Using health status surveys in medical consultations

The goal of this research was to identify patients' preferences for physician inquiry into various aspects of health status and to examine whether the preconsultation availability of health status data (collected from the SF-36 Health Status Questionnaire) influenced the physician's conduct during the consultation. Results from 58 prenatal patient visits yielded the following findings. First, patients expressed strong preferences for physicians to ask about the patient's perceptions of health in general and about physical dimensions of health status such as pain, vitality, and role limitations due to physical functioning. Patients also were more satisfied when doctors were perceived as having asked about these issues. Second, patients varied considerably in their preferences for physician inquiries into psychosocial issues such as social functioning, mental health, and role limitations due to emotional problems. Approximately half the patients wanted these matters discussed, whereas the remainder either did not care or preferred that doctors not ask about these topics. Third, the preconsultation availability of health status information had little effect on the degree to which physicians asked about the patient's health-related quality of life. Clinical implications are discussed.     

Environmental and Genotypic Influences on Isoquinoline Alkaloid Content in Sanguinaria canadensis

In a common garden, we investigated genetic and environmental influences on alkaloid production using Sanguinaria canadensis as a model. Nutrient and shade regimes were applied to replicated clones over one growing season, and induction of alkaloid production in bloodroot was tested on a whole-plant basis using jasmonic acid as an elicitor. Alkaloid concentrations increased with decreasing light intensity and fertilizer levels. Induction was not achieved by foliar application of jasmonic acid. Genetic influences represented by clone effects may be indicated by variation in alkaloid concentration by clone, but this experimental design did not allow us to distinguish genetic from pre-experiment environmental influences on the rhizomes.     

A Genetically-Based Latitudinal Cline in the Emission of Herbivore-Induced Plant Volatile Organic Compounds

The existence of predictable latitudinal variation in plant defense against herbivores remains controversial. A prevailing view holds that higher levels of plant defense evolve at low latitudes compared to high latitudes as an adaptive plant response to higher herbivore pressure on low-latitude plants. To date, this prediction has not been examined with respect to volatile organic compounds (VOCs) that many plants emit, often thus attracting the natural enemies of herbivores. Here, we compared genetically-based constitutive and herbivore-induced aboveground vegetative VOC emissions from plants originating across a gradient of more than 10° of latitude (>1,500 km). We collected headspace VOCs from Asclepias syriaca (common milkweed) originating from 20 populations across its natural range and grown in a common garden near the range center. Feeding by specialist Danaus plexippus (monarch) larvae induced VOCs, and field environmental conditions (temperature, light, and humidity) also influenced emissions. Monarch damage increased plant VOC concentrations and altered VOC blends. We found that genetically-based induced VOC emissions varied with the latitude of plant population origin, although the pattern followed the reverse of that predicted—induced VOC concentration increased with increasing latitude. This pattern appeared to be driven by a greater induction of sesquiterpenoids at higher latitudes. In contrast, constitutive VOC emission did not vary systematically with latitude, and the induction of green leafy volatiles declined with latitude. Our results do not support the prevailing view that plant defense is greater at lower than at higher latitudes. That the pattern holds only for herbivore-induced VOC emission, and not constitutive emission, suggests that latitudinal variation in VOCs is not a simple adaptive response to climatic factors.     

Effects of Elevated CO<Subscript>2</Subscript> and Herbivore Damage on Litter Quality in a Scrub Oak Ecosystem

Atmospheric CO₂ concentrations have increased dramatically over the last century and continuing increases are expected to have significant, though currently unpredictable, effects on ecosystems. One important process that may be affected by elevated CO₂ is leaf litter decomposition. We investigated the interactions among atmospheric CO₂, herbivory, and litter quality within a scrub oak community at the Kennedy Space Center, Florida. Leaf litter chemistry in 16 plots of open-top chambers was followed for 3 years; eight were exposed to ambient levels of CO₂, and eight were exposed to elevated levels of CO₂ (ambient + 350 ppmV). We focused on three dominant oak species, Quercus geminata, Quercus myrtifolia, and Quercus chapmanii. Condensed tannin concentrations in oak leaf litter were higher under elevated CO₂. Litter chemistry differed among all plant species except for condensed tannins. Phenolic concentrations were lower, whereas lignin concentrations and lignin/nitrogen ratios were higher in herbivore-damaged litter independent of CO₂ concentration. However, changes in litter chemistry from year to year were far larger than effects of CO₂ or insect damage, suggesting that these may have only minor effects on litter decomposition.     

In situ observation of dynamic elastic modulus in polypyrrole actuators

Polypyrrole is a leading conducting polymer actuator, but the factors that influence its performance when actuated under load in devices (such as the polymer stiffness) are not yet fully understood. To this end, we have probed the dynamic elastic modulus of polypyrrole in situ during actuation in a variety of electrolytes. As part of this study, we demonstrate that the electroactive response in dilute 1-butyl-3-methylimidazolium hexafluorophosphate can be changed from cation- to anion-dominated by adjusting the applied potential waveform. We observe that when conservative electrochemical conditions are applied in order to avoid dual ion movement or significant transfer of neutral solvent, the stiffness is determined by level of counterion swelling. The elastic modulus decreases during the net influx of ions into the bulk polymer and increases as these ions are expelled, regardless of whether the electroactive response is cation- or anion-dominated or whether there is a neutral solvent present in the electrolyte. This effect is quite significant, and we have observed up to a 3× increase in elastic modulus upon actuation in neat 1-butyl-3-methylimidazolium hexafluorophosphate.     

Electronically Tunable Filters

In this article, a brief introduction to the development of tunable filters was given. A classical design technique based on a combline filter approach was shown, where minimum degradation in passband performance could be obtained across a broad-tuning range. The fundamental disadvantages associated with the conventional resonator tuning approaches were also discussed, recognizing the importance of developing new techniques for realizing tunable microwave filters. It was shown that there is a possibility in realizing an electronically reconfigurable microwave filter based on parallel- coupled switched-delay lines, which possesses the important property of maintaining constant absolute bandwidth over almost an octave of tuning bandwidth. Furthermore, the filter has the ability to incorporate active switching elements in the filter circuit, without sacrificing its loss and linearity performance. With the exceptional linearity performance and power handling capability, the filter is readily adapted to poor environments. Although the use of p-i-n diodes as switching elements would result in large dc consumption, the approach could also be readily adapted for use with any switches, such as pHEMT or RF MEMS switches, to achieve extremely low power consumption. The integration of switchable couplings to enable both bandwidth and center frequency to be reconfigurable would be an enhancement.     

The electron trapping behavior of silicon dioxide with ion implanted aluminum

The electron trapping behavior of SiO₂ films implanted with Al has been studied by Johnson, Johnson, and Lampert¹ and they conclude that the trapping is occuring in damage sites resulting from the implantation. They used annealing temperatures up to 600C. We find that the trapping is reduced further as we increase the annealing temperature up to 1050C. We have characterized the traps and find that the predominate traps have cross sections of 1.26 × 10⁻¹⁶ and 1.4 × 10⁻¹⁷cm². The trapping is proportional to the fluence and is not a strong function of the measuring temperature. The centroid of the trapped charge is close to the centroid of the implanted Al as predicted by the LSS theory⁶.     

The separation of coal fines using flowing-film gravity concentration

This paper reviews the results of a broadly based investigation into the possible merits of treating coal fines using flowing-film gravity separators such as Reichert cones, trays and spirals. The work was carried out in the test facilities maintained by Mineral Deposits Limited (MDL) both within Australia and in several overseas locations. In the initial phase, the cost of the work was borne by MDL, but funding for the second phase, which had wider terms of reference, was supplied by a grant from the National Energy Research, Development and Demonstration Council (NERDDC). The project is expected to continue until mid-1984, but the assessments of the tray and spiral separators are complete and form the main subject of this paper.     

Mercury levels in freshwater fish of the state of South Carolina

Samples of fish from freshwater sources of rivers, lakes and ponds all over the state of South Carolina were collected during the Summer of 1974 and 1975. The fish collected were Bass, Bluegill, Redbreast, Catfish, Shad, Carp, Crappie, Mudfish and Pike. Samples were analyzed using the flameless atomic absorption procedure outlined by Hatch and Ott, and Uthe et al as modified for use with Perkin-Elmer, Coleman MAS-50 mercury analyzer. Triplicate samples of fish tissue were analyzed by wet digestion method. The mean mercury levels in ppb were determined for baseline mercury levels. A significant finding of this report is that those species for which fish of widely differing weights were analyzed, larger fish had higher mercury levels. Mercury levels exceeding the U.S. Food and Drug Administration guideline of 500 ppb for fish tissues have been found in the Mudfish from Edisto River and Pike fish from Lake Murray. Higher levels of mercury occurred in the highly vascularized blood tissues of liver and kidney than in muscle. Carnivorous and bottom-feeding fishes are the most reliable indicators of mercury pollution.