City-As-School: Internship-based Learning in New York City Public Schools

Paints a portrait of a high school with experiential learning at its core; at City-As-School in New York City, internships take the place of many classroom-based courses

Fermi surface, possible unconventional fermions, and unusually robust resistive critical fields in the chiral-structured superconductor AuBe

The noncentrosymmetric superconductor (NCS) AuBe is investigated using a variety of thermodynamic and resistive probes in magnetic fields of up to 65~T and temperatures down to 0.3~K. Despite the polycrystalline nature of the samples, the observation of a complex series of de Haas-van Alphen (dHvA) oscillations has allowed the calculated bandstructure for AuBe to be validated. This permits a variety of BCS parameters describing the superconductivity to be estimated, despite the complexity of the measured Fermi surface. In addition, AuBe displays a nonstandard field dependence of the phase of dHvA oscillations associated with a band thought to host unconventional fermions in this chiral lattice. This result demonstrates the power of the dHvA effect to establish the properties of a single band despite the presence of other electronic bands with a larger density of states, even in polycrystalline samples. In common with several other NCSs, we find that the resistive upper critical field exceeds that measured by heat capacity and magnetization by a considerable factor. We suggest that our data exclude mechanisms for such an effect associated with disorder, implying that topologically protected superconducting surface states may be involved

Investigation of constitutive relationship and dynamic recrystallization behavior of 22MnB5 during hot deformation

In order to analyze the softening behavior of 22MnB5 steel and further predict the constitutive relationship during hot sheet metal forming, a series of isothermal hot compression tests were conducted at the temperature range of 800–950 °C and strain rate range of 0.01–0.8 s−1 on BAEHR 805 A/D thermo-mechanical simulator system. Based on the friction corrected flow curves, the characteristic strain and stress of dynamic recrystallization (DRX) were derived from the Kocks-Mecking plots and expressed as a function of Zener-Hollomon parameter. Moreover, a physical constitutive model considering work hardening (WH), dynamic recovery (DRV) and DRX as well as corresponding JMAK-type DRX kinetics were developed. The results showed that the established physical equations can accurately predict the flow behavior with a correlation coefficient of 0.997 and average absolute relative error of 3.89%. Optical observation of the microstructure after hot compression revealed that the established DRX kinetics accurately reflects the reality, and then a Zener-Hollomon parameter dependent dynamic recrystallized grain size model was developed. Furthermore, EBSD analysis was carried out to study the effect of deformation conditions on martensite morphology and the results show that a lower temperature and higher strain rate lead to a finer martensite packet while the martensite block width becomes larger under the higher strain rate

Psychosocial Correlates of Physical Activity and Sedentary Leisure Habits in Young Adolescents: The Teens Eating for Energy and Nutrition at School Study

BACKGROUND: Low levels of physical activity (PA) and highly sedentary leisure habits (SLH) in youth may establish behavioral patterns that will predispose youth to increased chronic disease risk in adulthood. The purpose of this paper was to examine associations of demographic and psychosocial factors with self-reported PA and SLH in young adolescents. METHODS: A general linear mixed model predicted self-reported PA and SLH in the spring from demographic and psychosocial variables measured the previous fall in 3798 seventh grade students. RESULTS: PA and SLH differed by race, with Caucasian students reporting among the highest PA and lowest SLH. Perceptions of higher academic rank or expectations predicted higher PA and lower SLH. Depressive symptomatology predicted higher SLH scores but not PA. Higher self-reported value of health, appearance, and achievement predicted higher PA and lower SLH in girls. Girls who reported that their mothers had an authoritative parenting style also reported higher PA and lower SLH. CONCLUSIONS: Determinants of PA and SLH appear to differ from each other, particularly in boys. Development of effective programs to increase PA and/or decrease SLH in young adolescents should be based on a clear understanding of the determinants of these behaviors

Predicting Adolescents’ Intake of Fruits and Vegetables

Objective To explore potential predictors of adolescent fruit and vegetable intake by expanding on current theory and drawing from other adolescent research. Design This research reports on the baseline and interim data from a school-based intervention study. Data were collected through surveys administered to students at the beginning and end of their 7th-grade year. Setting The students attended 16 public schools in Minnesota. Participants Data were collected on 3878 students; approximately half were female and 67% were white. All students in the 7th-grade cohort were invited to participate in the surveys and over 94% completed both surveys. Variables Measured Our dependent variable, fruit and vegetable intake, was assessed by a validated fruit and vegetable food frequency scale. Predictive factors assessed included parenting style, spirituality/religiosity, depressive symptoms, and other commonly assessed predictors. Analysis Generalized linear mixed model regression. Omnibus test of association using P \u3c .05 is reported. Results Subjective norms, barriers, knowledge, usual food choice, parenting style, spirituality /religiosity, and depressive symptoms were statistically significant predictors of intake. The model explained about 31% of the variance in fruit and vegetable consumption. Conclusions and Implications To better understand adolescents\u27 fruit and vegetable intake, we must explore novel predictors. Our results need to be replicated, and more exploratory research in this field is needed

School-Based Approaches to Affect Adolescents’ Diets: Results From the TEENS Study

This article reports on the outcomes of the Teens Eating for Energy and Nutrition at School (TEENS) study, a 2-year intervention study conducted in 16 middle schools with a goal of increasing students’ intakes of fruits, vegetables, and lower-fat foods. Despite positive interim results for students randomized to intervention schools, the positive effects of the intervention were not seen for the primary outcomes at the end of the 2nd year. Positive effects were seen only for a food choice score (suggesting that the students usually choose lower versus higher fat foods) and not for measures of food intake. Future studies may need to take a step back toward more controlled efficacy studies in working with this age group. In addition, future work may consider the use of peer leaders, more intensive teacher training, ongoing formative assessment, and the testing of more powerful environmental change intervention strategies