Generation of arbitrarily directed split beams with a reflective metasurface.

We present a new, to the best of our knowledge, formalism in the design of metasurface beamsplitters with arbitrarily chosen split beam directions. This technique is based on the well-established array theory; in particular the Fourier transform method of array synthesis, to cast an obliquely incident plane wave to multiple designer-selected scattering directions. To show the efficacy of this approach, a beamsplitting metasurface reflector is designed and verified experimentally and numerically. The metasurface is fabricated by screen-printing patterns of metallic rectangular-shaped resonators of conductive ink onto a ground plane-backed substrate. The beamsplitting characteristics are quantified using a simple free-space transmit/receive horn system operating at 10.525 GHz. It is shown that the presented design technique accurately predicts the scattering properties of the fabricated metasurface and is a useful method for electromagnetic wave manipulation.

Angle-insensitive plasmonic nanorod metamaterial-based band-pass optical filters.

We demonstrate, experimentally and theoretically, a new class of angle-insensitive band-pass optical filters that utilize anisotropy of plasmonic nanorod metamaterials, in both ε ≃ -1 and epsilon-near-infinity regimes, to minimize dependence of optical path on the incident angle. The operating wavelength and bandwidth of the filter can be engineered by controlling the geometry of the metamaterial. Experimental results are in agreement with full wave numerical and analytical solutions of the Maxwell's equations. Theoretical simulations show that performance of the systems can be further improved by replacing metallic mirrors with dielectric stacks.

Intensive, Manual-based Intervention for Pediatric Feeding Disorders: Results From a Randomized Pilot Trial.

OBJECTIVES: The aim of this pilot study was to investigate feasibility and preliminary efficacy of an intensive, manual-based behavioral feeding intervention for children with chronic food refusal and dependence on enteral feeding or oral nutritional formula supplementation. METHODS: Twenty children ages 13 to 72 months (12 boys and 8 girls) meeting criteria for avoidant/restrictive food intake disorder were randomly assigned to receive treatment for 5 consecutive days in a day treatment program (n = 10) or waitlist (n = 10). A team of trained therapists implemented treatment under the guidance of a multidisciplinary team. Parent training was delivered to support generalization of treatment gains. We tracked parental attrition and attendance, as well as therapist fidelity. Primary outcome measures were bite acceptance, disruptions, and grams consumed during meals. RESULTS: Caregivers reported high satisfaction and acceptability of the intervention. Three participants (1 intervention; 2 waitlist) dropped out of the study before endpoint. Of the expected 140 treatment meals for the intervention group, 137 (97.8%) were actually attended. The intervention group showed significantly greater improvements (P < 0.05) on all primary outcome measures (d = 1.03-2.11) compared with waitlist (d = -1.13-0.24). A 1-month follow-up suggested stability in treatment gains. CONCLUSIONS: Results from this pilot study corroborate evidence from single-subject and nonrandomized studies on the positive effects of behavioral intervention. Findings support the feasibility and preliminary efficacy of this manual-based approach to intervention. These results warrant a large-scale randomized trial to test the safety and efficacy of this intervention.

Looking into meta-atoms of plasmonic nanowire metamaterial.

Nanowire-based plasmonic metamaterials exhibit many intriguing properties related to the hyperbolic dispersion, negative refraction, epsilon-near-zero behavior, strong Purcell effect, and nonlinearities. We have experimentally and numerically studied the electromagnetic modes of individual nanowires (meta-atoms) forming the metamaterial. High-resolution, scattering-type near-field optical microscopy has been used to visualize the intensity and phase of the modes. Numerical and analytical modeling of the mode structure is in agreement with the experimental observations and indicates the presence of the nonlocal response associated with cylindrical surface plasmons of nanowires.

Strong through-space two-halide magnetic exchange of -234 K in (2,5-dimethylpyrazine)copper(II) bromide.

An unprecedented antiferromagnetic exchange of -234 K in Cu(2,5-dimethylpyrazine)Br(2) is shown experimentally and theoretically to propagate via through-space interactions between Br ions rather than through-bond interactions.

A content analysis of the prevalence and portrayal of sexual activity in adolescent literature.

Most research on sexual content in the media has focused on visual images such as those in TV, film, advertisements, and magazines. However, researchers have largely overlooked sexual content in novels. The popularity of novels and the potential for such literature to educate teens on sexual behaviors merits a closer examination into the sexual messages contained in popular adolescent literature. This study content analyzes the top 40 novels targeting adolescents. Results show that adolescent novels are replete with sex-related information, especially in novels targeted to girls. These sexual behaviors range from passionate kissing and romantic ideation to sexual intercourse. Over one third of the instances focus on references to sex, suggestive innuendos, or sexual descriptions; and an additional one third of sexual behavior involved sexual affection in the form of passionate kissing, intimate touching, and playful sexual behavior. Across the 40 books, there were 56 instances of sexual intercourse, most of which involved unmarried couples (94%); and many were in non-committal relationships. Moreover, sexual material rarely dealt with issues of abstinence, safe sex practices, and the health risks associated with sex.