136 research outputs found

    Integrated Modelling for Understanding Watershed Development Impacts on Social and Biophysical Systems

    Get PDF
    The intention of watershed development (WD) programs in India is to improve the livelihoods of people and preserve the natural resource base, particularly in areas where water scarcity limits the development potential of rural communities. In practice, there are many complications to implementing WD programs in an effective and equitable way for all people within and between villages in a catchment. Our understanding of the potential implications of a program is often limited by the way in which we investigate the biophysical-social-economic system. Two common failings are (a) not properly considering the importance of the place, scope and scale of a problem and (b) using a disciplinary approach to make conclusions about the system as a whole. This paper discusses how we are addressing these issues as part of an integrated assessment project looking at WD in the state of Andhra Pradesh, India. The multi-disciplinary project team includes agronomists, economists, environmental modellers, groundwater and surface water hydrologists, and social scientists who together are aiming to develop a holistic understanding of the impacts of WD on biophysical, social and economic systems. Key to the project philosophy is the inclusion of government representatives, communities, and non-government organisations (NGOs) in developing the researchers\u27 understanding of the issues and complexities associated with WD and the critical questions that need addressing by the project. An integrated model is being developed that will incorporate crop production water use and hydrological (surface water and groundwater) models in addition to knowledge gained from extensive household surveys in villages in two case study catchments. The household surveys were developed based on discussions with NGOs working with the rural communities in Andhra Pradesh and are being used to examine economic and social outcomes (positive and negative) of WD for households. Measures of equity and resilience are being developed to measure differences in outcomes between villages (e.g. upstream, downstream) and within villages (e.g. income groups, gender, land ownership, etc)

    Antiproliferative activity and mode of action analysis of novel amino and amido substituted phenantrene and naphtho[2,1-b]thiophene derivatives

    Get PDF
    Herein we present and describe the design and synthesis of novel phenantrene derivatives substituted with either amino or amido side chains and their biological activity. Antiproliferative activities were assessed in vitro on a panel of human cancer cell lines. Tested compounds showed moderate activity against cancer cells in comparison with 5-fluorouracile. Among all tested compounds, some compounds substituted with cyano groups showed a pronounced and selective activity in the nanomolar range of inhibitory concentrations against HeLa and HepG2. The strongest selective activity against HeLa cells was observed for acrylonitriles 8 and 11 and their cyclic analogues 15 and 17 substituted with two cyano groups with a corresponding IC50 = 0.33, 0.21, 0.65 and 0.45 μM, respectively. Compounds 11 showed the most pronounced selectivity being almost non cytotoxic to normal fibroblasts. Additionally, mode of biological action analysis was performed in silico and in vitro by Western blot analysis of HIF-1-α relative expression for compounds 8 and 11

    An experimental and numerical investigation on the process efficiency of the focused TIG welding of Inconel 718 thick plates

    Get PDF
    A combined experimental and numerical approach was adopted to investigate the focused tungsten inert gas (TIG) welding process by producing bead-on-plate welds in Inconel 718 plates. Experimental investigations were carried out by means of thermocouple measurements and optical macrographs of the weld cross-section. Three dimensional finite element (FE) simulations were conducted using the commercial specialized FE software Sysweld in order to predict the thermal field induced by the process in the plates. The work presents an approach to investigate the process efficiency and calibrate the heat source model in order to produce a full thermal characterization the plasmatron welding apparatus

    Are Metastases from Metastases Clinical Relevant? Computer Modelling of Cancer Spread in a Case of Hepatocellular Carcinoma

    Get PDF
    Background: Metastasis formation remains an enigmatic process and one of the main questions recently asked is whether metastases are able to generate further metastases. Different models have been proposed to answer this question; however, their clinical significance remains unclear. Therefore a computer model was developed that permits comparison of the different models quantitatively with clinical data and that additionally predicts the outcome of treatment interventions. Methods: The computer model is based on discrete events simulation approach. On the basis of a case from an untreated patient with hepatocellular carcinoma and its multiple metastases in the liver, it was evaluated whether metastases are able to metastasise and in particular if late disseminated tumour cells are still capable to form metastases. Additionally, the resection of the primary tumour was simulated. The simulation results were compared with clinical data. Results: The simulation results reveal that the number of metastases varies significantly between scenarios where metastases metastasise and scenarios where they do not. In contrast, the total tumour mass is nearly unaffected by the two different modes of metastasis formation. Furthermore, the results provide evidence that metastasis formation is an early event and that late disseminated tumour cells are still capable of forming metastases. Simulations also allow estimating how the resection of the primary tumour delays the patient’s death. Conclusion: The simulation results indicate that for this particular case of a hepatocellular carcinoma late metastases, i.e.

    Subdominant/Cryptic CD8 T Cell Epitopes Contribute to Resistance against Experimental Infection with a Human Protozoan Parasite

    Get PDF
    During adaptive immune response, pathogen-specific CD8+ T cells recognize preferentially a small number of epitopes, a phenomenon known as immunodominance. Its biological implications during natural or vaccine-induced immune responses are still unclear. Earlier, we have shown that during experimental infection, the human intracellular pathogen Trypanosoma cruzi restricts the repertoire of CD8+ T cells generating strong immunodominance. We hypothesized that this phenomenon could be a mechanism used by the parasite to reduce the breath and magnitude of the immune response, favoring parasitism, and thus that artificially broadening the T cell repertoire could favor the host. Here, we confirmed our previous observation by showing that CD8+ T cells of H-2a infected mice recognized a single epitope of an immunodominant antigen of the trans-sialidase super-family. In sharp contrast, CD8+ T cells from mice immunized with recombinant genetic vaccines (plasmid DNA and adenovirus) expressing this same T. cruzi antigen recognized, in addition to the immunodominant epitope, two other subdominant epitopes. This unexpected observation allowed us to test the protective role of the immune response to subdominant epitopes. This was accomplished by genetic vaccination of mice with mutated genes that did not express a functional immunodominant epitope. We found that these mice developed immune responses directed solely to the subdominant/cryptic CD8 T cell epitopes and a significant degree of protective immunity against infection mediated by CD8+ T cells. We concluded that artificially broadening the T cell repertoire contributes to host resistance against infection, a finding that has implications for the host-parasite relationship and vaccine development

    The role of ascorbate in antioxidant protection of biomembranes: Interaction with vitamin E and coenzyme Q

    Full text link
    One of the vital roles of ascorbic acid (vitamin C) is to act as an antioxidant to protect cellular components from free radical damage. Ascorbic acid has been shown to scavenge free radicals directly in the aqueous phases of cells and the circulatory system. Ascorbic acid has also been proven to protect membrane and other hydrophobic compartments from such damage by regenerating the antioxidant form of vitamin E. In addition, reduced coenzyme Q, also a resident of hydrophobic compartments, interacts with vitamin E to regenerate its antioxidant form. The mechanism of vitamin C antioxidant function, the myriad of pathologies resulting from its clinical deficiency, and the many health benefits it provides, are reviewed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44796/1/10863_2004_Article_BF00762775.pd
    • …
    corecore