Subwavelength anti-diffracting beams propagating over more than 1,000 Rayleigh lengths

Propagating light beams with widths down to and below the optical wavelength require bulky large-aperture lenses and remain focused only for micrometric distances. Here, we report the observation of light beams that violate this localization/depth- of-focus law by shrinking as they propagate, allowing resolution to be maintained and increased over macroscopic propagation lengths. In nanodisordered ferroelectrics we observe a non-paraxial propagation of a sub-micrometre-sized beam for over 1,000 diffraction lengths, the narrowest visible beam reported to date. This unprecedented effect is caused by the nonlinear response of a dipolar glass, which transforms the leading opticalwave equation into a Klein-Gordon-type equation that describes a massive particle field. Our findings open the way to high-resolution optics over large depths of focus, and a route to merging bulk optics into nanodevices

Prevalence of overweight in children and adolescents with attention deficit hyperactivity disorder and autism spectrum disorders: a chart review

BACKGROUND: The condition of obesity has become a significant public health problem in the United States. In children and adolescents, the prevalence of overweight has tripled in the last 20 years, with approximately 16.0% of children ages 6–19, and 10.3% of 2–5 year olds being considered overweight. Considerable research is underway to understand obesity in the general pediatric population, however little research is available on the prevalence of obesity in children with developmental disorders. The purpose of our study was to determine the prevalence of overweight among a clinical population of children diagnosed with attention deficit hyperactivity disorder (ADHD) and autism spectrum disorders (ASD). METHODS: Retrospective chart review of 140 charts of children ages 3–18 years seen between 1992 and 2003 at a tertiary care clinic that specializes in the evaluation and treatment of children with developmental, behavioral, and cognitive disorders. Diagnostic, medical, and demographic information was extracted from the charts. Primary diagnoses of either ADHD or ASD were recorded, as was information on race/ethnicity, age, gender, height, and weight. Information was also collected on medications that the child was taking. Body mass index (BMI) was calculated from measures of height and weight recorded in the child's chart. The Center for Disease Control's BMI growth reference was used to determine an age- and gender-specific BMI z-score for the children. RESULTS: The prevalence of at-risk-for-overweight (BMI >85th%ile) and overweight (BMI > 95th%ile) was 29% and 17.3% respectively in children with ADHD. Although the prevalence appeared highest in the 2–5 year old group (42.9%ile), differences among age groups were not statistically significant. Prevalence did not differ between boys and girls or across age groups (all p > 0.05). For children with ASD, the overall prevalence of at-risk-for-overweight was 35.7% and prevalence of overweight was 19%. CONCLUSION: When compared to an age-matched reference population (NHANES 1999–2002), our estimates indicate that children with ADHD and with ASD have a prevalence of overweight that is similar to children in the general population

The Hyperactivity/Inattention Subscale of the Strengths and Difficulties Questionnaire Predicts Short- and Long-Term Weight Loss in Overweight Children and Adolescents Treated as Outpatients

Objective: The success of treatment for pediatric obesity is variable and often unsatisfactory. This study elucidates the influence of inattention and hyperactivity/impulsivity on short- and long-term weight loss and maintenance after outpatient treatment. Methods: We included 8- to 16-year-old overweight and obese participants treated in 17 multidisciplinary outpatient treatment centers in a nationwide observational study. All treatment centers that reported long-term (1-year) follow-up weight data of at least 60% of the participants were included. At the beginning and end of treatment and at 1 year follow-up weight and height were measured at the center. Inattention and hyperactivity/impulsivity were assessed with the hyperactivity/inattention subscale (HI) of the parent-rated Strengths and Difficulty Questionnaire (SDQ). General linear models were used with the standard deviation scores of the BMI (BMI-SDS) as dependent variable and HI scores as main independent variable adjusting for age, sex, baseline BMI-SDS, and center. Results: 394 participants were included (57% female, age: 11.7± 2.0 years, baseline BMI-SDS 2.32 ±.46 kg/m2). HI scores were significantly associated with short- and long-term BMI-SDS (p < 0.0005), with higher baseline HI scores predicting less weight loss. Conclusions: Our results indicate that inattention and hyperactivity/impulsivity are linearly associated with reduced short- and long-term weight loss. Implications for treatment are discussed