Phytoremediation of small-scale oil spills in fresh marsh environments: a mesocosm simulation.

Research was conducted to assess the impact of oiling on fresh-marsh plant communities and to test the efficacy of techniques that may be used to enhance the bioremediation of crude oil spills in these environments while minimizing secondary anthropogenic impacts. To emulate field conditions, a mesocosm facility was used that houses 120 mesocosm vessels, each of 200-1 capacity. A five-way factorial treatment arrangement was used that included two substrates (inorganic, organic), two nutrient regimes (fertilized, not fertilized), two aeration levels (substrate aeration, no aeration), three oiling concentrations (0-, 5-, 10-1 m(-2) of South Louisiana Sweet Crude oil), and four vascular plant species (Alternanthera philoxeroides, Panicum hemitomon, Phragmites australis, Sagittaria lancifolia, and an unplanted control). Under the 5- and 10-1 m(-2) oiling concentrations, S. lancifolia displayed a short-term response of increased productivity, whereas P. hemitomon had the highest biomass production and photosynthetic rates at the end of the 18-month experiment. Overall plant growth and productivity, as well as oil degradation, were significantly higher in the inorganic substrate, indicating that biodegradation of oil spills in organic substrates may require a longer time period. Time-released fertilizer also stimulated plant productivity and resulted in higher soil respiratory quotients, suggestive of greater microbial activity, particularly in aerated mesocosms. The amount of oil remaining after 18 months was lowest in aerated and fertilized mesocosms containing either P. hemitomon or S. lancifolia and a substrate of low organic matter content.

Twelve years and counting: California's experience with a statewide Healthy Cities and Community program.

California Healthy Cities and Communities is the longest running statewide program of its kind in the nation. After providing a brief history the authors give an overview of the supporting activities and resources the Program provides to Healthy Cities and Communities initiatives throughout California.

Hempson Industries UK Ltd.. A case study in occupational health services--the solution.

In the February 1996 issue of Occupational Medicine, we published a case study in which the Chief Medical Officer of Hempson Industries, Steve Saunders, had just returned from a European conference where he delivered a well-received keynote presentation on work-related stress disorders. He was delighted with this success and his more general success in establishing a professional and proactive occupational health service during his two years with Hempson Industries. His delight, however, was undermined by his receipt of an internal memorandum from the newly appointed Director of Finance and Administration, Richard Coleman. The letter cited Board colleagues' criticisms of the contribution of OHS to company results, the expense of some services like health screening and recruitment medicals and the seemingly slow and unresponsive behaviour of most OHS staff. It also proposed the out-sourcing of occupational health to Boone Occupational Health Care Inc., an American private occupational health service. We invited readers to reply to the case study, explaining what they would do in Steve's situation. Out of a number replies, four were selected for publication and follow. The author author of the case study, Greg Shaffer, then provides some final comments.

Evaluating the 'Labeled Magnitude Scale' for measuring sensations of taste and smell.

The Labeled Magnitude Scale (LMS) is a semantic scale of perceptual intensity characterized by a quasi-logarithmic spacing of its verbal labels. The LMS had previously been shown to yield psychophysical functions equivalent to magnitude estimation (ME) when gustatory, thermal and nociceptive stimuli were presented and rated together, and the upper bound of the LMS was defined as the 'strongest imaginable oral sensation'. The present study compared the LMS to ME within the more limited contexts of taste and smell. In Experiment 1, subjects used both methods to rate either taste intensity produced by sucrose and NaC1 or odor intensity produced by acetic acid and phenyl ethyl alcohol, with the upper bound of the LMS defined as either the 'strongest imaginable taste' or the 'strongest imaginable odor'. The LMS produced psychophysical functions equivalent to those produced by ME. In, Experiment 2 a new group of subjects used both methods to rate the intensity of three different taste qualities, with the upper bound of the LMS defined as the 'strongest imaginable [sweetness, saltiness, or bitterness]'. In all three cases the LMS produced steeper functions than did ME. Experiment 3 tested the hypothesis that the LMS yields data comparable to ME only when the perceptual domain under study includes painful sensations. This hypothesis was supported when the LMS again produced steeper functions that ME after subjects had been explicitly instructed to omit painful sensations (e.g. the 'burn' of hot peppers) from the concept of 'strongest imaginable taste'. We conclude that the LMS can be used to scale sensations of taste and smell when they are broadly defined, but that it should be modified for use in scaling specific taste (and probably odor) qualities. The implications of these results for theoretical issues related to ME, category-ratio scales and the size of the perceptual range in different sensory modalities are discussed.

Hempson Industries UK Ltd. A case study in occupational health services.

Hempson Industries Inc. is a large (and fictitious), multi-national American owned corporation. Its wholly owned UK subsidiary, Hempson Industries UK Ltd., is a diversified organization with operations dispersed throughout the UK. The UK Chief Medical Officer, Dr. Stephen Saunders, has been with the company for nearly two years and has been proud of his achievements in establishing a professional and proactive in-house occupational health services department. His perceived success, however, has been questioned by some significant recent events.

Increased accuracy and precision of heparin and protamine dosing reduces blood loss and transfusion in patients undergoing primary cardiac operations.

Individual aspects of heparin or protamine dosing have been better controlled than previously as useful tests have become available. Although many variables including drug potency, drug source, and individual patient response have been separately identified, there has not been an attempt to integrate them into a single management strategy. This study was undertaken to learn whether more precise control of drug variables and patient response would affect blood loss and transfusion requirements. Adult patients having primary cardiac operations were prospectively randomized into two groups. A control group received heparin and protamine by conventional methods. The test group received heparin and protamine according to in vitro predictive tests integrating drugs, tests, and patient response. Supplemental protamine was given in this group only if heparin was specifically found by testing. Anticoagulation in all patients was maintained at an activated coagulation time greater than 400 seconds, and any other treatment for bleeding was at the discretion of the clinical team caring for the patients. Testing and treatment for both groups followed routine practice after patient arrival in the intensive care unit. Test patients received slightly more heparin and a markedly lower dose of protamine than the control patients. Testing identified patients with decreased heparin sensitivity (preoperative heparin therapy) and correctly predicted the effective heparin dose. Supplemental protamine was given twice as often to control patients and frequently when no heparin was detectable (retrospectively). Test patients exhibited less 24-hour chest tube drainage (671 ml versus 1298 ml) and fewer patients received transfusion (9/22 versus 18/24) with fewer donor exposures (22/22 versus 101/24). The management strategy used for heparin and protamine added accuracy and precision, which was associated with improved hemostasis. Although the observation is valid, the mechanism or mechanisms are not completely clear. Nevertheless, it is reasonable to apply basic pharmacologic principles and establishment of consistent, predictable protocols that are beneficial. It is against this background that the efficacy of additional drugs or equipment should be assessed. It is quite possible that only marginal if any improvement in hemostasis may be found in patients having primary, uncomplicated cardiac operation with the addition of more costly drugs or equipment.

The effects of combining education and enforcement to reduce tobacco sales to minors. A study of four northern California communities.

OBJECTIVE: To examine the effects of a community education and law enforcement intervention on illegal tobacco sales to minors. DESIGN: A 2-year, before and after trial with retail stores as the unit of analysis. SETTING: Implementation occurred in four suburban California communities with populations of 25,000 to 100,000. PARTICIPANTS: All the retail stores in one intervention community and half the retail stores, randomly selected, in the other three intervention communities (n = 169) were visited by minors aged 14 to 16 years with the intent to purchase tobacco. INTERVENTION: Ongoing community and merchant education and four law enforcement operations were conducted. MAIN OUTCOME MEASURES: Over-the-counter and vending machine sales of tobacco to minors were the primary outcomes. RESULTS: Among a cohort of stores visited by minors at the pretest (n = 104) in June 1988, 71% sold tobacco over the counter and 92% sold tobacco through vending machines. At posttest 2 in May 1990, 24% sold tobacco over the counter and 93% sold tobacco through vending machines. Of the 31 stores issued citations, 16 were followed into the courts where the fines were dismissed or reduced. CONCLUSIONS: Education alone had a limited effect on reducing illegal tobacco sales to minors. It did promote community support for more aggressive enforcement strategies. Education plus enforcement decreased significantly over-the-counter sales; vending machine sales were unaffected by these interventions. The lack of support at the judicial level may temper the effectiveness of enforcement. Legislative remedies addressing judicial obstacles and vending machine sales are needed.

Factors influencing endotoxin concentrations on cotton grown in hot, humid environments: a two year study.

Cotton leaf, bract, fibre from opened bolls, and soil samples were collected weekly during two growing seasons (1984, 1985). Total and Gram negative bacterial populations were determined for each sample. Representative bacterial isolates were identified and endotoxin concentrations determined. For both years total and Gram negative bacterial populations on all sample types remained relatively stable until plant senescence. Afterwards, until plant death by frost, counts for all samples increased dramatically. Enterobacter agglomerans was the predominant species on leaf and bract, whereas the "all other" Gram negative bacterial species classification was the most common on fibre, with E agglomerans a close second. Senescence affected the occurrence of the species isolated. Statistical analysis partitioned by sample type showed strong correlations between endotoxin concentrations and certain bacteriological and environmental variables. The data suggest that in hot, humid environments the concentration of endotoxin on cotton leaf, bract, and fibre may be predicted by total and Gram negative bacterial counts, daily high temperature, and week after plant germination.

Fermentation of carbohydrates under aerobic and anaerobic conditions by intestinal microflora from infants.

To determine how factors involved in infant carbohydrate metabolism could be effectively assayed in vitro, fecal materials from healthy infants were obtained and tested with fermentation mixtures incorporating glucose, fructose, and lactose incubated under aerobic and anaerobic conditions. The amounts of organic acids, hydrogen, carbon dioxide, and methane produced were determined. Principal component analysis indicated that products of the three sugar systems produced very similar factor patterns and, therefore, all three sugars may not be required to adequately characterize intestinal microbial fermentation processes. Moreover, the fermentation processes under aerobic and anaerobic conditions produced essentially identical cluster patterns of the factors from the three sugar systems. Collectively, the results indicated that two sugar systems, glucose and lactose, measured under aerobic fermentation conditions sufficed in accounting for most of the variation among babies.

Free amino acid determination in whole peanut seeds.

A method which circumvents the lengthy procedural steps for sample preparation in the analysis of free amino acids (FAA) in the peanut is described. Sample preparation consists of extracting a full fat meal with a lithium citrate sample buffer for 15 min. The sample is centrifuged and filtered with two Millipore filters in series. The resulting extract is analyzed "as is" for FAA via a physiological amino acid procedure. The method significantly reduces sample preparation time and eliminates the use of hazardous chemicals. It is well adapted to the analysis of large numbers of samples or samples of limited quantity. It should be applicable to the analysis of FAA in other oilseeds.