Although many sediment budgets estimate the effects of logging, few have considered the potential impact of timber harvesting on stream density. Failure to consider changes in stream density could lead to large errors in the sediment budget, particularly between the allocation of natural and anthropogenic sources of sediment. This study conducted field surveys in randomly selected catchments in...

to identify critical sediment sources in large catchments, using easily available terrain information at a regionalscale, a methodology was developed to obtain a qualitative assessment necessary for environmental management.fargas et al method was employed in the research. the study was carried out in one of the sub-basins of hableh roodbasin called dehnamak in the arid and semiarid climate of ...

introduction the iran has vast areas of karst landforms due to the relatively high carbonaceous rocks deposited during different geologic eras. karst landforms are noteworthy for investigation from many aspects. the primary importance of these regions is the considerable amount of underground water stored in karst formations. these reserves are favorable, both in quality and quantity, as natura...

Mouse 3T3 cells and their Simian Virus 40-transformed derivatives (3T3SV) were used to assess the relationship of transformation, cell density, and growth control to the cellular distribution of newly synthesized glycosaminoglycan (GAG). Glucosamineand galactosamine-containing G A G were labeled equivalently by [all]glucose regardless of culture type, allowing incorporation into the various G A...

Across Africa, perennial drainage density as a function of mean annual rainfall defines three regimes separated by threshold values of precipitation. This nonlinear response of drainage to rainfall will most seriously affect regions in the intermediate, unstable regime. A 10% decrease in precipitation in regions on the upper regime boundary (1000 millimeters per year) would reduce drainage by 1...

Watershed is regarded as a very complex system of natural, social, economic and ecological dimensions and like any similar systems, exploitation of its resources requires a comprehensive and coordinated planning and management. Given the importance of watershed management projects for the development and management of natural resources, the enhancement of the efficiency of these activities is e...

background: a great deal of evidence has indicated that oxidatively modified ldl plays a critical role in the initiation and progression of atherosclerosis. antioxidants that can prevent ldl oxidation may act as antiatherogens. copper is a candidate for oxidizing ldl in atherosclerotic lesions. the binding of copper ions to ldl is usually thought to be a prerequisite for ldl oxidation by copper...