3,879 research outputs found
Antiproton and proton collisions with the alkali metal atoms Li, Na, and K
Single-electron ionization and excitation cross sections as well as cross
sections for excitation into the first excited p state of the alkali metal
atoms Li(2s), Na(3s) and K(4s) colliding with antiprotons and protons were
calculated using a time-dependent channel-coupling approach. For antiprotons an
impact-energy range from 0.25 to 1000 keV and for protons from 2 to 1000 keV
was considered. The target atoms are treated as effective one-electron systems
using a model potential. The results are compared with theoretical and
experimental data from literature and calculated cross sections for
antiproton-hydrogen collisions. For proton collisions a good overall agreement
is found which confirms the present numerical approach, whereas discrepancies
are found between the present antiproton cross sections and those calculated by
Stary et al., J.Phys.B 23, 263 (1990)
Resilience and Health-Related Quality of Life Following Discharge From a Level 1 Trauma Center
Trauma can notably impact health-related quality of life (HRQoL) and result in psychiatric symptomology. There is a dearth of longitudinal research examining resilience as a predictor of HRQoL and depression outcomes post-exposure to trauma. This study examines the ability of resilience, as measured by the Connor-Davidson Resilience Scale 10-item (CD-RISC 10), to longitudinally predict mental and physical HRQoL and depression from a Level 1 trauma center at four timepoints: during hospitalization and at three, six, and 12 months post-discharge. Structural equation modeling was used to assess two models of resilience – one conceptualizing it as a latent variable using the CD-RISC 10 items, and the other using the CD-RISC 10 total score – to predict HRQoL and depression overtime. Both models accounted for potential associations with age and gender.
Fit indices indicate that both models evidenced good fit to the data. The models had similar path estimates. Higher resilience was significantly associated with higher mental and physical HRQoL and lower depression at baseline and lower physical HRQoL at three months. Resilience was not significantly associated with HRQoL and depression at other measurement occasions. Age was significantly associated with lower physical HRQoL at baseline and lower depression at six months. Age was not significantly associated with other HRQoL or depression at other measurement occasions. Gender was not significantly associated with HRQoL or depression at any measurement occasion. Depression was consistently associated with subsequent
assessments of depression. Depression was associated with lower mental and physical HRQoL over time, except for physical HRQoL at 12 months. Higher physical HRQoL was significantly associated with higher physical HRQoL at later assessments, and with lower depression at 12 months. Higher mental HRQoL was significantly associated with higher mental HRQoL at later assessments, and with lower depression and physical HRQoL at 12 months. However, baseline mental HRQoL at baseline was not able to predict mental HRQoL at 12 months. Baseline mental HRQoL was significantly associated with lower depression and physical HRQoL at 12 months
Accurate photoionisation cross section for He at non-resonant photon energies
The total single-photon ionisation cross section was calculated for helium
atoms in their ground state. Using a full configuration-interaction approach
the photoionisation cross section was extracted from the complex-scaled
resolvent. In the energy range from ionisation threshold to 59\,eV our results
agree with an earlier -spline based calculation in which the continuum is
box discretised within a relative error of in the non-resonant part of
the spectrum. Above the \He^{++} threshold our results agree on the other
hand very well to a recent Floquet calculation. Thus our calculation confirms
the previously reported deviations from the experimental reference data outside
the claimed error estimate. In order to extend the calculated spectrum to very
high energies, an analytical hydrogenic-type model tail is introduced that
should become asymptotically exact for infinite photon energies. Its
universality is investigated considering also H, Li, and HeH. With
the aid of the tail corrections to the dipole approximation are estimated.Comment: 20 pages, 7 figures, 2 table
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