944 research outputs found

    Wave transformation across a macrotidal shore platform under low to moderate energy conditions

    Get PDF
    We investigate how waves are transformed across a shore platform as this is a central question in rock coast geomorphology. We present results from deployment of three pressure transducers over four days, across a sloping, wide (~200 m) cliff-backed shore platform in a macrotidal setting, in South Wales, United Kingdom. Cross shore variations in wave heights were evident under the predominantly low to moderate (significant wave height < 1.4 m) energy conditions measured. At the outer transducer 50 m from the seaward edge of the platform (163 m from the cliff) high tide water depths were 8+ m meaning that waves crossed the shore platform without breaking. At the mid platform position water depth was 5 m. Water depth at the inner transducer (6 m from the cliff platform junction) at high tide was 1.4 m. This shallow water depth forced wave breaking, thereby limiting wave heights on the inner platform. Maximum wave height at the middle and inner transducers were 2.41 and 2.39 m respectively and significant wave height 1.35 m and 1.34 m respectively. Inner platform high tide wave heights were generally larger where energy was up to 335% greater than near the seaward edge where waves were smaller. Infragravity energy was less than 13% of the total energy spectra with energy in the swell, wind and capillary frequencies accounting for 87% of the total energy. Wave transformation is thus spatially variable and is strongly modulated by platform elevation and the tidal range. While shore platforms in microtidal environments have been shown to be highly dissipative, in this macro-tidal setting up to 90% of the offshore wave energy reached the landward cliff at high tide, so that the shore platform cliff is much more reflective

    Community environment, cognitive impairment and dementia in later life: results from the Cognitive Function and Ageing Study

    Get PDF
    Background: Few studies have investigated the impact of the community environment, as distinct from area deprivation, on cognition in later life. This study explores cross-sectional associations between cognitive impairment and dementia and environmental features at the community level in older people. Method: The postcodes of the 2424 participants in the year-10 interview of the Cognitive Function and Ageing Study in England were mapped into small area level geographical units (Lower-layer Super Output Areas) and linked to environmental data in government statistics. Multilevel logistic regression was conducted to investigate associations between cognitive impairment (defined as MMSE3 in GMS-AGECAT) and community level measurements including area deprivation, natural environment, land use mix and crime. Sensitivity analyses tested the impact of people moving residence within the last two years. Results: Higher levels of area deprivation and crime were not significantly associated with cognitive impairment and dementia after accounting for individual level factors. Living in areas with high land use mix was significantly associated with a nearly 60% reduced odds of dementia (OR: 0.4; 95% CI: 0.2, 0.8) after adjusting for individual level factors and area deprivation, but there was no linear trend for cognitive impairment. Increased odds of dementia (OR: 2.2, 95% CI: 1.2, 4.2) and cognitive impairment (OR: 1.4, 95% CI: 1.0, 2.0) were found in the highest quartile of natural environment availability. Findings were robust to exclusion of the recently relocated. Conclusion: Features of land use have complex associations with cognitive impairment and dementia. Further investigations should focus on environmental influences on cognition to inform health and social policies

    The association between community environment and cognitive function: a systematic review.

    Get PDF
    PURPOSES: The aim of this study is to review the published evidence on the association between community environment and cognitive function in older people, focusing on the findings and a critique of the existing studies. METHODS: A literature search was conducted to identify studies linking the community environment and cognitive function in older people. The results and methodological factors, including the definition of community, individual level characteristics and the measurements of cognitive function and community environment were extracted from each study. The measurements of community environment were mainly categorized into two types: compositional, generated by aggregating individual and household data (community-level socioeconomic status, deprivation index) and contextual, targeting at the features of built or social environment in local areas (green space, street conditions, crime rate). RESULTS: Fourteen of the fifteen studies used compositional measurements such as community-level socioeconomic status and deprivation index and significant associations were found in eleven studies. Some individual level factors (ethnicity, genotype and socioeconomic status) were found to modify the association between community environment and cognitive function. Few contextual measurements were included in the existing studies. A conceptual framework for the pathway from community environment to cognitive function of older people is provided in this review. CONCLUSIONS: To disentangle the additional effect of place from individual risk factors and investigate the casual direction of community environment and cognition in later life, longitudinal studies with measurements targeting built and social environments of community and change of cognitive functions over time need to be included in future studies.Yu-Tzu Wu received a PhD scholarship from the Cambridge Trust, University of Cambridge. A. Matthew Prina is supported by the Medical Research Council [Grant number K021907/1].This is the final published manuscript. It is published by Springer here: http://dx.doi.org/10.1007/s00127-014-0945-

    The Relationship Between Cognitive Performance Using Tests Assessing a Range of Cognitive Domains and Future Dementia Diagnosis in a British Cohort: A Ten-Year Prospective Study.

    Get PDF
    BACKGROUND: Exploring the domains of cognitive function which are most strongly associated with future dementia may help with understanding risk factors for, and the natural history of dementia. OBJECTIVE: To examine the association of performance on a range of cognitive tests (both global and domain specific) with subsequent diagnosis of dementia through health services in a population of relatively healthy men and women and risk of future dementia. METHODS: We examined the association between performance on different cognitive tests as well as a global score and future dementia risk ascertained through health record linkage in a cohort of 8,581 individuals (aged 48-92 years) between 2004-2019 with almost 15 years follow-up (average of 10 years) before and after adjustment for socio-demographic, lifestyle, and health characteristics. RESULTS: Those with poor performance for global cognition (bottom 10%) were almost four times as likely to receive a dementia diagnosis from health services over the next 15 years than those who performed well HR = 3.51 (95% CI 2.61, 4.71 p < 0.001) after adjustment for socioeconomic, lifestyle, and biological factors and also prevalent disease. Poor cognition performance in multiple tests was associated with 10-fold increased risk compared to those not performing poorly in any test HR = 10.82 (95% CI 6.85, 17.10 p < 0.001). CONCLUSION: Deficits across multiple cognitive domains substantially increase risk of future dementia over and above neuropsychological test scores ten years prior to a clinical diagnosis. These findings may help further understanding of the natural history of dementia and how such measures could contribute to strengthening future models of dementia.This work was supported by the Medical Research Council, UK (MRC) http://www.mrc.ac.uk/ (Ref: MR/N003284/1) Cancer Research UK http://www.cancerresearchuk. org/ (CRUK, Ref: C864/A8257) and NIHR https://www.nihr.ac.uk (Ref: NF-SI-0616-10090 to [CB]). The clinic for EPIC- Norfolk 3HC was funded by Research into Aging, now known as Age UK http://www.ageuk.org.uk/ (Grant Ref: 262). The pilot phase was supported by MRC (Ref: G9502233) and CRUK (Ref: C864/ A2883)

    An investigation of the population impact of variation in HbA1c levels in older people in England and Wales: from a population based multi-centre longitudinal study.

    Get PDF
    BACKGROUND: Diabetes is common in the older population and is increasing. Glycated hemoglobin (HbA1c) is an indicator of average blood glucose concentration over the past three months. The HbA1c test is currently one of clinical methods used to check diabetes control. Recent studies have suggested diabetes is a risk factor for dementia, cognitive dysfunction and physical disability. In addition, there have reported the relationship between HbA1c and mortality on all cause, cardiovascular disease and cognitive function, but few studies have investigated the relationship concentrating on the older population. The aim of this study is to investigate the association between the level of HbA1c and mortality from all causes, incident cardiovascular disease, cognitive decline and physical disability in people aged 65 and over in England and Wales. METHODS: 1139 men and women aged 69 years and over who were participants in a ten year population based ageing multi-centre, longitudinal study who had HbA1c measurements after 5-6 years of follow up. All participants were flagged for death notification including causes at the Office of National Statistics. Information on health including vascular conditions, cognitive status, physical function and dementia were available from the study both before and after the HbA1c measurement. Survival analyses and logistic regression were conducted. RESULTS: Mortality from all causes, cardiovascular and ischaemic heart disease increased with increasing HbA1c. Participants with diagnosed diabetes or who had HbA1c > or = 7% but no self-reported diabetes had increased mortality risk from all causes and cardiovascular diseases. The respondents in the group HbA1c > or = 7% who had not been diagnosed with diabetes had a significantly higher risk (odds ratio = 4.8 95% CI: 1.1 to 21.6) of developing dementia. Individuals who had self-reported diabetes but a HbA1c level < 7% had mortality and dementia incidence comparable to individuals without diabetes and HbA1c < 7%. CONCLUSION: The findings support previous reports that bio-markers of glucose metabolism are associated with long term outcomes, such as mortality and dementia

    Is late-life dependency increasing or not? A comparison of the Cognitive Function and Ageing Studies (CFAS)

    Get PDF
    Background: Little is known about how dependency levels have changed between generational cohorts of older people. We estimated years lived in different care states at age 65 in 1991 and 2011 and new projections of future demand for care. Methods: Two population-based studies of older people in defined geographical areas conducted two decades apart (the Cognitive Function and Ageing Studies) provided prevalence estimates of dependency in four states: high (24-hour care); medium (daily care); low (less than daily); independent. Years in each dependency state were calculated by Sullivan’s method. To project future demand, the proportions in each dependency state (by age group and sex) were applied to the 2014 England population projections. Findings: Between 1991 and 2011 there were significant increases in years lived from age 65 with low (men:1·7 years, 95%CI 1·0-2·4; women:2·4 years, 95%CI 1·8-3·1) and high dependency (men:0·9 years, 95%CI 0·2-1·7; women:1·3 years, 95%CI 0·5-2·1). The majority of men’s extra years of life were independent (36%) or with low dependency (36%) whilst for women the majority were spent with low dependency (58%), only 5% being independent. There were substantial reductions in the proportions with medium and high dependency who lived in care homes, although, if these dependency and care home proportions remain constant in the future, further population ageing will require an extra 71,000 care home places by 2025. Interpretation: On average older men now spend 2.4 years and women 3.0 years with substantial care needs (medium or high dependency), and most will live in the community. These findings have considerable implications for older people’s families who provide the majority of unpaid care, but the findings also supply valuable new information for governments and care providers planning the resources and funding required for the care of their future ageing populations

    Intentional weight loss in overweight and obese individuals and cognitive function: a systematic review and meta-analysis.

    Get PDF
    High adiposity in middle age is associated with higher dementia risk. The association between weight loss and cognitive function in older adults is still controversial. A meta-analysis was undertaken to estimate the effectiveness of intentional weight loss on cognitive function in overweight and obese adults. A structured strategy was used to search randomized and non-randomized studies reporting the effect of intentional and significant weight loss on cognitive function in overweight and obese subjects. Information on study design, age, nutritional status, weight-loss strategy, weight lost and cognitive testing was extracted. A random-effect meta-analysis was conducted to obtain summary effect estimates for memory and attention-executive domains. Twelve studies met inclusion criteria. Seven were randomized trials and the remaining five included a control group. A low-order significant effect was found for an improvement in cognitive performance with weight loss in memory (effect size 0.13, 95% CI 0.00-0.26, P=0.04) and attention/executive functioning (effect size 0.14, 95% CI 0.01-0.27, P<0.001). Studies were heterogeneous in study design, sample selection, weight-loss intervention and assessment of cognitive function. Weight loss appears to be associated with low-order improvements in executive/attention functioning and memory in obese but not in overweight individual

    The association between depressive symptoms in the community, non-psychiatric hospital admission and hospital outcomes: a systematic review.

    Get PDF
    OBJECTIVES: This paper aims to systematically review observational studies that have analysed whether depressive symptoms in the community are associated with higher general hospital admissions, longer hospital stays and increased risk of re-admission. METHODS: We identified prospective studies that looked at depressive symptoms in the community as a risk factor for non-psychiatric general hospital admissions, length of stay or risk of re-admission. The search was carried out on MEDLINE, PsycINFO, Cochrane Library Database, and followed up with contact with authors and scanning of reference lists. RESULTS: Eleven studies fulfilled our inclusion and exclusion criteria, and all were deemed to be of moderate to high quality. Meta-analysis of seven studies with relevant data suggested that depressive symptoms may be a predictor of subsequent admission to a general hospital in unadjusted analyses (RR=1.36, 95% CI: 1.28-1.44), but findings after adjustment for confounding variables were inconsistent. The narrative synthesis also reported depressive symptoms to be independently associated with longer length of stay, and higher re-admission risk. CONCLUSIONS: Depressive symptoms are associated with a higher risk of hospitalisation, longer length of stay and a higher re-admission risk. Some of these associations may be mediated by other factors, and should be explored in more details.No funding bodies had any role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The authors have no competing interests to report. No specific funding was set aside for this project. Matthew Prina was supported by the Medical Research Council [grant number RG56433].This is the final published version. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.jpsychores.2014.11.00
    • …
    corecore