The effects of increased photosynthetic active radiation (PAR), UV radiation (UVR), and nutrient supply on photosynthetic activity, pigment content, C:N ratio and biomass yield were studied in tank cultivated Gracilaria conferta (Rhodophyta). Electron transport rate (ETR) and biliprotein content were higher under high nutrient supply (HNS), obtained from fishpond effluents, compared to low nutr...

When cells are starved of their substrate, many nutrient transporters are induced. These undergo rapid endocytosis and redirection of their intracellular trafficking when their substrate becomes available again. The discovery that some of these transporters also act as receptors, or transceptors, suggests that at least part of the sophisticated controls governing the trafficking of these protei...

Nutrient uptake by roots often involves substrate-dependent regulated nutrient transporters. For robust uptake, the system requires a regulatory circuit within cells and a collective, coordinated behaviour across the tissue. A paradigm for such systems is boron uptake, known for its directional transport and homeostasis, as boron is essential for plant growth but toxic at high concentrations. I...

Submarine groundwater discharge (SGD) nutrient fluxes from un-sewered suburban landscapes pose a significant eutrophication risk to coastal waters. In unconsolidated coastal aquifers, nutrients recharged to groundwater undergo diffuse discharge to the coastline during SGD. Defining pathways of nutrient attenuation is required for land management professionals to take effective nutrient remediat...

Renal proximal tubular cells constantly recycle nutrients to ensure minimal loss of vital substrates into the urine. Although most of the transport mechanisms have been discovered at the molecular level, little is known about the factors regulating these processes. Here, we show that mTORC1 and mTORC2 specifically and synergistically regulate PTC endocytosis and transport processes. Using a con...

Chronic energy restriction (ER) dramatically enhances intestinal absorption of nutrients by aged mice. Do adaptations in nutrient absorption develop only after extended ER or immediately after its initiation? To determine the time course of adaptations, we measured rates of intestinal glucose, fructose and proline transport 1-270 d after initiation of ER (70% of ad libitum) in 3-mo old mice. Mi...

AIM We examined the effect of proinflammatory and anti-inflammatory interleukins on jejunal nutrient transport and expression of the sodium-glucose linked cotransporter (SGLT-1). METHODS 3-O-methyl glucose and L-proline transport rates were examined in New Zealand White rabbit stripped, short circuited jejunal tissue. The effects of the proinflammatory cytokines interleukin (IL)-1alpha, IL-6,...

A numerical model is developed to examine coastal groundwater processes in a sandy beach, including the effects of tidal fluctuations, saltwater intrusion into an aquifer, and dynamics in unsaturated layers. The simulation results indicate: 1) ‘Local circulation’ is clearly formed in the aquifer near the shoreline owing mainly to tidal oscillations. 2) The circulation induces a landward bending...

The Na+-K+-ATPase, localized in the basolateral membrane of enterocytes plays a major role in nutrient transport in the small intestine by transferring K+ ions into and Na+ out of the cell. Within the enterocyte, homeostasis is maintained by active exclusion of Na from the cell by the Na+,K+-adenosine triphosphatase (ATPase) or sodium pump. Because much of the intestinal nutrient transport is b...

The excessive application of manure on cropland areas can cause nutrients to accumulate near the soil surface and increase nutrient transport by overland flow. Inverting soils with high surface nutrient content could reduce runoff nutrient transport. This study was conducted to measure the effects of moldboard plowing on the redistribution of nutrients within the soil profile and nutrient trans...