529 research outputs found
Intraindividual Variability in Cortisol: Approaches, Illustrations, and Recommendations
Most of the variance in diurnal cortisol is attributable to intraindividual variability (IIV), defined as relatively short-term, reversible changes. Multiple methods for measuring IIV have been proposed, and some have already been applied to cortisol IIV. In the present review, measurement methods are described and applied to simulated cortisol data with known underlying differences in IIV and to real cortisol data from first-year law students. More slope variance and more residual or net variance were well captured by their individual standard deviations. Explorations of reliability suggested that 10 slopes and 50 residuals result in reliable and stable estimates of the individual standard deviations. A data-analytic plan for cortisol IIV is provided
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Feasibility of incorporating objective measures of physical activity in the STEPS program. A pilot study in Malawi
Background
Physical activity is an important determinant of human health but it is inherently difficult to measure. Global surveillance systems for physical activity have so far only included self-report measures, which capture only a small subset of daily activity and are limited due to issues of recall bias. Wrist-worn accelerometry offers a reasonably cost-effective objective method of measuring physical activity during free-living with proven feasibility in large-scale population studies.
The key objective of this project was to pilot wrist-worn accelerometry within a surveillance setting in order to inform the implementation of this methodology into the global WHO STEPS programme.
Method development and implementation
Accelerometry protocols were developed and deployed within an existing STEPS survey in two regions of Malawi (Dowa and Lilongwe). This also included developing training for local staff. Survey information was collected on tablets. Accelerometers could only be set up on PCs, so the protocol was adapted to do this in advance of recruiting participants. For this, an alternative Participant ID linkage system was developed to enable linking accelerometer files to the rest of the survey data.
On the whole, the implementation was successful. During the process evaluation, some issues were identified. For example, black wrist straps were culturally associated with the Devil by some participants. A total of 499 participants were recruited for Step 1 and 2, of whom 446 returned for Step 3 measurements which included accelerometry.
The accelerometry data collection was well accepted by both fieldwork team members and study participants, with only four participants (<1% of those eligible) declining to wear the device. There were no major technical issues with devices, although a small number of wrist straps were damaged and 13 monitors were lost (3% of deployed). Of 456 accelerometer files retrieved, 410 files (90%) could be linked to survey participants.
All but two accelerometer files could be processed with standard techniques to produce participant-level summary results. Sufficient valid data (defined as at least 48 hours of monitor wear time with reasonable diurnal representation) were available for 386 survey participants (87% of eligible).
Results
Objective levels of physical activity in Malawi from this pilot study were about 50% higher than levels observed in the UK using similar methodology. Rural dwellers were more active than urban dwellers, particularly in the morning hours of the day. Men had higher activity levels compared to women, and there were decreasing trends with advancing age.
Conclusion and recommendations
This pilot demonstrated that it is feasible to implement wrist-worn accelerometry within the STEPS program in settings such as Malawi. Detailed description of objectively measured physical activity patterns could be produced from nearly all accelerometer files retrieved, including behavioural indicators known to be important for human health.
In future surveys, culturally specific issues that could impact data collection should be identified early in the fieldwork planning stage and changes to the protocol made. Experiences from this pilot have led to development of software platforms that allow accelerometers to be set up from Android tablets at the point of issuing the device to the participant, which would simplify future fieldwork training and reduce risk of data linkage error
Socioemotional Selectivity and Psychological Health in Amyotrophic Lateral Sclerosis Patients and Caregivers: A Longitudinal, Dyadic Analysis
Objective: Socioemotional selectivity theory predicts that as the end of life approaches, goals and resources that provide immediate, hedonic reward become more important than those that provide delayed rewards. This study tested whether these goal domains differentially affected psychological health in the context of marital dyads in which one partner had been diagnosed with amyotrophic lateral sclerosis (ALS), a life-limiting disease.
Design: ALS patients (N = 102) being treated in three multidisciplinary clinics and their spouses (N = 100) reported their loneliness, financial worry and psychological health every 3 months for up to 18 months.
Main Outcome Measure: Psychological health composite.
Results: In multilevel dyadic models, patients and spouses had similar levels of financial worry and loneliness. Both patients and spouses had worse psychological health with higher loneliness, but only spouses had worse psychological health with higher financial worry. Significant interactions with age and disease severity indicated that older spouses were more affected by loneliness than were younger spouses, and patients with less severe disease were more affected by financial worry than patients with more severe disease.
Conclusion: The results provide good support for socioemotional selectivity theory’s implications for psychological health in a strong test of the theory
Spatiotemporal effects of logging and fire on tall, wet temperate eucalypt forest birds
Forests globally are subject to disturbances such as logging and fire that create complex temporal variation in spatial patterns of forest cover and stand age. However, investigations that quantify temporal changes in biodiversity in response to multiple forms of disturbance in space and time are relatively uncommon. Over a 10-yr period, we investigated the response of bird species to spatiotemporal changes in forest cover associated with logging and wildfire in the mountain ash (Eucalyptus regnans) forests of southeastern Australia. Specifically, we examined how bird occurrence changed with shifts in the proportion of area burned or logged in a 4.5 km radius surrounding our 88 long-term field survey sites, each measuring 1 ha in size. Overall species richness was greatest in older forest patches, but declined as the amount of fire around each site increased. At the individual species level, 31 of the 37 bird species we modeled exhibited a negative response to the amount of fire in the surrounding landscape, while one species responded positively to fire. Only nine species exhibited signs of recovery in the 6 yr of surveys following the fire. Five species were more likely to be detected as the proportion of logged forest surrounding a site increased, suggesting a possible "concentration effect" with displaced birds moving into unlogged areas following harvesting of adjacent areas. We also identified relationships between the coefficients of life history attributes and spatiotemporal changes in forest cover and stand age. Large-bodied birds and migratory species were associated with landscapes subject to large amounts of fire in 2009. There were associations between old growth stands and small-bodied bird species and species that were not insectivores. Our study shows that birds in mountain ash forests are strongly associated with old growth stands and exhibit complex, time-dependent, and species-specific responses to landscape disturbance. Despite logging and fire both being high-severity perturbations, no bird species exhibited similar responses to fire and logging in the landscape surrounding our sites. Thus, species responses to one kind of landscape-scale disturbance are not readily predictable based on an understanding of the responses to another kind of (albeit superficially similar) disturbance.Threatened Species Recovery Hub of the National Environmental Science Program, Parks Victoria, and Victorian Government Department of Environment, Land, Water and Plannin
Flower numbers, pod production, pollen viability, and pistil function are reduced and flower and pod abortion increased in chickpea (Cicer arietinum L.) under terminal drought
Terminal drought during the reproductive stage is a major constraint to yield of chickpea in many regions of the world. Termination of watering (WS) during podding in a small-seeded desi chickpea (Cicer arietinum L.) cultivar, Rupali, and a large-seeded kabuli chickpea cultivar, Almaz, induced a decrease in predawn leaf water potential (LWP), in the rate of photosynthesis, and in stomatal conductance. Compared to well-watered (WW) controls, the WS treatment reduced flower production by about two-thirds. In the WW treatment, about 15% of the flowers aborted and 42% (Rupali) and 67% (Almaz) of the pods aborted, whereas in the WS treatment 37% and 56% of the flowers aborted and 54% and 73% of the pods aborted, resulting in seed yields of 33% and 15% of the yields in WW plants in Rupali and Almaz, respectively. In vitro pollen viability and germination in Rupali decreased by 50% and 89% in the WS treatment, and pollen germination decreased by 80% in vivo when pollen from a WS plant was placed on a stigma of a WW plant. While about 37% of the germinated pollen tubes from WW plants and 22% from the WS plants reached the ovary in the WW plants, less than 3% of pollen grains reached the ovary when pollen from either WS or WW plants was placed on a stigma of a WS plant. It is concluded that, in addition to pod abortion, flower abortion is an important factor limiting yield in chickpea exposed to terminal drought and that water deficit impaired the function of the pistil/style more than the pollen
Impact of Motor Therapy with Dynamic Body-Weight Support on Functional Independence Measures in Traumatic Brain Injury: An Exploratory Study
BACKGROUND: Contemporary goals of rehabilitation after traumatic brain injury (TBI) aim to improve cognitive and motor function by applying concepts of neuroplasticity. This can be challenging to carry out in TBI patients with motor, balance, and cognitive impairments.
OBJECTIVE: To determine whether use of dynamic body-weight support (DBWS) would allow safe administration of intensive motor therapy during inpatient rehabilitation and whether its use would yield greater improvement in functional recovery than standard-of-care (SOC) therapy in adults with TBI.
METHODS: Data in this retrospective cohort study was collected from patients with TBI who receive inpatient rehabilitation incorporating DBWS (n = 6) and who received inpatient rehabilitation without DBWS (SOC, n = 6). The primary outcome measure was the change in Functional Independence Measures (FIM) scores from admission to discharge.
RESULTS: There was significant improvement in total FIM scores at discharge compared to admission for both the DBWS (p = 0.001) and SOC (p = 0.005) groups. Overall, the DBWS group had greater improvement in total FIM score and FIM subscales compared to the SOC group.
CONCLUSIONS: Our results suggest DBWS has the potential to allow a greater intensity of therapy during inpatient rehabilitation and yield better outcomes compared to SOC in patients with TBI
Tests on models of condenser scoops
Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Naval Architecture and Marine Engineering, 1937.MIT copy bound with: A more efficient yacht racing rig / Frank Jewett Mather, III.Includes bibliographical references (leaf 41).by R. B. Westgate, S. C. Powell.B.S
Free versus total serum 25-hydroxyvitamin D in a murine model of colitis
Inflammatory bowel diseases (IBD) such as ulcerative colitis and Crohn's disease have been linked to vitamin D-deficiency. Using a dextran sodium sulphate (DSS)-induced model of IBD we have shown previously that mice raised on vitamin D-deficient diets from weaning have lower serum 25-hydroxyvitamin D (25OHD) levels and develop more severe colitis compared to vitamin D-sufficient counterparts. We have also shown in vitro that immune responses to 25OHD may depend on 'free' rather than total serum concentrations of 25OHD. To investigate the possible effects of free versus total 25OHD on anti-inflammatory immune responses in vivo we have studied DSS-induced colitis in wild type C57BL/6 mice raised from weaning on diets containing vitamin D2 (D2) or vitamin D3 (D3) only (both 1000 IU/kg feed). 25OHD2 has lower binding affinity for the vitamin D binding protein than 25OHD3 which results in higher levels of free 25OHD2 relative to free 25OHD3 in mice raised on a D2-only diet. Total serum 25OHD concentrations, measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS), showed that D2 mice had significantly lower levels of 25OHD than D3 mice (6.85 ± 2.61 nmol/L vs. 49.16 ± 13.8 nmol/L for D2 and D3 respectively). Despite this, direct ELISA measurement showed no difference in free serum 25OHD levels between D2 and D3 mice (13.62 ± 2.26 pmol/L vs. 14.11 ± 2.24 pmol/L for D2 and D3 respectively). Analysis of DSS-induced colitis also showed no difference in weight loss or disease progression between D2 and D3 mice. These data indicate that despite D2-fed mice being vitamin D-deficient based on serum total 25OHD concentrations, these mice showed no evidence of increased inflammatory colitis disease relative to vitamin D-sufficient D3 mice. We therefore propose that free, rather than total serum 25OHD, may be a better marker of immune responses to vitamin D in vivo
Applicability of a Markov-chain Monte Carlo method for damage detection on data from the Z-24 and Tamar suspension bridges
In the Structural Health Monitoring of bridges, the effects of the operational and environmental variability on the structural responses have posed several challenges for early damage detection. In order to overcome those challenges, in the last decade recourse has been made to the statistical pattern recognition paradigm based on vibration data from long-term monitoring. The use of purely data-based algorithms that do not depend on the physical descriptions of the structures have characterized this paradigm. However, one drawback of this procedure is how to set up the baseline condition for new and existing bridges. Therefore, this paper proposes an algorithm with a Bayesian approach based on a Markov-chain Monte Carlo method to cluster structural responses of the bridges into a reduced number of global state conditions, by taking into account eventual multimodality and heterogeneity of the data distribution. This approach, along with the Mahalanobis squared-distance, permits one to form an algorithm able to detect structural damage based on daily response data even under abnormal events caused by operational and environmental variability. The applicability of this approach is first demonstrated on standard data sets from the Z-24 Bridge, Switzerland. Afterwards, for generalization purposes, it is applied on datasets from a supposed undamaged bridge condition, namely the Tamar Bridge, England. The analysis suggests that this algorithm might be useful for bridge applications, because it permits one to overcome some of the limitations posed by the pattern recognition paradigm, especially when dealing with limited amounts of training data.info:eu-repo/semantics/publishedVersio
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