576 research outputs found

    Landscape level characterization of seasonal floodplains under community based aquaculture: illustrating a case of the Ganges and the Mekong Delta

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    The project 'Community-based Fish Culture in Seasonal Floodplains' (henceforward the community-based fish culture project), CGIAR Challenge Program on Water and Food, aims to enhance fish production in seasonal floodplains to improve and sustain rural livelihoods in Bangladesh, Cambodia, China, Mali and Vietnam. Based on the premise that production from these water bodies could be enhanced by stocking locally important fish species, the community-based fish culture project seeks to develop technologies and institutional arrangements to support collective fish culture in the flood season. The current report provides a landscape level characterization of seasonal floodplains in two of these areas. We compare the Ganges seasonal floodplain agro-ecology in Bangladesh to that in the Mekong Delta of Cambodia and Vietnam. In both areas the project has been under implementation since the outset, but has met with contrasting resultsFlood plains, Aquaculture, Remote sensing

    Impacts of technological interventions on fish production and biodiversity of seasonal floodplains in Bangladesh

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    The Community-based Fish Culture in Seasonal Floodplains and Irrigation Systems (CBFC) project is a five year research project supported by the Challenge Program on Water and Food (CPWF), with the aim of increasing productivity of seasonally occurring water bodies through aquaculture. The project has been implemented in Bangladesh, Cambodia, China, Mali and Vietnam, where technical and institutional options for community based aquaculture have been tested. The project began in 2005 and was completed in March 2010. The objective of the study was to determine the impacts of technological interventions in the floodplains on fish yield and biodiversity benefiting the poor fisher folk and other community people. Technological interventions for fish culture in the floodplains included (a) the installation of low-cost large meshed bamboo fencing at water inlet and outlet points, and setting of ring culverts for maintaining suitable levels of water for fish culture without hampering the production of rice in the upland areas of the floodplains (b) stocking of larger fingerlings at suitable stocking densities of endemic (rohu, catla, mrigal) and exotic (silver carp, bighead carp, common carp/mirror carp) species at 31-48 kg/ha (c) post stocking management; use of extra fencing during over flooding and mobile guarding using boats (d) harvesting management; regulations in harvest for certain period, use of multiple harvesting techniques. These interventions were carried out through CB participation with initial technological and financial support from the Challenge Program Project (CP35).Flood plains, Freshwater aquaculture

    Neuroticism and responses to social comparison among cancer patients

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    The present study examined how the effects of three audiotapes containig different types of social comparison information on the mood of cancer patients depended on the level of neuroticism. On the procedural tape, a man and woman discussed the process of radiation therapy, on the emotion tape, they focussed on emotional reactions to their illness and treatment, while on the coping tape they focussed on the way they had been coping. A validation study among 115 students showed that the tapes were perceived as they were intended. The main study was conducted among 226 patients who were about to undergo radiation therapy. Compared to patients in the control group, as patients were higher in neuroticism, they reported less negative mood after listening to the procedural and the coping tape. Furthermore, as patients were higher in neuroticism, they reported less negative mood after listening to the coping tape than to the emotion tape. Copyright (C) 2009 John Wiley & Sons, Ltd

    Enhanced recruitment of genetically modified CX3CR1-positive human T cells into Fractalkine/CX3CL1 expressing tumors: importance of the chemokine gradient.

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    BACKGROUND: Adoptive T-cell based immunotherapies constitute a promising approach to treat cancer, however, a major problem is to obtain effective and long-lasting anti-tumor responses. Lack of response may be due to insufficient trafficking of specific T cells to tumors. A key requirement for efficient migration of cytotoxic T cells is that they express chemokine receptors that match the chemokines produced by tumor or tumor-associated cells. METHODS: In this study, we investigated whether the in vivo tumor trafficking of activated T cells could be enhanced by the expression of the chemokine receptor CX3CR1. Two human colorectal cancer cell lines were used to set up a xenograft tumor model in immunodeficient mice; the NCI-H630, constitutively expressing the chemokine ligand CX3CL1 (Fractalkine), and the RKO cell line, transduced to express CX3CL1. RESULTS: Human primary T cells were transduced with the receptor CX3CR1-eGFP. Upon in vivo adoptive transfer of genetically modified CX3CR1-T cells in mice bearing NCI-H630 tumors, enhanced lymphocyte migration and tumor trafficking were observed, compared to mice receiving Mock-T cells, indicating improved homing ability towards ligand-expressing tumor cells. Furthermore, significant inhibition of tumor growth was found in mice receiving modified CX3CR1-T cells. In contrast, tumors formed by RKO cells transduced with the ligand (RKO-CX3CL1) were not affected, nor more infiltrated upon transfer of CX3CR1-T lymphocytes, likely because high levels of the chemokine were shed by tumor cells in the systemic circulation, thus nullifying the blood-tissue chemokine gradient. CONCLUSIONS: This study demonstrates that ectopic expression of CX3CR1 enhanced the homing of adoptively transferred T cells towards CX3CL1-producing tumors, resulting in increased T cell infiltration in tumor tissues and decreased tumor growth. Our results also establish that a correct chemokine gradient between the systemic circulation and the tumor is an essential requirement in adoptive T-cell based immunotherapy to efficiently recruit T cell effectors at the correct sites

    Development and validation of a severity scale for leprosy Type 1 Reactions

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    Objectives: To develop a valid and reliable quantitative measure of leprosy Type 1 reactions.Methods: A scale was developed from previous scales which had not been validated. The face and content validity were assessed following consultation with recognised experts in the field. The construct validity was determined by applying the scale to patients in Bangladesh and Brazil who had been diagnosed with leprosy Type 1 reaction. An expert categorized each patient's reaction as mild or moderate or severe. Another worker applied the scale. This was done independently. In a subsequent stage of the study the agreement between two observers was assessed.Results: The scale had good internal consistency demonstrated by a Cronbach's alpha &gt;0.8. Removal of three items from the original scale resulted in better discrimination between disease severity categories. Cut off points for Type 1 reaction severities were determined using Receiver Operating Characteristic curves. A mild Type 1 reaction is characterized using the final scale by a score of 4 or less. A moderate reaction is a score of between 4.5 and 8.5. A severe reaction is a score of 9 or more.Conclusions: We have developed a valid and reliable tool for quantifying leprosy Type 1 reaction severity and believe this will be a useful tool in research of this condition, in observational and intervention studies, and in the comparison of clinical and laboratory parameters.<br/

    Pre-TCR Signaling and Inactivation of p53 Induces Crucial Cell Survival Pathways in Pre-T Cells

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    AbstractSignaling through the pre-TCR is essential for early T cell development and is severely impaired in mice lacking the CD3γ chain of the pre-TCR. We here address the molecular mechanisms underlying this defect. Impaired pre-TCR signaling is shown to be associated with a profound increase in the number of apoptotic CD4−CD8− (DN) thymocytes. Introduction of p53 deficiency into CD3γ-deficient mice completely reverses the cell survival defect in CD3γ-deficient DN thymocytes and rescues the block in pre-T cell differentiation. In addition, the CD4+CD8+ (DP) compartment is expanded to its normal size. These findings suggest that the pre-TCR regulates progression through the DNA-damage checkpoint of the DN to DP transition by inactivating p53

    Enhanced recruitment of genetically modified CX3CR1-positive human T cells into Fractalkine/CX3CL1 expressing tumors: Importance of the chemokine gradient

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    Background: Adoptive T-cell based immunotherapies constitute a promising approach to treat cancer, however, a major problem is to obtain effective and long-lasting anti-tumor responses. Lack of response may be due to insufficient trafficking of specific T cells to tumors. A key requirement for efficient migration of cytotoxic T cells is that they express chemokine receptors that match the chemokines produced by tumor or tumor-associated cells. Methods: In this study, we investigated whether the in vivo tumor trafficking of activated T cells could be enhanced by the expression of the chemokine receptor CX3CR1. Two human colorectal cancer cell lines were used to set up a xenograft tumor model in immunodeficient mice; the NCI-H630, constitutively expressing the chemokine ligand CX3CL1 (Fractalkine), and the RKO cell line, transduced to express CX3CL1. Results: Human primary T cells were transduced with the receptor CX3CR1-eGFP. Upon in vivo adoptive transfer of genetically modified CX3CR1-T cells in mice bearing NCI-H630 tumors, enhanced lymphocyte migration and tumor trafficking were observed, compared to mice receiving Mock-T cells, indicating improved homing ability towards ligand-expressing tumor cells. Furthermore, significant inhibition of tumor growth was found in mice receiving modified CX3CR1-T cells. In contrast, tumors formed by RKO cells transduced with the ligand (RKO-CX3CL1) were not affected, nor more infiltrated upon transfer of CX3CR1-T lymphocytes, likely because high levels of the chemokine were shed by tumor cells in the systemic circulation, thus nullifying the blood-tissue chemokine gradient. Conclusions: This study demonstrates that ectopic express

    Characterisation of the porous structure of Gilsocarbon graphite using pycnometry, cyclic porosimetry and void-network modeling

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    file: :C:/pdf/1-s2.0-S000862231400164X-main.pdf:pdfThe cores of the fourteen Advanced Gas-cooled nuclear Reactors (AGRs) within the UK comprise Gilsocarbon graphite, a manufactured material surrounded predominantly by CO2 at high pressure and temperature to provide heat exchange. The intense ionising radiation within the reactors causes radiolytic oxidation, and the resulting mass loss is a primary factor in determining reactor lifetime. The void structure of the porous Gilsocarbon graphite affects the permeability and diffusion of the carbon dioxide, and the sites of oxidation. To model this void structure, the porosities and densities of ten virgin Gilsocarbon graphite samples have been measured by powder and helium pycnometry. For comparison, results are also presented for highly ordered pyrolytic graphite (HOPG), and a fine-grained Ringsdorff graphite. Samples have been examined at a range of magnifications by electron microscopy. Total porosities and percolation characteristics have been measured by standard and cyclic mercury porosimetry up to an applied mercury pressure of 400MPa. Inverse modelling of the cyclic intrusion curves produces simulated void structures with characteristics which closely match those of experiment. Void size distributions of the structures are presented, together with much Supplementary Information. The simulated void networks provide the bases for future simulations of the radiolytic oxidation process itself

    T cells expressing a TCR-like antibody selected against the heteroclitic variant of a shared MAGE-A epitope do not recognise the cognate epitope

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    Antibodies-recognising peptides bound to the major histocompatibility complex (pMHC) represent potentially valuable and promising targets for chimeric antigen receptor (CAR) T cells to treat patients with cancer. Here, a human phage-Fab library has been selected using HLA-A2 complexed with a heteroclitic peptide variant from an epitope shared among multiple melanoma-associated antigens (MAGEs). DNA restriction analyses and phage ELISAs confirmed selection of unique antibody clones that specifically bind to HLA-A2 complexes or HLA-A2-positive target cells loaded with native or heteroclitic peptide. Antibodies selected against heteroclitic peptide, in contrast to native peptide, demonstrated significantly lower to even negligible binding towards native peptide or tumour cells that naturally expressed peptides. The binding to native peptide was not rescued by phage panning with antigen-positive tumour cells. Importantly, when antibodies directed against heteroclitic peptides were engineered into CARs and expressed by T cells, binding to native peptides and tumour cells was minimal to absent. In short, TCR-like antibodies, when isolated from a human Fab phage library using heteroclitic peptide, fail to recognise its native peptide. We therefore argue that peptide modifications to improve antibody selections should be performed with caution as resulting antibodies, either used directly or as CARs, may lose activity towards endogenously presented tumour epitopes
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