Robustness of alternative non‐linearity tests for SETAR models

In recent years there has been a growing interest in exploiting potential forecast gains from the non‐linear structure of self‐exciting threshold autoregressive (SETAR) models. Statistical tests have been proposed in the literature to help analysts check for the presence of SETAR‐type non‐linearities in an observed time series. It is important to study the power and robustness properties of these tests since erroneous test results might lead to misspecified prediction problems. In this paper we investigate the robustness properties of several commonly used non‐linearity tests. Both the robustness with respect to outlying observations and the robustness with respect to model specification are considered. The power comparison of these testing procedures is carried out using Monte Carlo simulation. The results indicate that all of the existing tests are not robust to outliers and model misspecification. Finally, an empirical application applies the statistical tests to stock market returns of the four little dragons (Hong Kong, South Korea, Singapore and Taiwan) in East Asia. The non‐linearity tests fail to provide consistent conclusions most of the time. The results in this article stress the need for a more robust test for SETAR‐type non‐linearity in time series analysis and forecasting. Copyright © 2004 John Wiley & Sons, Ltd.     

The gene encoding ganglioside-induced differentiation-associated protein 1 is mutated in axonal Charcot-Marie-Tooth type 4A disease.

We identified three distinct mutations and six mutant alleles in GDAP1 in three families with axonal Charcot-Marie-Tooth (CMT) neuropathy and vocal cord paresis, which were previously linked to the CMT4A locus on chromosome 8q21.1. These results establish the molecular etiology of CMT4A (MIM 214400) and suggest that it may be associated with both axonal and demyelinating phenotypes.     

Fire Retardant Textiles: A Particular Reference to China and Kenya

ＴｅｘｔｉｌｅａｎｄＵｎｃｏｎｔｒｏｌｌｅｄＦｉｒｅｓ　　Ｔｅｘｔｉｌｅｓａｒｅｔｈｅｔｈｉｒｄｂａｓｉｃｒｅｑｕｉｒｅｍｅｎｔｆｏｒｈｕｍａｎｌｉｆｅａｆｔｅｒｆｏｏｄａｎｄｓｈｅｌｔｅｒ.Ｔｅｘｔｉｌｅｓａｒｅｕｓｅｄｆｏｒｔｈｅｒｍａｌｐｒｏｔｅｃｔｉｏｎａｇａｉｎｓｔｈｏｓｔｉｌｅｗｅａｔｈｅｒａｎｄｔｏｃｏｖｅｒｎａｋｅｄｎｅｓｓ.Ｔｅｘｔｉｌｅｓａｌｓｏｐｒｏｖｉｄｅｃｏｍ ｆｏｒｔｉｎｌｉｆｅｉｎｔｈｅｆｏｒｍｏｆｆｕｒｎｉｓｈｉｎｇｓ :ｕｐｈｏｌｓｔｅｒｙ ,ｃａｒｐｅｔｓ ,ｅｔｃ .…     

Alpha- and beta-adrenergic receptors in rat myocardium membranes after prolonged ethanol inhalation

Summary After 3 weeks of continuous ethanol intoxication by inhalation, the maximal number and affinity of the -and -receptors of rat heart were unchanged. These data indicate that adrenergic receptor disturbances are not involved in the mechanism of chronic ethanol-induced triglyceride deposition in the heart.Acknowledgments. This work was supported by grants from the Institut National de la Santé et de la Recherche Médicale. We wish to thank Mr M. Clément for skilled technical assistance in performing chronic ethanol inhalation treatments.     

Structure,biosynthesis and functions of glycoprotein glycans

Since the pioneering work on structure and function of heteroglycans compiled in the classical books edited by A. Gottschalk in 1972¹, there have been several promising developments in glycoconjugate research, as reviewed in this article.In Part 1, contributed by A. Kobata, current knowledge on heteroglycan structures is presented and representative examples taken from higher organisms are given. Part 2, written by J. F. G. Vliegenthart and J. P. Kamerling, covers the most important achievements in methodology: procedures to obtain pure glycans and to analyze their structures. Part 3, contributed by J. Paulson, is devoted to biosynthesis of glycans now describable as pathways since several of the glycosyltransferases have been isolated and analyzed for specificity. In Part 4, contributed by E. Buddecke, current knowledge on functional roles of glycans is presented. It will become apparent that the prerequisite for valid work either in biosynthetic or functional context depends on solid structural information. This is particularly true whenever glycosyltransferase reaction products are being analyzed, or glycans involved in biological functions are investigated. Although in past years, a great deal of important knowledge has been gathered by use of crude glycosidase or glycosyltransferase activities (a notable example is found in reference 2), one may now postulate that glycans implicated in biological reactions should be thoroughly analyzed.This review may familiarize newcomers with the field of glycoconjugate research with special emphasis on glycoprotein glycans. Glycolipids are not included in this article as they have recently been reviewed by S. I. Hakomori³. The reader is also referred to several excellent monographs^4,5 and the Proceedings of the Glycoconjugate Symposia held biannually^6–8.     

Early eighteenth-century Newtonianism: the Huguenot contribution

John Theophilus Desaguliers’s allegorical poem The Newtonian system of the world, the best model of government (1728) crystallizes the contribution of several important French Protestant exiles to the construction of early Newtonianism. In the context of diverging interpretations of Newton’s scientific achievement in terms of natural religion, writers such as Des Maizeaux, Coste, Le Clerc and others actively disseminated a version of Newtonianism which was close to Newton’s own intention. Through public experiments, translations, correspondence, reviews and books, they managed to convey a vision of Newtonian science which coincided with their propaganda of English liberties in Church and State. Therefore their effort on behalf of Newtonianism can be interpreted as part of a wider strategy of assimilation into English society at a time when most exiled Huguenots had given up hope of ever recreating a French Reformed Church at home.     

Giving up on convergence and autonomy: Why the theories of psychology and neuroscience are codependent as well as irreconcilable

There is a long-standing debate in the philosophy of mind and philosophy of science regarding how best to interpret the relationship between neuroscience and psychology. It has traditionally been argued that either the two domains will evolve and change over time until they converge on a single unified account of human behaviour, or else that they will continue to work in isolation given that they identify properties and states that exist autonomously from one another (due to the multiple-realizability of psychological states). In this paper, I argue that progress in psychology and neuroscience is contingent on the fact that both of these positions are false. Contra the convergence position, I argue that the theories of psychology and the theories of neuroscience are scientifically valuable as representational tools precisely because they cannot be integrated into a single account. However, contra the autonomy position, I propose that the theories of psychology and neuroscience are deeply dependent on one another for further refinement and improvement. In this respect, there is an irreconcilable codependence between psychology and neuroscience that is necessary for both domains to improve and progress. The two domains are forever linked while simultaneously being unable to integrate.     

A Simple Linear Regression Approach to Modeling and Forecasting Mortality Rates

Observing that a sequence of negative logarithms of 1‐year survival probabilities displays a linear relationship with the sequence of corresponding terms with a time lag of a certain number of years, we propose a simple linear regression to model and forecast mortality rates. Our model assuming the linearity between two mortality sequences with a time lag each other does not need to formulate the time trends of mortality rates across ages for mortality prediction. Moreover, the parameters of our model for a given age depend on the mortality rates for that age only. Therefore, whether the span of the study ages with the age included is widened or shortened will not affect the results of mortality fitting and forecasting for that age. In the empirical testing, the regression results using the mortality data for the UK, USA and Japan show a satisfactory goodness of fit, which convinces us of the appropriateness of the linear assumption. Empirical illustrations further show that our model's performances of fitting and forecasting mortality rates are quite satisfactory compared with the existing well‐known mortality models. Copyright © 2015 John Wiley & Sons, Ltd.     

WTI crude oil option implied VaR and CVaR: An empirical application

Using option market data we derive naturally forward‐looking, nonparametric and model‐free risk estimates, three desired characteristics hardly obtainable using historical returns. The option‐implied measures are only based on the first derivative of the option price with respect to the strike price, bypassing the difficult task of estimating the tail of the return distribution. We estimate and backtest the 1%, 2.5%, and 5% WTI crude oil futures option‐implied value at risk and conditional value at risk for the turbulent years 2011–2016 and for both tails of the distribution. Compared with risk estimations based on the filtered historical simulation methodology, our results show that the option‐implied risk metrics are valid alternatives to the statistically based historical models.