AN EVALUATION OF CONSUMER PESTICIDE RESIDUE CONCERNS AND RISK INFORMATION SOURCES

Marginal probability effects of demographic variables on consumer concerns about pesticide residues were assessed as well as the likelihood of consumer beliefs given different channels of information on produce safety and risks. This was done using maximum likelihood estimation (MLE) of ordered logit models. The empirical results showed that pesticide residue concern levels appeared to be lower for more highly educated and high income households. Safety information from the academic community was found to have the highest likelihood of acceptance by consumers.Risk and Uncertainty,

Dellafossite CuAlO2 film growth and conversion to Cu–Al2O3 metal ceramic composite via control of annealing atmospheres

In this work we demonstrate simple techniques to form well crystallised CuAlO2 powders and thick films from CuO and boehmite or alumina, using a novel molten salt painting process. We examine the formation mechanism using X-ray diffraction, scanning electron microscopy, energy dispersive X-ray 15 spectroscopy and in situ high temperature X-ray diffraction and find that the annealing atmosphere plays a critical role. From this we develop a method to create Cu-Al2O3 conductive metal-ceramic composite materials with novel morphologies via the thermal decomposition of CuAlO2 precursor films

Vibrational Coupling in Conjugated π Systems with a view to Optimization of Fluorescence Yield through Phonon Confinement

A series of π conjugated systems were studied by absorption, photoluminescence and vibrational spectroscopy. As is common for these systems, a linear relationship between the positioning of the absorption and photoluminescence maxima plotted against inverse conjugation length is observed. The relationships are in good agreement with the simple particle in a box method, one of the earliest descriptions of the properties of one-dimensional organic molecules. In addition to the electronic transition energies, it was observed that the Stokes shift also exhibited a well-defined relationship with increasing conjugation length, implying a correlation between the electron-vibrational coupling and chain length. This correlation is further examined using Raman spectroscopy, whereby the integrated Raman scattering is seen to behave superlinearly with chain length. There is a clear indication that the vibrational activity and thus nonradiative decay processes are controllable through molecular structure. The correlations between the Stokes energies and the vibrational structure are also observed in a selection of PPV based polymers and a clear trend of increasing luminescence efficiency with decreasing vibrational activity and Stokes shift is observable. The implications of such structure property relationships in terms of materials design are discussed

The FRET Signatures of Noninteracting Proteins in Membranes: Simulations and Experiments

AbstractFörster resonance energy transfer (FRET) experiments are often used to study interactions between integral membrane proteins in cellular membranes. However, in addition to the FRET of sequence-specific interactions, these experiments invariably record a contribution due to proximity FRET, which occurs when a donor and an acceptor approach each other by chance within distances of ∼100 Å. This effect does not reflect specific interactions in the membrane and is frequently unappreciated, despite the fact that its magnitude can be significant. Here we develop a computational description of proximity FRET, simulating the cases of proximity FRET when fluorescent proteins are used to tag monomeric, dimeric, trimeric, and tetrameric membrane proteins, as well as membrane proteins existing in monomer-dimer equilibria. We also perform rigorous experimental measurements of this effect, by identifying membrane receptors that do not associate in mammalian membranes. We measure the FRET efficiencies between yellow fluorescent protein and mCherry-tagged versions of these receptors in plasma-membrane-derived vesicles as a function of receptor concentration. Finally, we demonstrate that the experimental measurements are well described by our predictions. The work presented here brings additional rigor to FRET-based studies of membrane protein interactions, and should have broad utility in membrane biophysics research