3,256 research outputs found
Population Differences in Death Rates in HIV-Positive Patients with Tuberculosis.
SETTING: Randomised controlled clinical trial of Mycobacterium vaccae vaccination as an adjunct to anti-tuberculosis treatment in human immunodeficiency virus (HIV) positive patients with smear-positive tuberculosis (TB) in Lusaka, Zambia, and Karonga, Malawi. OBJECTIVE: To explain the difference in mortality between the two trial sites and to identify risk factors for death among HIV-positive patients with TB. DESIGN: Information on demographic, clinical, laboratory and radiographic characteristics was collected. Patients in Lusaka (667) and in Karonga (84) were followed up for an average of 1.56 years. Cox proportional hazard analyses were used to assess differences in survival between the two sites and to determine risk factors associated with mortality during and after anti-tuberculosis treatment. RESULTS: The case fatality rate was 14.7% in Lusaka and 21.4% in Karonga. The hazard ratio for death comparing Karonga to Lusaka was 1.47 (95% confidence interval [CI] 0.9-2.4) during treatment and 1.76 (95%CI 1.0-3.0) after treatment. This difference could be almost entirely explained by age and more advanced HIV disease among patients in Karonga. CONCLUSION: It is important to understand the reasons for population differences in mortality among patients with TB and HIV and to maximise efforts to reduce mortality
Multi-Stem Mechanized Harvesting Operation Analysis – Application of Arena 9 Discrete-event Simulation Software in Zululand, South Africa
Time studies were carried out on a stump-to-mill multi-stem Eucalyptus harvesting and transport operation in Zululand, South Africa in 2007. A simulation model (System 1) of this system was subsequently built using a commercial simulation software package (Arena 9) and data from the time studies incorporated into the model. Following this, two hypothetical stump-to-mill multi-stem models (Systems 2 and 3) were built using Arena 9 and parameterized input data. All models were found to adequately represent reality. Simulated harvesting system balance was improved through normalization of machine utilization in Systems 2 and 3. Production improvements were predicted with simulated timber production per month increasing by 31.1% and 30.8%, from System 1 with three trucks, to System 2 with four trucks, and System 3 with four trucks, respectively. Cost reduction was predicted, with the cost per unit of timber decreasing by 12.5% and 4.1%, from System 1 with three trucks, to System 2 with four trucks and System 3 with four trucks, respectively. Beneficial operational techniques were also confirmed using the simulation models. In the studied conditions delimbing and debarking of full trees into tree lengths at roadside with delimber-debarkers before cross-cutting and loading with a slasher was predicted to be $0.65/m3 cheaper than delimbing, de-barking, and cross-cutting full trees into pulpwood with processors at the landing and then loading with a loader. Usability of Arena 9 in modeling forest harvesting operations was concluded as acceptable, but required detailed background logic inclusion
Generalized Geologic Map for Land-Use Planning: Trigg County, Kentucky
This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock
Generalized Geologic Map for Land-Use Planning: McCracken County, Kentucky
This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock
Generalized Geologic Map for Land-Use Planning: Marshall County, Kentucky
This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock
Generalized Geologic Map for Land-Use Planning: Caldwell County, Kentucky
This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock
Generalized Geologic Map for Land-Use Planning: Henderson County, Kentucky
This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock
Quality of Water from Tile Drains in Fields Treated with Poultry Litter in McLean County, Kentucky
Poultry litter (a mixture of feed, manure, and bedding material) is commonly used as a soil amendment to row-crop fields in western Kentucky. Because of feed additives, litter typically has elevated concentrations of contaminants, including metals and anions. These metals and anions can accumulate in the soil and therefore could be transported to surface water through drainage tiles. In order to assess water quality in tile drains, a pilot study was conducted in 2008 in McLean County, Kentucky, in which 10 tile drains and six drainage ditches were sampled for total metals and anions. Seven of the tile-drained fields were amended with poultry litter and three tile-drained fields were not amended. Drainage ditches received discharge from the tile drains. Acidified and unacidified samples were collected for laboratory analysis, and the acidified samples were analyzed for total major and trace metals (aluminum, arsenic, calcium, cadmium, copper, iron, mercury, magnesium, manganese, nickel, lead, and zinc). To determine the association of major and trace metals to suspended material in the water, the unacidified samples were filtered using 0.45- and 0.20-µm filters, and each filtered sample was analyzed for major and trace metals.
Mean concentrations for total calcium and magnesium were similar for the amended and unamended field samples. Total aluminum, iron, and manganese concentrations were higher in the amended-field samples than in the unamended-field samples. Total arsenic, cadmium, and mercury concentrations were below the method detection limits for all samples. Total copper and nickel concentrations were higher in the amended-field samples than in the unamended-field samples.
Calcium, magnesium, and manganese concentrations did not decrease after samples were filtered. Aluminum and iron concentrations decreased, indicating that these metals are associated with suspended sediment in the tile discharge water. Copper and nickel concentrations did not decrease after the samples were filtered.
Chloride, sulfate, and nitrate concentrations were higher in amended-field samples than in unamended-field samples. The mean nitrate concentration for the tile-drain samples from amended fields was above the U.S. Environmental Protection Agency maximum contaminant level of 10 ppm. All phosphate concentrations were below the MDL.
Additional sampling is needed to more thoroughly document concentrations and evaluate the impact of potential contaminants associated with poultry litter on the quality of tile-drain water in Kentucky
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