Allelopathic activity in wheat-conventional and wheat-no-till soils: Development of soil extract bioassays

The primary objective of this research was to determine if soil extracts could be used directly in bioassays for the detection of allelopathic activity. Here we describe: (1) a way to estimate levels of allelopathic compounds in soil; (2) how pH, solute potential, and/or ion content of extracts may modify the action of allelopathic compounds on germination and radicle and hypocotyl length of crimson clover (Trifolium incarnatum L.) and ivyleaved morning glory (Ipomoea hederacea L. Jacquin.); and (3) how biological activity of soil extracts may be determined. A water-autoclave extraction procedure was chosen over the immediate-water and 5-hr EDTA extraction procedures, because the autoclave procedure was effective in extracting solution and reversibly bound ferulic acid as well as phenolic acids from wheat debris. The resulting soil extracts were used directly in germination bioassays. A mixture of phenolic acids similar to that obtained from wheat-no-till soils did not affect germination of clover or morning glory and radicle and hypocotyl length of morning glory. The mixture did, however, reduce radicle and hypocotyl length of clover. Individual phenolic acids also did not inhibit germination, but did reduce radicle and hypocotyl length of both species. 6-MBOA (6-methoxy-2,3-benzoxazolinone), a conversion product of 2-o-glucosyl-7-methoxy-1,4-benzoxazin-3-one, a hydroxamic acid in living wheat plants, inhibited germination and radicle and hypocotyl length of clover and morning glory. 6-MBOA, however, was not detected in wheat debris, stubble, or soil extracts. Total phenolic acids (FC) in extracts were determined with Folin and Ciocalteu's phenol reagent. Levels of FC in wheat-conventionaltill soil extracts were not related to germination or radicle and hypocotyl length of either species. Levels of FC in wheat-no-till soil extracts were also not related to germination of clover or morning glory, but were inversely related to radicle and hypocotyl length of clover and morning glory. FC values, solute potential, and acidity of wheat-no-till soil extracts appeared to be independent (additive) in action on clover radicle and hypocotyl length. Radicle and hypocotyl length of clover was inversely related to increasing FC and solute potential and directly related to decreasing acidity. Biological activity of extracts was determined best from slopes of radicle and hypocotyl length obtained from bioassays of extract dilutions. Thus, data derived from the water-autoclave extraction procedure, FC analysis, and slope analysis for extract activity in conjunction with data on extract pH and solute potential can be used to estimate allelopathic activity of wheat-no-till soilsThe use of trade names in this publication does not imply endorsement by the North Carolina Agricultural Research Service of products named, or criticism of similar ones not mentioned.     

Health risk evaluation associated to Planktothrix rubescens: An integrated approach to design tailored monitoring programs for human exposure to cyanotoxins

Increasing concern for human health related to cyanotoxin exposure imposes the identification of pattern and level of exposure; however, current monitoring programs, based on cyanobacteria cell counts, could be inadequate. An integrated approach has been applied to a small lake in Italy, affected by Planktothrix rubescens blooms, to provide a scientific basis for appropriate monitoring program design. The cyanobacterium dynamic, the lake physicochemical and trophic status, expressed as nutrients concentration and recycling rates due to bacterial activity, the identification/quantification of toxic genotype and cyanotoxin concentration have been studied. Our results indicate that low levels of nutrients are not a marker for low risk of P. rubescens proliferation and confirm that cyanobacterial density solely is not a reliable parameter to assess human exposure. The ratio between toxic/non-toxic cells, and toxin concentrations, which can be better explained by toxic population dynamic, are much more diagnostic, although varying with time and environmental conditions. The toxic fraction within P. rubescens population is generally high (30-100%) and increases with water depth. The ratio toxic/non-toxic cells is lowest during the bloom, suggesting a competitive advantage for non-toxic cells. Therefore, when P. rubescens is the dominant species, it is important to analyze samples below the thermocline, and quantitatively estimate toxic genotype abundance. In addition, the identification of cyanotoxin content and congeners profile, with different toxic potential, are crucial for risk assessment.     

Natural gas distribution in Italy: When competition does not help the market

In this article consequences of the introduction of competition for the field in the Italian natural gas distribution sector are analyzed.Natural gas distribution constitutes, due to its technical and economic features, a natural monopoly. For this reason, in the framework of the liberalization process, the Italian legislator has introduced, in addition to price regulation, competitive tenders in order to have different operators compete amongst each other for the service concession.After a brief overview of the economic theory referring to competition for the field and an overview of the Italian gas market, the critical aspects of the outlined regulatory framework will be highlighted.More particularly the main features of tenders will be assessed, while, in the following section, the meaning of the imposed revenue cap and its tie to the concession fee will be explained. An analysis of possible reasons for extremely high concession fees will be carried out, evaluating their possible impact on companies' profitability. In the last part of the work, a solution will be proposed in order to build an effective regulatory framework in which competition for the field could actually lead the market to efficiency.     

Aripiprazole: Effectiveness and safety under naturalistic conditions.

A retrospective study was conducted to examine aripiprazole's effectiveness and safety in a naturalistic treatment setting in both inpatients and outpatients affected by schizophrenia and other psychotic disorders. All patients with schizophrenia, schizoaffective and delusional disorders, and schizoid and schizotypal personality disorders treated with aripiprazole from March 1, 2005, to March 1, 2006, in the authors' community mental health service were divided into outpatient (n=26) and inpatient (n=17) groups; the average treatment periods were 204 days and 25 days, respectively. Effectiveness was evaluated by improvement of symptoms (a 25% reduction of Brief Psychiatric Rating Scale [BPRS] score from baseline) and functioning level (a 50% increase of Global Assessment of Functioning [GAF] scale score from baseline), as well as dropout rate. Adverse effects and their impact on treatment course were also evaluated. The final scores of the 2 scales showed a statistically significant difference from baseline (BPRS: p     

Transformation of Alumina Inclusions by Calcium Treatment

The objectives of this study were to investigate reactions of calcium with Al₂O₃ by different model experiments both on the laboratory and on the industrial scale. Experiments with solid Al₂O₃ and CaO were performed between 1350 °C and 1600 °C. Reaction rate constants were determined based on scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) observations of reaction products and weight measurements of the Al₂O₃ reacted via dissolution of the CaO bearing phases from the specimens after the annealing period. The results showed that the formation of calcium aluminate phases proceeded rapidly at temperatures greater than 1405 °C when a liquid calcium aluminate was formed. In the lowest temperature range (1350 °C–1405 °C), when the formation of liquid phase ceased, the reaction rate was several orders of magnitude lower. Industrial trials including Ca-alloy injection into steel, sampling and SEM/EDS analyses, as well as an inclusion rating in the samples show the concept of rapid transformation of the alumina inclusions with Ca treatment.     

Addition of Dispersoid Titanium Oxide Inclusions in Steel and Their Influence on Grain Refinement

In this article, the addition of dispersoid titanium oxide inclusions into liquid steel, the effect of additions on the inclusions found in the steel and on grain refinement, and acicular ferrite formation were studied. Different TiO₂-containing materials and addition procedures into liquid steel were tested in experimental heats to obtain inclusions that promote grain refinement and acicular ferrite formation in C-Mn-Cr steel. Different additives with metallic Ti and TiO₂ were added into the steel melt just before casting or into the mold during casting to create Ti-containing inclusions. The aluminum content in steel was lowered by an addition of iron oxide. The samples taken from steel melts and ingots were studied with a scanning electron microscope to find inclusions and to analyze them. Thermodynamic calculations showed that the Al content should be low (<50 ppm) to obtain Ti oxide dominating inclusions, whereas Al₂O₃ were formed at higher Al contents. When TiO₂ was added late before casting, the oxide inclusions were Ti oxides and were mixed with Ti, Al, and Mn oxides. Small inclusions around 1 μm were detected in the samples with TiO _x or TiN as the main component. It could be concluded that the additions resulted in a clearly higher number and in a smaller size of TiO _x inclusions than just by adding metallic Ti. Selected samples were brought for subsequent hot rolling and heat-treatment experiments to find out the grain-refining effect and the eventual formation of acicular ferrite. Grain refinement was observed clearly, but the presence of acicular ferrite could not be confirmed definitely.     

Integrative cognitive therapy for depression: A randomized pilot comparison.

This pilot study examined the efficacy of an integrative form of cognitive therapy (ICT) for depression that incorporates specific strategies for addressing alliance ruptures. Although a previous study on depression found that ICT was superior to a wait-list condition (L. G. Castonguay et al., 2004), the current study provides the 1st direct comparison between ICT and traditional cognitive therapy (CT). Twenty-two depressed adults were randomly assigned to ICT or CT (11 patients per condition), which were delivered by clinicians in training. Outcome was assessed with a specific depression measure and a global symptomatology measure. The groups were also compared on patient-perceived alliance quality and therapist empathy. Effect size estimates revealed that ICT patients evidenced greater posttreatment improvement on both outcome measures (with small to medium effects) and more clinically significant change than did CT patients. ICT patients also had higher alliance and empathy scores across treatment (with medium to large effects). The findings, albeit very preliminary, support the potential viability of ICT and the potential causal influence of the rupture-repair interventions on treatment process and outcome. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A polycationic antimicrobial and biocompatible hydrogel with microbe membrane suctioning ability

Despite advanced sterilization and aseptic techniques, infections associated with medical implants have not been eradicated. Most present coatings cannot simultaneously fulfil the requirements of antibacterial and antifungal activity as well as biocompatibility and reusability. Here, we report an antimicrobial hydrogel based on dimethyldecylammonium chitosan (with high quaternization)-graft-poly(ethylene glycol) methacrylate (DMDC-Q-g-EM) and poly(ethylene glycol) diacrylate, which has excellent antimicrobial efficacy against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Fusarium solani. The proposed mechanism of the antimicrobial activity of the polycationic hydrogel is by attraction of sections of anionic microbial membrane into the internal nanopores of the hydrogel, like an 'anion sponge', leading to microbial membrane disruption and then microbe death. We have also demonstrated a thin uniform adherent coating of the hydrogel by simple ultraviolet immobilization. An animal study shows that DMDC-Q-g-EM hydrogel coating is biocompatible with rabbit conjunctiva and has no toxicity to the epithelial cells or the underlying stroma.     

Survival of Escherichia coli O157:H7 in dry sausage fermented by probiotic lactic acid bacteria

Probiotic Lactobacillus rhamnosus GG, L rhamnosus E‐97800, L rhamnosus LC‐705 and commercial Pediococcus pentosaceus were studied for their ability to inhibit the growth of Escherichia coli O157:H7 in dry sausage. The strains were able to produce technologically high‐quality dry sausage. The number of E coli O157:H7 decreased from approximately 5 to approximately 2 log cfu g⁻¹ It was concluded that the above‐mentioned strains and the commercial culture were equally effective in inhibiting E coli O157:H7. © 2000 Society of Chemical Industry