Evaluating risk of dementia in older people: a pathway to personalized prevention?

This editorial refers to ‘Impact of cardiovascular risk factors and genetics on 10-year absolute risk of dementia: risk charts for targeted prevention’, by R. Rasmussen et al., on page 4024

The Relationship of Bilingualism Compared to Monolingualism to the Risk of Cognitive Decline or Dementia: A Systematic Review and Meta-Analysis

BACKGROUND: Bilingualism may contribute to cognitive reserve, protect against cognitive decline, and delay the onset of dementia. OBJECTIVE: We systematically reviewed evidence about the effect of bilingualism on subsequent cognitive decline or dementia. METHODS: We searched electronic databases and references for longitudinal studies comparing cognitive decline in people who were bilingual with those who were monolingual and evaluated study quality. We conducted meta-analyses using random effects models to calculate pooled odds ratio of incident dementia. RESULTS: We included 13/1,156 eligible articles. Meta-analysis of prospective studies of the effects of bilingualism on future dementia gave a combined Odds Ratio of dementia of 0.96 (95% CI 0.74-1.23) in bilingual participants (n = 5,527) compared to monolinguals. Most retrospective studies found that bilingual people were reported to develop symptoms of cognitive decline at a later age than monolingual participants. CONCLUSION: We did not find that bilingualism protects from cognitive decline or dementia from prospective studies. Retrospective studies are more prone to confounding by education, or cultural differences in presentation to dementia services and are therefore not suited to establishing causative links between risk factors and outcomes

The pulsating DA white dwarf star EC 14012-1446: results from four epochs of time-resolved photometry

The pulsating DA white dwarfs are the coolest degenerate stars that undergo self-driven oscillations. Understanding their interior structure will help to understand the previous evolution of the star. To this end, we report the analysis of more than 200 h of time-resolved CCD photometry of the pulsating DA white dwarf star EC 14012-1446 acquired during four observing epochs in three different years, including a coordinated three-site campaign. A total of 19 independent frequencies in the star's light variations together with 148 combination signals up to fifth order could be detected. We are unable to obtain the period spacing of the normal modes and therefore a mass estimate of the star, but we infer a fairly short rotation period of 0.61 +/- 0.03 d, assuming the rotationally split modes are l=1. The pulsation modes of the star undergo amplitude and frequency variations, in the sense that modes with higher radial overtone show more pronounced variability and that amplitude changes are always accompanied by frequency variations. Most of the second-order combination frequencies detected have amplitudes that are a function of their parent mode amplitudes, but we found a few cases of possible resonantly excited modes. We point out the complications in the analysis and interpretation of data sets of pulsating white dwarfs that are affected by combination frequencies of the form f_A+f_B-f_C intruding into the frequency range of the independent modes.Comment: 14 pages, 6 figures, 6 tables. MNRAS, in pres

How people with dementia and carers understand and react to social functioning changes in mild dementia: a UK-based qualitative study

OBJECTIVES: To analyse people with dementia and their family carers' attribution of social changes in dementia and the consequences of these attributions. DESIGN: Qualitative study, using a semi-structured interview guide. Individual interviews continued to theoretical saturation. Two researchers independently analysed interview transcripts. SETTING AND PARTICIPANTS: People with mild dementia and family carers purposively selected from London-based memory services for diverse demographic characteristics to encompass a range of experiences. PRIMARY AND SECONDARY OUTCOMES: Attribution of social changes experienced by the person with dementia and the consequences of these attributions. RESULTS: We interviewed nine people with dementia and nine carers, encompassing a range of age, ethnicity and educational backgrounds.Both groups reported that the person with dementia had changed socially. People with dementia tended to give one or two explanations for social change, but carers usually suggested several. People with dementia were often socially embarrassed or less interested in going out, and they or their relatives' physical illness or fear of falls led to reduced social activity. Carers often attributed not going out to a choice or premorbid personality. Carers found that their relative needed more support to go out than they could give and carers needed time to themselves because of carer stress or other problems from which they shielded the person with dementia. Additionally, there was decreased opportunity to socialise, as people were bereaved of friends and family. Participants acknowledged the direct impact of dementia symptoms on their ability to socially engage but sometimes decided to give up socialising when they knew they had dementia. There were negative consequences from social changes being attributed to factors such as choice, rather than dementia. CONCLUSION: Clinicians should ask about social changes in people with dementia. Explaining that these may be due to dementia and considering strategies to overcome them may be beneficial

Culturally tailored therapeutic interventions for people affected by dementia: a systematic review and new conceptual model

Most people with dementia live in low and middle-income countries (LMICs) and there is an increased dementia prevalence in some minority ethnic groups in high-income countries. However, most interventions are devised for majority populations in high-income countries. We systematically searched 11 electronic databases for culturally tailored interventions for people with dementia and their family carers in LMICs and minority ethnic groups, without limit on language or date. 23 of 22 221 studies fulfilled inclusion criteria. Interventions adapted peripheral intervention components by, for example, translation and reducing the stigma of psychological therapy by emphasising physical illness and learning. Core therapeutic components were not changed. We found evidence-based, multicomponent interventions adapted for Latinx carers were acceptable, feasible, and effective in the USA and Columbia. Interventions developed for carers in India were effective there but not in other LMICs. Culturally adapted cognitive stimulation therapy was acceptable and effective for people with dementia in sub-Saharan Africa. We propose a new conceptual model from our findings to aid implementation of culturally appropriate treatments for people affected by dementia in LMICs and minority ethnic groups. Evidence-based interventions need cultural adaptation for different settings with therapeutic components retained. If they are acceptable, feasible, and remain effective then full effectiveness trials are unnecessary

Evolutionary Timescale of the DAV G117-B15A: The Most Stable Optical Clock Known

We observe G117-B15A, the most precise optical clock known, to measure the rate of change of the main pulsation period of this blue-edge DAV white dwarf. Even though the obtained value is only within 1 sigma, Pdot = (2.3 +/- 1.4) x 10^{-15} s/s, it is already constraining the evolutionary timescale of this cooling white dwarf star.Comment: Accepted for publication in ApJ

Rapid Orbital Decay in the 12.75-Minute Binary White Dwarf J0651+2844

We report the detection of orbital decay in the 12.75-minute, detached binary white dwarf (WD) SDSS J065133.338+284423.37 (hereafter J0651). Our photometric observations over a 13 month baseline constrain the orbital period to 765.206543(55) s and indicate that the orbit is decreasing at a rate of (-9.8 +/- 2.8) x 10(-12) s s(-1) (or -0.31 +/- 0.09 ms yr(-1)). We revise the system parameters based on our new photometric and spectroscopic observations: J0651 contains two WDs with M-1 = 0.26 +/- 0.04 M-circle dot and M-2 = 0.50 +/- 0.04 M-circle dot. General relativity predicts orbital decay due to gravitational wave radiation of (-8.2 +/- 1.7) x 10(-12) s s(-1) (or -0.26 +/- 0.05 ms yr(-1)). Our observed rate of orbital decay is consistent with this expectation. J0651 is currently the second-loudest gravitational wave source known in the milli-Hertz range and the loudest non-interacting binary, which makes it an excellent verification source for future missions aimed at directly detecting gravitational waves. Our work establishes the feasibility of monitoring this system's orbital period decay at optical wavelengths.NSF AST-0909107, AST-1008734Norman Hackerman Advanced Research Program 003658-0252-2009Astronom

Re-defining the Empirical ZZ Ceti Instability Strip

We use the new ZZ Ceti stars (hydrogen atmosphere white dwarf variables; DAVs) discovered within the Sloan Digital Sky Survey (Mukadam et al. 2004) to re-define the empirical ZZ Ceti instability strip. This is the first time since the discovery of white dwarf variables in 1968 that we have a homogeneous set of spectra acquired using the same instrument on the same telescope, and with consistent data reductions, for a statistically significant sample of ZZ Ceti stars. The homogeneity of the spectra reduces the scatter in the spectroscopic temperatures and we find a narrow instability strip of width ~950K, from 10850--11800K. We question the purity of the DAV instability strip as we find several non-variables within. We present our best fit for the red edge and our constraint for the blue edge of the instability strip, determined using a statistical approach.Comment: 14 pages, 5 pages, ApJ paper, accepte