5,527 research outputs found
High Apoptotic Index in Urine Cytology Is Associated with High-Grade Urothelial Carcinoma
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
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
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
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
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
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
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
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
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 . 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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