Mediators of telephone-based continuing care for alcohol and cocaine dependence.

A previous randomized trial with 224 alcohol and/or cocaine addicts who had completed an initial phase of treatment indicated that 12 weeks of telephone-based continuing care yielded higher abstinence rates over 24 months than did group counseling continuing care. The current study examined mediators of this treatment effect. Results suggested that self-help involvement during treatment and self-efficacy and commitment to abstinence 3 months after treatment mediated subsequent abstinence outcomes. These analyses controlled for substance use prior to the assessment of mediators. Conversely, there was no evidence that self-help beliefs or social support mediated the treatment effect. These results are consistent with a model in which treatment effects are first accounted for by changes in behavior, followed by changes in self-efficacy and in commitment to abstinence. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Active coke: Carbonaceous materials as catalysts for alkane dehydrogenation

The catalytic dehydrogenation (DH) and oxidative dehydrogenation (ODH) of light alkanes are of significant industrial importance. In this work both carbonaceous material deposited on VO_x/Al₂O₃ catalysts during reaction and unsupported carbon nanofibres (CNFs) are shown to be active for the dehydrogenation of butane in the absence of gas-phase oxygen. Their activity in these reactions is shown to be dependent upon their structure, with different reaction temperatures yielding structurally different coke deposits. Terahertz time-domain spectroscopy (THz-TDS), among other techniques, has been applied to the characterisation of these deposits – the first time this technique has been employed in coke studies. TEM and other techniques show that coke encapsulates the catalyst, preventing access to VO_x sites, without a loss of activity. Studies on CNFs confirm that carbonaceous materials act as catalysts in this reaction. Carbon-based catalysts represent an important new class of potential catalysts for DH and ODH reactions.     

Oxygen Deficiency and Hydrogen Turn ZnO Red

The effect of hydrogen on ZnO while annealing at 1370 K under oxygen-poor conditions with excess Zn vapor or Ti metal is studied. ZnO turns red only when hydrogen is present in a complex with oxygen vacancies. A practical method is described to remove hydrogen from ZnO in a sealed ampoule and to bind it to Ti metal. Hydrogen coupled to an oxygen vacancy is the simplest defect to explain the observations. The coloration is reversible at 1370 K by adding or removing hydrogen, consistent with an activation energy >1.5 eV. In red ZnO Hall data show a shallow donor level around 45 meV.     

Microfluidic arrays for bioimprint of cancer cells

We report the development and characterization of a microfluidics-based bioimprint process using high-density microchannel arrays for cell-culture and polymer delivery. The tubeless PDMS arrays consist of multiple independent microchannels and allow for parallelized bioimprint via automated dispensing and passive pumping. Using the microchannels, a 400 nm thin test pattern was replicated into a methacrylate biopolymer to demonstrate process applicability. Bioimprints of cobalt chloride stimulated Ishikawa endometrial cancer cells exhibiting exocytosis-like pore structures were compared with controls using AFM to exemplify a process application. The devices can be used for high-throughput cell assays, cell developmental studies and the formation of phenotype-specific biomimetic scaffolds.     

Microbial nitrogen dynamics in south central Chilean agricultural and forest ecosystems located on an Andisol

The natural soil N supply in volcanic soils (Andisols) can be a significant source of plant-available N for agro-ecosystems. Nevertheless, intensive farming systems in south Chile apply high fertilization rates, which lead to high production costs and involve a risk for adverse ecosystem effects. In order to achieve sustainable land management, a better understanding of the processes that govern soil N availability and loss, and their external drivers, is required. In this study, we selected a winter-cropland, a summer crop-winter fallow rotation, and a forest, used as a reference ecosystem. Gross N transformations (¹⁵N isotope dilution) and microbial community structure (phospho-lipid fatty acid analysis) in the topsoil were determined. Gross N mineralization was about ten times lower in the agro-ecosystems than in the forest, while gross nitrification was low in all sites. Gross N immobilization equalized or exceeded the gross inorganic N production in all sites. Microbial biomass was 3–5 times more abundant in the forest than in the agro-ecosystems. A positive relationship between the ratio fungi/bacteria and total microbial biomass was observed in these Andisols. We suggest that the reduction in fungal biomass induced a lower extracellular enzyme production and limited soil organic matter depolymerisation in the agro-ecosystems. We conclude that soil N cycling was unable to provide a significant N input for the croplands, but also the risk for ecosystem N losses was low, even under fallow soil conditions. Current fertilization practices appropriately anticipated the soil N cycling processes, but further research should indicate the potential of alternative land management to reduce fertilizer cost.     

Turning Social Relations into Space: Property,Law and the Plaza of Santa Fe,New Mexico

In this article, a series of controversies in and over the central Plaza of Santa Fe, New Mexico, USA is examined. The complex and contradictory dynamics of law and property as they intersect to shape and define a critical public space that is the symbolic heart of Santa Fe's landscape are explored. It is argued that laws and regulations that determine the activities that may occur in the Plaza, that restrict some actions, or that adjudicate ownership disputes literally shape the lands to which they pertain. It is shown that one purpose of law is to negotiate just how the social relations that are property get transformed into the regulated space that is property.     

Submicrometer Aerosol Mass Distributions of Emissions from Boilers,Fireplaces, Automobiles,Diesel Trucks,and Meat-Cooking Operations

The predominant peak in the mass distribution emitted from each source measured in this study occurs at or below about 0.2 μm in particle diameter, whereas the Los Angeles atmospheric aerosol contains peaks at a variety of sizes in the range between 0.1 and 1.0 μm in particle diameter, including peaks at sizes larger than 0.2 μm. This suggests that considerable modification of the primary aerosol size distribution occurs because of subsequent processes in the atmosphere. The data presented here are intended for use in defining the size distribution of the primary combustion source effluent for use with mathematical models of the evolution of the atmospheric aerosol size distribution.