5,527 research outputs found

    High Apoptotic Index in Urine Cytology Is Associated with High-Grade Urothelial Carcinoma

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    BACKGROUND The significance of apoptosis and its association with high-grade urothelial carcinoma (HGUC) in urine cytology has yet to be determined. METHODS A computerized search of the study laboratory information system was performed over a 3-year period for all urine cytology specimens processed using the SurePath liquid-based preparation technique. Only those cases with correlating surgical pathology obtained within 6 months after the urine cytologic samples were included in the current study. Cases from ileal conduit samples were excluded. A semiquantitative numerical scoring system (apoptotic index) was used to assess the amount of pyknosis or karyorrhexis, with 0 indicating none, 1 indicating  30 per 10 high-power fields. Statistical analysis using the Pearson chi-square test was performed. RESULTS A total of 228 cases including 105 benign cases, 79 cases of HGUC, and 44 cases of low-grade urothelial carcinoma (LGUC) diagnosed on follow-up surgical pathology were selected. A score of 0 was observed in 70 benign, 11 HGUC, and 8 LGUC cases; a score of 1 was observed in 31 benign, 21 HGUC, and 23 LGUC cases; a score of 2 was observed in 3 benign, 27 HGUC, and 9 LGUC cases; and a score of 3 was observed in 1 benign, 20 HGUC, and 4 LGUC cases. CONCLUSIONS Excluding ileal conduit urine specimens, the finding of a high apoptotic index (score ≥ 2) with the presence of pyknosis or karyorrhexis in ≥10 per 10 high-power fields in the urine cytology appears to be significantly associated with HGUC (P<.05)

    Highly accelerated simulations of glassy dynamics using GPUs: caveats on limited floating-point precision

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    Modern graphics processing units (GPUs) provide impressive computing resources, which can be accessed conveniently through the CUDA programming interface. We describe how GPUs can be used to considerably speed up molecular dynamics (MD) simulations for system sizes ranging up to about 1 million particles. Particular emphasis is put on the numerical long-time stability in terms of energy and momentum conservation, and caveats on limited floating-point precision are issued. Strict energy conservation over 10^8 MD steps is obtained by double-single emulation of the floating-point arithmetic in accuracy-critical parts of the algorithm. For the slow dynamics of a supercooled binary Lennard-Jones mixture, we demonstrate that the use of single-floating point precision may result in quantitatively and even physically wrong results. For simulations of a Lennard-Jones fluid, the described implementation shows speedup factors of up to 80 compared to a serial implementation for the CPU, and a single GPU was found to compare with a parallelised MD simulation using 64 distributed cores.Comment: 12 pages, 7 figures, to appear in Comp. Phys. Comm., HALMD package licensed under the GPL, see http://research.colberg.org/projects/halm

    A Daoist perspective on leadership: reputation-building in Chinese SMEs

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    This is the author accepted manuscript. The final version is available from Emerald via the DOI in this recordPurpose This article examines the influence of Daoist nothingness on leadership in growing Chinese SMEs. Daoism is based on a ‘letting-go’ approach through maintaining inherent openness, which challenges goal-oriented and hierarchical approaches typical of Western and Confucian leadership theories. This facilitates the cross-fertilization of ideas related to the effective management of smaller firms. Design/methodology/approach This study focuses on SME leaders in a group of twelve growing SMEs in the Shanghai logistics industry in China. Narrative and semi-structured interviews explored emerging aspects beyond the established model of leadership associated with reputation-building. This led to in-depth, thick descriptions, broadening our understanding of leadership and reputation building. Findings SME leaders follow nothingness by continuously adopting a letting-go approach which spontaneously fosters reputation-building. By maintaining inherent openness, nothingness functions as an enabling principle that mobilises multi-beings leading to reputation-building in unintended ways. Research limitations/implications A greater plurality of empirical and methodological contexts in Western and non-Western countries helps to understand the dynamics and intersection of Daoist nothingness, leadership and reputation-building. Practical implications SME leaders recounted how they discursively practised nothingness for extended periods in their everyday practice. The study shows the significance of nothingness for SME leaders who aspire to grow their businesses by reputation-building among salient stakeholders. Social implications Daoist nothingness provides insights into the distinctive approach of Chinese SME leaders and their relationships with local and distant stakeholders. By engaging in active non-action they relax pre-determined intentions and immerse themselves in the process of leading, where the intrinsic connections between goals and processes are automatically animated. Such an approach differs from the top-down and goal-oriented approach to leadership adopted in many western SMEs. Originality/value This paper makes two theoretical contributions. First, it indicates the powerful influence of Daoist nothingness on leadership by drawing on the broader context of entrepreneurship in Chinese SMEs. Second, it enriches existing concepts such as reputation by endowment and reputation borrowing by demonstrating how Daoist nothingness silently fosters both local reputation and generalized reputation

    Exact noncommutative solitons in p-adic strings and BSFT

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    The tachyon field of p-adic string theory is made noncommutative by replacing ordinary products with noncommutative products in its exact effective action. The same is done for the boundary string field theory, treated as the p -> 1 limit of the p-adic string. Solitonic lumps corresponding to D-branes are obtained for all values of the noncommutative parameter theta. This is in contrast to usual scalar field theories in which the noncommutative solitons do not persist below a critical value of theta. As theta varies from zero to infinity, the solution interpolates smoothly between the soliton of the p-adic theory (respectively BSFT) to the noncommutative soliton.Comment: 1+14 pages (harvmac b), 1 eps figure, v2: references added, typos correcte

    On fluctuations of closed string tachyon solitons

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    We discuss fluctuations on solitons in the dilaton/graviton/tachyon system using the low energy effective field theory approach. It is shown that closed string solitons are free of tachyons in this approximation, regardless of the exact shape of the tachyon potential.Comment: 13 pages, 1 figure, uses JHEP3.cl

    Adaptive Evolutionary Clustering

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    In many practical applications of clustering, the objects to be clustered evolve over time, and a clustering result is desired at each time step. In such applications, evolutionary clustering typically outperforms traditional static clustering by producing clustering results that reflect long-term trends while being robust to short-term variations. Several evolutionary clustering algorithms have recently been proposed, often by adding a temporal smoothness penalty to the cost function of a static clustering method. In this paper, we introduce a different approach to evolutionary clustering by accurately tracking the time-varying proximities between objects followed by static clustering. We present an evolutionary clustering framework that adaptively estimates the optimal smoothing parameter using shrinkage estimation, a statistical approach that improves a naive estimate using additional information. The proposed framework can be used to extend a variety of static clustering algorithms, including hierarchical, k-means, and spectral clustering, into evolutionary clustering algorithms. Experiments on synthetic and real data sets indicate that the proposed framework outperforms static clustering and existing evolutionary clustering algorithms in many scenarios.Comment: To appear in Data Mining and Knowledge Discovery, MATLAB toolbox available at http://tbayes.eecs.umich.edu/xukevin/affec

    Closed string tachyons, flips and conifolds

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    Following the analysis of tachyons and orbifold flips described in hep-th/0412337, we study nonsupersymmetric analogs of the supersymmetric conifold singularity and show using their toric geometry description that they are nonsupersymmetric orbifolds of the latter. Using linear sigma models, we see that these are unstable to localized closed string tachyon condensation and exhibit flip transitions between their two small resolutions (involving 2-cycles), in the process mediating mild dynamical topology change. Our analysis shows that the structure of these nonsupersymmetric conifolds as quotients of the supersymmetric conifold obstructs the 3-cycle deformation of such singularities, suggesting that these nonsupersymmetric conifolds decay by evolving towards their stable small resolutions.Comment: Latex, 22 pgs, 2 figs. v4: matches JHEP version, 29 pgs, 3 figures, more elaborate Introduction, various clarifications adde

    Refractive Index of Humid Air in the Infrared: Model Fits

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    The theory of summation of electromagnetic line transitions is used to tabulate the Taylor expansion of the refractive index of humid air over the basic independent parameters (temperature, pressure, humidity, wavelength) in five separate infrared regions from the H to the Q band at a fixed percentage of Carbon Dioxide. These are least-squares fits to raw, highly resolved spectra for a set of temperatures from 10 to 25 C, a set of pressures from 500 to 1023 hPa, and a set of relative humidities from 5 to 60%. These choices reflect the prospective application to characterize ambient air at mountain altitudes of astronomical telescopes.Comment: Corrected exponents of c0ref, c1ref and c1p in Table

    Random walks and the Hagedorn transition

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    We study details of the approach to the Hagedorn temperature in string theory in various static spacetime backgrounds. We show that the partition function for a {\it single} string at finite temperature is the torus amplitude restricted to unit winding around Euclidean time. We use the worldsheet path integral to derive the statement that the the sum over random walks of the thermal scalar near the Hagedorn transition is precisely the image under a modular transformation of the sum over spatial configurations of a single highly excited string. We compute the radius of gyration of thermally excited strings in AdSD×SnAdS_D\times S^n. We show that the winding mode indicates an instability despite the AdS curvature at large radius, and that the negative mass squared decreases with decreasing AdS radius, much like the type 0 tachyon. We add further arguments to statements by Barbon and Rabinovici, and by Adams {\it et. al.}, that the Euclidean AdS black hole can thought of as a condensate of the thermal scalar. We use this to provide circumstantial evidence that the condensation of the thermal scalar decouples closed string modes.Comment: 34 pages (7 of references), 5 figures. v2: Reference added, grant acknowledgement added, typos correcte
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