Vibration and two-photon absorption

The rigorous and transparent treatment of the effects of nuclear vibrational motion in two-photon absorption (TPA) was discussed. Perturbation formula for diatomic molecules were developed and applied to the X¹Σ+–A¹Π transition in CO. The analysis showed that the vibrations played an important role in TPA, just as their role in the calculation of conventional nonlinear optical (NLO) hyperpolarizabilities

Biosensor-based diagnostics of contaminated groundwater: assessment and remediation strategy

Shallow groundwater beneath a former airfield site in southern England has been heavily contaminated with a wide range of chlorinated solvents. The feasibility of using bacterial biosensors to complement chemical analysis and enable cost-effective, and focussed sampling has been assessed as part of a site evaluation programme. Five different biosensors, three metabolic (Vibrio fischeri, Pseudomonas fluorescens 10568 and Escherichia coli HB101) and two catabolic (Pseudomonas putida TVA8 and E. coli DH5alpha), were employed to identify areas where the availability and toxicity of pollutants is of most immediate environmental concern. The biosensors used showed different sensitivities to each other and to the groundwater samples tested. There was generally a good agreement with chemical analyses. The potential efficacy of remediation strategies was explored by coupling sample manipulation to biosensor tests. Manipulation involved sparging and charcoal treatment procedures to simulate remediative engineering solutions. Sparging was sufficient at most locations. (C) 2004 Elsevier Ltd. All rights reserved.

Localization of eIF4A-III in the nucleolus and splicing speckles is an indicator of plant stress

The mechanisms of long-term adaptation to low oxygen environment are quite well studied, but little is known about the sensing of oxygen shortage, the signal transduction and the short-term effects of hypoxia in plant cells. We have found that an RNA helicase eIF4A-III, a putative component of the Exon Junction Complex, rapidly changes its pattern of localisation in the plant nucleus under hypoxic conditions. In normal cell growth conditions GFP- eIF4A-III was mainly nucleoplasmic, but in hypoxia stress conditions it moved to the nucleolus and splicing speckles. This transition occurred within 15-20 min in Arabidopsis culture cells and seedling root cells, but took more than 2 h in tobacco BY-2 culture cells. Inhibition of respiration, transcription or phosphorylation in cells and ethanol treatment had similar effects to hypoxia. The most likely consequence is that a certain mRNA population will remain bound to the eIF4A-III and other mRNA processing proteins, rather than being transported from the nucleus to the cytoplasm, and thus its translation will be suspended.

Recovery of nitrogen from different sources following applications to winter wheat at and after anthesis

The effects of applying nitrogen (30 or 40 kg N/ha) to wheat crops at and after anthesis, after 200 kg N/ha had already been applied to the soil during stem extension, were studied in field experiments comprising complete factorial combinations of different cultivars, fungicide applications and nitrogen treatments. Actual recoveries of late-season fertilizer nitrogen (LSFN), as indicated by N-15 studies, interacted with cultivar and fungicide treatment, and depended on nitrogen source (Urea applied as a solution to the foliage, or as ammonium nitrate applied to the soil) and year. These interactions, however, were not reflected in apparent fertilizer recoveries ((N in grain with LSFN - N in grain without LSFN)/N applied as LSFN), or in the crude protein concentration. Apparent fertilizer recovery was always lower than actual recoveries, and declined during grain filling. Fertilizer treatments with higher actual fertilizer recoveries were associated with lower net renlobilisation of non-LSFN (net remobilised N = N in above ground crop at anthesis - N in non-grain, above ground crop at harvest). LSFN also increased mineral nitrogen in the soil at harvest even when applied as a solution to the foliage. These effects are discussed in relation to potential grain N demand. (c) 2006 Elsevier B.V. All rights reserved.

The potential of combining Pasteuria penetrans and neem (Azadirachta indica) formulations as a management system for root-knot nematodes on tomato

Initial applications of 10(4) spores g(-1) of Pasteuria penetrans, and dried neem cake and leaves at 3 and 2% w:w, respectively, were applied to soil in pots. Juveniles of Meloidogyne javanica were added immediately to the pots (500, 5,000 or 10,000) before planting 6-week-old tomato seedlings. The tomatoes were sampled after 64 days; subsequently a second crop was grown for 59 days and a third crop for 67 days without further applications of P. penetrans and neem. There was significantly less root-galling in the P. penetrans combined with neem cake treatment at the end of the third crop and this treatment also had the greatest effect on the growth of the tomato plants. At the end of the third crop, 30% of the females were infected with P. penetrans in those treatments where spores had been applied at the start of the experiment. The effects of neem leaves and neem cake on the nematode population did not persist through the crop sequences but the potential for combining the amendments with a biological control agent such as P. penetrans is worthy of further evaluation.

Root pruning as a means to encourage root growth in two ornamental shrubs, Buddleja davidii ‘Summer Beauty’ and Cistus ‘Snow Fire'

The inability of a plant to grow roots rapidly upon transplanting is one of the main factors contributing to poor establishment. In bare-rooted trees, treatments such as root pruning or application of the plant hormone auxin [e.g., indole butyric acid (IBA)] can promote root growth and aid long-term establishment. There is little information on ornamental containerised plants, however, other than the anecdotal notion that 'teasing' the roots out of the rootsoil mass before transplanting can be beneficial. In the present study we tested the ability of various root-pruning treatments and application of IBA to encourage new root and shoot growth in two shrub species, commonly produced in containers - Buddleja davidii 'Summer Beauty' and Cistus 'Snow Fire'. In a number of experiments, young plants were exposed to root manipulation (teasing, light pruning, or two types of heavy pruning) and/or treatment with IBA (at 500 or 1,000 mg l-1) before being transplanted into larger containers containing a medium of 1:1:1 (v/v/v) fine bark, sand and loam. Leaf stomatal conductance (gl) was measured 20 min, and 1, 2, 4 and 6 h after root manipulation. Net leaf CO2 assimilation (A) was measured frequently during the first week after transplanting, then at regular intervals up to 8 weeks after transplanting. Plants were harvested 8 weeks after transplanting, and root and shoot weights were measured. In both species, light root pruning alone, or in combination with 500 mg l-1 IBA, was most effective in stimulating root growth. In contrast, teasing, which is commonly used, showed no positive effect on root growth in Buddleja, and decreased new root growth in Cistus. The requirement for exogenous auxin to encourage new root growth varied between experiments and appeared to be influenced by the age and developmental stage of the plants. There were no consistent responses between root treatments and net CO2 assimilation rates, and changes in root weight were not closely correlated with changes in assimilation. The mechanisms whereby new root growth is sustained are discussed.

Vertical distribution, size and composition of the weed seedbank under various tillage and herbicide treatments in a sequence of industrial crops

Investigations were conducted during the 2003, 2004 and 2005 growing seasons in northern Greece to evaluate effects of tillage regime (mouldboard plough, chisel plough and rotary tiller), cropping sequence (continuous cotton, cotton-sugar beet rotation and continuous tobacco) and herbicide treatment on weed seedbank dynamics. Amaranthus spp. and Portulaca oleracea were the most abundant species, ranging from 76% to 89% of total weed seeds found in 0-15 and 15-30 cm soil depths during the 3 years. With the mouldboard plough, 48% and 52% of the weed seedbank was found in the 0-15 and 15-30 cm soil horizons, while approximately 60% was concentrated in the upper 15 cm soil horizon for chisel plough and rotary tillage. Mouldboard ploughing significantly buried more Echinochloa crus-galli seeds in the 15-30 cm soil horizon compared with the other tillage regimes. Total seedbank (0-30 cm) of P. oleracea was significantly reduced in cotton-sugar beet rotation compared with cotton and tobacco monocultures, while the opposite occurred for E. crus-galli. Total seed densities of most annual broad-leaved weed species (Amaranthus spp., P. oleracea, Solanum nigrum) and E. crus-galli were lower in herbicide treated than in untreated plots. The results suggest that in light textured soils, conventional tillage with herbicide use gradually reduces seed density of small seeded weed species in the top 15 cm over several years. In contrast, crop rotation with the early established sugar beet favours spring-germinating grass weed species, but also prevents establishment of summer-germinating weed species by the early developing crop canopy.

Incorporation of in situ and biomarker assays in higher-tier assessment of the aquatic toxicity of insecticides

This study was designed to test the feasibility of integrating in situ, single species exposures and biomarker analysis into microcosm studies. Experimental ponds were dosed with pirimiphos methyl (PM) and lindane. C. riparius fourth instar larvae were deployed for 48 h on nine separate occasions during the study period before and after treatment. Surviving larvae were analysed for acetylcholinesterase activity (AChE). Survival and biomarker data were compared to chironomid assemblage analysis by monitoring insects emerging from the microcosms. Survival of chironomids within the in situ systems commenced on day + 16 after treatment with 31.6% and 53.3% survival in the lindane and PM treated ponds, respectively. In contrast, the first emergence from the microcosms occurred on days + 27, in respect to lindane, and + 59 for the PM treated ponds. Thus the in situ bioassay was able to demonstrate gradual reduction in toxicity within the sediment before this was evident from macroinvertebrate monitoring. Significant ACNE inhibition was only detected on exposure to PM. Levels decreased from 75% on day + 16 to 26% by day +29. The biomarker analysis confirmed that, by the end of the study, the insecticide was no longer exerting an effect. We discuss how the use of in situ bioassays could also aid comparison of microcosm studies by adding a standardized dimension. (C) 2003 Elsevier Ltd. All rights reserved.

Relationship between sublethal injury and microbial inactivation by the combination of high hydrostatic pressure and citral or tert-butyl hydroquinone

The aim was to investigate (i) the occurrence of sublethal injury in Listeria monocytogenes, Escherichia coli, and Saccharomyces cerevisiae after high hydrostatic pressure (HHP) treatment as a function of the treatment medium pH and composition and (ii) the relationship between the occurrence of sublethal injury and the inactivating effect of a combination of HHP and two antimicrobial compounds, tert-butyl hydroquinone (TBHQ) and citral. The three microorganisms showed a high proportion of sublethally injured cells (up to 99.99% of the surviving population) after HHP. In E. coli and L. monocytogenes, the extent of inactivation and sublethal injury depended on the pH and the composition of the treatment medium, whereas in S. cerevisiae, inactivation and sublethal injury were independent of medium pH or composition under the conditions tested. TBHQ alone was not lethal to E. coli or L. monocytogenes but acted synergistically with HHP and 24-h refrigeration, resulting in a viability decrease of >5 log(10) cycles of both organisms. The antimicrobial effect of citral depended on the microorganism and the treatment medium pH. Acting alone for 24 h under refrigeration, 1,000 ppm of citral caused a reduction of 5 log(10) cycles of E. coli at pH 7.0 and almost 3 log(10) cycles of L. monocytogenes at pH 4.0. The combination of citral and HHP also showed a synergistic effect. Our results have confirmed that the detection of sublethal injury after HHP may contribute to the identification of those treatment conditions under which HHP may act synergistically with other preserving processes.

Bioactive peptides from food proteins: new opportunities and challenges

Food proteins such as milk and soy are a rich source of bioactive peptides. In the last decade, research into this area has intensified and new bioactive peptide sequences have been discovered with a range of apparent biological functions; for example, antihypertensive, antioxidant, and antimicrobial effects and opiate-like qualities have been reported. These peptides could therefore lead to the development of important functional food products and ingredients for the prevention and even treatment of chronic diseases such as cardiovascular disease and cancer. Peptides can be produced by fermentation with dairy starters for instance, and by enzymatic hydrolysis with pancreatic and microbial enzymes. Further purification is typically carried out by membrane filtration and/or chromatographic methods. The production of novel bioactive peptides and their incorporation into functional food products poses several technological challenges as well as regulatory and marketing issues. Proof of efficacy is of paramount importance; this should be verified by conducting appropriate tests in vivo in animals and in humans. In addition, tests for cytotoxicity and allergenicity must be conducted. Despite all of these hurdles, scientific evidence is increasingly demonstrating the health benefits of diet-based disease prevention, and therefore new developments in this area are likely to continue both at the research and the commercialisation level.

Genistein affects the expression of genes involved in blood pressure regulation and angiogenesis in primary human endothelial cells

Background: Several lines of evidence suggest that the dietary isoflavone genistein (Gen) has beneficial effects with regard to cardiovascular disease and in particular on aspects related to blood pressure and angiogenesis. The biological action of Gen may be, at Least in part, attributed to its ability to affect cell signalling and response. However, so far, most of the molecular mechanisms underlying the activity of Gen in the endothelium are unknown. Methods and results: To examine the transcriptional response to 2.5 mu M Gen on primary human endothelial cells (HUVEC), we applied cDNA array technology both under baseline condition and after treatment with the pro-atherogenic stimulus, copper-oxidized LDL. The alteration of the expression patterns of individual transcripts was substantiated using either RT-PCR or Northern blotting. Gen significantly affected the expression of genes encoding for proteins centrally involved in the vascular tone such as endothelin-converting enzyme-1, endothetin-2, estrogen related receptor a and atria[ natriuretic peptide receptor A precursor. Furthermore, Gen countered the effect of oxLDL on mRNA levels encoding for vascular endothelial growth factor receptor 165, types 1 and 2. Conclusions: Our data indicate that physiologically achievable levels of Gen change the expression of mRNA encoding for proteins involved in the control of blood pressure under baseline conditions and reduce the angiogenic response to oxLDL in the endothelium. (c) 2005 Elsevier B.V. All rights reserved.

Characterisation of blends based on hydroxyethylcellulose and maleic acid-alt-methyl vinyl ether

Hydrophilic polymeric films based on blends of hydroxyethylcellulose and maleic acid-co-methyl vinyl ether were produced by casting from aqueous solutions. The physicochemical properties of the blends have been assessed using Fourier transform infrared spectroscopy, thermal gravimetric analysis, differential scanning calorimetry, dielectric spectroscopy, etc. The pristine films exhibit complete miscibility due to the formation of intermacromolecular hydrogen bonding. The thermal treatment of the blend films leads to cross-linking via intermacromolecular esterification and anhydride formation. The cross-linked materials are able to swell in water and their swelling degree can be easily controlled by temperature and thermal treatment time. The formation of the crosslinks is apparent in the dynamic properties of the blends as observed through the mechanical relaxation and dielectric relaxation spectra. The dielectric characteristics of the material are influenced by the effects of change in the local structure of the blend on the ionic conduction processes and the rate of dipolar relaxation. Separation of these processes is attempted using the dielectric modulus method. Significant deviations from a simple additive rule of mixing on the activation energy are observed consistent with hydrogen bonding and crosslinking of the matrix. This paper indicates a method for the creation of films with good mechanical and physical characteristics by exposing the blends to a relatively mild thermal treatment.

The co-occurrence of autism and Williams syndrome: a case study report

This paper describes a longitudinal case study detailing the communication profile of one child with both Williams syndrome (WS) and autism. The participant was administered two standardized assessments of language and general cognitive abilities. His parents completed the Pre-Verbal Communication Schedule; and a sample of the child's spontaneous interaction was analyzed. The results show that this child presents with markedly delayed language and communication skills and that his communication profile is the opposite of the assumed 'typical' WS profile. The conclusion is that clinicians need to be aware of the co-occurrence of genetic disorders, such as WS and autism in order to facilitate accurate diagnosis and effective treatment.

Treatment response in child anxiety is differentially related to the form of maternal anxiety disorder

An examination was made of the extent to which maternal anxiety predicted response to treatment of children presenting with an anxiety disorder. In a sample of 55 children referred to a local NHS CAMH service for treatment of an anxiety disorder, systematic mental state interview assessment was made of both mothers and children, and both completed self-report questionnaires to assess aspects of anxiety, both immediately before the children received treatment and following treatment. Children of mothers with anxiety disorder overall responded less well to treatment than children of mothers with no anxiety disorder. There was some diagnostic specificity in this in that children of mothers with GAD did as well in treatment as children whose mothers had no anxiety, whereas children of mothers with social phobia did poorly. The outcome for children with anxiety appears to be related to the presence and nature of maternal anxiety. It would seem prudent that treatment of children with anxiety involves assessment of maternal anxiety. It is important to establish in systematic investigation whether treatment of maternal anxiety improves the outcome for child anxiety.

What does a transdiagnostic approach have to offer the treatment of anxiety disorders?

Purpose: The purpose of this paper is to review the rationale for 'transdiagnostic' approaches to the understanding and treatment of anxiety disorders. Methods: Databases searches and examination of the reference lists of relevant studies were used to identify papers of relevance. Results: There is increasing recognition that diagnosis-specific interventions for single anxiety-disorders are of less value than might appear since a large proportion of patients have more than one co-existing anxiety disorder and the treatment of one anxiety disorder does not necessarily lead to the resolution of others. As transdiagnostic approaches have the potential to address multiple co-existing anxiety disorders they are potentially more clinically relevant than single anxiety disorder interventions. They may also have advantages in ease of dissemination and in treating anxiety disorder not otherwise specified. Conclusions: The merits of the various transdiagnostic cognitive-behavioral approaches that have been proposed are reviewed. Such approaches have potential benefits, particularly in striking the balance between completely idiosyncratic formulations and diagnosis-driven treatments of anxiety disorders. However, caution is needed to ensure that transdiagnostic theories and treatments benefit from progress made by research on diagnosis-specific treatments, and further empirical work is needed to identify the shared maintaining processes that need to be targeted in the treatment of anxiety disorders.