Recovery of phenanthrene-degrading bacteria after simulated in situ persulfate oxidation in contaminated soil

A continuous-flow column study was conducted to investigate the long-term effects of persulfate oxidation on the abundance and activity of the indigenous microbial community and phenanthrene-degrading bacteria in contaminated soil from a former manufactured gas plant (MGP) site. Approximately six pore volumes of a 20 g/L persulfate solution were introduced into the column, followed by simulated groundwater for 500 days. Soil samples were collected from the surface of the soil bed and along the column length immediately before and after persulfate injection and up to 500 days following injection. Exposure to persulfate led to a 2- to 3-log reduction in total bacterial 16S rRNA genes, severe inhibition of (14)C-acetate mineralization (as a measure of general microbial activity), and a decrease in community diversity. However, relatively rapid recovery of both bacterial gene abundance and activity was observed within 30 days after persulfate exposure. Mineralization of (14)C-phenanthrene was also inhibited but did not recover until 100 days postoxidation. Known phenanthrene-degrading bacterial groups decreased to below detection limits throughout the column, with recovery times from 100 to 500 days after persulfate injection. These findings suggest that coupling biological processes with persulfate oxidation is possible, although recovery of specific contaminant degraders may occur much later than the general microbial community recovers. Furthermore, the use of total bacterial quantity or nonspecific measures of activity as a surrogate for the recovery of contaminant degraders may be inappropriate for evaluating the compatibility of chemical treatment with subsequent bioremediation.     

Casein Composition of Cow's Milk of Different Chymosin Coagulation Properties

Five good and four poor chymosincoagulating individual cow milk samples were analyzed for casein composition using hydroxyapatite chromatography and polyacrylamide gel electrophoresis to establish possible relationships between casein fractions and differences in coagulation properties.Samples exhibited wide variation in casein composition. Poor chymosincoagulating milk had higher content of γ- and degraded caseins and lower κ- and β-caseins than the good-coagulating milk. One milk sample that did not coagulate 30 min after chymosin addition had low α_S-casein concentration and an additional major casein fragment (not identified). A substantial peak representing unidentified minor caseins was apparent in a poorcoagulating milk sample, which coagulated early but whose coagulum did not become firm in 30 min. Excluding the nonclotting sample, less variability was observed in α_S-casein concentrations than in the other casein components.     

Application of Selective 29Si Isotopic Enrichment to Studies of the Structure of Calcium Silicate Hydrate (C-S-H) Gels

Selective isotopic enrichment of SiO₂ with ²⁹Si in a mixture with tricalcium silicate (C₃S) has allowed the Si from this phase to be effectively labeled during the course of the hydration reaction, thus isolating its contribution to the reaction. A double Q₂ signal has been observed in ²⁹SI solid-state MAS NMR spectroscopy of C-S-H gels of relatively low Ca/Si ratio, prepared by hydration or by carbonation of a C₃S paste. The origin of the weaker, downfield peak is discussed and tentatively attributed to bridging tetrahedra of a dreierkette silicate chain structure.     

Loss of emotional experience after traumatic brain injury: Findings with the startle probe procedure.

The authors used affective modulation of the eyeblink startle response to examine the impact of traumatic brain injury (TBI) on emotional reactions to pictures. Participants were 13 individuals with severe TBI and 24 controls. Participants were presented with pictures that differed in affective valence (e.g., mutilated bodies, erotic couples, and household objects) while the eyeblink startle response to an acoustic probe was measured. Startle amplitude was used to assess valence of emotional response, and startle latency was used to index interest in the pictures. Subjective ratings of the affect and arousal elicited by the various pictures were also obtained. TBI impaired startle potentiation to unpleasant pictures but not startle attenuation to pleasant pictures. Further, subjective ratings indicated that TBI participants found unpleasant pictures less arousing than did controls. The results are consistent with recent evidence of differential impairment in negative versus positive emotions after TBI and are discussed in relation to 2 competing explanations of startle modulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Implementation of Innovation by a Multinational Operating in Two Different Environments: A Comparative Study

The aim of the paper is to examine the innovation initiatives and processes followed by two subsidiaries of a German multinational company operating in Europe and Asia and to compare the innovativeness of their operations in these two locations. The study examined the innovation processes followed by the two subsidiary firms operating in Germany and Malaysia, the actual problems faced by them, the critical success factors involved in the implementation, and the work climates of the firms. Interestingly, it was found that both firms followed similar innovation processes. Nevertheless, different types of problems and critical success factors were applicable to both firms. The results showed that the Malaysian subsidiary faced more behavioural problems while the German subsidiary encountered more technical problems. Further, the study showed that a lack of knowledge was the common problem faced equally by both firms. The study demonstrated that the German subsidiary had better working climate compared to its counterpart in Malaysia. Finally, the German subsidiary was found to be more innovation–active than the Malaysian subsidiary as it introduced more types of innovation, interacted with more types of entity in the external environment and introduced more types of training.     

The TDS: a new device for comparing active and passive-guided touch.

A problem when comparing active and passive tactile perception of two-dimensional (2-D) stimuli is matching the active and passive tasks on all variables except the one of interest--active versus passive touch. A new computer-controlled device--the tactile display system (TDS)--has been developed to deal with this problem. The TDS tracks an "active" subject's fingertip movements during exploration of a raised line drawing and digitally records this spatio-temporal information. It then guides a passive participant's fingertip over the same path, matching for location and speed. Any difference in performance can thus be attributed to the different conditions (active versus passive) because other variables are held constant.     

Feeding linseed to increase the n-3 PUFA of pork: fatty acid composition of muscle, adipose tissue, liver and sausages

Eighty pigs, male and female littermate pairs, were fed a control or a test diet from 25 to 95 kg live weight. The diets, as fed, contained 15.5 g/kg linoleic acid (18:2) and 1.9 g/kg α-linolenic acid (18:3) (control) or 10 g/kg linoleic acid and 4 g/kg α-linolenic acid (test). The test diet, with added linseed, was, therefore, high in the main n-3 polyunsaturated fatty acid (PUFA) 18:3 and low in the main n-6 PUFA 18:2. Making this relatively small change led to a 56% increase in the content of 18:3 in muscle and major increases in the contents of the beneficial longer chain PUFAs EPA (20:5n-3) (100% increase) and DHA (22:6n-3) (35% increase) which are synthesised from 18:3n-3. Levels of EPA and DHA in pigmeat adipose tissue were also increased by the test diet. In liver, the test diet resulted in an 18:3 level 4× higher than in muscle, with 10× more EPA and 20× more DHA. Sausages, analysed after 6 months frozen storage also had high n-3 PUFA levels, due to the contribution of these fatty acids from both muscle and adipose tissue. From a health perspective these results confirm the potential of pigmeat to supply valuable n-3 PUFA to the human diet. The test diet produced a PUFA:saturated FA ratio in muscle of 0.4, close to the minimum recommended value for the diet as a whole and an n-6:n-3 ratio of 5, a significant improvement on the current average for pigmeat (7). It is estimated that the test diet would provide 12 g of long chain n-3 PUFA to the human diet per annum at current pigmeat consumption levels in the UK, about a third of that from oily fish.