The in vivo T cell response to persistent Ag contains a hyporesponsive phase following an initial expansion and subsequent partial deletion of the responding cells. The mechanism(s) responsible for this tolerance process is poorly understood. In this study, we describe a new paired transgenic model (TCR and Ag), which within 7-14 days produces 20-40 million hyporesponsive T cells. This state is...

it has often been stated or implied that grazing is an important factor in the land degradation process, a suggestion supported by various research projects, and this study investigated the effect of livestock grazing on stem height, crowncover, production, basal diameter, stem biomass, litter, leaf-stem index (leaf to stem weight) , root diameter and weight and seed production per individual o...

this experiment was conducted to evaluation the effects of different levels of untreated and treated green grape leaf with urea on performance, egg quality traits and blood parameters of laying hens. in this experiment 192 hy-line (w-36) laying hens, 35 to 46 wk of age were divided in to 4 treatments with 4 replicates (12 birds per replicate) in a completely randomized design experiment. the tr...

Morus alba leaf methanolic extract and its fractions (chloroform, butanol, and aqueous fractions) were found to inhibit NO production in LPS-activated RAW264.7 macrophages without an appreciable cytotoxic effect at concentration from 4 to 100 microg/ml. LPS-induced PGE2 production was significantly reduced only by butanol fraction. In addition, M. alba leaf extract and its fractions significant...

Plants of nutrient-poor, arid environments often have leaf traits that include small size, sclerophylly, long life span, low nutrient concentration, and low photosynthetic rate. Hence, the success of two large-leaved palmettos in peninsular Florida's seasonally xeric, nutrient-impoverished uplands seems anomalous, given that their leaves are orders of magnitude larger than the leaves of sympatr...

Senescence represents the final developmental act of the leaf, during which the leaf cell is dismantled in a coordinated manner to remobilize nutrients and to secure reproductive success. The process of senescence provides the plant with phenotypic plasticity to help it adapt to adverse environmental conditions. Here, we provide a comprehensive overview of the factors and mechanisms that contro...

The regulatory role of ethylene in leaf senescence was studied with excised tobacco leaf discs which were allowed to senesce in darkness. Exogenous ethylene, applied during the first 24 hours of senescence, enhanced chlorophyll loss without accelerating the climacteric-like pattern of rise in both ethylene and CO(2), which occurred in the advanced stage of leaf senescence. Rates of both ethylen...

in this research, possibility of bulblet production from different cuttings including leaf, leaf-bud and leafy-stem of lilium oriental hybrid cv. ‘star gazer’ evaluated under different levels of indole-3-butyric acid (iba) with 0, 250, 500, 750 and 1000 mg per liter (ppm). the cuttings were taken from stems which grown from cold treated bulbs in early october. a factorial experiment was done in...

it has often been stated or implied that grazing is an important factor in the land degradation process, a suggestion supported by various research projects, and this study investigated the effect of livestock grazing on stem height, crowncover, production, basal diameter, stem biomass, litter, leaf-stem index (leaf to stem weight) , root diameter and weight and seed production per individual o...