38 research outputs found
Cyclamen mite (Acari: Tarsonemidae) monitoring in eastern Canada strawberry (Rosaceae) fields and its potential control by the predatory mite Neoseiulus cucumeris (Acari: Phytoseiidae)
The cyclamen mite (Phytonemus pallidus Banks; Acari:
Tarsonemidae) has recently become a more important pest in Canadian
strawberry (Fragaria Ă— ananassa Duchesne ex Rozier; Rosaceae)
production with the withdrawal of the pesticide endosulfan in 2016, yet its
phenology under field conditions in Canada is poorly known. Moreover,
while its biological control with predatory mites has shown potential, the
effectiveness of this method has never been investigated under eastern
Canadian field conditions. The objectives of this study were to 1) monitor
populations of P. pallidus in strawberries for two consecutive years; and 2)
evaluate the in-field potential of the predatory mite Neoseiulus cucumeris
Oudemans (Acari: Phytoseiidae). Monitoring cyclamen mite populations in
the field revealed new critical knowledge about its phenology in eastern
Canada, such as activity until late November. The predator N. cucumeris
was able to effectively suppress cyclamen mites the first year, but appeared
to be too cold-sensitive to maintain adequate control toward the end of the
season. Furthermore, the high rates of predator release required would most
likely be cost prohibitive for commercial use. Control of the cyclamen mite
in strawberries remains a complex issue that will require further research
L’agriculture : levier d’innovation pour l’aménagement des territoires périurbains ? Le cas du Pays Voironnais
At the heart of numerous conflicts and representations, the periurban agricultural spaces are submitted to conservation today. Real wilderness reservoirs, they serve mainly to contain the urban sprawl and to offer spaces of breath to the city-dwellers of the diffuse city. In periurban territories in height identity construction, cannot they constitute a lever of innovation of the urban planning?Au cœur de nombreux conflits et représentations, les espaces agricoles périurbains sont aujourd’hui soumis à préservation. Véritables réservoirs de naturalité, ils servent principalement à contenir l’étalement urbain et à offrir des espaces de respiration aux citadins de la ville diffuse. Dans des territoires périurbains en plein construction identitaire, ne peuvent-ils pas constituer un levier d’innovation de l’aménagement
Connectivites mixtes, connectivites indifférenciées et syndromes de chevauchement associés aux connectivites à début pédiatrique (présentation et évolution)
TOULOUSE3-BU Santé-Centrale (315552105) / SudocSudocFranceF
Essai d'un kit de diagnostic très précoce de gestation chez la jument ("l'ECF horse test")
Cette étude a été menée au cours de l'année 2004 au service de pathologie de la reproduction de l'Ecole Nationale Vétérinaire de Nantes. Son objectif est de déterminer l'efficacité d'un test de diagnostic précoce de gestation chez la jument : l'ECF Horse Test utilisable dès le 3ème jour post-ovulation chez la jument. Le principe de ce test est de mettre en évidence dans le sérum de juments gravides, l'Early Pregnancy Factor ou EPF à l'aide d'une technique d'immunochromatographie. 41 tests ont été réalisés à partir du sérum de 35 juments différentes, dont 24 ont été diagnostiquées gravides par échographie au 14ème jour post-ovulation. Les résultats faux négatifs sont très élevés. La sensibilité, la spécificité, la valeur prédictive positive et la valeur prédictive négative qui en résultent sont respectivement de 10%, 100%, 100% et 29%. L'efficacité de ce test est donc de 34%. Ces chiffres sont en accord avec ceux d'autres études et sont largement inférieurs à ceux communiqués par le fabricant et ne sont pas suffisants pour justifier la commercialisation de ce test.NANTES-Ecole Nat.Vétérinaire (441092302) / SudocSudocFranceF
Evaluation of various sources of viral infection in strawberry fields of Quebec, Canada
The decline of cultivated strawberry (Fragaria Ă— ananassa Duchesne ex Rozier; Rosaceae) observed in the province of Quebec, Canada, between 2012 and 2014 was mostly caused by persistent viruses: strawberry mild yellow edge virus (SMYEV) (Potexvirus; Alphaflexiviridae) and strawberry crinkle virus (SCV) (Cytorhabdovirus; Rhabdoviridae); and semi-persistent viruses: strawberry mottle virus (SmoV) (Secoviridae), strawberry vein banding virus (SVBV) (Caulimovirus; Caulimoviridae), and strawberry pallidosis virus (SPaV) (Crinivirus: Closteroviridae) transmitted by insect vectors. The objective of this study was to determine the sources of viral contamination in commercial strawberry fields in Quebec. Specifically, we wished to 1) determine the prevalence of persistent viruses in winged strawberry aphid Chaetosiphon fragaefolii (Cockerell) (Hemiptera: Aphididae) specimens captured; 2) determine the prevalence of all viruses in wild strawberry Fragaria virginiana Miller plants near commercial plantings; and 3) evaluate the viral contamination of strawberry transplants obtained from nurseries and tested before and after planting in commercial strawberry fields. Results indicated high percentage (38%) of the aphids (n = 205) and high percentage (67%) of F. virginiana patches (n = 12) were infected by strawberry viruses. Ultimately, our results showed a low percentage (5%) of the plants from various nurseries (n = 56) were infected before planting, whereas a third (29%) of the healthy exposed plants in the fields (n = 96) became rapidly infected by insect vectors within a year of having been planted. This study provides significant insights on the relative importance of the various sources of contamination in Quebec strawberry fields: C. fragaefolii versus F. virginiana versus nurseries versus post-nursery infections through exposure to virus-carrying insects
Flight phenology and trap selection for monitoring potential viral vector Aphididae and Aleyrodidae (Hemiptera) in strawberry (Rosaceae) fields of Québec, Canada
Strawberry decline disease, predominantly viral in origin, was a serious threat to the strawberry (Fragaria x ananassa Duchesne ex Rozier; Rosaceae) fields of Québec, Canada, between 2012 and 2014. Our aim was to monitor the abundance and activity of the main insect vectors: the strawberry aphid, Chaetosiphon fragaefolii (Cockerell) (Hemiptera: Aphididae) and the greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae). First, we compared the effectiveness of two trapping techniques, the yellow sticky trap and the yellow pan trap. Results showed that the sticky traps are more effective in capturing alates in flight. Second, we determined the peak flight period for each of the two vectors in several locations within the province of Québec. Results suggest that the peak abundance of winged C. fragaefolii is during the first two weeks of August, while the peak abundance of T. vaporariorum is in the last two weeks of September. Overall trap captures also found 53 different species of winged aphids, and we documented a new distribution record on commercial strawberry fields in Québec, Aleyrodes spiraeoides (Quaintance) (Hemiptera: Aleyrodidae). Species composition and significant information of flight periods will be useful for the management of virus-transmitting insects associated with strawberry decline disease in Québec.De 2012 à 2014, le dépérissement des fraisières, principalement d’origine virale, fut une menace sérieuse pour les champs de fraises (Fragaria x ananassa Duchesne ex Rozier; Rosaceae) du Québec, Canada. Notre objectif était de faire un suivi de l’abondance et l’activité des principaux vecteurs: le puceron du fraisier, Chaetosiphon fragaefolii (Cockerell) (Hemiptera: Aphididae) et l’aleurode des serres, Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae). Premièrement, nous avons comparé l’efficacité de deux techniques de dépistage, le piège-collant et le piège-bol jaune. Les résultats indiquent que les pièges-collants sont plus efficaces pour capturer les allates en vol. Deuxièmement, nous avons déterminé les pics de vol pour chacun des vecteurs dans plusieurs régions de la province. Les résultats suggèrent que le pic d’abondance de C. fragaefolii ailé se situe dans les deux premières semaines d’août, celui de T. vaporariorum se situe dans les deux dernières semaines de septembre. Les captures ont également permis d’identifier 53 espèces différentes de pucerons ailés et une nouvelle mention de distribution dans les fraisières commerciales au Québec, soit l’aleurode de l’iris Aleyrodes spiraeoides (Quaintance) (Hemiptera: Aleyrodidae). La composition des espèces et les renseignements significatifs sur les périodes de vol seront utiles dans la gestion des insectes vecteurs de virus associés au dépérissement des fraisières au Québec
Flight phenology and trap selection for monitoring potential viral vector Aphididae and Aleyrodidae (Hemiptera) in strawberry (Rosaceae) fields of Québec, Canada—ERRATUM
Disruption of Botryococcus braunii colonies by glycoside hydrolases
International audienceMicroalgae are a promising alternative resource to fossil-based products. Botryococcus braunii is a colonial green microalga having the ability to convert CO2 by photosynthesis into long chain hydrocarbons. These are excreted and trapped in an extracellular matrix (ECM). A panel of glycosidases ranging from arabinanase, galactananase to endoglucanase was tested for their ability to lyse the polysaccharides maintaining the B. braunii colony integrity in order to release the hydrocarbons present in the extracellular matrix without harming the cells. The BpGH9 endoglucanase from Bacillus pumilus was fused with CtCBM3a from Clostridium thermocellum and yellow fluorescent protein to probe the presence of microcrystalline cellulose in the cell wall of B. braunii and to increase the efficacy of the endoglucanase. All the tested enzymes were able to some extent to dissociate the cells from the extracellular matrix while keeping them alive, suggesting the feasibility of a semi-continuous in situ recovery of hydrocarbons
Altered angiogenesis in low birth weight individuals: a role for anti-angiogenic circulating factors
International audienceObjective: Low birth weight (LBW) is a risk factor for hypertension at adulthood. Endothelial progenitor cells (EPCs) dysfunction has been characterized in LBW neonates. We hypothesized that changes in soluble, plasma pro-or anti-angiogenic factors are associated with EPCs dysfunction and impaired angiogenesis in LBW neonates. Method: Venous umbilical cord blood was collected from 42 normal, term neonates and 75 LBW neonates. Cord blood endothelial colony forming cells (ECFC) from control patients were cultured in the presence of 10% of serum obtained from both groups. Results: The proliferation and the migration of ECFC were significantly reduced when cultured with 10% of serum of LBW neonates compared to serum of control neonates. Matrigel invasion assay was not significantly altered. Umbilical vein plasma VEGF concentration was significantly reduced in LBW neonates while that of sVEGFR and PF4 were significantly higher. Addition of VEGF corrected the inhibitory effect of LBW serum on normal ECFC proliferation. Conclusions: Serum obtained from LBW babies contains factors that exhibit an antiangiogenic effect on ECFC proliferation and migration. VEGF/sVEGF/PF4 pathway seems to be involved in the EPCs dysfunction in LBW neonates
Mycophenolic acid area under the concentration-time curve is associated with therapeutic response in childhood-onset lupus nephritis
International audienceBackground: Mycophenolic acid (MPA), the active compound of mycophenolate mofetil (MMF), is widely used in lupus nephritis treatment. Therapeutic drug monitoring of adults suggests that area under the concentration-time curve (AUC) of MPA (MPA-AUC) is associated with clinical outcomes, but childhood data are scarce.Methods: Retrospective study of 27 children with biopsy-proven lupus nephritis treated with MMF between 2008 and 2016. In 25 children, MPA-AUC was performed within 6 months after kidney biopsy and MMF initiation. Treatment response at 6 months was defined as normal or improved GFR by 25% compared with baseline, 50% reduction of proteinuria to 45, 30-45, and 45 mg h/L was significantly associated with therapeutic response (OR 3.6, 95% CI 2.4-9.5, p = 0.03).Conclusions: Therapeutic drug monitoring leading to individualized dosing may improve efficacy of MMF. MPA-AUC > 45 mg h/L is associated with better response rate and may be considered as a target value in pediatric lupus nephritis