Mapping threats to power line corridors for Connecticut rights-of-way management.

Trees are a major threat to power line security across forested regions of the world. We developed a decision support system for identifying locations in Connecticut, USA where trees have grown tall enough to make contact with transmission lines during storms. We used the Random Forest algorithm, danger tree presence/absence data, and 25 raster environmental datasets to develop (1) an understanding of the abiotic environmental settings that host danger trees and (2) a spatially explicit map of danger tree distributions across Connecticut power line corridors. Danger trees were prevalent in locations (1) with an infrequent history of storms; (2) forested and residential land uses; and (3) low to middle elevations. Products from this research can be transferred to adaptive right-of-way management because they present managers with key information on where danger trees are likely to occur, and the methods presented herein have great potential for future application to other regions managers seek to identify high priority areas for danger tree removal.

Decision support for mitigating the risk of tree induced transmission line failure in utility rights-of-way.

Vegetation management is a critical component of rights-of-way (ROW) maintenance for preventing electrical outages and safety hazards resulting from tree contact with conductors during storms. Northeast Utility's (NU) transmission lines are a critical element of the nation's power grid; NU is therefore under scrutiny from federal agencies charged with protecting the electrical transmission infrastructure of the United States. We developed a decision support system to focus right-of-way maintenance and minimize the potential for a tree fall episode that disables transmission capacity across the state of Connecticut. We used field data on tree characteristics to develop a system for identifying hazard trees (HTs) in the field using limited equipment to manage Connecticut power line ROW. Results from this study indicated that the tree height-to-diameter ratio, total tree height, and live crown ratio were the key characteristics that differentiated potential risk trees (danger trees) from trees with a high probability of tree fall (HTs). Products from this research can be transferred to adaptive right-of-way management, and the methods we used have great potential for future application to other regions of the United States and elsewhere where tree failure can disrupt electrical power.

Inability of indomethacin to modify hydrochlorothiazide diuresis and natriuresis by the chimpanzee kidney.

A drug interaction study in the chimpanzee by using indomethacin and hydrochlorothiazide has shown conclusively that the diuretic and saluretic properties of hydrochlorothiazide were not compromised by indomethacin. This was true whether hydrochlorothiazide or indomethacin was administered first. The renal clearance of hydrochlorothiazide was not influenced by indomethacin nor was the renal clearance of indomethacin significantly altered by hydrochlorothiazide. Indomethacin alone caused a small but significant increase in sodium, potassium and chloride excretion and in Curate/glomerular filtration rate. In control experiments with placebo, potassium excretion was also significantly increased. The implications of these observations remain obscure. In all experiments utilizing hydrochlorothiazide, the well known renal effects of this agent were clearly evident under these experimental conditions.