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Disability in older adults is associated with a need for support in work, education, and community activities, reduced independence, and poorer quality of life. This study examines potential determinants of disability in a clinical sample of older adults across the continuum of cognitive decline, including sociodemographic, medical, psychiatric, and cognitive factors.
This is a cross-sectional study.
Participants were recruited from a specialty clinic for adults “at risk” of or with early dementia (including subjective cognitive complaints, mild cognitive impairment, and early dementia).
Four hundred forty-two older adults (mean age = 67.11, SD = 9.33) underwent comprehensive medical, neuropsychological, and mood assessments.
Disability was assessed via the self-report World Health Organization Disability Assessment Schedule 2.0. A stepwise (forward) linear regression model was computed to determine factors that contribute to disability within this group.
Depressive symptoms were the largest predictor, uniquely explaining 31.8% of the variance. Other contributing factors in the model included younger age, medical burden, and sleep quality, with all factors together accounting for a total of 50.4% of the variance in disability. Cognitive variables did not contribute to the model.
Depressive symptoms account for a significant portion of the variance in disability, but other factors such as age, medical burden and sleep quality are also important contributors in older adults across the continuum of cognitive decline. The relative association of these variables with disability appears to differ for older (≥65 years) relative to younger (<65 years) participants. Given the relationship between disability and these risk factors, an integrative and multidisciplinary approach to risk reduction will likely be most effective, with potential carry over effects for physical and mental health.
We determine the age of 7 stars in the Ursa Major moving group using a novel method that models the fundamental parameters of rapidly rotating A-stars based on interferometric observations and literature photometry and compares these parameters (namely, radius, luminosity, and rotation velocity) with evolution models that account for rotation. We find these stars to be coeval, thus providing an age estimate for the moving group and validating this technique. With this technique validated, we determine the age of the rapidly rotating, directly imaged planet host star, κ Andromedae.
Understanding the time-course of post-traumatic stress disorder (PTSD), and the underlying events, may help to identify those most at risk, and anticipate the number of individuals likely to be diagnosed after exposure to traumatic events.
Data from two health surveys were combined to create a cohort of 1119 Australian military personnel who deployed to the Middle East between 2000 and 2009. Changes in PTSD Checklist Civilian Version (PCL-C) scores and the reporting of stressful events between the two self-reported surveys were assessed. Logistic regression was used to examine the association between the number of stressful events reported and PTSD symptoms, and assess whether those who reported new stressful events between the two surveys, were also more likely to report older events. We also assessed, using linear regression, whether higher scores on the Kessler Psychological Distress Scale or the Alcohol Use Disorder Identification Test were associated with subsequent increases in the PCL-C in those who had experienced a stressful event, but who initially had few PTSD symptoms.
Overall, the mean PCL-C scores in the two surveys were similar, and 78% of responders stayed in the same PCL-C category. Only a small percentage moved from having few symptoms of PTSD (PCL-C < 30) in Survey 1 to meeting the criteria for PTSD (PCL-C ≥ 50) at Survey 2 (1% of all responders, 16% of those with PCL-C ≥ 50 at Survey 2). Personnel who reported more stressful lifetime events were more likely to score higher on the PCL-C. Only 51% reported the same stressful event on both surveys. People who reported events occurring between the two surveys were more likely to record events from before the first survey which they had not previously mentioned (OR 1.48, 95% CI (1.17, 1.88), p < 0.001), than those who did not. In people who initially had few PTSD symptoms, a higher level of psychological distress, was significantly associated with higher PCL-C scores a few years later.
The reporting of stressful events varied over time indicating that while the impact of some stressors endure, others may increase or decline in importance. When screening for PTSD, it is important to consider both traumatic experiences on deployment and other stressful life events, as well as other mental health problems among military personnel, even if individuals do not exhibit symptoms of PTSD on an initial assessment.
Two thiophene-based semiconductors, a vapor-deposited small molecule and an amorphous polymer, as well as pentacene for comparison, show potential in enhancing the thermoelectric properties of tellurium (Te) nanowires. For vapor-deposited films, Te nanostructures form directly on glass substrates or organic semiconductor films. The resulting Te power factor (S2σ) was enhanced from 36 to 45 W/mK2 (56 for pentacene) because the bilayer provides an enhancement in Seebeck (S) without compromising conductivity (σ). For solution deposited polymer blends, we obtained power factors from a Te nanowire network that alone would not have sufficient connectivity (up to 0.1 µW/mK2). While the organics are unoptimized, they are prototypical materials for further development.
New angular diameter determinations for the bright southern F8 supergiant δ CMa enable the bolometric emergent flux and effective temperature of the star to be determined with improved accuracy. The spectral flux distribution and bolometric flux have been determined from published photometry and spectrophotometry and combined with the angular diameter to derive the bolometric emergent flux ℱ = (6.50 ± 0.24) × 107 Wm−2 and the effective temperature Teff = 5818 ± 53 K. The new value for the effective temperature is compared with previous interferometric and infrared flux method determinations. The accuracy of the effective temperature is now limited by the uncertainty in the bolometric flux rather than by the uncertainty in the angular diameter.
A new beam-combination and detection system has been installed in the Sydney University Stellar Interferometer working at the red end of the visual spectrum (λλ 500–950 nm) to complement the existing blue-sensitive system (λλ 430–520 nm) and to provide an increase in sensitivity. Dichroic beam-splitters have been introduced to allow simultaneous observations with both spectral systems, albeit with some restriction on the spectral range of the longer wavelength system (λλ 550–760 nm). The blue system has been upgraded to allow remote selection of wavelength and spectral bandpass, and to enable simultaneous operation with the red system with the latter providing fringe-envelope tracking. The new system and upgrades are described and examples of commissioning tests presented. As an illustration of the improvement in performance the measurement of the angular diameter of the southern F supergiant δ CMa is described and compared with previous determinations.
The Sydney University Stellar Interferometer (SUSI) has been used to make a new determination of the angular diameter of Sirius A. The observations were made at an effective wavelength of 694.1 nm and the new value for the limb-darkened angular diameter is 6.048 ± 0.040 mas (± 0.66%). This new result is compared with previous measurements and is found to be in excellent agreement with a conventionally calibrated measurement made with the European Southern Observatory's Very Large Telescope Interferometer (VLTI) at 2.176 μm (but not with a second globally calibrated VLTI measurement). A weighted mean of the SUSI and first VLTI results gives the limb-darkened angular diameter of Sirius A as 6.041 ± 0.017 mas (± 0.28%). Combination with the Hipparcos parallax gives the radius equal to 1.713 ± 0.009 R⊙. The bolometric flux has been determined from published photometry and spectrophotometry and, combined with the angular diameter, yields the emergent flux at the stellar surface equal to (5.32 ± 0.14) × 108 W m−2 and the effective temperature equal to 9845 ± 64 K. The luminosity is 24.7 ± 0.7 L⊙.
Electroluminescent zinc sulfide doped with copper and chloride (ZnS:Cu, Cl) powder was heated to 400°C and rapidly quenched to room temperature. Comparison between the quenched and non-quenched phosphors using synchrotron radiation X-ray powder diffraction (XRPD) (λ = 0.828692 Å) and X-ray absorption spectroscopy (XAS) was made. XRPD shows that the expected highly faulted structure is observed with excellent resolution out to 150° 2θ (or to (12 2 2) of the sphalerite phase). The quenched sample compared to the unheated sample shows a large change in peak ratios between 46.7° and 46.9°, which is thought to correspond to the wurtzite (0 0 6), (0 3 2) and sphalerite (3 3 3)/(5 1 1) peaks. Hence, a large proportion of this sphalerite diffraction is lost from the material upon rapid quenching, but not when the material is allowed to cool slowly. The Zn K-edge XAS data indicate that the crystalline structures are indistinguishable using this technique, but do give an indication that the electronic structure has altered due to changing intensity of the white line. It is noted that the blue electroluminescence (EL) emission bands are lost upon quenching: however, a large amount of total EL emission intensity is also removed, which is consistent with our findings. We report the XRPD of a working alternating-current electroluminescence device in the synchrotron X-ray beam, which exhibits a new diffraction pattern when the device is powered in an AC field even though the phosphor is fixed in the binder. Significantly, only a few crystals are required to yield the diffraction data because of the high flux X-ray source. These in panel data show multiple sharp diffraction lines spread out under the region, where capillary data show broad diffraction intensity indicating that the phosphor powder is comprised of unique crystals, each having different structures.
Research on skill acquisition and retention in the prehospital setting has focused primarily on resuscitation and defibrillation. Investigation into other first aid skills is required in order to validate practices and support training regimes. No studies have investigated competency using an extrication cervical collar for cervical spine immobilization.
This study was conducted to confirm that a group of first responders could acquire and maintain competency in the application of an extrication cervical collar over a 12-month period.
Participants attended a standardized training session that addressed the theory of application of an extrication cervical collar followed by hands-on practice. The training was presented by the same instructor and covered the nine key elements necessary in order to be deemed competent in extraction cervical collar application. Following the practical session, the competency of the participants was assessed. Participants were requested not to practice the skill during the 12-month period. Following the 12-month period, their skills were re-assessed by the same assessor.
Of the 64 subjects who participated in the study, 100% were competent after the initial first assessment. Forty-one participants (64%) were available for the second assessment (12 months later); of these, 25 (61%) maintained competence.
Although the sample size was small, this research demonstrates that first responders are able to acquire competence in applying an extrication cervical collar. However, skill retention in the absence of usage or re-training is poor. Larger studies should be conducted to validate these results. In addition, there is a need for research on the clinical practice and outcomes associated with spinal immobilization in the prehospital setting.
Magneto-hydrodynamic wave modes propagating from the solar photosphere into the corona have the potential to be exploited as an observational tool in an analogous way to the use of acoustic waves in helio/terrestrial seismology. In regions of strong magnetic field photospheric p-modes are thought to undergo mode conversion to slow magneto-acoustic waves, and that these slow magnetoacoustic p-modes may be waveguided from the photosphere into the solar corona along the magnetic field. A Bayesian analysis technique is applied to observations which suggests four distinct p-modes may be resolved in the transition region.
In 2005 we obtained very precise interferometric measurements of the pole-on rapid rotator Vega (A0 V) with the longest baselines of the Center for High Angular Angular Resolution (CHARA) Array and the Fiber Linked Unit for Optical Recombination (FLUOR). For the analysis of these data, we developed a code for mapping sophisticated PHOENIX model atmospheres on to the surface of rotationally distorted stars described by a Roche-von Zeipel formalism. Given a set of input parameters for a star or binary pair, this code predicts the interferometric visibility, spectral energy distribution and high-resolution line spectrum expected for the system. For the gravity-darkened Vega, our model provides a very good match to the K-band interferometric data, a good match to the spectral energy distribution – except below 160 nm – and a rather poor match to weak lines in the high dispersion spectrum where the model appears overly gravity darkened. In 2006, we used the CHARA Array and FLUOR to obtain high precision measurements of the massive, non-eclipsing, double-line spectroscopic binary Spica, a 4-day period system where both components are gravity darkened rapid rotators. These data supplement recent data obtained with the Sydney University Stellar Interferometer (SUSI). Our study follows the classic 1971 study by Herbison-Evans et al. who resolved Spica as a binary with the Narrabri Stellar Intensity Interferometer (NSII). We will report on our progress modeling the new interferometric and archival spectroscopic data, with the goal towards better constraining the apsidal constant.
Solid solution series of the type K2Bi8-xSbxSe13, K2-xRbxBi8Se13 as well as K2Bi8Se13-xSx were prepared and the distribution of the atoms (Bi/Sb, K/Rb and Se/S) on different crystallographic sites, the band gaps and their thermoelectric properties were studied. The distribution Se/S appears to be more uniform than the distribution of the Sb and Rb atoms in the β-K2Bi8Se13 structure that shows preference in specific sites in the lattice. Band gap is mainly affected by Sb and S substitution. Seebeck coefficient measurements showed n-type character for of all Se/S members. In the Bi/Sb series an enhancement of p-type character was observed. The thermoelectric performance as well as preliminary high temperature measurements suggest the potential of these materials for high temperature applications.
To audit the clinical practice of seizure threshold estimation and subsequent stimulus dose adjustment in the electroconvulsive therapy (ECT) clinic. Case notes of patients who had ECT over a six-month period were audited. Results were discussed at an audit meeting and guidelines and training modified appropriately prior to the second cycle of the audit.
Initial dose titration was poor in the first period, but improved in the second. The majority of patients were insufficiently stimulated after missed seizures in both periods and stimulus doses were not being reduced following prolonged seizures.
The audit identified the need for continuing supervision of trainees in addition to clear training and guidelines.
The retinal vasculature of postmortem normal human and diabetic
eyes was studied using an
immunohistochemical technique in conjunction with confocal laser scanning
microscopy. The technique,
which stained for von Willebrand factor, allowed both large areas of the
retinal vasculature to be visualised
and abnormalities to be studied in detail without disturbing the tissue
architecture. Only one
microaneurysm, defined as any focal capillary dilation, was observed in
10 normal eyes but numerous
microaneurysms were seen in 4 out of 5 diabetic retinas; counts varied
between 0 and 26 per 0.41 mm2
sample area. Microaneurysms were classified into 3 categories according
to morphology: saccular, fusiform
and focal bulges. Most were saccular, these having no preferred orientation.
The majority of
microaneurysms were associated with just 2 vessels suggesting they were
unlikely to develop at vascular
junctions. The majority were observed to originate from the inner nuclear
layer and were therefore in the
deeper part of the inner retinal capillary plexus. Variation in the staining
of microaneurysms may correlate
with endothelial dysfunction seen clinically as dye leakage during fluorescein