Spatiotemporal characterization of supercontinuum extending from the visible to the mid-infrared in a multimode graded-index optical fiber.

We experimentally demonstrate that pumping a graded-index multimode fiber with sub-ns pulses from a microchip Nd:YAG laser leads to spectrally flat supercontinuum generation with a uniform bell-shaped spatial beam profile extending from the visible to the mid-infrared at 2500 nm. We study the development of the supercontinuum along the multimode fiber by the cut-back method, which permits us to analyze the competition between the Kerr-induced geometric parametric instability and stimulated Raman scattering. We also performed a spectrally resolved temporal analysis of the supercontinuum emission.

Spatial Beam Self-Cleaning in Second-Harmonic Generation.

We experimentally demonstrate the spatial self-cleaning of a highly multimode optical beam, in the process of second-harmonic generation in a quadratic nonlinear potassium titanyl phosphate crystal. As the beam energy grows larger, the output beam from the crystal evolves from a highly speckled intensity pattern into a single, bell-shaped spot, sitting on a low energy background. We demonstrate that quadratic beam cleanup is accompanied by significant self-focusing of the fundamental beam, for both positive and negative signs of the linear phase mismatch close to the phase-matching condition.

The efficacy of Na-butyrate encapsulated in palm fat on performance of broilers infected with necrotic enteritis with gene expression analysis.

AIM: To study the efficacy of Na-butyrate encapsulated in palm fat on performance of broiler chickens experimentally infected with necrotic enteritis (NE) with the determination of its protective effect against the changes in the gene expression profiles and deoxyribonucleic acid (DNA) fragmentation. MATERIALS AND METHODS: A total of 800 one-day-old male Arbor Acres Plus broiler chickens were randomly allocated into four groups for 5 weeks. Na-butyrate was supplemented at dosages of 1 kg/ton for starter diet, 0.5 kg/ton for grower diet, and 0.25 kg/ton for finisher diet (presence or absence). Birds of groups 1 and 2 were inoculated by crop gavages with 4×10(8) CFU/ml/bird of Clostridium perfringens in phosphate buffered saline for 4 successive days, from 14 to 17 days of age to produce NE. RESULTS: Addition of Na-butyrate, encapsulated in palm fat, to ration of experimentally infected broilers with NE resulted in increased final body weight, at 35 days of age, reduced total feed consumption, improved feed conversion ratio, reduced cumulative mortality, and increased production number. There were increased intestinal diameter, intestinal length, and significantly increased the weight of bursa of Fabricius(BF) with higher hemagglutination inhibition titers against Newcastle disease (ND) vaccination versus untreated infected and untreated negative control birds. The results showed increased expression levels of alpha-toxin and glyceraldehyde-3-phosphate dehydrogenase in the bursa tissues of broilers infected with C. perfringens. However, the expression levels of these genes in broilers treated with Na-butyrate were similar to the non-infected control group. Supplementation of broilers with Na-butyrate increased the expression level of insulin-like growth factor-1 (IGF-1) and decreased the DNA fragmentation induced by C. perfringens. CONCLUSION: Na-butyrate significantly improved chicken broiler body weights, increased relative weights of BF, increased antibody titers against ND vaccination, numerically lowered mortality due to C. perfringens infection, increased the expression level of IGF-1, and decreased the DNA fragmentation induced by C. perfringens. Obtained results point out the effectiveness of Na-butyrate encapsulated in palm fat in improving the production performance variables, immune response, and intestinal morphology in experimentally induced NE as well as in non-infected chicken broilers.