High-precision measurement of variations in calcium isotope ratios in urine by multiple collector inductively coupled plasma mass spectrometry

We describe a new chemical separation method to isolate Ca from other matrix elements in biological samples, developed with the long-term goal of making high-precision measurement of natural stable Ca isotope variations a clinically applicable tool to assess bone mineral balance. A new two-column procedure utilizing HBr achieves the purity required to accurately and precisely measure two Ca isotope ratios ((44)Ca/(42)Ca and (44)Ca/(43)Ca) on a Neptune multiple collector inductively coupled plasma mass spectrometer (MC-ICPMS) in urine. Purification requirements for Sr, Ti, and K (Ca/Sr > 10?000; Ca/Ti > 10?000?000; and Ca/K > 10) were determined by addition of these elements to Ca standards of known isotopic composition. Accuracy was determined by (1) comparing Ca isotope results for samples and standards to published data obtained using thermal ionization mass spectrometry (TIMS), (2) adding a Ca standard of known isotopic composition to a urine sample purified of Ca, and (3) analyzing mixtures of urine samples and standards in varying proportions. The accuracy and precision of δ(44/42)Ca measurements of purified samples containing 25 μg of Ca can be determined with typical errors less than ±0.2‰ (2σ).     

The influence of dairy salts on nanofiltration membrane charge

The nanofiltration of dairy ultrafiltration permeate can be used to produce a concentrated lactose product that is reduced in unwanted monovalent salts. In this paper, the surface charge of three nanofiltration membranes commonly used for such a purpose is examined. The focus is the impact of multivalent anions, notably phosphate and citrate, upon the surface charge of the membranes within a ternary system of potassium and calcium chloride. It was shown that these multivalent anions can influence the membrane charge through interactions with calcium, even though they are unlikely to adsorb to the membrane surface. Specifically, both phosphate and citrate can form soluble charged species with the calcium ions, reducing the net Ca²⁺ concentration and hence the overall effect of calcium on the membrane. This ion interaction effect becomes more dominant at higher pH values, due to the greater tendency of calcium to interact with either phosphate or citrate at higher pH.     

The development of an expert system for online company database selection

Abstract: This paper describes a project undertaken in the Department of Information and Library Studies at Loughborough University to develop a prototype expert system to assist with the selection of online business databases for British company information. The project was funded by the British Library Research and Development Department for 21 months, commencing July 1990. Specific phases of the project comprised a literature survey, knowledge acquisition involving experts in online searching, the design and development of a system called CIDA (Company Information Database Adviser) which was some 4Mb in size, and a user evaluation of this prototype. The study demonstrated that expertise in business database selection can successfully be distilled into a number of rules which can be applied by an expert system.     

Effects of acidity,calcium, and aluminium on fish survival and productivity—a review

Fish survival, growth and productivity are dependent on both biological and environmental factors. The latter can be distinguished as edaphic (which includes water quality) and morphometric (which includes lake and stream morphology). Climatic factors are relatively less significant in temperate waters, except over a long time scale, or over wide geographic areas. In the conditions characteristic of acid lakes— low pH, low calcium and high aluminium concentrations—survival may be reduced, growth may be affected and, consequently, productivity will be low. In spite of inconsistencies in the literature, it can be shown that at low pH (? 4.5), a limiting concentration of calcium is about 1 mg litre^?1 and aluminium can have adverse effects at 250 μg litre^?1 within a limited range of pH. These three factors appear to interact. Taking age specific fecundity of adults and survival of eggs and fry, it is possible to predict the limiting conditions for maintenance, growth or decline of a fish population. At pH 4.5 and calcium < 0.8 mg litre^?1 it may be expected that many lakes will be fishless.     

Designing and evaluating a crew resource management training for manufacturing industries

This article presents the evaluation of crew resource management (CRM) training specifically designed for employees within manufacturing industries. The central objective of this training program was to improve teamwork, communication, and stress management skills as well as to increase the workers' situational awareness of potential errors that can occur during the manufacturing process. Eighty employees, all of whom were working in a production unit for gearbox manufacturing, participated in the training program in this study. Effectiveness of the CRM training course was evaluated. The results showed a significant improvement in a wide range of CRM‐relevant categories, especially in teamwork‐related skills, in addition to an increase in the workers' situational awareness after the training program. When comparing the data regarding human error occurring in gear production that were derived from the trained group and a control group, mixed results were produced. Based on the results, it can be stated that CRM training, which was originally developed for the aviation industry, can be transferred to the manufacturing industry. © 2010 Wiley Periodicals, Inc.     

Prevalence and numbers of coliphages and Campylobacter jejuni bacteriophages in New Zealand foods

Vegetable samples were tested for the presence of coliphages. None of the 55 samples contained these phages at concentrations greater than 10 g(-1) (the limit of detection). Spiking and recovery experiments indicated that the method was efficient at detecting coliphage T4 added to the food, and so it was concluded that phage titres were not being falsely underestimated. In addition 51 samples of chicken skin from retail portions were tested for the presence and numbers of coliphages and for presence only of Campylobacter jejuni phages. Coliphages were isolated from 46 samples (90.2% positive), at up to 2570 PFU 10 g sample(-1) but no C. jejuni phages were isolated. Several other methods were used to isolate C. jejuni phages from retail chicken but none was successful. However, when pooled whole chicken rinses from 39 flocks were tested for the presence of C. jejuni phages, 11 (28.2%) of the flocks were positive. It is possible that phages present on birds at the start of processing were either inactivated or simply diluted out during spin chilling. These data add to the body of information indicating that phages can readily be isolated from certain foods and indicate that consumers are exposed to them on a regular basis.     

Plant-soil distribution of potentially toxic elements in response to elevated atmospheric CO2

The distribution of contaminant elements within ecosystems is an environmental concern because of these elements' potential toxicity to animals and plants and their ability to hinder microbial ecosystem services. As with nutrients, contaminants are cycled within and through ecosystems. Elevated atmospheric CO2 generally increases plant productivity and alters nutrient element cycling, but whether CO2 causes similar effects on the cycling of contaminant elements is unknown. Here we show that 11 years of experimental CO2 enrichment in a sandy soil with low organic matter content causes plants to accumulate contaminants in plant biomass, with declines in the extractable contaminant element pools in surface soils. These results indicate that CO2 alters the distribution of contaminant elements in ecosystems, with plant element accumulation and declining soil availability both likely explained by the CO2 stimulation of plant biomass. Our results highlight the interdependence of element cycles and the importance of taking a broad view of the periodic table when the effects of global environmental change on ecosystem biogeochemistry are considered.     

Intelligence: Knowns and unknowns.

Presents findings of a task force established by the American Psychological Association to report on the issues of what is known and unknown about intelligence. Significant conceptualizations of intelligence are reviewed, including the psychometric approach, theories of multiple forms of intelligence, cultural variations, theories of developmental progressions, and biological approaches. The meaning of intelligence test scores, what they predict, and how well they predict intelligence is discussed. Genetic factors and intelligence, focusing on individual differences, conventional IQ tests, and other tests intended to measure cognitive ability, are described. Environmental factors such as social and biological variables are discussed, and sex and ethnic group differences are addressed. Recommendations for future research are presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of gazing at the camera during a video link on recall

The impact of looking into the camera during a presentation over a video link (resulting in the perception of mutual gaze) on information recall was investigated. In a face-to-face context mutual gaze has been shown to facilitate the encoding and subsequent recall of information [Fry, R., Smith, G.F., 1975. The effects of feedback and eye contact on performance of a digit-coding task. J. Soc. Psychol. 96, 145-146; Otteson, J.D., Otteson, C.R., 1980. Effect of teacher's gaze on children's story recall. Percept. Motor Skill. 50, 35-42; Sherwood, J.V., 1988. Facilitative effects of gaze upon learning. Percept. Motor Skill. 64 (3 Part 2), 1275-1278]. One explanation for these findings is that gaze acts as an arousal stimulus, which increases attentional focus and therefore enhances memory [Kelley, D.H., Gorham, J., 1988. Effects of immediacy on recall of information. Commun. Edu. 37(3), 198-207]. Two studies were conducted in order to test whether gazing at the camera during video-mediated presentations resulted in similar benefits as mutual gaze in a face-to-face context. In study 1 a confederate presented information about two fictitious soap products. In one condition, the confederate gazed at the camera for 30% of the presentation, therefore giving the participants the impression that he was gazing in their direction. In the other condition the confederate did not gaze at the camera. Participants viewed the sales presentations from both conditions. In the condition where gaze was directed at the camera, participants recalled significantly more information about the sales presentation. Study 2 employed the same pre-recorded sales presentations used in study 1, however they were delivered to the participants under audio-only conditions (therefore, the image was switched off). Results from study 2 indicated no recall differences between the two conditions. Findings from these studies would seem to indicate that the perception of gaze aversion over a video link (a consequence of the salesman not looking into the camera) has a negative impact on information recall. This has practical implications for video-mediated presentations. In a distance learning environment lecturers could be advised to look into the camera in order to promote more efficient learning in students.