A Comparison of Ultraviolet, Optical, and X-Ray Imagery of Selected Fields in the Cygnus Loop

During the Astro-1 and Astro-2 Space Shuttle missions in 1990 and 1995, far ultraviolet (FUV) images of five 40' diameter fields around the rim of the Cygnus Loop supernova remnant were observed with the Ultraviolet Imaging Telescope (UIT). These fields sampled a broad range of conditions including both radiative and nonradiative shocks in various geometries and physical scales. In these shocks, the UIT B5 band samples predominantly CIV 1550 and the hydrogen two-photon recombination continuum. Smaller contri- butions are made by emission lines of HeII 1640 and OIII] 1665. We present these new FUV images and compare them with optical Halpha and [OIII], and ROSAT HRI X-ray images. Comparing the UIT images with those from the other bands provides new insights into the spatial variations and locations of these different types of emission. By comparing against shock model calculations and published FUV spectroscopy at select locations, we surmise that resonance scattering in the strong FUV permitted lines is widespread in the Cygnus Loop, especially in the bright optical filaments typically selected for observation in most previous studies.Comment: 21 pages with 10 figures. See http://www.pha.jhu.edu/~danforth/uit/ for full-resolution figure

Virus in Water. II. Evaluation of Membrane Cartridge Filters for Recovering Low Multiplicities of Poliovirus from Water

The efficiency of a Millitube MF cartridge filter, a membrane filter, for recovery of poliovirus from 100-gal volumes of both fresh (tap) and estuarine water was determined. In the high multiplicity of virus input-output experiments, recovery of 97% or greater of input virus was achieved in both types of water when the final concentration of divalent cation as Mg2+ was 1,200 μg/ml and the pH was 4.5. Virus was effectively eluted from the membrane cartridge with 5× nutrient broth in 0.05 M carbonate-bicarbonate buffer at pH 9.0. Four elutions of 250 ml each were used. In the low multiplicity of virus input-output experiments under the same cationic and pH conditions, up to 67% of the input virus was recovered when the virus was further concentrated from the eluates by the aqueous polymer two-phase separation technique. The volume reduction was 126,000-190,000 to 1. The use of the combined techniques, i.e., membrane adsorption followed by aqueous polymer two-phase separation, provided a highly sensitive, simple, and remarkably reliable sequential methodology for the quantitative recovery of poliovirus occurring at multiplicities as low as 1 to 2 plaque-forming units per 5 gal of water

Traitement efficace de l’épilepsie partielle continue avec le Félbamate

Authors report two patients with epilepsia partialis continua refractory to many pharmacological treatments who responded to Felbamate. The first patient was a 41 year-old male with a large cavernous angioma of the right hemisphere, who developed epilepsia partialis continua (EPC) with interictal Todd’s palsy in the absence of new bleeding. High doses of Primidone, Clorazepate, Topiramate, and Diazepam resulted in profound sedation but no effect on EPC. He had previously failed Phenytoin, Phenobarbital, Carbamazepine, Valproate, and Gabapentin. Felbamate was titrated up to 3600 mg/d., and EPC stopped over three days, and he regained full power in hs left hand. Felbamate was discontinued after a month, because of its potential chronic toxicity. EPC did not recur. The second patient was a 27 year-old female with EPC of the left arm since age 15. She became seizure-free on Felbamate, but when the drug became unavailable to her a year later, EPC returned, and EEG showed right polyspikes/waves of low amplitude coming from the central and anterior parietal regions, which were synchronous with her arm movements by video and EMG. She declined surgery. These cases suggest that Felbamate might be useful as a drug of last resort for pharmacoresistant EPC.Les auteurs rapportent deux patients dont l’épilepsie partielle continue (EPC) était résistante a de nombreux anticonvulsivants, et chez qui une réponse favorable a été notée sous Félbamate. Le premier patient était un home de 41 ans, qui souffrait d’un angiome caverneux occupant un gros volume dans l’hémisphère droit. Son EPC du bras droit, accompagnée d’une paralysie de Todd, ne répondit pas a des doses élevées de Primidone, Clonazepam, Clorazepate et Topiramate, qui causaient une sédation sévère. Le Felbamate fut augmenté jusqu’a 3600 mg/ jour, et l’EPC ainsi que la paralysie de Todd ont disparu, Le Félbamate fut arrêté après un mois, sans retour d’EPC. La seconde patiente était une femme de 27 ans qui souffrait d’EPC du bras droit depuis l’âge de 15 ans. L’EPC disparut sous traitement au Félbamate mais a récidivé quand ce traitement fut interrompu un an plus tard. L’EEG a montré des anomalies épileptiques da basse amplitude provenant des régions pariétales antérieurs et centrales droites, qui furent synchrones de ses mouvements du bras grâce aux données vidéo-EEG et EMG. Cette patente a refusé toute chirurgie. Ces cas suggèrent que le Félbamate, malgré sa toxicité, pourrait être considéré comme une bonne alternative dans les cas d’EPC réfractaire aux médicaments antiépileptiques usuels

Using Hierarchical Data Mining to Characterize Performance of Wireless System Configurations

This paper presents a statistical framework for assessing wireless systems performance using hierarchical data mining techniques. We consider WCDMA (wideband code division multiple access) systems with two-branch STTD (space time transmit diversity) and 1/2 rate convolutional coding (forward error correction codes). Monte Carlo simulation estimates the bit error probability (BEP) of the system across a wide range of signal-to-noise ratios (SNRs). A performance database of simulation runs is collected over a targeted space of system configurations. This database is then mined to obtain regions of the configuration space that exhibit acceptable average performance. The shape of the mined regions illustrates the joint influence of configuration parameters on system performance. The role of data mining in this application is to provide explainable and statistically valid design conclusions. The research issue is to define statistically meaningful aggregation of data in a manner that permits efficient and effective data mining algorithms. We achieve a good compromise between these goals and help establish the applicability of data mining for characterizing wireless systems performance

Unit Hydrograph Estimation for Applicable Texas Watersheds

The unit hydrograph is defined as a direct runoff hydrograph resulting from a unit pulse of excess rainfall generated uniformly over the watershed at a constant rate for an effective duration. The unit hydrograph method is a well-known hydrologic-engineering technique for estimation of the runoff hydrograph given an excess rainfall hyetograph. Four separate approaches are used to extract unit hydrographs from the database on a per watershed basis. A large database of more than 1,600 storms with both rainfall and runoff data for 93 watersheds in Texas is used for four unit hydrograph investigation approaches. One approach is based on 1-minute Rayleigh distribution hydrographs; the other three approaches are based on 5-minute gamma-distribution hydro-graphs. The unit hydrographs by watershed from the approaches are represented by shape and time to peak parameters. Weighted least-squares regression equations to estimate the two unit hydrograph parameters for ungaged watersheds are provided on the basis of the watershed characteristics of main channel length, dimensionless main channel slope, and a binary watershed development classification. The range of watershed area is approximately 0.32 to 167 square miles. The range of main channel length is approximately 1.2 to 49 miles. The range of dimensionless main channel slope is approximately 0.002 to 0.020. The equations provide a framework by which hydrologic engineers can estimate shape and time to peak of the unit hydrograph, and hence the associated peak discharge. Assessment of equation applicability and uncertainty for a given watershed also is provided. The authors explicitly do not identify a preferable approach and hence equations for unit hydrograph estimation. Each equation is associated with a specific analytical approach. Each approach represents the optimal unit hydrograph solution on the basis of the details of approach implementation including unit hydrograph model, unit hydrograph duration, objective functions, loss model assumptions, and other factors.Waller Creek Working Grou

Orchestration of Starbirth Activity in Disk Galaxies: New Perspectives from Ultraviolet Imaging

Ultraviolet imaging of nearby disk galaxies reveals the star-forming activity in these systems with unprecedented clarity. UV images recently obtained with the Shuttle-borne Ultraviolet Imaging Telescope (UIT) reveal a remarkable variety of star-forming morphologies. The respective roles of tides, waves, and resonances in orchestrating the observed patterns of starbirth activity are discussed in terms of the extant UV data.Comment: Paper format (latex); length of paper (4); 2 encapsulated postscript figure files; uses AIP Press files aipproc.cls, aipproc.sty; Journal Reference: to be published in proceedings in "Star Formation, Near and Far", Proceedings of the 7th annual Astrophysics Conference in Maryland, Steve Holt, Lee G. Mundy, editor