4,485 research outputs found

    VLA, PHOENIX, and BATSE observations of an X1 flare

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    We present observations of an X1 flare (18 Jul. 1991) detected simultaneously with the Very Large Array (VLA), the PHOENIX Digital Radio Spectrometer and the Burst and Transient Source Experiment (BATSE) aboard the Gamma Ray Observatory (GRO). The VLA was used to produce snapshot maps of the impulsive acceleration in the higher corona several minutes before the onset of the hard x ray burst detected by BATSE. Comparisons with high spectral and temporal observations by PHOENIX reveal a variety of radio bursts at 20 cm, such as type 3 bursts, intermediate drift bursts, and quasi-periodic pulsations during different stages of the X1 flare. From the drift rates of these radio bursts we derive information on local density scale heights, the speed of radio exciters, and the local magnetic field. Radio emission at 90 cm shows a type 4 burst moving outward with a constant velocity of 240 km/s. The described X1 flare is unique in the sense that it appeared at the east limb (N06/E88), providing the most accurate information on the vertical structure of different flare tracers visible in radio wavelengths

    \u3cem\u3eAFSCME v. Washington\u3c/em\u3e: The Death of Comparable Worth?

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    The Evolution of Clitics

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    Isolation of a Chloramphenicol-Resistant Protein From λ-Infected Cells

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    During infection with bacteriophage ϕX174, a protein, made in the presence of 30 γ chloramphenicol/ml but not made in the presence of concentrations greater than 100 γ/ml, has been shown to be essential for viral DNA replication. A protein with similar chromatographic properties and “chloramphenicol resistance” has now been demonstrated in cells infected with λ bacteriophage

    Ultrasound of the knee during voluntary quadriceps contraction: A technique for detecting otherwise occult effusions

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    Objective To describe 1) a technique that can detect synovial effusions not seen on static ultrasound (US) examination and 2) the characteristics of patients with knee osteoarthritis (OA) for whom this technique proved useful. Methods From reviewed records of 76 patients with knee OA (112 knees) that we had seen for US-guided injections over a defined period, we found 45 knees with no detectable effusion on static US, of which 18 (14 patients) showed fluid when scanned during voluntary quadriceps contraction. For all patients, we had recorded effusion features (physical examination, presence and size on US), and success of joint entry was determined by getting synovial fluid and/or seeing an air echo or inflow of injected material. Results The 14 patients we studied were obese (mean ± SEM body mass index 32.7 ± 2.3 kg/m 2 ; 3 morbidly obese), with moderate to severe OA by radiography in most (Kellgren/Lawrence class 3 or 4 in 10 of 14 knees for which radiographs were available). The suprapatellar synovial space seen by US was small (mean ± SEM depth 0.38 ± 0.04 cm). Arthrocentesis obtained 0.5–16 ml of synovial fluid (mean ± SEM 2.9 ± 0.6 ml), which correlated with the depth of effusion as seen on US with the quadriceps in maximum contraction (Spearman's Ρ = 0.5597, P = 0.0157). In 4 knees where arthrocentesis failed to retrieve fluid, we observed at injection the inflow of material and a linear air echo. Conclusion US of the knee during voluntary quadriceps contraction can find effusions not detectable on static US. Such effusions provide targets for accurate aspiration and injection that would not be appreciated with static US.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75770/1/20047_ftp.pd

    Angular two-photon interference and angular two-qubit states

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    Using angular-position-orbital-angular-momentum entangled photons, we study angular two-photon interference in a scheme in which entangled photons are made to pass through apertures in the form of double angular slits, and using this scheme, we demonstrate an entangled two-qubit state that is based on the angular-position correlations of entangled photons. The entanglement of the two-qubit state is quantified in terms of concurrence. These results provide an additional means for preparing entangled quantum states for use in quantum information protocols

    Caffeine Versus Methylphenidate and d-Amphetamine in Minimal Brain Dysfunction: A Double-Blind Comparison

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    The authors compared the efficacy of caffeine, methylphenidate, and d-amphetamine in children with minimal brain dysfunction using a double-blind crossover design. The slight improvement with caffeine was not significantly better than placebo. Both prescription drugs resulted in significant improvement and were significantly superior to caffeine. The authors suggest that the discrepancy between these results and an earlier, more optimistic report may stem from the use in this study of pure caffeine rather than whole coffee

    Optimisation of pooled faecal samples for the isolation fo Salmonella from finisher pigs in GB.

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    Pooled pen floor faecal sampling represents a simple and non-invasive method to measure Salmonella infection in pigs. We extended an existing model of the sensitivity of detection of Salmonella in individual samples to create a mathematical model of the sensitivity of pooled sampling
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