768 research outputs found

    Prospects for a successful rape crop

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    Since the disastrous 1972 season, when blackleg disease reached epidemic proportions, rapeseed production has declined dramatically. With attractive prices for rapeseed in prospect many farmers may be trying this crop again. If the risk of loss from blackleg could be assessed early in the season it would assist in deciding whether rape would be an economic proposition

    Extended survival of Puccinia graminis f. sp. tritici urediniospores: implications for biosecurity and on-farm management

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    Puccinia graminis f. sp. tritici (Pgt), the causal organism of stem rust, is of global importance across wheat-growing countries. However, some epidemics commence without the obvious presence of ‘alternate’ or ‘green bridge’ hosts, suggesting urediniospores can survive in the absence of suitable host plants for many weeks. Testing a range of inert material types, including metals, plastics, fabrics and woods, highlighted a significant effect of material type and temperature on urediniospore viability (P < 0.001), with urediniospores remaining attached and viable on these materials (aluminium, paper, rubber, all fabric and all woods) for up to 365 days at 23/8 °C day/night. At 36/14 °C day/night, urediniospore viability was retained for a maximum of 300 days on denim and jute. Furthermore, at 45/15 °C day/night, urediniospores remained viable for a maximum of 180 days on cotton and jute. The frequency of recovery of attached urediniospores was also dependent upon the material type, with significant differences between materials in their abilities to retain urediniospores after washing (P < 0.001). Urediniospores recovered even after 300 or 365 days from the lower two temperature regimes successfully initiated infections of wheat seedlings. Results confirm the potential importance of inert materials as long-term carriers of viable Pgt urediniospores, highlighting risks of spread of new pathotypes and strains across wheat-growing regions, the significant biosecurity implications for contaminated carrier materials, and its likely survival across seasons without a host

    Long-term viability of the northern anthracnose pathogen, Kabatiella caulivora, facilitates its transportation and spread

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    The conidia and resting hyphae of the northern anthracnose pathogen of Trifolium species, Kabatiella caulivora, were effectively carried by, and maintained long-term viability on, a range of materials, including metals, fabrics, woods and plastics. Conidia and hyphae became thick-walled and melanized with time. There were significant (P < 0.001) differences in conidia/resting hyphae survival between carrier materials and between temperature regimes. At 23 °C/8 °C day/night, conidia and resting hyphae remained viable on steel, corrugated iron, galvanized steel, all tested fabrics, wood and random mixed materials for up to 8 months. At 36 °C/14 °C day/night, conidia and resting hyphae remained viable for up to 8 months, but only on cotton, denim, fleece, silk, leather, paper, plastic and all wood materials. At 45 °C/15 °C day/night, conidia and resting hyphae remained viable up to 8 months only on fleece wool, Eucalyptus marginata (jarrah wood) and paper. There were significant differences between carrier materials in their abilities to retain conidia and resting hyphae after washing (P < 0.001). Metabolic activity was confirmed for conidia and resting hyphae recovered after 8 months and K. caulivora colonies successfully re-established on potato dextrose agar. Findings confirmed the critical importance of materials as long-term carriers of viable K. caulivora conidia and resting hyphae, highlighting the potential for spread of a highly virulent K. caulivora race within and outside Australia via farming equipment, clothing and other associated materials. Results also have wider biosecurity implications for the transportation of fungal-infested carrier materials previously considered as low risk

    Exotic fungal spores in the Australian Plant Biosecurity context

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    This project aims to define the relative likelihood of, and means by which, exotic fungal spore incursions on or in different carrier materials can occur by assessing common pathogen species in Australia and likely entry pathways and develop effective methods of decontamination of such infested materials. In Australia, the risk of inadvertent introduction of exotic fungal pathogen particularly by spores is increasing. Many of these exotic fungal pathogens pose a threat to our agricultural, horticultural and natural ecosystems if introduced into Australia e.g. Ug99. This research will improve the current understanding of the different entry pathways of fungal pathogens to Australia. The research project will specifically focus on the role of different materials as fungal spore carriers and their effects on spore survivability using common fungal spores as a model to develop and apply prototype tools to detect the contamination of carrier materials with exotic fungal pathogen threats, and develop effective methods of decontamination of such contaminated materials

    Relevance of the Lin's and Host hydropedological models to predict grape yield and wine quality

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    The adoption of precision agriculture in viticulture could be greatly enhanced by the diffusion of straightforward and easy to be applied hydropedological models, able to predict the spatial variability of available soil water. The Lin's and Host hydropedological models were applied to standard soil series descriptions and hillslope position, to predict the distribution of hydrological functional units in two vineyard and their relevance for grape yield and wine quality. A three-years trial was carried out in Chianti (Central Italy) on Sangiovese. The soils of the vineyards differentiated in structure, porosity and related hydropedological characteristics, as well as in salinity. Soil spatial variability was deeply affected by earth movement carried out before vine plantation. Six plots were selected in the different hydrological functional units of the two vineyards, that is, at summit, backslope and footslope morphological positions, to monitor soil hydrology, grape production and wine quality. Plot selection was based upon a cluster analysis of local slope, topographic wetness index (TWI), and cumulative moisture up to the root limiting layer, appreciated by means of a detailed combined geophysical survey. Water content, redox processes and temperature were monitored, as well as yield, phenological phases, and chemical analysis of grapes. The isotopic ratio δ&lt;sup&gt;13&lt;/sup&gt;C was measured in the wine ethanol upon harvesting to evaluate the degree of stress suffered by vines. The grapes in each plot were collected for wine making in small barrels. The wines obtained were analysed and submitted to a blind organoleptic testing. &lt;br&gt;&lt;/br&gt; The results demonstrated that the combined application of the two hydropedological models can be used for the prevision of the moisture status of soils cultivated with grape during summertime in Mediterranean climate. As correctly foreseen by the models, the amount of mean daily transpirable soil water (TSW) during the growing season differed considerably between the vineyards and increased significantly along the three positions on slope in both vineyards. The water accumulation along slope occurred in every year, even during the very dry 2006. The installation of indicators of reduction in soils (IRIS) tubes allowed confirmation of the occurrence of reductive processes in the most shallow soil. &lt;br&gt;&lt;/br&gt; Both Sangiovese grape yield and quality of wine were influenced by the interaction between TSW content and salinity, sometimes contrary to expectations. Therefore, the studied hydropedological models were not relevant to predict grape yield and wine quality in all the hydrological functional units. The diffusion of hydropedological models in precision viticulture could be boosted considering salinity along with topography and soil hydrological characteristics

    Blackleg of rapeseed

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    Unless blackleg can be controlled there is little future for rapeseed as a major commercial crop in W.A. Until 1972, oilseed rape showed great promise as an alternative cash crop for Western Australian farmers, especially in the Great Southern and south coastal areas. However, like most other cruciferous crops, rape is prone to attack from diseases and insect pests. Most of these can be controlled, but the fungus disease blackleg (Leptosphaeria maculans) emerged as a major threat to the industry. Clearly, unless the disease can be controlled, there is little future for rapeseed as a major commercial crop in Western Australia

    Grosulfeimin and new related guaianolides from cynara scolymus L.

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    Three new guaianolides 11-H-13-rnethylsulfonylgrosheirnin 5 (Grosulfeirnin), 8-deoxy-11, 13-dihydroxygrosheimin 7 and 8-deoxy-11-hydroxy-13-chlorogrosheimin 8 have been isolated from the leaves of Cynara scolymus L. Besides, 8-epigrosheirnin 9 has been isolated for the ftrst time frorn this source. The structures were deterrnined by spectroscopical rnethods and by chernical correlations

    Antibodies from patients with rheumatoid arthritis target citrullinated histone 4 contained in neutrophils extracellular traps.

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    Histone deimination regulates gene function and contributes to antimicrobial response, allowing the formation of neutrophil extracellular traps (NETs). Deiminated proteins are target of anti-citrullinated peptides antibodies (ACPA) in rheumatoid arthritis (RA). OBJECTIVE: The objective of this paper is to test the hypothesis that RA sera react with deiminated histones contained in NETs. METHODS: Neutrophils from peripheral blood were stimulated with A23187 and acid treated; NETosis was induced by phorbol myristate acetate, and NET proteins were isolated. Sera were tested by immunoblot on acid extracted proteins from neutrophils and from NETs, and by ELISA on deiminated histone H4 or H4-derived peptides. Bands reactive with RA sera were excised from gels, digested with trypsin and subjected to matrix-assisted laser desorption/ionisation time of flight (MALDI-TOF) analysis, before and after derivatisation to detect citrullinated peptides. RESULTS: RA sera reacted with a deiminated antigen of 11 KDa from activated neutrophils, recognised also by anti-H4 and antideiminated H4 antibodies. A similar reactivity was observed with NET proteins. The antigen from neutrophils or NETs was identified as citrullinated H4 by MALDI-TOF analysis. By ELISA, RA sera bound in vitro citrullinated H4. Citrullinated H4 14-34 and 31-50 peptides detected antibodies in 67% and 63% of RA sera and in less than 5% of controls; antibody titre was correlated with anti-CCP2. CONCLUSIONS: Citrullinated H4 from activated neutrophils and NETs is a target of antibodies in RA, and synthetic citrullinated H4-derived peptides are a new substrate for ACPA detection. As NETosis can generate antigens for ACPA, these data suggest a novel connection between innate and adaptive immunity in RA

    Mutations at the same residue (R50) of Kir6.2 (KCNJ11) that cause neonatal diabetes produce different functional effects

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    Heterozygous mutations in the human Kir6.2 gene (KCNJ11), the pore-forming subunit of the ATP-sensitive K(+) channel (K(ATP) channel), are a common cause of neonatal diabetes. We identified a novel KCNJ11 mutation, R50Q, that causes permanent neonatal diabetes (PNDM) without neurological problems. We investigated the functional effects this mutation and another at the same residue (R50P) that led to PNDM in association with developmental delay. Wild-type or mutant Kir6.2/SUR1 channels were examined by heterologous expression in Xenopus oocytes. Both mutations increased resting whole-cell currents through homomeric and heterozygous K(ATP) channels by reducing channel inhibition by ATP, an effect that was larger in the presence of Mg(2+). However the magnitude of the reduction in ATP sensitivity (and the increase in the whole-cell current) was substantially larger for the R50P mutation. This is consistent with the more severe phenotype. Single-R50P channel kinetics (in the absence of ATP) did not differ from wild type, indicating that the mutation primarily affects ATP binding and/or transduction. This supports the idea that R50 lies in the ATP-binding site of Kir6.2. The sulfonylurea tolbutamide blocked heterozygous R50Q (89%) and R50P (84%) channels only slightly less than wild-type channels (98%), suggesting that sulfonylurea therapy may be of benefit for patients with either mutation

    Maturity-Onset Diabetes of the Young in Children With Incidental Hyperglycemia:: A multicenter Italian study of 172 families

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    OBJECTIVE - To investigate the prevalence of maturity-onset diabetes of the young (MODY) in Italian children With incidental hyperglycemia. RESEARCH DESIGN AND METHODS - Among 748 subjects age 1-18 years with incidental hyperglycemia, minimal diagnostic criteria for MODY were met by 172 families. Mutational analyses of the glucokinase (GCK) and hepatocyte nuclear factor lot (HNF1A) genes were performed. RESULTS - We identified 85 GCK gene mutations in 109 probands and 10 HNF1A mutations in 12 probands. In GCK patients, the median neonatal weight and age at the first evaluation were lower than those found in patients with HNF1A mutations. Median fasting plasma glucose and impaired fasting glucose/impaired glucose tolerance frequency after oral glucose tolerance testing were higher in GCK patients, who also showed a lower frequency of diabetes than HNF1A patients. CONCLUSIONS - GCK mutations are the prevailing cause of MODY (63.4%) when the index case is recruited in Italian children with incidental hyperglycemia
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