Combined Smoking and Drying Kinetics of Retted Cassava Pulp and Effects on the Physicochemical and Pasting Properties of the Extracted Starch

Cooked paste of smoked-dried flour of retted cassava is the staple food of million people in West and Central Africa. The present study investigates the dynamics of combined smoking and drying on some physicochemical and functional properties of the flour and its derived starch. Fresh cassava tubers (variety 4115) were trimmed, retted, wrung, crushed, put into balls and then dried using three processes: traditional combined smoking and drying, electrical combined smoking and drying, and oven-drying. The drying processes did not significantly modify (p?>?0.05) the proximate composition of samples neither their drying rates (0.19 h^?1?<?k?<?0.22 h^?1). A positive and significant correlation was shown between the drying constant k and the smoking constant k _s (p?<?0.05). The colour of the oven-dried flour sample was clearer with the highest whiteness index (86.11?±?0.76) than the flour from traditional and electrical combined smoking and drying processes (65.41?±?4.35 and 68.18?±?3.98, respectively). The peak viscosity and breakdown values of retted starch paste were significantly higher (p?<?0.05) than that of the flour from which it originated. Meanwhile, the starch cold paste exhibited lower setback values and thus a lesser tendency to retrogradation when compared to retted flour gel. All this suggests that despite the relative instability of temperature in the traditional attic, it preserves, in comparable extent, the functional and nutritional values of cassava derivatives as electrical drying processes. Considering the functional use of the retted cassava for fufu preparation, smoked-dried starch is more suitable for cooking than oven-dried starch. In addition, the electrical combined smoking and drying process appeared as the best drying method, since the derived product has low tendency to retrogradation.     

Glucosinolates in isaño (Tropaeolum tuberosum) tubers: qualitative and quantitative content and changes after maturity

Six varieties of isaño (Tropaeolum tuberosum), an Andean edible tuber, were analysed. The aim was to characterise qualitatively and quantitatively their content of glucosinolates and to determine concentration changes of these compounds upon delayed harvest. Additionally, exploratory assays were carried out on the effect of postharvest cold storage of the tubers as well as of a drying process imposed on blanched tuber slices. Only one glucosinolate (p‐methoxybenzyl glucosinolate) was found in the six domestic varieties analysed. Its concentration varied between 36.5 and 90.0 µmol g^?1 dry matter. This range is relatively high when compared with other edible glucosinolate‐containing vegetables. ‘Dark’ coloured tuber varieties showed higher levels than ‘light’ coloured tuber varieties at normal harvest time. Of the two varieties on which the effect of delayed harvest was studied, one showed increasing and then decreasing changes until 44 days after maturity, while the other did not show any significant change with time. Postharvest cold stored samples showed similar changes to tubers kept in soil, and glucosinolate levels in dried blanched tubers did not differ significantly from those in fresh samples. Taken together, the data indicate that the glucosinolate content of isaño is highly dependent on both the variety and the time of harvest. These parameters should be taken into account when considering isaño as a promising food source with medicinal properties for humans and animals, but also with possible adverse biological effects, all related to the presence of glucosinolates. Copyright © 2004 Society of Chemical Industry     

Fungal pretreatment of wheat straw: Effects on the biodegradability of cell walls,structural polysaccharides,lignin and phenolic acids by rumen microorganisms

Disappearance of cell wall components of untreated straw and straw treated with the ligninolytic white-rot fungi Phanerochaete chrysosporium, Dichomitus squalens and Cyathus stercoreus were determined during the course of rumen digestion of samples in nylon bags. The first fungus degraded hemicelluloses and cellulose non-selectively, adversely affecting the digestion rate of crude cell walls. Dichomitus squalens and C. stercoreus preferentially degraded hemicelluloses and lignin, affording cell wall degradation rates 1.5 times higher than in native straw. Furthermore, the extent of cell wall digestion was also significantly enhanced. Both strains improved the extent of cellulose digestion, whereas the potentially degradable xylan fraction remained unchanged. Polysaccharide digestion rates were influenced in different ways depending on the strain tested: straw degraded by C. stercoreus showed an increase in cellulose digestion rate by 50%, whereas residual arabinose units were slowly degraded. Xylan was degraded 1.8 times faster in straw decayed' by D. squalens, while cellulose digestion remained unchanged. Phanerochaete chrysosporium depressed both xylan and cellulose digestion rates. Fungal-treated lignins were solubilised in the rumen faster than in untreated straw, whereas only treatment by C. stercoreus resulted in higher lignin losses. Esterified phenolic acids were extensively degraded by all three fungi. Residual ferulic and p-coumaric acids accumulated during rumen digestion, although only the former decreased in the original straw.     

Influence of drying mode on iridoid bitter constituent levels in gentian root

Root samples of wild gentian (Gentiana lutea L) were harvested from six localities (altitude 970 m to 1350 m) from May to November 2000. Each batch of roots was split into three: fresh roots, naturally dried roots (ambient air) and artificially dried roots (40 °C). In all the samples, levels of iridoid bitter constituents and of xanthone coloured compounds were determined by HPLC. The mean total iridoid content in the fresh roots was 102.4 g kg^?1 in dry matter (DM). The mean level of the principal bitter compound gentiopicroside was particularly high at 81 g kg^?1 DM. Loganic acid, not previously reported in G lutea, was the second most abundant bitter compound at a mean level of 14.3 g kg^?1 DM. Swertiamarin was present at 5.4 g kg^?1, with another minor unidentified iridoid. Levels of iridoid compounds were strongly dependent of the drying mode. These amounts were 88.5 g kg^?1 DM in artificially dried roots and 62.5 g kg^?1 DM in naturally dried roots, mostly owing to a marked decrease in gentiopicroside. The temperature of 40 °C preserved the bitter compounds and the bitterness of fresh gentian roots. The amount of coloured xanthones was relatively low at 3.3 g kg^?1 and did not change with the drying mode. Copyright © 2004 Society of Chemical Industry     

The concept of psychological regression: Metaphors, mapping, Queen Square, and Tavistock Square.

The term “regression” refers to events in which an individual changes from his or her present level of maturity and regains mental and behavioral characteristics shown at an earlier point in development. This definition has remained constant for over a century, but the implications of the concept have changed systematically from a perspective in which regression was considered pathological, to a current view in which regression may be seen as a positive step in psychotherapy or as a part of normal development. The concept of regression, famously employed by Sigmund Freud and others in his circle, derived from ideas suggested by Herbert Spencer and by John Hughlings Jackson. By the 1940s and '50s, the regression concept was applied by Winnicott and others in treatment of disturbed children and in adult psychotherapy. In addition, behavioral regression came to be seen as a part of a normal developmental trajectory, with a focus on expectable variability. The present article examines historical changes in the regression concept in terms of mapping to biomedical or other metaphors, in terms of a movement from earlier nativism toward an increased environmentalism in psychology, and with respect to other historical factors such as wartime events. The role of dominant metaphors in shifting perspectives on regression is described. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Conductivity enhancement in carbon nanocone adhesive by electric field induced formation of aligned assemblies

We show how an alternating electric field can be used to assemble carbon nanocones (CNCs) and align these assemblies into microscopic wires in a commercial two-component adhesive. The wires form continuous pathways that may electrically connect the alignment electrodes, which leads to directional conductivity (～10(-3) S/m) on a macroscopic scale. This procedure leads to conductivity enhancement of at least 2-3 orders of magnitude in the case where the CNC fraction (～0.2 vol %) is 1 order of magnitude below the percolation threshold (～2 vol %). The alignment and conductivity are maintained on curing that joins the alignment electrodes permanently together. If the aligned CNC wires are damaged before curing, they can be realigned by an extended alignment period. This concept has implications in areas such as electronic packaging technology.     

Ethical supervision in teaching, research, practice, and administration.

Supervision is a specialized area of psychological activity that has its own foundation of knowledge, skills, and attitudes, which are enhanced by training. As our discipline develops its standards for competent practice in supervision, there is a need to develop ethical guidelines to assist both supervisors and supervisees in maintaining productive working relationships. Organized around the hierarchy of ethical principles comprising the Canadian Code of Ethics for Psychologists, the Canadian Psychological Association adopted Ethical Guidelines for Supervision in Psychology: Teaching, Research, Practice, and Administration in early 2009. In this article, each of the four ethical principles (Respect for the Dignity of Persons, Responsible Caring, Integrity in Relationships, and Responsibility to Society) is examined in the context of supervision within the areas of teaching, research, practice, and administration. The history of the guidelines, as well as some of their innovative and unique elements, is also discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)