10,691 research outputs found

    At Home Abroad: The Field Site as a Second Home.

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    "Encystation": Containment and Control in Israeli Ideology and Practice

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    The radical closure of Gaza serves here as an extreme example of a process of isolation and immiseration of national enemies that is deeply rooted in Israeli ideology and practices of state formation. I use encystation to reveal the dual meaning of the term—that of radical isolation of diseased elements and that of protecting a fetus within a womb—and to show how the two meanings connect with respective Israeli policies toward Palestinians and Jews. I suggest in closing that the Oslo Accords have put in place mechanisms for the future imposition on West Bank Palestinians of the same containment currently afflicting Gaz

    rpanel: Simple Interactive Controls for R Functions Using the tcltk Package

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    In a variety of settings it is extremely helpful to be able to apply R functions through buttons, sliders and other types of graphical control. This is particularly true in plotting activities where immediate communication between such controls and a graphical display allows the user to interact with a plot in a very effective manner. The tcltk package provides extensive tools for this and the aim of the rpanel package is to provide simple and well documented functions which make these facilities as accessible as possible. In addition, the operations which form the basis of communication within tcltk are managed in a way which allows users to write functions with a more standard form of parameter passing. This paper describes the basic design of the software and illustrates it on a variety of examples of interactive control of graphics. The tkrplot system is used to allow plots to be integrated with controls into a single panel. An example of the use of a graphical image, and the ability to interact with this, is also discussed.

    Chemistry: Space resources for teachers including suggestions for classroom activities and laboratory experiments

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    Curriculum supplement to assist general chemistry teachers in updating instruction materials with aerospace development

    Consistency of parity-violating pion-nucleon couplings extracted from measurements in 18F and 133Cs

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    The recent measurement of the nuclear anapole moment of 133Cs has been interpreted to yield a value of the weak pion-nucleon coupling H_pi^1 which contradicts the upper limit from the 18F experiments. We argue that because of the sensitivity of the anapole moment to H_rho^0 in the odd proton nucleus 133Cs, there is a combination of weak meson-nucleon couplings which satisfies both experiments and which is (barely) in agreement with theory. In addition, the anapole moment measurement in 205Tl gives a constraint which is inconsistent with the value from 133Cs, calling into question the theory of nuclear anapole moments. We argue that measurements of directional asymmetry in n+p-->d+gamma and in the photo-disintegration of the deuteron by circularly polarized photons, combined with results from pp scattering, would determine H_pi^1 and several other weak meson-nucleon couplings in a model-independent way.Comment: 9 pages, RevTeX, 1 figure, eps, submitted to Phys. Rev.

    Improved transmittance measurement with a magnesium oxide coated integrating sphere

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    Simple and convenient technique has been found for extending transmittance measurement capability of conventional magnesium oxide coated integrating sphere system at low (near ultraviolet) wavelengths. Technique can be used to determine effect of contaminants on window materials and can also be used for measurements on thermal control coatings and telescope mirrors

    Alkane hydroxylase genes in psychrophile genomes and the potential for cold active catalysis.

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    BackgroundPsychrophiles are presumed to play a large role in the catabolism of alkanes and other components of crude oil in natural low temperature environments. In this study we analyzed the functional diversity of genes for alkane hydroxylases, the enzymes responsible for converting alkanes to more labile alcohols, as found in the genomes of nineteen psychrophiles for which alkane degradation has not been reported. To identify possible mechanisms of low temperature optimization we compared putative alkane hydroxylases from these psychrophiles with homologues from nineteen taxonomically related mesophilic strains.ResultsSeven of the analyzed psychrophile genomes contained a total of 27 candidate alkane hydroxylase genes, only two of which are currently annotated as alkane hydroxylase. These candidates were mostly related to the AlkB and cytochrome p450 alkane hydroxylases, but several homologues of the LadA and AlmA enzymes, significant for their ability to degrade long-chain alkanes, were also detected. These putative alkane hydroxylases showed significant differences in primary structure from their mesophile homologues, with preferences for specific amino acids and increased flexibility on loops, bends, and α-helices.ConclusionA focused analysis on psychrophile genomes led to discovery of numerous candidate alkane hydroxylase genes not currently annotated as alkane hydroxylase. Gene products show signs of optimization to low temperature, including regions of increased flexibility and amino acid preferences typical of psychrophilic proteins. These findings are consistent with observations of microbial degradation of crude oil in cold environments and identify proteins that can be targeted in rate studies and in the design of molecular tools for low temperature bioremediation
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