A VEGETATION RECONSTRUCTION OF UNION COUNTY, PENNSYLVANIA DURING THE EARLY HISTORICAL PERIOD (1755-1855)

This thesis assesses relationships between vegetation and topography and the impact of human tree-cutting on the vegetation of Union County during the early historical era (1755-1855). I use early warrant maps and forestry maps from the Pennsylvania historical archives and a warrantee map from the Union County courthouse depicting the distribution of witness trees and non-tree surveyed markers (posts and stones) in early European settlement land surveys to reconstruct the vegetation and compare vegetation by broad scale (mountains and valleys) and local scale (topographic classes with mountains and valleys) topography. I calculated marker density based on 2 km x 2 km grid cells to assess tree-cutting impacts. Valleys were mostly forests dominated by white oak (Quercus alba) with abundant hickory (Carya spp.), pine (Pinus spp.), and black oak (Quercus velutina), while pine dominated what were mostly pine-oak forests in the mountains. Within the valleys, pine was strongly associated with hilltops, eastern hemlock (Tsuga canadensis) was abundant on north slopes, hickory was associated with south slopes, and riparian zones had high frequencies of ash (Fraxinus spp.) and hickory. In the mountains, white oak was infrequent on south slopes, chestnut (Castanea dentata) was more abundant on south slopes and ridgetops than north slopes and mountain coves, and white oak and maple (Acer spp.) were common in riparian zones. Marker density analysis suggests that trees were still common over most of the landscape by 1855. The findings suggest there were large differences in vegetation between valleys and mountains due in part to differences in elevation, and vegetation differed more by topographic classes in the valleys than in the mountains. Possible areas of tree-cutting were evenly distributed by topographic classes, suggesting Europeans settlers were clearing land and harvesting timber in most areas of Union County.

[Influence of chronic, structural changes of the muscle-tendon unit on the indication and technique of rotator cuff reconstruction]

Rotator cuff lesions are common and the incidence increases with age. After tendon rupture of the rotator cuff, the muscle-tendon unit retracts, which is accompanied by muscle fatty infiltration, atrophy, and interstitial fibrosis of the musculature, thus, fundamentally changing the muscle architecture. These changes are important prognostic factors for the operative rotator cuff reconstruction outcome. Selection of the correct time point for reconstruction as well as the optimal mechanical fixation technique are decisive for successful attachment at the tendon-to-bone insertion site. Thus, knowledge of the pathophysiological processes plays an important role. The goal of this article is to establish a relationship between currently existing evidence with respect to the preoperatively existing changes of the muscle-tendon unit and the choice of the time for the operation and the operative technique.

Reconstruction of large supra-eyebrow and forehead defects using the hatchet flap principle and sparing sensory nerve branches

To reconstruct a forehead defect, a plastic surgeon must be knowledgeable about the neural, vascular, and muscular anatomy. The position of fixed structures such as eyebrows and hairline should be respected. For the past 5 years, we have used double hatchet flaps for reconstruction of relatively large supra-eyebrow and forehead defects. Because this flap does not appear to be among the techniques used by young plastic surgeons, we thought that it would be valuable to report our experience.