PubMed · 15376375
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
P Calow. 2004. General introduction.. https://doi.org/10.1023/b%3Aemas.0000033039.36520.2d
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
The service life of lubricating oil produced in the United Arab Emirates (UAE) was examined using a car fueled with leaded or unleaded gasoline of the same grade in harsh local conditions. In addition, the economic impact of using leaded vs. unleaded gasoline via the effects on the useful life of engine oil was investigated. Every 500 km that the car was operated, the physical properties of the oil were examined to determine the optimum oil life before replacement. It was found that relative to unleaded gasoline, leaded gasoline resulted in a faster deterioration of lube oil properties and a reduced useful life of the oil. Many of the effects of use on the physical properties of oil became apparent from the beginning of its service, especially when leaded gasoline was used. Our findings indicate that the recommended useful life of oil when using leaded gasoline is 2500 km. With unleaded gasoline, deterioration of the physical properties of the lubricating oil became a concern after 3000 km. Thus with unleaded gasoline, it is recommended to have an oil change every 3500 km. These findings indicate that the decision of the UAE government to stop using lead compound additives to improve the octane number of gasoline will not only protect the environment from the harmful effects of lead compounds, but will also extend the useful life of oil. This extension will reduce the amount of used oil that is disposed of by up to 4678 tons/year. This reduction in oil use translates to a cost savings of about 23.4 million UAE Dirhams (=$6.37 million US Dollars) per year.
The establishment phase is an important bottleneck in the life cycle of plants. It consists of two steps that are rarely separated, i.e., the germination of seeds and the establishment of seedlings. Here we report the results of two experiments in which we independently investigated germination and seedling establishment in the greenhouse, under different grass vegetation treatments representing different regeneration niches. Seeds of Tragopogon pratensis from six populations and two habitat types were studied, three from roadside verges and three from hayfields. Germination percentages and germination speed were higher for seeds from roadside verges than for seeds from hayfields, but were little affected by treatment. In contrast, seedling growth was much lower in the tall grass vegetation, than in the short grass and especially the bare soil treatment. Seedling sizes were generally similar for different populations and habitat types. Our results thus show that the two early steps in the establishment phase of plants may respond very differently to the micro-environment, and may have a different selection history. Insight into the ecology and evolution of life histories may require that germination and establishment are considered separately.
The U.S. Environmental Protection Agency (EPA) defines environmental justice as the "fair treatment for people of all races, cultures, and incomes, regarding the development of environmental laws, regulations, and policies." The last decade has focused considerable national attention on the environmental pollution inequity that persists among the nation's poorest communities. Despite these environmental justice efforts, poor communities continue to face adverse environmental conditions. For the more than 550 Native American communities, the struggle to attain environmental justice is more than a matter of enforcing national laws equitably; it is also a matter of a federal trust duty for the protection of Indian lands and natural resources, honoring a promise that Native American homelands would forever be sustainable. Equally important is the federal promise to assist tribes in managing their reservation environments under their reserved powers of self-government, an attribute that most distinguishes tribes from other communities. The PM Northwest, Inc. (PMNW) dumpsite is located within the boundaries of the Swinomish Indian Reservation in Washington State. Between approximately 1958 and 1970, PMNW contracted with local oil refineries to dispose of hazardous wastes from their operations at the reservation dumpsite. Almost two decades would pass before the Swinomish tribe was able to persuade EPA that a cleanup action under Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) was warranted. This article reviews the enduring struggle to achieve Indian environmental justice in the Swinomish homeland, a process that was dependent upon the development of the tribe's political and environmental management capacity as well as EPA's eventual acknowledgement that Indian environmental justice is integrally linked to its federal trust responsibility.