"Dream deprivation": effects on dream content

Dream content elicited following the selective deprivation of rapid-eye-movement sleep was intensified compared to that elicited under nondeprivation conditions. This effect was observed both for repressers and for sensitizers, but was significant only for repressers. On nondeprivation nights, the dream periods of sensitizers were shorter and their dreams more intense than those of repressers.     

Oligoribonucleotides: improvement in chromatographic separation

The separation of mixed oligoribonucleotides obtained from enzymatic digestion of soluble RNA into fractions containing mixed oligonucleotides of identical chain length is improved by absence of terminal phosphate. Each fraction may be separated into individual components by ionexchange (Dowex) chromatography. Combination of these two chromatographic procedures yields maximum information on primary structure of the oligonucleotides.     

Carbon monoxide measurements in the troposphere

During the second flight of the space shuttle, the measurement of air pollution from satellites (MAPS) experiment in the OSTA-1 payload acquired approximately 35 hours of radiometric measurements of the carbon monoxide mixing ratio in the middle troposphere, upper troposphere, and lower stratosphere. A gas filter radiometer operating in the 4.67-micrometer band was used to acquire the data over the region from 38 degrees N to 38 degrees S during both daytime and nighttime. The performance of the measurement system was excellent. The data reduced to date indicate the presence of significant gradients in the middle tropospheric carbon monoxide mixing ratio with both latitude and longitude over the North Atlantic, the Mediterranean Sea, and the Middle East. On the basis of comparisons with directly measured values, the accuracy of the measurements is approximately 15 percent. Comparisons of data taken on successive orbits over the same geographic region indicate that the repeatability of the measurements is approximately 5 percent.     

Formation of mixed invasions of waterfowl

It is established that wild and synanthropic waterfowl of the order Anseriformes (gadwell, mallard, graylag goose, teal, garganey, etc.) are possible sources of mixed invasions i.e., an etiological factor in forming and maintaining ill-being of domestic geese with respect to the following diseases: echinostomatidosis, amidostomosis, ganguleterikidosis, thominxosis, streptocarosis, echinuriosis, as well as ectoparasites (bird lice).     

Effects of delay in reapplication of nitrogen fertilizer following cutting silage from a ryegrass sward

Plots of a 2-year-old sward of Merlinda perennial ryegrass received a routine dressing of 100 kg N ha⁻¹ as compound fertilizer in March 1991, followed by further dressings of 100 kg N ha⁻¹ after cuts 1, 2 and 3 in a simulated four-cut silage system, either the same day as cutting or with a delay of 3, 7, 10 or 14 d. Partial irrigation ensured that fertilizer could be taken up immediately. Annual total dry matter yield, the dry matter yield for the experimental cuts 2–4 and their apparent response to N showed no effect of delays of 0–10 d in reapplication of fertilizer, but a significant ( P < 0·01) reduction for 14 d delay. Significantly ( P = 0·001) higher apparent recovery of N in the cut herbage was recorded where reapplication of fertilizer had been delayed by 7 or 10 d (93% and 91% respectively) in comparison with either smaller (0 delay, 78%; 3 d delay, 87%) or greater delay (14 d, 86%). It is suggested that lower recoveries at 0 and 3 d result from the sward's reduced NO₃ uptake following defoliation and that, while in practical situations the conditions may not be as rigorous as those imposed in this experiment, further experiments to determine the fate of N not recovered in the herbage are warranted, so defining management circumstances in which immediate reapplication of N might not be advisable.