Introduction of sulphydryl groups into pea vicilin: Formation of intra-and inter-polypeptide disulphide bonds

Site directed mutagenesis was used to introduce two cysteine residues into the hydrophilic regions of the pea vichlin polypeptide previously expressed in Saccharomyces cerevisiae. The mutated polypeptide was expresed and the resultant protein was characterised by sodium dodecyl sulphatepolyacrylamide gel electrophoresis. The presence of both intra- and inter-polypeptide sulphydryl bonds was indicated by bands of different mobility from those of the native polypeptide. The association of mutated vicili polypeptides into disulphide-bonded aggregates within the yeast was not a random process, trimers being the major aggregate produced. When the mutated vicilin was extracted from yeast and purified, random aggregates of the vicilin polypeptide were formed.     

Studies on the solid circulation rate and gas bypassing in spouted fluid-bed with a draft tube

Experiments were performed in a 28.6 cm diameter transparent semicircular vessel with a 9.6 cm diameter draft tube using polyethylene beads (ρ_s = 0.91 g/cm³) and hollow epoxy spheres (ρ_s = 0.21 g/cm³) as the bed material to study the effect of operating conditions, the distributor plate design, and the draft tube inlet configurations on the solid circulation rate and the gas distribution between the downcomer and the draft tube. Solid circulation rate was found to be strongly affected by the design configuration at the bottom of the draft tube and the downcomer, which provided different gas bypassing characteristics and resulted in different amount of aeration in the downcomer region.     

DYNAMIC CHANGES IN THE COMPOSITION AND PHYSICAL BEHAVIOUR OF DISPENSED BEER FOAM

Beer foam generated under conditions encountered at dispense was separated from beer, allowed to collapse and sampled at regular intervals. The yield of collapsed beer foam decreased logarithmically with time. Analysis of the composition of collapsed beer foam fractions over a period of time, considered to be relevant to actual consumption of beer (30 minutes) showed that polypeptide material and isomerised α acids were selectively partitioned in beer foam. The concentration of total polypeptides, soluble polypeptides, isomerised α acids and foam precipitate material in collapsed beer foam, firstly increased with foam collapse time and then approached maximal values. Under these conditions the concentration of polypeptide material and isomerised α acids increased 10–30 fold and 7 fold respectively as compared to beer. No evidence was obtained for the preferential partition of purine nucleosides and free bases in foam (adenosine + deoxyadenosine, guanosine + deoxyguanosine, adenine, guanine and xanthine).     

Responses of Dairy Cows to Exogenous Bovine Growth Hormone Administered During Early Lactation

Bovine growth hormone was administered to eight Holstein cows during two 10-d periods (commencing 20 and 60 d postpartum). Treatments involved daily subcutaneous injection of excipient (control) or of 50 IU growth hormone. Feed intake and yields of milk and milk components were measured during the last 5 d of treatment. In the first injection period, milk yield of treated cows was 6% greater than that of controls (36.2 kg/d). Fat content of milk was increased by treatment with the result that fat yield was elevated by 25%. Protein content was not altered. In the second period, milk yield increased by 12%, but composition of milk was not changed. As a result, milk energy secretion was increased by a similar amount in each treatment period (4.4 versus 4.5 Mcal/d). Feed intake was not changed in either period. During early lactation the ability of cows to increase milk yield in response to exogenous growth hormone may be limited by the supply of glucose for lactose synthesis rather than by ability to mobilize body reserves in support of lactation.     

Predictors of smoking cessation among elderly smokers treated for nicotine dependence

OBJECTIVE: To examine outcomes and predictors of smoking cessation among elderly patients treated for nicotine dependence. DESIGN: Retrospective analysis of patients aged 65-82 who received a nicotine dependence consultation at the Mayo Medical Center between 1 April 1988 and 30 May 1992. Patients were contacted by telephone by a trained interviewer six months after the consultation and were sent a follow-up survey in August 1993. SETTING: Mayo Medical Center, Rochester, Minnesota, United States. SUBJECTS: A total of 613 patients (310 men, 303 women) with a mean age of 69.0 (SD 3.5) years were seen during the study period. MAIN OUTCOME MEASURES: Point prevalence self-reported smoking status. Patients were considered abstinent if they self- reported not smoking (not even a puff) during the seven days before contact. RESULTS: At six-month follow up, 24.8% of the 613 patients reported abstinence from smoking. On multivariate analysis, smoking abstinence was more likely if patients were hospitalised at the time of the consultation, married to a non-smoking spouse, very motivated to stop smoking, and reported their longest time of previous abstinence to be less than a day or more than a month. The response rate to the mailed follow-up survey was 69.9% (429 of 613). The mean duration of follow up was 40.0 +/- 13.2 months following the consultation. Of the 429 patients, 103 (24.0%) reported abstinence from smoking and 326 (76.0%) were smoking at six-month follow up. Patients who reported abstinence at six months had a higher cessation rate at the last follow up (76.0%) compared with patients who were smoking at six-month follow up (33.0%, P < 0.001). For patients who were not smoking at six months, no factors were found to significantly predict abstinence at last follow up. For patients who were smoking at six months, factors associated with smoking cessation at last follow up were: more than a year as the longest time off cigarettes before the consultation; counsellor rating of less severe nicotine dependence; and older age at first regular smoking. CONCLUSIONS: Several predictors of smoking cessation were identified in this study which may be useful for tailoring smoking interventions for the elderly.


     

Levels and distribution of polybrominated diphenyl ethers in water, surface sediments, and bivalves from the San Francisco Estuary

Polybrominated diphenyl ethers (PBDEs) were found in water, surface sediments, and bivalve samples that were collected from the San Francisco Estuary in 2002. sigmaPBDE concentrations in water samples ranged from 3 to 513 pg/ L, with the highest concentrations found in the Lower South Bay (range 103-513 pg/L) region, which receives approximately 26% of the Estuary's wastewater treatment plant effluents. The sigmaPBDEs in sediments ranged from below detection limits to 212 ng/g dry wt, with the highest concentration found at a South Bay station (212 ng/g dry wt), which was up to 3 orders of magnitude higher than other stations. The sigmaPBDE concentrations ranged from 9 to 64 ng/g dry wt in oysters (Crassostrea gigas), from 13 to 47 ng/g dry wt in mussels (Mytilus californianus), and from 85 to 106 ng/g dry wt in clams (Corbicula fluminea). Only three PBDE congeners were detected in bivalves, BDE-47, BDE-99, and BOE-100; these are the most bioaccumulative congeners from the commercial Penta-BDE mixture.     

EXTRUDED SORGHUM AS A BREWING RAW MATERIAL

Small scale mashes (50 g total grist) with grists containing up to 50% by weight of extruded whole sorghum produced worts of high extract yield and low viscosity. Increasing the proportion of extruded sorghum in the grist resulted in decreasing wort filtration volume, total nitrogen and free amino nitrogen content. The wort filtration behaviour of mashes containing sorghum extruded at 175°C was superior to that of mashes containing sorghum extruded at 165°C or 185°C. The results from such small scale mashing experiments suggested that extruded sorghum compared favourably to extruded barley and extruded wheat as a brewing adjunct. Worts and beers were produced on a pilot brewery scale (100 1) from grists comprising 70% malt + 30% extruded sorghum and 100% malt under isothermal infusion mashing conditions. Mashes containing sorghum extruded at 175°C showed comparable wort filtration behaviour to that of the all malt control mash whereas mashes containing sorghum extruded at 165°C or 185°C showed poor wort filtration behaviour. Worts produced from grists containing extruded sorghum fermented more quickly than the control wort and attained lower values of final gravity. The resulting beers were filtered without difficulty. Beers produced from grists containing extruded sorghum contained lower levels of total nitrogen and free amino nitrogen compared to the control beer consistent with extruded sorghum contributing little or no nitrogenous material to the wort and beer. Beers brewed from grists containing extruded sorghum were of sound flavour and showed reasonable foam stability behaviour.     

Relationship between measures of effort and job performance.

Effort expended and job performance are considered to be different, although not independent, constructs in the industrial environment. The relationship between these 2 variables was investigated using the multitrait-multimethod and multitrait-multirater approaches. 202 engineers completed self-ratings and were rated by their supervisors (n = 41), using global and dimensional rating methods. Convergent validity was found for the measures of effort and the measures of performance, but only the measures of performance demonstrated discriminant validity when compared with the measures of effort. Raters demonstrated convergent validity for each variable, but only some discriminant validity on the performance measures. Implications of the results are discussed in terms of appropriateness of the dimensional measure of effort. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Wheat-bug damage in New Zealand wheats: The feeding mechanism of nysius huttoni and its effect on the morphological and physiological development of wheat

Adult Nysius huttoni White were placed in separate cages containing cultivars Rongotea and Karamu at the late anthesis, watery ripe and milky ripe stages of development. Between 84 and 99 % of the matured kernels were injured with the characteristic visible markings of bug-damaged wheat. All the samples contained strong wheat-bug proteinase activity as shown by the incubated SDS-sedimentation test and the disappearance of HMW glutenin subunits from electrophoretograms. Grain infested at late anthesis was most severely affected with shrivelled kernels, high screenings, protein, free amino acids and α-amylase, and low kernel weight, germination capacity and carbohydrate content. Grain infested at the watery ripe and milky ripe stages had values for the above properties closer to uninfested control wheat values. It was suggested that N huttoni sucked sap from lateral sieve tubes in the wheat ovary at late anthesis causing severe disruption to physiological development of the grain. Two commercial lines of wheat showed some characteristics of this effect.     

A model of passive thermal nondestructive evaluation of composite laminates

A numerical model of passive thermal nondestructive evaluation (NDE) of composite laminates was developed. This model, based on a transient, three-dimensional, finite difference solution to the heat conduction equations, can be used to characterize in-plane defects in the laminates and to predict the laminate response to the thermal test. The model was experimentally verified using two material systems. A parametric study was then conducted to ascertain which variables were critical to the success of passive thermal NDE, and how flaw resolution might be improved.