5,534 research outputs found

    The galaxy's 157 micron (C 2) emission: Observations by means of a spectroscopic lunar-occultation technique

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    Galactic (C II) 157 micron, fine-structure emission was estimated. At a Galactic longitude of 8 deg, the peak power observed in a 7' x 7' field is approx. 5 x 10 to the -9 Watt. The method used to detect this radiation involved chopping against the cold side of the Moon

    Highly ejected J = 16 to 15 rotational transitions of CO at 162.8 mirons in the Orion cloud

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    The first observations of the J = 16 to J = 15, 162.8 microns transition of CO from an astronomical source are reported. Measurements were carried out on the Kleinmann-Low Nebula. The intensity observed is in good agreement with predictions from previous spectroscopic work carried out in the far infrared. The observation strengthens the previous claim that approximately 1.5 solar mass of molecular hydrogen is heated to a temperature above 750 K within the shocked region in the Nebula. Upper limits to he OH intensity in the F2 (2Pi 1/2) transitions J = 3/2 to J = 1/2 which fall into two groups centered respectively at 163.12 and 163.40 are presented

    Observations of the 145.5 micron (OI) emission line in the Orion nebula

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    A first set of observations of the (OI) 3P to 3P1 (145.5 micron) transition was obtained. The line was observed both in a beam centered on the Trapezium, and in a 7 times wider beam encompassing most of the Orion Nebula. A wide beam map of the region was constructed which shows that most of the emission is confined to the central regions of the nebula. These observations may be compared with reported measurement of the 3P1 to 3P2 (63.2 micron) transition in Orion and are consistent with optically thin emission in the 145.5 micron line and self-adsorbed 63.2 micron emission lines. Mechanisms are discussed for the excitation of neutral oxygen. It is included that much of the observed emission originates in the thin, radio-recombination-line-emitting CII/HI envelope bordering on the HII region

    The Gravitomagnetic Influence on Gyroscopes and on the Lunar Orbit

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    Gravitomagnetism--a motional coupling of matter analogous to the Lorentz force in electromagnetism--has observable consequences for any scenario involving differing mass currents. Examples include gyroscopes located near a rotating massive body, and the interaction of two orbiting bodies. In the former case, the resulting precession of the gyroscope is often called ``frame dragging,'' and is the principal measurement sought by the Gravity Probe-B experiment. The latter case is realized in the earth-moon system, and the effect has in fact been confirmed via lunar laser ranging (LLR) to approximately 0.1% accuracy--better than the anticipated accuracy of the Gravity-Probe-B result. This paper shows the connnection between these seemingly disparate phenomena by employing the same gravitomagnetic term in the equation of motion to obtain both gyroscopic precession and modification of the lunar orbit. Since lunar ranging currently provides a part in a thousand fit to the gravitomagnetic contributions to the lunar orbit, this feature of post-Newtonian gravity is not adjustable to fit any anomalous result beyond the 0.1% level from Gravity Probe-B without disturbing the existing fit of theory to the 36 years of LLR data.Comment: 4 pages; accepted for publication in Physical Review Letter

    A microfabricated ion trap with integrated microwave circuitry

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    We describe the design, fabrication and testing of a surface-electrode ion trap, which incorporates microwave waveguides, resonators and coupling elements for the manipulation of trapped ion qubits using near-field microwaves. The trap is optimised to give a large microwave field gradient to allow state-dependent manipulation of the ions' motional degrees of freedom, the key to multiqubit entanglement. The microwave field near the centre of the trap is characterised by driving hyperfine transitions in a single laser-cooled 43Ca+ ion.Comment: 4 pages, 5 figure

    High-fidelity preparation, gates, memory and readout of a trapped-ion quantum bit

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    We implement all single-qubit operations with fidelities significantly above the minimum threshold required for fault-tolerant quantum computing, using a trapped-ion qubit stored in hyperfine "atomic clock" states of 43^{43}Ca+^+. We measure a combined qubit state preparation and single-shot readout fidelity of 99.93%, a memory coherence time of T2∗=50T^*_2=50 seconds, and an average single-qubit gate fidelity of 99.9999%. These results are achieved in a room-temperature microfabricated surface trap, without the use of magnetic field shielding or dynamic decoupling techniques to overcome technical noise.Comment: Supplementary Information included. 6 nines, 7 figures, 8 page

    Adipose Tissue Distribution and Survival Among Women with Nonmetastatic Breast Cancer.

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    ObjectivePrevious studies of breast cancer survival have not considered specific depots of adipose tissue such as subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT).MethodsThis study assessed these relationships among 3,235 women with stage II and III breast cancer diagnosed between 2005 and 2013 at Kaiser Permanente Northern California and between 2000 and 2012 at Dana Farber Cancer Institute. SAT and VAT areas (in centimeters squared) were calculated from routine computed tomography scans within 6 (median: 1.2) months of diagnosis, covariates were collected from electronic health records, and vital status was assessed by death records. Hazard ratios (HRs) and 95% CIs were estimated using Cox regression.ResultsSAT and VAT ranged from 19.0 to 891 cm2 and from 0.484 to 454 cm2 , respectively. SAT was related to increased risk of death (127-cm2 increase; HR [95% CI]: 1.13 [1.02-1.26]), but no relationship was found with VAT (78.18-cm2 increase; HR [95% CI]: 1.02 [0.91-1.14]). An association with VAT was noted among women with stage II cancer (stage II: HR: 1.17 [95% CI: 0.99-1.39]; stage III: HR: 0.90 [95% CI: 0.76-1.07]; P interaction < 0.01). Joint increases in SAT and VAT were associated with mortality above either alone (simultaneous 1-SD increase: HR 1.19 [95% CI: 1.05-1.34]).ConclusionsSAT may be an underappreciated risk factor for breast cancer-related death
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