bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proglacial sediment trapping in recently formed Silt Lake, upper Lillooet Valley, Coast Mountains, British Columbia
Authors: Schiefer Erik , Gilbert Robert 
Published: January 2008

AbstractThe sedimentology of proglacial Silt Lake was assessed by lake sediment coring and monitoring of lacustrine processes during a late‐summer period of high glacier melt to characterize sediment delivery from the heavily glacierized catchment and investigate the sediment trapping dynamics of this upland lake. A complete varve chronology was established for a distal basin of the lake which was exposed by Lillooet Glacier retreat between 1947 and 1962. The varve record showed decreasing sedimentation rates in the basin while the glacier retreated, and as the lake became free of ice contact in the early 1970s. Although recession has continued over recent decades, and glacier proximity to the lake has, therefore, continued decreasing, lacustrine sedimentation rates are now accelerating due to changing basin morphometry caused by delta progradation. Over shorter time scales, lake sedimentation patterns respond to changing runoff conditions, including late‐summer glacier melt intensity, intra‐annual flooding events, diumal runoff fluctuations, and within‐lake turbidity currents. Turbidity currents included quasi‐regular flows during high diurnal discharges and an episodic flushing of temporarily stored sediment from the sandur or delta at a time of low stage. Suspended sediment yield to Silt Lake is estimated to exceed 103 Mg km−2 a−1, a magnitude that surpasses previous local and regional yield estimates for the glacierized headwaters of the Lillooet River valley. Since Silt Lake currently traps a significant prooportion of that upland sediment supply, and the trapping efficiency of the basin has been variable at decadal time scales, the formation and continued development of Lilt Lake has likely had a significant influence on downstream sediment delivery. Lacustrine sediment‐based proxies of long‐term hydroclimatic variability being developed in glacially distal settings should include provisions for dynamic sediment trapping effects in upstream water bodies that often form in the active proglacial environment. Copyright © 2008 John Wiley & Sons, Ltd.
Bioactivity and osteoblast response of the micro‐arc oxidized zirconia films
Authors: Han Yong , Yan Yuanyuan , Lu Chunguo , Zhang Yumei , Xu Kewei 
Published: February 2008

AbstractZirconia films containing Ca and P were prepared by micro‐arc oxidation (MAO) of zirconium. The microstructure, in vitro bioactivity, and primary osteoblast response of the films were investigated as a function of the applied voltages in the range of 400–500 V. The results indicate that the MAO‐formed zirconia films are porous and nanocrystalline, and predominantly composed of tetragonal zirconia (t‐ZrO2). The pores and grains sizes and t‐ZrO2 content of the films tend to increase with the applied voltages. The zirconia films formed at higher voltages have higher amount of CaO and phosphate and slightly lower amount of ZrOH groups. Although, all of the zirconia films can be fully covered by bone‐like apatite after immersion in simulated body fluids (SBF) within 10 days, there exists remarkable difference in apatite‐induced time. The apatite‐forming ability of the films is not only ascribed to ZrOH groups on the surfaces, but also enhanced by the CaO and phosphate ions incorporated into ZrO2. Osteoblasts on the films are observed to attach, proliferate, and grow in good state, and have good alkaline phosphatase activity. It is suggested that the MAO‐formed ZrO2 films exhibit favorable bioactivity and biocompatibility. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Peroxiredoxin 6 as an antioxidant enzyme: Protection of lung alveolar epithelial type II cells from H2O2‐induced oxidative stress
Authors: Wang Yan , Feinstein Sheldon I. , Fisher Aron B. 
Published: February 2008

AbstractWe evaluated the antioxidant role of peroxiredoxin 6 (Prdx6) in primary lung alveolar epithelial type II cells (AEC II) that were isolated from wild type (WT), Prdx6−/−, or Prdx6 transgenic (Tg) overexpressing mice and exposed to H2O2 at 50–500 µM for 1–24 h. Expression of Prdx6 in Tg AEC II was sevenfold greater than WT. Prdx6 null AEC II exposed to H2O2 showed concentration‐dependent cytotoxicity indicated by decreased “live/dead” cell ratio, increased propidium iodide (PI) staining, increased annexin V binding, increased DNA fragmentation by TUNEL assay, and increased lipid peroxidation by diphenylpyrenylphosphine (DPPP) fluorescence. Compared to Prdx6 null cells, oxidant‐mediated damage was significantly less in WT AEC II and was least in Prdx6 Tg cells. Thus, Prdx6 functions as an antioxidant enzyme in mouse AEC II. Prdx6 has been shown previously to reduce phospholipid hydroperoxides and we postulate that this activity is a major mechanism for the effectiveness of Prdx6 as an antioxidant enzyme. J. Cell. Biochem. 104: 1274–1285, 2008. © 2008 Wiley‐Liss, Inc.
Synthesis of [1,2‐3H]ethylamine hydrochloride and [3H]‐labeled apadenoson for a human ADME study
Authors: Hong Yang , Bonacorsi Samuel J. , Tian Yuan , Gong Sharon , Zhang Donglu , Humphreys W. Griffith , Balasubramanian Balu , Cheesman Edward H. , Zhang Zhiqin , Castner James F. , Crane Paul D. 
Published: January 2008

AbstractTritium‐labeled [1,2‐3H]ethylamine hydrochloride was prepared through a multiple‐step sequence in high radioactive specificity. The labeled amine was isolated in high purity following cartridge filtration and used subsequently in the synthesis of [N‐ethyl‐1,2‐3H]apadenoson, an adenosine A2a receptor agonist. The overall yield for this transformation was 56% and the radiochemical purity of the final product was greater than 99%. Copyright © 2008 John Wiley & Sons, Ltd.
Comparison of global gridded precipitation products over a mountainous region of Africa
Authors: Dinku T. , Connor S. J. , Ceccato P. , Ropelewski C. F. 
Published: January 2008

AbstractFive gridded monthly precipitation products are evaluated using a gauge network over complex topography in Africa. The global gridded products considered are produced by the Global Precipitation Climatology Center (GPCC), NOAA Climate Prediction Center (NOAA–CPC), and the Climate Research Unit at the University of East Anglia (UEA–CRU). Three different products from GPCC are available at multiple spatial resolutions: 0.5, 1 and 2.5° ; the NOAA–CPC product has a spatial resolution of 2.5° while that of UEA–CRU is 0.5° . Comparisons of the GPCC and UEA–CRU products are carried out at spatial resolutions of 0.5, 1 and 2.5° , while NOAA–CPC is compared with the other products only at 2.5° resolution. There is very strong agreement between the gridded global products and the reference raingauge data. Average correlation coefficients are about 0.95, 0.92, and 0.90 at 2.5, 1.0 and 0.5° spatial resolutions, respectively. Both systematic and random errors are reasonably low. The performance of these products is highest during the wettest season (Jun–Aug), and relatively poor during the dry season (Dec–Feb). The seasonal differences are more prominent at high resolution. These results are very encouraging, particularly, when considering the complex terrain of the validation site. Copyright © 2008 Royal Meteorological Society
A constructive version of Birkhoff's theorem
Authors: Carlström Jesper 
Published: January 2008

AbstractA version of Birkhoff's theorem is proved by constructive, predicative, methods. The version we prove has two conditions more than the classical one. First, the class considered is assumed to contain a generic family, which is defined to be a set‐indexed family of algebras such that if an identity is valid in every algebra of this family, it is valid in every algebra of the class. Secondly, the class is assumed to be closed under inductive limits. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Real numbers and other completions
Authors: Richman Fred 
Published: January 2008

AbstractA notion of completeness and completion suitable for use in the absence of countable choice is developed. This encompasses the construction of the real numbers as well as the completion of an arbitrary metric space. The real numbers are characterized as a complete Archimedean Heyting field, a terminal object in the category of Archimedean Heyting fields. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A constructive semantics for non‐deducibility
Authors: Ciraulo Francesco 
Published: January 2008

AbstractThis paper provides a constructive topological semantics for non‐deducibility of a first order intuitionistic formula. Formal topology theory, in particular the recently introduced notion of a binary positivity predicate, and co‐induction are two needful tools. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Resolution of the uniform lower bound problem in constructive analysis
Authors: Palmgren Erik 
Published: January 2008

AbstractIn a previous paper we constructed a full and faithful functor ℳ︁ from the category of locally compact metric spaces to the category of formal topologies (representations of locales). Here we show that for a real‐valued continuous function f, ℳ︁(f) factors through the localic positive reals if, and only if, f has a uniform positive lower bound on each ball in the locally compact space. We work within the framework of Bishop constructive mathematics, where the latter notion is strictly stronger than point‐wise positivity. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Relation Reflection Scheme
Authors: Aczel Peter 
Published: January 2008

AbstractWe introduce a new axiom scheme for constructive set theory, the Relation Reflection Scheme (RRS). Each instance of this scheme is a theorem of the classical set theory ZF. In the constructive set theory CZF–, when the axiom scheme is combined with the axiom of Dependent Choices (DC), the result is equivalent to the scheme of Relative Dependent Choices (RDC). In contrast to RDC, the scheme RRS is preserved in Heyting‐valued models of CZF– using set‐generated frames. We give an application of the scheme to coinductive definitions of classes. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Generalising compactness
Authors: Diener Hannes 
Published: January 2008

AbstractWorking within the framework of Bishop's constructive mathematics, we will show that it is possible to define compactness in a more general setting than that of uniform spaces. It is also shown that it is not possible to do this in a topological space. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cooperative interaction of H3O+ with 1,3‐alternate tetrapropoxycalix[4]arene: NMR and theoretical study
Authors: Kříž Jaroslav , Dybal Jiří , Makrlík Emanuel , Budka Jan 
Published: January 2008

AbstractInteraction of H3O+ or H5O2+ with 1,3‐alternate tetrapropoxycalix[4]arene (1) was studied in nitrobenzene and dichloromethane using 1H and 13C NMR including transverse and rotating‐frame relaxations and density functional level of theory (DFT) quantum calculations. According to NMR, the ion forms an equimolecular complex with 1 with the equilibrium constant K being 3.97 × 103 L.mol−1 at 296 K. The ions are bound by strong hydrogen bonds to the phenoxy‐oxygen atoms of one half of 1 and by a medium‐strong hydrogen bond to the π system of the aromatic rings of the other half. The complex appears to have C4h symmetry in NMR even when cooling its solution down to 213 K, which could be due either to a genuine symmetry of the complex (if the ion is H5O2+) or to fast structure averaging by ion exchange processes (if the ion is H3O+). Therefore, the dynamics of the system was studied. Using two independent NMR methods (transverse and rotating‐frame relaxation), two different exchange processes were discerned with correlation times 25 × 10−6 and 5 × 10−6 s, the first being clearly intermolecular and the other being apparently intramolecular. The energetic aspects of the possible exchange processes were examined by DFT quantum calculations. Rotation of H3O+ ion within one binding site with the energy barrier 8.13 kcal/mol is easily possible. Intermolecular exchange by freeing the ion from the complex has too high a barrier but cooperative interaction of the ion with additional water molecules makes it viable. The intramolecular exchange (or hopping) of the H3O+ ion between the two sites of the molecule is not viable in the classical manner, the barrier being 25.6 kcal/mol. Quantum tunneling of the ion is highly improbable, too. Alternative mechanisms including concerted two‐ion intermolecular exchange and cooperative interaction with another bound water molecule including complexation with proton dihydrate H5O2+ are discussed. Copyright © 2008 John Wiley & Sons, Ltd.
Conformational equilibria of trans ‐3‐X‐cyclohexanols (X = Cl, Br, CH3 and OCH3). A low temperature NMR study and theoretical calculations
Authors: de Oliveira Paulo R. , Rittner Roberto 
Published: January 2008

AbstractThe integration of 1H and 13C NMR spectra, at − 90 °C in CS2/CD2Cl2 (9:1), for the trans‐3‐chlorocyclohexanol (1), trans‐3‐bromocyclohexanol (2), and trans‐3‐methoxycyclohexanol (4) showed that the equatorial‐axial (ea) conformer occurs as ca 63, 63, and 69% in the conformational equilibrium, respectively. This corresponds to the following ΔGea–ae values (from 1H spectrum): − 0.32 ± 0.01, − 0.32 ± 0.04, − 0.48 ± 0.05 kcal mol−1; and to (from 13C spectrum): − 0.31 ± 0.04, − 0.35 ± 0.05, and − 0.44 ± 0.01 kcal mol−1, respectively, in very good agreement within both series. Thus, although bromine is bulkier than chlorine, the 1,3‐diaxial steric effects are similar in these equilibria. However, the integration of 1H NMR spectrum for the trans‐3‐methylcyclohexanol (3) gave 90% of the 3ae conformer in the equilibrium, at − 90 °C on CS2/CD2Cl2 (9:1), corresponding to a ΔGea–ae value of 1.31 ± 0.02 kcal mol−1. The values obtained through the additivity rule, with data from monosubstituted cyclohexanes (ΔGAd = ΔGX + ΔGOH), for compounds 1, 2, and 4 (−0.37 ± 0.15, − 0.34 ± 0.09, and − 0.46 ± 0.04 kcal mol−1, respectively) are in very good agreement with the experimental values, but it is significantly smaller for compound 3 (0.79 ± 0.02 kcal mol−1). Theoretical calculations through different levels of theory (HF/6‐311 + g**, B3LYP/6‐311 + g**, MP2/6‐31 + g**, and CBS‐4M) showed that CBS‐4M is the best method for the study of conformational equilibria for these systems, since it provides ΔGea–ae values similar to the experimental values. Copyright © 2008 John Wiley & Sons, Ltd.
Complete assignments of 1H and 13C NMR data for three new arylnaphthalene lignan from Justicia procumbens
Authors: Liu Guorui , Wu Jun , Si Jianyong , Wang Junmei , Yang Meihua 
Published: January 2008

AbstractThree new arylnaphthalene lignans, named neojusticin C (1), procumbenoside C (2) and procumbenoside D (3), have been isolated from the whole plant of Justicia procumbens, together with three known ones, justicidinoside B (4), justicidinoside C (5), and diphyllin‐1‐O‐β‐D‐apiofuranoside (6). The complete assignments of 1H and 13C NMR data for three new lignans were first obtained by means of 2D NMR techniques, including HSQC and HMBC. Copyright © 2008 John Wiley & Sons, Ltd.
Quinuclidine complex with α‐cyclodextrin: a diffusion and 13C NMR relaxation study
Authors: Aski Sahar Nikkhou , Kowalewski Jozef 
Published: January 2008

AbstractThe stability of an inclusion complex of quinuclidine with α‐cyclodextrin in solution was investigated by NMR measurements of the translational diffusion coefficient. A 1:1 stoichiometry model yielded an association constant of 35 ± 3 M−1. The guest molecules exchange rapidly between the host cavity and the bulk solution. The reorientational dynamics of the guest and host molecules was studied using carbon‐13 NMR relaxation at two magnetic fields. The relaxation of the host nuclei showed very little dependence on the guest‐host concentration ratio, while the 13C spins in quinuclidine were sensitive to the solution composition. Using mole‐fraction data, it was possible to extract the relaxation parameters for the bound and free form of quinuclidine. Relaxation rates of the guest molecule, free in solution, were best described by an axially symmetric model, while the data of the complex species were analyzed using the Lipari‐Szabo method. Applying the axially symmetric model to the complexed quinuclidine indicated that the anisotropy of its reorientation in the bound form was increased. Copyright © 2008 John Wiley & Sons, Ltd.
Stereochemistry of cyclopentane derivatives from 2, 3JCH dependence on dihedral angle (θ HCCX)
Authors: Lacerda Valdemar , da Silva Gil V. J. , Constantino Mauricio G. , dos Santos Reginaldo B. , de Castro Eustáquio V. R. , Silva Renzo C. 
Published: January 2008

AbstractThe 2, 3JCH dependence on dihedral angle (θ HCCX) for cyclopentane derivatives was investigated. We observed that the combined use of experimentally obtained 2, 3JCH values and the theoretically determined dihedral angles between the corresponding nuclei can be used to infer the relative stereochemistry of the ring substituents in cyclopentane derivatives. There is a good correlation between the magnitude of 3JCH and the dihedral angle between the hydrogen and the coupled carbon (R2 = 0.88). Copyright © 2008 John Wiley & Sons, Ltd.
Work increases the incidence of carpal tunnel syndrome in the general population
Authors: Roquelaure Yves , Ha Catherine , Pelier‐Cady Marie‐Christine , Nicolas Guillaume , Descatha Alexis , Leclerc Annette , Raimbeau Guy , Goldberg Marcel , Imbernon Ellen 
Published: January 2008

AbstractThe purpose of this study was to estimate the incidence of carpal tunnel syndrome (CTS) in a general population according to employment status and to assess the proportion of cases attributable to work. CTS occurring in patients aged 20–59 years living in the French Maine and Loire region were included prospectively from 2002 to 2004. Medical and occupation history was gathered by mailed questionnaire. Incidence rates of CTS and relative risks (RRs) of CTS were computed in relation to employment status. The attributable fractions of risk of CTS to work among the exposed persons (AFEs) were calculated. A total of 1168 patients (819 women, 349 men) were included during the 3‐year period. The mean incidence rate of CTS per 1000 person‐years was higher in employed than unemployed persons (1.7 vs. 0.8 in women and 0.6 vs. 0.3 in men). The excess risk of CTS was statistically significant for male (RR 4.2) and female (RR 3.0) blue‐collar workers and female lower‐grade white‐collar workers (RR 2.5). The AFE to work in general was 47% (95% confidence interval: 39–54) in women. AFEs reached higher values in female blue‐collar workers [67% (65–68)] and lower‐grade services, sales, and clerical white‐collar workers [61% (57–64)]. The AFE in male blue‐collar workers was 76% (72–80). These data show a higher incidence of CTS in the working than the non‐working population and suggest that a substantial proportion of CTS cases diagnosed in lower‐grade white‐collar and blue‐collar workers are attributable to work. Muscle Nerve, 2008
Histopathological basis of Horner's syndrome in obstetric brachial plexus palsy differs from that in adult brachial plexus injury
Authors: Huang Yi‐Gang , Chen Liang , Gu Yu‐Dong , Yu Guang‐Rong 
Published: January 2008

AbstractAlthough Horner's syndrome is usually taken as an absolute indicator of avulsions of the C8 and T1 ventral roots in adult brachial plexus injury, its pathological basis in obstetric brachial plexus palsy (OBPP) is unclear. We therefore examined the morphological mechanism for the presence of Horner's syndrome in brachial plexus injury in infants and adults. Some axons of sympathetic preganglionic neurons in T1 innervate the superior cervical ganglion via the C7 ventral root in infants but not in adults. Therefore, the presence of Horner's syndrome may relate in part to avulsion of the C7 root in OBPP. These findings suggest that Horner's syndrome in OBPP is not necessarily indicative of avulsions of the C8 and T1 roots, as it can occur with avulsion of the C7 root. Muscle Nerve, 2008
Changes of elbow kinematics and kinetics during 1 year after stroke
Authors: Mirbagheri Mehdi M. , Tsao Cheng‐Chi , Rymer W. Zev 
Published: January 2008

AbstractA precise description of the natural history of motor recovery after stroke provides a framework for understanding the mechanisms underlying this improvement and for tracking the efficacy of rehabilitation treatments. To characterize the time course of this change in motor impairment, we examined voluntary elbow movements in hemiparetic stroke survivors over a period of 1 year after stroke. Based on the possibility that both central nervous system and muscle factors could contribute to the observed clinical state, we hypothesized that we should observe at least two major recovery patterns of motor impairment. To explore these predictions, we assessed elbow movement range, movement speed, and isometric force generation. Subjects were examined five times over the 12‐month period. We used the “growth mixture” model to characterize recovery of these measures, and the Fugl‐Meyer scale (FMS) of upper‐extremity function at 1 month to predict the recovery. We observed two distinct recovery classes. Class 1 started with low values for the physiological measures, and these increased over time, whereas class 2 tended to start with higher values and showed widely divergent recovery patterns. Using the logistic regression model, the impact of FMS on class membership was estimated for each parameter. Based on these data, we were able to accurately predict arm impairment recovery at different time‐points in the first year, information of great potential value for planning targeted therapeutic interventions. Muscle Nerve, 2008
Hypoxia‐inducible factor is expressed in giant cell tumour of bone and mediates paracrine effects of hypoxia on monocyte–osteoclast differentiation via induction of VEGF
Authors: Knowles HJ , Athanasou NA 
Published: February 2008

AbstractHypoxia is an important regulator of bone biology and stimulates osteoclast differentiation from monocytic precursors. Hypoxia‐inducible factor (HIF) is a key pro‐tumourigenic transcription factor mediating pathways of hypoxia‐inducible gene expression. We have described expression of HIF‐1α and HIF‐2α in the multi‐nucleated, osteoclast‐like giant cells and the mononuclear stromal component of giant cell tumour of bone (GCTB), a locally osteolytic primary bone tumour. HIF induction was observed in culture in the osteoblastic MG‐63 cell line, primary GCTB stromal cells, and monocyte‐derived osteoclasts following stimulation with hypoxia (0.1% O2) or the osteoclastogenic cytokines hepatocyte growth factor (HGF) and macrophage colony‐stimulating factor (M‐CSF). This was accompanied by increased expression of the downstream target genes Bcl‐2/adenovirus E1B 19 kD‐interacting protein 3 (BNIP3), Glut‐1, and vascular endothelial growth factor (VEGF). As VEGF can substitute for M‐CSF to support osteoclastogenesis in the presence of receptor activator for nuclear factor κB ligand (RANKL), we assessed the effect of MG‐63 hypoxic conditioned media on osteoclast differentiation. In the presence of RANKL, hypoxic conditioned media induced the formation of active osteoclasts, as assessed from the numbers of TRAP‐positive multi‐nucleated cells and the area of lacunar bone resorption, which was inhibited by co‐incubation with a neutralizing anti‐VEGF antibody. Targeted siRNA ablated HIF‐1α and/or HIF‐2α expression in MG‐63 cells and reduced hypoxic secretion of VEGF. Hypoxic conditioned media from cells treated with siRNA for (HIF‐1α + HIF‐2α) produced a significant decrease in osteoclast number (p < 0.005) and activity (p < 0.05) in comparison with the scrambled siRNA control. These results suggest that local hypoxia could indirectly influence osteoclastogenesis via autocrine and paracrine secretion of VEGF under the control of HIF. This is potentially an important mechanism of pathogenesis for GCTB and other osteolytic lesions. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.