87,574 research outputs found
“The Dynamic variable angle hip screw (D.M.S.) vs Gamma Nail in the management of intertrochanteric hip fractures. A comparative prospective study.”
No full textU. Tarantino MD, F. OLIVA MD, A. Impagliazzo MD, A. Mattei MD, G. Cannata MD, G.F. Spurio Pompili MD, N. Maffulli MD, MS, PhD, FRCS(Orth).
“The Dynamic variable angle hip screw (D.M.S.) vs Gamma Nail in the management of intertrochanteric hip fractures. A comparative prospective study.” Disability and Rehabilitation 2005; 27(18-19): 1157 - 116
Dynamics of lagoon ecosystems
No full textThe dynamic behaviour of a lagoon ecosystem is investigated by using an eutrophication model. The phosphorous external load is assumed as control parameter. The response diagram, obtained by simulation, varying the value of control parameter, shows the existence of different ranges of stability of the ecosystem, characterized by the dominance of a specific group of primary produces and by a different ecosystem vulnerability to Summer water anoxia. A catastrophic bifurcation occurs for a critical value of the control parameter, which manifests as an abrupt change of the dominant specie from eelgrass to macroalgae. The serious consequences of such a selection in terms of eutrophication processes, anoxic crisis vulnerability and management policies for ecosystems subject to alternate states are emphasised
Numerical integration of the contravariant form of the two phase flow motion equations
No full textReservoirs (which are created by the artificial barrage of watercourses) gradually lose the capacity to store water resources owing to the progressive accumulation of solid particles, which are transported by the watercourses, on the bed. In conditions characterized by a flood with a high capacity for transporting large quantities of solid material, turbidity currents could occur; in these situations and in the presence of a steep bed slope, the turbidity currents can reach the bottom outlets. In this paper a model for the simulation of the turbidity currents is proposed; the model is based on the numerical integration of the two phase flow motion equations. These equations are integrated on a three-dimensional generalised curvilinear grid and are directly expressed in contravariant formulation. The numerical procedure adopted is based on a fractional step method and the proposed numerical scheme is conservative and fourth order accurate. The numerical model is validated by comparison between the numerical results and experimental data and is applied to the reservoir of Pieve di Cadore (Italy), in order to verify the possibility of the production of turbidity currents and the possibility of using the bottom outlet to discharge downstream the solid material that reaches the reservoir during flood events
Scattering by PT-Symmetric Non-Local Potentials
No full textA general formalism is worked out for the description of one-dimensional scattering by separable non-local potentials and constraints on transmission and reflection coefficients are derived in the cases of P, T, or PT invariance of the Hamiltonian. The one-dimensional Yamaguchi potential is discussed in detail
Reflectionless PT-Symmetric Potentials in the One-dimensional Dirac Equation
No full textWe study the one-dimensional Dirac equation with local PT-symmetric potentials whose discrete eigenfunctions and continuum asymptotic eigenfunctions are eigenfunctions of the PT operator, too: on these conditions, the bound-state spectra are real and the potentials are reflectionless and conserve unitarity in the scattering process. The absence of reflection makes it meaningful to consider also PT-symmetric potentials that do not vanish asymptotically
Overcritical PT-Symmetric Square Well Potential in the Dirac Equation
No full textWe study scattering properties of a PT-symmetric square well potential with real depth larger than the threshold of particle-antiparticle pair production as the time component of a vector potential in the Dirac equation. Spontaneous pair production inside the well becomes tiny beyond the strength at which discrete bound states with real energies disappear, consistently with a spontaneous breakdown of PT symmetry
Networks of cosmological histories, crossing of the phantom divide line and potentials with cusps.
No full textWe discuss the phenomenon of the smooth dynamical gravity induced crossing of the phantom divide line in a framework of simple cosmological models where it appears to occur rather naturally, provided the potential of the unique scalar field has some kind of cusp. The behavior of cosmological trajectories in the vicinity of the cusp is studied in some detail and a simple mechanical analogy is presented. The phenomenon of certain complementarity between the smoothness of the spacetime geometry and matter equations of motion is elucidated. We introduce a network of cosmological histories and qualitatively describe some of its properties
Non-local PT-Symmetric Potentials in the One-Dimensional Dirac Equation
No full textThe Dirac equation in (1+1) dimensions with a non-local PT-symmetric potential of separable type is studied by means of the Green's function method: properties of bound and scattering states are derived in full detail and numerical results are shown for a potential kernel of Yamaguchi type, inspired by the treatment of low-energy nucleon-nucleon interaction
Chameleon Cosmology Model Describing the Phantom Divide Line Crossing.
No full textAn exact solution describing the evolution of the type Bang-to-Rip with the phantom divide line crossing is constructed in the Chameleon cosmology model, based on two independent functions of the scalar field
Analytical evaluation of the Tosoh HLC-723 G7 automated HPLC analyzer for hemoglobin A2 and F determination
No full textObjectives: The analytical performance of a new automated HPLC system (Tosoh HLV-723 G7) for Hb A2 and Hb F quantification in blood was studied. Design and methods: Hb A2 and Hb F measurements were studied for imprecision, linearity, carry-over, interferences and sample concentration effect. Method comparison study was performed with the Bio-Rad Variant II HPLC system. Hb F results were also compared with those obtained by the alkaline denaturation test. The detection of some common Hb variants was also studied. Results: Hb A2 within-run and between-run CVs were found between 0.8–2.2 % and 2.9–7.2 %, respectively, while CVs for Hb F were up to 10.0 % in normal and between 1.9–5.3 % at more clinically relevant Hb F concentrations (N1.5 %). Comparison study with Bio-Rad Variant II for Hb A2 determination showed good correlation but highlighted calibration differences. The following results were obtained in two different laboratories: y = 1.163x 0.52, r = 0.9918, n = 144 (Lab A); y = 1.060x 0.40, r = 0.9920, n = 93 (Lab B). With regard to the determination of Hb F, the measurements performed by the tested method was found to correlate well with the alkaline denaturation test ( y = 1.0138x 0.36, r = 0.9842, n = 20) and with the Variant II HPLC system ( y = 0.812x + 0.52, r = 0.9835, n = 110). An excellent linearity (r = 0.999) was found for both Hb A2 and Hb F in the range 0.8–19 %. Hb S, Hb C and Hb D can be presumptively identified by the assigned retention time windows. Conclusion: The new analyzer Tosoh HLV-723 G7 was found to be a reliable method for Hb A2 and Hb F quantification and for the presumptive identification of some common Hb variants
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