bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compound‐specific δ13C analysis of monosaccharides from soil extracts by high‐performance liquid chromatography/isotope ratio mass spectrometry
Authors: Basler A. , Dyckmans J. 
Published: October 2013

RATIONALECarbohydrates represent up to 25% of soil organic matter and derive from fresh plant input or organic matter transformation within the soil. Compound‐specific isotope analysis (CSIA) of monosaccharides (sugars) extracted from soil provides a powerful tool to disentangle the dynamics of different carbohydrate pools of soils. The use of high‐performance liquid chromatography/oxidation/isotope ratio mass spectrometry (HPLC/o/IRMS) allows isotope measurements without the need for derivatisation and thus increasing accuracy and precision of the isotopic measurement, compared with gas chromatography/combustion/isotope ratio mass spectrometry (GC/c/IRMS).METHODSThe CSIA of soil carbohydrates was performed using a HPLC/o/IRMS system. The chromatographic and mass spectrometric subunits were coupled with a LC–Isolink interface. Soil sugars were extracted after mild hydrolysis using 4 M trifluoroacetic acid (TFA). Chromatographic separation of the sugars was achieved using a low strength 0.25 mM NaOH solution as mobile phase at a flow rate of 250 μL min–1 at 10 °C.RESULTSThe chromatographic conditions allowed the baseline separation of the seven most abundant sugars in soil. Complete removal of TFA from the soil hydrolysate ensured chromatographic stability. The accuracy was better than 0.66 ‰ for amounts of >2.5 nM sugar on column. The sugars extracted from an agricultural soil appeared to be more enriched in 13C than the soil organic carbon, and to have a similar isotopic signature to the soil microbial biomass.CONCLUSIONSThe proposed method proved to be suitable for the analysis of the common sugars in soil extracts and represents a precise tool for the study of carbohydrate dynamics. Copyright © 2013 John Wiley & Sons, Ltd.
Additive‐state‐decomposition‐based tracking control framework for a class of nonminimum phase systems with measurable nonlinearities and unknown disturbances
Authors: Quan Quan , Cai Kai‐Yuan , Lin Hai 
Published: October 2013

SUMMARYThis paper aims to propose an additive‐state‐decomposition‐based tracking control framework, based on which the output feedback tracking problem is solved for a class of nonminimum phase systems with measurable nonlinearities and unknown disturbances. This framework is to ‘additively’ decompose the output feedback tracking problem into two more tractable problems, namely an output feedback tracking problem for a linear time invariant system and a state feedback stabilization problem for a nonlinear system. Then, one can design a controller for each problem respectively using existing methods, and these two designed controllers are combined together to achieve the original control goal. The main contribution of the paper lies on the introduction of an additive state decomposition scheme and its implementation to mitigate the design difficulty of the output feedback tracking control problem for nonminimum phase nonlinear systems. To demonstrate the effectiveness, an illustrative example is given. Copyright © 2013 John Wiley & Sons, Ltd.
Bounded consensus tracking for sampled‐data second‐order multi‐agent systems with fixed and Markovian switching topology
Authors: Xie Dongmei , Cheng Yongli 
Published: October 2013

SUMMARYThis paper studies the bounded consensus tracking problems of second‐order multi‐agent systems with fixed and Markovian switching topology in a sampling setting. It is assumed that all the agents can only obtain the approximative value of the leader's acceleration instead of the actual value. Moreover, only a portion of agents can have the access to the leader and obtain the leader's position and velocity directly. By virtue of matrix analysis and perturbation theory, we present necessary and sufficient conditions for boundedness of tracking error system and show the ultimate bound of tracking errors under fixed and Markovian switching topology, respectively. Finally, a simulation example is given to illustrate the effectiveness of the results. Copyright © 2013 John Wiley & Sons, Ltd.
Precise modeling of aging populations
Authors: Eberlein Robert L. , Thompson James P. 
Published: October 2013

AbstractAggregate continuous time formulations used in system dynamics models result in the implicit mixing of individual constituents of levels. Normally, this is acceptable as the heterogeneous nature of model variables implies that some individuals counted in a level's value will pass others and exit earlier. In models with a focus on chronological aging and age‐related characteristics, this phenomenon, which we call cohort blending, can result in large distortions. Using aging chains can reduce these distortions, but cohort blending persists even with one‐year groupings. As an alternative, we introduce an approach we call “continuous cohorting” in which populations are tracked with cohorts sized the same as the computational interval of the model. This approach eliminates the blending problem with minimal notational and moderate computational burden. The resulting models display quantitative, though limited qualitative, differences from their traditional counterparts and are more easily defensible with demographers and others who study population dynamics. Copyright © 2013 System Dynamics Society
Hidden attribute‐based signcryption scheme for lattice
Authors: Xiang Xinyin , Li Hui , Wang Mingyu , Liu Zhenhua 
Published: October 2013

ABSTRACTAs a novel cryptographic primitive, signcryption realizes the function of digital signature and public‐key encryption simultaneously, at a cost significantly lower than that of the traditional sign‐then‐encrypt approach. To the best of the authors’ knowledge, there is little works focusing on attribute‐based signcryption (ABSC), especially in the setting of lattice‐based cryptography. In this paper, we show that it is possible to construct hidden ABSC schemes based on lattice problems by presenting an ABSC scheme. In the random oracle model, the proposed scheme is proved to be indistinguishable against adaptively chosen ciphertext attacks under the learning with errors assumption and existentially unforgeable against adaptively chosen message attacks under the short integer solution assumption, respectively. Copyright © 2013 John Wiley & Sons, Ltd.
Variance reduction in randomised trials by inverse probability weighting using the propensity score
Authors: Williamson Elizabeth J. , Forbes Andrew , White Ian R. 
Published: October 2013

AbstractIn individually randomised controlled trials, adjustment for baseline characteristics is often undertaken to increase precision of the treatment effect estimate. This is usually performed using covariate adjustment in outcome regression models. An alternative method of adjustment is to use inverse probability‐of‐treatment weighting (IPTW), on the basis of estimated propensity scores. We calculate the large‐sample marginal variance of IPTW estimators of the mean difference for continuous outcomes, and risk difference, risk ratio or odds ratio for binary outcomes. We show that IPTW adjustment always increases the precision of the treatment effect estimate. For continuous outcomes, we demonstrate that the IPTW estimator has the same large‐sample marginal variance as the standard analysis of covariance estimator. However, ignoring the estimation of the propensity score in the calculation of the variance leads to the erroneous conclusion that the IPTW treatment effect estimator has the same variance as an unadjusted estimator; thus, it is important to use a variance estimator that correctly takes into account the estimation of the propensity score. The IPTW approach has particular advantages when estimating risk differences or risk ratios. In this case, non‐convergence of covariate‐adjusted outcome regression models frequently occurs. Such problems can be circumvented by using the IPTW adjustment approach. © 2013 The authors. Statistics in Medicine published by John Wiley & Sons, Ltd.
Creating Technological Boundaries to Protect Bedtime: Examining Work–Home Boundary Management, Psychological Detachment and Sleep
Authors: Barber Larissa K. , Jenkins Jade S. 
Published: October 2013

AbstractThis study examined the mechanism by which information and communication technology (ICT) use at home for work purposes may affect sleep. In this investigation, data from 315 employees were used to examine the indirect effect of ICT use at home on sleep outcomes through psychological detachment, and how boundary creation may moderate this effect. Results revealed the indirect effect of increased work–home boundary crossing on sleep (quantity, quality and consistency) through psychological detachment occurred only among individuals with low boundaries around ICT use and not among those with high boundaries. These results suggest that creating boundaries around work‐relevant ICT use while at home is beneficial to sleep as a recovery process through being able to psychologically disengage from work. Copyright © 2013 John Wiley & Sons, Ltd.
Comparing text‐based and dependence‐based approaches for determining the origins of bugs
Authors: Davies Steven , Roper Marc , Wood Murray 
Published: October 2013

SUMMARYIdentifying bug origins – the point where erroneous code was introduced – is crucial for many software engineering activities, from identifying process weaknesses to gathering data to support bug detection tools. Unfortunately, this information is not usually recorded when fixing bugs, and recovering it later is challenging. Recently, the text approach and the dependence approach have been developed to tackle this problem. Respectively, they examine textual and dependence‐related changes that occurred prior to a bug fix. However, only limited evaluation has been carried out, partially because of a lack of available implementations and of datasets linking bugs to origins. To address this, origins of 174 bugs in three projects were manually identified and compared to a simulation of the approaches. Both approaches were partially successful across a variety of bugs – achieving 29–79% precision and 40–70% recall. Results suggested the precise definition of program dependence could affect performance, as could whether the approaches identified a single or multiple origins. Some potential improvements are explored in detail and identify pragmatic strategies for combining techniques along with simple modifications. Even after adopting these improvements, there remain many challenges: large commits, unrelated changes and long periods between origins and fixes all reduce effectiveness. Copyright © 2013 John Wiley & Sons, Ltd.
FaultTracer: a spectrum‐based approach to localizing failure‐inducing program edits
Authors: Zhang Lingming , Kim Miryung , Khurshid Sarfraz 
Published: October 2013

SUMMARYDetecting faults in evolving systems is important. Change impact analysis has been shown to be effective for finding faults during software evolution. For example, Chianti represents program edits as atomic changes, selects affected tests, and determines a subset of affecting changes that might have caused test failures. However, the number of affecting changes related to each test failure in practice may still be overwhelming for manual inspection. In this paper, we present a novel approach, FaultTracer, which ranks program edits according to their suspiciousness to reduce developer effort in manually inspecting affecting changes. FaultTracer adapts spectrum‐based fault localization techniques, which assume the statements that are primarily executed by failed tests are more suspicious, and applies them in tandem with an enhanced change impact analysis to identify failure‐inducing edits more precisely. We conducted an experimental study using 23 real versions of four real‐world Java programs from the Software Infrastructure Repository. The experimental results show that FaultTracer localizes a real regression fault within top three atomic changes for 14 out of 22 studied real failures. When ranking only method‐level changes, compared to the existing ranking heuristic, FaultTracer reduces the number of changes to be manually inspected by more than 50% on the data set of real regression faults, and by more than 60% on the data set of seeded faults. The fault localization component of FaultTracer is 80% more effective than traditional spectrum‐based fault localization, and enables similar benefits when using either our enhanced change impact analysis or Chianti. The runtime overhead for FaultTracer to collect extended call graphs is 49.83 s for each subject on average and is only 8.26% more than that for Chianti to collect traditional call graph information. Copyright © 2013 John Wiley & Sons, Ltd.
A conceptual framework for SPI evaluation
Authors: Unterkalmsteiner Michael , Gorschek Tony , Islam A. K. M. Moinul , Cheng Chow Kian , Permadi Rahadian Bayu , Feldt Robert 
Published: October 2013

SUMMARYSoftware Process Improvement (SPI) encompasses the analysis and modification of the processes within software development, aimed at improving key areas that contribute to the organizations' goals. The task of evaluating whether the selected improvement path meets these goals is challenging. On the basis of the results of a systematic literature review on SPI measurement and evaluation practices, we developed a framework (SPI Measurement and Evaluation Framework (SPI‐MEF)) that supports the planning and implementation of SPI evaluations. SPI‐MEF guides the practitioner in scoping the evaluation, determining measures, and performing the assessment. SPI‐MEF does not assume a specific approach to process improvement and can be integrated in existing measurement programs, refocusing the assessment on evaluating the improvement initiative's outcome. Sixteen industry and academic experts evaluated the framework's usability and capability to support practitioners, providing additional insights that were integrated in the application guidelines of the framework. Copyright © 2013 John Wiley & Sons, Ltd.
Rethinking Systems Thinking: Learning and Coevolving with the World
Authors: Ing David 
Published: October 2013

Much of systems thinking, as commonly espoused today, was developed by a generation in the context of the 1950s–1980s. In the 2010s, has systems thinking changed with the world in which it is to be applied? Is systems thinking learning and coevolving with the world? Some contemporary systems thinkers continue to push the frontiers of theory, methods and practice. Others situationally increment the traditions of their preferred gurus, where approaches proven successful in prior experiences are replicated for new circumstances. Founded on interactions with a variety of systems communities over the past 15 years, three ways to rethink systems thinking are proposed:

‘parts and wholes’ snapshots → ‘learning and coevolving’ over time
social and ecological → emerged environments of the service economy and the Anthropocene
episteme and techne → phronesis for the living and nonlivingThese proposed ways are neither exhaustive nor sufficient. The degree to which systems thinking should be rethought may itself be controversial. If, however, systems thinking is to be authentic, the changed world of the 21st century should lead systems thinkers to engage in a reflective inquiry. Copyright © 2013 John Wiley & Sons, Ltd.
Inhibition of EGFR Induces a c-MET-Driven Stem Cell Population in Glioblastoma
Authors: Jun Hyun Jung , Bronson Roderick T. , Charest Alain 
Published: October 2013

Abstract
Glioblastoma multiforme (GBM) is the most lethal form of primary brain tumors, characterized by highly invasive and aggressive tumors that are resistant to all current therapeutic options. GBMs are highly heterogeneous in nature and contain a small but highly tumorigenic and self-renewing population of stem or initiating cells (glioblastoma stem cells or GSCs). GSCs have been shown to contribute to tumor propagation and resistance to current therapeutic modalities. Recent studies of human GBMs have elucidated the genetic alterations common in these tumors, but much remains unknown about specific signaling pathways that regulate GSCs. Here we identify a distinct fraction of cells in a genetically engineered mouse model of EGFR-driven GBM that respond to anti-EGFR therapy by inducing high levels of c-MET expression. The MET-positive cells displayed clonogenic potential and long-term self-renewal ability in vitro and are capable of differentiating into multiple lineages. The MET-positive GBM cells are resistant to radiation and highly tumorigenic in vivo. Activation of MET signaling led to an increase in expression of the stemness transcriptional regulators Oct4, Nanog, and Klf4. Pharmacological inhibition of MET activity in GSCs prevented the activation of Oct4, Nanog, and Klf4 and potently abrogated stemness. Finally, the MET expressing cells were preferentially localized in perivascular regions of mouse tumors consistent with their function as GSCs. Together, our findings indicate that EGFR inhibition in GBM induces MET activation in GSCs, which is a functional requisite for GSCs activity and thus represents a promising therapeutic target. Stem Cells 2014;32:338–348
CCAAT/Enhancer-Binding ProteinβExpressed by Bone Marrow Mesenchymal Stromal Cells Regulates Early B-Cell Lymphopoiesis
Authors: Yoshioka Satoshi , Miura Yasuo , Yao Hisayuki , Satake Sakiko , Hayashi Yoshihiro , Tamura Akihiro , Hishita Terutoshi , Ichinohe Tatsuo , Hirai Hideyo , Takaor-Kondo Akifumi , Maekawa Taira 
Published: October 2013

AbstractThe transcription factor CCAAT/enhancer-binding protein β (C/EBPβ) regulates the differentiation of a variety of cell types. Here, the role of C/EBPβ expressed by bone marrow mesenchymal stromal cells (BMMSCs) in B-cell lymphopoiesis was examined. The size of the precursor B-cell population in bone marrow was reduced in C/EBPβ-knockout (KO) mice. When bone marrow cells from C/EBPβ-KO mice were transplanted into lethally irradiated wild-type (WT) mice, which provide a normal bone marrow microenvironment, the size of the precursor B-cell population was restored to a level equivalent to that generated by WT bone marrow cells. In coculture experiments, BMMSCs from C/EBPβ-KO mice did not support the differentiation of WT c-Kit+ Sca-1+ Lineage− hematopoietic stem cells (KSL cells) into precursor B cells, whereas BMMSCs from WT mice did. The impaired differentiation of KSL cells correlated with the reduced production of CXCL12/stromal cell-derived factor-1 by the cocultured C/EBPβ-deficient BMMSCs. The ability of C/EBPβ-deficient BMMSCs to undergo osteogenic and adipogenic differentiation was also defective. The survival of leukemic precursor B cells was poorer when they were cocultured with C/EBPβ-deficient BMMSCs than when they were cocultured with WT BMMSCs. These results indicate that C/EBPβ expressed by BMMSCs plays a crucial role in early B-cell lymphopoiesis. Stem Cells 2014;32:730–740
Spontaneous Reactivation of Clusters of X-Linked Genes Is Associated with the Plasticity of X-Inactivation in Mouse Trophoblast Stem Cells
Authors: Dubois Agnès , Deuve Jane Lynda , Navarro Pablo , Merzouk Sarra , Pichard Sylvain , Commere Pierre-Henri , Louise Anne , Arnaud Danielle , Avner Philip , Morey Céline 
Published: October 2013

Abstract
Random epigenetic silencing of the X-chromosome in somatic tissues of female mammals equalizes the dosage of X-linked genes between the sexes. Unlike this form of X-inactivation that is essentially irreversible, the imprinted inactivation of the paternal X, which characterizes mouse extra-embryonic tissues, appears highly unstable in the trophoblast giant cells of the placenta. Here, we wished to determine whether such instability is already present in placental progenitor cells prior to differentiation toward lineage-specific cell types. To this end, we analyzed the behavior of a GFP transgene on the paternal X both in vivo and in trophoblast stem (TS) cells derived from the trophectoderm of XXGFP blastocysts. Using single-cell studies, we show that not only the GFP transgene but also a large number of endogenous genes on the paternal X are subject to orchestrated cycles of reactivation/de novo inactivation in placental progenitor cells. This reversal of silencing is associated with local losses of histone H3 lysine 27 trimethylation extending over several adjacent genes and with the topological relocation of the hypomethylated loci outside of the nuclear compartment of the inactive X. The “reactivated” state is maintained through several cell divisions. Our study suggests that this type of “metastable epigenetic” states may underlie the plasticity of TS cells and predispose specific genes to relaxed regulation in specific subtypes of placental cells. Stem Cells 2014;32:377–390
Nanotubular Crosstalk with Distressed Cardiomyocytes Stimulates the Paracrine Repair Function of Mesenchymal Stem Cells
Authors: Figeac Florence , Lesault Pierre-François , Coz Olivier , Damy Thibaud , Souktani Richard , Trébeau Céline , Schmitt Alain , Ribot Jonathan , Mounier Rémi , Guguin Aurélie , Manier Céline , Surenaud Mathieu , Hittinger Luc , Dubois-Randé Jean-Luc , Rodriguez Anne-Marie 
Published: October 2013

Abstract
Mesenchymal stem cells (MSC) are known to repair broken heart tissues primarily through a paracrine fashion while emerging evidence indicate that MSC can communicate with cardiomyocytes (CM) through tunneling nanotubes (TNT). Nevertheless, no link has been so far established between these two processes. Here, we addressed whether cell-to-cell communication processes between MSC and suffering cardiomyocytes and more particularly those involving TNT control the MSC paracrine regenerative function. In the attempt to mimic in vitro an injured heart microenvironment, we developed a species mismatch coculture system consisting of terminally differentiated CM from mouse in a distressed state and human multipotent adipose derived stem cells (hMADS). In this setting, we found that crosstalk between hMADS and CM through TNT altered the secretion by hMADS of cardioprotective soluble factors such as VEGF, HGF, SDF-1α, and MCP-3 and thereby maximized the capacity of stem cells to promote angiogenesis and chemotaxis of bone marrow multipotent cells. Additionally, engraftment experiments into mouse infarcted hearts revealed that in vitro preconditioning of hMADS with cardiomyocytes increased the cell therapy efficacy of naïve stem cells. In particular, in comparison with hearts treated with stem cells alone, those treated with cocultured ones exhibited greater cardiac function recovery associated with higher angiogenesis and homing of bone marrow progenitor cells at the infarction site. In conclusion, our findings established the first relationship between the paracrine regenerative action of MSC and the nanotubular crosstalk with CM and emphasize that ex vivo manipulation of these communication processes might be of interest for optimizing current cardiac cell therapies. Stem Cells 2014;32:216–230