首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到11条相似文献,搜索用时 15 毫秒
1.
It is proved that formula for least squares extrapolation in stationary non‐linear AR(1) process is valid also for non‐stationary non‐linear AR(1) processes. This formula depends on the distribution of the corresponding white noise. If the non‐linear function used in the model is non‐decreasing and concave, upper and lower bounds are derived for least squares extrapolation such that the bounds depend only on the expectation of the white noise. It is shown in an example that the derived bounds in some cases give a good approximation to the least squares extrapolation. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

2.
This paper is concerned with the determination of simultaneous confidence regions for some types of time series models. We derive recursive formulas which allow the determination of the probability for an AR(1) stationary process based on exponential inputs to lie under any sequence of constants during N steps. Also, probabilities of the same form are derived for an MA(1) process, based on an exponentially distributed white noise. Numerical results are obtained and comparison of prediction regions for different values of ϕ or θ is made. The results show how the use of the correlation structure of the models can reduce the confidence regions area. © 1997 by John Wiley & Sons, Ltd.  相似文献   

3.
In this paper we extend the works of Baillie and Baltagi (1999, in Analysis of Panels and Limited Dependent Variables Models, Hsiao C et al. (eds). Cambridge University Press: Cambridge, UK; 255–267) and generalize certain results from the Baltagi and Li (1992, Journal of Forecasting 11 : 561–567) paper accounting for AR(1) errors in the disturbance term. In particular, we derive six predictors for the one‐way error components model, as well as their associated asymptotic mean squared error of multi‐step prediction in the presence of AR(1) errors in the disturbance term. In addition, we also provide both theoretical and simulation evidence as to the relative efficiency of our alternative predictors. The adequacy of the prediction AMSE formula is also investigated by the use of Monte Carlo methods and indicates that the ordinary optimal predictor performs well for various accuracy criteria. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

4.
The power transformation of Box and Cox (1964) has been shown to be quite useful in short-term forecasting for the linear regression model with AR(1) dependence structure (see, for example, Lee and Lu, 1987, 1989). It is crucial to have good estimates of the power transformation and serial. correlation parameters, because they form the basis for estimating other parameters and predicting future observations. The prediction of future observations is the main focus of this paper. We propose to estimate these two parameters by minimizing the mean squared prediction errors. These estimates and the corresponding predictions compare favourably, via revs and simulated data, with those obtained by the maximum likelihood method. Similar results are also demonstrated in the repeated measurements setting.  相似文献   

5.
Summary Synergistic effects of TA on gibberellin-dependent reactions in spermatophytes are not detectable in gametophytes of the fernAnemia phyllitidis where gibberellin substitutes for antheridiogens with regard to induction of male sexual organs and dark germination. In this archegoniate TA caused a significant reduction in growth rate and morphogenesis of the gametophytes, inhibitions that were not abolished by simultaneous application of gibberellin.  相似文献   

6.
Summary The failure of Australian goats fedLeucaena leucocephala (leucaena) to degrade 3-hydroxy-4(1H) pyridone (DHP), the goitrogenic metabolite of mimosine, was overcome when they were infused with rumen fluid from an Indonesían goat. The leucaena toxicity problem in Australia may well be solved by transfer of specific bacteria capable of degrading DHP anaerobically.We acknowkledge the assistance of R.G. Megarrity in preparation of the goats in Australia and R. Dixon and staff at the CSIRO Lansdown Research Station for preparation of the feed. In Balai Penelitian Ternak; G. Riding, and Suwandi for the metabolism study facilities, Riad the feeding, Miss Leanne Rochanda sample preparation and Mrs M. Young for veterinary assistance. Analyses were carried out by R. Lowe, Jernih Rosida and Wildan.  相似文献   

7.
The DSCR1 (Adapt78) gene1 is transiently induced by stresses to temporarily protect cells against further potentially lethal challenges. However, chronic expression of the DSCR1 (Adapt78) gene has now been implicated in several pathological conditions including Alzheimer’s disease, Down syndrome and cardiac hypertrophy. Calcipressin 1 has been shown to function through direct binding and inhibition of the serine threonine protein phosphatase Calcineurin. Pharmacological inhibition of calcineurin, by the immunosuppressive drugs cyclosporin A and FK506, affects a wide variety of diseases. It is, therefore, likely that this endogenous calcineurin inhibitor, calcipressin 1, may also play a role in a variety of human diseases. 1Please note that the mammalian DSCR1 gene is also called Adapt78 or RCAN1, and its protein products have been named Calcipressin1, MCIP1 and RCAN1. A proposal to adopt a single gene name of RCAN1 and a protein name RCAN1 (for Regulator of Calcineurin) has been endorsed by the HUGO Gene Nomenclature Committee, but final approval must await agreement from a majority of researchers in the field. Received 2 March 2005; received after revision 27 May 2005; accepted 19 July 2005  相似文献   

8.
Summary 1-(Substituted)benzyl-5-aminoimidazole-4-carboxamides are potent orally active inhibitors ofTrypanosoma cruzi infections in mice. The most active compounds are the 1-(4-chlorobenzyl)- and 1-(3,4-dichlorobenzyl)-analogs (L-153,094 [2] and L-153,153 [4], resp.) which are approximately 7-fold more potent upon oral administration than nifurtimox (Lampit) in suppressing parasite levels in the blood of mice with acuteTrypanosoma cruzi infections.  相似文献   

9.
Poly(ADP-ribose) (PAR) has been identified as a DNA damage-inducible cell death signal upstream of apoptosis-inducing factor (AIF). PAR causes the translocation of AIF from mitochondria to the nucleus and triggers cell death. In living cells, PAR molecules are subject to dynamic changes pending on internal and external stress factors. Using RNA interference (RNAi), we determined the roles of poly(ADP-ribose) polymerases-1 and -2 (PARP-1, PARP-2) and poly(ADP-ribose) glycohydrolase (PARG), the key enzymes configuring PAR molecules, in cell death induced by an alkylating agent. We found that PARP-1, but not PARP-2 and PARG, contributed to alkylation-induced cell death. Likewise, AIF translocation was only affected by PARP-1. PARP-1 seems to play a major role configuring PAR as a death signal involving AIF translocation regardless of the death pathway involved. Received 7 November 2007; received after revision 19 December 2007; accepted 21 December 2007 O. Cohausz, C. Blenn: These two authors contributed equally to this work.  相似文献   

10.
A population of uterine natural killer (NK) cells, commonly called granulated metrial gland (GMG) cells, differentiates in the mouse uterus during normal pregnancy. Little is known regarding the process of differentiation of GMG cells or of other NK cell subsets. It has been suggested that macrophage precursors, under the combined influences of the cytokine growth factors colony stimulating factor-1 (CSF-1) and interleukin-2, become NK-cell like in morphology, pattern of target cell lysis and surface antigen phenotype. Mice expressing the mutation osteopetrosis (op/op) are unable to produce the cytokine CSF-1. To determine whether CSF-1 is required for the successful differentiation of uterine NK cells, implantation sites in pregnant,op/op mice were studied histologically. GMG cell differentiation appeared to progress normally inop/op mice studied between days 7 and 14 of gestation. Thus, the growth factor CSF-1 is not required for differentiation of the uterine NK cell subset known as GMG cells and probably GMG cells do not differentiate from macrophage precursor cells which are deficient inop/op mice.  相似文献   

11.
The maximum consumption of the larvae of the pest and vector mosquitoCulex quinquefasciatus by the predatory mosquitoCulex (Lutzia) raptor was studied at various instars of both the predator and the prey. The prey preferences of the predator when given lavae of different instars were also investigated. The IVth instar of the predator consumed the maximum number of Ist instar and the maximum biomass of IVth instar larvae of the prey. Instars I and II of the predator preferred the Ist of the prey; instars III and IV of the predator preferred instars II and III of the prey respectively.The predator consumed an average of 157.1 larvae during its whole larval period, when each instar of the predator was given its preferred instar of the prey.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号