bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prescribed‐fire effects on rill and interrill runoff and erosion in a mountainous sagebrush landscape
Authors: Pierson Frederick B. , Moffet Corey A. , Williams C. Jason , Hardegree Stuart P. , Clark Patrick E. 
Published: January 2009

AbstractChanging fire regimes and prescribed‐fire use in invasive species management on rangelands require improved understanding of fire effects on runoff and erosion from steeply sloping sagebrush‐steppe. Small (0·5 m2) and large (32·5 m2) plot rainfall simulations (85 mm h–1, 1 h) and concentrated flow methodologies were employed immediately following burning and 1 and 2 years post‐fire to investigate infiltration, runoff and erosion from interrill (rainsplash, sheetwash) and rill (concentrated flow) processes on unburned and burned areas of a steeply sloped sagebrush site on coarse‐textured soils. Soil water repellency and vegetation were assessed to infer relationships in soil and vegetation factors that influence runoff and erosion. Runoff and erosion from rainfall simulations and concentrated flow experiments increased immediately following burning. Runoff returned to near pre‐burn levels and sediment yield was greatly reduced with ground cover recovery to 40 per cent 1 year post‐fire. Erosion remained above pre‐burn levels on large rainfall simulation and concentrated flow plots until ground cover reached 60 per cent two growing seasons post‐fire. The greatest impact of the fire was the threefold reduction of ground cover. Removal of vegetation and ground cover and the influence of pre‐existing strong soil‐water repellency increased the spatial continuity of overland flow, reduced runoff and sediment filtering effects of vegetation and ground cover, and facilitated increased velocity and transport capacity of overland flow. Small plot rainfall simulations suggest ground cover recovery to 40 per cent probably protected the site from low‐return‐interval storms, large plot rainfall and concentrated flow experiments indicate the site remained susceptible to elevated erosion rates during high‐intensity or long duration events until ground cover levels reached 60 per cent. The data demonstrate that the persistence of fire effects on steeply‐sloped, sandy sagebrush sites depends on the time period required for ground cover to recover to near 60 per cent and on the strength and persistence of ‘background’ or fire‐induced soil water repellency. Published in 2009 by John Wiley & Sons, Ltd.
Data aided symbol timing estimation in space–time coding systems with continuous phase modulation
Authors: Shen Wenli , Zhao Minjian , Qiu Peiliang 
Published: January 2009

AbstractSpace–time coding has been proposed recently in the MIMO wireless communication systems for improving the capacity and data rate without bandwidth expansion. Symbol timing synchronisation is an important issue in such systems. In this paper, a novel data aided symbol timing estimation algorithm was proposed for burst‐mode transmission systems of space–time trellis coding combined with continuous phase modulation (CPM) for Rayleigh fading channels. A training sequence is embedded before transmission of each packet. The receiver calculates the Digital Fourier Transformation (DFT) of the phase of the differential signals. The symbol timing offset can be estimated from the phase of the tone component of the DFT outputs. MATLAB simulation results show that the variance of the timing estimation error is very small. This algorithm can estimate the initial timing offset rapidly and accurately. Space–time coding has been proposed recently in the MIMO wireless communication systems for improving the capacity and data rate without bandwidth expansion. Symbol timing synchronisation is an important issue in such systems. In this paper, a novel data aided symbol timing estimation algorithm was proposed for burst‐mode transmission systems of space–time trellis coding combined with continuous phase modulation (CPM) for Rayleigh fading channels. A training sequence is embedded before transmission of each packet. The receiver calculates the Digital Fourier Transformation (DFT) of the phase of the differential signals. The symbol timing offset can be estimated from the phase of the tone component of the DFT outputs. MATLAB simulation results show that the variance of the timing estimation error is very small. This algorithm can estimate the initial timing offset rapidly and accurately. Copyright © 2009 John Wiley & Sons, Ltd.
Is reversal of large stock‐price declines caused by overreaction or information asymmetry: Evidence from stock and option markets
Authors: Choi Hyung‐Suk , Jayaraman Narayanan 
Published: January 2009

AbstractThe role of option markets is reexamined in the reversal process of stock prices following stock price declines of 10% or more. A matched pair of optionable and nonoptionable firms is randomly selected when their price declines by 10% or more on the same date. The authors examine the 1,443 and 1,018 matched pairs of New York Stock Exchange/American Stock Exchange (AMEX) and National Association of Securities Dealers Automated Quotations firms over the period from 1996 to 2004. It was found that the positive rebounds for nonoptionable firms are caused by an abnormal increase in bid–ask spread on and before the large price decline date. On the other hand, the bid–ask spreads for optionable firms decrease on and before the large price decline date. An abnormal increase in the open interest and volume in the option market on and before the large price decline date was also found. Overall, the results suggest that the stock‐price reversal neither is a result of overreaction nor can it be simply explained by the bid–ask bounce. © 2009 Wiley Periodicals, Inc. Jrl Fut Mark 29:348–376, 2009
Genotype‐based matching to correct for population stratification in large‐scale case‐control genetic association studies
Authors: Guan Weihua , Liang Liming , Boehnke Michael , Abecasis Gonçalo R. 
Published: January 2009

AbstractGenome‐wide association studies are helping to dissect the etiology of complex diseases. Although case‐control association tests are generally more powerful than family‐based association tests, population stratification can lead to spurious disease‐marker association or mask a true association. Several methods have been proposed to match cases and controls prior to genotyping, using family information or epidemiological data, or using genotype data for a modest number of genetic markers. Here, we describe a genetic similarity score matching (GSM) method for efficient matched analysis of cases and controls in a genome‐wide or large‐scale candidate gene association study. GSM comprises three steps: (1) calculating similarity scores for pairs of individuals using the genotype data; (2) matching sets of cases and controls based on the similarity scores so that matched cases and controls have similar genetic background; and (3) using conditional logistic regression to perform association tests. Through computer simulation we show that GSM correctly controls false‐positive rates and improves power to detect true disease predisposing variants. We compare GSM to genomic control using computer simulations, and find improved power using GSM. We suggest that initial matching of cases and controls prior to genotyping combined with careful re‐matching after genotyping is a method of choice for genome‐wide association studies.Genet. Epidemiol. 33:508–517, 2009. © 2009 Wiley‐Liss, Inc.
Peripheral myelin protein 22 is regulated post‐transcriptionally by miRNA‐29a
Authors: Verrier Jonathan D. , Lau Pierre , Hudson Lynn , Murashov Alexander K. , Renne Rolf , Notterpek Lucia 
Published: January 2009

AbstractPeripheral myelin protein 22 (PMP22) is a dose‐sensitive, disease‐associated protein primarily expressed in myelinating Schwann cells. Either reduction or overproduction of PMP22 can result in hereditary neuropathy, suggesting a requirement for correct protein expression for peripheral nerve biology. PMP22 is post‐transcriptionally regulated and the 3′untranslated region (3′UTR) of the gene exerts a negative effect on translation. MicroRNAs (miRNAs) are small regulatory molecules that function at a post‐transcriptional level by targeting the 3′UTR in a reverse complementary manner. We used cultured Schwann cells to demonstrate that alterations in the miRNA biogenesis pathway affect PMP22 levels, and endogenous PMP22 is subjected to miRNA regulation. GW‐body formation, the proposed cytoplasmic site for miRNA‐mediated repression, and Dicer expression, an RNase III family ribonuclease involved in miRNA biogenesis, are co‐regulated with the differentiation state of Schwann cells. Furthermore, the levels of Dicer inversely correlate with PMP22, while the inhibition of Dicer leads to elevated PMP22. Microarray analysis of actively proliferating and differentiated Schwann cells, in conjunction with bioinformatics programs, identified several candidate PMP22‐targeting miRNAs. Here we demonstrate that miR‐29a binds and inhibits PMP22 reporter expression through a specific miRNA seed binding region. Over‐expression of miR‐29a enhances the association of PMP22 RNA with Argonaute 2, a protein involved in miRNA function, and reduces the steady‐state levels of PMP22. In contrast, inhibition of endogenous miR‐29a relieves the miRNA‐mediated repression of PMP22. Correlation analyses of miR‐29 and PMP22 in sciatic nerves reveal an inverse relationship, both developmentally and in post‐crush injury. These results identify PMP22 as a target of miRNAs and suggest that myelin gene expression by Schwann cells is regulated by miRNAs. © 2009 Wiley‐Liss, Inc.
Ca2+‐ and thromboxane‐dependent distribution of MaxiK channels in cultured astrocytes: From microtubules to the plasma membrane
Authors: Ou J. W. , Kumar Y. , Alioua A. , Sailer C. , Stefani E. , Toro L. 
Published: January 2009

AbstractLarge‐conductance, voltage‐ and Ca2+‐activated K+ channels (MaxiK) are broadly expressed ion channels minimally assembled by four pore‐forming α‐subunits (MaxiKα) and typically observed as plasma membrane proteins in various cell types. In murine astrocyte primary cultures, we show that MaxiKα is predominantly confined to the microtubule network. Distinct microtubule distribution of MaxiKα was visualized by three independent labeling approaches: (1) MaxiKα‐specific antibodies, (2) expressed EGFP‐labeled MaxiKα, and (3) fluorophore‐conjugated iberiotoxin, a specific MaxiK pore‐blocker. This MaxiKα association with microtubules was further confirmed by in vitro His‐tag pulldown, co‐immunoprecipitation from brain lysates, and microtubule depolymerization experiments. Changes in intracellular Ca2+ elicited by general pharmacological agents, caffeine or thapsigargin, resulted in increased MaxiKα labeling at the plasma membrane. More notably, U46619, an analog of thromboxane A2 (TXA2), which triggers Ca2+‐release pathways and whose levels increase during cerebral hemorrhage/trauma, also elicits a similar increase in MaxiKα surface labeling. Whole‐cell patch clamp recordings of U46619‐stimulated cells develop a ∼3‐fold increase in current amplitude indicating that TXA2 stimulation results in the recruitment of additional, functional MaxiK channels to the surface membrane. While microtubules are largely absent in mature astrocytes, immunohistochemistry results in brain slices show that cortical astrocytes in the newborn mouse (P1) exhibit a robust expression of microtubules that significantly colocalize with MaxiKα. The results of this study provide the novel insight that suggests that Ca2+ released from intracellular stores may play a key role in regulating the traffic of intracellular, microtubule‐associated MaxiKα stores to the plasma membrane of developing murine astrocytes. © 2009 Wiley‐Liss, Inc.
Impact of pretransplant hyponatremia on outcome following liver transplantation #
Authors: Yun Byung Cheol , Kim Ray W. , Benson Joanne T. , Biggins Scott W. , Therneau Terry M. , Kremers Walter K. , Rosen Charles B. , Klintmalm Goran B. 
Published: January 2009

Abstract
Hyponatremia is associated with reduced survival in patients with cirrhosis awaiting orthotopic liver transplantation (OLT). However, data are sparse regarding the impact of hyponatremia on outcome following OLT. We investigated the effect of hyponatremia at the time of OLT on mortality and morbidity following the procedure. The study included 2,175 primary OLT recipients between 1990 and 2000. Serum sodium concentrations obtained immediately prior to OLT were correlated with subsequent survival using proportional hazards analysis. Morbidity associated with hyponatremia was assessed, including length of hospitalization, length of intensive care unit (ICU) admission, and occurrence of central pontine myelinolysis (CPM). Out of 2,175 subjects, 1,495 (68.7%) had normal serum sodium (>135 mEq/L) at OLT, whereas mild hyponatremia (125-134 mEq/L) was present in 615 (28.3%) and severe hyponatremia (<125 mEq/L) in 65 (3.0%). Serum sodium had no impact on survival up to 90 days after OLT (multivariate hazard ratio = 1.00, P = 0.99). Patients with severe hyponatremia tended to have a longer stay in the ICU (median = 4.5 days) and hospital (17.0 days) compared to normonatremic recipients (median ICU stay = 3.0 days, hospital stay = 14.0 days; P = 0.02 and 0.08, respectively). There were 10 subjects that developed CPM, with an overall incidence of 0.5%. Although infrequent, the incidence of CPM did correlate with serum sodium levels (P < 0.01). Conclusion: Pre-OLT serum sodium does not have a statistically significant impact on survival following OLT. The incidence of CPM correlates with hyponatremia, although its overall incidence is low. Incorporation of serum sodium in organ allocation may not adversely affect the overall post-OLT outcome. (Hepatology 2009;49:1610–1615.)
Fibrin accumulation plays a critical role in the sensitization to lipopolysaccharide-induced liver injury caused by ethanol in mice #
Authors: Beier Juliane I. , Luyendyk James P. , Guo Luping , von Montfort Claudia , Staunton Donald E. , Arteel Gavin E. 
Published: January 2009

AbstractThe early stages of alcohol-induced liver injury involve chronic inflammation. Whereas mechanisms by which this effect is mediated are not completely understood, it is hypothesized that enhanced sensitivity to circulating lipopolysaccharide (LPS) contributes to this process. It has recently been shown that ethanol induces activation of plasminogen activator inhibitor-1 (PAI-1). PAI-1 causes fibrin accumulation in liver by inhibiting degradation of fibrin (fibrinolysis). LPS also enhances fibrin accumulation by activating the coagulation cascade. It was therefore hypothesized that ethanol will synergistically increase fibrin accumulation caused by LPS, enhancing liver damage. Accordingly, the effect of ethanol pretreatment on LPS-induced liver injury and fibrin deposition was determined in mice. Ethanol enhanced liver damage caused by LPS, as determined by plasma parameters and histological indices of inflammation and damage. This effect was concomitant with a significant increase in PAI-1 expression. Extracellular fibrin accumulation caused by LPS was also robustly increased by ethanol preexposure. Coadministration of the thrombin inhibitor hirudin or the MEK (mitogen-activated protein kinase) inhibitor U0126 significantly attenuated the enhanced liver damage caused by ethanol preexposure; this protection correlated with a significant blunting of the induction of PAI-1 caused by ethanol/LPS. Furthermore, thrombin/MEK inhibition prevented the synergistic effect of ethanol on the extracellular accumulation of fibrin caused by LPS. Similar protective effects on fibrin accumulation were observed in tumor necrosis factor receptor 1 (TNFR-1)−/−mice or in wild-type injected with PAI-1-inactivating antibody.Conclusion:These results suggest that enhanced LPS-induced liver injury caused by ethanol is mediated, at least in part, by fibrin accumulation in livers, mediated by an inhibition of fibrinolysis by PAI-1. These results also support the hypothesis that fibrin accumulation may play a critical role in the development of early alcohol-induced liver injury. (Hepatology 2009.)
Hepatitis C virus core protein triggers hepatic angiogenesis by a mechanism including multiple pathways #
Authors: Hassan Mohamed , Selimovic Denis , Ghozlan Hanan , Abdel-kader Ola 
Published: January 2009

Abstract
Chronic hepatitis C virus (HCV) infection is associated with the production of serum cytokines, including transforming growth factor (TGF)-β2. Despite the occurrence of hepatic angiogenesis in liver conditions, the role of HCV proteins in this context is currently unknown. We demonstrated that the development of hepatic neoangiogenesis in patients infected with HCV is associated with the expression of TGF-β2 and vascular endothelial growth factor (VEGF) and with activation of endothelial cells, as evidenced by CD34 expression. The analysis of liver biopsies of HCV-positive and HCV-negative patients using immunostaining showed significant elevation of TGF-β2, VEGF, and CD34 expression in patients who were HCV-positive. Using an HCV established culture system, we confirmed further the production of both TGF-β2 and VEGF proteins, in the hepatoma cell lines HepG2 and Huh7 by transfection with full-length HCV RNA (JFH1) or by the regulated expression of core. In addition, regulated expression of core protein in HepG2 or Huh7 cells was found to induce expression and activation of the transcription factor E2F1 and apoptosis signal-regulating kinase 1 (ASK1), activation of c-jun-N-terminal kinase (JNK) and p38, and extracellular-regulated kinase (ERK), and transcription factors activator protein 1 (AP-1), activating transcription factor 2 (ATF-2), cyclic adenosine monophosphate response element binding (CREB), E2F1, hypoxia inducing factor 1 alpha (HIF-1α), and specificity protein 1. Furthermore, data obtained from inhibitor experiments revealed the importance of E2F1 and ASK1 in the modulation of core-induced activation of JNK and p38 pathways and suggested an essential role for JNK, p38, and ERK pathways in the regulation of core-induced production of TGF-β2 and VEGF proteins. Thus, our data provide insight into the molecular mechanisms whereby core protein mediates the development of hepatic angiogenesis in patients with chronic HCV infection. (Hepatology 2009.)
Motor acquisition rate in Brazilian infants
Authors: Lopes Virlaine Bardella , de Lima Carolina Daniel , Tudella Eloisa 
Published: January 2009

AbstractThis study used the Alberta Infant Motor Scale (AIMS) with the aim of characterizing motor acquisition rate in 70 healthy 0–6‐month‐old Brazilian infants, as well as comparing both emergence (initial age) and establishment (final age) of each skill between the study sample and the AIMS normative data. New motor skills were continuously acquired from 0 to 6 months of age by the Brazilian infants, but their acquisition rate was non‐linear. When compared to the AIMS sample, Brazilian infants achieved lower percentiles, and their initial age to acquire skills requiring greater antigravity demand was higher. In contrast, Brazilian infants stopped exhibiting primitive patterns earlier, and their final age to acquire antigravity skills was lower. These differences in motor development are suggested to be a consequence of different parental practices and not necessarily indicate motor delay. Thus, the AIMS normative values should be adapted to cultural particularities so as to avoid that infants are misclassified as at risk for motor delay. Furthermore, an adequate assessment of motor development should consider not only the age at which a skill is emerged, but also the age at which such a skill is established in the infant's motor repertoire. Copyright © 2009 John Wiley & Sons, Ltd.
What do infants see in faces? ERP evidence of different roles of eyes and mouth for face perception in 9‐month‐old infants
Authors: Key Alexandra P. F. , Stone Wendy , Williams Susan M. 
Published: January 2009

AbstractThe study examined whether face‐specific perceptual brain mechanisms in 9‐month‐old infants are differentially sensitive to changes in individual facial features (eyes versus mouth) and whether sensitivity to such changes is related to infants' social and communicative skills. Infants viewed photographs of a smiling unfamiliar female face. On 30% of the trials, either the eyes or the mouth of that face were replaced by corresponding parts from a different female. Visual event‐related potentials were recorded to examine face‐sensitive brain responses. Results revealed that increased competence in expressive communication and interpersonal relationships was associated with a more mature response to faces, as reflected in a larger occipito‐temporal N290 with shorter latency. Both eye‐ and mouth changes were detected, though infants derived different information from these features. Eye changes had a greater impact on the face perception mechanisms and were not correlated with social or communication development, whereas mouth changes had a minimal impact on face processing but were associated with levels of language and communication understanding. Copyright © 2009 John Wiley & Sons, Ltd.
Evaluation of the osteogenic potential and vascularization of 3D poly(3)hydroxybutyrate scaffolds subcutaneously implanted in nude rats
Authors: Rentsch Claudia , Rentsch Barbe , Breier Annette , Hofmann Andre , Manthey Suzanne , Scharnweber Dieter , Biewener Achim , Zwipp Hans 
Published: January 2009

AbstractThe aim of this study was to evaluate the osteogenic potential and the vascularization of embroidered, tissue engineered, and cell‐seeded 3D poly(3)hydroxybutyrate (PHB) scaffolds in nude rats. Collagen I (coll I)‐ and collagen I/chondroitin sulfate (coll I/CS)‐coated PHB scaffolds were seeded with human mesenchymal stem cells (hMSCs). Proliferation and differentiation were characterized by different biochemical assays in vitro. For animal experiments, the cells were cultivated on coll I‐ or coll I/CS‐coated scaffolds and either expanded or osteogenically differentiated. Scaffolds were piled up to create a 3D scaffold pad and implanted subcutaneously into nude rats. In vitro hMSC showed proliferation and differentiation on PHB scaffolds. Alkaline phosphatase (ALP) and calcium increased in the differentiation medium and in the presence of coll I/CS. In vivo blood vessels were found in the scaffold‐stack. Histological/immunohistological analyses of explanted scaffolds showed osteogenic markers such as osteopontin, osteonectin, and coll I around the PHB fibers. Coll I/CS‐coated scaffolds with expanded hMSC showed higher values of ALP and calcium than the other combinations. Embroidered PHB scaffolds, coated with extracellular matrix components, provided an adequate environment and, therefore, a template for hMSC which could be differentiated in osteogenic direction. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010