Nagwan Mahmoud Mahmoud Afify: Effect of Land Degradation on Land Cover Attributes of East Suez Canal Using Remote Sensing Techniques, Unpublished Ph.D. thesis, Arid Land Agricultural Graduate Studies and Research Institute, Faculty of Agriculture, Ain Shams University, 2017. The use of remote sensing techniques has become increasingly important in describing a variety of satellite derived data sets and their application to understand changes in the landscape. The aim of this investigation is to employ remote sensing data, GIS and extensive field observations to monitor land cover in the study area and to assess the land degradation status. Also, to predict the deterioration magnitude in the study area under the existed informal agriculture management practices. The selected area for this study represented by about 163527 hectares located in Ismailia Governorate east of Suez Canal, Egypt. In this work, both Hyperion and Landsat 8 data were employed to achieve the study objectives. The study area was classified into four physiographic units including; Alluvial terraces of flat surfaces, Aeolian plain of shifting sands, Sabkhas and Submerged areas. Soil drainage conditions are classified into three categories that described as excessively drained soils located in the Aeolian plain, well drained soils occurred in alluvial terraces and very poorly drained soils that were developed within the waterlogged areas or under the submerged ones. Pearson’s correlation coefficients indicated that NDVI for Hyperion data is highly correlated to NDWI, NDMI and NDSI as the correlation coefficient magnitudes are 0.95, 0.75 and 0.82 respectively. They are all above the value of 0.7 (highly correlated variables). Accordingly, NDVI index can be considered as a master index that can be used for well identification of the multiple land cover features and their distributions.

Abstract

Prone positioning is a common position used for access to the posterior head, neck, and spine during spinal surgery, access to the retroperitoneum and upper urinary tracts and access to posterior structures when required during plastic surgery. There are different variants of prone position with variable advantages and disadvantages for each one. Many physiological changes occur when turning the patient into prone position including respiratory, cardiovascular and cerebrovascular changes. One of the cardiovascular changes is the decrease in cardiac output seen on turning the patient prone which is considered to be a result of reduced stroke volume. A decrease in pre-load is thought to be responsible for the reduced stroke volume that is seen. The resulting decrease in arterial pressure is, to some extent, countered by a compensatory sympathetic tachycardia and an increase in peripheral vascular resistance.