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71.
Larry Larsen Terri Morrell Gretchen Schalge Meghan Gallione Joseph Bell Kip Petersen Frederick Steiner 《Environmental management》1991,15(4):549-563
This article is the third in a series prepared to explain the Teller County growth management planning process. Once it was
determined by local decision-makers that Teller County, Colorado, would pursue a policy of directed growth, concepts based
on this policy were developed. These concepts presented visions and options for the future. Landscape plans then were developed
for Teller County and the City of Woodland Park planning area so that these options could be visualized by local leaders and
the public. The landscape plans were used as part of the ongoing citizen involvement process to inform the public about the
options for growth management. To provide even more information, detailed designs were developed for specific areas in the
county. From the landscape plan, public involvement effort, and detailed designs, specific implementation measures were identified,
discussed, and adopted. These measures included guidelines for administration, so that county and city goals could be linked
to the actual day-to-day management of development proposals.
Paper 3 in a series of 3. 相似文献
72.
The establishment and interrelationships of microorganisms with soil and plant processes during reclamation are greatly influenced by the composition of the planting medium and vegetation practices. While in some instances the parent material may be used as the vegetation medium, the practice of topsoiling, particularly the direct haul method, may be beneficial in introducing microorganisms and improving the quality of the plant growth medium of spoils that are chemically or physically less desirable than the native soils. The influence of different vegetation types on soil development on surface mines may be a reflection of physioiogical differences that affect microbial development in the rhizosphere. Such differences include levels of carbohydrate translocated to the root system and/or released into the surrounding soil; the plant's effectiveness as a mycorrhizal host; and the rate of degradation of plant residues. It has become apparent that microbial interactions are an important part of plant and soil processes in reclamation. While some of the microorganisms important in plant growth and soil development can be introduced readily by management practices, the majority usually are disseminated by natural means and only gradually become a part of the microbial population. More research is needed on developing new methods or refining current procedures for early introduction of these microorganisms in reclamation practices. 相似文献
73.
74.
Herman E. Wyandt Ph.D. Thomas Maker Nancy L. Fisher Shivanand R. Patil Peter Osella Frederick W. Luthardt Charles Kawada Roger Williamson Aubrey Milunsky 《黑龙江环境通报》1990,10(9):569-574
We report three cases of amniocentesis in which mosaicism for trisomy 12 was detected in two or more independent cultures. The parents elected to terminate the pregnancy in all three cases. Follow-up studies in two of the cases confirmed the mosaicism in fetal tissues (in subcutaneous tissue in one case; in fetal lung in the other), but not in blood. No fetal anomalies were evident by ultrasound or at autopsy. These results along with other reported cases demonstrate the difficulty in counselling for mosaic trisomy 12. 相似文献
75.
Two experiments were conducted in male SD rats (225-250 g) to determine changes in the activities of endogenous antioxidants superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and concentrations of glutathione (GSH) in tissues after exposure to low doses of endosulfan and chlorpyrifos using a whole body exposure technique. In both experiments, 6 rats/group were exposed 3 hr/day, 5 days/week for 30 days to: 0 (control), 5, 10, 20, 40 and 60% of LD50 of either pesticide in 50% ethanol; actual concentrations were: endosulfan = 0, 0.5, 1.0, 2.0, 4.0, 6.0 mg/250 g body weight; chlorpyrifos = 0, 1.9, 3.8, 7.6, 15.2, and 22.8 mg/250 g body weight. Endosulfan decreased erythrocyte SOD by 21% in all groups and chlorpyrifos increased SOD by 18% in groups 40 and 60. Liver SOD was 12%-20% lower after endosulfan exposure; lung SOD was altered: endosulfan decreased activity by 21% and 51% and chlorpyrifos by 58 and 75% in the 40 and 60 groups, respectively (P < or = 0.05). Both pesticides increased plasma GPX activity at lower levels and reduced it by 26% and 19% in groups 40 and 60, respectively (P < or = 0.05). Liver GPX increased in the 60 group and lung GPX declined between 20% and 38% after endosulfan exposure. GSH in the liver and lung: endosulfan reduced GSH by about 30% at lower levels and increased by 41% or 70% at higher levels; chlorpyrifos decreased GSH by 28-40% in 20 and 60 groups, respectively (P < or = 0.05). Exposure to low, increasing levels of endosulfan and chlorpyrifos can differentially modify endogenous antioxidants SOD, GPX and GSH, which may lead to the development of oxidative stress in some tissues. 相似文献
76.
John S. Stanley Kathy E. Boggess Jon Onstot Thomas M. Sack Janet C. Remmers Joseph Breen Frederick W. Kutz Joseph Carra Philip Robinson Gregory A. Mack 《Chemosphere》1986,15(9-12):1605-1612
Analysis for tetra- through octachloro-PCDDs and PCDFs was completed for 46 tissue samples prepared from the U.S. Environmental Protection Agency (EPA) National Human Adipose Tissue Survey (NHATS). The samples were prepared as composites from over 900 specimens to represent the nine U.S. census divisions and three age groups (0–14, 15–44, and 45 plus years). The data demonstrate that PCDDs and PCDFs are prevalent in the general U.S. population and that differences exist with age. 相似文献
77.
Matrix diffusion in saturated rocks with very low permeability is one of the major mechanisms of solute transport. Laboratory out-diffusion experiments on rock samples may provide an estimate of the bulk diffusion coefficient. However, numerous results have shown that this average parameter does not really depict the complex mechanism of diffusion as a function of the internal heterogeneity of crystalline rocks. Two-dimensional images of the porosity distribution in a granite sample were obtained by impregnation with a radioactive resin and autoradiography. Some examples based on these images and synthetic images were used to perform numerical simulations of out-diffusion using two different random walk methods. The simulated shapes of the out-diffusion curves depend on the spatial distribution of the porosity and on the pore connectivity with the border of the sample. Such relations might explain the multiple nested slopes or the convex shapes often observed on real experimental curves. 相似文献
78.
79.
The mid-Atlantic region of the United States has a wide diversity of natural resources. Human pressures on these natural resources are intense. These factors have resulted in the collection of substantial amounts of environmental information about the region by EPA (both Regional and Research Offices), other governmental agencies, industry, and environmental groups. EPA Regional Offices comprehend first hand the importance of environmental data and are extremely supportive of investments in these data. Environmental data are used prominently in a variety of strategic planning and resource management initiatives. In EPA Region 3, the use of scientifically-sound environmental data is, in fact, one of our strategic programmatic goals. Environmental information is captured and assessed continuously by Regional staff, sometimes working in partnership with other Federal and State agencies, to derive relevant resource management conclusions. The restoration goals for the Chesapeake Bay are based on environmental indicators and resulting data. Attainment of the water quality objectives for streams and coastal estuaries are predicted on monitoring data. Our initiative in the Mid-Atlantic Highlands area uses environmental indicators to measure the condition of forests and streams. Landscape-level indicators will provide unique opportunities for the use of data in planning and management activities in support of the principles of community-based activism and sustainable development. Significant value is added to these data during their use by Regional managers. Regional programs, such as the Chesapeake Bay Program and several National Estuary Programs, are founded in environmental data. Environmental information is used by the Regional program managers to ascertain whether programs are accomplishing their intended objectives. Finally, Regional programs provide a crucial means for disseminating this information to broad segments of the public, so that a better informed and educated client base for effective environmental protection will develop. 相似文献
80.
Melvin W. First Frederick J. Viles Jr. 《Journal of the Air & Waste Management Association (1995)》2013,63(3):122-127
Multistage gas absorption of 1–50% nitric oxide, nitrogen dioxide, and nitrogen tetraoxide from air with water or caustic solutions can produce colorless stack discharges. The rate at which NO is oxidized to No2 in the gas phase and the solubility rate of No2 in water or solution are highly concentration dependent so that reductions of stack gas concentrations of nitrogen oxides below approximately 200 ppm appear to be impractical. High efficiency absorption combined with elevated discharge of the cleaned, colorless gases is an acceptable method of air pollution control for many troublesome operations. Experiences in the fields of rocketry and nuclear energy are cited. Engineering modifications of metal pickling operations have been found especially helpful in producing effective control at an acceptable cost. 相似文献