96 research outputs found
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Evaluating Experimental Design of ERT for Soil Moisture Monitoring in Contour Hedgerow Intercropping Systems
Contour hedgerow intercropping systems have been proposed as an alternative to traditional agricultural practice with a single crop, as they are effective in reducing run-off and soil erosion. However, competition for water and nutrients between crops and associated hedgerows may reduce the overall performance of these systems. To get a more detailed understanding of the competition for water, spatially resolved monitoring of soil water contents in the soil-plant-atmosphere system is necessary. Electrical resistivity tomography (ERT) is potentially a valuable technique to monitor changes in soil moisture in space and time. In this study, the performance of different ERT electrode arrays to detect the soil moisture dynamics in a mono- and an intercropping system was tested. Their performance was analyzed based on a synthetic study using geophysical measures, such as data recovery and resolution, and using spatial statistics of retrieved water content, such as an adjusted coefficient of variation and semivariances. The synthetic ERT measurements detected differences between the cropping systems and retrieved spatial structure of the soil moisture distribution, but the variance and semivariance were underestimated. Sharp water content contrasts between horizons or in the neighborhood of a root water uptake bulb were smoothened. The addition of electrodes deeper in the soil improved the performance, but sometimes only marginally. ERT is therefore a valuable tool for soil moisture monitoring in the field under different cropping systems if an electrode array is used which can resolve the patterns expected to be present in the medium. The use of spatial statistics allowed to not only identify the overall model recovery, but also to quantify the recovery of spatial structures
Recommended from our members
Evaluating Experimental Design of ERT for Soil Moisture Monitoring in Contour Hedgerow Intercropping Systems
Contour hedgerow intercropping systems have been proposed as an alternative to traditional agricultural practice with a single crop, as they are effective in reducing run-off and soil erosion. However, competition for water and nutrients between crops and associated hedgerows may reduce the overall performance of these systems. To get a more detailed understanding of the competition for water, spatially resolved monitoring of soil water contents in the soil-plant-atmosphere system is necessary. Electrical resistivity tomography (ERT) is potentially a valuable technique to monitor changes in soil moisture in space and time. In this study, the performance of different ERT electrode arrays to detect the soil moisture dynamics in a mono- and an intercropping system was tested. Their performance was analyzed based on a synthetic study using geophysical measures, such as data recovery and resolution, and using spatial statistics of retrieved water content, such as an adjusted coefficient of variation and semivariances. The synthetic ERT measurements detected differences between the cropping systems and retrieved spatial structure of the soil moisture distribution, but the variance and semivariance were underestimated. Sharp water content contrasts between horizons or in the neighborhood of a root water uptake bulb were smoothened. The addition of electrodes deeper in the soil improved the performance, but sometimes only marginally. ERT is therefore a valuable tool for soil moisture monitoring in the field under different cropping systems if an electrode array is used which can resolve the patterns expected to be present in the medium. The use of spatial statistics allowed to not only identify the overall model recovery, but also to quantify the recovery of spatial structures
Recommended from our members
Evaluating Experimental Design of ERT for Soil Moisture Monitoring in Contour Hedgerow Intercropping Systems
Contour hedgerow intercropping systems have been proposed as an alternative to traditional agricultural practice with a single crop, as they are effective in reducing run-off and soil erosion. However, competition for water and nutrients between crops and associated hedgerows may reduce the overall performance of these systems. To get a more detailed understanding of the competition for water, spatially resolved monitoring of soil water contents in the soil-plant-atmosphere system is necessary. Electrical resistivity tomography (ERT) is potentially a valuable technique to monitor changes in soil moisture in space and time. In this study, the performance of different ERT electrode arrays to detect the soil moisture dynamics in a mono- and an intercropping system was tested. Their performance was analyzed based on a synthetic study using geophysical measures, such as data recovery and resolution, and using spatial statistics of retrieved water content, such as an adjusted coefficient of variation and semivariances. The synthetic ERT measurements detected differences between the cropping systems and retrieved spatial structure of the soil moisture distribution, but the variance and semivariance were underestimated. Sharp water content contrasts between horizons or in the neighborhood of a root water uptake bulb were smoothened. The addition of electrodes deeper in the soil improved the performance, but sometimes only marginally. ERT is therefore a valuable tool for soil moisture monitoring in the field under different cropping systems if an electrode array is used which can resolve the patterns expected to be present in the medium. The use of spatial statistics allowed to not only identify the overall model recovery, but also to quantify the recovery of spatial structures
In vitro comparison of antiviral drugs against feline herpesvirus 1
BACKGROUND: Feline herpesvirus 1 (FHV-1) is a common cause of respiratory and ocular disease in cats. Especially in young kittens that have not yet reached the age of vaccination, but already lost maternal immunity, severe disease may occur. Therefore, there is a need for an effective antiviral treatment. In the present study, the efficacy of six antiviral drugs, i.e. acyclovir, ganciclovir, cidofovir, foscarnet, adefovir and 9-(2-phosphonylmethoxyethyl)-2, 6-diaminopurine (PMEDAP), against FHV-1 was compared in Crandell-Rees feline kidney (CRFK) cells using reduction in plaque number and plaque size as parameters. RESULTS: The capacity to reduce the number of plaques was most pronounced for ganciclovir, PMEDAP and cidofovir. IC(50 (NUMBER) )values were 3.2 ÎŒg/ml (12.5 ÎŒM), 4.8 ÎŒg/ml (14.3 ÎŒM) and 6 ÎŒg/ml (21.5 ÎŒM), respectively. Adefovir and foscarnet were intermediately efficient with an IC(50 (NUMBER) )of 20 ÎŒg/ml (73.2 ÎŒM) and 27 ÎŒg/ml (140.6 ÎŒM), respectively. Acyclovir was least efficient (IC(50 (NUMBER) )of 56 ÎŒg/ml or 248.7 ÎŒM). All antiviral drugs were able to significantly reduce plaque size when compared with the untreated control. As observed for the reduction in plaque number, ganciclovir, PMEDAP and cidofovir were most potent in reducing plaque size. IC(50 (SIZE) )values were 0.4 ÎŒg/ml (1.7 ÎŒM), 0.9 ÎŒg/ml (2.7 ÎŒM) and 0.2 ÎŒg/ml (0.7 ÎŒM), respectively. Adefovir and foscarnet were intermediately potent, with an IC(50 (SIZE) )of 4 ÎŒg/ml (14.6 ÎŒM) and 7 ÎŒg/ml (36.4 ÎŒM), respectively. Acyclovir was least potent (IC(50 (SIZE) )of 15 ÎŒg/ml or 66.6 ÎŒM). The results demonstrate that the IC(50 (SIZE) )values were notably lower than the IC(50 (NUMBER) )values. The most remarkable effect was observed for cidofovir and ganciclovir. None of the products were toxic for CRFK cells at antiviral concentrations. CONCLUSION: In conclusion, measuring reduction in plaque number and plaque size are two valuable and complementary means of assessing the efficacy of an antiviral drug. By using these parameters for six selected antiviral drugs, we found that ganciclovir, PMEDAP, and cidofovir are the most potent inhibitors of FHV-1 replication in CRFK cells. Therefore, they may be valuable candidates for the treatment of FHV-1 infection in cats
Les unités médico-psychiatriques : les soins partagés en santé mentale
Cet article dĂ©crit le fonctionnement dâune unitĂ© hospitaliĂšre originale, couplant approche somatique et psychiatrique sous rubrique gĂ©nĂ©rique dâune UnitĂ© MĂ©dico-Psycho-Sociale (UMPS) implantĂ©e au sein du CHU dâAngers depuis 1996. Nous proposons dâexaminer lâintĂ©rĂȘt de cette mixitĂ©, tout en interrogeant ses limites et ses difficultĂ©s de fonctionnement. LâintĂ©rĂȘt de la structure est de proposer une approche pluridisciplinaire, somatique et psychiatrique dans un mĂȘme lieu de soins. Cette double compĂ©tence de la part des personnels mĂ©dicaux et paramĂ©dicaux est nĂ©cessaire lorsque les avis ponctuels de la consultation-liaison ne suffisent plus et lors de situations complexes, dans lesquelles le double savoir-faire est sollicitĂ©, en lien avec les ressources dâune rĂ©animation et des services de spĂ©cialitĂ©s mĂ©dicales et chirurgicales. Ce type dâunitĂ©, fondĂ©e sur un fonctionnement mixte et Ă binĂŽme confirmĂ© est peu reprĂ©sentĂ©, tant en France quâĂ lâĂ©tranger. La frĂ©quence de la co-morbiditĂ© somatique et organique conduit pourtant Ă les considĂ©rer comme une rĂ©ponse innovante aux difficultĂ©s rencontrĂ©es dans ces prises en charge. Nous dĂ©crivons deux cas cliniques afin dâargumenter notre propos
Ătude exploratoire des caractĂ©ristiques professionnelles d'un Ă©chantillon de suicidants hospitalisĂ©s
Cette Ă©tude a pour objectif de dĂ©crire les caractĂ©ristiques professionnelles dâun Ă©chantillon de suicidants. Un enquĂȘteur a interrogĂ© les suicidants ĂągĂ©s de 18 Ă 65 ans, hospitalisĂ©s consĂ©cutivement dans une unitĂ© spĂ©cialisĂ©e du CHU dâAngers sur une durĂ©e de 6 mois et demi. Au total, 87 suicidants actifs avec un emploi ont Ă©tĂ© interrogĂ©s. Ils ont souvent Ă©tĂ© confrontĂ©s Ă des contraintes organisationnelles dĂ©crites dans la littĂ©rature comme responsables de souffrance mentale liĂ©e au travail. Cela concerne globalement autant les hommes que les femmes. En comparaison aux enquĂȘtes de santĂ© au travail (Sumer, SamotraceâŠ), les suicidants sont plus nombreux Ă ressentir entre autres un stress intense au travail, une conscience professionnelle heurtĂ©e et Ă ĂȘtre en situation tendue selon le modĂšle de Karasek. Cela pourrait ĂȘtre en faveur dâun lien entre les tentatives de suicide et certains facteurs de pĂ©nibilitĂ© mentale au travail. Les rĂ©sultats de cette Ă©tude sont Ă interprĂ©ter avec prudence du fait des phĂ©nomĂšnes de circularitĂ© des donnĂ©es et de la faiblesse de lâĂ©chantillon
Impacts of soil management and climate on saturated and near-saturated hydraulic conductivity: analyses of the Open Tension-disk Infiltrometer Meta-database (OTIM)
Saturated and near-saturated soil hydraulic conductivities Kh (mmâhâ1) determine the partitioning of precipitation into surface runoff and infiltration and are fundamental to soils' susceptibility to preferential flow. Recent studies found indications that climate factors influence Kh, which is highly relevant in the face of climate change. In this study, we investigated relationships
between pedoclimatic factors and Kh and also evaluated effects of land use and soil management. To this end, we collated the Open Tension-disk Infiltrometer Meta-database (OTIM), which contains 1297 individual data entries from 172 different publication sources. We analysed a spectrum of saturated and near-saturated hydraulic conductivities at matric potentials between 0 and 100âmm. We found that methodological details like the direction of the wetting sequence or the choice of method for calculating infiltration rates to hydraulic conductivities had a large impact on the results. We therefore restricted ourselves to a subset of 466 of the 1297 data entries with similar methodological approaches. Correlations between Ks and Kh at higher supply tensions decreased especially close to saturation, indicating a different flow mechanism at and very close to saturation than towards the dry end of the investigated tension range. Climate factors were better correlated with topsoil near-saturated hydraulic conductivities at supply tensions â„â30âmm than soil texture, bulk density and organic carbon content. We find it most likely that the climate variables are proxies for soil macropore networks created by the respective biological activity, pedogenesis and climate-specific land use and management choices. Due to incomplete documentation in the source publications of OTIM, we were able to investigate only a few land use types and agricultural management practices. Land use, tillage system and soil compaction significantly influenced Kh, with effect sizes appearing comparable to the ones of soil texture and soil organic carbon. The data in OTIM show that experimental bias is present, introduced by the choice of measurement time relative to soil tillage, experimental design or data evaluation procedures. The establishment of best-practice rules for tension-disk infiltrometer measurements would therefore be helpful. Future studies are needed to investigate how climate shapes soil macropore networks and how land use and management can be adapted to improve soil hydraulic properties. Both tasks require large numbers of new measurement data with improved documentation on soil biology and land use and management history.</p
Travail et tentatives de suicide
ObjectifLâirruption mĂ©diatique de suicides en lien avec le travail constitue un Ă©lĂ©ment marquant de ces derniĂšres annĂ©es. Ce phĂ©nomĂšne doit mobiliser tous les acteurs de lâentreprise, de lâagent au directeur. Pour envisager une prĂ©vention des suicides liĂ©s au travail, il est important de les dĂ©finir en termes quantitatif et qualitatif. Afin de rĂ©pondre en partie Ă cette problĂ©matique, cette Ă©tude vise Ă prĂ©ciser les caractĂ©ristiques professionnelles dâun Ă©chantillon de suicidants dont une partie annonce un lien entre leur passage Ă lâacte suicidaire et leur travail. MĂ©thodes Cette Ă©tude dâune durĂ©e de six mois a inclus les suicidants actifs ayant un emploi, ĂągĂ©s de 18 Ă 65ans, hospitalisĂ©s au CHU dâAngers. Au total, 87 suicidants consĂ©cutifs ont rĂ©pondu aux questionnaires portant sur les caractĂ©ristiques du travail. RĂ©sultats Les suicidants appartenant au groupe « tentatives de suicide (TS) liĂ©es au travail » dĂ©crivent davantage la prĂ©sence dâĂ©lĂ©ments dâorganisations pathogĂšnes du travail comprenant une surcharge de travail, des dĂ©lais Ă respecter et des dĂ©rangements frĂ©quents. De plus, ils rapportent Ă©galement davantage de conflits dans lâentreprise. Cela concerne en majoritĂ© les cadres et les professions intermĂ©diaires. La proportion des hommes est plus importante parmi les suicidants Ă©tablissant un lien entre leur TS et leur travail, mais les femmes sont aussi concernĂ©es. Discussion Le lien entre le travail et les TS semble davantage provenir de lâorganisation du travail, des rapports avec la hiĂ©rarchie et les collĂšgues, ainsi que dâune mauvaise reconnaissance au travail, que de lâexposition aux contraintes physiques, aux horaires de travail et au type de contrat de travail. Conclusion La prĂ©vention du suicide liĂ© au travail doit passer par une rĂ©flexion sur lâorganisation du travail, les rapports sociaux au sein de lâentreprise et la promotion de la reconnaissance du travail rĂ©el
Medical-psychiatric units: shared care in mental health
This paper describes a highly unusual hospital unit that combines somatic and psychiatric approaches under the generic heading of a Medico-Psycho-Social Unit (MPSU) established at Angers University Hospital since 1996. The paper examines the value of a mixed approach while highlighting its limitations. The interest of the MPSU is that it provides a multidisciplinary, somatic and psychiatric approach on the same site. The joint expertise of medical and paramedical staff is required in cases where the assessment of the consultation-liaison services is not sufficient and in complex situations requiring the resources of an intensive care unit and specific medical and surgical specialties. Based on an established partnership and joint service provision, this type of unit is relatively uncommon both in France and abroad. However, the prevalence of somatic and organic comorbidity suggests that MPSUs are an innovative solution for the challenges of this type of care. Two clinical cases will be used as examples
Germline Mutations in FAN1 Cause Hereditary Colorectal Cancer by Impairing DNA Repair
Identification of genes associated with hereditary cancers facilitates management of patients with family histories of cancer. We performed exome sequencing of DNA from 3 individuals from a family with colorectal cancer who met the Amsterdam criteria for risk of hereditary nonpolyposis colorectal cancer. These individuals had mismatch repair-proficient tumors and each carried nonsense variant in the FANCD2/FANCI-associated nuclease 1 gene (FAN1), which encodes a nuclease involved in DNA inter-strand cross-link repair. We sequenced FAN1 in 176 additional families with histories of colorectal cancer and performed in vitro functional analyses of the mutant forms of FAN1 identified. We detected FAN1 mutations in approximately 3% of families who met the Amsterdam criteria and had mismatch repair-proficient cancers with no previously associated mutations. These findings link colorectal cancer predisposition to the Fanconi anemia DNA repair pathway, supporting the connection between genome integrity and cancer risk
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