Environmental risk: Management strategies in the developing world

This paper describes a heuristic model which helps to relate a developing nation's environmental risk to the level of sophistication appropriate in adjusting management strategy to dealing with environmental hazards. The model takes into account three factors: the degree of risk, the stage of economic growth, and the sophistication of adjustment. The interrelationship of these factors is examined, and the role of international cooperation in establishing strategies is outlined.     

THE LETHAL AND SUB LETHAL EFFECTS OF A ZIRCONIUM PROCESS EFFLUENT ON JUVENILE SALMONIDS1

ABSTRACT: An effluent (ZPE), with high concentrations of ammonia was compared with solutions of ammonium chloride in both lethal and sublethal tests. The ZPE was more toxic than were solutions of ammonium chloride in acute toxicity tests, although ammonia was shown to be the major toxicant. The secondary toxicants present in the effluent were not identified. Growth was used as a sublethal test parameter and ZPE was again more toxic than ammonium chloride solutions at the same ammonia concentration. Concentrations of ammonia less than 3 mg/liter in ammonium chloride solutions actually stimulated the growth of juvenile chinook salmon. Concentrations of ZPE in the river at extreme low river flow could have sublethal effects on juvenile salmonids below the outfall.     

ZONES OF NITRIFICATION1

ABSTRACT: This paper advances the hypothesis that nitrification exists in shallow streams as a result of surface activity and in estuaries due to growth in the water phase. Between these zones no significant levels of nitrification occur. Field measurements of ammonia, nitrite and nitrate nitrogen, enumerations of Nitrosomonas and Nitrobacter, and respirometry on two small streams and two moderately large rivers are presented. The appropriate mathematical models to describe nitrification must be based on the mechanisms involved - bacterial growth kinetics for estuaries and zero kinetics for the surface activity in shallow streams.     

Perspectives on the landmark decision designating the northern spotted owl (Strix occidentalis caurina) as a threatened subspecies

Following an extensive legal battle challenging its original decision to not extend the protection of the Endangered Species Act to the northern spotted owl (Strix occidentalis caurina), the US Fish and Wildlife Service was ordered by the 9th District Court of Appeals to reassess the status of the owl. As a result of the revised analysis, the service proposed the northern spotted owl for threatened status throughout its range. Because of the complex biological issues involved and the perceived potential for economic disruption in timber-dependent communities of the Pacific Northwest, this proposal generated more controversy and interest than any previous one. In this article I discuss the rationale for the service’s decision, public involvement in the process, and the mechanisms now available to conserve the northern spotted owl and its habitat under the Endangered Species Act.     

Advanced technology industry in Oxfordshire

The growth of advanced technology industry in Oxfordshire has mainly been generated from within the county. The increasing number of firms has attracted the interest of numerous property developers wishing to build science parks and business parks in and around Oxford. This is where growth has been highest, but where there are policies of restraint and to protect the green belt.     

WATER SUPPLY AND URBAN GROWTH PLANNING: A PARTNERSHIP1

ABSTRACT As urban expansion outstrips water supplies, the usual solution is to build pipelines to bring in water from sources farther afield. Such water supplies may act as either a leader of urban development or as a follower. In either case, this engineering approach to the provision of water has fostered less than optimal utilization of regional water and land resources for urban growth. More efficient utilization of these resources is achieved when water supply development and urban growth planning are conjoint activities. Water supply planners and land use planners, working together, are able to generate and evaluate the full range of urban development options, including water demand management through conservation. Preferred regional growth plans are achieved using the best mix of water supply and urban growth. The result is a reduced rate of water supply development and a reduction of urban expansion on prime lands. This partnership approach is demonstrated for the Calgary Region under two levels of water conservation.     

Effects of Nitrogen Supply on the Sensitivity to O3 of Growth and Photosynthesis of Japanese Beech (Fagus crenata) Seedlings

To obtain basic information for evaluating critical levels of O₃ under different nitrogen loads for protecting Japanese beech forests, two-year-old seedlings of Fagus crenata Blume were grown in potted andisol supplied with N as NH₄NO₃ solution at 0, 20 or 50 kg ha⁻¹ year⁻¹ and exposed to charcoal-filtered air or O₃ at 1.0, 1.5 and 2.0 times the ambient concentration from 16 April to 22 September 2004. The O₃ induced significant reductions in the whole-plant dry mass, net photosynthetic rate at 380 μmol mol⁻¹ CO₂ (A ₃₈₀), carboxylation efficiency (CE) and concentrations of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and total soluble protein (TSP) in the leaves. The concentrations of Rubisco and TSP were negatively correlated with the concentration of leaf acidic amino acid, suggesting that O₃ enhanced the degradation of protein such as Rubisco. The N supply to the soil did not significantly change the whole-plant dry mass and A ₃₈₀, whereas it significantly increased the CE and concentrations of Rubisco and total amino acid. No significant interactive effects of O₃ and N supply to the soil were detected on the growth, photosynthetic parameters and concentrations of protein and amino acid in the leaves. In conclusion, N supply to the soil at ≤50 kg ha⁻¹ year⁻¹ does not significantly change the sensitivity to O₃ of growth and net photosynthesis of Fagus crenata seedlings.     

连栽对杨树人工林林木生长的影响

通过野外调查和室内试验，研究苏北杨树产区相似立地条件下，不同种植代次的杨树人工林树高、胸径、材积和其叶片N、P、K3种营养元素含量的变化特征。结果表明，4年生林树高、胸径和材积从第三代开始出现明显下降，第二代4年生林生长较快，第三代林生长势与第一代大致相同。随栽植代数增加，7年生、10年生林树高、胸径、材积生长呈下降趋势，7年生林的树高、胸径、材积生长量受连栽的影响存在显著差异。不同年生林叶片营养元素受代次增加的影响未显示一定的规律性。     

Influence of static magnetic fields on nerve regeneration in vitro

Our research involves determining how non-invasive electric and magnetic fields influence neuronal growth in vitro. In previous studies we have shown that pulsed electromagnetic fields (PEMF) as well as direct current (DC) alone stimulate neurite outgrowth from dorsal root ganglion explants [Sisken et al. 1984; Sisken et al. (Restor Neurol Neurosci 1:303–309, 1990); Greenebaum et al. (Bioelectromagnetics 17:293–302, 1996)]. A maximum response was obtained when nerve growth factor (NGF) was also present in the medium. The results of our experiments using static magnetic fields of different strengths are presented below and indicate that fields of high magnetic strength (450–900 gauss) with added NGF stimulate neurite outgrowth comparable to the response obtained with PEMF plus NGF.     

Comparing the Growth Characteristics of Three Bacteria Involved in Degrading Rubbers

Three bacteria isolated for degradation of rubbers were compared for their growth characteristics derived from the Bradford protein assay and turbidity (optical density, OD) measurement. Both Alcaligenes xylosoxidans T2 and Pseudomonas aeruginosa GP10 were fast-growing bacteria while Nocardia corynebacterioides S3 was a slow grower utilizing rubber as the sole source of carbon and energy, but the extent of degradation was lower by the formers than the latter. A. xylosoxidans T2, P. aeruginosa GP10 and N. corynebacterioides S3 showed a typical sigmoidal growth pattern based on binding of Coomassie Brilliant Blue G250 to bacterial proteins and spectrophotometrical measurement at 600 nm. Both assays showed similar growth characteristics for all three bacteria in this study. Degradation of rubber was more pronounced by N. corynebacterioides S3 than either A. xylosoxidans T2 or P. aeruginosa GP10 during 70 days of incubation. Our results suggest that slow-growing bacteria may play a much greater role in degrading polymeric materials than was previously believed.