Methodologies Utilizing Protected Oxyallyl Cations for Molecular Design

This master’s thesis discusses developments of novel organic methodologies utilizing oxyallyl cationic systems in the pursuit of highly functionalized molecular scaffolds. Chapter 1 focuses on the discovery of the oxyallyl cation intermediate, and examines reported transformations. Detailed optimization and substrate studies following exploitation of a protected 2-oxyallyl cation for nucleophilc capture comprises the information in both Chapter 2 and Chapter 3. Chapter 4 extends methodologies performed by my colleagues and establishes a tandem process using 2-silyloxypentadienyl cations to furnish complex structures. In this report, reaction design and optimization are chronicled, followed by exploration into the reactivity, mechanism, and scope of the developed reactions

Risky Shift Versus Cautious Shift: Determining Differences In Risk Taking Between Private And Public Management Decision-Making

This paper uses empirical evidence to examine whether people take more risk for their own potential loss/gain and less risk for other people’s potential loss/gain or vice versa.  An experiment is described wherein participants had the option of taking different risks in exchange for their own benefit and the benefit of others.  Results indicate that subjects take a statistically significant higher level of risk for themselves as individuals than they do when other’s payoffs are at stake.  This indicates that people are less risk averse in making decisions for themselves and more risk averse in making decisions that affect others.  However, when the amount of reward is increased, the findings change.  The purpose of the experiment is to find a better explanation for how government-owned businesses or large corporations work, where anecdotal evidence suggests much less innovation and risk taking takes place compared to small proprietary firms.&nbsp

Intellectual Capital and Public University Libraries : a Knowledge Sharing Perspective

Knowledge economy is resulting in competition which increases the demand for innovation. The wave has urged libraries which faced no competition before to think of ways to add and show more value to their users and donors. The coming of digital libraries and other information providers challenges traditional libraries to improve their practices before doomed obsolete. This research focuses on establishing the relationships between intellectual capital and knowledge sharing. Given the binary nature of the relationship between the former and the latter, this research emphasizes how intellectual capital can improve knowledge sharing in a value making process. Through triangulating research methods, the research addresses the issue of intangible assets as unseen value in public university libraries. Believing that a well laid infrastructure for knowledge sharing coupled with motivated staff will eventually enable libraries to know what they knows and gain more competitive advantage. Using an explanatory survey, the research administered a questionnaire to establish how knowledge is shared among staff of Tanzania public university libraries. From a postpostivistic point of view the research found out how knowledge is shared and what kind of incentives are in place and used the findings to suggest better infrastructure and staff motivation schemes. Due to time and distance constraints the research focused only on the aspect of human capital and structural capital to suggest how they can help libraries to uplift knowledge sharing. Other aspects of intellectual capital such as customer capital, renewal capital and process capital are left to be covered by other researchers.Joint Master Degree in Digital Library Learning (DILL

Prediction of Impact Strength of TIG Welded Cr-Mo Steel Using Artificial Neural Networks

Welding is a critical and energy-intensive process with significant importance in the manufacturing industry, enabling the creation of joints capable of withstanding diverse loads without failure. Accurate prediction of welding parameters' effects on the thermal cycle and strength of metals during and after welding is essential to ensure the reliability of welds. This study investigates the influence of welding parameters such as welding current, material thickness, number of weld passes, and electrode diameter on the impact strength of Cr-Mo steel bars. Pure tungsten with 2% thoriated Tungsten Inert Gas (TIG) electrodes was used to join the metal sheets autogenously. Artificial neural network (ANN) was used in creating the model that predicts the impact strength of the steel. Sample with welding parameters of 15 mm thickness, 90 A current, 3 weld passes, and Ø2.4 mm electrode size exhibited the highest impact strength. Furthermore, the analysis of variance (ANOVA) results show that the material thickness and number of weld passes contribute significantly to the impact strength of the steel. The ANN model trained by the Levenberg-Marquardt algorithm had an average training dataset root mean square error (RSME) of 4.12%. This study contributes to the reliability and performance of welded joints in various applications

Genomic sequencing of SARS-CoV-2 in Rwanda reveals the importance of incoming travelers on lineage diversity

COVID-19 transmission rates are often linked to locally circulating strains of SARS-CoV-2. Here we describe 203 SARS-CoV-2 whole genome sequences analyzed from strains circulating in Rwanda from May 2020 to February 2021. In particular, we report a shift in variant distribution towards the emerging sub-lineage A.23.1 that is currently dominating. Furthermore, we report the detection of the first Rwandan cases of the B.1.1.7 and B.1.351 variants of concern among incoming travelers tested at Kigali International Airport. To assess the importance of viral introductions from neighboring countries and local transmission, we exploit available individual travel history metadata to inform spatio-temporal phylogeographic inference, enabling us to take into account infections from unsampled locations. We uncover an important role of neighboring countries in seeding introductions into Rwanda, including those from which no genomic sequences were available. Our results highlight the importance of systematic genomic surveillance and regional collaborations for a durable response towards combating COVID-19.info:eu-repo/semantics/publishe

Host choice and multiple blood feeding behaviour of malaria vectors and other anophelines in Mwea rice scheme, Kenya

<p>Abstract</p> <p>Background</p> <p>Studies were conducted between April 2004 and February 2006 to determine the blood-feeding pattern of <it>Anopheles </it>mosquitoes in Mwea Kenya.</p> <p>Methods</p> <p>Samples were collected indoors by pyrethrum spay catch and outdoors by Centers for Disease Control light traps and processed for blood meal analysis by an Enzyme-linked Immunosorbent Assay.</p> <p>Results</p> <p>A total of 3,333 blood-fed <it>Anopheles </it>mosquitoes representing four <it>Anopheles </it>species were collected and 2,796 of the samples were assayed, with <it>Anopheles arabiensis </it>comprising 76.2% (n = 2,542) followed in decreasing order by <it>Anopheles coustani </it>8.9% (n = 297), <it>Anopheles pharoensis </it>8.2% (n = 272) and <it>Anopheles funestus </it>6.7% (n = 222). All mosquito species had a high preference for bovine (range 56.3–71.4%) over human (range 1.1–23.9%) or goat (0.1–2.2%) blood meals. Some individuals from all the four species were found to contain mixed blood meals. The bovine blood index (BBI) for <it>An. arabiensis </it>was significantly higher for populations collected indoors (71.8%), than populations collected outdoors (41.3%), but the human blood index (HBI) did not differ significantly between the two populations. In contrast, BBI for indoor collected <it>An. funestus </it>(51.4%) was significantly lower than for outdoor collected populations (78.0%) and the HBI was significantly higher indoors (28.7%) than outdoors (2.4%). Anthropophily of <it>An. funestus </it>was lowest within the rice scheme, moderate in unplanned rice agro-ecosystem, and highest within the non-irrigated agro-ecosystem. Anthropophily of <it>An. arabiensis </it>was significantly higher in the non-irrigated agro-ecosystem than in the other agro-ecosystems.</p> <p>Conclusion</p> <p>These findings suggest that rice cultivation has an effect on host choice by <it>Anopheles </it>mosquitoes. The study further indicate that zooprophylaxis may be a potential strategy for malaria control, but there is need to assess how domestic animals may influence arboviruses epidemiology before adapting the strategy.</p

Liver Transplantation

Liver transplantation has become a lifesaving procedure for patients who have chronic end-stage liver disease and acute liver failure. The satisfactory outcome of liver transplantation has led to insufficient supplies of deceased donor organs, particularly in East Asia. Hence, East Asian surgeons are concentrating on developing and performing living-donor liver transplantation (LDLT). This review article describes an update on the present status of liver transplantation, mainly in adults, and highlights some recent developments on indications for transplantation, patient selection, donor and recipient operation between LDLT and deceased-donor liver transplantation (DDLT), immunosuppression, and long-term management of liver transplant recipients. Currently, the same indication criteria that exist for DDLT are applied to LDLT, with technical refinements for LDLT. In highly experienced centers, LDLT for high-scoring (>30 points) Model of End-Stage Liver Disease (MELD) patients and acute-on-chronic liver-failure patients yields comparably good outcomes to DDLT, because timely liver transplantation with good-quality grafting is possible. With increasing numbers of liver transplantations and long-term survivors, specialized attention should be paid to complications that develop in the long term, such as chronic renal failure, hypertension, diabetes mellitus, dyslipidemia, obesity, bone or neurological complications, and development of de novo tumors, which are highly related to the immunosuppressive treatment