1,018 research outputs found
Langley's CSI evolutionary model: Phase O
A testbed for the development of Controls Structures Interaction (CSI) technology to improve space science platform pointing is described. The evolutionary nature of the testbed will permit the study of global line-of-sight pointing in phases 0 and 1, whereas, multipayload pointing systems will be studied beginning with phase 2. The design, capabilities, and typical dynamic behavior of the phase 0 version of the CSI evolutionary model (CEM) is documented for investigator both internal and external to NASA. The model description includes line-of-sight pointing measurement, testbed structure, actuators, sensors, and real time computers, as well as finite element and state space models of major components
Frailty index transitions over eight years were frequent in The Irish Longitudinal Study on Ageing.
Background: The frailty index (FI) is based on accumulation of health deficits. FI cut-offs define non-frail, prefrail and frail states. We described transitions of FI states in The Irish Longitudinal Study on Ageing (TILDA). Methods: Participants aged ≥50 years with information for a 31-deficit FI at wave 1 (2010) were followed-up over four waves (2012, 2014, 2016, 2018). Transitions were visualized with alluvial plots and probabilities estimated with multi-state Markov models, investigating the effects of age, sex and education. Results: 8174 wave 1 participants were included (3744 men and 4430 women; mean age 63.8 years). Probabilities from non-frail to prefrail, and non-frail to frail were 18% and 2%, respectively. Prefrail had a 19% probability of reversal to non-frail, and a 15% risk of progression to frail. Frail had a 21% probability of reversal to prefrail and 14% risk of death. Being older and female increased the risk of adverse FI state transitions, but being female reduced the risk of transition from frail to death. Higher level of education was associated with improvement from prefrail to non-frail. Conclusions: FI states are characterized by dynamic longitudinal transitions and frequent improvement. Opportunities exist for reducing the probability of adverse transitions
Роль корпоративной культуры в системе мотивации труда
OBJECTIVES: Multimorbidity is common in the older population, but the impact of combinations of chronic conditions on disability and quality of life (QoL) is not well known. This analysis explores the effect of specific combinations of chronic diseases on disability, QoL and self-rated health (SRH). DESIGN: We used data from two population representative cross-sectional studies, the Northern Ireland Health and Social Wellbeing Survey (NIHSWS) 2005 and the Survey of Lifestyle, Attitudes and Nutrition (SLAN) 2007 (conducted in the Republic of Ireland). SETTING: Randomly selected community-living participants were interviewed at home. PARTICIPANTS: A total of 6159 participants aged 50 years and older were included in the analysis. OUTCOME MEASURES: Chronic conditions were classified as cardiovascular disease, chronic pain, diabetes or respiratory disease. Interaction terms estimated by logistic regression were used to examine the effects of multiple chronic conditions on disability, SRH and QoL. RESULTS: Each chronic condition group was correlated with each of the others after adjusting for sociodemographic factors. Those from Northern Ireland were more likely to report a limitation in daily activities (45%) compared to those from the Republic of Ireland (21%). Each condition had an independent effect on disability, SRH and QoL, and those with multiple chronic conditions reported the worst outcomes. However, there were no statistically significant positive interactions between chronic condition groups with respect to any outcome. CONCLUSIONS: Chronic conditions affect individuals largely independent of each other with respect to their effect on disability, SRH and QoL. However, a significant proportion of the population aged 50 years and over across the island of Ireland lives with multimorbidity, and this group is at the highest risk of disability, poor SRH and poor QoL
Impaired Orthostatic Blood Pressure Recovery is associated with Unexplained and Injurious Falls
Background/Objectives: Cardiovascular disorders are recognised as important modifiable risk factors for falls. However the association between falls and orthostatic hypotension (OH) remains ambivalent, particularly because of poor measurement methods of previous studies. Our goal was to determine for the first time to what extent OH (and variants) are risk factors for incident falls, unexplained falls (UF), injurious falls (IF) and syncope using dynamic blood pressure (BP) measurements in a population study. Design: Nationally Representative Longitudinal Cohort Study - The Irish Longitudinal Study on Ageing (TILDA) – wave 1 (2009-2011) with 2 year follow-up at wave 2 (2012-2013). Setting: Community dwelling adults. Participants: 4127 participants were randomly sampled from the population of older adults aged ≥50 years resident in Ireland. Measurements: Continuous BP recordings measured during active stands were analysed. OH and variants (initial OH and impaired orthostatic BP stabilisation OH(40)) were defined using dynamic BP measurements. Associations with the number of falls, UF, IF and syncope reported two years later were assessed using negative binomial and modified Poisson regression. Results: Participants had a mean age 61.5(8.2) years (54.2% female). OH(40) was associated with increased relative risk of UF (RR:1.52 95%CI:1.03-2.26). OH was associated with all-cause falls (IRR:1.40 95%CI:1.01-1.96), UF(RR:1.81 95%CI:1.06-3.09), and IF(RR:1.58 95%CI:1.12-2.24). IOH was not associated with any outcome. Conclusion: With the exception of initial orthostatic hypotension, beat-to-beat measures of impaired orthostatic BP recovery (delayed or incomplete stabilisation) are independent risk factors for future falls, unexplained falls, and injurious falls
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Informing patterns of health and social care utilisation in Irish older people according to the Clinical Frailty Scale.
Background: There is increasing policy interest in the consideration of frailty measures (rather than chronological age alone) to inform more equitable allocation of health and social care resources. In this study the Clinical Frailty Scale (CFS) classification tree was applied to data from The Irish Longitudinal Study on Ageing (TILDA) and correlated with health and social care utilisation. CFS transitions over time were also explored. Methods: Applying the CFS classification tree algorithm, secondary analyses of TILDA data were performed to examine distributions of health and social care by CFS categories using descriptive statistics weighted to the population of Ireland aged ≥65 years at Wave 5 (n=3,441; mean age 74.5 (SD ±7.0) years, 54.7% female). CFS transitions over 8 years and (Waves 1-5) were investigated using multi-state Markov models and alluvial charts. Results: The prevalence of CFS categories at Wave 5 were: 6% 'very fit', 36% 'fit', 31% 'managing well', 16% 'vulnerable', 6% 'mildly frail', 4% 'moderately frail' and 1% 'severely frail'. No participants were 'very severely frail' or 'terminally ill'. Increasing CFS categories were associated with increasing hospital and community health services use and increasing hours of formal and informal social care provision. The transitions analyses suggested CFS transitions are dynamic, with 2-year probability of transitioning from 'fit' (CFS1-3) to 'vulnerable' (CFS4), and 'fit' to 'frail' (CFS5+) at 34% and 6%, respectively. 'Vulnerable' and 'frail' had a 22% and 17% probability of reversal to 'fit' and 'vulnerable', respectively. Conclusions: Our results suggest that the CFS classification tree stratified the TILDA population aged ≥65 years into subgroups with increasing health and social care needs. The CFS could be used to aid the allocation of health and social care resources in older people in Ireland. We recommend that CFS status in individuals is reviewed at least every 2 years
Mini-mast CSI testbed user's guide
The Mini-Mast testbed is a 20 m generic truss highly representative of future deployable trusses for space applications. It is fully instrumented for system identification and active vibrations control experiments and is used as a ground testbed at NASA-Langley. The facility has actuators and feedback sensors linked via fiber optic cables to the Advanced Real Time Simulation (ARTS) system, where user defined control laws are incorporated into generic controls software. The object of the facility is to conduct comprehensive active vibration control experiments on a dynamically realistic large space structure. A primary goal is to understand the practical effects of simplifying theoretical assumptions. This User's Guide describes the hardware and its primary components, the dynamic characteristics of the test article, the control law implementation process, and the necessary safeguards employed to protect the test article. Suggestions for a strawman controls experiment are also included
A higher degree of resilience: Using psychometric testing to reveal the benefits of university internship placements
Resilience is a multi-faceted concept but, in the context of learning, it can best be thought of as an individual’s capacity to create and maximise opportunities as well as responding positively to setbacks and challenges. Developing students’ resilience is becoming increasingly important. Research has shown resilience links to attainment, retention, engagement and employability. However, very little work has examined what aspects of curricula enhance resilience and the particular role of active learning frameworks in achieving this. Here, we analyse the effects of optional real-world internship placements on eight measures of resilience. Psychometric testing was conducted twice per student – at the start of their second academic year and again at the end. Students choosing an internship had significantly higher challenge orientation and adaptability scores than other students in the same cohort. Adaptability of both interns and non-interns improved over the academic year, but improvement was significantly higher for interns. Scores for optimism, purposeful direction, and ingenuity significantly increased between start-of-year and end-of-year tests for interns versus a decline for non-interns. We conclude that facilitating student engagement with real-world issues and challenges through supported internships within an active learning framework is an important mechanism for increasing students’ resilience
Sedative load and frailty among community-dwelling population aged ≥65 years
OBJECTIVE: To explore the association between use of sedative drugs and frailty. DESIGN: Cross-sectional study. SETTING: First wave of The Irish Longitudinal Study on Ageing (TILDA), a nationally representative cohort of the community-dwelling population aged 50 years or older in Ireland. PARTICIPANTS: Participants were 1642 men and 1804 women aged 65 years or older. MEASUREMENTS: Regular use of sedative drugs determined according to the sedative load (SL) model, frailty phenotype status, and frailty deficit index (FI) score assessed using validated, established protocols. RESULTS: Overall, 19% of the participants took sedative drugs, most frequently hypnotics and antidepressants. Sedative drug use was at 46% for frail, 23% for prefrail, and 9% for nonfrail participants. After adjustment for covariates, SL was positively associated with being prefrail (odds ratio [OR] 1.27; 95% confidence interval [CI] 1.11-1.46) and frail (OR 1.30; 95% CI 1.02-1.64). Advancing age but not sex remained significant (P < .001). After adjustment for covariates, the association between SL and the FI was also significant at P ≤ .001 (β = 1.77; 95% CI 1.13-2.42). CONCLUSION: Higher SL was positively associated with phenotype frailty and the FI. This suggests that careful consideration must be given when prescribing sedatives to frail older adults, who are most vulnerable to adverse drug reactions and adverse health outcomes
Genetic Determinants of Amidating Enzyme Activity and its Relationship with Metal Cofactors in Human Serum
Abstract BACKGROUND:
α-amidation is a final, essential step in the biosynthesis of about half of all peptide hormones and neurotransmitters. Peptidylglycine α-amidating monooxygenase (PAM), with enzymatic domains that utilize Cu and Zn, is the only enzyme that catalyzes this reaction. PAM activity is detected in serum, but its significance and utility as a clinical biomarker remain unexplored. METHODS:
We used well-established enzymatic assays specific for the peptidylglycine-α -hydroxylating monooxygenase (PHM) and peptidyl-α-hydroxyglycine α-amidating lyase (PAL) domains of PAM to quantify amidating activity in the sera of 144 elderly men. Relationships between PHM and PAL activity and serum levels of their respective active-site metals, Cu and Zn, were analyzed. Study participants were also genotyped for eight non-coding single nucleotide polymorphisms (SNPs) in PAM, and relationships between genotype and serum enzyme activity and metal levels were analyzed. RESULTS:
Serum PHM and PAL activities were normally distributed and correlated linearly with each other. Serum PAL activity, but not serum PHM activity, correlated with serum Cu; neither activity correlated with serum Zn. Study subjects possessing the minor alleles for rs32680 had lower PHM and PAL activities, and subjects with minor alleles for rs11952361 and rs10515341 had lower PHM activities. CONCLUSIONS:
Our results characterize large variation in serum amidating activity and provide unique insight into its potential origin and determinants. Common non-coding polymorphisms affect serum amidating activity and Cu levels. Serum amidating activity should be explored as a biomarker for functionality in the elderly and in additional study groups
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