40 research outputs found

    Detection of accase target-site resistant Alopecurus myosuroides huds (black-grass) in Belgian populations

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    Black-grass is a common grass weed, widely spread in Northern Europe and also in Belgium. For ages, it has been an increasing problem in industrial crops, especially winter cereals. The first case of resistance in Belgium was reported in 1996 by Robert Bulcke (Eelen et al., 1996). Yet the resistance mechanism was not specified. Since then, no more information was published about the evolution Belgium, while research continued in the United Kingdom and in France. Moreover, during the last decade, progress in molecular biology allowed to highlight the mechanism of target-site resistance. A simple PCR method allows to detect the mutation conferring resistance to herbicide. After two years of resistance monitoring in Belgium, mostly in the Walloon part, some populations have been clearly identified as highly resistant to ACCase inhibitor. These populations have been tested by molecular biology so as to detect the single nucleotide polymorphism (SNP) involved in this case. The method employed was the Polymerase Chain Reaction Allele Specific Assays (PASA: DĂ©lye, 2002a) for the mutation Ile-1781-Leu that confers a target-site resistance to ACCase inhibitors. Those analyses were performed on plant material issued from bioassays, either in glasshouses or in Petri dishes. Leaves have been collected from plants which survived a fenoxaprop-P treatment applied in a glasshouse single dose assay. Seedlings from resistant populations grown in Petri dishes containing either fenoxaprop-P or cycloxydim provided the second type of sample. Ile1781 mutants were discovered within three populations. Each mutant plant was heterozygote. Five of those samples have been sequenced to confirm PASA results and everyone was matching. Moreover, they were all issued from Petri dishes containing cycloxydim, known to be unaffected by enhanced metabolism, confirming that theses populations are indeed target-site resistant

    New thermal insulation fiberboards from cake generated during biorefinery of sunflower whole plant in a twin-screw extruder

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    The objective of this study was to manufacture new thermal insulation fiberboards by thermo-pressing. The starting material was a slightly deoiled cake (17.6% oil content), generated during the biorefinery of sunflower (Helianthus annuus L.) whole plant in a co-rotating (Clextral BC 45, France) twin-screw extruder. All fiberboards produced were cohesive mixtures of proteins and lignocellulosic fibers, acting respectively as binder and reinforcing fillers in what could be considered as a natural composite. The molding experiments were conducted using a 400 ton capacity heated hydraulic press (Pinette Emidecau Industries, France). The influence of molding conditions on board density, mechanical properties and heat insulation properties was examined. Molding conditions included mold temperature (140-200°C), pressure applied (150-250 kgf/cmÂČ) and molding time (40-76 s), and these greatly affected board density and thus the mechanical and heat insulation properties. Board density increased with increasingly extreme molding conditions, rising from 500 to 858 kg/mÂł. The mechanical properties increased at the same time (from 52 to 660 kPa for flexural strength at break, from 5.9 to 49.4 MPa for elastic modulus, from 0.5 to 7.7 kJ/mÂČ for Charpy impact strength, and from 19.2 to 47.1° for Shore D surface hardness). Conversely, heat insulation properties improved with decreasing board density, and the lowest thermal conductivity (88.5 mW/m K at 25°C) was obtained with the least dense fiberboard. The latter was produced with a 140°C mold temperature, a 150 kgf/cmÂČ pressure applied and a 40 s molding time. A medium mold temperature (160°C) was needed to obtain a good compromise between mechanical properties (272 kPa for flexural strength at break, 26.3 MPa for elastic modulus, 3.2 kJ/mÂČ for Charpy impact strength, and 37.3° for Shore D surface hardness), and heat insulation properties (99.5 mW/m K for thermal conductivity).The corresponding board density was medium (687 kg/mÂł). Because of their promising heat insulation properties, these new fiberboards could be positioned on walls and ceilings for thermal insulation of buildings. The bulk cake also revealed very low thermal conductivity properties (only 65.6 mW/m K at 25°C) due to its very low bulk density (204 kg/mÂł). It could be used as loose fill in the attics of houses

    Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

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    BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

    COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

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    Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≀ 18 years: 69, 48, 23; 85%), older adults (≄ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P &lt; 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

    Black-grass Resistance to Herbicides: Three Years of Monitoring in Belgium

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    peer reviewedBlack-grass (Alopecurus myosuroides HUDS.) is a common weed of cereal crops widely spread in Northern Europe. Even if the first Belgian case of resistance was reported in 1996, until now, Belgium was quite spared of this problem and only a few restricted areas were con-cerned: the Polders, the marshland of the Escaut River and the Fosses-la-Ville region. About 90 seed samples were collected trough the South part of Belgium and in the Polders during July 2006, 2007 and 2008. These populations were tested in greenhouse conditions by spraying plantlets with herbicides of three modes of action. The herbicides used were photo-synthesis inhibitor, ACCase inhibitors and ALS inhibitors. Susceptible and resistant standard populations (Rohtamsted and Peldon) were included in the test in order to validate it and to permit wild populations classification according to “R” rating system. Populations showed differences of susceptibility to photosynthesis inhibitor, ACCase inhibitors and ALS inhibitors. For each herbicide mode of action, it was possible to find at least one population in each resistance class of the “R” rating system. Furthermore, it appeared that resistance was not confined to restricted areas listed above anymore

    Revue de l’écologie des capacitĂ©s de propagation du vulpin des champs (Alopecurus myosuroides Huds.) en relation avec la rĂ©sistance aux herbicides

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    Alopecurus myosuroides Huds. (black-grass) has always been a major concern for cereal growers, and the development of herbicide resistance does not improve the situation. This review article summarizes the different traits involved in the dispersal pattern of herbicide resistant black-grass individuals within a susceptible field population. Therefore, the whole life cycle of black-grass is depicted from the seed to the seed. From the early vegetative development to the seed falling, every stage is described, taking into account how herbicide resistance can influence or exert a different impact compared to susceptible plants.Alopecurus myosuroides Huds. (vulpin des champs) a toujours Ă©tĂ© une prĂ©occupation majeure pour les cĂ©rĂ©aliculteurs et le dĂ©veloppement de la rĂ©sistance aux herbicides n’amĂ©liore pas la situation. Cet article de synthĂšse rĂ©sume les diffĂ©rents critĂšres impliquĂ©s dans les modĂšles de dispersion d’individus de vulpin des champs au sein d’un champ ou d’une population sensible. Pour ce faire, le cycle complet du vulpin est dĂ©crit de la semence Ă  la semence. Depuis le dĂ©veloppement vĂ©gĂ©tatif prĂ©coce jusqu’à la chute de la graine, chaque Ă©tape est dĂ©crite en prenant en compte comment la rĂ©sistance aux herbicides peut influencer ou exercer un impact diffĂ©rent par rapport Ă  des plantes sensibles.Etude de la dynamique de propagation de la rĂ©sistance par mutation de cible aux herbicides inhibiteurs de l’AcĂ©toLactateSynthase dans des populations de Vulpin des champs (Alopecurus myosuroides HUDS.

    Treatment influence on herbicide resistance level of Belgian Alopecurus myosuroides populations (black-grass)

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    Black-grass is a common grass weed, widely spread in Northern Europe and also in Belgium. For ages, it has been an increasing problem in industrial crops, especially winter cereals. Therefore, farmers started to spray herbicide intensively and soon cases of failure occurred for different molecules and different modes of action. Black-grass populations have been tested in greenhouses to assess the influence of an herbicide treatment as to the resistance level regarding three different herbicides: chlortoluron, fenoxaprop-P and mesosulfuron+iodosulfuron. Black-grass seeds were collected in field trials in six locations in Belgium, on individuals which have survived the herbicide treatment. Each population comes from trial plots, measuring 2 meters wide by 5 meters long and characterized by a single or a combination of products. Herbicides sprayed were isoproturon, flufenacet+diflufenican, ACCase inhibitors and ALS inhibitors. Seeds were also collected in the untreated plots. The population present in these last ones corresponds to the former population, before the herbicide selection pressure was applied. In the glasshouse assay, this population was used as the standard population to compare with other populations issued from the same field. The 'R' rating system was set up with this population to assess the evolution of resistance level, year in, year out. Rothamsted and Peldon populations were also included as cross-reference. Each field population presented different behaviours towards herbicide applied in greenhouses and some cases of resistance can be highlighted. Generally, a reduction of treatment efficiency between field and greenhouse results was clearly visible for the whole of studied active ingredients. Indeed, a distribution shift of the populations towards higher resistance classes could be observed. This is particularly remarkable for active ingredients sharing the same mode of action. For example, it has been found that populations already sprayed with fenoxaprop-P on the field showed a higher resistance level to fenoxaprop-P than to mesosulfuron in the greenhouse test

    BLACK-GRASS (ALOPECURUS MYOSUROIDES HUDS.) HEREDITY OF TARGET-SITE RESISTANCE TO ALS INHIBITING HERBICIDE

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    peer reviewedTarget-site resistance heredity in black-grass was assessed by observing the percentage of resistant individuals engendered by crossings. After germination, plants were genotyped as homo- or heterozygote for the W574 mutation on the ALS gene, which induces herbicide resistance. Individuals were then transplanted outdoor and crossed between one another and with other individuals issued from a population known as susceptible. To avoid an external pollen contamination, plants were enclosed within pollen-proof clothing during flowering time. Allogamy rate was also tested, by isolating heads one by one. Seeds issued from these crossings were collected and tested in glasshouses. Their DNA was also analysed.L’hĂ©rĂ©ditĂ© de la rĂ©sistance par mutation de cible chez le vulpin des champs a Ă©tĂ© Ă©valuĂ©e en observant le pourcentage d’individus rĂ©sistants engendrĂ©s par croisements. AprĂšs germination, les plantes ont Ă©tĂ© gĂ©notypĂ©es comme homo- ou hĂ©tĂ©rozygotes pour la mutation W574 du gĂšne de l’ALS confĂ©rant la rĂ©sistance. Les individus sont ensuite transplantĂ©s en parterre extĂ©rieur et croisĂ©s entre eux et avec des individus issus d’une population sensible connue. Pour Ă©viter un apport de pollen extĂ©rieur, les plantes sont ensachĂ©es dans un tissu pollen-proof lors de la floraison. Le taux d’autogamie facultative a Ă©galement Ă©tĂ© testĂ©e, en isolant les Ă©pis un par un. Les semences issues des croisements sont ensuite rĂ©coltĂ©es et testĂ©es en serres. Leur ADN a Ă©galement Ă©tĂ© analysĂ©

    Capacités de croisement de vulpins (Alopecurus myosuroides HUDS.) résistants par mutation de cible de l'ALS

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    peer reviewedBlack-grass crossings were conducted outdoor for two successive years in a way to determine the percentage of resistant black-grass that can be engendered in one generation, after the introduction of one Target-Site resistant individual. After germination, plants were genotyped and couples of resistant and susceptible individuals were formed, then planted outdoor and enclosed with a pollen-proof cloth to avoid any external pollen contamination. Seeds were collected and tested in glasshouses with herbicide spraying. DNA analyses were also performed on surviving plants to distinguish hetero- from homozygotes. The resistance level of the progeny seems to be fairly high and Mendelean distribution is generally confirmed. The offspring of self-crossings was also observed to assess the facultative autogamy ability, according to the genotype and the presence of mutant ALS alleles (position W-574)

    Capacité de Dispersion du Pollen de vulpin des champs résistant par mutation de cuble aux herbicides inhibiteurs de l'ALS

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    Target-Site Resistant (TSR) black-grass individuals were introduced in a field, at different growing stages to be synchronised with autochthonous population. Patches of susceptible black-grass were created by setting protective canvas on few areas (from 0,5 up to 32mÂČ), during herbicide spraying and they were removed afterwards. Those patches were disposed along rays starting from the introduction point at distances from 2 to 128 meters. In those patches, local black-grass grew regularly and was able to receive some pollen from the resistant individuals, located in the centered emitting area. The herbicide field treatment (mesosulfuron+iodosulfuron : 15+3 g.a.i.ha-1) was efficient, confirming that the local population is susceptible to ALS inhibitors, was preceded by another herbicide treatment targeting only broad-leaves weeds, performed on the entire field, including patches, such as the rest of cultural practices such as fertilization, and fungicide and insecticide treatment. All seeds were harvested in each patches separately and tested in glasshouse. Seed samples were sprayed with sulfometuron, herbicide active ingredient known not to be affected by non-target site resistance, in a way to detect the percentage of resistant black-grass that can be engendered after the introduction of TSR individuals and to determine the distance resistant pollen can cover. DNA analyses were performed on surviving plants to confirm the presence of the mutation
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