Improved Hole Transport by p-InxGa1-xN Layer in Multiple Quantum Wells of Visible LEDs

Studied is the effect of indium (In) mole fraction in p-InxGa(1-x)N: Mg layers with 0 <= x(In) <= 0.035 on hole injection and transport behaviors in InGaN/GaN multiple quantum wells (MQWs) using dual-wavelength and triple-wavelength active regions. Electro-optical characteristics of light-emitting diodes containing p-layers with different In content and with silicon doping in selected QW barriers (QWBs) are compared to evaluate hole transport in the active region. The results show that enhanced hole transport and corresponding more uniform distribution of holes across the MQW region are achieved by increasing x(In) in the p-InxGa1-xN:Mg layer, possibly due to modification in energy of holes by a potential barrier between the p-InGaN and GaN QWB

Latina Mothers’ Perceptions of Healthcare Professional Weight Assessments of Preschool-Aged Children

To understand Latina mothers’ definitions of health and obesity in their children and perceptions of physician weight assessments. 24 low-income Spanish speaking Mexican mothers of children ages 2–5 years were recruited to participate in 4 focus groups. Half of the mothers had overweight or obese children and half had healthy weight children. Focus group comments were transcribed and analyzed using grounded theory. Themes and supporting comments were identified independently by 3 reviewers for triangulation. A fourth reader independently confirmed common themes. Mothers define health as a function of their child’s ability to play and engage in all aspects of life. Obesity was defined with declining physical abilities. Mothers state health care provider assessments help determine a child’s overweight status. Causative factors of obesity included family role-modeling and psycho-social stress, physical inactivity, and high-fat foods consumed outside the home. Controlling food intake was the primary approach to preventing and managing obesity but mothers described family conflict related to children’s eating habits. These findings held constant with mothers regardless of whether their children were overweight, obese, or at a healthy weight. Mothers utilize physical limitations and health care professional’s assessment of their child’s weight as indicators of an overweight status. These results highlight the importance of calculating and communicating body mass indices (BMI) for Latino children. Eliminating non-nutritive foods from the home, increasing physical activity, and involving family members in the discussion of health and weight maintenance are important strategies for the prevention and management of childhood obesity