Leaves from

Zigmond, 1988). The ATP-hydrolysis that accompanies actin polymerization, ATP —> ADP + Pj, and the subsequent release of the cleaved phosphate (Pj) are believed to act as a clock (Pollard et ah, 1992 Allen et ah, 1996), altering in a time-dependent manner the mechanical properties of the filament and its propensity to depolymerize. Molecular dynamics simulations suggested a so-called back door mechanism for the hydrolysis reaction ATP ADP - - Pj in which ATP enters the actin from one side, ADP leaves from the same side, but Pj leaves from the opposite side, the back door (Wriggers and Schulten, 1997b). This hypothesis can explain the effect of the toxin phalloidin which blocks the exit of the putative back door pathway and, thereby, delays Pi release as observed experimentally (Dancker and Hess, 1990). 

Current is fed into the electrolyzer by means of anodic and cathodic end elements. The anodic compartment of each cell is joined to an independent brine feed tank by means of flanged connections. Chlorine gas leaves each cell from the top, passing through the brine feed tank and then to the cell room collection system. Hydrogen leaves from the top of the cathodic compartment of each cell the cell Hquor leaves the cathodic compartment from the bottom through an adjustable level connection. 

The General Mills mixer—settler (117), shown in Figure 13b, is a pump—mix unit designed for hydrometaHurgical extraction. It has a baffled cylindrical mixer fitted in the base and a turbine that mixes and pumps the incoming Hquids. The dispersion leaves from the top of the mixer and flows into a shallow rectangular settler designed for minimum holdup. 

Cmde gas leaves from the top of the gasifier at 288—593°C depending on the type of coal used. The composition of gas also depends on the type of coal and is notable for the relatively high methane content when contrasted to gases produced at lower pressures or higher temperatures. These gas products can be used as produced for electric power production or can be treated to remove carbon dioxide and hydrocarbons to provide synthesis gas for ammonia, methanol, and synthetic oil production. The gas is made suitable for methanation, to produce synthetic natural gas, by a partial shift and carbon dioxide and sulfur removal. 

The Texaco gasifier and a similar unit developed by The Dow Chemical Company are pressurized entrained gasifiers. At the top pulverized coal is mixed with reaction gas and is blown down into the gasifier. The reaction products leave from the side, and ash is blown down to a water pool where it is quenched. These units have operated at an Eastman Kodak facUity in Kingsport, Tennessee and at the Coolwater power station in California for an integrated combined cycle power plant. 

Lettuce plants were grown under artificial day-light for 12 hours a day. The uptake of POPs was assessed by measuring the amount of Endosulfan compounds in roots and leaves from lettuce plants after 10, 20 and 33 days. In addition, control plants grown in uncontaminated soil were monitored and analysed. 

On leave from the Japan Tobacco i Salt Public Corporation. 

Duhoisia myoporoides. Yields of 3 per cent., mostly hyoscine, have been mentioned, but great variation in nature of alkaloidal content is on record, e.g., hyoscyamine, -hyoscyamine, hyoscine. Hyoscyamine and norhyoscyamine, but no hyoscine. Hyoscine or hyoscyamine or both. dZ-Hyoscine, tigloidine, valeroidine, poroidine and woporoidine present hyoscyamine and norhyoscyamine absent. The limits of these variations, at least as regards the two principal alkaloids, hyoscyamine and hyoscine, have probably been settled by Hills, Trautner and Rodwell, who confirmed the statement of Barnard and Finnemore that in the northern portion of the distribution area of this plant, it yields mainly hyoscine and in the southern section mainly hyoscyamine. In 54 samples of leaves from individual trees they found 0-9 to 4-0 total alkaloids in those from the northern section, with hyoscine as the chief component, and 1-0 to 2-7 from those of the southern section, with hyoscyamine replacing hyoscine. 

Single-pass Tube Side. For these conditions, no baffle is in either the head or the return end of the unit. The tube-side fluid enters one end of the exchanger and leaves from the opposite end. In general, these baffles are not as convenient from a connecting pipe arrangement viewpoint as units with an even number of passes in which the tube-side fluid enters and leaves at the same end of the exchanger. See Figures 10-IC and 10-lG and Table 10-1. 

Exfoliation loss of material in the form of layers or leaves from a solid metal or alloy. 

The wonderful fragrance of leaves from the California bay tree is due primarily to myrcene, a simple terpene. 

Elucidating the stereochemistry of reaction at prochirality centers is a powerful method for studying detailed mechanisms in biochemical reactions. As just one example, the conversion of citrate to (ds)-aconitate in the citric acid cycle has been shown to occur with loss of a pro-R hydrogen, implying that the reaction takes place by an anti elimination mechanism. That is, the OH and H groups leave from opposite sides of the molecule. 

Anti stereochemistry (Section 7.2) The opposite of syn. An anti addition reaction is one in which the two ends of the double bond are attacked from different sides. An anti elimination reaction is one in which the two groups leave from opposite sides of the molecule. 

The composition of the earth s atmosphere differs from day to day, from altitude to altitude, and from place to place. The largest variation is in the concentration of water vapor. Water evaporates continually from the hydrosphere, from the soil, from leaves, from clothes drying, etc. At intervals, parts of the atmosphere become chilled until the dew point or frost point is reached and then any vapor in excess of the saturation amount is precipitated as rain or snow. 

It is a particular pleasure to thank the institutions which provided financial support to this work. These are the Deutsche Forschungsgemeinschaft, the Fonds der Chemischen Industrie, and the Bund der Freunde der Technischen Universitat Miinchen. I am also indebted to Professor H. Schmidbaur, Garching, for his continued interest in our investigations, to Professor G. Muller, Konstanz, for the x-ray structure determinations and to Professor G. Bowmaker, who was on sabbatical leave from Auckland, New Zealand, for critical reading of the manuscript. 

Although halides are common leaving groups in nucleophilic substitution for synthetic purposes, it is often more convenient to use alcohols. Since OH does not leave from ordinary alcohols, it must be converted to a group that does leave. One way is protonation, mentioned above. Another is conversion to a reactive ester, most commonly a sulfonic ester. The sulfonic ester groups tosylate, brosylate, nosylate, and mesylate are better leaving groups than... 

Despite the broad medical potentials reported so far, the total synthesis of triterpene QMs is yet to be reported. On the contrary, the biosynthesis of triterpene QMs has recently been validated as from the oxidosqualene 88 (Scheme 8.16) in the plants including Maytenus aquifolium and Salacia campestris.10S With the assistance of HPLC analysis and isotopic labeling, it was found that triterpene QMs 90 were formed only in the root of these plants from friedelin 89 and similar cyclized intermediates, which were synthesized in the leaves from oxidosqualene by cyclase. 

Walters and Gilmore (16) Incorporated either roots or leaves from fescue Into the sand In the donor pots of a stairstep design. The subsequent circulation of nutrient solution leached chemicals from the donor debris and carried them Into the receiver pots. 

Leaves from the five plants were combined and divided into two equal weight samples. One sample was leached in distilled water for 2 hours at a ratio of 15 gms leaf fresh weight to 100 ml water. The leaf leachate was decanted and used directly in the bioassay. The second sample was ground in a blendor with distilled water at a ratio of 1 gm leaf fresh weight to 100 ml water. After standing for 15 min, the mixture was filtered and the filtrate was used directly in the bioassay. 

Mate is the beverage prepared from the leaves of Ilex paraguariensis, a member of the holly family. The leaves from a number of other members of the Ilex genus are sometimes used along with those from paraguariensis. The species exists in several varieties and, like Camellia sinesis, there is a divergence of opinion concerning their identity and nomenclature. 

On leave from the Department of Chemistry, Ben Gurion University, Beer Sheva, Israel... 

During re-entry, stratified whole-leaf sampling was conducted. Twenty-four leaves from the harvesting zone of the crop were collected in a 500-mL polyethylene bottle in duplicate. Leaf samples were stored at 4 to 7°C in the laboratory until analysis. After analysis, the leaf volume was measured by stereometric volumetry using a method described by Sherle (1970). A linear relationship between leaf volume and leaf area was determined for carnation leafs by measuring leaf area (one-sided) with a LI-COR 3100 (Ll-Cor, Inc. Nebraska). 

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