1,370 research outputs found
Evaluation of the users value of salts against apple scab and powdery mildew for fruit production
The research was aimed at finding anti resistance strategies for Integrated fruit growing.
As the salts tested may be approvable for organic farming, the trial results are also of
value for the development of scab an mildew control strategies for organic fruit growing. As
new fungicides are mainly unisite action fungicides, the problem of fungicide resistance
development is becoming more important every year. Combining chemical fungicides,
which is the best anti-resistance strategy, is not always possible or recommended in the
case when the number of available chemical fungicides are limited or a reduction in
fungicide use is asked for. Therefore the use of salts as an anti-resistance strategy was
looked upon. The salts evaluated were K(HCO3), KH2PO3, KHPO4 and K2SiO3. When
using these salts as an anti-resistance strategy the efficacy obtained when spraying the
compounds alone was often to low to be used in rotation with chemical fungicides. Only
with K(HCO3)2 a good efficacy can be observed in some years. The variation in efficacy
with K(HCO3)2 observed is higher for powdery mildew. K(HCO3)2 can be considered as a
ideal product for scab control in organic orchards at moments of low infection risk
Improving control of storage diseases on apple by combining biological and physical post-harvest methods
Post-harvest non-chemical treatments consists of a large range of different approaches,
including strengthening of the commodity’s natural defence mechanisms, thermotherapy,
application of antagonistic microorganisms and natural antimicrobial substances.
NEX0101 is a promising antagonistic biocontrol agent containing the yeast Candida
oleophila as the active ingredient. NEX0101 was developed by Bionext, a spin-off from the
laboratory of Dr. H. Jijakli, and is currently evaluated for commercial use. The product
contains a yeast strain isolated from apple fruit and was originally developed for the control
of post-harvest diseases on apple. The antifungal effectiveness of this antagonist can be
increased by addition of calcium salts. As the mode of action of this yeast is based on the
colonisation of wounds, the mean targets of NEX0101 are blue mould, caused by
Penicillium expansum, and grey mould, caused by Botrytis cinerea. Facing possible latent
infections, thermotherapy by using hot water treatments could provide an advanced control
towards lenticelrot (Gloeosporium spp.). A combination of both physical and biological
treatment techniques could broaden the spectrum to all key pathogens on apple and pear.
The use of NEX0101 for the control of P. expansum was examined in combination with
calcium gluconate. According to the results the combination NEX0101 with calcium
gluconate provides an advanced mould control towards P. expansum The best results
were achieved using NEX0101 in combination with post-harvest dipping by thermotherapy.
The hot water treatment alone was clearly inefficient towards wound parasite P.
expansum, on the contrary thermotherapy stimulates the decay caused by this postharvest
pathogen. For the future a combination of biological and physical treatments could offer a
worthy non-chemical alternative for organic and integrated fruit growers towards fruit rot
decay, although more research is necessary to implement these methods in practice
Proliferation Sensitivity of Dual Use Equipment for Laser Isotope Separation
The international nuclear security is strengthened by explicit import/export control of dual-use equipment. This paper reports on a methodology applying Fault Tree Analysis (FTA) to enhance this control by detecting changes in import behaviour. The methodology is applied to the import of a combination of components that might be used for the construction of Laser Isotope Separation (LIS)plants. The critical components that are necessary for the construction of a LIS plant are determined and implemented in a Tree structure. The fractions of the critical components’ export to the total export are converted to probabilities, which are inserted in the constructed Tree. The Tree is analysed by the Fault Tree Analyser ASTRA that calculates the Top Event probability, Minimal Cut Sets (MCS) and the Criticality Index. The latter is interpreted as a deviation in import behaviour of a given nation for sensitive components. The evolution in time of the Top Event probability is obtained by analyzing real data from five year periods, in seven subsequent time frames,starting with the period 1995-1999 towards the final period 2001-2005. This technique provides a powerful tool to re–analyse import statistics by evaluating the change in import of a combination of sensitive components. It is found that five year periods show a meaningful evolution of the Top Event probability and are a good estimate. However, the five year time frame conditions the analysis of the change in infrastructure and equipment with potential use for laser enrichment. Advanced versions of this probabilistic method may provide customs services with an effective tool that is of potential use for detecting anomalies in import behaviour of LIS or other sensitive technologies
Spectral hole buRNing and fluorescence line narrowing in subunits of the light-harvesting complex LH1 of purple bacteria
Hypoxia in atherogenesis
The anoxemia theory proposes that an imbalance between the demand for and supply of oxygen in the arterial wall is a key factor in the development of atherosclerosis. There is now substantial evidence that there are regions within the atherosclerotic plaque in which profound hypoxia exists; this may fundamentally change the function, metabolism, and responses of many of the cell types found within the developing plaque and whether the plaque will evolve into a stable or unstable phenotype. Hypoxia is characterized in molecular terms by the stabilization of hypoxia-inducible factor (HIF) 1a, a subunit of the heterodimeric nuclear transcriptional factor HIF-1 and a master regulator of oxygen homeostasis. The expression of HIF-1 is localized to perivascular tissues, inflammatory macrophages, and smooth muscle cells adjacent to the necrotic core of atherosclerotic lesions and regulates several genes that are important to vascular function including vascular endothelial growth factor, nitric oxide synthase, endothelin-1, and erythropoietin. This review summarizes the effects of hypoxia on the functions of cells involved in atherogenesis and the evidence for its potential importance from experimental models and clinical studies
Heterozygous Mutations Causing Partial Prohormone Convertase 1 Deficiency Contribute to Human Obesity
A large geometric distortion in the first photointermediate of rhodopsin, determined by double-quantum solid-state NMR
Double-quantum magic-angle-spinning NMR experiments were performed on 11,12-C-13(2)-retinylidene-rhodopsin under illumination at low temperature, in order to characterize torsional angle changes at the C11-C12 photoisomerization site. The sample was illuminated in the NMR rotor at low temperature (similar to 120 K) in order to trap the primary photointermediate, bathorhodopsin. The NMR data are consistent with a strong torsional twist of the HCCH moiety at the isomerization site. Although the HCCH torsional twist was determined to be at least 40A degrees, it was not possible to quantify it more closely. The presence of a strong twist is in agreement with previous Raman observations. The energetic implications of this geometric distortion are discussed
Improved Non-Pt Alloys for the Oxygen Reduction Reaction at Fuel Cell Cathodes Predicted from Quantum Mechanics
Based on studies on Pt_3Co and Pt_3Ni, we developed the hypothesis that improved alloy catalysts for the oxygen reduction reaction (ORR) at fuel cell cathodes should have a surface layer that is noble (e.g., Pt, Pd, or Rh) while the second layer should have ~50% electropositive metal to decrease the critical barriers for ORR, and we used quantum mechanics (QM) to examine 80 binary alloys of composition Y_3X, where Y = Pt, Pd, Rh, and X is any of the three rows of transition metals (columns 3−11). This study identified that for Pd_3X, good segregating alloys include X = Re (best), W, Os, Mo, Ru, Ir, Tc, Rh, Co, Ta, Nb, and Ni. Of these we selected Pd_3W as particularly promising since it is known experimentally to form an ordered alloy and was found to have a desirable d-band center. We then examined the critical barriers for various steps of the ORR with Pd_3W and compared them to the analogous barriers for Pt, Pt_3Co, and Pd. These results suggest that Pd_3W will exhibit ORR properties dramatically improved over pure Pd and close to that of pure Pt. The cost of Pd_3W is ~6 times less than pure Pt, suggesting that Pd_3W catalysts might lead to significant decreases in catalyst cost, while maintaining performance
In gas laser ionization and spectroscopy experiments at the Superconducting Separator Spectrometer (S3): Conceptual studies and preliminary design
International audienceThe results of preparatory experiments and the preliminary designs of a new in-gas laser ionization and spectroscopy setup, to be coupled to the Super Separator Spectrometer S3 of SPIRAL2-GANIL, are reported. Special attention is given to the development and tests to carry out a full implementation of the in-gas jet laser spectroscopy technique. Application of this novel technique to radioactive species will allow highsensitivity and enhanced-resolution laser spectroscopy studies of ground- and excited-state properties of exotic nuclei
A novel role for syndecan-3 in angiogenesis.
Syndecan-3 is one of the four members of the syndecan family of heparan sulphate proteoglycans and has been shown to interact with numerous growth factors via its heparan sulphate chains. The extracellular core proteins of syndecan-1,-2 and -4 all possess adhesion regulatory motifs and we hypothesized that syndecan-3 may also possess such characteristics. Here we show that a bacterially expressed GST fusion protein consisting of the entire mature syndecan-3 ectodomain has anti-angiogenic properties and acts via modulating endothelial cell migration. This work identifies syndecan-3 as a possible therapeutic target for anti-angiogenic therapy.This work was funded by Arthritis Research-UK (Grant No. 19207) and funds from the William Harvey Research Foundation both to JRW
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