Horbar JD, Carpenter JH, Buzas J, et al. Collaborative quality improvement to promote evidence based surfactant for preterm infants: a cluster randomised trial. BMJ 2004;329:1004. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....

The biogeographical history of major groups of bees with worldwide distributions have often been explained through hypotheses based on Gondwanan vicariance or long distance dispersal events, but until recently these hypotheses have been very difficult, if not impossible, to distinguish. New fossil data, comprehensive information on Mesozoic and Cenozoic coastline positions and the availability ...

desertification is recognized as a serious environmental threat in iran because of its climatic-geomorphologicconditions. desertification and land degradation in arid, semi-arid, and dry sub-humid regions, is a globalenvironmental problem. accurate assessment of the status and trend of desertification is instrumental in developingglobal strategies to prevent and reverse this problem. the goal o...