351 research outputs found

    Field-level model approach to assess water and nutrient use efficiencies : WaterFARMING project. Report for deliverable 2.1

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    - Two models have been chosen for field-level assessment of crop yields and water- and nutrient use efficiencies: WOFOST and DAISY.- For WOFOST a post-doc (João Vasco Silva), who is an expert in this modelling approach has been added to the team. He is also the lead author of this report.- For DAISY, a brief description of the model and data requirements are provided as a guide for the consortium on data needs.- For WOFOST calibration and evaluation protocols and associated data needs have been worked out. Detailed templates have been developed and distributed in the team.- For sites in Germany and the Netherlands detailed experiments have been chosen that are ideally suited for model calibration and evaluation. The quality and detail of the data available is very high. In Denmark, data are available from a combined food and energy system for the modelling task.- Finding suitable experimental data for the other countries is ongoing, there being some challenges in this regard. In view of this we aim to find experimental data for at least one site in South Europe and one in North Africa

    Venous thrombosis in immunocompetent patients with acute cytomegalovirus infection: a complication that may be underestimated

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    In the present study, we retrospectively studied clinical and laboratory findings associated with cytomegalovirus (CMV) infection in immunocompetent patients. We focused on severe CMV infection. Among 38 patients, five had a severe form of infection: one had meningitis, one had symptomatic thrombocytopenia and three had venous thromboses with pulmonary embolism, a rarely described complication. CMV-induced thrombosis has been reported in immunocompromised patients such as transplant recipients and patients with AIDS. Recent case reports have also described thrombotic phenomena in immunocompetent patients with CMV infection. Our study suggests that venous thrombosis during acute CMV infection is an underestimated complication

    Effects of deletion of the Streptococcus pneumoniae lipoprotein diacylglyceryl transferase gene lgt on ABC transporter function and on growth in vivo

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    Lipoproteins are an important class of surface associated proteins that have diverse roles and frequently are involved in the virulence of bacterial pathogens. As prolipoproteins are attached to the cell membrane by a single enzyme, prolipoprotein diacylglyceryl transferase (Lgt), deletion of the corresponding gene potentially allows the characterisation of the overall importance of lipoproteins for specific bacterial functions. We have used a Δlgt mutant strain of Streptococcus pneumoniae to investigate the effects of loss of lipoprotein attachment on cation acquisition, growth in media containing specific carbon sources, and virulence in different infection models. Immunoblots of triton X-114 extracts, flow cytometry and immuno-fluorescence microscopy confirmed the Δlgt mutant had markedly reduced lipoprotein expression on the cell surface. The Δlgt mutant had reduced growth in cation depleted medium, increased sensitivity to oxidative stress, reduced zinc uptake, and reduced intracellular levels of several cations. Doubling time of the Δlgt mutant was also increased slightly when grown in medium with glucose, raffinose and maltotriose as sole carbon sources. These multiple defects in cation and sugar ABC transporter function for the Δlgt mutant were associated with only slightly delayed growth in complete medium. However the Δlgt mutant had significantly reduced growth in blood or bronchoalveolar lavage fluid and a marked impairment in virulence in mouse models of nasopharyngeal colonisation, sepsis and pneumonia. These data suggest that for S. pneumoniae loss of surface localisation of lipoproteins has widespread effects on ABC transporter functions that collectively prevent the Δlgt mutant from establishing invasive infection

    Impacts Of Grid Voltage Dip On The Performance Of Wind Turbine And Its Power Control During Fault Ride Through (Frt) The Case Study Of Doubly-Fed Induction Generator

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    Turbin angin yang dilengkapi dengan generator induksi makan ganda telah umumnya digunakan sebagai pembangkit tenaga angin yang terhubung ke jaringan publik sebagai komponen sistem pembangkit tenaga listrik. Turbin angin yang terhubung ke jaringan adalah sensitif terhadap gangguan Grid, terutama penurunan tegangan grid yang disebabkan oleh transien kesalahan sistem tenaga. DFIG dihubungi ke Grid melalui konduktor yang gunakan tegangan jaringan melalui transformator bantu untuk melakukan mekanisme untuk menyalakan/mematikan DFIG ke sistem transmisi daya atau jaringan publik. Di dalam tesis, dampak penurunan tegangan pada turbin angin DFIG dan turbin utama kontaktornya adalah Kepentingan penelitian ini. Studi ini berkonsentrasi pada simulasi proses menghubungkan generator DFIG ke Grid publik melalui AC Utamanya kontaktor dan pemodelan berbagai penurunan tegangan simetris dan asimetris, dan dampak kegagalan tersebut pada proses penyambungan generator ke listrik sistem melalui kontak kontaktor dan juga dampaknya terhadap kinerja generator

    Human neutrophil clearance of bacterial pathogens triggers anti-microbial gamma delta T cell responses in early infection

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    Human blood Vc9/Vd2 T cells, monocytes and neutrophils share a responsiveness toward inflammatory chemokines and are rapidly recruited to sites of infection. Studying their interaction in vitro and relating these findings to in vivo observations in patients may therefore provide crucial insight into inflammatory events. Our present data demonstrate that Vc9/Vd2 T cells provide potent survival signals resulting in neutrophil activation and the release of the neutrophil chemoattractant CXCL8 (IL-8). In turn, Vc9/Vd2 T cells readily respond to neutrophils harboring phagocytosed bacteria, as evidenced by expression of CD69, interferon (IFN)-c and tumor necrosis factor (TNF)-a. This response is dependent on the ability of these bacteria to produce the microbial metabolite (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMB-PP), requires cell-cell contact of Vc9/Vd2 T cells with accessory monocytes through lymphocyte function-associated antigen-1 (LFA-1), and results in a TNF-a dependent proliferation of Vc9/Vd2 T cells. The antibiotic fosmidomycin, which targets the HMB-PP biosynthesis pathway, not only has a direct antibacterial effect on most HMB-PP producing bacteria but also possesses rapid anti-inflammatory properties by inhibiting cd T cell responses in vitro. Patients with acute peritoneal-dialysis (PD)-associated bacterial peritonitis – characterized by an excessive influx of neutrophils and monocytes into the peritoneal cavity – show a selective activation of local Vc9/Vd2 T cells by HMB-PP producing but not by HMB-PP deficient bacterial pathogens. The cd T celldriven perpetuation of inflammatory responses during acute peritonitis is associated with elevated peritoneal levels of cd T cells and TNF-a and detrimental clinical outcomes in infections caused by HMB-PP positive microorganisms. Taken together, our findings indicate a direct link between invading pathogens, neutrophils, monocytes and microbe-responsive cd T cells in early infection and suggest novel diagnostic and therapeutic approaches.Martin S. Davey, Chan-Yu Lin, Gareth W. Roberts, Sinéad Heuston, Amanda C. Brown, James A. Chess, Mark A. Toleman, Cormac G.M. Gahan, Colin Hill, Tanya Parish, John D. Williams, Simon J. Davies, David W. Johnson, Nicholas Topley, Bernhard Moser and Matthias Eber
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