1,323 research outputs found
Depressive symptoms and quality of life in people with age-related macular degeneration
Purpose: To examine quality of life and associated factors in people with Age-Related Macular Degeneration (AMD). Methods: One hundred and forty-five AMD participants (mean age 78.0 +/- 7.7 years) and 104 age- and gender- matched controls (mean age 78.1 +/- 5.8 years) comprised the study populations for this case-control study. Depressive symptoms were measured with the Goldberg Anxiety and Depression (GAD) scale; general health and daily functioning was assessed with the Medical Outcomes Study Short Form 36 (SF-36) and questions relating to assistance required for daily living activities. Results: People with AMD performed more poorly than controls on the GAD depression scale, and physical functioning subscale of SF-36. 44.4% of people with AMD had clinically significant depressive symptoms compared to 17.5% of controls (p < 0.001). Multiple regression analysis revealed that AMD was independently associated with depressive symptoms and a path model indicated that AMD led to depressive symptoms both directly and indirectly via reduced general health and social functioning. Conclusion: Psychological and functional outcome measures are reduced in people with AMD. Earlier recognition and treatment of depressive symptoms in people with AMD may be crucial to maintaining quality of life in this group
The role of concern about falling on stepping performance during complex activities
Background There is limited understanding of the underlying mechanisms explaining the role of concern about falling on fall risk in older people. Anxiety is known to interact with cognitive resources and, as people get older, they require more cognitive resources to maintain balance. This might affect an individual's ability to perform cognitive-motor tasks concurrently. The aim of this study was to investigate the effect of a visuospatial dual-task on stepping performance in older people with and without concern about falling and the impact of repeating this task in those with high concern about falling. Methods Three-hundred-eight community-dwelling older people, aged 70 to 90 years old, participated in the study. Participants were asked to perform a Choice Stepping Reaction Time (CSRT) task in two conditions; once without any other tasks (single task condition), and once while simultaneously performing a visuospatial task (dual-task condition). Participants were asked to rate their levels of concern and confidence specifically related to each of the 25 stepping trials (before/after). We also measured general concern about falling, affect, and sensorimotor and cognitive functioning. Results Total stepping reaction times increased when participants also performed the visuospatial task. The relation between general concern about falling and stepping reaction time, was affected by sensorimotor and executive functioning. Generalised linear mixed models showed that the group with moderate to high levels of general concern about falling had slower total stepping reaction times than those with lower levels of concern about falling, especially during the dual-task condition. Individuals with greater general concern about falling showed reduced confidence levels about whether they could do the stepping tasks under both conditions. Repeatedly performing the stepping task reduced the immediate task-specific concern about falling levels and increased confidence in all participants. Conclusions These findings reveal that people with higher general concern about falling experienced more difficulties during a dual-task condition than people with lower levels of concern. Of further interest, better sensorimotor and cognitive functioning reduced this effect. Graded exposure has potential to reduce concern about falling during fear-evoking activities, especially in conjunction with therapies that improve balance, mood and cognitive function
The falls efficacy scale international (FES-I): a comprehensive longitudinal validation study
Method: five hundred community-dwelling older people (70-90 years) were assessed on the FES-I in conjunction with demographic, physiological and neuropsychological measures at baseline and at 12 months. Falls were monitored monthly and fear of falling every 3 months.
Results: the overall structure and measurement properties of both FES-I scales, as evaluated with item response theory, were good. Discriminative ability on physiological and neuropsychological measures indicated excellent validity, both at baseline (n = 500, convergent validity) and at 1-year follow-up (n = 463, predictive validity). The longitudinal follow-up suggested that FES-I scores increased over time regardless of any fall event, with a trend for a stronger increase in FES-I scores when a person suffered multiple falls in a 3-month period. Additionally, using receiver-operating characteristic (ROC) curves, cut-points were defined to differentiate between lower and higher levels of concern.
Conclusions: the current study builds on the previously established psychometric properties of the FES-I. Both scales have acceptable structures, good validity and reliability and can be recommended for research and clinical purposes. Future studies should explore the FES-I's responsiveness to change during intervention studies and confirm suggested cut-points in other settings, larger samples and across different cultures
A multifactorial approach for understanding fall risk in older people
OBJECTIVE: To identify the interrelationships and discriminatory value of a broad range of objectively measured explanatory risk factors for falls.
DESIGN: Prospective cohort study with 12-month follow-up period.
SETTING: Community sample.
PARTICIPANTS: Five hundred community-dwelling people aged 70 to 90.
MEASUREMENTS: All participants underwent assessments on medical, disability, physical, cognitive, and psychological measures. Fallers were defined as people who had at least one injurious fall or at least two noninjurious falls during a 12-month follow-up period.
RESULTS: Univariate regression analyses identified the following fall risk factors: disability, poor performance on physical tests, depressive symptoms, poor executive function, concern about falling, and previous falls. Classification and regression tree analysis revealed that balance-related impairments were critical predictors of falls. In those with good balance, disability and exercise levels influenced future fall risk-people in the lowest and the highest exercise tertiles were at greater risk. In those with impaired balance, different risk factors predicted greater fall risk-poor executive function, poor dynamic balance, and low exercise levels. Absolute risks for falls ranged from 11% in those with no risk factors to 54% in the highest-risk group.
CONCLUSIONS: A classification and regression tree approach highlighted interrelationships and discriminatory value of important explanatory fall risk factors. The information may prove useful in clinical settings to assist in tailoring interventions to maximize the potential benefit of falls prevention strategies
L-citrulline supplementation improves O2 uptake kinetics and high-intensity exercise performance in humans
This is the author accepted manuscript. The final version is available from the American Physiological Society via the DOI in this record.The purpose of this study was to compare the effects of L-citrulline (CIT) and L-arginine (ARG) supplementation on nitric oxide (NO) biomarkers, pulmonary O2 uptake (VO2) kinetics and exercise performance. In a randomised, placebo-controlled, cross-over study, ten healthy adult males completed moderate- and severe-intensity cycling exercise on days 6 and 7 of a 7 day supplementation period with placebo (PLA), 6 g•day(-1) of ARG and 6 g•day(-1) of CIT. Compared to PLA, plasma [ARG] was increased by a similar magnitude with ARG and CIT supplementation, but plasma [CIT] was only increased (P0.05). In conclusion, these results suggest that short-term CIT, but not ARG, supplementation can improve blood pressure, VO2 kinetics and exercise performance in healthy adults
Onset of Surface-Tension-Driven Benard Convection
Experiments with shadowgraph visualization reveal a subcritical transition to
a hexagonal convection pattern in thin liquid layers that have a free upper
surface and are heated from below. The measured critical Marangoni number (84)
and observation of hysteresis (3%) agree with theory. In some experiments,
imperfect bifurcation is observed and is attributed to deterministic forcing
caused in part by the lateral boundaries in the experiment.Comment: 4 pages. The RevTeX file has a macro allowing various styles. The
appropriate style is "mypprint" which is the defaul
A face for all seasons:searching for context-specific leadership traits and discovering a general preference for perceived health
Previous research indicates that followers tend to contingently match particular leader qualities to evolutionarily consistent situations requiring collective action (i.e., context-specific cognitive leadership prototypes) and information processing undergoes categorization which ranks certain qualities as first-order context-general and others as second-order context-specific. To further investigate this contingent categorization phenomenon we examined the “attractiveness halo”—a first-order facial cue which significantly biases leadership preferences. While controlling for facial attractiveness, we independently manipulated the underlying facial cues of health and intelligence and then primed participants with four distinct organizational dynamics requiring leadership (i.e., competition vs. cooperation between groups and exploratory change vs. stable exploitation). It was expected that the differing requirements of the four dynamics would contingently select for relatively healthier- or intelligent-looking leaders. We found perceived facial intelligence to be a second-order context-specific trait—for instance, in times requiring a leader to address between-group cooperation—whereas perceived health is significantly preferred across all contexts (i.e., a first-order trait). The results also indicate that facial health positively affects perceived masculinity while facial intelligence negatively affects perceived masculinity, which may partially explain leader choice in some of the environmental contexts. The limitations and a number of implications regarding leadership biases are discussed
Minimum Information about a Neuroscience Investigation (MINI) Electrophysiology
This module represents the formalized opinion of the authors and the CARMEN consortium, which identifies the minimum information required to report the use of electrophysiology in a neuroscience study, for submission to the CARMEN system (www.carmen.org.uk).

Hybrid silicon nanostructures with conductive ligands and their microscopic conductivities
Silicon nanoparticles (SiNPs) functionalized with conjugated molecules promise a potential pathway to generate a new category of thermoelectric materials. While the thermoelectric performance of materials based on phenyl-acetylene capped SiNPs has been proven, their low conductivity is still a problem for their general application. A muon study of phenyl-acetylene capped SiNPs has been recently carried out using the HiFi spectrometer at the Rutherford Appleton Laboratory, measuring the ALC spectra as a function of temperature. The results show a reduction in the measured line width of the resonance above room temperature, suggesting an activated behaviour for this system. This study shows that the muon study could be a powerful method to investigate microscopic conductivity of hybrid thermoelectric materials
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