265 research outputs found

    Planetary observations at millimeter wavelengths

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    Observations of the Sun, Moon, Mercury, Venus, Mars, Jupiter, and Saturn were made at 3.1 mm and 8.6 mm wavelengths with a 16-foot radio telescope between March and August, 1971. Absolute brightness temperature data are given. All errors are one standard deviation and include uncertainties in antenna gain calibration. The solar and lunar temperatures are in excellent agreement with published observations. The planetary measurements at 3.1 mm are consistently higher than previous results. The implications of higher temperatures with respect to existing atmospheric and surface models are discussed

    Removing Green Scum from Tanks and Reservoirs with Bluestone.

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    On the Antenna Beam Shape Reconstruction Using Planet Transit

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    The calibration of the in-flight antenna beam shape and possible beamdegradation is one of the most crucial tasks for the upcoming Planck mission. We examine several effects which could significantly influence the in-flight main beam calibration using planet transit: the problems of the variability of the Jupiter's flux, the antenna temperature and passing of the planets through the main beam. We estimate these effects on the antenna beam shape calibration and calculate the limits on the main beam and far sidelobe measurements, using observations of Jupiter and Saturn. We also discuss possible effects of degradation of the mirror surfaces and specify corresponding parameters which can help us to determine these effects.Comment: 10 pages, 8 figure

    An Absolute Flux Density Measurement of the Supernova Remnant Casseopia A at 32 GHz

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    We report 32 GHz absolute flux density measurements of the supernova remnant Cas A, with an accuracy of 2.5%. The measurements were made with the 1.5-meter telescope at the Owens Valley Radio Observatory. The antenna gain had been measured by NIST in May 1990 to be 0.505±0.007mKJy0.505 \pm 0.007 \frac{{\rm mK}}{{\rm Jy}}. Our observations of Cas A in May 1998 yield Scas,1998=194±5JyS_{cas,1998} = 194 \pm 5 {\rm Jy}. We also report absolute flux density measurements of 3C48, 3C147, 3C286, Jupiter, Saturn and Mars.Comment: 30 pages, 4 figures; accepted for publication by AJ. Revised systematic error budget, corrected typos, and added reference

    Broadband Meter-Wavelength Observations of Ionospheric Scintillation

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    Intensity scintillations of cosmic radio sources are used to study astrophysical plasmas like the ionosphere, the solar wind, and the interstellar medium. Normally these observations are relatively narrow band. With Low Frequency Array (LOFAR) technology at the Kilpisj\"arvi Atmospheric Imaging Receiver Array (KAIRA) station in northern Finland we have observed scintillations over a 3 octave bandwidth. ``Parabolic arcs'', which were discovered in interstellar scintillations of pulsars, can provide precise estimates of the distance and velocity of the scattering plasma. Here we report the first observations of such arcs in the ionosphere and the first broad-band observations of arcs anywhere, raising hopes that study of the phenomenon may similarly improve the analysis of ionospheric scintillations. These observations were made of the strong natural radio source Cygnus-A and covered the entire 30-250\,MHz band of KAIRA. Well-defined parabolic arcs were seen early in the observations, before transit, and disappeared after transit although scintillations continued to be obvious during the entire observation. We show that this can be attributed to the structure of Cygnus-A. Initial results from modeling these scintillation arcs are consistent with simultaneous ionospheric soundings taken with other instruments, and indicate that scattering is most likely to be associated more with the topside ionosphere than the F-region peak altitude. Further modeling and possible extension to interferometric observations, using international LOFAR stations, are discussed.Comment: 11 pages, 17 figure

    Intratracheal administration of endotoxin and cytokines: VIII. LPS induces E-selectin expression; anti-E-selectin and soluble E-selectin inhibit acute inflammation

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    E-selectin is an inducible endothelial adhesion molecule that binds neutrophils. E-selectin mRNA is not constitutively detectable in the lungs of rats. Intratracheal injection of LPS induces pulmonary E-selectin mRNA expression at 2–4 h. Intratracheal injection of LPS followed at 2 and 4 h by intravenous injection of mouse F(abâ€Č) 2 or F(abâ€Č)) anti-E-selectin monoclonal antibody inhibits the emigration of neutrophils into the bronchoalveolar space at 6 h by 50–70%. TNF and IL-6 bioactivity are not decreased in bronchoalveolar lavage fluid after treatment with anti-E-selectin antibody as compared to controls, suggesting that the anti-E-selectin does not affect the magnitude of the LPS-initiated cytokine cascade. Intratracheal injection of LPS followed at 2 and 4 h by intravenous injection of soluble E-selectin inhibits neutrophilic emigration at 6 h by 64%, suggesting that endogenous soluble E-selectin shed from activated endothelium may play a role in the endogenous down-regulation of acute inflammation. E-selectin-mediated adhesion of neutrophils to endothelium appears crucial to the full development of the acute inflammation response.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44513/1/10753_2005_Article_BF01534436.pd

    Downregulation of Mcl-1 has anti-inflammatory pro-resolution effects and enhances bacterial clearance from the lung

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    Phagocytes not only coordinate acute inflammation and host defense at mucosal sites, but also contribute to tissue damage. Respiratory infection causes a globally significant disease burden and frequently progresses to acute respiratory distress syndrome, a devastating inflammatory condition characterized by neutrophil recruitment and accumulation of protein-rich edema fluid causing impaired lung function. We hypothesized that targeting the intracellular protein myeloid cell leukemia 1 (Mcl-1) by a cyclin-dependent kinase inhibitor (AT7519) or a flavone (wogonin) would accelerate neutrophil apoptosis and resolution of established inflammation, but without detriment to bacterial clearance. Mcl-1 loss induced human neutrophil apoptosis, but did not induce macrophage apoptosis nor impair phagocytosis of apoptotic neutrophils. Neutrophil-dominant inflammation was modelled in mice by either endotoxin or bacteria (Escherichia coli). Downregulating inflammatory cell Mcl-1 had anti-inflammatory, pro-resolution effects, shortening the resolution interval (R(i)) from 19 to 7 h and improved organ dysfunction with enhanced alveolar–capillary barrier integrity. Conversely, attenuating drug-induced Mcl-1 downregulation inhibited neutrophil apoptosis and delayed resolution of endotoxin-mediated lung inflammation. Importantly, manipulating lung inflammatory cell Mcl-1 also accelerated resolution of bacterial infection (R(i); 50 to 16 h) concurrent with enhanced bacterial clearance. Therefore, manipulating inflammatory cell Mcl-1 accelerates inflammation resolution without detriment to host defense against bacteria, and represents a target for treating infection-associated inflammation

    Inhaled nitric oxide alleviates hyperoxia suppressed phosphatidylcholine synthesis in endotoxin-induced injury in mature rat lungs

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    BACKGROUND: We investigated efficacy of inhaled nitric oxide (NO) in modulation of metabolism of phosphatidylcholine (PC) of pulmonary surfactant and in anti-inflammatory mechanism of mature lungs with inflammatory injury. METHODS: Healthy adult rats were divided into a group of lung inflammation induced by i.v. lipopolysaccharides (LPS) or a normal control (C) for 24 h, and then exposed to: room air (Air), 95% oxygen (O), NO (20 parts per million, NO), both O and NO (ONO) as subgroups, whereas [(3)H]-choline was injected i.v. for incorporation into PC of the lungs which were processed subsequently at 10 min, 4, 8, 12 and 24 h, respectively, for measurement of PC synthesis and proinflammatory cytokine production. RESULTS: LPS-NO subgroup had the lowest level of labeled PC in total phospholipids and disaturated PC in bronchoalveolar lavage fluid and lung tissue (decreased by 46–59%), along with the lowest activity of cytidine triphosphate: phosphocholine cytidylyltransferase (-14–18%) in the lungs, compared to all other subgroups at 4 h (p < 0.01), but not at 8 and 12 h. After 24-h, all LPS-subgroups had lower labeled PC than the corresponding C-subgroups (p < 0.05). LPS-ONO had higher labeled PC in total phospholipids and disaturated PC, activity of cytidylyltransferase, and lower activity of nuclear transcription factor-ÎșB and expression of proinflammatory cytokine mRNA, than that in the LPS-O subgroup (p < 0.05). CONCLUSION: In LPS-induced lung inflammation in association with hyperoxia, depressed PC synthesis and enhanced proinflammatory cytokine production may be alleviated by iNO. NO alone only transiently suppressed the PC synthesis as a result of lower activity of cytidylyltransferase

    Educators' working conditions in a day care centre on ownership of a non-profit organization

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    Background: Working conditions of nursery school teachers have not been scrutinized thoroughly in scientific research. Only a few studies have so far examined work-load and strain in this profession. Preferably, subjective perceptions should be corroborated by data that can be quantified more objectively and accurately. The aim of the present observational field study was to evaluate pedagogical staffs' workflow. Methods: In 2009 eleven educators in a day care centre were observed throughout three complete workdays. A total of 250 working hours were recorded. Results: An educators' workday lasted on average 07:46:59 h (SD = 01:01:10 h).Within this time span, an average of 02:20:46 h (30.14%, SD = 00:28:07 h) were spent on caring, 01:44:18 h on playing (22.33%, SD = 00:54:12 h), 00:49:37 h on educational work (10.62%, SD = 00:40:09), and only 00:05:38 h on individual child contact (1.21%, SD = 00:04:58 h). Conclusion: For the first time, educators' workflow in day care centres was studied in real time. Some of the educators' self-reported problems were corroborated. The results of this study form a basis upon which further investigations can be built and measures can be developed for an overall improvement of child care

    Tests of sunspot number sequences: 1. Using ionosonde data

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    More than 70 years ago it was recognised that ionospheric F2-layer critical frequencies [foF2] had a strong relationship to sunspot number. Using historic datasets from the Slough and Washington ionosondes, we evaluate the best statistical fits of foF2 to sunspot numbers (at each Universal Time [UT] separately) in order to search for drifts and abrupt changes in the fit residuals over Solar Cycles 17-21. This test is carried out for the original composite of the Wolf/ZĂŒrich/International sunspot number [R], the new “backbone” group sunspot number [RBB] and the proposed “corrected sunspot number” [RC]. Polynomial fits are made both with and without allowance for the white-light facular area, which has been reported as being associated with cycle-to-cycle changes in the sunspot number - foF2 relationship. Over the interval studied here, R, RBB, and RC largely differ in their allowance for the “Waldmeier discontinuity” around 1945 (the correction factor for which for R, RBB and RC is, respectively, zero, effectively over 20 %, and explicitly 11.6 %). It is shown that for Solar Cycles 18-21, all three sunspot data sequences perform well, but that the fit residuals are lowest and most uniform for RBB. We here use foF2 for those UTs for which R, RBB, and RC all give correlations exceeding 0.99 for intervals both before and after the Waldmeier discontinuity. The error introduced by the Waldmeier discontinuity causes R to underestimate the fitted values based on the foF2 data for 1932-1945 but RBB overestimates them by almost the same factor, implying that the correction for the Waldmeier discontinuity inherent in RBB is too large by a factor of two. Fit residuals are smallest and most uniform for RC and the ionospheric data support the optimum discontinuity multiplicative correction factor derived from the independent Royal Greenwich Observatory (RGO) sunspot group data for the same interval
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