Normal forms in Poisson geometry
Marcut, I.T.
2013-01-01
The structure of Poisson manifolds is highly nontrivial even locally. The first important result in this direction is Conn's linearization theorem around fixed points. One of the main results of this thesis (Theorem 2) is a normal form theorem in Poisson geometry, which is the Poisson-geometric
Sack, Kevin L.; Baillargeon, Brian; Acevedo-Bolton, Gabriel; Genet, Martin; Rebelo, Nuno; Kuhl, Ellen; Klein, Liviu; Weiselthaler, Georg M.; Burkhoff, Daniel; Franz, Thomas; Guccione, Julius M.
2016-01-01
Purpose: Heart failure is a worldwide epidemic that is unlikely to change as the population ages and life expectancy increases. We sought to detail significant recent improvements to the Dassault Systèmes Living Heart Model (LHM) and use the LHM to compute left ventricular (LV) and right ventricular (RV) myofiber stress distributions under the following 4 conditions: (1) normal cardiac function; (2) acute left heart failure (ALHF); (3) ALHF treated using an LV assist device (LVAD) flow rate o...
Crystallization features of normal alkanes in confined geometry.
Su, Yunlan; Liu, Guoming; Xie, Baoquan; Fu, Dongsheng; Wang, Dujin
2014-01-21
How polymers crystallize can greatly affect their thermal and mechanical properties, which influence the practical applications of these materials. Polymeric materials, such as block copolymers, graft polymers, and polymer blends, have complex molecular structures. Due to the multiple hierarchical structures and different size domains in polymer systems, confined hard environments for polymer crystallization exist widely in these materials. The confined geometry is closely related to both the phase metastability and lifetime of polymer. This affects the phase miscibility, microphase separation, and crystallization behaviors and determines both the performance of polymer materials and how easily these materials can be processed. Furthermore, the size effect of metastable states needs to be clarified in polymers. However, scientists find it difficult to propose a quantitative formula to describe the transition dynamics of metastable states in these complex systems. Normal alkanes [CnH2n+2, n-alkanes], especially linear saturated hydrocarbons, can provide a well-defined model system for studying the complex crystallization behaviors of polymer materials, surfactants, and lipids. Therefore, a deeper investigation of normal alkane phase behavior in confinement will help scientists to understand the crystalline phase transition and ultimate properties of many polymeric materials, especially polyolefins. In this Account, we provide an in-depth look at the research concerning the confined crystallization behavior of n-alkanes and binary mixtures in microcapsules by our laboratory and others. Since 2006, our group has developed a technique for synthesizing nearly monodispersed n-alkane containing microcapsules with controllable size and surface porous morphology. We applied an in situ polymerization method, using melamine-formaldehyde resin as shell material and nonionic surfactants as emulsifiers. The solid shell of microcapsules can provide a stable three-dimensional (3-D
Differential geometry of CR-submanifolds of a normal almost para contact manifold
International Nuclear Information System (INIS)
Shahid, M.H.
1992-12-01
The aim of this paper is to study the geometry of CR-submanifolds of a normal almost para contact manifold. We discuss the integrability conditions of distributions involved in the definition and geometry of leaves of CR-submanifolds, some results on CR-submanifolds with parallel structures and contact CR-product are also given. (author). 10 refs
Directory of Open Access Journals (Sweden)
Shuxia Wang
2015-01-01
Full Text Available Background: The association of metabolic syndrome (MS with left ventricular (LV hypertrophy is controversial. The objective of our study was to investigate the influence of MS on LV mass and geometry in community-based hypertensive patients among Han Chinese. Materials and Methods: This study included 1733 metabolic syndrome patients according to the International Diabetes Federation (IDF definition and 2373 non-MS hypertension patients. LV hypertrophy was diagnosed by the criteria of LV mass ≥49.2 g/m 2.7 for men and 46.7 g/m 2.7 for women. LV geometric patterns (normal, concentric remodeling, concentric or eccentric hypertrophy were calculated according to LV hypertrophy and relative wall thickness. Logistic regression analysis was used to determine odds ratio (OR and 95% confidence interval (CI of MS for LV hypertrophy and LV geometry abnormality. Results: The LV mass and LV mass index were higher in the MS group than in the non-MS group. In multiple adjusted models. LV mass index, LV mass, interventricular septum, and post wall were raised with the increased number of MS disorders. MS was associated with increased LV hypertrophy risk (unadjusted OR 1.38; 95% CI 1.21-1.57; age, sex, and blood pressure (BP; adjusted OR 1.39; 95% CI 1.22-1.59. MS was also associated with increased risk of eccentric hypertrophy in male and female patients. MS was only associated with increased risk of concentric hypertrophy in female patients; and MS was not associated with concentric remodeling. Conclusion: LV mass and LV mass index were associated with the increased number of MS disorders in the Chinese community-based hypertensive population. MS was not only associated with increased LV hypertrophy risk, but also associated with concentric and eccentric LV geometry abnormality, especially in females.
Sossinsky, A B
2012-01-01
The book is an innovative modern exposition of geometry, or rather, of geometries; it is the first textbook in which Felix Klein's Erlangen Program (the action of transformation groups) is systematically used as the basis for defining various geometries. The course of study presented is dedicated to the proposition that all geometries are created equal--although some, of course, remain more equal than others. The author concentrates on several of the more distinguished and beautiful ones, which include what he terms "toy geometries", the geometries of Platonic bodies, discrete geometries, and classical continuous geometries. The text is based on first-year semester course lectures delivered at the Independent University of Moscow in 2003 and 2006. It is by no means a formal algebraic or analytic treatment of geometric topics, but rather, a highly visual exposition containing upwards of 200 illustrations. The reader is expected to possess a familiarity with elementary Euclidean geometry, albeit those lacking t...
Indian Academy of Sciences (India)
. In the previous article we looked at the origins of synthetic and analytic geometry. More practical minded people, the builders and navigators, were studying two other aspects of geometry- trigonometry and integral calculus. These are actually ...
Prasolov, V V
2015-01-01
This book provides a systematic introduction to various geometries, including Euclidean, affine, projective, spherical, and hyperbolic geometries. Also included is a chapter on infinite-dimensional generalizations of Euclidean and affine geometries. A uniform approach to different geometries, based on Klein's Erlangen Program is suggested, and similarities of various phenomena in all geometries are traced. An important notion of duality of geometric objects is highlighted throughout the book. The authors also include a detailed presentation of the theory of conics and quadrics, including the theory of conics for non-Euclidean geometries. The book contains many beautiful geometric facts and has plenty of problems, most of them with solutions, which nicely supplement the main text. With more than 150 figures illustrating the arguments, the book can be recommended as a textbook for undergraduate and graduate-level courses in geometry.
New method for computing ideal MHD normal modes in axisymmetric toroidal geometry
International Nuclear Information System (INIS)
Wysocki, F.; Grimm, R.C.
1984-11-01
Analytic elimination of the two magnetic surface components of the displacement vector permits the normal mode ideal MHD equations to be reduced to a scalar form. A Galerkin procedure, similar to that used in the PEST codes, is implemented to determine the normal modes computationally. The method retains the efficient stability capabilities of the PEST 2 energy principle code, while allowing computation of the normal mode frequencies and eigenfunctions, if desired. The procedure is illustrated by comparison with earlier various of PEST and by application to tilting modes in spheromaks, and to stable discrete Alfven waves in tokamak geometry
Pedoe, Dan
1988-01-01
""A lucid and masterly survey."" - Mathematics Gazette Professor Pedoe is widely known as a fine teacher and a fine geometer. His abilities in both areas are clearly evident in this self-contained, well-written, and lucid introduction to the scope and methods of elementary geometry. It covers the geometry usually included in undergraduate courses in mathematics, except for the theory of convex sets. Based on a course given by the author for several years at the University of Minnesota, the main purpose of the book is to increase geometrical, and therefore mathematical, understanding and to he
Parsons, L. C.; Andrews, G. T.
2012-09-01
Pseudo-reflection geometry Brillouin spectroscopy can be used to probe acoustic wave dispersion approximately along the surface normal of a material system while avoiding the difficulties associated with specularly reflected light encountered in an ideal reflection configuration. As an example of its application, we show analytically that it can be used to determine both the refractive index and bulk acoustic mode velocities of optically-isotropic non-metallic materials and confirm the utility of the approach via a series of experiments on fused quartz, gallium phosphide, water, and porous silicon films.
Reconstruction of normal forms by learning informed observation geometries from data.
Yair, Or; Talmon, Ronen; Coifman, Ronald R; Kevrekidis, Ioannis G
2017-09-19
The discovery of physical laws consistent with empirical observations is at the heart of (applied) science and engineering. These laws typically take the form of nonlinear differential equations depending on parameters; dynamical systems theory provides, through the appropriate normal forms, an "intrinsic" prototypical characterization of the types of dynamical regimes accessible to a given model. Using an implementation of data-informed geometry learning, we directly reconstruct the relevant "normal forms": a quantitative mapping from empirical observations to prototypical realizations of the underlying dynamics. Interestingly, the state variables and the parameters of these realizations are inferred from the empirical observations; without prior knowledge or understanding, they parametrize the dynamics intrinsically without explicit reference to fundamental physical quantities.
Zakaria, Zakaria; Surbakti, Muhammad Syukri; Syahreza, Saumi; Mat Jafri, Mohd. Zubir; Tan, Kok Chooi
2017-10-01
It has been already made, calibrated and tested a geometry normalized electromagnetic system (GNES) for metal defect examination. The GNES has an automatic data acquisition system which supporting the efficiency and accuracy of the measurement. The data will be displayed on the computer monitor as a graphic display then saved automatically in the Microsoft Excel format. The transmitter will transmit the frequency pair (FP) signals i.e. 112.5 Hz and 337.5 Hz; 112.5 Hz and 1012.5 Hz; 112.5 Hz and 3037.5 Hz; 337.5 Hz and 1012.5 Hz; 337.5 Hz and 3037.5 Hz. Simultaneous transmissions of two electromagnetic waves without distortions by the transmitter will induce an eddy current in the metal. This current, in turn, will produce secondary electromagnetic fields which are measured by the receiver together with the primary fields. Measurement of percent change of a vertical component of the fields will give the percent response caused by the metal or the defect. The response examinations were performed by the models with various type of defect for the master curves. The materials of samples as a plate were using Aluminum, Brass, and Copper. The more of the defects is the more reduction of the eddy current response. The defect contrasts were tended to decrease when the more depth of the defect position. The magnitude and phase of the eddy currents will affect the loading on the coil thus its impedance. The defect must interrupt the surface eddy current flow to be detected. Defect lying parallel to the current path will not cause any significant interruption and may not be detected. The main factors which affect the eddy current response are metal conductivity, permeability, frequency, and geometry.
Pat, Betty; Killingsworth, Cheryl; Chen, Yuanwen; Gladden, James D; Walcott, Greg; Powell, Pamela C; Denney, Thomas; Gupta, Himanshu; Desai, Ravi; Tillson, Michael; Dillon, A Ray; Dell'italia, Louis J
2010-09-01
Mast cells are increased in isolated mitral regurgitation (MR) in the dog and may mediate extracellular matrix loss and left ventricular (LV) dilatation. We tested the hypothesis that mast cell stabilization would attenuate LV remodeling and improve function in the MR dog. MR was induced in adult dogs randomized to no treatment (MR, n = 5) or to the mast cell stabilizer, ketotifen (MR + MCS, n = 4) for 4 months. LV hemodynamics were obtained at baseline and after 4 months of MR and magnetic resonance imaging (MRI) was performed at sacrifice. MRI-derived, serial, short-axis LV end-diastolic (ED) and end-systolic (ES) volumes, LVED volume/mass ratio, and LV 3-dimensional radius/wall thickness were increased in MR and MR + MCS dogs compared with normal dogs (n = 6) (P < .05). Interstitial collagen was decreased by 30% in both MR and MR + MCS versus normal dogs (P < .05). LV contractility by LV maximum time-varying elastance was significantly depressed in MR and MR + MCS dogs. Furthermore, cardiomyocyte fractional shortening was decreased in MR versus normal dogs and further depressed in MR + MCS dogs (P < .05). In vitro administration of ketotifen to normal cardiomyocytes also significantly decreased fractional shortening and calcium transients. Chronic mast cell stabilization did not attenuate eccentric LV remodeling or collagen loss in MR. However, MCS therapy had a detrimental effect on LV function because of a direct negative inotropic effect on cardiomyocyte function. Published by Elsevier Inc.
Schlecht-Louf, Géraldine; Mangeney, Marianne; El-Garch, Hanane; Lacombe, Valérie; Poulet, Hervé; Heidmann, Thierry
2014-01-01
We previously delineated a highly conserved immunosuppressive (IS) domain within murine and primate retroviral envelope proteins that is critical for virus propagation in vivo. The envelope-mediated immunosuppression was assessed by the ability of the proteins, when expressed by allogeneic tumor cells normally rejected by engrafted mice, to allow these cells to escape, at least transiently, immune rejection. Using this approach, we identified key residues whose mutation (i) specifically abolishes immunosuppressive activity without affecting the "mechanical" function of the envelope protein and (ii) significantly enhances humoral and cellular immune responses elicited against the virus. The objective of this work was to study the immunosuppressive activity of the envelope protein (p15E) of feline leukemia virus (FeLV) and evaluate the effect of its abolition on the efficacy of a vaccine against FeLV. Here we demonstrate that the FeLV envelope protein is immunosuppressive in vivo and that this immunosuppressive activity can be "switched off" by targeted mutation of a specific amino acid. As a result of the introduction of the mutated envelope sequence into a previously well characterized canarypox virus-vectored vaccine (ALVAC-FeLV), the frequency of vaccine-induced FeLV-specific gamma interferon (IFN-γ)-producing cells was increased, whereas conversely, the frequency of vaccine-induced FeLV-specific interleukin-10 (IL-10)-producing cells was reduced. This shift in the IFN-γ/IL-10 response was associated with a higher efficacy of ALVAC-FeLV against FeLV infection. This study demonstrates that FeLV p15E is immunosuppressive in vivo, that the immunosuppressive domain of p15E can modulate the FeLV-specific immune response, and that the efficacy of FeLV vaccines can be enhanced by inhibiting the immunosuppressive activity of the IS domain through an appropriate mutation.
Kettermann, M.; van Gent, H. W.; Urai, J. L.
2012-04-01
Brittle rocks, such as for example those hosting many carbonate or sandstone reservoirs, are often affected by different kinds of fractures that influence each other. Understanding the effects of these interactions on fault geometries and the formation of cavities and potential fluid pathways might be useful for reservoir quality prediction and production. Analogue modeling has proven to be a useful tool to study faulting processes, although usually the used materials do not provide cohesion and tensile strength, which are essential to create open fractures. Therefore, very fine-grained, cohesive, hemihydrate powder was used for our experiments. The mechanical properties of the material are scaling well for natural prototypes. Due to the fine grain size structures are preserved in in great detail. The used deformation box allows the formation of a half-graben and has initial dimensions of 30 cm width, 28 cm length and 20 cm height. The maximum dip-slip along the 60° dipping predefined basement fault is 4.5 cm and was fully used in all experiments. To setup open joints prior to faulting, sheets of paper placed vertically within the box to a depth of about 5 cm from top. The powder was then sieved into the box, embedding the paper almost entirely. Finally strings were used to remove the paper carefully, leaving open voids. Using this method allows the creation of cohesionless open joints while ensuring a minimum impact on the sensitive surrounding material. The presented series of experiments aims to investigate the effect of different angles between the strike of a rigid basement fault and a distinct joint set. All experiments were performed with a joint spacing of 2.5 cm and the fault-joint angles incrementally covered 0°, 4°, 8°, 12°, 16°, 20° and 25°. During the deformation time lapse photography from the top and side captured every structural change and provided data for post-processing analysis using particle imaging velocimetry (PIV). Additionally
Bertinelli, F; Berthollon-Vitte, S; Glaude, D; Vanenkov, I
2006-01-01
The quality control implemented at all LHC dipole assemblers includes precise mechanical measurements of the geometry of collared coils. A cross-analysis performed between mechanical and magnetic measurements data shows a correlation between collared coils outer dimensions and the normal quadrupole multipole (b2) for one dipole assembler. The profile geometry of the single collars - as determined from 3D measurements at the collar suppliers and CERN - could not account alone for the significant left â right aperture asymmetry observed. This triggered a deeper investigation on different elements of the geometry of single collars. The results of this work show that the relative positioning of the collaring holes, allowing a small bending deformation of collars under the effect of coil pre-stress, is an important effect that generates a b2 multipole at the limit of specification. The study has deepened the understanding of the factors affecting collared coil geometry and field quality. The precision of 3D m...
DEFF Research Database (Denmark)
Verma, Anil; Meris, Alessandra; Skali, Hicham
2008-01-01
associated with RWT was independent of LVMi. CONCLUSIONS: Increased baseline LV mass and abnormal LV geometry portend an increased risk for morbidity and mortality following high-risk myocardial infarction. Concentric LV hypertrophy carries the greatest risk of adverse cardiovascular events including death...... cardiovascular events. METHODS: Quantitative echocardiographic analyses were performed at baseline in 603 patients from the VALIANT (VALsartan In Acute myocardial iNfarcTion) echocardiographic study. The left ventricular mass index (LVMi) and relative wall thickness (RWT) were calculated. Patients were...... classified into 4 mutually exclusive groups based on RWT and LVMi as follows: normal geometry (normal LVMi and normal RWT), concentric remodeling (normal LVMi and increased RWT), eccentric hypertrophy (increased LVMi and normal RWT), and concentric hypertrophy (increased LVMi and increased RWT). Cox...
Sredar, Nripun; Ivers, Kevin M.; Queener, Hope M.; Zouridakis, George; Porter, Jason
2013-01-01
En face adaptive optics scanning laser ophthalmoscope (AOSLO) images of the anterior lamina cribrosa surface (ALCS) represent a 2D projected view of a 3D laminar surface. Using spectral domain optical coherence tomography images acquired in living monkey eyes, a thin plate spline was used to model the ALCS in 3D. The 2D AOSLO images were registered and projected onto the 3D surface that was then tessellated into a triangular mesh to characterize differences in pore geometry between 2D and 3D images. Following 3D transformation of the anterior laminar surface in 11 normal eyes, mean pore area increased by 5.1 ± 2.0% with a minimal change in pore elongation (mean change = 0.0 ± 0.2%). These small changes were due to the relatively flat laminar surfaces inherent in normal eyes (mean radius of curvature = 3.0 ± 0.5 mm). The mean increase in pore area was larger following 3D transformation in 4 glaucomatous eyes (16.2 ± 6.0%) due to their more steeply curved laminar surfaces (mean radius of curvature = 1.3 ± 0.1 mm), while the change in pore elongation was comparable to that in normal eyes (−0.2 ± 2.0%). This 3D transformation and tessellation method can be used to better characterize and track 3D changes in laminar pore and surface geometries in glaucoma. PMID:23847739
L.V. switchgear - design and development
International Nuclear Information System (INIS)
Armes, D.S.; Brown, R.D.
1992-01-01
This work describes the methods employed in the design and development of L.V. switchgear to meet the prospective conditions and operational requirements imposed on equipment at sites of PWR power stations. The work concentrates on the aspects of design, manufacture, qualification work and quality assurance particular to the range of L.V. switchgear distribution boards manufactured by Laurence, Scott and Electromotors Ltd. for Sizewell B Power Station and contrasts this equipment with other equipment for conventional (i.e. non-nuclear) power station purposes. (Author)
International Nuclear Information System (INIS)
Flotats, A.; Camacho, V.; Mena, E.; Tembl, A.; Estorch, M.; Carrio, I.; Serra-Grima, R.; Borras, X.; Cinca, J.
2002-01-01
Aim: Marked ventricular re-polarization abnormalities (MRA) in athletes may suggest the presence of associated heart disease. Assessment of LV function during exercise may contribute to rule out heart disease and help to decide continuation of physical training. The aim of the study was to assess whether athletes with MRA show a particular response of LV function to exhausting exercise. Material and Methods: Thirty-nine male athletes underwent monitoring of LV function with a miniaturised radionuclide detector (VEST, Capintec, Inc.) during bicycle exhausting exercise. There were 22 athletes with MRA in the ECG at rest (negative T waves equal or more than 2mm in up to 3 ECG leads) and 17 with normal ECG. All were symptom free. Age and physical fitness were comparable in both groups. Clinical examination, ECG, exercise test and echocardiography were performed in all athletes. Results: In all cases LV wall thickness was that expected for highly conditioned sportsmen. Both groups of athletes attained a similar energy expenditure. During exercise, athletes with MRA showed a tendency to normalise re-polarization. There were no differences in heart rate, LV end-systolic volume, LVEF, cardiac output , and peak ejection and filling rates at rest, 50%, 75%, 85% and 100% of peak HR, nor at 2, 5 and 10 min of recovery between both groups of athletes. At rest stroke volume was lower in athletes with MRA (60% vs. 64%, p=0.044). There were also no differences in LV end-diastolic volume (EDV), except at peak HR, when EDV increased in athletes with normal ECG while it decreased in athletes with MRA (p=0.047). Conclusions: The presence of marked ventricular re-polarization abnormalities in athletes does not substantially affect exercise performance nor LV function and should not preclude physical training. The VEST is a useful means to assess LV function during exhausting upright bicycle exercise
Protection of LV system against lightning
Yordanova Nedyalkova, Greta
2010-01-01
Lightning is a natural hazard and one of the greatest local mysteries. Scientists have not fully understood the mechanism of lightning. It is one of the most beautiful displays in nature and one of the nature's most dangerous phenomenon known to man. Overvoltage due to lightning is a very important problem of LV systems. Some lightning flashes damage buildings and a few kill or injure people and animals, either directly or indirectly, by causing fire and explosions. The need for protect...
Tilapia lake virus (TiLV): Literature review
Jansen, Mona Dverdal; Mohan, Chadag Vishnumurthy
2017-01-01
Tilapia lake virus (TiLV) is an emerging infectious agent that has recently been identified in diseased tilapia on three continents. At the time of writing, scientific publications have reported TiLV in samples collected from Colombia, Ecuador, Egypt, Israel and Thailand. While the link between TiLV and disease outbreaks in Israel and Thailand are well documented, further investigations are being undertaken to determine the significance of TiLV in the other countries. Israel and Taiwan Provin...
Zhao, Yongguang; Li, Chuanrong; Ma, Lingling; Tang, Lingli; Wang, Ning; Zhou, Chuncheng; Qian, Yonggang
2017-10-01
Time series of satellite reflectance data have been widely used to characterize environmental phenomena, describe trends in vegetation dynamics and study climate change. However, several sensors with wide spatial coverage and high observation frequency are usually designed to have large field of view (FOV), which cause variations in the sun-targetsensor geometry in time-series reflectance data. In this study, on the basis of semiempirical kernel-driven BRDF model, a new semi-empirical model was proposed to normalize the sun-target-sensor geometry of remote sensing image. To evaluate the proposed model, bidirectional reflectance under different canopy growth conditions simulated by Discrete Anisotropic Radiative Transfer (DART) model were used. The semi-empirical model was first fitted by using all simulated bidirectional reflectance. Experimental result showed a good fit between the bidirectional reflectance estimated by the proposed model and the simulated value. Then, MODIS time-series reflectance data was normalized to a common sun-target-sensor geometry by the proposed model. The experimental results showed the proposed model yielded good fits between the observed and estimated values. The noise-like fluctuations in time-series reflectance data was also reduced after the sun-target-sensor normalization process.
Verma, Anil; Meris, Alessandra; Skali, Hicham; Ghali, Jalal K; Arnold, J Malcolm O; Bourgoun, Mikhail; Velazquez, Eric J; McMurray, John J V; Kober, Lars; Pfeffer, Marc A; Califf, Robert M; Solomon, Scott D
2008-09-01
This study sought to understand prognostic implications of increased baseline left ventricular (LV) mass and geometric patterns in a high risk acute myocardial infarction. The LV hypertrophy and alterations in LV geometry are associated with an increased risk of adverse cardiovascular events. Quantitative echocardiographic analyses were performed at baseline in 603 patients from the VALIANT (VALsartan In Acute myocardial iNfarcTion) echocardiographic study. The left ventricular mass index (LVMi) and relative wall thickness (RWT) were calculated. Patients were classified into 4 mutually exclusive groups based on RWT and LVMi as follows: normal geometry (normal LVMi and normal RWT), concentric remodeling (normal LVMi and increased RWT), eccentric hypertrophy (increased LVMi and normal RWT), and concentric hypertrophy (increased LVMi and increased RWT). Cox proportional hazards models were used to evaluate the relationships among LVMi, RWT, LV geometry, and clinical outcomes. Mean LVMi and RWT were 98.8 +/- 28.4 g/m(2) and 0.38 +/- 0.08. The risk of death or the composite end point of death from cardiovascular causes, reinfarction, heart failure, stroke, or resuscitation after cardiac arrest was lowest for patients with normal geometry, and increased with concentric remodeling (hazard ratio [HR]: 3.0; 95% confidence interval [CI]: 1.9 to 4.9), eccentric hypertrophy (HR: 3.1; 95% CI: 1.9 to 4.8), and concentric hypertrophy (HR: 5.4; 95% CI: 3.4 to 8.5), after adjusting for baseline covariates. Also, baseline LVMi and RWT were associated with increased mortality and nonfatal cardiovascular outcomes (HR: 1.22 per 10 g/m(2) increase in LVMi; 95% CI: 1.20 to 1.30; p independent of LVMi. Increased baseline LV mass and abnormal LV geometry portend an increased risk for morbidity and mortality following high-risk myocardial infarction. Concentric LV hypertrophy carries the greatest risk of adverse cardiovascular events including death. Higher RWT was associated with an
Burdette, A C
1971-01-01
Analytic Geometry covers several fundamental aspects of analytic geometry needed for advanced subjects, including calculus.This book is composed of 12 chapters that review the principles, concepts, and analytic proofs of geometric theorems, families of lines, the normal equation of the line, and related matters. Other chapters highlight the application of graphing, foci, directrices, eccentricity, and conic-related topics. The remaining chapters deal with the concept polar and rectangular coordinates, surfaces and curves, and planes.This book will prove useful to undergraduate trigonometric st
Spinning geometry = Twisted geometry
International Nuclear Information System (INIS)
Freidel, Laurent; Ziprick, Jonathan
2014-01-01
It is well known that the SU(2)-gauge invariant phase space of loop gravity can be represented in terms of twisted geometries. These are piecewise-linear-flat geometries obtained by gluing together polyhedra, but the resulting geometries are not continuous across the faces. Here we show that this phase space can also be represented by continuous, piecewise-flat three-geometries called spinning geometries. These are composed of metric-flat three-cells glued together consistently. The geometry of each cell and the manner in which they are glued is compatible with the choice of fluxes and holonomies. We first remark that the fluxes provide each edge with an angular momentum. By studying the piecewise-flat geometries which minimize edge lengths, we show that these angular momenta can be literally interpreted as the spin of the edges: the geometries of all edges are necessarily helices. We also show that the compatibility of the gluing maps with the holonomy data results in the same conclusion. This shows that a spinning geometry represents a way to glue together the three-cells of a twisted geometry to form a continuous geometry which represents a point in the loop gravity phase space. (paper)
Application of MV/LV Transformers with OLTC for Increasing the PV Hosting Capacity Of LV Grids
DEFF Research Database (Denmark)
Hashemi Toghroljerdi, Seyedmostafa; Heckmann, Wolfram; Geibel, Dominik
2015-01-01
The increased use of grid connected photovoltaic (PV) systems in low voltage (LV) grids also raises concern regarding the effects of these new generation units on the grid operation. Overvoltage in LV grids during high PV generation periods is one of the well-known effects caused by PV systems......) and the reactive power absorption by PV inverters, are investigated using field test results and simulations performed on the mentioned LV grid. The results show that the application of OLTC can effectively increase the PV hosting capacity of the grid......., which potentially can decrease the PV hosting capacity of electric grids. This paper presents the applications of medium voltage to low voltage (MV/LV) transformers with on-load tap changers (OLTCs) to prevent overvoltage in high PV penetration conditions. Autonomous methods for controlling...
Formation and characterization of FeLV iscoms.
L. Akerblom; K. Strö mstedt; S. Hö glund; A.D.M.E. Osterhaus (Albert); B. Morein (Bror)
1989-01-01
textabstractImmunostimulating complexes (ISCOMs) have been prepared from feline leukaemia virus (FeLV) envelope proteins. The ISCOMs were characterized biochemically in SDS-polyacrylamide gel electrophoresis showing the presence of proteins of estimated molecular weights of 15,000, 27,000 and
Smart curtailment for congestion management in LV distribution network
Haque, A. N.M.M.; Rahman, M. T.; Nguyen, P. H.; Bliek, F. W.
2016-01-01
The rapid proliferation of distributed energy resources (DERs) leads to capacity challenges, i.e. network congestions, in the low-voltage (LV) distribution networks. A number of strategies are being widely studied to tackle the challenges with direct switching actions such as load shedding or power
Directory of Open Access Journals (Sweden)
Caruppannan Ketheswaram
2011-04-01
Full Text Available Abstract Background In patients with severe aortic stenosis (AS, long-term data tracking surgically induced effects of afterload reduction on reverse LV remodeling are not available. Echocardiographic data is available short term, but in limited fashion beyond one year. Cardiovascular MRI (CMR offers the ability to serially track changes in LV metrics with small numbers due to its inherent high spatial resolution and low variability. Hypothesis We hypothesize that changes in LV structure and function following aortic valve replacement (AVR are detectable by CMR and once triggered by AVR, continue for an extended period. Methods Tweny-four patients of which ten (67 ± 12 years, 6 female with severe, but compensated AS underwent CMR pre-AVR, 6 months, 1 year and up to 4 years post-AVR. 3D LV mass index, volumetrics, LV geometry, and EF were measured. Results All patients survived AVR and underwent CMR 4 serial CMR's. LVMI markedly decreased by 6 months (157 ± 42 to 134 ± 32 g/m2, p 2. Similarly, EF increased pre to post-AVR (55 ± 22 to 65 ± 11%,(p 2. LV stroke volume increased rapidly from pre to post-AVR (40 ± 11 to 44 ± 7 ml, p Conclusion After initial beneficial effects imparted by AVR in severe AS patients, there are, as expected, marked improvements in LV reverse remodeling. Via CMR, surgically induced benefits to LV structure and function are durable and, unexpectedly express continued, albeit markedly incomplete improvement through 4 years post-AVR concordant with sustained improved clinical status. This supports down-regulation of both mRNA and MMP activity acutely with robust suppression long term.
Avoided losses on LV networks as a result of microgeneration
Energy Technology Data Exchange (ETDEWEB)
Costa, Paulo Moises [Escola Superior Tecnologia Viseu, Instituto Politecnico Viseu, Campus Politecnico Repeses, 3504-510 Viseu (Portugal); Matos, Manuel A. [INESC Porto, Faculdade de Engenharia da Universidade do Porto, Porto (Portugal)
2009-04-15
In the scope of the discussions about microgeneration (and microgrids), the avoided electrical losses are often pointed out as an important value to be credited to those entities. Therefore, methods to assess the impact of microgeneration on losses must be developed in order to support the definition of a suitable regulatory framework for the economic integration of microgeneration on distribution networks. This paper presents an analytical method to quantify the value of avoided losses that microgeneration may produce on LV networks. Intervals of expected avoided losses are used to account for the variation of avoided losses due to the number, size and location of microgenerators, as well as for the kind of load distribution on LV networks. (author)
A Dynamic and Heuristic Phase Balancing Method for LV Feeders
Directory of Open Access Journals (Sweden)
Samad Taghipour Boroujeni
2016-01-01
Full Text Available Due to the single-phase loads and their stochastic behavior, the current in the distribution feeders is not balanced. In addition, the single-phase loads are located in different positions along the LV feeders. So the amount of the unbalanced load and its location affect the feeder losses. An unbalanced load causes the feeder losses and the voltage drop. Because of time-varying behavior of the single-phase loads, phase balancing is a dynamic and combinatorial problem. In this research, a heuristic and dynamic solution for the phase balancing of the LV feeders is proposed. In this method, it is supposed that the loads’ tie could be connected to all phases through a three-phase switch. The aim of the proposed method is to make the feeder conditions as balanced as possible. The amount and the location of single-phase loads are considered in the proposed phase balancing method. Since the proposed method needs no communication interface or no remote controller, it is inexpensive, simple, practical, and robust. Applying this method provides a distributed and dynamic phase balancing control. In addition, the feasibility of reducing the used switches is investigated. The ability of the proposed method in the phase balancing of the LV feeders is approved by carrying out some simulations.
Piacentino, Michael L; Chung, Oliver; Ramachandran, Janani; Zuch, Daniel T; Yu, Jia; Conaway, Evan A; Reyna, Arlene E; Bradham, Cynthia A
2016-04-01
Skeletal patterning in the sea urchin embryo requires coordinated signaling between the pattern-dictating ectoderm and the skeletogenic primary mesenchyme cells (PMCs); recent studies have begun to uncover the molecular basis for this process. Using an unbiased RNA-Seq-based screen, we have previously identified the TGF-ß superfamily ligand, LvBMP5-8, as a skeletal patterning gene in Lytechinus variegatus embryos. This result is surprising, since both BMP5-8 and BMP2/4 ligands have been implicated in sea urchin dorsal-ventral (DV) and left-right (LR) axis specification. Here, we demonstrate that zygotic LvBMP5-8 is required for normal skeletal patterning on the left side, as well as for normal PMC positioning during gastrulation. Zygotic LvBMP5-8 is required for expression of the left-side marker soxE, suggesting that LvBMP5-8 is required for left-side specification. Interestingly, we also find that LvBMP5-8 knockdown suppresses serotonergic neurogenesis on the left side. While LvBMP5-8 overexpression is sufficient to dorsalize embryos, we find that zygotic LvBMP5-8 is not required for normal DV specification or development. In addition, ectopic LvBMP5-8 does not dorsalize LvBMP2/4 morphant embryos, indicating that, in the absence of BMP2/4, BMP5-8 is insufficient to specify dorsal. Taken together, our data demonstrate that zygotic LvBMP5-8 signaling is essential for left-side specification, and for normal left-side skeletal and neural patterning, but not for DV specification. Thus, while both BMP2/4 and BMP5-8 regulate LR axis specification, BMP2/4 but not zygotic BMP5-8 regulates DV axis specification in sea urchin embryos. Copyright © 2016 Elsevier Inc. All rights reserved.
Role of HIV-2 envelope in Lv2-mediated restriction
International Nuclear Information System (INIS)
Reuter, Sandra; Kaumanns, Patrick; Buschhorn, Sabine B.; Dittmar, Matthias T.
2005-01-01
We have characterized envelope protein pseudotyped HIV-2 particles derived from two HIV-2 isolates termed prCBL23 and CBL23 in order to define the role of the envelope protein for the Lv2-mediated restriction to infection. Previously, it has been described that the primary isolate prCBL23 is restricted to infection of several human cell types, whereas the T cell line adapted isolate CBL23 is not restricted in these cell types. Molecular cloning of the two isolates revealed that the env and the gag gene are responsible for the observed phenotype and that this restriction is mediated by Lv2, which is distinct from Ref1/Lv1 (Schmitz, C., Marchant, D., Neil, S.J., Aubin, K., Reuter, S., Dittmar, M.T., McKnight, A., Kizhatil, K., Albritton, L.M., 2004. Lv2, a novel postentry restriction, is mediated by both capsid and envelope. J. Virol. 78 (4), 2006-2016). We generated pseudotyped viruses consisting of HIV-2 (ROD-AΔenv-GFP, ROD-AΔenv-RFP, or ROD-AΔenv-REN) and the prCBL23 or CBL23 envelope proteins as well as chimeric proteins between these envelopes. We demonstrate that a single amino acid exchange at position 74 in the surface unit of CBL23-Env confers restriction to infection. This single point mutation causes tighter CD4 binding, resulting in a less efficient fusion into the cytosol of the restricted cell line. Prevention of endosome formation and prevention of endosome acidification enhance infectivity of the restricted particles for GHOST/X4 cells indicating a degradative lysosomal pathway as a cause for the reduced cytosolic entry. The described restriction to infection of the primary isolate prCBL23 is therefore largely caused by an entry defect. A remaining restriction to infection (19-fold) is preserved when endosomal acidification is prevented. This restriction to infection is also dependent on the presence of the point mutation at position 74 (G74E)
Surface glycosaminoglycans mediate adherence between HeLa cells and Lactobacillus salivarius Lv72.
Martín, Rebeca; Martín, Carla; Escobedo, Susana; Suárez, Juan E; Quirós, Luis M
2013-09-17
The adhesion of lactobacilli to the vaginal surface is of paramount importance to develop their probiotic functions. For this reason, the role of HeLa cell surface proteoglycans in the attachment of Lactobacillus salivarius Lv72, a mutualistic strain of vaginal origin, was investigated. Incubation of cultures with a variety of glycosaminoglycans (chondroitin sulfate A and C, heparin and heparan sulfate) resulted in marked binding interference. However, no single glycosaminoglycan was able to completely abolish cell binding, the sum of all having an additive effect that suggests cooperation between them and recognition of specific adhesins on the bacterial surface. In contrast, chondroitin sulfate B enhanced cell to cell attachment, showing the relevance of the stereochemistry of the uronic acid and the sulfation pattern on binding. Elimination of the HeLa surface glycosaminoglycans with lyases also resulted in severe adherence impairment. Advantage was taken of the Lactobacillus-glycosaminoglycans interaction to identify an adhesin from the bacterial surface. This protein, identify as a soluble binding protein of an ABC transporter system (OppA) by MALDI-TOF/(MS), was overproduced in Escherichia coli, purified and shown to interfere with L. salivarius Lv72 adhesion to HeLa cells. These data suggest that glycosaminoglycans play a fundamental role in attachment of mutualistic bacteria to the epithelium that lines the cavities where the normal microbiota thrives, OppA being a bacterial adhesin involved in the process.
DEFF Research Database (Denmark)
Gerdts, E.; Cramariuc, D.; Simone, G. de
2008-01-01
, and myocardial infarction) in 937 hypertensive patients with LV hypertrophy during 4.8 years losartan- or atenolol-based treatment in the Losartan Intervention for Endpoint reduction in hypertension (LIFE) echocardiography substudy. METHODS AND RESULTS: LV geometry was determined from LV mass/body surface area......AIMS: Less is known about the relation between in-treatment left ventricular (LV) geometry and risk of cardiovascular events. We assessed LV geometric patterns on baseline and annual echocardiograms as time-varying predictors of the primary composite endpoint (cardiovascular death, stroke...... including LV geometric patterns as time-varying variables and adjusting for treatment, Framingham risk score, race, and time-varying systolic blood pressure, the patterns independently predicted higher risk of primary composite endpoints [HR 2.99 (1.16-7.71) for concentric remodelling, HR 1.79 (1...
Iversen, Birger
1992-01-01
Although it arose from purely theoretical considerations of the underlying axioms of geometry, the work of Einstein and Dirac has demonstrated that hyperbolic geometry is a fundamental aspect of modern physics
E/e' Ratio: An Index of LV Filling Pressures Revisited
Directory of Open Access Journals (Sweden)
Sherif F. Nagueh
2013-01-01
Full Text Available There is a clinical need for the assessment of cardiac function in patients who present with symptoms and signs of pulmonary and systemic congestion. Echocardiography has been utilized over the years to answer this question. It is possible to study left ventricular (LV systolic and diastolic function as well as pulmonary artery pressures and right ventricular function using this technique. With respect to LV diastolic function, an ideal assessment includes evaluation of LV relaxation and LV filling pressures. There are several parameters that when properly acquired and analyzed can predict the 2 fundamental aspects noted above of LV diastolic function. The mitral annulus early diastolic recoil velocity (e’ recorded by tissue Doppler imaging (TDI was introduced as an index of LV relaxation. Further, e’ velocity is combined with mitral peak velocity E to predict LV filling pressures1. I will discuss the supporting literature for the last statement and point to the limitations in its application.
van den Broek, P.M.
1984-01-01
The aim of this paper is to give a detailed exposition of the relation between the geometry of twistor space and the geometry of Minkowski space. The paper has a didactical purpose; no use has been made of differential geometry and cohomology.
Pat, Betty; Chen, Yuanwen; Killingsworth, Cheryl; Gladden, James D; Shi, Ke; Zheng, Junying; Powell, Pamela C; Walcott, Greg; Ahmed, Mustafa I; Gupta, Himanshu; Desai, Ravi; Wei, Chih-Chang; Hase, Naoki; Kobayashi, Tsunefumi; Sabri, Abdelkarim; Granzier, Henk; Denney, Thomas; Tillson, Michael; Dillon, A Ray; Husain, Ahsan; Dell'italia, Louis J
2010-10-12
The left ventricular (LV) dilatation of isolated mitral regurgitation (MR) is associated with an increase in chymase and a decrease in interstitial collagen and extracellular matrix. In addition to profibrotic effects, chymase has significant antifibrotic actions because it activates matrix metalloproteinases and kallikrein and degrades fibronectin. Thus, we hypothesize that chymase inhibitor (CI) will attenuate extracellular matrix loss and LV remodeling in MR. We studied dogs with 4 months of untreated MR (MR; n=9) or MR treated with CI (MR+CI; n=8). Cine MRI demonstrated a >40% increase in LV end-diastolic volume in both groups, consistent with a failure of CI to improve a 25% decrease in interstitial collagen in MR. However, LV cardiomyocyte fractional shortening was decreased in MR versus normal dogs (3.71±0.24% versus 4.81±0.31%; P<0.05) and normalized in MR+CI dogs (4.85±0.44%). MRI with tissue tagging demonstrated an increase in LV torsion angle in MR+CI versus MR dogs. CI normalized the significant decrease in fibronectin and FAK phosphorylation and prevented cardiomyocyte myofibrillar degeneration in MR dogs. In addition, total titin and its stiffer isoform were increased in the LV epicardium and paralleled the changes in fibronectin and FAK phosphorylation in MR+CI dogs. These results suggest that chymase disrupts cell surface-fibronectin connections and FAK phosphorylation that can adversely affect cardiomyocyte myofibrillar structure and function. The greater effect of CI on epicardial versus endocardial titin and noncollagen cell surface proteins may be responsible for the increase in torsion angle in chronic MR.
Regulation of FeLV-945 by c-Myb binding and CBP recruitment to the LTR
Directory of Open Access Journals (Sweden)
Finstad Samantha L
2004-09-01
Full Text Available Abstract Background Feline leukemia virus (FeLV induces degenerative, proliferative and malignant hematologic disorders in its natural host, the domestic cat. FeLV-945 is a viral variant identified as predominant in a cohort of naturally infected animals. FeLV-945 contains a unique sequence motif in the long terminal repeat (LTR comprised of a single copy of transcriptional enhancer followed by a 21-bp sequence triplicated in tandem. The LTR is precisely conserved among independent cases of multicentric lymphoma, myeloproliferative disease and anemia in animals from the cohort. The 21-bp triplication was previously shown to act as a transcriptional enhancer preferentially in hematopoietic cells and to confer a replicative advantage. The objective of the present study was to examine the molecular mechanism by which the 21-bp triplication exerts its influence and the selective advantage responsible for its precise conservation. Results Potential binding sites for the transcription factor, c-Myb, were identified across the repeat junctions of the 21-bp triplication. Such sites would not occur in the absence of the repeat; thus, a requirement for c-Myb binding to the repeat junctions of the triplication would exert a selective pressure to conserve its sequence precisely. Electrophoretic mobility shift assays demonstrated specific binding of c-Myb to the 21-bp triplication. Reporter gene assays showed that the triplication-containing LTR is responsive to c-Myb, and that responsiveness requires the presence of both c-Myb binding sites. Results further indicated that c-Myb in complex with the 21-bp triplication recruits the transcriptional co-activator, CBP, a regulator of normal hematopoiesis. FeLV-945 replication was shown to be positively regulated by CBP in a manner dependent on the presence of the 21-bp triplication. Conclusion Binding sites for c-Myb across the repeat junctions of the 21-bp triplication may account for its precise conservation in
Energy Technology Data Exchange (ETDEWEB)
Ban, Kazunobu; Nakajima, Toru; Aoki, Naoto; Abe, Sumihisa; Handa, Shunnosuke; Suzuki, Yutaka [Tokai Univ., Isehara, Kanagawa (Japan). School of Medicine
1998-11-01
The quantitative gated SPECT (QGS) software that has automatic edge detection algorithm of the left ventricle, is able to calculate LV volumes and visualize LV wall motion with perfusion throughout the cardiac cycle. We evaluated the reliability of global and regional LV function derived from QGS using {sup 99m}Tc-tetrofosmin by comparing with left ventricular cineangiography (LVG) and echocardiography (ECHO). In 22 cardiac patients, end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (LVEF) were calculated. Using cinematic display, regional LV wall motion were scored on a 3-point scale (1=normal, 2=hypokinesis, 3=akinesis; WMS). EDV, ESV and LVEF correlated well with those by LVG (p<0.001 for each). Correlation between WMS derived from QGS and ECHO was high (r=0.85, p<0.001). There was an inverse correlation between WMS and LVEF (r=0.77, p<0.001). In conclusion, QGS is useful to evaluate global LV function. Regional wall motion evaluated by QGS is good enough for clinical application. (author)
Patel, M; Carritt, K; Lane, J; Jayappa, H; Stahl, M; Bourgeois, M
2015-07-01
Four vaccines for feline leukemia virus (FeLV) are available in the United States. This study's purpose was to compare the efficacy of Nobivac feline 2-FeLV (an inactivated, adjuvanted whole-virus vaccine) and PureVax recombinant FeLV (a live, canarypox virus-vectored vaccine) following FeLV challenge. Cats were vaccinated at 9 and 12 weeks with Nobivac feline 2-FeLV (group A, n = 11) or PureVax recombinant FeLV (group B, n = 10). Group C (n = 11) comprised unvaccinated controls. At 3 months postvaccination, cats were immunosuppressed and challenged with FeLV-A/61E. The outcomes measured were persistent antigenemia at 12 weeks postchallenge (PC) and proviral DNA and viral RNA at 3 to 9 weeks PC. Persistent antigenemia was observed in 0 of 11 cats in group A, 5 of 10 cats in group B, and 10 of 11 cats in group C. Group A was significantly protected compared to those in groups B (P 0.063). The preventable fraction was 100% for group A and 45% for group B. At 9 weeks PC, proviral DNA and viral RNA were detected 1 of 11 cats in group A, 6 of 10 cats in group B, and 9 of 11 cats in group C. Nucleic acid loads were significantly lower in group A than in group C (P feline 2-FeLV-vaccinated cats were fully protected against persistent antigenemia and had significantly smaller amounts of proviral DNA and plasma viral RNA loads than PureVax recombinant FeLV-vaccinated cats and unvaccinated controls. Copyright © 2015, Patel et al.
Rodger, Alison
1995-01-01
Molecular Geometry discusses topics relevant to the arrangement of atoms. The book is comprised of seven chapters that tackle several areas of molecular geometry. Chapter 1 reviews the definition and determination of molecular geometry, while Chapter 2 discusses the unified view of stereochemistry and stereochemical changes. Chapter 3 covers the geometry of molecules of second row atoms, and Chapter 4 deals with the main group elements beyond the second row. The book also talks about the complexes of transition metals and f-block elements, and then covers the organometallic compounds and trans
International Nuclear Information System (INIS)
Robinson, I.; Trautman, A.
1988-01-01
The geometry of classical physics is Lorentzian; but weaker geometries are often more appropriate: null geodesics and electromagnetic fields, for example, are well known to be objects of conformal geometry. To deal with a single null congruence, or with the radiative electromagnetic fields associated with it, even less is needed: flag geometry for the first, optical geometry, with which this paper is chiefly concerned, for the second. The authors establish a natural one-to-one correspondence between optical geometries, considered locally, and three-dimensional Cauchy-Riemann structures. A number of Lorentzian geometries are shown to be equivalent from the optical point of view. For example the Goedel universe, the Taub-NUT metric and Hauser's twisting null solution have an optical geometry isomorphic to the one underlying the Robinson congruence in Minkowski space. The authors present general results on the problem of lifting a CR structure to a Lorentz manifold and, in particular, to Minkowski space; and exhibit the relevance of the deviation form to this problem
Energy levels, lifetimes and radiative data of W LV
Ding, Xiao-bin; Sun, Rui; Koike, Fumihiro; Murakami, Izumi; Kato, Daiji; Sakaue, Hiroyuki A.; Nakamura, Nobuyuki; Dong, Chen-zhong
2018-01-01
Calculations of energy levels, radiative data and lifetimes are reported for tungsten Ca-like ion (W LV) by using multi-configuration Dirac-Fock (MCDF) method. The GRASP2K package is adopted to carry out a large-scale systematic computation with a restricted active space treatment; the Breit interaction and QED effects are included in subsequent relativistic configuration interaction calculations. The energies and lifetimes of the lowest 119 levels are listed; the main leading configuration of the levels is of the ground state configuration [Ne]3s23p63d2 and the first excited configuration [Ne]3s23p53d3. The wavelengths, radiative rates and oscillator strengths for relatively strong E1, E2, M1, and M2 transitions are listed. Comparisons with earlier experimental and theoretical values are made. The average relative deviations of energy levels from the NIST results and E1 transition wavelengths from the EBIT experimental results have turned to be only 0.20% and 0.13%, respectively. The other present results are in reasonable agreement with available data. These agreements confirm the reliability and accuracy of the current results. The present datasets may help us with the investigation of the electron-electron correlation effects in complex multi-electron highly charged heavy ions and of the diagnosis of tungsten impurity plasmas in fusion science.
Energy Technology Data Exchange (ETDEWEB)
Glissmeyer, John A.; Antonio, Ernest J.; Flaherty, Julia E.; Amidan, Brett G.
2014-09-30
This document reports on a series of tests conducted to assess the proposed air sampling locations for the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Group 1-2A exhaust stacks with respect to the applicable criteria regarding the placement of an air sampling probe. The LV-C2, LV-S2, and LV-S3 exhaust stacks were tested together as a group (Test Group 1-2A). This report only covers the results of LV-S2 and LV-S3; LV-C2 will be reported on separately. Federal regulations1 require that a sampling probe be located in the exhaust stack according to the criteria established by the American National Standards Institute/Health Physics Society (ANSI/HPS) N13.1-1999, Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stack and Ducts of Nuclear Facilities. 2 These criteria address the capability of the sampling probe to extract a sample that represents the effluent stream.
Pottmann, Helmut; Eigensatz, Michael; Vaxman, Amir; Wallner, Johannes
2014-01-01
Around 2005 it became apparent in the geometry processing community that freeform architecture contains many problems of a geometric nature to be solved, and many opportunities for optimization which however require geometric understanding. This area of research, which has been called architectural geometry, meanwhile contains a great wealth of individual contributions which are relevant in various fields. For mathematicians, the relation to discrete differential geometry is significant, in particular the integrable system viewpoint. Besides, new application contexts have become available for quite some old-established concepts. Regarding graphics and geometry processing, architectural geometry yields interesting new questions but also new objects, e.g. replacing meshes by other combinatorial arrangements. Numerical optimization plays a major role but in itself would be powerless without geometric understanding. Summing up, architectural geometry has become a rewarding field of study. We here survey the main directions which have been pursued, we show real projects where geometric considerations have played a role, and we outline open problems which we think are significant for the future development of both theory and practice of architectural geometry.
Pottmann, Helmut
2014-11-26
Around 2005 it became apparent in the geometry processing community that freeform architecture contains many problems of a geometric nature to be solved, and many opportunities for optimization which however require geometric understanding. This area of research, which has been called architectural geometry, meanwhile contains a great wealth of individual contributions which are relevant in various fields. For mathematicians, the relation to discrete differential geometry is significant, in particular the integrable system viewpoint. Besides, new application contexts have become available for quite some old-established concepts. Regarding graphics and geometry processing, architectural geometry yields interesting new questions but also new objects, e.g. replacing meshes by other combinatorial arrangements. Numerical optimization plays a major role but in itself would be powerless without geometric understanding. Summing up, architectural geometry has become a rewarding field of study. We here survey the main directions which have been pursued, we show real projects where geometric considerations have played a role, and we outline open problems which we think are significant for the future development of both theory and practice of architectural geometry.
Maor, Eli
2014-01-01
If you've ever thought that mathematics and art don't mix, this stunning visual history of geometry will change your mind. As much a work of art as a book about mathematics, Beautiful Geometry presents more than sixty exquisite color plates illustrating a wide range of geometric patterns and theorems, accompanied by brief accounts of the fascinating history and people behind each. With artwork by Swiss artist Eugen Jost and text by acclaimed math historian Eli Maor, this unique celebration of geometry covers numerous subjects, from straightedge-and-compass constructions to intriguing configur
International Nuclear Information System (INIS)
Wu, Q; Snyder, K; Liu, C; Huang, Y; Li, H; Chetty, I; Wen, N
2015-01-01
Purpose: To develop an optimization algorithm to reduce normal brain dose by optimizing couch and collimator angles for single isocenter multiple targets treatment of stereotactic radiosurgery. Methods: Three metastatic brain lesions were retrospectively planned using single-isocenter volumetric modulated arc therapy (VMAT). Three matrices were developed to calculate the projection of each lesion on Beam’s Eye View (BEV) by the rotating couch, collimator and gantry respectively. The island blocking problem was addressed by computing the total area of open space between any two lesions with shared MLC leaf pairs. The couch and collimator angles resulting in the smallest open areas were the optimized angles for each treatment arc. Two treatment plans with and without couch and collimator angle optimization were developed using the same objective functions and to achieve 99% of each target volume receiving full prescription dose of 18Gy. Plan quality was evaluated by calculating each target’s Conformity Index (CI), Gradient Index (GI), and Homogeneity index (HI), and absolute volume of normal brain V8Gy, V10Gy, V12Gy, and V14Gy. Results: Using the new couch/collimator optimization strategy, dose to normal brain tissue was reduced substantially. V8, V10, V12, and V14 decreased by 2.3%, 3.6%, 3.5%, and 6%, respectively. There were no significant differences in the conformity index, gradient index, and homogeneity index between two treatment plans with and without the new optimization algorithm. Conclusion: We have developed a solution to the island blocking problem in delivering radiation to multiple brain metastases with shared isocenter. Significant reduction in dose to normal brain was achieved by using optimal couch and collimator angles that minimize total area of open space between any of the two lesions with shared MLC leaf pairs. This technique has been integrated into Eclipse treatment system using scripting API
Energy Technology Data Exchange (ETDEWEB)
Wu, Q [Wayne State University, Detroit, MI (United States); Snyder, K; Liu, C; Huang, Y; Li, H; Chetty, I; Wen, N [Henry Ford Health System, Detroit, MI (United States)
2015-06-15
Purpose: To develop an optimization algorithm to reduce normal brain dose by optimizing couch and collimator angles for single isocenter multiple targets treatment of stereotactic radiosurgery. Methods: Three metastatic brain lesions were retrospectively planned using single-isocenter volumetric modulated arc therapy (VMAT). Three matrices were developed to calculate the projection of each lesion on Beam’s Eye View (BEV) by the rotating couch, collimator and gantry respectively. The island blocking problem was addressed by computing the total area of open space between any two lesions with shared MLC leaf pairs. The couch and collimator angles resulting in the smallest open areas were the optimized angles for each treatment arc. Two treatment plans with and without couch and collimator angle optimization were developed using the same objective functions and to achieve 99% of each target volume receiving full prescription dose of 18Gy. Plan quality was evaluated by calculating each target’s Conformity Index (CI), Gradient Index (GI), and Homogeneity index (HI), and absolute volume of normal brain V8Gy, V10Gy, V12Gy, and V14Gy. Results: Using the new couch/collimator optimization strategy, dose to normal brain tissue was reduced substantially. V8, V10, V12, and V14 decreased by 2.3%, 3.6%, 3.5%, and 6%, respectively. There were no significant differences in the conformity index, gradient index, and homogeneity index between two treatment plans with and without the new optimization algorithm. Conclusion: We have developed a solution to the island blocking problem in delivering radiation to multiple brain metastases with shared isocenter. Significant reduction in dose to normal brain was achieved by using optimal couch and collimator angles that minimize total area of open space between any of the two lesions with shared MLC leaf pairs. This technique has been integrated into Eclipse treatment system using scripting API.
Kemnitz, Arnfried
Der Grundgedanke der Analytischen Geometrie besteht darin, dass geometrische Untersuchungen mit rechnerischen Mitteln geführt werden. Geometrische Objekte werden dabei durch Gleichungen beschrieben und mit algebraischen Methoden untersucht.
Lefschetz, Solomon
2005-01-01
An introduction to algebraic geometry and a bridge between its analytical-topological and algebraical aspects, this text for advanced undergraduate students is particularly relevant to those more familiar with analysis than algebra. 1953 edition.
Ay, Nihat; Lê, Hông Vân; Schwachhöfer, Lorenz
2017-01-01
The book provides a comprehensive introduction and a novel mathematical foundation of the field of information geometry with complete proofs and detailed background material on measure theory, Riemannian geometry and Banach space theory. Parametrised measure models are defined as fundamental geometric objects, which can be both finite or infinite dimensional. Based on these models, canonical tensor fields are introduced and further studied, including the Fisher metric and the Amari-Chentsov tensor, and embeddings of statistical manifolds are investigated. This novel foundation then leads to application highlights, such as generalizations and extensions of the classical uniqueness result of Chentsov or the Cramér-Rao inequality. Additionally, several new application fields of information geometry are highlighted, for instance hierarchical and graphical models, complexity theory, population genetics, or Markov Chain Monte Carlo. The book will be of interest to mathematicians who are interested in geometry, inf...
Tharp, Darla L.; Ivey, Jan R.; Ganjam, Venkataseshu K.; Bowles, Douglas K.
2011-01-01
Coronary vascular dysfunction has been observed in several models of heart failure (HF). Recent evidence indicates that exercise training is beneficial for patients with HF, but the precise intensity and underlying mechanisms are unknown. Left ventricular (LV) hypertrophy can play a significant role in the development of HF; therefore, the purpose of this study was to assess the effects of low-intensity interval exercise training on coronary vascular function in sedentary (HF) and exercise trained (HF-TR) aortic-banded miniature swine displaying LV hypertrophy. Six months postsurgery, in vivo coronary vascular responses to endothelin-1 (ET-1) and adenosine were measured in the left anterior descending coronary artery. Baseline and maximal coronary vascular conductance were similar between all groups. ET-1-induced reductions in coronary vascular conductance (P < 0.05) were greater in HF vs. sedentary control and HF-TR groups. Pretreatment with the ET type A (ETA) receptor blocker BQ-123 prevented ET-1 hypersensitivity in HF animals. Whole cell voltage clamp was used to characterize composite K+ currents (IK+) in coronary smooth muscle cells. Raising internal Ca2+ from 200 to 500 nM increased Ca2+-sensitive K+ current in HF-TR and control, but not HF animals. In conclusion, an ETA-receptor-mediated hypersensitivity to ET-1, elevated resting LV wall tension, and decreased coronary smooth muscle cell Ca2+-sensitive IK+ was found in sedentary animals with LV hypertrophy. Low-intensity interval exercise training preserved normal coronary vascular function and smooth muscle cell Ca2+-sensitive IK+, illustrating a potential mechanism underlying coronary vascular dysfunction in a large-animal model of LV hypertrophy. Our results demonstrate the potential clinical impact of exercise on coronary vascular function in HF patients displaying pathological LV hypertrophy. PMID:21841018
Emter, Craig A; Tharp, Darla L; Ivey, Jan R; Ganjam, Venkataseshu K; Bowles, Douglas K
2011-10-01
Coronary vascular dysfunction has been observed in several models of heart failure (HF). Recent evidence indicates that exercise training is beneficial for patients with HF, but the precise intensity and underlying mechanisms are unknown. Left ventricular (LV) hypertrophy can play a significant role in the development of HF; therefore, the purpose of this study was to assess the effects of low-intensity interval exercise training on coronary vascular function in sedentary (HF) and exercise trained (HF-TR) aortic-banded miniature swine displaying LV hypertrophy. Six months postsurgery, in vivo coronary vascular responses to endothelin-1 (ET-1) and adenosine were measured in the left anterior descending coronary artery. Baseline and maximal coronary vascular conductance were similar between all groups. ET-1-induced reductions in coronary vascular conductance (P < 0.05) were greater in HF vs. sedentary control and HF-TR groups. Pretreatment with the ET type A (ET(A)) receptor blocker BQ-123 prevented ET-1 hypersensitivity in HF animals. Whole cell voltage clamp was used to characterize composite K(+) currents (I(K(+))) in coronary smooth muscle cells. Raising internal Ca(2+) from 200 to 500 nM increased Ca(2+)-sensitive K(+) current in HF-TR and control, but not HF animals. In conclusion, an ET(A)-receptor-mediated hypersensitivity to ET-1, elevated resting LV wall tension, and decreased coronary smooth muscle cell Ca(2+)-sensitive I(K(+)) was found in sedentary animals with LV hypertrophy. Low-intensity interval exercise training preserved normal coronary vascular function and smooth muscle cell Ca(2+)-sensitive I(K(+)), illustrating a potential mechanism underlying coronary vascular dysfunction in a large-animal model of LV hypertrophy. Our results demonstrate the potential clinical impact of exercise on coronary vascular function in HF patients displaying pathological LV hypertrophy.
Directory of Open Access Journals (Sweden)
Emílio Borges
2007-04-01
Full Text Available A simple method to obtain molecular Cartesian coordinates as a function of vibrational normal modes is presented in this work. The method does not require the definition of special matrices, like the F and G of Wilson, neither of group theory. The Eckart's conditions together with the diagonalization of kinetic and potential energy are the only required expressions. This makes the present approach appropriate to be used as a preliminary study for more advanced concepts concerning vibrational analysis. Examples are given for diatomic and triatomic molecules.
Energy Technology Data Exchange (ETDEWEB)
Viggiano Guerra, J.C.; Sandoval Medina, F.; Flores Armenta, M.C. [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)]. E-mail: fernando.sandoval@cfe.gob.mx, E-mail: magaly.flores@cfe.gob.mx; Perez, R.J. [Universidad de Calgary (Canada); Gonzalez Partida, E. [Universidad Nacional Autonoma de Mexico, Centro de Geociencias, Mexico, D.F. (Mexico)
2009-01-15
SPCALC is an excellent software application providing chemical and multi-phase speciation for geothermal fluids. Recently it was acquired by the Comision Federal de Electricidad (CFE) through a contract with the National Autonomous University of Mexico (UNAM) and the University of Calgary, Canada. Software methodology consists of calculating thermodynamic variables, such as activity (a) and fugacity (f) of chemical species, as well as the saturation indices (log Q/K) of mineral phases of the reservoir. In other words, it models the thermodynamic conditions of the reservoir (pH among other) and simulates the fluid-corrosion rate. This allows the software to foresee scaling and corrosion. In this paper, pervasive fluids in Cretaceous granitic rocks penetrated by wells LV-4A, LV-11 and LV-13 in Las Tres Virgenes geothermal field, BCS, are modeled, starting with chemical analyses. The more important ratios among activities [those which influence the fluid-rock interaction (i.e. {sup a}K{sup +}/{sup a}H{sup +}, {sup a}Ca{sup ++}/{sup a}H{sup +}, {sup a}Na{sup +}/{sup a}H{sup +}, {sup a}Mg{sup ++}/{sup a}H{sup +}) and whose results are the minerals visible under a microscope] are graphed in balance diagrams compatible with the pressure (P) and temperature (T) conditions in the reservoir. Epidote (zoisite) is the mineral found in congruent equilibrium with the system. The main mineral association at those conditions (200-250 degrees Celsius and {approx}18 bar), as observed in the well cuttings, is calcite+illite-quartz{+-}epidote, which is explained by the hydrolithic reactions that form replacement calcite in the presence of CO{sub 2}, thus restricting the formation of epidote and eventually eliminating it. The process enhances the CO{sub 2} molarity in the residual fluid, even up to {sup m}CO{sub 2} 1, which means the CO{sub 2} can be diluted back into fluid and intervene again in the process of calcite formation (2HCO{sub 3}{sup -} + Ca{sup ++} = calcite + H{sub 2}O
Studies on the synthesis of isotopes of superheavy element Lv (Z = 116)
Energy Technology Data Exchange (ETDEWEB)
Santhosh, K.P.; Safoora, V. [Kannur University, School of Pure and Applied Physics, Payyanur (India)
2017-11-15
The probable projectile-target combinations for the synthesis of superheavy nucleus {sup 296}Lv found in the cold valley of {sup 296}Lv have been identified by studying the interaction barrier of the colliding nuclei, probability of compound nucleus formation, P{sub CN}, and survival probability W{sub sur}. At energies near and above the Coulomb barrier, the capture, fusion and evaporation residue (ER) cross sections for the probable combinations for the hot and cold fusion reactions are systematically investigated. By considering intensities of the projectile beams, availabilities of the targets and half lives of the colliding nuclei, the combination {sup 48}Ca + {sup 248}Cm is found to be the most probable projectile-target pair for the synthesis of {sup 296}Lv. The calculated maximum value of 2n, 3n, 4n and 5n channel cross section for the reaction {sup 48}Ca + {sup 248}Cm are 0.599 pb, 5.957 pb, 4.805 pb, and 0.065 pb, respectively. Moreover, the production cross sections for the synthesis of isotopes {sup 291-295,298}Lv using {sup 48}Ca projectile on {sup 243-247,250}Cm targets are calculated. Among these reactions, the reactions {sup 48}Ca + {sup 247}Cm → {sup 295}Lv and {sup 48}Ca + {sup 250}Cm → {sup 298}Lv have maximum production cross section in 3n (10.697 pb) and 4n (12.006 pb) channel, respectively. Our studies on the SHE Lv using the combinations {sup 48}Ca + {sup 245}Cm → {sup 293}Lv and {sup 48}Ca + {sup 248}Cm → {sup 296}Lv are compared with available experimental data and with other theoretical studies. Our studies are in agreement with experimental data and we hope that these studies will be a guide for the future experiments to synthesize the isotopes of Lv. (orig.)
Berger, Marcel
2010-01-01
Both classical geometry and modern differential geometry have been active subjects of research throughout the 20th century and lie at the heart of many recent advances in mathematics and physics. The underlying motivating concept for the present book is that it offers readers the elements of a modern geometric culture by means of a whole series of visually appealing unsolved (or recently solved) problems that require the creation of concepts and tools of varying abstraction. Starting with such natural, classical objects as lines, planes, circles, spheres, polygons, polyhedra, curves, surfaces,
Robinson, Gilbert de B
2011-01-01
This brief undergraduate-level text by a prominent Cambridge-educated mathematician explores the relationship between algebra and geometry. An elementary course in plane geometry is the sole requirement for Gilbert de B. Robinson's text, which is the result of several years of teaching and learning the most effective methods from discussions with students. Topics include lines and planes, determinants and linear equations, matrices, groups and linear transformations, and vectors and vector spaces. Additional subjects range from conics and quadrics to homogeneous coordinates and projective geom
Connes, Alain
1994-01-01
This English version of the path-breaking French book on this subject gives the definitive treatment of the revolutionary approach to measure theory, geometry, and mathematical physics developed by Alain Connes. Profusely illustrated and invitingly written, this book is ideal for anyone who wants to know what noncommutative geometry is, what it can do, or how it can be used in various areas of mathematics, quantization, and elementary particles and fields.Key Features* First full treatment of the subject and its applications* Written by the pioneer of this field* Broad applications in mathemat
DEFF Research Database (Denmark)
Olsen, M H; Hjerkinn, E; Wachtell, K
2003-01-01
Vascular hypertrophy and insulin resistance have been associated with abnormal left ventricular (LV) geometry in population studies. We wanted to investigate the influence of vascular hypertrophy and insulin resistance on LV hypertrophy and its function in patients with hypertension. In 89 patients...
Biodegradation of di-n-butyl phthalate by bacterial consortium LV-1 enriched from river sludge.
Directory of Open Access Journals (Sweden)
Yangyang Wang
Full Text Available A stable bacterial consortium (LV-1 capable of degrading di-n-butyl phthalate (DBP was enriched from river sludge. Community analysis revealed that the main families of LV-1 are Brucellaceae (62.78% and Sinobacteraceae (14.83%, and the main genera of LV-1 are Brucella spp. (62.78% and Sinobacter spp. (14.83%. The optimal pH and temperature for LV-1 to degrade DBP were pH 6.0 and 30°C, respectively. Inoculum size influenced the degradation ratio when the incubation time was < 24 h. The initial concentration of DBP also influenced the degradation rates of DBP by LV-1, and the degradation rates ranged from 69.0-775.0 mg/l/d in the first 24 h. Degradation of DBP was best fitted by first-order kinetics when the initial concentration was < 300 mg/l. In addition, Cd2+, Cr6+, and Zn2+ inhibited DBP degradation by LV-1 at all considered concentrations, but low concentrations of Pb2+, Cu2+, and Mn2+ enhanced DBP degradation. The main intermediates (mono-ethyl phthalate [MEP], mono-butyl phthalate [MBP], and phthalic acid [PA] were identified in the DBP degradation process, thus a new biochemical pathway of DBP degradation is proposed. Furthermore, LV-1 also degraded other phthalates with shorter ester chains (DMP, DEP, and PA.
Morley, Chris K.
2009-10-01
At least eight examples of large (5-35 km heave), low-angle normal faults (LANFs, 20°-30° dip) occur in the Cenozoic rift basins of Thailand and laterally pass into high-angle extensional fault systems. Three large-displacement LANFs are found in late Oligocene-Miocene onshore rift basins (Suphan Buri, Phitsanulok, and Chiang Mai basins), they have (1) developed contemporaneous with, or after the onset of, high-angle extension, (2) acted as paths for magma and associated fluids, and (3) impacted sedimentation patterns. Displacement on low-angle faults appears to be episodic, marked by onset of lacustrine conditions followed by axial progradation of deltaic systems that infilled the lakes during periods of low or no displacement. The Chiang Mai LANF is a low-angle (15°-25°), high-displacement (15-35 km heave), ESE dipping LANF immediately east of the late early Miocene Doi Inthanon and Doi Suthep metamorphic core complexes. Early Cenozoic transpressional crustal thickening followed by the northward motion of India coupled with Burma relative to east Burma and Thailand (˜40-30 Ma) caused migmatization and gneiss dome uplift in the late Oligocene of the core complex region, followed by LANF activity. LANF displacement lasted 4-6 Ma during the early Miocene and possibly transported a late Oligocene-early Miocene high-angle rift system 35 km east. Other LANFs in Thailand have lower displacements and no associated metamorphic core complexes. The three LANFs were initiated as low-angle faults, not by isostatic rotation of high-angle faults. The low-angle dips appear to follow preexisting low-angle fabrics (thrusts, shear zones, and other low-angle ductile foliations) predominantly developed during Late Paleozoic and early Paleogene episodes of thrusting and folding.
Indian Academy of Sciences (India)
mathematicians are trained to use very precise language, and so find it hard to simplify and state .... thing. If you take a plane on which there are two such triangles which enjoy the above ... within this geometry to simplify things if needed.
Geometry -----------~--------------RESONANCE
Indian Academy of Sciences (India)
Parallel: A pair of lines in a plane is said to be parallel if they do not meet. Mathematicians were at war ... Subsequently, Poincare, Klein, Beltrami and others refined non-. Euclidean geometry. ... plane divides the plane into two half planes and.
Removal of the liquid waste storage tank LV-2 in JRTF. Part 2. Removal works
International Nuclear Information System (INIS)
Kanayama, Fumihiko; Hagiya, Kazuaki; Sunaoshi, Mizuho; Muraguchi, Yoshinori; Satomi, Shinichi; Nemoto, Kouichi; Terunuma, Akihiro; Shiraishi, Kunio; Ito, Shinichi
2011-06-01
Dismantling activities of components in JAERI's Reprocessing Test Facility (JRTF) started from 1996 as a part of decommissioning of this facility. Removing out of a large liquid waste storage tank LV-2 as a whole tank from the annex building B without cutting in pieces to confirm safety and efficiency of this method started from 2006. After preparatory works, ceiling of LV-2 room was opened, and LV-2 was transferred. Useful data such as manpower, radiation control and waste amount through these works were collected, and work efficiency was analyzed by using of these data. (author)
La piattaforma POS/LV di Applanix nelle applicazioni di laser scanner cinematico
Domenico Santarsiero
2008-01-01
The Applanix POS/LV platform in cinematic laser scanner applicationsOn the 11th of march the GEOmedia editorial unit had the pleasure of hosting a technical meeting dedicated to the Applanix LANDMark new Position and Orientation System for Land Vehicles (POS/LV)field test. The meeting, which is part of an italian tour organized by Louis Nastro (Applanix Director of Land Products) and Terenzio Mariani (Sales manager for Italy), helped to test the functionalities of a complete POS/LV system equ...
Impact Study of Electric Vehicle (EV) Integration on Low Voltage (LV) Grids
DEFF Research Database (Denmark)
Wu, Qiuwei; Cha, Seung-Tae; Nielsen, Arne Hejde
2012-01-01
the single line diagram (SLD) of the LV grid. The demand profiles of end-users are determined by the end-user yearly consumption and avreaged demand profiles of different customer types in Denmark. Five charging scenarios have been tested using the developed LV grid. The first two charging scenarios are dumb....... The two charging power levels are 1 phase 16 A and 3 phase 16 A. The loading of the power components and voltage profile are analyzed to quantify the impact of the charging scenarios and charging power levels on LV grids....
Subclinical atherosclerosis in obese adolescents with normal left ventricular function.
Abdel-Wahab, Amina M; Atwa, Hoda A; El-Eraky, Azza Z; El-Aziz, Mohamed A
2011-09-01
To assess the impact of obesity on carotid intima media thickness and left ventricular (LV) mass in obese adolescents. The study included 52 obese adolescents (mean age 14.16+/-2.64 years) and 52 healthy adolescents who served as a control group (mean age 12+/-2.3 years), who were attended the outpatient clinic at Suez Canal University Hospital, Ismailia, Egypt. The study population was submitted for medical history, clinical examination, laboratory investigations (fasting blood sugar and lipid profile), and echocardiographic examination of LV mass and dimensions. Assessment of carotid intima-media thickness was carried out by using carotid duplex. All children had normal LV function. Obese adolescents had a significant increase in total cholesterol, triglyceride, LDL-C, and low HDL-C compared to the control group. Also, there was a significant increase in blood pressure, carotid intima media thickness, LV mass, and LV mass index. There was a significant correlation between BMI and dyslipidemia, blood pressure, carotid intima/media thickness, LV mass, and posterior wall thickness. Carotid intima-media thickness had a significant correlation with increased LDL-C and low HDL-C, blood pressure, LV mass, and posterior wall thickness. Obesity in childhood and adolescents is associated with subclinical atherosclerosis. Although obese children had no LV dysfunction, yet there are LV structure changes.
Gullian, Mariel; Rodríguez, Jenny
2002-01-01
Estudio de las cualidades inmunoestimulantes de nuevas bacterias probióticas asociadas al cultivo de LV Estudio de las cualidades inmunoestimulantes de nuevas bacterias probióticas asociadas al cultivo de LV
Impact of biogenic nanoscale metals Fe, Cu, Zn and Se on reproductive LV chickens
International Nuclear Information System (INIS)
Nguyen, Quy Khiem; Nguyen, Van Kien; Nguyen, Khac Thinh; Nguyen, Duy Dieu; Nguyen, Hoai Chau; Tran, Xuan Tin; Nguyen, Huu Cuong; Phung, Duc Tien
2015-01-01
Using biogenic nanoscale metals (Fe, Cu, ZnO, Se) to supplement into diet premix of reproductive LV (a Vietnamese Luong Phuong chicken breed) chickens resulted in certain improvement of poultry farming. The experimental data obtained showed that the farming indices depend mainly on the quantity of nanocrystalline metals which replaced the inorganic mineral component in the feed premix. All four experimental groups with different quantities of the replacement nano component grew and developed normally with livability reaching 91 to 94%, hen’s bodyweight at 38 weeks of age and egg weight ranged from 2.53–2.60 kg/hen and 50.86–51.55 g/egg, respectively. All these farming indices together with laying rate, egg productivity and chick hatchability peaked at group 5 with 25% of nanoscale metals compared to the standard inorganic mineral supplement, while feed consumption was lowest. The results also confirmed that nanocrystalline metals Fe, Cu, ZnO and Se supplemented to chicken feed were able to decrease inorganic minerals in the diet premixes at least four times, allowing animals to more effectively absorb feed minerals, consequently decreasing environmental pollution risks. (paper)
Petersen, Peter
2016-01-01
Intended for a one year course, this text serves as a single source, introducing readers to the important techniques and theorems, while also containing enough background on advanced topics to appeal to those students wishing to specialize in Riemannian geometry. This is one of the few Works to combine both the geometric parts of Riemannian geometry and the analytic aspects of the theory. The book will appeal to a readership that have a basic knowledge of standard manifold theory, including tensors, forms, and Lie groups. Important revisions to the third edition include: a substantial addition of unique and enriching exercises scattered throughout the text; inclusion of an increased number of coordinate calculations of connection and curvature; addition of general formulas for curvature on Lie Groups and submersions; integration of variational calculus into the text allowing for an early treatment of the Sphere theorem using a proof by Berger; incorporation of several recent results about manifolds with posit...
International Nuclear Information System (INIS)
Strominger, A.
1990-01-01
A special manifold is an allowed target manifold for the vector multiplets of D=4, N=2 supergravity. These manifolds are of interest for string theory because the moduli spaces of Calabi-Yau threefolds and c=9, (2,2) conformal field theories are special. Previous work has given a local, coordinate-dependent characterization of special geometry. A global description of special geometries is given herein, and their properties are studied. A special manifold M of complex dimension n is characterized by the existence of a holomorphic Sp(2n+2,R)xGL(1,C) vector bundle over M with a nowhere-vanishing holomorphic section Ω. The Kaehler potential on M is the logarithm of the Sp(2n+2,R) invariant norm of Ω. (orig.)
General Geometry and Geometry of Electromagnetism
Shahverdiyev, Shervgi S.
2002-01-01
It is shown that Electromagnetism creates geometry different from Riemannian geometry. General geometry including Riemannian geometry as a special case is constructed. It is proven that the most simplest special case of General Geometry is geometry underlying Electromagnetism. Action for electromagnetic field and Maxwell equations are derived from curvature function of geometry underlying Electromagnetism. And it is shown that equation of motion for a particle interacting with electromagnetic...
Ciarlet, Philippe G
2007-01-01
This book gives the basic notions of differential geometry, such as the metric tensor, the Riemann curvature tensor, the fundamental forms of a surface, covariant derivatives, and the fundamental theorem of surface theory in a selfcontained and accessible manner. Although the field is often considered a classical one, it has recently been rejuvenated, thanks to the manifold applications where it plays an essential role. The book presents some important applications to shells, such as the theory of linearly and nonlinearly elastic shells, the implementation of numerical methods for shells, and
Inferring microbial interaction networks from metagenomic data using SgLV-EKF algorithm.
Alshawaqfeh, Mustafa; Serpedin, Erchin; Younes, Ahmad Bani
2017-03-27
Inferring the microbial interaction networks (MINs) and modeling their dynamics are critical in understanding the mechanisms of the bacterial ecosystem and designing antibiotic and/or probiotic therapies. Recently, several approaches were proposed to infer MINs using the generalized Lotka-Volterra (gLV) model. Main drawbacks of these models include the fact that these models only consider the measurement noise without taking into consideration the uncertainties in the underlying dynamics. Furthermore, inferring the MIN is characterized by the limited number of observations and nonlinearity in the regulatory mechanisms. Therefore, novel estimation techniques are needed to address these challenges. This work proposes SgLV-EKF: a stochastic gLV model that adopts the extended Kalman filter (EKF) algorithm to model the MIN dynamics. In particular, SgLV-EKF employs a stochastic modeling of the MIN by adding a noise term to the dynamical model to compensate for modeling uncertainties. This stochastic modeling is more realistic than the conventional gLV model which assumes that the MIN dynamics are perfectly governed by the gLV equations. After specifying the stochastic model structure, we propose the EKF to estimate the MIN. SgLV-EKF was compared with two similarity-based algorithms, one algorithm from the integral-based family and two regression-based algorithms, in terms of the achieved performance on two synthetic data-sets and two real data-sets. The first data-set models the randomness in measurement data, whereas, the second data-set incorporates uncertainties in the underlying dynamics. The real data-sets are provided by a recent study pertaining to an antibiotic-mediated Clostridium difficile infection. The experimental results demonstrate that SgLV-EKF outperforms the alternative methods in terms of robustness to measurement noise, modeling errors, and tracking the dynamics of the MIN. Performance analysis demonstrates that the proposed SgLV-EKF algorithm
Efficient Control of Energy Storage for Increasing the PV Hosting Capacity of LV Grids
DEFF Research Database (Denmark)
Hashemi Toghroljerdi, Seyedmostafa; Østergaard, Jacob
2016-01-01
grid is usually limited by overvoltage, and the efficient control of distributed electrical energy storage systems (EESSs) can considerably increase this capacity. In this paper, a new control approach based on the voltage sensitivity analysis is proposed to prevent overvoltage and increase the PV......Photovoltaic (PV) systems are among the renewable sources that electrical energy systems are adopting with increasing frequency. The majority of already-installed PV systems are decentralized units that are usually connected to lowvoltage (LV) distribution grids. The PV hosting capacity of an LV...... hosting capacity of LV grids by determining dynamic set points for EESS management. The method has the effectiveness of central control methods and can effectively decrease the energy storage required for overvoltage prevention, yet it eliminates the need for a broadband and fast communication. The net...
EV Charging Facilities and Their Application in LV Feeders with Photovoltaics
DEFF Research Database (Denmark)
Marra, Francesco; Yang, Guangya; Træholt, Chresten
2013-01-01
Low-voltage (LV) grid feeders with high penetration of photovoltaics (PVs) are often affected by voltage magnitude problems. To solve such issues, previous research has shown that reactive power methods, active power curtailment and grid reinforcement can be used for voltage support, yet showing...... several limits. We introduce the use of electric vehicle (EV) public charging stations with energy storage system (ESS) as a solution for voltage regulation in LV feeders with PV. A novel method is proposed to determine the ESS charging load required for voltage regulation and compare the results...... for the different locations in the feeder. With time-series simulations, we quantify the energy size required for a station ESS. A Belgian LV residential grid, modeled using real PV generation and load profiles, is used as case study. The method and simulation results show the effectiveness of using public EV...
La piattaforma POS/LV di Applanix nelle applicazioni di laser scanner cinematico
Directory of Open Access Journals (Sweden)
Domenico Santarsiero
2008-03-01
Full Text Available The Applanix POS/LV platform in cinematic laser scanner applicationsOn the 11th of march the GEOmedia editorial unit had the pleasure of hosting a technical meeting dedicated to the Applanix LANDMark new Position and Orientation System for Land Vehicles (POS/LVfield test. The meeting, which is part of an italian tour organized by Louis Nastro (Applanix Director of Land Products and Terenzio Mariani (Sales manager for Italy, helped to test the functionalities of a complete POS/LV system equipped with a laser and an imaging acquisition software installed on board of a SUV.
Akopyan, A V
2007-01-01
The book is devoted to the properties of conics (plane curves of second degree) that can be formulated and proved using only elementary geometry. Starting with the well-known optical properties of conics, the authors move to less trivial results, both classical and contemporary. In particular, the chapter on projective properties of conics contains a detailed analysis of the polar correspondence, pencils of conics, and the Poncelet theorem. In the chapter on metric properties of conics the authors discuss, in particular, inscribed conics, normals to conics, and the Poncelet theorem for confoca
Integration of SPICE with TEK LV500 ASIC Design Verification System
Directory of Open Access Journals (Sweden)
A. Srivastava
1996-01-01
Full Text Available The present work involves integration of the simulation stage of design of a VLSI circuit and its testing stage. The SPICE simulator, TEK LV500 ASIC Design Verification System, and TekWaves, a test program generator for LV500, were integrated. A software interface in ‘C’ language in UNIX ‘solaris 1.x’ environment has been developed between SPICE and the testing tools (TekWAVES and LV500. The function of the software interface developed is multifold. It takes input from either SPICE2G.6 or SPICE 3e.1. The output generated by the interface software can be given as an input to either TekWAVES or LV500. A graphical user interface has also been developed with OPENWlNDOWS using Xview tool kit on SUN workstation. As an example, a two phase clock generator circuit has been considered and usefulness of the software demonstrated. The interface software could be easily linked with VLSI design such as MAGIC layout editor.
77 FR 21620 - Notice of the Buy America Waiver Request for Vossloh 101-LV Concrete Ties
2012-04-10
... the Buy America Waiver Request for Vossloh 101-LV Concrete Ties AGENCY: Federal Railroad... concrete ties, which contain certain components not manufactured in the United States. In furtherance of... concrete ties. FRA has received this request from the four States for the following projects: (a) The...
Choloniewski, J.; Valentijn, E. A.
A new method for the determination of the extinction in the Galaxy is proposed. The method uses surface brightnesses of external galaxies in the B and R-bands. The observational data have been taken from the ESO-LV galaxy catalog. As a first application of our model we derive the ratio of R-band to
Current distribution in LV networks during 1-phase MV short-circuit
Waes, van J.B.M.; Provoost, F.; Merwe, van der J.; Cobben, J.F.G.; Deursen, van A.P.J.; van Riet, M.J.M.; Laan, van der P.C.T.
2000-01-01
This paper describes the consequences of a fault in a medium voltage network on the grounding systems at the LV-side. To study the current distribution and to verify the models, we deliberately introduced one phase to ground faults in the 10 kV floating MV network. The selected site was the end of a
La piattaforma POS/LV di Applanix nelle applicazioni di laser scanner cinematico
Directory of Open Access Journals (Sweden)
Domenico Santarsiero
2008-03-01
field test. The meeting, which is part of an italian tour organized by Louis Nastro (Applanix Director of Land Products and Terenzio Mariani (Sales manager for Italy, helped to test the functionalities of a complete POS/LV system equipped with a laser and an imaging acquisition software installed on board of a SUV.
Distributed generation in the Dutch LV network - self-supporting residential area
Mes, M.; Vanalme, G.M.A.; Myrzik, J.M.A.; Bongaerts, M.; Verbong, G.P.J.; Kling, W.L.
2008-01-01
A self-supporting residential area is seen as an alternative operational approach of power supply in low voltage (LV) networks. The intention of the new approach is to exploit the advantages of distributed generation (DG) and avoid the difficulties, that come with DG when implemented in the
Haque, A.N.M.M.; Nguyen, H.P.; Vo, T.; Bliek, F.W.
2016-01-01
Rapid proliferation of the distributed energy resources (DERs) poses operational challenges for the low-voltage (LV) distribution networks in terms of thermal overloading of the network assets along with voltage limit violations at the connection points. A number of market-based and direct control
Coordinated control to mitigate over voltage and under voltage in LV networks
Viyathukattuva Mohamed Ali, M.M.; Nguyen, H.P.; Cobben, J.F.G.
2016-01-01
Increasing penetration of distributed renewable energy resources (DRES) and smart loads into the LV network lead to new power quality challenges. Important power quality challenges are overvoltage and undervoltage. A number of solutions are already developed to mitigate these voltage variations. In
Silva, Alessandro
1993-01-01
The papers in this wide-ranging collection report on the results of investigations from a number of linked disciplines, including complex algebraic geometry, complex analytic geometry of manifolds and spaces, and complex differential geometry.
Eisenhart, Luther Pfahler
2005-01-01
This concise text by a prominent mathematician deals chiefly with manifolds dominated by the geometry of paths. Topics include asymmetric and symmetric connections, the projective geometry of paths, and the geometry of sub-spaces. 1927 edition.
International Nuclear Information System (INIS)
Gurevich, L.Eh.; Gliner, Eh.B.
1978-01-01
Problems of investigating the Universe space-time geometry are described on a popular level. Immediate space-time geometries, corresponding to three cosmologic models are considered. Space-time geometry of a closed model is the spherical Riemann geonetry, of an open model - is the Lobachevskij geometry; and of a plane model - is the Euclidean geometry. The Universe real geometry in the contemporary epoch of development is based on the data testifying to the fact that the Universe is infinitely expanding
Resistance to RadLV-induced leukemia: non-participation of splenic natural killer cells
International Nuclear Information System (INIS)
St-Pierre, Y.; Hugo, P.; Lemieux, S.; Lussier, G.; Potworowski, E.F.
1988-01-01
The phenotypic expression of genetically determined resistance to radiation leukemia virus (RadLV)-induced leukemia in mice has been shown to reside in the bone marrow. Because the bone marrow contains precursors of natural killer (NK) cells, known to play a role in retrovirally induced infections, and because these cells have been suggested as participating in resistance to radiation-induced leukemia, it was pertinent to establish whether their levels differed in strains of mice susceptible and resistant to leukemia. We therefore tested splenic NK cell levels in C57BL/Ka (susceptible) and B10.A(5R) (resistant) mice before viral inoculation, immediately after viral inoculation, and throughout the preleukemic period and showed that they were not different. This indicates that splenic NK cell levels have no bearing on the resistance to RadLV-induced leukemia and that other immune or non-immune mechanisms must be sought
Energy Technology Data Exchange (ETDEWEB)
Venegas Salgado, Saul; Arredondo Fragoso, Jesus; Ramirez Silva, German; Flores Armenta, Magaly; Ramirez Montes, Miguel [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)]. E-mail: magaly.flores@cfe.gob.mx
2006-07-15
From September through December 2004 a seismic monitoring in the Las Tres Virgenes, BCS, geothermal field was carried out simultaneously with the acid stimulation of wells LV-4 and LV-13. The seismic network had four digital seismographs and recorded 174 local seismic events, 131 regional ones and many more volcanic signals at seismic station TV20 during the acid stimulation. Additionally, 37 seismic events were located, 22 of them inside the most important geothermal zone at depths between 0.4 and 4 km with typically low magnitudes (0.7 to 2.2 Md). Two relevant zones were determined: Zone A related to the El Volcan fault system and Zone B related to injection well LV-8. In Zone A the well-induction stage and the operation start of the wells LV-4 and LV-13 after acidification on October 30 and November 17, 2004, increased seismic activity to a maximum of 12 daily events in early December. When the two wells in Zone B were cooled before the acidification, the seismic events recorded there increased to a maximum of 6 daily events on October 2, and then decreased. Also in Zone B the seismic activity increased after well-induction and the start of well production once they were acidified, recording up to 11 daily events in late November. According to the seismic distribution, we may conclude that the most active fault systems are El Volcan and El Viejo. New proposals for well locations in the field are supported by these results. [Spanish] De septiembre a diciembre de 2004 se realizo un estudio de monitoreo sismico en el campo geotermico de Las Tres Virgenes, BCS, simultaneamente con las estimulaciones acidas de los pozos LV-4 y LV-13. Se utilizo una red sismica conformada por cuatro sismografos digitales, logrando registrar en la estacion sismica TV20 un total de 174 sismos locales, 131 sismos regionales y muchas mas senales de tipo volcanico, durante el periodo del monitoreo de la estimulacion acida. Ademas, se localizaron un total de 37 sismos, de los cuales 22 se
Energy Technology Data Exchange (ETDEWEB)
Song, J.; Shi, Z.; Yang, Y.; Shi, W.; Wei, H.; Zhai, S.; Xie, H. [Taiyuan University of Technology, Taiyuan (China)
2001-02-01
The overcurrent fault characteristics in underground LV cable distribution networks is analysed and the fundamental principle of overcurrent protective system is described in this paper. The emphasis is paid to the determination of the characteristic curves of phase-sensitive symmetrical short-circuit protection, the design of negative-sequence current filter and the definition of the mathematical model of overload. Besides, the hardware block diagram and the software flowchart of the protective system, which is controlled by a single chip microcomputer, is also introduced in the paper. The protective system was tested before being applied to the underground LV distribution networks. The results obtained are in conformity with the design specification. It has been verified that the protective distance is extended and the protective sensitivity is improved with the protective system. The field experience has shown that the protective system is stable and reliable, and will be of great application value in the mining industry. 7 refs., 5 figs., 2 tabs.
Drift of IBL LV current and its consequence in IBL distortion
The ATLAS collaboration
2015-01-01
The low voltage (LV) current of the IBL modules had been stable since the beginning of the Run2 until the middle of September 2015, but it has been unstable since then (Figure 1). A clear relation is observed between the current rise-up and the total radiation doze (TID) increase, which is considered to be the TID effect reported in . A shutdown of more than 29 hour on October 6 recovered the current largely (Figure 2). With the change of the LV current, the temperature of IBL modules also changes (Figure 3). The change of the thermo-mechanical condition of the IBL resulted in the change of the IBL distortion magnitude, and a clear relation between the module temperature and the distortion magnitude is observed (Figure 4). Through the duration presented in this series of plots, the cooling set temperature of the IBL was kept at -10℃.
International Nuclear Information System (INIS)
Luo Zhiyuan; Wang Guangjin; Zhou Bin
2007-01-01
A LV electrical penetration assembly with perfusion sealing conductor feedthrough module was developed, which can be used for the connection of internal and external cables through the wall of the research reactor workshop. The LV electrical penetration assembly was combined with several independent modules. The maintenance and replacement of the assembly can be easily done in service. The sealing of conductor feedthrough module was achieved with the perfusion of self-extinguishing epoxy. The leakage between the conductor feedthrough module and the end plate module was blocked with rubber rings. The result of the leakage test and the electrical performance test for the samples of conductor feedthrough module satisfied the requirement of research reactor. The structure of the new electrical penetration assembly is simple and compact. It can be manufactured with mature technology and cost low price. The performance of the assembly is steady. It can be used widely in research reactors. (authors)
Analysis of critical operating conditions for LV distribution networks with microgrids
Zehir, M. A.; Batman, A.; Sonmez, M. A.; Font, A.; Tsiamitros, D.; Stimoniaris, D.; Kollatou, T.; Bagriyanik, M.; Ozdemir, A.; Dialynas, E.
2016-11-01
Increase in the penetration of Distributed Generation (DG) in distribution networks, raises the risk of voltage limit violations while contributing to line losses. Especially in low voltage (LV) distribution networks (secondary distribution networks), impacts of active power flows on the bus voltages and on the network losses are more dominant. As network operators must meet regulatory limitations, they have to take into account the most critical operating conditions in their systems. In this study, it is aimed to present the impact of the worst operation cases of LV distribution networks comprising microgrids. Simulation studies are performed on a field data-based virtual test-bed. The simulations are repeated for several cases consisting different microgrid points of connection with different network loading and microgrid supply/demand conditions.
‘Lv Peng and his Chinese Art History in Operation, since 1986’
Directory of Open Access Journals (Sweden)
Joshua Gong
2014-06-01
Full Text Available Lv Peng is one of the most influential contemporary Chinese art historians, who began publishing his work in 1986 and introduced various innovative approaches and methods to the field. Even though his work gained momentum in the field, his totalising and continually-revised publication scheme have come under incessant criticism from friends and rivals alike. This article is an attempt at surveying Lv Peng’s oeuvre, while testifying to the value of his art history writings by making his various approaches more legible and systematic. His most popular publications as well as a few projects that are still in progress will be analysed for a more comprehensive understanding of his operational art history.
Voltage unbalance mitigation in LV networks using three-phase PV systems
DEFF Research Database (Denmark)
Garcia Bajo, Cristina; Hashemi Toghroljerdi, Seyedmostafa; Bækhøj Kjær, Søren
2015-01-01
In this paper a new method is proposed to mitigate voltage unbalance caused by single-phase solar inverters in low voltage (LV) networks. The method is based on uneven reactive power absorption and injection by three-phase solar inverters. Independent control of each phase is performed to achieve...... this uneven injection. The average values of phase voltages at the connection points of the photovoltaic (PV) inverters are used as the references for the balancing algorithm. Voltage unbalance mitigation is achieved by use of this method in different scenarios with variable three-phase and single......-phase inverters penetration in a realistic LV grid. In addition, the overvoltage is reduced by using this method....
A New Protection System for Islanding Detection in LV Distribution Systems
Directory of Open Access Journals (Sweden)
Anna Rita Di Fazio
2015-04-01
Full Text Available The growth of penetration of Distributed Generators (DGs is increasing the risk of unwanted islanded operation in Low Voltage (LV distribution systems. In this scenario, the existing anti-islanding protection systems, installed at the DG premises and based on classical voltage and frequency relays, are no longer effective, especially in the cases of islands characterized by a close match between generation and load. In this paper, a new protection system for islanding detection in LV distribution systems is proposed. The classical voltage and frequency relays in the DG interface protections are enriched with an innovative Smart Islanding Detector, which adopts a new passive islanding detection method. The aim is to keep the advantages of the classical relays while overcoming the problem of their limited sensitivity in detecting balanced islands. In the paper, to define the requirements of the anti-islanding protection system, the events causing the islanded operation of the LV distribution systems are firstly identified and classified. Then, referring to proposed protection system, its architecture and operation are described and, eventually, its performance is analyzed and validated by experimental laboratory tests, carried out with a hardware-in-the-loop technique.
Quantifying grain shape with MorpheoLV: A case study using Holocene glacial marine sediments
Charpentier, Isabelle; Staszyc, Alicia B.; Wellner, Julia S.; Alejandro, Vanessa
2017-06-01
As demonstrated in earlier works, quantitative grain shape analysis has revealed to be a strong proxy for determining sediment transport history and depositional environments. MorpheoLV, devoted to the calculation of roughness coefficients from pictures of unique clastic sediment grains using Fourier analysis, drives computations for a collection of samples of grain images. This process may be applied to sedimentary deposits assuming core/interval/image archives for the storage of samples collected along depth. This study uses a 25.8 m jumbo piston core, NBP1203 JPC36, taken from a 100 m thick sedimentary drift deposit from Perseverance Drift on the northern Antarctic Peninsula continental shelf. Changes in ocean and ice conditions throughout the Holocene recorded in this sedimentary archive can be assessed by studying grain shape, grain texture, and other proxies. Ninety six intervals were sampled and a total of 2319 individual particle images were used. Microtextures of individual grains observed by SEM show a very high abundance of authigenically precipitated silica that obscures the original grain shape. Grain roughness, computed along depth with MorpheoLV, only shows small variation confirming the qualitative observation deduced from the SEM. Despite this, trends can be seen confirming the reliability of MorpheoLV as a tool for quantitative grain shape analysis.
Quantifying grain shape with MorpheoLV: A case study using Holocene glacial marine sediments
Directory of Open Access Journals (Sweden)
Charpentier Isabelle
2017-01-01
Full Text Available As demonstrated in earlier works, quantitative grain shape analysis has revealed to be a strong proxy for determining sediment transport history and depositional environments. MorpheoLV, devoted to the calculation of roughness coefficients from pictures of unique clastic sediment grains using Fourier analysis, drives computations for a collection of samples of grain images. This process may be applied to sedimentary deposits assuming core/interval/image archives for the storage of samples collected along depth. This study uses a 25.8 m jumbo piston core, NBP1203 JPC36, taken from a ~100 m thick sedimentary drift deposit from Perseverance Drift on the northern Antarctic Peninsula continental shelf. Changes in ocean and ice conditions throughout the Holocene recorded in this sedimentary archive can be assessed by studying grain shape, grain texture, and other proxies. Ninety six intervals were sampled and a total of 2319 individual particle images were used. Microtextures of individual grains observed by SEM show a very high abundance of authigenically precipitated silica that obscures the original grain shape. Grain roughness, computed along depth with MorpheoLV, only shows small variation confirming the qualitative observation deduced from the SEM. Despite this, trends can be seen confirming the reliability of MorpheoLV as a tool for quantitative grain shape analysis.
Directory of Open Access Journals (Sweden)
Shijun Xie
Full Text Available White spot syndrome virus (WSSV is a major pathogen in shrimp cultures. The interactions between viral proteins and their receptors on the surface of cells in a frontier target tissue are crucial for triggering an infection. In this study, a yeast two-hybrid (Y2H library was constructed using cDNA obtained from the stomach and gut of Litopenaeus vannamei, to ascertain the role of envelope proteins in WSSV infection. For this purpose, VP37 was used as the bait in the Y2H library screening. Forty positive clones were detected after screening. The positive clones were analyzed and discriminated, and two clones belonging to the peritrophin family were subsequently confirmed as genuine positive clones. Sequence analysis revealed that both clones could be considered as the same gene, LV-peritrophin (LvPT. Co-immunoprecipitation confirmed the interaction between LvPT and VP37. Further studies in the Y2H system revealed that LvPT could also interact with other WSSV envelope proteins such as VP32, VP38A, VP39B, and VP41A. The distribution of LvPT in tissues revealed that LvPT was mainly expressed in the stomach than in other tissues. In addition, LvPT was found to be a secretory protein, and its chitin-binding ability was also confirmed.
Directory of Open Access Journals (Sweden)
Laura S. Levy
2011-09-01
Full Text Available Detailed analysis has been performed over many years of a geographic and temporal cohort of cats naturally infected with feline leukemia virus (FeLV. Molecular analysis of FeLV present in the diseased tissues and application of those viruses to experimental systems has revealed unique isolates with distinctive disease potential, previously uncharacterized virus-receptor interactions, information about the role of recombinant viruses in disease induction, and novel viral and cellular oncogenes implicated in pathogenesis, among other findings. The studies have contributed to an understanding of the selective forces that lead to predominance of distinctive FeLV isolates and disease outcomes in a natural population.
Variable geometry Darrieus wind machine
Pytlinski, J. T.; Serrano, D.
1983-08-01
A variable geometry Darrieus wind machine is proposed. The lower attachment of the blades to the rotor can move freely up and down the axle allowing the blades of change shape during rotation. Experimental data for a 17 m. diameter Darrieus rotor and a theoretical model for multiple streamtube performance prediction were used to develop a computer simulation program for studying parameters that affect the machine's performance. This new variable geometry concept is described and interrelated with multiple streamtube theory through aerodynamic parameters. The computer simulation study shows that governor behavior of a Darrieus turbine can not be attained by a standard turbine operating within normally occurring rotational velocity limits. A second generation variable geometry Darrieus wind turbine which uses a telescopic blade is proposed as a potential improvement on the studied concept.
Strauss, Margit; Kouraki, Kleopatra; Skarlos, Alexandros; Zahn, Ralf; Kleemann, Thomas
2013-06-01
The wearable cardioverter-defibrillator (WCD) is indicated in patients who are considered to be at temporarily high risk for sudden cardiac death (SCD), when an implantable defibrillator is not yet clearly indicated. We report the case of a 41-year-old patient with a newly diagnosed severely reduced left ventricular (LV) function for suspected myocarditis and repeated nonsustained ventricular tachycardia (VT). This patient was supplied with a WCD who came back to the hospital 4 weeks after discharge with an electrical storm and adequate discharge of the WCD. After application of amiodarone, no further arrhythmias were detected during intrahospital course. For further risk stratification, we performed a magnetic field imaging (MFI), that was reported to be useful in risk assessment of SCD in patients with ischemic cardiomyopathy. This measurement showed a normal result, but we decided to give an implantable cardioverter-defibrillator (ICD) to the patient. During a follow-up of 1 year, no further arrhythmias occurred. With this case, we report the efficacy of a WCD, which is a novel tool in patients at temporarily high risk of SCD and we report a novel method of risk stratification in patients with a high risk of SCD.
Directory of Open Access Journals (Sweden)
Lijia Wang
2015-01-01
Full Text Available CMR quantification of LV chamber volumes typically and manually defines the basal-most LV, which adds processing time and user-dependence. This study developed an LV segmentation method that is fully automated based on the spatiotemporal continuity of the LV (LV-FAST. An iteratively decreasing threshold region growing approach was used first from the midventricle to the apex, until the LV area and shape discontinued, and then from midventricle to the base, until less than 50% of the myocardium circumference was observable. Region growth was constrained by LV spatiotemporal continuity to improve robustness of apical and basal segmentations. The LV-FAST method was compared with manual tracing on cardiac cine MRI data of 45 consecutive patients. Of the 45 patients, LV-FAST and manual selection identified the same apical slices at both ED and ES and the same basal slices at both ED and ES in 38, 38, 38, and 41 cases, respectively, and their measurements agreed within -1.6±8.7 mL, -1.4±7.8 mL, and 1.0±5.8% for EDV, ESV, and EF, respectively. LV-FAST allowed LV volume-time course quantitatively measured within 3 seconds on a standard desktop computer, which is fast and accurate for processing the cine volumetric cardiac MRI data, and enables LV filling course quantification over the cardiac cycle.
Estimation of Maximum Allowable PV Connection to LV Residential Power Networks
DEFF Research Database (Denmark)
Demirok, Erhan; Sera, Dezso; Teodorescu, Remus
2011-01-01
Maximum photovoltaic (PV) hosting capacity of low voltage (LV) power networks is mainly restricted by either thermal limits of network components or grid voltage quality resulted from high penetration of distributed PV systems. This maximum hosting capacity may be lower than the available solar...... potential of geographic area due to power network limitations even though all rooftops are fully occupied with PV modules. Therefore, it becomes more of an issue to know what exactly limits higher PV penetration level and which solutions should be engaged efficiently such as over sizing distribution...
The B → D*lv form factor at zero recoil
International Nuclear Information System (INIS)
Simone, J.N.; Hashimoto, S.; El-Khadra, A.X.; Kronfeld, A.S.; Mackenzie, P.B.; Ryan, S.M.
2000-01-01
We describe a model independent lattice QCD method for determining the deviation from unity for h A1 (1), the B → D*lv form factor at zero recoil. We extend the double ratio method previously used to determine the B → Dlv form factor. The bulk of statistical and systematic errors cancel in the double ratios we consider, yielding form factors which promise to reduce present theoretical uncertainties in the determination of parallel V cb parallel. We present results from a prototype calculation at a single lattice spacing corresponding to β = 5.7
Voltage regulation in LV grids by coordinated volt-var control strategies
DEFF Research Database (Denmark)
Juamperez Goñi, Miguel Angel; Yang, Guangya; Kjær, Søren Bækhøj
2014-01-01
in a representative LV network in Bornholm Island using a multi-objective genetic algorithm. The approach is to increase the reactive power contribution of the inverters closest to the transformer during overvoltage conditions. Two standard reactive power control concepts, cosΦ(P) and Q(U), are simulated and compared...... in terms of network power losses and voltage level along the feeder. As a practical implementation, a reconfigurable hardware is used for developing a testing platform based on real-time measurements to regulate the reactive power level. The proposed testing platform has been developed within PVNET...
Meyer, Walter J
2006-01-01
Meyer''s Geometry and Its Applications, Second Edition, combines traditional geometry with current ideas to present a modern approach that is grounded in real-world applications. It balances the deductive approach with discovery learning, and introduces axiomatic, Euclidean geometry, non-Euclidean geometry, and transformational geometry. The text integrates applications and examples throughout and includes historical notes in many chapters. The Second Edition of Geometry and Its Applications is a significant text for any college or university that focuses on geometry''s usefulness in other disciplines. It is especially appropriate for engineering and science majors, as well as future mathematics teachers.* Realistic applications integrated throughout the text, including (but not limited to): - Symmetries of artistic patterns- Physics- Robotics- Computer vision- Computer graphics- Stability of architectural structures- Molecular biology- Medicine- Pattern recognition* Historical notes included in many chapters...
Indian Academy of Sciences (India)
algebraic geometry but also in related fields like number theory. ... every vector bundle on the affine space is trivial. (equivalently ... les on a compact Riemann surface to unitary rep- ... tial geometry and topology and was generalised in.
International Nuclear Information System (INIS)
Sloane, Peter
2007-01-01
We adapt the spinorial geometry method introduced in [J. Gillard, U. Gran and G. Papadopoulos, 'The spinorial geometry of supersymmetric backgrounds,' Class. Quant. Grav. 22 (2005) 1033 [ (arXiv:hep-th/0410155)
Energy Technology Data Exchange (ETDEWEB)
Sloane, Peter [Department of Mathematics, King' s College, University of London, Strand, London WC2R 2LS (United Kingdom)
2007-09-15
We adapt the spinorial geometry method introduced in [J. Gillard, U. Gran and G. Papadopoulos, 'The spinorial geometry of supersymmetric backgrounds,' Class. Quant. Grav. 22 (2005) 1033 [ (arXiv:hep-th/0410155)
Biocorrosion of 316LV steel used in oral cavity due to Desulfotomaculum nigrificans bacteria.
Mystkowska, Joanna; Ferreira, Jose A; Leszczyńska, Katarzyna; Chmielewska, Sylwia; Dąbrowski, Jan Ryszard; Wieciński, Piotr; Kurzydłowski, Krzysztof Jan
2017-01-01
Corrosion processes of metallic biomaterials in the oral cavity pose a significant limitation to the life and reliable functioning of dental materials. In this article, the influence of environment bacteria Desulfotomaculum nigrificans sulfate reducing bacteria on the corrosion processes of 316LV steel was assessed. After 14 and 28 days of contact of the material with the bacterial environment, the surfaces of the tested biomaterial were observed by means of confocal scanning laser microscopy, and their chemical composition was studied using X-Ray Photoelectron Spectrometry and a scanning transmission electron microscopy. Corrosive changes, the presence of sulfur (with atomic concentration of 0.5%) on the surface of the biomaterial and the presence of a thin oxide layer (thickness of ∼20 nm) under the surface of the steel were observed. This corrosion layer with significant size reduction of grains was characterized by an increased amount of oxygen (18% mas., p < 0.001) in comparison to untreated 316LV steel (where oxygen concentration - 10% mas.). Image analysis conducted using APHELION software indicated that corrosion pits took up ∼2.8% of the total tested surface. The greatest number of corrosion pits had a surface area within the range of 100-200 μm 2 . © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 222-229, 2017. © 2015 Wiley Periodicals, Inc.
Geometry essentials for dummies
Ryan, Mark
2011-01-01
Just the critical concepts you need to score high in geometry This practical, friendly guide focuses on critical concepts taught in a typical geometry course, from the properties of triangles, parallelograms, circles, and cylinders, to the skills and strategies you need to write geometry proofs. Geometry Essentials For Dummies is perfect for cramming or doing homework, or as a reference for parents helping kids study for exams. Get down to the basics - get a handle on the basics of geometry, from lines, segments, and angles, to vertices, altitudes, and diagonals Conque
Arithmetic noncommutative geometry
Marcolli, Matilde
2005-01-01
Arithmetic noncommutative geometry denotes the use of ideas and tools from the field of noncommutative geometry, to address questions and reinterpret in a new perspective results and constructions from number theory and arithmetic algebraic geometry. This general philosophy is applied to the geometry and arithmetic of modular curves and to the fibers at archimedean places of arithmetic surfaces and varieties. The main reason why noncommutative geometry can be expected to say something about topics of arithmetic interest lies in the fact that it provides the right framework in which the tools of geometry continue to make sense on spaces that are very singular and apparently very far from the world of algebraic varieties. This provides a way of refining the boundary structure of certain classes of spaces that arise in the context of arithmetic geometry, such as moduli spaces (of which modular curves are the simplest case) or arithmetic varieties (completed by suitable "fibers at infinity"), by adding boundaries...
Benazepril inhibited the NF-κB and TGF-β networking on LV hypertrophy in rats.
Yan, Shi-Hai; Zhao, Ning-Wei; Zhu, Xuan-Xuan; Wang, Qiong; Wang, Hai-Dan; Fu, Rui; Sun, Yuan; Li, Qi-Yi
2013-05-01
Benazepril, an angiotensin-converting enzyme (ACE) inhibitor, has been used to treat hypertension, congestive heart failure, and chronic renal failure. However, its biological activity and mechanism of action in inflammation are not fully identified. The present study was designed to determine the in vivo anti-inflammatory effects of benazepril on LV hypertrophy in rats. LV hypertrophy was produced in rats by abdominal aortic coarctation. They were then divided into the following groups: sham operation; LV hypertrophy; LV hypertrophy+benazepril (1mg/kg in a gavage, once a day for 4 weeks). Both morphological assays (hemodynamic and hemorheological measurement; LV hypertrophy assessment), and molecular assays (protein levels of Collagen type I/III, TNF-α and VCAM-1; TGF-β gene expression; NF-κB or Smad activation; intracellular ROS production) were performed. The following effects were observed in rats treated with benazepril: (1) marked improvements in hemodynamic and hemorheological parameters; (2) significant reductions in LV hypertrophy, dilatation and fibrosis; (3) significantly attenuated protein levels of Collagen type I/III, TGF-β, TNF-α and VCAM-1, NF-κB or Smad activation, as well as intracellular ROS production. These results suggest that the anti-inflammatory properties of benazepril may be ascribed to their down-regulation of both NF-κB and TGF-β signaling pathways by acting on the intracellular ROS production in rats with LV hypertrophy, thus supporting the use of benazepril as an anti-inflammatory agent. Copyright © 2013 Elsevier B.V. All rights reserved.
Current status of the Citrus leprosis virus (CiLV -C and its vector Brevipalpus phoenicis (Geijskes
Directory of Open Access Journals (Sweden)
Guillermo León M
2012-08-01
Full Text Available The Citrus leprosis virus CiLV-C is a quarantine disease of economic importance. Over the past 15 years, this disease has spread to several countries of Central and South America. Colombia has about 45,000 hectares of citrus planted with an annual production of 750,000 tonnes. The CiLV-C has only been detected in the departments of Meta, Casanare and recently Tolima. Meta has 4,300 hectares representing 10% of the national cultivated area, and Casanare, where CiLV-C appeared in 2004, has no more than 500 ha planted with citrus. The presence of the Citrus leprosis virus in Colombia could affect the international market for citrus, other crops and ornamental plants with the United States and other countries without the disease. The false spider mite Brevipalpus phoenicis (Geijskes (Acari: Tenuipalpidae is the main vector of the CiLV-C. Disease management is based on control programs of the vector and diminishing host plants. Chemical mite control is expensive, wasteful and generates resistance to different acaricides. This paper provides basic information on CiLV-C and its vector, advances in diagnosis and methods to control the disease and prevention of its spread
BezRindas.lv biļešu tirdzniecības Android lietotne
Upītis, Reinis
2014-01-01
Kvalifikācijas darbā tiek aprakstīta autobusu biļešu tirdzniecības lietotne, kas ir paredzēta viedtālruņiem ar Android operētājsistēmu. Mobilā lietotne paredzēta kā papildinājums jau esošam servisam – Bezrindas.lv. Aprakstītās sistēmas izveide atvieglotu biļešu iegādi lietotājiem, kas to vēlētos darīt ar saviem viedtālruņiem.
Efficient Control of Active Transformers for Increasing the PV Hosting Capacity of LV Grids
DEFF Research Database (Denmark)
Hashemi Toghroljerdi, Seyedmostafa; Østergaard, Jacob; Degner, Thomas
2016-01-01
. The potential interferences between the operation of active transformers and the reactive power absorption by PV inverters are investigated, and a voltage droop control approach is proposed for the efficient control of these transformers during high PV generation periods. The proposed method can potentially...... increase the PV hosting capacity of the grid, while eliminating the need for a complex and centralized controller. The voltages of specific locations or the grid state estimations provide adequate data for adjustments of the droop parameters. The simulations and field test results associated...... with the implementation of the proposed method to a newly developed active LV grid with high PV penetration in Felsberg, Germany, confirm the efficiency of the proposed method....
Evolution of the Nova Vulpeculae no.1 1968 (LV Vul) spectrum after the maximum brightness
International Nuclear Information System (INIS)
Andrijya, I.; Antipova, L.I.; Babaev, M.B.; AN Azerbajdzhanskoj SSR, Baku. Shemakhinskaya Astrofizicheskaya Observatoriya)
1986-01-01
The analysis of the spectral evolution of LV Vulpeculae 1968 after the maximum brightness was carried out. It is shown that the pre-maximum spectrum was replaced by the principal one in less than 24sup(h). The diffuse enhanced scectrum and the Orion one existed already when the Nova brightness has decreased only by 0.4sup(m) and 0.5sup(m) respectively. The radial velocities of the Orion spectrum coincided with those of the diffuse enhanced one during the total observational period. The Orion spectrum consists of the lines of He I, N2, O 2 and may be H 1. The appearance of two additional components is probably due to splitting of the principal and diffuse enhanced spectrum
Impact of Distributed Generation Grid Code Requirements on Islanding Detection in LV Networks
Directory of Open Access Journals (Sweden)
Fabio Bignucolo
2017-01-01
Full Text Available The recent growing diffusion of dispersed generation in low voltage (LV distribution networks is entailing new rules to make local generators participate in network stability. Consequently, national and international grid codes, which define the connection rules for stability and safety of electrical power systems, have been updated requiring distributed generators and electrical storage systems to supply stabilizing contributions. In this scenario, specific attention to the uncontrolled islanding issue has to be addressed since currently required anti-islanding protection systems, based on relays locally measuring voltage and frequency, could no longer be suitable. In this paper, the effects on the interface protection performance of different LV generators’ stabilizing functions are analysed. The study takes into account existing requirements, such as the generators’ active power regulation (according to the measured frequency and reactive power regulation (depending on the local measured voltage. In addition, the paper focuses on other stabilizing features under discussion, derived from the medium voltage (MV distribution network grid codes or proposed in the literature, such as fast voltage support (FVS and inertia emulation. Stabilizing functions have been reproduced in the DIgSILENT PowerFactory 2016 software environment, making use of its native programming language. Later, they are tested both alone and together, aiming to obtain a comprehensive analysis on their impact on the anti-islanding protection effectiveness. Through dynamic simulations in several network scenarios the paper demonstrates the detrimental impact that such stabilizing regulations may have on loss-of-main protection effectiveness, leading to an increased risk of unintentional islanding.
Bárány, Imre; Vilcu, Costin
2016-01-01
This volume presents easy-to-understand yet surprising properties obtained using topological, geometric and graph theoretic tools in the areas covered by the Geometry Conference that took place in Mulhouse, France from September 7–11, 2014 in honour of Tudor Zamfirescu on the occasion of his 70th anniversary. The contributions address subjects in convexity and discrete geometry, in distance geometry or with geometrical flavor in combinatorics, graph theory or non-linear analysis. Written by top experts, these papers highlight the close connections between these fields, as well as ties to other domains of geometry and their reciprocal influence. They offer an overview on recent developments in geometry and its border with discrete mathematics, and provide answers to several open questions. The volume addresses a large audience in mathematics, including researchers and graduate students interested in geometry and geometrical problems.
Algorithms in Algebraic Geometry
Dickenstein, Alicia; Sommese, Andrew J
2008-01-01
In the last decade, there has been a burgeoning of activity in the design and implementation of algorithms for algebraic geometric computation. Some of these algorithms were originally designed for abstract algebraic geometry, but now are of interest for use in applications and some of these algorithms were originally designed for applications, but now are of interest for use in abstract algebraic geometry. The workshop on Algorithms in Algebraic Geometry that was held in the framework of the IMA Annual Program Year in Applications of Algebraic Geometry by the Institute for Mathematics and Its
O'Leary, Michael
2010-01-01
Guides readers through the development of geometry and basic proof writing using a historical approach to the topic. In an effort to fully appreciate the logic and structure of geometric proofs, Revolutions of Geometry places proofs into the context of geometry's history, helping readers to understand that proof writing is crucial to the job of a mathematician. Written for students and educators of mathematics alike, the book guides readers through the rich history and influential works, from ancient times to the present, behind the development of geometry. As a result, readers are successfull
Fundamental concepts of geometry
Meserve, Bruce E
1983-01-01
Demonstrates relationships between different types of geometry. Provides excellent overview of the foundations and historical evolution of geometrical concepts. Exercises (no solutions). Includes 98 illustrations.
Developments in special geometry
International Nuclear Information System (INIS)
Mohaupt, Thomas; Vaughan, Owen
2012-01-01
We review the special geometry of N = 2 supersymmetric vector and hypermultiplets with emphasis on recent developments and applications. A new formulation of the local c-map based on the Hesse potential and special real coordinates is presented. Other recent developments include the Euclidean version of special geometry, and generalizations of special geometry to non-supersymmetric theories. As applications we discuss the proof that the local r-map and c-map preserve geodesic completeness, and the construction of four- and five-dimensional static solutions through dimensional reduction over time. The shared features of the real, complex and quaternionic version of special geometry are stressed throughout.
International Nuclear Information System (INIS)
Buescher, R.
2005-01-01
Casimir interactions are interactions induced by quantum vacuum fluctuations and thermal fluctuations of the electromagnetic field. Using a path integral quantization for the gauge field, an effective Gaussian action will be derived which is the starting point to compute Casimir forces between macroscopic objects analytically and numerically. No assumptions about the independence of the material and shape dependent contributions to the interaction are made. We study the limit of flat surfaces in further detail and obtain a concise derivation of Lifshitz' theory of molecular forces. For the case of ideally conducting boundaries, the Gaussian action will be calculated explicitly. Both limiting cases are also discussed within the framework of a scalar field quantization approach, which is applicable for translationally invariant geometries. We develop a non-perturbative approach to calculate the Casimir interaction from the Gaussian action for periodically deformed and ideally conducting objects numerically. The obtained results reveal two different scaling regimes for the Casimir force as a function of the distance between the objects, their deformation wavelength and -amplitude. The results confirm that the interaction is non-additive, especially in the presence of strong geometric deformations. Furthermore, the numerical approach is extended to calculate lateral Casimir forces. The results are consistent with the results of the proximity-force approximation for large deformation wavelengths. A qualitatively different behaviour between the normal and lateral force is revealed. We also establish a relation between the boundary induced change of the of the density of states for the scalar Helmholtz equation and the Casimir interaction using the path integral method. For statically deformed boundaries, this relation can be expressed as a novel trace formula, which is formally similar to the so-called Krein-Friedel-Lloyd formula. While the latter formula describes the
Development of tools to manage the operational monitoring and pre-design of the NPP-LV cycle
International Nuclear Information System (INIS)
Perusquia, R.; Arredondo S, C.; Hernandez M, J. L.; Montes T, J. L.; Castillo M, A.; Ortiz S, J. J.
2015-09-01
This paper presents the development of tools to facilitate the management so much, the operational monitoring of boiling water reactors (BWR) of the nuclear power plant of Laguna Verde (NPP-LV) through independent codes, and how to carry out the static calculations corresponding to process of optimized pre-design of the reference cycle next to current cycle. The progress and preliminary results obtained with the program SACal, developed at Instituto Nacional de Investigaciones Nucleares (ININ), central tool to achieve provide a management platform of the operational monitoring and pre-design of NPP-LV cycle are also described. The reached preliminary advances directed to get an Analysis center and automated design of fuel assembly cells are also presented, which together with centers or similar modules related with the fuel reloads form the key part to meet the targets set for the realization of a Management Platform of Nuclear Fuel of the NPP-LV. (Author)
Czosek, Richard J; Cnota, James F; Knilans, Timothy K; Pratt, Jesse; Guerrier, Karine; Anderson, Jeffrey B
2014-09-01
In attempts to detect diseases that may place adolescents at risk for sudden death, some have advocated for population-based screening. Controversy exists over electrocardiography (ECG) screening due to the lack of specificity, cost, and detrimental effects of false positive or extraneous outcomes. Analyze the relationship between precordial lead voltage on ECG and left ventricle (LV) mass by echocardiogram in adolescent athletes. Retrospective cohort analysis of a prospectively obtained population of self-identified adolescent athletes during sports screening with ECG and echocardiogram. Correlation between ECG LV voltages (R wave in V6 [RV6] and S wave in lead V1 [SV1]) was compared to echocardiogram-based measurements of left ventricular mass. Potential effects on ECG voltages by body anthropometrics, including weight, body mass index (BMI), and body surface area were analyzed, and ECG voltages indexed to BMI were compared to LV mass indices to analyze for improved correlation. A total of 659 adolescents enrolled in this study (64% male). The mean age was 15.4 years (14-18). The correlations between LV mass and RV6, SV1, and RV6 + SV1 were all less than 0.20. The false positive rate for abnormal voltages was relatively high (5.5%) but improved if abnormal voltages in both RV6 and SV1 were mandated simultaneously (0%). Indexing ECG voltages to BMI significantly improved correlation to LV mass, though false positive findings were increased (12.9%). There is poor correlation between ECG precordial voltages and echocardiographic LV mass. This relationship is modified by BMI. This finding may contribute to the poor ECG screening characteristics. ©2014 Wiley Periodicals, Inc.
Geometry of multihadron production
Energy Technology Data Exchange (ETDEWEB)
Bjorken, J.D.
1994-10-01
This summary talk only reviews a small sample of topics featured at this symposium: Introduction; The Geometry and Geography of Phase space; Space-Time Geometry and HBT; Multiplicities, Intermittency, Correlations; Disoriented Chiral Condensate; Deep Inelastic Scattering at HERA; and Other Contributions.
1996-01-01
Designs and Finite Geometries brings together in one place important contributions and up-to-date research results in this important area of mathematics. Designs and Finite Geometries serves as an excellent reference, providing insight into some of the most important research issues in the field.
Geometry of multihadron production
International Nuclear Information System (INIS)
Bjorken, J.D.
1994-10-01
This summary talk only reviews a small sample of topics featured at this symposium: Introduction; The Geometry and Geography of Phase space; Space-Time Geometry and HBT; Multiplicities, Intermittency, Correlations; Disoriented Chiral Condensate; Deep Inelastic Scattering at HERA; and Other Contributions
Morris, Barbara H.
2004-01-01
This article describes a geometry project that used the beauty of stained-glass-window designs to teach middle school students about geometric figures and concepts. Three honors prealgebra teachers and a middle school mathematics gifted intervention specialist created a geometry project that covered the curriculum and also assessed students'…
Redetzke, Rebecca A.; Gerdes, A. Martin
2012-01-01
Thyroid hormones (THs) play a pivotal role in cardiac homeostasis. TH imbalances alter cardiac performance and ultimately cause cardiac dysfunction. Although short-term hyperthyroidism typically leads to heightened left ventricular (LV) contractility and improved hemodynamic parameters, chronic hyperthyroidism is associated with deleterious cardiac consequences including increased risk of arrhythmia, impaired cardiac reserve and exercise capacity, myocardial remodeling, and occasionally heart failure. To evaluate the long-term consequences of chronic hyperthyroidism on LV remodeling and function, we examined LV isolated myocyte function, chamber function, and whole tissue remodeling in a hamster model. Three-month-old F1b hamsters were randomized to control or 10 months TH treatment (0.1% grade I desiccated TH). LV chamber remodeling and function was assessed by echocardiography at 1, 2, 4, 6, 8, and 10 months of treatment. After 10 months, terminal cardiac function was assessed by echocardiography and LV hemodynamics. Hyperthyroid hamsters exhibited significant cardiac hypertrophy and deleterious cardiac remodeling characterized by myocyte lengthening, chamber dilatation, decreased relative wall thickness, increased wall stress, and increased LV interstitial fibrotic deposition. Importantly, hyperthyroid hamsters demonstrated significant LV systolic and diastolic dysfunction. Despite the aforementioned remodeling and global cardiac decline, individual isolated cardiac myocytes from chronically hyperthyroid hamsters had enhanced function when compared with myocytes from untreated age-matched controls. Thus, it appears that long-term hyperthyroidism may impair global LV function, at least in part by increasing interstitial ventricular fibrosis, in spite of normal or enhanced intrinsic cardiomyocyte function. PMID:23056390
Directory of Open Access Journals (Sweden)
Nathan Y Weltman
Full Text Available Thyroid hormones (THs play a pivotal role in cardiac homeostasis. TH imbalances alter cardiac performance and ultimately cause cardiac dysfunction. Although short-term hyperthyroidism typically leads to heightened left ventricular (LV contractility and improved hemodynamic parameters, chronic hyperthyroidism is associated with deleterious cardiac consequences including increased risk of arrhythmia, impaired cardiac reserve and exercise capacity, myocardial remodeling, and occasionally heart failure. To evaluate the long-term consequences of chronic hyperthyroidism on LV remodeling and function, we examined LV isolated myocyte function, chamber function, and whole tissue remodeling in a hamster model. Three-month-old F1b hamsters were randomized to control or 10 months TH treatment (0.1% grade I desiccated TH. LV chamber remodeling and function was assessed by echocardiography at 1, 2, 4, 6, 8, and 10 months of treatment. After 10 months, terminal cardiac function was assessed by echocardiography and LV hemodynamics. Hyperthyroid hamsters exhibited significant cardiac hypertrophy and deleterious cardiac remodeling characterized by myocyte lengthening, chamber dilatation, decreased relative wall thickness, increased wall stress, and increased LV interstitial fibrotic deposition. Importantly, hyperthyroid hamsters demonstrated significant LV systolic and diastolic dysfunction. Despite the aforementioned remodeling and global cardiac decline, individual isolated cardiac myocytes from chronically hyperthyroid hamsters had enhanced function when compared with myocytes from untreated age-matched controls. Thus, it appears that long-term hyperthyroidism may impair global LV function, at least in part by increasing interstitial ventricular fibrosis, in spite of normal or enhanced intrinsic cardiomyocyte function.
Energy Technology Data Exchange (ETDEWEB)
Grotz, Andreas
2011-10-07
In this thesis, a formulation of a Lorentzian quantum geometry based on the framework of causal fermion systems is proposed. After giving the general definition of causal fermion systems, we deduce space-time as a topological space with an underlying causal structure. Restricting attention to systems of spin dimension two, we derive the objects of our quantum geometry: the spin space, the tangent space endowed with a Lorentzian metric, connection and curvature. In order to get the correspondence to classical differential geometry, we construct examples of causal fermion systems by regularizing Dirac sea configurations in Minkowski space and on a globally hyperbolic Lorentzian manifold. When removing the regularization, the objects of our quantum geometry reduce to the common objects of spin geometry on Lorentzian manifolds, up to higher order curvature corrections.
Methods of information geometry
Amari, Shun-Ichi
2000-01-01
Information geometry provides the mathematical sciences with a new framework of analysis. It has emerged from the investigation of the natural differential geometric structure on manifolds of probability distributions, which consists of a Riemannian metric defined by the Fisher information and a one-parameter family of affine connections called the \\alpha-connections. The duality between the \\alpha-connection and the (-\\alpha)-connection together with the metric play an essential role in this geometry. This kind of duality, having emerged from manifolds of probability distributions, is ubiquitous, appearing in a variety of problems which might have no explicit relation to probability theory. Through the duality, it is possible to analyze various fundamental problems in a unified perspective. The first half of this book is devoted to a comprehensive introduction to the mathematical foundation of information geometry, including preliminaries from differential geometry, the geometry of manifolds or probability d...
International Nuclear Information System (INIS)
Grotz, Andreas
2011-01-01
In this thesis, a formulation of a Lorentzian quantum geometry based on the framework of causal fermion systems is proposed. After giving the general definition of causal fermion systems, we deduce space-time as a topological space with an underlying causal structure. Restricting attention to systems of spin dimension two, we derive the objects of our quantum geometry: the spin space, the tangent space endowed with a Lorentzian metric, connection and curvature. In order to get the correspondence to classical differential geometry, we construct examples of causal fermion systems by regularizing Dirac sea configurations in Minkowski space and on a globally hyperbolic Lorentzian manifold. When removing the regularization, the objects of our quantum geometry reduce to the common objects of spin geometry on Lorentzian manifolds, up to higher order curvature corrections.
Geometry on the space of geometries
International Nuclear Information System (INIS)
Christodoulakis, T.; Zanelli, J.
1988-06-01
We discuss the geometric structure of the configuration space of pure gravity. This is an infinite dimensional manifold, M, where each point represents one spatial geometry g ij (x). The metric on M is dictated by geometrodynamics, and from it, the Christoffel symbols and Riemann tensor can be found. A ''free geometry'' tracing a geodesic on the manifold describes the time evolution of space in the strong gravity limit. In a regularization previously introduced by the authors, it is found that M does not have the same dimensionality, D, everywhere, and that D is not a scalar, although it is covariantly constant. In this regularization, it is seen that the path integral measure can be absorbed in a renormalization of the cosmological constant. (author). 19 refs
Xie, Shijun; Li, Fuhua; Zhang, Xiaojun; Zhang, Jiquan; Xiang, Jianhai
2017-11-01
The peritrophic membrane plays an important role in the defense system of the arthropod gut. The digestive tract is considered one of the major tissues targeted by white spot syndrome virus (WSSV) in shrimp. In this study, the nucleotide sequence encoding peritrophin-like protein of Litopenaeus vannamei (LvPT) was amplified from a yeast two-hybrid library of L. vannamei. The epitope peptide of LvPT was predicted with the GenScript OptimumAntigen™ design tool. An anti-LvPT polyclonal antibody was produced and shown to specifically bind a band at 27 kDa, identified as LvPT. The LvPT protein was expressed and its concentration determined. LvPT dsRNA (4 μg per shrimp) was used to inhibit LvPT expression in shrimp, and a WSSV challenge experiment was then performed with reverse gavage. The pleopods, stomachs, and guts were collected from the shrimp at 0, 24, 48, and 72 h post-infection (hpi). Viral load quantification showed that the levels of WSSV were significantly lower in the pleopods, stomachs, and guts of shrimp after LvPT dsRNA interference than in those of the controls at 48 and 72 hpi. Our results imply that LvPT plays an important role during WSSV infection of the digestive tract.
Munro, Hannah J; Berghuis, Lesley; Lang, Andrew S; Rogers, Laura; Whitney, Hugh
2014-04-01
Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) are retroviruses found within domestic and wild cat populations. These viruses cause severe illnesses that eventually lead to death. Housing cats communally for long periods of time makes shelters at high risk for virus transmission among cats. We tested 548 cats from 5 different sites across the island of Newfoundland for FIV and FeLV. The overall seroprevalence was 2.2% and 6.2% for FIV and FeLV, respectively. Two sites had significantly higher seroprevalence of FeLV infection than the other 3 sites. Analysis of sequences from the FeLV env gene (envelope gene) from 6 positive cats showed that 4 fell within the FeLV subtype-A, while 2 sequences were most closely related to FeLV subtype-B and endogenous feline leukemia virus (en FeLV). Varying seroprevalence and the variation in sequences at different sites demonstrate that some shelters are at greater risk of FeLV infections and recombination can occur at sites of high seroprevalence.
Bolin, Lisa L; Ahmad, Shamim; Levy, Laura S
2011-10-15
Feline leukemia virus (FeLV) is a natural retrovirus of domestic cats associated with degenerative, proliferative and malignant diseases. Studies of FeLV infection in a cohort of naturally infected cats were undertaken to examine FeLV variation, the selective pressures operative in FeLV infection that lead to predominance of natural variants, and the consequences for infection and disease progression. A unique variant, designated FeLV-945, was identified as the predominant isolate in the cohort and was associated with non-T-cell diseases including multicentric lymphoma. FeLV-945 was assigned to the FeLV-A subgroup based on sequence analysis and receptor utilization, but was shown to differ in sequence from a prototype member of FeLV-A, designated FeLV-A/61E, in the long terminal repeat (LTR) and the surface glycoprotein gene (SU). A unique sequence motif in the FeLV-945 LTR was shown to function as a transcriptional enhancer and to confer a replicative advantage. The FeLV-945 SU protein was observed to differ in sequence as compared to FeLV-A/61E within functional domains known to determine receptor selection and binding. Experimental infection of newborn cats was performed using wild type FeLV-A/61E or recombinant FeLV-A/61E in which the LTR (61E/945L) or LTR and SU (61E/945SL) were exchanged for that of FeLV-945. Infection with either FeLV-A/61E or 61E/945L resulted in T-cell lymphoma of the thymus, although 61E/945L caused disease significantly more rapidly. In contrast, infection with 61E/945SL resulted in the rapid induction of a multicentric lymphoma of B-cell origin, thus recapitulating the outcome of natural infection and implicating FeLV-945 SU as a determinant of disease outcome. Recombinant FeLV-B was detected infrequently and at low levels in multicentric lymphomas, and was thereby not implicated in disease induction. Preliminary studies of receptor interaction indicated that virus particles bearing FeLV-945 SU bind to the FeLV-A receptor more
Modelling wetland-groundwater interactions in the boreal Kälväsvaara esker, Northern Finland
Jaros, Anna; Rossi, Pekka; Ronkanen, Anna-Kaisa; Kløve, Bjørn
2016-04-01
Many types of boreal peatland ecosystems such as alkaline fens, aapa mires and Fennoscandia spring fens rely on the presence of groundwater. In these ecosystems groundwater creates unique conditions for flora and fauna by providing water, nutrients and constant water temperature enriching local biodiversity. The groundwater-peatland interactions and their dynamics are not, however, in many cases fully understood and their measurement and quantification is difficult due to highly heterogeneous structure of peatlands and large spatial extend of these ecosystems. Understanding of these interactions and their changes due to anthropogenic impact on groundwater resources would benefit the protection of the groundwater dependent peatlands. The groundwater-peatland interactions were investigated using the fully-integrated physically-based groundwater-surface water code HydroGeoSphere in a case study of the Kälväsvaara esker aquifer, Northern Finland. The Kälväsvaara is a geologically complex esker and it is surrounded by vast aapa mire system including alkaline and springs fens. In addition, numerous small springs occur in the discharge zone of the esker. In order to quantify groundwater-peatland interactions a simple steady-state model was built and results were evaluated using expected trends and field measurements. The employed model reproduced relatively well spatially distributed hydrological variables such as soil water content, water depths and groundwater-surface water exchange fluxes within the wetland and esker areas. The wetlands emerged in simulations as a result of geological and topographical conditions. They could be identified by high saturation levels at ground surface and by presence of shallow ponded water over some areas. The model outputs exhibited also strong surface water-groundwater interactions in some parts of the aapa system. These areas were noted to be regions of substantial diffusive groundwater discharge by the earlier studies. In
Tattiyapong, Puntanat; Dachavichitlead, Worawan; Surachetpong, Win
2017-08-01
Since 2015, a novel orthomyxo-like virus, tilapia lake virus (TiLV) has been associated with outbreaks of disease and massive mortality of cultured Nile and red tilapia (Oreochromis niloticus and Oreochromis spp., respectively) in Thailand. In this study, TiLV was isolated from field samples and propagated in the permissive E-11 cell line, with cytopathic effect (CPE) development within 3-5days post-inoculation. Electron micrographs of infected E-11 cells and fish tissues confirmed the rounded, enveloped virions of 60 to 80nm with characteristics very similar to those of Orthomyxoviridae. In vivo challenge studies showed that high mortality in Nile (86%) and red tilapia (66%) occurred within 4-12days post-infection. The virus was re-isolated from challenged fish tissues in the permissive cell line, and PCR analysis confirmed TiLV as a causative pathogen. The distinct histopathology of challenged fish included massive degeneration and inflammatory cell infiltration in the liver and brain as well as the presence of eosinophilic intracytoplasmic inclusions in hepatocytes and splenic cells. Our results fulfilled Koch's postulates and confirmed that TiLV is an etiologic agent of mass mortality of tilapia in Thailand. The emergence of this virus in many countries has helped increase awareness that it is a potential threat to tilapia aquacultured in Thailand, Asia, and worldwide. Copyright © 2017 Elsevier B.V. All rights reserved.
Complex and symplectic geometry
Medori, Costantino; Tomassini, Adriano
2017-01-01
This book arises from the INdAM Meeting "Complex and Symplectic Geometry", which was held in Cortona in June 2016. Several leading specialists, including young researchers, in the field of complex and symplectic geometry, present the state of the art of their research on topics such as the cohomology of complex manifolds; analytic techniques in Kähler and non-Kähler geometry; almost-complex and symplectic structures; special structures on complex manifolds; and deformations of complex objects. The work is intended for researchers in these areas.
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
Roe, John
2003-01-01
Coarse geometry is the study of spaces (particularly metric spaces) from a 'large scale' point of view, so that two spaces that look the same from a great distance are actually equivalent. This point of view is effective because it is often true that the relevant geometric properties of metric spaces are determined by their coarse geometry. Two examples of important uses of coarse geometry are Gromov's beautiful notion of a hyperbolic group and Mostow's proof of his famous rigidity theorem. The first few chapters of the book provide a general perspective on coarse structures. Even when only metric coarse structures are in view, the abstract framework brings the same simplification as does the passage from epsilons and deltas to open sets when speaking of continuity. The middle section reviews notions of negative curvature and rigidity. Modern interest in large scale geometry derives in large part from Mostow's rigidity theorem and from Gromov's subsequent 'large scale' rendition of the crucial properties of n...
Lectures on Symplectic Geometry
Silva, Ana Cannas
2001-01-01
The goal of these notes is to provide a fast introduction to symplectic geometry for graduate students with some knowledge of differential geometry, de Rham theory and classical Lie groups. This text addresses symplectomorphisms, local forms, contact manifolds, compatible almost complex structures, Kaehler manifolds, hamiltonian mechanics, moment maps, symplectic reduction and symplectic toric manifolds. It contains guided problems, called homework, designed to complement the exposition or extend the reader's understanding. There are by now excellent references on symplectic geometry, a subset of which is in the bibliography of this book. However, the most efficient introduction to a subject is often a short elementary treatment, and these notes attempt to serve that purpose. This text provides a taste of areas of current research and will prepare the reader to explore recent papers and extensive books on symplectic geometry where the pace is much faster. For this reprint numerous corrections and cl...
Kollár, János
1997-01-01
This volume contains the lectures presented at the third Regional Geometry Institute at Park City in 1993. The lectures provide an introduction to the subject, complex algebraic geometry, making the book suitable as a text for second- and third-year graduate students. The book deals with topics in algebraic geometry where one can reach the level of current research while starting with the basics. Topics covered include the theory of surfaces from the viewpoint of recent higher-dimensional developments, providing an excellent introduction to more advanced topics such as the minimal model program. Also included is an introduction to Hodge theory and intersection homology based on the simple topological ideas of Lefschetz and an overview of the recent interactions between algebraic geometry and theoretical physics, which involve mirror symmetry and string theory.
DEFF Research Database (Denmark)
Kokkendorff, Simon Lyngby
2002-01-01
The subject of this Ph.D.-thesis is somewhere in between continuous and discrete geometry. Chapter 2 treats the geometry of finite point sets in semi-Riemannian hyperquadrics,using a matrix whose entries are a trigonometric function of relative distances in a given point set. The distance...... to the geometry of a simplex in a semi-Riemannian hyperquadric. In chapter 3 we study which finite metric spaces that are realizable in a hyperbolic space in the limit where curvature goes to -∞. We show that such spaces are the so called leaf spaces, the set of degree 1 vertices of weighted trees. We also...... establish results on the limiting geometry of such an isometrically realized leaf space simplex in hyperbolic space, when curvature goes to -∞. Chapter 4 discusses negative type of metric spaces. We give a measure theoretic treatment of this concept and related invariants. The theory developed...
Busemann, Herbert
2005-01-01
A comprehensive approach to qualitative problems in intrinsic differential geometry, this text examines Desarguesian spaces, perpendiculars and parallels, covering spaces, the influence of the sign of the curvature on geodesics, more. 1955 edition. Includes 66 figures.
Tabachnikov, Serge
2005-01-01
Mathematical billiards describe the motion of a mass point in a domain with elastic reflections off the boundary or, equivalently, the behavior of rays of light in a domain with ideally reflecting boundary. From the point of view of differential geometry, the billiard flow is the geodesic flow on a manifold with boundary. This book is devoted to billiards in their relation with differential geometry, classical mechanics, and geometrical optics. The topics covered include variational principles of billiard motion, symplectic geometry of rays of light and integral geometry, existence and nonexistence of caustics, optical properties of conics and quadrics and completely integrable billiards, periodic billiard trajectories, polygonal billiards, mechanisms of chaos in billiard dynamics, and the lesser-known subject of dual (or outer) billiards. The book is based on an advanced undergraduate topics course (but contains more material than can be realistically taught in one semester). Although the minimum prerequisit...
Introduction to tropical geometry
Maclagan, Diane
2015-01-01
Tropical geometry is a combinatorial shadow of algebraic geometry, offering new polyhedral tools to compute invariants of algebraic varieties. It is based on tropical algebra, where the sum of two numbers is their minimum and the product is their sum. This turns polynomials into piecewise-linear functions, and their zero sets into polyhedral complexes. These tropical varieties retain a surprising amount of information about their classical counterparts. Tropical geometry is a young subject that has undergone a rapid development since the beginning of the 21st century. While establishing itself as an area in its own right, deep connections have been made to many branches of pure and applied mathematics. This book offers a self-contained introduction to tropical geometry, suitable as a course text for beginning graduate students. Proofs are provided for the main results, such as the Fundamental Theorem and the Structure Theorem. Numerous examples and explicit computations illustrate the main concepts. Each of t...
Rudiments of algebraic geometry
Jenner, WE
2017-01-01
Aimed at advanced undergraduate students of mathematics, this concise text covers the basics of algebraic geometry. Topics include affine spaces, projective spaces, rational curves, algebraic sets with group structure, more. 1963 edition.
Implosions and hypertoric geometry
DEFF Research Database (Denmark)
Dancer, A.; Kirwan, F.; Swann, A.
2013-01-01
The geometry of the universal hyperkahler implosion for SU (n) is explored. In particular, we show that the universal hyperkahler implosion naturally contains a hypertoric variety described in terms of quivers. Furthermore, we discuss a gauge theoretic approach to hyperkahler implosion.......The geometry of the universal hyperkahler implosion for SU (n) is explored. In particular, we show that the universal hyperkahler implosion naturally contains a hypertoric variety described in terms of quivers. Furthermore, we discuss a gauge theoretic approach to hyperkahler implosion....
Intermediate algebra & analytic geometry
Gondin, William R
1967-01-01
Intermediate Algebra & Analytic Geometry Made Simple focuses on the principles, processes, calculations, and methodologies involved in intermediate algebra and analytic geometry. The publication first offers information on linear equations in two unknowns and variables, functions, and graphs. Discussions focus on graphic interpretations, explicit and implicit functions, first quadrant graphs, variables and functions, determinate and indeterminate systems, independent and dependent equations, and defective and redundant systems. The text then examines quadratic equations in one variable, system
Ceresole, Anna; Gnecchi, Alessandra; Marrani, Alessio
2013-01-01
We analyze some properties of the four dimensional supergravity theories which originate from five dimensions upon reduction. They generalize to N>2 extended supersymmetries the d-geometries with cubic prepotentials, familiar from N=2 special K\\"ahler geometry. We emphasize the role of a suitable parametrization of the scalar fields and the corresponding triangular symplectic basis. We also consider applications to the first order flow equations for non-BPS extremal black holes.
International Nuclear Information System (INIS)
Osborne, I; Brownson, E; Eulisse, G; Jones, C D; Sexton-Kennedy, E; Lange, D J
2014-01-01
CMS faces real challenges with upgrade of the CMS detector through 2020 and beyond. One of the challenges, from the software point of view, is managing upgrade simulations with the same software release as the 2013 scenario. We present the CMS geometry description software model, its integration with the CMS event setup and core software. The CMS geometry configuration and selection is implemented in Python. The tools collect the Python configuration fragments into a script used in CMS workflow. This flexible and automated geometry configuration allows choosing either transient or persistent version of the same scenario and specific version of the same scenario. We describe how the geometries are integrated and validated, and how we define and handle different geometry scenarios in simulation and reconstruction. We discuss how to transparently manage multiple incompatible geometries in the same software release. Several examples are shown based on current implementation assuring consistent choice of scenario conditions. The consequences and implications for multiple/different code algorithms are discussed.
Software Geometry in Simulations
Alion, Tyler; Viren, Brett; Junk, Tom
2015-04-01
The Long Baseline Neutrino Experiment (LBNE) involves many detectors. The experiment's near detector (ND) facility, may ultimately involve several detectors. The far detector (FD) will be significantly larger than any other Liquid Argon (LAr) detector yet constructed; many prototype detectors are being constructed and studied to motivate a plethora of proposed FD designs. Whether it be a constructed prototype or a proposed ND/FD design, every design must be simulated and analyzed. This presents a considerable challenge to LBNE software experts; each detector geometry must be described to the simulation software in an efficient way which allows for multiple authors to easily collaborate. Furthermore, different geometry versions must be tracked throughout their use. We present a framework called General Geometry Description (GGD), written and developed by LBNE software collaborators for managing software to generate geometries. Though GGD is flexible enough to be used by any experiment working with detectors, we present it's first use in generating Geometry Description Markup Language (GDML) files to interface with LArSoft, a framework of detector simulations, event reconstruction, and data analyses written for all LAr technology users at Fermilab. Brett is the other of the framework discussed here, the General Geometry Description (GGD).
Introduction to combinatorial geometry
International Nuclear Information System (INIS)
Gabriel, T.A.; Emmett, M.B.
1985-01-01
The combinatorial geometry package as used in many three-dimensional multimedia Monte Carlo radiation transport codes, such as HETC, MORSE, and EGS, is becoming the preferred way to describe simple and complicated systems. Just about any system can be modeled using the package with relatively few input statements. This can be contrasted against the older style geometry packages in which the required input statements could be large even for relatively simple systems. However, with advancements come some difficulties. The users of combinatorial geometry must be able to visualize more, and, in some instances, all of the system at a time. Errors can be introduced into the modeling which, though slight, and at times hard to detect, can have devastating effects on the calculated results. As with all modeling packages, the best way to learn the combinatorial geometry is to use it, first on a simple system then on more complicated systems. The basic technique for the description of the geometry consists of defining the location and shape of the various zones in terms of the intersections and unions of geometric bodies. The geometric bodies which are generally included in most combinatorial geometry packages are: (1) box, (2) right parallelepiped, (3) sphere, (4) right circular cylinder, (5) right elliptic cylinder, (6) ellipsoid, (7) truncated right cone, (8) right angle wedge, and (9) arbitrary polyhedron. The data necessary to describe each of these bodies are given. As can be easily noted, there are some subsets included for simplicity
The odd side of torsion geometry
DEFF Research Database (Denmark)
Conti, Diego; Madsen, Thomas Bruun
2014-01-01
We introduce and study a notion of `Sasaki with torsion structure' (ST) as an odd-dimensional analogue of Kähler with torsion geometry (KT). These are normal almost contact metric manifolds that admit a unique compatible connection with 3-form torsion. Any odd-dimensional compact Lie group is sho...
Global aspects of complex geometry
Catanese, Fabrizio; Huckleberry, Alan T
2006-01-01
Present an overview of developments in Complex Geometry. This book covers topics that range from curve and surface theory through special varieties in higher dimensions, moduli theory, Kahler geometry, and group actions to Hodge theory and characteristic p-geometry.
International Nuclear Information System (INIS)
Janowski, M.; Merregaert, J.; Nuyten, J.M.; Maisin, J.R.
1984-01-01
An infectious clone of the linear, unintegrated RadLV provirus was obtained by insertion in the plasmid pBR322. Its restriction map was indistinguishable from that of the majority of the multiple proviral copies, which are found apparently at random sites in the DNA of RadLV-induced rat thymic lymphomas [fr
Chuang, Michael L.; Gona, Philimon; Hautvast, Gilion L T F; Salton, Carol J.; Blease, Susan J.; Yeon, Susan B.; Breeuwer, Marcel; O'Donnell, Christopher J.; Manning, Warren J.
2012-01-01
Objectives: The goal of this study was to assess the relationship of left ventricular (LV) trabeculae and papillary muscles (TPM) with clinical characteristics in a community-based, free-living adult cohort and to determine the effect of TPM on quantitative measures of LV volume, mass, and ejection
Montoya, Nelson; Reyes, Eduardo
2002-01-01
Acumulación/eliminación de oxitetraciclina en el camarón blanco, LV y su residualidad en dietas artificiales Acumulación/eliminación de oxitetraciclina en el camarón blanco, LV y su residualidad en dietas artificiales
Wang, Haoyu; Sun, Yingxian; Li, Zhao; Guo, Xiaofan; Chen, Shuang; Ye, Ning; Tian, Yichen; Zhang, Lijun
2018-04-10
Despite current interest in the unfavorable impact of cardiometabolic index (CMI) and lipid accumulation product (LAP) on diabetes and cardiovascular risk, information regarding the relation of CMI and LAP to left ventricular (LV) geometry has not been specifically addressed. We aimed to examine the hypothesis: (1) CMI and LAP represent an independent determinant of LV remodeling in general population of rural China; (2) there are gender differences in obesity-related alterations in terms of LV morphology. The sample for this cross-sectional analysis included 11,258 participants (mean age 53.9 years; 54.0% females) who underwent assessment of basic metabolic and anthropometric parameters in rural areas of northeast China. Comprehensive echocardiography-defined LV geometric pattern was determined according to left ventricular mass index and relative wall thickness. The prevalence rate of eccentric and concentric LV hypertrophy (LVH) presented a proportional increase with elevated quartiles of CMI and LAP in a dose-response manner (all P factor of 3.552 and 1.768 in females and males, respectively. In contrast to females, where LAP fourth quartile and concentric LVH were positively associated (OR:2.544, 95%CI:1.537-4.209), higher LAP did not correlate with concentric LVH in males (OR:1.234, 95%CI:0.824-1.849). CMI and LAP give rise to a new paradigm of accounting for gender difference in obesity-related abnormal LV geometry, an effect that was substantially greater in females. These two indices, acting in concert, may also be advantageous prognostically for refining cardiovascular risk stratification in individuals with LV remodeling.
International Nuclear Information System (INIS)
Ali, A.Z.
2007-01-01
Full text: Aim: To compare the perfusion and LV function parameters as quantified by 4D-MSPECT and ECT in the same patient group and a qualitative comparison of the reconstructed slices by two different experts. Materials and methods: Thirty-one consecutive patients underwent gated myocardial perfusion SPECT using a two-day protocol. The gated and ungated data were reconstructed by back projection method. Quantitative analysis was performed on the same set of reconstructed slices by 4D-MSPECT and Emory Cardiac Tool Box. The reconstructed slices were read qualitatively by two different experts on their respective systems. Polar map and functional analysis was performed in both softwares and the results were compared. Results: The concordance between the two experts qualitatively was seen in 78/93(84%) coronary territories. The polar map defects were comparable in LAD (r-value of 0.87) and LCX (r-value of 0.76) territories whereas RCA defects (r-value of 0.04) were not at all correlating. The defect severity showed concordance in 68/93 (73%) coronary territories. There was concordance between 4DMSPECT and the qualitative interpretation in 84/93 (90%) coronary territories whereas ECT showed concordance in only 70/93(75%) coronary territories. The overall sensitivity is marginally higher for ECT (100% vs. 96%) but the overall specificity is much higher with 4 DMSPECT (88% vs. 65%). ESV showed good correlation(r=0.94) of the two softwares with no significant difference in means. EDV and LVEF although had good correlation(r = 0.96 and 0.89) showed high difference in means (p<0.01). Conclusion: Between 4D-MSPECT and ECT, 4D-MSPECT is marginally superior to ECT with reference to qualitative interpretation in view of better specificity. The LVEF values between the two softwares should also not be used interchangeably. (author)
Directory of Open Access Journals (Sweden)
Daniella Poffo
Full Text Available ABSTRACT: This search aimed to investigate FIV and FeLV infections in domestic cats, analysing the epidemiological profile of the disease as well as additional infection with Leishmania sp. We evaluated 88 domestic cats for the presence of FIV, FeLV and Leishmania sp. infection. Eleven (12.5% cats were positive for FIV infection, four (4.5% were positive for FeLV, and two were co-infected. However, none was infected with Leishmania sp. The prevalence for FIV infection was higher than FeLV, and those observed in other regions, but no factor was associated with the infection by FIV and FeLV in this study.
Sources of hyperbolic geometry
Stillwell, John
1996-01-01
This book presents, for the first time in English, the papers of Beltrami, Klein, and Poincaré that brought hyperbolic geometry into the mainstream of mathematics. A recognition of Beltrami comparable to that given the pioneering works of Bolyai and Lobachevsky seems long overdue-not only because Beltrami rescued hyperbolic geometry from oblivion by proving it to be logically consistent, but because he gave it a concrete meaning (a model) that made hyperbolic geometry part of ordinary mathematics. The models subsequently discovered by Klein and Poincaré brought hyperbolic geometry even further down to earth and paved the way for the current explosion of activity in low-dimensional geometry and topology. By placing the works of these three mathematicians side by side and providing commentaries, this book gives the student, historian, or professional geometer a bird's-eye view of one of the great episodes in mathematics. The unified setting and historical context reveal the insights of Beltrami, Klein, and Po...
International Nuclear Information System (INIS)
Jonsson, Rickard; Westman, Hans
2006-01-01
We show that by employing the standard projected curvature as a measure of spatial curvature, we can make a certain generalization of optical geometry (Abramowicz M A and Lasota J-P 1997 Class. Quantum Grav. A 14 23-30). This generalization applies to any spacetime that admits a hypersurface orthogonal shearfree congruence of worldlines. This is a somewhat larger class of spacetimes than the conformally static spacetimes assumed in standard optical geometry. In the generalized optical geometry, which in the generic case is time dependent, photons move with unit speed along spatial geodesics and the sideways force experienced by a particle following a spatially straight line is independent of the velocity. Also gyroscopes moving along spatial geodesics do not precess (relative to the forward direction). Gyroscopes that follow a curved spatial trajectory precess according to a very simple law of three-rotation. We also present an inertial force formalism in coordinate representation for this generalization. Furthermore, we show that by employing a new sense of spatial curvature (Jonsson R 2006 Class. Quantum Grav. 23 1)) closely connected to Fermat's principle, we can make a more extensive generalization of optical geometry that applies to arbitrary spacetimes. In general this optical geometry will be time dependent, but still geodesic photons move with unit speed and follow lines that are spatially straight in the new sense. Also, the sideways experienced (comoving) force on a test particle following a line that is straight in the new sense will be independent of the velocity
Energy Technology Data Exchange (ETDEWEB)
Flaherty, Julia E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Glissmeyer, John A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
2015-03-18
Tests were performed to evaluate a sample conditioning unit for stack monitoring at Hanford Tank Waste Treatment and Immobilization Plant (WTP) exhaust stacks with elevated air temperatures. The LV-S2, LV-S3, HV-S3A and HV-S3B exhaust stacks are expected to have elevated air temperature and dew point. At these emission points, exhaust temperatures are too high to deliver the air sample directly to the required stack monitoring equipment. As a result, a sample conditioning system is considered to cool and dry the air prior to its delivery to the stack monitoring system. The method proposed for the sample conditioning is a dilution system that will introduce cooler, dry air to the air sample stream. This method of sample conditioning is meant to reduce the sample temperature while avoiding condensation of moisture in the sample stream. An additional constraint is that the ANSI/HPS N13.1-1999 standard states that at least 50% of the 10 μm aerodynamic diameter (AD) particles present in the stack free stream must be delivered to the sample collector. In other words, depositional loss of particles should be limited to 50% in the sampling, transport, and conditioning systems. Based on estimates of particle penetration through the LV-S3 sampling system, the diluter should perform with about 80% penetration or better to ensure that the total sampling system passes the 50% or greater penetration criterion.
Computational synthetic geometry
Bokowski, Jürgen
1989-01-01
Computational synthetic geometry deals with methods for realizing abstract geometric objects in concrete vector spaces. This research monograph considers a large class of problems from convexity and discrete geometry including constructing convex polytopes from simplicial complexes, vector geometries from incidence structures and hyperplane arrangements from oriented matroids. It turns out that algorithms for these constructions exist if and only if arbitrary polynomial equations are decidable with respect to the underlying field. Besides such complexity theorems a variety of symbolic algorithms are discussed, and the methods are applied to obtain new mathematical results on convex polytopes, projective configurations and the combinatorics of Grassmann varieties. Finally algebraic varieties characterizing matroids and oriented matroids are introduced providing a new basis for applying computer algebra methods in this field. The necessary background knowledge is reviewed briefly. The text is accessible to stud...
Discrete and computational geometry
Devadoss, Satyan L
2011-01-01
Discrete geometry is a relatively new development in pure mathematics, while computational geometry is an emerging area in applications-driven computer science. Their intermingling has yielded exciting advances in recent years, yet what has been lacking until now is an undergraduate textbook that bridges the gap between the two. Discrete and Computational Geometry offers a comprehensive yet accessible introduction to this cutting-edge frontier of mathematics and computer science. This book covers traditional topics such as convex hulls, triangulations, and Voronoi diagrams, as well as more recent subjects like pseudotriangulations, curve reconstruction, and locked chains. It also touches on more advanced material, including Dehn invariants, associahedra, quasigeodesics, Morse theory, and the recent resolution of the Poincaré conjecture. Connections to real-world applications are made throughout, and algorithms are presented independently of any programming language. This richly illustrated textbook also fe...
Ochiai, T.; Nacher, J. C.
2011-09-01
Recently, the application of geometry and conformal mappings to artificial materials (metamaterials) has attracted the attention in various research communities. These materials, characterized by a unique man-made structure, have unusual optical properties, which materials found in nature do not exhibit. By applying the geometry and conformal mappings theory to metamaterial science, it may be possible to realize so-called "Harry Potter cloaking device". Although such a device is still in the science fiction realm, several works have shown that by using such metamaterials it may be possible to control the direction of the electromagnetic field at will. We could then make an object hidden inside of a cloaking device. Here, we will explain how to design invisibility device using differential geometry and conformal mappings.
2002-01-01
Discrete geometry investigates combinatorial properties of configurations of geometric objects. To a working mathematician or computer scientist, it offers sophisticated results and techniques of great diversity and it is a foundation for fields such as computational geometry or combinatorial optimization. This book is primarily a textbook introduction to various areas of discrete geometry. In each area, it explains several key results and methods, in an accessible and concrete manner. It also contains more advanced material in separate sections and thus it can serve as a collection of surveys in several narrower subfields. The main topics include: basics on convex sets, convex polytopes, and hyperplane arrangements; combinatorial complexity of geometric configurations; intersection patterns and transversals of convex sets; geometric Ramsey-type results; polyhedral combinatorics and high-dimensional convexity; and lastly, embeddings of finite metric spaces into normed spaces. Jiri Matousek is Professor of Com...
Zheng, Fangyang
2002-01-01
The theory of complex manifolds overlaps with several branches of mathematics, including differential geometry, algebraic geometry, several complex variables, global analysis, topology, algebraic number theory, and mathematical physics. Complex manifolds provide a rich class of geometric objects, for example the (common) zero locus of any generic set of complex polynomials is always a complex manifold. Yet complex manifolds behave differently than generic smooth manifolds; they are more coherent and fragile. The rich yet restrictive character of complex manifolds makes them a special and interesting object of study. This book is a self-contained graduate textbook that discusses the differential geometric aspects of complex manifolds. The first part contains standard materials from general topology, differentiable manifolds, and basic Riemannian geometry. The second part discusses complex manifolds and analytic varieties, sheaves and holomorphic vector bundles, and gives a brief account of the surface classifi...
Information-Quality based LV-Grid-Monitoring Framework and its Application to Power-Quality Control
DEFF Research Database (Denmark)
Findrik, Mislav; Kristensen, Thomas le Fevre; Hinterhofer, Thomas
2015-01-01
The integration of unpredictable renewable energy sources into the low voltage (LV) power grid results in new challenges when it comes to ensuring power quality in the electrical grid. Addressing this problem requires control of not only the secondary substation but also control of flexible assets...... inside the LV grid. In this paper we investigate how the flexibility information of such assets can be accessed by the controller using heterogeneous off-the-shelf communication networks. To achieve this we develop an adaptive monitoring framework, through which the controller can subscribe to the assets......' flexibility information through an API. We define an information quality metric making the monitoring framework able to adapt information access strategies to ensure the information is made available to the controller with the highest possible information quality. To evaluate the monitoring framework...
Yale, Paul B
2012-01-01
This book is an introduction to the geometry of Euclidean, affine, and projective spaces with special emphasis on the important groups of symmetries of these spaces. The two major objectives of the text are to introduce the main ideas of affine and projective spaces and to develop facility in handling transformations and groups of transformations. Since there are many good texts on affine and projective planes, the author has concentrated on the n-dimensional cases.Designed to be used in advanced undergraduate mathematics or physics courses, the book focuses on ""practical geometry,"" emphasi
International Nuclear Information System (INIS)
Gervais, J.L.
1993-01-01
By analyzing the extrinsic geometry of two dimensional surfaces chirally embedded in C P n (the C P n W-surface), we give exact treatments in various aspects of the classical W-geometry in the conformal gauge: First, the basis of tangent and normal vectors are defined at regular points of the surface, such that their infinitesimal displacements are given by connections which coincide with the vector potentials of the (conformal) A n -Toda Lax pair. Since the latter is known to be intrinsically related with the W symmetries, this gives the geometrical meaning of the A n W-Algebra. Second, W-surfaces are put in one-to-one correspondence with solutions of the conformally-reduced WZNW model, which is such that the Toda fields give the Cartan part in the Gauss decomposition of its solutions. Third, the additional variables of the Toda hierarchy are used as coordinates of C P n . This allows us to show that W-transformations may be extended as particular diffeomorphisms of this target-space. Higher-dimensional generalizations of the WZNW equations are derived and related with the Zakharov-Shabat equations of the Toda hierarchy. Fourth, singular points are studied from a global viewpoint, using our earlier observation that W-surfaces may be regarded as instantons. The global indices of the W-geometry, which are written in terms of the Toda fields, are shown to be the instanton numbers for associated mappings of W-surfaces into the Grassmannians. The relation with the singularities of W-surface is derived by combining the Toda equations with the Gauss-Bonnet theorem. (orig.)
Geometry of isotropic convex bodies
Brazitikos, Silouanos; Valettas, Petros; Vritsiou, Beatrice-Helen
2014-01-01
The study of high-dimensional convex bodies from a geometric and analytic point of view, with an emphasis on the dependence of various parameters on the dimension stands at the intersection of classical convex geometry and the local theory of Banach spaces. It is also closely linked to many other fields, such as probability theory, partial differential equations, Riemannian geometry, harmonic analysis and combinatorics. It is now understood that the convexity assumption forces most of the volume of a high-dimensional convex body to be concentrated in some canonical way and the main question is whether, under some natural normalization, the answer to many fundamental questions should be independent of the dimension. The aim of this book is to introduce a number of well-known questions regarding the distribution of volume in high-dimensional convex bodies, which are exactly of this nature: among them are the slicing problem, the thin shell conjecture and the Kannan-Lov�sz-Simonovits conjecture. This book prov...
Carpenter, Donald A.
2008-01-01
Confusion exists among database textbooks as to the goal of normalization as well as to which normal form a designer should aspire. This article discusses such discrepancies with the intention of simplifying normalization for both teacher and student. This author's industry and classroom experiences indicate such simplification yields quicker…
Towards relativistic quantum geometry
Energy Technology Data Exchange (ETDEWEB)
Ridao, Luis Santiago [Instituto de Investigaciones Físicas de Mar del Plata (IFIMAR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata (Argentina); Bellini, Mauricio, E-mail: mbellini@mdp.edu.ar [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350, C.P. 7600, Mar del Plata (Argentina); Instituto de Investigaciones Físicas de Mar del Plata (IFIMAR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata (Argentina)
2015-12-17
We obtain a gauge-invariant relativistic quantum geometry by using a Weylian-like manifold with a geometric scalar field which provides a gauge-invariant relativistic quantum theory in which the algebra of the Weylian-like field depends on observers. An example for a Reissner–Nordström black-hole is studied.
Multiplicity in difference geometry
Tomasic, Ivan
2011-01-01
We prove a first principle of preservation of multiplicity in difference geometry, paving the way for the development of a more general intersection theory. In particular, the fibres of a \\sigma-finite morphism between difference curves are all of the same size, when counted with correct multiplicities.
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.
International Nuclear Information System (INIS)
Konopleva, N.P.
2009-01-01
The basic ideas of description methods of physical fields and elementary particle interactions are discussed. One of such ideas is the conception of space-time geometry. In this connection experimental measurement methods are analyzed. It is shown that measure procedures are the origin of geometrical axioms. The connection between space symmetry properties and the conservation laws is considered
Wares, Arsalan; Elstak, Iwan
2017-01-01
The purpose of this paper is to describe the mathematics that emanates from the construction of an origami box. We first construct a simple origami box from a rectangular sheet and then discuss some of the mathematical questions that arise in the context of geometry and algebra. The activity can be used as a context for illustrating how algebra…
MacKeown, P. K.
1984-01-01
Clarifies two concepts of gravity--those of a fictitious force and those of how space and time may have geometry. Reviews the position of Newton's theory of gravity in the context of special relativity and considers why gravity (as distinct from electromagnetics) lends itself to Einstein's revolutionary interpretation. (JN)
DEFF Research Database (Denmark)
Booss-Bavnbek, Bernhelm
2011-01-01
This paper applies I.M. Gelfand's distinction between adequate and non-adequate use of mathematical language in different contexts to the newly opened window of model-based measurements of intracellular dynamics. The specifics of geometry and dynamics on the mesoscale of cell physiology are elabo...
Diophantine geometry an introduction
Hindry, Marc
2000-01-01
This is an introduction to diophantine geometry at the advanced graduate level. The book contains a proof of the Mordell conjecture which will make it quite attractive to graduate students and professional mathematicians. In each part of the book, the reader will find numerous exercises.
Sliding vane geometry turbines
Sun, Harold Huimin; Zhang, Jizhong; Hu, Liangjun; Hanna, Dave R
2014-12-30
Various systems and methods are described for a variable geometry turbine. In one example, a turbine nozzle comprises a central axis and a nozzle vane. The nozzle vane includes a stationary vane and a sliding vane. The sliding vane is positioned to slide in a direction substantially tangent to an inner circumference of the turbine nozzle and in contact with the stationary vane.
Boyer, Carl B
2012-01-01
Designed as an integrated survey of the development of analytic geometry, this study presents the concepts and contributions from before the Alexandrian Age through the eras of the great French mathematicians Fermat and Descartes, and on through Newton and Euler to the "Golden Age," from 1789 to 1850.
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.
International Nuclear Information System (INIS)
Ezin, J.P.
1988-08-01
The lectures given at the ''5th Symposium of Mathematics in Abidjan: Differential Geometry and Mechanics'' are presented. They are divided into four chapters: Riemannian metric on a differential manifold, curvature tensor fields on a Riemannian manifold, some classical functionals on Riemannian manifolds and questions. 11 refs
Hartshorne, Robin
2000-01-01
In recent years, I have been teaching a junior-senior-level course on the classi cal geometries. This book has grown out of that teaching experience. I assume only high-school geometry and some abstract algebra. The course begins in Chapter 1 with a critical examination of Euclid's Elements. Students are expected to read concurrently Books I-IV of Euclid's text, which must be obtained sepa rately. The remainder of the book is an exploration of questions that arise natu rally from this reading, together with their modern answers. To shore up the foundations we use Hilbert's axioms. The Cartesian plane over a field provides an analytic model of the theory, and conversely, we see that one can introduce coordinates into an abstract geometry. The theory of area is analyzed by cutting figures into triangles. The algebra of field extensions provides a method for deciding which geometrical constructions are possible. The investigation of the parallel postulate leads to the various non-Euclidean geometries. And ...
International Nuclear Information System (INIS)
Chen, Chun; Li, Dianfu; Miao, Changqing; Zhou, Yanli; Cao, Kejiang; Feng, Jianlin; Lloyd, Michael S.; Chen, Ji
2012-01-01
The purpose of this study was to evaluate left ventricular (LV) mechanical dyssynchrony in patients with Wolff-Parkinson-White (WPW) syndrome pre- and post-radiofrequency catheter ablation (RFA) using phase analysis of gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). Forty-five WPW patients were enrolled and had gated SPECT MPI pre- and 2-3 days post-RFA. Electrophysiological study (EPS) was used to locate accessory pathways (APs) and categorize the patients according to the AP locations (septal, left and right free wall). Electrocardiography (ECG) was performed pre- and post-RFA to confirm successful elimination of the APs. Phase analysis of gated SPECT MPI was used to assess LV dyssynchrony pre- and post-RFA. Among the 45 patients, 3 had gating errors, and thus 42 had SPECT phase analysis. Twenty-two patients (52.4 %) had baseline LV dyssynchrony. Baseline LV dyssynchrony was more prominent in the patients with septal APs than in the patients with left or right APs (p < 0.05). RFA improved LV synchrony in the entire cohort and in the patients with septal APs (p < 0.01). Phase analysis of gated SPECT MPI demonstrated that LV mechanical dyssynchrony can be present in patients with WPW syndrome. Septal APs result in the greatest degree of LV mechanical dyssynchrony and afford the most benefit after RFA. This study supports further investigation in the relationship between electrical and mechanical activation using EPS and phase analysis of gated SPECT MPI. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Chen, Chun; Li, Dianfu; Miao, Changqing; Zhou, Yanli; Cao, Kejiang [First Affiliated Hospital of Nanjing Medical University, Department of Cardiology, Nanjing, Jiangsu (China); Feng, Jianlin [First Affiliated Hospital of Nanjing Medical University, Department of Nuclear Medicine, Nanjing, Jiangsu (China); Lloyd, Michael S. [Emory University School of Medicine, Division of Cardiology, Atlanta, GA (United States); Chen, Ji [Emory University School of Medicine, Department of Radiology and Imaging Sciences, Atlanta, GA (United States)
2012-07-15
The purpose of this study was to evaluate left ventricular (LV) mechanical dyssynchrony in patients with Wolff-Parkinson-White (WPW) syndrome pre- and post-radiofrequency catheter ablation (RFA) using phase analysis of gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). Forty-five WPW patients were enrolled and had gated SPECT MPI pre- and 2-3 days post-RFA. Electrophysiological study (EPS) was used to locate accessory pathways (APs) and categorize the patients according to the AP locations (septal, left and right free wall). Electrocardiography (ECG) was performed pre- and post-RFA to confirm successful elimination of the APs. Phase analysis of gated SPECT MPI was used to assess LV dyssynchrony pre- and post-RFA. Among the 45 patients, 3 had gating errors, and thus 42 had SPECT phase analysis. Twenty-two patients (52.4 %) had baseline LV dyssynchrony. Baseline LV dyssynchrony was more prominent in the patients with septal APs than in the patients with left or right APs (p < 0.05). RFA improved LV synchrony in the entire cohort and in the patients with septal APs (p < 0.01). Phase analysis of gated SPECT MPI demonstrated that LV mechanical dyssynchrony can be present in patients with WPW syndrome. Septal APs result in the greatest degree of LV mechanical dyssynchrony and afford the most benefit after RFA. This study supports further investigation in the relationship between electrical and mechanical activation using EPS and phase analysis of gated SPECT MPI. (orig.)
Lee, Ji-Hyun; Momani, Jalal; Kim, Young Mog; Kang, Chang-Keun; Choi, Jung-Hwa; Baek, Hae-Ja; Kim, Hyun-Woo
2015-01-01
Myostatin (MSTN), also known as GDF8, is a member of the transforming growth factor-β (TGF-β) superfamily and plays an important role in muscle growth, development, and differentiation. Recently, Lv-MSTN/GDF11, the primitive isoform of MSTN and GDF11, was identified from the shrimp Litopenaeus vannamei. The major production site for Lv-MSTN/GDF11 is in the heart, not the tail muscle, which differs from MSTNs in mammals. Among the three injected RNAs, long dsRNA was the most effective for Lv-MSTN/GDF11 knockdown and transcripts of Lv-MSTN/GDF11 decreased in both the heart (88.85%) and skeletal muscles (43.36%) 72h after injection of 10pmol of long dsRNA. We also found that higher doses of dsRNA did not lead to greater decreases in Lv-MSTN/GDF11 transcripts for amounts between 1pmol and 100pmol. Injection of Lv-MSTN/GDF11 dsRNA did not affect the upregulation of the skeletal actin gene (Lv-ACTINSK) in the tail muscle, but the expression of cytoplasmic and cardiac actins were upregulated in both the heart and tail muscle. Over the course of 8weeks of dsRNA injection, considerably higher mortality (~71%) was seen in the dsRNA-injected group compared to the control group (40%). Surviving shrimp in the dsRNA injected group had a lower growth rate due to the adverse effects of Lv-MSTN/GDF11 knockdown. Lv-MSTN/GDF11 appears to be involved in muscular or neuronal development, but not in doubling muscle fibers, as is the case with mammalian MSTN. Copyright © 2014 Elsevier Inc. All rights reserved.
Tests of compressed geometry NEC acceleration tubes
International Nuclear Information System (INIS)
Raatz, J.E.; Rathmell, R.D.; Stelson, P.H.; Ziegler, N.F.
1985-01-01
Tests have been performed in the 3 MV Pelletron test machine at NEC on a compressed geometry tube which increases the insulating length of the tube by eliminating the heated electrode assemblies (approx.2.5 cm thick) at the end of each tube section. Some insert electrodes are changed to provide some trapping of secondary ions. The geometry tested provided an 18% increase in live ceramic in the tube. The compressed geometry tube allowed a terminal voltage of 3.55 MV on the 3 MV column at normal gradients of 30.3 kv/tube gap. The tube was also conditioned to more than 4 MV and remained stable in voltage with few sparks and with low x-ray levels for days at about 4 MV. This same performance could be achieved with or without arc discharge cleaning. 4 refs., 4 figs
Multivariate calculus and geometry
Dineen, Seán
2014-01-01
Multivariate calculus can be understood best by combining geometric insight, intuitive arguments, detailed explanations and mathematical reasoning. This textbook has successfully followed this programme. It additionally provides a solid description of the basic concepts, via familiar examples, which are then tested in technically demanding situations. In this new edition the introductory chapter and two of the chapters on the geometry of surfaces have been revised. Some exercises have been replaced and others provided with expanded solutions. Familiarity with partial derivatives and a course in linear algebra are essential prerequisites for readers of this book. Multivariate Calculus and Geometry is aimed primarily at higher level undergraduates in the mathematical sciences. The inclusion of many practical examples involving problems of several variables will appeal to mathematics, science and engineering students.
Transformational plane geometry
Umble, Ronald N
2014-01-01
Axioms of Euclidean Plane Geometry The Existence and Incidence Postulates The Distance and Ruler Postulates The Plane Separation Postulate The Protractor Postulate The Side-Angle-Side Postulate and the Euclidean Parallel Postulate Theorems of Euclidean Plane Geometry The Exterior Angle Theorem Triangle Congruence Theorems The Alternate Interior Angles Theorem and the Angle Sum Theorem Similar Triangles Introduction to Transformations, Isometries, and Similarities Transformations Isometries and SimilaritiesAppendix: Proof of Surjectivity Translations, Rotations, and Reflections Translations Rotations Reflections Appendix: Geometer's Sketchpad Commands Required by Exploratory Activities Compositions of Translations, Rotations, and Reflections The Three Points Theorem Rotations as Compositions of Two Reflections Translations as Compositions of Two Halfturns or Two Reflections The Angle Addition Theorem Glide Reflections Classification of Isometries The Fundamental Theorem and Congruence Classification of Isometr...
Multilevel geometry optimization
Rodgers, Jocelyn M.; Fast, Patton L.; Truhlar, Donald G.
2000-02-01
Geometry optimization has been carried out for three test molecules using six multilevel electronic structure methods, in particular Gaussian-2, Gaussian-3, multicoefficient G2, multicoefficient G3, and two multicoefficient correlation methods based on correlation-consistent basis sets. In the Gaussian-2 and Gaussian-3 methods, various levels are added and subtracted with unit coefficients, whereas the multicoefficient Gaussian-x methods involve noninteger parameters as coefficients. The multilevel optimizations drop the average error in the geometry (averaged over the 18 cases) by a factor of about two when compared to the single most expensive component of a given multilevel calculation, and in all 18 cases the accuracy of the atomization energy for the three test molecules improves; with an average improvement of 16.7 kcal/mol.
Multilevel geometry optimization
Energy Technology Data Exchange (ETDEWEB)
Rodgers, Jocelyn M. [Department of Chemistry and Supercomputer Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431 (United States); Fast, Patton L. [Department of Chemistry and Supercomputer Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431 (United States); Truhlar, Donald G. [Department of Chemistry and Supercomputer Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431 (United States)
2000-02-15
Geometry optimization has been carried out for three test molecules using six multilevel electronic structure methods, in particular Gaussian-2, Gaussian-3, multicoefficient G2, multicoefficient G3, and two multicoefficient correlation methods based on correlation-consistent basis sets. In the Gaussian-2 and Gaussian-3 methods, various levels are added and subtracted with unit coefficients, whereas the multicoefficient Gaussian-x methods involve noninteger parameters as coefficients. The multilevel optimizations drop the average error in the geometry (averaged over the 18 cases) by a factor of about two when compared to the single most expensive component of a given multilevel calculation, and in all 18 cases the accuracy of the atomization energy for the three test molecules improves; with an average improvement of 16.7 kcal/mol. (c) 2000 American Institute of Physics.
Krauss, Lawrence M.; Turner, Michael S.
1999-01-01
The recognition that the cosmological constant may be non-zero forces us to re-evaluate standard notions about the connection between geometry and the fate of our Universe. An open Universe can recollapse, and a closed Universe can expand forever. As a corollary, we point out that there is no set of cosmological observations we can perform that will unambiguously allow us to determine what the ultimate destiny of the Universe will be.
DEFF Research Database (Denmark)
Tamke, Martin; Ramsgaard Thomsen, Mette; Riiber Nielsen, Jacob
2009-01-01
The versatility of wood constructions and traditional wood joints for the production of non standard elements was in focus of a design based research. Herein we established a seamless process from digital design to fabrication. A first research phase centered on the development of a robust...... parametric model and a generic design language a later explored the possibilities to construct complex shaped geometries with self registering joints on modern wood crafting machines. The research was carried out as collaboration with industrial partners....
International Nuclear Information System (INIS)
Lepora, N.; Kibble, T.
1999-01-01
We analyse symmetry breaking in the Weinberg-Salam model paying particular attention to the underlying geometry of the theory. In this context we find two natural metrics upon the vacuum manifold: an isotropic metric associated with the scalar sector, and a squashed metric associated with the gauge sector. Physically, the interplay between these metrics gives rise to many of the non-perturbative features of Weinberg-Salam theory. (author)
Directory of Open Access Journals (Sweden)
G. Göransson
2013-07-01
Full Text Available The turbidity variation in time and space is investigated in the downstream stretch of the river Göta Älv in Sweden. The river is heavily regulated and carries the discharge from the largest fresh water lake in Sweden, Lake Vänern, to the outflow point in Göteborg Harbour on the Swedish west coast. The river is an important waterway and serves as a fresh-water supply for 700 000 users. Turbidity is utilised as a water quality indicator to ensure sufficient quality of the intake water to the treatment plant. The overall objective of the study was to investigate the influence of rainfall, surface runoff, and river water flow on the temporal and spatial variability of the turbidity in the regulated river system by employing statistical analysis of an extensive data set. A six year long time series of daily mean values on precipitation, discharge, and turbidity from six stations along the river were examined primarily through linear correlation and regression analysis, combined with nonparametric tests and analysis of variance. The analyses were performed on annual, monthly, and daily bases, establishing temporal patterns and dependences, including; seasonal changes, impacts from extreme events, influences from tributaries, and the spatial variation along the river. The results showed that there is no simple relationship between discharge, precipitation, and turbidity, mainly due to the complexity of the runoff process, the regulation of the river, and the effects of Lake Vänern and its large catchment area. For the river Göta Älv, significant, positive correlations between turbidity, discharge, and precipitation could only be found during periods with high flow combined with heavy rainfall. Local precipitation does not seem to have any significant impact on the discharge in the main river, which is primarily governed by precipitation at catchment scale. The discharge from Lake Vänern determines the base level for the turbidity in the river
International Nuclear Information System (INIS)
Hull, C.M.
1993-01-01
The geometric structure of theories with gauge fields of spins two and higher should involve a higher spin generalisation of Riemannian geometry. Such geometries are discussed and the case of W ∝ -gravity is analysed in detail. While the gauge group for gravity in d dimensions is the diffeomorphism group of the space-time, the gauge group for a certain W-gravity theory (which is W ∝ -gravity in the case d=2) is the group of symplectic diffeomorphisms of the cotangent bundle of the space-time. Gauge transformations for W-gravity gauge fields are given by requiring the invariance of a generalised line element. Densities exist and can be constructed from the line element (generalising √detg μν ) only if d=1 or d=2, so that only for d=1,2 can actions be constructed. These two cases and the corresponding W-gravity actions are considered in detail. In d=2, the gauge group is effectively only a subgroup of the symplectic diffeomorphisms group. Some of the constraints that arise for d=2 are similar to equations arising in the study of self-dual four-dimensional geometries and can be analysed using twistor methods, allowing contact to be made with other formulations of W-gravity. While the twistor transform for self-dual spaces with one Killing vector reduces to a Legendre transform, that for two Killing vectors gives a generalisation of the Legendre transform. (orig.)
Integral geometry and valuations
Solanes, Gil
2014-01-01
Valuations are finitely additive functionals on the space of convex bodies. Their study has become a central subject in convexity theory, with fundamental applications to integral geometry. In the last years there has been significant progress in the theory of valuations, which in turn has led to important achievements in integral geometry. This book originated from two courses delivered by the authors at the CRM and provides a self-contained introduction to these topics, covering most of the recent advances. The first part, by Semyon Alesker, is devoted to the theory of convex valuations, with emphasis on the latest developments. A special focus is put on the new fundamental structures of the space of valuations discovered after Alesker's irreducibility theorem. Moreover, the author describes the newly developed theory of valuations on manifolds. In the second part, Joseph H. G. Fu gives a modern introduction to integral geometry in the sense of Blaschke and Santaló, based on the notions and tools presented...
CBM RICH geometry optimization
Energy Technology Data Exchange (ETDEWEB)
Mahmoud, Tariq; Hoehne, Claudia [II. Physikalisches Institut, Giessen Univ. (Germany); Collaboration: CBM-Collaboration
2016-07-01
The Compressed Baryonic Matter (CBM) experiment at the future FAIR complex will investigate the phase diagram of strongly interacting matter at high baryon density and moderate temperatures in A+A collisions from 2-11 AGeV (SIS100) beam energy. The main electron identification detector in the CBM experiment will be a RICH detector with a CO{sub 2} gaseous-radiator, focusing spherical glass mirrors, and MAPMT photo-detectors being placed on a PMT-plane. The RICH detector is located directly behind the CBM dipole magnet. As the final magnet geometry is now available, some changes in the RICH geometry become necessary. In order to guarantee a magnetic field of 1 mT at maximum in the PMT plane for effective operation of the MAPMTs, two measures have to be taken: The PMT plane is moved outwards of the stray field by tilting the mirrors by 10 degrees and shielding boxes have been designed. In this contribution the results of the geometry optimization procedure are presented.
Introducing geometry concept based on history of Islamic geometry
Maarif, S.; Wahyudin; Raditya, A.; Perbowo, K. S.
2018-01-01
Geometry is one of the areas of mathematics interesting to discuss. Geometry also has a long history in mathematical developments. Therefore, it is important integrated historical development of geometry in the classroom to increase’ knowledge of how mathematicians earlier finding and constructing a geometric concept. Introduction geometrical concept can be started by introducing the Muslim mathematician who invented these concepts so that students can understand in detail how a concept of geometry can be found. However, the history of mathematics development, especially history of Islamic geometry today is less popular in the world of education in Indonesia. There are several concepts discovered by Muslim mathematicians that should be appreciated by the students in learning geometry. Great ideas of mathematicians Muslim can be used as study materials to supplement religious character values taught by Muslim mathematicians. Additionally, by integrating the history of geometry in teaching geometry are expected to improve motivation and geometrical understanding concept.
Broer, H.; Hoveijn, I.; Lunter, G.; Vegter, G.
2003-01-01
The Birkhoff normal form procedure is a widely used tool for approximating a Hamiltonian systems by a simpler one. This chapter starts out with an introduction to Hamiltonian mechanics, followed by an explanation of the Birkhoff normal form procedure. Finally we discuss several algorithms for
Two lectures on D-geometry and noncommutative geometry
International Nuclear Information System (INIS)
Douglas, M.R.
1999-01-01
This is a write-up of lectures given at the 1998 Spring School at the Abdus Salam ICTP. We give a conceptual introduction to D-geometry, the study of geometry as seen by D-branes in string theory, and to noncommutative geometry as it has appeared in D-brane and Matrix theory physics. (author)
DEFF Research Database (Denmark)
Hashemi Toghroljerdi, Seyedmostafa; Østergaard, Jacob; Yang, Guangya
2014-01-01
In this paper a new method is proposed to determine the minimum energy storage required to be installed at different locations of a low voltage (LV) grid in order to prevent the overvoltage due to high residential photovoltaic (PV) penetration. The method is based on the voltage sensitivity...... with different occurrence probabilities without involving the time-series studies problems. The proposed method is capable of modeling output power of PV panels with different orientations as well as different electric vehicle (EV) charging patterns....
Directory of Open Access Journals (Sweden)
Fernanda V.A. da Costa
Full Text Available ABSTRACT: Using a retrospective study, 493 cats tested for FeLV and FIV were selected for analysis of the association between hematologic findings and positivity at immunoassay test. Individual and hematologic variables were assessed considering the influence of results using univariate and multivariate logistic regression analysis. Out 153 of the 493 cats were positive for FeLV (31%, 50 were positive for FIV (10.1% and 22 were positive for both FIV and FeLV (4.4%. Multivariate analysis detected significant associations between FeLV infection and age below 1 year (p=0.01, age from 1 to 10 years (p=0.03, and crossbreed (p=0.04. Male cats were more likely to be FIV-positive (p=0.002. Regarding hematological changes, FeLV-positive cats have higher odds to anemia, leukopenia and lymphopenia than FeLV-negative cats. FIV-positive cats are more likely to have anemia than negative. Identification of associated factors related to animal status and correlation of hematological disorders with infection by retroviruses in cats could be useful for detecting these retroviral diseases in cats.
Directory of Open Access Journals (Sweden)
Pei-Hui Wang
Full Text Available The Toll-like receptor (TLR-mediated NF-κB pathway is tightly controlled because overactivation may result in severe damage to the host, such as in the case of chronic inflammatory diseases and cancer. In mammals, sterile-alpha and armadillo motif-containing protein (SARM plays an important role in negatively regulating this pathway. While Caenorhabditis elegans SARM is crucial for an efficient immune response against bacterial and fungal infections, it is still unknown whether Drosophila SARM participates in immune responses. Here, Litopenaeus vannamei SARM (LvSARM was cloned and functionally characterized. LvSARM shared signature domains with and exhibited significant similarities to mammalian SARM. Real-time quantitative PCR analysis indicated that the expression of LvSARM was responsive to Vibrio alginolyticus and white spot syndrome virus (WSSV infections in the hemocyte, gill, hepatopancreas and intestine. In Drosophila S2 cells, LvSARM was widely distributed in the cytoplasm and could significantly inhibit the promoters of the NF-κB pathway-controlled antimicrobial peptide genes (AMPs. Silencing of LvSARM using dsRNA-mediated RNA interference increased the expression levels of Penaeidins and antilipopolysaccharide factors, which are L.vannamei AMPs, and increased the mortality rate after V. alginolyticus infection. Taken together, our results reveal that LvSARM may be a novel component of the shrimp Toll pathway that negatively regulates shrimp AMPs, particularly Penaeidins and antilipopolysaccharide factors.
Vismane, Inese
2010-01-01
Maģistra darba tēma ir „Interneta sociālie tīkli draugiem.lv, mammam/tetiem.lv un twitter.com kā reklāmas nesēji Latvijā (2009.gads)”. Darba mērķis ir izpētīt Latvijas interneta sociālo tīklu vidi kā potenciāli augošu un reklāmai piemērotu, kā arī izpētīt pamanāmākos reklāmas gadījumus šajos portālos. Teorijas daļā tiek apskatīta Web 2.0 ēra, interneta reklāmas un sociālo mediju mārketinga īpatnības, sociālo tīklu fenomens un teorijas, Latvijas reklāmas tirgus un auditorija, kā arī sociāl...
International Nuclear Information System (INIS)
Hook, D W
2008-01-01
A geometric framework for quantum mechanics arose during the mid 1970s when authors such as Cantoni explored the notion of generalized transition probabilities, and Kibble promoted the idea that the space of pure quantum states provides a natural quantum mechanical analogue for classical phase space. This central idea can be seen easily since the projection of Schroedinger's equation from a Hilbert space into the space of pure spaces is a set of Hamilton's equations. Over the intervening years considerable work has been carried out by a variety of authors and a mature description of quantum mechanics in geometric terms has emerged with many applications. This current offering would seem ideally placed to review the last thirty years of progress and relate this to the most recent work in quantum entanglement. Bengtsson and Zyczkowski's beautifully illustrated volume, Geometry of Quantum States (referred to as GQS from now on) attempts to cover considerable ground in its 466 pages. Its topics range from colour theory in Chapter 1 to quantum entanglement in Chapter 15-to say that this is a whirlwind tour is, perhaps, no understatement. The use of the work 'introduction' in the subtitle of GQS, might suggest to the reader that this work be viewed as a textbook and I think that this interpretation would be incorrect. The authors have chosen to present a survey of different topics with the specific aim to introduce entanglement in geometric terms-the book is not intended as a pedagogical introduction to the geometric approach to quantum mechanics. Each of the fifteen chapters is a short, and mostly self-contained, essay on a particular aspect or application of geometry in the context of quantum mechanics with entanglement being addressed specifically in the final chapter. The chapters fall into three classifications: those concerned with the mathematical background, those which discuss quantum theory and the foundational aspects of the geometric framework, and
Functional integration over geometries
International Nuclear Information System (INIS)
Mottola, E.
1995-01-01
The geometric construction of the functional integral over coset spaces M/G is reviewed. The inner product on the cotangent space of infinitesimal deformations of M defines an invariant distance and volume form, or functional integration measure on the full configuration space. Then, by a simple change of coordinates parameterizing the gauge fiber G, the functional measure on the coset space M/G is deduced. This change of integration variables leads to a Jacobian which is entirely equivalent to the Faddeev--Popov determinant of the more traditional gauge fixed approach in non-abelian gauge theory. If the general construction is applied to the case where G is the group of coordinate reparameterizations of spacetime, the continuum functional integral over geometries, i.e. metrics modulo coordinate reparameterizations may be defined. The invariant functional integration measure is used to derive the trace anomaly and effective action for the conformal part of the metric in two and four dimensional spacetime. In two dimensions this approach generates the Polyakov--Liouville action of closed bosonic non-critical string theory. In four dimensions the corresponding effective action leads to novel conclusions on the importance of quantum effects in gravity in the far infrared, and in particular, a dramatic modification of the classical Einstein theory at cosmological distance scales, signaled first by the quantum instability of classical de Sitter spacetime. Finite volume scaling relations for the functional integral of quantum gravity in two and four dimensions are derived, and comparison with the discretized dynamical triangulation approach to the integration over geometries are discussed. Outstanding unsolved problems in both the continuum definition and the simplicial approach to the functional integral over geometries are highlighted
Dooner, David B
2012-01-01
Building on the first edition published in 1995 this new edition of Kinematic Geometry of Gearing has been extensively revised and updated with new and original material. This includes the methodology for general tooth forms, radius of torsure', cylinder of osculation, and cylindroid of torsure; the author has also completely reworked the '3 laws of gearing', the first law re-written to better parallel the existing 'Law of Gearing" as pioneered by Leonard Euler, expanded from Euler's original law to encompass non-circular gears and hypoid gears, the 2nd law of gearing describing a unique relat
Flegg, H Graham
2001-01-01
This excellent introduction to topology eases first-year math students and general readers into the subject by surveying its concepts in a descriptive and intuitive way, attempting to build a bridge from the familiar concepts of geometry to the formalized study of topology. The first three chapters focus on congruence classes defined by transformations in real Euclidean space. As the number of permitted transformations increases, these classes become larger, and their common topological properties become intuitively clear. Chapters 4-12 give a largely intuitive presentation of selected topics.
Torsional heterotic geometries
International Nuclear Information System (INIS)
Becker, Katrin; Sethi, Savdeep
2009-01-01
We construct new examples of torsional heterotic backgrounds using duality with orientifold flux compactifications. We explain how duality provides a perturbative solution to the type I/heterotic string Bianchi identity. The choice of connection used in the Bianchi identity plays an important role in the construction. We propose the existence of a much larger landscape of compact torsional geometries using string duality. Finally, we present some quantum exact metrics that correspond to NS5-branes placed on an elliptic space. These metrics describe how torus isometries are broken by NS flux.
Geometrie verstehen: statisch - kinematisch
Kroll, Ekkehard
Dem Allgemeinen steht begrifflich das Besondere gegenüber. In diesem Sinne sind allgemeine Überlegungen zum Verstehen von Mathematik zu ergänzen durch Untersuchungen hinsichtlich des Verstehens der einzelnen mathematischen Disziplinen, insbesondere der Geometrie. Hier haben viele Schülerinnen und Schüler Probleme. Diese rühren hauptsächlich daher, dass eine fertige geometrische Konstruktion in ihrer statischen Präsentation auf Papier nicht mehr die einzelnen Konstruktionsschritte erkennen lässt; zum Nachvollzug müssen sie daher ergänzend in einer Konstruktionsbeschreibung festgehalten werden.
Kendig, Keith
2015-01-01
Designed to make learning introductory algebraic geometry as easy as possible, this text is intended for advanced undergraduates and graduate students who have taken a one-year course in algebra and are familiar with complex analysis. This newly updated second edition enhances the original treatment's extensive use of concrete examples and exercises with numerous figures that have been specially redrawn in Adobe Illustrator. An introductory chapter that focuses on examples of curves is followed by a more rigorous and careful look at plane curves. Subsequent chapters explore commutative ring th
Abhyankar, Shreeram Shankar
1964-01-01
This book provides, for use in a graduate course or for self-study by graduate students, a well-motivated treatment of several topics, especially the following: (1) algebraic treatment of several complex variables; (2) geometric approach to algebraic geometry via analytic sets; (3) survey of local algebra; (4) survey of sheaf theory. The book has been written in the spirit of Weierstrass. Power series play the dominant role. The treatment, being algebraic, is not restricted to complex numbers, but remains valid over any complete-valued field. This makes it applicable to situations arising from
2015-01-01
This stimulating volume offers a broad collection of the principles of geometry and trigonometry and contains colorful diagrams to bring mathematical principles to life. Subjects are enriched by references to famous mathematicians and their ideas, and the stories are presented in a very comprehensible way. Readers investigate the relationships of points, lines, surfaces, and solids. They study construction methods for drawing figures, a wealth of facts about these figures, and above all, methods to prove the facts. They learn about triangle measure for circular motion, sine and cosine, tangent
REA, The Editors of
2012-01-01
REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Geometry I includes methods of proof, points, lines, planes, angles, congruent angles and line segments, triangles, parallelism, quadrilaterals, geometric inequalities, and geometric
Graded geometry and Poisson reduction
Cattaneo, A S; Zambon, M
2009-01-01
The main result of [2] extends the Marsden-Ratiu reduction theorem [4] in Poisson geometry, and is proven by means of graded geometry. In this note we provide the background material about graded geometry necessary for the proof in [2]. Further, we provide an alternative algebraic proof for the main result. ©2009 American Institute of Physics
Laboratorios virtuales (LV como apoyo a las prácticas a distancia y presenciales en ingeniería
Directory of Open Access Journals (Sweden)
Francis Castellanos
2010-01-01
Full Text Available El presente artículo tiene como propósito mostrar los procesos inherentes a cada una de las etapas de diseño y desarrollo en un Laboratorio Virtual, LV, y más específicamente para el laboratorio redes convergentes de la Institución. Durante la investigación, se desarrolló una metodología basada en los lineamientos del PMI (Project Management Institute que servirá como base para la creación de futuros laboratorios virtuales en cualquier área del conocimiento. Para el acceso de los laboratorios se desarrolló la herramienta de Software Vlab, como una plataforma integradora de laboratorios virtuales para la Institución. Los LV son simulaciones consideradas como una alternativa pedagógica para el desarrollo de prácticas a distancia o como apoyo a las prácticas en la presencialidad, que ofrecen a los estudiantes la oportunidad de adquirir destrezas y habilidades en el manejo de materiales y equipos relacionados con las áreas de su campo de formación, sin restricción de tiempo o espacio.
Project of Ariane 5 LV family advancement by use of reusable fly-back boosters (named “Bargouzine”)
Sumin, Yu.; Bonnal, Ch.; Kostromin, S.; Panichkin, N.
2007-12-01
The paper concerns possible concept variants of a partially reusable Heavy-Lift Launch Vehicle derived from the advanced basic launcher (Ariane-2010) by means of substitution of the EAP Solid Rocket Boosters for a Reusable Starting Stage consisting two Liquid-propellant Reusable Fly-Back Boosters called "Bargouzin". This paper describes the status of the presently studied RFBB concepts during its three phases. The first project phase was dedicated to feasibility expertise of liquid-rocket reusable fly-back boosters ("Baikal" type) utilization for heavy-lift space launch vehicle. The design features and main conclusions are presented. The second phase has been performed with the purpose of selection of preferable concept among the alternative ones for the future Ariane LV modernization by using RFBB instead of EAP Boosters. The main requirements, logic of work, possible configuration and conclusion are presented. Initial aerodynamic, ballistic, thermoloading, dynamic loading, trade-off and comparison analysis have been performed on these concepts. The third phase consists in performing a more detailed expertise of the chosen LV concept. This part summarizes some of the more detailed results related to flight performance, system mass, thermoprotection system, aspects of technologies, ground complex modification, comparison analyses and conclusion.
Evaluation of early systolic flow pattern in left ventricle by tagging cine MRI in normal volunteers
International Nuclear Information System (INIS)
Sakakura, Kazuyoshi; Anno, Naoko; Kondo, Takeshi
1992-01-01
The tagging method is a new technique, which permits to apply discretionary lines (tags) on MR images. To evaluate intra left ventricular (LV) flow pattern, we performed ECG-gated gradient field echo cine MRI using tagging method in five normal male volunteers, aged 22-42 years. The horizontal long axis view of LV was imaged by multiphasic field echo pulse sequence. The three parallel tags (basal, middle and apical portion) were established on the horizontal long axis view of LV just after the triggered QRS waves. And the initial two images (70 ms and 120 ms after the triggered QRS waves) were analyzed. On the two tags (middle and apical portion) of these three tags, we measured the distance of displacement of the tags on three points (the near site of IVS, middle portion and the near site of free wall) respectively. At 70 ms after the trigger point, the only tagged blood at the near site of free wall flowed toward the apex. At 120 ms after the trigger point, all the tagged blood flowed toward the outflow tract of LV. And the maximum blood flow velocity was observed at the near site of IVS on middle portion of LV (166.0 mm/s). These results coincided with earlier studies by Doppler echocardiography. But we could not observe intra LV blood flow patterns throughout one cardiac cycle in this pulse sequence, because the tags had flowed out from LV and had become unclear due to spin relaxation and mixing. We concluded that the tagging method was useful to evaluate intra left ventricular blood flow patterns in early systolic phase. (author)
Sukhumavasi, Woraporn; Bellosa, Mary L; Lucio-Forster, Araceli; Liotta, Janice L; Lee, Alice C Y; Pornmingmas, Pitcha; Chungpivat, Sudchit; Mohammed, Hussni O; Lorentzen, Leif; Dubey, J P; Bowman, Dwight D
2012-08-13
The seroprevalence of Toxoplasma gondii, Dirofilaria immitis (heartworm), feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) infections was examined using serum or plasma samples from 746 pet cats collected between May and July 2009 from clinics and hospitals located in and around Bangkok, Thailand. The samples were tested for heartworm, FIV, and FeLV using a commercial ELISA. Of the 746 samples, 4.6% (34/746) were positive for heartworm antigen, 24.5% (183/746) had circulating FeLV antigen, and 20.1% (150/746) had antibodies against FIV. In addition, the first 348 submitted samples were tested for T. gondii antibodies using a modified agglutination test (MAT, cut off 1:25); 10.1% (35/348) were seropositive. Of the 348 cats sampled for all four pathogens, 11, 10, and 1 were positive for T. gondii antibodies and FIV antibodies, FeLV antigen, or D. immitis antigen, respectively. Of the 35 T. gondii-seropositive cats, 42.9% (15/35) were co-infected with at least one of the other three pathogens. The presence of antibodies to FIV was significantly associated with both age and gender, while FeLV antigen presence was only associated with age. In the case of FIV, males were twice as likely to be infected as females, and cats over 10 years of age were 13.5 times more likely to be infected than cats less than 1 year of age. FeLV antigen was more common in younger cats, with cats over 10 years of age being 10 times less likely to be FeLV positive than cats under 1 year of age. This is the first survey for these four pathogens affecting feline health in Thailand. Copyright © 2012 Elsevier B.V. All rights reserved.
Bochnak, Jacek; Roy, Marie-Françoise
1998-01-01
This book is a systematic treatment of real algebraic geometry, a subject that has strong interrelation with other areas of mathematics: singularity theory, differential topology, quadratic forms, commutative algebra, model theory, complexity theory etc. The careful and clearly written account covers both basic concepts and up-to-date research topics. It may be used as text for a graduate course. The present edition is a substantially revised and expanded English version of the book "Géometrie algébrique réelle" originally published in French, in 1987, as Volume 12 of ERGEBNISSE. Since the publication of the French version the theory has made advances in several directions. Many of these are included in this English version. Thus the English book may be regarded as a completely new treatment of the subject.
Critique of information geometry
International Nuclear Information System (INIS)
Skilling, John
2014-01-01
As applied to probability, information geometry fails because probability distributions do not form a metric space. Probability theory rests on a compelling foundation of elementary symmetries, which also support information (aka minus entropy, Kullback-Leibler) H(p;q) as the unique measure of divergence from source probability distribution q to destination p. Because the only compatible connective H is from≠to asymmetric, H(p;q)≠H(q;p), there can be no compatible geometrical distance (which would necessarily be from=to symmetric). Hence there is no distance relationship compatible with the structure of probability theory. Metrics g and densities sqrt(det(g)) interpreted as prior probabilities follow from the definition of distance, and must fail likewise. Various metrics and corresponding priors have been proposed, Fisher's being the most popular, but all must behave unacceptably. This is illustrated with simple counter-examples
International Nuclear Information System (INIS)
Correa, Diego H.; Silva, Guillermo A.
2008-01-01
We discuss how geometrical and topological aspects of certain (1/2)-BPS type IIB geometries are captured by their dual operators in N = 4 Super Yang-Mills theory. The type IIB solutions are characterized by arbitrary droplet pictures in a plane and we consider, in particular, axially symmetric droplets. The 1-loop anomalous dimension of the dual gauge theory operators probed with single traces is described by some bosonic lattice Hamiltonians. These Hamiltonians are shown to encode the topology of the droplets. In appropriate BMN limits, the Hamiltonians spectrum reproduces the spectrum of near-BPS string excitations propagating along each of the individual edges of the droplet. We also study semiclassical regimes for the Hamiltonians. For droplets having disconnected constituents, the Hamiltonian admits different complimentary semiclassical descriptions, each one replicating the semiclassical description for closed strings extending in each of the constituents
Emergent geometry of membranes
Energy Technology Data Exchange (ETDEWEB)
Badyn, Mathias Hudoba de; Karczmarek, Joanna L.; Sabella-Garnier, Philippe; Yeh, Ken Huai-Che [Department of Physics and Astronomy, University of British Columbia,6224 Agricultural Road, Vancouver (Canada)
2015-11-13
In work http://dx.doi.org/10.1103/PhysRevD.86.086001, a surface embedded in flat ℝ{sup 3} is associated to any three hermitian matrices. We study this emergent surface when the matrices are large, by constructing coherent states corresponding to points in the emergent geometry. We find the original matrices determine not only shape of the emergent surface, but also a unique Poisson structure. We prove that commutators of matrix operators correspond to Poisson brackets. Through our construction, we can realize arbitrary noncommutative membranes: for example, we examine a round sphere with a non-spherically symmetric Poisson structure. We also give a natural construction for a noncommutative torus embedded in ℝ{sup 3}. Finally, we make remarks about area and find matrix equations for minimal area surfaces.
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...
On organizing principles of discrete differential geometry. Geometry of spheres
International Nuclear Information System (INIS)
Bobenko, Alexander I; Suris, Yury B
2007-01-01
Discrete differential geometry aims to develop discrete equivalents of the geometric notions and methods of classical differential geometry. This survey contains a discussion of the following two fundamental discretization principles: the transformation group principle (smooth geometric objects and their discretizations are invariant with respect to the same transformation group) and the consistency principle (discretizations of smooth parametrized geometries can be extended to multidimensional consistent nets). The main concrete geometric problem treated here is discretization of curvature-line parametrized surfaces in Lie geometry. Systematic use of the discretization principles leads to a discretization of curvature-line parametrization which unifies circular and conical nets.
Higher geometry an introduction to advanced methods in analytic geometry
Woods, Frederick S
2005-01-01
For students of mathematics with a sound background in analytic geometry and some knowledge of determinants, this volume has long been among the best available expositions of advanced work on projective and algebraic geometry. Developed from Professor Woods' lectures at the Massachusetts Institute of Technology, it bridges the gap between intermediate studies in the field and highly specialized works.With exceptional thoroughness, it presents the most important general concepts and methods of advanced algebraic geometry (as distinguished from differential geometry). It offers a thorough study
Directory of Open Access Journals (Sweden)
AR Moaref1
2008-03-01
Full Text Available Background: Right ventricular apical (RVA pacing has been reported to induce several deleterious effects particularly in the presence of structural heart disease but can also involve patients with normal left ventricular (LV function. Left atrial (LA enlargement is one of these effects, but the majority of studies have measured LA dimension rather than volume.Objective: The present prospective study was designed to assess the effect of RVA pacing on LA volume in patients with normal LV function.Patients and Methods: The study comprised 41 consecutive patients with LV ejection fraction ≥ 45% and LV end diastolic dimension ≤ 56 mm who underwent single-or dual- chamber pacemaker implantation in RVA and followed for LA volume measurement and pacemaker analysis at least during the ensuing 4.2 months. Results: In all, 21 patients were excluded from the study due to five spontaneous wide QRS complex (≥120msec, one recent acute coronary syndrome,one significant valvular heart disease, three pacing frequency <90%, eight death or losing follow up in three cases. In remaining 20 patients, LA volume ragned from 21 to 54 mm3 with mean of 37.3±9.7 mm3 prior to pacemaker implantation that increased to 31 to 103 mm3 (54.3±17.0 during follow-up (P<0.001.Conclusion: RVA pacing might lead to an increase in LA volume even in patients with normal LV function.
International Nuclear Information System (INIS)
Maddahi, J.; Ostrzega, E.; Crues, J.; Honma, H.; Siegel, R.; Charuzi, Y.; Berman, D.
1987-01-01
Cine MR imaging was performed on 15 normal subjects and 27 patients with cardiac disease. In normal subjects, high signal intensity of flowing blood contrasted with that of the myocardium. In 16 patients with valvular regurgitation, signal void jet due to turbulence was visualized across the diseased valves. In three IHSS patients, thickened LV myocardium, mitral regurgitant jets, and systolic LV outflow jets were noted. Five patients with myocardial infarction (MI) showed thinning and/or hypokinesis of MI regions. In three patients with Marfan syndrome, aortic dilatation, insufficiency, and flap (one pt) were identified. Cine MR imaging is potentially useful for evaluation of a variety of cardiac diseases
Energy Technology Data Exchange (ETDEWEB)
Ferro, Adele; Salvatore, Marco; Cuocolo, Alberto [University Federico II, Department of Biomorphological and Functional Sciences, Institute of Biostructure and Bioimages of the National Council of Research, Naples (Italy); Duilio, Carlo; Santomauro, Maurizio [University Federico II, Department of Clinical Medicine, Cardiovascular and Immunological Sciences, Naples (Italy)
2005-09-01
Dual-chamber rate-modulated pacing provides haemodynamic benefits compared with ventricular pacing at rest, but it is unclear whether this also holds true during physical exercise in patients with heart failure. This study assessed the haemodynamic response to a walk test during dual-chamber pacing and ventricular pacing in patients with depressed or normal left ventricular (LV) function. Twelve patients with an LV ejection fraction <50% and 11 patients with an LV ejection fraction {>=}50% underwent two randomised 6-min walk tests under dual-chamber rate-modulated pacing and ventricular pacing at a fixed rate of 70 beats/min. All patients had a dual-chamber pacemaker implanted for complete heart block. LV function was monitored by a radionuclide ambulatory system. In patients with depressed LV function, the change from dual-chamber pacing to ventricular pacing induced a decrease in end-systolic volume at the peak of the walk test (P<0.05), with no difference in end-diastolic volume. As a consequence, higher increases in LV ejection fraction (P<0.0001) and stroke volume (P<0.01) were observed during ventricular pacing. No difference in cardiac output was found between the two pacing modes. In patients with normal LV function, the change from dual-chamber pacing to ventricular pacing induced a significant decrease in cardiac output (P<0.005 at rest and P<0.05 at the peak of the walk test). Compared with dual-chamber rate-modulated pacing, ventricular pacing improves cardiac function and does not affect cardiac output during physical activity in patients with depressed LV function, whereas it impairs cardiac output in those with normal function. (orig.)
International Nuclear Information System (INIS)
Ferro, Adele; Salvatore, Marco; Cuocolo, Alberto; Duilio, Carlo; Santomauro, Maurizio
2005-01-01
Dual-chamber rate-modulated pacing provides haemodynamic benefits compared with ventricular pacing at rest, but it is unclear whether this also holds true during physical exercise in patients with heart failure. This study assessed the haemodynamic response to a walk test during dual-chamber pacing and ventricular pacing in patients with depressed or normal left ventricular (LV) function. Twelve patients with an LV ejection fraction <50% and 11 patients with an LV ejection fraction ≥50% underwent two randomised 6-min walk tests under dual-chamber rate-modulated pacing and ventricular pacing at a fixed rate of 70 beats/min. All patients had a dual-chamber pacemaker implanted for complete heart block. LV function was monitored by a radionuclide ambulatory system. In patients with depressed LV function, the change from dual-chamber pacing to ventricular pacing induced a decrease in end-systolic volume at the peak of the walk test (P<0.05), with no difference in end-diastolic volume. As a consequence, higher increases in LV ejection fraction (P<0.0001) and stroke volume (P<0.01) were observed during ventricular pacing. No difference in cardiac output was found between the two pacing modes. In patients with normal LV function, the change from dual-chamber pacing to ventricular pacing induced a significant decrease in cardiac output (P<0.005 at rest and P<0.05 at the peak of the walk test). Compared with dual-chamber rate-modulated pacing, ventricular pacing improves cardiac function and does not affect cardiac output during physical activity in patients with depressed LV function, whereas it impairs cardiac output in those with normal function. (orig.)
Directory of Open Access Journals (Sweden)
Potabashniy V.A.
2016-05-01
Full Text Available The aim of this study was to examine the direction of change of left ventricle (LV geometry in patients with chronic heart failure (CHF, arterial hypertension (AH and ischemic heart disease (IHD in combination with chronic obstructive pulmonary disease (COPD in dependence on severity of clinical signs of CHF and COPD based on recommendation of American Society of Echocardiography and European Association of Cardiovascular Images (2015. We examined 67 patients with CHF, associated with AH and stable IHD and stable COPD. By the results of this study there were determined different types of left ventricle geometry: concentric LV hypertrophy (LVH, eccentric LVH, mixed LVH, dilated LVH, dependent on blood pressure level, fibrosic and ischemic myocardial changes,, primary predominant disease – AH, IHD or COPD.
Chen, Chun; Li, Dianfu; Miao, Changqing; Feng, Jianlin; Zhou, Yanli; Cao, Kejiang; Lloyd, Michael S; Chen, Ji
2012-07-01
The purpose of this study was to evaluate left ventricular (LV) mechanical dyssynchrony in patients with Wolff-Parkinson-White (WPW) syndrome pre- and post-radiofrequency catheter ablation (RFA) using phase analysis of gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). Forty-five WPW patients were enrolled and had gated SPECT MPI pre- and 2-3 days post-RFA. Electrophysiological study (EPS) was used to locate accessory pathways (APs) and categorize the patients according to the AP locations (septal, left and right free wall). Electrocardiography (ECG) was performed pre- and post-RFA to confirm successful elimination of the APs. Phase analysis of gated SPECT MPI was used to assess LV dyssynchrony pre- and post-RFA. Among the 45 patients, 3 had gating errors, and thus 42 had SPECT phase analysis. Twenty-two patients (52.4%) had baseline LV dyssynchrony. Baseline LV dyssynchrony was more prominent in the patients with septal APs than in the patients with left or right APs (p syndrome. Septal APs result in the greatest degree of LV mechanical dyssynchrony and afford the most benefit after RFA. This study supports further investigation in the relationship between electrical and mechanical activation using EPS and phase analysis of gated SPECT MPI.
Directory of Open Access Journals (Sweden)
Mark James Robinson
2011-01-01
Full Text Available Xenotropic murine leukaemia virus-related virus (XMRV is a recently described retrovirus which has been claimed to infect humans and cause associated pathology. Initially identified in the US in patients with prostate cancer and subsequently in patients with chronic fatigue syndrome, doubt now exists that XMRV is a human pathogen. We studied the prevalence of genetic sequences of XMRV and related MuLV sequences in human prostate cancer, from B cell lymphoma patients and from UK blood donors. Nucleic acid was extracted from fresh prostate tissue biopsies, formalin-fixed paraffin-embedded (FFPE prostate tissue and FFPE B-cell lymphoma. The presence of XMRV-specific LTR or MuLV generic gag-like sequences was investigated by nested PCR. To control for mouse DNA contamination, a PCR that detected intracisternal A-type particle (IAP sequences was included. In addition, DNA and RNA were extracted from whole blood taken from UK blood donors and screened for XMRV sequences by real-time PCR. XMRV or MuLV-like sequences were not amplified from tissue samples. Occasionally MuLV gag and XMRV-LTR sequences were amplified from Indian prostate cancer samples, but were always detected in conjunction with contaminating murine genomic DNA. We found no evidence of XMRV or MuLV infection in the UK blood donors.
Rahaghi, Farbod N; Vegas-Sanchez-Ferrero, Gonzalo; Minhas, Jasleen K; Come, Carolyn E; De La Bruere, Isaac; Wells, James M; González, Germán; Bhatt, Surya P; Fenster, Brett E; Diaz, Alejandro A; Kohli, Puja; Ross, James C; Lynch, David A; Dransfield, Mark T; Bowler, Russel P; Ledesma-Carbayo, Maria J; San José Estépar, Raúl; Washko, George R
2017-05-01
Imaging-based assessment of cardiovascular structure and function provides clinically relevant information in smokers. Non-cardiac-gated thoracic computed tomographic (CT) scanning is increasingly leveraged for clinical care and lung cancer screening. We sought to determine if more comprehensive measures of ventricular geometry could be obtained from CT using an atlas-based surface model of the heart. Subcohorts of 24 subjects with cardiac magnetic resonance imaging (MRI) and 262 subjects with echocardiography were identified from COPDGene, a longitudinal observational study of smokers. A surface model of the heart was manually initialized, and then automatically optimized to fit the epicardium for each CT. Estimates of right and left ventricular (RV and LV) volume and free-wall curvature were then calculated and compared to structural and functional metrics obtained from MRI and echocardiograms. CT measures of RV dimension and curvature correlated with similar measures obtained using MRI. RV and LV volume obtained from CT inversely correlated with echocardiogram-based estimates of RV systolic pressure using tricuspid regurgitation jet velocity and LV ejection fraction respectively. Patients with evidence of RV or LV dysfunction on echocardiogram had larger RV and LV dimensions on CT. Logistic regression models based on demographics and ventricular measures from CT had an area under the curve of >0.7 for the prediction of elevated right ventricular systolic pressure and ventricular failure. These data suggest that non-cardiac-gated, non-contrast-enhanced thoracic CT scanning may provide insight into cardiac structure and function in smokers. Copyright © 2017. Published by Elsevier Inc.
An introduction to incidence geometry
De Bruyn, Bart
2016-01-01
This book gives an introduction to the field of Incidence Geometry by discussing the basic families of point-line geometries and introducing some of the mathematical techniques that are essential for their study. The families of geometries covered in this book include among others the generalized polygons, near polygons, polar spaces, dual polar spaces and designs. Also the various relationships between these geometries are investigated. Ovals and ovoids of projective spaces are studied and some applications to particular geometries will be given. A separate chapter introduces the necessary mathematical tools and techniques from graph theory. This chapter itself can be regarded as a self-contained introduction to strongly regular and distance-regular graphs. This book is essentially self-contained, only assuming the knowledge of basic notions from (linear) algebra and projective and affine geometry. Almost all theorems are accompanied with proofs and a list of exercises with full solutions is given at the end...
MoMuLV-ts-1: A Unique Mouse Model of Retrovirus-Induced Lymphoma Transmitted by Breast Milk
Directory of Open Access Journals (Sweden)
J. Chakraborty
2011-01-01
Full Text Available Our laboratory has developed a murine model of lymphoma via breast milk transmission of MoMuLV-ts-1 (Moloney murine leukemia virus-temperature sensitive mutant-1. Uninfected offspring suckled from infected surrogate mothers become infected and develop lymphoma. Multiple gene integration sites of ts-1 into the infected mouse genome including tacc3, aurka, ndel1, tpx2, p53, and rhamm were identified, and mRNA expressions were quantitated. These genes produce centrosomal proteins, which may be involved in abnormal chromosomal segregation leading to aneuploidy or multiploidy, thus causing lymphoma. Since there is no report to date on this retroviral model leading to centrosomal abnormality, and causing lymphoma development, this is a valuable and unique model to study the centrosomal involvement in lymphomagenesis.
Planetary Image Geometry Library
Deen, Robert C.; Pariser, Oleg
2010-01-01
The Planetary Image Geometry (PIG) library is a multi-mission library used for projecting images (EDRs, or Experiment Data Records) and managing their geometry for in-situ missions. A collection of models describes cameras and their articulation, allowing application programs such as mosaickers, terrain generators, and pointing correction tools to be written in a multi-mission manner, without any knowledge of parameters specific to the supported missions. Camera model objects allow transformation of image coordinates to and from view vectors in XYZ space. Pointing models, specific to each mission, describe how to orient the camera models based on telemetry or other information. Surface models describe the surface in general terms. Coordinate system objects manage the various coordinate systems involved in most missions. File objects manage access to metadata (labels, including telemetry information) in the input EDRs and RDRs (Reduced Data Records). Label models manage metadata information in output files. Site objects keep track of different locations where the spacecraft might be at a given time. Radiometry models allow correction of radiometry for an image. Mission objects contain basic mission parameters. Pointing adjustment ("nav") files allow pointing to be corrected. The object-oriented structure (C++) makes it easy to subclass just the pieces of the library that are truly mission-specific. Typically, this involves just the pointing model and coordinate systems, and parts of the file model. Once the library was developed (initially for Mars Polar Lander, MPL), adding new missions ranged from two days to a few months, resulting in significant cost savings as compared to rewriting all the application programs for each mission. Currently supported missions include Mars Pathfinder (MPF), MPL, Mars Exploration Rover (MER), Phoenix, and Mars Science Lab (MSL). Applications based on this library create the majority of operational image RDRs for those missions. A
Resolution, coverage, and geometry beyond traditional limits
Energy Technology Data Exchange (ETDEWEB)
Ronen, Shuki; Ferber, Ralf
1998-12-31
The presentation relates to the optimization of the image of seismic data and improved resolution and coverage of acquired data. Non traditional processing methods such as inversion to zero offset (IZO) are used. To realize the potential of saving acquisition cost by reducing in-fill and to plan resolution improvement by processing, geometry QC methods such as DMO Dip Coverage Spectrum (DDCS) and Bull`s Eyes Analysis are used. The DDCS is a 2-D spectrum whose entries consist of the DMO (Dip Move Out) coverage for a particular reflector specified by it`s true time dip and reflector normal strike. The Bull`s Eyes Analysis relies on real time processing of synthetic data generated with the real geometry. 4 refs., 6 figs.
O'Donnell, David; Sperzel, Johannes; Thibault, Bernard; Rinaldi, Christopher A; Pappone, Carlo; Gutleben, Klaus-Jürgen; Leclercq, Christopher; Razavi, Hedi; Ryu, Kyungmoo; Mcspadden, Luke C; Fischer, Avi; Tomassoni, Gery
2017-04-01
The aim of this study was to evaluate any benefits to the number of viable pacing vectors and maximal spatial coverage with quadripolar left ventricular (LV) leads when compared with tripolar and bipolar equivalents in patients receiving cardiac resynchronization therapy (CRT). A meta-analysis of five previously published clinical trials involving the Quartet™ LV lead (St Jude Medical, St Paul, MN, USA) was performed to evaluate the number of viable pacing vectors defined as capture thresholds ≤2.5 V and no phrenic nerve stimulation and maximal spatial coverage of viable vectors in CRT patients at pre-discharge (n = 370) and first follow-up (n = 355). Bipolar and tripolar lead configurations were modelled by systematic elimination of two and one electrode(s), respectively, from the Quartet lead. The Quartet lead with its four pacing electrodes exhibited the greatest number of pacing vectors per patient when compared with the best bipolar and the best tripolar modelled equivalents. Similarly, the Quartet lead provided the highest spatial coverage in terms of the distance between two furthest viable pacing cathodes when compared with the best bipolar and the best tripolar configurations (P tripolar configurations, elimination of the second proximal electrode (M3) resulted in the highest number of viable pacing options per patient. There were no significant differences observed between pre-discharge and first follow-up analyses. The Quartet lead with its four electrodes and the capability to pace from four anatomical locations provided the highest number of viable pacing vectors at pre-discharge and first follow-up visits, providing more flexibility in device programming and enabling continuation of CRT in more patients when compared with bipolar and tripolar equivalents. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.
Initiation to global Finslerian geometry
Akbar-Zadeh, Hassan
2006-01-01
After a brief description of the evolution of thinking on Finslerian geometry starting from Riemann, Finsler, Berwald and Elie Cartan, the book gives a clear and precise treatment of this geometry. The first three chapters develop the basic notions and methods, introduced by the author, to reach the global problems in Finslerian Geometry. The next five chapters are independent of each other, and deal with among others the geometry of generalized Einstein manifolds, the classification of Finslerian manifolds of constant sectional curvatures. They also give a treatment of isometric, affine, p
Christodorescu, Mihai; Kinder, Johannes; Jha, Somesh; Katzenbeisser, Stefan; Veith, Helmut
2005-01-01
Malware is code designed for a malicious purpose, such as obtaining root privilege on a host. A malware detector identifies malware and thus prevents it from adversely affecting a host. In order to evade detection by malware detectors, malware writers use various obfuscation techniques to transform their malware. There is strong evidence that commercial malware detectors are susceptible to these evasion tactics. In this paper, we describe the design and implementation of a malware normalizer ...
Directory of Open Access Journals (Sweden)
Šárka Nedomová
2013-01-01
Full Text Available Precise quantification of the profile of egg can provide a powerful tool for the analysis of egg shape for various biological problems. A new approach to the geometry of a Ostrich’s egg profile is presented here using an analysing the egg’s digital photo by edge detection techniques. The obtained points on the eggshell counter are fitted by the Fourier series. The obtained equations describing an egg profile have been used to calculate radii of curvature. The radii of the curvature at the important point of the egg profile (sharp end, blunt end and maximum thickness are independent on the egg shape index. The exact values of the egg surface and the egg volume have been obtained. These quantities are also independent on the egg shape index. These quantities can be successively estimated on the basis of simplified equations which are expressed in terms of the egg length, L¸ and its width, B. The surface area of the eggshells also exhibits good correlation with the egg long circumference length. Some limitations of the most used procedures have been also shown.
Nonperturbative quantum geometries
International Nuclear Information System (INIS)
Jacobson, T.; California Univ., Santa Barbara; Smolin, L.; California Univ., Santa Barbara
1988-01-01
Using the self-dual representation of quantum general relativity, based on Ashtekar's new phase space variables, we present an infinite dimensional family of quantum states of the gravitational field which are exactly annihilated by the hamiltonian constraint. These states are constructed from Wilson loops for Ashtekar's connection (which is the spatial part of the left handed spin connection). We propose a new regularization procedure which allows us to evaluate the action of the hamiltonian constraint on these states. Infinite linear combinations of these states which are formally annihilated by the diffeomorphism constraints as well are also described. These are explicit examples of physical states of the gravitational field - and for the compact case are exact zero eigenstates of the hamiltonian of quantum general relativity. Several different approaches to constructing diffeomorphism invariant states in the self dual representation are also described. The physical interpretation of the states described here is discussed. However, as we do not yet know the physical inner product, any interpretation is at this stage speculative. Nevertheless, this work suggests that quantum geometry at Planck scales might be much simpler when explored in terms of the parallel transport of left-handed spinors than when explored in terms of the three metric. (orig.)
Bhatia, Rajendra
2013-01-01
This book is an outcome of the Indo-French Workshop on Matrix Information Geometries (MIG): Applications in Sensor and Cognitive Systems Engineering, which was held in Ecole Polytechnique and Thales Research and Technology Center, Palaiseau, France, in February 23-25, 2011. The workshop was generously funded by the Indo-French Centre for the Promotion of Advanced Research (IFCPAR). During the event, 22 renowned invited french or indian speakers gave lectures on their areas of expertise within the field of matrix analysis or processing. From these talks, a total of 17 original contribution or state-of-the-art chapters have been assembled in this volume. All articles were thoroughly peer-reviewed and improved, according to the suggestions of the international referees. The 17 contributions presented are organized in three parts: (1) State-of-the-art surveys & original matrix theory work, (2) Advanced matrix theory for radar processing, and (3) Matrix-based signal processing applications.
Malinowski, Marcin; Wilton, Penny; Khaghani, Asghar; Brown, Michael; Langholz, David; Hooker, Victoria; Eberhart, Lenora; Hooker, Robert L; Timek, Tomasz A
2016-09-01
Left ventricular assist device (LVAD) implantation may alter right ventricular shape and function and lead to tricuspid regurgitation. This in turn has been reported to be a determinant of right ventricular (RV) failure after LVAD implantation, but the effect of mechanical left ventricular (LV) unloading on the tricuspid annulus is unknown. The aim of the study was to provide insight into the effect of LVAD support on tricuspid annular geometry and dynamics that may help to optimize LV unloading with the least deleterious effect on the right-sided geometry. In seven open-chest anaesthetized sheep, nine sonomicrometry crystals were implanted on the right ventricle. Additional nine crystals were implanted around the tricuspid annulus, with one crystal at each commissure defining three separate annular regions: anterior, posterior and septal. Left ventricular unloading was achieved by connecting a cannula in the left atrium and the aorta to a continuous-flow pump. The pump was used for 15 min at a full flow of 3.8 ± 0.3 l/min. Epicardial echocardiography was used to assess the degree of tricuspid insufficiency. Haemodynamic, echocardiographic and sonomicrometry data were collected before and during full unloading. Tricuspid annular area, and the regional and total perimeter were calculated from crystal coordinates, while 3D annular geometry was expressed as the orthogonal distance of each annular crystal to the least squares plane of all annular crystals. There was no significant tricuspid regurgitation observed either before or during LV unloading. Right ventricular free wall to septum diameter increased significantly at end-diastole during unloading from 23.6 ± 5.8 to 26.3 ± 6.5 mm (P = 0.009), but the right ventricular volume, tricuspid annular area and total perimeter did not change from baseline. However, the septal part of the annulus significantly decreased its maximal length (38.6 ± 8.1 to 37.9 ± 8.2 mm, P = 0.03). Annular contraction was not altered. The
Directory of Open Access Journals (Sweden)
Katja Hueper
Full Text Available To quantify resting myocardial blood flow (MBF in the left ventricular (LV wall of HCM patients and to determine the relationship to important parameters of disease: LV wall thickness, late gadolinium enhancement (LGE, T2-signal abnormalities (dark and bright signal, LV outflow tract obstruction and age.Seventy patients with proven HCM underwent cardiac MRI. Absolute and relative resting MBF were calculated from cardiac perfusion MRI by using the Fermi function model. The relationship between relative MBF and LV wall thickness, T2-signal abnormalities (T2 dark and T2 bright signal, LGE, age and LV outflow gradient as determined by echocardiography was determined using simple and multiple linear regression analysis. Categories of reduced and elevated perfusion in relation to non- or mildly affected reference segments were defined, and T2-signal characteristics and extent as well as pattern of LGE were examined. Statistical testing included linear and logistic regression analysis, unpaired t-test, odds ratios, and Fisher's exact test.804 segments in 70 patients were included in the analysis. In a simple linear regression model LV wall thickness (p<0.001, extent of LGE (p<0.001, presence of edema, defined as focal T2 bright signal (p<0.001, T2 dark signal (p<0.001 and age (p = 0.032 correlated inversely with relative resting MBF. The LV outflow gradient did not show any effect on resting perfusion (p = 0.901. Multiple linear regression analysis revealed that LGE (p<0.001, edema (p = 0.026 and T2 dark signal (p = 0.019 were independent predictors of relative resting MBF. Segments with reduced resting perfusion demonstrated different LGE patterns compared to segments with elevated resting perfusion.In HCM resting MBF is significantly reduced depending on LV wall thickness, extent of LGE, focal T2 signal abnormalities and age. Furthermore, different patterns of perfusion in HCM patients have been defined, which may represent different stages of
International Nuclear Information System (INIS)
Perrow, C.
1989-01-01
The author has chosen numerous concrete examples to illustrate the hazardousness inherent in high-risk technologies. Starting with the TMI reactor accident in 1979, he shows that it is not only the nuclear energy sector that bears the risk of 'normal accidents', but also quite a number of other technologies and industrial sectors, or research fields. The author refers to the petrochemical industry, shipping, air traffic, large dams, mining activities, and genetic engineering, showing that due to the complexity of the systems and their manifold, rapidly interacting processes, accidents happen that cannot be thoroughly calculated, and hence are unavoidable. (orig./HP) [de
GPS: Geometry, Probability, and Statistics
Field, Mike
2012-01-01
It might be said that for most occupations there is now less of a need for mathematics than there was say fifty years ago. But, the author argues, geometry, probability, and statistics constitute essential knowledge for everyone. Maybe not the geometry of Euclid, but certainly geometrical ways of thinking that might enable us to describe the world…
Surrogate Modeling for Geometry Optimization
DEFF Research Database (Denmark)
Rojas Larrazabal, Marielba de la Caridad; Abraham, Yonas; Holzwarth, Natalie
2009-01-01
A new approach for optimizing the nuclear geometry of an atomic system is described. Instead of the original expensive objective function (energy functional), a small number of simpler surrogates is used.......A new approach for optimizing the nuclear geometry of an atomic system is described. Instead of the original expensive objective function (energy functional), a small number of simpler surrogates is used....
Kaehler geometry and SUSY mechanics
International Nuclear Information System (INIS)
Bellucci, Stefano; Nersessian, Armen
2001-01-01
We present two examples of SUSY mechanics related with Kaehler geometry. The first system is the N = 4 supersymmetric one-dimensional sigma-model proposed in hep-th/0101065. Another system is the N = 2 SUSY mechanics whose phase space is the external algebra of an arbitrary Kaehler manifold. The relation of these models with antisymplectic geometry is discussed
A prediction for bubbling geometries
Okuda, Takuya
2007-01-01
We study the supersymmetric circular Wilson loops in N=4 Yang-Mills theory. Their vacuum expectation values are computed in the parameter region that admits smooth bubbling geometry duals. The results are a prediction for the supergravity action evaluated on the bubbling geometries for Wilson loops.
Molecular motion in restricted geometries
Indian Academy of Sciences (India)
Molecular dynamics in restricted geometries is known to exhibit anomalous behaviour. Diffusion, translational or rotational, of molecules is altered significantly on confinement in restricted geometries. Quasielastic neutron scattering (QENS) offers a unique possibility of studying molecular motion in such systems. Both time ...
Ballo, Piercarlo; Nistri, Stefano; Cameli, Matteo; Papesso, Barbara; Dini, Frank Lloyd; Galderisi, Maurizio; Zuppiroli, Alfredo; Mondillo, Sergio
2014-02-01
The relationships of left ventricular (LV) longitudinal and circumferential systolic dysfunction with diastolic performance in hypertensive patients have never been compared. In 532 asymptomatic hypertensive patients, circumferential function was assessed with the use of midwall fractional shortening (mFS) and stress-corrected mFS (SCmFS), whereas longitudinal function was assessed with the use of left atrioventricular plane displacement (AVPD) and systolic mitral annulus velocity (s'). Early diastolic annular velocity (e') and the E/e' ratio were measured. Global longitudinal and circumferential strain were determined in a subset of 210 patients. e' was linearly related to all systolic indexes (AVPD: R = 0.40; s': R = 0.39; mFS: R = 0.16; SCmFS: R = 0.17; all P SCmFS. Longitudinal indexes were superior to circumferential ones in predicting e' <8 cm/s, E/e' <8, and E/e' ≥13. The effect of LV geometry on LV diastolic function was evident among patients with preserved systolic longitudinal function, but was blunted among patients with impaired longitudinal function. In multivariable analyses, only longitudinal indexes remained associated with e' and E/e'. Analyses using strains provided similar results. In asymptomatic hypertensive subjects, LV diastolic performance is independently associated with longitudinal systolic dysfunction, but not with circumferential systolic dysfunction. Subtle longitudinal systolic impairment plays a role in mediating the effect of LV geometry on diastolic performance. These findings may support the need of critically revising the concept of isolated diastolic dysfunction in these patients. Copyright © 2014 Elsevier Inc. All rights reserved.
Shafarevich, Igor Rostislavovich
1994-01-01
Shafarevich Basic Algebraic Geometry 2 The second edition of Shafarevich's introduction to algebraic geometry is in two volumes. The second volume covers schemes and complex manifolds, generalisations in two different directions of the affine and projective varieties that form the material of the first volume. Two notable additions in this second edition are the section on moduli spaces and representable functors, motivated by a discussion of the Hilbert scheme, and the section on Kähler geometry. The book ends with a historical sketch discussing the origins of algebraic geometry. From the Zentralblatt review of this volume: "... one can only respectfully repeat what has been said about the first part of the book (...): a great textbook, written by one of the leading algebraic geometers and teachers himself, has been reworked and updated. As a result the author's standard textbook on algebraic geometry has become even more important and valuable. Students, teachers, and active researchers using methods of al...
Optical geometry across the horizon
International Nuclear Information System (INIS)
Jonsson, Rickard
2006-01-01
In a recent paper (Jonsson and Westman 2006 Class. Quantum Grav. 23 61), a generalization of optical geometry, assuming a non-shearing reference congruence, is discussed. Here we illustrate that this formalism can be applied to (a finite four-volume) of any spherically symmetric spacetime. In particular we apply the formalism, using a non-static reference congruence, to do optical geometry across the horizon of a static black hole. While the resulting geometry in principle is time dependent, we can choose the reference congruence in such a manner that an embedding of the geometry always looks the same. Relative to the embedded geometry the reference points are then moving. We discuss the motion of photons, inertial forces and gyroscope precession in this framework
Energy Technology Data Exchange (ETDEWEB)
Walker, Jonathan R. [Technion-Israel Institute of Technology, Haifa (Israel); Abadi, Sobhi [Rambam Health Care Campus, Medical Imaging Department, Haifa (Israel); Solomonica, Amir [Rambam Health Care Campus, Cardiology Department, Haifa (Israel); Mutlak, Diab; Aronson, Doron; Agmon, Yoram; Lessick, Jonathan [Rambam Health Care Campus, Cardiology Department, Haifa (Israel); Technion-Israel Institute of Technology, Haifa (Israel)
2016-10-15
With increasing use of prospective scanning techniques for cardiac computed tomography (CT), meaningful evaluation of chamber volumes is no longer possible due to lack of normal values. We aimed to define normal values for mid-diastolic (MD) chamber volumes and to determine their significance in comparison to maximum volumes. Normal ranges at MD for left ventricular (LV) volume and mass and left atrial (LA) volume were determined from 101 normal controls. Thereafter, 109 consecutive CT scans, as well as 21 post-myocardial infarction patients, were analysed to determine the relationship between MD and maximum volumes. MD volumes correlated closely with maximal volumes (r = 0.99) for both LV and LA, and could estimate maximum volumes accurately. LV mass, measured at ED or MD, were very similar (r = 0.99). Abnormal MD volumes had excellent sensitivity and specificity to detect chamber enlargement based on maximal volumes (LV 86 %, 100 %, respectively; LA 100 %, 92 %, respectively). A single MD phase can identify patients with cardiomegaly or LV hypertrophy with a high degree of accuracy and MD volumes can give an accurate estimate of maximum LV and LA volumes. circle Traditionally, helical cardiac CT provided clinically important information from chamber volume analysis. (orig.)
DEFF Research Database (Denmark)
Gildberg, Frederik Alkier; Bradley, Stephen K.; Fristed, Peter Billeskov
2012-01-01
Forensic psychiatry is an area of priority for the Danish Government. As the field expands, this calls for increased knowledge about mental health nursing practice, as this is part of the forensic psychiatry treatment offered. However, only sparse research exists in this area. The aim of this study...... was to investigate the characteristics of forensic mental health nursing staff interaction with forensic mental health inpatients and to explore how staff give meaning to these interactions. The project included 32 forensic mental health staff members, with over 307 hours of participant observations, 48 informal....... The intention is to establish a trusting relationship to form behaviour and perceptual-corrective care, which is characterized by staff's endeavours to change, halt, or support the patient's behaviour or perception in relation to staff's perception of normality. The intention is to support and teach the patient...
DEFF Research Database (Denmark)
Madsen, Louise Sofia; Handberg, Charlotte
2018-01-01
implying an influence on whether to participate in cancer survivorship care programs. Because of "pursuing normality," 8 of 9 participants opted out of cancer survivorship care programming due to prospects of "being cured" and perceptions of cancer survivorship care as "a continuation of the disease......BACKGROUND: The present study explored the reflections on cancer survivorship care of lymphoma survivors in active treatment. Lymphoma survivors have survivorship care needs, yet their participation in cancer survivorship care programs is still reported as low. OBJECTIVE: The aim of this study...... was to understand the reflections on cancer survivorship care of lymphoma survivors to aid the future planning of cancer survivorship care and overcome barriers to participation. METHODS: Data were generated in a hematological ward during 4 months of ethnographic fieldwork, including participant observation and 46...
Complex analysis and CR geometry
Zampieri, Giuseppe
2008-01-01
Cauchy-Riemann (CR) geometry is the study of manifolds equipped with a system of CR-type equations. Compared to the early days when the purpose of CR geometry was to supply tools for the analysis of the existence and regularity of solutions to the \\bar\\partial-Neumann problem, it has rapidly acquired a life of its own and has became an important topic in differential geometry and the study of non-linear partial differential equations. A full understanding of modern CR geometry requires knowledge of various topics such as real/complex differential and symplectic geometry, foliation theory, the geometric theory of PDE's, and microlocal analysis. Nowadays, the subject of CR geometry is very rich in results, and the amount of material required to reach competence is daunting to graduate students who wish to learn it. However, the present book does not aim at introducing all the topics of current interest in CR geometry. Instead, an attempt is made to be friendly to the novice by moving, in a fairly relaxed way, f...
The geometry description markup language
International Nuclear Information System (INIS)
Chytracek, R.
2001-01-01
Currently, a lot of effort is being put on designing complex detectors. A number of simulation and reconstruction frameworks and applications have been developed with the aim to make this job easier. A very important role in this activity is played by the geometry description of the detector apparatus layout and its working environment. However, no real common approach to represent geometry data is available and such data can be found in various forms starting from custom semi-structured text files, source code (C/C++/FORTRAN), to XML and database solutions. The XML (Extensible Markup Language) has proven to provide an interesting approach for describing detector geometries, with several different but incompatible XML-based solutions existing. Therefore, interoperability and geometry data exchange among different frameworks is not possible at present. The author introduces a markup language for geometry descriptions. Its aim is to define a common approach for sharing and exchanging of geometry description data. Its requirements and design have been driven by experience and user feedback from existing projects which have their geometry description in XML
Fallow), Stray
2009-01-01
Having trouble with geometry? Do Pi, The Pythagorean Theorem, and angle calculations just make your head spin? Relax. With Head First 2D Geometry, you'll master everything from triangles, quads and polygons to the time-saving secrets of similar and congruent angles -- and it'll be quick, painless, and fun. Through entertaining stories and practical examples from the world around you, this book takes you beyond boring problems. You'll actually use what you learn to make real-life decisions, like using angles and parallel lines to crack a mysterious CSI case. Put geometry to work for you, and
Walsh, Edward T
2014-01-01
This introductory text is designed to help undergraduate students develop a solid foundation in geometry. Early chapters progress slowly, cultivating the necessary understanding and self-confidence for the more rapid development that follows. The extensive treatment can be easily adapted to accommodate shorter courses. Starting with the language of mathematics as expressed in the algebra of logic and sets, the text covers geometric sets of points, separation and angles, triangles, parallel lines, similarity, polygons and area, circles, space geometry, and coordinate geometry. Each chapter incl
Differential geometry curves, surfaces, manifolds
Kohnel, Wolfgang
2002-01-01
This carefully written book is an introduction to the beautiful ideas and results of differential geometry. The first half covers the geometry of curves and surfaces, which provide much of the motivation and intuition for the general theory. Special topics that are explored include Frenet frames, ruled surfaces, minimal surfaces and the Gauss-Bonnet theorem. The second part is an introduction to the geometry of general manifolds, with particular emphasis on connections and curvature. The final two chapters are insightful examinations of the special cases of spaces of constant curvature and Einstein manifolds. The text is illustrated with many figures and examples. The prerequisites are undergraduate analysis and linear algebra.
Definition of treatment geometry in radiation therapy
International Nuclear Information System (INIS)
Aaltonen, P.
1996-01-01
When accurate systems for quality assurance and treatment optimization are employed, a precise system for fixation and dosimetric and portal verification are as important as a continued and standardized code of practice for dosimetry and patient follow-up, including registration of tumour responses and acute and late normal tissue reactions. To improve the accuracy of existing dose response relations in order to improve future therapy the treatment geometry and dose delivery concepts have to be accurately defined and uniformly employed. A Nordic working group was set up in 1991 (by Nordic Association of Clinica Physics) to standardize the concepts and quantities used during the whole radiotherapy process in the Nordic countries. Now the group is finalizing its report ''Specification of Dose Delivery in Radiation Therapy''. The report emphasizes that the treatment geometry shall be consistent with the geometry used during the diagnostic work up. The patient fixation is of importance early in the diagnostic phase to ensure that the same reference points and patients position will be used both during the diagnostic work up, simulation and treatment execution. Reference Coordinate System of the patient is a concept based on defined anatomic reference points. This Patient Reference System is a local system which has validity for the tissues, organs and volumes defined during radiotherapy. The reference points of the Patient Reference System should in turn be used for beam set-up. The treatment geometry is then defined by using different concepts describing tissues which are mobile in the Patient Reference System, and finally, volumes which are fixed in this coordinate system. A Set-up Margin has to be considered for movements of the volumes defined in the Reference Coordinate System of the Patient in relation to the radiation beam. The Set-up Margin is dependent on the treatment technique and it is needed in the treatment planning procedure to ensure that the prescribed
Definition of treatment geometry in radiation therapy
Energy Technology Data Exchange (ETDEWEB)
Aaltonen, P [Finnish Centre for Radiation and Nuclear Safety (STUK), Helsinki (Finland)
1996-08-01
When accurate systems for quality assurance and treatment optimization are employed, a precise system for fixation and dosimetric and portal verification are as important as a continued and standardized code of practice for dosimetry and patient follow-up, including registration of tumour responses and acute and late normal tissue reactions. To improve the accuracy of existing dose response relations in order to improve future therapy the treatment geometry and dose delivery concepts have to be accurately defined and uniformly employed. A Nordic working group was set up in 1991 to standardize the concepts and quantities used during the whole radiotherapy process in the Nordic countries. Now the group is finalizing its report ``Specification of Dose Delivery in Radiation Therapy``. The report emphasizes that the treatment geometry shall be consistent with the geometry used during the diagnostic work up. The patient fixation is of importance early in the diagnostic phase to ensure that the same reference points and patients position will be used both during the diagnostic work up, simulation and treatment execution. Reference Coordinate System of the patient is a concept based on defined anatomic reference points. This Patient Reference System is a local system which has validity for the tissues, organs and volumes defined during radiotherapy. The reference points of the Patient Reference System should in turn be used for beam set-up. The treatment geometry is then defined by using different concepts describing tissues which are mobile in the Patient Reference System, and finally, volumes which are fixed in this coordinate system. A Set-up Margin has to be considered for movements of the volumes defined in the Reference Coordinate System of the Patient in relation to the radiation beam. The Set-up Margin is dependent on the treatment technique and it is needed in the treatment planning procedure to ensure that the prescribed dose to the Target Volume is delivered.
Directory of Open Access Journals (Sweden)
Ane S. Simionato
2017-06-01
Full Text Available One of the most important postharvest plant pathogens that affect strawberries, grapes and tomatoes is Botrytis cinerea, known as gray mold. The fungus remains in latent form until spore germination conditions are good, making infection control difficult, causing great losses in the whole production chain. This study aimed to purify and identify phenazine-1-carboxylic acid (PCA produced by the Pseudomonas aeruginosa LV strain and to determine its antifungal activity against B. cinerea. The compounds produced were extracted with dichloromethane and passed through a chromatographic process. The purity level of PCA was determined by reversed-phase high-performance liquid chromatography semi-preparative. The structure of PCA was confirmed by nuclear magnetic resonance and electrospray ionization mass spectrometry. Antifungal activity was determined by the dry paper disk and minimum inhibitory concentration (MIC methods and identified by scanning electron microscopy and confocal microscopy. The results showed that PCA inhibited mycelial growth, where MIC was 25 μg mL-1. Microscopic analysis revealed a reduction in exopolysaccharide (EPS formation, showing distorted and damaged hyphae of B. cinerea. The results suggested that PCA has a high potential in the control of B. cinerea and inhibition of EPS (important virulence factor. This natural compound is a potential alternative to postharvest control of gray mold disease.
Directory of Open Access Journals (Sweden)
Ajay Kumar
2010-01-01
Full Text Available Dumbbell oligonucleotides with loops of various chemistry were synthesized. Incubation of dumbbell oligonucleotides containing phosphorothioate bonds or trimethylene phosphate linkages in loops with S1 nuclease did not result in significant cleavage under conditions which led to the degradation of dumbbell oligonucleotide containing phophodiester bonds in the loops. The binding of reverse transcriptase of Moloney Murine Leukemia Virus (MoMuLV was evaluated with all the five oligonucleotides. The protein binds to all the dumbbell oligonucleotides with similar affinity. The dissociation constants evaluated using PAGE band mobility shift assays were of the order of 10-7. The inhibitory properties of the retroviral RNase H activity was evaluated using 3H –UTP-labeled RNA:RNA-DNA hybrid. It was found that the best dumbbell oligonucleotide, inhibitor contained phosphorothioate residues in both the loops. Our value studies demonstrated that this particularly designed oligonucleotide displays an IC50 of 18 nM in its inhibition on the reverse transcriptase RNase H activity, a magnitude lower than that of first nucleotide reverse transcriptase of HIV-1, tenofovir, introduced by Gilead Science in the market.
Jing, Fulong; Jiao, Shuhong; Hou, Changbo; Si, Weijian; Wang, Yu
2017-06-21
For targets with complex motion, such as ships fluctuating with oceanic waves and high maneuvering airplanes, azimuth echo signals can be modeled as multicomponent quadratic frequency modulation (QFM) signals after migration compensation and phase adjustment. For the QFM signal model, the chirp rate (CR) and the quadratic chirp rate (QCR) are two important physical quantities, which need to be estimated. For multicomponent QFM signals, the cross terms create a challenge for detection, which needs to be addressed. In this paper, by employing a novel multi-scale parametric symmetric self-correlation function (PSSF) and modified scaled Fourier transform (mSFT), an effective parameter estimation algorithm is proposed-referred to as the Two-Dimensional product modified Lv's distribution (2D-PMLVD)-for QFM signals. The 2D-PMLVD is simple and can be easily implemented by using fast Fourier transform (FFT) and complex multiplication. These measures are analyzed in the paper, including the principle, the cross term, anti-noise performance, and computational complexity. Compared to the other three representative methods, the 2D-PMLVD can achieve better anti-noise performance. The 2D-PMLVD, which is free of searching and has no identifiability problems, is more suitable for multicomponent situations. Through several simulations and analyses, the effectiveness of the proposed estimation algorithm is verified.
Advances in discrete differential geometry
2016-01-01
This is one of the first books on a newly emerging field of discrete differential geometry and an excellent way to access this exciting area. It surveys the fascinating connections between discrete models in differential geometry and complex analysis, integrable systems and applications in computer graphics. The authors take a closer look at discrete models in differential geometry and dynamical systems. Their curves are polygonal, surfaces are made from triangles and quadrilaterals, and time is discrete. Nevertheless, the difference between the corresponding smooth curves, surfaces and classical dynamical systems with continuous time can hardly be seen. This is the paradigm of structure-preserving discretizations. Current advances in this field are stimulated to a large extent by its relevance for computer graphics and mathematical physics. This book is written by specialists working together on a common research project. It is about differential geometry and dynamical systems, smooth and discrete theories, ...
Hyperbolic Metamaterials with Complex Geometry
DEFF Research Database (Denmark)
Lavrinenko, Andrei; Andryieuski, Andrei; Zhukovsky, Sergei
2016-01-01
We investigate new geometries of hyperbolic metamaterialssuch as highly corrugated structures, nanoparticle monolayer assemblies, super-structured or vertically arranged multilayersand nanopillars. All structures retain basic propertiesof hyperbolic metamaterials, but have functionality improved...
An introduction to differential geometry
Willmore, T J
2012-01-01
This text employs vector methods to explore the classical theory of curves and surfaces. Topics include basic theory of tensor algebra, tensor calculus, calculus of differential forms, and elements of Riemannian geometry. 1959 edition.
Symplectic geometry and Fourier analysis
Wallach, Nolan R
2018-01-01
Suitable for graduate students in mathematics, this monograph covers differential and symplectic geometry, homogeneous symplectic manifolds, Fourier analysis, metaplectic representation, quantization, Kirillov theory. Includes Appendix on Quantum Mechanics by Robert Hermann. 1977 edition.
Funabashi, Nobusada; Takaoka, Hiroyuki; Ozawa, Koya; Kamata, Tomoko; Uehara, Masae; Komuro, Issei; Kobayashi, Yoshio
2018-05-30
To achieve further risk stratification in hypertrophic cardiomyopathy (HCM) patients, we localized and quantified layer-specific LVM fibrosis on MRI in HCM patients using regional layer-specific peak longitudinal strain (PLS) and peak circumferential strain (PCS) in LV myocardium (LVM) on speckle tracking transthoracic echocardiography (TTE). A total of 18 HCM patients (14 males; 58 ± 17 years) underwent 1.5T-MRI and TTE. PLS and PCS in each layer of the LVM (endocardium, epicardium, and whole-layer myocardium) were calculated for 17 AHA-defined lesions. MRI assessment showed that fibrosis was classified as endocardial, epicardial, or whole-layer (= either or both of these). Regional PLS was smaller in fibrotic endocardial lesions than in non-fibrotic endocardial lesions (P = 0.004). To detect LV endocardial lesions with fibrosis, ROC curves of regional PLS revealed an area under the curve (AUC) of 0.609 and a best cut-off point of 13.5%, with sensitivity of 65.3% and specificity of 54.3%. Regional PLS was also smaller in fibrotic epicardial lesions than in non-fibrotic epicardial lesions (P layer myocardium analysis, PLS was smaller in fibrotic lesions than in non-fibrotic lesions (P layer LV lesions with fibrosis, ROC curves of regional PLS revealed an AUC of 0.674 and a best cut-off point of 12.5%, with sensitivity of 79.0% and specificity of 50.7%. There were no significant differences in PCS of LV myocardium (endocardium, epicardium, and whole-layer) between fibrotic and non-fibrotic lesions. Quantitative regional PLS but not PCS in LV endocardium, epicardium, and whole-layer myocardium provides useful non-invasive information for layer-specific localization of fibrosis in HCM patients.
Topology and geometry for physicists
Nash, Charles
1983-01-01
Differential geometry and topology are essential tools for many theoretical physicists, particularly in the study of condensed matter physics, gravity, and particle physics. Written by physicists for physics students, this text introduces geometrical and topological methods in theoretical physics and applied mathematics. It assumes no detailed background in topology or geometry, and it emphasizes physical motivations, enabling students to apply the techniques to their physics formulas and research. ""Thoroughly recommended"" by The Physics Bulletin, this volume's physics applications range fr
Spectral dimension of quantum geometries
International Nuclear Information System (INIS)
Calcagni, Gianluca; Oriti, Daniele; Thürigen, Johannes
2014-01-01
The spectral dimension is an indicator of geometry and topology of spacetime and a tool to compare the description of quantum geometry in various approaches to quantum gravity. This is possible because it can be defined not only on smooth geometries but also on discrete (e.g., simplicial) ones. In this paper, we consider the spectral dimension of quantum states of spatial geometry defined on combinatorial complexes endowed with additional algebraic data: the kinematical quantum states of loop quantum gravity (LQG). Preliminarily, the effects of topology and discreteness of classical discrete geometries are studied in a systematic manner. We look for states reproducing the spectral dimension of a classical space in the appropriate regime. We also test the hypothesis that in LQG, as in other approaches, there is a scale dependence of the spectral dimension, which runs from the topological dimension at large scales to a smaller one at short distances. While our results do not give any strong support to this hypothesis, we can however pinpoint when the topological dimension is reproduced by LQG quantum states. Overall, by exploring the interplay of combinatorial, topological and geometrical effects, and by considering various kinds of quantum states such as coherent states and their superpositions, we find that the spectral dimension of discrete quantum geometries is more sensitive to the underlying combinatorial structures than to the details of the additional data associated with them. (paper)
Sherrid, Mark V; Kushner, Josef; Yang, Georgiana; Ro, Richard
2017-04-01
Three competing theories about the mechanism of mitral coaptation in normal subjects were evaluated by color Doppler and vector flow mapping (VFM): (1) beginning of ventricular (LV) ejection, (2) "breaking of the jet" of diastolic LV inflow, and (3) returning diastolic vortices impacting the leaflets on their LV surfaces. We analyzed 80 color Doppler frames and 320 VFM measurements. In all 20 normal subjects, coaptation occurred before LV ejection, 78±16 ms before onset. On color Doppler frames the larger anterior, and smaller posterior vortices circle back and, in all cases, strike the ventricular surfaces of the leaflets. On the first closing-begins frame, for the first time, vortex velocity normal to the ventricular surface of the anterior leaflet (AML) is greater than that in the mitral orifice, and the angle of attack of LV vortical flow onto the AML is twice as high as the angle of flow onto the valve in orifice. Thus, at the moment coaptation begins, vortical flow strikes the mitral leaflet with higher velocity, and higher angle of attack than orifice flow, and thus with greater force. According to the "breaking of the jet" theory, one would expect to see de novo LV flow perpendicular to the leaflets beginning after transmitral flow terminates. Instead, the returning continuous LV vortical flow that impacts the valve builds continuously after the P-wave. Late diastolic vortices strike the ventricular surfaces of the mitral leaflets and contribute to valve coaptation, permitted by concomitant decline in transmitral flow. © 2017, Wiley Periodicals, Inc.
Impact of age and sex on normal left heart structure and function.
Hagström, Linn; Henein, Michael Y; Karp, Kjell; Waldenström, Anders; Lindqvist, Per
2017-11-01
Accurate age- and sex-related normal reference values of ventricular structure and function are important to determine the level of dysfunction in patients. The aim of this study therefore was to document normal age range sex-related measurements of LV structural and functional measurements to serve such purpose. We evaluated left ventricular structure and function in 293 healthy subjects between 20 and 90 years with equally distributed gender. Doppler echocardiography was used including measure of both systolic and diastolic functions. Due to systolic LV function, only long axis function correlated with age (r = 0·55, P<0·01) and the correlation was stronger in females. Concerning diastolic function, there was a strong age correlation in all parameters used (r = 0·40-0·74, P<0·001). Due to LV structural changes over age, females showed a larger reduction in end-diastolic volumes, but no or trivial difference in wall thickness after the age of 60 years. Age is associated with significant normal changes in left ventricular structure and function, which should be considered when deciding on normality. These changes are related to systemic arterial changes as well as body stature, thus reflecting overall body ageing process. Furthermore, normal cardiac ageing in females might partly explain the higher prevalence of heart failure with preserved ejection in females. © 2016 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.
The Geometry Of The Zygapophysial ("Paravertebral") Joints By Biostereometric Measurement
Adams, L. P.; Driver-Jowitt, J. P.
1986-07-01
Precise three dimensional measurements were made on a normal, dried adult vertebral column, using the recently developed reflex microscope. Preliminary conclusions are drawn from these measurements regarding the geometry of the lumbar and thoracic vertebrae. Subsequent measurements were made on a number of unrelated fifth lumbar and first sacral vertebrae and comparisons were made with the findings of the "master model".
Liang, Gao-Feng; Liang, Yan; Xue, Qinggang; Lu, Jin-Feng; Cheng, Jun-Jun; Huang, Jie
2015-03-01
Cytokines play a critical role in innate and adaptive immunity. Astakines represent a group of invertebrate cytokines that are related to vertebrate prokineticin and function in promoting hematopoiesis in crustaceans. We have identified an astakine from the white shrimp Litopeneaus vannamei and named it LvAST in a previous research. In the present research, we investigated the interactions among LvAST, the envelope protein VP37 of white spot syndrome virus (i.e., WSSV), and the β subunit of F1-ATP synthase (ATPsyn-β) of the white shrimp (i.e., BP53) using binding assays and co-precipitations. We also examined the effects of LvAST on shrimp susceptibility to WSSV. We found that LvAST and VP37 competitively bound to BP53, but did not bind to each other. Shrimps that had been injected with recombinant LvAST exhibited significantly lower mortality and longer survival time in experimental infections by WSSV. In contrast, shrimps whose LvAST gene expression had been inhibited by RNA interference showed significantly higher WSSV infection intensity and shorter survival time following viral challenges. These results suggested that LvAST and WSSV both likely use ATPsyn-β as a receptor and LvAST plays a role in shrimp defense against WSSV infection. This represented the first research showing the involvement of astakines in host antiviral immunity. Copyright © 2014 Elsevier Ltd. All rights reserved.
Di Salvo, Giovanni; Gala, Simona; Castaldi, Biagio; Baldini, Luca; Limongelli, Giuseppe; D'Andrea, Antonello; Scognamiglio, Giancarlo; Sarubbi, Berardo; Caso, Pio; Pacileo, Giuseppe; Giovanna Russo, Maria; Calabrò, Raffaele
2011-09-01
To evaluate if obesity has an additional negative impact on left ventricular (LV) geometry and function in normotensive pediatric patients >12 months after successful treatment of aortic coarctation (CoA). We studied 40 CoA patients (mean age 14 ± 3 years, and male sex 70%), of them 10 were obese and 30 lean. Both groups were age and sex comparable. The entire studied sample underwent 24-ambulatory blood pressure (BP) monitoring, standard echocardiographic evaluation, and speckle tracking study. Both office and 24-hour diastolic BP were significantly increased in obese patients. Obese CoA patients showed increased LV mass (52 ± 13 g/m(2.7) vs. 43 ± 9 g/m(2.7) , P = 0.02), and significant reduction in E/A compared with lean CoA patients. Myocardial deformation properties were significantly reduced in obese CoA patients in all the three studied planes (longitudinal, radial, and circumferential) compared with CoA lean patients. LV twist values showed a significant reduction in the obese CoA group (9.9° ± 2.2° vs. 14.5° ± 2.3°, P < 0.0001). Our study shows that obesity in successfully treated CoA children, has an additional negative effect on BP, LV mass, and cardiac function. These findings are of particular concern, since life expectancy in CoA patients is limited mainly by atherosclerosis, and all the obesity-associated abnormalities found are harbingers of higher cardiovascular risk. © 2011, Wiley Periodicals, Inc.
Luo, Qingzhi; Jin, Qi; Zhang, Ning; Han, Yanxin; Wang, Yilong; Huang, Shangwei; Lin, Changjian; Ling, Tianyou; Chen, Kang; Pan, Wenqi; Wu, Liqun
2017-04-13
The objective of this study was to detect differences in the distribution of the left and right ventricle (LV & RV) activation rate (AR) during short-duration ventricular fibrillation (SDVF, 1 min) in normal and heart failure (HF) canine hearts. Ventricular fibrillation (VF) was electrically induced in six healthy dogs (control group) and six dogs with right ventricular pacing-induced congestive HF (HF group). Two 64-electrode basket catheters deployed in the LV and RV were used for global endocardium electrical mapping. The AR of VF was estimated by fast Fourier transform analysis from each electrode. In the control group, the LV was activated faster than the RV in the first 20 s, after which there was no detectable difference in the AR between them. When analyzing the distribution of the AR within the bi-ventricles at 3 min of LDVF, the posterior LV was activated fastest, while the anterior was slowest. In the HF group, a detectable AR gradient existed between the two ventricles within 3 min of VF, with the LV activating more quickly than the RV. When analyzing the distribution of the AR within the bi-ventricles at 3 min of LDVF, the septum of the LV was activated fastest, while the anterior was activated slowest. A global bi-ventricular endocardial AR gradient existed within the first 20 s of VF but disappeared in the LDVF in healthy hearts. However, the AR gradient was always observed in both SDVF and LDVF in HF hearts. The findings of this study suggest that LDVF in HF hearts can be maintained differently from normal hearts, which accordingly should lead to the development of different management strategies for LDVF resuscitation.
Flux compactifications and generalized geometries
International Nuclear Information System (INIS)
Grana, Mariana
2006-01-01
Following the lectures given at CERN Winter School 2006, we present a pedagogical overview of flux compactifications and generalized geometries, concentrating on closed string fluxes in type II theories. We start by reviewing the supersymmetric flux configurations with maximally symmetric four-dimensional spaces. We then discuss the no-go theorems (and their evasion) for compactifications with fluxes. We analyse the resulting four-dimensional effective theories for Calabi-Yau and Calabi-Yau orientifold compactifications, concentrating on the flux-induced superpotentials. We discuss the generic mechanism of moduli stabilization and illustrate with two examples: the conifold in IIB and a T 6 /(Z 3 x Z 3 ) torus in IIA. We finish by studying the effective action and flux vacua for generalized geometries in the context of generalized complex geometry
Flux compactifications and generalized geometries
Energy Technology Data Exchange (ETDEWEB)
Grana, Mariana [Service de Physique Theorique, CEA/Saclay, 91191 Gif-sur-Yvette Cedex (France)
2006-11-07
Following the lectures given at CERN Winter School 2006, we present a pedagogical overview of flux compactifications and generalized geometries, concentrating on closed string fluxes in type II theories. We start by reviewing the supersymmetric flux configurations with maximally symmetric four-dimensional spaces. We then discuss the no-go theorems (and their evasion) for compactifications with fluxes. We analyse the resulting four-dimensional effective theories for Calabi-Yau and Calabi-Yau orientifold compactifications, concentrating on the flux-induced superpotentials. We discuss the generic mechanism of moduli stabilization and illustrate with two examples: the conifold in IIB and a T{sup 6} /(Z{sub 3} x Z{sub 3}) torus in IIA. We finish by studying the effective action and flux vacua for generalized geometries in the context of generalized complex geometry.
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...
Guide to Computational Geometry Processing
DEFF Research Database (Denmark)
Bærentzen, Jakob Andreas; Gravesen, Jens; Anton, François
be processed before it is useful. This Guide to Computational Geometry Processing reviews the algorithms for processing geometric data, with a practical focus on important techniques not covered by traditional courses on computer vision and computer graphics. This is balanced with an introduction...... to the theoretical and mathematical underpinnings of each technique, enabling the reader to not only implement a given method, but also to understand the ideas behind it, its limitations and its advantages. Topics and features: Presents an overview of the underlying mathematical theory, covering vector spaces......, metric space, affine spaces, differential geometry, and finite difference methods for derivatives and differential equations Reviews geometry representations, including polygonal meshes, splines, and subdivision surfaces Examines techniques for computing curvature from polygonal meshes Describes...
Electrodynamics and Spacetime Geometry: Foundations
Cabral, Francisco; Lobo, Francisco S. N.
2017-02-01
We explore the intimate connection between spacetime geometry and electrodynamics. This link is already implicit in the constitutive relations between the field strengths and excitations, which are an essential part of the axiomatic structure of electromagnetism, clearly formulated via integration theory and differential forms. We review the foundations of classical electromagnetism based on charge and magnetic flux conservation, the Lorentz force and the constitutive relations. These relations introduce the conformal part of the metric and allow the study of electrodynamics for specific spacetime geometries. At the foundational level, we discuss the possibility of generalizing the vacuum constitutive relations, by relaxing the fixed conditions of homogeneity and isotropy, and by assuming that the symmetry properties of the electro-vacuum follow the spacetime isometries. The implications of this extension are briefly discussed in the context of the intimate connection between electromagnetism and the geometry (and causal structure) of spacetime.
Dayside merging and cusp geometry
International Nuclear Information System (INIS)
Crooker, N.U.
1979-01-01
Geometrical considerations are presented to show that dayside magnetic merging when constrained to act only where the fields are antiparallel results in lines of merging that converge at the polar cusps. An important consequence of this geometry is that no accelerated flows are predicted across the dayside magnetopause. Acceleration owing to merging acts in opposition to the magnetosheath flow at the merging point and produces the variably directed, slower-than-magnetosheath flows observed in the entry layer. Another consequence of the merging geometry is that much of the time closed field lines constitute the subsolar region of the magnetopause. The manner in which the polar cap convection patterns predicted by the proposed geometry change as the interplanetary field is rotated through 360 0 provides a unifying description of how the observed single circular vortex and the crescent-shaped double vortex patterns mutually evolve under the influence of a single operating principle
DOGBONE GEOMETRY FOR RECIRCULATING ACCELERATORS
International Nuclear Information System (INIS)
BERG, J.S.; JOHNSTONE, C.; SUMMERS, D.
2001-01-01
Most scenarios for accelerating muons require recirculating acceleration. A racetrack shape for the accelerator requires particles with lower energy in early passes to traverse almost the same length of arc as particles with the highest energy. This extra arc length may lead to excess decays and excess cost. Changing the geometry to a dogbone shape, where there is a single linac and the beam turns completely around at the end of the linac, returning to the same end of the linac from which it exited, addresses this problem. In this design, the arc lengths can be proportional to the particle's momentum. This paper proposes an approximate cost model for a recirculating accelerator, attempts to make cost-optimized designs for both racetrack and dogbone geometries, and demonstrates that the dogbone geometry does appear to be more cost effective
Directory of Open Access Journals (Sweden)
Takeshi Tsuda
2017-01-01
Full Text Available Danon disease is a rare X-linked dominant skeletal and cardiac muscle disorder presenting with hypertrophic cardiomyopathy, Wolf-Parkinson-White syndrome, skeletal myopathy, and mild intellectual disability. Early morbidity and mortality due to heart failure or sudden death are known in Danon disease, more in males than in females. Here, we present a 17-year-old female adolescent with Danon disease and severe concentric hypertrophy with normal left ventricular (LV systolic function, who has been complaining of intermittent headache and weakness for about 3 years, initially diagnosed with hemiplegic migraine. Subsequently, her neurological manifestation progressed to transient ischemic attack (TIA and eventually to ischemic stroke confirmed by CT scan with 1-day history of expressive aphasia followed by persistent left side weakness and numbness. Detailed echocardiogram for the first time revealed a small LV apical thrombus with unchanged severe biventricular hypertrophy and normal systolic function. This unexpected LV apical thrombus may be associated with a wide spectrum of neurological deficits ranging from TIA to ischemic stroke in Danon disease. Possibility of cerebral ischemic events should be suspected in Danon disease when presenting with neurological deficits even with normal systolic function. Careful assessment for LV apical thrombus is warranted in such cases.
Geometric Transformations in Engineering Geometry
Directory of Open Access Journals (Sweden)
I. F. Borovikov
2015-01-01
Full Text Available Recently, for business purposes, in view of current trends and world experience in training engineers, research and faculty staff there has been a need to transform traditional courses of descriptive geometry into the course of engineering geometry in which the geometrical transformations have to become its main section. On the basis of critical analysis the paper gives suggestions to improve a presentation technique of this section both in the classroom and in academic literature, extend an application scope of geometrical transformations to solve the position and metric tasks and simulation of surfaces, as well as to design complex engineering configurations, which meet a number of pre-specified conditions.The article offers to make a number of considerable amendments to the terms and definitions used in the existing courses of descriptive geometry. It draws some conclusions and makes the appropriate proposals on feasibility of coordination in teaching the movement transformation in the courses of analytical and descriptive geometry. This will provide interdisciplinary team teaching and allow students to be convinced that a combination of analytical and graphic ways to solve geometric tasks is useful and reasonable.The traditional sections of learning courses need to be added with a theory of projective and bi-rational transformations. In terms of application simplicity and convenience it is enough to consider the central transformations when solving the applied tasks. These transformations contain a beam of sub-invariant (low-invariant straight lines on which the invariant curve induces non-involution and involution projectivities. The expediency of nonlinear transformations application is shown in the article by a specific example of geometric modeling of the interfacing surface "spar-blade".Implementation of these suggestions will contribute to a real transformation of a traditional course of descriptive geometry to the engineering geometry
KEMAJUAN BELAJAR SISWA PADA GEOMETRI TRANSFORMASI MENGGUNAKAN AKTIVITAS REFLEKSI GEOMETRI
Directory of Open Access Journals (Sweden)
Irkham Ulil Albab
2014-10-01
Full Text Available Abstrak: Penelitian ini bertujuan untuk mendeskripsikan kemajuan belajar siswa pada materi geometri transformasi yang didukung dengan serangkaian aktivitas belajar berdasarkan Pendidikan Matematika Realistik Indonesia. Penelitian didesain melalui tiga tahap, yaitu tahapan perancangan desain awal, pengujian desain melalui pembelajaran awal dan pembelajaran eksperimental, dan tahap analisis retrospektif. Dalam penelitian ini, Hypothetical Learning Trajectory, HLT (HLT berperan penting sebagai desain pembelajaran sekaligus instrumen penelitian. HLT diujikan terhadap 26 siswa kelas VII. Data dikumpulkan dengan teknik wawancara, pengamatan, dan catatan lapangan. Hasil penelitian menunjukkan bahwa desain pembelajaran ini mampu menstimulasi siswa untuk memberikan karakteristik refleksi dan transformasi geometri lainnya secara informal, mengklasifikasikannya dalam transformasi isometri pada level kedua, dan menemukan garis bantuan refleksi pada level yang lebih formal. Selain itu, garis bantuan refleksi digunakan oleh siswa untuk menggambar bayangan refleksi dan pola pencerminan serta memahami bentuk rotasi dan translasi sebagai kombinasi refleksi adalah level tertinggi. Keyword: transformasi geometri, kombinasi refleksi, rotasi, translasi, design research, HLT STUDENTS’ LEARNING PROGRESS ON TRANSFORMATION GEOMETRY USING THE GEOMETRY REFLECTION ACTIVITIES Abstract: This study was aimed at describing the students’ learning progress on transformation geometry supported by a set of learning activities based on Indonesian Realistic Mathematics Education. The study was designed into three stages, that is, the preliminary design stage, the design testing through initial instruction and experiment, and the restrospective analysis stage. In this study, Hypothetical Learning Trajectory (HLT played an important role as an instructional design and a research instrument. HLT was tested to 26 seventh grade students. The data were collected through interviews
Graphical debugging of combinational geometry
International Nuclear Information System (INIS)
Burns, T.J.; Smith, M.S.
1992-01-01
A graphical debugger for combinatorial geometry being developed at Oak Ridge National Laboratory is described. The prototype debugger consists of two parts: a FORTRAN-based ''view'' generator and a Microsoft Windows application for displaying the geometry. Options and features of both modules are discussed. Examples illustrating the various options available are presented. The potential for utilizing the images produced using the debugger as a visualization tool for the output of the radiation transport codes is discussed as is the future direction of the development
Lectures on Algebraic Geometry I
Harder, Gunter
2012-01-01
This book and the following second volume is an introduction into modern algebraic geometry. In the first volume the methods of homological algebra, theory of sheaves, and sheaf cohomology are developed. These methods are indispensable for modern algebraic geometry, but they are also fundamental for other branches of mathematics and of great interest in their own. In the last chapter of volume I these concepts are applied to the theory of compact Riemann surfaces. In this chapter the author makes clear how influential the ideas of Abel, Riemann and Jacobi were and that many of the modern metho
Combinatorial geometry in the plane
Hadwiger, Hugo; Klee, Victor
2014-01-01
Geared toward advanced undergraduates familiar with analysis and college geometry, this concise book discusses theorems on topics restricted to the plane such as convexity, coverings, and graphs. In addition to helping students cultivate rigorous thought, the text encourages the development of mathematical intuition and clarifies the nature of mathematical research.The two-part treatment begins with specific topics including integral distances, covering problems, point set geometry and convexity, simple paradoxes involving point sets, and pure combinatorics, among other subjects. The second pa
Modern differential geometry for physicists
Isham, C J
1989-01-01
These notes are the content of an introductory course on modern, coordinate-free differential geometry which is taken by the first-year theoretical physics PhD students, or by students attending the one-year MSc course "Fundamental Fields and Forces" at Imperial College. The book is concerned entirely with mathematics proper, although the emphasis and detailed topics have been chosen with an eye to the way in which differential geometry is applied these days to modern theoretical physics. This includes not only the traditional area of general relativity but also the theory of Yang-Mills fields
Comparison theorems in Riemannian geometry
Cheeger, Jeff
2008-01-01
The central theme of this book is the interaction between the curvature of a complete Riemannian manifold and its topology and global geometry. The first five chapters are preparatory in nature. They begin with a very concise introduction to Riemannian geometry, followed by an exposition of Toponogov's theorem-the first such treatment in a book in English. Next comes a detailed presentation of homogeneous spaces in which the main goal is to find formulas for their curvature. A quick chapter of Morse theory is followed by one on the injectivity radius. Chapters 6-9 deal with many of the most re
Geometry, topology, and string theory
Energy Technology Data Exchange (ETDEWEB)
Varadarajan, Uday [Univ. of California, Berkeley, CA (United States)
2003-01-01
A variety of scenarios are considered which shed light upon the uses and limitations of classical geometric and topological notions in string theory. The primary focus is on situations in which D-brane or string probes of a given classical space-time see the geometry quite differently than one might naively expect. In particular, situations in which extra dimensions, non-commutative geometries as well as other non-local structures emerge are explored in detail. Further, a preliminary exploration of such issues in Lorentzian space-times with non-trivial causal structures within string theory is initiated.
Spatial geometry and special relativity
DEFF Research Database (Denmark)
Kneubil, Fabiana Botelho
2016-01-01
In this work, it is shown the interplay of relative and absolute entities, which are present in both spatial geometry and special relativity. In order to strengthen the understanding of special relativity, we discuss firstly an instance of geometry and the existence of both frame......-dependent and frame-independent entities. We depart from a subject well known by students, which is the three-dimensional geometric space in order to compare, afterwards, with the treatment of four-dimensional space in the special relativity. The differences and similarities between these two subjects are also...
Stochastic geometry and its applications
Chiu, Sung Nok; Kendall, Wilfrid S; Mecke, Joseph
2013-01-01
An extensive update to a classic text Stochastic geometry and spatial statistics play a fundamental role in many modern branches of physics, materials sciences, engineering, biology and environmental sciences. They offer successful models for the description of random two- and three-dimensional micro and macro structures and statistical methods for their analysis. The previous edition of this book has served as the key reference in its field for over 18 years and is regarded as the best treatment of the subject of stochastic geometry, both as a subject with vital a
Introduction to topology and geometry
Stahl, Saul
2014-01-01
An easily accessible introduction to over three centuries of innovations in geometry Praise for the First Edition ". . . a welcome alternative to compartmentalized treatments bound to the old thinking. This clearly written, well-illustrated book supplies sufficient background to be self-contained." -CHOICE This fully revised new edition offers the most comprehensive coverage of modern geometry currently available at an introductory level. The book strikes a welcome balance between academic rigor and accessibility, providing a complete and cohesive picture of the science with an unparallele
Algebraic geometry and theta functions
Coble, Arthur B
1929-01-01
This book is the result of extending and deepening all questions from algebraic geometry that are connected to the central problem of this book: the determination of the tritangent planes of a space curve of order six and genus four, which the author treated in his Colloquium Lecture in 1928 at Amherst. The first two chapters recall fundamental ideas of algebraic geometry and theta functions in such fashion as will be most helpful in later applications. In order to clearly present the state of the central problem, the author first presents the better-known cases of genus two (Chapter III) and
Geometry, topology, and string theory
International Nuclear Information System (INIS)
Varadarajan, Uday
2003-01-01
A variety of scenarios are considered which shed light upon the uses and limitations of classical geometric and topological notions in string theory. The primary focus is on situations in which D-brane or string probes of a given classical space-time see the geometry quite differently than one might naively expect. In particular, situations in which extra dimensions, non-commutative geometries as well as other non-local structures emerge are explored in detail. Further, a preliminary exploration of such issues in Lorentzian space-times with non-trivial causal structures within string theory is initiated
DEFF Research Database (Denmark)
Hindsø, Louise; Fuchs, Andreas; Kühl, Jørgen Tobias
2017-01-01
regional normal reference values of the left ventricle. The aim of this study was to derive reference values of regional LV myocardial thickness (LVMT) and mass (LVMM) from a healthy study group of the general population using cardiac computed tomography angiography (CCTA). We wanted to introduce LV...... myocardial distribution (LVMD) as a measure of regional variation of the LVMT. Moreover, we wanted to determine whether these parameters varied between men and women. We studied 568 (181 men; 32%) adults, free of cardiovascular disease and risk factors, who underwent 320-detector CCTA. Mean age was 55 (range...... 40-84) years. Regional LVMT and LVMM were measured, according to the American Heart Association's 17 segment model, using semi-automatic software. Mean LVMT were 6.6 mm for men and 5.4 mm for women (p normal LV was thickest in the basal septum (segment 3; men = 8.3 mm; women = 7.2 mm...
Bai, Rong; Pu, Jun; Liu, Nian; Lu, Jia-Gao; Zhou, Qiang; Ruan, Yan-Fei; Niu, Hui-Yan; Wang, Lin
2003-12-25
In order to verify the hypothesis that left ventricular epicardial (LV-Epi) pacing and biventricular (BiV) pacing unavoidably influence the myocardial electrophysiological characters and may result in high risk of malignant ventricular arrhythmia, we calculated, in both normal mongrel dogs and dog models with rapid-right-ventricular-pacing induced dilated cardiomyopathy congestive heart failure (DCM-CHF), the monophasic action potential duration (MAPD) and the transmural dispersion of repolarization (TDR) in intracardiac electrogram together with the QT interval and T(peak)-T(end) (T(p(-T(e)) interval in surface electrocardiogram (ECG) during LV-Epi and BiV pacing, compared with those during right ventricular endocardial (RV-Endo) pacing. To prepare the DCM-CHF dog model, rapid right ventricular pacing (250 bpm) was performed for 23.6+/-2.57 days to the dog. All the normal and DCM-CHF dogs were given radio frequency catheter ablation (RFCA) to His bundle with the guide of X-ray fluoroscopy. After the RFCA procedures, the animals were under the situation of complete atrioventricular block so that the canine heart rates could be voluntarily controlled in the following experiments. After a thoracotomy, ECG and monophasic action potentials (MAP) of subendocardial, subepicardial and mid-layer myocardium were recorded synchronously in 8 normal and 5 DCM-CHF dogs during pacing from endocardium of RV apex (RV-Endo), epicardium of LV anterior wall (LV-Epi) and simultaneously both of the above (biventricular, BiV), the later was similar to the ventricular resynchronization therapy to congestive heart failure patients in clinic. The Tp-Te) meant the interval from the peak to the end of T wave, which was a representative index of TDR in surface ECG. The TDR was defined as the difference between the longest and the shortest MAPD of subendocardial, subepicardial and mid-layer myocardium. Our results showed that in normal dogs, pacing participating of LV (LV-Epi, BiV) prolonged
Differential geometry the mathematical works of J. H. C. Whitehead
James, I M
1962-01-01
The Mathematical Works of J. H. C. Whitehead, Volume 1: Differential Geometry contains all of Whitehead's published work on differential geometry, along with some papers on algebras. Most of these were written in the period 1929-1937, but a few later articles are included. The book begins with a list of Whitehead's works, in chronological order of writing as well as a biographical note by M. H. A. Newman and Barbara Whitehead, and a mathematical appreciation by John Milnor. This is followed by separate chapters on topics such as linear connections; a method of obtaining normal representations
The Idea of Order at Geometry Class.
Rishel, Thomas
The idea of order in geometry is explored using the experience of assignments given to undergraduates in a college geometry course "From Space to Geometry." Discussed are the definition of geometry, and earth measurement using architecture, art, and common experience. This discussion concludes with a consideration of the question of whether…
Teaching Spatial Geometry in a Virtual World
DEFF Research Database (Denmark)
Förster, Klaus-Tycho
2017-01-01
Spatial geometry is one of the fundamental mathematical building blocks of any engineering education. However, it is overshadowed by planar geometry in the curriculum between playful early primary education and later analytical geometry, leaving a multi-year gap where spatial geometry is absent...
Mochizuki, Hiroyuki; Takahashi, Masashi; Nishigaki, Kazuo; Ide, Tetsuya; Goto-Koshino, Yuko; Watanabe, Shinya; Sato, Hirofumi; Sato, Masahiko; Kotera, Yukiko; Fujino, Yasuhito; Ohno, Koichi; Uchida, Kazuyuki; Tsujimoto, Hajime
2011-04-15
We established a novel feline B-cell line, MS4, from the neoplastic pleural effusion of a cat with cutaneous B-cell lymphoma. Immunophenotype staining of the MS4 cells was positive for CD20, CD79α, and IgA and negative for CD3, CD4, CD5, CD8α, CD18, CD21, CD22, IgM, IgG, Ig light chain, and MHC class II. PCR analysis for immunoglobulin heavy chain gene rearrangements revealed a monoclonal rearrangement, whereas no clonal rearrangement of the T-cell receptor γ gene was detected. Southern blotting with an exogenous feline leukemia virus (FeLV) U3 probe revealed no integration of exogenous FeLV provirus. The MS4 cell line is the first FeLV-negative feline B-cell lymphoma cell line, and may be used to investigate the pathogenesis of spontaneously occurring feline lymphoma and the development of new therapies. Copyright © 2011 Elsevier B.V. All rights reserved.
Analogical Reasoning in Geometry Education
Magdas, Ioana
2015-01-01
The analogical reasoning isn't used only in mathematics but also in everyday life. In this article we approach the analogical reasoning in Geometry Education. The novelty of this article is a classification of geometrical analogies by reasoning type and their exemplification. Our classification includes: analogies for understanding and setting a…
Exploring Bundling Theory with Geometry
Eckalbar, John C.
2006-01-01
The author shows how instructors might successfully introduce students in principles and intermediate microeconomic theory classes to the topic of bundling (i.e., the selling of two or more goods as a package, rather than separately). It is surprising how much students can learn using only the tools of high school geometry. To be specific, one can…
Stochastic Modelling of River Geometry
DEFF Research Database (Denmark)
Sørensen, John Dalsgaard; Schaarup-Jensen, K.
1996-01-01
Numerical hydrodynamic river models are used in a large number of applications to estimate critical events for rivers. These estimates are subject to a number of uncertainties. In this paper, the problem to evaluate these estimates using probabilistic methods is considered. Stochastic models for ...... for river geometries are formulated and a coupling between hydraulic computational methods and numerical reliability methods is presented....
Matter in toy dynamical geometries
Konopka, T.J.
2009-01-01
One of the objectives of theories describing quantum dynamical geometry is to compute expectation values of geometrical observables. The results of such computations can be affected by whether or not matter is taken into account. It is thus important to understand to what extent and to what effect
Ca??adas, Mar??a C.; Molina, Marta; Gallardo, Sandra; Mart??nez-Santaolalla, Manuel J.; Pe??as, Mar??a
2010-01-01
In this work we present an activity for High School students in which various mathematical concepts of plane and spatial geometry are involved. The final objective of the proposed tasks is constructing a particular polyhedron, the cube, by using a modality of origami called modular origami.
Granular flows in constrained geometries
Murthy, Tejas; Viswanathan, Koushik
Confined geometries are widespread in granular processing applications. The deformation and flow fields in such a geometry, with non-trivial boundary conditions, determine the resultant mechanical properties of the material (local porosity, density, residual stresses etc.). We present experimental studies of deformation and plastic flow of a prototypical granular medium in different nontrivial geometries- flat-punch compression, Couette-shear flow and a rigid body sliding past a granular half-space. These geometries represent simplified scaled-down versions of common industrial configurations such as compaction and dredging. The corresponding granular flows show a rich variety of flow features, representing the entire gamut of material types, from elastic solids (beam buckling) to fluids (vortex-formation, boundary layers) and even plastically deforming metals (dead material zone, pile-up). The effect of changing particle-level properties (e.g., shape, size, density) on the observed flows is also explicitly demonstrated. Non-smooth contact dynamics particle simulations are shown to reproduce some of the observed flow features quantitatively. These results showcase some central challenges facing continuum-scale constitutive theories for dynamic granular flows.
General Relativity: Geometry Meets Physics
Thomsen, Dietrick E.
1975-01-01
Observing the relationship of general relativity and the geometry of space-time, the author questions whether the rest of physics has geometrical explanations. As a partial answer he discusses current research on subatomic particles employing geometric transformations, and cites the existence of geometrical definitions of physical quantities such…
Learners engaging with transformation geometry
African Journals Online (AJOL)
participants engaged in investigative semi-structured interviews with the resear- chers. ... Keywords: analysis; conversions; transformation geometry; transformations; treatments .... semiotic systems of representation is not only to designate mathematical objects or to com- municate but also to ... Research design. We believe ...
Multivariable calculus and differential geometry
Walschap, Gerard
2015-01-01
This text is a modern in-depth study of the subject that includes all the material needed from linear algebra. It then goes on to investigate topics in differential geometry, such as manifolds in Euclidean space, curvature, and the generalization of the fundamental theorem of calculus known as Stokes' theorem.
College geometry a unified development
Kay, David C
2011-01-01
""The book is a comprehensive textbook on basic geometry. … Key features of the book include numerous figures and many problems, more than half of which come with hints or even complete solutions. Frequent historical comments add to making the reading a pleasant one.""-Michael Joswig, Zentralblatt MATH 1273
Vertex Normals and Face Curvatures of Triangle Meshes
Sun, Xiang; Jiang, Caigui; Wallner, Johannes; Pottmann, Helmut
2016-01-01
This study contributes to the discrete differential geometry of triangle meshes, in combination with discrete line congruences associated with such meshes. In particular we discuss when a congruence defined by linear interpolation of vertex normals
Prospects of inflation with perturbed throat geometry
International Nuclear Information System (INIS)
Ali, Amna; Chingangbam, R.; Panda, Sudhakar; Sami, M.
2009-01-01
We study brane inflation in a warped deformed conifold background that includes general possible corrections to the throat geometry sourced by coupling to the bulk of a compact Calabi-Yau space. We focus specifically, on the perturbation by chiral operator of dimension 3/2 in the CFT. We find that the effective potential in this case can give rise to required number of e-foldings and the spectral index n S consistent with observation. The tensor to scalar ratio of perturbations is generally very low in this scenario. The COBE normalization, however, poses certain difficulties which can be circumvented provided model parameters are properly fine tuned. We find the numerical values of parameters which can give rise to enough inflation, observationally consistent values of density perturbations, scalar to tensor ratio of perturbations and the spectral index n S .
Mahaffey, Michael L.
One of a series of experimental units for children at the preschool level, this booklet deals with geometric concepts. A unit on volume and a unit on linear measurement are covered; for each unit a discussion of mathematical objectives, a list of materials needed, and a sequence of learning activities are provided. Directions are specified for the…
DEFF Research Database (Denmark)
Byg din egen boomerang, kast den, se den flyve, forstå hvorfor og hvordan den vender tilbage, og grib den. Det handler om opdriften på vingerne når du flyver, men det handler også og allermest om den mærkværdige gyroskop-effekt, du bruger til at holde balancen, når du kører på cykel. Vi vil bruge...
Discrete differential geometry. Consistency as integrability
Bobenko, Alexander I.; Suris, Yuri B.
2005-01-01
A new field of discrete differential geometry is presently emerging on the border between differential and discrete geometry. Whereas classical differential geometry investigates smooth geometric shapes (such as surfaces), and discrete geometry studies geometric shapes with finite number of elements (such as polyhedra), the discrete differential geometry aims at the development of discrete equivalents of notions and methods of smooth surface theory. Current interest in this field derives not ...
Numerically robust geometry engine for compound solid geometries
International Nuclear Information System (INIS)
Vlachoudis, V.; Sinuela-Pastor, D.
2013-01-01
Monte Carlo programs heavily rely on a fast and numerically robust solid geometry engines. However the success of solid modeling, depends on facilities for specifying and editing parameterized models through a user-friendly graphical front-end. Such a user interface has to be fast enough in order to be interactive for 2D and/or 3D displays, but at the same time numerically robust in order to display possible modeling errors at real time that could be critical for the simulation. The graphical user interface Flair for FLUKA currently employs such an engine where special emphasis has been given on being fast and numerically robust. The numerically robustness is achieved by a novel method of estimating the floating precision of the operations, which dynamically adapts all the decision operations accordingly. Moreover a predictive caching mechanism is ensuring that logical errors in the geometry description are found online, without compromising the processing time by checking all regions. (authors)
Lim, Sooyeon; Rhee, Moon-Soo; Chang, Dong-Ho; Kim, Byoung-Chan
2016-04-10
Erysipelothrix larvae LV19(T) was preliminary isolated from the larval gut of a rhinoceros beetle, Trypoxylus dichotomus in Korea. Here, we present the whole genome sequence of E. larvae LV19(T) strain, which consisted of 2,511,486 base pairs with a GC content of 37.4% and one plasmid. Unlike other Erysipelothrix strains (SY 1027, Fujisawa and ATCC 19414), the arsenic-resistance genes were identified in LV19(T) strain. Copyright © 2016 Elsevier B.V. All rights reserved.
Code subspaces for LLM geometries
Berenstein, David; Miller, Alexandra
2018-03-01
We consider effective field theory around classical background geometries with a gauge theory dual, specifically those in the class of LLM geometries. These are dual to half-BPS states of N= 4 SYM. We find that the language of code subspaces is natural for discussing the set of nearby states, which are built by acting with effective fields on these backgrounds. This work extends our previous work by going beyond the strict infinite N limit. We further discuss how one can extract the topology of the state beyond N→∞ and find that, as before, uncertainty and entanglement entropy calculations provide a useful tool to do so. Finally, we discuss obstructions to writing down a globally defined metric operator. We find that the answer depends on the choice of reference state that one starts with. Therefore, within this setup, there is ambiguity in trying to write an operator that describes the metric globally.
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.
Fractal geometry and computer graphics
Sakas, Georgios; Peitgen, Heinz-Otto; Englert, Gabriele
1992-01-01
Fractal geometry has become popular in the last 15 years, its applications can be found in technology, science, or even arts. Fractal methods and formalism are seen today as a general, abstract, but nevertheless practical instrument for the description of nature in a wide sense. But it was Computer Graphics which made possible the increasing popularity of fractals several years ago, and long after their mathematical formulation. The two disciplines are tightly linked. The book contains the scientificcontributions presented in an international workshop in the "Computer Graphics Center" in Darmstadt, Germany. The target of the workshop was to present the wide spectrum of interrelationships and interactions between Fractal Geometry and Computer Graphics. The topics vary from fundamentals and new theoretical results to various applications and systems development. All contributions are original, unpublished papers.The presentations have been discussed in two working groups; the discussion results, together with a...
The geometry of celestial mechanics
Geiges, Hansjörg
2016-01-01
Celestial mechanics is the branch of mathematical astronomy devoted to studying the motions of celestial bodies subject to the Newtonian law of gravitation. This mathematical introductory textbook reveals that even the most basic question in celestial mechanics, the Kepler problem, leads to a cornucopia of geometric concepts: conformal and projective transformations, spherical and hyperbolic geometry, notions of curvature, and the topology of geodesic flows. For advanced undergraduate and beginning graduate students, this book explores the geometric concepts underlying celestial mechanics and is an ideal companion for introductory courses. The focus on the history of geometric ideas makes it perfect supplementary reading for students in elementary geometry and topology. Numerous exercises, historical notes and an extensive bibliography provide all the contextual information required to gain a solid grounding in celestial mechanics.
Differential geometry and mathematical physics
Rudolph, Gerd
Starting from an undergraduate level, this book systematically develops the basics of • Calculus on manifolds, vector bundles, vector fields and differential forms, • Lie groups and Lie group actions, • Linear symplectic algebra and symplectic geometry, • Hamiltonian systems, symmetries and reduction, integrable systems and Hamilton-Jacobi theory. The topics listed under the first item are relevant for virtually all areas of mathematical physics. The second and third items constitute the link between abstract calculus and the theory of Hamiltonian systems. The last item provides an introduction to various aspects of this theory, including Morse families, the Maslov class and caustics. The book guides the reader from elementary differential geometry to advanced topics in the theory of Hamiltonian systems with the aim of making current research literature accessible. The style is that of a mathematical textbook,with full proofs given in the text or as exercises. The material is illustrated by numerous d...
Grassmannian geometry of scattering amplitudes
Arkani-Hamed, Nima; Cachazo, Freddy; Goncharov, Alexander; Postnikov, Alexander; Trnka, Jaroslav
2016-01-01
Outlining a revolutionary reformulation of the foundations of perturbative quantum field theory, this book is a self-contained and authoritative analysis of the application of this new formulation to the case of planar, maximally supersymmetric Yang–Mills theory. The book begins by deriving connections between scattering amplitudes and Grassmannian geometry from first principles before introducing novel physical and mathematical ideas in a systematic manner accessible to both physicists and mathematicians. The principle players in this process are on-shell functions which are closely related to certain sub-strata of Grassmannian manifolds called positroids - in terms of which the classification of on-shell functions and their relations becomes combinatorially manifest. This is an essential introduction to the geometry and combinatorics of the positroid stratification of the Grassmannian and an ideal text for advanced students and researchers working in the areas of field theory, high energy physics, and the...
Foliation theory in algebraic geometry
McKernan, James; Pereira, Jorge
2016-01-01
Featuring a blend of original research papers and comprehensive surveys from an international team of leading researchers in the thriving fields of foliation theory, holomorphic foliations, and birational geometry, this book presents the proceedings of the conference "Foliation Theory in Algebraic Geometry," hosted by the Simons Foundation in New York City in September 2013. Topics covered include: Fano and del Pezzo foliations; the cone theorem and rank one foliations; the structure of symmetric differentials on a smooth complex surface and a local structure theorem for closed symmetric differentials of rank two; an overview of lifting symmetric differentials from varieties with canonical singularities and the applications to the classification of AT bundles on singular varieties; an overview of the powerful theory of the variety of minimal rational tangents introduced by Hwang and Mok; recent examples of varieties which are hyperbolic and yet the Green-Griffiths locus is the whole of X; and a classificati...
Groups and Geometries : Siena Conference
Kantor, William; Lunardon, Guglielmo; Pasini, Antonio; Tamburini, Maria
1998-01-01
On September 1-7, 1996 a conference on Groups and Geometries took place in lovely Siena, Italy. It brought together experts and interested mathematicians from numerous countries. The scientific program centered around invited exposi tory lectures; there also were shorter research announcements, including talks by younger researchers. The conference concerned a broad range of topics in group theory and geometry, with emphasis on recent results and open problems. Special attention was drawn to the interplay between group-theoretic methods and geometric and combinatorial ones. Expanded versions of many of the talks appear in these Proceedings. This volume is intended to provide a stimulating collection of themes for a broad range of algebraists and geometers. Among those themes, represented within the conference or these Proceedings, are aspects of the following: 1. the classification of finite simple groups, 2. the structure and properties of groups of Lie type over finite and algebraically closed fields of f...
Needle decompositions in Riemannian geometry
Klartag, Bo'az
2017-01-01
The localization technique from convex geometry is generalized to the setting of Riemannian manifolds whose Ricci curvature is bounded from below. In a nutshell, the author's method is based on the following observation: When the Ricci curvature is non-negative, log-concave measures are obtained when conditioning the Riemannian volume measure with respect to a geodesic foliation that is orthogonal to the level sets of a Lipschitz function. The Monge mass transfer problem plays an important role in the author's analysis.
Systematics of IIB spinorial geometry
Gran, U.; Gutowski, J.; Papadopoulos, G.; Roest, D.
2005-01-01
We reduce the classification of all supersymmetric backgrounds of IIB supergravity to the evaluation of the Killing spinor equations and their integrability conditions, which contain the field equations, on five types of spinors. This extends the work of [hep-th/0503046] to IIB supergravity. We give the expressions of the Killing spinor equations on all five types of spinors. In this way, the Killing spinor equations become a linear system for the fluxes, geometry and spacetime derivatives of...
Geometry Dependence of Stellarator Turbulence
International Nuclear Information System (INIS)
Mynick, H.E.; Xanthopoulos, P.; Boozer, A.H.
2009-01-01
Using the nonlinear gyrokinetic code package GENE/GIST, we study the turbulent transport in a broad family of stellarator designs, to understand the geometry-dependence of the microturbulence. By using a set of flux tubes on a given flux surface, we construct a picture of the 2D structure of the microturbulence over that surface, and relate this to relevant geometric quantities, such as the curvature, local shear, and effective potential in the Schrodinger-like equation governing linear drift modes
Superbanana orbits in stellarator geometries
International Nuclear Information System (INIS)
Derr, J.A.; Shohet, J.L.
1979-04-01
The presence of superbanana orbit types localized to either the interior or the exterior of stellarators and torsatrons is numerically investigated for 3.5 MeV alpha particles. The absence of the interior superbanana in both geometries is found to be due to non-conservation of the action. Exterior superbananas are found in the stellarator only, as a consequence of the existence of closed helical magnetic wells. No superbananas of either type are found in the torsatron
Turtle geometry the Python way
Battle, S.
2014-01-01
An introduction to coding using Python’s on-screen ‘turtle’ that can be commanded with a few simple instructions including forward, backward, left and right. The turtle leaves a trace that can be used to draw geometric figures. This workshop is aimed at beginners of all ages. The aim is to learn a smattering of programming and a little bit of geometry in a fun way.
Topics in modern differential geometry
Verstraelen, Leopold
2017-01-01
A variety of introductory articles is provided on a wide range of topics, including variational problems on curves and surfaces with anisotropic curvature. Experts in the fields of Riemannian, Lorentzian and contact geometry present state-of-the-art reviews of their topics. The contributions are written on a graduate level and contain extended bibliographies. The ten chapters are the result of various doctoral courses which were held in 2009 and 2010 at universities in Leuven, Serbia, Romania and Spain.
Computational geometry for reactor applications
International Nuclear Information System (INIS)
Brown, F.B.; Bischoff, F.G.
1988-01-01
Monte Carlo codes for simulating particle transport involve three basic computational sections: a geometry package for locating particles and computing distances to regional boundaries, a physics package for analyzing interactions between particles and problem materials, and an editing package for determining event statistics and overall results. This paper describes the computational geometry methods in RACER, a vectorized Monte Carlo code used for reactor physics analysis, so that comparisons may be made with techniques used in other codes. The principal applications for RACER are eigenvalue calculations and power distributions associated with reactor core physics analysis. Successive batches of neutrons are run until convergence and acceptable confidence intervals are obtained, with typical problems involving >10 6 histories. As such, the development of computational geometry methods has emphasized two basic needs: a flexible but compact geometric representation that permits accurate modeling of reactor core details and efficient geometric computation to permit very large numbers of histories to be run. The current geometric capabilities meet these needs effectively, supporting a variety of very large and demanding applications
Number theory III Diophantine geometry
1991-01-01
From the reviews of the first printing of this book, published as Volume 60 of the Encyclopaedia of Mathematical Sciences: "Between number theory and geometry there have been several stimulating influences, and this book records of these enterprises. This author, who has been at the centre of such research for many years, is one of the best guides a reader can hope for. The book is full of beautiful results, open questions, stimulating conjectures and suggestions where to look for future developments. This volume bears witness of the broad scope of knowledge of the author, and the influence of several people who have commented on the manuscript before publication ... Although in the series of number theory, this volume is on diophantine geometry, and the reader will notice that algebraic geometry is present in every chapter. ... The style of the book is clear. Ideas are well explained, and the author helps the reader to pass by several technicalities. Reading and rereading this book I noticed that the topics ...
Riemannian geometry and geometric analysis
Jost, Jürgen
2017-01-01
This established reference work continues to provide its readers with a gateway to some of the most interesting developments in contemporary geometry. It offers insight into a wide range of topics, including fundamental concepts of Riemannian geometry, such as geodesics, connections and curvature; the basic models and tools of geometric analysis, such as harmonic functions, forms, mappings, eigenvalues, the Dirac operator and the heat flow method; as well as the most important variational principles of theoretical physics, such as Yang-Mills, Ginzburg-Landau or the nonlinear sigma model of quantum field theory. The present volume connects all these topics in a systematic geometric framework. At the same time, it equips the reader with the working tools of the field and enables her or him to delve into geometric research. The 7th edition has been systematically reorganized and updated. Almost no page has been left unchanged. It also includes new material, for instance on symplectic geometry, as well as the B...
Donaldson invariants in algebraic geometry
International Nuclear Information System (INIS)
Goettsche, L.
2000-01-01
In these lectures I want to give an introduction to the relation of Donaldson invariants with algebraic geometry: Donaldson invariants are differentiable invariants of smooth compact 4-manifolds X, defined via moduli spaces of anti-self-dual connections. If X is an algebraic surface, then these moduli spaces can for a suitable choice of the metric be identified with moduli spaces of stable vector bundles on X. This can be used to compute Donaldson invariants via methods of algebraic geometry and has led to a lot of activity on moduli spaces of vector bundles and coherent sheaves on algebraic surfaces. We will first recall the definition of the Donaldson invariants via gauge theory. Then we will show the relation between moduli spaces of anti-self-dual connections and moduli spaces of vector bundles on algebraic surfaces, and how this makes it possible to compute Donaldson invariants via algebraic geometry methods. Finally we concentrate on the case that the number b + of positive eigenvalues of the intersection form on the second homology of the 4-manifold is 1. In this case the Donaldson invariants depend on the metric (or in the algebraic geometric case on the polarization) via a system of walls and chambers. We will study the change of the invariants under wall-crossing, and use this in particular to compute the Donaldson invariants of rational algebraic surfaces. (author)
Aspects of differential geometry II
Gilkey, Peter
2015-01-01
Differential Geometry is a wide field. We have chosen to concentrate upon certain aspects that are appropriate for an introduction to the subject; we have not attempted an encyclopedic treatment. Book II deals with more advanced material than Book I and is aimed at the graduate level. Chapter 4 deals with additional topics in Riemannian geometry. Properties of real analytic curves given by a single ODE and of surfaces given by a pair of ODEs are studied, and the volume of geodesic balls is treated. An introduction to both holomorphic and Kähler geometry is given. In Chapter 5, the basic properties of de Rham cohomology are discussed, the Hodge Decomposition Theorem, Poincaré duality, and the Künneth formula are proved, and a brief introduction to the theory of characteristic classes is given. In Chapter 6, Lie groups and Lie algebras are dealt with. The exponential map, the classical groups, and geodesics in the context of a bi-invariant metric are discussed. The de Rham cohomology of compact Lie groups an...
Normal Pressure Hydrocephalus (NPH)
... local chapter Join our online community Normal Pressure Hydrocephalus (NPH) Normal pressure hydrocephalus is a brain disorder ... Symptoms Diagnosis Causes & risks Treatments About Normal Pressure Hydrocephalus Normal pressure hydrocephalus occurs when excess cerebrospinal fluid ...
Energy Technology Data Exchange (ETDEWEB)
Ziada, G.; Abdel-Dayem, H.M.; Higazy, E.; Mohamed, M.M.; Bahar, R.; Hayat, N.; Yousof, A.M.
1987-03-01
A dual gated tomography (DGT) program for end systolic and end diastolic acquisition and subsequent processing for calculation of LVEF, end diastolic and end systolic volumes (EDV, ESV) has been evaluated in 20 healthy volunteers (25 years-40 years) and 45 patients (25 years-60 years): 20 with ischaemic heart disease and 25 with valvular heart disease (VHD). All had biplane multigated blood pool (MUGA) studies in the 40/sup 0/ LAO projection using in vivo /sup 99m/Tc-R BCs, immediately followed by DG. The results in the patients group were correlated with contrast ventriculography (CV). In the volunteer group, the normal values for LVEF, EDV and ESV measured with DGT were found to be 63%+10%, 91 ml + 6 ml and 30 ml + 6ml and r value for the LVEF=0.91 compared with MUGA. In the IHD group, r values compared with CV were 0.915 and 0.97 for the EDV and ESV and 0.934 for the LVEF. Compared with the MUGA, the r value for LVEF was 0.883. In the VHD group, r values were 0.98 for both the EDV and ESV and 0.948 for the LVEF (P<0.002) compared with CV and 0.789 for the LVEF compared with the MUGA. We feel that DGT is an accurate and reproducible technique for LV function measurements.
Kosmala, Wojciech; Jedrzejuk, Diana; Derzhko, Roksolana; Przewlocka-Kosmala, Monika; Mysiak, Andrzej; Bednarek-Tupikowska, Grazyna
2012-05-01
Obesity predisposes to left ventricular (LV) dysfunction and heart failure; however, the risk of these complications has not been assessed in patients with a normal body mass index (BMI) but increased body fat content (normal-weight obesity, NWO). We hypothesized that LV performance in NWO may be impaired and sought to investigate potential contributors to cardiac functional abnormalities. One hundred sixty-eight subjects (age, 38±7 years) with BMI affecting the myocardium were classified on the basis of body fat content into 2 groups: with NWO and without NWO. Echocardiographic indices of LV systolic and diastolic function, including myocardial velocities and deformation, serological fibrosis markers, indicators of proinflammatory activation, and metabolic control, were evaluated. Subjects with NWO demonstrated impaired LV systolic and diastolic function, increased fibrosis intensity (assessed by procollagen type I carboxy-terminal propeptide [PICP]), impaired insulin sensitivity, and increased proinflammatory activation as compared with individuals with normal body fat. The independent correlates of LV systolic and diastolic function variables were as follows: for strain, IL-18 (β=-0.17, P<0.006), C-reactive protein (β=-0.20, P<0.002) and abdominal fat deposit (β=-0.20, P<0.003); for tissue S velocity, PICP (β=-0.21, P<0.002) and abdominal fat deposit (β=-0.43, P<0.0001); for tissue E velocity, abdominal fat deposit (β=-0.30, P<0.0001), PICP (β=-0.31, P<0.0001) and homeostasis model assessment of insulin resistance index (HOMA IR; β=-0.20, P<0.002); and for E/e'-PICP, IL-18 (both β=0.18, P<0.01) and HOMA IR (β=0.16, P<0.04). In patients with NWO, subclinical disturbances of LV function are independently associated with the extent of abdominal fat deposit, profibrotic state (as reflected by circulating PICP), reduced insulin sensitivity, and proinflammatory activation.
Algebraic Geometry and Number Theory Summer School
Sarıoğlu, Celal; Soulé, Christophe; Zeytin, Ayberk
2017-01-01
This lecture notes volume presents significant contributions from the “Algebraic Geometry and Number Theory” Summer School, held at Galatasaray University, Istanbul, June 2-13, 2014. It addresses subjects ranging from Arakelov geometry and Iwasawa theory to classical projective geometry, birational geometry and equivariant cohomology. Its main aim is to introduce these contemporary research topics to graduate students who plan to specialize in the area of algebraic geometry and/or number theory. All contributions combine main concepts and techniques with motivating examples and illustrative problems for the covered subjects. Naturally, the book will also be of interest to researchers working in algebraic geometry, number theory and related fields.
Geometry success in 20 minutes a day
LLC, LearningExpress
2014-01-01
Whether you're new to geometry or just looking for a refresher, Geometry Success in 20 Minutes a Day offers a 20-step lesson plan that provides quick and thorough instruction in practical, critical skills. Stripped of unnecessary math jargon but bursting with geometry essentials, Geometry Success in 20 Minutes a Day: Covers all vital geometry skills, from the basic building blocks of geometry to ratio, proportion, and similarity to trigonometry and beyond Provides hundreds of practice exercises in test format Applies geometr
Network geometry with flavor: From complexity to quantum geometry
Bianconi, Ginestra; Rahmede, Christoph
2016-03-01
Network geometry is attracting increasing attention because it has a wide range of applications, ranging from data mining to routing protocols in the Internet. At the same time advances in the understanding of the geometrical properties of networks are essential for further progress in quantum gravity. In network geometry, simplicial complexes describing the interaction between two or more nodes play a special role. In fact these structures can be used to discretize a geometrical d -dimensional space, and for this reason they have already been widely used in quantum gravity. Here we introduce the network geometry with flavor s =-1 ,0 ,1 (NGF) describing simplicial complexes defined in arbitrary dimension d and evolving by a nonequilibrium dynamics. The NGF can generate discrete geometries of different natures, ranging from chains and higher-dimensional manifolds to scale-free networks with small-world properties, scale-free degree distribution, and nontrivial community structure. The NGF admits as limiting cases both the Bianconi-Barabási models for complex networks, the stochastic Apollonian network, and the recently introduced model for complex quantum network manifolds. The thermodynamic properties of NGF reveal that NGF obeys a generalized area law opening a new scenario for formulating its coarse-grained limit. The structure of NGF is strongly dependent on the dimensionality d . In d =1 NGFs grow complex networks for which the preferential attachment mechanism is necessary in order to obtain a scale-free degree distribution. Instead, for NGF with dimension d >1 it is not necessary to have an explicit preferential attachment rule to generate scale-free topologies. We also show that NGF admits a quantum mechanical description in terms of associated quantum network states. Quantum network states evolve by a Markovian dynamics and a quantum network state at time t encodes all possible NGF evolutions up to time t . Interestingly the NGF remains fully classical but
Echocardiographic evaluation of mitral geometry in functional mitral regurgitation
Directory of Open Access Journals (Sweden)
Maleki Majid
2008-10-01
Full Text Available Abstract Objectives We sought to evaluate the geometric changes of the mitral leaflets, local and global LV remodeling in patients with left ventricular dysfunction and varying degrees of Functional mitral regurgitation (FMR. Background Functional mitral regurgitation (FMR occurs as a consequence of systolic left ventricular (LV dysfunction caused by ischemic or nonischemic cardiomyopathy. Mitral valve repair in ischemic MR is one of the most controversial topic in surgery and proper repairing requires an understanding of its mechanisms, as the exact mechanism of FMR are not well defined. Methods 136 consecutive patients mean age of 55 with systolic LV dysfunction and FMR underwent complete echocardiography and after assessing MR severity, LV volumes, Ejection Fraction, LV sphericity index, C-Septal distance, Mitral valve annulus, Interpapillary distance, Tenting distance and Tenting area were obtained. Results There was significant association between MR severity and echocardiogarphic indices (all p values Mitral annular dimensions and area, C-septal distance and sphericity index, although greater in patients with severe regurgitation, did not significantly contribute to FMR severity. Conclusion Degree of LV enlargement and dysfunction were not primary determinants of FMR severity, therefore local LV remodeling and mitral valve apparatus deformation are the strongest predictors of functional MR severity.
Carter-Storch, Rasmus; Møller, Jacob E; Christensen, Nicolaj L; Irmukhadenov, Akhmadjon; Rasmussen, Lars M; Pecini, Redi; Øvrehus, Kristian A; Søndergård, Eva V; Marcussen, Niels; Dahl, Jordi S
2017-12-01
Severe aortic stenosis (AS) most often presents with reduced aortic valve area (gradient (≥40 mm Hg; normal-flow high-gradient AS) or low mean gradient (normal-flow low-gradient [NFLG] AS). The benefit of aortic valve replacement (AVR) among NFLG patients is controversial. We compared the impact of NFLG condition on preoperative left ventricular (LV) remodeling and myocardial fibrosis and postoperative remodeling and symptomatic benefit. Eighty-seven consecutive patients with reduced aortic valve area and normal stroke volume index undergoing AVR underwent echocardiography, magnetic resonance imaging, a 6-minute walk test, and measurement of natriuretic peptides before and 1 year after AVR. Myocardial fibrosis was assessed from magnetic resonance imaging. Patients were stratified as NFLG or normal-flow high-gradient. In total, 33 patients (38%) had NFLG. Before AVR, they were characterized by similar symptom burden but less severe AS measured by aortic valve area index (0.50±0.09 versus 0.40±0.08 cm 2 /m 2 ; P gradient condition independently predicted change in LV mass index. Patients with NFLG had less severe AS and LV remodeling than patients with normal-flow high-gradient. Furthermore, NFLG patients experienced less reverse remodeling but the same symptomatic benefit. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02316587. © 2017 American Heart Association, Inc.
Ju, Jia-Fei; Hoffmann, Ary A; Zhang, Yan-Kai; Duan, Xing-Zhi; Guo, Yan; Gong, Jun-Tao; Zhu, Wen-Chao; Hong, Xiao-Yue
2017-06-01
Wolbachia are endosymbionts that infect many species of arthropods and nematodes. Wolbachia-induced cytoplasmic incompatibility (CI) is the most common phenotype in affected hosts, involving embryonic lethality in crosses between Wolbachia-infected males and uninfected females. The molecular mechanisms underlying this phenomenon are currently unclear. Here we examine the molecular correlates of the Wolbachia infection in Laodelphax striatellus (Fallén), an important rice pest, where embryonic lethality is strong and almost complete. We compared the gene expression of 4-day-old Wolbachia-infected and uninfected L. striatellus testes to identify candidate genes for paternal-effect embryonic lethality induction. Based on microarray analysis, iLvE was the most down-regulated gene; this gene mediates branched-chain amino acid (BCAA) biosynthesis and participates in many processes related to reproductive performance. After knocking down iLvE by RNAi in uninfected male L. striatellus, male fertility was reduced, leading to a decrease in embryo hatching rates, but fertility was rescued in crosses between these males and Wolbachia-infected females. Removal of BCAA in chemically-defined diets of uninfected males also led to a loss of male fertility. Low amino acid nutrition may enhance exposure time of sperm to Wolbachia in the testes to affect adult reproduction in L. striatellus by reducing the number of sperm transferred per mating by males. These results indicate that Wolbachia may decrease male fertility in L. striatellus by acting on iLvE, a key factor of BCAA biosynthesis, and delaying sperm maturation. Copyright © 2017 Elsevier Ltd. All rights reserved.
A Whirlwind Tour of Computational Geometry.
Graham, Ron; Yao, Frances
1990-01-01
Described is computational geometry which used concepts and results from classical geometry, topology, combinatorics, as well as standard algorithmic techniques such as sorting and searching, graph manipulations, and linear programing. Also included are special techniques and paradigms. (KR)
Optimizing solar-cell grid geometry
Crossley, A. P.
1969-01-01
Trade-off analysis and mathematical expressions calculate optimum grid geometry in terms of various cell parameters. Determination of the grid geometry provides proper balance between grid resistance and cell output to optimize the energy conversion process.
M. Larson; D. Bendz; G. Göransson
2013-01-01
The turbidity variation in time and space is investigated in the downstream stretch of the river Göta Älv in Sweden. The river is heavily regulated and carries the discharge from the largest fresh water lake in Sweden, Lake Vänern, to the outflow point in Göteborg Harbour on the Swedish west coast. The river is an important waterway and serves as a fresh-water supply for 700 000 users. Turbidity is utilised as a water quality indicator to ensure sufficient quality of the intake water to the t...
Directory of Open Access Journals (Sweden)
Lee Gyu-sub
2016-01-01
Full Text Available The exhaustion of fossil fuel and the greenhouse gas emission are one of the most significant energy and environmental issues, respectively. Photovoltaic (PV generators and battery energy storage systems (BESSs have been significantly increased for recent years. The BESSs are mainly used for smoothing active power fluctuation of the PV. In this paper, PV–BESSs integration of two DC/DC converters and one AC/DC converter is investigated and DC-link voltage control to compensate the AC voltage deviation is proposed for the PV‒BESS system in low-voltage (LV networks.
Classification of digital affine noncommutative geometries
Majid, Shahn; Pachoł, Anna
2018-03-01
It is known that connected translation invariant n-dimensional noncommutative differentials dxi on the algebra k[x1, …, xn] of polynomials in n-variables over a field k are classified by commutative algebras V on the vector space spanned by the coordinates. These data also apply to construct differentials on the Heisenberg algebra "spacetime" with relations [xμ, xν] = λΘμν, where Θ is an antisymmetric matrix, as well as to Lie algebras with pre-Lie algebra structures. We specialise the general theory to the field k =F2 of two elements, in which case translation invariant metrics (i.e., with constant coefficients) are equivalent to making V a Frobenius algebra. We classify all of these and their quantum Levi-Civita bimodule connections for n = 2, 3, with partial results for n = 4. For n = 2, we find 3 inequivalent differential structures admitting 1, 2, and 3 invariant metrics, respectively. For n = 3, we find 6 differential structures admitting 0, 1, 2, 3, 4, 7 invariant metrics, respectively. We give some examples for n = 4 and general n. Surprisingly, not all our geometries for n ≥ 2 have zero quantum Riemann curvature. Quantum gravity is normally seen as a weighted "sum" over all possible metrics but our results are a step towards a deeper approach in which we must also "sum" over differential structures. Over F2 we construct some of our algebras and associated structures by digital gates, opening up the possibility of "digital geometry."
Normalization: A Preprocessing Stage
Patro, S. Gopal Krishna; Sahu, Kishore Kumar
2015-01-01
As we know that the normalization is a pre-processing stage of any type problem statement. Especially normalization takes important role in the field of soft computing, cloud computing etc. for manipulation of data like scale down or scale up the range of data before it becomes used for further stage. There are so many normalization techniques are there namely Min-Max normalization, Z-score normalization and Decimal scaling normalization. So by referring these normalization techniques we are ...
Stochastic geometry for image analysis
Descombes, Xavier
2013-01-01
This book develops the stochastic geometry framework for image analysis purpose. Two main frameworks are described: marked point process and random closed sets models. We derive the main issues for defining an appropriate model. The algorithms for sampling and optimizing the models as well as for estimating parameters are reviewed. Numerous applications, covering remote sensing images, biological and medical imaging, are detailed. This book provides all the necessary tools for developing an image analysis application based on modern stochastic modeling.
Magnetoelectrostatic thruster physical geometry tests
Ramsey, W. D.
1981-01-01
Inert gas tests are conducted with several magnetoelectrostatic containment discharge chamber geometries. The configurations tested include three discharge chamber lengths; three boundary magnet patterns; two different flux density magnet materials; hemispherical and conical shaped thrusters having different surface-to-volume ratios; and two and three grid ion optics. Argon mass utilizations of 60 to 79% are attained at 210 to 280 eV/ion in different test configurations. Short hemi thruster configurations are found to produce 70 to 92% xenon mass utilization at 185 to 220 eV/ion.
Programming system for analytic geometry
International Nuclear Information System (INIS)
Raymond, Jacques
1970-01-01
After having outlined the characteristics of computing centres which do not comply with engineering tasks, notably the time required by all different tasks to be performed when developing a software (assembly, compilation, link edition, loading, run), and identified constraints specific to engineering, the author identifies the characteristics a programming system should have to suit engineering tasks. He discussed existing conversational systems and their programming language, and their main drawbacks. Then, he presents a system which aims at facilitating programming and addressing problems of analytic geometry and trigonometry
The geometry of special relativity
International Nuclear Information System (INIS)
Parizet, Jean
2008-01-01
This book for students in mathematics or physics shows the interest of geometry to understand special relativity as a consequence of invariance of Maxwell equations and of constancy of the speed of light. Space-time is actually provided with a geometrical structure and a physical interpretation: at each observer are associated his own time and his own physical space in which occur events he is concerned with. This leads to a natural approach to special relativity. The Lorentz group and its algebra are then studied by using matrices and the Pauli algebra. Quaternions are also addressed
Moduli spaces in algebraic geometry
International Nuclear Information System (INIS)
Goettsche, L.
2000-01-01
This volume of the new series of lecture notes of the Abdus Salam International Centre for Theoretical Physics contains the lecture notes of the School on Algebraic Geometry which took place at the Abdus Salam International Centre for Theoretical Physics from 26 July to 13 August 1999. The school consisted of 2 weeks of lecture courses and one week of conference. The topic of the school was moduli spaces. More specifically the lectures were divided into three subtopics: principal bundles on Riemann surfaces, moduli spaces of vector bundles and sheaves on projective varieties, and moduli spaces of curves
Worldsheet geometries of ambitwistor string
Energy Technology Data Exchange (ETDEWEB)
Ohmori, Kantaro [Department of Physics, the University of Tokyo,Hongo, Bunkyo-ku, Tokyo 133-0022 (Japan)
2015-06-12
Mason and Skinner proposed the ambitwistor string theory which directly reproduces the formulas for the amplitudes of massless particles proposed by Cachazo, He and Yuan. In this paper we discuss geometries of the moduli space of worldsheets associated to the bosonic or the RNS ambitwistor string. Further, we investigate the factorization properties of the amplitudes when an internal momentum is near on-shell in the abstract CFT language. Along the way, we propose the existence of the ambitwistor strings with three or four fermionic worldsheet currents.
Porous media geometry and transports
Adler, Pierre
1992-01-01
The goal of ""Porous Media: Geometry and Transports"" is to provide the basis of a rational and modern approach to porous media. This book emphasizes several geometrical structures (spatially periodic, fractal, and random to reconstructed) and the three major single-phase transports (diffusion, convection, and Taylor dispersion).""Porous Media"" serves various purposes. For students it introduces basic information on structure and transports. Engineers will find this book useful as a readily accessible assemblage of al the major experimental results pertaining to single-phase tr
Geometry of physical dispersion relations
International Nuclear Information System (INIS)
Raetzel, Dennis; Rivera, Sergio; Schuller, Frederic P.
2011-01-01
To serve as a dispersion relation, a cotangent bundle function must satisfy three simple algebraic properties. These conditions are derived from the inescapable physical requirements that local matter field dynamics must be predictive and allow for an observer-independent notion of positive energy. Possible modifications of the standard relativistic dispersion relation are thereby severely restricted. For instance, the dispersion relations associated with popular deformations of Maxwell theory by Gambini-Pullin or Myers-Pospelov are not admissible. Dispersion relations passing the simple algebraic checks derived here correspond to physically admissible Finslerian refinements of Lorentzian geometry.
Projective geometry and projective metrics
Busemann, Herbert
2005-01-01
The basic results and methods of projective and non-Euclidean geometry are indispensable for the geometer, and this book--different in content, methods, and point of view from traditional texts--attempts to emphasize that fact. Results of special theorems are discussed in detail only when they are needed to develop a feeling for the subject or when they illustrate a general method. On the other hand, an unusual amount of space is devoted to the discussion of the fundamental concepts of distance, motion, area, and perpendicularity.Topics include the projective plane, polarities and conic sectio
Tropical geometry of statistical models.
Pachter, Lior; Sturmfels, Bernd
2004-11-16
This article presents a unified mathematical framework for inference in graphical models, building on the observation that graphical models are algebraic varieties. From this geometric viewpoint, observations generated from a model are coordinates of a point in the variety, and the sum-product algorithm is an efficient tool for evaluating specific coordinates. Here, we address the question of how the solutions to various inference problems depend on the model parameters. The proposed answer is expressed in terms of tropical algebraic geometry. The Newton polytope of a statistical model plays a key role. Our results are applied to the hidden Markov model and the general Markov model on a binary tree.
Geometry of supersymmetric gauge theories
International Nuclear Information System (INIS)
Gieres, F.
1988-01-01
This monograph gives a detailed and pedagogical account of the geometry of rigid superspace and supersymmetric Yang-Mills theories. While the core of the text is concerned with the classical theory, the quantization and anomaly problem are briefly discussed following a comprehensive introduction to BRS differential algebras and their field theoretical applications. Among the treated topics are invariant forms and vector fields on superspace, the matrix-representation of the super-Poincare group, invariant connections on reductive homogeneous spaces and the supermetric approach. Various aspects of the subject are discussed for the first time in textbook and are consistently presented in a unified geometric formalism
Clustering in Hilbert simplex geometry
Nielsen, Frank
2017-04-03
Clustering categorical distributions in the probability simplex is a fundamental primitive often met in applications dealing with histograms or mixtures of multinomials. Traditionally, the differential-geometric structure of the probability simplex has been used either by (i) setting the Riemannian metric tensor to the Fisher information matrix of the categorical distributions, or (ii) defining the information-geometric structure induced by a smooth dissimilarity measure, called a divergence. In this paper, we introduce a novel computationally-friendly non-Riemannian framework for modeling the probability simplex: Hilbert simplex geometry. We discuss the pros and cons of those three statistical modelings, and compare them experimentally for clustering tasks.
An invitation to noncommutative geometry
Marcolli, Matilde
2008-01-01
This is the first existing volume that collects lectures on this important and fast developing subject in mathematics. The lectures are given by leading experts in the field and the range of topics is kept as broad as possible by including both the algebraic and the differential aspects of noncommutative geometry as well as recent applications to theoretical physics and number theory. Sample Chapter(s). A Walk in the Noncommutative Garden (1,639 KB). Contents: A Walk in the Noncommutative Garden (A Connes & M Marcolli); Renormalization of Noncommutative Quantum Field Theory (H Grosse & R Wulke
Trends and developments in computational geometry
Berg, de M.
1997-01-01
This paper discusses some trends and achievements in computational geometry during the past five years, with emphasis on problems related to computer graphics. Furthermore, a direction of research in computational geometry is discussed that could help in bringing the fields of computational geometry
Global affine differential geometry of hypersurfaces
Li, An-Min; Zhao, Guosong; Hu, Zejun
2015-01-01
This book draws a colorful and widespread picture of global affine hypersurface theory up to the most recent state. Moreover, the recent development revealed that affine differential geometry- as differential geometry in general- has an exciting intersection area with other fields of interest, like partial differential equations, global analysis, convex geometry and Riemann surfaces.
"WGL," a Web Laboratory for Geometry
Quaresma, Pedro; Santos, Vanda; Maric, Milena
2018-01-01
The role of information and communication technologies (ICT) in education is nowadays well recognised. The "Web Geometry Laboratory," is an e-learning, collaborative and adaptive, Web environment for geometry, integrating a well known dynamic geometry system. In a collaborative session, teachers and students, engaged in solving…
Chiral anomalies and differential geometry
International Nuclear Information System (INIS)
Zumino, B.
1983-10-01
Some properties of chiral anomalies are described from a geometric point of view. Topics include chiral anomalies and differential forms, transformation properties of the anomalies, identification and use of the anomalies, and normalization of the anomalies. 22 references
International Nuclear Information System (INIS)
Naito, H.; Arisawa, J.; Harada, K.; Yamagami, H.; Kozuka, T.; Tamura, S.
1996-01-01
Purpose: To identify the normal performance of left ventricular (LV) regional contraction using cine MR imaging with presaturation myocardial tagging. Material and Methods: Sixteen normal volunteers were examined on a 1.5 T MR system with tagging cine sequences. Tags were applied at end-diastole as 2 parallel black lines on short-axis and 4-chamber sections, and the fractional shortenings were calculated at 7 LV locations. Results: The following results were obtained with significance: A transmural gradient of contractility in the short-axis section; prolonged late-systolic endocardial shortening and epicardial early termination in the free wall; initial delay of shortening in the anterior wall; apical predominance of contractility; predominance of circumferential shortening in the free wall and of meridional shortening in the septum. These findings could be associated with myocardial fiber architecture, presumed wall stress and temporal asynergy of excitation. Conclusion: Cine MR imaging with myocardial tagging proved to be useful in assessing the nonuniformity of LV contraction. (orig.)
Computational geometry algorithms and applications
de Berg, Mark; Overmars, Mark; Schwarzkopf, Otfried
1997-01-01
Computational geometry emerged from the field of algorithms design and anal ysis in the late 1970s. It has grown into a recognized discipline with its own journals, conferences, and a large community of active researchers. The suc cess of the field as a research discipline can on the one hand be explained from the beauty of the problems studied and the solutions obtained, and, on the other hand, by the many application domains--computer graphics, geographic in formation systems (GIS), robotics, and others-in which geometric algorithms play a fundamental role. For many geometric problems the early algorithmic solutions were either slow or difficult to understand and implement. In recent years a number of new algorithmic techniques have been developed that improved and simplified many of the previous approaches. In this textbook we have tried to make these modem algorithmic solutions accessible to a large audience. The book has been written as a textbook for a course in computational geometry, but it can ...
Tearing modes in toroidal geometry
International Nuclear Information System (INIS)
Connor, J.W.; Cowley, S.C.; Hastie, R.J.; Hender, T.C.; Hood, A.; Martin, T.J.
1988-01-01
The separation of the cylindrical tearing mode stability problem into a resistive resonant layer calculation and an external marginal ideal magnetohydrodynamic (MHD) calculation (Δ' calculation) is generalized to axisymmetric toroidal geometry. The general structure of this separation is analyzed and the marginal ideal MHD information (the toroidal generalization of Δ') required to discuss stability is isolated. This can then, in principle, be combined with relevant resonant layer calculations to determine tearing mode growth rates in realistic situations. Two examples are given: the first is an analytic treatment of toroidally coupled (m = 1, n = 1) and (m = 2, n = 1) tearing modes in a large aspect ratio torus; the second, a numerical treatment of the toroidal coupling of three tearing modes through finite pressure effects in a large aspect ratio torus. In addition, the use of a coupling integral approach for determining the stability of coupled tearing modes is discussed. Finally, the possibility of using initial value resistive MHD codes in realistic toroidal geometry to determine the necessary information from the ideal MHD marginal solution is discussed
Foundations of arithmetic differential geometry
Buium, Alexandru
2017-01-01
The aim of this book is to introduce and develop an arithmetic analogue of classical differential geometry. In this new geometry the ring of integers plays the role of a ring of functions on an infinite dimensional manifold. The role of coordinate functions on this manifold is played by the prime numbers. The role of partial derivatives of functions with respect to the coordinates is played by the Fermat quotients of integers with respect to the primes. The role of metrics is played by symmetric matrices with integer coefficients. The role of connections (respectively curvature) attached to metrics is played by certain adelic (respectively global) objects attached to the corresponding matrices. One of the main conclusions of the theory is that the spectrum of the integers is "intrinsically curved"; the study of this curvature is then the main task of the theory. The book follows, and builds upon, a series of recent research papers. A significant part of the material has never been published before.
Differential geometry of group lattices
International Nuclear Information System (INIS)
Dimakis, Aristophanes; Mueller-Hoissen, Folkert
2003-01-01
In a series of publications we developed ''differential geometry'' on discrete sets based on concepts of noncommutative geometry. In particular, it turned out that first-order differential calculi (over the algebra of functions) on a discrete set are in bijective correspondence with digraph structures where the vertices are given by the elements of the set. A particular class of digraphs are Cayley graphs, also known as group lattices. They are determined by a discrete group G and a finite subset S. There is a distinguished subclass of ''bicovariant'' Cayley graphs with the property ad(S)S subset of S. We explore the properties of differential calculi which arise from Cayley graphs via the above correspondence. The first-order calculi extend to higher orders and then allow us to introduce further differential geometric structures. Furthermore, we explore the properties of ''discrete'' vector fields which describe deterministic flows on group lattices. A Lie derivative with respect to a discrete vector field and an inner product with forms is defined. The Lie-Cartan identity then holds on all forms for a certain subclass of discrete vector fields. We develop elements of gauge theory and construct an analog of the lattice gauge theory (Yang-Mills) action on an arbitrary group lattice. Also linear connections are considered and a simple geometric interpretation of the torsion is established. By taking a quotient with respect to some subgroup of the discrete group, generalized differential calculi associated with so-called Schreier diagrams are obtained
Geometry of anisotropic CO outflows
International Nuclear Information System (INIS)
Liseau, R.; Sandell, G.; Helsinki Univ., Observatory, Finland)
1986-01-01
A simple geometrical model for the space motions of the bipolar high-velocity CO outflows in regions of recent, active star formation is proposed. It is assumed that the velocity field of the neutral gas component can be represented by large-scale uniform motions. From observations of the spatial distribution and from the characteristics of the line shape of the high-velocity molecular gas emission the geometry of the line-emitting regions can be inferred, i.e., the direction in space and the collimating angle of the flow. The model has been applied to regions where a check on presently obtained results is provided by independent optical determinations of the motions of Herbig-Haro objects associated with the CO flows. These two methods are in good agreement and, furthermore, the results obtained provide convincingly strong evidence for the physical association of CO outflows and Herbig-Haro objects. This also supports the common view that a young stellar central source is responsible for the active phenomena observed in its environmental neighborhood. It is noteworthy that within the framework of the model the determination of the flow geometry of the high-velocity gas from CO measurements is independent of the distance to the source and, furthermore, can be done at relatively low spatial resolution. 32 references
Canonical differential geometry of string backgrounds
International Nuclear Information System (INIS)
Schuller, Frederic P.; Wohlfarth, Mattias N.R.
2006-01-01
String backgrounds and D-branes do not possess the structure of Lorentzian manifolds, but that of manifolds with area metric. Area metric geometry is a true generalization of metric geometry, which in particular may accommodate a B-field. While an area metric does not determine a connection, we identify the appropriate differential geometric structure which is of relevance for the minimal surface equation in such a generalized geometry. In particular the notion of a derivative action of areas on areas emerges naturally. Area metric geometry provides new tools in differential geometry, which promise to play a role in the description of gravitational dynamics on D-branes
Assessment of the LV-C2 Stack Sampling Probe Location for Compliance with ANSI/HPS N13.1-1999
Energy Technology Data Exchange (ETDEWEB)
Glissmeyer, John A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Antonio, Ernest J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Flaherty, Julia E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
2015-09-01
This document reports on a series of tests conducted to assess the proposed air sampling location for the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Low-Activity Waste (LAW) C2V (LV-C2) exhaust stack with respect to the applicable criteria regarding the placement of an air sampling probe. Federal regulations require that a sampling probe be located in the exhaust stack according to the criteria established by the American National Standards Institute/Health Physics Society (ANSI/HPS) N13.1-1999, Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stack and Ducts of Nuclear Facilities. These criteria address the capability of the sampling probe to extract a sample that represents the effluent stream. The tests were conducted on the LV-C2 scale model system. Based on the scale model tests, the location proposed for the air sampling probe in the scale model stack meets the requirements of the ANSI/HPS N13.1-1999 standard for velocity uniformity, flow angle, gas tracer and particle tracer uniformity. Additional velocity uniformity and flow angle tests on the actual stack will be necessary during cold startup to confirm the validity of the scale model results in representing the actual stack.
DEFF Research Database (Denmark)
Flores, German Antonio Enriquez; Fotidis, Ioannis; Karakashev, Dimitar Borisov
2015-01-01
In this study, the individual and synergistic toxicity of the following xenobiotics: Benzalkonium Chloride (BKC), Proxel LV (PRX), P3 Hypochloran (HPC), Triton X-100 (TRX), and DOWFAX 63N10 (DWF), on anaerobic digestion (AD) process, was assessed. The experiments were performed in batch and conti......In this study, the individual and synergistic toxicity of the following xenobiotics: Benzalkonium Chloride (BKC), Proxel LV (PRX), P3 Hypochloran (HPC), Triton X-100 (TRX), and DOWFAX 63N10 (DWF), on anaerobic digestion (AD) process, was assessed. The experiments were performed in batch...... and continuous (up-flow anaerobic sludge blanket, UASB) reactors with biochemical-industrial wastewater, as substrate. In batch experiments, half-maximal inhibitory concentrations (IC50) for the tested xenobiotics were found to be 13.1, 1003, 311.5 and 24.3 mg L1 for BKC, PRX, DWF and TRX, respectively while HPC...... observed from the batch reactors. Oppositely, TRX showed no inhibition in continuous mode, while inhibition was detected at batch mode....
Sobrinho, Ludmila Silva Vicente; Rossi, Cláudio Nazaretian; Vides, Juliana Peloi; Braga, Eveline Tozzi; Gomes, Ana Amélia Domingues; de Lima, Valéria Marçal Félix; Perri, Sílvia Helena Venturoli; Generoso, Diego; Langoni, Hélio; Leutenegger, Christian; Biondo, Alexander Welker; Laurenti, Márcia Dalastra; Marcondes, Mary
2012-06-08
The aim of the present study was to determine the coinfection of Leishmania sp. with Toxoplasma gondii, Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV) in a population of cats from an endemic area for zoonotic visceral leishmaniasis. An overall 66/302 (21.85%) cats were found positive for Leishmania sp., with infection determined by direct parasitological examination in 30/302 (9.93%), by serology in 46/302 (15.23%) and by both in 10/302 (3.31%) cats. Real time PCR followed by amplicon sequencing successfully confirmed Leishmania infantum (syn Leishmania chagasi) infection. Out of the Leishmania infected cats, coinfection with FIV was observed in 12/66 (18.18%), with T. gondii in 17/66 (25.75%) and with both agents in 5/66 (7.58%) cats. FeLV was found only in a single adult cat with no Leishmania infection. A positive association was observed in coinfection of Leishmania and FIV (p0.05). In conclusion, cats living in endemic areas of visceral leishmaniasis are significantly more likely to be coinfected with FIV, which may present confounding clinical signs and therefore cats in such areas should be always carefully screened for coinfections. Copyright © 2012 Elsevier B.V. All rights reserved.
Vertex Normals and Face Curvatures of Triangle Meshes
Sun, Xiang
2016-08-12
This study contributes to the discrete differential geometry of triangle meshes, in combination with discrete line congruences associated with such meshes. In particular we discuss when a congruence defined by linear interpolation of vertex normals deserves to be called a ŉormal’ congruence. Our main results are a discussion of various definitions of normality, a detailed study of the geometry of such congruences, and a concept of curvatures and shape operators associated with the faces of a triangle mesh. These curvatures are compatible with both normal congruences and the Steiner formula.
International Nuclear Information System (INIS)
Grann, Alison; Minsky, Bruce D.; Cohen, Alfred M.; Saltz, Leonard; Kelsen, David P.; Kemeny, Nancy; Ilson, David; Guillem, Jose G.; Paty, Philip B.; Bass, Joanne
1996-01-01
PURPOSE: We report the downstaging, acute toxicity, and preliminary local control and survival of pre-op 5-FU, low dose LV, and concurrent RT followed by post-op LV/5-FU for pts with clinically resectable, T3 rectal cancer. MATERIALS AND METHODS: A total of 32 pts (M:26, F:6) were prospectively treated from 12/91-8/95. Eligibility criteria included adequate hematologic indicies, primary adenocarcinoma limited to the pelvis, and T3 disease confirmed by transrectal ultrasound. Twenty five pts were considered clinically to require an APR on initial (pre-treatment) assessment by their operating surgeon. The median age was 56 (range: 24-80), and the median distance from the anal verge was 5.0cm (range: 3-9cm). Pts received 2 monthly cycles (bolus daily X 5) of LV (20mg/m2) and 5-FU (325mg/m2), beginning concurrently with day 1 of RT, followed by surgery 4-5 weeks later. RT included 4680 cGy to the pelvis followed by a boost to 5040 cGy. Post-operatively, pts received a median of 2 monthly cycles (range: 0-10 cycles) of LV (20 mg/m2) and 5-FU (425mg/m2). A toxicity assessment was performed at each visit using the NCI toxicity criteria modified for gastrointestinal toxicity. The median follow-up was 12 months (range: 3-48 months). All 32 patients were included in the analysis of toxicity, sphincter preservation, and downstaging. Analysis of patterns of failure and survival was limited to the 15 pts who had a minimum follow-up of 1yr or developed failure prior to 1 yr. For this subset the median follow-up was 24 months (range: 3-48 months). RESULTS: During the pre-op segment, individual grade 3+ acute toxicities were; diarrhea: 16%, bowel movements: 16%, leukopenia: 12%. The incidence of total toxicity was 25% ((8(32))). The median nadir counts were; WBC: 2.9 (range: 1.7-5.6), HGB: 12.4 (range: 7.1-15.0), and PLT (X1000): 161 (range: 113-237). The pathologic complete response rate was 9% ((3(32))). An additional 13% ((4(32))) had negative lymph nodes and 1-2 microscopic
Differential Geometry Based Multiscale Models
Wei, Guo-Wei
2010-01-01
Large chemical and biological systems such as fuel cells, ion channels, molecular motors, and viruses are of great importance to the scientific community and public health. Typically, these complex systems in conjunction with their aquatic environment pose a fabulous challenge to theoretical description, simulation, and prediction. In this work, we propose a differential geometry based multiscale paradigm to model complex macromolecular systems, and to put macroscopic and microscopic descriptions on an equal footing. In our approach, the differential geometry theory of surfaces and geometric measure theory are employed as a natural means to couple the macroscopic continuum mechanical description of the aquatic environment with the microscopic discrete atom-istic description of the macromolecule. Multiscale free energy functionals, or multiscale action functionals are constructed as a unified framework to derive the governing equations for the dynamics of different scales and different descriptions. Two types of aqueous macromolecular complexes, ones that are near equilibrium and others that are far from equilibrium, are considered in our formulations. We show that generalized Navier–Stokes equations for the fluid dynamics, generalized Poisson equations or generalized Poisson–Boltzmann equations for electrostatic interactions, and Newton's equation for the molecular dynamics can be derived by the least action principle. These equations are coupled through the continuum-discrete interface whose dynamics is governed by potential driven geometric flows. Comparison is given to classical descriptions of the fluid and electrostatic interactions without geometric flow based micro-macro interfaces. The detailed balance of forces is emphasized in the present work. We further extend the proposed multiscale paradigm to micro-macro analysis of electrohydrodynamics, electrophoresis, fuel cells, and ion channels. We derive generalized Poisson–Nernst–Planck equations that
Differential geometry based multiscale models.
Wei, Guo-Wei
2010-08-01
Large chemical and biological systems such as fuel cells, ion channels, molecular motors, and viruses are of great importance to the scientific community and public health. Typically, these complex systems in conjunction with their aquatic environment pose a fabulous challenge to theoretical description, simulation, and prediction. In this work, we propose a differential geometry based multiscale paradigm to model complex macromolecular systems, and to put macroscopic and microscopic descriptions on an equal footing. In our approach, the differential geometry theory of surfaces and geometric measure theory are employed as a natural means to couple the macroscopic continuum mechanical description of the aquatic environment with the microscopic discrete atomistic description of the macromolecule. Multiscale free energy functionals, or multiscale action functionals are constructed as a unified framework to derive the governing equations for the dynamics of different scales and different descriptions. Two types of aqueous macromolecular complexes, ones that are near equilibrium and others that are far from equilibrium, are considered in our formulations. We show that generalized Navier-Stokes equations for the fluid dynamics, generalized Poisson equations or generalized Poisson-Boltzmann equations for electrostatic interactions, and Newton's equation for the molecular dynamics can be derived by the least action principle. These equations are coupled through the continuum-discrete interface whose dynamics is governed by potential driven geometric flows. Comparison is given to classical descriptions of the fluid and electrostatic interactions without geometric flow based micro-macro interfaces. The detailed balance of forces is emphasized in the present work. We further extend the proposed multiscale paradigm to micro-macro analysis of electrohydrodynamics, electrophoresis, fuel cells, and ion channels. We derive generalized Poisson-Nernst-Planck equations that are
Hopf algebras in noncommutative geometry
International Nuclear Information System (INIS)
Varilly, Joseph C.
2001-10-01
We give an introductory survey to the use of Hopf algebras in several problems of non- commutative geometry. The main example, the Hopf algebra of rooted trees, is a graded, connected Hopf algebra arising from a universal construction. We show its relation to the algebra of transverse differential operators introduced by Connes and Moscovici in order to compute a local index formula in cyclic cohomology, and to the several Hopf algebras defined by Connes and Kreimer to simplify the combinatorics of perturbative renormalization. We explain how characteristic classes for a Hopf module algebra can be obtained from the cyclic cohomology of the Hopf algebra which acts on it. Finally, we discuss the theory of non- commutative spherical manifolds and show how they arise as homogeneous spaces of certain compact quantum groups. (author)
Integrable systems, geometry, and topology
Terng, Chuu-Lian
2006-01-01
The articles in this volume are based on lectures from a program on integrable systems and differential geometry held at Taiwan's National Center for Theoretical Sciences. As is well-known, for many soliton equations, the solutions have interpretations as differential geometric objects, and thereby techniques of soliton equations have been successfully applied to the study of geometric problems. The article by Burstall gives a beautiful exposition on isothermic surfaces and their relations to integrable systems, and the two articles by Guest give an introduction to quantum cohomology, carry out explicit computations of the quantum cohomology of flag manifolds and Hirzebruch surfaces, and give a survey of Givental's quantum differential equations. The article by Heintze, Liu, and Olmos is on the theory of isoparametric submanifolds in an arbitrary Riemannian manifold, which is related to the n-wave equation when the ambient manifold is Euclidean. Mukai-Hidano and Ohnita present a survey on the moduli space of ...
Tarski Geometry Axioms. Part III
Directory of Open Access Journals (Sweden)
Coghetto Roland
2017-12-01
Full Text Available In the article, we continue the formalization of the work devoted to Tarski’s geometry - the book “Metamathematische Methoden in der Geometrie” by W. Schwabhäuser, W. Szmielew, and A. Tarski. After we prepared some introductory formal framework in our two previous Mizar articles, we focus on the regular translation of underlying items faithfully following the abovementioned book (our encoding covers first seven chapters. Our development utilizes also other formalization efforts of the same topic, e.g. Isabelle/HOL by Makarios, Metamath or even proof objects obtained directly from Prover9. In addition, using the native Mizar constructions (cluster registrations the propositions (“Satz” are reformulated under weaker conditions, i.e. by using fewer axioms or by proposing an alternative version that uses just another axioms (ex. Satz 2.1 or Satz 2.2.
Applied geometry and discrete mathematics
Sturm; Gritzmann, Peter; Sturmfels, Bernd
1991-01-01
This volume, published jointly with the Association for Computing Machinery, comprises a collection of research articles celebrating the occasion of Victor Klee's sixty-fifth birthday in September 1990. During his long career, Klee has made contributions to a wide variety of areas, such as discrete and computational geometry, convexity, combinatorics, graph theory, functional analysis, mathematical programming and optimization, and theoretical computer science. In addition, Klee made important contributions to mathematics education, mathematical methods in economics and the decision sciences, applications of discrete mathematics in the biological and social sciences, and the transfer of knowledge from applied mathematics to industry. In honor of Klee's achievements, this volume presents more than forty papers on topics related to Klee's research. While the majority of the papers are research articles, a number of survey articles are also included. Mirroring the breadth of Klee's mathematical contributions, th...
Introduction to global variational geometry
Krupka, Demeter
2015-01-01
The book is devoted to recent research in the global variational theory on smooth manifolds. Its main objective is an extension of the classical variational calculus on Euclidean spaces to (topologically nontrivial) finite-dimensional smooth manifolds; to this purpose the methods of global analysis of differential forms are used. Emphasis is placed on the foundations of the theory of variational functionals on fibered manifolds - relevant geometric structures for variational principles in geometry, physical field theory and higher-order fibered mechanics. The book chapters include: - foundations of jet bundles and analysis of differential forms and vector fields on jet bundles, - the theory of higher-order integral variational functionals for sections of a fibred space, the (global) first variational formula in infinitesimal and integral forms- extremal conditions and the discussion of Noether symmetries and generalizations,- the inverse problems of the calculus of variations of Helmholtz type- variational se...
Some Progress in Conformal Geometry
Directory of Open Access Journals (Sweden)
Sun-Yung A. Chang
2007-12-01
Full Text Available This is a survey paper of our current research on the theory of partial differential equations in conformal geometry. Our intention is to describe some of our current works in a rather brief and expository fashion. We are not giving a comprehensive survey on the subject and references cited here are not intended to be complete. We introduce a bubble tree structure to study the degeneration of a class of Yamabe metrics on Bach flat manifolds satisfying some global conformal bounds on compact manifolds of dimension 4. As applications, we establish a gap theorem, a finiteness theorem for diffeomorphism type for this class, and diameter bound of the $sigma_2$-metrics in a class of conformal 4-manifolds. For conformally compact Einstein metrics we introduce an eigenfunction compactification. As a consequence we obtain some topological constraints in terms of renormalized volumes.
Seesaw mechanism in warped geometry
International Nuclear Information System (INIS)
Huber, S.J.; Shafi, Q.
2003-09-01
We show how the seesaw mechanism for neutrino masses can be realized within a five dimensional (5D) warped geometry framework. Intermediate scale standard model (SM) singlet neutrino masses, needed to explain the atmospheric and solar neutrino oscillations, are shown to be proportional to M P1 .exp((2c-1)πkR), where c denotes the coefficient of the 5D Dirac mass term for the singlet neutrino which also has a Planck scale Majorana mass localized on the Planck-brane, and kR∼11 in order to resolve the gauge hierarchy problem. The case with a bulk 5D Majorana mass term for the singlet neutrino is briefly discussed. (orig.)
Seesaw mechanism in warped geometry
International Nuclear Information System (INIS)
Huber, Stephan J.; Shafi, Qaisar
2004-01-01
We show how the seesaw mechanism for neutrino masses can be realized within a five-dimensional (5D) warped geometry framework. Intermediate scale standard model (SM) singlet neutrino masses, needed to explain the atmospheric and solar neutrino oscillations, are shown to be proportional to M Pl exp((2c-1)πkR), where c denotes the coefficient of the 5D Dirac mass term for the singlet neutrino which also has a Planck scale Majorana mass localized on the Planck-brane, and kR∼11 in order to resolve the gauge hierarchy problem. The case with a bulk 5D Majorana mass term for the singlet neutrino is briefly discussed
Conformal geometry and quasiregular mappings
Vuorinen, Matti
1988-01-01
This book is an introduction to the theory of spatial quasiregular mappings intended for the uninitiated reader. At the same time the book also addresses specialists in classical analysis and, in particular, geometric function theory. The text leads the reader to the frontier of current research and covers some most recent developments in the subject, previously scatterd through the literature. A major role in this monograph is played by certain conformal invariants which are solutions of extremal problems related to extremal lengths of curve families. These invariants are then applied to prove sharp distortion theorems for quasiregular mappings. One of these extremal problems of conformal geometry generalizes a classical two-dimensional problem of O. Teichmüller. The novel feature of the exposition is the way in which conformal invariants are applied and the sharp results obtained should be of considerable interest even in the two-dimensional particular case. This book combines the features of a textbook an...
Quantization of the Schwarzschild geometry
International Nuclear Information System (INIS)
Melas, Evangelos
2013-01-01
The conditional symmetries of the reduced Einstein-Hilbert action emerging from a static, spherically symmetric geometry are used as supplementary conditions on the wave function. Based on their integrability conditions, only one of the three existing symmetries can be consistently imposed, while the unique Casimir invariant, being the product of the remaining two symmetries, is calculated as the only possible second condition on the wave function. This quadratic integral of motion is identified with the reparametrization generator, as an implication of the uniqueness of the dynamical evolution, by fixing a suitable parametrization of the r-lapse function. In this parametrization, the determinant of the supermetric plays the role of the mesure. The combined Wheeler – DeWitt and linear conditional symmetry equations are analytically solved. The solutions obtained depend on the product of the two ''scale factors''.
Eliashberg, Yakov; Maeda, Yoshiaki; Symplectic, Poisson, and Noncommutative geometry
2014-01-01
Symplectic geometry originated in physics, but it has flourished as an independent subject in mathematics, together with its offspring, symplectic topology. Symplectic methods have even been applied back to mathematical physics. Noncommutative geometry has developed an alternative mathematical quantization scheme based on a geometric approach to operator algebras. Deformation quantization, a blend of symplectic methods and noncommutative geometry, approaches quantum mechanics from a more algebraic viewpoint, as it addresses quantization as a deformation of Poisson structures. This volume contains seven chapters based on lectures given by invited speakers at two May 2010 workshops held at the Mathematical Sciences Research Institute: Symplectic and Poisson Geometry in Interaction with Analysis, Algebra and Topology (honoring Alan Weinstein, one of the key figures in the field) and Symplectic Geometry, Noncommutative Geometry and Physics. The chapters include presentations of previously unpublished results and ...
Convection in Slab and Spheroidal Geometries
Porter, David H.; Woodward, Paul R.; Jacobs, Michael L.
2000-01-01
Three-dimensional numerical simulations of compressible turbulent thermally driven convection, in both slab and spheroidal geometries, are reviewed and analyzed in terms of velocity spectra and mixing-length theory. The same ideal gas model is used in both geometries, and resulting flows are compared. The piecewise-parabolic method (PPM), with either thermal conductivity or photospheric boundary conditions, is used to solve the fluid equations of motion. Fluid motions in both geometries exhibit a Kolmogorov-like k(sup -5/3) range in their velocity spectra. The longest wavelength modes are energetically dominant in both geometries, typically leading to one convection cell dominating the flow. In spheroidal geometry, a dipolar flow dominates the largest scale convective motions. Downflows are intensely turbulent and up drafts are relatively laminar in both geometries. In slab geometry, correlations between temperature and velocity fluctuations, which lead to the enthalpy flux, are fairly independent of depth. In spheroidal geometry this same correlation increases linearly with radius over the inner 70 percent by radius, in which the local pressure scale heights are a sizable fraction of the radius. The effects from the impenetrable boundary conditions in the slab geometry models are confused with the effects from non-local convection. In spheroidal geometry nonlocal effects, due to coherent plumes, are seen as far as several pressure scale heights from the lower boundary and are clearly distinguishable from boundary effects.
Secant cumulants and toric geometry
Michalek, M.; Oeding, L.; Zwiernik, P.W.
2012-01-01
We study the secant line variety of the Segre product of projective spaces using special cumulant coordinates adapted for secant varieties. We show that the secant variety is covered by open normal toric varieties. We prove that in cumulant coordinates its ideal is generated by binomial quadrics. We
Deformation associated with continental normal faults
Resor, Phillip G.
Deformation associated with normal fault earthquakes and geologic structures provide insights into the seismic cycle as it unfolds over time scales from seconds to millions of years. Improved understanding of normal faulting will lead to more accurate seismic hazard assessments and prediction of associated structures. High-precision aftershock locations for the 1995 Kozani-Grevena earthquake (Mw 6.5), Greece image a segmented master fault and antithetic faults. This three-dimensional fault geometry is typical of normal fault systems mapped from outcrop or interpreted from reflection seismic data and illustrates the importance of incorporating three-dimensional fault geometry in mechanical models. Subsurface fault slip associated with the Kozani-Grevena and 1999 Hector Mine (Mw 7.1) earthquakes is modeled using a new method for slip inversion on three-dimensional fault surfaces. Incorporation of three-dimensional fault geometry improves the fit to the geodetic data while honoring aftershock distributions and surface ruptures. GPS Surveying of deformed bedding surfaces associated with normal faulting in the western Grand Canyon reveals patterns of deformation that are similar to those observed by interferometric satellite radar interferometry (InSAR) for the Kozani Grevena earthquake with a prominent down-warp in the hanging wall and a lesser up-warp in the footwall. However, deformation associated with the Kozani-Grevena earthquake extends ˜20 km from the fault surface trace, while the folds in the western Grand Canyon only extend 500 m into the footwall and 1500 m into the hanging wall. A comparison of mechanical and kinematic models illustrates advantages of mechanical models in exploring normal faulting processes including incorporation of both deformation and causative forces, and the opportunity to incorporate more complex fault geometry and constitutive properties. Elastic models with antithetic or synthetic faults or joints in association with a master
Krämer, Johannes; Bijnens, Bart; Störk, Stefan; Ritter, Christian O; Liu, Dan; Ertl, Georg; Wanner, Christoph; Weidemann, Frank
2015-01-01
In spite of several research studies help to describe the heart in Fabry disease (FD), the cardiomyopathy is not entirely understood. In addition, the impact of blood pressure and alterations in geometry have not been systematically evaluated. In 74 FD patients (mean age 36±12 years; 45 females) the extent of myocardial fibrosis and its progression were quantified using cardiac magnetic-resonance-imaging with late enhancement technique (LE). Results were compared to standard echocardiography complemented by 2D-speckle-tracking, 3D-sphericity-index (SI) and standardized blood pressure measurement. At baseline, no patient received enzyme replacement therapy (ERT). After 51±24 months, a follow-up examination was performed. Systolic blood pressure (SBP) was higher in patients with vs. without LE: 123±17 mmHg vs. 115±13 mmHg; P = 0.04. A positive correlation was found between SI and the amount of LE-positive myocardium (r = 0.51; PAUC = 0.785; P<0.05). LV geometry as assessed by the sphericity index is altered in relation to the stage of the Fabry cardiomyopathy. Although patients with FD are not hypertensive, the SBP has a clear impact on the progression of the cardiomyopathy.
Cell biology, MRI and geometry: insight into a microscopic/macroscopic marriage.
de Oliveira, Sérgio Almeida; Gowdak, Luís Henrique W; Buckberg, Gerald; Krieger, José Eduardo
2006-04-01
The concept of cell therapy as an adjunctive therapy to myocardial surgical revascularization for patients with severe coronary artery disease is illustrated by two case reports of ischemic cardiac disease that were unsuitable for revascularization by coronary grafting. The potential interaction of cell therapy, magnetic resonance imaging (MRI) of viability, and left ventricle (LV) restoration is described. Each patient had an ejection fraction below 30%, a relatively conical heart, and MRI gadolinium scan showing predominantly viable muscle. Intramyocardial injections of autologous bone marrow-derived cells (BMC) were performed along with either incomplete coronary artery bypass grafting (CABG) (to mother regions) or with transmyocardial laser revascularization (TMLR). An improvement in contractile function was seen at 6-12-month intervals after the procedure. The implications of possible underlying mechanisms of improvement in both myocardial perfusion and contractility suggest the striking importance of both micro- and macroenvironment for any cell-based therapeutic strategy. These observations imply that the interaction of cell biology, viability by MRI and geometry may be important in the future, as geometry can be restored surgically, and the new architectural form may develop enhanced function if it contains viable tissue and cell-based treatment can be delivered.
Tsuda, Takeshi; Shillingford, Amanda J.; Vetter, Jane; Kandula, Vinay; Jain, Badal; Temple, Joel
2017-01-01
Danon disease is a rare X-linked dominant skeletal and cardiac muscle disorder presenting with hypertrophic cardiomyopathy, Wolf-Parkinson-White syndrome, skeletal myopathy, and mild intellectual disability. Early morbidity and mortality due to heart failure or sudden death are known in Danon disease, more in males than in females. Here, we present a 17-year-old female adolescent with Danon disease and severe concentric hypertrophy with normal left ventricular (LV) systolic function, who has ...
International Nuclear Information System (INIS)
Serrano R, M. L.
2015-09-01
This article describes some of the work done in the Comision Nacional de Seguridad Nuclear y Salvaguardias (CNSNS) to define specifically the requirements that the Federal Electricity Commission (CFE) shall meet to submit for consideration of CNSNS an operation request of an Independent Spent Fuel Dry Storage Installation (ISFSI). The project of a facility of this type arose from the need to provide storage capacity for spent nuclear fuel in the nuclear power plant of Laguna Verde (NPP-LV) and to continue the operation at the same facility in a safe manner. The licensing of these facilities in the United States of America has two modes: specific license or general license. The characteristics of these licenses are described in this article. However, in Mexico the existing national legislation is not designed for such license types, in fact there is a lack of standards or regulations in this regard. The regulatory law of Article 27 of the Constitution in the nuclear matter, only generally establishes that this type of facility requires an authorization from the Ministry of Energy. For this reason and because there is not a national legislation, was necessary to use the legislation that provides the Nuclear Regulatory Commission of USA, the US NRC. However, it cannot be applied as is established, so was necessary that the CNSNS analyze one by one the requirements of both types of license and determine what would be required to NPP-LV to submit its operating license of ISFSI. The American regulatory applicable to an ISFSI, the 10-Cfr-72 of the US NRC, establishes the requirements for both types of licenses. Chapter 10-Cfr was analyzed in all its clauses and coupled to the laws, regulations and standards as well as to the requirements established by CNSNS, all associated with a store spent fuel on site; the respective certification of containers for spent fuel dry storage was not included in this article, even though the CNSNS also performed that activity under the
Yu, P. S.; Liao, C. J.; Chen, M. T.; Zou, J. J.; Shi, X.; Bosin, A. A.; Gorbarenko, S. A.
2017-12-01
Sea surface temperature (SST) records from the subarctic Northwestern (NW) Pacific are ideal for reconstructing regional paleoceanographic changes sensitive to global climate change. Core LV 63-41-2 (52.56°N, 160.00° E; water depth 1924 m) retrieved from a high sedimentation site, in which the interactions of the Bering Sea and the warm water mass from the NW Pacific are highly dynamic. Here we reported high-resolution last glacial alkenone-based records from Core LV 63-41-2. Prior to 27-16 ka BP high glacial C37:4 alkenone concentrations indicate large amount of fresh water influencing the surface water of the NW Pacific with a reaching to the Site LV 63-41-2. We further inferred that during the last glacial the low salinity water may be formed from the ice-melting water on site and/or brought by the surface current from the Bering Sea, and are efficient in producing strong water stratification condition. The stratification weakens vertical mixing of the upper water column, that in turn decreases the nutrients upwelled from deep to the surface therefore causes low productivity of coccolithophorids. During the early Bølling-Allerød (B/A) period, a gradual increasing alkenone-SST and associated with high C37:4 alkenone concentrations, implying that a weakened stratification and much stronger nutrient upwelling of the early B/A period than that of the glacial. The late B/A period is characterized by an abrupt warming with possibly more melting sea ices in the Bering Sea and the coast near the Kamchatka Peninsula. The large amount of fresh water lens formed during the ice melting might have ceased vertical mixing and upwelling in the upper water column as evidenced by a decline of biological productivity of both calcerous and soliceous organism during late B/A. We suggest an early warming and low productivity in the NW Pacific that is coincident with a rapid cooling in most of the Northern Hemisphere high latitudes during the Younger Dryas.
Connections between algebra, combinatorics, and geometry
Sather-Wagstaff, Sean
2014-01-01
Commutative algebra, combinatorics, and algebraic geometry are thriving areas of mathematical research with a rich history of interaction. Connections Between Algebra, Combinatorics, and Geometry contains lecture notes, along with exercises and solutions, from the Workshop on Connections Between Algebra and Geometry held at the University of Regina from May 29-June 1, 2012. It also contains research and survey papers from academics invited to participate in the companion Special Session on Interactions Between Algebraic Geometry and Commutative Algebra, which was part of the CMS Summer Meeting at the University of Regina held June 2–3, 2012, and the meeting Further Connections Between Algebra and Geometry, which was held at the North Dakota State University, February 23, 2013. This volume highlights three mini-courses in the areas of commutative algebra and algebraic geometry: differential graded commutative algebra, secant varieties, and fat points and symbolic powers. It will serve as a useful resou...
Second International workshop Geometry and Symbolic Computation
Walczak, Paweł; Geometry and its Applications
2014-01-01
This volume has been divided into two parts: Geometry and Applications. The geometry portion of the book relates primarily to geometric flows, laminations, integral formulae, geometry of vector fields on Lie groups, and osculation; the articles in the applications portion concern some particular problems of the theory of dynamical systems, including mathematical problems of liquid flows and a study of cycles for non-dynamical systems. This Work is based on the second international workshop entitled "Geometry and Symbolic Computations," held on May 15-18, 2013 at the University of Haifa and is dedicated to modeling (using symbolic calculations) in differential geometry and its applications in fields such as computer science, tomography, and mechanics. It is intended to create a forum for students and researchers in pure and applied geometry to promote discussion of modern state-of-the-art in geometric modeling using symbolic programs such as Maple™ and Mathematica®, as well as presentation of new results. ...
A vector space approach to geometry
Hausner, Melvin
2010-01-01
The effects of geometry and linear algebra on each other receive close attention in this examination of geometry's correlation with other branches of math and science. In-depth discussions include a review of systematic geometric motivations in vector space theory and matrix theory; the use of the center of mass in geometry, with an introduction to barycentric coordinates; axiomatic development of determinants in a chapter dealing with area and volume; and a careful consideration of the particle problem. 1965 edition.
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
Flow equation, conformal symmetry, and anti-de Sitter geometry
Aoki, Sinya; Yokoyama, Shuichi
2018-03-01
We argue that the anti-de Sitter (AdS) geometry in d+1 dimensions naturally emerges from an arbitrary conformal field theory in d dimensions using the free flow equation. We first show that an induced metric defined from the flowed field generally corresponds to the quantum information metric, called the Bures or Helstrom metric, if the flowed field is normalized appropriately. We next verify that the induced metric computed explicitly with the free flow equation always becomes the AdS metric when the theory is conformal. We finally prove that the conformal symmetry in d dimensions converts to the AdS isometry in d+1 dimensions after d-dimensional quantum averaging. This guarantees the emergence of AdS geometry without explicit calculation.
Cong, Wei; Meng, Qing-Feng; Blaga, Radu; Villena, Isabelle; Zhu, Xing-Quan; Qian, Ai-Dong
2016-01-01
This study was conducted to estimate the prevalence of Toxoplasma gondii, Dirofilaria immitis, feline immunodeficiency virus (FIV), and feline leukemia virus (FeLV) infections among stray and pet cats in Lanzhou, northwest China, and to identify the influence of age, gender, and regions on seropositivity. T. gondii antibodies were examined in cat sera by the modified agglutination test (MAT). The circulating antigens of D. immitis and FeLV and specific antibodies to FIV were examined using kits commercially available. The overall prevalence of T. gondii, FIV, FeLV, and D. immitis was 19.34, 9.12, 11.33, and 3.04 %, respectively. For the genetic characterization of T. gondii genotypes in cats, genomic DNA was extracted from the seropositive cats and the T. gondii B1 gene was amplified using a semi-nested PCR. DNA samples giving positive B1 amplification were then genotyped using multilocus PCR-RFLP. Two T. gondii genotypes (ToxoDB#9 and ToxoDB#1) were identified. Results of the multivariate logistic regression analysis showed that older cats are more likely to be seropositive than juveniles for T. gondii, FIV, FeLV, and D. immitis. This is the first report of T. gondii genotypes in cats in northwest China. Moreover, the present study is the first study of retrovirus and D. immitis seroprevalence in cats in China. The results revealed that T. gondii, FIV, and FeLV infections are common in stray and pet cats in northwest China.
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
Disformal transformation in Newton-Cartan geometry
Energy Technology Data Exchange (ETDEWEB)
Huang, Peng [Zhejiang Chinese Medical University, Department of Information, Hangzhou (China); Sun Yat-Sen University, School of Physics and Astronomy, Guangzhou (China); Yuan, Fang-Fang [Nankai University, School of Physics, Tianjin (China)
2016-08-15
Newton-Cartan geometry has played a central role in recent discussions of the non-relativistic holography and condensed matter systems. Although the conformal transformation in non-relativistic holography can easily be rephrased in terms of Newton-Cartan geometry, we show that it requires a nontrivial procedure to arrive at the consistent form of anisotropic disformal transformation in this geometry. Furthermore, as an application of the newly obtained transformation, we use it to induce a geometric structure which may be seen as a particular non-relativistic version of the Weyl integrable geometry. (orig.)
Applications of Affine and Weyl geometry
García-Río, Eduardo; Nikcevic, Stana
2013-01-01
Pseudo-Riemannian geometry is, to a large extent, the study of the Levi-Civita connection, which is the unique torsion-free connection compatible with the metric structure. There are, however, other affine connections which arise in different contexts, such as conformal geometry, contact structures, Weyl structures, and almost Hermitian geometry. In this book, we reverse this point of view and instead associate an auxiliary pseudo-Riemannian structure of neutral signature to certain affine connections and use this correspondence to study both geometries. We examine Walker structures, Riemannia
Special Geometry and Automorphic Forms
Berglund, P; Wyllard, N; Berglund, Per; Henningson, Mans; Wyllard, Niclas
1997-01-01
We consider special geometry of the vector multiplet moduli space in compactifications of the heterotic string on $K3 \\times T^2$ or the type IIA string on $K3$-fibered Calabi-Yau threefolds. In particular, we construct a modified dilaton that is invariant under $SO(2, n; Z)$ T-duality transformations at the non-perturbative level and regular everywhere on the moduli space. The invariant dilaton, together with a set of other coordinates that transform covariantly under $SO(2, n; Z)$, parameterize the moduli space. The construction involves a meromorphic automorphic function of $SO(2, n; Z)$, that also depends on the invariant dilaton. In the weak coupling limit, the divisor of this automorphic form is an integer linear combination of the rational quadratic divisors where the gauge symmetry is enhanced classically. We also show how the non-perturbative prepotential can be expressed in terms of meromorphic automorphic forms, by expanding a T-duality invariant quantity both in terms of the standard special coord...
Differential geometry in string models
International Nuclear Information System (INIS)
Alvarez, O.
1986-01-01
In this article the author reviews the differential geometric approach to the quantization of strings. A seminal paper demonstrates the connection between the trace anomaly and the critical dimension. The role played by the Faddeev-Popov ghosts has been instrumental in much of the subsequent work on the quantization of strings. This paper discusses the differential geometry of two dimensional surfaces and its importance in the quantization of strings. The path integral quantization approach to strings will be carefully analyzed to determine the correct effective measure for string theories. The choice of measure for the path integral is determined by differential geometric considerations. Once the measure is determined, the manifest diffeomorphism invariance of the theory will have to be broken by using the Faddeev-Popov ansatz. The gauge fixed theory is studied in detail with emphasis on the role of conformal and gravitational anomalies. In the analysis, the path integral formulation of the gauge fixed theory requires summing over all the distinct complex structures on the manifold
Geometry of lattice field theory
International Nuclear Information System (INIS)
Honan, T.J.
1986-01-01
Using some tools of algebraic topology, a general formalism for lattice field theory is presented. The lattice is taken to be a simplicial complex that is also a manifold and is referred to as a simplicial manifold. The fields on this lattice are cochains, that are called lattice forms to emphasize the connections with differential forms in the continuum. This connection provides a new bridge between lattice and continuum field theory. A metric can be put onto this simplicial manifold by assigning lengths to every link or I-simplex of the lattice. Regge calculus is a way of defining general relativity on this lattice. A geometric discussion of Regge calculus is presented. The Regge action, which is a discrete form of the Hilbert action, is derived from the Hilbert action using distribution valued forms. This is a new derivation that emphasizes the underlying geometry. Kramers-Wannier duality in statistical mechanics is discussed in this general setting. Nonlinear field theories, which include gauge theories and nonlinear sigma models are discussed in the continuum and then are put onto a lattice. The main new result here is the generalization to curved spacetime, which consists of making the theory compatible with Regge calculus
Latent geometry of bipartite networks
Kitsak, Maksim; Papadopoulos, Fragkiskos; Krioukov, Dmitri
2017-03-01
Despite the abundance of bipartite networked systems, their organizing principles are less studied compared to unipartite networks. Bipartite networks are often analyzed after projecting them onto one of the two sets of nodes. As a result of the projection, nodes of the same set are linked together if they have at least one neighbor in common in the bipartite network. Even though these projections allow one to study bipartite networks using tools developed for unipartite networks, one-mode projections lead to significant loss of information and artificial inflation of the projected network with fully connected subgraphs. Here we pursue a different approach for analyzing bipartite systems that is based on the observation that such systems have a latent metric structure: network nodes are points in a latent metric space, while connections are more likely to form between nodes separated by shorter distances. This approach has been developed for unipartite networks, and relatively little is known about its applicability to bipartite systems. Here, we fully analyze a simple latent-geometric model of bipartite networks and show that this model explains the peculiar structural properties of many real bipartite systems, including the distributions of common neighbors and bipartite clustering. We also analyze the geometric information loss in one-mode projections in this model and propose an efficient method to infer the latent pairwise distances between nodes. Uncovering the latent geometry underlying real bipartite networks can find applications in diverse domains, ranging from constructing efficient recommender systems to understanding cell metabolism.
Fractal Geometry and Stochastics V
Falconer, Kenneth; Zähle, Martina
2015-01-01
This book brings together leading contributions from the fifth conference on Fractal Geometry and Stochastics held in Tabarz, Germany, in March 2014. The book is divided into five sections covering different facets of this fast developing area: geometric measure theory, self-similar fractals and recurrent structures, analysis and algebra on fractals, multifractal theory, and random constructions. There are state-of-the-art surveys as well as papers highlighting more specific recent advances. The authors are world-experts who present their topics comprehensibly and attractively. The book provides an accessible gateway to the subject for newcomers as well as a reference for recent developments for specialists. Authors include: Krzysztof Barański, Julien Barral, Kenneth Falconer, De-Jun Feng, Peter J. Grabner, Rostislav Grigorchuk, Michael Hinz, Stéphane Jaffard, Maarit Järvenpää, Antti Käenmäki, Marc Kesseböhmer, Michel Lapidus, Klaus Mecke, Mark Pollicott, Michał Rams, Pablo Shmerkin, and András Te...
Stochastic geometry in PRIZMA code
International Nuclear Information System (INIS)
Malyshkin, G. N.; Kashaeva, E. A.; Mukhamadiev, R. F.
2007-01-01
The paper describes a method used to simulate radiation transport through random media - randomly placed grains in a matrix material. The method models the medium consequently from one grain crossed by particle trajectory to another. Like in the Limited Chord Length Sampling (LCLS) method, particles in grains are tracked in the actual grain geometry, but unlike LCLS, the medium is modeled using only Matrix Chord Length Sampling (MCLS) from the exponential distribution and it is not necessary to know the grain chord length distribution. This helped us extend the method to media with randomly oriented arbitrarily shaped convex grains. Other extensions include multicomponent media - grains of several sorts, and polydisperse media - grains of different sizes. Sort and size distributions of crossed grains were obtained and an algorithm was developed for sampling grain orientations and positions. Special consideration was given to medium modeling at the boundary of the stochastic region. The method was implemented in the universal 3D Monte Carlo code PRIZMA. The paper provides calculated results for a model problem where we determine volume fractions of modeled components crossed by particle trajectories. It also demonstrates the use of biased sampling techniques implemented in PRIZMA for solving a problem of deep penetration in model random media. Described are calculations for the spectral response of a capacitor dose detector whose anode was modeled with account for its stochastic structure. (authors)
The geometry of population genetics
Akin, Ethan
1979-01-01
The differential equations which model the action of selection and recombination are nonlinear equations which are impossible to It is even difficult to describe in general the solve explicitly. Recently, Shahshahani began using qualitative behavior of solutions. differential geometry to study these equations [28]. with this mono graph I hope to show that his ideas illuminate many aspects of pop ulation genetics. Among these are his proof and clarification of Fisher's Fundamental Theorem of Natural Selection and Kimura's Maximum Principle and also the effect of recombination on entropy. We also discover the relationship between two classic measures of 2 genetic distance: the x measure and the arc-cosine measure. There are two large applications. The first is a precise definition of the biological concept of degree of epistasis which applies to general (i.e. frequency dependent) forms of selection. The second is the unexpected appearance of cycling. We show that cycles can occur in the two-locus-two-allele...
Topics in Cubic Special Geometry
Bellucci, Stefano; Roychowdhury, Raju
2011-01-01
We reconsider the sub-leading quantum perturbative corrections to N=2 cubic special Kaehler geometries. Imposing the invariance under axion-shifts, all such corrections (but the imaginary constant one) can be introduced or removed through suitable, lower unitriangular symplectic transformations, dubbed Peccei-Quinn (PQ) transformations. Since PQ transformations do not belong to the d=4 U-duality group G4, in symmetric cases they generally have a non-trivial action on the unique quartic invariant polynomial I4 of the charge representation R of G4. This leads to interesting phenomena in relation to theory of extremal black hole attractors; namely, the possibility to make transitions between different charge orbits of R, with corresponding change of the supersymmetry properties of the supported attractor solutions. Furthermore, a suitable action of PQ transformations can also set I4 to zero, or vice versa it can generate a non-vanishing I4: this corresponds to transitions between "large" and "small" charge orbit...
Normalized modes at selected points without normalization
Kausel, Eduardo
2018-04-01
As every textbook on linear algebra demonstrates, the eigenvectors for the general eigenvalue problem | K - λM | = 0 involving two real, symmetric, positive definite matrices K , M satisfy some well-defined orthogonality conditions. Equally well-known is the fact that those eigenvectors can be normalized so that their modal mass μ =ϕT Mϕ is unity: it suffices to divide each unscaled mode by the square root of the modal mass. Thus, the normalization is the result of an explicit calculation applied to the modes after they were obtained by some means. However, we show herein that the normalized modes are not merely convenient forms of scaling, but that they are actually intrinsic properties of the pair of matrices K , M, that is, the matrices already "know" about normalization even before the modes have been obtained. This means that we can obtain individual components of the normalized modes directly from the eigenvalue problem, and without needing to obtain either all of the modes or for that matter, any one complete mode. These results are achieved by means of the residue theorem of operational calculus, a finding that is rather remarkable inasmuch as the residues themselves do not make use of any orthogonality conditions or normalization in the first place. It appears that this obscure property connecting the general eigenvalue problem of modal analysis with the residue theorem of operational calculus may have been overlooked up until now, but which has in turn interesting theoretical implications.Á
Energy Technology Data Exchange (ETDEWEB)
Perusquia, R.; Arredondo S, C.; Hernandez M, J. L.; Montes T, J. L.; Castillo M, A.; Ortiz S, J. J., E-mail: raul.perusquia@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)
2015-09-15
This paper presents the development of tools to facilitate the management so much, the operational monitoring of boiling water reactors (BWR) of the nuclear power plant of Laguna Verde (NPP-LV) through independent codes, and how to carry out the static calculations corresponding to process of optimized pre-design of the reference cycle next to current cycle. The progress and preliminary results obtained with the program SACal, developed at Instituto Nacional de Investigaciones Nucleares (ININ), central tool to achieve provide a management platform of the operational monitoring and pre-design of NPP-LV cycle are also described. The reached preliminary advances directed to get an Analysis center and automated design of fuel assembly cells are also presented, which together with centers or similar modules related with the fuel reloads form the key part to meet the targets set for the realization of a Management Platform of Nuclear Fuel of the NPP-LV. (Author)
Quantum groups: Geometry and applications
International Nuclear Information System (INIS)
Chu, C.S.
1996-01-01
The main theme of this thesis is a study of the geometry of quantum groups and quantum spaces, with the hope that they will be useful for the construction of quantum field theory with quantum group symmetry. The main tool used is the Faddeev-Reshetikhin-Takhtajan description of quantum groups. A few content-rich examples of quantum complex spaces with quantum group symmetry are treated in details. In chapter 1, the author reviews some of the basic concepts and notions for Hopf algebras and other background materials. In chapter 2, he studies the vector fields of quantum groups. A compact realization of these vector fields as pseudodifferential operators acting on the linear quantum spaces is given. In chapter 3, he describes the quantum sphere as a complex quantum manifold by means of a quantum stereographic projection. A covariant calculus is introduced. An interesting property of this calculus is the existence of a one-form realization of the exterior differential operator. The concept of a braided comodule is introduced and a braided algebra of quantum spheres is constructed. In chapter 4, the author considers the more general higher dimensional quantum complex projective spaces and the quantum Grassman manifolds. Differential calculus, integration and braiding can be introduced as in the one dimensional case. Finally, in chapter 5, he studies the framework of quantum principal bundle and construct the q-deformed Dirac monopole as a quantum principal bundle with a quantum sphere as the base and a U(1) with non-commutative calculus as the fiber. The first Chern class can be introduced and integrated to give the monopole charge
The geometry of elementary particles
International Nuclear Information System (INIS)
Lov, T.R.
1987-01-01
A new model of elementary particles based on the geometry of Quantum deSitter space QdS = SU (3,2)/(SU(3,1) x U(1)) is introduced and studied. QdS is a complexification of quantization of anti-de Sitter space, AdS = SO(3,2)/SO(3,1), which in recent years had played a pivotal role in supergravity. The nontrival principle fiber bundle has total space SU(3,2), fiber SU(3,1) x U(1) and base QdS. In this setting, the standard recipes for Yang-Mills fields don't work. These require connections and the associated covariant derivatives. Here it is shown that the Lie derivatives, not the covariant derivatives are important in quantization. In this setting, the no-go theorems are not valid. This new quantum mechanics leads to a model of elementary particles as vertical vector fields in the bundle with interaction via the Lie bracket. There are five physical interactions modelled by the bracket interaction. The quantum numbers are identified as the roots of su(3,2) and are preserved under the bracket interaction. The model explains conservation of charge, baryon number, lepton number, parity and the heirarchy problem. Since the bracket is the curvature of a homogeneous space, particles are then the curvature of QdS. This model for particles is consistent with the requirements of General Relativity. Furthermore, since the curvature tensor is built from the quantized wave functions, the curvature tensor is quantized and this is quantum theory of gravity
Geometry and physics of branes
International Nuclear Information System (INIS)
Gal'tsov, D V
2003-01-01
The book brings together the contents of lecture courses delivered at the school 'Geometry and Physics of Branes' which took place at the Center 'Alessandro Volta' (Como, Italy) in the spring of 2001. The purpose of the school was to provide an introduction to some lines of research, related to the notion of branes in superstring theory, which are in the focus of attention both in the physical and mathematical communities. The book is structured into three parts: the first contains an elementary introduction to branes, the second is devoted to physical aspects (conformal field theory on open and unoriented surfaces and topics in string tachyon dynamics), and the last contains some more formal mathematical developments. An introduction to branes is given in a remarkably lucid contribution by A Lerda. It opens with a construction of p-brane solutions in classical IIA and IIB supergravities with particular emphasis on the 'fundamental string' solution, the NS5-brane and the D3-brane. Then, the quantum description of D-branes is discussed in terms of boundary states of the closed superstring, which is an alternative to the more common description in terms of open strings with Dirichlet boundary conditions in the transverse to the brane directions. When a constant gauge field is present in the D-brane worldvolume, the boundary states are coherent states of the string oscillators depending on the field strength tensor. The couplings of the brane to the bulk fields - the graviton, the dilaton, and the Kalb-Ramond fields - are then extracted and shown to be precisely the ones that are produced by the Dirac-Born-Infeld action governing the low-energy dynamics of the D-brane derived using the open strings formalism. It is also shown that in the classical limit, the boundary states correctly reproduce the parameters of the corresponding classical solutions. The second part of the book starts with a contribution by Y S Stanev devoted to the two-dimensional conformal field
Description of SSG Geometry - phase 1
DEFF Research Database (Denmark)
Margheritini, Lucia; Kofoed, Jens Peter
The purpose of the study is to define the optimized geometry for the SSG in Svaheia, Norway and to provide the responsible for the turbines with useful information to their work.......The purpose of the study is to define the optimized geometry for the SSG in Svaheia, Norway and to provide the responsible for the turbines with useful information to their work....
Increasing insightful thinking in analytic geometry
Timmer, Mark; Verhoef, Neeltje Cornelia
Elsewhere in this issue Ferdinand Verhulst described the discussion of the interaction of analysis and geometry in the 19th century. In modern times such discussions come up again and again. As of 2014, synthetic geometry will not be part of the Dutch 'vwo - mathematics B' programme anymore.
Symposium on Differential Geometry and Differential Equations
Berger, Marcel; Bryant, Robert
1987-01-01
The DD6 Symposium was, like its predecessors DD1 to DD5 both a research symposium and a summer seminar and concentrated on differential geometry. This volume contains a selection of the invited papers and some additional contributions. They cover recent advances and principal trends in current research in differential geometry.
Curvature tensor copies in affine geometry
International Nuclear Information System (INIS)
Srivastava, P.P.
1981-01-01
The sets of space-time and spin-connections which give rise to the same curvature tensor are constructed. The corresponding geometries are compared. Results are illustrated by an explicit calculation and comment on the copies in Einstein-Cartan and Weyl-Cartan geometries. (Author) [pt
Fractal geometry of high temperature superconductors
International Nuclear Information System (INIS)
Mosolov, A.B.
1989-01-01
Microstructural geometry of superconducting structural composites of Ag-Yba 2 Cu 3 O x system with a volumetric shave of silver from 0 to 60% is investigated by light and electron microscopy methods. It is ascertained that the structure of cermets investigated is characterized by fractal geometry which is sufficient for describing the electrical and mechanical properties of these materials
Quantification of variability in bedform geometry
van der Mark, C.F.; Blom, Astrid; Hulscher, Suzanne J.M.H.
2008-01-01
We analyze the variability in bedform geometry in laboratory and field studies. Even under controlled steady flow conditions in laboratory flumes, bedforms are irregular in size, shape, and spacing, also in case of well-sorted sediment. Our purpose is to quantify the variability in bedform geometry.
Random geometry and Yang-Mills theory
International Nuclear Information System (INIS)
Froehlich, J.
1981-01-01
The author states various problems and discusses a very few preliminary rigorous results in a branch of mathematics and mathematical physics which one might call random (or stochastic) geometry. Furthermore, he points out why random geometry is important in the quantization of Yang-Mills theory. (Auth.)
The Geometry of the Universe: Part 2
Francis, Stephanie
2009-01-01
Hyperbolic geometry occurs on hyperbolic planes--the most commonly cited one being a saddle shape. In this article, the author explores negative hyperbolic curvature, and provides a detailed description of how she constructed two hyperbolic paraboloids. Hyperbolic geometry occurs on surfaces that have negative curvature. (Contains 11 figures and 4…
Poisson geometry from a Dirac perspective
Meinrenken, Eckhard
2018-03-01
We present proofs of classical results in Poisson geometry using techniques from Dirac geometry. This article is based on mini-courses at the Poisson summer school in Geneva, June 2016, and at the workshop Quantum Groups and Gravity at the University of Waterloo, April 2016.
An approach for management of geometry data
Dube, R. P.; Herron, G. J.; Schweitzer, J. E.; Warkentine, E. R.
1980-01-01
The strategies for managing Integrated Programs for Aerospace Design (IPAD) computer-based geometry are described. The computer model of geometry is the basis for communication, manipulation, and analysis of shape information. IPAD's data base system makes this information available to all authorized departments in a company. A discussion of the data structures and algorithms required to support geometry in IPIP (IPAD's data base management system) is presented. Through the use of IPIP's data definition language, the structure of the geometry components is defined. The data manipulation language is the vehicle by which a user defines an instance of the geometry. The manipulation language also allows a user to edit, query, and manage the geometry. The selection of canonical forms is a very important part of the IPAD geometry. IPAD has a canonical form for each entity and provides transformations to alternate forms; in particular, IPAD will provide a transformation to the ANSI standard. The DBMS schemas required to support IPAD geometry are explained.
Transformasi Geometri Rotasi Berbantuan Software Geogebra
Directory of Open Access Journals (Sweden)
Muhamad Hanafi
2018-02-01
Full Text Available Penelitian ini bertujuan untuk membantu visualisasi dan menemukan konsep pada Transformasi geometri Rotasi di titik Pusat dengan menggunakan software GeoGebra. Penelitian ini mengulas tentang Koordinat Kartesius dan Polar, dan selanjutntya Transformasi geometri Rotasi di titik Pusat .
Muhassanah, Nuraini; Sujadi, Imam; Riyadi, Riyadi
2014-01-01
The objective of this research was to describe the VIII grade students geometry skills atSMP N 16 Surakarta in the level 0 (visualization), level 1 (analysis), and level 2 (informaldeduction) van Hiele level of thinking in solving the geometry problem. This research was aqualitative research in the form of case study analyzing deeply the students geometry skill insolving the geometry problem based on van Hiele level of thingking. The subject of this researchwas nine students of VIII grade at ...
The design of geometry teaching: learning from the geometry textbooks of Godfrey and Siddons
Fujita, Taro; Jones, Keith
2002-01-01
Deciding how to teach geometry remains a demanding task with one of major arguments being about how to combine the intuitive and deductive aspects of geometry into an effective teaching design. In order to try to obtain an insight into tackling this issue, this paper reports an analysis of innovative geometry textbooks which were published in the early part of the 20th Century, a time when significant efforts were being made to improve the teaching and learning of geometry. The analysis sugge...
International Nuclear Information System (INIS)
Weissman, S.D.
1989-01-01
The foot may be thought of as a bag of bones tied tightly together and functioning as a unit. The bones re expected to maintain their alignment without causing symptomatology to the patient. The author discusses a normal radiograph. The bones must have normal shape and normal alignment. The density of the soft tissues should be normal and there should be no fractures, tumors, or foreign bodies
International Nuclear Information System (INIS)
Falkenberg, G.; Pepponi, G.; Streli, C.; Wobrauschek, P.
2003-01-01
X-ray absorption fine structure (XAFS) experiments in fluorescence mode have been performed in total reflection excitation geometry and conventional 45 deg. /45 deg. excitation/detection geometry for comparison. The experimental results have shown that XAFS measurements are feasible under normal total reflection X-ray fluorescence (TXRF) conditions, i.e. on droplet samples, with excitation in grazing incidence and using a TXRF experimental chamber. The application of the total reflection excitation geometry for XAFS measurements increases the sensitivity compared to the conventional geometry leading to lower accessible concentration ranges. However, XAFS under total reflection excitation condition fails for highly concentrated samples because of the self-absorption effect
Physical meaning of the optical reference geometry
International Nuclear Information System (INIS)
Abramowicz, M.A.
1990-09-01
I show that contrary to a popular misconception the optical reference geometry, introduced a few years ago as a formally possible metric of a 3-space corresponding to a static spacetime, is quite satisfactory also from the physical point of view. The optical reference geometry has a clear physical meaning, as it may be constructed experimentally by measuring light round travel time between static observers. Distances and directions in the optical reference geometry are more strongly connected to experiment than distances and directions in the widely used directly projected metric (discussed e.g. in Landau and Lifshitz textbook. In addition, the optical reference geometry is more natural and convenient than the directly projected one in application to dynamics. In the optical geometry dynamical behaviour of matter is described by concepts and formulae identical to those well known in Newtonian dynamics on a given two dimensional (curved) surface. (author). 22 refs
FINAL REPORT: GEOMETRY AND ELEMENTARY PARTICLE PHYSICS
Energy Technology Data Exchange (ETDEWEB)
Singer, Isadore M.
2008-03-04
The effect on mathematics of collaborations between high-energy theoretical physics and modern mathematics has been remarkable. Mirror symmetry has revolutionized enumerative geometry, and Seiberg-Witten invariants have greatly simplified the study of four manifolds. And because of their application to string theory, physicists now need to know cohomology theory, characteristic classes, index theory, K-theory, algebraic geometry, differential geometry, and non-commutative geometry. Much more is coming. We are experiencing a deeper contact between the two sciences, which will stimulate new mathematics essential to the physicists’ quest for the unification of quantum mechanics and relativity. Our grant, supported by the Department of Energy for twelve years, has been instrumental in promoting an effective interaction between geometry and string theory, by supporting the Mathematical Physics seminar, postdoc research, collaborations, graduate students and several research papers.
Machine learning spatial geometry from entanglement features
You, Yi-Zhuang; Yang, Zhao; Qi, Xiao-Liang
2018-02-01
Motivated by the close relations of the renormalization group with both the holography duality and the deep learning, we propose that the holographic geometry can emerge from deep learning the entanglement feature of a quantum many-body state. We develop a concrete algorithm, call the entanglement feature learning (EFL), based on the random tensor network (RTN) model for the tensor network holography. We show that each RTN can be mapped to a Boltzmann machine, trained by the entanglement entropies over all subregions of a given quantum many-body state. The goal is to construct the optimal RTN that best reproduce the entanglement feature. The RTN geometry can then be interpreted as the emergent holographic geometry. We demonstrate the EFL algorithm on a 1D free fermion system and observe the emergence of the hyperbolic geometry (AdS3 spatial geometry) as we tune the fermion system towards the gapless critical point (CFT2 point).
Final Report: Geometry And Elementary Particle Physics
International Nuclear Information System (INIS)
Singer, Isadore M.
2008-01-01
The effect on mathematics of collaborations between high-energy theoretical physics and modern mathematics has been remarkable. Mirror symmetry has revolutionized enumerative geometry, and Seiberg-Witten invariants have greatly simplified the study of four manifolds. And because of their application to string theory, physicists now need to know cohomology theory, characteristic classes, index theory, K-theory, algebraic geometry, differential geometry, and non-commutative geometry. Much more is coming. We are experiencing a deeper contact between the two sciences, which will stimulate new mathematics essential to the physicists quest for the unification of quantum mechanics and relativity. Our grant, supported by the Department of Energy for twelve years, has been instrumental in promoting an effective interaction between geometry and string theory, by supporting the Mathematical Physics seminar, postdoc research, collaborations, graduate students and several research papers.
Special metrics and group actions in geometry
Fino, Anna; Musso, Emilio; Podestà, Fabio; Vezzoni, Luigi
2017-01-01
The volume is a follow-up to the INdAM meeting “Special metrics and quaternionic geometry” held in Rome in November 2015. It offers a panoramic view of a selection of cutting-edge topics in differential geometry, including 4-manifolds, quaternionic and octonionic geometry, twistor spaces, harmonic maps, spinors, complex and conformal geometry, homogeneous spaces and nilmanifolds, special geometries in dimensions 5–8, gauge theory, symplectic and toric manifolds, exceptional holonomy and integrable systems. The workshop was held in honor of Simon Salamon, a leading international scholar at the forefront of academic research who has made significant contributions to all these subjects. The articles published here represent a compelling testimony to Salamon’s profound and longstanding impact on the mathematical community. Target readership includes graduate students and researchers working in Riemannian and complex geometry, Lie theory and mathematical physics.
Directory of Open Access Journals (Sweden)
Allansdotter-Johnsson Ase
2009-01-01
Full Text Available Abstract Background Knowledge about age-specific normal values for left ventricular mass (LVM, end-diastolic volume (EDV, end-systolic volume (ESV, stroke volume (SV and ejection fraction (EF by cardiac magnetic resonance imaging (CMR is of importance to differentiate between health and disease and to assess the severity of disease. The aims of the study were to determine age and gender specific normal reference values and to explore the normal physiological variation of these parameters from adolescence to late adulthood, in a cross sectional study. Methods Gradient echo CMR was performed at 1.5 T in 96 healthy volunteers (11–81 years, 50 male. Gender-specific analysis of parameters was undertaken in both absolute values and adjusted for body surface area (BSA. Results Age and gender specific normal ranges for LV volumes, mass and function are presented from the second through the eighth decade of life. LVM, ESV and EDV rose during adolescence and declined in adulthood. SV and EF decreased with age. Compared to adult females, adult males had higher BSA-adjusted values of EDV (p = 0.006 and ESV (p Conclusion LV volumes, mass and function vary over a broad age range in healthy individuals. LV volumes and mass both rise in adolescence and decline with age. EF showed a rapid decline in adolescence compared to changes throughout adulthood. These findings demonstrate the need for age and gender specific normal ranges for clinical use.
A study of complexity of oral mucosa using fractal geometry
Directory of Open Access Journals (Sweden)
S R Shenoi
2017-01-01
Full Text Available Background: The oral mucosa lining the oral cavity is composed of epithelium supported by connective tissue. The shape of the epithelial-connective tissue interface has traditionally been used to describe physiological and pathological changes in the oral mucosa. Aim: The aim is to evaluate the morphometric complexity in normal, dysplastic, well-differentiated, and moderately differentiated squamous cell carcinoma (SCC of the oral mucosa using fractal geometry. Materials and Methods: A total of 80 periodic acid–Schiff stained histological images of four groups: normal mucosa, dysplasia, well-differentiated SCC, and moderately differentiated SCC were verified by the gold standard. These images were then subjected to fractal analysis. Statistical Analysis: ANOVA and post hoc test: Bonferroni was applied. Results: Fractal dimension (FD increases as the complexity increases from normal to dysplasia and then to SCC. Normal buccal mucosa was found to be significantly different from dysplasia and the two grades of SCC (P < 0.05. ANOVA of fractal scores of four morphometrically different groups of buccal mucosa was significantly different with F (3,76 = 23.720 and P< 0.01. However, FD of dysplasia was not significantly different from well-differentiated and moderately differentiated SCC (P = 1.000 and P = 0.382, respectively. Conclusion: This study establishes FD as a newer tool in differentiating normal tissue from dysplastic and neoplastic tissue. Fractal geometry is useful in the study of both physiological and pathological changes in the oral mucosa. A new grading system based on FD may emerge as an adjuvant aid in cancer diagnosis.
Analogy and Dynamic Geometry System Used to Introduce Three-Dimensional Geometry
Mammana, M. F.; Micale, B.; Pennisi, M.
2012-01-01
We present a sequence of classroom activities on Euclidean geometry, both plane and space geometry, used to make three dimensional geometry more catchy and simple. The activity consists of a guided research activity that leads the students to discover unexpected properties of two apparently distant geometrical entities, quadrilaterals and…
Drawing Dynamic Geometry Figures Online with Natural Language for Junior High School Geometry
Wong, Wing-Kwong; Yin, Sheng-Kai; Yang, Chang-Zhe
2012-01-01
This paper presents a tool for drawing dynamic geometric figures by understanding the texts of geometry problems. With the tool, teachers and students can construct dynamic geometric figures on a web page by inputting a geometry problem in natural language. First we need to build the knowledge base for understanding geometry problems. With the…
Fuzzy Geometry of Commutative Spaces and Quantum Dynamics
International Nuclear Information System (INIS)
Mayburov, S.N.
2016-01-01
Fuzzy topology and geometry considered as the possible mathematical framework for novel quantum-mechanical formalism. In such formalism the states of massive particle m correspond to the elements of fuzzy manifold called fuzzy points. Due to the manifold weak topology, m space coordinate x acquires principal uncertainty σ_x and described by the positive, normalized density w(r-vector , t) in 3-dimensional case. It’s shown that the evolution of m state on such 3-dimensional manifold corresponds to Shroedinger dynamics of massive quantum particle
Primes, Geometry and Condensed Matter
Directory of Open Access Journals (Sweden)
Al Rabeh R. H.
2009-07-01
Full Text Available Fascination with primes dates back to the Greeks and before. Primes are named by some "the elementary particles of arithmetic" as every nonprime integer is made of a unique set of primes. In this article we point to new connections between primes, geometry and physics which show that primes could be called "the elementary particles of physics" too. This study considers the problem of closely packing similar circles/spheres in 2D/3D space. This is in effect a discretization process of space and the allowable number in a pack is found to lead to some unexpected cases of prime configurations which is independent of the size of the constituents. We next suggest that a non-prime can be considered geometrically as a symmetric collection that is separable (factorable into similar parts- six is two threes or three twos for example. A collection that has no such symmetry is a prime. As a result, a physical prime aggregate is more difficult to split symmetrically resulting in an inherent stability. This "number/physical" stability idea applies to bigger collections made from smaller (prime units leading to larger stable prime structures in a limitless scaling up process. The distribution of primes among numbers can be understood better using the packing ideas described here and we further suggest that differing numbers (and values of distinct prime factors making a nonprime collection is an important factor in determining the probability and method of possible and subsequent disintegration. Disintegration is bound by energy conservation and is closely related to symmetry by Noether theorems. Thinking of condensed matter as the packing of identical elements, we examine plots of the masses of chemical elements of the periodic table, and also those of the elementary particles of physics, and show that prime packing rules seem to play a role in the make up of matter. The plots show convincingly that the growth of prime numbers and that of the masses of
Primes, Geometry and Condensed Matter
Directory of Open Access Journals (Sweden)
Al Rabeh R. H.
2009-07-01
Full Text Available Fascination with primes dates back to the Greeks and before. Primes are named by some “the elementary particles of arithmetic” as every nonprime integer is made of a unique set of primes. In this article we point to new connections between primes, geometry and physics which show that primes could be called “the elementary particles of physics” too. This study considers the problem of closely packing similar circles / spheres in 2D / 3D space. This is in effect a discretization process of space and the allowable num- ber in a pack is found to lead to some unexpected cases of prime configurations which is independent of the size of the constituents. We next suggest that a non-prime can be considered geometrically as a symmetric collection that is separable (factorable into similar parts- six is two threes or three twos for example. A collection that has no such symmetry is a prime. As a result, a physical prime aggregate is more difficult to split symmetrically resulting in an inherent stability. This “number / physical” stability idea applies to bigger collections made from smaller (prime units leading to larger sta- ble prime structures in a limitless scaling up process. The distribution of primes among numbers can be understood better using the packing ideas described here and we further suggest that differing numbers (and values of distinct prime factors making a nonprime collection is an important factor in determining the probability and method of possible and subsequent disintegration. Disintegration is bound by energy conservation and is closely related to symmetry by Noether theorems. Thinking of condensed matter as the packing of identical elements, we examine plots of the masses of chemical elements of the periodic table, and also those of the elementary particles of physics, and show that prime packing rules seem to play a role in the make up of matter. The plots show con- vincingly that the growth of prime numbers and that
Geometry of Gaussian quantum states
International Nuclear Information System (INIS)
Link, Valentin; Strunz, Walter T
2015-01-01
We study the Hilbert–Schmidt measure on the manifold of mixed Gaussian states in multi-mode continuous variable quantum systems. An analytical expression for the Hilbert–Schmidt volume element is derived. Its corresponding probability measure can be used to study typical properties of Gaussian states. It turns out that although the manifold of Gaussian states is unbounded, an ensemble of Gaussian states distributed according to this measure still has a normalizable distribution of symplectic eigenvalues, from which unitarily invariant properties can be obtained. By contrast, we find that for an ensemble of one-mode Gaussian states based on the Bures measure the corresponding distribution cannot be normalized. As important applications, we determine the distribution and the mean value of von Neumann entropy and purity for the Hilbert–Schmidt measure. (paper)
Geometry and physics of branes
Energy Technology Data Exchange (ETDEWEB)
Gal' tsov, D V
2003-03-21
The book brings together the contents of lecture courses delivered at the school 'Geometry and Physics of Branes' which took place at the Center 'Alessandro Volta' (Como, Italy) in the spring of 2001. The purpose of the school was to provide an introduction to some lines of research, related to the notion of branes in superstring theory, which are in the focus of attention both in the physical and mathematical communities. The book is structured into three parts: the first contains an elementary introduction to branes, the second is devoted to physical aspects (conformal field theory on open and unoriented surfaces and topics in string tachyon dynamics), and the last contains some more formal mathematical developments. An introduction to branes is given in a remarkably lucid contribution by A Lerda. It opens with a construction of p-brane solutions in classical IIA and IIB supergravities with particular emphasis on the 'fundamental string' solution, the NS5-brane and the D3-brane. Then, the quantum description of D-branes is discussed in terms of boundary states of the closed superstring, which is an alternative to the more common description in terms of open strings with Dirichlet boundary conditions in the transverse to the brane directions. When a constant gauge field is present in the D-brane worldvolume, the boundary states are coherent states of the string oscillators depending on the field strength tensor. The couplings of the brane to the bulk fields - the graviton, the dilaton, and the Kalb-Ramond fields - are then extracted and shown to be precisely the ones that are produced by the Dirac-Born-Infeld action governing the low-energy dynamics of the D-brane derived using the open strings formalism. It is also shown that in the classical limit, the boundary states correctly reproduce the parameters of the corresponding classical solutions. The second part of the book starts with a contribution by Y S Stanev devoted to the two
Steady three-fluid coronal expansion for nonspherical geometries
International Nuclear Information System (INIS)
Joselyn, J.; Holzer, T.E.
1978-01-01
A steady three-fluid model of the solar coronal expansionk in which 4 He ++ ions (alphas) are treated as a nonminor species, is developed for nonspherically symmetric flow geometries of the general sort thought to be characteristic of coronal holes. It is found that the very high mass fluxes in the low corona, which are associated with rapidly diverging flow geometries, lead to a locally enhanced frictional coupling between protons and alphas and consequently to a significant reduction of the He/H abundance ratio in the lower corona from that normally predicted by multifluid models. In the models considered, the frictional drag on the protons by the alphas (a process neglected in most studies) is found to play an important role near the sun. Heavy ions, other than alphas, are treated as minor species and are seen to exhibit varying responses to the rapidly diverging flow geometries, depending on the ion mass and charge. As for the protons, the frictional effect of the alphas on the heavier ions is found to be significant in the models considered
Quantification of Porcine Vocal Fold Geometry.
Stevens, Kimberly A; Thomson, Scott L; Jetté, Marie E; Thibeault, Susan L
2016-07-01
The aim of this study was to quantify porcine vocal fold medial surface geometry and three-dimensional geometric distortion induced by freezing the larynx, especially in the region of the vocal folds. The medial surface geometries of five excised porcine larynges were quantified and reported. Five porcine larynges were imaged in a micro-CT scanner, frozen, and rescanned. Segmentations and three-dimensional reconstructions were used to quantify and characterize geometric features. Comparisons were made with geometry data previously obtained using canine and human vocal folds as well as geometries of selected synthetic vocal fold models. Freezing induced an overall expansion of approximately 5% in the transverse plane and comparable levels of nonuniform distortion in sagittal and coronal planes. The medial surface of the porcine vocal folds was found to compare reasonably well with other geometries, although the compared geometries exhibited a notable discrepancy with one set of published human female vocal fold geometry. Porcine vocal folds are qualitatively geometrically similar to data available for canine and human vocal folds, as well as commonly used models. Freezing of tissue in the larynx causes distortion of around 5%. The data can provide direction in estimating uncertainty due to bulk distortion of tissue caused by freezing, as well as quantitative geometric data that can be directly used in developing vocal fold models. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.
Discrete quantum geometries and their effective dimension
International Nuclear Information System (INIS)
Thuerigen, Johannes
2015-01-01
In several approaches towards a quantum theory of gravity, such as group field theory and loop quantum gravity, quantum states and histories of the geometric degrees of freedom turn out to be based on discrete spacetime. The most pressing issue is then how the smooth geometries of general relativity, expressed in terms of suitable geometric observables, arise from such discrete quantum geometries in some semiclassical and continuum limit. In this thesis I tackle the question of suitable observables focusing on the effective dimension of discrete quantum geometries. For this purpose I give a purely combinatorial description of the discrete structures which these geometries have support on. As a side topic, this allows to present an extension of group field theory to cover the combinatorially larger kinematical state space of loop quantum gravity. Moreover, I introduce a discrete calculus for fields on such fundamentally discrete geometries with a particular focus on the Laplacian. This permits to define the effective-dimension observables for quantum geometries. Analysing various classes of quantum geometries, I find as a general result that the spectral dimension is more sensitive to the underlying combinatorial structure than to the details of the additional geometric data thereon. Semiclassical states in loop quantum gravity approximate the classical geometries they are peaking on rather well and there are no indications for stronger quantum effects. On the other hand, in the context of a more general model of states which are superposition over a large number of complexes, based on analytic solutions, there is a flow of the spectral dimension from the topological dimension d on low energy scales to a real number between 0 and d on high energy scales. In the particular case of 1 these results allow to understand the quantum geometry as effectively fractal.
A Gyrovector Space Approach to Hyperbolic Geometry
Ungar, Abraham
2009-01-01
The mere mention of hyperbolic geometry is enough to strike fear in the heart of the undergraduate mathematics and physics student. Some regard themselves as excluded from the profound insights of hyperbolic geometry so that this enormous portion of human achievement is a closed door to them. The mission of this book is to open that door by making the hyperbolic geometry of Bolyai and Lobachevsky, as well as the special relativity theory of Einstein that it regulates, accessible to a wider audience in terms of novel analogies that the modern and unknown share with the classical and familiar. T
SABRINA, Geometry Plot Program for MCNP
International Nuclear Information System (INIS)
SEIDL, Marcus
2003-01-01
1 - Description of program or function: SABRINA is an interactive, three-dimensional, geometry-modeling code system, primarily for use with CCC-200/MCNP. SABRINA's capabilities include creation, visualization, and verification of three-dimensional geometries specified by either surface- or body-base combinatorial geometry; display of particle tracks are calculated by MCNP; and volume fraction generation. 2 - Method of solution: Rendering is performed by ray tracing or an edge and intersection algorithm. Volume fraction calculations are made by ray tracing. 3 - Restrictions on the complexity of the problem: A graphics display with X Window capability is required
Information geometry near randomness and near independence
Arwini, Khadiga A
2008-01-01
This volume will be useful to practising scientists and students working in the application of statistical models to real materials or to processes with perturbations of a Poisson process, a uniform process, or a state of independence for a bivariate process. We use information geometry to provide a common differential geometric framework for a wide range of illustrative applications including amino acid sequence spacings in protein chains, cryptology studies, clustering of communications and galaxies, cosmological voids, coupled spatial statistics in stochastic fibre networks and stochastic porous media, quantum chaology. Introduction sections are provided to mathematical statistics, differential geometry and the information geometry of spaces of probability density functions.
Introduction into integral geometry and stereology
DEFF Research Database (Denmark)
Kiderlen, Markus
Statistics and Random Fields and is a self-containing introduction into integral geometry and its applications in stereology. The most important integral geometric tools for stereological applications are kinematic formulas and results of Blaschke-Petkantschin type. Therefore, Crofton's formula......This text is the extended version of two talks held at the Summer Academy Stochastic Geometry, Spatial Statistics and Random Fields in the Soellerhaus, Germany, in September 2009. It forms (with slight modifications) a chapter of the Springer lecture notes Lectures on Stochastic Geometry, Spatial...
Differential geometry and topology of curves
Animov, Yu
2001-01-01
Differential geometry is an actively developing area of modern mathematics. This volume presents a classical approach to the general topics of the geometry of curves, including the theory of curves in n-dimensional Euclidean space. The author investigates problems for special classes of curves and gives the working method used to obtain the conditions for closed polygonal curves. The proof of the Bakel-Werner theorem in conditions of boundedness for curves with periodic curvature and torsion is also presented. This volume also highlights the contributions made by great geometers. past and present, to differential geometry and the topology of curves.
Digital and discrete geometry theory and algorithms
Chen, Li
2014-01-01
This book provides comprehensive coverage of the modern methods for geometric problems in the computing sciences. It also covers concurrent topics in data sciences including geometric processing, manifold learning, Google search, cloud data, and R-tree for wireless networks and BigData.The author investigates digital geometry and its related constructive methods in discrete geometry, offering detailed methods and algorithms. The book is divided into five sections: basic geometry; digital curves, surfaces and manifolds; discretely represented objects; geometric computation and processing; and a
Fractal geometry mathematical foundations and applications
Falconer, Kenneth
2013-01-01
The seminal text on fractal geometry for students and researchers: extensively revised and updated with new material, notes and references that reflect recent directions. Interest in fractal geometry continues to grow rapidly, both as a subject that is fascinating in its own right and as a concept that is central to many areas of mathematics, science and scientific research. Since its initial publication in 1990 Fractal Geometry: Mathematical Foundations and Applications has become a seminal text on the mathematics of fractals. The book introduces and develops the general theory and applica
Fault geometry and earthquake mechanics
Directory of Open Access Journals (Sweden)
D. J. Andrews
1994-06-01
Full Text Available Earthquake mechanics may be determined by the geometry of a fault system. Slip on a fractal branching fault surface can explain: 1 regeneration of stress irregularities in an earthquake; 2 the concentration of stress drop in an earthquake into asperities; 3 starting and stopping of earthquake slip at fault junctions, and 4 self-similar scaling of earthquakes. Slip at fault junctions provides a natural realization of barrier and asperity models without appealing to variations of fault strength. Fault systems are observed to have a branching fractal structure, and slip may occur at many fault junctions in an earthquake. Consider the mechanics of slip at one fault junction. In order to avoid a stress singularity of order 1/r, an intersection of faults must be a triple junction and the Burgers vectors on the three fault segments at the junction must sum to zero. In other words, to lowest order the deformation consists of rigid block displacement, which ensures that the local stress due to the dislocations is zero. The elastic dislocation solution, however, ignores the fact that the configuration of the blocks changes at the scale of the displacement. A volume change occurs at the junction; either a void opens or intense local deformation is required to avoid material overlap. The volume change is proportional to the product of the slip increment and the total slip since the formation of the junction. Energy absorbed at the junction, equal to confining pressure times the volume change, is not large enongh to prevent slip at a new junction. The ratio of energy absorbed at a new junction to elastic energy released in an earthquake is no larger than P/µ where P is confining pressure and µ is the shear modulus. At a depth of 10 km this dimensionless ratio has th value P/µ= 0.01. As slip accumulates at a fault junction in a number of earthquakes, the fault segments are displaced such that they no longer meet at a single point. For this reason the
Compensation strategies for PET scanners with unconventional scanner geometry
Gundlich, B; Oehler, M
2006-01-01
The small animal PET scanner ClearPET®Neuro, developed at the Forschungszentrum Julich GmbH in cooperation with the Crystal Clear Collaboration (CERN), represents scanners with an unconventional geometry: due to axial and transaxial detector gaps ClearPet®Neuro delivers inhomogeneous sinograms with missing data. When filtered backprojection (FBP) or Fourier rebinning (FORE) are applied, strong geometrical artifacts appear in the images. In this contribution we present a method that takes the geometrical sensitivity into account and converts the measured sinograms into homogeneous and complete data. By this means artifactfree images are achieved using FBP or FORE. Besides an advantageous measurement setup that reduces inhomogeneities and data gaps in the sinograms, a modification of the measured sinograms is necessary. This modification includes two steps: a geometrical normalization and corrections for missing data. To normalize the measured sinograms, computed sinograms are used that describe the geometric...
International Nuclear Information System (INIS)
Sandoval V, S.; Mendoza R, M. E.; Tijerina S, F.; Garcia C, T.
2016-09-01
A nuclear power plant is operated at all times within the design criteria of structures, systems and components, and according to the operation technical specifications. For different areas of work of a nuclear power plant is necessary to carry out practices in which is useful to have the prediction of the thermo-hydraulic and radiological progression of scenarios that imply exceeding that design bases, even reaching the damage of the fuel in different degree. During the exercises and drills of the External Plan of Emergency Response, the projection of doses is done to exercise the different tasks of the plan. To make the projection of doses is required to have the radiological source term of the scenario on which is practiced. Because of this, was identified the convenience of having a catalog of scenarios for which the radiological source term was calculated. In 2004, a first version of the catalog was produced for a power of 2027 MW, and in 2011 the catalog was updated for extended power conditions, 2317 MW. Both versions were made using the severe accident simulator MAAP-3B. That catalog consists of a form and an optical storage device. The form contains tables and figures in which the characteristics of the scenario to be practiced are searched and the electronic files of the corresponding radiological source term are located in the storage device. Due to the recent development of the graphical console for analysis of severe accidents, visualization of OEs, NAEs and calculation of the source term for the nuclear power plant of Laguna Verde (NPP-LV) CoGrAAS, the catalog printed was replaced by an electronic catalog for the CoGrAAS. The new catalog retains the philosophy of the previous catalog, constituted by a wide collection of scenarios that involve different circumstances and phenomena, that can be used to practice different tasks during training exercises or simulacrums, and combined with the following advantages: the scenario selection is made from an
MONTE CARLO ANALYSES OF THE YALINA THERMAL FACILITY WITH SERPENT STEREOLITHOGRAPHY GEOMETRY MODEL
Energy Technology Data Exchange (ETDEWEB)
Talamo, A.; Gohar, Y.
2015-01-01
This paper analyzes the YALINA Thermal subcritical assembly of Belarus using two different Monte Carlo transport programs, SERPENT and MCNP. The MCNP model is based on combinatorial geometry and universes hierarchy, while the SERPENT model is based on Stereolithography geometry. The latter consists of unstructured triangulated surfaces defined by the normal and vertices. This geometry format is used by 3D printers and it has been created by: the CUBIT software, MATLAB scripts, and C coding. All the Monte Carlo simulations have been performed using the ENDF/B-VII.0 nuclear data library. Both MCNP and SERPENT share the same geometry specifications, which describe the facility details without using any material homogenization. Three different configurations have been studied with different number of fuel rods. The three fuel configurations use 216, 245, or 280 fuel rods, respectively. The numerical simulations show that the agreement between SERPENT and MCNP results is within few tens of pcms.
Energy Technology Data Exchange (ETDEWEB)
Wu Hongchun [Nuclear Engineering Department, Xi' an Jiaotong University, Xi' an 710049, Shaanxi (China)]. E-mail: hongchun@mail.xjtu.edu.cn; Liu Pingping [Nuclear Engineering Department, Xi' an Jiaotong University, Xi' an 710049, Shaanxi (China); Zhou Yongqiang [Nuclear Engineering Department, Xi' an Jiaotong University, Xi' an 710049, Shaanxi (China); Cao Liangzhi [Nuclear Engineering Department, Xi' an Jiaotong University, Xi' an 710049, Shaanxi (China)
2007-01-15
In the advanced reactor, the fuel assembly or core with unstructured geometry is frequently used and for calculating its fuel assembly, the transmission probability method (TPM) has been used widely. However, the rectangle or hexagon meshes are mainly used in the TPM codes for the normal core structure. The triangle meshes are most useful for expressing the complicated unstructured geometry. Even though finite element method and Monte Carlo method is very good at solving unstructured geometry problem, they are very time consuming. So we developed the TPM code based on the triangle meshes. The TPM code based on the triangle meshes was applied to the hybrid fuel geometry, and compared with the results of the MCNP code and other codes. The results of comparison were consistent with each other. The TPM with triangle meshes would thus be expected to be able to apply to the two-dimensional arbitrary fuel assembly.
Novel 3D Compression Methods for Geometry, Connectivity and Texture
Siddeq, M. M.; Rodrigues, M. A.
2016-06-01
A large number of applications in medical visualization, games, engineering design, entertainment, heritage, e-commerce and so on require the transmission of 3D models over the Internet or over local networks. 3D data compression is an important requirement for fast data storage, access and transmission within bandwidth limitations. The Wavefront OBJ (object) file format is commonly used to share models due to its clear simple design. Normally each OBJ file contains a large amount of data (e.g. vertices and triangulated faces, normals, texture coordinates and other parameters) describing the mesh surface. In this paper we introduce a new method to compress geometry, connectivity and texture coordinates by a novel Geometry Minimization Algorithm (GM-Algorithm) in connection with arithmetic coding. First, each vertex ( x, y, z) coordinates are encoded to a single value by the GM-Algorithm. Second, triangle faces are encoded by computing the differences between two adjacent vertex locations, which are compressed by arithmetic coding together with texture coordinates. We demonstrate the method on large data sets achieving compression ratios between 87 and 99 % without reduction in the number of reconstructed vertices and triangle faces. The decompression step is based on a Parallel Fast Matching Search Algorithm (Parallel-FMS) to recover the structure of the 3D mesh. A comparative analysis of compression ratios is provided with a number of commonly used 3D file formats such as VRML, OpenCTM and STL highlighting the performance and effectiveness of the proposed method.
Yamashita, H; Onodera, S; Imamoto, T; Obara, A; Tanazawa, S; Takashio, T; Morimoto, H; Inoue, H
1989-10-01
To clarify the effects of right ventricular (RV) pressure overload on functional and geometrical interference and interdependency between the right and left ventricle, both ventricular internal diameters were measured by the microcrystal technique during lycopodium induced pulmonary embolization in the dog. By repeated embolization, RV systolic pressure was increased progressively until it reached a peak value of about 60-70 mmHg, then it began to fall. At the same time, the hemodynamics deteriorated progressively resulting in death. During the experiment, gradual leftward displacement of the interventricular septum (IVS) without any change in left ventricular (LV) free wall geometry was observed. In pulmonary embolic shock, which showed a fall in LV pressure to about 60 mmHg and cardiac output to about 40% of control, the leftward displacement of IVS became marked, and the cooperative movement of IVS to LV contraction disappeared. The IVS position during acute RV pressure overload was able to account for the transseptal pressure gradient. The importance of IVS position and motion in cardiac function during acute RV pressure overload was stressed. Furthermore, to establish the theoretical treatment in acute cardiopulmonary resuscitation, ligation of the descending aorta (AoL) or norepinephrine ("N") or isoproterenol ("I") administration were examined in a canine pulmonary embolic shock model. AoL or "N" improved the deteriorated hemodynamics with restoration of biventricular geometry. However, "I" did not restore the biventricular geometry despite the transiently improved hemodynamics, and the experimental animals were unable to survive. These results suggest the importance of the maintainance of systemic pressure for the restoration of failed RV function. Further integrated studies are required to understand biventricular interference and interdependency.
Polynomials in finite geometries and combinatorics
Blokhuis, A.; Walker, K.
1993-01-01
It is illustrated how elementary properties of polynomials can be used to attack extremal problems in finite and euclidean geometry, and in combinatorics. Also a new result, related to the problem of neighbourly cylinders is presented.
Algebra, Geometry and Mathematical Physics Conference
Paal, Eugen; Silvestrov, Sergei; Stolin, Alexander
2014-01-01
This book collects the proceedings of the Algebra, Geometry and Mathematical Physics Conference, held at the University of Haute Alsace, France, October 2011. Organized in the four areas of algebra, geometry, dynamical symmetries and conservation laws and mathematical physics and applications, the book covers deformation theory and quantization; Hom-algebras and n-ary algebraic structures; Hopf algebra, integrable systems and related math structures; jet theory and Weil bundles; Lie theory and applications; non-commutative and Lie algebra and more. The papers explore the interplay between research in contemporary mathematics and physics concerned with generalizations of the main structures of Lie theory aimed at quantization, and discrete and non-commutative extensions of differential calculus and geometry, non-associative structures, actions of groups and semi-groups, non-commutative dynamics, non-commutative geometry and applications in physics and beyond. The book benefits a broad audience of researchers a...
Attitudes of High School Students towards Geometry
Directory of Open Access Journals (Sweden)
Esat Avcı
2014-12-01
Full Text Available In this research, attitudes of high school students towards geometry were investigated in terms of gender, grade, types of the field and school. Population of research includes students who were studying at high school in five distincs of Mersin in 2013-2014 academical year. Sample of research includes 935 students from twelve high schools. Attitude scale which was developed by Su-Özenir (2008 was used for data collection. For data analysis, mean, standart deviation, t test and ANOVA were used. A meaningful difference between students’ attitudes towards geometry and variance of gender and grade level wasn’t observed, on the other hand a meaningful difference according to field and school type is observed.Key Words: Attitudes towards geometry, high school geometry lesson, attitude scale
Geometry, structure and randomness in combinatorics
Nešetřil, Jaroslav; Pellegrini, Marco
2014-01-01
This book collects some surveys on current trends in discrete mathematics and discrete geometry. The areas covered include: graph representations, structural graphs theory, extremal graph theory, Ramsey theory and constrained satisfaction problems.
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.