Highly efficient four-wave mixing (FWM) and six-wave mixing (SWM) processes can coexist in a four-level Y-type atomic system due to atomic coherence. The simultaneously opened dual electromagnetically induced transparency windows in this four-level atomic system allow observation of these two nonlinear optical processes at the same time, which enables detailed studies of the interplay between the FWM and SWM processes. Three-photon and five-photon destructive interferences are also observed.

An electromagnetically induced absorption grating is formed in a three-level atomic vapor under the condition of electromagnetically induced transparency in which the strong coupling beam is replaced by a standing wave. The transmission and reflection behaviors of the weak probe beam are greatly modified at certain frequencies near the two-photon resonance. An all-optical two-port signal router-all-optical switch is demonstrated.

No abstract

Weaned British x continental crossbred steers (n = 108, 7 to 8 mo of age) of medium or large frame were used in a replicated experiment with a 2 x 4 factorial arrangement of treatments over 2 yr. Management regimens consisted of backgrounding for 150 d and finishing for 0, 30, 60, and 90 d. Carcass data were collected, and samples from the longissimus muscle were analyzed for long-chain fatty acids, cholesterol, and the percentage of fat. Duration of finishing was a source of variation for hot carcass weight, marbling, percentage of kidney, pelvic, and heart fat, fat thickness, yield and quality grades, cooking loss, flavor intensity, and stearic, oleic, and linolenic acids (P < .05). Myristic, palmitic, and margaric acids were negatively correlated (P < .05) with juiciness and with "cowy" and "painty" taste characteristics. Frame score did not influence long-chain fatty acids; however, there was a relationship between long-chain fatty acids and management regimen. Results suggest that feeding steers a finishing diet up to 90 d after backgrounding for 150 d has a positive influence on carcass characteristics without affecting cholesterol.

No abstract