146 research outputs found
Soil redistribution in rural catchment: how fifty years old soil survey can help model improvement
In a context of high urbanization’s pressure in rural zones, landscape modelling of erosion opens interesting perspectives in land use planning. In most cases, validation data are the weak point. In this study, we present how fifty years old soil observations can help progressing towards a more accurate validation of such modelling in rural areas.
As of 1947, a comprehensive systematic survey of the Belgian soil cover was initiated. Field observations were done every 75 meters by soil auger to a standard depth of 125cm (if possible). Map units were delineated on cadastral field survey maps at scale 1:5,000, based on auger observations and landscape context, then generalised on the 1:10,000 topographic base map for a publication at 1:20,000 scale. The legend of the map includes more than 6,000 different soil types and variants. More recently, the Walloon part of this map was digitalised to produce the Digital Soil Map of Wallonia (DSMW).
A 10m resolution DEM was build up in 2009. Its RMSE is 0.8m. Soil erodibility and runoff production maps were derived at the same resolution. A land use map exists at 1:10,000 scale since 2005 and is updated yearly.
We applied the USPED model (Unit Stream Power - based Erosion Deposition) (Moore and Burch, 1986) in a small watershed where first soil observations took place in 1956. New soil observations were done in 2010. The watershed is completely included in a cultivated area.
The model was applied considering a transport capacity limitation proposed by Mitasova and Mitas (1996). Furthermore, we slightly modified it, in order to take into account recent advances in RUSLE factors computations like LS computation proposed by Desmet and Govers (1996) and Nearing (1997).
The spatial distribution of erosion and deposition area produced by the model on the basis of the current DEM is consistent with a comparison between old and recent pedological observations. Furthermore, a comparison between horizons’ thickness in 1956 and 2010 gives spatially distributed quantitative information on erosion and deposition. Nevertheless, some uncertainties remain since the pedological descriptions are based on thickness classes, due to the variability of soil cartographical units, and since the current DEM is itself affected by an uncertainty on the elevation value. Future research will then focus on more accurate elevation data as starting point and then it will become conceivable to model the evolution of watershed elevation including land use and other local anthropogenic structures like hedgerows, ditches or grass strips
Cadmium triggers an integrated reprogramming of the metabolism of Synechocystis PCC6803, under the control of the Slr1738 regulator
<p>Abstract</p> <p>Background</p> <p>Cadmium is a persistent pollutant that threatens most biological organisms, including cyanobacteria that support a large part of the biosphere. Using a multifaceted approach, we have investigated the global responses to Cd and other relevant stresses (H<sub>2</sub>O<sub>2 </sub>and Fe) in the model cyanobacterium <it>Synechocystis </it>PCC6803.</p> <p>Results</p> <p>We found that cells respond to the Cd stress in a two main temporal phases process. In the "early" phase cells mainly limit Cd entry through the negative and positive regulation of numerous genes operating in metal uptake and export, respectively. As time proceeds, the number of responsive genes increases. In this "massive" phase, Cd downregulates most genes operating in (i) photosynthesis (PS) that normally provides ATP and NADPH; (ii) assimilation of carbon, nitrogen and sulfur that requires ATP and NAD(P)H; and (iii) translation machinery, a major consumer of ATP and nutrients. Simultaneously, many genes are upregulated, such as those involved in Fe acquisition, stress tolerance, and protein degradation (crucial to nutrients recycling). The most striking common effect of Cd and H<sub>2</sub>O<sub>2 </sub>is the disturbance of both light tolerance and Fe homeostasis, which appeared to be interdependent. Our results indicate that cells challenged with H<sub>2</sub>O<sub>2 </sub>or Cd use different strategies for the same purpose of supplying Fe atoms to Fe-requiring metalloenzymes and the SUF machinery, which synthesizes or repairs Fe-S centers. Cd-stressed cells preferentially breakdown their Fe-rich PS machinery, whereas H<sub>2</sub>O<sub>2</sub>-challenged cells preferentially accelerate the intake of Fe atoms from the medium.</p> <p>Conclusion</p> <p>We view the responses to Cd as an integrated "Yin Yang" reprogramming of the whole metabolism, we found to be controlled by the Slr1738 regulator. As the Yin process, the ATP- and nutrients-sparing downregulation of anabolism limits the poisoning incorporation of Cd into metalloenzymes. As the compensatory Yang process, the PS breakdown liberates nutrient assimilates for the synthesis of Cd-tolerance proteins, among which we found the Slr0946 arsenate reductase enzyme.</p
Genome-Wide Protein Interaction Screens Reveal Functional Networks Involving Sm-Like Proteins
Prevention of ventilator‑associated pneumonia by noble metal coating of endotracheal tubes: a multi‑center, randomized, double‑blind study
BACKGROUND: Ventilator-associated pneumonia (VAP) causes increased mortality, prolonged hospital stay and increased healthcare costs. Prevention of VAP in intensive care units (ICUs) is currently based on several measures, and application of noble metal coating on medical devices has been shown to inhibit the bacterial adherence of microorganisms to the surface. The objective of this study was to evaluate the potential benefit of noble metal coating of endotracheal tubes for the prevention of VAP. METHODS: This was a multi-center, randomized, controlled, double-blind, prospective study including ventilated patients from nine ICUs from four hospital sites in Belgium. Patients were randomly intubated with identical appearing noble metal alloy (NMA) coated (NMA-coated group) or non-coated (control group) endotracheal tubes (ETT). Primary endpoint was the incidence of VAP. Secondary endpoints were the proportion of antibiotic days during ICU stay and tracheal colonization by pathogenic bacteria. RESULTS: In total, 323 patients were enrolled, 168 in the NMA-coated group and 155 in the control group. During ventilation, VAP occurred in 11 patients (6.5%) in the NMA-coated group and in 18 patients (11.6%) in the control group (p  = 0.11). A higher delay in VAP occurrence was observed in the NMA-coated group compared with the control group by Cox proportional hazards regression analysis (HR 0.41, 95% CI 0.19–0.88, p  = 0.02). The number of antibiotic days was 58.8% of the 1,928 ICU days in the NMA-coated group and 65.4% of the 1774 ICU days in the control group (p  = 0.06). Regarding tracheal colonization, bacteria occurred in 38 of 126 patients in the NMA-coated group (30.2%) and in 37 of 109 patients in the control group (33.9%) (p  = 0.57). CONCLUSIONS: This study provides preliminary evidence to support the benefit of noble metal coating in the prevention of VAP. A confirmatory study in a larger population would be valuable. Trial registration: Clinical trial number: NCT04242706 (http://www.clinicaltrials.gov
Can noble metal coating reduce the incidence of ventilator associated pneumoniae (VAP): a multicenter double blind randomized pilot study
peer reviewedThis is the first report of a randomized double blind
study with Bactiguard tubes which will allow to define the number of
patients for a confirmatory larger study
Bespuiting van tomaten met Plantfood (19-22-16), 1953
<p><b>Copyright information:</b></p><p>Taken from "Cadmium triggers an integrated reprogramming of the metabolism of PCC6803, under the control of the Slr1738 regulator"</p><p>http://www.biomedcentral.com/1471-2164/8/350</p><p>BMC Genomics 2007;8():350-350.</p><p>Published online 2 Oct 2007</p><p>PMCID:PMC2190772.</p><p></p> indicated durations on solid BG11 medium with or without HO(3 mM), CdSO(50 μM), Co(NO)(350 μM), (NH)FeHCHO(350 μM) or ZnSO(350 μM or 776 μM). The spectra (normalized to light scattering at 800 nm) are displayed in panels A to F. These experiments were repeated three to five times
French Roadmap for complex Systems 2008-2009
This second issue of the French Complex Systems Roadmap is the outcome of the
Entretiens de Cargese 2008, an interdisciplinary brainstorming session
organized over one week in 2008, jointly by RNSC, ISC-PIF and IXXI. It
capitalizes on the first roadmap and gathers contributions of more than 70
scientists from major French institutions. The aim of this roadmap is to foster
the coordination of the complex systems community on focused topics and
questions, as well as to present contributions and challenges in the complex
systems sciences and complexity science to the public, political and industrial
spheres
Outcome-based determination of optimal pyrosequencing assay for MGMT methylation detection in glioblastoma patients
Soil mapping in Belgium: historical overview and presentation of the current work on valorisation and revision of the Digital Soil Map of Wallonia
Depuis quelques années, on assiste à un regain d’intérêt sur les sols et leurs propriétés, en relation avec une prise de conscience environnementale accrue. La protection des sols est ainsi devenue l’objet d’initiatives réglementaires au niveau européen. Cette communication propose un bref historique de la cartographie des sols en Belgique et présente les travaux de valorisation et de révision de la Carte des Sols menés au sein de notre équipe de recherche-développement. La Belgique fut un des premiers pays à s’être doté d’une carte des sols à grande échelle (1/20 000) sur la totalité de son territoire. L’article commente les étapes de sa réalisation et ses caractéristiques. S’étalant de 1947 à 1991, ce programme ambitieux délivra divers produits en marge de cette carte. Face à une demande accrue d’informations sur les sols et au développement des systèmes d’information géographiques, la partie wallonne de la carte a été numérisée dans le cadre du Projet de Cartographie Numérique des Sols de Wallonie (PCNSW). La Carte Numérique des Sols de Wallonie et sa légende unique ont ensuite été valorisées au travers d’un certain nombre de produits dérivés dont une sélection est brièvement commentée. Si l’utilisation de la Carte des Sols et les applications dont elle fait l’objet dépassent de loin les objectifs initiaux d’augmentation des productions agricoles, elle ne répond cependant pas toujours aux demandes actuelles, au regard des enjeux environnementaux et des législations actuelles et futures, tant au niveau régional qu’européen. Faisant écho à ce constat, les travaux menés actuellement par l’équipe de révision de la Carte Numérique des Sols de Wallonie sont brièvement présentés, à travers une description de son cadre méthodologique et technique. Le crédo des travaux menés étant que la Carte des Sols, en tant qu’outil d’intégration, de structuration et de cadrage de l’information pédologique, doit devenir de plus en plus le fondement de Systèmes Régionaux d’Information sur les Sols et leurs propriétés.Over the past few years, there has been growing concern about soils and their properties, thanks to greater environmental awareness. Consequently, existing documents on soil are valuable in risk assessment and for the research of well-adapted solutions. In this context, this paper reviews the main stages of soil mapping in Belgium and presents current works to valorize the Digital Soil Map of Wallonia and update associated databases. Belgium is among the first countries to be completely covered by a detailed soil map (1:20,000). The origin of the Soil Map of Belgium, its realisation between 1947 and 1991, the principles and characteristics as well as the related products are described. But since its publication, due to the increasing need of soil information and thanks to the development of geographical information systems the Walloon part of the map was digitalised between 2000 and 2003 by the Digital Soil Map of Wallonia (DSMW) Project. From this early action at regional level, a selection of immediately derived products is presented and briefly commented. However, if these products go beyond the initial objective of agricultural production increase, they do not always meet the environmental challenges nor the future legislation at European, national and regional levels. To fill this gap, the recent tasks carried out by the DMSW team are presented through a description of their methodological and technical framework. The long-term objective is to build Regional Soil Information Systems based on the use of the Digital Soil Map of Wallonia as a tool of integration, structuring and referencing of pedological information
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