We evaluated differences in the effects of three low-severity spring prescribed burns and four wildfires on nitrogen (N) biogeochemistry in Rocky Mountain headwater watersheds. We compared paired (burned/unburned) watersheds of four wildfires and three spring prescribed burns for three growing seasons post-fire. To better understand fire effects on the entire watershed ecosystem, we measured N ...

Agricultural watersheds in the upper Midwest are the major source of nutrients to the Mississippi River and Gulf of Mexico, but temporal patterns in nutrient export and the role of hydrology in controlling export remain unclear. Here we reporton NO3(-)-N, dissolved reactive phosphorus (DRP), and total P export from three watersheds in Illinois during the past 8-12 years. Our program of intensiv...

Intensive plantation forestry will be increasingly important in the next 50 yr to meet the high demand for domestic wood in the United States. However, forest management practices can substantially influence downstream water quality and ecology. This study analyses, the effect of fertilization on effluent water quality of a low gradient drained coastal pine plantation in Carteret County, North ...

[1] Measurements of solute concentrations from previously unstudied watersheds throughout west Siberia suggest that warming and permafrost degradation will likely amplify the transport of dissolved solids to the Kara Sea and adjacent Arctic Ocean. We present concentrations of Ca, K, Mg, Na, Si, Cl , SO4 2 , HCO3 , inferred alkalinity, and total inorganic solutes (TIS) from 94 streams and rivers...

Automatic segmentation is performed using watersheds of the gradient magnitude and compression techniques. Linear Scale-Space is used to discover the neighbourhood structure and catchment basins are locally merged with Minimum Description Length. The algorithm can form a basis for a large range of automatic segmentation algorithms based on watersheds, scale-spaces, and compression.

1.2 Machine failure A system is composed of 5 components, each of which is either working or broken. Consider an experiment that consists of observing the status of each component, and let the outcome of the experiment be given by the vector (x1, x2, x3, x4, x5), where xi = 1 if component i works and 0 if component i is broken. 1. How many outcomes are in the sample space of this experiment? 2....

Neoplastic transformation is a complex process that results from multiple changes in gene activities. Probably most of these are mutational, i.e. alterations in the genomic structure of DNA, but others may be due to adaptive changes wherein genes are expressed that are inappropriate to a stage of development or differentiation. In this commentary neoplastic development is discussed in the conte...

We studied discharges of organic carbon from eight contiguous small watersheds on the Atlantic Coastal Plain in Maryland for up to 24 yr. Six of these watersheds were second or third order with mixed-land-use, while two were first order (one completely forested and one highly dominated by cropland). These watersheds have perched aquifers, so all groundwater discharges as well as surface runoff ...

le mouvement transversal de la locomotive ou des wagons , appele ie lacet, provient de deux causes principales: -la conicite des bandages -les irregularites de la voie dans ie plan horizontal. on se propose ici d'etudier la premiere cause , ce qui nous conduit a une equation differentielle non lineaire du deuxieme ordre. • l'equation en question est etudiee dans plusieurs cas difftten...