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81.
The purpose of this paper is to build an alternative method of bankruptcy prediction that accounts for some deficiencies in previous approaches that resulted in poor out‐of‐sample performances. Most of the traditional approaches suffer from restrictive presumptions and structural limitations and fail to reflect the panel properties of financial statements and/or the common macroeconomic influence. Extending the work of Shumway (2001), we present a duration model with time‐varying covariates and a baseline hazard function incorporating macroeconomic dependencies. Using the proposed model, we investigate how the hazard rates of listed companies in the Korea Stock Exchange (KSE) are affected by changes in the macroeconomic environment and by time‐varying covariate vectors that show unique financial characteristics of each company. We also investigate out‐of‐sample forecasting performances of the suggested model and demonstrate improvements produced by allowing temporal and macroeconomic dependencies. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
82.
Summary Methods are presented for qualifying clinical reference intervals, for individuals as well as peer groups, according to circadian and other rhythms, using chronobiologically-defined single samples or time series.Supported by the Hoechst Italia Foundation, US Environmental Protection Agency (R804512-01-0), US Public Health Service (5-K6-GM-13, 981), National Cancer Institute (1R01-CA-14446-01), Cancer Supplement (CA-14445-01S1), National Institute of Aging (A6-00158) and National Institute of Occupational Safety and Health (OH 00631). 相似文献
83.
84.
B. Urbaschek R. Urbaschek G. Mauff Ch. Gerlach K. Huth F. Jung R. -H. Ringert A. Nowotny H. Fritsch 《Cellular and molecular life sciences : CMLS》1971,27(7):803-805
Zusammenfassung Vor dem Hintergrund der vielfältigen Endotoxoidwirkung wurde diese Substanz in chronischen Toxizitätsstudien beiMacaca mulatta geprüft. Endotoxoid wurdeMacaca mulatta in einer Dosierung von jeweils 100/kg in insgesamt 51 Injektionen innerhalb von 12 Wochen injiziert. Dabei zeigte sich, dass diese Substanz keinen Einfluss auf die geprüften klinischchemischen Parameter hatte und bei makroskopischer und histologischer Untersuchung keine Veränderungen auftraten.
Kindly supported by a grant from the Deutsche Forschungsgemeinschaft to Dr.Fritsch. 相似文献
Kindly supported by a grant from the Deutsche Forschungsgemeinschaft to Dr.Fritsch. 相似文献
85.
郭承华 Liu Wanshun Han Baoqin Dong Xinwei Liu Chuanlin Hu Dan Soon-Teck Jung 《高技术通讯(英文版)》2006,12(2):198-202
The full fats of Asterina pectinifera in Huanghai Sea were extracted and refined using solvent extraction combined with silica gel colmnn chromatography with yield of 1.64%. The full fats were analyzed by gas chromatography and the result indicated that the full fats from Asterina pectinifera contained abundant Polyunsaturated Fatty Acid (PUFA) with a total of 25 kinds, especially rich in EPA and DHA. After enrichment by silica gel colmnn chromatography, the total PUFA content in ligarine fraction is 42.20%, in which EPA and DHA account for 12.50% and 10.33% respectively. The total PUFA content in acetic ether fraction is 48.98%, in which EPA and DHA take up 17.53% and 6.59% respectively. The total amount of EPA and DHA in both fractions all exceeded that of the fish oil from deep sea. In conclusion, the Asterina pectinifera in Huanghai Sea is a favorable source of PUFA. 相似文献
86.
In vivo priming of virus-specific cytotoxic T lymphocytes with synthetic lipopeptide vaccine 总被引:48,自引:0,他引:48
Cytotoxic T lymphocytes (CTL) constitute an essential part of the immune response against viral infections. Such CTL recognize peptides derived from viral proteins together with major histocompatibility complex (MHC) class I molecules on the surface of infected cells, and usually require in vivo priming with infectious virus. Here we report that synthetic viral peptides covalently linked to tripalmitoyl-S-glycerylcysteinyl-seryl-serine (P3CSS) can efficiently prime influenza-virus-specific CTL in vivo. These lipopeptides are able to induce the same high-affinity CTL as does the infectious virus. Our data are not only relevant to vaccine development, but also have a bearing on basic immune processes leading to the transition of virgin T cells to activated effector cells in vivo, and to antigen presentation by MHC class I molecules. 相似文献
87.
88.
Jongsung Lee Eunsun Jung Jienny Lee Sungran Huh Young-Soo Kim Yong-Woo Kim Yeong Shik Kim Deokhoon Park 《Cellular and molecular life sciences : CMLS》2010,67(3):467-481
Adipocyte dysfunction is associated with the development of obesity. This study shows that 6-thioinosine inhibits adipocyte
differentiation. The mRNA levels of PPAR γ and C/EBPα, but not C/EBPβ and δ, were reduced by 6-thioinosine. Moreover, the
mRNA levels of PPAR γ target genes (LPL, CD36, aP2, and LXRα) were down-regulated by 6-thioinosine. We also demonstrated that
6-thioinosine inhibits the transactivation activity and the mRNA level of PPAR γ. Additionally, attempts to elucidate a possible
mechanism underlying the 6-thioinosine-mediated effects revealed that 6-thioinosine induced iNOS gene expression without impacting
eNOS expression, and that this was mediated through activation of AP-1, especially, JNK. In addition, 6-thioinosine was found
to operate upstream of MEKK-1 in JNK activation signaling. Taken together, these findings suggest that the inhibition of adipocyte
differentiation by 6-thioinosine occurs primarily through the reduced expression of PPAR γ, which is mediated by upregulation
of iNOS via the activation of JNK. 相似文献
89.
Time series forecasting using functional partial least square regression with stochastic volatility,GARCH, and exponential smoothing
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We propose a method for improving the predictive ability of standard forecasting models used in financial economics. Our approach is based on the functional partial least squares (FPLS) model, which is capable of avoiding multicollinearity in regression by efficiently extracting information from the high‐dimensional market data. By using its well‐known ability, we can incorporate auxiliary variables that improve the predictive accuracy. We provide an empirical application of our proposed methodology in terms of its ability to predict the conditional average log return and the volatility of crude oil prices via exponential smoothing, Bayesian stochastic volatility, and GARCH (generalized autoregressive conditional heteroskedasticity) models, respectively. In particular, what we call functional data analysis (FDA) traces in this article are obtained via the FPLS regression from both the crude oil returns and auxiliary variables of the exchange rates of major currencies. For forecast performance evaluation, we compare out‐of‐sample forecasting accuracy of the standard models with FDA traces to the accuracy of the same forecasting models with the observed crude oil returns, principal component regression (PCR), and least absolute shrinkage and selection operator (LASSO) models. We find evidence that the standard models with FDA traces significantly outperform our competing models. Finally, they are also compared with the test for superior predictive ability and the reality check for data snooping. Our empirical results show that our new methodology significantly improves predictive ability of standard models in forecasting the latent average log return and the volatility of financial time series. 相似文献
90.
In Ha Cho Min Jung Lee Dae Hwan Kim Bora Kim Jeomil Bae Kyu Yeong Choi Seon-Myung Kim Yun Hyun Huh Kun Ho Lee Chong-Hyun Kim Woo Keun Song 《Cellular and molecular life sciences : CMLS》2013,70(22):4369-4383
Actin plays a fundamental role in the regulation of spine morphology (both shrinkage and enlargement) upon synaptic activation. In particular, actin depolymerization is crucial for the spine shrinkage in NMDAR-mediated synaptic depression. Here, we define the role of SPIN90 phosphorylation/dephosphorylation in regulating actin depolymerization via modulation of cofilin activity. When neurons were treated with NMDA, SPIN90 was dephosphorylated by STEP61 (striatal-enriched protein tyrosine phosphatase) and translocated from the spines to the dendritic shafts. In addition, phosphorylated SPIN90 bound cofilin and then inhibited cofilin activity, suggesting that SPIN90 dephosphorylation is a prerequisite step for releasing cofilin so that cofilin can adequately sever actin filaments into monomeric form. We found that SPIN90 YE, a phosphomimetic mutant, remained in the spines after NMDAR activation where it bound cofilin, thereby effectively preventing actin depolymerization. This led to inhibition of the activity-dependent redistribution of cortactin and drebrin A, as well as of the morphological changes in the spines that underlie synaptic plasticity. These findings indicate that NMDA-induced SPIN90 dephosphorylation and translocation initiates cofilin-mediated actin dynamics and spine shrinkage within dendritic spines, thereby modulating synaptic activity. 相似文献