Listings from the Emerging Economies: An Opportunity for Reputable Stock Exchanges

We provide current evidence to show that the numbers of sponsored depositary receipts created and cross‐listed have increased by more than two‐fold over the last decade and a substantial proportion of this growth came from the emerging and developing economies. We argue that the needs of this clientele and the inadequacies of existing legal and financial system create an opportunity for reputable stock exchanges to play the role of an information and reputation intermediary and in so doing allow exchanges to leverage on their reputation capital to compete more effectively for the growing business from the emerging and developing economies. We contribute further by developing a parsimonious model to analyze the interaction between an exchange playing the new role and firms seeking to list their equity on the exchange. We show that a subgame perfect equilibrium is obtained and provide an explanation for the spike in delisting in the latter half of 2007. Our model fills an important gap by addressing some shortcomings in existing theoretical models

What Financial Risk Managers Can Learn from Six Sigma Quality Programs

As the financial crisis of 2008 has revealed, there are some flaws in the models used by financial firms to assess risk. Credit, volatility, and liquidity risk were all inadequately modeled by supposedly sophisticated financial institutions employing dozens of financial engineers with advanced degrees. It is now clear that some of the underlying assumptions of the statistical models utilized were seriously flawed, and interactive and systemic effects were improperly modeled. Correcting these modeling flaws is one approach to preventing a reoccurrence. However, another approach is suggested by Six Sigma quality programs used in manufacturing and service industries. Some basic tenets of the Six Sigma programs are directly applicable to improving risk management in financial firms and in portfolio design. These include the features of over-engineering, robust design, and reliability engineerin

Black Swans and Retirement Strategies: Is “Buy and Hold Best”?

The recent market crash which has led to as much as a 47% drop in the value of the S&P500 index has made some of us wonder if there is a cost effective way for us to hedge our retirement portfolios against such a drastic loss. Our objective is to investigate empirically the tradeoffs that will arise from using a protective put strategy for hedging retirement portfolios over an investment horizon that is long enough to be comparable to the average holding period for retirement portfolio

Anaerobic Digestion: Awareness, Implementation, and Simulation

Anaerobic digestion (AD) is the process in which organic matter is fermented in an oxygen-deprived environment to produce renewable biogas. Our project is multi-faceted, with the overall goal of raising public awareness of AD as a transitional energy source. To that end, our group has named itself Undergraduates Raising Awareness for Anaerobic Digestion (URAAD). We are approaching this goal on three fronts, including (i) a website, (ii) a physical lab-scale digester, and (iii) a computer simulation of anaerobic digestion. The first component, the website, was developed with the aim of serving as a resource for the public. It includes educational resources written in a “digestible” manner, explaining how AD works and its potential benefits. The website also includes a user-friendly economic calculator, which can be used to conduct rough estimates of AD’s economic feasibility. The main factor holding back the growth of AD has traditionally been its low economic potential, but with newer technology and government incentives, we believe AD is economically viable under specific contexts, and our work aims to make clear what those conditions are. The website also hosts info about our group and a timeline of our accomplishments. It is currently hosted publicly at the link: https://umassuraad.github.io/ and has been optimized for both desktop and mobile use. The website is currently featured on the UMass Integrated Concentration of Science (iCons) page and we are making ongoing efforts to increase its searchability/impact. The second component is a lab-scale biodigester meant to be an educational demo/experiment for students on campus. Participants will be able to insert a batch of compost and then observe the anaerobic digestion process in action, while also collecting the biogas at the end for further analysis. The biodigester equipment was funded through the UMass Sustainability, Innovation, and Engagement Fund (SEIF) grant that was won in April 2020. Since then, it has been under construction in a Chemical Engineering lab on Campus property and is sourcing the organic feedstock from UMass’s Office of Waste Management’s compost inventory. The third component is a computer simulation of AD being conducted as an undergraduate thesis by team member Kieran Tay. It is being conducted using Chemical Engineering department supplied software so that our group can incorporate feedstock, product, and reactor engineering elements into a robust simulation so that we can then implement those models in the AD calculator. Literature review was conducted through the use of the UMass Library’s online resources for both the simulations and the website resources. This project is ongoing (having been originally founded in the winter of 2019) and we aim it to be passed down from year to year, continuously growing in scope and impact

The Development of Selective Aromatic Functionalizations in Acridinium-mediated Photoredox Catalysis

Aromatic rings are important molecular components of many pharmaceuticals, agrochemicals, organic materials and natural products, and the development of selective arene functionalization transformations has been broadly applied in basic and translational research. Photoredox catalysis is an invaluable synthetic tool for the activation of organic molecules via single electron redox pathways. This synthetic strategy enables the construction of carbon-carbon and carbon-heteroatom bonds with orthogonal reactivity to classical two-electron pathways. An introduction to both topics is provided in the first two chapters. The Nicewicz lab has recently developed a variety of transformations that proceed by reactive cation radical species. These systems rely on the ability of an acridinium photoredox catalyst to promote single electron oxidation of a target organic substrate by photoinduced electron transfer. Noting the importance of aromatic molecules, we sought to develop photoredox-catalyzed chemo- and site- selective arene functionalizations that proceed through arene radical cations. As a result, two general reaction methodologies emerged from our investigations into the reactivity of arene radical cations: selective aromatic carbon-hydrogen (C–H) bond and carbon-oxygen (C–O) bond functionalizations. These photoredox-catalyzed aryl C–H amination and C–H (radio)fluorination reactions feature the use of a nitroxyl radical co-catalyst and oxygen to achieve a net oxidative transformation, which furnishes aryl amines and radiolabeled fluoroarenes with high site- selectivity. A diverse range of arenes were compatible with both transformations and the application of 18F-labeled aromatics to positron emission tomography (PET) imaging was demonstrated. These two projects are covered in Chapters 3 and 5. Photoredox-catalyzed aryl C–O functionalizations occur by a complementary strategy to nucleophilic aromatic substitution (SNAr). The generation of arene radical cations enables an inversion of traditional SNAr selectivities such that electron-rich aromatics are selectively functionalized at an electron-donating C–O bond-containing substituent. This reaction mode enables the synthesis of aryl amines, fluoroarenes, and [18F]fluoroarenes. Additionally, we demonstrate that this reactivity pattern is dependent on the presence of a terminal oxidant, wherein its exclusion promotes selective C–O substitution over C–H functionalization. These two projects are covered in Chapters 4 and 6.Doctor of Philosoph

Management of paracondylar process fracture in three horses

Background: Fractures of the paracondylar process of the occipital bone may cause headshaking, neck pain and neurologic deficits. The condition is being recognised more frequently with increasing availability of computed tomography. However, to date only limited information is available as to presentation, treatment, surgical approach and outcome. Objectives: To describe the clinical signs, imaging findings, treatment, surgical approach and outcome in three horses diagnosed with paracondylar process fracture. Study design: Retrospective case series. Methods: Clinical records and diagnostic images of affected cases were reviewed. Results: Two cases had ventral nonunion fractures—one of these presented with neck pain, headshaking and behavioural changes, while in the other the fracture was a suspected incidental finding in a case of poor performance. A third case with a more dorsal fracture presented with acute facial nerve paralysis. Diagnosis was by computed tomography in all cases, although imaging of ventral fractures by radiography was found to be feasible. Where clinical signs could be associated confidently with the fracture, conservative management resulted in improvement but not complete resolution. Repeated recurrence of clinical signs after prolonged periods of remission necessitated surgical removal in one case, which was readily accomplished with the aid of ultrasound guidance, and led to rapid resolution of clinical signs without significant post-operative complications. The surgical approach is described. Main limitations: Limited follow-up was available. Conclusions: Paracondylar process fracture should be considered as a differential diagnosis for headshaking, neck pain, poor performance and facial paresis, and is a justification for performing computed tomography in such cases. A multi-disciplinary approach is beneficial due to the potential for orthopaedic, neurologic, ophthalmologic and behavioural clinical signs, with additional need for expertise in diagnostic imaging and pain management. Surgical fragment removal should be considered for ventral fractures.</p

Investigation of campylobacter concisus gastric epithelial pathogenicity using AGS cells

Campylobacter concisus is an oral bacterium. Recent studies suggest that C. concisus may be involved in human gastric diseases. The mechanisms, however, by which C. concisus causes human gastric diseases have not been investigated. Here we examined the gastric epithelial pathogenicity of C. concisus using a cell culture model. Six C. concisus strains and the human gastric epithelial cell line AGS cells were used. IL-8 produced by AGS cells after incubation with C. concisus was measured using enzyme-linked immunosorbent assay (ELISA), and AGS cell apoptosis was determined by caspase 3/7 activities. The effects of C. concisus on actin arrangement in AGS cells was determined using fluorescence staining. The effects of C. concisus on global gene expression in AGS cells was determined by transcriptomic analysis and quantitative real-time PCR (qRT-PCR). The role of the upregulated CYP1A1 gene in gastric cancer survival was assessed using the Kaplan-Meier method. C. concisus induced production of IL-8 by AGS cells with strain variation. Significantly increased caspase 3/7 activities were observed in AGS cells incubated with C. concisus strains when compared to AGS cells without bacteria. C. concisus induced actin re-arrangement in AGS cells. C. concisus upregulated 30 genes in AGS cells and the upregulation of CYP1A1 gene was confirmed by qRT-PCR. The Kaplan-Meier analysis showed that upregulation of CYP1A1 gene is associated with worse survival in gastric cancer patients. Our findings suggest that C. concisus may play a role in gastric inflammation and the progression of gastric cancer. Further investigation in clinical studies is warranted

Phonon Polaritons in Monolayers of Hexagonal Boron Nitride.

Phonon polaritons in van der Waals materials reveal significant confinement accompanied with long propagation length: important virtues for tasks pertaining to the control of light and energy flow at the nanoscale. While previous studies of phonon polaritons have relied on relatively thick samples, here reported is the first observation of surface phonon polaritons in single atomic layers and bilayers of hexagonal boron nitride (hBN). Using antenna-based near-field microscopy, propagating surface phonon polaritons in mono- and bilayer hBN microcrystals are imaged. Phonon polaritons in monolayer hBN are confined in a volume about one million times smaller than the free-space photons. Both the polariton dispersion and their wavelength-thickness scaling law are altered compared to those of hBN bulk counterparts. These changes are attributed to phonon hardening in monolayer-thick crystals. The data reported here have bearing on applications of polaritons in metasurfaces and ultrathin optical elements

Lets Talk about Race: Identity, Chatbots, and AI

Why is it so hard for chatbots to talk about race? This work explores how the biased contents of databases, the syntactic focus of natural language processing, and the opaque nature of deep learning algorithms cause chatbots difficulty in handling race-talk. In each of these areas, the tensions between race and chatbots create new opportunities for people and machines. By making the abstract and disparate qualities of this problem space tangible, we can develop chatbots that are more capable of handling race-talk in its many forms. Our goal is to provide the HCI community with ways to begin addressing the question, how can chatbots handle race-talk in new and improved ways