bluuebunny/crossref_metadata_2025 huggingface dataset:
Protection layers on a superconducting microwave resonator toward a hybrid quantum system
Authors: Lee Jongmin , Park Dong Hun
Published: October 2015

We propose a protection scheme of a superconducting microwave resonator to realize a hybrid quantum system, where cold neutral atoms are coupled with a single microwave photon through magnetic dipole interaction at an interface inductor. The evanescent field atom trap, such as a waveguide/nanofiber atom trap, brings both surface-scattered photons and absorption-induced broadband blackbody radiation which result in quasiparticles and a low quality factor at the resonator. A proposed multiband protection layer consists of pairs of two dielectric layers and a thin nanogrid conductive dielectric layer above the interface inductor. We show numerical simulations of quality factors and reflection/absorption spectra, indicating that the proposed multilayer structure can protect a lumped-element microwave resonator from optical photons and blackbody radiation while maintaining a reasonably high quality factor.
Influence of lithium coating on the optics of Doppler backscatter system
Authors: Zhang X. H. , Liu A. D. , Zhou C. , Hu J. Q. , Wang M. Y. , Yu C. X. , Liu W. D. , Li H. , Lan T. , Xie J. L.
Published: October 2015

This paper presents the first investigation of the effect of lithium coating on the optics of Doppler backscattering. A liquid lithium limiter has been applied in the Experimental Advanced Superconducting Tokamak (EAST), and a Doppler backscattering has been installed in the EAST. A parabolic mirror and a flat mirror located in the vacuum vessel are polluted by lithium. An identical optical system of the Doppler backscattering is set up in laboratory. The power distributions of the emission beam after the two mirrors with and without lithium coating (cleaned before and after), are measured at three different distances under four incident frequencies. The results demonstrate that the influence of the lithium coating on the power distributions are very slight, and the Doppler backscattering can work normally under the dosage of lithium during the 2014 EAST campaign.
High bandwidth deflection readout for atomic force microscopes
Authors: Steininger Juergen , Bibl Matthias , Yoo Han Woong , Schitter Georg
Published: October 2015

This contribution presents the systematic design of a high bandwidth deflection readout mechanism for atomic force microscopes. The widely used optical beam deflection method is revised by adding a focusing lens between the cantilever and the quadrant photodetector (QPD). This allows the utilization of QPDs with a small active area resulting in an increased detection bandwidth due to the reduced junction capacitance. Furthermore the additional lens can compensate a cross talk between a compensating z-movement of the cantilever and the deflection readout. Scaling effects are analyzed to get the optimal spot size for the given geometry of the QPD. The laser power is tuned to maximize the signal to noise ratio without limiting the bandwidth by local saturation effects. The systematic approach results in a measured −3 dB detection bandwidth of 64.5 MHz at a deflection noise density of 62fm/Hz.
Flow distribution in parallel microfluidic networks and its effect on concentration gradient
Authors: Guermonprez Cyprien , Michelin Sébastien , Baroud Charles N.
Published: October 2015

The architecture of microfluidic networks can significantly impact the flow distribution within its different branches and thereby influence tracer transport within the network. In this paper, we study the flow rate distribution within a network of parallel microfluidic channels with a single input and single output, using a combination of theoretical modeling and microfluidic experiments. Within the ladder network, the flow rate distribution follows a U-shaped profile, with the highest flow rate occurring in the initial and final branches. The contrast with the central branches is controlled by a single dimensionless parameter, namely, the ratio of hydrodynamic resistance between the distribution channel and the side branches. This contrast in flow rates decreases when the resistance of the side branches increases relative to the resistance of the distribution channel. When the inlet flow is composed of two parallel streams, one of which transporting a diffusing species, a concentration variation is produced within the side branches of the network. The shape of this concentration gradient is fully determined by two dimensionless parameters: the ratio of resistances, which determines the flow rate distribution, and the Péclet number, which characterizes the relative speed of diffusion and advection. Depending on the values of these two control parameters, different distribution profiles can be obtained ranging from a flat profile to a step distribution of solute, with well-distributed gradients between these two limits. Our experimental results are in agreement with our numerical model predictions, based on a simplified 2D advection-diffusion problem. Finally, two possible applications of this work are presented: the first one combines the present design with self-digitization principle to encapsulate the controlled concentration in nanoliter chambers, while the second one extends the present design to create a continuous concentration gradient within an open flow chamber.
Lifetime of hydrogenated composite cathodes in a vacuum arc ion source
Authors: Savkin K. P. , Frolova V. P. , Nikolaev A. G. , Oks E. M. , Yushkov G. Yu. , Barengolts S. A.
Published: October 2015

The paper reports on a study of the mass-charge state of the plasma produced in a vacuum arc discharge with composite cathodes which were copper-disk coated with a hydrogenated Zr film of thicknesses 9, 22, and 35 μm. The cathodes allow the generation of multicomponent gas and metal ion beams with a hydrogen ion content from several to several tens of percent. Also investigated is the dependence of the H ion fraction in a beam on the Zr film thickness during erosion to the point of disappearance of Zr peaks in mass-charge spectra. The ability of the vacuum arc system to produce H ions is analyzed by analyzing the cathode lifetime as a function of the film thickness and pulse repetition frequency.
Highly directive and Gaussian far-field emission from “giant” photonic trumpets
Authors: Stepanov Petr , Delga Adrien , Gregersen Niels , Peinke Emanuel , Munsch Mathieu , Teissier Jean , Mørk Jesper , Richard Maxime , Bleuse Joël , Gérard Jean-Michel , Claudon Julien
Published: October 2015

Photonic trumpets are broadband dielectric antennas that efficiently funnel the emission of a point-like quantum emitter—such as a semiconductor quantum dot—into a Gaussian free-space beam. After describing guidelines for the taper design, we present a “giant” photonic trumpet. The device features a bottom diameter of 210 nm and a 5 μm wide top facet. Using Fourier microscopy, we show that 95% of the emitted beam is intercepted by a modest numerical aperture of 0.35. Furthermore, far-field measurements reveal a highly Gaussian angular profile, in agreement with the predicted overlap to a Gaussian beam Mg=0.98. Future application prospects include the direct coupling of these devices to a cleaved single-mode optical fiber. The calculated transmission from the taper base to the fiber already reaches 0.59, and we discuss strategies to further improve this figure of merit.
Coalescence-induced jumping of nanoscale droplets on super-hydrophobic surfaces
Authors: Liang Zhi , Keblinski Pawel
Published: October 2015

The coalescence-induced jumping of tens of microns size droplets on super-hydrophobic surfaces has been observed in both experiments and simulations. However, whether the coalescence-induced jumping would occur for smaller, particularly nanoscale droplets, is an open question. Using molecular dynamics simulations, we demonstrate that in spite of the large internal viscous dissipation, coalescence of two nanoscale droplets on a super-hydrophobic surface can result in a jumping of the coalesced droplet from the surface with a speed of a few m/s. Similar to the coalescence-induced jumping of microscale droplets, we observe that the bridge between the coalescing nano-droplets expands and impacts the solid surface, which leads to an acceleration of the coalesced droplet by the pressure force from the solid surface. We observe that the jumping velocity decreases with the droplet size and its ratio to the inertial-capillary velocity is a constant of about 0.126, which is close to the minimum value of 0.111 predicted by continuum-level modeling of Enright et al. [ACS Nano 8, 10352 (2014)].
Universal crossover of the charge carrier fluctuation mechanism in different polymer/carbon nanotubes composites
Authors: Barone C. , Landi G. , Mauro C. , Neitzert H. C. , Pagano S.
Published: October 2015

Carbon nanotubes added to polymer and epoxy matrices are compounds of interest for applications in electronics and aerospace. The realization of high-performance devices based on these materials can profit from the investigation of their electric noise properties, as this gives a more detailed insight of the basic charge carriers transport mechanisms at work. The dc and electrical noise characteristics of different polymer/carbon nanotubes composites have been analyzed from 10 to 300 K. The results suggest that all these systems can be regarded as random resistive networks of tunnel junctions formed by adjacent carbon nanotubes. However, in the high-temperature regime, contributions deriving from other possible mechanisms cannot be separated using dc information alone. A transition from a fluctuation-induced tunneling process to a thermally activated regime is instead revealed by electric noise spectroscopy. In particular, a crossover is found from a two-level tunneling mechanism, operating at low temperatures, to resistance fluctuations of a percolative network, in the high-temperature region. The observed behavior of 1/f noise seems to be a general feature for highly conductive samples, independent on the type of polymer matrix and on the nanotube density.
Biogeochemistry of dimethylsulfoniopropionate, dimethylsulfide and acrylic acid in the Yellow Sea and the Bohai Sea during autumn
Authors: Liu Yue , Liu Chun-Ying , Yang Gui-Peng , Zhang Hong-Hai , Zhang Sheng-hui
Published: October 2015

Environmental context Dimethylsulfide (DMS) is a climatically important biogenic trace gas that is emitted from oceans. This research focuses on the spatiotemporal distributions of DMS and its related compounds, i.e. dimethylsulfoniopropionate (DMSP) and acrylic acid (AA), and the influencing factors in the Yellow Sea and the Bohai Sea during autumn. In addition, the sea-to-air flux of DMS, kinetic responses of DMSP consumption as well as DMS and AA production are also investigated. This study is helpful in understanding the marine sulfur cycle in marginal seas in China. Abstract The biogeochemistry of dimethylsulfoniopropionate (DMSP), dimethylsulfide (DMS) and acrylic acid (AA) in the Yellow Sea (YS) and the Bohai Sea (BS) was investigated in November 2013. The concentrations (and ranges) of total DMSP (DMSPt), dissolved DMSP (DMSPd), DMS and AA in surface waters were 30.71 (1.07–122.50), 6.60 (0.85–35.67), 1.48 (0.53–5.32) and 42.2 (13.8–352.8) nmol L–1 respectively. The concentrations of DMSPd and AA were positively correlated with chlorophyll-a levels, which suggests that phytoplankton biomass has an important function in controlling DMSPd and AA distributions. Furthermore, DMS and AA concentrations revealed significant positive relationships with DMSPd concentrations. The average ratios of AA/(DMSP+AA) and DMS/AA were 53.98 and 7.62% respectively. The vertical profiles of DMSP, DMS and AA were characterised by high concentrations that mostly occur near the surface. Even under highly variable hydrographic conditions, a positive relationship was observed between DMSPt and chlorophyll-a concentrations. The rates of DMSPd consumption, as well as DMS and AA production, significantly varied with marine environments. The sea-to-air fluxes of DMS from the YS and the BS to the atmosphere were estimated to be in the range of 3.01 to 6.91μmol m–2day–1.
Monitoring predation behaviour of the pygmy bluetongue lizard to decide when conservation intervention is needed
Authors: Ebrahimi Mehregan , Godfrey Stephanie S. , Fenner Aaron L. , Bull C. Michael
Published: October 2015

Documenting natural behaviours may be an important component of conservation management of threatened species in that deviations from some behaviours may serve as early warning signs of subsequent deteriorating condition and the possible need for intervention. We described predation behaviour of the endangered Australian scincid lizard Tiliqua adelaidensis from 23 burrows by watching video images from cameras over 10 days each month for five months in spring and summer. We observed 341 predation attempts, of which 277 were successful. These lizards predominantly ambush passing prey from their burrow entrance without completely emerging from the burrow. Orthopterans were the major component of their captures; prey captures peaked in November and December. We measured the proportion of unsuccessful foraging attempts, the proportion of foraging attempts that involved full emergence, the mean distance a lizard moved away from the burrow entrance, and the proportion of plant parts in the diet. We suggest that if any of these parameters increase it could indicate the requirement for intervention management. Our study supports the view that behavioural monitoring could be considered as an integral component of any conservation management of endangered animal species.
Region-wide synchrony and traveling waves of dengue across eight countries in Southeast Asia
Authors: van Panhuis Willem G. , Choisy Marc , Xiong Xin , Chok Nian Shong , Akarasewi Pasakorn , Iamsirithaworn Sopon , Lam Sai K. , Chong Chee K. , Lam Fook C. , Phommasak Bounlay , Vongphrachanh Phengta , Bouaphanh Khamphaphongphane , Rekol Huy , Hien Nguyen Tran , Thai Pham Quang , Duong Tran Nhu , Chuang Jen-Hsiang , Liu Yu-Lun , Ng Lee-Ching , Shi Yuan , Tayag Enrique A. , Roque Vito G. , Lee Suy Lyndon L. , Jarman Richard G. , Gibbons Robert V. , Velasco John Mark S. , Yoon In-Kyu , Burke Donald S. , Cummings Derek A. T.
Published: October 2015

Significance

Persons living in the tropics and subtropics are at risk for dengue fever and dengue hemorrhagic fever, and large epidemics occur unexpectedly that can overburden healthcare systems. The spatial and temporal dynamics of dengue transmission are poorly understood, limiting disease control efforts. We compiled a large-scale dataset and analyzed continental-scale patterns of dengue in Southeast Asia. Our analysis shows that periods of elevated temperatures can drive the occurrence of synchronous dengue epidemics across the region. This multicountry collaborative study improved insight that may lead to improved prediction of dengue transmission patterns and more effective disease surveillance and control efforts.
A holistic picture of Austronesian migrations revealed by phylogeography of Pacific paper mulberry
Authors: Chang Chi-Shan , Liu Hsiao-Lei , Moncada Ximena , Seelenfreund Andrea , Seelenfreund Daniela , Chung Kuo-Fang
Published: October 2015

Significance

Paper mulberry, a common East Asian tree used for paper making, is propagated across the Pacific for making barkcloth, a practical and symbolic component of Austronesian material culture. Using chloroplast DNA sequences, we demonstrate a tight genealogical link between its populations in South China and North Taiwan, and South Taiwan and Remote Oceania by way of Sulawesi and New Guinea, presenting the first study, to our knowledge, of a commensal plant species transported to Polynesia whose phylogeographic structure concurs with expectations of the “out of Taiwan” hypothesis of Austronesian expansion. As a commensal plant likely transported across the full range of Austronesian expansion from South China to East Polynesia, paper mulberry may also be the most widely transported fiber crop in human prehistory.
Optofluidic wavelength division multiplexing for single-virus detection
Authors: Ozcelik Damla , Parks Joshua W. , Wall Thomas A. , Stott Matthew A. , Cai Hong , Parks Joseph W. , Hawkins Aaron R. , Schmidt Holger
Published: October 2015

Significance

The ability to simultaneously detect and identify multiple biological particles or biomarkers is one of the key requirements for molecular diagnostic tests that are becoming even more important as personalized and precision medicine place increased emphasis on such capabilities. Integrated optofluidic platforms can help create such highly sensitive, multiplexed assays on a small, dedicated chip. We introduce a method for multiplex fluorescence detection of single bioparticles by creating color-dependent excitation spot patterns from a single integrated waveguide structure. Detection and identification of individual virus particles from three different influenza subtypes are demonstrated. The principle can be readily applied to amplification-free detection of nucleic acid biomarkers as well as larger target numbers using combinatorial color coding.
Peptidoglycan synthesis in
Mycobacterium tuberculosis
is organized into networks with varying drug susceptibility
Authors: Kieser Karen J. , Baranowski Catherine , Chao Michael C. , Long Jarukit E. , Sassetti Christopher M. , Waldor Matthew K. , Sacchettini James C. , Ioerger Thomas R. , Rubin Eric J.
Published: October 2015

Significance

The rise of drug-resistant
Mycobacterium tuberculosis
(
Mtb
) underscores the critical need for a better understanding of essential physiological processes. Among these is cell-wall synthesis, the target of many antibiotics. To understand how
Mtb
orchestrates synthesis of its cell wall, we performed whole-genome interaction studies in cells with different peptidoglycan synthesis mutations. We found that different enzymes become required for bacterial growth in
ΔponA1
,
ΔponA2
, or
ΔldtB
cells, suggesting that discrete cell envelope biogenesis networks exist in
Mtb
. Furthermore, we show that these networks’ enzymes are differentially susceptible to cell-wall–active drugs. Our data provide insight into the essential processes of cell-wall synthesis in
Mtb
and highlight the role of different synthesis networks in antibiotic tolerance.
Variable genetic architectures produce virtually identical molecules in bacterial symbionts of fungus-growing ants
Authors: Sit Clarissa S. , Ruzzini Antonio C. , Van Arnam Ethan B. , Ramadhar Timothy R. , Currie Cameron R. , Clardy Jon
Published: October 2015

Significance

Bacterially produced natural products comprise a group of molecules with highly diverse and generally complex structures that possess a remarkable array of biological activities. These molecules are separated into families sharing a common structural core and, accordingly, conserved sets of genes encoding the biosynthetic enzymes required to generate these shared structural features. Genomic characterization of related bacteria that produce remarkably similar molecules led to the surprising discovery that gene context was not conserved for the respective biosynthetic pathways. A comparison of these variable arrangements documents one way in which closely related symbiotic bacteria acquire the capacity to produce new molecules with new functions.
Mutation of the ER retention receptor KDELR1 leads to cell-intrinsic lymphopenia and a failure to control chronic viral infection
Authors: Siggs Owen M. , Popkin Daniel L. , Krebs Philippe , Li Xiaohong , Tang Miao , Zhan Xiaoming , Zeng Ming , Lin Pei , Xia Yu , Oldstone Michael B. A. , Cornall Richard J. , Beutler Bruce
Published: October 2015

Significance

Chaperones in the endoplasmic reticulum (ER) are essential for protein folding and for the maintenance of an efficient secretory pathway. These chaperones can also accompany their substrates during transit from the ER to the Golgi. The prototypical mammalian KDEL receptor (KDELR1) functions by returning chaperones and other proteins to the ER. We show that a recessive missense mutation of
Kdelr1
in mice is associated with low numbers of lymphocytes in the blood (lymphopenia), reduced expression of the T-cell receptor, and compromised antiviral immunity.
Photon gating in four-dimensional ultrafast electron microscopy
Authors: Hassan Mohammed T. , Liu Haihua , Baskin John Spencer , Zewail Ahmed H.
Published: October 2015

Significance

In this contribution, we demonstrate a unique concept in the use of photon-induced near-field electron microscopy—combining one electron pulse and two optical pulses—as a probe for ultrafast dynamics of matter in electron microscopy. Photon–electron coupling permits the use of a short optical pulse to gate the electron pulse, which is serving as a probe of the ultrafast dynamics triggered by another optical pulse. This technique provides the high spatial and temporal resolution of the electron pulse and optical laser pulses, respectively, both in ultrafast electron microscopy (UEM) measurements. This development paves the way for numerous studies in imaging of matter not only with few femtosecond resolution but also with the potential for attosecond imaging in UEM.
Mapping of histone modifications in episomal HBV cccDNA uncovers an unusual chromatin organization amenable to epigenetic manipulation
Authors: Tropberger Philipp , Mercier Alexandre , Robinson Margaret , Zhong Weidong , Ganem Don E. , Holdorf Meghan
Published: October 2015

Significance

Chronic hepatitis B virus (HBV) infection is maintained by the persistence of episomal HBV closed circular DNA (cccDNA) in infected hepatocytes. Current therapeutic regimes have no or limited impact on cccDNA, and the development of cccDNA-targeted therapies is complicated by our limited understanding of cccDNA regulation. We present a novel approach and first detailed analysis to our knowledge of cccDNA chromatin from de novo infected cells and infected liver tissue and reveal general features of cccDNA chromatin organization, and features that are unique to each source of cccDNA. We show that cccDNA chromatin is modulated by innate immunity and manipulated with an epigenetic agent, thereby establishing the importance of chromatin for cccDNA regulation and as a potential target for therapy of chronic HBV infection.
Growth factor signaling to mTORC1 by amino acid–laden macropinosomes
Authors: Yoshida Sei , Pacitto Regina , Yao Yao , Inoki Ken , Swanson Joel A.
Published: October 2015

The rapid activation of the mechanistic target of rapamycin complex-1 (mTORC1) by growth factors is increased by extracellular amino acids through yet-undefined mechanisms of amino acid transfer into endolysosomes. Because the endocytic process of macropinocytosis concentrates extracellular solutes into endolysosomes and is increased in cells stimulated by growth factors or tumor-promoting phorbol esters, we analyzed its role in amino acid–dependent activation of mTORC1. Here, we show that growth factor-dependent activation of mTORC1 by amino acids, but not glucose, requires macropinocytosis. In murine bone marrow–derived macrophages and murine embryonic fibroblasts stimulated with their cognate growth factors or with phorbol myristate acetate, activation of mTORC1 required an Akt-independent vesicular pathway of amino acid delivery into endolysosomes, mediated by the actin cytoskeleton. Macropinocytosis delivered small, fluorescent fluid-phase solutes into endolysosomes sufficiently fast to explain growth factor–mediated signaling by amino acids. Therefore, the amino acid–laden macropinosome is an essential and discrete unit of growth factor receptor signaling to mTORC1.
Prion aggregate structure in yeast cells is determined by the Hsp104-Hsp110 disaggregase machinery
Authors: O’Driscoll Jonathan , Clare Daniel , Saibil Helen
Published: October 2015

Prions consist of misfolded proteins that have adopted an infectious amyloid conformation. In vivo, prion biogenesis is intimately associated with the protein quality control machinery. Using electron tomography, we probed the effects of the heat shock protein Hsp70 chaperone system on the structure of a model yeast [PSI+] prion in situ. Individual Hsp70 deletions shift the balance between fibril assembly and disassembly, resulting in a variable shell of nonfibrillar, but still immobile, aggregates at the surface of the [PSI+] prion deposits. Both Hsp104 (an Hsp100 disaggregase) and Sse1 (the major yeast form of Hsp110) were localized to this surface shell of [PSI+] deposits in the deletion mutants. Elevation of Hsp104 expression promoted the appearance of this novel, nonfibrillar form of the prion aggregate. Moreover, Sse1 was found to regulate prion fibril length. Our studies reveal a key role for Sse1 (Hsp110), in cooperation with Hsp104, in regulating the length and assembly state of [PSI+] prion fibrils in vivo.
Oxysterols and EBI2 promote osteoclast precursor migration to bone surfaces and regulate bone mass homeostasis
Authors: Nevius Erin , Pinho Flavia , Dhodapkar Meera , Jin Huiyan , Nadrah Kristina , Horowitz Mark C. , Kikuta Junichi , Ishii Masaru , Pereira João P.
Published: October 2015

Bone surfaces attract hematopoietic and nonhematopoietic cells, such as osteoclasts (OCs) and osteoblasts (OBs), and are targeted by bone metastatic cancers. However, the mechanisms guiding cells toward bone surfaces are essentially unknown. Here, we show that the Gαi protein–coupled receptor (GPCR) EBI2 is expressed in mouse monocyte/OC precursors (OCPs) and its oxysterol ligand 7α,25-dihydroxycholesterol (7α,25-OHC) is secreted abundantly by OBs. Using in vitro time-lapse microscopy and intravital two-photon microscopy, we show that EBI2 enhances the development of large OCs by promoting OCP motility, thus facilitating cell–cell interactions and fusion in vitro and in vivo. EBI2 is also necessary and sufficient for guiding OCPs toward bone surfaces. Interestingly, OCPs also secrete 7α,25-OHC, which promotes autocrine EBI2 signaling and reduces OCP migration toward bone surfaces in vivo. Defective EBI2 signaling led to increased bone mass in male mice and protected female mice from age- and estrogen deficiency–induced osteoporosis. This study identifies a novel pathway involved in OCP homing to the bone surface that may have significant therapeutic potential.
Detailed structure of the outer disk around HD 169142 with polarized light in H-band
Authors: Momose Munetake , Morita Ayaka , Fukagawa Misato , Muto Takayuki , Takeuchi Taku , Hashimoto Jun , Honda Mitsuhiko , Kudo Tomoyuki , Okamoto Yoshiko K. , Kanagawa Kazuhiro D. , Tanaka Hidekazu , Grady Carol A. , Sitko Michael L. , Akiyama Eiji , Currie Thayne , Follette Katherine B. , Mayama Satoshi , Kusakabe Nobuhiko , Abe Lyu , Brandner Wolfgang , Brandt Timothy D. , Carson Joseph C. , Egner Sebastian , Feldt Markus , Goto Miwa , Guyon Olivier , Hayano Yutaka , Hayashi Masahiko , Hayashi Saeko S. , Henning Thomas , Hodapp Klaus W. , Ishii Miki , Iye Masanori , Janson Markus , Kandori Ryo , Knapp Gillian R. , Kuzuhara Masayuki , Kwon Jungmi , Matsuo Taro , McElwain Michael W. , Miyama Shoken , Morino Jun-Ichi , Moro-Martin Amaya , Nishimura Tetsuo , Pyo Tae-Soo , Serabyn Eugene , Suenaga Takuya , Suto Hiroshi , Suzuki Ryuji , Takahashi Yasuhiro H. , Takami Michihiro , Takato Naruhisa , Terada Hiroshi , Thalmann Christian , Tomono Daigo , Turner Edwin L. , Watanabe Makoto , Wisniewski John , Yamada Toru , Takami Hideki , Usuda Tomonori , Tamura Motohide
Published: October 2015

Coronagraphic imagery of the circumstellar disk around HD 169142 in H-band polarized intensity (PI) with Subaru/HiCIAO is presented. The emission scattered by dust particles at the disk surface in 0${^{\prime\prime}_{.}}$2 ≤ r ≤ 1${^{\prime\prime}_{.}}$2, or 29 ≤ r ≤ 174 au, is successfully detected. The azimuthally averaged radial profile of the PI shows a double power-law distribution, in which the PIs in r = 29–52 au and r = 81.2–145 au respectively show r−3 dependence. These two power-law regions are connected smoothly with a transition zone (TZ), exhibiting an apparent gap in r = 40–70 au. The PI in the inner power-law region shows a deep minimum whose location seems to coincide with the point source at λ = 7 mm. This can be regarded as another sign of a protoplanet in the TZ. The observed radial profile of the PI is reproduced by a minimally flaring disk with an irregular surface density distribution, an irregular temperature distribution, or with a combination of both. The depletion factor of surface density in the inner power-law region (r < 50 au) is derived to be ≥ 0.16 from a simple model calculation. The obtained PI image also shows small-scale asymmetries in the outer power-law region. Possible origins for these asymmetries include corrugation of the scattering surface in the outer region, and a shadowing effect by a puffed-up structure in the inner power-law region.
How does a secular instability grow in a hyperaccretion flow?
Authors: Kimura Mariko , Mineshige Shin , Kawanaka Norita
Published: October 2015

Hyperaccretion flows with mass accretion rates far above the Eddington rate have an N-shaped equilibrium curve on the Σ–$\skew{3}\dot{M}$ plane (with Σ and $\skew{3}\dot{M}$ being surface density and mass accretion rate, respectively). The accretion flow on the lower Σ branch of the N-shape is optically thick, advection-dominated accretion flow, while that on the upper one is neutrino-dominated accretion flow. The middle branch has a negative slope on the Σ–$\skew{3}\dot{M}$ plane, meaning that the flow on this branch is secularly unstable. To investigate how the instability affects the flow structure and what observable signatures are produced, we study the time evolution of the unstable hyperaccretion flow in response to variable mass injection rates by solving the height-averaged equations for viscous accretion flows. When a transition occurs from the lower branch to the upper branch (or from the upper branch to the lower branch), the surface density rapidly increases (decreases) around that transition region, which induces locally enhanced mass flow (referred to as non-steady mass flow) into (out of) that region. We confirm that the non-steady flow can create a kind of disturbance and that it propagates over the whole disk. However, the non-steady mass flow is not strong enough to induce coherent transition over the whole disk, unless the mass injection rate varies with time. When the injection rate continuously changes, the neutrino luminosity varies intermittently, thus producing step-function-like light curves, as the radiation efficiency discontinuously changes every time the local transition occurs. The effects of changing the N-shape and possible observational consequences on the gamma-ray burst emission are briefly discussed.
Penetration Peg Formation and Invasive Hyphae Development Require Stage-Specific Activation of MoGTI1 in Magnaporthe oryzae
Authors: Li Yang , Wang Guanghui , Xu Jin-Rong , Jiang Cong
Published: October 2015

The hemibiotrophic pathogen Magnaporthe oryzae causes one of the most destructive diseases in cultivated rice. Complex infection-related morphogenesis and production of various effectors are known to be important for successful colonization and disease development. In this study, we characterized the activation of the MoGTI1 transcription factor and its role in infection-related morphogenesis and effector gene expression. The Mogti1 mutant was nonpathogenic, although it was normal in appressorium formation and turgor generation. Close examination showed that Mogti1 was defective in penetration and growth of normal invasive hyphae. Deletion of MoGTI1 affected the expression of the majority of effector genes. The expression of MoGti1 appeared to be controlled by the Mps1 but not Pmk1 mitogen-activated protein kinase (MAPK), and the mps1 and Mogti1 mutants had similar phenotypes in plant infection and cell wall integrity defects. However, lack of MAPK phosphorylation sites and dispensability of the putative MAPK docking site suggested that MoGti1 is not a direct target of Mps1. Site-specific mutagenesis analyses showed that the putative protein kinase A phosphorylation site was not essential for localization of MoGti1 to the nucleus but important for its normal function. Although the cyclin-dependent kinase (CDK) phosphorylation site of MoGti1 is dispensable during vegetative growth and appressorium formation, the S77A mutation affected penetration and invasive growth. Localization of MoGti1S77A-green fluorescent protein to the nucleus in late stages of appressorium formation and during invasive growth was not observed, suggesting a stage-specific CDK phosphorylation of MoGti1. Overall, our data indicate that Mps1 may indirectly regulate the expression of MoGti1 in maintaining cell wall integrity, conidiation, and plant infection. MoGti1 is likely a stage-specific target of CDK and plays a crucial role in effector gene expression and morphogenesis related to the development of penetration pegs and invasive hyphae.
Can Abdominal Hypopressive Technique Change Levator Hiatus Area?
Authors: Resende Ana Paula Magalhães , Torelli Luiza , Zanetti Miriam Raquel Diniz , Petricelli Carla Dellabarba , Jármy-Di Bella Zsuzsanna IIona Katalin , Nakamura Mary Uchiyama , Júnior Edward Araujo , Moron Antonio Fernandes , Girão Manoel João Batista Castello , Sartori Marair Gracio Ferreira
Published: October 2015

This study aimed to evaluate the levator hiatus area (LHA) at rest and during the performance of maximal pelvic floor muscle (PFM) contractions, during the abdominal hypopressive technique (AHT), and during the combination of PFM contractions (PFMCs) and the AHT. The study included 17 healthy nulliparous women who had no history of pelvic floor disorders. The LHA was evaluated with the patients in the lithotomy position. After a physiotherapist instructed the patients on the proper performance of the PFM and AHT exercises, 1 gynecologist performed the 3-dimensional translabial ultrasound examinations. The LHA was measured with the patients at rest. The PFMC alone, the AHT alone or the AHT in combination with a PFMC with 30 seconds of rest between the evaluations were performed. Each measurement was performed 2 times, and the mean value was used for statistical analysis. The Wilcoxon test was used to test the differences between the 2 maneuvers. Similar values were observed when comparing the LHA of the PFM at rest (12.2 ± 2.4) cm2 and during the AHT (11.7 ± 2.6) cm2 (P = 0.227). The AHT+ PFMC (10.2 ± 1.9) cm2 demonstrated lower values compared with AHT alone (11.7 ± 2.6) cm2 (P = 0.002). When comparing the PFMC (10.4 ± 2.1) cm2 with the AHT + PFMC (10.2 ± 1.9) cm2, no significant difference (P = 0.551) was observed. During PFMC, the constriction was 1.8 cm2; during the AHT, the constriction was 0.5 cm2; and during the AHT + PFMC, it was 2 cm2. The LHA assessed by 3-dimensional ultrasound did not significantly change with AHT. These results support the theory that AHT does not strengthen PFM.
The impact of parametrized convection on cloud feedback
Authors: Webb Mark J. , Lock Adrian P. , Bretherton Christopher S. , Bony Sandrine , Cole Jason N. S. , Idelkadi Abderrahmane , Kang Sarah M. , Koshiro Tsuyoshi , Kawai Hideaki , Ogura Tomoo , Roehrig Romain , Shin Yechul , Mauritsen Thorsten , Sherwood Steven C. , Vial Jessica , Watanabe Masahiro , Woelfle Matthew D. , Zhao Ming
Published: October 2015

We investigate the sensitivity of cloud feedbacks to the use of convective parametrizations by repeating the CMIP5/CFMIP-2 AMIP/AMIP + 4K uniform sea surface temperature perturbation experiments with 10 climate models which have had their convective parametrizations turned off. Previous studies have suggested that differences between parametrized convection schemes are a leading source of inter-model spread in cloud feedbacks. We find however that ‘ConvOff’ models with convection switched off have a similar overall range of cloud feedbacks compared with the standard configurations. Furthermore, applying a simple bias correction method to allow for differences in present-day global cloud radiative effects substantially reduces the differences between the cloud feedbacks with and without parametrized convection in the individual models. We conclude that, while parametrized convection influences the strength of the cloud feedbacks substantially in some models, other processes must also contribute substantially to the overall inter-model spread. The positive shortwave cloud feedbacks seen in the models in subtropical regimes associated with shallow clouds are still present in the ConvOff experiments. Inter-model spread in shortwave cloud feedback increases slightly in regimes associated with trade cumulus in the ConvOff experiments but is quite similar in the most stable subtropical regimes associated with stratocumulus clouds. Inter-model spread in longwave cloud feedbacks in strongly precipitating regions of the tropics is substantially reduced in the ConvOff experiments however, indicating a considerable local contribution from differences in the details of convective parametrizations. In both standard and ConvOff experiments, models with less mid-level cloud and less moist static energy near the top of the boundary layer tend to have more positive tropical cloud feedbacks. The role of non-convective processes in contributing to inter-model spread in cloud feedback is discussed.
The inconstancy of the transient climate response parameter under increasing CO2
Authors: Gregory J. M. , Andrews T. , Good P.
Published: October 2015

In the Coupled Model Intercomparison Project Phase 5 (CMIP5), the model-mean increase in global mean surface air temperatureTunder the 1pctCO2 scenario (atmospheric CO2increasing at 1% yr−1) during the second doubling of CO2is 40% larger than the transient climate response (TCR), i.e. the increase inTduring the first doubling. We identify four possible contributory effects. First, the surface climate system loses heat less readily into the ocean beneath as the latter warms. The model spread in the thermal coupling between the upper and deep ocean largely explains the model spread in ocean heat uptake efficiency. Second, CO2radiative forcing may rise more rapidly than logarithmically with CO2concentration. Third, the climate feedback parameter may decline as the CO2concentration rises. With CMIP5 data, we cannot distinguish the second and third possibilities. Fourth, the climate feedback parameter declines as time passes orTrises; in 1pctCO2, this effect is less important than the others. We find thatTprojected for the end of the twenty-first century correlates more highly withTat the time of quadrupled CO2in 1pctCO2 than with the TCR, and we suggest that the TCR may be underestimated from observed climate change.
Weighting climate model projections using observational constraints
Authors: Gillett Nathan P.
Published: October 2015

Projected climate change integrates the net response to multiple climate feedbacks. Whereas existing long-term climate change projections are typically based on unweighted individual climate model simulations, as observed climate change intensifies it is increasingly becoming possible to constrain the net response to feedbacks and hence projected warming directly from observed climate change. One approach scales simulated future warming based on a fit to observations over the historical period, but this approach is only accurate for near-term projections and for scenarios of continuously increasing radiative forcing. For this reason, the recent Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR5) included such observationally constrained projections in its assessment of warming to 2035, but used raw model projections of longer term warming to 2100. Here a simple approach to weighting model projections based on an observational constraint is proposed which does not assume a linear relationship between past and future changes. This approach is used to weight model projections of warming in 2081–2100 relative to 1986–2005 under the Representative Concentration Pathway 4.5 forcing scenario, based on an observationally constrained estimate of the Transient Climate Response derived from a detection and attribution analysis. The resulting observationally constrained 5–95% warming range of 0.8–2.5 K is somewhat lower than the unweighted range of 1.1–2.6 K reported in the IPCC AR5.
Feedbacks, climate sensitivity and the limits of linear models
Authors: Knutti Reto , Rugenstein Maria A. A.
Published: October 2015

The term ‘feedback’ is used ubiquitously in climate research, but implies varied meanings in different contexts. From a specific process that locally affects a quantity, to a formal framework that attempts to determine a global response to a forcing, researchers use this term to separate, simplify and quantify parts of the complex Earth system. We combine new model results with a historical and educational perspective to organize existing ideas around feedbacks and linear models. Our results suggest that the state- and forcing-dependency of feedbacks are probably not appreciated enough, and not considered appropriately in many studies. A non-constant feedback parameter likely explains some of the differences in estimates of equilibrium climate sensitivity from different methods and types of data. Clarifying the value and applicability of the linear forcing feedback framework and a better quantification of feedbacks on various timescales and spatial scales remains a high priority in order to better understand past and predict future changes in the climate system.
Genome sequence comparisons of serial multi-drug-resistant Mycobacterium tuberculosis isolates over 21 years of infection in a single patient
Authors: Meumann Ella M. , Globan Maria , Fyfe Janet A. M. , Leslie David , Porter Jessica L. , Seemann Torsten , Denholm Justin , Stinear Timothy P.
Published: October 2015

We report a case of chronic pulmonary multi-drug-resistant tuberculosis. Despite 14 years of treatment, Mycobacterium tuberculosis was persistently isolated from sputum. Following treatment cessation the patient remained well, although M. tuberculosis was isolated from sputum for a further 8 years. Genome sequencing of eight serial M. tuberculosis isolates cultured between 1991 and 2011 revealed 17 mutations (0.8 mutations per genome year− 1). Eight of these were persisting mutations and only two mutations were detected in the 7 years following cessation of treatment in 2004. In four isolates there were mixed alleles, suggesting the likely presence of bacterial subpopulations. The initial 1991 isolate demonstrated genotypic resistance to isoniazid (katG W91R), rifampicin (rpoB S531L), ethambutol (embB M306V), streptomycin (gidB L16R), quinolones (gyrA S95T) and P-aminosalicylic acid (thyA T202A). Subsequent resistance mutations developed for pyrazinamide (pncA I31F) and ethionamide (ethA frameshift). Such information might have been instructive when developing a treatment regimen. In retrospect and with the benefit of high-resolution genomic hindsight we were able to determine that the patient received only one or two active anti-tuberculous agents for most of their treatment. Additionally, mutations in bacA and Rv2326c were detected, which may have contributed to the persistent but mild disease course. BacA is likely to be associated with maintenance of chronic infection and Rv2326c with a decreased bacterial metabolic state. These results expand our understanding of M. tuberculosis evolution during human infection and underline the link between antibiotic resistance and clinical persistence.
Aquatic insects of a lowland rainforest in Papua New Guinea: assemblage structure in relation to habitat type
Authors: Klecka Jan
Published: October 2015

Papua New Guinea is one of the most valuable tropical regions but ecological research of its freshwater invertebrates has been lacking. The goal of this paper is to evaluate the species richness, diversity and structure of aquatic insect assemblages in different habitats in the Wanang River catchment in a well-preserved lowland rainforest. Assemblage structure was studied on two spatial scales – in different habitats (river, streams and stagnant pools) and in three mesohabitats in the river (slow and fast sections and submerged wood). The results show that headwater streams had the highest morphospecies diversity, while the river had the highest insect abundance. Slow and fast sections of the river differed both in terms of insect abundance and diversity. Furthermore, a number of unique wood-associated species was found on submerged wood. The most notable feature of the assemblage structure was scarcity of shredders and dominance of predators. However, predatory beetles, bugs and dragonfly larvae exhibited contrasting habitat preferences. This study shows that Papua New Guinean lowland rainforests host diverse and distinctly structured freshwater insect assemblages.
Crystal structure ofN′-[(E)-3,5-dichloro-2-hydroxybenzylidene]-4-nitrobenzohydrazide dimethylformamide monosolvate
Authors: Joseph Bibitha , Sajitha N. R. , Sithambaresan M. , Seena E. B. , Kurup M. R. Prathapachandra
Published: October 2015

In the title compound, C14H9Cl2N3O4·C3H7NO, the hydrazone molecule adopts anEconformation with respect to azomethine bond, and the dihedral angle between the two aromatic rings [8.96 (11)°] shows that the rings are almost co-planar. The planar conformation of the molecule is stabilized by the intramolecular O—H...N hydrogen bond involving the OH group and azomethine N atom. The azomethine and keto bond distances [1.269 (2) and 1.210 (2) Å, respectively] are very close to the formal C=N and C=O bond lengths. The dimethylformamide solvent molecule is connected to the hydrazone NH groupviaan N—H...O hydrogen bond. In the crystal, non-classical C—H...O and C—H...Cl hydrogen bonds link the molecules into chains along [322]. A supramolecular three-dimensional architecture is created by weak C—Cl...π [4.163 (3) Å, 83.26 (9)°] and π–π [centroid–centroid distance = 4.0395 (14) Å] interactions.
Managing distribution networks in emerging markets. Evidence from the furniture sector
Authors: Bortoluzzi Guido , Chiarvesio Maria , Tabacco Raffaella
Published: October 2015

Purpose

– This paper aims to examine how three firms set up distribution networks in China and India. The authors highlight the criticalities in this process and the modifications necessary to adapt the firms’ distribution networks to the local conditions of both markets. Firms entering emerging markets (EMs) must deal with specific business and environmental conditions that can jeopardise their ability to succeed. The establishment of a proper distribution network is among the most pressing priorities for entering firms.

Design/methodology/approach

– The case study approach was used to analyse three European firms in the furniture sector.

Findings

– The results show that several adaptations of already-tested solutions were necessary to cope with the specificities of both markets. Such adaptations differently involved the three layers that form the firms’ distribution network: actors, activities and resources. Theoretical and managerial implications are derived from the results.

Research limitations/implications

– This paper considers only three firms, which belong to the same sector and target a similar market segment (the high-end market). Therefore, the conclusions can be generalised only under certain conditions.

Originality/value

– This paper contributes to the development of international marketing literature by specifically studying distribution networks in EM contexts.