bluuebunny/crossref_metadata_2025_split huggingface dataset:
Empirical analysis and forecasting of volatility dynamics in high‐frequency returns with time‐varying components
Authors: Man Kasing , Wu Chunchi 
Published: October 2009

AbstractWe study intraday return volatility dynamics using a time‐varying components approach, and the method is applied to analyze IBM intraday returns. Empirical evidence indicates that with three additive components—a time‐varying mean of absolute returns and two cosine components with time‐varying amplitudes—together they capture very well the pronounced periodicity and persistence behaviors exhibited in the empirical autocorrelation pattern of IBM returns. We find that the long‐run volatility persistence is driven predominantly by daily level shifts in mean absolute returns. After adjusting for these intradaily components, the filtered returns behave much like a Gaussian noise, suggesting that the three‐components structure is adequately specified. Furthermore, a new volatility measure (TCV) can be constructed from these components. Results from extensive out‐of‐sample rolling forecast experiments suggest that TCV fares well in predicting future volatility against alternative methods, including GARCH model, realized volatility and realized absolute value. Copyright © 2009 John Wiley & Sons, Ltd.
How sensitive is physician performance to alternative compensation schedules? Evidence from a large network of primary care clinics
Authors: Helmchen Lorens A. , Lo Sasso Anthony T. 
Published: October 2009

AbstractDespite its centrality for the provision of health care, physician compensation remains understudied, and existing studies either fail to control for time trends, cover small samples from highly particular settings, or examine empirically negligible changes in reward levels. Using a four‐year sample of 59 physicians and 1.1 million encounters, we study how physicians at a network of primary care clinics responded when their salaried compensation plan was replaced with a lower salary plus substantial piece rates for encounters and select procedures. Although patient characteristics remained unchanged, physicians increased encounters by 11 to 61%, both by increasing encounters per day and days worked at the network, and increased procedures to the maximum reimbursable level. Copyright © 2009 John Wiley & Sons, Ltd.
The possible macroeconomic impact on the UK of an influenza pandemic
Authors: Keogh‐Brown Marcus R. , Wren‐Lewis Simon , Edmunds W. John , Beutels Philippe , Smith Richard D. 
Published: October 2009

AbstractLittle is known about the possible impact of an influenza pandemic on a nation's economy. We applied the UK macroeconomic model ‘COMPACT’ to epidemiological data on previous UK influenza pandemics, and extrapolated a sensitivity analysis to cover more extreme disease scenarios. Analysis suggests that the economic impact of a repeat of the 1957 or 1968 pandemics, allowing for school closures, would be short‐lived, constituting a loss of 3.35 and 0.58% of GDP in the first pandemic quarter and year, respectively. A more severe scenario (with more than 1% of the population dying) could yield impacts of 21 and 4.5%, respectively. The economic shockwave would be gravest when absenteeism (through school closures) increases beyond a few weeks, creating policy repercussions for influenza pandemic planning as the most severe economic impact is due to policies to contain the pandemic rather than the pandemic itself.Accounting for changes in consumption patterns made in an attempt to avoid infection worsens the potential impact. Our mild disease scenario then shows first quarter/first year reductions in GDP of 9.5/2.5%, compared with our severe scenario reductions of 29.5/6%. These results clearly indicate the significance of behavioural change over disease parameters. Copyright © 2009 John Wiley & Sons, Ltd.
Disruption of ripple‐associated hippocampal activity during rest impairs spatial learning in the rat
Authors: Ego‐Stengel Valérie , Wilson Matthew A. 
Published: October 2009

AbstractThe hippocampus plays a key role in the acquisition of new memories for places and events. Evidence suggests that the consolidation of these memories is enhanced during sleep. At the neuronal level, reactivation of awake experience in the hippocampus during sharp‐wave ripple events, characteristic of slow‐wave sleep, has been proposed as a neural mechanism for sleep‐dependent memory consolidation. However, a causal relation between sleep reactivation and memory consolidation has not been established. Here we show that disrupting neuronal activity during ripple events impairs spatial learning. We trained rats daily in two identical spatial navigation tasks followed each by a 1‐hour rest period. After one of the tasks, stimulation of hippocampal afferents selectively disrupted neuronal activity associated with ripple events without changing the sleep‐wake structure. Rats learned the control task significantly faster than the task followed by rest stimulation, indicating that interfering with hippocampal processing during sleep led to decreased learning. © 2009 Wiley‐Liss, Inc.
Essential role of tau phosphorylation in adult hippocampal neurogenesis
Authors: Hong Xiao‐Ping , Peng Cai‐Xia , Wei Wei , Tian Qing , Liu Ying‐Hua , Yao Xiu‐Qing , Zhang Yao , Cao Fu‐Yuan , Wang Qun , Wang Jian‐Zhi 
Published: October 2009

AbstractAn increased hippocampal neurogenesis has been observed in Alzheimer disease (AD), the most common neurodegenerative disorder characterized with accumulation of β‐amyloid (Aβ) and hyperphosphorylated tau (p‐tau). Studies in transgenic mouse models suggest that the amyloidosis suppresses adult neurogenesis. Although emerging evidence links tau to neurodevelopment, the direct data regarding tau phosphorylation in adult neurogenesis is missing. Here, we found that the immature neurons, identified by doublecortin (DCX) and neurogenic differentiation factor (neuroD), were only immunoreactive to p‐tau but not to the non‐p‐tau in adult rat brain and human patients with AD, and the p‐tau was coexpressed temporally and spatially with DCX and neuroD in the hippocampal dentate gyrus (DG) of the rat brains during postnatal development. A correlative increase of immature neuron markers and tau phosphorylation was induced in rat hippocampal DG by upregulating glycogen synthase kinase‐3 (GSK‐3), a crucial tau kinase, and the increased neurogenesis was due to an enhanced proliferation but not survival or differentiation of the newborn neurons. The hippocampal neurogenesis was severely impaired in tau knockout mice and activation of GSK‐3 in these mice did not rescue the deficits. These results reveal an essential role of tau phosphorylation in adult hippocampal neurogenesis. It suggests that spatial/temporal manipulation of tau phosphorylation may be compensatory for the neuron loss in neurological disorders, including AD. © 2009 Wiley‐Liss, Inc.
The Arf‐inducing transcription factor Dmp1 encodes a transcriptional activator of amphiregulin, thrombospondin‐1, JunB and Egr1
Authors: Mallakin Ali , Sugiyama Takayuki , Kai Fumitake , Taneja Pankaj , Kendig Robert D. , Frazier Donna P. , Maglic Dejan , Matise Lauren A. , Willingham Mark C. , Inoue Kazushi 
Published: October 2009

AbstractDmp1 (Dmtf1) encodes a Myb‐like transcription factor implicated in tumor suppression through direct activation of the Arf‐p53 pathway. The human DMP1 gene is frequently deleted in non‐small cell lung cancers, especially those that retain wild‐type INK4a/ARF and/or p53. To identify novel genes that are regulated by Dmp1, transcriptional profiles of lung tissue from Dmp1‐null and wild‐type mice were generated using the GeneChip Microarray. Comparative analysis of gene expression changes between the two groups resulted in identification of numerous genes that may be regulated by Dmp1. Notably, amphiregulin (Areg), thrombospondin‐1 (Tsp‐1), JunB, Egr1, adrenomedullin (Adm), Bcl‐3 and methyl‐CpG binding domain protein 1 (Mbd1) were downregulated in the lungs from Dmp1‐null mice while Gas1 and Ect2 genes were upregulated. These target genes were chosen for further analyses since they are involved in cell proliferation, transcription, angiogenesis/metastasis, apoptosis, or DNA methylation, and thus could account for the tumor suppressor phenotype of Dmp1. Dmp1 directly bound to the genomic loci of Areg, Tsp‐1, JunB and Egr1. Significant upregulation or downregulation of the novel Dmp1 target genes was observed upon transient expression of Dmp1 in alveolar epithelial cells, an effect which was nullified by the inhibition of de novo mRNA synthesis. Interestingly, these genes and their protein products were significantly downregulated or upregulated in the lungs from Dmp1‐heterozygous mice as well. Identification of novel Dmp1 target genes not only provides insights into the effects of Dmp1 on global gene expression, but also sheds light on the mechanism of haploid insufficiency of Dmp1 in tumor suppression.
Soluble glypican 3 inhibits the growth of hepatocellular carcinoma in vitro and in vivo
Authors: Zittermann Sandra I. , Capurro Mariana I. , Shi Wen , Filmus Jorge 
Published: October 2009

AbstractThe heterogeneity of the molecular pathology of HCC poses a formidable obstacle to the development of non‐cytotoxic therapies. Several pro‐tumorigenic signaling pathways can be aberrantly activated in HCC, including those triggered by Wnts. Glypican‐3 (GPC3), a membrane‐bound heparan sulfate proteoglycan that is overexpressed in most HCCs, promotes the growth of these tumors by stimulating Wnt signaling. Because GPC3 binds with high affinity to Wnts, and its growth‐promoting activity requires attachment to the cell membrane, we have hypothesized that a mutated GPC3 lacking the GPI anchoring domain (sGPC3) will block Wnt signaling and inhibit the growth of Wnt‐dependent tumors. In addition, because sGPC3 displays heparan sulfate chains, this secreted glypican could also inhibit HCC growth by blocking the activity of other heparin‐binding growth factors. To test this hypothesis, HCC cell lines were infected with an sGPC3‐expressing lentivirus or virus control, and the effect of sGPC3 on the in vitro and in vivo growth was investigated. In addition, the signaling pathways targeted by sGPC3 were identified. We observed that sGPC3‐expressing cells had lower proliferation rate. In addition, sGPC3 significantly inhibited the in vivo growth of the Huh6, HepG2 and Huh7 HCC cell lines. sGPC3 blocked Wnt signaling in Huh6‐ and Huh7‐derived tumors and Erk1/2 and Akt phosphorylation in tumors generated by Huh7 and HepG2 cells, respectively. An anti‐angiogenic effect in Huh7 and HepG2‐derived tumors was also observed. We conclude that sGPC3 can inhibit HCC tumorigenicity by blocking the activity of several pro‐tumorigenic growth factors.
Identification of G0S2 as a gene frequently methylated in squamous lung cancer by combination of in silico and experimental approaches
Authors: Kusakabe Masashi , Kutomi Tomoko , Watanabe Kousuke , Emoto Noriko , Aki Naomi , Kage Hidenori , Hamano Emi , Kitagawa Hiroshi , Nagase Takahide , Sano Atsushi , Yoshida Yukihiro , Fukami Takeshi , Murakawa Tomohiro , Nakajima Jun , Takamoto Shinichi , Ota Satoshi , Fukayama Masashi , Yatomi Yutaka , Ohishi Nobuya , Takai Daiya 
Published: October 2009

AbstractEpigenetic changes can lead to abnormal expression of genes in cancer, and several genes have been reported to have aberrant promoter DNA methylation in non‐small‐cell lung cancer (NSCLC). We identified aberrantly methylated genes in NSCLC by combination of in silico and experimental approaches. We first applied bioinformatics, and from microarray datasets, we selected genes with low expression and having functions related to cancer. Next, combined bisulfite restriction analysis was carried out in 10 pooled resected lung cancer tissues to screen for genes that were aberrantly methylated, and the methylation ratio (the fraction of methylated DNA in extracted DNA from a cancer tissue sample) was quantified using quantitative analysis of methylated alleles. We identified 8 methylated genes (ARPC1B, DNAH9, FLRT2, G0S2, IRS2, PKP1, SPOCK1 and UCHL1) previously unreported in NSCLC. Analyses of methylation profiles of 101 resected lung cancer tissue samples revealed quantitatively low methylation in whole, methylation ratios were almost less than 30% even in the methylated samples, and no significant correlation to prognosis after 2 years of follow‐up using hierarchical clustering. DNA methylation of G0S2 gene was significantly more frequent in squamous lung cancer (n = 18, mean of methylation ratios: 15%) compared with nonsquamous lung cancer (n = 83, mean of methylation ratios: 2.6%) (Mann‐Whitney U test, p < 0.001). DNA methylation of G0S2 can be an important biomarker for squamous lung cancer.
RNAi‐mediated MEK1 knock‐down prevents ERK1/2 activation and abolishes human hepatocarcinoma growth in vitro and in vivo
Authors: Gailhouste Luc , Ezan Frédéric , Bessard Anne , Frémin Christophe , Rageul Julie , Langouët Sophie , Baffet Georges 
Published: October 2009

AbstractThe mitogen‐activated protein kinases MEK/ERK pathway regulates fundamental processes in malignant cells and represents an attractive target in the development of new cancer treatments especially for human hepatocarcinoma highly resistant to chemotherapy. Although gene extinction experiments have suggested distinct roles for these proteins, the MEK/ERK cascade remains widely considered as exhibiting an overlap of functions. To investigate the functionality of each kinase in tumorigenesis, we have generated stably knock‐down clones for MEK1/2 and ERK1/2 isoforms in the human hepatocellular carcinoma line HuH7. Our results have shown that RNAi strategy allows a specific disruption of the targeted kinases and argued for the critical function of MEK1 in liver tumor growth. Transient and stable extinction experiments demonstrated that MEK1 isoform acts as a major element in the signal transduction by phosphorylating ERK1 and ERK2 after growth factors stimulation, whereas oncogenic level of ERK1/2 phosphorylation appears to be MEK1 and MEK2 dependent in basal condition. In addition, silencing of MEK1 or ERK2 abolished cell proliferation and DNA replication in vitro as well as tumor growth in vivo after injection in rodent. In contrast, targeting MEK2 or ERK1 had no effect on hepatocarcinoma progression. These results strongly corroborate the relevance of targeting the MEK cascade as attested by pharmacologic drugs and support the potential application of RNAi in future development of more effective cancer therapies. Our study emphasizes the importance of the MEK/ERK pathway in human hepatocarcinoma cell growth and argues for a crucial role of MEK1 and ERK2 in this regulation.
The clinical significance of tumor cells in bone marrow or apheresis product and the efficacy of CD34+ selection and high‐dose chemotherapy in patients with Stage III breast cancer
Authors: Arpaci Fikret , Safali Mukerrem , Ozet Ahmet , Ural Ali U. , Cetin Turker , Ozturk Mustafa , Ataergin Selmin , Kuzhan Okan , Komurcu Seref , Ozturk Bekir , Acikel Cengizhan 
Published: October 2009

AbstractThe purpose of this study is to determine the presence of disseminated tumor cells in bone marrow or apheresis product, and also to evaluate the clinical significance of contaminated products and the efficacy of CD34+ selection and high‐dose chemotherapy in patients with Stage III breast cancer. Fifty‐five patients were enrolled in this prospective cohort study. Whereas CD34+ positive selection was not carried out in the first group (unselected group, n:31), CD34+ positive selection was performed in the second group (CD34 selected group, n:24). Tumor cells were detected with anticytokeratin monoclonal antibody in the bone marrow, apheresis product and positive fraction. Tumor cells were found in six (19.3%) patients in unselected group and four patients (16.6%) in CD34 selected group (P = 0.76). The percentages of distant metastases were found higher in unselected group (51.6% vs. 25%, P < 0.01). Although there were no differences between the two groups for disease free survival (DFS; 44% vs. 74%, P = 0.24) or overall survival (54% vs. 68%, P = 0.84), DFS was significantly lower in patients with tumor cells than in patients without tumor cells (21% vs. 62%, P = 0.02). In conclusion, the presence of tumor cells in bone marrow or apheresis product decreases DFS in patients with Stage III breast cancer who underwent high‐dose chemotherapy. CD34+ selection does not change survivals, but it may decrease the distant metastases. J. Clin. Apheresis 2009. © 2009 Wiley‐Liss, Inc.
Effects of testosterone on morphology, performance and muscle mass in a lizard
Authors: Huyghe Katleen , Husak Jerry F. , Moore Ignacio T. , Vanhooydonck Bieke , Van Damme Raoul , Molina‐Borja Miguel , Herrel Anthony 
Published: October 2009

AbstractBecause sexual selection pressures are high in sexually dimorphic organisms, morphological, physiological and performance traits are often studied in a sexual selection context. The proximate mechanisms underlying evolutionary change in these traits, however, remain largely unstudied. Here, we examined the role of steroids in shaping morphology and physiological performance in males of a sexually dimorphic lizard (Gallotia galloti). We compared morphology and physiological performance of males with experimentally elevated testosterone levels to sham‐operated males. Before surgery, inter‐individual variation in plasma testosterone levels correlated positively with bite force capacity. Administration of exogenous testosterone resulted in an increase of the mass of both jaw closing and locomotory muscles compared with sham‐operated individuals, but the responsiveness varied considerably among muscle groups. In contrast to our expectations, the dramatic testosterone‐induced changes in muscle masses did not result in concordant changes in bite force performance or sprint speed.J. Exp. Zool. 313A:9–16, 2010. © 2009 Wiley‐Liss, Inc.
Rethinking the role of corporate social responsibility in the Nigerian oil conflict: The limits of CSR
Authors: Idemudia Uwafiokun 
Published: October 2009

AbstractThe widespread adoption of corporate social responsibility (CSR) by oil multinational corporations (MNCs) in Nigeria supposedly marked a watershed in corporate–community relations in the Niger Delta. This is because, after decades of initially rejecting such responsibilities, oil MNCs reversal of attitude towards CSR was expected to at least tamper the scale and intensity of violence. However, despite such widespread claims of adherence to the ideals of CSR, corporate–community conflict has remained unabated and oil companies continue to be accused of familiar misdemeanour. This paper argued that structural and systemic deficiencies inherent in CSR practices limit the effectiveness of CSR as a vehicle for conflict prevention and reduction in the Niger Delta. The paper concludes by considering the implications for CSR‐conflict nexuses in the Nigerian oil industry. Copyright © 2009 John Wiley & Sons, Ltd.
lipID—a software tool for automated assignment of lipids in mass spectra
Authors: Hübner Göran , Crone Catharina , Lindner Buko 
Published: October 2009

AbstractA new software tool called lipID is reported, which supports the identification of glycerophospholipids, glycosphingolipids, fatty acids and small oligosaccharides in mass spectra. The user‐extendable software is a Microsoft (MS) Excel Add‐In developed using Visual Basic for Applications and is compatible with all Versions of MS Excel since MS Excel 97. It processes singly given mass‐to‐charge values as well as mass lists considering a number of user‐defined options. The software's mode of operation, usage and options are explained and the benefits and limitations of the tool are illustrated by means of three typical analytical examples of lipid analyses. Copyright © 2009 John Wiley & Sons, Ltd.
Thermal analysis of multi‐finger GaInP collector‐up heterojunction bipolar transistors with miniature heat‐dissipation packaging structures
Authors: Lee Pei‐Hsuan , Tseng Hsien‐Cheng , Chou Jung‐Hua 
Published: October 2009

AbstractWe build up a finite element modeling (FEM) approach to analyze the thermal performance of collector‐up (C‐up) heterojunction bipolar transistor (HBTs) with a heat‐dissipation via configuration. Highly compact heat‐dissipation packaging structures of GaInP/GaAs C‐up HBTs have been designed and evaluated systematically. In this work, we devise the 2‐D and 3‐D models to simulate the actual devices and to investigate the temperature distribution behavior. Results from 2‐D model indicate that the large heat‐dissipation via configuration can be further reduced by 29% to meet the requirement of HBT‐based small high‐power amplifiers (HPAs) for the cellular phones. Furthermore, the demonstrated results show that the maximum temperature within the collector calculated from 3‐D model is lower than that from 2‐D model. In the 3‐D analysis, it is revealed that the configuration can be reduced by 32%. Therefore, thinning the heat‐dissipation via constructed underneath the GaInP/GaAs C‐up HBT should be helpful for miniaturization of HBT‐based HPAs in future mobile communication systems. Copyright © 2009 John Wiley & Sons, Ltd.
Multiple criticality and staged ignition of methane in the counterflow
Authors: Liu Wei , Law Chung K. , Lu Tianfeng 
Published: October 2009

AbstractThe counterflow ignition of methane was investigated, with particular interest in the role of radical versus thermal runaway. Simulation with different kinetic mechanisms showed that the ignition response is qualitatively sensitive to the kinetic mechanism adopted, either exhibiting or not exhibiting two ignition turning points in the S‐curve response. For the former situation, ignition could take place in a staged manner with either increasing temperature or decreasing strain rate of the counterflow, characterized by the first ignition event being radical induced with negligible thermal effect and the second ignition event requiring thermal feedback. Sensitivity analysis and a recently developed chemical explosive mode analysis were performed to identify the dominant reactions in the radical runaway stage, revealing the importance of branching pathways involving the HO2 radical. Counterflow experiments were also conducted, yielding useful information on the ignition response. The study identifies items of further research to sharpen the comprehensiveness and accuracy of the methane oxidation mechanism. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 764–776, 2009
Solvent and substituent effects on the reaction of 2‐ and 4‐chloro‐3,5‐dinitrobenzotrifluorides with substituted anilines
Authors: Asghar Basim H. M. , Fathalla Magda F. , Hamed Ezzat A. 
Published: October 2009

AbstractThe solvent effect on a nucleophilic substitution reaction of 2‐ and 4‐chloro‐3,5‐dinitrobenzotrifluoride with substituted anilines was studied in methanol, acetonitrile, and toluene at 25°C. This reaction is of second order, except 2‐chloro‐3,5‐dinitrobenzotrifluoride in toluene shows third order. The kA values are found to be dependent on the substituent in aniline and give good Hammett correlations. The obtained ρ values are −4.07 and −4.62, for the reaction of anilines with 2‐chloro‐3,5‐dinitrobenzotrifluoride in methanol and acetonitrile, respectively. The ρ values for the reaction of the anilines with 4‐chloro‐3,5‐dinitrobenzotrifluoride are −3.38, −4.11, and −4.34 in methanol, acetonitrile, and toluene, respectively. The reaction of the former compound with anilines in toluene shows a second order in aniline. The dependence of the reaction on the external base such as DABCO suggests a proton transfer controlling step. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 777–786, 2009