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VERITAS Observations of Mgro J1908+06/Hess J1908+063

The unidentified TeV gamma-ray source MGRO J1908+06/HESS J1908+063 was observed with the VERITAS Imaging Atmospheric Cherenkov Array during October 2007 and May-June 2008. This extended source is located on the galactic plane at a galactic longitude of 40.45 degrees and has a hard TeV spectrum with an index of approximately 2.08. The Very High Energy (VHE) gamma-ray flux was measured by H.E.S.S. out to energies greater than 30 TeV which along with its unidentified nature makes it an interesting hard-spectrum extended source for study. We confirm the detection of VHE gamma-ray emission from this source using VERITAS.Comment: Submitted to Proceedings of "4th Heidelberg International Symposium on High Energy Gamma-Ray Astronomy 2008

Patellofemoral contact forces and pressures during intramedullary tibial nailing

Patellofemoral joint forces and pressures were measured in a cadaver model during intramedullary nailing of the tibia. A significant increase in contact pressures was found at the lateral facet of the patellofemoral articulation using the medial paratendinous approach (P= 0.01) and at the medial facet when using the trans-patellar tendon approach (P = 0.001) to the proximal tibia. Increased contact pressures at the patellofemoral joint may result in chondral injury, which in turn may cause anterior knee pain, a common complication of tibial nailing

Knowledge is power: A theory of information, income and welfare spending

No voters cast their votes based on perfect information, but better educated and richer voters are on average better informed than others. We develop a model where the voting mistakes resulting from low political knowledge reduce the weight of poor voters, and cause parties to choose political platforms that are better aligned with the preferences of rich voters. In US election survey data, we find that income is more important in affecting voting behavior for more informed voters than for less informed voters, as predicted by the model. Further, in a panel of US states we find that when there is a strong correlation between income and political information, Congress representatives vote more conservatively, which is also in line with our theory.Political Economics

721-6 Pulmonary Balloon Valvuloplasty: Effective Palliation for Infants with Tetralogy of Fallot and Small Pulmonary Arteries

Infants with tetralogy of Fallot (TOF) and small pulmonary arteries (PAs) may need palliation to improve pulmonary blood flow and allow growth of the PAs prior to complete repair. Shunts may become occluded, distort the PAs or cause pulmonary overcirculation. As an alternative palliation, we performed pulmonary balloon valvuloplasty (PBV) on infants with TOF and small PAs.20 infants, ages 1.8±1.5 mo and weights 4.1±1.6kg, undervvent PBV as initial palliation for persistent cyanosis or “spells”. 4/20 pts were intubated prior to or for PBV All pts had pre and post-PBV angiograms. In all pts, single balloon valvuloplasty was performed. The ratio of balloon: pulmonary valve annulus (PVA) diameter was 1.51±0.32. Post-PBV, there was no change in the PYA diameter (5.2±1.1mm vs 5.6 + 1.1mm; p=0.1) or PA branch diameter(4.1±1.6mm vs 4.5±1.7mm, p>0.05). The systemic 02 saturation increased from 81±8% to 93±6%. (p<0.001)7/20 pts undervvent follow-up (F/U) cath 8.2±2.4 mo post-PBV Compared to pre-PBV measurements, the PYA diameter increased from 5.2 ± 1.1mm to 7.1±1.4mm (p<0.03) and the McGoon ratio increased from 1.4±0.4 to 2.1±0.3 (p<0.02).Of the 20 pts, 11 pts undervvent corrective surgery 8.0±3.1 mo post-PBV with no surgical deaths; 5 pts remain in stable condition awaiting surgery; 3 pts required shunt placement 9-66 days post-PBV; 1 pt died due to other congenital anomalies.ConclusionsPulmonary balloon valvuloplasty promotes growth of the PAs and PYA in infants with TOF and small PAs, offering a safe and effective alternative palliation for infants who are not yet candidates for complete repair

CASIMIR: a high resolution far-IR/submm spectrometer for airborne astronomy

CASIMIR, the Caltech Airborne Submillimeter Interstellar Medium Investigations Receiver, is a far-infrared and submillimeter heterodyne spectrometer, being developed for the Stratospheric Observatory For Infrared Astronomy, SOFIA. CASIMIR will use newly developed superconducting-insulating-superconducting (SIS) mixers. Combined with the 2.5 m mirror of SOFIA, these detectors will allow observations with high sensitivity to be made in the frequency range from 500 GHz up to 1.4 THz. Initially, at least 5 frequency bands in this range are planned, each with a 4-8 GHz IF passband. Up to 4 frequency bands will be available on each flight and bands may be swapped readily between flights. The local oscillators for all bands are synthesized and tuner-less, using solid state multipliers. CASIMIR also uses a novel, commercial, field-programmable gate array (FPGA) based, fast Fourier transform spectrometer, with extremely high resolution, 22000 (268 kHz at 6 GHz), yielding a system resolution > 10^6. CASIMIR is extremely well suited to observe the warm, ≈ 100K, interstellar medium, particularly hydrides and water lines, in both galactic and extragalactic sources. We present an overview of the instrument, its capabilities and systems. We also describe recent progress in development of the local oscillators and present our first astronomical observations obtained with the new type of spectrometer

BioTIME: A Database of Biodiversity Time Series for the Anthropocene

Motivation: The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene. Main types of variables included: The database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record. Spatial location and grain: BioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 km(2) (158 cm(2)) to 100 km(2) (1,000,000,000,000 cm(2)). Time period and grainBio: TIME records span from 1874 to 2016. The minimal temporal grain across all datasets in BioTIME is a year. Major taxa and level of measurement: BioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton and terrestrial invertebrates to small and large vertebrates

Fossil Gas and the Electromagnetic Precursor of Supermassive Binary Black Hole Mergers

Using a one-dimensional height integrated model, we calculate the evolution of an unequal mass binary black hole with a coplanar gas disk that contains a gap due to the presence of the secondary black hole. Viscous evolution of the outer circumbinary disk initially hardens the binary, while the inner disk drains onto the primary (central) black hole. As long as the inner disk remains cool and thin at low $\dot{M}_{\rm ext}$ (rather than becoming hot and geometrically thick), the mass of the inner disk reaches an asymptotic mass typically \sim 10^{-3}-10^{-4}\Msun. Once the semimajor axis shrinks below a critical value, angular momentum losses from gravitational waves dominate over viscous transport in hardening the binary. The inner disk then no longer responds viscously to the inspiraling black holes. Instead, tidal interactions with the secondary rapidly drive the inner disk into the primary. Tidal and viscous dissipation in the inner disk lead to a late time brightening in luminosity $L\propto t_{\rm minus}^{5/4}$, where $t_{\rm minus}$ is the time prior to the final merger. This late time brightening peaks $\sim 1$ day prior to the final merger at $\sim 0.1 L_{\rm Edd}$. This behavior is relatively robust because of self regulation in the coupled viscous-gravitational evolution of such binary systems. It constitutes a unique electromagnetic signature of a binary supermassive black hole merger and may allow the host galaxy to be identified if used in conjunction with the Laser Interferometric Space Antenna (LISA) localization.Comment: 11 pages, 6 figures, submitted to MNRA

Construction of the Pauli-Villars-regulated Dirac vacuum in electromagnetic fields

Using the Pauli-Villars regularization and arguments from convex analysis, we construct solutions to the classical time-independent Maxwell equations in Dirac's vacuum, in the presence of small external electromagnetic sources. The vacuum is not an empty space, but rather a quantum fluctuating medium which behaves as a nonlinear polarizable material. Its behavior is described by a Dirac equation involving infinitely many particles. The quantum corrections to the usual Maxwell equations are nonlinear and nonlocal. Even if photons are described by a purely classical electromagnetic field, the resulting vacuum polarization coincides to first order with that of full Quantum Electrodynamics.Comment: Final version to appear in Arch. Rat. Mech. Analysi

Membrane Instantons and de Sitter Vacua

We investigate membrane instanton effects in type IIA strings compactified on rigid Calabi-Yau manifolds. These effects contribute to the low-energy effective action of the universal hypermultiplet. In the absence of additional fivebrane instantons, the quaternionic geometry of this hypermultiplet is determined by solutions of the three-dimensional Toda equation. We construct solutions describing membrane instantons, and find perfect agreement with the string theory prediction. In the context of flux compactifications we discuss how membrane instantons contribute to the scalar potential and the stabilization of moduli. Finally, we demonstrate the existence of meta-stable de Sitter vacua.Comment: v3: minor clarifications, JHEP version, 38 page