119 research outputs found
Real-time diffuse optical tomography using reduced-order light propagation models based on a priori anatomical and functional information
This paper proposes a new fast 3D image reconstruction
algorithm for Diffuse Optical Tomography using reduced
order polynomial mappings from the space of optical
tissue parameters into the space of flux measurements at
the detector locations. The polynomial mappings are
constructed through an iterative estimation process
involving structure detection, parameter estimation and
cross-validation using data generated by simulating a
diffusion approximation of the radiative transfer equation
incorporating a priori anatomical and functional
information provided by MR scans and prior psychological
evidence. Numerical simulation studies demonstrate that
reconstructed images are remarkably similar in quality as
those obtained using the standard approach, but obtained at
a fraction of the time
Illusory Decoherence
If a quantum experiment includes random processes, then the results of
repeated measurements can appear consistent with irreversible decoherence even
if the system's evolution prior to measurement was reversible and unitary. Two
thought experiments are constructed as examples.Comment: 10 pages, 3 figure
Long-Term Consequences of Methamphetamine Exposure in Young Adults Are Exacerbated in Glial Cell Line-Derived Neurotrophic Factor Heterozygous Mice
Methamphetamine abuse in young adults has long-term deleterious effects on brain function that are associated with damage to monoaminergic neurons. Administration of glial cell line-derived neurotrophic factor (GDNF) protects dopamine neurons from the toxic effects of methamphetamine in animal models. Therefore, we hypothesized that a partial GDNF gene deletion would increase the susceptibility of mice to methamphetamine neurotoxicity during young adulthood and possibly increase age-related deterioration of behavior and dopamine function. Two weeks after a methamphetamine binge (4 x 10 mg/kg, i.p., at 2 h intervals), GDNF +/- mice had a significantly greater reduction of tyrosine hydroxylase immunoreactivity in the medial striatum, a proportionally greater depletion of dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) levels in the striatum, and a greater increase in activated microglia in the substantia nigra than wild-type mice. At 12 months of age, methamphetamine-treated GDNF +/- mice exhibited less motor activity and lower levels oftyrosine hydroxylase-immunoreactivity, dopamine, DOPAC, and serotoninthanwild-typemice. Greater striatal dopaminetransporter activity in GDNF +/- mice may underlie their differential response to methamphetamine. These data suggest the possibility that methamphetamine use in young adults, when combined with lower levels of GDNF throughout life, may precipitate the appearance of parkinsonian-like behaviors during aging
Effect of Varying Repositioning Frequency on Pressure Injury Prevention in Nursing Home Residents: TEAM-UP Trial Results
OBJECTIVE: To investigate the clinical effectiveness of three nursing-home-wide repositioning intervals (2-, 3-, or 4-hour) without compromising pressure injury (PrI) incidence in 4 weeks. METHODS: An embedded pragmatic cluster randomized controlled trial was conducted in nine nursing homes (NHs) that were randomly assigned to one of three repositioning intervals. Baseline (12 months) and 4-week intervention data were provided during the TEAM-UP (Turn Everyone And Move for Ulcer Prevention) study. Intervention residents were without current PrIs, had PrI risk (Braden Scale score) ≥10 (not severe risk), and used viable 7-inch high-density foam mattresses. Each arm includes three NHs with an assigned single repositioning interval (2-, 3-, or 4-hour) as standard care during the intervention. A wireless patient monitoring system, using wearable single-use patient sensors, cued nursing staff by displaying resident repositioning needs on conveniently placed monitors. The primary outcome was PrI incidence; the secondary outcome was staff repositioning compliance fidelity. RESULTS: From May 2017 to October 2019, 1,100 residents from nine NHs were fitted with sensors; 108 of these were ineligible for some analyses because of missing baseline data. The effective sample size included 992 residents (mean age, 78 ± 13 years; 63% women). The PrI incidence during the intervention was 0.0% compared with 5.24% at baseline, even though intervention resident clinical risk scores were significantly higher (P < .001). Repositioning compliance for the 4-hour repositioning interval (95%) was significantly better than for the 2-hour (80%) or 3-hour (90%) intervals (P < .001). CONCLUSIONS: Findings suggest that current 2-hour protocols can be relaxed for many NH residents without compromising PrI prevention. A causal link was not established between repositioning interval treatments and PrI outcome; however, no new PrIs developed. Compliance improved as repositioning interval lengthened
Interventions aimed at improving the nursing work environment: a systematic review
<p>Abstract</p> <p>Background</p> <p>Nursing work environments (NWEs) in Canada and other Western countries have increasingly received attention following years of restructuring and reported high workloads, high absenteeism, and shortages of nursing staff. Despite numerous efforts to improve NWEs, little is known about the effectiveness of interventions to improve NWEs. The aim of this study was to review systematically the scientific literature on implemented interventions aimed at improving the NWE and their effectiveness.</p> <p>Methods</p> <p>An online search of the databases CINAHL, Medline, Scopus, ABI, Academic Search Complete, HEALTHstar, ERIC, Psychinfo, and Embase, and a manual search of Emerald and Longwoods was conducted. (Quasi-) experimental studies with pre/post measures of interventions aimed at improving the NWE, study populations of nurses, and quantitative outcome measures of the nursing work environment were required for inclusion. Each study was assessed for methodological strength using a quality assessment and validity tool for intervention studies. A taxonomy of NWE characteristics was developed that would allow us to identify on which part of the NWE an intervention targeted for improvement, after which the effects of the interventions were examined.</p> <p>Results</p> <p>Over 9,000 titles and abstracts were screened. Eleven controlled intervention studies met the inclusion criteria, of which eight used a quasi-experimental design and three an experimental design. In total, nine different interventions were reported in the included studies. The most effective interventions at improving the NWE were: primary nursing (two studies), the educational toolbox (one study), the individualized care and clinical supervision (one study), and the violence prevention intervention (one study).</p> <p>Conclusions</p> <p>Little is known about the effectiveness of interventions aimed at improving the NWE, and published studies on this topic show weaknesses in their design. To advance the field, we recommend that investigators use controlled studies with pre/post measures to evaluate interventions that are aimed at improving the NWE. Thereby, more evidence-based knowledge about the implementation of interventions will become available for healthcare leaders to use in rebuilding nursing work environments.</p
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