In the planktonic crustacean Daphnia magna (Branchiopoda, Cladocera), different views exist on the mechanism of respiratory gas exchange, ranging from gill breathing to general integumentary respiration. The presumed structures for specialized gas exchange are located ventrally within the filter chamber, which is continuously perfused with the ambient medium for food gathering. To localize resp...

abstractin this study, the tensile force requirement, to separate the grain paddy was measured. the velocities of grain paddy it 100, 200, 300, 400, and 500 mm/min, and force requirement to failure stem at 100, 300, and 500 mm/min velocities was measured by using instron device. the data was analyzed using a completely randomized design. the results showed that velocity had a significant effect...

irrigation requirement equals the difference between water requirement and effective rainfall which can be estimated by considering the water application efficiency. the values of water requirement and irrigation requirement of sugar beet have been reported using netwat program in different regions ofiran. however, the mean values were used in this program; therefore the values of water and irr...

During the 4 years 1977-80, 14 infants developed retrolental fibroplasia (RLF) in the neonatal unit at this medical centre. All were very low birthweight (VLBW) infants who weighed 1500 g or less at birth. The incidence of RLF was 3.5% for all VLBW infants admitted for neonatal intensive care and 4.7% for VLBW survivors. The mean birthweight of the affected infants was 970 (range 730-1310) g an...

The recent detection of heterotrophic nitrogen (N(2)) fixation in deep waters of the southern Californian and Peruvian OMZ questions our current understanding of marine N(2) fixation as a process confined to oligotrophic surface waters of the oceans. In experiments with Crocosphaera watsonii WH8501, a marine unicellular diazotrophic (N(2) fixing) cyanobacterium, we demonstrated that the presenc...

the quality of the river water is assessed in different months in different stations to evaluate the change in the quality in re1ation with the various point sources along the river. thirteen parameters were measured in the samples manually taken from three meters off shore in 20 cm. depth in four points representing the quality in four reaches under consideration. the results revealed that nat...