bluuebunny/crossref_metadata_2025 huggingface dataset:
Force field for ZIF-8 flexible frameworks: atomistic simulation of adsorption, diffusion of pure gases as CH4, H2, CO2 and N2
Authors: Wu Xuanjun , Huang Jin , Cai Weiquan , Jaroniec Mietek
Published: February 2014

A full set of flexible force field parameters for ZIF-8, applied for its gas adsorption and diffusion, has been presented.
Fabrication of biocompatible high aspect ratio Au–Ni coaxial nanorod arrays using the electroless galvanic displacement reaction method
Authors: Hsu Che-Wei , Li Ching-Wen , Wang Gou-Jen
Published: February 2014

Biocompatible Au–Ni coaxial nanorod arrays, which enable a precise control of its stiffness (softness) by adjusting the array height, have been demonstrated to be able to manipulate the differentiation of endothelial cells (ECs) on the array surface.
Rapid phosphine-free synthesis of CdSe quantum dots: promoting the generation of Se precursors using a radical initiator
Authors: Hou Bo , Benito-Alifonso David , Webster Richard , Cherns David , Galan M. Carmen , Fermín David J.
Published: February 2014

Trace amounts of AIBN substantially accelerate the homolytic cleavage of the Se–Se bond, facilitating the phosphine-free synthesis of CdSe quantum dots.
Decreasing reflection through the mutually positive effects of nanograss and nanopillars
Authors: Lin C. H. , Shieh J. , Liang C. C. , Cheng C. C. , Chen Y. C.
Published: February 2014

A combination of a nanograss and a nanopillar array provides mutually enhanced antireflection performance.
Accommodating Dual Sensory Loss in Everyday Practice
Authors: Echt Katharina V. , Saunders Gabrielle H.
Published: February 2014

Dual sensory impairment is increasingly prevalent in people over age 65. The combination of vision loss and hearing loss impacts not only day-to-day function from the perspective of the patient, but must also be considered by the speech-language pathologist working with older people in health care settings. This article will discuss the implications of dual sensory impairment for both patients and professionals, and will provide strategies to support communication.
My Gray is Golden: Thoughts About Aging From the Perspective of Adults With Neurologically Based Communication Impairments
Authors: Wallace Gloriajean L.
Published: February 2014

Aging with disability may follow several trajectories, depending on the nature of the disability, the age of onset, the individual differences in the person, and the support systems available. This article will discuss theories of aging and loss together with various neurological diagnoses, where the two conditions (aging and neurological condition) lead to individual differences in coping, compensation, and outcome.
Wideband bandpass filter based on ring resonator with high selectivity and multiple transmission zeros
Authors: Zhou J.G. , Chiang Y.C. , Che W.Q.
Published: February 2014

A high‐selectivity wideband bandpass filter consisting of a ring resonator and stepped impedance resonators is proposed. A wideband bandpass filter with multiple transmission poles and transmission zeros is obtained. For demonstration, a prototype operating at the frequency band of 4.14–9.56 GHz (with a fractional bandwidth of 79.1%) is designed and fabricated. Good agreements between the simulated and the measured results have been observed, indicating a very sharp out‐of‐band rejection.
Economic power dispatch with cubic cost models using teaching learning algorithm
Authors: Elanchezhian E.B. , Subramanian S. , Ganesan S.
Published: February 2014

Economic dispatch (ED) solution accuracy can be improved with cubic cost models and optimisation algorithms. This article proposes a new methodology for solving ED problem with cubic cost models using teaching learning‐based optimisation (TLBO) algorithm. The key aspects of ED scenario such as valve point effects, environmental factors, transmission losses, spinning reserve, ramp rate, prohibited operating zones and fuel limitations are considered in this study. The proposed methodology is applied to test systems involving cubic cost equations in 3, 5, 6, 13, 26 and a large‐scale system containing 156 units, in order to evaluate its efficiency and feasibility. Convergence characteristics of the TLBO has been assessed and investigated through comparison with results reported in the literature. Many trials with different initial values have been carried out for all the test systems in order to justify the robustness of the proposed methodology. Considering the quality of the solution and convergence speed obtained, this method seems to be a promising alternative approach for solving the ED problems with cubic functions.
Application of random search method for maximum power point tracking in partially shaded photovoltaic systems
Authors: Sundareswaran Kinattingal , Peddapati Sankar , Palani S.
Published: February 2014

The power–voltage (P–V) curve of a photovoltaic (PV) power generation system under partially shaded conditions (PSCs) is largely non‐linear and multimodal, and hence, global optimisation techniques are required for maximum power point tracking. A traditional optimisation algorithm is proposed here, namely random search method (RSM) for tracking the global maximum power point in a solar power system under PSC. The RSM is based on the use of random numbers in finding the global optima and is a gradient independent method. The major advantage of RSM is its very simple computational steps, which requires very less memory. The performance of RSM in tracking the peak power is studied for a variety of shading patterns and the tracking performance is compared with two‐stage perturb and observe (P&O) and population‐based particle swarm optimisation (PSO) methods. The simulation results strongly suggest that the RSM is far superior to two‐stage P&O method and better than PSO method. Experimental results obtained from a 120‐watt prototype PV system validate the effectiveness of the proposed scheme.
Turbulent boundary layer flow over transverse aerodynamic roughness transitions: Induced mixing and flow characterization
Authors: Willingham David , Anderson William , Christensen Kenneth T. , Barros Julio M.
Published: February 2014

In studies of turbulent boundary layers at high Reynolds number, the term “roughness transition” is generally an implicit reference to the case of a streamwise step-change in roughness length (whether the roughness length is associated with surface fluxes of momentum, temperature, humidity, or some other quantity). This roughness configuration and flow response has received broad attention. Here, in contrast, we consider turbulent wall-bounded flows over transverse roughness transitions using large-eddy simulation. This is accomplished simply by aligning the boundary layer freestream direction parallel to momentum roughness length transitions, instead of perpendicular. In the present cases, the bounding surface is composed of two “high roughness” strips placed between three “low roughness” strips. The influences of two parameters are evaluated: (1) λ, the ratio of the high roughness length to the low roughness length; and (2) Ls, the width of the high roughness strips. In the immediate vicinity of the roughness change, the abrupt wallstress variation induces transverse turbulent mixing which is the source of a δ-scale secondary flow, recently described as a low momentum pathway (LMP) by Mejia-Alvarez et al. [“Structural attributes of turbulent flow over a complex topography,” Coherent Flow Structures at the Earth's Surface (Wiley-Blackwell, 2013), Chap. 3, pp. 25–42] and Mejia-Alvarez and Christensen [“Wall-parallel stereo PIV measurements in the roughness sublayer of turbulent flow overlying highly-irregular roughness,” Phys. Fluids, 25, 115109]. LMPs are spatially stationary and flanked by δ-scale counter-rotating vortices which serve to pump fluid vertically from the wall, ultimately leading to a spanwise variation in the boundary layer depth (for flows over surface roughness with a converging-diverging riblet pattern, spanwise variation of δ was also found in recent experiments by Nugroho et al. [“Large-scale spanwise periodicity in a turbulent boundary layer induced by highly ordered and direction surface roughness,” Int. J. Heat Fluid Flow 41, 90–102 (2013)]. Mean velocity and transverse Reynolds stresses are used to determine the mixing length associated with transverse mixing. In general, we find that variations in Ls and λ have a strong and mild impact on the secondary flow pattern, respectively.
Complementary system for long term measurements of radon exhalation rate from soil
Authors: Mazur J. , Kozak K.
Published: February 2014

A special set-up for continuous measurements of radon exhalation rate from soil is presented. It was constructed at Laboratory of Radiometric Expertise, Institute of Nuclear Physics Polish Academy of Sciences (IFJ PAN), Krakow, Poland. Radon exhalation rate was determined using the AlphaGUARD PQ2000 PRO (Genitron) radon monitor together with a special accumulation container which was put on the soil surface during the measurement. A special automatic device was built and used to raise and lower back onto the ground the accumulation container. The time of raising and putting down the container was controlled by an electronic timer. This set-up made it possible to perform 4–6 automatic measurements a day. Besides, some additional soil and meteorological parameters were continuously monitored. In this way, the diurnal and seasonal variability of radon exhalation rate from soil can be studied as well as its dependence on soilproperties and meteorological conditions.
Hermitian Young operators
Authors: Keppeler Stefan , Sjödahl Malin
Published: February 2014

Starting from conventional Young operators, we construct Hermitian operators which project orthogonally onto irreducible representations of the (special) unitary group.
Seed influence on the ferromagnetic resonance response of Co/Ni multilayers
Authors: Sabino Maria Patricia Rouelli , Tran Michael , Hin Sim Cheow , Ji Feng Ying , Eason Kwaku
Published: February 2014

The effect of Pd and Ru seed layers on the magnetic properties of [Co/Ni]N multilayers with varying number of bilayer repeats N is investigated using vector network analyzer ferromagnetic resonance. The effective anisotropy field HKeff is found to increase with N for Ru seed, but decreases for Pd until N = 15. As N is increased beyond 15, HKeff decreases for both seeds. In contrast, the damping parameter α decreases with N regardless of the seed, showing a 1/N dependence. Taking spin pumping into account, the intrinsic damping α0 for both Pd and Ru seeds reduce to α0 ≈ 0.01. These results demonstrate that there can be a strong influence of the seed/Co interface on anisotropy, especially for sufficiently low N, but not necessarily on α0.
Positive correlation between coercivity and ferromagnetic resonance extrinsic linewidth in FeCoV/SiO2 films
Authors: Wei Yajun , Brucas Rimantas , Gunnarsson Klas , Celinski Zbigniew , Svedlindh Peter
Published: February 2014

Dynamic magnetic properties of Fe49Co49V2 thin films grown on Si/SiO2 substrates have been studied by using ferromagnetic resonance technique. The effective Landé g-factor, extrinsic linewidth, and Gilbert relaxation rate are all found to decrease in magnitude with increasing sample growth temperature from 20 °C to about 400–500 °C and then on further increase of the growth temperature to increase in magnitude. Samples grown at about 400–450 °C display the smallest coercivity, while the smallest value of the Gilbert relaxation rate of about 0.1 GHz is obtained for samples grown at 450–500 °C. An almost linear relation between extrinsic linewidth and coercivity is observed, which suggests a positive correlation between magnetic inhomogeneity, coercivity, and extrinsic linewidth. The Gilbert relaxation is found to decrease with increasing lattice constant, which is ascribed to the degree of structural order in the films.
Quantum mechanical effects from deformation theory
Authors: Much A.
Published: February 2014

We consider deformations of quantum mechanical operators by using the novel construction tool of warped convolutions. The deformation enables us to obtain several quantum mechanical effects where electromagnetic and gravitomagnetic fields play a role. Furthermore, a quantum plane can be defined by using the deformation techniques. This in turn gives an experimentally verifiable effect.
Observation of coherent oscillations in plasma-enhanced atomic layer deposition Ag films
Authors: Compton Ryan , Prokes S. M. , Glembocki Orest J. , Pala Irina R. , Gerardi Helen K. , Owrutsky Jeffrey C.
Published: February 2014

Acoustic oscillations were observed in ultrafast transient absorption of nanostructured Ag films produced by plasma-enhanced atomic layer deposition (PEALD). The oscillations are attributed to modulations of localized surface plasmon resonance (SPR) bands that naturally arise in the PEALD films and can be described as two lateral modes (∼50 and 100 GHz) with different dephasing times. Contributions from electron-phonon coupling and lattice dynamics in the transient response vary systematically with the probe wavelength relative to the SPR maximum (500–1000 nm).
Smooth local subspace projection for nonlinear noise reduction
Authors: Chelidze David
Published: February 2014

Many nonlinear or chaotic time series exhibit an innate broad spectrum, which makes noise reduction difficult. Local projective noise reduction is one of the most effective tools. It is based on proper orthogonal decomposition (POD) and works for both map-like and continuously sampled time series. However, POD only looks at geometrical or topological properties of data and does not take into account the temporal characteristics of time series. Here, we present a new smooth projective noise reduction method. It uses smooth orthogonal decomposition (SOD) of bundles of reconstructed short-time trajectory strands to identify smooth local subspaces. Restricting trajectories to these subspaces imposes temporal smoothness on the filtered time series. It is shown that SOD-based noise reduction significantly outperforms the POD-based method for continuously sampled noisy time series.
Note: Benign and reproducible preparation of titanium tips
Authors: Awez Mohammad A. , Arnott Z. L. , Wang Y. , Kruse P.
Published: February 2014

Fabrication of titanium tips via electrochemical etching is commonly hindered by the formation of a tough oxide layer. A new one-step approach based on dc etching in a non-aqueous electrolyte is presented. The electrochemical tip etching was carried out at 20 V in a benign etchant of 1M NaCl in ethylene glycol. Tip radii below 100 nm are demonstrated using current cut-off control and approaching 150 nm without cut-off control. The simplicity and efficiency of the approach eliminates pre and post electropolishing steps due to the electropolishing capability of a NaCl-ethylene glycol based electrolyte.
Highly efficient inverted top emitting organic light emitting diodes using a transparent top electrode with color stability on viewing angle
Authors: Kim Jung-Bum , Lee Jeong-Hwan , Moon Chang-Ki , Kim Jang-Joo
Published: February 2014

We report a highly efficient phosphorescent green inverted top emitting organic light emitting diode with excellent color stability by using the 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile/indium zinc oxide top electrode and bis(2-phenylpyridine)iridium(III) acetylacetonate as the emitter in an exciplex forming co-host system. The device shows a high external quantum efficiency of 23.4% at 1000 cd/m2 corresponding to a current efficiency of 110 cd/A, low efficiency roll-off with 21% at 10 000 cd/m2 and low turn on voltage of 2.4 V. Especially, the device showed very small color change with the variation of Δx = 0.02, Δy = 0.02 in the CIE 1931 coordinates as the viewing angle changes from 0° to 60°. The performance of the device is superior to that of the metal/metal cavity structured device.
Nanoscale viscoplastic behavior of smectic liquid crystals and its application in nanolithography
Authors: Schulz Benjamin , Steffen Paul , Bahr Christian
Published: February 2014

We report a unique combination of properties of smectic liquid crystal films that can be described as a viscoplastic behavior on the nanoscale: On the one hand, the films preserve imprinted surface patterns despite being permeated by a directed molecular flow of the film material. On the other hand, their surface morphology can easily be manipulated using an atomic force microscopy tip. Our results demonstrate a controlled molecular-scale deposition of material on the film surface, thereby enabling nanolithographic surface modification of a fluid material.
Photocurrent enhancement of perovskite heterojunction by plasmonic nanoparticles and ferroelectric polarization
Authors: Shieh J. , Chen S. W. , Fang C. Y. , Chen C. H.
Published: February 2014

Perovskite oxides—Pb0.86La0.14TiO3 (PLT), AgNbO3 (ANO), and SrTiO3 (STO)—were deposited consecutively on ITO/glass substrates to form layered composite photoelectrodes. These materials were chosen for their specific electronic band structures to form efficient photocatalytic heterojunctions and similar crystalline structures to minimize interface defects. Two additional methods were adopted to increase the photocurrent density of the composites: (1) plasmonic gold nanoparticles were introduced at the PLT/ITO interface to enhance light scattering and absorption while not becoming electron trapping centers and (2) the ferroelectric PLT layer was electrically poled toward the ANO layer to create a favorable band bending for electron transfer.
Hydrogenation-induced edge magnetization in armchair MoS2 nanoribbon and electric field effects
Authors: Ouyang Fangping , Yang Zhixiong , Ni Xiang , Wu Nannan , Chen Yu , Xiong Xiang
Published: February 2014

We performed density functional theory study on the electronic and magnetic properties of armchair MoS2 nanoribbons (AMoS2NR) with different edge hydrogenation. Although bare and fully passivated AMoS2NRs are nonmagnetic semiconductors, it was found that hydrogenation in certain patterns can induce localized ferromagnetic edge state in AMoS2NRs and make AMoS2NRs become antiferromagnetic semiconductors or ferromagnetic semiconductors. Electric field effects on the bandgap and magnetic moment of AMoS2NRs were investigated. Partial edge hydrogenation can change a small-sized AMoS2NR from semiconductor to metal or semimetal under a moderate transverse electric field. Since the rate of edge hydrogenation can be controlled experimentally via the temperature, pressure and concentration of H2, our results suggest edge hydrogenation is a useful method to engineer the band structure of AMoS2NRs.
Electronic states of NO2-exposed H-terminated diamond/Al2O3 heterointerface studied by synchrotron radiation photoemission and X-ray absorption spectroscopy
Authors: Takahashi Kazutoshi , Imamura Masaki , Hirama Kazuyuki , Kasu Makoto
Published: February 2014

The energy band-lineup and the electronic structure of NO2-exposed H-terminated diamond/Al2O3 heterointerface have been investigated by synchrotron radiation photoemission and x-ray absorption near-edge structure (XANES) measurements. It is found that the energy band-lineup is stagger-type, so-called type-II, with its valence band discontinuity of as high as 3.9 eV and its conduction band discontinuity of 2.7 eV. The valence band maximum of the H-terminated diamond surface is positioned at Fermi level as a result of high-density hole accumulation on the diamond side. The XANES measurement has shown that the oxygen-derived interface state locates at about 1–3 eV above the Fermi level.
Evanescent wave amplification and subwavelength imaging by ultrathin uniaxial μ-near-zero material
Authors: Zhao Yan
Published: February 2014

We demonstrate strong evanescent wave amplification by a thin slab of uniaxial μ-near-zero (UMNZ) material. It is found that while retaining the same amplification effect, the slab can be made arbitrarily thin when the negative permeability along the axis of anisotropy approaches zero. Numerical results show that using a single layer of split-ring resonators (SRRs) with its thickness equal three thousandth of the incident wavelength (λ/3000), a subwavelength source distribution with λ/4 resolution can be transferred to a distance of λ/3.
Concerted control of
Escherichia coli
cell division
Authors: Osella Matteo , Nugent Eileen , Cosentino Lagomarsino Marco
Published: February 2014

Significance

The decisional process controlling cell division is a long-standing question in biology, but the answers were traditionally hindered by limited statistics on single cells. Contemporary experimental tools overcome this problem, but this progress must be combined with new theoretical tools to approach the data. This work introduces a quantitative method for estimating the variables controlling division rate and uses it to construct a minimal model from large-scale dynamic data on the size of dividing
Escherichia coli
cells. Cell size is found to be an important control variable of cell division, but not the sole one. Conversely, a description where division rate is determined jointly by cell size and time into the cell cycle reproduces well the available measurements.
Comparative efficiency and driving range of light- and heavy-duty vehicles powered with biomass energy stored in liquid fuels or batteries
Authors: Laser Mark , Lynd Lee R.
Published: February 2014

Significance

This paper addresses the question, “When using cellulosic biomass for vehicular transportation, which field-to-wheels pathway is more efficient: that using biofuels or that using bioelectricity?” Distinguishing features of this study relative to prior work are the consideration of technological maturity, both in fuel/electricity production and vehicular advancement, as well as the intended transportation application. Whereas prior studies have deemed bioelectricity as being the more efficient option, we find here that, for ranges characteristic of driving patterns in the United States, there is little basis to expect mature bioelectricity-powered vehicles to have greater field-to-wheels efficiency as compared with mature biofuel-powered vehicles.
Suppressing thyroid hormone signaling preserves cone photoreceptors in mouse models of retinal degeneration
Authors: Ma Hongwei , Thapa Arjun , Morris Lynsie , Redmond T. Michael , Baehr Wolfgang , Ding Xi-Qin
Published: February 2014

Significance

Photoreceptors degenerate in a wide array of hereditary retinal diseases and age-related macular degeneration. There is currently no treatment available for retinal degenerations. While outnumbered roughly 20:1 by rods in the human retina, it is the cones that mediate color vision and visual acuity, and their survival is critical for vision. In this communication, we investigate whether thyroid hormone (TH) signaling affects cone viability in retinal degeneration mouse models. TH signaling is known to be important for cone pigment expression and patterning, but excess TH signaling causes death of cones. We demonstrate that suppressing TH signaling in mouse models of cone–rod dystrophy preserves cones. This finding may lead to a novel and substantially different approach for retinal degeneration management.
Rod-like bacterial shape is maintained by feedback between cell curvature and cytoskeletal localization
Authors: Ursell Tristan S. , Nguyen Jeffrey , Monds Russell D. , Colavin Alexandre , Billings Gabriel , Ouzounov Nikolay , Gitai Zemer , Shaevitz Joshua W. , Huang Kerwyn Casey
Published: February 2014

Significance

Across all kingdoms of life, maintaining the correct cell shape is critical for behaviors such as sensing, motility, surface attachment, and nutrient acquisition. Maintaining proper shape requires cellular-scale coordination of proteins and feedback systems that enable responses that correct local morphological perturbations. Here, we demonstrate that the MreB cytoskeleton in
Escherichia coli
preferentially localizes to regions of negative curvature, directing growth away from the poles and actively straightening locally curved regions of the cell. Moreover, our biophysical simulations of curvature-biased growth suggest that cell wall insertion causes surface deformations that could be responsible for the circumferential motion of MreB. Taken together, our work demonstrates that MreB’s local orchestration of persistent, bursty growth enables robust, uniform growth at the cellular scale.
Hybrid-fuel bacterial flagellar motors inEscherichia coli
Authors: Sowa Yoshiyuki , Homma Michio , Ishijima Akihiko , Berry Richard M.
Published: February 2014

Significance

The bacterial flagellar motor is a rotary nano-machine that is driven by an electrochemical ion gradient across the cytoplasmic membrane, either H+or Na+ions. NaturalEscherichia colicells have only H+-driven motors. We demonstrate a genetically engineered hybrid-fuel flagellar motor inE. colithat runs on both types of ion gradient, H+and Na+. The hybrid motors switch between the two types of ion automatically and dynamically in response to external conditions, by swapping the stator components that determine their ion selectivity. These hybrid motors combine biological components with specific functions from different organisms that do not naturally coexist but demonstrate that natural hybrid motors could exist in other species.
Elevated morning cortisol is a stratified population-level biomarker for major depression in boys only with high depressive symptoms
Authors: Owens Matthew , Herbert Joe , Jones Peter B. , Sahakian Barbara J. , Wilkinson Paul O. , Dunn Valerie J. , Croudace Timothy J. , Goodyer Ian M.
Published: February 2014

Significance

Clinical depression is a severe and common illness, characterized primarily by persistent low mood and lack of pleasure in usually enjoyable activities, that results in significant impairment in everyday living. It also involves alterations in cognitive and hormonal functions. There is substantial variation between depressed individuals in terms of the causes and therapeutic response, making it difficult to identify those most likely to benefit from intervention and treatment. We derived subtypes of adolescents in the population based on different levels of the hormone cortisol and subclinical depressive symptoms. A group (17%) with both high levels of cortisol and depressive symptoms of both sexes had more depressed thinking. Boys in this group were at high risk for clinical depression.
State transitions in
Chlamydomonas reinhardtii
strongly modulate the functional size of photosystem II but not of photosystem I
Authors: Ünlü Caner , Drop Bartlomiej , Croce Roberta , van Amerongen Herbert
Published: February 2014

Significance

To optimize their photosynthetic performance, most oxygen-evolving organisms are able to shuttle light-harvesting pigment–protein complexes between photosystems I and II. These photosystems work in series to transform light energy into chemical energy. It is generally accepted that 80% of the light-harvesting complexes is participating in the reorganization in the green alga
Chlamydomonas reinhardtii
, a model organism for photosynthesis research. However, in the present paper, we demonstrate that such a large remodeling does not occur. Light-harvesting complexes can indeed detach from photosystem II, but only a small fraction subsequently attaches to photosystem I, and it is demonstrated how this leads to photoprotection in high-light conditions. This phenomenon has significant implications for our way of thinking about the efficiency regulation in photosynthesis.
Contact between rough surfaces and a criterion for macroscopic adhesion
Authors: Pastewka Lars , Robbins Mark O.
Published: February 2014

Significance

Macroscopic objects rarely stick together, yet the van der Waals interactions between surface atoms produce attractive pressures that are orders of magnitude larger than atmospheric pressure. This “adhesion paradox” has been linked to surface roughness, which reduces the area of intimate atomic contact to summits on the rough landscape. This paper presents a parameter-free theory that captures the interplay between elasticity, interatomic attraction, and surface roughness. It predicts how adhesion changes contact area and when surfaces are sticky. The results offer a simple explanation for why tape sticks to our desktops but a sheet of paper does not, and may aid in the design of adhesives and in engineering surface roughness to enhance or eliminate adhesion.
To keep on track during flight, fruitflies discount the skyward view
Authors: Mazo Chantell , Theobald Jamie C.
Published: February 2014

When small flying insects go off their intended course, they use the resulting pattern of motion on their eye, or optic flow, to guide corrective steering. A change in heading generates a unique, rotational motion pattern and a change in position generates a translational motion pattern, and each produces corrective responses in the wingbeats. Any image in the flow field can signal rotation, but owing to parallax, only the images of nearby objects can signal translation. Insects that fly near the ground might therefore respond more strongly to translational optic flow that occurs beneath them, as the nearby ground will produce strong optic flow. In these experiments, rigidly tethered fruitflies steered in response to computer-generated flow fields. When correcting for unintended rotations, flies weight the motion in their upper and lower visual fields equally. However, when correcting for unintended translations, flies weight the motion in the lower visual fields more strongly. These results are consistent with the interpretation that fruitflies stabilize by attending to visual areas likely to contain the strongest signals during natural flight conditions.
Theoretical analysis of the performance of a foam fractionation column
Authors: Tobin S. T. , Weaire D. , Hutzler S.
Published: February 2014

A model system for theory and experiment which is relevant to foam fractionation consists of a column of foam moving through an inverted U-tube between two pools of surfactant solution. The foam drainage equation is used for a detailed theoretical analysis of this process. In a previous paper, we focused on the case where the lengths of the two legs are large. In this work, we examine the approach to the limiting case (i.e. the effects of finite leg lengths) and how it affects the performance of the fractionation column. We also briefly discuss some alternative set-ups that are of interest in industry and experiment, with numerical and analytical results to support them. Our analysis is shown to be generally applicable to a range of fractionation columns.
Flavan-3-ols in Norway Spruce: Biosynthesis, Accumulation, and Function in Response to Attack by the Bark Beetle-Associated Fungus Ceratocystis polonica
Authors: Hammerbacher Almuth , Paetz Christian , Wright Louwrance P. , Fischer Thilo C. , Bohlmann Joerg , Davis Andrew J. , Fenning Trevor M. , Gershenzon Jonathan , Schmidt Axel
Published: February 2014

Proanthocyanidins (PAs) are common polyphenolic polymers of plants found in foliage, fruit, bark, roots, rhizomes, and seed coats that consist of flavan-3-ol units such as 2,3-trans-(+)-catechin and 2,3-cis-(–)-epicatechin. Although the biosynthesis of flavan-3-ols has been studied in angiosperms, little is known about their biosynthesis and ecological roles in gymnosperms. In this study, the genes encoding leucoanthocyanidin reductase, a branch point enzyme involved in the biosynthesis of 2,3-trans-(+)-flavan-3-ols, were identified and functionally characterized in Norway spruce (Picea abies), the most widespread and economically important conifer in Europe. In addition, the accumulation of flavan-3-ols and PAs was investigated in Norway spruce saplings after wounding or inoculation with the fungal pathogen Ceratocystis polonica, which is vectored by bark beetles (Ips typographus) and is usually present during fatal beetle attacks. Monomeric and dimeric flavan-3-ols were analyzed by reverse-phase high-pressure liquid chromatography, while the size and subunit composition of larger PAs were characterized using a novel acid hydrolysis method and normal phase chromatography. Only flavan-3-ol monomers with 2,3-trans stereochemistry were detected in spruce bark; dimeric and larger PAs contained flavan-3-ols with both 2,3-trans and 2,3-cis stereochemistry. Levels of monomers as well as PAs with a higher degree of polymerization increased dramatically in spruce bark after infection by C. polonica. In accordance with their role in the biosynthesis of 2,3-trans-(+)-flavan-3-ols, transcript abundance of Norway spruce LEUCOANTHOCYANIDIN REDUCTASE genes also increased significantly during fungal infection. Bioassays with C. polonica revealed that the levels of 2,3-trans-(+)-catechin and PAs that are produced in the tree in response to fungal infection inhibit C. polonica growth and can therefore be considered chemical defense compounds.
The bHLH Transcription Factor HBI1 Mediates the Trade-Off between Growth and Pathogen-Associated Molecular Pattern–Triggered Immunity inArabidopsis
Authors: Fan Min , Bai Ming-Yi , Kim Jung-Gun , Wang Tina , Oh Eunkyoo , Chen Lawrence , Park Chan Ho , Son Seung-Hyun , Kim Seong-Ki , Mudgett Mary Beth , Wang Zhi-Yong
Published: February 2014

The trade-off between growth and immunity is crucial for survival in plants. However, the mechanism underlying growth-immunity balance has remained elusive. The PRE-IBH1-HBI1 tripartite helix-loop-helix/basic helix-loop-helix module is part of a central transcription network that mediates growth regulation by several hormonal and environmental signals. Here, genome-wide analyses of HBI1 target genes show that HBI1 regulates both overlapping and unique targets compared with other DNA binding components of the network in Arabidopsis thaliana, supporting a role in specifying network outputs and fine-tuning feedback regulation. Furthermore, HBI1 negatively regulates a subset of genes involved in immunity, and pathogen-associated molecular pattern (PAMP) signals repress HBI1 transcription. Constitutive overexpression and loss-of-function experiments show that HBI1 inhibits PAMP-induced growth arrest, defense gene expression, reactive oxygen species production, and resistance to pathogen. These results show that HBI1, as a component of the central growth regulation circuit, functions as a major node of crosstalk that mediates a trade-off between growth and immunity in plants.
Shifts in microbial community structure and function in light‐ and dark‐grown biofilms driven by warming
Authors: Romaní Anna M. , Borrego Carles M. , Díaz‐Villanueva Verónica , Freixa Anna , Gich Frederic , Ylla Irene
Published: February 2014

Biofilms are dynamic players in biogeochemical cycling in running waters and are subjected to environmental stressors like those provoked by climate change. We investigated whether a 2°C increase in flowing water would affect prokaryotic community composition and heterotrophic metabolic activities of biofilms grown under light or dark conditions. Neither light nor temperature treatments were relevant for selecting a specific bacterial community at initial phases (7‐day‐old biofilms), but both variables affected the composition and function of mature biofilms (28‐day‐old). In dark‐grown biofilms, changes in the prokaryotic community composition due to warming were mainly related to rotifer grazing, but no significant changes were observed in functional fingerprints. In light‐grown biofilms, warming also affected protozoan densities, but its effect on prokaryotic density and composition was less evident. In contrast, heterotrophic metabolic activities in light‐grown biofilms under warming showed a decrease in the functional diversity towards a specialized use of several carbohydrates. Results suggest that prokaryotes are functionally redundant in dark biofilms but functionally plastic in light biofilms. The more complex and self‐serving light‐grown biofilm determines a more buffered response to temperature than dark‐grown biofilms. Despite the moderate increase in temperature of only 2°C, warming conditions drive significant changes in freshwater biofilms, which responded by finely tuning a complex network of interactions among microbial populations within the biofilm matrix.
The functional and taxonomic richness of wastewater treatment plant microbial communities are associated with each other and with ambient nitrogen and carbon availability
Authors: Johnson David R. , Lee Tae Kwon , Park Joonhong , Fenner Kathrin , Helbling Damian E.
Published: February 2014

The number of functional traits of a wastewater treatment plant (WWTP) microbial community (i.e. functional richness) is thought to be an important determinant of its overall functional performance, but the ecological factors that determine functional richness remain unclear. The number of taxa within a community (i.e. taxonomic richness) is one ecological factor that might be important. Communities that contain more taxa are more likely to have more functional traits, and a positive association is therefore expected between functional and taxonomic richness. Empirical tests for this positive association among WWTP communities, however, are lacking. We address this knowledge gap by measuring the functional and taxonomic richness of 10 independent WWTP communities. We demonstrate that functional and taxonomic richness are positively associated with each other. We further demonstrate that functional and taxonomic richness are negatively associated with the effluent NH4‐N and BOD5 concentrations. This led us to hypothesize that correlated variation in functional and taxonomic richness is likely related to variation in ambient nitrogen and carbon availability. We finally demonstrate that this hypothesis is consistent with the functional and taxonomic attributes of the WWTP communities. Together, our results improve our basic understanding of the ecology and functioning of WWTP communities.
Citations of Most Often Cited Economists: Do Scholarly Books Matter More than Quality Journals?
Authors: Jin Jang C. , Choi E. Kwan
Published: February 2014

This paper empirically investigates the determinants of citations based on the publication of the top 100 most often cited economists. The effects of publication age and author fame on subsequent citations are found to be positive and significant. Citations are also significantly affected by popular subfields in economics. However, journal quality measures, such as impact factors, download statistics and top‐4 elite journals, have insignificant effects on citations. In contrast, the citation effect of scholarly books is positive and significant, and its impact is even greater than those of journal quality measures.
Risk factors for miscarriage from a prevention perspective: a nationwide follow‐up study
Authors: Feodor Nilsson S , Andersen PK , Strandberg‐Larsen K , Nybo Andersen A‐M
Published: February 2014

Objective

To identify modifiable risk factors for miscarriage and to estimate the preventable proportion of miscarriages that could be attributed to these.

Design

Nationwide observational follow‐up study.

Setting

Denmark.

Population

Ninety‐one thousand four hundred and twenty seven pregnancies included in the Danish National Birth Cohort between 1996 and 2002.

Methods

Information on potentially modifiable risk factors before and during pregnancy was collected by means of computer‐assisted telephone interviews and linkage with Danish registers, ensuring almost complete follow‐up of pregnancy outcome. Modifiable risk factors for miscarriage were identified by multiple Cox regression analysis, which provided the background for our estimations of population attributable fractions. In all, 88 373 pregnancies had full information on all covariates and were included in this analysis.

Main outcome measures

Miscarriage before 22 completed weeks of gestation.

Results

The potentially modifiable pre‐pregnant risk factors associated with increased miscarriage risk were: age of 30 years or more at conception, underweight, and obesity. During pregnancy the modifiable risk factors were: alcohol consumption, lifting of >20 kg daily, and night work. We estimated that 25.2% of the miscarriages might be prevented by reduction of all these risk factors to low risk levels. Modification of risk factors acting before and during pregnancy could lead to prevention of 14.7 and 12.5%, respectively, of the miscarriages. Maternal age at conception and alcohol consumption were the most important risk factors.

Conclusions

Miscarriage risk is increased by multiple potentially modifiable risk factors and a considerable proportion of miscarriages may be preventable.
Recent advances in Takayasu arteritis
Authors: Terao Chikashi , Yoshifuji Hajime , Mimori Tsuneyo
Published: February 2014

Takayasu arteritis (TAK) is a relatively rare systemic vasculitis mainly affecting the aorta and its large branches. While patients with TAK are more frequently observed in Asian countries, we can find patients with TAK all over the world. This limited number of patients has made it difficult to collect large numbers of patients and perform detailed studies. However, recent progresses have led to the identification of susceptibility genes and novel susceptibility human leukocyte antigen (HLA) alleles as well as accumulation of clues for the pathophysiology of TAK. IL12B was shown to be a susceptibility gene beyond ethnicity. MLX and FCGR2A/3A were shown to be associated with TAK in Japanese and Turkish/American populations, respectively. HLA‐B*52:01 and *67:01 are susceptibility alleles to TAK, and the 171st and 67th amino acid residues of HLA‐B protein are suggested important for TAK susceptibility. HLA‐DQB1/DRB1 is recently reported as an independent susceptibility locus. Although there are no standardized serum markers or composite measures for disease activity of TAK, Japanese and Italian groups showed pentraxin 3 as a novel biomarker for detecting and monitoring patients with TAK. Recently, an Indian group proposed a novel scoring system called ITAS to evaluate disease activity of TAK. Standardization of assessing disease activity would lead to clinical studies with high quality. Several groups reported results of treatment for refractory TAK with biological agents targeting tumor necrosis factor or interleukin‐6R. The recent accumulation of research data should improve understanding of the basic pathophysiology of TAK and lead to better management of patients with TAK.
Esophageal cancer incidence and mortality in China, 2010
Authors: Chen Wanqing , Zheng Rongshou , Zhang Siwei , Zeng Hongmei , Fan Yaguang , Qiao Youlin , Zhou Qinghua
Published: February 2014

Background

The National Central Cancer Registry of China (NCCR) is responsible for cancer surveillance. Local cancer registries in each province submit data for annual publication.. The incidence and mortality of esophageal cancer in China in 2010 by age, gender, and area is reported in this article.

Methods

There were data from 145 out of 219 qualified cancer registries. Esophageal cancer cases and deaths (ICD 10 code as C15) were stratified by location, gender, age, and cancer site. The 2000 Chinese census and Segi's population were used for age‐standardized incidence/mortality rates. The rank in all cancer types and cumulative rate were also calculated.

Results

It was estimated that 287 632 new cases were diagnosed and 208 473 patients died from esophageal cancer in 2010 in China. Esophageal cancer incidence ranked fifth of all cancer types with a rate of 21.88/100 000. Age‐standardized rates by Chinese population (CASR) and World population (WASR) for incidence and mortality were 16.71/100 000 and 16.97/100 000, respectively. The mortality of esophageal cancer ranked fourth in all cancer types with a rate of 15.85/100 000. The CASR and WASR for mortality were 11.95/100 000 and 12.02/100 000, respectively. For both incidence and mortality, the rates of esophageal cancer were much higher in men than that in women, in rural areas than in urban areas, and peaked at age 80–84.

Conclusions

Esophageal cancer is still a major cancer type in rural areas of China. Effective prevention and control should be emphasized, including health education, chemoprevention, and early detection in high‐risk groups.
Targeting virulence not viability in the search for future antibacterials
Authors: Heras Begoña , Scanlon Martin J. , Martin Jennifer L.
Published: February 2014

New antibacterials need new approaches to overcome the problem of rapid antibiotic resistance. Here we review the development of potential new antibacterial drugs that do not kill bacteria or inhibit their growth, but combat disease instead by targeting bacterial virulence.
Oxidative stress, redox signalling and endothelial dysfunction in ageing‐related neurodegenerative diseases: a role of NADPH oxidase 2
Authors: Cahill‐Smith Sarah , Li Jian‐Mei
Published: February 2014

Chronic oxidative stress and oxidative damage of the cerebral microvasculature and brain cells has become one of the most convincing theories in neurodegenerative pathology. Controlled oxidative metabolism and redox signalling in the central nervous system are crucial for maintaining brain function; however, excessive production of reactive oxygen species and enhanced redox signalling damage neurons. While several enzymes and metabolic processes can generate intracellular reactive oxygen species in the brain, recently an O2−‐generating enzyme, NADPH oxidase 2 (Nox2), has emerged as a major source of oxidative stress in ageing‐related vascular endothelial dysfunction and neurodegenerative diseases. The currently available inhibitors of Nox2 are not specific, and general antioxidant therapy is not effective in the clinic; therefore, insights into the mechanism of Nox2 activation and its signalling pathways are needed for the discovery of novel drug targets to prevent or treat these neurodegenerative diseases. This review summarizes the recent developments in understanding the mechanisms of Nox2 activation and redox‐sensitive signalling pathways and biomarkers involved in the pathophysiology of the most common neurodegenerative diseases, such as ageing‐related mild cognitive impairment, Alzheimer's disease and Parkinson's disease.
Transitional Paternalism: How Shared Normative Powers Give Rise to the Asymmetry of Adolescent Consent and Refusal
Authors: Manson Neil C.
Published: February 2014

In many jurisdictions, adolescents acquire the right to consent to treatment; but in some cases their refusals – e.g. of life‐saving treatment – may not be respected. This asymmetry of adolescent consent and refusal seems puzzling, even incoherent. The aim here is to offer an original explanation, and a justification, of this asymmetry. Rather than trying to explain the asymmetry in terms of a variable standard of competence – where the adolescent is competent to consent to, but not refuse, certain interventions – the account offered here focuses more closely on the normative power to render actions permissible. Where normative powers are shared they can readily give rise to an asymmetry between consent and refusal. We then turn to why it is justifiable that normative powers be shared in adolescence. Transitional paternalism holds that the acquisition of normative powers by competent adolescents should not be an instant one, achieved in a single step, but that there should be a transitional period where paternalistic protection is rolled back, but not entirely withdrawn until a later date. Transitional paternalism could be implemented without generating the asymmetry between consent and refusal but, it is argued, the asymmetric version of transitional paternalism is to be preferred insofar as it offers a greater respect for the adolescent's decisions than the symmetrical alternative.