Realization of macroscopic ratchet effect based on nonperiodic and uneven potentials.

Ratchet devices allow turning an ac input signal into a dc output signal. A ratchet device is set by moving particles driven by zero averages forces on asymmetric potentials. Hybrid nanostructures combining artificially fabricated spin ice nanomagnet arrays with superconducting films have been identified as a good choice to develop ratchet nanodevices. In the current device, the asymmetric potentials are provided by charged Néel walls located in the vertices of spin ice magnetic honeycomb array, whereas the role of moving particles is played by superconducting vortices. We have experimentally obtained ratchet effect for different spin ice I configurations and for vortex lattice moving parallel or perpendicular to magnetic easy axes. Remarkably, the ratchet magnitudes are similar in all the experimental runs; i. e. different spin ice I configurations and in both relevant directions of the vortex lattice motion. We have simulated the interplay between vortex motion directions and a single asymmetric potential. It turns out vortices interact with uneven asymmetric potentials, since they move with trajectories crossing charged Néel walls with different orientations. Moreover, we have found out the asymmetric pair potentials which generate the local ratchet effect. In this rocking ratchet the particles (vortices) on the move are interacting each other (vortex lattice); therefore, the ratchet local effect turns into a global macroscopic effect. In summary, this ratchet device benefits from interacting particles moving in robust and topological protected type I spin ice landscapes.

Little-Parks effect governed by magnetic nanostructures with out-of-plane magnetization.

Little-Parks effect names the oscillations in the superconducting critical temperature as a function of the magnetic field. This effect is related to the geometry of the sample. In this work, we show that this effect can be enhanced and manipulated by the inclusion of magnetic nanostructures with perpendicular magnetization. These magnetic nanodots generate stray fields with enough strength to produce superconducting vortex-antivortex pairs. So that, the L-P effect deviation from the usual geometrical constrictions is due to the interplay between local magnetic stray fields and superconducting vortices. Moreover, we compare our results with a low-stray field sample (i.e. with the dots in magnetic vortex state) showing how the enhancement of the L-P effect can be explained by an increment of the effective size of the nanodots.

Impact of school-based vegetable garden and physical activity coordinated health interventions on weight status and weight-related behaviors of ethnically diverse, low-income students: Study design and baseline data of the Texas, Grow! Eat! Go! (TGEG) cluster-randomized controlled trial.

BACKGROUND: Coordinated, multi-component school-based interventions can improve health behaviors in children, as well as parents, and impact the weight status of students. By leveraging a unique collaboration between Texas AgriLife Extension (a federal, state and county funded educational outreach organization) and the University of Texas School of Public Health, the Texas Grow! Eat! Go! Study (TGEG) modeled the effectiveness of utilizing existing programs and volunteer infrastructure to disseminate an enhanced Coordinated School Health program. The five-year TGEG study was developed to assess the independent and combined impact of gardening, nutrition and physical activity intervention(s) on the prevalence of healthy eating, physical activity and weight status among low-income elementary students. The purpose of this paper is to report on study design, baseline characteristics, intervention approaches, data collection and baseline data. METHODS: The study design for the TGEG study consisted of a factorial group randomized controlled trial (RCT) in which 28 schools were randomly assigned to one of 4 treatment groups: (1) Coordinated Approach to Child Health (CATCH) only (Comparison), (2) CATCH plus school garden intervention [Learn, Grow, Eat & Go! (LGEG)], (3) CATCH plus physical activity intervention [Walk Across Texas (WAT)], and (4) CATCH plus LGEG plus WAT (Combined). The outcome variables include student's weight status, vegetable and sugar sweetened beverage consumption, physical activity, and sedentary behavior. Parents were assessed for home environmental variables including availability of certain foods, social support of student health behaviors, parent engagement and behavior modeling. RESULTS: Descriptive data are presented for students (n = 1369) and parents (n = 1206) at baseline. The sample consisted primarily of Hispanic and African American (53 % and 18 %, respectively) and low-income (i.e., 78 % eligible for Free and Reduced Price School Meals program and 43 % food insecure) students. On average, students did not meet national guidelines for vegetable consumption or physical activity. At baseline, no statistical differences for demographic or key outcome variables among the 4 treatment groups were observed. CONCLUSIONS: The TGEG study targets a population of students and parents at high risk of obesity and related chronic conditions, utilizing a novel and collaborative approach to program formulation and delivery, and a rigorous, randomized study design.

Adaptation of the chronic disease self-management program for cancer survivors: feasibility, acceptability, and lessons for implementation.

Self-management in chronic disease has been shown to improve patient-reported and health care-related outcomes. However, relatively little information about its utility in cancer survivorship is known. We evaluated the feasibility and acceptability of the delivery of an adaptation of the evidence-based Chronic Disease Self-management Program (Stanford) called Cancer Thriving and Surviving (CTS). Triangulated mixed methods were used to capture baseline characteristics and post-program experiences using a combination of closed- and open-ended survey items; emergent coding and simple descriptive statistics were used to summarize the data. Twenty-seven workshops were delivered by 22 CTS leaders to 244 participants between August 2011 and January 2013 in a variety of settings (48 % community, 30 % health care, 22 % regional/community cancer center). Representing a variety of cancer types, about half the participants were 1-3 years post-diagnosis and 45 % were 4 or more years from diagnosis. Program attendance was high with 84 % of participants attending four or more of the six sessions in the workshop. Overall, 95 % of the participants were satisfied with the program content and leaders, and would recommend the program to friends and family. These results confirm the feasibility and acceptability of delivery of a high-fidelity, peer-led model for self-management support for cancer survivors. Expansion of the CTS represents a powerful tool toward improving health-related outcomes in this at-risk population.

Measurement of leisure time satisfaction in family caregivers.

Caregiving is known to limit participation in a variety of roles. Leisure roles are increasingly recognized as important for the well-being of older adults. Little is known, however, about the impact of caregiving on leisure activities, and existing measures are of limited utility in caregiving research. We developed the Leisure Time Satisfaction (LTS) measure to allow further study of the impact of caregiving on caregivers' leisure time satisfaction, the role of leisure in understanding the caregiving process, and whether caregiving interventions improve leisure time satisfaction. The six-item LTS measure shows excellent psychometric properties, including internal consistency, a single factor structure, and convergent validity. Psychometric features are robust across diverse groups of caregivers, including subgroups varying by race/ethnicity and relationship to the care recipient. The LTS measure appears to be a promising tool for inclusion in caregiving research.

Well-being, appraisal, and coping in African-American and Caucasian dementia caregivers: findings from the REACH study.

Although there has been considerable interest in racial differences in family caregiving for persons with dementia, most research to date has either ignored racial diversity or based conclusions on small numbers of caregivers drawn primarily from single site studies. The current study utilized participants from four sites of the REACH (Resources for Enhancing Alzheimer's Caregiver Health) multi-site study to compare well-being, appraisal, and religious coping by race. African-American (n = 295) and Caucasian (n = 425) dementia caregivers from four cities (Birmingham, Memphis, Boston, and Philadelphia) were compared in their demographics, care recipient characteristics, mental and physical health, and psychosocial coping resources including appraisal and religious coping. African-American caregivers reported lower anxiety, better well-being, less use of psychotropic medications, more benign appraisals of stress and perceived benefits of caregiving, and greater religious coping and participation, than Caucasian caregivers. Self-rated health did not differ by race, but African-American caregivers reported more unhealthy behaviors than Caucasian caregivers. Some results were specific to site, possibly due to differences in recruitment strategies, inclusion/exclusion criteria, and regional differences. Adjustment for covariates, including caregiver relationship to the care recipient, gender, age, socioeconomic status, and care recipient behavioral problems, altered few of these differences. Results are discussed in terms of their relevance to psychosocial intervention programs for ethnically diverse caregivers.

Quality of life in diverse groups of midlife women: assessing the influence of menopause, health status and psychosocial and demographic factors.

This paper examines whether menopausal status is associated with global quality of life (QOL) among women aged 40-55 and whether this association varies by race/ethnicity. We further examine the contributions of other health-related and psychosocial factors to QOL and whether these associations vary by racial/ethnic group. Analyses are based on 13,874 women who participated in the multi-ethnic, multi-race study of mid-aged women called the Study of Women's Health Across the Nation (SWAN). Study participants completed a 15-min telephone or in-person interview that contained questions on a variety of health-related topics. Items of interest for these analyses include global QOL, menstrual history (to assess menopausal status), sociodemographics, health status, lifestyle, and psychosocial variables. Results showed that in unadjusted analyses, early perimenopausal women reported lower QOL compared with premenopausal women, but menopausal status was no longer associated with QOL when analyses were adjusted for other variables. In multivariable models, being married and having low levels of perceived stress were associated with better QOL across all racial/ethnic groups. While there were many consistencies across racial/ethnic groups, we also found that the nature of the associations between QOL and education, marital status, perceived stress and social support varied across racial/ethnic groups.

The Behavior Change Consortium: setting the stage for a new century of health behavior-change research.

The Behavior Change Consortium (BCC), a collective of 15 National Institutes of Health-funded behavior-change projects, was conceived with the goal of evaluating the efficacy and effectiveness of novel ways of intervening in diverse populations to reduce tobacco dependence, and improve physical activity, nutrition and other health behaviors. The purpose of this article is to provide a general introduction and context to this theme issue by: (1) reviewing the promises and challenges of past efforts related to promoting change for three key health behaviors; (2) reviewing successful intervention strategies and principles of health behavior change; (3) discussing major theoretical approaches for obtaining successful behavior change; (4) setting BCC activities within the context of recent recommendations for the behavioral and social sciences; and (5) providing an organizational framework for describing each of the projects within this consortium. In addition to the rich database on behavioral outcomes for tobacco dependence, physical activity and diet, the BCC represents a unique opportunity to share data and address cross-cutting intervention research issues critical for strengthening the field of behavior change research.

Judging outcomes in psychosocial interventions for dementia caregivers: the problem of treatment implementation.

PURPOSE: In published dementia caregiver intervention research, there is widespread failure to measure the level at which treatment was implemented as intended, thereby introducing threats to internal and external validity. The purpose of this article is to discuss the importance of inducing and assessing treatment implementation (TI) strategies in caregiving trials and to propose Lichstein's TI model as a potential guide. DESIGN AND METHODS: The efforts of a large cooperative research study of caregiving interventions, Resources for Enhancing Alzheimer's Caregiver Health (REACH), illustrates induction and assessment of the three components of TI: delivery, receipt, and enactment. RESULTS: The approaches taken in REACH vary with the intervention protocols and include using treatment manuals, training and certification of interventionists, and continuous monitoring of actual implementation. IMPLICATIONS: Investigation and description of treatment process variables allows researchers to understand which aspects of the intervention are responsible for therapeutic change, potentially resulting in development of more efficacious and efficient interventions.

The effects of exercise on the quality of life of frail older adults: a preplanned meta-analysis of the FICSIT trials.

The Frailty and Injuries: Cooperative Studies of Intervention Techniques (FICSIT) was a linked series of randomized clinical trials focused on the benefits of exercise in the frail elderly. This article uses covariate-adjusted preplanned meta-analyses of FICSIT data to evaluate the effect of exercise on quality of life (QOL) outcomes (N = 1,733; age = 73.4 +/- 6.1 years). Results indicate that (a) exercise produced a small but significant improvement in the emotional health component of QOL, trended toward an improved social component, and did not effect perceptions of general health; (b) exercise-related joint and muscle stresses did not increase bodily pain; and (c) QOL improvements were independent of changes in physical functioning. We conclude that exercise can improve QOL in the frail elderly but that the magnitude of the improvement is modest in size. The benefits of a meta-analytical approach for documenting efficacy outcomes across different types of interventions are discussed.

Targeted mailed materials and the Medicare beneficiary: increasing mammogram screening among the elderly.

OBJECTIVES: Older women have the highest breast cancer rates but are underscreened relative to their risk. Racial/ethnic minority women especially have low screening rates, often because of financial constraints. In response, Medicare introduced subsidized biennial mammogram benefits in 1991. This study examined the effect on mammography rates of an intervention that informed women about the Medicare benefit. METHODS: A list frame method of subject selection was used to select random samples of eligible women from the Health Care Financing Administration's master beneficiary file. Women were interviewed by telephone in 1991 (N = 917) before the targeted mailing and in 1993 (N = 922). One control and 2 treatment communities participated. RESULTS: Mammogram use increased significantly among minorities in the treatment groups. Among minorities who received the intervention, Black women were twice as likely (odds ratio = 1.97) and Hispanic women were more than twice as likely (odds ratio = 2.33) to undergo screening relative to their untreated cohorts. CONCLUSIONS: A targeted low-cost mailed intervention can help increase screening rates among elderly minority women. The Health Care Financing Administration should promote its benefits aggressively if it expects to reach its target--elderly beneficiaries.

Issues of aging and adherence to health interventions.

This review article describes several processes and considerations that are important to adherence in aging research and potential strategies that could be used to facilitate adherence among older adults. In many large aging trials participants are purposefully selected to reduce the risk of suboptimal adherence and retention. This selection often involves screening out those with barriers such as transportation needs, sensory deficits, functional dependence, major diseases limiting life expectancy, or apparent psychological distress. However, trends toward extending interventions to the general population of older adults require specific knowledge about the circumstances and processes that support adherence among older adults or the conditions that make them vulnerable to adherence problems. Addressing the diversity of needs, expectations, and capabilities of older adults that promote adherence is a key consideration in aging research. Control Clin Trials 2000;21:171S-183S

The economic implications of self-care: the effect of lifestyle, functional adaptations, and medical self-care among a national sample of Medicare beneficiaries.

OBJECTIVES: Self-care includes actions taken by individuals to promote or ensure their health, to recover from diseases or injuries, or to manage their effects. This study measured associations between self-care practices (lifestyle practices, adaptations to functional limitations, and medical self-care) and Medicare expenditures among a national sample of adults 65 years and older. METHODS: Regression models of Medicare use and expenditures were estimated by using the National Survey of Self-Care and Aging and Medicare claims for 4 years following a baseline interview. RESULTS: Lifestyle factors (swimming and walking) and functional adaptations (general home modifications) were associated with reductions in monthly Medicare expenditures over a 12-month follow-up period. Expenditure reductions were found over the 48-month follow-up period for participation in active sports, gardening, and medical self-care. Practices associated with increases in expenditures included smoking, physical exercise (possibly of a more strenuous nature), and specific home modifications. CONCLUSIONS: Certain self-care practices appear to have significant implications for Medicare expenditures and presumptively for the health status of older adults. Such practices should be encouraged among older adults as a matter of national health policy.

Communication between older patients and their physicians.

This article provides an overview of communication between older patients and their physicians. The authors discuss distinctive features of geriatric medical visits and empirical investigations of communication between physicians and older patients in real life clinical encounters highlighting the content, interactional processes, and outcomes of care. They also discuss strategies for improving communication between physicians and older patients using new and innovative technologies. The authors conclude that healing in its broadest sense can occur only through a humanistic approach to geriatric care.

Attitudes toward menopause and aging across ethnic/racial groups.

OBJECTIVE: Attitudes have a potential role to play in the experience of menopause. The objective of this study was to examine the degree to which attitudes toward menopause and aging vary across ethnic groups and menopausal status (ie, premenopausal through postmenopausal). METHODS: More than 16,000 women were interviewed by telephone as part of the Study of Women's Health Across the Nation. They represented five ethnic/racial groups (African American, white, Chinese American, Japanese American, and Hispanic) from seven geographical sites (Boston, MA; Pittsburgh, PA; Chicago, IL; Michigan; New Jersey; and northern and southern California). RESULTS: African American women were significantly more positive in attitude. The least positive groups were the less acculturated Chinese American and Japanese American women. Menopausal status was not a consistent predictor of attitude across ethnic groups. CONCLUSIONS: In general, women's attitudes toward menopause range from neutral to positive. Ethnic groups within the United States vary slightly, but reliably, in their attitudes toward menopause and aging. Factors other than those directly associated with menopausal status seem to play a role in attitude.

Prevalence and impact of caregiving: a detailed comparison between dementia and nondementia caregivers.

Analyzing data from more than 1,500 family caregivers from the 1996 National Caregiver Survey, this study documents the ways in which dementia care is different from other types of family caregiving. Not only do dementia caregivers spend significantly more hours per week providing care than nondementia caregivers, they also report greater impacts in terms of employment complications, caregiver strain, mental and physical health problems, time for leisure and other family members, and family conflict. Differential impacts remain even after controlling for intensity of caregiving involvement and sociodemographic factors. Study findings suggest the need to tailor programs and services to the unique challenges faced by dementia caregivers.

Gender, self-reported depressive symptoms, and sleep disturbance among older community-dwelling persons. FICSIT group. Frailty and Injuries: Cooperative Studies of Intervention Techniques.

The purposes of this report are: (1) to investigate the association between sleep disturbances and depressive symptomatology in older adults; (2) to evaluate the degree to which gender serves to mediate this relationship; and (3) to determine whether several predefined covariates help to explain the association between sleep disturbance and depressive symptoms. This is a retrospective and cross-sectional analysis of baseline data from 485 elderly adults enrolled in three of the eight clinical sites participating in the Frailty and Injuries: Cooperative Studies of Intervention Techniques (FICSIT) trials. FICSIT was a linked series of randomized clinical trials which evaluated the impact of various exercise interventions on several measures of frailty in older adults. Women reported more depressive symptoms and more sleep disturbances than men. Sleep disturbances were independently associated with depressive symptoms, bodily pain, a history of falling, limited education, being married, and being female. Gender interactions suggest that, although women reported more depressive symptoms and more chronic health conditions than men, both may be more important predictors of sleep disturbance in men. By contrast, being married may be more predictive in women. Finally, the data suggest a stronger relationship between sleep disturbance and depressive symptoms in men than in women.

Predicting mortality from community surveys of older adults: the importance of self-rated functional ability.

Using data from the 1990 baseline of the National Survey of Self-Care and Aging (NSSCA), and nearly three years of follow-up mortality data, we examined the association between self-rated functional ability, a global measure of perceived ability of function independently, and mortality among a national sample of older adults. The study included 3,485 subjects selected from the Medicare Beneficiary Files according to a stratified random sampling design, with approximately equal numbers of adults by gender in each of three age categories, 65-74, 75-84, and 85 and over. Self-rated functional ability was found to have an independent contribution to the subsequent risk of death among older adults. Using multivariate models that accounted for self-rated health, age, gender, medical conditions, functional status, and assistance from others, poor self-ratings on this single item nearly doubled the risk of death during the follow-up period. These findings suggest the importance, for both researchers and clinicians, of measuring the potential prognostic importance of self-ratings of health and self-ratings of functional ability among older adults.