Investigations on the extractability of gluten proteins from wheat bread in comparison with flour

 Immunochemical methods are recommended for the quantitation of small amounts of gluten in food produced for those with coeliac disease. A major problem, however, is the reduced extractability of gliadin, the toxic factor of gluten, with aqueous alcohol, when foods have been heat-processed. A combined extraction/HPLC procedure was used to study the extractability of all gluten protein types from wheat flour and bread under both non-reducing and reducing conditions. Gliadin isolated from wheat flour was used as a reference protein for quantitation. The results indicate that the extractability of gliadin from bread with 60% ethanol under non-reducing conditions is strongly reduced. α- and γ-gliadins are much more affected than ω-gliadins, and less gliadin was extracted from the crust than from the crumb. For a complete extraction of gliadins from bread, reducing conditions and increased temperature are required. However, glutenin subunits are coextracted with the gliadins. This extract can be used for the quantitation of total gluten proteins by RP-HPLC. The recovery of gliadin added to flour before dough-mixing and bread-making is 98%. Received: 16 February 1998     

The information-processing theory of mind.

H. A. Simon expresses his thanks for receiving the American Psychological Association citation for outstanding lifetime contribution to psychology. He describes cognitive psychology as a progressive science that, building on behaviorist and Gestalt foundations, has continually broadened and deepened the phenomena that it can predict and explain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Calibration of human locomotion and models of perceptual-motor organization.

People coordinate the force and direction of skilled actions with target locations and adjust the calibrations to compensate for changing circumstances. Are the adjustments globally organized (adjusting a particular action to fit a particular circumstance would generalize to all actions in the same circumstance); anatomically specific (every effector is adjusted independently of others); or functional (adjustments would generalize to all actions serving the same goal and generating the same perceptible consequences)? Across 10 experiments, changes in the calibration of walking, throwing, and turning-in-place were induced, and generalization of changes in calibration to functionally related and unrelated actions were tested. The experiments demonstrate that humans rapidly adjust the calibration of their walking, turning, and throwing to changing circumstances, and a functional model of perceptual-motor organization is suggested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Angiotensin II interacts with nitric oxide-cyclic GMP pathway in the central control of drinking behaviour: mapping with c-fos and NADPH-diaphorase

Recognition of the role of nitric oxide in cell-to-cell communication has changed the concept of traditional neurotransmission. We have shown previously that N-methyl-D-aspartate receptors mediate dipsogenic responses and c-Fos expression induced by intracerebroventricular infusion of angiotensin II. Since these receptors are known to be linked to the nitric oxide-cyclic GMP pathway, the present study explores the contribution of this path to the behavioural and cellular effects of intracerebroventricular angiotensin II by using behavioural testing, NADPH-diaphorase histochemistry and immunocytochemical staining for the immediate-early gene, c-fos. N(G)-nitro-L-arginine methyl ester (125 and 250 microg, intracerebroventricular), an inhibitor of nitric oxide synthase, and Methylene Blue (100 microg), an inhibitor of guanylate cyclase activation, antagonized water intake induced by intracerebroventricular injection of 25 pmol angiotensin II. The effects of N(G)-nitro-L-arginine methyl ester were reversed by co-injection of L-arginine, the substrate for nitric oxide synthase. However, N(G)-nitro-L-arginine methyl ester did not alter the pattern of angiotensin II-induced c-fos expression in the organum vasculosum of the lamina terminalis, median preoptic nucleus, hypothalamic paraventricular nucleus and supraoptic nucleus. Double staining with NADPH-diaphorase histochemistry and c-Fos immunocytochemistry showed that neurons staining for both were localized to the anterior third ventricle. However, only 19-25% of the c-Fos-positive neurons expressed NADPH. There were also substantial numbers of neurons in which angiotensin II induced c-Fos that were NADPH-negative. Extensive co-distribution of NADPH-diaphorase-stained cells and those expressing c-fos in response to intracerebroventricular injection of angiotensin II, especially in the median preoptic nucleus, imply that nitric oxide might participate in the mechanism of angiotensin II-induced drinking behaviour. However, a low rate of co-localization of the two markers to individual cells suggests that angiotensin II stimulated the production of nitric oxide and c-Fos in different populations of neurons. Since our previous results showed that glutamate blockade, but not nitric oxide synthase inhibition, suppressed angiotensin II-induced c-Fos, the experiments reported here further suggest that nitric oxide release is not an essential requirement for the expression of c-fos elicited by angiotensin II. They also provide evidence that the dipsogenic and c-Fos responses to angiotensin II are dissociated at a cellular level.     

The influence of Fusarium infection and growing location on the quantitative protein composition of (part I) emmer (Triticum dicoccum)

The effect of the fungal infection Fusarium graminearum and Fusarium culmorum on naked barley cultivars (n = 7) with respect to the barley’s total protein content and the content of the protein fractions albumins + globulins, prolamins (hordeins) and glutelins (hordenins) was investigated. A summer barley cultivar (n = 1) was used for comparison. The total protein content of the whole grain flours was very variable, ranging from 125 to 225 g kg⁻¹. The influence of Fusarium infection showed that the content of hordeins and hordenins was slightly reduced, while the albumins and globulins were not affected. In addition, the effect of the two different growing locations on the protein content of the naked barley was also evaluated. It could be shown that the C-hordeins, γ-hordeins and D-hordenins were significantly positively affected by increasing nitrogen supply, whereas the B-hordenin content was significantly negatively influenced. Nitrogen availability seems to be a factor that promotes gene expression for hordeins but reduces the synthesis of the main B-hordenins.     

Effects of microreactor wall heat conduction on the reforming process of methane

In this paper, the effect of wall conduction of an autothermal tubular methane microreformer is investigated numerically. It is found that the axial wall conduction can strongly influence the performance of the microreactor and should not be neglected without a careful a priori investigation of its impact. By increasing the wall thermal conductivity, the maximum wall surface temperature is decreased. Due to the complex exothermic–endothermic nature of the chemistry of reforming, the axial variation of the wall temperature is not monotonic. Methane conversion and hydrogen yield are strongly dependent on the wall inner surface temperature, hence the heat conduction through the channel wall. The equivalence ratio and the wall thickness also significantly affect the reforming effectiveness and must be carefully considered in reactor optimization. Furthermore, it is found that exothermic oxidation reaction mechanisms, especially partial oxidation, are responsible for syngas (hydrogen and carbon monoxide) production near the inlet. Farther downstream, in the oxygen deficient region, endothermic steam reforming is the main hydrogen producing mechanism. By increasing the thermal conductivity, steam reforming becomes stronger and partial oxidation becomes weaker. For all investigated inlet conditions, the highest hydrogen yield is obtained for no or very low conductive walls.     

One-trial cocaine-induced behavioral sensitization in preweanling rats: Role of contextual stimuli.

Using a one-trial procedure, preweanling rats exhibit robust sensitization regardless of whether drug pretreatment and testing occur in the same or different environments. The purpose of the present study was to determine whether one-trial context-specific and context-independent sensitization of preweanling rats could be dissociated by varying the pretreatment dose of cocaine, by varying the pretreatment drug, or by minimizing interoceptive cues. In Experiments 1a and 1b, rats were pretreated with a broad dose range of cocaine (0–40 mg/kg) before placement in a novel activity chamber or the home cage. In Experiment 2, rats were pretreated with a locomotor-enhancing drug (e.g., methylphenidate, U50,488, or MK-801) before placement in a novel activity or anesthesia chamber. In Experiment 3, rats were anesthetized with isoflurane before cocaine administration to minimize the effects of interoceptive and injection cues. In all experiments, rats were challenged with cocaine on the test day (24 hr later), with locomotion being measured in activity chambers. Results showed that (a) the pretreatment dose of cocaine (10–40 mg/kg) did not differentially affect context-specific and context-independent sensitization; (b) cross-sensitization between methylphenidate and cocaine was observed in the context-specific condition, but not when using a context-independent procedure; and (c) sensitization was evident if injection and interoceptive cues were minimized. One possibility is that associative processes do not modulate the one-trial sensitization of preweanling rats. Alternatively, “unitization” may cause preweanling rats to treat the different environments as equivalent, thus permitting robust sensitization even when drug pretreatment and testing occur in different environments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Within-school social comparison: How students perceive the standing of their class predicts academic self-concept.

Results from prior research indicate that a student’s academic self-concept is negatively influenced by the achievement of others in his or her school (a frame of reference effect) and that this negative frame of reference effect is not or only slightly reduced by the quality, standing, or prestige of the track or school attended (a “reflected glory” effect). Going beyond prior studies, the present research used both between-school and within-school approaches to investigate frame of reference and reflected glory effects in education, incorporating students’ own perceptions of the standing of their school and class. Multilevel analyses were performed with data from 3 large-scale assessments with 4,810, 1,502, and 4,247 students, respectively. Findings from all 3 studies showed that, given comparable individual achievement, placement in high-achieving learning groups was associated with comparatively low academic self-concepts. However, students’ academic self-concept was not merely a reflection of their relative position within the class but also substantively associated with their individual and shared perceptions of the class’s standing. Moreover, the negative effects of being placed in high-achieving learning groups were weaker for high-achieving students. Overall, the studies support both educational and social psychology theorizing on social comparison. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Applications of the psychotherapy phase model to clinically significant deterioration.

While previous research on deterioration has focused on identifying individuals at risk for negative outcomes, little is known about the nature or pattern by which deterioration occurs. The problem of deterioration is especially salient in training clinics; a setting in which higher deterioration rates have been reported. Two studies were designed to test the applicability of the phase model to deterioration in a training clinic and to replicate the model with a training clinic referral-base sample. In Study 1, the course of therapy was monitored for 135 clients. For the 38 clients who deteriorated during therapy, a model where increased symptoms (demediation) reliably preceded both decreased functioning (dehabilitation) and decreased well-being (demoralization) was found. In Study 2, the same three phases were prospectively monitored for 914 undergraduate students on a weekly basis throughout a single semester. For the 158 individuals who deteriorated during this time, a model where demediation reliably preceded dehabilitation, which preceded demoralization was found. These results have clinical implications for the use of tailored intervention strategies focusing on the deterioration phases. (PsycINFO Database Record (c) 2010 APA, all rights reserved)