864 research outputs found

    Monte Carlo Simulation of 2-D Quantum Gravity as Open Dynamically Triangulate Random Surfaces

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    We describe a Monte Carlo procedure for the simulation of dynamically triangulate random surfaces with a boundary (topology of a disk). The algorithm keeps the total number of triangles fixed, while the length of the boundary is allowed to fluctuate. The algorithm works in the presence of matter fields. We here present results for the pure gravity case. The algorithm reproduces the theoretical expectations.Comment: LaTeX file, 16 pages, 7 LaTeX figures, preprints CERN-TH.7028/93, MS-TPI-93-0

    Quo vadis radiotherapy? Technological advances and the rising problems in cancer management

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    Extent: 10p.Purpose. Despite the latest technological advances in radiotherapy, cancer control is still challenging for several tumour sites. The survival rates for the most deadly cancers, such as ovarian and pancreatic, have not changed over the last decades. The solution to the problem lies in the change of focus: from local treatment to systemic therapy. The aim of this paper is to present the current status as well as the gaps in radiotherapy and, at the same time, to look into potential solutions to improve cancer control and survival. Methods. The currently available advanced radiotherapy treatment techniques have been analysed and their cost-effectiveness discussed. The problem of systemic disease management was specifically targeted. Results. Clinical studies show limited benefit in cancer control from hadron therapy. However, targeted therapies together with molecular imaging could improve treatment outcome for several tumour sites while controlling the systemic disease. Conclusion. The advances in photon therapy continue to be competitive with the much more expensive hadron therapy. To justify the cost effectiveness of proton/heavy ion therapy, there is a need for phase III randomised clinical trials. Furthermore, the success of systemic disease management lies in the fusion between radiation oncology technology and microbiology.Barry J. Allen, Eva Bezak, and Loredana G. Marc

    Investigation of the Critical Behavior of the Critical Point of the Z2 Gauge Lattice

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    We investigate, through Monte-Carlo simulations, the nature of the second order point in a Z2Z_2 (Bosonic) + Z2Z_2 gauge theory in four dimensions. Detailed analysis of the critical exponents point to the Ising universality class. Relevancy to extended models and possible Non-Gaussian behavior is discussed.Comment: 4 pages, 6 figures, LaTe

    The Influence of Partial and Full Thickness Tears on Infraspinatus Tendon Strain Patterns

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    Tears on the bursal and articular sides of the rotator cuff tendons are known to behave differently and strain is thought to play a role in this difference. This study investigates the effect of tear location on the changes in three strain measurements (grip-to-grip, insertion, and mid-substance tissue) in a sheep infraspinatus tendon model during axial loading. We introduced a 14mm wide defect near the insertion from either the articular or bursal side of the tendon to three depths (3 mm, 7mm & full) progressively. For each condition, tendons were sinusoidally stretched (4% at 0.5 Hz) while insertion and midsubstance strains were tracked with surface markers. For a fixed load, grip-to-grip strain increased significantly compared to intact for both cuts. Insertion strain increased significantly for the bursal-side defect immediately but not for the articular-side until the 66% cut. Mid-substance tissue strain showed no significant change for partial thickness articular-side defects and a significant decrease for bursal-side defects after the 66% cut. All full thickness cuts exhibited negligible mid-substance tissue strain change. Our results suggest that the tendon strain patterns are more sensitive to defects on the bursal side, and that partial thickness tears tend to induce localized strain concentrations in regions adjacent to the damaged tissue

    Uqosp(2,2)U_q osp(2,2) Lattice Models

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    In this paper I construct lattice models with an underlying Uqosp(2,2)U_q osp(2,2) superalgebra symmetry. I find new solutions to the graded Yang-Baxter equation. These {\it trigonometric} RR-matrices depend on {\it three} continuous parameters, the spectral parameter, the deformation parameter qq and the U(1)U(1) parameter, bb, of the superalgebra. It must be emphasized that the parameter qq is generic and the parameter bb does not correspond to the `nilpotency' parameter of \cite{gs}. The rational limits are given; they also depend on the U(1)U(1) parameter and this dependence cannot be rescaled away. I give the Bethe ansatz solution of the lattice models built from some of these RR-matrices, while for other matrices, due to the particular nature of the representation theory of osp(2,2)osp(2,2), I conjecture the result. The parameter bb appears as a continuous generalized spin. Finally I briefly discuss the problem of finding the ground state of these models.Comment: 19 pages, plain LaTeX, no figures. Minor changes (version accepted for publication

    Using Synchronic and Diachronic Relations for Summarizing Multiple Documents Describing Evolving Events

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    In this paper we present a fresh look at the problem of summarizing evolving events from multiple sources. After a discussion concerning the nature of evolving events we introduce a distinction between linearly and non-linearly evolving events. We present then a general methodology for the automatic creation of summaries from evolving events. At its heart lie the notions of Synchronic and Diachronic cross-document Relations (SDRs), whose aim is the identification of similarities and differences between sources, from a synchronical and diachronical perspective. SDRs do not connect documents or textual elements found therein, but structures one might call messages. Applying this methodology will yield a set of messages and relations, SDRs, connecting them, that is a graph which we call grid. We will show how such a grid can be considered as the starting point of a Natural Language Generation System. The methodology is evaluated in two case-studies, one for linearly evolving events (descriptions of football matches) and another one for non-linearly evolving events (terrorist incidents involving hostages). In both cases we evaluate the results produced by our computational systems.Comment: 45 pages, 6 figures. To appear in the Journal of Intelligent Information System

    In Flight miRNA Isolation and Recovery on the ISS

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    Due to advancements in RNA research, mi (micro) RNAs and other small nucleotide RNAs have become a major research field in biology including spaceflight research. The regulation of RNA transcription and processing by miRNAs makes miRNAs an appealing topic for genetics and molecular research. It has been estimated that over 60% of human gene transcripts are targets of miRNA regulation. In fact, this is true for all organisms, including plants and insects. Small nucleotide RNAs can also play a role in regulating gene expression, meaning that gene expression alone is not a complete picture of the potential genetic changes that occur in an organism during spaceflight. The goal of the WetLab-2 project is to isolate and recover miRNAs from various tissue sources on the International Space Station (ISS). No system currently exists that can isolate and recover small nucleotide RNA in space. However, the WetLab-2 system that was validated on the ISS in 2016 can be adapted to fit this purpose. We are currently testing the new modified protocols by running plant and mouse blood experiments in parallel, allowing us to demonstrate the effectiveness of the procedure on different sample types. We expect to be able to optimize and implement the modified miRNA protocols for use on future ISS flights
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