The relation between variables that modulate the probability and the topography of key pecks was examined using a concurrent variable-interval variable-interval schedule with food and water reinforcers. Measures of response probability (response rates, time allocation) and topography (peck duration, gape amplitude) were obtained in 5 water- and food-deprived pigeons. Key color signaled reinforc...

Seven-day tests with Ceriodaphnia dubia are commonly used to estimate toxicity of effluents or receiving waters but can sometimes yield no toxicity outcomes even if pollutants are present. We conducted two sets of full life-cycle tests with C. dubia to (1) determine whether tests with longer exposure periods to low concentrations of contaminants in ambient water might reveal evidence of toxicit...

The Radionuclide Metrology Laboratory (RML) from IFIN-HH organized proficiency tests regarding the measurement of the radioactive content of the food products, water equivalent, with the involved laboratories. RML prepared 14 solid volume sources, of cylindrical shape, containing a mixture of Cs-134 and Cs-137 radionuclides, uniformly distributed in a water equivalent matrix. 13 participants fr...

Vitamins are essential for improving and maintaining human health, and the main source of vitamins is the diet. Measurement of the quantities of water-soluble vitamins in common food materials is important to understand the impact of vitamin intake on human health, and also to provide necessary information for regulators to determine adequate intakes. Liquid chromatography (LC) and mass spectro...

a primary uses from iran rangelands is livestock grazing and the major livestock is sheep. sheep grazing on the slopes above 60%, because of using a lot of energy for grazing operation, caused to not only reduces livestock performance but also increases the risk of erosion. sheep grazing in an area where more than five kilometers away from water sources, due to the prolongation of the march rou...

background physical activity and alteration of temperature as a source of stress may have adverse effects on male reproduction. objectives the aim of this study was to investigate the effect of chronic swimming and standing in cold, warm and lukewarm water on mouse spermatogenesis. materials and methods forty-nine male mice (n = 49) were randomly divided into seven groups: c, control; swc, swim...

irrigated agriculture is an important contributor to the expansion of national food supplies and is expected to play a major role in food security of developing countries. such countries face water crisis for securing the food staples. well designed water resource policies potentially can improve the water allocation and use efficiency as well as the food security objectives. this paper present...