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Oral hygiene nursing aide intervention may be an efficient risk factor modifier of mortality from nursing home-associated pneumonia.

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Rainfall simulation at an average intensity of 124 mm·h was used to compare infiltration and run off on arid areas where subterranean termites had been eliminated four years prior to the initiation of the study (termite free) with adjacent areas populated by subterranean termites (termites present). Infiltration rates on termite free plots with less than 5% perennial plant cover were significantly lower 51.3±6.8 mm·h than rates on comparable termites present plots 88.4±5.6 mm·h. On plots centered on Larrea tridentata shrubs, there were no differences in infiltration rates with or without termites. Plots with shrub cover had the highest infiltration rates 101±6 mm·h. Highest run-off volumes were recorded from termite free <5% grass cover plots and the lowest from plots with shrubs. There were no differences in suspended sediment concentrations from termites present and termite free plots. Average bed load concentration was more than three times greater from termite free, <5% cover plots than from termites present, <5% cover plots.The reduction in infiltration, high run-off volumes and high bedloads from termite free areas without shrub cover is related to increased soil bulk density resulting from the collapse of subterranean galleries of the termites that provide avenues of bulk flow into the soil. Subterranean termites affect the hydrology of Chihuahuan desert systems by enhancing water infiltration and retention of top soil. The presence of a shrub canopy and litter layer cancels any effect of subterranean termites on hydrological parameters. Since approximately 2/3 of the area is not under shrub canopies, subterranean termites are considered to be essential for the maintenance of the soil water characteristics that support the present vegetation.

Gas Chromatography (GC). The separation of enantiomers by GC on CSPs was extensively reviewed by Schurig (12), with discussion of the method development, applications, and ancillary techniques of chiral separations using GC. CSPs with amino acid derivatives, terpene-derived metal coordination compounds, and modified cyclodextrins were included. Schurig also comprehensively reviewed the practice and theory of enantioselective complexation GC on optically active metal(II) bis[3-perfluoroacyl)-(1R)-camphorate] selectors (13). Applications extend to chiral analysis in asymmetric synthesis, enzymic reactions, pheromone, and flavor chemistry. The elucidation of thermodynamic parameters of enantioselectivity and the investigation of the enantiomerization of configurationally labile enantiomers was also discussed.Thin-Layer Chromatography (TLC). The development of stationary phases for TLC in the last 10 years was compiled by Gocan ( 14), and included chiral separation and recent advances in chiral stationary phases. The CSPs discussed included nonpolar bonded stationary phases impregnated with transitional metal ions, cellulose, modified cellulose, chitin, chitosan, and their derivatives. Cyclodextrin and macrocyclic antibiotics were reported to have very good results for enantioseparation by TLC, with molecular imprinting polymers also finding use as CSPs in TLC.Capillary Electrochromatography. The applications of CEC were reviewed by Remcho et al. (15). Chiral separations with cyclodextrins and their derivatives, biomolecules, molecularly imprinted polymers, "brush"-type phases, ion exchangers, antibiotics, polysaccharide derivatives, and other CSPs were included in this review. A summary of recent progress in open-tubular CEC for chiral and achiral separations included stationary-phase preparation ( 16), with the major developments, potential applications, technical difficulties, and advantages of each wall coating discussed.Multiple Technique Reviews. The use of cyclodextrins in chiral chromatography was compiled by Juvancz and Szejtli (17). The role of cyclodextrins in methods using capillary columns such as GC, supercritical fluid chromatography (SFC), and CE was detailed, as well as their use in other forms of chromatography such as HPLC and TLC. The mechanism of chiral recognition using cyclodextrins was also discussed. Williams and Wainer (18) reviewed the role of chiral chromatography in therapeutic drug monitoring and in clinical and forensic toxicology. Enantioselective GC and HPLC were used as tools to unravel complex phenomena associated with drug transport and metabolism.

A diverse laboratory population of Daphnia magna Straus was established by combining individuals from eight sources. Artificial selection for increased resistance to the acute toxic effects of cadmium was performed, and after eight generations, the average median effective concentration increased from 61 to 180 microg/L. No differences in life span, offspring production, time to first brood, number of offspring in the first brood, or intrinsic rate of population increase (r) were observed between the cadmium-adapted population and the controls under ideal conditions or under conditions of temperature or feeding ration stress, but cadmium-adapted daphnids were smaller. Control and cadmium-adapted populations were equally sensitive to copper and malathion, but the cadmium-adapted population was less sensitive to lead and more sensitive to phenol. Analysis of amplified fragment-length polymorphisms indicated a significant decrease in genetic diversity in the cadmium-adapted population. Although the evolved cadmium resistance would allow adapted populations to exist in areas where cadmium concentrations would be toxic to unadapted populations, the decreased genetic diversity, smaller size, and increased sensitivity to at least one other toxicant could reduce the probability of long-term survival even in the absence of future cadmium exposure.