55 research outputs found
AN ANALYSIS OF H-THYMIDINE DISTRIBUTION THROUGHOUT THE SHOOT APICAL MERISTEM OF ARABIDOPSIS THALIANA (L.) HEYNH
Sequential autoradiographed sections through the shoot apical meristem of Arabidopsis thaliana treated for six hours with a solution of H/sup 3/- thymidine in combination with 0.1% Tween 20 and dilute mineral solution reveal a differential pattern of labeling, indicative of differential rates of DNA synthesis. This pattern corresponds to the histological zonation of the apex and reveals a sub-apical block of cells in which the amount of incorporation is significantly lower than in the adjacent flank cells. (auth
USDA Plant Genome Research Program
The U.S. Congress appropriated funds in 1991 for the USDA Plant Genome Research Program, four years after its initial conception in 1987. The goal of the USDA Plant Genome Research Program is to improve plants (agronomic, horticultural, and forest tree species) by locating marker DNA or genes on chromosomes, determining gene structure, and transferring genes to improve plant performance with accompanying reduced environmental impact to meet marketplace needs and niches. The Plant Genome Research Program is one program with two parts: National Research Initiative and Plant Genome Database (PGD). The PGD is now a real and functioning information and data resource for agricultural and other plant science genome researchers, and it is in the public domain. Additional progress is given according to major plant groups. The PGD is a suite of several information products produced at the National Agricultural Library (NAL) in collaboration with the Agricultural Research Service and Forest Service species coordinators
Optimizing topological cascade resilience based on the structure of terrorist networks
Complex socioeconomic networks such as information, finance and even
terrorist networks need resilience to cascades - to prevent the failure of a
single node from causing a far-reaching domino effect. We show that terrorist
and guerrilla networks are uniquely cascade-resilient while maintaining high
efficiency, but they become more vulnerable beyond a certain threshold. We also
introduce an optimization method for constructing networks with high passive
cascade resilience. The optimal networks are found to be based on cells, where
each cell has a star topology. Counterintuitively, we find that there are
conditions where networks should not be modified to stop cascades because doing
so would come at a disproportionate loss of efficiency. Implementation of these
findings can lead to more cascade-resilient networks in many diverse areas.Comment: 26 pages. v2: In review at Public Library of Science ON
Mitomycin C induced leaf mosaicism in Glycine max (L.) Merrill in relation to the post-germination age of the seed
Molecular and cytological characteristics of nuclear DNA and chromatin for angiosperm systematics: Basic data forHelianthus annuus (Asteraceae)
DNA content, heterochromatin, mitotic index, and growth in perennial and annualAnthemidea (Asteraceae)
Nuclear DNA changes within Helianthus annuus L.: cytophotometric, karyological and biochemical analyses
- …