Two-Photon Beatings Using Biphotons Generated from a Two-Level System

We propose a two-photon beating experiment based upon biphotons generated from a resonant pumping two-level system operating in a backward geometry. On the one hand, the linear optical-response leads biphotons produced from two sidebands in the Mollow triplet to propagate with tunable refractive indices, while the central-component propagates with unity refractive index. The relative phase difference due to different refractive indices is analogous to the pathway-length difference between long-long and short-short in the original Franson interferometer. By subtracting the linear Rayleigh scattering of the pump, the visibility in the center part of the two-photon beating interference can be ideally manipulated among [0, 100%] by varying the pump power, the material length, and the atomic density, which indicates a Bell-type inequality violation. On the other hand, the proposed experiment may be an interesting way of probing the quantum nature of the detection process. The interference will disappear when the separation of the Mollow peaks approaches the fundamental timescales for photon absorption in the detector.Comment: to appear in Phys. Rev. A (2008

Inhaled treprostinil: a therapeutic review

Pulmonary arterial hypertension (PAH) is a life-threatening disease which, if untreated, leads to right ventricular failure and often death. Several effective therapies are now available for PAH, including endothelin receptor antagonists, phosphodiesterase-5 inhibitors, and prostacyclin analogs. The prostacyclin analog treprostinil has proven efficacious when delivered by subcutaneous or intravenous infusion, and most recently by inhalation. Inhaled treprostinil has been shown to be 64%–72% bioavailable in healthy volunteers. Pilot clinical studies have elucidated the acute hemodynamic effects and relative pulmonary selectivity of this agent, as well as established target dosing in PAH and nonoperable chronic thromboembolic PAH. Likewise, chronically administered inhaled treprostinil resulted in clinical and hemodynamic improvement. Both pilot studies confirmed a satisfactory safety profile in patients with PAH. The pivotal Phase III trial, TRIUMPH-I, demonstrated the efficacy and safety of inhaled treprostinil (target dose of 54 μg four times daily) in PAH patients added to background therapies of bosentan or sildenafil, as assessed by improvements in the primary endpoint, peak six-minute walk distance (median placebo-corrected treatment effect of 20 m), as well as select secondary endpoints. Inhaled treprostinil is approved by the US Food and Drug Administration for patients with World Health Organization Group I PAH to improve exercise ability. Studies establishing effectiveness included predominately patients with New York Heart Association functional class III symptoms and etiologies of idiopathic or heritable PAH (56%) or PAH associated with connective tissue diseases (33%)

Ghost Interference with Optical Parametric Amplifier

The 'Ghost' interference experiment is analyzed when the source of entangled photons is a multimode Optical Parametric Amplifier(OPA) whose weak limit is the two-photon Spontaneous Parametric Downconversion(SPDC) beam. The visibility of the double-slit pattern is calculated, taking the finite coincidence time window of the photon counting detectors into account. It is found that the coincidence window and the bandwidth of light reaching the detectors play a crucial role in the loss of visibility on coincidence detection, not only in the 'Ghost' interference experiment but in all experiments involving coincidence detection. The differences between the loss of visibility with two-mode and multimode OPA sources is also discussed. PACS: 42.65.Yj, 42.50.Dv, 42.65.L

Anomalous thermal conductivity and local temperature distribution on harmonic Fibonacci chains

The harmonic Fibonacci chain, which is one of a quasiperiodic chain constructed with a recursion relation, has a singular continuous frequency-spectrum and critical eigenstates. The validity of the Fourier law is examined for the harmonic Fibonacci chain with stochastic heat baths at both ends by investigating the system size N dependence of the heat current J and the local temperature distribution. It is shown that J asymptotically behaves as (ln N)^{-1} and the local temperature strongly oscillates along the chain. These results indicate that the Fourier law does not hold on the harmonic Fibonacci chain. Furthermore the local temperature exhibits two different distribution according to the generation of the Fibonacci chain, i.e., the local temperature distribution does not have a definite form in the thermodynamic limit. The relations between N-dependence of J and the frequency-spectrum, and between the local temperature and critical eigenstates are discussed.Comment: 10 pages, 4 figures, submitted to J. Phys.: Cond. Ma

Diagnostic des eaux de surface. Application du système modulaire gradué au Boiron de Morges

Les variations hydro-climatiques et anthropiques actuelles et prévues dans le futur interrogent sur l’évolution de l’état écologique des cours d’eau. Il est donc crucial de développer des outils prenant en compte les dimensions quantitatives et qualitatives des ressources en eau. C’est le cas du système modulaire gradué proposé par l’Office fédéral de l’environnement. Cet article présente un retour d’expérience sur la mise en oeuvre de ce système, appliqué au Boiron de Morges, et sur sa capacité à identifier la variabilité spatio-temporelle des enjeux écologiques

An Investigation of a Method for the Analysis of Smokes According to Particle Size

An electrical precipitation method for the analysis of smokes according to particle size has been investigated. A thin stream of smoke particles moving under laminar conditions in a wind tunnel of rectangular cross section is electrically charged in a small region. The charged particles are then precipitated by the uniform field existing between the charged upper plate and the grounded lower plate of the wind tunnel as a long track along the lower plate. The size-frequency distributions of the particles precipitated at various points on the lower plate were determined from measurements on enlargements of electron-microscope photographs of samples of the smoke precipitated at various points. The agreement between theory and experiment is fair, but the range of sizes of the particles precipitated at a given point is rather large

Possible Signature of Low Scale Gravity in Ultra High Enegry Cosmic Rays

We show that the existence of low scale gravity at TeV scale could lead to a direct production of photons with energies above 10^22 eV due to annihilation of ultra high energy neutrinos on relic massive neutrinos of the galactic halo. Air showers initialized in the terrestrial atmosphere by these ultra energetic photons could be collected in near future by the new generation of cosmic ray experiments.Comment: 5 pages, 3 figure

Fault and magmatic interaction within Iceland's western rift over the last 9kyr

We present high-resolution 'Chirp' sub-bottom profiler data from Thingvallavatn, a lake in Iceland's western rift zone. These data are combined with stratigraphic constraints from sediment cores to show that movement on normal faults since 9 ka are temporally correlated with magmatic events, indicating that movements were controlled by episodic dyke intrusion. Sediment depo-centres and the focus of subsidence migrated westwards over 3-4 kyr towards the locus of subsequent brittle failure. We interpret this subsidence as related to dyke intrusion a few km along strike, originating from the Hengill volcanic system, which occurred prior to major dyking, faulting and subsidence within the lake at 1.9 ka

Computation of saddle type slow manifolds using iterative methods

This paper presents an alternative approach for the computation of trajectory segments on slow manifolds of saddle type. This approach is based on iterative methods rather than collocation-type methods. Compared to collocation methods, that require mesh refinements to ensure uniform convergence with respect to $\epsilon$, appropriate estimates are directly attainable using the method of this paper. The method is applied to several examples including: A model for a pair of neurons coupled by reciprocal inhibition with two slow and two fast variables and to the computation of homoclinic connections in the FitzHugh-Nagumo system.Comment: To appear in SIAM Journal of Applied Dynamical System