Theoretical arguments suggest that increased plant productivity may not only increase consumer densities but also their fluctuations. While increased consumer densities are commonly observed in fertilization experiments, experiments are seldom performed at a spatial and temporal scale where effects on population fluctuations may be observed. In this study we used a natural gradient in soil fert...

linear programming is a helpful and applied method for diet formulation based on minimum cost, but the minimum cost does not always mean maximum profit. this study was carried out to introduce a new diet formulation method based upon maximum profit to be replaced for minimum cost method. a total of 400 one-day-old broiler chicks (ross 308) were employed in the study. all broilers were fed simil...

Background: Imbalanced diet, as it may cause micronutrient malnutrition has been known as a causal factor for several chronic diseases. Several studies in Iran have shown that some micro-nutrient deficiencies are prevalent and of high concern. Minerals such as calcium and iron can supply physical and mental health as well as survival, and growth development. In this study, Nutrient density anal...

In this article we consider derive a macroscopic model for root length density evolution, starting from a discrete mesh of roots, using homogenization. In the microscopic model each roots grows vertically according to an ordinary di erential equation. The roots growth rates depend on the spatial repartition of nutrient in the soil, which also evolves in time, leading to a fully coupled nonlinea...

Effects of low-density broiler breeder diets on offspring performance and mortality were studied using 2,100 female and 210 male Cobb 500 breeders. Breeder treatments involved 4 experimental groups and a control group with normal density diets (ND, 2,600 kcal of AME/kg during rearing and 2,800 kcal of AME/kg during laying). In treatment 2, nutrient densities were decreased by 12% (LD12) and 11%...

Nutritional deficiencies or imbalances are suspected contributory factors to several types of human cancers, and perhaps other human diseases related to long-term metabolic derangements. In order to study these more effectively in laboratory animals, it is suggested that the laboratory diets more closely mimic the nutrient density of suspect human diets. Toxicology and carcinogenic data obtaine...

Background: Malnutrition in children including lower nutrient intakes or high density food intakes is of recent world concerns; therefore, determining a simple index that reveals the diet adequacy might be an advantage. Methods: This cross-sectional study was done among 233 children aged 2-5 years old. A 24-hour dietary questionnaire was used to calculate mean adequacy ratio (MAR), naturally nu...

The National Nutrition Survey is a unique survey that provides nationwide information on nutrient intake in Japan. Descriptive statistical data of nutrient intake, which has not been described in annual reports, are summarized in this report. A dataset from the National Nutrition Survey between 1995 and 1999 was used for analyses. The distribution of vitamin A intake had an extremely long right...

background: in order to provide better advice for prevention of obesity and eating disorders among children, there is a need to have more knowledge of their dietary patterns. this study examined meal and snacking patterns of primary school children in tehran. methods: a total of 761 male and female primary school children from all educational areas in tehran were recruited in a cross‑sectional ...