Many-body wave scattering by small bodies

Scattering problem by several bodies, small in comparison with the wavelength, is reduced to linear algebraic systems of equations, in contrast to the usual reduction to some integral equations

Optical Albedo Theory of Strongly-Irradiated Giant Planets: The Case of HD 209458b

We calculate a new suite of albedo models for close-in extrasolar giant planets and compare with the recent stringent upper limit for HD 209458b of Rowe et al. using MOST. We find that all models without scattering clouds are consistent with this optical limit. We explore the dependence on wavelength and waveband, metallicity, the degree of heat redistribution, and the possible presence of thermal inversions and find a rich diversity of behaviors. Measurements of transiting extrasolar giant planets (EGPs) at short wavelengths by MOST, Kepler, and CoRoT, as well as by proposed dedicated multi-band missions, can complement measurements in the near- and mid-IR using {\it Spitzer} and JWST. Collectively, such measurements can help determine metallicity, compositions, atmospheric temperatures, and the cause of thermal inversions (when they arise) for EGPs with a broad range of radii, masses, degrees of stellar insolation, and ages. With this paper, we reappraise and highlight the diagnostic potential of albedo measurements of hot EGPs shortward of $\sim$1.3 $\mu$m.Comment: 6 pages, 1 table, 1 color figure; accepted to the Astrophysical Journa

Distribution and kinematics of atomic and molecular gas inside the Solar circle

The detailed distribution and kinematics of the atomic and the CO-bright molecular hydrogen in the disc of the Milky Way inside the Solar circle are derived under the assumptions of axisymmetry and pure circular motions. We divide the Galactic disc into a series of rings, and assume that the gas in each ring is described by four parameters: its rotation velocity, velocity dispersion, midplane density and its scale height. We fit these parameters to the Galactic HI and CO (J=1-0) data by producing artificial HI and CO line-profiles and comparing them with the observations. Our approach allows us to fit all parameters to the data simultaneously without assuming a-priori a radial profile for one of the parameters. We present the distribution and kinematics of the HI and H2 in both the approaching (QIV) and the receding (QI) regions of the Galaxy. Our best-fit models reproduces remarkably well the observed HI and CO longitude-velocity diagrams up to a few degrees of distance from the midplane. With the exception of the innermost 2.5 kpc, QI and QIV show very similar kinematics. The rotation curves traced by the HI and H2 follow closely each other, flattening beyond R=6.5 kpc. Both the HI and the H2 surface densities show a) a deep depression at 0.5<R<2.5 kpc, analogous to that shown by some nearby barred galaxies, b) local overdensities that can be interpreted in terms of spiral arms or ring-like features in the disk. The HI (H2) properties are fairly constant in the region outside the depression, with typical velocity dispersion of 8.9+/-1.1 (4.4+/-1.2) km/s, density of 0.43+/-0.11 (0.42+/-0.22) cm-3 and HWHM scale height of 202+/-28 (64+/-12) pc. We also show that the HI opacity in the LAB data can be accounted for by using an `effective' spin temperature of about 150 K: assuming an optically thin regime leads to underestimate the HI mass by about 30%.Comment: 23 pages, 24 figures. Accepted by A&

Detection of fluorescence in situ hybridization on human metaphase chromosomes by near-field scanning optical microscopy

Fluorescence in situ hybridization signals o­n human metaphase chromosomes are detected by a near-field scanning optical microscope. This makes it possible to localize and identify several fluorescently labeled genomic DNA fragments o­n a single chromosome with a resolution superior to traditional fluorescence microscopy. Several nucleic acid probes have been used. The hybridization signals are well resolved in the near- field fluorescence images, and the exact location of the probes can be correlated to the topography as it is afforded by the shear-force feedback

Multi-detection and polarisation contrast in scannning near-field optical microscopy in reflection

A new type of NSOM probe has been developed, with a design based o­n the probes used in Atomic Force Microscopy. The probe consists of a cantilever with at its end a conical tip. This tip has been metal-coated to provide an aperture. With the cantilevered probe, the problem of breaking of the tip due to high normal forces is solved. In operation, the tip is scanned in contact with the sample while regulating the force between the tip and the sample with a beam deflection technique, which allows to simultaneously make an optical and a topographical image of the sample. The probes are made using micromechanical techniques, which allows batch fabrication of the probes. Testing of the probes is done in a transmission NSOM set-up in which the sample is scanned while the tip and the optical path are kept fixed. Using an opaque sample with submicron holes, the new probes have been tested, resulting an optical image with a simultaneously measured topographical image

The Westerbork HI Survey of Spiral and Irregular Galaxies I. HI Imaging of Late-type Dwarf Galaxies

Neutral hydrogen observations with the Westerbork Synthesis Radio Telescope are presented for a sample of 73 late-type dwarf galaxies. These observations are part of the WHISP project (Westerbork HI Survey of Spiral and Irregular Galaxies). Here we present HI maps, velocity fields, global profiles and radial surface density profiles of HI, as well as HI masses, HI radii and line widths. For the late-type galaxies in our sample, we find that the ratio of HI extent to optical diameter, defined as 6.4 disk scale lengths, is on average 1.8+-0.8, similar to that seen in spiral galaxies. Most of the dwarf galaxies in this sample are rich in HI, with a typical M_HI/L_B of 1.5. The relative HI content M_HI/L_R increases towards fainter absolute magnitudes and towards fainter surface brightnesses. Dwarf galaxies with lower average HI column densities also have lower average optical surface brightnesses. We find that lopsidedness is as common among dwarf galaxies as it is in spiral galaxies. About half of the dwarf galaxies in our sample have asymmetric global profiles, a third has a lopsided HI distribution, and about half shows signs of kinematic lopsidedness.Comment: Accepted for publication in A&A. 18 pages. 39 MB version with all figures is available http://www.robswork.net/publications/WHISPI.ps.g

Chemically driven switches for online detection of pH changes in microfluidic devices

The internal walls of microfabricated fluidic channels were functionalized with a selfassembled monolayer of Rhodamine B lactam. This molecule has the capability to interconvert between its open fluorescent amide form and the closed non-fluorescent lactam form upon changes of the pH conditions. The interconversion (switch) between the two reversible forms is achieved by addition of an acid or a base and is consistent with a reaction mechanism of the first order. This paper describes the online observation of such fluorescent switch covalently anchored to the channel and proposes this method as a possible sensor for the monitoring of pH changes in microreactors

Особливості емоційного вигорання педагогів із різним стажем роботи

зв'язку з великою емоційною напруженістю професійної діяльності педагога, нестандартністю педагогічних ситуацій, відповідальністю і складністю професійної праці вчителя, збільшується ризик розвитку синдрому «емоційного вигорання». При цьому дуже мало звертається уваги на діючі ефективні психолого- педагогічні та медичні технології, які спрямовані на збереження здоров'я педагога, що знижують ризик формування синдрому «емоційного вигорання» і появи кризи професії в цілому