Design of wavelet-based ECG detector for implantable cardiac pacemakers.

A wavelet Electrocardiogram (ECG) detector for low-power implantable cardiac pacemakers is presented in this paper. The proposed wavelet-based ECG detector consists of a wavelet decomposer with wavelet filter banks, a QRS complex detector of hypothesis testing with wavelet-demodulated ECG signals, and a noise detector with zero-crossing points. In order to achieve high detection accuracy with low power consumption, a multi-scaled product algorithm and soft-threshold algorithm are efficiently exploited in our ECG detector implementation. Our algorithmic and architectural level approaches have been implemented and fabricated in a standard 0.35 µm CMOS technology. The testchip including a low-power analog-to-digital converter (ADC) shows a low detection error-rate of 0.196% and low power consumption of 19.02 µW with a 3 V supply voltage.

Hand biometric recognition based on fused hand geometry and vascular patterns.

A hand biometric authentication method based on measurements of the user's hand geometry and vascular pattern is proposed. To acquire the hand geometry, the thickness of the side view of the hand, the K-curvature with a hand-shaped chain code, the lengths and angles of the finger valleys, and the lengths and profiles of the fingers were used, and for the vascular pattern, the direction-based vascular-pattern extraction method was used, and thus, a new multimodal biometric approach is proposed. The proposed multimodal biometric system uses only one image to extract the feature points. This system can be configured for low-cost devices. Our multimodal biometric-approach hand-geometry (the side view of the hand and the back of hand) and vascular-pattern recognition method performs at the score level. The results of our study showed that the equal error rate of the proposed system was 0.06%.

Polarization-extinction-based detection of DNA hybridization in situ using a nanoparticle wire-grid polarizer.

Metallic wires can discriminate light polarization due to strong absorption of electric fields oscillating in parallel to wires. Here, we explore polarization-based biosensing of DNA hybridization in situ by employing metal target-conjugated nanoparticles to form a wire-grid polarizer (WGP) as complementary DNA strands hybridize. Experimental results using gold nanoparticles of 15 nm diameter to form a WGP of 400 nm period suggest that polarization extinction can detect DNA hybridization with a limit of detection in the range of 1 nM concentration. The sensitivity may be improved by more than an order of magnitude if larger nanoparticles are employed to define WGPs at a period between 400 and 500 nm.

Micronutrient quality of weight-loss diets that focus on macronutrients: results from the A TO Z study.

BACKGROUND: Information on the micronutrient quality of alternative weight-loss diets is limited, despite the significant public health relevance. OBJECTIVE: Micronutrient intake was compared between overweight or obese women randomly assigned to 4 popular diets that varied primarily in macronutrient distribution. DESIGN: Dietary data were collected from women in the Atkins (n = 73), Zone (n = 73), LEARN (Lifestyle, Exercise, Attitudes, Relationships, Nutrition) (n = 73), and Ornish (n = 72) diet groups by using 3-d, unannounced 24-h recalls at baseline and after 8 wk of instruction. Nutrient intakes were compared between groups at 8 wk and within groups for 8-wk changes in risk of micronutrient inadequacy. RESULTS: At 8 wk, significant differences were observed between groups for all macronutrients and for many micronutrients (P < 0.0001). Energy intake decreased from baseline in all 4 groups but was similar between groups. At 8 wk, a significant proportion of individuals shifted to intakes associated with risk of inadequacy (P < 0.05) in the Atkins group for thiamine, folic acid, vitamin C, iron, and magnesium; in the LEARN group for vitamin E, thiamine, and magnesium; and in the Ornish group for vitamins E and B-12 and zinc. In contrast, for the Zone group, the risk of inadequacy significantly decreased for vitamins A, E, K, and C (P < 0.05), and no significant increases in risk of inadequacy were observed for other micronutrients. CONCLUSIONS: Weight-loss diets that focus on macronutrient composition should attend to the overall quality of the diet, including the adequacy of micronutrient intakes. Concerning calorie-restricted diets, there may be a micronutrient advantage to diets providing moderately low carbohydrate amounts and that contain nutrient-dense foods.

Development of the Community Healthy Living Index: a tool to foster healthy environments for the prevention of obesity and chronic disease.

OBJECTIVES: This paper presents a new, comprehensive tool for communities to assess opportunities for active living and healthy eating and to mobilize all sectors of society to conquer obesity and chronic disease. METHOD: Relevant existing tools and input from an expert panel were considered to draft the Community Healthy Living Index (CHLI). CHLI covers five major sectors where people live, work, learn, and play: schools, afterschools, work sites, neighborhoods, and the community-at-large. CHLI and the accompanying procedures enable community teams to assess programs, the physical environment, and policies related to healthy living and to plan improvement strategies. In 2008, with local YMCAs acting as conveners, community assessment teams from six US communities pilot-tested CHLI for cognitive response testing, inter-rater reliability, and implementation feasibility. CHLI was revised to reflect the test results. RESULTS: Pilot analyses demonstrated that the process was feasible, with most questions being interpreted as intended and showing substantial to almost perfect agreement between raters. The final CHLI is being disseminated nationally. CONCLUSIONS: Preliminary data illustrate CHLI obtains reliable results and is feasible to implement. CHLI is a promising tool for community-based prevention efforts to draw attention to opportunities for healthy living and create impetus for community changes.

Poverty, near-poverty, and hardship around the time of pregnancy.

To describe income levels and the prevalence of major hardships among women during or just before pregnancy. We separately analyzed 2002-2006 population-based postpartum survey data from California's Maternal and Infant Health Assessment (n = 18,332) and 19 states participating in CDC's Pregnancy Risk Assessment Monitoring System (n = 143,452) to examine income and several hardships (divorce/separation, domestic violence, homelessness, financial difficulties, spouse/partner's or respondent's involuntary job loss or incarceration, and, in California only, food insecurity and no social support) during/just before pregnancy. In both samples, over 30% of women were poor (income 400% FPL experienced one or more hardships. These findings paint a disturbing picture of experiences around the time of pregnancy in the United States for many women giving birth and their children, particularly because 60% had previous births. The high prevalence of low income and of serious hardships during pregnancy is of concern, given previous research documenting the adverse health consequences of these experiences and recognition of pregnancy as a critical period for health throughout the life course. Low income and major hardships around the time of pregnancy should be addressed as mainstream U.S. maternal-infant health and social policy issues.

Potential implications of missing income data in population-based surveys: an example from a postpartum survey in California.

OBJECTIVES: Income data are often missing for substantial proportions of survey participants and these records are often dropped from analyses. To explore the implications of excluding records with missing income, we examined characteristics of survey participants with and without income information. METHODS: Using statewide population-based postpartum survey data from the California Maternal and Infant Health Assessment, we compared the age, education, parity, marital status, timely prenatal care initiation, and neighborhood poverty characteristics of women with and without reported income data, overall, and by race/ethnicity/nativity. RESULTS: Overall, compared with respondents who reported income, respondents with missing income information generally appeared younger, less educated, and of lower parity. They were more likely to be unmarried, to have received delayed or no prenatal care, and to reside in poor neighborhoods; and they generally appeared more similar to lower- than higher-income women. However, the patterns appeared to vary by racial/ethnic/nativity group. For example, among U.S.-born African American women, the characteristics of the missing-income group were generally similar to those of low-income women, while European American women with missing income information more closely resembled their moderate-income counterparts. CONCLUSIONS: Respondents with missing income information may not be a random subset of population-based survey participants and may differ on other relevant sociodemographic characteristics. Before deciding how to deal analytically with missing income information, researchers should examine relevant characteristics and consider how different approaches could affect study findings. Particularly for ethnically diverse populations, we recommend including a missing income category or employing multiple-imputation techniques rather than excluding those records.

Socioeconomic and food-related physical characteristics of the neighbourhood environment are associated with body mass index.

OBJECTIVE: To determine whether socioeconomic and food-related physical characteristics of the neighbourhood are associated with body mass index (BMI; kg/m(2)) independently of individual-level sociodemographic and behavioural characteristics. DESIGN AND METHODS: Observational study using (1) individual-level data previously gathered in five cross-sectional surveys conducted by the Stanford Heart Disease Prevention Program between 1979 and 1990 and (2) neighbourhood-level data from (a) the census to describe socioeconomic characteristics and (b) data obtained from government and commercial sources to describe exposure to different types of retail food stores as measured by store proximity, and count of stores per square mile. Data were analysed using multilevel modelling procedures. The setting was 82 neighbourhoods in agricultural regions of California. PARTICIPANTS: 7595 adults, aged 25-74 years. RESULTS: After adjusting for age, gender, ethnicity, individual-level socioeconomic status, smoking, physical activity and nutrition knowledge, it was found that (1) adults who lived in low socioeconomic neighbourhoods had a higher mean BMI than adults who lived in high socioeconomic neighbourhoods; (2) higher neighbourhood density of small grocery stores was associated with higher BMI among women; and (3) closer proximity to chain supermarkets was associated with higher BMI among women. CONCLUSION: Living in low socioeconomic neighbourhoods, and in environments where healthy food is not readily available, is found to be associated with increased obesity risk. Unlike other studies which examined populations in other parts of the US, a positive association between living close to supermarkets and reduced obesity risk was not found in this study. A better understanding of the mechanisms by which neighbourhood physical characteristics influence obesity risk is needed.

Comparison of the Atkins, Zone, Ornish, and LEARN diets for change in weight and related risk factors among overweight premenopausal women: the A TO Z Weight Loss Study: a randomized trial.

CONTEXT: Popular diets, particularly those low in carbohydrates, have challenged current recommendations advising a low-fat, high-carbohydrate diet for weight loss. Potential benefits and risks have not been tested adequately. OBJECTIVE: To compare 4 weight-loss diets representing a spectrum of low to high carbohydrate intake for effects on weight loss and related metabolic variables. DESIGN, SETTING, AND PARTICIPANTS: Twelve-month randomized trial conducted in the United States from February 2003 to October 2005 among 311 free-living, overweight/obese (body mass index, 27-40) nondiabetic, premenopausal women. INTERVENTION: Participants were randomly assigned to follow the Atkins (n = 77), Zone (n = 79), LEARN (n = 79), or Ornish (n = 76) diets and received weekly instruction for 2 months, then an additional 10-month follow-up. MAIN OUTCOME MEASURES: Weight loss at 12 months was the primary outcome. Secondary outcomes included lipid profile (low-density lipoprotein, high-density lipoprotein, and non-high-density lipoprotein cholesterol, and triglyceride levels), percentage of body fat, waist-hip ratio, fasting insulin and glucose levels, and blood pressure. Outcomes were assessed at months 0, 2, 6, and 12. The Tukey studentized range test was used to adjust for multiple testing. RESULTS: Weight loss was greater for women in the Atkins diet group compared with the other diet groups at 12 months, and mean 12-month weight loss was significantly different between the Atkins and Zone diets (P<.05). Mean 12-month weight loss was as follows: Atkins, -4.7 kg (95% confidence interval [CI], -6.3 to -3.1 kg), Zone, -1.6 kg (95% CI, -2.8 to -0.4 kg), LEARN, -2.6 kg (-3.8 to -1.3 kg), and Ornish, -2.2 kg (-3.6 to -0.8 kg). Weight loss was not statistically different among the Zone, LEARN, and Ornish groups. At 12 months, secondary outcomes for the Atkins group were comparable with or more favorable than the other diet groups. CONCLUSIONS: In this study, premenopausal overweight and obese women assigned to follow the Atkins diet, which had the lowest carbohydrate intake, lost more weight at 12 months than women assigned to follow the Zone diet, and had experienced comparable or more favorable metabolic effects than those assigned to the Zone, Ornish, or LEARN diets [corrected] While questions remain about long-term effects and mechanisms, a low-carbohydrate, high-protein, high-fat diet may be considered a feasible alternative recommendation for weight loss. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00079573.

Ten-year changes in cancer-related health behaviors and screening practices among Latino women and men in California.

OBJECTIVE: This study examines changes in cancer-related health behaviors and risk factors (overweight/obesity, unhealthy diet, high alcohol use, and smoking), and screening practices related to cervical, breast, and colorectal cancer among Latinos of predominantly Mexican origin in Monterey County, California. DESIGN: Data is from two cross-sectional surveys, conducted in 1990 and 2000, that included 919 women and 774 men from a community sample, and 276 men from an agricultural labor camp sample (ages 18-64). RESULTS: Over the 10-year period, the prevalence of obesity increased by 48% among community women, 47% among community men, and 91% among labor camp men. Although consumption of fruits and vegetables remained low and consumption of fried foods remained high, other diet-related behaviors showed significant improvements (e.g. milk consumption shifted from whole-fat to lower-fat among women from the community and men from the labor camps, use of lard or meat fat when cooking decreased among women and men from the community). In addition, alcohol intake decreased among men from both samples, as did smoking among labor camp men. There were large improvements for annual pap and mammography screening (increases from 53 to 71% for pap testing, and from 15 to 53% for mammography screening) but annual blood stool testing remained infrequent and unchanged. CONCLUSION: These findings highlight the need for interventions and policies that improve knowledge, preventive care, and social environments to sustain improvements and address areas of special need in cancer prevention for Latinos, especially related to obesity and colorectal screening.

Contrasting socioeconomic profiles related to healthier lifestyles in China and the United States.

Health disparity by socioeconomic status has recently become an important public health concern. Socioeconomic status may affect health status through several pathways including lifestyle choices. The authors tested the link between socioeconomic status and lifestyle in China (in 1993) and in the United States (in 1994-1996), countries with high contrasts in development, to understand health discrepancy issues cross-nationally. Healthfulness of lifestyle was measured using the Lifestyle Index, a summary score that integrates four key lifestyle factors: diet, physical activity, smoking, and alcohol consumption. Income and education were used as indicators of socioeconomic status. In China, as socioeconomic status improved, lifestyle was less healthy (relative odds for the highest socioeconomic status group = 0.19, 95% confidence interval: 0.10, 0.35). Conversely, in the United States, higher socioeconomic status was related to a healthier lifestyle (relative odds for the highest socioeconomic status group = 3.81, 95% confidence interval: 2.94, 4.94). The contrasting relation between socioeconomic status and lifestyle depicts different phases of the lifestyle transition (changes in lifestyles accompanying economic development). The differences may in part explain why nutrition-related noncommunicable diseases are more prevalent in the developing world among people with a high socioeconomic status, whereas often the opposite is found in developed societies. Public health programs may benefit by advising each socioeconomic status group separately, while considering the country's level of development.

A cross-national comparison of lifestyle between China and the United States, using a comprehensive cross-national measurement tool of the healthfulness of lifestyles: the Lifestyle Index.

BACKGROUND: Extensive studies have revealed the importance of a healthy lifestyle and the role of each lifestyle factor in health. However, lifestyle factors have rarely been studied simultaneously. The authors propose an integrated approach to summarize total healthfulness of lifestyles and to enhance understanding of lifestyle patterns across countries. METHODS: The authors created an overall measure of lifestyle called the Lifestyle Index (LI), integrating diet, physical activity, smoking, and alcohol use to provide a global tool of monitoring healthfulness and patterns of lifestyles. Using the LI, the authors conducted a cross-national comparison between China (n = 8352) and the United States (n = 9750). RESULTS: The LI effectively reflected the healthfulness of lifestyle components in both countries. The mean of the LI scores was slightly higher in China than the US. Scores of diet quality, physical activity, and smoking were higher in China, but scores of alcohol behavior were higher in the US. Similar lifestyle patterns but different unhealthy behaviors were identified in these countries. CONCLUSIONS: An assessment of total healthfulness of lifestyles and a better understanding of lifestyle patterns across countries using the LI can provide practical guidance to developing and targeting public health promotion activities to improve global public health.

The Diet Quality Index-International (DQI-I) provides an effective tool for cross-national comparison of diet quality as illustrated by China and the United States.

A composite measure of diet has been preferred to an index of a single nutrient or food in the area of dietary assessment. However, the lack of such a tool for cross-national comparisons has restricted the ability to compare diet quality between countries using an overall measure of diet. In this study, we created a tool called the Diet Quality Index-International (DQI-I) for global monitoring and exploration of diet quality across countries. The major categories of the index components are variety, adequacy, moderation and overall balance. Using the tool, this research presents a cross-national comparison of diet quality between China and the United States, incorporating comparable national in-depth diet data. The mean of the DQI-I score was slightly higher in China than in the United States. By major categories of the DQI-I, dietary variety was better achieved in the U.S. diet; moderation and overall balance of intakes were better accomplished in China. The DQI-I was successful in capturing variability in intakes of food and nutrients in both countries. Some distinct patterns of poor quality diet in each country were also identified. As demonstrated in this study, the DQI-I provides an effective means of cross-national comparative work for global understanding of diet quality. Furthermore, the dietary problem areas identified by the DQI-I may be useful in guiding the development of programs to improve public health.

The unique aspects of the nutrition transition in South Korea: the retention of healthful elements in their traditional diet.

OBJECTIVE: The purposes of this paper are to describe the unique aspects of the nutrition transition in South Korea, including trends in food consumption and obesity, patterns of morbidity and mortality; to focus on efforts to maintain the traditional diet in the midst of rapid economic growth and the introduction of Western culture; and to provide insights for other countries. DESIGN: We analysed secondary dietary intake, anthropometric, morbidity and mortality data from published reports and articles. RESULTS: In South Korea, the level and rate of increase in fat intake have remained very low, whereas vegetable intake has been high and fruit intake has increased greatly. South Korea also has a relatively low prevalence of obesity compared with other Asian countries. The traditional Korean diet is a low-fat and high-vegetable diet. Therefore, the government and nutrition specialists have been initiating numerous efforts to advertise and teach the public that the traditional diet is a healthy diet. They are also working on revival of the traditional diet using an approach that is acceptable to contemporary Koreans. CONCLUSIONS: The nutrition transition in South Korea is unique. A range of government, nutrition specialists and some private organisation efforts has worked to retain healthful elements of the traditional diet in South Korea. The continued low level of total fat in the overall diet and the high intake of fruits and vegetables bode well for South Korea.