361 research outputs found

    Reactive dynamics of inertial particles in nonhyperbolic chaotic flows

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    Anomalous kinetics of infective (e.g., autocatalytic) reactions in open, nonhyperbolic chaotic flows are important for many applications in biological, chemical, and environmental sciences. We present a scaling theory for the singular enhancement of the production caused by the universal, underlying fractal patterns. The key dynamical invariant quantities are the effective fractal dimension and effective escape rate, which are primarily determined by the hyperbolic components of the underlying dynamical invariant sets. The theory is general as it includes all previously studied hyperbolic reactive dynamics as a special case. We introduce a class of dissipative embedding maps for numerical verification.Comment: Revtex, 5 pages, 2 gif figure

    Pendidikan Lintas Profesional dan Kolaborasi Lintas Profesi di Pelayanan Kesehatan: Tantangan dan Peluang bagi FK-Akfis-Akper-RS UKI

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    Kebutuhan kerjasama atau kolaborasi lintas profesi di pelayanan kesehatan sangat tinggi karena memang seringkali situasi dan kondisi di lapangan membutuhkan hal itu. Pasien pasca stroke misalnya, selain dia masih membutuhkan perawatan atau penanganan oleh dokter ahli syaraf atau penyakit dalam seringkali juga membutuhkan pelayanan dari fisioterapis atau seorang perawat jiwa dan psikoterapi oleh psikiater untuk menangani masalah psikologi pasien tersebut.(Reeves & Lewin, 2004) (McCallin, 2001). Masalah atau “mitos” yang seringkali mengemuka dalam kolaborasi pelayanan kesehatan antara lain, bahwa kolaborasi lintas profesi bisa terjadi begitu saja secara alamiah. Para pelaksana pelayanan kesehatan secara otomatis paham dan mampu melakukan kolaborasi dengan tujuan utama peningkatan pelayanan kepada pasien, apalagi filosofi pelayanan saat ini sudah mengarah ke pelayanan berpusatkan pada pasien (patient-centred health services)

    Observational constraints on holographic dark energy with varying gravitational constant

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    We use observational data from Type Ia Supernovae (SN), Baryon Acoustic Oscillations (BAO), Cosmic Microwave Background (CMB) and observational Hubble data (OHD), and the Markov Chain Monte Carlo (MCMC) method, to constrain the cosmological scenario of holographic dark energy with varying gravitational constant. We consider both flat and non-flat background geometry, and we present the corresponding constraints and contour-plots of the model parameters. We conclude that the scenario is compatible with observations. In 1σ\sigma we find ΩΛ0=0.720.03+0.03\Omega_{\Lambda0}=0.72^{+0.03}_{-0.03}, Ωk0=0.00130.0040+0.0130\Omega_{k0}=-0.0013^{+0.0130}_{-0.0040}, c=0.800.14+0.19c=0.80^{+0.19}_{-0.14} and ΔGG/G=0.00250.0050+0.0080\Delta_G\equiv G'/G=-0.0025^{+0.0080}_{-0.0050}, while for the present value of the dark energy equation-of-state parameter we obtain w0=1.040.20+0.15w_0=-1.04^{+0.15}_{-0.20}.Comment: 12 pages, 2 figures, version published in JCA

    Characterization of staphylococcal cassette chromosome mec elements from methicillin-resistant Staphylococcus pseudintermedius infections in Australian animals

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    We examined the oxacillin resistance phenotype and genomic structure of staphylococcal cassette chromosome mec (SCCmec) elements from 77 veterinary methicillin-resistant Staphylococcus pseudintermedius (MRSP) isolates. Isolates were characterized by oxacillin broth microdilution, whole-genome sequencing, and bioformatics analysis. Five previously described SCCmec elements, and a sixth novel element, were identified: SCCmec III (also known as II-III), ΨSCCmec57395, and SCCmecNA45 (a SCCmec VII variant), all previously described in MRSP, and SCCmec IVg and SCCmec VT, previously described in both methicillin-resistant Staphylococcus aureus (MRSA) and MRSP. The sixth element was novel and found among nine geographically clustered isolates. This novel pseudostaphylococcal cassette chromosome (ΨSCCmecKW21) contained a class A mec gene complex but lacked ccr genes. It also harbored heavy metal (cadmium) resistance determinants. The median oxacillin MIC values among ΨSCCmecKW21, SCCmec III, and SCCmec VT isolates were significantly higher than those determined for the SCCmecNA45 VII variant isolates and ΨSCCmec57395 and SCCmec IVg isolates. ΨSCCmecKW21 was found exclusively in sequence type 497 (ST497), an MRSP clone that is locally successful in Victoria, Australia. Future studies are necessary to determine if this clone has disseminated further afield and if ΨSCCmecKW21 has moved into other MRSP lineages or staphylococcal species. IMPORTANCE Staphylococcus pseudintermedius is a significant veterinary pathogen and occasional cause of infections in humans. β-Lactams are an important group of antimicrobials used to treat staphylococcal infections in humans and animals. However, when staphylococci become methicillin resistant via the acquisition of a mobile genetic element called staphylococcal cassette chromosome mec (SCCmec), they become resistant to all β-lactams. This study detected a novel SCCmec element among a cluster of methicillin-resistant S. pseudintermedius isolates from animals in Australia. It also detected SCCmec elements in S. pseudintermedius that had high similarity to those identified in methicillin-resistant Staphylococcus aureus, demonstrating how human and animal pathogens can share the same resistance determinants

    Surface and capillary transitions in an associating binary mixture model

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    We investigate the phase diagram of a two-component associating fluid mixture in the presence of selectively adsorbing substrates. The mixture is characterized by a bulk phase diagram which displays peculiar features such as closed loops of immiscibility. The presence of the substrates may interfere the physical mechanism involved in the appearance of these phase diagrams, leading to an enhanced tendency to phase separate below the lower critical solution point. Three different cases are considered: a planar solid surface in contact with a bulk fluid, while the other two represent two models of porous systems, namely a slit and an array on infinitely long parallel cylinders. We confirm that surface transitions, as well as capillary transitions for a large area/volume ratio, are stabilized in the one-phase region. Applicability of our results to experiments reported in the literature is discussed.Comment: 12 two-column pages, 12 figures, accepted for publication in Physical Review E; corrected versio

    Effect of stress-triaxiality on void growth in dynamic fracture of metals: a molecular dynamics study

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    The effect of stress-triaxiality on growth of a void in a three dimensional single-crystal face-centered-cubic (FCC) lattice has been studied. Molecular dynamics (MD) simulations using an embedded-atom (EAM) potential for copper have been performed at room temperature and using strain controlling with high strain rates ranging from 10^7/sec to 10^10/sec. Strain-rates of these magnitudes can be studied experimentally, e.g. using shock waves induced by laser ablation. Void growth has been simulated in three different conditions, namely uniaxial, biaxial, and triaxial expansion. The response of the system in the three cases have been compared in terms of the void growth rate, the detailed void shape evolution, and the stress-strain behavior including the development of plastic strain. Also macroscopic observables as plastic work and porosity have been computed from the atomistic level. The stress thresholds for void growth are found to be comparable with spall strength values determined by dynamic fracture experiments. The conventional macroscopic assumption that the mean plastic strain results from the growth of the void is validated. The evolution of the system in the uniaxial case is found to exhibit four different regimes: elastic expansion; plastic yielding, when the mean stress is nearly constant, but the stress-triaxiality increases rapidly together with exponential growth of the void; saturation of the stress-triaxiality; and finally the failure.Comment: 35 figures, which are small (and blurry) due to the space limitations; submitted (with original figures) to Physical Review B. Final versio

    Observational constraint on generalized Chaplygin gas model

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    We investigate observational constraints on the generalized Chaplygin gas (GCG) model as the unification of dark matter and dark energy from the latest observational data: the Union SNe Ia data, the observational Hubble data, the SDSS baryon acoustic peak and the five-year WMAP shift parameter. It is obtained that the best fit values of the GCG model parameters with their confidence level are As=0.730.06+0.06A_{s}=0.73^{+0.06}_{-0.06} (1σ1\sigma) 0.09+0.09^{+0.09}_{-0.09} (2σ)(2\sigma), α=0.090.12+0.15\alpha=-0.09^{+0.15}_{-0.12} (1σ1\sigma) 0.19+0.26^{+0.26}_{-0.19} (2σ)(2\sigma). Furthermore in this model, we can see that the evolution of equation of state (EOS) for dark energy is similar to quiessence, and its current best-fit value is w0de=0.96w_{0de}=-0.96 with the 1σ1\sigma confidence level 0.91w0de1.00-0.91\geq w_{0de}\geq-1.00.Comment: 9 pages, 5 figure

    Resonance Superfluidity: Renormalization of Resonance Scattering Theory

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    We derive a theory of superfluidity for a dilute Fermi gas that is valid when scattering resonances are present. The treatment of a resonance in many-body atomic physics requires a novel mean-field approach starting from an unconventional microscopic Hamiltonian. The mean-field equations incorporate the microscopic scattering physics, and the solutions to these equations reproduce the energy-dependent scattering properties. This theory describes the high-TcT_c behavior of the system, and predicts a value of TcT_c which is a significant fraction of the Fermi temperature. It is shown that this novel mean-field approach does not break down for typical experimental circumstances, even at detunings close to resonance. As an example of the application of our theory we investigate the feasibility for achieving superfluidity in an ultracold gas of fermionic 6^6Li.Comment: 15 pages, 10 figure
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