1,205 research outputs found
Monte Carlo Simulation of 2-D Quantum Gravity as Open Dynamically Triangulate Random Surfaces
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
Positive surgical margins in nephron-sparing surgery; the great unknown
There is a currently a general trend towards organ-preserving surgery, and urology is no exception. Specifically, nephron-sparing surgery (NSS) has gained general acceptance for T1a renal cell carcinoma (guidelines recommendations). Moreover T1b, T2 and even T3 stage tumors have been included on the nephron sparing list at some centers. An unresolved issue is that of positive surgical margins (PSM), not only their detection but also the implications for follow up and treatment. This paper highlights data available on risk factors for PSM, their clinical relevance, and possible therapeutic consequences.
From the surgeon’s viewpoint, NSS is a daring and risky surgical procedure. Urological guidelines stress the importance of NSS, and thus the trend is moving in that direction. Unresolved, however, is the problem of PSM. Trifecta, MIC, and pentafecta are applicable concepts which attempt to define the optimal endpoint of NSS, but further elaboration is necessary. Specifically, research needs to focus less on the concept of definitive margins and more on their identification and avoidance. Although some studies suggest that PSMs do not influence overall survival rate, the basic idea of preserving tissue that is not cancerous leads to further medical, social, and psychological considerations
Thermal Benchmark and Power Benchmark Software
Power consumption and heat dissipation become key elements in the field of
high-end integrated circuits, especially those used in mobile and high-speed
applications, due to their increase of transistor count and clock frequencies.
Dynamic thermal management strategies have been proposed and implemented in
order to mitigate heat dissipation. However, there is a lack of a tool that can
be used to evaluate DTM strategies and thermal response of real life systems.
Therefore, in this paper we introduce and define the concepts of thermal
benchmark software and power benchmark software as a software application for
run-time system level thermal and power characterizationComment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
4U 1626-67 as seen by Suzaku before and after the 2008 torque reversal
Aims. The accretion-powered pulsar 4U 1626-67 experienced a new torque
reversal at the beginning of 2008, after about 18 years of steadily spinning
down. The main goal of the present work is to study this recent torque reversal
that occurred in 2008 February.
Methods. We present a spectral analysis of this source using two pointed
observations performed by Suzaku in 2006 March and in 2010 September.
Results. We confirm with Suzaku the presence of a strong emission-line
complex centered on 1 keV, with the strongest line being the hydrogen-like Ne
Ly-alpha at 1.025(3) keV. We were able to resolve this complex with up to seven
emission lines. A dramatic increase of the intensity of the Ne Ly-alpha line
after the 2008 torque reversal occurred, with the equivalent width of this line
reaching almost the same value measured by ASCA in 1993. We also report on the
detection of a cyclotron line feature centered at ~37 keV. In spite of the fact
that an increase of the X-ray luminosity (0.5-100 keV) of a factor of ~2.8
occurred between these two observations, no significant change in the energy of
the cyclotron line feature was observed. However, the intensity of the ~1 keV
line complex increased by an overall factor of ~8.
Conclusions. Our results favor a scenario in which the neutron star in 4U
1626-67 accretes material from a geometrically thin disk during both the
spin-up and spin-down phases.Comment: 7 pages, 5 figures and 2 tables. Accepted in A&
Lattice Models
In this paper I construct lattice models with an underlying
superalgebra symmetry. I find new solutions to the graded Yang-Baxter equation.
These {\it trigonometric} -matrices depend on {\it three} continuous
parameters, the spectral parameter, the deformation parameter and the
parameter, , of the superalgebra. It must be emphasized that the
parameter is generic and the parameter does not correspond to the
`nilpotency' parameter of \cite{gs}. The rational limits are given; they also
depend on the parameter and this dependence cannot be rescaled away. I
give the Bethe ansatz solution of the lattice models built from some of these
-matrices, while for other matrices, due to the particular nature of the
representation theory of , I conjecture the result. The parameter
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
Pheochromocytoma – clinical manifestations, diagnosis and current perioperative management
Pheochromocytoma is a neuroendocrine tumor characterized by the excessive production of catecholamines (epinephrine, norepinephrine, and dopamine). The diagnosis is suspected due to hypertensive paroxysms, associated with vegetative phenomena, due to the catecholaminergic hypersecretion. Diagnosis involves biochemical tests that reveal elevated levels of catecholamine metabolites (metanephrine and normetanephrine). Functional imaging, such as 123I-metaiodobenzylguanidine scintigraphy (123I-MIBG), has increased specificity in identifying the catecholamine-producing tumor and its metastases. The gold-standard treatment for patients with pheochromocytoma is represented by the surgical removal of the tumor. Before surgical resection, it is important to optimize blood pressure and intravascular volume in order to avoid negative hemodynamic events
Pelvic floor disorders in gynecological malignancies. An overlooked problem?
Cervical, endometrial, ovarian, vulvar, and vaginal cancers affect women of a broad age spectrum. Many of these women are still sexually active when their cancer is diagnosed. Treatment options for gynecological malignancies, such as gynecological surgery, radiation, and chemotherapy, are proven risk factors for pelvic floor dysfunction. The prevalence of urinary incontinence, fecal incontinence, and sexual dysfunction before cancer treatment is still unclear. Hypotheses have been raised in the literature that these manifestations could represent early symptoms of pelvic cancers, but most remain overlooked even in cancer surviving patients.
The primary focus of therapy is always cancer eradication, but as oncological and surgical treatment options become more successful, the number of cancer survivors increases. The quality of life of patients with gynecological cancers often remains an underrated subject. Pelvic floor disorders are not consistently reported by patients and are frequently overlooked by many clinicians. In this brief review we discuss the importance of pelvic floor dysfunction in patients with gynecological malignant tumors
The Sine Gordon Model: Perturbation Theory and Cluster Monte Carlo
We study the expansion of the surface thickness in the 2-dimensional lattice
Sine Gordon model in powers of the fugacity z. Using the expansion to order
z**2, we derive lines of constant physics in the rough phase. We describe and
test a VMR cluster algorithm for the Monte Carlo simulation of the model. The
algorithm shows nearly no critical slowing down. We apply the algorithm in a
comparison of our perturbative results with Monte Carlo data.Comment: compressed and uuencoded PostScript file, 25 pages, preprints CERN
TH.7374/94, MS-TPI-94-
COMMENTS ABOUT HIGGS FIELDS, NONCOMMUTATIVE GEOMETRY AND THE STANDARD MODEL
We make a short review of the formalism that describes Higgs and Yang Mills
fields as two particular cases of an appropriate generalization of the notion
of connection. We also comment about the several variants of this formalism,
their interest, the relations with noncommutative geometry, the existence (or
lack of existence) of phenomenological predictions, the relation with Lie
super-algebras etc.Comment: pp 20, LaTeX file, no figures, also available via anonymous ftp at
ftp://cpt.univ-mrs.fr/ or via gopher gopher://cpt.univ-mrs.fr
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