we studied the role of nutrients on various aspects of the periphyton community in artificialstreams. dry mass, ash-free dry mass, chlorophyll a and biovolume of the periphyton community weremeasured under 3 different nutrient regimes, including one from natural streams as a control and twowhich were enriched with n and n+p. results of this experiment indicate that the standing crop of theperip...

Two antibiotics isolated from a culture MA-2465 were identified as aureothin and labilomycin, the chemical structures of which had been reported previously. It was also concluded that mycolutein and pulvomycin isolated as antibiotics in 1955 and 1957 respectively are also identical with aureothin and labilomycin. A cursory study of MA-2465 indicates that it is distinctly different from the cult...

let e be the ellipse with major and minor radii a and b respectively, and pbe its perimeter, then p = lim 4 tan(p/n)(a + b + 2) σ a2 cos2 (2k-2)pi/n+ sin2 (2k-2)pi/n; where n = 2m. so without considering the limit, it gives a reasonable approxi-mation for p, it means that we can choose n large enough such that the amountof error be less than any given small number. on the other hand, the formul...