Two balance trials were conducted to examine the response in metabolizable energy and metabolizability of both fat and amino acids to graded levels of zinc bacitracin (ZnB; Albac registered trade name of Alpharma, Oslo, Norway) in practical broiler and layer diets varying in their nutrient density. Broiler diets were supplemented with either 0, 20, or 50 mg ZnB/kg and layer diets were supplemen...

Herbivores generally have strong structural and compositional effects on vegetation, which in turn determines the plant forage species available. We investigated how selected large mammalian herbivore assemblages use and alter herbaceous vegetation structure and composition in a southern African savanna in and adjacent to the Kruger National Park, South Africa. We compared mixed and mono-specif...

Shifts from productive kelp beds to impoverished sea urchin barrens occur globally and represent a wholesale change to the ecology of sub-tidal temperate reefs. Although the theory of shifts between alternative stable states is well advanced, there are few field studies detailing the dynamics of these kinds of transitions. In this study, sea urchin herbivory (a 'top-down' driver of ecosystems) ...

We compared the phenotypic plasticity of two early successional forbs of nutrient-poor mobile dunes (Agriophyllum squarrosum and Corispermum macrocarpum) and two later successional forbs (weeds) of stabilized, higher nutrient dunes and cropland (Chenopodium acuminatum and Salsola collina) to variations in environmental factors. A controlled (including soil nutrients, water, and population densi...

Nearly 50 yr ago, the Michaelis-Menten (MM) model, originally derived for enzyme kinetics, was adapted to characterize microbial nutrient uptake and has become a framework for defining microbial traits in competition theory, evolutionary dynamics, and ocean ecosystem models. We provide theoretical evidence that microbial traits and environmental properties are not appropriately distinguished in...

Consumption patterns are changing globally. As a result both researchers and policy makers require simple, easy to use measures of diet quality. The Healthy Eating Index (HEI) was developed as a single, summary measure of diet quality. The original HEI was a ten component index based on the US Dietary Guidelines and the Food Guide Pyramid. Research on the HEI indicates that the index correlates...

The aim of this study is to provide understanding of microgravity effects on important food-borne bacteria, Escherichia coli O157:H7 ATCC 35150, ATCC 43889, and ATCC 43895, cultured in nutrient-rich or minimal medium. Physiological characteristics, such as growth (measured by optical density and plating), cell morphology, and pH, were monitored under low-shear modeled microgravity (LSMMG; space...

[1] Using in situ data from 88 cruises from 1987 to 2009 in the East China Sea, downstream nutrient flux (the product of velocity and nutrient concentration) and nutrient transport (integration of flux over a section) by Kuroshio were examined. The presence of a maximum nutrient flux core in the middle layer was confirmed. Seasonal variation in the nutrient flux was not significant and was much...

A 2 × 4 factorial experiment was conducted to determine the effects of dietary nutrient density on growth performance, small intestinal epithelial phosphate transporter expression, and bone mineralization of broiler chicks fed with diets with different nutrient densities and nonphytate phosphorus (NPP) levels. The broilers were fed with the same starter diets from 0 to 21 days of age. In the gr...