We used a fully factorial experimental design to examine the simultaneous effects of light availability, absolute nutrient (nitrogen and phosphorus) availability, relative N : P availability, and trophic structure on zooplankton community composition and the abundance and stoichiometry of algal producers. During May–June 2000, we created gradients of light and nutrient supply and predation risk...

Sexual eukaryotic organisms are characterized by haploid and diploid nuclear phases. In many organisms, growth and development occur in both haploid and diploid phases, and the relative length of these phases exhibits considerable diversity. A number of hypotheses have been put forward to explain the maintenance of this diversity of life cycles and the advantage of being haploid versus that of ...

A pot experiment was carried out in the net house of Bangladesh Institute of Nuclear Agriculture (BINA) to study nutrient content and their uptake by different rice varieties (NERICA-1, NERICA-10 and BRRI dhan48) in response to different levels of arsenic (As) under varying moisture regimes. Three levels of As were added viz. 0, 30, 60 ppm to the pot soil from sodium arsenate (Na2HAsO4. 7H2O). ...

Bacteria often encounter environments where nutrient availability is limited, and they must adapt accordingly. To identify Pasteurella multocida genes that are differentially expressed during nutrient limitation, we utilized whole-genome microarrays to compare levels of gene expression during growth in rich and minimal media. Our analysis showed that the levels of expression of a total of 669 g...

Rapid environmental change at high latitudes is predicted to greatly alter the diversity, structure, and function of plant communities, resulting in changes in the pools and fluxes of nutrients. In Arctic tundra, increased nitrogen (N) and phosphorus (P) availability accompanying warming is known to impact plant diversity and ecosystem function; however, to date, most studies examining Arctic n...

Cells must regulate the abundance and activity of numerous nutrient transporters in different organelle membranes to achieve nutrient homeostasis. As the recycling center and major storage organelle, lysosomes are essential for maintaining nutrient homeostasis. However, very little is known about mechanisms that govern the regulation of its membrane proteins. In this study, we demonstrated that...

the objective of this study was to evaluate the effect of nacl application on yield and some growth parameters of tomato (lycopersicum esculentum cv. falkato). the study was carried out during september 2005 until may 2006 using soilless culture. the plants were fed with a complete nutrient solution, of electrical conductivity at levels of (a) 1.5 (control) (b) 3.5, (c) 5.5, (d) 6.5 dsm-1 repli...

Prymnesium parvum is a globally distributed prymnesiophyte alga commonly found in brackish water marine ecosystems and lakes. It possesses a suite of toxins with ichthyotoxic, cytotoxic and hemolytic effects which, along with its mixotrophic nutritional capabilities, allows it to form massive Ecosystem Disruptive Algal Blooms (EDABs). While blooms of high abundance coincide with high levels of ...

As the Lyme disease bacterium Borrelia burgdorferi traverses its enzootic cycle, alternating between a tick vector and a vertebrate host, the spirochete must adapt and persist in the tick midgut under prolonged nutrient stress between blood meals. In this study, we examined the role of the stringent response in tick persistence and in regulation of gene expression during nutrient limitation. Nu...

Increased nutrient mobilization by human activities represents one of the greatest threats to global ecosystems, but its effects on ecosystem productivity can differ depending on food web structure. When this structure facilitates efficient energy transfers to higher trophic levels, evidence from previous large-scale enrichments suggests that nutrients can stimulate the production of multiple t...