1,244 research outputs found

    Crystallization and Preliminary Analysis of Crystals of the 24-Meric Hemocyanin of the Emperor Scorpion (Pandinus imperator)

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    Hemocyanins are giant oxygen transport proteins found in the hemolymph of several invertebrate phyla. They constitute giant multimeric molecules whose size range up to that of cell organelles such as ribosomes or even small viruses. Oxygen is reversibly bound by hemocyanins at binuclear copper centers. Subunit interactions within the multisubunit hemocyanin complex lead to diverse allosteric effects such as the highest cooperativity for oxygen binding found in nature. Crystal structures of a native hemocyanin oligomer larger than a hexameric substructure have not been published until now. We report for the first time growth and preliminary analysis of crystals of the 24-meric hemocyanin (MW = 1.8 MDa) of emperor scorpion (Pandinus imperator), which diffract to a resolution of 6.5 Å. The crystals are monoclinc with space group C 1 2 1 and cell dimensions a = 311.61 Å, b = 246.58 Å and c = 251.10 Å (α = 90.00°, β = 90.02°, γ = 90.00°). The asymmetric unit contains one molecule of the 24-meric hemocyanin and the solvent content of the crystals is 56%. A preliminary analysis of the hemocyanin structure reveals that emperor scorpion hemocyanin crystallizes in the same oxygenated conformation, which is also present in solution as previously shown by cryo-EM reconstruction and small angle x-ray scattering experiments

    Bias in the journal impact factor

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    The ISI journal impact factor (JIF) is based on a sample that may represent half the whole-of-life citations to some journals, but a small fraction (<10%) of the citations accruing to other journals. This disproportionate sampling means that the JIF provides a misleading indication of the true impact of journals, biased in favour of journals that have a rapid rather than a prolonged impact. Many journals exhibit a consistent pattern of citation accrual from year to year, so it may be possible to adjust the JIF to provide a more reliable indication of a journal's impact.Comment: 9 pages, 8 figures; one reference correcte

    The Monte Carlo Program KoralW version 1.51 and The Concurrent Monte Carlo KoralW&YFSWW3 with All Background Graphs and First Order Corrections to W-Pair Production

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    The version 1.51 of the Monte Carlo (MC) program KoralW for all e+e−→f1fˉ2f3fˉ4e^+e^-\to f_1\bar f_2 f_3\bar f_4 processes is presented. The most important change since the previous version 1.42 is the facility for writing MC events on the mass storage device and re-processing them later on. In the re-processing one may modify parameters of the Standard Model in order to fit them to experimental data. Another important new feature is a possibility of including complete O(α){\cal O}(\alpha) corrections to double-resonant W-pair component-processes in addition to all background (non-WW) graphs. The inclusion is done with the help of the YFSWW3 MC event generator for fully exclusive differential distributions (event-per-event). Technically, it is done in such a way that YFSWW3 runs concurrently with KoralW as a separate slave process, reading momenta of the MC event generated by KoralW and returning the correction weight to KoralW. KoralW introduces the O(α){\cal O}(\alpha) correction using this weight, and finishes processing the event (rejection due to total MC weight, hadronization, etc.). The communication between KoralW and YFSWW3 is done with the help of the FIFO facility of the UNIX/Linux operating system. This does not require any modifications of the FORTRAN source codes. The resulting Concurrent MC event generator KoralW&YFSWW3 looks from the user's point of view as a regular single MC event generator with all the standard features.Comment: 8 figures, 5 tables, submitted to Comput. Phys. Commu

    RALph: A Graphical Notation for Resource Assignments in Business Processes

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    The business process (BP) resource perspective deals with the management of human as well as non-human resources throughout the process lifecycle. Although it has received increasing attention recently, there exists no graphical notation for it up until now that is both expressive enough to cover well-known resource selection conditions and independent of the BP modelling language. In this paper, we introduce RALph, a graphical notation for the assignment of human resources to BP activities. We define its semantics by mapping this notation to a language that has been formally defined in description logics, which enables its automated analysis. Although we show how RALph can be seamlessly integrated with BPMN, it is noteworthy that the notation is independent of the BP modelling language. Altogether, RALph will foster the visual modelling of the resource perspective in BP

    Lyapunov spectral analysis of a nonequilibrium Ising-like transition

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    By simulating a nonequilibrium coupled map lattice that undergoes an Ising-like phase transition, we show that the Lyapunov spectrum and related dynamical quantities such as the dimension correlation length~ξδ\xi_\delta are insensitive to the onset of long-range ferromagnetic order. As a function of lattice coupling constant~gg and for certain lattice maps, the Lyapunov dimension density and other dynamical order parameters go through a minimum. The occurrence of this minimum as a function of~gg depends on the number of nearest neighbors of a lattice point but not on the lattice symmetry, on the lattice dimensionality or on the position of the Ising-like transition. In one-space dimension, the spatial correlation length associated with magnitude fluctuations and the length~ξδ\xi_\delta are approximately equal, with both varying linearly with the radius of the lattice coupling.Comment: 29 pages of text plus 15 figures, uses REVTeX macros. Submitted to Phys. Rev. E

    The Monte Carlo Event Generator YFSWW3 version 1.16 for W-Pair Production and Decay at LEP2/LC Energies

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    We present the Monte Carlo event generator YFSWW3 version 1.16 for theprocess of W-pair production and decay in electron-positron collisions. It includes O(α){\cal O}(\alpha) electroweak radiative corrections in the WW production stage together with the O(α3){\cal O}(\alpha^3) initial-state-radiation (ISR) corrections in the leading-logarithmic (LL) approximation, implemented within the Yennie-Frautschi-Suura (YFS) exclusive exponentiation framework. The photon radiation in the W decays is generated by the dedicated program PHOTOS up to O(α2){\cal O}(\alpha^2) LL, normalised to the W branching ratios. The program is interfaced with the τ\tau decay library TAUOLA and the quark fragmentation/hadronization package JETSET. The semi-analytical code KORWAN for the calculations of the differential and total cross-sections at the Born level and in the ISR approximation is included.Comment: submitted to Comput. Physics Commu

    Detecting the Effects of Changes on the Compliance of Cross-organizational Business Processes

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    An emerging challenge for collaborating business partners is to properly define and evolve their cross-organizational processes with respect to imposed global compliance rules. Since compliance verification is known to be very costly, reducing the number of compliance rules to be rechecked in the context of process changes will be crucial. Opposed to intra-organizational processes, however, change effects cannot be easily assessed in such distributed scenarios, where partners only provide restricted public views and assertions on their private processes. Even if local process changes are invisible to partners, they might affect the compliance of the cross-organizational process with the mentioned rules. This paper provides an approach for ensuring compliance when evolving a cross-organizational process. For this purpose, we construct qualified dependency graphs expressing relationships between process activities, process assertions, and compliance rules. Based on such graphs, we are able to determine the subset of compliance rules that might be affected by a particular change. Altogether, our approach increases the efficiency of compliance checking in cross-organizational settings

    Complete analysis on the next-to-leading order supersymmetric QCD corrections to B0−Bˉ0B^0-\bar{B}^0 mixing

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    We present a complete next-to-leading-order calculation of the QCD corrections to B0−Bˉ0B^0-\bar{B}^0 (K0−Kˉ0K^0-\bar{K}^0) mixing in the framework of the minimal flavor violating (MFV) supersymmetry. We take into account the contributions from the gluino and find that the gluino-mediated corrections modify the LO result obviously even when the mass of gluino mg~≫mwm_{\tilde{g}} \gg m_{\rm w}. In general, one cannot neglect gluino contributions.Comment: 91 pages + 11 eps figures, publication version in PR
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