Stem Number

Jerusalem artichoke stems can grow to 3 m or more in height, though most clones are shorter. Dwarf clones have been selected (Zubr and Pedersen, 1993). The stems are stout and heavily trichomed when young. Initially the stems are quite succulent but become woody over time. Branches vary in number and position on the main stems. The stems arise directly from the seed tuber, with branches forming at nodes on the stem. Basal branches may form underground and at the soil surface appear to be stems hence, estimates of stem number per plant are variable. 

Most cultivars are erect, though a small number are initially prostrate. The prostrate clones begin to grow in an erect manner after a certain number of nodes (i.e., generally the second, third, or fourth node, depending upon the clone) (Pas ko, 1973). 

Pas ko (1973) categorized clones into three classes based upon the number of stems arising from the seed tuber (1) 3 (strong), (2) 2 to 3 stems (intermediate), and (3) a single stem (weak). Multiple stems facilitate a rapid increase in leaf area index early in the development of the plant. The number of stems also varies with agronomic practices and seed tuber size. Some clones are highly variable in the number of stems produced, while others are less so. 

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AC 94377. The compound l-(3-chlorophthalimide) cyclohexanecarboxamide [51971 -67-6] (Table 3) (45), also known as AC 94377, is a phthalamide that has plant growth regulating properties. It is relatively nontoxic so that its use in floricultural crops appears to be safe. It is mainly used to control stem length and stem numbers in hybrid tea roses (23). However, it has very limited use and is stiH experimental. 

Stem number is partly determined by the size of the seed tuber (Barloy, 1988 Louis, 1985) and is closely related to the early canopy development and leaf area index (Baillarge, 1942 Cors and Falisse, 1980). Branching type is genetically controlled, although the number of branches is largely regulated by plant density. 

As illustrated by Figure 10.1a, approximately nine stems were formed by the fourth week after planting however, stem number is not static. The number declined to an average of four to six by the end of the season, with losses typically caused by shading of smaller, less vigorous stems. 

Fig. 4.10 A-F. Diagrams illustrating the effects of various treatments on the differentiation of phloem fibers in Coleus stems. Numbers beside the internodes show the average number of fibers ( standard error) in the adjacent half transverse section. The plants of diagram A were untreated. On the day the A plants were collected, the axillary shoots and indicated leaves of the other treatments were excised. Plants of B F were harvested 2 weeks later. (Aloni 1976)...

Redundant, isomorphic structures have to be eliminated by the computer before it produces a result. The determination of whether structures are isomorphic or not stems from a mathematical operation called permutation the structures are isomorphic if they can be interconverted by permutation (Eq. (6) see Section 2.8.7). The permutation P3 is identical to P2 if a mathematical operation (P ) is applied. This procedure is described in the example using atom 4 of P3 (compare Figure 2-40, third line). In permutation P3 atom 4 takes the place of atom 5 of the reference structure but place 5 in P2. To replace atom 4 in P2 at position 5, both have to be interchanged, which is expressed by writing the number 4 at the position of 5 in P. Applying this to all the other substituents, the result is a new permutation P which is identical to P]. 

Tlere, y Is the friction coefficien t of the solven t. In units of ps, and Rj is th e random force im parted to th e solute atom s by the solvent. The friction coefficien t is related to the diffusion constant D oflh e solven l by Em stem T relation y = k jT/m D. Th e ran doin force is calculated as a ratulom number, taken from a Gaussian distribn-... 

Ah initio methods pose problems due a whole list of technical difficulties. Most of these stem from the large number of electrons and low-energy excited state. Core potentials are often used for heavier elements to ease the computational requirements and account for relativistic elfects. 

Most of the polymer s characteristics stem from its molecular stmcture, which like POE, promotes solubiUty in a variety of solvents in addition to water. It exhibits Newtonian rheology and is mechanically stable relative to other thermoplastics. It also forms miscible blends with a variety of other polymers. The water solubiUty and hot meltable characteristics promote adhesion in a number of appHcations. PEOX has been observed to promote adhesion comparable with PVP and PVA on aluminum foil, cellophane, nylon, poly(methyl methacrylate), and poly(ethylene terephthalate), and in composite systems improved tensile strength and Izod impact properties have been noted. 

Vegetable fibers are classified according to their source ia plants as follows (/) the bast or stem fibers, which form the fibrous bundles ia the inner bark (phloem or bast) of the plant stems, are often referred to as soft fibers for textile use (2) the leaf fibers, which mn lengthwise through the leaves of monocotyledonous plants, are also referred to as hard fibers and (J) the seed-hair fibers, the source of cotton (qv), are the most important vegetable fiber. There are over 250,000 species of higher plants however, only a very limited number of species have been exploited for commercial uses (less than 0.1%). The commercially important fibers are given ia Table 1 (1,2). 

Flow Past Bodies. A fluid moving past a surface of a soHd exerts a drag force on the soHd. This force is usually manifested as a drop in pressure in the fluid. Locally, at the surface, the pressure loss stems from the stresses exerted by the fluid on the surface and the equal and opposite stresses exerted by the surface on the fluid. Both shear stresses and normal stresses can contribute their relative importance depends on the shape of the body and the relationship of fluid inertia to the viscous stresses, commonly expressed as a dimensionless number called the Reynolds number (R ), EHp/]1. The character of the flow affects the drag as well as the heat and mass transfer to the surface. Flows around bodies and their associated pressure changes are important. 

Electrica.1 Properties. The electrical properties of SF stem primarily from its effectiveness as an electron scavenger. To accomplish electrical breakdown in a dielectric gas, primary electrons must gain sufficient energy to generate appreciable numbers of secondary electrons on molecular impact. Sulfur hexafluoride interferes with this process by capturing the primary electrons, resulting in the formation of SF or SF ions and F atoms (29) ... 

SCE protects mice from G1 death after kradiation and increases the number of surviving mucosal crypt stem cells (186) in a manner similar to lL-1. 

The antitumor activity displayed by the mitosanes and many synthetic aziridines stems from their ability to act as alkylating agents which chemically modify (crosslink) DNA. For this reason, a large number have been screened for antitumor activity, the mechanism of which has been the subject of considerable research effort <75CJC289l). An excellent account of the broad spectrum of biological properties of a multitude of compounds containing the aziridinyl moiety has been published [Pg.93]

While most turbines have a 10-year-availability record in the range of 95 to 99 percent, troubles may develop in any number of places. The most common are vibration, cycling governor, sticking valve stems, leaky packing, temperature bow, erosion of blading, loss of power, and bearing problems. 

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