Magnetic, telluric and magnetotelluric measurements at the Travale test site, Tuscany, 1980–1983: An overview

The initial problems associated with the fieldwork and integration of the results of four independent European university research groups involved in magnetotelluric studies in the Travale Test Site are discussed. This is followed by an account of the development of collaborative field studies, rewarding data and computer programme interchange and finally compatibility in the resulting electrical conductivity models and their interpretation. A suggested strategy for future EEC collaborative geothermal studies concludes this overview.     

The MUC2 gene product: a human intestinal mucin

Sera from 82 cases of leptospirosis (confirmed by micro-agglutination tests or IFAT) and 108 patients with other diseases were investigated using the microcapsule agglutination test (MCAT) for leptospirosis. The overall sensitivity (90.2%), specificity (96.3%), positive predictive value (94.9%), negative predictive value (92.9%), and accuracy of the MCAT (93.7%) were encouraging. MCAT is simple, can be performed by unskilled personnel with minimum laboratory facilities, and produces results in 3 h. MCAT would be a reliable serodiagnostic test for rapidly screening individuals for leptospirosis, in various geographical areas of Thailand.     

Transmission-based scatter correction of 180 degrees myocardial single-photon emission tomographic studies

Meaningful comparison of single-photon emission tomographic (SPET) reconstructions for data acquired over 180 degrees or 360 degrees can only be performed if both attenuation and scatter correction are applied. Convolution subtraction has appeal as a practical method for scatter correction; however, it is limited to data acquired over 360 degrees. A new algorithm is proposed which can be applied equally well to data acquired over 180 degrees or 360 degrees. The method involves estimating scatter based on knowledge of reconstructed transmission data in combination with a reconstructed estimate of the activity distribution, obtained using attenuation correction with broad beam attenuation coefficients. Processing is implemented for planes of activity parallel to the projection images for which a simplified model for the scatter distribution may be applied, based on the measured attenuation. The appropriate broad beam (effective) attenuation coefficients were determined by considering the scatter buildup equation. It was demonstrated that narrow beam attenuation coefficients should be scaled by 0.75 and 0.65 to provide broad beam attenuation coefficients for technetium-99m and thallium-201 respectively. Using a thorax phantom, quantitative accuracy of the new algorithm was compared with conventional transmission-based convolution subtraction (TDCS) for 360 degrees data. Similar heart to lung contrasts were achieved and correction of 180 degrees data yielded a 10.4% error for cardiac activity compared to 5.2% for TDCS. Contrast for myocardium to ventricular cavity was similarly good for scatter-corrected 180 degrees and 360 degrees data, in contrast to attenuation-corrected data, where contrast was significantly reduced. The new algorithm provides a practical method for correction of scatter applicable to 180 degrees myocardial SPET.     

Influence of alginite on the reflectance of vitrinite from Joadja,NSW, and some other coals and oil shales containing alginite

Reflectance data for vitrinite occurring in torbanites indicate that the mean maximum reflectance and the range of reflectance values are significantly lowered by the presence of alginite. This is the probable cause of apparently anomalous rank gradients in some deep oil exploration wells. Intermaceral effects need to be considered in assessing rank or maturity from vitrinite reflectance, and by inference, in most other methods. The interpretation of the cause of the effect is open to further study but the findings are highly significant in relation to coal utilization, oil and gas exploration, and studies of oil shales.     

Optical Storage Interactive Simulator (oasis): An Interactive Tool for the Analysis of Page-Oriented Optical Memories

Page-oriented optical memories combine high capacity with massive data-transfer rates and could provide the next generation of secondary storage systems. Several technological barriers need to be overcome before these memories become commercial products. One is the need for efficient interfaces to electronic computers. To assist in the analysis of all issues pertaining to such an interface, we have developed the optical storage interactive simulator (oasis), an interactive software tool. oasis can simulate data-encoding schemes, noise sources present in a particular memory system, and data-recovery mechanisms. Bit-error rates and other useful statistics can also be measured. The user has the option of studying the effects of individual error sources to the system output or of applying several of them in any order dictated by the system architecture. This multifaceted analysis will assist the user in evaluating the effectiveness of a particular error-correcting code and choosing the right one for the system.     

Nondestructive NMR determination of oil composition in transformed canola seeds

Magic-angle spinning (MAS) ¹³C nuclear magnetic resonance (NMR) spectroscopy is a convenient method for nondestructive, quantitative characterization of seed oil composition. We describe results for intact hybrid and transformed canola seeds. The MAS ¹³C NMR technique complements and agrees with gas chromatography results. The spectral resolution approaches that of neat, liquid oils. MAS ¹³C NMR data allow quantitative analysis of major oil components, including saturates and oleic, linoleic, and linolenic acyl chains. ¹³C NMR directly and quantitatively elucidates, triglyceride regiochemistry and acyl chain cis-trans isomers that cannot be quickly detected by other methods. MAS ¹³C NMR can serve as the primary method for development of near-infrared seed oil calibrations. These NMR methods are nondestructive and attractive for plant-breeding programs or other studies (e.g., functional genomics) where loss of seed viability is inconvenient.