Influence of caecectomy and dietary protein concentration on apparent excreta amino acid digestibility in adult cockerels

Infestation with ixodid tick stimulates the immune regulatory and effector pathways of the hosts involving antigen presenting cells, T-lymphocytes, B-lymphocytes, basophils, mast cells, eosinophils and a variety of bioactive molecules like cytokines, antibodies and complement. Tick-mediated immunosuppression has been investigated using cells derived from infested animals and by exposing cells from uninfected animals to tick salivary gland molecules. Tick-induced suppression of host immune defences is characterized by reduced ability of lymphocytes from infested animals to proliferate in vitro in the presence of concanavalin A (Con A), diminished primary antibody responses to T-cell dependent antigen, and decreased elaboration of macrophage (IL-1 and TNF-alpha) and Th1-lymphocyte cytokines (IFN-gamma), whereas Th2 cytokines production (IL-4, IL-5 and IL-10) is enhanced. It is known that IL-10 inhibits Th1 cell development and also reduces the in vitro T-lymphocyte proliferative response to Con A stimulation. Proteins which inhibited T-lymphocyte in vitro responsiveness to Con A were also isolated from tick salivary glands.     

Memory colour effects as a function of viewing time.

Instructed 60 Ss to judge the color of 2 objects, an apple, and a circle, relative to the colors of 5 samples. The apple was judged significantly redder than the circle, indicating a memory color effect. There was also an indication that this effect was stronger when the test object was viewed for 300 msec. than when it was seen for either more or less time. These results fit a modified version of J. S. Bruner's model of perceptual processing. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

ME1—marine energy extraction: tidal resource analysis

This paper outlines some of the issues which need to be considered when analysing the extraction potential of a tidal current resource. Site selection is not a simple case of identifying an energetic site with an appropriately large peak tidal current. The characteristics of the current throughout the lunar tidal cycle must be considered. Furthermore, implicit in such an analysis is the assumption that the local tidal flow conditions will not be significantly altered by the energy extraction process itself. For high extraction rates, the general validity of this assumption is questionable. The influence of energy extraction upon the underlying hydraulic nature of the tidal environment must be considered. Analysis based upon open channel flow theory demonstrates that energy extraction in a simple channel driven by static head differences can have a significant upstream and downstream effect. This suggests that the environmental impact of energy extraction is not necessarily restricted to the immediate area around the extraction site. It also suggests that there is potential for the process of energy extraction to either diminish or even enhance the available resource at a particular site. Further research is required and is ongoing in this area. In the case examined, the limits to exploitation are shown to be inexact. However, a useful approximate guideline for resource analysis would be that 10% of the raw energy flux produced by the tide can be extracted without causing undue modification to the flow characteristics.     

Editorial.

Presents a reaffirmation of the goals of the Canadian Journal of Psychology. The primary objective of the Canadian Journal of Psychology is to provide a vehicle for the communication of scientific research in general experimental psychology. The editor hopes to encourage Canadian experimental psychologists to take pride in their Journal, and submit their quality work to it. The Journal will continue to maintain a small and selective book review section, and it will maintain its short report section. There is no question that there is ample material to fill the pages of the Journal and make it interesting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nutritional evaluation of transgenic high‐methionine lupins (Lupinus angustifolius L) with broiler chickens

The nutritive value of transgenic lupin seeds (Lupinus angustifolius L) with higher contents of methionine was evaluated with broiler chickens. The crude protein, methionine and cysteine contents in the conventional and transgenic lupins were 322 and 324, 2.0 and 4.5, and 3.6 and 3.7 g kg^?1 dry matter respectively. In the feeding trial, conventional and transgenic lupins with hulls were incorporated into a maize–soyabean meal diet at 250 g kg^?1 level and the diets were fed to female broiler chicks from 6 to 20 days of age. All diets were balanced to contain similar levels of apparent metabolisable energy (AME), lysine and sulphur‐containing amino acids. The levels of free methionine added to the maize–soyabean meal control, conventional lupin and transgenic lupin diets were 2.2, 2.8 and 2.2 g kg^?1 respectively. Weight gain and feed intake were not influenced by dietary treatments, but feed/gain tended to be higher (P = 0.09) in birds fed lupin diets compared with those fed the control diet. Feed/gain of birds fed the conventional lupin diet was higher (1.82 vs 1.74) than for those fed the transgenic lupin diet. These results showed that the supplemental methionine required in poultry diets containing 250 g kg^?1 lupin can be lowered by 0.6 g kg^?1 diet by the use of high‐methionine lupins. The AME values of conventional and transgenic lupins were determined to be 9.42 and 10.18 MJ kg^?1 dry matter respectively. The higher AME value in transgenic lupins may be related to the lower content of soluble non‐starch polysaccharides (45.6 vs 60.7 g kg^?1 air‐dry basis). Data on ileal amino acid digestibility indicate that the amino acids in transgenic lupins are as digestible as those in conventional lupins. © 2002 Society of Chemical Industry     

Planned tournament selection

Tournament selection is a versatile method of selection and replacement used in evolutionary computation. Normally tournaments are chosen uniformly at random. This study demonstrates the effectiveness of planning tournaments in advance to control information flow within a population being evolved for optimization. Tests are performed on a variety of evolutionary test problems, finding that different planned tournament schemes yield significant differences in performance. The correct type of planned tournament is found to be problem dependent. In addition to a linear-function scheme for planning tournaments, this study also introduces a technique called multi-deme planned tournaments selection which permits simpler cases of a problem to be automatically used to reduce the time required to solve more complex cases.     

Trends in the use of large wood in UK river restoration projects: insights from the National River Restoration Inventory

Large Wood (LW) is increasingly employed in river restoration to promote physical habitat heterogeneity and ecological diversity. To explore how LW has been used in restoration schemes across the United Kingdom in recent decades, we analysed data on 912 LW projects archived in the UK’s National River Restoration Inventory (NRRI). The number of LW schemes has continued to increase following the earliest records in the 1990s, largely tracking overall trends in river restorations. LW projects have been predominantly located in lowland, rural streams, although there has been a notable cluster in and around London. LW projects have mainly revolved around the desire to deliver hydromorphological improvements and specifically the creation of fish habitat. Most schemes used LW in simple deflector forms despite the growing scientific evidence of the benefits of using structurally complex LW. Post project monitoring has been limited and mostly restricted to photographic records. This type of database analysis can provide important insights and help guide future restoration practice.     

Total and ileal digestible tryptophan contents of feedstuffs for broiler chickens

Reliable values of total and digestible tryptophan in components of feed formulation matrices are needed because tryptophan is often the third limiting amino acid in practical poultry diets. However, tryptophan is oxidatively destroyed during acid hydrolysis in routine amino acid analysis and its determination requires a separate analytical procedure. The variability in contents and apparent ileal digestibility for 6‐week‐old broiler chickens of tryptophan in 74 samples representing 24 feedstuffs are presented in this paper. The average ileal tryptophan digestibility coefficient in wheat was 0.83, in sorghum and triticale 0.75, maize 0.71, soybean meal 0.84, sunflower meal 0.81, canola meal 0.78 and cottonseed meal 0.75. Among the grain legumes, tryptophan in lupins was better digested than that in chickpeas, fababeans and field peas. Among the animal protein meals, the tryptophan digestibility coefficients in fish meal (0.77) and blood meal (0.84) were substantially higher than those in meat meal (0.62), meat‐and‐bone meal (0.63) and feather meal (0.52). Marked variations in tryptophan digestibility were also observed among samples of fish meal, meat‐and‐bone meal and meat meal, highlighting significant batch‐to‐batch differences. For most feedstuffs, considerable variability was observed in the tryptophan concentrations, but such variations were not reflected in digestibility coefficients. Copyright © 2006 Society of Chemical Industry     

Effects of chromium and guar on sugar-induced hypertension in rats

Ingestion of sugars (sucrose, fructose, glucose) by various rat strains is associated with perturbations in the glucose/insulin system and higher systolic blood pressure (SBP). The association suggests causality, because alterations in insulin metabolism have been found in essential hypertension and many experimental forms of hypertension. To test the hypothesis that sugar-induced SBP elevation is secondary to perturbed insulin metabolism, we examined in 2 experiments effects of chromium and guar, substances known to affect insulin metabolism, on SBP of Spontaneously Hypertensive Rats (SHR). In both studies, sucrose compared to starch ingestion caused significant elevation of SBP; but addition of 2 chromium nicotinate complexes and guar prevented development of sugar-induced SBP elevations. The basal, genetic hypertension of the SHR was not affected by either nutrient. An additional finding in the first study was that sugar-consuming SHR supplemented with chromium had greater BW and increased organ weight (kidney, spleen, and liver) than nonsupplemented SHR. Accordingly, we have shown that two different mechanisms known to ameliorate insulin perturbations, use of chromium and guar, prevent sugar-induced SBP elevations. Since essential hypertension may be due to insulin perturbations and high dose chromium supplementation seems nontoxic, this may prove to be a useful means to lower blood pressure (BP) in some essential hypertensives, as well as diabetic hypertensives. Soluble fiber in the form of guar is also quite effective in favorably influencing sugar-induced SBP elevations.