Wheat dough rheology and bread quality effected by Lactobacillus brevis preferment,dry sourdough and lactic acid addition

The influence of chemical and biological acidification on dough rheological properties and bread quality has been investigated. Two different flour types were used. Dough was chemically acidified with lactic acid. Two types of biologically acidified dough were prepared: dough with dry sourdough and with a Lactobacillus brevis preferment. Wheat dough rheological properties were investigated using the Farinograph, Extensograph and Amylograph. The baking response was also determined using standard baking tests. Addition of acidifiers resulted in firmer doughs with less stability, decreased extensibility and decreased gelatinisation maximum. The biological acidifiers increased the bread specific volume. Lactic acid addition had no influence on bread specific volume. In general, biological and chemical acidification decreased bread hardness. The addition of dry sourdough significantly decreased the lightness and increased the yellowness and redness of the bread crumb. The crust chroma, hue angle and brownness index were significantly changed by addition of acidifiers.     

Principal component analysis coupled with artificial neural networks-a combined technique classifying small molecular structures using a concatenated spectral database

In this paper we present several expert systems that predict the class identity of the modeled compounds, based on a preprocessed spectral database. The expert systems were built using Artificial Neural Networks (ANN) and are designed to predict if an unknown compound has the toxicological activity of amphetamines (stimulant and hallucinogen), or whether it is a nonamphetamine. In attempts to circumvent the laws controlling drugs of abuse, new chemical structures are very frequently introduced on the black market. They are obtained by slightly modifying the controlled molecular structures by adding or changing substituents at various positions on the banned molecules. As a result, no substance similar to those forming a prohibited class may be used nowadays, even if it has not been specifically listed. Therefore, reliable, fast and accessible systems capable of modeling and then identifying similarities at molecular level, are highly needed for epidemiological, clinical, and forensic purposes. In order to obtain the expert systems, we have preprocessed a concatenated spectral database, representing the GC-FTIR (gas chromatography-Fourier transform infrared spectrometry) and GC-MS (gas chromatography-mass spectrometry) spectra of 103 forensic compounds. The database was used as input for a Principal Component Analysis (PCA). The scores of the forensic compounds on the main principal components (PCs) were then used as inputs for the ANN systems. We have built eight PC-ANN systems (principal component analysis coupled with artificial neural network) with a different number of input variables: 15 PCs, 16 PCs, 17 PCs, 18 PCs, 19 PCs, 20 PCs, 21 PCs and 22 PCs. The best expert system was found to be the ANN network built with 18 PCs, which accounts for an explained variance of 77%. This expert system has the best sensitivity (a rate of classification C = 100% and a rate of true positives TP = 100%), as well as a good selectivity (a rate of true negatives TN = 92.77%). A comparative analysis of the validation results of all expert systems is presented, and the input variables with the highest discrimination power are discussed.     

Escitalopram Targets Oxidative Stress,Caspase-3, BDNF and MeCP2 in the Hippocampus and Frontal Cortex of a Rat Model of Depression Induced by Chronic Unpredictable Mild Stress

In recent years, escitalopram (ESC) has been suggested to have different mechanisms of action beyond its well known selective serotonin reuptake inhibition. The aim of this study is to investigate the effects of escitalopram on oxidative stress, apoptosis, brain-derived neurotrophic factor (BDNF), Methyl-CpG-binding protein 2 (MeCP2), and oligodendrocytes number in the brain of chronic unpredictable mild stress-induced depressed rats. The animals were randomised in four groups (8 in each group): control, stress, stress + ESC 5 and stress + ESC 5/10. ESC was administered for 42 days in a fixed dose (5 mg/kg b.w.) or in an up-titration regimen (21 days ESC 5 mg/kg b.w. then 21 days ESC 10 mg/kg b.w.). Sucrose preference test (SPT) and elevated plus maze (EPM) were also performed. ESC improved the percentage of sucrose preference, locomotion and anxiety. ESC5/10 reduced the oxidative damage in the hippocampus and improved the antioxidant defence in the hippocampus and frontal lobe. ESC5/10 lowered caspase 3 activity in the hippocampus. Escitalopram had a modulatory effect on BDNF and the number of oligodendrocytes in the hippocampus and frontal lobe and also improved the MeCP2 expressions. The results confirm the multiple pathways implicated in the pathogenesis of depression and suggest that escitalopram exerts an antidepressant effect via different intricate mechanisms.     

Composites of Poly(Acrylate) Copolymer filled with diatomaceous earth: morphology and mechanical behaviour

Failure mechanisms of poly(acrylate) (PA) copolymer system filled with a diatom filler have been studied. The natural diatom filler is characterised by the original skeletal structure which allows high "inner" porosity and thus matrix penetration inside the filler particles and agglomerates of various shapes in PA composite. High diatom filler crystallinity influences the matrix re-structurization by changing the intensity ratio of matrix amorphous halos indicating the increased composite film inhomogeneity. Interactions at the interface between diatom filler and PA copolymer matrix, specially for coarse cylindrical-shaped particles are low, showing low adhesion in the composite. We see composite weakening with the increased filler volume fraction, i.e. lowering the composite strength at break as a consequence of lower degree of interactions. On the other hand, the composite modulus and the yield strength increased as a result of matrix hardening due to the pronounced matrix penetration inside the porous diatom filler. The mechanisms of failure depend on the location with the lowest product of composite module and break energy. Because dewetting occurred, it is the product EG in the interfacial region between PA matrix and diatom filler particles that was relevant. The effects of filler characteristics, may be followed through an interaction coefficients calculated from a model equations. The numerical values of coefficients in the model are only comparative, but the relative values can be connected with changes at the interface. Electronic Publication     

A summary and evaluation of recent development on harmonicmitigation techniques useful to adjustable speed drives

The authors examine harmonics in three main power areas: the harmonic source, the harmonic effects on power components, and the mitigation techniques used to reduce the amplitude of such harmonics. They cover briefly background information on the first two areas by focusing on electronic motor drives, specifically adjustable speed drives since there are an estimated 400000 units online in the United States, which translates into a large harmonic penetration level. Further summarized are some of the harmonic effects on power system components. A summary and evaluation of developments on harmonic mitigation techniques (HMTs) that have been introduced in the past four years are presented. A classification for all of these HMTs is provided, along with several other facts related to this topic     

Analysis of actinomycin D-DNA model complexes using a quantum-chemical criterion: Mulliken overlap populations

The binding of the antitumoral drug actinomycin D to single- and double-stranded DNA was investigated using molecular modeling in the frame of MM+ molecular mechanics and AM1 semi-empirical method. Two other programs, especially conceived to analyze hydrogen-bonding patterns in biological macromolecules, HBexplore, based on geometrical criteria and SHB_interactions, based on quantum-chemical criteria (Mulliken overlap populations), were also used. The results account for the non-cooperative intercalative binding process previously investigated, and outline the contribution of specific hydrogen bonding as well as CH...O(N) and other atom-atom intermolecular interactions to the stabilization of the actinomycin D-DNA complexes. They also support the hemi-intercalation model proposed in literature for the actinomycin D-ssDNA complex.     

Ego identity, social anxiety, social support, and self-concealment in lesbian, gay, and bisexual individuals.

This study examined a model in which the relationship between social anxiety and two dimensions of ego identity (commitment and exploration) was expected to be mediated by social support and self-concealment for a sample of lesbian, gay, and bisexual individuals (N=347). Statistically significant paths were found from social anxiety to social support and self-concealment. Statistically significant paths were also found from social support to commitment, exploration, and self-concealment. There were no significant paths from social anxiety to commitment or exploration. Structural equation analyses and bootstrap procedures revealed support for the potential mediational role of social support in the association between social anxiety and the two dimensions of ego identity as well as in the link between social anxiety and self-concealment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Determination of Substrate Preferences for Desaturases and Elongases for Production of Docosahexaenoic Acid from Oleic Acid in Engineered Canola

Production of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in plant seed oils has been pursued to improve availability of these omega‐3 fatty acids that provide important human health benefits. Canola (Brassica napus), through the introduction of 10 enzymes, can convert oleic acid (OLA) into EPA and ultimately DHA through a pathway consisting of two elongation and five desaturation steps. Herein we present an assessment of the substrate specificity of the seven desaturases and three elongases that were introduced into canola by expressing individual proteins in yeast. In vivo feeding experiments were conducted with 14 potential fatty acid intermediates in an OLA to DHA pathway to determine the fatty acid substrate profiles for each enzyme. Membrane fractions were prepared from yeast expression strains and shown to contain active enzymes. The elongases, as expected, extended acyl‐CoA substrates in the presence of malonyl‐CoA. To distinguish between enzymes that desaturate CoA‐ and phosphatidylcholine‐linked fatty acid substrates, we developed a novel in vitro method. We show that a delta‐12 desaturase from Phytophthora sojae, an omega‐3 desaturase from Phytophthora infestans and a delta‐4 desaturase from Thraustochytrium sp., all prefer phosphatidylcholine‐linked acyl substrates with comparatively low use of acyl‐CoA substrates. To further validate our method, a delta‐9 desaturase from Saccharomyces cerevisiae was confirmed to use acyl‐CoA as substrate, but could not use phosphatidylcholine‐linked substrates. The results and the assay methods presented herein will be useful in efforts to improve modeling of fatty acid metabolism and production of EPA and DHA in plants.