Direct-write three-dimensional nanofabrication of nanopyramids and nanocones on Si by nanotumefaction using a helium ion microscope.

The recently commercialized helium ion microscope (HIM) has already demonstrated its outstanding imaging capabilities in terms of resolution, surface sensitivity, depth of field and ease of charge compensation. Here, we show its exceptional patterning capabilities by fabricating dense lines and three-dimensional (3D) nanostructures on a Si substrate. Small focusing spot size and confined ion-Si interaction volume of a high-energy helium ion beam account for the high resolution in HIM patterning. We demonstrate that a set of resolvable parallel lines with a half pitch as small as 3.5 nm can be achieved. During helium ion bombardment of the Si surface, implantation outperforms milling due to the small mass of the helium ions, which produces tumefaction instead of depression in the Si surface. The Si surface tumefaction is the result of different kinetic processes including diffusion, coalescence and nanobubble formation of the implanted ions, and is found to be very stable structurally at room temperature. Under appropriate conditions, a linear dependence of the surface swollen height on the ion doses can be observed. This relation has enabled us to fabricate nanopyramids and nanocones, thus demonstrating that HIM patterning provides a new 'bottom-up' approach to fabricate 3D nanostructures. This surface tumefaction method is direct, both positioning and height accurate, and free of resist, etch, mode and precursor, and it promises new applications in nanoimprint mold fabrication and photomask clear defect reparation.

Mammography screening and breast self-examination among minority women in public housing projects: the impact of physician recommendation.

This exploratory study examined the impact of physician recommendations and other factors on mammography screening and breast-self examination (BSE) among African American and Hispanic women in public housing communities. We surveyed a randomly selected sample of low-income households from three low-income communities (n = 291), which included both African Americans and Hispanic women. Data for this paper are reported only on women who were 40 years and older head of the households (n = 120 women, including 74 Hispanics and 46 African Americans), since they meet the age criterion for mammography screening. Our analyses indicated that only 46% of women obtained mammography in the previous 12 months, with no significant differences between the Hispanic and African American women in mammography rates. Physicians' recommendations were among the most significant and substantial predictors of obtaining a mammogram or performing BSE. Further, odds were also higher for those who had insurance coverage. In addition, our data also indicated that almost one out of four women, aged 40 and older participants in this study, claimed that their health care providers never told them they needed a mammogram or never told them that they should perform BSE, with no significant differences between Hispanic and African Americans. Our analyses points to an urgent need for intervention to inform and motivate the service providers in underserved communities to motivate breast cancer screening (BCS) among minority women. Additionally, our examination points to the need for urgent interventions targeting minority women, particularly women with no medical insurance for breast cancer screening.

Sensory impairments and subjective well-being among aged African American persons.

The limited number of studies concerning the prevalence of hearing loss and vision impairment and their causes, and the lack of strategies to prevent or treat the deleterious effects of hearing loss and vision impairment, point to a significant gap in the knowledge base concerning aged minority populations. This cross-sectional study evaluated the relationship between vision and hearing impairment and psychological well-being among a sample of 988 elderly African American persons. Fair or poor vision or hearing was reported for 36.5% and 26% of our sample, respectively. Reported prevalence rates for these impairments are considerably higher than rates previously documented in comparable studies of elderly people conducted in general (i.e., predominantly White) populations. Eighty-four percent of our study participants attempted to improve their vision through the use of eyeglasses. By contrast, only 4.3% of individuals in the study who described their hearing as poor reported using hearing aids. Using multivariate analysis and other related variables that have previously been identified as common predictors of psychological well-being, the findings of this study suggest that poor vision is independently associated with a lower level of psychological well-being among aged African Americans even after adjusting for sociodemographic characteristics, functional limitations, perceived health status, and cognition. Poor hearing was also found to be associated with a lower level of psychological well-being; however, this relationship was not independent but was mediated by the effect of hearing on functional status. These data indicate considerable potential for improved psychological well-being for African American elderly people through visual and audiological rehabilitation.

Paranoid ideation among elderly African American persons.

PURPOSE: The prevalence and correlates of paranoid ideation were investigated. DESIGN AND METHODS: On the basis of a sample of 998 independently living elderly African American persons in a cross-sectional study, the study used the Brief Symptom Inventory to measure paranoid ideation and 14 independent variables, including demographic characteristics, cognitive deficit, depression, self-reported memory functioning, emotional and instrumental support, stressful life events, limitation of daily activities, self-rated health status, and self-rated hearing and vision. RESULTS AND IMPLICATIONS: Paranoid ideation (symptoms of paranoia) was found in 10% of this sample. A multiple regression analysis of the data revealed that of the 14 independent variables used in this study, 6 (income, instrumental support, hearing, stressful life events, self-reported memory deficit, and depression) showed a significant relationship with paranoid ideation.

Correlates of HIV risk-taking behaviors among African-American college students: the effect of HIV knowledge, motivation, and behavioral skills.

This study identifies theoretically based predictors of condom use in a sample of 253 sexually active African-American college students recruited from two historically African-American colleges. The Information-Motivation-Behavioral (IMB) skills model of AIDS-preventive behavior was employed to delineate the roles of HIV/AIDS knowledge, experiences with and attitudes toward condom use, peer influences, perceived vulnerability, monogamy, and behavioral skills. A predictive structural equation model revealed significant predictors of more condom use including: male gender, more sexual HIV knowledge, positive experiences and attitudes about condom use, nonmonogamy, and greater behavioral skills. Results imply that attention to behavioral skills for negotiating safer sex and training in the proper use of condoms are key elements in reducing high risk behaviors. Increasing the specific knowledge level of college students regarding the subtleties of sexual transmission of HIV is important and should be addressed. Heightening students' awareness of the limited protection of serial monogamy, and the need to address gender-specific training regarding required behavior change to reduce transmission of HIV should be an additional goal of college health professionals.

Correlates of recency of eye examination among elderly African-Americans.

This study uses a theoretical model of health services utilization to assess the effects of predisposing, enabling, and need-for-care characteristics on recency of eye examinations among a sample of 998 elderly African-American persons. More than 64% of participants reported that they had had eye examinations within the last 12 months. Multiple logistics regression analysis explains 13.3% of the variance of eye examinations. This data indicates that recency of eye examination is related to health locus of control, private insurance, Medicare, insulin-dependent diabetes, and presence of eye disease. No significant relationship between recency of eye examination and self-rated health status, social support, vision impairment, and non-insulin-dependent diabetes were detected. The lack of association between non-insulin-dependent diabetes and the recency of eye examination suggests that the amount of preventive care in place may not be adequate. This data shows that the unique contributions of need characteristics account for a major variance of recency of eye examination. However, enabling characteristics play a significant role in sending the participants of this study to eye-specialists, even after need-for-care factors are held constant.

Emergency department utilization, hospital admissions, and physician visits among elderly African American persons.

This study uses a theoretical model of health services utilization to examine (a) emergency department utilization, (b) hospital admissions, and (c) office-based physician visits among a sample of 998 low-income elderly African American persons. Poisson Regression analysis was used to estimate the parameters specified in the Andersen behavioral model. Some of the more interesting results include the following: (a) a greater frequency of emergency room visits among respondents with a lower level of accessibility to physician services, (b) a lack of a significant relationship between some chronic illnesses such as diabetes and heart problems and the frequency of office-based physician visits, (c) a greater number of hospital admissions among insured persons, and (d) a significant impact of the health locus of control indexes on all three types of health care utilization. The results of this study challenge the assumption that hospital and emergency use are the results of nondiscretionary behavior.

A multivariate comparison of elderly African Americans and Caucasians voting behavior: how do social, health, psychological, and political variables effect their voting?

No study until now has examined the impact of the physical and psychological condition on voter turnout among elderly African Americans and Caucasians. Utilizing data from a national survey (Aging in the Eighties) and using multiple logistic regression, the present study examines the impact of health rating and life satisfaction as well as other socio-psychological characteristics on voting turnout among elderly Caucasian and African Americans. The results provide some empirical evidence that the pattern of election participation can be significantly influenced by the self-assessment of health and life satisfaction. For elderly Caucasians self-assessment of health is significantly related to voting behavior, whereas among elderly African Americans life satisfaction shows significant impact on turnout. Elderly African Americans who identified their personal political philosophy as "liberal" were more likely to vote, while among elderly Caucasians, those who identified their personal political philosophy as "conservative" were more likely to vote. In addition, SES, age, and organizational activity proved to have significantly independent impact on elderly Caucasian turnout, whereas among elderly African Americans, education was detected as a significant predictor.