Airborne light detection and ranging (LIDAR) measurements derived before and after Hurricanes Katrina and Wilma (2005) were used to quantify the impact of hurricanes and lightning strikes on the mangrove forest at two sites in Everglades National Park (ENP). Analysis of LIDAR measurements covering 61 and 68 ha areas of mangrove forest at the Shark River and Broad River sites showed that the proportion of high tree canopy detected by the LIDAR after the 2005 hurricane season decreased significantly due to defoliation and breakage of branches and trunks, while the proportion of low canopy and the ground increased drastically. Tall mangrove forests distant from tidal creeks suffered more damage than lower mangrove forests adjacent to the tidal creeks. The hurricanes created numerous canopy gaps, and the number of gaps per square kilometer increased from about 400~500 to 4000 after Katrina and Wilma. The total area of gaps in the forestincreased from about 1~2% of the total forest area to 12%. The relative contribution of hurricanes to mangrove forest disturbance in ENP is at least 2 times more than that from lightning strikes. However, hurricanes and lightning strikes disturb the mangrove forest in a related way. Most seedlings in lightning gaps survived the hurricane impact due to the protection of trees surrounding the gaps, and therefore provide an important resource for forest recovery after the hurricane. This research demonstrated that LIDAR is an effective remote sensing tool to quantify the effects of disturbances such as hurricanes and lightning strikes in the mangrove forest.

In copper-deficient rats, oral intubation of copper increases the rate of ceruloplasmin synthesis without affecting general synthesis of plasma or liver proteins. It also restores the enzyme from half to full activity. Copper given by injection at doses commonly employed has additional nonspecific effects on protein synthesis and in some strains of rats produces severe hemolysis. In contrast to deficient rats, in normal rats copper does not elevate plasma ceruloplasmin unless hemolysis also occurs. Thus, at least in deficiency, copper availability controls the rate of synthesis, activation, and plasma concentration of cemloolasmin.

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Articular cartilage collagenase activity was determined for 28 sections obtained from twelve femoral heads. For each one square centimeter area, a section was graded by a histologic-histochemical grading system for the severity of the arthritis. Collagenase activity was found primarily in those areas of moderately severe disease, but not in mild or end stage arthritis.In examining joints with advanced or "end stage" osteoarthritis, one frequently encounters sites in which the articular cartilages have been totally lost with resultant exposure and eburnation of the underlying bony endplate. The mechanism by which this extensive degradation occurs is not completely understood, but there is ample evidence to indicate that at least a portion of the loss results from autolytic enzymatic digestion. Cathepsin D which acts optimally at a pH of 4.5 and neutral cartilage proteoglycanases which degrade the proteoglycan of the matrix have been described in several laboratories (1,2) and data have been presented Submitted for publication November 28, 1977; accepted in revised form June 7, 1978. which suggest that lysosomal activity varies directly with the severity of the osteoarthritis (3). The substrate of the catheptic lysosomal enzymes appears to be principally proteoglycan, but it would seem logical that a mechanism for destruction of the collagen also exists since total loss of substance does occur. Recently the presence of an articular cartilage collagenase which could not be detected in normal tissue was described in osteoarthritic cartilage (4).This observation is interesting in that it supports the possibility that end stage osteoarthritis may result from the action of cathepsin-neutral proteoglycanase (to destroy the proteoglycan) and collagenase activity to degrade the collagen. In order to confirm this hypothesis, it seems essential that a variation of collagenase concentration with severity of the diseases existed, particularly since prior studies from this laboratory had shown direct correlation of DNA, glycosaminoglycan ($6) and collagen synthesis (7) and concentration of hydrolytic enzymes (3) with advancing degrees of severity, particularly with mild and moderately severe osteoarthritis. To assess this, studies were performed on osteoarthritic femoral heads in which cartilage collagenase was compared with the severity of the disease process, as measured by a histologic-histochemical grading system (6) ( Table 1). MATERIALS AND METHODSTwelve human femoral heads, removed from patients at the time of replacement surgery, were obtained in the fresh state from the operating room. Eleven of the patients had the clinical diagnosis of osteoarthritis which was confirmed by