Design, Methods, and Select Baseline Results from a School Nutrition Project for Adolescents in Bangladesh.

Background: The School Nutrition for Adolescents Project (SNAP) provided weekly iron and folic acid (WIFA) supplementation and menstrual hygiene management (MHM) support for girls; actions to improve water, sanitation, and hygiene (WASH) practices; and behavior change interventions to adolescents aged 10-19 y in 65 intervention schools in 2 districts of Bangladesh. Objectives: We aimed to describe the project design and select baseline results of students and school project implementers. Methods: Girls (n = 2244) and boys (n = 773) in 74 schools (clusters) and project implementers [headteachers (n = 74), teachers (n = 96), and student leaders (n = 91)] participated in a survey assessing nutrition, MHM, and WASH knowledge and experience. Hemoglobin, inflammation-adjusted ferritin, retinol-binding protein, and serum and RBC folate (RBCF) levels in girls were measured. School WASH infrastructure was observed and drinking water was tested for E. coli. Results: IFA and deworming tablet intake in the last 1 and 6 mo were 4% and 81% for girls and 1% and 86%, respectively. Applying the Minimum Dietary Diversity for Women (MDD-W) tool, most (63%-68%) girls and boys achieved minimum dietary diversity. Fewer adolescents (14%-52%) had ever heard of anemia, IFA tablets, or worm infestation than project implementers (47%-100%). Girls (35%) missed school during menstruation; 39% reported of ever leaving school due to unexpected menstruation. The micronutrient status and deficiency severity varied: anemia (25%), RBCF insufficiency (76%), risk of serum folate deficiency (10%), deficiencies of iron (9%), and vitamin A (3%). WASH in school sustainable development goal (SDG) indicators achievement varied: basic drinking water service (70%), basic sanitation service (42%), and basic hygiene service (3%); 59% of sampled drinking water access points complied with WHO E. coli standards. Conclusions: There is room for improvement of nutrition and health awareness, practices, micronutrient status, SDG basic WASH in-school services, and E coli contamination in school drinking water.This trial was registered in clinicaltrials.gov as NCT05455073.

Distributed feedback lasing based on a negative-index metamaterial waveguide.

This Letter lays the foundation of a new type of distributed feedback (DFB) laser whose optical feedback is due to the evanescent coupling between an active positive-index material (PIM) waveguide and a lossy negative-index metamaterial (NIM) waveguide. Active PIM-NIM coupled-mode equations are presented and solved to characterize the dispersion relation, resonant optical gain, and lasing. The photonic bandgap of this grating-less DFB laser does not depend on a Bragg wavenumber, but depends on the difference between the wavenumbers of the PIM and NIM waveguides; controlling this wavenumber difference allows for single-mode lasing and, ultimately, single-mode broadband lasing.