bluuebunny/crossref_metadata_2025 huggingface dataset:
Early colonizing Esche richia coli elicits remodeling of rat colonic epithelium shifting toward a new homeostatic state
Authors: Tomas Julie , Reygner Julie , Mayeur Camille , Ducroc Robert , Bouet Stephan , Bridonneau Chantal , Cavin Jean-Baptiste , Thomas Muriel , Langella Philippe , Cherbuy Claire
Published: July 2014

We investigated the effects of early colonizing bacteria on the colonic epithelium. We isolated dominant bacteria, Escherichia coli, Enterococcus faecalis, Lactobacillus intestinalis, Clostridium innocuum and a novel Fusobacterium spp., from the intestinal contents of conventional suckling rats and transferred them in different combinations into germfree (GF) adult rats. Animals were investigated after various times up to 21 days. Proliferative cell markers (Ki67, proliferating cell nuclear antigen, phospho-histone H3, cyclin A) were higher in rats monocolonized with E. coli than in GF at all time points, but not in rats monocolonized with E. faecalis. The mucin content of goblet cells declined shortly after E. coli administration whereas the mucus layer doubled in thickness. Fluorescence in situ hybridization analyses revealed that E. coli resides in this mucus layer. The epithelial mucin content progressively returned to baseline, following an increase in KLF4 and in the cell cycle arrest-related proteins p21CIP1 and p27KIP1. Markers of colonic differentiated cells involved in electrolyte (carbonic anhydrase II and slc26A3) and water (aquaglyceroporin3 (aqp3)) transport, and secretory responses to carbachol were modulated after E. coli inoculation suggesting that ion transport dynamics were also affected. The colonic responses to simplified microbiotas differed substantially according to whether or not E. coli was combined with the other four bacteria. Thus, proliferation markers increased substantially when E. coli was in the mix, but very much less when it was absent. This work demonstrates that a pioneer strain of E. coli elicits sequential epithelial remodeling affecting the structure, mucus layer and ionic movements and suggests this can result in a microbiota-compliant state.
Interpreting 16S metagenomic data without clustering to achieve sub-OTU resolution
Authors: Tikhonov Mikhail , Leach Robert W , Wingreen Ned S
Published: July 2014

The standard approach to analyzing 16S tag sequence data, which relies on clustering reads by sequence similarity into Operational Taxonomic Units (OTUs), underexploits the accuracy of modern sequencing technology. We present a clustering-free approach to multi-sample Illumina data sets that can identify independent bacterial subpopulations regardless of the similarity of their 16S tag sequences. Using published data from a longitudinal time-series study of human tongue microbiota, we are able to resolve within standard 97% similarity OTUs up to 20 distinct subpopulations, all ecologically distinct but with 16S tags differing by as little as one nucleotide (99.2% similarity). A comparative analysis of oral communities of two cohabiting individuals reveals that most such subpopulations are shared between the two communities at 100% sequence identity, and that dynamical similarity between subpopulations in one host is strongly predictive of dynamical similarity between the same subpopulations in the other host. Our method can also be applied to samples collected in cross-sectional studies and can be used with the 454 sequencing platform. We discuss how the sub-OTU resolution of our approach can provide new insight into factors shaping community assembly.
Microbial dormancy improves development and experimental validation of ecosystem model
Authors: Wang Gangsheng , Jagadamma Sindhu , Mayes Melanie A , Schadt Christopher W , Megan Steinweg J , Gu Lianhong , Post Wilfred M
Published: July 2014

Climate feedbacks from soils can result from environmental change followed by response of plant and microbial communities, and/or associated changes in nutrient cycling. Explicit consideration of microbial life-history traits and functions may be necessary to predict climate feedbacks owing to changes in the physiology and community composition of microbes and their associated effect on carbon cycling. Here we developed the microbial enzyme-mediated decomposition (MEND) model by incorporating microbial dormancy and the ability to track multiple isotopes of carbon. We tested two versions of MEND, that is, MEND with dormancy (MEND) and MEND without dormancy (MEND_wod), against long-term (270 days) carbon decomposition data from laboratory incubations of four soils with isotopically labeled substrates. MEND_wod adequately fitted multiple observations (total C–CO2 and 14C–CO2 respiration, and dissolved organic carbon), but at the cost of significantly underestimating the total microbial biomass. MEND improved estimates of microbial biomass by 20–71% over MEND_wod. We also quantified uncertainties in parameters and model simulations using the Critical Objective Function Index method, which is based on a global stochastic optimization algorithm, as well as model complexity and observational data availability. Together our model extrapolations of the incubation study show that long-term soil incubations with experimental data for multiple carbon pools are conducive to estimate both decomposition and microbial parameters. These efforts should provide essential support to future field- and global-scale simulations, and enable more confident predictions of feedbacks between environmental change and carbon cycling.
Astrocyte response to motor neuron injury promotes structural synaptic plasticity via STAT3-regulated TSP-1 expression
Authors: Tyzack Giulia E. , Sitnikov Sergey , Barson Daniel , Adams-Carr Kerala L. , Lau Nike K. , Kwok Jessica C. , Zhao Chao , Franklin Robin J. M. , Karadottir Ragnhildur T. , Fawcett James W. , Lakatos András
Published: July 2014

The role of remote astrocyte (AC) reaction to central or peripheral axonal insult is not clearly understood. Here we use a transgenic approach to compare the direct influence of normal with diminished AC reactivity on neuronal integrity and synapse recovery following extracranial facial nerve transection in mice. Our model allows straightforward interpretations of AC–neuron signalling by reducing confounding effects imposed by inflammatory cells. We show direct evidence that perineuronal reactive ACs play a major role in maintaining neuronal circuitry following distant axotomy. We reveal a novel function of astrocytic signal transducer and activator of transcription-3 (STAT3). STAT3 regulates perineuronal astrocytic process formation and re-expression of a synaptogenic molecule, thrombospondin-1 (TSP-1), apart from supporting neuronal integrity. We demonstrate that, through this new pathway, TSP-1 is responsible for the remote AC-mediated recovery of excitatory synapses onto axotomized motor neurons in adult mice. These data provide new targets for neuroprotective therapies via optimizing AC-driven plasticity.
High energy density rechargeable magnesium battery using earth-abundant and non-toxic elements
Authors: Orikasa Yuki , Masese Titus , Koyama Yukinori , Mori Takuya , Hattori Masashi , Yamamoto Kentaro , Okado Tetsuya , Huang Zhen-Dong , Minato Taketoshi , Tassel Cédric , Kim Jungeun , Kobayashi Yoji , Abe Takeshi , Kageyama Hiroshi , Uchimoto Yoshiharu
Published: July 2014

Rechargeable magnesium batteries are poised to be viable candidates for large-scale energy storage devices in smart grid communities and electric vehicles. However, the energy density of previously proposed rechargeable magnesium batteries is low, limited mainly by the cathode materials. Here, we present new design approaches for the cathode in order to realize a high-energy-density rechargeable magnesium battery system. Ion-exchanged MgFeSiO4 demonstrates a high reversible capacity exceeding 300 mAh·g−1 at a voltage of approximately 2.4 V vs. Mg. Further, the electronic and crystal structure of ion-exchanged MgFeSiO4 changes during the charging and discharging processes, which demonstrates the (de)insertion of magnesium in the host structure. The combination of ion-exchanged MgFeSiO4 with a magnesium bis(trifluoromethylsulfonyl)imide–triglyme electrolyte system proposed in this work provides a low-cost and practical rechargeable magnesium battery with high energy density, free from corrosion and safety problems.
Facile hydrothermal synthesis of CuFeO2 hexagonal platelets/rings and graphene composites as anode materials for lithium ion batteries
Authors: Dong Yucheng , Cao Chenwei , Chui Ying-San , Zapien Juan Antonio
Published: July 2014

Delafossite CuFeO2 hexagonal platelets/rings and graphene composites were synthesized by a low temperature hydrothermal method.
Incorporation of heterostructured Sn/SnO nanoparticles in crumpled nitrogen-doped graphene nanosheets for application as anodes in lithium-ion batteries
Authors: Du Fei-Hu , Liu Yu-Si , Long Jie , Zhu Qian-Cheng , Wang Kai-Xue , Wei Xiao , Chen Jie-Sheng
Published: July 2014

Sn/SnO nanoparticles are incorporated in crumpled nitrogen-doped graphene nanosheets by a simple melting diffusion method, generating a composite exhibiting excellent electrochemical performance.
Gold nanoparticles as electron reservoir redox catalysts for 4-nitrophenol reduction: a strong stereoelectronic ligand influence
Authors: Ciganda Roberto , Li Na , Deraedt Christophe , Gatard Sylvain , Zhao Pengxiang , Salmon Lionel , Hernández Ricardo , Ruiz Jaime , Astruc Didier
Published: July 2014

Gold nanoparticle-catalyzedp-nitrophenol reduction by NaBH4is shown to strongly depend on the stereoelectronic ligand properties involving surface electron reservoirs.
La2Ti2O7 nanoplates decorated with Cu2ZnSnS4 nanoparticles for enhanced visible-light-driven photocatalytic activity
Authors: Tian Xiaomeng , Liu Jingbing , Wang Hao , Yan Hui
Published: July 2014

Novel Cu2ZnSnS4/La2Ti2O7 hetero-junction photocatalysts with high visible-light-driven photocatalytic activities were achieved by a green process.
Facile synthesis of exfoliated Co–Al LDH–carbon nanotube composites with high performance as supercapacitor electrodes
Authors: Yu Lei , Shi Nannan , Liu Qi , Wang Jun , Yang Bin , Wang Bin , Yan Huijun , Sun Yanbo , Jing Xiaoyan
Published: July 2014

A novel sandwich-like structured Co–Al LDH–CNT composite has been successfully synthesized. The as-prepared Co–Al LDHs–CNTs composite exhibites a high specific capacitance and a good cycle stability over 2000 cycles
Use of side-chain for rational design of n-type diketopyrrolopyrrole-based conjugated polymers: what did we find out?
Authors: Kanimozhi Catherine , Yaacobi-Gross Nir , Burnett Edmund K. , Briseno Alejandro L. , Anthopoulos Thomas D. , Salzner Ulrike , Patil Satish
Published: July 2014

Electron mobility of diketopyrrolopyrrole (DPP) based alternating copolymers of >2 cm2V−1s−1requires the combination of strong intramolecular conjugation along the polymer backbone with optimized intermolecular interactions that can be tuned with suitable side-chains.
Structural distortions in molecular-based quantum cellular automata: a minimal model based study
Authors: Santana Bonilla Alejandro , Gutierrez Rafael , Medrano Sandonas Leonardo , Nozaki Daijiro , Bramanti Alessandro Paolo , Cuniberti Gianaurelio
Published: July 2014

Molecular-based quantum cellular automata (m-QCA) offer a novel alternative in which binary information can be encoded in the molecular charge configuration of a cell and propagatedvianearest-neighbor Coulombic cell–cell interactions. Structural distortions of the cells may have however a sensitive influence on the m-QCA response and thus, potentially alter its functionality.
A unified study for water adsorption on metals: meaningful models from structural motifs
Authors: Revilla-López Guillem , López Núria
Published: July 2014

We present a comprehensive structural model that allows the rapid assessment of the first layer of water adsorption on metals for different motifs.
Recent progress in design, synthesis, and applications of one-dimensional TiO2 nanostructured surface heterostructures: a review
Authors: Tian Jian , Zhao Zhenhuan , Kumar Anil , Boughton Robert I. , Liu Hong
Published: July 2014

One-dimensional TiO2 nanostructured surface heterostructures (1D TiO2NSHs) have been comprehensively studied during the past two decades because of the possible practical applications in various fields, including photocatalysis, dye-sensitized solar cells, sensors, lithium batteries, biomedicine, catalysis, and supercapacitors.
Designed synthesis of CO2-promoted copper(ii) coordination polymers: synthesis, structural and spectroscopic characterization, and studies of versatile functional properties
Authors: Ghosh Pritam , Roychowdhury Additi , Corbella Montserrat , Bhaumik Asim , Mitra Partha , Mobin Shaikh M. , Mukherjee Ayan , Basu Soumen , Banerjee Priyabrata
Published: July 2014

A series of CO2-promoted Cu(ii) coordination polymers in different coordination environments has been synthesized.
Fermentation of hydrolysate detoxified by pervaporation through block copolymer membranes
Authors: Greer Douglas R. , Basso Thalita P. , Ibanez Ana B. , Bauer Stefan , Skerker Jeffrey M. , Ozcam A. Evren , Leon Dacia , Shin Chaeyoung , Arkin Adam P. , Balsara Nitash P.
Published: July 2014

Hydrolysate was pervaporated with a block copolymer membrane, removing inhibitors but leaving sugars, creating a viable fermentation broth.
Development of a tripartite solvent blend for sustainable chromatography
Authors: Chardon Florence M. , Blaquiere Nicole , Castanedo Georgette M. , Koenig Stefan G.
Published: July 2014

Favorable solvents supplant dichloromethane in routine silica gel chromatography and eliminate halogenated waste, thereby improving safety, economics, and environmental impact.
Epistatic interactions among metabolic genes depend upon environmental conditions
Authors: Jagdishchandra Joshi Chintan , Prasad Ashok
Published: July 2014

Different environmental conditions lead to different metabolic flows, leading to changes in epistasis interactions between genes. Epistasis in turn affects the adaptive fitness landscape.
Proteome-wide analysis of human disease mutations in short linear motifs: neglected players in cancer?
Authors: Uyar Bora , Weatheritt Robert J. , Dinkel Holger , Davey Norman E. , Gibson Toby J.
Published: July 2014

Mutations in short linear motifs impair the functions of intrinsically disordered proteins in cellular signaling/regulation and contribute substantially to human diseases.
A self-replicating peptide nucleic acid
Authors: Plöger Tobias A. , von Kiedrowski Günter
Published: July 2014

This paper presents evidence for self-replication in a most basic PNA molecular network and provides an explanation for the underlying kinetics.
Synthesis of gold and palladium nanoshells by in situ generation of seeds on silica nanoparticle cores
Authors: Grzincic Elissa , Teh Ruishen , Wallen Rachel , McGuire Gabrielle , Yella Avinash , Li Ben Q. , Bandyopadhyay Krisanu
Published: July 2014

Gold and palladium nanoshells are formed on polyethyleneimine silane functionalized silica nanoparticle cores using in situ generated metal nanoparticle seeds.
Photocatalytic homolysis of methyl formate to dry formaldehyde on PdO/TiO2: photocatalytic reverse Tishchenko reaction of methyl formate
Authors: Koirala Agni Raj , Docao Son , Yoon Kyung Byung
Published: July 2014

Photocatalytic homolysis of dry methyl formate (MF) to dry formaldehyde readily takes place in high selectivity (≥80%) upon irradiation of MF vapour on PdO/TiO2 in the 385–1050 nm region.
Triple excitation with dual emission in paramagnetic ZnO:Er3+ nanocrystals
Authors: Bishnoi Swati , Khichar Naveen , Das Rupali , Kumar Vineet , Kotnala R. K. , Chawla Santa
Published: July 2014

Confocal fluorescence images and emission spectra of ZnO:Er3± nanocrystals showing triple excitation.
Are creative comparisons developed by prospective chemistry teachers evidence of their conceptual understanding? The case of inter- and intramolecular forces
Authors: Sendur Gulten
Published: July 2014

The aim of this study is to determine prospective chemistry teachers' creative comparisons about the basic concepts of inter- and intramolecular forces, and to uncover the relationship between these creative comparisons and prospective teachers' conceptual understanding. Based on a phenomenological research method, this study was conducted with 101 prospective chemistry teachers studying in the Chemistry Education Department at a state university in Turkey in the academic year 2011–2012. The research made use of two data collection instruments, a creative comparison questionnaire and semi-structured interviews. The concepts of “non-polar covalent bonds, dipole–dipole force, hydrogen bonds, ionic bonds, covalent bonds, polar covalent bonds, and van der Waals force” were set out in the creative comparison questionnaire and the prospective teachers were asked to complete the sentences about these concepts (example: ionic bond is like .......... because ...........). Content analysis techniques were employed in the analysis of the creative comparisons set out in the questionnaire. The analysis of the data revealed that the prospective teachers generally developed their creative comparisons based on the formation and strength of the different bonds and that they also had alternative conceptions, particularly regarding the formation of covalent bonds, hydrogen bonds, and the van der Waals force. Semi-structured interviews were conducted in order to learn more about this and obtain detailed information about the level of understanding of the prospective teachers. Twelve prospective teachers were selected for the interviews on the basis of the creative comparisons they had developed in the creative comparison questionnaire. The analysis of the interviews showed that the level of conceptual understanding of the prospective teachers was not tightly linked to the complexity of their creative comparisons. However, it was seen that the creative comparisons submitted by the prospective teachers could be used to infer their conceptual understanding. Also, these creative comparisons could be helpful in determining what the prospective teachers' alternative conceptions were.
Application of layer-by-layer coatings to tissue scaffolds – development of an angiogenic biomaterial
Authors: Easton C. D. , Bullock A. J. , Gigliobianco G. , McArthur S. L. , MacNeil S.
Published: July 2014

Development of flexible coating strategies to promote angiogenesis is critical to effectively treat chronic, non-healing wounds.
A star-shaped D–π–A small molecule based on a tris(2-methoxyphenyl)amine core for highly efficient solution-processed organic solar cells
Authors: Min Jie , Luponosov Yuriy N. , Solodukhin Alexander N. , Kausch-Busies Nina , Ponomarenko Sergei A. , Ameri Tayebeh , Brabec Christoph J.
Published: July 2014

A star-shaped D–π–A small molecule based on a tris(2-methoxyphenyl)amine donor unit for solution-processed organic solar cells achieves a power conversion efficiency up to 4.38%.
Direct Comparison of Three Commercially Available Devices for Voice Ambulatory Monitoring and Biofeedback
Authors: Van Stan Jarrad H. , Gustafsson Joakim , Schalling Ellika , Hillman Robert E.
Published: July 2014

Purpose: To provide a direct comparison of three commercially available devices for voice ambulatory monitoring and biofeedback to assist voice clinicians and researchers in choosing the device that best meets their needs.

Methods: The Ambulatory Phonation Monitor (APM), VocaLog, and VoxLog were descriptively compared regarding cost, availability, physical characteristics, and operational features; and quantitatively compared regarding measures of loudness (dB sound pressure level [SPL]), pitch (fundamental frequency – F0), and phonation time. The quantitative comparison used simultaneous registrations acquired during a 90-minute lecture which also included a Smartphone-based system designed to capture the raw voice signal as a reference.

Results: Differences regarding cost, physical characteristics, and operational features could influence device choice. All three devices register SPL and phonation time, and also biofeedback based on SPL. Furthermore, the APM and VoxLog provide monitoring and biofeedback for F0 with the associated capability of providing additional measures related to vocal dose. All devices produced comparable results for common measures, except for the overestimation of phonation time by the VocaLog.

Conclusions: The cost, operational features, and performance characteristics of the three commercially available devices for voice ambulatory monitoring and biofeedback differ in ways that can significantly impact decisions about which one is best suited for a particular application.
Takagi–Sugeno fuzzy‐based incremental conductance algorithm for maximum power point tracking of a photovoltaic generating system
Authors: Sekhar Perumalla Chandra , Mishra Sukumar
Published: July 2014

Sluggish tracking for change in solar irradiations is the main demerit of the perturb and observe (P&O) algorithm because of its fixed perturb. To overcome this, an adaptive tracking algorithm based on Takagi–Sugeno fuzzy implications is proposed in this study. Input to the fuzzy controller is the error between conductance and incremental conductance which is otherwise zero at the maximum power point. The P&O algorithm and the proposed algorithm along with the recently published adaptive incremental conductance algorithm are examined for their performance efficacy on a photovoltaic (PV) generating system with fabricated as well as real irradiation data. As a case study, all the considered algorithms are validated under partial shading conditions also. The effectiveness of the proposed algorithm is verified for the tracking of the maximum power point of a PV system in steady as well as changing irradiations and the conclusions are supported through some experimental validations.
National Trends in Outpatient Surgical Treatment of Degenerative Cervical Spine Disease
Authors: Baird Evan O. , Egorova Natalia N. , McAnany Steven J. , Qureshi Sheeraz A. , Hecht Andrew C. , Cho Samuel K.
Published: July 2014

Study Design

Retrospective population-based observational study.

Objective

To assess the growth of cervical spine surgery performed in an outpatient setting.

Methods

A retrospective study was conducted using the United States Healthcare Cost and Utilization Project's State Inpatient and Ambulatory Surgery Databases for California, New York, Florida, and Maryland from 2005 to 2009. Current Procedural Terminology, fourth revision (CPT-4) and International Classification of Diseases, ninth revision Clinical Modification (ICD-9-CM) codes were used to identify operations for degenerative cervical spine diseases in adults (age > 20 years). Disposition and complication rates were examined.

Results

There was an increase in cervical spine surgeries performed in an ambulatory setting during the study period. Anterior cervical diskectomy and fusion accounted for 68% of outpatient procedures; posterior decompression made up 21%. Younger patients predominantly underwent anterior fusion procedures, and patients in the eighth and ninth decades of life had more posterior decompressions. Charlson comorbidity index and complication rates were substantially lower for ambulatory cases when compared with inpatients. The majority (>99%) of patients were discharged home following ambulatory surgery.

Conclusions

Recently, the number of cervical spine surgeries has increased in general, and more of these procedures are being performed in an ambulatory setting. The majority (>99%) of patients are discharged home but the nature of analyzing administrative data limits accurate assessment of postoperative complications and thus patient safety. This increase in outpatient cervical spine surgery necessitates further discussion of its safety.
Experimental measurements and noise analysis of a cryogenic radiometer
Authors: Carr S. M. , Woods S. I. , Jung T. M. , Carter A. C. , Datla R. U.
Published: July 2014

A cryogenic radiometer device, intended for use as part of an electrical-substitution radiometer, was measured at low temperature. The device consists of a receiver cavity mechanically and thermally connected to a temperature-controlled stage through a thin-walled polyimide tube which serves as a weak thermal link. With the temperature difference between the receiver and the stage measured in millikelvin and the electrical power measured in picowatts, the measured responsivity was 4700 K/mW and the measured thermal time constant was 14 s at a stage temperature of 1.885 K. Noise analysis in terms of Noise Equivalent Power (NEP) was used to quantify the various fundamental and technical noise contributions, including phonon noise and Johnson-Nyquist noise. The noise analysis clarifies the path toward a cryogenic radiometer with a noise floor limited by fundamental phonon noise, where the magnitude of the phonon NEP is 6.5 \documentclass[12pt]{minimal}\begin{document}${\mathrm{fW}}/\sqrt{\mathrm{Hz}}$\end{document} fW / Hz for the measured experimental parameters.
High-speed force mapping on living cells with a small cantilever atomic force microscope
Authors: Braunsmann Christoph , Seifert Jan , Rheinlaender Johannes , Schäffer Tilman E.
Published: July 2014

The imaging speed of the wide-spread force mapping mode for quantitative mechanical measurements on soft samples in liquid with the atomic force microscope (AFM) is limited by the bandwidth of the z-scanner and viscous drag forces on the cantilever. Here, we applied high-speed, large scan-range atomic force microscopy and small cantilevers to increase the speed of force mapping by ≈10−100 times. This allowed resolving dynamic processes on living mouse embryonic fibroblasts. Cytoskeleton reorganization during cell locomotion, growth of individual cytoskeleton fibers, cell blebbing, and the formation of endocytic pits in the cell membrane were observed. Increasing the force curve rate from 2 to 300 Hz increased the measured apparent Young's modulus of the cells by about 10 times, which facilitated force mapping measurements at high speed.
New tools for the systematic analysis and visualization of electronic excitations. I. Formalism
Authors: Plasser Felix , Wormit Michael , Dreuw Andreas
Published: July 2014

A variety of density matrix based methods for the analysis and visualization of electronic excitations are discussed and their implementation within the framework of the algebraic diagrammatic construction of the polarization propagator is reported. Their mathematical expressions are given and an extensive phenomenological discussion is provided to aid the interpretation of the results. Starting from several standard procedures, e.g., population analysis, natural orbital decomposition, and density plotting, we proceed to more advanced concepts of natural transition orbitals and attachment/detachment densities. In addition, special focus is laid on information coded in the transition density matrix and its phenomenological analysis in terms of an electron-hole picture. Taking advantage of both the orbital and real space representations of the density matrices, the physical information in these analysis methods is outlined, and similarities and differences between the approaches are highlighted. Moreover, new analysis tools for excited states are introduced including state averaged natural transition orbitals, which give a compact description of a number of states simultaneously, and natural difference orbitals (defined as the eigenvectors of the difference density matrix), which reveal details about orbital relaxation effects.
Progress of neutral-beam-aided diagnostics on the HL-2A tokamak
Authors: Yu D. L. , Wei Y. L. , Liu L. , Cao J. Y. , Ma Q. , Chen W. J. , Liu Y. , Yan L. W. , Yang Q. W. , Duan X. R.
Published: July 2014

A 32/64-channel Charge eXchange Recombination Spectroscopy (CXRS) and a 7-channel motional Stark effect (MSE) polarimeter have been developed on the HL-2A tokamak. To extract the maximum time resolution of the system, the incidence fibers of the spectrometer are pitch-controlled; and the double-slit fiber bundle can increase the spatial channels with one charge-coupled device detector. The ion temperature and plasma rotation with time and spatial resolutions up to 5 ms and 1 cm are obtained. Sawtooth oscillation, transition from intermediate phase (I phase) to high confinement mode (H mode) can be clearly observed by the CXRS. The spectrometer can be utilized as the main component of the MSE polarimeter, which can effectively overcome the weak Stark effect. The pitch angles of magnetic field are obtained for 7 spatial points covering 24 cm along major radius with time resolution of 40 ms.
Proposed measurement of spin currents in a GaAs crystal using the electro-optical Pockels effect
Authors: Zhang Xingchu , Zheng Yongjun , She Weilong
Published: July 2014

A new method for measuring spin currents is proposed, based on the linear electro-optic (Pockels) effect caused by the additional second-order nonlinear electric susceptibility (electro-optic tensor) generated by the spin currents. The non-zero elements of electro-optic tensor induced by spin currents in GaAs crystal are calculated, and the wave coupling theory of linear electro-optic effect is used to analyze the polarization change of a probe beam. The numerical results show that, for a linearly polarized probe beam with a frequency close to the band gap of GaAs crystal, its polarization rotation can be as large as 14 μrad under an applied electric field of about 350 V/mm. This effect should offer an alternative detection method for spintronics.
Jumping-droplet electrostatic energy harvesting
Authors: Miljkovic Nenad , Preston Daniel J. , Enright Ryan , Wang Evelyn N.
Published: July 2014

Micro- and nanoscale wetting phenomena have been an active area of research due to its potential for improving engineered system performance involving phase change. With the recent advancements in micro/nanofabrication techniques, structured surfaces can now be designed to allow condensing coalesced droplets to spontaneously jump off the surface due to the conversion of excess surface energy into kinetic energy. In addition to being removed at micrometric length scales (∼10 μm), jumping water droplets also attain a positive electrostatic charge (∼10–100 fC) from the hydrophobic coating/condensate interaction. In this work, we take advantage of this droplet charging to demonstrate jumping-droplet electrostatic energy harvesting. The charged droplets jump between superhydrophobic copper oxide and hydrophilic copper surfaces to create an electrostatic potential and generate power during formation of atmospheric dew. We demonstrated power densities of ∼15 pW/cm2, which, in the near term, can be improved to ∼1 μW/cm2. This work demonstrates a surface engineered platform that promises to be low cost and scalable for atmospheric energy harvesting and electric power generation.
Microfluidic platform for the study of intercellular communication via soluble factor-cell and cell-cell paracrine signaling
Authors: Byrne Matthew B. , Trump Lisa , Desai Amit V. , Schook Lawrence B. , Gaskins H. Rex , Kenis Paul J. A.
Published: July 2014

Diffusion of autocrine and paracrine signaling molecules allows cells to communicate in the absence of physical contact. This chemical-based, long-range communication serves crucial roles in tissue function, activation of the immune system, and other physiological functions. Despite its importance, few in vitro methods to study cell-cell signaling through paracrine factors are available today. Here, we report the design and validation of a microfluidic platform that enables (i) soluble molecule-cell and/or (ii) cell-cell paracrine signaling. In the microfluidic platform, multiple cell populations can be introduced into parallel channels. The channels are separated by arrays of posts allowing diffusion of paracrine molecules between cell populations. A computational analysis was performed to aid design of the microfluidic platform. Specifically, it revealed that channel spacing affects both spatial and temporal distribution of signaling molecules, while the initial concentration of the signaling molecule mainly affects the concentration of the signaling molecules excreted by the cells. To validate the microfluidic platform, a model system composed of the signaling molecule lipopolysaccharide, mouse macrophages, and engineered human embryonic kidney cells was introduced into the platform. Upon diffusion from the first channel to the second channel, lipopolysaccharide activates the macrophages which begin to produce TNF-α. The TNF-α diffuses from the second channel to the third channel to stimulate the kidney cells, which express green fluorescent protein (GFP) in response. By increasing the initial lipopolysaccharide concentration an increase in fluorescent response was recorded, demonstrating the ability to quantify intercellular communication between 3D cellular constructs using the microfluidic platform reported here. Overall, these studies provide a detailed analysis on how concentration of the initial signaling molecules, spatiotemporal dynamics, and inter-channel spacing affect intercellular communication.
Ultra-narrow ferromagnetic resonance in organic-based thin films grown via low temperature chemical vapor deposition
Authors: Yu H. , Harberts M. , Adur R. , Lu Y. , Hammel P. Chris , Johnston-Halperin E. , Epstein A. J.
Published: July 2014

We present the growth of thin films of the organic-based ferrimagnetic semiconductor V[TCNE]x (x ∼ 2, TCNE: tetracyanoethylene) via chemical vapor deposition. Under optimized growth conditions, we observe a significant increase in magnetic homogeneity, as evidenced by a Curie temperature above 600 K and sharp magnetization switching. Further, ferromagnetic resonance studies reveal a single resonance with full width at half maximum linewidth of 1.4 G, comparable to the narrowest lines measured in inorganic magnetic materials and in contrast to previous studies that showed multiple resonance features. These characteristics are promising for the development of high frequency electronic devices that take advantage of the unique properties of this organic-based material, such as the potential for low cost synthesis combined with low temperature and conformal deposition on a wide variety of substrates.
Linear phase distribution of acoustical vortices
Authors: Gao Lu , Zheng Haixiang , Ma Qingyu , Tu Juan , Zhang Dong
Published: July 2014

Linear phase distribution of phase-coded acoustical vortices was theoretically investigated based on the radiation theory of point source, and then confirmed by experimental measurements. With the proposed criterion of positive phase slope, the possibility of constructing linear circular phase distributions is demonstrated to be determined by source parameters. Improved phase linearity can be achieved at larger source number, lower frequency, smaller vortex radius, and/or longer axial distance. Good agreements are observed between numerical simulations and measurement results for circular phase distributions. The favorable results confirm the feasibility of precise phase control for acoustical vortices and suggest potential applications in particle manipulation.
Strong self-focusing of a cosh-Gaussian laser beam in collisionless magneto-plasma under plasma density ramp
Authors: Nanda Vikas , Kant Niti
Published: July 2014

The effect of plasma density ramp on self-focusing of cosh-Gaussian laser beam considering ponderomotive nonlinearity is analyzed using WKB and paraxial approximation. It is noticed that cosh-Gaussian laser beam focused earlier than Gaussian beam. The focusing and de-focusing nature of the cosh-Gaussian laser beam with decentered parameter, intensity parameter, magnetic field, and relative density parameter has been studied and strong self-focusing is reported. It is investigated that decentered parameter “b” plays a significant role for the self-focusing of the laser beam as for b=2.12, strong self-focusing is seen. Further, it is observed that extraordinary mode is more prominent toward self-focusing rather than ordinary mode of propagation. For b=2.12, with the increase in the value of magnetic field self-focusing effect, in case of extraordinary mode, becomes very strong under plasma density ramp. Present study may be very useful in the applications like the generation of inertial fusion energy driven by lasers, laser driven accelerators, and x-ray lasers. Moreover, plasma density ramp plays a vital role to enhance the self-focusing effect.
Enhanced thermoelectric performance of a quintuple layer of Bi2Te3
Authors: Zhang J. , Liu H. J. , Cheng L. , Wei J. , Shi J. , Tang X. F. , Uher C.
Published: July 2014

The electronic structure of a quintuple layer (QL) of Bi2Te3 is calculated using the first-principles pseudopotential method. It is found that the band gap of an isolated QL is considerably larger than that of bulk Bi2Te3. The electronic transport of the QL is, then, evaluated using the semiclassical Boltzmann theory within the relaxation time approximation. By fitting the energy surface from first-principles calculations, a suitable Morse potential is constructed and used to predicate the lattice thermal conductivity via equilibrium molecular dynamics simulations. By optimizing the carrier concentration of the system, the ZT of Bi2Te3 QL can be enhanced to a relatively high value. Moreover, the ZT value exhibits strong temperature dependence and can reach as high as 2.0 at 800 K. This value can be further increased to 2.2 by the substitution of Bi atoms with Sb atoms, giving nominal formula of (Bi0.25Sb0.75)2Te3. The significantly enhanced ZT value makes QL a very appealing candidate for thermoelectric applications.
A brush-shaped air plasma jet operated in glow discharge mode at atmospheric pressure
Authors: Li Xuechen , Bao Wenting , Jia Pengying , Di Cong
Published: July 2014

Using ambient air as working gas, a direct-current plasma jet is developed to generate a brush-shaped plasma plume with fairly large volume. Although a direct-current power supply is used, the discharge shows a pulsed characteristic. Based on the voltage-current curve and fast photography, the brush-shaped plume, like the gliding arc plasma, is in fact a temporal superposition of a moving discharge filament in an arched shape. During it moves away from the nozzle, the discharge evolves from a low-current arc into a normal glow in one discharge cycle. The emission profile is explained qualitatively based on the dynamics of the plasma brush.
High power terahertz generation using 1550 nm plasmonic photomixers
Authors: Berry Christopher W. , Hashemi Mohammad R. , Preu Sascha , Lu Hong , Gossard Arthur C. , Jarrahi Mona
Published: July 2014

We present a 1550 nm plasmonic photomixer operating under pumping duty cycles below 10%, which offers significantly higher terahertz radiation power levels compared to previously demonstrated photomixers. The record-high terahertz radiation powers are enabled by enhancing the device quantum efficiency through use of plasmonic contact electrodes, and by mitigating thermal breakdown at high optical pump power levels through use of a low duty cycle optical pump. The repetition rate of the optical pump can be specifically selected at a given pump duty cycle to control the spectral linewidth of the generated terahertz radiation. At an average optical pump power of 150 mW with a pump modulation frequency of 1 MHz and pump duty cycle of 2%, we demonstrate up to 0.8 mW radiation power at 1 THz, within each continuous wave radiation cycle.
India's Urban Revolution: Geographies of Displacement beyond Gentrification
Authors: Ghertner D Asher
Published: July 2014

This paper uses an analysis of key dynamics of sociospatial change in Indian cities to offer a sympathetic critique of recent efforts to extend gentrification theory into the Global South. Despite the postcolonial overtures of this new, Southern gentrification literature, the paper argues that the global search for gentrification risks following a diffusionist logic that either presumes a Euro-American template, or else so sheers gentrification of its analytical specificity that it loses both its explanatory power and its political potency. The paper shows that gentrification theory operates on four implicit presumptions, which fail to characterize the primary dynamics of urban change in India. These include: (1) the presumption that lower-class displacement is driven by a reinvestment of capital into disinvested spaces; (2) a property centrism; (3) an agnosticism on the question of extraeconomic force; and (4) the presumption that land from which lower classes are displaced finds a ‘higher and better use’. A priori commitment to the gentrification analytic thus overlooks key features of urban change in contexts, like India, with property, planning, and legal systems different from the postindustrial geographies from which gentrification theory developed. The paper suggests that ‘urban revolution’, ‘enclosures’, and ‘accumulation by dispossession’, while equally abstract terms, more clearly allow for the comparative analysis of displacement.
EBV microRNA BART 18-5p targets MAP3K2 to facilitate persistence in vivo by inhibiting viral replication in B cells
Authors: Qiu Jin , Thorley-Lawson David A.
Published: July 2014

Significance

EBV is a human herpesvirus that is associated with several forms of cancer. It can transform B lymphocytes into proliferating lymphoblastoid cell lines yet establishes a benign lifetime latent infection in resting memory B cells in virtually all human beings. EBV encodes for ∼40 micro-RNAs, small RNAs that modulate the activity of cellular genes. A subset of these is highly expressed in latently infected memory B cells in vivo. Here, we show that one of them, 18-5p, suppresses the expression of MAP kinase kinase kinase 2 (MAP3K2). We further show that MAP3K2, a central molecule in many cellular signaling pathways, mediates the signals that initiate viral replication. Thus, 18-5p favors latency in vivo by suppressing viral replication through reduction of MAP3K2.
Rainfed intensive crop systems.
Authors: Olesen J. E.
Published: July 2014

This chapter focuses on the importance of intensive cropping systems in contributing to the world supply of food and feed. The impact of climate change on intensive crop production systems is also discussed.
Agricultural adaptation to climate change: new approaches to knowledge and learning.
Authors: Ingram J.
Published: July 2014

This chapter focuses on knowledge needs for farm-level agricultural adaptation. Although there is a large literature exploring the many dimensions of, and barriers to, climate change adaptation, there has been little analysis of knowledge requirements for agricultural adaptation. This chapter therefore draws on relevant work in areas such as extension and innovation science and farmer decision making and behavioural research in the wider context of sustainable agriculture and rural development. Further, the chapter emphasizes individual adaptations at the farm level but places the discussion within the wider context of agricultural knowledge and innovation systems where potentially planned adaptations can occur.
Considerations for protein intake in managing weight loss in athletes
Authors: Murphy Caoileann H. , Hector Amy J. , Phillips Stuart M.
Published: July 2014

A large body of evidence now shows that higher protein intakes (2–3 times the protein Recommended Dietary Allowance (RDA) of 0.8 g/kg/d) during periods of energy restriction can enhance fat‐free mass (FFM) preservation, particularly when combined with exercise. The mechanisms underpinning the FFM‐sparing effect of higher protein diets remain to be fully elucidated but may relate to the maintenance of the anabolic sensitivity of skeletal muscle to protein ingestion. From a practical point of view, athletes aiming to reduce fat mass and preserve FFM should be advised to consume protein intakes in the range of ∼1.8–2.7 g kg−1 d−1 (or ∼2.3–3.1 g kg−1 FFM) in combination with a moderate energy deficit (−500 kcal) and the performance of some form of resistance exercise. The target level of protein intake within this recommended range requires consideration of a number of case‐specific factors including the athlete's body composition, habitual protein intake and broader nutrition goals. Athletes should focus on consuming high‐quality protein sources, aiming to consume protein feedings evenly spaced throughout the day. Post‐exercise consumption of 0.25–0.3 g protein meal−1 from protein sources with high leucine content and rapid digestion kinetics (i.e. whey protein) is recommended to optimise exercise‐induced muscle protein synthesis. When protein is consumed as part of a mixed macronutrient meal and/or before bed slightly higher protein doses may be optimal.
Masked translation priming asymmetry in Chinese-English bilinguals: Making sense of the Sense Model
Authors: Xia Violet , Andrews Sally
Published: July 2014

Masked translation priming asymmetry is the robust finding that priming from a bilingual's first language (L1) to their second language (L2) is stronger than priming from L2 to L1. This asymmetry has been claimed to be task dependent. The Sense Model proposed by Finkbeiner, Forster, Nicol, and Nakamura (2004) claims that the asymmetry is reduced in semantic categorization relative to lexical decision due to a category filtering mechanism that limits the features considered in categorization decisions to dominant, category-relevant features. This paper reports two pairs of semantic categorization and lexical decision tasks designed to test the Sense Model's predictions. The experiments replicated the finding of Finkbeiner et al. that L2-L1 priming is somewhat stronger in semantic categorization than lexical decision, selectively for exemplars of the category. However, the direct comparison of L2-L1 and L1-L2 translation priming across tasks failed to confirm the Sense Model's central prediction that translation priming asymmetry is significantly reduced in semantic categorization. The data therefore fail to support the category filtering account of translation priming asymmetry. Rather, they suggest that pre-activation of conceptual features of the target category provides feedback to lexical forms that compensates for the weak connections between the lexical and conceptual representations of L2 words.
Convergence from below? The reform of minimum income protection in France and the UK
Authors: Clegg Daniel
Published: July 2014

Through a systematic comparison of major reforms to minimum income benefits for people of working age in France and the UK, this paper assesses the scope for cross-national convergence in this growing sector of European welfare states. It shows that while differing institutional legacies have shaped the precise design of the new minimum income systems that have been put in place on each side of the Channel in recent years, there is also evidence of an increasingly common conceptualisation of the function of the last safety net and its articulation with the labour market, despite the two countries' still very different political economies. This suggests the potential across welfare states for convergence “from below” on broader understandings of the role of social security provisions in regulating economic life.