.62 and 7.01 ± 1.03 and 25.48 ± 3.04 and 57.2 ± 3.73 for the 10 and 20 mg/kg doses, respectively. After SC administration of 10 mg/kg, Cmax/MIC50 and AUC0–24/MIC50 ratios were 3.45 ± 0.75 and 33.96 ± 7.46, respectively. After the administration of 10-h pulsed or 24-h continuous medicated water at 20 mg/kg, lower values of Cmax/MIC50 (10-h pulsed: 3.45 ± 0.7; 24-h continuous: 3.05 ± 0.48) and AUC0–24/MIC50 (10-h pulsed: 42.42 ± 6.17; 24-h continuous: 53.32 ± 5.55) were obtained. Based on these results, the European Union-recommended dosage of 10 mg/kg seems ineffective to achieve adequate drug plasma concentrations and even the 20 mg/kg by 10 h pulsed or continuous medicated water administration did not reach completely efficacious concentrations in plasma against colibacillosis. Although the results obtained were not completely encouraging, the medicated water should preferably be provided continuously. To conclude about the efficacy of ENRO treatment against colibacillosis, target tissue concentration should be extensively considered
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