Sample records for four-body problem

  1. Particular Solutions in Four body problem with solar wind drag

    NASA Astrophysics Data System (ADS)

    Kumari, Reena; Singh Kushvah, Badam

    2012-07-01

    To study the motion of a group of celestial objects/bodies interacting with each other under gravitational attraction. We formulated a four body problem with solar wind drag of one radiating body, rotating about their common center of mass with central configuration. We suppose that the governing forces of the motion of four body problems are mutual gravitational attractions of bodies and drag force of radiating body. Firstly, we derive the equations of motion using new co-ordinates for the four body problem. Again, we find the integrals of motions under different cases regarding to the mass of the bodies. Then we find the zero velocity surfaces and particular solutions. Finally, we examined the effect of solar wind drag on the motion of the four body problem. Keywords: Four Body Problem; Particular Solutions; Radiation Force; Zero Velocity Surfaces.

  2. Periodic orbits in the restricted four-body problem with two equal masses

    NASA Astrophysics Data System (ADS)

    Burgos-García, Jaime; Delgado, Joaquín

    2013-06-01

    The restricted (equilateral) four-body problem consists of three bodies of masses m 1, m 2 and m 3 (called primaries) lying in a Lagrangian configuration of the three-body problem i.e., they remain fixed at the apices of an equilateral triangle in a rotating coordinate system. A massless fourth body moves under the Newtonian gravitation law due to the three primaries; as in the restricted three-body problem (R3BP), the fourth mass does not affect the motion of the three primaries. In this paper we explore symmetric periodic orbits of the restricted four-body problem (R4BP) for the case of two equal masses where they satisfy approximately the Routh's critical value. We will classify them in nine families of periodic orbits. We offer an exhaustive study of each family and the stability of each of them.

  3. Analytical stability criteria for the Caledonian Symmetric Four and Five Body Problems

    NASA Astrophysics Data System (ADS)

    Steves, Bonnie; Shoaib Afridi, Mohammad; Sweatman, Winston

    2017-06-01

    Analytical studies of the stability of three or more body gravitational systems are difficult because of the greater number of variables involved with the increasing number of bodies and the limitation of 10 integrals that exist in the gravitational n-body problem. Utilisation of symmetries or the neglecting of the masses of some of the bodies compared to others can simplify the dynamical problem and enable global analytical stability solutions to be derived. These symmetric and restricted few body systems with their analytical stability criterion can then provide useful information on the stability of the general few body system when near symmetry or the restricted situation. Even with symmetrical reductions, analytical stability derivations for four and five body problems are rare. In this paper, we develop an analytical stability criterion for the Caledonian Symmetric Five Body Problem (CS5BP) , a dynamically symmetrical planar problem with two pairs of equal masses and a fifth mass located at the centre of mass. Sundman’s inequality is applied to derive boundary surfaces to the allowed real motion of the system. This enables the derivation of a stability criterion valid for all time for the hierarchical stability of the CS5BP and its subset the Caledonian Symmetric Four Body Problem (CSFBP), where the central mass is taken to be equal to zero. We show that the hierarchical stability depends solely on the Szebehely constant C0, which is a function of the total energy H and angular momentum c. The critical value Ccrit at which the system becomes hierarchically stable for all time depends only on the two mass ratios of the symmetric five body system. We then explore the effect on the stability of the whole system of adding an increasing massive central body. It is shown both analytically and numerically that all CS5BPs and CSFBPs of different mass ratios are hierarchically stable if C0 > 0.0659 and C0 > 0.0465, respectively. The Caledonian Symmetric Four and

  4. Equilibria of the symmetric collinear restricted four-body problem with radiation pressure

    NASA Astrophysics Data System (ADS)

    Arribas, M.; Abad, A.; Elipe, A.; Palacios, M.

    2016-02-01

    In this paper, a restricted four-body problem with radiation pressure is considered. The three primaries are supposed in a collinear central configuration where both masses and both radiation forces of peripheral bodies are equal. After an adequate formulation, the problem is reduced to a tri-parametric one. A complete analysis of the position of equilibria and their stability in the space of parameters is performed.

  5. Fractal basins of attraction in the restricted four-body problem when the primaries are triaxial rigid bodies

    NASA Astrophysics Data System (ADS)

    Suraj, Md Sanam; Asique, Md Chand; Prasad, Umakant; Hassan, M. R.; Shalini, Kumari

    2017-11-01

    The planar equilateral restricted four-body problem, formulated on the basis of Lagrange's triangular solutions is used to determine the existence and locations of libration points and the Newton-Raphson basins of convergence associated with these libration points. We have supposed that all the three primaries situated on the vertices of an equilateral triangle are triaxial rigid bodies. This paper also deals with the effect of these triaxiality parameters on the regions of motion where the test particle is free to move. Further, the regions on the configuration plane filled by the basins of attraction are determined by using the multivariate version of the Newton-Raphson iterative system. The numerical study reveals that the triaxiality of the primaries is one of the most influential parameters in the four-body problem.

  6. Connection between three-body configuration and four-body configuration of the Sitnikov problem when one of the masses approaches zero: circular case

    NASA Astrophysics Data System (ADS)

    Shahbaz Ullah, M.; Hassan, M. R.

    2014-09-01

    In this manuscript we have established averaged equation of motion of the Sitnikov restricted three- body and four-body problem when all the primaries are point masses, by applying the Van der Pol transformation and averaging technique of J. Guckenheimer and P. Holmes (in Nonlinear Oscillations, Dynamical System Bifurcations of Vector Fields, Springer, Berlin, 1983). In addition to the resonance criterion at the 3/2 commensurability we have chosen ω=2 n/3, n=4, ω is the angular velocity of the coordinate system. Further we established the Series solution of the three-body and four-body problem in the sense of Sitnikov. Lastly the periodicities of the solutions have been examined by the Poincare section and four-body and three-body problem have been compared by different comparative graphs and surfaces.

  7. Investigation of Lyapunov stability of a central configuration in the restricted four-body problem

    NASA Astrophysics Data System (ADS)

    Bardin, B. S.; Esipov, P. A.

    2018-05-01

    The restricted planar four-body problem is considered. It is supposed that one of four bodies has infinitesimal mass and does not affect on motions of three other bodies. If two bodies have equal masses then there exists a central configuration such that three bodies are located in vertex of an equilateral triangle and the fourth body having infinitesimal mass is located in perpendicular bisector of the triangle. By using the method of normal forms and KAM theory stability of the above configuration is studied in the sense of Lyapunov.

  8. Stability of libration points in the restricted four-body problem with variable mass

    NASA Astrophysics Data System (ADS)

    Mittal, Amit; Aggarwal, Rajiv; Suraj, Md. Sanam; Bisht, Virender Singh

    2016-10-01

    We have investigated the stability of the Lagrangian solutions for the restricted four-body problem with variable mass. It has been assumed that the three primaries with masses m1, m2 and m3 form an equilateral triangle, wherein m2=m3. According to Jeans' law (Astronomy and Cosmogony, Cambridge University Press, Cambridge, 1928), the infinitesimal body varies its mass m with time. The space-time transformations of Meshcherskii (Studies on the Mechanics of Bodies of Variable Mass, GITTL, Moscow, 1949) are used by taking the values of the parameters q=1/2, k=0, n=1. The equations of motion of the infinitesimal body with variable mass have been determined. The equations of motion of the current problem differ from the ones of the restricted four-body problem with constant mass. There exist eight libration points, out of which two are collinear with the primary m1 and the rest are non-collinear for a fixed value of parameters γ (m {at time} t/m {at initial time}, 0<γ≤1 ), α (the proportionality constant in Jeans' law (Astronomy and Cosmogony, Cambridge University Press, Cambridge, 1928), 0≤α≤2.2) and μ=0.019 (the mass parameter). All the libration points are found to be unstable. The zero velocity surfaces (ZVS) are also drawn and regions of motion are discussed.

  9. Discrete restricted four-body problem: Existence of proof of equilibria and reproducibility of periodic orbits

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Minesaki, Yukitaka

    2015-01-01

    We propose the discrete-time restricted four-body problem (d-R4BP), which approximates the orbits of the restricted four-body problem (R4BP). The d-R4BP is given as a special case of the discrete-time chain regularization of the general N-body problem published in Minesaki. Moreover, we analytically prove that the d-R4BP yields the correct orbits corresponding to the elliptic relative equilibrium solutions of the R4BP when the three primaries form an equilateral triangle at any time. Such orbits include the orbit of a relative equilibrium solution already discovered by Baltagiannis and Papadakis. Until the proof in this work, there has been no discrete analog thatmore » preserves the orbits of elliptic relative equilibrium solutions in the R4BP. For a long time interval, the d-R4BP can precisely compute some stable periodic orbits in the Sun–Jupiter–Trojan asteroid–spacecraft system that cannot necessarily be reproduced by other generic integrators.« less

  10. Research in the Restricted Problems of Three and Four Bodies Final Scientific Report

    NASA Technical Reports Server (NTRS)

    Richards, Paul B.; Bernstein, Irwin S.; Chai, Winchung A.; Cronin, Jane; Ellis, Jordan; Fine, William E.; Kass, Sheldon; Musa, Samuel A.; Russell, Lawrence H.

    1968-01-01

    Seven studies have been conducted on research in the existence and nature of solutions of the restricted problems of three and four bodies. The details and results of five of these research investigations have already been published, and the latest two studies will be published shortly. A complete bibliography of publications is included in this report. This research has been primarily qualitative and has yielded new information on the behavior of trajectories near the libration points in the Earth-Moon-Sun and Sun-Jupiter-Saturn systems, and on the existence of periodic trajectories about the libration points of the circular and elliptical restricted four-body models. We have also implemented Birkhoff's normalization process for conservative and nonconservative Hamiltonian systems with equilibrium points. This makes available a technique for analyzing stability properties of certain nonlinear dynamical systems, and we have applied this technique to the circular and elliptical restricted three-body models. A related study was also conducted to determine the feasibility of using cislunar periodic trajectories for various space missions. Preliminary results suggest that this concept is attractive for space flight safety operations in cislunar space. Results of this research will be of interest to mathematicians, particularly those working in ordinary differential equations, dynamical systems and celestial mechanics; to astronomers; and to space guidance and mission analysts.

  11. On the photo-gravitational restricted four-body problem with variable mass

    NASA Astrophysics Data System (ADS)

    Mittal, Amit; Agarwal, Rajiv; Suraj, Md Sanam; Arora, Monika

    2018-05-01

    This paper deals with the photo-gravitational restricted four-body problem (PR4BP) with variable mass. Following the procedure given by Gascheau (C. R. 16:393-394, 1843) and Routh (Proc. Lond. Math. Soc. 6:86-97, 1875), the conditions of linear stability of Lagrange triangle solution in the PR4BP are determined. The three radiating primaries having masses m1, m2 and m3 in an equilateral triangle with m2=m3 will be stable as long as they satisfy the linear stability condition of the Lagrangian triangle solution. We have derived the equations of motion of the mentioned problem and observed that there exist eight libration points for a fixed value of parameters γ (m at time t/m at initial time, 0<γ≤1 ), α (the proportionality constant in Jeans' law (Astronomy and Cosmogony, Cambridge University Press, Cambridge, 1928), 0≤α≤2.2), the mass parameter μ=0.005 and radiation parameters qi, (0< qi≤1, i=1, 2, 3). All the libration points are non-collinear if q2≠ q3. It has been observed that the collinear and out-of-plane libration points also exist for q2=q3. In all the cases, each libration point is found to be unstable. Further, zero velocity curves (ZVCs) and Newton-Raphson basins of attraction are also discussed.

  12. Super central configurations of the n-body problem

    NASA Astrophysics Data System (ADS)

    Xie, Zhifu

    2010-04-01

    In this paper, we consider the inverse problem of central configurations of the n-body problem. For a given q =(q1,q2,…,qn)ε(Rd)n, let S(q ) be the admissible set of masses by S(q )={m =(m1,…,mn)∣miεR+, q is a central configurationfor m}. For a given m εS(q), let Sm(q) be the permutational admissible set about m =(m1,m2,…,mn) by Sm(q)={m'∣m'εS(q), m'≠m and m' is apermutation of m}. Here, q is called a super central configuration if there exists m such that Sm(q) is nonempty. For any q in the planar four-body problem, q is not a super central configuration as an immediate consequence of a theorem proved by MacMillan and Bartky ["Permanent configurations in the problem of four bodies," Trans. Am. Math. Soc. 34, 838 (1932)]. The main discovery in this paper is the existence of super central configurations in the collinear three-body problem. We proved that for any q in the collinear three-body problem and any m εS(q), Sm(q) has at most one element and the detailed classification of Sm(q) is provided.

  13. The exact solution of a four-body Coulomb problem

    NASA Astrophysics Data System (ADS)

    Ray, Hasi

    2018-03-01

    The elastic collision between two H-like atoms utilizing an ab initio static-exchange model (SEM) in the center of mass (CM) frame considering the system as a four-body Coulomb problem where all the Coulomb interaction terms in the direct and exchange channels are treated exactly, is studied thoroughly. A coupled-channel methodology in momentum space is used to solve Lippman-Schwinger equation following the integral approach. The new SEM code [Ray, Pramana 83, 907 (2014)] in which the Born-Oppenheimer (BO) scattering amplitude acts as input to derive the SEM amplitude using partial wave analysis, is utilized to study the s-, p-, d-wave elastic phase shifts and the corresponding partial cross sections. An augmented-Born approximation is used to include the contribution of higher partial waves more accurately to determine the total/integrated elastic cross sections. The effective range theory is used to determine the scattering lengths and effective ranges in the s-wave elastic scattering. The systems studied are Ps-Ps, Ps-Mu, Ps-H, Ps-D, Ps-T, Mu-Mu, Mu-H, Mu-D, Mu-T, H-H, H-D, H-T, D-D, D-T, T-T. The SEM includes the non-adiabatic short-range effects due to exchange. The MSEM code [Ray, Pramana 83, 907 (2014)] is used to study the effect of the long-range van der Waals interaction due to induced dipole polarizabilities of the atoms in H(1s)-H(1s) elastic collision. The dependence of scattering length on the reduced mass of the system and the dependence of scattering length on the strength of long-range van der Waals interaction that varies with the minimum interatomic distance are observed. Contribution to the Topical Issue "Low Energy Positron and Electron Interactions", edited by James Sullivan, Ron White, Michael Bromley, Ilya Fabrikant, and David Cassidy.

  14. Real-time control of optimal low-thrust transfer to the Sun-Earth L 1 halo orbit in the bicircular four-body problem

    NASA Astrophysics Data System (ADS)

    Salmani, Majid; Büskens, Christof

    2011-11-01

    In this article, after describing a procedure to construct trajectories for a spacecraft in the four-body model, a method to correct the trajectory violations is presented. To construct the trajectories, periodic orbits as the solutions of the three-body problem are used. On the other hand, the bicircular model based on the Sun-Earth rotating frame governs the dynamics of the spacecraft and other bodies. A periodic orbit around the first libration-point L1 is the destination of the mission which is one of the equilibrium points in the Sun-Earth/Moon three-body problem. In the way to reach such a far destination, there are a lot of disturbances such as solar radiation and winds that make the plans untrustworthy. However, the solar radiation pressure is considered in the system dynamics. To prevail over these difficulties, considering the whole transfer problem as an optimal control problem makes the designer to be able to correct the unavoidable violations from the pre-designed trajectory and strategies. The optimal control problem is solved by a direct method, transcribing it into a nonlinear programming problem. This transcription gives an unperturbed optimal trajectory and its sensitivities with respect perturbations. Modeling these perturbations as parameters embedded in a parametric optimal control problem, one can take advantage of the parametric sensitivity analysis of nonlinear programming problem to recalculate the optimal trajectory with a very smaller amount of computation costs. This is obtained by evaluating a first-order Taylor expansion of the perturbed solution in an iterative process which is aimed to achieve an admissible solution. At the end, the numerical results show the applicability of the presented method.

  15. Why the way we consider the body matters – Reflections on four bioethical perspectives on the human body

    PubMed Central

    Schicktanz, Silke

    2007-01-01

    Background Within the context of applied bioethical reasoning, various conceptions of the human body are focused upon by the author in relation to normative notions of autonomy. Results The author begins by descriptively exploring some main positions in bioethics from which the "body" is conceptualized. Such positions conflict: the body is that which is constitutive of the individual's experience and perception, or it is conceived of materially or mechanistically; or as a constructed locus, always historically and culturally transformed. The author goes on to suggest a methodological approach that dialectically considers embodiment from four different perspectives: as bodily self-determination, as respect for the bodily unavailability of the other, as care for bodily individuality; and lastly, as acknowledgement of bodily-constituted communities. These four perspectives encompass autonomy in two of its main interpretations: as the capability of a person to act independent of external forces, and as the moral ideal of pursuing individual wishes by means of role distance, self-limitation and universalization. Various bioethical cases are utilized to show how the four perspectives on the body can complement one another. Conclusion The way we consider the body matters. The author's dialectical method allows a premise-critical identification and exploration of bioethical problems concerning the body. The method is potentially applicable to other bioethical problems. PMID:18053201

  16. Four-body trajectory optimization

    NASA Technical Reports Server (NTRS)

    Pu, C. L.; Edelbaum, T. N.

    1973-01-01

    A collection of typical three-body trajectories from the L1 libration point on the sun-earth line to the earth is presented. These trajectories in the sun-earth system are grouped into four distinct families which differ in transfer time and delta V requirements. Curves showing the variations of delta V with respect to transfer time, and typical two and three-impulse primer vector histories, are included. The development of a four-body trajectory optimization program to compute fuel optimal trajectories between the earth and a point in the sun-earth-moon system are also discussed. Methods for generating fuel optimal two-impulse trajectories which originate at the earth or a point in space, and fuel optimal three-impulse trajectories between two points in space, are presented. A brief qualitative comparison of these methods is given. An example of a four-body two-impulse transfer from the Li libration point to the earth is included.

  17. The mind-body problem.

    PubMed

    Chambliss, Bryan

    2018-05-04

    The mind-body problem is the problem of explaining how the happenings of our mental lives are related to physical states, events and processes. Proposed solutions to the problem vary by whether and how they endorse physicalism, the claim that mental states are ultimately "nothing over and above" physical states, and by how they understand the interactions between mental and physical states. Physicalist solutions to the mind-body problem have been dominant in the last century, with the variety of physicalism endorsed (reductive or nonreductive) depending upon both the outcome of philosophical arguments and methodological developments in the cognitive and neural sciences. After outlining the dominant contemporary approach to the mind-body problem, I examine the prospects for a solution in light of developments in the cognitive sciences, especially the scientific study of consciousness. This article is categorized under: Philosophy > Consciousness Philosophy > Metaphysics Philosophy > Foundations of Cognitive Science. © 2018 Wiley Periodicals, Inc.

  18. Gravitational Many-Body Problem

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Makino, J.

    2008-04-29

    In this paper, we briefly review some aspects of the gravitational many-body problem, which is one of the oldest problems in the modern mathematical science. Then we review our GRAPE project to design computers specialized to this problem.

  19. Body ownership and the four-hand illusion.

    PubMed

    Chen, Wen-Yeo; Huang, Hsu-Chia; Lee, Yen-Tung; Liang, Caleb

    2018-02-01

    Recent studies of the rubber hand illusion (RHI) have shown that the sense of body ownership is constrained by several factors and yet is still very flexible. However, exactly how flexible is our sense of body ownership? In this study, we address this issue by investigating the following question: is it possible that one may have the illusory experience of owning four hands? Under visual manipulation, the participant adopted the experimenter's first-person perspective (1PP) as if it was his/her own. Sitting face to face, the participant saw four hands-the experimenter's two hands from the adopted 1PP together with the subject's own two hands from the adopted third-person perspective (3PP). We found that: (1) the four-hand illusion did not occur in the passive four-hand condition. (2) In the active four-hand condition, the participants tapped their index fingers, imitated by the experimenter. When tactile stimulations were not provided, the key illusion was not induced, either. (3) Strikingly, once all four hands began to act with the same pattern and received synchronous tactile stimulations at the same time, many participants felt as if they had two more hands. These results show that the sense of body ownership is much more flexible than most researchers have suggested.

  20. Convex central configurations for the n-body problem

    NASA Astrophysics Data System (ADS)

    Xia, Zhihong

    We give a simple proof of a classical result of MacMillan and Bartky (Trans. Amer. Math. Soc. 34 (1932) 838) which states that, for any four positive masses and any assigned order, there is a convex planar central configuration. Moreover, we show that the central configurations we find correspond to local minima of the potential function with fixed moment of inertia. This allows us to show that there are at least six local minimum central configurations for the planar four-body problem. We also show that for any assigned order of five masses, there is at least one convex spatial central configuration of local minimum type. Our method also applies to some other cases.

  1. Some new concepts in the n-body and 3-body problems

    NASA Astrophysics Data System (ADS)

    Kyrala, A.

    1982-06-01

    A new approach to the n-body problem in terms of an rms particle velocity and a harmonic mean particle separation has been constructed by using averaging procedures formulated in terms of a single parameter. A systematic classification of escape and collision processes by means of specific polynomials, which can be used somewhat like generating functions, is introduced. For n-body problems with non-null total angular momentum, an rms angular momentum is defined which together with a harmonic mean centroidal moment of inertia characterizes the rotational kinetic energy. Finally, a graphical construction for the equipotentials of the three-body problem is given and attention is drawn to the use of the apex, defined as the point of least average separation, in this problem. It is supposed that the n-bodies interact with one another via the Newtonian potential in an inertial system.

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

    PubMed

    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.

  3. When do star clusters become multiple star systems? II. Toward a half-life formalism with four bodies

    NASA Astrophysics Data System (ADS)

    Ibragimov, Timur; Leigh, Nathan W. C.; Ryu, Taeho; Panurach, Teresa; Perna, Rosalba

    2018-03-01

    We present a half-life formalism for describing the disruption of gravitationally-bound few-body systems, with a focus on binary-binary scattering. For negative total encounter energies, the four-body problem has three possible decay products in the point particle limit. For each decay product and a given set of initial conditions, we obtain directly from numerical scattering simulations the half-life for the distribution of disruption times. As in radioactive decay, the half-lives should provide a direct prediction for the relative fractions of each decay product. We test this prediction with simulated data and find good agreement with our hypothesis. We briefly discuss applications of this feature of the gravitational four-body problem to populations of black holes in globular clusters. This paper, the second in the series, builds on extending the remarkable similarity between gravitational chaos at the macroscopic scale and radioactive decay at the microscopic scale to larger-N systems.

  4. When do star clusters become multiple star systems? II. Towards a half-life formalism with four bodies

    NASA Astrophysics Data System (ADS)

    Ibragimov, Timur; Leigh, Nathan W. C.; Ryu, Taeho; Panurach, Teresa; Perna, Rosalba

    2018-07-01

    We present a half-life formalism for describing the disruption of gravitationally bound few-body systems, with a focus on binary-binary scattering. For negative total encounter energies, the four-body problem has three possible decay products in the point-particle limit. For each decay product and a given set of initial conditions, we obtain directly from numerical scattering simulations the half-life for the distribution of disruption times. As in radioactive decay, the half-lives should provide a direct prediction for the relative fractions of each decay product. We test this prediction with simulated data and find good agreement with our hypothesis. We briefly discuss applications of this feature of the gravitational four-body problem to populations of black holes in globular clusters. This paper, the second in the series, builds on extending the remarkable similarity between gravitational chaos at the macroscopic scale and radioactive decay at the microscopic scale to larger-N systems.

  5. Many-body problem

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Parry, W.E.

    1973-01-01

    An introduction is given to techniques used in the many-body problem, and a reference book is given for those techniques. Sevcral different formulations of the techniques, and their interrelations, are discussed, to prepare the reader for the published literature. Examples are taken mostly from the physics of solids, fluids and plasmas. Second quantization, perturbation theory, Green functions and correlation functions, examples in the use of diagrammatic perturbation theory, the equation of motion method, magnetism (the drone-fermion representation), linear response and transport processes, niany- body systems at zero temperature, the variational principle and pair-wave approximation. (UK)

  6. The Mind-Body Problem.

    ERIC Educational Resources Information Center

    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)

  7. The Sharma-Parthasarathy stochastic two-body problem

    NASA Astrophysics Data System (ADS)

    Cresson, J.; Pierret, F.; Puig, B.

    2015-03-01

    We study the Sharma-Parthasarathy stochastic two-body problem introduced by Sharma and Parthasarathy in ["Dynamics of a stochastically perturbed two-body problem," Proc. R. Soc. A 463, 979-1003 (2007)]. In particular, we focus on the preservation of some fundamental features of the classical two-body problem like the Hamiltonian structure and first integrals in the stochastic case. Numerical simulations are performed which illustrate the dynamical behaviour of the osculating elements as the semi-major axis, the eccentricity, and the pericenter. We also derive a stochastic version of Gauss's equations in the planar case.

  8. A study of the influence of the sun on optimal two-impulse Earth-to-Moon trajectories with moderate time of flight in the three-body and four-body models

    NASA Astrophysics Data System (ADS)

    Filho, Luiz Arthur Gagg; da Silva Fernandes, Sandro

    2017-05-01

    In this work, a study about the influence of the Sun on optimal two-impulse Earth-to-Moon trajectories for interior transfers with moderate time of flight is presented considering the three-body and the four-body models. The optimization criterion is the total characteristic velocity which represents the fuel consumption of an infinite thrust propulsion system. The optimization problem has been formulated using the classic planar circular restricted three-body problem (PCR3BP) and the planar bi-circular restricted four-body problem (PBR4BP), and, it consists of transferring a spacecraft from a circular low Earth orbit (LEO) to a circular low Moon orbit (LMO) with minimum fuel consumption. The Sequential Gradient Restoration Algorithm (SGRA) is applied to determine the optimal solutions. Numerical results are presented for several final altitudes of a clockwise or a counterclockwise circular low Moon orbit considering a specified altitude of a counterclockwise circular low Earth orbit. Two types of analysis are performed: in the first one, the initial position of the Sun is taken as a parameter and the major parameters describing the optimal trajectories are obtained by solving an optimization problem of one degree of freedom. In the second analysis, an optimization problem with two degrees of freedom is considered and the initial position of the Sun is taken as an additional unknown.

  9. User's guide to four-body and three-body trajectory optimization programs

    NASA Technical Reports Server (NTRS)

    Pu, C. L.; Edelbaum, T. N.

    1974-01-01

    A collection of computer programs and subroutines written in FORTRAN to calculate 4-body (sun-earth-moon-space) and 3-body (earth-moon-space) optimal trajectories is presented. The programs incorporate a variable step integration technique and a quadrature formula to correct single step errors. The programs provide capability to solve initial value problem, two point boundary value problem of a transfer from a given initial position to a given final position in fixed time, optimal 2-impulse transfer from an earth parking orbit of given inclination to a given final position and velocity in fixed time and optimal 3-impulse transfer from a given position to a given final position and velocity in fixed time.

  10. Four-body trajectory optimization

    NASA Technical Reports Server (NTRS)

    Pu, C. L.; Edelbaum, T. N.

    1974-01-01

    A comprehensive optimization program has been developed for computing fuel-optimal trajectories between the earth and a point in the sun-earth-moon system. It presents methods for generating fuel optimal two-impulse trajectories which may originate at the earth or a point in space and fuel optimal three-impulse trajectories between two points in space. The extrapolation of the state vector and the computation of the state transition matrix are accomplished by the Stumpff-Weiss method. The cost and constraint gradients are computed analytically in terms of the terminal state and the state transition matrix. The 4-body Lambert problem is solved by using the Newton-Raphson method. An accelerated gradient projection method is used to optimize a 2-impulse trajectory with terminal constraint. The Davidon's Variance Method is used both in the accelerated gradient projection method and the outer loop of a 3-impulse trajectory optimization problem.

  11. The Sharma-Parthasarathy stochastic two-body problem

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cresson, J.; SYRTE/Observatoire de Paris, 75014 Paris; Pierret, F.

    2015-03-15

    We study the Sharma-Parthasarathy stochastic two-body problem introduced by Sharma and Parthasarathy in [“Dynamics of a stochastically perturbed two-body problem,” Proc. R. Soc. A 463, 979-1003 (2007)]. In particular, we focus on the preservation of some fundamental features of the classical two-body problem like the Hamiltonian structure and first integrals in the stochastic case. Numerical simulations are performed which illustrate the dynamical behaviour of the osculating elements as the semi-major axis, the eccentricity, and the pericenter. We also derive a stochastic version of Gauss’s equations in the planar case.

  12. The collision singularity in a perturbed n-body problem.

    NASA Technical Reports Server (NTRS)

    Sperling, H. J.

    1972-01-01

    Collision of all bodies in a perturbed n-body problem is analyzed by an extension of the author's results for a perturbed two-body problem (1969). A procedure is set forth to prove that the absolute value of energy in a perturbed n-body system remains bounded until the moment of collision. It is shown that the characteristics of motion in both perturbed problems are basically the same.

  13. New central configurations of the (n + 1) -body problem

    NASA Astrophysics Data System (ADS)

    Fernandes, Antonio Carlos; Garcia, Braulio Augusto; Llibre, Jaume; Mello, Luis Fernando

    2018-01-01

    In this article we study central configurations of the (n + 1) -body problem. For the planar (n + 1) -body problem we study central configurations performed by n ≥ 2 bodies with equal masses at the vertices of a regular n-gon and one body with null mass. We also study spatial central configurations considering n bodies with equal masses at the vertices of a regular polyhedron and one body with null mass.

  14. Four-body decays of B meson with lepton number violation

    NASA Astrophysics Data System (ADS)

    Yuan, Han; Wang, Tianhong; Jiang, Yue; Li, Qiang; Wang, Guo-Li

    2018-06-01

    The existence of heavy meson lepton number violating (LNV) processes shows the Majorana nature of the neutrino. Much of this theoretical and experimental researche focuses on this type of decay. Four-body epton-number violation (LNV) processes of the B meson may have sizable branching ratios as they share the same vertex and mixing parameters with the three-body case. Mixing parameters between the heavy Majorana neutrino and charged leptons extracted from the three-body case can be used to constrain the branching ratios of four-body decays of the B meson. So we can update the upper limits of these mixing parameters with new experimental data of the three-body LNV decays. We also analyze {B}0\\to {D}* -{{\\ell }}1+{{\\ell }}2+{M}2- using the updated parameters and estimate some channels’ reconstruction events using current experimental data from Belle.

  15. Symmetries in N-body problem

    NASA Astrophysics Data System (ADS)

    Xia, Zhihong

    2008-09-01

    The purpose of this note is to introduce some of the basic techniques in group theory to the study the symmetries of the Newtonian n-body problem. The main tool is the representations of finite groups.

  16. On the restricted four-body problem with the effect of small perturbations in the Coriolis and centrifugal forces

    NASA Astrophysics Data System (ADS)

    Suraj, Md Sanam; Aggarwal, Rajiv; Arora, Monika

    2017-09-01

    We have studied the restricted four-body problem (R4BP) with the effect of the small perturbation in the Coriolis and centrifugal forces on the libration points and zero velocity curves (ZVCs). Further, we have supposed that all the primaries are set in an equilateral triangle configuration, moving in the circular orbits around their common centre of mass. We have observed that the effect of the small perturbation in centrifugal force has a substantial effect on the location of libration points but a small perturbation in the Coriolis force has no impact on the location of libration points. But the stability of the libration points is highly influenced by the effect of the small perturbation in the Coriolis force. It is observed that as the Coriolis parameter increases, the libration points become stable. Further, it is found that the effect of the small perturbation in the centrifugal force has a substantial influence on the regions of possible motion. Also, when the effect of small perturbation in the centrifugal force increases the forbidden region decreases; here the motion is not possible for the infinitesimal mass. It is observed when the value of the Jacobian constant decreases, the regions of possible motion increase. In addition, we have also discussed how small perturbations in the Coriolis and centrifugal forces influence the Newton-Raphson basins of convergence.

  17. Migrating pharyngeal foreign bodies: a series of four cases of saw-toothed fish bones.

    PubMed

    Chung, Sung Min; Kim, Han Su; Park, Eun Hee

    2008-09-01

    Pharyngeal foreign bodies are common problems seen at emergency rooms or ENT outpatient clinics, and fish bones are the most common foreign bodies encountered in East Asia and in Korea. One of the rare complications of a swallowed sharp fish bone is its migration from the site of entry into the subcutaneous tissues of the neck. We present four unusual cases of ingested fish bones that migrated out of the upper digestive tract to the neck. In the first case, this caused a recurrent deep neck infection for 2 years; in the second case, there was penetration of the facial artery; in the third case, there was a hematoma of the floor of the mouth; in the fourth case, there was a retropharyngeal abscess.

  18. Recurrence formulas for fully exponentially correlated four-body wave functions

    NASA Astrophysics Data System (ADS)

    Harris, Frank E.

    2009-03-01

    Formulas are presented for the recursive generation of four-body integrals in which the integrand consists of arbitrary integer powers (≥-1) of all the interparticle distances rij , multiplied by an exponential containing an arbitrary linear combination of all the rij . These integrals are generalizations of those encountered using Hylleraas basis functions and include all that are needed to make energy computations on the Li atom and other four-body systems with a fully exponentially correlated Slater-type basis of arbitrary quantum numbers. The only quantities needed to start the recursion are the basic four-body integral first evaluated by Fromm and Hill plus some easily evaluated three-body “boundary” integrals. The computational labor in constructing integral sets for practical computations is less than when the integrals are generated using explicit formulas obtained by differentiating the basic integral with respect to its parameters. Computations are facilitated by using a symbolic algebra program (MAPLE) to compute array index pointers and present syntactically correct FORTRAN source code as output; in this way it is possible to obtain error-free high-speed evaluations with minimal effort. The work can be checked by verifying sum rules the integrals must satisfy.

  19. The computationalist reformulation of the mind-body problem.

    PubMed

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  1. The Effective-One-Body Approach to the General Relativistic Two Body Problem

    NASA Astrophysics Data System (ADS)

    Damour, Thibault; Nagar, Alessandro

    The two-body problem in General Relativity has been the subject of many analytical investigations. After reviewing some of the methods used to tackle this problem (and, more generally, the N-body problem), we focus on a new, recently introduced approach to the motion and radiation of (comparable mass) binary systems: the Effective One Body (EOB) formalism. We review the basic elements of this formalism, and discuss some of its recent developments. Several recent comparisons between EOB predictions and Numerical Relativity (NR) simulations have shown the aptitude of the EOB formalism to provide accurate descriptions of the dynamics and radiation of various binary systems (comprising black holes or neutron stars) in regimes that are inaccessible to other analytical approaches (such as the last orbits and the merger of comparable mass black holes). In synergy with NR simulations, post-Newtonian (PN) theory and Gravitational Self-Force (GSF) computations, the EOB formalism is likely to provide an efficient way of computing the very many accurate template waveforms that are needed for Gravitational Wave (GW) data analysis purposes.

  2. Four tails problems for dynamical collapse theories

    NASA Astrophysics Data System (ADS)

    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.

  3. Continuation of periodic orbits in the Sun-Mercury elliptic restricted three-body problem

    NASA Astrophysics Data System (ADS)

    Peng, Hao; Bai, Xiaoli; Xu, Shijie

    2017-06-01

    Starting from resonant Halo orbits in the Circular Restricted Three-Body Problem (CRTBP), Multi-revolution Elliptic Halo (ME-Halo) orbits around L1 and L2 points in the Sun-Mercury Elliptic Restricted Three-Body Problem (ERTBP) are generated systematically. Three pairs of resonant parameters M5N2, M7N3 and M9N4 are tested. The first pair shows special features and is investigated in detail. Three separated characteristic curves of periodic orbit around each libration point are obtained, showing the eccentricity varies non-monotonically along these curves. The eccentricity of the Sun-Mercury system can be achieved by continuation method in just a few cases. The stability analysis shows that these orbits are all unstable and the complex instability occurs with certain parameters. This paper shows new periodic orbits in both the CRTBP and the ERTBP. Totally four periodic orbits with parameters M5N2 around each libration points are extracted in the Sun-Mercury ERTBP.

  4. The 3D elliptic restricted three-body problem: periodic orbits which bifurcate from limiting restricted problems. Complex instability

    NASA Astrophysics Data System (ADS)

    Ollé, Mercè; Pacha, Joan R.

    1999-11-01

    In the present work we use certain isolated symmetric periodic orbits found in some limiting Restricted Three-Body Problems to obtain, by numerical continuation, families of symmetric periodic orbits of the more general Spatial Elliptic Restricted Three Body Problem. In particular, the Planar Isosceles Restricted Three Body Problem, the Sitnikov Problem and the MacMillan problem are considered. A stability study for the periodic orbits of the families obtained - specially focused to detect transitions to complex instability - is also made.

  5. Chaotic Dynamics in the Planar Gravitational Many-Body Problem with Rigid Body Rotations

    NASA Astrophysics Data System (ADS)

    Kwiecinski, James A.; Kovacs, Attila; Krause, Andrew L.; Planella, Ferran Brosa; van Gorder, Robert A.

    The discovery of Pluto’s small moons in the last decade has brought attention to the dynamics of the dwarf planet’s satellites. With such systems in mind, we study a planar N-body system in which all the bodies are point masses, except for a single rigid body. We then present a reduced model consisting of a planar N-body problem with the rigid body treated as a 1D continuum (i.e. the body is treated as a rod with an arbitrary mass distribution). Such a model provides a good approximation to highly asymmetric geometries, such as the recently observed interstellar asteroid ‘Oumuamua, but is also amenable to analysis. We analytically demonstrate the existence of homoclinic chaos in the case where one of the orbits is nearly circular by way of the Melnikov method, and give numerical evidence for chaos when the orbits are more complicated. We show that the extent of chaos in parameter space is strongly tied to the deviations from a purely circular orbit. These results suggest that chaos is ubiquitous in many-body problems when one or more of the rigid bodies exhibits nonspherical and highly asymmetric geometries. The excitation of chaotic rotations does not appear to require tidal dissipation, obliquity variation, or orbital resonance. Such dynamics give a possible explanation for routes to chaotic dynamics observed in N-body systems such as the Pluto system where some of the bodies are highly nonspherical.

  6. The three-body problem with short-range interactions

    NASA Astrophysics Data System (ADS)

    Nielsen, E.; Fedorov, D. V.; Jensen, A. S.; Garrido, E.

    2001-06-01

    The quantum mechanical three-body problem is studied for general short-range interactions. We work in coordinate space to facilitate accurate computations of weakly bound and spatially extended systems. Hyperspherical coordinates are used in both the interpretation and as an integral part of the numerical method. Universal properties and model independence are discussed throughout the report. We present an overview of the hyperspherical adiabatic Faddeev equations. The wave function is expanded on hyperspherical angular eigenfunctions which in turn are found numerically using the Faddeev equations. We generalize the formalism to any dimension of space d greater or equal to two. We present two numerical techniques for solving the Faddeev equations on the hypersphere. These techniques are effective for short and intermediate/large distances including use for hard core repulsive potentials. We study the asymptotic limit of large hyperradius and derive the analytic behaviour of the angular eigenvalues and eigenfunctions. We discuss four applications of the general method. We first analyze the Efimov and Thomas effects for arbitrary angular momenta and for arbitrary dimensions d. Second we apply the method to extract the general behaviour of weakly bound three-body systems in two dimensions. Third we illustrate the method in three dimensions by structure computations of Borromean halo nuclei, the hypertriton and helium molecules. Fourth we investigate in three dimensions three-body continuum properties of Borromean halo nuclei and recombination reactions of helium atoms as an example of direct relevance for the stability of Bose-Einstein condensates.

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

    NASA Astrophysics Data System (ADS)

    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.

  8. The Psychological Four-Color Mapping Problem

    ERIC Educational Resources Information Center

    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…

  9. Three- and four-body nonadditivities in nucleic acid tetramers: a CCSD(T) study.

    PubMed

    Pitonák, M; Neogrády, P; Hobza, P

    2010-02-14

    Three- and four-body nonadditivities in the uracil tetramer (in DNA-like geometry) and the GC step (in crystal geometry) were investigated at various levels of the wave-function theory: HF, MP2, MP3, L-CCD, CCSD and CCSD(T). All of the calculations were performed using the 6-31G**(0.25,0.15) basis set, whereas the HF, MP2 and the MP3 nonadditivities were, for the sake of comparison, also determined with the much larger aug-cc-pVDZ basis set. The HF and MP2 levels do not provide reliable values for many-body terms, making it necessary to go beyond the MP2 level. The benchmark CCSD(T) three- and four-body nonadditivities are reasonably well reproduced at the MP3 level, and almost quantitative agreement is obtained (fortuitously) either on the L-CCD level or as an average of the MP3 and the CCSD results. Reliable values of many-body terms (especially their higher-order correlation contributions) are obtained already when the rather small 6-31G**(0.25,0.15) basis set is used. The four-body term is much smaller when compared to the three-body terms, but it is definitely not negligible, e.g. in the case of the GC step it represents about 16% of all of the three- and four-body terms. While investigating the geometry dependence of many-body terms for the GG step at the MP3/6-31G**(0.25,0.15) level, we found that it is necessary to include at least three-body terms in the determination of optimal geometry parameters.

  10. Body image and sexual problems in young women with breast cancer.

    PubMed

    Fobair, Pat; Stewart, Susan L; Chang, Subo; D'Onofrio, Carol; Banks, Priscilla J; Bloom, Joan R

    2006-07-01

    The purpose of this study was to determine the frequency of body image and sexual problems in the first months after treatment among women diagnosed with breast cancer at age 50 or younger. Breast cancer treatment may have severe effects on the bodies of younger women. Surgical treatment may be disfiguring, chemotherapy may cause abrupt menopause, and hormone replacement is not recommended. A multi-ethnic population-based sample of 549 women aged 22-50 who were married or in a stable unmarried relationship were interviewed within seven months of diagnosis with in situ, local, or regional breast cancer. Body image and sexual problems were experienced by a substantial proportion of women in the early months after diagnosis. Half of the 546 women experienced two or more body image problems some of the time (33%), or at least one problem much of the time (17%). Among sexually active women, greater body image problems were associated with mastectomy and possible reconstruction, hair loss from chemotherapy, concern with weight gain or loss, poorer mental health, lower self-esteem, and partner's difficulty understanding one's feelings. Among the 360 sexually active women, half (52%) reported having a little problem in two or more areas of sexual functioning (24%), or a definite or serious problem in at least one area (28%). Greater sexual problems were associated with vaginal dryness, poorer mental health, being married, partner's difficulty understanding one's feelings, and more body image problems, and there were significant ethnic differences in reported severity. Difficulties related to sexuality and sexual functioning were common and occurred soon after surgical and adjuvant treatment. Addressing these problems is essential to improve the quality of life of young women with breast cancer.

  11. Analysis of four-body decay of D meson

    NASA Astrophysics Data System (ADS)

    Estabar, T.; Mehraban, H.

    2017-01-01

    The aim of this work is to provide a phenomenological analysis of the contribution of D0 meson to f0(980)π+π-(f 0(980) → π+π-), K+K-K¯∗(982)0(K¯∗(982)0 → π+K-) and ϕ(π+π-) S-wave(ϕ → K+K-) quasi-three-body decays. Such that the analysis of mentioned four-body decays is summarized into three-body decay and several channels are observed. Based on the factorization approach, hadronic three-body decays receive both resonant and nonresonant contributions. We compute both contributions of three-body decays. As, there are tree, penguin, emission, and emission annihilation diagrams for these decay modes. Our theoretical model for D0 → ϕ(ππ) S-wave decay is based on the QCD factorization to quasi-two body followed by S-wave. This model for this decay following experimental information which demonstrated two pion interaction in the S-wave is introduced by the scalar resonance. The theoretical values are (1.82 ± 0.24) × 10-4, (4.46 ± 0.41) × 10-5 and (1.1 ± 0.18) × 10-4, while the experimental results of them are (1.8 ± 0.5) × 10-4, (4.4 ± 1.7) × 10-5 and (2.5 ± 0.33) × 10-4, respectively. Comparing computation analysis values with experimental values show that our results are in agreement with them.

  12. Quaternion Regularization of the Equations of the Perturbed Spatial Restricted Three-Body Problem: I

    NASA Astrophysics Data System (ADS)

    Chelnokov, Yu. N.

    2017-11-01

    We develop a quaternion method for regularizing the differential equations of the perturbed spatial restricted three-body problem by using the Kustaanheimo-Stiefel variables, which is methodologically closely related to the quaternion method for regularizing the differential equations of perturbed spatial two-body problem, which was proposed by the author of the present paper. A survey of papers related to the regularization of the differential equations of the two- and threebody problems is given. The original Newtonian equations of perturbed spatial restricted three-body problem are considered, and the problem of their regularization is posed; the energy relations and the differential equations describing the variations in the energies of the system in the perturbed spatial restricted three-body problem are given, as well as the first integrals of the differential equations of the unperturbed spatial restricted circular three-body problem (Jacobi integrals); the equations of perturbed spatial restricted three-body problem written in terms of rotating coordinate systems whose angular motion is described by the rotation quaternions (Euler (Rodrigues-Hamilton) parameters) are considered; and the differential equations for angular momenta in the restricted three-body problem are given. Local regular quaternion differential equations of perturbed spatial restricted three-body problem in the Kustaanheimo-Stiefel variables, i.e., equations regular in a neighborhood of the first and second body of finite mass, are obtained. The equations are systems of nonlinear nonstationary eleventhorder differential equations. These equations employ, as additional dependent variables, the energy characteristics of motion of the body under study (a body of a negligibly small mass) and the time whose derivative with respect to a new independent variable is equal to the distance from the body of negligibly small mass to the first or second body of finite mass. The equations obtained in

  13. The changing features of the body-mind problem.

    PubMed

    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].

  14. A psychiatric dialogue on the mind-body problem.

    PubMed

    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.

  15. Some solutions of the general three body problem in form space

    NASA Astrophysics Data System (ADS)

    Titov, Vladimir

    2018-05-01

    Some solutions of three body problem with equal masses are first considered in form space. The solutions in usual euclidean space may be restored from these form space solutions. If constant energy h < 0, the trajectories are located inside of Hill's surface. Without loss of generality due to scale symmetry we can set h = -1. Such surface has a simple form in form space. Solutions of isosceles and rectilinear three body problems lie within Hill's curve; periodic solutions of free fall three body problem start in one point of this curve, and finish in another. The solutions are illustrated by number of figures.

  16. Search for and Study of Nearly Periodic Orbits in the Plane Problem of Three Equal-Mass Bodies

    NASA Astrophysics Data System (ADS)

    Martynova, A. I.; Orlov, V. V.

    2005-09-01

    We analyze nearly periodic solutions in the plane problem of three equal-mass bodies by numerically simulating the dynamics of triple systems. We identify families of orbits in which all three points are on one straight line (syzygy) at the initial time. In this case, at fixed total energy of a triple system, the set of initial conditions is a bounded region in four-dimensional parameter space. We scan this region and identify sets of trajectories in which the coordinates and velocities of all bodies are close to their initial values at certain times (which are approximately multiples of the period). We classify the nearly periodic orbits by the structure of trajectory loops over one period. We have found the families of orbits generated by von Schubart’s stable periodic orbit revealed in the rectilinear three-body problem. We have also found families of hierarchical, nearly periodic trajectories with prograde and retrograde motions. In the orbits with prograde motions, the trajectory loops of two close bodies form looplike structures. The trajectories with retrograde motions are characterized by leafed structures. Orbits with central and axial symmetries are identified among the families found.

  17. Symmetries and "simple" solutions of the classical n-body problem

    NASA Astrophysics Data System (ADS)

    Chenciner, Alain

    2006-03-01

    The Lagrangian of the classical n-body problem has well known symmetries: isometries of the ambient Euclidean space (translations, rotations, reflexions) and changes of scale coming from the homogeneity of the potential. To these symmetries are associated "simple" solutions of the problem, the so-called homographic motions, which play a basic role in the global understanding of the dynamics. The classical subproblems (planar, isosceles) are also consequences of the existence of symmetries: invariance under reflexion through a plane in the first case, invariance under exchange of two equal masses in the second. In these two cases, the symmetry acts at the level of the "shape space" (the oriented one in the first case) whose existence is the main difference between the 2-body problem and the (n ≥ 3)-body problem. These symmetries of the Lagrangian imply symmetries of the action functional, which is defined on the space of regular enough loops of a given period in the configuration space of the problem. Minimization of the action under well-chosen symmetry constraints leads to remarkable solutions of the n-body problem which may also be called simple and could play after the homographic ones the role of organizing centers in the global dynamics. In [13] and [16], I have given a survey of the new classes of solutions which had been obtained in this way, mainly choreographies of n equal masses in a plane or in space and generalized Hip-Hops of at least 4 arbitrary masses in space. I give here an updated overview of the results and a quick glance at the methods of proofs.

  18. Invariant Manifolds, the Spatial Three-Body Problem and Space Mission Design

    NASA Technical Reports Server (NTRS)

    Gomez, G.; Koon, W. S.; Lo, Martin W.; Marsden, J. E.; Masdemont, J.; Ross, S. D.

    2001-01-01

    The invariant manifold structures of the collinear libration points for the spatial restricted three-body problem provide the framework for understanding complex dynamical phenomena from a geometric point of view. In particular, the stable and unstable invariant manifold 'tubes' associated to libration point orbits are the phase space structures that provide a conduit for orbits between primary bodies for separate three-body systems. These invariant manifold tubes can be used to construct new spacecraft trajectories, such as 'Petit Grand Tour' of the moons of Jupiter. Previous work focused on the planar circular restricted three-body problem. The current work extends the results to the spatial case.

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

    NASA Astrophysics Data System (ADS)

    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.

  20. On the characteristic exponents of the general three-body problem

    NASA Technical Reports Server (NTRS)

    Broucke, R.

    1976-01-01

    A description is given of some properties of the characteristic exponents of the general three-body problem. The variational equations on which the analysis is based are obtained by linearizing the Lagrangian equations of motion in the neighborhood of a given known solution. Attention is given to the fundamental matrix of solutions, the characteristic equation, the three trivial solutions of the variational equations of the three-body problem, symmetric periodic orbits, and the half-period properties of symmetric periodic orbits.

  1. Relative equilibria in quasi-homogeneous planar three body problems

    NASA Astrophysics Data System (ADS)

    Arredondo, John A.

    2018-01-01

    In this paper we find the families of relative equilibria for the three body problem in the plane, when the interaction between the bodies is given by a quasi-homogeneous potential. The number of the relative equilibria depends on the values of the masses and on the size of the system, measured by the moment of inertia.

  2. Satellite capture as a restricted 2 + 2 body problem

    NASA Astrophysics Data System (ADS)

    Kanaan, Wafaa; Farrelly, David; Lanchares, Víctor

    2018-04-01

    A restricted 2 + 2 body problem is proposed as a possible mechanism to explain the capture of small bodies by a planet. In particular, we consider two primaries revolving in a circular mutual orbit and two small bodies of equal mass, neither of which affects the motion of the primaries. If the small bodies are temporarily captured in the Hill sphere of the smaller primary, they may get close enough to each other to exchange energy in such a way that one of them becomes permanently captured. Numerical simulations show that capture is possible for both prograde and retrograde orbits.

  3. Action-minimizing solutions of the one-dimensional N-body problem

    NASA Astrophysics Data System (ADS)

    Yu, Xiang; Zhang, Shiqing

    2018-05-01

    We supplement the following result of C. Marchal on the Newtonian N-body problem: A path minimizing the Lagrangian action functional between two given configurations is always a true (collision-free) solution when the dimension d of the physical space R^d satisfies d≥2. The focus of this paper is on the fixed-ends problem for the one-dimensional Newtonian N-body problem. We prove that a path minimizing the action functional in the set of paths joining two given configurations and having all the time the same order is always a true (collision-free) solution. Considering the one-dimensional N-body problem with equal masses, we prove that (i) collision instants are isolated for a path minimizing the action functional between two given configurations, (ii) if the particles at two endpoints have the same order, then the path minimizing the action functional is always a true (collision-free) solution and (iii) when the particles at two endpoints have different order, although there must be collisions for any path, we can prove that there are at most N! - 1 collisions for any action-minimizing path.

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

    NASA Astrophysics Data System (ADS)

    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.

  5. Hip-hop solutions of the 2N-body problem

    NASA Astrophysics Data System (ADS)

    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.

  6. The topology of the regularized integral surfaces of the 3-body problem

    NASA Technical Reports Server (NTRS)

    Easton, R.

    1971-01-01

    Momentum, angular momentum, and energy of integral surfaces in the planar three-body problem are considered. The end points of orbits which cross an isolating block are identified. It is shown that this identification has a unique extension to an identification which pairs the end points of orbits entering the block and which end in a binary collision with the end points of orbits leaving the block and which come from a binary collision. The problem of regularization is that of showing that the identification of the end points of crossing orbits has a continuous, unique extension. The regularized phase space for the three-body problem was obtained, as were regularized integral surfaces for the problem on which the three-body equations of motion induce flows. Finally the topology of these surfaces is described.

  7. Four-body extension of the continuum-discretized coupled-channels method

    NASA Astrophysics Data System (ADS)

    Descouvemont, P.

    2018-06-01

    I develop an extension of the continuum-discretized coupled-channels (CDCC) method to reactions where both nuclei present a low breakup threshold. This leads to a four-body model, where the only inputs are the interactions describing the colliding nuclei, and the four optical potentials between the fragments. Once these potentials are chosen, the model does not contain any additional parameter. First I briefly discuss the general formalism, and emphasize the need for dealing with large coupled-channel systems. The method is tested with existing benchmarks on 4 α bound states with the Ali-Bodmer potential. Then I apply the four-body CDCC to the 11Be+d system, where I consider the 10Be(0+,2+)+n configuration for 11Be. I show that breakup channels are crucial to reproduce the elastic cross section, but that core excitation plays a weak role. The 7Li+d system is investigated with an α +t cluster model for 7Li. I show that breakup channels significantly improve the agreement with the experimental cross section, but an additional imaginary term, simulating missing transfer channels, is necessary. The full CDCC results can be interpreted by equivalent potentials. For both systems, the real part is weakly affected by breakup channels, but the imaginary part is strongly modified. I suggest that the present wave functions could be used in future DWBA calculations.

  8. Institutional Solutions to the ``Two-Body Problem"

    NASA Astrophysics Data System (ADS)

    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.

  9. The Cyclic Nature of Problem Solving: An Emergent Multidimensional Problem-Solving Framework

    ERIC Educational Resources Information Center

    Carlson, Marilyn P.; Bloom, Irene

    2005-01-01

    This paper describes the problem-solving behaviors of 12 mathematicians as they completed four mathematical tasks. The emergent problem-solving framework draws on the large body of research, as grounded by and modified in response to our close observations of these mathematicians. The resulting "Multidimensional Problem-Solving Framework" has four…

  10. Central Configurations of the Curved N-Body Problem

    NASA Astrophysics Data System (ADS)

    Diacu, Florin; Stoica, Cristina; Zhu, Shuqiang

    2018-06-01

    We consider the N-body problem of celestial mechanics in spaces of nonzero constant curvature. Using the concept of effective potential, we define the moment of inertia for systems moving on spheres and hyperbolic spheres and show that we can recover the classical definition in the Euclidean case. After proving some criteria for the existence of relative equilibria, we find a natural way to define the concept of central configuration in curved spaces using the moment of inertia and show that our definition is formally similar to the one that governs the classical problem. We prove that, for any given point masses on spheres and hyperbolic spheres, central configurations always exist. We end with results concerning the number of central configurations that lie on the same geodesic, thus extending the celebrated theorem of Moulton to hyperbolic spheres and pointing out that it has no straightforward generalization to spheres, where the count gets complicated even for two bodies.

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

    PubMed

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  13. Pavlov and the mind-body problem.

    PubMed

    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.

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

    PubMed

    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.

  15. Full three-body problem in effective-field-theory models of gravity

    NASA Astrophysics Data System (ADS)

    Battista, Emmanuele; Esposito, Giampiero

    2014-10-01

    Recent work in the literature has studied the restricted three-body problem within the framework of effective-field-theory models of gravity. This paper extends such a program by considering the full three-body problem, when the Newtonian potential is replaced by a more general central potential which depends on the mutual separations of the three bodies. The general form of the equations of motion is written down, and they are studied when the interaction potential reduces to the quantum-corrected central potential considered recently in the literature. A recursive algorithm is found for solving the associated variational equations, which describe small departures from given periodic solutions of the equations of motion. Our scheme involves repeated application of a 2×2 matrix of first-order linear differential operators.

  16. Mathematical Giftedness, Problem Solving, and the Ability To Formulate Generalizations: The Problem-Solving Experiences of Four Gifted Students.

    ERIC Educational Resources Information Center

    Sriraman, Bharath

    2003-01-01

    Nine freshmen in a ninth-grade accelerated algebra class were asked to solve five nonroutine combinatorial problems. The four mathematically gifted students were successful in discovering and verbalizing the generality that characterized the solutions to the five problems, whereas the five nongifted students were unable to discover the hidden…

  17. The three-body problem and equivariant Riemannian geometry

    NASA Astrophysics Data System (ADS)

    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.

  18. The family of planar periodic orbits generated by the equal-mass four-body Schubart interplay orbit

    NASA Astrophysics Data System (ADS)

    Chopovda, Valerie; Sweatman, Winston L.

    2018-05-01

    We locate members of a one-parameter family of equal-mass four-body periodic orbits in the plane. The family begins and ends with the rectilinear four-body equal-mass Schubart interplay orbit and passes through a double choreography orbit. The first-order stability of these orbits is computed. Some members of this symmetric family are stable to symmetric perturbations; however, they are unstable when all perturbations are allowed.

  19. Two-body problem in scalar-tensor theories as a deformation of general relativity: An effective-one-body approach

    NASA Astrophysics Data System (ADS)

    Julié, Félix-Louis; Deruelle, Nathalie

    2017-06-01

    In this paper we address the two-body problem in massless scalar-tensor (ST) theories within an effective-one-body (EOB) framework. We focus on the first building block of the EOB approach, that is, mapping the conservative part of the two-body dynamics onto the geodesic motion of a test particle in an effective external metric. To this end, we first deduce the second post-Keplerian (2PK) Hamiltonian of the two-body problem from the known 2PK Lagrangian. We then build, by means of a canonical transformation, a ST deformation of the general relativistic EOB Hamiltonian that allows us to incorporate the scalar-tensor (2PK) corrections to the currently best available general relativity EOB results. This EOB-ST Hamiltonian defines a resummation of the dynamics that may provide information on the strong-field regime, in particular, the ISCO location and associated orbital frequency, and can be compared to, other, e.g., tidal, corrections.

  20. Inverse problem of central configurations in the collinear 5-body problem

    NASA Astrophysics Data System (ADS)

    Davis, Candice; Geyer, Scott; Johnson, William; Xie, Zhifu

    2018-05-01

    In this paper, we study the inverse problem of collinear central configurations of a 5-body problem: given a collinear configuration q = (-s - 1, -1, r, 1, t + 1) of 5 bodies, does there exist positive masses to make the configuration central? Here we proved the following results: If r = 0 and s = t > 0, there always exist positive masses to make the configuration central and the masses are symmetrical such that m1 = m5, m2 = m4, and m3 is an arbitrary parameter. Specially if r = 0 and s =t =s ¯ , the configuration q =(-s ¯ -1 ,-1,0,1 ,s ¯ +1 ) is always a central configuration for any positive masses 0 < m2 = m4 < ∞ when m1 = m5 are fixed at particular values, which only depend on s ¯ and m3. s ¯ is the unique real root of a fifth order polynomial and numerically s ¯ ≈1.396 812 289 . If r = 0 and s ≠ t > 0, there also always exist positive masses to make the configuration central. For any r ∈ (0, 1) [or r ∈ (-1, 0)], there exist a set E14 (or E25) in the first quadrant of st-plane where every configuration is a central configuration for some positive masses. However, no configuration in the complement of E14 (or E25) is a central configuration for any positive masses.

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

    PubMed

    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.

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

    PubMed

    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.

  3. Four years of problem-based learning: a student's perspective.

    PubMed Central

    von Doebeln, G.

    1996-01-01

    After four years as a student in a medical school using problem-based learning I still find it an excellent way to learn. Group work has developed my personal skills and abilities. Learning how to obtain knowledge on my own has given me independence and confidence. Motivation to study has been encouraged by early clinical experience. Training in critical thinking has been further enhanced by in-depth studies. Medical education at the University of Linkoping has developed over the years and a contributing factor has been students' involvement in designing the medical training. There are benefits and disadvantages with problem-based learning, but on the whole it is an enjoyable and fruitful experience. Images p98-a PMID:8871459

  4. Four and Five-body non-local correlations in pure and mixed states

    NASA Astrophysics Data System (ADS)

    Sharma, Santosh Shelly; Sharma, Naresh Kumar

    2014-03-01

    In our earlier works, quantifiers of four and three-body correlations based on four qubit invariants had been constructed for pure states. The principal construction tools, local unitary invariance and notion of negativity fonts, make it possible to outline the process of selective construction of meaningful invariants that quanify N and N - 1 qubit correlations. It is found that, in general, starting from degree k invariants relevant to detection and quantifcation of specific type of non-local quantum correlations in (N - 1) (N > 2) qubit system, one can construct degree k coefficients of an N-qubit bilinear form. When k =2 N - 2 (N > 2), one of the invariants of degree 2 N - 1 quantifies N-body non-local correlations The process is recursive. While for few body systems it yields analytical expressions in terms of functions of state coefficients, for larger systems it can be the guiding principle to numerical caculations of invariants. To illustrate the process, an expression for a five qubit correlation quantifier for pure states is constructed. In addition, the extension to specific rank two mixed states through convex-roof extension is investigated. We gratefully acknowledge Financial support from CNPq Brazil and Fundacao Araucaria PR Brazil.

  5. Post-Newtonian Circular Restricted 3-Body Problem: Schwarzschild primaries

    NASA Astrophysics Data System (ADS)

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

    2017-07-01

    The restricted three-body problem (RTBP) has been extensively studied to investigate the stability of the solar system, extra-solar subsystems, asteroid capture, and the dynamics of two massive black holes orbited by a sun. In the present work, we study the stability of the planar circular restricted three-body problem in the context of post-Newtonian approximations. First of all, we review the results obtained from the post-Newtonian equations of motion calculated in the framework of the Einstein-Infeld-Hoffmann formalism (EIH). Therefore, using the Fodor-Hoenselers-Perjes formalism (FHP), we have performed an expansion of the gravitational potential for two primaries, deriving a new system of equations of motion, which unlike the EIH-approach, preserves the Jacobian integral of motion. Additionally, we have obtained approximate expressions for the Lagrange points in terms of a mass parameter μ, where it is found that the deviations from the classical regime are larger for the FHP than for the EIH equations.

  6. Equations of motion for the gravitational two-body problem

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Whitney, C.K.

    1988-01-01

    This paper reinvestigates the well-known gravitational two-body problem, in light of new information concerning the electrodynamic version of the problem. The well-known Lienard-Wiechert potentials, and the fields derived from them, are suspected to be time-shifted, anticipating the true potentials and fields by the time required for signal propagation from the source to the observer. This time shift is significant because it implies field directions different to first order in v/c. In the gravitational problem, the resulting observer accelerations become correlated with retarded source positions, rather than with present, unretarded source positions as was previously believed. This means there exist previouslymore » unrecognized first-order effects in gravitational systems.« less

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

    NASA Astrophysics Data System (ADS)

    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

  8. Effects of Energy Dissipation in the Sphere-Restricted Full Three-Body Problem

    NASA Astrophysics Data System (ADS)

    Gabriel, T. S. J.

    Recently, the classical N-Body Problem has been adjusted to account for celestial bodies made of constituents of finite density. By imposing a minima on the achievable distance between particles, minimum energy resting states are allowed by the problem. The Full N-Body Problem allows for the dissipation of mechanical energy through surface-surface interactions via impacts or by way of tidal deformation. Barring exogeneous forces and allowing for the dissipation of energy, these systems have discrete, and sometimes multiple, minimum energy states for a given angular momentum. Building the dynamical framework of such finite density systems is a necessary process in outlining the evolution of rubble pile asteroids and other gravitational-granular systems such as protoplanetary discs, and potentially planetary rings, from a theoretical point of view. In all cases, resting states are expected to occur as a necessary step in the ongoing processes of solar system formation and evolution. Previous studies of this problem have been performed in the N=3 case where the bodies are indistinguishable spheres, with all possible relative equilibria and their stability having been identified as a function of the angular momentum of the system. These studies uncovered that at certain levels of angular momentum there exists two minimum energy states, a global and local minimum. Thus a question of interest is in which of these states a dissipative system would preferentially settle and the sensitivity of results to changes in dissipation parameters. Assuming equal-sized, perfectly-rigid bodies, this study investigates the dynamical evolution of three spheres under the influence of mutual gravity and impact mechanics as a function of dissipation parameters. A purpose-written, C-based, Hard Sphere Discrete Element Method code has been developed to integrate trajectories and resolve contact mechanics as grains evolve into minimum energy configurations. By testing many randomized initial

  9. Problem Solving Ability of Disadvantaged Children Under Four Test Modes.

    ERIC Educational Resources Information Center

    Houtz, John C.; And Others

    A study was conducted to test the hypothesis that Ss from disadvantaged homes have poorly developed "abstract" thinking skills and that their thought can be characterized as more "concrete" or relational. Four forms of a problem-solving inventory were developed which differed in mode of presentation. The original form consisted of real-life…

  10. The Four Es 1-year later: a tool for predicting the development of gambling problems.

    PubMed

    Rockloff, Matthew J; Dyer, Victoria

    2007-12-01

    The Four Es is a 40-item scale measuring psychological risk for the development of problem gambling behavior. One-year follow-up interviews (n = 395) from a previously reported phone survey in Queensland, Australia (n = 2,577) (Rockloff & Dyer, 2006) tested the ability of the Four Es instrument to prospectively identify persons who would later develop gambling problems. Two groups of participants were selected for the 1-year follow-up interviews, including (1) persons who had gambling problems, high-risk alcohol abuse problems, and/or substance abuse problems (abuse group); and (2) a random selection of other persons from the original survey (random group). The results indicated that the "Excess" trait, which measures impulsive behavior, was predictive of relative increases in gambling problems for both groups over the 1-year period. Additionally, the Four Es questionnaire showed good psychometric properties in the surveys, with a test-retest reliability of r = .70 and a Cronbach's alpha reliability of alpha = .90 and .92 in the original and follow-up interviews, respectively.

  11. The Evaluation of Four Mind/Body Intervention Strategies to Reduce Perceived Stress among College Students

    ERIC Educational Resources Information Center

    Winterdyk, John; Ray, Heather; Lafave, Lynne; Flessati, Sonya; Huston, Michael; Danelesko, Elaine; Murray, Christina

    2008-01-01

    We examined the effectiveness of four distinct mind/body interventions on reported perceived stress, anxiety, and health promoting behaviours in college students. Ninety students were randomly assigned to one of four experimental groups (i.e., nutritional, exercise, relaxation, or cognitive behavioural therapy). There were approximately 18…

  12. Fast and reliable symplectic integration for planetary system N-body problems

    NASA Astrophysics Data System (ADS)

    Hernandez, David M.

    2016-06-01

    We apply one of the exactly symplectic integrators, which we call HB15, of Hernandez & Bertschinger, along with the Kepler problem solver of Wisdom & Hernandez, to solve planetary system N-body problems. We compare the method to Wisdom-Holman (WH) methods in the MERCURY software package, the MERCURY switching integrator, and others and find HB15 to be the most efficient method or tied for the most efficient method in many cases. Unlike WH, HB15 solved N-body problems exhibiting close encounters with small, acceptable error, although frequent encounters slowed the code. Switching maps like MERCURY change between two methods and are not exactly symplectic. We carry out careful tests on their properties and suggest that they must be used with caution. We then use different integrators to solve a three-body problem consisting of a binary planet orbiting a star. For all tested tolerances and time steps, MERCURY unbinds the binary after 0 to 25 years. However, in the solutions of HB15, a time-symmetric HERMITE code, and a symplectic Yoshida method, the binary remains bound for >1000 years. The methods' solutions are qualitatively different, despite small errors in the first integrals in most cases. Several checks suggest that the qualitative binary behaviour of HB15's solution is correct. The Bulirsch-Stoer and Radau methods in the MERCURY package also unbind the binary before a time of 50 years, suggesting that this dynamical error is due to a MERCURY bug.

  13. Symmetric Trajectories for the 2N-Body Problem with Equal Masses

    NASA Astrophysics Data System (ADS)

    Terracini, Susanna; Venturelli, Andrea

    2007-06-01

    We consider the problem of 2 N bodies of equal masses in mathbb{R}^3 for the Newtonian-like weak-force potential r -σ, and we prove the existence of a family of collision-free nonplanar and nonhomographic symmetric solutions that are periodic modulo rotations. In addition, the rotation number with respect to the vertical axis ranges in a suitable interval. These solutions have the hip-hop symmetry, a generalization of that introduced in [19], for the case of many bodies and taking account of a topological constraint. The argument exploits the variational structure of the problem, and is based on the minimization of Lagrangian action on a given class of paths.

  14. Numerical method for solving the nonlinear four-point boundary value problems

    NASA Astrophysics Data System (ADS)

    Lin, Yingzhen; Lin, Jinnan

    2010-12-01

    In this paper, a new reproducing kernel space is constructed skillfully in order to solve a class of nonlinear four-point boundary value problems. The exact solution of the linear problem can be expressed in the form of series and the approximate solution of the nonlinear problem is given by the iterative formula. Compared with known investigations, the advantages of our method are that the representation of exact solution is obtained in a new reproducing kernel Hilbert space and accuracy of numerical computation is higher. Meanwhile we present the convergent theorem, complexity analysis and error estimation. The performance of the new method is illustrated with several numerical examples.

  15. Free time minimizers for the three-body problem

    NASA Astrophysics Data System (ADS)

    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.

  16. Compact normalisations in the elliptic restricted three body problem

    NASA Astrophysics Data System (ADS)

    Palacián, Jesús F.; Vanegas, Jasson; Yanguas, Patricia

    2017-11-01

    This paper considers the spatial elliptic restricted three body problem in the case that the particle with negligible mass is revolving around one of the primaries. The system is modelled in an inertial frame through a Hamiltonian function representing a non-autonomous dynamical system with three degrees of freedom that depends periodically on time. Three Lie transformations are applied at first order to eliminate successively the mean anomaly of the infinitesimal particle's motion, the time dependence of the system and the argument of the node of the particle with negligible mass. All the transformations are implemented in a compact way, that is, carrying out the computations by means of infinite series. This approach can be very useful to deal with certain artificial satellite problems or, in general, with systems such that the ratio between the distance of the infinitesimal particle to the body around it orbits and the distance between the two primaries is smaller than one but close to it. In this case the Legendre expansion of the potential converges slowly and many terms of the series must be taken into consideration.

  17. Numerical study of the geometry of the phase space of the Augmented Hill Three-Body problem

    NASA Astrophysics Data System (ADS)

    Farrés, Ariadna; Jorba, Àngel; Mondelo, Josep-Maria

    2017-09-01

    The Augmented Hill Three-Body problem is an extension of the classical Hill problem that, among other applications, has been used to model the motion of a solar sail around an asteroid. This model is a 3 degrees of freedom (3DoF) Hamiltonian system that depends on four parameters. This paper describes the bounded motions (periodic orbits and invariant tori) in an extended neighbourhood of some of the equilibrium points of the model. An interesting feature is the existence of equilibrium points with a 1:1 resonance, whose neighbourhood we also describe. The main tools used are the computation of periodic orbits (including their stability and bifurcations), the reduction of the Hamiltonian to centre manifolds at equilibria, and the numerical approximation of invariant tori. It is remarkable how the combination of these techniques allows the description of the dynamics of a 3DoF Hamiltonian system.

  18. Finite difference solutions of heat conduction problems in multi-layered bodies with complex geometries

    NASA Technical Reports Server (NTRS)

    Masiulaniec, K. C.; Keith, T. G., Jr.; Dewitt, K. J.

    1984-01-01

    A numerical procedure is presented for analyzing a wide variety of heat conduction problems in multilayered bodies having complex geometry. The method is based on a finite difference solution of the heat conduction equation using a body fitted coordinate system transformation. Solution techniques are described for steady and transient problems with and without internal energy generation. Results are found to compare favorably with several well known solutions.

  19. End-State Relative Equilibria in the Sphere-Restricted Full Three-Body Problem

    NASA Astrophysics Data System (ADS)

    Gabriel, Travis; Scheeres, Daniel J.

    2015-05-01

    The Sphere-Restricted Full Three-Body Problem studies the motion of three finite density spheres as they interact under surface and gravitational forces. When accounting for the dissipation of energy, full-body systems may achieve minimum energy states that are unatainable in the classic treatment of the N-Body Problem. This serves as a simple model for the mechanics of rubble pile asteroids, interacting grains in a protoplanetary disk, and potentially the interactions of planetary ring particles. Previous studies of this problem have been performed in the case where the three spheres are of equal size and mass, with all possible relative equilibria and their stability having been identified as a function of the total angular momentum of the system. These studies uncovered that at certain levels of angular momentum there exists more than one stable relative equilibrium state. Thus a question of interest is which of these states a dissipative system would preferentially settle in provided some domain of initial conditions, and whether this would be a function of the dissipation parameters. Using perfectly-rigid dynamics, three-equal-sphere systems are simulated in a purpose-written C-based code to uncover these details. Results from this study are relevant to the mechanics and dynamics in small solar system bodies where relative forces are not great enough to compromise the rigidity of the constituents.

  20. Few-body problem in terms of correlated Gaussians

    NASA Astrophysics Data System (ADS)

    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.

  1. Age, Physical Activity, Physical Fitness, Body Composition, and Incidence of Orthopedic Problems.

    ERIC Educational Resources Information Center

    Research Quarterly for Exercise and Sport, 1989

    1989-01-01

    Effects of age, physical activity, physical fitness, and body mass index (BMI) on the occurrence of orthopedic problems were examined. For men, physical fitness, BMI, and physical activity were associated with orthopedic problems; for women, physical activity was the main predictor. Age was not a factor for either gender. (JD)

  2. Dark energy in the three-body problem: Wide triple galaxies

    NASA Astrophysics Data System (ADS)

    Emel'yanov, N. V.; Kovalev, M. Yu.; Chernin, A. D.

    2016-04-01

    The structure and evolution of triple galaxy systems in the presence of the cosmic dark-energy background is studied in the framework of the three-body problem. The dynamics of wide triple systems are determinedmainly by the competition between the mutual gravitational forces between the three bodies and the anti-gravity created by the dark-energy background. This problem can be solved via numerical integration of the equations of motion with initial conditions that admit various types of evolutionary behavior of the system. Such dynamical models show that the anti-gravity created by dark energy makes a triple system less tightly bound, thereby facilitating its decay, with a subsequent transition to motion of the bodies away from each other in an accelerating regime with a linear Hubble-law dependence of the velocity on distance. The coefficient of proportionality between the velocity and distance in this asymptotic relation corresponds to the universal value H Λ = 61 km s-1 Mpc-1, which depends only on the dark-energy density. The similarity of this relation to the large-scale recession of galaxies indicates that double and triple galaxies represent elementary dynamical cells realizing the overall behavior of a system dominated by dark energy on their own scale, independent of their masses and dimensions.

  3. [Knee-related Pain Problems during Pregnancy Correlate with an Increase in Body Weight. Results of a Prospective Study].

    PubMed

    Spahn, G; Lesser, A; Hofmann, G O; Schiele, R

    2015-10-01

    This study aimed to evaluate the incidence of knee pain or the intensification of knee-related problems during pregnancy. We hypothesised that the occurrence of knee problems correlates with an increase in body weight during pregnancy. A total of 326 women (30(th)-40(th) week of pregnancy) were involved in this study. At onset of the pregnancy, the patients were 29.4 [95% CI 28.8-29.9] years of age. We asked all patients retrospectively about their anthropometric data at the beginning of pregnancy. All patients provided information about former knee problems, knee problems occurring after onset of pregnancy or any increase in these problems. These knee patients were re-evaluated 6 weeks after childbirth. At follow-up, the patients were asked about their knee problems and about their body weight. At the beginning of pregnancy, the mean body weight was 68.0 kg (95% CI 64.4-69.6; range 41-117). The mean BMI of all patients was 24.5 kg/m² (25% CI 23.9-25.0; range 17.0-26.0). The absolute body weight increased by 13.8 kg (95% CI 13.2-1.5; range 3-38). A total of 24 patients (7.4%) reported new knee problems during pregnancy. 2 patients reported an increase in knee-related problems during pregnancy (0.6%). The incidence of knee-related problems (new cases and increase of problems n=26) was 26/326 or 7.6/100 pregnancies. In patients without knee problems, the pregnancy-related increase in the BMI (ΔBMI) was 4.8 kg/m² (95% CI 4.6-5.1, range 1.1-14.1). In cases with incident knee problems, the ΔBMI was 5.9 kg/m² (95% CI 4.9-6.9, range 2.1-11.8). The increase in body weight (Δbody weight) in patients without knee problems was 13.5 kg (95% CI 12.9-14.2, range 3-38). Patients with incident knee pain experienced a Δbody weight of 16.8 kg (95% CI 13.9-19.4, range 6-35). The differences in ΔBMI and Δbody weight were significant (p=0.009). A Δbody weight >20 kg was a significant risk factor for pregnancy-related knee pain significant risk factor pregnancy

  4. An analytically solvable three-body break-up model problem in hyperspherical coordinates

    NASA Astrophysics Data System (ADS)

    Ancarani, L. U.; Gasaneo, G.; Mitnik, D. M.

    2012-10-01

    An analytically solvable S-wave model for three particles break-up processes is presented. The scattering process is represented by a non-homogeneous Coulombic Schrödinger equation where the driven term is given by a Coulomb-like interaction multiplied by the product of a continuum wave function and a bound state in the particles coordinates. The closed form solution is derived in hyperspherical coordinates leading to an analytic expression for the associated scattering transition amplitude. The proposed scattering model contains most of the difficulties encountered in real three-body scattering problem, e.g., non-separability in the electrons' spherical coordinates and Coulombic asymptotic behavior. Since the coordinates' coupling is completely different, the model provides an alternative test to that given by the Temkin-Poet model. The knowledge of the analytic solution provides an interesting benchmark to test numerical methods dealing with the double continuum, in particular in the asymptotic regions. An hyperspherical Sturmian approach recently developed for three-body collisional problems is used to reproduce to high accuracy the analytical results. In addition to this, we generalized the model generating an approximate wave function possessing the correct radial asymptotic behavior corresponding to an S-wave three-body Coulomb problem. The model allows us to explore the typical structure of the solution of a three-body driven equation, to identify three regions (the driven, the Coulombic and the asymptotic), and to analyze how far one has to go to extract the transition amplitude.

  5. Energy analysis in the elliptic restricted three-body problem

    NASA Astrophysics Data System (ADS)

    Qi, Yi; de Ruiter, Anton

    2018-07-01

    The gravity assist or flyby is investigated by analysing the inertial energy of a test particle in the elliptic restricted three-body problem (ERTBP), where two primary bodies are moving in elliptic orbits. First, the expression of the derivation of energy is obtained and discussed. Then, the approximate expressions of energy change in a circular neighbourhood 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.

  6. Energy Analysis in the Elliptic Restricted Three-body Problem

    NASA Astrophysics Data System (ADS)

    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.

  7. Assessment of a Problem Posing Task in a Jamaican Grade Four Mathematics Classroom

    ERIC Educational Resources Information Center

    Munroe, Kayan Lloyd

    2016-01-01

    This paper analyzes how a teacher of mathematics used problem posing in the assessment of the cognitive development of 26 students at the grade-four level. The students, ages 8 to 10 years, were from a rural elementary school in western Jamaica. Using a picture as a prompt, students were asked to generate three arithmetic problems and to offer…

  8. Tethered body problems and relative motion orbit determination

    NASA Technical Reports Server (NTRS)

    Eades, J. B., Jr.; Wolf, H.

    1972-01-01

    Selected problems dealing with orbiting tethered body systems have been studied. In addition, a relative motion orbit determination program was developed. Results from these tasks are described and discussed. The expected tethered body motions were examined, analytically, to ascertain what influence would be played by the physical parameters of the tether, the gravity gradient and orbit eccentricity. After separating the motion modes these influences were determined; and, subsequently, the effects of oscillations and/or rotations, on tether force, were described. A study was undertaken, by examining tether motions, to see what type of control actions would be needed to accurately place a mass particle at a prescribed position relative to a main vehicle. Other applications for tethers were studied. Principally these were concerned with the producing of low-level gee forces by means of stabilized tether configurations; and, the initiation of free transfer trajectories from tether supported vehicle relative positions.

  9. Connecting orbits and invariant manifolds in the spatial restricted three-body problem

    NASA Astrophysics Data System (ADS)

    Gómez, G.; Koon, W. S.; Lo, M. W.; Marsden, J. E.; Masdemont, J.; Ross, S. D.

    2004-09-01

    The invariant manifold structures of the collinear libration points for the restricted three-body problem provide the framework for understanding transport phenomena from a geometrical point of view. In particular, the stable and unstable invariant manifold tubes associated with libration point orbits are the phase space conduits transporting material between primary bodies for separate three-body systems. These tubes can be used to construct new spacecraft trajectories, such as a 'Petit Grand Tour' of the moons of Jupiter. Previous work focused on the planar circular restricted three-body problem. This work extends the results to the three-dimensional case. Besides providing a full description of different kinds of libration motions in a large vicinity of these points, this paper numerically demonstrates the existence of heteroclinic connections between pairs of libration orbits, one around the libration point L1 and the other around L2. Since these connections are asymptotic orbits, no manoeuvre is needed to perform the transfer from one libration point orbit to the other. A knowledge of these orbits can be very useful in the design of missions such as the Genesis Discovery Mission, and may provide the backbone for other interesting orbits in the future.

  10. Comparison of four approaches to a rock facies classification problem

    USGS Publications Warehouse

    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.

  11. Light {xi} hypernuclei in four-body cluster models

    DOE Office of Scientific and Technical Information (OSTI.GOV)

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

    Detailed structure calculations in {sub {xi}{sup -}}{sup 12}Be, {sub {xi}{sup -}}{sup 5}H, {sub {xi}{sup -}}{sup 9}Li, {sub {xi}{sup -}}{sup 7}H, and {sub {xi}{sup -}}{sup 10}Li are performed within the framework of the microscopic two-, three-, and four-body cluster models using the Gaussian expansion method. We adopted effective {xi}N interactions derived from the Nijmegen interaction models, which give rise to substantially attractive {xi}-nucleus potentials in accordance with the experimental indications. {sub {xi}{sup -}}{sup 7}H and {sub {xi}{sup -}}{sup 10}Li are predicted to have bound states. we propose to observe the bound states in future (K{sup -},K{sup +}) experiments using {sup 7}Limore » and {sup 10}B targets in addition to the standard {sup 12}C target. The experimental confirmation of these states will provide information on the spin- and isospin-averaged {xi}N interaction.« less

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

    NASA Astrophysics Data System (ADS)

    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.

  13. New periodic solutions for some planar N + 3-body problems with Newtonian potentials

    NASA Astrophysics Data System (ADS)

    Yuan, Pengfei; Zhang, Shiqing

    2018-03-01

    For some planar Newtonian N + 3-body problems, we use variational minimization methods to prove the existence of new periodic solutions satisfying that N bodies chase each other on a curve, and the other 3 bodies chase each other on another curve. From the definition of orbit spaces in our paper, we can find that they are new solutions which are also different from all the examples of Ferrario and Terracini (2004).

  14. Use of various versions of Schwarz method for solving the problem of contact interaction of elastic bodies

    NASA Astrophysics Data System (ADS)

    Galanin, M. P.; Lukin, V. V.; Rodin, A. S.

    2018-04-01

    A definition of a sufficiently common problem of mechanical contact interaction in a system of elastic bodies is given. Various versions of realization of the Schwarz method for solving the contact problem numerically are described and the results of solution of a number of problems are presented. Special attention is paid to calculations where the grids in the bodies significantly differ in steps.

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

    NASA Astrophysics Data System (ADS)

    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.

  16. Genuine four tangle for four qubit states

    DOE Office of Scientific and Technical Information (OSTI.GOV)

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

    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.

  17. Solving the quantum many-body problem with artificial neural networks

    NASA Astrophysics Data System (ADS)

    Carleo, Giuseppe; Troyer, Matthias

    2017-02-01

    The challenge posed by the many-body problem in quantum physics originates from the difficulty of describing the nontrivial correlations encoded in the exponential complexity of the many-body wave function. Here we demonstrate that systematic machine learning of the wave function can reduce this complexity to a tractable computational form for some notable cases of physical interest. We introduce a variational representation of quantum states based on artificial neural networks with a variable number of hidden neurons. A reinforcement-learning scheme we demonstrate is capable of both finding the ground state and describing the unitary time evolution of complex interacting quantum systems. Our approach achieves high accuracy in describing prototypical interacting spins models in one and two dimensions.

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

    NASA Astrophysics Data System (ADS)

    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.

  19. Back disorders and health problems among subway train operators exposed to whole-body vibration.

    PubMed

    Johanning, E

    1991-12-01

    Back disease associated with whole-body vibration has not been evaluated for subway train operators. A recent study demonstrated that this group is exposed to whole-body vibration at levels above the international standard. To investigate this risk further, a self-administered questionnaire survey was conducted among subway train operators (N = 492) and a similar reference group (N = 92). The operators had a higher prevalence than the referents in all aspects of back problems, particularly for cervical and lower back pain. In a multiple logistic regression model, the odds ratio for sciatic pain among subway train operators was 3.9 (95% CI 1.7-8.6); the operators also had a higher risk of hearing-related problems (odds ratio 3.2, 95% CI 0.6-17.4) and of gastrointestinal problems (odds ratio 1.6, 95% CI 1.1-2.5). Although a cumulative dose-response relationship could not be statistically demonstrated, the findings appear to be related to exposure to whole-body vibration and inadequate ergonomic conditions.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    DOE PAGES

    Jia, C. J.; Wang, Y.; Mendl, C. B.; ...

    2017-12-02

    Here, 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 matrixmore » 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.« less

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jia, C. J.; Wang, Y.; Mendl, C. B.

    Here, 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 matrixmore » 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.« less

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

    USGS Publications Warehouse

    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.

  4. Form and performance: body shape and prey-capture success in four drift-feeding minnows

    Treesearch

    Pedro A. Rincón; Markus Bastir; Gary D. Grossman

    2008-01-01

    Identifying links between morphology and performance for ecologically relevant tasks will help elucidate the relationships between organismal design and fitness. We conducted a laboratory study to quantify the relationship between variation in body shape and prey-capture success in four drift-feeding minnow species. We offered drifting prey to individual fish in a test...

  5. Dynamical model of binary asteroid systems through patched three-body problems

    NASA Astrophysics Data System (ADS)

    Ferrari, Fabio; Lavagna, Michèle; Howell, Kathleen C.

    2016-08-01

    The paper presents a strategy for trajectory design in the proximity of a binary asteroid pair. A novel patched approach has been used to design trajectories in the binary system, which is modeled by means of two different three-body systems. The model introduces some degrees of freedom with respect to a classical two-body approach and it is intended to model to higher accuracy the peculiar dynamical properties of such irregular and low gravity field bodies, while keeping the advantages of having a full analytical formulation and low computational cost required. The neighborhood of the asteroid couple is split into two regions of influence where two different three-body problems describe the dynamics of the spacecraft. These regions have been identified by introducing the concept of surface of equivalence (SOE), a three-dimensional surface that serves as boundary between the regions of influence of each dynamical model. A case of study is presented, in terms of potential scenario that may benefit of such an approach in solving its mission analysis. Cost-effective solutions to land a vehicle on the surface of a low gravity body are selected by generating Poincaré maps on the SOE, seeking intersections between stable and unstable manifolds of the two patched three-body systems.

  6. The psychological four-color mapping problem.

    PubMed

    Francis, Gregory; Bias, Keri; Shive, Joshua

    2010-06-01

    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 of identifying the optimal colors for a map. We parameterized the model with a set of 7 colors using a visual search experiment in which human participants found a target region on a small map. We then used the model to predict search times for new maps and identified the color assignments that minimize or maximize average search time. The differences between these maps were predicted to be substantial. The model was then tested with a larger set of 31 colors on a map of English counties under conditions in which participants might memorize some aspects of the map. Empirical tests of the model showed that an optimally best colored version of this map is searched 15% faster than the correspondingly worst colored map. Thus, the color assignment seems to affect search times in a way predicted by the model, and this effect persists even when participants might use other sources of knowledge about target location. PsycINFO Database Record (c) 2010 APA, all rights reserved.

  7. Existence of liouvillian solutions in the problem of motion of a rotationally symmetric body on a sphere

    NASA Astrophysics Data System (ADS)

    Kuleshov, Alexander S.; Katasonova, Vera A.

    2018-05-01

    The problem of rolling without slipping of a rotationally symmetric rigid body on a sphere is considered. The rolling body is assumed to be subjected to the forces, the resultant of which is directed from the center of mass G of the body to the center O of the sphere, and depends only on the distance between G and O. In this case the solution of this problem is reduced to solving the second order linear differential equation over the projection of the angular velocity of the body onto its axis of symmetry. Using the Kovacic algorithm we search for liouvillian solutions of the corresponding second order differential equation in the case, when the rolling body is a dynamically symmetric ball.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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

  11. Syrian Civil-War-Related Intraocular Foreign Body Injuries: A Four-Year Retrospective Analysis.

    PubMed

    Gurler, Bulent; Coskun, Erol; Oner, Veysi; Comez, Aysegul; Erbagci, Ibrahim

    2017-01-01

    To analyze the data of patients who underwent vitreoretinal surgery due to intraocular foreign body (IOFB) injuries that occurred in the Syrian civil war. Seventy-eight eyes of 78 patients who underwent vitreoretinal surgery due to IOFB injuries that occurred during the Syrian civil war were analyzed. Forty-four eyes (56.4%) had traumatic cataract, 44 (56.4%) had retinal tears, 42 (53.8%) had vitreous hemorrhage, 18 (23%) had retinal detachment, 12 (15.3%) had endophthalmitis, and eight eyes had hyphema (10.2%). IOFBs consisted of metal in 62 eyes (79.4%), stone in eight eyes (10.2%), organic material in four eyes (5.1%), and glass in four eyes (5.1%). Approximately 86% of the eyes had initial VAs of 4/200 or worse. However, VAs improved in 64 eyes (82%) after the surgeries. Despite delays in treatment and the severity of injuries, 82% (64/78) of the eyes had an improvement in VA after the surgeries.

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

    NASA Astrophysics Data System (ADS)

    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.

  13. The nonequilibrium quantum many-body problem as a paradigm for extreme data science

    NASA Astrophysics Data System (ADS)

    Freericks, J. K.; Nikolić, B. K.; Frieder, O.

    2014-12-01

    Generating big data pervades much of physics. But some problems, which we call extreme data problems, are too large to be treated within big data science. The nonequilibrium quantum many-body problem on a lattice is just such a problem, where the Hilbert space grows exponentially with system size and rapidly becomes too large to fit on any computer (and can be effectively thought of as an infinite-sized data set). Nevertheless, much progress has been made with computational methods on this problem, which serve as a paradigm for how one can approach and attack extreme data problems. In addition, viewing these physics problems from a computer-science perspective leads to new approaches that can be tried to solve more accurately and for longer times. We review a number of these different ideas here.

  14. The development of spheroidal bodies theory for proto-planetary dynamics problem solving

    NASA Astrophysics Data System (ADS)

    Krot, A. M.

    2007-08-01

    There is not a full statistical equilibrium in a gas-dust proto-planetary cloud because of long relaxation time for proto-planet formation in own gravitational field. This protoplanetary system behavior can be described by Jeans equation in partial derivations relatively a distribution function. The problem for finding a general solution of Jeans equation is connected directly with an analytical expression for potential of gravitational field. Thus, the determination of gravitational potential is the main problem of statistical dynamics for proto-planetary system. The work shows this task of protoplanetary dynamics can be solved on the basis of spheroidal bodies theory [1]-[4]. Within the framework of this theory, cosmological bodies have fuzzy outlines and are represented by means of spheroidal forms. The proposed theory follows from the conception for forming a spheroidal body as a proto-planet from dust-like nebula; it permits to derive the form of distribution functions for an immovable spheroidal body [1],[2] and rotating one [3],[4] as well as their density masses (gravitational potentials and strengths) and also to find the distribution function of specific angular momentum for the rotating spheroidal body [4]. References: [1] A.M.Krot, Achievement in Modern Radioelectronics, 1996, no.8, pp.66-81 (in Russian). [2] A.M.Krot, Proc. SPIE's 13thAnnual Intern.Symp. "AeroSense", Orlando, Florida, USA, 1999, vol.3710, pp.1248-1259. [3] A.M.Krot, Proc. 35th COSPAR Scientific Assembly, Paris, France, 2004, Abstract A-00162. [4] A.Krot, Proc. EGU General Assembly, Vienna, Austria, 2006, Geophys. Res. Abstracts, vol.8, A-00216; SRef-ID: 1607-7962/gra/.

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

    PubMed

    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.

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    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 themore » 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.« less

  17. Artificial equilibrium points for a generalized sail in the elliptic restricted three-body problem

    NASA Astrophysics Data System (ADS)

    Aliasi, Generoso; Mengali, Giovanni; Quarta, Alessandro A.

    2012-10-01

    Different types of propulsion systems with continuous and purely radial thrust, whose modulus depends on the distance from a massive body, may be conveniently described within a single mathematical model by means of the concept of generalized sail. This paper discusses the existence and stability of artificial equilibrium points maintained by a generalized sail within an elliptic restricted three-body problem. Similar to the classical case in the absence of thrust, a generalized sail guarantees the existence of equilibrium points belonging only to the orbital plane of the two primaries. The geometrical loci of existing artificial equilibrium points are shown to coincide with those obtained for the circular three body problem when a non-uniformly rotating and pulsating coordinate system is chosen to describe the spacecraft motion. However, the generalized sail has to provide a periodically variable acceleration to maintain a given artificial equilibrium point. A linear stability analysis of the artificial equilibrium points is provided by means of the Floquet theory.

  18. Robe's restricted problem of 2+2 bodies when the bigger primary is a Roche ellipsoid and the smaller primary is an oblate body

    NASA Astrophysics Data System (ADS)

    Kaur, Bhavneet; Aggarwal, Rajiv

    2014-01-01

    In this problem, one of the primaries of mass m 1 is a Roche ellipsoid filled with a homogeneous incompressible fluid of density ρ 1. The smaller primary of mass m 2 is an oblate body outside the Ellipsoid. 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 motions of m 1 and m 2 but are influenced by them. We have extended the Robe's restricted three-body problem to 2+2 body problem under the assumption that the fluid body assumes the shape of the Roche ellipsoid (Chandrashekhar in Ellipsoidal figures of equilibrium, Chap. 8, Dover, New York, 1987). 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. We have proved that there exist only six equilibrium solutions of the system, provided they lie within the Roche ellipsoid. In a system where the primaries are considered as Earth-Moon and m 3, m 4 as submarines, the equilibrium solutions of m 3 and m 4 respectively when the displacement is given in the direction of x 1-axis or x 2-axis are unstable.

  19. Resonance transition periodic orbits in the circular restricted three-body problem

    NASA Astrophysics Data System (ADS)

    Lei, Hanlun; Xu, Bo

    2018-04-01

    This work studies a special type of cislunar periodic orbits in the circular restricted three-body problem called resonance transition periodic orbits, which switch between different resonances and revolve about the secondary with multiple loops during one period. In the practical computation, families of multiple periodic orbits are identified first, and then the invariant manifolds emanating from the unstable multiple periodic orbits are taken to generate resonant homoclinic connections, which are used to determine the initial guesses for computing the desired periodic orbits by means of multiple-shooting scheme. The obtained periodic orbits have potential applications for the missions requiring long-term continuous observation of the secondary and tour missions in a multi-body environment.

  20. All-atom four-body knowledge-based statistical potential to distinguish native tertiary RNA structures from nonnative folds.

    PubMed

    Masso, Majid

    2018-09-14

    Scientific breakthroughs in recent decades have uncovered the capability of RNA molecules to fulfill a wide array of structural, functional, and regulatory roles in living cells, leading to a concomitantly significant increase in both the number and diversity of experimentally determined RNA three-dimensional (3D) structures. Atomic coordinates from a representative training set of solved RNA structures, displaying low sequence and structure similarity, facilitate derivation of knowledge-based energy functions. Here we develop an all-atom four-body statistical potential and evaluate its capacity to distinguish native RNA 3D structures from nonnative folds based on calculated free energy scores. Atomic four-body nearest-neighbors are objectively identified by their occurrence as tetrahedral vertices in the Delaunay tessellations of RNA structures, and rates of atomic quadruplet interactions expected by chance are obtained from a multinomial reference distribution. Our four-body energy function, referred to as RAMP (ribonucleic acids multibody potential), is subsequently derived by applying the inverted Boltzmann principle to the frequency data, yielding an energy score for each type of atomic quadruplet interaction. Several well-known benchmark datasets reveal that RAMP is comparable with, and often outperforms, existing knowledge- and physics-based energy functions. To the best of our knowledge, this is the first study detailing an RNA tertiary structure-based multibody statistical potential and its comparative evaluation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Solving a four-destination traveling salesman problem using Escherichia coli cells as biocomputers.

    PubMed

    Esau, Michael; Rozema, Mark; Zhang, Tuo Huang; Zeng, Dawson; Chiu, Stephanie; Kwan, Rachel; Moorhouse, Cadence; Murray, Cameron; Tseng, Nien-Tsu; Ridgway, Doug; Sauvageau, Dominic; Ellison, Michael

    2014-12-19

    The Traveling Salesman Problem involves finding the shortest possible route visiting all destinations on a map only once before returning to the point of origin. The present study demonstrates a strategy for solving Traveling Salesman Problems using modified E. coli cells as processors for massively parallel computing. Sequential, combinatorial DNA assembly was used to generate routes, in the form of plasmids made up of marker genes, each representing a path between destinations, and short connecting linkers, each representing a given destination. Upon growth of the population of modified E. coli, phenotypic selection was used to eliminate invalid routes, and statistical analysis was performed to successfully identify the optimal solution. The strategy was successfully employed to solve a four-destination test problem.

  2. Numerical integration of the N-body ring problem by recurrent power series

    NASA Astrophysics Data System (ADS)

    Navarro, Juan F.

    2018-02-01

    The aim of this article is to present a method for the integration of the equations of motion of the N-body ring problem by means of recurrent power series. We prove that the solution is convergent for any set of initial conditions, excluding those corresponding to binary collisions.

  3. Solving the Quantum Many-Body Problem via Correlations Measured with a Momentum Microscope

    NASA Astrophysics Data System (ADS)

    Hodgman, S. S.; Khakimov, R. I.; Lewis-Swan, R. J.; Truscott, A. G.; Kheruntsyan, K. V.

    2017-06-01

    In quantum many-body theory, all physical observables are described in terms of correlation functions between particle creation or annihilation operators. Measurement of such correlation functions can therefore be regarded as an operational solution to the quantum many-body problem. Here, we demonstrate this paradigm by measuring multiparticle momentum correlations up to third order between ultracold helium atoms in an s -wave scattering halo of colliding Bose-Einstein condensates, using a quantum many-body momentum microscope. Our measurements allow us to extract a key building block of all higher-order correlations in this system—the pairing field amplitude. In addition, we demonstrate a record violation of the classical Cauchy-Schwarz inequality for correlated atom pairs and triples. Measuring multiparticle momentum correlations could provide new insights into effects such as unconventional superconductivity and many-body localization.

  4. Computational nuclear quantum many-body problem: The UNEDF project

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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.

  6. Calculation of Water Entry Problem for Free-falling Bodies Using a Developed Cartesian Cut Cell Mesh

    NASA Astrophysics Data System (ADS)

    Wenhua, Wang; Yanying, Wang

    2010-05-01

    This paper describes the development of free surface capturing method on Cartesian cut cell mesh to water entry problem for free-falling bodies with body-fluid interaction. The incompressible Euler equations for a variable density fluid system are presented as governing equations and the free surface is treated as a contact discontinuity by using free surface capturing method. In order to be convenient for dealing with the problem with moving body boundary, the Cartesian cut cell technique is adopted for generating the boundary-fitted mesh around body edge by cutting solid regions out of a background Cartesian mesh. Based on this mesh system, governing equations are discretized by finite volume method, and at each cell edge inviscid flux is evaluated by means of Roe's approximate Riemann solver. Furthermore, for unsteady calculation in time domain, a time accurate solution is achieved by a dual time-stepping technique with artificial compressibility method. For the body-fluid interaction, the projection method of momentum equations and exact Riemann solution are applied in the calculation of fluid pressure on the solid boundary. Finally, the method is validated by test case of water entry for free-falling bodies.

  7. On the stability of the solutions of the general problem of three bodies

    NASA Technical Reports Server (NTRS)

    Standish, E. M., Jr.

    1976-01-01

    The extent through which the initial conditions of a given three-body system may be varied without completely changing the qualitative nature of the subsequent system evolution is investigated. It is assumed that the three masses are equal, all initial velocities are zero, the first two bodies initially lie on the x-axis, and the position of the third body is confined to a specific region of space. Analysis of the system evolution for different initial positions of the third body shows that there is a whole area or 'island' in the x-y plane throughout which the initial position of the third body may be moved in a continuous fashion to produce an evolution which also changes in a continuous manner. A Monte Carlo approach is adopted to determine the full extent of this island in the general problem. It is concluded that the stability of a full solution may be directly related to the size of its island in phase space.

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

    ERIC Educational Resources Information Center

    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,…

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

    NASA Astrophysics Data System (ADS)

    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.

  10. Many-Body Effects in the Mesoscopic x-Ray Edge Problem

    NASA Astrophysics Data System (ADS)

    Hentschel, M.; R"Oder, G.; Ullmo, D.

    Many-body phenomena, a key interest in the investigation ofbulk 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 excition 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-Nozières-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.

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

    NASA Astrophysics Data System (ADS)

    Golse, François

    2018-04-01

    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'.

  12. Foreign Body in the Vagina of A Four-Year-Old-Girl: A Childish Prank or Sexual Abuse

    PubMed Central

    Sakhavar, Nahid; Teimoori, Batool; Ghasemi, Marzie

    2014-01-01

    Introduction: Foreign body in the vagina is a common cause of vaginal discharge, which may be either purulent or hemorrhagic. Case Presentation: 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. Conclusions: 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. PMID:25032156

  13. [Estimation of body fat by DXA and the four compartment model in Mexican youth].

    PubMed

    Ramírez, Erik; Valencia, Mauro E; Moya Camarena, Silvia Y; Alemán-Mateo, Heliodoro; Méndez, Rosa O

    2010-09-01

    The objective of this study was to validate the estimation of body fat (%BF) by DXA (Dual-Energy X-Ray AbsorciomDPX-MD) against the four compartment model (4C) of body composition in 32 Mexican pubertal girls and boys (aged 9-14 y; F=16). The mean of the difference between DXA and 4C model was -3.5 %BF (p=0.171). The limits of agreement (95% = 2 SD) were +5% to -12%BF. The precision of estimated limits of y the confidence intervals were -1.9% to -5.1%BF (P = 0.050). The concordance correlation coefficient was p = 0.85. The test of accuracy for coincidence of slop intercepts between DXA and the 4C model showed no coincidence (p < 0.05). The precision by R2 explained 83% of the variance (SEE, 4.1%). The individual accuracy assess by the total error was 5.6%. The group mean accuracy by two way analysis of variance of body fat did not show interaction between method (DXA-4C model) and separate analysis of gender and overweight. However, there was an effect of method (p = 0.043) in the presence of overweight (p < 0.001). In conclusion, the estimation of percent of body fat by DXA was not precise and accurate in a group of Mexican children. However, results do not limit the utility of DXA for the measurements of body composition and its relation with health outcomes, especially in follow up studies.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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 <1000 g at birth) has led to concern about their behavioural outcome in childhood. In reports from several countries with different assessments at various ages, investigators have noted a higher frequency of behavioural problems in such infants, but cross-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.

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

    PubMed

    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.

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

    PubMed Central

    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

  18. On the n-body problem on surfaces of revolution

    NASA Astrophysics Data System (ADS)

    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.

  19. Moving Bodies, Building Minds: Foster Preschoolers' Critical Thinking and Problem Solving through Movement

    ERIC Educational Resources Information Center

    Marigliano, Michelle L.; Russo, Michele J.

    2011-01-01

    Creative movement is an ideal way to help young children develop critical-thinking and problem-solving skills. Most young children are, by nature, extremely physical. They delight in exploring the world with their bodies and expressing their ideas and feelings through movement. During creative movement experiences, children learn to think before…

  20. Gambling and problem gambling among recently sentenced male prisoners in four New Zealand prisons.

    PubMed

    Abbott, Max W; McKenna, Brian G; Giles, Lynne C

    2005-01-01

    Recently sentenced inmates in four New Zealand male prisons (N = 357) were interviewed to assess their gambling involvement, problem gambling and criminal offending. Frequent participation in and high expenditure on continuous forms of gambling prior to imprisonment were reported. Nineteen percent said they had been in prison for a gambling-related offence and most of this offending was property-related and non-violent. On the basis of their SOGS-R scores, 21% were lifetime probable pathological gamblers and 16% were probable pathological gamblers during the six months prior to imprisonment. Of the "current" problem gamblers, 51% reported gambling-related offending and 35% had been imprisoned for a crime of this type. Gambling-related offending increased with problem gambling severity. However, only five percent of problem gamblers said their early offending was gambling-related. The large majority reported other types of offending at this time. Few men had sought or received help for gambling problems prior to imprisonment or during their present incarceration. This highlights the potential for assessment and treatment programs in prison to reduce recidivism and adverse effects of problem gambling and gambling-related offending.

  1. Tails and bridges in the parabolic restricted three-body problem

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

  4. f and g series solutions to a post-Newtonian two-body problem with parameters β and γ

    NASA Astrophysics Data System (ADS)

    Qin, Song-He; Liu, Jing-Xi; Zhong, Ze-Hao; Xie, Yi

    2016-01-01

    Classical Newtonian f and g series for a Keplerian two-body problem are extended for the case of a post-Newtonian two-body problem with parameters β and γ. These two parameters are introduced to parameterize the post-Newtonian approximation of alternative theories of gravity and they are both equal to 1 in general relativity. Up to the order of 30, we obtain all of the coefficients of the series in their exact forms without any cutoff for significant figures. The f and g series for the post-Newtonian two-body problem are also compared with a Runge-Kutta order 7 integrator. Although the f and g series have no superiority in terms of accuracy or efficiency at the order of 7, the discrepancy in the performances of these two methods is not quite distinct. However, the f and g series have the advantage of flexibility for going to higher orders. Some examples of relativistic advance of periastron are given and the effect of gravitational radiation on the scheme of f and g series is evaluated.

  5. Broad Search for Unstable Resonant Orbits in the Planar Circular Restricted Three-Body Problem

    NASA Technical Reports Server (NTRS)

    Anderson, Rodney L.; Campagnola, Stefano; Lantoine, Gregory

    2013-01-01

    Unstable resonant orbits in the circular restricted three-body problem have increasingly been used for trajectory design using optimization and invariant manifold techniques.In this study, several methods for computing these unstable resonant orbits are explored including flyby maps, continuation from two-body models, and grid searches. Families of orbits are computed focusing on the Jupiter-Europa system, and their characteristics are explored. Different parameters such as period and stability are examined for each set of resonantor bits, and the continuation of several specific orbits is explored in more detail.

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

    NASA Astrophysics Data System (ADS)

    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.

  7. Two Body Wear of Newly Introduced Nanocomposite Teeth and Cross Linked Four Layered Acrylic Teeth: a Comparitive In Vitro Study.

    PubMed

    Ilangkumaran, R; Srinivasan, J; Baburajan, K; Balaji, N

    2014-12-01

    Wear of complete denture teeth results in compromise in denture esthetics and functions. To counteract this problem, artificial teeth with increased wear resistance had been introduced in the market such as nanocomposite teeth. The purpose of this study was to compare the amount of wear between nanocomposite teeth and acrylic teeth. Fifteen specimens were chosen from each group namely the nanocomposite teeth (SR_-PHONARES) and the acrylic teeth (ACRY PLUS). Maxillary premolar was only chosen for testing and the samples were customized according to the specifications of the pin on disc machine. Pin on disc machine is a two body tribometer which quantifies the amount of wear under a specific load and time. Test samples were mounted on to the receptacle of the pin on disc machine and tested under a load of 0.3 kg for 1,000 cycles of rotation against a 600 grit emery paper. The amount of wear is displayed from the digital reading obtained from the pin on disc machine. After statistical analysis, it was found that, the amount of wear is more in four layered acrylic teeth. The p value obtained is 0.002 (<0.005) thus implies that the difference in wear between nanocomposite teeth and acrylic teeth is statistically significant. Though the nanocomposite teeth has less amount of wear than the four layered acrylic teeth, the difference is very less and adds only to a little clinical significance but the cost of the nanocomposite is four times that of the acrylic teeth. Further clinical studies must be performed to confirm our results.

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Understanding of Macroscopic, Microscopic and Symbolic Representations among Form Four Students in Solving Stoichiometric Problems

    ERIC Educational Resources Information Center

    Sujak, Kamariah Binti; Daniel, Esther Gnanamalar Sarojini

    2017-01-01

    The purpose of this article is to determine the levels of understanding for solving Stoichiometry problems from the aspect of macroscopic, microscopic and symbolic representations of high, average and low achieving students after infusion of metacognitive skills. Nine form four students aged sixteen years old from a secondary school in Kuala…

  10. Health behaviour and body mass index among problem gamblers: results from a nationwide survey.

    PubMed

    Algren, Maria H; Ekholm, Ola; Davidsen, Michael; Larsen, Christina V L; Juel, Knud

    2015-06-01

    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 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 behaviour and obesity. The odds of smoking was significantly higher among problem gamblers than among non-problem gamblers. Further, the odds of high-risk alcohol drinking and illicit drug use were significantly higher among problem gamblers. The prevalence of sedentary leisure activity, unhealthy diet 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 challenge and elucidate the need for health promotion initiatives targeted at problem gamblers. Furthermore, more research is needed in order to understand the underlying social mechanism of the association between problem gamblers and unhealthy behaviour.

  11. Analytic Solution of the Problem of Additive Formation of an Inhomogeneous Elastic Spherical Body in an Arbitrary Nonstationary Central Force Field

    NASA Astrophysics Data System (ADS)

    Parshin, D. A.

    2017-09-01

    We study the processes of additive formation of spherically shaped rigid bodies due to the uniform accretion of additional matter to their surface in an arbitrary centrally symmetric force field. A special case of such a field can be the gravitational or electrostatic force field. We consider the elastic deformation of the formed body. The body is assumed to be isotropic with elasticmoduli arbitrarily varying along the radial coordinate.We assume that arbitrary initial circular stresses can arise in the additional material added to the body in the process of its formation. In the framework of linear mechanics of growing bodies, the mathematical model of the processes under study is constructed in the quasistatic approximation. The boundary value problems describing the development of stress-strain state of the object under study before the beginning of the process and during the entire process of its formation are posed. The closed analytic solutions of the posed problems are constructed by quadratures for some general types of material inhomogeneity. Important typical characteristics of the mechanical behavior of spherical bodies additively formed in the central force field are revealed. These characteristics substantially distinguish such bodies from the already completely composed bodies similar in dimensions and properties which are placed in the force field and are described by problems of mechanics of deformable solids in the classical statement disregarding the mechanical aspects of additive processes.

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

    NASA Astrophysics Data System (ADS)

    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.

  13. SO(4) algebraic approach to the three-body bound state problem in two dimensions

    NASA Astrophysics Data System (ADS)

    Dmitrašinović, V.; Salom, Igor

    2014-08-01

    We use the permutation symmetric hyperspherical three-body variables to cast the non-relativistic three-body Schrödinger equation in two dimensions into a set of (possibly decoupled) differential equations that define an eigenvalue problem for the hyper-radial wave function depending on an SO(4) hyper-angular matrix element. We express this hyper-angular matrix element in terms of SO(3) group Clebsch-Gordan coefficients and use the latter's properties to derive selection rules for potentials with different dynamical/permutation symmetries. Three-body potentials acting on three identical particles may have different dynamical symmetries, in order of increasing symmetry, as follows: (1) S3 ⊗ OL(2), the permutation times rotational symmetry, that holds in sums of pairwise potentials, (2) O(2) ⊗ OL(2), the so-called "kinematic rotations" or "democracy symmetry" times rotational symmetry, that holds in area-dependent potentials, and (3) O(4) dynamical hyper-angular symmetry, that holds in hyper-radial three-body potentials. We show how the different residual dynamical symmetries of the non-relativistic three-body Hamiltonian lead to different degeneracies of certain states within O(4) multiplets.

  14. All-Atom Four-Body Knowledge-Based Statistical Potentials to Distinguish Native Protein Structures from Nonnative Folds

    PubMed Central

    2017-01-01

    Recent advances in understanding protein folding have benefitted from coarse-grained representations of protein structures. Empirical energy functions derived from these techniques occasionally succeed in distinguishing native structures from their corresponding ensembles of nonnative folds or decoys which display varying degrees of structural dissimilarity to the native proteins. Here we utilized atomic coordinates of single protein chains, comprising a large diverse training set, to develop and evaluate twelve all-atom four-body statistical potentials obtained by exploring alternative values for a pair of inherent parameters. Delaunay tessellation was performed on the atomic coordinates of each protein to objectively identify all quadruplets of interacting atoms, and atomic potentials were generated via statistical analysis of the data and implementation of the inverted Boltzmann principle. Our potentials were evaluated using benchmarking datasets from Decoys-‘R'-Us, and comparisons were made with twelve other physics- and knowledge-based potentials. Ranking 3rd, our best potential tied CHARMM19 and surpassed AMBER force field potentials. We illustrate how a generalized version of our potential can be used to empirically calculate binding energies for target-ligand complexes, using HIV-1 protease-inhibitor complexes for a practical application. The combined results suggest an accurate and efficient atomic four-body statistical potential for protein structure prediction and assessment. PMID:29119109

  15. 9Be+120Sn scattering at near-barrier energies within a four-body model

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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.

  17. The effect of tidal forces on the minimum energy configurations of the full three-body problem

    NASA Astrophysics Data System (ADS)

    Levine, Edward

    We investigate the evolution of minimum energy configurations for the Full Three Body Problem (3BP). A stable ternary asteroid system will gradually become unstable due to the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect and an unpredictable trajectory will ensue. Through the interaction of tidal torques, energy in the system will dissipate in the form of heat until a stable minimum energy configuration is reached. We present a simulation that describes the dynamical evolution of three bodies under the mutual effects of gravity and tidal torques. Simulations show that bodies do not get stuck in local minima and transition to the predicted minimum energy configuration.

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

    NASA Astrophysics Data System (ADS)

    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.

  19. Behavioural and emotional problems in Iranian children four years after parental death in an earthquake.

    PubMed

    Kalantari, M; Vostanis, P

    2010-03-01

    Although previous research has established a direct impact of natural disasters on child mental health, there is limited knowledge on the underpinning mechanisms, particularly when there has been the loss of a parent. To establish: (a) the rates of behavioural and emotional problems of school-aged children who had lost their parents in the 2003 earthquake in Iran, compared with children from intact families who attended the same schools; (b) the relationship between the psychopathology of the surviving parents' and children's behavioural and emotional problems; and (c) whether this relationship was compounded by socioeconomic factors. Eighty six children of 7-13 years who had lost a parent in the earthquake four years earlier were compared with 80 matched children from intact families. The teacher and parent versions of the Strengths and Difficulties Questionnaire (SDQ) were used as measures of behavioural and emotional problems. Parents' psychopathology was established by the Self Report Questionnaire (SRQ). Behavioural and emotional problems were significantly higher in children who had suffered parental loss than in the control group. There was a significant association between parent-rated SDQ and SRQ scores. Parental death was found to interact with socioeconomic variables in predicting children's behavioural and emotional problems and surviving parents' mental health problems. After natural disasters, bereaved children and their surviving parents are at risk of developing mental health problems, and social adversities increase this risk.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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 < 0.05) between the results of Scale 7 (Pt) and one's body acceptance (r = -0.44), attitude to eating (r = -0.3), femininity disclosure (r = -0.28)and the experience of intimate relations (r = -0.27). The study showed that disordered body image is related to the symptoms described by Scale 7 (Pt): tendency to react with fear, worriment, stronger discomfort in social situations, fear of rejection, difficulties in interpersonal relations, poor self-confidence as well as perfectionism and tensed behaviour. A crucial factor that could improve the effectiveness of therapies for women from alcoholic families appears to be an attempt to combine the experience of oneself in physical and emotional spheres, as well as functioning cognitive schemes.

  2. A stable partitioned FSI algorithm for rigid bodies and incompressible flow. Part I: Model problem analysis

    NASA Astrophysics Data System (ADS)

    Banks, J. W.; Henshaw, W. D.; Schwendeman, D. W.; Tang, Qi

    2017-08-01

    A stable partitioned algorithm is developed for fluid-structure interaction (FSI) problems involving viscous incompressible flow and rigid bodies. This added-mass partitioned (AMP) algorithm remains stable, without sub-iterations, for light and even zero mass rigid bodies when added-mass and viscous added-damping effects are large. The scheme is based on a generalized Robin interface condition for the fluid pressure that includes terms involving the linear acceleration and angular acceleration of the rigid body. Added-mass effects are handled in the Robin condition by inclusion of a boundary integral term that depends on the pressure. Added-damping effects due to the viscous shear forces on the body are treated by inclusion of added-damping tensors that are derived through a linearization of the integrals defining the force and torque. Added-damping effects may be important at low Reynolds number, or, for example, in the case of a rotating cylinder or rotating sphere when the rotational moments of inertia are small. In this first part of a two-part series, the properties of the AMP scheme are motivated and evaluated through the development and analysis of some model problems. The analysis shows when and why the traditional partitioned scheme becomes unstable due to either added-mass or added-damping effects. The analysis also identifies the proper form of the added-damping which depends on the discrete time-step and the grid-spacing normal to the rigid body. The results of the analysis are confirmed with numerical simulations that also demonstrate a second-order accurate implementation of the AMP scheme.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  5. Fast Multipole Methods for Three-Dimensional N-body Problems

    NASA Technical Reports Server (NTRS)

    Koumoutsakos, P.

    1995-01-01

    We are developing computational tools for the simulations of three-dimensional flows past bodies undergoing arbitrary motions. High resolution viscous vortex methods have been developed that allow for extended simulations of two-dimensional configurations such as vortex generators. Our objective is to extend this methodology to three dimensions and develop a robust computational scheme for the simulation of such flows. A fundamental issue in the use of vortex methods is the ability of employing efficiently large numbers of computational elements to resolve the large range of scales that exist in complex flows. The traditional cost of the method scales as Omicron (N(sup 2)) as the N computational elements/particles induce velocities at each other, making the method unacceptable for simulations involving more than a few tens of thousands of particles. In the last decade fast methods have been developed that have operation counts of Omicron (N log N) or Omicron (N) (referred to as BH and GR respectively) depending on the details of the algorithm. These methods are based on the observation that the effect of a cluster of particles at a certain distance may be approximated by a finite series expansion. In order to exploit this observation we need to decompose the element population spatially into clusters of particles and build a hierarchy of clusters (a tree data structure) - smaller neighboring clusters combine to form a cluster of the next size up in the hierarchy and so on. This hierarchy of clusters allows one to determine efficiently when the approximation is valid. This algorithm is an N-body solver that appears in many fields of engineering and science. Some examples of its diverse use are in astrophysics, molecular dynamics, micro-magnetics, boundary element simulations of electromagnetic problems, and computer animation. More recently these N-body solvers have been implemented and applied in simulations involving vortex methods. Koumoutsakos and Leonard (1995

  6. Regularization of the Perturbed Spatial Restricted Three-Body Problem by L-Transformations

    NASA Astrophysics Data System (ADS)

    Poleshchikov, S. M.

    2018-03-01

    Equations of motion for the perturbed circular restricted three-body problem have been regularized in canonical variables in a moving coordinate system. Two different L-matrices of the fourth order are used in the regularization. Conditions for generalized symplecticity of the constructed transform have been checked. In the unperturbed case, the regular equations have a polynomial structure. The regular equations have been numerically integrated using the Runge-Kutta-Fehlberg method. The results of numerical experiments are given for the Earth-Moon system parameters taking into account the perturbation of the Sun for different L-matrices.

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

    PubMed

    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.

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

    PubMed Central

    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

  9. Status of training programs and perceived labor problems in four types of noncommercial foodservice operations.

    PubMed

    Cluskey, M; Messersmith, A M

    1991-10-01

    Training is essential for the effective delivery of quality foodservice products. A well-developed training program is ongoing, comprehensive, planned in advance, and performance based. Such programs facilitate performance and may be beneficial to develop employees and reduce employee turnover rates. The purpose of this study was to investigate the kinds of training programs that are being developed and delivered to employees in noncommercial foodservice operations. A survey instrument was mailed nationally to foodservice directors and administrators in health care and educational foodservice operations requesting information about training programs used for their nonsupervisory foodservice employees. Information regarding perceived existence of potential labor problems was also collected. Relationships between training programs and perception of labor problems were investigated. Training appears to be conducted in some form within the four types of noncommercial foodservice operations investigated. The most severely perceived labor problems among nonsupervisory employees include low motivation, lack of skills, and poor promotability.

  10. On problems of analyzing aerodynamic properties of blunted rotary bodies with small random surface distortions under supersonic and hypersonic flows

    NASA Astrophysics Data System (ADS)

    Degtyar, V. G.; Kalashnikov, S. T.; Mokin, Yu. A.

    2017-10-01

    The paper considers problems of analyzing aerodynamic properties (ADP) of reenetry vehicles (RV) as blunted rotary bodies with small random surface distortions. The interactions of math simulation of surface distortions, selection of tools for predicting ADPs of shaped bodies, evaluation of different-type ADP variations and their adaptation for dynamic problems are analyzed. The possibilities of deterministic and probabilistic approaches to evaluation of ADP variations are considered. The practical value of the probabilistic approach is demonstrated. The examples of extremal deterministic evaluations of ADP variations for a sphere and a sharp cone are given.

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

    NASA Astrophysics Data System (ADS)

    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.

  12. Orbit period modulation for relative motion using continuous low thrust in the two-body and restricted three-body problems

    NASA Astrophysics Data System (ADS)

    Arnot, C. S.; McInnes, C. R.; McKay, R. J.; Macdonald, M.; Biggs, J.

    2018-02-01

    This paper presents rich new families of relative orbits for spacecraft formation flight generated through the application of continuous thrust with only minimal intervention into the dynamics of the problem. Such simplicity facilitates implementation for small, low-cost spacecraft with only position state feedback, and yet permits interesting and novel relative orbits in both two- and three-body systems with potential future applications in space-based interferometry, hyperspectral sensing, and on-orbit inspection. Position feedback is used to modify the natural frequencies of the linearised relative dynamics through direct manipulation of the system eigenvalues, producing new families of stable relative orbits. Specifically, in the Hill-Clohessy-Wiltshire frame, simple adaptations of the linearised dynamics are used to produce a circular relative orbit, frequency-modulated out-of-plane motion, and a novel doubly periodic cylindrical relative trajectory for the purposes of on-orbit inspection. Within the circular restricted three-body problem, a similar minimal approach with position feedback is used to generate new families of stable, frequency-modulated relative orbits in the vicinity of a Lagrange point, culminating in the derivation of the gain requirements for synchronisation of the in-plane and out-of-plane frequencies to yield a singly periodic tilted elliptical relative orbit with potential use as a Lunar far-side communications relay. The Δ v requirements for the cylindrical relative orbit and singly periodic Lagrange point orbit are analysed, and it is shown that these requirements are modest and feasible for existing low-thrust propulsion technology.

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

    PubMed

    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.

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

    PubMed

    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 (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.

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

    NASA Astrophysics Data System (ADS)

    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.

  16. Genome-wide association studies identified multiple genetic loci for body size at four growth stages in Chinese Holstein cattle.

    PubMed

    Zhang, Xu; Chu, Qin; Guo, Gang; Dong, Ganghui; Li, Xizhi; Zhang, Qin; Zhang, Shengli; Zhang, Zhiwu; Wang, Yachun

    2017-01-01

    The growth and maturity of cattle body size affect not only feed efficiency, but also productivity and longevity. Dissecting the genetic architecture of body size is critical for cattle breeding to improve both efficiency and productivity. The volume and weight of body size are indicated by several measurements. Among them, Heart Girth (HG) and Hip Height (HH) are the most important traits. They are widely used as predictors of body weight (BW). Few association studies have been conducted for HG and HH in cattle focusing on single growth stage. In this study, we extended the Genome-wide association studies to a full spectrum of four growth stages (6-, 12-, 18-, and 24-months after birth) in Chinese Holstein heifers. The whole genomic single nucleotide polymorphisms (SNPs) were obtained from the Illumina BovineSNP50 v2 BeadChip genotyped on 3,325 individuals. Estimated breeding values (EBVs) were derived for both HG and HH at the four different ages and analyzed separately for GWAS by using the Fixed and random model Circuitous Probability Unification (FarmCPU) method. In total, 27 SNPs were identified to be significantly associated with HG and HH at different growth stages. We found 66 candidate genes located nearby the associated SNPs, including nine genes that were known as highly related to development and skeletal and muscular growth. In addition, biological function analysis was performed by Ingenuity Pathway Analysis and an interaction network related to development was obtained, which contained 16 genes out of the 66 candidates. The set of putative genes provided valuable resources and can help elucidate the genomic architecture and mechanisms underlying growth traits in dairy cattle.

  17. Prognosis and Continuity of Child Mental Health Problems from Preschool to Primary School: Results of a Four-Year Longitudinal Study

    ERIC Educational Resources Information Center

    Beyer, Thomas; Postert, Christian; Muller, Jorg M.; Furniss, Tilman

    2012-01-01

    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…

  18. Four-body calculation of {sup 12}C(α, γ){sup 16}O radiative capture reaction at stellar energies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sadeghi, H., E-mail: H-Sadeghi@Araku.ac.ir; Firoozabadi, M. M.

    2016-01-15

    On the basis of the four-alphamodel, the {sup 12}C(α, γ){sup 16}Oradiative capture process is investigated by using the four-body Faddeev–Yakubovsky equations as well as the two- and three-body electromagnetic currents. The present calculation is an application of our current conservation realistic potentials method for the {sup 12}C(α, γ){sup 16}Oradiative capture process. This work clears the way formore refinedmodels of radiative capture based on two- and three-body realistic potentials and current conservation. The calculation is carried out by considering the {sup 4}He + {sup 12}C (1 + 3) and the {sup 8}Be + {sup 8}Be (2 + 2) subamplitudes, respectively. Radiativemore » capture {sup 12}C(α, γ){sup 16}Oreaction is one of the most important reactions in nuclear astrophysics. For this reaction, the electric dipole transitions between states with the same isospin are forbidden in the first order. Because the state 1{sup +} and 0{sup +} ground state nuclei {sup 16}O have zero isospin, thus the electric dipole radiations are not at the first order between two levels and electric dipole radiation will be the second order and electric dipole radiation is the same order as the electric quadrupole radiation. Therefore, we must consider the effects of both radiations. In comparison with other theoretical methods and available experimental data, good agreement is achieved for the E{sub 1} and E{sub 2} contribution to the cross section and the astrophysical S factor for this process.« less

  19. A stable partitioned FSI algorithm for rigid bodies and incompressible flow. Part I: Model problem analysis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Banks, J. W.; Henshaw, W. D.; Schwendeman, D. W.

    A stable partitioned algorithm is developed for fluid-structure interaction (FSI) problems involving viscous incompressible flow and rigid bodies. This added-mass partitioned (AMP) algorithm remains stable, without sub-iterations, for light and even zero mass rigid bodies when added-mass and viscous added-damping effects are large. The scheme is based on a generalized Robin interface condition for the fluid pressure that includes terms involving the linear acceleration and angular acceleration of the rigid body. Added mass effects are handled in the Robin condition by inclusion of a boundary integral term that depends on the pressure. Added-damping effects due to the viscous shear forcesmore » on the body are treated by inclusion of added-damping tensors that are derived through a linearization of the integrals defining the force and torque. Added-damping effects may be important at low Reynolds number, or, for example, in the case of a rotating cylinder or rotating sphere when the rotational moments of inertia are small. In this second part of a two-part series, the general formulation of the AMP scheme is presented including the form of the AMP interface conditions and added-damping tensors for general geometries. A fully second-order accurate implementation of the AMP scheme is developed in two dimensions based on a fractional-step method for the incompressible Navier-Stokes equations using finite difference methods and overlapping grids to handle the moving geometry. Here, the numerical scheme is verified on a number of difficult benchmark problems.« less

  20. A stable partitioned FSI algorithm for rigid bodies and incompressible flow. Part I: Model problem analysis

    DOE PAGES

    Banks, J. W.; Henshaw, W. D.; Schwendeman, D. W.; ...

    2017-01-20

    A stable partitioned algorithm is developed for fluid-structure interaction (FSI) problems involving viscous incompressible flow and rigid bodies. This added-mass partitioned (AMP) algorithm remains stable, without sub-iterations, for light and even zero mass rigid bodies when added-mass and viscous added-damping effects are large. The scheme is based on a generalized Robin interface condition for the fluid pressure that includes terms involving the linear acceleration and angular acceleration of the rigid body. Added mass effects are handled in the Robin condition by inclusion of a boundary integral term that depends on the pressure. Added-damping effects due to the viscous shear forcesmore » on the body are treated by inclusion of added-damping tensors that are derived through a linearization of the integrals defining the force and torque. Added-damping effects may be important at low Reynolds number, or, for example, in the case of a rotating cylinder or rotating sphere when the rotational moments of inertia are small. In this second part of a two-part series, the general formulation of the AMP scheme is presented including the form of the AMP interface conditions and added-damping tensors for general geometries. A fully second-order accurate implementation of the AMP scheme is developed in two dimensions based on a fractional-step method for the incompressible Navier-Stokes equations using finite difference methods and overlapping grids to handle the moving geometry. Here, the numerical scheme is verified on a number of difficult benchmark problems.« less

  1. Reducing the two-body problem in scalar-tensor theories to the motion of a test particle: A scalar-tensor effective-one-body approach

    NASA Astrophysics Data System (ADS)

    Julié, Félix-Louis

    2018-01-01

    Starting from the second post-Keplerian (2PK) Hamiltonian describing the conservative part of the two-body dynamics in massless scalar-tensor (ST) theories, we build an effective-one-body (EOB) Hamiltonian which is a ν deformation (where ν =0 is the test mass limit) of the analytically known ST Hamiltonian of a test particle. This ST-EOB Hamiltonian leads to a simple (yet canonically equivalent) formulation of the conservative 2PK two-body problem, but also defines a resummation of the dynamics which is well-suited to ST regimes that depart strongly from general relativity (GR) and which may provide information on the strong field dynamics; in particular, the ST innermost stable circular orbit location and associated orbital frequency. Results will be compared and contrasted with those deduced from the ST-deformation of the (5PN) GR-EOB Hamiltonian previously obtained in [Phys. Rev. D 95, 124054 (2017), 10.1103/PhysRevD.95.124054].

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

    NASA Astrophysics Data System (ADS)

    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.

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

    ERIC Educational Resources Information Center

    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)

  4. L^1 -optimality conditions for the circular restricted three-body problem

    NASA Astrophysics Data System (ADS)

    Chen, Zheng

    2016-11-01

    In this paper, the L^1 -minimization for the translational motion of a spacecraft in the circular restricted three-body problem (CRTBP) is considered. Necessary conditions are derived by using the Pontryagin Maximum Principle (PMP), revealing the existence of bang-bang and singular controls. Singular extremals are analyzed, recalling the existence of the Fuller phenomenon according to the theories developed in (Marchal in J Optim Theory Appl 11(5):441-486, 1973; Zelikin and Borisov in Theory of Chattering Control with Applications to Astronautics, Robotics, Economics, and Engineering. Birkhäuser, Basal 1994; in J Math Sci 114(3):1227-1344, 2003). The sufficient optimality conditions for the L^1 -minimization problem with fixed endpoints have been developed in (Chen et al. in SIAM J Control Optim 54(3):1245-1265, 2016). In the current paper, we establish second-order conditions for optimal control problems with more general final conditions defined by a smooth submanifold target. In addition, the numerical implementation to check these optimality conditions is given. Finally, approximating the Earth-Moon-Spacecraft system by the CRTBP, an L^1 -minimization trajectory for the translational motion of a spacecraft is computed by combining a shooting method with a continuation method in (Caillau et al. in Celest Mech Dyn Astron 114:137-150, 2012; Caillau and Daoud in SIAM J Control Optim 50(6):3178-3202, 2012). The local optimality of the computed trajectory is asserted thanks to the second-order optimality conditions developed.

  5. High-Performance Computing and Four-Dimensional Data Assimilation: The Impact on Future and Current Problems

    NASA Technical Reports Server (NTRS)

    Makivic, Miloje S.

    1996-01-01

    This is the final technical report for the project entitled: "High-Performance Computing and Four-Dimensional Data Assimilation: The Impact on Future and Current Problems", funded at NPAC by the DAO at NASA/GSFC. First, the motivation for the project is given in the introductory section, followed by the executive summary of major accomplishments and the list of project-related publications. Detailed analysis and description of research results is given in subsequent chapters and in the Appendix.

  6. The rectilinear three-body problem as a basis for studying highly eccentric systems

    NASA Astrophysics Data System (ADS)

    Voyatzis, G.; Tsiganis, K.; Gaitanas, M.

    2018-01-01

    The rectilinear elliptic restricted three-body problem (TBP) is the limiting case of the elliptic restricted TBP when the motion of the primaries is described by a Keplerian ellipse with eccentricity e'=1, but the collision of the primaries is assumed to be a non-singular point. The rectilinear model has been proposed as a starting model for studying the dynamics of motion around highly eccentric binary systems. Broucke (AIAA J 7:1003-1009, 1969) explored the rectilinear problem and obtained isolated periodic orbits for mass parameter μ =0.5 (equal masses of the primaries). We found that all orbits obtained by Broucke are linearly unstable. We extend Broucke's computations by using a finer search for symmetric periodic orbits and computing their linear stability. We found a large number of periodic orbits, but only eight of them were found to be linearly stable and are associated with particular mean motion resonances. These stable orbits are used as generating orbits for continuation with respect to μ and e'<1. Also, continuation of periodic solutions with respect to the mass of the small body can be applied by using the general TBP. FLI maps of dynamical stability show that stable periodic orbits are surrounded in phase space with regions of regular orbits indicating that systems of very highly eccentric orbits can be found in stable resonant configurations. As an application we present a stability study for the planetary system HD7449.

  7. [Multifaceted body. I. The bodies of medicine].

    PubMed

    Saraga, M; Bourquin, C; Wykretowicz, H; Stiefel, F

    2015-02-11

    The human body is the object upon which medicine is acting, but also lived reality, image, symbol, representation and the object of elaboration and theory. All these elements which constitute the body influence the way medicine is treating it. In this series of three articles, we address the human body from various perspectives: medical (1), phenomenological (2), psychosomatic and socio-anthropological (3). This first article discusses four distinct types of representation of the body within medicine, each related to a specific epistemology and shaping a distinct kind of clinical legitimacy: the body-object of anatomy, the body-machine of physiology, the cybernetic body of biology, the statistical body of epidemiology.

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

    PubMed

    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.

  9. Child body mass index in four cities of East China compared to Western references

    PubMed Central

    Pan, Huiqi; Jiang, Yifang; Jing, Xinming; Fu, Sulin; Jiang, Yan; Lin, Zhongfang; Sheng, Zhihua; Cole, Tim J.

    2008-01-01

    Background The rising trends in child obesity worldwide are poorly documented in China. Aim The present study compared the distribution of body mass index (BMI) by age in children from four cities in East China with Western references. Subjects and methods 94 370 boys and 90 048 girls aged 0–19 years from Shanghai, Jinan, Xuzhou and Hefei were measured in 1999–2004 for length/height and weight. The LMS method was used to construct BMI centiles for each city. Shanghai children aged 0–6 years in 1986 and US and UK BMI references were used for comparison. Results The median BMI curves for the four cities differed in shape from those for the USA and UK. Chinese boys were fatter than US boys in early to mid-childhood but less so in adolescence, and US boys were fatter at age 18. Within China the adiposity rebound was earlier in boys than girls. Shanghai children were appreciably fatter in 2000 than in 1986, and boys more so than girls. Conclusions The roots of child obesity lie in early life, particularly in boys, and are linked to economic development, which has important implications for both the aetiology of child obesity and the health of current and future Chinese children. PMID:19085513

  10. Tsien's method for generating non-Keplerian trajectories. Part 2: The question of thrust to orbit a sphere and the restricted three-body problem

    NASA Technical Reports Server (NTRS)

    Murad, P. A.

    1993-01-01

    Tsien's method is extended to treat the orbital motion of a body undergoing accelerations and decelerations. A generalized solution is discussed for the generalized case where a body undergoes azimuthal and radial thrust and the problem is further simplified for azimuthal thrust alone. Judicious selection of thrust could generate either an elliptic or hyperbolic trajectory. This is unexpected especially when the body has only enough energy for a lower state trajectory. The methodology is extended treating the problem of vehicle thrust for orbiting a sphere and vehicle thrust within the classical restricted three-body problem. Results for the latter situation can produce hyperbolic trajectories through eigen value decomposition. Since eigen values for no-thrust can be imaginary, thrust can generate real eigen values to describe hyperbolic trajectories. Keplerian dynamics appears to represent but a small subset of a much larger non-Keplerian domain especially when thrust effects are considered. The need for high thrust long duration space-based propulsion systems for changing a trajectory's canonical form is clearly demonstrated.

  11. Body Fat Measurements in Singaporean Adults Using Four Methods

    PubMed Central

    Bi, Xinyan; Loo, Yi Ting

    2018-01-01

    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. PMID:29510545

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

    PubMed

    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.

  13. Body handlers after terrorism in Oklahoma City: predictors of posttraumatic stress and other symptoms.

    PubMed

    Tucker, Phebe; Pfefferbaum, Betty; Doughty, Debby E; Jones, Dan E; Jordan, Fred B; Nixon, Sara Jo

    2002-10-01

    Posttraumatic stress and depressive symptoms were assessed in 51 body handlers after Oklahoma City's 1995 terrorist bombing. Although many handlers were inexperienced and knew someone killed, symptoms were low postdisaster and decreased significantly after 1 year. Higher symptomatology and seeking mental health treatment correlated with increases in alcohol use and new physical problems but not with demographics, exposure, or experience. Four respondents with the highest posttraumatic stress symptoms at both time points reported high physical and alcohol use problems and mental health treatment use, suggesting that these should be carefully assessed in body handlers postdisaster. Coping techniques are described, as well as possible reasons for unexpected resilience in the majority.

  14. 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

    NASA Astrophysics Data System (ADS)

    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.

  15. On the co-existence of maximal and whiskered tori in the planetary three-body problem

    NASA Astrophysics Data System (ADS)

    Pinzari, Gabriella

    2018-05-01

    In this paper, we discuss about the possibility of the coexistence of stable and unstable quasi-periodic Kolmogorov-Arnold-Moser (kam) tori in a region of the phase space of the three-body problem. The argument of proof goes along kam theory and, especially, the production of two non-smoothly related systems of canonical coordinates in the same region of the phase space, the possibility of which is foreseen, for "properly degenerate" systems, by a theorem of Nekhoroshev and Miščenko and Fomenko. The two coordinate systems are alternative to the classical reduction of the nodes by Jacobi, described, e.g., in Arnold ["Small denominators and problems of stability of motion in classical and celestial mechanics," 18, 85-191 (1963)].

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

    PubMed

    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.

  17. Exercise load index and changes in body weight during long-duration confinement in an isolated environment

    NASA Technical Reports Server (NTRS)

    Kraft, Norbert O.; Lyons, Terence J.; Binder, Heidi; Inoue, Natsuhiko; Ohshima, Hiroshi; Sekiguchi, Chiharu

    2003-01-01

    PURPOSE: The objectives of this project were to investigate exercise load and body weight related to long-duration confinement in a closed environment simulating ISS flight conditions, and to evaluate subjects' motivation to continue the experiment and their adaptation to isolation. METHODS: Four Russian male subjects participated in a 240-d experiment (Group I), and four subjects (three male subjects and one female subject) from Austria, Canada, Japan, and Russia participated in a 110-d experiment (Group II). Exercise load was estimated during confinement using a modified Rating of Perceived Exertion scale. Free reports were used to determine subjects' motivation. Body weight was measured before, during, and after confinement. RESULTS: Group I achieved their lowest exercise loads during their first month of isolation; problems with adaptation to the isolation environment were also reported during this first month. Group II exercise load was significantly lower in the second month due to crewmember problems; loss of motivation could be noted from their free reports. The subject with the lowest exercise load retired from the isolation experiment earlier than scheduled. Exercise load was not correlated with prior exercise habits. Significant differences in body weight was observed between group I and II and between Russian and non-Russian subjects. One subject in Group I experienced a significant increase in his body weight. CONCLUSION: Exercise load may be a good indicator for adaptation problems and motivation changes in closed environments. Immobility, lack of space, and smoking cessation in general did not induce significant body weight changes.

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

    NASA Astrophysics Data System (ADS)

    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

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

    PubMed

    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.

  20. Agricultural Body-Building: Incorporations of Gender, Body and Work

    ERIC Educational Resources Information Center

    Brandth, Berit

    2006-01-01

    This paper is concerned with gendered embodiment of agricultural work, particularly the connection between women's gender identity and the body at work. Focussing on how the body enters into relations with the tools of work, four processes are identified by which women's bodies, work and machinery are incorporated into each other and give each…

  1. The linear stability of the post-Newtonian triangular equilibrium in the three-body problem

    NASA Astrophysics Data System (ADS)

    Yamada, Kei; Tsuchiya, Takuya

    2017-12-01

    Continuing a work initiated in an earlier publication (Yamada et al. in Phys Rev D 91:124016, 2015), we reexamine the linear stability of the triangular solution in the relativistic three-body problem for general masses by the standard linear algebraic analysis. In this paper, we start with the Einstein-Infeld-Hoffmann form of equations of motion for N-body systems in the uniformly rotating frame. As an extension of the previous work, we consider general perturbations to the equilibrium, i.e., we take account of perturbations orthogonal to the orbital plane, as well as perturbations lying on it. It is found that the orthogonal perturbations depend on each other by the first post-Newtonian (1PN) three-body interactions, though these are independent of the lying ones likewise the Newtonian case. We also show that the orthogonal perturbations do not affect the condition of stability. This is because these do not grow with time, but always precess with two frequency modes, namely, the same with the orbital frequency and the slightly different one due to the 1PN effect. The condition of stability, which is identical to that obtained by the previous work (Yamada et al. 2015) and is valid for the general perturbations, is obtained from the lying perturbations.

  2. From star-disc encounters to numerical solutions for a subset of the restricted three-body problem

    NASA Astrophysics Data System (ADS)

    Breslau, Andreas; Vincke, Kirsten; Pfalzner, Susanne

    2017-03-01

    Various astrophysical processes exist, where the fly-by of a massive object affects matter that is initially supported against gravity by rotation. Examples are perturbations of galaxies, protoplanetary discs, or planetary systems. We approximate such events as a subset of the restricted three-body problem by considering only perturbations of non-interacting low-mass objects that are initially on circular Keplerian orbits. In this paper, we present a new parametrisation of the initial conditions of this problem. Under certain conditions, the initial positions of the low-mass objects can be specified as being largely independent of the initial position of the perturber. In addition, exploiting the known scalings of the problem reduces the parameter space of initial conditions for one specific perturbation to two dimensions. To this two-dimensional initial condition space, we have related the final properties of the perturbed trajectories of the low-mass objects from our numerical simulations. In this way, maps showing the effect of the perturbation on the low-mass objects were created, which provide a new view on the perturbation process. Comparing the maps for different mass-ratios reveals that the perturbations by low- and high-mass perturbers are dominated by different physical processes. The equal-mass case is a complicated mixture of the other two cases. Since the final properties of trajectories with similar initial conditions are also usually similar, the results of the limited number of integrated trajectories can be generalised to the full presented parameter space by interpolation. Since our results are also unique within the accuracy strived for, they constitute general numerical solutions for this subset of the restricted three-body problem. As such, they can be used to predict the evolution of real physical problems by simple transformations, such as scaling, without further simulations. Possible applications are the perturbation of protoplanetary discs

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

    NASA Astrophysics Data System (ADS)

    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

  4. Body Measurement.

    ERIC Educational Resources Information Center

    Neufeld, K. Allen

    1989-01-01

    Described are activities for measuring the human body. The activities include measurements and calculations, calculating volume and density, problems related to body measurement, and using a nomogram. Several charts, illustrations, and a nomogram are provided. (YP)

  5. Arnold diffusion in the planar elliptic restricted three-body problem: mechanism and numerical verification

    NASA Astrophysics Data System (ADS)

    Capiński, Maciej J.; Gidea, Marian; de la Llave, Rafael

    2017-01-01

    We present a diffusion mechanism for time-dependent perturbations of autonomous Hamiltonian systems introduced in Gidea (2014 arXiv:1405.0866). This mechanism is based on shadowing of pseudo-orbits generated by two dynamics: an ‘outer dynamics’, given by homoclinic trajectories to a normally hyperbolic invariant manifold, and an ‘inner dynamics’, given by the restriction to that manifold. On the inner dynamics the only assumption is that it preserves area. Unlike other approaches, Gidea (2014 arXiv:1405.0866) does not rely on the KAM theory and/or Aubry-Mather theory to establish the existence of diffusion. Moreover, it does not require to check twist conditions or non-degeneracy conditions near resonances. The conditions are explicit and can be checked by finite precision calculations in concrete systems (roughly, they amount to checking that Melnikov-type integrals do not vanish and that some manifolds are transversal). As an application, we study the planar elliptic restricted three-body problem. We present a rigorous theorem that shows that if some concrete calculations yield a non zero value, then for any sufficiently small, positive value of the eccentricity of the orbits of the main bodies, there are orbits of the infinitesimal body that exhibit a change of energy that is bigger than some fixed number, which is independent of the eccentricity. We verify numerically these calculations for values of the masses close to that of the Jupiter/Sun system. The numerical calculations are not completely rigorous, because we ignore issues of round-off error and do not estimate the truncations, but they are not delicate at all by the standard of numerical analysis. (Standard tests indicate that we get 7 or 8 figures of accuracy where 1 would be enough.) The code of these verifications is available. We hope that some full computer assisted proofs will be obtained in the near future since there are packages (CAPD) designed for problems of this type.

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

    NASA Astrophysics Data System (ADS)

    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.

  7. ACCURATE ORBITAL INTEGRATION OF THE GENERAL THREE-BODY PROBLEM BASED ON THE D'ALEMBERT-TYPE SCHEME

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Minesaki, Yukitaka

    2013-03-15

    We propose an accurate orbital integration scheme for the general three-body problem that retains all conserved quantities except angular momentum. The scheme is provided by an extension of the d'Alembert-type scheme for constrained autonomous Hamiltonian systems. Although the proposed scheme is merely second-order accurate, it can precisely reproduce some periodic, quasiperiodic, and escape orbits. The Levi-Civita transformation plays a role in designing the scheme.

  8. Coupled orbit-attitude mission design in the circular restricted three-body problem

    NASA Astrophysics Data System (ADS)

    Guzzetti, Davide

    Trajectory design increasingly leverages multi-body dynamical structures that are based on an understanding of various types of orbits in the Circular Restricted Three-Body Problem (CR3BP). Given the more complex dynamical environment, mission applications may also benefit from deeper insight into the attitude motion. In this investigation, the attitude dynamics are coupled with the trajectories in the CR3BP. In a highly sensitive dynamical model, such as the orbit-attitude CR3BP, periodic solutions allow delineation of the fundamental dynamical structures. Periodic solutions are also a subset of motions that are bounded over an infinite time-span (assuming no perturbing factors), without the necessity to integrate over an infinite time interval. Euler equations of motion and quaternion kinematics describe the rotational behavior of the spacecraft, whereas the translation of the center of mass is modeled in the CR3BP equations. A multiple shooting and continuation procedure are employed to target orbit-attitude periodic solutions in this model. Application of Floquet theory, Poincare mapping, and grid search to identify initial guesses for the targeting algorithm is described. In the Earth-Moon system, representative scenarios are explored for axisymmetric vehicles with various inertia characteristics, assuming that the vehicles move along Lyapunov, halo as well as distant retrograde orbits. A rich structure of possible periodic behaviors appears to pervade the solution space in the coupled problem. The stability analysis of the attitude dynamics for the selected families is included. Among the computed solutions, marginally stable and slowly diverging rotational behaviors exist and may offer interesting mission applications. Additionally, the solar radiation pressure is included and a fully coupled orbit-attitude model is developed. With specific application to solar sails, various guidance algorithms are explored to direct the spacecraft along a desired path

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

    PubMed

    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.

  10. Space Instrument Optimization by Implementing of Generic Three Bodies Circular Restricted Problem

    NASA Astrophysics Data System (ADS)

    Nejat, Cyrus

    2011-01-01

    In this study, the main discussion emphasizes on the spacecraft operation with a concentration on stationary points in space. To achieve these objectives, the circular restricted problem was solved for selected approaches. The equations of motion of three body restricted problem was demonstrated to apply in cases other than Lagrange's (1736-1813 A.D.) achievements, by means of the purposed CN (Cyrus Nejat) theorem along with appropriate comments. In addition to five Lagrange, two other points, CN1 and CN2 were found to be in unstable equilibrium points in a very large distance respect to Lagrange points, but stable at infinity. A very interesting simulation of Milky Way Galaxy and Andromeda Galaxy were created to find the Lagrange points, CN points (Cyrus Nejat Points), and CN lines (Cyrus Nejat Lines). The equations of motion were rearranged such a way that the transfer trajectory would be conical, by means of decoupling concept. The main objective was to make a halo orbit transfer about CN lines. The author purposes therefore that all of the corresponding sizing design that they must be developed by optimization techniques would be considered in future approaches. The optimization techniques are sufficient procedures to search for the most ideal response of a system.

  11. INTRODUCTION OF MANY-PARTICLE VARIABLES FOR THE TREATMENT OF SPECIAL TRANSLATIONALLY INVARIANT MANY-BODY PROBLEMS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mobius, P.

    1960-05-01

    An attempt is raade to treat special translationally invariant many-body problems by coordinate transformations introducing many-particle variables. These are adapted coordinates of such kind that the condition of translational invariance and the Pauli principle can be satisfied automatically. They are homogeneous functions of the particle coordinates obeying certain differential equations. The Schrodinger equation is transformed into these variables. There exist examples of systems of interacting particles which can be separated exactly in the many-particle variables but not in the particle coordinates. (auth)

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

    NASA Astrophysics Data System (ADS)

    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.

  13. Development of Four Dimensional Human Model that Enables Deformation of Skin, Organs and Blood Vessel System During Body Movement - Visualizing Movements of the Musculoskeletal System.

    PubMed

    Suzuki, Naoki; Hattori, Asaki; Hashizume, Makoto

    2016-01-01

    We constructed a four dimensional human model that is able to visualize the structure of a whole human body, including the inner structures, in real-time to allow us to analyze human dynamic changes in the temporal, spatial and quantitative domains. To verify whether our model was generating changes according to real human body dynamics, we measured a participant's skin expansion and compared it to that of the model conducted under the same body movement. We also made a contribution to the field of orthopedics, as we were able to devise a display method that enables the observer to more easily observe the changes made in the complex skeletal muscle system during body movements, which in the past were difficult to visualize.

  14. COMMENTS ON THE PAPER 'ON THE STABILITY OF TRIANGULAR LAGRANGIAN POINTS IN THE RESTRICTED THREE-BODY PROBLEM' (2008, AJ, 135, 187)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ivanov, A. P.

    2009-06-15

    In the referenced paper an analytical approach was introduced, which allows one to demonstrate the instability in linearly stable systems, specifically, in a classical three-body problem. These considerations are disproved here.

  15. Experience with Free Bodies

    NASA Technical Reports Server (NTRS)

    Butler, T. G.

    1985-01-01

    Some of the problems that confront an analyst in free body modeling, to satisfy rigid body conditions are discussed and with some remedies for these problems are presented. The problems of detecting these culprits at various levels within the analysis are examined. A new method within NASTRAN for checking the model for defects very early in the analysis without requiring the analyst to bear the expense of an eigenvalue analysis before discovering these defects is outlined.

  16. Longitudinal Association between Short Sleep, Body Weight, and Emotional and Learning Problems in Hispanic and Caucasian Children

    PubMed Central

    Silva, Graciela E.; Goodwin, James L.; Parthasarathy, Sairam; Sherrill, Duane L.; Vana, Kimberly D.; Drescher, Amy A.; Quan, Stuart F.

    2011-01-01

    Study Objective: To determine the impact of lower amounts of childhood sleep assessed by polysomnogram on development of obesity, being anxious or depressed, or having learning problems 5 years later. Design: Prospective cohort. Participants: Subjects were 304 community participants from the Tucson Children's Assessment of Sleep Apnea study, aged 6–12 years old at baseline. Measurements and Results: Children were classified according to baseline sleep as those who slept ≥ 9 h/night, those who slept > 7.5 to < 9 h/night, and those who slept ≤ 7.5 h/night. Odds of overweight/obese (≥ 85th BMI percentile), obese (≥ 95th BMI percentile), anxious or depressed, and learning problems at follow-up were assessed according to baseline sleep categories. Children who slept ≤ 7.5 h/night had higher odds of being obese (OR = 3.3, P < 0.05) at follow-up than children who slept ≥ 9 h/night. Borderline significance for overweight/obese (OR = 2.2, P < 0.1), anxious or depressed (OR = 3.3, P < 0.1), and having learning problems (OR = 11.1, P < 0.1) were seen for children who slept ≤ 7.5 h/night as compared to those who slept ≥ 9 h/night. A mean increase in BMI of 1.7 kg/m2 (P = 0.01) over the 5 years of follow-up was seen for children who slept ≤ 7.5 h/night compared to those who slept ≥ 9 h/night. These relationships did not differ between Hispanic and Caucasian children. Conclusions: Children with reduced amounts of sleep (≤ 7.5 h/night) had an increased risk for higher body weight in early adolescence. Similarly, children who slept ≤ 7.5 h/night had higher risk of being anxious or depressed or having learning problems in early adolescence. Citation: Silva GE; Goodwin JL; Parthasarathy S; Sherrill DL; Vana KD; Drescher AA; Quan SF. Longitudinal association between short sleep, body weight, and emotional and learning problems in Hispanic and Caucasian children. SLEEP 2011;34(9):1197-1205. PMID:21886357

  17. Chaos in a restricted problem of rotation of a rigid body with a fixed point

    NASA Astrophysics Data System (ADS)

    Borisov, A. V.; Kilin, A. A.; Mamaev, I. S.

    2008-06-01

    In this paper, we consider the transition to chaos in the phase portrait of a restricted problem of rotation of a rigid body with a fixed point. Two interrelated mechanisms responsible for chaotization are indicated: (1) the growth of the homoclinic structure and (2) the development of cascades of period doubling bifurcations. On the zero level of the area integral, an adiabatic behavior of the system (as the energy tends to zero) is noted. Meander tori induced by the break of the torsion property of the mapping are found.

  18. Body Weight and Body Image

    PubMed Central

    Olmsted, Marion P; McFarlane, Traci

    2004-01-01

    Health Issue Body weight is of physical and psychological importance to Canadian women; it is associated with health status, physical activity, body image, and self-esteem. Although the problems associated with overweight and obesity are indeed serious, there are also problems connected to being underweight. Weight prejudice and the dieting industry intensify body image concerns for Canadian women and can have a major negative impact on self-esteem. Key Findings Women have lower BMIs than men, a lower incidence of being overweight and a higher incidence of being underweight. However, women across all weight categories are more dissatisfied with their bodies. Sixty percent of women are inactive, and women with a BMI of 27 or higher are more likely to be inactive than women with lower BMIs. The data show that women are aware of the health benefits of exercise, but there is a gap between knowledge and practice. When asked about barriers to health improvement, 39.7% of women cited lack of time and 39.2% lack of willpower. Data Gaps and Recommendations Weight prejudice must be made unacceptable and positive body image should be encouraged and diversity valued. Health policies should encourage healthy eating and healthy activity. Health curricula for young students should include information about healthy eating, active lifestyle, and self-esteem. Physical activities that mothers can participate in with their families should be encouraged. Research should be funded to elucidate the most effective methods of getting women to become and remain physically active without focusing on appearance. PMID:15345068

  19. An intrinsic approach in the curved n-body problem: The negative curvature case

    NASA Astrophysics Data System (ADS)

    Diacu, Florin; Pérez-Chavela, Ernesto; Reyes Victoria, J. Guadalupe

    We consider the motion of n point particles of positive masses that interact gravitationally on the 2-dimensional hyperbolic sphere, which has negative constant Gaussian curvature. Using the stereographic projection, we derive the equations of motion of this curved n-body problem in the Poincaré disk, where we study the elliptic relative equilibria. Then we obtain the equations of motion in the Poincaré upper half plane in order to analyze the hyperbolic and parabolic relative equilibria. Using techniques of Riemannian geometry, we characterize each of the above classes of periodic orbits. For n=2 and n=3 we recover some previously known results and find new qualitative results about relative equilibria that were not apparent in an extrinsic setting.

  20. Null Angular Momentum and Weak KAM Solutions of the Newtonian N-Body Problem

    NASA Astrophysics Data System (ADS)

    Percino-Figueroa, Boris A.

    2017-08-01

    In [Arch. Ration. Mech. Anal. 213 (2014), 981-991] it has been proved that in the Newtonian N-body problem, given a minimal central configuration a and an arbitrary configuration x, there exists a completely parabolic orbit starting on x and asymptotic to the homothetic parabolic motion of a, furthermore such an orbit is a free time minimizer of the action functional. In this article we extend this result in abundance of completely parabolic motions by proving that under the same hypothesis it is possible to get that the completely parabolic motion starting at x has zero angular momentum. We achieve this by characterizing the rotation invariant weak KAM solutions as those defining a lamination on the configuration space by free time minimizers with zero angular momentum.

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

    NASA Astrophysics Data System (ADS)

    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.

  2. Measurement of branching fractions of charmless four-body Λ b 0 and Ξ b 0 decays

    NASA Astrophysics Data System (ADS)

    Aaij, R.; Adeva, B.; Adinolfi, M.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Alfonso Albero, A.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Andreassi, G.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Archilli, F.; d'Argent, P.; Arnau Romeu, J.; Artamonov, A.; Artuso, M.; Aslanides, E.; Atzeni, M.; Auriemma, G.; Baalouch, M.; Babuschkin, I.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baker, S.; Balagura, V.; Baldini, W.; Baranov, A.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Baryshnikov, F.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Beiter, A.; Bel, L. J.; Beliy, N.; Bellee, V.; Belloli, N.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Beranek, S.; Berezhnoy, A.; Bernet, R.; Berninghoff, D.; Bertholet, E.; Bertolin, A.; Betancourt, C.; Betti, F.; Bettler, M.-O.; van Beuzekom, M.; Bezshyiko, Ia.; Bifani, S.; Billoir, P.; Birnkraut, A.; Bizzeti, A.; Bjørn, M.; Blake, T.; Blanc, F.; Blusk, S.; Bocci, V.; Boettcher, T.; Bondar, A.; Bondar, N.; Bordyuzhin, I.; Borghi, S.; Borisyak, M.; Borsato, M.; Bossu, F.; Boubdir, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Braun, S.; Britton, T.; Brodzicka, J.; Brundu, D.; Buchanan, E.; Burr, C.; Bursche, A.; Buytaert, J.; Byczynski, W.; Cadeddu, S.; Cai, H.; Calabrese, R.; Calladine, R.; Calvi, M.; Calvo Gomez, M.; Camboni, A.; Campana, P.; Campora Perez, D. H.; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carniti, P.; Carson, L.; Carvalho Akiba, K.; Casse, G.; Cassina, L.; Cattaneo, M.; Cavallero, G.; Cenci, R.; Chamont, D.; Charles, M.; Charpentier, Ph.; Chatzikonstantinidis, G.; Chefdeville, M.; Chen, S.; Cheung, S. F.; Chitic, S.-G.; Chobanova, V.; Chrzaszcz, M.; Chubykin, A.; Ciambrone, P.; Cid Vidal, X.; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collins, P.; Colombo, T.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombs, G.; Coquereau, S.; Corti, G.; Corvo, M.; Costa Sobral, C. M.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A.; Cruz Torres, M.; Currie, R.; D'Ambrosio, C.; Da Cunha Marinho, F.; Dall'Occo, E.; Dalseno, J.; Davis, A.; De Aguiar Francisco, O.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Serio, M.; De Simone, P.; Dean, C. T.; Decamp, D.; Del Buono, L.; Dembinski, H.-P.; Demmer, M.; Dendek, A.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Di Canto, A.; Di Nezza, P.; Dijkstra, H.; Dordei, F.; Dorigo, M.; Dosil Suárez, A.; Douglas, L.; Dovbnya, A.; Dreimanis, K.; Dufour, L.; Dujany, G.; Durante, P.; Dzhelyadin, R.; Dziewiecki, M.; Dziurda, A.; Dzyuba, A.; Easo, S.; Ebert, M.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; Ely, S.; Esen, S.; Evans, H. M.; Evans, T.; Falabella, A.; Farley, N.; Farry, S.; Fazzini, D.; Federici, L.; Ferguson, D.; Fernandez, G.; Fernandez Declara, P.; Fernandez Prieto, A.; Ferrari, F.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fini, R. A.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fleuret, F.; Fohl, K.; Fontana, M.; Fontanelli, F.; Forshaw, D. C.; Forty, R.; Franco Lima, V.; Frank, M.; Frei, C.; Fu, J.; Funk, W.; Furfaro, E.; Färber, C.; Gabriel, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Garcia Martin, L. M.; García Pardiñas, J.; Garra Tico, J.; Garrido, L.; Garsed, P. J.; Gascon, D.; Gaspar, C.; Gavardi, L.; Gazzoni, G.; Gerick, D.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianì, S.; Gibson, V.; Girard, O. G.; Giubega, L.; Gizdov, K.; Gligorov, V. V.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gorelov, I. V.; Gotti, C.; Govorkova, E.; Grabowski, J. P.; Graciani Diaz, R.; Granado Cardoso, L. A.; Graugés, E.; Graverini, E.; Graziani, G.; Grecu, A.; Greim, R.; Griffith, P.; Grillo, L.; Gruber, L.; Gruberg Cazon, B. R.; Grünberg, O.; Gushchin, E.; Guz, Yu.; Gys, T.; Göbel, C.; Hadavizadeh, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hamilton, B.; Han, X.; Hancock, T. H.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Hasse, C.; Hatch, M.; He, J.; Hecker, M.; Heinicke, K.; Heister, A.; Hennessy, K.; Henrard, P.; Henry, L.; van Herwijnen, E.; Heß, M.; Hicheur, A.; Hill, D.; Hombach, C.; Hopchev, P. H.; Hu, W.; Huard, Z. C.; Hulsbergen, W.; Humair, T.; Hushchyn, M.; Hutchcroft, D.; Ibis, P.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jalocha, J.; Jans, E.; Jawahery, A.; Jiang, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Karacson, M.; Kariuki, J. M.; Karodia, S.; Kazeev, N.; Kecke, M.; Keizer, F.; Kelsey, M.; Kenzie, M.; Ketel, T.; Khairullin, E.; Khanji, B.; Khurewathanakul, C.; Kirn, T.; Klaver, S.; Klimaszewski, K.; Klimkovich, T.; Koliiev, S.; Kolpin, M.; Kopecna, R.; Koppenburg, P.; Kosmyntseva, A.; Kotriakhova, S.; Kozeiha, M.; Kravchuk, L.; Kreps, M.; Kress, F.; Krokovny, P.; Kruse, F.; Krzemien, W.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kuonen, A. K.; Kvaratskheliya, T.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lanfranchi, G.; Langenbruch, C.; Latham, T.; Lazzeroni, C.; Le Gac, R.; Leflat, A.; Lefrançois, J.; Lefèvre, R.; Lemaitre, F.; Lemos Cid, E.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, P.-R.; Li, T.; Li, Y.; Li, Z.; Likhomanenko, T.; Lindner, R.; Lionetto, F.; Lisovskyi, V.; Liu, X.; Loh, D.; Loi, A.; Longstaff, I.; Lopes, J. H.; Lucchesi, D.; Lucio Martinez, M.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Lusiani, A.; Lyu, X.; Machefert, F.; Maciuc, F.; Macko, V.; Mackowiak, P.; Maddrell-Mander, S.; Maev, O.; Maguire, K.; Maisuzenko, D.; Majewski, M. W.; Malde, S.; Malecki, B.; Malinin, A.; Maltsev, T.; Manca, G.; Mancinelli, G.; Marangotto, D.; Maratas, J.; Marchand, J. F.; Marconi, U.; Marin Benito, C.; Marinangeli, M.; Marino, P.; Marks, J.; Martellotti, G.; Martin, M.; Martinelli, M.; Martinez Santos, D.; Martinez Vidal, F.; Massacrier, L. M.; Massafferri, A.; Matev, R.; Mathad, A.; Mathe, Z.; Matteuzzi, C.; Mauri, A.; Maurice, E.; Maurin, B.; Mazurov, A.; McCann, M.; McNab, A.; McNulty, R.; Mead, J. V.; Meadows, B.; Meaux, C.; Meier, F.; Meinert, N.; Melnychuk, D.; Merk, M.; Merli, A.; Michielin, E.; Milanes, D. A.; Millard, E.; Minard, M.-N.; Minzoni, L.; Mitzel, D. S.; Mogini, A.; Molina Rodriguez, J.; Mombacher, T.; Monroy, I. A.; Monteil, S.; Morandin, M.; Morello, M. J.; Morgunova, O.; Moron, J.; Morris, A. B.; Mountain, R.; Muheim, F.; Mulder, M.; Müller, D.; Müller, J.; Müller, K.; Müller, V.; Naik, P.; Nakada, T.; Nandakumar, R.; Nandi, A.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, T. D.; Nguyen-Mau, C.; Nieswand, S.; Niet, R.; Nikitin, N.; Nikodem, T.; Nogay, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Ogilvy, S.; Oldeman, R.; Onderwater, C. J. G.; Ossowska, A.; Otalora Goicochea, J. M.; Owen, P.; Oyanguren, A.; Pais, P. R.; Palano, A.; Palutan, M.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Parker, W.; Parkes, C.; Passaleva, G.; Pastore, A.; Patel, M.; Patrignani, C.; Pearce, A.; Pellegrino, A.; Penso, G.; Pepe Altarelli, M.; Perazzini, S.; Perret, P.; Pescatore, L.; Petridis, K.; Petrolini, A.; Petrov, A.; Petruzzo, M.; Picatoste Olloqui, E.; Pietrzyk, B.; Pikies, M.; Pinci, D.; Pistone, A.; Piucci, A.; Placinta, V.; Playfer, S.; Plo Casasus, M.; Polci, F.; Poli Lener, M.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Pomery, G. J.; Ponce, S.; Popov, A.; Popov, D.; Poslavskii, S.; Potterat, C.; Price, E.; Prisciandaro, J.; Prouve, C.; Pugatch, V.; Puig Navarro, A.; Pullen, H.; Punzi, G.; Qian, W.; Quagliani, R.; Quintana, B.; Rachwal, B.; Rademacker, J. H.; Rama, M.; Ramos Pernas, M.; Rangel, M. S.; Raniuk, I.; Ratnikov, F.; Raven, G.; Ravonel Salzgeber, M.; Reboud, M.; Redi, F.; Reichert, S.; dos Reis, A. C.; Remon Alepuz, C.; Renaudin, V.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Rives Molina, V.; Robbe, P.; Robert, A.; Rodrigues, A. B.; Rodrigues, E.; Rodriguez Lopez, J. A.; Rogozhnikov, A.; Roiser, S.; Rollings, A.; Romanovskiy, V.; Romero Vidal, A.; Ronayne, J. W.; Rotondo, M.; Rudolph, M. S.; Ruf, T.; Ruiz Valls, P.; Ruiz Vidal, J.; Saborido Silva, J. J.; Sadykhov, E.; Sagidova, N.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santimaria, M.; Santovetti, E.; Sarpis, G.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schael, S.; Schellenberg, M.; Schiller, M.; Schindler, H.; Schmelling, M.; Schmelzer, T.; Schmidt, B.; Schneider, O.; Schopper, A.; Schreiner, H. F.; Schubiger, M.; Schune, M.-H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Sepulveda, E. S.; Sergi, A.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Siddi, B. G.; Silva Coutinho, R.; Silva de Oliveira, L.; Simi, G.; Simone, S.; Sirendi, M.; Skidmore, N.; Skwarnicki, T.; Smith, E.; Smith, I. T.; Smith, J.; Smith, M.; Soares Lavra, l.; Sokoloff, M. D.; Soler, F. J. P.; Souza De Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Stefko, P.; Stefkova, S.; Steinkamp, O.; Stemmle, S.; Stenyakin, O.; Stepanova, M.; Stevens, H.; Stone, S.; Storaci, B.; Stracka, S.; Stramaglia, M. E.; Straticiuc, M.; Straumann, U.; Sun, J.; Sun, L.; Sutcliffe, W.; Swientek, K.; Syropoulos, V.; Szumlak, T.; Szymanski, M.; T'Jampens, S.; Tayduganov, A.; Tekampe, T.; Tellarini, G.; Teubert, F.; Thomas, E.; van Tilburg, J.; Tilley, M. J.; Tisserand, V.; Tobin, M.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Toriello, F.; Tourinho Jadallah Aoude, R.; Tournefier, E.; Traill, M.; Tran, M. T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tully, A.; Tuning, N.; Ukleja, A.; Usachov, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagner, A.; Vagnoni, V.; Valassi, A.; Valat, S.; Valenti, G.; Vazquez Gomez, R.; Vazquez Regueiro, P.; Vecchi, S.; van Veghel, M.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Venkateswaran, A.; Verlage, T. A.; Vernet, M.; Vesterinen, M.; Viana Barbosa, J. V.; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Viemann, H.; Vilasis-Cardona, X.; Vitti, M.; Volkov, V.; Vollhardt, A.; Voneki, B.; Vorobyev, A.; Vorobyev, V.; Voß, C.; de Vries, J. A.; Vázquez Sierra, C.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wang, J.; Ward, D. R.; Wark, H. M.; Watson, N. K.; Websdale, D.; Weiden, A.; Weisser, C.; Whitehead, M.; Wicht, J.; Wilkinson, G.; Wilkinson, M.; Williams, M.; Williams, M. P.; Williams, M.; Williams, T.; Wilson, F. F.; Wimberley, J.; Winn, M.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wraight, K.; Wyllie, K.; Xie, Y.; Xu, M.; Xu, Z.; Yang, Z.; Yang, Z.; Yao, Y.; Yin, H.; Yu, J.; Yuan, X.; Yushchenko, O.; Zarebski, K. A.; Zavertyaev, M.; Zhang, L.; Zhang, Y.; Zhelezov, A.; Zheng, Y.; Zhu, X.; Zhukov, V.; Zonneveld, J. B.; Zucchelli, S.

    2018-02-01

    A search for charmless four-body decays of Λ b 0 and Ξ b 0 baryons with a proton and three charged mesons (either kaons or pions) in the final state is performed. The data sample used was recorded in 2011 and 2012 with the LHCb experiment and corresponds to an integrated luminosity of 3 fb-1. Six decay modes are observed, among which Λ b 0 → pK - π + π -, Λ b 0 → pK - K + K -, Ξ b 0 → pK - π + π - and Ξ b 0 → pK - π + K - are established for the first time. Their branching fractions (including the ratio of hadronisation fractions in the case of the Ξ b 0 baryon) are determined relative to the Λ b 0 → Λ c + π - decay.

  3. The full two-body-problem: Simulation, analysis, and application to the dynamics, characteristics, and evolution of binary asteroid systems

    NASA Astrophysics Data System (ADS)

    Fahnestock, Eugene Gregory

    The Full Two-Body-Problem (F2BP) describes the dynamics of two unconstrained rigid bodies in close proximity, having arbitrary spatial distribution of mass, charge, or similar field quantity, and interacting through a mutual potential dependent on that distribution. While the F2BP has applications in areas as wide ranging as molecular dynamics to satellite formation flying, this dissertation focuses on its application to natural bodies in space with nontrivial mass distribution interacting through mutual gravitational potential, i.e. binary asteroids. This dissertation first describes further development and implementation of methods for accurate and efficient F2BP propagation based upon a flexible method for computing the mutual potential between bodies modeled as homogenous polyhedra. Next application of these numerical tools to the study of binary asteroid (66391) 1999 KW4 is summarized. This system typifies the largest class of NEO binaries, which includes nearly half of them, characterized by a roughly oblate spheroid primary rotating rapidly and roughly triaxial ellipsoid secondary in on-average synchronous rotation. Thus KW4's dynamics generalize to any member of that class. Analytical formulae are developed which separately describe the effects of primary oblateness and secondary triaxial ellipsoid shape on frequencies of system motions revealed through the F2BP simulation. These formulae are useful for estimating inertia elements and highest-level internal mass distributions of bodies in any similar system, simply from standoff observation of these motion frequencies. Finally precise dynamical simulation and analysis of the motion of test particles within the time-varying gravity field of the F2BP system is detailed. This Restricted Full-detail Three-Body-Problem encompasses exploration of three types of particle motion within a binary asteroid: (1) Orbital motion such as that for a spacecraft flying within the system about the primary, secondary, or

  4. New doubly-symmetric families of comet-like periodic orbits in the spatial restricted ( N + 1)-body problem

    NASA Astrophysics Data System (ADS)

    Llibre, Jaume; Roberto, Luci Any

    2009-07-01

    For any positive integer N ≥ 2 we prove the existence of a new family of periodic solutions for the spatial restricted ( N +1)-body problem. In these solutions the infinitesimal particle is very far from the primaries. They have large inclinations and some symmetries. In fact we extend results of Howison and Meyer (J. Diff. Equ. 163:174-197, 2000) from N = 2 to any positive integer N ≥ 2.

  5. Patterns of Body Composition Relating to Chronic Respiratory Diseases Among Adults in Four Resource-Poor Settings in Peru.

    PubMed

    Trompeter, Grace; Grigsby, Matthew R; Miele, Catherine H; Wise, Robert A; Gilman, Robert H; Miranda, J Jaime; Bernabe-Ortiz, Antonio; Checkley, William

    2018-06-01

    Body composition is known to influence the development and progression of chronic respiratory diseases (CRDs). We sought to characterize the unique anthropometric phenotypes that present with asthma, chronic obstructive pulmonary disease (COPD), and chronic bronchitis across four distinct settings in Peru. We collected sociodemographic, clinical history, and spirometry data from 2959 participants from Lima, Tumbes, and rural and urban Puno. We compared the prevalence of CRDs among different study sites and described disease phenotypes. We used single and multivariable linear regression to model the influence of CRD status on various descriptors of body composition. Overall prevalence of CRDs varied across sites with the highest prevalence of asthma in Lima (14.5%) and the highest prevalence of COPD in rural Puno (9.9%). Measures of body composition also varied across sites, with highest mean body mass index (BMI) in Lima (28.4 kg/m 2 ) and the lowest mean BMI in rural Puno (25.2 kg/m 2 ). Participants with COPD had the lowest mean fat mass index (FMI) (10.5 kg/m 2 ) and waist circumference (88.3 cm), whereas participants with asthma had the highest mean FMI (14.5 kg/m 2 ), and waist circumference (94.8 cm). In multivariable analysis, participants with COPD had a lower waist circumference (adjusted mean - 2.97 cm, 95% CI 4.62 to - 1.32 cm) when compared to non-CRD participants. Our findings provide evidence that asthma and chronic bronchitis are more likely to be associated with obesity and higher fat mass, while COPD is associated with being underweight and having less lean mass.

  6. The Hubbard Dimer: A Complete DFT Solution to a Many-Body Problem

    NASA Astrophysics Data System (ADS)

    Smith, Justin; Carrascal, Diego; Ferrer, Jaime; Burke, Kieron

    2015-03-01

    In this work we explain the relationship between density functional theory and strongly correlated models using the simplest possible example, the two-site asymmetric Hubbard model. We discuss the connection between the lattice and real-space and how this is a simple model for stretched H2. We can solve this elementary example analytically, and with that we can illuminate the underlying logic and aims of DFT. While the many-body solution is analytic, the density functional is given only implicitly. We overcome this difficulty by creating a highly accurate parameterization of the exact function. We use this parameterization to perform benchmark calculations of correlation kinetic energy, the adiabatic connection, etc. We also test Hartree-Fock and the Bethe Ansatz Local Density Approximation. We also discuss and illustrate the derivative discontinuity in the exchange-correlation energy and the infamous gap problem in DFT. DGE-1321846, DE-FG02-08ER46496.

  7. Sitnikov problem in the square configuration: elliptic case

    NASA Astrophysics Data System (ADS)

    Shahbaz Ullah, M.

    2016-05-01

    This paper is extension to the classical Sitnikov problem, when the four primaries of equal masses lie at the vertices of a square for all time and moving in elliptic orbits around their center of mass of the system, the distances between the primaries vary with time but always in such a way that their mutual distances remain in the same ratio. First we have established averaged equation of motion of the Sitnikov five-body problem in the light of Jalali and Pourtakdoust (Celest. Mech. Dyn. Astron. 68:151-162, 1997), by applying the Van der Pol transformation and averaging technique of Guckenheimer and Holmes (Nonlinear oscillations, dynamical system bifurcations of vector fields, Springer, Berlin, 1983). Next the Hamiltonian equation of motion has been solved with the help of action angle variables I and φ. Finally the periodicity and stability of the Sitnikov five-body problem have been examined with the help of Poincare surfaces of section (PSS). It is shown that chaotic region emerging from the destroyed islands, can easily be seen by increasing the eccentricity of the primaries to e = 0.21. It is valid for bounded small amplitude solutions z_{max} ( z_{max} = 0.65 ) and 0 ≤ e < 0.3.

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

    PubMed

    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

  9. Ballistic Transport for Limit-Periodic Jacobi Matrices with Applications to Quantum Many-Body Problems

    NASA Astrophysics Data System (ADS)

    Fillman, Jake

    2017-03-01

    We study Jacobi matrices that are uniformly approximated by periodic operators. We show that if the rate of approximation is sufficiently rapid, then the associated quantum dynamics are ballistic in a rather strong sense; namely, the (normalized) Heisenberg evolution of the position operator converges strongly to a self-adjoint operator that is injective on the space of absolutely summable sequences. In particular, this means that all transport exponents corresponding to well-localized initial states are equal to one. Our result may be applied to a class of quantum many-body problems. Specifically, we establish a lower bound on the Lieb-Robinson velocity for an isotropic XY spin chain on the integers with limit-periodic couplings.

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

    PubMed

    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

  11. Quality of Life of Country Families in Four Eastern Kentucky Counties: Change and Persistent Problems, 1961 and 1973. RS-46.

    ERIC Educational Resources Information Center

    Coughenour, C. Milton

    Change and persistent problems in the quality of life of open-country families (n=317) in four eastern Kentucky counties (Harlan, Perry, Whitley, and Wolfe) were examined via comparison of data derived from surveys of household heads in 1961 and 1973. The 1961 survey provided data on occupations, income, level of living, and opinions re: the…

  12. 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.

    PubMed

    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.

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

    PubMed

    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, p<.001). Our results emphasize the transactional association between maternal self-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.

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

    PubMed

    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

  15. Calculation of double-lunar swingby trajectories: Part 2: Numerical solutions in the restricted problem of three bodies

    NASA Technical Reports Server (NTRS)

    Stalos, S.

    1990-01-01

    The double-lunar swingby trajectory is a method for maintaining alignment of an Earth satellite's line of apsides with the Sun-Earth line. From a Keplerian point of view, successive close encounters with the Moon cause discrete, instantaneous changes in the satellite's eccentricity and semimajor axis. Numerical solutions to the planar, restricted problem of three bodies as double-lunar swingby trajectories are identified. The method of solution is described and the results compared to the Keplerian formulation.

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

    PubMed

    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.

  17. A gravitational potential finding for rotating cosmological body in the context of proto-planetary dynamics problem solving

    NASA Astrophysics Data System (ADS)

    Krot, Alexander M.

    2008-09-01

    The statistical theory for a cosmological body forming (so-called the spheroidal body model) has been proposed in [1]-[9]. Within the framework of this theory, bodies have fuzzy outlines and are represented by means of spheroidal forms [1],[2]. In the work [3], it has been investigated a slowly evolving in time process of a gravitational compression of a spheroidal body close to an unstable equilibrium state. In the papers [4],[5], the equation of motion of particles inside the weakly gravitating spheroidal body modeled by means of an ideal liquid has been obtained. Using Schwarzschild's and Kerr's metrics a consistency of the proposed statistical model with the general relativity has been shown in [6]. The proposed theory follows from the conception for forming a spheroidal body from protoplanetary nebula [7],[8]; it permits to derive the form of distribution functions for an immovable [1]-[5] and rotating spheroidal body [6]-[8] as well as their density masses and also the distribution function of specific angular momentum of the rotating uniformly spheroidal body [7],[8]. It is well-known there is not a statistical equilibrium in a gas-dust proto-planetary cloud because of long relaxation time for proto-planets formation in own gravitational field. This proto-planetary system behavior can be described by Jeans' equation in partial derivations relative to a distribution function [9]. The problem for finding a general solution of Jeans' equation is connected directly with an analytical expression for potential of gravitational field. Thus, the determination of gravitational potential is the main problem of statistical dynamics for proto-planetary system [9]. This work shows this task of proto-planetary dynamics can be solved on the basis of spheroidal bodies theory. The proposed theory permits to derive the form of gravitational potential for a rotating spheroidal body at a long distance from its center. Using the obtained analytical expression for potential of

  18. On the period of the periodic orbits of the restricted three body problem

    NASA Astrophysics Data System (ADS)

    Perdomo, Oscar

    2017-09-01

    We will show that the period T of a closed orbit of the planar circular restricted three body problem (viewed on rotating coordinates) depends on the region it encloses. Roughly speaking, we show that, 2 T=kπ +\\int _Ω g where k is an integer, Ω is the region enclosed by the periodic orbit and g:R^2→ R is a function that only depends on the constant C known as the Jacobian constant; it does not depend on Ω . This theorem has a Keplerian flavor in the sense that it relates the period with the space "swept" by the orbit. As an application we prove that there is a neighborhood around L_4 such that every periodic solution contained in this neighborhood must move clockwise. The same result holds true for L_5.

  19. Comment on "Out-of-plane equilibrium points in the restricted three-body problem with oblateness (Research Note)"

    NASA Astrophysics Data System (ADS)

    Wu, Nan; Wang, Xuefeng; Zhou, Li-Yong

    2018-06-01

    Douskos & Markellos (2006, A&A, 446, 357) first reported the existence of the out-of-plane equilibrium points in restricted three-body problem with oblateness. This result deviates significantly from the intuitive physical point of view that there is no other force that can balance the combined gravitation in Z direction. In fact, the out-of-plane equilibrium in that model is illusory and we prove here that such equilibrium points arise from the improper application of the potential function.

  20. Does morphology predict trophic niche differentiation? Relationship between feeding habits and body shape in four co-occurring juvenile species (Pisces: Perciformes, Sparidae)

    NASA Astrophysics Data System (ADS)

    Ventura, Daniele; Bonhomme, Vincent; Colangelo, Paolo; Bonifazi, Andrea; Jona Lasinio, Giovanna; Ardizzone, Giandomenico

    2017-05-01

    Feeding habits, diet overlap and morphological correlates of four juvenile species of the genus Diplodus were investigated during their settlement periods, along the Tyrrhenian coast. Stomach content analysis showed that the diets of D. sargus and D. puntazzo mainly comprised benthic prey such as harpacticoid copepods, amphipods and polychaetes. On the other hand, D. vulgaris and D. annularis fed mainly on planktonic prey such as ciclopoids, calanoids copepods and fish larvae. A biologically significant diet overlap, calculated using the Schoener index, was recorded between D. sargus and D. puntazzo and between D. vulgaris and D. annularis. Morphological characters related to feeding such as gape height and gut length with their relative growth patterns suggested that different trophic preferences have led to a morphological diversification of feeding structures. Therefore, a geometric morphometric outline method, namely Elliptic Fourier Analysis (EFA) was used to examine shape modification of the head and body regions. The multivariate analyses performed on shape descriptors demonstrated that the four species were morphologically distinct due to different feeding habits: the two species which feed mainly on benthic prey presented a discoidal shape, with broad profiles and rounded head; by contrast, the other two species which relied mostly on planktonic prey, presented a streamlined and more elongated body shape.

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

    NASA Astrophysics Data System (ADS)

    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.

  2. Sprinkler Body Fact Sheet

    EPA Pesticide Factsheets

    Landscape irrigation sprinklers are often installed at sites where the system pressure is higher than what is recommended for the sprinkler body, thus resulting in system inefficiencies. WaterSense labeled sprinkler bodies can address this problem.

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

    NASA Astrophysics Data System (ADS)

    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.

  4. Optimal transfers between libration-point orbits in the elliptic restricted three-body problem

    NASA Astrophysics Data System (ADS)

    Hiday, Lisa Ann

    1992-09-01

    A strategy is formulated to design optimal impulsive transfers between three-dimensional libration-point orbits in the vicinity of the interior L(1) libration point of the Sun-Earth/Moon barycenter system. Two methods of constructing nominal transfers, for which the fuel cost is to be minimized, are developed; both inferior and superior transfers between two halo orbits are considered. The necessary conditions for an optimal transfer trajectory are stated in terms of the primer vector. The adjoint equation relating reference and perturbed trajectories in this formulation of the elliptic restricted three-body problem is shown to be distinctly different from that obtained in the analysis of trajectories in the two-body problem. Criteria are established whereby the cost on a nominal transfer can be improved by the addition of an interior impulse or by the implementation of coastal arcs in the initial and final orbits. The necessary conditions for the local optimality of a time-fixed transfer trajectory possessing additional impulses are satisfied by requiring continuity of the Hamiltonian and the derivative of the primer vector at all interior impulses. The optimality of a time-free transfer containing coastal arcs is surmised by examination of the slopes at the endpoints of a plot of the magnitude of the primer vector over the duration of the transfer path. If the initial and final slopes of the primer magnitude are zero, the transfer trajectory is optimal; otherwise, the execution of coasts is warranted. The position and timing of each interior impulse applied to a time-fixed transfer as well as the direction and length of coastal periods implemented on a time-free transfer are specified by the unconstrained minimization of the appropriate variation in cost utilizing a multivariable search technique. Although optimal solutions in some instances are elusive, the time-fixed and time-free optimization algorithms prove to be very successful in diminishing costs on

  5. Brain size predicts problem-solving ability in mammalian carnivores

    PubMed Central

    Benson-Amram, Sarah; Dantzer, Ben; Stricker, Gregory; Swanson, Eli M.; Holekamp, Kay E.

    2016-01-01

    Despite considerable interest in the forces shaping the relationship between brain size and cognitive abilities, it remains controversial whether larger-brained animals are, indeed, better problem-solvers. Recently, several comparative studies have revealed correlations between brain size and traits thought to require advanced cognitive abilities, such as innovation, behavioral flexibility, invasion success, and self-control. However, the general assumption that animals with larger brains have superior cognitive abilities has been heavily criticized, primarily because of the lack of experimental support for it. Here, we designed an experiment to inquire whether specific neuroanatomical or socioecological measures predict success at solving a novel technical problem among species in the mammalian order Carnivora. We presented puzzle boxes, baited with food and scaled to accommodate body size, to members of 39 carnivore species from nine families housed in multiple North American zoos. We found that species with larger brains relative to their body mass were more successful at opening the boxes. In a subset of species, we also used virtual brain endocasts to measure volumes of four gross brain regions and show that some of these regions improve model prediction of success at opening the boxes when included with total brain size and body mass. Socioecological variables, including measures of social complexity and manual dexterity, failed to predict success at opening the boxes. Our results, thus, fail to support the social brain hypothesis but provide important empirical support for the relationship between relative brain size and the ability to solve this novel technical problem. PMID:26811470

  6. Brain size predicts problem-solving ability in mammalian carnivores.

    PubMed

    Benson-Amram, Sarah; Dantzer, Ben; Stricker, Gregory; Swanson, Eli M; Holekamp, Kay E

    2016-03-01

    Despite considerable interest in the forces shaping the relationship between brain size and cognitive abilities, it remains controversial whether larger-brained animals are, indeed, better problem-solvers. Recently, several comparative studies have revealed correlations between brain size and traits thought to require advanced cognitive abilities, such as innovation, behavioral flexibility, invasion success, and self-control. However, the general assumption that animals with larger brains have superior cognitive abilities has been heavily criticized, primarily because of the lack of experimental support for it. Here, we designed an experiment to inquire whether specific neuroanatomical or socioecological measures predict success at solving a novel technical problem among species in the mammalian order Carnivora. We presented puzzle boxes, baited with food and scaled to accommodate body size, to members of 39 carnivore species from nine families housed in multiple North American zoos. We found that species with larger brains relative to their body mass were more successful at opening the boxes. In a subset of species, we also used virtual brain endocasts to measure volumes of four gross brain regions and show that some of these regions improve model prediction of success at opening the boxes when included with total brain size and body mass. Socioecological variables, including measures of social complexity and manual dexterity, failed to predict success at opening the boxes. Our results, thus, fail to support the social brain hypothesis but provide important empirical support for the relationship between relative brain size and the ability to solve this novel technical problem.

  7. Radiation Pressure, Poynting-Robertson Drag, and Solar Wind Drag in the Restricted Three-Body Problem

    NASA Technical Reports Server (NTRS)

    Liou, Jer-Chyi; Zook, Herbert A.; Jackson, A. A.

    1995-01-01

    In this paper, we examine the effects of radiation pressure, Poynting-Robertson (PR) drag, and solar wind drag on dust grains trapped in mean motion resonances with the Sun and Jupiter in the restricted (negligible dust mass) three-body Problem. We especially examine the evolution of dust grains in the 1:1 resonance. As a first step, the Sun and Jupiter are idealized to both be in circular orbit about a common center of mass (circular restricted three-body problem). From the equation of motion of the dust particle in the rotating reference frame, the drag-induced time rate of change of its Jacobi "constant," C, is then derived and expressed in spherical coordinates. This new mathematical expression in spherical coordinates shows that C, in the 1:1 resonance, both oscillates and secularly increases with increasing time. The new expression gives rise to an easy understanding of how an orbit evolves when the radiation force and solar wind drag are included. All dust grain orbits are unstable in time when PR and solar wind drag are included in the Sun-Jupiter-dust system. Tadpole orbits evolve into horseshoe orbits; and these orbits continuously expand in size to lead to close encounters with Jupiter. Permanent trapping is impossible. Orbital evolutions of a dust grain trapped in the 1:1 resonance in the planar circular, an inclined case, an eccentric case, and the actual Sun-Jupiter case are numerically simulated and compared with each other and show grossly similar time behavior. Resonances other than 1:1 are also explored with the new expression. Stable exterior resonance trapping may be possible under certain conditions. One necessary condition for such a trap is derived. Trapping in interior resonances is shown to be always unstable.

  8. The Relationships among Body Image, Body Mass Index, Exercise, and Sexual Functioning in Heterosexual Women

    ERIC Educational Resources Information Center

    Weaver, Angela D.; Byers, E. Sandra

    2006-01-01

    Problems related to negative body image are very common among young women. In this study, we examined the relationship between women's body image and their sexual functioning over and above the effects of physical exercise and body mass index (BMI) in a sample of 214 university women. Low situational body image dysphoria and low body…

  9. Three-body Coulomb problem probed by mapping the Bethe surface in ionizing ion-atom collisions.

    PubMed

    Moshammer, R; Perumal, A; Schulz, M; Rodríguez, V D; Kollmus, H; Mann, R; Hagmann, S; Ullrich, J

    2001-11-26

    The three-body Coulomb problem has been explored in kinematically complete experiments on single ionization of helium by 100 MeV/u C(6+) and 3.6 MeV/u Au(53+) impact. Low-energy electron emission ( E(e)<150 eV) as a function of the projectile deflection theta(p) (momentum transfer), i.e., the Bethe surface [15], has been mapped with Delta theta(p)+/-25 nanoradian resolution at extremely large perturbations ( 3.6 MeV/u Au(53+)) where single ionization occurs at impact parameters of typically 10 times the He K-shell radius. The experimental data are not in agreement with state-of-the-art continuum distorted wave-eikonal initial state theory.

  10. On the conservation of the Jacobi integral in the post-Newtonian circular restricted three-body problem

    NASA Astrophysics Data System (ADS)

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

    2017-05-01

    In the present paper, using the first-order approximation of the n-body Lagrangian (derived on the basis of the post-Newtonian gravitational theory of Einstein, Infeld, and Hoffman), we explicitly write down the equations of motion for the planar circular restricted three-body problem in the Solar system. Additionally, with some simplified assumptions, we obtain two formulas for estimating the values of the mass-distance and velocity-speed of light ratios appropriate for a given post-Newtonian approximation. We show that the formulas derived in the present study, lead to good numerical accuracy in the conservation of the Jacobi constant and almost allow for an equivalence between the Lagrangian and Hamiltonian approaches at the same post-Newtonian order. Accordingly, the dynamics of the system is analyzed in terms of the Poincaré sections method and Lyapunov exponents, finding that for specific values of the Jacobi constant the dynamics can be either chaotic or regular. Our results suggest that the chaoticity of the post-Newtonian system is slightly increased in comparison with its Newtonian counterpart.

  11. Counting relative equilibrium configurations of the full two-body problem

    NASA Astrophysics Data System (ADS)

    Moeckel, Richard

    2018-02-01

    Consider a system of two rigid, massive bodies interacting according to their mutual gravitational attraction. In a relative equilibrium motion, the bodies rotate rigidly and uniformly about a fixed axis in R^3. This is possible only for special positions and orientations of the bodies. After fixing the angular momentum, these relative equilibrium configurations can be characterized as critical points of a smooth function on configuration space. The goal of this paper is to use Morse theory and Lusternik-Schnirelmann category theory to give lower bounds for the number of critical points when the angular momentum is sufficiently large. In addition, the exact number of critical points and their Morse indices are found in the limit as the angular momentum tends to infinity.

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

    PubMed

    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

  13. Motion in a modified Chermnykh's restricted three-body problem with oblateness

    NASA Astrophysics Data System (ADS)

    Singh, Jagadish; Leke, Oni

    2014-03-01

    In this paper, the restricted problem of three bodies is generalized to include a case when the passively gravitating test particle is an oblate spheroid under effect of small perturbations in the Coriolis and centrifugal forces when the first primary is a source of radiation and the second one an oblate spheroid, coupled with the influence of the gravitational potential from the belt. The equilibrium points are found and it is seen that, in addition to the usual three collinear equilibrium points, there appear two new ones due to the potential from the belt and the mass ratio. Two triangular equilibrium points exist. These equilibria are affected by radiation of the first primary, small perturbation in the centrifugal force, oblateness of both the test particle and second primary and the effect arising from the mass of the belt. The linear stability of the equilibrium points is explored and the stability outcome of the collinear equilibrium points remains unstable. In the case of the triangular points, motion is stable with respect to some conditions which depend on the critical mass parameter; influenced by the small perturbations, radiating effect of the first primary, oblateness of the test body and second primary and the gravitational potential from the belt. The effects of each of the imposed free parameters are analyzed. The potential from the belt and small perturbation in the Coriolis force are stabilizing parameters while radiation, small perturbation in the centrifugal force and oblateness reduce the stable regions. The overall effect is that the region of stable motion increases under the combine action of these parameters. We have also found the frequencies of the long and short periodic motion around stable triangular points. Illustrative numerical exploration is rendered in the Sun-Jupiter and Sun-Earth systems where we show that in reality, for some values of the system parameters, the additional equilibrium points do not in general exist even when

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Martinelli, Maurizio

    2011-02-01

    We search for CP violation in a sample of 4.7 x 10 4 singly Cabibbo suppressed D 0 → K + K - π +π - decays and 1.8(2.6) x 10 4 D (s) + → K S 0 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(D 0) = (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 andmore » 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.« less

  15. [Four-stage gradual expanding approach of problem based learning in otorhinolaryngology].

    PubMed

    Kong, Weijia; Wang, Yanjun; Yue, Jianxin; Chen, Jianjun; Peng, Yixiang; Zhang, Sulin; Zhang, Xiaomeng

    2008-08-01

    The aim of the study is to cover the shortages of PBL, such as time-consuming, abstract, lacking of the course of clinic practice, and to introduce PBL to the teaching of otorhinolaryngology. By the improvement of the international classic teaching model of PBL, we put forward "four-stage gradual expanding approach of PBL" and establish "four-stage gradual expanding approach of PBL in otorhinolaryngology". Through the four stages of watching PBL, simulation PBL, internship PBL, practice PBL, we have accomplished the organic integration of theory teaching and clinical practice. This teaching method is more adaptive to the teaching of otorhinolaryngology, and it can help the medicine students to establish the whole concept of medicine and can stimulate them to form the good habits of self-regulated learning and life-long learning efficiently.

  16. US pediatric population-level associations of DXA-measured percentage of body fat with four BMI metrics with cutoffs

    PubMed Central

    Heo, Moonseong; Wylie-Rosett, Judith; Pietrobelli, Angelo; Kabat, Geoffrey C.; Rohan, Thomas E.; Faith, Myles S.

    2013-01-01

    Objective Four body mass index (BMI) metrics—BMI, BMI z-score, BMI percentile, and BMI%—are commonly used as proxy measures for children's adiposity. We sought to determine a BMI metric that is most strongly associated with measured percentage of body fat (%BF) in the US pediatric population stratified by sex, age and race/ethnicity, and to determine cutoffs that maximize the association for each BMI metric. Subjects, Design and Methods %BF was measured by DXA among N=6120 US boys and girls aged 8.0 to 17.9 years old from NHANES 1999-2004. We fit piece-wise linear regression models with cutoffs to %BF data using each BMI metric as the predictor stratified by sex, race/ethnicity and age. The slopes were modeled differently before and after the cutoffs which were determined based on grid searches. Results BMI z-score was in general most strongly associated with %BF for both boys and girls. The associations of the four BMI metrics were lowest for boys aged 12-13.9 years and girls aged 16-17.9 years, and strongest for Mexican-American boys and for non-Hispanic black girls. Overall, the associations were stronger for girls than for boys. In boys, BMI had the lowest association with %BF (R2=0.39) for all ages combined. The fold changes in slopes before and after cutoffs were greatest in general for BMI percentiles regardless of age, sex and race/ethnicity. BMI z-score cutoffs were 0.4 for both boys and girls for all ages combined. Except for BMI, the slopes after the cutoffs were in general greater than those before. Conclusions All BMI metrics were strongly associated with %BF when stratified by age and race/ethnicity except that BMI was the least associated with %BF in boys for all ages combined. Overall, BMI z-score was superior for evaluation of %BF, and its cutoff of 0.4 can also serve as a threshold for careful monitoring of weight status. PMID:23887060

  17. US pediatric population-level associations of DXA-measured percentage of body fat with four BMI metrics with cutoffs.

    PubMed

    Heo, M; Wylie-Rosett, J; Pietrobelli, A; Kabat, G C; Rohan, T E; Faith, M S

    2014-01-01

    Four body mass index (BMI) metrics--BMI, BMI z-score, BMI percentile and BMI%--are commonly used as proxy measures for children's adiposity. We sought to determine a BMI metric that is most strongly associated with measured percentage of body fat (%BF) in the US pediatric population stratified by sex, age and race/ethnicity, and to determine cutoffs that maximize the association for each BMI metric. SUBJECTS, DESIGN AND METHODS: %BF was measured by dual-energy X-ray absorptiometry among N=6120 US boys and girls aged 8.0-17.9 years old from the National Health and Nutrition Examination Survey 1999-2004. We fit piecewise linear regression models with cutoffs to %BF data using each BMI metric as the predictor stratified by sex, race/ethnicity and age. The slopes were modeled differently before and after the cutoffs which were determined on the basis of grid searches. BMI z-score was in general most strongly associated with %BF for both boys and girls. The associations of the four BMI metrics were lowest for boys aged 12-13.9 years and girls aged 16-17.9 years, and strongest for Mexican-American boys and for non-Hispanic Black girls. Overall, the associations were stronger for girls than for boys. In boys, BMI had the lowest association with %BF (R(2)=0.39) for all ages combined. The fold changes in slopes before and after cutoffs were greatest in general for BMI percentiles regardless of age, sex and race/ethnicity. BMI z-score cutoffs were 0.4 for both boys and girls for all ages combined. Except for BMI, the slopes after the cutoffs were in general greater than those before. All BMI metrics were strongly associated with %BF when stratified by age and race/ethnicity except that BMI was the least associated with %BF in boys for all ages combined. Overall, BMI z-score was superior for evaluation of %BF, and its cutoff of 0.4 can also serve as a threshold for careful monitoring of weight status.

  18. Motions of Kepler circumbinary planets in restricted three-body problem under radiating primaries

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dermawan, B., E-mail: budider@as.itb.ac.id; Hidayat, T., E-mail: taufiq@as.itb.ac.id; Huda, I. N., E-mail: ibnu.nurul@students.itb.ac.id

    2015-09-30

    By observing continuously a single field of view in the sky, Kepler mission reveals outstanding results on discoveries of exoplanets. One of its recent progress is the discoveries of circumbinary planets. A circumbinary planet is an exoplanet that moves around a binary system. In this study we investigate motions of Kepler circumbinary planets belong to six binary systems, namely Kepler-16, -34, -35, -38, -47, and -413. The motions are considered to follow the Restricted Three-Body Problem (RTBP). Because the primaries (central massive objects) are stars, they are both radiatives, while the planet is an infinitesimal object. The primaries move inmore » nearly circular and elliptic orbits with respect to their center of masses. We describe, in general, motions of the circumbinary planets in RTBP under radiating primaries. With respect to the averaged zero velocity curves, we show that motions of the exoplanets are stable, in accordance with their Hill stabilities.« less

  19. Biodynamics of deformable human body motion

    NASA Technical Reports Server (NTRS)

    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.

  20. Unchained polygons and the N-body problem

    NASA Astrophysics Data System (ADS)

    Chenciner, A.; Féjoz, J.

    2009-02-01

    We study both theoretically and numerically the Lyapunov families which bifurcate in the vertical direction from a horizontal relative equilibrium in ℝ3. As explained in [1], very symmetric relative equilibria thus give rise to some recently studied classes of periodic solutions. We discuss the possibility of continuing these families globally as action minimizers in a rotating frame where they become periodic solutions with particular symmetries. A first step is to give estimates on intervals of the frame rotation frequency over which the relative equilibrium is the sole absolute action minimizer: this is done by generalizing to an arbitrary relative equilibrium the method used in [2] by V. Batutello and S. Terracini. In the second part, we focus on the relative equilibrium of the equal-mass regular N-gon. The proof of the local existence of the vertical Lyapunov families relies on the fact that the restriction to the corresponding directions of the quadratic part of the energy is positive definite. We compute the symmetry groups G r/s ( N, k, η) of the vertical Lyapunov families observed in appropriate rotating frames, and use them for continuing the families globally. The paradigmatic examples are the “Eight” families for an odd number of bodies and the “Hip- Hop” families for an even number. The first ones generalize Marchal’s P 12 family for 3 bodies, which starts with the equilateral triangle and ends with the Eight [1, 3-6]; the second ones generalize the Hip-Hop family for 4 bodies, which starts from the square and ends with the Hip-Hop [1, 7, 8]. We argue that it is precisely for these two families that global minimization may be used. In the other cases, obstructions to the method come from isomorphisms between the symmetries of different families; this is the case for the so-called “chain” choreographies (see [6]), where only a local minimization property is true (except for N = 3). Another interesting feature of these chains is the

  1. Sitnikov cyclic configuration of N+1-body problem

    NASA Astrophysics Data System (ADS)

    Shahbaz Ullah, M.; Hassan, M. R.

    2014-12-01

    This manuscript deals with the generalisation of all previous works on series solutions and linear stability of equilibrium points of the Sitnikov problem. Following Giacaglia (1967), in Sect. 2 we have derived the equation of motion of the infinitesimal mass moving along the z-axis about which the plane of motion is rotating with unit angular velocity. In Sects. 3, 4 and 5 the series solutions of the Sitnikov problem have been developed by the method of MacMillan, Lindstedt-Poincaré and iteration of Green's function respectively. In Sect. 6 the three series solutions have been compared graphically by putting N=2, 3, 4. In Sect. 7 the coordinates of equilibrium points have been calculated. In Sect. 8 the linear stability of equilibrium points has been examined by the method of Murray and Dermott (Solar System Dynamics, Cambridge University Press, Cambridge, 1999) and it was found that the equilibrium points are stable in Sitnikov problem.

  2. Over my fake body: body ownership illusions for studying the multisensory basis of own-body perception

    PubMed Central

    Kilteni, Konstantina; Maselli, Antonella; Kording, Konrad P.; Slater, Mel

    2015-01-01

    Which is my body and how do I distinguish it from the bodies of others, or from objects in the surrounding environment? The perception of our own body and more particularly our sense of body ownership is taken for granted. Nevertheless, experimental findings from body ownership illusions (BOIs), show that under specific multisensory conditions, we can experience artificial body parts or fake bodies as our own body parts or body, respectively. The aim of the present paper is to discuss how and why BOIs are induced. We review several experimental findings concerning the spatial, temporal, and semantic principles of crossmodal stimuli that have been applied to induce BOIs. On the basis of these principles, we discuss theoretical approaches concerning the underlying mechanism of BOIs. We propose a conceptualization based on Bayesian causal inference for addressing how our nervous system could infer whether an object belongs to our own body, using multisensory, sensorimotor, and semantic information, and we discuss how this can account for several experimental findings. Finally, we point to neural network models as an implementational framework within which the computational problem behind BOIs could be addressed in the future. PMID:25852524

  3. Understanding the many-body expansion for large systems. II. Accuracy considerations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lao, Ka Un; Liu, Kuan-Yu; Richard, Ryan M.

    2016-04-28

    To complement our study of the role of finite precision in electronic structure calculations based on a truncated many-body expansion (MBE, or “n-body expansion”), we examine the accuracy of such methods in the present work. Accuracy may be defined either with respect to a supersystem calculation computed at the same level of theory as the n-body calculations, or alternatively with respect to high-quality benchmarks. Both metrics are considered here. In applications to a sequence of water clusters, (H{sub 2}O){sub N=6−55} described at the B3LYP/cc-pVDZ level, we obtain mean absolute errors (MAEs) per H{sub 2}O monomer of ∼1.0 kcal/mol for two-bodymore » expansions, where the benchmark is a B3LYP/cc-pVDZ calculation on the entire cluster. Three- and four-body expansions exhibit MAEs of 0.5 and 0.1 kcal/mol/monomer, respectively, without resort to charge embedding. A generalized many-body expansion truncated at two-body terms [GMBE(2)], using 3–4 H{sub 2}O molecules per fragment, outperforms all of these methods and affords a MAE of ∼0.02 kcal/mol/monomer, also without charge embedding. GMBE(2) requires significantly fewer (although somewhat larger) subsystem calculations as compared to MBE(4), reducing problems associated with floating-point roundoff errors. When compared to high-quality benchmarks, we find that error cancellation often plays a critical role in the success of MBE(n) calculations, even at the four-body level, as basis-set superposition error can compensate for higher-order polarization interactions. A many-body counterpoise correction is introduced for the GMBE, and its two-body truncation [GMBCP(2)] is found to afford good results without error cancellation. Together with a method such as ωB97X-V/aug-cc-pVTZ that can describe both covalent and non-covalent interactions, the GMBE(2)+GMBCP(2) approach provides an accurate, stable, and tractable approach for large systems.« less

  4. Graphing as a Problem-Solving Strategy.

    ERIC Educational Resources Information Center

    Cohen, Donald

    1984-01-01

    The focus is on how line graphs can be used to approximate solutions to rate problems and to suggest equations that offer exact algebraic solutions to the problem. Four problems requiring progressively greater graphing sophistication are presented plus four exercises. (MNS)

  5. Localization in a random XY model with long-range interactions: Intermediate case between single-particle and many-body problems

    NASA Astrophysics Data System (ADS)

    Burin, Alexander L.

    2015-09-01

    Many-body localization in an XY model with a long-range interaction is investigated. We show that in the regime of a high strength of disordering compared to the interaction an off-resonant flip-flop spin-spin interaction (hopping) generates the effective Ising interactions of spins in the third order of perturbation theory in a hopping. The combination of hopping and induced Ising interactions for the power-law distance dependent hopping V (R ) ∝R-α always leads to the localization breakdown in a thermodynamic limit of an infinite system at α <3 d /2 where d is a system dimension. The delocalization takes place due to the induced Ising interactions U (R ) ∝R-2 α of "extended" resonant pairs. This prediction is consistent with the numerical finite size scaling in one-dimensional systems. Many-body localization in an XY model is more stable with respect to the long-range interaction compared to a many-body problem with similar Ising and Heisenberg interactions requiring α ≥2 d which makes the practical implementations of this model more attractive for quantum information applications. The full summary of dimension constraints and localization threshold size dependencies for many-body localization in the case of combined Ising and hopping interactions is obtained using this and previous work and it is the subject for the future experimental verification using cold atomic systems.

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

    NASA Astrophysics Data System (ADS)

    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.

  7. Studies in interactive communication. II - The effects of four communication modes on the linguistic performance of teams during cooperative problem solving

    NASA Technical Reports Server (NTRS)

    Chapanis, A.; Parrish, R. N.; Ochsman, R. B.; Weeks, G. D.

    1977-01-01

    Two-man teams solved credible, 'real world' problems for which computer assistance has been or could be useful. Conversations were carried on in one of four modes of communication: typewriting, handwriting, voice, and natural unrestricted communication. Performance was assessed on three classes of dependent measures: time to solution, behavioral measures of activity, and linguistic measures. Significant differences among the communication modes were found in each of the three classes. This paper is concerned mainly with the results of the linguistic analyses. Linguistic performance was assessed with 182 measures, most of which turned out to be redundant and some of which were useless or meaningless. Those that remain show that although problems can be solved faster in the oral modes than in the hard-copy modes, the oral modes are characterized by many more messages, sentences, words, and unique words; much higher communication rates; but lower type-token ratios. Although a number of significant problem and job-role effects were found, there were relatively few significant interactions of modes with thsse variables. It appears, therefore, that the mode effects hold for both problems and for both job roles assigned to the subjects.

  8. Effect of Stellar Wind and Poynting-Robertson Drag on Photogravitational Elliptic Restricted Three Body Problem

    NASA Astrophysics Data System (ADS)

    Chakraborty, A.; Narayan, A.

    2018-03-01

    The existence and linear stability of the planar equilibrium points for photogravitational elliptical restricted three body problem is investigated in this paper. Assuming that the primaries, one of which is radiating are rotating in an elliptical orbit around their common center of mass. The effect of the radiation pressure, forces due to stellar wind and Poynting-Robertson drag on the dust particles are considered. The location of the five equilibrium points are found using analytical methods. It is observed that the collinear equilibrium points L 1, L 2 and L 3 do not lie on the line joining the primaries but are shifted along the y-coordinate. The instability of the libration points due to the presence of the drag forces is demonstrated by Lyapunov's first method of stability.

  9. Food insecurity is associated with past and present economic disadvantage and body mass index.

    PubMed

    Sarlio-Lähteenkorva, S; Lahelma, E

    2001-11-01

    Fears and experiences of food restriction influence eating behavior but the association between past and present economic disadvantage, food insecurity and body size is poorly understood. Therefore, we examined these associations in a nationwide, representative sample of 25- to 64-y-old Finnish men and women (n = 6506). The respondents were classified by their body mass index (BMI) into four groups: thin, normal, overweight and obese. Economic disadvantage was assessed by three indicators including low household income, unemployment during past 5 y and long-term economic problems in childhood. Food insecurity was assessed by five separate items concerning economic fears and experiences related to sufficient supply of food during the past 12 mo, and a combined scale in which those with affirmative responses to four to five items were classified as hungry. Multivariable logistic regression analyses were conducted using both the BMI grouping and indicators of economic disadvantage as independent variables to predict food insecurity, controlling simultaneously for age, educational attainment and sex. The results showed that low household income, recent unemployment and economic problems in childhood were all predictors of food insecurity. Thin people were most likely to be hungry and showed most food insecurity in five separate items. In addition, obese people reported more buying cheaper food due to economic problems and fears or experiences of running out of money to buy food than did normal weight subjects. In conclusion, both past and present economic disadvantage is associated with various aspects of food insecurity. The association between food insecurity and BMI is curvilinear.

  10. Orbits of Two-Body Problem From the Lenz Vector

    ERIC Educational Resources Information Center

    Caplan, S.; And Others

    1978-01-01

    Obtains the orbits with reference to the center of mass of two bodies under mutual universe square law interaction by use of the eccentricity vector which is equivalent to the Lenz vector within a numerical factor. (Author/SL)

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

    PubMed Central

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

    2017-01-01

    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

  12. Senses of body image in adolescents in elementary school

    PubMed Central

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

    2014-01-01

    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. PMID:25119938

  13. Senses of body image in adolescents in elementary school.

    PubMed

    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.

  14. An adapted, four-week mind-body skills group for medical students: reducing stress, increasing mindfulness, and enhancing self-care.

    PubMed

    Greeson, Jeffrey M; Toohey, Michael J; Pearce, Michelle J

    2015-01-01

    Despite the well-known stress of medical school, including adverse consequences for mental and behavioral health, there is little consensus about how to best intervene in a way that accommodates students׳ intense training demands, interest in science, and desire to avoid being stigmatized. The objective of this study, therefore, was to evaluate the feasibility, acceptability, and initial effectiveness of an adapted, four-week stress management and self-care workshop for medical students, which was based on the science and practice of mind-body medicine. The current study used a prospective, observational, and mixed methods design, with pretest and posttest evaluations. Participants (n = 44) included medical and physician-scientist (MD/PhD) students from a large, southeastern medical school. Feasibility was assessed by rates of workshop enrollment and completion. Acceptability was assessed using qualitative ratings and open-ended responses that queried perceived value of the workshop. Quantitative outcomes included students׳ ratings of stress and mindfulness using validated self-report surveys. Enrollment progressively increased from 6 to 15 to 23 students per workshop in 2007, 2009, and 2011, respectively. Of the 44 enrolled students, 36 (82%) completed the workshop, indicating that the four-session extracurricular format was feasible for most students. Students reported that the workshop was acceptable, stating that it helped them cope more skillfully with the stress and emotional challenges of medical school, and helped increase self-care behaviors, such as exercise, sleep, and engaging in social support. Students also reported a 32% decrease in perceived stress (P < .001; d = 1.38) and a 16% increase in mindfulness (P < .001; d = 0.92) following the workshop. Changes in stress and mindfulness were significantly correlated (r = -0.42; P = .01). Together, these findings suggest that a brief, voluntary mind-body skills workshop specifically adapted for medical

  15. The Effects of Using Problem-Based Learning in Science and Technology Teaching upon Students' Academic Achievement and Levels of Structuring Concepts

    ERIC Educational Resources Information Center

    Inel, Didem; Balim, Ali Gunay

    2010-01-01

    The present study aimed to investigate the impact of the problem-based learning method used in science and technology teaching upon elementary school students' construction levels for the concepts concerning the "Systems in Our Body" unit in the science and technology course and their academic achievement. To this end, during the four-week…

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

    PubMed

    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

  17. Embedding Game-Based Problem-Solving Phase into Problem-Posing System for Mathematics Learning

    ERIC Educational Resources Information Center

    Chang, Kuo-En; Wu, Lin-Jung; Weng, Sheng-En; Sung, Yao-Ting

    2012-01-01

    A problem-posing system is developed with four phases including posing problem, planning, solving problem, and looking back, in which the "solving problem" phase is implemented by game-scenarios. The system supports elementary students in the process of problem-posing, allowing them to fully engage in mathematical activities. In total, 92 fifth…

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

    PubMed

    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).

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

    PubMed

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

    2015-09-29

    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.

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

    PubMed Central

    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

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

    PubMed

    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 < or = .0005). Ninety (42%) reported piercings, 22 (10%) tattoos, 9 (4%) scarification, and 1 (< 1%) 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

  2. Scaling of Adult Regional Body Mass and Body Composition as a Whole to Height: Relevance to Body Shape and Body Mass Index

    PubMed Central

    Schuna, John M.; Peterson, Courtney M.; Thomas, Diana M.; Heo, Moonseong; Hong, Sangmo; Choi, Woong; Heymsfield, Steven B.

    2015-01-01

    Objectives Adult body mass (MB) empirically scales as height (Ht) squared (MB ∝ Ht2), but does regional body mass and body composition as a whole also scale as Ht2? This question is relevant to a wide range of biological topics, including interpretation of body mass index. Methods Dual-energy x-ray absorptiometry (DXA) was used to quantify regional body mass (head [MH], trunk, arms, legs) and whole-body composition (fat, lean soft tissue [LST], and bone mineral content [BMC]) in non-Hispanic (NH) white, NH black, Mexican American, and Korean adults participating in the National Health and Nutrition Examination Survey (NHANES; n=17,126) and Korean NHANES (n=8,942). Regression models were developed to establish Ht scaling powers for each measured component with adjustments for age and adiposity. Results Exploratory analyses revealed a consistent scaling pattern across men and women of the four race/ethnic groups: regional mass powers, head (~0.8-1) < arms and trunk (~1.8-2.3) < legs (~2.3-2.6); and body composition, LST (~2.0-2.3) < BMC (~2.1-2.4). Small sex and race/ethnic differences in scaling powers were also observed. As body mass scaled uniformly across the eight sex and race/ethnic groups as Ht~2, tall and short subjects differed in body shape (e.g., Mh/Mb ∝ Ht−~1) and composition. Conclusions Adult human body shape and relative composition are a function of body size as defined by stature, a finding that has important implications in multiple areas of biological research. PMID:25381999

  3. Application of the dual-kinetic-balance sets in the relativistic many-body problem of atomic structure

    NASA Astrophysics Data System (ADS)

    Beloy, Kyle; Derevianko, Andrei

    2008-09-01

    The dual-kinetic-balance (DKB) finite basis set method for solving the Dirac equation for hydrogen-like ions [V.M. Shabaev et al., Phys. Rev. Lett. 93 (2004) 130405] is extended to problems with a non-local spherically-symmetric Dirac-Hartree-Fock potential. We implement the DKB method using B-spline basis sets and compare its performance with the widely-employed approach of Notre Dame (ND) group [W.R. Johnson, S.A. Blundell, J. Sapirstein, Phys. Rev. A 37 (1988) 307-315]. We compare the performance of the ND and DKB methods by computing various properties of Cs atom: energies, hyperfine integrals, the parity-non-conserving amplitude of the 6s-7s transition, and the second-order many-body correction to the removal energy of the valence electrons. We find that for a comparable size of the basis set the accuracy of both methods is similar for matrix elements accumulated far from the nuclear region. However, for atomic properties determined by small distances, the DKB method outperforms the ND approach. In addition, we present a strategy for optimizing the size of the basis sets by choosing progressively smaller number of basis functions for increasingly higher partial waves. This strategy exploits suppression of contributions of high partial waves to typical many-body correlation corrections.

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

    NASA Astrophysics Data System (ADS)

    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

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

    ERIC Educational Resources Information Center

    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…

  6. A four-body model for the breakup of Borromean nucleus 22C

    NASA Astrophysics Data System (ADS)

    Miyamoto, Tomokazu

    A Borromean system is a bound 3-body system where no 2-body subsystems are bound. In nuclear physics, a nucleus that can be modelled as a Borromean system is called a Borromean nucleus; 6 He and 11 Li are good examples of this. Recent research suggests that this Borromean nature should also be exhibited by 22 C, the heaviest-known carbon isotope. In this PhD thesis, a schematic approach is taken to study reactions involving Borromean nuclei. Hyperspherical formalism (HH) and coordinate space Faddeev (CSF) method are used for creating their 3-body bound state wave functions. We formulate the reactions of a Borromean nucleus with a stable target at incident energies ranging from tens of (MeV) to a few hundred (MeV); we adopt a 4-body reaction model to deepen our understanding of the reaction mechanism involving Borromean nuclei. The Glauber-WKB framework is used to describe these reactions, which is well-suited for these incident energies. Introducing Watson-Migdal final state interaction, we calculate the E1 strengths for Borromean nuclei so as to elucidate their breakup mechanism and we explore the possibility of the existence of a soft dipole mode. We also calculate the differential breakup cross sections to see how the post-collision interaction can have an impact on the cross sections. As far as 22 C is concerned, it is found that the reactions are mainly focused on the forward angle region, and the contributions from the higher order terms are not significant. This implies that the non-eikonal trajectories do not play a crucial role in the reaction mechanism. Also, both E1 distributions and breakup cross sections seem to sensitive to the 2n-separation energies of the bound state wave functions, but the E1 distributions and the cross sections to 1- continuum state seem not to be sensitive to the FSIs; cross sections to 0+ and 2+ continuum states seem to be sensitive to the FSIs. Our findings does not support the view that, if an soft dipole mode exists, it is

  7. Testosterone replacement therapy to improve secondary sexual characteristics and body composition without adverse behavioral problems in adult male patients with Prader-Willi syndrome: an observational study.

    PubMed

    Kido, Yasuhiro; Sakazume, Satoru; Abe, Yoshiko; Oto, Yuji; Itabashi, Hisashi; Shiraishi, Masahisa; Yoshino, Atsunori; Tanaka, Yuriko; Obata, Kazuo; Murakami, Nobuyuki; Nagai, Toshiro

    2013-09-01

    Prader-Willi syndrome (PWS), a complex genetic disorder, arises from suppressed expression of paternally inherited imprinted genes on chromosome 15q11-q13. Characteristics include short stature, intellectual disability, behavioral problems, hypogonadism, obesity, and reduced bone and muscle mass. Testosterone replacement (TR) remains controversial due to concerns regarding behavioral problems. To evaluate the effects of TR on secondary sexual characteristics, body composition, and behavior in adult males with PWS, 22 male PWS patients over the age of 16 with behavioral scores of less than grade 4 on the Modified Overt Aggression Scale (MOAS) underwent monthly intramuscular TR (125 mg). Pubertal change, body composition and behavior were evaluated before and after 24 months of therapy. Serum testosterone, LH, and FSH did not change. Increased pubic hair was observed in 16 of 22 patients (72.7%). Percent body fat decreased from 47.55 ± 2.06% to 39.75 ± 1.60% (n = 18) (P = 0.018). Bone mineral density increased from 0.8505 ± 0.0426 g/cm(2) to 0.9035 ± 0.0465 g/cm(2) (n = 18) (P = 0.036), and lean body mass increased from 18093.4 ± 863.0 g to 20312.1 ± 1027.2 g (n = 18) (P = 0.009). The MOAS was unchanged, from 4.5 ± 2.0 at the beginning of the study to 3.0 ± 1.7 at the end of study indicating no increase in aggression. No behavioral problems were observed. Based on this pilot study, TR with 125 mg monthly is a potentially safe and useful intervention for adult males with PWS. Copyright © 2013 Wiley Periodicals, Inc.

  8. Body Partonomy: How Children Partition the Human Body.

    ERIC Educational Resources Information Center

    Johnson, Carl Nils; Kendrick, Kimberly

    1984-01-01

    Concepts of body parts and their relationships were assessed in children ages three, four, and five, as well as in adults. Three specific questions were addressed: (1) What do children understand about such "partonomic" relations? (2) Is there an order in the acquisition of partonomic concepts? and (3) Do children exhibit any confusions in their…

  9. NONUNIFORM FOURIER TRANSFORMS FOR RIGID-BODY AND MULTI-DIMENSIONAL ROTATIONAL CORRELATIONS

    PubMed Central

    BAJAJ, CHANDRAJIT; BAUER, BENEDIKT; BETTADAPURA, RADHAKRISHNA; VOLLRATH, ANTJE

    2013-01-01

    The task of evaluating correlations is central to computational structural biology. The rigid-body correlation problem seeks the rigid-body transformation (R, t), R ∈ SO(3), t ∈ ℝ3 that maximizes the correlation between a pair of input scalar-valued functions representing molecular structures. Exhaustive solutions to the rigid-body correlation problem take advantage of the fast Fourier transform to achieve a speedup either with respect to the sought translation or rotation. We present PFcorr, a new exhaustive solution, based on the non-equispaced SO(3) Fourier transform, to the rigid-body correlation problem; unlike previous solutions, ours achieves a combination of translational and rotational speedups without requiring equispaced grids. PFcorr can be straightforwardly applied to a variety of problems in protein structure prediction and refinement that involve correlations under rigid-body motions of the protein. Additionally, we show how it applies, along with an appropriate flexibility model, to analogs of the above problems in which the flexibility of the protein is relevant. PMID:24379643

  10. A penal problem: the increasing incidence of implantation of penile foreign bodies.

    PubMed

    Flynn, Ryan M; Mostafa, Hesham I; Khan, Omar A; Haselhuhn, Gregory D; Jain, Samay

    2014-12-01

    Our objective is to describe a novel presentation of subcutaneous penile insertion of foreign bodies. This is a practice performed globally and mostly has been reported outside of the United States. We present three cases of incarcerated males that implanted sculpted dominos into the penile subcutaneous tissue. The patients presented with erosion of the foreign bodies through the skin without evidence of infection. We believe that insertion of foreign bodies into penile subcutaneous tissue by incarcerated American males for sexual enhancement is more widespread than previously reported. Erosion is a novel presentation.

  11. Whole-body vibration exposure in sport: four relevant cases.

    PubMed

    Tarabini, Marco; Saggin, Bortolino; Scaccabarozzi, Diego

    2015-01-01

    This study investigates the whole-body vibration exposure in kite surfing, alpine skiing, snowboarding and cycling. The vibration exposure was experimentally evaluated following the ISO 2631 guidelines. Results evidenced that the most critical axis is the vertical one. The weighted vibration levels are always larger than 2.5 m/s(2) and the vibration dose values are larger than 25 m/s(1.75). The exposure limit values of the EU directive are reached after 8-37 min depending on the sport. The vibration magnitude is influenced by the athletes' speed, by their skill level and sometimes by the equipment. The large vibration values suggest that the practice of sport activities may be a confounding factor in the aetiology of vibration-related diseases. The vibration exposure in some sports is expected to be large, but has never been quantified in the literature. Results of experiments performed in cycling, alpine and water sports outlined vibration levels exceeding the EU standard limit values.

  12. Attitude and Configuration Control of Flexible Multi-Body Spacecraft

    NASA Astrophysics Data System (ADS)

    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.

  13. Four Day, Forty Hour Week

    ERIC Educational Resources Information Center

    Mackin, Jeanne A.; Cutler, Mary

    1978-01-01

    Managers of the Ithaca College Bookstore have been able to improve service, profit and employee morale by experimenting with a four day, forty hour week. Initial problems in employee adjustment were offset by favorable student response. (JMD)

  14. Four Essential Dimensions of Workplace Learning

    ERIC Educational Resources Information Center

    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…

  15. Macrodystrophia lipomatosa: four case reports

    PubMed Central

    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

  16. The normal electrocardiogram of four species of conscious raptors.

    PubMed

    Talavera, J; Guzmán, M J; del Palacio, M J Fernández; Albert, A P; Bayón, A

    2008-02-01

    The aim of this study was to describe normal ECG patterns and values in four species of conscious raptors (Eurasian kestrel, Griffon vulture, Little owl, and Eurasian Eagle owl). Electrocardiograms were carried out in 75 conscious birds belonging to four species of raptors. Lead II waveforms were analysed to determine amplitudes and durations of waves and intervals. Morphologic patterns of P-QRS-T deflections were analysed in the six limb leads. Rhythm, heart rate, mean electrical axis, presence of Ta wave, ST slurring, and P-on-T phenomenon were also studied. The influence of species, body weight and heart rate in electrocardiographic variables were statistically analysed (P < 0.05). Sinus rhythm was present in all tracings, showing sinus arrhythmia in four cases. Ta wave was present in six tracings and P-on-T phenomenon in four. ST segment could be identified in all tracings, being mainly high above baseline. Significant differences between species were found for all the electrocardiographic parameters. The heart rate and body weight were also found to be a significant influence in most parameters. This study provides electrocardiographic data for four species of raptors that can be used to establish comparisons for clinical purposes.

  17. Word Problem Wizardry.

    ERIC Educational Resources Information Center

    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)

  18. Stability of triangular lagrangian points in elliptical restricted three body problem under the radiating binary systems

    NASA Astrophysics Data System (ADS)

    Narayan, A.; Singh, Nutan

    2014-10-01

    This paper studies the stability of Triangular Lagrangian points in the model of elliptical restricted three body problem, under the assumption that both the primaries are radiating. The model proposed is applicable to the well known binary systems Achird, Luyten, αCen AB, Kruger-60, Xi-Bootis. Conditional stability of the motion around the triangular points exists for 0≤ μ≤ μ ∗, where μ is the mass ratio. The method of averaging due to Grebenikov has been exploited throughout the analysis of stability of the system. The critical mass ratio depends on the combined effects of radiation of both the primaries and eccentricity of this orbit. It is found by adopting the simulation technique that the range of stability decreases as the radiation pressure parameter increases.

  19. The Distortion of a Body's Visible Shape at Relativistic Speeds

    ERIC Educational Resources Information Center

    Arkadiy, Leonov

    2009-01-01

    The problem of obtaining the apparent equation of motion and shape of a moving body from its arbitrary given equation of motion in special relativity is considered. Also the inverse problem of obtaining the body's equation of motion from a known equation of motion of its image is discussed. Some examples of this problem solution are considered. As…

  20. Scaling of adult regional body mass and body composition as a whole to height: Relevance to body shape and body mass index.

    PubMed

    Schuna, John M; Peterson, Courtney M; Thomas, Diana M; Heo, Moonseong; Hong, Sangmo; Choi, Woong; Heymsfield, Steven B

    2015-01-01

    Adult body mass (MB) empirically scales as height (Ht) squared (MB ∝ Ht(2) ), but does regional body mass and body composition as a whole also scale as Ht(2) ? This question is relevant to a wide range of biological topics, including interpretation of body mass index (BMI). Dual-energy X-ray absorptiometry (DXA) was used to quantify regional body mass [head (MH), trunk, arms, and legs] and whole-body composition [fat, lean soft tissue (LST), and bone mineral content (BMC)] in non-Hispanic (NH) white, NH black, Mexican American, and Korean adults participating in the National Health and Nutrition Examination Survey (NHANES; n = 17,126) and Korean NHANES (n = 8,942). Regression models were developed to establish Ht scaling powers for each measured component with adjustments for age and adiposity. Exploratory analyses revealed a consistent scaling pattern across men and women of the four population groups: regional mass powers, head (∼0.8-1) < arms and trunk (∼1.8-2.3) < legs (∼2.3-2.6); and body composition, LST (∼2.0-2.3) < BMC (∼2.1-2.4). Small sex and population differences in scaling powers were also observed. As body mass scaled uniformly across the eight sex and population groups as Ht(∼2) , tall and short subjects differed in body shape (e.g., MH/MB ∝ Ht(-∼1) ) and composition. Adult human body shape and relative composition are a function of body size as represented by stature, a finding that reveals a previously unrecognized phenotypic heterogeneity as defined by BMI. These observations provide new pathways for exploring mechanisms governing the interrelations between adult stature, body morphology, biomechanics, and metabolism. © 2014 Wiley Periodicals, Inc.

  1. Problem Solving Skills for Children.

    ERIC Educational Resources Information Center

    Youngs, Bettie B.

    This guide was written for children, to help them handle problems they might encounter, learn about other children and how they have handled similar problems, and learn what to do when things go wrong or when they feel misunderstood. In the introduction, children are assured that, even when they have problems, they can be happy again. The body of…

  2. Ketone Bodies in Epilepsy

    PubMed Central

    McNally, Melanie A.; Hartman, Adam L.

    2014-01-01

    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. PMID:22268909

  3. Problem solving stages in the five square problem

    PubMed Central

    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. PMID:26300794

  4. Problem solving stages in the five square problem.

    PubMed

    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.

  5. A Keplerian-based Hamiltonian splitting for gravitational N-body simulations

    NASA Astrophysics Data System (ADS)

    Gonçalves Ferrari, G.; Boekholt, T.; Portegies Zwart, S. F.

    2014-05-01

    We developed a Keplerian-based Hamiltonian splitting for solving the gravitational N-body problem. This splitting allows us to approximate the solution of a general N-body problem by a composition of multiple, independently evolved two-body problems. While the Hamiltonian splitting is exact, we show that the composition of independent two-body problems results in a non-symplectic non-time-symmetric first-order map. A time-symmetric second-order map is then constructed by composing this basic first-order map with its self-adjoint. The resulting method is precise for each individual two-body solution and produces quick and accurate results for near-Keplerian N-body systems, like planetary systems or a cluster of stars that orbit a supermassive black hole. The method is also suitable for integration of N-body systems with intrinsic hierarchies, like a star cluster with primordial binaries. The superposition of Kepler solutions for each pair of particles makes the method excellently suited for parallel computing; we achieve ≳64 per cent efficiency for only eight particles per core, but close to perfect scaling for 16 384 particles on a 128 core distributed-memory computer. We present several implementations in SAKURA, one of which is publicly available via the AMUSE framework.

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

    NASA Astrophysics Data System (ADS)

    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.

  7. 45 CFR 1607.4 - Functions of a governing body.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 4 2011-10-01 2011-10-01 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...

  8. 45 CFR 1607.4 - Functions of a governing body.

    Code of Federal Regulations, 2010 CFR

    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...

  9. [Uncommon foreign body in a nose].

    PubMed

    Alagić-Smailbegović, Jasminka; Hadzić, Edina; Sutalo, Kamenko; Resić, Mudzahid

    2007-01-01

    Foreign body in the nose most frequently occurs in childhood. It could be of various origin, pieces of toys, paper and uncommon metal body. Consequences include one- sided nasal breathing problem, nasal secretion and in some cases pain and secretion become purulent. The aim of this paper is to present uncommon foreign body in the nose. RTG diagnosis and extraction are the methods of choice.

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

    PubMed

    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.

  11. Free boundary problems in shock reflection/diffraction and related transonic flow problems

    PubMed Central

    Chen, Gui-Qiang; Feldman, Mikhail

    2015-01-01

    Shock waves are steep wavefronts that are fundamental in nature, especially in high-speed fluid flows. When a shock hits an obstacle, or a flying body meets a shock, shock reflection/diffraction phenomena occur. In this paper, we show how several long-standing shock reflection/diffraction problems can be formulated as free boundary problems, discuss some recent progress in developing mathematical ideas, approaches and techniques for solving these problems, and present some further open problems in this direction. In particular, these shock problems include von Neumann's problem for shock reflection–diffraction by two-dimensional wedges with concave corner, Lighthill's problem for shock diffraction by two-dimensional wedges with convex corner, and Prandtl-Meyer's problem for supersonic flow impinging onto solid wedges, which are also fundamental in the mathematical theory of multidimensional conservation laws. PMID:26261363

  12. Effects on body weight and body composition of a low-dose oral estroprogestin containing ethinyl estradiol 20 microg plus levonorgestrel 100 microg.

    PubMed

    Lello, Stefano; Vittori, Giorgio; Paoletti, Anna Maria; Sorge, Roberto; Guardianelli, Francesca; Melis, Gian Benedetto

    2007-11-01

    Weight gain is a common problem reported by users of estroprogestins (EPs) and is a frequent reason for EP discontinuation, even if this problem is not confirmed in several clinical studies. We studied the impact of a EP containing ethinyl estradiol (EE) 20 microg plus levonorgestrel (LNG) 100 microg on body weight (BW) and body composition in 47 treated women and 31 women as controls. Also, we studied the effect of this association on metabolic parameters (glycemia, lipid profile). EE20/LNG100 had no significant impact on body weight, body composition (fat mass, fat-free mass, total body water, intracellular water, extracellular water) or metabolic profile in comparison with no treatment. Thus, the use of EE20/LNG100 showed no impact on metabolic parameters, body weight and body composition. This could be important not only for the safety profile of this combination, but also in increasing patient compliance.

  13. Shuttle-food consumption, body composition and body weight in women

    NASA Technical Reports Server (NTRS)

    Lane, Helen W.; Frye, Sherrie; Kloeris, Vickie; Rice, Barbara; Siconolfi, Steven F.; Spector, Elisabeth; Gretebeck, Randall J.

    1992-01-01

    An experiment is conducted to determine whether the NASA Space Shuttle food system can provide the food and fluid required to mitigate weight loss and physical decomposition in 12 female subjects for 28 days. Subjects receive only foods from the Space Shuttle system for four weeks within an 11-wk monitoring period. Dual-energy X-ray absorptiometry is employed throughout the trial period to study lean body mass, percent body fat, and energy-intake levels with attention given to differences the experimental diet and the subjects' typical diet. Percent body fat is found to change significantly with losses of less than 0.05 percent, whereas energy intake based on autonomous diet choices by the participants does not vary significantly. Lean body mass remains unchanged throughout the study in which the subjects receive a relatively low-fat and low-protein menu. The 100 items on the space shuttle list of approved food items are shown to provide a palatable dietary framework for maintaining the health of female astronauts.

  14. Body Language.

    ERIC Educational Resources Information Center

    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)

  15. 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.

    PubMed

    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

  16. Simulations of dusty plasmas using a special-purpose computer system designed for gravitational N-body problems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yamamoto, K.; Mizuno, Y.; Hibino, S.

    2006-01-15

    Simulations of dusty plasmas were performed using GRAPE-6, a special-purpose computer designed for gravitational N-body problems. The collective behavior of dust particles, which are injected into the plasma, was studied by means of three-dimensional computer simulations. As an example of a dusty plasma simulation, experiments on Coulomb crystals in plasmas are simulated. Formation of a quasi-two-dimensional Coulomb crystal has been observed under typical laboratory conditions. Another example was to simulate movement of dust particles in plasmas under microgravity conditions. Fully three-dimensional spherical structures of dust clouds have been observed. For the simulation of a dusty plasma in microgravity with 3x10{supmore » 4} particles, GRAPE-6 can perform the whole operation 1000 times faster than by using a Pentium 4 1.6 GHz processor.« less

  17. Three-body effects in Casimir-Polder repulsion

    NASA Astrophysics Data System (ADS)

    Milton, Kimball A.; Abalo, E. K.; Parashar, Prachi; Pourtolami, Nima; Brevik, Iver; Ellingsen, Simen Å.; Buhmann, Stefan Yoshi; Scheel, Stefan

    2015-04-01

    In this paper we study an archetypical scenario in which repulsive Casimir-Polder forces between an atom or molecule and two macroscopic bodies can be achieved. This is an extension of previous studies of the interaction between a polarizable atom and a wedge, in which repulsion occurs if the atom is sufficiently anisotropic and close enough to the symmetry plane of the wedge. A similar repulsion occurs if such an atom passes a thin cylinder or a wire. An obvious extension is to compute the interaction between such an atom and two facing wedges, which includes as a special case the interaction of an atom with a conducting screen possessing a slit, or between two parallel wires. To this end we further extend the electromagnetic multiple-scattering formalism for three-body interactions. To test this machinery we reinvestigate the interaction of a polarizable atom between two parallel conducting plates. In that case, three-body effects are shown to be small and are dominated by three- and four-scattering terms. The atom-wedge calculation is illustrated by an analogous scalar situation, described in the Appendix. The wedge-wedge-atom geometry is difficult to analyze because this is a scale-free problem. However, it is not so hard to investigate the three-body corrections to the interaction between an anisotropic atom or nanoparticle and a pair of parallel conducting cylinders and show that the three-body effects are very small and do not affect the Casimir-Polder repulsion at large distances between the cylinders. Finally, we consider whether such highly anisotropic atoms needed for repulsion are practically realizable. Since this appears rather difficult to accomplish, it may be more feasible to observe such effects with highly anisotropic nanoparticles.

  18. Four Decades of β-Lactam Antibiotic Pharmacokinetics in Cystic Fibrosis.

    PubMed

    Bulitta, Jürgen B; Jiao, Yuanyuan; Drescher, Stefanie K; Oliver, Antonio; Louie, Arnold; Moya, Bartolome; Tao, Xun; Wittau, Mathias; Tsuji, Brian T; Zavascki, Alexandre P; Shin, Beom Soo; Drusano, George L; Sörgel, Fritz; Landersdorfer, Cornelia B

    2018-06-23

    The pharmacokinetics (PK) of β-lactam antibiotics in cystic fibrosis (CF) patients has been compared with that in healthy volunteers for over four decades; however, no quantitative models exist that explain the PK differences between CF patients and healthy volunteers in older and newer studies. Our aims were to critically evaluate these studies and explain the PK differences between CF patients and healthy volunteers. We reviewed all 16 studies that compared the PK of β-lactams between CF patients and healthy volunteers within the same study. Analysis of covariance (ANCOVA) models were developed. In four early studies that compared adolescent, lean CF patients with adult healthy volunteers, clearance (CL) in CF divided by that in healthy volunteers was 1.72 ± 0.90 (average ± standard deviation); in four additional studies comparing age-matched (primarily adult) CF patients with healthy volunteers, this ratio was 1.46 ± 0.16. The CL ratio was 1.15 ± 0.11 in all eight studies that compared CF patients and healthy volunteers who were matched in age, body size and body composition, or that employed allometric scaling by lean body mass (LBM). Volume of distribution was similar between subject groups after scaling by body size. For highly protein-bound β-lactams, the unbound fraction was up to 2.07-fold higher in older studies that compared presumably sicker CF patients with healthy volunteers. These protein-binding differences explained over half of the variance for the CL ratio (p < 0.0001, ANCOVA). Body size, body composition and lower protein binding in presumably sicker CF patients explained the PK alterations in this population. Dosing CF patients according to LBM seems suitable to achieve antibiotic target exposures.

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

    NASA Astrophysics Data System (ADS)

    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.

  20. Body Image, Media, and Eating Disorders

    ERIC Educational Resources Information Center

    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…

  1. Collision Index and Stability of Elliptic Relative Equilibria in Planar {n}-body Problem

    NASA Astrophysics Data System (ADS)

    Hu, Xijun; Ou, Yuwei

    2016-12-01

    It is well known that a planar central configuration of the {n}-body problem gives rise to solutions where each particle moves on a specific Keplerian orbit while the totality of the particles move on a homographic motion. When the eccentricity {e} of the Keplerian orbit belongs in {[0,1)}, following Meyer and Schmidt, we call such solutions elliptic relative equilibria (shortly, ERE). In order to study the linear stability of ERE in the near-collision case, namely when {1-e} is small enough, we introduce the collision index for planar central configurations. The collision index is a Maslov-type index for heteroclinic orbits and orbits parametrised by half-lines that, according to the definition given by Hu and Portaluri (An index theory for unbounded motions of Hamiltonian systems, Hu and Portaluri (2015, preprint)), we shall refer to as half-clinic orbits and whose definition in this context, is essentially based on a blow up technique in the case {e=1}. We get the fundamental properties of collision index and approximation theorems. As applications, we give some new hyperbolic criteria and prove that, generically, the ERE of minimal central configurations are hyperbolic in the near-collision case, and we give a detailed analysis of Euler collinear orbits in the near-collision case.

  2. Detection of water bodies in Saline County, Kansas

    NASA Technical Reports Server (NTRS)

    Barr, B. G. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. A total of 2,272 water bodies were mapped in Saline County, Kansas in 1972 using ERTS-1 imagery. A topographic map of 1955 shows 1,056 water bodies in the county. The major increase took place in farm ponds. Preliminary comparison of image and maps indicates that water bodies larger than ten acres in area proved consistently detectable. Most water areas between four and ten acres are also detectable, although occasionally image context prevents detection. Water areas less than four acres in extent are sometimes detected, but the number varies greatly depending on image context and the individual interpretor.

  3. Ketone bodies in epilepsy.

    PubMed

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  5. Controlling the unruly maternal body: Losing and gaining control over the body during pregnancy and the postpartum period.

    PubMed

    Neiterman, Elena; Fox, Bonnie

    2017-02-01

    This paper examines the feeling of lost control of the body that so many women experience through pregnancy and the postpartum period - why they feel it and how they interpret that feeling - and women's responses to the sense of lost control. For the 63 Canadian women we interviewed, the sense of lost control was related to the degree they felt their bodies changed and the number of physical problems they experienced while pregnant. Many women's references to "luck" as the cause of body changes and problems experienced underscored how little control they felt they had when they were pregnant. At the same time, women felt responsible for the well-being of their babies, and thus experienced guilt about their unruly bodies. Careful attention to diet helped some women, but not others, regain some sense of control; women with past experience of pregnancy who "gave in" to body change were more sanguine. In the postpartum period, body work (especially exercise) functioned to increase women's sense of control, but a variety of motives led them to do this work. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. The impact of anal sphincter injury on perceived body image.

    PubMed

    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.

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

    ERIC Educational Resources Information Center

    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)

  8. Multi-Party, Whole-Body Interactions in Mathematical Activity

    ERIC Educational Resources Information Center

    Ma, Jasmine Y.

    2017-01-01

    This study interrogates the contributions of multi-party, whole-body interactions to students' collaboration and negotiation of mathematics ideas in a task setting called walking scale geometry, where bodies in interaction became complex resources for students' emerging goals in problem solving. Whole bodies took up overlapping roles representing…

  9. An optimization method for the problems of thermal cloaking of material bodies

    NASA Astrophysics Data System (ADS)

    Alekseev, G. V.; Levin, V. A.

    2016-11-01

    Inverse heat-transfer problems related to constructing special thermal devices such as cloaking shells, thermal-illusion or thermal-camouflage devices, and heat-flux concentrators are studied. The heatdiffusion equation with a variable heat-conductivity coefficient is used as the initial heat-transfer model. An optimization method is used to reduce the above inverse problems to the respective control problem. The solvability of the above control problem is proved, an optimality system that describes necessary extremum conditions is derived, and a numerical algorithm for solving the control problem is proposed.

  10. Robot body self-modeling algorithm: a collision-free motion planning approach for humanoids.

    PubMed

    Leylavi Shoushtari, Ali

    2016-01-01

    Motion planning for humanoid robots is one of the critical issues due to the high redundancy and theoretical and technical considerations e.g. stability, motion feasibility and collision avoidance. The strategies which central nervous system employs to plan, signal and control the human movements are a source of inspiration to deal with the mentioned problems. Self-modeling is a concept inspired by body self-awareness in human. In this research it is integrated in an optimal motion planning framework in order to detect and avoid collision of the manipulated object with the humanoid body during performing a dynamic task. Twelve parametric functions are designed as self-models to determine the boundary of humanoid's body. Later, the boundaries which mathematically defined by the self-models are employed to calculate the safe region for box to avoid the collision with the robot. Four different objective functions are employed in motion simulation to validate the robustness of algorithm under different dynamics. The results also confirm the collision avoidance, reality and stability of the predicted motion.

  11. Plane stress problems using hysteretic rigid body spring network models

    NASA Astrophysics Data System (ADS)

    Christos, Sofianos D.; Vlasis, Koumousis K.

    2017-10-01

    In this work, a discrete numerical scheme is presented capable of modeling the hysteretic behavior of 2D structures. Rigid Body Spring Network (RBSN) models that were first proposed by Kawai (Nucl Eng Des 48(1):29-207, 1978) are extended to account for hysteretic elastoplastic behavior. Discretization is based on Voronoi tessellation, as proposed specifically for RBSN models to ensure uniformity. As a result, the structure is discretized into convex polygons that form the discrete rigid bodies of the model. These are connected with three zero length, i.e., single-node springs in the middle of their common facets. The springs follow the smooth hysteretic Bouc-Wen model which efficiently incorporates classical plasticity with no direct reference to a yield surface. Numerical results for both static and dynamic loadings are presented, which validate the proposed simplified spring-mass formulation. In addition, they verify the model's applicability on determining primarily the displacement field and plastic zones compared to the standard elastoplastic finite element method.

  12. Three dimensional modeling and dynamic analysis of four-wheel-steering vehicles

    NASA Astrophysics Data System (ADS)

    Hu, Haiyan; Han, Qiang

    2003-02-01

    The paper presents a nonlinear dynamic model of 9 degrees of freedom for four-wheel-steering vehicles. Compared with those in previous studies, this model includes the pitch and roll of the vehicle body, the motion of 4 wheels in the accelerating or braking process, the nonlinear coupling of vehicle body and unsprung part, as well as the air drag and wind effect. As a result, the model can be used for the analysis of various maneuvers of the four-wheel-steering vehicles. In addition, the previous models can be considered as a special case of this model. The paper gives some case studies for the dynamic performance of a four-wheel-steering vehicle under step input and saw-tooth input of steering angle applied on the front wheels, respectively.

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

    NASA Astrophysics Data System (ADS)

    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.

  14. Small Business Management and Ownership. Volume Four. Mini-Problems in Entrepreneurship.

    ERIC Educational Resources Information Center

    Shuchat, Jo

    The mini-problems presented in this volume are provided to augment the introductory course, "Minding Your Own Small Business," and the advanced course, "Something Ventured, Something Gained," in small business ownership and management. They can also be used in conjunction with other instructional materials in small business…

  15. Uniqueness of First Order Post-Newtonian Collinear Solutions for Three-Body Problem under a Scalar-Tensor Theory

    NASA Astrophysics Data System (ADS)

    Cao, Wei-Guang; Zhou, Tian-Yi; Xie, Yi

    2017-10-01

    As a continuing investigation of an earlier work that establishes the collinear solutions to the three-body problem with general masses under a scalar-tensor theory, we study these solutions and prove their uniqueness up to the first order post-Newtonian approximation. With the help of observed bounds on the scalar field in the Solar System, we show that the seventh-order polynomial equation determining the distance ratio among the three masses has either one or three positive roots. However, in the case with three positive roots, it is found that two positive roots break down the slow-motion condition for the post-Newtonian approximation so that only one positive root is physically valid. The resulting uniqueness suggests that the locations of the three masses are very close to their Newtonian positions with post-Newtonian corrections of general relativity and the scalar field. We also prove that, in the framework of the scalar-tensor theory, the angular velocity of the collinear configuration is always less than the Newtonian one when all other parameters are fixed. These results are valid only for three-body systems where upper-bounds on the scalar field are compatible with those of the Solar System. Supported by the National Natural Science Foundation of China under Grant Nos. 11573015 and J1210039, and the Innovation Training Project for Undergraduates of Nanjing University, China

  16. Few-body resonances of unequal-mass systems with infinite interspecies two-body s-wave scattering length

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Blume, D.; Daily, K. M.

    Two-component Fermi and Bose gases with infinitely large interspecies s-wave scattering length a{sub s} exhibit a variety of intriguing properties. Among these are the scale invariance of two-component Fermi gases with equal masses, and the favorable scaling of Efimov features for two-component Bose gases and Bose-Fermi mixtures with unequal masses. This paper builds on our earlier work [Phys. Rev. Lett. 105, 170403 (2010)] and presents a detailed discussion of our studies of small unequal-mass two-component systems with infinite a{sub s} in the regime where three-body Efimov physics is absent. We report on nonuniversal few-body resonances. Just like with two-body systemsmore » on resonance, few-body systems have a zero-energy bound state in free space and a diverging generalized scattering length. Our calculations are performed within a nonperturbative microscopic framework and investigate the energetics and structural properties of small unequal-mass two-component systems as functions of the mass ratio {kappa}, and the numbers N{sub 1} and N{sub 2} of heavy and light atoms. For purely attractive Gaussian two-body interactions, we find that the (N{sub 1},N{sub 2})=(2,1) and (3,1) systems exhibit three-body and four-body resonances at mass ratios {kappa}=12.314(2) and 10.4(2), respectively. The three- and four-particle systems on resonance are found to be large. It seems feasible that the features discussed in this paper can be probed experimentally with present-day technology.« less

  17. Obesity and body image.

    PubMed

    Schwartz, Marlene B; Brownell, Kelly D

    2004-01-01

    Modern western culture emphasizes thinness, denigrates excess weight, and stigmatizes obese individuals, making it likely that obese people internalize these messages and feel badly about the physical presence that brands them. There is clear evidence that obesity is linked with poor body image, but not all obese persons suffer from this problem or are equally vulnerable. Risk factors identified thus far are degree of overweight, being female, and binge eating, with some evidence of risk increasing with early age of onset of obesity, race, and several additional factors. Treatments do exist for improving body image in overweight individuals. Key questions are how to identify those in need of body image intervention, how such programs can be integrated with weight loss treatments, and ultimately, how body image distress can be prevented.

  18. Discrete optimal control approach to a four-dimensional guidance problem near terminal areas

    NASA Technical Reports Server (NTRS)

    Nagarajan, N.

    1974-01-01

    Description of a computer-oriented technique to generate the necessary control inputs to guide an aircraft in a given time from a given initial state to a prescribed final state subject to the constraints on airspeed, acceleration, and pitch and bank angles of the aircraft. A discrete-time mathematical model requiring five state variables and three control variables is obtained, assuming steady wind and zero sideslip. The guidance problem is posed as a discrete nonlinear optimal control problem with a cost functional of Bolza form. A solution technique for the control problem is investigated, and numerical examples are presented. It is believed that this approach should prove to be useful in automated air traffic control schemes near large terminal areas.

  19. Investigating Adolescent Stress and Body Image

    ERIC Educational Resources Information Center

    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…

  20. Asymptotic solution of the problem for a thin axisymmetric cavern

    NASA Technical Reports Server (NTRS)

    Serebriakov, V. V.

    1973-01-01

    The boundary value problem which describes the axisymmetric separation of the flow around a body by a stationary infinite stream is considered. It is understood that the cavitation number varies over the length of the cavern. Using the asymptotic expansions for the potential of a thin body, the orders of magnitude of terms in the equations of the problem are estimated. Neglecting small quantities, a simplified boundary value problem is obtained.

  1. Body image, media, and eating disorders.

    PubMed

    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.

  2. Reconstruction phases in the planar three- and four-vortex problems

    NASA Astrophysics Data System (ADS)

    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.

  3. Patient-Reported Outcomes in Weight Loss and Body Contouring Surgery: A Cross-Sectional Analysis Using the BODY-Q.

    PubMed

    Poulsen, Lotte; Klassen, Anne; Rose, Michael; Roessler, Kirsten K; Juhl, Claus Bogh; Støving, René Klinkby; Sørensen, Jens Ahm

    2017-09-01

    Health-related quality of life and satisfaction with appearance are important outcomes in bariatric and body contouring surgery. To investigate these outcomes, scientifically sound and clinically meaningful patient-reported outcome instruments are needed. The authors measured health-related quality of life and appearance in a cohort of Danish patients at different phases in the weight loss journey: before bariatric surgery, after bariatric surgery, before body contouring surgery, and after body contouring surgery. From June of 2015 to June of 2016, a cross-sectional sample of 493 bariatric and body contouring patients were recruited from four different hospital departments. Patients were asked to fill out the BODY-Q, a new patient-reported outcomes instrument designed specifically to measure health-related quality of life and appearance over the entire patient journey, from obesity to the post-body contouring surgery period. Data were collected using REDCap, and analyzed using SPSS software. For all appearance and health-related quality-of-life scales, the mean score was significantly lower in the pre-bariatric surgery group compared with the post-body contouring group. Furthermore, the correlation between body mass index and mean scores was significant for all appearance and health-related quality-of-life scales, with higher scores associated with lower body mass index. The mean score for the group reporting no excess skin compared with the group reporting a lot of excess skin was significantly higher for five of seven appearance scales and four of five health-related quality-of-life scales. This study provides evidence to suggest that body contouring plays an important role in the weight loss patient's journey and that patients need access to treatments.

  4. Energy Harvesting Based Body Area Networks for Smart Health.

    PubMed

    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.

  5. Energy Harvesting Based Body Area Networks for Smart Health

    PubMed Central

    Hao, Yixue; Peng, Limei; Alamri, Atif

    2017-01-01

    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. PMID:28698501

  6. Global geometry of non-planar 3-body motions

    NASA Astrophysics Data System (ADS)

    Salehani, Mahdi Khajeh

    2011-12-01

    The aim of this paper is to study the global geometry of non-planar 3-body motions in the realms of equivariant Differential Geometry and Geometric Mechanics. This work was intended as an attempt at bringing together these two areas, in which geometric methods play the major role, in the study of the 3-body problem. It is shown that the Euler equations of a three-body system with non-planar motion introduce non-holonomic constraints into the Lagrangian formulation of mechanics. Applying the method of undetermined Lagrange multipliers to study the dynamics of three-body motions reduced to the level of moduli space {bar{M}} subject to the non-holonomic constraints yields the generalized Euler-Lagrange equations of non-planar three-body motions in {bar{M}} . As an application of the derived dynamical equations in the level of {bar{M}} , we completely settle the question posed by A. Wintner in his book [The analytical foundations of Celestial Mechanics, Sections 394-396, 435 and 436. Princeton University Press (1941)] on classifying the constant inclination solutions of the three-body problem.

  7. The relevance of the philosophical 'mind-body problem' for the status of psychosomatic medicine: a conceptual analysis of the biopsychosocial model.

    PubMed

    Van Oudenhove, Lukas; Cuypers, Stefaan

    2014-05-01

    Psychosomatic medicine, with its prevailing biopsychosocial model, aims to integrate human and exact sciences with their divergent conceptual models. Therefore, its own conceptual foundations, which often remain implicit and unknown, may be critically relevant. We defend the thesis that choosing between different metaphysical views on the 'mind-body problem' may have important implications for the conceptual foundations of psychosomatic medicine, and therefore potentially also for its methods, scientific status and relationship with the scientific disciplines it aims to integrate: biomedical sciences (including neuroscience), psychology and social sciences. To make this point, we introduce three key positions in the philosophical 'mind-body' debate (emergentism, reductionism, and supervenience physicalism) and investigate their consequences for the conceptual basis of the biopsychosocial model in general and its 'psycho-biological' part ('mental causation') in particular. Despite the clinical merits of the biopsychosocial model, we submit that it is conceptually underdeveloped or even flawed, which may hamper its use as a proper scientific model.

  8. Bacterial body plans

    PubMed Central

    Rieger, Tomáš; Neubauer, Zdeněk; Blahůšková, Anna; Cvrčková, Fatima

    2008-01-01

    The bacterium Serratia marcescens produces a plethora of multicellular shapes of different colorations on solid substrates, allowing immediate visual detection of varieties. Such a plasticity allows studies on multicellular community scale spanning two extremes, from well-elaborated individual colonies to undifferentiated cell mass. For a single strain and medium, we obtained a range of different multicellular bodies, depending on the layout of initial plating. Four principal factors affecting the morphogenetic pathways of such bodies can be distinguished: (1) amount, density and distribution pattern of founder cells; (2) the configuration of surrounding free medium; (3) the presence and character of other bacterial bodies sharing the same niche; and (4) self-perception, resulting in delimitation towards other bodies. The last feature results in an ability of well-formed multicellular individuals to maintain their identity upon a close mutual contact, as well as in spontaneous separation of cell masses in experimental chimeras. We propose an “embryo-like” colony model where multicellular bacterial bodies develop along genuine ontogenetic pathways inherent to the given species (clone), while external shaping forces (like nutrient gradients, pH, etc.,) exert not formative, but only regulative roles in the process. PMID:19513204

  9. Management of foreign body ingestion and food bolus impaction in children: a retrospective analysis of 675 cases.

    PubMed

    Antoniou, Dimitris; Christopoulos-Geroulanos, George

    2011-01-01

    Although foreign body ingestion is a common problem in children, there are no clear guidelines regarding the management of ingested foreign bodies. The aim of this study was to evaluate the effectiveness of our protocol in the work-up and management of children with ingested foreign bodies. Between September 2002 and August 2010, a total of 675 children with suspected foreign body ingestion were seen in the emergency department. At initial presentation, the majority of foreign bodies were located in the stomach (n=392, 58.1%) followed by the small intestine (n=221, 32.7%) and esophagus (n=62, 9.2%). Based on our protocol, 84 (12.4%) patients were admitted at initial presentation, and 5 after a 48-hour observation period at home; 61 (9%) required prompt endoscopic removal. Sixty-eight (10.1%) patients returned for endoscopic removal after a four-week observation period, and 3 (0.4%) patients underwent delayed surgery due to complications. The overall success rate of endoscopic retrieval was 96.1%. There were no major complications. The majority of ingested foreign bodies will pass spontaneously and most children can be safely observed at home. Selective endoscopic intervention is the preferable method for the removal of ingested foreign bodies in pediatric patients.

  10. Processes involved in solving mathematical problems

    NASA Astrophysics Data System (ADS)

    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.

  11. Mind-body. Monistic dual aspect interactionism.

    PubMed

    Wallace, E R

    1988-01-01

    It is difficult to imagine a more perennially vexing topic to philosophers, scientists, and physicians than the mind-body problem. Recent literature bears out its continued vital interest for psychiatrists. This article briefly recapitulates the major perspectives on the problem, examines the relationship of meaning and mind to psychosocial and biological explanatory programs and to materiality, and promotes a monistic dual aspect interactionist approach to mind and body in health and illness. From this thesis conclusions are drawn in regard to the ultimate possibility of a psychiatric unitary field theory, the question of the autonomy of the psychological and biological explanatory programs, and the identity of the psychiatrist.

  12. Body Type Attractiveness Preferences of the Aged.

    ERIC Educational Resources Information Center

    Portnoy, Enid J.

    A study explored the relationship between body types and four attraction dimensions (physical, social, task, and communication) as perceived by older adults (mean age 68). Subjects, 35 males and 73 females in private residences and senior citizen centers, were shown three same-sex body silhouettes representing the older ectomorph, mesomorph, and…

  13. Computer simulation of multigrid body dynamics and control

    NASA Technical Reports Server (NTRS)

    Swaminadham, M.; Moon, Young I.; Venkayya, V. B.

    1990-01-01

    The objective is to set up and analyze benchmark problems on multibody dynamics and to verify the predictions of two multibody computer simulation codes. TREETOPS and DISCOS have been used to run three example problems - one degree-of-freedom spring mass dashpot system, an inverted pendulum system, and a triple pendulum. To study the dynamics and control interaction, an inverted planar pendulum with an external body force and a torsional control spring was modeled as a hinge connected two-rigid body system. TREETOPS and DISCOS affected the time history simulation of this problem. System state space variables and their time derivatives from two simulation codes were compared.

  14. Learning Problems and Classroom Instruction.

    ERIC Educational Resources Information Center

    Adelman, Howard S.

    Defined are categories of learning disabilities (LD) that can be remediated in regular public school classes, and offered are remedial approaches. Stressed in four studies is the heterogeneity of LD problems. Suggested is grouping LD children into three categories: no disorder (problem is from the learning environment); minor disorder (problem is…

  15. Is BodyThink an efficacious body image and self-esteem program? A controlled evaluation with adolescents.

    PubMed

    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.

  16. The Compound Atwood Machine Problem

    ERIC Educational Resources Information Center

    Coelho, R. Lopes

    2017-01-01

    The present paper accounts for progress in physics teaching in the sense that a problem, which has been closed to students for being too difficult, is gained for the high school curriculum. This problem is the compound Atwood machine with three bodies. Its introduction into high school classes is based on a recent study on the weighing of an…

  17. High-energy gravitational scattering and the general relativistic two-body problem

    NASA Astrophysics Data System (ADS)

    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.

  18. Body Image in Primary Schools: A pilot evaluation of a primary school intervention program designed by teachers to improve children's body satisfaction.

    PubMed

    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.

  19. An impacting linear three body system

    NASA Astrophysics Data System (ADS)

    Nordmark, Arne; Essén, Hanno

    2018-01-01

    We study a system of three identical bodies that can move freely on a horizontal track. Initially one body moves and two are at rest. The moving body impacts with one of the resting bodies which then impacts with the third and so on. The impacts are assumed to be characterised by a coefficient of restitution. We investigate the total number of impacts, the final velocities of the bodies, and the final energy of the system in terms of the initial velocity and the coefficient of restitution. The problem, which originates from mechanics textbooks, can be analysed as a discrete dynamical system with three degrees of freedom. The full solution is more subtle that one might expect.

  20. Cross- and triple-ratios of human body parts during development.

    PubMed

    Lundh, Torbjörn; Udagawa, Jun; Hänel, Sven-Erik; Otani, Hiroki

    2011-08-01

    Recently developed landmark-based geometric morphometry has been used to depict the morphological development of organisms. In geometry, four landmarks can be mapped to any other four by Möbius transformations, if the cross-ratio of the landmarks is invariant and vice versa. To geometrically analyze the morphological development of the human body, we examined the cross-ratio of three consecutive body parts that are segmented by four landmarks in their configuration. Moreover, we introduced the triple-ratio of five landmarks that segments four consecutive parts (e.g., the shoulder, upper arm, forearm, and hand) and examined their growth patterns. The cross- and triple-ratios of the upper limb and shoulder girdle in fetuses were constant when biomechanical landmarks were used, although the cross-ratio of the upper limb varied when anatomical landmarks were used. The cross-ratios of the lower limbs, trunk, and pelvic girdles in fetuses differed from their corresponding cross-ratios in adults. These results suggest Möbius growth in the fetal upper limb and shoulder girdle but not in the other body parts examined. However, the growth balance of the three contiguous body parts was represented by the developmental change in the cross-ratio. Therefore, the cross- and triple-ratios may be applicable for simple but significant assessments of growth balance or proportion of the body parts. Copyright © 2011 Wiley-Liss, Inc.

  1. Tidal disruption of solid bodies

    NASA Technical Reports Server (NTRS)

    Dobrovolskis, Anthony R.

    1990-01-01

    The problem of stress, strain, and breakup in solid satellites and stray bodies subject to tidal perturbations is presently addressed in view of three novel considerations. After presenting a new analytic solution for the stress tensor in a homogeneous and compressible elastic sphere, where the inclusion of compressibility alters stresses by several percent, realistic failure criteria are noted to demonstrate the general failure of such ductile bodies as iron meteoroids by plastic shear, while brittle ice bodies fail by either tensile or shear fracture. A reexamination of crack propagation after initial failure allows the diverse breakup criteria to be reconciled.

  2. Inclusive Breakup Theory of Three-Body Halos

    NASA Astrophysics Data System (ADS)

    Hussein, Mahir S.; Souza, Lucas A.; Chimanski, Emanuel; Carlson, Brett; Frederico, Tobias

    2017-11-01

    We present a recently developed theory for the inclusive breakup of three-fragment projectiles within a four-body spectator model [1], for the treatment of the elastic and inclusive non-elastic break up reactions involving weakly bound three-cluster nuclei in A (a; b) X / a = x1 + x2 + b collisions. The four-body theory is an extension of the three-body approaches developed in the 80's by Ichimura, Autern and Vincent (IAV) [2], Udagawa and Tamura (UT) [3] and Hussein and McVoy (HM) [4]. We expect that experimentalists shall be encouraged to search for more information about the x1 + x2 system in the elastic breakup cross section and that also further developments and extensions of the surrogate method will be pursued, based on the inclusive non-elastic breakup part of the b spectrum.

  3. Origin and continuation of 3/2, 5/2, 3/1, 4/1 and 5/1 resonant periodic orbits in the circular and elliptic restricted three-body problem

    NASA Astrophysics Data System (ADS)

    Antoniadou, Kyriaki I.; Libert, Anne-Sophie

    2018-06-01

    We consider a planetary system consisting of two primaries, namely a star and a giant planet, and a massless secondary, say a terrestrial planet or an asteroid, which moves under their gravitational attraction. We study the dynamics of this system in the framework of the circular and elliptic restricted three-body problem, when the motion of the giant planet describes circular and elliptic orbits, respectively. Originating from the circular family, families of symmetric periodic orbits in the 3/2, 5/2, 3/1, 4/1 and 5/1 mean-motion resonances are continued in the circular and the elliptic problems. New bifurcation points from the circular to the elliptic problem are found for each of the above resonances, and thus, new families continued from these points are herein presented. Stable segments of periodic orbits were found at high eccentricity values of the already known families considered as whole unstable previously. Moreover, new isolated (not continued from bifurcation points) families are computed in the elliptic restricted problem. The majority of the new families mainly consists of stable periodic orbits at high eccentricities. The families of the 5/1 resonance are investigated for the first time in the restricted three-body problems. We highlight the effect of stable periodic orbits on the formation of stable regions in their vicinity and unveil the boundaries of such domains in phase space by computing maps of dynamical stability. The long-term stable evolution of the terrestrial planets or asteroids is dependent on the existence of regular domains in their dynamical neighbourhood in phase space, which could host them for long-time spans. This study, besides other celestial architectures that can be efficiently modelled by the circular and elliptic restricted problems, is particularly appropriate for the discovery of terrestrial companions among the single-giant planet systems discovered so far.

  4. 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

    PubMed Central

    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. PMID:28234931

  5. 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.

    PubMed

    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.

  6. Final Four Offers NCAA Respite from Criticism

    ERIC Educational Resources Information Center

    Sander, Libby

    2009-01-01

    When it's not staging any Final Four match-ups, the National Collegiate Athletic Association (NCAA) is the powerful governing body critics love to hate. The association's 11-year, $6-billion contract with CBS to televise the tournament has become a lightning rod for critics who say the association is all about making money off athletes. Not so,…

  7. Decomposing Large Inverse Problems with an Augmented Lagrangian Approach: Application to Joint Inversion of Body-Wave Travel Times and Surface-Wave Dispersion Measurements

    NASA Astrophysics Data System (ADS)

    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.

  8. Direct Multiple Shooting Optimization with Variable Problem Parameters

    NASA Technical Reports Server (NTRS)

    Whitley, Ryan J.; Ocampo, Cesar A.

    2009-01-01

    Taking advantage of a novel approach to the design of the orbital transfer optimization problem and advanced non-linear programming algorithms, several optimal transfer trajectories are found for problems with and without known analytic solutions. This method treats the fixed known gravitational constants as optimization variables in order to reduce the need for an advanced initial guess. Complex periodic orbits are targeted with very simple guesses and the ability to find optimal transfers in spite of these bad guesses is successfully demonstrated. Impulsive transfers are considered for orbits in both the 2-body frame as well as the circular restricted three-body problem (CRTBP). The results with this new approach demonstrate the potential for increasing robustness for all types of orbit transfer problems.

  9. The structural and content aspects of abstracts versus bodies of full text journal articles are different

    PubMed Central

    2010-01-01

    Background 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. Results 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. Conclusions 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

  10. The compound Atwood machine problem

    NASA Astrophysics Data System (ADS)

    Lopes Coelho, R.

    2017-05-01

    The present paper accounts for progress in physics teaching in the sense that a problem, which has been closed to students for being too difficult, is gained for the high school curriculum. This problem is the compound Atwood machine with three bodies. Its introduction into high school classes is based on a recent study on the weighing of an Atwood machine.

  11. Parental perceptions of children's body shapes.

    PubMed

    Zalilah, M S; Anida, H A; Merlin, Ang

    2003-12-01

    The aim was to determine the differences in parents' perceptions of boys' and girls' body shapes and the explanations for the emphasis on body shape care of children. Subjects were low-income parents (n = 158) of preschoolers attending preschools in Kuala Lumpur, Malaysia. Parental perceptions of children's body shapes were assessed based on their rankings (scale of 1 to 7) of four attributes (ideal, healthy, fat and thin) for boy and girl figures. Parental responses to five questions on the importance of body shape were also obtained. Parental rankings of ideal and healthy body shapes were significantly lower for girls than boys (p < 0.001). However, mothers' and fathers' rankings of boys' and girls' body shapes were not significantly different. for both boys and girls, parental ratings for ideal body shape were significantly lower than for healthy body shape (p < 0.001). The majority of parents indicated that children's body shape is important for their future health, self enhancement, social interaction and career. With the increasing prevalence of body dissatisfaction among Malaysian children, these findings contribute to the understanding of parental roles in the development of body image and perhaps, in the etiology of body dissatisfaction among children.

  12. Use of Invariant Manifolds for Transfers Between Three-Body Systems

    NASA Technical Reports Server (NTRS)

    Beckman, Mark; Howell, Kathleen

    2003-01-01

    The Lunar L1 and L2 libration points have been proposed as gateways granting inexpensive access to interplanetary space. To date, only individual solutions to the transfer between three-body systems have been found. The methodology to solve the problem for arbitrary three-body systems and entire families of orbits does not exist. This paper presents the initial approaches to solve the general problem for single and multiple impulse transfers. Two different methods of representing and storing 7-dimensional invariant manifold data are presented. Some particular solutions are presented for the transfer problem, though the emphasis is on developing methodology for solving the general problem.

  13. Representations of Invariant Manifolds for Applications in Three-Body Systems

    NASA Technical Reports Server (NTRS)

    Howell, K.; Beckman, M.; Patterson, C.; Folta, D.

    2004-01-01

    The Lunar L1 and L2 libration points have been proposed as gateways granting inexpensive access to interplanetary space. To date, only individual solutions to the transfer between three-body systems have been found. The methodology to solve the problem for arbitrary three-body systems and entire families of orbits is currently being studied. This paper presents an initial approach to solve the general problem for single and multiple impulse transfers. Two different methods of representing and storing the invariant manifold data are presented. Some particular solutions are presented for two types of transfer problems, though the emphasis is on developing the methodology for solving the general problem.

  14. Application of remote sensing to water resources problems

    NASA Technical Reports Server (NTRS)

    Clapp, J. L.

    1972-01-01

    The following conclusions were reached concerning the applications of remote sensing to water resources problems: (1) Remote sensing methods provide the most practical method of obtaining data for many water resources problems; (2) the multi-disciplinary approach is essential to the effective application of remote sensing to water resource problems; (3) there is a correlation between the amount of suspended solids in an effluent discharged into a water body and reflected energy; (4) remote sensing provides for more effective and accurate monitoring, discovery and characterization of the mixing zone of effluent discharged into a receiving water body; and (5) it is possible to differentiate between blue and blue-green algae.

  15. Retained Textile Foreign Bodies: Experience of 27 Years.

    PubMed

    Arikan, Soykan; Kocakusak, Ahmet

    2015-01-01

    Retained intracorporeal textile products (gossypiboma-textiloma) are undesired and accidental surgical results for both patients and surgeons, which are underreported because of medicolegal remifications. Fourteen textiloma cases, who had been treated or whose treatment procedures had been followed-up personally by two general surgeons in a period of 27 years almost during their whole professional lives were presented to describe and define the clinical and pathological characteristics. Patient characteristics including gender and age, areas of location within the body, time intervals until diagnosis, clinical presentations and complaints, treatment modalities, complications, causative surgical interventions, and diagnostic approaches were retrospectively evaluated. Nine female and five male patients with a mean age of 43.07 ± 15.23 (median: 45) years at diagnosis were enrolled in the study. Cesarean section in three, inguinal hernioraphy in four, explorative laparotomy because of acute abdomen in one, sigmoid colon resection in one, appendectomy and right salpingoophorectomy in one, etrangulated incisional hernia after a previous surgical intervention because of an ovarian mass in one, thyroidectomy in one, epigastric hernioraphy in one, and bilateral segmental mastectomy with bilateral axillary sentinal lymph node dissection in one were the causative surgical interventions. Locations of textilomas were the abdominal cavity in seven, inguinal surgical wound in four, epigastric surgical wound in one, thyroidectomy lodge in one, and bilateral axillary cavities in one patient. The mean time interval until diagnosis was 14.48 (median: 5.5) months. Earlier recognition of foreign bodies can provide a better outcome. Gossypibomas are preventable iatrogenic faults which create severe problems. Strict adherence to the rules of the operation room is a must to keep the tip of the iceberg shut in the Pandora's box.

  16. Noninvasive, three-dimensional full-field body sensor for surface deformation monitoring of human body in vivo

    NASA Astrophysics Data System (ADS)

    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.

  17. Estimating a child's age from an image using whole body proportions.

    PubMed

    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.

  18. Flyby Characterization of Lower-Degree Spherical Harmonics Around Small Bodies

    NASA Technical Reports Server (NTRS)

    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.

  19. Vortex/Body Interaction and Sound Generation in Low-Speed Flow

    NASA Technical Reports Server (NTRS)

    Kao, Hsiao C.

    1998-01-01

    The problem of sound generation by vortices interacting with an arbitrary body in a low-speed flow has been investigated by the method of matched asymptotic expansions. For the purpose of this report, it is convenient to divide the problem into three parts. In the first part the mechanism of the vortex/body interaction, which is essentially the inner solution in the inner region, is examined. The trajectories for a system of vortices rotating about their centroid are found to undergo enormous changes after interaction; from this, some interesting properties emerged. In the second part, the problem is formulated, the outer solution is found, matching is implemented, and solutions for acoustic pressure are obtained. In the third part, Fourier integrals are evaluated and predicated results presented. An examination of these results reveals the following: (a) the background noise can be either augmented or attenuated by a body after interaction, (b) sound generated by vortex/body interaction obeys a scaling factor, (C) sound intensity can be reduced substantially by positioning the vortex system in the "favorable" side of the body instead of the "unfavorable" side, and (d) acoustic radiation from vortex/bluff-body interaction is less than that from vortex/airfoil interaction under most circumstances.

  20. Body Satisfaction and Physical Appearance in Gender Dysphoria.

    PubMed

    van de Grift, Tim C; Cohen-Kettenis, Peggy T; Steensma, Thomas D; De Cuypere, Griet; Richter-Appelt, Hertha; Haraldsen, Ira R H; Dikmans, Rieky E G; Cerwenka, Susanne C; Kreukels, Baudewijntje P C

    2016-04-01

    Gender dysphoria (GD) is often accompanied by dissatisfaction with physical appearance and body image problems. The aim of this study was to compare body satisfaction with perceived appearance by others in various GD subgroups. Data collection was part of the European Network for the Investigation of Gender Incongruence. Between 2007 and 2012, 660 adults who fulfilled the criteria of the DSM-IV gender identity disorder diagnosis (1.31:1 male-to-female [MtF]:female-to-male [FtM] ratio) were included into the study. Data were collected before the start of clinical gender-confirming interventions. Sexual orientation was measured via a semi-structured interview whereas onset age was based on clinician report. Body satisfaction was assessed using the Body Image Scale. Congruence of appearance with the experienced gender was measured by means of a clinician rating. Overall, FtMs had a more positive body image than MtFs. Besides genital dissatisfaction, problem areas for MtFs included posture, face, and hair, whereas FtMs were mainly dissatisfied with hip and chest regions. Clinicians evaluated the physical appearance to be more congruent with the experienced gender in FtMs than in MtFs. Within the MtF group, those with early onset GD and an androphilic sexual orientation had appearances more in line with their gender identity. In conclusion, body image problems in GD go beyond sex characteristics only. An incongruent physical appearance may result in more difficult psychological adaptation and in more exposure to discrimination and stigmatization.

  1. Swimsuit issues: promoting positive body image in young women's magazines.

    PubMed

    Boyd, Elizabeth Reid; Moncrieff-Boyd, Jessica

    2011-08-01

    This preliminary study reviews the promotion of healthy body image to young Australian women, following the 2009 introduction of the voluntary Industry Code of Conduct on Body Image. The Code includes using diverse sized models in magazines. A qualitative content analysis of the 2010 annual 'swimsuit issues' was conducted on 10 Australian young women's magazines. Pictorial and/or textual editorial evidence of promoting diverse body shapes and sizes was regarded as indicative of the magazines' upholding aspects of the voluntary Code of Conduct for Body Image. Diverse sized models were incorporated in four of the seven magazines with swimsuit features sampled. Body size differentials were presented as part of the swimsuit features in three of the magazines sampled. Tips for diverse body type enhancement were included in four of the magazines. All magazines met at least one criterion. One magazine displayed evidence of all three criteria. Preliminary examination suggests that more than half of young women's magazines are upholding elements of the voluntary Code of Conduct for Body Image, through representation of diverse-sized women in their swimsuit issues.

  2. Collis-Romberg Mathematical Problem Solving Profiles.

    ERIC Educational Resources Information Center

    Collis, K. F.; Romberg, T. A.

    Problem solving has become a focus of mathematics programs in Australia in recent years, necessitating the assessment of students' problem-solving abilities. This manual provides a problem-solving assessment and teaching resource package containing four elements: (1) profiles assessment items; (2) profiles diagnostic forms for recording individual…

  3. The externally corrected coupled cluster approach with four- and five-body clusters from the CASSCF wave function.

    PubMed

    Xu, Enhua; Li, Shuhua

    2015-03-07

    An externally corrected CCSDt (coupled cluster with singles, doubles, and active triples) approach employing four- and five-body clusters from the complete active space self-consistent field (CASSCF) wave function (denoted as ecCCSDt-CASSCF) is presented. The quadruple and quintuple excitation amplitudes within the active space are extracted from the CASSCF wave function and then fed into the CCSDt-like equations, which can be solved in an iterative way as the standard CCSDt equations. With a size-extensive CASSCF reference function, the ecCCSDt-CASSCF method is size-extensive. When the CASSCF wave function is readily available, the computational cost of the ecCCSDt-CASSCF method scales as the popular CCSD method (if the number of active orbitals is small compared to the total number of orbitals). The ecCCSDt-CASSCF approach has been applied to investigate the potential energy surface for the simultaneous dissociation of two O-H bonds in H2O, the equilibrium distances and spectroscopic constants of 4 diatomic molecules (F2(+), O2(+), Be2, and NiC), and the reaction barriers for the automerization reaction of cyclobutadiene and the Cl + O3 → ClO + O2 reaction. In most cases, the ecCCSDt-CASSCF approach can provide better results than the CASPT2 (second order perturbation theory with a CASSCF reference function) and CCSDT methods.

  4. Programming and Problem Solving.

    ERIC Educational Resources Information Center

    Elias, Barbara P.

    A study was conducted to examine computer programming as a problem solving activity. Thirteen fifth grade children were selected by their teacher from an above average class to use Apple IIe microcomputers. The investigator conducted sessions of 40-50 minutes with the children in groups of two or three. Four problems, incorporating the programming…

  5. A numerical projection technique for large-scale eigenvalue problems

    NASA Astrophysics Data System (ADS)

    Gamillscheg, Ralf; Haase, Gundolf; von der Linden, Wolfgang

    2011-10-01

    We present a new numerical technique to solve large-scale eigenvalue problems. It is based on the projection technique, used in strongly correlated quantum many-body systems, where first an effective approximate model of smaller complexity is constructed by projecting out high energy degrees of freedom and in turn solving the resulting model by some standard eigenvalue solver. Here we introduce a generalization of this idea, where both steps are performed numerically and which in contrast to the standard projection technique converges in principle to the exact eigenvalues. This approach is not just applicable to eigenvalue problems encountered in many-body systems but also in other areas of research that result in large-scale eigenvalue problems for matrices which have, roughly speaking, mostly a pronounced dominant diagonal part. We will present detailed studies of the approach guided by two many-body models.

  6. Design in Four Diagnostic Language Assessments

    ERIC Educational Resources Information Center

    Cumming, Alister

    2015-01-01

    The studies documented in the four articles in this special issue uniquely exemplify principles of design-based research as follows: by taking innovative approaches to significant problems in the contexts of real educational practices; by addressing fundamental pedagogical and policy issues related to language, learning, and teaching; and, in the…

  7. Three-Dimensional Dose Calculation for Total Body Irradiation

    NASA Astrophysics Data System (ADS)

    Ito, Akira

    Bone Marrow Transplant (BMT) therapy has been a big success in the treatment of leukemia and other haematopoietic diseases 1 . Prior to BMT, total body irradiation (TBI) is given to the patient for the purpose of (1) killing leukemia cells in bone marrow, as well as in the whole body, and (2) producing immuno-suppressive status in the patient so that the donor's marrow cells will be transplanted without rejection. TBI employs a very large field photon beam to irradiate the whole body of the patient. A uniform dose distribution over the entire body is the treatment goal. To prevent the occurrence of a serious side effect (interstitial pneumonia), the lung dose should not exceed a certain level. This novel technique poses various new radiological physics problems. The accurate assessment of dose and dose distribution in the patient is essential. Physical and dosimetric problems associated with TBI are reviewed elsewhere 2,3 .

  8. The Million-Body Problem: Particle Simulations in Astrophysics

    ScienceCinema

    Rasio, Fred

    2018-05-21

    Computer simulations using particles play a key role in astrophysics. They are widely used to study problems across the entire range of astrophysical scales, from the dynamics of stars, gaseous nebulae, and galaxies, to the formation of the largest-scale structures in the universe. The 'particles' can be anything from elementary particles to macroscopic fluid elements, entire stars, or even entire galaxies. Using particle simulations as a common thread, this talk will present an overview of computational astrophysics research currently done in our theory group at Northwestern. Topics will include stellar collisions and the gravothermal catastrophe in dense star clusters.

  9. 45. Aerial view of station in 1944, four years after ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. Aerial view of station in 1944, four years after automation and before construction of the parking lot.U.S. Coast Guard (USCG) Photo - Bodie Island Light Station, Off Highway 12, Nags Head, Dare County, NC

  10. Long-Term Outcomes of Innovative Curricular Tracks Used in Four Countries.

    ERIC Educational Resources Information Center

    Suwanwela, Charas; And Others

    1993-01-01

    Innovative medical school programs discussed include a problem-based, village-centered rural program in the Philippines, a problem-oriented rural program of community medicine in Thailand, a problem-based curriculum in China, and four restructured medical curricula in the United States. Focus is on the results of the changes. (MSE)

  11. GRAPE-4: A special-purpose computer for gravitational N-body problems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Makino, Junichiro; Taiji, Makoto; Ebisuzaki, Toshikazu

    1995-12-01

    We describe GRAPE-4, a special-purpose computer for gravitational N-body simulations. In gravitational N-body simulations, almost all computing time is spent for the calculation of interaction between particles. GRAPE-4 is a specialized hardware to calculate the interaction between particles. It is used with a general-purpose host computer that performs all calculations other than the force calculation. With this architecture, it is relatively easy to realize a massively parallel system. In 1991, we developed the GRAPE-3 system with the peak speed equivalent to 14.4 Gflops. It consists of 48 custom pipelined processors. In 1992 we started the development of GRAPE-4. The GRAPE-4more » system will consist of 1920 custom pipeline chips. Each chip has the speed of 600 Mflops, when operated on 30 MHz clock. A prototype system with two custom LSIs has been completed July 1994, and the full system is now under manufacturing.« less

  12. Relation of attitude toward body elimination to parenting style and attitude toward the body.

    PubMed

    Corgiat, Claudia A; Templer, Donald I

    2003-04-01

    The purpose was to estimate the relation of attitude toward body elimination in 93 college students (27 men and 66 women), to authoritarian personality features, participants' perception of their mothers' parenting style, and attitudes toward cleanliness, sex, and family nudity. Subjects were administered the Body Elimination Attitude Scale, the Four-item F Scale, the Parental Authority Questionnaire Pertaining to Mothers, and the items "Sex is dirty," "Cleanliness is next to godliness," and "Children should never see other family members nude." Larger scores for disgust toward body elimination were associated with authoritarian personality characteristics, being less likely to describe mother's parenting style as authoritative (open communication) and more likely to describe it as authoritarian and lower scores for tolerance for family nudity. Implications for further research were suggested.

  13. A Synchronous Multi-Body Sensor Platform in a Wireless Body Sensor Network: Design and Implementation

    PubMed Central

    Gil, Yeongjoon; Wu, Wanqing; Lee, Jungtae

    2012-01-01

    Background Human life can be further improved if diseases and disorders can be predicted before they become dangerous, by correctly recognizing signals from the human body, so in order to make disease detection more precise, various body-signals need to be measured simultaneously in a synchronized manner. Object This research aims at developing an integrated system for measuring four signals (EEG, ECG, respiration, and PPG) and simultaneously producing synchronous signals on a Wireless Body Sensor Network. Design We designed and implemented a platform for multiple bio-signals using Bluetooth communication. Results First, we developed a prototype board and verified the signals from the sensor platform using frequency responses and quantities. Next, we designed and implemented a lightweight, ultra-compact, low cost, low power-consumption Printed Circuit Board. Conclusion A synchronous multi-body sensor platform is expected to be very useful in telemedicine and emergency rescue scenarios. Furthermore, this system is expected to be able to analyze the mutual effects among body signals. PMID:23112605

  14. Polynomial expansions of single-mode motions around equilibrium points in the circular restricted three-body problem

    NASA Astrophysics Data System (ADS)

    Lei, Hanlun; Xu, Bo; Circi, Christian

    2018-05-01

    In this work, the single-mode motions around the collinear and triangular libration points in the circular restricted three-body problem are studied. To describe these motions, we adopt an invariant manifold approach, which states that a suitable pair of independent variables are taken as modal coordinates and the remaining state variables are expressed as polynomial series of them. Based on the invariant manifold approach, the general procedure on constructing polynomial expansions up to a certain order is outlined. Taking the Earth-Moon system as the example dynamical model, we construct the polynomial expansions up to the tenth order for the single-mode motions around collinear libration points, and up to order eight and six for the planar and vertical-periodic motions around triangular libration point, respectively. The application of the polynomial expansions constructed lies in that they can be used to determine the initial states for the single-mode motions around equilibrium points. To check the validity, the accuracy of initial states determined by the polynomial expansions is evaluated.

  15. Application of the dual-kinetic-balance sets in the relativistic many-body problem of atomic structure

    NASA Astrophysics Data System (ADS)

    Beloy, Kyle; Derevianko, Andrei

    2008-05-01

    The dual-kinetic-balance (DKB) finite basis set method for solving the Dirac equation for hydrogen-like ions [V. M. Shabaev et al., Phys. Rev. Lett. 93, 130405 (2004)] is extended to problems with a non-local spherically-symmetric Dirac-Hartree-Fock potential. We implement the DKB method using B-spline basis sets and compare its performance with the widely- employed approach of Notre Dame (ND) group [W.R. Johnson, S.A. Blundell, J. Sapirstein, Phys. Rev. A 37, 307-15 (1988)]. We compare the performance of the ND and DKB methods by computing various properties of Cs atom: energies, hyperfine integrals, the parity-non-conserving amplitude of the 6s1/2-7s1/2 transition, and the second-order many-body correction to the removal energy of the valence electrons. We find that for a comparable size of the basis set the accuracy of both methods is similar for matrix elements accumulated far from the nuclear region. However, for atomic properties determined by small distances, the DKB method outperforms the ND approach.

  16. 21 CFR 900.4 - Standards for accreditation bodies.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... image quality, or upon request by FDA, the accreditation body shall review a facility's clinical images... review by the accreditation body demonstrates that a problem does exist with respect to image quality or... program shall: (i) Include requirements for clinical image review and phantom image review; (ii) Ensure...

  17. 21 CFR 900.4 - Standards for accreditation bodies.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... image quality, or upon request by FDA, the accreditation body shall review a facility's clinical images... review by the accreditation body demonstrates that a problem does exist with respect to image quality or... program shall: (i) Include requirements for clinical image review and phantom image review; (ii) Ensure...

  18. 21 CFR 900.4 - Standards for accreditation bodies.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... image quality, or upon request by FDA, the accreditation body shall review a facility's clinical images... review by the accreditation body demonstrates that a problem does exist with respect to image quality or... program shall: (i) Include requirements for clinical image review and phantom image review; (ii) Ensure...

  19. 21 CFR 900.4 - Standards for accreditation bodies.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... image quality, or upon request by FDA, the accreditation body shall review a facility's clinical images... review by the accreditation body demonstrates that a problem does exist with respect to image quality or... program shall: (i) Include requirements for clinical image review and phantom image review; (ii) Ensure...

  20. Body-related behaviours and cognitions: relationship to eating psychopathology in non-clinical women and men.

    PubMed

    Meyer, Caroline; McPartlan, Lauren; Rawlinson, Anthony; Bunting, Jo; Waller, Glenn

    2011-10-01

    Eating disturbances and poor body image are maintained by body-related safety behaviours and their associated cognitions. These include body checking, avoidance, comparison and display, which can be seen as safety behaviours, maintaining eating pathology and poor body image. It is not clear from the existing literature whether these behavioural and cognitive patterns are independently related to eating psychopathology. This study of a non-clinical group of women and men (N = 250) explored the association of eating attitudes and behaviours with these four elements of body-related behaviours and cognitions. It was found that each of the four elements had independent associations with eating attitudes and behaviours. Those associations were not explained by anxiety or depression levels. Whilst these findings require study within a clinical group, they suggest that all four elements of body-related behaviours and cognitions need to be considered as potential maintaining factors when formulating eating psychopathology and body image disturbance.

  1. A study analysis of cable-body systems totally immersed in a fluid stream

    NASA Technical Reports Server (NTRS)

    Delaurier, J. D.

    1972-01-01

    A general stability analysis of a cable-body system immersed in a fluid stream is presented. The analytical portion of this analysis treats the system as being essentially a cable problem, with the body dynamics giving the end conditions. The mathematical form of the analysis consists of partial differential wave equations, with the end and auxiliary conditions being determined from the body equations of motion. The equations uncouple to give a lateral problem and a longitudinal problem as in first order airplane dynamics. A series of tests on a tethered wind tunnel model provide a comparison of the theory with experiment.

  2. Estimation of skeletal muscle mass from body creatine content

    NASA Technical Reports Server (NTRS)

    Pace, N.; Rahlmann, D. F.

    1982-01-01

    Procedures have been developed for studying the effect of changes in gravitational loading on skeletal muscle mass through measurements of the body creatine content. These procedures were developed for studies of gravitational scale effects in a four-species model, comprising the hamster, rat, guinea pig, and rabbit, which provides a sufficient range of body size for assessment of allometric parameters. Since intracellular muscle creatine concentration varies among species, and with age within a given species, the concentration values for metabolically mature individuals of these four species were established. The creatine content of the carcass, skin, viscera, smooth muscle, and skeletal muscle was determined for each species. In addition, the skeletal muscle mass of the major body components was determined, as well as the total and fat-free masses of the body and carcass, and the percent skeletal muscle in each. It is concluded that these procedures are particularly useful for studying the effect of gravitational loading on the skeletal muscle content of the animal carcass, which is the principal weight-bearing organ of the body.

  3. Students' Errors in Solving the Permutation and Combination Problems Based on Problem Solving Steps of Polya

    ERIC Educational Resources Information Center

    Sukoriyanto; Nusantara, Toto; Subanji; Chandra, Tjang Daniel

    2016-01-01

    This article was written based on the results of a study evaluating students' errors in problem solving of permutation and combination in terms of problem solving steps according to Polya. Twenty-five students were asked to do four problems related to permutation and combination. The research results showed that the students still did a mistake in…

  4. Historical epistemology of the body-mind interaction in psychiatry

    PubMed Central

    Berrios, German E.

    2018-01-01

    This paper deals with the history of the relationship between the mind-body dualism and the epistemology of madness. Earlier versions of such dualism posed little problem in regard to the manner of their communication. The Cartesian view that mind and body did, in fact, name different substances introduced a problem of incommunicability that is yet to be resolved. Earlier views that madness may be related to changes in the brain began gaining empirical support during the 17th century. Writers on madness chose to resolve the mind-body problem differently Some stated that such communication was not needed; others, that mind was a redundant concept, as madness could be fully explained by structural changes in the brain; and yet others described psychological spaces for madness to inhabit as a symbolic conflict. The epistemology of the neurosciences bypasses the conundrum, as it processes all together the variables representing the brain, subjectivity, and behavior and bridges the “philosophical” gap by means of correlational structures. PMID:29946206

  5. Comparison of dosimetric properties among four commercial multi-detector computed tomography scanners.

    PubMed

    Ohno, Takeshi; Araki, Fujio; Onizuka, Ryota; Hatemura, Masahiro; Shimonobou, Toshiaki; Sakamoto, Takashi; Okumura, Shuichiro; Ideguchi, Daichi; Honda, Keiichi; Kawata, Kenji

    2017-03-01

    This study compared dosimetric properties among four commercial multi-detector CT (MDCT) scanners. The X-ray beam characteristics were obtained from photon intensity attenuation curves of aluminum and off-center ratio (OCR) profiles in air, which were measured with four commercial MDCT scanners. The absorbed dose for MDCT scanners was evaluated with Farmer ionization chamber measurements at the center and four peripheral points in the body- and head-type cylindrical water phantoms. Measured collected charge was converted to absorbed dose using a 60 Co absorbed dose-to-water calibration factor and Monte Carlo (MC)-calculated correction factors. Four MDCT scanners were modeled to correspond with measured X-ray beam characteristics using GMctdospp (IMPS, Germany) software. Al half-value layers (Al-HVLs) with a body-bowtie filter determined from measured Al-attenuation curves ranged 7.2‒9.1mm at 120kVp and 6.1‒8.0mm at 100kVp. MC-calculated Al-HVLs and OCRs in air were in acceptable agreement within 0.5mm and 5% of measured values, respectively. The percentage difference between nominal and actual beam width was greater with decreasing collimation width. The absorbed doses for MDCT scanners at 120kVp ranged 5.1‒7.1mGy and 10.8‒17.5mGy per 100mAs at the center in the body- and head-type water phantoms, respectively. Measured doses at four peripheral points were within 5% agreement of MC-calculated values. The absorbed dose at the center in both water phantoms increased with decreasing Al-HVL for the same charge on the focus. In this study the X-ray beam characteristics and the absorbed dose were measured and compared with calculated values for four MDCT scanners. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  6. Model of the discrete destruction process of a solid body

    NASA Astrophysics Data System (ADS)

    Glagolev, V. V.; Markin, A. A.

    2018-03-01

    Destruction is considered as a discrete thermomechanical process, in which the deformation of a solid body is achieved by changing the boundary stresses acting on the part of the volume being destroyed with the external load unchanged. On the basis of the proposed concept, a model for adhesive stratification of a composite material is constructed. When adhesive stratification is used, the stress state of one or two boundaries of the adhesive layer changes to zero if the bonds with the joined body are broken. As a result of the stratification, the interaction between the part of the composite, which may include an adhesive layer and the rest of the body stops. When solving the elastoplastic problem of cohesive stratification, the region in which the destruction criterion is achieved is identified. With the help of a repeated solution of the problem of subcritical deformation with the known law of motion of the boundary of the region, the distribution of the load (nodal forces) acting from the region to the body is located. The next step considers the change in the stress–strain state of the body in the process of destruction of the selected area. The elastoplastic problem is solved with a simple unloading of the formed surface of the body and preservation of the external load corresponding to the beginning of the process of destruction.

  7. Measurement of the branching ratios of D(+) and D(+)(s) hadronic decays to four-body final states containing a K(S).

    PubMed

    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

    2001-10-15

    We have studied hadronic four-body decays of D(+) and D(+)(s) mesons with a K(S) 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 gamma(D(+)-->K(S)K-pi(+)pi(+))/gamma(D(+)-->K(S)pi(+)pi(+)pi(-)) = 0.0768+/-0.0041+/-0.0032. We make the first observation of three new decay modes with branching ratios gamma(D(+)-->K(S)K+pi(+)pi(-))/gamma(D(+)-->K(S)pi(+)pi(+)pi(-)) = 0.0562+/-0.0039+/-0.0040, gamma(D(+)-->K(S)K+K-pi(+))/gamma(D(+)-->K(S)pi(+)pi(+)pi(-)) = 0.0077+/-0.0015+/-0.0009, and gamma(D(+)(s)-->K(S)K+pi(+)pi(-))/gamma(D(+)(s)-->K(S)K-pi(+)pi(+)) = 0.586+/-0.052+/-0.043, where in each case the first error is statistical and the second error is systematic.

  8. Foreign bodies in tracheobronchial tree in children: a review of cases over a twenty-year period.

    PubMed

    Yeh, L C; Li, H Y; Huang, T S

    1998-03-01

    Foreign body inhalation into the tracheobronchial tree of children is rather rare but serious problem. It may be hazardous and even cause fatal sequelae in the children if misdiagnosed and not managed promptly. We retrospectively reviewed the records of 81 patients with foreign bodies inhaled into the larynx, trachea and bronchi. The children were all treated during the 20-year period from July 1976 through June 1996 at Chang Gung Memorial Hospital. Of these patients, 82% were 36 months of age or younger. The male to female ratio was 3:1. All of the patients initially received flexible fiberoptic bronchoscopy to identify the foreign objects. The foreign bodies were removed by jet ventilation bronchoscopy with apneic techniques under general anesthesia. Peanuts were found to be the most common causative foreign body agent which occurred in 53 instances (65%). The most common manifestation was coughing, with subsequent dyspnea and audible wheezing. The foreign bodies were lodged in the left bronchus more than in the right. The most obvious radiologic evidence observed in aspirated children were emphysematous changes at same side of the foreign bodies caused by "expansile check-valve" phenomenon. Four patients showed radio-opaque objects on chest roentgenograms. Six patients required second extraction procedures due to the retained foreign bodies. Neither serious complications nor deaths occurred in these patients due to the foreign body inhalation. Early diagnosis and management is essential in children with foreign bodies in the airways to prevent morbidity or death. Small materials or food bits should be kept far away from young child.

  9. Noninvasive, three-dimensional full-field body sensor for surface deformation monitoring of human body in vivo.

    PubMed

    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. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  10. Thermoplasticity of coupled bodies in the case of stress-dependent heat transfer

    NASA Technical Reports Server (NTRS)

    Kilikovskaya, O. A.

    1987-01-01

    The problem of the thermal stresses in coupled deformable bodies is formulated for the case where the heat-transfer coefficient at the common boundary depends on the stress-strain state of the bodies (e.g., is a function of the normal pressure at the common boundary). Several one-dimensional problems are solved in this formulation. Among these problems is the determination of the thermal stresses in an n-layer plate and in a two-layer cylinder.

  11. Ego-pathology, body experience, and body psychotherapy in chronic schizophrenia.

    PubMed

    Röhricht, Frank; Papadopoulos, Nina; Suzuki, Iris; Priebe, Stefan

    2009-03-01

    In a recent pilot RCT, looking at the efficacy of body oriented psychological therapy (BPT) in patients with chronic schizophrenia, a marked improvement in negative symptoms was found in the treatment group. To date, there have been no studies to evaluate the therapeutic processes, correlates and predictors of change in-patients receiving BPT. The aims of this study are to address three specific questions, namely how: (1) Ego-pathology and (2) Body experiences, may change during the treatment (BPT). We also looked at: (3) If these pathologies, and/or changes in them, or other characteristics are associated with specific clinical outcomes. Analysis of data obtained within a pilot randomized controlled trial. In a sample of patients with a diagnosis of chronic schizophrenia, allocated to receive a course of body oriented group psychotherapy, certain parameters were assessed pre- and post-treatment: (1) Ego-pathology, using the ego-pathology inventory (EPI); (2) Body experiences, (size perception/image marking procedure - IMP, body image/body distortion questionnaire - BDQ, and body cathexis/visual-analogue-scales - VAS); and (3) Common symptom factors, using the Positive And Negative Symptom Scale (PANSS). Subjective experiences were also recorded. Four out of six ego-pathology symptom scores improved over the course of therapy (t=2.9-3.5, p<.05-.01). Amongst the measures of body experiences, only the body perception indices of the lower extremities changed significantly from underestimation pre-therapy (BPI median 92.3), becoming accurate estimates post therapy (BPI median 101.1). Contrary to the hypothesis a reduction of negative symptoms in chronic schizophrenia patients was not associated with systematic improvements of ego-pathology or body experiences. The strongest predictor of change was a high score of ego-demarcation pre-treatment (beta=0.89, p<.001). In patients with chronic schizophrenia, body oriented psychological interventions may be effective for both

  12. Railway vehicle body structures

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    1985-01-01

    The strength and durability of railway vehicle structures is a major topic of engineering research and design. To reflect this importance the Railway Division of the Institution of Mechanical Engineers organised a conference to discuss all matters relating to railway vehicle design. This book presents the papers discussed in that conference. The contents include: Vehicle body design and the UIC's international contribution; LUL prototype 1986 stock - body structure; vehicle structure for the intermediate capacity transmit system vehicles; car body technology of advanced light rapid transit vehicles; concepts, techniques and experience in the idealization of car body structures for finitemore » element analysis; Calcutta metropolitan railway; design for a lightweight diesel multiple unit body; the design of lightweight inter-city coal structures; the BREL international coach body shell structure; new concepts and design techniques versus material standards; structures of BR diesel electric freight locomotives; structural design philosophy for electric locomotives; suspension design for a locomotive with low structural frequencies; freight wagon structures; a finite element study of coal bodyside panels including the effects of joint flexibility; a fresh approach to the problem of car body design strength; energy absorption in automatic couplings and draw gear; passenger vehicle design loads and structural crashworthiness; design of the front part of railway vehicles (in case of frontal impact); the development of a theoretical technique for rail vehicle structural crashworthiness.« less

  13. Three-body affairs in the outer solar system

    NASA Astrophysics Data System (ADS)

    Funato, Yoko; Makino, Junichiro; Hut, Piet; Kokubo, Eiichiro; Kinoshita, Daisuke

    Recent observations have revealed an unexpectedly high binary fraction among the Trans-Neptunian Objects (TNOs) that populate the Kuiper Belt. The TNO binaries are strikingly different from asteroid binaries in four respects: their frequency is an order of magnitude larger, the mass ratio of their components is closer to unity, and their orbits are wider and highly eccentric. Two explanations have been proposed for their formation, one assuming large numbers of massive bodies, and one assuming large numbers of light bodies. We argue that both assumptions are unwarranted, and we show how TNO binaries can be produced from a modest number of intermediate-mass bodies of the type predicted by the gravitational instability theory for the formation of planetesimals. We start with a TNO binary population similar to the asteroid binary population, but subsequently modified by three-body exchange reactions, a process that is far more efficient in the Kuiper belt, because of the much smaller tidal perturbations by the Sun. Our mechanism can naturally account for all four characteristics that distinguish TNO binaries from main-belt asteroid binaries.

  14. Celestial mechanics - Methods of the theory of motion of 'artificial' celestial bodies

    NASA Astrophysics Data System (ADS)

    Duboshin, G. N.

    This book is concerned with the translational motion of 'artificial' celestial bodies. The difference between natural celestial bodies, which are ordinarily considered by celestial mechanics, and 'artificial' celestial bodies is discussed, taking into account hypothetical celestial bodies introduced in connection with mathematical developments and problems, invisible celestial bodies whose existence can be assumed on the basis of some plausible hypothesis, and man-made satellites of the earth. The book consists of two parts. The first part presents introductory material, and examines a number of general mathematical questions to provide a basis for the studies conducted in the second part. Subjects considered in the first part are related to basic problems, integration methods, and perturbation theory. In the second part, attention is given to the motion of artificial celestial bodies in the gravitational field of the basic planet, external perturbations regarding the motion of these bodies, the motion of the bodies in the earth-moon system, and periodic solutions.

  15. Dating of sediments from four Swiss prealpine lakes with (210)Pb determined by gamma-spectrometry: progress and problems.

    PubMed

    Putyrskaya, V; Klemt, E; Röllin, S; Astner, M; Sahli, H

    2015-07-01

    In this paper the most important problems in dating lake sediments with unsupported (210)Pb are summarized and the progress in gamma-spectrometry of the unsupported (210)Pb is discussed. The main topics of these studies concern sediment samples preparation for gamma-spectrometry, measurement techniques and data analysis, as well as understanding of accumulation and sedimentation processes in lakes. The vertical distributions of artificial ((137)Cs, (241)Am, (239)Pu) and natural radionuclides ((40)K, (210,214)Pb, (214)Bi) as well as stable trace elements (Fe, Mn, Pb) in sediment cores from four Swiss lakes were used as examples for the interpretation, inter-comparison and validation of depth-age relations established by three (210)Pb-based models (CF-CSR, CRS and SIT). The identification of turbidite layers and the influence of the turbidity flows on the accuracy of sediment dating is demonstrated. Time-dependent mass sedimentation rates in lakes Brienz, Thun, Biel and Lucerne are discussed and compared with published data. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Body fat assessed from body density and estimated from skinfold thickness in normal children and children with cystic fibrosis.

    PubMed

    Johnston, J L; Leong, M S; Checkland, E G; Zuberbuhler, P C; Conger, P R; Quinney, H A

    1988-12-01

    Body density and skinfold thickness at four sites were measured in 140 normal boys, 168 normal girls, and 6 boys and 7 girls with cystic fibrosis, all aged 8-14 y. Prediction equations for the normal boys and girls for the estimation of body-fat content from skinfold measurements were derived from linear regression of body density vs the log of the sum of the skinfold thickness. The relationship between body density and the log of the sum of the skinfold measurements differed from normal for the boys and girls with cystic fibrosis because of their high body density even though their large residual volume was corrected for. However the sum of skinfold measurements in the children with cystic fibrosis did not differ from normal. Thus body fat percent of these children with cystic fibrosis was underestimated when calculated from body density and invalid when calculated from skinfold thickness.

  17. Translanguaging and the Body

    ERIC Educational Resources Information Center

    Blackledge, Adrian; Creese, Angela

    2017-01-01

    This article reports communicative interactions with a focus on the body as a dimension of the semiotic repertoire. The research context is a four-year, multi-site linguistic ethnography which investigates how people communicate in superdiverse cities in the UK. In the setting of a butcher's stall in a city market we consider three interactions at…

  18. Incidence of health problems associated with tattooed skin: a nation-wide survey in German-speaking countries.

    PubMed

    Klügl, Ines; Hiller, Karl-Anton; Landthaler, Michael; Bäumler, Wolfgang

    2010-08-01

    Millions of people are tattooed. However, the frequency of health problems is unknown. We performed an Internet survey in German-speaking countries. The provenance of tattooed participants (n = 3,411) was evenly distributed in Germany. The participants had many (28%; >4) and large tattoos (36%; >or=900 cm(2)). After tattooing, the people described skin problems (67.5%) or systemic reactions (6.6%). Four weeks after tattooing, 9% still had health problems. Six percent reported persistent health problems due to the tattoo, of which females (7.3%) were more frequently concerned than males (4.2%). Colored tattoos provoked more short-term skin (p = 0.003) or systemic (p = 0.0001) reactions than black tattoos. Also the size of tattoos and the age at the time of tattooing play a significant role in many health problems. Our results show that millions of people in the Western world supposedly have transient or persisting health problems after tattooing. Owing to the large number and size of the tattoos, tattooists inject several grams of tattoo colorants into the skin, which partly spread in the human body and stay for a lifetime. The latter might cause additional health problems in the long term. Copyright 2010 S. Karger AG, Basel.

  19. Additional Insights Into Problem Definition and Positioning From Social Science Comment on "Four Challenges That Global Health Networks Face".

    PubMed

    Quissell, Kathryn

    2017-09-10

    Commenting on a recent editorial in this journal which presented four challenges global health networks will have to tackle to be effective, this essay discusses why this type of analysis is important for global health scholars and practitioners, and why it is worth understanding and critically engaging with the complexities behind these challenges. Focusing on the topics of problem definition and positioning, I outline additional insights from social science theory to demonstrate how networks and network researchers can evaluate these processes, and how these processes contribute to better organizing, advocacy, and public health outcomes. This essay also raises multiple questions regarding these processes for future research. © 2018 The Author(s); Published by Kerman University of Medical Sciences. This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

  20. Analytic Theory and Control of the Motion of Spinning Rigid Bodies

    NASA Technical Reports Server (NTRS)

    Tsiotras, Panagiotis

    1993-01-01

    Numerical simulations are often resorted to, in order to understand the attitude response and control characteristics of a rigid body. However, this approach in performing sensitivity and/or error analyses may be prohibitively expensive and time consuming, especially when a large number of problem parameters are involved. Thus, there is an important role for analytical models in obtaining an understanding of the complex dynamical behavior. In this dissertation, new analytic solutions are derived for the complete attitude motion of spinning rigid bodies, under minimal assumptions. Hence, we obtain the most general solutions reported in the literature so far. Specifically, large external torques and large asymmetries are included in the problem statement. Moreover, problems involving large angular excursions are treated in detail. A new tractable formulation of the kinematics is introduced which proves to be extremely helpful in the search for analytic solutions of the attitude history of such kinds of problems. The main utility of the new formulation becomes apparent however, when searching for feedback control laws for stabilization and/or reorientation of spinning spacecraft. This is an inherently nonlinear problem, where standard linear control techniques fail. We derive a class of control laws for spin axis stabilization of symmetric spacecraft using only two pairs of gas jet actuators. Practically, this could correspond to a spacecraft operating in failure mode, for example. Theoretically, it is also an important control problem which, because of its difficulty, has received little, if any, attention in the literature. The proposed control laws are especially simple and elegant. A feedback control law that achieves arbitrary reorientation of the spacecraft is also derived, using ideas from invariant manifold theory. The significance of this research is twofold. First, it provides a deeper understanding of the fundamental behavior of rigid bodies subject to body

  1. Flexitime: Some Problems and Solutions

    ERIC Educational Resources Information Center

    Owen, John D.

    1977-01-01

    Flexible work hours scheduling has been well received in this country as well as in Europe, where it was introduced in 1967. Some problems and their solutions attempted by various employers, unions, and government bodies are described. (MF)

  2. Body Awareness: Construct and Self-Report Measures

    PubMed Central

    Mehling, Wolf E.; Gopisetty, Viranjini; Daubenmier, Jennifer; Price, Cynthia J.; Hecht, Frederick M.; Stewart, Anita

    2009-01-01

    Objectives Heightened body awareness can be adaptive and maladaptive. Improving body awareness has been suggested as an approach for treating patients with conditions such as chronic pain, obesity and post-traumatic stress disorder. We assessed the psychometric quality of selected self-report measures and examined their items for underlying definitions of the construct. Data sources PubMed, PsychINFO, HaPI, Embase, Digital Dissertations Database. Review methods Abstracts were screened; potentially relevant instruments were obtained and systematically reviewed. Instruments were excluded if they exclusively measured anxiety, covered emotions without related physical sensations, used observer ratings only, or were unobtainable. We restricted our study to the proprioceptive and interoceptive channels of body awareness. The psychometric properties of each scale were rated using a structured evaluation according to the method of McDowell. Following a working definition of the multi-dimensional construct, an inter-disciplinary team systematically examined the items of existing body awareness instruments, identified the dimensions queried and used an iterative qualitative process to refine the dimensions of the construct. Results From 1,825 abstracts, 39 instruments were screened. 12 were included for psychometric evaluation. Only two were rated as high standard for reliability, four for validity. Four domains of body awareness with 11 sub-domains emerged. Neither a single nor a compilation of several instruments covered all dimensions. Key domains that might potentially differentiate adaptive and maladaptive aspects of body awareness were missing in the reviewed instruments. Conclusion Existing self-report instruments do not address important domains of the construct of body awareness, are unable to discern between adaptive and maladaptive aspects of body awareness, or exhibit other psychometric limitations. Restricting the construct to its proprio- and interoceptive

  3. Segmentation of human upper body movement using multiple IMU sensors.

    PubMed

    Aoki, Takashi; Lin, Jonathan Feng-Shun; Kulic, Dana; Venture, Gentiane

    2016-08-01

    This paper proposes an approach for the segmentation of human body movements measured by inertial measurement unit sensors. Using the angular velocity and linear acceleration measurements directly, without converting to joint angles, we perform segmentation by formulating the problem as a classification problem, and training a classifier to differentiate between motion end-point and within-motion points. The proposed approach is validated with experiments measuring the upper body movement during reaching tasks, demonstrating classification accuracy of over 85.8%.

  4. Age differences in everyday problem-solving effectiveness: older adults select more effective strategies for interpersonal problems.

    PubMed

    Blanchard-Fields, Fredda; Mienaltowski, Andrew; Seay, Renee Baldi

    2007-01-01

    Using the Everyday Problem Solving Inventory of Cornelius and Caspi, we examined differences in problem-solving strategy endorsement and effectiveness in two domains of everyday functioning (instrumental or interpersonal, and a mixture of the two domains) and for four strategies (avoidance-denial, passive dependence, planful problem solving, and cognitive analysis). Consistent with past research, our research showed that older adults were more problem focused than young adults in their approach to solving instrumental problems, whereas older adults selected more avoidant-denial strategies than young adults when solving interpersonal problems. Overall, older adults were also more effective than young adults when solving everyday problems, in particular for interpersonal problems.

  5. Ballet Body Belief: Perceptions of an Ideal Ballet Body from Young Ballet Dancers

    ERIC Educational Resources Information Center

    Pickard, Angela

    2013-01-01

    This paper explores what is perceived and believed to be an ideal ballet body by young ballet dancers. Such bodily belief becomes, in Pierre Bourdieu's terms, a core part of a ballet dancer's habitus. A four year longitudinal, ethnographic, empirical study of the experiences of 12 young ballet dancers, six boys and six girls, aged between 10 and…

  6. Enhancing chemistry problem-solving achievement using problem categorization

    NASA Astrophysics Data System (ADS)

    Bunce, Diane M.; Gabel, Dorothy L.; Samuel, John V.

    The enhancement of chemistry students' skill in problem solving through problem categorization is the focus of this study. Twenty-four students in a freshman chemistry course for health professionals are taught how to solve problems using the explicit method of problem solving (EMPS) (Bunce & Heikkinen, 1986). The EMPS is an organized approach to problem analysis which includes encoding the information given in a problem (Given, Asked For), relating this to what is already in long-term memory (Recall), and planning a solution (Overall Plan) before a mathematical solution is attempted. In addition to the EMPS training, treatment students receive three 40-minute sessions following achievement tests in which they are taught how to categorize problems. Control students use this time to review the EMPS solutions of test questions. Although problem categorization is involved in one section of the EMPS (Recall), treatment students who received specific training in problem categorization demonstrate significantly higher achievement on combination problems (those problems requiring the use of more than one chemical topic for their solution) at (p = 0.01) than their counterparts. Significantly higher achievement for treatment students is also measured on an unannounced test (p = 0.02). Analysis of interview transcripts of both treatment and control students illustrates a Rolodex approach to problem solving employed by all students in this study. The Rolodex approach involves organizing equations used to solve problems on mental index cards and flipping through them, matching units given when a new problem is to be solved. A second phenomenon observed during student interviews is the absence of a link in the conceptual understanding of the chemical concepts involved in a problem and the problem-solving skills employed to correctly solve problems. This study shows that explicit training in categorization skills and the EMPS can lead to higher achievement in complex problem

  7. Classical Electrodynamics: Problems with solutions; Problems with solutions

    NASA Astrophysics Data System (ADS)

    Likharev, Konstantin K.

    2018-06-01

    l Advanced Physics is a series comprising four parts: Classical Mechanics, Classical Electrodynamics, Quantum Mechanics and Statistical Mechanics. Each part consists of two volumes, Lecture notes and Problems with solutions, further supplemented by an additional collection of test problems and solutions available to qualifying university instructors. This volume, Classical Electrodynamics: Lecture notes is intended to be the basis for a two-semester graduate-level course on electricity and magnetism, including not only the interaction and dynamics charged point particles, but also properties of dielectric, conducting, and magnetic media. The course also covers special relativity, including its kinematics and particle-dynamics aspects, and electromagnetic radiation by relativistic particles.

  8. A usability evaluation of four commercial dental computer-based patient record systems

    PubMed Central

    Thyvalikakath, Thankam P.; Monaco, Valerie; Thambuganipalle, Hima Bindu; Schleyer, Titus

    2008-01-01

    Background The usability of dental computer-based patient record (CPR) systems has not been studied, despite early evidence that poor usability is a problem for dental CPR system users at multiple levels. Methods The authors conducted formal usability tests of four dental CPR systems by using a purposive sample of four groups of five novice users. The authors measured task outcomes (correctly completed, incorrectly completed and incomplete) in each CPR system while the participants performed nine clinical documentation tasks, as well as the number of usability problems identified in each CPR system and their potential relationship to task outcomes. The authors reviewed the software application design aspects responsible for these usability problems. Results The range for correctly completed tasks was 16 to 64 percent, for incorrectly completed tasks 18 to 38 percent and for incomplete tasks 9 to 47 percent. The authors identified 286 usability problems. The main types were three unsuccessful attempts, negative affect and task incorrectly completed. They also identified six problematic interface and interaction designs that led to usability problems. Conclusion The four dental CPR systems studied have significant usability problems for novice users, resulting in a steep learning curve and potentially reduced system adoption. Clinical Implications The significant number of data entry errors raises concerns about the quality of documentation in clinical practice. PMID:19047669

  9. Effect of BMI and body weight on pregnancy rates with LNG as emergency contraception: analysis of four WHO HRP studies.

    PubMed

    Festin, Mario Philip R; Peregoudov, Alexandre; Seuc, Armando; Kiarie, James; Temmerman, Marleen

    2017-01-01

    To estimate the effect of increased body weight and body mass index (BMI) on pregnancy rates with levonorgestrel (LNG) 1.5mg used as emergency contraception (EC). The study reviewed data from 6873 women in four WHO-HRP randomized trials on EC conducted between 1993 and 2010. Participants took either 1.5mg of LNG as a single dose or in two doses 12h apart, up to 120h of unprotected intercourse. Contraceptive efficacy (pregnancy rates) at different weight and BMI categories was evaluated. Overall pregnancy rate was low at 1.2%. Pregnancy rates were also low in women weighing over 80kg (0.7%) and who were obese (BMI over 30kg/m 2 ) (2.0%). The pooled analyses for pregnancy demonstrated that BMI over 30kg/m 2 decreased efficacy significantly (odds ratio 8.27, 95% confidence interval = 2.70-25.37) when compared to women in lower BMI categories, mainly influenced by pregnancies in obese women from one study site. Sensitivity analyses excluding that site showed that obesity was no longer a risk factor; however, the other studies included too few obese women in the sample to exclude a substantial decrease in efficacy. Pregnancy rates with use of LNG 1.5mg for EC were low at less than 3% across different weight and BMI categories. Pooled analyses showed an increase in pregnancy rates among obese women (BMI more than 30kg/m 2 ) compared to women with normal BMI levels, influenced by pregnancies all coming from one study site. Access to LNG as EC should still be promoted to women who need them, and not be restricted in any weight or BMI category, with additional attention for counselling and advice for obese women. Copyright © 2016. Published by Elsevier Inc.

  10. Foreign body aspiration in dentistry: a review.

    PubMed

    Cameron, S M; Whitlock, W L; Tabor, M S

    1996-08-01

    This article reviews the dangers of aspirating foreign bodies of dental origin. Two illustrative cases are presented, including an unusual case involving aspiration of an elastomeric impression material. The authors describe the techniques used to identify the foreign body. A radiodensimetric study of four impression materials demonstrates the difficulty of identifying most impression materials. The authors also present some strategies for reducing the risk of aspiration during dental procedures.

  11. Hierarchical parsing and semantic navigation of full body CT data

    NASA Astrophysics Data System (ADS)

    Seifert, Sascha; Barbu, Adrian; Zhou, S. Kevin; Liu, David; Feulner, Johannes; Huber, Martin; Suehling, Michael; Cavallaro, Alexander; Comaniciu, Dorin

    2009-02-01

    Whole body CT scanning is a common diagnosis technique for discovering early signs of metastasis or for differential diagnosis. Automatic parsing and segmentation of multiple organs and semantic navigation inside the body can help the clinician in efficiently obtaining accurate diagnosis. However, dealing with the large amount of data of a full body scan is challenging and techniques are needed for the fast detection and segmentation of organs, e.g., heart, liver, kidneys, bladder, prostate, and spleen, and body landmarks, e.g., bronchial bifurcation, coccyx tip, sternum, lung tips. Solving the problem becomes even more challenging if partial body scans are used, where not all organs are present. We propose a new approach to this problem, in which a network of 1D and 3D landmarks is trained to quickly parse the 3D CT data and estimate which organs and landmarks are present as well as their most probable locations and boundaries. Using this approach, the segmentation of seven organs and detection of 19 body landmarks can be obtained in about 20 seconds with state-of-the-art accuracy and has been validated on 80 CT full or partial body scans.

  12. Child maltreatment, parent alcohol and drug-related problems, polydrug problems, and parenting practices: a test of gender differences and four theoretical perspectives.

    PubMed

    Locke, Thomas F; Newcomb, Michael

    2004-03-01

    The authors tested how adverse childhood experiences (child maltreatment and parent alcohol- and drug-related problems) and adult polydrug use (as a mediator) predict poor parenting in a community sample (237 mothers and 81 fathers). These relationships were framed within several theoretical perspectives, including observational learning, impaired functioning, self-medication, and parentification-pseudomaturity. Structural models revealed that child maltreatment predicted poor parenting practices among mothers. Parent alcohol- and drug-related problems had an indirect detrimental influence on mothers' parenting and practices through self-drug problems. Among fathers, emotional neglect experienced as a child predicted lack of parental warmth more parental neglect, and sexual abuse experienced as a child predicted a rejecting style of parenting.

  13. Mind/Body Connection: How Your Emotions Affect Your Health

    MedlinePlus

    ... your doctor How can I better cope with stress? Are my health problems causing my stress or is my stress causing my health problems? I don’t think I’m under stress, but is my body telling me that I ...

  14. Two-body and three-body wear of glass ionomer cements.

    PubMed

    Kunzelmann, K H; Bürkle, V; Bauer, C

    2003-11-01

    Glass ionomer cements (GIC) have been modified in an attempt to improve their mechanical properties. The objective of the present paper was to compare the two-body and three-body wear of four modified GIC. The tested materials were Fuji IX (GC Corporation), Hi-Fi (Shofu) and Ketac Molar Aplicap (3M/ESPE). The cermet cement Ketac Silver Maxicap (3M/ESPE) was used as reference material. Two-body wear tests were carried out in the computer controlled 'artificial mouth' of the Munich Dental School, three-body wear was tested with the ACTA wear machine. The resulting average two-body wear rates (in microm) were: Fuji IX 327 (SD +/- 82) < Ketac Molar 379 (SD +/- 94) < Hi-Fi 376 (SD +/- 90) < Ketac silver 449 (SD +/- 127). The differences between the materials were significant (P < 0.05, ANOVA, modified LSD-test) with the exception of Ketac Molar and Hi-Fi. The average three-body wear rates (in microm) were: Hi-Fi 30 (SD +/- 10) < Ketac Molar +/- 42 (SD +/- 12) < Fuji IX 49 (SD +/- 14) < Ketac silver 73 (SD +/- 23). The difference between Ketac silver and the three other materials was significant (P < 0.05, ANOVA, modified LSD-test). No significant difference was calculated between Hi-Fi, Ketac Molar and Fuji IX. As Ketac Molar, Hi-Fi and Fuji IX show better wear resistance compared to Ketac silver both in occlusal-contact and contact-free areas, it may be assumed that the wear resistance of a glass ionomer cement may be improved more by changing the powder: liquid ratio than by incorporating silver particles into the glass powder.

  15. Stochastic evaluation of second-order many-body perturbation energies.

    PubMed

    Willow, Soohaeng Yoo; Kim, Kwang S; Hirata, So

    2012-11-28

    With the aid of the Laplace transform, the canonical expression of the second-order many-body perturbation correction to an electronic energy is converted into the sum of two 13-dimensional integrals, the 12-dimensional parts of which are evaluated by Monte Carlo integration. Weight functions are identified that are analytically normalizable, are finite and non-negative everywhere, and share the same singularities as the integrands. They thus generate appropriate distributions of four-electron walkers via the Metropolis algorithm, yielding correlation energies of small molecules within a few mE(h) of the correct values after 10(8) Monte Carlo steps. This algorithm does away with the integral transformation as the hotspot of the usual algorithms, has a far superior size dependence of cost, does not suffer from the sign problem of some quantum Monte Carlo methods, and potentially easily parallelizable and extensible to other more complex electron-correlation theories.

  16. Enhancing creativity: Proper body posture meets proper emotion.

    PubMed

    Hao, Ning; Xue, Hua; Yuan, Huan; Wang, Qing; Runco, Mark A

    2017-02-01

    This study tested whether compatibility or incompatibility between body posture and emotion was beneficial for creativity. In Study 1, participants were asked to solve the Alternative Uses Task (AUT) problems when performing open or closed body posture in positive or negative emotional state respectively. The results showed that originality of AUT performance was higher in the compatible conditions (i.e., open-positive and closed-negative) than in the incompatible conditions (i.e., closed-positive and open-negative). In Study 2, the compatibility effect was replicated in both the AUT and the Realistic Presented Problem test (i.e., RPP). Moreover, it was revealed that participants exhibited the highest associative flexibility in the open-positive condition, and the highest persistence in the closed-negative condition. These findings indicate that compatibility between body posture and emotion is beneficial for creativity. This may be because when the implicit emotions elicited by body posture match explicit emotions, the effects of emotions on creativity are enhanced, therefore promoting creativity through the flexibility or the persistence pathway respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. A Body of Work Standard-Setting Method with Construct Maps

    ERIC Educational Resources Information Center

    Wyse, Adam E.; Bunch, Michael B.; Deville, Craig; Viger, Steven G.

    2014-01-01

    This article describes a novel variation of the Body of Work method that uses construct maps to overcome problems of transparency, rater inconsistency, and scores gaps commonly occurring with the Body of Work method. The Body of Work method with construct maps was implemented to set cut-scores for two separate K-12 assessment programs in a large…

  18. The theory and technique of yamuna body rolling.

    PubMed

    Suzuki, Satoshi

    2013-09-01

    [Purpose] This paper provides information about the theory and technique of Yamuna Body Rolling. In order to treat physical problems, using the specialized Yamuna Body Rolling balls, people can target superficial skin, fasciae, muscle fibers, tendons, ligaments, bones, internal organs, and the nervous system by themselves. The extraordinary effect of Yamuna Body Rolling is its multidimensional elongation of muscle fibers. In addition to the regular longitudinal elongation by the conventional stretch method, Yamuna Body Rolling enables the transversal and diagonal expansion of muscle fibers in order to move the body more dynamically. Hamstring, abdominal, and sideline routines are presented as examples for techniques of Yamuna Body Rolling. Yamuna Body Rolling can be applied to functional evaluation and therapeutic uses; therefore, it could provide many benefits in the treatment of different conditions in the medical field.

  19. Vaginal foreign bodies.

    PubMed

    Stricker, T; Navratil, F; Sennhauser, F H

    2004-04-01

    To evaluate the clinical features and outcome in girls with a vaginal foreign body. Retrospective review of medical records of 35 girls with a vaginal foreign body seen in an outpatient clinic for paediatric and adolescent gynaecology between 1980 and 2000. The ages ranged from 2.6 to 9.2 years. The most common symptom was blood-stained vaginal discharge/vaginal bleeding (49%). Duration of symptoms varied from 1 day to 2 years. Fifty-four percent of the patients recalled insertion of the foreign object, usually by the girl herself. All but three patients (91%) either recalled insertion of the foreign object and/or had vaginal bleeding or blood-stained or foul-smelling vaginal discharge, and/or visualization or palpation of the foreign body in physical examination. Symptoms resolved after removal of the foreign body followed by a single irrigation with Providon-Iod (Betadine). In the majority of patients a carefully obtained history and physical examination suggest the diagnosis of a vaginal foreign object. The leading symptoms are vaginal bleeding and blood-stained or foul smelling vaginal discharge. Removal of the foreign object followed by a single irrigation with Providon-Iod is the definitive treatment and does not require additional measures.

  20. How culture shapes the body: cultural consonance and body mass in urban Brazil.

    PubMed

    Dressler, William W; Oths, Kathryn S; Balieiro, Mauro C; Ribeiro, Rosane P; Dos Santos, José Ernesto

    2012-01-01

    The aim of this article is to develop a model of how culture shapes the body, based on two studies conducted in urban Brazil. Research was conducted in 1991 and 2001 in four socioeconomically distinct neighborhoods. First, cultural domain analyses were conducted with samples of key informants. The cultural domains investigated included lifestyle, social support, family life, national identity, and food. Cultural consensus analysis was used to confirm shared knowledge in each domain and to derive measures of cultural consonance. Cultural consonance assesses how closely an individual matches the cultural consensus model for each domain. Second, body composition, cultural consonance, and related variables were assessed in community surveys. Multiple regression analysis was used to examine the association of cultural consonance and body composition, controlling for standard covariates and competing explanatory variables. In 1991, in a survey of 260 individuals, cultural consonance had a curvilinear association with the body mass index that differed for men and women, controlling for sociodemographic and dietary variables. In 2001, in a survey of 267 individuals, cultural consonance had a linear association with abdominal circumference that differed for men and women, controlling for sociodemographic and dietary variables. In general, as cultural consonance increases, body mass index and abdominal circumference decline, more strongly for women than men. As individuals, in their own beliefs and behaviors, more closely approximate shared cultural models in socially salient domains, body composition also more closely approximates the cultural prototype of the body. Copyright © 2012 Wiley Periodicals, Inc.

  1. Experience of excess skin and desire for body contouring surgery in post-bariatric patients.

    PubMed

    Staalesen, T; Fagevik Olsén, M; Elander, A

    2013-10-01

    This study was done to analyze the problems of post-bariatric patients with excess skin and to determine their interest in body contouring surgery. The self-administered Sahlgrenska Excess Skin Questionnaire (SESQ) was used together with a study-specific questionnaire. The patients who were operated with bariatric surgery at Sahlgrenska University Hospital between 1999 and 2008 were identified and sent the SESQ and a study-specific questionnaire. The response rate was 65% (23% men). The most common problem in both men and women was the feeling of having an unattractive body (91 and 67%, respectively). The most frequently reported sites of excess skin were the upper arms in women (91%) and the abdomen in men (78%). In both women and men, excess skin on the abdomen was reported to cause the most discomfort (median 7 and 3, respectively, on a scale from 0 to 10). Women reported significantly more problems, discomfort, and amount of excess skin (p < 0.05) than men. There was a strong correlation between the amount of excess skin and the degree of discomfort for all body parts. Seventeen percent of the responders had been operated with body contouring surgery of one body part and 5% of two or more. Fourteen percent desired body contouring surgery of one body part and 61% of two or more. Most post-bariatric patients, but women in particular, experience significant problems of excess skin and request body contouring surgery.

  2. Electric Shock and the Human Body.

    ERIC Educational Resources Information Center

    Brown, Colin

    1986-01-01

    Discusses electricity's documented effects on the human body, including both the dangers to human health and the medical application of electrical stimulation to heart problems. Discusses the teaching of such physics topics to potential medical students. (TW)

  3. [Smuggling of illegal drugs by body suffers].

    PubMed

    Aksnes, Tonje Amb; Jacobsen, Dag

    2004-07-01

    Body packers are persons who smuggle illegal drugs by swallowing condoms or plastic cylinders containing such substances. Body stuffers are drug dealers or drug abusers who swallow illegal drugs in an effort to conceal evidence during an arrest or in fear of being arrested. We report four cases and discuss management. Asymptomatic body packers may be managed conservatively with laxatives and water-soluble contrast medium. This method allows an accurate follow-up with abdominal radiography. If patients develop abdominal pain or signs and symptoms of intoxication, surgical intervention should be considered. Both types of patients should be monitored carefully.

  4. Students' Problem Solving and Justification

    ERIC Educational Resources Information Center

    Glass, Barbara; Maher, Carolyn A.

    2004-01-01

    This paper reports on methods of students' justifications of their solution to a problem in the area of combinatorics. From the analysis of the problem solving of 150 students in a variety of settings from high-school to graduate study, four major forms of reasoning evolved: (1) Justification by Cases, (2) Inductive Argument, (3) Elimination…

  5. MRI Evaluation of Spinal Length and Vertebral Body Angle During Loading with a Spinal Compression Harness

    NASA Technical Reports Server (NTRS)

    Campbell, James A.; Hargens, Alan R.; Murthy, G.; Ballard, R. E.; Watenpaugh, D. E.; Hargens, Alan, R.; Sanchez, E.; Yang, C.; Mitsui, I.; Schwandt, D.; hide

    1998-01-01

    Weight bearing by the spinal column during upright posture often plays a role in the common problem of low back pain. Therefore, we developed a non-ferromagnetic spinal compression harness to enable MRI investigations of the spinal column during axial loading. Human subjects were fitted with a Nest and a footplate which were connected by adjustable straps to an analog load cell. MRI scans of human subjects (5 males and 1 female with age range of 27-53 yrs) during loaded and unloaded conditions were accomplished with a 1.5 Tesla GE Signa scanner. Studies of two subjects undergoing sequentially increasing spinal loads revealed significant decreases (r(sup 2) = 0.852) in spinal length between T4 and L5 culminating in a 1.5 to 2% length decrease during loading with 75% body weight. Sagittal vertebral body angles of four subjects placed under a constant 50% body weight load for one hour demonstrated increased lordotic and kyphotic curvatures. In the lumbar spine, the L2 vertebral body experienced the greatest angular change (-3 deg. to -5 deg.) in most subjects while in the thoracic spine, T4 angles increased from the unloaded state by +2 deg. to +9 deg. Overall, our studies demonstrate: 1) a progressive, although surprisingly small, decrease in spinal length with increasing load and 2) relatively large changes in spinal column angulation with 50% body weight.

  6. Cost-Effectiveness of Four Parenting Programs and Bibliotherapy for Parents of Children with Conduct Problems.

    PubMed

    Sampaio, Filipa; Enebrink, Pia; Mihalopoulos, Cathrine; Feldman, Inna

    2016-12-01

    Parenting programs and self-help parenting interventions employing written materials are effective in reducing child conduct problems (CP) in the short-term compared to control groups, however evidence on the cost-effectiveness of such interventions is insufficient. Few studies have looked at the differences in effects between interventions in the same study design. This study aimed to determine the cost-effectiveness of four parenting programs: Comet, Incredible Years (IY), Cope and Connect, and bibliotherapy, compared to a waitlist control (WC), with a time horizon of 4 months, targeting CP in children aged 3-12 years. This economic evaluation was conducted alongside an RCT of the four parenting interventions and bibliotherapy compared to a WC. The study sample consisted of 961 parents of 3-12 year-old children with CP. CP was measured by the Eyberg Child Behavior Inventory. Effectiveness was expressed as the proportion of "recovered" cases of CP. The time horizon of the study was four months with a limited health sector perspective, including parents' time costs. We performed an initial comparative cost analysis for interventions whose outcomes differed significantly from the WC, and later a cost-effectiveness analysis of interventions whose outcomes differed significantly from both the WC and each other. Secondary analyses were performed: (i) joint outcome "recovered and improved", (ii) intervention completers, (iii) exclusion of parents' time costs, (iv) exclusion of training costs. All interventions apart from Connect significantly reduced CP compared to the WC. Of the other interventions Comet resulted in a significantly higher proportion of recovered cases compared to bibliotherapy. A comparative cost analysis of the effective interventions rendered an average cost per recovered case for bibliotherapy of USD 483, Cope USD 1972, Comet USD 3741, and IY USD 6668. Furthermore, Comet had an ICER of USD 8375 compared to bibliotherapy. Secondary analyses of

  7. Patterns of infestation by the trombiculid mite Eutrombicula alfreddugesi in four sympatric lizard species (genus Tropidurus) in northeastern Brazil.

    PubMed

    Rocha, C F D; Cunha-Barros, M; Menezes, V A; Fontes, A f; Vrcibradic, D; Van Sluys, M

    2008-06-01

    We studied the parasitism by the chigger mite Eutrombicula alfreddugesi on four sympatric lizard species of the genus Tropidurus in Morro do Chapéu, Bahia state, Brazil: T. hispidus, T. cocorobensis, T. semitaeniatus and T. erythrocephalus. For each species, we investigated the patterns of infestation and analyzed to which extent they varied among the hosts. We calculated the spatial niche breadth of the chigger mite on the body of each host species and the distribution of mites along the hosts' bodies for each Tropidurus species. All four species of Tropidurus at Morro do Chapéu were parasited by the chigger mite, with high (97-100%) prevalences. Host body size significantly explained the intensity of mite infestation for all species, except T. erythrocephalus. The body regions with highest intensity of infestation in the four lizard species were the mite pockets. The spacial niche width of the chigger varied consistently among the four lizards species studied being highest for T. erytrocephalus and lowest for T. cocorobensis. We conclude that the distribution and intensity with which lizards of the genus Tropidurus are infested by Eutrombicula alfreddugesi larvae results from the interaction between aspects of host morphology (such as body size and the occurrence and distribution of mite pockets) and ecology (especially microhabitat use).

  8. Mind over matter? I: philosophical aspects of the mind-brain problem.

    PubMed

    Schimmel, P

    2001-08-01

    To conceptualize the essence of the mind-body or mind-brain problem as one of metaphysics rather than science, and to propose a formulation of the problem in the context of current scientific knowledge and its limitations. The background and conceptual parameters of the mind-body problem are delineated, and the limitations of brain research in formulating a solution identified. The problem is reformulated and stated in terms of two propositions. These constitute a 'double aspect theory'. The problem appears to arise as a consequence of the conceptual limitations of the human mind, and hence remains essentially a metaphysical one. A 'double aspect theory' recognizes the essential unity of mind and brain, while remaining consistent with the dualism inherent in human experience.

  9. Independent Aftereffects of Fat and Muscle: Implications for neural encoding, body space representation, and body image disturbance

    PubMed Central

    Sturman, Daniel; Stephen, Ian D.; Mond, Jonathan; Stevenson, Richard J; Brooks, Kevin R.

    2017-01-01

    Although research addressing body size misperception has focused on socio-cognitive processes, such as internalization of the “ideal” images of bodies in the media, the perceptual basis of this phenomenon remains largely unknown. Further, most studies focus on body size per se even though this depends on both fat and muscle mass – variables that have very different relationships with health. We tested visual adaptation as a mechanism for inducing body fat and muscle mass misperception, and assessed whether these two dimensions of body space are processed independently. Observers manipulated the apparent fat and muscle mass of bodies to make them appear “normal” before and after inspecting images from one of four adaptation conditions (increased fat/decreased fat/increased muscle/decreased muscle). Exposure resulted in a shift in the point of subjective normality in the direction of the adapting images along the relevant (fat or muscle) axis, suggesting that the neural mechanisms involved in body fat and muscle perception are independent. This supports the viability of adaptation as a model of real-world body size misperception, and extends its applicability to clinical manifestations of body image disturbance that entail not only preoccupation with thinness (e.g., anorexia nervosa) but also with muscularity (e.g., muscle dysmorphia). PMID:28071712

  10. Independent Aftereffects of Fat and Muscle: Implications for neural encoding, body space representation, and body image disturbance.

    PubMed

    Sturman, Daniel; Stephen, Ian D; Mond, Jonathan; Stevenson, Richard J; Brooks, Kevin R

    2017-01-10

    Although research addressing body size misperception has focused on socio-cognitive processes, such as internalization of the "ideal" images of bodies in the media, the perceptual basis of this phenomenon remains largely unknown. Further, most studies focus on body size per se even though this depends on both fat and muscle mass - variables that have very different relationships with health. We tested visual adaptation as a mechanism for inducing body fat and muscle mass misperception, and assessed whether these two dimensions of body space are processed independently. Observers manipulated the apparent fat and muscle mass of bodies to make them appear "normal" before and after inspecting images from one of four adaptation conditions (increased fat/decreased fat/increased muscle/decreased muscle). Exposure resulted in a shift in the point of subjective normality in the direction of the adapting images along the relevant (fat or muscle) axis, suggesting that the neural mechanisms involved in body fat and muscle perception are independent. This supports the viability of adaptation as a model of real-world body size misperception, and extends its applicability to clinical manifestations of body image disturbance that entail not only preoccupation with thinness (e.g., anorexia nervosa) but also with muscularity (e.g., muscle dysmorphia).

  11. SPH for impact force and ricochet behavior of water-entry bodies

    NASA Astrophysics Data System (ADS)

    Omidvar, Pourya; Farghadani, Omid; Nikeghbali, Pooyan

    The numerical modeling of fluid interaction with a bouncing body has many applications in scientific and engineering application. In this paper, the problem of water impact of a body on free-surface is investigated, where the fixed ghost boundary condition is added to the open source code SPHysics2D1 to rectify the oscillations in pressure distributions with the repulsive boundary condition. First, after introducing the methodology of SPH and the option of boundary conditions, the still water problem is simulated using two types of boundary conditions. It is shown that the fixed ghost boundary condition gives a better result for a hydrostatics pressure. Then, the dam-break problem, which is a bench mark test case in SPH, is simulated and compared with available data. In order to show the behavior of the hydrostatics forces on bodies, a fix/floating cylinder is placed on free surface looking carefully at the force and heaving profile. Finally, the impact of a body on free-surface is successfully simulated for different impact angles and velocities.

  12. Prediction of vortex shedding from circular and noncircular bodies in subsonic flow

    NASA Technical Reports Server (NTRS)

    Mendenhall, Michael R.; Lesieutre, Daniel J.

    1987-01-01

    An engineering prediction method and associated computer code VTXCLD are presented which predict nose vortex shedding from circular and noncircular bodies in subsonic flow at angles of attack and roll. The axisymmetric body is represented by point sources and doublets, and noncircular cross sections are transformed to a circle by either analytical or numerical conformal transformations. The leeward vortices are modeled by discrete vortices in crossflow planes along the body; thus, the three-dimensional steady flow problem is reduced to a two-dimensional, unsteady, separated flow problem for solution. Comparison of measured and predicted surface pressure distributions, flowfield surveys, and aerodynamic characteristics are presented for bodies with circular and noncircular cross sectional shapes.

  13. Electromagnetic Radiation Efficiency of Body-Implanted Devices

    NASA Astrophysics Data System (ADS)

    Nikolayev, Denys; Zhadobov, Maxim; Karban, Pavel; Sauleau, Ronan

    2018-02-01

    Autonomous wireless body-implanted devices for biotelemetry, telemedicine, and neural interfacing constitute an emerging technology providing powerful capabilities for medicine and clinical research. We study the through-tissue electromagnetic propagation mechanisms, derive the optimal frequency range, and obtain the maximum achievable efficiency for radiative energy transfer from inside a body to free space. We analyze how polarization affects the efficiency by exciting TM and TE modes using a magnetic dipole and a magnetic current source, respectively. Four problem formulations are considered with increasing complexity and realism of anatomy. The results indicate that the optimal operating frequency f for deep implantation (with a depth d ≳3 cm ) lies in the (108- 109 )-Hz range and can be approximated as f =2.2 ×107/d . For a subcutaneous case (d ≲3 cm ), the surface-wave-induced interference is significant: within the range of peak radiation efficiency (about 2 ×108 to 3 ×109 Hz ), the max-to-min ratio can reach a value of 6.5. For the studied frequency range, 80%-99% of radiation efficiency is lost due to the tissue-air wave-impedance mismatch. Parallel polarization reduces the losses by a few percent; this effect is inversely proportional to the frequency and depth. Considering the implantation depth, the operating frequency, the polarization, and the directivity, we show that about an order-of-magnitude efficiency improvement is achievable compared to existing devices.

  14. Lifestyle Factors and Premature Ejaculation: Are Physical Exercise, Alcohol Consumption, and Body Mass Index Associated With Premature Ejaculation and Comorbid Erectile Problems?

    PubMed

    Ventus, Daniel; Jern, Patrick

    2016-10-01

    Premature ejaculation (PE) is a common sexual problem in men, but its etiology remains uncertain. Lifestyle factors have long been hypothesized to be associated with sexual problems in general and have been proposed as risk factors for PE. To explore associations among physical exercise, alcohol use, body mass index, PE, and erectile dysfunction. A population-based sample of Finnish men and a sample of Finnish men diagnosed with PE were surveyed for statistical comparisons. Participants using selective serotonin reuptake inhibitors or other medications known to affect symptoms of PE were excluded from analyses. Self-report questionnaires: Multiple Indicators of Premature Ejaculation, International Index of Erectile Function-5, Alcohol Use Disorders Identification Test, and Godin Leisure-Time Exercise Questionnaire. The clinical sample reported lower levels of physical exercise (mean = 27.53, SD = 21.01, n = 69) than the population-based sample (mean = 34.68, SD = 22.82, n = 863, t930 = 2.52, P = .012), and the effect size was large (d = 0.85). There was a small negative correlation between levels of physical exercise and symptoms of PE (r = -0.09, P < .01, n = 863) in the population-based sample. The association between physical exercise and PE remained significant after controlling for effects of age, erectile dysfunction, alcohol use, and body mass index. If future studies show that the direction of causality of this association is such that physical activity alleviates PE symptoms, then including physical activity in PE treatment interventions could be a promising addition to treatment regimes. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

  15. Teaching Effective Problem Solving Strategies for Interns

    ERIC Educational Resources Information Center

    Warren, Louis L.

    2005-01-01

    This qualitative study investigates what problem solving strategies interns learn from their clinical teachers during their internships. Twenty-four interns who completed their internship in the elementary grades shared what problem solving strategies had the greatest impact upon them in learning how to deal with problems during their internship.…

  16. Arithmetic Word-Problem-Solving in Huntington's Disease

    ERIC Educational Resources Information Center

    Allain, P.; Verny, C.; Aubin, G.; Pinon, K.; Bonneau, D.; Dubas, F.; Gall, D.L.

    2005-01-01

    The purpose of this study was to examine executive functioning in patients with Huntington's disease using an arithmetic word-problem-solving task including eight solvable problems of increasing complexity and four aberrant problems. Ten patients with Huntington's disease and 12 normal control subjects matched by age and education were tested.…

  17. Estimating body weight and body composition of chickens by using noninvasive measurements.

    PubMed

    Latshaw, J D; Bishop, B L

    2001-07-01

    The major objective of this research was to develop equations to estimate BW and body composition using measurements taken with inexpensive instruments. We used five groups of chickens that were created with different genetic stocks and feeding programs. Four of the five groups were from broiler genetic stock, and one was from sex-linked heavy layers. The goal was to sample six males from each group when the group weight was 1.20, 1.75, and 2.30 kg. Each male was weighed and measured for back length, pelvis width, circumference, breast width, keel length, and abdominal skinfold thickness. A cloth tape measure, calipers, and skinfold calipers were used for measurement. Chickens were scanned for total body electrical conductivity (TOBEC) before being euthanized and frozen. Six females were selected at weights similar to those for males and were measured in the same way. Each whole chicken was ground, and a portion of ground material of each was used to measure water, fat, ash, and energy content. Multiple linear regression was used to estimate BW from body measurements. The best single measurement was pelvis width, with an R2 = 0.67. Inclusion of three body measurements in an equation resulted in R2 = 0.78 and the following equation: BW (g) = -930.0 + 68.5 (breast, cm) + 48.5 (circumference, cm) + 62.8 (pelvis, cm). The best single measurement to estimate body fat was abdominal skinfold thickness, expressed as a natural logarithm. Inclusion of weight and skinfold thickness resulted in R2 = 0.63 for body fat according to the following equation: fat (%) = 24.83 + 6.75 (skinfold, ln cm) - 3.87 (wt, kg). Inclusion of the result of TOBEC and the effect of sex improved the R2 to 0.78 for body fat. Regression analysis was used to develop additional equations, based on fat, to estimate water and energy contents of the body. The body water content (%) = 72.1 - 0.60 (body fat, %), and body energy (kcal/g) = 1.097 + 0.080 (body fat, %). The results of the present study

  18. Neural correlates of human body perception.

    PubMed

    Aleong, Rosanne; Paus, Tomás

    2010-03-01

    The objective of this study was to investigate potential sex differences in the neural response to human bodies using fMRI carried out in healthy young adults. We presented human bodies in a block-design experiment to identify body-responsive regions of the brain, namely, extrastriate body area (EBA) and fusiform body area (FBA). In a separate event-related "adaptation" experiment, carried out in the same group of subjects, we presented sets of four human bodies of varying body size and shape. Varying levels of body morphing were introduced to assess the degree of morphing required for adaptation release. Analysis of BOLD signal in the block-design experiment revealed significant Sex x Hemisphere interactions in the EBA and the FBA responses to human bodies. Only women showed greater BOLD response to bodies in the right hemisphere compared with the left hemisphere for both EBA and FBA. The BOLD response in right EBA was higher in women compared with men. In the adaptation experiment, greater right versus left hemisphere response for EBA and FBA was also identified among women but not men. These findings are particularly novel in that they address potential sex differences in the lateralization of EBA and FBA responses to human body images. Although previous studies have found some degree of right hemisphere dominance in body perception, our results suggest that such a functional lateralization may differ between men and women.

  19. A family of four stages embedded explicit six-step methods with eliminated phase-lag and its derivatives for the numerical solution of the second order problems

    NASA Astrophysics Data System (ADS)

    Simos, T. E.

    2017-11-01

    A family of four stages high algebraic order embedded explicit six-step methods, for the numerical solution of second order initial or boundary-value problems with periodical and/or oscillating solutions, are studied in this paper. The free parameters of the new proposed methods are calculated solving the linear system of equations which is produced by requesting the vanishing of the phase-lag of the methods and the vanishing of the phase-lag's derivatives of the schemes. For the new obtained methods we investigate: • Its local truncation error (LTE) of the methods.• The asymptotic form of the LTE obtained using as model problem the radial Schrödinger equation.• The comparison of the asymptotic forms of LTEs for several methods of the same family. This comparison leads to conclusions on the efficiency of each method of the family.• The stability and the interval of periodicity of the obtained methods of the new family of embedded finite difference pairs.• The applications of the new obtained family of embedded finite difference pairs to the numerical solution of several second order problems like the radial Schrödinger equation, astronomical problems etc. The above applications lead to conclusion on the efficiency of the methods of the new family of embedded finite difference pairs.

  20. A comparative study of four major approaches to predicting ATES performance

    NASA Astrophysics Data System (ADS)

    Doughty, C.; Buscheck, T. A.; Bodvarsson, G. S.; Tsang, C. F.

    1982-09-01

    The International Energy Agency test problem involving Aquifer Thermal Energy Storage was solved using four approaches: the numerical model PF (formerly CCC), the simpler numerical model SFM, and two graphical characterization schemes. Each of the four techniques, with the advantages and disadvantages of each, are discussed.

  1. Aerothermodynamics of blunt body entry vehicles

    NASA Astrophysics Data System (ADS)

    Hollis, Brian R.; Borrelli, Salvatore

    2012-01-01

    In this chapter, the aerothermodynamic phenomena of blunt body entry vehicles are discussed. Four topics will be considered that present challenges to current computational modeling techniques for blunt body environments: turbulent flow, non-equilibrium flow, rarefied flow, and radiation transport. Examples of comparisons between computational tools to ground and flight-test data will be presented in order to illustrate the challenges existing in the numerical modeling of each of these phenomena and to provide test cases for evaluation of computational fluid dynamics (CFD) code predictions.

  2. [Body image among obese women: consequences and degree of body dissatisfaction, relationship with low self-esteem and coping strategies].

    PubMed

    Brytek-Matera, Anna

    2010-01-01

    Definition of factors influencing negative body image among obese women and analysis of the relationship between body dissatisfaction and personality variables. 63 patients participated in this study. The mean age of the obese subjects was 41.90 years (SD +/- 12.23) and the mean body mass index (BMI) was 37.09 kg/m2 (SD +/- 8.09). The control group consisted of 60 women with normal body weight. The Body Dissatisfaction Scale of EDI (Garner et al., 1984), the Self-Esteem Inventory (Coopersmith, 1983) and the Brief COPE (Carver, 1997) were used in the study. In the clinical sample of women suffering from obesity, we have found a correlation between body dissatisfaction and behavioural disengagement, four dimensions of self-esteem (general, social, family and professional) and coping strategies focused on planning and positive reinterpretation. The regression analysis revealed that use of emotional support, planning and general self-esteem were predictive factors for the body dissatisfaction in obesity. Body dissatisfaction seriously influences the social, professional and emotional obese women's self.

  3. Free and controlled motion of a body with a moving internal mass through a fluid in the presence of circulation around the body

    NASA Astrophysics Data System (ADS)

    Vetchanin, E. V.; Kilin, A. A.

    2016-01-01

    The free and controlled motion of an arbitrary two-dimensional body with a moving internal mass and constant circulation around the body in an ideal fluid is studied. Bifurcation analysis of the free motion is performed (under the condition of a fixed internal mass). It is shown that the body can be moved to a given point by varying the position of the internal mass. Some problems related to the presence of a nonzero drift of the body with a fixed internal mass are noted.

  4. Influence of Body Composition on Gait Kinetics throughout Pregnancy and Postpartum Period

    PubMed Central

    Branco, Marco; Santos-Rocha, Rita; Vieira, Filomena; Silva, Maria-Raquel; Aguiar, Liliana; Veloso, António P.

    2016-01-01

    Pregnancy leads to several changes in body composition and morphology of women. It is not clear whether the biomechanical changes occurring in this period are due exclusively to body composition and size or to other physiological factors. The purpose was to quantify the morphology and body composition of women throughout pregnancy and in the postpartum period and identify the contribution of these parameters on the lower limb joints kinetic during gait. Eleven women were assessed longitudinally, regarding anthropometric, body composition, and kinetic parameters of gait. Body composition and body dimensions showed a significant increase during pregnancy and a decrease in the postpartum period. In the postpartum period, body composition was similar to the 1st trimester, except for triceps skinfold, total calf area, and body mass index, with higher results than at the beginning of pregnancy. Regression models were developed to predict women's internal loading through anthropometric variables. Four models include variables associated with the amount of fat; four models include variables related to overall body weight; three models include fat-free mass; one model includes the shape of the trunk as a predictor variable. Changes in maternal body composition and morphology largely determine kinetic dynamics of the joints in pregnant women. PMID:27073713

  5. Detection of Problem Gambler Subgroups Using Recursive Partitioning

    ERIC Educational Resources Information Center

    Markham, Francis; Young, Martin; Doran, Bruce

    2013-01-01

    The multivariate socio-demographic risk factors for problem gambling have been well documented. While this body of research is valuable in determining risk factors aggregated across various populations, the majority of studies tend not to specifically identify particular subgroups of problem gamblers based on the interaction between variables. The…

  6. Mathematical Problem Solving: A Review of the Literature.

    ERIC Educational Resources Information Center

    Funkhouser, Charles

    The major perspectives on problem solving of the twentieth century are reviewed--associationism, Gestalt psychology, and cognitive science. The results of the review on teaching problem solving and the uses of computers to teach problem solving are included. Four major issues related to the teaching of problem solving are discussed: (1)…

  7. Visual Attention for Solving Multiple-Choice Science Problem: An Eye-Tracking Analysis

    ERIC Educational Resources Information Center

    Tsai, Meng-Jung; Hou, Huei-Tse; Lai, Meng-Lung; Liu, Wan-Yi; Yang, Fang-Ying

    2012-01-01

    This study employed an eye-tracking technique to examine students' visual attention when solving a multiple-choice science problem. Six university students participated in a problem-solving task to predict occurrences of landslide hazards from four images representing four combinations of four factors. Participants' responses and visual attention…

  8. Vortex Design Problem

    NASA Astrophysics Data System (ADS)

    Protas, Bartosz

    2007-11-01

    In this investigation we are concerned with a family of solutions of the 2D steady--state Euler equations, known as the Prandtl--Batchelor flows, which are characterized by the presence of finite--area vortex patches embedded in an irrotational flow. We are interested in flows in the exterior of a circular cylinder and with a uniform stream at infinity, since such flows are often employed as models of bluff body wakes in the high--Reynolds number limit. The ``vortex design'' problem we consider consists in determining a distribution of the wall--normal velocity on parts of the cylinder boundary such that the vortex patches modelling the wake vortices will have a prescribed shape and location. Such inverse problem have applications in various areas of flow control, such as mitigation of the wake hazard. We show how this problem can be solved computationally by formulating it as a free--boundary optimization problem. In particular, we demonstrate that derivation of the adjoint system, required to compute the cost functional gradient, is facilitated by application of the shape differential calculus. Finally, solutions of the vortex design problem are illustrated with computational examples.

  9. Midline Body Actions and Leftward Spatial “Aiming” in Patients with Spatial Neglect

    PubMed Central

    Chaudhari, Amit; Pigott, Kara; Barrett, A. M.

    2015-01-01

    Spatial motor–intentional “Aiming” bias is a dysfunction in initiation/execution of motor–intentional behavior, resulting in hypokinetic and hypometric leftward movements. Aiming bias may contribute to posture, balance, and movement problems and uniquely account for disability in post-stroke spatial neglect. Body movement may modify and even worsen Aiming errors, but therapy techniques, such as visual scanning training, do not take this into account. Here, we evaluated (1) whether instructing neglect patients to move midline body parts improves their ability to explore left space and (2) whether this has a different impact on different patients. A 68-year-old woman with spatial neglect after a right basal ganglia infarct had difficulty orienting to and identifying left-sided objects. She was prompted with four instructions: “look to the left,” “point with your nose to the left,” “point with your [right] hand to the left,” and “stick out your tongue and point it to the left.” She oriented leftward dramatically better when pointing with the tongue/nose, than she did when pointing with the hand. We then tested nine more consecutive patients with spatial neglect using the same instructions. Only four of them made any orienting errors. Only one patient made >50% errors when pointing with the hand, and she did not benefit from pointing with the tongue/nose. We observed that pointing with the tongue could facilitate left-sided orientation in a stroke survivor with spatial neglect. If midline structures are represented more bilaterally, they may be less affected by Aiming bias. Alternatively, moving the body midline may be more permissive for leftward orienting than moving right body parts. We were not able to replicate this effect in another patient; we suspect that the magnitude of this effect may depend upon the degree to which patients have directional akinesia, spatial Where deficits, or cerebellar/frontal cortical lesions. Future research

  10. Strategies for Meeting Correctional Training and Manpower Needs, Four Developmental Projects.

    ERIC Educational Resources Information Center

    Law Enforcement Assistance Administration (Dept. of Justice), Washington, DC.

    The Law Enforcement Education Act of 1965 has placed special emphasis on projects involving training and utilization of correctional manpower. The four representative projects reported here give a comprehensive view of the problems of upgrading correctional staff and possible solutions to those problems: (1) "The Developmental Laboratory for…

  11. Evaluation of Body Weight, Body Condition, and Muscle Condition in Cats with Hyperthyroidism.

    PubMed

    Peterson, M E; Castellano, C A; Rishniw, M

    2016-11-01

    The contribution of fat loss versus muscle wasting to the loss of body weight seen in hyperthyroid cats is unknown. To investigate body weight, body condition score (BCS), and muscle condition score (MCS) in hyperthyroid cats. Four hundred sixty-two cats with untreated hyperthyroidism, 117 of which were reevaluated after treatment. Prospective cross-sectional and before-after studies. Untreated hyperthyroid cats had body composition evaluated (body weight, BCS, and MCS). A subset of these cats were reevaluated 3-12 months after treatment when euthyroid. Pretreatment body weight (median, 4.36 kg; IQR, 3.5 to 5.2 kg) was lower than premorbid weight (5.45 kg; IQR, 4.6 to 6.4 kg, P < .0001) recorded 1-2 years before diagnosis. 154 (35.3%) cats were thin or emaciated; 357 (77.3%) had loss of muscle mass. Cats showed increases in body weight (median, 4.1 kg to 5.0 kg), BCS (median, 3/5 to 3.5/5), and MCS (2/3 to 3/3) after treatment (P < .001), but mild-to-moderate muscle wasting persisted in 45% of treated cats. Most hyperthyroid cats lose body weight but maintain an ideal or overweight BCS, with only a third being underweight. As in human hyperthyroid patients, this weight loss is associated with muscle wasting, which affects >75% of hyperthyroid cats. Successful treatment leads to weight gain and increase of BCS in most cats, but almost half fail to regain normal muscle mass. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  12. Genetics, biometrics and the informatization of the body.

    PubMed

    van der Ploeg, Irma

    2007-01-01

    "Genetics" is a term covering a wide set of theories, practices, and technologies, only some of which overlap with the practices and technologies of biometrics. In this paper some current technological developments relating to biometric applications of genetics will be highlighted. Next, the author will elaborate the notion of the informatization of the body, by means of a brief philosophical detour on the dualisms of language and reality, words and things. In the subsequent sections she will then draw out some of the questions relevant to the purposes of Biometrics Identification Technology Ethics (BITE), and discuss the ethical problems associated with the informatization of the body. There are, however some problems and limitations to the currently dominant ethical discourse to deal with all things ethical in relation to information technology in general, and biometrics or genetics in particular. The final section will discuss some of these meta-problems.

  13. Feminist Psychology and the "Body Problem": Sexuality, Physical Appearance, and Women's Physical and Mental Health

    ERIC Educational Resources Information Center

    Chrisler, Joan C.

    2011-01-01

    Reductionistic, misogynistic, and heterosexist views of women's bodies have been often expressed and widely shared, and psychology has not been immune to those views. Second-wave feminist psychologists had plenty of work to do to normalize and destigmatize women's bodies and to point out that cultural pressures, social constructions, and…

  14. Retrograde resonance in the planar three-body problem

    NASA Astrophysics Data System (ADS)

    Morais, M. H. M.; Namouni, F.

    2013-12-01

    We continue the investigation of the dynamics of retrograde resonances initiated in Morais and Giuppone (Mon Notices R Astron Soc 424:52-64, doi:10.1111/j.1365-2966.2012.21151.x, 2012). After deriving a procedure to deduce the retrograde resonance terms from the standard expansion of the three-dimensional disturbing function, we concentrate on the planar problem and construct surfaces of section that explore phase-space in the vicinity of the main retrograde resonances (2/1, 1/1 and 1/2). In the case of the 1/1 resonance for which the standard expansion is not adequate to describe the dynamics, we develop a semi-analytic model based on numerical averaging of the unexpanded disturbing function, and show that the predicted libration modes are in agreement with the behavior seen in the surfaces of section.

  15. On the motion of a body whose dynamical structure is variable

    NASA Astrophysics Data System (ADS)

    Kolbut, V. R.

    1982-02-01

    Abul'naga and Barkin (1980) have considered the problem of the particular solutions for the translational-rotational motion of two rigid bodies, taking into account the third harmonics in the force function of their Newtonian interaction. Attention is given to the Hamiltonian of the problem, the distinctive motion of a body whose dynamical structure is variable, and the introduction of a known function of an independent variable. The solutions may be written in the form of a series. In the stationary case the solutions are the same as those provided by Abul'naga and Barkin. The variation in the dynamical structure of a constant-mass body may occur either because of changes in the density asymmetry or through redistribution of mass within the body. This last case is relevant to the analysis of effects arising from deformation of the body. One instance of a small distortion of this kind would be the tidal deformation of the earth.

  16. Psychological problems, self-esteem and body dissatisfaction in a sample of adolescents with brain lesions: A comparison with a control group.

    PubMed

    Pastore, Valentina; Colombo, Katia; Maestroni, Deborah; Galbiati, Susanna; Villa, Federica; Recla, Monica; Locatelli, Federica; Strazzer, Sandra

    2015-01-01

    This study aims to describe psychological problems, self-esteem difficulties and body dissatisfaction in a sample of adolescents with acquired brain lesions and to compare them with an age- and gender-matched control group. In an experimental design, the psychological profile of 26 adolescents with brain lesions of traumatic or vascular aetiology, aged 12-18 years, was compared with that of 18 typically-developing subjects. Moreover, within the clinical group, patients with TBI were compared with patients with vascular lesions. The psychological and adaptive profile of the adolescents was assessed by a specific protocol, including CBCL, VABS, RSES, EDI-2 and BES. Adolescents with brain lesions showed more marked psychological problems than their healthy peers; they also presented with a greater impairment of adaptive skills and a lower self-esteem. No significant differences were found between patients with traumatic lesions and patients with vascular lesions. Adolescents with acquired brain lesions were at higher risk to develop psychological and behavioural difficulties. Furthermore, in the clinical sample, some variables such as the long hospitalization and isolation from family and peers were associated to a greater psychological burden than the aetiology of the brain damage.

  17. Influential sources affecting Bangkok adolescent body image perceptions.

    PubMed

    Thianthai, Chulanee

    2006-01-01

    The study of body image-related problems in non-Western countries is still very limited. Thus, this study aims to identify the main influential sources and show how they affect the body image perceptions of Bangkok adolescents. The researcher recruited 400 Thai male and female adolescents in Bangkok, attending high school to freshmen level, ranging from 16-19 years, to participate in this study. Survey questionnaires were distributed to every student and follow-up interviews conducted with 40 students. The findings showed that there are eight main influential sources respectively ranked from the most influential to the least influential: magazines, television, peer group, familial, fashion trend, the opposite gender, self-realization and health knowledge. Similar to those studies conducted in Western countries, more than half of the total percentage was the influence of mass media and peer groups. Bangkok adolescents also internalized Western ideal beauty through these mass media channels. Alike studies conducted in the West, there was similarities in the process of how these influential sources affect Bangkok adolescent body image perception, with the exception of familial source. In conclusion, taking the approach of identifying the main influential sources and understanding how they affect adolescent body image perceptions can help prevent adolescents from having unhealthy views and taking risky measures toward their bodies. More studies conducted in non-Western countries are needed in order to build a cultural sensitive program, catered to the body image problems occurring in adolescents within that particular society.

  18. Human body segmentation via data-driven graph cut.

    PubMed

    Li, Shifeng; Lu, Huchuan; Shao, Xingqing

    2014-11-01

    Human body segmentation is a challenging and important problem in computer vision. Existing methods usually entail a time-consuming training phase for prior knowledge learning with complex shape matching for body segmentation. In this paper, we propose a data-driven method that integrates top-down body pose information and bottom-up low-level visual cues for segmenting humans in static images within the graph cut framework. The key idea of our approach is first to exploit human kinematics to search for body part candidates via dynamic programming for high-level evidence. Then, by using the body parts classifiers, obtaining bottom-up cues of human body distribution for low-level evidence. All the evidence collected from top-down and bottom-up procedures are integrated in a graph cut framework for human body segmentation. Qualitative and quantitative experiment results demonstrate the merits of the proposed method in segmenting human bodies with arbitrary poses from cluttered backgrounds.

  19. Studies in interactive communication. I - The effects of four communication modes on the behavior of teams during cooperative problem-solving.

    NASA Technical Reports Server (NTRS)

    Chapanis, A.; Ochsman, R. B.; Parrish, R. N.; Weeks, G. D.

    1972-01-01

    Two-man teams solved credible, 'real-world' problems for which computer assistance has been or could be useful. Conversations were carried on in one of four modes of communication: (1) typewriting, (2) handwriting, (3) voice, and (4) natural, unrestricted communication. Two groups of subjects (experienced and inexperienced typists) were tested in the typewriting mode. Performance was assessed on three classes of dependent measures: time to solution, behavioral measures of activity, and linguistic measures. Significant and meaningful differences among the communication modes were found in each of the three classes of dependent variable. This paper is concerned mainly with the results of the activity analyses. Behavior was recorded in 15 different categories. The analyses of variance yielded 34 statistically significant terms of which 27 were judged to be practically significant as well. When the data were transformed to eliminate heterogeneity, the analyses of variance yielded 35 statistically significant terms of which 26 were judged to be practically significant.

  20. Realtime Reconstruction of an Animating Human Body from a Single Depth Camera.

    PubMed

    Chen, Yin; Cheng, Zhi-Quan; Lai, Chao; Martin, Ralph R; Dang, Gang

    2016-08-01

    We present a method for realtime reconstruction of an animating human body,which produces a sequence of deforming meshes representing a given performance captured by a single commodity depth camera. We achieve realtime single-view mesh completion by enhancing the parameterized SCAPE model.Our method, which we call Realtime SCAPE, performs full-body reconstruction without the use of markers.In Realtime SCAPE, estimations of body shape parameters and pose parameters, needed for reconstruction, are decoupled. Intrinsic body shape is first precomputed for a given subject, by determining shape parameters with the aid of a body shape database. Subsequently, per-frame pose parameter estimation is performed by means of linear blending skinning (LBS); the problem is decomposed into separately finding skinning weights and transformations. The skinning weights are also determined offline from the body shape database,reducing online reconstruction to simply finding the transformations in LBS. Doing so is formulated as a linear variational problem;carefully designed constraints are used to impose temporal coherence and alleviate artifacts. Experiments demonstrate that our method can produce full-body mesh sequences with high fidelity.