Vicente Medina challenges common misconceptions and excuses for extreme political violence. Countering such axioms as “one man’s freedom fighter is another man’s terrorist” and the “do whatever it takes” attitude toward counter-terrorism, Medina differentiates between justified political violence and unjustifiable terrorism. Surveying terrorism with both historical and contemporary examples, Medina dispels the relativism and emotional responses that have been used by some to justify terrorist acts. Medina draws on philosophical concepts like just war theory while adding social and political science perspectives to contextualize today’s terrorism within current international law and moral attitudes.
Diabetic retinopathy (DR) is the leading cause of acquired blindness in working age adults worldwide. Biochemical changes in DR contribute to both the microscopic structural and functional changes in the retina. All these alterations result in macroscopic retinal damage that can be assessed by funduscopy. The overproduction of reactive oxygen species (ROS) in the mitochondria is considered a causal link between elevated glucose and biochemical abnormalities in the pathophysiology of DR. Moreover, oxidatively induced pathways also seem to provide positive feedback to ROS production, resulting in a vicious cycle. ROS can directly damage lipids, proteins and DNA, leading to cell death. To make the situation worse, antioxidant defenses are also impaired in diabetes. Otherwise, ROS are involved in the production of inflammatory cytokines and growth factors such as interleukins or vascular endothelial growth factor (VEGF). In addition, ROS not only contribute to the development of DR, but also play a role in its progression when the hyperglycemic insult is controlled. This phenomenon is called metabolic memory.
Conventional treatments for diabetic retinopathy (DR) includes glycemic control, laser photocoagulation, vitrectomy, intravitreal triamcinolone, and intravitreal anti-vascular endothelial growth factor agents. However these strategies have not proved capable of halting the progression of this disease in all cases. The mechanisms leading to DR are not fully understood, but there is a growing body of evidence showing that oxidative stress plays a pivotal role in the development of this diabetic complication. In fact it has been proposed that oxidative stress is the initial and maintaining event that triggers and provides feedback to the other pathophysiological pathways related to DR. The experimental data discussed in this review show that different antioxidant agents may prevent various biochemical and structural alterations in retinal cells cultured under hyperglycemic conditions, and also in experimental diabetic animals. Although the results of human trials are somewhat variable, some clinical studies have provided promising results.
We are increasingly faced with environmental problems and required to make important decisions. In many cases an understanding of one or more geologic processes is essential to finding the appropriate solution. Earth and Environmental Sciences are by their very nature a dynamic field in which new issues continue to arise and old ones often evolve. The principal aim of this book is to present the reader with a broad overview of Earth and Environmental Sciences. Hopefully, this recent research will provide the reader with a useful foundation for discussing and evaluating specific environmental issues, as well as for developing ideas for problem solving. The book has been divided into nine sections; Geology, Geochemistry, Seismology, Hydrology, Hydrogeology, Mineralogy, Soil, Remote Sensing and Environmental Sciences.
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