DETERMINATION OF ALDICARB SULFONE IN HYDROPONICALLY GROWN CUCUMBERS

During a two week period, several residents of a small Nebraska community experienced violent illnesses with short duration following ingestion of locally grown hydroponic cucumbers (Goes et al. 1979). Approximately a year later during another two week period, a second similar outbreak occurred. In each incident those who ingested hydroponic cucumbers experienced similar illnesses. All of the cucumbers were grown at the same greenhouse. The carbamate insecticide aldicarb, was detected in some cucumbers grown at the hydroponic greenhouse.
The aldicarb was determined as aldicarb sulfone (a metabolite) by gas chromatography employing a flame photometric detector (FPD) with a 394 mμ filter selective for sulfur-containing compounds. Separate calibration curves, derived from aldicarb sulfone, are required for the quantitation.     

Study of the Degradation Products Formed During Extrusion Lamination of an lonomer

Headspace concentration techniques were used to tentatively identify the volatile products formed during the extrusion process of thermoplastic polymers to produce ionomers which have many applications as food packaging materials. Compounds representing alcohols, aldehydes, ketones, and hydrocarbons were tentatively identified. Time/temperature studies showed that the quantity of compounds formed depended on the conditions used for resin processing. The rate of release of compounds was also found to be temperature dependent. Sensory evaluation data confirmed the instrumental findings.     

Biological Evaluation of Protein Quality of Radiation-Pasteurized Haddock, Flounder and Crab

SUMMARY— The effects of radiation sub-sterilization or heat-treatment on the protein quality of haddock, crab and flounder were evaluated by determining the protein efficiency ratio (PER). The PER value of haddock radiated at either level was statistically equal to that of non-radiated haddock. The PER value of crab radiated at either level was statistically equal to non-radiated crab in one replication and significantly higher than non-radiated crab in another replication. The PER value of flounder radiated at the low level was significantly less than that of non-radiated flounder, whereas the PER value of flounder radiated at the high level was statistically equal to that of non-radiated flounder. Low PER values were obtained for heat-treated marine products and these values were significantly lower than those for all other marine product treatments investigated. The protein quality of haddock, crab and flounder was not significantly changed as a result of radiation pasteurization.     

Kinetics of Malvidin-3-Glucoside Condensation in Wine Model Systems

Wine model systems containing equimolar quantities of malvidin-3-glucoside and d-catechin, with and without acetaldehyde, were stored anaerobically at 22, 32, 42, and 52°C. Malvidin-3-glucoside and d-catechin disappearance and polymer appearance were monitored by HPLC and colorimetric methods. Reaction rates and activation energies were calculated. The malvidin-3-glucoside and d-catechin condensation reactions showed pseudo first order kinetics both with and without the presence of acetaldehyde. However, activation energies were not significantly different.     

The parallel downhill simplex algorithm for unconstrained optimisation

In this paper we present a parallel implementation of a well-known heuristic optimisation algorithm (the downhill simplex algorithm developed by Nelder and Mead in 1965) which is well suited for unconstrained optimisation. We present the sequential algorithm as well as the parallel algorithm which we used to generate numerical results. They include numerical results of experiments on neural networks and a test suite of functions which demonstrate the parallel algorithm's increased robustness and convergence rate for high-dimensional problems compared to the sequential algorithm. © 1998 John Wiley & Sons, Ltd.     

INSTRUMENTAL MULTIPLE TEXTURE PROFILE ANALYSIS OF COOKED GROUND BEEF PATTIES AND SMOKED BEEF

An instrumental texture profile for cooked hamburger patties was obtained by repeated tests on the same samples in the wire extrusion cell of the Ottawa Texture Measuring System. The correlation between sensory and instrumental texture profile parameters was increased when two or more instrument test cycles were applied to each sample in the same test cell. Tests with smoked beef and hamburger patties showed that the change in textural characteristics with repeated cycles depended on the texture of the food.     

Cell adhesion in renal tubular epithelial cells: Biochemistry,biophysics or both

Changes in cell-cell and cell-substrate adhesion markers are increasingly used to characterize disease onset and progression. However, these relationships depend on both the biochemical and molecular association between cells and between cells and their extracellular matrix, as well as the biophysical and mechanical properties orchestrated by cytoskeletal, membrane and matrix components. To fully appreciate the role of cell adhesion when determining normal physiology and the impact of disease on cellular function, it is important to consider both biochemical and biophysical attributes of the system being investigated. In this short viewpoint we reflect on our experiences assessing cell-cell and/or cell-matrix interactions in renal tubular epithelial cells.