Hedging Effectiveness under Conditions of Asymmetry

We examine whether hedging effectiveness is affected by asymmetry in the return distribution by applying tail specific metrics to compare the hedging effectiveness of short and long hedgers using crude oil futures contracts. The metrics used include Lower Partial Moments (LPM), Value at Risk (VaR) and Conditional Value at Risk (CVAR). Comparisons are applied to a number of hedging strategies including OLS and both Symmetric and Asymmetric GARCH models. Our findings show that asymmetry reduces in-sample hedging performance and that there are significant differences in hedging performance between short and long hedgers. Thus, tail specific performance metrics should be applied in evaluating hedging effectiveness. We also find that the Ordinary Least Squares (OLS) model provides consistently good performance across different measures of hedging effectiveness and estimation methods irrespective of the characteristics of the underlying distribution

Improved surface quality of anisotropically etched silicon {111} planes for mm-scale integrated optics

We have studied the surface quality of millimeter-scale optical mirrors produced by etching CZ and FZ silicon wafers in potassium hydroxide to expose the $\{111\}$ planes. We find that the FZ surfaces have four times lower noise power at spatial frequencies up to $500\, {mm}^{-1}$. We conclude that mirrors made using FZ wafers have higher optical quality

The Microbiota and Health Promoting Characteristics of the Fermented Beverage Kefir

peer-reviewedKefir is a complex fermented dairy product created through the symbiotic fermentation of milk by lactic acid bacteria and yeasts contained within an exopolysaccharide and protein complex called a kefir grain. As with other fermented dairy products, kefir has been associated with a range of health benefits such as cholesterol metabolism and angiotensin-converting enzyme (ACE) inhibition, antimicrobial activity, tumor suppression, increased speed of wound healing, and modulation of the immune system including the alleviation of allergy and asthma. These reports have led to increased interest in kefir as a focus of research and as a potential probiotic-containing product. Here, we review those studies with a particular emphasis on the microbial composition and the health benefits of the product, as well as discussing the further development of kefir as an important probiotic product.The authors are funded through the Teagasc Walsh Fellowship Scheme(2014025)and internal Teagasc funding(RMIS6486). BW is supported by the Canada Research Chairs Program and research in the Cotter laboratory is funded by SFI through the PI award “Obesibiotics”(11/PI/1137)and in the form of a center grant (APC Microbiome Institute Grant Number SFI/12/RC/2273)

Matter-wave grating distinguishing conservative and dissipative interactions

We propose an optical grating for matter waves that separates molecules depending on whether their interaction with the light is conservative or dissipative. Potential applications include fundamental tests of quantum mechanics, measurement of molecular properties and the ability to selectively prepare matter waves with different internal temperatures