Fissure Characterization of Rice Kernels Using Video Microscopy

Fissures are fractures of a rice kernel that can be created during the drying and tempering process. They cause tremendous postharvest losses in milling yield. Understanding why and how rice kernels fissure will lead to optimal drying and tempering operations. This information could also provide input to plant breeders for producing rice cultivars that are more resistant to fissuring. Rice kernels were dried using various air conditions in a controlled environment chamber. The kernels were viewed by video microscopy to observe the occurrence of fissures. A videocassette recorder recorded the images for a 24-hour period after the drying process. The tapes were reviewed to reveal characteristics of the fissures. The rice cultivars used in this experiment were ‘Bengal’, ‘Cypress’, and ‘Drew’. The tests showed that Cypress kernels were more resistant to fissuring than were the other two cultivars. The recorded images from the microscopy chamber showed that fissures begin from the inside of the kernel. Also, fissures were observed to form almost instantaneously

Effects of Macromolecular Crowding on Ferredoxin and Ferredoxin-NADP+ Reductase Kinetics

Macromolecular crowding refers to the intrinsic occurrence of high concentrations of macromolecules found within cells, which may alter biomolecular properties of other macromolecules. Simulating these environments in vitro should enable a more accurate understanding of these modifications. We have employed in vitro studies to specifically examine the effects of macromolecular crowding on biological redox reactions. The iron-sulfur protein ferredoxin (Fdx) and the FAD-containing flavoprotein ferredoxin-NADP+ reductase (FNR), from Spinacea oleracea, were utilized as a model electron transfer system. Utilizing NADPH as a reductant, the Fdx-FNR complex reduces mammalian cytochrome c as a surrogate electron acceptor. Reduction of the heme moiety of cytochrome c is monitored at 550nm. We have focused our attention primarily on bovine serum albumin (BSA) as a model macromolecular crowding agent at concentrations up to 20%. Under these conditions, the rate of cytochrome c reduction displays hyperbolic kinetics with respect to Fdx concentration. Initial experiments utilizing 10% BSA resulted in a 70% reduction in the electron transfer rate, whereas lower BSA concentrations showed evidence of stimulatory effects. These results suggest crowding effects on reduction kinetics in this system may be nonlinear. We will report the Fdx concentration dependence of cytochrome c reduction rates as a function of BSA concentration. In related experiments, we have also examined viscosity effects with this system to determine the effects of changes in diffusion rates on the kinetics of electron transfer

P02.01. A dietary approach for treating dyslipidemia and hyperglycemia

Purpose: Elevated LDL cholesterol and impaired fasting glucose are significant risk factors for cardiovascular disease; the most prevalent cause of mortality in the USA. Many dietary approaches have been examined to help combat these medical problems. Each type of diet typically places a particular emphasis on the relative proportions of the three macronutrients; fat, carbohydrate and protein

Evaluation of mechanical properties of composite materials made from recycled fly ash and polymers

In this article evaluates the mechanical properties of composite materials based on fly ash and Coal-fired power plants Termozipa combined with the stretch film (stretch film), linear low density polyethylene post-consumer and partially thermoplastic polymer, crystalline Industrial post. Mixtures were obtained by varying the content of fly ash, 0 to 50 % by weight in each of the three polymeric materials, within a machine type Brabender mixer. The mechanical properties evaluated were: tensile strength, Shore D hardness, and energy absorption, the results obtained indicate that in all cases, as fly ash is added, the mechanical properties increase.En el presente artículo se evalúan las propiedades mecánicas de los materiales compuestos basados en cenizas volantes de carbón de la central termoeléctrica de Termozipa combinadas con los película extensible (Stretch film), polietilenos de baja densidad lineal de pos-consumo y polímero termoplástico parcialmente cristalino pos- industrial. Se obtuvieron mezclas variando el contenido de cenizas volantes de 0 a 50 % en peso en cada uno de los tres materiales poliméricos, dentro de una máquina mezcladora tipo Brabender. Las propiedades mecánicas evaluadas fueron: resistencia a la tracción, dureza Shore D, y absorción de energía. Los resultados obtenidos indican que en todos los casos a medida que se agrega ceniza volante las propiedades mecánicas aumentan

Radiation Damping in the Photoionization of Fe^{14+}

A theoretical investigation of photoabsorption and photoionization of Fe^{14+} extending beyond an earlier frame transformation R-matrix implementation is performed using a fully-correlated, Breit-Pauli R-matrix formulation including both fine-structure splitting of strongly-bound resonances and radiation damping. The radiation damping of $2p\rightarrow nd$ resonances gives rise to a resonant photoionization cross section that is significantly lower than the total photoabsorption cross section. Furthermore, the radiation-damped photoionization cross section is found to be in good agreement with recent experimental results once a global shift in energy of $\approx -3.5$ eV is applied. These findings have important implications. Firstly, the presently available synchrotron experimental data are applicable only to photoionization processes and not to photoabsorption; the latter is required in opacity calculations. Secondly, our computed cross section, for which the L-shell ionization threshold is aligned with the NIST value, shows a series of $2p \rightarrow nd$ Rydberg resonances that are uniformly 3-4 eV higher in energy than the corresponding experimental profiles, indicating that the L-shell threshold energy values currently recommended by NIST are likely in error.Comment: 4 pages, 1 figures, and 2 table

Atomic Processes in Planetary Nebulae and H II Regions

Spectroscopic studies of Planetary Nebulae (PNe) and H {\sc ii} regions have driven much development in atomic physics. In the last few years the combination of a generation of powerful observatories, the development of ever more sophisticated spectral modeling codes, and large efforts on mass production of high quality atomic data have led to important progress in our understanding of the atomic spectra of such astronomical objects. In this paper I review such progress, including evaluations of atomic data by comparisons with nebular spectra, detection of spectral lines from most iron-peak elements and n-capture elements, observations of hyperfine emission lines and analysis of isotopic abundances, fluorescent processes, and new techniques for diagnosing physical conditions based on recombination spectra. The review is directed toward atomic physicists and spectroscopists trying to establish the current status of the atomic data and models and to know the main standing issues.Comment: 9 pages, 1 figur

Propiedades ópticas de peliculas Ldep con diferentes mezclas de aditivos.

In this article, different formulations of linear low density polyethylene (PEBD) mixed with 5 different types of additives were processed, the objective of which is to analyze the effect of the additives on the optical properties of PEBD films for crop protection directed primarily for constructions of greenhouses suitable for performance in tropical environments. The results of the ultra violet and visible region transmission show that the light transmission of the reference films is greater in the visible area than in films made with additive mixtures, due to the diffusive effect of some elements and the synergistic action of the additives decreasing the transmission of light in the ultra violet and visible area.En el presente artículo se procesaron diferentes formulaciones de polietileno lineal de baja densidad (PEBD) mezclado con 5 tipos de aditivos diferentes, cuyo objetivo es analizar el efecto de los aditivos en las propiedades ópticas de películas de PEBD de protección de cultivo dirigida fundamentalmente para construcciones de invernaderos adecuados para el desempeño en medios tropicales. Los resultados de la transmisión de la región ultra violeta y visible muestran que la transmisión de luz de las películas de referencia es mayor en la zona visible que en las películas fabricadas con mezclas de aditivos, debido al efecto difusivo de algunos elementos y a la acción sinérgica de los aditivos disminuyendo la transmisión de luz en la zona ultra violeta y visible