Measurement of water in rhyolitic glasses; calibration of an infrared spectroscopic technique

A series of natural rhyolitic obsidians were analyzed for their total water contents by a vacuum extraction technique. The grain size of the crushed samples can significantly affect these analyses. Coarse powders must be used in order to avoid surface-correlated water. These analyses were used to calibrate infrared spectroscopic measurements of water in glass using several infrared and near-infrared absorption bands. We demonstrate that infrared spectroscopy can yield precise determinations of not only total dissolved water contents, but also the concentrations of individual H-bearing species in natural and synthetic rhyolitic glasses on spots as small as a few tens of micrometers in diameter

PRWAD and the Seventies

Non

A Comparison of the Anxiety Measures and Match Performance Evaluations of High School Wrestlers

The purpose of this investigation was to determine if an individual high school wrestler’s anxiety measures would serve as an indicator of his match performance. The subjects were thirty-one varsity wrestlers who were in attendance at Brookings High School, Brookings, South Dakota, during the academic year 1966-1967. The top twenty-four wrestlers, as determined by weekly competitive challenge matches, received alternate forms of the IPAT 8-Parallel-Form Anxiety Battery forty minutes prior to the “A” and “B” teams’ competitive performances in all home wrestling matches. These tests were administered in order to measure the anxiety levels of subjects in a stress situation. Each subject’s performance was independently evaluated immediately upon the termination of his match by a panel of three wrestling judges. The mean of these judges’ ratings served as the subject’s match performance evaluation. A base line anxiety measure in a non-stress situation was secured by administering Form F of the IPAT 8-Parallel-Form Anxiety Battery to the subjects. The data collected during these testing periods were scored and/or recorded and analyzed to determine the degree of relationship existing between the subject’s anxiety measures and their match performance evaluations. The statistical procedures employed on data of individual subjects dealt only with those subjects who wrestled a minimum of five of the seven matches investigated. There were no statistically significant findings on any of the correlations in the data analyzed. These results would tend to indicate that for the purposes of this study, the anxiety measures as employed were unreliable methods for the prediction of competitive performance

Prevalence and diagnosis of Parkinson's disease: a community study

Clinicopathological and community studies have demonstrated misdiagnosis in Parkinson’s disease (PD). Clinical trials of antiparkinson medication have also shown a subset of patients labelled as having PD have normal functional brain dopaminergic imaging. Conditions commonly misdiagnosed as PD include Essential tremor (ET), vascular Parkinsonism (VP) and dystonic tremor (DT). This thesis examines the accuracy of clinical diagnosis of PD in a community setting by identifying misdiagnosed cases and supervising antiparkinson medication withdrawal. Prescription database searches and GP case record review were carried out in 92 West Scotland GP practices within a population of 511,927. 610 patients on antiparkinson medication for a PD diagnosis were identified and age-adjusted prevalence was 129.5 per 100,000. Patients were invited for assessment if there was (a) no increase in dopaminergic drug dose or (b) no recorded progression of disease over time, suggestive of possible misdiagnosis. 64 patients were assessed and this was supplemented with FP-CIT SPECT scanning in 25 uncertain cases. Patients considered unlikely to have PD were advised to reduce and discontinue antiparkinson drugs, with repeat PD motor scoring over 6 months. 33 of 64 patients (51.6%) successfully completed antiparkinson medication withdrawal. An age, sex and disease duration matched control group was also assessed. The selection criteria allowed identification of a high proportion of misdiagnosed cases and FP-CIT SPECT was a useful diagnostic tool for assessing patients (previously diagnosed as PD) in whom there was diagnostic doubt

PHYSIOLOGICAL RESPONSES OF GRACILARIOPSIS LONGISSIMA TO COPPER EXPOSURE

Seaweeds fulfil many of the criteria regarded as being important for a good biomonitor. They are known to accumulate trace metals and the concentration of these metals measured in the thalli of native populations has been related to the level of contamination in the surrounding water. However, this passive biomonitoring approach has been of limited use and the relationship between the concentration of metal in the seaweed and that in the surrounding environment is not always apparent. The aim of this study was to investigate the response of the rhodophyte Gracilariopsis longissima to copper exposure, in the laboratory and field, in order to increase the understanding of the toxic effects of the metal and ultimately to assess the potential of this species as a biomonitor of trace metal pollution. A series of comparative physiological experiments were performed to assess the relative effects of copper on the growth and physiology of the species. Growth was reduced at significantly lower levels of copper {l2µg Lˉ¹) than any other physiological parameter measured. Photosynthesis, as measured by oxygen evolution and fluorescence measurements, was only reduced at high copper treatments (250-400µg Lˉ¹). This coincided with the actual shrinkage of the algal material, increased ion leakage and loss of pigmentation. One possible explanation for the uncoupling of growth from photosynthesis was investigated and rejected. Copper accumulated in the thallus of exposed material as a linear function of the copper treatment. Algal material was able to recover, in terms of growth, following exposure to elevated levels of copper. This recovery coincided with a significant release of copper from the thalli and a resulting increase of copper in the recovery media. This discovery suggests that the accumulated metal is not irreversibly bound to the thalli, and has important implications in terms of using the species as a biomonitor of copper pollution. Populations of G. longissima collected from sites known to differ in trace metal contamination were exposed to copper in a series of laboratory based experiments to measure the effect of the metal on their growth. Exposure to elevated levels of copper significantly reduced growth. However, no major difference existed between the response of the populations compared. Possible explanations for this are discussed. Considerable inter and intra-individual variability was found to exist within populations of G. longissima and causes and implications of this mostly overlooked source of variation are highlighted. A field method of active biomonitoring using reciprocally transplanted individuals was developed as an alternative to passive biomonitoring and was found to offer a number of distinct advantages. In particular, the ability to observe responses to copper in areas where no natural population occurred was explored at a highly contaminated site

Real-time system for determining corn plant population in-situ at harvest time

Producers and seed companies have recently expressed interest in documenting spatial variation in com plant population. In order to measure plant population at harvest-time, the number of com stalks feeding into the harvester must be known. A system has been developed to measure plant population on a combine com header. It uses a non-intrusive capacitive technique to sense com stalks as they enter the header. Stalks pass the sensor face, and an increase in voltage is produced due to a change in sensor capacitance. This voltage increase is recorded as one com stalk. The system was prototyped and tested in both laboratory and field environments. Test results show that the system is capable of measuring plant population to some degree of accuracy. Accuracy measurements were based on manual stalk counts performed before harvesting. Field tests were inconclusive due to insect damage coupled with late season harvest resulted in a severally lodge crop. Accuracy was moderately correlated with speed (r = 0.43: α=0.05). Refinements in sensor head design and measurement circuitry are needed to improve measurement accuracy. Future tests should include com stalks of various moisture contents to determine if moisture related problems exist

Britain and the Baltic

http://tartu.ester.ee/record=b2166206~S1*es