bluuebunny/crossref_metadata_2025_split huggingface dataset:
The filtering capacity of a tropical riverine wetland: II. Sediment and nutrient balances
Authors: McJannet David , Wallace Jim , Keen Rex , Hawdon Aaron , Kemei Joseph 
Published: April 2011

AbstractThe ability of wetlands to improve the quality of water has long been recognized and has led to the proliferation of wetlands as a means to treat diffuse and point source pollutants from a range of land uses. However, much of the existing research has been undertaken in temperate climates with a paucity of information on the effectiveness of wetlands, particularly natural wetlands, in tropical regions. This paper contributes to addressing this issue by presenting a comprehensive measurement based assessment of the potential for a naturally occurring tropical riverine wetland to improve the quality of the water entering it. We found small net imports and exports of sediment to/from the wetland in individual years, but over the longer term this kind of wetland is neither a sink nor source of sediment. In contrast, phosphorus was continually removed by the wetland with an overall net reduction of 14%. However, it should be noted that there is no ‘permanent’ gaseous loss mechanism for phosphorus, and its removal from the water column is equal to its accumulation in the wetland soil. We found very little removal of nitrogen by this type of wetland from several analyses including: (i) Surface and groundwater fluxes, (ii) Estimation of water column and soil denitrification rates, (iii) Wetland residence times, and (iv) Hydraulic loading. We also found no clear evidence for transformation of nitrogen to more or less bio‐available forms. Hence, while the benefits of using wetlands to improve water quality in controlled environments have been demonstrated in the literature, these benefits may not always be directly translated to unmanaged natural wetland systems when there is strong seasonality in flows and short residence time during the periods of maximum sediment and nutrient load. Copyright © 2011 John Wiley & Sons, Ltd.
Sp1 is upregulated in human glioma, promotes MMP‐2‐mediated cell invasion and predicts poor clinical outcome
Authors: Guan Hongyu , Cai Junchao , Zhang Nu , Wu Jueheng , Yuan Jie , Li Jun , Li Mengfeng 
Published: April 2011

AbstractSp1, the first identified transcription factor, has been reported to be associated with the development and progression of various human cancer types. However, the clinical significance and biological role of Sp1 in glioma are less well understood. In this study, we found that the expression of Sp1 was markedly elevated in glioma cell lines and tissues. Immunohistochemistry analysis revealed that the vast majority of 222 paraffin‐embedded archival glioma specimens tested displayed positive Sp1 expression, and 58.6% exhibited high‐level Sp1 expression. Statistical analysis suggested that the high Sp1 expression was correlated strongly with the WHO grading (p < 0.001) and survival status (p < 0.001) of glioma patients. Patients with lower Sp1 expression had better overall survival than those with higher Sp1 expression. Multivariate analysis suggested that Sp1 expression might be an independent prognostic indicator of the survival of patients with glioma. Furthermore, overexpression of Sp1 in glioma cells was found to increase their invasiveness, and in contrast, silencing Sp1 by siRNA caused an inhibition of cell invasion. Moreover, we demonstrated that the up‐regulation of Sp1 could increase activity and expression of MMP‐2. Collectively, our data suggest that Sp1 might represent a valuable prognostic marker for glioma and is involved in modulation of tumor invasion.
Trends in incidence of anal cancer and high‐grade anal intraepithelial neoplasia in Denmark, 1978–2008
Authors: Nielsen Ann , Munk Christian , Kjaer Susanne K. 
Published: April 2011

AbstractThe aim of the study was to determine the incidences of anal cancer and high‐grade anal intraepithelial neoplasia (AIN2/3) over time in Danish women and men. Describing the burden of anal cancer and AIN may be valuable in future evaluations of the human papillomavirus (HPV) vaccine. We included all anal cancers in the Danish Cancer Register in the period 1978–2008 and all cases of AIN2/3 in the Danish Registry of Pathology. Overall and age‐, period‐ and histology‐specific incidence rates were estimated. During the 30‐year period, 2,187 anal cancers were identified, two thirds of which were in women. Between 1978–1982 and 2003–2008, the age‐standardized incidence rate of anal cancer increased from 0.68 to 1.48 per 100,000 person‐years in women and from 0.45 to 0.80 per 100,000 person‐years in men. Although there is no systematic screening for AIN in Denmark, we nevertheless identified 608 cases of AIN2/3 during the study period. The average annual percentage change of 5% between 1998 and 2008 represents a steep increase in the incidence of AIN in both genders. Furthermore, the incidence rate of HPV‐associated anal cancers increased significantly, whereas that of non‐HPV‐associated histological types levelled out or even declined during the 30 years of observation. In women, the increase in HPV‐associated cancers was more pronounced among those under 60 years of age. Our findings indicate that vaccines against HPV might play an important role in the prevention of anal cancer and its precursor lesions.
Optimization of parameters for molecular dynamics simulation using smooth particle‐mesh Ewald in GROMACS 4.5
Authors: Abraham Mark J. , Gready Jill E. 
Published: April 2011

AbstractBased on our critique of requirements for performing an efficient molecular dynamics simulation with the particle‐mesh Ewald (PME) implementation in GROMACS 4.5, we present a computational tool to enable the discovery of parameters that produce a given accuracy in the PME approximation of the full electrostatics. Calculations on two parallel computers with different processor and communication structures showed that a given accuracy can be attained over a range of parameter space, and that the attributes of the hardware and simulation system control which parameter sets are optimal. This information can be used to find the fastest available PME parameter sets that achieve a given accuracy. We hope that this tool will stimulate future work to assess the impact of the quality of the PME approximation on simulation outcomes, particularly with regard to the trade‐off between cost and scientific reliability in biomolecular applications. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
How reliable are GIAO calculations of 1H and 13C NMR chemical shifts? A statistical analysis and empirical corrections at DFT (PBE/3z) level
Authors: Pankratyev Evgeniy Yu. , Tulyabaev Artur R. , Khalilov Leonard M. 
Published: April 2011

AbstractReliability of calculated 1H and 13C NMR chemical shifts for various classes of organic compounds obtained with gauge‐invariant atomic orbital (GIAO) approach has been studied at the PBE/3ζ level (as implemented in PRIRODA code) using linear regression analysis with experimental data. Empirical corrections for the calculated chemical shifts δH,calc = δPBE/3ζ − 0.08 ppm (RMS 0.18 ppm, MAD 0.66 ppm) and δC,calc = δPBE/3ζ − 6.35 ppm (RMS 3.09 ppm, MAD 9.42 ppm) have been developed using the sets of 263 and 308 experimental values for 1H and 13C chemical shifts, respectively. The confidence intervals of NMR chemical shifts at 95% confidence probability are δH,calc ± 0.35 ppm for 1H and δC,calc ± 6.05 ppm for 13C. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Exchange coupling constants using density functional theory: Long‐range corrected functionals
Authors: Ruiz Eliseo 
Published: April 2011

AbstractThe presence of the self‐interaction error in common exchange correlation functionals is one of the main drawbacks of calculations using methods based on Density Functional Theory. The recently developed asymptotically corrected functionals are an alternative way to solve the erroneous asymptotic behavior that may be at the origin of this error. Some of these functionals have been tested in the calculation of the exchange coupling constants of a number of transition metal dinuclear complexes. Correction of the self‐interaction error is especially important for calculations of this kind. This error leads to the inclusion of some static correlation terms that overestimate the J values. This study shows that some of the long‐range corrected functionals tested give promising results. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Metastases to the breast from extramammary malignancies—sonographic features
Authors: Lee Ji Hye , Kim Sung Hun , Kang Bong Joo , Cha Eun Suk , Kim Hyun Suk , Choi Jae Jeong 
Published: April 2011

AbstractPurpose.To evaluate the clinical and sonographic (US) features of metastatic tumors from extramammary malignancies to the breast.Methods.This study included 23 patients with pathologically proven metastases in the breast. Two radiologists retrospectively analyzed the images from US (n = 23), mammography (n = 11), and MRI (n = 5) examinations according to BIRADS.Results.Patients presented with a palpable mass or diffuse breast swelling (21/23) or were asymptomatic (2/23). Eighteen patients had solitary or multiple breast masses on US. The common US finding was an ovoid hypoechoic mass with a noncircumscribed margin. The final assessment categories were BIRADS 3 (probably benign finding) in 6 cases (25%) and BIRADS 4 (suspicious abnormality) in 18 cases (75%). In five patients, US displayed a diffuse infiltrative pattern without a focal lesion, which was categorized as BIRADS 4.Conclusions.Metastatic tumors in the breast have a wide range of sonographic appearances, with some resembling benign lesions. Any newly developed mass in a patient with a known history of extramammary malignancy, even with a probably benign US appearance, should undergo biopsy for pathologic confirmation. © 2011 Wiley Periodicals, Inc. J Clin Ultrasound, 2011
Vascular endothelial growth factor in cerebral ischemia
Authors: Ma Yihui , Qu Yan , Fei Zhou 
Published: April 2011

AbstractVascular endothelial growth factor (VEGF) is involved in many central nervous system disorders, including stroke, and confers neuroprotection in cerebral ischemia. In this Mini‐Review, we examine in detail the in vitro and in vivo evidence for the role of VEGF in cerebral ischemia. VEGF is a therapeutic mediator for cerebral ischemia because of its angiogenic and neuroprotective effects. However, several studies indicate that the delivery route and the timing of VEGF delivery seem to determine the outcome of VEGF therapy after an ischemic insult. In the acute stage of cerebral ischemia, the effect of VEGF is considered controversial. Therefore, further work is necessary to identify a suitable therapeutic regime prior to phase II/III clinical trials. In addition, recent studies indicate that VEGF enhances neurogenesis after ischemia. Therefore, further investigation is necessary to clarify the exact role of VEGF in neurogenesis. © 2011 Wiley‐Liss, Inc.
Getting organizational improvement off the ground: Using the Cube One framework to learn from the turnaround at Continental Airlines
Authors: Kopelman Richard E. , Chiou Andy Y. 
Published: April 2011

AbstractMuch has been written about the remarkable turnaround at Continental Airlines under Gordon Bethune and Greg Brenneman during the 1990s. But much can still be learned from the experience. This article reviews the general components of the turnaround plan at Continental Airlines; briefly describes the Cube One framework, which makes it possible to interpret and assess an organization's functioning by examining its productivity‐, customer‐, and employee‐directed practices; describes management practices implemented at Continental; and examines evidence pertinent to their effectiveness, comparing results during the five‐year period before Bethune and his team arrived (1990–1994) with the five‐year period afterward (1995–1999). It concludes with a look at Continental's practices in the early twenty‐first century. © 2011 Wiley Periodicals, Inc.
An analysis of corporate social responsibility in the Greek telecommunications sector
Authors: Giannarakis Grigoris , Sariannidis Nikolaos , Litinas Nikolaos 
Published: April 2011

AbstractIn assessing the performance of national and multinational businesses, attention focuses not only on financial performance, but also on such issues as social responsibility, environmental impact, and employment practices. There is a range of guidance and reporting mechanisms that allows firms to assess and communicate their performance in the area of corporate social responsibility (CSR). This study focuses on two such mechanisms, the Global Reporting Initiative (GRI) and the Deloitte Reporting Sustainability Scorecard (DRSS), and examines their use in four Greek telecommunications businesses. The findings reveal gaps in reporting practices in this field and highlight the differences between the two reporting systems and their usefulness for nonfinancial reporting. © 2011 Wiley Periodicals, Inc.
Estrogen reduces cellular aging in human mesenchymal stem cells and chondrocytes
Authors: Breu Anita , Sprinzing Benedikt , Merkl Katharina , Bechmann Volker , Kujat Richard , Jenei‐Lanzl Zsuzsa , Prantl Lukas , Angele Peter 
Published: April 2011

AbstractChondrocyte aging is associated with cartilage degeneration and senescence impairs the regenerative potential of mesenchymal stem cells (MSCs). Estrogen exerts profound effects on human physiology including articular cartilage and MSCs. The present study should analyze the effects of pre‐ and postmenopausal estrogen concentrations on chondrogenic cells. Physiologic premenopausal concentrations of 17β‐estradiol (E2) significantly decelerated telomere attrition in MSCs and chondrocytes while postmenopausal E2concentration had no significant effects. The estrogen agonist–antagonist tamoxifen did not affect telomere biology, but inhibited the E2‐stimulated reduction in telomere shortening. E2and tamoxifen did not influence cell proliferation, cell morphology, and β‐galactosidase staining in chondrogenic cells. E2treatment did not affect the telomere‐associated proteins TRF1 and TRF2. E2had no regulatory effects on the expression rates of the cell cycle regulator p21 and the DNA repair proteins SIRT1 and XRCC5. In spite of reducing telomere shortening in aging MSCs and chondrocytes, estrogen is not able to prevent somatic cells from replicative exhaustion and from finally entering senescence. The fade of telomere shortening under pre‐ to postmenopausal estrogen concentrations suggests, at least in part, a senescence‐dependent cause for the onset of osteoarthritis in women after menopause. © 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29: 1563–1571, 2011
Disulfide Core Cross‐Linked PEGylated Polypeptide Nanogel Prepared by a One‐Step Ring Opening Copolymerization of N‐Carboxyanhydrides for Drug Delivery
Authors: Xing Tao , Lai Bin , Ye Xiaodong , Yan Lifeng 
Published: April 2011

AbstractA novel disulfide core cross‐linked PEGylated polypeptide nanogel has been synthesized by a one‐step ring opening copolymerization of γ‐benzyl L‐glutamate N‐carboxyanhydride and L‐cystine N‐carboxyanhydride using an amino group‐terminated poly(ethylene glycol) methyl ether as initiator. Characterization of products confirms the formation of a core cross‐linked PEGylated nanogel with disulfide linkages with a size of about 250 nm, and these studies also confirm that this nanogel can easily be broken by glutathione. Cell viability experiments show the good biocompatibility of the as‐prepared polymer. Studies relating to loading and controlled release of indomethacin under reduction‐sensitive conditions reveal that the nanogel is a good candidate for drug delivery systems.
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Fast Deswelling Kinetics of Nanostructured Poly(N‐Isopropylacrylamide) Photopolymerized in a Lyotropic Liquid Crystal Template
Authors: Forney Bradley S. , Allan Guymon C. 
Published: April 2011

AbstractThe thermal‐response and mechanical properties of poly(N‐isopropylacrylamide) (PNIPAm) are improved by controlling the polymer nanostructure through photopolymerization in a bicontinuous cubic lyotropic liquid crystal (LLC) template. The bicontinuous cubic nanostructure increases the rate and amount of water expelled from PNIPAm for heating above the lower critical solution temperature (LCST) relative to an isotropic PNIPAm hydrogel while maintaining the mechanical integrity of the polymer. These results could allow development of PNIPAm hydrogels with proper water uptake, deswelling kinetics, volume transition, and mechanical properties required for successful performance in a growing number of advanced biological and industrial applications. magnified image
Supramolecular Architectures Self‐assembled from Asymmetrical Hetero Cyclopeptides
Authors: Qin Si‐Yong , Xu Xiao‐Ding , Chen Chang‐Sheng , Chen Jing‐Xiao , Li Ze‐Yong , Zhuo Ren‐Xi , Zhang Xian‐Zheng 
Published: April 2011

AbstractIn this study, two asymmetrical cyclopeptides (CP1 and CP2) were designed and synthesized. The self‐assembly behaviors of the asymmetrical cyclopeptides at varying pHs were investigated in terms of transmission electron microscopy (TEM), circular dichroism (CD), and Fourier transform infrared (FT‐IR) spectroscopy. It was found that the self‐assembly of CP1 resulted in the formation of nanofibers with α‐helix conformation, while CP2 self‐assembled into well‐ordered nanorods with anti‐parallel β‐sheet conformation. The strategy demonstrated here presents great potential for preparation of well‐defined nanostructures via rationally designing the molecular structures of cyclopeptides. magnified image
Adapting Visual‐Analytical Tools for the Exploration of Structural and Dynamical Features of Polymer Conformations
Authors: Thakur Sidharth , Pasquinelli Melissa A. 
Published: April 2011

AbstractConformational analysis of macromolecular structures reveals interesting higher‐order spatial arrangements. Analyzing these features as a function of time provides insights into the dynamical behavior of these systems and the identification of relevant subdomains. We present some visual‐analytic methods that we devised to explore the spatial‐temporal properties from molecular dynamics simulation data. These methods automatically detect common features and connect them to properties of interest. These methods yield physical insights that are not easily obtainable with existing methods for particle simulation data, as illustrated for polyacetylene interacting with a carbon nanotube. magnified image
Botulinum toxin injections reduce associative plasticity in patients with primary dystonia
Authors: Kojovic Maja , Caronni Antonio , Bologna Matteo , Rothwell John C. , Bhatia Kailash P. , Edwards Mark J. 
Published: April 2011

AbstractBotulinum toxin injections ameliorate dystonic symptoms by blocking the neuromuscular junction and weakening dystonic contractions. We asked if botulinum toxin injections in dystonia patients might also affect the integrity of sensorimotor cortical plasticity, one of the key pathophysiological features of dystonia. We applied a paired associative stimulation protocol, known to induce long‐term potentiation–like changes in the primary motor cortex hand area to 12 patients with cervical dystonia before and 1 and 3 months after botulinum toxin injections to the neck muscles. Primary motor cortex excitability was probed by measuring transcranial magnetic stimulation‐evoked motor evoked potentials before and after paired associative stimulation. We also measured the input–output curve, short‐interval intracortical inhibition, intracortical facilitation, short afferent inhibition, and long afferent inhibition in hand muscles and the clinical severity of dystonia. Before botulinum toxin injections, paired associative stimulation significantly facilitated motor evoked potentials in hand muscles. One month after injections, this effect was abolished, with partial recovery after 3 months. There were significant positive correlations between the facilitation produced by paired associative stimulation and (1) the time elapsed since botulinum toxin injections and (2) the clinical dystonia score. One effect of botulinum toxin injection treatment is to modulate afferent input from the neck. We propose that subsequent reorganization of the motor cortex representation of hand muscles may explain the effect of botulinum toxin on motor cortical plasticity. © The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.
The bias/variance trade‐off when estimating the MR signal magnitude from the complex average of repeated measurements
Authors: Tisdall M. Dylan , Lockhart Richard A. , Atkins M. Stella 
Published: April 2011

AbstractThe signal‐dependent bias of MR images has been considered a hindrance to visual interpretation almost since the beginning of clinical MRI. Over time, a variety of procedures have been suggested to produce less‐biased images from the complex average of repeated measurements. In this work, we re‐evaluate these approaches using first a survey of previous estimators in the MRI literature, then a survey of the methods statisticians employ for our specific problem. Our conclusions are substantially different from much of the previous work: first, removing bias completely is impossible if we demand the estimator have bounded variance; second, reducing bias may not be beneficial to image quality. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
A mathematical analysis of the R‐MAT random graph generator
Authors: Groër Chris , Sullivan Blair D. , Poole Steve 
Published: April 2011

AbstractThe R‐MAT graph generator introduced by Chakrabarti et al (Int Conf Data Mining, 2004) offers a simple, fast method for generating very large directed graphs. These properties have made it a popular choice as a method of generating graphs for objects of study in a variety of disciplines, from social network analysis to high performance computing. We analyze the graphs generated by R‐MAT and model the generator in terms of occupancy problems to prove results about the degree distributions of these graphs. We prove that the limiting degree distributions can be expressed as a mixture of normal distributions with means and variances that can be easily calculated from the R‐MAT parameters. Additionally, this article offers an efficient computational technique for computing the exact degree distribution and concise expressions for a number of properties of R‐MAT graphs. ©2011 Wiley Periodicals, Inc.*. NETWORKS, 2011
An adaptive finite point method for the shallow water equations
Authors: Ortega Enrique , Oñate Eugenio , Idelsohn Sergio , Buachart Chinapat 
Published: April 2011

AbstractAn adaptive Finite Point Method (FPM) for solving shallow water problems is presented. The numerical methodology we propose, which is based on weighted‐least squares approximations on clouds of points, adopts an upwind‐biased discretization for dealing with the convective terms in the governing equations. The viscous and source terms are discretized in a pointwise manner and the semi‐discrete equations are integrated explicitly in time by means of a multi‐stage scheme. Moreover, with the aim of exploiting meshless capabilities, an adaptive h‐refinement technique is coupled to the described flow solver. The success of this approach in solving typical shallow water flows is illustrated by means of several numerical examples and special emphasis is placed on the adaptive technique performance. This has been assessed by carrying out a numerical simulation of the 26th December 2004 Indian Ocean tsunami with highly encouraging results. Overall, the adaptive FPM is presented as an accurate enough, cost‐effective tool for solving practical shallow water problems. Copyright © 2011 John Wiley & Sons, Ltd.