Scaling of the charm cross-section and modification of charm pTp_{T} spectra at RHIC

Charm production from the direct reconstruction of $D^0$ ($D^0\to K\pi$ up to 2 GeV/$c$) and indirect lepton measurements via charm semileptonic decays ($c\to e+X$ at 0.9\textless$p_T$\textless5.0 GeV/$c$ and $c\to \mu+X$ at 0.17\textless$p_{T}$\textless0.25 GeV/$c$) at $\sqrt{s_{_{NN}}}=200$ GeV Au+Au collisions are analyzed. The transverse momentum ($p_T$) spectra and the nuclear modification factors for $D^0$ and for leptons from heavy flavor decays is presented. Scaling of charm cross-section with number of binary collisions at $\sqrt{s_{_{NN}}}=200$ GeV from d+Au to Au+Au collisions is reported.Comment: 4 pages, 4 figures, proceedings for Quark Matter 200

Three-way electrical gating characteristics of metallic Y-junction carbon nanotubes

Y-junction based carbon nanotube (CNT) transistors exhibit interesting switching behaviors, and have the structural advantage that the electrical gate for current modulation can be formed by any of the three constituent branches. In this letter, we report on the gating characteristics of metallic Y-CNT morphologies. By measuring the output conductance and transconductance we conclude that the efficiency and gain depend on the branch diameter and is electric field controlled. Based on these principles, we propose a design for a Y-junction based CNT switching device, with tunable electrical properties

The measurement of disaster risk: An example from tropical cyclones in the Philippines

What shapes people’s disaster risk exposure? Using a sub-national (provincial) panel econometric and deductive approach we answer this question by focussing on tropical cyclones, and using the Philippines as a case study for our measurement approach. We construct a new provincial level panel dataset, and use panel estimation methods to assess the influence of socioeconomic (vulnerability), geographic, demographic, topographic (exposure), and meteorological (hazard) characteristics on the resulting fatalities and affected persons from recent tropical cyclones. We find strong evidence that socioeconomic development reduces people’s vulnerability and loss of human lives. Further, good local governance is associated with fewer fatalities. Rapid and unplanned urbanization generates vulnerabilities and increases harm. Exposure, including topography, and hazard strength are likewise important determinants. However, disaster impacts on people appear to be influenced much more by vulnerability and exposure, than by the hazard itself. We quantify this difference in order to contribute to policy planning at national and sub-national scales

Application of the operator product expansion to the short distance behavior of nuclear potentials

We investigate the short distance behavior of nucleon-nucleon (NN) potentials defined through Bethe-Salpeter wave functions, by perturbatively calculating anomalous dimensions of 6-quark operators in QCD. Thanks to the asymptotic freedom of QCD, 1-loop computations give certain exact results for the potentials in the zero distance limit. In particular the functional form of the S-state central NN potential at short distance $r$ is predicted to be a little weaker than $r^{-2}$. On the other hand, due to the intriguing character of the anomalous dimension spectrum, perturbative considerations alone can not determine whether this potential is repulsive or attractive at short distances. A crude estimation suggests that the force at short distance is repulsive, as found numerically in lattice QCD. A similar behavior is found for the tensor potential.Comment: 40 pages, no figure

The 2D analogue of the Reissner-Nordstrom solution

A two-dimensional (2D) dilaton gravity model, whose static solutions have the same features of the Reissner-Nordstrom solutions, is obtained from the dimensional reduction of a four-dimensional (4D) string effective action invariant under S-duality transformations. The black hole solutions of the 2D model and their relationship with those of the 4D theory are discussed.Comment: 5 pages, Plain-Tex, no figure

Successful treatment of ciliary body medulloepithelioma with intraocular melphalan chemotherapy: a case report.

Intraocular medulloepithelioma is commonly treated with primary enucleation. Conservative treatment options include brachytherapy, local resection and/or cryotherapy in selected cases. We report for the first time the use of targeted chemotherapy to treat a ciliary body medulloepithelioma with aqueous and vitreous seeding. A 17-month-old boy with a diagnosis of ciliary body medulloepithelioma with concomitant seeding and neovascular glaucoma in the right eye was seen for a second opinion after parental refusal of enucleation. Examination under anesthesia showed multiple free-floating cysts in the pupillary area associated with iris neovascularization and a subluxated and notched lens. Ultrasound biomicroscopy revealed a partially cystic mass adjacent to the ciliary body between the 5 and 9 o'clock meridians as well as multiple nodules in the posterior chamber invading the anterior vitreous inferiorly. Fluorescein angiography demonstrated peripheral retinal ischemia. Left eye was unremarkable. Diagnosis of intraocular medulloepithelioma with no extraocular invasion was confirmed and conservative treatment initiated with combined intracameral and intravitreal melphalan injections given according to the previously described safety-enhanced technique. Ciliary tumor and seeding totally regressed after a total of 3 combined intracameral (total dose 8.1 μg) and intravitreal (total dose 70 μg) melphalan injections given every 7-10 days. Ischemic retina was treated with cryoablation as necessary. Three years later, ab interno trabeculotomy followed by 360° gonioscopy-assisted transluminal trabeculotomy 6 months later was performed for uncontrolled intraocular pressure despite antihypertensive drugs combined to cyclophotocoagulation and 7 intravitreal anti-VEGF injections for recurrent iris neovascularization. Cataract was removed at the same operative time. The child has remained disease- and metastasis-free at a 5-year follow-up since the last melphalan injection (25-month follow-up after the combined lensectomy-trabeculotomy) with a controlled intraocular pressure under topical quadritherapy and a best corrected Snellen visual acuity of 0.08. We report for the first time complete regression of a non-infiltrating ciliary body medulloepithelioma with seeding achieved with only a small number of intracameral and intravitreal melphalan injections. Concomitant secondary neovascular glaucoma and cataract needed appropriate management to allow long-term eye and vision preservation

Gaugino Condensation with S-Duality and Field-Theoretical Threshold Corrections

We study gaugino condensation in the presence of an intermediate mass scale in the hidden sector. S-duality is imposed as an approximate symmetry of the effective supergravity theory. Furthermore, we include in the K\"ahler potential the renormalization of the gauge coupling and the one-loop threshold corrections at the intermediate scale. It is shown that confinement is indeed achieved. Furthermore, a new running behaviour of the dilaton arises which we attribute to S-duality. We also discuss the effects of the intermediate scale, and possible phenomenological implications of this model.Comment: 19 pages, LaTeX, 3 postscript figures include

The Holographic Dual of 2+1 Dimensional QFTs with N=1 SUSY and Massive Fundamental Flavours

The Maldacena Nastase solution is generalised to include massive fundamental matter through the addition of a flavour profile. This gives a holographic dual to N=1 SYM-CS with massive fundamental matter with a singularity free IR. We study this solution in some detail confirming confinement and asymptotic freedom. A recently proposed solution generating technique is then applied which results in a new type-IIA supergravity solution. In a certain limit the geometry of this solution is asymptotically AdS_4X Y, where Y is the metric at the base of the Bryant-Salamon G_2 cone, which has topology S^3XS^3.Comment: 31 pages plus appendices, 6 figures. v3: Typos corrected, version to appear in JHE