Sourcing faecal pollution: a combination of library-dependent and library-independent methods to identify human faecal pollution in non-sewered catchments

Library-dependent (LD) (biochemical fingerprinting of Escherichia coli and enterococci) and library-independent (LI) (PCR detection of human-specific biomarkers) methods were used to detect human faecal pollution in three non-sewered catchments. In all, 550 E. coli isolates and 700 enterococci isolates were biochemically fingerprinted from 18 water samples and compared with metabolic fingerprint libraries of 4508 E. coli and 4833 enterococci isolates. E. coli fingerprints identified human unique biochemical phenotypes (BPTs) in nine out of 18 water samples; similarly, enterococci fingerprints identified human faecal pollution in 10 water samples. Seven samples were tested by PCR for the detection of biomarkers. Human-specific HF134 Bacteroides and enterococci surface protein (esp) biomarkers were detected in five samples. Four samples were also positive for HF183 Bacteroides biomarker. The combination of biomarkers detected human faecal pollution in six out of seven water samples. Of the seven samples analysed for both the indicators/markers, at least one indicator/marker was detected in every sample. Four of the seven PCR-positive samples were also positive for one of the human-specific E. coli or enterococci BPTs. The results indicated human faecal pollution in the studied sub-catchments after storm events. LD and LI methods used in this study complimented each other and provided additional information regarding the polluting sources when one method failed to detect human faecal pollution. Therefore, it is recommended that a combination of methods should be used to identify the source(s) of faecal pollution where possible.     

The emerging conceptualization of groups as information processors.

A selective review of research highlights the emerging view of groups as information processors. In this review, the authors include research on processing objectives, attention, encoding, storage, retrieval, processing response, feedback, and learning in small interacting task groups. The groups as information processors perspective underscores several characteristic dimensions of variability in group performance of cognitive tasks, namely, commonality—uniqueness of information, convergence–diversity of ideas, accentuation–attenuation of cognitive processes, and belongingness–distinctiveness of members. A combination of contributions framework provides an additional conceptualization of information processing in groups. The authors also address implications, caveats, and questions for future research and theory regarding groups as information processors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Theory and research on small groups.

Review of book: R. Scott Tindale et. al (Eds.) Theory and Research on Small Groups. New York: Plenum Press. 1998, 277 pp. Reviewed by Mark F. Stasson, Michael J. Markus, and Jason W. Hart. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Individual and group reward allocation decisions in two situational contexts: Effects of relative need and performance.

Assessed the effects of relative need and performance information on individual and group reward allocation decisions in 2 situational contexts. 320 male undergraduates, as individuals or in 4-person groups, were asked to divide a reward between either 2 workers who had performed a given task (work situation) or 2 students who had qualified for a particular scholarship. Performance and need information (high vs low levels) about each target person were presented. Performance and need information affected allocation decisions differently in the 2 situations. Individual decisions were affected by the need information to a greater degree than were group decisions, but only in the work situation. A social decision scheme analysis of the group decision process showed that the individual/group difference found for the work situation could be accounted for by the plurality/majority decision rule used by groups. Results are discussed in relation to reward allocation and group decision making in general. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assembly bonus effect or typical group performance? A comment on Michaelsen, Watson, and Black (1989).

L. K. Michaelsen et al (see record 1990-04483-001) argue that, by using experienced groups working on relevant tasks with real rewards, an assembly bonus effect (group performance that is better than the performance of any individual group member or any combination of individual member efforts [B. E. Collins and H. Guetzkow, 1964]) was demonstrated. Using computer simulations based on the Michaelsen et al findings, the authors argue that it is highly unlikely that an assembly bonus effect was found and that the results are typical of those obtained in standard laboratory experiments on group problem solving. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Current equipment for mechanical oil extraction

This paper describes the range of screw presses available to processors and lists technical features which have been brought to the authors’ attention. The range of equipment is discussed manufacturer by manufacturer, starting with the smallest available equipment and progressing to the largest. The manufacturer’s rated capacity is used as the measure of size. As most manufacturers prepare their information in a variety of ways, this paper, in an attempt to compare machines on a uniform basis, has based all throughputs on 2,000 lb/ton, with meats from “whole cottonseed” (with an assumed hull content of 8–10%) at 24 hr/day. For this reason, the figures given in this paper will not always agree with figures published by manufactures. Throughputs on other material should be discussed with the equipment manufacturers, who generally have available data on most commercially processed oil-bearing seeds.     

Estimation of biogenic amines in foods

Biogenic amines in foods have been proposed as initiators of dietary-induced migraine. Studies of levels of 2-phenylethylamine, p-tyramine and the diamines histamine, putrescine and cadaverine in a number of Australian and other foods were made by ion exchange and high pressure liquid chromatographic methods. In the latter method the amines were chromatographed as their fluorescamine derivatives. The use of such derivatives also enabled confirmation of the identity of the amine by field desorption-mass spectrometry. Extraction procedures were devised to give satisfactory recoveries of amines in foods and to overcome problems associated with the binding of amines to other food constituents.     

Liver blood flow: non-invasive estimation using a gamma camera.

A non-invasive radioisotope technique for the measurement of total liver blood flow (TBF) is described. The method requires the use of two intravenously administered tracers, 99mTc (technetium 99m) human serum albumin (HSA) and 99mTc colloid. Computer analysis of first-pass time activity curves for HSA for liver and lung tissues yields values for the arterial and portal contributions to liver blood flow, from which TBF can be determined. These values are then corrected for attenuation using the images of the colloid distribution. The use of the method is illustrated in 17 subjects. Assumptions, limitations and possible applications of the technique are discussed.     

Effect of relative humidity and incubation time on the O-methylation of chlorophenols in fibreboard by Paecilomyces variotii

The effect of relative humidity and incubation time on the extent of O-methylation of 2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol and pentachlorophenol by Paecilomyces variotii as studied ith fibreboard as the groth medium. Over a 10-eek incubation period the yields of 2,4,6-trichloroanisole and 2,3,4,6-tetrachloroanisole ere greater the higher the relative humidity; hoever, the degree of methylation of pentachlorophenol as almost negligible. At 30°C and 98% relative humidity, the methylation of the tri- and tetrachlorophenols ceased after the fourth eek; maximum chloroanisole concentrations ere observed at this time. The results indicated that methylation as the principal mechanism by hich P variotii detoxified 2,4,6-trichlorophenol and 2,3,4,6-tetrachlorophenol in fibreboard.     

Asymmetrical social influence in freely interacting groups: A test of three models.

Using freely interacting mock juries, this study tested the predictions of 3 different models of social influence: social impact theory, the other–total ratio, and the social influence model. All 3 models use faction size as the basis for their predictions. On the basis of the predeliberation verdict preferences of 879 female students, groups were composed using all possible nonunanimous verdict compositions (e.g., 5 members for "guilty," 1 for "not guilty," etc.) for 3-, 4-, 5-, and 6-person groups. Each group deliberated and reached a group verdict for an attempted murder case, and postdeliberation verdict and probability-of-guilt judgments were obtained from the individual group members. The results showed that faction size affected the relative amount of both majority and minority influence. However, faction size effects differed substantially depending on the verdict supported by the particular faction. Thus, the predictions of even the most accurate model could presumably be improved by modifications allowing for additional interpersonal factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)