bluuebunny/crossref_metadata_2025_split huggingface dataset:
Migration of CXCR4 gene‐modified bone marrow‐derived mesenchymal stem cells to the acute injured kidney
Authors: Liu Nanmei , Tian Jun , Cheng Jin , Zhang Jinyuan 
Published: June 2013

ABSTRACTBone marrow‐derived mesenchymal stem cells (BMSCs) can migrate to the injured kidney after acute kidney injury (AKI) with limited efficiency. This study investigated the effect of CXCR4 overexpression on BMSC migration to the AKI kidney and the possible mechanisms. CXCR4 gene‐modified BMSCs (CXCR4‐BMSCs) and null‐BMSCs were prepared and transplanted into the AKI mice. Blood indicators, histology, expression of stromal cell‐derived factor 1 (SDF‐1), and BMSC migration were investigated. Hypoxia/re‐oxygenation‐pretreated renal tubular epithelial cells (HR‐RTECs) were prepared to generate AKI in vitro. The chemotaxis experiment was performed using the transwell chamber. The phosphorylation of AKT and MAPK in the BMSCs was also investigated. The CXCR4‐BMSCs showed a remarkable expression of CXCR4. The SDF‐1 expression in the AKI renal tissue was increased. CXCR4‐BMSCs transplantation sharply increased the accumulation of BMSCs in the renal tissue, which was consistent with a greater improvement of renal function. The in vitro experiments showed that the migration of BMSCs to the HR‐RTEC culturing chamber was CXCR4‐dependent, and could be fully inhibited by AMD3100, a CXCR4‐specific antagonist. The migration could also be partly blocked by either LY294002 (PI3K inhibitor) or PD98059 (MAPK inhibitor). Phosphorylated Akt and MAPK were increased in the BMSCs co‐cultured with HR‐RTECs and their expression was the highest in the CXCR4‐BMSCs, which could be recovered by AMD3100. Overexpression of CXCR4 gene could enhance BMSC migration to the kidney area after AKI. The SDF‐1/CXCR4 axis via its activation of PI3K/AKT and MAPK in BMSCs could be the possible mechanisms underlying this function. J. Cell. Biochem. 114: 2677–2689, 2013. © 2013 Wiley Periodicals, Inc.
Targeted gene delivery with noncovalent electrostatic conjugates of sgc‐8c aptamer and polyethylenimine
Authors: Shahidi‐Hamedani Nasim , Shier Wayne T. , Moghadam Ariaee Faezeh , Abnous Khalil , Ramezani Mohammad 
Published: June 2013

AbstractBackgroundSeveral strategies have been shown to improve the transfection efficiency of polyethylenimine (PEI) as a nonviral gene delivery vector. In the present study, a nucleic acid aptamer specific for protein tyrosine kinase 7 (PTK7) surface marker, sgc‐8c, was conjugated electrostatically to pre‐formed 10‐kDa PEI/plasmid DNA polyplexes, and the ability of the conjugate to transfer genetic material was evaluated in MOLT‐4 human acute lymphoblastic leukemia T‐cells, which express PTK7 on their surface.MethodsPolyplexes (plasmid DNA–vector conjugates), prepared using PEI–sgc‐8c conjugate and pCMVLuc as a reporter gene, were characterized in terms of particle size, surface charge and the extent of DNA condensation. Polyplexes were also evaluated for cytotoxicity using the MTS colorimetric assay, as well as for transfection efficiency in MOLT‐4 cells, and compared with the results obtained in U266 cells, which lack cell surface PTK7.ResultsRelative to pDNA/PEI, the size of pDNA/PEI/sgc‐8c aptamer polyplexes increased with decreasing zeta potential. In MOLT‐4 cells, pDNA/PEI/sgc‐8c aptamer polyplexes exhibited an almost six‐ to eight‐fold increase in transfection efficiency compared to that of pDNA/PEI polyplex, indicating that conjugation of sgc‐8c aptamer to pre‐formed 10‐kDa PEI/plasmid DNA polyplexes achieved effective targeting without covalent attachment, whereas receptor‐mediated conducted transfection was confirmed by performing a competitive transfection experiment and a cellular uptake study.ConclusionsThe results of the present study provide an example of the usefulness of a nucleic acid aptamer in the form of noncovalent, electrostatic conjugates as an approach for enhancing the transfection efficiency of a polycation vector such as PEI without significant induced cytotoxicity. Copyright © 2013 John Wiley & Sons, Ltd.
Kinetics of Iodous Acid Disproportionation
Authors: Schmitz Guy , Furrow Stanley D. 
Published: June 2013

ABSTRACTThe iodous acid disproportionation is autocatalytic, and it is not easy to measure the rate constant of the step 2IO2H → IO3− + IOH + H+ separately. Hg(II) was used previously to suppress the autocatalytic pathway, but this method presents difficulties discussed in this work. A more effective method is the use of crotonic acid, an effective IOH scavenger. It suppresses side reactions, and a purely second‐order rate law is obtained. The rate constant decreases from 5 to 0.2 M−1 s−1 when the sulfuric acid concentration increases from 0.08 to 0.60 M. The observed decrease could be explained if IO2− reacts faster than IO2H. This may have consequences for the mechanism of the oscillating Bray–Liebhafsky reaction.
A spectral assessment review of current satellite‐only and combined Earth gravity models
Authors: Tsoulis Dimitrios , Patlakis Konstantinos 
Published: June 2013

AbstractThe realization over the last decade of dedicated gravity field satellite missions enabled the production of a series of new satellite‐only and combined models for the Earth's gravity field. Using different sensors, measurement techniques, and algorithmic procedures, the final product in each case is a set of spherical harmonic coefficients representing the series expansion of the gravitational potential up to a certain maximum degree, depending on the mission characteristics and the range of the available data. The present review performs a detailed quantified analysis of a representative selection of currently available CHAMP (Challenging Minisatellite Payload), GRACE (Gravity Recovery and Climate Experiment), GOCE (Gravity Field and Steady‐State Ocean Circulation Explorer), and combined Earth gravity models. In this comparative analysis, we also include the so‐called topographic/isostatic gravity models that represent the contribution of global digital elevation maps for the topography and ocean bathymetry. Applying a range of available spatial and spectral accuracy and assessment measures, such as correlation per degree and order, smoothing per degree and order, signal‐to‐noise ratio, gain, degree variances, and error degree variances, one gains a quantified “peek” inside the quality of these models spanning over their whole spectrum. The applied error and assessment measures are defined both in an absolute and relative manner with respect to other similar models or some reference Earth gravity models. Furthermore, the nature of the performed analysis (degree‐wise, order‐wise, and cumulative) permits the identification of distinct spectral bandwidths in these models, enables the quantification of some standard features of the observed field, such as its “long wavelength”, “short wavelength”, or “very high frequency part”, and specifies the attenuation of the gravity signal with increasing altitude from the Earth's surface. An examination of the assessment quantities reveals certain bandwidths of these models with characteristic statistical features. A band‐limited synthesis of these bandwidths in the space domain quantifies the corresponding contributions in terms of selected gravity field functionals, including second‐order derivatives at GOCE altitude.
Log‐linear modelling of pairwise interobserver agreement on a categorical scale
Authors: Becker Mark P. , Agresti Alan 
Published: June 2013

AbstractThis article uses log‐linear models to describe pairwise agreement among several raters who classify a sample on a subjective categorical scale. The models describe agreement structure simultaneously for second‐order marginal tables of a multidimensional cross‐classification of ratings. Practical difficulties arise in fitting the models, because models refer to pairwise marginal tables of a very large and sparse table. A standard analysis that treats the marginal tables as independent yields consistent estimates of model parameters, but not of the covariance matrix of the estimates. We estimate the covariance matrix using the jackknife. We apply the models to describe agreement between evaluations made by seven pathologists of carcinoma in situ of the uterine cervix, using a five‐level ordinal scale. Previous analyses showed differences among the pathologists in their pairwise levels of agreement, but we observe near homogeneity in the dependence structure of their ratings.
Mode C flow transition behind a circular cylinder with a near-wake wire disturbance
Authors: Yildirim I. , Rindt C. C. M. , van Steenhoven A. A. 
Published: June 2013

AbstractThe three-dimensional transition of the flow behind a circular cylinder with a near-wake wire disturbance has been investigated experimentally. The asymmetric placement of a wire in the near-wake region of the cylinder causes an unnatural mode of shedding to occur, namely mode C. We performed flow visualization and particle image velocimetry (PIV) experiments to investigate the influence of the wire on various properties of the flow, such as the dynamics of the streamwise secondary vortices. Experiments were performed at the Reynolds number range of Re = 165–300. From these experiments, it can be concluded that mode C structures are formed as secondary streamwise vortices around the primary von Kármán vortices. The spanwise wavelength of those mode C structures is determined to be approximately two cylinder diameters. The presence of the wire also triggered the occurrence of period doubling in the wake. Each new set of mode C structures is out of phase with the previous set, i.e. doubling the shedding period. This period-doubling phenomenon is due to a feedback mechanism between the consecutively shed upper vortices.
Efficacy of the active middle-ear implant in patients with sensorineural hearing loss
Authors: Butler C L , Thavaneswaran P , Lee I H 
Published: June 2013

AbstractIntroduction:This systematic review aims to advise on the effectiveness of the active middle-ear implant in patients with sensorineural hearing loss, compared with external hearing aids.Methods:A systematic search of several electronic databases, including PubMed and Embase, was used to identify relevant studies for inclusion.Results:Fourteen comparative studies were included. Nine studies reported on the primary outcome of functional gain: one found that the middle-ear implant was significantly better than external hearing aids (p < 0.001), while another found that external hearing aids were generally significantly better than middle-ear implants (p < 0.05). Six of the seven remaining studies found that middle-ear implants were better than external hearing aids, although generally no clinically significant difference (i.e. ≥10 dB) was seen.Conclusion:Generally, the active middle-ear implant appears to be as effective as the external hearing aid in improving hearing outcomes in patients with sensorineural hearing loss.
Prediction plays a key role in language development as well as processing
Authors: Johnson Matt A. , Turk-Browne Nicholas B. , Goldberg Adele E. 
Published: June 2013

AbstractAlthough the target article emphasizes the important role of prediction in language use, prediction may well also play a key role in the initial formation of linguistic representations, that is, in language development. We outline the role of prediction in three relevant language-learning domains: transitional probabilities, statistical preemption, and construction learning.
The poor helping the rich: How can incomplete representations monitor complete ones?
Authors: Strijkers Kristof , Runnqvist Elin , Costa Albert , Holcomb Phillip 
Published: June 2013

AbstractPickering & Garrod (P&G) propose that inner speech monitoring is subserved by predictions stemming from fast forward modeling. In this commentary, we question this alignment of language prediction with the inner speech monitor. We wonder how the speech monitor can function so efficiently if it is based on incomplete representations.
What does it mean to predict one's own utterances?
Authors: Meyer Antje S. , Hagoort Peter 
Published: June 2013

AbstractMany authors have recently highlighted the importance of prediction for language comprehension. Pickering & Garrod (P&G) are the first to propose a central role for prediction in language production. This is an intriguing idea, but it is not clear what it means for speakers to predict their own utterances, and how prediction during production can be empirically distinguished from production proper.
Removing barriers to trade on environmental goods: an appraisal
Authors: BALINEAU GAËLLE , DE MELO JAIME 
Published: June 2013

AbstractThis paper reviews the extent of reductions in tariffs on environmental goods (EGs) by country participation in the negotiations mandated by a Doha Ministerial Decision in November 2001. Symptomatic of the cleavages across countries throughout the Round, little progress was achieved during the negotiations in defining an approach to a multilateral reduction in protection of EGs. Conflicting interests and differing perceptions of the benefits from increased trade in EGs was reflected in the different approaches proposed by members (request and offer, integrated project, list approach, hybrid approach), and for the few countries (13) that adopted a list approach, there was little overlap across submissions. For all income groups, on average, EGs are less protected than other goods and countries reduced protection by about 50% from initial levels in 1996 leaving little room for further exchange of market access. Difficulties in applying the two complementary conceptions of EGs: (i) ‘goods for environmental management’, and (ii) ‘environmentally preferable products' are reviewed and mentioned as reasons for the lack of progress during the negotiations. Inspection of the submission lists against a ‘core list’ of 26 EGs drawn up by the WTO shows that this ‘core list’ was mostly made up of products in which developed countries had a comparative advantage, and that countries that submitted lists generally avoided including on their lists the most highly protected goods.
A multi-criteria assessment of the production and marketing systems of local mountain food
Authors: Prišenk Jernej , Rozman Črtomir , Pažek Karmen , Turk Jernej , Bohak Zarja , Borec Andreja 
Published: June 2013

AbstractA multi-criteria model for a qualitative assessment of the production and marketing of local food products (LFP) from mountain areas has been developed by applying the DEX method. The development of the model was carried out and finally applied to ten local food products. The results were given in the form of a qualitative final assessment of both the production and marketing phases. By applying a plus–minus-1 analysis, the influence of various attributes on the final assessment of the LFP was examined. The main bottlenecks in the production and marketing processes were found. A sensitivity test was used to explain the influence of production and marketing on the final assessment. The results give clear directions as to which of the main attributes must be changed/improved or further developed to enable the successful promotion of local food products, which would give rise to an improved economy in mountain areas.
Decomposer communities in human‐impacted streams: species dominance rather than richness affects leaf decomposition
Authors: Tolkkinen Mikko , Mykrä Heikki , Markkola Anna‐Mari , Aisala Heidi , Vuori Kari‐Matti , Lumme Jaakko , Pirttilä Anna Maria , Muotka Timo 
Published: June 2013

SummaryThere is compelling evidence that anthropogenic disturbance can decrease biodiversity and impair ecological functioning. A major challenge to biodiversity–ecosystem function research is to disentangle the effects of biodiversity loss on ecosystem functions from the direct effects of human disturbance.We studied the influence of human disturbance (acidification and eutrophication) and a natural stressor (lowpHdue to bedrock geology) on leaf‐shredding macroinvertebrates, fungal decomposers and leaf decomposition rates in boreal streams. We used pyrosequencing techniques to determine fungal richness and assemblage structure.Decomposition rates were higher in anthropogenically disturbed than in circumneutral reference or naturally acidic sites, but did not differ between the latter two groups. Macroinvertebrate richness was higher in circumneutral than in human‐impacted or naturally acidic sites, and shredder evenness was highest in circumneutral sites. Fungal evenness was also lower in human‐disturbed than in reference sites, whereas fungal richness did not vary among site groups.Decomposition rate in fine‐mesh bags was related positively to current velocity and fungal dominance, while in coarse‐mesh bags, it was related positively to total phosphorus. In anthropogenically disturbed streams, the effects of lowpHwere overridden by eutrophication, and increased decomposition rates resulted from disturbance‐induced increase in species dominance rather than richness. Furthermore, decomposition rates were positively correlated with abundances of dominant taxa, suggesting that ecosystem processes may be driven by a few key species.Synthesis and applications. Our results suggest that leaf decomposition rates are insensitive to natural background variation, supporting the use of decomposition assays, preferably accompanied by molecular analysis of fungal assemblages, to assess stream ecosystem health. Instead of focusing solely on diversity, however, more emphasis should be placed at changes in dominance patterns, particularly if management aims are to improve stream ecosystem functioning.
Evidence for scale‐ and disturbance‐dependent trait assembly patterns in dry semi‐natural grasslands
Authors: de Bello Francesco , Vandewalle Marie , Reitalu Triin , Lepš Jan , Prentice Honor C. , Lavorel Sandra , Sykes Martin T. 
Published: June 2013

Summary

The mechanisms driving nonrandom assembly patterns in plant communities have long been of interest in ecological research. Competing ecological theories predict that coexisting species may either be more functionally dissimilar than expected by chance (with functional ‘divergence’ mainly reflecting niche differentiation) or be functionally more similar than expected (with functional ‘convergence’ reflecting either the outcome of environmental filtering or weaker‐competitor exclusion effects). Assembly patterns are usually assessed at a single scale and disturbance regime, whereas considering different spatial scales and disturbance regimes may clarify the underlying assembly mechanisms.

We tested the prediction that convergence and divergence are scale‐ and disturbance‐ dependent in grazed and abandoned species‐rich dry grasslands within a 22 km2 landscape in south‐eastern Sweden. Convergence and divergence were tested for plant species' traits and phylogenetic relationships at three nested spatial scales: within 412 plots (50 × 50 cm, divided into 10 × 10 cm subplots), within 117 grassland patches (from 0.02 to 11.63 ha) and within the whole landscape (across patches).

At the finest scale (10 × 10 cm subplots within plots), coexisting species were more different than expected by chance (divergence), both functionally and phylogenetically, suggesting niche differentiation. At the intermediate scale (50 × 50 cm plots within patches), coexisting species showed convergence, suggesting environmental filtering. No significant deviations from random expectations were detected at the broadest scale (patches within the 22 km2 landscape) – suggesting the prevalence of dispersal limitation at this scale. The fact that nonrandom patterns were particularly evident under grazed conditions is consistent with the prediction that assembly patterns are disturbance dependent.

Synthesis. This study shows that multiple trait‐based assembly processes operate simultaneously in species‐rich communities, across spatial scales and disturbance regimes. The results support earlier theoretical predictions that divergence between coexisting species may be an important driver of community assembly, particularly at finer spatial scales, where species compete for the same local resources. In contrast, environmental filtering is expected at broader spatial scales, where species growing in particular environmental conditions share traits that are adaptive under those conditions. Within given habitat types, dispersal limitation may, however, override environmental filtering at increasing spatial scales of observation.
Re‐examination of production, cost, and restricted profit functions using quantile regression approach
Authors: Shaik Saleem 
Published: June 2013

AbstractThis article estimates quantile regressions of production, cost, and restricted profit functions using a Cobb‐Douglas functional form with non‐Hicks neutral technology change. In contrast to previous studies, quantile regression estimates reveal the relationship between the independent (production, cost, and restricted profit) and dependent (input quantities and prices) variables at each quantile of the distribution. An empirical application using data from 48 states in United States from 1960 to 2004 indicates the returns to scale and aggregate technology not only differ across production, cost, and restricted profit functions but across states in different quantiles of the distribution. This suggests the traditional measures of returns to scale and aggregate technology are under‐ and overestimated in states at upper and lower quantiles, respectively.
Extent and possible causes of intrayear agricultural commodity price volatility
Authors: Ott Hervé 
Published: June 2013

AbstractWheat, corn, rice, soybeans, and cotton experienced higher volatility in the second half of the 2000s. For the sample at hand, the unit root tests only validate a new period of high volatility for wheat and cotton. If in the next couple of years however, corn, rice and soybeans maintain their higher volatility, a new period of high volatility may also be validated statistically. Regarding the factors driving the intrayear volatility GMM estimates show that “commodity market fundamentals” i.e., the stock‐to‐use ratio and to a lesser extent the degree of internationalization, are the most systematically statistically significant coefficients among commodities. Over time, consecutive low stock‐to‐use ratios and a thin international market provoke typically high volatility. Speculative activity and liquidity in the agricultural derivative market have a stabilizing effect on the spot price, if any. Finally, “common macro” factors significantly impact volatility, especially the volatility of petrol and of exchange rates; their dispersion importance over the sample is quite sizeable. However, it is difficult to establish a link between, on the one hand, loose monetary policy, business cycle and inflation, and, on the other hand, commodity price volatility, as the sign of the estimated coefficient changes depending on the commodity and the estimated elasticities are quite low.