Risk averse operation of an electricity plant in an electricity market

New methods are required to make optimal operation decisions for electricity generating and consuming plants in market-based electricity industries. Since wholesale electricity is traded on a spot price basis, both generators and consumers face uncertainty in their future income. Operating plants with inter-temporal links are particularly difficult since operation decisions at one instant affect the available operation decisions after that, and hence affect future income. Operation decision making with a risk-averse attitude is a method to handle uncertainty, however, some form of financial instruments, such as forward contracts, are required to allocate risk. Since electricity markets operate on a discrete time basis, a multi-stage decision making method is required to operate an electricity plant with inter-temporal links. Although risk-averse decision making has been used in other contexts, few attempts have been made to use these techniques for multi-stage problems. In this thesis, a new multi-stage risk-averse decision making algorithm is proposed and applied to make operation and forward contract trading decisions for a plant in an electricity market. In the proposed algorithm, risk aversion is incorporated in sequential decision making using the expected utility method with a von Neumann-Morgenstern utility function. Decisions are taken to maximise the utility of total financial income. Since utility functions have a concave shape, the marginal utility of income diminishes with increased income, giving risk aversion. A solution structure similar to dynamic programming is proposed for the risk management algorithm by introducing a state variable to represent past behaviour. The proposed algorithm is applied to make decisions for electricity plant and market models. Simulation results for different plant models show a clear reduction in financial risk when compared with risk-neutral operation. Any reduction in risk is shown to be sensitive to the decision maker s attitude toward risk used in the algorithm. Simulation results suggest that forward contracts play a major role in minimising risk when starting plants with high start up costs. Forward contracts ensure financial security even under unfavourable market conditions. It is shown that, plants employing a risk-averse attitude which do not commit to start, do so after securing their future financial position using forward contracts. In general, the proposed risk management algorithm shows potential for use in electricity markets

IMPORTANCE OF IMPROVING BIOLOGICAL ACTIVITY OF TEA SOILS IN SOUTHERN PROVINCE OF SRI LANKA.

The detrimental effects of soil pesticides on soil micro biota and biodiversity of the teaecosystem are poorly understood. In the current study, microbial activity in southern teasoils of Sri Lanka as affected by application of commonly used soil pesticides and certaincultural practices was evaluated by m-:asuring the soil respiration in vitro and in vivo.CO2 evolution rates in Southern tea soils were generally low as compared to soils in otherareas. Herbicide and formalin applications significantly (p=O.005) suppressed thebiological activity of Southern tea soils; the nematicide tested was less effective.Incorporation of compost and tea waste significantly (p=O.005) elevated CO2 evolution ratein tea soils than that of in undisturbed, virgin forest soils. Forking strengthened microbialbiomass through improved soil physical conditions. Soil biomass was positively correlatedwith growth of the test plants viz tea and tomatoSouthern tea soils with low organic matter contents arc exposed to repeated application ofherbicides and negligence of important agronomic practices due to labour shortage. Suchmalpractices could aggravate potential build up of pesticide residues in the soil. Thus,improvement of soil organic matter status by incorporation of various organic amendments,establishment of green manure crops, rehabilitation of old tea soils and more importantly,restricted usage of agro-chemicals etc. is essential. These practices will assure long-termsustainable productivity and quality of soils as well as help degrade accumulated chemicalresidues and elevate densities of soil microbial communities. As a consequence, increasedefficacy of bio control of nematodes and soil borne pathogens and proper administration ofnatural nutrient cycles could be envisaged.

Human blood autoantibodies in the detection of colorectal cancer

Colorectal cancer (CRC) is the second most common malignancy in the western world. Early detection and diagnosis of all cancer types is vital to improved prognosis by enabling early treatment when tumours should be both resectable and curable. Sera from 3 different cohorts; 42 sera (21 CRC and 21 matched controls) from New York, USA, 200 sera from Pittsburgh, USA (100 CRC and 100 controls) and 20 sera from Dundee, UK (10 CRC and 10 controls) were tested against a panel of multiple tumour-associated antigens (TAAs) using an optimised multiplex microarray system. TAA specific IgG responses were interpo- lated against the internal IgG standard curve for each sample. Individual TAA specific responses were examined in each cohort to determine cutoffs for a robust initial scoring method to establish sensitivity and specificity. Sensitivity and specificity of combinations of TAAs provided good discrimination between cancer-positive and normal serum. The overall sensitivity and specificity of the sample sets tested against a panel of 32 TAAs were 61.1% and 80.9% respectively for 6 antigens; p53, AFP, K RAS, Annexin, RAF1 and NY-CO16. Furthermore, the observed sensitivity in Pittsburgh sample set in different clinical stages of CRC;stageI(n=19),stageII(n=40),stageIII(n=34)andstageIV(n=6)wassimilar (73.6%, 75.0%, 73.5% and 83.3%, respectively), with similar levels of sensitivity for right and left sided CRC. We identified an antigen panel of sufficient sensitivity and specificity for early detection of CRC, based upon serum profiling of autoantibody response using a robust multiplex antigen microarray technology. This opens the possibility of a blood test for screening and detection of early colorectal cancer. However this panel will require further validation studies before they can be proposed for clinical practice

Immunoregulatory Mechanisms Underlying Prevention of Colitis-Associated Colorectal Cancer by Probiotic Bacteria

Background: Inflammatory bowel disease (IBD) increases the risk of colorectal cancer. Probiotic bacteria produce immunoregulatory metabolites in vitro such as conjugated linoleic acid (CLA), a polyunsaturated fatty acid with potent anticarcinogenic effects. This study aimed to investigate the cellular and molecular mechanisms underlying the efficacy of probiotic bacteria in mouse models of cancer. Methodology/Principal Findings: The immune modulatory mechanisms of VSL#3 probiotic bacteria and CLA were investigated in mouse models of inflammation-driven colorectal cancer. Colonic specimens were collected for histopathology, gene expression and flow cytometry analyses. Immune cell subsets in the mesenteric lymph nodes (MLN), spleen and colonic lamina propria lymphocytes (LPL) were phenotypically and functionally characterized. Mice treated with CLA or VSL#3 recovered faster from the acute inflammatory phase of disease and had lower disease severity in the chronic, tumor-bearing phase of disease. Adenoma and adenocarcinoma formation was also diminished by both treatments. VSL#3 increased the mRNA expression of TNF-a, angiostatin and PPAR c whereas CLA decreased COX-2 levels. Moreover, VSL#3-treated mice had increased IL-17 expression in MLN CD4+ T cells and accumulation of Treg LPL and memory CD4+ T cells. Conclusions/Significance: Both CLA and VSL#3 suppressed colon carcinogenesis, although VSL#3 showed greater anticarcinogeni

Plasma MMP-2 and MMP-7 levels are elevated first month after surgery and may promote growth of residual metastases.

BACKGROUND: MMP-2 also known as gelatinase A and MMP-7 (matrilysin) are members of the zinc-dependent family of MMPs (Matrix metalloproteinase). MMP-2 and MMP-7 are remodeling enzymes that digest extracellular matrix; MMP-2 is extensively expressed during development and is upregulated at sites of tissue damage, inflammation, and in stromal cells of metastatic tumors. MMP-7 is expressed in the epithelial cells and in a variety of cancers including colon tumors. Plasma MMP-2 and MMP-7 levels were assessed before and after minimally invasive colorectal resection for cancer pathology. AIM: To determine plasma MMP-2 and MMP-7 levels before and after minimally invasive colorectal resection for cancer pathology. METHODS: Patients enrolled in a plasma bank for whom plasma was available were eligible. Plasma obtained from preoperative (Preop) and postoperative blood samples was used. Only colorectal cancer (CRC) patients who underwent elective minimally invasive cancer resection with preop, post-operative day (POD) 1, 3 and at least 1 late postop sample (POD 7-34) were included. Late samples were bundled into 7 d blocks (POD 7-13, 14-20, RESULTS: Total 88 minimally invasive CRC resection CRC patients were studied (right colectomy, 37%; sigmoid, 24%; and LAR/AR 18%). Cancer stages were: 1, 31%; 2, 30%; 3, 34%; and 4, 5%. Mean Preop MMP-2 plasma level (ng/mL) was 179.3 ± 40.9 ( CONCLUSION: MMP-2 levels are elevated for 5 wk and MMP-7 levels elevated for weeks 2-6. The etiology of these changes in unclear, trauma and wound healing likely play a role. These changes may promote residual tumor growth and metastasis

The wine and beer yeast Dekkera bruxellensis.

Recently, the non-conventional yeast Dekkera bruxellensis has been gaining more and more attention in the food industry and academic research. This yeast species is a distant relative of Saccharomyces cerevisiae, and especially known for two important characteristics: on one hand it is considered to be one of the main spoilage organisms in the wine and bioethanol industry, on the other hand it is "indispensable" as a contributor to the flavour profile of Belgium lambic and gueuze beers. Additionally, it adds to the characteristic aromatic properties of some red wines. Recently this yeast has also become a model to study yeast evolution. In this review we focus on the recently developed molecular and genetic tools, such as complete genome sequencing and transformation, to study and manipulate this yeast. We also focus on the areas which are particularly well explored in this yeast, such as the synthesis of off-flavours, yeast detection methods, carbon metabolism and evolutionary history. This article is protected by copyright. All rights reserved