Information on sediment and nutrient export from catchments and about related erosive processes is required by catchment managers and decision-makers. Many models exist for the consideration of these processes. However, these models differ greatly in terms of their complexity, their inputs and requirements, the processes they represent and the manner in which these processes are represented, th...

Apportioning sources, assessing flow pathways, and quantifying the interaction between source transport factors are critical for decreasing nutrient loss from agricultural catchments. In this study, water, nutrient, tracer (δ18O, electrical conductivity) fluxes were measured over two years a tile-drained field in Indiana, USA to quantify linkages among water management practices, delivery tile ...

Brazilian savanna is a seasonally dry biome, highly diverse and distributed mainly on nutrient-limited soils. Interactions between water stress nutrient availability are important evolutionary filters in these environments. Previous evidence indicated that reducing the nutritional limitation increases growth rate, optimizes transport decreases stomatal conductance woody plants. However, anatomi...

Fetal macronutrient requirements for oxidative metabolism and growth are met by placental transport of glucose, amino acids, and, to a lesser extent that varies with species, fatty acids. It is becoming possible to relate the maternal-fetal transport kinetics of these molecules in vivo to the expression and distribution of specific transporters among placental cell types and subcellular membran...

Epithelial cells line virtually every organ cavity in the body and are important for vectorial transport through epithelial monolayers such as nutrient uptake or waste product excretion. Central to these tasks is the establishment of epithelial cell polarity. During organ development, epithelial cells set up two biochemically distinct plasma membrane domains, the apical and the basolateral doma...

Nutrient availability in ecosystems is patchy both in space and in time. Whereas temporal trends have often been studied, less information exists on spatial patterns of nutrient availability, particularly in aquatic ecosystems. The goals of this study were (1) to describe and quantify patterns of nutrient concentration in surface waters of an arid land stream and (2) to compare spatial patterns...