bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolutionary paths among different red galaxy types at 0.3 < z < 1.5 and the build-up of massive E-S0's
Authors: Gallego Jesús , Prieto Mercedes , Eliche-Moral M. Carmen , Balcells Marc , Cristóbal-Hornillos David , Erwin Peter , Abreu David , Domínguez-Palmero Lilian , Hempel Angela , López-Sanjuan Carlos , Guzmán Rafael , Pérez-González Pablo G. , Barro Guillermo , Zamorano Jaime
Published: July 2013

Some recent observations seem to disagree with hierarchical theories of galaxy formation on the role of major mergers in a late build-up of massive early-type galaxies. We re-address this question by analysing the morphology, structural distortion level, and star formation enhancement of a sample of massive galaxies (M* > 5 × 1010M⊙) lying on the Red Sequence and its surroundings at 0.3 < z < 1.5. We have used an initial sample of ~1800 sources with Ks < 20.5 mag over an area ~155 arcmin2 on the Groth Strip, combining data from the Rainbow Extragalactic Database and the GOYA Survey. Red galaxy classes that can be directly associated to intermediate stages of major mergers and to their final products have been defined. For the first time we report observationally the existence of a dominant evolutionary path among massive red galaxies at 0.6 < z < 1.5, consisting in the conversion of irregular disks into irregular spheroids, and of these ones into regular spheroids. This result points to: 1) the massive red regular galaxies at low redshifts derive from the irregular ones populating the Red Sequence and its neighbourhood at earlier epochs up to z ~ 1.5; 2) the progenitors of the bulk of present-day massive red regular galaxies have been blue disks that have migrated to the Red Sequence majoritarily through major mergers at 0.6 < z < 1.2 (these mergers thus starting at z ~ 1.5); 3) the formation of E-S0's that end up with M* > 1011M⊙ at z = 0 through gas-rich major mergers has frozen since z ~ 0.6. Our results support that major mergers have played the dominant role in the definitive build-up of present-day E-S0's with M* > 1011M⊙ at 0.6 < z < 1.2, in good agreement with the hierarchical scenario proposed in the Eliche-Moral et al. (2010a) model (see also Eliche-Moral et al. 2010b). This study is published in Prieto et al. (2012).

Supported by the Spanish Ministry of Science and Innovation (MICINN) under projects AYA2009-10368, AYA2006-12955, AYA2010-21887-C04-04, and AYA2009-11137, by the Madrid Regional Government through the AstroMadrid Project (CAM S2009/ESP-1496), and by the Spanish MICINN under the Consolider-Ingenio 2010 Program grant CSD2006-00070: “First Science with the GTC” (http://www.iac.es/consolider-ingenio-gtc/). S. D. H. & G.
Satellites of massive galaxies: the infalling pieces of the puzzle
Authors: Mármol-Queraltó E. , Trujillo I. , Pérez-González P. G. , Barro G. , Varela J. , Villar V.
Published: July 2013

Accretion of minor satellites has been postulated as the most likely mechanism to explain the significant size evolution of massive galaxies over cosmic time. A direct way of probing this scenario is to measure the frequency of satellites around massive galaxies at different redshifts. Here we present our study of satellites around massive galaxies (Mstar ~ 1011 M⊙) up to z ~ 2. We find (Fig. 1) that the fraction of massive galaxies with satellites down to 1:10 mass ratio is ~15% (~30% down to 1:100), not varying with redshift (Mármol-Queraltó et al., (2012)). We also find that our satellites are younger than their central galaxies at low z (Mármol-Queraltó et al., 2013). Then, if minor merging is acting to form massive galaxies, their ourtskirts should be younger than their cores. The challenge to find this age gradient in nearby massive galaxies is opened.
The evolution of massive galaxies in semi-analytical models of galaxy formation
Authors: Baugh Carlton M.
Published: July 2013

Massive galaxies with old stellar populations have been put forwards as a challenge to models in which cosmic structures grow hierarchically through gravitational instability. I will explain how the growth of massive galaxies is helped by features of hierarchical models. I give a brief outline of how the galaxy formation process is modelled in hierarchical cosmologies using semi-analytical models, and illustrate how these models can be refined as our understanding of processes such as star formation improves. I then present a brief survey of the current state of play in the modelling of massive galaxies and list some outstanding challenges.
Structural evolution of massive early-type galaxies
Authors: Oser Ludwig , Naab Thorsten , Ostriker Jeremiah P. , Johansson Peter H.
Published: July 2013

We use a large sample of cosmological re-simulations of individual massive galaxies to investigate the origin of the strong increase in sizes and weak decrease of the stellar velocity dispersions since z = 2. At the end of a rapid early phase of star-formation, where stars are created from infalling cold gas, our simulated galaxies are all compact with projected half-mass radii of ≲ 1 kpc and central line-of-sight velocity dispersions of ≈ 262 km s−1. At lower redshifts (z < 2) those galaxies grow predominantly by the accretion of smaller stellar systems and evolve towards the observed local mass-size and mass-velocity dispersion relations. This loss of compactness is accompanied with an increase of central dark matter fractions. We find that the structural evolution of massive galaxies can be explained by frequent minor stellar mergers, which is the dominant mode of accretion for our simulated galaxies.
The XLENS Project: Do More Massive Early-Type Galaxies Have More Dark Matter or Different Stellar IMFs?
Authors: Spiniello Chiara
Published: July 2013

The X-shooter Lens Survey (XLENS) aims to study the interplay of dark matter (DM) and stellar content in the inner regions of massive early-type galaxies (ETGs) by combining strong gravitational lensing, dynamical models, and spectroscopic stellar population analysis. XLENS targets a sample of ETGs from the SLACS survey (The Sloan Lens ACS Survey, e.g. Bolton et al. 2006) with velocity dispersions ≥250 kms−1 using the X-Shooter spectrograph on ESO's Very Large Telescope. Recent observations indicate that the internal dark-matter fraction of ETGs increases rapidly with galaxy mass, although some hints for a varying initial mass function (IMF) have also been suggested, where the low-mass end of the stellar IMF steepens with galaxy mass. XLENS first results unambiguously confirm that DM plays an important role already within one effective radius for very massive systems (Spiniello et al. 2011). Moreover, studying equivalent widths of certain red spectral features which are indicators of low-mass stars in massive ETGs (e.g. NaI and TiO2) as a function of age and metallicity (i.e. Mgb, Fe, Hβ), and as function of stellar velocity dispersion, has shown that the IMF slope is varying mildly with galaxy mass (Spiniello et al. 2012).
Strong Lenses With Single Images
Authors: Shu Yiping , Bolton Adam S. , Brownstein Joel R. ,   the SLACS Collaborations
Published: July 2013

SLACS for the masses is the extension of the successful Sloan Lens ACS (SLACS) survey (Bolton et al. 2006, Treu et al. 2006, Koopmans et al. 2006, Gavazzi et al. 2007 and Bolton et al. 2008) but focuses on the lower-mass end of elliptical galaxies (EGs) to yield a more complete strong-lens sample. As to date, 118 out of the 137 proposed candidates have been observed and inspected individually.
Local group analogues – searching for the satellites of the nearest massive galaxies
Authors: Speller Ryan , Taylor James E.
Published: July 2013

We have performed a search for faint companions around the nearest massive galaxies. We see a clear signature of clustering of faint objects, both in projected separation and in velocity offset. The inferred satellite luminosity functions confirm that the abundance of faint satellites seen in the Local Group is typical of other nearby systems.
Fluorescence in the Active Galactic Nuclei NGC 4151
Authors: Eriksson Mattias , Veenhuizen Hans
Published: July 2013

The possibility of UV lines from Fe II formed in the BLR of NGC 4151 has been examined. As a result Fe II emission has been shown to play an important role for the topology of the 2000 to 3000 Å wavelength region of the NGC 4151 spectra. The Fe II UV emission originates from two processes, collisional excitation and PAR (photoexcitation by accidental resonance).
The LF of TP-AGB stars in the LMC/SMC
Authors: Bruzual Gustavo , Charlot Stéphane , Lópezlira Rosa González , Srinivasan Sundar , Boyer Martha L. , Riebel David
Published: July 2013

We show that Monte Carlo simulations of the TP-AGB stellar population in the LMC and SMC galaxies using the CB* models produce LF and color distributions that are in closer agreement with observations than those obtained with the BC03 and CB07 models. This is a progress report of work that will be published elsewhere.
Bayesian analysis of galaxy spectral energy distributions with BayeSED
Authors: Han Yunkun , Han Zhanwen
Published: July 2013

In Han & Han (2012), we have preliminarily built BayeSED and applied it to a sample of hyperluminous infrared galaxies. The physically reasonable results obtained from Bayesian model comparison and parameter estimation show that BayeSED could be a useful tool for understanding the nature of complex systems, such as dust obscured starburst-AGN composite galaxies, from decoding their complex SEDs. In this contribution, we present a more rigorous test of BayeSED by making a mock catalog from model SEDs with the value of all parameters to be known in advance.
A star cluster view of the life of massive galaxies
Authors: Lee Myung Gyoon , Park Hong Soo
Published: July 2013

We present an overview of recent findings on the kinematics, age, and metallicity of globular cluster systems in nearby giant elliptical galaxies and their implications for understanding how giant elliptical galaxies formed and evolved.
The stellar populations of host galaxies of supernovae
Authors: Shao X. , Liang Y. C. , Dennefeld M. , Chen X. Y. , Zhong G. H. , Hammer F. , Deng L. C. , Zhang B.
Published: July 2013

We study and compare the stellar populations of host galaxies of different types of supernovae (SNe): SN Ia and core collapse SN (SN II and SN Ibc) at the same time. The 234 sample galaxies are selected by cross-matching the Asiago Supernova Catalogue (ASC) and the SDSS-DR7 main galaxy sample (MGS). The STARLIGHT software is used to analyze their stellar populations by fitting the continua and absorption lines of the hosts.
The [NII]/Hα calibration of the metallicity of galaxies from Te-based abundances
Authors: Liang Yanchun , Shao Xu , Hammer Francois , Yin Shaoying
Published: July 2013

We gather a sample of both metal-rich and metal-poor galaxies. Both samples have oxygen abundances estimated from electron temperature (Te). The calibration of the emission-line ratio, N2(≡log([NII]6583/Hα), to oxygen abundances is then re-derived from this combined sample, finding good agreement for the wide metallicity and line-ratio ranges considered.
The Intriguing Life of Massive Galaxies: Introducing the Final Discussion
Authors: Renzini Alvio
Published: July 2013

This is a brief introduction to the closing discussion of the IAU Symposium 295, ‘The Intriguing Life of Massive Galaxies’, that was held in Beijing from August 27 through 31, 2012. The discussion was focused on only four hot items, namely 1) the redshift evolution of the size of passively evolving galaxies, 2) the evolution with redshift of the specific star formation rate, 3) quenching of star formation in galaxies and dry merging, and 4) the IMF.
TNF-α Induces Phenotypic Modulation in Cerebral Vascular Smooth Muscle Cells: Implications for Cerebral Aneurysm Pathology
Authors: Ali Muhammad S , Starke Robert M , Jabbour Pascal M , Tjoumakaris Stavropoula I , Gonzalez L Fernando , Rosenwasser Robert H , Owens Gary K , Koch Walter J , Greig Nigel H , Dumont Aaron S
Published: July 2013

Little is known about vascular smooth muscle cell (SMC) phenotypic modulation in the cerebral circulation or pathogenesis of intracranial aneurysms. Tumor necrosis factor-alpha (TNF-α) has been associated with aneurysms, but potential mechanisms are unclear. Cultured rat cerebral SMCs overexpressing myocardin induced expression of key SMC contractile genes (SM-α-actin, SM-22α, smooth muscle myosin heavy chain), while dominant-negative cells suppressed expression. Tumor necrosis factor-alpha treatment inhibited this contractile phenotype and induced pro-inflammatory/matrix-remodeling genes (monocyte chemoattractant protein-1, matrix metalloproteinase-3, matrix metalloproteinase-9, vascular cell adhesion molecule-1, interleukin-1 beta). Tumor necrosis factor-alpha increased expression of KLF4, a known regulator of SMC differentiation. Kruppel-like transcription factor 4 (KLF4) small interfering RNA abrogated TNF-α activation of inflammatory genes and suppression of contractile genes. These mechanisms were confirmed in vivo after exposure of rat carotid arteries to TNF-α and early on in a model of cerebral aneurysm formation. Treatment with the synthesized TNF-α inhibitor 3,6-dithiothalidomide reversed pathologic vessel wall alterations after induced hypertension and hemodynamic stress. Chromatin immunoprecipitation assays in vivo and in vitro demonstrated that TNF-α promotes epigenetic changes through KLF4-dependent alterations in promoter regions of myocardin, SMCs, and inflammatory genes. In conclusion, TNF-α induces phenotypic modulation of cerebral SMCs through myocardin and KLF4-regulated pathways. These results demonstrate a novel role for TNF-α in promoting a pro-inflammatory/matrix-remodeling phenotype, which has important implications for the mechanisms behind intracranial aneurysm formation.
Influence of a priori Information, Designs, and Undetectable Data on Individual Parameters Estimation and Prediction of Hepatitis C Treatment Outcome
Authors: Nguyen THT , Guedj J , Yu J , Levi M , Mentré F
Published: July 2013

Hepatitis C viral kinetic analysis based on nonlinear mixed effect models can be used to individualize treatment. For that purpose, it is necessary to obtain precise estimation of individual parameters. Here, we evaluated by simulation the influence on Bayesian individual parameter estimation and outcome prediction of a priori information on population parameters, viral load sampling designs, and methods for handling data below detection limit (BDL). We found that a precise estimation of both individual parameters and treatment outcome could be obtained using as few as six measurements in the first month of therapy. This result remained valid even when incorrect a priori information on population parameters was set as long as the parameters were identifiable and BDL data were properly handled. However, setting wrong values for a priori population parameters could lead to severe estimation/prediction errors if BDL data were ignored and not properly accounted in the likelihood function.

CPT: Pharmacometrics & Systems Pharmacology (2013) 2, e56; doi:10.1038/psp.2013.31; published online 17 July 2013
Modeling and Validating Chronic Pharmacological Manipulation of Circadian Rhythms
Authors: Kim JK , Forger DB , Marconi M , Wood D , Doran A , Wager T , Chang C , Walton KM
Published: July 2013

Circadian rhythms can be entrained by a light‐dark (LD) cycle and can also be reset pharmacologically, for example, by the CK1δ/ε inhibitor PF‐670462. Here, we determine how these two independent signals affect circadian timekeeping from the molecular to the behavioral level. By developing a systems pharmacology model, we predict and experimentally validate that chronic CK1δ/ε inhibition during the earlier hours of a LD cycle can produce a constant stable delay of rhythm. However, chronic dosing later during the day, or in the presence of longer light intervals, is not predicted to yield an entrained rhythm. We also propose a simple method based on phase response curves (PRCs) that predicts the effects of a LD cycle and chronic dosing of a circadian drug. This work indicates that dosing timing and environmental signals must be carefully considered for accurate pharmacological manipulation of circadian phase.

CPT: Pharmacometrics & Systems Pharmacology (2013) 2, e57; doi:10.1038/psp.2013.34; published online 17 July 2013
Solvation dynamics of tryptophan in water-dimethyl sulfoxide binary mixture: In search of molecular origin of composition dependent multiple anomalies
Authors: Roy Susmita , Bagchi Biman
Published: July 2013

Experimental and simulation studies have uncovered at least two anomalous concentration regimes in water-dimethyl sulfoxide (DMSO) binary mixture whose precise origin has remained a subject of debate. In order to facilitate time domain experimental investigation of the dynamics of such binary mixtures, we explore strength or extent of influence of these anomalies in dipolar solvation dynamics by carrying out long molecular dynamics simulations over a wide range of DMSO concentration. The solvation time correlation function so calculated indeed displays strong composition dependent anomalies, reflected in pronounced non-exponential kinetics and non-monotonous composition dependence of the average solvation time constant. In particular, we find remarkable slow-down in the solvation dynamics around 10%-20% and 35%-50% mole percentage. We investigate microscopic origin of these two anomalies. The population distribution analyses of different structural morphology elucidate that these two slowing down are reflections of intriguing structural transformations in water-DMSO mixture. The structural transformations themselves can be explained in terms of a change in the relative coordination number of DMSO and water molecules, from 1DMSO:2H2O to 1H2O:1DMSO and 1H2O:2DMSO complex formation. Thus, while the emergence of first slow down (at 15% DMSO mole percentage) is due to the percolation among DMSO molecules supported by the water molecules (whose percolating network remains largely unaffected), the 2nd anomaly (centered on 40%-50%) is due to the formation of the network structure where the unit of 1DMSO:1H2O and 2DMSO:1H2O dominates to give rise to rich dynamical features. Through an analysis of partial solvation dynamics an interesting negative cross-correlation between water and DMSO is observed that makes an important contribution to relaxation at intermediate to longer times.
Exclusivity structures and graph representatives of local complementation orbits
Authors: Cabello Adán , Parker Matthew G. , Scarpa Giannicola , Severini Simone
Published: July 2013

We describe a construction that maps any connected graph G on three or more vertices into a larger graph, H(G), whose independence number is strictly smaller than its Lovász number which is equal to its fractional packing number. The vertices of H(G) represent all possible events consistent with the stabilizer group of the graph state associated with G, and exclusive events are adjacent. Mathematically, the graph H(G) corresponds to the orbit of G under local complementation. Physically, the construction translates into graph-theoretic terms the connection between a graph state and a Bell inequality maximally violated by quantum mechanics. In the context of zero-error information theory, the construction suggests a protocol achieving the maximum rate of entanglement-assisted capacity, a quantum mechanical analogue of the Shannon capacity, for each H(G). The violation of the Bell inequality is expressed by the one-shot version of this capacity being strictly larger than the independence number. Finally, given the correspondence between graphs and exclusivity structures, we are able to compute the independence number for certain infinite families of graphs with the use of quantum non-locality, therefore highlighting an application of quantum theory in the proof of a purely combinatorial statement.
Comparison of low-rank tensor expansions for the acceleration of quantum chemistry computations
Authors: Hoy Erik P. , Shenvi Neil , Mazziotti David A.
Published: July 2013

Low-rank spectral expansion and tensor hypercontraction are two promising techniques for reducing the size of the two-electron excitation tensor by factorizing it into products of smaller tensors. Both methods can potentially realize an O(r4) quantum chemistry method where r is the number of one-electron orbitals. We compare the two factorizations in this paper by applying them to the parametric 2-electron reduced density matrix method with the M functional [D. A. Mazziotti, Phys. Rev. Lett. 101, 253002 (2008)]10.1103/PhysRevLett.101.253002. We study several inorganic molecules, alkane chains, and potential curves as well as reaction and dissociation energies. The low-rank spectral expansion, we find, is typically more efficient than tensor hypercontraction due to a faster convergence of the energy and a smaller constant prefactor in the energy optimization. Both factorizations are applicable to the acceleration of a wide range of wavefunction and reduced-density-matrix methods.
Voltage-dependent photocurrent transients of PTB7:PC70BM solar cells: Experiment and numerical simulation
Authors: Li Zhe , Lakhwani Girish , Greenham Neil C. , McNeill Christopher R.
Published: July 2013

Transient photocurrent measurements on efficient polymer/fullerene solar cells based on a blend of the donor polymer PTB7 with the fullerene acceptor PC70BM are reported. In particular, we examine the light intensity dependence and voltage dependence of the turn-on and turn-off photocurrent dynamics of devices in response to a 200 μs square light pulse. At short circuit, subtle changes in the turn-on and turn-off dynamics are observed consistent with charge-density-dependent transport phenomena. As the working voltage is moved from short circuit to open circuit, we observe the appearance of an initial transient photocurrent peak a few microseconds after turn-on before the device settles to steady state. Furthermore, we observe only a weak dependence of the charge extraction dynamics on the working voltage, with the amount of charge extracted monotonically decreasing as the working voltage is moved from short circuit to open circuit. This collection of features is interpreted with the aid of numerical simulations in terms of charge trapping, with increased trap-assisted recombination closer to open circuit. The operation of devices fabricated with and without the solvent additive di-iodooctane is also compared. Charge trapping features are reduced for optimized devices fabricated with the solvent additive compared to devices fabricated without. The use of the solvent additive di-iodooctane in this system is therefore important in minimizing trap-assisted recombination.
Note: External multipass optical trap for counterpropagating pulsed laser applications
Authors: Graul J. S. , Ketsdever A. D. , Andersen G. P. , Lilly T. C.
Published: July 2013

Pulses from a 12 mJ, frequency doubled, 5 ns FWHM, pulsed Nd:YAG laser were split and injected into opposing sides of a symmetric 2.44 m (96 in.) optical ring trap. Using a Pockels cell, the counterpropagating pulses were “locked” into the trap for ≥50 round trips. This optical trap has potential applications ranging from established cavity processes, e.g., laser-based absorption spectroscopy and x-ray production, to new processes such as non-resonant optical lattice gas heating and time-resolved coherent Rayleigh-Brillouin scattering diagnostic studies.
Massively parallel aligned microfibers-based harvester deposited via in situ, oriented poled near-field electrospinning
Authors: Fuh Yiin-Kuen , Chen Shao-Yu , Ye Jia-Cheng
Published: July 2013

In this study, we demonstrate a direct-write, in situ poled polyvinylidene fluoride power generator via near-field electrospinning and fully encapsulated on a flexible substrate. An unique polarity alignment and a total of 500 microfibers continuously deposited in parallel and serial configurations are capable of producing a peak output voltage of ∼1.7 V and the current of ∼300 nA, which is two to three orders of magnitude increase in both voltage/current outputs when compared with near-field electrospinning setup of a single nanofiber and the similar amount of microfibers with postpoling treatment.
Isotropic Mie resonance-based metamaterial perfect absorber
Authors: Liu Xiaoming , Zhao Qian , Lan Chuwen , Zhou Ji
Published: July 2013

An isotropic Mie resonance-based metamaterial perfect absorber with near unity absorbance is experimentally and numerically demonstrated. The metamaterial is constructed with an array of dielectric cubes and a metallic ground plane. The absorption peak of the metamaterial perfect absorber is dependent on the permittivity and the side length of the dielectric cubes. A good agreement between experimental and simulated result at X band absorption is achieved.
Far field observation and theoretical analyses of light directional imaging in metamaterial with stacked metal-dielectric films
Authors: Wang Changtao , Gao Ping , Tao Xing , Zhao Zeyu , Pu Mingbo , Chen Po , Luo Xiangang
Published: July 2013

We report experimental observation of directional imaging of evanescent waves in layered metal-dielectric metamaterial. The investigation is performed with Ag/SiO2 multilayers combined with nano-object featured by a silicon mask slit. Evanescent waves of directional imaging are transferred to far field by roughening the top Ag layer and observed with a microscope objective. Experimental results agree well with numerical simulations. In addition, directional imaging behavior dependences on geometrical parameters are further presented and show great deviations with effective medium theory in some cases.
Selective area growth of InP in shallow trench isolation on large scale Si(001) wafer using defect confinement technique
Authors: Merckling C. , Waldron N. , Jiang S. , Guo W. , Richard O. , Douhard B. , Moussa A. , Vanhaeren D. , Bender H. , Collaert N. , Heyns M. , Thean A. , Caymax M. , Vandervorst W.
Published: July 2013

Heterogeneous integration of III–V semiconductors on Si substrate has been attracting much attention as building blocks for next-generation electronics, optoelectronics, and photonics. In the present paper, we studied the selective area epitaxial studies of InP grown on 300 mm on-axis Si (001) substrates patterned with Shallow Trench Isolation (STI) using the necking effect technique to trap crystalline defects on the sidewalls. We make use of a thin Ge buffer in the bottom of the trench to reduce interfacial strain at the interface and to promote InP nucleation. We could show here, by systematic analysis, the strong impact of the growth temperatures and pressures of the InP layer on the growth uniformity along the trench and crystalline quality that we correlated with resistance changes and interdiffusion measured in the III–V layer. The key challenge remains in the ultimate control of crystalline quality during InP selective growth in order to reduce defect density to enable device-quality III–V virtual substrates on large-scale Si substrates.
Disorder-induced linear magnetoresistance in (221) topological insulator Bi2Se3 films
Authors: He H. T. , Liu H. C. , Li B. K. , Guo X. , Xu Z. J. , Xie M. H. , Wang J. N.
Published: July 2013

A linear magnetoresistance (LMR) with strong temperature dependence and peculiar non-symmetry with respect to the applied magnetic field is observed in high-index (221) Bi2Se3 films. Different from the LMR observed in the previous studies which emphasize the role of gapless linear energy dispersion, this LMR is of disorder origin and possibly arises from the electron surface accumulation layer of the film. Besides, an abnormal negative magneto-resistance that shows a non-monotonic temperature dependence and persists even at high temperatures and in strong magnetic fields is also observed.
Splitting a droplet with oil encapsulation using surface acoustic wave excited by electric signal with low power
Authors: Zhang Anliang , Zha Yan , Fu Xingting
Published: July 2013

A new method for splitting a droplet with oil encapsulation is presented. An interdigital transducer and a reflector are fabricated on a 128° yx-LiNbO3 piezoelectric substrate using microelectric technology. An electric signal with the power of 12.3 dBm is applied to the interdigital transducer to generate surface acoustic wave, which is radiated into a droplet with oil encapsulation, leading to surface acoustic wave streaming force. When the electric signal is suddenly moved off, the breakup of the droplet occurs due to inertial force. Color dye solution droplets encapsulated by oil droplets are demonstrated. The effects of electric power, the volume ratio of color dye solution to oil, and the volume of mother droplet on the breakup of droplets are studied. As applications, the presented method is successfully applied to mixture operation and color development reaction of two droplets. The method provides a new sample preparation technique, which is helpful for microfluidic biochemical analysis in a piezoelectric microfluidic system.
Variation in leaf structure of the invasive Madeira vine (Anredera cordifolia, Basellaceae) at different light levels
Authors: Boyne Richard L. , Osunkoya Olusegun O. , Scharaschkin Tanya
Published: July 2013

Madeira vine (Anredera cordifolia (Ten.) Steenis) is a climber in the angiosperm family Basellaceae. It is native to South America and has naturalised in Australia. It is regarded as a serious environmental weed because of the structural damage it causes to native vegetation. The present study, for the first time, documents anatomical and morphological traits of the leaves of A. cordifolia and considers their implications for its ecology and physiology. Plants were grown under three different light levels, and anatomical and morphological leaf characters were compared among light levels, among cohorts, and with documented traits of the related species, Basella alba L. Stomata were present on both the adaxial and abaxial sides of the leaf, with significantly more stomata on the abaxial side and under high light. This may account for the ability of this species to fix large amounts of carbon and rapidly respond to light gaps. The leaves had very narrow veins and no sclerenchyma, suggesting a low construction cost that is associated with invasive plants. There was no significant difference in any of the traits among different cohorts, which agrees with the claim that A. cordifolia primarily propagates vegetatively. The anatomy and morphology of A. cordifolia was similar to that of B. alba.
Do woodland birds prefer to forage in healthy Eucalyptus wandoo trees?
Authors: Moore T. L. , Valentine L. E. , Craig M. D. , Hardy G. E. StJ. , Fleming P. A.
Published: July 2013

Globally, many forests and woodlands are in decline. The marked loss of canopy foliage typical of these declines results in reduced foraging resources (e.g. nectar, pollen, and insects) and, subsequently, can reduce habitat quality for woodland birds. In south-west Western Australia, patches of Eucalyptus wandoo woodlands have shown a decline in condition since at least 2002. We investigated how changes in E. wandoo condition affect the woodland bird community. Foraging activities of three bird species were recorded for 20 sites in Dryandra State Forest and Wandoo Conservation Park either by conducting watches on focal trees (‘sitting’ method), or following individuals through the woodland (‘following’ method). Condition assessments of trees used by the birds were compared with those for trees available at the study site. Weebills (Smicrornis brevirostris; canopy insectivore) displayed preference for healthy trees (low amounts of canopy dieback), whereas rufous treecreepers (Climacteris rufa; bark-foraging insectivore) preferred trees with a higher proportion of dead branches. Yellow-plumed honeyeaters (Lichenostomus ornatus; insectivore/nectarivore) foraged in older, larger E. wandoo trees having full canopies with few signs of tree decline. Tree declines, such as that happening in E. wandoo, alter the foraging resources and habitat available to woodland birds.
Predictors and Molecular Epidemiology of Community-Onset Extended-Spectrum β-Lactamase–Producing Escherichia coli Infection in a Midwestern Community
Authors: Banerjee Ritu , Strahilevitz Jacob , Johnson James R. , Nagwekar Payai P. , Schora Donna M. , Shevrin Ilene , Du Hongyan , Peterson Lance R. , Robicsek Ari
Published: July 2013

Objective.

To identify predictors of community-onset extended-spectrum β-lactamase (ESBL)-producing Escherichia coli infection.

Design.

Prospective case-control study.

Setting.

Acute care hospitals and ambulatory clinics in the Chicago, Illinois, region.

Patients.

Adults with E. coli clinical isolates cultured in ambulatory settings or within 48 hours of hospital admission.

Methods.

Cases were patients with ESBL-producing E. coli clinical isolates cultured in ambulatory settings or within 48 hours of admission, and controls were patients with non-ESBL-producing E. coli isolates, matched to cases by specimen, location, and date. Clinical variables were ascertained through interviews and medical record review. Molecular methods were used to identify ESBL types, sequence type ST131, and aac(6′)-Ib-cr.

Results.

We enrolled 94 cases and 158 controls. Multivariate risk factors for ESBL-producing E. coli infection included travel to India in the past year (odds ratio [OR], 14.40 [95% confidence interval (CI), 2.92-70.95]), ciprofloxacin use (OR, 3.92 [95% CI, 1.90-8.1]), and age (OR, 1.04 [95% CI, 1.02-1.06]). Case isolates exhibited high prevalence of CTX-M-15 (78%), ST131 (50%), and aac(6′)-Ib-cr (66% of isolates with CTX-M-15).

Conclusions.

Providers should be aware of the increased risk of ESBL-producing E. coli infection among returned travelers, especially those from India.
Colliding with G2 near the Galactic Centre: a geometrical approach
Authors: de la Fuente Marcos R. , de la Fuente Marcos C.
Published: July 2013

The object G2 will pass within ∼100 au from Sgr A* in 2014. Due to its very short periapse, the study of the dynamical evolution of this object in the short-term future may offer some insight into the region surrounding the supermassive black hole at the centre of the Galaxy. With this scenario in mind, it has recently been proposed by Bartos et al. that, prior to its perinigricon, G2 will likely experience multiple encounters with members of the black hole and neutron-star populations believed to orbit near the Galactic Centre. Here, we further explore this possibility and study the general case for collisions with the G2 object using the latest orbital solutions provided by Phifer et al. and Gillessen et al., and a Monte Carlo approach to estimate the minimum orbit intersection distance (MOID) with G2 as a function of the orbital parameters of the incoming body. Our results indicate that encounters at distances closer than 100 au started to become statistically significant only during the last few years or so. MOIDs under 100 au are statistically more probable for the most dynamically cold orbits. If there is a population of objects moving in low-inclination, low-eccentricity orbits around the central black hole, the highest probability for a close encounter with G2 is found to be in the period 2014 January–March, but enhanced activity due to encounters may start as early as 2013 July–August.
Human mobility patterns predict divergent epidemic dynamics among cities
Authors: Dalziel Benjamin D. , Pourbohloul Babak , Ellner Stephen P.
Published: July 2013

The epidemic dynamics of infectious diseases vary among cities, but it is unclear how this is caused by patterns of infectious contact among individuals. Here, we ask whether systematic differences in human mobility patterns are sufficient to cause inter-city variation in epidemic dynamics for infectious diseases spread by casual contact between hosts. We analyse census data on the mobility patterns of every full-time worker in 48 Canadian cities, finding a power-law relationship between population size and the level of organization in mobility patterns, where in larger cities, a greater fraction of workers travel to work in a few focal locations. Similarly sized cities also vary in the level of organization in their mobility patterns, equivalent on average to the variation expected from a 2.64-fold change in population size. Systematic variation in mobility patterns is sufficient to cause significant differences among cities in infectious disease dynamics—even among cities of the same size—according to an individual-based model of airborne pathogen transmission parametrized with the mobility data. This suggests that differences among cities in host contact patterns are sufficient to drive differences in infectious disease dynamics and provides a framework for testing the effects of host mobility patterns in city-level disease data.
Morphology and small-subunit rRNA gene sequences of two novel marine ciliates, Metanophrys orientalis spec. nov. and Uronemella sinensis spec. nov. (Protista, Ciliophora, Scuticociliatia), with an improved diagnosis of the genus Uronemella
Authors: Pan Xuming , Zhu Mingzhuang , Ma Honggang , Al-Rasheid Khaled A. S. , Hu Xiaozhong
Published: July 2013

The morphology and infraciliature of two novel marine scuticociliates,Metanophrys orientalisspec. nov. andUronemella sinensisspec. nov., collected from sandy beaches at Qingdao, China, were investigated using live observation and protargol-staining methods.Metanophrys orientalisspec. nov. is distinguished by the following characteristics: marine habitat and a slender to elongate oval body with pointed anterior end and rounded caudal end,in vivoabout 25–50 µm long; buccal field about a quarter to a third of body length; nine or ten somatic kineties with dikinetids approximately in anterior half of body, monokinetids in posterior half; membranelles 1 and 2 almost equal in length and composed of two and three longitudinal rows of kinetids respectively; paroral membrane with zigzag structure extending anteriorly to middle portion of membranelle 2; contractile vacuole pore located at posterior end of somatic kinety 1. The genusUronemellais redefined as follows: marine form with an elongate-elliptical or inverted pear-shaped body; apical plate conspicuous; buccal field about two-thirds of body length, cytostome subequatorially located; oral apparatusUronema-like; somatic kineties comprising a mixture of dikinetids and monokinetids.Uronemella sinensisspec. nov. is recognized by having an elongate-elliptical body with truncated apical frontal plate, sizein vivoabout 25–35×15–20 µm, nine or ten somatic kineties, membranelle 1 consisting of two or three basal bodies, contractile vacuole pore at posterior end of somatic kinety 1. This study also compared the small-subunit rRNA gene sequences of these two species with other closely related species to show the sequence divergence, which ranged from 3.53 to 9.60 %. Phylogenetic analyses support the contention that the genusUronemellais monophyletic, whileMetanophrysis non-monophyletic.
Sphingobacterium changzhouense sp. nov., a bacterium isolated from a rice field
Authors: Liu Hongming , Zhang Jun , Chen Dingbin , Cao Li , Lu Peng , Wu ZhiGuo , Yang Fan , Li Shunpeng , Hong Qing
Published: July 2013

A Gram-stain-negative, yellow, non-spore-forming, rod-shaped bacterium, designated N7T, was isolated from a soil sample collected from a rice field in Jiangsu, China, and was characterized using a polyphasic taxonomic approach. Strain N7Tgrew optimally at 25–30 °C, pH 6.0–8.0, and in the presence of 1 % NaCl (w/v). 16S rRNA gene sequence analysis indicated that strain N7Twas a member of the genusSphingobacteriumand was closely related toSphingobacterium multivorumIAM14316T(97.49 %) andSphingobacterium canadenseCR11T(97.11 %), sharing less than 97 % sequence similarities with other species of the genusSphingobacterium. The predominant respiratory quinone of strain N7Twas MK-7 and major fatty acids were summed features 3 (C16 : 1ω6cand/or C16 : 1ω7c), iso-C15 : 0, C16 : 0and iso-C17 : 03-OH. The G+C content of the DNA was 40.9±0.5 mol%. The levels of DNA–DNA relatedness between strain N7Tand the most closely related speciesS. multivorumIAM 14316TandS. canadenseCR11Twere 21 % and 15 %, respectively. Based on these results, strain N7Tis proposed to represent a separate species within the genusSphingobacterium. The nameSphingobacterium changzhouensesp. nov. is suggested and the type strain is N7T( = CCTCC AB 2012100T = KACC 16854T).
Validation of three-dimensional diffraction contrast tomography reconstructions by means of electron backscatter diffraction characterization
Authors: Syha Melanie , Trenkle Andreas , Lödermann Barbara , Graff Andreas , Ludwig Wolfgang , Weygand Daniel , Gumbsch Peter
Published: July 2013

Microstructure reconstructions resulting from diffraction contrast tomography data of polycrystalline bulk strontium titanate were reinvestigated by means of electron backscatter diffraction (EBSD) characterization. Corresponding two-dimensional grain maps from the two characterization methods were aligned and compared, focusing on the spatial resolution at the internal interfaces. The compared grain boundary networks show a remarkably good agreement both morphologically and in crystallographic orientation. Deviations are critically assessed and discussed in the context of diffraction data reconstruction and EBSD data collection techniques.
Pre‐eclampsia is associated with, and preceded by, hypertriglyceridaemia: a meta‐analysis
Authors: Gallos ID , Sivakumar K , Kilby MD , Coomarasamy A , Thangaratinam S , Vatish M
Published: July 2013

Background

Elevated triglycerides are a feature of the metabolic syndrome, maternal obesity, maternal vasculitis (i.e. systemic lupus erythematosus) and diabetes mellitus. These conditions are all known risk factors for pre‐eclampsia. Hypertriglyceridaemia therefore may be associated with pre‐eclampsia and indeed this may precede the presence of overt disease.

Objective

In this study we determine the association between hypertriglyceridaemia and pre‐eclampsia in pregnant women.

Search strategy

We searched MEDLINE, EMBASE, Web of Science, Excerpta Medica Database, ISI Web of Knowledge, Cumulative Index to Nursing and Allied Health Literature, Cochrane Library from inception until June 2012 and reference lists of relevant studies.

Selection criteria

Two reviewers independently selected studies on pregnant women where triglycerides were measured and women were followed up until the development of pre‐eclampsia or selected on the basis of presence of pre‐eclampsia and compared with controls.

Data collection and analysis

We collected and meta‐analysed the weighted mean differences (WMDs) of triglyceride levels from individual studies using a random effects model.

Main results

We found strong evidence from meta‐analysis of 24 case–control studies (2720 women) that pre‐eclampsia is associated with higher levels of serum triglycerides (WMD 0.78 mmol/l, 95% confidence interval 0.6–0.96, P < 0.00001). This finding is also confirmed in five cohort studies, that recruited 3147 women in the second trimester before the onset of pre‐eclampsia, which proves that hypertriglyceridaemia precedes the onset of pre‐eclampsia (WMD 0.24 mmol/l, 95% confidence interval 0.13–0.34, P < 0.0001).

Author's conclusions

Hypertriglyceridaemia is associated with and precedes the onset of pre‐eclampsia. Further research should focus on defining the prognostic accuracy of this test to identify women at risk and the beneficial effect of triglyceride‐lowering therapies in pregnancy.
A New Triassic Primitive Ichthyosaur from Yuanan, South China
Authors: Xiaohong CHEN , SANDER P. Martin , Long CHENG , Xiaofeng WANG
Published: July 2013

Based on the systematic study of two fossil skeleton specimens collected from the top of the third member of the marine Lower Triassic Jialingjiang Formation of Yuanan, Hubei Province, South China, a new Early Triassic primitive ichthyosaur Chaohusaurus zhangjiawanensis sp. nov. is reported and described. The beds yielding the type material are correlated with the Neospathodus homeri–N. triangularis Conodont zone. The new taxon is most similar to Chaohusaurus geishanensis Young and Dong, 1972 in the shape and configuration of the scapula, forefin, pelvic girdle and hindfin, presacral vertebral count and well‐developed caudal peak, but distinguished from the latter by its larger size, the position of the pineal foramen in the centre of the parietal, the occurrence of a larger calcaneum in hindfin and the first sacral rib with distal expansion. The new species exhibits common features of primitive ichthyosaurs such as: (1) the prefrontal has an antero‐dorsal shelf projecting towards the orbit; (2) the upper temporal fenestra is small; (3) the postorbital and the squamosal meet laterally to the upper temporal fenestra; and (4) cylindrical centra. However, more derived ichthyosaur characters are seen with the frontal separated from the orbital dorsal margin by the contact of the prefrontal and postfrontal, which offer new clues to the early radiation of ichthyosaurs.
Petrogenesis of the Üçkapılı Granitoid and its Mafic Enclaves in Elmalı Area (Niğde, Central Anatolia, Turkey)
Authors: KURT Hüseyin , KOÇAK Kerim , ASAN Kürşad , KARAKAŞ Mustafa
Published: July 2013

The Late Cretaceous Üçkapılı Granitoid including mafic microgranular enclaves intruded into metapelitic and metabasic rocks, and overlain unconformably by Neogene ignimbrites in the Niǧde area of Turkey. It is mostly granite and minor granodiorite in composition, whereas its enclaves are dominantly gabbro with a few diorites in composition. The Üçkapılı Granitoid is composed mainly of quartz, K‐feldspar, plagioclase, biotite, muscovite and minor amphibole while its enclaves contain mostly plagioclase, amphibole, minor pyroxene and biotite. The Üçkapılı Granitoid has calcalkaline and peraluminous (A/CNK= 1.0–1.3) geochemical characteristics. It is characterized by high LILE/HFSE and LREE/HREE ratios ((La/Lu)N= 3–33), and has negative Ba, Ta, Nb and Eu anomalies, resembling those of collision granitoids. The Üçkapılı Granitoid has relatively high 87Sr86Sr(i) ratios (0.711189–0.716061) and low εNd(t) values (−5.13 to −7.13), confirming crustal melting. In contrast, the enclaves are tholeiitic and metaluminous, and slightly enriched in LILEs (K, Rb) and Th, and have negative Ta, Nb and Ti anomalies; propose that they were derived from a subduction‐modified mantle source. Based on mineral and whole rock chemistry data, the Üçkapılı granitoid is H‐(hybrid) type, post‐collision granitoid developed by mixing/mingling processes between crustal melts and mantle‐derived mafic magmas.
Semiconducting Mineral Photocatalytic Regeneration of Fe2+ Promotes Carbon Dioxide Acquisition by Acidithiobacillus ferrooxidans
Authors: Yan LI , Anhuai LU , Xin WANG , Hongrui DING , Changqiu WANG
Published: July 2013

Chemoautotrophic organisms have once been excluded from the development of universally applicable CO2 fixation technology due to its low production yields of biomass. In this study, we used Acidithiobacillus ferrooxidans (A.f.) as a model chemoautotrophic microorganism to test the hypothesis that exogenetic photoelectrons from semiconducting mineral photocatalysis can enable the regeneration of Fe2+ that could be then used by A.f. and support its growth. In a simulated electrochemical system, where exogenetic electrons were provided by an electrochemical approach, an accelerated growth rate of A.f. was observed as compared with that in traditional batch cultivation. In a coupled system, where light‐irradiated natural rutile provided the primary electron source to feed A.f., the bacterial growth rate as well as the subsequent CO2 fixation rate was demonstrated to be in a light‐dependent manner. The sustaining flow of photogenerated electrons from semiconducting mineral to bacteria provided an inexhaustible electron source for chemoautotrophic bacteria growth and CO2 fixation. This finding might contribute to the development of novel effective CO2 fixation technology.