Large parallel volumes of finite and compact sets in d-dimensional Euclidean space
DEFF Research Database (Denmark)
Kampf, Jürgen; Kiderlen, Markus
The r-parallel volume V (Cr) of a compact subset C in d-dimensional Euclidean space is the volume of the set Cr of all points of Euclidean distance at most r > 0 from C. According to Steiner’s formula, V (Cr) is a polynomial in r when C is convex. For finite sets C satisfying a certain geometric...
An excursion through elementary mathematics, volume ii euclidean geometry
Caminha Muniz Neto, Antonio
2018-01-01
This book provides a comprehensive, in-depth overview of elementary mathematics as explored in Mathematical Olympiads around the world. It expands on topics usually encountered in high school and could even be used as preparation for a first-semester undergraduate course. This second volume covers Plane Geometry, Trigonometry, Space Geometry, Vectors in the Plane, Solids and much more. As part of a collection, the book differs from other publications in this field by not being a mere selection of questions or a set of tips and tricks that applies to specific problems. It starts from the most basic theoretical principles, without being either too general or too axiomatic. Examples and problems are discussed only if they are helpful as applications of the theory. Propositions are proved in detail and subsequently applied to Olympic problems or to other problems at the Olympic level. The book also explores some of the hardest problems presented at National and International Mathematics Olympiads, as well as many...
Non-Euclidean geometry and curvature two-dimensional spaces, volume 3
Cannon, James W
2017-01-01
This is the final volume of a three volume collection devoted to the geometry, topology, and curvature of 2-dimensional spaces. The collection provides a guided tour through a wide range of topics by one of the twentieth century's masters of geometric topology. The books are accessible to college and graduate students and provide perspective and insight to mathematicians at all levels who are interested in geometry and topology. Einstein showed how to interpret gravity as the dynamic response to the curvature of space-time. Bill Thurston showed us that non-Euclidean geometries and curvature are essential to the understanding of low-dimensional spaces. This third and final volume aims to give the reader a firm intuitive understanding of these concepts in dimension 2. The volume first demonstrates a number of the most important properties of non-Euclidean geometry by means of simple infinite graphs that approximate that geometry. This is followed by a long chapter taken from lectures the author gave at MSRI, wh...
Directory of Open Access Journals (Sweden)
Lambert Marie-Ève
2012-06-01
Full Text Available Abstract Background Porcine reproductive and respiratory syndrome (PRRS is a viral disease that has a major economic impact for the swine industry. Its control is mostly directed towards preventing its spread which requires a better understanding of the mechanisms of transmission of the virus between herds. The objectives of this study were to describe the genetic diversity and to assess the correlation among genetic, Euclidean and temporal distances and ownership to better understand pathways of transmission. Results A cross-sectional study was conducted on sites located in a high density area of swine production in Quebec. Geographical coordinates (longitude/latitude, date of submission and ownership were obtained for each site. ORF5 sequencing was attempted on PRRSV positive sites. Proportion of pairwise combinations of strains having ≥98% genetic homology were analysed according to Euclidean distances and ownership. Correlations between genetic, Euclidean and temporal distances and ownership were assessed using Mantel tests on continuous and binary matrices. Sensitivity of the correlations between genetic and Euclidean as well as temporal distances was evaluated for different Euclidean and temporal distance thresholds. An ORF5 sequence was identified for 132 of the 176 (75% PRRSV positive sites; 122 were wild-type strains. The mean (min-max genetic, Euclidean and temporal pairwise distances were 11.6% (0–18.7, 15.0 km (0.04-45.7 and 218 days (0–852, respectively. Significant positive correlations were observed between genetic and ownership, genetic and Euclidean and between genetic and temporal binary distances. The relationship between genetic and ownership suggests either common sources of animals or semen, employees, technical services or vehicles, whereas that between genetic and Euclidean binary distances is compatible with area spread of the virus. The latter correlation was observed only up to 5 km. Conclusions This study
de Wit, Bernard; Reys, Valentin
2017-12-01
Supergravity with eight supercharges in a four-dimensional Euclidean space is constructed at the full non-linear level by performing an off-shell time-like reduction of five-dimensional supergravity. The resulting four-dimensional theory is realized off-shell with the Weyl, vector and tensor supermultiplets and a corresponding multiplet calculus. Hypermultiplets are included as well, but they are themselves only realized with on-shell supersymmetry. We also briefly discuss the non-linear supermultiplet. The off-shell reduction leads to a full understanding of the Euclidean theory. A complete multiplet calculus is presented along the lines of the Minkowskian theory. Unlike in Minkowski space, chiral and anti-chiral multiplets are real and supersymmetric actions are generally unbounded from below. Precisely as in the Minkowski case, where one has different formulations of Poincaré supergravity upon introducing different compensating supermultiplets, one can also obtain different versions of Euclidean supergravity.
Spacetime and Euclidean geometry
Brill, Dieter; Jacobson, Ted
2006-04-01
Using only the principle of relativity and Euclidean geometry we show in this pedagogical article that the square of proper time or length in a two-dimensional spacetime diagram is proportional to the Euclidean area of the corresponding causal domain. We use this relation to derive the Minkowski line element by two geometric proofs of the spacetime Pythagoras theorem.
Draisma, J.; Horobet, E.; Ottaviani, G.; Sturmfels, B.; Thomas, R.R.; Zhi, L.; Watt, M.
2014-01-01
The nearest point map of a real algebraic variety with respect to Euclidean distance is an algebraic function. For instance, for varieties of low rank matrices, the Eckart-Young Theorem states that this map is given by the singular value decomposition. This article develops a theory of such nearest
Coxeter, HSM
1965-01-01
This textbook introduces non-Euclidean geometry, and the third edition adds a new chapter, including a description of the two families of 'mid-lines' between two given lines and an elementary derivation of the basic formulae of spherical trigonometry and hyperbolic trigonometry, and other new material.
Majorization in Euclidean Geometry and Beyond
Czech Academy of Sciences Publication Activity Database
Fiedler, Miroslav
2015-01-01
Roč. 466, 1 February (2015), s. 233-240 ISSN 0024-3795 Institutional support: RVO:67985807 Keywords : Majorization * Doubly stochastic matrix * Euclidean simplex * Star * Regular simplex * Volume of a simplex Subject RIV: BA - General Mathematics Impact factor: 0.965, year: 2015
Kulczycki, Stefan
2008-01-01
This accessible approach features two varieties of proofs: stereometric and planimetric, as well as elementary proofs that employ only the simplest properties of the plane. A short history of geometry precedes a systematic exposition of the principles of non-Euclidean geometry.Starting with fundamental assumptions, the author examines the theorems of Hjelmslev, mapping a plane into a circle, the angle of parallelism and area of a polygon, regular polygons, straight lines and planes in space, and the horosphere. Further development of the theory covers hyperbolic functions, the geometry of suff
Hoffman, Kenneth
2007-01-01
Developed for an introductory course in mathematical analysis at MIT, this text focuses on concepts, principles, and methods. Its introductions to real and complex analysis are closely formulated, and they constitute a natural introduction to complex function theory.Starting with an overview of the real number system, the text presents results for subsets and functions related to Euclidean space of n dimensions. It offers a rigorous review of the fundamentals of calculus, emphasizing power series expansions and introducing the theory of complex-analytic functions. Subsequent chapters cover seq
Microstructure-Aided Digital Volume Correlation
Directory of Open Access Journals (Sweden)
Hild F.
2010-06-01
Full Text Available This paper describes how volumic images of a composite material could be used to measure 3D displacement ﬁelds, and assess mechanical properties. The exemple of a tensile test performed on a sample made of an energetic material is chosen. Diﬀerent tools are used, namely, X-ray microtomography of an in situ experiment, image acquisition and processing, volume correlation to measure 3D displacement ﬁelds. The principle of an integrated approach is ﬁnally introduced.
Non-euclidean simplex optimization
International Nuclear Information System (INIS)
Silver, G.L.
1977-01-01
Geometric optimization techniques useful for studying chemical equilibrium traditionally rely upon principles of euclidean geometry, but such algorithms may also be based upon principles of a non-euclidean geometry. The sequential simplex method is adapted to the hyperbolic plane, and application of optimization to problems such as the potentiometric titration of plutonium is suggested
High accurate volume holographic correlator with 4000 parallel correlation channels
Ni, Kai; Qu, Zongyao; Cao, Liangcai; Su, Ping; He, Qingsheng; Jin, Guofan
2008-03-01
Volume holographic correlator allows simultaneously calculate the two-dimensional inner product between the input image and each stored image. We have recently experimentally implemented in VHC 4000 parallel correlation channels with better than 98% output accuracy in a single location in a crystal. The speckle modulation is used to suppress the sidelobes of the correlation patterns, allowing more correlation spots to be contained in the output plane. A modified exposure schedule is designed to ensure the hologram in each channel with unity diffraction efficiency. In this schedule, a restricted coefficient was introduced into the original exposure schedule to solve the problem that the sensitivity and time constant of the crystal will change as a time function when in high-capacity storage. An interleaving method is proposed to improve the output accuracy. By unifying the distribution of the input and stored image patterns without changing the inner products between them, this method could eliminate the impact of correlation pattern variety on calculated inner product values. Moreover, by using this method, the maximum correlation spot size is reduced, which decreases the required minimum safe clearance between neighboring spots in the output plane, allowing more spots to be parallely detected without crosstalk. The experimental results are given and analyzed.
Micrononcasual Euclidean wave functions
International Nuclear Information System (INIS)
Enatsu, H.; Takenaka, A.; Okazaki, M.
1978-01-01
A theory which describes the internal attributes of hadrons in terms of space-time wave functions is presented. In order to develop the theory on the basis of a rather realistic model, covariant wave equations are first derived for the deuteron, in which the co-ordinates of the centre of mass of two nucleons can be defined unambiguously. Then the micro-noncasual behaviour of virtual mesons mediating between the two nucleons is expressed by means of wave functions depending only on the relative Euclidean co-ordinates with respect to the centre of mass of the two nucleons; the wave functions are assumed to obey the 0 4 and SU 2 x SU 2 groups. The properties of the wave functions under space inversion, time reversal and particle-antiparticle conjugation are investigated. It is found that the internal attributes of the mesons, such as spin, isospin, strangeness, intrinsic parity, charge parity and G-parity are explained consistently. The theory is applicable also to the case of baryons
International Nuclear Information System (INIS)
Mocsy, A.; Petreczky, P.
2008-01-01
In the past two decades, one of the most important goals of the nuclear physics community has been the production and characterization of the new state of matter--Quark-Gluon Plasma (QGP). Understanding how properties of hadrons change in medium, particularly, the bound state of a very heavy quark and its antiquark, known as quarkonium, as well as determining the transport coefficients is crucial for identifying the properties of QGP and for the understanding of the experimental data from RHIC. On April 23rd, more than sixty physicists from twenty-seven institutions gathered for this three-day topical workshop held at BNL to discuss how to understand the properties of the new state of matter obtained in ultra-relativistic heavy ion collisions (particularly at RHIC-BNL) through spectral functions. In-medium properties of the different particle species and the transport properties of the medium are encoded in spectral functions. The former could yield important signatures of deconfinement and chiral symmetry restoration at high temperatures and densities, while the later are crucial for the understanding of the dynamics of ultra-relativistic heavy ion collisions. Participants at the workshop are experts in various areas of spectral function studies. The workshop encouraged direct exchange of scientific information among experts, as well as between the younger and the more established scientists. The workshops success is evident from the coherent picture that developed of the current understanding of transport properties and in-medium particle properties, illustrated in the current proceedings. The following pages show calculations of meson spectral functions in lattice QCD, as well as implications of these for quarkonia melting/survival in the quark gluon plasma; Lattice calculations of the transport coefficients (shear and bulk viscosities, electric conductivity); Calculation of spectral functions and transport coefficients in field theories using weak coupling techniques; And certain spectral functions and also the heavy quark diffusion constant have been calculated in the strongly coupled limit of the N = 4 super-symmetric Yang Mills theory
Introduction to non-Euclidean geometry
Wolfe, Harold E
2012-01-01
One of the first college-level texts for elementary courses in non-Euclidean geometry, this concise, readable volume is geared toward students familiar with calculus. A full treatment of the historical background explores the centuries-long efforts to prove Euclid's parallel postulate and their triumphant conclusion. Numerous original exercises form an integral part of the book.Topics include hyperbolic plane geometry and hyperbolic plane trigonometry, applications of calculus to the solutions of some problems in hyperbolic geometry, elliptic plane geometry and trigonometry, and the consistenc
Pannopnut, Papinwit; Kitporntheranunt, Maethaphan; Paritakul, Panwara; Kongsomboon, Kittipong
2015-01-01
To investigate the correlation between ultrasound measured placental volume and collected umbilical cord blood (UCB) volume in term pregnancy. An observational cross-sectional study of term singleton pregnant women in the labor ward at Maha Chakri Sirindhorn Medical Center was conducted. Placental thickness, height, and width were measured using two-dimensional (2D) ultrasound and calculated for placental volume using the volumetric mathematic model. After the delivery of the baby, UCB was collected and measured for its volume immediately. Then, birth weight, placental weight, and the actual placental volume were analyzed. The Pearson's correlation was used to determine the correlation between each two variables. A total of 35 pregnant women were eligible for the study. The mean and standard deviation of estimated placental volume and actual placental volume were 534±180 mL and 575±118 mL, respectively. The median UCB volume was 140 mL (range 98-220 mL). The UCB volume did not have a statistically significant correlation with the estimated placental volume (correlation coefficient 0.15; p=0.37). However, the UCB volume was significantly correlated with the actual placental volume (correlation coefficient 0.62; pcorrelation coefficient 0.38; p=0.02). The estimated placental volume by 2D ultrasound was not significantly correlated with the UCB volume. Further studies to establish the correlation between the UCB volume and the estimated placental volume using other types of placental imaging may be needed.
Euclidean approach to the inflationary universe
International Nuclear Information System (INIS)
Hawking, S.W.
1983-01-01
The aim of this article is to show how the Euclidean approach can be used to study the inflationary universe. Although this formulation may appear counterintuitive in some respects, it has the advantage that it defines a definite quantum state and provides a framework for calculating quantities of interest such as correlation functions or tunnelling probabilities. By contrast, in the more usual approach in real Lorentzian spacetime, it is not so clear what the quantum state should be or how to evaluate such quantities. (author)
Physical correlates of radiologic heart volume
International Nuclear Information System (INIS)
Christie, D.
1978-01-01
Radiologic heart volume was calculated on a 10 per cent random sample of subjects examined in the London Civil Service Health Survey. Data were available for 1 188 men over the age of 40, and the importance of correcting radiologic heart volume for body size, age and heart rate was demonstrated. After these variables were taken into account, the most important association found was with blood pressure. Radiologic heart volume has potential value in cardiovascular screening programmes. (Auth.)
Superconvergent perturbation theory for euclidean scalar field theories
International Nuclear Information System (INIS)
Ushveridze, A.G.
1984-01-01
It is shown that the bare (unrenormalized) correlation functions in the euclidean scalar field theories can be expanded in a series whose terms, being computable in a relatively simple way, are free from ultraviolet and infrared divergencies. This series is convergent (divergent) for finite (infinite) values of the correlation functions. (orig.)
Fast Exact Euclidean Distance (FEED) Transformation
Schouten, Theo; Kittler, J.; van den Broek, Egon; Petrou, M.; Nixon, M.
2004-01-01
Fast Exact Euclidean Distance (FEED) transformation is introduced, starting from the inverse of the distance transformation. The prohibitive computational cost of a naive implementation of traditional Euclidean Distance Transformation, is tackled by three operations: restriction of both the number
Ideas of space. Euclidean, non-Euclidean and relativistic
Energy Technology Data Exchange (ETDEWEB)
Gray, J
1979-01-01
An historical and chronological account of mathematics is presented in which familiarity with simple equations and elements of trigonometry is needed but no specialist knowledge is assumed although difficult problems are discussed. By discussion of the difficulties and confusions it is hoped to understand mathematics as a dynamic activity. Beginning with early Greek mathematics, the Eastern legacy and the transition to deductive and geometric thinking the problem of parallels is then encountered and discussed. The second part of the book takes the story from Wallis, Saccheri and Lambert through to its resolution by Gauss, Lobachevskii, Bolyai, Riemann and Bettrami. The background of the 19th century theory of surfaces is given. The third part gives an account of Einstein's theories based on what has gone before, moving from a Newtonian-Euclidean picture to an Einsteinian-nonEuclidean one. A brief account of gravitation, the nature of space and black holes concludes the book.
Cross-correlations in volume space: Differences between buy and sell volumes
Lee, Sun Young; Hwang, Dong Il; Kim, Min Jae; Koh, In Gyu; Kim, Soo Yong
2011-03-01
We study the cross-correlations of buy and sell volumes on the Korean stock market in high frequency. We observe that the pulling effects of volumes are as small as that of returns. The properties of the correlations of buy and sell volumes differ. They are explained by the degree of synchronization of stock volumes. Further, the pulling effects on the minimal spanning tree are studied. In minimal spanning trees with directed links, the large pulling effects are clustered at the center, not uniformly distributed. The Epps effect of buy and sell volumes are observed. The reversal of the cross-correlations of buy and sell volumes is also detected.
Euclidean geometry and its subgeometries
Specht, Edward John; Calkins, Keith G; Rhoads, Donald H
2015-01-01
In this monograph, the authors present a modern development of Euclidean geometry from independent axioms, using up-to-date language and providing detailed proofs. The axioms for incidence, betweenness, and plane separation are close to those of Hilbert. This is the only axiomatic treatment of Euclidean geometry that uses axioms not involving metric notions and that explores congruence and isometries by means of reflection mappings. The authors present thirteen axioms in sequence, proving as many theorems as possible at each stage and, in the process, building up subgeometries, most notably the Pasch and neutral geometries. Standard topics such as the congruence theorems for triangles, embedding the real numbers in a line, and coordinatization of the plane are included, as well as theorems of Pythagoras, Desargues, Pappas, Menelaus, and Ceva. The final chapter covers consistency and independence of axioms, as well as independence of definition properties. There are over 300 exercises; solutions to many of the...
Trudeau, Richard J
1986-01-01
How unique and definitive is Euclidean geometry in describing the "real" space in which we live? Richard Trudeau confronts the fundamental question of truth and its representation through mathematical models in The Non-Euclidean Revolution. First, the author analyzes geometry in its historical and philosophical setting; second, he examines a revolution every bit as significant as the Copernican revolution in astronomy and the Darwinian revolution in biology; third, on the most speculative level, he questions the possibility of absolute knowledge of the world. Trudeau writes in a lively, entertaining, and highly accessible style. His book provides one of the most stimulating and personal presentations of a struggle with the nature of truth in mathematics and the physical world. A portion of the book won the Pólya Prize, a distinguished award from the Mathematical Association of America. "Trudeau meets the challenge of reaching a broad audience in clever ways...(The book) is a good addition to our literature o...
Variational submanifolds of Euclidean spaces
Krupka, D.; Urban, Z.; Volná, J.
2018-03-01
Systems of ordinary differential equations (or dynamical forms in Lagrangian mechanics), induced by embeddings of smooth fibered manifolds over one-dimensional basis, are considered in the class of variational equations. For a given non-variational system, conditions assuring variationality (the Helmholtz conditions) of the induced system with respect to a submanifold of a Euclidean space are studied, and the problem of existence of these "variational submanifolds" is formulated in general and solved for second-order systems. The variational sequence theory on sheaves of differential forms is employed as a main tool for the analysis of local and global aspects (variationality and variational triviality). The theory is illustrated by examples of holonomic constraints (submanifolds of a configuration Euclidean space) which are variational submanifolds in geometry and mechanics.
Growth Modeling of Human Mandibles using Non-Euclidean Metrics
DEFF Research Database (Denmark)
Hilger, Klaus Baggesen; Larsen, Rasmus; Wrobel, Mark
2003-01-01
From a set of 31 three-dimensional CT scans we model the temporal shape and size of the human mandible. Each anatomical structure is represented using 14851 semi-landmarks, and mapped into Procrustes tangent space. Exploratory subspace analyses are performed leading to linear models of mandible...... shape evolution in Procrustes space. The traditional variance analysis results in a one-dimensional growth model. However, working in a non-Euclidean metric results in a multimodal model with uncorrelated modes of biological variation. The applied non-Euclidean metric is governed by the correlation...... structure of the estimated noise in the data. The generative models are compared, and evaluated on the basis of a cross validation study. The new non-Euclidean analysis is completely data driven. It not only gives comparable results w.r.t. to previous studies of the mean modelling error, but in addition...
Euclidean Monte Carlo simulation of nuclear interactions
International Nuclear Information System (INIS)
Montvay, Istvan; Bonn Univ.; Urbach, Carsten
2011-05-01
We present an exploratory study of chiral effective theories of nuclei with methods adopted from lattice quantum chromodynamics (QCD). We show that the simulations in the Euclidean path integral approach are feasible and that we can determine the energy of the two nucleon state. By varying the parameters and the simulated volumes phase shifts can be determined in principle and hopefully tuned to their physical values in the future. The physical cut-off of the theory is realised by blocking of the lattice fields. By keeping this physical cut-off fixed in physical units the lattice cut-off can be changed and in this way the lattice artefacts can be eliminated. (orig.)
Random walks in Euclidean space
Varjú, Péter Pál
2012-01-01
Consider a sequence of independent random isometries of Euclidean space with a previously fixed probability law. Apply these isometries successively to the origin and consider the sequence of random points that we obtain this way. We prove a local limit theorem under a suitable moment condition and a necessary non-degeneracy condition. Under stronger hypothesis, we prove a limit theorem on a wide range of scales: between e^(-cl^(1/4)) and l^(1/2), where l is the number of steps.
Phylogenetic trees and Euclidean embeddings.
Layer, Mark; Rhodes, John A
2017-01-01
It was recently observed by de Vienne et al. (Syst Biol 60(6):826-832, 2011) that a simple square root transformation of distances between taxa on a phylogenetic tree allowed for an embedding of the taxa into Euclidean space. While the justification for this was based on a diffusion model of continuous character evolution along the tree, here we give a direct and elementary explanation for it that provides substantial additional insight. We use this embedding to reinterpret the differences between the NJ and BIONJ tree building algorithms, providing one illustration of how this embedding reflects tree structures in data.
Noncommutative products of Euclidean spaces
Dubois-Violette, Michel; Landi, Giovanni
2018-05-01
We present natural families of coordinate algebras on noncommutative products of Euclidean spaces R^{N_1} × _R R^{N_2} . These coordinate algebras are quadratic ones associated with an R -matrix which is involutive and satisfies the Yang-Baxter equations. As a consequence, they enjoy a list of nice properties, being regular of finite global dimension. Notably, we have eight-dimensional noncommutative euclidean spaces R4 × _R R4 . Among these, particularly well behaved ones have deformation parameter u \\in S^2 . Quotients include seven spheres S7_u as well as noncommutative quaternionic tori TH_u = S^3 × _u S^3 . There is invariance for an action of {{SU}}(2) × {{SU}}(2) on the torus TH_u in parallel with the action of U(1) × U(1) on a `complex' noncommutative torus T^2_θ which allows one to construct quaternionic toric noncommutative manifolds. Additional classes of solutions are disjoint from the classical case.
No Correlation Between Work-Hours and Operative Volumes
DEFF Research Database (Denmark)
Kjærgaard, Jane; Sillesen, Martin; Beier-Holgersen, Randi
2016-01-01
OBJECTIVE: Since 2003, United States residents have been limited to an 80-hour workweek. This has prompted concerns of reduced educational quality, especially inadequate operating exposure. In contrast, the Danish surgical specialty-training program mandates a cap on working hours of 37 per week....... We hypothesize that there is no direct correlation between work-hours and operative volume achieved during surgical residency. To test the hypothesis, we compare Danish and US operative volumes achieved during surgical residency training. DESIGN: Retrospective comparative study. PARTICIPANTS...... find no difference in overall surgical volumes between Danes and US residents during their surgical training. When time in training was accounted for, differences between weekly surgical volumes achieved were minor, indicating a lack of direct correlation between weekly work-hours and operative volumes...
Euclidean distance degrees of real algebraic groups
Baaijens, J.A.; Draisma, J.
2015-01-01
We study the problem of finding, in a real algebraic matrix group, the matrix closest to a given data matrix. We do so from the algebro-geometric perspective of Euclidean distance degrees. We recover several classical results; and among the new results that we prove is a formula for the Euclidean
Euclidean distance degrees of real algebraic groups
Baaijens, J.A.; Draisma, J.
2014-01-01
We study the problem of finding, in a real algebraic matrix group, the matrix closest to a given data matrix. We do so from the algebro-geometric perspective of Euclidean distance degrees. We recover several classical results; and among the new results that we prove is a formula for the Euclidean
Euclidean supersymmetry, twisting and topological sigma models
International Nuclear Information System (INIS)
Hull, C.M.; Lindstroem, U.; Santos, L. Melo dos; Zabzine, M.; Unge, R. von
2008-01-01
We discuss two dimensional N-extended supersymmetry in Euclidean signature and its R-symmetry. For N = 2, the R-symmetry is SO(2) x SO(1, 1), so that only an A-twist is possible. To formulate a B-twist, or to construct Euclidean N = 2 models with H-flux so that the target geometry is generalised Kahler, it is necessary to work with a complexification of the sigma models. These issues are related to the obstructions to the existence of non-trivial twisted chiral superfields in Euclidean superspace.
Local algebras in Euclidean quantum field theory
International Nuclear Information System (INIS)
Guerra, Francesco.
1975-06-01
The general structure of the local observable algebras of Euclidean quantum field theory is described, considering the very simple examples of the free scalar field, the vector meson field, and the electromagnetic field. The role of Markov properties, and the relations between Euclidean theory and Hamiltonian theory in Minkowski space-time are especially emphasized. No conflict appears between covariance (in the Euclidean sense) and locality (in the Markov sense) on one hand and positive definiteness of the metric on the other hand [fr
Read-only high accuracy volume holographic optical correlator
Zhao, Tian; Li, Jingming; Cao, Liangcai; He, Qingsheng; Jin, Guofan
2011-10-01
A read-only volume holographic correlator (VHC) is proposed. After the recording of all of the correlation database pages by angular multiplexing, a stand-alone read-only high accuracy VHC will be separated from the VHC recording facilities which include the high-power laser and the angular multiplexing system. The stand-alone VHC has its own low power readout laser and very compact and simple structure. Since there are two lasers that are employed for recording and readout, respectively, the optical alignment tolerance of the laser illumination on the SLM is very sensitive. The twodimensional angular tolerance is analyzed based on the theoretical model of the volume holographic correlator. The experimental demonstration of the proposed read-only VHC is introduced and discussed.
Learning Euclidean Embeddings for Indexing and Classification
National Research Council Canada - National Science Library
Athitsos, Vassilis; Alon, Joni; Sclaroff, Stan; Kollios, George
2004-01-01
BoostMap is a recently proposed method for efficient approximate nearest neighbor retrieval in arbitrary non-Euclidean spaces with computationally expensive and possibly non-metric distance measures...
The elements of non-Euclidean geometry
Sommerville, D MY
2012-01-01
Renowned for its lucid yet meticulous exposition, this classic allows students to follow the development of non-Euclidean geometry from a fundamental analysis of the concept of parallelism to more advanced topics. 1914 edition. Includes 133 figures.
Scaling limits of Euclidean quantum fields
International Nuclear Information System (INIS)
Enss, V.
1981-01-01
The author studies the long-distance and short-distance behaviour of generalized random processes which arise in Euclidean Boson field theories. Among them are Wick-polynomials of free fields and P(PHI) 2 -models. (Auth.)
Axioms for Euclidean Green's functions. Pt. 2
International Nuclear Information System (INIS)
Osterwalder, K.; Schrader, R.
1975-01-01
We give new (necessary and) sufficient conditions for Euclidean Green's functions to have analytic continuations to a relativistic field theory. These results extend and correct a previous paper. (orig.) [de
Constructive curves in non-Euclidean planes
Horváth, Ákos G.
2016-01-01
In this paper we overview the theory of conics and roulettes in four non-Euclidean planes. We collect the literature about these classical concepts, from the eighteenth century to the present, including papers available only on arXiv. The comparison of the four non-Euclidean planes, in terms of the known results on conics and roulettes, reflects only the very subjective view of the author.
Classical geometry Euclidean, transformational, inversive, and projective
Leonard, I E; Liu, A C F; Tokarsky, G W
2014-01-01
Features the classical themes of geometry with plentiful applications in mathematics, education, engineering, and science Accessible and reader-friendly, Classical Geometry: Euclidean, Transformational, Inversive, and Projective introduces readers to a valuable discipline that is crucial to understanding bothspatial relationships and logical reasoning. Focusing on the development of geometric intuitionwhile avoiding the axiomatic method, a problem solving approach is encouraged throughout. The book is strategically divided into three sections: Part One focuses on Euclidean geometry, which p
Fuzzy Euclidean wormholes in de Sitter space
Energy Technology Data Exchange (ETDEWEB)
Chen, Pisin; Hu, Yao-Chieh; Yeom, Dong-han, E-mail: pisinchen@phys.ntu.edu.tw, E-mail: r04244003@ntu.edu.tw, E-mail: innocent.yeom@gmail.com [Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei 10617, Taiwan (China)
2017-07-01
We investigate Euclidean wormholes in Einstein gravity with a massless scalar field in de Sitter space. Euclidean wormholes are possible due to the analytic continuation of the time as well as complexification of fields, where we need to impose the classicality after the Wick-rotation to the Lorentzian signatures. For some parameters, wormholes are preferred than Hawking-Moss instantons, and hence wormholes can be more fundamental than Hawking-Moss type instantons. Euclidean wormholes can be interpreted in three ways: (1) classical big bounce, (2) either tunneling from a small to a large universe or a creation of a collapsing and an expanding universe from nothing, and (3) either a transition from a contracting to a bouncing phase or a creation of two expanding universes from nothing. These various interpretations shed some light on challenges of singularities. In addition, these will help to understand tensions between various kinds of quantum gravity theories.
Lorentz violations and Euclidean signature metrics
International Nuclear Information System (INIS)
Barbero G, J. Fernando; Villasenor, Eduardo J.S.
2003-01-01
We show that the families of effective actions considered by Jacobson et al. to study Lorentz invariance violations contain a class of models that represent pure general relativity with a Euclidean signature. We also point out that some members of this family of actions preserve Lorentz invariance in a generalized sense
MEDOF - MINIMUM EUCLIDEAN DISTANCE OPTIMAL FILTER
Barton, R. S.
1994-01-01
The Minimum Euclidean Distance Optimal Filter program, MEDOF, generates filters for use in optical correlators. The algorithm implemented in MEDOF follows theory put forth by Richard D. Juday of NASA/JSC. This program analytically optimizes filters on arbitrary spatial light modulators such as coupled, binary, full complex, and fractional 2pi phase. MEDOF optimizes these modulators on a number of metrics including: correlation peak intensity at the origin for the centered appearance of the reference image in the input plane, signal to noise ratio including the correlation detector noise as well as the colored additive input noise, peak to correlation energy defined as the fraction of the signal energy passed by the filter that shows up in the correlation spot, and the peak to total energy which is a generalization of PCE that adds the passed colored input noise to the input image's passed energy. The user of MEDOF supplies the functions that describe the following quantities: 1) the reference signal, 2) the realizable complex encodings of both the input and filter SLM, 3) the noise model, possibly colored, as it adds at the reference image and at the correlation detection plane, and 4) the metric to analyze, here taken to be one of the analytical ones like SNR (signal to noise ratio) or PCE (peak to correlation energy) rather than peak to secondary ratio. MEDOF calculates filters for arbitrary modulators and a wide range of metrics as described above. MEDOF examines the statistics of the encoded input image's noise (if SNR or PCE is selected) and the filter SLM's (Spatial Light Modulator) available values. These statistics are used as the basis of a range for searching for the magnitude and phase of k, a pragmatically based complex constant for computing the filter transmittance from the electric field. The filter is produced for the mesh points in those ranges and the value of the metric that results from these points is computed. When the search is concluded, the
International Nuclear Information System (INIS)
Saveliev, M.V.
1983-01-01
In the framework of the algebraic approach a construction of exactly integrable two-dimensional Riemannian manifolds embedded into enveloping Euclidean (pseudo-Euclidean) space Rsub(N) of an arbitrary dimension is presented. The construction is based on a reformulation of the Gauss, Peterson-Codazzi and Ricci equations in the form of a Lax-type representation in two-dimensional space. Here the Lax pair operators take the values in algebra SO(N)
A linear-time algorithm for Euclidean feature transform sets
Hesselink, Wim H.
2007-01-01
The Euclidean distance transform of a binary image is the function that assigns to every pixel the Euclidean distance to the background. The Euclidean feature transform is the function that assigns to every pixel the set of background pixels with this distance. We present an algorithm to compute the
Euclidean wormholes with minimally coupled scalar fields
International Nuclear Information System (INIS)
Ruz, Soumendranath; Modak, Bijan; Debnath, Subhra; Sanyal, Abhik Kumar
2013-01-01
A detailed study of quantum and semiclassical Euclidean wormholes for Einstein's theory with a minimally coupled scalar field has been performed for a class of potentials. Massless, constant, massive (quadratic in the scalar field) and inverse (linear) potentials admit the Hawking and Page wormhole boundary condition both in the classically forbidden and allowed regions. An inverse quartic potential has been found to exhibit a semiclassical wormhole configuration. Classical wormholes under a suitable back-reaction leading to a finite radius of the throat, where the strong energy condition is satisfied, have been found for the zero, constant, quadratic and exponential potentials. Treating such classical Euclidean wormholes as an initial condition, a late stage of cosmological evolution has been found to remain unaltered from standard Friedmann cosmology, except for the constant potential which under the back-reaction produces a term like a negative cosmological constant. (paper)
Calculus and analysis in Euclidean space
Shurman, Jerry
2016-01-01
The graceful role of analysis in underpinning calculus is often lost to their separation in the curriculum. This book entwines the two subjects, providing a conceptual approach to multivariable calculus closely supported by the structure and reasoning of analysis. The setting is Euclidean space, with the material on differentiation culminating in the inverse and implicit function theorems, and the material on integration culminating in the general fundamental theorem of integral calculus. More in-depth than most calculus books but less technical than a typical analysis introduction, Calculus and Analysis in Euclidean Space offers a rich blend of content to students outside the traditional mathematics major, while also providing transitional preparation for those who will continue on in the subject. The writing in this book aims to convey the intent of ideas early in discussion. The narrative proceeds through figures, formulas, and text, guiding the reader to do mathematics resourcefully by marshaling the skil...
Image scale measurement with correlation filters in a volume holographic optical correlator
Zheng, Tianxiang; Cao, Liangcai; He, Qingsheng; Jin, Guofan
2013-08-01
A search engine containing various target images or different part of a large scene area is of great use for many applications, including object detection, biometric recognition, and image registration. The input image captured in realtime is compared with all the template images in the search engine. A volume holographic correlator is one type of these search engines. It performs thousands of comparisons among the images at a super high speed, with the correlation task accomplishing mainly in optics. However, the inputted target image always contains scale variation to the filtering template images. At the time, the correlation values cannot properly reflect the similarity of the images. It is essential to estimate and eliminate the scale variation of the inputted target image. There are three domains for performing the scale measurement, as spatial, spectral and time domains. Most methods dealing with the scale factor are based on the spatial or the spectral domains. In this paper, a method with the time domain is proposed to measure the scale factor of the input image. It is called a time-sequential scaled method. The method utilizes the relationship between the scale variation and the correlation value of two images. It sends a few artificially scaled input images to compare with the template images. The correlation value increases and decreases with the increasing of the scale factor at the intervals of 0.8~1 and 1~1.2, respectively. The original scale of the input image can be measured by estimating the largest correlation value through correlating the artificially scaled input image with the template images. The measurement range for the scale can be 0.8~4.8. Scale factor beyond 1.2 is measured by scaling the input image at the factor of 1/2, 1/3 and 1/4, correlating the artificially scaled input image with the template images, and estimating the new corresponding scale factor inside 0.8~1.2.
Euclidean fields: vector mesons and photons
International Nuclear Information System (INIS)
Loffelholz, J.
1979-01-01
Free transverse vector fields of mass >= 0 are studied. The model is related to the usual free vector meson and electromagnetic quantum field theories by extension of the field operators from transverse to arbitrary test functions. The one-particle states in transverse gauge and their localization are described. Reflexion positivity is proved and derived are free Feynman-Kac-Nelson formulas. An Euclidean approach to a photon field in a spherical world using dilatation covariance and inversions is given
Matrices and Graphs in Euclidean Geometry
Czech Academy of Sciences Publication Activity Database
Fiedler, Miroslav
2005-01-01
Roč. 14, - (2005), s. 51-58 E-ISSN 1081-3810 R&D Projects: GA AV ČR IAA1030302 Institutional research plan: CEZ:AV0Z10300504 Keywords : Euclidean space * Gram matrix * biorthogonal bases * simplex * interior angle * Steiner circumscribed ellipsoid * right simplex Subject RIV: BA - General Mathematics http://www.math.technion.ac.il/iic/ ela / ela -articles/14.html
Correlation between orbital volume, body mass index, and eyeball position in healthy East asians.
Yoo, Jun Ho; Lee, Young Hen; Lee, Hwa; Kim, Jung Wan; Chang, Minwook; Park, Minsoo; Baek, Sehyun
2013-05-01
The objectives of this study were measure the orbital volume of healthy Koreans and analyze the differences between orbital tissue volume with respect to age and sex and to assess any correlation between body mass index (BMI), eyeball position, and orbital volume. We retrospectively evaluated the scan results of patients who had undergone orbital computed tomography scans between November 2010 and November 2011. We assessed the scan results of 184 orbits in 92 adults who had no pathology of the orbit. The individuals were classified into 3 groups with respect to age. Orbital volume, effective orbital volume (defined as the difference between orbital and eyeball volume), extraocular muscle volume, orbital fat volume, and transverse globe protrusion were recorded and analyzed. The records of the subjects were reviewed retrospectively, and BMI was calculated. A correlation analysis was performed to investigate the correlation between BMI, eyeball position, and orbital volume. Orbital tissue volume, with the exception of orbital fat volume, was larger in men compared with women. In both sexes, orbital fat volume increased with increasing age, whereas the other volumes decreased. Orbital tissue volumes increased with increasing BMI, but transverse globe protrusion was not significantly related to BMI. In addition, orbital volume and effective orbital volume were positively correlated with transverse globe protrusion. These results provide basic information about the effects of age, sex, and BMI on orbital volume and eyeball position in healthy Koreans. Furthermore, these results will be helpful in the diagnosis of orbital diseases and in planning orbital surgeries.
Hubble expansion in a Euclidean framework
International Nuclear Information System (INIS)
Alfven, H.
1979-01-01
There now seems to be strong evidence for a non-cosmological interpretation of the QSO redshift - in any case, so strong that it is of interest to investigate the consequences. The purpose of this paper is to construct a model of the Hubble expansion which is as far as possible from the conventional Big Bang model without coming in conflict with any well-established observational results (while introducing no new laws of physics). This leads to an essentially Euclidean metagalactic model (see Table I) with very little mass outside one-third or half of the Hubble radius. The total kinetic energy of the Hubble expansion need only to be about 5% of the rest mass energy. Present observations support backwards in time extrapolation of the Hubble expansion to a 'minimum size galaxy' Rsub(m), which may have any value in 0 26 cm. Other arguments speak in favor of a size close to the upper value, say Rsub(m) = 10 26 cm (Table II). As this size is probably about 100 times the Schwarzschild limit, an essentially Euclidean description is allowed. The kinetic energy of the Hubble expansion may derive from an intense QSO-like activity in the minimum size metagalaxy, with an energy release corresponding to the annihilation of a few solar masses per galaxy per year. Some of the conclusions based on the Big Bang hypothesis are criticized and in several cases alternative interpretations are suggested. A comparison between the Euclidean and the conventional models is given in Table III. (orig.)
Exploring Concepts of Geometry not Euclidean
Directory of Open Access Journals (Sweden)
Luiz Ambrozi
2016-02-01
Full Text Available With this article we intend to propose different situations of teaching and learning, how they can be applied in schools, mediated by the use of concrete materials and Geogebra software, emphasizing the use of technology in the classroom, that this proposal has the role of assisting in the conceptualization and identification of elements of non-Euclidean geometry. In addition, this short course is designed to be a time of current and continuing education for teachers, with activities to be developed with dynamic geometry and based on the theory of Conceptual Fields of Vergnaud.
Bochner-Riesz means on Euclidean spaces
Lu, Shanzhen
2013-01-01
This book mainly deals with the Bochner-Riesz means of multiple Fourier integral and series on Euclidean spaces. It aims to give a systematical introduction to the fundamental theories of the Bochner-Riesz means and important achievements attained in the last 50 years. For the Bochner-Riesz means of multiple Fourier integral, it includes the Fefferman theorem which negates the Disc multiplier conjecture, the famous Carleson-Sjölin theorem, and Carbery-Rubio de Francia-Vega's work on almost everywhere convergence of the Bochner-Riesz means below the critical index. For the Bochner-Riesz means o
Broadband invisibility by non-Euclidean cloaking.
Leonhardt, Ulf; Tyc, Tomás
2009-01-02
Invisibility and negative refraction are both applications of transformation optics where the material of a device performs a coordinate transformation for electromagnetic fields. The device creates the illusion that light propagates through empty flat space, whereas in physical space, light is bent around a hidden interior or seems to run backward in space or time. All of the previous proposals for invisibility require materials with extreme properties. Here we show that transformation optics of a curved, non-Euclidean space (such as the surface of a virtual sphere) relax these requirements and can lead to invisibility in a broad band of the spectrum.
Non-Euclidean Geometry and Gravitation
Directory of Open Access Journals (Sweden)
Stavroulakis N.
2006-04-01
Full Text Available A great deal of misunderstandings and mathematical errors are involved in the currently accepted theory of the gravitational field generated by an isotropic spherical mass. The purpose of the present paper is to provide a short account of the rigorous mathematical theory and exhibit a new formulation of the problem. The solution of the corresponding equations of gravitation points out several new and unusual features of the stationary gravitational field which are related to the non-Euclidean structure of the space. Moreover it precludes the black hole from being a mathematical and physical notion.
Uniform Page Migration Problem in Euclidean Space
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Amanj Khorramian
2016-08-01
Full Text Available The page migration problem in Euclidean space is revisited. In this problem, online requests occur at any location to access a single page located at a server. Every request must be served, and the server has the choice to migrate from its current location to a new location in space. Each service costs the Euclidean distance between the server and request. A migration costs the distance between the former and the new server location, multiplied by the page size. We study the problem in the uniform model, in which the page has size D = 1 . All request locations are not known in advance; however, they are sequentially presented in an online fashion. We design a 2.75 -competitive online algorithm that improves the current best upper bound for the problem with the unit page size. We also provide a lower bound of 2.732 for our algorithm. It was already known that 2.5 is a lower bound for this problem.
Statistical mechanics, gravity, and Euclidean theory
International Nuclear Information System (INIS)
Fursaev, Dmitri V.
2002-01-01
A review of computations of free energy for Gibbs states on stationary but not static gravitational and gauge backgrounds is given. On these backgrounds wave equations for free fields are reduced to eigenvalue problems which depend non-linearly on the spectral parameter. We present a method to deal with such problems. In particular, we demonstrate how some results of the spectral theory of second-order elliptic operators, such as heat kernel asymptotics, can be extended to a class of non-linear spectral problems. The method is used to trace down the relation between the canonical definition of the free energy based on summation over the modes and the covariant definition given in Euclidean quantum gravity. As an application, high-temperature asymptotics of the free energy and of the thermal part of the stress-energy tensor in the presence of rotation are derived. We also discuss statistical mechanics in the presence of Killing horizons where canonical and Euclidean theories are related in a non-trivial way
On the scaling limits in the Euclidean (quantum) field theory
International Nuclear Information System (INIS)
Gielerak, R.
1983-01-01
The author studies the concept of scaling limits in the context of the constructive field theory. He finds that the domain of attraction of a free massless Euclidean scalar field in the two-dimensional space time contains almost all Euclidean self-interacting models of quantum fields so far constructed. The renormalized scaling limit of the Wick polynomials of several self-interacting Euclidean field theory models are shown to be the same as in the free field theory. (Auth.)
Founding Gravitation in 4D Euclidean Space-Time Geometry
International Nuclear Information System (INIS)
Winkler, Franz-Guenter
2010-01-01
The Euclidean interpretation of special relativity which has been suggested by the author is a formulation of special relativity in ordinary 4D Euclidean space-time geometry. The natural and geometrically intuitive generalization of this view involves variations of the speed of light (depending on location and direction) and a Euclidean principle of general covariance. In this article, a gravitation model by Jan Broekaert, which implements a view of relativity theory in the spirit of Lorentz and Poincare, is reconstructed and shown to fulfill the principles of the Euclidean approach after an appropriate reinterpretation.
Correlation among body height, intelligence, and brain gray matter volume in healthy children.
Taki, Yasuyuki; Hashizume, Hiroshi; Sassa, Yuko; Takeuchi, Hikaru; Asano, Michiko; Asano, Kohei; Kotozaki, Yuka; Nouchi, Rui; Wu, Kai; Fukuda, Hiroshi; Kawashima, Ryuta
2012-01-16
A significant positive correlation between height and intelligence has been demonstrated in children. Additionally, intelligence has been associated with the volume of gray matter in the brains of children. Based on these correlations, we analyzed the correlation among height, full-scale intelligence quotient (IQ) and gray matter volume applying voxel-based morphometry using data from the brain magnetic resonance images of 160 healthy children aged 5-18 years of age. As a result, body height was significantly positively correlated with brain gray matter volume. Additionally, the regional gray matter volume of several regions such as the bilateral prefrontal cortices, temporoparietal region, and cerebellum was significantly positively correlated with body height and that the gray matter volume of several of these regions was also significantly positively correlated with full-scale intelligence quotient (IQ) scores after adjusting for age, sex, and socioeconomic status. Our results demonstrate that gray and white matter volume may mediate the correlation between body height and intelligence in healthy children. Additionally, the correlations among gray and white matter volume, height, and intelligence may be at least partially explained by the effect of insulin-like growth factor-1 and growth hormones. Given the importance of the effect of environmental factors, especially nutrition, on height, IQ, and gray matter volume, the present results stress the importance of nutrition during childhood for the healthy maturation of body and brain. Copyright © 2011 Elsevier Inc. All rights reserved.
Euclidean supergravity and multi-centered solutions
Directory of Open Access Journals (Sweden)
W.A. Sabra
2017-04-01
Full Text Available In ungauged supergravity theories, the no-force condition for BPS states implies the existence of stable static multi-centered solutions. The first solutions to Einstein–Maxwell theory with a positive cosmological constant describing an arbitrary number of charged black holes were found by Kastor and Traschen. Generalisations to five and higher dimensional theories were obtained by London. Multi-centered solutions in gauged supergravity, even with time-dependence allowed, have yet to be constructed. In this letter we construct supersymmetry-preserving multi-centered solutions for the case of D=5, N=2 Euclidean gauged supergravity coupled to an arbitrary number of vector multiplets. Higher dimensional Einstein–Maxwell multi-centered solutions are also presented.
The relation between Euclidean and Lorentzian 2D quantum gravity
Ambjørn, J.; Correia, J.; Kristjansen, C.; Loll, R.
1999-01-01
Starting from 2D Euclidean quantum gravity, we show that one recovers 2D Lorentzian quantum gravity by removing all baby universes. Using a peeling procedure to decompose the discrete, triangulated geometries along a one-dimensional path, we explicitly associate with each Euclidean space-time a
Euclidean null controllability of perturbed infinite delay systems with ...
African Journals Online (AJOL)
Euclidean null controllability of perturbed infinite delay systems with limited control. ... Open Access DOWNLOAD FULL TEXT ... The results are established by placing conditions on the perturbation function which guarantee that, if the linear control base system is completely Euclidean controllable, then the perturbed system ...
Euclidean null controllability of nonlinear infinite delay systems with ...
African Journals Online (AJOL)
Sufficient conditions for the Euclidean null controllability of non-linear delay systems with time varying multiple delays in the control and implicit derivative are derived. If the uncontrolled system is uniformly asymptotically stable and if the control system is controllable, then the non-linear infinite delay system is Euclidean null ...
Euclidean null controllability of linear systems with delays in state ...
African Journals Online (AJOL)
Sufficient conditions are developed for the Euclidean controllability of linear systems with delay in state and in control. Namely, if the uncontrolled system is uniformly asymptotically stable and the control equation proper, then the control system is Euclidean null controllable. Journal of the Nigerian Association of ...
Correlation determination for the free air chamber volume
International Nuclear Information System (INIS)
Cardoso, R.S.; Peixoto, J.G.P.
2017-01-01
Ionization chambers are, in principle, the simplest gaseous detectors. Its normal operation is based on the all charges collection created by gas volume direct ionization, through the application of an electric field. In order to guarantee the measurements’ traceability obtained during the comparison with the BIPM, new tests were performed. (author)
Extended supersymmetry in four-dimensional Euclidean space
International Nuclear Information System (INIS)
McKeon, D.G.C.; Sherry, T.N.
2000-01-01
Since the generators of the two SU(2) groups which comprise SO(4) are not Hermitian conjugates of each other, the simplest supersymmetry algebra in four-dimensional Euclidean space more closely resembles the N=2 than the N=1 supersymmetry algebra in four-dimensional Minkowski space. An extended supersymmetry algebra in four-dimensional Euclidean space is considered in this paper; its structure resembles that of N=4 supersymmetry in four-dimensional Minkowski space. The relationship of this algebra to the algebra found by dimensionally reducing the N=1 supersymmetry algebra in ten-dimensional Euclidean space to four-dimensional Euclidean space is examined. The dimensional reduction of N=1 super Yang-Mills theory in ten-dimensional Minkowski space to four-dimensional Euclidean space is also considered
International Nuclear Information System (INIS)
Murphy, James D.; Chisholm, Karen M.; Daly, Megan E.; Wiegner, Ellen A.; Truong, Daniel; Iagaru, Andrei; Maxim, Peter G.; Loo, Billy W.; Graves, Edward E.; Kaplan, Michael J.; Kong, Christina; Le, Quynh-Thu
2011-01-01
Purpose: To explore the relationship between pathologic tumor volume and volume estimated from different tumor segmentation techniques on 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in oral cavity cancer. Materials and methods: Twenty-three patients with squamous cell carcinoma of the oral tongue had PET–CT scans before definitive surgery. Pathologic tumor volume was estimated from surgical specimens. Metabolic tumor volume (MTV) was defined from PET–CT scans as the volume of tumor above a given SUV threshold. Multiple SUV thresholds were explored including absolute SUV thresholds, relative SUV thresholds, and gradient-based techniques. Results: Multiple MTV’s were associated with pathologic tumor volume; however the correlation was poor (R 2 range 0.29–0.58). The ideal SUV threshold, defined as the SUV that generates an MTV equal to pathologic tumor volume, was independently associated with maximum SUV (p = 0.0005) and tumor grade (p = 0.024). MTV defined as a function of maximum SUV and tumor grade improved the prediction of pathologic tumor volume (R 2 = 0.63). Conclusions: Common SUV thresholds fail to predict pathologic tumor volume in head and neck cancer. The optimal technique that allows for integration of PET–CT with radiation treatment planning remains to be defined. Future investigation should incorporate biomarkers such as tumor grade into definitions of MTV.
Walwyn, Amy L.; Navarro, Daniel J.
2010-01-01
An experiment is reported comparing human performance on two kinds of visually presented traveling salesperson problems (TSPs), those reliant on Euclidean geometry and those reliant on city block geometry. Across multiple array sizes, human performance was near-optimal in both geometries, but was slightly better in the Euclidean format. Even so,…
Tonsil volume, tonsil grade and obstructive sleep apnea: is there any meaningful correlation?
Directory of Open Access Journals (Sweden)
Michel Burihan Cahali
2011-01-01
Full Text Available OBJECTIVES: The aims of this study were to evaluate the correlation between oropharyngeal examination and objective palatine tonsil volume in snoring adults and verify the influence of the oropharyngeal anatomy, body mass index, age, and severity of obstructive sleep apnea on actual tonsil volume. In addition, we aimed to assess the influence of tonsil size on obstructive sleep apnea in adults. INTRODUCTION: Pharyngeal wall geometry is often altered in adults who have obstructive sleep apnea, and this might influence the findings of the oropharyngeal examination that, in turn, are the key factors when considering surgical management for this condition. Furthermore, the correlation between the actual tonsil volume and the severity of obstructive sleep apnea in adults is currently unknown. METHODS: We prospectively studied 130 patients with obstructive sleep apnea or primary snoring who underwent pharyngeal surgery with intraoperative measurement of tonsil volume. We compared tonsil volume with preoperative polysomnography, oropharyngeal examination, and anthropometric data. RESULTS: We found a significant correlation between actual tonsil volume and subjective tonsil grade. We also found a significant correlation between tonsil volume and the apnea-hypopnea index. Using a multivariate linear regression model, tonsil volume was found to be significantly correlated with age, body mass index, and oropharyngeal examination, but not with polysomnography. Clinically, only the rare tonsil grade IV was indicative of more severe obstructive sleep apnea. CONCLUSIONS: There is a strong correlation between clinical tonsil grade and objective tonsil volume in snoring adults, and this correlation exists regardless of the presence or severity of obstructive sleep apnea. Pharyngeal tissue volume likely reflects the body mass index rather than obstructive sleep apnea severity.
Mean platelet volume in brucellosis: correlation between brucella ...
African Journals Online (AJOL)
Background: Brucellosis, a zoonotic infection, was most widely diagnosed by the Brucella standard serum agglutination test (SAT). No previous publication has demonstrated a correlation between the degree of Brucella SAT agglutination positivity and the severity of brucellosis infection. Objective: To contribute to the ...
Spinors in euclidean field theory, complex structures and discrete symmetries
International Nuclear Information System (INIS)
Wetterich, C.
2011-01-01
We discuss fermions for arbitrary dimensions and signature of the metric, with special emphasis on euclidean space. Generalized Majorana spinors are defined for d=2,3,4,8,9mod8, independently of the signature. These objects permit a consistent analytic continuation of Majorana spinors in Minkowski space to euclidean signature. Compatibility of charge conjugation with complex conjugation requires for euclidean signature a new complex structure which involves a reflection in euclidean time. The possible complex structures for Minkowski and euclidean signature can be understood in terms of a modulo two periodicity in the signature. The concepts of a real action and hermitean observables depend on the choice of the complex structure. For a real action the expectation values of all hermitean multi-fermion observables are real. This holds for arbitrary signature, including euclidean space. In particular, a chemical potential is compatible with a real action for the euclidean theory. We also discuss the discrete symmetries of parity, time reversal and charge conjugation for arbitrary dimension and signature.
International Nuclear Information System (INIS)
Shpotyuk, O.; Ingram, A.; Shpotyuk, M.; Filipecki, J.
2014-01-01
Highlights: • Decisive role of specific chemical environment in free-volume correlations in glass. • Realistic free volumes in As–S/Se glass are defined by newly modified τ 2 -R formula. • Overestimated void sizes in chalcogenide glass as compared with molecular polymers. - Abstract: A newly modified correlation equation between defect-related positron lifetime determined within two-state trapping model and radius of corresponding free-volume-type defects was proposed to describe compositional variations in atomic-deficient structure of covalent-bonded chalcogenides like binary As–S/Se glasses. Specific chemical environment of free-volume voids around neighboring network-forming polyhedrons was shown to play a decisive role in this correlation, leading to systematically enhanced volumes in comparison with typical molecular substrates, such as polymers
Energy Technology Data Exchange (ETDEWEB)
Shpotyuk, O., E-mail: shpotyuk@novas.lviv.ua [Institute of Materials of SRC “Carat”, 212 Stryjska Str., Lviv 79031 (Ukraine); Institute of Physics of Jan Dlugosz University, 13/15 al. Armii Krajowej, Czestcochowa 42200 (Poland); Ingram, A. [Opole University of Technology, 75 Ozimska Str., Opole 45370 (Poland); Shpotyuk, M. [Institute of Materials of SRC “Carat”, 212 Stryjska Str., Lviv 79031 (Ukraine); Lviv Polytechnic National University, 12 Bandery Str., Lviv 79013 (Ukraine); Filipecki, J. [Institute of Physics of Jan Dlugosz University, 13/15 al. Armii Krajowej, Czestcochowa 42200 (Poland)
2014-11-01
Highlights: • Decisive role of specific chemical environment in free-volume correlations in glass. • Realistic free volumes in As–S/Se glass are defined by newly modified τ{sub 2}-R formula. • Overestimated void sizes in chalcogenide glass as compared with molecular polymers. - Abstract: A newly modified correlation equation between defect-related positron lifetime determined within two-state trapping model and radius of corresponding free-volume-type defects was proposed to describe compositional variations in atomic-deficient structure of covalent-bonded chalcogenides like binary As–S/Se glasses. Specific chemical environment of free-volume voids around neighboring network-forming polyhedrons was shown to play a decisive role in this correlation, leading to systematically enhanced volumes in comparison with typical molecular substrates, such as polymers.
Correlations between entropy and volume of melting in halide salts
International Nuclear Information System (INIS)
Akdeniz, Z.; Tosi, M.P.
1991-09-01
Melting parameters and transport coefficients in the melt are collated for halides of monovalent, divalent and trivalent metals. A number of systems show a deficit of entropy of melting relative to the linear relationships between entropy change and relative volume change on melting that are found to be approximately obeyed by a majority of halides. These behaviours are discussed on the basis of structural and transport data. The deviating systems are classified into three main classes, namely (i) fast-ion conductors in the high-temperature crystal phase such as AgI, (ii) strongly structured network-like systems such as ZnCl 2 , and (iii) molecular systems melting into associated molecular liquids such as SbCl 3 . (author). 35 refs, 1 fig., 3 tabs
Quaternion analyticity and conformally Kaehlerian structure in Euclidean gravity
International Nuclear Information System (INIS)
Guersey, F.; Chia-Hsiung Tze
1984-01-01
Starting from the fact that the d = 4 Euclidean flat spacetime is conformally related to the Kaehler manifold H 2 xS 2 , we show the Euclidean Schwarzschild metric to be conformally related to another Kaehler manifold M 2 xS 2 with M 2 being conformal to H 2 in two dimensions. Both metrics which are conformally Kaehlerian, are form-invariant under the infinite parameter Fueter group, the Euclidean counterpart of Milne's group of clock regraduation. The associated Einstein's equations translate into Fueter's quaternionic analyticity. The latter leads to an infinite number of local continuity equations. (orig.)
Assessment of correlation between knee notch width index and the three-dimensional notch volume
van Eck, C.F.; Martins, C.A.Q.; Lorenz, S.G.F.; Fu, F.H.; Smolinski, P.
2010-01-01
This study was done to determine whether there is a correlation between the notch volume and the notch width index (NWI) as measured on the three most frequently used radiographic views: the Holmblad 45A degrees, Holmblad 70A degrees, and Rosenberg view. The notch volume of 20 cadaveric knees was
Local Volume Hi Survey: the far-infrared radio correlation
Shao, Li; Koribalski, Bärbel S.; Wang, Jing; Ho, Luis C.; Staveley-Smith, Lister
2018-06-01
In this paper we measure the far-infrared (FIR) and radio flux densities of a sample of 82 local gas-rich galaxies, including 70 "dwarf" galaxies (M* correlation (FRC) over four orders of magnitude (F_1.4GHz ∝ F_FIR^{1.00± 0.08}). However, for detected galaxies only, a trend of larger FIR-to-radio ratio with decreasing flux density is observed. We estimate the star formation rate by combining UV and mid-IR data using empirical calibration. It is confirmed that both FIR and radio emission are strongly connected with star formation but with significant non-linearity. Dwarf galaxies are found radiation deficient in both bands, when normalized by star formation rate. It urges a "conspiracy" to keep the FIR-to-radio ratio generally constant. By using partial correlation coefficient in Pearson definition, we identify the key galaxy properties associated with the FIR and radio deficiency. Some major factors, such as stellar mass surface density, will cancel out when taking the ratio between FIR and radio fluxes. The remaining factors, such as HI-to-stellar mass ratio and galaxy size, are expected to cancel each other due to the distribution of galaxies in the parameter space. Such cancellation is probably responsible for the "conspiracy" to keep the FRC alive.
New solutions of euclidean SU(2) gauge theory
International Nuclear Information System (INIS)
Khan, I.
1983-08-01
New solutions of the Euclidean SU(2) gauge theory having finite field strength everywhere are presented. The solutions are self dual or antidual and constitute a two-parameter family which includes the instantons. (author)
PERBANDINGAN EUCLIDEAN DISTANCE DENGAN CANBERRA DISTANCE PADA FACE RECOGNITION
Directory of Open Access Journals (Sweden)
Sendhy Rachmat Wurdianarto
2014-08-01
Full Text Available Perkembangan ilmu pada dunia komputer sangatlah pesat. Salah satu yang menandai hal ini adalah ilmu komputer telah merambah pada dunia biometrik. Arti biometrik sendiri adalah karakter-karakter manusia yang dapat digunakan untuk membedakan antara orang yang satu dengan yang lainnya. Salah satu pemanfaatan karakter / organ tubuh pada setiap manusia yang digunakan untuk identifikasi (pengenalan adalah dengan memanfaatkan wajah. Dari permasalahan diatas dalam pengenalan lebih tentang aplikasi Matlab pada Face Recognation menggunakan metode Euclidean Distance dan Canberra Distance. Model pengembangan aplikasi yang digunakan adalah model waterfall. Model waterfall beriisi rangkaian aktivitas proses yang disajikan dalam proses analisa kebutuhan, desain menggunakan UML (Unified Modeling Language, inputan objek gambar diproses menggunakan Euclidean Distance dan Canberra Distance. Kesimpulan yang dapat ditarik adalah aplikasi face Recognation menggunakan metode euclidean Distance dan Canverra Distance terdapat kelebihan dan kekurangan masing-masing. Untuk kedepannya aplikasi tersebut dapat dikembangkan dengan menggunakan objek berupa video ataupun objek lainnya. Kata kunci : Euclidean Distance, Face Recognition, Biometrik, Canberra Distance
On the invariant theory of Weingarten surfaces in Euclidean space
International Nuclear Information System (INIS)
Ganchev, Georgi; Mihova, Vesselka
2010-01-01
On any Weingarten surface in Euclidean space (strongly regular or rotational), we introduce locally geometric principal parameters and prove that such a surface is determined uniquely up to a motion by a special invariant function, which satisfies a natural nonlinear partial differential equation. This result can be interpreted as a solution to the Lund-Regge reduction problem for Weingarten surfaces in Euclidean space. We apply this theory to fractional-linear Weingarten surfaces and obtain the nonlinear partial differential equations describing them.
Killgore, William D. S.; Olson, Elizabeth A.; Weber, Mareen
2013-12-01
Physical activity facilitates neurogenesis of dentate cells in the rodent hippocampus, a brain region critical for memory formation and spatial representation. Recent findings in humans also suggest that aerobic exercise can lead to increased hippocampal volume and enhanced cognitive functioning in children and elderly adults. However, the association between physical activity and hippocampal volume during the period from early adulthood through middle age has not been effectively explored. Here, we correlated the number of minutes of self-reported exercise per week with gray matter volume of the hippocampus using voxel-based morphometry (VBM) in 61 healthy adults ranging from 18 to 45 years of age. After controlling for age, gender, and total brain volume, total minutes of weekly exercise correlated significantly with volume of the right hippocampus. Findings highlight the relationship between regular physical exercise and brain structure during early to middle adulthood.
MARS CODE MANUAL VOLUME V: Models and Correlations
International Nuclear Information System (INIS)
Chung, Bub Dong; Bae, Sung Won; Lee, Seung Wook; Yoon, Churl; Hwang, Moon Kyu; Kim, Kyung Doo; Jeong, Jae Jun
2010-02-01
Korea Advanced Energy Research Institute (KAERI) conceived and started the development of MARS code with the main objective of producing a state-of-the-art realistic thermal hydraulic systems analysis code with multi-dimensional analysis capability. MARS achieves this objective by very tightly integrating the one dimensional RELAP5/MOD3 with the multi-dimensional COBRA-TF codes. The method of integration of the two codes is based on the dynamic link library techniques, and the system pressure equation matrices of both codes are implicitly integrated and solved simultaneously. In addition, the Equation-Of-State (EOS) for the light water was unified by replacing the EOS of COBRA-TF by that of the RELAP5. This models and correlations manual provides a complete list of detailed information of the thermal-hydraulic models used in MARS, so that this report would be very useful for the code users. The overall structure of the manual is modeled on the structure of the RELAP5 and as such the layout of the manual is very similar to that of the RELAP. This similitude to RELAP5 input is intentional as this input scheme will allow minimum modification between the inputs of RELAP5 and MARS3.1. MARS3.1 development team would like to express its appreciation to the RELAP5 Development Team and the USNRC for making this manual possible
Absence of even-integer ζ-function values in Euclidean physical quantities in QCD
Jamin, Matthias; Miravitllas, Ramon
2018-04-01
At order αs4 in perturbative quantum chromodynamics, even-integer ζ-function values are present in Euclidean physical correlation functions like the scalar quark correlation function or the scalar gluonium correlator. We demonstrate that these contributions cancel when the perturbative expansion is expressed in terms of the so-called C-scheme coupling αˆs which has recently been introduced in Ref. [1]. It is furthermore conjectured that a ζ4 term should arise in the Adler function at order αs5 in the MS ‾-scheme, and that this term is expected to disappear in the C-scheme as well.
Statistical 2D and 3D shape analysis using Non-Euclidean Metrics
DEFF Research Database (Denmark)
Larsen, Rasmus; Hilger, Klaus Baggesen; Wrobel, Mark Christoph
2002-01-01
We address the problem of extracting meaningful, uncorrelated biological modes of variation from tangent space shape coordinates in 2D and 3D using non-Euclidean metrics. We adapt the maximum autocorrelation factor analysis and the minimum noise fraction transform to shape decomposition. Furtherm......We address the problem of extracting meaningful, uncorrelated biological modes of variation from tangent space shape coordinates in 2D and 3D using non-Euclidean metrics. We adapt the maximum autocorrelation factor analysis and the minimum noise fraction transform to shape decomposition....... Furthermore, we study metrics based on repated annotations of a training set. We define a way of assessing the correlation between landmarks contrary to landmark coordinates. Finally, we apply the proposed methods to a 2D data set consisting of outlines of lungs and a 3D/(4D) data set consisting of sets...
Structure functions at small xBj in a Euclidean field theory approach
International Nuclear Information System (INIS)
Hebecker, A.; Meggiolaro, E.; Nachtmann, O.
2000-01-01
The small-x Bj limit of deep inelastic scattering is related to the high-energy limit of the forward Compton amplitude in a familiar way. We show that the analytic continuation of this amplitude in the energy variable is calculable from a matrix element in Euclidean field theory. This matrix element can be written as a Euclidean functional integral in an effective field theory. Its effective Lagrangian has a simple expression in terms of the original Lagrangian. The functional integral expression obtained can, at least in principle, be evaluated using genuinely non-perturbative methods, e.g., on the lattice. Thus, a fundamentally new approach to the long-standing problem of structure functions at very small x Bj seems possible. We give arguments that the limit x Bj →0 corresponds to a critical point of the effective field theory where the correlation length becomes infinite in one direction
Rhein, Cosima; Mühle, Christiane; Richter-Schmidinger, Tanja; Alexopoulos, Panagiotis; Doerfler, Arnd; Kornhuber, Johannes
2014-01-01
In neuropsychiatric diseases with basal ganglia involvement, higher cognitive functions are often impaired. In this exploratory study, we examined healthy young adults to gain detailed insight into the relationship between basal ganglia volume and cognitive abilities under non-pathological conditions. We investigated 137 healthy adults that were between the ages of 21 and 35 years with similar educational backgrounds. Magnetic resonance imaging (MRI) was performed, and volumes of basal ganglia nuclei in both hemispheres were calculated using FreeSurfer software. The cognitive assessment consisted of verbal, numeric and figural aspects of intelligence for either the fluid or the crystallised intelligence factor using the intelligence test Intelligenz-Struktur-Test (I-S-T 2000 R). Our data revealed significant correlations of the caudate nucleus and pallidum volumes with figural and numeric aspects of intelligence, but not with verbal intelligence. Interestingly, figural intelligence associations were dependent on sex and intelligence factor; in females, the pallidum volumes were correlated with crystallised figural intelligence (r = 0.372, p = 0.01), whereas in males, the caudate volumes were correlated with fluid figural intelligence (r = 0.507, p = 0.01). Numeric intelligence was correlated with right-lateralised caudate nucleus volumes for both females and males, but only for crystallised intelligence (r = 0.306, p = 0.04 and r = 0.459, p = 0.04, respectively). The associations were not mediated by prefrontal cortical subfield volumes when controlling with partial correlation analyses. The findings of our exploratory analysis indicate that figural and numeric intelligence aspects, but not verbal aspects, are strongly associated with basal ganglia volumes. Unlike numeric intelligence, the type of figural intelligence appears to be related to distinct basal ganglia nuclei in a sex-specific manner. Subcortical brain structures thus may contribute substantially to
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Lee, Hong Seok; Choi, Doo Ho; Park, Hee Chul; Park, Won; Yu, Jeong Il; Chung, Kwang Zoo [Dept. of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)
2016-09-15
To determine whether large rectal volume on planning computed tomography (CT) results in lower tumor regression grade (TRG) after neoadjuvant concurrent chemoradiotherapy (CCRT) in rectal cancer patients. We reviewed medical records of 113 patients treated with surgery following neoadjuvant CCRT for rectal cancer between January and December 2012. Rectal volume was contoured on axial images in which gross tumor volume was included. Average axial rectal area (ARA) was defined as rectal volume divided by longitudinal tumor length. The impact of rectal volume and ARA on TRG was assessed. Average rectal volume and ARA were 11.3 mL and 2.9 cm². After completion of neoadjuvant CCRT in 113 patients, pathologic results revealed total regression (TRG 4) in 28 patients (25%), good regression (TRG 3) in 25 patients (22%), moderate regression (TRG 2) in 34 patients (30%), minor regression (TRG 1) in 24 patients (21%), and no regression (TRG0) in 2 patients (2%). No difference of rectal volume and ARA was found between each TRG groups. Linear correlation existed between rectal volume and TRG (p = 0.036) but not between ARA and TRG (p = 0.058). Rectal volume on planning CT has no significance on TRG in patients receiving neoadjuvant CCRT for rectal cancer. These results indicate that maintaining minimal rectal volume before each treatment may not be necessary.
International Nuclear Information System (INIS)
Lee, Hong Seok; Choi, Doo Ho; Park, Hee Chul; Park, Won; Yu, Jeong Il; Chung, Kwang Zoo
2016-01-01
To determine whether large rectal volume on planning computed tomography (CT) results in lower tumor regression grade (TRG) after neoadjuvant concurrent chemoradiotherapy (CCRT) in rectal cancer patients. We reviewed medical records of 113 patients treated with surgery following neoadjuvant CCRT for rectal cancer between January and December 2012. Rectal volume was contoured on axial images in which gross tumor volume was included. Average axial rectal area (ARA) was defined as rectal volume divided by longitudinal tumor length. The impact of rectal volume and ARA on TRG was assessed. Average rectal volume and ARA were 11.3 mL and 2.9 cm². After completion of neoadjuvant CCRT in 113 patients, pathologic results revealed total regression (TRG 4) in 28 patients (25%), good regression (TRG 3) in 25 patients (22%), moderate regression (TRG 2) in 34 patients (30%), minor regression (TRG 1) in 24 patients (21%), and no regression (TRG0) in 2 patients (2%). No difference of rectal volume and ARA was found between each TRG groups. Linear correlation existed between rectal volume and TRG (p = 0.036) but not between ARA and TRG (p = 0.058). Rectal volume on planning CT has no significance on TRG in patients receiving neoadjuvant CCRT for rectal cancer. These results indicate that maintaining minimal rectal volume before each treatment may not be necessary
Pulmonary function tests correlated with thoracic volumes in adolescent idiopathic scoliosis.
Ledonio, Charles Gerald T; Rosenstein, Benjamin E; Johnston, Charles E; Regelmann, Warren E; Nuckley, David J; Polly, David W
2017-01-01
Scoliosis deformity has been linked with deleterious changes in the thoracic cavity that affect pulmonary function. The causal relationship between spinal deformity and pulmonary function has yet to be fully defined. It has been hypothesized that deformity correction improves pulmonary function by restoring both respiratory muscle efficiency and increasing the space available to the lungs. This research aims to correlate pulmonary function and thoracic volume before and after scoliosis correction. Retrospective correlational analysis between thoracic volume modeling from plain x-rays and pulmonary function tests was conducted. Adolescent idiopathic scoliosis patients enrolled in a multicenter database were sorted by pre-operative Total Lung Capacities (TLC) % predicted values from their Pulmonary Function Tests (PFT). Ten patients with the best and ten patients with the worst TLC values were included. Modeled thoracic volume and TLC values were compared before and 2 years after surgery. Scoliosis correction resulted in an increase in the thoracic volume for patients with the worst initial TLCs (11.7%) and those with the best initial TLCs (12.5%). The adolescents with the most severe pulmonary restriction prior to surgery strongly correlated with post-operative change in total lung capacity and thoracic volume (r 2 = 0.839; p volume in this group was 373.1 cm 3 (11.7%) which correlated with a 21.2% improvement in TLC. Scoliosis correction in adolescents was found to increase thoracic volume and is strongly correlated with improved TLC in cases with severe restrictive pulmonary function, but no correlation was found in cases with normal pulmonary function. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:175-182, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.
International Nuclear Information System (INIS)
Catoni, Francesco; Cannata, Roberto; Zampetti, Paolo
2005-08-01
The Riemann and Lorentz constant curvature surfaces are investigated from an Euclidean point of view. The four surfaces (constant positive and constant negative curvatures with definite and non-definite fine elements) are represented as surfaces in a Riemannian or in a particular semi-Riemannian flat space and it is shown that the complex and the hyperbolic numbers allow to obtain the same equations for the corresponding Riemann and Lorentz surfaces, respectively. Moreover it is shown that the geodesics on the Lorentz surfaces states, from a physical point of view, a link between curvature and fields. This result is obtained just as a consequence of the space-time geometrical symmetry, without invoking the famous Einstein general relativity postulate [it
Does Height to Width Ratio Correlate with Mean Volume in Gastropods?
Barriga, R.; Seixas, G.; Payne, J.
2012-12-01
Marine organisms' shell shape and size show important biological information. For example, shape and size can dictate how the organism ranges for food and escapes predation. Due to lack of data and analysis, the evolution of shell size in marine gastropods (snails) remains poorly known. In this study, I attempt to find the relationship between height to width ratio and mean volume. I collected height and width measurements from primary literature sources and calculated volume from these measurements. My results indicate that there was no correlation between height to width ratio and mean volume between 500 to 200 Ma, but there was a correlation between 200 Ma to present where there is a steady increase in both height to width ratio and mean volume. This means that shell shape was not an important factor at the beginning of gastropod evolution but after 200 Ma body size evolution was increasingly driven by the height to width ratio.
Dhikav, Vikas; Duraiswamy, Sharmila; Anand, Kuljeet Singh
2017-01-01
Introduction: Hippocampus undergoes atrophy in patients with Alzheimer's disease (AD). Calculation of hippocampal volumes can be done by a variety of methods using T1-weighted images of magnetic resonance imaging (MRI) of the brain. Medial temporal lobes atrophy (MTL) can be rated visually using T1-weighted MRI brain images. The present study was done to see if any correlation existed between hippocampal volumes and visual rating scores of the MTL using Scheltens Visual Rating Method. Materia...
Directory of Open Access Journals (Sweden)
Xiaojun Huang
2017-11-01
Full Text Available BackgroundDelusional thinking is one of the hallmark symptoms of schizophrenia. However, the underlying neural substrate for delusions in schizophrenia remains unknown. In an attempt to further our understanding of the neural basis of delusions, we explored gray matter deficits and their clinical associations in first-episode schizophrenia patients with and without delusions.MethodsTwenty-four first-episode schizophrenia patients with delusions and 18 without delusions as well as 26 healthy controls (HC underwent clinical assessment and whole-brain structural imaging which were acquired a 3.0 T scanner. Voxel-based morphometry was used to explore inter-group differences in gray matter volume using analysis of covariance, and Spearman correlation coefficients (rho between the Scale for the Assessment of Positive Symptoms (SAPS-delusion scores and mean regional brain volumes was obtained.ResultsPatients with delusions showed decreased brain gray matter volumes in the left putamen, thalamus, and caudate regions compared with HC. Patients with delusions also showed decreased regional volume in the left putamen and thalamus compared with patients without delusions. SAPS-delusion scores were negatively correlated with the gray matter volumes of the left putamen and thalamus.DiscussionLeft putamen and thalamus volume loss may be biological correlates of delusions in schizophrenia.
Correlated volume-energy fluctuations of phospholipid membranes: A simulation study
DEFF Research Database (Denmark)
Pedersen, Ulf. R.; Peters, Günther H.J.; Schröder, Thomas B.
2010-01-01
This paper reports all-atom computer simulations of five phospholipid membranes (DMPC, DPPC, DMPG, DMPS, and DMPSH) with focus on the thermal equilibrium fluctuations of volume, energy, area, thickness, and chain order. At constant temperature and pressure, volume and energy exhibit strong...... membranes, showing a similar picture. The cause of the observed strong correlations is identified by splitting volume and energy into contributions from tails, heads, and water, and showing that the slow volume−energy fluctuations derive from van der Waals interactions of the tail region; they are thus...
Morphology and function: MR pineal volume and melatonin level in human saliva are correlated.
Liebrich, Luisa-Sophie; Schredl, Michael; Findeisen, Peter; Groden, Christoph; Bumb, Jan Malte; Nölte, Ingo S
2014-10-01
To investigate the relation between circadian saliva melatonin levels and pineal volume as determined by MRI. Plasma melatonin levels follow a circadian rhythm with a high interindividual variability. In 103 healthy individuals saliva melatonin levels were determined at four time points within 24 h and MRI was performed once (3.0 Tesla, including three-dimensional T2 turbo spin echo [3D-T2-TSE], susceptibility-weighted imaging [SWI]). Pineal volume as well as cyst volume were assessed from multiplanar reconstructed 3D-T2-TSE images. Pineal calcification volume tissue was determined on SWI. To correct for hormonal inactive pineal tissue, cystic and calcified areas were excluded. Sleep quality was assessed with the Landeck Inventory for sleep quality disturbance. Solid and uncalcified pineal volume correlated to melatonin maximum (r = 0.28; P < 0.05) and area under the curve (r = 0.29; P < 0.05). Of interest, solid and uncalcified pineal volume correlated negatively with the sleep rhythm disturbances subscore (r = -0.17; P < 0.05) despite a very homogenous population. Uncalcified solid pineal tissue measured by 3D-T2-TSE and SWI is related to human saliva melatonin levels. The analysis of the sleep quality and pineal volume suggests a linkage between better sleep quality and hormonal active pineal tissue. © 2013 Wiley Periodicals, Inc.
Flexible intuitions of Euclidean geometry in an Amazonian indigene group
Izard, Véronique; Pica, Pierre; Spelke, Elizabeth S.; Dehaene, Stanislas
2011-01-01
Kant argued that Euclidean geometry is synthesized on the basis of an a priori intuition of space. This proposal inspired much behavioral research probing whether spatial navigation in humans and animals conforms to the predictions of Euclidean geometry. However, Euclidean geometry also includes concepts that transcend the perceptible, such as objects that are infinitely small or infinitely large, or statements of necessity and impossibility. We tested the hypothesis that certain aspects of nonperceptible Euclidian geometry map onto intuitions of space that are present in all humans, even in the absence of formal mathematical education. Our tests probed intuitions of points, lines, and surfaces in participants from an indigene group in the Amazon, the Mundurucu, as well as adults and age-matched children controls from the United States and France and younger US children without education in geometry. The responses of Mundurucu adults and children converged with that of mathematically educated adults and children and revealed an intuitive understanding of essential properties of Euclidean geometry. For instance, on a surface described to them as perfectly planar, the Mundurucu's estimations of the internal angles of triangles added up to ∼180 degrees, and when asked explicitly, they stated that there exists one single parallel line to any given line through a given point. These intuitions were also partially in place in the group of younger US participants. We conclude that, during childhood, humans develop geometrical intuitions that spontaneously accord with the principles of Euclidean geometry, even in the absence of training in mathematics. PMID:21606377
Diffusion tensor imaging correlates with lesion volume in cerebral hemisphere infarctions
International Nuclear Information System (INIS)
Rossi, Maija E; Jason, Eeva; Marchesotti, Silvia; Dastidar, Prasun; Ollikainen, Jyrki; Soimakallio, Seppo
2010-01-01
Both a large lesion volume and abnormalities in diffusion tensor imaging are independently associated with a poor prognosis after cerebral infarctions. Therefore, we assume that they are associated. This study assessed the associations between lesion volumes and diffusion tensor imaging in patients with a right-sided cerebral infarction. The lesion volumes of 33 patients (age 65.9 ± 8.7, 26 males and 7 females) were imaged using computed tomography (CT) in the acute phase (within 3-4 hours) and magnetic resonance imaging (MRI) in the chronic phase (follow-up at 12 months, with a range of 8-27 months). The chronic-phase fractional anisotropy (FA) and mean diffusivity (MD) values were measured at the site of the infarct and selected white matter tracts. Neurological tests in both the acute and chronic phases, and DTI lateralization were assessed with the Wilcoxon signed-rank test. The effects of thrombolytic therapy (n = 10) were assessed with the Mann-Whitney U test. The correlations between the measured parameters were analysed with Spearman's rho correlation. Bonferroni post-hoc correction was used to compensate for the familywise error rate in multiple comparisons. Several MD values in the right hemisphere correlated positively and FA values negatively with the lesion volumes. These correlations included both lesion area and healthy tissue. The results of the mini-mental state examination and the National Institutes of Health Stroke Scale also correlated with the lesion volume. A larger infarct volume is associated with more pronounced tissue modifications in the chronic stage as observed with the MD and FA alterations
RELAP5/MOD3 code manual. Volume 4, Models and correlations
International Nuclear Information System (INIS)
1995-08-01
The RELAP5 code has been developed for best-estimate transient simulation of light water reactor coolant systems during postulated accidents. The code models the coupled behavior of the reactor coolant system and the core for loss-of-coolant accidents and operational transients such as anticipated transient without scram, loss of offsite power, loss of feedwater, and loss of flow. A generic modeling approach is used that permits simulating a variety of thermal hydraulic systems. Control system and secondary system components are included to permit modeling of plant controls, turbines, condensers, and secondary feedwater systems. RELAP5/MOD3 code documentation is divided into seven volumes: Volume I presents modeling theory and associated numerical schemes; Volume II details instructions for code application and input data preparation; Volume III presents the results of developmental assessment cases that demonstrate and verify the models used in the code; Volume IV discusses in detail RELAP5 models and correlations; Volume V presents guidelines that have evolved over the past several years through the use of the RELAP5 code; Volume VI discusses the numerical scheme used in RELAP5; and Volume VII presents a collection of independent assessment calculations
Some nonunitary, indecomposable representations of the Euclidean algebra e(3)
International Nuclear Information System (INIS)
Douglas, Andrew; De Guise, Hubert
2010-01-01
The Euclidean group E(3) is the noncompact, semidirect product group E(3)≅R 3 x SO(3). It is the Lie group of orientation-preserving isometries of three-dimensional Euclidean space. The Euclidean algebra e(3) is the complexification of the Lie algebra of E(3). We construct three distinct families of finite-dimensional, nonunitary representations of e(3) and show that each representation is indecomposable. The representations of the first family are explicitly realized as subspaces of the polynomial ring F[X,Y,Z] with the action of e(3) given by differential operators. The other families are constructed via duals and tensor products of the representations within the first family. We describe subrepresentations, quotients and duals of these indecomposable representations.
Directory of Open Access Journals (Sweden)
Izumi Matsudaira
Full Text Available A positive parenting style affects psychological and cognitive development in children. Neuroimaging studies revealed that a positive parenting style influenced brain structure in children. Parental praise is a concrete behavior observed in positive parenting. Although previous psychological studies revealed a positive effect of parental praise on children, little is known about the relationship between parental praise and brain structure in children. Thus, the purpose of the present study was to determine whether there was a correlation between the parental attitude towards praising their child and gray matter volume in the children (116 boys and 109 girls; mean age, 10.6 years old. We examined the correlation between regional gray matter volume and parental praise using voxel-based morphometry (VBM following magnetic resonance imaging (MRI. In addition, to confirm the positive effects of parental praise, we analyzed the correlation between the frequency of parental praise and personality traits in children. We showed that the parental attitude towards praising their child was significantly and positively correlated with the gray matter volume of the left posterior insular cortex in children. Moreover, we found a significant positive correlation between parental attitude towards praising their child and the personality traits of conscientiousness and openness to experience in the children. Prior studies said that gray matter volume in the posterior insula was correlated with empathy, and the functional connectivity between this area and the amygdala was associated with emotional regulation. Furthermore, the posterior insula relates to auditory function, and therefore, was likely involved in the processing of parental praise. Considering the possibility of experience-dependent plasticity, frequent parental praise would lead to increased posterior insular gray matter volume in children. Our study is the first to elucidate the relationship between
Incidence of radiation pneumonitis after thoracic irradiation: Dose-volume correlates
International Nuclear Information System (INIS)
Schallenkamp, John M.; Miller, Robert C.; Brinkmann, Debra H.; Foote, Tyler; Garces, Yolanda I.
2007-01-01
Purpose: To define clinical and dosimetric parameters correlated with the risk of clinically relevant radiation pneumonitis (RP) after thoracic radiotherapy. Methods and Materials: Records of consecutive patients treated with definitive thoracic radiotherapy were retrospectively reviewed for the incidence of RP of Grade 2 or greater by the Common Toxicity Criteria. Dose-volume histograms using total lung volume (TL) and TL minus gross tumor volume (TL-G) were created with and without heterogeneity corrections. Mean lung dose (MLD), effective lung volume (V eff ), and percentage of TL or TL-G receiving greater than or equal to 10, 13, 15, 20, and 30 Gy (V10-V30, respectively) were analyzed by logistic regression. Receiver operating characteristic (ROC) curves were generated to estimate RP predictive values. Results: Twelve cases of RP were identified in 92 eligible patients. Mean lung dose, V10, V13, V15, V20, and V eff were significantly correlated to RP. Combinations of MLD, V eff , V20, and V30 lost significance using TL-G and heterogeneity corrections. Receiver operating characteristic analysis determined V10 and V13 as the best predictors of RP risk, with a decrease in predictive value above those volumes. Conclusions: Intrathoracic radiotherapy should be planned with caution when using radiotherapy techniques delivering doses of 10 to 15 Gy to large lung volumes
What if? Exploring the multiverse through Euclidean wormholes
Bouhmadi-López, Mariam; Krämer, Manuel; Morais, João; Robles-Pérez, Salvador
2017-10-01
We present Euclidean wormhole solutions describing possible bridges within the multiverse. The study is carried out in the framework of third quantisation. The matter content is modelled through a scalar field which supports the existence of a whole collection of universes. The instanton solutions describe Euclidean solutions that connect baby universes with asymptotically de Sitter universes. We compute the tunnelling probability of these processes. Considering the current bounds on the energy scale of inflation and assuming that all the baby universes are nucleated with the same probability, we draw some conclusions about which universes are more likely to tunnel and therefore undergo a standard inflationary era.
What if? Exploring the multiverse through Euclidean wormholes
International Nuclear Information System (INIS)
Bouhmadi-Lopez, Mariam; Kraemer, Manuel; Morais, Joao; Robles-Perez, Salvador
2017-01-01
We present Euclidean wormhole solutions describing possible bridges within the multiverse. The study is carried out in the framework of third quantisation. The matter content is modelled through a scalar field which supports the existence of a whole collection of universes. The instanton solutions describe Euclidean solutions that connect baby universes with asymptotically de Sitter universes. We compute the tunnelling probability of these processes. Considering the current bounds on the energy scale of inflation and assuming that all the baby universes are nucleated with the same probability, we draw some conclusions about which universes are more likely to tunnel and therefore undergo a standard inflationary era. (orig.)
What if? Exploring the multiverse through Euclidean wormholes
Energy Technology Data Exchange (ETDEWEB)
Bouhmadi-Lopez, Mariam [University of the Basque Country UPV/EHU, Department of Theoretical Physics, Bilbao (Spain); Ikerbasque, Basque Foundation for Science, Bilbao (Spain); Kraemer, Manuel [University of Szczecin, Institute of Physics, Szczecin (Poland); Morais, Joao [University of the Basque Country UPV/EHU, Department of Theoretical Physics, Bilbao (Spain); Robles-Perez, Salvador [Instituto de Fisica Fundamental, CSIC, Madrid (Spain); Estacion Ecologica de Biocosmologia, Medellin (Spain)
2017-10-15
We present Euclidean wormhole solutions describing possible bridges within the multiverse. The study is carried out in the framework of third quantisation. The matter content is modelled through a scalar field which supports the existence of a whole collection of universes. The instanton solutions describe Euclidean solutions that connect baby universes with asymptotically de Sitter universes. We compute the tunnelling probability of these processes. Considering the current bounds on the energy scale of inflation and assuming that all the baby universes are nucleated with the same probability, we draw some conclusions about which universes are more likely to tunnel and therefore undergo a standard inflationary era. (orig.)
Cosmetic surgery volume and its correlation with the major US stock market indices.
Gordon, Chad R; Pryor, Landon; Afifi, Ahmed M; Benedetto, Paul X; Langevin, C J; Papay, Francis; Yetman, Randall; Zins, James E
2010-01-01
As a consumer-driven industry, cosmetic plastic surgery is subject to ebbs and flows as the economy changes. There have been many predictions about the short, intermediate, and long-term impact on cosmetic plastic surgery as a result of difficulties in the current economic climate, but no studies published in the literature have quantified a direct correlation. The authors investigate a possible correlation between cosmetic surgery volume and the economic trends of the three major US stock market indices. A volume analysis for the time period from January 1992 to October 2008 was performed (n = 7360 patients, n = 8205 procedures). Four cosmetic procedures-forehead lift (FL), rhytidectomy (Rh), breast augmentation (BA), and liposuction (Li)-were chosen; breast reduction (BRd), breast reconstruction (BRc), and carpal tunnel release (CTR) were selected for comparison. Case volumes for each procedure and fiscal quarter were compared to the trends of the S&P 500, Dow Jones (DOW), and NASDAQ (NASD) indices. Pearson correlation statistics were used to evaluate a relationship between the market index trends and surgical volume. P values indices. FL (n =312) only correlated to the NASD (P = .021) and did not reach significance with the S&P 500 (P = .077) or DOW (P = .14). BRd and BRc demonstrated a direct correlation to two of the three stock market indices, whereas CTR showed an inverse (ie, negative) correlation to two of the three indices. This study, to our knowledge, is the first to suggest a direct correlation of four cosmetic and two reconstructive plastic surgery procedures to the three major US stock market indices and further emphasizes the importance of a broad-based plastic surgery practice in times of economic recession.
Tam, Roger C; Traboulsee, Anthony; Riddehough, Andrew; Li, David K B
2012-01-01
The change in T 1-hypointense lesion ("black hole") volume is an important marker of pathological progression in multiple sclerosis (MS). Black hole boundaries often have low contrast and are difficult to determine accurately and most (semi-)automated segmentation methods first compute the T 2-hyperintense lesions, which are a superset of the black holes and are typically more distinct, to form a search space for the T 1w lesions. Two main potential sources of measurement noise in longitudinal black hole volume computation are partial volume and variability in the T 2w lesion segmentation. A paired analysis approach is proposed herein that uses registration to equalize partial volume and lesion mask processing to combine T 2w lesion segmentations across time. The scans of 247 MS patients are used to compare a selected black hole computation method with an enhanced version incorporating paired analysis, using rank correlation to a clinical variable (MS functional composite) as the primary outcome measure. The comparison is done at nine different levels of intensity as a previous study suggests that darker black holes may yield stronger correlations. The results demonstrate that paired analysis can strongly improve longitudinal correlation (from -0.148 to -0.303 in this sample) and may produce segmentations that are more sensitive to clinically relevant changes.
What does the Euclidean pseudoparticle do in Minkowski space
International Nuclear Information System (INIS)
Ju, I.
1978-08-01
Self dual pseudoparticle solutions for the classical Yang--Mills field equation with finite action have been constructed in Minkowski space. It is shown that the topological structures apparent in Euclidean space are no longer present in Minkowski space. Topological charges become fractional leading to the unquantized axial charge violation in the process involving fermions. 17 references
Euclidean self-dual Yang-Mills field configurations
International Nuclear Information System (INIS)
Sartori, G.
1980-01-01
The determination of a large class of regular and singular Euclidean self-dual Yang-Mills field configurations is reduced to the solution of a set of linear algebraic equations. The matrix of the coefficients is a polynomial functions of x and the rules for its construction are elementary. (author)
The toroidal Hausdorff dimension of 2d Euclidean quantum gravity
DEFF Research Database (Denmark)
Ambjorn, Jan; Budd, Timothy George
2013-01-01
The lengths of shortest non-contractible loops are studied numerically in 2d Euclidean quantum gravity on a torus coupled to conformal field theories with central charge less than one. We find that the distribution of these geodesic lengths displays a scaling in agreement with a Hausdorff dimension...
Algebraic Methods for Counting Euclidean Embeddings of Rigid Graphs
I.Z. Emiris; E.P. Tsigaridas; A. Varvitsiotis (Antonios); E.R. Gasner
2009-01-01
textabstract The study of (minimally) rigid graphs is motivated by numerous applications, mostly in robotics and bioinformatics. A major open problem concerns the number of embeddings of such graphs, up to rigid motions, in Euclidean space. We capture embeddability by polynomial systems
Timed Fast Exact Euclidean Distance (tFEED) maps
Kehtarnavaz, Nasser; Schouten, Theo E.; Laplante, Philip A.; Kuppens, Harco; van den Broek, Egon
2005-01-01
In image and video analysis, distance maps are frequently used. They provide the (Euclidean) distance (ED) of background pixels to the nearest object pixel. In a naive implementation, each object pixel feeds its (exact) ED to each background pixel; then the minimum of these values denotes the ED to
Optimal Embeddings of Distance Regular Graphs into Euclidean Spaces
F. Vallentin (Frank)
2008-01-01
htmlabstractIn this paper we give a lower bound for the least distortion embedding of a distance regular graph into Euclidean space. We use the lower bound for finding the least distortion for Hamming graphs, Johnson graphs, and all strongly regular graphs. Our technique involves semidefinite
The Euclidean distance degree of an algebraic variety
Draisma, J.; Horobet, E.; Ottaviani, G.; Sturmfels, B.; Thomas, R.R.
2013-01-01
The nearest point map of a real algebraic variety with respect to Euclidean distance is an algebraic function. For instance, for varieties of low rank matrices, the Eckart-Young Theorem states that this map is given by the singular value decomposition. This article develops a theory of such nearest
The Euclidean distance degree of an algebraic variety
Draisma, J.; Horobet, E.; Ottaviani, G.; Sturmfels, B.; Thomas, R.R.
The nearest point map of a real algebraic variety with respect to Euclidean distance is an algebraic function. For instance, for varieties of low-rank matrices, the Eckart–Young Theorem states that this map is given by the singular value decomposition. This article develops a theory of such nearest
Fisher type inequalities for Euclidean t-designs
Delsarte, Ph.; Seidel, J.J.
1989-01-01
The notion of a Euclidean t-design is analyzed in the framework of appropriate inner product spaces of polynomial functions. Some Fisher type inequalities are obtained in a simple manner by this method. The same approach is used to deal with certain analogous combinatorial designs.
Improvement in quality testing of Braille printer output with Euclidean ...
African Journals Online (AJOL)
This paper focuses on quality testing of Braille printed paper using calibrated camera by detecting dots and measuring the Euclidean distances between them with equal gap, vertically and horizontally. For higher accuracy, camera calibration is essential to observe a planar checker board pattern from different distances and ...
The Role of Structure in Learning Non-Euclidean Geometry
Asmuth, Jennifer A.
2009-01-01
How do people learn novel mathematical information that contradicts prior knowledge? The focus of this thesis is the role of structure in the acquisition of knowledge about hyperbolic geometry, a non-Euclidean geometry. In a series of three experiments, I contrast a more holistic structure--training based on closed figures--with a mathematically…
Euclidean Primes Have the Minimum Number of Primitive Roots
Czech Academy of Sciences Publication Activity Database
Křížek, Michal; Somer, L.
2008-01-01
Roč. 12, č. 1 (2008), s. 121-127 ISSN 0972-5555 R&D Projects: GA AV ČR(CZ) IAA100190803 Institutional research plan: CEZ:AV0Z10190503 Keywords : Euclidean primes * Fermat primes * Sophie Germain primes Subject RIV: BA - General Mathematics
Kerschbaumer, Johannes; Bauer, Marlies; Popovscaia, Marina; Grams, Astrid E; Thomé, Claudius; Freyschlag, Christian F
2017-02-01
Surgical resection in combination with radiotherapy in selected cases remains the best option for patients with cerebral metastases. Postoperative relapse of brain metastases occurs frequently and can be reduced by postoperative whole-brain radiotherapy (WBRT). Continuous spread of tumor cells from the primary lesions is debated as a cause of recurrence. It is well known that in gliomas, infiltration takes place within the surrounding edema. Obviously, most brain metastases are usually associated with peritumoral edema, which may act as an indicator of infiltration and more aggressive tumor biology. Therefore, we aimed to investigate the correlation of tumor and edema volumes with overall survival in patients with cerebral metastases. A total of 143 patients diagnosed with brain metastasis (male:female=1.1:1) who underwent surgical resection were included retrospectively in this analysis. Clinical data were retrieved from electronic patient files. The volumes of tumor and edema calculated by manual delineation. The ratio of edema to tumor volume was calculated, leading to dichotomization of the patients. The median tumor volume was 20.1 cc (range=0.8-90.8 cc) and the median volume of edema 49.5 cc (range=0-179.9 cc). The volume of metastases did not significantly correlate with overall survival. The ratio of edema to tumor volume was also not a prognostic factor in terms of overall survival. Only surgical resection, preoperative recursive partitioning analysis class, and postoperative addition of WBRT, as well as female sex, demonstrated beneficial effects. The extent of edema surrounding cerebral metastases does not appear to influence overall survival in patients suffering from brain metastases, although it seems to be responsible for most of the patients' symptoms. The hypothesis that the extent of edema was disadvantageous concerning survival was supported by our data. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios
Chen, B B; Shih, T T F; Hsu, C Y; Yu, C W; Wei, S Y; Chen, C Y; Wu, C H; Chen, C Y
2011-06-01
(1) to correlate thigh muscle volume measured by magnetic resonance image (MRI) with anthropometric measurements and physical function in elderly subjects; (2) to predict MRI-measured thigh muscle volume using anthropometric measurements and physical functional status in elderly subjects. Cross-sectional, nonrandomized study. Outpatient clinic in Taiwan. Sixty-nine elderly subjects (33 men and 36 women) aged 65 and older. The anthropometric data (including body height, body weight, waist size, and thigh circumference), physical activity and function (including grip strength, bilateral quadriceps muscle power, the up and go test, chair rise, and five meters walk time) and bioelectrical impedance analysis data (including total body fat mass, fat-free mass, and predictive muscle size) were measured. MRI-measured muscle volume of both thighs was used as the reference standard. The MRI-measured thigh volume was positively correlated with all anthropometric data, quadriceps muscle power and the up and go test as well as fat-free mass and predictive muscle mass, whereas it was negatively associated with age and walk time. In predicting thigh muscle volume, the variables of age, gender, body weight, and thigh circumference were significant predictors in the linear regression model: Muscle volume (cm3) =4226.3－42.5 × Age (year)－955.7 × gender (male=1, female=2) + 45.9 × body weight(kg) + 60.0 × thigh circumference (cm) (r2 = 0.745, P estimate = 581.6 cm3). The current work provides evidence of a strong relationship between thigh muscle volume and physical function in the elderly. We also developed a prediction equation model using anthropometric measurements. This model is a simple and noninvasive method for everyday clinical practice and follow-up.
The correlation between emotional intelligence and gray matter volume in university students.
Tan, Yafei; Zhang, Qinglin; Li, Wenfu; Wei, Dongtao; Qiao, Lei; Qiu, Jiang; Hitchman, Glenn; Liu, Yijun
2014-11-01
A number of recent studies have investigated the neurological substrates of emotional intelligence (EI), but none of them have considered the neural correlates of EI that are measured using the Schutte Self-Report Emotional Intelligence Scale (SSREIS). This scale was developed based on the EI model of Salovey and Mayer (1990). In the present study, SSREIS was adopted to estimate EI. Meanwhile, magnetic resonance imaging (MRI) and voxel-based morphometry (VBM) were used to evaluate the gray matter volume (GMV) of 328 university students. Results found positive correlations between Monitor of Emotions and VBM measurements in the insula and orbitofrontal cortex. In addition, Utilization of Emotions was positively correlated with the GMV in the parahippocampal gyrus, but was negatively correlated with the VBM measurements in the fusiform gyrus and middle temporal gyrus. Furthermore, Social Ability had volume correlates in the vermis. These findings indicate that the neural correlates of the EI model, which primarily focuses on the abilities of individuals to appraise and express emotions, can also regulate and utilize emotions to solve problems. Copyright © 2014 Elsevier Inc. All rights reserved.
Individual differences in posterior cortical volume correlate with proneness to pride and gratitude.
Zahn, Roland; Garrido, Griselda; Moll, Jorge; Grafman, Jordan
2014-11-01
Proneness to specific moral sentiments (e.g. pride, gratitude, guilt, indignation) has been linked with individual variations in functional MRI (fMRI) response within anterior brain regions whose lesion leads to inappropriate behaviour. However, the role of structural anatomical differences in rendering individuals prone to particular moral sentiments relative to others is unknown. Here, we investigated grey matter volumes (VBM8) and proneness to specific moral sentiments on a well-controlled experimental task in healthy individuals. Individuals with smaller cuneus, and precuneus volumes were more pride-prone, whereas those with larger right inferior temporal volumes experienced gratitude more readily. Although the primary analysis detected no associations with guilt- or indignation-proneness, subgenual cingulate fMRI responses to guilt were negatively correlated with grey matter volumes in the left superior temporal sulcus and anterior dorsolateral prefrontal cortices (right >left). This shows that individual variations in functional activations within critical areas for moral sentiments were not due to grey matter volume differences in the same areas. Grey matter volume differences between healthy individuals may nevertheless play an important role by affecting posterior cortical brain systems that are non-critical but supportive for the experience of specific moral sentiments. This may be of particular relevance when their experience depends on visuo-spatial elaboration. Published by Oxford University Press 2013. This work is written by US Government employees and is in the public domain in the US.
Gomaa, E.; Mostafa, N.; Mohsen, M.; Mohammed, M.
2004-10-01
Positron annihilation lifetime spectroscopy (PALS) was used to study the immiscibility of a polar nitrile rubber (NBR) that had been blended with pure and waste, low- and high-density polyethylene (PE). The effect of the weight percent of the rubber added to the PE was also investigated. It was found that a complicated variation (positive and negative) in both free-volume parameters (τ3 and I 3) from the values of the initial polymers forms an immiscible blend. These results are supported by a significant broadening in the free-volume hole size distributions. This has been interpreted in terms of interfacial spaces created between the boundaries of the two phases. Furthermore, a correlation was established between the free-volume parameters (τ3 and I 3) and the electrical and mechanical properties of the before mentioned polymer blends as a function of the weight percent of waste PE.
Aarnink, R. G.; de la Rosette, J. J.; Huynen, A. L.; Giesen, R. J.; Debruyne, F. M.; Wijkstra, H.
1996-01-01
Standardized estimations of prostate volumes are used for interpretation of prostate specific antigen (PSA) levels. In 243 patients with clinically benign diagnosis, automated and reference prostate volumes and transition zone volumes are correlated to PSA levels. Besides, growth curves of PSA level
Reproducibility of mean nuclear volume and correlation with mean nuclear area in breast cancer
DEFF Research Database (Denmark)
Baak, J P; Ladekarl, M; Sørensen, Flemming Brandt
1994-01-01
reproducible and strongly correlated with nuclear vv assessed in the TOTAL. In invasive breast cancer assessments in the whole tumor section can be used if delineation of the measurement area cannot be done easily. In small areas with a limited number of nuclei (eg, microinvasive parts) MNA can be easier......Previous studies have shown that quantitative, histopathologic features obtained from a carefully selected area in the tumor section ("selective" approach) have a strong prognostic value in breast cancer. On the other hand, it was found that mean nuclear volume estimation in the whole area...... as to their intraobserver and interobserver reproducibility in 22 invasive breast cancer cases. The mean nuclear volume (nuclear vv) was assessed both in the most atypical area (AREA) (selected on morphologic criteria) and in the whole tumor section (TOTAL). Furthermore, the correlation with mean nuclear (profile) area...
Directory of Open Access Journals (Sweden)
Yan-Wei Zhang
2015-01-01
Full Text Available Background: Little attention has been paid to the role of subcortical deep gray matter (SDGM structures in type 2 diabetes mellitus (T2DM-induced cognitive impairment, especially hippocampal subfields. Our aims were to assess the in vivo volumes of SDGM structures and hippocampal subfields using magnetic resonance imaging (MRI and to test their associations with cognitive performance in T2DM. Methods: A total of 80 T2DM patients and 80 neurologically unimpaired healthy controls matched by age, sex and education level was enrolled in this study. We assessed the volumes of the SDGM structures and seven hippocampal subfields on MRI using a novel technique that enabled automated volumetry. We used Mini-Mental State Examination and Montreal Cognitive Assessment (MoCA scores as measures of cognitive performance. The association of glycosylated hemoglobin (HbA1c with SDGM structures and neuropsychological tests and correlations between hippocampal subfields and neuropsychological tests were assessed by partial correlation analysis in T2DM. Results: Bilaterally, the hippocampal volumes were smaller in T2DM patients, mainly in the CA1 and subiculum subfields. Partial correlation analysis showed that the MoCA scores, particularly those regarding delayed memory, were significantly positively correlated with reduced hippocampal CA1 and subiculum volumes in T2DM patients. Additionally, higher HbA1c levels were significantly associated with poor memory performance and hippocampal atrophy among T2DM patients. Conclusions: These data indicate that the hippocampus might be the main affected region among the SDGM structures in T2DM. These structural changes in the hippocampal CA1 and subiculum areas might be at the core of underlying neurobiological mechanisms of hippocampal dysfunction, suggesting that degeneration in these regions could be responsible for memory impairments in T2DM patients.
Epicardial fat volume is correlated with coronary lesion and its severity
Bo, Xiaohong; Ma, Likun; Fan, Jili; Jiang, Zhe; Zhou, Yuansong; Zhang, Lei; Li, Wanjun
2015-01-01
Objective: To evaluate the correlation of epicardial adipose tissue volume (EATV) with the coronary artery lesion and its severity. Methods: Inpatients with suspicious stable angina of coronary heart lesion were recruited. For patients with coronary artery lesions in CTA, further coronary angiography (CAG) was performed to evaluate the coronary artery lesion. Gensini scoring system was employed to assess the severity of coronary artery lesions. Results: Patients were classified as coronary he...
International Nuclear Information System (INIS)
Abd-El Salam, M.H.; El-Gamal, S.; Abd El-Maqsoud, D.M.; Mohsen, M.
2013-01-01
The present study focuses on finding a correlation between the positron annihilation parameters in silicone rubber based on Poly dimethyl siloxane (PDMS) composites loaded with different conductive fillers and their swelling and electrical properties. Four types of conductive fillers have been used in this study: carbon black, graphite, copper, and nickel powders. The maximum degree of swelling Q m %, the penetration rate, P, as well as the diffusion coefficient, D, decrease with increasing the filler content due to the reduction of the size of free volume, as observed through a decrease of the probability of ortho-positronium (o-Ps) formation I 3 and the o-Ps lifetime Τ 3 , representing the size of free volume measured by the positron annihilation lifetime technique (PAL). The electrical conductivity ln (Σ) is positively correlated with the probability of free annihilation of positrons at interfaces I 2 , thus suggesting an increase in the electron density with the filler content. The activation energy of conduction, E a , is found to decrease with the increase in the loading of conductive filler and the particle size of the filler. A correlation between the free-volume V f , and the d.c. electrical conductivity ln (Σ) is found to be in accordance with Miyamoto and Shibayma model of ion conduction.
Biharmonic Submanifolds with Parallel Mean Curvature Vector in Pseudo-Euclidean Spaces
Energy Technology Data Exchange (ETDEWEB)
Fu, Yu, E-mail: yufudufe@gmail.com [Dongbei University of Finance and Economics, School of Mathematics and Quantitative Economics (China)
2013-12-15
In this paper, we investigate biharmonic submanifolds in pseudo-Euclidean spaces with arbitrary index and dimension. We give a complete classification of biharmonic spacelike submanifolds with parallel mean curvature vector in pseudo-Euclidean spaces. We also determine all biharmonic Lorentzian surfaces with parallel mean curvature vector field in pseudo-Euclidean spaces.
Biharmonic Submanifolds with Parallel Mean Curvature Vector in Pseudo-Euclidean Spaces
International Nuclear Information System (INIS)
Fu, Yu
2013-01-01
In this paper, we investigate biharmonic submanifolds in pseudo-Euclidean spaces with arbitrary index and dimension. We give a complete classification of biharmonic spacelike submanifolds with parallel mean curvature vector in pseudo-Euclidean spaces. We also determine all biharmonic Lorentzian surfaces with parallel mean curvature vector field in pseudo-Euclidean spaces
Pan, Bing; Wang, Bo
2017-10-01
Digital volume correlation (DVC) is a powerful technique for quantifying interior deformation within solid opaque materials and biological tissues. In the last two decades, great efforts have been made to improve the accuracy and efficiency of the DVC algorithm. However, there is still a lack of a flexible, robust and accurate version that can be efficiently implemented in personal computers with limited RAM. This paper proposes an advanced DVC method that can realize accurate full-field internal deformation measurement applicable to high-resolution volume images with up to billions of voxels. Specifically, a novel layer-wise reliability-guided displacement tracking strategy combined with dynamic data management is presented to guide the DVC computation from slice to slice. The displacements at specified calculation points in each layer are computed using the advanced 3D inverse-compositional Gauss-Newton algorithm with the complete initial guess of the deformation vector accurately predicted from the computed calculation points. Since only limited slices of interest in the reference and deformed volume images rather than the whole volume images are required, the DVC calculation can thus be efficiently implemented on personal computers. The flexibility, accuracy and efficiency of the presented DVC approach are demonstrated by analyzing computer-simulated and experimentally obtained high-resolution volume images.
Cerebral gray matter volume in patients with chronic migraine: correlations with clinical features.
Coppola, Gianluca; Petolicchio, Barbara; Di Renzo, Antonio; Tinelli, Emanuele; Di Lorenzo, Cherubino; Parisi, Vincenzo; Serrao, Mariano; Calistri, Valentina; Tardioli, Stefano; Cartocci, Gaia; Ambrosini, Anna; Caramia, Francesca; Di Piero, Vittorio; Pierelli, Francesco
2017-12-08
To date, few MRI studies have been performed in patients affected by chronic migraine (CM), especially in those without medication overuse. Here, we performed magnetic resonance imaging (MRI) voxel-based morphometry (VBM) analyses to investigate the gray matter (GM) volume of the whole brain in patients affected by CM. Our aim was to investigate whether fluctuations in the GM volumes were related to the clinical features of CM. Twenty untreated patients with CM without a past medical history of medication overuse underwent 3-Tesla MRI scans and were compared to a group of 20 healthy controls (HCs). We used SPM12 and the CAT12 toolbox to process the MRI data and to perform VBM analyses of the structural T1-weighted MRI scans. The GM volume of patients was compared to that of HCs with various corrected and uncorrected thresholds. To check for possible correlations, patients' clinical features and GM maps were regressed. Initially, we did not find significant differences in the GM volume between patients with CM and HCs (p tablets taken per month. No gross morphometric changes were observed in patients with CM when compared with HCs. However, using more-liberal uncorrected statistical thresholds, we observed that CM is associated with subtle GM volume changes in several brain areas known to be involved in nociception/antinociception, multisensory integration, and analgesic dependence. We speculate that these slight morphometric impairments could lead, at least in a subgroup of patients, to the development and continuation of maladaptive acute medication usage.
International Nuclear Information System (INIS)
Yi, Chin A; Na, Dong Gyu; Ryoo, Jae Wook; Moon, Chan Hong; Byun, Hong Sik; Roh, Hong Gee; Moon, Won Jin; Lee, Kwang Ho; Lee, Soo Joo
2002-01-01
To assess the utility of multiphasic perfusion CT in the prediction of final infarct volume, and the relationship between lesion volume revealed by CT imaging and clinical outcome in acute ischemic stroke patients who have not undergone thrombolytic therapy. Thirty-five patients underwent multiphasic perfusion CT within six hours of stroke onset. After baseline unenhanced helical CT scanning, contrast-enhanced CT scans were obtained 20, 34, 48, and 62 secs after the injection of 90 mL contrast medium at a rate of 3 mL/sec. CT peak and total perfusion maps were obtained from serial CT images, and the initial lesion volumes revealed by CT were compared with final infarct volumes and clinical scores. Overall, the lesion volumes seen on CT peak perfusion maps correlated most strongly with final infarct volumes (R2=0.819, p<0.001, slope of regression line=1.016), but individual data showed that they were less than final infarct volume in 31.4% of patients. In those who showed early clinical improvement (n=6), final infarct volume tended to be overestimated by CT peak perfusion mapping and only on total perfusion maps was there significant correlation between lesion volume and final infarct volume (R2=0.854, p=0.008). The lesion volumes depicted by CT maps showed moderate correlation with baseline clinical scores and clinical outcomes (R=0.445-0.706, p≤0.007). CT peak perfusion maps demonstrate strong correlation between lesion volume and final infarct volume, and accurately predict final infarct volume in about two-thirds of the 35 patients. The lesion volume seen on CT maps shows moderate correlation with clinical outcome
Pore volume is most highly correlated with the visual assessment of skin pores.
Kim, S J; Shin, M K; Back, J H; Koh, J S
2014-11-01
Many studies have been focused on evaluating assessment techniques for facial pores amid growing attention on skin care. Ubiquitous techniques used to assess the size of facial pores include visual assessment, cross-section images of the skin surface, and profilometric analysis of silicone replica of the facial skin. In addition, there are indirect assessment methods, including observation of pores based on confocal laser scanning microscopy and the analysis of sebum secretion and skin elasticity. The aim of this study was to identify parameters useful in estimating pore of surface in normal skin. The severity of pores on the cheek area by frontal optical images was divided on a 0-6 scale with '0' being faint and small pore and '6' being obvious and large pore. After the photos of the frontal cheek of 32 women aged between 35 and 49 were taken, the size of their pores was measured on a 0-6 scale; and the correlation between visual grading of pore and various evaluations (pore volume by 3-D image, pore area and number by Optical Image Analyzer) contributing to pore severity investigated using direct, objective, and noninvasive evaluations. The visual score revealed that the size of pores was graded on a 1-6 scale. Visual grading of pore was highly correlated with pore volume measured from 3-D images and pore area measured from 2-D optical images in the order (P pore was also slightly correlated with the number of pores in size of over 0.04 mm(2) (P pore score and pore volume can be explained by 3-D structural characteristics of pores. It is concluded that pore volume and area serve as useful parameters in estimating pore of skin surface. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Euclidean to Minkowski Bethe-Salpeter amplitude and observables
International Nuclear Information System (INIS)
Carbonell, J.; Frederico, T.; Karmanov, V.A.
2017-01-01
We propose a method to reconstruct the Bethe-Salpeter amplitude in Minkowski space given the Euclidean Bethe-Salpeter amplitude - or alternatively the light-front wave function - as input. The method is based on the numerical inversion of the Nakanishi integral representation and computing the corresponding weight function. This inversion procedure is, in general, rather unstable, and we propose several ways to considerably reduce the instabilities. In terms of the Nakanishi weight function, one can easily compute the BS amplitude, the LF wave function and the electromagnetic form factor. The latter ones are very stable in spite of residual instabilities in the weight function. This procedure allows both, to continue the Euclidean BS solution in the Minkowski space and to obtain a BS amplitude from a LF wave function. (orig.)
Tunneling in expanding Universe: Euclidean and Hamiltonian approaches
International Nuclear Information System (INIS)
Goncharov, A.S.; Linde, A.D.
1986-01-01
The theory of the false vacuum decay in de Sitter space and in the inflationary Universe, and also the theory of the Universe creation ''from nothing'' are discussed. This explained why tunneling in the inflationary Universe differs from that in de Sitter space and cannot be exactly homogeneous. It is shown that in several important cases the Euclidean approach should be considerably modified or is absolutely inapplicable for the description of tunneling in the expanding Universe and of the process of the quantum creation of the Universe. The Hamiltonian approach to the theory of tunneling in expanding Universe is developed. The results obtained by this method are compared with the results obtained by the Euclidean approach
Euclidean to Minkowski Bethe-Salpeter amplitude and observables
Energy Technology Data Exchange (ETDEWEB)
Carbonell, J. [Universite Paris-Sud, IN2P3-CNRS, Institut de Physique Nucleaire, Orsay Cedex (France); Frederico, T. [Instituto Tecnologico de Aeronautica, DCTA, Sao Jose dos Campos (Brazil); Karmanov, V.A. [Lebedev Physical Institute, Moscow (Russian Federation)
2017-01-15
We propose a method to reconstruct the Bethe-Salpeter amplitude in Minkowski space given the Euclidean Bethe-Salpeter amplitude - or alternatively the light-front wave function - as input. The method is based on the numerical inversion of the Nakanishi integral representation and computing the corresponding weight function. This inversion procedure is, in general, rather unstable, and we propose several ways to considerably reduce the instabilities. In terms of the Nakanishi weight function, one can easily compute the BS amplitude, the LF wave function and the electromagnetic form factor. The latter ones are very stable in spite of residual instabilities in the weight function. This procedure allows both, to continue the Euclidean BS solution in the Minkowski space and to obtain a BS amplitude from a LF wave function. (orig.)
Bayesian Approach to Spectral Function Reconstruction for Euclidean Quantum Field Theories
Burnier, Yannis; Rothkopf, Alexander
2013-11-01
We present a novel approach to the inference of spectral functions from Euclidean time correlator data that makes close contact with modern Bayesian concepts. Our method differs significantly from the maximum entropy method (MEM). A new set of axioms is postulated for the prior probability, leading to an improved expression, which is devoid of the asymptotically flat directions present in the Shanon-Jaynes entropy. Hyperparameters are integrated out explicitly, liberating us from the Gaussian approximations underlying the evidence approach of the maximum entropy method. We present a realistic test of our method in the context of the nonperturbative extraction of the heavy quark potential. Based on hard-thermal-loop correlator mock data, we establish firm requirements in the number of data points and their accuracy for a successful extraction of the potential from lattice QCD. Finally we reinvestigate quenched lattice QCD correlators from a previous study and provide an improved potential estimation at T=2.33TC.
Euclidean scalar field theory in the bilocal approximation
Nagy, S.; Polonyi, J.; Steib, I.
2018-04-01
The blocking step of the renormalization group method is usually carried out by restricting it to fluctuations and to local blocked action. The tree-level, bilocal saddle point contribution to the blocking, defined by the infinitesimal decrease of the sharp cutoff in momentum space, is followed within the three dimensional Euclidean ϕ6 model in this work. The phase structure is changed, new phases and relevant operators are found, and certain universality classes are restricted by the bilocal saddle point.
General Nth order integrals of motion in the Euclidean plane
International Nuclear Information System (INIS)
Post, S; Winternitz, P
2015-01-01
The general form of an integral of motion that is a polynomial of order N in the momenta is presented for a Hamiltonian system in two-dimensional Euclidean space. The classical and the quantum cases are treated separately, emphasizing both the similarities and the differences between the two. The main application will be to study Nth order superintegrable systems that allow separation of variables in the Hamilton–Jacobi and Schrödinger equations, respectively. (paper)
Optimal recovery of linear operators in non-Euclidean metrics
Energy Technology Data Exchange (ETDEWEB)
Osipenko, K Yu [Moscow State Aviation Technological University, Moscow (Russian Federation)
2014-10-31
The paper looks at problems concerning the recovery of operators from noisy information in non-Euclidean metrics. A number of general theorems are proved and applied to recovery problems for functions and their derivatives from the noisy Fourier transform. In some cases, a family of optimal methods is found, from which the methods requiring the least amount of original information are singled out. Bibliography: 25 titles.
Change of Measure between Light Travel Time and Euclidean Distances
Directory of Open Access Journals (Sweden)
Heymann Y.
2013-04-01
Full Text Available The problem of cosmological distances is approached using a method based on the propagation of light in an expanding Universe. From the chan ge of measure between Light Travel Time and Euclidean Distances, a formula is deri ved to compute distances as a function of redshift. This formula is identical to Matti g’s formula (with q 0 = 1 / 2 which is based on Friedmann’s equations of general relativi ty.
Correlation of pulmonary perfusion volume analysis with pulmonary function in emphysema
International Nuclear Information System (INIS)
Kaneta, Tomohiro; Yamazaki, Tetsuro; Takai, Yoshihiro; Takahashi, Shoki; Yamada, Shogo; Maruoka, Shin; Abe, Yoetsu
2000-01-01
Pulmonary perfusion single photon emission tomography with 99m Tc MAA was performed on 13 pulmonary emphysema patients and 6 controls. We calculated perfusion volume with lower 10%, 20%, 30%, 40% and 50% of the highest counts/boxels in the lung cut-off. And perfusion index (PI) was defined as follows; PI=((A% cut-off volume)-(B% cut-off volume))/(A% cut-off volume); A and B take 10 to 50, A 1 , FEV 1 %, VC, VC%, FVC, FVC%, PaO 2 and PaCO 2 ) was examined. There were significant correlation between every PI and FEV 1 or FEV 1 % (p 1 (r=0.680) and FEV 1 % (r=0.830). And the PI showed an increasing tendency along with the rise of the emphysema severity. The PI may have the clinical utility of the evaluation of pulmonary function. Moreover, we showed the lung CT painted the area where the uptake counts/boxels was more than 10% and less than 40% of the highest counts/boxels. This makes it easy to understand the severe emphysematous area. (author)
Confined detection volume of fluorescence correlation spectroscopy by bare fiber probes.
Lu, Guowei; Lei, Franck H; Angiboust, Jean-François; Manfait, Michel
2010-04-01
A fiber-tip-based near-field fluorescence correlation spectroscopy (FCS) has been developed for confining the detection volume to sub-diffraction-limited dimensions. This near-field FCS is based on near-field illumination by coupling a scanning near-field optical microscope (SNOM) to a conventional confocal FCS. Single-molecule FCS analysis at 100 nM Rhodamine 6G has been achieved by using bare chemically etched, tapered fiber tips. The detection volume under control of the SNOM system has been reduced over one order of magnitude compared to that of the conventional confocal FCS. Related factors influencing the near-field FCS performance are investigated and discussed in detail. In this proof-of-principle study, the preliminary experimental results suggest that the fiber-tip-based near-field FCS might be a good alternative to realize localized analysis at the single-molecule level.
VOLUME STUDY WITH HIGH DENSITY OF PARTICLES BASED ON CONTOUR AND CORRELATION IMAGE ANALYSIS
Directory of Open Access Journals (Sweden)
Tatyana Yu. Nikolaeva
2014-11-01
Full Text Available The subject of study is the techniques of particle statistics evaluation, in particular, processing methods of particle images obtained by coherent illumination. This paper considers the problem of recognition and statistical accounting for individual images of small scattering particles in an arbitrary section of the volume in case of high concentrations. For automatic recognition of focused particles images, a special algorithm for statistical analysis based on contouring and thresholding was used. By means of the mathematical formalism of the scalar diffraction theory, coherent images of the particles formed by the optical system with high numerical aperture were simulated. Numerical testing of the method proposed for the cases of different concentrations and distributions of particles in the volume was performed. As a result, distributions of density and mass fraction of the particles were obtained, and the efficiency of the method in case of different concentrations of particles was evaluated. At high concentrations, the effect of coherent superposition of the particles from the adjacent planes strengthens, which makes it difficult to recognize images of particles using the algorithm considered in the paper. In this case, we propose to supplement the method with calculating the cross-correlation function of particle images from adjacent segments of the volume, and evaluating the ratio between the height of the correlation peak and the height of the function pedestal in the case of different distribution characters. The method of statistical accounting of particles considered in this paper is of practical importance in the study of volume with particles of different nature, for example, in problems of biology and oceanography. Effective work in the regime of high concentrations expands the limits of applicability of these methods for practically important cases and helps to optimize determination time of the distribution character and
Directory of Open Access Journals (Sweden)
Roberto de Cleva
2014-07-01
Full Text Available OBJECTIVE:Patients undergoing abdominal surgery are at risk for pulmonary complications. The principal cause of postoperative pulmonary complications is a significant reduction in pulmonary volumes (FEV1 and FVC to approximately 65-70% of the predicted value. Another frequent occurrence after abdominal surgery is increased intra-abdominal pressure. The aim of this study was to correlate changes in pulmonary volumes with the values of intra-abdominal pressure after abdominal surgery, according to the surgical incision in the abdomen (superior or inferior.METHODS:We prospectively evaluated 60 patients who underwent elective open abdominal surgery with a surgical time greater than 240 minutes. Patients were evaluated before surgery and on the 3rd postoperative day. Spirometry was assessed by maximal respiratory maneuvers and flow-volume curves. Intra-abdominal pressure was measured in the postoperative period using the bladder technique.RESULTS:The mean age of the patients was 56±13 years, and 41.6% 25 were female; 50 patients (83.3% had malignant disease. The patients were divided into two groups according to the surgical incision (superior or inferior. The lung volumes in the preoperative period showed no abnormalities. After surgery, there was a significant reduction in both FEV1 (1.6±0.6 L and FVC (2.0±0.7 L with maintenance of FEV1/FVC of 0.8±0.2 in both groups. The maximum intra-abdominal pressure values were similar (p= 0.59 for the two groups. There was no association between pulmonary volumes and intra-abdominal pressure measured in any of the groups analyzed.CONCLUSIONS:Our results show that superior and inferior abdominal surgery determines hypoventilation, unrelated to increased intra-abdominal pressure. Patients at high risk of pulmonary complications should receive respiratory care even if undergoing inferior abdominal surgery.
Cleva, Roberto de; Assumpção, Marianna Siqueira de; Sasaya, Flavia; Chaves, Natalia Zuniaga; Santo, Marco Aurelio; Fló, Claudia; Lunardi, Adriana C; Jacob Filho, Wilson
2014-07-01
Patients undergoing abdominal surgery are at risk for pulmonary complications. The principal cause of postoperative pulmonary complications is a significant reduction in pulmonary volumes (FEV1 and FVC) to approximately 65-70% of the predicted value. Another frequent occurrence after abdominal surgery is increased intra-abdominal pressure. The aim of this study was to correlate changes in pulmonary volumes with the values of intra-abdominal pressure after abdominal surgery, according to the surgical incision in the abdomen (superior or inferior). We prospectively evaluated 60 patients who underwent elective open abdominal surgery with a surgical time greater than 240 minutes. Patients were evaluated before surgery and on the 3rd postoperative day. Spirometry was assessed by maximal respiratory maneuvers and flow-volume curves. Intra-abdominal pressure was measured in the postoperative period using the bladder technique. The mean age of the patients was 56 ± 13 years, and 41.6% 25 were female; 50 patients (83.3%) had malignant disease. The patients were divided into two groups according to the surgical incision (superior or inferior). The lung volumes in the preoperative period showed no abnormalities. After surgery, there was a significant reduction in both FEV1 (1.6 ± 0.6 L) and FVC (2.0 ± 0.7 L) with maintenance of FEV1/FVC of 0.8 ± 0.2 in both groups. The maximum intra-abdominal pressure values were similar (p=0.59) for the two groups. There was no association between pulmonary volumes and intra-abdominal pressure measured in any of the groups analyzed. Our results show that superior and inferior abdominal surgery determines hypoventilation, unrelated to increased intra-abdominal pressure. Patients at high risk of pulmonary complications should receive respiratory care even if undergoing inferior abdominal surgery.
Fan, Xiaoqian; Yuan, Ying; Zhuang, Xintian; Jin, Xiu
2017-03-01
Taking Baidu Index as a proxy for abnormal investor attention (AIA), the long memory property in the AIA of Shanghai Stock Exchange (SSE) 50 Index component stocks was empirically investigated using detrended fluctuation analysis (DFA) method. The results show that abnormal investor attention is power-law correlated with Hurst exponents between 0.64 and 0.98. Furthermore, the cross-correlations between abnormal investor attention and trading volume, volatility respectively are studied using detrended cross-correlation analysis (DCCA) and the DCCA cross-correlation coefficient (ρDCCA). The results suggest that there are positive correlations between AIA and trading volume, volatility respectively. In addition, the correlations for trading volume are in general higher than the ones for volatility. By carrying on rescaled range analysis (R/S) and rolling windows analysis, we find that the results mentioned above are effective and significant.
Maidaniuc, Andreea; Miculescu, Florin; Voicu, Stefan Ioan; Andronescu, Corina; Miculescu, Marian; Matei, Ecaterina; Mocanu, Aura Catalina; Pencea, Ion; Csaki, Ioana; Machedon-Pisu, Teodor; Ciocan, Lucian Toma
2018-04-01
Hydroxyapatite powders characteristics need to be determined both for quality control purposes and for a proper control of microstructural features of bone reconstruction products. This study combines bulk morphological and compositional analysis methods (XRF, SEM-EDS, FT-IR) with surface-related methods (XPS, contact angle measurements) in order to correlate the characteristics of hydroxyapatite powders derived from bovine bone for its use in medical applications. An experimental approach for correlating the surface and volume composition was designed based on the analysis depth of each spectral method involved in the study. Next, the influences of powder particle size and forming method on the contact angle between water drops and ceramic surface were evaluated for identifying suitable strategies of tuning hydroxyapatite's wettability. The results revealed a preferential arrangement of chemical elements at the surface of hydroxyapatite particles which could induce a favourable material behaviour in terms of sinterability and biological performance.
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Staraselski, Y; Brahme, A; Inal, K; Mishra, R K
2015-01-01
This paper presents the first application of three-dimensional (3D) cross-correlation microstructure reconstruction implemented for a representative volume element (RVE) to facilitate the microstructure engineering of materials. This has been accomplished by developing a new methodology for reconstructing 3D microstructure using experimental two-dimensional electron backscatter diffraction data. The proposed methodology is based on the analytical representation of the generalized form of the two-point correlation function—the distance-disorientation function (DDF). Microstructure reconstruction is accomplished by extending the simulated annealing techniques to perform three term reconstruction with a minimization of the DDF. The new 3D microstructure reconstruction algorithm is employed to determine the 3D RVE containing all of the relevant microstructure information for accurately computing the mechanical response of solids, especially when local microstructural variations influence the global response of the material as in the case of fracture initiation. (paper)
Camiciottoli, G; Diciotti, S; Bartolucci, M; Orlandi, I; Bigazzi, F; Matucci-Cerinic, M; Pistolesi, M; Mascalchi, M
2013-03-01
Spiral low-dose computed tomography (LDCT) permits to measure whole-lung volume and density in a single breath-hold. To evaluate the agreement between static lung volumes measured with LDCT and pulmonary function test (PFT) and the correlation between the LDCT volumes and lung density in restrictive lung disease. Patients with Systemic Sclerosis (SSc) with (n = 24) and without (n = 16) pulmonary involvement on sequential thin-section CT and patients with chronic obstructive pulmonary disease (COPD)(n = 29) underwent spirometrically-gated LDCT at 90% and 10% of vital capacity to measure inspiratory and expiratory lung volumes and mean lung attenuation (MLA). Total lung capacity and residual volume were measured the same day of CT. Inspiratory [95% limits of agreement (95% LoA)--43.8% and 39.2%] and expiratory (95% LoA -45.8% and 37.1%) lung volumes measured on LDCT and PFT showed poor agreement in SSc patients with pulmonary involvement, whereas they were in substantial agreement (inspiratory 95% LoA -14.1% and 16.1%; expiratory 95% LoA -13.5% and 23%) in SSc patients without pulmonary involvement and in inspiratory scans only (95% LoA -23.1% and 20.9%) of COPD patients. Inspiratory and expiratory LDCT volumes, MLA and their deltas differentiated both SSc patients with or without pulmonary involvement from COPD patients. LDCT lung volumes and density were not correlated in SSc patients with pulmonary involvement, whereas they did correlate in SSc without pulmonary involvement and in COPD patients. In restrictive lung disease due to SSc there is poor agreement between static lung volumes measured using LDCT and PFT and the relationship between volume and density values on CT is altered.
Moussawi, Ali; Xu, Jiangping; Nouri, Hedi; Guessasma, Sofiane; Lubineau, Gilles
2014-01-01
are processed using image analysis. A subset-based digital volume correlation method is used to achieve the 3D displacement field. Within the limit of the approach, deterministic search strategy is implemented for solving subset displacement in each deformed
Engman, Mikael; Varghese, Suby; Lagerstedt Robinson, Kristina; Malmgren, Helena; Hammarsjö, Anna; Byström, Birgitta; L Lalitkumar, Parameswaran Grace; Gemzell-Danielsson, Kristina
2013-01-01
Progesterone receptor modulators, such as mifepristone are useful and well tolerated in reducing leiomyoma volume although with large individual variation. The objective of this study was to investigate the molecular basis for the observed leiomyoma volume reduction, in response to mifepristone treatment and explore a possible molecular marker for the selective usage of mifepristone in leiomyoma patients. Premenopausal women (N = 14) were treated with mifepristone 50 mg, every other day for 12 weeks prior to surgery. Women were arbitrarily sub-grouped as good (N = 4), poor (N = 4) responders to treatment or intermediate respondents (N = 3). Total RNA was extracted from leiomyoma tissue, after surgical removal of the tumour and the differential expression of genes were analysed by microarray. The results were analysed using Ingenuity Pathway Analysis software. The glutathione pathway was the most significantly altered canonical pathway in which the glutathione-s transferase mu 1 (GSTM1) gene was significantly over expressed (+8.03 folds) among the good responders compared to non responders. This was further confirmed by Real time PCR (p = 0.024). Correlation of immunoreactive scores (IRS) for GSTM1 accumulation in leiomyoma tissue was seen with base line volume change of leiomyoma R = −0.8 (p = 0.011). Furthermore the accumulation of protein GSTM1 analysed by Western Blot correlated significantly with the percentual leiomyoma volume change R = −0.82 (p = 0.004). Deletion of the GSTM1 gene in leiomyoma biopsies was found in 50% of the mifepristone treated cases, with lower presence of the GSTM1 protein. The findings support a significant role for GSTM1 in leiomyoma volume reduction induced by mifepristone and explain the observed individual variation in this response. Furthermore the finding could be useful to further explore GSTM1 as a biomarker for tailoring medical treatment of uterine leiomyomas for optimizing the response
Structural and volume changes and their correlation in electron irradiated alkali silicate glasses
International Nuclear Information System (INIS)
Gavenda, Tadeáš; Gedeon, Ondrej; Jurek, Karel
2017-01-01
Highlights: • Volume changes were correlated with both incubation dose and Raman spectra. • Irradiation decreases Si-O-Si angle and increases the amount of three-membered rings. • Levelling of the pits depends on the dose below and above incubation dose. • Restoration of the original structure was limited to low-frequency region. - Abstract: Two binary alkali silicate glasses (15K 2 O·85SiO 2 – denoted as K15 and 15Li 2 O·85SiO 2 – denoted as Li15) were irradiated by 50 keV electron beams with doses within the range of 2.1–15.9 kC/m 2 . Volume changes induced by electron irradiation were monitored by means of Atomic Force Microscopy (AFM). Raman spectra were taken from the irradiated spots to observe structural changes. Volume compaction observed at lower doses was correlated with the increase of the D2 peak. Volume expansion at higher doses was related to migration of alkali ions. Irradiated glasses were annealed at 400 °C and 500 °C for 60 min. After annealing irradiated spots were again examined by AFM and Raman spectroscopy in order to determine volume and structural relaxation of radiation induced changes. Annealing at higher temperatures resulted in the levelling of the pits created by irradiation, but only for doses below incubation dose. The pits created by doses above incubation dose were not levelled. Annealing caused decrease of D2 peak and shift of the Si-O-Si vibrations band in direction to original structure. Low-frequency region of annealed Li15 glass was undistinguishable from that of pristine glass, while annealing of K15 glass did not result in the full reversion to the original shape. The differences between glasses were attributed to higher T g of K15 glass. Q-motives bands of both glasses were not completely restored after annealing due to the absence of alkali ions.
Structural and volume changes and their correlation in electron irradiated alkali silicate glasses
Energy Technology Data Exchange (ETDEWEB)
Gavenda, Tadeáš, E-mail: gavendat@vscht.cz [Department of Glass and Ceramics, University of Chemical Technology, Technicka 5, CZ-166 28 Prague (Czech Republic); Gedeon, Ondrej [Department of Glass and Ceramics, University of Chemical Technology, Technicka 5, CZ-166 28 Prague (Czech Republic); Jurek, Karel [Institute of Physics, Academy of the Czech Republic, Na Slovance 2, CZ-182 21 Prague (Czech Republic)
2017-04-15
Highlights: • Volume changes were correlated with both incubation dose and Raman spectra. • Irradiation decreases Si-O-Si angle and increases the amount of three-membered rings. • Levelling of the pits depends on the dose below and above incubation dose. • Restoration of the original structure was limited to low-frequency region. - Abstract: Two binary alkali silicate glasses (15K{sub 2}O·85SiO{sub 2} – denoted as K15 and 15Li{sub 2}O·85SiO{sub 2} – denoted as Li15) were irradiated by 50 keV electron beams with doses within the range of 2.1–15.9 kC/m{sup 2}. Volume changes induced by electron irradiation were monitored by means of Atomic Force Microscopy (AFM). Raman spectra were taken from the irradiated spots to observe structural changes. Volume compaction observed at lower doses was correlated with the increase of the D2 peak. Volume expansion at higher doses was related to migration of alkali ions. Irradiated glasses were annealed at 400 °C and 500 °C for 60 min. After annealing irradiated spots were again examined by AFM and Raman spectroscopy in order to determine volume and structural relaxation of radiation induced changes. Annealing at higher temperatures resulted in the levelling of the pits created by irradiation, but only for doses below incubation dose. The pits created by doses above incubation dose were not levelled. Annealing caused decrease of D2 peak and shift of the Si-O-Si vibrations band in direction to original structure. Low-frequency region of annealed Li15 glass was undistinguishable from that of pristine glass, while annealing of K15 glass did not result in the full reversion to the original shape. The differences between glasses were attributed to higher T{sub g} of K15 glass. Q-motives bands of both glasses were not completely restored after annealing due to the absence of alkali ions.
Late dysphagia after IMRT for head and neck cancer and correlation with dose–volume parameters
International Nuclear Information System (INIS)
Mortensen, Hanna R.; Jensen, Kenneth; Aksglæde, Karin; Behrens, Marie; Grau, Cai
2013-01-01
Background and purpose: Many head and neck cancer (HNC) survivors experience diminished quality of life due to radiation-induced dysphagia. The aim of this study was to investigate frequency, intensity and dose–volume dependency for late dysphagia in HNC patients treated with curative IMRT. Materials and methods: Candidates for the study were 294 patients treated with primary IMRT from 2006 to 2010; a total of 259 patients accepted to participate by answering the EORTC QLQ-C30 and H and N35 questionnaires. A total of 65 patients were further examined with modified barium swallow (MBS) and saliva collection. Data on patient, tumor and treatment characteristics were prospectively recorded in the DAHANCA database. Dose–volume histograms (DVH) of swallowing-related structures were retrospectively analyzed. Results: QoL data showed low degree of dysphagia (QoL subscales scores of 17 and below) compared to objective measures. The most frequent swallowing dysfunction was retention; penetration and aspiration was less common. In general, objective measurements and observer-assessed late dysphagia correlated with dose to pharyngeal constrictor muscles (PCM), whereas QoL endpoints correlated with DVH parameters in the glottis/supraglottic larynx. Both xerostomia and dysphagia has been reduced after introduction of IMRT. Conclusions: Radiation-induced dysphagia is still important, with a high degree of retention and penetration. Introduction of parotid-sparing IMRT has reduced the severity of dysphagia, primarily through a major reduction in xerostomia. Dose–response relationships were found for specific dysphagia endpoints
International Nuclear Information System (INIS)
Teshima, Keiko; Murakami, Ryuji; Tomitaka, Etsuji
2010-01-01
The objective of this study was to evaluate whether saliva production reflects the parotid volume during the course of radiation therapy (RT) in patients with head-and-neck cancer. Twenty patients with advanced oral squamous cell carcinomas, who were treated with preoperative chemo-RT, underwent morphological assessment with CT or MRI and functional assessment with the Saxon test. For the Saxon test, saliva production was measured by weighing a gauze pad before and 2 min after chewing without swallowing; the low-normal value is 2 g. Saliva production and parotid volumes before and 2 weeks after RT were compared with the paired t-test, the Spearman rank correlation test and the Fisher exact test. After 30 Gy irradiation, mean saliva production was decreased from 4.2 to 1.0 g (P 3 (P<0.01); the post-RT: pre-RT parotid volume ratio ranged from 54% to 85% (mean 71%). Although the initial parotid volume was correlated with initial saliva production (r=0.47, P=0.04), no significant correlation was noted after RT (r=0.08, P=0.71), and there were considerable individual variations. The parotid volume ratio was inversely correlated with the saliva-reduction amount (r=-0.79, P<0.01). There was a correlation between decreased parotid gland volume and decreased saliva production in patients with head-and-neck cancer undergoing RT. Parotid volume reduction may predict parotid gland function. (author)
Spinors and supersymmetry in four-dimensional Euclidean space
International Nuclear Information System (INIS)
McKeon, D.G.C.; Sherry, T.N.
2001-01-01
Spinors in four-dimensional Euclidean space are treated using the decomposition of the Euclidean space SO(4) symmetry group into SU(2)xSU(2). Both 2- and 4-spinor representations of this SO(4) symmetry group are shown to differ significantly from the corresponding spinor representations of the SO(3, 1) symmetry group in Minkowski space. The simplest self conjugate supersymmetry algebra allowed in four-dimensional Euclidean space is demonstrated to be an N=2 supersymmetry algebra which resembles the N=2 supersymmetry algebra in four-dimensional Minkowski space. The differences between the two supersymmetry algebras gives rise to different representations; in particular an analysis of the Clifford algebra structure shows that the momentum invariant is bounded above by the central charges in 4dE, while in 4dM the central charges bound the momentum invariant from below. Dimensional reduction of the N=1 SUSY algebra in six-dimensional Minkowski space (6dM) to 4dE reproduces our SUSY algebra in 4dE. This dimensional reduction can be used to introduce additional generators into the SUSY algebra in 4dE. Well known interpolating maps are used to relate the N=2 SUSY algebra in 4dE derived in this paper to the N=2 SUSY algebra in 4dM. The nature of the spinors in 4dE allows us to write an axially gauge invariant model which is shown to be both Hermitian and anomaly-free. No equivalent model exists in 4dM. Useful formulae in 4dE are collected together in two appendixes
Convergent perturbation expansions for Euclidean quantum field theory
International Nuclear Information System (INIS)
Mack, G.; Pordt, A.
1984-09-01
Mayer perturbation theory is designed to provide computable convergent expansions which permit calculation of Greens functions in Euclidean Quantum Field Theory to arbitrary accuracy, including 'nonperturbative' contributions from large field fluctuations. Here we describe the expansions at the example of 3-dimensional lambdaphi 4 -theory (in continuous space). They are not essentially more complicated than standard perturbation theory. The n-th order term is expressed in terms of 0(n)-dimensional integrals, and is of order lambda 4 if 4k-3<=n<=4k. (orig.)
Euclidean D-branes and higher-dimensional gauge theory
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Acharya, B.S.; Figueroa-O'Farrill, J.M.; Spence, B.; O'Loughlin, M.
1997-07-01
We consider euclidean D-branes wrapping around manifolds of exceptional holonomy in dimensions seven and eight. The resulting theory on the D-brane-that is, the dimensional reduction of 10-dimensional supersymmetric Yang-Mills theory-is a cohomological field theory which describes the topology of the moduli space of instantons. The 7-dimensional theory is an N T =2 (or balanced) cohomological theory given by an action potential of Chern-Simons type. As a by-product of this method, we construct a related cohomological field theory which describes the monopole moduli space on a 7-manifold of G 2 holonomy. (author). 22 refs, 3 tabs
The G_Newton --> 0 Limit of Euclidean Quantum Gravity
Smolin, Lee
1992-01-01
Using the Ashtekar formulation, it is shown that the G_{Newton} --> 0 limit of Euclidean or complexified general relativity is not a free field theory, but is a theory that describes a linearized self-dual connection propagating on an arbitrary anti-self-dual background. This theory is quantized in the loop representation and, as in the full theory, an infinite dimnensional space of exact solutions to the constraint is found. An inner product is also proposed. The path integral is constructed...
Multi-stability in folded shells: non-Euclidean origami
Evans, Arthur
2015-03-01
Both natural and man-made structures benefit from having multiple mechanically stable states, from the quick snapping motion of hummingbird beaks to micro-textured surfaces with tunable roughness. Rather than discuss special fabrication techniques for creating bi-stability through material anisotropy, in this talk I will present several examples of how folding a structure can modify the energy landscape and thus lead to multiple stable states. Using ideas from origami and differential geometry, I will discuss how deforming a non-Euclidean surface can be done either continuously or discontinuously, and explore the effects that global constraints have on the ultimate stability of the surface.
ILUCG algorithm which minimizes in the Euclidean norm
International Nuclear Information System (INIS)
Petravic, M.; Kuo-Petravic, G.
1978-07-01
An algroithm is presented which solves sparse systems of linear equations of the form Ax = Y, where A is non-symmetric, by the Incomplete LU Decomposition-Conjugate Gradient (ILUCG) method. The algorithm minimizes the error in the Euclidean norm vertical bar x/sub i/ - x vertical bar 2 , where x/sub i/ is the solution vector after the i/sup th/ iteration and x the exact solution vector. The results of a test on one real problem indicate that the algorithm is likely to be competitive with the best existing algorithms of its type
A Class of Weingarten Surfaces in Euclidean 3-Space
Directory of Open Access Journals (Sweden)
Yu Fu
2013-01-01
Full Text Available The class of biconservative surfaces in Euclidean 3-space 3 are defined in (Caddeo et al., 2012 by the equation A(grad H=-H grad H for the mean curvature function H and the Weingarten operator A. In this paper, we consider the more general case that surfaces in 3 satisfying A(grad H=kH grad H for some constant k are called generalized bi-conservative surfaces. We show that this class of surfaces are linear Weingarten surfaces. We also give a complete classification of generalized bi-conservative surfaces in 3.
A strong coupling simulation of Euclidean quantum gravity
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Berg, B.; Hamburg Univ.
1984-12-01
Relying on Regge calculus a systematic numerical investigation of models of 4d Euclidean gravity is proposed. The scale a = 1 0 is set by fixing the expectation value of a length. Possible universality of such models is discussed. The strong coupling limit is defined by taking Planck mass msub(p) -> 0 (in units of 1 0 -1 ). The zero order approximation msub(p) = 0 is called 'fluctuating space' and investigated numerically in two 4d models. Canonical dimensions are realized and both models give a negative expectation value for the scalar curvature density. (orig.)
Nanda, Pranav; Tandon, Neeraj; Mathew, Ian T; Padmanabhan, Jaya L; Clementz, Brett A; Pearlson, Godfrey D; Sweeney, John A; Tamminga, Carol A; Keshavan, Matcheri S
2016-01-01
Patients with psychotic disorders appear to exhibit greater impulsivity-related behaviors relative to healthy controls. However, the neural underpinning of this impulsivity remains uncertain. Furthermore, it remains unclear how impulsivity might differ or be conserved between psychotic disorder diagnoses in mechanism and manifestation. In this study, self-reported impulsivity, measured by Barratt Impulsiveness Scale (BIS), was compared between 305 controls (HC), 139 patients with schizophrenia (SZ), 100 with schizoaffective disorder (SZA), and 125 with psychotic bipolar disorder (PBP). In each proband group, impulsivity was associated with regional cortical volumes (using FreeSurfer analysis of T1 MRI scans), suicide attempt history, Global Assessment of Functioning (GAF), and Social Functioning Scale (SFS). BIS scores were found to differ significantly between participant groups, with SZA and PBP exhibiting significantly higher impulsivity than SZ, which exhibited significantly higher impulsivity than HC. BIS scores were significantly related to suicide attempt history, and they were inversely associated with GAF, SFS, and bilateral orbitofrontal cortex (OFC) volume in both SZA and PBP, but not SZ. These findings indicate that psychotic disorders, particularly those with prominent affective symptoms, are characterized by elevated self-reported impulsivity measures. Impulsivity's correlations with suicide attempt history, GAF, and SFS suggest that impulsivity may be a mediator of clinical outcome. The observed impulsivity-OFC correlations corroborate the importance of OFC deficits in impulsivity. These correlations' presence in SZA and PBP but not in SZ suggests that impulsivity may have different underlying mechanisms in affective and non-affective psychotic disorders. Copyright © 2015 Elsevier B.V. All rights reserved.
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Grotenhuis, Heynric B. [The University of Toronto, Division of Cardiology, Department of Paediatrics, The Labatt Family Heart Centre, The Hospital for Sick Children, Toronto (Canada); Zhou, Cheng; Isaac, Kathryn V. [The University of Toronto, Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto (Canada); Tomlinson, George [University of Toronto, Department of Medicine, Toronto General Hospital and Mt. Sinai Hospital, Toronto (Canada); Seed, Mike; Grosse-Wortmann, Lars; Yoo, Shi-Joon [The University of Toronto, Division of Cardiology, Department of Paediatrics, The Labatt Family Heart Centre, The Hospital for Sick Children, Toronto (Canada); The University of Toronto, Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto (Canada)
2015-10-15
The cardiothoracic ratio by chest radiograph is widely used as a marker of cardiac size. The purpose of this study is to correlate cardiothoracic ratio and cardiac volumes as measured by cardiovascular magnetic resonance (MR) in common structural and myopathic heart disease with increased cardiac size due to volume overload or hypertrophy. A retrospective single center study was performed in all patients between 2007 and 2013 with repaired tetralogy of Fallot (TOF), aortic regurgitation, isolated left-to-right shunt and hypertrophic cardiomyopathy (HCM) who underwent cardiovascular MR and chest radiograph within 6 months of each other. Cardiothoracic ratios by chest radiograph (frontal and lateral) were compared to cardiac volumes (indexed for body surface area) by cardiovascular MR. One hundred twenty-seven patients (mean age: 11.2 ± 5.5 years) were included in this study (76 with TOF, 23 with isolated left-to-right shunt, 16 with aortic regurgitation and 12 with HCM). Frontal cardiothoracic ratio of all groups correlated with indexed right ventricular (RV) end-diastolic volume (EDVI) (r = 0.40, P < 0.01) and indexed total heart volume (THVI) (r = 0.27, P < 0.01). In TOF patients, frontal cardiothoracic ratio correlated with RVEDVI (r = 0.34, P < 0.01; coefficient of variation = 27.6%), indexed RV end-systolic volume (ESVI) (r = 0.44, P < 0.01; coefficient of variation = 33.3%) and THVI (r = 0.35, P < 0.01; coefficient of variation = 19.6%), although RV volumes and THVI showed widespread variation given the high coefficients of variation. In patients with aortic regurgitation, frontal cardiothoracic ratio correlated with left ventricular (LV) EDVI (r = 0.50, P = 0.047), but not with THVI and aortic regurgitant fraction, and widespread variation for LV EDVI (coefficient of variation = 19.2%), LV ESVI (coefficient of variation = 32.5%) and THVI (coefficient of variation = 13.6%) was also observed. Frontal cardiothoracic ratio was not correlated with cardiac volumes
Intrasubject correlation between static scan and distribution volume images for [11C]flumazenil PET
International Nuclear Information System (INIS)
Mishina, Masahiro; Senda, Michio; Kimura, Yuichi
2000-01-01
Accumulation of [ 11 C]flumazenil (FMZ) reflects central nervous system benzodiazepine receptor (BZR). We searched for the optimal time for a static PET scan with FMZ as semi-quantitative imaging of BZR distribution. In 10 normal subjects, a dynamic series of decay-corrected PET scans was performed for 60 minutes, and the arterial blood was sampled during the scan to measure radioactivity and labeled metabolites. We generated 13 kinds of ''static scan'' images from the dynamic scan in each subject, and analyzed the pixel correlation for these images versus distribution volume (DV) images. We also analyzed the time for the [ 11 C]FMZ in plasma and tissue to reach the equilibrium. The intra-subject pixel correlation demonstrated that the static scan'' images for the period centering around 30 minutes post-injection had the strongest linear correlation with the DV image. The ratio of radioactivity in the cortex to that in the plasma reached a peak at 40 minutes after injection. Considering the physical decay and patient burden, we conclude that the decay corrected static scan for [ 11 C]FMZ PET as semi-quantitative imaging of BZR distribution is to be optimally acquired from 20 to 40 minutes after injection. (author)
Texture classification using non-Euclidean Minkowski dilation
Florindo, Joao B.; Bruno, Odemir M.
2018-03-01
This study presents a new method to extract meaningful descriptors of gray-scale texture images using Minkowski morphological dilation based on the Lp metric. The proposed approach is motivated by the success previously achieved by Bouligand-Minkowski fractal descriptors on texture classification. In essence, such descriptors are directly derived from the morphological dilation of a three-dimensional representation of the gray-level pixels using the classical Euclidean metric. In this way, we generalize the dilation for different values of p in the Lp metric (Euclidean is a particular case when p = 2) and obtain the descriptors from the cumulated distribution of the distance transform computed over the texture image. The proposed method is compared to other state-of-the-art approaches (such as local binary patterns and textons for example) in the classification of two benchmark data sets (UIUC and Outex). The proposed descriptors outperformed all the other approaches in terms of rate of images correctly classified. The interesting results suggest the potential of these descriptors in this type of task, with a wide range of possible applications to real-world problems.
Speckle Suppression by Weighted Euclidean Distance Anisotropic Diffusion
Directory of Open Access Journals (Sweden)
Fengcheng Guo
2018-05-01
Full Text Available To better reduce image speckle noise while also maintaining edge information in synthetic aperture radar (SAR images, we propose a novel anisotropic diffusion algorithm using weighted Euclidean distance (WEDAD. Presented here is a modified speckle reducing anisotropic diffusion (SRAD method, which constructs a new edge detection operator using weighted Euclidean distances. The new edge detection operator can adaptively distinguish between homogenous and heterogeneous image regions, effectively generate anisotropic diffusion coefficients for each image pixel, and filter each pixel at different scales. Additionally, the effects of two different weighting methods (Gaussian weighting and non-linear weighting of de-noising were analyzed. The effect of different adjustment coefficient settings on speckle suppression was also explored. A series of experiments were conducted using an added noise image, GF-3 SAR image, and YG-29 SAR image. The experimental results demonstrate that the proposed method can not only significantly suppress speckle, thus improving the visual effects, but also better preserve the edge information of images.
On the Schroedinger representation of the Euclidean quantum field theory
International Nuclear Information System (INIS)
Semmler, U.
1987-04-01
The theme of the present thesis is the Schroedinger representation of the Euclidean quantum field theory: We define the time development of the quantum field states as functional integral in a novel, mathematically precise way. In the following we discuss the consequences which result from this approach to the Euclidean quantum field theory. Chapter 1 introduces the theory of abstract Wiener spaces which is here proved as suitable mathematical tool for the treatment of the physical problems. In chapter 2 the diffusion theory is formulated in the framework of abstract Wiener spaces. In chapter 3 we define the field functional ψ 5 u, t 7 as functional integral, determine the functional differential equation which ψ satisfies (Schroedinger equation), and summarize the consequences resulting from this. Chapter 4 is dedicated to the attempt to determine the kernel of the time-development operator, by the knowledge of which the time development of each initial state is fixed. In chapter 5 the consequences of the theory presented in chapter 3 and 4 are discussed by means of simple examples. In chapter 6 the renormalization which results for the φ 4 potential from the definition of the functional integral in chapter 3 is calculated up to the first-order perturbation theory, and it is shown that the problems in the Symanzik renormalization procedure can be removed. (orig./HSI) [de
Euclidean and Minkowski space formulations of linearized gravitational potential in various gauges
International Nuclear Information System (INIS)
Lim, S.C.
1979-01-01
We show that there exists a unitary map connecting linearized theories of gravitational potential in vacuum, formulated in various covariant gauges and noncovariant radiation gauge. The free Euclidean gravitational potentials in covariant gauges satisfy the Markov property of Nelson, but are nonreflexive. For the noncovariant radiation gauge, the corresponding Euclidean field is reflexive but it only satisfies the Markov property with respect to special half spaces. The Feynman--Kac--Nelson formula is established for the Euclidean gravitational potential in radiation gauge
Isometric immersions and embeddings of locally Euclidean metrics in R2
International Nuclear Information System (INIS)
Sabitov, I Kh
1999-01-01
This paper deals with the problem of isometric immersions and embeddings of two-dimensional locally Euclidean metrics in the Euclidean plane. We find explicit formulae for the immersions of metrics defined on a simply connected domain and a number of sufficient conditions for the existence of isometric embeddings. In the case when the domain is multiply connected we find necessary conditions for the existence of isometric immersions and classify the cases when the metric admits no isometric immersion in the Euclidean plane
Directory of Open Access Journals (Sweden)
Basak Ceyda Meco
Full Text Available BACKGROUND AND OBJECTIVES: Preoperative ultrasonographic evaluation of the thyroid gland done by surgeons could let us foresee airway management challenges. The aim of this observational study was to evaluate the effects of thyroid-related parameters assessed preoperatively by surgeons via ultrasonography and chest X-ray on intubation conditions. METHODS: Fifty patients undergoing thyroid surgery were enrolled. Thyromental distance, Mallampati score, neck circumference and range of neck movement were evaluated before the operation. Thyroid volume, signs of invasion or compression and tracheal deviation on chest X-ray were also noted. The intubation conditions were assessed with Cormack and Lehane score and the intubation difficulty scale. Statistical analyses were done with SPSS 15.0 software. RESULTS: The mean thyroid volume of the patients was 26.38 ± 14 mL. The median intubation difficulty scale was 1 (0-2. Thyromental distance (p = 0.011; r = 0.36; 95% CI 0.582-0.088, Mallampati score (p = 0.041; r = 0.29; 95% CI 0.013-0.526, compression or invasion signs (p = 0.041; r = 0.28; 95% CI 0.006-0.521 and tracheal deviation on chest X-ray (p = 0.041; r = 0.52; 95% CI 0.268-0.702 were correlated with intubation difficulty scale. Also patients were classified into two groups related to their intubation difficulty scale (Group I, n = 19: intubation difficulty scale = 0; Group II, n = 31: 1 < intubation difficulty scale ≤ 5 and difficult intubation predictors and thyroid-related parameters were compared. Only Mallampati score was significantly different between groups (p = 0.025. CONCLUSION: The thyroid volume is not associated with difficult intubation. However clinical assessment parameters may predict difficult intubation.
In-Situ Systematic Error Correction for Digital Volume Correlation Using a Reference Sample
Wang, B.
2017-11-27
The self-heating effect of a laboratory X-ray computed tomography (CT) scanner causes slight change in its imaging geometry, which induces translation and dilatation (i.e., artificial displacement and strain) in reconstructed volume images recorded at different times. To realize high-accuracy internal full-field deformation measurements using digital volume correlation (DVC), these artificial displacements and strains associated with unstable CT imaging must be eliminated. In this work, an effective and easily implemented reference sample compensation (RSC) method is proposed for in-situ systematic error correction in DVC. The proposed method utilizes a stationary reference sample, which is placed beside the test sample to record the artificial displacement fields caused by the self-heating effect of CT scanners. The detected displacement fields are then fitted by a parametric polynomial model, which is used to remove the unwanted artificial deformations in the test sample. Rescan tests of a stationary sample and real uniaxial compression tests performed on copper foam specimens demonstrate the accuracy, efficacy, and practicality of the presented RSC method.
Hou, Yi-Cheng; Lai, Chien-Han; Wu, Yu-Te; Yang, Shwu-Huey
2016-01-01
Abstract The neurophysiology of prediabetes plays an important role in preventive medicine. The dysregulation of glucose metabolism is likely linked to changes in neuron-related gray matter. Therefore, we designed this study to investigate gray matter alterations in medication-naive prediabetic patients. We expected to find alterations in the gray matter of prediabetic patients. A total of 64 prediabetic patients and 54 controls were enrolled. All subjects received T1 scans using a 3-T magnetic resonance imaging machine. Subjects also completed nutritional intake records at the 24-hour and 3-day time points to determine their carbohydrate, protein, fat, and total calorie intake. We utilized optimized voxel-based morphometry to estimate the gray matter differences between the patients and controls. In addition, the preprandial serum glucose level and the carbohydrate, protein, fat, and total calorie intake levels were tested to determine whether these parameters were correlated with the gray matter volume. Prediabetic patients had lower gray matter volumes than controls in the right anterior cingulate gyrus, right posterior cingulate gyrus, left insula, left super temporal gyrus, and left middle temporal gyrus (corrected P prediabetic patients. PMID:27336893
In-Situ Systematic Error Correction for Digital Volume Correlation Using a Reference Sample
Wang, B.; Pan, B.; Lubineau, Gilles
2017-01-01
The self-heating effect of a laboratory X-ray computed tomography (CT) scanner causes slight change in its imaging geometry, which induces translation and dilatation (i.e., artificial displacement and strain) in reconstructed volume images recorded at different times. To realize high-accuracy internal full-field deformation measurements using digital volume correlation (DVC), these artificial displacements and strains associated with unstable CT imaging must be eliminated. In this work, an effective and easily implemented reference sample compensation (RSC) method is proposed for in-situ systematic error correction in DVC. The proposed method utilizes a stationary reference sample, which is placed beside the test sample to record the artificial displacement fields caused by the self-heating effect of CT scanners. The detected displacement fields are then fitted by a parametric polynomial model, which is used to remove the unwanted artificial deformations in the test sample. Rescan tests of a stationary sample and real uniaxial compression tests performed on copper foam specimens demonstrate the accuracy, efficacy, and practicality of the presented RSC method.
DEFF Research Database (Denmark)
Bønnelykke-Behrndtz, Marie Louise; Sørensen, Flemming Brandt; Damsgaard, Tine Engberg
2008-01-01
potential indicators of prognosis. Sixty patients who underwent surgery at the Department of Plastic Surgery, Aarhus University Hospital, from 1991 to 1994 were included in the study. Total tumor volume was estimated by the Cavalieri technique, total number of tumor cells by the optical dissector principle...... showed a significant impact on both disease-free survival (p=0.001) and mortality (p=0.009). In conclusion, tumor volume and total number of cancer cells were highly reproducible but did not add additional, independent prognostic information regarding the study population.......Stereological quantification of tumor volume, total number of tumor cells and mean nuclear volume provides unbiased data, regardless of the three-dimensional shape of the melanocytic lesion. The aim of the present study was to investigate whether these variables are reproducible and may represent...
International Nuclear Information System (INIS)
Sato, Taku; Sakuma, Jun; Sasaki, Tatsuya
2011-01-01
Subarachnoid hemorrhage (SAH) volume was measured by three-dimensional computed tomography (3D-CT) and the correlation examined between the SAH volume and the occurrence of symptomatic vasospasm (SVS). Experimental (in vitro) hematomas were made with blood obtained from 10 volunteers. The hematoma volume was determined by actual measurements and by 3D-CT using a CT number in the range of 40-80 Hounsfield units (HU) on days 1, 4, 7, 11, and 14. The coefficients on days 1 and 4 were relatively high and the correlation between measured and estimated volumes was significant on days 7, 11, and 14. 3D-CT was also performed in 50 patients with SAH at onset (day 0) and on days 1, 4, 7, and 14. The hematoma volume including the volume of normal structures was automatically calculated (V1). The volume of normal structures (V2) with CT numbers of 40-80 HU was calculated in another 50 patients without intracranial lesions as 12 ml. The total hematoma volume was defined as V1 minus mean V2. The mean SAH volume was 44, 36, 21, 11, and 8 ml on days 0, 1, 4, 7, and 14, respectively. The hematoma volumes were significantly larger in patients with SVS than in patients without SVS at all time points. The minimum hematoma volume in patients with SVS was 92, 76, 42, 24, and 12 ml on days 0, 1, 4, 7, and 14, respectively. This method allows the quantitative determination of SAH volume based on 3D-CT, and may be useful in clinical studies of cerebral vasospasm. (author)
Energy Technology Data Exchange (ETDEWEB)
Moon, Chung-Man [Chonnam National University Hospital, Research Institute for Medical Imaging, Gwangju (Korea, Republic of); Jeong, Gwang-Woo [Chonnam National University Hospital, Research Institute for Medical Imaging, Gwangju (Korea, Republic of); Chonnam National University Medical School, Department of Radiology, Chonnam National University Hospital, Gwangju (Korea, Republic of)
2015-11-15
Only a few morphological studies have focused on changes in white matter (WM) volume in patients with generalized anxiety disorder (GAD). We evaluated alterations in WM volume and its correlation with symptom severity and duration of illness in adults with GAD. The 44 subjects were comprised of 22 patients with GAD (13 males and nine females) diagnosed using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) and 22 age-matched healthy controls (13 males and nine females). High-resolution magnetic resonance imaging (MRI) data were processed by voxel-based morphometry (VBM) analysis based on diffeomorphic anatomical registration using the exponentiated Lie algebra (DARTEL) algorithm in SPM8. Patients with GAD showed significantly reduced WM volume, particularly in the dorsolateral prefrontal cortex (DLPFC), anterior limb of the internal capsule (ALIC), and midbrain. In addition, DLPFC volume was negatively correlated with GAD-7 score and illness duration. ALIC volume was negatively correlated with GAD-7 score. Female patients had significantly less orbitofrontal cortex volume compared to that in male patients. The findings demonstrate localized changes in WM volume associated with cognitive and emotional dysfunction in patients with GAD. The finding will be helpful for understanding the neuropathology in patients with GAD. (orig.)
International Nuclear Information System (INIS)
Moon, Chung-Man; Jeong, Gwang-Woo
2015-01-01
Only a few morphological studies have focused on changes in white matter (WM) volume in patients with generalized anxiety disorder (GAD). We evaluated alterations in WM volume and its correlation with symptom severity and duration of illness in adults with GAD. The 44 subjects were comprised of 22 patients with GAD (13 males and nine females) diagnosed using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) and 22 age-matched healthy controls (13 males and nine females). High-resolution magnetic resonance imaging (MRI) data were processed by voxel-based morphometry (VBM) analysis based on diffeomorphic anatomical registration using the exponentiated Lie algebra (DARTEL) algorithm in SPM8. Patients with GAD showed significantly reduced WM volume, particularly in the dorsolateral prefrontal cortex (DLPFC), anterior limb of the internal capsule (ALIC), and midbrain. In addition, DLPFC volume was negatively correlated with GAD-7 score and illness duration. ALIC volume was negatively correlated with GAD-7 score. Female patients had significantly less orbitofrontal cortex volume compared to that in male patients. The findings demonstrate localized changes in WM volume associated with cognitive and emotional dysfunction in patients with GAD. The finding will be helpful for understanding the neuropathology in patients with GAD. (orig.)
Hasugian, L.; Hanum, H.; Hanida, W.; Safri, Z.
2018-03-01
Patients with Depression and the acute coronary syndrome (ACS) is rarely detected, although in some studies say that depression can worsen cardiovascularly and increase mortality. From research, Canan F et al found that increasing levels of Mean platelet volume (MPV) as a risk factor for atherosclerosis and MPV was higher in patients with depression compared with patients without depression. In this study used observational methods of measurement of cross-sectional data. Research began in November 2015 - May 2016 against General Hospital inpatients H. Adam Malik Medan. There are 64 patients with a diagnosis of ACS were given quieter Beck Depression Inventory (BDI), then calculated a score of BDI patients and MPV levels were seen when they first entered the hospital before being given treatment. Patients answered quieter on days 3-7 after diagnosis ACS. ACS Patients were divided into 3 groups: acute myocardial infarction with ST elevation, acute myocardial infarction with non-ST elevation and unstable angina pectoris. The level of depression is grouped into not depression, mild depression, moderate depression and severe depression. Statistically significant with p-value<0.05Based on the linear correlation analysis, it was found a positive correlation with r=0.542. And the relationship is statistically significant with p-value 0.000003.
SLE as a Mating of Trees in Euclidean Geometry
Holden, Nina; Sun, Xin
2018-05-01
The mating of trees approach to Schramm-Loewner evolution (SLE) in the random geometry of Liouville quantum gravity (LQG) has been recently developed by Duplantier et al. (Liouville quantum gravity as a mating of trees, 2014. arXiv:1409.7055). In this paper we consider the mating of trees approach to SLE in Euclidean geometry. Let {η} be a whole-plane space-filling SLE with parameter {κ > 4} , parameterized by Lebesgue measure. The main observable in the mating of trees approach is the contour function, a two-dimensional continuous process describing the evolution of the Minkowski content of the left and right frontier of {η} . We prove regularity properties of the contour function and show that (as in the LQG case) it encodes all the information about the curve {η} . We also prove that the uniform spanning tree on {Z^2} converges to SLE8 in the natural topology associated with the mating of trees approach.
Complex networks in the Euclidean space of communicability distances
Estrada, Ernesto
2012-06-01
We study the properties of complex networks embedded in a Euclidean space of communicability distances. The communicability distance between two nodes is defined as the difference between the weighted sum of walks self-returning to the nodes and the weighted sum of walks going from one node to the other. We give some indications that the communicability distance identifies the least crowded routes in networks where simultaneous submission of packages is taking place. We define an index Q based on communicability and shortest path distances, which allows reinterpreting the “small-world” phenomenon as the region of minimum Q in the Watts-Strogatz model. It also allows the classification and analysis of networks with different efficiency of spatial uses. Consequently, the communicability distance displays unique features for the analysis of complex networks in different scenarios.
Reduction of product platform complexity by vectorial Euclidean algorithm
International Nuclear Information System (INIS)
Navarrete, Israel Aguilera; Guzman, Alejandro A. Lozano
2013-01-01
In traditional machine, equipment and devices design, technical solutions are practically independent, thus increasing designs cost and complexity. Overcoming this situation has been tackled just using designer's experience. In this work, a product platform complexity reduction is presented based on a matrix representation of technical solutions versus product properties. This matrix represents the product platform. From this matrix, the Euclidean distances among technical solutions are obtained. Thus, the vectorial distances among technical solutions are identified in a new matrix of order of the number of technical solutions identified. This new matrix can be reorganized in groups with a hierarchical structure, in such a way that modular design of products is now more tractable. As a result of this procedure, the minimum vector distances are found thus being possible to identify the best technical solutions for the design problem raised. Application of these concepts is shown with two examples.
Curvature-driven morphing of non-Euclidean shells
Pezzulla, Matteo; Stoop, Norbert; Jiang, Xin; Holmes, D. P.
2017-05-01
We investigate how thin structures change their shape in response to non-mechanical stimuli that can be interpreted as variations in the structure's natural curvature. Starting from the theory of non-Euclidean plates and shells, we derive an effective model that reduces a three-dimensional stimulus to the natural fundamental forms of the mid-surface of the structure, incorporating expansion, or growth, in the thickness. Then, we apply the model to a variety of thin bodies, from flat plates to spherical shells, obtaining excellent agreement between theory and numerics. We show how cylinders and cones can either bend more or unroll, and eventually snap and rotate. We also study the nearly isometric deformations of a spherical shell and describe how this shape change is ruled by the geometry of a spindle. As the derived results stem from a purely geometrical model, they are general and scalable.
Buckling transition and boundary layer in non-Euclidean plates.
Efrati, Efi; Sharon, Eran; Kupferman, Raz
2009-07-01
Non-Euclidean plates are thin elastic bodies having no stress-free configuration, hence exhibiting residual stresses in the absence of external constraints. These bodies are endowed with a three-dimensional reference metric, which may not necessarily be immersible in physical space. Here, based on a recently developed theory for such bodies, we characterize the transition from flat to buckled equilibrium configurations at a critical value of the plate thickness. Depending on the reference metric, the buckling transition may be either continuous or discontinuous. In the infinitely thin plate limit, under the assumption that a limiting configuration exists, we show that the limit is a configuration that minimizes the bending content, among all configurations with zero stretching content (isometric immersions of the midsurface). For small but finite plate thickness, we show the formation of a boundary layer, whose size scales with the square root of the plate thickness and whose shape is determined by a balance between stretching and bending energies.
Defects and boundary layers in non-Euclidean plates
International Nuclear Information System (INIS)
Gemmer, J A; Venkataramani, S C
2012-01-01
We investigate the behaviour of non-Euclidean plates with constant negative Gaussian curvature using the Föppl–von Kármán reduced theory of elasticity. Motivated by recent experimental results, we focus on annuli with a periodic profile. We prove rigorous upper and lower bounds for the elastic energy that scales like the thickness squared. In particular we show that are only two types of global minimizers—deformations that remain flat and saddle shaped deformations with isolated regions of stretching near the edge of the annulus. We also show that there exist local minimizers with a periodic profile that have additional boundary layers near their lines of inflection. These additional boundary layers are a new phenomenon in thin elastic sheets and are necessary to regularize jump discontinuities in the azimuthal curvature across lines of inflection. We rigorously derive scaling laws for the width of these boundary layers as a function of the thickness of the sheet. (paper)
Geometry through history Euclidean, hyperbolic, and projective geometries
Dillon, Meighan I
2018-01-01
Presented as an engaging discourse, this textbook invites readers to delve into the historical origins and uses of geometry. The narrative traces the influence of Euclid’s system of geometry, as developed in his classic text The Elements, through the Arabic period, the modern era in the West, and up to twentieth century mathematics. Axioms and proof methods used by mathematicians from those periods are explored alongside the problems in Euclidean geometry that lead to their work. Students cultivate skills applicable to much of modern mathematics through sections that integrate concepts like projective and hyperbolic geometry with representative proof-based exercises. For its sophisticated account of ancient to modern geometries, this text assumes only a year of college mathematics as it builds towards its conclusion with algebraic curves and quaternions. Euclid’s work has affected geometry for thousands of years, so this text has something to offer to anyone who wants to broaden their appreciation for the...
Euclidean mirrors: enhanced vacuum decay from reflected instantons
Akal, Ibrahim; Moortgat-Pick, Gudrid
2018-05-01
We study the tunnelling of virtual matter–antimatter pairs from the quantum vacuum in the presence of a spatially uniform, time-dependent electric background composed of a strong, slow field superimposed with a weak, rapid field. After analytic continuation to Euclidean spacetime, we obtain from the instanton equations two critical points. While one of them is the closing point of the instanton path, the other serves as an Euclidean mirror which reflects and squeezes the instanton. It is this reflection and shrinking which is responsible for an enormous enhancement of the vacuum pair production rate. We discuss how important features of two different mechanisms can be analysed and understood via such a rotation in the complex plane. (a) Consistent with previous studies, we first discuss the standard assisted mechanism with a static strong field and certain weak fields with a distinct pole structure in order to show that the reflection takes place exactly at the poles. We also discuss the effect of possible sub-cycle structures. We extend this reflection picture then to weak fields which have no poles present and illustrate the effective reflections with explicit examples. An additional field strength dependence for the rate occurs in such cases. We analytically compute the characteristic threshold for the assisted mechanism given by the critical combined Keldysh parameter. We discuss significant differences between these two types of fields. For various backgrounds, we present the contributing instantons and perform analytical computations for the corresponding rates treating both fields nonperturbatively. (b) In addition, we also study the case with a nonstatic strong field which gives rise to the assisted dynamical mechanism. For different strong field profiles we investigate the impact on the critical combined Keldysh parameter. As an explicit example, we analytically compute the rate by employing the exact reflection points. The validity of the predictions
Euclidean mirrors. Enhanced vacuum decay from reflected instantons
Energy Technology Data Exchange (ETDEWEB)
Akal, Ibrahim [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Moortgat-Pick, Gudrid [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik
2017-06-15
We study the tunneling of virtual matter-antimatter pairs from the quantum vacuum in the presence of a spatially uniform temporal electric background composed of of a strong slow field superimposed with a weak rapid field. After analytic continuation to Euclidean spacetime we obtain from the instanton equations two critical points. While one of them is the closing point of the instanton path, the other serves as an Euclidean mirror which reflects and squeezes the instanton. It is this reflection and shrinking which is responsible for an enormous enhancement of the vacuum pair production rate. We discuss how important features of this mechanism can be analysed and understood via such a rotation in the complex plane. Consistent with previous studies, we consider certain examples where we apply weak fields with a distinct pole structure in order to show that the reflection takes place exactly at the poles. We also discuss the effect of possible sub-cycle structures. We extend this reflection picture to fields which have no poles present and illustrate the effective reflections with explicit examples. An additional field strength dependence for the rate occurs in such cases. We analytically compute the characteristic threshold for this mechanism given by the critical combined Keldysh parameter. We discuss significant differences between these two types of fields. For various backgrounds, we present the contributing instantons and perform analytical computations for the corresponding rates treating both fields nonperturbatively. The validity of the results is confirmed by numerical computations. Considering different profiles for the strong field, we also discuss its impact on the critical combined Keldysh parameter.
International Nuclear Information System (INIS)
Pan, Bing; Wu, Dafang; Wang, Zhaoyang
2012-01-01
As a novel tool for quantitative 3D internal deformation measurement throughout the interior of a material or tissue, digital volume correlation (DVC) has increasingly gained attention and application in the fields of experimental mechanics, material research and biomedical engineering. However, the practical implementation of DVC involves important challenges such as implementation complexity, calculation accuracy and computational efficiency. In this paper, a least-squares framework is presented for 3D internal displacement and strain field measurement using DVC. The proposed DVC combines a practical linear-intensity-change model with an easy-to-implement iterative least-squares (ILS) algorithm to retrieve 3D internal displacement vector field with sub-voxel accuracy. Because the linear-intensity-change model is capable of accounting for both the possible intensity changes and the relative geometric transform of the target subvolume, the presented DVC thus provides the highest sub-voxel registration accuracy and widest applicability. Furthermore, as the ILS algorithm uses only first-order spatial derivatives of the deformed volumetric image, the developed DVC thus significantly reduces computational complexity. To further extract 3D strain distributions from the 3D discrete displacement vectors obtained by the ILS algorithm, the presented DVC employs a pointwise least-squares algorithm to estimate the strain components for each measurement point. Computer-simulated volume images with controlled displacements are employed to investigate the performance of the proposed DVC method in terms of mean bias error and standard deviation error. Results reveal that the present technique is capable of providing accurate measurements in an easy-to-implement manner, and can be applied to practical 3D internal displacement and strain calculation. (paper)
Does acid-base equilibrium correlate with remnant liver volume during stepwise liver resection?
Golriz, Mohammad; Abbasi, Sepehr; Fathi, Parham; Majlesara, Ali; Brenner, Thorsten; Mehrabi, Arianeb
2017-10-01
Small for size and flow syndrome (SFSF) is one of the most challenging complications following extended hepatectomy (EH). After EH, hepatic artery flow decreases and portal vein flow increases per 100 g of remnant liver volume (RLV). This causes hypoxia followed by metabolic acidosis. A correlation between acidosis and posthepatectomy liver failure has been postulated but not studied systematically in a large animal model or clinical setting. In our study, we performed stepwise liver resections on nine pigs to defined SFSF limits as follows: step 1: segment II/III resection, step 2: segment IV resection, step 3: segment V/VIII resection (RLV: 75, 50, and 25%, respectively). Blood gas values were measured before and after each step using four catheters inserted into the carotid artery, internal jugular vein, hepatic artery, and portal vein. The pH, [Formula: see text], and base excess (BE) decreased, but [Formula: see text] values increased after 75% resection in the portal and jugular veins. EH correlated with reduced BE in the hepatic artery. Pco 2 values increased after 75% resection in the jugular vein. In contrast, arterial Po 2 increased after every resection, whereas the venous Po 2 decreased slightly. There were differences in venous [Formula: see text], BE in the hepatic artery, and Pco 2 in the jugular vein after 75% liver resection. Because 75% resection is the limit for SFSF, these noninvasive blood evaluations may be used to predict SFSF. Further studies with long-term follow-up are required to validate this correlation. NEW & NOTEWORTHY This is the first study to evaluate acid-base parameters in major central and hepatic vessels during stepwise liver resection. The pH, [Formula: see text], and base excess (BE) decreased, but [Formula: see text] values increased after 75% resection in the portal and jugular veins. Extended hepatectomy correlated with reduced BE in the hepatic artery. Because 75% resection is the limit for small for size and flow
Three Dimensional Fast Exact Euclidean Distance (3D-FEED) Maps
Latecki, L.J.; Schouten, Theo E.; Mount, D.M.; Kuppens, Harco C.; Wu, A.Y.; van den Broek, Egon
2006-01-01
In image and video analysis, distance maps are frequently used. They provide the (Euclidean) distance (ED) of background pixels to the nearest object pixel. Recently, the Fast Exact Euclidean Distance (FEED) transformation was launched. In this paper, we present the three dimensional (3D) version of
Uniqueness of Gibbs states and global Markov property for Euclidean fields
International Nuclear Information System (INIS)
Albeverio, S.; Hoeegh-Krohn, R.
1981-01-01
The authors briefly discuss the proof of the uniqueness of solutions of the DLR equations (uniqueness of Gibbs states) in the class of regular generalized random fields (in the sense of having second moments bounded by those of some Euclidean field), for the Euclidean fields with trigonometric interaction. (Auth.)
Non-euclidean simplex optimization. [Application to potentiometric titration of Pu
Energy Technology Data Exchange (ETDEWEB)
Silver, G.L.
1977-08-15
Geometric optimization techniques useful for studying chemical equilibrium traditionally rely upon principles of euclidean geometry, but such algorithms may also be based upon principles of a non-euclidean geometry. The sequential simplex method is adapted to the hyperbolic plane, and application of optimization to problems such as the potentiometric titration of plutonium is suggested.
Squared Euclidean distance: a statistical test to evaluate plant community change
Raymond D. Ratliff; Sylvia R. Mori
1993-01-01
The concepts and a procedure for evaluating plant community change using the squared Euclidean distance (SED) resemblance function are described. Analyses are based on the concept that Euclidean distances constitute a sample from a population of distances between sampling units (SUs) for a specific number of times and SUs. With different times, the distances will be...
Testosterone and dihydrotestosterone levels in the transition zone correlate with prostate volume.
Pejčić, Tomislav; Tosti, Tomislav; Tešić, Živoslav; Milković, Borivoj; Dragičević, Dejan; Kozomara, Milutin; Čekerevac, Milica; Džamić, Zoran
2017-07-01
There is still no consensus regarding intraprostatic androgen levels and the accumulation of androgens in the hyperplastic prostatic tissue. The current opinion is that intraprostatic dihydrotestosterone (DHT) concentrations are maintained but not elevated in benign prostatic hyperplasia (BPH), while there is no similar data concerning intraprostatic testosterone (T). Tissue T (tT) and tissue DHT (tDHT) concentration were determined in 93 patients scheduled for initial prostate biopsy. The criteria for biopsy were abnormal DRE and/or PSA > 4 ng/mL. Total prostate volume (TPV) was determined by transrectal ultrasound (TRUS). During TRUS- guided prostate biopsy, 10-12 samples were collected from the peripheral zone (PZ) and two additional samples were collected from the transition zone (TZ). The samples from the TZ were immediately frozen in liquid nitrogen at -70°C, and transported for tissue androgen determination, using liquid chromatography mass spectrometry (LC-MS). Pathological analysis revealed that prostate cancer (PCa) was present in 45 and absent in 48 patients. In the whole group, there were 42 men with small prostate (TPV prostate (TPV ≥ 31 mL). The overall average tT level was 0.79 ± 0.66 ng/g, while the average tDHT level was 10.27 ± 7.15 ng/g. There were no differences in tT and tDHT level in prostates with and without PCa. However, tT and tDHT levels were significantly higher in larger, than in smaller prostates (tT: 1.05 ± 0.75 and 0.46 ± 0.29 ng/g, and tDHT: 15.0 ± 6.09 and 4.51 ± 2.75 ng/g, respectively). There were strong correlations between tT and TPV (r = 0.71), and tDHT and TPV (r = 0.74). The present study confirmed that both T and DHT accumulated in the stroma of enlarged prostates; the degree of accumulation correlated with prostate volume. © 2017 Wiley Periodicals, Inc.
Finite volume gauge theory partition functions in three dimensions
International Nuclear Information System (INIS)
Szabo, Richard J.
2005-01-01
We determine the fermion mass dependence of Euclidean finite volume partition functions for three-dimensional QCD in the ε-regime directly from the effective field theory of the pseudo-Goldstone modes by using zero-dimensional non-linear σ-models. New results are given for an arbitrary number of flavours in all three cases of complex, pseudo-real and real fermions, extending some previous considerations based on random matrix theory. They are used to describe the microscopic spectral correlation functions and smallest eigenvalue distributions of the QCD 3 Dirac operator, as well as the corresponding massive spectral sum rules
International Nuclear Information System (INIS)
Panigrahy, Ashok; Barnes, Patrick D.; Robertson, Robert L.; Sleeper, Lynn A.; Sayre, James W.
2005-01-01
This study was conducted to quantitatively correlate the thickness of the corpus callosum with the volume of cerebral white matter in children with cerebral palsy and developmental delay. Material and methods: A clinical database of 70 children with cerebral palsy and developmental delay was established with children between the ages of 1 and 5 years. These children also demonstrated abnormal periventricular T2 hyperintensities associated with and without ventriculomegaly. Mid-sagittal T1-weighted images were used to measure the thickness (genu, mid-body, and splenium) and length of the corpus callosum. Volumes of interest were digitized based on gray-scale densities to define the hemispheric cerebral white matter on axial T2-weighted and FLAIR images. The thickness of the mid-body of the corpus callosum was correlated with cerebral white matter volume. Subgroup analysis was also performed to examine the relationship of this correlation with both gestational age and neuromotor outcome. Statistical analysis was performed using analysis of variance and Pearson correlation coefficients. There was a positive correlation between the thickness of the mid-body of the corpus callosum and the volume of cerebral white matter across all children studied (R=0.665, P=0.0001). This correlation was not dependent on gestational age. The thickness of the mid-body of the corpus callosum was decreased in the spastic diplegia group compared to the two other groups (hypotonia and developmental delay only; P<0.0001). Within each neuromotor subgroup, there was a positive correlation between thickness of the mid-body of the corpus callosum and volume of the cerebral white matter. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Panigrahy, Ashok [Childrens Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); Barnes, Patrick D. [Stanford University Medical Center, Department of Radiology, Lucile Salter Packard Children' s Hospital, Palo Alto, CA (United States); Robertson, Robert L. [Children' s Hospital Boston, Department of Radiology, Boston, MA (United States); Sleeper, Lynn A. [New England Research Institute, Watertown, MA (United States); Sayre, James W. [UCLA Medical Center, Departments of Radiology and Biostatistics, Los Angeles, CA (United States)
2005-12-01
This study was conducted to quantitatively correlate the thickness of the corpus callosum with the volume of cerebral white matter in children with cerebral palsy and developmental delay. Material and methods: A clinical database of 70 children with cerebral palsy and developmental delay was established with children between the ages of 1 and 5 years. These children also demonstrated abnormal periventricular T2 hyperintensities associated with and without ventriculomegaly. Mid-sagittal T1-weighted images were used to measure the thickness (genu, mid-body, and splenium) and length of the corpus callosum. Volumes of interest were digitized based on gray-scale densities to define the hemispheric cerebral white matter on axial T2-weighted and FLAIR images. The thickness of the mid-body of the corpus callosum was correlated with cerebral white matter volume. Subgroup analysis was also performed to examine the relationship of this correlation with both gestational age and neuromotor outcome. Statistical analysis was performed using analysis of variance and Pearson correlation coefficients. There was a positive correlation between the thickness of the mid-body of the corpus callosum and the volume of cerebral white matter across all children studied (R=0.665, P=0.0001). This correlation was not dependent on gestational age. The thickness of the mid-body of the corpus callosum was decreased in the spastic diplegia group compared to the two other groups (hypotonia and developmental delay only; P<0.0001). Within each neuromotor subgroup, there was a positive correlation between thickness of the mid-body of the corpus callosum and volume of the cerebral white matter. (orig.)
Accurate B-spline-based 3-D interpolation scheme for digital volume correlation
Ren, Maodong; Liang, Jin; Wei, Bin
2016-12-01
An accurate and efficient 3-D interpolation scheme, based on sampling theorem and Fourier transform technique, is proposed to reduce the sub-voxel matching error caused by intensity interpolation bias in digital volume correlation. First, the influence factors of the interpolation bias are investigated theoretically using the transfer function of an interpolation filter (henceforth filter) in the Fourier domain. A law that the positional error of a filter can be expressed as a function of fractional position and wave number is found. Then, considering the above factors, an optimized B-spline-based recursive filter, combining B-spline transforms and least squares optimization method, is designed to virtually eliminate the interpolation bias in the process of sub-voxel matching. Besides, given each volumetric image containing different wave number ranges, a Gaussian weighting function is constructed to emphasize or suppress certain of wave number ranges based on the Fourier spectrum analysis. Finally, a novel software is developed and series of validation experiments were carried out to verify the proposed scheme. Experimental results show that the proposed scheme can reduce the interpolation bias to an acceptable level.
Thermal error analysis and compensation for digital image/volume correlation
Pan, Bing
2018-02-01
Digital image/volume correlation (DIC/DVC) rely on the digital images acquired by digital cameras and x-ray CT scanners to extract the motion and deformation of test samples. Regrettably, these imaging devices are unstable optical systems, whose imaging geometry may undergo unavoidable slight and continual changes due to self-heating effect or ambient temperature variations. Changes in imaging geometry lead to both shift and expansion in the recorded 2D or 3D images, and finally manifest as systematic displacement and strain errors in DIC/DVC measurements. Since measurement accuracy is always the most important requirement in various experimental mechanics applications, these thermal-induced errors (referred to as thermal errors) should be given serious consideration in order to achieve high accuracy, reproducible DIC/DVC measurements. In this work, theoretical analyses are first given to understand the origin of thermal errors. Then real experiments are conducted to quantify thermal errors. Three solutions are suggested to mitigate or correct thermal errors. Among these solutions, a reference sample compensation approach is highly recommended because of its easy implementation, high accuracy and in-situ error correction capability. Most of the work has appeared in our previously published papers, thus its originality is not claimed. Instead, this paper aims to give a comprehensive overview and more insights of our work on thermal error analysis and compensation for DIC/DVC measurements.
An efficient and accurate 3D displacements tracking strategy for digital volume correlation
Pan, Bing
2014-07-01
Owing to its inherent computational complexity, practical implementation of digital volume correlation (DVC) for internal displacement and strain mapping faces important challenges in improving its computational efficiency. In this work, an efficient and accurate 3D displacement tracking strategy is proposed for fast DVC calculation. The efficiency advantage is achieved by using three improvements. First, to eliminate the need of updating Hessian matrix in each iteration, an efficient 3D inverse compositional Gauss-Newton (3D IC-GN) algorithm is introduced to replace existing forward additive algorithms for accurate sub-voxel displacement registration. Second, to ensure the 3D IC-GN algorithm that converges accurately and rapidly and avoid time-consuming integer-voxel displacement searching, a generalized reliability-guided displacement tracking strategy is designed to transfer accurate and complete initial guess of deformation for each calculation point from its computed neighbors. Third, to avoid the repeated computation of sub-voxel intensity interpolation coefficients, an interpolation coefficient lookup table is established for tricubic interpolation. The computational complexity of the proposed fast DVC and the existing typical DVC algorithms are first analyzed quantitatively according to necessary arithmetic operations. Then, numerical tests are performed to verify the performance of the fast DVC algorithm in terms of measurement accuracy and computational efficiency. The experimental results indicate that, compared with the existing DVC algorithm, the presented fast DVC algorithm produces similar precision and slightly higher accuracy at a substantially reduced computational cost. © 2014 Elsevier Ltd.
An efficient and accurate 3D displacements tracking strategy for digital volume correlation
Pan, Bing; Wang, Bo; Wu, Dafang; Lubineau, Gilles
2014-07-01
Owing to its inherent computational complexity, practical implementation of digital volume correlation (DVC) for internal displacement and strain mapping faces important challenges in improving its computational efficiency. In this work, an efficient and accurate 3D displacement tracking strategy is proposed for fast DVC calculation. The efficiency advantage is achieved by using three improvements. First, to eliminate the need of updating Hessian matrix in each iteration, an efficient 3D inverse compositional Gauss-Newton (3D IC-GN) algorithm is introduced to replace existing forward additive algorithms for accurate sub-voxel displacement registration. Second, to ensure the 3D IC-GN algorithm that converges accurately and rapidly and avoid time-consuming integer-voxel displacement searching, a generalized reliability-guided displacement tracking strategy is designed to transfer accurate and complete initial guess of deformation for each calculation point from its computed neighbors. Third, to avoid the repeated computation of sub-voxel intensity interpolation coefficients, an interpolation coefficient lookup table is established for tricubic interpolation. The computational complexity of the proposed fast DVC and the existing typical DVC algorithms are first analyzed quantitatively according to necessary arithmetic operations. Then, numerical tests are performed to verify the performance of the fast DVC algorithm in terms of measurement accuracy and computational efficiency. The experimental results indicate that, compared with the existing DVC algorithm, the presented fast DVC algorithm produces similar precision and slightly higher accuracy at a substantially reduced computational cost.
Epicardial fat volume is correlated with coronary lesion and its severity.
Bo, Xiaohong; Ma, Likun; Fan, Jili; Jiang, Zhe; Zhou, Yuansong; Zhang, Lei; Li, Wanjun
2015-01-01
To evaluate the correlation of epicardial adipose tissue volume (EATV) with the coronary artery lesion and its severity. Inpatients with suspicious stable angina of coronary heart lesion were recruited. For patients with coronary artery lesions in CTA, further coronary angiography (CAG) was performed to evaluate the coronary artery lesion. Gensini scoring system was employed to assess the severity of coronary artery lesions. Patients were classified as coronary heart disease (CHD) group (n = 160). Results showed the mean EATV was 192.57 ± 30.32 cm(3) in CHD group, which was significantly larger than that in control group (138.56 ± 23.18 cm(3); P EATV among patients with different severities of coronary artery stenosis (P EATV (r = 0.285, P = 0.000). The EATV increased with the increase in the number of affected coronary arteries. Multivariate Logistic regression analysis showed EATV was an independent risk factor of CHD after adjusting other confounding factors (OR = 1.023, P = 0.013). EATV is closely related to the severity of coronary artery lesions: the larger the EATV, the more severe the coronary artery lesions. Moreover, EATV is an independent risk factor of CHD.
Correlation of neurocognitive function and brain parenchyma volumes in children surviving cancer
Reddick, Wilburn E.; White, Holly A.; Glass, John O.; Mulhern, Raymond K.
2002-04-01
This research builds on our hypothesis that white matter damage and associated neurocognitive symptoms, in children treated for cancer with cranial spinal irradiation, spans a continuum of severity that can be reliably probed using non-invasive MR technology. Quantitative volumetric assessments of MR imaging and psychological assessments were obtained in 40 long-term survivors of malignant brain tumors treated with cranial irradiation. Neurocognitive assessments included a test of intellect (Wechsler Intelligence Test for Children, Wechsler Adult Intelligence Scale), attention (Conner's Continuous Performance Test), and memory (California Verbal Learning Test). One-sample t-tests were conducted to evaluate test performance of survivors against age-adjusted scores from the test norms; these analyses revealed significant impairments in all apriori selected measures of intelligence, attention, and memory. Partial correlation analyses were performed to assess the relationships between brain tissues volumes (normal appearing white matter (NAWM), gray matter, and CSF) and neurocognitive function. Global intelligence (r = 0.32, p = 0.05) and global attentional (r = 0.49, p attentional deficits, whereas overall parenchyma loss, as reflected by increased CSF and decreased white matter, is associated with memory-related deficits.
International Nuclear Information System (INIS)
Apostolova, Ivayla; Ego, Kilian; Steffen, Ingo G.; Buchert, Ralph; Wertzel, Heinz; Achenbach, H.J.; Riedel, Sandra; Schreiber, Jens; Schultz, Meinald; Furth, Christian; Amthauer, Holger; Derlin, Thorsten; Hofheinz, Frank; Kalinski, Thomas
2016-01-01
Asphericity (ASP) is a tumour shape descriptor based on the PET image. It quantitates the deviation from spherical of the shape of the metabolic tumour volume (MTV). In order to identify its biological correlates, we investigated the relationship between ASP and clinically relevant histopathological and molecular signatures in non-small-cell lung cancer (NSCLC). The study included 83 consecutive patients (18 women, aged 66.4 ± 8.9 years) with newly diagnosed NSCLC in whom PET/CT with 18 F-FDG had been performed prior to therapy. Primary tumour resection specimens and core biopsies were used for basic histopathology and determination of the Ki-67 proliferation index. EGFR status, VEGF, p53 and ALK expression were obtained in a subgroup of 44 patients. The FDG PET images of the primary tumours were delineated using an automatic algorithm based on adaptive thresholding taking into account local background. In addition to ASP, SUVmax, MTV and some further descriptors of shape and intratumour heterogeneity were assessed as semiquantitative PET measures. SUVmax, MTV and ASP were associated with pathological T stage (Kruskal-Wallis, p = 0.001, p < 0.0005 and p < 0.0005, respectively) and N stage (p = 0.017, p = 0.003 and p = 0.002, respectively). Only ASP was associated with M stage (p = 0.026). SUVmax, MTV and ASP were correlated with Ki-67 index (Spearman's rho = 0.326/p = 0.003, rho = 0.302/p = 0.006 and rho = 0.271/p = 0.015, respectively). The latter correlations were considerably stronger in adenocarcinomas than in squamous cell carcinomas. ASP, but not SUVmax or MTV, showed a tendency for a significant association with the extent of VEGF expression (p = 0.058). In multivariate Cox regression analysis, ASP (p < 0.0005) and the presence of distant metastases (p = 0.023) were significantly associated with progression-free survival. ASP (p = 0.006), the presence of distant metastases (p = 0.010), and Ki-67 index (p = 0.062) were significantly associated with
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Zheng, Feng-Yang, E-mail: fyzheng16@fudan.edu.cn [Department of Ultrasound, Zhongshan Hospital, Fudan University, Shanghai 200032 (China); Shanghai Institute of Medical Imaging, Shanghai 200032 (China); Lu, Qing, E-mail: lu.qing@zs-hospital.sh.cn [Department of Ultrasound, Zhongshan Hospital, Fudan University, Shanghai 200032 (China); Huang, Bei-Jian, E-mail: huang.beijian@zs-hospital.sh.cn [Department of Ultrasound, Zhongshan Hospital, Fudan University, Shanghai 200032 (China); Shanghai Institute of Medical Imaging, Shanghai 200032 (China); Xia, Han-Sheng, E-mail: zs12036@126.com [Department of Ultrasound, Zhongshan Hospital, Fudan University, Shanghai 200032 (China); Yan, Li-Xia, E-mail: dndyanlixia@163.com [Department of Ultrasound, Zhongshan Hospital, Fudan University, Shanghai 200032 (China); Wang, Xi, E-mail: wang.xi@zs-hospital.sh.cn [Department of Ultrasound, Zhongshan Hospital, Fudan University, Shanghai 200032 (China); Shanghai Institute of Medical Imaging, Shanghai 200032 (China); Yuan, Wei, E-mail: yuan.wei@zs-hospital.sh.cn [Department of Pathology, Zhongshan Hospital, Fudan University, Shanghai 200032 (China); Wang, Wen-Ping, E-mail: wang.wenping@zs-hospital.sh.cn [Department of Ultrasound, Zhongshan Hospital, Fudan University, Shanghai 200032 (China); Shanghai Institute of Medical Imaging, Shanghai 200032 (China)
2017-01-15
Highlights: • ABVS imaging features have a strong correlation with breast cancer molecular subtypes. • Retraction phenomenon on the coronal planes was the most important predictor for Luminal A and Triple Negative subtypes. • ABVS expand the scope of ultrasound in identifying breast cancer molecular subtypes. - Abstract: Objectives: To investigate the correlation between the imaging features obtained by an automated breast volume scanner (ABVS) and molecular subtypes of breast cancer. Methods: We examined 303 malignant breast tumours by ABVS for specific imaging features and by immunohistochemical analysis to determine the molecular subtype. ABVS imaging features, including retraction phenomenon, shape, margins, echogenicity, post-acoustic features, echogenic halo, and calcifications were analysed by univariate and multivariate logistic regression analyses to determine the significant predictive factors of the molecular subtypes. Results: By univariate logistic regression analysis, the predictive factors of the Luminal-A subtype (n = 128) were retraction phenomenon (odds ratio [OR] = 10.188), post-acoustic shadowing (OR = 5.112), and echogenic halo (OR = 3.263, P < 0.001). The predictive factors of the Human-epidermal-growth-factor-receptor-2-amplified subtype (n = 39) were calcifications (OR = 6.210), absence of retraction phenomenon (OR = 4.375), non-mass lesions (OR = 4.286, P < 0.001), absence of echogenic halo (OR = 3.851, P = 0.035), and post-acoustic enhancement (OR = 3.641, P = 0.008). The predictors for the Triple-Negative subtype (n = 47) were absence of retraction phenomenon (OR = 5.884), post-acoustic enhancement (OR = 5.255, P < 0.001), absence of echogenic halo (OR = 4.138, P = 0.002), and absence of calcifications (OR = 3.363, P = 0.001). Predictors for the Luminal-B subtype (n = 89) had a relatively lower association (OR ≤ 2.328). By multivariate logistic regression analysis, retraction phenomenon was the strongest independent predictor for
International Nuclear Information System (INIS)
Zheng, Feng-Yang; Lu, Qing; Huang, Bei-Jian; Xia, Han-Sheng; Yan, Li-Xia; Wang, Xi; Yuan, Wei; Wang, Wen-Ping
2017-01-01
Highlights: • ABVS imaging features have a strong correlation with breast cancer molecular subtypes. • Retraction phenomenon on the coronal planes was the most important predictor for Luminal A and Triple Negative subtypes. • ABVS expand the scope of ultrasound in identifying breast cancer molecular subtypes. - Abstract: Objectives: To investigate the correlation between the imaging features obtained by an automated breast volume scanner (ABVS) and molecular subtypes of breast cancer. Methods: We examined 303 malignant breast tumours by ABVS for specific imaging features and by immunohistochemical analysis to determine the molecular subtype. ABVS imaging features, including retraction phenomenon, shape, margins, echogenicity, post-acoustic features, echogenic halo, and calcifications were analysed by univariate and multivariate logistic regression analyses to determine the significant predictive factors of the molecular subtypes. Results: By univariate logistic regression analysis, the predictive factors of the Luminal-A subtype (n = 128) were retraction phenomenon (odds ratio [OR] = 10.188), post-acoustic shadowing (OR = 5.112), and echogenic halo (OR = 3.263, P < 0.001). The predictive factors of the Human-epidermal-growth-factor-receptor-2-amplified subtype (n = 39) were calcifications (OR = 6.210), absence of retraction phenomenon (OR = 4.375), non-mass lesions (OR = 4.286, P < 0.001), absence of echogenic halo (OR = 3.851, P = 0.035), and post-acoustic enhancement (OR = 3.641, P = 0.008). The predictors for the Triple-Negative subtype (n = 47) were absence of retraction phenomenon (OR = 5.884), post-acoustic enhancement (OR = 5.255, P < 0.001), absence of echogenic halo (OR = 4.138, P = 0.002), and absence of calcifications (OR = 3.363, P = 0.001). Predictors for the Luminal-B subtype (n = 89) had a relatively lower association (OR ≤ 2.328). By multivariate logistic regression analysis, retraction phenomenon was the strongest independent predictor for
Energy Technology Data Exchange (ETDEWEB)
Apostolova, Ivayla; Ego, Kilian; Steffen, Ingo G. [University Hospital, Otto-von-Guericke University Magdeburg, Clinic of Radiology and Nuclear Medicine, Magdeburg (Germany); Buchert, Ralph [University Medicine Charite, Clinic of Nuclear Medicine, Berlin (Germany); Wertzel, Heinz; Achenbach, H.J. [Lung Clinic Lostau GmbH, Lostau (Germany); Riedel, Sandra; Schreiber, Jens [University Hospital, Otto-von-Guericke University Magdeburg, Clinic of Pneumology, Magdeburg (Germany); Schultz, Meinald [Institute of Pathology Stendal, Stendal (Germany); Furth, Christian; Amthauer, Holger [University Hospital, Otto-von-Guericke University Magdeburg, Clinic of Radiology and Nuclear Medicine, Magdeburg (Germany); University Medicine Charite, Clinic of Nuclear Medicine, Berlin (Germany); Derlin, Thorsten [Hannover Medical School, Department of Nuclear Medicine, Hannover (Germany); Hofheinz, Frank [Helmholtz-Center Dresden-Rossendorf, Dresden (Germany); Kalinski, Thomas [University Hospital Magdeburg, Otto-von-Guericke University Magdeburg, Institute for Pathology, Magdeburg (Germany); Institute for Pathology Lademannbogen, Hamburg (Germany)
2016-12-15
Asphericity (ASP) is a tumour shape descriptor based on the PET image. It quantitates the deviation from spherical of the shape of the metabolic tumour volume (MTV). In order to identify its biological correlates, we investigated the relationship between ASP and clinically relevant histopathological and molecular signatures in non-small-cell lung cancer (NSCLC). The study included 83 consecutive patients (18 women, aged 66.4 ± 8.9 years) with newly diagnosed NSCLC in whom PET/CT with {sup 18}F-FDG had been performed prior to therapy. Primary tumour resection specimens and core biopsies were used for basic histopathology and determination of the Ki-67 proliferation index. EGFR status, VEGF, p53 and ALK expression were obtained in a subgroup of 44 patients. The FDG PET images of the primary tumours were delineated using an automatic algorithm based on adaptive thresholding taking into account local background. In addition to ASP, SUVmax, MTV and some further descriptors of shape and intratumour heterogeneity were assessed as semiquantitative PET measures. SUVmax, MTV and ASP were associated with pathological T stage (Kruskal-Wallis, p = 0.001, p < 0.0005 and p < 0.0005, respectively) and N stage (p = 0.017, p = 0.003 and p = 0.002, respectively). Only ASP was associated with M stage (p = 0.026). SUVmax, MTV and ASP were correlated with Ki-67 index (Spearman's rho = 0.326/p = 0.003, rho = 0.302/p = 0.006 and rho = 0.271/p = 0.015, respectively). The latter correlations were considerably stronger in adenocarcinomas than in squamous cell carcinomas. ASP, but not SUVmax or MTV, showed a tendency for a significant association with the extent of VEGF expression (p = 0.058). In multivariate Cox regression analysis, ASP (p < 0.0005) and the presence of distant metastases (p = 0.023) were significantly associated with progression-free survival. ASP (p = 0.006), the presence of distant metastases (p = 0.010), and Ki-67 index (p = 0.062) were significantly associated with
A general Euclidean connection for so(n,m) lie algebra and the algebraic approach to scattering
International Nuclear Information System (INIS)
Ionescu, R.A.
1994-11-01
We obtain a general Euclidean connection for so(n,m). This Euclidean connection allows an algebraic derivation of the S matrix and it reduces to the known one in suitable circumstances. (author). 8 refs
McAlonan, G. M.; Cheung, V.; Chua, S. E.; Oosterlaan, J.; Hung, S.; Tang, C.; Lee, C.; Kwong, S.; Ho, T.; Cheung, C.; Suckling, J.; Leung, P. W. L.
2009-01-01
Background Children with attention-deficit hyperactivity disorder (ADHD) have difficulties with executive function and impulse control which may improve with age. Aims To map the brain correlates of executive function in ADHD and determine age-related changes in reaction times and brain volumes.
Czech Academy of Sciences Publication Activity Database
Krištoufek, Ladislav
2015-01-01
Roč. 428, č. 1 (2015), s. 194-205 ISSN 0378-4371 R&D Projects: GA ČR(CZ) GP14-11402P Institutional support: RVO:67985556 Keywords : Online searches * Google Trends * Long-term memory * Cross-correlations * Volatility * Traded volume Subject RIV: AH - Economics Impact factor: 1.785, year: 2015 http://library.utia.cas.cz/separaty/2015/E/kristoufek-0452317.pdf
SU-E-J-249: Correlation of Mean Lung Ventilation Value with Ratio of Total Lung Volumes
International Nuclear Information System (INIS)
Yu, N; Qu, H; Xia, P
2014-01-01
Purpose: Lung ventilation function measured from 4D-CT and from breathing correlated CT images is a novel concept to incorporate the lung physiologic function into treatment planning of radiotherapy. The calculated ventilation functions may vary from different breathing patterns, affecting evaluation of the treatment plans. The purpose of this study is to correlate the mean lung ventilation value with the ratio of the total lung volumes obtained from the relevant CTs. Methods: A ventilation map was calculated from the variations of voxel-to-voxel CT densities from two breathing phases from either 4D-CT or breathing correlated CTs. An open source image registration tool of Plastimatch was used to deform the inhale phase images to the exhale phase images. To calculate the ventilation map inside lung, the whole lung was delineated and the tissue outside the lung was masked out. With a software tool developed in house, the 3D ventilation map was then converted in the DICOM format associated with the planning CT images. The ventilation map was analyzed on a clinical workstation. To correlate ventilation map thus calculated with lung volume change, the total lung volume change was compared the mean ventilation from our method. Results: Twenty two patients who underwent stereotactic body irradiation for lung cancer was selected for this retrospective study. For this group of patients, the ratio of lung volumes for the inhale (Vin ) and exhale phase (Vex ) was shown to be linearly related to the mean of the local ventilation (Vent), Vin/Vex=1.+0.49*Vent (R2=0.93, p<0.01). Conclusion: The total lung volume change is highly correlated with the mean of local ventilation. The mean of local ventilation may be useful to assess the patient's lung capacity
Energy Technology Data Exchange (ETDEWEB)
Yoneshima, Manabu; Sawabu, Norio; Toya, Daishu
1984-09-01
Tumor volumes of HCC were measured by CT using planimeter and the clinical value of this measurement was evaluated by comparing several tumor markers. Tumor volumes measured by CT roughly agreed with those measured by angiography. In some cases, volumes from ultrasonography were smaller than those from CT and angiography. Tumor volumes measured by CT correlated significantly with the levels of ..cap alpha..-fetoprotein (AFP) but didn't relate to the presence of hepatoma specific ..gamma..-GTP isoenzyme (novel ..gamma..-GTP) nor to the values and positivities of LAI assay. In small HCCs (<=30 cm/sup 3/), the presence of novel ..gamma..-GTP and the levels of AFP were significantly lower than for larger tumors of HCC, but LAI assay wasn't lower. The non-tumorous volumes and the ratio of the non-tumorous volume to the whole liver volume didn't relate to the tests of liver function except for the presence of ascites.
Microstructural Consequences of Blast Lung Injury Characterized with Digital Volume Correlation
Directory of Open Access Journals (Sweden)
Hari Arora
2017-12-01
Full Text Available This study focuses on microstructural changes that occur within the mammalian lung when subject to blast and how these changes influence strain distributions within the tissue. Shock tube experiments were performed to generate the blast injured specimens (cadaveric Sprague-Dawley rats. Blast overpressures of 100 and 180 kPa were studied. Synchrotron tomography imaging was used to capture volumetric image data of lungs. Specimens were ventilated using a custom-built system to study multiple inflation pressures during each tomography scan. These data enabled the first digital volume correlation (DVC measurements in lung tissue to be performed. Quantitative analysis was performed to describe the damaged architecture of the lung. No clear changes in the microstructure of the tissue morphology were observed due to controlled low- to moderate-level blast exposure. However, significant focal sites of injury were observed using DVC, which allowed the detection of bias and concentration in the patterns of strain level. Morphological analysis corroborated the findings, illustrating that the focal damage caused by a blast can give rise to diffuse influence across the tissue. It is important to characterize the non-instantly fatal doses of blast, given the transient nature of blast lung in the clinical setting. This research has highlighted the need for better understanding of focal injury and its zone of influence (alveolar interdependency and neighboring tissue burden as a result of focal injury. DVC techniques show great promise as a tool to advance this endeavor, providing a new perspective on lung mechanics after blast.
Dynamic hyperbolic geometry: building intuition and understanding mediated by a Euclidean model
Moreno-Armella, Luis; Brady, Corey; Elizondo-Ramirez, Rubén
2018-05-01
This paper explores a deep transformation in mathematical epistemology and its consequences for teaching and learning. With the advent of non-Euclidean geometries, direct, iconic correspondences between physical space and the deductive structures of mathematical inquiry were broken. For non-Euclidean ideas even to become thinkable the mathematical community needed to accumulate over twenty centuries of reflection and effort: a precious instance of distributed intelligence at the cultural level. In geometry education after this crisis, relations between intuitions and geometrical reasoning must be established philosophically, rather than taken for granted. One approach seeks intuitive supports only for Euclidean explorations, viewing non-Euclidean inquiry as fundamentally non-intuitive in nature. We argue for moving beyond such an impoverished approach, using dynamic geometry environments to develop new intuitions even in the extremely challenging setting of hyperbolic geometry. Our efforts reverse the typical direction, using formal structures as a source for a new family of intuitions that emerge from exploring a digital model of hyperbolic geometry. This digital model is elaborated within a Euclidean dynamic geometry environment, enabling a conceptual dance that re-configures Euclidean knowledge as a support for building intuitions in hyperbolic space-intuitions based not directly on physical experience but on analogies extending Euclidean concepts.
Zhang, Luyan; Sun, Xiyu; Yu, Ye; Xiong, Yan; Cui, Yuxin; Wang, Qinmei; Hu, Liang
2016-01-01
To investigate the correlations between corneal sensation, tear meniscus volume, and tear film osmolarity after femtosecond laser-assisted LASIK (FS-LASIK) surgery. In this prospective clinical study, 31 patients undergoing FS-LASIK for myopia were recruited. The upper and lower tear meniscus volumes (UTMV and LTMV) were measured by customized anterior segment optical coherence tomography, tear film osmolarity was measured by a TearLab Osmolarity test device, central corneal sensation was measured by a Cochet-Bonner esthesiometer preoperatively, at 1 week, 1 and 3 months postoperatively. Repeated measures analysis of variance was used to evaluate whether the tear film osmolarity, tear meniscus volume, and corneal sensation were changed after surgery. The correlations between these variables were analyzed by the Pearson correlation analysis. The tear film osmolarity was (310.03 ± 16.48) mOsms/L preoperatively, (323.51 ± 15.92) mOsms/L at 1 week, (319.93 ± 14.27) mOsms/L at 1 month, and (314.97±12.91) mOsms/L at 3 months. The UTMV was (0.42±0.15), (0.25± 0.09), (0.30±0.11), and (0.35±0.09) μL, respectively; the LTMV was (0.60±0.21),(0.37±0.08), (0.44± 0.14), and (0.52±0.17) μL, respectively. The tear film osmolarity was significantly higher at 1 week and 1 month postoperatively compared with the baseline (P=0.001, 0.004), and reduced to the preoperative level at 3 months (P=0.573). The UTMV, LTMV, and corneal sensation values presented significant decreases at all postoperative time points (all Psensation at 1 week after surgery (r=0.356,P=0.005). There were significant correlations between the preoperative LTMV and corneal sensation at 1 week, 1 and 3 months (respectively, r=0.422, 0.366, 0.352;P=0.001, 0.004, 0.006). No significant correlations were found between the tear film osmolarity, tear meniscus volume, and corneal sensation after surgery (all P>0.05). The tear film osmolarity, tear meniscus volume, and corneal sensation became aggravated due
Entropy, extremality, euclidean variations, and the equations of motion
Dong, Xi; Lewkowycz, Aitor
2018-01-01
We study the Euclidean gravitational path integral computing the Rényi entropy and analyze its behavior under small variations. We argue that, in Einstein gravity, the extremality condition can be understood from the variational principle at the level of the action, without having to solve explicitly the equations of motion. This set-up is then generalized to arbitrary theories of gravity, where we show that the respective entanglement entropy functional needs to be extremized. We also extend this result to all orders in Newton's constant G N , providing a derivation of quantum extremality. Understanding quantum extremality for mixtures of states provides a generalization of the dual of the boundary modular Hamiltonian which is given by the bulk modular Hamiltonian plus the area operator, evaluated on the so-called modular extremal surface. This gives a bulk prescription for computing the relative entropies to all orders in G N . We also comment on how these ideas can be used to derive an integrated version of the equations of motion, linearized around arbitrary states.
Non-Euclidean Geometry, Nontrivial Topology and Quantum Vacuum Effects
Directory of Open Access Journals (Sweden)
Yurii A. Sitenko
2018-01-01
Full Text Available Space out of a topological defect of the Abrikosov–Nielsen–Olesen (ANO vortex type is locally flat but non-Euclidean. If a spinor field is quantized in such a space, then a variety of quantum effects are induced in the vacuum. On the basis of the continuum model for long-wavelength electronic excitations originating in the tight-binding approximation for the nearest-neighbor interaction of atoms in the crystal lattice, we consider quantum ground-state effects in Dirac materials with two-dimensional monolayer structures warped into nanocones by a disclination; the nonzero size of the disclination is taken into account, and a boundary condition at the edge of the disclination is chosen to ensure self-adjointness of the Dirac–Weyl Hamiltonian operator. We show that the quantum ground-state effects are independent of the disclination size, and we find circumstances in which they are independent of parameters of the boundary condition.
Biased discriminant euclidean embedding for content-based image retrieval.
Bian, Wei; Tao, Dacheng
2010-02-01
With many potential multimedia applications, content-based image retrieval (CBIR) has recently gained more attention for image management and web search. A wide variety of relevance feedback (RF) algorithms have been developed in recent years to improve the performance of CBIR systems. These RF algorithms capture user's preferences and bridge the semantic gap. However, there is still a big room to further the RF performance, because the popular RF algorithms ignore the manifold structure of image low-level visual features. In this paper, we propose the biased discriminative Euclidean embedding (BDEE) which parameterises samples in the original high-dimensional ambient space to discover the intrinsic coordinate of image low-level visual features. BDEE precisely models both the intraclass geometry and interclass discrimination and never meets the undersampled problem. To consider unlabelled samples, a manifold regularization-based item is introduced and combined with BDEE to form the semi-supervised BDEE, or semi-BDEE for short. To justify the effectiveness of the proposed BDEE and semi-BDEE, we compare them against the conventional RF algorithms and show a significant improvement in terms of accuracy and stability based on a subset of the Corel image gallery.
Euclidean quantum field theory and the Hawking effect
International Nuclear Information System (INIS)
Lapedes, A.S.
1978-01-01
Complex analytic continuation in a time variable in order to define a Feynman propagator is investigated in a general relativistic context. When external electric fields are present a complex analytic continuation in the electric charge is also introduced. The new Euclidean formalism is checked by reproducing Schwinger's special relativistic result for pair creation by an external, homogenous, electric field, and then applied to the Robinson-Bertotti universe. The Robinson-Bertotti universe, although unphysical, provides an interesting theoretical laboratory in which to investigate quantum effects, much as the unphysical Taub-NUT (Newman-Unti-Tamburino) universe does for purely classical general relativity. A conformally related problem of pair creation by a supercritically charged nucleus is also considered, and a sensible resolution is obtained to this classic problem. The essential mathematical point throughout is the use of the Feynman path-integral form of the propagator to motivate replacing hyperbolic equations by elliptic equations. The unique, bounded solution for the elliptic Green's function is then analytically continued back to physical values to define the Feynman Green's function
Euclidean supersymmetric solutions with the self-dual Weyl tensor
Directory of Open Access Journals (Sweden)
Masato Nozawa
2017-07-01
Full Text Available We explore the Euclidean supersymmetric solutions admitting the self-dual gauge field in the framework of N=2 minimal gauged supergravity in four dimensions. According to the classification scheme utilizing the spinorial geometry or the bilinears of Killing spinors, the general solution preserves one quarter of supersymmetry and is described by the Przanowski–Tod class with the self-dual Weyl tensor. We demonstrate that there exists an additional Killing spinor, provided the Przanowski–Tod metric admits a Killing vector that commutes with the principal one. The proof proceeds by recasting the metric into another Przanowski–Tod form. This formalism enables us to show that the self-dual Reissner–Nordström–Taub–NUT–AdS metric possesses a second Killing spinor, which has been missed over many years. We also address the supersymmetry when the Przanowski–Tod space is conformal to each of the self-dual ambi-toric Kähler metrics. It turns out that three classes of solutions are all reduced to the self-dual Carter family, by virtue of the nondegenerate Killing–Yano tensor.
Numerical evaluation of tensor Feynman integrals in Euclidean kinematics
Energy Technology Data Exchange (ETDEWEB)
Gluza, J.; Kajda [Silesia Univ., Katowice (Poland). Inst. of Physics; Riemann, T.; Yundin, V. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)
2010-10-15
For the investigation of higher order Feynman integrals, potentially with tensor structure, it is highly desirable to have numerical methods and automated tools for dedicated, but sufficiently 'simple' numerical approaches. We elaborate two algorithms for this purpose which may be applied in the Euclidean kinematical region and in d=4-2{epsilon} dimensions. One method uses Mellin-Barnes representations for the Feynman parameter representation of multi-loop Feynman integrals with arbitrary tensor rank. Our Mathematica package AMBRE has been extended for that purpose, and together with the packages MB (M. Czakon) or MBresolve (A. V. Smirnov and V. A. Smirnov) one may perform automatically a numerical evaluation of planar tensor Feynman integrals. Alternatively, one may apply sector decomposition to planar and non-planar multi-loop {epsilon}-expanded Feynman integrals with arbitrary tensor rank. We automatized the preparations of Feynman integrals for an immediate application of the package sectordecomposition (C. Bogner and S. Weinzierl) so that one has to give only a proper definition of propagators and numerators. The efficiency of the two implementations, based on Mellin-Barnes representations and sector decompositions, is compared. The computational packages are publicly available. (orig.)
International Nuclear Information System (INIS)
Beseoglu, Kerim; Etminan, Nima; Steiger, Hans-Jakob; Haenggi, Daniel; Turowski, Bernd
2014-01-01
Existing data on perfusion imaging assumes the perihemorrhagic zone (PHZ) in patients with intracerebral hemorrhage (ICH) to be size steady. This study investigates the size of the perihemorrhagic zone (PHZ) in patients with lobar ICH in relation to hematoma volume during the course of treatment using perfusion CT (PCT). The present analysis is based on a previously reported cohort of 20 patients undergoing surgical evacuation for lobar SICH, with pre- and early postoperative PCT scanning. Time to peak of the residue function (T max ) was measured based on the 360 cortical banding method and singular value decomposition. The size of PHZ was determined before and after treatment and correlated with hematoma volume. Preoperative mean hematoma volume constituted 63.0 ml (interquartile ranges (IQR) 39.7-99.4 ml), which correlated significantly (r = 0.563, p = 0.010) with mean PHZ size (5.67 cm, IQR 5.44-8.17 cm). Following a surgical hematoma evacuation, mean hematoma volume was reduced to 2.5 ml IQR 0.0-9.5 ml, which also resulted in a significant reduction of PHZ size to 0.45 cm(IQR 0.0-1.36 cm; p < 0.001). There was no association between postoperative hematoma volume and size of the PHZ. Our findings illustrate that the extent of the PHZ cannot be generally assumed to be constant in size and that this differs significantly following hematoma reduction in patients with space occupying lobar SICH. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Beseoglu, Kerim; Etminan, Nima; Steiger, Hans-Jakob; Haenggi, Daniel [Heinrich-Heine-Universitaet Duesseldorf, Department of Neurosurgery, Medical Faculty, Duesseldorf (Germany); Turowski, Bernd [Heinrich-Heine-Universitaet Duesseldorf, Department of Diagnostic and Interventional Radiology, Medical Faculty, Duesseldorf (Germany)
2014-07-15
Existing data on perfusion imaging assumes the perihemorrhagic zone (PHZ) in patients with intracerebral hemorrhage (ICH) to be size steady. This study investigates the size of the perihemorrhagic zone (PHZ) in patients with lobar ICH in relation to hematoma volume during the course of treatment using perfusion CT (PCT). The present analysis is based on a previously reported cohort of 20 patients undergoing surgical evacuation for lobar SICH, with pre- and early postoperative PCT scanning. Time to peak of the residue function (T{sub max}) was measured based on the 360 cortical banding method and singular value decomposition. The size of PHZ was determined before and after treatment and correlated with hematoma volume. Preoperative mean hematoma volume constituted 63.0 ml (interquartile ranges (IQR) 39.7-99.4 ml), which correlated significantly (r = 0.563, p = 0.010) with mean PHZ size (5.67 cm, IQR 5.44-8.17 cm). Following a surgical hematoma evacuation, mean hematoma volume was reduced to 2.5 ml IQR 0.0-9.5 ml, which also resulted in a significant reduction of PHZ size to 0.45 cm(IQR 0.0-1.36 cm; p < 0.001). There was no association between postoperative hematoma volume and size of the PHZ. Our findings illustrate that the extent of the PHZ cannot be generally assumed to be constant in size and that this differs significantly following hematoma reduction in patients with space occupying lobar SICH. (orig.)
A free-volume modification of GEM-QC to correlate VLE and LLE in polymer solutions
International Nuclear Information System (INIS)
Radfarnia, H.R.; Taghikhani, V.; Ghotbi, C.; Khoshkbarchi, M.K.
2004-01-01
The generalized quasi-chemical (GEM-QC) model proposed by Wang and Vera is modified to correlate better the phase equilibrium and to overcome the shortcoming of the original model to predict the lower critical solution temperature (LCST) of binary polymer solutions. This shortcoming is mainly because the GEM-QC model does not consider the effect of free-volume, which is important in systems containing molecules with large size differences. The proposed modification is based on replacing the combinatorial term of the GEM-QC model by a term proposed by Kontogerogis et al., which includes the effect of the free-volume. The main advantage of the free volume generalized quasi-chemical (GEM-QC-FV) model over the original GEM-QC is its ability to predict the phase behaviour of binary polymer solutions with LCST behaviour. In addition, the free volume UNIQUAC (UNIQUAC-FV) model is used to correlate VLE and LLE experimental data for binary polymer solutions. The comparison of the results obtained from the GEM-QC-FV model and the UNIQUAC-FV model shows the superiority of the GEM-QC-FV model in correlating the VLE and LLE experimental data for binary polymer solutions
International Nuclear Information System (INIS)
Zhang Yingjie; Li Jianbin; Tian Shiyu; Li Fengxiang; Fan Tingyong; Shao Qian; Xu Min; Lu Jie
2011-01-01
Objective: To investigate the correlation of position movement of primary tumor with interested organs and skin markers, and to investigate the correlation of volume variation of primary tumors and lungs during different respiration phases for patients with lung cancer at free breath condition scanned by four-dimensional CT (4DCT) simulation. Methods: 16 patients with lung cancer were scanned at free breath condition by simulation 4DCT which connected to a respiration-monitoring system. A coordinate system was created based on image of T 5 phase,gross tumor volume (GTV) and normal tissue structures of 10 phases were contoured. The three dimensional position variation of them were measured and their correlation were analyzed, and the same for the volume variation of GTV and lungs of 10 respiratory phases. Results: Movement range of lung cancer in different lobe differed extinct: 0.8 - 5.0 mm in upper lobe, 5.7 -5.9 mm in middle lobe and 10.2 - 13.7 mm in lower lobe, respectively. Movement range of lung cancer in three dimensional direction was different: z-axis 4.3 mm ± 4.3 mm > y-axis 2.2 mm ± 1.0 mm > x-axis 1.7 mm ± 1.5 mm (χ 2 =16.22, P =0.000), respectively. There was no statistical significant correlation for movement vector of GTV and interested structures (r =-0.50 - -0.01, P =0.058 - -0.961), nor for volume variation of tumor and lung (r =0.23, P =0.520). Conclusions: Based on 4DCT, statistically significant differences of GTV centroid movement are observed at different pulmonary lobes and in three dimensional directions. So individual 4DCT measurement is necessary for definition of internal target volume margin for lung cancer. (authors)
Kjærgaard, Jane; Sillesen, Martin; Beier-Holgersen, Randi
2016-01-01
Since 2003, United States residents have been limited to an 80-hour workweek. This has prompted concerns of reduced educational quality, especially inadequate operating exposure. In contrast, the Danish surgical specialty-training program mandates a cap on working hours of 37 per week. We hypothesize that there is no direct correlation between work-hours and operative volume achieved during surgical residency. To test the hypothesis, we compare Danish and US operative volumes achieved during surgical residency training. Retrospective comparative study. The data from the US population was extracted from the Accreditation Council for Graduate Medical Education database for General Surgery residents from 2012 to 2013. For Danish residents, a questionnaire with case categories matching the Accreditation Council for Graduate Medical Education categories were sent to all Danish surgeons graduating the national surgical residency program in 2012 or 2013, 54 in total. In all, 30 graduated residents (55%) responded to the Danish survey. We found no significant differences in mean total major procedures (1002.4 vs 976.9, p = 0.28) performed during residency training, but comparing average major procedures per year, the US residents achieve significantly more (132.3 vs 195.4, p work-hours and operative volumes achievable. Factors other than work-hours seem to effect on operative volumes achieved during training. Copyright © 2016 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.
Jong, Rudiyanto P.; Osman, Kahar; Adib, M. Azrul Hisham M.
2012-06-01
Mitral valve prolapse without proper monitoring might lead to a severe mitral valve failure which eventually leads to a sudden death. Additional information on the mitral valve leaflet condition against the backflow volume would be an added advantage to the medical practitioner for their decision on the patients' treatment. A study on two dimensional echocardiography images has been conducted and the correlations between the backflow volume of the mitral regurgitation and mitral valve leaflet Young modulus have been obtained. Echocardiogram images were analyzed on the aspect of backflow volume percentage and mitral valve leaflet dimensions on different rates of backflow volume. Young modulus values for the mitral valve leaflet were obtained by using the principle of elastic deflection and deformation on the mitral valve leaflet. The results show that the backflow volume increased with the decrease of the mitral valve leaflet Young modulus which also indicate the condition of the mitral valve leaflet approaching failure at high backflow volumes. Mitral valve leaflet Young modulus values obtained in this study agreed with the healthy mitral valve leaflet Young modulus from the literature. This is an initial overview of the trend on the prediction of the behaviour between the fluid and the structure of the blood and the mitral valve which is extendable to a larger system of prediction on the mitral valve leaflet condition based on the available echocardiogram images.
Directory of Open Access Journals (Sweden)
Fan Wenyuan
2017-01-01
Full Text Available A laser image system has been established to quantify the characteristics of growing bubbles in quiescent shear-thinning fluids. Bubble formation mechanism was investigated by comparing the evolutions of bubble instantaneous shape, volume and surface area in two shear-thinning liquids with those in Newtonian liquid. The effects of solution mass concentration, gas chamber volume and orifice diameter on bubble detachment volume are discussed. By dimensional analysis, a single bubble volume detached within a moderate gas flowrate range was developed as a function of Reynolds number ,Re, Weber number, We, and gas chamber number, Vc, based on the orifice diameter. The results reveal that the generated bubble presents a slim shape due to the shear-thinning effect of the fluid. Bubble detachment volume increases with the solution mass concentration, gas chamber volume and orifice diameter. The results predicted by the present correlation agree better with the experimental data than the previous ones within the range of this paper.
Asymptotic analysis of fundamental solutions of Dirac operators on even dimensional Euclidean spaces
International Nuclear Information System (INIS)
Arai, A.
1985-01-01
We analyze the short distance asymptotic behavior of some quantities formed out of fundamental solutions of Dirac operators on even dimensional Euclidean spaces with finite dimensional matrix-valued potentials. (orig.)
Variational estimates for the mass gap of SU(2) Euclidean lattice gauge theory
International Nuclear Information System (INIS)
Hari Dass, N.D.
1984-10-01
The purpose of this letter is to report on the progress made in our understanding of series expansions for the masses in lattice gauge theories by the application of variational techniques to the Euclidean SU(2) lattice gauge theory. (Auth.)
Efficient gamma index calculation using fast Euclidean distance transform
Energy Technology Data Exchange (ETDEWEB)
Chen Mingli; Lu Weiguo; Chen Quan; Ruchala, Kenneth; Olivera, Gustavo [TomoTherapy Inc., 1240 Deming Way, Madison, WI 53717 (United States)], E-mail: wlu@tomotherapy.com
2009-04-07
The gamma index is a tool for dose distribution comparison. It combines both dose difference (DD) and distance to agreement (DTA) into a single quantity. Though it is an effective measure, making up for the inadequacy of DD or DTA alone, its calculation can be very time-consuming. For a k-D space with N quantization levels in each dimension, the complexity of the exhaustive search is O(N{sup 2k}). In this work, we proposed an efficient method that reduces the complexity from O(N{sup 2k}) to O(N{sup k}M), where M is the number of discretized dose values and is comparable to N. More precisely, by embedding the reference dose distribution in a (k+1)-D spatial-dose space, we can use fast Euclidean distance transform with linear complexity to obtain a table of gamma indices evaluated over a range of the (k+1)-D spatial-dose space. Then, to obtain gamma indices for the test dose distribution, it requires only table lookup with complexity O(N{sup k}). Such a table can also be used for other test dose distributions as long as the reference dose distribution is the same. Simulations demonstrated the efficiency of our proposed method. The speedup for 3D gamma index calculation is expected to be on the order of tens of thousands (from O(N{sup 6}) to O(N{sup 3}M)) if N is a few hundreds, which makes clinical usage of the 3D gamma index feasible. A byproduct of the gamma index table is that the gradient of the gamma index with respect to either the spatial or dose dimension can be easily derived. The gradient can be used to identify the main causes of the discrepancy from the reference distribution at any dose point in the test distribution or incorporated in treatment planning and machine parameter optimization.
Euclidean action for vacuum decay in a de Sitter universe
International Nuclear Information System (INIS)
Balek, V.; Demetrian, M.
2005-01-01
The behavior of the action of the instantons describing vacuum decay in a de Sitter is investigated. For a near-to-limit instanton (a Coleman-de Luccia instanton close to some Hawking-Moss instanton) we find approximate formulas for the Euclidean action by expanding the scalar field and the metric of the instanton in the powers of the scalar field amplitude. The order of the magnitude of the correction to the Hawking-Moss action depends on the order of the instanton (the number of crossings of the barrier by the scalar field): for instantons of odd and even orders the correction is of the fourth and third order in the scalar field amplitude, respectively. If a near-to-limit instanton of the first order exists in a potential with the curvature at the top of the barrier greater than 4x(Hubble constant) 2 , which is the case if the fourth derivative of the potential at the top of the barrier is greater than some negative limit value, the action of the instanton is less than the Hawking-Moss action and, consequently, the instanton determines the outcome of the vacuum decay if no other Coleman-de Luccia instanton is admitted by the potential. A numerical study shows that for the quartic potential the physical mode of the vacuum decay is given by the Coleman-de Luccia instanton of the first order also in the region of parameters in which the potential admits two instantons of the second order
Manton, Jonathan H.
2012-01-01
The Newton iteration is a popular method for minimising a cost function on Euclidean space. Various generalisations to cost functions defined on manifolds appear in the literature. In each case, the convergence rate of the generalised Newton iteration needed establishing from first principles. The present paper presents a framework for generalising iterative methods from Euclidean space to manifolds that ensures local convergence rates are preserved. It applies to any (memoryless) iterative m...
Classical and quantum integrability of 2D dilaton gravities in Euclidean space
International Nuclear Information System (INIS)
Bergamin, L; Grumiller, D; Kummer, W; Vassilevich, D V
2005-01-01
Euclidean dilaton gravity in two dimensions is studied exploiting its representation as a complexified first order gravity model. All local classical solutions are obtained. A global discussion reveals that for a given model only a restricted class of topologies is consistent with the metric and the dilaton. A particular case of string motivated Liouville gravity is studied in detail. Path integral quantization in generic Euclidean dilaton gravity is performed non-perturbatively by analogy to the Minkowskian case
Euclidean Geometry Codes, minimum weight words and decodable error-patterns using bit-flipping
DEFF Research Database (Denmark)
Høholdt, Tom; Justesen, Jørn; Jonsson, Bergtor
2005-01-01
We determine the number of minimum wigth words in a class of Euclidean Geometry codes and link the performance of the bit-flipping decoding algorithm to the geometry of the error patterns.......We determine the number of minimum wigth words in a class of Euclidean Geometry codes and link the performance of the bit-flipping decoding algorithm to the geometry of the error patterns....
Linearization of Euclidean Norm Dependent Inequalities Applied to Multibeam Satellites Design
Camino , Jean-Thomas; Artigues , Christian; Houssin , Laurent; Mourgues , Stéphane
2016-01-01
Euclidean norm computations over continuous variables appear naturally in the constraints or in the objective of many problems in the optimization literature, possibly defining non-convex feasible regions or cost functions. When some other variables have discrete domains, it positions the problem in the challenging Mixed Integer Nonlinear Programming (MINLP) class. For any MINLP where the nonlinearity is only present in the form of inequality constraints involving the Euclidean norm, we propo...
General Rotational Surfaces in Pseudo-Euclidean 4-Space with Neutral Metric
Aleksieva, Yana; Milousheva, Velichka; Turgay, Nurettin Cenk
2016-01-01
We define general rotational surfaces of elliptic and hyperbolic type in the pseudo-Euclidean 4-space with neutral metric which are analogous to the general rotational surfaces of C. Moore in the Euclidean 4-space. We study Lorentz general rotational surfaces with plane meridian curves and give the complete classification of minimal general rotational surfaces of elliptic and hyperbolic type, general rotational surfaces with parallel normalized mean curvature vector field, flat general rotati...
International Nuclear Information System (INIS)
Ding Bei; Ling Huawei; Zhang Huan; Song Qi; Dong Haipeng; Chen Kemin
2007-01-01
Objective: To evaluate the correlation between cerebral blood volume and permeability surface by using multislice CT perfusion imaging with glioma grade. Methods: Ninteen patients with gliomas underwent conventional MR and multislice CT perfusion imaging preoperatively. These patients were divided into low grade and high grade groups which were correspond to WHO II grade gliomas and WHO III or IV grade gliomas respectively. CT data were transferred to on-line working station and processed to obtain time-signal curves, color perfusion maps and calculated perfusion parameters, including cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTF) and permeability surfaces (PS) in tumoral parenchyma. Kruskal-Wallis test and correlation of CBV and PS was assessed by using SPSS 11.0 software. Results: The median of CBV and PS in low-grade and high-grade glioma were 2.7, 6.5 ml/100 g; 0.389, 12.810 ml·100 g -1 ·min -1 respectively, corresponding t value were 12.907 13.500 with P<0.05. Pearson correlations between CBV and PS were as follows: in low-grade group, r=-0.058, in high-grade group, r=0.648. Conclusion: Both CBV and PS have obvious correlation with glioma grade. The correlation between CBV and PS in low-grade glioma was weaker, probably because of the focal high vascularity in oligodendroglioma. (authors)
Wilhelm, Konrad; Miernik, Arkadiusz; Hein, Simon; Schlager, Daniel; Adams, Fabian; Benndorf, Matthias; Fritz, Benjamin; Langer, Mathias; Hesse, Albrecht; Schoenthaler, Martin; Neubauer, Jakob
2018-06-02
To validate AutoMated UroLithiasis Evaluation Tool (AMULET) software for kidney stone volumetry and compare its performance to standard clinical practice. Maximum diameter and volume of 96 urinary stones were measured as reference standard by three independent urologists. The same stones were positioned in an anthropomorphic phantom and CT scans acquired in standard settings. Three independent radiologists blinded to the reference values took manual measurements of the maximum diameter and automatic measurements of maximum diameter and volume. An "expected volume" was calculated based on manual diameter measurements using the formula: V=4/3 πr³. 96 stones were analyzed in the study. We had initially aimed to assess 100. Nine were replaced during data acquisition due of crumbling and 4 had to be excluded because the automated measurement did not work. Mean reference maximum diameter was 13.3 mm (5.2-32.1 mm). Correlation coefficients among all measured outcomes were compared. The correlation between the manual and automatic diameter measurements to the reference was 0.98 and 0.91, respectively (pvolumetry is possible and significantly more accurate than diameter-based volumetric calculations. To avoid bias in clinical trials, size should be measured as volume. However, automated diameter measurements are not as accurate as manual measurements.
Malik, Muhammad Danie Al; Kholilah, Nenik; Kurniasih, Eka Maya; Sembiring, Andrianus; Pertiwi, Ni Putu Dian; Ambariyanto, Ambariyanto; Munasik, Munasik; Meyer, Christopher
2018-02-01
Decapod is known as cryptofauna which is also important component of coral reef biodiversity. Dead corals are one of the area which usually used by decapods to live. This research aims to observe the diversity of cryptofauna (decapods) and the correlation between the number of decapods with the volume of dead corals. Ten dead corals, Pocillopora sp., were collected at 5 m depth at Bunaken Island. These dead corals were measured their volume and all decapods found were counted and identified up to family level. The richness and abundance were analyzed using ACE (Abundance-Based Coverage Estimates) and Chao 1. The results show that there were in total 474 decapods from 13 families found within all ten dead corals. Xanthidae was showed as the most abundance family among all, with 161 individual. Diversity index of decapods was found at medium category with value of 2.01. Rarefaction curve based on richness and abundance showed an estimation of 13 families. The result also indicated that the asymptote stage was reached on the 10th dead coral samples. The correlation between decapod with the volume of dead coral were showed significant positive correlation (r = 0.673, p<0.05). This result provides benefits to basic knowledge about diversity of decapod which one of cryptofauna as component fauna have a habitat on coral reef ecosystem.
Hippocampal subfield volumes: Age, vascular risk, and correlation with associative memory
Directory of Open Access Journals (Sweden)
Yee Lee eShing
2011-02-01
Full Text Available Aging and age-related diseases have negative impact on the hippocampus (HC, which is crucial for such age-sensitive functions as memory formation, maintenance, and retrieval. We examined age differences in hippocampal subfield volumes in 10 younger and 19 older adults, and association of those volumes with memory performance in the older participants. We manually measured volumes of HC regions CA1 and CA2 (CA1-2, sectors CA3 and CA4 plus dentate gyrus (CA3-4/DG, subiculum and the entorhinal cortex using a contrast-optimized high-resolution PD-weighted MRI sequence. Although, as in previous reports, the volume of one region (CA1-2 was larger in the young, the difference was due to the presence of hypertensive subjects among the older adults. Among older participants, increased false alarm (FA rate in an associative recognition memory task was linked to reduced CA3-4/DG volume. We discuss the role of the dentate gyrus in pattern separation and the formation of discrete memory representations.
Energy Technology Data Exchange (ETDEWEB)
Gahlyan, Suman; Rani, Manju; Maken, Sanjeev Kumar [Deenbandhu Chhotu Ram University of Science and Technology, Murthal (India); Lee, Inkyu; Moon, Il [Yonsei University, Seoul (Korea, Republic of)
2015-01-15
Excess molar volumes (V{sub m}{sup E} ) have been measured at 303.15 K for 1-propanol+benzene or toluene or o- or m- or p-xylene mixtures using V-shape dilatometer. The V{sub m}{sup E} values, for an equimolar composition, vary in the order: benzene>toluene-m-xylene>o-xylene>p-xylene. The V{sub m}{sup E} data have been used to calculate partial molar volumes, excess partial molar volumes, and apparent molar volumes of 1-propanol and aromatic hydrocarbons over the entire range of composition. The excess volume data have also been interpreted in terms of graph-theoretical approach and Prigogine-Flory-Patterson theory (PFP). While PFP theory fails to predict the V{sub m}{sup E} values for systems with s-shaped V{sub m}{sup E} versus x{sub 1} graph, the V{sub m}{sup E} values calculated by graph theory compare reasonably well with the corresponding experimental values. This graph theory analysis has further yielded information about the state of aggregation of pure components as well as of the mixtures.
International Nuclear Information System (INIS)
Gahlyan, Suman; Rani, Manju; Maken, Sanjeev Kumar; Lee, Inkyu; Moon, Il
2015-01-01
Excess molar volumes (V m E ) have been measured at 303.15 K for 1-propanol+benzene or toluene or o- or m- or p-xylene mixtures using V-shape dilatometer. The V m E values, for an equimolar composition, vary in the order: benzene>toluene-m-xylene>o-xylene>p-xylene. The V m E data have been used to calculate partial molar volumes, excess partial molar volumes, and apparent molar volumes of 1-propanol and aromatic hydrocarbons over the entire range of composition. The excess volume data have also been interpreted in terms of graph-theoretical approach and Prigogine-Flory-Patterson theory (PFP). While PFP theory fails to predict the V m E values for systems with s-shaped V m E versus x 1 graph, the V m E values calculated by graph theory compare reasonably well with the corresponding experimental values. This graph theory analysis has further yielded information about the state of aggregation of pure components as well as of the mixtures
Dose-volume correlation in radiation-related late small-bowel complication
International Nuclear Information System (INIS)
Letschert, J.G.J.; Lebesque, J.V.; Boer, R.W. de; hart, A.A.M.; Barteling, H.
1990-01-01
The effects of the volume of irradiated small bowel on late small-bowel tolerance was studied, taking into account the equivalent total dose ant type of pre-irradiation surgical procedure. A method was developed to estimate small-bowel volumes in the high-bowel volumes were measured for three-field and AP-PA pelvic treatments (165 cm 3 and 400 cm 3 , respectively), extended AP-PA treatment of para-aortic and iliac nodes (1000 cm 3 ). In a retrospective study of 111 patientst irradiated after surgery for rectal or recto-sigmoid cancer to a dose of 45-50 Gy in 5 weeks, extended AP-PA pelvic treatment (n = 27) resulted in a high incidence of severe small-bowel complications (37%), whereas for limited (three-field) pelvic treatment (n = 84) the complication rate was 6%. These complication data together with data from the literature on postoperative radiation-related small-bowel complications were analysed using the maximum likelihood method to fit the data to the logistic form of the dose-response relation, taking the volume effect into account by a power law. The analysis indicated that the incidence of radiation-related small-bowel compllications was higher after rectal surgery than after other types of surgery, which might be explained by the development of more adhesions. For both types of surgery a volume exponent of the power-law of 0.26 ± 0.05 was established. This means that if the small-bowel volume is increased by a factor of 2, the total dose has to be reduced by 17% for the same incidence of small-bowel complications. (author). 45 refs.; 6 figs.; 4 tabs
Energy Technology Data Exchange (ETDEWEB)
Nanda, Ronica H., E-mail: rhazari@emory.edu [Department of Radiation Oncology, Winship Cancer Institute, Emory University College of Medicine, Atlanta, Georgia (United States); Ganju, Rohit G.; Schreibmann, Edward [Department of Radiation Oncology, Winship Cancer Institute, Emory University College of Medicine, Atlanta, Georgia (United States); Chen, Zhengjia; Zhang, Chao [Department of Biostatistics and Bioinformatics Shared Resource, Winship Cancer Institute, Emory University Rollins School of Public Health, Atlanta, Georgia (United States); Jegadeesh, Naresh; Cassidy, Richard; Deng, Claudia; Eaton, Bree R.; Esiashvili, Natia [Department of Radiation Oncology, Winship Cancer Institute, Emory University College of Medicine, Atlanta, Georgia (United States)
2017-06-01
Purpose: Radiation-induced brainstem toxicity after treatment of pediatric posterior fossa malignancies is incompletely understood, especially in the era of intensity modulated radiation therapy (IMRT). The rates of, and predictive factors for, brainstem toxicity after photon RT for posterior fossa tumors were examined. Methods and Materials: After institutional review board approval, 60 pediatric patients treated at our institution for nonmetastatic infratentorial ependymoma and medulloblastoma with IMRT were included in the present analysis. Dosimetric variables, including the mean and maximum dose to the brainstem, the dose to 10% to 90% of the brainstem (in 10% increments), and the volume of the brainstem receiving 40, 45, 50, and 55 Gy were recorded for each patient. Acute (onset within 3 months) and late (>3 months of RT completion) RT-induced brainstem toxicities with clinical and radiographic correlates were scored using Common Terminology Criteria for Adverse Events, version 4.0. Results: Patients aged 1.4 to 21.8 years underwent IMRT or volumetric arc therapy postoperatively to the posterior fossa or tumor bed. At a median clinical follow-up period of 2.8 years, 14 patients had developed symptomatic brainstem toxicity (crude incidence 23.3%). No correlation was found between the dosimetric variables examined and brainstem toxicity. Vascular injury or ischemia showed a strong trend toward predicting brainstem toxicity (P=.054). Patients with grade 3 to 5 brainstem toxicity had undergone treatment to significant volumes of the posterior fossa. Conclusion: The results of the present series demonstrate a low, but not negligible, risk of brainstem radiation necrosis for pediatric patients with posterior fossa malignancies treated with IMRT. No specific dose-volume correlations were identified; however, modern treatment volumes might help limit the incidence of severe toxicity. Additional work investigating inherent biologic sensitivity might also provide
Machado, Marco; Willardson, Jeffrey M.; Silva, Dailson P.; Frigulha, Italo C.; Koch, Alexander J.; Souza, Sergio C.
2012-01-01
In the current study, we examined the relationship between serum creatine kinase (CK) activity following upper body resistance exercise with a 1- or 3-min rest between sets. Twenty men performed two sessions, each consisting of four sets with a 10-repetition maximum load. The results demonstrated significantly greater volume for the 3-min…
Keyes, S D; Gillard, F; Soper, N; Mavrogordato, M N; Sinclair, I; Roose, T
2016-06-14
The mechanical impedance of soils inhibits the growth of plant roots, often being the most significant physical limitation to root system development. Non-invasive imaging techniques have recently been used to investigate the development of root system architecture over time, but the relationship with soil deformation is usually neglected. Correlative mapping approaches parameterised using 2D and 3D image data have recently gained prominence for quantifying physical deformation in composite materials including fibre-reinforced polymers and trabecular bone. Digital Image Correlation (DIC) and Digital Volume Correlation (DVC) are computational techniques which use the inherent material texture of surfaces and volumes, captured using imaging techniques, to map full-field deformation components in samples during physical loading. Here we develop an experimental assay and methodology for four-dimensional, in vivo X-ray Computed Tomography (XCT) and apply a Digital Volume Correlation (DVC) approach to the data to quantify deformation. The method is validated for a field-derived soil under conditions of uniaxial compression, and a calibration study is used to quantify thresholds of displacement and strain measurement. The validated and calibrated approach is then demonstrated for an in vivo test case in which an extending maize root in field-derived soil was imaged hourly using XCT over a growth period of 19h. This allowed full-field soil deformation data and 3D root tip dynamics to be quantified in parallel for the first time. This fusion of methods paves the way for comparative studies of contrasting soils and plant genotypes, improving our understanding of the fundamental mechanical processes which influence root system development. Copyright © 2016 Elsevier Ltd. All rights reserved.
Assessment of the Log-Euclidean Metric Performance in Diffusion Tensor Image Segmentation
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Mostafa Charmi
2010-06-01
Full Text Available Introduction: Appropriate definition of the distance measure between diffusion tensors has a deep impact on Diffusion Tensor Image (DTI segmentation results. The geodesic metric is the best distance measure since it yields high-quality segmentation results. However, the important problem with the geodesic metric is a high computational cost of the algorithms based on it. The main goal of this paper is to assess the possible substitution of the geodesic metric with the Log-Euclidean one to reduce the computational cost of a statistical surface evolution algorithm. Materials and Methods: We incorporated the Log-Euclidean metric in the statistical surface evolution algorithm framework. To achieve this goal, the statistics and gradients of diffusion tensor images were defined using the Log-Euclidean metric. Numerical implementation of the segmentation algorithm was performed in the MATLAB software using the finite difference techniques. Results: In the statistical surface evolution framework, the Log-Euclidean metric was able to discriminate the torus and helix patterns in synthesis datasets and rat spinal cords in biological phantom datasets from the background better than the Euclidean and J-divergence metrics. In addition, similar results were obtained with the geodesic metric. However, the main advantage of the Log-Euclidean metric over the geodesic metric was the dramatic reduction of computational cost of the segmentation algorithm, at least by 70 times. Discussion and Conclusion: The qualitative and quantitative results have shown that the Log-Euclidean metric is a good substitute for the geodesic metric when using a statistical surface evolution algorithm in DTIs segmentation.
Directory of Open Access Journals (Sweden)
Tatiana Lauxen Peruzzolo
2015-01-01
Full Text Available Pediatric bipolar disorder (PBD is a serious mental disorder that affects the development and emotional growth of affected patients. The brain derived neurotrophic factor (BDNF is recognized as one of the possible markers of the framework and its evolution. Abnormalities in BDNF signaling in the hippocampus could explain the cognitive decline seen in patients with TB. Our aim with this study was to evaluate possible changes in hippocampal volume in children and adolescents with BD and associate them to serum BDNF. Subjects included 30 patients aged seven to seventeen years from the ProCAB (Program for Children and Adolescents with Bipolar Disorder. We observed mean right and left hippocampal volumes of 41910.55 and 41747.96 mm3, respectively. No statistically significant correlations between peripheral BDNF levels and hippocampal volumes were found. We believe that the lack of correlation observed in this study is due to the short time of evolution of BD in children and adolescents. Besides studies with larger sample sizes to confirm the present findings and longitudinal assessments, addressing brain development versus a control group and including drug-naive patients in different mood states may help clarify the role of BDNF in the brain changes consequent upon BD.
Bioimpedance measurement of body water correlates with measured volume balance in injured patients.
Rosemurgy, A S; Rodriguez, E; Hart, M B; Kurto, H Z; Albrink, M H
1993-06-01
Bioimpedance technology is being used increasingly to determine drug volume of distribution, body water status, and nutrition repletion. Its accuracy in patients experiencing large volume flux is not established. To address this, we undertook this prospective study in 54 consecutive seriously injured adults who had emergency celiotomy soon after arrival in the emergency department. Bioimpedance measurements were obtained in the emergency department before the patient was transported to the operating room, on completion of celiotomy, and 24 hours and 48 hours after celiotomy. Bioimpedance measurements of body water were compared with measured fluid balance. If insensible losses are subtracted from measured fluid balance, the percentage of body weight, which is body water determined by bioimpedance, closely follows fluid flux. This study supports the use of bioimpedance measurements in determining total body water even during periods of surgery, blood loss, and vigorous resuscitation.
Abdul-Kareem, Ihssan A; Stancak, Andrej; Parkes, Laura M; Sluming, Vanessa
2011-01-01
To compare manual volumetry of gray matter (GM) / white matter (WM) of Broca's area subparts: pars opercularis (POP) and pars triangularis (PTR) in both hemispheres between musicians and nonmusician, as it has been shown that these regions are crucial for musical abilities. A previous voxel-based morphometric (VBM) study conducted in our laboratory reported increased GM density in Broca's area of left hemisphere in male orchestral musicians. Functional segregation of POP/PTR justified separate volumetric analysis of these parts. We used the same cohort for the VBM study. Manual morphometry (stereology) was used to compare volumes between 26/26 right-handed orchestral musicians/nonmusicians. As expected, musicians showed significantly increased GM volume in the Broca's area, specifically in the left POP. No significant results were detected in right POP, left/right PTR GM volumes, and WM volumes for all regions. Results were positively correlated with years of musical performance (r = 0.7, P = 0.0001). This result corroborates the VBM study and is in line with the hypothesis of critical involvement of POP in hearing-action integration being an integral component of frontoparietotemporal mirror neuron network. We hypothesize that increased size of musicians' left POP represent use-dependent structural adaptation in response to intensive audiomotor skill acquisition. Copyright © 2010 Wiley-Liss, Inc.
Ducharme, Simon; Hudziak, James J; Botteron, Kelly N; Ganjavi, Hooman; Lepage, Claude; Collins, D Louis; Albaugh, Matthew D; Evans, Alan C; Karama, Sherif
2011-08-01
The anterior cingulate cortex (ACC), orbitofrontal cortex (OFC), and basal ganglia have been implicated in pathological aggression. This study aimed at identifying neuroanatomical correlates of impulsive aggression in healthy children. Data from 193 representative 6- to 18-year-old healthy children were obtained from the National Institutes of Health Magnetic Resonance Imaging Study of Normal Brain Development after a blinded quality control. Cortical thickness and subcortical volumes were obtained with automated software. Aggression levels were measured with the Aggressive Behavior scale (AGG) of the Child Behavior Checklist. AGG scores were regressed against cortical thickness and basal ganglia volumes using first- and second-order linear models while controlling for age, gender, scanner site, and total brain volume. Gender by AGG interactions were analyzed. There were positive associations between bilateral striatal volumes and AGG scores (right: r = .238, p = .001; left: r = .188, p = .01). A significant association was found with right ACC and subgenual ACC cortical thickness in a second-order linear model (p right ACC cortex. An AGG by gender interaction trend was found in bilateral OFC and ACC associations with AGG scores. This study shows the existence of relationships between impulsive aggression in healthy children and the structure of the striatum and right ACC. It also suggests the existence of gender-specific patterns of association in OFC/ACC gray matter. These results may guide research on oppositional-defiant and conduct disorders. Copyright © 2011 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.
SU-E-T-72: A Retrospective Correlation Analysis On Dose-Volume Control Points and Treatment Outcomes
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Roy, A; Nohadani, O [Northwestern University, Evanston, IL (United States); Refaat, T; Bacchus, I; Cutright, D; Sathiaseelan, V; Mittal, B [Northwestern University, Chicago, IL (United States)
2015-06-15
Purpose: To quantify correlation between dose-volume control points and treatment outcomes. Specifically, two outcomes are analyzed: occurrence of radiation induced dysphagia and target complications. The results inform the treatment planning process when competing dose-volume criteria requires relaxations. Methods: 32 patients, treated with whole-field sequential intensity modulated radiation therapy during 2009–2010 period, are considered for this study. Acute dysphagia that is categorized into 3 grades is observed on all patients. 3 patients are observed in grade 1, 17 patients in grade 2, and 12 patients in grade 3. Ordinal logistic regression is employed to establish correlations between grades of dysphagia and dose to cervico-thoracic esophagus. Particularly, minimum (Dmin), mean (Dmean), and maximum (Dmax) dose control points are analyzed. Additionally, target complication, which includes local-regional recurrence and/or distant metastasis, is observed on 4 patients. Binary logistic regression is used to quantify correlation between target complication and four dose control points. Namely, ICRU recommended dose control points, D2, D50, D95, and D98 are analyzed. Results: For correlation with dysphagia, Dmin on cervico-thoracic esophagus is statistically significant (p-value = 0.005). Additionally, Dmean on cervico-thoracic esophagus is also significant in association with dysphagia (p-value = 0.012). However, no correlation was observed between Dmax and dysphagia (p-value = 0.263). For target complications, D50 on the target is a statistically significant dose control point (p-value = 0.032). No correlations were observed between treatment complications and D2 (p-value = 0.866), D95 (p-value = 0.750), and D98 (p-value = 0.710) on the target. Conclusion: Significant correlations are observed between radiation induced dysphagia and Dmean (and Dmin) to cervico-thoracic esophagus. Additionally, correlation between target complications and median dose to target
SU-E-T-72: A Retrospective Correlation Analysis On Dose-Volume Control Points and Treatment Outcomes
International Nuclear Information System (INIS)
Roy, A; Nohadani, O; Refaat, T; Bacchus, I; Cutright, D; Sathiaseelan, V; Mittal, B
2015-01-01
Purpose: To quantify correlation between dose-volume control points and treatment outcomes. Specifically, two outcomes are analyzed: occurrence of radiation induced dysphagia and target complications. The results inform the treatment planning process when competing dose-volume criteria requires relaxations. Methods: 32 patients, treated with whole-field sequential intensity modulated radiation therapy during 2009–2010 period, are considered for this study. Acute dysphagia that is categorized into 3 grades is observed on all patients. 3 patients are observed in grade 1, 17 patients in grade 2, and 12 patients in grade 3. Ordinal logistic regression is employed to establish correlations between grades of dysphagia and dose to cervico-thoracic esophagus. Particularly, minimum (Dmin), mean (Dmean), and maximum (Dmax) dose control points are analyzed. Additionally, target complication, which includes local-regional recurrence and/or distant metastasis, is observed on 4 patients. Binary logistic regression is used to quantify correlation between target complication and four dose control points. Namely, ICRU recommended dose control points, D2, D50, D95, and D98 are analyzed. Results: For correlation with dysphagia, Dmin on cervico-thoracic esophagus is statistically significant (p-value = 0.005). Additionally, Dmean on cervico-thoracic esophagus is also significant in association with dysphagia (p-value = 0.012). However, no correlation was observed between Dmax and dysphagia (p-value = 0.263). For target complications, D50 on the target is a statistically significant dose control point (p-value = 0.032). No correlations were observed between treatment complications and D2 (p-value = 0.866), D95 (p-value = 0.750), and D98 (p-value = 0.710) on the target. Conclusion: Significant correlations are observed between radiation induced dysphagia and Dmean (and Dmin) to cervico-thoracic esophagus. Additionally, correlation between target complications and median dose to target
Variations of radon volume activities in soil and indoor air and their correlation
International Nuclear Information System (INIS)
Mojzes, A.
1998-01-01
Some manual measurements of volume activity of 222 Rn ai soil air and in indoor air of building together with parallel measurements of some meteorological parameters (temperature, humidity and pressure) of both atmospheric and indoor air were carried out. The measurements were performed in the building of Faculty and in its subsoil which consists of slope loams of the base of SW slopes of granitic Male Karpaty Mountains in the area of confluence of the Vidrica Creek with an arm of the Donau river. The monitoring measurements lasted form more than one and a half year, from January 1977 to August 1998, with the frequency of approximately once a week in each object. The soil air was taken from a permanently set up and sealed pipe from the depth of 0.8 m which was placed approximately 10 m from the building at the open air. All measurements of 222 Rn volume activities were performed with a portable fully automatic scintillation detector based on exchangeable Lucas cells. There were also performed the parallel measurements of some meteorological parameters (temperature, humidity and pressure) of air in each object. The geological basement of building is a source of indoor radon. The volume activities of soil 222 Rn range from about 2 kBq/m 3 to about 20 kBq/m 3 with the average of 9.26 kBq/m 3 and the standard deviation of 2.95 kBq/m 3 . The volume activities of indoor air in basement room were form 150 Bq/m 3 to 225 Bq/m 3 and on the third story they were from 125 Bq/m 3 to 175 Bq/m 3 (approximately). The results of monitoring measurements during 20 months period point out the intensity of interaction of geological substrate with building interior through the values of the volume activity of 222 Rn. Therefore a method of building foundation is one of the most important factors which determines the quantity of radon in indoor air. In the light of quality, the fluctuation of radon presence in the bottom part of the buildings is strongly determined by the variations of
DEFF Research Database (Denmark)
Sidaros, Annette; Skimminge, Arnold Jesper Møller; Liptrot, Matthew George
2009-01-01
with percent brain volume change (%BVC) ranging between − 0.6% and − 9.4% (mean − 4.0%). %BVC correlated significantly with injury severity, functional status at both scans, and with 1-year outcome. Moreover, %BVC improved prediction of long-term functional status over and above what could be predicted using......Traumatic brain injury (TBI) results in neurodegenerative changes that progress for months, perhaps even years post-injury. However, there is little information on the spatial distribution and the clinical significance of this late atrophy. In 24 patients who had sustained severe TBI we acquired 3D...... scan time point using SIENAX. Regional distribution of atrophy was evaluated using tensor-based morphometry (TBM). At the first scan time point, brain parenchymal volume was reduced by mean 8.4% in patients as compared to controls. During the scan interval, patients exhibited continued atrophy...
International Nuclear Information System (INIS)
Chang, Joe H.; Joon, Daryl Lim; Lee, Sze Ting; Gong, Sylvia J.; Scott, Andrew M.; Davis, Ian D.; Clouston, David; Bolton, Damien; Hamilton, Christopher S.; Khoo, Vincent
2011-01-01
Background and purpose: To evaluate the accuracy of 11 C-choline PET scans in defining dominant intraprostatic lesions (DILs) for radiotherapy target volume definition. Material and methods: Eight men with prostate cancer who had 11 C-choline PET scans prior to radical prostatectomy were studied. Several methods were used to contour the DIL on the PET scans: visual, PET Edge, Region Grow, absolute standardised uptake value (SUV) thresholds and percentage of maximum SUV thresholds. Prostatectomy specimens were sliced in the transverse plane and DILs were delineated on these by a pathologist. These were then compared with the PET scans. The accuracy of correlation was assessed by the Dice similarity coefficient (DSC) and the Youden index. Results: The contouring method resulting in both the highest DSC and the highest Youden index was 60% of the maximum SUV (SUV 60% ), with values of 0.64 and 0.51, respectively. However SUV 60% was not statistically significantly better than all of the other methods by either measure. Conclusions: Although not statistically significant, SUV 60% resulted in the best correlation between 11 C-choline PET and pathology amongst all the methods studied. The degree of correlation shown here is consistent with previous studies that have justified using imaging for DIL radiotherapy target volume definition.
Directory of Open Access Journals (Sweden)
Hajime Matsui
2017-12-01
Full Text Available In this study, we consider codes over Euclidean domains modulo their ideals. In the first half of the study, we deal with arbitrary Euclidean domains. We show that the product of generator matrices of codes over the rings mod a and mod b produces generator matrices of all codes over the ring mod a b , i.e., this correspondence is onto. Moreover, we show that if a and b are coprime, then this correspondence is one-to-one, i.e., there exist unique codes over the rings mod a and mod b that produce any given code over the ring mod a b through the product of their generator matrices. In the second half of the study, we focus on the typical Euclidean domains such as the rational integer ring, one-variable polynomial rings, rings of Gaussian and Eisenstein integers, p-adic integer rings and rings of one-variable formal power series. We define the reduced generator matrices of codes over Euclidean domains modulo their ideals and show their uniqueness. Finally, we apply our theory of reduced generator matrices to the Hecke rings of matrices over these Euclidean domains.
Epileptic Seizure Detection with Log-Euclidean Gaussian Kernel-Based Sparse Representation.
Yuan, Shasha; Zhou, Weidong; Wu, Qi; Zhang, Yanli
2016-05-01
Epileptic seizure detection plays an important role in the diagnosis of epilepsy and reducing the massive workload of reviewing electroencephalography (EEG) recordings. In this work, a novel algorithm is developed to detect seizures employing log-Euclidean Gaussian kernel-based sparse representation (SR) in long-term EEG recordings. Unlike the traditional SR for vector data in Euclidean space, the log-Euclidean Gaussian kernel-based SR framework is proposed for seizure detection in the space of the symmetric positive definite (SPD) matrices, which form a Riemannian manifold. Since the Riemannian manifold is nonlinear, the log-Euclidean Gaussian kernel function is applied to embed it into a reproducing kernel Hilbert space (RKHS) for performing SR. The EEG signals of all channels are divided into epochs and the SPD matrices representing EEG epochs are generated by covariance descriptors. Then, the testing samples are sparsely coded over the dictionary composed by training samples utilizing log-Euclidean Gaussian kernel-based SR. The classification of testing samples is achieved by computing the minimal reconstructed residuals. The proposed method is evaluated on the Freiburg EEG dataset of 21 patients and shows its notable performance on both epoch-based and event-based assessments. Moreover, this method handles multiple channels of EEG recordings synchronously which is more speedy and efficient than traditional seizure detection methods.
DEFF Research Database (Denmark)
Geirsson, Arnar; Ahlsson, Anders; Franco-Cereceda, Anders
2018-01-01
and C and cardiopulmonary bypass time, whereas later calendar year and higher hospital operative volumes predicted improved survival. CONCLUSIONS: Surgical mortality for acute Type A aortic dissection remains high but has decreased significantly over the last decade. This correlated with later year...... A Aortic Dissection is a retrospective database comprising 1159 patients (mean age 61.6 ± 12.2 years, 68% male) treated for acute Type A aortic dissection at 8 centres in Denmark, Finland, Iceland and Sweden from 2005 to 2014. Data gathered included demographics, symptoms, type of procedure, complications...
F. Thomas Ledig; J.L. Whitmore
1981-01-01
Caribbean pine is an important exotic being bred throughout the tropics, but published estimates are lacking for heritability of economically important traits and the genetic correlations between them. Based on a Puerto Rican trial of 16 open-pollinated parents of var. hondurensis selected in Belize, heritabilities for a number of characteristics...
Wall, Phillip D. H.; Carver, Robert L.; Fontenot, Jonas D.
2018-01-01
The overlap volume histogram (OVH) is an anatomical metric commonly used to quantify the geometric relationship between an organ at risk (OAR) and target volume when predicting expected dose-volumes in knowledge-based planning (KBP). This work investigated the influence of additional variables contributing to variations in the assumed linear DVH-OVH correlation for the bladder and rectum in VMAT plans of prostate patients, with the goal of increasing prediction accuracy and achievability of knowledge-based planning methods. VMAT plans were retrospectively generated for 124 prostate patients using multi-criteria optimization. DVHs quantified patient dosimetric data while OVHs quantified patient anatomical information. The DVH-OVH correlations were calculated for fractional bladder and rectum volumes of 30, 50, 65, and 80%. Correlations between potential influencing factors and dose were quantified using the Pearson product-moment correlation coefficient (R). Factors analyzed included the derivative of the OVH, prescribed dose, PTV volume, bladder volume, rectum volume, and in-field OAR volume. Out of the selected factors, only the in-field bladder volume (mean R = 0.86) showed a strong correlation with bladder doses. Similarly, only the in-field rectal volume (mean R = 0.76) showed a strong correlation with rectal doses. Therefore, an OVH formalism accounting for in-field OAR volumes was developed to determine the extent to which it improved the DVH-OVH correlation. Including the in-field factor improved the DVH-OVH correlation, with the mean R values over the fractional volumes studied improving from -0.79 to -0.85 and -0.82 to -0.86 for the bladder and rectum, respectively. A re-planning study was performed on 31 randomly selected database patients to verify the increased accuracy of KBP dose predictions by accounting for bladder and rectum volume within treatment fields. The in-field OVH led to significantly more precise
Posthuma, Daniëlle; Baaré, Wim F C; Hulshoff Pol, Hilleke E; Kahn, René S; Boomsma, Dorret I; De Geus, Eco J C
2003-04-01
We recently showed that the correlation of gray and white matter volume with full scale IQ and the Working Memory dimension are completely mediated by common genetic factors (Posthuma et al., 2002). Here we examine whether the other WAIS III dimensions (Verbal Comprehension, Perceptual Organization, Processing Speed) are also related to gray and white matter volume, and whether any of the dimensions are related to cerebellar volume. Two overlapping samples provided 135 subjects from 60 extended twin families for whom both MRI scans and WAIS III data were available. All three brain volumes are related to Working Memory capacity (r = 0.27). This phenotypic correlation is completely due to a common underlying genetic factor. Processing Speed was genetically related to white matter volume (r(g) = 0.39). Perceptual Organization was both genetically (r(g) = 0.39) and environmentally (r(e) = -0.71) related to cerebellar volume. Verbal Comprehension was not related to any of the three brain volumes. It is concluded that brain volumes are genetically related to intelligence which suggests that genes that influence brain volume may also be important for intelligence. It is also noted however, that the direction of causation (i.e., do genes influence brain volume which in turn influences intelligence, or alternatively, do genes influence intelligence which in turn influences brain volume), or the presence or absence of pleiotropy has not been resolved yet.
Ivannikov, Maxim V.; Sugimori, Mutsuyuki; Llinás, Rodolfo R.
2012-01-01
Synaptic plasticity in many regions of the central nervous system leads to the continuous adjustment of synaptic strength, which is essential for learning and memory. In this study, we show by visualizing synaptic vesicle release in mouse hippocampal synaptosomes that presynaptic mitochondria and specifically, their capacities for ATP production are essential determinants of synaptic vesicle exocytosis and its magnitude. Total internal reflection microscopy of FM1-43 loaded hippocampal synaptosomes showed that inhibition of mitochondrial oxidative phosphorylation reduces evoked synaptic release. This reduction was accompanied by a substantial drop in synaptosomal ATP levels. However, cytosolic calcium influx was not affected. Structural characterization of stimulated hippocampal synaptosomes revealed that higher total presynaptic mitochondrial volumes were consistently associated with higher levels of exocytosis. Thus, synaptic vesicle release is linked to the presynaptic ability to regenerate ATP, which itself is a utility of mitochondrial density and activity. PMID:22772899
Eissa, Iman M; Khalil, Noha M; El-Gendy, Heba A
2016-01-01
Purpose. To assess the tear film quantity and correlate it with the quality and stability of the tear film in diabetics and compare them to age matched controls. Introduction. Diabetes affects tear film parameters in multiple ways. Poor metabolic control and neuropathy are postulated factors. To further understand how diabetes affects tear film parameters this study was conducted. Subjects and Methods. Tear meniscus height was measured by anterior segment OCT, along with tear thinning time, a subtype of noninvasive tear break-up time, and blinking rate per minute which were all recorded for 22 diabetic patients. Correlations between these tear film parameters were studied and then compared to 16 age matched controls. Results. A statistically significant difference was found in blinking rate between the diabetic and the control group (P = 0.002), with higher blinking rate among diabetics. All tear film parameters were negatively correlated with duration of diabetes. A positive correlation was found between tear film volume and stability. Conclusion. Diabetes affects the tear film in various ways. Diabetics should be examined for dry eye signs even in absence of symptoms which may be masked by associated neuropathy. Duration of diabetes has an impact on tear film status.
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Iman M. Eissa
2016-01-01
Full Text Available Purpose. To assess the tear film quantity and correlate it with the quality and stability of the tear film in diabetics and compare them to age matched controls. Introduction. Diabetes affects tear film parameters in multiple ways. Poor metabolic control and neuropathy are postulated factors. To further understand how diabetes affects tear film parameters this study was conducted. Subjects and Methods. Tear meniscus height was measured by anterior segment OCT, along with tear thinning time, a subtype of noninvasive tear break-up time, and blinking rate per minute which were all recorded for 22 diabetic patients. Correlations between these tear film parameters were studied and then compared to 16 age matched controls. Results. A statistically significant difference was found in blinking rate between the diabetic and the control group (P=0.002, with higher blinking rate among diabetics. All tear film parameters were negatively correlated with duration of diabetes. A positive correlation was found between tear film volume and stability. Conclusion. Diabetes affects the tear film in various ways. Diabetics should be examined for dry eye signs even in absence of symptoms which may be masked by associated neuropathy. Duration of diabetes has an impact on tear film status.
Energy Technology Data Exchange (ETDEWEB)
Deantonio, L.; Masini, L. [University Hospital ' Maggiore della Carita' , Novara (Italy). Radiotherapy; Brambilla, M. [University Hospital ' Maggiore della Carita' , Novara (Italy). Medical Physics; Pia, F. [University Hospital ' Maggiore della Carita' , Novara (Italy). Otolaryngology; University of ' Piemonte Orientale' , Novara (Italy). Dept. of Medical Sciences; Krengli, M. [University Hospital ' Maggiore della Carita' , Novara (Italy). Radiotherapy; University of ' Piemonte Orientale' , Novara (Italy). Dept. of Translational Medicine and BRMA
2013-03-15
Background: Dysphagia is a complication of head and neck cancer patients undergoing radiotherapy (RT). We analysed frequency and severity of swallowing dysfunction and correlated these findings with dose-volume histograms (DVHs) of the pharyngeal constrictor muscles. Methods: A total of 50 patients treated by radical RT were enrolled. DVHs of constrictor muscles were correlated with acute and late dysphagia and with the items of three quality of life questionnaires. Results: Mean dose to superior and middle constrictor muscles (SCM, MCM), partial volume of SCM and MCM receiving a dose {>=} 50 Gy dose to the whole constrictor muscles {>=} 60 Gy and tumour location were associated to late dysphagia at univariate analysis. Mean dose to the MCM was the only statistically significant predictor of late dysphagia at the multivariable analysis. Conclusion: The study shows a significant relationship between long-term dysphagia and mean doses to SCM, MCM, whole constrictor muscles, and oropharyngeal tumour. This finding suggests a potential advantage in reducing the RT dose to swallowing structures to avoid severe dysphagia. (orig.)
International Nuclear Information System (INIS)
Deantonio, L.; Masini, L.; Brambilla, M.; Pia, F.; University of 'Piemonte Orientale', Novara; Krengli, M.; University of 'Piemonte Orientale', Novara
2013-01-01
Background: Dysphagia is a complication of head and neck cancer patients undergoing radiotherapy (RT). We analysed frequency and severity of swallowing dysfunction and correlated these findings with dose-volume histograms (DVHs) of the pharyngeal constrictor muscles. Methods: A total of 50 patients treated by radical RT were enrolled. DVHs of constrictor muscles were correlated with acute and late dysphagia and with the items of three quality of life questionnaires. Results: Mean dose to superior and middle constrictor muscles (SCM, MCM), partial volume of SCM and MCM receiving a dose ≥ 50 Gy dose to the whole constrictor muscles ≥ 60 Gy and tumour location were associated to late dysphagia at univariate analysis. Mean dose to the MCM was the only statistically significant predictor of late dysphagia at the multivariable analysis. Conclusion: The study shows a significant relationship between long-term dysphagia and mean doses to SCM, MCM, whole constrictor muscles, and oropharyngeal tumour. This finding suggests a potential advantage in reducing the RT dose to swallowing structures to avoid severe dysphagia. (orig.)
On the Convergence and Law of Large Numbers for the Non-Euclidean Lp -Means
Directory of Open Access Journals (Sweden)
George Livadiotis
2017-05-01
Full Text Available This paper describes and proves two important theorems that compose the Law of Large Numbers for the non-Euclidean L p -means, known to be true for the Euclidean L 2 -means: Let the L p -mean estimator, which constitutes the specific functional that estimates the L p -mean of N independent and identically distributed random variables; then, (i the expectation value of the L p -mean estimator equals the mean of the distributions of the random variables; and (ii the limit N → ∞ of the L p -mean estimator also equals the mean of the distributions.
Intrinsic Regularization in a Lorentz invariant non-orthogonal Euclidean Space
Tornow, Carmen
2006-01-01
It is shown that the Lorentz transformations can be derived for a non-orthogonal Euclidean space. In this geometry one finds the same relations of special relativity as the ones known from the orthogonal Minkowski space. In order to illustrate the advantage of a non-orthogonal Euclidean metric the two-point Green’s function at x = 0 for a self-interacting scalar field is calculated. In contrast to the Minkowski space the one loop mass correction derived from this function gives a convergent r...
Scalar Green's functions in an Euclidean space with a conical-type line singularity
International Nuclear Information System (INIS)
Guimaraes, M.E.X.; Linet, B.
1994-01-01
In an Euclidean space with a conical-type line singularity, we determine the Green's function for a charged massive scalar field interacting with a magnetic flux running through the line singularity. We give an integral expression of the Green's function and a local form in the neighbourhood of the point source, where it is the sum of the usual Green's function in Euclidean space and a regular term. As an application, we derive the vacuum energy-momentum tensor in the massless case for an arbitrary magnetic flux. (orig.)
Products of Snowflaked Euclidean Lines Are Not Minimal for Looking Down
Directory of Open Access Journals (Sweden)
Joseph Matthieu
2017-11-01
Full Text Available We show that products of snowflaked Euclidean lines are not minimal for looking down. This question was raised in Fractured fractals and broken dreams, Problem 11.17, by David and Semmes. The proof uses arguments developed by Le Donne, Li and Rajala to prove that the Heisenberg group is not minimal for looking down. By a method of shortcuts, we define a new distance d such that the product of snowflaked Euclidean lines looks down on (RN , d, but not vice versa.
Correlation of radon volume activity in bedrock and in drinking water
International Nuclear Information System (INIS)
Barnet, I.
1993-01-01
Derived radon risk maps set up by the Czech Geological Institute can be applied with advantage when seeking out regions with a high probability of radon occurrence in drinking water at concentrations exceeding regulatory limits. Data of radon concentrations in drinking water sources as obtained from health physics stations were used to calculate the average values for various rock types and to compare them with soil air radon data for the same sites. The two sets of data were found to correlate. The measurements concerned southern and eastern Bohemia. (M.D.). 4 tabs., 3 figs
Abdelsattar, Jad M; AlJamal, Yazan N; Ruparel, Raaj K; Rowse, Phillip G; Heller, Stephanie F; Farley, David R
2018-05-14
Faculty evaluations, ABSITE scores, and operative case volumes often tell little about true resident performance. We developed an objective structured clinical examination called the Surgical X-Games (5 rooms, 15 minutes each, 12-15 tests total, different for each postgraduate [PGY] level). We hypothesized that performance in X-Games will prove more useful in identifying areas of strength or weakness among general surgery (GS) residents than faculty evaluations, ABSITE scores, or operative cases volumes. PGY 2 to 5 GS residents (n = 35) were tested in a semiannual X-Games assessment using multiple simulation tasks: laparoscopic skills, bowel anastomosis, CT/CXR analysis, chest tube placement, etc. over 1 academic year. Resident scores were compared to their ABSITE, in-training evaluation reports, and operating room case numbers. Academic medical center. PGY-2, 3, 4, and 5 GS residents at Mayo Clinic in Rochester, MN. Results varied greatly within each class except for staff evaluations: in-training evaluation reports medians for PGY-2s were 5.3 (range: 5.0-6.0), PGY-3s 5.9 (5.5-6.3), PGY-4s 5.6 (5.0-6.0), and PGY-5s were 6.1 (5.6-6.9). Although ABSITE and operating room case volumes fluctated greatly with each PGY class, only X-Games scores (median: PGY-2 = 82, PGY-3 = 61, PGY-4 = 76, and PGY-5 = 60) correlated positively (p < 0.05) with operative case volume and negatively (p < 0.05) with staff evaluations. X-Games assessment generated wide differentiation of resident performance quickly, inexpensively, and objectively. Although "Minnesota-nice" surgical staff may feel all GS trainees are "above average," objective assessment tells us otherwise. Copyright © 2018 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.
International Nuclear Information System (INIS)
Xyda, Argyro; Haberland, Ulrike; Klotz, Ernst; Jung, Klaus; Bock, Hans Christoph; Schramm, Ramona; Knauth, Michael; Schramm, Peter
2012-01-01
Background: To evaluate the preoperative diagnostic power and classification accuracy of perfusion parameters derived from whole brain volume perfusion CT (VPCT) in patients with cerebral tumors. Methods: Sixty-three patients (31 male, 32 female; mean age 55.6 ± 13.9 years), with MRI findings suspected of cerebral lesions, underwent VPCT. Two readers independently evaluated VPCT data. Volumes of interest (VOIs) were marked circumscript around the tumor according to maximum intensity projection volumes, and then mapped automatically onto the cerebral blood volume (CBV), flow (CBF) and permeability Ktrans perfusion datasets. A second VOI was placed in the contra lateral cortex, as control. Correlations among perfusion values, tumor grade, cerebral hemisphere and VOIs were evaluated. Moreover, the diagnostic power of VPCT parameters, by means of positive and negative predictive value, was analyzed. Results: Our cohort included 32 high-grade gliomas WHO III/IV, 18 low-grade I/II, 6 primary cerebral lymphomas, 4 metastases and 3 tumor-like lesions. Ktrans demonstrated the highest sensitivity, specificity and positive predictive value, with a cut-off point of 2.21 mL/100 mL/min, for both the comparisons between high-grade versus low-grade and low-grade versus primary cerebral lymphomas. However, for the differentiation between high-grade and primary cerebral lymphomas, CBF and CBV proved to have 100% specificity and 100% positive predictive value, identifying preoperatively all the histopathologically proven high-grade gliomas. Conclusion: Volumetric perfusion data enable the hemodynamic assessment of the entire tumor extent and provide a method of preoperative differentiation among intra-axial cerebral tumors with promising diagnostic accuracy.
Mixed Volume and Distance Geometry Techniques for Counting Euclidean Embeddings of Rigid Graphs
I.Z. Emiris; E.P. Tsigaridas; A. Varvitsiotis (Antonios); A. Mucherino (Antonio); C. Lavor; L. Liberti; N. Maculan
2013-01-01
htmlabstractA graph G is called generically minimally rigid in Rd if, for any choice of sufficiently generic edge lengths, it can be embedded in Rd in a finite number of distinct ways, modulo rigid transformations. Here, we deal with the problem of determining tight bounds on the number of such
Euclidean Dynamical Triangulation revisited: is the phase transition really 1st order?
International Nuclear Information System (INIS)
Rindlisbacher, Tobias; Forcrand, Philippe de
2015-01-01
The transition between the two phases of 4D Euclidean Dynamical Triangulation (http://dx.doi.org/10.1016/0370-2693(92)90709-D) was long believed to be of second order until in 1996 first order behavior was found for sufficiently large systems (http://dx.doi.org/10.1016/0550-3213(96)00214-3, http://dx.doi.org/10.1016/S0370-2693(96)01277-4). However, one may wonder if this finding was affected by the numerical methods used: to control volume fluctuations, in both studies (http://dx.doi.org/10.1016/0550-3213(96)00214-3, http://dx.doi.org/10.1016/S0370-2693(96)01277-4) an artificial harmonic potential was added to the action and in (http://dx.doi.org/10.1016/S0370-2693(96)01277-4) measurements were taken after a fixed number of accepted instead of attempted moves which introduces an additional error. Finally the simulations suffer from strong critical slowing down which may have been underestimated. In the present work, we address the above weaknesses: we allow the volume to fluctuate freely within a fixed interval; we take measurements after a fixed number of attempted moves; and we overcome critical slowing down by using an optimized parallel tempering algorithm (http://dx.doi.org/10.1088/1742-5468/2010/01/P01020). With these improved methods, on systems of size up to N_4=64k 4-simplices, we confirm that the phase transition is 1"s"t order. In addition, we discuss a local criterion to decide whether parts of a triangulation are in the elongated or crumpled state and describe a new correspondence between EDT and the balls in boxes model. The latter gives rise to a modified partition function with an additional, third coupling. Finally, we propose and motivate a class of modified path-integral measures that might remove the metastability of the Markov chain and turn the phase transition into 2"n"d order.
International Nuclear Information System (INIS)
Yeo, Seung-Gu; Kim, Dae Yong; Kim, Tae Hyun; Jung, Kyung Hae; Hong, Yong Sang; Chang, Hee Jin; Park, Ji Won; Lim, Seok-Byung; Choi, Hyo Seong; Jeong, Seung-Yong
2010-01-01
Purpose: To determine whether the tumor volume reduction rate (TVRR) measured using three-dimensional region-of-interest magnetic resonance volumetry correlates with the pathologic tumor response after preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer. Methods and Materials: The study included 405 patients with locally advanced rectal cancer (cT3-T4) who had undergone preoperative CRT and radical proctectomy. The tumor volume was measured using three-dimensional region-of-interest magnetic resonance volumetry before and after CRT but before surgery. We analyzed the correlation between the TVRR and the pathologic tumor response in terms of downstaging and tumor regression grade (TRG). Downstaging was defined as ypStage 0-I (ypT0-T2N0M0), and the TRG proposed by Dworak et al. was used. Results: The mean TVRR was 65.0% ± 22.3%. Downstaging and complete regression occurred in 167 (41.2%) and 58 (14.3%) patients, respectively. The TVRRs according to ypT classification (ypT0-T2 vs. ypT3-T4), ypN classification (ypN0 vs. ypN1-N2), downstaging (ypStage 0-I vs. ypStage II-III), good regression (TRG 3-4 vs. TRG 1-2), and complete regression (TRG 4 vs. TRG 1-3) were all significantly different (p 80%), the rates of ypT0-T2, ypN0, downstaging, and good regression were all significantly greater for patients with a TVRR of ≥60%, as was the complete regression rate for patients with a TVRR >80% (p <.05). Conclusion: The TVRR measured using three-dimensional region-of-interest magnetic resonance volumetry correlated significantly with the pathologic tumor response in terms of downstaging and TRG after preoperative CRT for locally advanced rectal cancer.
Devine, Oliver Patrick; Harborne, Andrew Christopher; McManus, I C
2015-09-11
In the United Kingdom (UK), medical schools are free to develop local systems and policies that govern student assessment and progression. Successful completion of an undergraduate medical degree results in the automatic award of a provisional licence to practice medicine by the General Medical Council (GMC). Such a licensing process relies heavily on the assumption that individual schools develop similarly rigorous assessment policies. Little work has evaluated variability of undergraduate medical assessment between medical schools. That absence is important in the light of the GMC's recent announcement of the introduction of the UKMLA (UK Medical Licensing Assessment) for all doctors who wish to practise in the UK. The present study aimed to quantify and compare the volume, type and intensity of summative assessment across medicine (A100) courses in the United Kingdom, and to assess whether intensity of assessment correlates with the postgraduate attainment of doctors from these schools. Locally knowledgeable students in each school were approached to take part in guided-questionnaire interviews via telephone or Skype(TM). Their understanding of assessment at their medical school was probed, and later validated with the assessment department of the respective medical school. We gathered data for 25 of 27 A100 programmes in the UK and compared volume, type and intensity of assessment between schools. We then correlated these data with the mean first-attempt score of graduates sitting MRCGP and MRCP(UK), as well as with UKFPO selection measures. The median written assessment volume across all schools was 2000 min (mean = 2027, SD = 586, LQ = 1500, UQ = 2500, range = 1000-3200) and 1400 marks (mean = 1555, SD = 463, LQ = 1200, UQ = 1800, range = 1100-2800). The median practical assessment volume was 400 min (mean = 472, SD = 207, LQ = 400, UQ = 600, range = 200-1000). The median intensity (minutes per mark ratio) of summative written assessment was 1.24 min per mark
Chung, Hui-Kuan; Tymula, Agnieszka; Glimcher, Paul
2017-12-06
The population of people above 65 years old continues to grow, and there is mounting evidence that as humans age they are more likely to make errors. However, the specific effect of neuroanatomical aging on the efficiency of economic decision-making is poorly understood. We used whole-brain voxel-based morphometry analysis to determine where reduction of gray matter volume in healthy female and male adults over the age of 65 years correlates with a classic measure of economic irrationality: violations of the Generalized Axiom of Revealed Preference. All participants were functionally normal with Mini-Mental State Examination scores ranging between 26 and 30. While our elders showed the previously reported decline in rationality compared with younger subjects, chronological age per se did not correlate with rationality measures within our population of elders. Instead, reduction of gray matter density in ventrolateral prefrontal cortex correlates tightly with irrational behavior. Interestingly, using a large fMRI sample and meta-analytic tool with Neurosynth, we found that this brain area shows strong coactivation patterns with nearly all of the value-associated regions identified in previous studies. These findings point toward a neuroanatomic locus for economic rationality in the aging brain and highlight the importance of understanding both anatomy and function in the study of aging, cognition, and decision-making. SIGNIFICANCE STATEMENT Age is a crucial factor in decision-making, with older individuals making more errors in choices. Using whole-brain voxel-based morphometry analysis, we found that reduction of gray matter density in ventrolateral prefrontal cortex correlates with economic irrationality: reduced gray matter volume in this area correlates with the frequency and severity of violations of the Generalized Axiom of Revealed Preference. Furthermore, this brain area strongly coactivates with other reward-associated regions identified with Neurosynth
Tan, Zhiyuan; Jamdagni, Aruna; He, Xiangjian; Nanda, Priyadarsi; Liu, Ren Ping; Qing, Sihan; Susilo, Willy; Wang, Guilin; Liu, Dongmei
2011-01-01
The quality of feature has significant impact on the performance of detection techniques used for Denial-of-Service (DoS) attack. The features that fail to provide accurate characterization for network traffic records make the techniques suffer from low accuracy in detection. Although researches
International Nuclear Information System (INIS)
Kiskis, J.; Narayanan, R.; Vranas, P.
1993-01-01
The authors study the random walk representation of the two-point function in statistical mechanics models near the critical point. Using standard scaling arguments, the authors show that the critical exponent v describing the vanishing of the physical mass at the critical point is equal to v θ /d w , where d w is the Hausdorff dimension of the walk, and v θ = var-phi, where var-phi is the crossover exponent known in the context of field theory. This implies that the Hausdorff dimension of the walk is var-phi/v for O(N) models. 3 refs
On Euclidean connections for su(1,1), suq(1,1) and the algebraic approach to scattering
International Nuclear Information System (INIS)
Ionescu, R.A.
1994-11-01
We obtain a general Euclidean connection for su(1,1) and suq(1,1) algebras. Our Euclidean connection allows an algebraic derivation for the S matrix. These algebraic S matrices reduce to the known ones in suitable circumstances. Also, we obtain a map between su(1,1) and su q (1,1) representations. (author). 8 refs
International Nuclear Information System (INIS)
Arimoto, Hiroshi; Yamamoto, Kazuhiro; Yamaguchi, Hiroyuki; Terai, Yoshito; Ohmichi, Masahide; Narabayashi, Isamu
2007-01-01
The objective of this study was to evaluate the correlations of leiomyoma volume reduction with the perfusion pattern of leiomyomas and signal intensity on T2-weighted images. Magnetic resonance (MR) imaging was performed on 11 patients with 35 symptomatic uterine leiomyomas before and 3 and 6 months after uterine artery embolization (UAE). The correlation between leiomyoma perfusion pattern and percent leiomyoma volume reduction was assessed. The mean percent leiomyoma volume reductions were 41.1% 3 months and 58.4% 6 months after UAE. The mean percent volume reductions of highly perfused leiomyomas were 58.6% 3 months and 85.7% 6 months after UAE. The reduction rates of poorly perfused leiomyomas were 37.9% 3 months and 49.1% 6 months after UAE. Well-perfused leiomyomas are more likely to reduce in leiomyoma volume. It is thought that a patient with a well-perfusion myoma is a good candidate for UAE. (author)
DEFF Research Database (Denmark)
Posthuma, Daniëlle; Baare, Wim F.C.; Hulshoff Pol, Hilleke E.
2003-01-01
We recently showed that the correlation of gray and white matter volume with full scale IQ and the Working Memory dimension are completely mediated by common genetic factors (Posthuma et al., 2002). Here we examine whether the other WAIS III dimensions (Verbal Comprehension, Perceptual Organization......, Processing Speed) are also related to gray and white matter volume, and whether any of the dimensions are related to cerebellar volume. Two overlapping samples provided 135 subjects from 60 extended twin families for whom both MRI scans and WAIS III data were available. All three brain volumes are related...... to Working Memory capacity (r = 0.27). This phenotypic correlation is completely due to a common underlying genetic factor. Processing Speed was genetically related to white matter volume (r(g) = 0.39). Perceptual Organization was both genetically (r(g) = 0.39) and environmentally (r(e) = -0.71) related...
Ferguson, Connor R.; Lee, Stuart M. C.; Stenger, Michael B.; Platts, Steven H.; Laurie, Steven S.
2014-01-01
Orthostatic intolerance affects 60-80% of astronauts returning from long-duration missions, representing a significant risk to completing mission-critical tasks. While likely multifactorial, a reduction in stroke volume (SV) represents one factor contributing to orthostatic intolerance during stand and head up tilt (HUT) tests. Current measures of SV during stand or HUT tests use Doppler ultrasound and require a trained operator and specialized equipment, restricting its use in the field. BeatScope (Finapres Medical Systems BV, The Netherlands) uses a modelflow algorithm to estimate SV from continuous blood pressure waveforms in supine subjects; however, evidence supporting the use of Modelflow to estimate SV in subjects completing stand or HUT tests remain scarce. Furthermore, because the blood pressure device is held extended at heart level during HUT tests, but allowed to rest at the side during stand tests, changes in the finger arterial pressure waveform resulting from arm positioning could alter modelflow estimated SV. The purpose of this project was to compare Doppler ultrasound and BeatScope estimations of SV to determine if BeatScope can be used during stand or HUT tests. Finger photoplethysmography was used to acquire arterial pressure waveforms corrected for hydrostatic finger-to-heart height using the Finometer (FM) and Portapres (PP) arterial pressure devices in 10 subjects (5 men and 5 women) during a stand test while simultaneous estimates of SV were collected using Doppler ultrasound. Measures were made after 5 minutes of supine rest and while subjects stood for 5 minutes. Next, SV estimates were reacquired while each arm was independently raised to heart level, a position similar to tilt testing. Supine SV estimates were not significantly different between all three devices (FM: 68+/-20, PP: 71+/-21, US: 73+/-21 ml/beat). Upon standing, the change in SV estimated by FM (-18+/-8 ml) was not different from PP (-21+/-12), but both were significantly
Imaging transient blood vessel fusion events in zebrafish by correlative volume electron microscopy.
Directory of Open Access Journals (Sweden)
Hannah E J Armer
Full Text Available The study of biological processes has become increasingly reliant on obtaining high-resolution spatial and temporal data through imaging techniques. As researchers demand molecular resolution of cellular events in the context of whole organisms, correlation of non-invasive live-organism imaging with electron microscopy in complex three-dimensional samples becomes critical. The developing blood vessels of vertebrates form a highly complex network which cannot be imaged at high resolution using traditional methods. Here we show that the point of fusion between growing blood vessels of transgenic zebrafish, identified in live confocal microscopy, can subsequently be traced through the structure of the organism using Focused Ion Beam/Scanning Electron Microscopy (FIB/SEM and Serial Block Face/Scanning Electron Microscopy (SBF/SEM. The resulting data give unprecedented microanatomical detail of the zebrafish and, for the first time, allow visualization of the ultrastructure of a time-limited biological event within the context of a whole organism.
The positive action conjecture and asymptotically euclidean metrics in quantum gravity
International Nuclear Information System (INIS)
Gibbons, G.W.; Pope, C.N.
1979-01-01
The positive action conjecture requires that the action of any asymptotically Euclidean 4-dimensional Riemannian metric be positive, vanishing if and only if the space is flat. Because any Ricci flat, asymptotically Euclidean metric has zero action and is local extremum of the action which is a local minimum at flat space, the conjecture requires that there are no Ricci flat asymptotically Euclidean metrics other than flat space, which would establish that flat space is the only local minimum. We prove this for metrics on R 4 and a large class of more complicated topologies and for self-dual metrics. We show that if Rsupμsubμ >= 0 there are no bound states of the Dirac equation and discuss the relevance to possible baryon non-conserving processes mediated by gravitational instantons. We conclude that these are forbidden in the lowest stationary phase approximation. We give a detailed discussion of instantons invariant under an SU(2) or SO(3) isometry group. We find all regular solutions, none of which is asymptotically Euclidean and all of which possess a further Killing vector. In an appendix we construct an approximate self-dual metric on K3 - the only simply connected compact manifold which admits a self-dual metric. (orig.) [de
Usability Evaluation of an Augmented Reality System for Teaching Euclidean Vectors
Martin-Gonzalez, Anabel; Chi-Poot, Angel; Uc-Cetina, Victor
2016-01-01
Augmented reality (AR) is one of the emerging technologies that has demonstrated to be an efficient technological tool to enhance learning techniques. In this paper, we describe the development and evaluation of an AR system for teaching Euclidean vectors in physics and mathematics. The goal of this pedagogical tool is to facilitate user's…
Rooij, van I.; Stege, U.; Schactman, A.
2003-01-01
Recently there has been growing interest among psychologists in human performance on the Euclidean traveling salesperson problem (E-TSP). A debate has been initiated on what strategy people use in solving visually presented E-TSP instances. The most prominent hypothesis is the convex-hull
International Nuclear Information System (INIS)
Pordt, A.
1985-10-01
The author describes the Mayer expansion in Euclidean lattice field theory by comparing it with the statistical mechanics of polymer systems. In this connection he discusses the Borel summability and the analyticity of the activities on the lattice. Furthermore the relations between renormalization and the Mayer expansion are considered. (HSI)
Fast Exact Euclidean Distance (FEED): A new class of adaptable distance transforms
Schouten, Theo E.; van den Broek, Egon
2014-01-01
A new unique class of foldable distance transforms of digital images (DT) is introduced, baptized: Fast Exact Euclidean Distance (FEED) transforms. FEED class algorithms calculate the DT starting directly from the definition or rather its inverse. The principle of FEED class algorithms is
Fast Exact Euclidean Distance (FEED) : A new class of adaptable distance transforms
Schouten, Theo E.; van den Broek, Egon L.
2014-01-01
A new unique class of foldable distance transforms of digital images (DT) is introduced, baptized: Fast Exact Euclidean Distance (FEED) transforms. FEED class algorithms calculate the DT startingdirectly from the definition or rather its inverse. The principle of FEED class algorithms is introduced,
Loci of points in the Euclidean plane are deter- mined from ...
Indian Academy of Sciences (India)
Loci of points in the Euclidean plane are deter- mined from prescribed relations of the points with given points, and/or, lines. The depen- dence of these relations on parameters lead to the differential equations representing the fam- ily of loci under concern. Incidentally most of the differential equations thus obtained are non ...
Faster exact algorithms for computing Steiner trees in higher dimensional Euclidean spaces
DEFF Research Database (Denmark)
Fonseca, Rasmus; Brazil, Marcus; Winter, Pawel
The Euclidean Steiner tree problem asks for a network of minimum total length interconnecting a finite set of points in d-dimensional space. For d ≥ 3, only one practical algorithmic approach exists for this problem --- proposed by Smith in 1992. A number of refinements of Smith's algorithm have...
Non-Euclidean spacetime structure and the two-slit experiment
International Nuclear Information System (INIS)
El Naschie, M.S.
2005-01-01
A simple mathematical model for the two-slit experiment is given to account for the wave-particle duality. Subsequently, the various solutions are interpreted via the experimental evidence as a property of the underlying non-Euclidean spacetime topology and geometry at the quantum level
Characterizations of Space Curves According to Bishop Darboux Vector in Euclidean 3-Space E3
Huseyin KOCAYIGIT; Ali OZDEMIR
2014-01-01
In this paper, we obtained some characterizations of space curves according to Bihop frame in Euclidean 3-space E3 by using Laplacian operator and Levi-Civita connection. Furthermore, we gave the general differential equations which characterize the space curves according to the Bishop Darboux vector and the normal Bishop Darboux vector.
Hadwin, Paul J.; Sipkens, T. A.; Thomson, K. A.; Liu, F.; Daun, K. J.
2016-01-01
Auto-correlated laser-induced incandescence (AC-LII) infers the soot volume fraction (SVF) of soot particles by comparing the spectral incandescence from laser-energized particles to the pyrometrically inferred peak soot temperature. This calculation requires detailed knowledge of model parameters such as the absorption function of soot, which may vary with combustion chemistry, soot age, and the internal structure of the soot. This work presents a Bayesian methodology to quantify such uncertainties. This technique treats the additional "nuisance" model parameters, including the soot absorption function, as stochastic variables and incorporates the current state of knowledge of these parameters into the inference process through maximum entropy priors. While standard AC-LII analysis provides a point estimate of the SVF, Bayesian techniques infer the posterior probability density, which will allow scientists and engineers to better assess the reliability of AC-LII inferred SVFs in the context of environmental regulations and competing diagnostics.
Ohira, Masahiro; Ishifuro, Minoru; Ide, Kentaro; Irei, Toshimitsu; Tashiro, Hirotaka; Itamoto, Toshiyuki; Ito, Katsuhide; Chayama, Kazuaki; Asahara, Toshimasa; Ohdan, Hideki
2009-02-01
Interferon (IFN) therapy with or without ribavirin treatment is well established as a standard antiviral treatment for hepatitis C virus (HCV)-infected patients. However, susceptibility to thrombocytopenia is a major obstacle for initiating or continuing this therapy, particularly in liver transplant (LTx) recipients with HCV. Studies have reported that splenectomy performed concurrently with LTx is a feasible strategy for conditioning patients for anti-HCV IFN therapy. However, the relationship between the severity of splenomegaly and alterations in the blood cytopenia in LTx recipients remains to be clarified. Here, we analyzed the relationship between spleen volume (SV) and thrombocytopenia in 45 patients who underwent LTx at Hiroshima University Hospital. The extent of pre-LTx splenomegaly [the SV to body surface area (BSA) ratio in an individual] was inversely correlated with both the post-LTx white blood cell count and platelet (PLT) count (P or= 400), persistent thrombocytopenia is predictable after LTx. (c) 2009 AASLD.
Hanssen, Andrés; Plotnikov, Sergio; Acosta, Geylor; Nuñez, José Tomas; Haddad, José; Rodriguez, Carmen; Petrucci, Claudia; Hanssen, Diego; Hanssen, Rafael
2018-03-01
The volume of the postoperative gastric remnant is a key factor in excess weight loss (EWL) after sleeve gastrectomy (SG). Traditional methods to estimate gastric volume (GV) after bariatric procedures are often inaccurate; usually conventional biplanar contrast studies are used. Thirty patients who underwent SG were followed prospectively and evaluated at 6 months after the surgical procedure, performing 3D CT reconstruction and gastric volumetry, to establish its relationship with EWL. The gastric remnant was distended with effervescent sodium bicarbonate given orally. Helical CT images were acquired and reconstructed; GV was estimated with the software of the CT device. The relationship between GV and EWL was analyzed. The study allowed estimating the GV in all patients. A dispersion diagram showed an inverse relationship between GV and %EWL. 55.5% of patients with GV ≤ 100 ml had %EWL 25-75% and 38.8% had an %EWL above 75% and patients with GV ≥ 100 ml had an %EWL under 25% (50% of patients) or between 25 and 75% (50% of this group). The Pearson's correlation coefficient was R = 6.62, with bilateral significance (p ≤ .01). The Chi-square result correlating GV and EWL showed a significance of .005 (p ≤ .01). The 3D reconstructions showed accurately the shape and anatomic details of the gastric remnant. 3D volumetry CT scans accurately estimate GV after SG. A significant relationship between GV and EWL 6 months after SG was established, seeming that GV ≥ 100 ml at 6 months of SG is associated with poor EWL.
Ovanesyan, Zaven; Aljzmi, Amal; Almusaynid, Manal; Khan, Asrar; Valderrama, Esteban; Nash, Kelly L; Marucho, Marcelo
2016-01-15
One major source of complexity in the implementation of nanoparticles in aqueous electrolytes arises from the strong influence that biological environments has on their physicochemical properties. A key parameter for understanding the molecular mechanisms governing the physicochemical properties of nanoparticles is the formation of the surface charge density. In this article, we present an efficient and accurate approach that combines a recently introduced classical solvation density functional theory for spherical electrical double layers with a surface complexation model to account for ion-ion correlation and excluded volume effects on the surface titration of spherical nanoparticles. We apply the proposed computational approach to account for the charge-regulated mechanisms on the surface chemistry of spherical silica (SiO2) nanoparticles. We analyze the effects of the nanoparticle size, as well as pH level and electrolyte concentration of the aqueous solution on the nanoparticle's surface charge density and Zeta potential. We validate our predictions for 580Å and 200Å nanoparticles immersed in acid, neutral and alkaline mono-valent aqueous electrolyte solutions against experimental data. Our results on mono-valent electrolyte show that the excluded volume and ion-ion correlations contribute significantly to the surface charge density and Zeta potential of the nanoparticle at high electrolyte concentration and pH levels, where the solvent crowding effects and electrostatic screening have shown a profound influence on the protonation/deprotonation reactions at the liquid/solute interface. The success of this approach in describing physicochemical properties of silica nanoparticles supports its broader application to study other spherical metal oxide nanoparticles. Copyright © 2015 Elsevier Inc. All rights reserved.
International Nuclear Information System (INIS)
Go, R.T.; MacIntyre, W.J.; Yeung, H.N.
1984-01-01
Magnetic resonance (MR) gated cardiac imaging was performed in ten subjects using a prototype 0.15-T resistive magnet imaging system. Volume and planar imaging techniques utilizing saturation recovery, proton TI-weighted relaxation time pulse sequences produced images of the heart and great vessels with exquisite anatomic detail that showed excellent correlation with cadaver sections of the heart. The left ventricular myocardial segments also showed excellent correlation with cadaver sections of the heart. The left ventricular myocardial segments also showed excellent correlation with the thallium-201 cardiac single photon emission computed tomography images. Volume acquisition allowed postprocessing selection of tomographic sections in various orientations to optimize visualization of a particular structure of interest. The excellent spatial and contrast resolution afforded by MR volume imaging, which does not involve the use of ionizing radiation and iodinated contrast material, should assure it a significant role in the diagnostic assessment of the cardiovascular system
DEFF Research Database (Denmark)
Sørensen, Belinda Halling; Thorsteinsdottir, Unnur Arna; Lambert, Ian Henry
2014-01-01
Cisplatin resistance is a major challenge in the treatment of cancer and develops through reduced drug accumulation and an increased ability to avoid drug-induced cell damage, cell shrinkage, and hence initiation of apoptosis. Uptake and release of the semiessential amino acid taurine contribute...... to cell volume homeostasis, and taurine has been reported to have antiapoptotic effects. Here we find that volume-sensitive taurine release in cisplatin-sensitive [wild-type (WT)] human ovarian cancer A2780 cells is reduced in the presence of the phospholipase A2 inhibitor bromenol lactone, the 5......-induced cell death in RES A2780 cells correlates with an increased accumulation of taurine, due to an increased taurine uptake and a concomitant impairment of the volume-sensitive taurine release pathway, as well an inability to reduce cell volume after osmotic cell swelling. Downregulation of volume...
Lee, Chan Ho; Park, Young Joo; Ku, Ja Yoon; Ha, Hong Koo
2017-06-01
To evaluate the clinical application of computed tomography-based measurement of renal cortical volume and split renal volume as a single tool to assess the anatomy and renal function in patients with renal tumors before and after partial nephrectomy, and to compare the findings with technetium-99m dimercaptosuccinic acid renal scan. The data of 51 patients with a unilateral renal tumor managed by partial nephrectomy were retrospectively analyzed. The renal cortical volume of tumor-bearing and contralateral kidneys was measured using ImageJ software. Split estimated glomerular filtration rate and split renal volume calculated using this renal cortical volume were compared with the split renal function measured with technetium-99m dimercaptosuccinic acid renal scan. A strong correlation between split renal function and split renal volume of the tumor-bearing kidney was observed before and after surgery (r = 0.89, P volumetry had a strong correlation with the split renal function measured using technetium-99m dimercaptosuccinic acid renal scan. Computed tomography-based split renal volume measurement before and after partial nephrectomy can be used as a single modality for anatomical and functional assessment of the tumor-bearing kidney. © 2017 The Japanese Urological Association.
DEFF Research Database (Denmark)
Posthuma, Daniëlle; Baare, Wim F.C.; Hulshoff Pol, Hilleke E.
2003-01-01
We recently showed that the correlation of gray and white matter volume with full scale IQ and the Working Memory dimension are completely mediated by common genetic factors (Posthuma et al., 2002). Here we examine whether the other WAIS III dimensions (Verbal Comprehension, Perceptual Organization...... to Working Memory capacity (r = 0.27). This phenotypic correlation is completely due to a common underlying genetic factor. Processing Speed was genetically related to white matter volume (r(g) = 0.39). Perceptual Organization was both genetically (r(g) = 0.39) and environmentally (r(e) = -0.71) related...
Singular Minkowski and Euclidean solutions for SU(2) Yang-Mills theory
International Nuclear Information System (INIS)
Singleton, D.
1996-01-01
In this paper it is examined a solution to the SU(2) Yang-Mills-Higgs system, which is a trivial mathematical extension of recently discovered Schwarzschild- like solutions (Singleton D., Phys. Rev. D, 51 (1955) 5911). Physically, however, this new solution has drastically different properties from the Schwarzschild-like solutions. It is also studied a new classical solution for Euclidean SU(2) Yang-Mills theory. Again this new solution is a mathematically trivial extension of the Belavin-Polyakov-Schwartz-Tyupkin (BPST) (Belavin A. A. et al., Phys. Lett. B, 59 (1975) 85) instanton, but is physically very different. Unlike the usual instanton solution, the present solution is singular on a sphere of arbitrary radius in Euclidean space. Both of these solutions are infinite-energy solutions, so their practical value is somewhat unclear. However, they may be useful in exploring some of the mathematical aspects of classical Yang-Mills theory
Membrane paradigm and entropy of black holes in the Euclidean action approach
International Nuclear Information System (INIS)
Lemos, Jose P. S.; Zaslavskii, Oleg B.
2011-01-01
The membrane paradigm approach to black holes fixes in the vicinity of the event horizon a fictitious surface, the stretched horizon, so that the spacetime outside remains unchanged and the spacetime inside is vacuum. Using this powerful method, several black hole properties have been found and settled, such as the horizon's viscosity, electrical conductivity, resistivity, as well as other properties. On the other hand, the Euclidean action approach to black hole spacetimes has been very fruitful in understanding black hole entropy. Combining both the Euclidean action and membrane paradigm approaches, a direct derivation of the black hole entropy is given. In the derivation, it is considered that the only fields present are the gravitational and matter fields, with no electric field.
A Low-Complexity Euclidean Orthogonal LDPC Architecture for Low Power Applications
Directory of Open Access Journals (Sweden)
M. Revathy
2015-01-01
Full Text Available Low-density parity-check (LDPC codes have been implemented in latest digital video broadcasting, broadband wireless access (WiMax, and fourth generation of wireless standards. In this paper, we have proposed a high efficient low-density parity-check code (LDPC decoder architecture for low power applications. This study also considers the design and analysis of check node and variable node units and Euclidean orthogonal generator in LDPC decoder architecture. The Euclidean orthogonal generator is used to reduce the error rate of the proposed LDPC architecture, which can be incorporated between check and variable node architecture. This proposed decoder design is synthesized on Xilinx 9.2i platform and simulated using Modelsim, which is targeted to 45 nm devices. Synthesis report proves that the proposed architecture greatly reduces the power consumption and hardware utilizations on comparing with different conventional architectures.
A Low-Complexity Euclidean Orthogonal LDPC Architecture for Low Power Applications.
Revathy, M; Saravanan, R
2015-01-01
Low-density parity-check (LDPC) codes have been implemented in latest digital video broadcasting, broadband wireless access (WiMax), and fourth generation of wireless standards. In this paper, we have proposed a high efficient low-density parity-check code (LDPC) decoder architecture for low power applications. This study also considers the design and analysis of check node and variable node units and Euclidean orthogonal generator in LDPC decoder architecture. The Euclidean orthogonal generator is used to reduce the error rate of the proposed LDPC architecture, which can be incorporated between check and variable node architecture. This proposed decoder design is synthesized on Xilinx 9.2i platform and simulated using Modelsim, which is targeted to 45 nm devices. Synthesis report proves that the proposed architecture greatly reduces the power consumption and hardware utilizations on comparing with different conventional architectures.
The non-Euclidean revolution with an introduction by H.S.M. Coxeter
Trudeau, Richard J
2001-01-01
How unique and definitive is Euclidean geometry in describing the "real" space in which we live? Richard Trudeau confronts the fundamental question of truth and its representation through mathematical models in The Non-Euclidean Revolution. First, the author analyzes geometry in its historical and philosophical setting; second, he examines a revolution every bit as significant as the Copernican revolution in astronomy and the Darwinian revolution in biology; third, on the most speculative level, he questions the possibility of absolute knowledge of the world. Trudeau writes in a lively, entertaining, and highly accessible style. His book provides one of the most stimulating and personal presentations of a struggle with the nature of truth in mathematics and the physical world. A portion of the book won the Pólya Prize, a distinguished award from the Mathematical Association of America.
Modelling non-Euclidean movement and landscape connectivity in highly structured ecological networks
Sutherland, Christopher; Fuller, Angela K.; Royle, J. Andrew
2015-01-01
Movement is influenced by landscape structure, configuration and geometry, but measuring distance as perceived by animals poses technical and logistical challenges. Instead, movement is typically measured using Euclidean distance, irrespective of location or landscape structure, or is based on arbitrary cost surfaces. A recently proposed extension of spatial capture-recapture (SCR) models resolves this issue using spatial encounter histories of individuals to calculate least-cost paths (ecological distance: Ecology, 94, 2013, 287) thereby relaxing the Euclidean assumption. We evaluate the consequences of not accounting for movement heterogeneity when estimating abundance in highly structured landscapes, and demonstrate the value of this approach for estimating biologically realistic space-use patterns and landscape connectivity.
From Euclidean to Minkowski space with the Cauchy-Riemann equations
International Nuclear Information System (INIS)
Gimeno-Segovia, Mercedes; Llanes-Estrada, Felipe J.
2008-01-01
We present an elementary method to obtain Green's functions in non-perturbative quantum field theory in Minkowski space from Green's functions calculated in Euclidean space. Since in non-perturbative field theory the analytical structure of amplitudes often is unknown, especially in the presence of confined fields, dispersive representations suffer from systematic uncertainties. Therefore, we suggest to use the Cauchy-Riemann equations, which perform the analytical continuation without assuming global information on the function in the entire complex plane, but only in the region through which the equations are solved. We use as example the quark propagator in Landau gauge quantum chromodynamics, which is known from lattice and Dyson-Schwinger studies in Euclidean space. The drawback of the method is the instability of the Cauchy-Riemann equations against high-frequency noise,which makes it difficult to achieve good accuracy. We also point out a few curious details related to the Wick rotation. (orig.)
Tsai, Wei-Chung; Lee, Kun-Tai; Wu, Ming-Tsang; Chu, Chih-Sheng; Lin, Tsung-Hsien; Hsu, Po-Chao; Su, Ho-Ming; Voon, Wen-Chol; Lai, Wen-Ter; Sheu, Sheng-Hsiung
2013-07-01
The 12-lead electrocardiogram (ECG) is a commonly used tool to access left atrial enlargement, which is a marker of left ventricular diastolic dysfunction (LVDD). The aim of this study was to evaluate any association of the P-wave measurements in ECG with left atrial volume (LAV) index and LVDD. This study enrolled 270 patients. In this study, 4 ECG P-wave parameters corrected by heart rate, that is, corrected P-wave maximum duration (PWdurMaxC), corrected P-wave dispersion (PWdisperC), corrected P-wave area (PWareaC) and corrected mean P-wave duration (meanPWdurC), were measured. LAV and left ventricular diastolic parameters were measured from echocardiography. LVDD was defined as a pseudonormal or restrictive mitral inflow pattern. The 4 P-wave parameters were significantly correlated with the LAV index after adjusting for age, sex, diabetes, hypertension, coronary artery disease, body mass index and diastolic blood pressure in multivariate analysis. The standardized β coefficients of PWdurMaxC, PWdisperC, meanPWdurC and PWareaC were 0.338, 0.298, 0.215 and 0.296, respectively. The 4 P-wave parameters were also significantly correlated with LVDD after multivariate logistic regression analysis. The odds ratios (95% confidence intervals) of PWdurMaxC, PWdisperC, meanPWdurC and PWareaC were 1.03 (1.01-1.04), 1.02 (1.04-1.04), 1.04 (1.02-1.07) and 1.01 (1.00-1.02), respectively. This study demonstrated that PWdurMaxC, PWdisperC, meanPWdurC and PWareaC were important determinants of the LAV index and LVDD. Therefore, screening patients by means of the 12-lead ECG may be helpful in identifying a high-risk group of increased LAV index and LVDD.
The Euclidean three-point function in loop and perturbative gravity
International Nuclear Information System (INIS)
Rovelli, Carlo; Zhang Mingyi
2011-01-01
We compute the leading order of the three-point function in loop quantum gravity, using the vertex expansion of the Euclidean version of the new spin foam dynamics, in the region of γ < 1. We find results consistent with Regge calculus in the limit γ → 0, j → ∞. We also compute the tree-level three-point function of perturbative quantum general relativity in position space and discuss the possibility of directly comparing the two results.
Wang, B.
2017-10-15
Cellular microstructures within natural materials enlighten and promote the development of novel materials and structures in the industrial and engineering fields. Characterization of the microstructures and mechanical properties of these natural materials can help to understand the morphology-related mechanical properties and guide the structural optimization in industrial design. Among these natural cellular materials, pomelo peels, having a foam-like hierarchical microstructure, represent an ideal model for developing materials with high energy absorption efficiency. In this work, by combining X-ray tomographic imaging technique and digital volume correlation (DVC), in-situ stepwise uniaxial compression tests were performed to quantify the internal morphological evolution and kinematic responses of pomelo peel samples during compression. Via these experiments, the varying microstructure features and thus diverse resistance to compression from endocarp to exocarp are examined, and the evolution of both bundles bending and large strain domain from endocarp to mesocarp are explored. Based on the experimental results, the microstructure-related mechanical properties of pomelo peels in response to compressive loading that demonstrates nearly linear morphology-mechanics relationship were revealed.
Directory of Open Access Journals (Sweden)
Jong Hyun Cha
2017-01-01
Full Text Available BackgroundThe purpose of this study was to assess the correlation between the 2-dimensional (2D extent of orbital defects and the 3-dimensional (3D volume of herniated orbital content in patients with an orbital wall fracture.MethodsThis retrospective study was based on the medical records and radiologic data of 60 patients from January 2014 to June 2016 for a unilateral isolated orbital wall fracture. They were classified into 2 groups depending on whether the fracture involved the inferior wall (group I, n=30 or the medial wall (group M, n=30. The 2D area of the orbital defect was calculated using the conventional formula. The 2D extent of the orbital defect and the 3D volume of herniated orbital content were measured with 3D image processing software. Statistical analysis was performed to evaluate the correlations between the 2D and 3D parameters.ResultsVarying degrees of positive correlation were found between the 2D extent of the orbital defects and the 3D herniated orbital volume in both groups (Pearson correlation coefficient, 0.568−0.788; R2=32.2%−62.1%.ConclusionsBoth the calculated and measured 2D extent of the orbital defects showed a positive correlation with the 3D herniated orbital volume in orbital wall fractures. However, a relatively large volume of herniation (>0.9 cm3 occurred not infrequently despite the presence of a small orbital defect (<1.9 cm2. Therefore, estimating the 3D volume of the herniated content in addition to the 2D orbital defect would be helpful for determining whether surgery is indicated and ensuring adequate surgical outcomes.
International Nuclear Information System (INIS)
Carillo, Viviana; Cozzarini, Cesare; Chietera, Andreina; Perna, Lucia; Gianolini, Stefano; Maggio, Angelo; Botti, Andrea; Rancati, Tiziana; Valdagni, Riccardo; Fiorino, Claudio
2012-01-01
The correlation between bladder dose–wall-histogram (DWH) and dose–volume-histogram (DVH), dose–surface-histogram (DSH), and DVH-5/10 was investigated in a group of 28 patients; bladder walls were drawn on T2-MRI. DVH showed the poorest correlation with DWH; DSH or DVH-5/10 should be preferred in planning; absolute DVH may be used for radical patients, although less robust.
Yilmaz, Adem; Musluman, Ahmet Murat; Kanat, Ayhan; Cavusoglu, Halit; Terzi, Yuksel; Aydin, Yunus
2011-01-01
The correlation between hematoma volume and outcome in ruptured arteriovenous malformations (AVM) with accompanying posterior fossa hematoma was retrospectively evaluated. Microsurgery operations were performed on 127 patients with intracranial AVM between January 1998 and January 2009 at our clinic. Fifteen (11.8%) patients were identified as suffering from posterior fossa AVM, and twelve of these patients presented with a cerebellar hematoma. All patients were clinically evaluated according to the following criteria: modified Rankin Scale (mRS) prior to surgery, Spetzler-Martin grade (SMG) of the AVMs, hematoma volume prior to surgery, and mRS following surgery. Postoperative mRS scores were significantly lower than preoperative scores (p=0.0001). Postoperative outcomes were concordant with the SMG of the AVMs (r=0.67, p=0.033), hematoma volume (r=0.537, p=0.072) and preoperative mRS scores (r=0.764, p=0.004). These analyses show that the postoperative mRS score is strongly correlated with a preoperative mRS score, hematoma volume and SMG. Posterior fossa AVMs present an increased risk for hemorrhage and for increased morbidity and mortality. Cases with hematoma should be operated on an urgent basis. We conclude that hematoma volume is a factor that impacts postoperative results and prognosis. SMG and preoperative mRS scores were also correlated with outcome.
Posthuma, D.; Baare, W.F.C.; Hulshoff Pol, H.E.; Kahn, R.S.; Boomsma, D.I.; de Geus, E.J.C.
2003-01-01
We recently showed that the correlation of gray and white matter volume with full scale IQ and the Working Memory dimension are completely mediated by common genetic factors (Posthuma et al., 2002). Here we examine whether the other WAIS III dimensions (Verbal Comprehension, Perceptual Organization,
Wang, B; Pan, B; Tao, Ran; Lubineau, Gilles
2017-01-01
The use of digital volume correlation (DVC) in combination with a laboratory x-ray computed tomography (CT) for full-field internal 3D deformation measurement of opaque materials has flourished in recent years. During x-ray tomographic imaging
J.L.H.R. Bosch (Ruud); W.C.J. Hop (Wim); C.H. Bangma (Chris); W.J. Kirkels (Wim); F.H. Schröder (Fritz)
1995-01-01
textabstractThe correlation between both prostate specific antigen levels (PSA) and prostate specific antigen density (PSAD) and age, prostate volume parameters, body mass index, and the International Prostate Symptom Score (IPSS) were studied in a community‐based population. A sample of 502 men
International Nuclear Information System (INIS)
Dasgupta, I.
1998-01-01
We discuss new bounce-like (but non-time-reversal-invariant) solutions to Euclidean equations of motion, which we dub boomerons. In the Euclidean path integral approach to quantum theories, boomerons make an imaginary contribution to the vacuum energy. The fake vacuum instability can be removed by cancelling boomeron contributions against contributions from time reversed boomerons (anti-boomerons). The cancellation rests on a sign choice whose significance is not completely understood in the path integral method. (orig.)
International Nuclear Information System (INIS)
Deenadayalu, N.; Sen, S.; Sibiya, P.N.
2009-01-01
The experimental densities for the binary systems of an ionic liquid and an alkanol {1-ethyl-3-methylimidazolium ethylsulfate [EMIM] + [EtSO 4 ] - + methanol or 1-propanol or 2-propanol} were determined at T = (298.15, 303.15, and 313.15) K. The excess molar volumes for the above systems were then calculated from the experimental density values for each temperature. The Redlich-Kister smoothing polynomial was used to fit the experimental results and the partial molar volumes were determined from the Redlich-Kister coefficients. For all the systems studied, the excess molar volume results were negative over the entire composition range for all the temperatures. The excess molar volumes were correlated with the pentic four parameter virial (PFV) equation of state (EoS) model
International Nuclear Information System (INIS)
Goto, Masami; Abe, Osamu; Takao, Hidemasa; Inano, Sachiko; Mori, Harushi; Kunimatsu, Akira; Ohtomo, Kuni; Miyati, Tosiaki; Yoshikawa, Takeharu; Hayashi, Naoto; Kabasawa, Hiroyuki; Aoki, Shigeki; Ino, Kenji; Iida, Kyouhito; Yano, Keiichi
2011-01-01
Previous studies revealed a correlation between local brain volume and cognitive function. The aim of the present study was to investigate the correlation between local gray matter volume and the Wechsler Memory Scale-Revised (WMS-R) logical/verbal memory (WMS-R-verbal) score in healthy adults using a 3 Tesla magnetic resonance scanner and voxel-based morphometry (VBM). T1-weighted magnetic resonance images were obtained in 1,169 healthy adults. The T1-weighted images in native space were bias-corrected, spatially normalized, and segmented into gray matter, white matter, and cerebrospinal fluid images with Statistical Parametric Mapping 5. To investigate regionally the specific effects of the WMS-R-verbal score on the gray matter images, simple regression analysis was performed by VBM treating age, total intracranial volume, and gender as confounding covariates. A P value of less than 0.05 corrected with false discovery rate in voxel difference was considered to be statistically significant. Our study showed a significant positive correlation between the WMS-R-verbal score and the bilateral entorhinal cortex volume. In the right entorhinal, T value is 4.75, and the size of the clusters is 155 voxels. In the left entorhinal, T value is 4.08, and the size of the clusters is 23 voxels. A significant negative correlation was not found. To our knowledge, this is the first VBM study showing that entorhinal cortex volume is positively correlated with the WMS-R-verbal score for healthy subjects. Therefore, in our structural neuroimaging study, we add evidence to the hypothesis that the entorhinal cortex is involved in verbal memory processing. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Goto, Masami [University of Tokyo Hospital, Department of Radiological Technology, Graduate School of Medicine, Tokyo (Japan); Kanazawa University, Tsunomatyou, Graduate School of Medical Science, Kanazawa (Japan); Abe, Osamu; Takao, Hidemasa; Inano, Sachiko; Mori, Harushi; Kunimatsu, Akira; Ohtomo, Kuni [University of Tokyo Hospital, Department of Radiology, Tokyo (Japan); Miyati, Tosiaki [Kanazawa University, Tsunomatyou, Graduate School of Medical Science, Kanazawa (Japan); Yoshikawa, Takeharu; Hayashi, Naoto [University of Tokyo Hospital, Department of Computational Diagnostic Radiology and Preventive Medicine, Tokyo (Japan); Kabasawa, Hiroyuki [GE Healthcare, Japan Applied Science Laboratory, Hino (Japan); Aoki, Shigeki [Juntendo University, Department of Radiology, Tokyo (Japan); Ino, Kenji; Iida, Kyouhito; Yano, Keiichi [University of Tokyo Hospital, Department of Radiological Technology, Graduate School of Medicine, Tokyo (Japan)
2011-08-15
Previous studies revealed a correlation between local brain volume and cognitive function. The aim of the present study was to investigate the correlation between local gray matter volume and the Wechsler Memory Scale-Revised (WMS-R) logical/verbal memory (WMS-R-verbal) score in healthy adults using a 3 Tesla magnetic resonance scanner and voxel-based morphometry (VBM). T1-weighted magnetic resonance images were obtained in 1,169 healthy adults. The T1-weighted images in native space were bias-corrected, spatially normalized, and segmented into gray matter, white matter, and cerebrospinal fluid images with Statistical Parametric Mapping 5. To investigate regionally the specific effects of the WMS-R-verbal score on the gray matter images, simple regression analysis was performed by VBM treating age, total intracranial volume, and gender as confounding covariates. A P value of less than 0.05 corrected with false discovery rate in voxel difference was considered to be statistically significant. Our study showed a significant positive correlation between the WMS-R-verbal score and the bilateral entorhinal cortex volume. In the right entorhinal, T value is 4.75, and the size of the clusters is 155 voxels. In the left entorhinal, T value is 4.08, and the size of the clusters is 23 voxels. A significant negative correlation was not found. To our knowledge, this is the first VBM study showing that entorhinal cortex volume is positively correlated with the WMS-R-verbal score for healthy subjects. Therefore, in our structural neuroimaging study, we add evidence to the hypothesis that the entorhinal cortex is involved in verbal memory processing. (orig.)
Furlanis, Giovanni; Ajčević, Miloš; Stragapede, Lara; Lugnan, Carlo; Ridolfi, Mariana; Caruso, Paola; Naccarato, Marcello; Ukmar, Maja; Manganotti, Paolo
2018-04-30
The National Institutes of Health Stroke Scale (NIHSS) is the most adopted stroke patients' evaluation tool in emergency settings to assess the severity of stroke and to determine the patients' eligibility for specific treatments. Computed tomography perfusion (CTP) is crucial to identify salvageable tissue that can benefit from the reperfusion treatment. The aim of this study is to identify the relation between the NIHSS scores and the hypoperfused volumes evaluated by CTP in patients with hyperacute ischemic stroke. This retrospective study was conducted on 105 patients with ischemic stroke who underwent NIHSS assessment and CTP in the hyperacute phase. Hypoperfused volume was evaluated by CTP maps processed with semi-automatic algorithm. An analysis was conducted to determine the degree of correlation between the NIHSS scores and the ischemic lesion volumes and to investigate the relation between the anterior and the posterior circulation strokes, as well as between the right and the left hemispheric strokes. A significant correlation was found between ischemic volume and NIHSS score at baseline (r = .82; P correlation was identified in the anterior circulation stroke (r = .76; P correlated for the left and the right hemispheric strokes (r = .83 and .81; P correlation between the baseline NIHSS score and the ischemic volume estimated by CTP. We confirmed that NIHSS is a reliable predictor of perfusion deficits in acute ischemic stroke. CTP allows fast imaging assessment in the hyperacute phase. The results highlight the importance of these diagnostic tools in the assessment of stroke severity and in acute decision-making. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.
Directory of Open Access Journals (Sweden)
Vadayath Usha Menon
2011-01-01
Full Text Available Background: Thyroid disorders are more commonly seen among females and the prevalence increases with age. There is no population data from India focusing on iodine levels and their correlations with thyroid volume and other factors in adult women. Aim: This study was designed to establish the iodine status and its relation with various factors including thyroid volume measured by ultrasound among the females of Kerala. Materials and Methods: This was a cross sectional house to house survey among the females above 35 years of age in a randomly selected urban area in Cochin Corporation, Kerala State, India. Selected subjects were interviewed, examined and blood and urine tests were done. Thyroid volume was calculated using ultrasound. Results: Among the 508 subjects who participated in the checkup, 471 subjects were included for analysis. Mean age was 50.3 + 10.7 years and 53.2% were postmenopausal. A total of 98% of the subjects were using iodized salt and median urinary iodine excretion (UIE was 162.6 mcg/l. UIE had negative correlation with age and systolic blood pressure (BP, but had no correlation with thyroid volume (TV, thyroid nodularity, free thyroxine 4 (FT4, thyroid stimulating hormone (TSH or anti thyroid peroxidase (TPO levels. Iodine deficiency was more commonly seen in subjects with hypertension and also among postmenopausal females. Conclusions: This study showed that females > 35 years were iodine sufficient, though one third of the subjects had UIE levels less than the recommended level. Iodine levels had significant negative correlation with age and systolic BP and no correlation with thyroid volume or biochemical parameters. Iodine deficiency was significantly higher in subjects with new and known hypertension and this relation merits further evaluation.
Energy Technology Data Exchange (ETDEWEB)
Gong, Nan-Jie [Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong (China); Wong, Chun-Sing, E-mail: drcswong@gmail.com [Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong (China); Chu, Yiu-Ching [Department of Radiology, Kwong Wah Hospital, Hong Kong (China); Guo, Hua [Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing (China); Huang, Bingsheng [Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong (China); Chan, Queenie [Philips Healthcare, Hong Kong (China)
2013-10-01
Purpose: To improve the accuracy of volume and apparent diffusion coefficient (ADC) measurements in diffusion-weighted magnetic resonance imaging (MRI), we proposed a method based on thresholding both the b0 images and the ADC maps. Methods and Materials: In 21 heterogeneous lesions from patients with metastatic gastrointestinal stromal tumors (GIST), gross lesion were manually contoured, and corresponding volumes and ADCs were denoted as gross tumor volume (GTV) and gross ADC (ADC{sub g}), respectively. Using a k-means clustering algorithm, the probable high-cellularity tumor tissues were selected based on b0 images and ADC maps. ADC and volume of the tissues selected using the proposed method were denoted as thresholded ADC (ADC{sub thr}) and high-cellularity tumor volume (HCTV), respectively. The metabolic tumor volume (MTV) in positron emission tomography (PET)/computed tomography (CT) was measured using 40% maximum standard uptake value (SUV{sub max}) as the lower threshold, and corresponding mean SUV (SUV{sub mean}) was also measured. Results: HCTV had excellent concordance with MTV according to Pearson's correlation (r=0.984, P<.001) and linear regression (slope = 1.085, intercept = −4.731). In contrast, GTV overestimated the volume and differed significantly from MTV (P=.005). ADC{sub thr} correlated significantly and strongly with SUV{sub mean} (r=−0.807, P<.001) and SUV{sub max} (r=−0.843, P<.001); both were stronger than those of ADC{sub g}. Conclusions: The proposed lesion-adaptive semiautomatic method can help segment high-cellularity tissues that match hypermetabolic tissues in PET/CT and enables more accurate volume and ADC delineation on diffusion-weighted MR images of GIST.
Le Cann, Sophie; Tudisco, Erika; Perdikouri, Christina; Belfrage, Ola; Kaestner, Anders; Hall, Stephen; Tägil, Magnus; Isaksson, Hanna
2017-11-01
Metallic implants are commonly used as surgical treatments for many orthopedic conditions. The long-term stability of implants relies on an adequate integration with the surrounding bone. Unsuccessful integration could lead to implant loosening. By combining mechanical loading with high-resolution 3D imaging methods, followed by image analysis such as Digital Volume Correlation (DVC), we aim at evaluating ex vivo the mechanical resistance of newly formed bone at the interface. X-rays tomography is commonly used to image bone but induces artefacts close to metallic components. Utilizing a different interaction with matter, neutron tomography is a promising alternative but has not yet been used in studies of bone mechanics. This work demonstrates that neutron tomography during in situ loading is a feasible tool to characterize the mechanical response of bone-implant interfaces, especially when combined with DVC. Experiments were performed where metal screws were implanted in rat tibiae during 4 weeks. The screws were pulled-out while the samples were sequentially imaged in situ with neutron tomography. The images were analyzed to quantify bone ingrowth around the implants. DVC was used to track the internal displacements and calculate the strain fields in the bone during loading. The neutron images were free of metal-related artefacts, which enabled accurate quantification of bone ingrowth on the screw (ranging from 60% to 71%). DVC allowed successful identification of the deformation and cracks that occurred during mechanical loading and led to final failure of the bone-implant interface. Copyright © 2017 Elsevier Ltd. All rights reserved.
Moussawi, Ali
2014-10-01
In this study, we present an original approach to assess structural changes during bread crumb compression using a mechanical testing bench coupled to 3D X-ray microtomography. X-ray images taken at different levels of compression of the bread crumb are processed using image analysis. A subset-based digital volume correlation method is used to achieve the 3D displacement field. Within the limit of the approach, deterministic search strategy is implemented for solving subset displacement in each deformed image with regards to the undeformed one. The predicted displacement field in the transverse directions shows differences that depend on local cell arrangement as confirmed by finite element analysis. The displacement component in the loading direction is affected by the magnitude of imposed displacement and shows more regular change. Large displacement levels in the compression direction are in good agreement with the imposed experimental displacement. The results presented here are promising in a sense of possible identification of local foam properties. New insights are expected to achieve better understanding of structural heterogeneities in the overall perception of the product. Industrial relevance: Texture evaluation of cereal product is an important aspect for testing consumer acceptability of new designed products. Mechanical evaluation of backed products is a systemic route for determining texture of cereal based product. From the industrial viewpoint, mechanical evaluation allows saving both time and cost compared to panel evaluation. We demonstrate that better understanding of structural changes during texture evaluation can be achieved in addition to texture evaluation. Sensing structural changes during bread crumb compression is achievable by combining novel imaging technique and processing based on image analysis. We present thus an efficient way to predict displacements during compression of freshly baked product. This method can be used in different
Pasha, Sharif M; Klok, Frederikus A; van der Bijl, Noortje; de Roos, Albert; Kroft, Lucia J M; Huisman, Menno V
2012-08-01
N-terminal pro-Brain Natriuretic Peptide (NT-pro-BNP) is primarily secreted by left ventricular (LV) stretch and wall tension. Notably, NT-pro-BNP is a prognostic marker in acute pulmonary embolism (PE), which primarily stresses the right ventricle (RV). We sought to evaluate the relative contribution of the RV to NT-pro-BNP levels during PE. A post-hoc analysis of an observational prospective outcome study in 113 consecutive patients with computed tomography (CT)-proven PE and 226 patients in whom PE was clinically suspected but ruled out by CT. In all patients RV and LV function was established by assessing ECG-triggered-CT measured ventricular end-diastolic-volumes and ejection fraction (EF). NT-pro-BNP was assessed in all patients. The correlation between RV and LV end-diastolic-volumes and systolic function was evaluated by multiple linear regression corrected for known confounders. In the PE cohort increased RVEF (β-coefficient (95% confidence interval [CI]) -0.044 (± -0.011); p<0.001) and higher RV end-diastolic-volume (β-coefficient 0.005 (± 0.001); p<0.001) were significantly correlated to NT-pro-BNP, while no correlation was found with LVEF (β-coefficient 0.005 (± 0.010); p=0.587) and LV end-diastolic-volume (β-coefficient -0.003 (± 0.002); p=0.074). In control patients without PE we found a strong correlation between NT-pro-BNP levels and LVEF (β-coefficient -0.027 (± -0.006); p<0.001) although not LV end-diastolic-volume (β-coefficient 0.001 (± 0.001); p=0.418). RVEF (β-coefficient -0.002 (± -0.006); p=0.802) and RV end-diastolic-volume (β-coefficient <0.001 (± 0.001); p=0.730) were not correlated in patients without PE. In PE patients, lower RVEF and higher RV end-diastolic-volume were significantly correlated to NT-pro-BNP levels as compared to control patients without PE. These observations provide pathophysiological ground for the well-known prognostic value of NT-pro-BNP in acute PE.
International Nuclear Information System (INIS)
Bamford, David
2002-01-01
The work described in this thesis is concerned with the study of the local free volume measured by Positron Annihilation Spectroscopy and its correlation with the physical, chemical and structural properties of polymers. The average size of the local free volume holes in branched poly(ethylene-co-olefin) and poly(propylene-co-olefin) copolymers is studied using Positron Annihilation Lifetime Spectroscopy PALS and correlated with the number and length of the branches and the physical properties determined from Differential Scanning Calorimetry DSC and density measurements. The presence of the n-alkyl branches were found to form sterical hindrances to an effective chain packing resulting in a linear increase in the average free volume hole sizes, an increase in the specific volume of the amorphous phase, a decrease in the sample crystallinity and a decrease in the glass transition and melting temperatures. A linear relation was found between the average size of the free volume holes and the glass transition temperature, allowing a method for estimating the glass transition temperature of a sample purely from room temperature PALS measurements. Evidence is presented to support the common assumption that the fractional free volume is directly proportional to the average free volume hole size and that the specific crystalline volume may accurately represent the value of the specific occupied volume. The number density of holes was found to be constant for each of the series of copolymers in agreement with the above findings. Poly((ethylene glycol) 23 dimethacrylate) and poly(ethylene oxide) based polymer electrolytes exhibiting single anion, single cation and mixed ion conduction are studied as a function of temperature using PALS, ionic conductivity and DSC measurements. The glass transition temperature, the thermal expansion of the free volume and the effects on the free volume due to the addition of the ions are discussed. In particular, an explanation for the
Taki, Yasuyuki; Hashizume, Hiroshi; Thyreau, Benjamin; Sassa, Yuko; Takeuchi, Hikaru; Wu, Kai; Kotozaki, Yuka; Nouchi, Rui; Asano, Michiko; Asano, Kohei; Fukuda, Hiroshi; Kawashima, Ryuta
2013-08-01
We examined linear and curvilinear correlations of gray matter volume and density in cortical and subcortical gray matter with age using magnetic resonance images (MRI) in a large number of healthy children. We applied voxel-based morphometry (VBM) and region-of-interest (ROI) analyses with the Akaike information criterion (AIC), which was used to determine the best-fit model by selecting which predictor terms should be included. We collected data on brain structural MRI in 291 healthy children aged 5-18 years. Structural MRI data were segmented and normalized using a custom template by applying the diffeomorphic anatomical registration using exponentiated lie algebra (DARTEL) procedure. Next, we analyzed the correlations of gray matter volume and density with age in VBM with AIC by estimating linear, quadratic, and cubic polynomial functions. Several regions such as the prefrontal cortex, the precentral gyrus, and cerebellum showed significant linear or curvilinear correlations between gray matter volume and age on an increasing trajectory, and between gray matter density and age on a decreasing trajectory in VBM and ROI analyses with AIC. Because the trajectory of gray matter volume and density with age suggests the progress of brain maturation, our results may contribute to clarifying brain maturation in healthy children from the viewpoint of brain structure. Copyright © 2012 Wiley Periodicals, Inc.
Kloth, C; Thaiss, W M; Hetzel, J; Ditt, H; Grosse, U; Nikolaou, K; Horger, M
2016-07-01
To assess the impact of endobronchial coiling on the segment bronchus cross-sectional area and volumes in patients with lung emphysema using quantitative chest-CT measurements. Thirty patients (female = 15; median age = 65.36 years) received chest-CT before and after endobronchial coiling for lung volume reduction (LVR) between January 2010 and December 2014. Thin-slice (0.6 mm) non-enhanced image data sets were acquired both at end-inspiration and end-expiration using helical technique and 120 kV/100-150 mAs. Clinical response was defined as an increase in the walking distance (Six-minute walk test; 6MWT) after LVR-therapy. Additionally, pulmonary function test (PFT) measurements were used for clinical correlation. In the treated segmental bronchia, the cross-sectional lumen area showed significant reduction (p 0.05). In the ipsilateral lobes, the lumina showed no significant changes. In the contralateral lung, we found tendency towards increased cross-sectional area in inspiration (p = 0.06). Volumes of the treated segments correlated with the treated segmental bronchial lumina in expiration (r = 0.80, p volume of the treated lobe in responders only. Endobronchial coiling causes significant decrease in the cross-sectional area of treated segment bronchi in inspiration and a slight increase in expiration accompanied by a volume reduction. • Endobronchial coiling has indirect impact on cross-sectional area of treated segment bronchi • Volume changes of treated lobes correlate with changes in bronchial cross-sectional area • Coil-induced effects reflect their stabilizing and stiffening impact on lung parenchyma • Endobronchial coiling reduces bronchial collapsing compensating the loss of elasticity.
International Nuclear Information System (INIS)
Adachi, Michito; Sato, Takamichi; Kawakatsu, Shinobu; Ohshima, Fumi
2012-01-01
The aim of this study was to investigate whether the outline of the hippocampal body becomes rounded on coronal magnetic resonance imaging (MRI) as the volume of the hippocampal formation decreases in Alzheimer's disease (AD). Institutional review board approval of the study protocol was obtained, and all subjects provided informed consent for the mini-mental state examination (MMSE) and MRI. The MRI and MMSE were prospectively performed in all 103 subjects (27 men and 76 women; mean age ± standard deviation, 77.7 ± 7.8 years) who had AD or were concerned about having of dementia and who consulted our institute over 1 year. The subjects included 14 non-dementia cases (MMSE score ≥ 28) and 89 AD cases (MMSE score ≤ 27). The total volume of the bilateral hippocampal formation (VHF) was assessed with a tracing method, and the ratio of the VHF to the intracranial volume (RVHF) and the rounding ratio (RR) of the hippocampal body (mean ratio of its short dimension to the long dimension in the bilateral hippocampal body) were calculated. Using Spearman's correlation coefficient, the correlations between RR and VHF and between RR and RVHF were assessed. Correlation coefficients between RR and VHF and between RR and RVHF were -0.419 (p < 0.01) and -0.418 (p < 0.01), respectively. There was a significant negative correlation between RR and the volume of the hippocampal formation. The outline of the body of the hippocampal formation becomes rounded on coronal images as its volume decreases in AD. (orig.)
Supersymmetry on a euclidean spacetime lattice 1. A target theory with four supercharges
International Nuclear Information System (INIS)
Cohen, Andrew G.; Kaplan, David B.; Katz, Emanuel; Uensal, Mithat
2003-01-01
We formulate a euclidean spacetime lattice whose continuum limit is (2,2) supersymmetric Yang-Mills theory in two dimensions, a theory which possesses four supercharges and an anomalous global chiral symmetry. The lattice action respects one exact supersymmetry, which allows the target theory to emerge in the continuum limit without fine-tuning. Our method exploits an orbifold construction described previously for spatial lattices in Minkowski space, and can be generalized to more complicated theories with additional supersymmetry and more spacetime dimensions. (author)
Steiner tree heuristic in the Euclidean d-space using bottleneck distances
DEFF Research Database (Denmark)
Lorenzen, Stephan Sloth; Winter, Pawel
2016-01-01
Some of the most efficient heuristics for the Euclidean Steiner minimal tree problem in the d-dimensional space, d ≥2, use Delaunay tessellations and minimum spanning trees to determine small subsets of geometrically close terminals. Their low-cost Steiner trees are determined and concatenated...... in a greedy fashion to obtain a low cost tree spanning all terminals. The weakness of this approach is that obtained solutions are topologically related to minimum spanning trees. To avoid this and to obtain even better solutions, bottleneck distances are utilized to determine good subsets of terminals...
The stochastic versus the Euclidean approach to quantum fields on a static space-time
International Nuclear Information System (INIS)
De Angelis, G.F.; de Falco, D.
1986-01-01
Equations are presented which modify the definition of the Gaussian field in the Rindler chart in order to make contact with the Wightman state, the Hartle-Hawking state, and the Euclidean field. By taking Ornstein-Uhlenbeck processes the authors have chosen, in the sense of stochastic mechanics, to place precisely the Fulling modes in their harmonic oscillator ground state. In this respect, together with the periodicity of Minkowski space-time, the authors observe that the covariance of the Ornstein-Uhlenbeck process can be obtained by analytical continuation of the Wightman function of the harmonic oscillator at zero temperature
Constant curvature black holes in Einstein AdS gravity: Euclidean action and thermodynamics
Guilleminot, Pablo; Olea, Rodrigo; Petrov, Alexander N.
2018-03-01
We compute the Euclidean action for constant curvature black holes (CCBHs), as an attempt to associate thermodynamic quantities to these solutions of Einstein anti-de Sitter (AdS) gravity. CCBHs are gravitational configurations obtained by identifications along isometries of a D -dimensional globally AdS space, such that the Riemann tensor remains constant. Here, these solutions are interpreted as extended objects, which contain a (D -2 )-dimensional de-Sitter brane as a subspace. Nevertheless, the computation of the free energy for these solutions shows that they do not obey standard thermodynamic relations.
DEFF Research Database (Denmark)
Meng, Weizhi; Li, Wenjuan; Wang, Yu
2017-01-01
and healthcare personnel. The underlying network architecture to support such devices is also referred to as medical smartphone networks (MSNs). Similar to other networks, MSNs also suffer from various attacks like insider attacks (e.g., leakage of sensitive patient information by a malicious insider......). In this work, we focus on MSNs and design a trust-based intrusion detection approach through Euclidean distance-based behavioral profiling to detect malicious devices (or called nodes). In the evaluation, we collaborate with healthcare organizations and implement our approach in a real simulated MSN...
Exact Boson-Fermion Duality on a 3D Euclidean Lattice
Chen, Jing-Yuan; Son, Jun Ho; Wang, Chao; Raghu, S.
2018-01-01
The idea of statistical transmutation plays a crucial role in descriptions of the fractional quantum Hall effect. However, a recently conjectured duality between a critical boson and a massless two-component Dirac fermion extends this notion to gapless systems. This duality sheds light on highly nontrivial problems such as the half-filled Landau level, the superconductor-insulator transition, and surface states of strongly coupled topological insulators. Although this boson-fermion duality has undergone many consistency checks, it has remained unproven. We describe the duality in a nonperturbative fashion using an exact UV mapping of partition functions on a 3D Euclidean lattice.
Green's functions in Bianchi type-I spaces. Relation between Minkowski and Euclidean approaches
International Nuclear Information System (INIS)
Bukhbinder, I.L.; Kirillova, E.N.
1988-01-01
A theory is considered for a free scalar field with a conformal connection in a curved space-time with a Bianchi type-I metric. A representation is obtained for the Green's function G∼ in in in the form of an integral of a Schwinger-DeWitt kernel along a contour in a plane of complex-valued proper time. It is shown how as transition may be accomplished from Green's functions in space with the Euclidean signature to Green's functions in space with Minkowski signature and vice versa
McBeck, J.; Kobchenko, M.; Hall, S.; Tudisco, E.; Cordonnier, B.; Renard, F.
2017-12-01
Previous studies have identified compaction bands primarily within sandstones, and in fewer instances, within other porous rocks and sediments. Using Digital Volume Correlation (DVC) of X-ray microtomography scans, we find evidence of localized zones of high axial contraction that form tabular structures sub-perpendicular to maximum compression, σ1, in Green River shale. To capture in situ strain localization throughout loading, two shale cores were deformed in the HADES triaxial deformation apparatus installed on the X-ray microtomography beamline ID19 at the European Synchrotron Radiation Facility. In these experiments, we increase σ1 in increments of two MPa, with constant confining pressure (20 MPa), until the sample fails in macroscopic shear. After each stress step, a 3D image of the sample inside the rig is acquired at a voxel resolution of 6.5 μm. The evolution of lower density regions within 3D reconstructions of linear attenuation coefficients reveal the development of fractures that fail with some opening. If a fracture produces negligible dilation, it may remain undetected in image segmentation of the reconstructions. We use the DVC software TomoWarp2 to identify undetected fractures and capture the 3D incremental displacement field between each successive pair of microtomography scans acquired in each experiment. The corresponding strain fields reveal localized bands of high axial contraction that host minimal shear strain, and thus match the kinematic definition of compaction bands. The bands develop sub-perpendicular to σ1 in the two samples in which pre-existing bedding laminations were oriented parallel and perpendicular to σ1. As the shales deform plastically toward macroscopic shear failure, the number of bands and axial contraction within the bands increase, while the spacing between the bands decreases. Compaction band development accelerates the rate of overall axial contraction, increasing the mean axial contraction throughout the sample
International Nuclear Information System (INIS)
Veres, C; Garsi, J P; Rubino, C; De Vathaire, F; Diallo, I; Pouzoulet, F; Bidault, F; Chavaudra, J; Bridier, A; Ricard, M; Ferreira, I; Lefkopoulos, D
2010-01-01
The aim of this study is to define criteria for accurate representation of the thyroid in human models used to represent external beam radiotherapy (EBRT) patients and evaluate the relationship between the volume of this organ and clinical and anthropometric characteristics. From CT images, we segmented the thyroid gland and calculated its volume for a population of 188 EBRT patients of both sexes, with ages ranging from 1 to 89 years. To evaluate uncertainties linked to measured volumes, experimental studies on the Livermore anthropomorphic phantom were performed. For our population of EBRT patients, we observed that in children, thyroid volume increased rapidly with age, from about 3 cm 3 at 2 years to about 16 cm 3 at 20. In adults, the mean thyroid gland volume was 23.5 ± 9 cm 3 for males and 17.5 ± 8 cm 3 for females. According to anthropometric parameters, the best fit for children was obtained by modeling the log of thyroid volume as a linear function of body surface area (BSA) (p < 0.0001) and age (p = 0.04) and for adults, as a linear function of BSA (p < 0.0001) and gender (p = 0.01). This work enabled us to demonstrate that BSA was the best indicator of thyroid volume for both males and females. These results should be taken into account when modeling the volume of the thyroid in human models used to represent EBRT patients for dosimetry in retrospective studies of the relationship between the estimated dose to the thyroid and long-term follow-up data on EBRT patients. (note)
Hegedűs, Árpád
2018-03-01
In this paper, using the light-cone lattice regularization, we compute the finite volume expectation values of the composite operator \\overline{Ψ}Ψ between pure fermion states in the Massive Thirring Model. In the light-cone regularized picture, this expectation value is related to 2-point functions of lattice spin operators being located at neighboring sites of the lattice. The operator \\overline{Ψ}Ψ is proportional to the trace of the stress-energy tensor. This is why the continuum finite volume expectation values can be computed also from the set of non-linear integral equations (NLIE) governing the finite volume spectrum of the theory. Our results for the expectation values coming from the computation of lattice correlators agree with those of the NLIE computations. Previous conjectures for the LeClair-Mussardo-type series representation of the expectation values are also checked.
Ojha, Prasanta K.; Rath, Sangram K.; Sharma, Sandeep K.; Sudarshan, Kathi; Pujari, Pradeep K.; Chongdar, Tapas K.; Gokhale, Nitin M.
2015-01-01
The role of La+3/Sr+2 ratios, which is varied from 0.08 to 5.09, on density, molar volume, packing fraction, free volume, thermal and electrical properties in strontium lanthanum aluminoborosilicate based glass sealants intended for solid oxide fuel cell (SOFC) applications is evaluated. The studies reveal expansion of the glass network evident from increasing molar volume and decreasing packing fraction of glasses with progressive La+3 substitutions. The molecular origin of these macroscopic structural features can be accounted for by the free volume parameters measured from positron annihilation lifetime spectroscopy (PALS). The La+3 induced expanded glass networks show increased number of subnanoscopic voids with larger sizes, as revealed from the ortho-positronium (o-Ps) lifetime and its intensity. A remarkably direct correspondence between the molar volume and fractional free volume trend is established with progressive La2O3 substitution in the glasses. The effect of these structural changes on the glass transition temperature, softening temperature, coefficient of thermal expansion, thermal stability as well as electrical conductivity has been studied.
International Nuclear Information System (INIS)
Terk, M.R.; Dardashti, S.; Liebman, H.A.
2000-01-01
Purpose. To determine whether T1-weighted magnetic resonance (MR) images can demonstrate response in the marrow of patients with type 1 Gaucher disease treated with enzyme replacement therapy (ERT) and to determine whether a relationship exists between liver and spleen volume reductions and visible marrow changes.Patients. Forty-two patients with type 1 Gaucher disease were evaluated on at least two occasions. Thirty-two patients received ERT. Of these patients, 15 had a baseline examination prior to the initiation of ERT. The remaining 10 patients did not receive ERT.Design. T1-weighted and gradient recalled echo (GRE) coronal images of the femurs and hips were obtained. Concurrently, liver and spleen volumes were determined using contiguous breath-hold axial gradient-echo images. T1-weighted images of the hips and femurs were evaluated to determine change or lack of change in the yellow marrow.Results. Of the 32 patients receiving ERT, 14 (44%) demonstrated increased signal on T1-weighted images suggesting an increase in the amount of yellow marrow. If only the 15 patients with a baseline examination were considered, the response rate to ERT was 67%. Using Student's t-test a highly significant correlation (P<0.005) was found between marrow response and reduction in liver and spleen volume.Conclusions. Marrow changes in patients receiving ERT can be detected by T1-weighted images. This response correlated with reductions in visceral volumes (P<0.0005). (orig.)
Hu, Weiming; Li, Xi; Luo, Wenhan; Zhang, Xiaoqin; Maybank, Stephen; Zhang, Zhongfei
2012-12-01
Object appearance modeling is crucial for tracking objects, especially in videos captured by nonstationary cameras and for reasoning about occlusions between multiple moving objects. Based on the log-euclidean Riemannian metric on symmetric positive definite matrices, we propose an incremental log-euclidean Riemannian subspace learning algorithm in which covariance matrices of image features are mapped into a vector space with the log-euclidean Riemannian metric. Based on the subspace learning algorithm, we develop a log-euclidean block-division appearance model which captures both the global and local spatial layout information about object appearances. Single object tracking and multi-object tracking with occlusion reasoning are then achieved by particle filtering-based Bayesian state inference. During tracking, incremental updating of the log-euclidean block-division appearance model captures changes in object appearance. For multi-object tracking, the appearance models of the objects can be updated even in the presence of occlusions. Experimental results demonstrate that the proposed tracking algorithm obtains more accurate results than six state-of-the-art tracking algorithms.
Energy Technology Data Exchange (ETDEWEB)
Goettler, Jens; Preibisch, Christine [TU Muenchen, Department of Neuroradiology, Klinikum rechts der Isar, Munich (Germany); TU Muenchen, TUM Neuroimaging Center (TUM-NIC), Klinikum rechts der Isar, Munich (Germany); Lukas, Mathias; Mustafa, Mona; Schwaiger, Markus; Pyka, Thomas [TU Muenchen, Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany); Kluge, Anne; Kaczmarz, Stephan; Zimmer, Claus [TU Muenchen, Department of Neuroradiology, Klinikum rechts der Isar, Munich (Germany); Gempt, Jens; Ringel, Florian; Meyer, Bernhard [TU Muenchen, Department of Neurosurgery, Klinikum rechts der Isar, Munich (Germany); Foerster, Stefan [TU Muenchen, TUM Neuroimaging Center (TUM-NIC), Klinikum rechts der Isar, Munich (Germany); TU Muenchen, Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany); Klinikum Bayreuth, Department of Nuclear Medicine, Bayreuth (Germany)
2017-03-15
{sup 18}F-fluorethyltyrosine-(FET)-PET and MRI-based relative cerebral blood volume (rCBV) have both been used to characterize gliomas. Recently, inter-individual correlations between peak static FET-uptake and rCBV have been reported. Herein, we assess the local intra-lesional relation between FET-PET parameters and rCBV. Thirty untreated glioma patients (27 high-grade) underwent simultaneous PET/MRI on a 3 T hybrid scanner obtaining structural and dynamic susceptibility contrast sequences. Static FET-uptake and dynamic FET-slope were correlated with rCBV within tumour hotspots across patients and intra-lesionally using a mixed-effects model to account for inter-individual variation. Furthermore, maximal congruency of tumour volumes defined by FET-uptake and rCBV was determined. While the inter-individual relationship between peak static FET-uptake and rCBV could be confirmed, our intra-lesional, voxel-wise analysis revealed significant positive correlations (median r = 0.374, p < 0.0001). Similarly, significant inter- and intra-individual correlations were observed between FET-slope and rCBV. However, rCBV explained only 12% of the static and 5% of the dynamic FET-PET variance and maximal overlap of respective tumour volumes was 37% on average. Our results show that the relation between peak values of MR-based rCBV and static FET-uptake can also be observed intra-individually on a voxel basis and also applies to a dynamic FET parameter, possibly determining hotspots of higher biological malignancy. However, just a small part of the FET-PET signal variance is explained by rCBV and tumour volumes determined by the two modalities showed only moderate overlap. These findings indicate that FET-PET and MR-based rCBV provide both congruent and complimentary information on glioma biology. (orig.)
Constraint algebra in Smolin's G →0 limit of 4D Euclidean gravity
Varadarajan, Madhavan
2018-05-01
Smolin's generally covariant GNewton→0 limit of 4d Euclidean gravity is a useful toy model for the study of the constraint algebra in loop quantum gravity (LQG). In particular, the commutator between its Hamiltonian constraints has a metric dependent structure function. While a prior LQG-like construction of nontrivial anomaly free constraint commutators for the model exists, that work suffers from two defects. First, Smolin's remarks on the inability of the quantum dynamics to generate propagation effects apply. Second, the construction only yields the action of a single Hamiltonian constraint together with the action of its commutator through a continuum limit of corresponding discrete approximants; the continuum limit of a product of two or more constraints does not exist. Here, we incorporate changes in the quantum dynamics through structural modifications in the choice of discrete approximants to the quantum Hamiltonian constraint. The new structure is motivated by that responsible for propagation in an LQG-like quantization of paramatrized field theory and significantly alters the space of physical states. We study the off shell constraint algebra of the model in the context of these structural changes and show that the continuum limit action of multiple products of Hamiltonian constraints is (a) supported on an appropriate domain of states, (b) yields anomaly free commutators between pairs of Hamiltonian constraints, and (c) is diffeomorphism covariant. Many of our considerations seem robust enough to be applied to the setting of 4d Euclidean gravity.
Directory of Open Access Journals (Sweden)
Atamurat Kuchkarov
2016-01-01
Full Text Available We consider pursuit and evasion differential games of a group of m pursuers and one evader on manifolds with Euclidean metric. The motions of all players are simple, and maximal speeds of all players are equal. If the state of a pursuer coincides with that of the evader at some time, we say that pursuit is completed. We establish that each of the differential games (pursuit or evasion is equivalent to a differential game of m groups of countably many pursuers and one group of countably many evaders in Euclidean space. All the players in any of these groups are controlled by one controlled parameter. We find a condition under which pursuit can be completed, and if this condition is not satisfied, then evasion is possible. We construct strategies for the pursuers in pursuit game which ensure completion the game for a finite time and give a formula for this time. In the case of evasion game, we construct a strategy for the evader.
Two-stage sparse coding of region covariance via Log-Euclidean kernels to detect saliency.
Zhang, Ying-Ying; Yang, Cai; Zhang, Ping
2017-05-01
In this paper, we present a novel bottom-up saliency detection algorithm from the perspective of covariance matrices on a Riemannian manifold. Each superpixel is described by a region covariance matrix on Riemannian Manifolds. We carry out a two-stage sparse coding scheme via Log-Euclidean kernels to extract salient objects efficiently. In the first stage, given background dictionary on image borders, sparse coding of each region covariance via Log-Euclidean kernels is performed. The reconstruction error on the background dictionary is regarded as the initial saliency of each superpixel. In the second stage, an improvement of the initial result is achieved by calculating reconstruction errors of the superpixels on foreground dictionary, which is extracted from the first stage saliency map. The sparse coding in the second stage is similar to the first stage, but is able to effectively highlight the salient objects uniformly from the background. Finally, three post-processing methods-highlight-inhibition function, context-based saliency weighting, and the graph cut-are adopted to further refine the saliency map. Experiments on four public benchmark datasets show that the proposed algorithm outperforms the state-of-the-art methods in terms of precision, recall and mean absolute error, and demonstrate the robustness and efficiency of the proposed method. Copyright © 2017 Elsevier Ltd. All rights reserved.
Mishellany-Dutour, Anne; Woda, Alain; Labouré, Hélène; Bourdiol, Pierre; Lachaze, Pauline; Guichard, Elisabeth; Feron, Gilles
2012-01-01
We hypothesized that interindividual differences in motor activities during chewing and/or swallowing were determining factors for the transfer of volatile aroma from the in-mouth air cavity (IMAC) toward the olfactory mucosa. In our first experiment, we looked for changes in IMAC volume after saliva deglutition in 12 healthy subjects. The mean IMAC volume was measured after empty deglutition using an acoustic pharyngometer device. Based on the time course of the IMAC volume after swallowing, we discerned two groups of subjects. The first group displayed a small, constant IMAC volume (2.26 mL ±0.62) that corresponded to a high tongue position. The second group displayed a progressive increase in IMAC (from 6.82 mL ±2.37 to 22.82 mL ±3.04) that corresponded to a progressive lowering of the tongue to its resting position. In our second experiment, we investigated the relationship between IMAC volume changes after deglutition and the level of aroma release at the nostril. For this purpose, the release of menthone was measured at the nostril level in 25 subjects who consumed similar amounts of a mint tablet. The subjects were separated into two groups corresponding to two levels of menthone release: high (H) and low (L). The mean volume of IMAC was measured during and after empty deglutition. Group H displayed a small, constant amplitude of IMAC volume change after deglutition, while Group L displayed a progressive increase in IMAC. It is likely that Group H continuously released the aroma through the veloglossal isthmus as the mint was consumed, while Group L trapped the aroma in the oral cavity and then released it into the nasal cavity upon swallowing. These results show that the in vivo aroma release profile in humans depends closely on the different motor patterns at work during empty deglutition. PMID:22815986
Directory of Open Access Journals (Sweden)
Anne Mishellany-Dutour
Full Text Available We hypothesized that interindividual differences in motor activities during chewing and/or swallowing were determining factors for the transfer of volatile aroma from the in-mouth air cavity (IMAC toward the olfactory mucosa. In our first experiment, we looked for changes in IMAC volume after saliva deglutition in 12 healthy subjects. The mean IMAC volume was measured after empty deglutition using an acoustic pharyngometer device. Based on the time course of the IMAC volume after swallowing, we discerned two groups of subjects. The first group displayed a small, constant IMAC volume (2.26 mL ±0.62 that corresponded to a high tongue position. The second group displayed a progressive increase in IMAC (from 6.82 mL ±2.37 to 22.82 mL ±3.04 that corresponded to a progressive lowering of the tongue to its resting position. In our second experiment, we investigated the relationship between IMAC volume changes after deglutition and the level of aroma release at the nostril. For this purpose, the release of menthone was measured at the nostril level in 25 subjects who consumed similar amounts of a mint tablet. The subjects were separated into two groups corresponding to two levels of menthone release: high (H and low (L. The mean volume of IMAC was measured during and after empty deglutition. Group H displayed a small, constant amplitude of IMAC volume change after deglutition, while Group L displayed a progressive increase in IMAC. It is likely that Group H continuously released the aroma through the veloglossal isthmus as the mint was consumed, while Group L trapped the aroma in the oral cavity and then released it into the nasal cavity upon swallowing. These results show that the in vivo aroma release profile in humans depends closely on the different motor patterns at work during empty deglutition.
International Nuclear Information System (INIS)
Bauer, Ralf W.; Frellesen, Claudia; Schell, Boris; Lehnert, Thomas; Jacobi, Volkmar; Vogl, Thomas J.; Kerl, J.M.; Renker, Matthias; Ackermann, Hanns; Schoepf, U.J.
2011-01-01
To investigate the role of perfusion defect (PD) size on dual energy CT pulmonary blood volume assessment as predictor of right heart strain and patient outcome and its correlation with d-dimer levels in acute pulmonary embolism (PE). 53 patients with acute PE who underwent DECT pulmonary angiography were retrospectively analyzed. Pulmonary PD size caused by PE was measured on DE iodine maps and quantified absolutely (VolPD) and relatively to the total lung volume (RelPD). Signs of right heart strain (RHS) on CT were determined. Information on d-dimer levels and readmission for recurrent onset of PE and death was collected. D-dimer level was mildly (r = 0.43-0.47) correlated with PD size. Patients with RHS had significantly higher VolPD (215 vs. 73 ml) and RelPD (9.9 vs. 2.9%) than patients without RHS (p 5% RelPD, while no such events were found for patients with <5% RelPD. Pulmonary blood volume on DECT in acute PE correlates with RHS and appears to be a predictor of patient outcome in this pilot study. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Bauer, Ralf W.; Frellesen, Claudia; Schell, Boris; Lehnert, Thomas; Jacobi, Volkmar; Vogl, Thomas J.; Kerl, J.M. [Clinic of the Goethe University, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Renker, Matthias [Clinic of the Goethe University, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Medical University of South Carolina, Heart and Vascular Center, Ashley River Tower, Charleston, SC (United States); Ackermann, Hanns [Clinic of the Goethe University, Department of Biostatistics and Mathematical Modelling, Frankfurt (Germany); Schoepf, U.J. [Medical University of South Carolina, Heart and Vascular Center, Ashley River Tower, Charleston, SC (United States)
2011-09-15
To investigate the role of perfusion defect (PD) size on dual energy CT pulmonary blood volume assessment as predictor of right heart strain and patient outcome and its correlation with d-dimer levels in acute pulmonary embolism (PE). 53 patients with acute PE who underwent DECT pulmonary angiography were retrospectively analyzed. Pulmonary PD size caused by PE was measured on DE iodine maps and quantified absolutely (VolPD) and relatively to the total lung volume (RelPD). Signs of right heart strain (RHS) on CT were determined. Information on d-dimer levels and readmission for recurrent onset of PE and death was collected. D-dimer level was mildly (r = 0.43-0.47) correlated with PD size. Patients with RHS had significantly higher VolPD (215 vs. 73 ml) and RelPD (9.9 vs. 2.9%) than patients without RHS (p < 0.003). There were 2 deaths and 1 readmission due of PE in 18 patients with >5% RelPD, while no such events were found for patients with <5% RelPD. Pulmonary blood volume on DECT in acute PE correlates with RHS and appears to be a predictor of patient outcome in this pilot study. (orig.)
Thomas, Rainer; Möllmann, Christian; Ziebart, Alexander; Liu, Tanghua; David, Matthias; Hartmann, Erik K
2017-07-11
Oscillations of the arterial partial pressure of oxygen induced by varying shunt fractions occur during cyclic alveolar recruitment within the injured lung. Recently, these were proposed as a pathomechanism that may be relevant for remote organ injury following acute respiratory distress syndrome. This study examines the transmission of oxygen oscillations to the renal tissue and their tidal volume dependency. Lung injury was induced by repetitive bronchoalveolar lavage in eight anaesthetized pigs. Cyclic alveolar recruitment was provoked by high tidal volume ventilation. Oscillations of the arterial partial pressure of oxygen were measured in real-time in the macrocirculation by multi-frequency phase fluorimetry and in the renal microcirculation by combined white-light spectrometry and laser-Doppler flowmetry during tidal volume down-titration. Significant respiratory-dependent oxygen oscillations were detected in the macrocirculation and transmitted to the renal microcirculation in a substantial extent. The amplitudes of these oscillations significantly correlate to the applied tidal volume and are minimized during down-titration. In a porcine model oscillations of the arterial partial pressure of oxygen are induced by cyclic alveolar recruitment and transmitted to the renal microcirculation in a tidal volume-dependent fashion. They might play a role in organ crosstalk and remote organ damage following lung injury.
Correlator of nucleon currents in finite temperature pion gas
International Nuclear Information System (INIS)
Eletsky, V.L.
1990-01-01
A retarded correlator of two currents with nucleon quantum numbers is calculated for finite temperature T π in the chiral limit. It is shown that for euclidean momenta the leading one-loop corrections arise from direct interaction of thermal pions with the currents. A dispersive representation for the correlator shows that this interaction smears the nucleon pole over a frequency interval with width ≅ T. This interaction does not change the exponential fall-off of the correlator in euclidean space but gives an O(T 2 /F 2 π ) contribution to the pre-exponential factor. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Lee, Heon [Soon Chun Hyang University, Department of Radiology, Bucheon (Korea, Republic of); Kim, Seok Yeon [Seoul Medical Center, Department of Cardiology, Seoul (Korea, Republic of); Lee, Soo Jeong [Terarecon Korea, Seoul (Korea, Republic of); Kim, Jae Kyun [Chung-Ang University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Reddy, Ryan P.; Schoepf, U.J. [Medical University of South Carolina, Department of Radiology and Radiological Science and Division of Cardiology, Department of Medicine, Charleston, SC (United States)
2012-09-15
To investigate the correlation of right ventricular (RV) to left ventricular (LV) volume ratio measured by chest CT with pulmonary arterial systolic pressure (PASP) estimated by echocardiography. 104 patients (72.47 {+-} 13.64 years; 39 male) who had undergone chest CT and echocardiography were divided into two groups (hypertensive and normotensive) based upon an echocardiography-derived PASP of 25 mmHg. RV to LV volume ratios (RV{sub V}/LV{sub V}) were calculated. RV{sub V}/LV{sub V} was then correlated with PASP using regression analysis. The Area Under the Curve (AUC) for predicting pulmonary hypertension on chest CT was calculated. In the hypertensive group, the mean PASP was 46.29 {+-} 14.42 mmHg (29-98 mmHg) and there was strong correlation between the RV{sub V}/LV{sub V} and PASP (R = 0.82, p < 0.001). The intraobserver and interobserver correlation coefficients for RV{sub V}/LV{sub V} were 0.990 and 0.892. RV{sub V}/LV{sub V} was 1.01 {+-} 0.44 (0.51-2.77) in the hypertensive and 0.72 {+-} 0.14 (0.52-1.11) in the normotensive group (P <0.05). With 0.9 as the cutoff for RV{sub V}/LV{sub V}, sensitivity and specificity for predicting pulmonary hypertension over 40 mmHg were 79.5 % and 90 %, respectively. The AUC for predicting pulmonary hypertension was 0.87 RV/LV volume ratios on chest CT correlate well with PASP estimated by echocardiography and can be used to predict pulmonary hypertension over 40 mmHg with high sensitivity and specificity. (orig.)
Directory of Open Access Journals (Sweden)
Chuang Nie
2015-01-01
Full Text Available Background: In vivo quantification of choroidal neovascularization (CNV based on noninvasive optical coherence tomography (OCT examination and in vitro choroidal flatmount immunohistochemistry stained of CNV currently were used to evaluate the process and severity of age-related macular degeneration (AMD both in human and animal studies. This study aimed to investigate the correlation between these two methods in murine CNV models induced by subretinal injection. Methods: CNV was developed in 20 C57BL6/j mice by subretinal injection of adeno-associated viral delivery of a short hairpin RNA targeting sFLT-1 (AAV.shRNA.sFLT-1, as reported previously. After 4 weeks, CNV was imaged by OCT and fluorescence angiography. The scaling factors for each dimension, x, y, and z (μm/pixel were recorded, and the corneal curvature standard was adjusted from human (7.7 to mice (1.4. The volume of each OCT image stack was calculated and then normalized by multiplying the number of voxels by the scaling factors for each dimension in Seg3D software (University of Utah Scientific Computing and Imaging Institute, available at http://www.sci.utah.edu/cibc-software/seg3d.html. Eighteen mice were prepared for choroidal flatmounts and stained by CD31. The CNV volumes were calculated using scanning laser confocal microscopy after immunohistochemistry staining. Two mice were stained by Hematoxylin and Eosin for observing the CNV morphology. Results: The CNV volume calculated using OCT was, on average, 2.6 times larger than the volume calculated using the laser confocal microscopy. The correlation statistical analysis showed OCT measuring of CNV correlated significantly with the in vitro method (R 2 =0.448, P = 0.001, n = 18. The correlation coefficient for CNV quantification using OCT and confocal microscopy was 0.693 (n = 18, P = 0.001. Conclusions: There is a fair linear correlation on CNV volumes between in vivo and in vitro methods in CNV models induced by subretinal
Göttler, Jens; Lukas, Mathias; Kluge, Anne; Kaczmarz, Stephan; Gempt, Jens; Ringel, Florian; Mustafa, Mona; Meyer, Bernhard; Zimmer, Claus; Schwaiger, Markus; Förster, Stefan; Preibisch, Christine; Pyka, Thomas
2017-03-01
18 F-fluorethyltyrosine-(FET)-PET and MRI-based relative cerebral blood volume (rCBV) have both been used to characterize gliomas. Recently, inter-individual correlations between peak static FET-uptake and rCBV have been reported. Herein, we assess the local intra-lesional relation between FET-PET parameters and rCBV. Thirty untreated glioma patients (27 high-grade) underwent simultaneous PET/MRI on a 3 T hybrid scanner obtaining structural and dynamic susceptibility contrast sequences. Static FET-uptake and dynamic FET-slope were correlated with rCBV within tumour hotspots across patients and intra-lesionally using a mixed-effects model to account for inter-individual variation. Furthermore, maximal congruency of tumour volumes defined by FET-uptake and rCBV was determined. While the inter-individual relationship between peak static FET-uptake and rCBV could be confirmed, our intra-lesional, voxel-wise analysis revealed significant positive correlations (median r = 0.374, p dynamic FET-PET variance and maximal overlap of respective tumour volumes was 37% on average. Our results show that the relation between peak values of MR-based rCBV and static FET-uptake can also be observed intra-individually on a voxel basis and also applies to a dynamic FET parameter, possibly determining hotspots of higher biological malignancy. However, just a small part of the FET-PET signal variance is explained by rCBV and tumour volumes determined by the two modalities showed only moderate overlap. These findings indicate that FET-PET and MR-based rCBV provide both congruent and complimentary information on glioma biology.
Tamboer, P.; Scholte, H.S.; Vorst, H.C.M.
2015-01-01
In voxel-based morphometry studies of dyslexia, the relation between causal theories of dyslexia and gray matter (GM) and white matter (WM) volume alterations is still under debate. Some alterations are consistently reported, but others failed to reach significance. We investigated GM alterations in
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Sauter, Alexander W.; Spira, Daniel; Schulze, Maximilian; Pfannenberg, Christina; Claussen, Claus D.; Horger, Marius S. [Eberhard Karls University, Diagnostic and Interventional Radiology, Department of Radiology, Tuebingen (Germany); Hetzel, Juergen [Eberhard Karls University, Department of Oncology, Hematology, Immunology, Rheumatology and Pulmonology, Tuebingen (Germany); Reimold, Matthias [Eberhard Karls University, Nuclear Medicine, Department of Radiology, Tuebingen (Germany); Klotz, Ernst [Siemens Healthcare, Computed Tomography, Forchheim (Germany)
2013-05-15
The aim of this study was to investigate correlations between glucose metabolism as determined by [{sup 18}F]FDG PET/CT and tumour perfusion as quantified by volume perfusion CT in primary tumours and mediastinal lymph nodes (MLN) of patients with non-small-cell lung cancer (NSCLC). Enrolled in the study were 17 patients with NSCLC. [{sup 18}F]FDG uptake was quantified in terms of SUV{sub max} and SUV{sub avg}. Blood flow (BF), blood volume (BV) and flow extraction product (K{sup trans}) were determined as perfusion parameters. The correlations between the perfusion parameters and [{sup 18}F]FDG uptake values were subsequently evaluated. For the primary tumours, no correlations were found between perfusion parameters and [{sup 18}F]FDG uptake. In MLN, there were negative correlations between BF and SUV{sub avg} (r = -0.383), BV and SUV{sub avg} (r = -0.406), and BV and SUV{sub max} (r = -0.377), but not between BF and SUV{sub max}, K{sup trans} and SUV{sub avg}, or K{sup trans} and SUV{sub max}. Additionally, in MLN with SUV{sub max} >2.5 there were negative correlations between BF and SUV{sub avg} (r = -0.510), BV and SUV{sub avg} (r = -0.390), BF and SUV{sub max} (r = -0.536), as well as BV and SUV{sub max} (r = -0.346). Perfusion and glucose metabolism seemed to be uncoupled in large primary tumours, but an inverse correlation was observed in MLN. This information may help improve therapy planning and response evaluation. (orig.)
International Nuclear Information System (INIS)
Lee, Heon; Kim, Seok Yeon; Lee, Soo Jeong; Kim, Jae Kyun; Reddy, Ryan P.; Schoepf, U.J.
2012-01-01
To investigate the correlation of right ventricular (RV) to left ventricular (LV) volume ratio measured by chest CT with pulmonary arterial systolic pressure (PASP) estimated by echocardiography. 104 patients (72.47 ± 13.64 years; 39 male) who had undergone chest CT and echocardiography were divided into two groups (hypertensive and normotensive) based upon an echocardiography-derived PASP of 25 mmHg. RV to LV volume ratios (RV V /LV V ) were calculated. RV V /LV V was then correlated with PASP using regression analysis. The Area Under the Curve (AUC) for predicting pulmonary hypertension on chest CT was calculated. In the hypertensive group, the mean PASP was 46.29 ± 14.42 mmHg (29-98 mmHg) and there was strong correlation between the RV V /LV V and PASP (R = 0.82, p V /LV V were 0.990 and 0.892. RV V /LV V was 1.01 ± 0.44 (0.51-2.77) in the hypertensive and 0.72 ± 0.14 (0.52-1.11) in the normotensive group (P V /LV V , sensitivity and specificity for predicting pulmonary hypertension over 40 mmHg were 79.5 % and 90 %, respectively. The AUC for predicting pulmonary hypertension was 0.87 RV/LV volume ratios on chest CT correlate well with PASP estimated by echocardiography and can be used to predict pulmonary hypertension over 40 mmHg with high sensitivity and specificity. (orig.)
International Nuclear Information System (INIS)
Wielen, Gerard J. van der; Hoogeman, Mischa S.; Dohle, Gert R.; Putten, Wim L.J. van; Incrocci, Luca
2008-01-01
Purpose: To analyze the correlation between dose-volume parameters of the corpora cavernosa and erectile dysfunction (ED) after external beam radiotherapy (EBRT) for prostate cancer. Methods and Materials: Between June 1997 and February 2003, a randomized dose-escalation trial comparing 68 Gy and 78 Gy was conducted. Patients at our institute were asked to participate in an additional part of the trial evaluating sexual function. After exclusion of patients with less than 2 years of follow-up, ED at baseline, or treatment with hormonal therapy, 96 patients were eligible. The proximal corpora cavernosa (crura), the superiormost 1-cm segment of the crura, and the penile bulb were contoured on the planning computed tomography scan and dose-volume parameters were calculated. Results: Two years after EBRT, 35 of the 96 patients had developed ED. No statistically significant correlations between ED 2 years after EBRT and dose-volume parameters of the crura, the superiormost 1-cm segment of the crura, or the penile bulb were found. The few patients using potency aids typically indicated to have ED. Conclusion: No correlation was found between ED after EBRT for prostate cancer and radiation dose to the crura or penile bulb. The present study is the largest study evaluating the correlation between ED and radiation dose to the corpora cavernosa after EBRT for prostate cancer. Until there is clear evidence that sparing the penile bulb or crura will reduce ED after EBRT, we advise to be careful in sparing these structures, especially when this involves reducing treatment margins
Polli, Roberson S.; Malheiros, Jackeline M.; dos Santos, Renan; Hamani, Clement; Longo, Beatriz M.; Tannús, Alberto; Mello, Luiz E.; Covolan, Luciene
2014-01-01
Kainic acid (KA) or pilocarpine (PILO) have been used in rats to model human temporal lobe epilepsy (TLE) but the distribution and severity of structural lesions between these two models may differ. Magnetic resonance imaging (MRI) studies have used quantitative measurements of hippocampal T2 (T2HP) relaxation time and volume, but simultaneous comparative results have not been reported yet. The aim of this study was to compare the MRI T2HP and volume with histological data and frequency of seizures in both models. KA- and PILO-treated rats were imaged with a 2 T MRI scanner. T2HP and volume values were correlated with the number of cells, mossy fiber sprouting, and spontaneous recurrent seizures (SRS) frequency over the 9 months following status epilepticus (SE). Compared to controls, KA-treated rats had unaltered T2HP, pronounced reduction in hippocampal volume and concomitant cell reduction in granule cell layer, CA1 and CA3 at 3 months post SE. In contrast, hippocampal volume was unchanged in PILO-treated animals despite detectable increased T2HP and cell loss in granule cell layer, CA1 and CA3. In the following 6 months, MRI hippocampal volume remained stable with increase of T2HP signal in the KA-treated group. The number of CA1 and CA3 cells was smaller than age-matched CTL group. In contrast, PILO group had MRI volumetric reduction accompanied by reduction in the number of CA1 and CA3 cells. In this group, T2HP signal was unaltered at 6 or 9 months after status. Reductions in the number of cells were not progressive in both models. Notably, the SRS frequency was higher in PILO than in the KA model. The volumetry data correlated well with tissue damage in the epileptic brain, suggesting that MRI may be useful for tracking longitudinal hippocampal changes, allowing the assessment of individual variability and disease progression. Our results indicate that the temporal changes in hippocampal morphology are distinct for both models of TLE and that
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Meier, U.; Graewe, A.; Hajdukova, A. [Department of Neurosurgery, Unfallkrankenhaus Berlin, Warener Strasse 7, 12683, Berlin (Germany); Paris, S.; Stockheim, D.; Mutze, S. [Department of Radiology, Unfallkrankenhaus Berlin, Warener Strasse 7, 12683, Berlin (Germany)
2003-06-01
In patients with communicating or normal-pressure hydrocephalus, ventricular volume decreases following implantation of differential pressure valves. We implanted hydrostatic (Miethke dual-switch) valves in 60 patients with normal-pressure hydrocephalus (NPH) between September 1997 and December 2001. The patients underwent CT 1 year after operation, and we measured the Evans index. Although 83% of the patients showed no change in ventricular volume as assessed by this index, 72% nevertheless showed good to excellent and 16% satisfactory clinical improvement, while 12% showed no improvement. Moderate or marked reduction in ventricular size was observed in 17%, of whom 40% of these patients showed good to excellent and 20% satisfactory clinical improvement; 40% showed unsatisfactory improvement. The favourable outcome following implantation of a hydrostatic shunt thus did not correlate with decreased ventricular volume 1 year after operation, better outcomes being observed in patients with little or no alteration in ventricular size than in those with a marked decrease. Postoperative change in ventricular volume in NPH thus does not have the same significance as in patients with high-pressure hydrocephalus. (orig.)
International Nuclear Information System (INIS)
Meier, U.; Graewe, A.; Hajdukova, A.; Paris, S.; Stockheim, D.; Mutze, S.
2003-01-01
In patients with communicating or normal-pressure hydrocephalus, ventricular volume decreases following implantation of differential pressure valves. We implanted hydrostatic (Miethke dual-switch) valves in 60 patients with normal-pressure hydrocephalus (NPH) between September 1997 and December 2001. The patients underwent CT 1 year after operation, and we measured the Evans index. Although 83% of the patients showed no change in ventricular volume as assessed by this index, 72% nevertheless showed good to excellent and 16% satisfactory clinical improvement, while 12% showed no improvement. Moderate or marked reduction in ventricular size was observed in 17%, of whom 40% of these patients showed good to excellent and 20% satisfactory clinical improvement; 40% showed unsatisfactory improvement. The favourable outcome following implantation of a hydrostatic shunt thus did not correlate with decreased ventricular volume 1 year after operation, better outcomes being observed in patients with little or no alteration in ventricular size than in those with a marked decrease. Postoperative change in ventricular volume in NPH thus does not have the same significance as in patients with high-pressure hydrocephalus. (orig.)
Superintegrability in two-dimensional Euclidean space and associated polynomial solutions
International Nuclear Information System (INIS)
Kalnins, E.G.; Miller, W. Jr; Pogosyan, G.S.
1996-01-01
In this work we examine the basis functions for those classical and quantum mechanical systems in two dimensions which admit separation of variables in at least two coordinate systems. We do this for the corresponding systems defined in Euclidean space and on the two dimensional sphere. We present all of these cases from a unified point of view. In particular, all of the spectral functions that arise via variable separation have their essential features expressed in terms of their zeros. The principal new results are the details of the polynomial base for each of the nonsubgroup base, not just the subgroup cartesian and polar coordinate case, and the details of the structure of the quadratic algebras. We also study the polynomial eigenfunctions in elliptic coordinates of the N-dimensional isotropic quantum oscillator. 28 refs., 1 tab
Clear evidence of a continuum theory of 4D Euclidean simplicial quantum gravity
International Nuclear Information System (INIS)
Egawa, H.S.; Horata, S.; Yukawa, T.
2002-01-01
Four-dimensional (4D) simplicial quantum gravity coupled to both scalar fields (N X ) and gauge fields (N A ) has been studied using Monte-Carlo simulations. The matter dependence of the string susceptibility exponent γ (4) is estimated. Furthermore, we compare our numerical results with Background-Metric-Independent (BMI) formulation conjectured to describe the quantum field theory of gravity in 4D. The numerical results suggest that the 4D simplicial quantum gravity is related to the conformal gravity in 4D. Therefore, we propose a phase structure in detail with adding both scalar and gauge fields and discuss the possibility and the property of a continuum theory of 4D Euclidean simplicial quantum gravity
Non-perturbative BRST quantization of Euclidean Yang-Mills theories in Curci-Ferrari gauges
Pereira, A. D.; Sobreiro, R. F.; Sorella, S. P.
2016-10-01
In this paper we address the issue of the non-perturbative quantization of Euclidean Yang-Mills theories in the Curci-Ferrari gauge. In particular, we construct a refined Gribov-Zwanziger action for this gauge, which takes into account the presence of gauge copies as well as the dynamical formation of dimension-two condensates. This action enjoys a non-perturbative BRST symmetry recently proposed in Capri et al. (Phys. Rev. D 92(4), 045039. doi: 10.1103/PhysRevD.92.045039 arXiv:1506.06995 [hep-th], 2015). Finally, we pay attention to the gluon propagator in different space-time dimensions.
Non-perturbative BRST quantization of Euclidean Yang-Mills theories in Curci-Ferrari gauges
International Nuclear Information System (INIS)
Pereira, A.D.; Sobreiro, R.F.; Sorella, S.P.
2016-01-01
In this paper we address the issue of the non-perturbative quantization of Euclidean Yang-Mills theories in the Curci-Ferrari gauge. In particular, we construct a refined Gribov-Zwanziger action for this gauge, which takes into account the presence of gauge copies as well as the dynamical formation of dimension-two condensates. This action enjoys a non-perturbative BRST symmetry recently proposed in Capri et al. (Phys. Rev. D 92(4), 045039. doi:10.1103/PhysRevD.92.045039. arXiv:1506.06995 [hepth], 2015). Finally, we pay attention to the gluon propagator in different space-time dimensions. (orig.)
Non-perturbative BRST quantization of Euclidean Yang-Mills theories in Curci-Ferrari gauges
Energy Technology Data Exchange (ETDEWEB)
Pereira, A.D. [UFF, Universidade Federal Fluminense, Instituto de Fisica, Campus da Praia Vermelha, Niteroi, RJ (Brazil); Max Planck Institute for Gravitational Physics, Albert Einstein Institute, Potsdam (Germany); UERJ, Universidade do Estado do Rio de Janeiro, Departamento de Fisica Teorica, Rio de Janeiro (Brazil); Sobreiro, R.F. [UFF, Universidade Federal Fluminense, Instituto de Fisica, Campus da Praia Vermelha, Niteroi, RJ (Brazil); Sorella, S.P. [UERJ, Universidade do Estado do Rio de Janeiro, Departamento de Fisica Teorica, Rio de Janeiro (Brazil)
2016-10-15
In this paper we address the issue of the non-perturbative quantization of Euclidean Yang-Mills theories in the Curci-Ferrari gauge. In particular, we construct a refined Gribov-Zwanziger action for this gauge, which takes into account the presence of gauge copies as well as the dynamical formation of dimension-two condensates. This action enjoys a non-perturbative BRST symmetry recently proposed in Capri et al. (Phys. Rev. D 92(4), 045039. doi:10.1103/PhysRevD.92.045039. arXiv:1506.06995 [hepth], 2015). Finally, we pay attention to the gluon propagator in different space-time dimensions. (orig.)
Hadronic vacuum polarization in QCD and its evaluation in Euclidean spacetime
de Rafael, Eduardo
2017-07-01
We discuss a new technique to evaluate integrals of QCD Green's functions in the Euclidean based on their Mellin-Barnes representation. We present as a first application the evaluation of the lowest order hadronic vacuum polarization (HVP) contribution to the anomalous magnetic moment of the muon 1/2 (gμ-2 )HVP≡aμHVP . It is shown that with a precise determination of the slope and curvature of the HVP function at the origin from lattice QCD (LQCD), one can already obtain a result for aμHVP which may serve as a test of the determinations based on experimental measurements of the e+e- annihilation cross section into hadrons.
New results on embeddings of polyhedra and manifolds in Euclidean spaces
International Nuclear Information System (INIS)
Repovs, D; Skopenkov, A B
1999-01-01
The aim of this survey is to present several classical results on embeddings and isotopies of polyhedra and manifolds in R m . We also describe the revival of interest in this beautiful branch of topology and give an account of new results, including an improvement of the Haefliger-Weber theorem on the completeness of the deleted product obstruction to embeddability and isotopy of highly connected manifolds in R m (Skopenkov) as well as the unimprovability of this theorem for polyhedra (Freedman, Krushkal, Teichner, Segal, Skopenkov, and Spiez) and for manifolds without the necessary connectedness assumption (Skopenkov). We show how algebraic obstructions (in terms of cohomology, characteristic classes, and equivariant maps) arise from geometric problems of embeddability in Euclidean spaces. Several classical and modern results on completeness or incompleteness of these obstructions are stated and proved. By these proofs we illustrate classical and modern tools of geometric topology (engulfing, the Whitney trick, van Kampen and Casson finger moves, and their generalizations)
Euler numbers of four-dimensional rotating black holes with the Euclidean signature
International Nuclear Information System (INIS)
Ma Zhengze
2003-01-01
For a black hole's spacetime manifold in the Euclidean signature, its metric is positive definite and therefore a Riemannian manifold. It can be regarded as a gravitational instanton and a topological characteristic which is the Euler number to which it is associated. In this paper we derive a formula for the Euler numbers of four-dimensional rotating black holes by the integral of the Euler density on the spacetime manifolds of black holes. Using this formula, we obtain that the Euler numbers of Kerr and Kerr-Newman black holes are 2. We also obtain that the Euler number of the Kerr-Sen metric in the heterotic string theory with one boost angle nonzero is 2, which is in accordance with its topology
Derivatives, forms and vector fields on the κ-deformed Euclidean space
International Nuclear Information System (INIS)
Dimitrijevic, Marija; Moeller, Lutz; Tsouchnika, Efrossini
2004-01-01
The model of κ-deformed space is an interesting example of a noncommutative space, since it allows a deformed symmetry. In this paper, we present new results concerning different sets of derivatives on the coordinate algebra of κ-deformed Euclidean space. We introduce a differential calculus with two interesting sets of one-forms and higher-order forms. The transformation law of vector fields is constructed in accordance with the transformation behaviour of derivatives. The crucial property of the different derivatives, forms and vector fields is that in an n-dimensional spacetime there are always n of them. This is the key difference with respect to conventional approaches, in which the differential calculus is (n + 1)-dimensional. This work shows that derivative-valued quantities such as derivative-valued vector fields appear in a generic way on noncommutative spaces
Solution for a bipartite Euclidean traveling-salesman problem in one dimension
Caracciolo, Sergio; Di Gioacchino, Andrea; Gherardi, Marco; Malatesta, Enrico M.
2018-05-01
The traveling-salesman problem is one of the most studied combinatorial optimization problems, because of the simplicity in its statement and the difficulty in its solution. We characterize the optimal cycle for every convex and increasing cost function when the points are thrown independently and with an identical probability distribution in a compact interval. We compute the average optimal cost for every number of points when the distance function is the square of the Euclidean distance. We also show that the average optimal cost is not a self-averaging quantity by explicitly computing the variance of its distribution in the thermodynamic limit. Moreover, we prove that the cost of the optimal cycle is not smaller than twice the cost of the optimal assignment of the same set of points. Interestingly, this bound is saturated in the thermodynamic limit.
Unstable spiral waves and local Euclidean symmetry in a model of cardiac tissue
International Nuclear Information System (INIS)
Marcotte, Christopher D.; Grigoriev, Roman O.
2015-01-01
This paper investigates the properties of unstable single-spiral wave solutions arising in the Karma model of two-dimensional cardiac tissue. In particular, we discuss how such solutions can be computed numerically on domains of arbitrary shape and study how their stability, rotational frequency, and spatial drift depend on the size of the domain as well as the position of the spiral core with respect to the boundaries. We also discuss how the breaking of local Euclidean symmetry due to finite size effects as well as the spatial discretization of the model is reflected in the structure and dynamics of spiral waves. This analysis allows identification of a self-sustaining process responsible for maintaining the state of spiral chaos featuring multiple interacting spirals
Unstable spiral waves and local Euclidean symmetry in a model of cardiac tissue.
Marcotte, Christopher D; Grigoriev, Roman O
2015-06-01
This paper investigates the properties of unstable single-spiral wave solutions arising in the Karma model of two-dimensional cardiac tissue. In particular, we discuss how such solutions can be computed numerically on domains of arbitrary shape and study how their stability, rotational frequency, and spatial drift depend on the size of the domain as well as the position of the spiral core with respect to the boundaries. We also discuss how the breaking of local Euclidean symmetry due to finite size effects as well as the spatial discretization of the model is reflected in the structure and dynamics of spiral waves. This analysis allows identification of a self-sustaining process responsible for maintaining the state of spiral chaos featuring multiple interacting spirals.
Linear embeddings of finite-dimensional subsets of Banach spaces into Euclidean spaces
International Nuclear Information System (INIS)
Robinson, James C
2009-01-01
This paper treats the embedding of finite-dimensional subsets of a Banach space B into finite-dimensional Euclidean spaces. When the Hausdorff dimension of X − X is finite, d H (X − X) k are injective on X. The proof motivates the definition of the 'dual thickness exponent', which is the key to proving that a prevalent set of such linear maps have Hölder continuous inverse when the box-counting dimension of X is finite and k > 2d B (X). A related argument shows that if the Assouad dimension of X − X is finite and k > d A (X − X), a prevalent set of such maps are bi-Lipschitz with logarithmic corrections. This provides a new result for compact homogeneous metric spaces via the Kuratowksi embedding of (X, d) into L ∞ (X)
Euclidean scalar Green function in a higher dimensional global monopole space-time
International Nuclear Information System (INIS)
Bezerra de Mello, E.R.
2002-01-01
We construct the explicit Euclidean scalar Green function associated with a massless field in a higher dimensional global monopole space-time, i.e., a (1+d)-space-time with d≥3 which presents a solid angle deficit. Our result is expressed in terms of an infinite sum of products of Legendre functions with Gegenbauer polynomials. Although this Green function cannot be expressed in a closed form, for the specific case where the solid angle deficit is very small, it is possible to develop the sum and obtain the Green function in a more workable expression. Having this expression it is possible to calculate the vacuum expectation value of some relevant operators. As an application of this formalism, we calculate the renormalized vacuum expectation value of the square of the scalar field, 2 (x)> Ren , and the energy-momentum tensor, μν (x)> Ren , for the global monopole space-time with spatial dimensions d=4 and d=5
A relationship between scalar Green functions on hyperbolic and Euclidean Rindler spaces
International Nuclear Information System (INIS)
Haba, Z
2007-01-01
We derive a formula connecting in any dimension the Green function on the (D + 1)-dimensional Euclidean Rindler space and the one for a minimally coupled scalar field with a mass m in the D-dimensional hyperbolic space. The relation takes a simple form in the momentum space where the Green functions are equal at the momenta (p 0 , p) for Rindler and (m,p-hat) for hyperbolic space with a simple additive relation between the squares of the mass and the momenta. The formula has applications to finite temperature Green functions, Green functions on the cone and on the (compactified) Milne spacetime. Analytic continuations and interacting quantum fields are briefly discussed
Euclidean scalar Green's functions near the black hole and black brane horizons
International Nuclear Information System (INIS)
Haba, Z
2009-01-01
We discuss approximations of the Riemannian geometry near the horizon. If a (D + 1)-dimensional manifold N has a bifurcate Killing horizon then we approximate N by a product of the two-dimensional Rindler space R 2 and a (D - 1)-dimensional Riemannian manifold M. We obtain approximate formulae for scalar Green's functions. We study the behavior of the Green's functions near the horizon and their dimensional reduction. We show that if M is compact then the Green's function near the horizon can be approximated by the Green's function of the two-dimensional quantum field theory. The correction term is exponentially small away from the horizon. We extend the results to black brane solutions of supergravity in 10 and 11 dimensions. The near-horizon geometry can be approximated by N=AdS p xS q . We discuss the Euclidean Green's functions on N and their behavior near the horizon.
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Septa Cahyani
2018-04-01
Full Text Available The human ability to recognize a variety of objects, however complex the object, is the special ability that humans possess. Any normal human will have no difficulty in recognizing handwriting objects between an author and another author. With the rapid development of digital technology, the human ability to recognize handwriting objects has been applied in a program known as Computer Vision. This study aims to create identification system different types of handwriting capital letters that have different sizes, thickness, shape, and tilt (distinctive features in handwriting using Linear Discriminant Analysis (LDA and Euclidean Distance methods. LDA is used to obtain characteristic characteristics of the image and provide the distance between the classes becomes larger, while the distance between training data in one class becomes smaller, so that the introduction time of digital image of handwritten capital letter using Euclidean Distance becomes faster computation time (by searching closest distance between training data and data testing. The results of testing the sample data showed that the image resolution of 50x50 pixels is the exact image resolution used for data as much as 1560 handwritten capital letter data compared to image resolution 25x25 pixels and 40x40 pixels. While the test data and training data testing using the method of 10-fold cross validation where 1404 for training data and 156 for data testing showed identification of digital image handwriting capital letter has an average effectiveness of the accuracy rate of 75.39% with the average time computing of 0.4199 seconds.
Wang, Yinan; Kong, Feng; Huang, Lijie; Liu, Jia
2016-10-01
Self-esteem is a widely studied construct in psychology that is typically measured by the Rosenberg Self-Esteem Scale (RSES). However, a series of cross-sectional and longitudinal studies have suggested that a simple and widely used unidimensional factor model does not provide an adequate explanation of RSES responses due to method effects. To identify the neural correlates of the method effect, we sought to determine whether and how method effects were associated with the RSES and investigate the neural basis of these effects. Two hundred and eighty Chinese college students (130 males; mean age = 22.64 years) completed the RSES and underwent magnetic resonance imaging (MRI). Behaviorally, method effects were linked to both positively and negatively worded items in the RSES. Neurally, the right amygdala volume negatively correlated with the negative method factor, while the hippocampal volume positively correlated with the general self-esteem factor in the RSES. The neural dissociation between the general self-esteem factor and negative method factor suggests that there are different neural mechanisms underlying them. The amygdala is involved in modulating negative affectivity; therefore, the current study sheds light on the nature of method effects that are related to self-report with a mix of positively and negatively worded items. © 2015 Wiley Periodicals, Inc.
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Maggio, Angelo; Carillo, Viviana; Perna, Lucia; Fiorino, Claudio; Cozzarini, Cesare; Rancati, Tiziana; Valdagni, Riccardo; Gabriele, Pietro
2013-01-01
The aim of this study was to evaluate the correlation between the ‘true’ absolute and relative dose–volume histograms (DVHs) of the bladder wall, dose–wall histogram (DWH) defined on MRI imaging and other surrogates of bladder dosimetry in prostate cancer patients, planned both with 3D-conformal and intensity-modulated radiation therapy (IMRT) techniques. For 17 prostate cancer patients, previously treated with radical intent, CT and MRI scans were acquired and matched. The contours of bladder walls were drawn by using MRI images. External bladder surfaces were then used to generate artificial bladder walls by performing automatic contractions of 5, 7 and 10 mm. For each patient a 3D conformal radiotherapy (3DCRT) and an IMRT treatment plan was generated with a prescription dose of 77.4 Gy (1.8 Gy/fr) and DVH of the whole bladder of the artificial walls (DVH-5/10) and dose–surface histograms (DSHs) were calculated and compared against the DWH in absolute and relative value, for both treatment planning techniques. A specific software (VODCA v. 4.4.0, MSS Inc.) was used for calculating the dose–volume/surface histogram. Correlation was quantified for selected dose–volume/surface parameters by the Spearman correlation coefficient. The agreement between %DWH and DVH5, DVH7 and DVH10 was found to be very good (maximum average deviations below 2%, SD < 5%): DVH5 showed the best agreement. The correlation was slightly better for absolute (R = 0.80–0.94) compared to relative (R = 0.66–0.92) histograms. The DSH was also found to be highly correlated with the DWH, although slightly higher deviations were generally found. The DVH was not a good surrogate of the DWH (R < 0.7 for most of parameters). When comparing the two treatment techniques, more pronounced differences between relative histograms were seen for IMRT with respect to 3DCRT (p < 0.0001). (note)
Ait-Haddou, Rachid
2015-01-01
We show that the best degree reduction of a given polynomial P from degree n to m with respect to the discrete (Formula presented.)-norm is equivalent to the best Euclidean distance of the vector of h-Bézier coefficients of P from the vector
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Robert M. Yamaleev
2013-01-01
Full Text Available The hyperbolic cosines and sines theorems for the curvilinear triangle bounded by circular arcs of three intersecting circles are formulated and proved by using the general complex calculus. The method is based on a key formula establishing a relationship between exponential function and the cross-ratio. The proofs are carried out on Euclidean plane.
International Nuclear Information System (INIS)
Haba, Z.
1981-01-01
In the usual models of Euclidean field theory the Schwinger functions are moments of a positive measure. In this paper the author discusses the basic properties of the measure μ, i.e. properties of the sample paths of the random field. (Auth.)
Measuring and testing dependence by correlation of distances
Székely, Gábor J.; Rizzo, Maria L.; Bakirov, Nail K.
2007-01-01
Distance correlation is a new measure of dependence between random vectors. Distance covariance and distance correlation are analogous to product-moment covariance and correlation, but unlike the classical definition of correlation, distance correlation is zero only if the random vectors are independent. The empirical distance dependence measures are based on certain Euclidean distances between sample elements rather than sample moments, yet have a compact representation analogous to the clas...
Energy Technology Data Exchange (ETDEWEB)
Porot, C.L. [CHU Jean-Minjoz, Service de medecine nucleaire, 25 - Besancon (France); Angoue, O.R. [CHU Jean-Minjoz, laboratoire de biophysique et statistiques, 25 - Besancon (France); Berthetc, L.O. [CHU Jean-Minjoz, 25 - Besancon (France); Ungureanu, C.O.; Boulahdour, H.A.
2010-07-01
Serum albumin labeled with iodine 125 (S.A.R.I. 125) is the reference tracer used in measuring isotopic plasma volume. It has been causing a suspension of manufacturing leading to a supply disruption and resulting in the search for an alternative to measure plasma volume under consideration for measuring blood volume. Plasma transferrin labeled with indium-111 (Tf-{sup 111}In) is a potentially useful marker. To this end, we assessed the level of activity to be administered to determine a volume of distribution. The study of the correlation between the volume of distribution values obtained with S.A.R.I. 125 and Tf-{sup 111}In was then performed. Tf is an autologous protein which the labelling is easy and stable. Tf-{sup 111}In is a valid alternative to the S.A.R.I. 125 for measuring the plasma volume. The activity required for this examination shall not exceed 100 micro curies. (N.C.)
Lange, Daniel; Helck, Andreas; Rominger, Axel; Crispin, Alexander; Meiser, Bruno; Werner, Jens; Fischereder, Michael; Stangl, Manfred; Habicht, Antje
2018-07-01
Renal function of potential living kidney donors is routinely assessed with scintigraphy. Kidney anatomy is evaluated by imaging techniques such as magnetic resonance imaging (MRI). We evaluated if a MRI-based renal volumetry is a good predictor of kidney function pre- and postdonation. We retrospectively analyzed the renal volume (RV) in a MRI of 100 living kidney donors. RV was correlated with the tubular excretion rate (TER) of MAG3-scintigraphy, a measured creatinine clearance (CrCl), and the estimated glomerular filtration rate (eGFR) by Cockcroft-Gault (CG), CKD-EPI, and modification of diet in renal disease (MDRD) formula pre- and postdonation during a follow-up of 3 years. RV correlated significantly with the TER (total: r = 0.6735, P volumetry might be an alternative technique for the evaluation of split renal function and prediction of renal function postdonation in living kidney donors. © 2018 Steunstichting ESOT.
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Carlos A Sánchez-Catasús
Full Text Available Recent neuroimaging studies show that brain abnormalities in neuromyelitis optica (NMO are more frequent than earlier described. Yet, more research considering multiple aspects of NMO is necessary to better understand these abnormalities. A clinical feature of relapsing NMO (RNMO is that the incremental disability is attack-related. Therefore, association between the attack-related process and neuroimaging might be expected. On the other hand, the immunopathological analysis of NMO lesions has suggested that CNS microvasculature could be an early disease target, which could alter brain perfusion. Brain tissue volume changes accompanying perfusion alteration could also be expected throughout the attack-related process. The aim of this study was to investigate in RNMO patients, by voxel-based correlation analysis, the assumed associations between regional brain white (WMV and grey matter volumes (GMV and/or perfusion on one side, and the number of optic neuritis (ON attacks, myelitis attacks and/or total attacks on the other side. For this purpose, high resolution T1-weighted MRI and perfusion SPECT imaging were obtained in 15 RNMO patients. The results showed negative regional correlations of WMV, GMV and perfusion with the number of ON attacks, involving important components of the visual system, which could be relevant for the comprehension of incremental visual disability in RNMO. We also found positive regional correlation of perfusion with the number of ON attacks, mostly overlapping the brain area where the WMV showed negative correlation. This provides evidence that brain microvasculature is an early disease target and suggests that perfusion alteration could be important in the development of brain structural abnormalities in RNMO.
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Sabin Khadka
2016-07-01
Full Text Available Background: Attention Deficit Hyperactivity Disorder (ADHD is a prevalent neurodevelopmental disorder affecting children, adolescents, and adults. Its etiology is not well-understood, but it is increasingly believed to result from diverse pathophysiologies that affect the structure and function of specific brain circuits. Although one of the best-studied neurobiological abnormalities in ADHD is reduced fronto-striatal-cerebellar gray matter volume, its specific genetic correlates are largely unknown. Methods: In this study, T1-weighted MR images of brain structure were collected from 198 adolescents (63 ADHD-diagnosed. A multivariate parallel independent component analysis technique (Para-ICA identified imaging-genetic relationships between regional gray matter volume and single nucleotide polymorphism data. Results: Para-ICA analyses extracted 14 components from genetic data and 9 from MR data. An iterative cross-validation using randomly-chosen sub-samples indicated acceptable stability of these ICA solutions. A series of partial correlation analyses controlling for age, sex, and ethnicity revealed two genotype-phenotype component pairs significantly differed between ADHD and non-ADHD groups, after a Bonferroni correction for multiple comparisons. The brain phenotype component not only included structures frequently found to have abnormally low volume in previous ADHD studies, but was also significantly associated with ADHD differences in symptom severity and performance on cognitive tests frequently found to be impaired in patients diagnosed with the disorder. Pathway analysis of the genotype component identified several different biological pathways linked to these structural abnormalities in ADHD. Conclusions: Some of these pathways implicate well-known dopaminergic neurotransmission and neurodevelopment hypothesized to be abnormal in ADHD. Other more recently implicated pathways included glutamatergic and GABA-eric physiological systems
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Faria, Sergio L.; Menard, Sonia; Devic, Slobodan; Sirois, Christian; Souhami, Luis; Lisbona, Robert; Freeman, Carolyn R.
2008-01-01
Purpose: Fluorodeoxyglucose-positron emission tomography (FDG-PET)/computed tomography (CT) is more accurate than CT in determining the extent of non-small-cell lung cancer. We performed a study to evaluate the impact of FDG-PET/CT on the radiotherapy volume delineation compared with CT without using any mathematical algorithm and to correlate the findings with the pathologic examination findings. Methods and Materials: A total of 32 patients with proven non-small-cell lung cancer, pathologic specimens from the mediastinum and lung primary, and pretreatment chest CT and FDG-PET/CT scans were studied. For each patient, two data sets of theoretical gross tumor volumes were contoured. One set was determined using the chest CT only, and the second, done separately, was based on the co-registered FDG-PET/CT data. The disease stage of each patient was determined using the TNM staging system for three data sets: the CT scan only, FDG-PET/CT scan, and pathologic findings. Results: Pathologic examination altered the CT-determined stage in 22 (69%) of 32 patients and the PET-determined stage in 16 (50%) of 32 patients. The most significant alterations were related to the N stage. PET altered the TNM stage in 15 (44%) of 32 patients compared with CT alone, but only 7 of these 15 alterations were confirmed by the pathologic findings. With respect to contouring the tumor volume for radiotherapy, PET altered the contour in 18 (56%) of 32 cases compared with CT alone. Conclusion: The contour of the tumor volume of non-small-cell lung cancer patients with co-registered FDG-PET/CT resulted in >50% alterations compared with CT targeting, findings similar to those of other publications. However, the significance of this change is unknown. Furthermore, pathologic examination showed that PET is not always accurate and histologic examination should be obtained to confirm the findings of PET whenever possible
International Nuclear Information System (INIS)
Ding Xiuping; Li Hongjun; Li Baosheng; Wang Dongqing
2012-01-01
Objective: To analyze the correlation between the changes of myocardial enzyme level in serum before and after radiotherapy and dose - volume histogram (DVH) parameters of the heart. Methods: A total of 102 patients with 68 cases of lung cancer and 34 cases of esophageal cancer were recruited. All patients received three-dimensional conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy (IMRT), with the radiation beams passing through the heart. Aspartate aminotransferase (AST), creatine kinase (CK), creatine kinase isozyme (CK-MB), lactate dehydrogenase (LDH), α-hydroxybutyrate dehydrogenase (α-HBDH) were determined in the serum before and after radiotherapy. All the enzyme levels before and after radiotherapy were compared through paired t-test. Independent sample t-test was conducted between sub-groups. And the dose-volume histogram (DVH) parameters of the heart were calculated (the volume percentage of heart receiving dose equal to or exceeding x Gy (V x ). The correlation between myocardial enzyme level and DVH parameters was analyzed through Pearson method. Results: Serum AST, CK-MB, LDH, α-HBDH levels increased significantly after radiotherapy (19.42: 27.89, 14.72:19.57, 178.80 : 217.57, 140.32 : 176.25, t =-3.39 - -6.92, all P=0.000). In Group IMRT, significant correlations between the increase of myocardial enzyme concentration and DVH parameters of the heart are found, AST with V 20 , V 25 , V 30 of heart ( r=0.302 - 0.431, P =0.039 - 0.003), CK with V 30 of heart (r=0.345, P=0.013), and CK-MB, LDH, α-HBDH with V 25 , V 30 (r=0.465 -0.376, P=0.001-0.005). In Group CRT, there are significant correlations between changes of CK-MB, LDH level and V 30 of heart (r =0.330, 0.274, P=0.014, 0.033), α-HBDH and V 25 , V 30 , and V 35 of heart (r=0.270-0.331, P=0.046-0.014). When the irradiation dose was more than 50 Gy, significant correlations were found between the concentration changes of AST, LDH, α-HBDH and V 25 , V 30 of heart (r=0
Non-Hermitian systems of Euclidean Lie algebraic type with real energy spectra
Dey, Sanjib; Fring, Andreas; Mathanaranjan, Thilagarajah
2014-07-01
We study several classes of non-Hermitian Hamiltonian systems, which can be expressed in terms of bilinear combinations of Euclidean-Lie algebraic generators. The classes are distinguished by different versions of antilinear (PT)-symmetries exhibiting various types of qualitative behaviour. On the basis of explicitly computed non-perturbative Dyson maps we construct metric operators, isospectral Hermitian counterparts for which we solve the corresponding time-independent Schrödinger equation for specific choices of the coupling constants. In these cases general analytical expressions for the solutions are obtained in the form of Mathieu functions, which we analyze numerically to obtain the corresponding energy spectra. We identify regions in the parameter space for which the corresponding spectra are entirely real and also domains where the PT symmetry is spontaneously broken and sometimes also regained at exceptional points. In some cases it is shown explicitly how the threshold region from real to complex spectra is characterized by the breakdown of the Dyson maps or the metric operator. We establish the explicit relationship to models currently under investigation in the context of beam dynamics in optical lattices.
Anthropology in the post-Euclidean State, or from textual to oral anthropology
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Antonio Luigi Palmisano
2011-12-01
Full Text Available The actual crisis of anthropology is examined in relation to its wide public success. Anthropology has prospered and the anthropologists have proliferated becoming more specific. But the theoretical debate has come to a halt over the last decades. The article suggests that both the methodology and the form of expression of the ethnographic report have developed and then become crystallized around actual protocols. A critique of the dichotomy Subject/Object, namely the key discussion about the notion of Otherness, is here reexamined as the testimony for an immanent “non-protocolar” character of anthropology. This critique together with the end of anthropology as tekhne, i.e. as protocolar activity, will allow anthropology to go on enhancing many other social and non social sciences. The article discusses the re-definition of anthropology in the context of Daseinanalysis and, therefore the changing relation between man and power, that is between the social actor and the post-Euclidean State in the era of the tekhne.
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Q. Zhou
2017-07-01
Full Text Available Visual Odometry (VO is a critical component for planetary robot navigation and safety. It estimates the ego-motion using stereo images frame by frame. Feature points extraction and matching is one of the key steps for robotic motion estimation which largely influences the precision and robustness. In this work, we choose the Oriented FAST and Rotated BRIEF (ORB features by considering both accuracy and speed issues. For more robustness in challenging environment e.g., rough terrain or planetary surface, this paper presents a robust outliers elimination method based on Euclidean Distance Constraint (EDC and Random Sample Consensus (RANSAC algorithm. In the matching process, a set of ORB feature points are extracted from the current left and right synchronous images and the Brute Force (BF matcher is used to find the correspondences between the two images for the Space Intersection. Then the EDC and RANSAC algorithms are carried out to eliminate mismatches whose distances are beyond a predefined threshold. Similarly, when the left image of the next time matches the feature points with the current left images, the EDC and RANSAC are iteratively performed. After the above mentioned, there are exceptional remaining mismatched points in some cases, for which the third time RANSAC is applied to eliminate the effects of those outliers in the estimation of the ego-motion parameters (Interior Orientation and Exterior Orientation. The proposed approach has been tested on a real-world vehicle dataset and the result benefits from its high robustness.
$O(N)$ model in Euclidean de Sitter space: beyond the leading infrared approximation
Nacir, Diana López; Trombetta, Leonardo G
2016-01-01
We consider an $O(N)$ scalar field model with quartic interaction in $d$-dimensional Euclidean de Sitter space. In order to avoid the problems of the standard perturbative calculations for light and massless fields, we generalize to the $O(N)$ theory a systematic method introduced previously for a single field, which treats the zero modes exactly and the nonzero modes perturbatively. We compute the two-point functions taking into account not only the leading infrared contribution, coming from the self-interaction of the zero modes, but also corrections due to the interaction of the ultraviolet modes. For the model defined in the corresponding Lorentzian de Sitter spacetime, we obtain the two-point functions by analytical continuation. We point out that a partial resummation of the leading secular terms (which necessarily involves nonzero modes) is required to obtain a decay at large distances for massless fields. We implement this resummation along with a systematic double expansion in an effective coupling c...
Maximally-localized position, Euclidean path-integral, and thermodynamics in GUP quantum mechanics
Bernardo, Reginald Christian S.; Esguerra, Jose Perico H.
2018-04-01
In dealing with quantum mechanics at very high energies, it is essential to adapt to a quasiposition representation using the maximally-localized states because of the generalized uncertainty principle. In this paper, we look at maximally-localized states as eigenstates of the operator ξ = X + iβP that we refer to as the maximally-localized position. We calculate the overlap between maximally-localized states and show that the identity operator can be expressed in terms of the maximally-localized states. Furthermore, we show that the maximally-localized position is diagonal in momentum-space and that the maximally-localized position and its adjoint satisfy commutation and anti-commutation relations reminiscent of the harmonic oscillator commutation and anti-commutation relations. As application, we use the maximally-localized position in developing the Euclidean path-integral and introduce the compact form of the propagator for maximal localization. The free particle momentum-space propagator and the propagator for maximal localization are analytically evaluated up to quadratic-order in β. Finally, we obtain a path-integral expression for the partition function of a thermodynamic system using the maximally-localized states. The partition function of a gas of noninteracting particles is evaluated. At temperatures exceeding the Planck energy, we obtain the gas' maximum internal energy N / 2 β and recover the zero heat capacity of an ideal gas.
Rizzo, Giuseppe; Capponi, Alessandra; Cavicchioni, Ottavia; Vendola, Marianne; Arduini, Domenico
2007-12-01
To assess the agreement of stroke volume (SV) measured with two-dimensional (2D) ultrasonography with Doppler capability (vs) four-dimensional (4D) with spatiotemporal image correlation (STIC) in normal and growth restricted fetuses. 2D Doppler and 4D STIC were used to measure SV of 40 normal fetuses at 20 to 22 and 28 to 32 weeks, and 16 growth-restricted fetuses at 26 to 34 weeks of gestation. Intraclass correlation was used to evaluate the agreement between left and right SV obtained by the two techniques, and proportionate Bland-Altman plots constructed. The time necessary to obtain SV was analyzed. The intraclass correlation coefficient between 2D Doppler and 4D STIC measurements for the left ventricle were 0.977 and 0.980 for the right ventricle. The proportionate limits of agreement between the two methods were 18.7 to 23.9% for the left ventricle and - 20.9 to 21.7% for the right ventricle. The time necessary to measure SV was significantly shorter with 4D STIC (3.1 (vs) 7.9 min p < 0.0001) than with 2D Doppler. There is a good agreement between SV measured either by 2D Doppler or by 4D STIC. The 4D STIC represents a simple and rapid technique to estimate fetal SV and promises to become the method of choice. Copyright (c) 2007 John Wiley & Sons, Ltd.
Durato, M. V.; Albano, A. M.; Rapp, P. E.; Nawang, S. A.
2015-06-01
The validity of ERPs as indices of stable neurophysiological traits is partially dependent on their stability over time. Previous studies on ERP stability, however, have reported diverse stability estimates despite using the same component scoring methods. This present study explores a novel approach in investigating the longitudinal stability of average ERPs—that is, by treating the ERP waveform as a time series and then applying Euclidean Distance and Kolmogorov-Smirnov analyses to evaluate the similarity or dissimilarity between the ERP time series of different sessions or run pairs. Nonlinear dynamical analysis show that in the absence of a change in medical condition, the average ERPs of healthy human adults are highly longitudinally stable—as evaluated by both the Euclidean distance and the Kolmogorov-Smirnov test.
International Nuclear Information System (INIS)
Durato, M V; Nawang, S A; Albano, A M; Rapp, P E
2015-01-01
The validity of ERPs as indices of stable neurophysiological traits is partially dependent on their stability over time. Previous studies on ERP stability, however, have reported diverse stability estimates despite using the same component scoring methods. This present study explores a novel approach in investigating the longitudinal stability of average ERPs—that is, by treating the ERP waveform as a time series and then applying Euclidean Distance and Kolmogorov-Smirnov analyses to evaluate the similarity or dissimilarity between the ERP time series of different sessions or run pairs. Nonlinear dynamical analysis show that in the absence of a change in medical condition, the average ERPs of healthy human adults are highly longitudinally stable—as evaluated by both the Euclidean distance and the Kolmogorov-Smirnov test. (paper)
Generalized inequalities for quantum correlations with hidden variables
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Vinduska, M.
1991-01-01
Renowned inequalities for quantum correlations are generalized for the case when quantum system cannot be described with an absolute independent measure of the probability. Such a formulation appears to be suitable for the formulation of the hidden variables theory in terms of non-Euclidean geometry. 10 refs
Hierarchical clustering using correlation metric and spatial continuity constraint
Stork, Christopher L.; Brewer, Luke N.
2012-10-02
Large data sets are analyzed by hierarchical clustering using correlation as a similarity measure. This provides results that are superior to those obtained using a Euclidean distance similarity measure. A spatial continuity constraint may be applied in hierarchical clustering analysis of images.
International Nuclear Information System (INIS)
Muschitz, S.; Petrow, P.; Briot, E.; Petit, C.; De Crevoisier, R.; Duvillard, P.; Morice, P.; Haie-Meder, C.
2004-01-01
Background and purpose: This study correlates the treated volume, the GTV and the CTV at the time of intracavitary brachytherapy (BT) with the histopathological findings obtained by surgery (S) in 33 patients (pts) with cervix carcinoma. Patients and methods: Sixteen pts (group I), FIGO stage IB1 (1), IB2 (4), IIB (10), IIIB (1), received external beam radiotherapy (EBT) with a total dose of 45 Gy in 5 weeks and concomitant CISPLATIN 40 mg/m 2 weekly, followed by BT up to a total dose of 15 Gy. S was performed 6-8 weeks thereafter. Seventeen pts (group II), FIGO IA2 (1), IB1 (14), IIB (2), were treated by BT alone with a total dose of 60 Gy and S after 6-8 weeks. All pts had a MRI examination after BT with a moulded applicator in situ for exact delineation of GTV, CTV and critical organs and a 3D dosimetry directly from MRI data. Results: In group I (EBT+BT+S), the histopathological findings showed complete tumour sterilization (CR) in 56% of pts. Residual disease (RD) was found in 43%. Dosimetric data showed in pts with CR a larger mean treated volume (213 vs. 166 cm 3 ) and a better mean coverage of the GTV and the CTV by the reference isodose (99 and 91%) as in pts with RD (85 and 77%). In group II (BT+S), CR was found in 52%, RD in 41%. Dosimetric data showed a larger mean treated volume (154 vs. 109 cm 3 ) for pts with RD and a mean coverage of the GTV and the CTV by the reference isodose of 97 and 84% vs. 89 and 80% for pts with CR. Conclusions: An incomplete coverage of the GTV and/or the CTV by the reference isodose is an important risk factor for RD at the time of surgery. Furthermore, for pts who received BT alone, tumour size seemed to be a limiting factor for an accurate coverage of the CTV by the reference isodose
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Roeske John C
2003-05-01
Full Text Available Abstract Background To determine whether the dose-volume histograms (DVH's for the rectum and bladder constructed using biological-effective dose (BED-DVH's better correlate with late gastrointestinal (GI and genitourinary (GU toxicity after treatment with external beam radiotherapy for prostate cancer than conventional DVH's (C-DVH's. Methods The charts of 190 patients treated with external beam radiotherapy with a minimum follow-up of 2 years were reviewed. Six patients (3.2% were found to have RTOG grade 3 GI toxicity, and similarly 6 patients (3.2% were found to have RTOG grade 3 GU toxicity. Average late C-DVH's and BED-DVH's of the bladder and rectum were computed for these patients as well as for matched-pair control patients. For each matched pair the following measures of normalized difference in the DVH's were computed: (a δAUC = (Area Under Curve [AUC] in grade 3 patient – AUC in grade 0 patient/(AUC in grade 0 patient and (b δV60 = (Percent volume receiving = 60 Gy [V60] in grade 3 patient – V60 in grade 0 patient/(V60 in grade 0 patient. Results As expected, the grade 3 curve is to the right of and above the grade 0 curve for all four sets of average DVH's – suggesting that both the C-DVH and the BED-DVH can be used for predicting late toxicity. δAUC was higher for the BED-DVH's than for the C-DVH's – 0.27 vs 0.23 (p = 0.036 for the rectum and 0.24 vs 0.20 (p = 0.065 for the bladder. δV60 was also higher for the BED-DVH's than for the C-DVH's – 2.73 vs 1.49 for the rectum (p = 0.021 and 1.64 vs 0.71 (p = 0.021 for the bladder. Conclusions When considering well-established dosimetric endpoints used in evaluating treatment plans, BED-DVH's for the rectum and bladder correlate better with late toxicity than C-DVH's and should be considered when attempting to minimize late GI and GU toxicity after external beam radiotherapy for prostate cancer.
Zhang, Dongwen; Zhu, Qingsong; Xiong, Jing; Wang, Lei
2014-04-27
In a deforming anatomic environment, the motion of an instrument suffers from complex geometrical and dynamic constraints, robot assisted minimally invasive surgery therefore requires more sophisticated skills for surgeons. This paper proposes a novel dynamic virtual fixture (DVF) to enhance the surgical operation accuracy of admittance-type medical robotics in the deforming environment. A framework for DVF on the Euclidean Group SE(3) is presented, which unites rotation and translation in a compact form. First, we constructed the holonomic/non-holonomic constraints, and then searched for the corresponded reference to make a distinction between preferred and non-preferred directions. Second, different control strategies are employed to deal with the tasks along the distinguished directions. The desired spatial compliance matrix is synthesized from an allowable motion screw set to filter out the task unrelated components from manual input, the operator has complete control over the preferred directions; while the relative motion between the surgical instrument and the anatomy structures is actively tracked and cancelled, the deviation relative to the reference is compensated jointly by the operator and DVF controllers. The operator, haptic device, admittance-type proxy and virtual deforming environment are involved in a hardware-in-the-loop experiment, human-robot cooperation with the assistance of DVF controller is carried out on a deforming sphere to simulate beating heart surgery, performance of the proposed DVF on admittance-type proxy is evaluated, and both human factors and control parameters are analyzed. The DVF can improve the dynamic properties of human-robot cooperation in a low-frequency (0 ~ 40 rad/sec) deforming environment, and maintain synergy of orientation and translation during the operation. Statistical analysis reveals that the operator has intuitive control over the preferred directions, human and the DVF controller jointly control the
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Dakhel Ghani Omran
2017-11-01
Full Text Available Smoking represents a worldwide problem and affects various body functions. The present study was conducted to evaluate the available concentration of some clotting factors in smokers polycythemic male patients. A total number of subjects was 120, 80 smokers males were affected with polycythemia and the remainders 40 males were healthy and served as a control group. The polycythemic patients were subdivided into two groups according to their ages (first group ranged between 30-40 years old and the second group ranged between 41-50 years old. PCV, clotting factor (FI, FVII and FVIII were detected. The results of present study indicated that the levels of prothrombin time (PT and activated partial thromboplastine time (APTT were significantly increased (p˂ 0.05 in both groups of polycythemia in comparison with control group. Regarding concentration of fibrinogen factor (FI and serum prothrombin conversion accelerator factor (FVII were elevated (P˂ 0.05 in both groups and pointed out a positive correlation (r = 0.437, r = 0.378, respectively with packed cell volume (PCV when compared with those of control group. On the other hand, concentration of antihemophilic factor (FVIII recorded a significant fall (p˂ 0.05 in both tested groups and indicated a low correlation (r = 0.292. The possible explanation to the changes mentioned above is based on the fact that confirm smoking is a dangerous material containing different toxic substances that affect the vital organs of the body and induce abnormalities of hemostatic mechanism
Vos, Pauline
2009-01-01
When studying correlations, how do the three bivariate correlation coefficients between three variables relate? After transforming Pearson's correlation coefficient r into a Euclidean distance, undergraduate students can tackle this problem using their secondary school knowledge of geometry (Pythagoras' theorem and similarity of triangles).…
International Nuclear Information System (INIS)
Wang, B; Pan, B; Tao, R; Lubineau, G
2017-01-01
The use of digital volume correlation (DVC) in combination with a laboratory x-ray computed tomography (CT) for full-field internal 3D deformation measurement of opaque materials has flourished in recent years. During x-ray tomographic imaging, the heat generated by the x-ray tube changes the imaging geometry of x-ray scanner, and further introduces noticeable errors in DVC measurements. In this work, to provide practical guidance high-accuracy DVC measurement, the errors in displacements and strains measured by DVC due to the self-heating for effect of a commercially available x-ray scanner were experimentally investigated. The errors were characterized by performing simple rescan tests with different scan durations. The results indicate that the maximum strain errors associated with the self-heating of the x-ray scanner exceed 400 µε . Possible approaches for minimizing or correcting these displacement and strain errors are discussed. Finally, a series of translation and uniaxial compression tests were performed, in which strain errors were detected and then removed using pre-established artificial dilatational strain-time curve. Experimental results demonstrate the efficacy and accuracy of the proposed strain error correction approach. (paper)
International Nuclear Information System (INIS)
Okada, Tomiro
1993-01-01
Left ventricular (LV) diastolic functions in 23 patients with aortic regurgitation (AR) and 22 patients with mitral regurgitation (MR) were evaluated by gated blood pool scintigraphy. LV myocardial biopsy was performed during open heart surgery, and LV myocardial ultrastructural changes were evaluated by electron microscope. Correlation between LV diastolic function and myocardial ultrastructural changes was examined. It was suggested that preoperative LV diastolic dysfunction occurred earlier than LV systolic dysfunction in patients with AR and MR. LV early diastolic dysfunction was especially significant in patients with AR. LV systolic function was significantly improved postoperatively compared with LV diastolic function in patients with AR and MR. It was suggested that LV interstitial fibrosis caused LV diastolic dysfunction in patients with AR and MR, and insufficiency of myocardial thickening as compensation in patients with MR. It was presumed that LV diastolic dysfunction was irreversible in patients with AR and MR in the distant postoperative period due to persistence of the preoperative myocardial ultrastructural change, e.g., interstitial fibrosis. These LV diastolic indices measured by gated pool scintigraphy were useful in predicting LV ultrastructural changes and postoperative LV dysfunction in patients with LV volume-overloaded valvular heart disease. (author)
Directory of Open Access Journals (Sweden)
Alicia Gauffin
2018-05-01
Full Text Available On the basis of the Volume Correlation Model (VCM as well as data on steel consumption and scrap collection per industry sector (construction, automotive, industrial goods, and consumer goods, it was possible to estimate service lifetimes of steel in the United States between 1900 and 2016. Input data on scrap collection per industry sector was based on a scrap survey conducted by the World Steel Association for a static year in 2014 in the United States. The lifetimes of steel calculated with the VCM method were within the range of previously reported measured lifetimes of products and applications for all industry sectors. Scrapped (and apparent lifetimes of steel compared with measured lifetimes were calculated to be as follows: a scrapped lifetime of 29 years for the construction sector (apparent lifetime: 52 years compared with 44 years measured in 2014. Industrial goods: 16 (27 years compared with 19 years measured in 2010. Consumer goods: 12 (14 years compared with 13 years measured in 2014. Automotive sector: 14 (19 years compared with 17 years measured in 2011. Results show that the VCM can estimate reasonable values of scrap collection and availability per industry sector over time.
Wang, B
2017-02-15
The use of digital volume correlation (DVC) in combination with a laboratory x-ray computed tomography (CT) for full-field internal 3D deformation measurement of opaque materials has flourished in recent years. During x-ray tomographic imaging, the heat generated by the x-ray tube changes the imaging geometry of x-ray scanner, and further introduces noticeable errors in DVC measurements. In this work, to provide practical guidance high-accuracy DVC measurement, the errors in displacements and strains measured by DVC due to the self-heating for effect of a commercially available x-ray scanner were experimentally investigated. The errors were characterized by performing simple rescan tests with different scan durations. The results indicate that the maximum strain errors associated with the self-heating of the x-ray scanner exceed 400 µε. Possible approaches for minimizing or correcting these displacement and strain errors are discussed. Finally, a series of translation and uniaxial compression tests were performed, in which strain errors were detected and then removed using pre-established artificial dilatational strain-time curve. Experimental results demonstrate the efficacy and accuracy of the proposed strain error correction approach.
Gómez, Daviel; Hernández, L Ázaro; Yabor, Lourdes; Beemster, Gerrit T S; Tebbe, Christoph C; Papenbrock, Jutta; Lorenzo, José Carlos
2018-03-15
Plant scientists usually record several indicators in their abiotic factor experiments. The common statistical management involves univariate analyses. Such analyses generally create a split picture of the effects of experimental treatments since each indicator is addressed independently. The Euclidean distance combined with the information of the control treatment could have potential as an integrating indicator. The Euclidean distance has demonstrated its usefulness in many scientific fields but, as far as we know, it has not yet been employed for plant experimental analyses. To exemplify the use of the Euclidean distance in this field, we performed an experiment focused on the effects of mannitol on sugarcane micropropagation in temporary immersion bioreactors. Five mannitol concentrations were compared: 0, 50, 100, 150 and 200 mM. As dependent variables we recorded shoot multiplication rate, fresh weight, and levels of aldehydes, chlorophylls, carotenoids and phenolics. The statistical protocol which we then carried out integrated all dependent variables to easily identify the mannitol concentration that produced the most remarkable integral effect. Results provided by the Euclidean distance demonstrate a gradually increasing distance from the control in function of increasing mannitol concentrations. 200 mM mannitol caused the most significant alteration of sugarcane biochemistry and physiology under the experimental conditions described here. This treatment showed the longest statistically significant Euclidean distance to the control treatment (2.38). In contrast, 50 and 100 mM mannitol showed the lowest Euclidean distances (0.61 and 0.84, respectively) and thus poor integrated effects of mannitol. The analysis shown here indicates that the use of the Euclidean distance can contribute to establishing a more integrated evaluation of the contrasting mannitol treatments.
Ait-Haddou, Rachid
2015-06-04
We show that the best degree reduction of a given polynomial P from degree n to m with respect to the discrete (Formula presented.)-norm is equivalent to the best Euclidean distance of the vector of h-Bézier coefficients of P from the vector of degree raised h-Bézier coefficients of polynomials of degree m. Moreover, we demonstrate the adequacy of h-Bézier curves for approaching the problem of weighted discrete least squares approximation. Applications to discrete orthogonal polynomials are also presented. © 2015 Springer Science+Business Media Dordrecht
Directory of Open Access Journals (Sweden)
Yuxian Zhang
2015-01-01
Full Text Available The quality index model in slashing process is difficult to build by reason of the outliers and noise data from original data. To the above problem, a fuzzy neural network based on non-Euclidean distance clustering is proposed in which the input space is partitioned into many local regions by the fuzzy clustering based on non-Euclidean distance so that the computation complexity is decreased, and fuzzy rule number is determined by validity function based on both the separation and the compactness among clusterings. Then, the premise parameters and consequent parameters are trained by hybrid learning algorithm. The parameters identification is realized; meanwhile the convergence condition of consequent parameters is obtained by Lyapunov function. Finally, the proposed method is applied to build the quality index model in slashing process in which the experimental data come from the actual slashing process. The experiment results show that the proposed fuzzy neural network for quality index model has lower computation complexity and faster convergence time, comparing with GP-FNN, BPNN, and RBFNN.
Zhang, Ying-Ying; Yang, Cai; Zhang, Ping
2017-08-01
In this paper, we present a novel bottom-up saliency detection algorithm from the perspective of covariance matrices on a Riemannian manifold. Each superpixel is described by a region covariance matrix on Riemannian Manifolds. We carry out a two-stage sparse coding scheme via Log-Euclidean kernels to extract salient objects efficiently. In the first stage, given background dictionary on image borders, sparse coding of each region covariance via Log-Euclidean kernels is performed. The reconstruction error on the background dictionary is regarded as the initial saliency of each superpixel. In the second stage, an improvement of the initial result is achieved by calculating reconstruction errors of the superpixels on foreground dictionary, which is extracted from the first stage saliency map. The sparse coding in the second stage is similar to the first stage, but is able to effectively highlight the salient objects uniformly from the background. Finally, three post-processing methods-highlight-inhibition function, context-based saliency weighting, and the graph cut-are adopted to further refine the saliency map. Experiments on four public benchmark datasets show that the proposed algorithm outperforms the state-of-the-art methods in terms of precision, recall and mean absolute error, and demonstrate the robustness and efficiency of the proposed method. Copyright © 2017 Elsevier Ltd. All rights reserved.
Kimyon Comert, Gunsu; Esin, Sertac; Caglar, Gamze Sinem; Yirci, Bulent; Ozdemir, Sedat; Demirtas, Selda; Kandemir, Omer
2018-01-24
This study aimed to determine the relationship between birth weight, and maternal serum insulin-like growth factor-binding protein-1 (IGFBP-1) and kisspeptin-1 (KISS-1) levels, and first-trimester fetal volume (FV) based on three-dimensional ultrasonography. The study included 142 pregnant women at gestational week 11°-13 6 . All fetuses were imaged ultrasonographically by the same physician. Maternal blood samples were collected at the time of ultrasonographic evaluation and analyzed for IGFBP-1 and KISS-1 levels via enzyme-linked immunosorbent assay (ELISA). Maternal and neonatal weights were recorded at birth. Birth weight ≤10th and the >90th percentiles was defined as small and large for gestational age (SGA and LGA), respectively. Median crown-rump length (CRL), FV, and maternal serum IGFBP-1 and KISS-1 levels were 58.2 mm (35.3-79.2 mm), 16.3 cm 3 (3.8-34.4 cm 3 ), 68.1 ng mL -1 (3.8-377.9 mL -1 ), and 99.7 ng L -1 (42.1-965.3 ng L -1 ), respectively. First-trimester IGFBP-1 levels were significantly lower in the mothers with LGA neonates (p KISS-1 levels. IGFBP-1 levels and maternal weight at delivery were negatively correlated with neonatal birth weight. There was no correlation between CRL or FV and maternal IGFBP-1 or KISS1 levels (p > .05). The maternal IGFBP-1 level during the first trimester was a significant independent factor for SGA and LGA neonates (Odds ratio (OR): 0.011, 95%CI: 1.005-1.018, p KISS-1 level. As compared to the maternal KISS-1 level, the maternal IGFBP-1 level during the first trimester might be a better biomarker of fetal growth. Additional larger scale studies are needed to further delineate the utility of IGFBP-1 as a marker of abnormal birth weight.
International Nuclear Information System (INIS)
Schad, L.R.; Bock, M.; Baudendistel, K.; Essig, M.; Debus, J.; Knopp, M.V.; Engenhart, R.; Lorenz, W.J.
1996-01-01
The authors report the sterotactic correlation of different MRI-techniques [MR angiography (MRA), MRI, blood bolus tagging (STAR), and functional MRI] in 10 patients with cerebral arteriovenous malformations (AVM) and its application in precision radiotherapy planning. The patient's head was fixed in a stereotactic localization system. By phantom measurements different materials (steel, aluminium, titanium, plastic, wood, ceramics) used for the stereotactic system were tested for mechanical stability and geometrical MR image distortion. All metallic stereotactic rings led to a more or less dramatic geometrical distortion and signal cancellation in the MR images. The best properties - nearly no distortion and high mechanical stability - are provided by a ceramic ring. If necessary, the remaining geometrical MR image distortion can be 'corrected' by calculations based on modeling the distortion as a fourth-order 2D-polynomial. Using this method multimodality matching can be performed automatically as long as all images are acquired in the same examination and the patient is sufficiently immobilized. Precise definition of the target volume could be performed by the radiotherapist either directly in MR images or in calculated projection MR angiograms. As a result, information about the hemodynamics of the AVM was provided by a 3D-phase-contrast flow measurement and a dynamic MRA with the STAR technique leading to an improved definition of the size of the nidus, and the pattern of the venous drainage. In addition, functional MRI was performed in patients with lesions close to the primary motor cortex area leading to an improved definition of structures at risk for high-dose application in radiosurgery. (orig./MG)
Lončarić-Katušin, Mirjana; Belavić, Matija; Žunić, Josip; Gučanin, Snježana; Žilić, Antonio; Korać, Želimir
2010-01-01
Aggressive large volume resuscitation is obligatory to achieve necessary tissue oxygenation. An adequate venous preload normalizes global hemodynamics and avoids multiorgan failure (MOF) and death in patients with multiple injuries. Large volume resuscitation is associated with complications in minimally monitored patients. A properly guided resuscitation procedure will finally prevent MOF and patient death. Transpulmonary thermodilution technique and gastric tonometry are used in venous prel...
Mirage in temporal correlation functions for baryon-baryon interactions in lattice QCD
International Nuclear Information System (INIS)
Iritani, T.; Doi, T.; Aoki, S.; Gongyo, S.; Hatsuda, T.; Ikeda, Y.; Inoue, T.; Ishii, N.; Murano, K.; Nemura, H.; Sasaki, K.
2016-01-01
Single state saturation of the temporal correlation function is a key condition to extract physical observables such as energies and matrix elements of hadrons from lattice QCD simulations. A method commonly employed to check the saturation is to seek for a plateau of the observables for large Euclidean time. Identifying the plateau in the cases having nearby states, however, is non-trivial and one may even be misled by a fake plateau. Such a situation takes place typically for a system with two or more baryons. In this study, we demonstrate explicitly the danger from a possible fake plateau in the temporal correlation functions mainly for two baryons (ΞΞ and NN), and three and four baryons ("3He and "4He) as well, employing (2+1)-flavor lattice QCD at m_π=0.51 GeV on four lattice volumes with L= 2.9, 3.6, 4.3 and 5.8 fm. Caution is required when drawing conclusions about the bound NN, 3N and 4N systems based only on the standard plateau fitting of the temporal correlation functions.
Wang, Yong-Long; Jiang, Hua; Zong, Hong-Shi
2017-08-01
In the spirit of the thin-layer quantization approach, we give the formula of the geometric influences of a particle confined to a curved surface embedded in three-dimensional Euclidean space. The geometric contributions can result from the reduced commutation relation between the acted function depending on normal variable and the normal derivative. According to the formula, we obtain the geometric potential, geometric momentum, geometric orbital angular momentum, geometric linear Rashba, and cubic Dresselhaus spin-orbit couplings. As an example, a truncated cone surface is considered. We find that the geometric orbital angular momentum can provide an azimuthal polarization for spin, and the sign of the geometric Dresselhaus spin-orbit coupling can be flipped through the inclination angle of generatrix.
Renormalized G-convolution of n-point functions in quantum field theory. I. The Euclidean case
International Nuclear Information System (INIS)
Bros, Jacques; Manolessou-Grammaticou, Marietta.
1977-01-01
The notion of Feynman amplitude associated with a graph G in perturbative quantum field theory admits a generalized version in which each vertex v of G is associated with a general (non-perturbative) nsub(v)-point function Hsup(nsub(v)), nsub(v) denoting the number of lines which are incident to v in G. In the case where no ultraviolet divergence occurs, this has been performed directly in complex momentum space through Bros-Lassalle's G-convolution procedure. The authors propose a generalization of G-convolution which includes the case when the functions Hsup(nsub(v)) are not integrable at infinity but belong to a suitable class of slowly increasing functions. A finite part of the G-convolution integral is then defined through an algorithm which closely follows Zimmermann's renormalization scheme. The case of Euclidean four-momentum configurations is only treated
International Nuclear Information System (INIS)
Bezerra de Mello, E.R.
2006-01-01
In this paper we present, in a integral form, the Euclidean Green function associated with a massless scalar field in the five-dimensional Kaluza-Klein magnetic monopole superposed to a global monopole, admitting a nontrivial coupling between the field with the geometry. This Green function is expressed as the sum of two contributions: the first one related with uncharged component of the field, is similar to the Green function associated with a scalar field in a four-dimensional global monopole space-time. The second contains the information of all the other components. Using this Green function it is possible to study the vacuum polarization effects on this space-time. Explicitly we calculate the renormalized vacuum expectation value * (x)Φ(x)> Ren , which by its turn is also expressed as the sum of two contributions
Jantarasaengaram, Surasak; Vairojanavong, Kittipong
2010-09-15
Theoretically, a cross-sectional image of any cardiac planes can be obtained from a STIC fetal heart volume dataset. We described a method to display 11 fetal echocardiographic planes from STIC volumes. Fetal heart volume datasets were acquired by transverse acquisition from 200 normal fetuses at 15 to 40 weeks of gestation. Analysis of the volume datasets using the described technique to display 11 echocardiographic planes in the multiplanar display mode were performed offline. Volume datasets from 18 fetuses were excluded due to poor image resolution. The mean visualization rates for all echocardiographic planes at 15-17, 18-22, 23-27, 28-32 and 33-40 weeks of gestation fetuses were 85.6% (range 45.2-96.8%, N = 31), 92.9% (range 64.0-100%, N = 64), 93.4% (range 51.4-100%, N = 37), 88.7%(range 54.5-100%, N = 33) and 81.8% (range 23.5-100%, N = 17) respectively. Overall, the applied technique can favorably display the pertinent echocardiographic planes. Description of the presented method provides a logical approach to explore the fetal heart volumes.
Relation between Euclidean and real time calculations of Green functions at finite temperature
International Nuclear Information System (INIS)
Bochkarev, A.
1993-01-01
We find a relation between the semiclassical approximation of the temperature (Matsubara) two-point correlator and the corresponding classical Green function in real time at finite temperature. The anharmonic oscillator at finite temperature is used to illustrate our statement, which is however of rather general origin
Energy Technology Data Exchange (ETDEWEB)
Yoshiura, Takashi; Hiwatashi, Akio; Yamashita, Koji; Takayama, Yukihisa; Kamano, Norihiro; Honda, Hiroshi [Kyushu University, Department of Clinical Radiology, Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka (Japan); Ohyagi, Yasumasa; Kira, Jun-ichi [Kyushu University, Department of Neurology, Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka (Japan); Monji, Akira; Kawashima, Toshiro [Kyushu University, Department of Neuropsychiatry, Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka (Japan)
2011-02-15
To determine which brain regions are relevant to deterioration in abstract reasoning as measured by Raven's Colored Progressive Matrices (CPM) in the context of dementia. MR images of 37 consecutive patients including 19 with Alzheimer's disease (AD) and 18 with amnestic mild cognitive impairment (aMCI) were retrospectively analyzed. All patients were administered the CPM. Regional grey matter (GM) volume was evaluated according to the regimens of voxel-based morphometry, during which a non-linear registration algorithm called Diffeomorphic Anatomical Registration Through Exponentiated Lie algebra was employed. Multiple regression analyses were used to map the regions where GM volumes were correlated with CPM scores. The strongest correlation with CPM scores was seen in the left middle frontal gyrus while a region with the largest volume was identified in the left superior temporal gyrus. Significant correlations were seen in 14 additional regions in the bilateral cerebral hemispheres and right cerebellum. Deterioration of abstract reasoning ability in AD and aMCI measured by CPM is related to GM loss in multiple regions, which is in close agreement with the results of previous activation studies. (orig.)
International Nuclear Information System (INIS)
Yoshiura, Takashi; Hiwatashi, Akio; Yamashita, Koji; Takayama, Yukihisa; Kamano, Norihiro; Honda, Hiroshi; Ohyagi, Yasumasa; Kira, Jun-ichi; Monji, Akira; Kawashima, Toshiro
2011-01-01
To determine which brain regions are relevant to deterioration in abstract reasoning as measured by Raven's Colored Progressive Matrices (CPM) in the context of dementia. MR images of 37 consecutive patients including 19 with Alzheimer's disease (AD) and 18 with amnestic mild cognitive impairment (aMCI) were retrospectively analyzed. All patients were administered the CPM. Regional grey matter (GM) volume was evaluated according to the regimens of voxel-based morphometry, during which a non-linear registration algorithm called Diffeomorphic Anatomical Registration Through Exponentiated Lie algebra was employed. Multiple regression analyses were used to map the regions where GM volumes were correlated with CPM scores. The strongest correlation with CPM scores was seen in the left middle frontal gyrus while a region with the largest volume was identified in the left superior temporal gyrus. Significant correlations were seen in 14 additional regions in the bilateral cerebral hemispheres and right cerebellum. Deterioration of abstract reasoning ability in AD and aMCI measured by CPM is related to GM loss in multiple regions, which is in close agreement with the results of previous activation studies. (orig.)
Directory of Open Access Journals (Sweden)
Robin J Keeley
Full Text Available BACKGROUND: Sex differences in spatial memory function have been reported with mixed results in the literature, with some studies showing male advantages and others showing no differences. When considering estrus cycle in females, results are mixed at to whether high or low circulating estradiol results in an advantage in spatial navigation tasks. Research involving humans and rodents has demonstrated males preferentially employ Euclidean strategies and utilize geometric cues in order to spatially navigate, whereas females employ landmark strategies and cues in order to spatially navigate. METHODOLOGY/PRINCIPAL FINDINGS: This study used the water-based snowcone maze in order to assess male and female preference for landmark or geometric cues, with specific emphasis placed on the effects of estrus cycle phase for female rat. Performance and preference for the geometric cue was examined in relation to total hippocampal and hippocampal subregions (CA1&2, CA3 and dentate gyrus volumes and entorhinal cortex thickness in order to determine the relation between strategy and spatial performance and brain area size. The study revealed that males outperformed females overall during training trials, relied on the geometric cue when the platform was moved and showed significant correlations between entorhinal cortex thickness and spatial memory performance. No gross differences in behavioural performance was observed within females when accounting for cyclicity, and only total hippocampal volume was correlated with performance during the learning trials. CONCLUSIONS/SIGNIFICANCE: This study demonstrates the sex-specific use of cues and brain areas in a spatial learning task.
Kitaoka, Hitomi; Kawashima, Hiroko
2018-03-01
In mammography, breast compression is necessary and an important factor influencing image quality. The purpose of this study was to determine the influence of the menstrual cycle on compression-induced pain during mammography and to evaluate the association between the thickness and volume of the mammary gland and pain. We examined basal body temperature and categorized the menstrual cycle into five phases. We executed breast compression in the craniocaudal view using a customized compression plate, to which we introduced an opening. We measured the thickness of the mammary gland under compression using echography. Immediately after releasing the compression, we evaluated pain using the visual analogue scale. We performed magnetic resonance imaging (MRI) on the same day and measured the volume of the mammary gland. The thickness of the mammary gland, pain, and the volume of the mammary gland were minimal in the late follicular phase and maximal in the late luteal and early follicular phases. It was shown that the changes in the thickness and volume of the mammary gland during the menstrual cycle accounted for the changes in compression-induced pain. On MRI examination of each breast quadrant, the same changes were observed in areas A and C. In area A, it was shown that both the anatomical characteristics and the increase in volume of the mammary gland were associated with pain. We concluded that the late follicular phase constitutes the optimal timing for mammography.
Energy Technology Data Exchange (ETDEWEB)
Cardoso, R.S.; Peixoto, J.G.P., E-mail: ricardo@ird.gov.br [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)
2017-07-01
Ionization chambers are, in principle, the simplest gaseous detectors. Its normal operation is based on the all charges collection created by gas volume direct ionization, through the application of an electric field. In order to guarantee the measurements’ traceability obtained during the comparison with the BIPM, new tests were performed. (author)
Pomeraniec, I Jonathan; Bond, Aaron E; Lopes, M Beatriz; Jane, John A
2016-02-01
Normal pressure hydrocephalus (NPH) remains most often a clinical diagnosis and has been widely considered responsive to the placement of a cerebrospinal fluid (CSF) shunt. The high incidence of patients with Alzheimer's disease (AD) with NPH symptoms leads to poorer outcomes than would be expected in patients with NPH alone. This article reviews a series of patients operated on for presumed NPH in whom preoperative high-volume lumbar puncture (HVLP) and intraoperative cortical brain biopsies were performed. The data derived from these procedures were then used to understand the incidence of AD in patients presenting with NPH symptoms and to analyze the efficacy of HVLP in patients with NPH and patients with concurrent AD (NPH+AD). A review of the outcomes of shunt surgery is provided. The cases of all patients who underwent placement of a CSF shunt for NPH from 1998 to 2013 at the University of Virginia by the senior author were retrospectively reviewed. Patients who underwent HVLP and patients who underwent cortical brain biopsies were stratified based on the biopsy results into an NPH-only group and an NPH+AD group. The HVLP results and outcomes were then compared in these 2 groups. From 1998 to 2013, 142 patients underwent shunt operations because of a preoperative clinical diagnosis of NPH. Of the patients with a shunt who had a diagnosis of NPH, 105 (74%) received HVLPs. Of 142 shunt-treated patients with NPH, 27 (19%) were determined to have concomitant Alzheimer's pathology based on histopathological findings at the time of shunting. Patients who underwent repeat biopsies had an initial positive outcome. After they clinically deteriorated, they underwent repeat biopsies during shunt interrogation, and 13% of the repeat biopsies demonstrated Alzheimer's pathology. Improvements in gait and cognition did not reach significance between the NPH and NPH+AD groups. In total, 105 patients underwent HVLP before shunt placement. In the NPH cohort, 44.6% of patients
On infinitesimal increase of volumes of morphological transforms
DEFF Research Database (Denmark)
Kiderlen, Markus; Rataj, Jan
2007-01-01
Let B (“black”) and W (“white”) be disjoint compact test sets in the d-dimensional Euclidean space and consider the volume of all its simultaneous shifts keeping B inside and W outside a compact set A. If the union of B and W is rescaled by a factor tending to zero, then the rescaled volume...... for the hit-or-miss function. Secondly, in a design based setting, different random digitizations of a deterministic set A are treated. It is shown how the number of configurations in such a digitization is related to the surface area measure of A as the lattice distance converges to zero....
International Nuclear Information System (INIS)
Baardwijk, Angela van; Bosmans, Geert; Boersma, Liesbeth; Buijsen, Jeroen; Wanders, Stofferinus; Hochstenbag, Monique; Suylen, Robert-Jan van; Dekker, Andre; Dehing-Oberije, Cary; Houben, Ruud; Bentzen, Soren M.; Kroonenburgh, Marinus van; Lambin, Philippe; Ruysscher, Dirk de
2007-01-01
Purpose: To compare source-to-background ratio (SBR)-based PET-CT auto-delineation with pathology in non-small-cell lung cancer (NSCLC) and to investigate whether auto-delineation reduces the interobserver variability compared with manual PET-CT-based gross tumor volume (GTV) delineation. Methods and Materials: Source-to-background ratio-based auto-delineation was compared with macroscopic tumor dimensions to assess its validity in 23 tumors. Thereafter, GTVs were delineated manually on 33 PET-CT scans by five observers for the primary tumor (GTV-1) and the involved lymph nodes (GTV-2). The delineation was repeated after 6 months with the auto-contour provided. This contour was edited by the observers. For comparison, the concordance index (CI) was calculated, defined as the ratio of intersection and the union of two volumes (A intersection B)/(A union B). Results: The maximal tumor diameter of the SBR-based auto-contour correlated strongly with the macroscopic diameter of primary tumors (correlation coefficient = 0.90) and was shown to be accurate for involved lymph nodes (sensitivity 67%, specificity 95%). The median auto-contour-based target volumes were smaller than those defined by manual delineation for GTV-1 (31.8 and 34.6 cm 3 , respectively; p = 0.001) and GTV-2 (16.3 and 21.8 cm 3 , respectively; p 0.02). The auto-contour-based method showed higher CIs than the manual method for GTV-1 (0.74 and 0.70 cm 3 , respectively; p 3 , respectively; p = 0.11). Conclusion: Source-to-background ratio-based auto-delineation showed a good correlation with pathology, decreased the delineated volumes of the GTVs, and reduced the interobserver variability. Auto-contouring may further improve the quality of target delineation in NSCLC patients
National Research Council Canada - National Science Library
Berens, Alan
2000-01-01
.... Volume 1 presents a description of changes made to the probability of detection (POD) analysis program of Mil-STD-1823 and the statistical evaluation of modifications that were made to version 3 of the Eddy Current Inspection System (ECIS v3...
International Nuclear Information System (INIS)
Hurmuzlu, Meysan; Ovrebo, Kjell; Wentzel-Larsen, Tore; Muren, Ludvig Paul; Viste, Asgaut; Smaaland, Rune
2010-01-01
Purpose: To investigate the association of high-dose preoperative chemoradiotherapy (CRT) and dose-volume histogram (DVH) parameters of lungs with incidence of postoperative pulmonary complications and to identify predictive clinical factors of pulmonary complications. Methods: Data of 65 patients were collected retrospectively. Thirty-five patients underwent transthoracic esophagectomy (TTE) alone and 30 received cisplatin and 5-fluorouracil, concomitant with radiotherapy, median dose 66 Gy, and followed by TTE. From the DVH for each lung alone and for both lungs together as one organ we generated total lung volume, mean radiotherapy dose, relative and absolute volumes receiving more than a threshold dose, and relative and absolute volumes receiving less than a threshold dose. Postoperative pulmonary complications were defined as pneumonia or respiratory failure. Results: Sixty percent of the patients in the TTE alone group had postoperative pulmonary complications versus 63% in the CRT + TTE group. Postoperative mortality was 8.6% and 16.7% in the respective patient groups (p = NS). None of the DVH parameters was associated with postoperative pulmonary complications. Squamous cell carcinoma was an adverse factor related to increased postoperative pulmonary complications. Conclusion: High-dose preoperative CRT was not associated with increased postoperative pulmonary complications in this cohort of esophageal cancer patients.
LENUS (Irish Health Repository)
Coleman, Linda
2013-11-01
This study investigates the impact of systematic multileaf collimator (MLC) positional errors on gamma analysis results used for quality assurance (QA) of Rapidarc treatments. In addition, this study evaluates the relationship of these gamma analysis results and clinical dose volume histogram metrics (DVH) for Rapidarc treatment plans.
Liang, De; Ye, Linqiang; Jiang, Xiaobing; Huang, Weiquan; Yao, Zhensong; Tang, Yongchao; Zhang, Shuncong; Jin, Daxiang
2014-11-01
To investigate the risk factors of cement leakage in percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fracture (OVCF). Between March 2011 and March 2012, 98 patients with single level OVCF were treated by PVP, and the clinical data were analyzed retrospectively. There were 13 males and 85 females, with a mean age of 77.2 years (range, 54-95 years). The mean disease duration was 43 days (range, 15-120 days), and the mean T score of bone mineral density (BMD) was -3.8 (range, -6.7- -2.5). Bilateral transpedicular approach was used in all the patients. The patients were divided into cement leakage group and no cement leakage group by occurrence of cement leakage based on postoperative CT. Single factor analysis was used to analyze the difference between 2 groups in T score of BMD, operative level, preoperative anterior compression degree of operative vertebrae, preoperative middle compression degree of operative vertebrae, preoperative sagittal Cobb angle of operative vertebrae, preoperative vertebral body wall incompetence, cement volume, and volume ratio of intravertebral bone cement to vertebral body. All relevant factors were introduced to logistic regression analysis to analyze the risk factors of cement leakage. All procedures were performed successfully. The mean operation time was 40 minutes (range, 30-50 minutes), and the mean volume ratio of intravertebral bone cement to vertebral body was 24.88% (range, 7.84%-38.99%). Back pain was alleviated significantly in all the patients postoperatively. All patients were followed up with a mean time of 8 months (range, 6-12 months). Cement leakage occurred in 49 patients. Single factor analysis showed that there were significant differences in the volume ratio of intravertebral bone cement to vertebral body and preoperative vertebral body wall incompetence between 2 groups (P 0.05). The logistic regression analysis showed that the volume ratio of intravertebral bone cement to vertebral body (P
Directory of Open Access Journals (Sweden)
Ibrahim S. Khattab
2017-02-01
Full Text Available Density, viscosity, surface tension and molar volume of propylene glycol + water mixtures at 293, 298, 303, 308, 313, 318, and 323 K are reported, compared with the available literature data and the Jouyban–Acree model was used for mathematical correlation of the data. The mean relative deviation (MRD was used as an error criterion and the MRD values for data correlation of density, viscosity, surface tension and molar volume at different investigated temperatures are 0.1 ± 0.1%, 7.6 ± 6.4%, 3.4 ± 3.7%, and 0.4 ± 0.4%, respectively. The corresponding MRDs for the predicted properties after training the model using the experimental data at 298 K are 0.1 ± 0.2%, 12.8 ± 9.3%, 4.7 ± 4.1% and 0.6 ± 0.5%, respectively for density, viscosity, surface tension, and molar volume data.
Energy Technology Data Exchange (ETDEWEB)
Carrasco-Choque, Ana Luz; Fernandez-de Lara, Yeni; Vivas-Bonilla, Ingrid; Romero-Trejo, Cecilia [Medica Sur Clinic and Foundation, Magnetic Resonance Unit, Mexico City (Mexico); Villa, Antonio R. [UNAM, Division de Investigacion, Facultad de Medicina, Mexico City (Mexico); Roldan-Valadez, Ernesto [Medica Sur Clinic and Foundation, Magnetic Resonance Unit, Mexico City (Mexico); Medica Sur Clinic and Foundation, Coordination of Research and Innovation, Magnetic Resonance Unit, Mexico City (Mexico)
2015-10-15
To evaluate the clinical efficacy of magnetic resonance-guided focused ultrasound surgery in a Mexican mestizo population. This retrospective study included 159 women (mean age 37 ± 6.4 years, range 22-53 years) from 2008 to 2010. Two hundred sixty-eight symptomatic uterine fibroids were treated using MR-guided focused ultrasound surgery. Parameters included initial perfused volume, final perfused volume, non-perfused volume (NPV), and treated volume ratio (TVR). Follow-up up to 15 months assessed treatment efficacy and symptomatic relief. Non-parametric statistics and the Kaplan-Meier method were performed. T{sub 2}-weighted hypointense fibroids showed a frequency of 93.6 %; isointense and hyperintense fibroids had frequencies of 5.60 and 1.1 %. There was a negative correlation between NPV and age (r = -0.083, p = 0.307) and treatment time (r = -0.253, p = 0.001). Median TVR was 96.0 % in small fibroids and 76.5 % in large fibroids. Involution of 50 % and 80 % was achieved at months 6-7 and month 11, respectively. Relief of symptoms was significant (p < 0.05). Our data show that higher TVR attained immediately post-treatment of MRgFUS favours higher involution percentages at follow-up; however, careful patient selection and use of pretreatment imaging are important components for predicting success using MR-guided focused ultrasound surgery. (orig.)
Albaugh, Matthew D; Ducharme, Simon; Collins, D Louis; Botteron, Kelly N; Althoff, Robert R; Evans, Alan C; Karama, Sherif; Hudziak, James J
2013-05-01
Recent functional connectivity studies have demonstrated that, in resting humans, activity in a dorsally-situated neocortical network is inversely associated with activity in the amygdalae. Similarly, in human neuroimaging studies, aspects of emotion regulation have been associated with increased activity in dorsolateral, dorsomedial, orbital and ventromedial prefrontal regions, as well as concomitant decreases in amygdalar activity. These findings indicate the presence of two countervailing systems in the human brain that are reciprocally related: a dorsally-situated cognitive control network, and a ventrally-situated limbic network. We investigated the extent to which this functional reciprocity between limbic and dorsal neocortical regions is recapitulated from a purely structural standpoint. Specifically, we hypothesized that amygdalar volume would be related to cerebral cortical thickness in cortical regions implicated in aspects of emotion regulation. In 297 typically developing youths (162 females, 135 males; 572 MRIs), the relationship between cortical thickness and amygdalar volume was characterized. Amygdalar volume was found to be inversely associated with thickness in bilateral dorsolateral and dorsomedial prefrontal, inferior parietal, as well as bilateral orbital and ventromedial prefrontal cortices. Our findings are in line with previous work demonstrating that a predominantly dorsally-centered neocortical network is reciprocally related to core limbic structures such as the amygdalae. Future research may benefit from investigating the extent to which such cortical-limbic morphometric relations are qualified by the presence of mood and anxiety psychopathology. Copyright © 2012 Elsevier Inc. All rights reserved.
Kim, Won Hwa; Chung, Moo K; Singh, Vikas
2013-01-01
The analysis of 3-D shape meshes is a fundamental problem in computer vision, graphics, and medical imaging. Frequently, the needs of the application require that our analysis take a multi-resolution view of the shape's local and global topology, and that the solution is consistent across multiple scales. Unfortunately, the preferred mathematical construct which offers this behavior in classical image/signal processing, Wavelets, is no longer applicable in this general setting (data with non-uniform topology). In particular, the traditional definition does not allow writing out an expansion for graphs that do not correspond to the uniformly sampled lattice (e.g., images). In this paper, we adapt recent results in harmonic analysis, to derive Non-Euclidean Wavelets based algorithms for a range of shape analysis problems in vision and medical imaging. We show how descriptors derived from the dual domain representation offer native multi-resolution behavior for characterizing local/global topology around vertices. With only minor modifications, the framework yields a method for extracting interest/key points from shapes, a surprisingly simple algorithm for 3-D shape segmentation (competitive with state of the art), and a method for surface alignment (without landmarks). We give an extensive set of comparison results on a large shape segmentation benchmark and derive a uniqueness theorem for the surface alignment problem.
International Nuclear Information System (INIS)
Abd El-Monsef, M.M.; Kozae, A.M.; Seddeek, M.K.; Medhat, T.; Sharshar, T.; Badran, H.M.
2004-01-01
Form the geological point of view, the origin and transport of black and normal sands is particularly important. Black and normal sands came to their places along the Mediterranean-sea coast after transport by some natural process. Both types of sands have different radiological properties. This study is, therefore, attempts to use mathematical methods to classify Egyptian sand samples collected from 42 locations in an area of 40 x 19 km 2 based on their radioactivity contents. The use of all information resulted from the experimental measurements of radioactivity contents as well as some other parameters can be a time and effort consuming task. So that the process of eliminating unnecessary attributes is of prime importance. This elimination process of the superfluous attributes that cannot affect the decision was carried out. Some topological techniques to classify the information systems resulting from the radioactivity measurements were then carried out. These techniques were applied in Euclidean and quasi-discrete topological cases. While there are some applications in environmental radioactivity of the former case, the use of the quasi-discrete in the so-called rough set information analysis is new in such a study. The mathematical methods are summarized and the results and their radiological implications are discussed. Generally, the results indicate no radiological anomaly and it supports the hypothesis previously suggested about the presence of two types of sand in the studied area
Biess, Armin
2013-01-01
The study of the kinematic and dynamic features of human arm movements provides insights into the computational strategies underlying human motor control. In this paper a differential geometric approach to movement control is taken by endowing arm configuration space with different non-Euclidean metric structures to study the predictions of the generalized minimum-jerk (MJ) model in the resulting Riemannian manifold for different types of human arm movements. For each metric space the solution of the generalized MJ model is given by reparametrized geodesic paths. This geodesic model is applied to a variety of motor tasks ranging from three-dimensional unconstrained movements of a four degree of freedom arm between pointlike targets to constrained movements where the hand location is confined to a surface (e.g., a sphere) or a curve (e.g., an ellipse). For the latter speed-curvature relations are derived depending on the boundary conditions imposed (periodic or nonperiodic) and the compatibility with the empirical one-third power law is shown. Based on these theoretical studies and recent experimental findings, I argue that geodesics may be an emergent property of the motor system and that the sensorimotor system may shape arm configuration space by learning metric structures through sensorimotor feedback.
International Nuclear Information System (INIS)
Kao, Chia-Hung; Hsieh, Te-Chun; Yu, Chun-Yen; Yen, Kuo-Yang; Yang, Shih-Neng; Wang, Yao-Ching; Liang, Ji-An; Chien, Chun-Ru; Chen, Shang-Wen
2010-01-01
To define a suitable threshold setting for gross tumor volume (GTV) when using 18 Fluoro-deoxyglucose positron emission tomography and computed tomogram (PET/CT) for radiotherapy planning in head and neck cancer (HNC). Fifteen HNC patients prospectively received PET/CT simulation for their radiation treatment planning. Biological target volume (BTV) was derived from PET/CT-based GTV of the primary tumor. The BTVs were defined as the isodensity volumes when adjusting different percentage of the maximal standardized uptake value (SUVmax), excluding any artifact from surrounding normal tissues. CT-based primary GTV (C-pGTV) that had been previously defined by radiation oncologists was compared with the BTV. Suitable threshold level (sTL) could be determined when BTV value and its morphology using a certain threshold level was observed to be the best fitness of the C-pGTV. Suitable standardized uptake value (sSUV) was calculated as the sTL multiplied by the SUVmax. Our result demonstrated no single sTL or sSUV method could achieve an optimized volumetric match with the C-pGTV. The sTL was 13% to 27% (mean, 19%), whereas the sSUV was 1.64 to 3.98 (mean, 2.46). The sTL was inversely correlated with the SUVmax [sTL = -0.1004 Ln (SUVmax) + 0.4464; R 2 = 0.81]. The sSUV showed a linear correlation with the SUVmax (sSUV = 0.0842 SUVmax + 1.248; R 2 = 0.89). The sTL was not associated with the value of C-pGTVs. In PET/CT-based BTV for HNC, a suitable threshold or SUV level can be established by correlating with SUVmax rather than using a fixed threshold
DEFF Research Database (Denmark)
Mains, Jill Rachel; Donskov, Frede; Pedersen, Erik Morre
2017-01-01
= 7). Using a prototype software program (Advanced Perfusion and Permeability Application, Philips Healthcare, Best, the Netherlands), blood volume (BV), blood flow (BF), and permeability surface area product (PS) were calculated for each tumor at baseline, week 5, and week 10. These parameters......OBJECTIVES: The aim was to explore the potential for using dynamic contrast-enhanced computed tomography as a noninvasive functional imaging biomarker before and during the early treatment of metastatic renal cell carcinoma (mRCC). MATERIALS AND METHODS: Dynamic contrast-enhanced computed...
International Nuclear Information System (INIS)
Bubelev, E.G.; Kuchin, I.A.
1998-01-01
The necessity of creating mesophysics is motivated on the basis of a general likeness of the description of many phenomena and processes in micro- and macroworld. For a general and detailed investigation of the former in modern high energy physics (HEP), the Absolute (arising from Minkovsky and irrespective of any reference system) universal approach is used. Its two conceptually new branches are non-linear system-dynamic and non-Euclidean evolutionary ones. They are complementary ones and completely adequate to an extreme complexity of directly unobservable HEP objects. Some primary problems of them are briefly made clear on the basis of synergetics principles and HEP's internal Lobachevsky-Euclidean geometry. They are noted as the primary content of the Lobachevsky-Poincare Programme (LPP) the idea of which has been proposed recently for their successive solution
International Nuclear Information System (INIS)
Clara, Rene A.; Gomez Marigliano, Ana C.; Solimo, Horacio N.
2007-01-01
Density and viscosity measurements for pure chloroform and methyl isobutyl ketone at T = (283.15, 293.15, 303.15, and 313.15) K as well as for the binary system {x 1 chloroform + (1 - x 1 ) methyl isobutyl ketone} at the same temperatures were made over the whole concentration range. The experimental results were fitted to empirical equations, which permit the calculation of these properties over the whole concentration and temperature ranges studied. Data of the binary mixture were further used to calculate the excess molar volume and viscosity deviation. The (vapour + liquid) equilibrium (VLE) at T = 303.15 K for this binary system was also measured in order to calculate the activity coefficients and the excess molar Gibbs energy. This binary system shows no azeotrope and negative deviations from ideal behaviour. The excess or deviation properties were fitted to the Redlich-Kister polynomial relation to obtain their coefficients and standard deviations
Institute of Scientific and Technical Information of China (English)
赵长伟; 马沛生
2003-01-01
Visosities and densities at ,several temperatures from 293.15 K to 313.15K are reported for L-ascorbic acid in aqueous glucose and sucrose solutions at different concentrations.The parameters of density,Viscosity coefficient B and partial molar volume are calculated by regression.The experimental results show that densities and viscositis decrease as temperature increases at the same solute and solvent (glucose and sucrose aueous solution)concentrations,and increase with concentration of glucose and sucrose at the same solute concentration and temperature,B increases with concentration of glucose and sucrose and temaperature,L-ascorbic acid is sturcture-breaker or structure-making for the glucose and sucrose aqueous solutions ,Furthermore,the solute-solvent interactions in ternary systems of water-glucose-electrolyte and water-sucrose-electrolyte are discussed.
Sinclair, Michael B [Albuquerque, NM; Pfeifer, Kent B [Los Lunas, NM; Flemming, Jeb H [Albuquerque, NM; Jones, Gary D [Tijeras, NM; Tigges, Chris P [Albuquerque, NM
2010-04-13
A correlation spectrometer can detect a large number of gaseous compounds, or chemical species, with a species-specific mask wheel. In this mode, the spectrometer is optimized for the direct measurement of individual target compounds. Additionally, the spectrometer can measure the transmission spectrum from a given sample of gas. In this mode, infrared light is passed through a gas sample and the infrared transmission signature of the gasses present is recorded and measured using Hadamard encoding techniques. The spectrometer can detect the transmission or emission spectra in any system where multiple species are present in a generally known volume.
Safar Cherati, Afsaneh; Lotfian, Sara; Jamshidi, Aliashraf; Sanjari, Mohammad Ali; Razi, Mohammad
2016-09-01
The effects of exercise volume on the pattern of muscle activity is one of the most important factors in training management and injury risk reduction. In the lower limb, the quadriceps muscle which plays a determining role in performing the stance and other karate techniques could be injured in intensive exercise and may induce anterior knee pain in athletes. The aim of this study was to determine the relationship between training volume and muscle activity of vastus medialis and vastus lateralis and its association with anterior knee pain in karate elites. Male and female athletes from national junior and cadet karate team (14 to 18 years) were invited to participate in the study at the beginning and the end of the training camps. Studies involved measurement of electromyographic muscle activity of vastus medialis and vastus lateralis in both lower extremities with surface electromyography device and assessment of movement by electrogoniometery. Muscle activity was recorded in three tests of dachi, walking up and walking down stairs. Simultaneously, anterior knee pain was evaluated using visual analogue scale and anterior knee pain scale questionnaire. Eight athletes of a total number of 23 reported increased ratings of pain in their right knees. No differences in muscle activity were observed in tests of Dachi and stairs between the groups with and without pain. Comparing Dachi task pattern at the beginning and end of training camps, there was no significant difference in pattern of biomechanical movement; however, reducing the amount of muscle activity in early and late phases of tasks was observed in electromyographic assessment. The results showed that performing the same task after a six-week training period, less muscle activity was required in all phases in two groups of tasks, including karate-specific movement (dachi) and activities of daily living (up or down stairs).
Jégat , Alain
2014-01-01
The usual framework for Einstein’s special theory of relativity is the pseudo-euclidean spacetime proposed by Hermann Minkowski. This article aims at proposing a different model.The framework is an euclidean four-dimensional space in which all the objects move regularly (it means that, between two observations, whatever their trajectories, they cover the same distance), but where the events are seen in projection according to a privileged direction, as we are going to explain. The remark, rat...
Zachary, Chase E; Jiao, Yang; Torquato, Salvatore
2011-05-01
Hyperuniform many-particle distributions possess a local number variance that grows more slowly than the volume of an observation window, implying that the local density is effectively homogeneous beyond a few characteristic length scales. Previous work on maximally random strictly jammed sphere packings in three dimensions has shown that these systems are hyperuniform and possess unusual quasi-long-range pair correlations decaying as r(-4), resulting in anomalous logarithmic growth in the number variance. However, recent work on maximally random jammed sphere packings with a size distribution has suggested that such quasi-long-range correlations and hyperuniformity are not universal among jammed hard-particle systems. In this paper, we show that such systems are indeed hyperuniform with signature quasi-long-range correlations by characterizing the more general local-volume-fraction fluctuations. We argue that the regularity of the void space induced by the constraints of saturation and strict jamming overcomes the local inhomogeneity of the disk centers to induce hyperuniformity in the medium with a linear small-wave-number nonanalytic behavior in the spectral density, resulting in quasi-long-range spatial correlations scaling with r(-(d+1)) in d Euclidean space dimensions. A numerical and analytical analysis of the pore-size distribution for a binary maximally random jammed system in addition to a local characterization of the n-particle loops governing the void space surrounding the inclusions is presented in support of our argument. This paper is the first part of a series of two papers considering the relationships among hyperuniformity, jamming, and regularity of the void space in hard-particle packings.
Directory of Open Access Journals (Sweden)
Rajagopalan P
2016-09-01
Full Text Available Prashanth Rajagopalan,1 Georgi Abraham,2 Yuvaram NV Reddy,2 Ravivarman Lakshmanasami,1 ML Prakash,1 Yogesh NV Reddy2 1Department of General Medicine, Mahatma Gandhi Medical College and Research Institute, Puducherry, 2Department of Nephrology, Madras Medical Mission Hospital, Chennai, India Abstract: This population-based prospective study was undertaken in Mahatma Gandhi Medical College to estimate the renal function in young healthy Indian adults. A young healthy heterogeneous Indian cohort comprising 978 individuals, predominantly medical students, was assessed by a detailed questionnaire, and variables such as height, weight, body mass index (BMI, birth weight, and blood pressure were documented. Laboratory investigations included serum creatinine, serum cystatin C, blood sugar, urine protein, and imaging of the kidneys with ultrasound. The mean age of the cohort was 25±6 years, comprising 672 males and 306 females. The estimated glomerular filtration rates (eGFRs by the Cockcroft–Gault formula for BMI <18.5 kg/m2, 18.5–24.99 kg/m2, 25–29.99 kg/m2, and ≥30 kg/m2 were 71.29±10.45 mL/min, 86.38±13.46 mL/min, 98.88±15.29 mL/min, and 109.13±21.57 mL/min, respectively; the eGFRs using cystatin C for the four groups of BMI were 84.53±18.14 mL/min, 84.01±40.11 mL/min, 79.18±13.46 mL/min, and 77.30±10.90 mL/min, respectively. This study attempts to establish a normal range of serum creatinine and cystatin C values for the Indian population and shows that in young healthy Indian adults, eGFR and kidney volume vary by BMI and sex. Keywords: eGFR, birth weight, renal volume
Energy Technology Data Exchange (ETDEWEB)
Miller, Karen A., E-mail: kamiller@lanl.gov [Los Alamos National Laboratory, Los Alamos, P.O. Box 1663 MS E540, NM 87545 (United States); Menlove, Howard O.; Swinhoe, Martyn T.; Marlow, Johnna B. [Los Alamos National Laboratory, Los Alamos, P.O. Box 1663 MS E540, NM 87545 (United States)
2013-03-01
Uranium cylinder assay plays an important role in the nuclear material accounting at gas centrifuge enrichment plants. The Passive Neutron Enrichment Meter (PNEM) was designed to determine uranium mass and enrichment in 30B and 48Y cylinders using total neutron and coincidence counting in the passive mode. 30B and 48Y cylinders are used to hold bulk UF{sub 6} feed, product, and tails at enrichment plants. In this paper, we report the results of a Monte-Carlo-based feasibility study for an active uranium cylinder assay system based on the PNEM design. There are many advantages of the active technique such as a shortened count time and a more direct measure of {sup 235}U content. The active system is based on a modified PNEM design and uses a {sup 252}Cf source as the correlated, active interrogation source. We show through comparison with a random AmLi source of equal strength how the use of a correlated driver significantly boosts the active signal and reduces the statistical uncertainty. We also discuss ways in which an active uranium cylinder assay system can be optimized to minimize background from {sup 238}U fast-neutron induced fission and direct counts from the interrogation source.
Directory of Open Access Journals (Sweden)
D. A. Granov
2014-01-01
Full Text Available Aim: optimization of the surgical treatment policy with orthotopic liver transplantation (OLT depending on the results of intraoperative fl owmetry and the state of intrahepatic microcirculatory bloodstream according to immunohistochemical (IHC study of microspecimens of the donor’s liver.Materials and methods. 60 patients are included in the study. Group I (n = 30 comprised of patients for whom it was not necessary to perform any additional interventions on the bloodstream in the hepatopancreatobiliary area during OLT. Group II (n = 30 had patients with insuffi cient arterial blood supply for the graft in the intraoperative stage where it was needed to perform additional and/or repeated interventions in the arteries of the hepatopancreatobilliary area. Intraoperative fl owmetry with assessment of the volume blood circulation (VBC in the hepatic artery (HA was carried out in the both studied groups. Reference value of VBC was 100 ml/min and higher. Before and after reperfusion in the liver biopsy material we performed immunohistochemical study with the use of endothelial marker CD 31 with subsequent morphometric estimation of the specifi c square of the microvascular bloodstream.Results. In both groups there was no change in the specifi c square in the areas of portal tract and central vein before and after restoring blood fl ow. In the second group, an 8 times increase of the specifi c square of sinusoids was observed after restoring blood fl ow (р < 0,01.Conclusion. Intraoperative fl owmetric control of the blood fl ow allows in due time to perform surgical correction of the graft arterial blood supply during OLT, and it reduces the risk of thrombosis up to 0%. The value of VBC in the hepatic artery (HA has reliable dependence upon the state of microcirculatory bloodstream of cadaveric donor’s liver after reperfusion.
Mantus, M.; Pardo, H.
1973-01-01
Computer programming, data processing, and a correlation study that employed data collected in the first phase test were used to demonstrate that standard test procedures and equipment could be used to collect a significant number of transfer functions from tests of the Lunar Module test article LTA-11. The testing consisted of suspending the vehicle from the apex fittings of the outrigger trusses through a set of air springs to simulate the free-free state. Impulsive loadings were delivered, one at a time, at each of the landing gear's attachment points, in three mutually perpendicular directions; thus a total of 36 impulses were applied to the vehicle. Time histories of each pulse were recorded on magnetic tape along with 40 channels of strain gage response and 28 channels of accelerometer response. Since an automated data processing system was not available, oscillograph playbacks were made of all 2400 time histories as a check on the validity of the data taken. In addition, one channel of instrumentation was processed to determine its response to a set of forcing functions from a prior LTA-11 drop test. This prediction was compared with drop test results as a first measure of accuracy.
Li, Xiao-Dong; Park, Changbom; Sabiu, Cristiano G.; Park, Hyunbae; Cheng, Cheng; Kim, Juhan; Hong, Sungwook E.
2017-08-01
We develop a methodology to use the redshift dependence of the galaxy 2-point correlation function (2pCF) across the line of sight, ξ ({r}\\perp ), as a probe of cosmological parameters. The positions of galaxies in comoving Cartesian space varies under different cosmological parameter choices, inducing a redshift-dependent scaling in the galaxy distribution. This geometrical distortion can be observed as a redshift-dependent rescaling in the measured ξ ({r}\\perp ). We test this methodology using a sample of 1.75 billion mock galaxies at redshifts 0, 0.5, 1, 1.5, and 2, drawn from the Horizon Run 4 N-body simulation. The shape of ξ ({r}\\perp ) can exhibit a significant redshift evolution when the galaxy sample is analyzed under a cosmology differing from the true, simulated one. Other contributions, including the gravitational growth of structure, galaxy bias, and the redshift space distortions, do not produce large redshift evolution in the shape. We show that one can make use of this geometrical distortion to constrain the values of cosmological parameters governing the expansion history of the universe. This method could be applicable to future large-scale structure surveys, especially photometric surveys such as DES and LSST, to derive tight cosmological constraints. This work is a continuation of our previous works as a strategy to constrain cosmological parameters using redshift-invariant physical quantities.
Mains, Jill Rachel; Donskov, Frede; Pedersen, Erik Morre; Madsen, Hans Henrik Torp; Rasmussen, Finn
2017-02-01
The aim was to explore the potential for using dynamic contrast-enhanced computed tomography as a noninvasive functional imaging biomarker before and during the early treatment of metastatic renal cell carcinoma (mRCC). Dynamic contrast-enhanced computed tomography scans were performed at baseline and after 5 and 10 weeks' treatment in 69 prospectively included mRCC patients receiving treatment with interferon alpha and interleukin 2 (n = 26); interferon alpha, interleukin 2, and bevacizumab (n = 24); sunitinib (n = 7); pazopanib (n = 5); or temsirolimus (n = 7). Using a prototype software program (Advanced Perfusion and Permeability Application, Philips Healthcare, Best, the Netherlands), blood volume (BV), blood flow (BF), and permeability surface area product (PS) were calculated for each tumor at baseline, week 5, and week 10. These parameters as well as relative changes between baseline and weeks 5 and 10 were tested for associations with progression-free survival (PFS) and overall survival (OS) using Kaplan-Meier curves and log-rank tests. Using the 25th percentile as the cutoff, baseline BV for all patients independent of subsequent treatment was statistically significantly associated with PFS (10.8 vs 5.3 months, P = 0.007) and OS (35.2 vs 13.3 months, P = 0.001), and baseline BF was significantly associated with OS (31.7 vs 14.6 months, P = 0.024) with high values for both parameters being associated with significantly longer PFS and OS. Baseline PS was not associated with PFS or OS.In patients treated with angiogenesis inhibitors (bevacizumab, sunitinib, pazopanib, or temsirolimus), the relative change in BV from baseline to week 5 using 25th percentile as the cutoff was associated with PFS (5.6 vs 24.8 months, P = 0.001) and OS (19.1 months vs not reached, P = 0.008) and from baseline to week 10 with PFS (8.1 vs 16.4 months, P = 0.014) and OS (15.5 months vs not reached, P = 0.002). The relative change in BF from baseline to week 5 using medians as the
Energy Technology Data Exchange (ETDEWEB)
Lemarignier, Charles; Groheux, David [Saint-Louis Hospital, Assistance Publique - Hopitaux de Paris, Department of Nuclear Medicine, Paris (France); University Sorbonne Paris Cite, INSERM/CNRS UMR944/7212, Paris (France); Martineau, Antoine; Vercellino, Laetitia; Merlet, Pascal [Saint-Louis Hospital, Assistance Publique - Hopitaux de Paris, Department of Nuclear Medicine, Paris (France); Teixeira, Luis; Espie, Marc [Saint-Louis Hospital, Breast Diseases Unit, Paris (France); University Sorbonne Paris Cite, INSERM/CNRS UMR944/7212, Paris (France)
2017-07-15
The study was designed to evaluate 1) the relationship between PET image textural features (TFs) and SUVs, metabolic tumour volume (MTV), total lesion glycolysis (TLG) and tumour characteristics in a large prospective and homogenous cohort of oestrogen receptor-positive (ER+) breast cancer (BC) patients, and 2) the capability of those parameters to predict response to neoadjuvant chemotherapy (NAC). 171 consecutive patients with large or locally advanced ER+ BC without distant metastases underwent an {sup 18}F-FDG PET examination before NAC. The primary tumour was delineated with an adaptive threshold segmentation method. Parameters of volume, intensity and texture (entropy, homogeneity, contrast and energy) were measured and compared with tumour characteristics determined on pre-treatment breast biopsy (Wilcoxon rank-sum test). The correlation between PET-derived parameters was determined using Spearman's coefficient. The relationship between PET features and pathological findings was determined using the Wilcoxon rank-sum test. Spearman's coefficients between SUV{sub max} and TFs were 0.43, 0.24, -0.43 and -0.15 respectively for entropy, homogeneity, energy and contrast; they were higher between MTV and TFs: 0.99, 0.86, -0.99 and -0.87. All TFs showed a significant association with the histological type (IDC vs. ILC; 0.02 < P < 0.03) but didn't with immunohistochemical characteristics. SUV{sub max} and TLG predicted the pathological response (P = 0.0021 and P = 0.02 respectively); TFs didn't (P: 0.27, 0.19, 0.94, 0.19 respectively for entropy, homogeneity, energy and contrast). The correlation of TFs was poor with SUV parameters and high with MTV. TFs showed a significant association with the histological type. Finally, while SUV{sub max} and TLG were able to predict response to NAC, TFs failed. (orig.)
Lemarignier, Charles; Martineau, Antoine; Teixeira, Luis; Vercellino, Laetitia; Espié, Marc; Merlet, Pascal; Groheux, David
2017-07-01
The study was designed to evaluate 1) the relationship between PET image textural features (TFs) and SUVs, metabolic tumour volume (MTV), total lesion glycolysis (TLG) and tumour characteristics in a large prospective and homogenous cohort of oestrogen receptor-positive (ER+) breast cancer (BC) patients, and 2) the capability of those parameters to predict response to neoadjuvant chemotherapy (NAC). 171 consecutive patients with large or locally advanced ER+ BC without distant metastases underwent an 18 F-FDG PET examination before NAC. The primary tumour was delineated with an adaptive threshold segmentation method. Parameters of volume, intensity and texture (entropy, homogeneity, contrast and energy) were measured and compared with tumour characteristics determined on pre-treatment breast biopsy (Wilcoxon rank-sum test). The correlation between PET-derived parameters was determined using Spearman's coefficient. The relationship between PET features and pathological findings was determined using the Wilcoxon rank-sum test. Spearman's coefficients between SUV max and TFs were 0.43, 0.24, -0.43 and -0.15 respectively for entropy, homogeneity, energy and contrast; they were higher between MTV and TFs: 0.99, 0.86, -0.99 and -0.87. All TFs showed a significant association with the histological type (IDC vs. ILC; 0.02 < P < 0.03) but didn't with immunohistochemical characteristics. SUV max and TLG predicted the pathological response (P = 0.0021 and P = 0.02 respectively); TFs didn't (P: 0.27, 0.19, 0.94, 0.19 respectively for entropy, homogeneity, energy and contrast). The correlation of TFs was poor with SUV parameters and high with MTV. TFs showed a significant association with the histological type. Finally, while SUV max and TLG were able to predict response to NAC, TFs failed.
Auction dynamics: A volume constrained MBO scheme
Jacobs, Matt; Merkurjev, Ekaterina; Esedoǧlu, Selim
2018-02-01
We show how auction algorithms, originally developed for the assignment problem, can be utilized in Merriman, Bence, and Osher's threshold dynamics scheme to simulate multi-phase motion by mean curvature in the presence of equality and inequality volume constraints on the individual phases. The resulting algorithms are highly efficient and robust, and can be used in simulations ranging from minimal partition problems in Euclidean space to semi-supervised machine learning via clustering on graphs. In the case of the latter application, numerous experimental results on benchmark machine learning datasets show that our approach exceeds the performance of current state-of-the-art methods, while requiring a fraction of the computation time.
International Nuclear Information System (INIS)
Yaparpalvi, Ravindra; Hong, Linda; Mah, Dennis; Shen Jin; Mutyala, Subhakar; Spierer, Marnee; Garg, Madhur; Guha, Chandan; Kalnicki, Shalom
2008-01-01
Background and Purpose: IMRT clinical trials lack dose prescription and specification standards similar to ICRU standards for two- and three-dimensional external beam planning. In this study, we analyzed dose distributions for patients whose treatment plans incorporated IMRT, and compared the dose determined at the ICRU reference point to the PTV doses determined from dose-volume histograms. Additionally, we evaluated if ICRU reference type single-point dose prescriptions are suitable for IMRT dose prescriptions. Materials and methods: For this study, IMRT plans of 117 patients treated at our institution were randomly selected and analyzed. The treatment plans were clinically applied to the following disease sites: abdominal (11), anal (10), brain (11), gynecological (15), head and neck (25), lung (15), male pelvis (10) and prostate (20). The ICRU reference point was located in each treatment plan following ICRU Report 50 guidelines. The reference point was placed in the central part of the PTV and at or near the isocenter. In each case, the dose was calculated and recorded to this point. For each patient - volume and dose (PTV, PTV mean, median and modal) information was extracted from the planned dose-volume histogram. Results: The ICRU reference dose vs PTV mean dose relationship in IMRT exhibited a weak positive association (Pearson correlation coefficient 0.63). In approximately 65% of the cases studied, dose at the ICRU reference point was greater than the corresponding PTV mean dose. The dose difference between ICRU reference and PTV mean doses was ≤2% in approximately 79% of the cases studied (average 1.21% (±1.55), range -4% to +4%). Paired t-test analyses showed that the ICRU reference doses and PTV median doses were statistically similar (p = 0.42). The magnitude of PTV did not influence the difference between ICRU reference and PTV mean doses. Conclusions: The general relationship between ICRU reference and PTV mean doses in IMRT is similar to that
Directory of Open Access Journals (Sweden)
Stamataki S. K.
2006-11-01
Full Text Available The capabilities of cubic Equations of State (EoS in the correlation and the prediction of phase equilibria at hyperbaric conditions is examined. PVT data of pure compounds as well as VLE and volumetric data of binary mixtures up to 2000 bar are used. Correlation and prediction results are presented with the translated and modified Peng-Robinson (t - mPR EoS and EoS/GE models. The performance of cubic EoS with a single interaction parameter (kij in describing VLE is remarkable considering the level of pressures involved. The same is valid for the PVT results including the relative liquid volumes of the C1/nC24 system. With typical errors of about 10% deviations in pressure of 100 - 200 bar are, of course, encountered which can be eliminated by the use of second interaction coefficient in the covolume combining rule. Predicted kij values obtained from generalized correlations developed from low pressure VLE data provide reasonable results for systems with hydrocarbons up to nC16 even at high pressures, but fail for higher asymmetric ones. Volume translation is essential for PVT predictions. The temperature independent translation of t - mPR and that of Jhaveri and Yougren give very satisfactory results. LCVM provides the best results of the EoS/GE models studied and gives very good predictions for rather symmetric systems which become poorer with asymmetric ones at very high pressures. La capacité des équations d'état (EoS cubiques pour corréler et prédire les équilibres de phases en conditions hyperbares est analysée. Les données PVT de corps purs ainsi que les données d'équilibres liquide-vapeur (VLE et volumétriques pour des mélanges binaires, jusqu'à 2000 bar sont utilisées. Les résultats des corrélations et des prédictions sont présentés pour l'équation de Peng-Robinson translatée et modifiée (t - mPR, ainsi que pour les modèles EoS/GE. Les performances des EoS cubiques avec un paramètre d'interaction unique (kij pour
D.M.K.S. Kaulesar Sukul (D. M K S); P.Th. den Hoed (Pieter); T. Johannes (Tanja); R. van Dolder (R.); E. Benda (Eric)
1993-01-01
textabstractVolume changes can be measured either directly by water-displacement volumetry or by various indirect methods in which calculation of the volume is based on circumference measurements. The aim of the present study was to determine the most appropriate indirect method for lower leg volume
Energy Technology Data Exchange (ETDEWEB)
Okada, Tomiro (Okayama Univ. (Japan). School of Medicine)
1993-06-01
Left ventricular (LV) diastolic functions in 23 patients with aortic regurgitation (AR) and 22 patients with mitral regurgitation (MR) were evaluated by gated blood pool scintigraphy. LV myocardial biopsy was performed during open heart surgery, and LV myocardial ultrastructural changes were evaluated by electron microscope. Correlation between LV diastolic function and myocardial ultrastructural changes was examined. It was suggested that preoperative LV diastolic dysfunction occurred earlier than LV systolic dysfunction in patients with AR and MR. LV early diastolic dysfunction was especially significant in patients with AR. LV systolic function was significantly improved postoperatively compared with LV diastolic function in patients with AR and MR. It was suggested that LV interstitial fibrosis caused LV diastolic dysfunction in patients with AR and MR, and insufficiency of myocardial thickening as compensation in patients with MR. It was presumed that LV diastolic dysfunction was irreversible in patients with AR and MR in the distant postoperative period due to persistence of the preoperative myocardial ultrastructural change, e.g., interstitial fibrosis. These LV diastolic indices measured by gated pool scintigraphy were useful in predicting LV ultrastructural changes and postoperative LV dysfunction in patients with LV volume-overloaded valvular heart disease. (author).
Kazanis, Ilias; Ffrench-Constant, Charles
2012-05-01
The mammalian subependymal zone (SEZ; often called subventricular) situated at the lateral walls of the lateral ventricles of the brain contains a pool of relatively quiescent adult neural stem cells whose neurogenic activity persists throughout life. These stem cells are positioned in close proximity both to the ependymal cells that provide the cerebrospinal fluid interface and to the blood vessel endothelial cells, but the relative contribution of these 2 cell types to stem cell regulation remains undetermined. Here, we address this question by analyzing a naturally occurring example of volumetric scaling of the SEZ in a comparison of the mouse SEZ with the larger rat SEZ. Our analysis reveals that the number of stem cells in the SEZ niche is correlated with the number of ependymal cells rather than with the volume, thereby indicating the importance of ependymal-derived factors in the formation and function of the SEZ. The elucidation of the factors generated by ependymal cells that regulate stem cell numbers within the SEZ is, therefore, of importance for stem cell biology and regenerative neuroscience.
Zachary, Chase E; Jiao, Yang; Torquato, Salvatore
2011-05-01
We extend the results from the first part of this series of two papers by examining hyperuniformity in heterogeneous media composed of impenetrable anisotropic inclusions. Specifically, we consider maximally random jammed (MRJ) packings of hard ellipses and superdisks and show that these systems both possess vanishing infinite-wavelength local-volume-fraction fluctuations and quasi-long-range pair correlations scaling as r(-(d+1)) in d Euclidean dimensions. Our results suggest a strong generalization of a conjecture by Torquato and Stillinger [Phys. Rev. E 68, 041113 (2003)], namely, that all strictly jammed saturated packings of hard particles, including those with size and shape distributions, are hyperuniform with signature quasi-long-range correlations. We show that our arguments concerning the constrained distribution of the void space in MRJ packings directly extend to hard-ellipse and superdisk packings, thereby providing a direct structural explanation for the appearance of hyperuniformity and quasi-long-range correlations in these systems. Additionally, we examine general heterogeneous media with anisotropic inclusions and show unexpectedly that one can decorate a periodic point pattern to obtain a hard-particle system that is not hyperuniform with respect to local-volume-fraction fluctuations. This apparent discrepancy can also be rationalized by appealing to the irregular distribution of the void space arising from the anisotropic shapes of the particles. Our work suggests the intriguing possibility that the MRJ states of hard particles share certain universal features independent of the local properties of the packings, including the packing fraction and average contact number per particle.
International Nuclear Information System (INIS)
Capri, M.A.L.; Lemes, V.E.R.; Sobreiro, R.F.; Sorella, S.P.; Dudal, D.; Verschelde, H.; Gracey, J.A.
2006-01-01
The ghost condensate abc c b c c > is considered together with the gluon condensate μ 2 > in SU(2) Euclidean Yang-Mills theories quantized in the Landau gauge. The vacuum polarization ceases to be transverse due to the nonvanishing condensate abc c b c c >. The gluon propagator itself remains transverse. By polarization effects, this ghost condensate induces then a splitting in the gluon mass parameter, which is dynamically generated through μ 2 >. The obtained effective masses are real when μ 2 > is included in the analysis. In the absence of μ 2 >, the already known result that the ghost condensate induces effective tachyonic masses is recovered. At the one-loop level, we find that the effective diagonal mass becomes smaller than the off-diagonal one. This might serve as an indication for some kind of Abelian dominance in the Landau gauge, similar to what happens in the maximal Abelian gauge
International Nuclear Information System (INIS)
Kovarik, M.D.; Barnes, T.; Tennessee Univ., Knoxville, TN
1993-01-01
We describe a Monte Carlo simulation of a dynamical fermion problem in two spatial dimensions on an Intel iPSC/860 hypercube. The problem studied is the determination of the dispersion relation of a dynamical hole in the t-J model of the high temperature superconductors. Since this problem involves the motion of many fermions in more than one spatial dimensions, it is representative of the class of systems that suffer from the ''minus sign problem'' of dynamical fermions which has made Monte Carlo simulation very difficult. We demonstrate that for small values of the hole hopping parameter one can extract the entire hole dispersion relation using the GRW Monte Carlo algorithm, which is a simulation of the Euclidean time Schroedinger equation, and present results on 4 x 4 and 6 x 6 lattices. Generalization to physical hopping parameter values wig only require use of an improved trial wavefunction for importance sampling
Graphical calculus of volume, inverse volume and Hamiltonian operators in loop quantum gravity
Energy Technology Data Exchange (ETDEWEB)
Yang, Jinsong [Guizhou University, Department of Physics, Guiyang (China); Academia Sinica, Institute of Physics, Taipei (China); Ma, Yongge [Beijing Normal University, Department of Physics, Beijing (China)
2017-04-15
To adopt a practical method to calculate the action of geometrical operators on quantum states is a crucial task in loop quantum gravity. In this paper, the graphical calculus based on the original Brink graphical method is applied to loop quantum gravity along the line of previous work. The graphical method provides a very powerful technique for simplifying complicated calculations. The closed formula of the volume operator and the actions of the Euclidean Hamiltonian constraint operator and the so-called inverse volume operator on spin-network states with trivalent vertices are derived via the graphical method. By employing suitable and non-ambiguous graphs to represent the action of operators as well as the spin-network states, we use the simple rules of transforming graphs to obtain the resulting formula. Comparing with the complicated algebraic derivation in some literature, our procedure is more concise, intuitive and visual. The resulting matrix elements of the volume operator is compact and uniform, fitting for both gauge-invariant and gauge-variant spin-network states. Our results indicate some corrections to the existing results for the Hamiltonian operator and inverse volume operator in the literature. (orig.)
International Nuclear Information System (INIS)
Elias, V.; Univ. of Western Ontario, London, ON; Murison, J.L.; Scadron, M.D.; Steele, T.G.
1993-01-01
The dimension-3 quark-condensate component of the flavour-diagonal axial-vector two-current correlation function is evaluated to all orders in the quark mass m qk through use of the quark-condensate component of the nonperturbative fermion propagator. The result obtained is analytic in p 2 except for a branch cut for 0 2 qk ) 2 , corresponding to a branch cut occurring helow the anti qq kinematic threshold. The deep Euclidean region of the longitudinal component of this correlation function is utilized to obtain leading and subleading contributions to the QCD sum-rule relating m qk to . These same sum-rule results are obtained by means of an alternative derivation involving integration over the discontinuity in the correlation function along the branch cut, demonstrating the consistency of the physical-momentum-region branch cut with results obtained via standard means in the deep Euclidean region. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Drozdz, Sonia; Wendt, Thomas G. [University Hospital Jena, Friedrich-Schiller-University Jena, Department of Radiation Oncology, Jena (Germany); Schwedas, Michael; Salz, Henning [University Hospital Jena, Friedrich-Schiller-University Jena, Department of Radiation Oncology, Section of Medical Physics, Jena (Germany); Foller, Susan [University Hospital Jena, Friedrich-Schiller-University Jena, Department of Urology, Jena (Germany)
2016-04-15
We compared different image-guidance (IG) strategies for prostate cancer with high-precision IG intensity-modulated radiation therapy (IMRT) using TomoTherapy {sup registered} (Accuray Inc., Madison, WI, USA) and linear accelerator (LINAC)-IMRT and their impact on planning target volume (PTV) margin reduction. Follow-up data showed reduced bladder toxicity in TomoTherapy patients compared to LINAC-IMRT. The purpose of this study was to quantify whether the treatment delivery technique and decreased margins affect reductions in bladder toxicity. Setup corrections from 30 patients treated with helical TomoTherapy and 30 treated with a LINAC were analyzed. These data were used to simulate three IG protocols based on setup error correction and a limited number of imaging sessions. For all patients, gastrointestinal (GI) and genitourinary (GU) toxicity was documented and correlated with the treatment delivery technique. For fiducial marker (FM)-based RT, a margin reduction of up to 3.1, 3.0, and 4.8 mm in the left-right (LR), superior-inferior (SI), and anterior-posterior (AP) directions, respectively, could be achieved with calculation of a setup correction from the first three fractions and IG every second day. Although the bladder volume was treated with mean doses of 35 Gy in the TomoTherapy group vs. 22 Gy in the LINAC group, we observed less GU toxicity after TomoTherapy. Intraprostate FMs allow for small safety margins, help decrease imaging frequency after setup correction, and minimize the dose to bladder and rectum, resulting in lower GU toxicity. In addition, IMRT delivered with TomoTherapy helps to avoid hotspots in the bladder neck, a critical anatomic structure associated with post-RT urinary toxicity. (orig.) [German] Wir haben im Rahmen der Prostatakarzinombehandlung verschiedene bildgefuehrte (IG) Strategien der hochpraezisen intensitaetsmodulierten Radiotherapie (IMRT) unter Einsatz der Tomotherapie (TomoTherapy {sup registered}, Accuray Inc., Madison
International Nuclear Information System (INIS)
Capri, M. A. L.; Lemes, V. E. R.; Sobreiro, R. F.; Sorella, S. P.; Thibes, R.
2006-01-01
We pursue the study of SU(2) Euclidean Yang-Mills theory in the maximal Abelian gauge by taking into account the effects of the Gribov horizon. The Gribov approximation, previously introduced in [M. A. L. Capri, V. E. R. Lemes, R. F. Sobreiro, S. P. Sorella, and R. Thibes, Phys. Rev. D 72, 085021 (2005).], is improved through the introduction of the horizon function, which is constructed under the requirements of localizability and renormalizability. By following Zwanziger's treatment of the horizon function in the Landau gauge, we prove that, when cast in local form, the horizon term of the maximal Abelian gauge leads to a quantized theory which enjoys multiplicative renormalizability, a feature which is established to all orders by means of the algebraic renormalization. Furthermore, it turns out that the horizon term is compatible with the local residual U(1) Ward identity, typical of the maximal Abelian gauge, which is easily derived. As a consequence, the nonrenormalization theorem, Z g Z A 1/2 =1, relating the renormalization factors of the gauge coupling constant Z g and of the diagonal gluon field Z A , still holds in the presence of the Gribov horizon. Finally, we notice that a generalized dimension two gluon operator can be also introduced. It is BRST invariant on-shell, a property which ensures its multiplicative renormalizability. Its anomalous dimension is not an independent parameter of the theory, being obtained from the renormalization factors of the gauge coupling constant and of the diagonal antighost field
Osseiran, Sam; Roider, Elisabeth M.; Wang, Hequn; Suita, Yusuke; Murphy, Michael; Fisher, David E.; Evans, Conor L.
2017-12-01
Chemical sun filters are commonly used as active ingredients in sunscreens due to their efficient absorption of ultraviolet (UV) radiation. Yet, it is known that these compounds can photochemically react with UV light and generate reactive oxygen species and oxidative stress in vitro, though this has yet to be validated in vivo. One label-free approach to probe oxidative stress is to measure and compare the relative endogenous fluorescence generated by cellular coenzymes nicotinamide adenine dinucleotides and flavin adenine dinucleotides. However, chemical sun filters are fluorescent, with emissive properties that contaminate endogenous fluorescent signals. To accurately distinguish the source of fluorescence in ex vivo skin samples treated with chemical sun filters, fluorescence lifetime imaging microscopy data were processed on a pixel-by-pixel basis using a non-Euclidean separation algorithm based on Mahalanobis distance and validated on simulated data. Applying this method, ex vivo samples exhibited a small oxidative shift when exposed to sun filters alone, though this shift was much smaller than that imparted by UV irradiation. Given the need for investigative tools to further study the clinical impact of chemical sun filters in patients, the reported methodology may be applied to visualize chemical sun filters and measure oxidative stress in patients' skin.
Directory of Open Access Journals (Sweden)
Rodríguez Velásquez, Javier Oswaldo
2014-01-01
Full Text Available Background: Pathological interpretation of cellular form in cervical cytology is very important for preven- tion of cervical cancer. The methods most frequently used for assessment of this test have reproducibility and inter-observer variability problems. Objective: To make fractal and Euclidean measure- ments to mathematically diagnose normal and pre- malignant cells of cervical squamous epithelium. Methodology: 21 cells with normal, ASCUS or LSIL diagnosis according to the Bethesda system were assessed. Fractal and Euclidean geometric measures of three mathematical objects were calculated: cyto- plasm, nucleus and whole cell. Mathematical propor- tions between these measurements were calculated in order to compare them with conventional classification methods. Results: It was found that the nuclear border measures calculated with the 2-pixel grill and the surface measures could mathematically and objectively differentiate normal cells from the pre-malignant ones (ASCUS and LSIL. Conclusions: An objective and reproducible diagnos- tic method was developed; it allows to identify the evolution towards malignant cellular states based on simultaneous fractal and Euclidean measures, estab- lishing the severity level of ASCUS and LSIL cells.
International Nuclear Information System (INIS)
Giraud, B.G.; Heumann, J.M.; Lapedes, A.S.
1999-01-01
The fact that correlation does not imply causation is well known. Correlation between variables at two sites does not imply that the two sites directly interact, because, e.g., correlation between distant sites may be induced by chaining of correlation between a set of intervening, directly interacting sites. Such 'noncausal correlation' is well understood in statistical physics: an example is long-range order in spin systems, where spins which have only short-range direct interactions, e.g., the Ising model, display correlation at a distance. It is less well recognized that such long-range 'noncausal' correlations can in fact be stronger than the magnitude of any causal correlation induced by direct interactions. We call this phenomenon superadditive correlation (SAC). We demonstrate this counterintuitive phenomenon by explicit examples in (i) a model spin system and (ii) a model continuous variable system, where both models are such that two variables have multiple intervening pathways of indirect interaction. We apply the technique known as decimation to explain SAC as an additive, constructive interference phenomenon between the multiple pathways of indirect interaction. We also explain the effect using a definition of the collective mode describing the intervening spin variables. Finally, we show that the SAC effect is mirrored in information theory, and is true for mutual information measures in addition to correlation measures. Generic complex systems typically exhibit multiple pathways of indirect interaction, making SAC a potentially widespread phenomenon. This affects, e.g., attempts to deduce interactions by examination of correlations, as well as, e.g., hierarchical approximation methods for multivariate probability distributions, which introduce parameters based on successive orders of correlation. copyright 1999 The American Physical Society
International Nuclear Information System (INIS)
Ishiyama, Hiromichi; Kitano, Masashi; Satoh, Takefumi; Kotani, Shouko; Uemae, Mineko; Matsumoto, Kazumasa; Okusa, Hiroshi; Tabata, Ken-ichi; Baba, Shiro; Hayakawa, Kazushige
2009-01-01
Purpose: To evaluate the severity of genitourinary (GU) toxicity in high-dose-rate (HDR) brachytherapy combined with hypofractionated external beam radiotherapy (EBRT) for prostate cancer and to explore factors that might affect the severity of GU toxicity. Methods and Materials: A total of 100 Japanese men with prostate cancer underwent 192 Ir HDR brachytherapy combined with hypofractionated EBRT. Mean (SD) dose to 90% of the planning target volume was 6.3 (0.7) Gy per fraction of HDR. After 5 fractions of HDR treatment, EBRT with 10 fractions of 3 Gy was administrated. The urethral volume receiving 1-15 Gy per fraction in HDR brachytherapy (V1-V15) and the dose to at least 5-100% of urethral volume in HDR brachytherapy (D5-D100) were compared between patients with Grade 3 toxicity and those with Grade 0-2 toxicity. Prostate volume, patient age, and International Prostate Symptom Score were also compared between the two groups. Results: Of the 100 patients, 6 displayed Grade 3 acute GU toxicity, and 12 displayed Grade 3 late GU toxicity. Regarding acute GU toxicity, values of V1, V2, V3, and V4 were significantly higher in patients with Grade 3 toxicity than in those with Grade 0-2 toxicity. Regarding late GU toxicity, values of D70, D80, V12, and V13 were significantly higher in patients with Grade 3 toxicity than in those with Grade 0-2 toxicity. Conclusions: The severity of GU toxicity in HDR brachytherapy combined with hypofractionated EBRT for prostate cancer was relatively high. The volume of prostatic urethra was associated with grade of acute GU toxicity, and urethral dose was associated with grade of late GU toxicity.
Directory of Open Access Journals (Sweden)
DanFang Yan
Full Text Available OBJECTS: To introduce a new method for generating the clinical target volume (CTV from gross tumor volume (GTV using the geodesic distance calculation for glioma. METHODS: One glioblastoma patient was enrolled. The GTV and natural barriers were contoured on each slice of the computer tomography (CT simulation images. Then, a graphic processing unit based on a parallel Euclidean distance transform was used to generate the CTV considering natural barriers. Three-dimensional (3D visualization technique was applied to show the delineation results. Speed of operation and precision were compared between this new delineation method and the traditional method. RESULTS: In considering spatial barriers, the shortest distance from the point sheltered from these barriers equals the sum of the distance along the shortest path between the two points; this consists of several segments and evades the spatial barriers, rather than being the direct Euclidean distance between two points. The CTV was generated irregularly rather than as a spherical shape. The time required to generate the CTV was greatly reduced. Moreover, this new method improved inter- and intra-observer variability in defining the CTV. CONCLUSIONS: Compared with the traditional CTV delineation, this new method using geodesic distance calculation not only greatly shortens the time to modify the CTV, but also has better reproducibility.
Jeazet, Harold B Tanh; Koschine, Tönjes; Staudt, Claudia; Raetzke, Klaus; Janiak, Christoph
2013-10-25
Hydrothermally stable particles of the metal-organic framework MIL-101(Cr) were incorporated into a polysulfone (PSF) matrix to produce mixed-matrix or composite membranes with excellent dispersion of MIL-101 particles and good adhesion within the polymer matrix. Pure gas (O2, N2, CO2 and CH4) permeation tests showed a significant increase of gas permeabilities of the mixed-matrix membranes without any loss in selectivity. Positron annihilation lifetime spectroscopy (PALS) indicated that the increased gas permeability is due to the free volume in the PSF polymer and the added large free volume inside the MIL-101 particles. The trend of the gas transport properties of the composite membranes could be reproduced by a Maxwell model.
Jeazet, Harold B. Tanh; Koschine, Tönjes; Staudt, Claudia; Raetzke, Klaus; Janiak, Christoph
2013-01-01
Hydrothermally stable particles of the metal-organic framework MIL-101(Cr) were incorporated into a polysulfone (PSF) matrix to produce mixed-matrix or composite membranes with excellent dispersion of MIL-101 particles and good adhesion within the polymer matrix. Pure gas (O2, N2, CO2 and CH4) permeation tests showed a significant increase of gas permeabilities of the mixed-matrix membranes without any loss in selectivity. Positron annihilation lifetime spectroscopy (PALS) indicated that the increased gas permeability is due to the free volume in the PSF polymer and the added large free volume inside the MIL-101 particles. The trend of the gas transport properties of the composite membranes could be reproduced by a Maxwell model. PMID:24957061
Topological methods in Euclidean spaces
Naber, Gregory L
2000-01-01
Extensive development of a number of topics central to topology, including elementary combinatorial techniques, Sperner's Lemma, the Brouwer Fixed Point Theorem, homotopy theory and the fundamental group, simplicial homology theory, the Hopf Trace Theorem, the Lefschetz Fixed Point Theorem, the Stone-Weierstrass Theorem, and Morse functions. Includes new section of solutions to selected problems.
Euclidean distance geometry an introduction
Liberti, Leo
2017-01-01
This textbook, the first of its kind, presents the fundamentals of distance geometry: theory, useful methodologies for obtaining solutions, and real world applications. Concise proofs are given and step-by-step algorithms for solving fundamental problems efficiently and precisely are presented in Mathematica®, enabling the reader to experiment with concepts and methods as they are introduced. Descriptive graphics, examples, and problems, accompany the real gems of the text, namely the applications in visualization of graphs, localization of sensor networks, protein conformation from distance data, clock synchronization protocols, robotics, and control of unmanned underwater vehicles, to name several. Aimed at intermediate undergraduates, beginning graduate students, researchers, and practitioners, the reader with a basic knowledge of linear algebra will gain an understanding of the basic theories of distance geometry and why they work in real life.
Non-Euclidean visibility problems
Indian Academy of Sciences (India)
FERNANDO CHAMIZO. Departamento de Matemáticas, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain. MS received 14 November 2005. Abstract. We consider the analog of visibility problems in hyperbolic plane (repre- sented by Poincaré half-plane model H), replacing the standard lattice Z ...
2016-01-01
Purpose/Objective(s) We sought to identify swallowing muscle dose-response thresholds associated with chronic radiation-associated dysphagia (RAD) after IMRT for oropharyngeal cancer. Materials/Methods T1-4 N0-3 M0 oropharyngeal cancer patients who received definitive IMRT and systemic therapy were examined. Chronic RAD was coded as any of the following ≥ 12 months post-IMRT: videofluoroscopy/endoscopy detected aspiration or stricture, gastrostomy tube and/or aspiration pneumonia. DICOM-RT plan data were autosegmented using a custom region-of-interest (ROI) library and included inferior, middle and superior constrictors (IPC, MPC, and SPC), medial and lateral pterygoids (MPM, LPM), anterior and posterior digastrics (ADM, PDM), intrinsic tongue muscles (ITM), mylo/geniohyoid complex (MHM), genioglossus (GGM), ), masseter (MM), Buccinator (BM), palatoglossus (PGM), and cricopharyngeus (CPM), with ROI dose-volume histograms (DVHs) calculated. Recursive partitioning analysis (RPA) was used to identify dose-volume effects associated with chronic-RAD, for use in a multivariate (MV) model. Results Of 300 patients, 34 (11%) had chronic-RAD. RPA showed DVH-derived MHM V69 (i.e. the volume receiving ≥69Gy), GGM V35, ADM V60, MPC V49, and SPC V70 were associated with chronic-RAD. A model including age in addition to MHM V69 as continuous variables was optimal among tested MV models (AUC 0.835). Conclusion In addition to SPCs, dose to MHM should be monitored and constrained, especially in older patients (>62-years), when feasible. PMID:26897515
2016-02-01
We sought to identify swallowing muscle dose-response thresholds associated with chronic radiation-associated dysphagia (RAD) after IMRT for oropharyngeal cancer. T1-4 N0-3 M0 oropharyngeal cancer patients who received definitive IMRT and systemic therapy were examined. Chronic RAD was coded as any of the following ⩾12months post-IMRT: videofluoroscopy/endoscopy detected aspiration or stricture, gastrostomy tube and/or aspiration pneumonia. DICOM-RT plan data were autosegmented using a custom region-of-interest (ROI) library and included inferior, middle and superior constrictors (IPC, MPC, and SPC), medial and lateral pterygoids (MPM, LPM), anterior and posterior digastrics (ADM, PDM), intrinsic tongue muscles (ITM), mylo/geniohyoid complex (MHM), genioglossus (GGM), masseter (MM), buccinator (BM), palatoglossus (PGM), and cricopharyngeus (CPM), with ROI dose-volume histograms (DVHs) calculated. Recursive partitioning analysis (RPA) was used to identify dose-volume effects associated with chronic-RAD, for use in a multivariate (MV) model. Of 300 patients, 34 (11%) had chronic-RAD. RPA showed DVH-derived MHM V69 (i.e. the volume receiving⩾69Gy), GGM V35, ADM V60, MPC V49, and SPC V70 were associated with chronic-RAD. A model including age in addition to MHM V69 as continuous variables was optimal among tested MV models (AUC 0.835). In addition to SPCs, dose to MHM should be monitored and constrained, especially in older patients (>62-years), when feasible. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Scintigraphic And Ultrasonic Determinations of Thyroid Volume
International Nuclear Information System (INIS)
Sarsono; Ismanto; Kunto, W; Hayati, N; Irma, S H
1996-01-01
A study has been done on the determination of thyroid volume by scintigraphic method in comparison to ultrasonographic technique, which involved a healthy woman volunteer, 5 women patients and a man patient with thyroid diseases. Scintigraphic examination upon the patient's thyroid was performed using a gamma camera 20 minutes following the injection of 55.5 Mbq (1.5 mCi) Tc-99m pertechnetate. A computer, with a dedicated program, coupled to the gamma camera was employed in the calculation of thyroid volume based on the scintigraphic data. Subsequent to the scintigraphic study, ultrasonographic determination of thyroid volume was then carried out. Correlation test that was applied to the outcome of the two methods of thyroid volume determination resulted in an excellent coefficient of correlation, R, which was 0.99. This showed a very good correlation between these two different techniques of thyroid volume determination