Inclusion characterization in a scattering slab with time-resolved transmittance measurements: perturbation analysis

A procedure for the time-domain optical characterization of an inclusion in a scattering slab is investigated theoretically and experimentally. The method relies on the measurement of a contrast function, which is defined as the time-dependent relative change in the transmitted signal resulting from the presence of the inclusion. Analytical expressions for the contrast functions of absorptive and diffusive inclusions are obtained through a perturbation solution of the diffusion equation. This procedure is used successfully to determine the optical properties of absorptive, diffusive, and mixed inclusions located at midplane in a scattering slab by use of time-resolved transmittance measurements.     

Modeling Respiration of Apple Slices in Modified-Atmosphere Packages

Modified-atmosphere packaging was used to provide respiratory data for apple (Malus xdomestica Borkh.) slices at 0, 5, 10 and 15°C. The maximum rate of O₂ uptake increased with increasing temperature. The lowest O₂ partial pressure to which fruit could be exposed without fermentation also increased with increasing temperature. A mathematical model of film permeability data characterized the effect of fruit mass, film permeability to O₂, activation energy of O₂ permeation, temperature, and the film type, area, and thickness on O₂ partial pressure for hermetically packaged apple slices. The model identified a minimum (fruit mass filmthickness)/(film area) ratio for apple slices, which would simplify package design calculations.     

Indium tin oxide nanowhisker morphology control by vapour-liquid-solid glancing angle deposition

A new growth technique for indium tin oxide nanowhiskers with increased control over feature size and spacing is reported. The technique is based on a unique combination of self-catalysed vapour-liquid-solid (VLS) growth and glancing angle deposition (GLAD). This VLS-GLAD technique provides enhanced control over nanowhisker morphology as the effect of typical VLS growth parameters (e.g.?flux rate, temperature) is amplified at large deposition angles characteristic of GLAD. Spatial modulation of the collimated growth flux controls trunk width, number and orientation of branches, and overall nanowhisker density. Here we report the influence of growth conditions (including deposition angle, flux rate, nominal pitch and substrate temperature) on nanowhisker morphology, with specific focus on the effect of large deposition angles. Sheet resistance and transmission of the films were measured to characterize their performance as transparent conductive oxides. Hybrid nanostructured films grown in this study include high surface area nanowhiskers protruding from a conductive film, ideal for transparent conductive electrode applications.     

Characterization of indolidan- and rolipram-sensitive cyclic nucleotide phosphodiesterases in canine and human cardiac microsomal fractions

The distribution of phosphodiesterase (PDE) activities was studied in canine cardiac microsomal fractions separated by sucrose density gradient (fractions F1 to Fv1). These fractions were characterized by their 45Ca2+ uptake and release properties, [3H] ryanodine binding [used as sarcoplasmic reticulum (SR) markers] and their [3H]nitrendipine binding (as a T-system marker). The solubilized canine and human SR-enriched membranes were subjected to high performance liquid chromatography and the PDE forms were then analyzed for their kinetic properties and drug sensitivies. In human SR, a notable amount of PDE I hydrolyzing both cAMP and cGMP was characterized; however, its stimulation by calmodulin was reduced. Two selective cAMP-PDE forms were identified in the canine and human cardiac SR-enriched fractions. The major form presents the characteristics of PDE III: an apparent Km value of 0.29 and 0.35 microM in canine and human cardiac SR, respectively, potent inhibition by cGMP and AAL 05 > cilostamide > Cl 930 > indolidan, and insensitivity to rolipram. The other form displays the properties of PDE IV: an apparent Km value of 1.4 and 1.3 microM in canine and human cardiac SR respectively, potent inhibition by rolipram and poorly sensitive to inhibition by PDE III inhibitors. The PDE IV distribution in canine SR suggests that this form is mostly associated with the FII fraction enriched in sarcolemmal membranes. In contrast, PDE III assessed by its indolidan sensitivity and [3H]LY186126 binding is associated with the microsomal membranes enriched in vesicles derived from T-tubule and junctional SR membranes. Because these membranes are directly involved in controlling excitation-contraction coupling, such PDE location enhances the physiologic relevance to study their implication in regulating cardiac contraction.     

Superconductivity in the presence of short-range magnetic order

Superconducting critical field curves have been measured for La₉₈Lu_2–xTb_x alloys in a regime where the Tb ions show short-range magnetic order. The concentration dependence of the superconducting transition temperature and the critical field curves both show large deviations from the simple multiple pair-breaking theories and indicate the presence of substantial exchange fields. The onset of short-range order is very detrimental to superconductivity in this system.     

Conduites abusives et négligentes envers les enfants: Réalités canadienne et américaine.

Conducted 2 studies in Montreal on the correlation between economic and social poverty of neighborhoods and the incidence rate of family violence and neglect against children. In the 1st study, an incidence rate of 4.95 per 1,000 families was computed. The best predictors of child maltreatment were the percentage of families under the poverty level in a given area and the percentage of families in which the woman was the only breadwinner. A 2nd study was conducted among 291 mothers living in equally poor neighborhoods that dramatically differed in their rates of child abuse and neglect. Mothers of high-rate neighborhoods described more centripetal, conflictual, and specialized social support networks than mothers of low-rate areas. Results confirm the strong association between economic deprivation and family suffering and underline the important role played by psychosocial, political, and cultural factors in parent–child relationships. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)