Adverse environmental impact: a consultant's perspective

Environmental consultants are in a unique position to address the practical aspects of a working definition of "adverse environmental impact" (AEI) within Section 316(b) of the Clean Water Act. In our work with the electric utility industry, attorneys, and regulatory agencies, we have encountered numerous and sometimes conflicting interpretations as to what constitutes AEI. In our over 30 years of experience, we have applied most of the approaches suggested for addressing this issue, including biostatistical methods, trend analysis, time series methods, conditional mortality rate models, stock-recruitment models, equivalent adult models, and ecosystem models. In our experience, the paradigm most helpful in bringing about agreement among stakeholders is to (1) create a model of operating scenarios, (2) use empirical data from on-site studies to parameterize the model, (3) convert losses by life stage to equivalent adult losses, (4) convert equivalent adult losses to economic value, and (5) compare scenarios on an economic basis.     

Inter- and intra-individual variation in resting oxygen consumption in post-larvae of the giant freshwater prawn,Macrobrachium rosenbergii (De Man)

In a study of the factors that influence metabolic rate in the giant freshwater prawn Macrobrachium rosenbergii, resting oxygen consumption (ROC) was measured in 90 post-larvae ranging in size from 0.1 to 2.8 g. As in many other animal species, ROC was strongly negatively related to body weight. A stressful event (anaesthesia with or without tagging) caused a sharp increase in the ROC that disappeared over a time scale of hours. As has been demonstrated for other species of crustaceans, ROC was highest in prawns in the pre-moult stage. Individual differences in ROC among prawns handled in the same way and in the same moult stage persisted over a period of hours, but not over days. It remains unclear, therefore, whether early differences in resting metabolic rate can explain the conspicuous differences in growth rate that are found in this species during the first few weeks of life and that profoundly influence subsequent life history events.     

A functional comparison of ovine and porcine trypsins

Trypsin was isolated from ovine and porcine pancreas using affinity chromatography on immobilized p-aminobenzamidine. Molecular masses of the two proteins were 23900 and 23435 Da, determined by matrix-assisted laser desorption/ionisation time of flight (MALDI-TOF) mass spectrometry. The purified trypsins were compared using the kinetic properties K(m) and k(cat) which were determined at pH 8.0 and between 25 and 55 degrees C. Comparison of the Michaelis constants for ovine and porcine trypsins toward N-alpha-benzoyl-arginine-p-nitroanilide (BapNA) indicated that ovine trypsin had higher affinity for this substrate than the porcine enzyme. The rates of the reactions catalysed by the two enzymes correlated strongly over the range of temperatures and substrate concentrations tested, as did the k(cat) values. The specific activity of ovine trypsin for BapNA was, on average, approximately 10% higher than that of the porcine enzyme over the range of conditions tested. Porcine trypsin was less susceptible to denaturation at low pH or high temperature than was ovine trypsin. Porcine and ovine trypsin produced seven identically sized fragments from auto-catalytic hydrolysis. Proposed regions of identity between ovine and porcine trypsins were I(54)-K(77), L(98)-R(107), S(134)-K(178) and N(209)-K(116). Hydrolysis of beta-lactoglobulin, egg white lysozyme or casein by ovine or porcine trypsin yielded virtually identical patterns of fragments although the rate at which fragments were produced, in the case of beta-lactoglobulin, differed between the two enzymes. On balance the two enzymes appear to be functionally identical in their action.     

Lack of mannose-binding lectin-A enhances survival in a mouse model of acute septic peritonitis

The mannose-binding lectin (MBL) (also known as the mannose-binding protein) is a serum protein that plays a role as an "ante-antibody" in innate immunity. In man, MBL is encoded by a single gene, whereas in mice there are two homologous proteins, MBL-A and MBL-C. In order to evaluate the relative roles of these two forms of MBL, we created MBL-A null mice that were MBL-C sufficient. We found MBL-A null mice had enhanced survival in a septic peritonitis model compared to wild-type mice and complement 3 null mice at 24 h, 48 h and 10 d (P < 0.05). Reconstitution of these mice with human MBL reversed the phenotype. Surviving mice had significantly decreased TNF-alpha and IL-6 levels in the blood and peritoneal cavity (P < 0.01). In vitro studies indicate that bacteria opsonized with MBL-A-deficient serum induced significantly less cytokine by peritoneal macrophages compared to those with wild-type serum. Our results indicate that MBL-A is a modulator of inflammation in vivo and in vitro in the mouse and that the role of MBL may extend beyond its role as an opsonin.     

Construction of optimal quality control for oligo arrays

MOTIVATION: Oligo arrays are important experimental tools for the high throughput measurement of gene expression levels. During production of oligo arrays, it is important to identify any faulty manufacturing step. RESULTS: We describe a practical algorithm for the construction of optimal quality control designs that identify any faulty manufacturing step. The algorithm uses hillclimbing, a search technique from combinatorial optimization. We also present the results of using this algorithm on all practical quality control design sizes. AVAILABILITY: On request from the authors.