2,295 research outputs found

    Reversible implementation of a disrete linear transformation

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    Discrete linear transformations form important steps in processing information. Many such transformations are injective and therefore are prime candidates for a physically reversible implementation into hardware. We present here the first steps towards a reversible digital implementation of two different integer transformations on four inputs: The Haar wavelet and the H.264 transform

    Undergraduate marketing education in the UK

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    This paper summarises and reflects upon a project which was supported by a small grant from the Academy of Marketing Teaching Research and Development award scheme in 2012/2013. The project collected and mixed together publicly available data on marketing education currently provided by HEIs with more detailed and specific information received directly from individual institutions. It did this in order to provide a clear strategic overview of HE marketing and related subject programmes in the UK – numbers, structure, coverage, curriculum design, aims and objectives. 108 UK HEIs were surveyed. As a result of this, a database on current provision has been created to be shared with colleagues and a number of more specific projects are underway that it is hoped will fully exploit the data to the benefit of the Academy

    Insights on the adsorption behavior of aromatics in MIL-47 and MIL-53 from a theoretical perspective

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    Recently, the spectrum of nanoporous materials like zeolites and zeotype structures has been further expanded through the discovery of a new class of hybrid porous solids [1, 2]. Those materials, nowadays also known as metal organic frameworks or MOFs, consist of both inorganic and organic moieties. Certain MOFs exhibit a very interesting adsorption and even catalytic behavior. Within this contribution, we will mainly focus on adsorption and separation of aromatic species in MIL-47 and MIL-53 [3, 4, 5]. Some of the presenting authors reported for first time on the successful use of MOFs as selective adsorbents for the extremely difficult and industrially relevant separations of para-xylene versus meta-xylene and para-xylene versus ethylbenzene [3]. Their study focuses on the MIL-47, which was first synthesized by Barthelet [4]. This separation behavior of MIL-47 could be better understood with adsorption studies [3, 5]. The packing of each C8-pair will be discussed on the basis of the interactions between those two aromatic compounds and MIL-47 [3]. In order to unravel the interaction between the guest molecules and the lattice, periodic Density Functional Theory calculations have been conducted. The DFT calculations were corrected for dispersion interaction [6] to include the long-range attractive forces. It seems that pi-pi stacking energies between pairs of aromatics but also with the walls of the MOF are crucial for the packing behavior in the pores

    Contribution of Amino Acid Region 659−663 of Factor Va Heavy Chain to the Activity of Factor Xa within Prothrombinase†,‡

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    ABSTRACT: Factor Va, the cofactor of prothrombinase, is composed of heavy and light chains associated noncovalently in the presence of divalent metal ions. The COOH-terminal region of the heavy chain contains acidic amino acid clusters that are important for cofactor activity. In this work, we have investigated the role of amino acid region 659-663, which contains five consecutive acidic amino acid residues, by site-directed mutagenesis. We have generated factor V molecules in which all residues were mutated to either lysine (factor V 5K) or alanine (factor V 5A). We have also constructed a mutant molecule with this region deleted (factor V Δ659-663). The recombinant molecules along with wild-type factor V (factor V WT) were transiently expressed in mammalian cells, purified, and assessed for cofactor activity. Two-stage clotting assays revealed that the mutant molecules had reduced clotting activities compared to that of factor Va WT. Kinetic analyses of prothrombinase assembled with the mutant molecules demonstrated diminished k cat values, while the affinity of all mutant molecules for factor Xa was similar to that for factor Va WT. Gel electrophoresis analyses of plasma-derived and recombinant mutant prothrombin activation demonstrated delayed cleavage of prothrombin at both Arg 320 and Arg 271 by prothrombinase assembled with the mutant molecules, resulting i

    The Walkback Test: A Study to Evaluate Suit and Life Support System Performance Requirements for a 10 Kilometer Traverse in a Planetary Suit

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    As planetary suit and planetary life support systems develop, specific design inputs for each system relate to a presently unanswered question concerning operational concepts: What distance can be considered a safe walking distance for a suited EVA crew member exploring the surface of the Moon to "walk-back" to the habitat in the event of a rover breakdown, taking into consideration the planned EVA tasks as well as the possible traverse back to the habitat? It has been assumed, based on Apollo program experience, that 10 kilometers (6.2 mi) will be the maximum EVA excursion distance from the lander or habitat to ensure the crew member s safe return to the habitat in the event of a rover failure. To investigate the feasibility of performing a suited 10 km Walkback, NASA-JSC assembled a multi-disciplinary team to design and implement the Lunar Walkback Test . The test was designed not only to determine the feasibility of a 10 km excursion, but also to collect human performance, biomedical, and biomechanical data relevant to optimizing space suit design and life support system sizing. These data will also be used to develop follow-on studies to understand interrelationships of such key parameters as suit mass, inertia, suit pressure, and center of gravity (CG), and the respective influences of each on human performance

    Integrated Suit Test 1 - A Study to Evaluate Effects of Suit Weight, Pressure, and Kinematics on Human Performance during Lunar Ambulation

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    In an effort to design the next generation Lunar suit, NASA has initiated a series of tests aimed at understanding the human physiological and biomechanical affects of space suits under a variety of conditions. The first of these tests was the EVA Walkback Test (ICES 2007-01-3133). NASA-JSC assembled a multi-disciplinary team to conduct the second test of the series, titled Integrated Suit Test 1 (IST-1), from March 6 through July 24, 2007. Similar to the Walkback Test, this study was performed with the Mark III (MKIII) EVA Technology Demonstrator suit, a treadmill, and the Partial Gravity Simulator in the Space Vehicle Mock-Up Facility at Johnson Space Center. The data collected for IST-1 included metabolic rates, ground reaction forces, biomechanics, and subjective workload and controllability feedback on both suited and unsuited (shirt-sleeve) astronaut subjects. For IST-1 the center of gravity was controlled to a nearly perfect position while the weight, pressure and biomechanics (waist locked vs. unlocked) were varied individually to evaluate the effects of each on the ability to perform level (0 degree incline) ambulation in simulated Lunar gravity. The detailed test methodology and preliminary key findings of IST-1 are summarized in this report

    Pathways of change : shifting connectivities in the world city network, 2000-08

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    This is an empirical paper that measures and interprets changes in intercity relations at the global scale in the period 2000-08. It draws on the network model devised by the Globalization and World Cities (GaWC) research group to measure global connectivities for 132 cities across the world in 2000 and 2008. The measurements for both years are adjusted so that a coherent set of services/cities is used. A range of statistical techniques is used to explore these changes at the city level and the regional scale. The most notable changes are: the general rise of connectivity in the world city network; the loss of global connectivity of US and sub-Saharan African cities (Los Angeles, San Francisco and Miami in particular); and, the gain in global connectivity of south Asian, Chinese and eastern European cities (Shanghai, Beijing and Moscow in particular)
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