Isoflurane minimum alveolar concentration sparing effects of fentanyl in the dog

Objective

To characterize the isoflurane-sparing effects of a high and a low dose of fentanyl in dogs, and its effects on mean arterial pressure (MAP) and heart rate (HR).

Testing for antibacterial properties of cotton/flax denim

The ‘AATCC Test Method 100-1999, Antibacterial Finishes on Textile Materials: Assessment of’ was modified by not assaying for the initial population density and only reporting the population density at the end of incubation for comparing treatments. This seemed to be a reasonable change since the assay challenges the treatments at the start with the same population inoculum density. This permitted the AATCC Test Method 100-1999 to be flexible and easier for testing materials that may or may not actually exhibit bacteriostatic properties. A substantial savings in material and time was gained by not taking the initial population density. This change allows testing more treatments, using more replicate samples, or shortens the time to conduct the assay which can permit more assays to be conducted. However, the control treatment needs to be integral with each assay; but since this is usually done, this would be a small inconvenience compared to the savings. The assay responded well when used to test fabric containing variable amounts of material with known antibacterial properties. The population density of the challenge bacteria decreased as the concentration of the antibacterial component of the fabric increased. The results from the use of the modified AATCC Test Method 100-1999 assay did not indicate that adding flax provided any additional bacteriostatic properties to the flax denim against the two challenge bacteria, Staphylococcus aureus and Klebsiella pneumoniae. The long held assumption that flax is bacteriostatic or antibacterial was not supported by the results and probably does not contribute to its resistance to rotting as much as its physical or chemical composition.     

HD 181068: a red giant in a triply eclipsing compact hierarchical triple system

Hierarchical triple systems comprise a close binary and a more distant component. They are important for testing theories of star formation and of stellar evolution in the presence of nearby companions. We obtained 218 days of Kepler photometry of HD 181068 (magnitude of 7.1), supplemented by ground-based spectroscopy and interferometry, which show it to be a hierarchical triple with two types of mutual eclipses. The primary is a red giant that is in a 45-day orbit with a pair of red dwarfs in a close 0.9-day orbit. The red giant shows evidence for tidally induced oscillations that are driven by the orbital motion of the close pair. HD 181068 is an ideal target for studies of dynamical evolution and testing tidal friction theories in hierarchical triple systems.     

Cardiovascular and respiratory effects of two doses of fentanyl in the presence or absence of bradycardia in isoflurane-anesthetized dogs

Objective

To compare the cardiopulmonary effects of low and high doses of fentanyl before and after the correction of bradycardia in isoflurane-anesthetized dogs.

Electronic structure and catalytic behavior of tungsten carbide

Tungsten carbide has been shown to be an effective catalyst for a number of reactions that are readily catalyzed by platinum, but not at all by tungsten, and it was speculated that this behavior is due to changes in the electron distribution when carbon is added to tungsten. A test of this hypothesis, made by measuring the valence band x-ray photoelectron spectrum of tungsten carbide and comparing it with the spectra of tungsten and platinum, shows that, near the Fermi level, the electronic density of states of tungsten carbide more nearly resembles that of platinum than that of tungsten.     

On the Thermal Boundary Layer of the Ocean

Measurement of the long-wave infrared radiation from the top 0.1 mm of the evaporating ocean demonstrates the existence of a cool surface layer characterized by departures of as much as 0.6 degrees C from the "surface temperature" found by conventional methods. Being very thin, the layer cools sufficiently rapidly to reestablish itself in less than 12 seconds after disruption by a breaking wave.     

Development and use of an attenuated total reflectance/fourier transform infrared (ATR/FT-IR) spectral database to identify foreign matter in cotton

The presence of foreign matter in cotton seriously affects the cotton grade and thus the price per bale paid by the spinner to the grower, the efficiency of the spinning and ginning operations, and the quality of the final woven product. Rapid identification of the nature of the extraneous matter in cotton at each stage of cleaning and processing is necessary to permit actions to eliminate or reduce its presence and improve efficiency and quality. Although several instruments are being successfully employed for the measurement of contamination in cotton fibers based on particle size/weight, no commercial instrument is capable of accurate qualitative identification of contaminants. To this end, ATR/FT-IR spectra of retrieved foreign matter were collected and subsequently rapidly matched to an authentic spectrum in a spectral database. The database includes contaminants typically classified as "trash", cotton plant parts (hull, shale, seed-coat fragments, bract, cacyx, leaf, bark, sticks, and stems) and grass plant parts (leaf and stem); "foreign objects and materials", synthetic materials (plastic bags, film, rubber, bale wrapping and strapping); organic materials (other fibers, yarns, paper, feathers, and leather); plus entomological and physiological sugars and inorganic materials (sand and rust). The spectral matching resulted in consistently high-score identification of the foreign matter based on chemical composition, irrespective of its particle size. The method is envisioned to be employed with stand-alone rugged infrared instrumentation to provide specific identification of extraneous materials in cotton as opposed to only general classification of the type by particle size or shape.     

The measurement of soil fungal:bacterial biomass ratios as an indicator of ecosystem self-regulation in temperate meadow grasslands

 There is much interest in the development of agricultural land management strategies aimed at enhancing reliance on ecosystem self-regulation rather than on artificial inputs such as fertilisers and pesticides. This study tested the usefulness of measures of soil microbial biomass and fungal:bacterial biomass ratios as indicators of effective conversion from an intensive grassland system, reliant mainly on fertilisers for crop nutrition, to a low-input system reliant mainly on self-regulation through soil biological pathways of nutrient turnover. Analysis of soils from a wide range of meadow grassland sites in northern England, along a gradient of long-term management intensity, showed that fungal:bacterial biomass ratios (measured by phospholipid fatty acid analysis; PLFA) were consistently and significantly higher in the unfertilised than the fertilised grasslands. There was also some evidence that microbial biomass, measured by chloroform fumigation and total PLFA, was higher in the unfertilised than in the fertilised grasslands. It was also found that levels of inorganic nitrogen (N), in particular nitrate-N, were significantly higher in the fertilised than in the unfertilised grasslands. However, microbial activity, measured as basal respiration, did not differ between the sites. A field manipulation trial was conducted to determine whether the reinstatement of traditional management on an improved mesotrophic grassland, for 6 years, resulted in similar changes in the soil microbial community. It was found that neither the cessation of fertiliser applications nor changes in cutting and grazing management significantly affected soil microbial biomass or the fungal:bacterial biomass ratio. It is suggested that the lack of effects on the soil microbial community may be related to high residual fertility caused by retention of fertiliser N in the soil. On the basis of these results it is recommended that following the reinstatement of low-input management, the measurement of a significant increase in the soil fungal:bacterial biomass ratio, and perhaps total microbial biomass, may be an indicator of successful conversion to a grassland system reliant of self-regulation. Received: 4 May 1998