Rangeland degradation is one of the global concerns affecting the pastoralists and those who suffer from its negative environmental consequences. Grazing exclosure has been extensively used among the techniques implemented by the government to protect the fertility of threatened rangelands. The impact of exclosure has been a controversial issue; therefore, it is important to understand its effe...

A global multicompartment model which is based on a 3-D atmospheric general circulation model (ECHAM5) coupled to 2-D soil, vegetation and sea surface mixed layer reservoirs, is used to simulate the atmospheric transports and total environmental fate of dichlorodiphenyltrichloroethane (DDT) and γ -hexachlorocyclohexane (γ -HCH, lindane). Emissions into the model world reflect the substance’s ag...

x Abstract Jets can be probed in their innermost regions (d ∼ 0.1 pc) through the study of the relativistically boosted emission of blazars. On the other extreme of spatial scales, the study of structure and dynamics of extragalactic relativistic jets received renewed impulse after the discovery, made by Chandra, of bright X-ray emission from regions at distances larger than hundreds of kpc fro...