4,234 research outputs found
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 planes. We find that the FZ surfaces have four times lower noise
power at spatial frequencies up to . 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
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