Determination of soya proteins in food using an enzyme-linked immunosorbent assay procedure

Classical immunoanalytical techniques are based on native antigens and their precipitation with specific antibodies: they are not very appropriate for the investigation of processed denatured mixtures. This report describes an immunoassay based on the more recent but well-established enzyme-linked immunosorbent assay (ELISA) procedure, which in this case is specific for soya proteins that have been solubilised in urea and then ?renatured’? by removing or diluting the denaturant. Levels of soya protein 100 g^?1 total protein (nominally 100%) were determined with 34 commercial soya products, using a standard reference antigen. Normal expected levels were observed with flours (average 107%) and isolates (108%), while results with concentrates (82%) and texturates (79%) were somewhat lower. Some specialised products gave little or no response, presumably because they are hydrolysed. Meat, milk, egg, wheat and field bean proteins displayed negligible interference. These preliminary results suggest that the ELISA procedure will provide a convenient general method for the qualitative characterisation and quantitative estimation of individual proteins in food products even after severe processing; it seems more attractive than many other methods reported. Immunoassay is capable of large numbers of inexpensive but sophisticated determinations of specific food components. The food analyst should regard ELISA (for the determination in situ of specific antigens in mixtures) as a powerful technique complementary to classical chromatographic and electrophoretic methods which depend on separation before determination.     

Great Lakes Beginning-of-Month Water Levels and Monthly Rates of Change of Storage

Time series of beginning-of-month water levels and rates of change of lake storage were determined for each of the Great Lakes and Lake St. Clair for 1941-1975 period. The Thiessen polygon procedure was used to compute the beginning-of-month levels because it provides more representative over-all lake levels than straight averaging and requires minimum subjectivity. The effect of crustal movement on the rate of change of lake storage was investigated and found to be negligible. A gage density analysis showed good agreement between various size gage networks with the maximum deviation between networks decreasing with increasing gage density. Thiessen polygon weighting factors are presented for the current gage networks to enable future extension of the time series.     

Recovery of valuable metals from acid mine drainage by selective titration

Acid solutions associated with the non-ferrous metal mining industry contain economically significant amounts of heavy metals including Al, Cu, Zn, Mn and Mg. These metals are usually rendered non-recoverable by the conventional neutralization treatment technologies used to create environmentally acceptable discharge. Acid solutions which are generated as the result of the mining of a porphyry Cu deposit were subjected to laboratory scale titration sequences. When these base titrations involve appropriate initial additions of an oxidizing agent and the sulfide ion, better than 85% of the dissolved metals are sequentially separated from the solution in distinct pH regimes. These precipitates include the sulfides of Cu and Zn and the hydroxides of Fe, Al, Mn and Mg. The possibility of using specific conductance and ionic strength of the solution as a means of determining appropriate endpoints in the titration sequence is discussed. These sequential metal separations provide a means for the recovery of a substantial amount of the cost of generating an environmentally acceptable discharge.     

Accident proneness: A conceptual analysis

The concept of accident proneness has had a long and controversial history. An attempt is made both to demonstrate the nature of this controversy and to investigate the reasons for its occurrence. Two factors are identified. One is the conceptual confusion surrounding the meaning of the concept. This is accounted for by the fact that accident proneness is defined by exclusion. The second factor is the repetitive use of statistical techniques which have been shown to be equivocal. An alternative approach to individual differences in accident involvement is advocated. This approach cuts through the conceptual confusion and is less susceptible to the criticisms which have been levelled against the traditional statistical techniques.     

The volatiles of off-flavoured unblanched green peas (Pisum sativum)

Volatile extracts of moderately off-flavoured frozen peas, prepared by vacuum sublimation followed by concentration of the sublimate by low temperature vacuum distillation, were examined by gas chromatography, silica gel chromatography and combined gas chromatography–mass spectrometry. The constituents identified included alcohols (29), carbonyls (31), esters (12), hydrocarbons (19), terpenes (6) and 3-alkyl-2-methoxypyrazines (3). Olfactory monitoring of the gas chromatographic column effluent indicated that most of the strong odours were associated with alkanals, alk-2-enals, alka-2,4- and 2,6-dienals, octa-3,5-dien-2-ones, 3-alkyl-2-methoxypyrazines and hexanol. However, no compound which, by itself, could account for the “hay-like” off-flavour of peas was evident. The off-flavour is considered to be complex and composed largely of the more odorous unsaturated carbonyls derived from the enzymic breakdown of the unsaturated pea lipids. The volatiles of pea shells similarly examined were found to contain many of the compounds present in peas.     

The Segregated Storage Problem: Some Properties and an Effective Heuristic

The segregated storage problem is formulated as an integer programming problem. Some special cases are shown to reduce to ordinary assignment problems. A special property of the integer formulation is used to develop a new heuristic procedure which produces near optimal solutions and which can be used as a tight bound in branch and bound procedures. Computational comparisons with heuristics proposed by other authors indicate this method to be superior in solving large problems.     

Fairness of psychological tests: Implications of four definitions for selection utility and minority hiring.

Expected utility losses in moving from T. A. Cleary's (1968), R. L. Thorndike's (1971), and R. B. Darlington's (1971) Definition 3 selection fairness models to the quota model were assessed on an interval scale for various combinations of validity, minority base rate, and selection ratio. Expected changes in minority selection ratios across conditions were also determined. Utility losses were shown to be large enough to be of practical significance in many commonly occurring selection situations, although when considered as a percentage of maximum value, utilities remained quite high for the Thorndike and Darlington models. Increases in minority selection ratios across models were more striking than utility losses. Because no accepted method for converting minority selection ratios to utility units exists, and in light of the fact that the legal status of all 4 models is as yet unclear, it is concluded that each personnel researcher or organization must consider the trade-off between utility and the minority selection ratio subjectively and choose the model of selection fairness most consistent with his or its values. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relative Accuracy of Connecting Channel Discharge Data with Application to Great Lakes Studies

The flows in the Great Lakes connecting channels are a major component in the water balance of the Great Lakes Basin. The increased emphasis on Great Lakes water quality and quantity requires an assessment of the accuracy of both measured and computed connecting channel discharge data. In this study, the standard error of typical discharge measurements was found to be approximately 3 to 5 percent, depending upon the number of panels used in the cross section. Mesurement sets were found to have a practical limit of about 25 measurements. The standard error of a set of measurements was found to be on the order of 1 percent. The procedure used to compute the published flows of the Niagara River was found to have an apparent bias of about 2 percent on the high side. It is recommended that the published Niagara River flows be adjusted prior to use in detailed water balance studies.     

The Golden Flea Award.

Comments on the original article by R. C. Atkinson (see record 1977-28549-001), which discusses psychology's progress during the last quarter century and its potential for significant scientific advances in the future. In the interests of balanced discussion, this letter brings attention to a lesser known award-the Golden Flea Award-that is given annually for the year's most nit-picking criticism of American science. It is argued that carrying the game to our political critics may be an approach whose time is due. (PsycINFO Database Record (c) 2010 APA, all rights reserved)