Social Support Networks Among Children with Intellectual and Developmental Disabilities

Previous research using predominantly adult populations has found that social support is positively correlated with an individual’s quality of overall health and wellbeing. Given the limited research investigating social support among children, especially children with special needs, the present study explored the social support networks of children with intellectual and developmental disabilities (IDD). Nine children enrolled in an after-school program were observed interacting with others and were interviewed in group discussions about the sources of support they tend to rely on in their daily activities. Preliminary findings suggest that children relied on each other’s for help during the regular after-school activities and reported receiving different extent and types of support from family members, peers, teachers, and coaches. These findings suggest that children with IDD benefit from a strong social support network system which may have practical implications for middle childhood interventions in educational settings

QCD at LEP 2 and WW Final State Interactions

A short overview of the QCD program at LEP~2 is given. Studies of final state interactions in e+e- -> WW -> qqqq decays are discussed.Comment: 6 pages, 2 figures, to be published in the proceedings of the 34th Rencontres de Moriond, Les Arrcs 1800, France, 13-20 March 199

Photometric and other laboratory studies relating to the lunar surface

Photometric measurements of light intensity from variety of surfaces to determine lunar surface light scattering characteristic

Bidirectional reflectance spectroscopy

An analytical model is developed for the opposition effects (heiligenshein) in the case of light scattering from a semi-infinite, particulate medium with particles that are large relative to the wavelength. The effect is common for natural materials, and comprises a bright surge in light diffusively reflected from a surface at near zero phase. A generalized expression is devised for the extinction coefficient of a particulate medium. Models are developed for step function and hyperbolic tangent distributions of light scattered from a stratified medium and exhibiting the opposition effect. A maximum brightness amplitude increase of 0.753 is projected for the effect. Greater values must have other causes. To illustrate the theory it is fitted to observations of the Moon, an asteroid, and a satellite of Uranus; Europa is also discussed

Venus Clouds: A dirty hydrochloric acid model

The spectral and polarization data for Venus are consistent with micron-sized, aerosol cloud particles of hydrochloric acid containing soluble and insoluble iron compounds, whose source could be volcanic or crustal dust. The ultraviolet features could arise from variations in the Fe-HCl concentration in the cloud particles

On the sputter alteration of regoliths of outer solar system bodies

Several processes that are expected to occur when the porous regoliths of outer solar system bodies (without atmospheres) are subjected to energetic ion bombardment are discussed. The conclusions reached in much of the literature addressing sputtering are quantitatively or qualitatively incorrect because effects of soil porosity have been neglected. It is shown theoretically and experimentally that porosity reduces the effective sputtering yield of a soil by more than an order of magnitude. Between 90 and 97% of the sputtered atoms are trapped within the regolith, where they are factionated by differential desorption. Experiments indicate that more volatile species have higher desorption probabilities. This process is the most important way in which alteration of chemical and optical properties occurs when a regolith is sputtered. When a basic silicate soil is irradiated these effects lead to sputter-deposited films enriched in metallic iron, while O, Na and K are preferentially lost. The Na and K are present in the atmosphere above the sputtered silicate in quantities much greater than their abundances in the regolith. Icy regoliths of SO2 should be enriched in elemental S and/or S2O. This prediction is supported by the probable identification of S2O and polysulfur oxide bands in the IR spectra of H-sputtered SO2 reported by Moore. When porous mixtures of water, ammonia and methane frosts are sputtered, the loss of H and surface reactions of C, N and O in the deposits should produce complex hydrocarbons and carbohydrates, some of which may be quite dark. Such reactions may have played a role in the formation of the matrix material of carbonaceous chondrites prior to agglomeration

A preliminary analysis of the Mariner 10 color ratio map of Mercury

A preliminary geological analysis of the Mariner 10 orange/UV color ratio map of Mercury is given, assuming a basaltic crust. Certain errors in the map are pointed out. The relationship between color and terrain are distinctly non-lunar. Rays and ejecta are bluer than average on Mercury, whereas they are redder on the Moon. This fact, along with the lack of the ferrous band in Mercury's spectral reflectance and smaller albedo contrasts, implies that the crust is low in Fe and Ti. There is no correlation between color boundaries and the smooth plains on Mercury, in contrast with the strong correlation between color and maria-highlands contacts on the Moon. The smooth plains are not Mercurian analogs of lunar maria, and a lunar-type of second wave melting did not occur. Ambiguous correlations between color and topography indicate that older, redder materials underlie younger, bluer rocks in many places on the planet, implying that the last stages of volcanism involved low-Fe lavas covering higher-Fe rocks. There is some evidence of late Fe-rich pyroclastic activity

Deformation of polymer films by bending forces

We study the deformation of nano--scale polymer films which are subject to external bending forces by means of computer simulation. The polymer is represented by a generalized bead--spring--model, intended to reproduce characteristic features of n--alkanes. The film is loaded by the action of a prismatic blade which is pressed into the polymer bulk from above and a pair of columns which support the film from below. The interaction between blade and support columns and the polymer is modelled by the repulsive part of a Lennard-Jones potential. For different system sizes as well as for different chainlengths, this nano--scale experiment is simulated by molecular dynamics methods. Our results allow us to give a first characterization of deformed states for such films. We resolve the kinetic and the dynamic stage of the deformation process in time and access the length scale between discrete particle and continuum mechanics behaviour. For the chainlengths considered here, we find that the deformation process is dominated by shear. We observe strangling effects for the film and deformation fluctuations in the steady state.Comment: 15 pages, 8 figure

Atlas of reflectance spectra of terrestrial, lunar and meteoritic powders and frosts from 92 to 1800 nm

The reflectance spectra of powdered samples of selected minerals, meteorites, lunar materials and frosts are presented as an aid in the interpretation of present and future remote sensing data of solar system objects. Spectra obtained in separate wavelength regions have been combined and normalized, yielding coverage from 92 to 1800 nm. Spectral features include reflectance maxima in the far UV region produced by valence-conduction interband transitions, and reflectance minima in the near UV, visible and near IR regions, produced by charge transfer and crystal field transitions. Specific maxima and minima are diagnostic of mineral type and composition; additionally, the minerals present in mixtures such as meteorites and lunar samples can be determined

Are Planetary Regolith Particles Back Scattering? Response to a Paper by M. Mishchenko

In a recent paper Mishchenko asserts that soil particles are strongly forward scattering, whereas particles on the surfaces of objects in the solar system have been inferred to be back scattering. Mishchenko suggests that this apparent discrepancy is an artifact caused by using an approximate light scattering model to analyse the data, and that planetary regolith particles are actually strong forward scatterers. The purpose of the present paper is to point out the errors in Mishchenko's paper and to show from both theoretical arguments and experimental data that inhomogencous composite particles which are large compared to the wavelength of visible light, such as rock fragments and agglutinates, can be strongly back scattering and are the fundamental scatterers in media composed of them. Such particles appear to be abundant in planetary regoliths and can account for the back scattering character of the surfaces of many bodies in the solar system. If the range of phase angles covered by a data set is insufficient, serious errors in retrieving the particle scattering properties can result whether an exact or approximate scattering model is used. However, if the data set includes both large and small phase angles, approximate regolith scattering models can correctly retrieve the sign of the particle scattering asymmetry