Ribonucleotide reductase from Rhizobium meliloti has been
partially purified and characterized. The enzymatic reduction of
ribonucleotides to deoxyribonucleotides is dependent upon B₁₂ coenzyme
and dihydrolipoate.
B₁₂ coenzyme was more effective than B₁₂ coenzyme analogues
in the reductase reaction. The affinity of the R. meliloti
reductase system for B₁₂ coenzyme was...
The genus Ochodaeus Serville contains approximately sixty
species and is World wide in its distribution. One-half of these
species are known from the Nearctic and Neotropic regions.
Adults of six previously described species common to the
United States have been studied in detail. The mandibles, stridulatory
peg, and male genitalia...
Equipment for strip-till planting is under development in wheat-fallow
rotations in the Columbia Basin of Oregon. This involves the
absence of tillage during the fallow season. At planting time, the
strip-till planter creates a narrow band into which the wheat seed is
placed. The area between the rows is undisturbed...
Twenty-one rice cultivars were evaluated to determine the difference between populations of Sogatodes oryzicola (Muir) (Homoptera: Delphacidae) in Costa Rica and Colombia, Survival, mortality and population development of S. oryzicola on five selected cultivars was used to determine levels of plant resistance. The importance and potential of the parasitoid-predator Haplogonatopus...
Lymphomas and leukemias are the most common cancer in children and young adults and in utero exposure to carcinogens may contribute to the etiology of these cancers. A polycyclic aromatic hydrocarbon (PAH), dibenzo[a,l]pyrene (DBP), was administered to pregnant mice (15 mg/Kg b.w., gavage) on gestation day 17. Significant mortalities in...
While there are many ways to evaluate a user interface design, the user's mental workload and situation awareness (SA) are particularly important considerations in the supervisory control of safety-critical systems. Typically, operators of these systems must monitor high-volume, time-sensitive status information. Interface design for this domain can be challenging and...