Pollarding

Pollard W T, Lee S-Y and Mathies R A 1990 Wavepacket theory of dynamic absorption spectra in femtosecond pump-probe experiments J. Chem. Phys. 92 4012... 

Dexheimer S L, Wang Q, Peteanu L A, Pollard WT, Mathies R A and Shank C V 1992 Femtosecond impulsive excitation of nonstationary vibrational states in bacteriorhodopsin Chem. Phys. Lett. 188 61-6... 

Pollard W T, Dexhelmer S L, Wang Q, Peteanu L A, Shank C V and Mathles R A 1992 Theory of dynamic absorption spectroscopy of nonstatlonary states. 4. Application to 12 fs resonant Raman spectroscopy of bacterlorhodopsin J. Phys. Chem. 96 6147-58... 

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). 

Pollard et al., 1992] Pollard, T. D., Goldberg, I., and Schwarz, W. H. Nucleotide exchange, structure, and mechanical properties of filaments assembled from ATP-actin and ADP-actin. J. Biol. Chem. 267 (1992) 20339-20345... 

Strictly speaking, this expression is correct for a semi-infinite region bounded by a plane wall and containing a gas at rest. Here it is applied to a bounded region surrounded by a curved wall, and the molecules have a drift velocity parallel to che wall. Knudsen was concerned that this drift velocity might invalidate the treatment, but Pollard and Present [8] showed Chat this is not che case. 

Though by no means a complete theory, this is at least a reasonable explanation of the Knudsen minimum, and it then remains to explain why the minimum is not observed for flow through porous media. Pollard and Present attributed this to the limited length/diameter ratio of the channels in a typical porous medium and gave a plausible argument in favor of this view. 

Draper and Pollard [Science 109 448 1949] added 12% water, 0.1% aluminium (can also use zinc), and 0.05% NaHC03 to phenol, and distd at atmospheric pressure until the azeotrope was removed. The phenol was then distd at 25mm. Phenol has also been dried by distn from the benzene soln to remove the water- benzene azeotrope and the excess benzene, followed by distn of the phenol at reduced pressure under nitrogen. Processes such as this are probably adequate for analytical grade phenol which has as its main impurity water. Phenol has also been crystd from pet ether/ benzene or pet ether (b 40-60°). Purified material is stored in a vacuum desiccator over P2O5 or CaS04. 

Pollard, Eniest 1., Synchronous Motors. . . Avoid Torsional Vibration Problems, Hydrocarbon Processing, February 1980, pp. 97-102. 

Pollard, Ernest L, Torsional Vibration Due to Induction Motor Transient Starling Torque, undated manuscript. 

An early account of UHV and its requirements is by Redhead et al. (1962) an even earlier summary of progress in vacuum technology, with perhaps the first tentative account of UHV, was by Pollard (1959). A lively popular account is by... 

Pollard, J. (1959) Progress in vacuum technology. Rep. Prog. Phys. 22, 33. 

Pollard, E. L, Synchronous Motors—Avoid Torsional Vibration Problems, Hydrocarbon Processing, p. 97, Eeb. (1980). 

Refs 1) Anon, EngrgDesHdbk, Solid Propellants Part One , AMCP 706-175 (Sept 1964), 13-14 2) F.B. Pollard J.H. Arnold, Jr,... 

Pollard J.H. Arnold, Aerospace Ordnance Handbook , Prentice-Hall, Englewood Cliffs, NJ (1966), 270-74 5) Merck (1968), 727-R... 

Pollard Explosive. A mixt of S, paraffin, and either a nitrate or chlorate Ref Daniel (1902), 635... 

Pollard s Test for Stability of Propellants. This test, proposed in 1924—25, is based upon the action of nitric peroxide on colloidal Ag oxide Procedure. A current of air is passed over a sample of proplnt in storage into a colloidal soln of Ag oxide. If free nitrogen peroxide is present, it reacts with the colloid and decreases the amt of light diffused by it. The larger the decrease, the higher the amt of N02 present, and the more decompd is the proplnt Ref Reilly (1938), 80... 

More than 50 proteins have been discovered in the cytosol of nonmuscle cells that bind to actin and affect the assembly and disassembly of actin filaments or the cross-linking of actin filaments with each other, with other filamentous components of the cytoskeleton, or with the plasma membrane. Collectively, these are known as actin-binding proteins (ABPs). Their mechanisms of actions are complex and are subject to regulation by specific binding affinities to actin and other molecules, cooperation or competition with other ABPs, local changes in the concentrations of ions in the cytosol, and physical forces (Way and Weeds, 1990). Classifications of ABPs have been proposed that are based on their site of binding to actin and on their molecular structure and function (Pollard and Cooper, 1986 Herrmann, 1989 Pollard et al., 1994). These include the following ... 

Machesky, L.M. Pollard, T.D. (1993). Profilin as a potential mediator of membrane-cytoskeleton communication. Trends Cell Biol. 3, 381-385. 

Pollard, T.D. Cooper, J.R. (1986). Actin and actin-binding proteins. A critical evaluation of mechanisms and functions. Ann. Rev. Biochem. 55, 987-1035. 

---