bluuebunny/crossref_metadata_2025 huggingface dataset:
Congress Tussles over Bill to Provide Stability to NASA
Authors: Showstack Randy
Published: March 2016

Witnesses at a congressional hearing highlighted the need to provide stability to NASA but were lukewarm in supporting specific provisions of the proposed Space Leadership Preservation Act.
Protection from septic peritonitis by rapid neutrophil recruitment through omental high endothelial venules
Authors: Buscher Konrad , Wang Huiyu , Zhang Xueli , Striewski Paul , Wirth Benedikt , Saggu Gurpanna , Lütke-Enking Stefan , Mayadas Tanya N. , Ley Klaus , Sorokin Lydia , Song Jian
Published: March 2016

Acute peritonitis is a frequent medical condition that can trigger severe sepsis as a life-threatening complication. Neutrophils are first-responders in infection but recruitment mechanisms to the abdominal cavity remain poorly defined. Here, we demonstrate that high endothelial venules (HEVs) of the greater omentum constitute a main entry pathway in TNFα-, Escherichia coli (E. coli)- and caecal ligation and puncture-induced models of inflammation. Neutrophil transmigration across HEVs is faster than across conventional postcapillary venules and requires a unique set of adhesion receptors including peripheral node addressin, E-, L-selectin and Mac-1 but not P-selectin or LFA-1. Omental milky spots readily concentrate intra-abdominal E. coli where macrophages and recruited neutrophils collaborate in phagocytosis and killing. Inhibition of the omental neutrophil response exacerbates septic progression of peritonitis. This data identifies HEVs as a clinically relevant vascular recruitment site for neutrophils in acute peritonitis that is indispensable for host defence against early systemic bacterial spread and sepsis.
Dimensionality Reduction Based Optimization Algorithm for Sparse 3-D Image Reconstruction in Diffuse Optical Tomography
Authors: Bhowmik Tanmoy , Liu Hanli , Ye Zhou , Oraintara Soontorn
Published: March 2016

Diffuse optical tomography (DOT) is a relatively low cost and portable imaging modality for reconstruction of optical properties in a highly scattering medium, such as human tissue. The inverse problem in DOT is highly ill-posed, making reconstruction of high-quality image a critical challenge. Because of the nature of sparsity in DOT, sparsity regularization has been utilized to achieve high-quality DOT reconstruction. However, conventional approaches using sparse optimization are computationally expensive and have no selection criteria to optimize the regularization parameter. In this paper, a novel algorithm, Dimensionality Reduction based Optimization for DOT (DRO-DOT), is proposed. It reduces the dimensionality of the inverse DOT problem by reducing the number of unknowns in two steps and thereby makes the overall process fast. First, it constructs a low resolution voxel basis based on the sensing-matrix properties to find an image support. Second, it reconstructs the sparse image inside this support. To compensate for the reduced sensitivity with increasing depth, depth compensation is incorporated in DRO-DOT. An efficient method to optimally select the regularization parameter is proposed for obtaining a high-quality DOT image. DRO-DOT is also able to reconstruct high-resolution images even with a limited number of optodes in a spatially limited imaging set-up.
Holocene ice marginal fluctuations of the Qassimiut lobe in South Greenland
Authors: Larsen Nicolaj K. , Find Jesper , Kristensen Anders , Bjørk Anders A. , Kjeldsen Kristian K. , Odgaard Bent V. , Olsen Jesper , Kjær Kurt H.
Published: March 2016

Knowledge about the Holocene evolution of the Greenland ice sheet (GrIS) is important to put the recent observations of ice loss into a longer-term perspective. In this study, we use six new threshold lake records supplemented with two existing lake records to reconstruct the Holocene ice marginal fluctuations of the Qassimiut lobe (QL) – one of the most dynamic parts of the GrIS in South Greenland. Times when the ice margin was close to present extent are characterized by clastic input from the glacier meltwater, whereas periods when the ice margin was behind its present day extent comprise organic-rich sediments. We find that the overall pattern suggests that the central part of the ice lobe in low-lying areas experienced the most prolonged ice retreat from ~9–0.4 cal. ka BP, whereas the more distal parts of the ice lobe at higher elevation re-advanced and remained close to the present extent during the Neoglacial between ~4.4 and 1.8 cal. ka BP. These results demonstrate that the QL was primarily driven by Holocene climate changes, but also emphasises the role of local topography on the ice marginal fluctuations.
Morphology controlling method for amorphous silica nanoparticles and jellyfish-like nanowires and their luminescence properties
Authors: Liu Haitao , Huang Zhaohui , Huang Juntong , Xu Song , Fang Minghao , Liu Yan-gai , Wu Xiaowen , Zhang Shaowei
Published: March 2016

Uniform silica nanoparticles and jellyfish-like nanowires were synthesized by a chemical vapour deposition method on Si substrates treated without and with Ni(NO3)2, using silicon powder as the source material. Composition and structural characterization using field emission scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy and fourier-transform infrared spectroscopy showed that the as-prepared products were silica nanoparticles and nanowires which have amorphous structures. The form of nanoparticles should be related to gas-phase nucleation procedure. The growth of the nanowires was in accordance with vapour-liquid-solid mechanism, followed by Ostwald ripening to form the jellyfish-like morphology. Photoluminescence and cathodoluminescence measurements showed that the silica products excited by different light sources show different luminescence properties. The emission spectra of both silica nanoparticles and nanowires are due to the neutral oxygen vacancies (≡Si-Si≡). The as-synthesized silica with controlled morphology can find potential applications in future nanodevices with tailorable photoelectric properties.
Chaotic, informational and synchronous behaviour of multiplex networks
Authors: Baptista M. S. , Szmoski R. M. , Pereira R. F. , Pinto S. E. de Souza
Published: March 2016

The understanding of the relationship between topology and behaviour in interconnected networks would allow to charac- terise and predict behaviour in many real complex networks since both are usually not simultaneously known. Most previous studies have focused on the relationship between topology and synchronisation. In this work, we provide analytical formulas that shows how topology drives complex behaviour: chaos, information and weak or strong synchronisation; in multiplex net- works with constant Jacobian. We also study this relationship numerically in multiplex networks of Hindmarsh-Rose neurons. Whereas behaviour in the analytically tractable network is a direct but not trivial consequence of the spectra of eigenvalues of the Laplacian matrix, where behaviour may strongly depend on the break of symmetry in the topology of interconnections, in Hindmarsh-Rose neural networks the nonlinear nature of the chemical synapses breaks the elegant mathematical connec- tion between the spectra of eigenvalues of the Laplacian matrix and the behaviour of the network, creating networks whose behaviour strongly depends on the nature (chemical or electrical) of the inter synapses.
SIRT1 alleviates senescence of degenerative human intervertebral disc cartilage endo-plate cells via the p53/p21 pathway
Authors: Zhou Nian , Lin Xin , Dong Wen , Huang Wei , Jiang Wei , Lin Liangbo , Qiu Quanhe , Zhang Xiaojun , Shen Jieliang , Song Zhaojun , Liang Xi , Hao Jie , Wang Dawu , Hu Zhenming
Published: March 2016

Cartilage end plates (CEP) degeneration plays an integral role in intervertebral disc (IVD) degeneration resulting from nutrient diffusion disorders. Although cell senescence resulting from oxidative stress is known to contribute to degeneration, no studies concerning the role of senescence in CEP degeneration have been conducted. SIRT1 is a longevity gene that plays a pivotal role in many cellular functions, including cell senescence. Therefore, the aim of this study was to investigate whether senescence is more prominent in human degenerative CEP and whether SIRT1-regulated CEP cells senescence in degenerative IVD as well as identify the signaling pathways that control that cell fate decision. In this study, the cell senescence phenotype was found to be more prominent in the CEP cells obtained from disc degenerative disease (DDD) patients than in the CEP cells obtained from age-matched lumbar vertebral fractures (LVF) patients. In addition, the results indicated that p53/p21 pathway plays an important role in the senescence of CEP cells in vivo and vitro. Furthermore, SIRT1 was found to be capable of alleviating the oxidative stress-induced senescence of CEP cells in humans via p53/p21 pathway. Thus, the information presented in this study could be used to further investigate the underlying mechanisms of CEP.
GEM, a member of the GRAM domain family of proteins, is part of the ABA signaling pathway
Authors: Mauri Nuria , Fernández-Marcos María , Costas Celina , Desvoyes Bénédicte , Pichel Antonio , Caro Elena , Gutierrez Crisanto
Published: March 2016

Abscisic acid (ABA) is fundamental for plant development. Multiple factors have been identified that participate in the ABA signaling network, although a role of many proteins still await to be demonstrated. Here we have investigated the role of GEM (GL2 EXPRESSION MODULATOR), originally annotated as an ABA-responsive protein. GEM contains a GRAM domain, a feature shared with other eight Arabidopsis proteins for which we propose the name of GRE (GEM-RELATED) proteins. We found that (i) GEM expression responds to ABA, (ii) its promoter contains ABRE sites required for ABA response, and (iii) GEM expression depends on members of the ABA signaling pathway. This is consistent with the expression pattern of GEM during development in plant locations were ABA is known to play a direct role. We also found that GEM binds various phospholipids, e.g. mono and diphosphates and phosphatidic acid, suggesting a potential link of GEM with membrane-associated processes. Consistent with this, we found that the phosphoinositol-4-phosphate kinase PIP5K9 binds GEM in vivo. Finally, we demonstrated a role of GEM in seed dormancy. Together, our data led us to propose that GEM is an ABA-responsive protein that may function downstream of ABI5 as part of the ABA signaling pathway.
Long noncoding RNAs (lncRNAs) dynamics evidence immunomodulation during ISAV-Infected Atlantic salmon (Salmo salar)
Authors: Boltaña Sebastian , Valenzuela-Miranda Diego , Aguilar Andrea , Mackenzie Simon , Gallardo-Escárate Cristian
Published: March 2016

Despite evidence for participation in the host response to infection, the roles of many long non-coding RNAs (lncRNAs) remain unknown. Therefore, the aims of this study were to identify lncRNAs in Atlantic salmon (Salmo salar) and evaluate their transcriptomic regulation during ISA virus (ISAV) infection, an Orthomyxoviridae virus associated with high mortalities in salmonid aquaculture. Using next-generation sequencing, whole-transcriptome analysis of the Salmo salar response to ISAV infection was performed, identifying 5,636 putative lncRNAs with a mean length of 695 base pairs. The transcriptional modulation evidenced a similar number of differentially expressed lncRNAs in the gills (3,294), head-kidney (3,275) and liver (3,325) over the course of the infection. Moreover, analysis of a subset of these lncRNAs showed the following: (i) Most were similarly regulated in response to ISA virus infection; (ii) The transcript subsets were uniquely modulated in each tissue (gills, liver and head-kidney); and (iii) A subset of lncRNAs were upregulated for each tissue and time analysed, indicating potential markers for ISAV infection. These findings represent the first discovery of widespread differential expression of lncRNAs in response to virus infection in non-model species, suggesting that lncRNAs could be involved in regulating the host response during ISAV infection.
Multi-layer topological transmissions of spoof surface plasmon polaritons
Authors: Pan Bai Cao , Zhao Jie , Liao Zhen , Zhang Hao Chi , Cui Tie Jun
Published: March 2016

Spoof surface plasmon polaritons (SPPs) in microwave frequency provide a high field confinement in subwavelength scale and low-loss and flexible transmissions, which have been widely used in novel transmission waveguides and functional devices. To play more important roles in modern integrated circuits and systems, it is necessary and helpful for the SPP modes to propagate among different layers of devices and chips. Owing to the highly confined property and organized near-field distribution, we show that the spoof SPPs could be easily transmitted from one layer into another layer via metallic holes and arc-shaped transitions. Such designs are suitable for both the ultrathin and flexible single-strip SPP waveguide and double-strip SPP waveguide for active SPP devices. Numerical simulations and experimental results demonstrate the broadband and high-efficiency multi-layer topological transmissions with controllable absorption that is related to the superposition area of corrugated metallic strips. The transmission coefficient of single-strip SPP waveguide is no worse than −0.8 dB within frequency band from 2.67 GHz to 10.2 GHz while the transmission of double-strip SPP waveguide keeps above −1 dB within frequency band from 2.26 GHz to 11.8 GHz. The proposed method will enhance the realizations of highly complicated plasmonic integrated circuits.
Neonatal pneumococcal colonisation caused by Influenza A infection alters lung function in adult mice
Authors: FitzPatrick Meaghan , Royce Simon G. , Langenbach Shenna , McQualter Jonathan , Reading Patrick C. , Wijburg Odilia , Anderson Gary P. , Stewart Alastair , Bourke Jane , Bozinovski Steven
Published: March 2016

There is emerging epidemiological data to suggest that upper respiratory tract bacterial colonisation in infancy may increase the risk of developing respiratory dysfunction later in life and respiratory viruses are known to precipitate persistent colonisation. This study utilized a neonatal mouse model of Streptococcus pneumonia (SP) and influenza A virus (IAV) co-infection, where bronchoalveolar leukocyte infiltration had resolved by adulthood. Only co-infection resulted in persistent nasopharyngeal colonisation over 40 days and a significant increase in airway resistance in response to in vivo methacholine challenge. A significant increase in hysteresivity was also observed in IAV and co-infected mice, consistent with ventilatory heterogeneity and structural changes in the adult lung. Airway hyper-responsiveness was not associated with a detectable increase in goblet cell transdifferentiation, peribronchial smooth muscle bulk or collagen deposition in regions surrounding the airways. Increased reactivity was not observed in precision cut lung slices challenged with methacholine in vitro. Histologically, the airway epithelium appeared normal and expression of epithelial integrity markers (ZO-1, occludin-1 and E-cadherin) were not altered. In summary, neonatal co-infection led to persistent nasopharyngeal colonisation and increased airway responsiveness that was not associated with detectable smooth muscle or mucosal epithelial abnormalities, however increased hysteresivity may reflect ventilation heterogeneity.
Early diagnosis of myocardial infarction in clinic through CK-MB detection using magnetic separation integrated with chemiluminescence
Authors: Wang Dongyuan , Zhang Huisheng , Qi Suwen , Chen Wenwen
Published: March 2016

We present herein a simple, sensitive and specific method for CK-MB detection for the early diagnosis of myocardial infarction through magnetic separation integrated with chemiluminescence.
Ca(BH4)2–Mg2NiH4: on the pathway to a Ca(BH4)2 system with a reversible hydrogen cycle
Authors: Bergemann N. , Pistidda C. , Milanese C. , Emmler T. , Karimi F. , Chaudhary A.-L. , Chierotti M. R. , Klassen T. , Dornheim M.
Published: March 2016

The hydride composite Ca(BH4)2–Mg2NiH4 transfers all boron to MgNi2.5B2 upon dehydrogenation, avoiding boron sinks. The rehydrogenation to Ca(BH4)2 was confirmed.
Managing geologic CO2storage with pre-injection brine production: a strategy evaluated with a model of CO2injection at Snøhvit
Authors: Buscheck Thomas A. , White Joshua A. , Carroll Susan A. , Bielicki Jeffrey M. , Aines Roger D.
Published: March 2016

By removing brine from a reservoir prior to storing CO2, storage capacity can be increased by nearly an equivalent volume.
Apigenin ameliorates hypertension-induced cardiac hypertrophy and down-regulates cardiac hypoxia inducible factor-lα in rats
Authors: Zhu Zeng-Yan , Gao Tian , Huang Yan , Xue Jie , Xie Mei-Lin
Published: March 2016

Apigenin reduces cardiac hypertrophy and cardiac hypoxia inducible factor-lα in renovascular hypertensive rats.
Seedless, copper-induced synthesis of stable Ag/Cu bimetallic nanoparticles and their optical properties
Authors: Khan Zaheer , Obaid Abdullah Yousif
Published: March 2016

In this study, we demonstrate a sensitive and selective method for the seedless synthesis of Ag@Cu bimetallic nano-structured material based on the competitive coordination chemistry of cysteine with Cu2+ and Ag+.
Label-free fluorescence detection of microRNA based on target induced adenosine2–coralyne–adenosine2 formation
Authors: Li Jun-Jie , Xi Qiang , Du Wen-Fang , Yu Ru-Qin , Jiang Jian-Hui
Published: March 2016

This study presents a simple and label-free biosensor for sensitive and selective detection of microRNA based on the formation of the adenosine2–coralyne–adenosine2 complex in the presence of poly(A) polymerase and coralyne.
Sensitive and label-free T4 polynucleotide kinase/phosphatase detection based on poly(thymine)-templated copper nanoparticles coupled with nicking enzyme-assisted signal amplification
Authors: Ge Jia , Zhang Lin , Dong Zhen-Zhen , Cai Qi-Yong , Li Zhao-Hui
Published: March 2016

A novel label-free biosensor for highly sensitive sensing of the activity as well as inhibition of T4 PNKP based on poly T-templated fluorescent CuNPs and nicking enzyme-assisted signal amplification.
Convertible resistive switching characteristics between memory switching and threshold switching in a single ferritin-based memristor
Authors: Zhang Chaochao , Shang Jie , Xue Wuhong , Tan Hongwei , Pan Liang , Yang Xi , Guo Shanshan , Hao Jian , Liu Gang , Li Run-Wei
Published: March 2016

The coexistence and inter-conversion between threshold and memory resistance switching in a ferritin memristor makes it a promising candidate for physiological applications.
Fluorescence and photochromic properties of a series of new Zn(ii)/Cd(ii) coordination compounds with a flexible semi-rigid tetrazole–viologen derivative
Authors: Xiao Yu , Wang Shuai-Hua , Zhao Ya-Ping , Zheng Fa-Kun , Guo Guo-Cong
Published: March 2016

Diverse luminescence has been realized in four Zn(ii)/Cd(ii) coordination compounds. The isolated binuclear compound displays fluorescence and second-order nonlinear optical property variation in the photochromic process.
Density and structural anomalies in soft-repulsive dimeric fluids
Authors: Munaó Gianmarco , Saija Franz
Published: March 2016

We performed a simulation study of the fluid structure of dimeric particles interacting via a core-softened potential and shed light on their anomalous behaviours upon varying both geometrical and interaction parameters.
Origin of the step structure of molecular exchange–correlation potentials
Authors: Kohut Sviataslau V. , Polgar Alexander M. , Staroverov Viktor N.
Published: March 2016

The step structure of exact exchange–correlation potentials is linked to the properties of the average local electron energy (ALEE).
Paramagnetic dioxovanadium(iv) molecules inside the channels of zeolite BEA – EPR screening of VO2 reactivity toward small gas-phase molecules
Authors: Pietrzyk Piotr , Góra-Marek Kinga
Published: March 2016

Unusual VO2 radicals inside the channels of SiBEA are capable of electron and oxygen transfer in reactions with NO, N2O, CO, and O2 forming, i.e., reactive oxygen species.
A perfluoroaromatic abiotic analog of H2 relaxin enabled by rapid flow-based peptide synthesis
Authors: Lühmann Tessa , Mong Surin K. , Simon Mark D. , Meinel Lorenz , Pentelute Bradley L.
Published: March 2016

We report on the rapid-flow based synthesis and functional characterization of a H2 relaxin analog that takes advantage of perfluoroarylation-cysteine SNAr chemistry for a disulfide replacement strategy.
Pd nanoparticles modified rod-like nitrogen-doped ordered mesoporous carbons for effective catalytic hydrodechlorination of chlorophenols
Authors: Zhang Wei , Wang Fushan , Li Xinlin , Liu Yansheng , Ma Jiantai
Published: March 2016

The preparation of rod-like nitrogen-doped ordered mesoporous carbons (NOMCs) through a facial aqueous soft-template self-assembly route in one-pot is presented in this work.
Dynamic mechanical measurement of the viscoelasticity of single adherent cells
Authors: Corbin Elise A. , Adeniba Olaoluwa O. , Ewoldt Randy H. , Bashir Rashid
Published: March 2016

Many recent studies on the viscoelasticity of individual cells link mechanics with cellular function and health. Here, we introduce a measurement of the viscoelastic properties of individual human colon cancer cells (HT-29) using silicon pedestal microelectromechanical systems (MEMS) resonant sensors. We demonstrate that the viscoelastic properties of single adherent cells can be extracted by measuring a difference in vibrational amplitude of our resonant sensor platform. The magnitude of vibration of the pedestal sensor is measured using a laser Doppler vibrometer (LDV). A change in amplitude of the sensor, compared with the driving amplitude (amplitude ratio), is influenced by the mechanical properties of the adhered cells. The amplitude ratio of the fixed cells was greater than the live cells, with a p-value <0.0001. By combining the amplitude shift with the resonant frequency shift measure, we determined the elastic modulus and viscosity values of 100 Pa and 0.0031 Pa s, respectively. Our method using the change in amplitude of resonant MEMS devices can enable the determination of a refined solution space and could improve measuring the stiffness of cells.
Temperature varying photoconductivity of GeSn alloys grown by chemical vapor deposition with Sn concentrations from 4% to 11%
Authors: Hart John , Adam Thomas , Kim Yihwan , Huang Yi-Chiau , Reznicek Alexander , Hazbun Ramsey , Gupta Jay , Kolodzey James
Published: March 2016

Pseudomorphic GeSn layers with Sn atomic percentages between 4.5% and 11.3% were grown by chemical vapor deposition using digermane and SnCl4 precursors on Ge virtual substrates grown on Si. The layers were characterized by x-ray diffraction rocking curves and reciprocal space maps. Photoconductive devices were fabricated, and the dark current was found to increase with Sn concentration. The responsivity of the photoconductors was measured at a wavelength of 1.55 μm using calibrated laser illumination at room temperature and a maximum value of 2.7 mA/W was measured for a 4.5% Sn device. Moreover, the responsivity for higher Sn concentration was found to increase with decreasing temperature. Spectral photoconductivity was measured using Fourier transform infrared spectroscopy. The photoconductive absorption edge continually increased in wavelength with increasing tin percentage, out to approximately 2.4 μm for an 11.3% Sn device. The direct band gap was extracted using Tauc plots and was fit to a bandgap model accounting for layer strain and Sn concentration. This direct bandgap was attributed to absorption from the heavy-hole band to the conduction band. Higher energy absorption was also observed, which was thought to be likely from absorption in the light-hole band. The band gaps for these alloys were plotted as a function of temperature. These experiments show the promise of GeSn alloys for CMOS compatible short wave infrared detectors.
Current-perpendicular-to-plane giant magnetoresistive properties in Co2Mn(Ge0.75Ga0.25)/Cu2TiAl/Co2Mn(Ge0.75Ga0.25) all-Heusler alloy pseudo spin valve
Authors: Li S. , Takahashi Y. K. , Sakuraba Y. , Chen J. , Furubayashi T. , Mryasov O. , Faleev S. , Hono K.
Published: March 2016

Nonmagnetic Cu2TiAl (CTA) Heusler compound is proposed as a new spacer material for all-Heusler alloy current-perpendicular-to-plane giant magnetoresistance devices based on first-principle calculations. The (001)-orientated Co2Mn(Ge0.75Ga0.25) (CMGG)/CTA/CMGG epitaxial pseudo spin valve (PSV) grown on MgO(100) single crystal substrate showed relatively large MR output, ΔRA∼5.4 mΩ μm2, which is comparable to that of the CMGG/Ag/CMGG PSV prepared with the same condition. Considering the short spin diffusion length in CTA, this result indicates a better electronic band matching for the CTA/CMGG interface than the Ag/CMGG interface in agreement with the first-principle calculation results. (001)- and (011)-orientated CMGG/CTA/CMGG PSV show similar MR outputs, indicating that the CTA spacer suppresses the orientation dependence of MR output which is usually observed in Ag-spacer CPP-PSV.
Early stage of nanodroplet impact on solid wall
Authors: Kobayashi Kazumichi , Konno Kazuki , Yaguchi Hisao , Fujii Hiroyuki , Sanada Toshiyuki , Watanabe Masao
Published: March 2016

In this study, we investigated nanodroplet spreading at the early stage after the impact using molecular dynamics simulations by changing the magnitude of the intermolecular force between the liquid and wall molecules. We showed that the droplet deformation after the impact greatly depends on the intermolecular force. The temporal evolution of the spreading diameters was measured by the cylindrical control volume for several molecular layers in the vicinity of the wall. At the early stage of the nanodroplet impact, the normalized spreading radius of the droplet is proportional to the square root of the normalized time, tˆ. This result is understood by the geometrical consideration presented by Rioboo et al. [“Time evolution of liquid drop impact onto solid, dry surfaces,” Exp. Fluids 33, 112–124 (2002)]. In addition, we found that as the intermolecular force between the liquid and wall becomes stronger, the normalized spreading diameter of the first molecular layer on the wall remains less dependent on the impact velocity. Furthermore, the time evolution of the droplet spreading changes from tˆ to logtˆ with time.
Statistical characteristic in time-domain of direct current corona-generated audible noise from conductor in corona cage
Authors: Li Xuebao , Cui Xiang , Lu Tiebing , Ma Wenzuo , Bian Xingming , Wang Donglai , Hiziroglu Huseyin
Published: March 2016

The corona-generated audible noise (AN) has become one of decisive factors in the design of high voltage direct current (HVDC) transmission lines. The AN from transmission lines can be attributed to sound pressure pulses which are generated by the multiple corona sources formed on the conductor, i.e., transmission lines. In this paper, a detailed time-domain characteristics of the sound pressure pulses, which are generated by the DC corona discharges formed over the surfaces of a stranded conductors, are investigated systematically in a laboratory settings using a corona cage structure. The amplitude of sound pressure pulse and its time intervals are extracted by observing a direct correlation between corona current pulses and corona-generated sound pressure pulses. Based on the statistical characteristics, a stochastic model is presented for simulating the sound pressure pulses due to DC corona discharges occurring on conductors. The proposed stochastic model is validated by comparing the calculated and measured A-weighted sound pressure level (SPL). The proposed model is then used to analyze the influence of the pulse amplitudes and pulse rate on the SPL. Furthermore, a mathematical relationship is found between the SPL and conductor diameter, electric field, and radial distance.
In situ measurement of the two-dimensional temperature field of a dual-jet direct-current arc plasma
Authors: Guo Heng , Li Peng , Li He-Ping , Ge Nan , Bao Cheng-Yu
Published: March 2016

In this paper, a real time method for an in situ measurement of the two-dimensional (2-D) temperature filed of thermal plasmas is developed with the combination of the visible image processing technique and the spectroscopic line-ratio method at two specified wavelengths. After the calibration of the gray scale values of the recorded images with the CCD cameras by the emission intensity received using a spectrometer, the 2-D temperature field of the plasma arc-jet can be obtained conveniently based on the derived gray scale values of the CCD images at two specified wavelengths and the formula similar to that of spectroscopic line-ratio method. The experimental results show that the obtained temperature fields of the plasma arc-jet at different times are qualitatively reasonable and consistent with the modeling result. This newly developed method can be employed to measure the transient temperature fields of the plasmas with fluctuations during discharges effectively.
Open water bells
Authors: Paramati Manjula , Tirumkudulu Mahesh S.
Published: March 2016

A smooth circular moving liquid sheet is formed by the head-on impingement of two equal laminar water jets. We subject such a liquid sheet to uniform laminar air flow from one side such that the direction of air velocity is perpendicular to the liquid sheet. The pressure of the moving air deforms the liquid sheet giving rise to an open water bell. The water bell is symmetric suggesting that the gas flow around the bell is also symmetric and that the gravitational force is negligible. We have captured the shape of the water bells for varying air flow rates and for varying Weber numbers, and compared the measurements with theoretical predictions obtained from a force balance involving liquid inertia, surface tension, and pressure difference across the sheet. The pressure exerted by the gas phase on the front and the rear surface of the deformed liquid sheet is obtained from known results of flow past flat circular discs. The predicted steady state shapes match well with the measurements at low Weber numbers but differences are observed at high Weber numbers, where the sheet flaps and is no longer smooth. Interestingly, the shape predicted by assuming a constant pressure difference equal to the stagnation pressure over the whole of the front face of the sheet and free stream value over the whole of the rear face yields nearly identical results suggesting that an open water bell is similar to a closed water bell in that, to a good approximation, the pressure on either sides of the water bell is homogeneous.
Morphologically manipulated Ag/ZnO nanostructures as surface enhanced Raman scattering probes for explosives detection
Authors: Shaik Ummar Pasha , Hamad Syed , Ahamad Mohiddon Md. , Soma Venugopal Rao , Ghanashyam Krishna M.
Published: March 2016

The detection of secondary explosive molecules (e.g., ANTA, FOX-7, and CL-20) using Ag decorated ZnO nanostructures as surface enhanced Raman scattering (SERS) probes is demonstrated. ZnO nanostructures were grown on borosilicate glass substrates by rapid thermal oxidation of metallic Zn films at 500 °C. The oxide nanostructures, including nanosheets and nanowires, emerged over the surface of the Zn film leaving behind the metal residue. We demonstrate that SERS measurements with concentrations as low as 10 μM, of the three explosive molecules ANTA, FOX-7, and CL-20 over ZnO/Ag nanostructures, resulted in enhancement factors of ∼107, ∼107, and ∼104, respectively. These measurements validate the high sensitivity of detection of explosive molecules using Ag decorated ZnO nanostructures as SERS substrates. The Zn metal residue and conditions of annealing play an important role in determining the detection sensitivity.
Interaction of surface plasmon polaritons in heavily doped GaN microstructures with terahertz radiation
Authors: Melentev G. A. , Shalygin V. A. , Vorobjev L. E. , Panevin V. Yu. , Firsov D. A. , Riuttanen L. , Suihkonen S. , Korotyeyev V. V. , Lyaschuk Yu. M. , Kochelap V. A. , Poroshin V. N.
Published: March 2016

We present the results of experimental and theoretical studies of the surface plasmon polariton excitations in heavily doped GaN epitaxial layers. Reflection and emission of radiation in the frequency range of 2–20 THz including the Reststrahlen band were investigated for samples with grating etched on the sample surface, as well as for samples with flat surface. The reflectivity spectrum for p-polarized radiation measured for the sample with the surface-relief grating demonstrates a set of resonances associated with excitations of different surface plasmon polariton modes. Spectral peculiarities due to the diffraction effect have been also revealed. The characteristic features of the reflectivity spectrum, namely, frequencies, amplitudes, and widths of the resonance dips, are well described theoretically by a modified technique of rigorous coupled-wave analysis of Maxwell equations. The emissivity spectra of the samples were measured under epilayer temperature modulation by pulsed electric field. The emissivity spectrum of the sample with surface-relief grating shows emission peaks in the frequency ranges corresponding to the decay of the surface plasmon polariton modes. Theoretical analysis based on the blackbody-like radiation theory well describes the main peculiarities of the observed THz emission.
Multi-dimensional dynamics of stimulated Brillouin scattering in a laser speckle: Ion acoustic wave bowing, breakup, and laser-seeded two-ion-wave decay
Authors: Albright B. J. , Yin L. , Bowers K. J. , Bergen B.
Published: March 2016

Two- and three-dimensional particle-in-cell simulations of stimulated Brillouin scattering (SBS) in laser speckle geometry have been analyzed to evaluate the relative importance of competing nonlinear processes in the evolution and saturation of SBS. It is found that ion-trapping-induced wavefront bowing and breakup of ion acoustic waves (IAW) and the associated side-loss of trapped ions dominate electron-trapping-induced IAW wavefront bowing and breakup, as well as the two-ion-wave decay instability over a range of ZTe/Ti conditions and incident laser intensities. In the simulations, the latter instability does not govern the nonlinear saturation of SBS; however, evidence of two-ion-wave decay is seen, appearing as a modulation of the ion acoustic wavefronts. This modulation is periodic in the laser polarization plane, anti-symmetric across the speckle axis, and of a wavenumber matching that of the incident laser pulse. A simple analytic model is provided for how spatial “imprinting” from a high frequency inhomogeneity (in this case, the density modulation from the laser) in an unstable system with continuum eigenmodes can selectively amplify modes with wavenumbers that match that of the inhomogeneity.
Importance of hydrophobic traps for proton diffusion in lyotropic liquid crystals
Authors: McDaniel Jesse G. , Yethiraj Arun
Published: March 2016

The diffusion of protons in self-assembled systems is potentially important for the design of efficient proton exchange membranes. In this work, we study proton dynamics in a low-water content, lamellar phase of a sodium-carboxylate gemini surfactant/water system using computer simulations. The hopping of protons via the Grotthuss mechanism is explicitly allowed through the multi-state empirical valence bond method. We find that the hydronium ion is trapped on the hydrophobic side of the surfactant-water interface, and proton diffusion then proceeds by hopping between surface sites. The importance of hydrophobic traps is surprising because one would expect the hydronium ions to be trapped at the charged headgroups. The physics illustrated in this system should be relevant to the proton dynamics in other amphiphilic membrane systems, whenever there exist exposed hydrophobic surface regions.
Insight on the surface polarisation for non-blocking electrodes
Authors: de Andrade T. , Alexe-Ionescu A. L. , Saracco G. , Barbero G.
Published: March 2016

A complete phenomenological description of the electrode polarisation and of the non-blocking character of electrodes is theoretically discussed. To do this, the role of the ions on the electrical response of an electrolytic cell submitted to an external field of small amplitude is investigated. We assume that the conduction current across the electrodes is limited by energy barriers which determine the activation energy of the corresponding electrochemical reactions responsible for the processes of charge transfer between the solution containing ions and the external circuit. This assumption implies that the boundary conditions for the conduction current on the electrodes contain two terms: one proportional to the surface electric field, as in the Ohmic model, and the other proportional to the surface variation of the bulk concentration of ions, as in the Chang-Jaffe model. We deduce, in the one-mobile ion approximation, the expression for the electric impedance of the cell, in the shape of a slab, for mixed boundary conditions. Our expression contains, as particular cases, the Ohmic and Chang-Jaffe models. The equivalence between the general case considered in our analysis and previous models is discussed.
Pulsed laser deposition of single layer, hexagonal boron nitride (white graphene, h-BN) on fiber-oriented Ag(111)/SrTiO3(001)
Authors: Velázquez Daniel , Seibert Rachel , Man Hamdi , Spentzouris Linda , Terry Jeff
Published: March 2016

We report on the growth of 1–10 ML films of hexagonal boron nitride (h-BN), also known as white graphene, on fiber-oriented Ag buffer films on SrTiO3(001) by pulsed laser deposition. The Ag buffer films of 40 nm thickness were used as substitutes for expensive single crystal metallic substrates. In-situ, reflection high-energy electron diffraction was used to monitor the surface structure of the Ag films and to observe the formation of the characteristic h-BN diffraction pattern. Further evidence of the growth of h-BN was provided by attenuated total reflectance spectroscopy, which showed the characteristic h-BN peaks at ∼780 cm−1 and 1367.4 cm−1. Ex-situ photoelectron spectroscopy showed that the surface of the h-BN films is stoichiometric. The physical structure of the films was confirmed by scanning electron microscopy. The h-BN films grew as large, sub-millimeter sheets with nano- and micro-sheets scattered on the surface. The h-BN sheets can be exfoliated by the micromechanical adhesive tape method. Spectral analysis was performed by energy dispersive spectroscopy in order to identify the h-BN sheets after exfoliation. The use of thin film Ag allows for reduced use of Ag and makes it possible to adjust the surface morphology of the thin film prior to h-BN growth.
Characterization of background carriers in InAs/GaSb quantum well
Authors: Li Junbin , Wu Xiaoguang , Wang Guowei , Xu Yingqiang , Niu Zhichuan , Zhang Xinhui
Published: March 2016

The origin of the background carriers in an undoped InAs/GaSb quantum well (QW) at temperatures between 40 K and 300 K has been investigated using conventional Hall measurements. It is found that the Hall coefficient changes its sign at around 200 K, indicating that both electrons and holes exist in the quantum well. The two-carrier Hall model is thus adopted to analyze the Hall data, which enables the temperature dependence of the carrier density to be obtained. It is found that considerable numbers of holes exist under low temperature conditions (<40 K) in the InAs/GaSb QW, and the hole density is one to two orders higher than that of the electrons within the experimental temperature range. The origin of these low temperature holes and the temperature-dependent behavior of the carrier density over the entire experimental temperature range are then discussed.
Soil protection in solar photovoltaic farms by revegetation with mycorrhizal native species
Authors: Ormeño Mónica Sánchez , Hervás Sara , Amorós José Ángel , Navarro Francisco Jesús García , Gallego Juan Campos , Pérez-de-los-Reyes Caridad
Published: March 2016

The installation of a photovoltaic solar farm involves modification of the original soil properties, which can be compensated for by revegetation of a proportion of the surface of the installation with native plants. Mycorrhizal plants can be used in the revegetation process because these plants are known to increase the structural stability of degraded soils and improve natural vegetation cover, thus increasing both survival and growth of the species, especially in semi-arid areas. The aim of the present study was to analyse mycorrhizal colonisation of native species to ensure success of revegetation in solar photovoltaic farms in Mediterranean areas. The present study was performed in the field because most studies on mycorrhizal species have been conducted in a controlled nursery environment. Four species were planted (Cistus monspeliensis L., Lavandula stoechas L., Thymus vulgaris L. and Rosmarinus officinalis L.) with inoculated and non-inoculated plants. Once the percentage of mycorrhizal colonisation of inoculated plants was known, the survival percentage and apical growth were determined over 2 years. The mycorrhizal colonisation of inoculated plants was satisfactory at the end of the study period, although there was a natural colonisation of mycorrhizae in plants that initially had not been inoculated. Lavandula stoechas L. had the highest survival percentage (95.8% in mycorrhizal plants and 100% in non-mycorrhizal plants) and Rosmarinus officinalis L. had the highest apical growth (19 cm in mycorrhizal plants and 15.2 cm in non-mycorrhizal plants). The species factor had a significant effect on survival percentage and apical growth of the species studied.
Thomas Becket and the Royal Abbey of Reading
Authors: Koopmans Rachel
Published: March 2016

Drawing on a wide variety of evidence, including letters, charters, indulgences, poems, miracle stories, relic lists, and a stained-glass panel in Canterbury Cathedral, this essay examines how the monks of Reading Abbey reacted to the controversy between King Henry II and Thomas Becket in the late 1160s and the beginning of Becket’s cult in the 1170s and 1180s. Reading Abbey was founded and richly endowed by Henry II’s grandfather, Henry I. William the Templar, abbot of Reading from 1168–73, was, unsurprisingly, on the side of Henry II and Becket’s opponents. The sympathies of the prior of Reading and of at least one Reading monk, however, were with Becket’s supporters. After Becket’s death, this dissension continued. Abbot William banned pilgrimage to Canterbury, orders that his monks circumvented. Abbot William’s successor, Abbot Joseph (1173–86), had a very different outlook. He promoted Becket’s cult to an extraordinary degree, despite the fact that Reading Abbey was in possession of an important relic, the Hand of St James, which had been placed at Reading by the king himself. The story of Reading Abbey’s relationship with Thomas Becket provides new perspectives on the factionalism triggered by the Becket controversy, the strength of Becket’s early cult, and the devotional history of a major English Benedictine abbey.
Added Value of Long-Term Cytokine Release Assays to Detect Mycobacterium tuberculosis Infection in HIV-Infected Subjects in Uganda
Authors: Dirix Violette , Schepers Kinda , Massinga-Loembe Marguerite , Worodria William , Colebunders Robert , Singh Mahavir , Locht Camille , Kestens Luc , Mascart Françoise ,   TB-IRIS study group
Published: March 2016

Objectives:

To investigate whether mycobacterial antigen–induced cytokine secretions are helpful in detecting Mycobacterium tuberculosis (Mtb) infection in a cohort of HIV-infected patients living in a country with a high burden of Mtb and HIV infections, and to determine their predictive value for the development of tuberculosis (TB)-associated immune reconstitution inflammatory syndrome.

Design:

A total of 352 HIV-infected patients (186 with active TB) were prospectively enrolled when initiating antiretroviral therapy (ART). Sequential blood samples were collected during the first 6 months of ART. Eighty-three HIV-uninfected subjects (39 with active TB) were enrolled as controls.

Methods:

The concentrations of 13 cytokines were measured in supernatants from blood mononuclear cells in vitro stimulated with purified protein derivative (PPD), heparin-binding hemagglutinin (HBHA) or early secreted antigen-6 (ESAT-6) and culture filtrate protein-10 (CFP-10), and results were compared with those of tuberculin skin tests (TST).

Results:

The best detection of Mtb infection was achieved by ESAT-6/CFP-10–induced interferon-γ concentrations, but results were often negative for patients with CD4+ T-cell counts <50 per cubic millimeters. Patients with active TB were identified by high ESAT-6/CFP-10–induced interleukin-6. Conversions of interferon-γ-release assays (IGRA) and TST occurred under ART, and combined TB and antiretroviral treatments of coinfected patients resulted in a decrease of ESAT-6/CFP-10–induced and an increase of HBHA-induced interferon-γ responses. No Mtb antigen–induced cytokines allowed us to predict TB–immune reconstitution inflammatory syndrome or ART-associated TB.

Conclusions:

In Uganda, ESAT-6/CFP-10–IGRA is better in detecting Mtb infection than TST and, when combined with an HBHA–IGRA, could help to evaluate anti-TB treatment success.
The regulator-executor-phenotype architecture shaped by natural selection
Authors: Chen Han , Wu Chung-I , He Xionglei
Published: March 2016

The genotype-phenotype relationships are a central focus of modern genetics. While deletion analyses have uncovered many regulatory genes of specific traits, it remains largely unknown how these regulators execute their commands through downstream genes, or executors. Here, we wish to know the number of executors for each trait, their relationships with the regulators and the role natural selection may play in shaping the regulator-executor-phenotype architecture. By analyzing ∼500 morphological traits of the yeastSaccharomyces cerevisiaewe found that a trait is often controlled directly by a large number of executors, the expressions of which are affected by regulators. By recruiting a set of “coordinating” regulators, natural selection helps organize the large number of executors into a small number of co-expression modules. This way, the individual executors can be readily recognized by observational approaches that examine the statistical association between gene activity and trait. When the trait is subject to little or no selection, however, the executors are controlled only by “non-coordinating” regulators that evolve passively and do not build the executors’ co-expression. As a result, none of the executors remain a statistically tractable relationship with the trait. Thus, natural selection by governing some traits strongly (such as fertility) and others weakly (such as aging-related phenotypes) profoundly influences the genotype-phenotype relationships as well as their tractability.