ABSTRACT
This article describes the design, characterization, and performance of an electrostatic glass actuator adapted to an ultrahigh vacuum environment (10(-8) mbar). The three-phase rotary motor is used to drive a turbine that acts as a velocity-selective light trap for a slow continuous beam of laser-cooled atoms. This simple, compact, and nonmagnetic device should find applications in the realm of time and frequency metrology, as well as in other areas of atomic, molecular physics and elsewhere.
Subject(s)
Glass , Lasers , Micromanipulation/instrumentation , Specimen Handling/instrumentation , Specimen Handling/methods , Cold Temperature , Equipment Design , Equipment Failure Analysis , Micromanipulation/methods , Reproducibility of Results , Rotation , Sensitivity and Specificity , Static Electricity , VacuumABSTRACT
We report on the primary frequency standard now under construction at the Observatoire de Neuchatel (ON). The design is based on a continuous fountain of laser-cooled cesium atoms, which combines two advantages: the negligible contribution of collisions to the inaccuracy and the absence of stability degradation caused by aliasing effects encountered in pulsed operation. The design is reviewed with special emphasis on the specific features of a continuous fountain, namely the source, the microwave cavity (TE(021) mode), and the microwave modulation scheme. The possible sources of frequency biases and their expected contributions to the error budget are discussed. Based on present data, an accuracy in the low 10(-15) range and a short-term stability of 7.10(-14) are attainable simultaneously under the same operating conditions.
ABSTRACT
HISTORY AND CLINICAL FINDINGS: A 39-year-old HIV positive patient developed myalgia, headache and cough 4 weeks after a tick bite. His temperature was 37.4 degrees C and a circular pale erythema was noted over the left lower leg. INVESTIGATIONS: C-reactive protein was raised to 120 mg/l, white blood cell count was 5860/microliter, CD4-lymphocyte count 250/microliter. The chest radiogram showed pneumonitic infiltration in the left lower lobe. There were IgM antibodies against Borrelia burgdorferi. TREATMENT AND COURSE: Left lower lobe pneumonia and chronic erythema migrans were diagnosed and he was given oral azithromycin (500 mg on the first day and 250 mg for 4 days). The pneumonia cleared up, but 2 weeks later he developed symptoms of meningitis (496 cells per microliter, 87% lymphocytes, positive Borrelia burgdorferi antibody titer), which quickly and lastingly responded to ceftriaxon (2 g daily by brief infusion for 14 days). CONCLUSION: This immune-compromised HIV-infected patient developed disseminated borreliosis with CNS involvement 2 weeks after the occurrence of chronic erythema migrans. The initial treatment of the latter with azithromycin was unable to prevent the meningitis. It is unlikely that there was a causal connection between the borreliosis and the pneumonia.
Subject(s)
HIV Seropositivity/complications , Lyme Disease/complications , Meningitis, Bacterial/etiology , Adult , Animals , Anti-Bacterial Agents/therapeutic use , Antibodies, Bacterial/blood , Azithromycin/therapeutic use , Borrelia burgdorferi Group , Ceftriaxone/therapeutic use , Cephalosporins/therapeutic use , Humans , Immunocompromised Host , Immunoglobulin M/blood , Insect Bites and Stings , Lyme Disease/diagnosis , Male , Meningitis, Bacterial/diagnosis , Meningitis, Bacterial/drug therapy , Pneumonia/drug therapy , Pneumonia/etiology , TicksABSTRACT
The question wheter in Switzerland, too, there exists an association between alcoholism and cirrhosis of the liver was examind by the use of Federal Statistics. E.M. Jellinek devised an internationally applicable formula which shows a linear relationship between these two conditions. Three hypotheses were tested to validate the assumption that there are no alternate causes of cirrhosis of the liver. The results show: a) that in Switzerland as elsewhere, a direct relationship exists only between alcoholism and cirrhosis of the liver; b) that, in consequence, other causes of the condition have only small significance; c) that mortality from cirrhosis shows a distinct sex difference, with a surprisingly great increase amongst women in recent years.