259 research outputs found
The COVID-19 Pandemic Mental Health Questionnaire (CoPaQ): psychometric evaluation and compliance with countermeasures in psychiatric inpatients and non-clinical individuals
BACKGROUND The COVID-19 pandemic has greatly impacted people's lives across a broad spectrum of psychosocial domains. We report the development and psychometric evaluation of the self-report COVID-19 Pandemic Mental Health Questionnaire (CoPaQ), which assesses COVID-19 contamination anxiety, countermeasure necessity and compliance, mental health impact, stressor impact, social media usage, interpersonal conflicts, paranoid ideations, institutional & political trust, conspiracy beliefs, and social cohesion. Further, we illustrate the questionnaire's utility in an applied example investigating if higher SARS-Cov-2 infection rates in psychiatric patients could be explained by reduced compliance with preventive countermeasures. METHODS A group of 511 non-clinical individuals completed an initial pool of 111 CoPaQ items (Open Science Framework: https://osf.io/3evn9/ ) and additional scales measuring psychological distress, well-being, and paranoia to assess construct validity and lifetime mental health diagnosis for criterion validity. Factor structure was determined by exploratory factor analyses and validated by conducting confirmatory factor analysis in the accompanying longitudinal sample (n~= 318) and an independent psychiatric inpatient sample primarily admitted for major depressive-, substance abuse-, personality-, and anxiety disorders (n~= 113). Internal consistency was assessed by Cronbach's Alpha and McDonald's Omega. For the applied research example, Welch t-tests and correlational analyses were conducted. RESULTS Twelve out of 16 extracted subscales were retained in the final questionnaire version, which provided preliminary evidence for adequate psychometric properties in terms of factor structure, internal consistency, and construct and criterion validity. Our applied research example showed that patients exhibited greater support for COVID-19 countermeasures than non-clinical individuals. However, this requires replication in future studies. CONCLUSIONS We demonstrate that the CoPaQ is a comprehensive and valid measure of the psychosocial impact of the pandemic and could allow to a degree to disentangle the complex psychosocial phenomena of the pandemic as exemplified by our applied analyses
Differential psychological response to the COVID-19 pandemic in psychiatric inpatients compared to a non-clinical population from Germany
The COVID-19 pandemic is an inherently stressful situation, which may lead to adverse psychosocial outcomes in various populations. Yet, individuals may not be affected equally by stressors posed by the pandemic and those with pre-existing mental disorders could be particularly vulnerable. To test this hypothesis, we assessed the psychological response to the pandemic in a case-control design. We used an age-, sex- and employment status-matched case-control sample (n = 216) of psychiatric inpatients, recruited from the LMU Psychiatry Biobank Munich study and non-clinical individuals from the general population. Participants completed validated self-report measures on stress, anxiety, depression, paranoia, rumination, loneliness, well-being, resilience, and a newly developed index of stressors associated with the COVID-19 pandemic. Multiple linear regression analyses were conducted to assess the effects of group, COVID-19-specific stressors, and their interaction on the different psychosocial outcomes. While psychiatric inpatients reported larger mental health difficulties overall, the impact of COVID-19-specific stressors was lower in patients and not associated with worse psychological functioning compared to non-clinical individuals. In contrast, depressive symptoms, rumination, loneliness, and well-being were more strongly associated with COVID-19-specific stressors in non-clinical individuals and similar to the severity of inpatients for those who experienced the greatest COVID-19-specific stressor impact Contrary to expectations, the psychological response to the pandemic may not be worse in psychiatric inpatients compared to non-clinical individuals. Yet, individuals from the general population, who were hit hardest by the pandemic, should be monitored and may be in need of mental health prevention and treatment efforts
Spontaneous emission of an atom in front of a mirror
Motivated by a recent experiment [J. Eschner {\it et al.}, Nature {\bf 413},
495 (2001)], we now present a theoretical study on the fluorescence of an atom
in front of a mirror. On the assumption that the presence of the distant mirror
and a lens imposes boundary conditions on the electric field in a plane close
to the atom, we derive the intensities of the emitted light as a function of an
effective atom-mirror distance. The results obtained are in good agreement with
the experimental findings.Comment: 8 pages, 6 figures, revised version, references adde
Resonance fluorescence of a trapped three-level atom
We investigate theoretically the spectrum of resonance fluorescence of a
harmonically trapped atom, whose internal transitions are --shaped and
driven at two-photon resonance by a pair of lasers, which cool the
center--of--mass motion. For this configuration, photons are scattered only due
to the mechanical effects of the quantum interaction between light and atom. We
study the spectrum of emission in the final stage of laser--cooling, when the
atomic center-of-mass dynamics is quantum mechanical and the size of the wave
packet is much smaller than the laser wavelength (Lamb--Dicke limit). We use
the spectral decomposition of the Liouville operator of the master equation for
the atomic density matrix and apply second order perturbation theory. We find
that the spectrum of resonance fluorescence is composed by two narrow sidebands
-- the Stokes and anti-Stokes components of the scattered light -- while all
other signals are in general orders of magnitude smaller. For very low
temperatures, however, the Mollow--type inelastic component of the spectrum
becomes visible. This exhibits novel features which allow further insight into
the quantum dynamics of the system. We provide a physical model that interprets
our results and discuss how one can recover temperature and cooling rate of the
atom from the spectrum. The behaviour of the considered system is compared with
the resonance fluorescence of a trapped atom whose internal transition consists
of two-levels.Comment: 11 pages, 4 Figure
Quantum jumps induced by the center-of-mass motion of a trapped atom
We theoretically study the occurrence of quantum jumps in the resonance
fluorescence of a trapped atom. Here, the atom is laser cooled in a
configuration of level such that the occurrence of a quantum jump is associated
to a change of the vibrational center-of-mass motion by one phonon. The
statistics of the occurrence of the dark fluorescence period is studied as a
function of the physical parameters and the corresponding features in the
spectrum of resonance fluorescence are identified. We discuss the information
which can be extracted on the atomic motion from the observation of a quantum
jump in the considered setup
Narrow Spectral Feature In Resonance Fluorescence With A Single Monochromatic Laser Field
We describe the resonance fluorescence spectrum of an atomic three-level
system where two of the states are coupled by a single monochromatic laser
field. The influence of the third energy level, which interacts with the two
laser-coupled states only via radiative decays, is studied in detail. For a
suitable choice of parameters, this system gives rise to a very narrow
structure at the laser frequency in the fluorescence spectrum which is not
present in the spectrum of a two-level atom. We find those parameter ranges by
a numerical analysis and use the results to derive analytical expressions for
the additional narrow peak. We also derive an exact expression for the peak
intensity under the assumption that a random telegraph model is applicable to
the system. This model and a simple spring model are then used to describe the
physical origins of the additional peak. Using these results, we explain the
connection between our system, a three-level system in V-configuration where
both transitions are laser driven, and a related experiment which was recently
reported.Comment: 14 pages, 15 figures, extension of the spring mode
Size-resolved online chemical analysis of nanoaerosol particles: a thermal desorption differential mobility analyzer coupled to a chemical ionization time-of-flight mass spectrometer
A new method for size-resolved chemical analysis of nucleation
mode aerosol particles (size range from ââŒâ10 to ââŒâ30 nm) is presented. The Thermal Desorption Differential Mobility Analyzer
(TD-DMA) uses an online, discontinuous principle. The particles are charged,
a specific size is selected by differential mobility analysis and they are
collected on a filament by electrostatic precipitation. Subsequently, the
sampled mass is evaporated in a clean carrier gas and analyzed by a chemical
ionization mass spectrometer. Gas-phase measurements are performed with the
same mass spectrometer during the sampling of particles. The characterization
shows reproducible results, with a particle size resolution of 1.19 and the
transmission efficiency for 15 nm particles being slightly above 50 %. The
signal from the evaporation of a test substance can be detected starting from
0.01 ng and shows a linear response in the mass spectrometer. Instrument
operation in the range of pg mâ3 is demonstrated by an example
measurement of 15 nm particles produced by nucleation from dimethylamine,
sulfuric acid and water.</p
Resonance Fluorescence Spectrum of a Trapped Ion Undergoing Quantum Jumps
We experimentally investigate the resonance fluorescence spectrum of single
171Yb and 172Yb ions which are laser cooled to the Lamb-Dicke regime in a
radiofrequency trap. While the fluorescence scattering of 172Yb is continuous,
the 171Yb fluorescence is interrupted by quantum jumps because a nonvanishing
rate of spontaneous transitions leads to electron shelving in the metastable
hyperfine sublevel 2D3/2(F=2). The average duration of the resulting dark
periods can be varied by changing the intensity of a repumping laser field.
Optical heterodyne detection is employed to analyze the fluorescence spectrum
near the Rayleigh elastic scattering peak. It is found that the stochastic
modulation of the fluorescence emission by quantum jumps gives rise to a
Lorentzian component in the fluorescence spectrum, and that the linewidth of
this component varies according to the average duration of the dark
fluorescence periods. The experimental observations are in quantitative
agreement with theoretical predictions.Comment: 14 pages including 4 figures, pdf file, fig.1 replace
Predictors and outcomes in primary depression care (POKAL) â a research training group develops an innovative approach to collaborative care
BACKGROUND: The interdisciplinary research training group (POKAL) aims to improve care for patients with depression and multimorbidity in primary care. POKAL includes nine projects within the framework of the Chronic Care Model (CCM). In addition, POKAL will train young (mental) health professionals in research competences within primary care settings. POKAL will address specific challenges in diagnosis (reliability of diagnosis, ignoring suicidal risks), in treatment (insufficient patient involvement, highly fragmented care and inappropriate long-time anti-depressive medication) and in implementation of innovations (insufficient guideline adherence, use of irrelevant patient outcomes, ignoring relevant context factors) in primary depression care. METHODS: In 2021 POKAL started with a first group of 16 trainees in general practice (GPs), pharmacy, psychology, public health, informatics, etc. The program is scheduled for at least 6Â years, so a second group of trainees starting in 2024 will also have three years of research-time. Experienced principal investigators (PIs) supervise all trainees in their specific projects. All projects refer to the CCM and focus on the diagnostic, therapeutic, and implementation challenges. RESULTS: The first cohort of the POKAL research training group will develop and test new depression-specific diagnostics (hermeneutical strategies, predicting models, screening for suicidal ideation), treatment (primary-care based psycho-education, modulating factors in depression monitoring, strategies of de-prescribing) and implementation in primary care (guideline implementation, use of patient-assessed data, identification of relevant context factors). Based on those results the second cohort of trainees and their PIs will run two major trials to proof innovations in primary care-based a) diagnostics and b) treatment for depression. CONCLUSION: The research and training programme POKAL aims to provide appropriate approaches for depression diagnosis and treatment in primary care
Reducing the prosthesis modulus by inclusion of an open space lattice improves osteogenic response in a sheep model of extraarticular defect
Introduction: Stress shielding is a common complication following endoprosthetic reconstruction surgery. The resulting periprosthetic osteopenia often manifests as catastrophic fractures and can significantly limit future treatment options. It has been long known that bone plates with lower elastic moduli are key to reducing the risk of stress shielding in orthopedics. Inclusion of open space lattices in metal endoprostheses is believed to reduce the prosthesis modulus potentially improving stress shielding. However, no in vivo data is currently available to support this assumption in long bone reconstruction. This manuscript aims to address this hypothesis using a sheep model of extraarticular bone defect.Methods: Initially, CT was used to create a virtual resection plan of the distal femoral metaphyses and to custom design endoprostheses specific to each femur. The endoprostheses comprised additively manufactured Ti6Al4V-ELI modules that either had a solid core with a modulus of âŒ120 GPa (solid implant group) or an open space lattice core with unit cells that had a modulus of 3â6 GPa (lattice implant group). Osteotomies were performed using computer-assisted navigation followed by implantations. The periprosthetic, interfacial and interstitial regions of interest were evaluated by a combination of micro-CT, back-scattered scanning electron microscopy (BSEM), as well as epifluorescence and brightfield microscopy.Results: In the periprosthetic region, mean pixel intensity (a proxy for tissue mineral density in BSEM) in the caudal cortex was found to be higher in the lattice implant group. This was complemented by BSEM derived porosity being lower in the lattice implant group in both caudal and cranial cortices. In the interfacial and interstitial regions, most pronounced differences were observed in the axial interfacial perimeter where the solid implant group had greater bone coverage. In contrast, the lattice group had a greater coverage in the cranial interfacial region.Conclusion: Our findings suggest that reducing the prosthesis modulus by inclusion of an open-space lattice in its design has a positive effect on bone material and morphological parameters particularly within the periprosthetic regions. Improved mechanics appears to also have a measurable effect on the interfacial osteogenic response and osteointegration
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