102 research outputs found

    On the First Order Cohomology of Infinite-Dimensional Unitary Groups

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    The irreducible unitary highest weight representations (πλ,Hλ)(\pi_\lambda,\mathcal{H}_\lambda) of the group U()U(\infty), which is the countable direct limit of the compact unitary groups U(n)U(n), are classified by the orbits of the weights λZN\lambda \in \mathbb{Z}^{\mathbb{N}} under the Weyl group S(N)S_{(\mathbb{N})} of finite permutations. Here, we determine those weights λ\lambda for which the first cohomology space H1(U(),πλ,Hλ)H^1(U(\infty),\pi_\lambda,\mathcal{H}_\lambda) vanishes. For finitely supported λ0\lambda \neq 0, we find that the first cohomology space H1(U(),πλ,Hλ)H^1(U(\infty),\pi_\lambda,\mathcal{H}_\lambda) never vanishes. For these λ\lambda, the highest weight representations extend to norm-continuous irreducible representations of the full unitary group U(H)U(\mathcal{H}) (for H:=2(N,C)\mathcal{H}:= \ell^2(\mathbb{N},\mathbb{C})) endowed with the strong operator topology and to norm-continuous representations of the unitary groups Up(H)U_p(\mathcal{H}) (p[1,]p\in [1,\infty]) consisting of those unitary operators gU(H)g\in U(\mathcal{H}) for which g1g-\mathbb{1} is of ppth Schatten class. However, not every 1-cocycle on U()U(\infty) automatically extends to one on these unitary groups, so we may not conclude that the first cohomology spaces of the extended representations are non-vanishing. On the contrary, for the groups U(H)U(\mathcal{H}) and U(H)U_\infty(\mathcal{H}), all first cohomology spaces vanish. This is different for the groups Up(H)U_p(\mathcal{H}) with 1p<1\leq p <\infty, where only the natural representation on H\mathcal{H} and on its dual have vanishing first cohomology spaces.Comment: To appear in Annales de l'Institut Fourie

    Antibodies and IL-3 support helminth-induced basophil expansion

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    Basophils are powerful mediators of Th2 immunity and are present in increased numbers during allergic inflammation and helminth infection. Despite their ability to potentiate Th2 immunity the mechanisms regulating basophil development remain largely unknown. We have found a unique role for isotype-switched antibodies in promoting helminth-induced basophil production following infection of mice with Heligmosomoides polygyrus bakeri or Nippostrongylus brasiliensis. H. polygyrus bakeri-induced basophil expansion was found to occur within the bone marrow, and to a lesser extent the spleen, and was IL-3 dependent. IL-3 was largely produced by CD4+CD49b+NK1.1− effector T cells at these sites, and required the IL-4Rα chain. However, antibody-deficient mice exhibited defective basophil mobilization despite intact T-cell IL-3 production, and supplementation of mice with immune serum could promote basophilia independently of required IL-4Rα signaling. Helminth-induced eosinophilia was not affected by the deficiency in isotype-switched antibodies, suggesting a direct effect on basophils rather than through priming of Th2 responses. Although normal type 2 immunity occurred in the basopenic mice following primary infection with H. polygyrus bakeri, parasite rejection following challenge infection was impaired. These data reveal a role for isotype-switched antibodies in promoting basophil expansion and effector function following helminth infection

    Molecular profiling of signet ring cell colorectal cancer provides a strong rationale for genomic targeted and immune checkpoint inhibitor therapies

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    We would like to thank all patients whose samples were used in this study. We are also thankful to the Northern Ireland Biobank and Grampian Biorepository for providing us with tissue blocks and patient data; and Dr HG Coleman (Queen’s University Belfast) for her advice on statistical analyses. This work has been carried out with financial support from Cancer Research UK (grant: C11512/A18067), Experimental Cancer Medicine Centre Network (grant: C36697/A15590 from Cancer Research UK and the NI Health and Social Care Research and Development Division), the Sean Crummey Memorial Fund and the Tom Simms Memorial Fund. The Northern Ireland Biobank is funded by HSC Research and Development Division of the Public Health Agency in Northern Ireland and Cancer Research UK through the Belfast CRUK Centre and the Northern Ireland Experimental Cancer Medicine Centre; additional support was received from Friends of the Cancer Centre. The Northern Ireland Molecular Pathology Laboratory which is responsible for creating resources for the Northern Ireland Biobank has received funding from Cancer Research UK, Friends of the Cancer Centre and Sean Crummey Foundation.Peer reviewedPublisher PD

    Adjuvant Radiotherapy in Patients with Squamous Cell Carcinoma of the Oral Cavity or Oropharynx and Solitary Ipsilateral Lymph Node Metastasis (pN1) : A Prospective Multicentric Cohort Study

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    (1) Background: Evaluation of impact of adjuvant radiation therapy (RT) in patients with oral squamous cell carcinoma of the oral cavity/oropharynx (OSCC) of up to 4 cm (pT1/pT2) and solitary ipsilateral lymph node metastasis (pN1). A non-irradiated group with clinical follow-up was chosen for control, and survival and quality of life (QL) were compared; (2) Methods: This prospective multicentric comprehensive cohort study included patients with resected OSCC (pT1/pT2, pN1, and cM0) who were allocated into adjuvant radiation therapy (RT) or observation. The primary endpoint was overall survival. Secondary endpoints were progression-free survival and QL after surgery; (3) Results: Out of 27 centers, 209 patients were enrolled with a median follow-up of 3.4 years. An amount of 137 patients were in the observation arm, and 72 received adjuvant irradiation. Overall survival did not differ between groups (hazard ratio (HR) 0.98 [0.55–1.73], p = 0.94). There were fewer neck metastases (HR 0.34 [0.15–0.77]; p = 0.01), as well as fewer local recurrences (HR 0.41 [0.19–0.89]; p = 0.02) under adjuvant RT. For QL, irradiated patients showed higher values for the symptom scale pain after 0.5, two, and three years (all p < 0.05). After six months and three years, irradiated patients reported higher symptom burdens (impaired swallowing, speech, as well as teeth-related problems (all p < 0.05)). Patients in the RT group had significantly more problems with mouth opening after six months, one, and two years (p < 0.05); (4) Conclusions: Adjuvant RT in patients with early SCC of the oral cavity and oropharynx does not seem to influence overall survival, but it positively affects progression-free survival. However, irradiated patients report a significantly decreased QL up to three years after therapy compared to the observation group

    MALDI Profiling of Human Lung Cancer Subtypes

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    Proteomics is expected to play a key role in cancer biomarker discovery. Although it has become feasible to rapidly analyze proteins from crude cell extracts using mass spectrometry, complex sample composition hampers this type of measurement. Therefore, for effective proteome analysis, it becomes critical to enrich samples for the analytes of interest. Despite that one-third of the proteins in eukaryotic cells are thought to be phosphorylated at some point in their life cycle, only a low percentage of intracellular proteins is phosphorylated at a given time.In this work, we have applied chromatographic phosphopeptide enrichment techniques to reduce the complexity of human clinical samples. A novel method for high-throughput peptide profiling of human tumor samples, using Parallel IMAC and MALDI-TOF MS, is described. We have applied this methodology to analyze human normal and cancer lung samples in the search for new biomarkers. Using a highly reproducible spectral processing algorithm to produce peptide mass profiles with minimal variability across the samples, lineal discriminant-based and decision tree–based classification models were generated. These models can distinguish normal from tumor samples, as well as differentiate the various non–small cell lung cancer histological subtypes.A novel, optimized sample preparation method and a careful data acquisition strategy is described for high-throughput peptide profiling of small amounts of human normal lung and lung cancer samples. We show that the appropriate combination of peptide expression values is able to discriminate normal lung from non-small cell lung cancer samples and among different histological subtypes. Our study does emphasize the great potential of proteomics in the molecular characterization of cancer

    Performance assessment of nitrate leaching models for highly vulnerable soils used in low-input farming based on lysimeter data

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    [EN] The agricultural sector faces the challenge of ensuring food security without an excessive burden on the environment. Simulationmodels provide excellent instruments for researchers to gainmore insight into relevant processes and best agricultural practices and provide tools for planners for decision making support. The extent to which models are capable of reliable extrapolation and prediction is important for exploring new farming systems or assessing the impacts of future land and climate changes. A performance assessmentwas conducted by testing six detailed state-of-the-artmodels for simulation of nitrate leaching (ARMOSA, COUPMODEL, DAISY, EPIC, SIMWASER/STOTRASIM, SWAP/ANIMO) for lysimeter data of the Wagna experimental field station in Eastern Austria, where the soil is highly vulnerable to nitrate leaching. Three consecutive phases were distinguished to gain insight in the predictive power of themodels: 1) a blind test for 2005 2008 in which only soil hydraulic characteristics, meteorological data and information about the agricultural management were accessible; 2) a calibration for the same period in which essential information on field observations was additionally available to the modellers; and 3) a validation for 2009 2011 with the corresponding type of data available as for the blind test. A set of statistical metrics (mean absolute error, root mean squared error, index of agreement,model efficiency, root relative squared error, Pearson's linear correlation coefficient) was applied for testing the results and comparing the models. None of the models performed good for all of the statistical metrics. Models designed for nitrate leaching in high-input farming systems had difficulties in accurately predicting leaching in low-input farming systems that are strongly influenced by the retention of nitrogen in catch crops and nitrogen fixation by legumes. An accurate calibration does not guarantee a good predictive power of the model. Nevertheless all models were able to identify years and crops with high- and low-leaching rates.This research was made possible by the GENESIS project of the EU 7th Framework Programme (Project No. 226536; FP7-ENV-2008-1). We are grateful for the experimental data provided by Joanneum Raum (Graz, Austria). The modelling team of Democritus University of Thrace would like to thank Per-Erik Jansson (Royal Institute of Technology, Stockholm, Sweden) for his valuable help during the application of Coup Model.Groenendijk, P.; Heinen, M.; Klammler, G.; Fank, J.; Kupfersberger, H.; Pisinaras, V.; Gemitzi, A.... (2014). Performance assessment of nitrate leaching models for highly vulnerable soils used in low-input farming based on lysimeter data. Science of the Total Environment. 499:463-480. https://doi.org/10.1016/j.scitotenv.2014.07.002S46348049

    Towards long-term standardised carbon and greenhouse gas observations for monitoring Europe's terrestrial ecosystems : a review

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    Research infrastructures play a key role in launching a new generation of integrated long-term, geographically distributed observation programmes designed to monitor climate change, better understand its impacts on global ecosystems, and evaluate possible mitigation and adaptation strategies. The pan-European Integrated Carbon Observation System combines carbon and greenhouse gas (GHG; CO2, CH4, N2O, H2O) observations within the atmosphere, terrestrial ecosystems and oceans. High-precision measurements are obtained using standardised methodologies, are centrally processed and openly available in a traceable and verifiable fashion in combination with detailed metadata. The Integrated Carbon Observation System ecosystem station network aims to sample climate and land-cover variability across Europe. In addition to GHG flux measurements, a large set of complementary data (including management practices, vegetation and soil characteristics) is collected to support the interpretation, spatial upscaling and modelling of observed ecosystem carbon and GHG dynamics. The applied sampling design was developed and formulated in protocols by the scientific community, representing a trade-off between an ideal dataset and practical feasibility. The use of open-access, high-quality and multi-level data products by different user communities is crucial for the Integrated Carbon Observation System in order to achieve its scientific potential and societal value.Peer reviewe
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