1,375 research outputs found
Conceptual Ecological Modelling of Shallow Sublittoral Coarse Sediment Habitats to Inform Indicator Selection
The purpose of this study is to produce a series of Conceptual Ecological Models (CEMs)that represent the Shallow Sublittoral Coarse Sediment Habitat in the UK.
CEMs are diagrammatic representations of the influences and processes that occur within an ecosystem. They can be used to identify critical aspects of an ecosystem that may be taken forward for further study, or serve as the basis for
the selection of indicators for environmental monitoring purposes. The models produced by this project are 'control
diagrams', representing the state of the environment free from adverse anthropogenic impacts and pressures
Increased physical fitness is associated with higher executive functioning in people with dementia
Physical fitness (PF) has been associated with improved cognition in older age, but less is known about its effects on different cognitive domains in individuals diagnosed with dementia. We explored the associations between PF and cognitive performance in 40 healthy elderly and 30 individuals with dementia. Participants completed a battery of standardized cognitive tests (Mini-Mental State Exam, Verbal Fluency, Prospective and Retrospective Memory Questionnaire, Clock Drawing, and California Verbal Learning Test) and were classified into high versus low levels of PF based on their score on the Physical Fitness Questionnaire. Analyses took into account age, gender, education, occupation, head injury, Internet use, brain training, and past levels of exercise and revealed overall benefits of PF, in particular for the people with dementia. Discriminant analysis showed high accuracy of reclassification, with most errors being due to the misclassification of dementia cases as healthy when they had high PF. The first discriminant function accounted for 83% of the variance. Using individual estimates of this function, which reflected global cognitive performance, confirmed the beneficial role of PF in dementia, even when taking into account age, past level of exercise, and the number of years since the dementia diagnosis. Finally, univariate analyses confirmed the differential sensitivity of the cognitive tests, with MMSE and clock drawing showing reliable interaction effects. This work shows that PF is associated with a reduced level of cognitive deterioration expected with dementia, especially in executive functioning and provides empirical support for the cognitive benefits of interventions promoting PF for individuals with dementia
Exercise Increases Neural Stem Cell Number in a GH-Dependent Manner, Augmenting the Regenerative Response in Aged Mice
The exercise-induced enhancement of learning and
memory, and its ability to slow age-related cognitive
decline in humans led us to investigate whether
running stimulates periventricular (PVR) neural stem
cells (NSCs) in aging mice, thereby augmenting the
regenerative capacity of the brain. To establish a
benchmark of normal aging on endogenous NSCs, we
harvested the PVR from serial vibratome sections
through the lateral ventricles of juvenile (6-8 weeks), 6,
12, 18, and 24-month-old mice, culturing the cells in the
neural colony forming cell assay. A significant decline
in NSC frequency was apparent by 6-months (~40%)
ultimately resulting in a ~90% reduction by 24-months.
Concurrent with this decline was a progressive loss in
regenerative capacity, as reflected by an incomplete
repopulation of neurosphere-forming cells following
gamma cell irradiation-induced depletion of the PVR.
However voluntary exercise (i.e. 21 days of running)
significantly increased NSC frequency in mic
Physical activity to improve cognition in older adults: can physical activity programs enriched with cognitive challenges enhance the effects? A systematic review and meta-analysis
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Habitual physical activity (HPA) as a factor in sustained executive function in Alzheimer-type dementia: a cohort study
Evidence from studies on healthy older adults and mild cognitive impairment (MCI) populations suggests that physical activity interventions have a positive effect on executive function. In this study, we consider whether HPA is positively associated with executive function in Alzheimer's disease (AD). Eighty-two participants with a diagnosis of mild to moderate AD completed six measures of executive function. Objective measures of physical status were taken. In addition, informants completed questionnaires on the participants’ HPA and other lifestyle factors. A composite measure of executive function was the primary outcome. A multistage multiple regression was used to determine how much variance HPA accounted for. The final model comprised disease severity, cognitive reserve, cognitive activities, neuropsychiatric status and HPA status. The final model accounted for a total of 57% of the variance of executive performance, of which HPA itself accounted for 8% of the variance. HPA status is associated executive performance in an AD population even after controlling for key covariates. The findings encourage clinicians to recommend HPA and its cognitive benefits to AD patients and their carers
Quadrupedal movement training improves markers of cognition and joint repositioning
Introduction - Exercise, and in particular balance and coordination related activities such as dance, appear to have positive effects on cognitive function, as well as neurodegenerative conditions such as dementia and Parkinson’s disease. Quadrupedal gait training is a movement system requiring coordination of all four limbs that has previously been associated with cognitive development in children. There is currently little research into the effect of complex QDP movements on cognitive function in adults.
Purpose - To determine the effects of a novel four-week quadrupedal gait training programme on markers of cognitive function and joint reposition sense in healthy adults.
Methods - Twenty-two physically active sports science students (15 male and 7 female) were divided into two groups: a training group (TG) and a control group (CG). All participants completed the Wisconsin Card Sorting Task (WCST) and were tested for joint reposition sense before and after a four-week intervention, during which time the TG completed a series of progressive and challenging quadrupedal movement training sessions.
Results - Participants in the TG showed significant improvements in the WCST, with improvements in perseverative errors, non-perseverative errors, and conceptual level response. This improvement was not found in the CG. Joint reposition sense also improved for the TG, but only at 20 degrees of shoulder flexion. 
Conclusions - Performance of a novel, progressive, and challenging task, requiring the coordination of all 4 limbs, has a beneficial impact on cognitive flexibility, and in joint reposition sense, although only at the specific joint angle directly targeted by the training. The findings are consistent with other studies showing improvements in executive function and joint reposition sense following physical activity
Walking with a rollator and the level of physical intensity in adults 75 years of age or older.
Eggermont LH, van Heuvelen MJ, van Keeken BL, Hollander AP, Scherder EJ. Walking with a rollator and the level of physical intensity in adults 75 years of age or older. Objective: To determine whether walking with a rollator by persons 75 years of age or older is of sufficient intensity to improve aerobic fitness. Design: A cross-sectional cohort study. Setting: University movement laboratory. Participants: Fifteen subjects 75 years of age or older (mean age, 83.7y) who could only walk by using a rollator. Interventions: Not applicable. Main Outcome Measures: During 6 minutes of self-paced treadmill walking using a rollator at a mean walking speed of 0.6m/s, oxygen uptake (V̇
Preserved differentiation between physical activity and cognitive performance across young, middle, and older adulthood over 8 years.
Objectives: A critical question in the activity engagement literature is whether physical exercise alters the trajectory of age-related cognitive decline (differential preservation) or is associated with enhanced baseline cognitive ability (preserved differentiation). Further, investigations considering that these relations may differ across young, middle, and older adulthood are rare. Method: We evaluated data from the PATH Through Life Project, where participants aged 20-24, 40-44, and 60-64 years at baseline (n = 6,869) completed physical activity (PA; mild, moderate, and vigorous) and cognitive measurements thrice over 8 years. Results: Multilevel models accounting for employment status, sex, education, health, and mental and social activity showed that between-person differences in PA participation positively predicted baseline performance on fluid cognitive ability (perceptual speed, short-term memory, working memory, and episodic memory). These effects were similar across age groups, but strongest for the youngest cohort, for whom there was also evidence of covariation between within-person change in PA and cognitive score. PA was not associated with change in cognition over time. DISCUSSION: Results support preserved differentiation, where physically active adults have higher initial cognitive ability, and the advantage is maintained over time. PA appears to be unique in showing differences across young, middle, and older adulthood in predicting cognition
Exercise, cognition and Alzheimer’s disease: More is not necessarily better
Regional hypoperfusion, associated with a reduction in cerebral metabolism, is a hallmark of Alzheimer’s disease (AD) and contributes to cognitive decline. Cerebral perfusion and hence cognition can be enhanced by exercise. The present review describes first how the effects of exercise on cerebral perfusion in AD are mediated by nitric oxide (NO) and tissue-type plasminogen activator, the release of which is regulated by NO. A conclusion of clinical relevance is that exercise may not be beneficial for the cognitive functioning of all people with dementia if cardiovascular risk factors are present.
The extent to which cardiovascular risk factors play a role in the selection of older people with dementia in clinical studies will be addressed in the second part of the review in which the effects of exercise on cognition are presented. Only eight relevant studies were found in the literature, emphasizing the paucity of studies in this field. Positive effects of exercise on cognition were reported in seven studies, including two that excluded and two that included patients with cardiovascular risk factors. These findings suggest that cardiovascular risk factors do not necessarily undo the beneficial effects of exercise on cognition in cognitively impaired people. Further research is called for, in view of the limitations of the clinical studies reviewed here.
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