Computable General Equilibrium Modeling for Regional Analysis

Partial equilibrium analysis illustrates results for one market at a time. However, there often exist market interactions and thus market feedbacks. Pricing outcomes in one market usually have effects in other markets, and these effects, in turn, create ripples throughout the economy, perhaps even to the extent of affecting the price-quantity equilibrium in the original market. To represent this complex set of economic relationships, it is necessary to go beyond partial equilibrium analysis and construct a model that permits viewing many markets simultaneously. This Web Book provides an introduction to and overview of the general equilibrium modeling framework in the context of regional analysis.https://researchrepository.wvu.edu/rri-web-book/1023/thumbnail.jp

Improved seed variety value chains in Zambia: A missed opportunity to improve smallholder productivity

Sorghum and millet are very important sources of food and farm income for smallholder farmers, which can be enhanced especially if linked to new markets. Though viewed as minor traditional crops in Zambia, sorghum and millet remain important food crops for semi-arid areas of the country. Production and productivity of these crops is low and has been stagnant for over 20 years. In recent years, there have been new market developments creating incentives for farmers to increase productivity. This study uses a value chain framework to examine the challenges and opportunities for sorghum, millet, and maize in Zambia. Information from 130 smallholder farmers, 57 seed dealers, five private seed companies, and two research institutions was collected in Lusaka and Siavonga districts in 2008. Results showed that despite new market opportunities farmers were slow to adopt new technology. Development and release of improved varieties was very slow due to policy and institutional constraints. Also, significant productivity enhancements were impeded by poor access to high-yielding seed varieties, fertilizer, and by government policies and institutions. The value chains for these crops did not promote productivity gains due to low volumes traded, inadequate access to support services of extension, finance and roads as well as policies that subsidize maize to the exclusion of sorghum and millet. These constraints need to be addressed throughout the value chain to ensure productivity gains

Feasibility and Environmental Sustainability of a 103.5 kWp floating Photovoltaic Electrical System with a Case Study in a Hydroelectric Power Plant, Santa Clara Hpp, Located in the South of Brazil Region

Typical environmental problems associated with the implementation of solar photovoltaic systems for the generation of peak electrical energy, on a larger scale, such as on the order of 1 MWp, is in the occupied area, usually more than 3 km2. This can be minimized by the use of water parks or water dam’s reservoir, small and large hydroelectric power plants dams. Both the terrestrial and aquatic systems can impact the site, the first one, for the need to promote earthworks, removal of extensive green areas in the surroundings, installation of new transmission line, among others; and the second, despite the fact that a flat surface is already used and that there is no need for new civil procedures for its installation and can normally take advantage of the existing power transmission line, may cause changes in the biota of the reservoir, depending on the shading areas on the surface of the lake. Due to these facts, this research was proposed to investigate, parameterize and tropicalize an electric power generation system based on floating silicon photovoltaic cell panels installed in the Santa Clara HPP reservoir, in terms of peak power, durability, aspects and environmental impacts, with the study of possible evolutionary improvements of the project such as "tracking" or solar tracking, as well as dynamism of the structure, allowing the shadow area to be shifted over time, minimizing its effects in the local biota

Intraductal fully covered self-expanding metal stents in the management of post-liver transplant anastomotic strictures: a UK wide experience.

Background: Fully covered intraductal self-expanding metal stents (IDSEMS) have been well described in the management of post-liver transplant (LT) anastomotic strictures (ASs). Their antimigration waists and intraductal nature make them suited for deployment across the biliary anastomosis. Objectives: We conducted a multicentre study to analyse their use and efficacy in the management of AS. Design: This was a retrospective, multicentre observational study across nine tertiary centres in the United Kingdom. Methods: Consecutive patients who underwent endoscopic retrograde cholangiopancreatography with IDSEMS insertion were analysed retrospectively. Recorded variables included patient demographics, procedural characteristics, response to therapy and follow-up data. Results: In all, 162 patients (100 males, 62%) underwent 176 episodes of IDSEMS insertion for AS. Aetiology of liver disease in this cohort included hepatocellular carcinoma (n = 35, 22%), followed by alcohol-related liver disease (n = 29, 18%), non-alcoholic steatohepatitis (n = 20, 12%), primary biliary cholangitis (n = 15, 9%), acute liver failure (n = 13, 8%), viral hepatitis (n = 13, 8%) and autoimmune hepatitis (n = 12, 7%). Early AS occurred in 25 (15%) cases, delayed in 32 (20%) cases and late in 95 (59%) cases. Age at transplant was 54 years (range, 12-74), and stent duration was 15 weeks (range, 3 days-78 weeks). In total, 131 (81%) had complete resolution of stricture at endoscopic re-evaluation. Stricture recurrence was observed in 13 (10%) cases, with a median of 19 weeks (range, 4-88 weeks) after stent removal. At removal, there were 21 (12%) adverse events, 5 (3%) episodes of cholangitis and 2 (1%) of pancreatitis. In 11 (6%) cases, the removal wires unravelled, and 3 (2%) stents migrated. All were removed endoscopically. Conclusion: IDSEMS appears to be safe and highly efficacious in the management of post-LT AS, with low rates of AS recurrence

Factors Associated With Outcomes of Patients With Primary Sclerosing Cholangitis and Development and Validation of a Risk Scoring System.

We sought to identify factors that are predictive of liver transplantation or death in patients with primary sclerosing cholangitis (PSC), and to develop and validate a contemporaneous risk score for use in a real-world clinical setting. Analyzing data from 1,001 patients recruited to the UK-PSC research cohort, we evaluated clinical variables for their association with 2-year and 10-year outcome through Cox-proportional hazards and C-statistic analyses. We generated risk scores for short-term and long-term outcome prediction, validating their use in two independent cohorts totaling 451 patients. Thirty-six percent of the derivation cohort were transplanted or died over a cumulative follow-up of 7,904 years. Serum alkaline phosphatase of at least 2.4 × upper limit of normal at 1 year after diagnosis was predictive of 10-year outcome (hazard ratio [HR] = 3.05; C = 0.63; median transplant-free survival 63 versus 108 months; P < 0.0001), as was the presence of extrahepatic biliary disease (HR = 1.45; P = 0.01). We developed two risk scoring systems based on age, values of bilirubin, alkaline phosphatase, albumin, platelets, presence of extrahepatic biliary disease, and variceal hemorrhage, which predicted 2-year and 10-year outcomes with good discrimination (C statistic = 0.81 and 0.80, respectively). Both UK-PSC risk scores were well-validated in our external cohort and outperformed the Mayo Clinic and aspartate aminotransferase-to-platelet ratio index (APRI) scores (C statistic = 0.75 and 0.63, respectively). Although heterozygosity for the previously validated human leukocyte antigen (HLA)-DR*03:01 risk allele predicted increased risk of adverse outcome (HR = 1.33; P = 0.001), its addition did not improve the predictive accuracy of the UK-PSC risk scores. Conclusion: Our analyses, based on a detailed clinical evaluation of a large representative cohort of participants with PSC, furthers our understanding of clinical risk markers and reports the development and validation of a real-world scoring system to identify those patients most likely to die or require liver transplantation.Financial support has been received by National Institute of Health Research (RD-TRC and Birmingham Biomedical Research Centre), Isaac Newton Trust, Addenbrooke’s charitable trust, Norwegian PSC Research Center and PSC Support. GMH is supported by the Lily and Terry Horner Chair in Autoimmune Liver Disease Research, Toronto Centre for Liver Disease, Toronto

Reconstruction of the mouse extrahepatic biliary tree using primary human extrahepatic cholangiocyte organoids

Treatment of common bile duct disorders such as biliary atresia or ischaemic strictures is limited to liver transplantation or hepatojejunostomy due to the lack of suitable tissue for surgical reconstruction. Here, we report a novel method for the isolation and propagation of human cholangiocytes from the extrahepatic biliary tree and we explore the potential of bioengineered biliary tissue consisting of these extrahepatic cholangiocyte organoids (ECOs) and biodegradable scaffolds for transplantation and biliary reconstruction in vivo. ECOs closely correlate with primary cholangiocytes in terms of transcriptomic profile and functional properties (ALP, GGT). Following transplantation in immunocompromised mice ECOs self-organize into tubular structures expressing biliary markers (CK7). When seeded on biodegradable scaffolds, ECOs form tissue-like structures retaining biliary marker expression (CK7) and function (ALP, GGT). This bioengineered tissue can reconstruct the wall of the biliary tree (gallbladder) and rescue and extrahepatic biliary injury mouse model following transplantation. Furthermore, it can be fashioned into bioengineered ducts and replace the native common bile duct of immunocompromised mice, with no evidence of cholestasis or lumen occlusion up to one month after reconstruction. In conclusion, ECOs can successfully reconstruct the biliary tree following transplantation, providing proof-of-principle for organ regeneration using human primary cells expanded in vitro

Impact of direct‐acting antiviral agents on liver function in patients with chronic hepatitis C virus infection

© 2020 The Authors. Journal of Viral Hepatitis published by John Wiley & Sons Ltd Whilst the benefit of direct-acting antiviral agents (DAAs) in achieving sustained virological response (SVR) is now well-accepted, their impact on liver function, particularly in relation to achievement of SVR, has not been well documented. We studied 2394 patients with chronic HCV infection, 1276 receiving DAAs and 1118 interferon-based therapy. Liver function was assessed by the albumin-bilirubin (ALBI) score or grade. Overall survival according to SVR status and baseline ALBI grade was examined. We also studied time to first decompensation according to ALBI grade, as well as longitudinal changes in ALBI score over time according to SVR. Among the patients receiving DAAs, 89% achieved SVR (Japan=99%, UK=78%). Amongst the decompensated patients in the UK cohort, three distinct risk groups according to ALBI grade at baseline were observed. The UK patients receiving DAAs, who had predominantly decompensated disease, showed clear evidence of improvement of liver function detectable within 2years of the start of treatment, especially in those achieving SVR. These early changes in liver function were very similar to those observed in the first 2-3years after interferon-based therapy. DAAs improve liver function especially in those with decompensated disease who achieve SVR. Experience with interferon-based therapy suggests that failure to achieve SVR is associated with long-term decline in liver function and, in contrast, patients who do achieve SVR can expect long-term disease improvement and subsequent stabilization of liver function. Our initial analysis suggests that those receiving DAAs are likely, in the long term, to follow a similar course