A multibiomarker approach to environmental assessment

Incorporation of ecologically relevant biomarkers into routine environmental management programs has been advocated as a pragmatic means of linking environmental degradation with its causes. Here, suites of biomarkers, devised to measure molecular damage, developmental abnormality and physiological impairment, were combined with chemical analysis to determine exposure to and the effects of pollution at sites within Southampton Water (UK). Test species included a filter feeder, a grazer, and an omnivore to determine the sensitivity of organisms occupying different trophic levels. Linear regression confirmed a significant association between incidence of intersex in Littorina littorea and tributyltin (TBT) concentrations (R2 = 0.954) and between PAH metabolites in Carcinus maenas urine and PAHs in sediments (R2 = 0.754). Principal component analysis revealed a gradient of detrimental impact to biota from the head to the mouth of the estuary, coincident with high sediment concentrations of heavy metals, PAHs, and biocides. Multidimensional scaling identified C. maenas as the organism most sensitive to contamination. Carboxylesterase activity, metallothionein and total haemolymph protein were the most discriminating biomarkers among sites. This holistic approach to environmental assessment is encouraged as it helps to identify the integrated impact of chemical contamination on organisms and to provide a realistic measure of environmental quality.     

Interruption of response ofDendroctonus brevicomis to attractive pheromone by release of pheromone at several rates and spacings

The number of western pine beetles,Dendroctonus brevicomis, trapped at the center of three 90 × 90-m plots was reduced during a 16-hr period after surrounding an attractive source ofexo-brevicomin, frontalin, and myrcene with 16, 48, or 168 sources of the same attractant. Compounds were released from the center of the plot at 1 mg/16 hr/compound, and from the surrounding sources at 4–280 mg/16 hr/compound. About half of these amounts was released between 1530 hr and 1930 hr, the period of peak beetle flight. No treatment differences were apparent in reduction of catch within the range of release rates and spacings tested. When compounds were released continuously from 168 stations for 17 days, catch at the center of a plot was generally lower than catch before or after this period, but fluctuated daily. More beetles were caught on traps hung on ponderosa pines within a plot and the number of these traps catching beetles was greater when compounds were released from all stations than from only the center station. Beetles caught on traps were attracted into the plots from the surrounding forest, but appeared to be dispersed within the plot when compounds were released from many stations.D. brevicomis attacked at least 91 trees in the plots, of which 25 were killed during two summers.Coleoptera: Scolytidae.Trade names are mentioned solely for information. No endorsement by the U.S. Department of Agriculture is implied.     

Bounded-time fault-tolerant rule-based systems

We introduce two systems concepts: bounded response-time and self-stabilization in the context of rule-based programs. These concepts are essential for the design of rule-based programs that must be highly fault-tolerant and perform in a real-time environment. The mechanical analysis of programs for these two properties will be discussed. We have also applied our techniques to analyze a NASA application.     

Postprandial Lipemia Detects the Effect of Soy Protein on Cardiovascular Disease Risk Compared with the Fasting Lipid Profile

Studies examining the effect of soy protein on cardiovascular disease (CVD) risk factors have not taken advantage of the postprandial state as an adjunct to the fasting lipid profile. The American Heart Association has acknowledged the efficacy of soy protein in reducing CVD risk factors to be limited. We hypothesized that the postprandial state would be more sensitive to any favorable changes associated with consuming soy protein compared with the fasting lipid profile. Furthermore, the presence of isoflavones in soy would enhance this effect. Thirty sedentary males aged 18–30 years were randomly assigned to milk protein (Milk), isoflavone-poor soy (Soy−), or isoflavone-rich soy (Soy+). Usual diets were supplemented with 25 g/day of protein for 28 days. Serum samples were collected before and after supplementation in a fasted state and postprandially at 30, 60, 120, 240, and 360 min after a high-fat, 1,000 kcal shake. Triacylglycerol (TAG), total cholesterol, non-esterified fatty acids, apolipoproteins B-100 and A-I and glucose concentrations were quantified. Fasting concentrations were not different after any protein supplementation. Postprandial TAG and TAG AUC increased after Soy-consumption supporting the postprandial state as a more sensitive indicator of soy ingestion effects on CVD risk factors compared with the fasting lipid profile. Furthermore, the absence of isoflavones in soy protein may have deleterious consequences on purported cardio-protective effects.     

A review of probabilistic analysis in orthopaedic biomechanics

Probabilistic analysis methods are being increasingly applied in the orthopaedics and biomechanics literature to account for uncertainty and variability in subject geometries, properties of various structures, kinematics and joint loading, as well as uncertainty in implant alignment. As a complement to experiments, finite element modelling, and statistical analysis, probabilistic analysis provides a method of characterizing the potential impact of variability in parameters on performance. This paper presents an overview of probabilistic analysis and a review of biomechanics literature utilizing probabilistic methods in structural reliability, kinematics, joint mechanics, musculoskeletal modelling, and patient-specific representations. The aim of this review paper is to demonstrate the wide range of applications of probabilistic methods and to aid researchers and clinicians in better understanding probabilistic analyses.