Cellular elongation

The most rapidly growing parts of the plant contain the greatest concentrations of lAA - in the tip of the coleoptile, in buds and in the tips of leaves and roots (24). The concentration of auxin drops from the tip of the coleoptile to the base. From the base of the coleoptile the concentration of auxin increases until it reaches a peak at the root tip. The amount of auxin in the shoot tip, however, is usually much greater than in the tip of the root. In fact, the concentration of auxin which promotes cellular elongation in the shoot appears to be too great for the root, and somehow results in actual inhibition of cell elongation in the root (25). 

The known biological effects of auxin are numerous. In addition to cellular elongation, apical dominance and root initiation, the more important effects include callus formation, parthenocarpy, phototropism and geotropism. 

Kawaguchi, Y., Matsumura, T., Roizman, B. and Hirai, K., Cellular elongation factor Idelta is modified in cells infected with representative alpha-, beta-, or gammaherpesvirnses. J. Virol, 73,4456-4460 (1999). 

Mechanical Properties and Structural Performance. As a result of the manufacturing process, some cellular plastics have an elongated cell shape and thus exhibit anisotropy in mechanical, thermal, and expansion properties (35,36). Efforts are underway to develop manufacturing techniques that reduce such anisotropy and its effects. In general, higher strengths occur for the paraHel-to-rise direction than in the perpendicular-to-rise orientation. Properties of these materials show variabiUty due to specimen form and position in the bulk material and to uncertainty in the axes with respect to direction of foam rise. Expanded and molded bead products exhibit Httie anisotropy. 

A primer is a very special sequence, which plays an important role in duplication, (i) In RNA, it is a short sequence that is paired with one strand of DNA and provides a free 3 -OH terminus at which a DNA polymerase starts synthesis of a deoxyribonucleotide chain, (ii) In DNA, it is another short sequence, which is complementary to a sequence of messenger RNA and allows reverse transcriptase to start copying the adjacent sequences of mRNA. (iii) In retroviruses, it is a cellular transfer RNA whose elongation initiates RNA-directed DNA synthesis by the DNA polymerase. 

Every single-stranded DNA molecule has two ends (5 and 3 ) whose chemical and biological properties differ. In double-stranded DNA, the two strands are always antiparallel, i.e., their 3 and 5 ends are in opposite orientation to one another. Cellular enzymes known as DNA polymerases, which elongate these... 

ISO 527-4 1997 Plastics - Determination of tensile properties - Part 4 Test conditions for isotropic and orthotropic fibre-reinforced plastic composites ISO 527-5 1997 Plastics - Determination of tensile properties - Part 5 Test conditions for unidirectional fibre-reinforced plastic composites ISO 1798 1997 Flexible cellular polymeric materials - Determination of tensile strength and elongation at break... 

ISO 2440 1997 Flexible and rigid cellular polymeric materials - Accelerated ageing tests ISO 6914 2004 Rubber, vulcanized - Determination of ageing characteristics by measurement of stress at a given elongation... 

ISO 2285 2001 Rubber, vulcanized or thermoplastic - Determination of tension set under constant elongation, and of tension set, elongation and creep under constant tensile load ISO 7616 1986 Cellular plastics, rigid - Determination of compressive creep under specified load and temperature conditions... 

Hsieh, C.L. (1997) Stability of patch methylation and its impact in regions of transcriptional initiation and elongation. Molecular and Cellular Biolc, 17, 5897-5904. 

---