To investigate the relation between cell division and expansion in the regulation of organ growth rate, we used Arabidopsis thaliana primary roots grown vertically at 20 degreesC with an elongation rate that increased steadily during the first 14 d after germination. We measured spatial profiles of longitudinal velocity and cell length and calculated parameters of cell expansion and division, i...

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We investigated the effects of photon fluence rate on internode elongation in fully de-etiolated plants growing under sunlight. Our goal was to find out whether perception by the stetns of fluence rate changes related to canopy density tnay be involved in the modulation of internode growth in canopies formed by plants of sitnilar stature (e.g. crop stands). Using Datuta ferox L. and Sinapis alb...

It has been postulated that human tendons are viscoelastic and their mechanical properties time-dependent. Although Achilles tendon (AT) mechanics are widely reported, there is no consensus about AT viscoelastic properties such as loading rate dependency or hysteresis, in vivo. AT force-elongation characteristics were determined from 14 subjects in an ankle dynamometer at different loading rate...

The present debate on the validity of the "acid-growth theory" of auxin (indole-3-acetic acid, IAA) action concentrates on the question of whether IAA-induced proton excretion into the cell wall is quantitatively sufficient to provide the shift in pH that is required to explain IAA-induced growth (see D.L. Rayle, R.E. Cleland [1992] Plant Physiol 99:1271-1274 for a recent apologetic review of t...

Differentiation of the wing skeleton is clearly visible in whole mounts from stage 24. It proceeds in proximo-distal and postero-anterior sequence. It is possible to map the part of the limb giving rise to each skeletal element as it appears and subsequently. This enables one to estimate: (a) a rate of elongation curve for each segment level, (b) the intrinsic rate of change of elongation of th...

background: elongation factor-1, a conserved nuclear protein coding gene was used to identify iranian sandfly species. the phlebotomine sandfies are the vectors of the parasitic protozoan leishmania, the causative agents of leishmaniasis, in iran. methods: seven sets of primers were tried. pcr amplification of elongation factor-1 was successfully achieved for all 14 species of iranian sandfli...

the first step to quantify crop phenology is precise estimation of the parameters, which affect it. these parameters are mainly temperature and photoperiod. this study was conducted with eight sowing dates to quantify response of stem elongation rate (ser) to temperature and photoperiod in wheat (tajan cultivar). the regression models fitted to ser against temperature were flat, logistic, quadr...

eight genotypes of spring safflower (carthamus tinctorius l.) were evaluated for several physiological traits under stress and non-stress water regimes. data were analyzed using principal factor analysis. the factor analysis technique extracted six factors under non-stress conditions. six factors explained about 80% of the total variation, and only 40% of the variance was accounted for by the f...

Capping protein (CP) is an integral component of Arp2/3-nucleated actin networks that drive amoeboid motility. Increasing the concentration of capping protein, which caps barbed ends of actin filaments and prevents elongation, increases the rate of actin-based motility in vivo and in vitro. We studied the synergy between CP and Arp2/3 using an in vitro actin-based motility system reconstituted ...