Superconvergence of Topological Entropy in the Symbolic Dynamics of Substitution Sequences

We consider infinite sequences of superstable orbits (cascades) generated by systematic substitutions of letters in the symbolic dynamics of one-dimensional nonlinear systems in the logistic map universality class. We identify the conditions under which the topological entropy of successive words converges as a double exponential onto the accumulation point, and find the convergence rates analytically for selected cascades. Numerical tests of the convergence of the control parameter reveal a tendency to quantitatively universal double-exponential convergence. Taking a specific physical example, we consider cascades of stable orbits described by symbolic sequences with the symmetries of quasilattices. We show that all quasilattices can be realised as stable trajectories in nonlinear dynamical systems, extending previous results in which two were identified.Comment: This version: updated figures and added discussion of generalised time quasilattices. 17 pages, 4 figure

Aboriginal and Torres Strait Islander People and dementia: a review of the research

This report outlines the prevalence of dementia and modifiable risk factors in Aboriginal and Torres Strait Islander communities. Executive summary The high rate of dementia in Aboriginal and Torres Strait Islander communities requires urgent attention. Aboriginal and Torres Strait Islander people experience dementia at an earlier age then the general population and this, combined with the steadily growing number of older Aboriginal and Torres Strait Islander people, will result in the number of people effected by  dementia growing significantly in the coming years. Although higher rates of dementia have been reported in Aboriginal and Torres Strait Islander people, the disease is often overlooked by Aboriginal and Torres Strait Islander  communities, health workers and service providers. Geographical constraints in the provision of services, a lack of education and awareness in communities and by health workers and the prevalence of other chronic diseases have all posed considerable barriers to the recognition of dementia as an emerging health issue. This paper includes the following recommendations to ensure that Aboriginal and Torres Strait Islander people, family members and communities have access to awareness, information, and appropriate support services for people with dementia

Cochrane dementia group turns 21—older and (slightly) wiser

This invited editorial describes the achievements of the last 21 years of the Cochrane Dementia and Cognitive Improvement Group (DR Quinn is the coordinating editor of the group)

When is Alzheimer’s not dementia—Cochrane commentary on The National Institute on Ageing and Alzheimer’s Association Research Framework for Alzheimer’s Disease

Early 2018 saw the release of new diagnostic guidance on Alzheimer’s disease from the National Institute on Ageing and the Alzheimer’s Association (NIA-AA). This proposed research framework represents a fundamental change in how we think about Alzheimer’s disease, moving from diagnosis based on clinical features to diagnosis based solely on biomarkers. These recommendations are contentious and have important implications for patients, clinicians, policy makers and the pharmaceutical industry. In this commentary, we offer a summary of the NIA-AA research framework. We then focus on five key areas: divorcing neuropathology from the clinical syndrome; the emphasis placed on one dementia subtype; validity of available biomarkers; the changing meaning of the term ‘Alzheimer’s disease’; and the potential for a research framework to influence clinical practice

A multi-faceted intervention to implement guideline care and improve quality of care for older people who present to the emergency department with falls

<p>Abstract</p> <p>Background</p> <p>Guidelines recommend that older people should receive multi-factorial interventions following an injurious fall however there is limited evidence that this is routine practice. We aimed to improve the delivery of evidence based care to patients presenting to the Emergency Department (ED) following a fall.</p> <p>Methods</p> <p>A prospective before and after study was undertaken in the ED of a medium-sized hospital in Perth, Western Australia. Participants comprised 313 community-dwelling patients, aged 65 years and older, presenting to ED as a result of a fall. A multi-faceted strategy to change practice was implemented and included a referral pathway, audit and feedback and additional falls specialist staff. Key measures to show improvements comprised the proportion of patients reviewed by allied health, proportion of patients referred for guideline care, quality of care index, all determined by record extraction.</p> <p>Results</p> <p>Allied health staff increased the proportion of patients being reviewed from 62.7% in the before period to 89% after the intervention (P < 0.001). Before the intervention a referral for comprehensive guideline care occurred for only 6/177 (3.4%) of patients, afterwards for 28/136 (20.6%) (difference = 17.2%, 95% CI 11-23%). Average quality of care index (max score 100) increased from 18.6 (95% CI: 16.7-20.4) to 32.6 (28.6-36.6).</p> <p>Conclusions</p> <p>A multi-faceted change strategy was associated with an improvement in allied health in ED prioritizing the review of ED fallers as well as subsequent referral for comprehensive geriatric care. The processes of multi-disciplinary care also improved, indicating improved care received by the patient.</p

Can physical activity improve the mental health of older adults?

The world population is aging rapidly. Whilst this dramatic demographic change is a desirable and welcome phenomenon, particularly in view of people's increasing longevity, it's social, financial and health consequences can not be ignored. In addition to an increase of many age related physical illnesses, this demographic change will also lead to an increase of a number of mental health problems in older adults and in particular of dementia and depression. Therefore, any health promotion approach that could facilitate introduction of effective primary, secondary and even tertiary prevention strategies in old age psychiatry would be of significant importance. This paper explores physical activity as one of possible health promotion strategies and evaluates the existing evidence that supports its positive effect on cognitive impairment and depression in later life

The Kimberley assessment of depression of older Indigenous Australians: prevalence of depressive disorders, risk factors and validation of the KICA-dep scale

This study aimed to develop a culturally acceptable and valid scale to assess depressive symptoms in older Indigenous Australians, to determine the prevalence of depressive disorders in the older Kimberley community, and to investigate the sociodemographic, lifestyle and clinical factors associated with depression in this population. Methods Cross-sectional survey of adults aged 45 years or over from six remote Indigenous communities in the Kimberley and 30% of those living in Derby, Western Australia. The 11 linguistic and culturally sensitive items of the Kimberley Indigenous Cognitive Assessment of Depression (KICA-dep) scale were derived from the signs and symptoms required to establish the diagnosis of a depressive episode according to the DSM-IV-TR and ICD-10 criteria, and their frequency was rated on a 4-point scale ranging from ‘never’ to ‘all the time’ (range of scores: 0 to 33). The diagnosis of depressive disorder was established after a face-to-face assessment with a consultant psychiatrist. Other measures included sociodemographic and lifestyle factors, and clinical history. Results The study included 250 participants aged 46 to 89 years (mean±SD = 60.9±10.7), of whom 143 (57.2%) were women. The internal reliability of the KICA-dep was 0.88 and the cut-point 7/8 (non-case/case) was associated with 78% sensitivity and 82% specificity for the diagnosis of a depressive disorder. The point-prevalence of a depressive disorder in this population was 7.7%; 4.0% for men and 10.4% for women. Heart problems were associated with increased odds of depression (odds ratio = 3.3, 95% confidence interval = 1.2,8.8). Conclusions The KICA-dep has robust psychometric properties and can be used with confidence as a screening tool for depression among older Indigenous Australians. Depressive disorders are common in this population, possibly because of increased stressors and health morbidities

Reducing depression during the menopausal transition: Study protocol for a randomised controlled trial

Background: The menopausal transition (MT) is a biological inevitability for all ageing women that can be associated with changes in mood, including depressive symptoms. There is tentative evidence that women who develop depression during the MT have greater risk of subsequent depressive episodes, as well as increased health morbidity and mortality. Thus, preventing depression during the MT could enhance both current and the future health and well-being of women. This study aims to test the efficacy of a client-centred health promotion intervention to decrease the 12-month incidence of clinically significant symptoms of depression among women undergoing the MT.Methods/Design: This randomised controlled trial will recruit 300 women undergoing the MT living in the Perth metropolitan area. They will be free of clinically significant symptoms of depression and of psychotic or bipolar disorders. Consenting participants will be stratified for the presence of subsyndromal symptoms of depression and then randomly assigned to the intervention or control group. The intervention will consist of eight telephone health promotion sessions that will provide training in problem solving and education about the MT, healthy ageing, depression and anxiety, and management of chronic health symptoms and problems. The primary outcome of interest is the onset of a major depressive episode according the DSM-IV-TR criteria during the 12-month follow-up or of clinically significant symptoms of depression, as established by a score of 15 or greater on the Patient Health Questionnaire (PHQ-9). Secondary outcomes of interest include changes in the severity of symptoms of depression and anxiety (Hospital Anxiety and Depression Scale, HADS), quality of life (Short Form Health Survey, SF-12), and lifestyle.Discussion: Current evidence shows that depressive symptoms and disorders are leading causes of disability worldwide, and that they are relatively common during the MT. This study will use a multifaceted health promotion intervention with the aim of preventing depression in these women. If successful, the results of this trial will have implications for the management of women undergoing the MT. Trial registration: Australian and New Zealand Clinical Trials Registry ACTRN12613000724774. Date registered: 1 July 2013

The well-being of carers of older Aboriginal people living in the Kimberley region of remote Western Australia: Empowerment, depression, and carer burden

Objective: To describe demographic features and well-being of carers of Aboriginal Australians aged ≥45 years in remote Western Australia. Method: Carer burden, empowerment, and depression were assessed in 124 Aboriginal carers in four remote Aboriginal communities. Results: Carers were aged 38.8 ± 15.0 years, 73.4% were female, and 75.8% were children or grandchildren of the person cared for. The mean Zarit-6 score was 3.7 ± 3.6. Attending high school (odds ratio [OR] = 0.3; 95% confidence interval [CI] = [0.1, 0.7]) and feeling empowered (OR = 0.2; 95% CI = [0.1, 0.8]) were inversely associated with carer burden; female carers were less likely to feel empowered (OR = 0.4; 95% CI = [0.2, 0.9]); and empowerment was inversely associated with depression (OR = 0.3; 95% CI = [0.1, 0.7]). Discussion: Aboriginal carers in remote communities are relatively young and most are children or grandchildren. Carer burden was lower than anticipated. However, existing tools may not adequately measure Aboriginal perspectives. Education and empowerment are key factors which support programs must consider