Little is known about how the proportions of dependency states have changed between generational cohorts of older people. We aimed to estimate years lived in different dependency states at age 65 ...years in 1991 and 2011, and new projections of future demand for care.
In this population-based study, we compared two Cognitive Function and Ageing Studies (CFAS I and CFAS II) of older people (aged ≥65 years) who were permanently registered with a general practice in three defined geographical areas (Cambridgeshire, Newcastle, and Nottingham; UK). These studies were done two decades apart (1991 and 2011). General practices provided lists of individuals to be contacted and were asked to exclude those who had died or might die over the next month. Baseline interviews were done in the community and care homes. Participants were stratified by age, and interviews occurred only after written informed consent was obtained. Information collected included basic sociodemographics, cognitive status, urinary incontinence, and self-reported ability to do activities of daily living. CFAS I was assigned as the 1991 cohort and CFAS II as the 2011 cohort, and both studies provided prevalence estimates of dependency in four states: high dependency (24-h care), medium dependency (daily care), low dependency (less than daily), and independent. Years in each dependency state were calculated by Sullivan's method. To project future demands for social care, the proportions in each dependency state (by age group and sex) were applied to the 2014 England population projections.
Between 1991 and 2011, there were significant increases in years lived from age 65 years with low dependency (1·7 years 95% CI 1·0–2·4 for men and 2·4 years 1·8–3·1 for women) and increases with high dependency (0·9 years 0·2–1·7 for men and 1·3 years 0·5–2·1 for women). The majority of men's extra years of life were spent independent (36·3%) or with low dependency (36·3%) whereas for women the majority were spent with low dependency (58·0%), and only 4·8% were 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 71 215 care home places by 2025.
On average older men now spend 2·4 years and women 3·0 years with substantial care needs, and most will live in the community. These findings have considerable implications for families of older people who provide the majority of unpaid care, but the findings also provide valuable new information for governments and care providers planning the resources and funding required for the care of their future ageing populations.
Medical Research Council (G9901400) and (G06010220), with support from the National Institute for Health Research Comprehensive Local research networks in West Anglia and Trent, UK, and Neurodegenerative Disease Research Network in Newcastle, UK.
Autopsy measures of Alzheimer's disease neuropathology have been leveraged as endophenotypes in previous genome-wide association studies (GWAS). However, despite evidence of sex differences in ...Alzheimer's disease risk, sex-stratified models have not been incorporated into previous GWAS analyses. We looked for sex-specific genetic associations with Alzheimer's disease endophenotypes from six brain bank data repositories. The pooled dataset included 2701 males and 3275 females, the majority of whom were diagnosed with Alzheimer's disease at autopsy (70%). Sex-stratified GWAS were performed within each dataset and then meta-analysed. Loci that reached genome-wide significance (P < 5 × 10-8) in stratified models were further assessed for sex interactions. Additional analyses were performed in independent datasets leveraging cognitive, neuroimaging and CSF endophenotypes, along with age-at-onset data. Outside of the APOE region, one locus on chromosome 7 (rs34331204) showed a sex-specific association with neurofibrillary tangles among males (P = 2.5 × 10-8) but not females (P = 0.85, sex-interaction P = 2.9 × 10-4). In follow-up analyses, rs34331204 was also associated with hippocampal volume, executive function, and age-at-onset only among males. These results implicate a novel locus that confers male-specific protection from tau pathology and highlight the value of assessing genetic associations in a sex-specific manner.
Research indicates that stress is linked to cognitive dysfunction. However, few community-based studies have explored the relationship between perceived stress and cognitive decline, and fewer still ...have utilized cognitive domains rather than a global measure of cognition.
We examined the relation between perceived stress and the rate of decline in different cognitive domains.
Participants were older African Americans without dementia from the Minority Aging Research Study (MARS; N = 467, mean age: 73 years, SD: 6.1 years). A battery of 19 cognitive tests was administered at baseline and at annual intervals for up to 9 years (mean follow-up: 4 years), from which composite measures of global cognitive function and five specific cognitive domains were derived. The four-item Cohen's Perceived Stress Scale (PSS) was also administered at baseline.
In linear mixed-effects models adjusted for age, sex, education, and vascular risk factors, higher perceived stress was related to faster declines in global cognition (β = -0.019; SE: 0.008; t
= -2.46), episodic memory (β = -0.022; SE: 0.011; t
= -1.99), and visuospatial ability (β = -0.021; SE: 0.009; t
= -2.38) all p < 0.05. Findings were similar in subsequent models adjusted for demographics, vascular diseases, and depressive symptoms.
Results indicate that older African Americans with higher levels of perceived stress have more rapid declines in global cognition than those with lower levels, most notably for episodic memory and visuospatial ability.
Transparent conductors based on few‐layer graphene (FLG) intercalated with ferric chloride (FeCl3) have an outstandingly low sheet resistance and high optical transparency. FeCl3‐FLGs outperform the ...current limit of transparent conductors such as indium tin oxide, carbon‐nanotube films, and doped graphene materials. This makes FeCl3‐FLG materials the best transparent conductor for optoelectronic devices.
Cognitive abilities of older persons range from normal, to mild cognitive impairment, to dementia. Few large longitudinal studies have compared the natural history of mild cognitive impairment with ...similar persons without cognitive impairment.
Participants were older Catholic clergy without dementia, 211 with mild cognitive impairment and 587 without cognitive impairment, who underwent annual clinical evaluation for AD and an assessment of different cognitive abilities. Cognitive performance tests were summarized to yield a composite measure of global cognitive function and separate summary measures of episodic memory, semantic memory, working memory, perceptual speed, and visuospatial ability. The authors compared the risk of death, risk of incident AD, and rates of change in global cognition and different cognitive domains among persons with mild cognitive impairment to those without cognitive impairment. All models controlled for age, sex, and education.
On average, persons with mild cognitive impairment had significantly lower scores at baseline in all cognitive domains. Over an average of 4.5 years of follow-up, 30% of persons with mild cognitive impairment died, a rate 1.7 times higher than those without cognitive impairment (95% CI, 1.2 to 2.5). In addition, 64 (34%) persons with mild cognitive impairment developed AD, a rate 3.1 times higher than those without cognitive impairment (95% CI, 2.1 to 4.5). Finally, persons with mild cognitive impairment declined significantly faster on measures of episodic memory, semantic memory, and perceptual speed, but not on measures of working memory or visuospatial ability, as compared with persons without cognitive impairment.
Mild cognitive impairment is associated with an increased risk of death and incident AD, and a greater rate of decline in selected cognitive abilities.
There is increasing recognition of the importance of cortical microinfarcts to overall brain health, cognition, and Alzheimer dementia. Cerebral small vessel pathologies are associated with ...microinfarcts and frequently coexist with Alzheimer disease; however, the extent to which Aβ (amyloid beta) and tau pathology modulates microvascular pathogenesis is not fully understood. Study objective was to examine the relationship of small vessel pathologies, arteriolosclerosis, and cerebral amyloid angiopathy, with cortical microinfarcts in people with differing levels of Aβ or tau tangle burden.
Participants were 1489 autopsied older people (mean age at death, 89 years; 67% women) from 1 of 3 ongoing clinical-pathological cohort studies of aging. Neuropathological evaluation identified cortical Aβ and tau tangle burden using immunohistochemistry in 8 brain regions, provided semiquantitative grading of cerebral vessel pathologies, and identified the presence of cortical microinfarcts. Logistic regression models adjusted for demographics and atherosclerosis and examined whether Aβ or tau tangle burden modified relations between small vessel pathologies and cortical microinfarcts.
Cortical microinfarcts were present in 17% of older people, moderate-to-severe cerebral amyloid angiopathy pathology in 36%, and arteriolosclerosis in 34%. In logistic regression models, we found interactions with Aβ and tau tangles, reflecting that the association between arteriolosclerosis and cortical microinfarcts was stronger in the context of greater Aβ (estimate, 0.15; SE=0.07;
=0.02) and tau tangle burden (estimate, 0.13; SE=0.06;
=0.02). Interactions also emerged for cerebral amyloid angiopathy, suggesting that the association between cerebral amyloid angiopathy and cortical microinfarcts is more robust in the presence of higher Aβ (estimate, 0.27; SE=0.07;
<0.001) and tangle burden (estimate, 0.16; SE=0.06;
=0.005).
These findings suggest that in the presence of elevated Aβ or tangle pathology, small vessel pathologies are associated with greater microvascular tissue injury, highlighting a potential link between neurodegenerative and vascular mechanisms.
Pseudorelativistic Dirac quasiparticles have emerged in a plethora of artificial graphene systems that mimic the underlying honeycomb symmetry of graphene. However, it is notoriously difficult to ...manipulate their properties without modifying the lattice structure. Here we theoretically investigate polaritons supported by honeycomb metasurfaces and, despite the trivial nature of the resonant elements, we unveil rich Dirac physics stemming from a non-trivial winding in the light-matter interaction. The metasurfaces simultaneously exhibit two distinct species of massless Dirac polaritons, namely type-I and type-II. By modifying only the photonic environment via an enclosing cavity, one can manipulate the location of the type-II Dirac points, leading to qualitatively different polariton phases. This enables one to alter the fundamental properties of the emergent Dirac polaritons while preserving the lattice structure-a unique scenario which has no analog in real or artificial graphene systems. Exploiting the photonic environment will thus give rise to unexplored Dirac physics at the subwavelength scale.
We show that dye-doped polymers open an interesting route to controlling light at the nanoscale. Just as for the much better known metal-based plasmonic systems, propagating and localized modes are ...possible. We show that the attractive features offered by plasmonics, specifically enhanced optical fields and subwavelength field confinement, are also available with these materials. They thus open a new opportunity in nanophotonics in which fabrication and functionality might be achieved by harnessing molecular and supramolecular chemistry.
Social networks are frequently cited as vital for facilitating successful adaptation and transformation in linked social–ecological systems to overcome pressing resource management challenges. Yet ...confusion remains over the precise nature of adaptation vs. transformation and the specific social network structures that facilitate these processes. Here, we adopt a network perspective to theorize a continuum of structural capacities in social–ecological systems that set the stage for effective adaptation and transformation. We begin by drawing on the resilience literature and the multilayered action situation to link processes of change in social–ecological systems to decision making across multiple layers of rules underpinning societal organization. We then present a framework that hypothesizes seven specific social–ecological network configurations that lay the structural foundation necessary for facilitating adaptation and transformation, given the type and magnitude of human action required. A key contribution of the framework is explicit consideration of how social networks relate to ecological structures and the particular environmental problem at hand. Of the seven configurations identified, three are linked to capacities conducive to adaptation and three to transformation, and one is hypothesized to be important for facilitating both processes. We discuss how our theoretical framework can be applied in practice by highlighting existing empirical examples from related environmental governance contexts. Further extension of our hypotheses, particularly as more data become available, can ultimately help guide the design of institutional arrangements to be more effective at dealing with change.
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