Performance limits due to thermal transport in graphene single-photon bolometers

In high-sensitivity bolometers and calorimeters, the photon absorption often occurs at a finite distance from the temperature sensor to accommodate antennas or avoid the degradation of superconducting circuitry exposed to radiation. As a result, thermal propagation from the input to the temperature readout can critically affect detector performance. In this report we model the performance of a graphene bolometer, accounting for electronic thermal diffusion and dissipation via electron-phonon coupling at low temperatures in three regimes: clean, supercollision, and resonant scattering. Our results affirm the feasibility of a superconducting readout without Cooper-pair breaking by mid- and near-infrared photons, and provide a recipe for designing graphene absorbers for calorimetric single-photon detectors. We investigate the tradeoff between the input-readout distance and detector efficiency, and predict an intrinsic timing jitter of ~2.7 ps. Based on our result, we propose a spatial-mode-resolving photon detector to increase communication bandwidth

Stabilization of G-quadruplex in the BCL2 promoter region in double-stranded DNA by invading short PNAs

Numerous regulatory genes have G-rich regions that can potentially form quadruplex structures, possibly playing a role in transcription regulation. We studied a G-rich sequence in the BCL2 gene 176-bp upstream of the P1 promoter for G-quadruplex formation. Using circular dichroism (CD), thermal denaturation and dimethyl sulfate (DMS) footprinting, we found that a single-stranded oligonucleotide with the sequence of the BCL2 G-rich region forms a potassium-stabilized G-quadruplex. To study G-quadruplex formation in double-stranded DNA, the G-rich sequence of the BCL2 gene was inserted into plasmid DNA. We found that a G-quadruplex did not form in the insert at physiological conditions. To induce G-quadruplex formation, we used short peptide nucleic acids (PNAs) that bind to the complementary C-rich strand. We examined both short duplex-forming PNAs, complementary to the central part of the BCL2 gene, and triplex-forming bis-PNAs, complementary to sequences adjacent to the G-rich BCL2 region. Using a DMS protection assay, we demonstrated G-quadruplex formation within the G-rich sequence from the promoter region of the human BCL2 gene in plasmid DNA. Our results show that molecules binding the complementary C-strand facilitate G-quadruplex formation and introduce a new mode of PNA-mediated sequence-specific targeting

Food Group Preferences of Elementary School Children Participating in the National School Lunch Program

Purpose/Objectives The purpose of the study was to assess the food group preferences of second through fifth grade children based on ethnic background, gender, and grade. Food group preferences were determined by the amount of various food groups consumed in meals served as part of the National School Lunch Program at selected schools. Research indicates that greater consumption of food is directly proportional to preferences; the higher the preference, the greater the consumption. Methods A plate waste study was conducted in a culturally diverse city in four predominantly free and reduced lunch eligible elementary schools with a large Hispanic population (58%, 69%, 82%, and 82% of students). Over a 40 day period (10 days at each of the 4 schools), 5,400 plates were evaluated. Individual food items in the school lunch were measured before and after the meals were served. Food group intakes were determined by measuring the difference between the amount served and the amount remaining of each menu item after the meal was complete. Results Caucasian children were seen to have better consumption patterns than Hispanic children. The dairy, vegetable, and fruit food groups were better consumed by Caucasians than Hispanics (P \u3c0.05). Girls and second graders were seen to consume less of the school lunch foods than boys and older students (P \u3c0.05). The majority of children in all groups did not meet Food Guide Pyramid recommendations for the grains, fruits, vegetables, dairy, and meat food groups. Applications to Child Nutrition Professionals Since food preferences are the major determinant of consumption, poorer consumption patterns for Hispanic students may indicate a reduced preference for those foods being served through the school lunch menus. Child Nutrition Professionals need to consider what foods are nourishing, yet acceptable, for the specific population in their schools to help ensure that the children will consume the foods. This is especially critical in schools where the children are from lower socioeconomic families since the meals received at school may be their major nutrient source for the day

Nutrient analysis of school lunches and anthropometric measures in a private and public school in Chennai, India

School lunch programs have been implemented as a method to facilitate better learning environments for children. These programs bring together the importance of adequate nutrition for academic performance, growth and development. This study served to assess the impact of the School Lunch Program in India and observe measures related to nutrition adequacy and stunting in school aged children in Chennai, India. Dietary and anthropometric data were collected among students of ages 7 to 10 in a privately funded (n = 64) and a publicly funded school (n = 28). Bioelectrical Impedance Analysis was assessed for private school students. BMI for Age Z-scores for the private school (0.05 ± 1.36) (mean ± standard deviation) and public school (− 0.91 ± 2.01) were significantly different (p = 0.008). Additionally, 32% of public school students exhibited mild stunting, classified as Z-scores less than − 1. Total calories consumed during the private school lunch was 269 ± 112 and 463 ± 234 for the publically funded school. Analysis of nutritional parameters of meals suggest that adequacy was otherwise fair during this singular analysis but does not provide evidence to correlate body composition and long term implications of malnutrition with this study population. Additional longitudinal analysis is required to better assess these implications

School Lunch Quality Following Healthy, Hunger-Free Kids Act Implementation

Purpose/Objectives This study investigates the effect of meal component changes by the Healthy, Hunger-Free Kids Act of 2010 (HHFKA) on school lunch quality and consumption in elementary school students, grade 2-5 before and after the HHFKA guidelines were implemented in July 2012 using the Healthy Eating Index. Methods In Spring 2012, before implementation of meal standards mandated by the HHFKA, digital photographs were taken of second to fifth graders’ lunches in four HealthierUS School Challenge (HUSSC) participating elementary schools before and after the meals were consumed. In Spring 2013, after implementation of meal standards mandated by the HHFKA, digital photographs of lunches were again taken in the same schools before and after lunches were consumed. The photos were used to visually estimate the amounts of food items selected and consumed. Meals selected and consumed were scored using the Healthy Eating Index (HEI-2010). The HEI-2010 scores of the lunches in 2012 were compared to those in 2013. Results Results based upon 1,033 lunches (509 pre-HHFKA in Spring 2012 and 524 post-HHFKA in Spring 2013) revealed improved HEI-2010 scores (p\u3c 0.05) for both served (52.2 pre-HHFKA to 57.0 post- HHFKA) and consumed meals (49.8 pre-HHFKA to 53.2 post-HHFKA). Noteworthy component scores that improved included Empty Calories (served) from 14.1 to 15.3 (maximum score 20); Total Fruit (served) from 2.3 to 3.7 (maximum score 5); Total Fruit (consumed) from 2.3 to 3.4 (maximum score 5); and Sodium (served) from 4.6 to 5.3 (maximum score 10). Application to Child Nutrition Professionals The current study indicates that menus offered by child nutrition professionals in four schools in Washington improved the nutritional quality of lunches served and consumed post-HHFKA implementation

Beverage Selections and Impact on Healthy Eating Index Scores in Elementary Children’s Lunches From School and From Home

Purpose/Objectives The purposes of this study were to: 1) analyze beverage selections of elementary students consuming National School Lunch Program meals (NSLP) and lunches brought from home (LBFH), 2) compare overall meal quality (MQ) of NSLP and LBFH by food components using Healthy Eating Index 2010 (HEI-2010), and 3) investigate the impact of beverage selections on MQ. Methods Digital plate waste estimations were analyzed for 509 NSLP and 524 LBFH meals from 2nd-5th grade students in four elementary schools during the 2011-2012 academic year. Nutrient Data Software for Research (NDSR) was used to determine food groups and nutrients for calculations. Independent t-tests compared NSLP and LBFH meal components. Two one-way ANOVA tests compared HEI-2010 dietary component scores by the following beverage selections: 1% plain milk, non-fat flavored milk, 100% fruit juice, sugar-sweetened beverage (SSB), or water/no beverage. Results NSLP (90% non-fat flavored or 1% plain milk) and LBFH (75% water/none or SSB) varied widely in beverages selected. LBFH provided significantly (p \u3c 0.05) more Whole Grains (NSLP 2.8/5pts vs LBFH 4.7pts) and Seafood & Plant Proteins (NSLP 0.5/5pts vs LBFH 1.7pts) than NSLP. NLSP provided more Dairy (NSLP 9.3/10pts vs LBFH 4.7pts). NSLP scored higher in Total Protein, and reduced Empty Calories. Both meal origins indicated a need for improvement in Greens/Bean Vegetables and Seafood/Plant Proteins. Selection of 1% plain milk resulted in significantly higher HEI-2010 scores (NSLP served 55.7/100pts, consumed 53.9pts and LBFH, served 62.1, consumed 60.2). Applications for Child Nutrition Professionals Child nutrition professionals consistently provide nutritious beverages like 1% plain milk, non-fat flavored milk, and 100% juice in NSLP meals. A “milk only” line for children with LBFH may encourage milk consumption and improve HEI scores of LBFH. LBFH would benefit from elimination of sugar sweetened beverages (SSB). Increased nutrition education to teachers, staff, parents, and children on the effects of various beverages on dietary quality would be appropriate to further improve beverage selection and meal quality

School Lunch Before and After Implementation of the Healthy Hunger-Free Kids Act

Purpose/ObjectivesThis study compares the mean nutrients selected and consumed in National School Lunch Program (NSLP) meals before and after implementation of the new nutrition standards mandated by the Healthy Hunger-Free Kids Act of 2010 (HHFKA) in July 2012. Four elementary schools achieving HealthierUS Schools Challenge awards serving second through fifth grade students were selected to participate.MethodsIn Spring 2012, before implementation of meal standards mandated by the HHFKA, digital photographs of NSLP lunches were taken of second to fifth graders’ lunches in four elementary schools before and after the meals were consumed. In Spring 2013, after implementation of meal standards mandated by the HHFKA, digital photographs of lunch were again taken in the same schools before and after lunches were consumed. The photos were used to visually estimate the amounts of food items on trays and determine nutritional content of meals selected and consumed. The nutrition content of the lunches in 2012 was compared to those in 2013 by applying a one-way multiple analysis of variance (MANOVA) followed by post-hoc analyses using multiple t-tests to compare mean nutrient amounts.ResultsThe current study revealed significant improvements in both selected and consumed key nutrients when comparing meals before implementation of the HHFKA (2012) to the meals after implementation of the HHFKA (2013) nutrition standards. These included reductions in sodium and the percentage of calories from saturated fat and a significant increase in fiber. A reduction in calcium selected and consumed was also observed.Applications to Child Nutrition ProfessionalsThe current study indicates that child nutrition professionals are making positive changes in their menu selections to meet the requirements of the HHFKA. However, child nutrition professionals may need to evaluate menus for calcium and make modifications as needed to enhance calcium rich foods selected in NSLP meals

Lunches Selected and Consumed from the National School Lunch Program in Schools Designated as HealthierUS School Challenge Schools Are More Nutritious than Lunches Brought from Home

Purpose/ObjectiveThe purpose of this study was to compare the nutrient content of National School Lunch Program (NSLP) lunches and lunches brought from home (LBFH) lunches in elementary schools participating in the HealthierUS School Challenge (HUSSC). MethodsParticipants included students in grades 2-5 in four Washington state HUSSC elementary schools. Data were collected during the 2011-12 school year. A multiple analysis of variance (MANOVA) followed by post-hoc analyses of multiple t-tests was used to analyze nutrients provided and consumed by students to show differences between NSLP lunches and LBFH. Data were further separated by the child\u27s eligibility status for free and reduced price meals. A MANOVA test followed by post-hoc analyses using multiple t-tests compared differences in mean nutrient amounts between LBFH and NSLP lunches within these groups. The average percentages of NSLP lunches and LBFH meeting School Meal Initiative (SMI) guidelines were compared. ResultsA total of 1,085 lunches were evaluated including 547 NSLP meals from 344 students and 538 LBFH from 276 students. NSLP lunches provided significantly more protein, calcium, iron, cholesterol, sodium, and vitamin C compared to LBFH. Students with NSLP lunches consumed significantly more protein, calcium, iron, cholesterol, sodium, vitamin A, and vitamin C compared to students who had LBFH. Students eligible for free and reduced price (FRP) meals who ate LBFH brought and consumed more calories, fat, and saturated fat. Lunches brought from home were less likely to meet SMI guidelines in nearly all categories.Applications to the Child Nutrition ProfessionalsBased on the results from the current study, child nutrition professionals planned and prepared NSLP meals that met the current standards. As a result NSLP lunches were more nutritious than LBFH. While continuing efforts to improve the NSLP, the nutritional quality and content of LBFH should be more extensively studied. Nutrition education regarding LBFH is important for both parents and students. Further research is needed to determine factors affecting choice of LBFH food items