bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of lithospheric flexure on magma ascent at large volcanoes on Venus
Authors: McGovern Patrick J. , Rumpf M. Elise , Zimbelman James R. 
Published: October 2013

AbstractLarge volcanoes on Venus exert large vertical loads on the lithosphere, which responds by deflecting downward. Stresses induced by this lithospheric flexure can have a strong influence on magma ascent pathways from the mantle source region to the surface. Here we propose that flexural stresses exert control over the shapes of volcanic edifices on Venus, applying criteria for magma ascent expressed in terms of stress orientations (can vertical dikes form?) and gradients (is magma squeezed upward or downward in a vertical dike?) to determine favored magma ascent paths and locations. For conical edifices emplaced on lithosphere with high elastic thickness Te, (e.g., > 40 km) both sets of magma ascent criteria are satisfied over the entire lithosphere, allowing essentially unimpeded ascent of magma to the surface and the formation of relatively steep edifices. However, for lower values of Te, high adverse stress gradients tend to cut off magma ascent beneath the summit, instead favoring lateral transport of magma at depth to distal regions with gentler stress gradients, resulting in domical edifice shapes. At the lowest values of Te (< 10 km), large short‐wavelength deflections of the lithosphere tend to produce narrow and widely spaced zones of magma ascent: Such zones may produce annular ridges of volcanic material, thereby generating forms characteristic of a subset of features known as “coronae” on Venus. Another subset of coronae may form by intrusive‐based generation of annular fractures at the edge of the summit region of domical edifices, as proposed for Alba Mons on Mars.
Association of Circulating Level of High Mobility Group Box 1 With Disease Activity in Antineutrophil Cytoplasmic Autoantibody–Associated Vasculitis
Authors: Wang Chen , Gou Shen‐Ju , Chang Dong‐Yuan , Yu Feng , Zhao Ming‐Hui , Chen Min 
Published: October 2013

ObjectiveHigh mobility group box 1 (HMGB‐1), a kind of proinflammatory mediator, is associated with inflammatory conditions and tissue damage. Previous studies have reported that circulating HMGB‐1 levels in patients with active antineutrophil cytoplasmic autoantibody (ANCA)–associated vasculitis (AAV) were associated with renal manifestations and burdens of granulomatous inflammation. The current study aimed to investigate whether circulating HMGB‐1 levels were associated with disease activity in AAV.MethodsPlasma samples from 74 patients with AAV in active stage and 65 patients with AAV in remission were collected. The plasma levels of HMGB‐1 were determined by enzyme‐linked immunosorbent assay. Associations between plasma levels of HMGB‐1 with clinical and pathologic parameters were analyzed.ResultsPlasma levels of HMGB‐1 in active AAV patients were significantly higher than those in normal controls and AAV patients in remission (median 6.11 [interquartile range (IQR) 3.25–12.79] ng/ml versus median 1.12 [IQR 0.53–1.39] ng/ml, P< 0.001; median 6.11 [IQR 3.25–12.79] ng/ml versus median 3.04 [IQR 1.97–4.63] ng/ml, P < 0.001, respectively). Correlation analysis showed that plasma levels of HMGB‐1 correlated with initial serum creatinine (r = 0.275, P = 0.018), estimated glomerular filtration rate (r = −0.277, P = 0.017), the Birmingham Vasculitis Activity Score (r = 0.308, P = 0.008), and C‐reactive protein level (r = 0.309, P = 0.008). Among the patients with myeloperoxidase (MPO)–ANCA, those within the first quartile of plasma HMGB‐1 levels had a significantly lower level of MPO‐ANCA than those within the other 3 quartiles.ConclusionCirculating HMGB‐1 levels might reflect the disease activity and renal involvement of AAV vasculitis.
The Direct or Indirect Exporting Decision in Agri‐food Firms
Authors: Fernández‐Olmos Marta , Díez‐Vial Isabel 
Published: October 2013

ABSTRACTSelecting an export channel is one of the most important strategic decisions for any exporting agri‐food firm. This paper presents a unified theoretical framework, integrating the two decisions (i.e., the export decision itself and the export channel decision) by jointly examining the effects of 1) intangible resources, 2) product quality, 3) firm size, and 4) international experience on the probabilities of these decisions. Our findings, obtained by analyzing the export behavior of 177 firms in the DOC Rioja (Spain) wine industry, can help policy‐makers understand how they should promote exports and the export channels for agri‐food firms. [JEL: Q170, M200].
Impediments to the Ability of Canadian Food‐Processing Firms to Compete: Evidence From a Survey on Innovation
Authors: Herath Deepananda 
Published: October 2013

ABSTRACTFactors that impede Canadian food‐processing firms’ ability to compete in domestic and international markets are explored. Business micro‐data were obtained from the Survey on Innovation in the Food Processing Industry in 2004 (n = 809). A higher Canadian dollar against the U.S. dollar was judged to be the most severe of the 10 impediments to the ability of Canadian food processors to compete. Two broader categories of the 10 impediments emerged from a principal component analysis. One category of the impediments relates to private and public standards, while the other relates to vertical and horizontal market power issues. The severity of these impediments is not significantly different among the different size classes of food processors. Subsequent clustering procedures based on these impediments found that the food processors in one cluster were more constrained by all these impediments than their counterparts in the other cluster. Establishment characteristics, such as food subsector classification, and firm strategies, such as export orientation and engagement in R&D activities, were systematically associated with a firm's likelihood of being in the cluster that perceived the impediments to be more severe. Exporting firms are more likely than other firms to perceive each one of the impediments as a constraint. [EconLit Subject Matter Areas: D220; L200; L660].
Spatial foraging in free ranging bearded sakis: Traveling salesmen or Lévy walkers?
Authors: Shaffer Christopher A. 
Published: October 2013

AbstractAccording to optimal foraging theory and most current models of primate socioecology, primate foraging involves a series of decisions concerning when is the most optimal time to leave a food patch, how to travel to the next patch in an efficient manner, and how to minimize the time and distance traveled to all patches throughout the course of the day. In this study, I assess how bearded sakis solve these challenges by presenting data on their patch use, distance minimization, and by comparing their movements with non‐deterministic foraging patterns. The study group, composed of 38 ± 15 individuals, fed significantly longer in higher quality patches (quality defined by patch size and productivity) and in those that contained ripe fruit pulp. However, group size was not a significant predictor of patch occupancy. Bearded sakis traveled relatively directly between food patches, sometimes over distances > 300 m. In addition, they chose the optimal daily path among all patches visited on 9 of 17 occasions, and on average traveled only 21% more than the least distance route. Bearded saki step lengths were consistent with a Brownian rather than a Lévy Walk pattern while waiting times were consistent with a Lévy pattern. However, the distribution of their turning angles indicated a high degree of directional persistence between patches. These results suggest that bearded sakis exploit food patches that are randomly distributed spatially but heterogenous in patch quality. They appear to encode the locations of high quality food patches and minimize travel between them, despite opportunistically feeding from more abundant and randomly distributed, lower quality patches en route. Am. J. Primatol. 76:472–484, 2014. © 2013 Wiley Periodicals, Inc.
Association of Low Baseline Levels of Erythrocyte Folate With Treatment Nonresponse at Three Months in Rheumatoid Arthritis Patients Receiving Methotrexate
Authors: de Rotte M. C. F. J. , de Jong P. H. P. , Pluijm S. M. F. , Bulatović Ćalasan M. , Barendregt P. J. , van Zeben D. , van der Lubbe P. A. , de Sonnaville P. B. , Lindemans J. , Hazes J. M. W. , de Jonge R. 
Published: October 2013

ObjectiveTo investigate whether baseline concentrations of one‐carbon metabolism biomarkers are associated with treatment nonresponse and adverse events in rheumatoid arthritis (RA) patients receiving methotrexate (MTX).MethodsA prospective derivation cohort (n = 285) and validation cohort (n = 102) of RA patients receiving MTX were studied. Concentrations of plasma homocysteine, serum vitamin B12, serum folate, erythrocyte vitamin B6, and erythrocyte folate were determined at baseline and after 3 months of treatment. Nonresponse after 3 months was assessed using the Disease Activity Score in 28 joints (DAS28) and the European League Against Rheumatism (EULAR) response criteria. Adverse events at 3 months were assessed using biochemical parameters and health status questionnaires. Analyses were corrected for baseline DAS28, age, sex, MTX dose, comedications, and presence of the methylenetetrahydrofolate reductase 677TT genotype.ResultsIn the derivation cohort, the mean DAS28 scores at baseline and 3 months were 4.94 and 3.12, respectively, and 78% of patients experienced adverse events. This was similar between the 2 cohorts, despite a lower MTX dose in the validation cohort. Patients with lower levels of erythrocyte folate at baseline had a higher DAS28 at 3 months in both the derivation cohort (β = −0.15, P = 0.037) and the validation cohort (β = −0.20, P = 0.048). In line with these results, lower baseline erythrocyte folate levels were linearly associated with a 3‐month DAS28 of >3.2 in both cohorts (derivation cohort, P = 0.049; validation cohort, P = 0.021) and with nonresponse according to the EULAR criteria (derivation cohort, P = 0.066; validation cohort, P = 0.027). None of the other biomarkers (levels at baseline or changes over 3 months) were associated with the DAS28 or treatment nonresponse. Baseline levels of the biomarkers and changes in levels after 3 months were not associated with incidence of adverse events.ConclusionA low baseline concentration of erythrocyte folate is associated with high disease activity and nonresponse at 3 months after the start of MTX treatment and could be used in prediction models for MTX outcome. None of the investigated one‐carbon metabolism biomarkers were associated with incidence of adverse events at 3 months.
Highly sialylated recombinant human erythropoietin production in large‐scale perfusion bioreactor utilizing CHO‐gmt4 (JW152) with restored GnT I function
Authors: Goh John S. Y. , Liu Yingwei , Liu Haifeng , Chan Kah Fai , Wan Corrine , Teo Gavin , Zhou Xiangshan , Xie Fusheng , Zhang Peiqing , Zhang Yuanxing , Song Zhiwei 
Published: October 2013

AbstractTherapeutic glycoprotein drugs require a high degree of sialylation of their N‐glycans for a better circulatory half‐life that results in greater efficacy. It has been demonstrated that Chinese hamster ovary (CHO) glycosylation mutants lacking N‐acetylglucosaminyltransferase I (GnT I), when restored by introduction of a functional GnT I, produced highly sialylated erythropoietin (EPO). We have now further engineered one of such mutants, JW152, by inactivating the dihydrofolate reductase (DHFR) gene to allow for the amplification of the EPO gene with methotrexate (MTX). Several MTX‐amplified clones maintained the ability to produce highly sialylated EPO and one was selected for culture in a perfusion bioreactor that is used in an existing industrial EPO‐production bioprocess. Extensive characterization of the EPO produced was performed using total sialic quantification, HPAEC‐PAD and MALDI‐TOF MS analyses. Our results demonstrated that the EPO produced by the mutant line exhibits superior sialylation compared to the commercially used EPO‐producing CHO clone cultured under the same conditions. Therefore, this mutant has the industrial potential for producing highly sialylated recombinant EPO and potentially other recombinant glycoprotein therapeutics.
Nanoscale interactions of polyethylene glycol with thermo‐mechanically pre‐treated Pinus radiata biofuel substrate
Authors: Donaldson Lloyd A. , Newman Roger H. , Vaidya Alankar 
Published: October 2013

ABSTRACTNon‐productive adsorption of cellulose degrading enzymes on lignin is a likely reason for reduced rate and extent of enzymatic conversion of lignocellulosic substrate to sugars. Additives such as polyethyleneglycol (PEG) may act as blocking agents in this non‐productive interaction. However, the exact molecular level interactions of PEG with lignin in pre‐treated lignocellulosic substrates are not known. We have used confocal fluorescence microscopy combined with Förster resonance energy transfer (FRET) to reveal molecular level interactions between lignin present in thermo‐mechanically pre‐treated Pinus radiata substrate, and fluorescently labeled PEG. It is demonstrated that PEG interaction with lignin is mainly associated with particles derived from secondary walls, with little or no penetration into fragments derived from the middle lamella. This nanoscale information on the PEG–substrate interaction will assist in rationalizing pre‐treatment methods to reduce the recalcitrance of softwood biofuel substrates. Biotechnol. Biotechnol. Bioeng. 2014;111: 719–725. © 2013 Wiley Periodicals, Inc.
Cel48A from Thermobifida fusca: Structure and site directed mutagenesis of key residues
Authors: Kostylev Maxim , Alahuhta Markus , Chen Mo , Brunecky Roman , Himmel Michael E. , Lunin Vladimir V. , Brady John , Wilson David B. 
Published: October 2013

ABSTRACTLignocellulosic biomass is a potential source of sustainable transportation fuels, but efficient enzymatic saccharification of cellulose is a key challenge in its utilization. Cellulases from the glycoside hydrolase (GH) family 48 constitute an important component of bacterial biomass degrading systems and structures of three enzymes from this family have been previously published. We report a new crystal structure of TfCel48A, a reducing end directed exocellulase from Thermobifida fusca, which shows that this enzyme shares important structural features with the other members of the GH48 family. The active site tunnel entrance of the known GH48 exocellulases is enriched in aromatic residues, which are known to interact well with anhydroglucose units of cellulose. We carried out site‐directed mutagenesis studies of these aromatic residues (Y97, F195, Y213, and W313) along with two non‐aromatic residues (N212 and S311) also located around the tunnel entrance and a W315 residue inside the active site tunnel. Only the aromatic residues located around the tunnel entrance appear to be important for the ability of TfCel48A to access individual cellulose chains on bacterial cellulose (BC), a crystalline substrate. Both Trp residues were found to be important for the processivity of TfCel48A on BC and phosphoric acid swollen cellulose (PASC), but only W313 appears to play a role in the ability of the enzyme to access individual cellulose chains in BC. When acting on BC, reduced processivity was found to correlate with reduced enzyme activity. The reverse, however, is true when PASC is the substrate. Presumably, higher density of available cellulose chain ends and the amorphous nature of PASC explain the increased initial activity of mutants with lower processivity. Biotechnol. Bioeng. 2014;111: 664–673. © 2013 Wiley Periodicals, Inc.
Cell line profiling to improve monoclonal antibody production
Authors: Kang Sohye , Ren Da , Xiao Gang , Daris Kristi , Buck Lynette , Enyenihi Atim A. , Zubarev Roman , Bondarenko Pavel V. , Deshpande Rohini 
Published: October 2013

ABSTRACTMammalian cell culture performance is influenced by both intrinsic (genetic) and extrinsic (media and process) factors. In this study, intrinsic capacity of various monoclonal antibody‐producing Chinese Hamster Ovary (CHO) cell lines was compared by exposing them to the same culture condition. Microarray‐based transcriptomics and LC–MS/MS shotgun proteomics technologies were utilized to obtain expression landscape of different cell lines. Specific transcripts and proteins correlating with productivity, growth rate and cell size have been identified. The proteomics analysis results showed a strong correlation between the intracellular protein expression levels of the recombinant DHFR and productivity. In contrast, neither the light chain nor the heavy chain of the recombinant monoclonal antibody showed correlation to productivity. Other top ranked proteins which demonstrated positive correlation to productivity included the adaptor protein complex subunits AP3D1and AP2B2, DNA repair protein DDB1 and the ER translocation complex component, SRPR. The subunits of molecular chaperone T‐complex protein 1 and the regulator of mitochondrial one‐carbon metabolism MTHFD2 showed negative correlation to productivity. The transcriptomics analysis has identified the regulators of calcium signaling, Tmem20 and Rcan1, as the top ranked genes displaying positive and negative correlation to productivity, respectively. For the second part of the study, the principal component analysis (PCA) was generated to view the underlying global structure of the expression data. A clear division and expression polarity was observed between the two distinct clusters of cell lines, independent of link to productivity or any other traits examined. The primary component of the PCA generated from either transcriptomics or proteomics data displayed a strong correlation to cell size and doubling time, while none of the main principal components showed correlation to productivity. Our findings suggest that productivity is rather a minor feature in the context of global transcriptional or protein expression space. Biotechnol. Bioeng. 2014;111: 748–760. © 2013 Wiley Periodicals, Inc.
Human papillomavirus DNA and p16 expression in Japanese patients with oropharyngeal squamous cell carcinoma
Authors: Kawakami Hisato , Okamoto Isamu , Terao Kyoichi , Sakai Kazuko , Suzuki Minoru , Ueda Shinya , Tanaka Kaoru , Kuwata Kiyoko , Morita Yume , Ono Koji , Nishio Kazuto , Nishimura Yasumasa , Doi Katsumi , Nakagawa Kazuhiko 
Published: October 2013

AbstractHuman papillomavirus (HPV) is a major etiologic factor for oropharyngeal squamous cell carcinoma (OPSCC). However, little is known about HPV‐related OPSCC in Japan. During the study, formalin‐fixed, paraffin‐embedded OPSCC specimens from Japanese patients were analyzed for HPV DNA by the polymerase chain reaction (PCR) and for the surrogate marker p16 by immuno‐histochemistry. For HPV DNA‐positive, p16‐negative specimens, the methylation status of the p16 gene promoter was examined by methylation‐specific PCR. Overall survival was calculated in relation to HPV DNA and p16 status and was subjected to multivariate analysis. OPSCC cell lines were examined for sensitivity to radiation or cisplatin in vitro. The study results showed that tumor specimens from 40 (38%) of the 104 study patients contained HPV DNA, with such positivity being associated with tumors of the tonsils, lymph node metastasis, and nonsmoking. Overall survival was better for OPSCC patients with HPV DNA than for those without it (hazard ratio, 0.214; 95% confidence interval, 0.074–0.614; P = 0.002). Multivariate analysis revealed HPV DNA to be an independent prognostic factor for overall survival (P = 0.015). Expression of p16 was associated with HPV DNA positivity. However, 20% of HPV DNA‐positive tumors were negative for p16, with most of these tumors manifesting DNA methylation at the p16 gene promoter. Radiation or cisplatin sensitivity did not differ between OPSCC cell lines positive or negative for HPV DNA. Thus, positivity for HPV DNA identifies a distinct clinical subset of OPSCC with a more favorable outcome in Japanese.
Exploring Internal Structure of Nanoporous Glasses Obtained by Leaching of Phase‐Separated Alkali Borosilicate Glasses
Authors: Shakhov Alexander , Reichenbach Christian , Kondrashova Daria , Zeigermann Philipp , Mehlhorn Dirk , Enke Dirk , Valiullin Rustem 
Published: October 2013

AbstractMesoporous glasses – the leaching products of phase‐separated alkali borosilicate glasses – are widely used in fundamental research and practical applications. In this work, the option to control their internal mesopore structure by varying the conditions of microphase separation has been studied. Structure and transport characterization of a family of nanoporous glasses obtained under different conditions has been performed using a combination of several experimental techniques, including gas adsorption, nuclear magnetic resonance cryoporometry and diffusometry.
Prepubertal Fischer 344 rats display stronger morphine‐induced taste avoidance than prepubertal Lewis rats
Authors: Hurwitz Zachary E. , Cobuzzi Jennifer L. , Merluzzi Andrew P. , Wetzell Bradley , Riley Anthony L. 
Published: October 2013

ABSTRACTThe present report asked if the previously reported differences in morphine‐induced conditioned taste avoidance between adult F344 and LEW rats (F344 > LEW) are also evident in prepubescence (early adolescence). To assess this possibility, adult (Experiment 1) and prepubertal (Experiment 2) F344 and LEW rats were assessed for their ability to acquire morphine‐induced taste avoidance (0, 3.2, 10, or 18 mg/kg) in a modified taste avoidance procedure. In each experiment, rats of both strains were given repeated pairings of saccharin and morphine followed by a final two‐bottle avoidance test. Adult and prepubertal F344 subjects displayed a more rapid acquisition of the avoidance response as well as stronger suppression of consumption than their LEW counterparts. These data suggest the strains differ in their sensitivity to the aversive effects of morphine and that this differential sensitivity is evident early in development and is developmentally stable. The basis for these strain differences in morphine‐induced avoidance was discussed. © 2013 Wiley Periodicals, Inc. Dev Psychobiol 56: 979–988, 2014.
Genetic monogamy despite variable ecological conditions and social environment in the cooperatively breeding apostlebird
Authors: Warrington Miyako H. , Rollins Lee Ann , Raihani Nichola J. , Russell Andrew F. , Griffith Simon C. 
Published: October 2013

AbstractMating strategies may be context‐dependent and may vary across ecological and social contexts, demonstrating the role of these factors in driving the variation in genetic polyandry within and among species. Here, we took a longitudinal approach across 5 years (2006–2010), to study the apostlebird(Struthidea cinerea),an Australian cooperatively breeding bird, whose reproduction is affected by ecological “boom and bust” cycles. Climatic variation drives variation in the social (i.e., group sizes, proportion of males and females) and ecological (i.e., plant and insect abundance) context in which mating occurs. By quantifying variation in both social and ecological factors and characterizing the genetic mating system across multiple years using a molecular parentage analysis, we found that the genetic mating strategy did not vary among years despite significant variation in rainfall, driving primary production, and insect abundance, and corresponding variation in social parameters such as breeding group size. Group sizes in 2010, an ecologically good year, were significantly smaller (mean = 5.8 ± 0.9,n = 16) than in the drought affected years, between 2006 and 2008, (mean = 9.1 ± 0.5,n = 63). Overall, apostlebirds were consistently monogamous with few cases of multiple maternity or paternity (8 of 78 nests) across all years.