Partitioning behavior of Alkan-1-ols between milkfat and aqueous phases as influenced by temperature

Partitioning of volatile compounds between lipid and aqueous phases may influence flavor perception and availability to participate in flavor-generating reactions. The objective of this research was to characterize the partitioning of short-chain alkan-1-ols between milkfat and aqueous phases, as influenced by temperature, as compared to an octan-1-ol/water biphasic system (Log P). Temperature has a positive, but nonlinear, influence on Log P values for alkan-1-ols. There is an approximately 1 log decrease in Log P values of milkfat/water as compared to octan-1-ol/water systems; similar trends were observed across chain length. Temperature has a greater effect on alkan-1-ol partitioning in milkfat/water systems than octan-1-ol/water. The latter observation is primarily attributed to the solidification of milkfat at temperatures below 40 degrees C and the resulting reduction in liquid lipid solvent volume.     

Reduction of decomposition rates of scots pine needle litter due to heavy-metal pollution

Decomposition of unpolluted Scots pine needle litter was studied in two heavy-metal-pollution gradients in Sweden; one near a brass mill and the other around a primary smelter. In the latter area locally collected polluted Scots pine needle litter was also incubated. Decomposition rates were strongly influenced by the metal pollution and a decrease in the rate of mass-loss occurred. In the brass-mill gradient this occurred until about 1 km from the pollution source which corresponded to about 500 µg Cu and 1 000 µg Zn g^?1 soil. Data are presented to indicate that lignin decomposition was more sensitive to pollution than decomposition of whole litter and affected further away from the pollution sources. At the smelter sites, the metal-polluted needle litter decomposed more slowly than the unpolluted needle litter, and this difference was enhanced close to the smelter. The results indicate that heavy metals accumulated in needles prior to shedding have a long-term impact on the subsequent decomposition of the litter. Both litter quality and soil factors thus contribute to the reduced litter decomposition rate in metal-polluted forests. A new non-linear model with decreasing decay rate was used in the statistical evaluation. The model can be used to characterize the effects of pollution on decomposition rate.     

Relationships between Acid Ions and Carbonaceous Fly-Ash Particles in Deposition at European Mountain Lakes

The concentrations of major ions and spheroidal carbonaceous fly-ash particles (SCPs) in bulk deposition were determined in weekly samples from six European mountain lakes during 1997/98. SCPs are produced only from high temperature combustion of fossil-fuels and therefore provide an unambiguous indicator of atmospheric deposition from this source. Positive correlations were observed between SCPs and SO₄ ^2?, NO₃ ^? and NH₄ ⁺ at all sites except for some determinands at Jorisee (Switzerland) and Starolesnienske (Slovakia). Correlations between SCPs and SO₄ ^2? + NO₃ ^? were always more positive than for SCPs with 'total acid ions' (SO₄ ^2? + NO₃ ^? + NH₄ ⁺). This is in agreement with the expectation that the contribution to NH₄ ⁺ deposition made by fossil-fuels is negligible. Good positive correlations between SCPs and all acid anions were observed at Estany Redo (Pyrenees); lower but still positive correlations were observed for all acid ions with SCPs at Gossenköllesee (Austria), Lochnagar and Kårvatn (central Norway), whilst little trend in correlation was observed for Jorisee and Starolesnienske. It is suggested that this gradient reflects the influence of fossil-fuels on acid deposition in these areas. A high positive correlation was observed between SCP and Cl^? at Gossenkollesee possibly as a result of HCl from coal combustion.     

Einsatz bakterieller Antagonisten zur Bekämpfung von Krankheiten verursacht durch Rhizoctonia solani

Rhizoctonia solani is an important soil-borne pathogen causing diseases in numerous economically important crops. The pathogen R. solani can be responsible for relevant yield losses as well as on lettuce and potato. To develop a biocontrol strategy, two bacterial strains, Pseudomonas fluorescens L13–6-12 and Serratia plymuthica 3Re4–18 were evaluated against R. solani causing black scurf in potato and bottom rot in lettuce. The disease suppression effect of the two antagonists was tested as well as in a climate chamber and in the field during two vegetation periods. The results of the climate chamber experiments showed, that R. solani can significantly reduced the lettuce growth. The dry mass losses on lettuce and the disease severity on potato sprouts were significantly limited through bacterization. The antagonist L13–6-12 showed best disease suppression effect in climate chamber experiments on both crops. A significant lower disease severity was to observed in treatments with bacterial antagonists as well as on lettuce plants and harvested potato tubers during both vegetation periods. Also the dry mass losses on lettuce were clear reduced in treatments with bacterial antagonists, whereas only a partly limitation of yield losses on potato was to achieved. In summary, the results supported that the use of bacterial antagonists can be part of a control strategy against R. solani.     

Fusobacterium necrophorum and Bacteroides melaninogenicus as etiologic agents of foot rot in cattle.

Fusobacterium necrophorum (Sphaerophorus necrophorus) and Bacteroides melaninogenicus were the predominant bacteria isolated from biopsy specimens of lesions in cattle affected with foot rot. Mixed inoculums of the 2 bacteria, applied to the scarified interdigital skin or inoculated intradermally into the interdigital skin of test cattle, induced typical lesions of foot rot. Both bacteria were reisolated in large numbers from the induced lesions.     

Endotoxemia following experimental intestinal strangulation obstruction in ponies.

Experimental small intestinal strangulation obstruction was produced in anesthetized ponies. The limulus amoebocyte lysate test demonstrated the presence of endotoxin in the general circulation 60 and 120 minutes following restoration of mesenteric blood flow. Mucosal degeneration, with loss of villus epithelial cells, was demonstrated coincident with endotoxemia. The findings were consistent with an ischemia-mediated alteration in the intestinal barrier to endotoxin.     

Evaluation of auditory evoked potentials to predict depth of anaesthesia during fentanyl/fluanisone−midazolam anaesthesia in rats

Objectives To assess a method for monitoring depth of anaesthesia using components of middle latency auditory evoked potential (AEP) waveforms during anaesthesia with fentanyl/fluanisone and midazolam. Study design Prospective observational study. Animals Five female Wistar rats weighing between 210 and 250 g. Methods Implanted electrodes were used to record AEPs in animals receiving five doses of anaesthetic. Recordings were made at 5 minutes post‐injection (deep anaesthesia; no pedal withdrawal response, PWR) and then at 25 minutes (light anaesthesia; strong PWR). Responses showed five characteristic peaks occurring at 11, 14, 23, 42 and 68 ms that were measured for latency of occurrence and peak amplitude. Results Auditory evoked potential peaks P14, N23 and P42 were increased significantly in latency with successive anaesthetic injections [avg. F(1,4) = 12.53, p < 0.001; avg. F(1,4) = 10.6, p < 0.001; avg. F(1,4) = 3.9, p = 0.02, respectively]. Peak N23 showed a significant reduction in latency during the 20 minute recovery period following both the first and second anaesthetic injections (t(3) = 7.52, p = 0.005; t(4) = 5.17, p = 0.007, respectively). Peak P42 occurred significantly earlier 20 minutes following the second anaesthetic injection (t(4) = 4.75, p = 0.009). The mean overall depth of anaesthesia assessed using PWR scores was significantly correlated with the mean latency of peak N23, such that as the strength of PWR increased, N23 occurred significantly earlier (r = ?0.99, p = 0.01). The amplitude difference between peaks N23 and P42 increased after the second and third drug administrations [avg. F(1,4) = 10.65, p = 0.031 and avg. F(1,4) = 11.24, p = 0.028, respectively]. Conclusion The characteristics of these peaks, and in particular latency of peak N23, may provide a useful tool for assessing depth of anaesthesia produced by this, and possibly other anaesthetic agents.