Bromide-containing impurities were found to decrease the thermal stability of quaternary alkyl ammonium-modified layered silicates. Improved purification procedures completely removed bromide and led to a 20°C to >100°C increase in organic modified layered silicate thermal stability. Using mass spectrometry and thermal and electrochemical analysis, N,N-dimethyl-N,N-dioctadecyl quaternary ammonium-modified montmorillonite and fluorinated synthetic mica were found to degrade primarily through elimination and nucleophilic attack by these anions. The nature of residual bromides was identified and quantified, and the efficiency of removing these anions was found to be solvent dependent; sequential extraction, first ethanol then tetrahydrofuran, gave the best results. This exhaustive extraction method represents a viable alternative to the use of expensive, more thermally stable oniumion treatments for layered silicates.

Experiments were conducted in North Carolina during 2002 and 2003 to evaluate broadleaf signalgrass and large crabgrass control by clethodim and sethoxydim applied in two-, three-, or four-way mixtures with fungicides, insecticides, and foliar fertilizer–plant growth regulator treatments. Broadleaf signalgrass and large crabgrass control by clethodim and sethoxydim was not reduced by the insecticides esfenvalerate, indoxacarb, or lambda-cyhalothrin. The fungicides azoxystrobin, chlorothalonil, pyraclostrobin, and tebuconazole reduced large crabgrass control by clethodim or sethoxydim in one or more of three experiments for each herbicide. Disodium octaborate and the plant growth regulator prohexadione calcium plus urea ammonium nitrate (UAN) mixed with clethodim and fungicides improved large crabgrass control in some experiments. In contrast, prohexadione calcium plus UAN and disodium octaborate did not affect broadleaf signalgrass or large crabgrass control by sethoxydim.

Experiments were conducted in North Carolina during 2002 and 2003 to evaluate entireleaf morningglory control by 2,4-DB applied alone or with seven fungicides. In a separate group of experiments, tall morningglory control by 2,4-DB was evaluated when applied in four-way mixtures with the following: the fungicides azoxystrobin, chlorothalonil, pyraclostrobin, or tebuconazole; the insecticide lambda-cyhalothrin; and the foliar fertilizer disodium octaborate or the plant growth regulator (PGR) prohexadione calcium plus urea ammonium nitrate. Pyraclostrobin, but not azoxystrobin, boscalid, chlorothalonil, fluazinam, propiconazole plus trifloxystrobin, or tebuconazole, reduced entireleaf morningglory control by 2,4-DB. Mixtures of fungicides, insecticides, and foliar fertilizer/ PGR did not affect tall morningglory control by 2,4-DB. Placing artificial morningglory in the peanut canopy when fungicides were applied did not intercept enough fungicide to increase peanut defoliation by early leaf spot and web blotch or reduce pod yield compared with fungicide applied without artificial morningglory.

Digital signal processing is one of many valuable tools for suppressing unwanted signals or inter-ference. Building hardware processing engines seems to be the way to best implement some classes of interference suppression but is, unfortunately, expensive and time-consuming, especially if several miti-gation techniques need to be compared. Simulations can be useful, but are not a substitute for real data. CSIRO’s Australia Telescope National Facility has recently commenced a ‘software radio telescope’ project designed to fill the gap between dedicated hardware processors and pure simulation. In this approach, real telescope data are recorded coherently, then processed offline. This paper summarises the current contents of a freely available database of base band recorded data that can be used to experiment with signal processing solutions. It includes data from the following systems: single dish, multi-feed receiver; single dish with reference antenna; and an array of six 22 m antennas with and without a reference antenna. Astronomical sources such as OH masers, pulsars and continuum sources subject to interfering signals were recorded. The interfering signals include signals from the US Global Positioning System (GPS) and its Russian equivalent (GLONASS), television, microwave links, a low-Earth-orbit satellite, various other transmitters, and signals leaking from local telescope systems with fast clocks. The data are available on compact disk, allowing use in general purpose computers or as input to laboratory hardware prototypes.

Nutrigenomics is the study of how constituents of the diet interact with genes, and their products, to alter phenotype and, conversely, how genes and their products metabolise these constituents into nutrients, antinutrients, and bioactive compounds. Results from molecular and genetic epidemiological studies indicate that dietary unbalance can alter gene–nutrient interactions in ways that increase the risk of developing chronic disease. The interplay of human genetic variation and environmental factors will make identifying causative genes and nutrients a formidable, but not intractable, challenge. We provide specific recommendations for how to best meet this challenge and discuss the need for new methodologies and the use of comprehensive analyses of nutrient–genotype interactions involving large and diverse populations. The objective of the present paper is to stimulate discourse and collaboration among nutrigenomic researchers and stakeholders, a process that will lead to an increase in global health and wellness by reducing health disparities in developed and developing countries.

Dielectric properties of single walled carbon nanotube assemblies were calculated with an effective medium approximation at frequencies from 200 MHz to 200 GHz. The model treats the carbon nanotubes as layered cylinders, each with a core, a graphene layer and an outer layer, to investigate the dielectric properties of coated and filled nanotubes. The graphene and metal layer properties were modeled with a Drude approximation based on literature data. A generalized Bruggeman model was then used to determine the macroscopic behavior of the modified carbon nanotubes in a composite structure as a function of volume fraction, frequency, and aspect ratio. The depolarization factors in this model were scaled by the normalized effective permittivity to better account for percolation behavior. The model showed a wide variety of frequency dependent dielectric properties. Uncoated tubes were calculated to form highly conductive materials at volume fractions of just a few percent and metal-coated tubes enhanced the conductivity by an order of magnitude. Calculations of nanotubes with insulating coatings showed that high dielectric constants with moderate to low dielectric loss were possible.

Radiocarbon dates can provide an effective overview of regional trends in non-complex societies when treated in a quantitative manner. In spite of intervening biases, numbers of radiocarbon dates should reflect the patterns of occupation across time. Using the date record of preceramic Perú, I illustrate very different radiocarbon trends for highland and coastal zones. These suggest exponential growth, equilibrium, and altitude shift for the occupations of coastal, puna, and highland valley regions. Biases caused by variation in temporal and geographic investigation, and the effects of sea-level rise are considered, but I argue that general occupational patterns overshadow distortions of the date record.

Wheeler's review, while concentrating on key topics, uses inapplicable ecological data, misinterprets important issues, and makes incorrect statements about the book's contents.

Erosion can produce heterogeneous distributions of cultural materials of differing densities, weights, and shapes within an archaeological site. A large, provenienced surface collection from a preceramic site in highland Peru is examined for evidence of downslope movement as an explanation for observed heterogeneity in artifact distribution. Statistical methods of spatial analysis are used to define the extent of movements of surface materials in this site. For this particular area of Peru, critical angles for downslope movement will limit the site areas in which analysis of horizontal distributions can be expected to produce culturally significant information.