The Electrochemical Oxidation of Organic Selenides and Selenoxides

The electrochemical oxidation of alkyl and aryl selenides was investigated in acetonitrile. The oxidation of diphenyl selenide and di(4‐methylphenyl) selenide led primarily to the formation of their respective selenoxides, which were identified by exhaustive coulometric oxidation and and analysis of the products. The selenoxide itself was not observed in the cyclic voltammetry of the selenide for two reasons: first, the protonation of the selenoxide by the acid formed from the reaction of water with the cation radical and second, the formation of a selenoxide hydrate. The formation of the hydrate with diphenyl selenoxide was verified by isolation of the dimethoxy derivative. In addition to the selenoxide, selenonium compounds, formed by the coupling of the oxidized material, were also observed. The alkyl selenides were generally oxidized at a lower potential than the aryl selenides. This trend is different from the sulfur analogues, where the aryl sulfides are easier to oxidize than their alkyl counterparts. As a result, the difference in their redox potentials is relatively small. These differences may occur because the oxidation of aryl sulfides is more likely to take place on the aromatic ring, which leads to a greater yield of the coupled products (about 100%) when compared to the selenide analogue

Twisted Quasimaps and Symplectic Duality for Hypertoric Spaces

We study moduli spaces of twisted quasimaps to a hypertoric variety $X$, arising as the Higgs branch of an abelian supersymmetric gauge theory in three dimensions. These parametrise general quiver representations whose building blocks are maps between rank one sheaves on $\mathbb{P}^1$, subject to a stability condition, associated to the quiver, involving both the sheaves and the maps. We show that the singular cohomology of these moduli spaces is naturally identified with the Ext group of a pair of holonomic modules over the `quantized loop space' of $X$, which we view as a Higgs branch for a related theory with infinitely many matter fields. We construct the coulomb branch of this theory, and find that it is a periodic analogue of the coulomb branch associated to $X$. Using the formalism of symplectic duality, we derive an expression for the generating function of twisted quasimap invariants in terms of the character of a certain tilting module on the periodic coulomb branch. We give a closed formula for this generating function when $X$ arises as the abelianisation of the $N$-step flag quiver.Comment: 46 pages. Minor changes, typos fixed. Comments are very welcom

Elliptic stable envelopes and hypertoric loop spaces

This paper relates the elliptic stable envelopes of a hypertoric variety $X$ with the K-theoretic stable envelopes of the loop hypertoric space, $\widetilde{\mathscr{L}}X$. It thus points to a possible categorification of elliptic stable envelopes.Comment: 25 pages. Many changes and corrections are implemented, including a substantially modified final section. Comments are very welcome

Dynamics between Direct Industrial Real Estate and the Macroeconomy: An Empirical Study of Hong Kong

Pricing of direct industrial real estate (DIRE) has long been under-researched due to the paucity of analysable data. Compared to other types of real estate, DIRE has often been regarded as more inefficient because of information asymmetry amongst market players stemming from a lack of market transparency. Therefore, pricing of DIRE usually does not follow a random walk and should be more predictable than other types of real estate. Along this line of reasoning, this study empirically investigates the causal relationships between the price-to-rent ratio of DIRE and macroeconomic attributes using cointegration and causality techniques. More specifically, we employ data on the market of Hong Kong to investigate the lead-lag relationships between the price-to-rent ratio of DIRE and a wide spectrum of macroeconomic and financial indicators, including inflation, money supply, national income, exchange rates, performance of housing market and other economic indicators specific to the industrial sector. The results of our statistical tests reveal significant evidence that DIRE is generally moving in syncs with other segments of the economy over time in terms of long-term cointegration. Further, DIRE tends to lag behind the overall macroeconomy in terms of Granger causation with the price-to-rent ratio exhibiting varying lengths of time lag with the macroeconomic determinants. The findings of the study carry important implications for informing property valuation practices and industrial land policy, particularly in designing urban revitalization programmes aimed at optimising industrial land use

Lead-lag relationship between the price-to-rent ratio and the macroeconomy: An empirical study of the residential market of Hong Kong

The price-to-rent (PtR) ratio is one of the most commonly used indicators to assess housing market conditions by policy makers and real estate practitioners. It is often employed as an economic barometer to detect whether a housing bubble exists and determine whether the property market has become unaffordable relative to historical trends. Despite a plethora of research studies on the PtR ratio in the housing literature, relatively little is known about its long-term dynamics with macroeconomic and financial determinants. By utilising time series data on the Hong Kong residential property market, this study examines the cointegration and causal relationships between a wide spectrum of macroeconomic indicators and the PtR ratios of housing segments of different tiers which comprise different socioeconomic groups of homebuyers and investors. The results point towards market compartmentalisation, in the sense that the PtR ratios of the housing submarkets respond to changes in macroeconomic fundamentals in a differential manner. For instance, the PtR ratios of housing segments with a greater proportion of owner-occupiers are statistically less y correlated with investment-related macroeconomic attributes, such as foreign direct investment and equity market performance. On the other hand, the pricing of large-sized housing units in prime locations, generally favoured by investors from mainland China, are found to be Granger-caused by the exchange rate of the Chinese Yuan to the Hong Kong dollar

A robustified modeling approach to analyze pediatric length of stay

PurposeLength of stay (LOS) is an important measure of the cost of pediatric hospitalizations, but the guidelines developed so far are not rigorously evidence-based. This study demonstrates a robust gamma mixed regression approach to analyze the positively skewed LOS variable, which has implications for future studies of pediatric health care management.MethodsThe robustified approach is applied to analyze hospital discharge data on childhood gastroenteritis in Western Australia (n = 514). The model accounts for demographic characteristics and co-morbidities of the patients, as well as the dependency of LOS outcomes nested within the 58 hospitals in the State. The method is compared with the standard linear mixed regression with trimming of extreme observations.ResultsFor the empirical application, the linear mixed regression results are sensitive to the magnitude of trimming. The identified significant factors from the robust regression model, namely infection, failure to thrive, and iron deficiency anemia are resistant to high-LOS outliers.ConclusionsRobust gamma mixed regression appears to be a suitable alternative to analyze the clustered and positively skewed pediatric LOS, without transforming and trimming the data arbitrarily

Vocation Discernment and the Nurture of Pastoral Imagination in Female Interns at Tyndale Seminary

Looking at vocational discernment from the perspective of female pastoral interns