Polaron Formation in a Model Hamiltonian with Covalent Electron–Phonon Interactions

We have performed an exact diagonalization of a many body Hamiltonian that includes electron correlations and electron–phonon interactions. Electronic and phononic parameters entering in the Hamiltonian were chosen for the cluster O(4)—Cu–O(4) cluster in YBa₂Cu₃O₇. Electronic and phononic degrees of freedom are coupled through the bare electron hopping, as in the Su–Schieffer–Heeger (SSH) Hamiltonian [W. P. Su et al., Phys. Rev. Lett. 42, 1698 (1979); A. J. Heeger, Rev. Mod. Phys. 60, 781 (1988)]. Fixing all parameters entering in the model Hamiltonian, the electron–phonon coupling was varied in order to reproduce structural short-range distortions found in the z-axis direction for YBa₂Cu₃O₇. Although the inferred structural distortions are reproduced, we find that this type of coupling, unlike the electron–phonon coupling introduced in Peierls–Hubbard models, does not lead to excitations with polaronic energies and negative isotopic shifts typical of polaronic excitations.     

Automated design of degenerate codon libraries

Degenerate codon libraries are frequently used in protein engineering and evolution studies but are often limited to targeting a small number of positions to adequately limit the search space. To mitigate this, codon degeneracy can be limited using heuristics or previous knowledge of the targeted positions. To automate design of libraries given a set of amino acid sequences, an algorithm (LibDesign) was developed that generates a set of possible degenerate codon libraries, their resulting size, and their score relative to a user-defined scoring function. A gene library of a specified size can then be constructed that is representative of the given amino acid distribution or that includes specific sequences or combinations thereof. LibDesign provides a new tool for automated design of high-quality protein libraries that more effectively harness existing sequence-structure information derived from multiple sequence alignment or computational protein design data.     

Development of a new soybean variety for human consumption

During the past five years, the state of Guerrero has conducted an extensive research project to increase the protein content of local diets through development of soybean varieties that can be locally grown and easily assimilated into local diets. Guerrero is the location of Acapulco, host city for the World Conference on Soya Processing and Utilization. This article explains Guerrero’s project and the development of a new soy variety for human consumption. Conference registrants will have an opportunity to visit Guerrero’s soya fields. This report was prepared by Dr. Nuren M.S. Banafunzi, professor of plant breeding and head of the Agricultural Research Division at the Instituto Superior Agropecuario Autonómo del Estado de Guerrero (ISAAEG) and A. Man, professor and investigator of oil crops at the ISAAEG.     

A new soybean for human consumption in the tropics

Modern technology, especially in animal husbandry, has made remarkable progress. Even with all recent advances in animal reproduction (animal protein), we have not been able to keep pace with the rapid population growth rate in order to meet the demand for protein. This discrepancy in demand and supply for animal protein is even more severe in the tropics. The tradition of producing cereals and legumes to feed animals for conversion to meat (protein) is no longer feasible. Usually, animal proteins have complete profiles of essential amino acids, whereas those of plant origin are deficient in one or more of them. Soybean proteins, however, have about the same nutritional value as those of animals, and it is available for direct consumption by humans at a low cost. Because of the “off” or painty flavor, soybeans were not used for direct human consumption for a long time, except in areas such as China, Japan, Korea and Indonesia. Two major limiting factors for production of soybeans in the tropics are (a) lack of varieties adapted to low latitude and shorter days of the cool season, or to high altitude and low temperatures of the tropics, and (b) lack of varieties that are mild in beany flavor and appropriate for direct human consumption. A cross of the selected soybeans Kahala × Lee 68″ was made at Iguala ISAAEG Research Station. Several lines were selected in the F₄ generation with good agronomic and organoleptic properties. The resulting variety has been evaluated from 0 to 40° latitude and in the short growing season of low latitude; results were good. The ISAAEG-BM₂ variety of soybean is mild in flavor, and the heat treatment commonly applied to denature antinutritional factors is sufficient to completely eliminate the painty flavor. Details for the synthesis of ISAAEG-BM₂ variety and the recommended cultural practices for its maximal yield is discussed.     

Preliminary results for an adaptive family treatment for drug abuse in Hispanic youth.

A small randomized trial investigated a new family-based intervention for Hispanic adolescents who met DSM–IV criteria for substance abuse disorder. The Culturally Informed and Flexible Family-Based Treatment for Adolescents (CIFFTA) is a tailored/adaptive intervention that includes a flexible treatment manual and multiple treatment components. The study used an “add on” design to isolate the effects on substance abuse, behavior problems, and parenting practices attributable to the newly developed components. Twenty-eight Hispanic adolescents and their families were randomized either to the experimental treatment or to traditional family therapy (TFT) and were assessed at baseline and 8-month follow-up. Despite the small sample, results revealed statistically significant time × treatment effects on both self-reported drug use (marijuana + cocaine), F(1, 22) = 10.59, p     

Comparison between externally fired gas turbine and gasifier-gas turbine system for the olive oil industry

The olive oil industry generates during the extraction process several solid wastes as olive tree leaves and prunings, exhausted pomace and olive pits. These renewable wastes could be used for power and heat applications. The aim of this paper is to compare the performance of two small-scale CHP systems: a gasification- gas turbine system and an EFGT (externally fired gas turbine system). For this reason, several parameters have been calculated: generated heat and power, electric and overall efficiencies, biomass consumption, exergy efficiency, optimum pressure ratio, etc. These systems provide 30 kW_e and about 60kW_th. Simulation results show that the electrical and overall efficiencies achieved in EFGT system (19.1% and 59.3%, respectively) are significantly higher than those obtained in the gasification plant (12.3% and 45.4%). The proposed CHP systems have been modeled using Cycle-Tempo^® software.     

Phytochemical characterisation for industrial use of pomegranate (Punica granatum L.) cultivars grown in Spain

BACKGROUND: The study of 15 pomegranate cultivars was carried out in order to demonstrate the wide diversity among the quality of Spanish pomegranates, and compared to ‘Wonderful’ cultivars, which are used worldwide for industrial purposes. Juice yield, quality parameters, organic acids and sugars, colour, vitamin C, ellagic acid, punicalagins, anthocyanins, total phenolic content, antioxidant capacity, and sensory properties were measured. RESULTS: A considerable variation was found between ‘Wonderful’ and pomegranates of Spanish origin, according to both cluster analysis and principal component analysis. ‘Wonderful’ juices displayed large antioxidant activity and a polyphenol content with very high acidity. In contrast, ‘Mollar de Elche’ showed fewer anthocyanins although it had very superior organoleptical properties. In addition to a high content in ellagitannins, ‘Valenciana’ juices had exclusive colour parameters. CONCLUSION: These useful results can be employed by the juice processing industry to select those properties more interesting for the development of pomegranate juices that are organoleptically attractive and rich in bioactive compounds. Copyright © 2011 Society of Chemical Industry