Effect of thermal treatment on the proteins of amaranth isolates

The effect of thermal treatment of proteins from Amaranthus hypochondriacus was studied. Two protein isolates were obtained from the defatted flour by water extraction at a pH of 9 (A9 isolate) and 11 (A11 isolate), followed by isoelectric precipitation at a pH of 5. Effect of thermal treatment (70 and 90 °C, during 3, 5, 10, 15 and 30 min) on A9 and A11 dispersions were analyzed by differential scanning calorimetry (DSC), polyacrylamide gel electrophoresis, UV spectrophotometry, superficial hydrophobicity and solubility in water. Thermal treatment induced the aggregate formation of high molecular mass stabilized by disulfide and non‐covalent bond. Thermal treatment at 70 °C produced a 30% denaturation in both, while at 90 °C A9 was more denatured than A11 (75% and 55% of denaturation, respectively). An increase in thermal stability was also detected by DSC in A9 treated at 90 °C. The denaturation process was accompanied at short heating times by an increase in UV absorbance and changes in superficial hydrophobicity. A decrease in water solubility (35–50%, depending on time–temperature conditions) was also observed for the A9 isolates. The results suggest that the A9 isolates, enriched in a globulin protein fraction, are more sensitive to thermal treatment than isolates A11 enriched in glutelin protein fraction. The changes shown by both isolates, indeed, could affect their functional properties and could definitely limit their use in food products. Copyright © 2007 Society of Chemical Industry     

Localization and speciation of chromium in subterranean clover using XRF, XANES, and EPR spectroscopy

Optimization of phytoremediation and assessment of potential health hazards from metals in the environment requires an understanding of absorption, localization, and transport of the target metal by plants. The objectives of this study were to localize Cr and determine the oxidation state and possible complexation mode of Cr in intact plant tissue by means of XANES, synchrotron XRF microprobe spectroscopy, and EPR spectroscopy. Subterranean clover (Trifolium brachycalycinum) was grown hydroponically with Cr(VI) (0.04-2.0 mmol L(-1)) and compared with plants grown without Cr and with inorganic Cr(III) and various Cr(III)-organic sources. The uptake, translocation, and form of Cr in the plant were dependent on the form and concentration of supplied Cr. Chromium was found predominately in the +3 oxidation state, regardless of the Cr source supplied to the plant, though at high Cr(VI) treatment concentrations, Cr(VI) and Cr(V) were also observed. At low Cr(VI) concentrations, the plant effectively reduced the toxic Cr(VI) to less toxic Cr(III), which was observed both as a Cr(III) hydroxide phase at the roots and as a Cr(III)-organic complex in the roots and shoots. At low Cr(VI) treatment concentrations, Cr in the leaves was observed predominately around the leaf margins, while at higher concentrations Cr was accumulated at leaf veins.     

Different enrichment procedures for recovery of Listeria monocytogenes from raw chicken samples can affect the results of detection (by chromogenic plating or real-time PCR) and lineage or strain identification

This study aimed to evaluate the effect of different enrichment procedures on the detection of Listeria monocytogenes in food, by a comparison of subculture onto chromogenic agar with real-time PCR. Two different culture media, the primary and secondary enrichment broths of the U.S. Food Safety and Inspection Service (FSIS) method used for PCR detection of L. monocytogenes, were compared for the primary enrichment of retail ground chicken samples. L. monocytogenes was detected after the completion of each enrichment procedure in 63% (complete FSIS procedure) and 60% (plain FSIS secondary enrichment broth incubated for 48 h) of the samples by both culture and PCR, whereas a combination of the results for the two enrichment procedures revealed 86% of the samples to be positive. Most of the samples analyzed contained a mixture of lineage I and II strains, and their ratio varied for each enrichment procedure. This mixture could have a significant effect on the result of detection of L. monocytogenes for each individual sample, explaining the increase in positive samples when the results of the two enrichment procedures were combined. The use of different isolation procedures can affect the specific samples identified as positive and the specific strains isolated.     

How Henri Lefebvre missed the modernist sensibility of Mies van der Rohe: vitalism at the intersection of a materialist conception of space and a metaphysical approach to architecture

This paper looks at two theoretical statements about ‘space’, both of which are grounded in a vitalist philosophy. The first is Henri Lefebvre's formulation of ‘spatial architectonics’, a structure of concepts which he develops in The Production of Space; the second is Mies van der Rohe's intuition of something he termed ‘authentic form’, a means of triggering new experiences and understandings through sensual engagement with space. Since there are other philosophers and other architects whose thinking about space has been influenced by vitalist philosophy, the discussion will begin with an explanation as to why Lefebvre and van der Rohe have been selected for reciprocal examination.     

Identification of Host Attractants for the Ethiopian Fruit Fly, <Emphasis Type="Italic">Dacus ciliatus</Emphasis> Loew

The Ethiopian fruit fly, Dacus ciliatus, is an oligophagous pest of cucurbit crops, particularly melons, cucumbers, and marrows (summer squash). The present study aimed to identify host attractants for D. ciliatus and was guided by a behavioral bioassay and an electrophysiological assay. We tested volatile compounds from the fruits of a host plant, ripe and unripe Galia melon, Cucumis melo var. reticulates. Both sexes were attracted to melon volatiles. Those of ripe melon were preferred. Gas chromatography-electroantennographic detection analysis of the behaviorally active ripe melon volatiles consistently showed that 14 compounds elicited similar antennal responses from both sexes. Twelve compounds were identified by gas chromatography-mass spectrometry (GC-MS) using GC-MS libraries, retention indices (RI), and authentic standards. The electrophysiological activities of the compounds that were present at sufficient levels for identification, benzyl acetate, hexanyl acetate, (Z)-3-hexenyl acetate, (Z)-3-octenyl acetate, octanyl acetate, (Z)-3-decenyl acetate, and (E)-β-farnesene, were evaluated at six different dosage levels by using electroantennography (EAG). Benzyl and hexanyl acetates elicited dose responses only in males, while other tested compounds elicited dose responses in both sexes. The strongest responses were observed for doses between 100 ng and 10 μg. The dose response, in terms of attractiveness to synthetic compounds within the active range (as determined by EAG), also was evaluated in the behavioral bioassay. Synthetic acetates were attractive to both sexes when tested individually. Significant attraction was observed when individual compounds were applied in the bioassay arena at doses of 0.5–1 μg/dispenser. Blends of compounds in equal proportions also were attractive to the insects. The most attractive blend was a mixture of four or five identified acetates. The addition of an equal proportion of (E)-β-farnesene to this mixture had a deterrent effect.     

Who said what? Source memory for narrator and character agents in literary short stories.

One dimension of reading literacy involves the tracking of agents associated with the text. In a literary short story, there is a society of character agents and pragmatic agents. This study investigated the relative salience of different classes of agents in memory. Two experiments measured source memory as an index of agent salience in long-term memory. Patterns of source memory scores supported an invisible third-person narrator hypothesis and an agent amalgamation hypothesis, but not a structural prominence hypothesis: First-person narrator > nonnarrator character > third-person narrator > 0. Statement detection parameters did not significantly differ among the 3 classes of agents, so differences in source memory could not be explained by differences in the content of the speech acts. Source memory scores also could not be explained by surface features of the text, differences among readers, and sophisticated guessing on the basis of a story abstract. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adaptation of the van Genuchten expression to the effects of temperature and density for compacted bentonites

The main objective of this work is to highlight the influence of variables like temperature and porosity (dry density) on the water retention curve of expansive clays for the analysis of thermo-hydro-mechanical coupled processes (THM problem).The paper presents retention curves of MX-80 bentonite measured under isochoric conditions for different dry densities and temperatures. The influence of dry density on the water retention capacity depends on the suction range, the limiting value being around 30 MPa. For suctions above this threshold value, the retention capacity in terms of water content is higher as the dry density increases, whereas for lower suctions, the lower the dry density the higher the water content for a particular suction. The retention capacity decreases with temperature, more than predicted by the change in interfacial tension of air–water, especially for high temperatures and low suctions.Accordingly, some modifications of the van Genuchten [van Genuchten, M.Th., 1980. A closed-form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Sci. Soc. Am. J., 44, 892–898.] law have been proposed to fit the experimental values. Effects of temperature and porosity on the water retention capacity (other than the traditionally included in the air entry value coefficient) were incorporated through empirical laws that resemble the experimental evidences. By a fitting process, values of the coefficients in those laws were determined for the material used in this work.Finally, several 1D THM simulations using the computer code “CODE_BRIGHT” have been performed in order to analyse the consequences of considering or not temperature and density influences on the water retention curve.     

Rural tourism: A sustainable alternative

The aim of this article is to show and share the results of the research we made in order to improve the situation of sustainable interior rural tourism in Spain. We chose our region: Aragon and we studied the case. We had to consider the financial crisis in the hope that our results would contribute to minimize it. We knew beforehand that rural tourism had been less affected than other sectors but still it was important to reach our goal.     

Effects of postharvest UV‐C treatment on carotenoids and phenolic compounds of vine‐ripe tomatoes

Light red tomatoes were exposed to different doses of ultraviolet C (UV‐C) irradiation (1.0, 3.0 and 12.2 kJ m^?2). After treatment, the tomatoes were stored for 2 days at room temperature, and then analysed to determine the effect of irradiation on the main antioxidants, carotenoids and phenolic compounds and the results compared with the control samples. The lycopene content was found to have increased by 14% with respect to the control samples, while β‐carotene decreased. Cis‐isomers from lycopene also increased when the tomatoes were exposed to irradiation for more than 3 h. UV‐C irradiation also had a positive effect on total phenolic compounds; however, the same effect was not observed in the individually analysed phenolic compounds. While chlorogenic and ferulic acids increased in content, naringenin and rutin contents decreased. These results suggest that UV‐C irradiation of tomatoes could improve the beneficial effect of red tomatoes for human health by increasing the levels of certain bioactive compounds; it could also be used to obtain higher content of bioavailability components, such as cis‐isomers from lycopene.