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Simultaneous Observations (simultaneous + observation)
Selected AbstractsRadiative transfer validation study from the European Aqua Thermodynamic ExperimentTHE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 639 2009Stuart M. Newman Abstract The European AQUA Thermodynamic Experiment (EAQUATE) brought together collocated hyperspectral measurements from the Atmospheric Infrared Sounder (AIRS) on NASA's Aqua satellite, as well as three airborne interferometers operating in the troposphere and stratosphere. Simultaneous observations of temperature, water vapour and trace gases have been used to constrain the atmospheric state, for validation of radiometric accuracy and radiative transfer modelling. The close agreement of observations with model spectra, in the 800,1200 cm,1 region, indicates that the accuracy of modelling AIRS spectra is sufficient for beneficial use of the data in operational weather forecasting. The variability of atmospheric water vapour was found to be a fundamental constraint in the modelling of the 1400,1600 cm,1 region, emphasising the requirement for a high density of observations in future validation campaigns. Copyright © Royal Meteorological Society and Crown Copyright, 2009. [source] Mechanical Response Analysis and Power Generation by Single-Cell StretchingCHEMPHYSCHEM, Issue 4 2005Alexandre Micoulet Dr. Abstract To harvest useful information about cell response due to mechanical perturbations under physiological conditions, a cantilever-based technique was designed, which allowed precise application of arbitrary forces or deformation histories on a single cell in vitro. Essential requirements for these investigations are a mechanism for applying an automated cell force and an induced-deformation detection system based on fiber-optical force sensing and closed loop control. The required mechanical stability of the setup can persist for several hours since mechanical drifts due to thermal gradients can be eliminated sufficiently (these gradients are caused by local heating of the cell observation chamber to 37,°C). During mechanical characterization, the cell is visualized with an optical microscope, which enables the simultaneous observation of cell shape and intracellular morphological changes. Either the cell elongation is observed as a reaction against a constant load or the cell force is measured as a response to constant deformation. Passive viscoelastic deformation and active cell response can be discriminated. The active power generated during contraction is in the range of Pmax=10,16Watts, which corresponds to 2500 ATP molecules,s,1at 10 kBT/molecule. The ratio of contractive to dissipative power is estimated to be in the range of 10,2. The highest forces supported by the cell suggest that about 104molecular motors must be involved in contraction. This indicates an energy-conversion efficiency of approximately 0.5. Our findings propose that, in addition to the recruitment of cell-contractile elements upon mechanical stimulation, the cell cytoskeleton becomes increasingly crosslinked in response to a mechanical pull. Quantitative stress,strain data, such as those presented here, may be employed to test physical models that describe cellular responses to mechanical stimuli. [source] Early oral behaviour in preterm infants during breastfeeding: an electromyographic studyACTA PAEDIATRICA, Issue 6 2001K Hedberg Nyqvist The objectives were to increase the understanding of the characteristics of oral behaviour during breastfeeding in preterm infants and to validate direct observations of infant sucking. Twenty-six infants were investigated once by simultaneous observation and surface electromyography (EMG) at 32.1,37.1 postmenstrual weeks. The orbicularis oris muscle was used for data analysis, as it provided the most distinct registrations. High correlation coefficients were observed with respect to classifications of EMG data by two raters on the number of sucks per burst (r= 0.97) and duration of sucking bursts (r= 0.99). The agreement between direct observations of sucking and EMG data was high. The median for mean number of sucks per burst was 8 (range 2,33) and for longest burst 28 (5,96) sucks. Sucks with low and very high intensity constituted a median of 14 (1,94)% and 25 (0,87)% of all sucks. The range in mean sucking frequency was 1.0,1.8 sucks s- 1. Suck duration ranged from 0.6 to 1.1 s. There was a considerable variation between infants in the extent of mouthing. No association with maturational level appeared for any of the components in oral behaviour. Conclusion: EMG data provided evidence of early sucking competence in preterm infants during breastfeeding, with wide individual variations. Surface EMG and direct observation are recommended as valid methods in the evaluation of breastfeeding behaviour in preterm infants. [source] UBVRI observations of the flickering of RS Ophiuchi at quiescence,MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2010R. K. Zamanov ABSTRACT We report observations of the flickering variability of the recurrent nova RS Oph at quiescence on the basis of simultaneous observations in five bands (UBVRI). RS Oph has a flickering source with (U,B)0=,0.62 ± 0.07, (B,V)0= 0.15 ± 0.10 and (V,R)0= 0.25 ± 0.05. We find for the flickering source a temperature Tfl, 9500 ± 500 K, and luminosity Lfl, 50,150 L, (using a distance of d= 1.6 kpc). We also find that on a (U,B) versus (B,V) diagram, the flickering of the symbiotic stars differs from that of the cataclysmic variables. The possible source of the flickering is discussed. The data are available upon request from the authors. [source] VSOP polarization observations of the BL Lacertae object OJ 287MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2001D. C. Gabuzda VLBI total intensity and linear polarization images of the BL Lacertae object OJ 287 have been obtained at using a global ground array and the HALCA orbiting antenna, and at two weeks earlier using the VLBA. In the ground-based 6-cm images, the source is dominated by a core,jet double structure the components of which are essentially unresolved. The baselines to the orbiting antenna resolve both of these compact components. In the VSOP images, the ground-based ,core' breaks up into several distinct components, demonstrating that this region is dominated by the contribution of bright, optically thin knots of jet emission. A very similar structure is observed in the 1.3-cm image. The magnetic field in the core is transverse, becomes longitudinal in the inner jet, then makes a sharp transition to a region of transverse field further from the core. This suggests that the field in the outer jet has become highly ordered in the transverse direction owing to the action of a shock; the physical nature of the extended region of longitudinal field closer to the core is not clear. The availability of nearly simultaneous observations with comparable resolution at widely spaced frequencies enabled detection of a ,90° rotation in polarization position angle for the core, owing to the transition from the optically thick (6 cm) to the optically thin (1.3 cm) regime. [source] High frequency GPS sources in the AT20G surveyASTRONOMISCHE NACHRICHTEN, Issue 2-3 2009P.J. Hancock Abstract The Australia Telescope 20 GHz (AT20G) survey was used to select a complete sample of 656 Gigahertz Peaked Spectrum (GPS) sources with spectral turnovers above 5 GHz. The AT20G has near simultaneous observations at 4.8, 8.6 and 20 GHz, which makes it possible to exclude flat spectrum variability as a cause of a source's peaked spectrum. Optical identification of the sample results in 361 QSOs and 104 galaxies and 191 blank fields. Redshifts are known for 104 of the GPS sources. The GPS sources from the AT20G are discussed and compared to previously known samples. The new sample of high frequency peaking GPS sources is found at a lower redshift than previous samples and to also have a lower 5 GHz radio power. Evidence is found to support the idea that the origin of the GPS spectral shape are intrinsically different for galaxies and QSOs. This paper is an elaboration and extension of the talk given at the 4th CSS/GPS conference in Riccione in May this year (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | ||||||||||