bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two‐way coupling in reservoir–geomechanical models: vertex‐centered Galerkin geomechanical model cell‐centered and vertex‐centered finite volume reservoir models
Authors: Prevost Jean H. 
Published: March 2014

SUMMARYProcedures to couple reservoir and geomechanical models are reviewed. The focus is on immiscible compressible non‐compositional reservoir–geomechanical models. Such models require the solution to: coupled stress, pressure, saturation and temperature equations. Although the couplings between saturation and temperature with stress and fluid pressure are ‘weak’ and can be adequately captured thru staggered (fixed point) iterations, the couplings between stress and pressure are ‘strong’ and require special procedures for accurate integration. As shown and discussed in detail in our previous works, two‐way coupling (i.e., simultaneous integration) of pressure and stress equations is required if poromechanical effects are to be captured accurately. In our previous work, a Galerkin implementation of both pressure and stress equations was used with equal order interpolants.However, most (if not all) reservoir simulators use a finite volume implementation of the pressure equation. Therefore, there remain important unanswered questions related to the interface between a Galerkin vertex‐centered geomechanical model with a reservoir finite volume model as such an implementation has never been attempted before. We address those issues in the following by studying the interface with both a cell‐centered and a vertex‐centered finite volume implementation of the pressure equation. Central to the success of the implementation is the computation of the Jacobian matrix. The elemental contribution to the coupling Jacobian matrix is computed through numerical finite differencing of the residuals. The procedure is detailed herein. In the following, in order to attempt to clear confusion, the simplest case of an isothermal fully saturated, slightly compressible system is presented in detail, and the various solution strategies, simplifications and shortcomings are identified. Copyright © 2014 John Wiley & Sons, Ltd.
Effect of Caffeinated Versus Noncaffeinated Energy Drinks on Central Blood Pressures
Authors: Phan Jennifer K. , Shah Sachin A. 
Published: March 2014

Study ObjectiveTo evaluate the effects of caffeinated energy shots compared with noncaffeinated energy shots as assessed by changes in peripheral and central hemodynamic parameters in healthy subjects.DesignRandomized, double‐blind, controlled crossover study.SettingUniversity campus.PatientsTen healthy volunteers.Measurements and Main ResultsSubjects were randomized to receive either a caffeinated or noncaffeinated energy shot; after a minimum 6 days washout period, subjects were given the alternate energy shot. Peripheral blood pressures, and central hemodynamic parameters, were assessed and recorded for each subject at baseline and at 1 and 3 hours after consumption of the energy shots. Peripheral systolic blood pressure (SBP) increased significantly with the caffeinated energy shot compared with noncaffeinated (8.30 ± 4.19 mm Hg and −0.20 ± 5.55, respectively, p=0.009) at 3 hours. Central SBP increased significantly with the caffeinated energy shot compared with noncaffeinated (8.00 ± 4.03 mm Hg and 1.50 ± 6.57, respectively, p=0.045) at 3 hours. Peripheral and central diastolic blood pressure were nonsignificantly higher with the caffeinated energy shot at 3 hours. Peripheral and central pulse pressure were consistently higher with consumption of the caffeinated beverage. Heart rate, augmentation index, pulse pressure amplification ratio, ejection duration and Subendocardial Viability Ratio were not different between the two interventions over time. P1 height was significantly higher with the caffeinated shot compared with the noncaffeinated shot at both 1 and 3 hours (p=0.035 and 0.013, respectively). Three and one subjects experienced an adverse effect with the caffeinated and noncaffeinated shot, respectively.ConclusionA caffeinated energy shot acutely increases peripheral and central SBPs compared with a noncaffeinated energy shot. Larger studies with a placebo comparator are needed to assess the significance of peripheral and central hemodynamic changes with noncaffeinated energy drinks.
Microwave Plasma Process for SiCN:H Thin Films Synthesis with Composition Varying from SiC:H to SiN:H in H2/N2/Ar/Hexamethyldisilazane Gas Mixture
Authors: Belmahi Mohammed , Bulou Simon , Thouvenin Amanda , de Poucques Ludovic , Hugon Robert , Le Brizoual Laurent , Miska Patrice , Genève Damien , Vasseur Jean‐Luc , Bougdira Jamal 
Published: March 2014

AbstractSiCxNy:H thin films are obtained with the microwave plasma assisted chemical vapour deposition (MPACVD) method in the gas mixture H2/Ar/Hexamethyldisilazane. When very few amounts of nitrogen are added to the gas mixture, the film composition changes drastically from SiCx:H like films to SiNx:H like films, according to X‐rays Photoelectron Spectroscopy and Fourier Transform Infra‐Red Spectroscopy (FTIR) analysis. The refractive index (n) and Tauc's optical gap (Eg) are modified over a wide range of values (1.75 ≤ n ≤ 2.15 and 3.5 eV ≤ Eg ≤ 5 eV) with nitrogen addition to the feed gas leading to thin films optical constants close to those of SiC or Si3N4. Therefore, for the films obtained without nitrogen, SiC nanoparticles with a size of about 20 nm embedded in an amorphous SiCN:H matrix are synthesized, leading to nanocomposite films.
Optical detection of nonradiative recombination centers in AlGaN quantum wells for deep UV region
Authors: Touhidul Islam A. Z. M. , Murakoshi N. , Fukuda T. , Hirayama H. , Kamata N. 
Published: March 2014

AbstractBy superposing a chopped below‐gap excitation (BGE) light on a cw above‐gap excitation and observing the intensity change of photoluminescence (PL) due to the BGE, we clarified a distribution of nonradiative recombination (NRR) centers in AlGaN multi‐quantum well (MQW) structures for the wavelength region of deep ultraviolet (UV). The decrease in band‐edge PL peak intensity at 10 K exemplified the presence of a pair of NRR centers in AlGaN well layers whose transition energy corresponds to that of the BGE. The BGE power dependence of the normalized PL intensity showed a quenching saturation due to trap‐filling effect of electrons in one of the centers which were activated by the BGE. The BGE energy dependence of the normalized PL intensity revealed that the optical activation energy of the dominant NRR process via these trap states in the AlGaN MQW is around 1.17 eV. The purely optical scheme of detection enables us to obtain clues for identifying defect levels in DUV region and eliminating them during growth process without any preparation of electrodes. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Strain states in GaN films grown on Si(111) and Si(110) substrates using a thin AlN/GaN superlattice interlayer
Authors: Shen X. Q. , Takahashi T. , Ide T. , Shimizu M. 
Published: March 2014

AbstractWe report the characterization results of the strain states in GaN films grown both on Si(111) and Si(110) substrates by applying a thin AlN/GaN superlattice structure (SLs) as an interlayer (IL). The strain states in the GaN films grown on Si(111) and Si(110) substrates are compared. It is demonstrated that the modulation effect by the SL ILs on the strain state in the GaN film is universal although different behaviours on the Si(111) and Si(110) substrate are observed due to the different lattice symmetry relationship between the substrate and the epilayer. By using the technique, we succeeded in growing thick continuous GaN films (> 3 µm), which are necessary for the high‐power, high‐voltage device applications. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fourier transform infrared spectroscopy analysis of thin boron nitride films prepared by ion beam assisted deposition
Authors: Matsuoka Masao , Langhi Mauro P. , Isotani Sadao , Chubaci José F. D. 
Published: March 2014

AbstractThin boron nitride (BN) films were synthesized by ion beam assisted deposition (IBAD). From Fourier transform infrared spectroscopy (FTIR) analysis results, it was found that: the films with the co‐presence of explosion‐phase BN (E‐BN) and sp2‐bonded hexagonal BN (h‐BN), and those with pure h‐BN were formed in the respective substrate temperature regions of 20–85 °C and 350–400 °C, under nitrogen ion irradiation (ion energy from 500 to 1000 eV), while the substrate temperature at 400 °C and mixed nitrogen and argon ion irradiation were necessary for the formation of sp3‐bonded cubic BN (c‐BN). To our knowledge, the E‐BN phase was formed firstly by IBAD in this study. The crystalline phase identification through the FTIR results was in line with X‐ray diffraction results. The shift of the c‐BN peak position is usually attributed to remaining compressive stress in the film. In this work, the downward shift of the c‐BN peak position and the broadening of the c‐BN peak, which were observed when the film thickness increased, can be interpreted using a phenomenological description of structural disordering in the c‐BN sites. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Projected Risk of Population Declines for Native Fish Species in the Upper Mississippi River
Authors: Crimmins S. M. , Boma P. , Thogmartin W. E. 
Published: March 2014

SummaryConservationists are in need of objective metrics for prioritizing the management of habitats. For individual species, the threat of extinction is often used to prioritize what species are in need of conservation action. Using long‐term monitoring data, we applied a Bayesian diffusion approximation to estimate quasi‐extinction risk for 54 native fish species within six commercial navigation reaches along a 1350‐km gradient of the upper Mississippi River system. We found a strong negative linear relationship between quasi‐extinction risk and distance upstream. For some species, quasi‐extinction estimates ranged from nearly zero in some reaches to one in others, suggesting substantial variability in threats facing individual river reaches. We found no evidence that species traits affected quasi‐extinction risk across the entire system. Our results indicate that fishes within the upper Mississippi River system face localized threats that vary across river impact gradients. This suggests that conservation actions should be focused on local habitat scales but should also consider the additive effects on downstream conditions. We also emphasize the need for identification of proximate mechanisms behind observed and predicted population declines, as conservation actions will require mitigation of such mechanisms. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
Concise Review: Fragile X Proteins in Stem Cell Maintenance and Differentiation
Authors: Li Yue , Zhao Xinyu 
Published: March 2014

AbstractFragile X syndrome (FXS), the most common genetic form of autism spectrum disorder, is caused by deficiency of the fragile X mental retardation protein (FMRP). Despite extensive research and scientific progress, understanding how FMRP regulates brain development and function remains a major challenge. FMRP is a neuronal RNA-binding protein that binds about a third of messenger RNAs in the brain and controls their translation, stability, and cellular localization. The absence of FMRP results in increased protein synthesis, leading to enhanced signaling in a number of intracellular pathways, including the mTOR, mGLuR5, ERK, Gsk3β, PI3K, and insulin pathways. Until recently, FXS was largely considered a deficit of mature neurons; however, a number of new studies have shown that FMRP may also play important roles in stem cells, among them neural stem cells, germline stem cells, and pluripotent stem cells. In this review, we will cover these newly discovered functions of FMRP, as well as the other two fragile X-related proteins, in stem cells. We will also discuss the literature on the use of stem cells, particularly neural stem cells and induced pluripotent stem cells, as model systems for studying the functions of FMRP in neuronal development. Stem Cells 2014;32:1724–1733
miR-335 Correlates with Senescence/Aging in Human Mesenchymal Stem Cells and Inhibits Their Therapeutic Actions Through Inhibition of AP-1 Activity
Authors: Tomé María , Sepúlveda Juan Carlos , Delgado Mario , Andrades José A. , Campisi Judith , González, Manuel A. , Bernad Antonio 
Published: March 2014

Abstract
MicroRNAs, small noncoding RNAs, regulate gene expression primarily at the posttranscriptional level. We previously found that miR-335 is critically involved in the regulation and differentiation capacity of human mesenchymal stem cells (hMSCs) in vitro. In this study, we investigated the significance of miR-335 for the therapeutic potential of hMSCs. Analysis of hMSCs in ex vivo culture demonstrated a significant and progressive increase in miR-335 that is prevented by telomerase. Expression levels of miR-335 were also positively correlated with donor age of hMSCs, and were increased by stimuli that induce cell senescence, such as γ-irradiation and standard O2 concentration. Forced expression of miR-335 resulted in early senescence-like alterations in hMSCs, including: increased SA-β-gal activity and cell size, reduced cell proliferation capacity, augmented levels of p16 protein, and the development of a senescence-associated secretory phenotype. Furthermore, overexpression of miR-335 abolished the in vivo chondro-osseous potential of hMSCs, and disabled their immunomodulatory capacity in a murine experimental model of lethal endotoxemia. These effects were accompanied by a severely reduced capacity for cell migration in response to proinflammatory signals and a marked reduction in Protein Kinase D1 phosphorylation, resulting in a pronounced decrease of AP-1 activity. Our results demonstrate that miR-335 plays a key role in the regulation of reparative activities of hMSCs and suggests that it might be considered a marker for the therapeutic potency of these cells in clinical applications. Stem Cells 2014;32:2229–2244
Gremlin 2 Promotes Differentiation of Embryonic Stem Cells to Atrial Fate by Activation of the JNK Signaling Pathway
Authors: Tanwar Vineeta , Bylund Jeffery B. , Hu Jianyong , Yan Jingbo , Walthall Joel M. , Mukherjee Amrita , Heaton William H. , Wang Wen-Der , Potet Franck , Rai Meena , Kupershmidt Sabina , Knapik Ela W. , Hatzopoulos Antonis K. 
Published: March 2014

Abstract
The bone morphogenetic protein antagonist Gremlin 2 (Grem2) is required for atrial differentiation and establishment of cardiac rhythm during embryonic development. A human Grem2 variant has been associated with familial atrial fibrillation, suggesting that abnormal Grem2 activity causes arrhythmias. However, it is not known how Grem2 integrates into signaling pathways to direct atrial cardiomyocyte differentiation. Here, we demonstrate that Grem2 expression is induced concurrently with the emergence of cardiovascular progenitor cells during differentiation of mouse embryonic stem cells (ESCs). Grem2 exposure enhances the cardiogenic potential of ESCs by 20–120-fold, preferentially inducing genes expressed in atrial myocytes such as Myl7, Nppa, and Sarcolipin. We show that Grem2 acts upstream to upregulate proatrial transcription factors CoupTFII and Hey1 and downregulate atrial fate repressors Irx4 and Hey2. The molecular phenotype of Grem2-induced atrial cardiomyocytes was further supported by induction of ion channels encoded by Kcnj3, Kcnj5, and Cacna1d genes and establishment of atrial-like action potentials shown by electrophysiological recordings. We show that promotion of atrial-like cardiomyocytes is specific to the Gremlin subfamily of BMP antagonists. Grem2 proatrial differentiation activity is conveyed by noncanonical BMP signaling through phosphorylation of JNK and can be reversed by specific JNK inhibitors, but not by dorsomorphin, an inhibitor of canonical BMP signaling. Taken together, our data provide novel mechanistic insights into atrial cardiomyocyte differentiation from pluripotent stem cells and will assist the development of future approaches to study and treat arrhythmias. Stem Cells 2014;32:1774–1788
Coactivators p300 and CBP Maintain the Identity of Mouse Embryonic Stem Cells by Mediating Long-Range Chromatin Structure
Authors: Fang Fang , Xu Yifeng , Chew Kai-Khen , Chen Xi , Ng Huck-Hui , Matsudaira Paul 
Published: March 2014

Abstract
Master transcription factors Oct4, Sox2, and Nanog are required to maintain the pluripotency and self-renewal of embryonic stem cells (ESCs) by regulating a specific transcriptional network. A few other transcription factors have been shown to be important in ESCs by interacting with these master transcription factors; however, little is known about the transcriptional mechanisms regulated by coregulators (coactivators and corepressors). In this study, we examined the function of two highly homologous coactivators, p300 and CREB-binding protein (CBP), in ESCs. We find that these two coactivators play redundant roles in maintaining the undifferentiated state of ESCs. They are recruited by Nanog through physical interaction to Nanog binding loci, mediating the formation of long-range chromatin looping structures, which is essential to maintain ESC-specific gene expression. Further functional studies reveal that the p300/CBP binding looping fragments contain enhancer activities, suggesting that the formation of p300/CBP-mediated looping structures may recruit distal enhancers to create a concentration of factors for the transcription activation of genes that are involved in self-renewal and pluripotency. Overall, these results provide a total new insight into the transcriptional regulation mechanism of coactivators p300 and CBP in ESCs, which is important in maintaining self-renewal and pluripotency, by mediating the formation of higher order chromosome structures. Stem Cells 2014;32:1805–1816
How to make sense of our rivers: using assemblage to understand angling
Authors: Bracken Louise J. , Oughton Elizabeth 
Published: March 2014

Our freshwater habitats are under threat and governance of these systems is rapidly evolving. It is thus important to examine how we make sense of our rivers and how this understanding can underpin catchment management. Assemblage is one approach that can be used to understand our freshwater environments. In this article we reflect on an interdisciplinary project on angling to evaluate whether using assemblage may help us comprehend our rivers in new ways. We work through themes of: different perspectives of river processes, what constitutes evidence used in decision making, how the nexus between wildlife and the physical environment plays out, and the importance of rivers to our well‐being. We demonstrate how assemblage can facilitate a deeper and more comprehensive understanding of relational processes and how these evolve over time. Assemblage can thus be used as a way of exploring rivers to support integrated management within complex systems of governance.This article is categorized under:Water and Life > Conservation, Management, and AwarenessHuman Water > Water Governance
Audience segmentation and climate change communication: conceptual and methodological considerations
Authors: Hine Donald W , Reser Joseph P , Morrison Mark , Phillips Wendy J , Nunn Patrick , Cooksey Ray 
Published: March 2014

Engaging the public about mitigating or adapting to climate change threats poses significant challenges for scientists, policy makers, and others responsible for developing communication strategies. In response to these challenges, interest is growing in audience segmentation as a possible strategy to develop more effective communications that are tailored and targeted to subgroups of the public who share similar values, beliefs, behaviors, and/or policy preferences about climate change. In this article, we provide a brief historical overview of audience segmentation and its applications to marketing, health, politics, and most recently climate change. We then critically evaluate several conceptual arguments about whether segmentation is an appropriate strategy for climate change communications, review key methodological considerations associated with conducting segmentation analyses, and make several recommendations about best practice. We conclude that, in principle, audience segmentation and targeted messaging are potentially valuable tools for enhancing climate change communication. But, in practice, there are conceptual and methodological complexities of which practitioners and consumers should be aware when conducting and interpreting the results of segmentation studies. In addition, more research is required, particularly related to tailoring and targeting messages to identified segments, before these strategies can be considered to have a sufficient evidence base to warrant widespread adoption.This article is categorized under:

Perceptions, Behavior, and Communication of Climate Change > Perceptions of Climate Change
Climate change mitigation policies and poverty
Authors: Barbier Edward B 
Published: March 2014

Climate change mitigation policies include a wide range of actions, including efforts to reduce greenhouse gas (GHG) emissions from fossil fuel combustion, energy efficiency and end‐use innovations, and reducing carbon emissions through avoided deforestation. Such policies can affect poverty in developing countries either directly or indirectly. Direct impacts on poverty include payments for avoided deforestation that affect the livelihoods of the poor, reduced GHG emissions that also produce co‐benefits of improved air quality and health, and clean energy and energy efficiency effects on energy poverty. Indirect impacts on the poor in developing countries occur through the changes in trade, economic growth, and other economy‐wide effects. To date, there is a lack of systematic or comprehensive analyses of these direct and indirect impacts of mitigation policies on the poor. Although such policies may benefit the poor, some actions may worsen poverty and hinder its alleviation. This suggests that a more comprehensive approach should be employed in analyzing how mitigation policies affect the poor in developing countries, and in particular, in assessing how policy design and implementation can influence the potential trade‐offs between the positive and negative impacts on poverty alleviation.This article is categorized under:

Climate Economics > Economics and Climate Change
Climate and Development > Social Justice and the Politics of Development