44 research outputs found
Automatic tuning of PI controllers for an irrigation canal pool
The paper presents a method to automatically tune decentralized Proportional Integral (PI) controllers for an irrigation canal pool. The Auto Tune Variation (ATV) method is based on a relay experiment, which leads to small amplitude oscillations of the canal pool. The test signal is automatically generated by a relay inserted in the feedback loop. The method automatically estimates the ultimate gain and ultimate frequency of the pool, which can be used to tune P, PI or PID controllers. This method does not require advanced automatic control knowledge and is implemented in SIC software, developed by Cemagref, which also incorporates a SCADA module for real-time control. The ATV method is evaluated by simulations and experiments on a real irrigation canal located in the South of France, for local upstream, local downstream and distant downstream controller tuning
Static and dynamic data reconciliation for an irrigation canal
International audienceThis paper deals with the problem of fault detection and isolation in irrigation canals. We develop a method which combines static and dynamic data reconciliation for the validation of measurements, detection and isolation of sensors and actuator faults and reconstruction of missing data. Static data reconciliation uses static models at a regulation gate to validate measurements and detect sensor and actuator faults. It also enabled us to detect a drift in the stage discharge rating curve. The dynamic data reconciliation uses additional measurements and a dynamic model of the canal in order to validate measurements and detect faults and withdrawals. The combination of the two methods allowed us to distinguish between withdrawals and faults. Both methods are evaluated on measurements from a real irrigation canal located in the South of France
Interactions between microplastics and benthic biofilms in fluvial ecosystems: Knowledge gaps and future trends
Plastics, especially microplastics (<5 mm in length), are anthropogenic polymer particles that have been detected in almost all environments. Microplastics are extremely persistent pollutants and act as long-lasting reactive surfaces for additives, organic matter, and toxic substances. Biofilms are microbial assemblages that act as a sink for particulate matter, including microplastics. They are ubiquitous in freshwater ecosystems and provide key services that promote biodiversity and help sustain ecosystem function. Here, we provide a conceptual framework to describe the transient storage of microplastics in fluvial biofilm and develop hypotheses to help explain how microplastics and biofilms interact in fluvial ecosystems. We identify lines of future research that need to be addressed to better manage microplastics and biofilms, including how the sorption and desorption of environmental contaminants in microplastics affect biofilms and how microbial exchange between microplastics and the biofilm matrix affects biofilm characteristics like antibiotic resistance, speciation, biodiversity, species composition, and function. We also address the uptake mechanisms of microplastics by consumers and their propagation through the food web
Epithelial and dendritic cells in the thymic medulla promote CD4(+)Foxp3(+) regulatory T cell development via the CD27-CD70 pathway
This work was supported by grants NKI 2004-3087 and NKI 2008-2023 from
the Dutch Cancer Society to J. Borst, European Molecular Biology Organization
long-term fellowships to J.M. Coquet and J.C. Ribot, a Rubicon (The Netherlands
Organisation for Scientific Research [NWO]) fellowship to J.M. Coquet, and a
Fundação para a Ciência e Tecnologia project grant (PTDC/SAU-MII/104158/2008)
and a European Research Council starting grant (StG260352) to B. Silva-Santos.
J.F. Neves is funded by the Fundação para a Ciência e Technologia of Portugal;
D.J. Pennington is funded by the Wellcome Trust
A population of proinflammatory T cells coexpresses αβ and γδ T cell receptors in mice and humans
T cells are classically recognized as distinct subsets that express αβ or γδ TCRs. We identify a novel population of T cells that coexpress αβ and γδ TCRs in mice and humans. These hybrid αβ-γδ T cells arose in the murine fetal thymus by day 16 of ontogeny, underwent αβ TCR–mediated positive selection into CD4+ or CD8+ thymocytes, and constituted up to 10% of TCRδ+ cells in lymphoid organs. They expressed high levels of IL-1R1 and IL-23R and secreted IFN-γ, IL-17, and GM-CSF in response to canonically restricted peptide antigens or stimulation with IL-1β and IL-23. Hybrid αβ-γδ T cells were transcriptomically distinct from conventional γδ T cells and displayed a hyperinflammatory phenotype enriched for chemokine receptors and homing molecules that facilitate migration to sites of inflammation. These proinflammatory T cells promoted bacterial clearance after infection with Staphylococcus aureus and, by licensing encephalitogenic Th17 cells, played a key role in the development of autoimmune disease in the central nervous system
TCR signal strength controls thymic differentiation of discrete proinflammatory gamma delta T cell subsets
The mouse thymus produces discrete gd T cell subsets that make either interferon-g (IFN-g) or interleukin 17 (IL-17), but the role of the T cell antigen receptor (TCR) in this developmental process remains controversial. Here we show that Cd3g+/− Cd3d+/− (CD3 double-haploinsufficient (CD3DH)) mice have reduced TCR expression and signaling strength on gd T cells. CD3DH mice had normal numbers and phenotypes of ab thymocyte subsets, but impaired differentiation of fetal Vg6+ (but not Vg4+) IL-17- producing gd T cells and a marked depletion of IFN-g-producing CD122+ NK1.1+ gd T cells throughout ontogeny. Adult CD3DH mice showed reduced peripheral IFN-g+ gd T cells and were resistant to experimental cerebral malaria. Thus, TCR signal strength within specific thymic developmental windows is a major determinant of the generation of proinflammatory gd T cell subsets and their impact on pathophysiology
Epigenetic and transcriptional signatures of stable versus plastic differentiation of proinflammatory gd T cell subsets
Two distinct subsets of γδ T cells that produce interleukin 17 (IL-17) (CD27(-) γδ T cells) or interferon-γ (IFN-γ) (CD27(+) γδ T cells) develop in the mouse thymus, but the molecular determinants of their functional potential in the periphery remain unknown. Here we conducted a genome-wide characterization of the methylation patterns of histone H3, along with analysis of mRNA encoding transcription factors, to identify the regulatory networks of peripheral IFN-γ-producing or IL-17-producing γδ T cell subsets in vivo. We found that CD27(+) γδ T cells were committed to the expression of Ifng but not Il17, whereas CD27(-) γδ T cells displayed permissive chromatin configurations at loci encoding both cytokines and their regulatory transcription factors and differentiated into cells that produced both IL-17 and IFN-γ in a tumor microenvironment
Methodologies for in vitro and in vivo evaluation of efficacy of antifungal and antibiofilm agents and surface coatings against fungal biofilms
KT acknowledges receipt of a mandate of Industrial Research Fund (IOFm/05/022). JB acknowledges funding from the European Research Council Advanced Award 3400867/RAPLODAPT and the Israel Science Foundation grant # 314/13 (www.isf.il). NG acknowledges the Wellcome Trust and MRC for funding. CD acknowledges funding from the Agence Nationale de Recherche (ANR-10-LABX-62-IBEID). CJN acknowledges funding from the National Institutes of Health R35GM124594 and R21AI125801. AW is supported by the Wellcome Trust Strategic Award (grant 097377), the MRC Centre for Medical Mycology (grant MR/N006364/1) at the University of Aberdeen MaCA: outside this study MaCA has received personal speaker’s honoraria the past five years from Astellas, Basilea, Gilead, MSD, Pfizer, T2Candida, and Novartis. She has received research grants and contract work paid to the Statens Serum Institute from Astellas, Basilea, Gilead, MSD, NovaBiotics, Pfizer, T2Biosystems, F2G, Cidara, and Amplyx. CAM acknowledges the Wellcome Trust and the MRC MR/N006364/1. PVD, TC and KT acknowledge the FWO research community: Biology and ecology of bacterial and fungal biofilms in humans (FWO WO.009.16N). AAB acknowledges the Deutsche Forschungsgemeinschaft – CRC FungiNet.Peer reviewedPublisher PD
Using RNA-Seq for gene identification, polymorphism detection and transcript profiling in two alfalfa genotypes with divergent cell wall composition in stems
<p>Abstract</p> <p>Background</p> <p>Alfalfa, [<it>Medicago sativa </it>(L.) sativa], a widely-grown perennial forage has potential for development as a cellulosic ethanol feedstock. However, the genomics of alfalfa, a non-model species, is still in its infancy. The recent advent of RNA-Seq, a massively parallel sequencing method for transcriptome analysis, provides an opportunity to expand the identification of alfalfa genes and polymorphisms, and conduct in-depth transcript profiling.</p> <p>Results</p> <p>Cell walls in stems of alfalfa genotype 708 have higher cellulose and lower lignin concentrations compared to cell walls in stems of genotype 773. Using the Illumina GA-II platform, a total of 198,861,304 expression sequence tags (ESTs, 76 bp in length) were generated from cDNA libraries derived from elongating stem (ES) and post-elongation stem (PES) internodes of 708 and 773. In addition, 341,984 ESTs were generated from ES and PES internodes of genotype 773 using the GS FLX Titanium platform. The first alfalfa (<it>Medicago sativa</it>) gene index (MSGI 1.0) was assembled using the Sanger ESTs available from GenBank, the GS FLX Titanium EST sequences, and the <it>de novo </it>assembled Illumina sequences. MSGI 1.0 contains 124,025 unique sequences including 22,729 tentative consensus sequences (TCs), 22,315 singletons and 78,981 pseudo-singletons. We identified a total of 1,294 simple sequence repeats (SSR) among the sequences in MSGI 1.0. In addition, a total of 10,826 single nucleotide polymorphisms (SNPs) were predicted between the two genotypes. Out of 55 SNPs randomly selected for experimental validation, 47 (85%) were polymorphic between the two genotypes. We also identified numerous allelic variations within each genotype. Digital gene expression analysis identified numerous candidate genes that may play a role in stem development as well as candidate genes that may contribute to the differences in cell wall composition in stems of the two genotypes.</p> <p>Conclusions</p> <p>Our results demonstrate that RNA-Seq can be successfully used for gene identification, polymorphism detection and transcript profiling in alfalfa, a non-model, allogamous, autotetraploid species. The alfalfa gene index assembled in this study, and the SNPs, SSRs and candidate genes identified can be used to improve alfalfa as a forage crop and cellulosic feedstock.</p