136 research outputs found
Totally geodesic horizontally conformal maps
We obtain a characterization of totally geodesic horizontally conformal
maps by a method which arises as a consequence of the Bochner technique
for harmonic morphisms. As a geometric consequence we show that the
existence of a non-constant harmonic morphism from a
compact Riemannian manifold M of non-negative Ricci curvature
to a compact Riemannian manifold of non-positive scalar curvature,
forces M either to be a global Riemannian product of integral
manifolds of vertical and horizontal distributions or to be covered
by a global Riemannian product
Long-term outcomes of omniflow II biosynthetic vascular graft in lower extremity arterial revascularization
Background: This study aims to evaluate the patency rates and long-term outcomes of femoro-popliteal bypass procedures with Omniflow II biosynthetic vascular grafts in patients with occlusive vascular disease. Methods: This retrospective, observational, clinical study included a total of 93 patients (61 males, 32 females; mean age 56.9±7.4 years; range, 43 to 83 years) who underwent femoro-popliteal bypass in which Omniflow II biosynthetic vascular grafts were used due to peripheral arterial disease. The patients were divided into two groups: 62 patients undergoing femoro-popliteal above-knee bypass and 31 patients undergoing the femoro-popliteal belowknee bypass. We evaluated preoperative clinical characteristics, postoperative graft patency rates, and other clinical results. Results: The mean follow-up was 44.9±18.8 months in the femoropopliteal above-knee bypass group and 47.3±22.3 months in the femoro-popliteal below-knee bypass group (p=0.302). The cumulative primary graft patency rates of the femoro-popliteal above-knee bypass and femoro-popliteal below-knee bypass groups at three, four, and five years were 98%, 95% and 78% and 86%, 75% and 45%, respectively (log-rank; p=0.312). The cumulative assisted graft patency rates of the femoro-popliteal above-knee bypass and femoro-popliteal below-knee bypass groups at five years were 87.9% and 65.3%, respectively (log-rank; p=0.530). Conclusion: The Omniflow II biosynthetic vascular graft is suitable for above-and below-knee femoro-popliteal bypass procedures. These grafts may be prefered due to high patency rates, low incidence of aneursym formations, and infections. ©2018 All right reserved by the Turkish Society of Cardiovascular Surgery
Simultaneous solutions for first order and second order slips on micropolar fluid flow across a convective surface in the presence of Lorentz force and variable heat source/sink
This report presents the flow and heat transfer characteristics of MHD micropolar fluid due to the stretching of a surface with second order velocity slip. The influence of nonlinear radiation and irregular heat source/sink are anticipated. Simultaneous solutions are presented for first and second-order velocity slips. The PDEs which govern the flow have been transformed as ODEs by the choice of suitable similarity transformations. The transformed nonlinear ODEs are converted into linear by shooting method then solved numerically by fourth-order Runge-Kutta method. Graphs are drowned to discern the effect of varied nondimensional parameters on the flow fields (velocity, microrotation, and temperature). Along with them the coefficients of Skin friction, couple stress, and local Nussel number are also anticipated and portrayed with the support of the table. The results unveil that the non-uniform heat source/sink and non-linear radiation parameters plays a key role in the heat transfer performance. Also, second-order slip velocity causes strengthen in the distribution of velocity but a reduction in the distribution of temperature is perceived. - 2019, The Author(s).Scopu
Construction of S-Box based on chaotic map and algebraic structures
The Advanced Encryption Standard (AES) is widely used in different kinds of security applications. The substitution box (S-box) is the main component of many modern symmetric encryption ciphers that provides confusion between the secret key and ciphertext. The S-box component that is used in AES is fixed. If we construct this component dynamically, the encryption strength of AES would be greater than before. In this manuscript, we used chaotic logistic map, Mobius transformation and symmetric group S256 to construct S-box for AES. The idea behind the proposed work is to make supplementary safe S-box. The presented S-box is analyzed for the following analyses: linear approximation probability (LP), nonlinearity (NL), differential approximation probability (DP), strict avalanche criterion (SAC), and bit independence criterion (BIC). The analyses show that the proposed technique is useful in generating high resistance S-box to known attacksThe publication of this article was funded by the Qatar National Library
Riemannian submersions from almost contact metric manifolds
In this paper we obtain the structure equation of a contact-complex
Riemannian submersion and give some applications of this equation in the study
of almost cosymplectic manifolds with Kaehler fibres.Comment: Abh. Math. Semin. Univ. Hamb., to appea
Jet-quenching of the rotating heavy meson in a =4 SYM plasma in presence of a constant electric field
In this paper, we consider a rotating heavy quark-antiquark () pair
in a =4 SYM thermal plasma. We assume that center of
mass moves at the speed and furthermore they rotate around the center of
mass. We use the AdS/CFT correspondence and consider the effect of external
electromagnetic field on the motion of the rotating meson. Then we calculate
the jet-quenching parameter corresponding to the rotating meson in the constant
electric field
Formation of dense partonic matter in relativistic nucleus-nucleus collisions at RHIC: Experimental evaluation by the PHENIX collaboration
Extensive experimental data from high-energy nucleus-nucleus collisions were
recorded using the PHENIX detector at the Relativistic Heavy Ion Collider
(RHIC). The comprehensive set of measurements from the first three years of
RHIC operation includes charged particle multiplicities, transverse energy,
yield ratios and spectra of identified hadrons in a wide range of transverse
momenta (p_T), elliptic flow, two-particle correlations, non-statistical
fluctuations, and suppression of particle production at high p_T. The results
are examined with an emphasis on implications for the formation of a new state
of dense matter. We find that the state of matter created at RHIC cannot be
described in terms of ordinary color neutral hadrons.Comment: 510 authors, 127 pages text, 56 figures, 1 tables, LaTeX. Submitted
to Nuclear Physics A as a regular article; v3 has minor changes in response
to referee comments. Plain text data tables for the points plotted in figures
for this and previous PHENIX publications are (or will be) publicly available
at http://www.phenix.bnl.gov/papers.htm
Future and potential spending on health 2015-40: Development assistance for health, and government, prepaid private, and out-of-pocket health spending in 184 countries
Background: The amount of resources, particularly prepaid resources, available for health can affect access to health care and health outcomes. Although health spending tends to increase with economic development, tremendous variation exists among health financing systems. Estimates of future spending can be beneficial for policy makers and planners, and can identify financing gaps. In this study, we estimate future gross domestic product (GDP), all-sector government spending, and health spending disaggregated by source, and we compare expected future spending to potential future spending. Methods: We extracted GDP, government spending in 184 countries from 1980-2015, and health spend data from 1995-2014. We used a series of ensemble models to estimate future GDP, all-sector government spending, development assistance for health, and government, out-of-pocket, and prepaid private health spending through 2040. We used frontier analyses to identify patterns exhibited by the countries that dedicate the most funding to health, and used these frontiers to estimate potential health spending for each low-income or middle-income country. All estimates are inflation and purchasing power adjusted. Findings: We estimated that global spending on health will increase from US24.24 trillion (uncertainty interval [UI] 20.47-29.72) in 2040. We expect per capita health spending to increase fastest in upper-middle-income countries, at 5.3% (UI 4.1-6.8) per year. This growth is driven by continued growth in GDP, government spending, and government health spending. Lower-middle income countries are expected to grow at 4.2% (3.8-4.9). High-income countries are expected to grow at 2.1% (UI 1.8-2.4) and low-income countries are expected to grow at 1.8% (1.0-2.8). Despite this growth, health spending per capita in low-income countries is expected to remain low, at 195 (157-258) per capita in 2040. Increases in national health spending to reach the level of the countries who spend the most on health, relative to their level of economic development, would mean $321 (157-258) per capita was available for health in 2040 in low-income countries. Interpretation: Health spending is associated with economic development but past trends and relationships suggest that spending will remain variable, and low in some low-resource settings. Policy change could lead to increased health spending, although for the poorest countries external support might remain essential
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