bluuebunny/crossref_metadata_2025_split huggingface dataset:
Importance of groundwater and macrophytes for the nutrient balance at oligotrophic Lake Hampen, Denmark
Authors: Oliveira Ommen Daniela A. , Kidmose Jacob , Karan Sachin , Flindt Mogens R. , Engesgaard Peter , Nilsson Bertel , Andersen Frede Ø. 
Published: March 2011

ABSTRACTAn ecohydrological study was carried out at an oligotrophic seepage lake, Lake Hampen, Denmark, to determine the seepage in and out of the lake and determine the mass budgets for nutrients. The lake is primarily surrounded by forest, although there are agricultural fields bordering a small portion of the lake perimeter. The water and mass balances indicate that there is a groundwater input of 1643 × 103 m3 year−1 into the lake (∼70% of total input) and a groundwater output of 1997 × 103 m3 year−1. The groundwater input carries with it 2253 kg N year−1 (∼67% of total input) and 40 kg P year−1 (∼85% of total input). The majority of the nitrogen is leached from the agricultural fields bordering the lake. Concentrations as high as 1750 µM nitrate were measured in the rhizosphere of the littoral zone at this location. It is estimated that the macrophytes are able to take up 1695 kg N year−1 (∼50% of the input). The phosphorus uptake by plants was 310% of the input, indicating that plants are highly dependent on accumulated and remineralized phosphorus in the lake. The nutrients lost through recharge was much lower than input through groundwater discharge entailing a high retention of nutrients in the lake (92–96%). A significant part of the retained nitrogen may be lost through denitrification. Although the plant uptake may have slowed the eutrophication of the lake, the excess nutrients may over time give rise to eutrophication and a shift towards pelagic production. Copyright © 2011 John Wiley & Sons, Ltd.
Nanoband electrode for high‐performance in‐channel amperometric detection in dual‐channel microchip capillary electrophoresis
Authors: Chen Chuanpin , Teng Wei , Hahn Jong Hoon 
Published: March 2011

AbstractA nanoband electrode detector integrated with a dual‐channel polydimethylsiloxane microchip is proposed for in‐channel amperometric detection in microchip capillary electrophoresis. Gold nanoband electrodes, which were fabricated on SU‐8 substrates with a 100‐nm‐width gold layer, were introduced into the dual‐channel microchip to be an electrochemical detector. Due to the nano‐sized width of the detector, the noise of the amperometric detection was significantly reduced, and a high separation resolution was achieved for monitoring the analytes. The detection sensitivity of the system was improved by high signal‐to‐noise ratio, and a low detection limit on microchip was obtained for p‐aminophenol (2.09 nM). Because of the high resolution in measuring half‐peak width, the plate number that is used to evaluate the separation efficiency was 1.5‐fold higher than that using 50‐μm‐width electrochemical detector. The effect of sample injection time and data acquisition time on separation efficiency was investigated, and an attractive separation efficiency was achieved with a plate number up to 17 500.
Numerical simulation of laminar flow past a circular cylinder with slip conditions
Authors: Seo Il Won , Song Chang Geun 
Published: March 2011

SUMMARYThe no‐slip condition is an assumption that cannot be derived from first principles and a growing number of literatures replace the no‐slip condition with partial‐slip condition, or Navier‐slip condition. In this study, the influence of partial‐slip boundary conditions on the laminar flow properties past a circular cylinder was examined. Shallow‐water equations are solved by using the finite element method accommodating SU/PG scheme. Four Reynolds numbers (20, 40, 80, and 100) and six slip lengths were considered in the numerical simulation to investigate the effects of slip length and Reynolds number on characteristic parameters such as wall vorticity, drag coefficient, separation angle, wake length, velocity distributions on and behind the cylinder, lift coefficient, and Strouhal number. The simulation results revealed that as the slip length increases, the drag coefficient decreases since the frictional component of drag is reduced, and the shear layer developed along the cylinder surface tends to push the separation point away toward the rear stagnation point so that it has larger separation angle than that of the no‐slip condition. The length of the wake bubble zone was shortened by the combined effects of the reduced wall vorticity and wall shear stress which caused a shift of the reattachment point closer to the cylinder. The frequency of the asymmetrical vortex formation with partial slip velocity was increased due to the intrinsic inertial effect of the Navier‐slip condition. Copyright © 2011 John Wiley & Sons, Ltd.
Regional brain volume reductions relate to facial dysmorphology and neurocognitive function in fetal alcohol spectrum disorders
Authors: Roussotte Florence F. , Sulik Kathleen K. , Mattson Sarah N. , Riley Edward P. , Jones Kenneth L. , Adnams Colleen M. , May Philip A. , O'Connor Mary J. , Narr Katherine L. , Sowell Elizabeth R. 
Published: March 2011

AbstractIndividuals with heavy prenatal alcohol exposure can experience significant deficits in cognitive and psychosocial functioning and alterations in brain structure that persist into adulthood. In this report, data from 99 participants collected across three sites (Los Angeles and San Diego, California, and Cape Town, South Africa) were analyzed to examine relationships between brain structure, neurocognitive function, facial morphology, and maternal reports of quantities of alcohol consumption during the first trimester. Across study sites, we found highly significant volume reductions in the FASD group for all of the brain regions evaluated. After correcting for scan location, age, and total brain volume, these differences remained significant in some regions of the basal ganglia and diencephalon. In alcohol‐exposed subjects, we found that smaller palpebral fissures were significantly associated with reduced volumes in the ventral diencephalon bilaterally, that greater dysmorphology of the philtrum predicted smaller volumes in basal ganglia and diencephalic structures, and that lower IQ scores were associated with both smaller basal ganglia volumes and greater facial dysmorphology. In subjects from South Africa, we found a significant negative correlation between intracranial volume and total number of drinks per week in the first trimester. These results corroborate previous reports that prenatal alcohol exposure is particularly toxic to basal ganglia and diencephalic structures. We extend previous findings by illustrating relationships between specific measures of facial dysmorphology and the volumes of particular subcortical structures, and for the first time show that continuous measures of maternal alcohol consumption during the first trimester relates to overall brain volume reduction. Hum Brain Mapp, 2012. © 2011 Wiley Periodicals, Inc.
Papillary thyroid carcinoma in black thyroids
Authors: Kandil Emad , Khalek Mohamed Abdel , Ibrahim Wael G. , Alabbas Haytham , Yau C. Lillian , Friedlander Paul , Crawford Byron , Jaffe Bernard M. 
Published: March 2011

AbstractBackgroundBlack thyroid is a rare condition. It has been considered to be pathognomonic of chronic minocycline ingestion for more than 30 years, although it can also occur in patients with hemochromatosis, ochronosis, mucoviscidosis, and hemorrhage. A possible association of black thyroid with thyroid cancer has been considered, but no direct causal relationship has been established. Hence, the purpose of this article was to identify the malignant potential of such glands.MethodsA retrospective medical chart review was performed on 433 patients who underwent thyroid surgery at Tulane University Medical Center from 2001 to 2008. Patients were grouped based on pathology: (1) benign, (2) papillary carcinoma, and (3) non‐papillary thyroid carcinoma.ResultsAt surgery, 63 patients (15%) with black thyroid gland were found to have thyroid nodules. Among these nodules, 22 (35%) were benign, 21 (33%) contained papillary thyroid cancer, and 20 (32%) had a non‐papillary thyroid malignancy. Nodules in black thyroids were associated with higher risk of malignancy than nodules in non‐black thyroids (p = .0001). Further analysis of the papillary thyroid carcinoma group showed no statistical difference in regard to tumor size or evidence of multifocality of disease.ConclusionThe finding of a black thyroid gland is unusual and disconcerting. To our knowledge, this is the first study aimed at documenting the malignant potential of black thyroid glands. This report documents that the risk of malignancy is higher in black thyroid compared to non‐black thyroid glands. Furthermore, among those with papillary thyroid cancer, the presence of the pigment did not correlate with malignancy, multifocality, or tumor size. © 2011 Wiley Periodicals, Inc. Head Neck, 2011
Realized GARCH: a joint model for returns and realized measures of volatility
Authors: Hansen Peter Reinhard , Huang Zhuo , Shek Howard Howan 
Published: March 2011

SUMMARYWe introduce a new framework, Realized GARCH, for the joint modeling of returns and realized measures of volatility. A key feature is a measurement equation that relates the realized measure to the conditional variance of returns. The measurement equation facilitates a simple modeling of the dependence between returns and future volatility. Realized GARCH models with a linear or log‐linear specification have many attractive features. They are parsimonious, simple to estimate, and imply an ARMA structure for the conditional variance and the realized measure. An empirical application with Dow Jones Industrial Average stocks and an exchange traded index fund shows that a simple Realized GARCH structure leads to substantial improvements in the empirical fit over standard GARCH models that only use daily returns. Copyright © 2011 John Wiley & Sons, Ltd.
Vitamin D–binding protein modifies the vitamin D–bone mineral density relationship
Authors: Powe Camille E , Ricciardi Catherine , Berg Anders H , Erdenesanaa Delger , Collerone Gina , Ankers Elizabeth , Wenger Julia , Karumanchi S Ananth , Thadhani Ravi , Bhan Ishir 
Published: March 2011

Abstract
Studies examining the relationship between total circulating 25-hydroxyvitamin D [25(OH)D] levels and bone mineral density (BMD) have yielded mixed results. Vitamin D–binding protein (DBP), the major carrier protein for 25(OH)D, may alter the biologic activity of circulating vitamin D. We hypothesized that free and bioavailable 25(OH)D, calculated from total 25(OH)D, DBP, and serum albumin levels, would be more strongly associated with BMD than levels of total 25(OH)D. We measured total 25(OH)D, DBP, and serum albumin levels in 49 healthy young adults enrolled in the Metabolic Abnormalities in College-Aged Students (MACS) study. Lumbar spine BMD was measured in all subjects using dual-energy X-ray absorptiometry. Clinical, diet, and laboratory information also was gathered at this time. We determined free and bioavailable (free + albumin-bound) 25(OH)D using previously validated formulas and examined their associations with BMD. BMD was not associated with total 25(OH)D levels (r = 0.172, p = .236). In contrast, free and bioavailable 25(OH)D levels were positively correlated with BMD (r = 0.413, p = .003 for free, r = 0.441, p = .002 for bioavailable). Bioavailable 25(OH)D levels remained independently associated with BMD in multivariate regression models adjusting for age, sex, body mass index, and race (p = .03). It is concluded that free and bioavailable 25(OH)D are more strongly correlated with BMD than total 25(OH)D. These findings have important implications for vitamin D supplementation in vitamin D–deficient states. Future studies should continue to explore the relationship between free and bioavailable 25(OH)D and health outcomes. © 2011 American Society for Bone and Mineral Research.
Back to the future: Moving beyond “mesenchymal stem cells”
Authors: Bianco Paolo 
Published: March 2011

AbstractThe last decade was dominated by dissemination of the notion that postnatal “mesenchymal stem cells,” found primarily in bone marrow but also in other tissues, can generate multiple skeletal and nonskeletal tissues, and thus can be exploited to regenerate a broad range of tissues and organs. The concept of “mesenchymal stem cells” and its applicative implications represent a significant departure from the solidly proven notion that skeletal stem cells are found in the bone marrow (and not in other tissues). Recent data that sharpen our understanding of the identity, nature, origin, and in vivo function of the archetypal “mesenchymal stem cells” (bone marrow skeletal stem cells) point to their microvascular location, mural cell identity, and function as organizers and regulators of the hematopoietic microenvironment/niche. These advances bring back the original concept from which the notion of “mesenchymal stem cells” evolved, and clarify a great deal of experimental data that accumulated in the past decade. As a novel paradigm emerges that accounts for many facets of the biology of skeletal stem cells, a novel paradigm independently emerges for their applicative/translational use. The two paradigms meet each other back in the future. J. Cell. Biochem. 112: 1713–1721, 2011. © 2011 Wiley‐Liss, Inc.
A comparison of statistical downscaling methods suited for wildfire applications
Authors: Abatzoglou John T. , Brown Timothy J. 
Published: March 2011

AbstractPlace‐based data is required in wildfire analyses, particularly in regions of diverse terrain that foster not only strong gradients in meteorological variables, but also complex fire behaviour. However, a majority of downscaling methods are inappropriate for wildfire application due to the lack of daily timescales and variables such as humidity and winds that are important for fuel flammability and fire spread. Two statistical downscaling methods, the daily Bias corrected Spatial Downscaling (BCSD) and the Multivariate Adapted Constructed Analogs (MACA) that directly incorporate daily data from global climate models, were validated over the western US using global reanalysis data. While both methods outperformed results obtained from direct interpolation from reanalysis, MACA exhibited additional skill in temperature, humidity, wind, and precipitation due to its ability to jointly downscale temperature and dew point temperature, and its use of analog patterns rather than interpolation. Both downscaling methods exhibited value added information in tracking fire danger indices and periods of extreme fire danger; however, MACA outperformed the daily BCSD due to its ability to more accurately capture relative humidity and winds. Copyright © 2011 Royal Meteorological Society
Polymer Nanocomposites from Organoclays: Structure and Properties
Authors: Cui Lili , Paul D.R. 
Published: March 2011

AbstractSummary: Polymer nanocomposites formed from organically modified montmorillonite offer the promise of greatly improved properties over those of the matrix polymer, provided the organoclay can be dispersed, or exfoliated, into the polymer matrix to generate high aspect ratio particles. The exfoliation of organoclays in two series of ethylene‐based polymers, ethylene‐vinyl acetate copolymers and sodium ionomers of ethylene‐methyacrylic acid copolymers, is described along with the properties of these nanocomposites.
Nanoclays Dispersion in a PA6/PP Blend by Twin Screw Compounding
Authors: Covas J. A. , Almeida M. F. , Machado A. V. , Larocca N. M. , Pessan L. A. 
Published: March 2011

AbstractSummary: A modified PP and an organoclay (Cloisite C15A, a montmorillonite modified with alkyl ammonium) were incorporated in a PA/PP 70/30 w/w blend by means of twin‐screw melt compounding. The dispersion of the nanoclay into the polymer matrix and its eventual compatibilization effect were investigated by collecting samples along the barrel and characterizing them by X‐ray diffraction (XRD), oscillatory rheometry, scanning and transmission microscopy (SEM and TEM). Chemical and morphological changes occurred mostly during polymer melting. The morphologies of the nanocomposite and of the compatibilized blends were much finer than that of the physical blend. When both the modified PP and the organoclay were present the morphology was even finer, suggesting that the organoclays may produce a compatibilization effect similar to that of PP‐g‐MA.
Spinnability of Nanofilled Polypropylene
Authors: Lorenzi Denis , Sartori Gabriella , Ferrara Giuseppe , Fambri Luca 
Published: March 2011

AbstractSummary: Spinnability of isotactic polypropylene iPP (melt flow 25 g/10 min) was studied after addition of three nanofillers at 0.3% by wt., two nanoclays and a modified hydrotalcite. TGA evidenced the increase of thermooxidation stability in nanofilled iPPs. All these iPP were successfully processed and tensile properties similar to those of iPP fibers were achieved. Processing and mechanical draw ratio were evaluated. Moreover, nanofilled iPP fibers appeared to be more prone to further drawing, as derived from both the maximum attainable strength and the maximum attainable drawing, as presented in the interpretation model of mechanical testing.
Multi‐pH QSAR: II. Regression Analysis Sensitive Enough to Determine the Transition‐State pKa of Human Buccal Absorption
Authors: Scherrer Robert A. 
Published: March 2011

AbstractAn analysis of published human buccal absorption data of an acid and a base at six pH values extends multi‐pH QSAR to an extreme: QSAR on a single compound. The compounds analyzed are 4‐n‐hexylphenylacetic acid and propranolol. This analysis might be considered as much an analysis of the model as the compound, itself. Ionizable compounds undergo a pKa change in the process of absorption. Multi‐pH QSAR allows determination of the pKa of the presumed rate‐limiting step for absorption, which we label the transition‐state pKa (pKaTS). Comparison of the pKaTS with the corresponding aqueous and membrane pKa values provides the extent of molecular penetration at the transition state. It is 49 % of the path length for the arylacetic acid and 73 % for propranolol.
Constrained maximum likelihood estimation of the diffusion kurtosis tensor using a Rician noise model
Authors: Veraart Jelle , Van Hecke Wim , Sijbers Jan 
Published: March 2011

AbstractA computational framework to obtain an accurate quantification of the Gaussian and non‐Gaussian component of water molecules' diffusion through brain tissues with diffusion kurtosis imaging, is presented. The diffusion kurtosis imaging model quantifies the kurtosis, the degree of non‐Gaussianity, on a direction dependent basis, constituting a higher order diffusion kurtosis tensor, which is estimated in addition to the well‐known diffusion tensor. To reconcile with the physical phenomenon of molecular diffusion, both tensor estimates should lie within a physically acceptable range. Otherwise, clinically and artificially significant changes in diffusion (kurtosis) parameters might be confounded. To guarantee physical relevance, we here suggest to estimate both diffusional tensors by maximizing the joint likelihood function of all Rician distributed diffusion weighted images given the diffusion kurtosis imaging model while imposing a set of nonlinear constraints. As shown in this study, correctly accounting for the Rician noise structure is necessary to avoid significant overestimation of the kurtosis values. The performance of the constrained estimator was evaluated and compared to more commonly used strategies during simulations. Human brain data were used to emphasize the need for constrained estimators as not imposing the constraints give rise to constraint violations in about 70% of the brain voxels. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Pediatric palliative care provision around the world: A systematic review
Authors: Knapp Caprice , Woodworth Lindsey , Wright Michael , Downing Julia , Drake Ross , Fowler‐Kerry Sue , Hain Richard , Marston Joan 
Published: March 2011

AbstractPediatric palliative care is recommended by many organizations. Yet, there is no information available on the progress that has been made in providing this care or the gaps that still exist in provision around the world. We conducted a systematic review to address this gap in knowledge. The systematic review identified 117 peer‐reviewed and non‐peer reviewed resources. Based on this information, each country was assigned a level of provision; 65.6% of countries had no known activities, 18.8% had capacity building activities, 9.9% had localized provision, and 5.7% had provision that was reaching mainstream providers. Understanding the geographic distribution in the level of provision is crucial for policy makers and funders. Pediatr Blood Cancer 2011; 57: 361–368. © 2011 Wiley‐Liss, Inc.
Embedding multiple site‐specific functionalities into polymer chains via nitrone‐mediated radical coupling reactions
Authors: Wong Edgar H. H. , Stenzel Martina H. , Junker Tanja , Barner‐Kowollik Christopher 
Published: March 2011

AbstractA facile method to generate polymer materials with embedded functional groups at known and precise positions along the polymer backbone is described. In the presented approach, well‐defined bifunctional poly(isobornyl acrylate)s preformed via atom transfer radical polymerization (ATRP) containing α,ω‐bromo end groups are reactivated and subsequently coupled in a stepwise manner via the nitrone‐mediated radical coupling (NMRC) technique. The generated polymers contain on average four nitrone moieties at evenly spaced locations. The number of embedded functionalities, and thus, the size of the polymer is limited by disproportionation reactions occurring during the nitroxide termination sequence. Using the nitrone as a functional carrier, secondary functionalities can be incorporated into the polymer with ease. To exemplify such an approach, an alkyne‐functionalized nitrone is used to construct a multisegment structure via NMRC reactions followed by postmodification of the obtained polymers with 3‐mercaptopropionic acid via UV‐induced thiol‐yne reactions. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Solution structure and backbone dynamics of the DNA‐binding domain of FOXP1: Insight into its domain swapping and DNA binding
Authors: Chu Yuan‐Ping , Chang Chia‐Hao , Shiu Jia‐Hau , Chang Yao‐Tsung , Chen Chiu‐Yueh , Chuang Woei‐Jer 
Published: March 2011

AbstractFOXP1 belongs to the P‐subfamily of forkhead transcription factors and contains a conserved forkhead DNA‐binding domain. According to size exclusion chromatography analysis, the forkhead domain of FOXP1 existed as a mixture of monomer and dimer. The dissociation constants of the forkhead domain of wild‐type, C61S, and C61Y mutants of FOXP1 were 27.3, 28.8, and 332.0 μM, respectively. In contrast, FOXP1 A39P mutant formed only a monomer. NMR analysis also showed that FOXP1 C61S and C61Y mutants existed as a mixture. The solution structure of FOXP1 A39P/C61Y mutant was similar to the X‐ray structure of the FOXP2 monomer. Comparison of backbone dynamics of FOXP1 A39P/C61Y and C61Y mutants showed that the residues preceding helix 3, the hinge region, exhibited the largest conformational exchange in FOXP1 monomer. The A39 residue of FOXP1 dimer has a lower order parameter with internal motion on the ps‐ns timescale, suggesting that the dynamics of the hinge region of FOXP1 are important in the formation of the swapped dimer. The analysis also showed that the residues exhibiting the motions on the ps‐ns and μs‐ms timescales were located at the DNA‐binding surface of FOXP1, suggesting the interactions between FOXP1 and DNA may be highly dynamic.