Body composition evaluated by skinfolds, bioimpedance and body mass index in adults

El objetivo de este estudio fue comparar la composición corporal por pliegues cutáneos (DC) por bioimpedancia eléctrica(BIA) y el índice de masa corporal(IMC). Se hizo un trabajo de campo con 153 militares usando los siguientes equipos: balanza Wiso; estadiómetro WCS; adipómetro Cescorf científico y Malton BF-900 para bioimpedancia eléctrica. La densidad corporal se consiguió por la ecuación de Jackson&Pollock y la clasificación delporcentaje de grasa corporal siguiendo Pollock&Wilmore. Para verificar la correlación se usó el test de Spearman. Los resultados promedios (± desviación estándar) hallados para edad, peso, estatura e IMC, fueron: 19 años (±1,8 años), 70,9Kg (±9,55), 1,74 metros (±0.06) y 23,9 kg/m² (±2,76) respectivamente. El porcentaje de grasa corporal por DC y BIA fueron respectivamente 12,78 (±5,45); 16,29 (±4,02). Concluí que la composición corporal por el método de DC, BIA e IMC presentó datos que se correlacionan, siendo que el uso de la bioimpedancia fue más indicada en grupos cuyo porcentaje de grasa corporal variaba entre 18-20%.The aim of this study was to compare body composition by skinfold thickness (DC) by bioelectrical impedance analysis (BIA) and body mass index (BMI). Research was carried out with 153 soldiers with the equipment: balance Wiso; WCS stadiometer; adipometer Cescorf Malton scientific and BF-900 to bioelectrical impedance analysis. Body density was obtained by the equation of Jackson&Pollock and classification of the percentage of fat by following Pollock&Wilmore. To check the correlation was used Spearman's test. The average results (±standard deviation) found for age, weight, height and BMI were: 19 years (±1.8years), 70.9 kg (±9.55), 1.74 meters (±0.06) and 23.9 kg/m² (±2.76), respectively. The fat percentage by BIA and DC were respectively 12.78 (±5.45) and 16.29 (±4.02). Concluded that body composition by the method of DC, BIA and BMI have data that correlate, and the use of bioimpedance was indicated in most groups whose fat percentage ranged around 18-20%.Gracias CAPES para la inversión financiera en forma de beca en el Programa de Posgrado en Ingeniería Eléctrica e Informática Industrial (CPGEI) de la Universidad Tecnológica Federal de Paraná (UTFPR)

Self-consistent symmetries in the proton-neutron Hartree-Fock-Bogoliubov approach

Symmetry properties of densities and mean fields appearing in the nuclear Density Functional Theory with pairing are studied. We consider energy functionals that depend only on local densities and their derivatives. The most important self-consistent symmetries are discussed: spherical, axial, space-inversion, and mirror symmetries. In each case, the consequences of breaking or conserving the time-reversal and/or proton-neutron symmetries are discussed and summarized in a tabulated form, useful in practical applications.Comment: 26 RevTex pages, 1 eps figure, 9 tables, submitted to Physical Review

Strong Color Field Baryonic Remnants in Nucleus-Nucleus Collisions at 200A GeV

The effects of strong color electric fields (SCF) on the baryon production at RHIC are studied in the framework of HIJING/B\=B (v2.0) model. The particle species dependence of nuclear modification factors (NMF) are analyzed for Au+Au collisions at 200A GeV. A doubling of the string tension leading to a modification of the strangeness suppression according to Schwinger mechanism is shown to provide an alternate explanation to coalescence models for the interpretation of the observed baryon and meson production at moderate $p_T$ and results in a predicted enhancement in the (multi)strange (anti)hyperon production.Comment: 6 pages, Latex(Revtex), 4 figures;Added new references, one figure, text slightly modified. final version accepted for publication in Pnys. Rev. C (october,05

Two- and three-body color flux tubes in the Chromo Dielectric Model

Using the framework of the Chromo Dielectric Model we perform an analysis of color electric flux tubes in meson-like $q\bar{q}$ and baryon-like $qqq$ quark configurations. We discuss the Abelian color structure of the model and point out a symmetry in color space as a remnant of the SU(3) symmetry of QCD. The generic features of the model are discussed by varying the model parameters. We fix these parameters by reproducing the string tension $\tau=980$MeV/fm and the transverse width $\rho=0.35$fm of the $q\bar{q}$ flux tube obtained in lattice calculations. We use a bag constant $B^{1/4}=(240-260)$MeV, a glueball mass $m_g = (1000-1700)$MeV and a strong coupling constant $C_F \alpha_s = 0.2-0.3$. We show that the asymptotic string profile of an infinitely long flux tube is already reached for $q\bar{q}$ separations $R\ge1.0$fm. A connection to the Dual Color Superconductor is made by extracting a magnetic current from the model equations and a qualitative agreement between the two descriptions of confinement is shown. In the study of the $qqq$ system we observe a $\mathsf{\Delta}$-like geometry for the color electric fields and a \textsf{Y}-like geometry in the scalar fields both in the energy density distribution and in the corresponding potentials. The resulting total $qqq$ potential is described neither by the $\mathsf{\Delta}$-picture nor by the \textsf{Y}-picture alone.Comment: 32 pages, 35 eps-figures, revised version, some references + 1 eps-file added, to be published in Phys.Rev.

U(1) effective confinement theory from SU(2) restricted gauge theory via the Julia-Toulouse Approach

We derive an U(1) effective theory of color confinement by applying the so-called Julia-Toulouse Approach for defects condensation to the SU(2) restricted gauge theory defined by means of the Cho decomposition of the non-abelian connection. Cho's geometric construction naturally displays the topological degrees of freedom of the theory and can be used to put the Yang-Mills action into an abelianized form under certain conditions. On the other hand, the use of the Julia-Toulouse prescription to deal with the monopole condensation leads to an effective action describing the phase whose dynamics is dominated by the magnetic condensate. The effective theory we found describes the interaction between external electric currents displaying a short-range Yukawa interaction plus a linear confinement term that governs the long distance physics.Comment: 7 page

Chiral quark-soliton model in the Wigner-Seitz approximation

In this paper we study the modification of the properties of the nucleon in the nucleus within the quark-soliton model. This is a covariant, dynamical model, which provides a non-linear representation of the spontaneously broken SU(2)_L X SU(2)_R symmetry of QCD. The effects of the nuclear medium are accounted for by using the Wigner-Seitz approximation and therefore reducing the complex many-body problem to a simpler single-particle problem. We find a minimum in the binding energy at finite density, a change in the isoscalar nucleon radius and a reduction of the in-medium pion decay constant. The latter is consistent with a partial restoration of chiral symmetry at finite density, which is predicted by other models.Comment: 30 pages, 13 figures; uses REVTeX and epsfi

Electronic-structure-induced deformations of liquid metal clusters

Ab initio molecular dynamics is used to study deformations of sodium clusters at temperatures $500\cdots 1100$ K. Open-shell Na$_{14}$ cluster has two shape isomers, prolate and oblate, in the liquid state. The deformation is stabilized by opening a gap at the Fermi level. The closed-shell Na$_8$ remains magic also at the liquid state.Comment: REVTex, 11 pages, no figures, figures (2) available upon request (e-mail to hakkinen at jyfl.jyu.fi), submitted to Phys. Rev.

Toward a global description of the nucleus-nucleus interaction

Extensive systematization of theoretical and experimental nuclear densities and of optical potential strengths exctracted from heavy-ion elastic scattering data analyses at low and intermediate energies are presented.The energy-dependence of the nuclear potential is accounted for within a model based on the nonlocal nature of the interaction.The systematics indicate that the heavy-ion nuclear potential can be described in a simple global way through a double-folding shape,which basically depends only on the density of nucleons of the partners in the collision.The poissibility of extracting information about the nucleon-nucleon interaction from the heavy-ion potential is investigated.Comment: 12 pages,12 figure

Formation and control of electron molecules in artificial atoms: Impurity and magnetic-field effects

Interelectron interactions and correlations in quantum dots can lead to spontaneous symmetry breaking of the self-consistent mean field resulting in formation of Wigner molecules. With the use of spin-and-space unrestricted Hartree-Fock (sS-UHF) calculations, such symmetry breaking is discussed for field-free conditions, as well as under the influence of an external magnetic field. Using as paradigms impurity-doped (as well as the limiting case of clean) two-electron quantum dots (which are analogs to helium-like atoms), it is shown that the interplay between the interelectron repulsion and the electronic zero-point kinetic energy leads, for a broad range of impurity parameters, to formation of a singlet ground-state electron molecule, reminiscent of the molecular picture of doubly-excited helium. Comparative analysis of the conditional probability distributions for the sS-UHF and the exact solutions for the ground state of two interacting electrons in a clean parabolic quantum dot reveals that both of them describe formation of an electron molecule with similar characteristics. The self-consistent field associated with the triplet excited state of the two-electron quantum dot (clean as well as impurity-doped) exhibits symmetry breaking of the Jahn-Teller type, similar to that underlying formation of nonspherical open-shell nuclei and metal clusters. Furthermore, impurity and/or magnetic-field effects can be used to achieve controlled manipulation of the formation and pinning of the discrete orientations of the Wigner molecules. Impurity effects are futher illustrated for the case of a quantum dot with more than two electrons.Comment: Latex/Revtex, 10 pages with 4 gif figures. Small changes to explain the difference between Wigner and Jahn-Teller electron molecules. A complete version of the paper with high quality figures inside the text is available at http://shale.physics.gatech.edu/~costas/qdhelium.html For related papers, see http://www.prism.gatech.edu/~ph274c