Light-assisted synthesis of a Ru(VI) nitrido complex by the reaction of azide with a Ru(III) complex

Reaction of Ru(III)(L)(dmf)Cl-3 (1) (L = 4,4,4',4'-tetramethyl-2,2'- bisoxazoline, dmf = N,N-dimethylformamide) with an excess of sodium azide in a methanol-water mixture leads to the isolation of the sodium salt of a Ru( VI) nitrido complex of the tetraanion of N,N'-bis-(2,2-dimethyl-1-hydroxyethyl)-1,2-ethanediamide ( L'H-4; H a dissociable proton) of the formulation Na[Ru(L')(N)(H2O)].1.4H(2)O (2). Complex 2 is not generated in the absence of light. A tentative mechanism for the reaction is proposed and a Ru(IV) intermediate, Na[Ru(L')(N-3)(H2O)] . 2CH(3)OH.2H(2)O (3), isolated.

Accounting information systems as institutional carriers: a case study of regulatory compliance in UK asset management houses

Previously, governments have responded to the impacts of economic failures and consequently have developed more regulations to protect employees, customers, shareholders and the economic wellbeing of the state. Our research addresses how Accounting Information Systems (AIS) may act as carriers for institutionalised practices associated with maintaining regulatory compliance within the context of UK Asset Management Houses. The AIS was found to be a strong conduit for institutionalized compliance related practices, utilising symbolic systems, relational systems, routines and artefacts to carry approaches relating to regulative, normative and cultural-cognitive strands of institutionalism. Thus, AIS are integral to the development and dissipation of best practice for the management of regulatory compliance. As institutional elements are clearly present we argue that AIS and regulatory compliance provide a rich context to further institutionalism. Since AIS may act as conduits for regulatory approaches, both systems adopters and clients may benefit from actively seeking to codify and abstract best practices into AIS. However, the application of generic institutionalized approaches, which may be applied across similar organizations, must be tempered with each firm’s business environment and associated regulatory exposure. A balance should be sought between approaches specific enough to be useful but generic enough to be universally applied.

A tale of two elements: P1ncP1 and RTO

The and RT0 finite element schemes are among the most promising low order elements for use in unstructured mesh marine and lake models. They are both free of spurious elevation modes, have good dispersive properties and have a relatively low computational cost. In this paper, we derive both finite element schemes in the same unified framework and discuss their respective qualities in terms of conservation, consistency, propagation factor and convergence rate. We also highlight the impact that the local variables placement can have on the model solution. The main conclusion that we can draw is that the choice between elements is highly application dependent. We suggest that the element is better suited to purely hydrodynamical applications while the RT0 element might perform better for hydrological applications that require scalar transport calculations.

Distribution and mobility of trace elements in soils and vegetation around the mining and smelting areas of Tharsis, Riotinto and Huelva, Iberian Pyrite Belt, SW Spain

Trace elements may present an environmental hazard in the vicinity of mining and smelting activities. However, the factors controlling their distribution and transfer within the soil and vegetation systems are not always well defined. Total concentrations of up to 15,195 mg center dot kg (-1) As, 6,690 mg center dot kg(-1) Cu, 24,820 mg center dot kg(-1) Pb and 9,810 mg center dot kg(-1) Zn in soils, and 62 mg center dot kg(-1) As, 1,765 mg center dot kg(-1) Cu, 280 mg center dot kg(-1) Pb and 3,460 mg center dot kg (-1) Zn in vegetation were measured. However, unusually for smelters and mines of a similar size, the elevated trace element concentrations in soils were found to be restricted to the immediate vicinity of the mines and smelters (maximum 2-3 km). Parent material, prevailing wind direction, and soil physical and chemical characteristics were found to correlate poorly with the restricted trace element distributions in soils. Hypotheses are given for this unusual distribution: (1) the contaminated soils were removed by erosion or (2) mines and smelters released large heavy particles that could not have been transported long distances. Analyses of the accumulation of trace elements in vegetation (median ratios: As 0.06, Cu 0.19, Pb 0.54 and Zn 1.07) and the percentage of total trace elements being DTPA extractable in soils (median percentages: As 0.06%, Cu 15%, Pb 7% and Zn 4%) indicated higher relative trace element mobility in soils with low total concentrations than in soils with elevated concentrations.

Factors affecting distribution and mobility of trace elements (Cu, Pb, Zn) in a perennial grapevine (Vitis vinifera L.) in the Champagne region of France

Soil and Vitis vinifera L (coarse and fine roots, leaves, berries) concentration and geochemical partitioning of Cu, Pb and Zn were determined in a contaminated calcareous Champagne plot to assess their mobility and transfer. Accumulation ratios in roots remained low (0.1-0.4 for Cu and Zn, <0.05 for Pb). Differences between elements resulted from vegetation uptake strategy and soil partitioning. Copper, significantly associated with the oxidisable fraction (27.8%), and Zn with the acid soluble fraction (33.3%), could be mobilised by rhizosphere acidification and oxidisation, unlike Pb, essentially contained in the reducible fraction (72.4%). Roots should not be considered as a whole since the more reactive fine roots showed higher accumulation ratios than coarse ones. More sensitive response of fine roots, lack of correlation between chemical extraction results and vegetation concentrations, and very limited translocation to aerial parts showed that fine root concentrations should be used when assessing bioavailability. (C) 2008 Elsevier Ltd. All rights reserved.

Isolation of lactoperoxidase using different cation exchange resins by batch and column procedures

Lactoperoxidase (LP) was isolated from whey protein by cation-exchange using Carboxymethyl resin (CM-25C) and Sulphopropyl Toyopearl resin (SP-650C). Both batch and column procedures were employed and the adsorption capacities and extraction efficiencies were compared. The resin bed volume to whey volume ratios were 0.96:1.0 for CM-25C and ≤ 0.64:1.0 for SP-650 indicating higher adsorption capacity of SP-650 compared to CM-25C. The effluent LP activity depended on both the enzyme activity in the whey and the amount of whey loaded on the column within the saturation limits of the resin. The percentage recovery was high below the saturation point and fell off rapidly with over-saturation. While effective recovery was achieved with column extraction procedures, the recovery was poor in batch procedures. The whey-resin contact time had little impact on the enzyme adsorption. SDS PAGE and HPLC analyses were also carried out, the purity was examined and the proteins characterised in terms of molecular weights. Reversed phase HPLC provided clear distinction of the LP and lactoferrin (LF) peaks. The enzyme purity was higher in column effluents compared to batch effluents, judged on the basis of the clarity of the gel bands and the resolved peaks in HPLC chromatograms.

Effect of biotic factors on the isolation of Lupinus albus protoplasts

Several tissue types of Lupinus albus L. were investigated as sources for the isolation of protoplasts. Cotyledons from in vitro seedlings were found to yield the highest number of protoplasts compared with leaves, hypocotyls and roots. A combination of the protoplast isolation enzymes, cellulase and Pectolyase Y23, was capable of releasing the highest number of protoplasts compared with a combination of cellulase and Macerase. Protoplast yield increased with increasing cotyledon age but was accompanied by a progressive decline in protoplast viability. The optimal combination of protoplast yield and viability occurred when the protoplasts were isolated from 14- to 18-day-old cotyledons. The ratio between the volume of enzyme solution and the tissue biomass did not affect the protoplast production significantly. This is the first report of the isolation of protoplasts from a lupin cotyledon and, following the procedure described in this paper, an average yield of 1.2 x 10(6) protoplasts per gram of fresh tissue was obtainable.

The isolation of a single spore isolate of Pasteuria penetrans and its pathogenicity on Meloidogyne javanica

We have obtained a single spore isolate of Pasteuria penetrans, derived by allowing a single spore to attach to a second-stage juvenile (J2) of the root-knot nematode Meloidogyne javanica. By analysing DNA sequences at three different loci we have obtained evidence that the isolate is, indeed, genetically pure. We compared the ability of the single spore isolate and the parent population from which it was selected to attach to and parasitise both the original population of M. javanica on which it was isolated and a single egg mass line derived from it. There was no difference in the attachment of spores of the single spore isolate to juveniles compared to the parental population, although there were higher numbers of both attaching to J2 of the single egg mass line compared to its parental population. Judging from the numbers of egg masses and Pasteuria-infected females, the single spore isolate was less pathogenic to the parental population of M. javanica than was the parental spore population.

Isolation of haloarchaea that grow at low salinities

Archaea, the third domain of life, were long thought to be limited to environmental extremes. However, the discovery of archaeal 16S rRNA gene sequences in water, sediment and soil samples has called into question the notion of Archaea as obligate extremophiles. Until now none of these novel Archaea has been brought into culture, a critical step for discovering their ecological roles. We have cultivated three novel halophilic Archaea (haloarchaea) genotypes from sediments in which the pore-water salinity was close to that of seawater. All previously reported haloarchaeal isolates are obligate extreme halophiles requiring at least 9% w/v NaCl for growth and are typically the dominant heterotrophic organisms in salt and soda lakes, salt deposits and salterns. Two of these three newly isolated genotypes have lower requirements for salt than previously cultured haloarchaea and are capable of slow growth at seawater salinity (2.5% w/v NaCl). Our data reveal the existence of Archaea that can grow in non-extreme conditions and of a diverse community of haloarchaea existing in coastal salt marsh sediments. Our findings suggest that the ecological range of these physiologically versatile prokaryotes is much wider than previously supposed.

Effect of biotic factors on the isolation of Lupinus albus L. protoplasts

Several tissue types of Lupinus albus L. were investigated as sources for the isolation of protoplasts. Cotyledons from in vitro seedlings were found to yield the highest number of protoplasts compared with leaves, hypocotyls and roots. A combination of the protoplast isolation enzymes, cellulase and Pectolyase Y23, was capable of releasing the highest number of protoplasts compared with a combination of cellulase and Macerase. Protoplast yield increased with increasing cotyledon age but was accompanied by a progressive decline in protoplast viability. The optimal combination of protoplast yield and viability occurred when the protoplasts were isolated from 14- to 18-day-old cotyledons. The ratio between the volume of enzyme solution and the tissue biomass did not affect the protoplast production significantly. This is the first report of the isolation of protoplasts from a lupin cotyledon and, following the procedure described in this paper, an average yield of 1.2 × 106 protoplasts per gram of fresh tissue was obtainable.

Solvent-Assisted Formation of Vesicles by a Self-Assembling Ni-3-Schiff Base Complex

A linear trinuclear Ni-Schiff base complex [Ni-3(salpen)(2)(PhCH2COO)(2)(EtOH)] has been synthesized by combining Ni(ClO4)(2)center dot 6H(2)O, phenyl acetic acid (C6H5CH2COOH), and the Schiff base ligand, N,N'-bis(salicylidene)-1,3-pentanediamine (H(2)salpen). This complex is self-assembled through hydrogen bonding and C-H-g interaction in the solid state to generate a sheet-like architecture, while in organic solvent (CH2Cl2), it forms vesicles with a mean diameter of 290 nm and fused vesicles, depending upon the concentration of the solution. These vesicles act as an excellent carrier of dye molecules in CH2Cl2. The morphology of the complex has been determined by scanning electron microscopy and transmission electron microscopy experiments, and the encapsulation of dye has been examined by confocal microscopic image and electronic absorption spectra.

Structure dependent rearrangement of the cyclopropylmethyl cation - isolation of a bicyclo[3.2.0]heptene

Access to 7-allyl substituted norbornene derivatives for tandem olefin metathesis via cationic rearrangement of cyclopropylmethanol substituted norbornenes is shown to be structure dependent. In some cases products that arise from cationic rearrangement of a cyclopropylmethyl cation are furnished. Thionyl chloride is shown to be superior to silica for inducing the desired rearrangement. (c) 2007 Elsevier Ltd. All rights reserved.

An in vitro assessment of the effects of broad-spectrum antibiotics on the human gut microflora and concomitant isolation of a Lactobacillus plantarum with anti-Candida activities

Chemostat culture was used to determine the effects of the antimicrobial agents tetracycline and nystatin on predominant components of the human gut microflora. Their addition to mixed culture systems caused a non-specific, and variable, decrease in microbial populations, although tetracycline allowed an increase in numbers of yeasts. Both had a profound inhibitory effect upon populations seen as important for gut health (bifidobacteria, lactobacilli). However, a tetracycline resistant Lactobacillus was enriched from the experiments. A combination of genotypic and phenotypic characterisations confirmed its identity as Lactobacillus plantarum. This strain exerted powerful inhibitory effects against Candida albicans. Because of its ability to resist the effects of tetracycline, this organism may be useful as a probiotic for the improved management of yeast related conditions such as thrush and irritable bowel syndrome. (C) 2004 Elsevier Ltd. All rights reserved.

Isolation of culturable yeasts from market wines and evaluation of the 5 center dot 8S-ITS rDNA sequence analysis for identification purposes

Aims: To test the possibility that wines available in the marketplace may contain culturable yeasts and to evaluate the 5.8S-ITS rDNA sequence analysis as adequate means for the identification of isolates. Methods and Results: As a case study, typical Greek wines were surveyed. Sequence analysis of the 5.8S-ITS rDNA was tested for its robustness in species or strain identification. Sixteen isolates could be assigned into the species Brettanomyces bruxellensis, Saccharomyces cerevisiae and Rhodotorula pinicola, whereas four isolates could not be safely identified. B. bruxellensis was the dominant species present in house wines, while non-Saccharomyces sp. were viable in aged wines of high alcohol content. Conclusions: Yeast population depends on postfermentation procedures or storage conditions. Although 5.8S-ITS rDNA sequence analysis is generally a rapid method to identify wine yeast isolates at the species level, or even below that, it may not be sufficient for some genera. Significance and Impact of the Study: This is the first report to show that commercial wines may possess diverse and potentially harmful yeast populations. The knowledge of yeasts able to reside in this niche environment is essential towards integrated quality assurance programmes. For selected species, the 5.8S-ITS rDNA sequence analysis is a rapid and accurate means.

Isolation of Corynebacterium falsenii and description of Corynebacterium aquilae sp. nov., from eagles

Biochemical, molecular chemical and molecular genetic studies were performed on seven unidentified Gram-positive, rod-shaped organisms recovered from eagles. The strains were provisionally identified as Corynebacterium jeikeium with the commercial API Coryne system, but they were able to grow under anaerobic conditions and were non-lipophilic. Comparative 16S rRNA gene sequencing studies demonstrated that the isolates belonged phylogenetically to the genus Corynebacterium. Three strains were identified genotypically as Corynebacterium falsenii; the remaining four strains corresponded to a hitherto unknown lineage within the genus Corynebacterium, associated with a small subcluster of species that included Corynebacterium diphtheriae and its close relatives. The unknown bacterial strains were readily distinguished from these and other species of the genus by biochemical tests. Based on both phenotypic and phylogenetic evidence, it is proposed that the unknown bacterial strains from eagles should be classified as Corynebacterium aquilae sp. nov. (type strain is S-613(T)=CECT 5993(T)=CCUG 46511(T)).