Placement shift, sibling relationship quality, and child outcomes in foster care: A controlled study.

Sibling unity during family transitions is considered a protective factor for child behavior problems, but there is little empirical support for the widespread child protection policy of placing siblings together in foster care. In a prospective study of 156 maltreated children, siblings were classified in 1 of 3 placement groups: continuously together (n = 110), continuously apart (n = 22), and disrupted placement (siblings placed together were separated; n = 24). Changes in child adjustment as a function of sibling relationship and placement group were examined. Sibling positivity predicted lower child problems at follow-up (about 14 months later), while sibling negativity predicted higher child problems. Placement group did not affect child behavior problems at follow-up; however, compared to siblings in continuous placement (either together or apart), siblings in disrupted placement with high initial behavior problems were rated as having fewer problems at follow-up, while siblings in disrupted placement with low initial behavior problems were rated as having more problems at follow-up. These findings highlight the importance of considering relationships between siblings and the risk that one poses to another before early placement decisions are made. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of semiconductor growth method and bulk doping on fermi level stabilization for aluminum and gold contacts on n- and p-GaAs(100)

Effects of substrate doping and growth method on interface deep level formation and Schottky barrier height were investigated using low-energy catho doluminescence and soft x-ray photoemission spectroscopy. Our results reveal that for Au/GaAs(100) contacts Fermi level (E_F) stabilization energy shows little sensitivity to either substrate growth technique or the type of doping, and Iles in the 0.37 to 0.47 eV range above the valence band maximum (E_v). In contrast, the E_F position at Al/GaAs(100) interfaces is highly sensitive to substrate growth method for n-type GaAs, but shows no significant difference between the epitaxial and melt-grown p-type GaAs. Furthermore, for a specific substrate dopant type and growth method, gold and aluminum produce barrier heights which differ by 0.05 to 0.50 eV, depending upon the substrate growth and dopant properties. Cathodoluminescence results demonstrate that discrete surface and interface states responsible for E_F stabilization at these metal/GaAs junctions are highly sensitive to the substrate growth technique, as well as to the specific metal contact. This work emphasizes that both substrate crystalline and electronic properties, as well as the adatom-specific interface chemistry are crucial for the electrostatic barrier height formation at metal/GaAs contacts.     

Spatial relationships between snow contaminant content, grain size, and surface temperature from multispectral images of Mt. Rainier, Washington (USA)

We use multispectral MODIS/ASTER Airborne Simulator (MASTER) data collected at Mt. Rainier, Washington (USA) to map spatial covariance between snowpack properties and to evaluate techniques for quantitative estimation of reflectance, grain size, and temperature. The late-August MASTER images reveal a distinct pattern of snow contaminant content, grain size, and temperature related to a recent snowfall and late-summer melting. Spatial correlation between grain size and temperature patterns suggests that rapid destructive metamorphism of the fresh snow occurred when temperatures were near 0 °C. We use 10 specific locations to evaluate hemispherical-directional reflectance factor (HDRF), grain size, and temperature retrievals. We map relative snow contaminant content using visible (0.4-0.8 μm) HDRF spectra. Atmospheric correction and topographic modeling limit the accuracy of HDRF estimates. We use MASTER-derived spectra near 1.8 and 2.2 μm to estimate optical grain size (by comparison to modeled layers of ice spheres) and physical grain size (by comparison to measured spectra with known physical grain size and by correlation to ground measurements). Estimated physical grain sizes were less than estimated optical grain sizes. Differing definitions of optical and physical grain sizes could contribute to this discrepancy. Limitations at 1.8 and 2.2 μm, including reduced discrimination between larger grain radii (>∼500 μm physical, >∼200 μm optical) and low signal-to-noise ration with atmospheric effects and decreasing solar irradiance, suggest that grain size retrieval may be improved at other wavelengths (e.g., 1.1 μm). Accounting for uncertainty in emissivity, atmospheric correction, and detector noise, we estimate systematic errors in our radiant temperatures at <1.8 °C. This study shows both strengths and limitations for coregistered visible, short-wave infrared, and thermal infrared images to estimate snowpack properties and reveal their spatial coherence.     

Trajectories of internalizing, externalizing, and grades for children who have and have not experienced their parents' divorce or separation.

This study examined whether the occurrence and timing of parental separation or divorce was related to trajectories of academic grades and mother- and teacher-reported internalizing and externalizing problems. The authors used hierarchical linear models to estimate trajectories for children who did and did not experience their parents' divorce or separation in kindergarten through 10th grade (N = 194). A novel approach to analyzing the timing of divorce/separation was adopted, and trajectories were estimated from 1 year prior to the divorce/separation to 3 years after the event. Results suggest that early parental divorce/separation is more negatively related to trajectories of internalizing and externalizing problems than is later divorce/separation, whereas later divorce/separation is more negatively related to grades. One implication of these findings is that children may benefit most from interventions focused on preventing internalizing and externalizing problems, whereas adolescents may benefit most from interventions focused on promoting academic achievement. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Cytosolic free calcium and the cytoskeleton in the control of leukocyte chemotaxis

In response to a chemotactic gradient, leukocytes extravasate and chemotax toward the site of pathogen invasion. Although fundamental in the control of many leukocyte functions, the role of cytosolic free Ca2+ in chemotaxis is unclear and has been the subject of debate. Before becoming motile, the cell assumes a polarized morphology, as a result of modulation of the cytoskeleton by G protein and kinase activation. This morphology may be reinforced during chemotaxis by the intracellular redistribution of Ca2+ stores, cytoskeletal constituents, and chemoattractant receptors. Restricted subcellular distributions of signaling molecules, such as Ca2+, Ca2+/calmodulin, diacylglycerol, and protein kinase C, may also play a role in some types of leukocyte. Chemotaxis is an essential function of most cells at some stage during their development, and a deeper understanding of the molecular signaling and structural components involved will enable rational design of therapeutic strategies in a wide variety of diseases.     

A resistive-gate In0.53Ga0.47As/InPheterostructure CCD

The first InGaAs/InP charge-coupled device (CCD) is demonstrated, exhibiting a charge transfer efficiency (CTE) of 0.98 at 13 MHz and 1 GHz. Cooling the device improves the CTE to greater than 0.99 at 13-MHz clock frequency. The 0.76-eV In_0.53Ga_0.47As bandgap makes this structure applicable to direct-detection short-wavelength infrared (SWIR) imagers     

Antineoplastic agents. 41. The beetle Allomyrina dichotomus

The belief that the smooth muscle contracting activity of angiotensin II (angiotensin) in the guinea pig ileum is partly mediated by release of acetylcholine was reexamined, with the following results. 1. Atropine did not reduce the maximum contraction produced by angiotensin, although it caused a shift to the right of the log dose-response curve (dose ratio = 2.2). A similar shift was observed with histamine, bradykinin and BaCl2. 2. A moderate potentiation of angiotensin by eserine was also observed, which was similarly found for the other agonists. 3. A previous report that atropine blocks the fast (phasic) component of the isometric response of the ileum to angiotensin was not confirmed. The disappearance of the phasic component was found to be due to a tachyphylactic change in the response. 4. Depolarization by high doses of nicotine, and inhibition of acetylcholine synthesis by hemicholinium, did not affect the response to angiotensin. 5. Ilei in which the intramural ganglia had been destroyed by incubation at 4 degrees 48-56 h responed maximally to angiotensin, without loss of the phasic component of the response. It is concluded that the available evidence does not support the participation of a cholinergic mechanism in the effect of angiotensin upon the guinea pig ileum.     

Decomposition of n- and iso-butyl acetates on charcoal

The decomposition of n-butyl acetate on charcoal was studied at 365° and 385°C, and isobutyl acetate at 394° and 419.5°C. Isobutene and acetic acid were the principal products from the iso ester, and n-butenes and acetic acid from the normal ester. Other primary and secondary reactions exceeded 20% in most experiments. The principal primary product from the normal ester was 1-butene which isomerized subsequently to 2-butenes; iso-butene from the iso ester did not isomerize. For both esters the activity of the charcoal decreased rapidly, the conversion decreasing linearly with time. Linear correlations were used to estimate the conversion at zero time, and data at zero time were used to evaluate constants of a rate equation. Fouling was attributed to reactions of olefins which produced carbonaceous residues.