The effect of storage on the solubilization pattern of bean hull non-starch polysaccharides

The storage of Carioca bean at 30 C and 75% relative humidity for eight months altered the solubilization pattern of hulls non-starch polysaccharides The polysaccharide physicochemical pattern changed resulting in a shift in the composition of water-soluble and water-insoluble polysaccharides caused by the insolubilization of galacturonans and xyloglucan Hulls make up 10% of whole beans which showed an increase of about 5% in water-insoluble polysaccharides and a decrease of about 1% in water-soluble polysaccharides with aging These values suggest that cotyledons and hulls together account for an increase of about 2 g of water-insoluble polysaccharides and a decrease of 1 5 g of water-soluble polysaccharides per 100 g of beans This change in the polysaccharide composition may produce a considerable difference in the dietary fiber profile The alterations observed in bean hull non-starch polysaccharide composition were similar to those previously observed in the cotyledon (C) 2010 Elsevier Ltd All rights reserved

Impact of adenosine nucleotide translocase (ANT) proline isomerization on Ca(2+)-induced cysteine relative mobility/mitochondrial permeability transition pore

Mitochondrial membrane carriers containing proline and cysteine, such as adenine nucleotide translocase (ANT), are potential targets of cyclophilin D (CyP-D) and potential Ca(2+)-induced permeability transition pore (PTP) components or regulators; CyP-D, a mitochondrial peptidyl-prolyl cis-trans isomerase, is the probable target of the PTP inhibitor cyclosporine A (CsA). In the present study, the impact of proline isomerization (from trans to cis) on the mitochondrial membrane carriers containing proline and cysteine was addressed using ANT as model. For this purpose, two different approaches were used: (i) Molecular dynamic (MD) analysis of ANT-Cys(56) relative mobility and (ii) light scattering techniques employing rat liver isolated mitochondria to assess both Ca(2+)-induced ANT conformational change and mitochondrial swelling. ANT-Pro(61) isomerization increased ANT-Cys(56) relative mobility and, moreover, desensitized ANT to the prevention of this effect by ADP. In addition, Ca(2+) induced ANT ""c"" conformation and opened PTP; while the first effect was fully inhibited, the second was only attenuated by CsA or ADP. Atractyloside (ATR), in turn, stabilized Ca(2+)-induced ANT ""c"" conformation, rendering the ANT conformational change and PTP opening less sensitive to the inhibition by CsA or ADP. These results suggest that Ca(2+) induces the ANT ""c"" conformation, apparently associated with PTP opening, but requires the CyP-D peptidyl-prolyl cis-trans isomerase activity for sustaining both effects.

Chemical Signals in the Stingless Bee, Frieseomelitta varia, Indicate Caste, Gender, Age, and Reproductive Status

Chemical compounds on the cuticle are a rich source of information used during interactions among social insects. Despite the multitude of studies on these substances and their function in ants, wasps, and honeybees, little is known about this subject in stingless bees (Hymenoptera: Apidae, Meliponini). We studied the chemical composition of the cuticle of the stingless bee, Frieseomelitta varia, by gas chromatography-mass spectrometry (GC-MS), to investigate potential chemical variation among castes, gender, age, and reproductive status. We found differences in the cuticular hydrocarbon composition among workers, males, and queens, recording both qualitative and quantitative differences among individuals of different ages and gender. The cuticle of physogastric queens presented a chemical profile that was distinct from all other groups in the analysis, with high relative abundances of alkenes and alkadienes with 27, 29, and 31 carbon atoms. We discuss the possibility that these compounds signal a queen`s presence to the colony, thereby initiating all vital worker-queen interactions.

Effect of the Maillard reaction on properties of casein and casein films

The use of biodegradable natural polymers has increased due to the over-solid packaging waste. In this study, a chemical modification of the casein molecule was performed by Maillard reaction, and the modified polymer was evaluated by polyacrylamide gel electrophoresis (PAGE), thermogravimetry/derivative thermogravimetry (TG/DTG), FT-IR, and (1)H-NMR spectroscopy. Subsequently, films based on the modified casein were obtained and characterized by mechanical analysis, water vapor transmission, and erosion behavior. The PAGE results suggested an increase of molecular mass of the modified polymer, and FT-IR spectroscopy data indicated inclusion of C-OH groups into this molecule. The TG/DTG curves of modified casein presented a different thermal decomposition profile compared to the individual compounds. Mechanical tests showed that the chemical modification of the casein molecules provided higher elongation rates (45.5%) to the films, suggesting higher plasticity, than the original molecules (13.4%). The modified casein films presented higher permeability (0.505 +/- A 0.006 mu g/h mm(3)) than the original polymer (0.387 +/- A 0.006 mu g/h mm(3)) films at 90% relative humidity (RH). In pH 1.2, modified casein films presented higher erosion rates (32.690 +/- A 0.692%) than casein films (19.910 +/- A 2.083%) after 8 h, suggesting an increased sensibility for erosion of the modified casein films in acid environment. In water (pH 7.0), the films erosion profiles were similar. Those findings indicate that the modification of molecule by Maillard reaction provided films more plastic, hydrophilic, and sensitive to erosion in acid environment, suggesting that a new polymer with changed properties was founded.

Effect of modifiers for As, Cu and Pb determinations in sugar-cane spirits by GF AAS

Palladium plus magnesium nitrates with and without Ir, Ru and W were evaluated for the simultaneous determination of As, Cu and Pb in cachaca by graphite furnace atomic absorption spectrometry. For 20 mu L sample, 5 mu L Pd(NO(3))(2) and 3 mu L Mg(NO(3))(2) dispensed together onto the Ir-coated platform of the THGA, analytical curves in the 0-30.0 mu g L(-1) As, 0-1.50 mg L(-1) Cu and 0-60.0 mu g L(-1) Pb were built up and typical linear correlation coefficients were always better than 0.999. The limit of detection was 1.30 mu g L(-1) As, 140 mu g L(-1) Cu and 0.90 mu g L(-1) Pb. As, Cu and Pb contents in 10 cachaca samples agreed with those obtained by ICP-MS. Recoveries of spiked samples varied from 96% to 106% (As), 97% to 112% (Cu) and 92% to 108% (Pb). The relative standard deviation (n = 12) was typically 2.7%, 3.3% and 1.9%. (C) 2008 Elsevier Ltd. All rights reserved.

The use of transcriptional profiles to predict adult mosquito age under field conditions

Age is a critical determinant of an adult female mosquito's ability to transmit a range of human pathogens. Despite its central importance, relatively few methods exist with which to accurately determine chronological age of field-caught mosquitoes. This fact is a major constraint on our ability to fully understand the relative importance of vector longevity to disease transmission in different ecological contexts. It also limits our ability to evaluate novel disease control strategies that specifically target mosquito longevity. We report the development of a transcriptional profiling approach to determine age of adult female Aedes aegypti under field conditions. We demonstrate that this approach surpasses current cuticular hydrocarbon methods for both accuracy of predicted age as well as the upper limits at which age can be reliably predicted. The method is based on genes that display age-dependent expression in a range of dipteran insects and, as such, is likely to be broadly applicable to other disease vectors.

Effect of pH on Na induced Ca deficiency

Although it is well known that high Na concentrations induce Ca deficiency in acidic conditions, the effect of high pH on this competitive mechanism is not so well understood. The effect of Ca activity ratio (CAR) and pH on the Ca uptake of mungbeans (Vigna radiata (L.) Wilczek cv. Emerald) and Rhodes grass (Chloris gayana cv. Pioneer) in Na dominated solution cultures and in soil was investigated. Changes in pH in the alkaline range were shown not to affect the critical CAR of 0.024 (corresponding to 90 % relative root length) for mungbeans grown in solution culture. Results from soil grown mungbeans confirmed those from solution culture, with a critical CAR of 0.025. A critical CAR of 0.034 was also established for soil grown Rhodes grass. The similarity of critical values established for mungbeans and Rhodes grass in solution culture and soil justifies the use of both solution culture and soil solution measurement as techniques for studying plant growth and limitations across plant species.

The effect of protein binding on the hepatic first pass of O-acyl salicylate derivatives in the rat

In this work the in-situ perfused rat liver has been used to examine the effect of changing the protein content of the perfusate on the hepatic extraction of O-acyl esters of salicylic acid. The hepatic availability (F) of these solutes was studied at a flow-rate of 30 mt min(-1) with perfusate albumin concentrations of 0, 2, and 4% w/v. The hepatic availability of the esters was shown to decrease with increasing carbon-chain length in the O-acyl group; for all the esters the hepatic availability increased with increasing albumin concentration in the perfusate. The dispersion-model-derived efficiency number (R-N) Of the esters was shown to increase with increasing lipophilicity and decrease with increasing albumin concentration in the perfusate. The unbound fraction (f(u),) of the esters decreased with lipophilicity. R-N/f(u), for acetylsalicylic acid remained relatively constant as the albumin concentration was increased. However, R-N/f(u), for n-pentanoyl- and n-hexanoylsalicylic acids increased significantly as albumin concentration increased from 0% to 4%. Thus, for the more lipophilic solutes (n-pentanoyl- and n-hexanoylsalicylic acids) the presence of albumin apparently facilitates the uptake of unbound solute relative to acetylsalicylic acid.

Investigation of the antinociceptive efficacy and relative potency of extended duration injectable 3-acylmorphine-6-sulfate prodrugs in rats

This investigation was designed to examine the antinociceptive activity in rats of 3-O-acyl prodrugs of M6S relative to the parent drug, after intravenous and intramuscular injection, using the tail flick latency test of antinociception. M6S, 3-acetylmorphine-6-sulfate (3AcM6S), 3-propionylmorphine-6-sulfate (3PrM6S), 3-butanoylmorphine-6-sulfate (3BuM6S) and 3-heptanoylmorphine-6-sulfate (3HpM6S) were administered by the IV route in a dose of 4.10 mu mol/kg. Relatively high levels of antinociception (>40% Maximum Possible Effect) were achieved following administration of M6S, 3AcM6S and 3PrM6S, whereas insignificant antinociception (<20%MPE) was achieved following administration of 3BuM6S or 3HpM6S. Although the mean duration of action for 3AcM6S (6 h) was longer than for M6S or 3PrM6S (4 h), the mean area (+/- S.E.M.) under the degree of antinociception versus time curve (AUG) for 3AcM6S (151.6 +/- 6.9%MPE h) was not significantly different (p <0.05) from that for M6S (120.8 +/- 32.7%MPE h) or for 3PrM6S (106.0 +/- 21.3%MPE h). The mean ED50 (range) doses for M6S, 3AcM6S and 3PrM6S were calculated to be 4.16 (3.61-4.48), 4.32 (3.55-5.09) and 4.54 (4.21-4.79) mu mol/kg, respectively. Preliminary studies were conducted on potential long-acting formulations containing 8 x ED50 doses of M6S and the 3-acetyl and 3-propionyl esters suspended in soybean oil. These showed that 3PrM6S gave a greater AUC (mean + S.E.M.) (1087.4 +/- 97.4%MPE h) and longer duration of action (20 h) than did M6S (613.1 +/- 155.9%MPE h; 10 h duration) or 3AcM6S (379.3 + 114.2%MPE h: 8 h duration). Further studies are needed to more fully investigate these findings. (C) 1998 Elsevier Science B.V. All rights reserved.

Effect of oral creatine supplementation on near-maximal strength and repeated sets of high-intensity bench press exercise

This study examined the effects of 26 days of oral creatine monohydrate (Cr) supplementation on near-maximal muscular strength, high-intensity bench press performance, and body composition. Eighteen male powerlifters with at least 2 years resistance training experience took part in this 28-day experiment. Pre and postmeasurements (Days 1 and 28) were taken of near-maximal muscular strength, body mass, and % body fat. There were two periods of supplementation Days 2 to 6 and Days 7 to 27. ANOVA and t-tests revealed that Cr supplementation significantly increased body mass and lean body mass with no changes in % body fat. Significant increases in 3-RM strength occurred in both groups, both absolute and relative to body mass; the increases were greater in the Cr group. The change in total repetitions also increased significantly with Cr supplementation both in absolute terms and relative to body mass, while no significant change was seen in the placebo (P) group. Creatine supplementation caused significant changes in the number of BP reps in Sets 1, 4, and 5. No changes occurred in the P group. It appears that 26 days of Cr supplementation significantly improves muscular strength and repeated near-maximal BP performance, and induces changes in body composition.

Effect of load distance on self-selected manual lifting technique

The aim of this research is to determine the effects of constraining the horizontal distance of the feet from the load on the posture adopted at the start of the lift. Kinematic data were collected while each of 24 subjects lifted 3, 6, and 9 kg loads from a starting height 18 cm above the ground. The position of the feet was controlled relative to the load such that the horizontal distance from the hand to the ankle at the start of extension was either 20, 40, or 60 cm. Subjects performed 20 trials in each of six combinations of load and ankle-load distance chosen to provide three sets of equivilent load moment pairs. The initial horizontal distance from the load to the ankle had a large influence on the posture adopted to lift the load. Ankle and knee flexion, in particular, were reduced when the ankle-load distance was smaller, and particularly so when the distance was reduced to 20 cm. Hip flexion was reduced to a smaller extent, while lumbar vertebral flexion remained relatively unchanged. The inclination of the trunk at the start of the lift was unchanged when the ankle-load distance was 60 or 40 cm, but was 10 degrees greater when the load was 20 cm from the ankles, indicating that subjects adopted a posture closer to a stoop when the ankle-load distance was small. Comparison of conditions of equal load moment (but different load mass and ankle-load distance) revealed differences which mirrored the effects of ankle-load distance alone, suggesting that the effects of ankle-load distance on the posture adopted at the start of extension were largely independent of the load moment. While the forces and torques required to lift a load must be to some extent dependent on the load moment, rather than load or ankle-load distance per se, the posture adopted to lift the load is not.

The effect of imposed and self-selected computer monitor height on posture and gaze angle

Objective: The objectives were to determine the postural consequences of varying computer monitor height and to describe self-selected monitor heights and postures. Design: The design involved experimental manipulation of computer monitor height, description of self-selected heights, and measurement of posture and gaze angles. Background. Disagreement exists with regard to the appropriate height of computer monitors. It is known that users alter both head orientation and gaze angle in response to changes in monitor height; however the relative contribution of atlanto-occipital and cervical flexion to the change in head rotation is unknown. No information is available with regard to self-selected monitor heights. Methods. Twelve students performed a tracking task with the monitor placed at three different heights. The subjects then completed eight trials in which monitor height was first self-selected. Sagittal postural and gaze angle data were determined by digitizing markers defining a two-dimensional three-link model of the trunk, cervical spine and head. Results. The 27 degrees change in monitor height imposed was, on average, accommodated by 18 degrees of head inclination and a 9 degrees change in gaze angle relative to the head. The change in head inclination was achieved by a 6 degrees change in trunk inclination, a 4 degrees change in cervical flexion, and a 7 degrees change in atlanto-occipital flexion. The self-selected height varied depending on the initial monitor height and inclination. Conclusions. Self-selected monitor heights were lower than current 'eye-level' recommendations. Lower monitor heights are likely to reduce both visual and musculoskeletal discomfort. Relevance Musculoskeletal and visual discomfort may be reduced by placing computer monitors lower than currently recommended. (C) 1998 Elsevier Science Ltd. All rights reserved.

Effects of egg load on the host-selection behaviour of Helicoverpa armigera (Hubner) (Lepidoptera : Noctuidae)

We examined the effect of age-specific fecundity, mated status, and egg load on host-plant selection, by Helicoverpa armigera under laboratory conditions. The physiological state of a female moth (number of mature eggs produced) greatly influences her host-plant specificity and propensity to oviposit (oviposition motivation). Female moths were less discriminating against cowpea (a low-ranked host) relative to maize (a high-ranked host) as egg load increased. Similarly, increased egg load led to a greater propensity to oviposit on both cowpea and maize. Distribution of oviposition with age of mated females peaked shortly after mating and declined steadily thereafter until death. Most mated females (88%) carried only a single spermatophore, a few females (12%) contained two. The significance of these findings in relation to host-plant selection by H. armigera, and its management, are discussed.

A relative gradient theory for layered materials

It is possible to remedy certain difficulties with the description of short wave length phenomena and interfacial slip in standard models of a laminated material by considering the bending stiffness of the layers. If the couple or moment stresses are assumed to be proportional to the relative deformation gradient, then the bending effect disappears for vanishing interface slip, and the model correctly reduces to an isotropic standard continuum. In earlier Cosserat-type models this was not the case. Laminated materials of the kind considered here occur naturally as layered rock, or at a different scale, in synthetic layered materials and composites. Similarities to the situation in regular dislocation structures with couple stresses, also make these ideas relevant to single slip in crystalline materials. Application of the theory to a one-dimensional model for layered beams demonstrates agreement with exact results at the extremes of zero and infinite interface stiffness. Moreover, comparison with finite element calculations confirm the accuracy of the prediction for intermediate interfacial stiffness.

Rheological behaviour of the mushy zone and its effect on the formation of casting defects during solidification

A new conceptual framework has been developed which explains the formation of shear-related casting defects such as porosity, segregation and tears. The theory relates defect formation to the mechanical behaviour of the partially solidified microstructure when shear stresses are developed during the filling of a casting and by the subsequent feeding processes during solidification. Two transition points, the dendrite coherency point and the maximum packing solid fraction, divide the mushy zone into three regions of different mechanical and feeding behaviours. The response of the mush to shear is related to the presence of these zones during solidification of a casting. The resulting defects are rationalized by considering the governing local shear stress and shear rate, local strength and time available for fluid flow. The design of the casting, the casting process used and the alloy composition all influence the relative importance of shearing on defect formation. (C) 1998 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved.