Advances in Electrochemical Nitric Oxide Exhaust Gas Sensors

The role of porosity on impedancemetric NOx sensing is discussed for sensors composed of a porous yttria-stabilized zirconia (YSZ) electrolyte and dense Au electrodes. NOx sensors considered here were fabricated at firing temperatures of 950–1200°C, which established a range of electrolyte microstructures where the porosity ranged from approximately 50% to 44%. Analysis of the electrical response of the NOx sensors indicated that sensors fired at 1050°C resulting in an electrolyte porosity of 46% demonstrated higher NOx sensitivity based on the operating conditions studied. The impedance of the sensors demonstrated a strong dependence on the electrolyte porosity. The activation energy of the sensors, which ranged from 109.2 to 81.1 kJ/mol, decreased with decreasing electrolyte porosity. Sensors with an electrolyte porosity ≥46% were limited by dissociated adsorption, whereas gas diffusion was rate limiting for sensors with an electrolyte porosity <46%. The impedancemetric response of the porous sensors to NO concentrations ≤10 ppm was distinguishable at operating frequencies as high as 40 Hz, thereby suggesting rapid sensing capabilities. Overall, the microstructure of the sensors composed of a YSZ electrolyte with 46% porosity promoted a strong, rapid, and highly sensitive response to NOx

Managing H2O Cross‐Sensitivity Using Composite Electrolyte NOx Sensors

NOx sensors composed of partially stabilized zirconia (PSZ), fully stabilized zirconia (FSZ), and PSZ–FSZ composite electrolytes were investigated using impedance spectroscopy under dry and humidified gas conditions. The impedance data were used to interpret the electrochemical behavior of the various sensors as the water concentration in the gas stream varied. The sensors were operated in the presence of 0–100 ppm NO with 1–18% O2 and 3–10% H2O with N2 as the balance gas. The operating temperature of the sensors ranged from 600 to 700°C. The impedance response for sensors containing ≥ 50 vol% PSZ slightly decreased under humidified gas conditions, in comparison to dry gas conditions; whereas, a significant increase in impedance occurred for sensor largely containing FSZ. This indicated water cross-sensitivity was substantial at FSZ-based sensors. The microstructural properties, NOx sensitivity, oxygen partial pressure and temperature dependence, as well as the response time of the sensors composed of the various electrolytes were characterized in order to interpret the electrochemical response with respect to water cross‐sensitivity. Analysis of the data indicated that sensors composed of a PSZ–FSZ composite electrolyte with 50 vol% PSZ were more suitable for detecting NOx while limiting water cross‐sensitivity

Influencing healthful food choices in school and home environments: results from the TEENS study.

Background. The purpose of this research is to examine the effects of an intervention designed to increase the availability of fruits, vegetables and lower fat foods in homes and schools. This research is part of the TEENS study, a school-based intervention study. Methods. Sixteen schools in Minnesota were recruited to be in the study, and approximately 3600 middle school students in the eight intervention schools were exposed to a multi-component intervention. The TEENS intervention included classroom-based curricula, family newsletters, and changes in the school food environment including increasing more healthful options on a la carte and on the school lunch line. In addition to student-level outcomes, changes in availability of fruits, vegetables, and lower fat snacks in home and school environments were evaluated. The TEENS study was conducted from 1997 to 2000. Results. Parents of students in intervention schools reported making healthier choices when grocery shopping as compared to parents of students in control schools (P = 0.01). No intervention effects were evident from a home food inventory. Compared to control schools, intervention schools offered (P = 0.04) and sold (P = 0.07) a higher proportion of healthier foods on a la carte, but no effects were seen for fruit and vegetables sales as part of the regular meal pattern lunch. Conclusion. Our results show mixed results for positively influencing adolescents\u27 school and home environments

Developing a School Functioning Index for Middle Schools

Despite widespread recognition of schools\u27 role in the healthy development of youth, surprisingly little research has examined the relationships between schools\u27 overall functioning and the health‐related behavior of students. School functioning could become an important predictor of students\u27 health‐related behavior and may be amenable to intervention. This paper describes the development and testing of the School Functioning Index (SFI) as a first step in investigating this question. The index was developed for use with middle schools and conceived as a predictor of students\u27 violent behavior, with the potential for extending research applications to additional health and social behaviors. Using social cognitive theory, social ecological theory, and social disorganization theory as guides, three domains were identified to operationalize school functioning and identify candidate SFI items: 1) resources available to the school and students; 2) stability of the school population; and 3) the schools\u27 performance as a socializing agent for students. Data for candidate SFI items were collected from public archives and directly from 16 middle schools participating in a school‐based dietary intervention study. Data collection from schools, particularly concerning student aggressive behavior and disciplinary actions, presented challenges. The final SFI comprised nine items and demonstrated good internal consistency and variability. The SFI was modestly correlated in expected directions with violence and other health behaviors. This work supports the feasibility of combining multiple school‐level indicators to create a measure of overall school functioning. Further investigation of validity and more acceptable data collection methods are warranted

Henry J. Kaiser Family Foundation; National Alliance of State and Territorial AIDS Directors - National ADAP Monitoring Project Annual Report

Based on a survey of AIDS Drug Assistance Programs (ADAPs), which provide prescription drugs to low-income, uninsured, and underinsured HIV/AIDS patients, provides an overview of ADAPs' operations, developments, challenges, and policy and program changes

Puberty timing associated with diabetes, cardiovascular disease and also diverse health outcomes in men and women: the UK Biobank study.

Early puberty timing is associated with higher risks for type 2 diabetes (T2D) and cardiovascular disease in women and therefore represents a potential target for early preventive interventions. We characterised the range of diseases and other adverse health outcomes associated with early or late puberty timing in men and women in the very large UK Biobank study. Recalled puberty timing and past/current diseases were self-reported by questionnaire. We limited analyses to individuals of White ethnicity (250,037 women; 197,714 men) and to disease outcomes with at least 500 cases (~ 0.2% prevalence) and we applied stringent correction for multiple testing (corrected threshold P < 7.48 × 10(-5)). In models adjusted for socioeconomic position and adiposity/body composition variables, both in women and men separately, earlier puberty timing was associated with higher risks for angina, hypertension and T2D. Furthermore, compared to the median/average group, earlier or later puberty timing in women or men was associated with higher risks for 48 adverse outcomes, across a range of cancers, cardio-metabolic, gynaecological/obstetric, gastrointestinal, musculoskeletal, and neuro-cognitive categories. Notably, both early and late menarche were associated with higher risks for early natural menopause in women. Puberty timing in both men and women appears to have a profound impact on later health.This research has been conducted using the UK Biobank Resource. This work was supported by the Medical Research Council [Unit Programme number MC_UU_12015/2].This is the final version of the article. It first appeared from NPG via http://dx.doi.org/10.1038/srep1120

Are Differences in Exposure to a Multicomponent School-Based Intervention Associated With Varying Dietary Outcomes in Adolescents?

Multicomponent interventions are recommended for health behavior change among adolescents. However, it is difficult to disentangle the effects of multiple intervention components. This article reports outcomes associated with varying levels of exposure to a school-based nutrition intervention, Teens Eating for Energy and Nutrition at School (TEENS). Four incremental exposureswere possible: (1) control group, (2) school environment interventions only, (3) classroom plus environment interventions, and (4) peer leaders plus classroom plus environment interventions. Patterns suggesting dose response were observed, with peer leaders reporting the largest increases in fruit, vegetable, and lower fat food consumption. Students exposed to classroom plus environment interventions also improved, whereas students exposed only to school environment interventions showed trends toward choosing lower fat foods and declining fruit intake and no change in vegetable intake. Control students’ choices remained stable. Future studies may investigate mechanisms for peer leaders’ changes, maximizing curriculum effectiveness, and improving environmental interventions

Predictors of Violent Behavior in an Early Adolescent Cohort: Similarities and Differences Across Genders

The authors assessed a cohort of 2,335 students from the Minneapolis, Minnesota, area to identify predictors of violent behavior and to determine whether the predictors varied by gender. The sample was 76% White; boys and girls were equally represented. The majority lived with two parents. A measure of violent behavior collected at the end of the eighth-grade year (2000) was entered into Poisson regression against baseline data collected at the beginning of the seventh-grade year (1998). Predictors of violent behavior influencing both boys and girls included depressive symptoms, perceived invulnerability to negative future events, paternal nonauthoritative behavior, and drinking alcohol. Additional predictors of violent behavior specific to girls included both risk and protective factors