Lymphocyte sequestration through S1P lyase inhibition and disruption of S1P gradients

Lymphocyte egress from the thymus and from peripheral lymphoid organs depends on sphingosine 1-phosphate (S1P) receptor-1 and is thought to occur in response to circulatory S1P. However, the existence of an S1P gradient between lymphoid organs and blood or lymph has not been established. To further define egress requirements, we addressed why treatment with the food colorant 2-acetyl-4-tetrahydroxybutylimidazole (THI) induces lymphopenia. We found that S1P abundance in lymphoid tissues of mice is normally low but increases more than 100-fold after THI treatment and that this treatment inhibits the S1P-degrading enzyme S1P lyase. We conclude that lymphocyte egress is mediated by S1P gradients that are established by S1P lyase activity and that the lyase may represent a novel immunosuppressant drug target.     

Zero tillage impacts in India's rice–wheat systems: A review

To date, the most widely adopted resource conserving technology in the Indo-Gangetic Plains (IGP) of South Asia has been zero-tillage (ZT) wheat after rice, particularly in India. The paper reviews and synthesizes the experience with ZT in the Indian IGP. ZT wheat is particularly appropriate for rice–wheat systems in the IGP by alleviating system constraints by allowing earlier wheat planting, helping control the weed Phalaris minor, reducing production costs and saving water. ZT wheat after rice generates substantial benefits at the farm level (US$97 ha⁻¹) through the combination of a ‘yield effect’ (a 5–7% yield increase, particularly due to more timely planting of wheat) and a ‘cost savings effect’ (US$52 ha⁻¹, particularly tillage savings). These benefits explain the widespread interest of farmers and the rapidity of the diffusion across the Indian IGP, further aided by the wide applicability of this mechanical innovation.