A Transmissable Erosive Gastro-Enteritis of Cattle

A Widespread ocurrence of an unusual disease of cattle has appeared in Indiana dairy and beef herds. It was characterized clinically by fever, nasal discharge, erosions of the buccal mucosa, lameness, cough and profuse diarrhea and at necropsy by congestion, hemorrhages and erosions of the mucosa of the entire digestive tract and congestion of the upper portion of the respiratory system. The disease was readily transmitted to calves both by direct and indirect contact and by inoculation of filtrates of blood obtained from affected animals. It has been called transmissible erosive gastroenteritis of cattle

Optical Weak Link between Two Spatially Separate Bose-Einstein Condensates

Two spatially separate Bose-Einstein condensates were prepared in an optical double-well potential. A bidirectional coupling between the two condensates was established by two pairs of Bragg beams which continuously outcoupled atoms in opposite directions. The atomic currents induced by the optical coupling depend on the relative phase of the two condensates and on an additional controllable coupling phase. This was observed through symmetric and antisymmetric correlations between the two outcoupled atom fluxes. A Josephson optical coupling of two condensates in a ring geometry is proposed. The continuous outcoupling method was used to monitor slow relative motions of two elongated condensates and characterize the trapping potential.Comment: 4 pages, 5 figure

Bolometric and UV Light Curves of Core-Collapse Supernovae

The Swift UV-Optical Telescope (UVOT) has been observing Core-Collapse Supernovae (CCSNe) of all subtypes in the UV and optical since 2005. We present here 50 CCSNe observed with the Swift UVOT, analyzing their UV properties and behavior. Where we have multiple UV detections in all three UV filters (\lambda c = 1928 - 2600 \AA), we generate early time bolometric light curves, analyze the properties of these light curves, the UV contribution to them, and derive empirical corrections for the UV-flux contribution to optical-IR based bolometric light curves

Quantum reflection of atoms from a solid surface at normal incidence

We observed quantum reflection of ultracold atoms from the attractive potential of a solid surface. Extremely dilute Bose-Einstein condensates of ^{23}Na, with peak density 10^{11}-10^{12}atoms/cm^3, confined in a weak gravito-magnetic trap were normally incident on a silicon surface. Reflection probabilities of up to 20 % were observed for incident velocities of 1-8 mm/s. The velocity dependence agrees qualitatively with the prediction for quantum reflection from the attractive Casimir-Polder potential. Atoms confined in a harmonic trap divided in half by a solid surface exhibited extended lifetime due to quantum reflection from the surface, implying a reflection probability above 50 %.Comment: To appear in Phys. Rev. Lett. (December 2004)5 pages, 4 figure

Phase Sensitive Recombination of Two Bose-Einstein Condensates on an Atom Chip

The recombination of two split Bose-Einstein condensates on an atom chip is shown to result in heating which depends on the relative phase of the two condensates. This heating reduces the number of condensate atoms between 10 and 40% and provides a robust way to read out the phase of an atom interferometer without the need for ballistic expansion. The heating may be caused by the dissipation of dark solitons created during the merging of the condensates.Comment: 5 pages, 4 figure

Normal and Reverse Faulting Driven by the Subduction Zone Earthquake Cycle in the Northern Chilean Forearc

Despite its location in a convergent tectonic setting, the Coastal Cordillera of northern Chile between 21°S and 25°S is dominated by structures demonstrating extension in the direction of plate convergence. In some locations, however, normal faults have been reactivated as reverse faults, complicating the interpretation of long-term strain. In order to place these new observations in a tectonic context, we model stress changes induced on these faults by the subduction earthquake cycle. Our simulations predict that interseismic locking on the plate boundary encourages normal slip on fore-arc faults, which may result from elastic rebound due to interplate earthquakes or from seismic or aseismic motion that takes place within the interseismic period. Conversely, stress generated by strong subduction zone earthquakes, such as the 1995 Mw = 8.1 Antofagasta event, provides a mechanism for the reverse reactivation we document here. Upper plate fault slip in response to the low-magnitude stress changes induced by the subduction earthquake cycle suggests that the absolute level of stress on these faults is very low. Furthermore, seismic hazard analysis for northern Chile requires consideration of not only the plate boundary earthquake cycle but also the cycle on fore-arc faults that may or may not coincide with the interplate pattern. Though the relationships between permanent strain and deformation calculated using elastic models remain unclear, the compatibility of modeled stress fields with the distribution of fore-arc faulting suggests that interseismic strain accumulation and coseismic deformation on the subduction megathrust both play significant roles in shaping structural behavior in the upper plate