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Indirect Test (indirect + test)
Selected AbstractsFutures trading and the storage of North American natural gasOPEC ENERGY REVIEW, Issue 1 2006Apostolos Serletis This paper tests the theory of storage in North American natural gas markets, using the Fama and French (1988) indirect test. In particular, we test the theory's prediction that when inventory is high, large inventory responses to shocks imply roughly equal changes in spot and futures prices, whereas when inventory is low, smaller inventory responses to shocks imply larger changes in spot prices than in futures prices. Our tests on spot and futures North American natural gas prices confirm these predictions of the theory of storage. [source] Advantages of deuterium-labelled mixed triacylglycerol in studies of intraluminal fat digestionRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 2 2006Christine Slater The 13C-mixed triacylglcerol (MTG, 1,3-distearyl, 2-[1- 13C]octanoyl glycerol) breath test is a non-invasive measure of intraluminal fat digestion. Recovery of 13C in breath CO2 is incomplete (<50%) owing to sequestration of 13C into organic molecules via the tricarboxylic acid (TCA) cycle. In addition lack of knowledge of CO2 production rate (VCO2) during the test leads to errors in the calculated percentage dose recovered (PDR). 2H sequestration into organic molecules is low (,4%) and is not influenced by factors that affect VCO2 such as food intake or physical activity. After oxidation of 2H-labelled macromolecules, the label appears in body water, which can be sampled non-invasively in urine or saliva. After an overnight fast, two healthy adults consumed [2H]MTG (1,3-distearyl, 2-[2H15]octanoyl glycerol) and [13C]MTG (1,3 distearyl, 2-[1- 13C]octanoyl glycerol) simultaneously. Total body water (TBW) was measured by 18O dilution and also estimated from height and weight. Urine and saliva were sampled at baseline and for 10,h after consumption of the test meal. The abundance of 2HOH and H218O in urine and saliva was measured by continuous-flow isotope-ratio mass spectrometry. Cumulative PDR of 2H and 18O was calculated from the plateau enrichment, which was reached by 6,h in both saliva and urine. Recovery of 2H calculated using measured TBW was compared with that using an estimated value of TBW. Mean recovery of 2H in saliva was 99.3% and in urine was 96.4%. Errors introduced by estimating TBW were <5%. [2H]MTG could provide a simpler, more robust, indirect test of intraluminal fat digestion compared with the 13C-breath test. Further studies are required in pancreatic insufficient patients. Copyright © 2005 John Wiley & Sons, Ltd. [source] Asymmetric volatility of basis and the theory of storageTHE JOURNAL OF FUTURES MARKETS, Issue 4 2005Andre H. Gao The theory of storage states that the marginal convenience yield on inventory falls at a decreasing rate as inventory increases. Previous literature has tested this hypothesis using the so-called "direct test" approach, which employs a direct measurement of inventory levels, or the "indirect test" approach, which examines the relative variation of spot and futures prices and the relative variation of negative basis to positive basis as alternative proxies for inventory levels. The rationale behind the indirect test is based on the hypothesis that futures prices are less variable than spot prices when inventory is low, and have similar variability when inventory is high. The authors propose a "unified test" of the theory of storage that incorporates aspects of both direct and indirect tests in an ARMAX-asymmetric GARCH model framework. © 2005 Wiley Periodicals, Inc. Jrl Fut Mark 25:399,418, 2005 [source] | ||||||||||