Three-body and four-body photodisintegrations of the 4He nuclei in the Δ region

International Nuclear Information System (INIS)

Niki, Kazuaki

1991-01-01

The differential and total cross sections were measured for the three-body (pnd) and four-body (ppnn) final states in photodisintegration of 4 He in an energy range between 125 and 445 MeV. The kinematic variables were determined in an almost complete way, using a large acceptance spectrometer together with the use of tagged photons of an energy resolution of 10 MeV. We have found that the three-body reaction 4 He(γ, pn)d makes a dominant contribution among various processes which lead to non-mesonic final states. The behavior of the 4 He(γ, pn)d cross section is well described by the quasi-deuteron model (QDM). On the other hand, the four-body breakup cross sections are not consistent with the prediction of the QDM. For these four-body reactions, photon absorption by three-nucleon clusters seems to give a dominant effect. The four-body cross sections also show a broad enhancement around 300 to 400 MeV, indicating a possible participation of the Δ to the reactions. (author)

Four-body interaction energy for compressed solid krypton from quantum theory.

Science.gov (United States)

Tian, Chunling; Wu, Na; Liu, Fusheng; Saxena, Surendra K; Zheng, Xingrong

2012-07-28

The importance of the four-body contribution in compressed solid krypton was first evaluated using the many-body expansion method and the coupled cluster theory with full single and double excitations plus perturbative treatment of triples. All different four-atom clusters existing in the first- and second-nearest neighbor shells of face-centered cubic krypton were considered, and both self-consistent-field Hartree-Fock and correlation parts of the four-body interaction were accurately determined from the ambient conditions up to eightfold volume compression. We find that the four-body interaction energy is negative at compression ratio lower than 2, where the dispersive forces play a dominant role. With increasing the compression, the four-body contribution becomes repulsive and significantly cancels the over-softening effects of the three-body potential. The obtained equation of state (EOS) was compared with the experiments and the density-functional theory calculations. It shows that combination of the four-body effects with two- and three-body interactions leads to an excellent agreement with EOS measurements throughout the whole experimental range 0-130 GPa, and extends the prediction to 300 GPa.

The Mind-Body Problem.

Science.gov (United States)

Fodor, Jerry A.

1981-01-01

Describes several different philosophies of mind with each philosophy's explanation of the mind-body problem. Philosophies discussed include dualism, materialism, functionalism, radical behaviorism, logical behaviorism and central-state identity. (DS)

The three-body problem from Pythagoras to Hawking

CERN Document Server

Valtonen, Mauri; Kholshevnikov, Konstantin; Mylläri, Aleksandr; Orlov, Victor; Tanikawa, Kiyotaka

2016-01-01

This book, written for a general readership, reviews and explains the three-body problem in historical context reaching to latest developments in computational physics and gravitation theory. The three-body problem is one of the oldest problems in science and it is most relevant even in today’s physics and astronomy. The long history of the problem from Pythagoras to Hawking parallels the evolution of ideas about our physical universe, with a particular emphasis on understanding gravity and how it operates between astronomical bodies. The oldest astronomical three-body problem is the question how and when the moon and the sun line up with the earth to produce eclipses. Once the universal gravitation was discovered by Newton, it became immediately a problem to understand why these three-bodies form a stable system, in spite of the pull exerted from one to the other. In fact, it was a big question whether this system is stable at all in the long run. Leading mathematicians attacked this problem over more than...

Numerical solutions of the N-body problem

International Nuclear Information System (INIS)

Marciniak, A.

1985-01-01

Devoted to the study of numerical methods for solving the general N-body problem and related problems, this volume starts with an overview of the conventional numerical methods for solving the initial value problem. The major part of the book contains original work and features a presentation of special numerical methods conserving the constants of motion in the general N-body problem and methods conserving the Jacobi constant in the problem of motion of N bodies in a rotating frame, as well as an analysis of the applications of both (conventional and special) kinds of methods for solving these problems. For all the methods considered, the author presents algorithms which are easily programmable in any computer language. Moreover, the author compares various methods and presents adequate numerical results. The appendix contains PL/I procedures for all the special methods conserving the constants of motion. 91 refs.; 35 figs.; 41 tabs

Poincaré and the three body problem

CERN Document Server

Barrow-Green, June

1997-01-01

The idea of chaos figures prominently in mathematics today. It arose in the work of one of the greatest mathematicians of the late 19th century, Henri Poincaré, on a problem in celestial mechanics: the three body problem. This ancient problem-to describe the paths of three bodies in mutual gravitational interaction-is one of those which is simple to pose but impossible to solve precisely. Poincaré's famous memoir on the three body problem arose from his entry in the competition celebrating the 60th birthday of King Oscar of Sweden and Norway. His essay won the prize and was set up in print as a paper in Acta Mathematica when it was found to contain a deep and critical error. In correcting this error Poincaré discovered mathematical chaos, as is now clear from Barrow-Green's pioneering study of a copy of the original memoir annotated by Poincaré himself, recently discovered in the Institut Mittag-Leffler in Stockholm. Poincaré and the Three Body Problem opens with a discussion of the development of the th...

Effective linear two-body method for many-body problems in atomic and nuclear physics

International Nuclear Information System (INIS)

Kim, Y.E.; Zubarev, A.L.

2000-01-01

We present an equivalent linear two-body method for the many body problem, which is based on an approximate reduction of the many-body Schroedinger equation by the use of a variational principle. The method is applied to several problems in atomic and nuclear physics. (author)

Psycho-physiologic emergentism; four minds in a body

Directory of Open Access Journals (Sweden)

David L. Rowland

2017-10-01

Full Text Available The mind-body problem represents one of the most debated topics in the neurosciences. From a psychological standpoint, abstract/non-material data are an intrinsic part of the mind, intervening to a large extent in reasoning and decision making processes. Imaging studies also show a strong correlation between higher cognitive functions (such as working memory and specific cerebral brain regions (a fronto-parietal network of interacting left and right brain areas. In contrast, the physical/material brain would be unable to interact with abstract-immaterial data, such that the psychological processing of abstract data (processes such as thinking, reasoning, and judgment is attributed to the mind, with the mind representing a distinct entity interposed between the brain and abstract-immaterial data. Recent data suggest that the mind-body problem may simply be an artifact of human experience/ understanding, as the brain actually represents actually an intrinsic part of the mind. Even if the physical brain is not able to interact with abstract mental data, the brain still could process abstract data through a dynamic association between the abstract data and cerebral stimuli/ impulses. This form of processing without interaction defines the mind as a complex neurobiological structure, with the unconscious part of the mind processing abstract-immaterial data in a conscious/ mental format. In this overview, important concepts of psycho-physiologic emergentism, including internal mental reality, internal mental existence, internal mental interaction, and structural and informational dichotomies of the brain, are iterated. Such concepts/properties represent a neuro-informational support system capable of generating four distinct minds within the single brain. Future studies should further develop the dynamic and immaterial-material nature of the mind, as a possible premise for a scientific definition and understanding of mental events like affectivity

AN ACCURATE ORBITAL INTEGRATOR FOR THE RESTRICTED THREE-BODY PROBLEM AS A SPECIAL CASE OF THE DISCRETE-TIME GENERAL THREE-BODY PROBLEM

International Nuclear Information System (INIS)

Minesaki, Yukitaka

2013-01-01

For the restricted three-body problem, we propose an accurate orbital integration scheme that retains all conserved quantities of the two-body problem with two primaries and approximately preserves the Jacobi integral. The scheme is obtained by taking the limit as mass approaches zero in the discrete-time general three-body problem. For a long time interval, the proposed scheme precisely reproduces various periodic orbits that cannot be accurately computed by other generic integrators

Bound states and scattering in four-body systems

International Nuclear Information System (INIS)

Narodetsky, I.M.

1979-01-01

It is the purpose of this review to provide the clear and elementary introduction in the integral equation method and to demonstrate explicitely its usefulness for the physical applications. The existing results concerning the application of the integral equation technique for the four-nucleon bound states and scattering are reviewed.The treatment is based on the quasiparticle approach that permits the simple interpretation of the equations in terms of quasiparticle scattering. The mathematical basis for the quasiparticle approach is the Hilbert-Schmidt theorem of the Fredholm integral equation theory. This paper contains the detailed discussion of the Hilbert-Schmidt expansion as applied to the 2-particle amplitudes and to the 3 + 1 and 2 + 2 amplitudes which are the kernels of the four-body equations. The review contains essentially the discussion of the four-body quasiparticle equations and results obtained for bound states and scattering

Lavine method applied to three body problems

International Nuclear Information System (INIS)

Mourre, Eric.

1975-09-01

The methods presently proposed for the three body problem in quantum mechanics, using the Faddeev approach for proving the asymptotic completeness, come up against the presence of new singularities when the potentials considered v(α)(x(α)) for two-particle interactions decay less rapidly than /x(α)/ -2 ; and also when trials are made for solving the problem with a representation space whose dimension for a particle is lower than three. A method is given that allows the mathematical approach to be extended to three body problem, in spite of singularities. Applications are given [fr

The two-body problem of a pseudo-rigid body and a rigid sphere

DEFF Research Database (Denmark)

Kristiansen, Kristian Uldall; Vereshchagin, M.; Gózdziewski, K.

2012-01-01

n this paper we consider the two-body problem of a spherical pseudo-rigid body and a rigid sphere. Due to the rotational and "re-labelling" symmetries, the system is shown to possess conservation of angular momentum and circulation. We follow a reduction procedure similar to that undertaken...... in the study of the two-body problem of a rigid body and a sphere so that the computed reduced non-canonical Hamiltonian takes a similar form. We then consider relative equilibria and show that the notions of locally central and planar equilibria coincide. Finally, we show that Riemann's theorem on pseudo......-rigid bodies has an extension to this system for planar relative equilibria....

Three-dimensional imaging of atomic four-body processes

CERN Document Server

Schulz, M; Fischer, D; Kollmus, H; Madison, D H; Jones, S; Ullrich, J

2003-01-01

To understand the physical processes that occur in nature we need to obtain a solid concept about the 'fundamental' forces acting between pairs of elementary particles. it is also necessary to describe the temporal and spatial evolution of many mutually interacting particles under the influence of these forces. This latter step, known as the few-body problem, remains an important unsolved problem in physics. Experiments involving atomic collisions represent a useful testing ground for studying the few-body problem. For the single ionization of a helium atom by charged particle impact, kinematically complete experiments have been performed since 1969. The theoretical analysis of such experiments was thought to yield a complete picture of the basic features of the collision process, at least for large collision energies. These conclusions are, however, almost exclusively based on studies of restricted electron-emission geometries. We report three- dimensional images of the complete electron emission pattern for...

Few-body problems

CERN Document Server

Hadjimichael, E

1986-01-01

This volume consists of two review articles. E Hadjimichael's contribution, 'The Nuclear Three-Body Systems', concentrates on recent experimental and theoretical progress achieved in the field. Together with a pedagogical survey of the theoretical framework extensive discussion on the 3N system in the continuum and reactions of electromagnetic probes with 3N systems are provided. 'Four-Nucleon Transfer Reactions' by W Oelert reviews many aspects of a-particle transfer studies. A careful and balanced presentation of both theory and experiment is given. Reasonable agreement between the two is ob

The relativistic atomic many-body problem

International Nuclear Information System (INIS)

Brown, G.E.

1987-01-01

Problems connected with the infinite negative energy sea of electrons in the atomic many-body problem are discussed. It is shown that as long as one works in mean-field approximations, wave functions do not need to suffer from continuum dissociation. Various effects from virtual pairs in the wave functions are discussed. (orig.)

The computationalist reformulation of the mind-body problem.

Science.gov (United States)

Marchal, Bruno

2013-09-01

Computationalism, or digital mechanism, or simply mechanism, is a hypothesis in the cognitive science according to which we can be emulated by a computer without changing our private subjective feeling. We provide a weaker form of that hypothesis, weaker than the one commonly referred to in the (vast) literature and show how to recast the mind-body problem in that setting. We show that such a mechanist hypothesis does not solve the mind-body problem per se, but does help to reduce partially the mind-body problem into another problem which admits a formulation in pure arithmetic. We will explain that once we adopt the computationalist hypothesis, which is a form of mechanist assumption, we have to derive from it how our belief in the physical laws can emerge from *only* arithmetic and classical computer science. In that sense we reduce the mind-body problem to a body problem appearance in computer science, or in arithmetic. The general shape of the possible solution of that subproblem, if it exists, is shown to be closer to "Platonist or neoplatonist theology" than to the "Aristotelian theology". In Plato's theology, the physical or observable reality is only the shadow of a vaster hidden nonphysical and nonobservable, perhaps mathematical, reality. The main point is that the derivation is constructive, and it provides the technical means to derive physics from arithmetic, and this will make the computationalist hypothesis empirically testable, and thus scientific in the Popperian analysis of science. In case computationalism is wrong, the derivation leads to a procedure for measuring "our local degree of noncomputationalism". Copyright © 2013 Elsevier Ltd. All rights reserved.

Four-body effects in the 6He+58Ni scattering

International Nuclear Information System (INIS)

Morcelle, V.; Pires, K.C.C.; Rodríguez-Gallardo, M.; Lichtenthäler, R.; Lépine-Szily, A.; Guimarães, V.; Faria, P.N. de; Mendes Junior, D.R.; Moro, A.M.; Gasques, L.R.; Leistenschneider, E.; Pampa Condori, R.; Scarduelli, V.; Morais, M.C.

2014-01-01

We present angular distributions of the 6 He+ 58 Ni scattering measured at three bombarding energies above the Coulomb barrier: E lab =12.2 MeV,16.5 MeV,and 21.7 MeV. The angular distributions have been analysed in terms of three- and four-body Continuum-Discretized Coupled-Channels calculations considering the effect of the 6 He breakup. A behaviour in the cross section at large angles has been observed which was reproduced only by the four-body Continuum-Discretized Coupled-Channels calculation.

Short history of nuclear many-body problem

International Nuclear Information System (INIS)

Köhler, H.S.

2014-01-01

This is a very short presentation regarding developments in the theory of nuclear many-body problems, as seen and experienced by the author during the past 60 years with particular emphasis on the contributions of Gerry Brown and his research-group. Much of his work was based on Brueckner's formulation of the nuclear many-body problem. It is reviewed briefly together with the Moszkowski–Scott separation method that was an important part of his early work. The core polarisation and his work related to effective interactions in general are also addressed

Sources of spurious force oscillations from an immersed boundary method for moving-body problems

Science.gov (United States)

Lee, Jongho; Kim, Jungwoo; Choi, Haecheon; Yang, Kyung-Soo

2011-04-01

When a discrete-forcing immersed boundary method is applied to moving-body problems, it produces spurious force oscillations on a solid body. In the present study, we identify two sources of these force oscillations. One source is from the spatial discontinuity in the pressure across the immersed boundary when a grid point located inside a solid body becomes that of fluid with a body motion. The addition of mass source/sink together with momentum forcing proposed by Kim et al. [J. Kim, D. Kim, H. Choi, An immersed-boundary finite volume method for simulations of flow in complex geometries, Journal of Computational Physics 171 (2001) 132-150] reduces the spurious force oscillations by alleviating this pressure discontinuity. The other source is from the temporal discontinuity in the velocity at the grid points where fluid becomes solid with a body motion. The magnitude of velocity discontinuity decreases with decreasing the grid spacing near the immersed boundary. Four moving-body problems are simulated by varying the grid spacing at a fixed computational time step and at a constant CFL number, respectively. It is found that the spurious force oscillations decrease with decreasing the grid spacing and increasing the computational time step size, but they depend more on the grid spacing than on the computational time step size.

Dependence of four-body observables on the range of UPA-like effective interactions

International Nuclear Information System (INIS)

Perne, R.; Sandhas, W.

1977-07-01

A generalized unitary pole approximation (UPA) concerning the three-body amplitudes in the kernel of four-body integral equations is introduced. We furhtermore study the dependence of the 4 He binding energy and of four-body cross sections upon a position space cut-off parameter in the effective interactions. (orig.) [de

Nucleon many-body problem using quantum-mechanical few-body technique

International Nuclear Information System (INIS)

Horiuchi, Wataru

2016-01-01

A nucleus is treated as a quantum-mechanical many-body system consisting of protons and neutrons that interact with each other by nuclear force. This paper explains the variational calculation using the correlated basis function as a powerful technique for obtaining the precise solution of Schroedinger equation of many-body, and tries to understand the nucleon many-body system from the viewpoint of a few-body through the application cases of various nuclear systems. It describes the important correlation that characterizes the nucleon many-body system such as the mean field, cluster, and tensor of bound state, and shows that non-bound state is also describable. Since such precise theory is mantic, it is essential for explaining the nature of unknown unstable nuclei, and for determining the nuclear reaction rate under the environment of the stars difficult for experiment. The method is general and flexible, and can be applied to various quantum-mechanical many-body problems. For example, the multi-body calculation of atoms and molecules, hypernuclei, and hadron spectroscopy can be carried out only by changing the potential and particles. (A.O.)

The three body problem with energy dependent potentials

International Nuclear Information System (INIS)

Kim, Y.E.; McKay, C.M.; McKellar, B.H.J.

1975-10-01

It is shown how to generalize the three body equations of Faddeev, and of Karlsson and Zeiger, to include the case when the two body potential is energy dependent. Such generalizations will prove useful in the three nucleon problem and in three body models of nuclear reactions. (author)

Four-body conversion of atomic helium ions

International Nuclear Information System (INIS)

de Vries, C.P.; Oskam, H.J.

1980-01-01

The conversion of atomic helium ions into molecular ions was studied in pure helium and in helium-neon mixtures containing between 0.1 at. % and 50 at. % neon. The experiments showed that the termolecular conversion reaction, He + +2He → He 2 + +He, is augmented by the four-body conversion reaction He + +3He → products, where the products could include either He 2 + or He 3 + ions. Conversion rate coefficients of (5.7 +- 0.8) x 10 -32 cm 6 sec -1 and (2.6 +- 0.4) x 10 -49 cm 9 sec -1 were found for the termolecular and four-body conversion reactions, respectively. In addition, rate coefficients for the following Ne + conversion reactions were measured: Ne + +He+He → (HeNe) + +He, (2.3 +- 0.1) x 10 -32 cm 6 sec -1 ; Ne + +He+Ne → (HeNe) + +Ne or Ne 2 + +He, (8.0 +- 0.8) x 10 -32 cm 6 sec -1 ; and Ne + +Ne+Ne → Ne 2 + +Ne, (5.1 +- 0.3) x 10 -32 cm 6 sec -1 . All rate coefficients are at a gas temperature of 295 K

Non-integrability of the Anisotropic Stormer Problem and the Isosceles Three-Body Problem

Science.gov (United States)

Nomikos, D. G.; Papageorgiou, V. G.

2009-02-01

We study the Anisotropic Stormer Problem (ASP) and the Isosceles Three-Body Problem (IP), from the viewpoint of integrability, using Morales-Ramis theory and its generalization. The study of their integrability presents particular interest since they model important physical phenomena. Both problems can be reduced with respect to the S1 symmetry. Almeida and Stuchi [M.A. Almeida, T.J. Stuchi, Non-integrability of the anisotropic Stormer problem with angular momentum, Physica D 189 (2004) 219-233] proved that the reduced ASP is non-integrable for almost all values of the parameters. In this paper we establish the non-integrability (in the extended Liouville sense) of the remaining cases. The IP is a special case of the three-body problem and it can be considered as a generalization of the Sitnikov problem. Here we prove that the complexified reduced IP does not admit an additional independent meromorphic first integral.

Four tails problems for dynamical collapse theories

Science.gov (United States)

McQueen, Kelvin J.

2015-02-01

The primary quantum mechanical equation of motion entails that measurements typically do not have determinate outcomes, but result in superpositions of all possible outcomes. Dynamical collapse theories (e.g. GRW) supplement this equation with a stochastic Gaussian collapse function, intended to collapse the superposition of outcomes into one outcome. But the Gaussian collapses are imperfect in a way that leaves the superpositions intact. This is the tails problem. There are several ways of making this problem more precise. But many authors dismiss the problem without considering the more severe formulations. Here I distinguish four distinct tails problems. The first (bare tails problem) and second (structured tails problem) exist in the literature. I argue that while the first is a pseudo-problem, the second has not been adequately addressed. The third (multiverse tails problem) reformulates the second to account for recently discovered dynamical consequences of collapse. Finally the fourth (tails problem dilemma) shows that solving the third by replacing the Gaussian with a non-Gaussian collapse function introduces new conflict with relativity theory.

Non-perturbative Calculation of the Scalar Yukawa Theory in Four-Body Truncation

International Nuclear Information System (INIS)

Li, Yang; Maris, P.; Vary, J. P.; Karmanov, V. A.

2015-01-01

The quenched scalar Yukawa theory is solved in the light-front Tamm–Dancoff approach including up to four constituents (one scalar nucleon, three scalar pions). The Fock sector dependent renormalization is implemented. By studying the Fock sector norms, we find that the lowest two Fock sectors dominate the state even in the large-coupling region. The one-body sector shows convergence with respect to the Fock sector truncation. However, the four-body norm exceeds the three-body norm at the coupling α≈1.7 . (author)

A continuum of periodic solutions to the planar four-body problem with two pairs of equal masses

Science.gov (United States)

Ouyang, Tiancheng; Xie, Zhifu

2018-04-01

In this paper, we apply the variational method with Structural Prescribed Boundary Conditions (SPBC) to prove the existence of periodic and quasi-periodic solutions for the planar four-body problem with two pairs of equal masses m1 =m3 and m2 =m4. A path q (t) on [ 0 , T ] satisfies the SPBC if the boundaries q (0) ∈ A and q (T) ∈ B, where A and B are two structural configuration spaces in (R2)4 and they depend on a rotation angle θ ∈ (0 , 2 π) and the mass ratio μ = m2/m1 ∈R+. We show that there is a region Ω ⊆ (0 , 2 π) ×R+ such that there exists at least one local minimizer of the Lagrangian action functional on the path space satisfying the SPBC { q (t) ∈H1 ([ 0 , T ] ,(R2)4) | q (0) ∈ A , q (T) ∈ B } for any (θ , μ) ∈ Ω. The corresponding minimizing path of the minimizer can be extended to a non-homographic periodic solution if θ is commensurable with π or a quasi-periodic solution if θ is not commensurable with π. In the variational method with the SPBC, we only impose constraints on the boundary and we do not impose any symmetry constraint on solutions. Instead, we prove that our solutions that are extended from the initial minimizing paths possess certain symmetries. The periodic solutions can be further classified as simple choreographic solutions, double choreographic solutions and non-choreographic solutions. Among the many stable simple choreographic orbits, the most extraordinary one is the stable star pentagon choreographic solution when (θ , μ) = (4 π/5, 1). Remarkably the unequal-mass variants of the stable star pentagon are just as stable as the equal mass choreographies.

The Psychological Four-Color Mapping Problem

Science.gov (United States)

Francis, Gregory; Bias, Keri; Shive, Joshua

2010-01-01

Mathematicians have proven that four colors are sufficient to color 2-D maps so that no neighboring regions share the same color. Here we consider the psychological 4-color problem: Identifying which 4 colors should be used to make a map easy to use. We build a model of visual search for this design task and demonstrate how to apply it to the task…

Quantum N-body problem with a minimal length

International Nuclear Information System (INIS)

Buisseret, Fabien

2010-01-01

The quantum N-body problem is studied in the context of nonrelativistic quantum mechanics with a one-dimensional deformed Heisenberg algebra of the form [x,p]=i(1+βp 2 ), leading to the existence of a minimal observable length √(β). For a generic pairwise interaction potential, analytical formulas are obtained that allow estimation of the ground-state energy of the N-body system by finding the ground-state energy of a corresponding two-body problem. It is first shown that in the harmonic oscillator case, the β-dependent term grows faster with increasing N than the β-independent term. Then, it is argued that such a behavior should also be observed with generic potentials and for D-dimensional systems. Consequently, quantum N-body bound states might be interesting places to look at nontrivial manifestations of a minimal length, since the more particles that are present, the more the system deviates from standard quantum-mechanical predictions.

Four-body wave function of π3He-system at the threshold energy

International Nuclear Information System (INIS)

Pupyshev, V.V.; Rakityanskij, S.A.

1985-01-01

On the basis of approximate four-body equations the wave function of π 3 He-system is calculated at zero kinetic energy of the pion. In the case when distances between all four particles are comparable with the nucleus size a strong distortion of the wave function of (3N)-subsystem caused by the presence of the pion is found. The calculated four-body function is represented in a semianalytical form, which makes it possible to apply it in different calculations

The four Es of problem gambling: a psychological measure of risk.

Science.gov (United States)

Rockloff, Matthew J; Dyer, Victoria

2006-01-01

A focus group of Reno area Gamblers Anonymous members identified four psychological traits contributing to risk for problem gambling, including: Escape, Esteem, Excess and Excitement. A panel of four experts authored 240 Likert-type items to measure these traits. By design, none of the items explicitly referred to gambling activities. Study 1 narrowed the field of useful items by employing a quasi-experimental design which compared the answers of Reno area Gamblers Anonymous members (N = 39) to a control sample (N = 34). Study 2 submitted successful items, plus new items authored with the knowledge gained from Study 1, to validation in a random sample telephone survey across Queensland, Australia (N=2577). The final 40 item Four Es scale (4Es) was reliable (alpha=.90); predicted gambling problems as measured by the Canadian Problem Gambling Index of Severity (PGSI, Ferris & Wynne (2001). The Canadian Problem Gambling Index: Final Report: Canadian Centre on Substance Abuse); and distinguished problem gamblers from persons with alcohol abuse problems. The new scale can provide a basis for further study in harm minimization, treatment, and theory development.

On the special relativistic two-body problem

International Nuclear Information System (INIS)

Afanas'ev, G.N.; Asanov, R.A.

1979-01-01

The Poincare method is applied to the consideration of the two-body problem within the Special Relativity. The formulation of the theory contains two arbitrary functions of the Lorentz invariants. A specific choice of these functions leads to the correct description of three crucial experiments of the General Relativity. The expansion on the inverse powers of the light velocity being performed, the approximate Lorentz covariant two-body equations without retardation effects are obtained

Continuum capture in the three-body problem

International Nuclear Information System (INIS)

Sellin, I.A.

1980-01-01

The three-body problem, especially the problem of electron capture to the continuum in heavy particle collisions is reviewed. Major topics covered include: second born-induced asymmetry in electron capture to the continuum; historical context, links to other tests of atomic scattering theory; experiments characterizing the velocity distribution of ECC electrons; other atomic physics tests of high velocity Born expansions; atom capture; capture by positrons; and pion capture to the continuum

The changing features of the body-mind problem.

Science.gov (United States)

Agassi, Joseph

2007-01-01

The body-mind problem invites scientific study, since mental events are repeated and repeatable and invite testable explanations. They seemed troublesome because of the classical theory of substance that failed to solve its own central problems. These are soluble with the aid of the theory of the laws of nature, particularly in its emergentist version [Bunge, M., 1980. The Body-mind Problem, Pergamon, Oxford] that invites refutable explanations [Popper, K.R., 1959. The Logic of Scientific Discovery, Hutchinson, London]. The view of mental properties as emergent is a modification of the two chief classical views, materialism and dualism. As this view invites testable explanations of events of the inner world, it is better than the quasi-behaviorist view of self-awareness as computer-style self-monitoring [Minsky, M., Laske, O., 1992. A conversation with Marvin Minsky. AI Magazine 13 (3), 31-45].

A psychiatric dialogue on the mind-body problem.

Science.gov (United States)

Kendler, K S

2001-07-01

Of all the human professions, psychiatry is most centrally concerned with the relationship of mind and brain. In many clinical interactions, psychiatrists need to consider both subjective mental experiences and objective aspects of brain function. This article attempts to summarize, in the form of a dialogue between a philosophically informed attending psychiatrist and three residents, the major philosophical positions on the mind-body problem. The positions reviewed include the following: substance dualism, property dualism, type identity, token identity, functionalism, eliminative materialism, and explanatory dualism. This essay seeks to provide a brief user-friendly introduction, from a psychiatric perspective, to current thinking about the mind-body problem.

Comparison of four software packages applied to a scattering problem

DEFF Research Database (Denmark)

Albertsen, Niels Christian; Chesneaux, Jean-Marie; Christiansen, Søren

1999-01-01

We investigate characteristic features of four different software packages by applying them to the numerical solution of a non-trivial physical problem in computer simulation, viz., scattering of waves from a sinusoidal boundary. The numerical method used is based on boundary collocation. This le......We investigate characteristic features of four different software packages by applying them to the numerical solution of a non-trivial physical problem in computer simulation, viz., scattering of waves from a sinusoidal boundary. The numerical method used is based on boundary collocation...

A New Class of Solvable Many-Body Problems

Directory of Open Access Journals (Sweden)

Francesco Calogero

2012-10-01

Full Text Available A new class of solvable N-body problems is identified. They describe N unit-mass point particles whose time-evolution, generally taking place in the complex plane, is characterized by Newtonian equations of motion ''of goldfish type'' (acceleration equal force, with specific velocity-dependent one-body and two-body forces featuring several arbitrary coupling constants. The corresponding initial-value problems are solved by finding the eigenvalues of a time-dependent N×N matrix U(t explicitly defined in terms of the initial positions and velocities of the N particles. Some of these models are asymptotically isochronous, i.e. in the remote future they become completely periodic with a period T independent of the initial data (up to exponentially vanishing corrections. Alternative formulations of these models, obtained by changing the dependent variables from the N zeros of a monic polynomial of degree N to its N coefficients, are also exhibited.

Foreign body-associated intestinal pyogranuloma resulting in intestinal obstruction in four dogs.

Science.gov (United States)

Papazoglou, L G; Tontis, D; Loukopoulos, P; Patsikas, M N; Hermanns, W; Kouti, V; Timotheou, T; Liapis, I; Tziris, N; Rallis, T S

2010-04-17

Intestinal obstruction resulting from an intramural foreign body-associated pyogranuloma was diagnosed in four dogs. Vomiting and weight loss were the main clinical signs. On physical examination, a mass in the abdomen was detected in three dogs. Abdominal radiography demonstrated the presence of soft tissue opacity in three of the dogs and gas-filled dilated intestinal loops in all four dogs. Abdominal ultrasonography showed hyperkinetic fluid-filled dilated intestinal loops and a hypoechoic small intestinal mass in all the dogs. Exploratory coeliotomy confirmed the presence of a jejunal mass, which was removed by resection and anastomosis in all the dogs. In one of the dogs a linear foreign body was also found cranial to the mass and was removed through a separate enterotomy incision. The lesions were diagnosed as foreign body-associated intestinal pyogranulomas on histological examination. Three dogs recovered without complications, but the fourth showed signs of septic peritonitis four days after surgery and was euthanased at the owner's request. The other three dogs remained disease-free 12 to 42 months after surgery.

The Quantum N-Body Problem and the Auxiliary Field Method

International Nuclear Information System (INIS)

Semay, C.; Buisseret, F.; Silvestre-Brac, B.

2011-01-01

Approximate analytical energy formulas for N-body semirelativistic Hamiltonians with one- and two-body interactions are obtained within the framework of the auxiliary field method. We first review the method in the case of nonrelativistic two-body problems. A general procedure is then given for N-body systems and applied to the case of baryons in the large-N c limit. (author)

RESEARCH NOTE POST-WEANING BODY MASS GAIN OF FOUR ...

African Journals Online (AJOL)

POST-WEANING BODY MASS GAIN OF FOUR BREEDS OF STEERS ON DIFFERENT. NUTRITIONAL LEVELS. H.P. Eloff and C.J.F. Liidemann. Mara Research Station, Msa 0922. Receipt of MS. 4.8.1977. In South Africa there are 2O breeds of cattle which are mainly kept for the purpose of beef production (van. Marle ...

Geometrical themes inspired by the n-body problem

CERN Document Server

Herrera, Haydeé; Herrera, Rafael

2018-01-01

Presenting a selection of recent developments in geometrical problems inspired by the N-body problem, these lecture notes offer a variety of approaches to study them, ranging from variational to dynamical, while developing new insights, making geometrical and topological detours, and providing historical references. A. Guillot’s notes aim to describe differential equations in the complex domain, motivated by the evolution of N particles moving on the plane subject to the influence of a magnetic field. Guillot studies such differential equations using different geometric structures on complex curves (in the sense of W. Thurston) in order to find isochronicity conditions.   R. Montgomery’s notes deal with a version of the planar Newtonian three-body equation. Namely, he investigates the problem of whether every free homotopy class is realized by a periodic geodesic. The solution involves geometry, dynamical systems, and the McGehee blow-up. A novelty of the approach is the use of energy-balance in order t...

Performance Characteristics and Prediction of Bodyweight using Linear Body Measurements in Four Strains of Broiler Chicken

OpenAIRE

I. Udeh; J.O. Isikwenu and G. Ukughere

2011-01-01

The objectives of this study were to compare the performance characteristics of four strains of broiler chicken from 2 to 8 weeks of age and predict body weight of the broilers using linear body measurements. The four strains of broiler chicken used were Anak, Arbor Acre, Ross and Marshall. The parameters recorded were bodyweight, weight gain, total feed intake, feed conversion ratio, mortality and some linear body measurements (body length, body width, breast width, drumstick length, shank l...

Two-body quantum mechanical problem on spheres

OpenAIRE

Shchepetilov, Alexey V.

2005-01-01

The quantum mechanical two-body problem with a central interaction on the sphere ${\\bf S}^{n}$ is considered. Using recent results in representation theory an ordinary differential equation for some energy levels is found. For several interactive potentials these energy levels are calculated in explicit form.

Topics in three body problems

International Nuclear Information System (INIS)

Amado, R.D.

1975-01-01

An overview of the formal theory of the three-body problem as it has developed in the past twelve years is given. The formal structure of the theory, some of the techniques that have developed for handling the theory, and some results on how general quantum mechanical principles structure the results, are presented. The discussion is held entirely in the context of non-relativistic quantum mechanics with short-range forces. In this presentation the main outline of the theory is stressed, often at the expense of mathematical rigour [pt

The few-body problem - some thoughts after the 1980 International Conference

International Nuclear Information System (INIS)

Moravcsik, M.J.; Oregon Univ., Eugene

1981-01-01

Recent progress in the few-body problem, as considered at the Ninth International Conference on the Few-body Problem, Eugene, Oregon, August 1980, is discussed. It is shown that these developments help to-wards the understanding of some of the systems properties of these few-body configurations, contribute to the testing of quark theories, give evidence for the validity or violation of conservation laws, add to the present knowledge of nuclear properties, off-shell nucleon-nucleon interaction and other component laws and provide reliable predictions which may be useful in applications extrinsic to the few-body itself, such as astrophysics, space physics or chemistry. (U.K.)

Spatial and temporal variation in cadmium body loads of four ...

African Journals Online (AJOL)

Increasing urbanization and industrialization along the coastal areas of False Bay in South Africa can endanger coastal ecosystems because of increasing metal pollution. To obtain baseline data on contamination levels in the intertidal zone, cadmium (Cd) body loads of four invertebrate species were measured seasonally ...

Modeling a four-layer location-routing problem

Directory of Open Access Journals (Sweden)

Mohsen Hamidi

2012-01-01

Full Text Available Distribution is an indispensable component of logistics and supply chain management. Location-Routing Problem (LRP is an NP-hard problem that simultaneously takes into consideration location, allocation, and vehicle routing decisions to design an optimal distribution network. Multi-layer and multi-product LRP is even more complex as it deals with the decisions at multiple layers of a distribution network where multiple products are transported within and between layers of the network. This paper focuses on modeling a complicated four-layer and multi-product LRP which has not been tackled yet. The distribution network consists of plants, central depots, regional depots, and customers. In this study, the structure, assumptions, and limitations of the distribution network are defined and the mathematical optimization programming model that can be used to obtain the optimal solution is developed. Presented by a mixed-integer programming model, the LRP considers the location problem at two layers, the allocation problem at three layers, the vehicle routing problem at three layers, and a transshipment problem. The mathematical model locates central and regional depots, allocates customers to plants, central depots, and regional depots, constructs tours from each plant or open depot to customers, and constructs transshipment paths from plants to depots and from depots to other depots. Considering realistic assumptions and limitations such as producing multiple products, limited production capacity, limited depot and vehicle capacity, and limited traveling distances enables the user to capture the real world situations.

Repulsive four-body interactions of α particles and quasistable nuclear α -particle condensates in heavy self-conjugate nuclei

Science.gov (United States)

Bai, Dong; Ren, Zhongzhou

2018-05-01

We study the effects of repulsive four-body interactions of α particles on nuclear α -particle condensates in heavy self-conjugate nuclei using a semianalytic approach, and find that the repulsive four-body interactions could decrease the critical number of α particles, beyond which quasistable α -particle condensate states can no longer exist, even if these four-body interactions make only tiny contributions to the total energy of the Hoyle-like state of 16O. Explicitly, we study eight benchmark parameter sets, and find that the critical number Ncr decreases by |Δ Ncr|˜1 -4 from Ncr˜11 with vanishing four-body interactions. We also discuss the effects of four-body interactions on energies and radii of α -particle condensates. Our study can be useful for future experiments to study α -particle condensates in heavy self-conjugate nuclei. Also, the experimental determination of Ncr will eventually help establish a better understanding on the α -particle interactions, especially the four-body interactions.

An initial boundary value problem for modeling a piezoelectric dipolar body

Science.gov (United States)

Marin, Marin; Öchsner, Andreas

2018-03-01

This study deals with the first initial boundary value problem in elasticity of piezoelectric dipolar bodies. We consider the most general case of an anisotropic and inhomogeneous elastic body having a dipolar structure. For two different types of restrictions imposed on the problem data, we prove two results regarding the uniqueness of solution, by using a different but accessible method. Then, the mixed problem is transformed in a temporally evolutionary equation on a Hilbert space, conveniently constructed based on the problem data. With the help of a known result from the theory of semigroups of operators, the existence and uniqueness of the weak solution for this equation are proved.

Spectral sum rules for the three-body problem

International Nuclear Information System (INIS)

Bolle, D.; Osborn, T.A.

1982-01-01

This paper derives a number of sum rules for nonrelativistic three-body scattering. These rules are valid for any finite region μ in the six-dimensional coordinate space. They relate energy moments of the trace of the onshell time-delay operator to the energy-weighted probability for finding the three-body bound-state wave functions in the region μ. If μ is all of the six-dimensional space, the global form of the sum rules is obtained. In this form the rules constitute higher-order Levinson's theorems for the three-body problem. Finally, the sum rules are extended to allow the energy momtns have complex powers

Key to good fit: body measurement problems specific to key ...

African Journals Online (AJOL)

Key to good fit: body measurement problems specific to key dimensions. ... to explore and describe the problems that the South African Clothing Industry currently ... A postal survey was conducted among South African apparel and footwear ...

Investigation of a four-body coupling in the one-dimensional extended Penson-Kolb-Hubbard model

Science.gov (United States)

Ding, Hanqin; Ma, Xiaojuan; Zhang, Jun

2017-09-01

The experimental advances in cold fermion gases motivates the investigation of a one-dimensional (1D) correlated electronic system by incorporating a four-body coupling. Using the low-energy field theory scheme and focusing on the weak-coupling regime, we extend the 1D Penson-Kolb-Hubbard (PKH) model at half filling. It is found that the additional four-body interaction may significantly modify the quantum phase diagram, favoring the presence of the superconducting phase even in the case of two-body repulsions.

Nuclear three-body problem and energy-dependent potentials

International Nuclear Information System (INIS)

Abdurakhmanov, A.; Akhmadkhodzhaev, B.; Zubarev, A.L.; Irgaziev, B.F.

1985-01-01

Energy-dependent potentials in the three-body problem are being considered. Three-particle equations for the case of pairing energy-dependent potentials are generalized and the problems related to this ambiguous generalization are investigated. In terms of the equations obtained the tritium binding energy and vertex coupling constants (Tdn) and (Tdν) are evaluated. The binding energy and, especially, coupling constants are shown to be sensitive to a shape of the energy-dependent potential

Hip-hop solutions of the 2N-body problem

Science.gov (United States)

Barrabés, Esther; Cors, Josep Maria; Pinyol, Conxita; Soler, Jaume

2006-05-01

Hip-hop solutions of the 2N-body problem with equal masses are shown to exist using an analytic continuation argument. These solutions are close to planar regular 2N-gon relative equilibria with small vertical oscillations. For fixed N, an infinity of these solutions are three-dimensional choreographies, with all the bodies moving along the same closed curve in the inertial frame.

Meson-baryon four-body reaction amplitudes in exact SU(4)

International Nuclear Information System (INIS)

Liede, I.; Maalampi, J.; Roos, M.

1976-01-01

Fully SU(4) symmetric meson-baryon four body reaction amplitudes are presented in terms of SU(4) eigenamplitudes. The mesons and baryons considered belong to the SU(4) representations 15 and 20, respectively. Using these reletions, the cross-sections for the production of charmed particles can be predicted from known uncharmed reactions. (author)

The scalar curvature problem on the four dimensional half sphere

CERN Document Server

Ben-Ayed, M; El-Mehdi, K

2003-01-01

In this paper, we consider the problem of prescribing the scalar curvature under minimal boundary conditions on the standard four dimensional half sphere. We provide an Euler-Hopf type criterion for a given function to be a scalar curvature for some metric conformal to the standard one. Our proof involves the study of critical points at infinity of the associated variational problem.

The Gravitational Million-Body Problem: A Multidisciplinary Approach to Star Cluster Dynamics

International Nuclear Information System (INIS)

Tremaine, Scott

2003-01-01

The gravitational N-body problem is to describe the evolution of an isolated system of N point masses interacting only through Newtonian gravitational forces. For N =2 the solution is due to Newton. For N =3 there is no general analytic solution, but the problem has occupied generations of illustrious physicists and mathematicians including Laplace, Lagrange, Gauss and Poincare, and inspired the modern subjects of nonlinear dynamics and chaos theory. The general gravitational N-body problem remains one of the oldest unsolved problems in physics. Many-body problems can be simpler than few-body problems, and many physicists have attempted to apply the methods of classical equilibrium statistical mechanics to the gravitational N-body problem for N >> 1. These applications have had only limited success, partly because the gravitational force is too strong at both small scales (the interparticle potential energy diverges) and large scales (energy is not extensive). Nevertheless, we now understand a rich variety of behaviour in large-N gravitating systems. These include the negative heat capacity of isolated, gravitationally bound systems, which is the basic reason why nuclear burning in the Sun is stable; Antonov's discovery that an isothermal, self-gravitating gas in a container is located at a saddle point, rather than a maximum, of the entropy when the gas is sufficiently dense and hence is unstable (the 'gravothermal catastrophe'); the process of core collapse, in which relaxation induces a self-similar evolution of the central core of the system towards (formally) infinite density in a finite time; and the remarkable phenomenon of gravothermal oscillations, in which the central density undergoes periodic oscillations by factors of a thousand or more on the relaxation timescale - but only if N ∼> 10 4 . The Gravitational Million-Body Problem is a monograph that describes our current understanding of the gravitational N-body problem. The authors have chosen to

THE MIND BODY PROBLEM: THE HERMENEUTICS OF AFRICAN ...

African Journals Online (AJOL)

principles in explaining the mind –body problem due to deep seated criticisms from the ..... over duly by his mathematical intercourse with mere materials and this made him to found his .... Ed. (New York: McGraw Hill), 1993, p. 90. 19 Emefie ...

Periodic Solutions for Circular Restricted -Body Problems

Directory of Open Access Journals (Sweden)

Xiaoxiao Zhao

2013-01-01

Full Text Available For circular restricted -body problems, we study the motion of a sufficiently small mass point (called the zero mass point in the plane of equal masses located at the vertices of a regular polygon. By using variational minimizing methods, for some , we prove the existence of the noncollision periodic solution for the zero mass point with some fixed wingding number.

A heuristic algorithm for a multi-product four-layer capacitated location-routing problem

Directory of Open Access Journals (Sweden)

Mohsen Hamidi

2014-01-01

Full Text Available The purpose of this study is to solve a complex multi-product four-layer capacitated location-routing problem (LRP in which two specific constraints are taken into account: 1 plants have limited production capacity, and 2 central depots have limited capacity for storing and transshipping products. The LRP represents a multi-product four-layer distribution network that consists of plants, central depots, regional depots, and customers. A heuristic algorithm is developed to solve the four-layer LRP. The heuristic uses GRASP (Greedy Randomized Adaptive Search Procedure and two probabilistic tabu search strategies of intensification and diversification to tackle the problem. Results show that the heuristic solves the problem effectively.

Institutional Solutions to the ``Two-Body Problem"

Science.gov (United States)

Knezek, P.

2005-05-01

The Committee on the Status of Women (CSWA), in conjunction with the Employment Committee (EC), will hold a special session that will focus on institutional approaches to solving the ``two-body problem". In step with the national employment trend, for the majority of astronomers with partners, those partners work outside the home. This is particularly true for female astronomers, who generally are married to professionals (and often to other astronomers). Academic and professional institutions that employ the majority of astronomers are now beginning to recognize the importance of addressing what has come to be known as the ``two-body" problem in order to attract and retain the best scientists. A few of those institutions are making pioneering efforts to create pro-active approaches to the issue of dual-career couples. The special session will feature two or three speakers involved with the administration at institutions with pro-active policies. This special session will be coupled with the normal afternoon CSWA session, which will focus on the other side of the issue - how dual-career couples have successfully approached the issue at institutions that do NOT have proactive policies.

Generating families in the restricted three-body problem

CERN Document Server

Hénon, Michel

The classical restricted three-body problem is of fundamental importance because of its applications in astronomy and space navigation, and also as a simple model of a non-integrable Hamiltonian dynamical system. A central role is played by periodic orbits, of which many have been computed numerically. This is the second volume of an attempt to explain and organize the material through a systematic study of generating families, the limits of families of periodic orbits when the mass ratio of the two main bodies becomes vanishingly small. We use quantitative analysis in the vicinity of bifurcations of types 1 and 2. In most cases the junctions between branches can now be determined. A first-order approximation of families of periodic orbits in the vicinity of a bifurcation is also obtained. This book is intended for scientists and students interested in the restricted problem, in its applications to astronomy and space research, and in the theory of dynamical systems.

The Kantian Attempt to Solve the Mind-Body Problem. A Critical Approach

Directory of Open Access Journals (Sweden)

Pedro Jesús Teruel

2014-11-01

Full Text Available The mind-body problem is one of the perennial challenges in the history of ideas. Immanuel Kant (1724-1804 tried to solve it through an approach with several modulations –parallel to his intellectual evolution– that brought him into contact with both the later projection of the theoretical issue (the mind brain problem and its practical side (the immortality question. In this paper I face the Kantian approach to the mind-body problem from a triple perspective: descriptive, appraising and critical.

Understanding the many-body expansion for large systems. III. Critical role of four-body terms, counterpoise corrections, and cutoffs

Science.gov (United States)

Liu, Kuan-Yu; Herbert, John M.

2017-10-01

Papers I and II in this series [R. M. Richard et al., J. Chem. Phys. 141, 014108 (2014); K. U. Lao et al., ibid. 144, 164105 (2016)] have attempted to shed light on precision and accuracy issues affecting the many-body expansion (MBE), which only manifest in larger systems and thus have received scant attention in the literature. Many-body counterpoise (CP) corrections are shown to accelerate convergence of the MBE, which otherwise suffers from a mismatch between how basis-set superposition error affects subsystem versus supersystem calculations. In water clusters ranging in size up to (H2O)37, four-body terms prove necessary to achieve accurate results for both total interaction energies and relative isomer energies, but the sheer number of tetramers makes the use of cutoff schemes essential. To predict relative energies of (H2O)20 isomers, two approximations based on a lower level of theory are introduced and an ONIOM-type procedure is found to be very well converged with respect to the appropriate MBE benchmark, namely, a CP-corrected supersystem calculation at the same level of theory. Results using an energy-based cutoff scheme suggest that if reasonable approximations to the subsystem energies are available (based on classical multipoles, say), then the number of requisite subsystem calculations can be reduced even more dramatically than when distance-based thresholds are employed. The end result is several accurate four-body methods that do not require charge embedding, and which are stable in large basis sets such as aug-cc-pVTZ that have sometimes proven problematic for fragment-based quantum chemistry methods. Even with aggressive thresholding, however, the four-body approach at the self-consistent field level still requires roughly ten times more processors to outmatch the performance of the corresponding supersystem calculation, in test cases involving 1500-1800 basis functions.

Understanding the many-body expansion for large systems. III. Critical role of four-body terms, counterpoise corrections, and cutoffs.

Science.gov (United States)

Liu, Kuan-Yu; Herbert, John M

2017-10-28

Papers I and II in this series [R. M. Richard et al., J. Chem. Phys. 141, 014108 (2014); K. U. Lao et al., ibid. 144, 164105 (2016)] have attempted to shed light on precision and accuracy issues affecting the many-body expansion (MBE), which only manifest in larger systems and thus have received scant attention in the literature. Many-body counterpoise (CP) corrections are shown to accelerate convergence of the MBE, which otherwise suffers from a mismatch between how basis-set superposition error affects subsystem versus supersystem calculations. In water clusters ranging in size up to (H 2 O) 37 , four-body terms prove necessary to achieve accurate results for both total interaction energies and relative isomer energies, but the sheer number of tetramers makes the use of cutoff schemes essential. To predict relative energies of (H 2 O) 20 isomers, two approximations based on a lower level of theory are introduced and an ONIOM-type procedure is found to be very well converged with respect to the appropriate MBE benchmark, namely, a CP-corrected supersystem calculation at the same level of theory. Results using an energy-based cutoff scheme suggest that if reasonable approximations to the subsystem energies are available (based on classical multipoles, say), then the number of requisite subsystem calculations can be reduced even more dramatically than when distance-based thresholds are employed. The end result is several accurate four-body methods that do not require charge embedding, and which are stable in large basis sets such as aug-cc-pVTZ that have sometimes proven problematic for fragment-based quantum chemistry methods. Even with aggressive thresholding, however, the four-body approach at the self-consistent field level still requires roughly ten times more processors to outmatch the performance of the corresponding supersystem calculation, in test cases involving 1500-1800 basis functions.

Health Behaviour and Body Mass Index Among Problem Gamblers

DEFF Research Database (Denmark)

Holst Algren, Maria; Ekholm, Ola; Davidsen, Michael

2015-01-01

Problem gambling is a serious public health issue. The objective of this study was to investigate whether past year problem gamblers differed from non-problem gamblers with regard to health behaviour and body mass index (BMI) among Danes aged 16 years or older. Data were derived from the Danish...... pattern and obesity was higher among problem gamblers than among non-problem gamblers. The associations found in this study remained significant after adjustment for sex, age, educational and cohabiting status as well as other risk factors. Our findings highlight the presence of a potential, public health...... Health and Morbidity Surveys in 2005 and 2010. Past year problem gambling was defined using the lie/bet questionnaire. Logistic regression analyses were used to examine the association between past year problem gambling and health behaviour and BMI. Problem gambling was associated with unhealthy...

Problem on eigenfunctions and eigenvalues for effective Hamiltonians in pair channels of four-particle systems

International Nuclear Information System (INIS)

Gurbanovich, N.S.; Zelenskaya, I.N.

1976-01-01

The solution for eigenfunction and eigenvalue for effective Hamiltonians anti Hsub(p) in two-particle channels corresponding to division of four particles into groups (3.1) and (2.2) is very essential in the four-body problem as applied to nuclear reactions. The interaction of anti√sub(p) in each channel may be written in the form of an integral operator which takes account of the structure of a target nucleus or of an incident particle and satisfying the integral equation. While assuming the two-particle potentials to be central, it is possible to expand the effective interactions anti√sub(p) in partial waves and write the radial equation for anti Hsub(p). In the approximation on a mass shell the radial equations for the eigenfunctions of Hsub(p) are reduced to an algebraic equations system. The coefficients of the latter are expressed through the Fourier images for products of wave functions of bound clusters and the two-particle central potential which are localized in a momentum space

The four-body system made up of hydrogen and antihydrogen

International Nuclear Information System (INIS)

Armour, E.A.G.; Chamberlain, C.W.

2002-01-01

In view of current interest in the trapping of antihydrogen (H) atoms at low temperatures, we have investigated the reasons for considering that H-H does not have a bound state. We go on to carry out a four-body variational calculation for s-wave hydrogen-antihydrogen scattering, using the Kohn variational method. This is a continuation of earlier work on H-H interactions. Refs. 21 (author)

Pavlov and the mind-body problem.

Science.gov (United States)

Windholz, G

1997-01-01

I. P. Pavlov claimed that the mind-body problem would ultimately be resolved by empirical methods, rather than by rational arguments. A committed monist, Pavlov was confronted by dualism in the case of an hysterical person. Under normal conditions, her body's left side was insensitive to pain, but when she was hypnotized, there was a reversal of her sensitivity to pain, with the right side becoming insensitive. Pavlov acknowledged that the divergence between stimulation and response suggested dualism, yet condemned his disciple G.P. Zelenyĭ as well as Charles S. Sherrington, for their dualistic tendencies. Pavlov's continuous adherence to monism it attributed to the influence of popular scientific books that he read during his adolescence. The books maintained that science was based upon monism. Pavlov proposed that by introducing the concept of emotions, an hysterical person's condition could be explained within the framework of his theory of higher nervous activity, thereby obviating the need to change his paradigm.

The hyperspherical-harmonics expansion method and the integral-equation approach to solving the few-body problem in momentum space

International Nuclear Information System (INIS)

Liu, F.-Q.; Lim, T.K.

1988-01-01

The Faddeev and Faddeev-Yakubovsky equations for three- and four-body systems are solved by applying the hyperspherical-harmonics expansion to them in momentum space. This coupling of two popular approaches to the few-body problem together with the use of the so-called Raynal-Revai transformation, which relates hyperspherical functions, allows the few-body equations to be written as one-dimensional coupled integral equations. Numerical solutions for these are achieved through standard matrix methods; these are made straightforward, because a second transformation renders potential multipoles easily calculable. For sample potentials and a restricted size of matrix in each case, the binding energies extracted match those previously obtained in solving the Schroedinger equation through the hyperspherical-harmonics expansion in coordinate space. 9 refs

Hyperspherical Coulomb spheroidal basis in the Coulomb three-body problem

International Nuclear Information System (INIS)

Abramov, D. I.

2013-01-01

A hyperspherical Coulomb spheroidal (HSCS) representation is proposed for the Coulomb three-body problem. This is a new expansion in the set of well-known Coulomb spheroidal functions. The orthogonality of Coulomb spheroidal functions on a constant-hyperradius surface ρ = const rather than on a constant-internuclear-distance surface R = const, as in the traditional Born-Oppenheimer approach, is a distinguishing feature of the proposed approach. Owing to this, the HSCS representation proves to be consistent with the asymptotic conditions for the scattering problem at energies below the threshold for three-body breakup: only a finite number of radial functions do not vanish in the limit of ρ→∞, with the result that the formulation of the scattering problem becomes substantially simpler. In the proposed approach, the HSCS basis functions are considerably simpler than those in the well-known adiabatic hyperspherical representation, which is also consistent with the asymptotic conditions. Specifically, the HSCS basis functions are completely factorized. Therefore, there arise no problems associated with avoided crossings of adiabatic hyperspherical terms.

Solution of four-nucleon integral equations using the effective UPA

International Nuclear Information System (INIS)

Perne, R.; Sandhas, W.

1978-01-01

In the three-body case it is standard to either solve the (two-dimensional) Faddeev equations directly, or to reduce them first to one-dimensional equations by means of separable approximation (expansion) of the underlying two-body interactions. The basic four-body operator identities are reduced by the latter treatment to effective three-body equations only. These may be handled like their genuine three-body analoga, i.e., by directly solving them, or by expanding the effective interactions ocurring into separable terms. Such a procedure provides us in a second step with one-dimensional integral equations for the four-body problem, too. (orig./WL) [de

LAGRANGE SOLUTIONS TO THE DISCRETE-TIME GENERAL THREE-BODY PROBLEM

International Nuclear Information System (INIS)

Minesaki, Yukitaka

2013-01-01

There is no known integrator that yields exact orbits for the general three-body problem (G3BP). It is difficult to verify whether a numerical procedure yields the correct solutions to the G3BP because doing so requires knowledge of all 11 conserved quantities, whereas only six are known. Without tracking all of the conserved quantities, it is possible to show that the discrete general three-body problem (d-G3BP) yields the correct orbits corresponding to Lagrange solutions of the G3BP. We show that the d-G3BP yields the correct solutions to the G3BP for two special cases: the equilateral triangle and collinear configurations. For the triangular solution, we use the fact that the solution to the three-body case is a superposition of the solutions to the three two-body cases, and we show that the three bodies maintain the same relative distances at all times. To obtain the collinear solution, we assume a specific permutation of the three bodies arranged along a straight rotating line, and we show that the d-G3BP maintains the same distance ratio between two bodies as in the G3BP. Proving that the d-G3BP solutions for these cases are equivalent to those of the G3BP makes it likely that the d-G3BP and G3BP solutions are equivalent in other cases. To our knowledge, this is the first work that proves the equivalence of the discrete solutions and the Lagrange orbits.

Geometric characterization for the least Lagrangian action of n-body problems

Institute of Scientific and Technical Information of China (English)

ZHANG; Shiqing

2001-01-01

［1］Manev, G., La gravitation et l'énergie au zéro, Comptes Rendus, 924, 78: 259.［2］Diacu, F. N., Near-collision dynamics for particle systems with quasihomogeneous potentials, J. of Diff. Equ., 996, 28: 58.［3］Ambrosetti, A., Coti Zelati, V., Periodic Solutions of Singular Lagrangian Systems, Basel: Birkhuser, 993.［4］Arnold, V., Kozlov, V., Neishtadt, A., Dynamical Systems (iii): Mathematical Aspects of Classical and Celestial Mechanics, Berlin: Springer-Verlag, 988.［5］Chenciner, A., Desolneux, N., Minima de l'intégrale d'action et équilibres relatifs de n corps, C R Acad. Sci. Paris, serie I, 998, 326: 209.［6］Coti Zelati, V., The periodic solutions of n-body type problems, Ann IHP Anal nonlinéaire, 990, 7: 477.［7］Euler, L., De motu rectilineo trium corprum se mutuo attrahentium, Novi. Comm. Acad. Sci. Imp. Petropll, 767: 45.［8］Gordon, W., A minimizing property of Keplerian orbits, Amer. J. Math., 977, 99: 96.［9］Lagrange, J., Essai sur le problé me des trois corps, 772, Ouvres, 783, 3: 229.［10］Long, Y., Zhang, S. Q., Geometric characterization for variational minimization solutions of the 3-body problem, Chinese Science Bulletin, 999, 44(8): 653.［11］Long, Y., Zhang, S. Q., Geometric characterization for variational minimization solutions of the 3-body problem with fixed energy, J. of Diff. Equ., 2000, 60: 422.［12］Meyer, K., Hall, G., Introduction to Hamiltonian systems and the n-body problems, Berlin: Springer-Verlag,992.［13］Serra, E., Terracini, S., Collisionless periodic solutions to some three-body problems, Arch. Rational Mech. Anal., 992, 20: 305.［14］Siegle, C., Moser, J., Lectures on Celestial Mechanics, Berlin: Springer-Verlag, 97.［15］Wintner, A., Analytical Foundations of Celestial Mechanics, Princeton: Princeton University Press, 94.［16］Hardy, G., Littlewood, J., Pólya, G., Inequalities, 2nd ed., Cambridge: Combridge University Press, 952.

Framing the Mind-Body Problem in Contemporary Neuroscientific and Sunni Islamic Theological Discourse.

Science.gov (United States)

Qazi, Faisal; Fette, Don; Jafri, Syed S; I Padela, Aasim

2018-07-01

Famously posed by seventeenth-century French philosopher René Descartes, the mind-body problem remains unresolved in western philosophy and science, with both disciplines unable to move convincingly beyond the dualistic model. The persistence of dualism calls for a reframing of the problem through interdisciplinary modes of inquiry that include non-western points of view. One such perspective is Islamic theology of the soul, which, while approaching the problem from a distinct point of view, also adopts a position commensurate with (substance) dualism. Using this point of convergence as a conceptual starting point, we argue that bringing into dialogue contemporary neuroscientific, philosophy of mind, and Sunni Islamic theological discourses may provide a fruitful way of reframing the age-old mind-body problem. This paper provides an overview of how these three discourses have approached the issue of the mind-body (-soul) problem. Juxtaposing these three discourses, we hope, may ignite further scholarly dialogue and investigation.

On the libration collinear points in the restricted three – body problem

Directory of Open Access Journals (Sweden)

Alzahrani F.

2017-03-01

Full Text Available In the restricted problem of three bodies when the primaries are triaxial rigid bodies, the necessary and sufficient conditions to find the locations of the three libration collinear points are stated. In addition, the Linear stability of these points is studied for the case of the Euler angles of rotational motion being θi = 0, ψi + φi = π/2, i = 1, 2 accordingly. We underline that the model studied in this paper has special importance in space dynamics when the third body moves in gravitational fields of planetary systems and particularly in a Jupiter model or a problem including an irregular asteroid.

The three-body problem and equivariant Riemannian geometry

Science.gov (United States)

Alvarez-Ramírez, M.; García, A.; Meléndez, J.; Reyes-Victoria, J. G.

2017-08-01

We study the planar three-body problem with 1/r2 potential using the Jacobi-Maupertuis metric, making appropriate reductions by Riemannian submersions. We give a different proof of the Gaussian curvature's sign and the completeness of the space reported by Montgomery [Ergodic Theory Dyn. Syst. 25, 921-947 (2005)]. Moreover, we characterize the geodesics contained in great circles.

Four-body cluster structure of $A=7-10$ double-$\\Lambda$ hypernuclei

OpenAIRE

Hiyama, E.; Kamimura, M.; Motoba, T.; Motoba, T.; Yamamoto, Y.

2002-01-01

Energy levels of the double-$\\Lambda$ hypernuclei $_\\Lambda^{}$$_\\Lambda^7$He, $_\\Lambda^{}$$_\\Lambda^7$Li, $_\\Lambda^{}$$_\\Lambda^8$Li, $_\\Lambda^{}$$_\\Lambda^9$Li, $_\\Lambda^{}$$_\\Lambda^9$Be and $_\\Lambda^{}$$_\\Lambda^{10}$Be are predicted on the basis of the $\\alpha+x+\\Lambda +\\Lambda$ four-body model with $x=n, p, d, t, ^3$He and $\\alpha$, respectively.

Introduction to Hamiltonian dynamical systems and the N-body problem

CERN Document Server

Meyer, Kenneth R

2017-01-01

This third edition text provides expanded material on the restricted three body problem and celestial mechanics. With each chapter containing new content, readers are provided with new material on reduction, orbifolds, and the regularization of the Kepler problem, all of which are provided with applications. The previous editions grew out of graduate level courses in mathematics, engineering, and physics given at several different universities. The courses took students who had some background in differential equations and lead them through a systematic grounding in the theory of Hamiltonian mechanics from a dynamical systems point of view. This text provides a mathematical structure of celestial mechanics ideal for beginners, and will be useful to graduate students and researchers alike. Reviews of the second edition: "The primary subject here is the basic theory of Hamiltonian differential equations studied from the perspective of differential dynamical systems. The N-body problem is used as the primary exa...

Coulomb two-body problem with internal structure

International Nuclear Information System (INIS)

Kuperin, Yu.A.; Makarov, K.A.; Mel'nikov, Yu.B.

1988-01-01

The methods of the theory of extensions to an enlarged Hilbert space are used to construct a model of the interaction of the external (Coulomb) and internal (quark) channels in the two-body problem. The mutual influence of the spectra of the corresponding channel Hamiltonians is studied: it leads, in particular, to a rearrangement of the spectra of hadronic atoms. An explicit representation is obtained for the S matrix, and its singularities on the energy shell are studied

The effects of cosmetic surgery on body image, self-esteem, and psychological problems.

Science.gov (United States)

von Soest, T; Kvalem, I L; Roald, H E; Skolleborg, K C

2009-10-01

This study aims to investigate whether cosmetic surgery has an effect on an individual's body image, general self-esteem, and psychological problems. Further tests were conducted to assess whether the extent of psychological problems before surgery influenced improvements in postoperative psychological outcomes. Questionnaire data from 155 female cosmetic surgery patients from a plastic surgery clinic were obtained before and approximately 6 months after surgery. The questionnaire consisted of measures on body image, self-esteem, and psychological problems. Pre- and postoperative values were compared. Pre- and postoperative measures were also compared with the data compiled from a representative sample of 838 Norwegian women, aged 22-55, with no cosmetic surgery experience. No differences in psychological problems between the presurgery patient and comparison samples were found, whereas differences in body image and self-esteem between the sample groups were reported in an earlier publication. Analyses further revealed an improvement in body image (satisfaction with own appearance) after surgery. A significant but rather small effect on self-esteem was also found, whereas the level of psychological problems did not change after surgery. Postoperative measures of appearance satisfaction, self-esteem, and psychological problems did not differ from values derived from the comparison sample. Finally, few psychological problems before surgery predicted a greater improvement in appearance satisfaction and self-esteem after surgery. The study provides evidence of improvement in satisfaction with own appearance after cosmetic surgery, a variable that is thought to play a central role in understanding the psychology of cosmetic surgery patients. The study also points to the factors that surgeons should be aware of, particularly the role of psychological problems, which could inhibit the positive effects of cosmetic surgery.

Perceived body weight, eating and exercise problems of different groups of women.

Science.gov (United States)

Coker, Elise; Telfer, James; Abraham, Suzanne

2012-10-01

To compare prevalence of problems with body weight, eating and exercise (past or present) of female psychiatric inpatients with routine care, gynaecological and obstetric female outpatients, and eating disorder inpatients. One thousand and thirty-eight females aged 18-55 years from routine care (n=99), gynaecological (n=263) and obstetric (n=271) outpatient clinics, and eating disorder (n=223) and general psychiatric units (n=182) participated. Participants self-reported past or current problems with weight, eating and exercise using a short survey. A sub-sample of women completed the Eating and Exercise Examination (EEE) which includes the Quality of Life for Eating Disorders (QOL ED). The prevalence of self-reported problems controlling weight (52%), disordered eating and eating disorders (43%) for the psychiatric patients was significantly greater than for the routine care and gynaecological and obstetrics outpatients. The psychiatric group had a significantly higher mean body mass index (BMI) of 27.3 kg/m(2) (standard deviation (SD)=6.7) and prevalence of self-reported obesity (28%) than the other groups. Treatment of women with psychiatric problems should include assessment and concurrent attention to body weight, eating disorder and exercise problems in association with appropriate medical, psychiatric, psychological and medication treatment of their presenting disorder.

Solution of the Chandler-Gibson equations for a three-body test problem

International Nuclear Information System (INIS)

Gibson, A.G.; Waters, A.J.; Berthold, G.H.; Chandler, C.

1991-01-01

The Chandler-Gibson (CG) N-body equations are tested by considering the problem of three nonrelativistic particles moving on a line and interacting through attractive delta-function potentials. In particular, the input Born and overlap matrix-valued functions are evaluated analytically, and the CG equations are solved using a B-spline collocation method. The computed scattering matrix elements are within 0.5% of the known exact solutions, and the corresponding scattering probabilities are within 0.001% of the exact probabilities, both below and above the 3-body breakup threshold. These results establish that the CG method is practical, as well as theoretically correct, and may be a valuable approach for solving certain more complicated N-body scattering problems

Fermion bag solutions to some sign problems in four-fermion field theories

International Nuclear Information System (INIS)

Li, Anyi

2013-01-01

Lattice four-fermion models containing N flavors of staggered fermions, that are invariant under Z 2 and U(1) chiral symmetries, are known to suffer from sign problems when formulated using the auxiliary field approach. Although these problems have been ignored in previous studies, they can be severe. In this talk, we show that the sign problems disappear when the models are formulated in the fermion bag approach, allowing us to solve them rigorously for the first time.

Fermion bag solutions to some sign problems in four-fermion field theories

Science.gov (United States)

Li, Anyi

2013-04-01

Lattice four-fermion models containing N flavors of staggered fermions, that are invariant under Z2 and U(1) chiral symmetries, are known to suffer from sign problems when formulated using the auxiliary field approach. Although these problems have been ignored in previous studies, they can be severe. In this talk, we show that the sign problems disappear when the models are formulated in the fermion bag approach, allowing us to solve them rigorously for the first time.

BOOK REVIEW: The Gravitational Million-Body Problem: A Multidisciplinary Approach to Star Cluster Dynamics

Science.gov (United States)

Heggie, D.; Hut, P.

2003-10-01

The gravitational N-body problem is to describe the evolution of an isolated system of N point masses interacting only through Newtonian gravitational forces. For N =2 the solution is due to Newton. For N =3 there is no general analytic solution, but the problem has occupied generations of illustrious physicists and mathematicians including Laplace, Lagrange, Gauss and Poincaré, and inspired the modern subjects of nonlinear dynamics and chaos theory. The general gravitational N-body problem remains one of the oldest unsolved problems in physics. Many-body problems can be simpler than few-body problems, and many physicists have attempted to apply the methods of classical equilibrium statistical mechanics to the gravitational N-body problem for N gg 1. These applications have had only limited success, partly because the gravitational force is too strong at both small scales (the interparticle potential energy diverges) and large scales (energy is not extensive). Nevertheless, we now understand a rich variety of behaviour in large-N gravitating systems. These include the negative heat capacity of isolated, gravitationally bound systems, which is the basic reason why nuclear burning in the Sun is stable; Antonov's discovery that an isothermal, self-gravitating gas in a container is located at a saddle point, rather than a maximum, of the entropy when the gas is sufficiently dense and hence is unstable (the 'gravothermal catastrophe'); the process of core collapse, in which relaxation induces a self-similar evolution of the central core of the system towards (formally) infinite density in a finite time; and the remarkable phenomenon of gravothermal oscillations, in which the central density undergoes periodic oscillations by factors of a thousand or more on the relaxation timescale - but only if N gtrsim 104. The Gravitational Million-Body Problem is a monograph that describes our current understanding of the gravitational N-body problem. The authors have chosen to

Nuclear Astrophysics from View Point of Few-Body Problems

International Nuclear Information System (INIS)

Tumino, A.; Spitaleri, C.; Bertulani, C.; Mukhamedzhanov, A.M.

2013-01-01

Few-body systems provide very useful tools to solve different problems for nuclear astrophysics. This is the case of indirect techniques, developed to overcome some of the limits of direct measurements at astrophysical energies. Here the Coulomb dissociation, the asymptotic normalization coefficient and the Trojan Horse method are discussed. (author)

Lyapunov vs. geometrical stability analysis of the Kepler and the restricted three body problems

International Nuclear Information System (INIS)

Yahalom, A.; Levitan, J.; Lewkowicz, M.; Horwitz, L.

2011-01-01

In this Letter we show that although the application of standard Lyapunov analysis predicts that completely integrable Kepler motion is unstable, the geometrical analysis of Horwitz et al. predicts the observed stability. This seems to us to provide evidence for both the incompleteness of the standard Lyapunov analysis and the strength of the geometrical analysis. Moreover, we apply this approach to the three body problem in which the third body is restricted to move on a circle of large radius which induces an adiabatic time dependent potential on the second body. This causes the second body to move in a very interesting and intricate but periodic trajectory; however, the standard Lyapunov analysis, as well as methods based on the parametric variation of curvature associated with the Jacobi metric, incorrectly predict chaotic behavior. The geometric approach predicts the correct stable motion in this case as well. - Highlights: → Lyapunov analysis predicts Kepler motion to be unstable. → Geometrical analysis predicts the observed stability. → Lyapunov analysis predicts chaotic behavior in restricted three body problem. → The geometric approach predicts the correct stable motion in restricted three body problem.

Two-body problem for Weber-like interactions

International Nuclear Information System (INIS)

Clemente, R.A.; Assis, A.K.T.

1991-01-01

The problem of two moving bodies interacting through a Weber-like force is presented. Trajectories are obtained analytically once relativistic and quantic considerations are neglected. The main results are that in the case of limited trajectories, in general, they are not closed and in the case of open trajectories, the deflection angles are not the same for similar particles with given energies and angular momenta but opposite potentials. This last feature suggests the possibility of a direct verification of the validity of Weber's law of force for electromagnetic interactions

Lagrangian relative equilibria for a gyrostat in the three-body problem: bifurcations and stability

Energy Technology Data Exchange (ETDEWEB)

Guirao, Juan L G; Vera, Juan A, E-mail: juan.garcia@upct.e, E-mail: juanantonio.vera@upct.e [Departamento de Matematica Aplicada y EstadIstica, Universidad Politecnica de Cartagena, Hospital de Marina, 30203 Cartagena, Region de Murcia (Spain)

2010-05-14

In this paper we consider the non-canonical Hamiltonian dynamics of a gyrostat in the frame of the three-body problem. Using geometric/mechanic methods we study the approximate dynamics of the truncated Legendre series representation of the potential of an arbitrary order. Working in the reduced problem, we study the existence of relative equilibria that we refer to as Lagrange type following the analogy with the standard techniques. We provide necessary and sufficient conditions for the linear stability of Lagrangian relative equilibria if the gyrostat morphology form is close to a sphere. Thus, we generalize the classical results on equilibria of the three-body problem and many results on them obtained by the classic approach for the case of rigid bodies.

Free time minimizers for the three-body problem

Science.gov (United States)

Moeckel, Richard; Montgomery, Richard; Sánchez Morgado, Héctor

2018-03-01

Free time minimizers of the action (called "semi-static" solutions by Mañe in International congress on dynamical systems in Montevideo (a tribute to Ricardo Mañé), vol 362, pp 120-131, 1996) play a central role in the theory of weak KAM solutions to the Hamilton-Jacobi equation (Fathi in Weak KAM Theorem in Lagrangian Dynamics Preliminary Version Number 10, 2017). We prove that any solution to Newton's three-body problem which is asymptotic to Lagrange's parabolic homothetic solution is eventually a free time minimizer. Conversely, we prove that every free time minimizer tends to Lagrange's solution, provided the mass ratios lie in a certain large open set of mass ratios. We were inspired by the work of Da Luz and Maderna (Math Proc Camb Philos Soc 156:209-227, 1980) which showed that every free time minimizer for the N-body problem is parabolic and therefore must be asymptotic to the set of central configurations. We exclude being asymptotic to Euler's central configurations by a second variation argument. Central configurations correspond to rest points for the McGehee blown-up dynamics. The large open set of mass ratios are those for which the linearized dynamics at each Euler rest point has a complex eigenvalue.

Realizing all reduced syzygy sequences in the planar three-body problem

International Nuclear Information System (INIS)

Moeckel, Richard; Montgomery, Richard

2015-01-01

The configuration space of the planar three-body problem, reduced by rotations and with collisions excluded, has a rich topology which supports a large set of free homotopy classes. These classes have a simple description in terms of syzygy (or eclipse) sequences. Each homotopy class corresponds to a unique ‘reduced’ syzygy sequence. We prove that each reduced syzygy sequence is realized by a periodic solution of the rotation-reduced Newtonian planar three-body problem. The realizing solutions have small, nonzero angular momentum, repeatedly come very close to triple collision, and have lots of ‘stutters’—repeated syzygies of the same type, which cancel out up to homotopy. The heart of the proof stems from the work by one of us on symbolic dynamics arising out of the central configurations after the triple collision is blown up using McGehee's method. We end with a list of open problems. (paper)

Explicit solution to the N-body Calogero problem

Energy Technology Data Exchange (ETDEWEB)

Brink, L [Inst. of Theoretical Physics, CTH, Goeteborg (Sweden); Hansson, T H [Inst. of Theoretical Physics, Univ. Stockholm (Sweden); Vasiliev, M A [Dept. of Theoretical Physics, P.N. Lebedev Physical Inst., Moscow (Russia)

1992-07-23

We solve the N-body Calogero problem, i.e., N particles in one dimension subject to a two-body interaction of the form 1/2 {Sigma}{sub i,j} ((x{sub i}-x{sub j}){sup 2}+g/(x{sub i}-x{sub j}){sup 2}), by constructing annihilation and creation operators of the form a{sub i}{sup -+}=(1/{radical}2)(x{sub i}{+-}ip{sub i}) where p{sub i} is a modified momentum operator obeying Heisenberg-type commutation relations with x{sub i}, involving explicitly permutation operators. On the other hand, D{sub j}=ip{sub j} can be interpreted as a covariant derivative corresponding to a flat connection. The relation to fractional statistics in 1+1 dimensions and anyons in a strong magnetic field is briefly discussed. (orig.).

A dynamic contact problem between elasto-viscoplastic piezoelectric bodies

Directory of Open Access Journals (Sweden)

Tedjani Hadj ammar

2014-10-01

Full Text Available We consider a dynamic contact problem with adhesion between two elastic-viscoplastic piezoelectric bodies. The contact is frictionless and is described with the normal compliance condition. We derive variational formulation for the model which is in the form of a system involving the displacement field, the electric potential field and the adhesion field. We prove the existence of a unique weak solution to the problem. The proof is based on arguments of nonlinear evolution equations with monotone operators, a classical existence and uniqueness result on parabolic inequalities, differential equations and fixed point arguments.

New integrable problems in a rigid body dynamics with cubic integral in velocities

Science.gov (United States)

Elmandouh, A. A.

2018-03-01

We introduce a new family of the 2D integrable mechanical system possessing an additional integral of the third degree in velocities. This system contains 20 arbitrary parameters. We also clarify that the majority of the previous systems with a cubic integral can be reconstructed from it as a special version for certain values of those parameters. The applications of this system are extended to include the problem of motion of a particle and rigid body about its fixed point. We announce new integrable problems describing the motion of a particle in the plane, pseudosphere, and surfaces of variable curvature. We also present a new integrable problem in a rigid body dynamics and this problem generalizes some of the previous results for Sokolov-Tsiganov, Yehia, Stretensky, and Goriachev.

Transformations of the perturbed two-body problem to unperturbed harmonic oscillators

Energy Technology Data Exchange (ETDEWEB)

Szebehely, V; Bond, V

1983-05-01

Singular, nonlinear, and Liapunov unstable equations are made regular and linear through transformations that change the perturbed planar problem of two bodies into unperturbed and undamped harmonic oscillators with constant coefficients, so that the stable solution may be immediately written in terms of the new variables. The use of arbitrary and special functions for the transformations allows the systematic discussion of previously introduced and novel anomalies. For the case of the unperturbed two-body problem, it is proved that if transformations are power functions of the radial variable, only the eccentric and the true anomalies (with the corresponding transformations of the radial variable) will result in harmonic oscillators. The present method significantly reduces computation requirements in autonomous space operations. 11 references.

Four-quark bound states

International Nuclear Information System (INIS)

Zouzou, S.

1986-01-01

In the framework of simple non-relativistic potential models, we examine the system consisting of two quarks and two antiquarks with equal or unequal masses. We search for possible bound states below the threshold for the spontaneous dissociation into two mesons. We solve the four body problem by empirical or systematic variational methods and we include the virtual meson-meson components of the wave function. With standard two-body potentials, there is no proliferation of multiquarks. With unequal quark masses, we obtain however exotic (anti Qanti Qqq) bound states with a baryonic antidiquark-quark-quark structure very analogous to the heavy flavoured (Q'qq) baryons. (orig.)

The four-dimensional mouse whole-body phantoms and its application in medical imaging research

International Nuclear Information System (INIS)

Li Chongguo; Wu Dake

2012-01-01

Medical imaging simulation is a powerful tool for characterizing,evaluating,and optimizing medical imaging devices and techniques. A vital aspect of simulation is to have a realistic phantom or model of the subject's anatomy. Four-dimensional mouse whole-body phantoms provide realistic models of the mouse anatomy and physiology for imaging studies. When combined with accurate models for the imaging process,are capable of providing a wealth of realistic imaging data from subjects with various anatomies and motions (cardiac and respiratory) in health and disease. With this ability, the four-dimensional mouse whole-body phantoms have enormous potential to study the effects of anatomical, physiological and physical factors on medical and small animal imaging and to research new instrumentation, image acquisition strategies, image processing, reconstruction methods, image visualization and interpretation techniques. (authors)

Few-body problem in terms of correlated Gaussians

Science.gov (United States)

Silvestre-Brac, Bernard; Mathieu, Vincent

2007-10-01

In their textbook, Suzuki and Varga [Stochastic Variational Approach to Quantum-Mechanical Few-Body Problems (Springer, Berlin, 1998)] present the stochastic variational method with the correlated Gaussian basis in a very exhaustive way. However, the Fourier transform of these functions and their application to the management of a relativistic kinetic energy operator are missing and cannot be found in the literature. In this paper we present these interesting formulas. We also give a derivation for formulations concerning central potentials.

Low-Thrust Orbital Transfers in the Two-Body Problem

Directory of Open Access Journals (Sweden)

A. A. Sukhanov

2012-01-01

Full Text Available Low-thrust transfers between given orbits within the two-body problem are considered; the thrust is assumed power limited. A simple method for obtaining the transfer trajectories based on the linearization of the motion near reference orbits is suggested. Required calculation accuracy can be reached by means of use of a proper number of the reference orbits. The method may be used in the case of a large number of the orbits around the attracting center; no averaging is necessary in this case. The suggested method also is applicable to the cases of partly given final orbit and if there are constraints on the thrust direction. The method gives an optimal solution to the linearized problem which is not optimal for the original nonlinear problem; the difference between the optimal solutions to the original and linearized problems is estimated using a numerical example. Also examples illustrating the method capacities are given.

Computational Nuclear Quantum Many-Body Problem: The UNEDF Project

OpenAIRE

Bogner, Scott; Bulgac, Aurel; Carlson, Joseph A.; Engel, Jonathan; Fann, George; Furnstahl, Richard J.; Gandolfi, Stefano; Hagen, Gaute; Horoi, Mihai; Johnson, Calvin W.; Kortelainen, Markus; Lusk, Ewing; Maris, Pieter; Nam, Hai Ah; Navratil, Petr

2013-01-01

The UNEDF project was a large-scale collaborative effort that applied high-performance computing to the nuclear quantum many-body problem. UNEDF demonstrated that close associations among nuclear physicists, mathematicians, and computer scientists can lead to novel physics outcomes built on algorithmic innovations and computational developments. This review showcases a wide range of UNEDF science results to illustrate this interplay.

TOPICAL PROBLEMS OF PROVIDING LAWFULNESS IN PRELIMINARY INVESTIGATION BODIES

Directory of Open Access Journals (Sweden)

Elnara Islamova

2015-09-01

Full Text Available This article examines current problems of reviewing crime reports of private prosecution by the preliminary investigation bodies, and the role of the prosecutor in providing lawfulness in this process. Issues are formulated to be clarified by the prosecutor in exercising supervision over the enforcement of the law in the receipt, registration and reviewing of the crime reports of private prosecution.

Dark matter annihilation into four-body final states and implications for the AMS antiproton excess

Science.gov (United States)

Clark, Steven J.; Dutta, Bhaskar; Strigari, Louis E.

2018-01-01

We consider dark matter annihilation into a general set of final states of standard model particles, including two-body and four-body final states that result from the decay of intermediate states. For dark matter masses ˜10 - 105 GeV , we use updated data from Planck and from high gamma-ray experiments such as Fermi-LAT, MAGIC, and VERITAS to constrain the annihilation cross section for each final state. The Planck constraints are the most stringent over the entire mass range for annihilation into light leptons, and the Fermi-LAT constraints are the most stringent for four-body final states up to masses ˜104 GeV . We consider these constraints in light of the recent AMS antiproton results, and show that for light mediators it is possible to explain the AMS data with dark matter, and remain consistent with Fermi-LAT Inner Galaxy measurements, for mχ˜60 - 100 GeV mass dark matter and mediator masses mϕ/mχ≲1 .

Addressing communications between Regulatory Body and TSO: perceptions and problems

International Nuclear Information System (INIS)

Salati de Almeida, I.P.

2007-01-01

The use of TSO assistance by the Regulatory Bodies is a way of facing the complexity of the technology and issues to be dealt with in the licensing and controlling process in the nuclear area. Although both TSO and Regulatory Body are well prepared and adjusted, the nature and environment of TSO work is rather different from the regulators. Some of the TSO members act as a consultant, giving expert advice to the regulators in a specific subject, some are in charge of inspections and audits, others do the job together with the regulators. The way that a TSO member perceives the work to be done, however, often creates different perspectives for questions related to the licensing and controlling process. These perceptions are usually a source of problems between the two partners, regulators and TSO members. In this paper some of this kind of problems are raised and suggestions of how to deal with them are proposed for discussion. (author)

Precise numerical results for limit cycles in the quantum three-body problem

International Nuclear Information System (INIS)

Mohr, R.F.; Furnstahl, R.J.; Hammer, H.-W.; Perry, R.J.; Wilson, K.G.

2006-01-01

The study of the three-body problem with short-range attractive two-body forces has a rich history going back to the 1930s. Recent applications of effective field theory methods to atomic and nuclear physics have produced a much improved understanding of this problem, and we elucidate some of the issues using renormalization group ideas applied to precise nonperturbative calculations. These calculations provide 11-12 digits of precision for the binding energies in the infinite cutoff limit. The method starts with this limit as an approximation to an effective theory and allows cutoff dependence to be systematically computed as an expansion in powers of inverse cutoffs and logarithms of the cutoff. Renormalization of three-body bound states requires a short range three-body interaction, with a coupling that is governed by a precisely mapped limit cycle of the renormalization group. Additional three-body irrelevant interactions must be determined to control subleading dependence on the cutoff and this control is essential for an effective field theory since the continuum limit is not likely to match physical systems (e.g., few-nucleon bound and scattering states at low energy). Leading order calculations precise to 11-12 digits allow clear identification of subleading corrections, but these corrections have not been computed

Energy Analysis in the Elliptic Restricted Three-body Problem

Science.gov (United States)

Qi, Yi; de Ruiter, Anton

2018-05-01

The gravity assist or flyby is investigated by analyzing the inertial energy of a test particle in the elliptic restricted three-body problem (ERTBP), where two primary bodies are moving in elliptic orbits. Firstly, the expression of the derivation of energy is obtained and discussed. Then, the approximate expressions of energy change in a circular neighborhood of the smaller primary are derived. Numerical computation indicates that the obtained expressions can be applied to study the flyby problem of the nine planets and the Moon in the solar system. Parameters related to the flyby are discussed analytically and numerically. The optimal conditions, including the position and time of the periapsis, for a flyby orbit are found to make a maximum energy gain or loss. Finally, the mechanical process of a flyby orbit is uncovered by an approximate expression in the ERTBP. Numerical computations testify that our analytical results well approximate the mechanical process of flyby orbits obtained by the numerical simulation in the ERTBP. Compared with the previous research established in the patched-conic method and numerical calculation, our analytical investigations based on a more elaborate derivation get more original results.

Gender differences dominate sleep disorder patients' body problem complaints

Directory of Open Access Journals (Sweden)

Ted L. Rosenthal

1994-12-01

Full Text Available We studied it age, gender, diagnostic status, and psychiatric features affected 291 consecutive sleep disorder patient's body complaints on a brief checklist. Gender had a strong impact on all four (tested dependent measures, with women reporting more distress than men. Age produced significant regressions on two measures, with younger patients complaining more than older. Presence of psychiatric features was associated with more complaints on one dependent measure - previously found to reflect internal medicine patients' emotional distress. The results of regression analyses were largely supported by follow-up ANOVAs. However, contrasting insomniac versus hypersomniac versus all other sleep disorder diagnoses did not affect body complaints on any dependent measure. The results caution against combining males and females to compare self-reported distress between sleep disorders.

1978 Algerian accident: four cases of protracted whole-body irradiation

International Nuclear Information System (INIS)

Jammet, H.; Gongora, R.; Pouillard, P.; Le Go, R.; Parmentier, N.

1980-01-01

On May 5, 1978 an iridium 192 source of 25 curies for gammagraphy fell from a truck on the road from Algiers to Setif. It was found by two young boys, and later taken away from them by their grandmother who hid it in their kitchen. The source remained about five or six weeks in this room, where four young females received a daily and protracted irradiation. These cases are of particular interest since it is the first observation of accidental irradiation spanning so long a period and for which daily data could be collected during several months. The clinical findings of responses of the hematopoietic system, digestive system, brain, biochemical functionings, and chromosomes are reported. Also included are technical procedures in dosimetry problems related to exposures in these four patients

Modified Strum functions method in the nuclear three body problem

International Nuclear Information System (INIS)

Nasyrov, M.; Abdurakhmanov, A.; Yunusova, M.

1997-01-01

Fadeev-Hahn equations in the nuclear three-body problem were solved by modified Sturm functions method. Numerical calculations were carried out the square well potential. It was shown that the convergence of the method is high and the binding energy value is in agreement with experimental one (A.A.D.)

The three-body problem in quantum mechanics

International Nuclear Information System (INIS)

Antunes, A.C.B.

1973-01-01

Different methods used in the analysis of the scattering of an elementary particle by a system of two bound particles are compared. All particles are considered spinless and distinguishable from each other. Two approaches are used in the treatment of the problem. In the first method we build an effective - potential which accounts for the interaction of the incident particle with the bound system. The second approach consists in treating the target as a system of two particles, whose momentum distribution is given by the bound state wavefunction. The three body system is then treated by the techniques of the multiple scattering series and of Glauber theory. (author)

Comparison of four approaches to a rock facies classification problem

Science.gov (United States)

Dubois, M.K.; Bohling, Geoffrey C.; Chakrabarti, S.

2007-01-01

In this study, seven classifiers based on four different approaches were tested in a rock facies classification problem: classical parametric methods using Bayes' rule, and non-parametric methods using fuzzy logic, k-nearest neighbor, and feed forward-back propagating artificial neural network. Determining the most effective classifier for geologic facies prediction in wells without cores in the Panoma gas field, in Southwest Kansas, was the objective. Study data include 3600 samples with known rock facies class (from core) with each sample having either four or five measured properties (wire-line log curves), and two derived geologic properties (geologic constraining variables). The sample set was divided into two subsets, one for training and one for testing the ability of the trained classifier to correctly assign classes. Artificial neural networks clearly outperformed all other classifiers and are effective tools for this particular classification problem. Classical parametric models were inadequate due to the nature of the predictor variables (high dimensional and not linearly correlated), and feature space of the classes (overlapping). The other non-parametric methods tested, k-nearest neighbor and fuzzy logic, would need considerable improvement to match the neural network effectiveness, but further work, possibly combining certain aspects of the three non-parametric methods, may be justified. ?? 2006 Elsevier Ltd. All rights reserved.

Parallel Implementation of Numerical Solution of Few-Body Problem Using Feynman's Continual Integrals

Science.gov (United States)

Naumenko, Mikhail; Samarin, Viacheslav

2018-02-01

Modern parallel computing algorithm has been applied to the solution of the few-body problem. The approach is based on Feynman's continual integrals method implemented in C++ programming language using NVIDIA CUDA technology. A wide range of 3-body and 4-body bound systems has been considered including nuclei described as consisting of protons and neutrons (e.g., 3,4He) and nuclei described as consisting of clusters and nucleons (e.g., 6He). The correctness of the results was checked by the comparison with the exactly solvable 4-body oscillatory system and experimental data.

Equilibrium Solutions of the Logarithmic Hamiltonian Leapfrog for the N-body Problem

Science.gov (United States)

Minesaki, Yukitaka

2018-04-01

We prove that a second-order logarithmic Hamiltonian leapfrog for the classical general N-body problem (CGNBP) designed by Mikkola and Tanikawa and some higher-order logarithmic Hamiltonian methods based on symmetric multicompositions of the logarithmic algorithm exactly reproduce the orbits of elliptic relative equilibrium solutions in the original CGNBP. These methods are explicit symplectic methods. Before this proof, only some implicit discrete-time CGNBPs proposed by Minesaki had been analytically shown to trace the orbits of elliptic relative equilibrium solutions. The proof is therefore the first existence proof for explicit symplectic methods. Such logarithmic Hamiltonian methods with a variable time step can also precisely retain periodic orbits in the classical general three-body problem, which generic numerical methods with a constant time step cannot do.

Muonic molecules as three-body Coulomb problem in adiabatic approximation

International Nuclear Information System (INIS)

Decker, M.

1994-04-01

The three-body Coulomb problem is treated within the framework of the hyperspherical adiabatic approach. The surface functions are expanded into Faddeev-type components in order to ensure the equivalent representation of all possible two-body contributions. It is shown that this decomposition reduces the numerical effort considerably. The remaining radial equations are solved both in the extreme and the uncoupled adiabatic approximation to determine the binding energies of the systems (dtμ) and (d 3 Heμ). Whereas the ground state is described very well in the uncoupled adiabatic approximation, the excited states should be treated within the coupled adiabatic approximation to obtain good agreement with variational calculations. (orig.)

Unitary pole approximations and expansions in few-body systems

International Nuclear Information System (INIS)

Casel, A.; Haberzettl, H.; Sandhas, W.

1982-01-01

The unitary pole approximations or expansions of the two-body subsystem operators are well known, and particularly efficient and practical, methods to reduce the three-body problem to an effective two-body theory. In the present investigation we develop generalizations of these approximation techniques to the subsystem amplitudes of problems with higher particle numbers. They are based on the expansion of effective potentials which, in contrast to the genuine two-body interactions, are now energy dependent. Despite this feature our generalizations require only energy independent form factors, thus preserving one of the essential advantages of the genuine two-body approach. The application of these techniques to the four-body case is discussed in detail

Genuine Four Tangle for Four Qubit States

OpenAIRE

Sharma, S. Shelly; Sharma, N. K.

2013-01-01

We report a four qubit polynomial invariant that quantifies genuine four-body correlations. The four qubit invariants are obtained from transformation properties of three qubit invariants under a local unitary on the fourth qubit.

Testing the nature of neutrinos from four-body τ decays

Science.gov (United States)

Yuan, Han; Jiang, Yue; Wang, Tian-hong; Li, Qiang; Wang, Guo-Li

2017-11-01

This paper discusses four-body lepton number violating tau decay. We study the processes {τ }+\\to {e}+{e}+{π }-{\\bar{ν }}τ and {τ }+\\to {e}+{e}+{π }-{ν }e to determine the nature of the neutrino. The first process violates the lepton number by two units, which can only happen through an internal Majorana. The second one conserves the lepton number but violates the lepton flavor, which can take place with both a Majorana neutrino and a Dirac neutrino. We calculate their branching ratio (BR) and differential BR {{d}}{B}{R}/{{{d}}{E}}π to distinguish between the Majorana neutrino and the Dirac neutrino. We also propose an experiment to perform this detection.

Disease-related malnutrition: influence on body composition and prognosis

OpenAIRE

Pirlich, Matthias

2010-01-01

Disease-related malnutrition is a frequent clincal problem with severe medical and economic impact. This work summarizes studies on body composition analysis, risk factors, prevalence and prognostic impact of malnutrition. The diagnosis of malnutrition in patients with chronic liver disease is hampered by hyperhydration and requires body composition analysis. Using four different methods for body composition analysis (total body potassium counting, anthropometry, bioelectrical impedance analy...

Global solutions to the electrodynamic two-body problem on a straight line

Science.gov (United States)

Bauer, G.; Deckert, D.-A.; Dürr, D.; Hinrichs, G.

2017-06-01

The classical electrodynamic two-body problem has been a long standing open problem in mathematics. For motion constrained to the straight line, the interaction is similar to that of the two-body problem of classical gravitation. The additional complication is the presence of unbounded state-dependent delays in the Coulomb forces due to the finiteness of the speed of light. This circumstance renders the notion of local solutions meaningless, and therefore, straightforward ODE techniques cannot be applied. Here, we study the time-symmetric case, i.e., the Fokker-Schwarzschild-Tetrode (FST) equations, comprising both advanced and retarded delays. We extend the technique developed in Deckert and Hinrichs (J Differ Equ 260:6900-6929, 2016), where existence of FST solutions was proven on the half line, to ensure global existence—a result that had been obtained by Bauer (Ein Existenzsatz für die Wheeler-Feynman-Elektrodynamik, Herbert Utz Verlag, München, 1997). Due to the novel technique, the presented proof is shorter and more transparent but also relies on the idea to employ asymptotic data to characterize solutions.

Paradeisos: A perfect hashing algorithm for many-body eigenvalue problems

Science.gov (United States)

Jia, C. J.; Wang, Y.; Mendl, C. B.; Moritz, B.; Devereaux, T. P.

2018-03-01

We describe an essentially perfect hashing algorithm for calculating the position of an element in an ordered list, appropriate for the construction and manipulation of many-body Hamiltonian, sparse matrices. Each element of the list corresponds to an integer value whose binary representation reflects the occupation of single-particle basis states for each element in the many-body Hilbert space. The algorithm replaces conventional methods, such as binary search, for locating the elements of the ordered list, eliminating the need to store the integer representation for each element, without increasing the computational complexity. Combined with the "checkerboard" decomposition of the Hamiltonian matrix for distribution over parallel computing environments, this leads to a substantial savings in aggregate memory. While the algorithm can be applied broadly to many-body, correlated problems, we demonstrate its utility in reducing total memory consumption for a series of fermionic single-band Hubbard model calculations on small clusters with progressively larger Hilbert space dimension.

Coulomb effects in deuteron stripping reactions as a three-body problem

International Nuclear Information System (INIS)

Osman, A.

1981-08-01

Deuteron stripping nuclear reactions are reconsidered as a three-body problem. The Coulomb effects between the proton and the target nucleus are investigated. The mathematical formalism introduces three-body integral equations which can be exactly calculated for such simple models. These coupled integral equations suitably include the Coulomb effects due to replusive or attractive Coulomb potential. Numerical calculations of the differential cross-sections of the reactions 28 Si(d,p) 29 Si and 40 Ca(d,p) 41 Ca are carried out showing the importance of the Coulomb effects. The angular distributions of these reactions are theoretically calculated and fitted to the experimental data. From this fitting, reasonable spectroscopic factors are obtained. Inclusion of Coulomb force in the three-body model are found to improve the results by a percentage of about 6.826%. (author)

Body size and lean mass of brown bears across and within four diverse ecosystems

Science.gov (United States)

Hilderbrand, Grant V.; Gustine, David; Mangipane, Buck A.; Joly, Kyle; Leacock, William; Mangipane, Lindsey S.; Erlenbach, Joy; Sorum, Mathew; Cameron, Matthew; Belant, Jerrold L.; Cambier, Troy

2018-01-01

Variation in body size across populations of brown bears (Ursus arctos) is largely a function of the availability and quality of nutritional resources while plasticity within populations reflects utilized niche width with implications for population resiliency. We assessed skull size, body length, and lean mass of adult female and male brown bears in four Alaskan study areas that differed in climate, primary food resources, population density, and harvest regime. Full body-frame size, as evidenced by asymptotic skull size and body length, was achieved by 8 to 14 years of age across populations and sexes. Lean body mass of both sexes continued to increase throughout their life. Differences between populations existed for all morphological measures in both sexes, bears in ecosystems with abundant salmon were generally larger. Within all populations, broad variation was seen in body size measures of adults with females displaying roughly a 2-fold difference in lean mass and males showing a 3- to 4-fold difference. The high level of intraspecific variation seen across and within populations suggests the presence of multiple life-history strategies and niche variation relative to resource partitioning, risk tolerance or aversion, and competition. Further, this level of variation indicates broad potential to adapt to changes within a given ecosystem and across the species’ range.

Three-body scattering problem in the fixed center approximation: The case of attraction

Energy Technology Data Exchange (ETDEWEB)

Kudryavtsev, Alexander E. [National Research Center Kurchatov Institute, Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Gani, Vakhid A. [National Research Center Kurchatov Institute, Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation); Romanov, Alexander I. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation)

2016-12-15

We study the scattering of a light particle on a bound pair of heavy particles (e.g., the deuteron) within the fixed center approximation in the case of light-heavy attraction, solving the integral equation for the three-body Green's function both in the coordinate and in the momentum space. The results for the three-body scattering amplitude appear to be ambiguous -they depend on a single real parameter. This parameter may be fixed by a three-body input, e.g., the three-body scattering length. We also solve the integral equation for the three-body Green function in the momentum space, introducing a finite cut-off. We show that all three approaches are equivalent. We also discuss how our approach to the problem matches with the introduction of three-body contact interaction as done by other authors. (orig.)

A four-body potential in multiquark states

International Nuclear Information System (INIS)

Warner, R.C.; Joshi, G.C.

1980-01-01

A detailed analysis is presented of the first member of a previously derived hierarchy of instanton generated many-body potentials for multiquark states. Comparison with two-body instanton generated potential in the heavy quark framework is made in the T-baryonium system

Antisymmetrized four-body wave function and coexistence of single particle and cluster structures

International Nuclear Information System (INIS)

Sasakawa, T.

1979-01-01

It is shown that each Yakubovski component of the totally antisymmetric four-body wave function satisfies the same equation as the unantisymmetric wave function. In the antisymmetric total wave function, the wave functions belonging to the same kind of partition are totally antisymmetric among themselves. This leads to the coexistence of cluster models, including the single particle model as a special case of the cluster model, as a sum

The human body and weightlessness operational effects, problems and countermeasures

CERN Document Server

Thornton, William

2017-01-01

This book focuses on all of the major problems associated with the absence of body weight in space, by analyzing effects, adaption, and re-adaptation upon returning to Earth, using sound scientific principles embedded in a historical context. Serious problems for space travelers range from Space Motion Sickness (SMS) to recently discovered ocular effects that may permanently impair vision. Fluid loss and shifts, spinal changes, and bone and muscle loss are also all results of weightlessness. Starting with a brief definition and history of weightlessness, the authors then address in detail each problem as well as the countermeasures aimed at alleviating them. In some cases, alternative hypotheses regarding what can and should be attempted are also presented. As plans for long-term missions to the Moon and Mars develop, it will be essential to find countermeasures to weightlessness that are effective for missions that could span years.

The quantum n-body problem in dimension d ⩾ n – 1: ground state

Science.gov (United States)

Miller, Willard, Jr.; Turbiner, Alexander V.; Escobar-Ruiz, M. A.

2018-05-01

We employ generalized Euler coordinates for the n body system in dimensional space, which consists of the centre-of-mass vector, relative (mutual) mass-independent distances r ij and angles as remaining coordinates. We prove that the kinetic energy of the quantum n-body problem for can be written as the sum of three terms: (i) kinetic energy of centre-of-mass, (ii) the second order differential operator which depends on relative distances alone and (iii) the differential operator which annihilates any angle-independent function. The operator has a large reflection symmetry group and in variables is an algebraic operator, which can be written in terms of generators of the hidden algebra . Thus, makes sense of the Hamiltonian of a quantum Euler–Arnold top in a constant magnetic field. It is conjectured that for any n, the similarity-transformed is the Laplace–Beltrami operator plus (effective) potential; thus, it describes a -dimensional quantum particle in curved space. This was verified for . After de-quantization the similarity-transformed becomes the Hamiltonian of the classical top with variable tensor of inertia in an external potential. This approach allows a reduction of the dn-dimensional spectral problem to a -dimensional spectral problem if the eigenfunctions depend only on relative distances. We prove that the ground state function of the n body problem depends on relative distances alone.

Graphs and an exactly solvable N-body problem in one dimension

Energy Technology Data Exchange (ETDEWEB)

Barucchi, G [Turin Univ. (Italy). Ist. di Fisica Matematica

1980-08-21

The one-dimensional N-body classical problem with inversely quadratic pair potential is considered. A method of explicit construction, by means of graphs, of the constants of the motion is given. It is then shown how to obtain, by means of a computer, the position variables of the particles as numerical functions of time.

Lattice Methods and the Nuclear Few- and Many-Body Problem

Science.gov (United States)

Lee, Dean

This chapter builds upon the review of lattice methods and effective field theory of the previous chapter. We begin with a brief overview of lattice calculations using chiral effective field theory and some recent applications. We then describe several methods for computing scattering on the lattice. After that we focus on the main goal, explaining the theory and algorithms relevant to lattice simulations of nuclear few- and many-body systems. We discuss the exact equivalence of four different lattice formalisms, the Grassmann path integral, transfer matrix operator, Grassmann path integral with auxiliary fields, and transfer matrix operator with auxiliary fields. Along with our analysis we include several coding examples and a number of exercises for the calculations of few- and many-body systems at leading order in chiral effective field theory.

Three-body problem in d-dimensional space: Ground state, (quasi)-exact-solvability

Science.gov (United States)

Turbiner, Alexander V.; Miller, Willard; Escobar-Ruiz, M. A.

2018-02-01

As a straightforward generalization and extension of our previous paper [A. V. Turbiner et al., "Three-body problem in 3D space: Ground state, (quasi)-exact-solvability," J. Phys. A: Math. Theor. 50, 215201 (2017)], we study the aspects of the quantum and classical dynamics of a 3-body system with equal masses, each body with d degrees of freedom, with interaction depending only on mutual (relative) distances. The study is restricted to solutions in the space of relative motion which are functions of mutual (relative) distances only. It is shown that the ground state (and some other states) in the quantum case and the planar trajectories (which are in the interaction plane) in the classical case are of this type. The quantum (and classical) Hamiltonian for which these states are eigenfunctions is derived. It corresponds to a three-dimensional quantum particle moving in a curved space with special d-dimension-independent metric in a certain d-dependent singular potential, while at d = 1, it elegantly degenerates to a two-dimensional particle moving in flat space. It admits a description in terms of pure geometrical characteristics of the interaction triangle which is defined by the three relative distances. The kinetic energy of the system is d-independent; it has a hidden sl(4, R) Lie (Poisson) algebra structure, alternatively, the hidden algebra h(3) typical for the H3 Calogero model as in the d = 3 case. We find an exactly solvable three-body S3-permutationally invariant, generalized harmonic oscillator-type potential as well as a quasi-exactly solvable three-body sextic polynomial type potential with singular terms. For both models, an extra first order integral exists. For d = 1, the whole family of 3-body (two-dimensional) Calogero-Moser-Sutherland systems as well as the Tremblay-Turbiner-Winternitz model is reproduced. It is shown that a straightforward generalization of the 3-body (rational) Calogero model to d > 1 leads to two primitive quasi

Method for solving the problem of nonlinear heating a cylindrical body with unknown initial temperature

Science.gov (United States)

Yaparova, N.

2017-10-01

We consider the problem of heating a cylindrical body with an internal thermal source when the main characteristics of the material such as specific heat, thermal conductivity and material density depend on the temperature at each point of the body. We can control the surface temperature and the heat flow from the surface inside the cylinder, but it is impossible to measure the temperature on axis and the initial temperature in the entire body. This problem is associated with the temperature measurement challenge and appears in non-destructive testing, in thermal monitoring of heat treatment and technical diagnostics of operating equipment. The mathematical model of heating is represented as nonlinear parabolic PDE with the unknown initial condition. In this problem, both the Dirichlet and Neumann boundary conditions are given and it is required to calculate the temperature values at the internal points of the body. To solve this problem, we propose the numerical method based on using of finite-difference equations and a regularization technique. The computational scheme involves solving the problem at each spatial step. As a result, we obtain the temperature function at each internal point of the cylinder beginning from the surface down to the axis. The application of the regularization technique ensures the stability of the scheme and allows us to significantly simplify the computational procedure. We investigate the stability of the computational scheme and prove the dependence of the stability on the discretization steps and error level of the measurement results. To obtain the experimental temperature error estimates, computational experiments were carried out. The computational results are consistent with the theoretical error estimates and confirm the efficiency and reliability of the proposed computational scheme.

Parallel Implementation of Numerical Solution of Few-Body Problem Using Feynman’s Continual Integrals

Directory of Open Access Journals (Sweden)

Naumenko Mikhail

2018-01-01

Full Text Available Modern parallel computing algorithm has been applied to the solution of the few-body problem. The approach is based on Feynman’s continual integrals method implemented in C++ programming language using NVIDIA CUDA technology. A wide range of 3-body and 4-body bound systems has been considered including nuclei described as consisting of protons and neutrons (e.g., 3,4He and nuclei described as consisting of clusters and nucleons (e.g., 6He. The correctness of the results was checked by the comparison with the exactly solvable 4-body oscillatory system and experimental data.

Method of hyperspherical functions in a few-body quantum mechanics

International Nuclear Information System (INIS)

Dzhibuti, R.I.; Krupennikova, N.B.

1984-01-01

A new method for solving a few-body problem in quantum mechanics based on the expansion of the wave function of many-particle system in terms of basis hyperspherical functions is outlined in the monograph. This method gives the possibility to obtain important results in nuclear physics. A materials of general character is presented which can be useful when considering a few-body problem in atomic and molecular physics as well as in elementary particle physics. The paper deals with the theory of hyperspherical functions and the method of expansion in terms of hyperspherical functions basis can be formally considered as a certain generalization of the partial expansion method in the two-body problem. The Raynal-Revai theory is stated for the three-body problem and coe-- fficients of unitary transformations for four-particle hyperspherical function coefficients are introduced. Five-particle hyperspherical functions are introduced and an attempt of generalization of the theory for the systems With any number of particles has been made. The rules of plotting symmetrized hyperspherical functions for three and four identical particles are given. Also described is the method of expansion in terms of hyperspherical functions basis in the coordinate and impulse representations for discrete and continuous spectrum, respectively

The mass-damped Riemann problem and the aerodynamic surface force calculation for an accelerating body

International Nuclear Information System (INIS)

Tan, Zhiqiang; Wilson, D.; Varghese, P.L.

1997-01-01

We consider an extension of the ordinary Riemann problem and present an efficient approximate solution that can be used to improve the calculations of aerodynamic forces on an accelerating body. The method is demonstrated with one-dimensional examples where the Euler equations and the body motion are solved in the non-inertial co-ordinate frame fixed to the accelerating body. 8 refs., 6 figs

Semiclassical expansion of quantum characteristics for many-body potential scattering problem

International Nuclear Information System (INIS)

Krivoruchenko, M.I.; Fuchs, C.; Faessler, A.

2007-01-01

In quantum mechanics, systems can be described in phase space in terms of the Wigner function and the star-product operation. Quantum characteristics, which appear in the Heisenberg picture as the Weyl's symbols of operators of canonical coordinates and momenta, can be used to solve the evolution equations for symbols of other operators acting in the Hilbert space. To any fixed order in the Planck's constant, many-body potential scattering problem simplifies to a statistical-mechanical problem of computing an ensemble of quantum characteristics and their derivatives with respect to the initial canonical coordinates and momenta. The reduction to a system of ordinary differential equations pertains rigorously at any fixed order in ℎ. We present semiclassical expansion of quantum characteristics for many-body scattering problem and provide tools for calculation of average values of time-dependent physical observables and cross sections. The method of quantum characteristics admits the consistent incorporation of specific quantum effects, such as non-locality and coherence in propagation of particles, into the semiclassical transport models. We formulate the principle of stationary action for quantum Hamilton's equations and give quantum-mechanical extensions of the Liouville theorem on conservation of the phase-space volume and the Poincare theorem on conservation of 2p-forms. The lowest order quantum corrections to the Kepler periodic orbits are constructed. These corrections show the resonance behavior. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

Four-body correlation embedded in antisymmetrized geminal power wave function.

Science.gov (United States)

Kawasaki, Airi; Sugino, Osamu

2016-12-28

We extend the Coleman's antisymmetrized geminal power (AGP) to develop a wave function theory that can incorporate up to four-body correlation in a region of strong correlation. To facilitate the variational determination of the wave function, the total energy is rewritten in terms of the traces of geminals. This novel trace formula is applied to a simple model system consisting of one dimensional Hubbard ring with a site of strong correlation. Our scheme significantly improves the result obtained by the AGP-configuration interaction scheme of Uemura et al. and also achieves more efficient compression of the degrees of freedom of the wave function. We regard the result as a step toward a first-principles wave function theory for a strongly correlated point defect or adsorbate embedded in an AGP-based mean-field medium.

Three-body problem in quantum mechanics: Hyperspherical elliptic coordinates and harmonic basis sets

International Nuclear Information System (INIS)

Aquilanti, Vincenzo; Tonzani, Stefano

2004-01-01

Elliptic coordinates within the hyperspherical formalism for three-body problems were proposed some time ago [V. Aquilanti, S. Cavalli, and G. Grossi, J. Chem. Phys. 85, 1362 (1986)] and recently have also found application, for example, in chemical reaction theory [see O. I. Tolstikhin and H. Nakamura, J. Chem. Phys. 108, 8899 (1998)]. Here we consider their role in providing a smooth transition between the known 'symmetric' and 'asymmetric' parametrizations, and focus on the corresponding hyperspherical harmonics. These harmonics, which will be called hyperspherical elliptic, involve products of two associated Lame polynomials. We will provide an expansion of these new sets in a finite series of standard hyperspherical harmonics, producing a powerful tool for future applications in the field of scattering and bound-state quantum-mechanical three-body problems

The quantum mechanics of many-body systems

CERN Document Server

Thouless, David James; Brueckner, Keith A

1961-01-01

The Quantum Mechanics of Many-Body Systems provides an introduction to that field of theoretical physics known as """"many-body theory."""" It is concerned with problems that are common to nuclear physics, atomic physics, the electron theory of metals, and to the theories of liquid helium three and four, and it describes the methods which have recently been developed to solve such problems. The aim has been to produce a unified account of the field, rather than to describe all the parallel methods that have been developed; as a result, a number of important papers are not mentioned. The main

Resonating-group method for nuclear many-body problems

International Nuclear Information System (INIS)

Tang, Y.C.; LeMere, M.; Thompson, D.R.

1977-01-01

The resonating-group method is a microscopic method which uses fully antisymmetric wave functions, treats correctly the motion of the total center of mass, and takes cluster correlation into consideration. In this review, the formulation of this method is discussed for various nuclear many-body problems, and a complex-generator-coordinate technique which has been employed to evaluate matrix elements required in resonating-group calculations is described. Several illustrative examples of bound-state, scattering, and reaction calculations, which serve to demonstrate the usefulness of this method, are presented. Finally, by utilization of the results of these calculations, the role played by the Pauli principle in nuclear scattering and reaction processes is discussed. 21 figures, 2 tables, 185 references

Solving the three-body Coulomb breakup problem using exterior complex scaling

Energy Technology Data Exchange (ETDEWEB)

McCurdy, C.W.; Baertschy, M.; Rescigno, T.N.

2004-05-17

Electron-impact ionization of the hydrogen atom is the prototypical three-body Coulomb breakup problem in quantum mechanics. The combination of subtle correlation effects and the difficult boundary conditions required to describe two electrons in the continuum have made this one of the outstanding challenges of atomic physics. A complete solution of this problem in the form of a ''reduction to computation'' of all aspects of the physics is given by the application of exterior complex scaling, a modern variant of the mathematical tool of analytic continuation of the electronic coordinates into the complex plane that was used historically to establish the formal analytic properties of the scattering matrix. This review first discusses the essential difficulties of the three-body Coulomb breakup problem in quantum mechanics. It then describes the formal basis of exterior complex scaling of electronic coordinates as well as the details of its numerical implementation using a variety of methods including finite difference, finite elements, discrete variable representations, and B-splines. Given these numerical implementations of exterior complex scaling, the scattering wave function can be generated with arbitrary accuracy on any finite volume in the space of electronic coordinates, but there remains the fundamental problem of extracting the breakup amplitudes from it. Methods are described for evaluating these amplitudes. The question of the volume-dependent overall phase that appears in the formal theory of ionization is resolved. A summary is presented of accurate results that have been obtained for the case of electron-impact ionization of hydrogen as well as a discussion of applications to the double photoionization of helium.

Stability of orbits around a spinning body in a pseudo-Newtonian Hill problem

International Nuclear Information System (INIS)

Steklain, A.F.; Letelier, P.S.

2009-01-01

A pseudo-Newtonian Hill problem based on a potential proposed by Artemova et al. [I.A. Artemova, G. Bjoernsson, I.D. Novikov, Astrophys. J. 461 (1996) 565] is presented. This potential reproduces some of the general relativistic effects due to the spin angular momentum of the bodies, like the dragging of inertial frames. Poincare maps, Lyapunov exponents and fractal escape techniques are employed to study the stability of bounded and unbounded orbits for different spins of the central body

A complete basis for a perturbation expansion of the general N-body problem

International Nuclear Information System (INIS)

Laing, W Blake; Kelle, David W; Dunn, Martin; Watson, Deborah K

2009-01-01

We discuss a basis set developed to calculate perturbation coefficients in an expansion of the general N-body problem. This basis has two advantages. First, the basis is complete order-by-order for the perturbation series. Second, the number of independent basis tensors spanning the space for a given order does not scale with N, the number of particles, despite the generality of the problem. At first order, the number of basis tensors is 25 for all N, i.e. the problem scales as N 0 , although one would initially expect an N 6 scaling at first order. The perturbation series is expanded in inverse powers of the spatial dimension. This results in a maximally symmetric configuration at lowest order which has a point group isomorphic with the symmetric group, S N . The resulting perturbation series is order-by-order invariant under the N! operations of the S N point group which is responsible for the slower than exponential growth of the basis. In this paper, we demonstrate the completeness of the basis and perform the first test of this formalism through first order by comparing to an exactly solvable fully interacting problem of N particles with a two-body harmonic interaction potential

Computational nuclear quantum many-body problem: The UNEDF project

Science.gov (United States)

Bogner, S.; Bulgac, A.; Carlson, J.; Engel, J.; Fann, G.; Furnstahl, R. J.; Gandolfi, S.; Hagen, G.; Horoi, M.; Johnson, C.; Kortelainen, M.; Lusk, E.; Maris, P.; Nam, H.; Navratil, P.; Nazarewicz, W.; Ng, E.; Nobre, G. P. A.; Ormand, E.; Papenbrock, T.; Pei, J.; Pieper, S. C.; Quaglioni, S.; Roche, K. J.; Sarich, J.; Schunck, N.; Sosonkina, M.; Terasaki, J.; Thompson, I.; Vary, J. P.; Wild, S. M.

2013-10-01

The UNEDF project was a large-scale collaborative effort that applied high-performance computing to the nuclear quantum many-body problem. The primary focus of the project was on constructing, validating, and applying an optimized nuclear energy density functional, which entailed a wide range of pioneering developments in microscopic nuclear structure and reactions, algorithms, high-performance computing, and uncertainty quantification. UNEDF demonstrated that close associations among nuclear physicists, mathematicians, and computer scientists can lead to novel physics outcomes built on algorithmic innovations and computational developments. This review showcases a wide range of UNEDF science results to illustrate this interplay.

Foreign body in the vagina of a four-year-old-girl: a childish prank or sexual abuse.

Science.gov (United States)

Sakhavar, Nahid; Teimoori, Batool; Ghasemi, Marzie

2014-06-01

Foreign body in the vagina is a common cause of vaginal discharge, which may be either purulent or hemorrhagic. This problem may produce symptoms or be asymptomatic for long periods of time and may result from ignorance, accident, malice, psychotic tendencies, attempts at sexual stimulation or sexual abuse. The current report presents the case of a girl that had inserted a foreign body in her vagina probably due to childish prank. The clinicians should always think of foreign bodies in the vagina in cases of chronic, antibiotic resistant vaginal discharge and lower abdominal pain especially in young girls.

Four cases of protracted whole body irradiation (Algerian accident 1978)

International Nuclear Information System (INIS)

Jammet, H.; Gongora, R.; Pouillart, P.; Le Go, R.; Parmentier, N.

1979-01-01

A 25 Ci iridium-192 source accidentally lost was introduced in a room where among others four young female patients (14 - 20 years old) one of them pregnant were irradiated during 4/5 weeks, 6/8 hours daily, cumulating skin doses in the range of 2500r and mean medullary doses in the range of 1250r. They developed a very protracted infections and haemorragic syndrome during which they were treated successfully by haematologic compensatory therapy with enormous quantities of packed isolated blood cells (R.B.C., W.B.C., platelets) and massive antibiotic, antimycotic and hydro-electrolytic therapy. The dosimetric (physical and biological) problems are discussed and the clinical and biological data are given in detail

Electron induced break-up of helium. Benchmark experiments on a dynamical four-body Coulomb system

International Nuclear Information System (INIS)

Duerr, M.

2006-01-01

This work presents an experimental study of fragmentation of helium by electron impact, in which absolute fully differential cross sections for single ionization, ionization-excitation and double ionization were determined. By applying a charged-particle imaging technique, the so-called 'reaction microscope', a large fraction of the final-state momentum space is covered, and the major limitations of previous experimental methods applied in this field could be overcome. Decisive modifications of the previous reaction microscope were undertaken, the most important one being the arrangement of the projectile beam parallel to the imaging-fields. For single ionization on helium an enhanced electron emission outside the projectile scattering plane is observed at both considered impact energies (102 eV and 1 keV), which is similar to the result found for ion-impact (M. Schulz et al., Nature (London) 422, 48 (2003)). The angle resolved cross sections obtained for double ionization at 105 eV impact energy reveal, that the process is dominated by the mutual repulsion of the three final-state continuum electrons. However, signatures of more complex dynamics are also observed. The data provide an ultimate benchmark for recently developed theories treating the dynamical three- and four-body Coulomb problem. (orig.)

Electron induced break-up of helium. Benchmark experiments on a dynamical four-body Coulomb system

Energy Technology Data Exchange (ETDEWEB)

Duerr, M.

2006-07-05

This work presents an experimental study of fragmentation of helium by electron impact, in which absolute fully differential cross sections for single ionization, ionization-excitation and double ionization were determined. By applying a charged-particle imaging technique, the so-called 'reaction microscope', a large fraction of the final-state momentum space is covered, and the major limitations of previous experimental methods applied in this field could be overcome. Decisive modifications of the previous reaction microscope were undertaken, the most important one being the arrangement of the projectile beam parallel to the imaging-fields. For single ionization on helium an enhanced electron emission outside the projectile scattering plane is observed at both considered impact energies (102 eV and 1 keV), which is similar to the result found for ion-impact (M. Schulz et al., Nature (London) 422, 48 (2003)). The angle resolved cross sections obtained for double ionization at 105 eV impact energy reveal, that the process is dominated by the mutual repulsion of the three final-state continuum electrons. However, signatures of more complex dynamics are also observed. The data provide an ultimate benchmark for recently developed theories treating the dynamical three- and four-body Coulomb problem. (orig.)

Approximate Coulomb effects in the three-body scattering problem

International Nuclear Information System (INIS)

Haftel, M.I.; Zankel, H.

1981-01-01

From the momentum space Faddeev equations we derive approximate expressions which describe the Coulomb-nuclear interference in the three-body elastic scattering, rearrangement, and breakup problems and apply the formalism to p-d elastic scattering. The approximations treat the Coulomb interference as mainly a two-body effect, but we allow for the charge distribution of the deuteron in the p-d calculations. Real and imaginary parts of the Coulomb correction to the elastic scattering phase shifts are described in terms of on-shell quantities only. In the case of pure Coulomb breakup we recover the distorted-wave Born approximation result. Comparing the derived approximation with the full Faddeev p-d elastic scattering calculation, which includes the Coulomb force, we obtain good qualitative agreement in S and P waves, but disagreement in repulsive higher partial waves. The on-shell approximation investigated is found to be superior to other current approximations. The calculated differential cross sections at 10 MeV raise the question of whether there is a significant Coulomb-nuclear interference at backward angles

Stress Reduction and Mood Enhancement in Four Exercise Modes: Swimming, Body Conditioning, Hatha Yoga, and Fencing.

Science.gov (United States)

Berger, Bonnie G.; Owen, David R.

1988-01-01

Differences in mood before and after class of college students taking different courses (swimming, body conditioning, hatha yoga, fencing exercise, and lecture) were analyzed using the Profile Mood States and the State Anxiety Inventory. Results suggest that courses which meet four requirements involving aerobics, noncompetitiveness,…

Reply to C. M. Will on the axially symmetric two-body problem in general relativity

International Nuclear Information System (INIS)

Cooperstock, F.I.; Lim, P.H.

1985-01-01

The recent paper by Will (1983) is considered which purports to demonstrate that the gravitational radiation which the authors had computed from their model two-body free-fall system is consistent with the so-called quadrupole formula. It is shown that in fact the system presented by Will is different from the authors and that the illegitimate application of the quadrupole formula to the authors system leads to a smaller flux than that which is correctly deduced using general relativity and a proper consideration of nonlinearities. It is demonstrated that a judicious choice of stress release is propagated through the bodies as a superposition of plane and spherical waves leading to pressure fluctuations to the order in question. This underlines the essential distinction between the authors problem and the Will problem. Various aspects of the problem are also discussed. 25 references

The inverse problem of brain energetics: ketone bodies as alternative substrates

Energy Technology Data Exchange (ETDEWEB)

Calvetti, D; Occhipinti, R [Case Western Reserve University, Department of Mathematics, 10900 Euclid Avenue, Cleveland, OH 44106 (United States); Somersalo, E [Helsinki University of Technology, Institute of Mathematics, P. O. Box 1100, FIN-02015 HUT (Finland)], E-mail: daniela.calvetti@case.edu, E-mail: rossana.occhipinti@case.edu, E-mail: erkki.somersalo@tkk.fi

2008-07-15

Little is known about brain energy metabolism under ketosis, although there is evidence that ketone bodies have a neuroprotective role in several neurological disorders. We investigate the inverse problem of estimating reaction fluxes and transport rates in the different cellular compartments of the brain, when the data amounts to a few measured arterial venous concentration differences. By using a recently developed methodology to perform Bayesian Flux Balance Analysis and a new five compartment model of the astrocyte-glutamatergic neuron cellular complex, we are able to identify the preferred biochemical pathways during shortage of glucose and in the presence of ketone bodies in the arterial blood. The analysis is performed in a minimally biased way, therefore revealing the potential of this methodology for hypothesis testing.

The inverse problem of brain energetics: ketone bodies as alternative substrates

International Nuclear Information System (INIS)

Calvetti, D; Occhipinti, R; Somersalo, E

2008-01-01

Little is known about brain energy metabolism under ketosis, although there is evidence that ketone bodies have a neuroprotective role in several neurological disorders. We investigate the inverse problem of estimating reaction fluxes and transport rates in the different cellular compartments of the brain, when the data amounts to a few measured arterial venous concentration differences. By using a recently developed methodology to perform Bayesian Flux Balance Analysis and a new five compartment model of the astrocyte-glutamatergic neuron cellular complex, we are able to identify the preferred biochemical pathways during shortage of glucose and in the presence of ketone bodies in the arterial blood. The analysis is performed in a minimally biased way, therefore revealing the potential of this methodology for hypothesis testing

The inverse problem of brain energetics: ketone bodies as alternative substrates

Science.gov (United States)

Calvetti, D.; Occhipinti, R.; Somersalo, E.

2008-07-01

Little is known about brain energy metabolism under ketosis, although there is evidence that ketone bodies have a neuroprotective role in several neurological disorders. We investigate the inverse problem of estimating reaction fluxes and transport rates in the different cellular compartments of the brain, when the data amounts to a few measured arterial venous concentration differences. By using a recently developed methodology to perform Bayesian Flux Balance Analysis and a new five compartment model of the astrocyte-glutamatergic neuron cellular complex, we are able to identify the preferred biochemical pathways during shortage of glucose and in the presence of ketone bodies in the arterial blood. The analysis is performed in a minimally biased way, therefore revealing the potential of this methodology for hypothesis testing.

Many-body effects in the mesoscopic x-ray edge problem

International Nuclear Information System (INIS)

Hentschel, Martina; Roeder, Georg; Ullmo, Denis

2007-01-01

Many-body phenomena, a key interest in the investigation of bulk solid state systems, are studied here in the context of the x-ray edge problem for mesoscopic systems. We investigate the many-body effects associated with the sudden perturbation following the x-ray exciton of a core electron into the conduction band. For small systems with dimensions at the nanoscale we find considerable deviations from the well-understood metallic case where Anderson orthogonality catastrophe and the Mahan-Nozieres-DeDominicis response cause characteristic deviations of the photoabsorption cross section from the naive expectation. Whereas the K-edge is typically rounded in metallic systems, we find a slightly peaked K-edge in generic mesoscopic systems with chaotic-coherent electron dynamics. Thus the behavior of the photoabsorption cross section at threshold depends on the system size and is different for the metallic and the mesoscopic case. (author)

Modified Kepler's law, escape speed, and two-body problem in modified Newtonian dynamics-like theories

International Nuclear Information System (INIS)

Zhao Hongsheng; Li Baojiu; Bienayme, Olivier

2010-01-01

We derive a simple analytical expression for the two-body force in a subclass of modified Newtonian dynamics (MOND) theories and make testable predictions in the modification to the two-body orbital period, shape, precession rate, escape speed, etc. We demonstrate the applications of the modified Kepler's law in the timing of satellite orbits around the Milky Way, and checking the feasibility of MOND in the orbit of the large Magellanic cloud, the M31 galaxy, and the merging bullet clusters. MOND appears to be consistent with satellite orbits although with a tight margin. Our results on two-bodies are also generalized to restricted three-body, many-body problems, rings, and shells.

Problems occurred in prospecting and mining of a broken thick large uranium ore body and improvement scheme

International Nuclear Information System (INIS)

Hu Longfei; Fang Yang; Wang Yishun; Wang Long

2014-01-01

In prospecting and mining of a broken thick large uranium ore body, uncertain prospecting and shallow-hole shrinkage mining method resulted in large dilution rate and resource waste problems. Aimed at these problems, improvement schemes of enhancing the strength force of 'drilling prospecting instead of pit prospecting' and employing filling method stoping ore body were applied, and improvement result was analyzed. Experience was accumulated and evidence was provided for late prospecting and stoping work. (authors)

The quantum N-body problem in the mean-field and semiclassical regime.

Science.gov (United States)

Golse, François

2018-04-28

The present work discusses the mean-field limit for the quantum N -body problem in the semiclassical regime. More precisely, we establish a convergence rate for the mean-field limit which is uniform as the ratio of Planck constant to the action of the typical single particle tends to zero. This convergence rate is formulated in terms of a quantum analogue of the quadratic Monge-Kantorovich or Wasserstein distance. This paper is an account of some recent collaboration with C. Mouhot, T. Paul and M. Pulvirenti.This article is part of the themed issue 'Hilbert's sixth problem'. © 2018 The Author(s).

Proceedings of the meeting on few-body problems in high and medium energy physics

International Nuclear Information System (INIS)

Yukawa, T.

1985-12-01

The study meeting on few-body problems in high and medium energy physics was held from October 3 to 5, 1985, at National Laboratory for High Energy Physics. Two meetings were held already concerning few body physics, but most of the participants were theorists. In this meeting, high priority was put on the attendance of experimental physicists. As a bridge between particle and nuclear physics, the few body physics in an intermediate energy region has become important recently. The topics in this meeting were meson spectroscopy, baryonium, kaon physics, muonic fusion, dibaryon, φNN system, quarks and skyrmions, NN correlation, and symmetry test in few-body system. The gists of the papers presented are collected in this book. (Kako, I.)

Algebraic internal wave solitons and the integrable Calogero--Moser--Sutherland N-body problem

International Nuclear Information System (INIS)

Chen, H.H.; Lee, Y.C.; Pereira, N.R.

1979-01-01

The Benjamin--Ono equation that describes nonlinear internal waves in a stratified fluid is solved by a pole expansion method. The dynamics of poles which characterize solitons is shown to be identical to the well-known integrable N-body problem of Calogero, Moser, and Sutherland

[Anxiety and body image among women growing up in families with addiction problem].

Science.gov (United States)

Lelek, Agnieszka; Betkowska-Korpała, Barbara; Jabłoński, Marcin

2011-01-01

The aim of the study was to analyse the correlation between body image and anxiety symptoms as well as psychological discomfort experienced by women growing up in alcoholic families. The group of 61 women (27 years old on average) was surveyed with Body Self Questionnaire and MMPI-2 personality test questionnaires and the results were measured on Scale 7 (Pt). All the participants also attended psychotherapy sessions focused on disorders resulting from growing up in families with alcohol problems. The analysis showed negative correlation (p emotional spheres, as well as functioning cognitive schemes.

Behavioural problems in children who weigh 1000 g or less at birth in four countries.

Science.gov (United States)

Hille, E T; den Ouden, A L; Saigal, S; Wolke, D; Lambert, M; Whitaker, A; Pinto-Martin, J A; Hoult, L; Meyer, R; Feldman, J F; Verloove-Vanhorick, S P; Paneth, N

2001-05-26

The increased survival chances of extremely low-birthweight (ELBW) infants (weighing cultural comparisons are lacking. Our aim was to compare behavioural problems in ELBW children of similar ages from four countries. We prospectively studied 408 ELBW children aged 8-10 years, whose parents completed the child behaviour checklist. The children came from the Netherlands, Germany, Canada, and USA. The checklist provides a total problem score consisting of eight narrow-band scales. Of these, two (aggressive and delinquent behaviour) give a broad-band externalising score, three (anxious, somatic, and withdrawn behaviour) give a broad-band internalising score, and three (social, thought, and attention problems) indicate difficulties fitting neither broad-band dimension. For each cohort we analysed scores in ELBW children and those in normal- birthweight controls (two cohorts) or national normative controls (two cohorts). Across countries, we assessed deviations of the ELBW children from normative or control groups. ELBW children had higher total problem scores than normative or control children, but this increase was only significant in European countries. Narrow-band scores were raised only for the social, thought, and attention difficulty scales, which were 0.5-1.2 SD higher in ELBW children than in others. Except for the increase in internalising scores recorded for one cohort, ELBW children did not differ from normative or control children on internalising or externalising scales. Despite cultural differences, types of behavioural problems seen in ELBW children were very similar in the four countries. This finding suggests that biological mechanisms contribute to behavioural problems of ELBW children.

A cluster expansion for bound three-alpha particles as a three-body problem

International Nuclear Information System (INIS)

Osman, A.

1981-08-01

A three-body model is proposed to study the nuclear bound states. The nucleus is described as a bound state of three clusters. A cluster expansion is introduced for the three cluster bound state problem. The present integral equations are treated by simple approximate solutions, which lead to effective potentials by using the present cluster expansion. The 12 C nucleus is described as a three-alpha particle bound state. The binding energy of 12 C is calculated numerically using the present cluster expansion as bound three-alpha clusters. The present three-body cluster expansion calculations are very near to the exact three-body calculations using separable potentials. The present theoretical calculations are in good agreement with the experimental measurements. (author)

Symmetry and geometry of the N-body problem. Application to the nuclear physics

International Nuclear Information System (INIS)

Chau, H.T.P.

2002-10-01

One of the main goals of classical and quantum physics is to solve the many-body problem. In nuclear theory, several methods have been developed and provide accurate results. In this thesis, we remind how symmetry can be used to obtain analytical solutions of the quantum many-body problem. We emphasize that unitary Lie algebras play a crucial role in quantum mechanics and propose and implement a method to build irreducible representations of this algebra from its highest-weight state. Calculations of bosonic and fermionic spectra are performed with realistic and with random interactions. Studies with rotational invariant two-body random interactions have unveiled high degree of order (a marked statistical preference is found for ground states with angular momentum equal to zero). In the second chapter of this thesis, it is argued that the spectral properties of this kind of interaction depend on the choice of the valence space. In particular, we propose a geometrical method to predict the properties of the ground state in certain cases. We also present numerical results when the geometrical approach can not be applied. In the third chapter, we study the link between quantum chaos and nuclear spectra calculated with realistic interactions. (author)

Highly eccentric hip-hop solutions of the 2 N-body problem

Science.gov (United States)

Barrabés, Esther; Cors, Josep M.; Pinyol, Conxita; Soler, Jaume

2010-02-01

We show the existence of families of hip-hop solutions in the equal-mass 2 N-body problem which are close to highly eccentric planar elliptic homographic motions of 2 N bodies plus small perpendicular non-harmonic oscillations. By introducing a parameter ɛ, the homographic motion and the small amplitude oscillations can be uncoupled into a purely Keplerian homographic motion of fixed period and a vertical oscillation described by a Hill type equation. Small changes in the eccentricity induce large variations in the period of the perpendicular oscillation and give rise, via a Bolzano argument, to resonant periodic solutions of the uncoupled system in a rotating frame. For small ɛ≠0, the topological transversality persists and Brouwer’s fixed point theorem shows the existence of this kind of solutions in the full system.

Nuclear many-body problem with repulsive hard core interactions

Energy Technology Data Exchange (ETDEWEB)

Haddad, L M

1965-07-01

The nuclear many-body problem is considered using the perturbation-theoretic approach of Brueckner and collaborators. This approach is outlined with particular attention paid to the graphical representation of the terms in the perturbation expansion. The problem is transformed to centre-of-mass coordinates in configuration space and difficulties involved in ordinary methods of solution of the resulting equation are discussed. A new technique, the 'reference spectrum method', devised by Bethe, Brandow and Petschek in an attempt to simplify the numerical work in presented. The basic equations are derived in this approximation and considering the repulsive hard core part of the interaction only, the effective mass is calculated at high momentum (using the same energy spectrum for both 'particle' and 'hole' states). The result of 0.87m is in agreement with that of Bethe et al. A more complete treatment using the reference spectrum method in introduced and a self-consistent set of equations is established for the reference spectrum parameters again for the case of hard core repulsions. (author)

CTBC. A program to solve the collinear three-body Coulomb problem. Bound states and scattering below the three-body disintegration threshold

International Nuclear Information System (INIS)

Tolstikhin, Oleg I.; Namba, Chusei

2003-08-01

A program to solve the quantum-mechanical collinear three-body Coulomb problem is described and illustrated by calculations for a number of representative systems and processes. In the internal region, the Schroedinger equation is solved in hyperspherical coordinates using the slow/smooth variable discretization method. In asymptotic regions, the solution is obtained in Jacobi coordinates using the asymptotic package GAILIT from the CPC library. Only bound states and scattering processes below the three-body disintegration threshold are considered here; resonances and fragmentation processes will be discussed in subsequent parts of this series. (author)

Results of Four Studies on Logo Programming, Problem Solving, and Knowledge-Based Instructional Design.

Science.gov (United States)

Swan, Karen; Black, John B.

The results of four research studies conducted with subjects ranging in age and ability from elementary to graduate school students demonstrate that Logo programming environments can be instrumental in the development of five particular problem solving strategies: (1) subgoals formation; (2) forward chaining; (3) systematic trial and error; (4)…

A method for solving a three-body problem with energy-dependent interactions

International Nuclear Information System (INIS)

Safronov, A.N.

1994-01-01

A method is proposed for solving a three-body problem with energy-dependent interactions. This method is based on introducing the dependence of scattering operators and state vectors on an additional external parameter. Effects caused by the energy dependence of the interaction operator are investigated by using the unitary condition for the amplitude of the 2 → 2 and 2 → 3 transitions. It is shown, in particular, that taking this dependence into account leads to a change in the relation between the asymptotic normalization factor of the wave function of the three-body bound state and the vertex constant of virtual dissociation (synthesis) of the system into two fragments. 15 refs

Bridging problems and models in medical ethics: four images of local ethics committees.

Science.gov (United States)

Incorvati, G

In the context of the continuing debate about how ethics committees in Italy should be structured (see Bulletin 160) Professor Incorvati, from the Comitato Nazionale per la Bioetica in Rome, considers four theoretical models of how such committees may be arranged, and why one in particular looks better placed to face the growing ethical problems that are emerging as a result of current developments in medicine.

Body image and body change: predictive factors in an Iranian population.

Science.gov (United States)

Garrusi, Behshid; Garousi, Saeide; Baneshi, Mohammad R

2013-08-01

Body concerns and its health consequences such as eating disorders and harmful body change activities are mentioned in Asian countries. This study evaluates factors contributing to body image/shape changes in an Iranian population. In this cross-sectional study we focused on four main body change activity (diet, exercise, substance use, and surgery) and their risk factors such as demographic variables, Body Mass Index (BMI), Media, Body-Esteem, Perceived Socio-cultural Pressure, Body dissatisfaction and, Self-Esteem. Approximately, 1,200 individuals between 14-55 years old participated in this study. We used a multistage sampling method. In each region, the first household was selected at random. The probability of outcomes was estimated from logistic models. About 54.3% of respondents were females. The mean (SD) of age was 31.06 (10.24) years. Variables such as gender, age, BMI, use of media and socio cultural factors as, body dissatisfaction, body-esteem and pressure by relatives were the main factors that influenced body change methods. In particular we have seen that male are 53% less likely to follow surgical treatments, but 125% were more likely to use substances. Investigation of body concern and its health related problem should be assessed in cultural context. For effectiveness of interventional programs and reducing harmful body image/shape changes activities, socio-cultural background should be noted.

Body image and body change: Predictive factors in an Iranian population

Directory of Open Access Journals (Sweden)

Behshid Garrusi

2013-01-01

Full Text Available Background: Body concerns and its health consequences such as eating disorders and harmful body change activities are mentioned in Asian countries. This study evaluates factors contributing to body image/shape changes in an Iranian population. Methods: In this cross-sectional study we focused on four main body change activity (diet, exercise, substance use, and surgery and their risk factors such as demographic variables, Body Mass Index (BMI, Media, Body-Esteem, Perceived Socio-cultural Pressure, Body dissatisfaction and, Self-Esteem. Approximately, 1,200 individuals between 14-55 years old participated in this study. We used a multistage sampling method. In each region, the first household was selected at random. The probability of outcomes was estimated from logistic models. Results: About 54.3% of respondents were females. The mean (SD of age was 31.06 (10.24 years. Variables such as gender, age, BMI, use of media and socio cultural factors as, body dissatisfaction, body-esteem and pressure by relatives were the main factors that influenced body change methods. In particular we have seen that male are 53% less likely to follow surgical treatments, but 125% were more likely to use substances. Conclusions: Investigation of body concern and its health related problem should be assessed in cultural context. For effectiveness of interventional programs and reducing harmful body image/shape changes activities, socio-cultural background should be noted.

Body Image and Body Change: Predictive Factors in an Iranian Population

Science.gov (United States)

Garrusi, Behshid; Garousi, Saeide; Baneshi, Mohammad R.

2013-01-01

Background: Body concerns and its health consequences such as eating disorders and harmful body change activities are mentioned in Asian countries. This study evaluates factors contributing to body image/shape changes in an Iranian population. Methods: In this cross-sectional study we focused on four main body change activity (diet, exercise, substance use, and surgery) and their risk factors such as demographic variables, Body Mass Index (BMI), Media, Body-Esteem, Perceived Socio-cultural Pressure, Body dissatisfaction and, Self-Esteem. Approximately, 1,200 individuals between 14-55 years old participated in this study. We used a multistage sampling method. In each region, the first household was selected at random. The probability of outcomes was estimated from logistic models. Results: About 54.3% of respondents were females. The mean (SD) of age was 31.06 (10.24) years. Variables such as gender, age, BMI, use of media and socio cultural factors as, body dissatisfaction, body-esteem and pressure by relatives were the main factors that influenced body change methods. In particular we have seen that male are 53% less likely to follow surgical treatments, but 125% were more likely to use substances. Conclusions: Investigation of body concern and its health related problem should be assessed in cultural context. For effectiveness of interventional programs and reducing harmful body image/shape changes activities, socio-cultural background should be noted. PMID:24049621

On the n-body problem on surfaces of revolution

Science.gov (United States)

Stoica, Cristina

2018-05-01

We explore the n-body problem, n ≥ 3, on a surface of revolution with a general interaction depending on the pairwise geodesic distance. Using the geometric methods of classical mechanics we determine a large set of properties. In particular, we show that Saari's conjecture fails on surfaces of revolution admitting a geodesic circle. We define homographic motions and, using the discrete symmetries, prove that when the masses are equal, they form an invariant manifold. On this manifold the dynamics are reducible to a one-degree of freedom system. We also find that for attractive interactions, regular n-gon shaped relative equilibria with trajectories located on geodesic circles typically experience a pitchfork bifurcation. Some applications are included.

Spurious solutions in few-body equations

International Nuclear Information System (INIS)

Adhikari, S.K.; Gloeckle, W.

1979-01-01

After Faddeev and Yakubovskii showed how to write connected few-body equations which are free from discrete spurious solutions various authors have proposed different connected few-body scattering equations. Federbush first pointed out that Weinberg's formulation admits the existence of discrete spurious solutions. In this paper we investigate the possibility and consequence of the existence of spurious solutions in some of the few-body formulations. Contrary to a proof by Hahn, Kouri, and Levin and by Bencze and Tandy the channel coupling array scheme of Kouri, Levin, and Tobocman which is also the starting point of a formulation by Hahn is shown to admit spurious solutions. We can show that the set of six coupled four-body equations proposed independently by Mitra, Gillespie, Sugar, and Panchapakesan, by Rosenberg, by Alessandrini, and by Takahashi and Mishima and the seven coupled four-body equations proposed by Sloan and related by matrix multipliers to basic sets which correspond uniquely to the Schroedinger equation. These multipliers are likely to give spurious solutions to these equations. In all these cases spuriosities are shown to have no hazardous consequence if one is interested in studying the scattering problem

Effects of Four-Month Exercise Program on Correction of Body Posture of Persons with Different Visual Impairment

Directory of Open Access Journals (Sweden)

Damira Vranesic-Hadzimehmedovic

2018-04-01

Full Text Available The aim of this study was to determine the effect of a four-month specific exercise program on correcting the posture of persons with different visual impairment. The sample consisted of 20 elementary students with visual impairment diagnosis, 11 boys and 9 girls aged 9-14 (12±0.6. The classification of the examinees was performed according to the established degree of visual impairment, 10 blind persons and 10 partially sighted persons. The pupils voluntarily participated in the exercise program. The exercise program was structured of two phases: exercise on dryland and exercise in water. A total of 36 exercise units were completed during four months period. Seven tests were used to evaluate the body posture, based on the determination of segmental dimensions and the visual projection of the marked points. The contents of the program were performed with the aim of preventing and correcting the observed irregularities of the body posture. The t-test scores indicated statistically significant differences between two measurements (p<0.05, p<0.01. It can be concluded that elementary movements, performed through dryland and especially water exercises, had a good effect on correcting the body's posture of blind and partially sighted persons.

Tails and bridges in the parabolic restricted three-body problem

Science.gov (United States)

Barrabés, Esther; Cors, Josep M.; Garcia-Taberner, Laura; Ollé, Mercè

2017-12-01

After a close encounter of two galaxies, bridges and tails can be seen between or around them. A bridge would be a spiral arm between a galaxy and its companion, whereas a tail would correspond to a long and curving set of debris escaping from the galaxy. The goal of this paper is to present a mechanism, applying techniques of dynamical systems theory, that explains the formation of tails and bridges between galaxies in a simple model, the so-called parabolic restricted three-body problem, i.e. we study the motion of a particle under the gravitational influence of two primaries describing parabolic orbits. The equilibrium points and the final evolutions in this problem are recalled,and we show that the invariant manifolds of the collinear equilibrium points and the ones of the collision manifold explain the formation of bridges and tails. Massive numerical simulations are carried out and their application to recover previous results are also analysed.

Visualization of Oil Body Distribution in Jatropha curcas L. by Four-Wave Mixing Microscopy

Science.gov (United States)

Ishii, Makiko; Uchiyama, Susumu; Ozeki, Yasuyuki; Kajiyama, Sin'ichiro; Itoh, Kazuyoshi; Fukui, Kiichi

2013-06-01

Jatropha curcas L. (jatropha) is a superior oil crop for biofuel production. To improve the oil yield of jatropha by breeding, the development of effective and reliable tools to evaluate the oil production efficiency is essential. The characteristics of the jatropha kernel, which contains a large amount of oil, are not fully understood yet. Here, we demonstrate the application of four-wave mixing (FWM) microscopy to visualize the distribution of oil bodies in a jatropha kernel without staining. FWM microscopy enables us to visualize the size and morphology of oil bodies and to determine the oil content in the kernel to be 33.2%. The signal obtained from FWM microscopy comprises both of stimulated parametric emission (SPE) and coherent anti-Stokes Raman scattering (CARS) signals. In the present situation, where a very short pump pulse is employed, the SPE signal is believed to dominate the FWM signal.

Universal algorithms and programs for calculating the motion parameters in the two-body problem

Science.gov (United States)

Bakhshiyan, B. T.; Sukhanov, A. A.

1979-01-01

The algorithms and FORTRAN programs for computing positions and velocities, orbital elements and first and second partial derivatives in the two-body problem are presented. The algorithms are applicable for any value of eccentricity and are convenient for computing various navigation parameters.

Time-frequency analysis of the restricted three-body problem: transport and resonance transitions

International Nuclear Information System (INIS)

Vela-Arevalo, Luz V; Marsden, Jerrold E

2004-01-01

A method of time-frequency analysis based on wavelets is applied to the problem of transport between different regions of the solar system, using the model of the circular restricted three-body problem in both the planar and the spatial versions of the problem. The method is based on the extraction of instantaneous frequencies from the wavelet transform of numerical solutions. Time-varying frequencies provide a good diagnostic tool to discern chaotic trajectories from regular ones, and we can identify resonance islands that greatly affect the dynamics. Good accuracy in the calculation of time-varying frequencies allows us to determine resonance trappings of chaotic trajectories and resonance transitions. We show the relation between resonance transitions and transport in different regions of the phase space

Discontinuous Petrov–Galerkin method with optimal test functions for thin-body problems in solid mechanics

KAUST Repository

Niemi, Antti H.; Bramwell, Jamie A.; Demkowicz, Leszek F.

2011-01-01

We study the applicability of the discontinuous Petrov-Galerkin (DPG) variational framework for thin-body problems in structural mechanics. Our numerical approach is based on discontinuous piecewise polynomial finite element spaces for the trial

Studies on muon cycling rates in muon catalyzed D-T fusion system with possible four-body muonic molecules formation

International Nuclear Information System (INIS)

Eskandri, M.R.; Hosini Motlagh, N.; Hataf, A.

2000-01-01

In recent studies, it is shown that the fusion rate for four-body molecules of ppμμ, ddμμ, ptμμ, pdμμ, dtμμ, ttμμ, is considerably larger than that of similar three-body molecules of ppμμ, ddμμ, ptμμ, pdμμ, dtμμ, ttμμ. It is shown that for dtμμ, fusion rate is R f (dt) ≅ 3 * 10 13 - 6 * * 10 13 S -1 which is 40 times higher than fusion rate of dtμμ molecule. In this paper we have looked for the effect of these molecules formation in muon catalyzed D-T fusion. The required data for all possible branches do not exist, so the main dtμμ branch are considered here. By choosing a variable value for dtμμ molecule formation rate and comparing obtained cycling rates with existing experimental values, the order of this parameter is evaluated to be ≅ 10 9 S -1 . Using obtained data in different conditions of D-T muon cycling rate calculations have shown that considering of four-body molecule formations in existing muon injection intensities do not make considerable change in three-body muonic molecule cycling rate

Three-body problem in the ground-state representation

International Nuclear Information System (INIS)

Gonzalez, A.

1993-01-01

The ground-state probability density of a three-body system is used to construct a classical potential U whose minimum coincides exactly with the ground-state energy. The spectrum of excited states may approximately be obtained by imposing quasiclassical quantization conditions over the classical motion in U. We show nontrivial one-dimensional models in which either this quantization condition is exact or considerably improves the usual semiclassical quantization. For three-dimensional problems, the small-oscillation frequencies in states with total angular momentum L = 0 are computed. These frequencies could represent an improvement over the frequencies of triatomic molecules computed with the use of ordinary quasiclassics for the motion of the nuclei in the molecular term. By providing a semiclassical description of the first excited quantum states, the sketched approach rises some interesting questions such as, for example, the relevance (once again) of classical chaos to quantum mechanics

Application of Symplectic Algebraic Dynamics Algorithm to Circular Restricted Three-Body Problem

International Nuclear Information System (INIS)

Wei-Tao, Lu; Hua, Zhang; Shun-Jin, Wang

2008-01-01

Symplectic algebraic dynamics algorithm (SADA) for ordinary differential equations is applied to solve numerically the circular restricted three-body problem (CR3BP) in dynamical astronomy for both stable motion and chaotic motion. The result is compared with those of Runge–Kutta algorithm and symplectic algorithm under the fourth order, which shows that SADA has higher accuracy than the others in the long-term calculations of the CR3BP. (general)

Quasi-four-body treatment of charge transfer in the collision of protons with atomic helium: I. Thomas related mechanisms

Science.gov (United States)

Safarzade, Zohre; Fathi, Reza; Shojaei Akbarabadi, Farideh; Bolorizadeh, Mohammad A.

2018-04-01

The scattering of a completely bare ion by atoms larger than hydrogen is at least a four-body interaction, and the charge transfer channel involves a two-step process. Amongst the two-step interactions of the high-velocity single charge transfer in an anion-atom collision, there is one whose amplitude demonstrates a peak in the angular distribution of the cross sections. This peak, the so-called Thomas peak, was predicted by Thomas in a two-step interaction, classically, which could also be described through three-body quantum mechanical models. This work discusses a four-body quantum treatment of the charge transfer in ion-atom collisions, where two-step interactions illustrating a Thomas peak are emphasized. In addition, the Pauli exclusion principle is taken into account for the initial and final states as well as the operators. It will be demonstrated that there is a momentum condition for each two-step interaction to occur in a single charge transfer channel, where new classical interactions lead to the Thomas mechanism.

Dynamical Behavior of a Rigid Body with One Fixed Point (Gyroscope. Basic Concepts and Results. Open Problems: a Review

Directory of Open Access Journals (Sweden)

Svetoslav Ganchev Nikolov

2015-07-01

Full Text Available The study of the dynamic behavior of a rigid body with one fixed point (gyroscope has a long history. A number of famous mathematicians and mechanical engineers have devoted enormous time and effort to clarify the role of dynamic effects on its movement (behavior – stable, periodic, quasi-periodic or chaotic. The main objectives of this review are: 1 to outline the characteristic features of the theory of dynamical systems and 2 to reveal the specific properties of the motion of a rigid body with one fixed point (gyroscope.This article consists of six sections. The first section addresses the main concepts of the theory of dynamical systems. Section two presents the main theoretical results (obtained so far concerning the dynamic behavior of a solid with one fixed point (gyroscope. Section three examines the problem of gyroscopic stabilization. Section four deals with the non-linear (chaotic dynamics of the gyroscope. Section five is a brief analysis of the gyroscope applications in engineering. The final section provides conclusions and generalizations on why the theory of dynamical systems should be used in the study of the movement of gyroscopic systems.

Scalable algorithms for contact problems

CERN Document Server

Dostál, Zdeněk; Sadowská, Marie; Vondrák, Vít

2016-01-01

This book presents a comprehensive and self-contained treatment of the authors’ newly developed scalable algorithms for the solutions of multibody contact problems of linear elasticity. The brand new feature of these algorithms is theoretically supported numerical scalability and parallel scalability demonstrated on problems discretized by billions of degrees of freedom. The theory supports solving multibody frictionless contact problems, contact problems with possibly orthotropic Tresca’s friction, and transient contact problems. It covers BEM discretization, jumping coefficients, floating bodies, mortar non-penetration conditions, etc. The exposition is divided into four parts, the first of which reviews appropriate facets of linear algebra, optimization, and analysis. The most important algorithms and optimality results are presented in the third part of the volume. The presentation is complete, including continuous formulation, discretization, decomposition, optimality results, and numerical experimen...

Exact Analytical Solutions in Three-Body Problems and Model of Neutrino Generator

Directory of Open Access Journals (Sweden)

Takibayev N.Zh.

2010-04-01

Full Text Available Exact analytic solutions are obtained in three-body problem for the scattering of light particle on the subsystem of two fixed centers in the case when pair potentials have a separable form. Solutions show an appearance of new resonance states and dependence of resonance energy and width on distance between two fixed centers. The approach of exact analytical solutions is expanded to the cases when two-body scattering amplitudes have the Breit-Wigner’s form and employed for description of neutron resonance scattering on subsystem of two heavy nuclei fixed in nodes of crystalline lattice. It is shown that some resonance states have widths close to zero at the certain values of distance between two heavy scatterer centers, this gives the possibility of transitions between states. One of these transitions between three-body resonance states could be connected with process of electron capture by proton with formation of neutron and emission of neutrino. This exoenergic process leading to the cooling of star without nuclear reactions is discussed.

In-Medium Similarity Renormalization Group Approach to the Nuclear Many-Body Problem

Science.gov (United States)

Hergert, Heiko; Bogner, Scott K.; Lietz, Justin G.; Morris, Titus D.; Novario, Samuel J.; Parzuchowski, Nathan M.; Yuan, Fei

We present a pedagogical discussion of Similarity Renormalization Group (SRG) methods, in particular the In-Medium SRG (IMSRG) approach for solving the nuclear many-body problem. These methods use continuous unitary transformations to evolve the nuclear Hamiltonian to a desired shape. The IMSRG, in particular, is used to decouple the ground state from all excitations and solve the many-body Schrödinger equation. We discuss the IMSRG formalism as well as its numerical implementation, and use the method to study the pairing model and infinite neutron matter. We compare our results with those of Coupled cluster theory (Chap. 8), Configuration-Interaction Monte Carlo (Chap. 9), and the Self-Consistent Green's Function approach discussed in Chap. 11 The chapter concludes with an expanded overview of current research directions, and a look ahead at upcoming developments.

Slender body treatment of some specialized problems associated with elliptic-cross-section missile configurations

Science.gov (United States)

Barger, R. L.

1977-01-01

Slender body methods were applied to some specialized problems associated with missile configurations with elliptic cross sections. Expressions are derived for computing the velocity distribution on the nose section when the ellipse eccentricity is varying longitudinally on the missile. The cross flow velocity on a triform fin section is also studied.

Global regularization method for planar restricted three-body problem

Directory of Open Access Journals (Sweden)

Sharaf M.A.

2015-01-01

Full Text Available In this paper, global regularization method for planar restricted three-body problem is purposed by using the transformation z = x+iy = ν cos n(u+iv, where i = √−1, 0 < ν ≤ 1 and n is a positive integer. The method is developed analytically and computationally. For the analytical developments, analytical solutions in power series of the pseudotime τ are obtained for positions and velocities (u, v, u', v' and (x, y, x˙, y˙ in both regularized and physical planes respectively, the physical time t is also obtained as power series in τ. Moreover, relations between the coefficients of the power series are obtained for two consequent values of n. Also, we developed analytical solutions in power series form for the inverse problem of finding τ in terms of t. As typical examples, three symbolic expressions for the coefficients of the power series were developed in terms of initial values. As to the computational developments, the global regularized equations of motion are developed together with their initial values in forms suitable for digital computations using any differential equations solver. On the other hand, for numerical evolutions of power series, an efficient method depending on the continued fraction theory is provided.

Cognitive Neuroscience and the "Mind-Body problem"

Directory of Open Access Journals (Sweden)

Grega Repovš

2004-08-01

Full Text Available In recent years we have witnessed an upsurge of interest in the study of the human mind and how it relates to the material body, the brain. Cognitive neuroscience is a multidisciplinary science that tries to explain how the mind arises from the structure and workings of the brain. Can we equate the study of mind-body relationship with cognitive neuroscience? Are there aspects of mind-body relationship that are not covered by cognitive neuroscience? Is cognitive neuroscience able to explain human behaviour and experience? These are the questions that are addressed in this "Beginner's Guide to Cognitive neuroscience and it's relation to the Body-Mind question".

An existence proof of a symmetric periodic orbit in the octahedral six-body problem

OpenAIRE

Cavalcanti, Anete Soares

2016-01-01

We present a proof of the existence of a periodic orbit for the Newtonian six-body problem with equal masses. This orbit has three double collisions each period and no multiple collisions. Our proof is based on the minimization of the Lagrangian action functional on a well chosen class of symmetric loops.

Dynamic contact problem with adhesion and damage between thermo-electro-elasto-viscoplastic bodies

Science.gov (United States)

Hadj ammar, Tedjani; Saïdi, Abdelkader; Azeb Ahmed, Abdelaziz

2017-05-01

We study of a dynamic contact problem between two thermo-electro-elasto-viscoplastic bodies with damage and adhesion. The contact is frictionless and is modeled with normal compliance condition. We derive variational formulation for the model and prove an existence and uniqueness result of the weak solution. The proof is based on arguments of evolutionary variational inequalities, parabolic inequalities, differential equations, and fixed point theorem.

9Be+120Sn scattering at near-barrier energies within a four-body model

Science.gov (United States)

Arazi, A.; Casal, J.; Rodríguez-Gallardo, M.; Arias, J. M.; Lichtenthäler Filho, R.; Abriola, D.; Capurro, O. A.; Cardona, M. A.; Carnelli, P. F. F.; de Barbará, E.; Fernández Niello, J.; Figueira, J. M.; Fimiani, L.; Hojman, D.; Martí, G. V.; Martínez Heimman, D.; Pacheco, A. J.

2018-04-01

Cross sections for elastic and inelastic scattering of the weakly bound 9Be nucleus on a 120Sn target have been measured at seven bombarding energies around and above the Coulomb barrier. The elastic angular distributions are analyzed with a four-body continuum-discretized coupled-channels (CDCC) calculation, which considers 9Be as a three-body projectile (α +α +n ). An optical model analysis using the São Paulo potential is also shown for comparison. The CDCC analysis shows that the coupling to the continuum part of the spectrum is important for the agreement with experimental data even at energies around the Coulomb barrier, suggesting that breakup is an important process at low energies. At the highest incident energies, two inelastic peaks are observed at 1.19(5) and 2.41(5) MeV. Coupled-channels (CC) calculations using a rotational model confirm that the first inelastic peak corresponds to the excitation of the 21+ state in 120Sn, while the second one likely corresponds to the excitation of the 31- state.

A frictional contact problem with damage and adhesion for an electro elastic-viscoplastic body

Directory of Open Access Journals (Sweden)

Adel Aissaoui

2014-01-01

Full Text Available We consider a quasistatic frictional contact problem for an electro elastic-viscopalastic body with damage and adhestion. The contact is modelled with normal compliance. The adhesion of the contact surfaces is taken into account and modelled by a surface variable. We derive variational formulation for the model which is in the form of a system involving the displacement field, the electric potential field, the damage field and the adhesion field. We prove the existence of a unique weak solution to the problem. The proof is based on arguments of time-dependent variational inequalities, parabolic inequalities, differential equations and fixed point.

Prognosis and continuity of child mental health problems from preschool to primary school: results of a four-year longitudinal study.

Science.gov (United States)

Beyer, Thomas; Postert, Christian; Müller, Jörg M; Furniss, Tilman

2012-08-01

In a four-year longitudinal study, changes in and continuity of behavioral and emotional problems were examined in 814 subjects from kindergarten to primary school. Mental health problems were assessed by means of the Child Behavior Checklist (CBCL). The distribution of the CBCL broadband groups revealed a high level of continuity of internalizing symptoms over the four-year period and a shift from externalizing symptoms at baseline towards a combination of internalizing and externalizing symptoms at follow-up. The presence of mental health problems at follow-up was correlated with gender (higher amongst boys), pre-existing mental health problems at baseline, and separation or divorce of the parents, but not with single-family status or the age and educational level of the mother. The increasing number of children with a combination of internalizing and externalizing symptoms demonstrates the increasing complexity of child mental health problems in the developmental span from preschool age to school age.

GENERAL: Application of Symplectic Algebraic Dynamics Algorithm to Circular Restricted Three-Body Problem

Science.gov (United States)

Lu, Wei-Tao; Zhang, Hua; Wang, Shun-Jin

2008-07-01

Symplectic algebraic dynamics algorithm (SADA) for ordinary differential equations is applied to solve numerically the circular restricted three-body problem (CR3BP) in dynamical astronomy for both stable motion and chaotic motion. The result is compared with those of Runge-Kutta algorithm and symplectic algorithm under the fourth order, which shows that SADA has higher accuracy than the others in the long-term calculations of the CR3BP.

High-Order Analytic Expansion of Disturbing Function for Doubly Averaged Circular Restricted Three-Body Problem

Directory of Open Access Journals (Sweden)

Takashi Ito

2016-01-01

Full Text Available Terms in the analytic expansion of the doubly averaged disturbing function for the circular restricted three-body problem using the Legendre polynomial are explicitly calculated up to the fourteenth order of semimajor axis ratio (α between perturbed and perturbing bodies in the inner case (α1. The expansion outcome is compared with results from numerical quadrature on an equipotential surface. Comparison with direct numerical integration of equations of motion is also presented. Overall, the high-order analytic expansion of the doubly averaged disturbing function yields a result that agrees well with the numerical quadrature and with the numerical integration. Local extremums of the doubly averaged disturbing function are quantitatively reproduced by the high-order analytic expansion even when α is large. Although the analytic expansion is not applicable in some circumstances such as when orbits of perturbed and perturbing bodies cross or when strong mean motion resonance is at work, our expansion result will be useful for analytically understanding the long-term dynamical behavior of perturbed bodies in circular restricted three-body systems.

Robe's Restricted Problem of 2 + 2 Bodies with a Roche Ellipsoid - Triaxial System

Science.gov (United States)

Aggarwal, Rajiv; Kaur, Bhavneet; Yadav, Sushil

2018-03-01

This paper investigates the motion of two infinitesimal masses on the location and stability of the equilibrium points in Robe's restricted problem of 2 + 2 bodies with the bigger primary a Roche ellipsoid and the smaller a triaxial body. We suppose the bigger primary of mass m 1 to be filled with a homogeneous incompressible fluid of density ρ 1. The third and the fourth bodies (of mass m 3 and m 4 respectively) are small solid spheres of density ρ 3 and ρ 4 respectively inside the ellipsoid, with the assumption that the mass and the radius of the third and the fourth body are infinitesimal. We assume that m 2 is describing a circle around m 1. The masses m 3 and m 4 mutually attract each other, do not influence the motion of m 1 and m 2 but are influenced by them. We have taken into consideration all the three components of the pressure field in deriving the expression for the buoyancy force viz (i) due to the own gravitational field of the fluid (ii) that originating in the attraction of m 2 (iii) that arising from the centrifugal force. In this paper, equilibrium solutions of m 3 and m 4 and their linear stability are analyzed.

An algorithm for analytical solution of basic problems featuring elastostatic bodies with cavities and surface flaws

Science.gov (United States)

Penkov, V. B.; Levina, L. V.; Novikova, O. S.; Shulmin, A. S.

2018-03-01

Herein we propose a methodology for structuring a full parametric analytical solution to problems featuring elastostatic media based on state-of-the-art computing facilities that support computerized algebra. The methodology includes: direct and reverse application of P-Theorem; methods of accounting for physical properties of media; accounting for variable geometrical parameters of bodies, parameters of boundary states, independent parameters of volume forces, and remote stress factors. An efficient tool to address the task is the sustainable method of boundary states originally designed for the purposes of computerized algebra and based on the isomorphism of Hilbertian spaces of internal states and boundary states of bodies. We performed full parametric solutions of basic problems featuring a ball with a nonconcentric spherical cavity, a ball with a near-surface flaw, and an unlimited medium with two spherical cavities.

How the carotid body works: Different strategies and preparations to solve different problems

OpenAIRE

ZAPATA, PATRICIO; LARRAÍN, CAROLINA

2005-01-01

This is a review of the different experimental approaches developed to solve the problems in our progress towards a comprehensive understanding of how arterial chemoreceptors operate. An analysis is performed of the bases, advantages and limits of the following preparations: studies of ventilatory reflexes originated from carotid bodies (CBs) in the entire animal; recordings of CB chemosensory discharges in situ; CB preparations perfused in situ; CB explants in oculo; CB explants in ovo; CB p...

Evaluation of a four month rehabilitation program for stroke patients with balance problems and binocular visual dysfunction

DEFF Research Database (Denmark)

Schow, Trine; Harris, Paul; Teasdale, Thomas William

2016-01-01

Trine Schow, Paul Harris, Thomas William Teasdale, Morten Arendt Rasmussen. Evaluation of a four month rehabilitation program for stroke patients with balance problems and binocular visual dysfunction. NeuroRehabilitation. 2016 Apr 6;38(4):331-41. doi: 10.3233/NRE-161324....

Stability and periodicity in the Sitnikov three-body problem when primaries are oblate spheroids

Science.gov (United States)

Rahman, M. A.; Garain, D. N.; Hassan, M. R.

2015-05-01

This paper deals with the effect of oblateness of the primaries of equal masses on the series solutions of the Sitnikov problem of three bodies. Effects of oblateness have also been shown on the stability of libration points and Poincare surface of section. Here series solutions have been developed with the help of iteration process of Green's function and by the Lindstedt-Poincare method. Following Murray and Dermott (Solar System Dynamics, Cambridge University Press, Cambridge, 1999) we have checked the stability of the equilibrium points in the Sitnikov problem. Periodicity and quasi-periodicity have been examined by drawing the Poincare surfaces of section using the mathematical software.

New trends in few-body systems a 30th anniversary collection

CERN Document Server

2017-01-01

Few-Body Systems refer to a multidisciplinary subject of research in different sectors of physics in which the number of degrees of freedom governing the dynamics is sufficiently low to allow a description with controlled approximations. Examples can be found in atomic, nuclear and subnuclear physics as well as in some aspects of condensed matter. This issue, celebrating the 30th Anniversary of the Journal, contains two review articles, one in exotic hadrons and one in antikaon-nucleon systems, as well as a selection of original articles on experimental and theoretical physics in which modern problems in few-body systems are discussed. Specific arguments, presented by world expert leaders, are very extensive and include the three and four-nucleon system, short-range correlations, universal behavior in few-boson systems, perspectives on the origin of hadron masses, scattering problems and studies using electromagnetic probes. This issue gives an overview of actual problems in Few-Body Systems.

A four-tier problem-solving scaffold to teach pain management in dental school.

Science.gov (United States)

Ivanoff, Chris S; Hottel, Timothy L

2013-06-01

Pain constitutes a major reason patients pursue dental treatment. This article presents a novel curriculum to provide dental students comprehensive training in the management of pain. The curriculum's four-tier scaffold combines traditional and problem-based learning to improve students' diagnostic, pharmacotherapeutic, and assessment skills to optimize decision making when treating pain. Tier 1 provides underpinning knowledge of pain mechanisms with traditional and contextualized instruction by integrating clinical correlations and studying worked cases that stimulate clinical thinking. Tier 2 develops critical decision making skills through self-directed learning and actively solving problem-based cases. Tier 3 exposes students to management approaches taken in allied health fields and cultivates interdisciplinary communication skills. Tier 4 provides a "knowledge and experience synthesis" by rotating students through community pain clinics to practice their assessment skills. This combined teaching approach aims to increase critical thinking and problem-solving skills to assist dental graduates in better management of pain throughout their careers. Dental curricula that have moved to comprehensive care/private practice models are well-suited for this educational approach. The goal of this article is to encourage dental schools to integrate pain management into their curricula, to develop pain management curriculum resources for dental students, and to provide leadership for change in pain management education.

Changes in Body Mass Index and Stoma Related Problems in the Elderly

Science.gov (United States)

Skeps, Raymond; McMullen, Carmit K.; Wendel, Christopher S.; Bulkley, Joanna; Grant, Marcia; Mohler, Jane; Hornbrook, Mark C.; Krouse, Robert S.; Herrinton, Lisa J.

2012-01-01

Objectives Weight gain can cause retraction of an intestinal stoma, possibly resulting in difficulty with wafer and pouch fit, daily care challenges, and discomfort. This cross-sectional study examined the association between body mass index (BMI) and ostomy-related problems among long-term (>5 years post-diagnosis) colorectal cancer (CRC) survivors. Materials and Methods CRC survivors from three Kaiser Permanente Regions completed a mailed survey. The response rate for those with an ostomy was 53% (283/529). Questions included stoma-related problems and time to conduct daily ostomy care. Poisson regression evaluated associations between report of problems and change in BMI. Our analysis sample included 235 survivors. Results Sample was 76% ≥65 years of age. Since their surgeries, BMI remained stable in 44% (ST), decreased in 20% (DE), and increased in 35% (IN) of survivors. Compared to ST, male IN (RR 2.15 [1.09–4.25]) and female DE (RR 5.06 [1.26–25.0]) were more likely to spend more than 30 minutes per day on stoma care. IN (vs. ST) were more likely to report interference with clothing (RR 1.51 [1.06–2.17]) and other stoma-related problems (RR 2.32 [1.30–4.14]). Survivors who were obese at time of survey were more likely to report interference with clothing (RR 1.88 [1.38–2.56]) and other stoma-related problems (RR 1.68 [1.07–2.65]). Conclusion A change in BMI is associated with ostomy-related problems among long-term CRC survivors. Equipment and care practices may need to be adapted for changes in abdominal shape. Health care providers should caution that a significant increase or decrease in BMI may cause ostomy-related problems. PMID:24071496

Towards a more efficient environmental policy. A socio-economic analysis of four persistent environmental problems

International Nuclear Information System (INIS)

2000-11-01

For the benefit of the National Environmental Policy Plan that will be published in 2001, the Netherlands Bureau for Economic Policy Analysis analysed four persistent environmental problems. These problems are the environmental effects of the manure surplus in the agricultural sector; the climate problem; the acidification by traffic and the air traffic noise around the airport Schiphol. This study not only looks ahead, but also looks back on 30 years of environmental policy. From a welfare economic perspective an analysis is made of the efficiency and effectiveness of that policy. Several questions are answered,e.g.: how could the manure problem of such a small sector as the livestock breeding persist for so many years?; how effective were the agreements with the industry and other sectors on energy efficiency improvement?; what made the acidification policy directed on traffic so successful?; why is the noise production of air traffic still a problem whereas the number of seriously bothered houses is decreased? The answers on these questions provide information which can be useful for the formulation of the future environmental policy. This information refers to the conditions for formulating adequate policy goals, the relation between those goals and policy instruments and the differences between direct versus indirect steering. This report also gives some points of interest for tackling complex international environmental problems. refs

The black-body radiation inversion problem, its instability and a new universal function set method

International Nuclear Information System (INIS)

Ye, JiPing; Ji, FengMin; Wen, Tao; Dai, Xian-Xi; Dai, Ji-Xin; Evenson, William E.

2006-01-01

The black-body radiation inversion (BRI) problem is ill-posed and requires special techniques to achieve stable solutions. In this Letter, the universal function set method (UFS), is developed in BRI. An improved unique existence theorem is proposed. Asymptotic behavior control (ABC) is introduced. A numerical example shows that practical calculations are possible with UFS

Method of resonating groups in the Faddeev-Hahn equation formalism for three-body nuclear problem

CERN Document Server

Nasirov, M Z

2002-01-01

The Faddeev-Hahn equation formalism for three-body nuclear problem is considered. For solution of the equations the method of resonant groups have applied. The calculations of tritium binding energy and doublet nd-scattering length have been carried out. The results obtained shows that Faddeev-Hahn equation formalism is very simple and effective. (author)

Shape space figure-8 solution of three body problem with two equal masses

Science.gov (United States)

Yu, Guowei

2017-06-01

In a preprint by Montgomery (https://people.ucsc.edu/~rmont/Nbdy.html), the author attempted to prove the existence of a shape space figure-8 solution of the Newtonian three body problem with two equal masses (it looks like a figure 8 in the shape space, which is different from the famous figure-8 solution with three equal masses (Chenciner and Montgomery 2000 Ann. Math. 152 881-901)). Unfortunately there is an error in the proof and the problem is still open. Consider the α-homogeneous Newton-type potential, 1/rα, using action minimization method, we prove the existence of this solution, for α \\in (1, 2) ; for α=1 (the Newtonian potential), an extra condition is required, which unfortunately seems hard to verify at this moment.

Pseudo-Newtonian planar circular restricted 3-body problem

International Nuclear Information System (INIS)

Dubeibe, F.L.; Lora-Clavijo, F.D.; González, Guillermo A.

2017-01-01

We study the dynamics of the planar circular restricted three-body problem in the context of a pseudo-Newtonian approximation. By using the Fodor–Hoenselaers–Perjés procedure, we perform an expansion in the mass potential of a static massive spherical source up to the first non-Newtonian term, giving place to a gravitational potential that includes first-order general relativistic effects. With this result, we model a system composed by two pseudo-Newtonian primaries describing circular orbits around their common center of mass, and a test particle orbiting the system in the equatorial plane. The dynamics of the new system of equations is studied in terms of the Poincaré section method and the Lyapunov exponents, where the introduction of a new parameter ϵ, allows us to observe the transition from the Newtonian to the pseudo-Newtonian regime. We show that when the Jacobian constant is fixed, a chaotic orbit in the Newtonian regime can be either chaotic or regular in the pseudo-Newtonian approach. As a general result, we find that most of the pseudo-Newtonian configurations are less stable than their Newtonian equivalent.

Pseudo-Newtonian planar circular restricted 3-body problem

Energy Technology Data Exchange (ETDEWEB)

Dubeibe, F.L., E-mail: fldubeibem@unal.edu.co [Facultad de Ciencias Humanas y de la Educación, Universidad de los Llanos, Villavicencio (Colombia); Grupo de Investigación en Relatividad y Gravitación, Escuela de Física, Universidad Industrial de Santander, A.A. 678, Bucaramanga (Colombia); Lora-Clavijo, F.D., E-mail: fadulora@uis.edu.co [Grupo de Investigación en Relatividad y Gravitación, Escuela de Física, Universidad Industrial de Santander, A.A. 678, Bucaramanga (Colombia); González, Guillermo A., E-mail: guillermo.gonzalez@saber.uis.edu.co [Grupo de Investigación en Relatividad y Gravitación, Escuela de Física, Universidad Industrial de Santander, A.A. 678, Bucaramanga (Colombia)

2017-02-12

We study the dynamics of the planar circular restricted three-body problem in the context of a pseudo-Newtonian approximation. By using the Fodor–Hoenselaers–Perjés procedure, we perform an expansion in the mass potential of a static massive spherical source up to the first non-Newtonian term, giving place to a gravitational potential that includes first-order general relativistic effects. With this result, we model a system composed by two pseudo-Newtonian primaries describing circular orbits around their common center of mass, and a test particle orbiting the system in the equatorial plane. The dynamics of the new system of equations is studied in terms of the Poincaré section method and the Lyapunov exponents, where the introduction of a new parameter ϵ, allows us to observe the transition from the Newtonian to the pseudo-Newtonian regime. We show that when the Jacobian constant is fixed, a chaotic orbit in the Newtonian regime can be either chaotic or regular in the pseudo-Newtonian approach. As a general result, we find that most of the pseudo-Newtonian configurations are less stable than their Newtonian equivalent.

Inchworm movement of two rings switching onto a thread by biased Brownian diffusion represent a three-body problem.

Science.gov (United States)

Benson, Christopher R; Maffeo, Christopher; Fatila, Elisabeth M; Liu, Yun; Sheetz, Edward G; Aksimentiev, Aleksei; Singharoy, Abhishek; Flood, Amar H

2018-05-07

The coordinated motion of many individual components underpins the operation of all machines. However, despite generations of experience in engineering, understanding the motion of three or more coupled components remains a challenge, known since the time of Newton as the "three-body problem." Here, we describe, quantify, and simulate a molecular three-body problem of threading two molecular rings onto a linear molecular thread. Specifically, we use voltage-triggered reduction of a tetrazine-based thread to capture two cyanostar macrocycles and form a [3]pseudorotaxane product. As a consequence of the noncovalent coupling between the cyanostar rings, we find the threading occurs by an unexpected and rare inchworm-like motion where one ring follows the other. The mechanism was derived from controls, analysis of cyclic voltammetry (CV) traces, and Brownian dynamics simulations. CVs from two noncovalently interacting rings match that of two covalently linked rings designed to thread via the inchworm pathway, and they deviate considerably from the CV of a macrocycle designed to thread via a stepwise pathway. Time-dependent electrochemistry provides estimates of rate constants for threading. Experimentally derived parameters (energy wells, barriers, diffusion coefficients) helped determine likely pathways of motion with rate-kinetics and Brownian dynamics simulations. Simulations verified intercomponent coupling could be separated into ring-thread interactions for kinetics, and ring-ring interactions for thermodynamics to reduce the three-body problem to a two-body one. Our findings provide a basis for high-throughput design of molecular machinery with multiple components undergoing coupled motion.

Whole-body counter surveys of Miharu-town school children for four consecutive years after the Fukushima NPP accident

Science.gov (United States)

Hayano, Ryugo S.; Tsubokura, Masaharu; Miyazaki, Makoto; Satou, Hideo; Sato, Katsumi; Masaki, Shin; Sakuma, Yu

Comprehensive whole-body counter surveys of Miharu town school children have been conducted for four consecutive years, in 2011-2014. This represents the only long-term sampling-bias-free study of its type conducted after the Fukushima Dai-ichi accident. For the first time in 2014, a new device called the Babyscan, which has a low $^{134/137}$Cs MDA of $< 50$ Bq/body, was used to screen the children shorter than 130 cm. No child in this group was found to have detectable level of radiocesium. Using the MDAs, upper limits of daily intake of radiocesium were estimated for each child. For those screened with the Babyscan, the upper intake limits were found to be <1 Bq/day for $^{137}$Cs. Analysis of a questionnaire filled out by the children's parents regarding their food and water consumption shows that the majority of Miharu children regularly consume local and/or home-grown rice and vegetables. This however does not increase the body burden.

Schwinger variational principle in the nuclear two-body problem and multichannel theory

International Nuclear Information System (INIS)

Zubarev, A.L.; Podkopaev, A.P.

1978-01-01

The aim of the investigation is to study the Schwinger variational principle in the nuclear two-body problem and the multichannel theory. An approach is proposed to problems of the potential scattering based on the substitution of the exact potential operator V by the finite rank operator Vsup((n)) with which the dynamic equations are solved exactly. The functionals obtained for observed values coincide with corresponding expressions derived by the Schwinger variational principle with the set of test functions. The determination of the Schwinger variational principle is given. The method is given for finding amplitude of the double-particle scattering with the potential Vsup((n)). The corresponding amplitudes are constructed within the framework of the multichannel potential model. Interpolation formula for determining amplitude, which describes with high accuracy a process of elastic scattering for any energies, is obtained. On the basis of the above method high-energy amplitude may be obtained within the range of small and large scattering angles

Explaining the Mind: Problems, Problems

OpenAIRE

Harnad, Stevan

2001-01-01

The mind/body problem is the feeling/function problem: How and why do feeling systems feel? The problem is not just "hard" but insoluble (unless one is ready to resort to telekinetic dualism). Fortunately, the "easy" problems of cognitive science (such as the how and why of categorization and language) are not insoluble. Five books (by Damasio, Edelman/Tononi...

Evaluation of a four month rehabilitation program for stroke patients with balance problems and binocular visual dysfunction.

Science.gov (United States)

Schow, Trine; Harris, Paul; Teasdale, Thomas William; Rasmussen, Morten Arendt

2016-04-06

Balance problems and binocular visual dysfunction (BVD) are common problems after stroke, however evidence of an effective rehabilitation method are limited. To evaluate the effect of a four-month rehabilitation program for individuals with balance problems and BVD after a stroke. About 40 sessions of 1.5 hours duration over four months with visual therapy and balance rehabilitation, was provided to all 29 participants, aged 18-67 years, in groups of 7-8 individuals. Several measures for BVD, balance, gait, Health Related Quality Of Life (HRQoL) and functional recovery were used at baseline, at the end of training and at a six-month follow up (FU). We found significant improvements in stereopsis, vergence, saccadic movements, burden of binocular visual symptoms, balance and gait speed, fatigue, HRQoL and functional recovery. Moreover, 60% of the participants were in employment at the six-month FU, compared to only 23% before training. All improvements were sustained at the six-month FU. Although a control group is lacking, the evidence suggests that the positive improvement is a result of the combined visual and balance training. The combination of balance and visual training appears to facilitate changes at a multimodal level affecting several functions important in daily life.

21st International Conference on Few-Body Problems in Physics

CERN Document Server

2015-01-01

The 21st International Conference on Few-Body Problems in Physics (FB21) will take place at the Crowne Plaza Chicago Metro Downtown Hotel in the West Loop area of Chicago, Illinois, USA, from May 18th to 22nd, 2015. The first conference of this series took place in London in 1959 and subsequent meetings were held in Brela (1967), Birmingham (1969), Budapest (1971), Los Angeles (1972), Laval (1974), Delhi (1976), Graz (1978), Eugene (1980), Karlsruhe (1983), Sendai (1986), Vancouver (1989), Adelaide (1992), Williamsburg (1994), Groningen (1997), Taipei (2000), Durham (2003),Santos (2006),Bonn (2009),and Fukuoka (2012) see also "History". FB21 will be conducted with the principles passed by the General Assembly in 2008. In particular, no bona fide scientist will be excluded from participation on the grounds of national origin, nationality, or political considerations unrelated to science.

Illustrating chaos: a schematic discretization of the general three-body problem in Newtonian gravity

Science.gov (United States)

Leigh, Nathan W. C.; Wegsman, Shalma

2018-05-01

We present a formalism for constructing schematic diagrams to depict chaotic three-body interactions in Newtonian gravity. This is done by decomposing each interaction into a series of discrete transformations in energy- and angular momentum-space. Each time a transformation is applied, the system changes state as the particles re-distribute their energy and angular momenta. These diagrams have the virtue of containing all of the quantitative information needed to fully characterize most bound or unbound interactions through time and space, including the total duration of the interaction, the initial and final stable states in addition to every intervening temporary meta-stable state. As shown via an illustrative example for the bound case, prolonged excursions of one of the particles, which by far dominates the computational cost of the simulations, are reduced to a single discrete transformation in energy- and angular momentum-space, thereby potentially mitigating any computational expense. We further generalize our formalism to sequences of (unbound) three-body interactions, as occur in dense stellar environments during binary hardening. Finally, we provide a method for dynamically evolving entire populations of binaries via three-body scattering interactions, using a purely analytic formalism. In principle, the techniques presented here are adaptable to other three-body problems that conserve energy and angular momentum.

Stability at Potential Maxima: The L-4 and L-5 Points of the Restricted Three-Body Problem.

Science.gov (United States)

Greenberg, Richard; Davis, Donald R.

1978-01-01

Describes a dynamical system which is stable at potential maxima. The maxima, called L-4 and L-5, are stable locations of the restricted three-body problem. Energy loss from the system will tend to drive it away from stability. (GA)

A Longitudinal Study on Substance Use and Related Problems in Women in Opioid Maintenance Treatment from Pregnancy to Four Years after Giving Birth

Directory of Open Access Journals (Sweden)

Ingunn O. Lund

2014-01-01

Full Text Available Background Women in opioid maintenance treatment (OMT have a past characterized by drug abuse, which is a challenging start for parenthood. Studies of mothers in OMT are typically limited to pregnancy and early infancy. Knowledge about how they cope with substance use and related problems in the years following birth is therefore important. The aims of the study were to examine changes in mothers’ substance use, psychological problems, and other challenges; from one to four years after their children were born, and describe kindergarten attendance and prevalence and type of child protective services involvement when the children were four years old. Method A four-year prospective cohort study of mothers in OMT. The European severity index was used to map substance use and related problems during the third trimester of pregnancy, one and four years after birth. Results At the four-year follow-up, use of illegal substances remained low (4% and use of legal substances (39% was similar to the one-year follow-up. The proportion of women with psychological problems was significantly higher than at one-year follow-up (69 vs. 39%, P = .009. At age four, most children (89% attended kindergarten, and the child protective services were following 73% of the families, mostly with voluntary measures. Conclusion Mothers in OMT cope well with substance use over time, given access to sufficient support. The findings imply that a preventive governmental strategy with close support of mother and child, have a positive impact contributing to making OMT and motherhood more compatible.

Approach method of the solutions of algebraic models of the N body problem

International Nuclear Information System (INIS)

Dufour, M.

1986-09-01

We have studied a class of algebraic eigenvalue problems that generate tridiagonal matrices. The Lipkin Hamiltonian was chosen as representative. Three methods have been implemented, whose extension to more general many body problems seems possible i) Degenerate Linked Cluster Theory (LCT), which disregards special symmetries of the interaction and defines a hierarchy of approximation based on model spaces at fixed number of particle-hole excitation of the unperturbed Hamiltonian. The method works for small perturbations but does not yield a complete description. ii) A new linearization method that replaces the matrix to be diagonalized by local (tangent) approximations by harmonic matrices. This method generalizes LCT and is a posteriori reminiscent of semi-classical ones. However of is simpler, more precise and yields a complete description of spectra. iii) A global way to characterize spectra based on Gershgorine-Hadamard disks [fr

The coriolis attenuation problem in the perturbed i13/2 neutronbands

Directory of Open Access Journals (Sweden)

T. Engeland

1983-01-01

Full Text Available The Coriolis attenuation problem in the particle-rotor model is shown to be related to the BCS approximation. A model including the full recoil effect of one- and two-body terms, and with an exact diagonalization of the pairing force, is applied on four nuclei in the rare earth region known to have strongly Coriolis-perturbed i13/2 rotational bands. In all nuclei, the old Coriolis attenuation problem has been removed.

Courses for tutors in problem-based learning. Current challenges at four Swedish universities

Directory of Open Access Journals (Sweden)

Helen Susan Setterud

2015-06-01

Full Text Available The key role of the tutor in problem-based learning (PBL is to help students become selfregulated learners. Tutors need training to acquire the necessary facilitating skills for this task. The aim of this article is to describe and discuss how PBL tutor training is currently arranged at four universities in Sweden: Linköping University, Lund Medical Faculty, Uppsala Medical School and Örebro School of Medicine. Moreover, we seek to analyse how the content and format of the tutor training courses correspond to the desired skills and competencies for PBL tutors described in the literature. We draw especially on work coming out of three pioneering universities for PBL: McMaster University, Canada; Maastricht University, The Netherlands; and Linköping University, Sweden. One aim has been to construct a framework for analysis that uses categories specifying the knowledge base, capabilities and skills to support students’ learning processes which characterise the full-fledged PBL tutor. For this framework, we have used the following categories: Knowledge of PBL and pedagogical theories, Personal traits, Student-centeredness, Ability to handle group processes, and Subject knowledge. We collected descriptions of the course design and content from the four universities, and assessed to what extent these categories were represented within the courses. Our results show that all categories inform the course content at all four universities, though the design varies between courses. In summary, we show that the four PBL tutor training courses are all designed to enable participants to experience PBL first-hand both as members of a tutorial group and as tutors. They all also include a theoretical base and offer opportunities for discussion and reflection with peers; however, there are some differences in design between the courses. According to participants, all four courses provide good preparation for the tutor role. Yet, we see a need for the

Whole-body counter surveys of Miharu-town school children for four consecutive years after the Fukushima NPP accident

International Nuclear Information System (INIS)

Hayano, Ryugo S.; Tsubokura, Masaharu; Miyazaki, Makoto; Satou, Hideo; Sato, Katsumi; Masaki, Shin; Sakuma, Yu

2015-01-01

Comprehensive whole-body counter surveys of Miharu-town school children have been conducted for four consecutive years, in 2011-2014. This represents the only long-term sampling-bias-free study of its type conducted after the Fukushima Dai-ichi accident. For the first time in 2014, a new device called the Babyscan, which has a low "1"3"4"/"1"3"7Cs MDA of <50 Bq/body, was used to screen the children shorter than 130 cm. No child in this group was found to have detectable level of radiocesium. Using the MDAs, upper limits of daily intake of radiocesium were estimated for each child. For those screened with the Babyscan, the upper intake limits were found to be ≲1 Bq/day for "1"3"7Cs. Analysis of a questionnaire filled out by the children's parents regarding their food and water consumption shows that the majority of Miharu children regularly consume local and/or home-grown rice and vegetables. This however does not increase the body burden. (author)

Symmetry and geometry of the N-body problem. Application to the nuclear physics; Symetrie et geometrie du probleme a N-corps. Application a la physique nucleaire

Energy Technology Data Exchange (ETDEWEB)

Chau, H.T.P

2002-10-01

One of the main goals of classical and quantum physics is to solve the many-body problem. In nuclear theory, several methods have been developed and provide accurate results. In this thesis, we remind how symmetry can be used to obtain analytical solutions of the quantum many-body problem. We emphasize that unitary Lie algebras play a crucial role in quantum mechanics and propose and implement a method to build irreducible representations of this algebra from its highest-weight state. Calculations of bosonic and fermionic spectra are performed with realistic and with random interactions. Studies with rotational invariant two-body random interactions have unveiled high degree of order (a marked statistical preference is found for ground states with angular momentum equal to zero). In the second chapter of this thesis, it is argued that the spectral properties of this kind of interaction depend on the choice of the valence space. In particular, we propose a geometrical method to predict the properties of the ground state in certain cases. We also present numerical results when the geometrical approach can not be applied. In the third chapter, we study the link between quantum chaos and nuclear spectra calculated with realistic interactions. (author)

The effects of four arthropod diets on the body and organ weights of the leopard frog, Rana pipiens, during vitellogenesis.

Science.gov (United States)

Lehman, G C

1978-12-01

Wild-caught adult Rana pipiens females were captured in midsummer and fed diets of crickets, flies sowbugs or wax moth larvae during a three-month period of active vitellogenesis. The cricket diet supported the most extensive body weight gain during this time and promoted a prolonged period of weight increase in an additional long-term study. Synchronous growth of the oocytes occurred in all four groups, but the ovaries and oviducts of cricket-fed animals were significantly larger than those of frogs on the other three diets. The significantly higher liver weights of frogs fed wax moth larvae may have reflected an augmentation of hepatic energy stores. Fat body weights were also highest in this group of animals. Frogs fed crickets and wax moth larvae possessed larger fat bodies than did the midsummer control animals killed immediately after their arrival in the laboratory. In contrast, frogs fed flies and sowbugs had smaller fat bodies than did the initial controls, suggesting that animals on these diets had utilized fat body lipid during vitellogenesis. Gastrocnemius and final body weights were lowest in frogs fed wax moth larvae. These findings may have reflected the nutritional content of the diet or the reduction in appetite frequently noted in these animals during observations of feeding behavior.

Four-particle scattering with three-particle interactions

International Nuclear Information System (INIS)

Adhikari, S.K.

1979-01-01

The four-particle scattering formalism proposed independently by Alessandrini, by Mitra et al., by Rosenberg, and by Takahashi and Mishima is extended to include a possible three-particle interaction. The kernel of the new equations we get contain both two- and three-body connected parts and gets four-body connected after one iteration. On the other hand, the kernel of the original equations in the absence of three-particle interactions does not have a two-body connected part. We also write scattering equations for the transition operators connecting the two-body fragmentation channels. They are generalization of the Sloan equations in the presence of three-particle interactions. We indicate how to include approximately the effect of a weak three-particle interaction in a practical four-particle scattering calculation

Body Fat Measurements in Singaporean Adults Using Four Methods

Directory of Open Access Journals (Sweden)

Xinyan Bi

2018-03-01

Full Text Available Few studies have been conducted to measure body composition in Asian populations. In this study, we determined the percent body fat (PBF by using dual-energy X-ray absorptiometry (DEXA, air-displacement plethysmography (ADP or BOD POD, bioelectrical impedance analysis (BIA and skinfold (SKF in 445 healthy Singaporean adults. We observed that the BOD POD, BIA and SKF estimates of PBF were highly correlated with that from DEXA (as a reference method among Singaporean adults. However, they all underestimated PBF (differences of 3.9% for BOD POD, 5.6% for BIA and 12.5% for SKF. Our results filled a gap in the literature by testing the relationships between DEXA and BOD POD, BIA and SKF in a large sample with a wide range of body mass index (BMI from 16.1 to 37.5 kg/m2 and age from 21 to 69.2 years. The differences of PBF measured by different methods were dependent on age, gender and ethnicity. No significant difference was observed between DEXA and BOD POD in men aged > 40 or in BMI tertile 3. However, the mean difference between DEXA and BOD POD was significant in women. Different measuring methods of estimating PBF therefore must be cautiously interpreted.

Spurious solutions in few-body equations. II. Numerical investigations

International Nuclear Information System (INIS)

Adhikari, S.K.

1979-01-01

A recent analytic study of spurious solutions in few-body equations by Adhikari and Gloeckle is here complemented by numerical investigations. As proposed by Adhikari and Gloeckle we study numerically the spurious solutions in the three-body Weinberg type equations and draw some general conclusions about the existence of spurious solutions in three-body equations with the Weinberg kernel and in other few-body formulations. In particular we conclude that for most of the potentials we encounter in problems of nuclear physics the three-body Weinberg type equation will not have a spurious solution which may interfere with the bound state or scattering calculation. Hence, if proven convenient, the three-body Weinberg type equation can be used in practical calculations. The same conclusion is true for the three-body channel coupling array scheme of Kouri, Levin, and Tobocman. In the case of the set of six coupled four-body equations proposed by Rosenberg et al. and the set of the Bencze-Redish-Sloan equations a careful study of the possible spurious solutions is needed before using these equations in practical calculations

Health behaviours, body weight and self-esteem among grade five students in Canada.

Science.gov (United States)

Wu, Xiuyun; Kirk, Sara F L; Ohinmaa, Arto; Veugelers, Paul

2016-01-01

This study sought to identify the principal components of self-esteem and the health behavioural determinants of these components among grade five students. We analysed data from a population-based survey among 4918 grade five students, who are primarily 10 and 11 years of age, and their parents in the Canadian province of Nova Scotia. The survey comprised the Harvard Youth and Adolescent Questionnaire, parental reporting of students' physical activity (PA) and time spent watching television or using computer/video games. Students heights and weights were objectively measured. We applied principal component analysis (PCA) to derive the components of self-esteem, and multilevel, multivariable logistic regression to quantify associations of diet quality, PA, sedentary behaviour and body weight with these components of self-esteem. PCA identified four components for self-esteem: self-perception, externalizing problems, internalizing problems, social-perception. Influences of health behaviours and body weight on self-esteem varied across the components. Better diet quality was associated with higher self-perception and fewer externalizing problems. Less PA and more use of computer/video games were related to lower self-perception and social-perception. Excessive TV watching was associated with more internalizing problems. Students classified as obese were more likely to report low self- and social-perception, and to experience fewer externalizing problems relative to students classified as normal weight. This study demonstrates independent influences of diet quality, physical activity, sedentary behaviour and body weight on four aspects of self-esteem among children. These findings suggest that school programs and health promotion strategies that target health behaviours may benefit self-esteem in childhood, and mental health and quality of life later in life.

Two novel classes of solvable many-body problems of goldfish type with constraints

Energy Technology Data Exchange (ETDEWEB)

Calogero, F [Dipartimento di Fisica, Universita di Roma ' La Sapienza' , 00185 Rome (Italy); Gomez-Ullate, D [Departamento de Fisica Teorica II, Universidad Complutense, 28040 Madrid (Spain)

2007-05-18

Two novel classes of many-body models with nonlinear interactions 'of goldfish type' are introduced. They are solvable provided the initial data satisfy a single constraint (in one case; in the other, two constraints), i.e., for such initial data the solution of their initial-value problem can be achieved via algebraic operations, such as finding the eigenvalues of given matrices or equivalently the zeros of known polynomials. Entirely isochronous versions of some of these models are also exhibited, i.e., versions of these models whose nonsingular solutions are all completely periodic with the same period.

Explicit thin-lens solution for an arbitrary four by four uncoupled beam transfer matrix

Energy Technology Data Exchange (ETDEWEB)

Balandin, V. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Orlov, S. [Moscow State Univ. (Russian Federation). Faculty of Computational Mathematics and Cybernetics

2011-10-15

In the design of beam transport lines one often meets the problem of constructing a quadrupole lens system that will produce desired transfer matrices in both the horizontal and vertical planes. Nowadays this problem is typically approached with the help of computer routines, but searching for the numerical solution one has to remember that it is not proven yet that an arbitrary four by four uncoupled beam transfer matrix can be represented by using a finite number of drifts and quadrupoles (representation problem) and the answer to this questions is not known not only for more or less realistic quadrupole field models but also for the both most commonly used approximations of quadrupole focusing, namely thick and thin quadrupole lenses. In this paper we make a step forward in resolving the representation problem and, by giving an explicit solution, we prove that an arbitrary four by four uncoupled beam transfer matrix actually can be obtained as a product of a finite number of thin-lenses and drifts. (orig.)

A simple coordinate space approach to three-body problems ...

Indian Academy of Sciences (India)

We show how to treat the dynamics of an asymmetric three-body system consisting of one heavy and two identical light particles in a simple coordinate space variational approach. The method is constructive and gives an efficient way of resolving a three-body system to an effective two-body system. It is illustrated by ...

Quasi-four-body treatment of charge transfer in the collision of protons with atomic helium: II. Second-order non-Thomas mechanisms and the cross sections

Science.gov (United States)

Safarzade, Zohre; Akbarabadi, Farideh Shojaei; Fathi, Reza; Brunger, Michael J.; Bolorizadeh, Mohammad A.

2018-05-01

A fully quantum mechanical four-body treatment of charge transfer collisions between energetic protons and atomic helium is developed here. The Pauli exclusion principle is applied to both the wave function of the initial and final states as well as the operators involved in the interaction. Prior to the collision, the helium atom is assumed as a two-body system composed of the nucleus, He2+, and an electron cloud composed of two electrons. Nonetheless, four particles are assumed in the final state. As the double interactions contribute extensively in single charge transfer collisions, the Faddeev-Lovelace-Watson scattering formalism describes it best physically. The treatment of the charge transfer cross section, under this quasi-four-body treatment within the FWL formalism, showed that other mechanisms leading to an effect similar to the Thomas one occur at the same scattering angle. Here, we study the two-body interactions which are not classically described but which lead to an effect similar to the Thomas mechanism and finally we calculate the total singlet and triplet amplitudes as well as the angular distributions of the charge transfer cross sections. As the incoming projectiles are assumed to be plane waves, the present results are calculated for high energies; specifically a projectile energy of 7.42 MeV was assumed as this is where experimental results are available in the literature for comparison. Finally, when possible we compare the present results with the other available theoretical data.

Bullying and victimisation are common in four-year-old children and are associated with somatic symptoms and conduct and peer problems.

Science.gov (United States)

Ilola, Anna-Marja; Lempinen, Lotta; Huttunen, Jukka; Ristkari, Terja; Sourander, Andre

2016-05-01

There are few population-based studies on bullying behaviour among preschool children. The aims of the study were to investigate the prevalence of bullying behaviour among four-year-old children, as reported by their parents, the prevalence of types of bullying behaviour and the associations between bullying behaviour and psychosocial factors. This study was based on a population-based study sample of 931 children who attended their check-up at a child health clinic at four years of age. Parents completed the questionnaire about their child's bullying behaviour and risk factors during the check-up. Bullying behaviour, especially being both a bully and a victim, was a common phenomenon among four-year-old children. Being a bully or both a bully and victim were most strongly associated with conduct problems, while being a victim was associated with somatic symptoms and peer problems. Bullying behaviour was frequently found in preschool children and associated with a wide range of other problems, which indicate that routine checking of bullying behaviour should be included in child health clinic check-ups. Bullying prevention programmes are usually targeted at school-aged children, but this study highlights the importance of focusing already on preschool children. ©2016 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Exact many-body dynamics with stochastic one-body density matrix evolution

International Nuclear Information System (INIS)

Lacroix, D.

2004-05-01

In this article, we discuss some properties of the exact treatment of the many-body problem with stochastic Schroedinger equation (SSE). Starting from the SSE theory, an equivalent reformulation is proposed in terms of quantum jumps in the density matrix space. The technical details of the derivation a stochastic version of the Liouville von Neumann equation are given. It is shown that the exact Many-Body problem could be replaced by an ensemble of one-body density evolution, where each density matrix evolves according to its own mean-field augmented by a one-body noise. (author)

Body mass index effects sperm quality: a retrospective study in Northern China

Directory of Open Access Journals (Sweden)

En-Yin Wang

2017-01-01

Full Text Available Excess weight and obesity have become a serious problem in adult men of reproductive age throughout the world. The purpose of this retrospective study was to assess the relationships between body mass index and sperm quality in subfertile couples in a Chinese Han population. Sperm analyses were performed and demographic data collected from 2384 male partners in subfertile couples who visited a reproductive medical center for treatment and preconception counseling. The subjects were classified into four groups according to their body mass index: underweight, normal, overweight, and obese. Of these subjects, 918 (38.3% had a body mass index of >25.0 kg m−0 2 . No significant differences were found between the four groups with respect to age, occupation, level of education, smoking status, alcohol use, duration of sexual abstinence, or the collection time of year for sperm. The results clearly indicated lower sperm quality (total sperm count, sperm concentration, motile sperm, relative amounts of type A motility, and progressive motility sperm [A + B] in overweight and obese participants than in those with normal body mass index. Normal sperm morphology and sperm volume showed no clear difference between the four groups. This study indicates that body mass index has a negative effect on sperm quality in men of subfertile couples in a Northern Chinese population. Further study should be performed to investigate the relationship between body mass index and sperm quality in a larger population.

Three-body interactions in many-body effective field theory

International Nuclear Information System (INIS)

Furnstahl, R.J.

2004-01-01

This contribution is an advertisement for applying effective field theory (EFT) to many-body problems, including nuclei and cold atomic gases. Examples involving three-body interactions are used to illustrate how EFT's quantify and systematically eliminate model dependence, and how they make many-body calculations simpler and more powerful

Stochastic many-body problems in ecology, evolution, neuroscience, and systems biology

Science.gov (United States)

Butler, Thomas C.

Using the tools of many-body theory, I analyze problems in four different areas of biology dominated by strong fluctuations: The evolutionary history of the genetic code, spatiotemporal pattern formation in ecology, spatiotemporal pattern formation in neuroscience and the robustness of a model circadian rhythm circuit in systems biology. In the first two research chapters, I demonstrate that the genetic code is extremely optimal (in the sense that it manages the effects of point mutations or mistranslations efficiently), more than an order of magnitude beyond what was previously thought. I further show that the structure of the genetic code implies that early proteins were probably only loosely defined. Both the nature of early proteins and the extreme optimality of the genetic code are interpreted in light of recent theory [1] as evidence that the evolution of the genetic code was driven by evolutionary dynamics that were dominated by horizontal gene transfer. I then explore the optimality of a proposed precursor to the genetic code. The results show that the precursor code has only limited optimality, which is interpreted as evidence that the precursor emerged prior to translation, or else never existed. In the next part of the dissertation, I introduce a many-body formalism for reaction-diffusion systems described at the mesoscopic scale with master equations. I first apply this formalism to spatially-extended predator-prey ecosystems, resulting in the prediction that many-body correlations and fluctuations drive population cycles in time, called quasicycles. Most of these results were previously known, but were derived using the system size expansion [2, 3]. I next apply the analytical techniques developed in the study of quasi-cycles to a simple model of Turing patterns in a predator-prey ecosystem. This analysis shows that fluctuations drive the formation of a new kind of spatiotemporal pattern formation that I name "quasi-patterns." These quasi

A problem-solving approach to effective insulin injection for patients at either end of the body mass index.

Science.gov (United States)

Juip, Micki; Fitzner, Karen

2012-06-01

People with diabetes require skills and knowledge to adhere to medication regimens and self-manage this complex disease. Effective self-management is contingent upon effective problem solving and decision making. Gaps existed regarding useful approaches to problem solving by individuals with very low and very high body mass index (BMI) who self-administer insulin injections. This article addresses those gaps by presenting findings from a patient survey, a symposium on the topic of problem solving, and recent interviews with diabetes educators to facilitate problem-solving approaches for people with diabetes with high and low BMI who inject insulin and/or other medications. In practice, problem solving involves problem identification, definition, and specification; goal and barrier identification are a prelude to generating a set of potential strategies for problem resolution and applying these strategies to implement a solution. Teaching techniques, such as site rotation and ensuring that people with diabetes use the appropriate equipment, increase confidence with medication adherence. Medication taking is more effective when people with diabetes are equipped with the knowledge, skills, and problem-solving behaviors to effectively self-manage their injections.

[Psychiatric co-morbidity, body image problems and psychotherapeutic interventions for burn survivors: a review].

Science.gov (United States)

Jasper, Stefanie; Rennekampff, Hans-Oliver; de Zwaan, Martina

2013-11-01

Due to progress in burn treatment, more patients even with severe burn injuries survive. Despite this positive development, however, there are still negative somatic and mental consequences. These include the life-long care of scars and pain. In addition, posttraumatic-stress disorder and depression are common consequences. Also distress due to disfigurement and body image problems have to be considered, since this is likely to result in social withdrawal, low self-esteem, and reduction of quality of life. Overall, the impact of mental strain on burn victims is quite high. Therefore, psychotherapeutic treatment approaches should be integrated into the care of patients with burns. This might be helpful for both coping and compliance with long-term treatment. This paper provides a review of the mental co-morbidity of burn victims and of psychotherapeutic treatment approaches focusing on changes in body image and the respective social consequences. © Georg Thieme Verlag KG Stuttgart · New York.

Problems of organization of interaction of administrative bodies and the forces engaged in liquidation of after-effects of radiation accident

International Nuclear Information System (INIS)

Popov, A.P.; Perevezentsev, A.M.

1995-01-01

The paper defines the main problems arising in connection with organization of interaction of the administrative bodies and the forces involved in liquidation of after-effects of radiation accident. It is demonstrated that in order to increase the efficiency of interaction of the administrative bodies of various levels it is necessary to make it automatic. The paper revealed the meaning of the levels of relationship between various automatic systems. 4 refs

Matlab/simMechanics based control of four-bar passive lower-body mechanism for rehabilitation

Directory of Open Access Journals (Sweden)

Ashish Singla

2016-09-01

Full Text Available In recent times, use of wearable devices is becoming popular for providing precise ways of rehabilitation. The focus of this paper is to propose a passive lower body mechanism using a four-bar linkage, which can be actuated via the hip joint to move the other two joints at knee and ankle as well. Simulations are performed here by considering an average male human (height six feet by modelling the gait cycle in CAD software and executing the control strategy in the SimMechanics, which provides a convenient way to study without use of detailed computational mathematics. The study of the controller aspects of the passive mechanism is presented with both PD and PID controllers with auto- and manual-tuned gains. Significant reduction in actuator torques is observed with the manually-tuned PID controller over automatically-tuned PID controller with marginal degradation in the overshoot and settling time.

Analysis of 2H(rvec d,p)3H reaction by the four-body Faddeev-Yakubovsky equations

International Nuclear Information System (INIS)

Uzu, E.; Oryu, S.; Tanifuji, M.

1995-01-01

Very low energy 2 H(rvec d,p) 3 H reactions are investigated by using the four-body Fadeev-Yakubovsky integral equations. The adopted potential is the Ernst-Shakin-Thaler's separable expansion of the Paris potential or the PEST potential. The [3+1] and the [2+2] sub-amplitudes are given by the Hilbert-Schmidt rank-2, rank-3 and rank-4 separable expansion. The calculated total cross section, differential cross section, and tensor analyzing powers at 30keV-90keV are in very good agreement with the experimental data. copyright 1995 American Institute of Physics

Full Two-Body Problem Mass Parameter Observability Explored Through Doubly Synchronous Systems

Science.gov (United States)

Davis, Alex Benjamin; Scheeres, Daniel

2018-04-01

The full two-body problem (F2BP) is often used to model binary asteroid systems, representing the bodies as two finite mass distributions whose dynamics are influenced by their mutual gravity potential. The emergent behavior of the F2BP is highly coupled translational and rotational mutual motion of the mass distributions. For these systems the doubly synchronous equilibrium occurs when both bodies are tidally-locked and in a circular co-orbit. Stable oscillations about this equilibrium can be shown, for the nonplanar system, to be combinations of seven fundamental frequencies of the system and the mutual orbit rate. The fundamental frequencies arise as the linear periods of center manifolds identified about the equilibrium which are heavily influenced by each body’s mass parameters. We leverage these eight dynamical constraints to investigate the observability of binary asteroid mass parameters via dynamical observations. This is accomplished by proving the nonsingularity of the relationship between the frequencies and mass parameters for doubly synchronous systems. Thus we can invert the relationship to show that given observations of the frequencies, we can solve for the mass parameters of a target system. In so doing we are able to predict the estimation covariance of the mass parameters based on observation quality and define necessary observation accuracies for desired mass parameter certainties. We apply these tools to 617 Patroclus, a doubly synchronous Trojan binary and flyby target of the LUCY mission, as well as the Pluto and Charon system in order to predict mutual behaviors of these doubly synchronous systems and to provide observational requirements for these systems’ mass parameters

Deliberate ingestion of foreign bodies by institutionalised psychiatric hospital patients and prison inmates.

LENUS (Irish Health Repository)

O'Sullivan, S T

2012-02-03

Deliberate and recurrent foreign body ingestion is a common problem among institutionalised patients. We review our experience with 36 cases of deliberate foreign body ingestion by prisoners or psychiatric patients, thirty of whom were institutionalised at the time of ingestion. Symptoms were frequently severe in the prison inmate group but, in contrast, psychiatric patients presented with few, if any, symptoms. A majority of objects pass spontaneously or remain in situ without complication. Twenty-four patients were discharged following initial evaluation and without specific treatment. Eight of these were reviewed electively and discharged within one week. Twelve patients were admitted for observation, seven of whom were discharged within 48 hrs. Upper gastrointestinal endoscopy was performed in four patients and an intragastric foreign body identified in two cases. Laparotomy was performed in two cases for unresolving mechanical intestinal obstruction. Management should be conservative when possible, with surgery indicated only for complications.

Body fat measurement among Singaporean Chinese, Malays and Indians: a comparative study using a four-compartment model and different two-compartment models

NARCIS (Netherlands)

Deurenberg-Yap, M.; Schmidt, G.; Staveren, van W.A.; Hautvast, J.G.A.J.; Deurenberg, P.

2001-01-01

This cross-sectional study compared body fat percentage (BF€obtained from a four-compartment (4C) model with BF␏rom hydrometry (using 2H2O), dual-energy X-ray absorptiometry (DXA) and densitometry among the three main ethnic groups (Chinese, Malays and Indians) in Singapore, and determined the

On the Coplanar Integrable Case of the Twice-Averaged Hill Problem with Central Body Oblateness

Science.gov (United States)

Vashkov'yak, M. A.

2018-01-01

The twice-averaged Hill problem with the oblateness of the central planet is considered in the case where its equatorial plane coincides with the plane of its orbital motion relative to the perturbing body. A qualitative study of this so-called coplanar integrable case was begun by Y. Kozai in 1963 and continued by M.L. Lidov and M.V. Yarskaya in 1974. However, no rigorous analytical solution of the problem can be obtained due to the complexity of the integrals. In this paper we obtain some quantitative evolution characteristics and propose an approximate constructive-analytical solution of the evolution system in the form of explicit time dependences of satellite orbit elements. The methodical accuracy has been estimated for several orbits of artificial lunar satellites by comparison with the numerical solution of the evolution system.

Central configurations of the collinear three-body problem and singular surfaces in the mass space

Energy Technology Data Exchange (ETDEWEB)

Xie, Zhifu, E-mail: zxie@vsu.edu [Department of Mathematics and Computer Science, Virginia State University, Petersburg, VA 23806 (United States)

2011-09-12

This Letter is to provide a new approach to study the phenomena of degeneracy of the number of the collinear central configurations under geometric equivalence. A direct and simple explicit parametric expression of the singular surface H{sub 3} is constructed in the mass space (m{sub 1},m{sub 2},m{sub 3}) element of (R{sup +}){sup 3}. The construction of H{sub 3} is from an inverse respective, that is, by specifying positions for the bodies and then determining the masses that are possible to yield a central configuration. It reveals the relationship between the phenomena of degeneracy and the inverse problem of central configurations. We prove that the number of central configurations is decreased to 3!/2-1=2, m{sub 1}, m{sub 2}, and m{sub 3} are mutually distinct if m element of H{sub 3}. Moreover, we know not only the number of central configurations but also what the nonequivalent central configurations are. -- Highlights: → Provide a new method to study the degeneracy of number of CC. → Results advanced the understanding of number of central configurations. → Singular mass surface H{sub 3} is given by a direct and simple parametric expression. → The proof only requires some basic knowledge of linear algebra. → The method can be applied to some other collinear n-body problem.

Existence and Linear Stability of Equilibrium Points in the Robe’s Restricted Three-Body Problem with Oblateness

Directory of Open Access Journals (Sweden)

Jagadish Singh

2012-01-01

Full Text Available This paper investigates the positions and linear stability of an infinitesimal body around the equilibrium points in the framework of the Robe’s circular restricted three-body problem, with assumptions that the hydrostatic equilibrium figure of the first primary is an oblate spheroid and the second primary is an oblate body as well. It is found that equilibrium point exists near the centre of the first primary. Further, there can be one more equilibrium point on the line joining the centers of both primaries. Points on the circle within the first primary are also equilibrium points under certain conditions and the existence of two out-of-plane points is also observed. The linear stability of this configuration is examined and it is found that points near the center of the first primary are conditionally stable, while the circular and out of plane equilibrium points are unstable.

Discontinuous Petrov–Galerkin method with optimal test functions for thin-body problems in solid mechanics

KAUST Repository

Niemi, Antti H.

2011-02-01

We study the applicability of the discontinuous Petrov-Galerkin (DPG) variational framework for thin-body problems in structural mechanics. Our numerical approach is based on discontinuous piecewise polynomial finite element spaces for the trial functions and approximate, local computation of the corresponding \\'optimal\\' test functions. In the Timoshenko beam problem, the proposed method is shown to provide the best approximation in an energy-type norm which is equivalent to the L2-norm for all the unknowns, uniformly with respect to the thickness parameter. The same formulation remains valid also for the asymptotic Euler-Bernoulli solution. As another one-dimensional model problem we consider the modelling of the so called basic edge effect in shell deformations. In particular, we derive a special norm for the test space which leads to a robust method in terms of the shell thickness. Finally, we demonstrate how a posteriori error estimator arising directly from the discontinuous variational framework can be utilized to generate an optimal hp-mesh for resolving the boundary layer. © 2010 Elsevier B.V.

Bifurcation and instability problems in vortex wakes

DEFF Research Database (Denmark)

Aref, Hassan; Brøns, Morten; Stremler, Mark A.

2007-01-01

A number of instability and bifurcation problems related to the dynamics of vortex wake flows are addressed using various analytical tools and approaches. We discuss the bifurcations of the streamline pattern behind a bluff body as a vortex wake is produced, a theory of the universal Strouhal......-Reynolds number relation for vortex wakes, the bifurcation diagram for "exotic" wake patterns behind an oscillating cylinder first determined experimentally by Williamson & Roshko, and the bifurcations in topology of the streamlines pattern in point vortex streets. The Hamiltonian dynamics of point vortices...... in a periodic strip is considered. The classical results of von Kármán concerning the structure of the vortex street follow from the two-vortices-in-a-strip problem, while the stability results follow largely from a four-vortices-in-a-strip analysis. The three-vortices-in-a-strip problem is argued...

Few body problems in nuclear and particle physics

International Nuclear Information System (INIS)

Slobodrian, R.J.; Cujec, B.; Ramavataram, K.

1975-01-01

Nucleon-nucleon interactions at all energies, meson-nucleon and meson-deuteron interactions, nuclear bremsstrahlung, on-shell and off-shell interactions, final-state interactions, bound and scattering states, few-body forces, polarization phenomena, short range correlations, quasi-free scattering, composite hadron models, subnucleon structure, multiparticle and coherent production processes, break-up reactions, electrodisintegration, relativistic effects and future resources in nuclear and particle physics are discussed in relation to the state of few-body physics in 1974. (B.F.G.)

On the two-body problem in quantum mechanics

International Nuclear Information System (INIS)

Micu, L.

2008-01-01

Following the representation of a two-body system in classical mechanics, we build up a quantum picture which is free of spurious effects and retains the intrinsic features of the internal bodies. In the coordinate space the system is represented by the real particles, individually bound to a center of forces which in a certain limit coincides with the center of mass and the wave function writes as product of the individual wave functions with correlated arguments. (author)

Effect of four additional physical education lessons on body composition in children aged 8-13 years - a prospective study during two school years

DEFF Research Database (Denmark)

Klakk, Heidi; Chinapaw, Mai; Heidemann, Malene

2013-01-01

Strategies for combating increasing childhood obesity is called for. School settings have been pointed out as potentially effective settings for prevention. The objective of this paper was to evaluate the effect of four additional Physical Education (PE) lessons/week in primary schools on body...

The philosophical "mind-body problem" and its relevance for the relationship between psychiatry and the neurosciences.

Science.gov (United States)

Van Oudenhove, Lukas; Cuypers, Stefaan E

2010-01-01

Parallel to psychiatry, "philosophy of mind" investigates the relationship between mind (mental domain) and body/brain (physical domain). Unlike older forms of philosophy of mind, contemporary analytical philosophy is not exclusively based on introspection and conceptual analysis, but also draws upon the empirical methods and findings of the sciences. This article outlines the conceptual framework of the "mind-body problem" as formulated in contemporary analytical philosophy and argues that this philosophical debate has potentially far-reaching implications for psychiatry as a clinical-scientific discipline, especially for its own autonomy and its relationship to neurology/neuroscience. This point is illustrated by a conceptual analysis of the five principles formulated in Kandel's 1998 article "A New Intellectual Framework for Psychiatry." Kandel's position in the philosophical mind-body debate is ambiguous, ranging from reductive physicalism (psychophysical identity theory) to non-reductive physicalism (in which the mental "supervenes" on the physical) to epiphenomenalist dualism or even emergent dualism. We illustrate how these diverging interpretations result in radically different views on the identity of psychiatry and its relationship with the rapidly expanding domain of neurology/neuroscience.

Solving the Mind-Body Problem through Two Distinct Concepts: Internal-Mental Existence and Internal Mental Reality

OpenAIRE

Ion G. Motofei; David L. Rowland

2015-01-01

In a previous published paper, we initiated in this journal discussion about new perspectives regarding the organization and functioning of the mind, as a premise for addressing the mind-body problem. In this article, we continue focussing discussion on two distinct but interrelated concepts, internal-mental existence/ entity and internal-mental reality. These two psycho-physiological subunits of the mind interact each other in the form of an internal-mental interaction, having no sense if...

On the evolution of galaxy clustering and cosmological N-body simulations

International Nuclear Information System (INIS)

Fall, S.M.

1978-01-01

Some aspects of the problem of simulating the evolution of galaxy clustering by N-body computer experiments are discussed. The results of four 1000-body experiments are presented and interpreted on the basis of simple scaling arguments for the gravitational condensation of bound aggregates. They indicate that the internal dynamics of condensed aggregates are negligible in determining the form of the pair-correlation function xi. On small scales the form of xi is determined by discreteness effects in the initial N-body distribution and is not sensitive to this distribution. The experiments discussed here test the simple scaling arguments effectively for only one value of the cosmological density parameter (Ω = 1) and one form of the initial fluctuation spectrum (n = 0). (author)

Exact self-energy of the many-body problem from conserving approximations

International Nuclear Information System (INIS)

Takada, Y.

1995-01-01

A procedure is proposed to obtain the exact self-energy in the many-body problem. This algorithm is based on the formal analysis to reach the exact theory by repeated applications of an operator F to an arbitrarily chosen input self-energy represented as a functional of the dressed Green's function. The operator F is so defined that the microscopic conservation law for particle number is satisfied. The rigorous self-energy is obtained by the solution of an eigenfunction of F. Particular attention is paid to the relation between the present procedure and the Baym-Kadanoff framework of conserving approximations. By simplifying the procedure in F with use of the generalized Ward identity, we suggest a practical method to implement this algorithm rather easily in actual systems. In order to suggest future directions to improve on this practical method, the recently developed mean-field theory for the Hubbard model in the limit of high spatial dimensions is also discussed in the context of our theory

Compromise solution in the problem of change state control for the material body exposed to the external medium

Science.gov (United States)

Malafeyev, O. A.; Redinskikh, N. D.

2018-05-01

The problem of finding optimal temperature control of the material body state under the unknown in advance parameters of the external medium is formalized and studied in this paper. The problems of this type arise frequently in the real life. An optimal thermal regime is necessary to apply at the soil thawing or freezing, drying the building materials, heating the concrete to obtain the required strength, and so on. Problems of such type one can analyze making use the apparatus and methods of game theory. For describing the influence of external medium on the characteristics of different materials we make use the many-step two person zero-sum game in this paper. The compromise solution is taken as the optimality principle. The numerical example is given.

Correlation between observable of four nucleon system in two-body model

International Nuclear Information System (INIS)

Barlette, V.E.

1988-01-01

The four nucleon system with effective nucleon-trinucleon interaction for s waves in states of spin Y = 0 and isospin Y = 0, is studied. The correlations between four nucleon systemn and scattering wavelength, binding energies and, coulomb energy of four nucleons are investigated by N/D method considering only the excited state. (M.C.K.)

Analysis of 2H(d vector, p)3H reaction at 30-90 keV by four-body Faddeev-Yakubovsky equation

International Nuclear Information System (INIS)

Uzu, Eizo; Oryu, Shinsho; Tanifuji, Makoto.

1993-01-01

Low-energy 2 H(d vector, p) 3 H reactions are investigated by the four-body Faddeev-Yakubovsky equations. Cross sections and tensor analyzing powers are calculated at 30-90 keV energies. The PEST-1 potentials are used for nucleon-nucleon interactions. The [2+2] and [3+1] subamplitudes are treated by the Hilbert-Schmidt expansions. Numerical results give qualitative explanation of experimental data. (author)

Pulsating Different Curves of Zero Velocity around Triangular Equilibrium Points in Elliptical Restricted Three-Body Problem

Directory of Open Access Journals (Sweden)

A. Narayan

2013-01-01

Full Text Available The oblateness and the photogravitational effects of both the primaries on the location and the stability of the triangular equilibrium points in the elliptical restricted three-body problem have been discussed. The stability of the triangular points under the photogravitational and oblateness effects of both the primaries around the binary systems Achird, Lyeten, Alpha Cen-AB, Kruger 60, and Xi-Bootis, has been studied using simulation techniques by drawing different curves of zero velocity.

Intestinal perforation by an ingested foreign body*

Science.gov (United States)

Nicolodi, Gabriel Cleve; Trippia, Cesar Rodrigo; Caboclo, Maria Fernanda F. S.; de Castro, Francisco Gomes; Miller, Wagner Peitl; de Lima, Raphael Rodrigues; Tazima, Leandro; Geraldo, Jamylle

2016-01-01

Objective To identify the computed tomography findings suggestive of intestinal perforation by an ingested foreign body. Materials and Methods This was a retrospective study of four cases of surgically proven intestinal perforation by a foreign body, comparing the computed tomography findings with those described in the literature. Results None of the patients reported having ingested a foreign body, all were over 60 years of age, three of the four patients used a dental prosthesis, and all of the foreign bodies were elongated and sharp. In all four patients, there were findings indicative of acute abdomen. None of the foreign bodies were identified on conventional X-rays. The computed tomography findings suggestive of perforation were thickening of the intestinal walls (in all four cases), increased density of mesenteric fat (in all four cases), identification of the foreign body passing through the intestinal wall (in three cases), and gas in the peritoneal cavity (in one case). Conclusion In cases of foreign body ingestion, intestinal perforation is more common when the foreign body is elongated and sharp. Although patients typically do not report having ingested such foreign bodies, the scenario should be suspected in elderly individuals who use dental prostheses. A computed tomography scan can detect foreign bodies, locate perforations, and guide treatment. The findings that suggest perforation are thickening of the intestinal walls, increased mesenteric fat density, and, less frequently, gas in the peritoneal cavity, often restricted to the point of perforation. PMID:27818542

Intestinal perforation by an ingested foreign body

International Nuclear Information System (INIS)

Nicolodi, Gabriel Cleve; Trippia, Cesar Rodrigo; Caboclo, Maria Fernanda F.S.; Castro, Francisco Gomes de; Miller, Wagner Peitl; Lima, Raphael Rodrigues de; Tazima, Leandro; Geraldo, Jamylle

2016-01-01

Objective: To identify the computed tomography findings suggestive of intestinal perforation by an ingested foreign body. Materials and Methods: This was a retrospective study of four cases of surgically proven intestinal perforation by a foreign body, comparing the computed tomography findings with those described in the literature. Results: None of the patients reported having ingested a foreign body, all were over 60 years of age, three of the four patients used a dental prosthesis, and all of the foreign bodies were elongated and sharp. In all four patients, there were findings indicative of acute abdomen. None of the foreign bodies were identified on conventional X-rays. The computed tomography findings suggestive of perforation were thickening of the intestinal walls (in all four cases), increased density of mesenteric fat (in all four cases), identification of the foreign body passing through the intestinal wall (in three cases), and gas in the peritoneal cavity (in one case). Conclusion: In cases of foreign body ingestion, intestinal perforation is more common when the foreign body is elongated and sharp. Although patients typically do not report having ingested such foreign bodies, the scenario should be suspected in elderly individuals who use dental prostheses. A computed tomography scan can detect foreign bodies, locate perforations, and guide treatment. The findings that suggest perforation are thickening of the intestinal walls, increased mesenteric fat density, and, less frequently, gas in the peritoneal cavity, often restricted to the point of perforation. (author)

Intestinal perforation by an ingested foreign body.

Science.gov (United States)

Nicolodi, Gabriel Cleve; Trippia, Cesar Rodrigo; Caboclo, Maria Fernanda F S; de Castro, Francisco Gomes; Miller, Wagner Peitl; de Lima, Raphael Rodrigues; Tazima, Leandro; Geraldo, Jamylle

2016-01-01

To identify the computed tomography findings suggestive of intestinal perforation by an ingested foreign body. This was a retrospective study of four cases of surgically proven intestinal perforation by a foreign body, comparing the computed tomography findings with those described in the literature. None of the patients reported having ingested a foreign body, all were over 60 years of age, three of the four patients used a dental prosthesis, and all of the foreign bodies were elongated and sharp. In all four patients, there were findings indicative of acute abdomen. None of the foreign bodies were identified on conventional X-rays. The computed tomography findings suggestive of perforation were thickening of the intestinal walls (in all four cases), increased density of mesenteric fat (in all four cases), identification of the foreign body passing through the intestinal wall (in three cases), and gas in the peritoneal cavity (in one case). In cases of foreign body ingestion, intestinal perforation is more common when the foreign body is elongated and sharp. Although patients typically do not report having ingested such foreign bodies, the scenario should be suspected in elderly individuals who use dental prostheses. A computed tomography scan can detect foreign bodies, locate perforations, and guide treatment. The findings that suggest perforation are thickening of the intestinal walls, increased mesenteric fat density, and, less frequently, gas in the peritoneal cavity, often restricted to the point of perforation.

Intestinal perforation by an ingested foreign body

Energy Technology Data Exchange (ETDEWEB)

Nicolodi, Gabriel Cleve; Trippia, Cesar Rodrigo; Caboclo, Maria Fernanda F.S.; Castro, Francisco Gomes de; Miller, Wagner Peitl; Lima, Raphael Rodrigues de; Tazima, Leandro; Geraldo, Jamylle, E-mail: gabrielnicolodi@gmail.com [Hospital Sao Vicente - Funef, Curitiba, PR (Brazil)

2016-09-15

Objective: To identify the computed tomography findings suggestive of intestinal perforation by an ingested foreign body. Materials and Methods: This was a retrospective study of four cases of surgically proven intestinal perforation by a foreign body, comparing the computed tomography findings with those described in the literature. Results: None of the patients reported having ingested a foreign body, all were over 60 years of age, three of the four patients used a dental prosthesis, and all of the foreign bodies were elongated and sharp. In all four patients, there were findings indicative of acute abdomen. None of the foreign bodies were identified on conventional X-rays. The computed tomography findings suggestive of perforation were thickening of the intestinal walls (in all four cases), increased density of mesenteric fat (in all four cases), identification of the foreign body passing through the intestinal wall (in three cases), and gas in the peritoneal cavity (in one case). Conclusion: In cases of foreign body ingestion, intestinal perforation is more common when the foreign body is elongated and sharp. Although patients typically do not report having ingested such foreign bodies, the scenario should be suspected in elderly individuals who use dental prostheses. A computed tomography scan can detect foreign bodies, locate perforations, and guide treatment. The findings that suggest perforation are thickening of the intestinal walls, increased mesenteric fat density, and, less frequently, gas in the peritoneal cavity, often restricted to the point of perforation. (author)

Intestinal perforation by an ingested foreign body

Directory of Open Access Journals (Sweden)

Gabriel Cleve Nicolodi

Full Text Available Abstract Objective: To identify the computed tomography findings suggestive of intestinal perforation by an ingested foreign body. Materials and Methods: This was a retrospective study of four cases of surgically proven intestinal perforation by a foreign body, comparing the computed tomography findings with those described in the literature. Results: None of the patients reported having ingested a foreign body, all were over 60 years of age, three of the four patients used a dental prosthesis, and all of the foreign bodies were elongated and sharp. In all four patients, there were findings indicative of acute abdomen. None of the foreign bodies were identified on conventional X-rays. The computed tomography findings suggestive of perforation were thickening of the intestinal walls (in all four cases, increased density of mesenteric fat (in all four cases, identification of the foreign body passing through the intestinal wall (in three cases, and gas in the peritoneal cavity (in one case. Conclusion: In cases of foreign body ingestion, intestinal perforation is more common when the foreign body is elongated and sharp. Although patients typically do not report having ingested such foreign bodies, the scenario should be suspected in elderly individuals who use dental prostheses. A computed tomography scan can detect foreign bodies, locate perforations, and guide treatment. The findings that suggest perforation are thickening of the intestinal walls, increased mesenteric fat density, and, less frequently, gas in the peritoneal cavity, often restricted to the point of perforation.

Multiple Positive Solutions of a Nonlinear Four-Point Singular Boundary Value Problem with a p-Laplacian Operator on Time Scales

Directory of Open Access Journals (Sweden)

Shihuang Hong

2009-01-01

Full Text Available We present sufficient conditions for the existence of at least twin or triple positive solutions of a nonlinear four-point singular boundary value problem with a p-Laplacian dynamic equation on a time scale. Our results are obtained via some new multiple fixed point theorems.

Magnetic factor in solar-terrestrial relations and its impact on the human body: physical problems and prospects for research

Science.gov (United States)

Breus, T. K.; Binhi, V. N.; Petrukovich, A. A.

2016-05-01

The body of current heliobiological evidence suggests that very weak variable magnetic fields due to solar- and geomagnetic-activities do have a biological effect. Geomagnetic disturbances can cause a nonspecific reaction in the human body - a kind of general adaptation syndrome which occurs due to any external stress factor. Also, specific reactions can develop. One of the reasons discussed for the similarity between biological and heliogeophysical rhythms is that geomagnetic variations have a direct influence on organisms, although exact magnetoreception mechanisms are not yet clear. The paper briefly reviews the current state of empirical and theoretical work on this fundamental multidisciplinary problem.

Few-Body Problems in Experimental Nuclear Astrophysics

DEFF Research Database (Denmark)

Fynbo, H.O.U.

2013-01-01

The 3α-reaction is one of the key reactions in nuclear astrophysics. Since it is a three-body reaction direct measurement is impossible, and therefore the reaction rate must be estimated theoretically. In this contribution I will discuss uncertainties in this reaction rate both at very low...

Group theoretic derivation of angular functions for the non-relativistic A-body problem in the K-harmonics approach

International Nuclear Information System (INIS)

Alcaras, J.A.C.; Ferreira, J.L.

1975-01-01

A derivation of an angular basis for the A-body problem, suitable for the K-harmonics method, is presented. Those angular functions are obtained from homogeneous and harmonic polynomials, which are completely specified by labels associated to eigenvalues of the Casimir invariants of subgroups of the 3(A-1)-dimensional orthogonal group, among them, the total angular momentum and its z-projection [pt

Maximal lattice free bodies, test sets and the Frobenius problem

DEFF Research Database (Denmark)

Jensen, Anders Nedergaard; Lauritzen, Niels; Roune, Bjarke Hammersholt

Maximal lattice free bodies are maximal polytopes without interior integral points. Scarf initiated the study of maximal lattice free bodies relative to the facet normals in a fixed matrix. In this paper we give an efficient algorithm for computing the maximal lattice free bodies of an integral m...... method is inspired by the novel algorithm by Einstein, Lichtblau, Strzebonski and Wagon and the Groebner basis approach by Roune....

Foreign Body Retrieval

Medline Plus

Full Text Available ... batteries, small toys or pieces of toys and fish bones. Swallowing of magnets can cause significant problems ... bodies like toothpicks. Small esophageal foreign bodies like fish bones also may be difficult to visualize. Additional ...

Treatment and ergonomics training of work-related lower back pain and body posture problems for nurses.

Science.gov (United States)

Jaromi, Melinda; Nemeth, Andrea; Kranicz, Janos; Laczko, Tamas; Betlehem, Jozsef

2012-06-01

The purpose of the study was to measure the effectiveness of a spine training programme (Back School) in nurses who have been living with chronic low back pain. It was hypothesised that active therapy, ergonomics and education called Back School will significantly decrease the pain intensity levels and improve the body posture of the study participants. A chronic low back pain is a significant work-related health problem among healthcare workers around the world. Proper body posture is essential for decreasing pain in healthcare workers who have history of chronic low back pain. By teaching proper body posture and with the creation of occupational settings that are 'spine-friendly' hospitals and other healthcare settings can significantly lower the suffering of their nursing staff. Single-blinded randomised controlled trial was utilised with six- and 12-months follow-up. The study was carried out at the University of Pecs, Faculty of Health Sciences from 2007 to 2008 involving 124 nurses with low back pain. Participants were randomly assigned to the study group (who have received ergonomics training and education called Back School) with an intervention conducted once a week for a six-week period. The control group received passive physiotherapy once a week for a six-week period. Further follow-up measurements were conducted at six and 12 months, respectively. The study variables and outcome measures were pain intensity and body posture (angle of thoracic kyphosis and lumbar lordosis). The pain intensity was investigated with the Visual Analogue Scale. Body posture was recorded and analysed with the Zebris biomechanical motion analysis system. The statistical analysis of repeated measures indicated a significant decrease in back pain intensity after the therapy in both groups, compared with measurements before the therapy; however, the BS group showed significantly better results during the six-month and one-year follow-up period. The biomechanical analysis of

A Four-phase Approach to a Timetabling Problem in Secondary Schools

NARCIS (Netherlands)

de Haan, P.; Landman, Ronald; Post, Gerhard F.; Ruizenaar, H.W.A.; Ruizenaar, Henri; Burke, E.K.; Rudová, H.

2006-01-01

Timetabling problems are present in all types of schools. The research in this area is still very active; of the 19 selected contributions of PATAT 2004 ([1]), 12 are dedicated to Educational Timetabling. These problems can often be modeled by a graph coloring problem. Here the vertices represent

Many-body scattering theory methods as a means for solving bound-state problems: Applications of arrangement-channel quantum mechanics

International Nuclear Information System (INIS)

Levin, F.S.; Krueger, H.

1977-01-01

We propose in this article that the non-Hermitian equations typical of some many-body scattering theories be used to help solve many-body bound-state problems. The basic idea is to exploit the channel nature of many-body bound states that must exist because bound states are obvious negative-energy extensions of scattering states. Since atomic, molecular, and nuclear systems all display multichannel effects for E > 0, at least through Pauli-principle effects if not through mass-transfer reactions, this use of positive-energy methods for solving bound-state problems could have wide applicability. The development used here is based on the channel-component-state method of the channel-coupling-array theory, recently described in detail for the E > 0 case, and various aspects of the formalism are discussed. Detailed calculations using simple approximations are discussed for H 2 + , one of the simplest systems displaying channel structure. Comparison with the exact, Born-Oppenheimer results of Wind show that the non-Hermitian-equation, channel-component values of the equilibrium separation and total binding energy are accurate to within 2%, while the dissociation energy is accurate to 10%. The resulting wave function is identical to that arising from the simplest MO calculation, for which these numbers are less accurate than the preceding by at least a factor of 3. We also show that identical particle symmetry for the H 2 + case reduces the pair of coupled (two-channel) equations to a single equation with an exchange term. Similar reductions will occur for larger numbers of identical particles, thus suggesting application of the formalism to atomic structure problems. A detailed analysis of the present numerical results, their general implications, and possible applications is also given

Physics of the Human Body

CERN Document Server

Herman, Irving P

2007-01-01

Physics of the Human Body comprehensively addresses the physical and engineering aspects of human physiology by using and building on first-year college physics and mathematics. Topics include the mechanics of the static body and the body in motion, the materials properties of the body, muscles in the body, the energetics of body metabolism, fluid flow in the cardiovascular and respiratory systems, the acoustics of sound waves in speaking and hearing, vision and the optics of the eye, the electrical properties of the body, and the basic engineering principles of feedback and control in regulating all aspects of function. The goal of this text is to understand physical issues concerning the human body, in part by developing and then using simple and subsequently more refined models of the macrophysics of the human body. Many chapters include a brief review of the necessary physical principles. There are problems at the end of each chapter; solutions to selected problems are also provided. This text is geared t...

Help-seeking intentions for early signs of mental illness and their associated factors: comparison across four kinds of health problems

Directory of Open Access Journals (Sweden)

Machi Suka

2016-04-01

Full Text Available Abstract Background Failure and delay in initial treatment contact for mental disorders has been recognized as an important public health problem. According to the concept of mental health literacy, recognition of symptoms is crucial to making decisions to seek or not seek professional help. The aims of this study were to investigate the types of health problems for which Japanese adults intend to seek help, their preferred sources of help, and the factors associated with help-seeking intentions. Methods A cross-sectional web-based survey was conducted in June 2014 among Japanese adults aged 20–59 years. A total of 3308 eligible respondents were included in this study. Help-seeking intentions were measured by listing potential sources of help (including ‘would not receive help’ and asking which ones would be chosen in four health conditions indicated by irritability, dizziness, insomnia, and depressed mood, respectively. Results In the case of dizziness, 85.9 % of the participants reported a positive help-seeking intention and 42.7 % gave first priority to seeking help from formal sources. These percentages were smaller in the cases of insomnia (75.4 and 25.0 %, depressed mood (74.9 and 18.7 %, and irritability (72.9 and 0.9 %. Multiple logistic regression analysis revealed that the factors significantly associated with help-seeking intentions were almost identical across the four health problems. In particular, perception of family and friends regarding help-seeking, psychiatric history, contact with people with mental illness, better health literacy, and neighborhood communicativeness were significantly associated with the overall help-seeking intention and also the help-seeking intention from formal sources for all the problems of dizziness, insomnia, and depressed mood. Conclusions The majority of participants indicated their intentions to seek help, but psychological problems (insomnia and depressed mood were less likely to

Help-seeking intentions for early signs of mental illness and their associated factors: comparison across four kinds of health problems.

Science.gov (United States)

Suka, Machi; Yamauchi, Takashi; Sugimori, Hiroki

2016-04-07

Failure and delay in initial treatment contact for mental disorders has been recognized as an important public health problem. According to the concept of mental health literacy, recognition of symptoms is crucial to making decisions to seek or not seek professional help. The aims of this study were to investigate the types of health problems for which Japanese adults intend to seek help, their preferred sources of help, and the factors associated with help-seeking intentions. A cross-sectional web-based survey was conducted in June 2014 among Japanese adults aged 20-59 years. A total of 3308 eligible respondents were included in this study. Help-seeking intentions were measured by listing potential sources of help (including 'would not receive help') and asking which ones would be chosen in four health conditions indicated by irritability, dizziness, insomnia, and depressed mood, respectively. In the case of dizziness, 85.9% of the participants reported a positive help-seeking intention and 42.7% gave first priority to seeking help from formal sources. These percentages were smaller in the cases of insomnia (75.4 and 25.0%), depressed mood (74.9 and 18.7%), and irritability (72.9 and 0.9%). Multiple logistic regression analysis revealed that the factors significantly associated with help-seeking intentions were almost identical across the four health problems. In particular, perception of family and friends regarding help-seeking, psychiatric history, contact with people with mental illness, better health literacy, and neighborhood communicativeness were significantly associated with the overall help-seeking intention and also the help-seeking intention from formal sources for all the problems of dizziness, insomnia, and depressed mood. The majority of participants indicated their intentions to seek help, but psychological problems (insomnia and depressed mood) were less likely to induce help-seeking intentions than a physical problem (dizziness). Besides

Positive effects, side effects, and adverse events of clinical holistic medicine. A review of Gerda Boyesen's nonpharmaceutical mind-body medicine (biodynamic body-psychotherapy) at two centers in the United Kingdom and Germany.

Science.gov (United States)

Allmer, Charlotte; Ventegodt, Søren; Kandel, Isack; Merrick, Joav

2009-01-01

To review adverse events of intensive, clinical holistic medicine (CHM) as it is practiced in holistic body-psychotherapy in England and Germany. Gerda Boyesen's "biodynamic body-psychotherapy" (BBP) is an intensive type of holistic mind-body medicine used by Boyesen at two centers. About 13,500 patients were treated during 1985-2005 period and studied for side effects and adverse events. The first author worked closely with Boyesen 1995-2005 with full insight in all aspects of the therapy and provided the data on side-effects. Therapy helped chronic patients with physical, psychological, sexual, psychiatric and existential problems to improve health, ability, and quality of life (NNT (number needed to treat) = 1-3). Effective in the treatment of mentally ill patients (schizophrenia, anxiety, poor mental health, low general ability). For retraumatization, brief reactive psychosis, depression, depersonalization and derealization, implanted memories, side effects from manipulations of the body, suicide/suicide attempts, hospitalization for physical and mental health problem during or 90 days after treatment, NNH (number needed to harm) > 13,500. Intensive, holistic non-drug medicine is helpful for physical, sexual, psychological, psychiatric and existential problems and is completely safe for the patient. The therapeutic value TV = NNH/NNT > 5,000. Altogether about 18,000 patients treated with different subtypes of CHM in four different countries have now been evaluated for effects, side effects and adverse events, with similar results.

Scattering integral equations and four nucleon problem. Four nucleon bound states and scattering

International Nuclear Information System (INIS)

Narodetskij, I.M.

1981-01-01

Existing results from the application of integral equation technique four-nucleon bound states and scattering are reviewed. The purpose of this review is to provide a clear and elementary introduction in the integral equation method and to demonstrate its usefulness in physical applications. Developments in the actual numerical solutions of Faddeev-Yakubovsky type equations are such that a detailed comparison can be made with experiment. Bound state calculations indicate that a nonrelativistic description with pairwise nuclear forces does not suffice and additional degrees of freedom are noted [ru

Maternal self-confidence during the first four months postpartum and its association with anxiety and early infant regulatory problems.

Science.gov (United States)

Matthies, Lina Maria; Wallwiener, Stephanie; Müller, Mitho; Doster, Anne; Plewniok, Katharina; Feller, Sandra; Sohn, Christof; Wallwiener, Markus; Reck, Corinna

2017-11-01

Maternal self-confidence has become an essential concept in understanding early disturbances in the mother-child relationship. Recent research suggests that maternal self-confidence may be associated with maternal mental health and infant development. The current study investigated the dynamics of maternal self-confidence during the first four months postpartum and the predictive ability of maternal symptoms of depression, anxiety, and early regulatory problems in infants. Questionnaires assessing symptoms of depression (Edinburgh Postnatal Depression Scale), anxiety (State-Trait Anxiety Inventory), and early regulatory problems (Questionnaire for crying, sleeping and feeding) were completed in a sample of 130 women at three different time points (third trimester (T1), first week postpartum (T2), and 4 months postpartum (T3). Maternal self-confidence increased significantly over time. High maternal trait anxiety and early infant regulatory problems negatively contributed to the prediction of maternal self-confidence, explaining 31.8% of the variance (R=.583, F 3,96 =15.950, pself-confidence, regulatory problems in infants, and maternal mental distress. There is an urgent need for appropriate programs to reduce maternal anxiety and to promote maternal self-confidence in order to prevent early regulatory problems in infants. Copyright © 2017 Elsevier Inc. All rights reserved.

Problems of allometric scaling analysis: examples from mammalian reproductive biology.

Science.gov (United States)

Martin, Robert D; Genoud, Michel; Hemelrijk, Charlotte K

2005-05-01

Biological scaling analyses employing the widely used bivariate allometric model are beset by at least four interacting problems: (1) choice of an appropriate best-fit line with due attention to the influence of outliers; (2) objective recognition of divergent subsets in the data (allometric grades); (3) potential restrictions on statistical independence resulting from phylogenetic inertia; and (4) the need for extreme caution in inferring causation from correlation. A new non-parametric line-fitting technique has been developed that eliminates requirements for normality of distribution, greatly reduces the influence of outliers and permits objective recognition of grade shifts in substantial datasets. This technique is applied in scaling analyses of mammalian gestation periods and of neonatal body mass in primates. These analyses feed into a re-examination, conducted with partial correlation analysis, of the maternal energy hypothesis relating to mammalian brain evolution, which suggests links between body size and brain size in neonates and adults, gestation period and basal metabolic rate. Much has been made of the potential problem of phylogenetic inertia as a confounding factor in scaling analyses. However, this problem may be less severe than suspected earlier because nested analyses of variance conducted on residual variation (rather than on raw values) reveals that there is considerable variance at low taxonomic levels. In fact, limited divergence in body size between closely related species is one of the prime examples of phylogenetic inertia. One common approach to eliminating perceived problems of phylogenetic inertia in allometric analyses has been calculation of 'independent contrast values'. It is demonstrated that the reasoning behind this approach is flawed in several ways. Calculation of contrast values for closely related species of similar body size is, in fact, highly questionable, particularly when there are major deviations from the best

Two-body problem in general relativity: A heuristic guide for the Einstein-Rosen bridge and EPR paradox

OpenAIRE

Weinstein, Galina

2015-01-01

Between 1935 and 1936, Einstein was occupied with the Schwarzschild solution and the singularity within it while working in Princeton on the unified field theory and with his assistant Nathan Rosen, on the theory of the Einstein-Rosen bridges. He was also occupied with quantum theory. He believed that quantum theory was an incomplete representation of real things. Together with Rosen and Boris Podolsky he invented the EPR paradox. I demonstrate that the two-body problem in general relativity ...

Nested convex bodies are chaseable

NARCIS (Netherlands)

N. Bansal (Nikhil); M. Böhm (Martin); M. Eliáš (Marek); G. Koumoutsos (Grigorios); S.W. Umboh (Seeun William)

2018-01-01

textabstractIn the Convex Body Chasing problem, we are given an initial point v0 2 Rd and an online sequence of n convex bodies F1; : : : ; Fn. When we receive Fi, we are required to move inside Fi. Our goal is to minimize the total distance traveled. This fundamental online problem was first

Communication Reducing Algorithms for Distributed Hierarchical N-Body Problems with Boundary Distributions

KAUST Repository

AbdulJabbar, Mustafa Abdulmajeed

2017-05-11

Reduction of communication and efficient partitioning are key issues for achieving scalability in hierarchical N-Body algorithms like Fast Multipole Method (FMM). In the present work, we propose three independent strategies to improve partitioning and reduce communication. First, we show that the conventional wisdom of using space-filling curve partitioning may not work well for boundary integral problems, which constitute a significant portion of FMM’s application user base. We propose an alternative method that modifies orthogonal recursive bisection to relieve the cell-partition misalignment that has kept it from scaling previously. Secondly, we optimize the granularity of communication to find the optimal balance between a bulk-synchronous collective communication of the local essential tree and an RDMA per task per cell. Finally, we take the dynamic sparse data exchange proposed by Hoefler et al. [1] and extend it to a hierarchical sparse data exchange, which is demonstrated at scale to be faster than the MPI library’s MPI_Alltoallv that is commonly used.

Body dysmorphic factors and mental health problems in people seeking rhinoplastic surgery.

Science.gov (United States)

Javanbakht, M; Nazari, A; Javanbakht, A; Moghaddam, L

2012-02-01

There has been increasing number of requests for cosmetic rhinoplastic surgery among Iranian people in different age groups in recent years. One risk for people who undergo such plastic operations is the presence of body dysmorphic disorder (BDD), which can complicate the result and decrease the rate of satisfaction from surgery. This study aimed to investigate mental health problems in people seeking rhinoplastic surgery. In this case-control study, the scores of General Health Questionnaire (GHQ) and DCQ (Dysmorphic Concerns Questionnaire) were obtained from 50 individuals who were candidates for rhinoplasty, and the results were compared with a normal control group. The total GHQ score and scores in anxiety, depression, and social dysfunction sub-scales were higher among the study group. This was the same for the DCQ score. However, the scores of somatization sub-scale of GHQ were not significantly different between the two groups. Psychiatric evaluation of candidates for rhinoplasty seems necessary for prevention of unnecessary and repetitive surgical operations.

Explicit demonstration of the convergence of the close-coupling method for a Coulomb three-body problem

International Nuclear Information System (INIS)

Bray, I.; Stelbovics, A.T.

1992-01-01

Convergence as a function of the number of states is studied and demonstrated for the Poet-Temkin model of electron-hydrogen scattering. In this Coulomb three-body problem only the l=0 partial waves are treated. By taking as many as thirty target states, obtained by diagonalizing the target Hamiltonian in a Laguerre basis, complete agreement with the smooth results of Poet is obtained at all energies. We show that the often-encountered pseudoresonance features in the cross sections are simply an indication of an inadequate target state representation

Physics of the human body

CERN Document Server

Herman, Irving P

2016-01-01

This book comprehensively addresses the physics and engineering aspects of human physiology by using and building on first-year college physics and mathematics. Topics include the mechanics of the static body and the body in motion, the mechanical properties of the body, muscles in the body, the energetics of body metabolism, fluid flow in the cardiovascular and respiratory systems, the acoustics of sound waves in speaking and hearing, vision and the optics of the eye, the electrical properties of the body, and the basic engineering principles of feedback and control in regulating all aspects of function. The goal of this text is to clearly explain the physics issues concerning the human body, in part by developing and then using simple and subsequently more refined models of the macrophysics of the human body. Many chapters include a brief review of the underlying physics. There are problems at the end of each chapter; solutions to selected problems are also provided. This second edition enhances the treat...

Uncertainty relations and reduced density matrices: Mapping many-body quantum mechanics onto four particles

Science.gov (United States)

Mazziotti, David A.; Erdahl, Robert M.

2001-04-01

For the description of ground-state correlation phenomena an accurate mapping of many-body quantum mechanics onto four particles is developed. The energy for a quantum system with no more than two-particle interactions may be expressed in terms of a two-particle reduced density matrix (2-RDM), but variational optimization of the 2-RDM requires that it corresponds to an N-particle wave function. We derive N-representability conditions on the 2-RDM that guarantee the validity of the uncertainty relations for all operators with two-particle interactions. One of these conditions is shown to be necessary and sufficient to make the RDM solutions of the dispersion condition equivalent to those from the contracted Schrödinger equation (CSE) [Mazziotti, Phys. Rev. A 57, 4219 (1998)]. In general, the CSE is a stronger N-representability condition than the dispersion condition because the CSE implies the dispersion condition as well as additional N-representability constraints from the Hellmann-Feynman theorem. Energy minimization subject to the representability constraints is performed for a boson model with 10, 30, and 75 particles. Even when traditional wave-function methods fail at large perturbations, the present method yields correlation energies within 2%.

Geometric chaos indicators and computations of the spherical hypertube manifolds of the spatial circular restricted three-body problem

Science.gov (United States)

Guzzo, Massimiliano; Lega, Elena

2018-06-01

The circular restricted three-body problem has five relative equilibria L1 ,L2, . . . ,L5. The invariant stable-unstable manifolds of the center manifolds originating at the partially hyperbolic equilibria L1 ,L2 have been identified as the separatrices for the motions which transit between the regions of the phase-space which are internal or external with respect to the two massive bodies. While the stable and unstable manifolds of the planar problem have been extensively studied both theoretically and numerically, the spatial case has not been as deeply investigated. This paper is devoted to the global computation of these manifolds in the spatial case with a suitable finite time chaos indicator. The definition of the chaos indicator is not trivial, since the mandatory use of the regularizing Kustaanheimo-Stiefel variables may introduce discontinuities in the finite time chaos indicators. From the study of such discontinuities, we define geometric chaos indicators which are globally defined and smooth, and whose ridges sharply approximate the stable and unstable manifolds of the center manifolds of L1 ,L2. We illustrate the method for the Sun-Jupiter mass ratio, and represent the topology of the asymptotic manifolds using sections and three-dimensional representations.

Can "contamination" occur in body bags?-The example of background fibres in body bags used in Australia.

Science.gov (United States)

Schwendener, Giuliana; Moret, Sébastien; Cavanagh-Steer, Karen; Roux, Claude

2016-09-01

Impurities that are transferred to a crime scene or a body can have a significant negative impact on the investigation if the existence of the contamination is not known, and the source of the contamination is not identified. Forensic consumables, such as DNA swabs, have been known to have caused contaminations, wrongfully linking crimes throughout Europe. In that context, this study focused on body bags, widely used to transfer a corpse from the crime scene to the morgue. Our preliminary survey showed that several countries and Australian Jurisdictions are conducting the sampling of trace evidence at the morgue after the transportation of the body. Potential impurities present in body bags could thus interfere with pertinent traces. The aim of this work was to qualify and quantify the background contamination of trace evidence in body bags used within Australia. Fifteen body bags from four Australian Jurisdictions or laboratories were searched for micro traces. Impurities such as fibres and unidentified particles were detected in each examined body bag, with an estimated average of 3603 coloured fibres and 1429 unidentified particles. This number of fibres is similar to the amount found on a vinyl cinema seat in other studies. Various other contaminants such as pieces of fabric, hairs, parts of insects or feathers were also observed. It is hypothesised that these impurities are introduced during the manufacturing process. This high number of impurities can lead to incorrect conclusions and misleading investigative leads. This paper presents an overview of the problems these impurities can cause and proposes several strategies to prevent future issues. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

In-vivo determination of total body water and lean body mass in subjects by deuterium dilution

International Nuclear Information System (INIS)

Blagojevic, N.; Allen, B.J.; Baur, L.; Gaskin, K.

1988-01-01

Total body water (TBW) estimation is one of a number of basic techniques required for the determination of body composition in normal and malnourished subjects. When combined with total body nitrogen (TBN) analysis by prompt gamma neutron activation, an accurate compartmental model of in vivo body composition can be formed, providing valuable nutritional and other data. This study examines the role of TBW on its own in evaluating lean body mass. Total body water was studied in six male and five female subjects using deuterium oxide and a Fourier transform infrared spectrometer. The lean body mass calculated from the results was compared with the lean body mass deduced from established total body nitrogen measurements. A four-compartment model was also used to calculate lean body mass. Excellent agreement was shown between lean body mass derived from TBW, the four-compartment model and TBN. Hence, TBW can provide a fast, cost-efficient method for evaluating normal subjects. However, for disease-induced malnutrition, or highly developed athletes, both TBN and TBW measurements are essential to establish an accurate picture of their body composition. TBW measurements alone can monitor the hydration state of patients and as such have a useful diagnostic value

In-vivo determination of total body water and lean body mass in subjects by deuterium dilution

Energy Technology Data Exchange (ETDEWEB)

Blagojevic, N; Allen, B J; Baur, L; Gaskin, K

1988-12-01

Total body water (TBW) estimation is one of a number of basic techniques required for the determination of body composition in normal and malnourished subjects. When combined with total body nitrogen (TBN) analysis by prompt gamma neutron activation, an accurate compartmental model of in vivo body composition can be formed, providing valuable nutritional and other data. This study examines the role of TBW on its own in evaluating lean body mass. Total body water was studied in six male and five female subjects using deuterium oxide and a Fourier transform infrared spectrometer. The lean body mass calculated from the results was compared with the lean body mass deduced from established total body nitrogen measurements. A four-compartment model was also used to calculate lean body mass. Excellent agreement was shown between lean body mass derived from TBW, the four-compartment model and TBN. Hence, TBW can provide a fast, cost-efficient method for evaluating normal subjects. However, for disease-induced malnutrition, or highly developed athletes, both TBN and TBW measurements are essential to establish an accurate picture of their body composition. TBW measurements alone can monitor the hydration state of patients and as such have a useful diagnostic value.

Suitable configurations for triangular formation flying about collinear libration points under the circular and elliptic restricted three-body problems

Science.gov (United States)

Ferrari, Fabio; Lavagna, Michèle

2018-06-01

The design of formations of spacecraft in a three-body environment represents one of the most promising challenges for future space missions. Two or more cooperating spacecraft can greatly answer some very complex mission goals, not achievable by a single spacecraft. The dynamical properties of a low acceleration environment such as the vicinity of libration points associated to a three-body system, can be effectively exploited to design spacecraft configurations able of satisfying tight relative position and velocity requirements. This work studies the evolution of an uncontrolled formation orbiting in the proximity of periodic orbits about collinear libration points under the Circular and Elliptic Restricted Three-Body Problems. A three spacecraft triangularly-shaped formation is assumed as a representative geometry to be investigated. The study identifies initial configurations that provide good performance in terms of formation keeping, and investigates key parameters that control the relative dynamics between the spacecraft within the three-body system. Formation keeping performance is quantified by monitoring shape and size changes of the triangular formation. The analysis has been performed under five degrees of freedom to define the geometry, the orientation and the location of the triangle in the synodic rotating frame.

Separable pole expansions in four-nucleon bound state calculations

International Nuclear Information System (INIS)

Sofianos, S.A.; Fiedeldey, H.; Haberzettl, H.; Sandhas, W.

1982-04-01

We compare the utility of the Generalized Unitary Pole Expansion (GUPE) and the Energy-Dependent Pole Expansion (EDPE) for the three-body subsystem amplitudes in four-body state calculations for a variety of separable and local nucleon-nucleon interactions. It is found that, with the EDPE, the four-body binding energy is well reproduced with only two terms each for the (2+2)- and the (3+1)-subsystem, respectively, while the GUPE requires three terms for the (3+1)-channel and four terms for the (2+2)-channel. We thus conclude that pole dominance is of greater importance for the GUPE than for EDPE, which works equally well for both types of subsystems. It is found that both methods, in particular the EDPE, converge more rapidly with increasing repulsion in the two-body interaction, i.e. the more realistic the interaction becomes. Both expansions require similar computing times for a converged calculation and are about 15-20 times faster than the widely used Hilbert-Schmidt Expansion (HSE). The respective merits of the two pole expansions are discussed and compared with the HSE. (orig.)

Sexuality and body image in long-term survivors of testicular cancer

DEFF Research Database (Denmark)

Rossen, Philip; Pedersen, Anette Fischer; Zachariae, Robert

2012-01-01

Hospital, Denmark, from 1990 to 2000 was conducted. A total of 401 survivors (mean age: 46.6years; response rate: 66%) completed questionnaires concerning sexuality and changes in body image. Based on the treatment received, patients were categorised into one of four groups: surveillance, radiotherapy......OBJECTIVE: This study explores sexual function and the influence of different treatment modalities on sexual function and body image among long-term survivors of testicular cancer (TCSs). METHODS: A long-term follow-up assessment of all testicular cancer patients treated at Aarhus University......, chemotherapy, or chemotherapy supplemented with retroperitoneal lymph node dissection (RPLND). RESULTS: Sexual dysfunctions were reported: 24% reduced sexual interest, 43% reduced sexual activity, 14% reduced sexual enjoyment, 18% erectile dysfunction, 7% ejaculatory problems and 3% increased sexual discomfort...

An improved Four-Russians method and sparsified Four-Russians algorithm for RNA folding.

Science.gov (United States)

Frid, Yelena; Gusfield, Dan

2016-01-01

The basic RNA secondary structure prediction problem or single sequence folding problem (SSF) was solved 35 years ago by a now well-known [Formula: see text]-time dynamic programming method. Recently three methodologies-Valiant, Four-Russians, and Sparsification-have been applied to speedup RNA secondary structure prediction. The sparsification method exploits two properties of the input: the number of subsequence Z with the endpoints belonging to the optimal folding set and the maximum number base-pairs L. These sparsity properties satisfy [Formula: see text] and [Formula: see text], and the method reduces the algorithmic running time to O(LZ). While the Four-Russians method utilizes tabling partial results. In this paper, we explore three different algorithmic speedups. We first expand the reformulate the single sequence folding Four-Russians [Formula: see text]-time algorithm, to utilize an on-demand lookup table. Second, we create a framework that combines the fastest Sparsification and new fastest on-demand Four-Russians methods. This combined method has worst-case running time of [Formula: see text], where [Formula: see text] and [Formula: see text]. Third we update the Four-Russians formulation to achieve an on-demand [Formula: see text]-time parallel algorithm. This then leads to an asymptotic speedup of [Formula: see text] where [Formula: see text] and [Formula: see text] the number of subsequence with the endpoint j belonging to the optimal folding set. The on-demand formulation not only removes all extraneous computation and allows us to incorporate more realistic scoring schemes, but leads us to take advantage of the sparsity properties. Through asymptotic analysis and empirical testing on the base-pair maximization variant and a more biologically informative scoring scheme, we show that this Sparse Four-Russians framework is able to achieve a speedup on every problem instance, that is asymptotically never worse, and empirically better than achieved by

Smart Body or the Problem of Human Corporeality Development in the Context of Outsourced Life. Part 1.

Directory of Open Access Journals (Sweden)

Smirnov S.A.,

2016-04-01

Full Text Available The paper analyses the issue of a popular trend called ‘life outsourcing’ which affects the structure of personality in an individual. Basing on the works of L.S. Vygotsky and others, the author explores the methodology of the concept of cultural development as a process of formation of an embodied personality or non-organic body. He outlines the search for the approaches to the process of cultural development and for its descriptions in terms of personality construction and ‘soul organism’ which can be traced down in Vygotsky’s works. According to these works, cultural-historical psychology employed a concept of tool- and activity-based personality body, or soul organism. As it is argued in the paper, this concept is to a certain extent incomplete. What happens to the individual’s personality body in a situation of increasingly popular life outsourcing, i.e. when more and more basic functions and actions are transferred from the individual to various devices? Using artistic creativity as an example, the author explores the artist’s transition from working with natural materials to working with devices and focuses on the problem of the artist’s ‘smart body’ losing the feeling of texture and form. The issue is to be continued in the second paper.

Search for top squarks decaying via four-body or chargino-mediated modes in the single-lepton final state at $\\sqrt{s} = 13~\\mathrm{TeV}$

CERN Document Server

CMS Collaboration

2017-01-01

A search for top squark pair production in a compressed scenario, where the mass difference between the top squark and the lightest supersymmetric particle (LSP) is smaller than the mass of the W boson, is presented. The dataset is comprised of proton-proton collisions, recorded by the CMS experiment at a centre-of-mass energy of $13~\\mathrm{TeV}$ and corresponding to an integrated luminosity of $35.9~\\mathrm{fb}^{-1}$. In this search two decay modes of the top squark are considered: a four-body decay into a b quark, two additional fermions, and an LSP, and a decay via an intermediate chargino. Events are selected using the presence of a high-momentum jet, significant missing transverse energy and a low transverse momentum electron or muon. Two analysis techniques are used: a sequential selection based on the most discriminating observables, and a multivariate technique targeting the four-body decays. No evidence for the production of top squarks is found and mass limits at $95\\%$ confidence level are set tha...

Body segments decoupling in sitting: control of body posture from automatic chair adjustments

NARCIS (Netherlands)

van Geffen, P.; Molier, B.I.; Reenalda, Jasper; Veltink, Petrus H.; Koopman, Hubertus F.J.M.

2008-01-01

Background Individuals who cannot functionally reposition themselves adopt a passive body posture and suffer from physical discomfort in long-term sitting. To regulate body load and to prevent sitting related mobility problems, proper posture control is important. The inability to reposition

A translationally invariant RPA-calculation for 16O on the basis of an algebraic solution of the many-body oscillator problem

International Nuclear Information System (INIS)

Schwesinger, B.

1978-01-01

The solution of the many-body oscillator problem is used as a basis for a RPA-calculation of 16 O. The calculation is performed in a LS-coupling scheme with an interaction containing central, spin-orbit and tensor forces. The main differences with conventional RPA-calculations occur for the transition probabilities. (orig.) [de

Beautiful Models: 70 Years of Exactly Solved Quantum Many-Body Problems

International Nuclear Information System (INIS)

Batchelor, M T

2005-01-01

-Sutherland models and models with ground state wavefunctions of product form. One of my favourites is chapter 7, dealing with the consistency conditions for two-body scattering operators involving the Yang-Baxter equations. The strength of the book lies in the pedagogical approach, with the underlying emphasis on integrability and the Bethe ansatz. Sutherland brings his own insights to these problems, and as such there is also something to be gained by specialist readers. Given the author's aims, the book is not meant to be a complete and historic review of the field. Rather, the intention is that the general references given will point the reader in the right direction. Sutherland quite wisely gives an up-front apology to any authors he has left out. Certainly such historical omissions can be found. Two obvious examples are the origins of the condition of non-diffraction and twisted boundary conditions. Setting such minor points aside, Beautiful Models is a most welcome book. It does a great service to a fascinating, enduring and increasingly relevant field by highlighting not only the beauty, but also the magic of integrability. (book review)

Beautiful Models: 70 Years of Exactly Solved Quantum Many-Body Problems

Energy Technology Data Exchange (ETDEWEB)

Batchelor, M T [Department of Theoretical Physics, RSPSE and Department of Mathematics, MSI, Australian National University, Canberra ACT 0200 (Australia)

2005-04-08

Heisenberg spin chain, the Hubbard model, exchange models, the Calogero-Sutherland models and models with ground state wavefunctions of product form. One of my favourites is chapter 7, dealing with the consistency conditions for two-body scattering operators involving the Yang-Baxter equations. The strength of the book lies in the pedagogical approach, with the underlying emphasis on integrability and the Bethe ansatz. Sutherland brings his own insights to these problems, and as such there is also something to be gained by specialist readers. Given the author's aims, the book is not meant to be a complete and historic review of the field. Rather, the intention is that the general references given will point the reader in the right direction. Sutherland quite wisely gives an up-front apology to any authors he has left out. Certainly such historical omissions can be found. Two obvious examples are the origins of the condition of non-diffraction and twisted boundary conditions. Setting such minor points aside, Beautiful Models is a most welcome book. It does a great service to a fascinating, enduring and increasingly relevant field by highlighting not only the beauty, but also the magic of integrability. (book review)

Biodynamics of deformable human body motion

Science.gov (United States)

Strauss, A. M.; Huston, R. L.

1976-01-01

The objective is to construct a framework wherein the various models of human biomaterials fit in order to describe the biodynamic response of the human body. The behavior of the human body in various situations, from low frequency, low amplitude vibrations to impact loadings in automobile and aircraft crashes, is very complicated with respect to all aspects of the problem: materials, geometry and dynamics. The materials problem is the primary concern, but the materials problem is intimately connected with geometry and dynamics.

Modeling Human Body Using Four-Pole Debye Model in Piecewise Linear Recursive Convolution FDTD Method for the SAR Calculation in the Case of Vehicular Antenna

Directory of Open Access Journals (Sweden)

Ammar Guellab

2018-01-01

Full Text Available We propose an efficient finite difference time domain (FDTD method based on the piecewise linear recursive convolution (PLRC technique to evaluate the human body exposure to electromagnetic (EM radiation. The source of radiation considered in this study is a high-power antenna, mounted on a military vehicle, covering a broad band of frequency (100 MHz–3 GHz. The simulation is carried out using a nonhomogeneous human body model which takes into consideration most of the internal body tissues. The human tissues are modeled by a four-pole Debye model which is derived from experimental data by using particle swarm optimization (PSO. The human exposure to EM radiation is evaluated by computing the local and whole-body average specific absorption rate (SAR for each occupant. The higher in-tissue electric field intensity points are localized, and the SAR values are compared with the crew safety standard recommendations. The accuracy of the proposed PLRC-FDTD approach and the matching of the Debye model with the experimental data are verified in this study.

Metallic Foreign Body in the Foot

Directory of Open Access Journals (Sweden)

Firat Ozan

2016-04-01

Full Text Available Aim: A foreign body injury of the foot is a frequently encountered problem. These foreign bodies can lead to various complications in the affected tissues, and their removal can be difficult and time consuming. Therefore, the removal of a foreign body requires good preoperative preparations. The surgical treatment results of patients with a foreign body, identified as a sewing needle, that had penetrated their foot were evaluated. Material and Method: Thirty-four patients (11 males, 23 females; mean age, 30.2 ± 18.6 years who were surgically treated between 2011 and 2013 were included. Data concerning the affected limb, placement of the needle, imaging techniques, season when the injury occurred, time between medical intervention and injury, anaesthesia type, fluoroscopy of use during surgery and surgical complications were analyzed. Results: A sewing needle had penetrated the right foot of 20 (58.8% patients and the left foot of 14 (41.1% patients. Broken needles were found in the toes of 14 (41.1% patients, in the middle of the foot of 12 (35.2% patients and in the heel area of 8 (23.5% patients. The injuries occurred in summer in 13 (38.2% patients, in winter in seven (20.6% patients, in spring in one (2.9% patient and in autumn in 13 (38.2% patients. Needle penetration had occurred in 28 (82.3% patients at home and 6 (17.6% patients outside of the home environment. The average follow-up time was 8.9 ± 2.8 months. Discussion: Removal of foreign bodies from the foot requires good preoperative preparations. Foreign bodies can lead to various complications in the affected tissues. It is important to perform detailed physical and radiological examinations to obtain good treatment results in these patients.

Four fermion interaction near four dimensions

International Nuclear Information System (INIS)

Zinn-Justin, J.

1991-01-01

It is known that field theories with attractive four-point fermion interactions can produce scalar bound states: Fermion mass generation by spontaneous chiral symmetry breaking associated with such fermion bound states provides an attractive mechanism for building models of composite Higgs bosons. The ratio of fermion and boson masses can then be predicted while it seems to be a free parameter in similar models where a boson field explicitly appears in the action. The main problem is that the corresponding models are renormalizable only in two dimensions, in contrast with models with explicit bosons. Many fermion models with four-point interaction are asymptotically free in two dimensions and then behave also like renormalizable models in higher dimensions, at least within the framework of some 1/N expansion. On the other hand mass ratio predictions also follow in the models with explicit bosons, when they have an IR fixed point, from the additional natural assumption that coupling constants have generic values at the cut-off scale. To the model with a four fermion interaction one can associate an effective model containing an additional scalar field, renormalizable in four dimensions, which has the same large distance, small momentum physics, at least to all orders in some 1/N expansion. Even the leading corrections corresponding to irrelevant or marginal operators are identical. This property is important in four dimensions where the IR fixed point coupling constants vanish: The correction amplitudes can be varied by changing the coupling constants in the renormalizable model and the cut-off function in the perturbatively non-renormalizable model. We shall consider here for definiteness only the Gross-Neveu model but it will be clear that the arguments are more general

Body modification and substance use in adolescents: is there a link?

Science.gov (United States)

Brooks, Traci L; Woods, Elizabeth R; Knight, John R; Shrier, Lydia A

2003-01-01

To describe the characteristics of body modification among adolescents and to determine whether adolescents who engage in body modification are more likely to screen positive for alcohol and other drug problems than those who do not. Adolescents aged 14 to 18 years presenting to an urban adolescent clinic for routine health care completed a questionnaire about body modification and a substance use assessment battery that included the 17-item Problem Oriented Screening Instrument for Teenagers Alcohol/Drug Use and Abuse Scale (POSIT-ADS). Body modification was defined as piercings (other than one pair of bilateral earlobe piercings in females), tattoos, scarification, and branding. Problem substance use was defined as a POSIT-ADS score > or =1. Data were analyzed using logistic regression to determine whether the presence of body modification was an independent predictor of problem substance use. The 210 participants had a mean (+/- SD) age of 16.0 (+/- 1.4) years and 63% were female. One hundred adolescents (48%) reported at least one body modification; girls were more likely than boys to have body modification (59% vs. 28%, p branding; 21 (10%) had more than one type of body modification. These were in a variety of locations, most commonly the ear and the nose (piercings) or the extremities (tattoos). One-third of the sample (33%) screened positive for problem substance use on the POSIT-ADS questionnaire. Controlling for age, adolescents with body modification had 3.1 times greater odds of problem substance use than those without body modification (95% CI 1.7, 5.8). Body modification was associated with self-reported problem alcohol and other drug use among middle adolescents presenting for primary care. More research is needed to determine the clinical and sociocultural significance of body modification and its relationship to substance use in this population. Copyright Society for Adolescent Medicine, 2003

Mechanics of deformable bodies

CERN Document Server

Sommerfeld, Arnold Johannes Wilhelm

1950-01-01

Mechanics of Deformable Bodies: Lectures on Theoretical Physics, Volume II covers topics on the mechanics of deformable bodies. The book discusses the kinematics, statics, and dynamics of deformable bodies; the vortex theory; as well as the theory of waves. The text also describes the flow with given boundaries. Supplementary notes on selected hydrodynamic problems and supplements to the theory of elasticity are provided. Physicists, mathematicians, and students taking related courses will find the book useful.

Measured body composition and geometrical data of four ``virtual family'' members for thermoregulatory modeling

Science.gov (United States)

Xu, Xiaojiang; Rioux, Timothy P.; MacLeod, Tynan; Patel, Tejash; Rome, Maxwell N.; Potter, Adam W.

2017-03-01

The purpose of this paper is to develop a database of tissue composition, distribution, volume, surface area, and skin thickness from anatomically correct human models, the virtual family. These models were based on high-resolution magnetic resonance imaging (MRI) of human volunteers, including two adults (male and female) and two children (boy and girl). In the segmented image dataset, each voxel is associated with a label which refers to a tissue type that occupies up that specific cubic millimeter of the body. The tissue volume was calculated from the number of the voxels with the same label. Volumes of 24 organs in body and volumes of 7 tissues in 10 specific body regions were calculated. Surface area was calculated from the collection of voxels that are touching the exterior air. Skin thicknesses were estimated from its volume and surface area. The differences between the calculated and original masses were about 3 % or less for tissues or organs that are important to thermoregulatory modeling, e.g., muscle, skin, and fat. This accurate database of body tissue distributions and geometry is essential for the development of human thermoregulatory models. Data derived from medical imaging provide new effective tools to enhance thermal physiology research and gain deeper insight into the mechanisms of how the human body maintains heat balance.

PLANNING VESSEL BODY SECTION PRODUCTION

Directory of Open Access Journals (Sweden)

A. G. Grivachevsky

2015-01-01

Full Text Available A problem of planning production of a vessel body section is considered. The problem is reduced to the classic Johnson’s tree-machine flow-shop scheduling problem. A genetic algorithm and computer experiment to compare efficiency of this algorithm and the algorithm of full enumeration are described.

Lewy Body Disease

Science.gov (United States)

... range of symptoms, including Changes in alertness and attention Hallucinations Problems with movement and posture Muscle stiffness Confusion Loss of memory Lewy body disease can be hard to diagnose, ...

Measurement of body potassium with a whole-body counter: relationship between lean body mass and resting energy expenditure

International Nuclear Information System (INIS)

Jensen, M.D.; Braun, J.S.; Vetter, R.J.; Marsh, H.M.

1988-01-01

We conducted studies to determine whether the Mayo whole-body counter could be used to measure body potassium, and thus lean body mass (LBM), and whether moderate obesity alters resting energy expenditure when corrected for LBM. Twenty-four nonobese and 18 moderately obese adults underwent body potassium (40K) counting, as well as tritiated water space measurement and indirect calorimetry. LBM values predicted from 40K counting and tritiated water space measurements were highly correlated (P = 0.001; r = 0.88). Resting energy expenditure was closely related to LBM (P less than 0.0001; r = 0.78): kcal/day = 622 kcal + (LBM.20.0 kcal/kg LBM). In this relationship, the obese subjects did not differ from nonobese subjects. In summary, the Mayo whole-body counter can accurately measure LBM, and moderate obesity has no detectable effect on corrected resting energy expenditure

Application of the Least Squares Method in Axisymmetric Biharmonic Problems

Directory of Open Access Journals (Sweden)

Vasyl Chekurin

2016-01-01

Full Text Available An approach for solving of the axisymmetric biharmonic boundary value problems for semi-infinite cylindrical domain was developed in the paper. On the lateral surface of the domain homogeneous Neumann boundary conditions are prescribed. On the remaining part of the domain’s boundary four different biharmonic boundary pieces of data are considered. To solve the formulated biharmonic problems the method of least squares on the boundary combined with the method of homogeneous solutions was used. That enabled reducing the problems to infinite systems of linear algebraic equations which can be solved with the use of reduction method. Convergence of the solution obtained with developed approach was studied numerically on some characteristic examples. The developed approach can be used particularly to solve axisymmetric elasticity problems for cylindrical bodies, the heights of which are equal to or exceed their diameters, when on their lateral surface normal and tangential tractions are prescribed and on the cylinder’s end faces various types of boundary conditions in stresses in displacements or mixed ones are given.

Senses of body image in adolescents in elementary school.

Science.gov (United States)

Silva, Maria Lídia de Abreu; Taquette, Stella Regina; Coutinho, Evandro Silva Freire

2014-06-01

To comprehend the perception of body image in adolescence. A qualitative study was conducted with eight focus groups with 96 students of both sexes attending four public elementary school institutions in the city of Rio de Janeiro, Southeastern Brazil, in 2013. An interview guide with questions about the adolescents' feelings in relation to: their bodies, standards of idealized beauty, practice of physical exercise and sociocultural influences on self-image. In the data analysis we sought to understand and interpret the meanings and contradictions of narratives, understanding the subjects' context and reasons and the internal logic of the group. Three thematic categories were identified. The influence of media on body image showed the difficulty of achieving the perfect body and is viewed with suspicion in face of standards of beauty broadcast; the importance of a healthy body was observed as standards of beauty and good looks were closely linked to good physical condition and result from having a healthy body; the relationship between the standard of beauty and prejudice, as people who are not considered attractive, having small physical imperfections, are discriminated against and can be rejected or even excluded from society. The standard of perfect body propagated by media influences adolescents' self-image and, consequently, self-esteem and is considered an unattainable goal, corresponding to a standard of beauty described as artificial and unreal. However, it causes great suffering and discrimination against those who do not feel they are attractive, which can lead to health problems resulting from low self-esteem.

Senses of body image in adolescents in elementary school

Directory of Open Access Journals (Sweden)

Maria Lídia de Abreu Silva

2014-06-01

Full Text Available OBJECTIVE : To comprehend the perception of body image in adolescence. METHODS : A qualitative study was conducted with eight focus groups with 96 students of both sexes attending four public elementary school institutions in the city of Rio de Janeiro, Southeastern Brazil, in 2013. An interview guide with questions about the adolescents’ feelings in relation to: their bodies, standards of idealized beauty, practice of physical exercise and sociocultural influences on self-image. In the data analysis we sought to understand and interpret the meanings and contradictions of narratives, understanding the subjects’ context and reasons and the internal logic of the group. RESULTS : Three thematic categories were identified. The influence of media on body image showed the difficulty of achieving the perfect body and is viewed with suspicion in face of standards of beauty broadcast; the importance of a healthy body was observed as standards of beauty and good looks were closely linked to good physical condition and result from having a healthy body; the relationship between the standard of beauty and prejudice, as people who are not considered attractive, having small physical imperfections, are discriminated against and can be rejected or even excluded from society. CONCLUSIONS : The standard of perfect body propagated by media influences adolescents’ self-image and, consequently, self-esteem and is considered an unattainable goal, corresponding to a standard of beauty described as artificial and unreal. However, it causes great suffering and discrimination against those who do not feel they are attractive, which can lead to health problems resulting from low self-esteem.

A method for total body irradiation

International Nuclear Information System (INIS)

Yasukochi, Hiroshi; Higashi, Shizuka; Okuhata, Yoshitaka; Lee, Keiichi; Ishioka, Kuniaki; Murakami, Koji; Nagai, Jun; Kuniyasu, Yoshio

1988-01-01

In these two years, we have treated four infant patients of acute leukemia by Cobalt-60 total body irradiation and bone marrow transplantation. During total body irradiation, thermoluminescence dosimeters were attached to the skin of patients. For four patients, nine dosimetries were performed. Reliability of this method was examined by phantom experiment. Every irradiation for the patient per fraction was 2.4 Gy, that is, 60 cGy for each four positions, right decubitus A-P and PA directions and left decubitus A-P and PA directions under aseptic circumstances. Radiation dose was uniform by this technique for each patient, and average determined dose for surface of the patients was between 87 % and 106 % compared with the air dose of the center of aseptic space (wagon). As the result, we suggest that this method is suitable for the total body irradiation of acute leukemia of infant. (author)

The inhomogeneous Suslov problem

Energy Technology Data Exchange (ETDEWEB)

García-Naranjo, Luis C., E-mail: luis@mym.iimas.unam.mx [Departamento de Matemáticas y Mecánica, IIMAS-UNAM, Apdo Postal 20-726, Mexico City 01000 (Mexico); Maciejewski, Andrzej J., E-mail: andrzej.j.maciejewski@gmail.com [J. Kepler Institute of Astronomy, University of Zielona Góra, Licealna 9, 65-417 Zielona Góra (Poland); Marrero, Juan C., E-mail: jcmarrero@ull.edu.es [ULL-CSIC, Geometría Diferencial y Mecánica Geométrica, Departamento de Matemática Fundamental, Facultad de Matemáticas, Universidad de la Laguna, La Laguna, Tenerife, Canary Islands (Spain); Przybylska, Maria, E-mail: M.Przybylska@if.uz.zgora.pl [Institute of Physics, University of Zielona Góra, Licealna 9, 65-417 Zielona Góra (Poland)

2014-06-27

We consider the Suslov problem of nonholonomic rigid body motion with inhomogeneous constraints. We show that if the direction along which the Suslov constraint is enforced is perpendicular to a principal axis of inertia of the body, then the reduced equations are integrable and, in the generic case, possess a smooth invariant measure. Interestingly, in this generic case, the first integral that permits integration is transcendental and the density of the invariant measure depends on the angular velocities. We also study the Painlevé property of the solutions. - Highlights: • We consider the Suslov problem of nonholonomic rigid body motion with inhomogeneous constraints. • We study the problem in detail for a particular choice of the parameters that has a clear physical interpretation. • We show that the equations of motion possess an invariant measure whose density depends on the velocity variables. • We show that the reduced system is integrable due to the existence of a transcendental first integral. • We study the Painlevé property of the solutions.

Correlations between cyanobacterial density and bacterial transformation to the viable but nonculturable (VBNC) state in four freshwater water bodies.

Science.gov (United States)

Chen, Huirong; Shen, Ju; Pan, Gaoshan; Liu, Jing; Li, Jiancheng; Hu, Zhangli

2015-10-01

Nutrient concentrations, phytoplankton density and community composition, and the viable but nonculturable (VBNC) state of heterotrophic bacteria were investigated in three connected reservoirs and a small isolated lake in South China to study the relationship between biotic and abiotic factors and the VBNC state in bacteria. Nutrient concentrations in the reservoirs increased in the direction of water flow, whereas Wenshan Lake was more eutrophic. Cyanobacterial blooms occurred in all four water bodies, with differing seasonal trends and dominant species. In Xili and Tiegang Reservoirs, the VBNC ratio (percent of VBNC state bacteria over total viable bacteria) was high for most of the year and negatively correlated with cyanobacterial density. Laboratory co-culture experiments were performed with four heterotrophic bacterial species isolated from Wenshan Lake (Escherichia coli, Klebsiella peneumoniae, Bacillus megaterium and Bacillus cereus) and the dominant cyanobacterial species (Microcystis aeruginosa). For the first three bacterial species, the presence of M. aeruginosa induced the VBNC state and the VBNC ratio was positively correlated with M. aeruginosa density. However, B. cereus inhibited M. aeruginosa growth. These results demonstrate that cyanobacteria could potentially regulate the transformation to the VBNC state of waterborne bacteria, and suggest a role for bacteria in cyanobacterial bloom initiation and termination.

Comparison of Dolphins' Body and Brain Measurements with Four Other Groups of Cetaceans Reveals Great Diversity.

Science.gov (United States)

Ridgway, Sam H; Carlin, Kevin P; Van Alstyne, Kaitlin R; Hanson, Alicia C; Tarpley, Raymond J

2016-01-01

We compared mature dolphins with 4 other groupings of mature cetaceans. With a large data set, we found great brain diversity among 5 different taxonomic groupings. The dolphins in our data set ranged in body mass from about 40 to 6,750 kg and in brain mass from 0.4 to 9.3 kg. Dolphin body length ranged from 1.3 to 7.6 m. In our combined data set from the 4 other groups of cetaceans, body mass ranged from about 20 to 120,000 kg and brain mass from about 0.2 to 9.2 kg, while body length varied from 1.21 to 26.8 m. Not all cetaceans have large brains relative to their body size. A few dolphins near human body size have human-sized brains. On the other hand, the absolute brain mass of some other cetaceans is only one-sixth as large. We found that brain volume relative to body mass decreases from Delphinidae to a group of Phocoenidae and Monodontidae, to a group of other odontocetes, to Balaenopteroidea, and finally to Balaenidae. We also found the same general trend when we compared brain volume relative to body length, except that the Delphinidae and Phocoenidae-Monodontidae groups do not differ significantly. The Balaenidae have the smallest relative brain mass and the lowest cerebral cortex surface area. Brain parts also vary. Relative to body mass and to body length, dolphins also have the largest cerebellums. Cortex surface area is isometric with brain size when we exclude the Balaenidae. Our data show that the brains of Balaenidae are less convoluted than those of the other cetaceans measured. Large vascular networks inside the cranial vault may help to maintain brain temperature, and these nonbrain tissues increase in volume with body mass and with body length ranging from 8 to 65% of the endocranial volume. Because endocranial vascular networks and other adnexa, such as the tentorium cerebelli, vary so much in different species, brain size measures from endocasts of some extinct cetaceans may be overestimates. Our regression of body length on endocranial

Relativistic few body calculations

International Nuclear Information System (INIS)

Gross, F.

1988-01-01

A modern treatment of the nuclear few-body problem must take into account both the quark structure of baryons and mesons, which should be important at short range, and the relativistic exchange of mesons, which describes the long range, peripheral interactions. A way to model both of these aspects is described. The long range, peripheral interactions are calculated using the spectator model, a general approach in which the spectators to nucleon interactions are put on their mass-shell. Recent numerical results for a relativistic OBE model of the NN interaction, obtained by solving a relativistic equation with one-particle on mass-shell, will be presented and discussed. Two meson exchange models, one with only four mesons (π,σ,/rho/,ω) but with a 25% admixture of γ 5 coupling for the pion, and a second with six mesons (π,σ,/rho/,ω,δ,/eta/) but pure γ 5 γ/sup μ/ pion coupling, are shown to give very good quantitative fits to the NN scattering phase shifts below 400 MeV, and also a good description of the /rvec p/ 40 Ca elastic scattering observables. Applications of this model to electromagnetic interactions of the two body system, with emphasis on the determination of relativistic current operators consistent with the dynamics and the exact treatment of current conservation in the presence of phenomenological form factors, will be described. 18 refs., 8 figs

Mathematical Tasks without Words and Word Problems: Perceptions of Reluctant Problem Solvers

Science.gov (United States)

Holbert, Sydney Margaret

2013-01-01

This qualitative research study used a multiple, holistic case study approach (Yin, 2009) to explore the perceptions of reluctant problem solvers related to mathematical tasks without words and word problems. Participants were given a choice of working a mathematical task without words or a word problem during four problem-solving sessions. Data…

Many-body problem in one-dimension

International Nuclear Information System (INIS)

Emery, V.J.

1979-11-01

This work attempts to give a qualitative feeling for the more important physical ideas involved with the study of many-body systems in one dimension, and considers a particular strong-coupling model. This model provides an excellent description of the chains of mercury ions in Hg/sub 3-delta/AsF 6 ; some of the predictions of the theory can be checked by x-ray and neutron diffraction. Much of the physics of nearly one-dimensional materials is concerned with understanding the possible types of phase transition that may take place, and establishing the conditions in which one or another will be predominant. The most significant feature of purely one-dimensional systems is the dominant effect of fluctuations. The paper is organized as follows: introduction; qualitative aspects of one-dimensional systems (general survey, mathematical model, qualitative discussion of strong coupling - strong attractive U, strong repulsive U, large V); strong coupling between parallel spins (independent spin systems, coupling between opposite spins); mercury chains; electrons with arbitrary coupling; boson representations of operators; and classical Coulomb gas

The evolutionary origin of the vertebrate body plan: the problem of head segmentation.

Science.gov (United States)

Onai, Takayuki; Irie, Naoki; Kuratani, Shigeru

2014-01-01

The basic body plan of vertebrates, as typified by the complex head structure, evolved from the last common ancestor approximately 530 Mya. In this review, we present a brief overview of historical discussions to disentangle the various concepts and arguments regarding the evolutionary development of the vertebrate body plan. We then explain the historical transition of the arguments about the vertebrate body plan from merely epistemological comparative morphology to comparative embryology as a scientific treatment on this topic. Finally, we review the current progress of molecular evidence regarding the basic vertebrate body plan, focusing on the link between the basic vertebrate body plan and the evolutionarily conserved developmental stages (phylotypic stages).

The body fades away: investigating the effects of transparency of an embodied virtual body on pain threshold and body ownership

Science.gov (United States)

Martini, Matteo; Kilteni, Konstantina; Maselli, Antonella; Sanchez-Vives, Maria V.

2015-01-01

The feeling of “ownership” over an external dummy/virtual body (or body part) has been proven to have both physiological and behavioural consequences. For instance, the vision of an “embodied” dummy or virtual body can modulate pain perception. However, the impact of partial or total invisibility of the body on physiology and behaviour has been hardly explored since it presents obvious difficulties in the real world. In this study we explored how body transparency affects both body ownership and pain threshold. By means of virtual reality, we presented healthy participants with a virtual co-located body with four different levels of transparency, while participants were tested for pain threshold by increasing ramps of heat stimulation. We found that the strength of the body ownership illusion decreases when the body gets more transparent. Nevertheless, in the conditions where the body was semi-transparent, higher levels of ownership over a see-through body resulted in an increased pain sensitivity. Virtual body ownership can be used for the development of pain management interventions. However, we demonstrate that providing invisibility of the body does not increase pain threshold. Therefore, body transparency is not a good strategy to decrease pain in clinical contexts, yet this remains to be tested. PMID:26415748

Multiple representations and free-body diagrams: Do students benefit from using them?

Science.gov (United States)

Rosengrant, David R.

2007-12-01

Introductory physics students have difficulties understanding concepts and solving problems. When they solve problems, they use surface features of the problems to find an equation to calculate a numerical answer often not understanding the physics in the problem. How do we help students approach problem solving in an expert manner? A possible answer is to help them learn to represent knowledge in multiple ways and then use these different representations for conceptual understanding and problem solving. This solution follows from research in cognitive science and in physics education. However, there are no studies in physics that investigate whether students who learn to use multiple representations are in fact better problem solvers. This study focuses on one specific representation used in physics--a free body diagram. A free-body diagram is a graphical representation of forces exerted on an object of interest by other objects. I used the free-body diagram to investigate five main questions: (1) If students are in a course where they consistently use free body diagrams to construct and test concepts in mechanics, electricity and magnetism and to solve problems in class and in homework, will they draw free-body diagrams on their own when solving exam problems? (2) Are students who use free-body diagrams to solve problems more successful then those who do not? (3) Why do students draw free-body diagrams when solving problems? (4) Are students consistent in constructing diagrams for different concepts in physics and are they consistent in the quality of their diagrams? (5) What are possible relationships between features of a problem and how likely a student will draw a free body diagram to help them solve the problem? I utilized a mixed-methods approach to answer these questions. Questions 1, 2, 4 and 5 required a quantitative approach while question 3 required a qualitative approach, a case study. When I completed my study, I found that if students are in an

What Is the Problem in Problem-Based Learning in Higher Education Mathematics

Science.gov (United States)

Dahl, Bettina

2018-01-01

Problem and Project-Based Learning (PBL) emphasise collaborate work on problems relevant to society and emphases the relation between theory and practice. PBL fits engineering students as preparation for their future professions but what about mathematics? Mathematics is not just applied mathematics, but it is also a body of abstract knowledge…

Four bugs on a rectangle

KAUST Repository

Chapman, S. J.

2010-11-10

The idealized mathematical problem of four bugs in cyclic pursuit starting from a 2-by-1 rectangle is considered, and asymptotic formulas are derived to describe the motion. In contrast to the famous case of four bugs on a square, here the trajectories quickly freeze to essentially one dimension. After the first rotation about the centre point, the scale of the configuration has shrunk by a factor of 10427907250, and this number is then exponentiated four more times with each successive cycle. Relations to Knuth\\'s double-arrow notation and level-index arithmetic are discussed. This journal is © 2011 The Royal Society.

The Markov moment problem and extremal problems

CERN Document Server

Kreĭn, M G; Louvish, D

1977-01-01

In this book, an extensive circle of questions originating in the classical work of P. L. Chebyshev and A. A. Markov is considered from the more modern point of view. It is shown how results and methods of the generalized moment problem are interlaced with various questions of the geometry of convex bodies, algebra, and function theory. From this standpoint, the structure of convex and conical hulls of curves is studied in detail and isoperimetric inequalities for convex hulls are established; a theory of orthogonal and quasiorthogonal polynomials is constructed; problems on limiting values of integrals and on least deviating functions (in various metrics) are generalized and solved; problems in approximation theory and interpolation and extrapolation in various function classes (analytic, absolutely monotone, almost periodic, etc.) are solved, as well as certain problems in optimal control of linear objects.

Search for CP violation in singly Cabibbo suppressed four-body D decays

Energy Technology Data Exchange (ETDEWEB)

Martinelli, Maurizio [Univ. of Bari Aldo Moro (Italy)

2011-02-01

We search for CP violation in a sample of 4.7 x 10⁴ singly Cabibbo suppressed D⁰ → K⁺ K^- π⁺π^- decays and 1.8(2.6) x 10⁴ D_(s)⁺ → K_S⁰ K⁺ π⁺ π^- decays. CP violation is searched for in the difference between the T-odd asymmetries, obtained using triple product correlations, measured for D and _D decays. The measured CP violation parameters are A_T(D⁰) = (1.0 ± 5.1(stat) ± 4.4(syst)) x 10^-3, A_T(D⁺) = (-11.96 ± 10.04(stat) ± 4.81(syst)) x 10^-3 and A_T(D_s⁺) = (-13.57 ± 7.67(stat) ± 4.82(syst)) x 10^-3. This search for CP violation showed that the T-odd correlations are a powerful tool to measure the CP violating observable A_T. The relative simplicity of an analysis based on T-odd correlations and the high quality results that can be obtained, allow to consider this tool as fundamental to search for CP violation in four-body decays. Even if the CP violation has not been found, excluding any New Physics effect to the sensitivity of about 0.5%, it is still worth to search for CP violation in D decays. The high statistics that can be obtained at the LHC or by the proposed high luminosity B-factories, make this topic to be considered in high consideration by experiments such as LHCb, SuperB or SuperBelle. The results outlined in this thesis strongly suggest to include a similar analysis into the Physics program of these experiments.

Investigations of the structure and electromagnetic interactions of few-body systems

International Nuclear Information System (INIS)

Lehman, D.R.

1991-07-01

In order to make it easy for the reader to see the specific research carried out and the progress make, the following report of progress is done by topic. Each item has a format layout of Topic, Investigators, Objective, Significance, and Description of Progress, followed at the end by the relevant references. As is clear from the topics listed, the emphasis of the GWU theory group has been on the structure and electromagnetic interactions of few-body nuclei. Both low- and intermediate-energy electromagnetic disintegration of these nuclei is considered. When the excitation energy of the target nucleus is low, the aim has been carry out the continuum part of the theoretical work exactly, this is, by means of exact three- and four-body dynamics. When structure questions are the issue, exact calculations are always carried through, limited only by the underlying two-body or three-body interactions used as input. Implicit in our work is the question of how far one can go within the traditional nuclear physics framework, i.e., nucleons and mesons in a nonrelativistic setting. Our central goal is to carry through state-of-the-art few-body calculations that will serve as an unambiguous means of determining at what point standard nuclear physics requires quark degrees of freedom in order to understand the phenomena in question. So far, in the problems considered, there has been no evidence of the necessity to go beyond the traditional approach, though we always keep in mind that possibility. As our work is involved with questions in the intermediate-energy realm, moving from a nonrelativistic framework to a relativistic one is always a consideration. Currently, for the problems that have been pursued in this domain of energy, the issues concern far more the mechanisms of the reactions and structural questions than the need to move to relativistic dynamics

The mind body problem: the hermeneutics of African philosophy ...

African Journals Online (AJOL)

Philosophers of different ages, epochs and ideological orientations have engaged themselves in a heated debate on the issue of the mind- body interaction. Indeed, there are two different but interactive entities in man with different modes of action yet interacting in themost subtlemanner as to produce in aman , amind able ...

Electroweak Structure of Three- and Four-Body Nuclei

Energy Technology Data Exchange (ETDEWEB)

Marcucci, Laura Elisa [Old Dominion Univ., Norfolk, VA (United States)

2000-06-01

This work reports results for (i) the elastic electromagnetic form factors of the trin- of ucleons; (ii) the nuclear response functions of interest in ~ experiments, 3 He(~e; e 0 ) experiments, at VERSITY excitation energies below the deuteron breakup threshold; (iii) the astrophysical ark S-factor for proton weak capture on 3 He (the hep reaction). The initial and nal using state wave functions are calculated using the correlated hyperspherical harmonics onsisting method, from a realistic Hamiltonian consisting of the Argonne v 18 two-nucleon uclear and Urbana IX three-nucleon interactions. The nuclear electroweak charge and ts. current operators include one- and many-body components. The predicted mag- netic form factor of 3 H, charge form factors and static properties of both 3 H and ntal 3 He, are in satisfactory agreement with the experimental data. However, the po- sition of the zero in the magnetic form factor of 3 He is underpredicted by theory. disintegration The calculated nuclear response functions in 3 He electrodisintegration at thresh- er old are in good agreement with the experimental data, which have however rather s large errors. Finally, the astrophysical S-factor for the hep reaction is predicted ortant ' 4.5 larger than the value adopted in the standard-solar-model, with important consequences for the solar neutrino spectrum measured by the Super-Kamiokande collaboration.

Sedentary behaviour, physical activity and weight problems in adolescents in Wales.

Science.gov (United States)

Elgar, F J; Roberts, C; Moore, L; Tudor-Smith, C

2005-06-01

We studied the prevalence and stability of overweight and obesity in a cohort of adolescents, and the effects of sedentary behaviour and physical activity on changes in body mass. The study also examined the extent to which physical activity mediated the relationship between sedentary behaviour and body mass. Four-year cohort study. The study was part of the Health Behaviour of School-aged Children Study that took place in Wales between 1994 and 1998. Body height and weight measurements and self-report data on sedentary behaviour, physical activity and psychosocial adjustment were collected from 355 adolescents on two occasions 4 years apart. The mean age of the sample at baseline was 12.30 (SD=6.30) years. Weight conditions (underweight, overweight and obesity) and body mass were moderately stable over the interval. Regression analyses showed that sedentary behaviour at Time 1 predicted body mass at Time 2, while physical activity predicted a change in body mass over time. The influence of sedentary behaviour on body mass was not found to be mediated by physical activity. However, weight problems in Year 7 coincided with getting bullied, bullying others, and feeling left out of things. Obesity was also related to snacking and skipping breakfast. Sedentary behaviour and physical activity in early adolescence both influenced body mass in late adolescence. Results indicated that promoting healthy diets and physical activities may have long-term health benefits for young people.

Attitude and Configuration Control of Flexible Multi-Body Spacecraft

Science.gov (United States)

Cho, Sung-Ki; Cochran, John E., Jr.

2002-06-01

Multi-body spacecraft attitude and configuration control formulations based on the use of collaborative control theory are considered. The control formulations are based on two-player, nonzero-sum, differential game theory applied using a Nash strategy. It is desired that the control laws allow different components of the multi-body system to perform different tasks. For example, it may be desired that one body points toward a fixed star while another body in the system slews to track another satellite. Although similar to the linear quadratic regulator formulation, the collaborative control formulation contains a number of additional design parameters because the problem is formulated as two control problems coupled together. The use of the freedom of the partitioning of the total problem into two coupled control problems and the selection of the elements of the cross-coupling matrices are specific problems addressed in this paper. Examples are used to show that significant improvement in performance, as measured by realistic criteria, of collaborative control over conventional linear quadratic regulator control can be achieved by using proposed design guidelines.

Attitude and Configuration Control of Flexible Multi-Body Spacecraft

Directory of Open Access Journals (Sweden)

Sungki Cho

2002-06-01

Full Text Available Multi-body spacecraft attitude and configuration control formulations based on the use of collaborative control theory are considered. The control formulations are based on two-player, nonzero-sum, differential game theory applied using a Nash strategy. It is desired that the control laws allow different components of the multi-body system to perform different tasks. For example, it may be desired that one body points toward a fixed star while another body in the system slews to track another satellite. Although similar to the linear quadratic regulator formulation, the collaborative control formulation contains a number of additional design parameters because the problem is formulated as two control problems coupled together. The use of the freedom of the partitioning of the total problem into two coupled control problems and the selection of the elements of the cross-coupling matrices are specific problems addressed in this paper. Examples are used to show that significant improvement in performance, as measured by realistic criteria, of collaborative control over conventional linear quadratic regulator control can be achieved by using proposed design guidelines.

Four-nucleon system with Δ-isobar excitation

International Nuclear Information System (INIS)

Deltuva, A.; Fonseca, A.C.; Sauer, P.U.

2008-01-01

The four-nucleon bound state and scattering below three-body breakup threshold are described based on the realistic coupled-channel potential CD Bonn+Δ which allows the excitation of a single nucleon to a Δ isobar. The Coulomb repulsion between protons is included. In the four-nucleon system the two-baryon coupled-channel potential yields effective two-, three- and four-nucleon forces, mediated by the Δ isobar and consistent with each other and with the underlying two-nucleon force. The effect of the four-nucleon force on the studied observables is much smaller than the effect of the three-nucleon force. The inclusion of the Δ isobar is unable to resolve the existing discrepancies with the experimental data

Numerical determination of families of three-dimensional double-symmetric periodic orbits in the restricted three-body problem. Pt. 1

International Nuclear Information System (INIS)

Kazantzis, P.G.

1979-01-01

New families of three-dimensional double-symmetric periodic orbits are determined numerically in the Sun-Jupiter case of the restricted three-body problem. These families bifurcate from the 'vertical-critical' orbits (αsub(ν) = -1, csub(ν) = 0) of the 'basic' plane families i. g 1 g 2 h, a, m and I. Further the numerical procedure employed in the determination of these families has been described and interesting results have been pointed out. Also, computer plots of the orbits of these families have been shown in conical projections. (orig.)

Four Essential Dimensions of Workplace Learning

Science.gov (United States)

Hopwood, Nick

2014-01-01

Purpose: This conceptual paper aims to argue that times, spaces, bodies and things constitute four essential dimensions of workplace learning. It examines how practices relate or hang together, taking Gherardi's texture of practices or connectedness in action as the foundation for making visible essential but often overlooked dimensions of…

Head Injury-A Neglected Public Health Problem: A Four-Month ...

African Journals Online (AJOL)

Background: Trauma, especially head trauma, is an expanding major public health problem and the leading cause of death of the young and productive part of the world's population. Research is mainly done in high-income countries where only a small proportion of the worldwide fatalities occur. The intention of this study ...

Macrodystrophia lipomatosa: four case reports

Directory of Open Access Journals (Sweden)

Ahmad Ibne

2010-10-01

Full Text Available Abstract Aim Macrodystrophia lipomatosa is a rare cause of gigantism of limb which can be confused with other common causes like congenital lymphedema. It presents usually with loss of function and cosmetic problems. Four cases are described with emphasis on clinical presentation, differential diagnoses, imaging and treatment options. Methods & Results Four patients of macrodystrophia lipomatosa were thoroughly examined and subjected to investigations. Conclusion Besides diligent clinical examination, imaging and histopathology are crucial in clinching the diagnosis.

Macrodystrophia lipomatosa: four case reports

Science.gov (United States)

2010-01-01

Aim Macrodystrophia lipomatosa is a rare cause of gigantism of limb which can be confused with other common causes like congenital lymphedema. It presents usually with loss of function and cosmetic problems. Four cases are described with emphasis on clinical presentation, differential diagnoses, imaging and treatment options. Methods & Results Four patients of macrodystrophia lipomatosa were thoroughly examined and subjected to investigations. Conclusion Besides diligent clinical examination, imaging and histopathology are crucial in clinching the diagnosis. PMID:20969776

Foreign Body Retrieval

Medline Plus

Full Text Available ... small toys or pieces of toys and fish bones. Swallowing of magnets can cause significant problems including ... like toothpicks. Small esophageal foreign bodies like fish bones also may be difficult to visualize. Additional evaluation ...

Foreign Body Retrieval

Medline Plus

Full Text Available ... include coins, buttons, pins, nails, glass pieces, toothpicks, batteries, small toys or pieces of toys and fish ... foreign body ingestions. Sometimes problems occur when button batteries are swallowed as mercury within the batteries can ...

Word Problem Wizardry.

Science.gov (United States)

Cassidy, Jack

1991-01-01

Presents suggestions for teaching math word problems to elementary students. The strategies take into consideration differences between reading in math and reading in other areas. A problem-prediction game and four self-checking activities are included along with a magic password challenge. (SM)

Problem solving stages in the five square problem.

Science.gov (United States)

Fedor, Anna; Szathmáry, Eörs; Öllinger, Michael

2015-01-01

According to the restructuring hypothesis, insight problem solving typically progresses through consecutive stages of search, impasse, insight, and search again for someone, who solves the task. The order of these stages was determined through self-reports of problem solvers and has never been verified behaviorally. We asked whether individual analysis of problem solving attempts of participants revealed the same order of problem solving stages as defined by the theory and whether their subjective feelings corresponded to the problem solving stages they were in. Our participants tried to solve the Five-Square problem in an online task, while we recorded the time and trajectory of their stick movements. After the task they were asked about their feelings related to insight and some of them also had the possibility of reporting impasse while working on the task. We found that the majority of participants did not follow the classic four-stage model of insight, but had more complex sequences of problem solving stages, with search and impasse recurring several times. This means that the classic four-stage model is not sufficient to describe variability on the individual level. We revised the classic model and we provide a new model that can generate all sequences found. Solvers reported insight more often than non-solvers and non-solvers reported impasse more often than solvers, as expected; but participants did not report impasse more often during behaviorally defined impasse stages than during other stages. This shows that impasse reports might be unreliable indicators of impasse. Our study highlights the importance of individual analysis of problem solving behavior to verify insight theory.

Problem solving stages in the five square problem

Directory of Open Access Journals (Sweden)

Anna eFedor

2015-08-01

Full Text Available According to the restructuring hypothesis, insight problem solving typically progresses through consecutive stages of search, impasse, insight and search again for someone, who solves the task. The order of these stages was determined through self-reports of problem solvers and has never been verified behaviourally. We asked whether individual analysis of problem solving attempts of participants revealed the same order of problem solving stages as defined by the theory and whether their subjective feelings corresponded to the problem solving stages they were in. 101 participants tried to solve the Five-Square problem in an online task, while we recorded the time and trajectory of their stick movements. After the task they were asked about their feelings related to insight and 67 of them also had the possibility of reporting impasse while working on the task. We have found that 49% (19 out of 39 of the solvers and 13% (8 out of 62 of the non-solvers followed the classic four-stage model of insight. The rest of the participants had more complex sequences of problem solving stages, with search and impasse recurring several times. This means that the classic four-stage model must be extended to explain variability on the individual level. We provide a model that can generate all sequences found. Solvers reported insight more often than non-solvers and non-solvers reported impasse more often than solvers, as expected; but participants did not report impasse more often during behaviourally defined impasse stages than during other stages. This shows that impasse reports might be unreliable indicators of impasse. Our study highlights the importance of individual analysis of problem solving behaviour to verify insight theory.

Gene-wise association of variants in four lysosomal storage disorder genes in neuropathologically confirmed Lewy body disease.

Science.gov (United States)

Clark, Lorraine N; Chan, Robin; Cheng, Rong; Liu, Xinmin; Park, Naeun; Parmalee, Nancy; Kisselev, Sergey; Cortes, Etty; Torres, Paola A; Pastores, Gregory M; Vonsattel, Jean P; Alcalay, Roy; Marder, Karen; Honig, Lawrence L; Fahn, Stanley; Mayeux, Richard; Shelanski, Michael; Di Paolo, Gilbert; Lee, Joseph H

2015-01-01

Variants in GBA are associated with Lewy Body (LB) pathology. We investigated whether variants in other lysosomal storage disorder (LSD) genes also contribute to disease pathogenesis. We performed a genetic analysis of four LSD genes including GBA, HEXA, SMPD1, and MCOLN1 in 231 brain autopsies. Brain autopsies included neuropathologically defined LBD without Alzheimer Disease (AD) changes (n = 59), AD without significant LB pathology (n = 71), Alzheimer disease and lewy body variant (ADLBV) (n = 68), and control brains without LB or AD neuropathology (n = 33). Sequencing of HEXA, SMPD1, MCOLN1 and GBA followed by 'gene wise' genetic association analysis was performed. To determine the functional effect, a biochemical analysis of GBA in a subset of brains was also performed. GCase activity was measured in a subset of brain samples (n = 64) that included LBD brains, with or without GBA mutations, and control brains. A lipidomic analysis was also performed in brain autopsies (n = 67) which included LBD (n = 34), ADLBV (n = 3), AD (n = 4), PD (n = 9) and control brains (n = 17), comparing GBA mutation carriers to non-carriers. In a 'gene-wise' analysis, variants in GBA, SMPD1 and MCOLN1 were significantly associated with LB pathology (p range: 0.03-4.14 x10(-5)). Overall, the mean levels of GCase activity were significantly lower in GBA mutation carriers compared to non-carriers (plipid classes, ceramides and sphingolipids, was observed in LBD brains carrying GBA mutations compared to controls (p range: p<0.05-p<0.01). Our study indicates that variants in GBA, SMPD1 and MCOLN1 are associated with LB pathology. Biochemical data comparing GBA mutation carrier to non-carriers support these findings, which have important implications for biomarker development and therapeutic strategies.

Gene-wise association of variants in four lysosomal storage disorder genes in neuropathologically confirmed Lewy body disease.

Directory of Open Access Journals (Sweden)

Lorraine N Clark

Full Text Available Variants in GBA are associated with Lewy Body (LB pathology. We investigated whether variants in other lysosomal storage disorder (LSD genes also contribute to disease pathogenesis.We performed a genetic analysis of four LSD genes including GBA, HEXA, SMPD1, and MCOLN1 in 231 brain autopsies. Brain autopsies included neuropathologically defined LBD without Alzheimer Disease (AD changes (n = 59, AD without significant LB pathology (n = 71, Alzheimer disease and lewy body variant (ADLBV (n = 68, and control brains without LB or AD neuropathology (n = 33. Sequencing of HEXA, SMPD1, MCOLN1 and GBA followed by 'gene wise' genetic association analysis was performed. To determine the functional effect, a biochemical analysis of GBA in a subset of brains was also performed. GCase activity was measured in a subset of brain samples (n = 64 that included LBD brains, with or without GBA mutations, and control brains. A lipidomic analysis was also performed in brain autopsies (n = 67 which included LBD (n = 34, ADLBV (n = 3, AD (n = 4, PD (n = 9 and control brains (n = 17, comparing GBA mutation carriers to non-carriers.In a 'gene-wise' analysis, variants in GBA, SMPD1 and MCOLN1 were significantly associated with LB pathology (p range: 0.03-4.14 x10(-5. Overall, the mean levels of GCase activity were significantly lower in GBA mutation carriers compared to non-carriers (p<0.001. A significant increase and accumulation of several species for the lipid classes, ceramides and sphingolipids, was observed in LBD brains carrying GBA mutations compared to controls (p range: p<0.05-p<0.01.Our study indicates that variants in GBA, SMPD1 and MCOLN1 are associated with LB pathology. Biochemical data comparing GBA mutation carrier to non-carriers support these findings, which have important implications for biomarker development and therapeutic strategies.

Finite Element Analysis of a Four-Cylinder Four Stroke Gasoline Engine Crankshaft

Directory of Open Access Journals (Sweden)

Parman Setyamartana

2014-07-01

Full Text Available Stress analysis of a crankshaft using traditional method is complicated and needs modification by considering its stress concentration factors. To solve this problem, the crankshaft strength of a four-cylinder four stroke gasoline engine is modeled and analyzed using finite element method (FEM in this paper. For this purpose, the crankshaft is modeled using CATIA software in detail. Then, the model is imported in ANSYS. In the recent software, the model is meshed into a number of finite elements. After defining the boundary and loading conditions, the stresses occur in the crankshaft are analyzed in order to identify critical locations on it.

The body participating:

DEFF Research Database (Denmark)

Pallesen, Hanne; Lund, Lone Blak; Jensen, Marianne

2017-01-01

-based analyses. The results were theoretically stated and supported. Results: In an effort to achieve patient participation, the following four themes seemed to be significant: 1) consciously encountering the patient in the moment, 2) the employment of concepts surrounding the interaction between body...

Mechanics problems in undergraduate physics

CERN Document Server

Strelkov, S P

2013-01-01

Problems in Undergraduate Physics, Volume I: Mechanics focuses on solutions to problems in physics. The book first discusses the fundamental problems in physics. Topics include laws of conservation of momentum and energy; dynamics of a point particle in circular motion; dynamics of a rotating rigid body; hydrostatics and aerostatics; and acoustics. The text also offers information on solutions to problems in physics. Answers to problems in kinematics, statics, gravity, elastic deformations, vibrations, and hydrostatics and aerostatics are discussed. Solutions to problems related to the laws of

Evolution of the regions of the 3D particle motion in the regular polygon problem of (N+1) bodies with a quasi-homogeneous potential

Science.gov (United States)

Fakis, Demetrios; Kalvouridis, Tilemahos

2017-09-01

The regular polygon problem of (N+1) bodies deals with the dynamics of a small body, natural or artificial, in the force field of N big bodies, the ν=N-1 of which have equal masses and form an imaginary regular ν -gon, while the Nth body with a different mass is located at the center of mass of the system. In this work, instead of considering Newtonian potentials and forces, we assume that the big bodies create quasi-homogeneous potentials, in the sense that we insert to the inverse square Newtonian law of gravitation an inverse cube corrective term, aiming to approximate various phenomena due to their shape or to the radiation emitting from the primaries. Based on this new consideration, we apply a general methodology in order to investigate by means of the zero-velocity surfaces, the regions where 3D motions of the small body are allowed, their evolutions and parametric variations, their topological bifurcations, as well as the existing trapping domains of the particle. Here we note that this process is definitely a fundamental step of great importance in the study of many dynamical systems characterized by a Jacobian-type integral of motion in the long way of searching for solutions of any kind.

45 CFR 1607.4 - Functions of a governing body.

Science.gov (United States)

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Functions of a governing body. 1607.4 Section 1607... GOVERNING BODIES § 1607.4 Functions of a governing body. (a) A governing body shall have at least four... accordance with written policies adopted by the recipient's governing body. (b) In addition to other powers...

Two-port access versus four-port access laparoscopic ovarian cystectomy.

Science.gov (United States)

Choi, Won-Kyu; Kim, Jang-Kew; Yang, Jung-Bo; Ko, Young-Bok; Nam, Sang-Lyun; Lee, Ki-Hwan

2014-09-01

This study was conducted to compare the surgical outcomes between two-port access and four-port access laparoscopic ovarian cystectomy. Four hundred and eighty nine patients who had received two-port access laparoscopic ovarian cystectomy (n=175) and four-port access laparoscopic ovarian cystectomy (n=314) in Chungnam National University Hospital from January 2009 to August 2012 were analyzed retrospectively. The data were compared between the bilaterality of the cysts and cyst diameter of less than 6 cm and 6 cm or more. There were no significant differences in patient's age, parity, body weight, body mass index and history of previous surgery between the two-port and four-port access laparoscopy group. Bilaterality of ovarian cysts was more in fourport access laparoscopy group (13.7% vs. 32.5%, P=0.000). There were no significant differences in operation time, hemoglobin change, hospital stay, adhesiolysis, transfusion, and insertion of hemo-vac between the two-port and four-port access laparoscopy group for size matched compare. However additional analgesics were more in four-port access laparoscopy group for unilateral ovarian cystectomy. Two-port access laparoscopic surgery was feasible and safe for unilateral and bilateral ovarian cystectomy compare with four-port access laparoscopic surgery.

Dynamic Multi-Rigid-Body Systems with Concurrent Distributed Contacts: Theory and Examples

International Nuclear Information System (INIS)

TRINKLE, JEFFREY C.; TZITZOURIS, J.A.; PANG, J.S.

2001-01-01

Consider a system of rigid bodies with multiple concurrent contacts. The multi-rigid-body contact problem is to predict the accelerations of the bodies and the normal friction loads acting at the contacts. This paper presents theoretical results for the multi-rigid-body contact problem under the assumptions that one or more contacts occur over locally planar, finite regions and that friction forces are consistent with the maximum work inequality. Existence and uniqueness results are presented for this problem under mild assumptions on the system inputs. In addition, the performance of two different time-stepping methods for integrating the dynamics are compared on two simple multi-body systems

Body packing and intra-vaginal body pushing of cocaine: A case report.

Science.gov (United States)

Wankhade, Vishwajit Kishor; Chikhalkar, B G

2018-03-01

Drug trafficking is an international problem. The prevalence of drug trafficking and newer concealing methods has been ever increasing. Body packing is described as using the abdominal or pelvic cavity for concealing illegal drugs. Body pushers smuggle illicit drugs by inserting them into rectum or vagina. These cases are either presented to the emergency departments as Body Packer Syndrome or as asymptomatic cases for observation, detained for alleged possession of contraband substances. We report a unique case of an asymptomatic white female who was detained at Mumbai International Airport under suspicion and brought to hospital for observation. X ray and CT scan examination revealed 7 wrapped packets in gastrointestinal track and 1 large packet in vagina. A case of female body packer using multiple modalities of concealment especially in vagina is rare in India so it is becomes imperative to present this case in the light of body packing and body pushing of contraband substances. Copyright © 2017 Elsevier B.V. All rights reserved.

Body Image and Attachment Style Among University Students

DEFF Research Database (Denmark)

Bo, Inger Glavind

2018-01-01

The main focus of this study is to investigate how body image and attachment style among university students are related. We approach these different student types on a cross sectional dataset including 898 university students from Denmark, Germany, Portugal, Croatia and Czechoslovakia. Based...... on the combination of the Body Esteem Scale (BES) and the Attachment Style Scale (WASQ) we create four types: "double jeopardy students", "well-balanced students", "nurturing solitude students" and "social mirroring students". The "double jeopardy students" are students with low social attachment and a high dislike...... of their body. Based on this combination of body image and social attachment we investigate how these four student types are related to three different dimensions: parental characteristics, northern versus southern countries and different field of study....

Canonical three-body angular basis

International Nuclear Information System (INIS)

Matveenko, A.V.

2001-01-01

Three-body problems are basic for the quantum mechanics of molecular, atomic, or nuclear systems. We demonstrate that their variational solution for rotational states can be greatly simplified. A special choice of coordinates (hyperspherical) and of the kinematics (body-fixed coordinate frame) allows one to choose basis functions in a form that makes the angular coupling trivial. (author)

Tool-Body Assimilation Model Based on Body Babbling and Neurodynamical System

Directory of Open Access Journals (Sweden)

Kuniyuki Takahashi

2015-01-01

Full Text Available We propose the new method of tool use with a tool-body assimilation model based on body babbling and a neurodynamical system for robots to use tools. Almost all existing studies for robots to use tools require predetermined motions and tool features; the motion patterns are limited and the robots cannot use novel tools. Other studies fully search for all available parameters for novel tools, but this leads to massive amounts of calculations. To solve these problems, we took the following approach: we used a humanoid robot model to generate random motions based on human body babbling. These rich motion experiences were used to train recurrent and deep neural networks for modeling a body image. Tool features were self-organized in parametric bias, modulating the body image according to the tool in use. Finally, we designed a neural network for the robot to generate motion only from the target image. Experiments were conducted with multiple tools for manipulating a cylindrical target object. The results show that the tool-body assimilation model is capable of motion generation.

Equipment to determine the total gamma activity and/or the geometrical distribution of radiation sources in a body with four detectors in near-cruciform arrangement

International Nuclear Information System (INIS)

Morsy, S.M.; Pohlit, W.; Stahlhofen, W.; Werner, E.

1979-01-01

This appliance serves for detection of the spatial distribution of airborne radioactive substances or aerosols which incorporated or inhaled in the pulmonary-respiratory tract. In order to determine the activities irrespective of their positions in the investigated body cross-section, the collimator cases of the four detectors, two of them being situated over and two under the carrying apparatus for men, have rectangular cross-sections. The detectors themselves can be removed within the collimator cases realtive to the axis of symmetry. (DG) [de

The Hill's three-body problem: a new deduction of motion equations

International Nuclear Information System (INIS)

Fuente Marcos, C. de la.

1995-01-01

Although the Hill's problem has been considered traditionally as a particular case of the restricted problem, it is not but rather a different problem with the same degree of generality. In this paper it is presented a new derivation of the motion equations obtained originally by Hill in 1878 as well as a brief discussion about its possible applications. (Author) 13 refs

Body Language.

Science.gov (United States)

Pollard, David E.

1993-01-01

Discusses how the use of body language in Chinese fiction strikes most Westerners as unusual, if not strange. Considers that, although this may be the result of differences in gestures or different conventions in fiction, it is a problem for translators, who handle the differences by various strategies, e.g., omission or expansion. (NKA)

Rates of detection of developmental problems at the 18-month well-baby visit by family physicians' using four evidence-based screening tools compared to usual care: a randomized controlled trial.

Science.gov (United States)

Thomas, R E; Spragins, W; Mazloum, G; Cronkhite, M; Maru, G

2016-05-01

Early and regular developmental screening can improve children's development through early intervention but is insufficiently used. Most developmental problems are readily evident at the 18-month well-baby visit. This trial's purpose is to: (1) compare identification rates of developmental problems by GPs/family physicians using four evidence-based tools with non-evidence based screening, and (2) ascertain whether the four tools can be completed in 10-min pre-visit on a computer. We compared two approaches to early identification via random assignment of 54 families to either: 'usual care' (informal judgment including ad-hoc milestones, n = 25); or (2) 'Evidence-based' care (use of four validated, accurate screening tools, n = 29), including: the Parents' Evaluation of Developmental Status (PEDS), the PEDS-Developmental Milestones (PEDS-DM), the Modified Checklist for Autism in Toddlers (M-CHAT) and PHQ9 (maternal depression). In the 'usual care' group four (16%) and in the evidence-based tools group 18 (62%) were identified as having a possible developmental problem. In the evidence-based tools group three infants were to be recalled at 24 months for language checks (no specialist referrals made). In the 'usual care' group four problems were identified: one child was referred for speech therapy, two to return to check language at 24 months and a mother to discuss depression. All forms were completed on-line within 10 min. Despite higher early detection rates in the evidence-based care group, there were no differences in referral rates between evidence-based and usual-care groups. This suggests that clinicians: (1) override evidence-based screening results with informal judgment; and/or (2) need assistance understanding test results and making referrals. Possible solutions are improve the quality of information obtained from the screening process, improved training of physicians, improved support for individual practices and acceptance by the regional

Conjugate problems in convective heat transfer

CERN Document Server

Dorfman, Abram S

2009-01-01

The conjugate heat transfer (CHT) problem takes into account the thermal interaction between a body and fluid flowing over or through it, a key consideration in both mechanical and aerospace engineering. Presenting more than 100 solutions of non-isothermal and CHT problems, this title considers the approximate solutions of CHT problems.

Seymour Fisher contributions to research on body image

Directory of Open Access Journals (Sweden)

P.R.L. Ribeiro

2011-01-01

Full Text Available The aim of this work was to systematically review Seymour Fisher contributions to research on body image. A literature review of his work on body perception, distorted body image, body boundary, assigned meanings to specific body areas, and general body awareness was carried out on four of the books written by the author. Fisher correlated those variables with defense mechanisms, adaptation, and body anxiety. Moreover, he also considered the roles played by culture and personality on the complex phenomenon of body experience. This review intends to disseminate Seymour Fisher contributions among Brazilian researchers on body image.

Problem of diagnosis and extraction of a foreign body in orbit associated with pain

Directory of Open Access Journals (Sweden)

Jovanović Miloš

2002-01-01

Full Text Available The aim of this study was to present the troubles and significance of a proper diagnosis of a foreign body which caused a double perforation of the eyeball and was retained in the orbit. Another reason for this case report was the intensive pain associated with the existing foreign body in the orbit. A male, 54 years old, had a perforating wound of the eyeball caused by a metal foreign body, which stayed in the orbit close to the scierai wall. X-ray and echographic examinations of the orbit were not conclusive regarding the question whether this foreign body was situated within or outside the eyeball. Only CT imaging showed that foreign body produced a double perforation of the eyeball and was externally close to the sciera. Foreign body was extracted by tran-sconjunctival anterior orbitotomy through the inferior fornix, using the electromagnetic probe. Since the first day of injury and up to the eighth day, the patient had intensive deep orbital pain, which was alleviated only partially by analgetics. It could not be explained by secondary glaucoma because IOP was normal or by an inflammatory process, or in any other way. Only the extraction of foreign body from the orbit led to the complete relief of pain. We believe that the pain was caused by compression of foreign body to some of scierai sensory nerves. X-ray and echographic examinations of the orbit are not always a reliable proof in the proper evaluation whether foreign body is within or outside the eyeball in the orbit. Precise diagnosis can be made only by CT imaging. The pain in the orbit may be caused by compression of foreign body to sensory nerves.

Pengaruh Brand Personality Terhadap Minat Beli Produk Body Mist (Studi pada The Body Shop di Trans Studio Mall Bandung

Directory of Open Access Journals (Sweden)

Agnes Naibaho

2017-06-01

Full Text Available This research is influenced by the problems related to the brand personality on The Body Shop’s Body Mist product. Those problems based on the results of pre-survey showed that brand personality of The Body Shop’s Body Mist product that consists of sincerity, excitement, competence, sophistication and ruggedness has not yet been fully received good response from respondents. In addition, although The Body Shop’s Body Mist product received the title of Top Brand of the year 2015 - 2016, Top Brand Index value of The Body Shop’s Body Mist product fell in 2016. This shows that the power of the brand personality The Body Shop’s Body Mist product also decreased, because the brand personality is a form factor the first parameter to measure the value of the percentage of TBI, which is top of mind brand awareness. This study aims to determine the influence of the brand personality which consist of sincerity, excitement, competence, sophistication and ruggedness towards purchase intention. The results shows that the brand personality and purchase intention is in good category. The results of multiple regression analysis addressing sub variable competence, sophistication and ruggedness significantly influence the purchase intention, and the coefficient of determination shows that the brand personality variables significantly influence the purchase intention by 54,5%, and 45,5% are influenced by other variables outside of this research.

An Investigation of Secondary Teachers’ Understanding and Belief on Mathematical Problem Solving

Science.gov (United States)

Yuli Eko Siswono, Tatag; Wachidul Kohar, Ahmad; Kurniasari, Ika; Puji Astuti, Yuliani

2016-02-01

Weaknesses on problem solving of Indonesian students as reported by recent international surveys give rise to questions on how Indonesian teachers bring out idea of problem solving in mathematics lesson. An explorative study was undertaken to investigate how secondary teachers who teach mathematics at junior high school level understand and show belief toward mathematical problem solving. Participants were teachers from four cities in East Java province comprising 45 state teachers and 25 private teachers. Data was obtained through questionnaires and written test. The results of this study point out that the teachers understand pedagogical problem solving knowledge well as indicated by high score of observed teachers‘ responses showing understanding on problem solving as instruction as well as implementation of problem solving in teaching practice. However, they less understand on problem solving content knowledge such as problem solving strategies and meaning of problem itself. Regarding teacher's difficulties, teachers admitted to most frequently fail in (1) determining a precise mathematical model or strategies when carrying out problem solving steps which is supported by data of test result that revealed transformation error as the most frequently observed errors in teachers’ work and (2) choosing suitable real situation when designing context-based problem solving task. Meanwhile, analysis of teacher's beliefs on problem solving shows that teachers tend to view both mathematics and how students should learn mathematics as body static perspective, while they tend to believe to apply idea of problem solving as dynamic approach when teaching mathematics.

Convex bodies with many elliptic sections

OpenAIRE

Arelio, Isaac; Montejano, Luis

2014-01-01

{We show in this paper that two normal elliptic sections through every point of the boundary of a smooth convex body essentially characterize an ellipsoid and furthermore, that four different pairwise non-tangent elliptic sections through every point of the $C^2$-differentiable boundary of a convex body also essentially characterize an ellipsoid.

Body Image, Media, and Eating Disorders

Science.gov (United States)

Derenne, Jennifer L.; Beresin, Eugene V.

2006-01-01

Objective: Eating disorders, including obesity, are a major public health problem today. Throughout history, body image has been determined by various factors, including politics and media. Exposure to mass media (television, movies, magazines, Internet) is correlated with obesity and negative body image, which may lead to disordered eating. The…

Measurement of the Branching Ratios of D+ and D+s Hadronic Decays to Four-Body Final States Containing a KS

Science.gov (United States)

Link, J. M.; Reyes, M.; Yager, P. M.; Anjos, J. C.; Bediaga, I.; Göbel, C.; Magnin, J.; Massafferi, A.; de Miranda, J. M.; Pepe, I. M.; Dos Reis, A. C.; Simão, F. R.; Carrillo, S.; Casimiro, E.; Sánchez-Hernández, A.; Uribe, C.; Vázquez, F.; Cinquini, L.; Cumalat, J. P.; O'Reilly, B.; Ramirez, J. E.; Vaandering, E. W.; Butler, J. N.; Cheung, H. W.; Gaines, I.; Garbincius, P. H.; Garren, L. A.; Gottschalk, E.; Kasper, P. H.; Kreymer, A. E.; Kutschke, R.; Bianco, S.; Fabbri, F. L.; Sarwar, S.; Zallo, A.; Cawlfield, C.; Kim, D. Y.; Rahimi, A.; Wiss, J.; Gardner, R.; Chung, Y. S.; Kang, J. S.; Ko, B. R.; Kwak, J. W.; Lee, K. B.; Park, H.; Alimonti, G.; Boschini, M.; Caccianiga, B.; D'Angelo, P.; Dicorato, M.; Dini, P.; Giammarchi, M.; Inzani, P.; Leveraro, F.; Malvezzi, S.; Menasce, D.; Mezzadri, M.; Milazzo, L.; Moroni, L.; Pedrini, D.; Pontoglio, C.; Prelz, F.; Rovere, M.; Sala, A.; Sala, S.; Davenport, T. F.; Agostino, L.; Arena, V.; Boca, G.; Bonomi, G.; Gianini, G.; Liguori, G.; Merlo, M.; Pantea, D.; Ratti, S. P.; Riccardi, C.; Segoni, I.; Viola, L.; Vitulo, P.; Hernandez, H.; Lopez, A. M.; Mendez, H.; Mendez, L.; Mirles, A.; Montiel, E.; Olaya, D.; Paris, A.; Quinones, J.; Rivera, C.; Xiong, W.; Zhang, Y.; Wilson, J. R.; Cho, K.; Handler, T.; Engh, D.; Hosack, M.; Johns, W. E.; Nehring, M.; Sheldon, P. D.; Stenson, K.; Webster, M.; Sheaff, M.

2001-10-01

We have studied hadronic four-body decays of D+ and D+s mesons with a KS in the final state using data recorded during the 1996-1997 fixed-target run of the Fermilab high energy photoproduction experiment FOCUS. We report a new branching ratio measurement of Γ(D+-->KSK- π+π+)/Γ(D+-->KSπ+π+π-) = 0.0768+/-0.0041+/-0.0032. We make the first observation of three new decay modes with branching ratios Γ(D+-->KSK+π+π- )/Γ(D+-->KSπ+π+π-) = 0.0562+/-0.0039+/-0.0040, Γ(D+-->KSK+K- π+)/Γ(D+-->KSπ+π+π-) = 0.0077+/-0.0015+/-0.0009, and Γ(D+s-->KSK+π+π- )/Γ(D+s-->KSK- π+π+) = 0.586+/-0.052+/-0.043, where in each case the first error is statistical and the second error is systematic.

Taking into account the Coulomb effects in the four-body model in reactions of simultaneous two-neutron transfer induced by heavy ions

International Nuclear Information System (INIS)

Kayumov, S.S.; Mukhamedzhanov, A.M.; Yarmukhamedov, R.

1988-01-01

In the four-body model for partial amplitudes of two-neutron transfer induced by heavy ions we derive in the approximation of the mechanism of simultaneous transfer the expression for the senior term for l→∞ taking into account the Coulomb effects. The senior singular term of the amplitude at z = zeta is singled out explicitly (z = cos θ, θ is the scattering angle in the c.m.s. and zeta is the singularity closest to the physical region which corresponds to the mechanism of simultaneous transfer). We calculate differential cross sections for the transfer of two neutrons between heavy ions and estimate the accuracy of taking into account the Coulomb effects in the traditional method of distorted waves

A new separable expansion for the two-body problem

International Nuclear Information System (INIS)

Haberzettl, H.

1988-07-01

We derive a new separable expansion of the two-body T matrix which represents the T matrix as a series of diagonal separable terms. The representation is exact half-on-shell at all energies even when truncated to one single term; moreover, the truncated expansion satisfies the full off-shell unitarity relation. The approach does not take recourse to some complete set of functions but rather uses properties of the Lippmann-Schwinger equation itself to arrive at the expansion. It is based on the W-matrix representation of the two-body T matrix introduced by Bartnik, Haberzettl, and Sandhas. That representation provides a splitting of the T matrix in one single separable term which contains all bound state poles and scatttering cuts and in a nonsingular, real remainder which vanishes half-on-shell. The method presented here yields a separable expansion of this remainder in which all its properties are preserved term by term. Any given n-term approximation can easily be refined to an (n+1)-term expansion by simply adding a new term. At each stage the amount of additional numerical work is constant. The method is applicable to any kind of short range potential, local, nonlocal or energy dependent. (orig.)

Ketone bodies in epilepsy.

Science.gov (United States)

McNally, Melanie A; Hartman, Adam L

2012-04-01

Seizures that are resistant to standard medications remain a major clinical problem. One underutilized option for patients with medication-resistant seizures is the high-fat, low-carbohydrate ketogenic diet. The diet received its name based on the observation that patients consuming this diet produce ketone bodies (e.g., acetoacetate, β-hydroxybutyrate, and acetone). Although the exact mechanisms of the diet are unknown, ketone bodies have been hypothesized to contribute to the anticonvulsant and antiepileptic effects. In this review, anticonvulsant properties of ketone bodies and the ketogenic diet are discussed (including GABAergic and glutamatergic effects). Because of the importance of ketone body metabolism in the early stages of life, the effects of ketone bodies on developing neurons in vitro also are discussed. Understanding how ketone bodies exert their effects will help optimize their use in treating epilepsy and other neurological disorders. © 2012 The Authors. Journal of Neurochemistry © 2012 International Society for Neurochemistry.

Core Problem: Does the CV Parent Body Magnetization require differentiation?

Science.gov (United States)

O'Brien, T.; Tarduno, J. A.; Smirnov, A. V.

2016-12-01

Evidence for the presence of past dynamos from magnetic studies of meteorites can provide key information on the nature and evolution of parent bodies. However, the suggestion of a past core dynamo for the CV parent body based on the study of the Allende meteorite has led to a paradox: a core dynamo requires differentiation, evidence for which is missing in the meteorite record. The key parameter used to distinguish core dynamo versus external field mechanisms is absolute field paleointensity, with high values (>>1 μT) favoring the former. Here we explore the fundamental requirements for absolute field intensity measurement in the Allende meteorite: single domain grains that are non-interacting. Magnetic hysteresis and directional data define strong magnetic interactions, negating a standard interpretation of paleointensity measurements in terms of absolute paleofield values. The Allende low field magnetic susceptibility is dominated by magnetite and FeNi grains, whereas the magnetic remanence is carried by an iron sulfide whose remanence-carrying capacity increases with laboratory cycling at constant field values, indicating reordering. The iron sulfide and FeNi grains are in close proximity, providing mineralogical context for interactions. We interpret the magnetization of Allende to record the intense early solar wind with metal-sulfide interactions amplifying the field, giving the false impression of a higher field value in some prior studies. An undifferentiated CV parent body is thus compatible with Allende's magnetization. Early solar wind magnetization should be the null hypothesis for evaluating the source of magnetization for chondrites and other meteorites.

Classical many-body problems amenable to exact treatments (solvable and/or integrable and/or linearizable...) in one-, two- and three-dimensional space

CERN Document Server

Calogero, Francesco

2001-01-01

This book focuses on exactly treatable classical (i.e. non-quantal non-relativistic) many-body problems, as described by Newton's equation of motion for mutually interacting point particles. Most of the material is based on the author's research and is published here for the first time in book form. One of the main novelties is the treatment of problems in two- and three-dimensional space. Many related techniques are presented, e.g. the theory of generalized Lagrangian-type interpolation in higher-dimensional spaces. This book is written for students as well as for researchers; it works out detailed examples before going on to treat more general cases. Many results are presented via exercises, with clear hints pointing to their solutions.

The impact of anal sphincter injury on perceived body image.

Science.gov (United States)

Iles, David; Khan, Rabia; Naidoo, Kristina; Kearney, Rohna; Myers, Jenny; Reid, Fiona

2017-05-01

Obstetric anal sphincter injury is common but the effect on body image is unreported. The aim of this study was to explore patient perceived changes in body image and other psychological aspects in women attending a perineal follow-up clinic. This retrospective study analysed women's responses to a self-reported questionnaire. Consecutive women with anal sphincter injury who attended a United Kingdom Maternity Hospital perineal follow-up clinic between January 1999 and January 2012 were identified and the records obtained and reviewed. Multivariate regression analyses were performed to examine variables influencing self-reported change in body image. Questionnaires and operation notes were analysed from 422 women who attended at a median of four months after delivery. 222 (53%) reported a change in body image with 80 (19%) reporting lower self-esteem and 75 (18%) a change in their personality due to the change in body image. 248 (59%) perceived an anatomical change due to the delivery. Factors associated with increased likelihood of reporting a change in body image were reporting a perceived change in anatomy due to the delivery, adjusted OR 6.11 (3.56-10.49), anal incontinence, OR 1.97 (1.16-3.36), and delivery by forceps, OR 2.59 (1.23-5.43). This is the first study to quantify body image changes in women after anal sphincter injury sustained in childbirth. These were found to be very common, affecting up to 50% of women. The study has several limitations but it does highlight the significant psychosocial problems of negative self-esteem and personality changes associated with a perceived change in body image that has not previously been reported. It also outlines the further research questions that need to be addressed. Copyright © 2017 Elsevier B.V. All rights reserved.

Body Weight, Self-Esteem, and Depression in Korean Female Adolescents.

Science.gov (United States)

Kim, Oksoo; Kim, Kyeha

2001-01-01

Examined whether body mass index (BMI) and perception of a body weight problem predict level of self esteem and depression in Korean female adolescents. Results showed that perception of a weight problem, but not BMI, contributed significantly to the prediction of level of self esteem and depression. (BF)

Reference Values and Age Differences in Body Composition of Community-Dwelling Older Japanese Men and Women: A Pooled Analysis of Four Cohort Studies.

Directory of Open Access Journals (Sweden)

Satoshi Seino

Full Text Available To determine age- and sex-specific body composition reference values and investigate age differences in these parameters for community-dwelling older Japanese men and women, using direct segmental multi-frequency bioelectrical impedance analysis.We conducted a pooled analysis of data collected in four cohort studies between 2008 and 2012: Kusatsu Longitudinal Study, Hatoyama Cohort Study, Itabashi Cohort Study, and Kashiwa Cohort Study. The pooled analysis included cross-sectional data from 4478 nondisabled, community-dwelling adults aged 65-94 years (2145 men, 2333 women; mean age: 72.9 years in men and 72.6 years in women. Body weight, fat mass (FM, percentage FM, fat-free mass (FFM, and appendicular lean soft tissue mass were measured using the InBody 720 and 430 (Biospace Co. Ltd, Seoul, Korea. The values were then normalized by height in meters squared to determine body mass index (BMI, FM index (FMI, FFM index (FFMI, and skeletal muscle mass index (SMI.Simple means (standard deviation of BMI, percentage FM, FMI, FFMI, and SMI were 23.4 (2.9 kg/m(2, 24.9 (6.3%, 5.96 (2.09 kg/m(2, 17.4 (1.5 kg/m(2, and 7.29 (0.76 kg/m(2, respectively, in men and 22.7 (3.3 kg/m(2, 31.7 (7.1%, 7.40 (2.61 kg/m(2, 15.3 (1.2 kg/m(2, and 5.86 (0.67 kg/m(2, respectively, in women. We then calculated quartiles and quintiles for these indices after stratifying for sex and 5-year age group. FFMI and SMI decreased significantly with age in both sexes (P < 0.001 for trends, but FFMI remained constant among the women with only a 1% decrease up to age 84 years. Percentage FM increased significantly, with age (P < 0.001 in men and P = 0.045 in women for trends, but FMI was unchanged in both sexes (P = 0.147 in men and P = 0.176 in women for trends.The present data should be useful in the clinical evaluation of body composition of older Japanese and for international comparisons. The small age-related decrease in FFMI may be a noteworthy characteristic of body composition

Four contamination indexes for continental waters characterization. Formulation and application

International Nuclear Information System (INIS)

Ramirez, A; Restrepo, R; Vina, G

1997-01-01

In this paper four indices of contamination, which qualify different water aspects are presents. Such indices allow for an overall assessment of the environmental status of the water bodies. These indices have been derived from accumulative experiences in hydro biological monitoring in the Colombian Petroleum industry for six years. Multivariable statistics was used. The indices were developed based on legislation from several countries, in accordance with the concentration of the different parameters and water usages. This indices of contamination (ICO) are: ICOMI (mineralization), ICOMO (organics contamination), ICOSUS (suspended solids) and ICOTRO (trophic system). The indices are easy to estimate (mathematically and/or graphically) and allow the identification the type of environmental problem, existing as demonstrated with examples and the near to zero correlations found. Thanks to the minimum number of variables, the application of these indices also diminishes monitoring and evaluation costs. In view of the advantages above mentioned is worth considering integrating the indices in to the national legislation

Optimization of the variational basis in the three body problem

International Nuclear Information System (INIS)

Simenog, I.V.; Pushkash, O.M.; Bestuzheva, A.B.

1995-01-01

The procedure of variational oscillator basis optimization is proposed to the calculation the energy spectra of three body systems. The hierarchy of basis functions is derived and energies of ground and excited states for three gravitating particles is obtained with high accuracy. 12 refs

Effect of various nutrient combinations on growth and body ...

African Journals Online (AJOL)

A total of 80 Labeo rohita fingerlings (mean body weight, 14.7 ± 0.08 g and length, 11.0 ± 0.16 cm) were randomly distributed into four treatments with 20 replicates each, for 60 days, to determine the effect of different feed compositions on the growth and body composition of L. rohita. Four isoenergetic (17.05 ± 0.24 kJ g-1) ...

A CMOS four-quadrant analog current multiplier

NARCIS (Netherlands)

Wiegerink, Remco J.

1991-01-01

A CMOS four-quadrant analog current multiplier is described. The circuit is based on the square-law characteristic of an MOS transistor and is insensitive to temperature and process variations. The circuit is insensitive to the body effect so it is not necessary to place transistors in individual

Many body calculations in atomic physics

International Nuclear Information System (INIS)

Kelly, H.P.

1985-01-01

The use of the many-body perturbation theory for atomic calculations are reviewed. The major emphasis is on the use of the linked-cluster many-body perturbation theory derived by Brueckner and Goldstone. Applications of many-body theory to calculations of hyperfine structure are examined. Auger rates and parity violation are discussed. Photoionization is reviewed, and the authors show how many-body perturbation theory can be applied to problems ranging from structural properties such as correlation energies and hyperfine structure to dynamical properties such as transitions induced by weak neutral currents and photoionization cross sections

Quantization of the Linearized Kepler Problem

OpenAIRE

Guerrero, Julio; Perez, Jose Miguel

2003-01-01

The linearized Kepler problem is considered, as obtained from the Kustaanheimo-Stiefel (K-S)transformation, both for negative and positive energies. The symmetry group for the Kepler problem turns out to be SU(2,2). For negative energies, the Hamiltonian of Kepler problem can be realized as the sum of the energies of four harmonic oscillator with the same frequency, with a certain constrain. For positive energies, it can be realized as the sum of the energies of four repulsive oscillator with...

Mass spectra of four-quark states in the hidden charm sector

International Nuclear Information System (INIS)

Patel, Smruti; Shah, Manan; Vinodkumar, P.C.

2014-01-01

Masses of the low-lying four-quark states in the hidden charm sector (cq anti c anti q; q element of u,d) are calculated within the framework of a non-relativistic quark model. The four-body system is considered as two two-body systems such as diquark-antidiquark (Qq- anti Q anti q) and quark-antiquark-quark-antiquark (Q anti q- anti Qq) molecular-like four-quark states. Here, the Cornell-type potential has been used for describing the two-body interactions among Q-q, anti Q- anti q, Q- anti q, Qq- anti Q anti q and Q anti q- anti Qq, with appropriate string tensions. Our present analysis suggests the following exotic states: X(3823), Z c (3900), X(3915), Z c (4025), ψ (4040), Z 1 (4050) and X(4160) as Q anti q- anti Qq molecular-like four-quark states, while Z c (3885), X(3940) and Y(4140) as the diquark-antidiquark four-quark states. We have been able to assign the J PC values for many of the recently observed exotic states according to their structure. Apart from this, we have identified the charged state Z(4430) recently confirmed by LHCb as the first radial excitation of Zc(3885) with G = + 1 and Y(4360) state as the first radial excitation of Y(4008) with G = - 1 and the state ψ(4415) as the first radial excitation of the ψ(4040) state. (orig.)

Efimov three-body states on top of a Fermi sea

International Nuclear Information System (INIS)

Nygaard, Nicolai Gayle; Zinner, Nikolaj Thomas

2014-01-01

The stabilization of Cooper pairs of bound electrons in the background of a Fermi sea is the origin of superconductivity and the paradigmatic example of the striking influence of many-body physics on few-body properties. In the quantum-mechanical three-body problem the famous Efimov effect yields unexpected scaling relations among a tower of universal states. These seemingly unrelated problems can now be studied in the same setup thanks to the success of ultracold atomic gas experiments. In light of the tremendous effect of a background Fermi sea on two-body properties, a natural question is whether a background can modify or even destroy the Efimov effect. Here we demonstrate how the generic problem of three interacting particles changes when one particle is embedded in a background Fermi sea, and show that Efimov scaling persists. It is found in a scaling that relates the three-body physics to the background density of fermionic particles

A simple coordinate space approach to three-body problems ...

Indian Academy of Sciences (India)

problems – Examples: Halo nucleus and double-λ hypernucleus ... Department of Physics, Jadavpur University, Kolkata 700 032, India. £Banaras Hindu ..... thanks the Department of Atomic Energy, India for financial support. References.

Identification of high school students' ability level of constructing free body diagrams to solve restricted and structured response items in force matter

Science.gov (United States)

Rahmaniar, Andinisa; Rusnayati, Heni; Sutiadi, Asep

2017-05-01

While solving physics problem particularly in force matter, it is needed to have the ability of constructing free body diagrams which can help students to analyse every force which acts on an object, the length of its vector and the naming of its force. Mix method was used to explain the result without any special treatment to participants. The participants were high school students in first grade totals 35 students. The purpose of this study is to identify students' ability level of constructing free body diagrams in solving restricted and structured response items. Considering of two types of test, every student would be classified into four levels ability of constructing free body diagrams which is every level has different characteristic and some students were interviewed while solving test in order to know how students solve the problem. The result showed students' ability of constructing free body diagrams on restricted response items about 34.86% included in no evidence of level, 24.11% inadequate level, 29.14% needs improvement level and 4.0% adequate level. On structured response items is about 16.59% included no evidence of level, 23.99% inadequate level, 36% needs improvement level, and 13.71% adequate level. Researcher found that students who constructed free body diagrams first and constructed free body diagrams correctly were more successful in solving restricted and structured response items.

Investigating Adolescent Stress and Body Image

Science.gov (United States)

Murray, Kristen M.; Byrne, Don G.; Rieger, Elizabeth

2011-01-01

Adolescent stress is clearly implicated in the development of mental health problems. However, its role in dysfunctional body image, which rises markedly in adolescence, has not been investigated. The present study examined the link between stress and body image, as well as self-esteem and depressive symptoms, in 533 high school students in grades…

Small-World Optimization Algorithm and Its Application in a Sequencing Problem of Painted Body Storage in a Car Company

Directory of Open Access Journals (Sweden)

Tian Zhipeng

2015-01-01

Full Text Available In the car company, the painted body storage (PBS is set up between the paint shop and the assembly shop. It stores the vehicles in production and reorders the vehicles sequence. To improve production efficiency of assembly shop, a mathematical model is developed aiming at minimizing the consumption rate of options and the total overtime and idle time. As the PBS sequencing process contains upstream sequence inbound and downstream sequence outbound, this paper proposes an algorithm with two phases. In the first phase, the discrete small-world optimization algorithm (DSWOA is applied to schedule the inbound sequence by employing the short-range nodes and the long-range nodes in order to realize the global searching. In the second phase, the heuristic algorithm is applied to schedule the outbound sequencing. The proposed model and algorithm are applied in an automobile enterprise. The results indicate that the two-phase algorithm is suitable for the PBS sequencing problem and the DSWOA has a better searching performance than GA in this problem. The sensitivity of model parameters is analyzed as well.

Three-body approach to the nucleon-nucleus optical potential

International Nuclear Information System (INIS)

Tandy, P.C.; Redish, E.F.; Bolle, D.

1976-01-01

In the Watson single scattering theory of the optical potential it is customary to approximate the propagation by two-body Green functions in order to simplify calculations. The reaction mechanism being described, however, is decidedly three-body in character. The central difficulty in building three-body models for nucleon-nucleus elastic scattering is to find the proper way of imbedding the superposed three-body reaction mechanism in the many-body problem without introducing serious overcounting effects. One would also like an explicit description of the intermediate state processes responsible for absorption. In this paper a three-body approximation to the optical potential theory is presented which overcomes the overcounting problem and is capable of including the following effects: (1) the proper kinematics of the struck nucleon, (2) its binding potential, (3) the identity of target nucleons, and (4) realistic wave functions and spectroscopic factors. The three-body model for the optical potential can be extended using unitarity methods to yield a unified three-body-like model of elastic scattering, pickup, and single nucleon knockout. (Auth.)

Body image, media, and eating disorders.

Science.gov (United States)

Derenne, Jennifer L; Beresin, Eugene V

2006-01-01

Eating disorders, including obesity, are a major public health problem today. Throughout history, body image has been determined by various factors, including politics and media. Exposure to mass media (television, movies, magazines, Internet) is correlated with obesity and negative body image, which may lead to disordered eating. The authors attempt to explain the historical context of the problem and explore potential avenues for change. The authors review changes in ideal female body type throughout history, comment on current attitudes toward shape and weight in both men and women, and outline interventions aimed at increasing healthy habits and fostering self-esteem in youth. Throughout history, the ideal of beauty has been difficult to achieve and has been shaped by social context. Current mass media is ubiquitous and powerful, leading to increased body dissatisfaction among both men and women. Parents need to limit children's exposure to media, promote healthy eating and moderate physical activity, and encourage participation in activities that increase mastery and self-esteem. Funding for high-quality, visible advertising campaigns promoting healthy life styles may increase awareness.

Reconstruction phases in the planar three- and four-vortex problems

Science.gov (United States)

Hernández-Garduño, Antonio; Shashikanth, Banavara N.

2018-03-01

Pure reconstruction phases—geometric and dynamic—are computed in the N-point-vortex model in the plane, for the cases N=3 and N=4 . The phases are computed relative to a metric-orthogonal connection on appropriately defined principal fiber bundles. The metric is similar to the kinetic energy metric for point masses but with the masses replaced by vortex strengths. The geometric phases are shown to be proportional to areas enclosed by the closed orbit on the symmetry reduced spaces. More interestingly, simple formulae are obtained for the dynamic phases, analogous to Montgomery’s result for the free rigid body, which show them to be proportional to the time period of the symmetry reduced closed orbits. For the case N = 3 a non-zero total vortex strength is assumed. For the case N = 4 the vortex strengths are assumed equal.

The inverse problem of the magnetostatic nondestructive testing

International Nuclear Information System (INIS)

Pechenkov, A.N.; Shcherbinin, V.E.

2006-01-01

The inverse problem of magnetostatic nondestructive testing consists in the calculation of the shape and magnetic characteristics of a flaw in a uniform magnetized body with measurement of static magnetic field beyond the body. If the flaw does not contain any magnetic material, the inverse problem is reduced to identification of the shape and magnetic susceptibility of the substance. This case has been considered in the study [ru

Dynamics formulas and problems : engineering mechanics 3

CERN Document Server

Gross, Dietmar; Wriggers, Peter; Schröder, Jörg; Müller, Ralf

2017-01-01

This book contains the most important formulas and more than 190 completely solved problems from Kinetics and Hydrodynamics. It provides engineering students material to improve their skills and helps to gain experience in solving engineering problems. Particular emphasis is placed on finding the solution path and formulating the basic equations. Topics include: - Kinematics of a Point - Kinetics of a Point Mass- Dynamics of a System of Point Masses - Kinematics of Rigid Bodies - Kinetics of Rigid Bodies - Impact - Vibrations - Non-Inertial Reference Frames - Hydrodynamics .

diseases free body

OpenAIRE

thararose

2018-01-01

Diseases are very common now a days . It is our food habits itself that causes this diseases. Diseases can cause many health problems. goiter causes and symptoms It is very important to follow healthy food habits and to maintain good health. A healthy body is always a treasure to every person.

Energy Harvesting Based Body Area Networks for Smart Health.

Science.gov (United States)

Hao, Yixue; Peng, Limei; Lu, Huimin; Hassan, Mohammad Mehedi; Alamri, Atif

2017-07-10

Body area networks (BANs) are configured with a great number of ultra-low power consumption wearable devices, which constantly monitor physiological signals of the human body and thus realize intelligent monitoring. However, the collection and transfer of human body signals consume energy, and considering the comfort demand of wearable devices, both the size and the capacity of a wearable device's battery are limited. Thus, minimizing the energy consumption of wearable devices and optimizing the BAN energy efficiency is still a challenging problem. Therefore, in this paper, we propose an energy harvesting-based BAN for smart health and discuss an optimal resource allocation scheme to improve BAN energy efficiency. Specifically, firstly, considering energy harvesting in a BAN and the time limits of human body signal transfer, we formulate the energy efficiency optimization problem of time division for wireless energy transfer and wireless information transfer. Secondly, we convert the optimization problem into a convex optimization problem under a linear constraint and propose a closed-form solution to the problem. Finally, simulation results proved that when the size of data acquired by the wearable devices is small, the proportion of energy consumed by the circuit and signal acquisition of the wearable devices is big, and when the size of data acquired by the wearable devices is big, the energy consumed by the signal transfer of the wearable device is decisive.

Processes involved in solving mathematical problems

Science.gov (United States)

Shahrill, Masitah; Putri, Ratu Ilma Indra; Zulkardi, Prahmana, Rully Charitas Indra

2018-04-01

This study examines one of the instructional practices features utilized within the Year 8 mathematics lessons in Brunei Darussalam. The codes from the TIMSS 1999 Video Study were applied and strictly followed, and from the 183 mathematics problems recorded, there were 95 problems with a solution presented during the public segments of the video-recorded lesson sequences of the four sampled teachers. The analyses involved firstly, identifying the processes related to mathematical problem statements, and secondly, examining the different processes used in solving the mathematical problems for each problem publicly completed during the lessons. The findings revealed that for three of the teachers, their problem statements coded as `using procedures' ranged from 64% to 83%, while the remaining teacher had 40% of his problem statements coded as `making connections.' The processes used when solving the problems were mainly `using procedures', and none of the problems were coded as `giving results only'. Furthermore, all four teachers made use of making the relevant connections in solving the problems given to their respective students.

Many-body problems in high temperature superconductivity

International Nuclear Information System (INIS)

Yu Lu.

1991-10-01

In this brief review the basic experimental facts about high T c superconductors are outlined. The superconducting properties of these superconductors are not very different from those of the ordinary superconductors. However, their normal state properties cannot be described by the standard Fermi liquid (FL) theory. Our current understanding of the strongly correlated models is summarized. In one dimension these systems behave like a ''Luttinger liquid'', very much distinct from the FL. In spite of the enormous efforts made in two-dimensional studies, the question of FL vs non-FL behaviour is still open. The numerical results as well as various approximation schemes are discussed. Both the single hole problem in a quantum antiferromagnet and finite doping regime are considered. (author). 104 refs, 9 figs

The problem of the motion of bodies a historical view of the development of classical mechanics

CERN Document Server

Capecchi, Danilo

2014-01-01

This book focuses on the way in which the problem of the motion of bodies has been viewed and approached over the course of human history. It is not another traditional history of mechanics but rather aims to enable the reader to fully understand the deeper ideas that inspired men, first in attempting to understand the mechanisms of motion and then in formulating theories with predictive as well as explanatory value. Given this objective, certain parts of the history of mechanics are neglected, such as fluid mechanics, statics, and astronomy after Newton. On the other hand, due attention is paid, for example, to the history of thermodynamics, which has its own particular point of view on motion. Inspired in part by historical epistemology, the book examines the various views and theories of a given historical period (synchronic analysis) and then makes comparisons between different periods (diachronic analysis). In each period, one or two of the most meaningful contributions are selected for particular attent...

Is BodyThink an efficacious body image and self-esteem program? A controlled evaluation with adolescents.

Science.gov (United States)

Richardson, Shanel M; Paxton, Susan J; Thomson, Julie S

2009-03-01

This study aimed to evaluate the efficacy of BodyThink, a widely disseminated body image and self-esteem program. Participants were 277, grade 7 students from 4 secondary schools in Australia. The intervention group (62 girls, 85 boys) participated in BodyThink during four 50-min lessons, while the control group (65 girls, 65 boys) received their usual classes. All participants completed baseline, postintervention and 3-month follow-up questionnaires. For girls, the intervention group reported higher media literacy and lower internalization of the thin ideal compared to the control group. For boys, the intervention group reported higher media literacy and body satisfaction than the control group. Although some positive outcomes were observed, it would be valuable to find ways to enhance the impact of BodyThink, especially in light of its wide dissemination. Suggestions for improving BodyThink are presented.

Configuration space methods in the three-nucleon problem

International Nuclear Information System (INIS)

Friar, J.L.

1985-01-01

The assumptions underlying the formulation and solution of the Schroedinger equation for three nucleons in configuration space are reviewed. Those qualitative aspects of the two-nucleon problem which play an important role in the trinucleon are discussed. The geometrical aspects of the problem are developed, and the importance of the angular momentum barrier is demonstrated. The Faddeev-Noyes formulation of the Schroedinger equation is motivated, and the boundary conditions for various three-body problems is reviewed. The method of splines is shown to provide a particularly useful numerical modelling technique for solving the Faddeev-Noyes equation. The properties of explicit trinucleon solutions for various two-body force models are discussed, and the evidence for three-body forces is reviewed. The status of calculations of trinucleon observables is discussed, and conclusions are presented. 40 refs., 14 figs

Child behavioural problems and body size among 2-6 year old children predisposed to overweight. results from the "healthy start" study

DEFF Research Database (Denmark)

Olsen, Nanna J; Pedersen, Jeanett; Händel, Mina N

2013-01-01

OBJECTIVE: Psychological adversities among young children may be associated with childhood overweight and obesity. We examined if an increased level of child behavioural problems was associated with body size among a selected group of 2-6 year old children, who were all predisposed to develop...... and Difficulties Questionnaire (SDQ) was used to assess child stress by the SDQ Total Difficulties (SDQ-TD) score and the Prosocial Behavior (PSB) score. Height and weight were measured, and BMI z-scores were calculated. RESULTS: A direct, but non-significant linear trend was found between SDQ-TD score and BMI z......, and family stress level. CONCLUSION: The results suggested a threshold effect between SDQ-TD score and BMI z-score, where BMI z-score was associated with childhood behavioural problems only for those with the highest scores of SDQ-TD. No significant association between PSB score and BMI z-score was found....

High-energy gravitational scattering and the general relativistic two-body problem

Science.gov (United States)

Damour, Thibault

2018-02-01

A technique for translating the classical scattering function of two gravitationally interacting bodies into a corresponding (effective one-body) Hamiltonian description has been recently introduced [Phys. Rev. D 94, 104015 (2016), 10.1103/PhysRevD.94.104015]. Using this technique, we derive, for the first time, to second-order in Newton's constant (i.e. one classical loop) the Hamiltonian of two point masses having an arbitrary (possibly relativistic) relative velocity. The resulting (second post-Minkowskian) Hamiltonian is found to have a tame high-energy structure which we relate both to gravitational self-force studies of large mass-ratio binary systems, and to the ultra high-energy quantum scattering results of Amati, Ciafaloni and Veneziano. We derive several consequences of our second post-Minkowskian Hamiltonian: (i) the need to use special phase-space gauges to get a tame high-energy limit; and (ii) predictions about a (rest-mass independent) linear Regge trajectory behavior of high-angular-momenta, high-energy circular orbits. Ways of testing these predictions by dedicated numerical simulations are indicated. We finally indicate a way to connect our classical results to the quantum gravitational scattering amplitude of two particles, and we urge amplitude experts to use their novel techniques to compute the two-loop scattering amplitude of scalar masses, from which one could deduce the third post-Minkowskian effective one-body Hamiltonian.

Esophageal Foreign Bodies

Directory of Open Access Journals (Sweden)

Ufuk Cobanoglu

2014-04-01

Full Text Available Esophageal foreign body aspiration is a common event which can cause serious morbidity and mortality in the children and adult population. For that reason, early diagnosis and treatment are crucial for preventing these life threateining complications. Children most often ingest coins and toys whereas adults commonly tend to have problems with meat and bones. Esophageal foreign bodies are located at the cricopharyngeus muscle level in 70%, the thoracic esophagus in 15% and the gastroesophageal junction in the remaining 15%. Symptoms can vary according to the shape and structure of the ingested object, type of location, patient%u2019s age and complications caused by the foreign body. Delay in treatment, esophageal perforation and an underlying esophageal disease are poor prognostic factors. In treatment, observation, foley catheter, rigid or flexible esophagoscopy and removing the foreign body with a Magill forceps, pushing the foreign body into the stomach, giving intravenous glucagon and surgical treatment methods can be used. Rigid esophagoscopy is an effective and safe procedure for foreign body diagnosis and removal. Improved endoscopic experience and clinical management of thoracic surgeons led to reduced morbidity and mortality in recent years. Most of those emergencies of childhood are preventable. Family education is very important.

Body Image in Primary Schools: A pilot evaluation of a primary school intervention program designed by teachers to improve children's body satisfaction.

Science.gov (United States)

Halliwell, Emma; Yager, Zali; Paraskeva, Nicole; Diedrichs, Phillippa C; Smith, Hilary; White, Paul

2016-12-01

Body Image in the Primary School (Hutchinson & Calland, 2011) is a body image curriculum that is widely available but has not yet been evaluated. This study evaluates a set of 6 of the 49 available lessons from this curriculum. Seventy-four girls and 70 boys aged 9-10 were recruited from four primary schools in the UK. Schools were randomly allocated into the intervention condition, where students received 6hours of body image lessons, or to lessons as normal. Body esteem was significantly higher among girls in the intervention group, compared to the control group, immediately post intervention, and at 3-month follow-up. Moreover, girls with lowest levels of body esteem at baseline reported the largest gains. Internalization was significantly lower among boys in the control group compared to the intervention group at 3-month follow-up. The pattern of results among the control group raises interesting issues for intervention evaluation. Copyright © 2016. Published by Elsevier Ltd.

Creating prototypes for cooling urban water bodies

NARCIS (Netherlands)

Cortesoao, Joao; Klok, E.J.; Lenzholzer, Sanda; Jacobs, C.M.J.; Kluck, J.

2017-01-01

Abstract When addressing urban heat problems, climate- conscious urban design has been assuming that urban water bodies such as canals, ditches or ponds cool down their surroundings. Recent research shows that this is not necessarily the case and that urban water bodies may actually have a warming e

Cluster model in reaction theory

International Nuclear Information System (INIS)

Adhikari, S.K.

1979-01-01

A recent work by Rosenberg on cluster states in reaction theory is reexamined and generalized to include energies above the threshold for breakup into four composite fragments. The problem of elastic scattering between two interacting composite fragments is reduced to an equivalent two-particle problem with an effective potential to be determined by extremum principles. For energies above the threshold for breakup into three or four composite fragments effective few-particle potentials are introduced and the problem is reduced to effective three- and four-particle problems. The equivalent three-particle equation contains effective two- and three-particle potentials. The effective potential in the equivalent four-particle equation has two-, three-, and four-body connected parts and a piece which has two independent two-body connected parts. In the equivalent three-particle problem we show how to include the effect of a weak three-body potential perturbatively. In the equivalent four-body problem an approximate simple calculational scheme is given when one neglects the four-particle potential the effect of which is presumably very small

On Hydroelastic Body-Boundary Condition of Floating Structures

DEFF Research Database (Denmark)

Xia, Jinzhu

1996-01-01

A general linear body boundary condition of hydroelastic analysis of arbitrary shaped floating structures generalizes the classic kinematic rigid-body (Timman-Newman) boundary condition for seakeeping problems. The new boundary condition is consistent with the existing theories under certain...

Lagrangian-Hamiltonian formalism for the gravitational two-body problem with spin and parametrized post-Newtonian parameters γ and β

International Nuclear Information System (INIS)

Barker, B.M.; O'Connell, R.F.

1976-01-01

We generalize the Lagrangian and Hamiltonian of our previous work on the gravitational two-body problem with spin by including the parametrized-post-Newtonian parameters γ and β. By this procedure we are able to obtain the precession of the orbit as well as the precession of the spin. Equations of motion corresponding to an arbitrary-spin supplementary condition are also given. Finally we show how the masses of the binary pulsar PSR 1913 + 16 and its companion are related to the orbit and spin precessions. Combining this with a result derivable from the second-order Doppler effect and the gravitational red-shift, we obtain a relation constraining the values that γ and β can take

Wisdom of the Body in Sport and Exercise Practices

Directory of Open Access Journals (Sweden)

Pisk Jernej

2017-10-01

Full Text Available Two alternative ancient views on medicine and health can be distinguished in western antiquity: first, that the knowledge of the doctor is sufficient, and second, that health is primarily a consequence of adapting one’s own life to the wisdom of the body. The body works according to its own laws, has its own “logic,” and speaks its own language. Therefore, listening to the body can be an important source of information for a healthy human life. The body is not merely an object for human manipulation and “the prison of the soul,” but a source of learning and knowledge. It seems that people rarely listen to their own bodies; however, the ancient wisdom of listening to the body is still present and cultivated in modern sports training. Good athletes and trainers are the ones who learn from the body and recognize its messages. In this article, we focus on four aspects of wisdom of the body, presented through four virtues: prudence, justice, fortitude, and temperance. The body teaches us temperance and justice; for example, when someone exaggerates too much, the body produces the feeling of pain. The body is a source of fortitude and persistence when rest and healing is needed. The body is a source of prudence or truth about oneself when we face the physical demands of sport. Therefore, through modern sports practices, the perennial wisdom of the body is still accessible to the modern man.

The effect of progressive resistance training on lean body mass in post-treatment cancer patients - A systematic review

DEFF Research Database (Denmark)

Lønbro, Simon

2014-01-01

Loss of lean body mass is a common problem in many post-treatment cancer patients and may negatively affect physical capacity in terms of maximal muscle strength and functional performance. The purpose of this study was to systematically review the scientific evidence on the effect of progressive...... resistance training on lean body mass in post-treatment cancer patients. A comprehensive literature search was conducted and ultimately 12 studies were included. Methodological quality of the included studies was evaluated using the PEDro scale and the effect of progressive resistance training was reported...... as the range of mean changes among RCTs and non-RCTs. Six RCTs and six non-RCTs were included in the study. In the RCTs the change in lean body mass in the progressive resistance training groups relative to control groups ranged from -0.4% to 3.9%, and in four of six trials the training effect...

Timing of post 131I ablation diagnostic whole body scan in differentiated thyroid cancer patients. Less than four months post ablation may be too early.

Science.gov (United States)

Winter, M; Winter, J; Heinzel, A; Behrendt, F F; Krohn, T; Mottaghy, F M; Verburg, F A

2015-01-01

to determine whether the first three months after 131I ablation is too early to perform radioiodine diagnostic whole body scintigraphy (dxWBS) in differentiated thyroid carcinoma patients. The files of 462 patients who were treated for DTC in our hospital were reviewed. All patients underwent surgical thyroidectomy. 146 patients had data available on a. a dxWBS which was performed less than four months (max 120 days) after 131I ablation with concurrent stimulated TSH stimulated thyroglobulin (Tg) measurement without further therapeutic measures between ablation and dxWBS and b. a second dxWBS or 131I therapy (rxWBS) within 1.5 years after ablation. A discordance between the initial and follow-up scan was found in 25/129 (19%) patients: of 54 patients with a positive initial dxWBS, scan results of a second dxWBS or rxWBS obtained with a suitable distance to the initial scan contradicted the initial one in 15 patients (27%). New lesions were discovered in 10/74 negative first dxWBS cases (14%). A discordance between the initial and follow-up stimulated Tg was found in 5/129 (4%) patients: 2/90 (2%) of patients with a negative stimulated Tg at initial dxWBS subsequently showed a positive results whereas 3/29 (10%) patients with an initially positive Tg showed a negative Tg level at the second procedure. Less than four months after 131I ablation is too early to perform radioiodine diagnostic whole body scintigraphy with concurrent TSH stimulated Tg measurement. The identification of the right, later, timepoint however requires further research.

Why do people buy dogs with potential welfare problems related to extreme conformation and inherited disease? A representative study of Danish owners of four small dog breeds

DEFF Research Database (Denmark)

Sandøe, Peter; Kondrup, Sara Vincentzen; Bennett, P.C.

2017-01-01

a nationwide Danish dog registry and invited to participate. Of these, 911 responded, giving a final sample of 846. There were clear differences between owners of the four breeds with respect to degree of planning prior to purchase, with owners of Chihuahuas exhibiting less. Motivations behind choice of dog...... and motivational factors behind acquisition of the dogs, and whether levels of experienced health and behavior problems were associated with the quality of the owner-dog relationship and the intention to re-procure a dog of the same breed. Owners of each of the four breeds (750/breed) were randomly drawn from...

Why do people buy dogs with potential welfare problems related to extreme conformation and inherited disease? A representative study of Danish owners of four small dog breeds.

Science.gov (United States)

Sandøe, P; Kondrup, S V; Bennett, P C; Forkman, B; Meyer, I; Proschowsky, H F; Serpell, J A; Lund, T B

2017-01-01

A number of dog breeds suffer from welfare problems due to extreme phenotypes and high levels of inherited diseases but the popularity of such breeds is not declining. Using a survey of owners of two popular breeds with extreme physical features (French Bulldog and Chihuahua), one with a high load of inherited diseases not directly related to conformation (Cavalier King Charles Spaniel), and one representing the same size range but without extreme conformation and with the same level of disease as the overall dog population (Cairn Terrier), we investigated this seeming paradox. We examined planning and motivational factors behind acquisition of the dogs, and whether levels of experienced health and behavior problems were associated with the quality of the owner-dog relationship and the intention to re-procure a dog of the same breed. Owners of each of the four breeds (750/breed) were randomly drawn from a nationwide Danish dog registry and invited to participate. Of these, 911 responded, giving a final sample of 846. There were clear differences between owners of the four breeds with respect to degree of planning prior to purchase, with owners of Chihuahuas exhibiting less. Motivations behind choice of dog were also different. Health and other breed attributes were more important to owners of Cairn Terriers, whereas the dog's personality was reported to be more important for owners of French Bulldogs and Cavalier King Charles Spaniels but less important for Chihuahua owners. Higher levels of health and behavior problems were positively associated with a closer owner-dog relationship for owners of Cavalier King Charles Spaniels and Chihuahuas but, for owners of French Bulldogs, high levels of problems were negatively associated with an intention to procure the same breed again. In light of these findings, it appears less paradoxical that people continue to buy dogs with welfare problems.

Investigation of the effects of human body stability on joint angles’ prediction

International Nuclear Information System (INIS)

Pasha Zanoosi, A. A.; Naderi, D.; Sadeghi-Mehr, M.; Feri, M.; Beheshtiha, A. Sh.; Fallahnejad, K.

2015-01-01

Loosing stability control in elderly or paralyzed has motivated researchers to study how a stability control system works and how to determine its state at every time instant. Studying the stability of a human body is not only an important problem from a scientific viewpoint, but also finally leads to new designs of prostheses and orthoses and rehabilitation methods. Computer modeling enables researchers to study and describe the reactions and propose a suitable and optimized motion pattern to strengthen the neuromuscular system and helps a human body maintain its stability. A perturbation as a tilting is exposed to an underfoot plate of a musculoskeletal model of the body to study the stability. The studied model of a human body included four links and three degrees of freedom with eight muscles in the sagittal plane. Lagrangian dynamics was used for deriving equations of motion and muscles were modeled using Hill’s model. Using experimental data of joint trajectories for a human body under tilting perturbation, forward dynamics has been applied to predict joint trajectories and muscle activation. This study investigated the effects of stability on predicting body joints’ motion. A new stability function for a human body, based on the zero moment point, has been employed in a forward dynamics procedure using a direct collocation method. A multi-objective optimization based on genetic algorithm has been proposed to employ stability as a robotic objective function along with muscle stresses as a biological objective function. The obtained results for joints’ motion were compared to experimental data. The results show that, for this type of perturbations, muscle stresses are in conflict with body stability. This means that more body stability requires more stresses in muscles and reverse. Results also show the effects of the stability objective function in better prediction of joint trajectories

Investigation of the effects of human body stability on joint angles’ prediction

Energy Technology Data Exchange (ETDEWEB)

Pasha Zanoosi, A. A., E-mail: aliakbar.pasha@yahoo.com, E-mail: aliakbar.pasha@qiau.ac.ir [Islamic Azad University, Faculty of Industrial & Mechanical Engineering, Qazvin Branch (Iran, Islamic Republic of); Naderi, D.; Sadeghi-Mehr, M.; Feri, M. [Bu Ali-Sina University, Mechanical Engineering Department, Faculty of Engineering (Iran, Islamic Republic of); Beheshtiha, A. Sh. [Leibniz Universität Hannover, Institute of Mechanics and Computational Mechanics (Germany); Fallahnejad, K. [Flinders University, Discipline of Mechanical Engineering, School of Computer Science, Engineering and Mathematics (Australia)

2015-10-15

Loosing stability control in elderly or paralyzed has motivated researchers to study how a stability control system works and how to determine its state at every time instant. Studying the stability of a human body is not only an important problem from a scientific viewpoint, but also finally leads to new designs of prostheses and orthoses and rehabilitation methods. Computer modeling enables researchers to study and describe the reactions and propose a suitable and optimized motion pattern to strengthen the neuromuscular system and helps a human body maintain its stability. A perturbation as a tilting is exposed to an underfoot plate of a musculoskeletal model of the body to study the stability. The studied model of a human body included four links and three degrees of freedom with eight muscles in the sagittal plane. Lagrangian dynamics was used for deriving equations of motion and muscles were modeled using Hill’s model. Using experimental data of joint trajectories for a human body under tilting perturbation, forward dynamics has been applied to predict joint trajectories and muscle activation. This study investigated the effects of stability on predicting body joints’ motion. A new stability function for a human body, based on the zero moment point, has been employed in a forward dynamics procedure using a direct collocation method. A multi-objective optimization based on genetic algorithm has been proposed to employ stability as a robotic objective function along with muscle stresses as a biological objective function. The obtained results for joints’ motion were compared to experimental data. The results show that, for this type of perturbations, muscle stresses are in conflict with body stability. This means that more body stability requires more stresses in muscles and reverse. Results also show the effects of the stability objective function in better prediction of joint trajectories.

Decomposing Large Inverse Problems with an Augmented Lagrangian Approach: Application to Joint Inversion of Body-Wave Travel Times and Surface-Wave Dispersion Measurements

Science.gov (United States)

Reiter, D. T.; Rodi, W. L.

2015-12-01

Constructing 3D Earth models through the joint inversion of large geophysical data sets presents numerous theoretical and practical challenges, especially when diverse types of data and model parameters are involved. Among the challenges are the computational complexity associated with large data and model vectors and the need to unify differing model parameterizations, forward modeling methods and regularization schemes within a common inversion framework. The challenges can be addressed in part by decomposing the inverse problem into smaller, simpler inverse problems that can be solved separately, providing one knows how to merge the separate inversion results into an optimal solution of the full problem. We have formulated an approach to the decomposition of large inverse problems based on the augmented Lagrangian technique from optimization theory. As commonly done, we define a solution to the full inverse problem as the Earth model minimizing an objective function motivated, for example, by a Bayesian inference formulation. Our decomposition approach recasts the minimization problem equivalently as the minimization of component objective functions, corresponding to specified data subsets, subject to the constraints that the minimizing models be equal. A standard optimization algorithm solves the resulting constrained minimization problems by alternating between the separate solution of the component problems and the updating of Lagrange multipliers that serve to steer the individual solution models toward a common model solving the full problem. We are applying our inversion method to the reconstruction of the·crust and upper-mantle seismic velocity structure across Eurasia.· Data for the inversion comprise a large set of P and S body-wave travel times·and fundamental and first-higher mode Rayleigh-wave group velocities.

Two-body interactions by tachyon exchange

International Nuclear Information System (INIS)

Maccarrone, R.; Recami, E.

1982-01-01

Due to its relevance for the possible applications to particle physics and for causality problems, is analyzed in this paper the kinematic of (classical) tachyon-exchange between two bodies A, B, for all possible relative velocities. In particular, the two cases u.-vector V-vector c 2 are carefully investigated, V are the body B and tachyon speeds relative to A, respectively

The structural and content aspects of abstracts versus bodies of full text journal articles are different.

Science.gov (United States)

Cohen, K Bretonnel; Johnson, Helen L; Verspoor, Karin; Roeder, Christophe; Hunter, Lawrence E

2010-09-29

An increase in work on the full text of journal articles and the growth of PubMedCentral have the opportunity to create a major paradigm shift in how biomedical text mining is done. However, until now there has been no comprehensive characterization of how the bodies of full text journal articles differ from the abstracts that until now have been the subject of most biomedical text mining research. We examined the structural and linguistic aspects of abstracts and bodies of full text articles, the performance of text mining tools on both, and the distribution of a variety of semantic classes of named entities between them. We found marked structural differences, with longer sentences in the article bodies and much heavier use of parenthesized material in the bodies than in the abstracts. We found content differences with respect to linguistic features. Three out of four of the linguistic features that we examined were statistically significantly differently distributed between the two genres. We also found content differences with respect to the distribution of semantic features. There were significantly different densities per thousand words for three out of four semantic classes, and clear differences in the extent to which they appeared in the two genres. With respect to the performance of text mining tools, we found that a mutation finder performed equally well in both genres, but that a wide variety of gene mention systems performed much worse on article bodies than they did on abstracts. POS tagging was also more accurate in abstracts than in article bodies. Aspects of structure and content differ markedly between article abstracts and article bodies. A number of these differences may pose problems as the text mining field moves more into the area of processing full-text articles. However, these differences also present a number of opportunities for the extraction of data types, particularly that found in parenthesized text, that is present in article bodies

Radiofrequency-assisted body piercing

Directory of Open Access Journals (Sweden)

Preethitha Babu

2017-01-01

Full Text Available The art of body piercing is ancient; however, nowadays it has evolved into a fashion statement. In the Indian subcontinent, ear and nose piercing hold religious and cultural significance in addition to being done for aesthetic reasons. Body piercing is routinely performed by railroading technique or by piercing guns; many modifications of the technique have emerged. Irrespective of the technique used, the main complications associated are intraoperative bleeding and postoperative infection. To overcome these problems, we describe a novel and simple technique of ear and nose piercing using the radio frequency cautery.

What can four solar neutrino experiments tell us about the magnetic moment solution to the solar neutrino problem?

International Nuclear Information System (INIS)

Pulido, J.

1993-01-01

The results reported by the four solar neutrino experiments (Homestake, Kamiokande, SAGE, Gallex) are analyzed from the point of view of the magnetic moment solution to the solar neutrino problem. The neutrino deficit reported by the gallium experiments (SAGE, Gallex) is apparently not as large as the one reported by Homestake and Kamiokande, a phenomenon suggesting a greater suppression in the large energy solar neutrino sector but also consistent with a uniform suppression for all neutrinos. Both uniform and nonuniform suppressions are examined for three different variants of the solar magnetic field and the possible parameter ranges for Δ 2 m 21 and μ ν are investigated. Massless neutrinos are not excluded and in all cases Δ 2 m 21 -5 eV 2 . The anticorrelation of the neutrino flux with sunspot activity is possible in any of the experiments but is in no way implied by a sizable magnetic moment and magnetic field

Control Problems of Hydrodynamic Type

National Research Council Canada - National Science Library

Krishnaprasad, P. S; Manikonda, Vikram

1998-01-01

It has been known for some time that the classical work of Kirchhoff, Love, and Birkhoff on rigid bodies in incompressible, irrotational flows provides effective models for treating control problems...

Noninvasive, three-dimensional full-field body sensor for surface deformation monitoring of human body in vivo

Science.gov (United States)

Chen, Zhenning; Shao, Xinxing; He, Xiaoyuan; Wu, Jialin; Xu, Xiangyang; Zhang, Jinlin

2017-09-01

Noninvasive, three-dimensional (3-D), full-field surface deformation measurements of the human body are important for biomedical investigations. We proposed a 3-D noninvasive, full-field body sensor based on stereo digital image correlation (stereo-DIC) for surface deformation monitoring of the human body in vivo. First, by applying an improved water-transfer printing (WTP) technique to transfer optimized speckle patterns onto the skin, the body sensor was conveniently and harmlessly fabricated directly onto the human body. Then, stereo-DIC was used to achieve 3-D noncontact and noninvasive surface deformation measurements. The accuracy and efficiency of the proposed body sensor were verified and discussed by considering different complexions. Moreover, the fabrication of speckle patterns on human skin, which has always been considered a challenging problem, was shown to be feasible, effective, and harmless as a result of the improved WTP technique. An application of the proposed stereo-DIC-based body sensor was demonstrated by measuring the pulse wave velocity of human carotid artery.

Loop corrections and other many-body effects in relativistic field theories

International Nuclear Information System (INIS)

Ainsworth, T.L.; Brown, G.E.; Prakash, M.; Weise, W.

1988-01-01

Incorporation of effective masses into negative energy states (nucleon loop corrections) gives rise to repulsive many-body forces, as has been known for some time. Rather than renormalizing away the three- and four-body terms, we introduce medium corrections into the effective σ-exchange, which roughly cancel the nucleon loop terms for densities ρ ≅ ρ nm , where ρ nm is nuclear matter density. Going to higher densities, the repulsive contributions tend to saturate whereas the attractive ones keep on growing in magnitude. The latter is achieved through use of a density-dependent effective mass for the σ-particle, m σ = m σ (ρ), such that m σ (ρ) decreases with increasing density. Such a behavior is seen e.g. in the Nambu-Jona-Lasinio model. It is argued that a smooth transition to chiral restoration implies a similar behavior. The resulting nuclear equation of state is, because of the self-consistency in the problem, immensely insensitive to changes in the mass or coupling constant of the σ-particle. (orig.)

Estimating a child's age from an image using whole body proportions.

Science.gov (United States)

Lucas, Teghan; Henneberg, Maciej

2017-09-01

The use and distribution of child pornography is an increasing problem. Forensic anthropologists are often asked to estimate a child's age from a photograph. Previous studies have attempted to estimate the age of children from photographs using ratios of the face. Here, we propose to include body measurement ratios into age estimates. A total of 1603 boys and 1833 girls aged 5-16 years were measured over a 10-year period. They are 'Cape Coloured' children from South Africa. Their age was regressed on ratios derived from anthropometric measurements of the head as well as the body. Multiple regression equations including four ratios for each sex (head height to shoulder and hip width, knee width, leg length and trunk length) have a standard error of 1.6-1.7 years. The error is of the same order as variation of differences between biological and chronological ages of the children. Thus, the error cannot be minimised any further as it is a direct reflection of a naturally occurring phenomenon.

Flyby Characterization of Lower-Degree Spherical Harmonics Around Small Bodies

Science.gov (United States)

Takahashi, Yu; Broschart, Stephen; Lantoine, Gregory

2014-01-01

Interest in studying small bodies has grown significantly in the last two decades, and there are a number of past, present, and future missions. These small body missions challenge navigators with significantly different kinds of problems than the planets and moons do. The small bodies' shape is often irregular and their gravitational field significantly weak, which make the designing of a stable orbit a complex dynamical problem. In the initial phase of spacecraft rendezvous with a small body, the determination of the gravitational parameter and lower-degree spherical harmonics are of crucial importance for safe navigation purposes. This motivates studying how well one can determine the total mass and lower-degree spherical harmonics in a relatively short time in the initial phase of the spacecraft rendezvous via flybys. A quick turnaround for the gravity data is of high value since it will facilitate the subsequent mission design of the main scientific observation campaign. We will present how one can approach the problem to determine a desirable flyby geometry for a general small body. We will work in the non-dimensional formulation since it will generalize our results across different size/mass bodies and the rotation rate for a specific combination of gravitational coefficients.

Body Satisfaction and Physical Appearance in Gender Dysphoria.