Doolittle

Doolittle L R 1986 A semiautomatic algorithm for Rutherford backscattering analysis Nucl. Instrum. Methods B 15 227... 

The inverted differential U tube, in which the manometric fluid may be a gas or a hght liquid, can be used to measure hquid pressure differentials, especially for the flow of slurries where solids tend to settle out. Additional details on the use of this manometer can be obtained from Doolittle (op. cit., p. 18). 

Several micromanometers, based on the liquid-column principle and possessing extreme precision and sensitivity, have been developed for measuring minute gas-pressure differences and for cahbrating low-range gauges. Some of these micromanometers are available commercially. These micromanometers are free from errors due to capillarity and, aside from checking the micrometer scale, require no cahbration. See Doolittle, op. cit., p. 21. 

A partially filled horizontal tank requires the determination of the partial volume of the heads. The Lnkens catalog gives approximate volumes for partially filled (axis horizontal) standard ASME and ellipsoidal heads. A formula for partially filled heads, by Doolittle [Ind. 

Figure 12.23 Hydropathy plots for the polypeptide chains L and M of the reaction center of Rhodobacter sphaeroides. A window of 19 amino acids was used with the hydrophohicity scales of Kyte and Doolittle. The hydropathy index is plotted against the tenth amino acid of the window. The positions of the transmembrane helices as found by subsequent x-ray analysis by the group of G. Feher, La Jolla, California, ate indicated by the green regions.

Kyte, J., Doolittle, R.F. A simple method for displaying the hydropathic character of a protein. /. Mol. Biol. 

L. L. Blyler and T. K. Kwei [39] proposed the direct opposite (to 4). In their reasoning, they proceeded from the known and generally acceptable Doolittle equation, which puts liquid viscosity in exponential dependence on the inverse value of the free volume of the latter. According to [39], gas has a volume of its own, the value of which it contributes to the free volume of the polymer when it dissolves therein as a result, viscosity falls. The theoretical formula obtained by the authors was experimentally confirmed in the same work. The authors measured pressure values at the entrance of cylindrical capillaries, through which melts of both pure polyethylene, and polyethylene with gas dissolved in it, extruded at a constant rate. 

According to free-volume interpretations, the rate of molecular motions is governed entirely by the available unoccupied space ( free volume ). Early studies of molecular liquids led to the Doolittle equation, relating the viscosity to the fractional free volume, / [23,24]... 

Mouse (hepatocyte unscheduled DNA synthesis) DNA damage (unspecified) - Doolittle etal. 1987... 

Doolittle DJ, Muller G, Scribner HE. 1987. The in vivo-in vitro hepatocyte assay for assessing DNA repair and DNA replication Studies in the CD-I mouse. Food Chem Toxicol 25 399-405. 

Information about the putative folding of the H,K-ATPase catalytic subunit through the membrane has been obtained by the combined use of hydropathy analysis according to the criteria of Kyte and Doolittle [51], identification of sites sensitive to chemical modification [46,48,50,52-55], and localization of epitopes of monoclonal antibodies [56]. The model of the H,K-ATPase catalytic subunit (Fig. 1) which has emerged from these studies shows ten transmembrane segments and contains cytosolic N- and C-termini [53]. This secondary structure of the catalytic subunit is probably a common feature of the catalytic subunits of P-type ATPases, since evidence supporting a ten a-helical model with cytosolic N- and C-termini has also been published recently for both Ca-ATPase of the sarcoplasmic reticulum and Na,K-ATPase [57-59]. 

Schultz, Steven Paul. "The imagination of H. D. Hilda Doolittle and Hermetic definition." State Univ New York, 1983. 

Uversky and co-workers recently used a pair of sequence attributes, specifically the Kyte-Doolittle hydropathy scale and net charge, to... 

Loutfy and coworkers [29, 30] assumed a different mechanism of interaction between the molecular rotor molecule and the surrounding solvent. The basic assumption was a proportionality of the diffusion constant D of the rotor in a solvent and the rotational reorientation rate kOI. Deviations from the Debye-Stokes-Einstein hydrodynamic model were observed, and Loutfy and Arnold [29] found that the reorientation rate followed a behavior analogous to the Gierer-Wirtz model [31]. The Gierer-Wirtz model considers molecular free volume and leads to a power-law relationship between the reorientation rate and viscosity. The molecular free volume can be envisioned as the void space between the packed solvent molecules, and Doolittle found an empirical relationship between free volume and viscosity [32] (6),... 

Doolittle AK (1952) Studies in Newtonian flow III. The dependence of the viscosity of liquids on molecule weight and free space (in homologous series). J Appl Phys 23(2) 236-239... 

In the case of eukaryotes, LGT accounts for the movement of genes (P elements) between Drosophila species via a mite intermediate (Charlesworth and Langley, 1991 Houck etal., 1991 Cummings, 1994 Syvanen, 1994). This is not to say that LGT has replaced gene movement by well known vertical paths (sexual reproduction). Indeed, Doolittle (1999, p. 2127) warns ... 

An initial suggestion made by Ford Doolittle shows a jumble of interconnections between the lines of development, rather than simple branches in the phylogenetic tree. These interconnections resemble a mycelium and have almost nothing in common with the original model, except for the termini of the three kingdoms. In a review article in Science, Elizabeth Pennisi (2001) chose the colourful metaphor of a tangled bramble bush to describe the new model. 

Fig. 10.11 The modified tree of life still has the usual tree-like structure and also confirms that the eukaryotes originally took over mitochondria and chloroplasts from bacteria. It does, however, also show a network of links between the branches. The many interconnections indicate a frequent transfer of genes between unicellular organisms. The modified tree of life is not derived, as had previously been assumed, from a single cell (the hypothetical primeval cell ). Instead, the three main kingdoms are more likely to have developed from a community of primitive cells with different genomes (Doolittle, 2000)...

There are a number of other possibilities for the explanation of the Doolittle event (Mooers and Redfield, 1996). One of these could be due to the analytical method used by Doolittle, as he assumed a relatively constant rate of amino acid substitution. This assumption may not be justified and should be checked. 

It is not only the vast difference of about 1.8 billion years which is so surprising the timescale for the separation point of the main branches of the tree of life is clearly shifted. The catastrophe hypothesis put forward to explain this difference appears unlikely, since there are no signs of such a phenomenal obliteration of all life on Earth. Another explanation could be that the data from the amino acid sequences provide only information on the way in which life forms diverged, but not on the timescale (Schopf, 1998). This interpretation of the Doolittle event by Schopf was provided at a time when doubts had not yet been cast on the dating of the first fossils at 3.45 billion years, published by him in 1993. 

If, in the near future, results were to appear which show that the first traces of life are not in fact 3.45 billion years old, the Doolittle event would return to the discussion and become more probable than it is at present. Thus, the tree of life is still decorated with many questions, which will hopefully decrease, and finally disappear, in the next few years. 

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