bluuebunny/crossref_metadata_2025 huggingface dataset:
Drift Diffusion Modelling of Charge Transport in Photovoltaic Devices
Authors: Richardson Giles , Walker Alison
Published: August 2016

Much thin film photovoltaic (PV) device research is based on a ‘shake and bake’ approach, uninformed by an understanding of the underlying mechanisms. These devices consist of several layers of different materials so that the number of potential materials combinations is enormous. Atomistic models do not work on the length scales needed to study charge transport so device models are essential. The drift diffusion (DD) method is appropriate for charge transport in layered devices. This chapter describes the concepts underpinning DD simulations, provides a ‘how to’ guide for 1-dimensional DD simulation and shows how rescaling the variables leads to considerable insight into the physics of the problem. Finding an equivalent circuit for an organic PV device is given as an example. Since DD models of organic PV devices are reviewed in Chapter 13, our main example shows how a more sophisticated approach, employing a spectral method that predicts coupled ion–electron conduction in perovskite devices, allows us to understand the effect of mobile ions on the operational mechanism of the device.
Charge injection into nanostructured TiO2 electrodes from the photogenerated reduced form of a new Ru(ii) polypyridine compound: the “anti-biomimetic” mechanism at work
Authors: Ronconi Federico , Santoni Marie-Pierre , Nastasi Francesco , Bruno Giuseppe , Argazzi Roberto , Berardi Serena , Caramori Stefano , Bignozzi Carlo A. , Campagna Sebastiano
Published: August 2016

Two charge injection mechanisms are active in a new dye-TiO2 assembly, varying the sacrificial donor.
Concentration dynamics of coarse and fine particulate matter at and around signalised traffic intersections
Authors: Kumar Prashant , Goel Anju
Published: August 2016

The understanding of rapidly evolving concentrations of particulate matter (PMC) at signalised traffic intersections (TIs) is limited, but it is important for accurate exposure assessment.
Scaling and automation of a high-throughput single-cell-derived tumor sphere assay chip
Authors: Cheng Yu-Heng , Chen Yu-Chih , Brien Riley , Yoon Euisik
Published: August 2016

A high-throughput single cell analysis microfluidic chip was developed for single-cell derived sphere assays with automatic cell and sphere image analysis.
Panels of chemically-modified heparin polysaccharides and natural heparan sulfate saccharides both exhibit differences in binding to Slit and Robo, as well as variation between protein binding and cellular activity
Authors: Ahmed Yassir A. , Yates Edwin A. , Moss Diana J. , Loeven Markus A. , Hussain Sadaf-Ahmahni , Hohenester Erhard , Turnbull Jeremy E. , Powell Andrew K.
Published: August 2016

Panels of heparin/heparan sulfate carbohydrates differ in their interactions and bioactivity with Slit and Robo.
Slipped-cofacial J-type phthalocyanine dimers as potential non-linear absorbers for optical limiting applications
Authors: Tolbin Alexander Yu. , Dzuban Alexander V. , Shulishov Evgeny V. , Tomilova Larisa G. , Zefirov Nikolay S.
Published: August 2016

Phthalocyanine J-type dimers show unusual spectral properties and self-assembly in the solid phase. The optical power limiting effect was theoretically investigated.
Nitrogen-doped porous carbon/graphene nanosheets derived from two-dimensional conjugated microporous polymer sandwiches with promising capacitive performance
Authors: Yuan Kai , Hu Ting , Xu Yazhou , Graf Robert , Shi Lei , Forster Michael , Pichler Thomas , Riedl Thomas , Chen Yiwang , Scherf Ullrich
Published: August 2016

Hierarchical, N-doped carbon nanosheets with very promising capacitive performance are prepared using a straightforward procedure.
Polyhedral oligomeric silsesquioxane-based hybrid materials and their applications
Authors: Zhou Hui , Ye Qun , Xu Jianwei
Published: August 2016

POSS are nano-sized stable 3-dimensional architectures which consist of alternate Si–O bonds to form cage structures with Si atoms as vertices.
The effect of needle tip displacement in co-axial electrohydrodynamic processing
Authors: Sofokleous Panagiotis , Lau Wai K. , Edirisinghe Mohan , Stride Eleanor
Published: August 2016

Co-axial electrospraying and electrospinning are versatile electrohydrodynamic (EHD) techniques that can be used to encapsulate a variety of materials in the form of polymeric particles and fibresviaa one step process.
A novel self-terminated Prins strategy for the synthesis of tetrahydropyran-4-one derivatives and their behaviour in Fisher indole synthesis
Authors: Reddy B. V. Subba , Anjum S. Rehana , Sridhar B.
Published: August 2016

A novel self-terminated Prins strategy has been developed for the synthesis of 2-substituted tetrahydropyran-4-one derivatives through a condensation of 3-(phenylthio)but-3-en-1-ol with carbonyl compounds in the presence of 5 mol% of Sc(OTf)3 under mild conditions.
Attaching folic acid on hydroxyapatite nanorod surfaces: an investigation of the HA–FA interaction
Authors: Cipreste Marcelo Fernandes , Gonzalez Ismael , Maria da Mata Martins Thaís , Goes Alfredo Miranda , Augusto de Almeida Macedo Waldemar , Barros de Sousa Edésia Martins
Published: August 2016

The functionalization strategy of HA with folate was tested. A systematic study of the structure and the chemical interaction were performed. The biocompatibility was also tested. HA–FA is a candidate to act as drug delivery or radioisotope carriers.
Functionalization of α-zirconium phosphate by polyphosphazene and its effect on the flame retardance of an intumescent flame retardant polypropylene system
Authors: Xu Lingfeng , Lei Caihong , Xu Ruijie , Zhang Xiaoqing , Zhang Feng
Published: August 2016

α-ZrP was combined with polyphosphazene and formed a core–shell structure, which has a significant synergistic flame retardant performance in polypropylene.
An inquiry-based approach of traditional ‘step-by-step’ experiments
Authors: Szalay L. , Tóth Z.
Published: August 2016

This is the start of a road map for the effective introduction of inquiry-based learning in chemistry. Advantages of inquiry-based approaches to the development of scientific literacy are widely discussed in the literature. However, unless chemistry educators take account of teachers' reservations and identified disadvantages such approaches will never have the place they deserve in the everyday teaching of chemistry. If circumstances do not allow for complicated and open-ended inquiry tasks, simpler and more structured inquiry-based tasks may be used. As a first step, teachers could be asked to modify and adapt established ‘step-by-step’ instructions to practical activities which require some stages to be designed by the students. If this happens only a few times in a school year the question arises about its effectiveness to develop experimental design skills and to reinforce knowledge and ideas taught in chemistry lessons. The present study describes the results of an empirical research project aimed to finding the answer. Modification of step-by-step practical activities as described requires limited time and effort, yet the results suggest that many students benefit from this approach.
A versatile and efficient method to fabricate durable superhydrophobic surfaces on wood, lignocellulosic fiber, glass, and metal substrates
Authors: Wu Yiqiang , Jia Shanshan , Qing Yan , Luo Sha , Liu Ming
Published: August 2016

A versatile and highly efficient method was proposed to fabricate durable, superhydrophobic surfaces on various substrates, including wood, lignocellulosic fibers, cotton textiles, sponge, glass, and metals.
Efficient frequency controllers for autonomous two‐area hybrid microgrid system using social‐spider optimiser
Authors: El‐Fergany Attia A. , El‐Hameed Mohammed A.
Published: August 2016

In this study, an efficient load frequency controller (LFC) for standalone two‐area hybrid microgrid system (HμGS) is addressed. Social‐spider optimiser (SSO) is applied to fine tune the proposed proportional–integral–derivative (PID) controllers by generating their optimal settings. The integral time multiplied summation of absolute deviations and the gains of PID controllers define the fitness function and control variables, respectively. The performance of the proposed SSO‐based method is demonstrated on an isolated HμGS complete with variety of energy storage systems under number of scenarios. The scenarios include load fluctuations, variations in wind speed, and sun irradiance employing real site measurements. In this study, photovoltaic generating arrays and wind turbine generators are not participating in system frequency regulations due the proposal of their maximum power tracking operation strategy. The signatures of time‐domain dynamic responses and cropped numerical results ascertain that the proposed SSO‐based LFC scheme is promising in diminuting the signal deviations and in short time. Further validations for cropped results produced by SSO are made compared with powerful optimisation tool such as genetic algorithm which signify the tuned PID gains.
Explicit 3D finite‐element model of continuous nanofibre networks
Authors: Liu Yong , Dzenis Yuris
Published: August 2016

An explicit three‐dimensional (3D) finite‐element model for dilute nanofibre networks is presented. The model takes into account 3D structure of networks by mimicking nanomanufacturing process. Realistic elasto‐plastic behaviour of individual nanofibres with failure and frictional interfibre contacts are incorporated. The model is capable of predicting through failure mechanical behaviour of nanofibre networks with large fibre reorientation and fibre breaks. Comparison of simulated force–strain behaviour with experimental data showed that predicted and experimental curves exhibited similar shapes consisting of an elastic stage, a strain‐hardening stage, and a softening stage, with abrupt drops coincident with fibre breaks. The numerically predicted maximum tensile force and total failure strain were of the same magnitude as experimental results. The developed explicit model can be used to study the effects of fibre diameter and mechanical properties, network density, fibre orientation distribution, and contact conditions on mechanical behaviour of nanofibre networks. Such studies can shed light on the mechanisms of complex nonlinear deformation and failure of networks and can be used for networks design and optimisation for applications.
Effect of annealing temperatures on the turn‐on voltage of organic Schottky diode based on DPP(BTFu)2
Authors: Mansour Mahdi , Saidi Mohamed , Saidi‐Amroun Nadia
Published: August 2016

The electrical properties of diketopyrrolopyrrole ethyl‐hexylated (DPP(TBFu)2) thin film sandwich structure of the ITO/DPP(TBFu)2/Al configuration for different annealing temperatures ranging from 40 to 130°C is investigated. The current–voltage characteristics showed an excellent rectifying behaviour of the device, and from which the diode parameters were extracted. It is found that all parameters remain constant upon annealing temperatures, with the exception of the turn‐on voltage. An increase of the turn‐on voltage from an initial value of 1.6–2.08 V is noticed starting from 70 to 100°C, respectively. This fact is attributed to the effect of residual solvent induced defect states that may act as free carriers. Defect states density for the non‐annealed and annealed device at 130°C derived from capacitance–voltage measurements is found to correlate well with the turn‐on voltage. It is found that annealing the device at 130°C results in a smaller concentration of defect states. In addition, it is also found that the annealing process produces the flat band voltage drop, which has a direct impact on the turn‐on voltage.
Engineering multistate DNA molecules: a tunable thermal band‐pass filter
Authors: Rose John A. , Komiya Ken , Kobayashi Satoshi
Published: August 2016

Engineering of biopolymer ‘partner folds’ that exist in competitive equilibrium with the native state to produce exotic behaviours remains a relatively unexplored area of molecular engineering. Previously, a temperature‐sensitive DNA nanodevice that operates by harnessing such a partner fold to implement a thermal band‐pass filter was proposed, modelled, and experimentally validated. Due to its peculiar hill‐shaped efficiency profile, which differs markedly from the sigmoidal melting curves of simple DNA hairpins, this device could be used to implement temperature‐specific control of other molecular machines, and thus represents a promising biotechnological advance. However, no effort was made to examine the detailed dependencies of the peak temperature T†, width ΔT50, and maximum efficiency εmax on the stabilities of device components. In this work, closed‐form expressions for T† and ln εmax are derived and validated. The functional behaviours of these expressions are then examined and harnessed to construct an efficient algorithm for producing designs with target T† and ΔT50 values and optimised εmax, thereby establishing the feasibility of algorithmic device design. Method effectiveness is validated via production of a target filter, with detailed simulations of device behaviour. Finally, a discussion is presented regarding model effectiveness, extension, and scope.
Note: A method for correction of finite pulse time effects in flash diffusivity measurements of thin films
Authors: Tao Ye , Yang Liping , Zhong Qiu , Xu Zijun , Luo Caiyun
Published: August 2016

A data correction method that can reduce finite pulse time effects in the flash method is presented in this article. Based on the physical model of the classical flash method, the present method uses the cutoff time moment of laser heating as zero point. This article investigated the case of constant heat flux heating by using the theoretical method and obtained a new calculation formula. The formula was tested in the case where half temperature rise time is less than the pulse time (i.e., τ0/t0.5 > 1), and the result was satisfactory. Theoretically, this method can correct the effect of any finite pulse time and significantly expand the scope of application of the flash method.
The energy crisis in Pakistan: A possible solution via biomass-based waste
Authors: Javed Muhammad Sufyan , Raza Rizwan , Hassan Irtaza , Saeed Rehan , Shaheen Nusrat , Iqbal Javed , Shaukat Saleem F.
Published: August 2016

Developing countries like Pakistan need a continuous supply of clean and cheap energy. It is a very common fear in today's world that the fossil fuels will be depleted soon and the cost of energy is increasing day-by-day. Renewable energy sources and technologies have the potential to provide solutions to long-standing energy problems faced by developing countries. Currently, Pakistan is experiencing a critical energy crisis and renewable energy resources can be the best alternatives for quickly terminating the need for fossil fuels. The renewable energy sources such as solar energy, wind energy, and biomass energy combined with fuel cell technology can be used to overcome the energy shortage in Pakistan. Biomass is a promising renewable energy source and is gaining more interest because it produces a similar type of fuel like crude oil and natural gas. Energy from biomass only depends upon the availability of raw materials; therefore, biomass can play an important role to fulfill the energy requirements of the modern age. The use of energy has increased greatly since the last century and almost all human activities have become more dependent on energy. Biomass, being a potential and indigenous candidate, could be a good solution to meet the energy needs of Pakistan. In this review paper, the detailed current energy requirements and solutions from available energy resources and the scope, potential, and implementation of biomass conversion to energy in Pakistan are explored with a special focus on the major province of Punjab and the advantages of biomass for energy purposes.
A nonlinear flow-transition criterion for the onset of slugging in horizontal channels and pipes
Authors: Campbell Bryce K. , Liu Yuming
Published: August 2016

In this work, the interfacial instability and transition of a two-fluid flow from a stratified state to large amplitude waves or slugs is considered. By combining an asymptotic approximation of the linear Orr-Sommerfeld analysis with nonlinear resonant wave interaction theory, a novel nonlinear slug-transition criterion is derived. This criterion corresponds to a bounding condition on the upper fluid’s velocity in order to limit the amount of energy (provided by the linear instability) which is transferred to long waves through resonant wave interactions. It is proposed that such a condition can predict the formation of large-amplitude long waves and/or slugs. Quantitative comparisons of the onset of slugging are made between the prediction by the nonlinear transition criterion and the experimental measurements carried out in a horizontal square channel. Good agreement is observed. An additional heuristic model is developed which generalizes the transition criterion to flow through horizontal pipes. Comparisons are made for flows through different pipe diameters and over a wide range of fluid properties. Good agreement between the present theoretical predictions and the experimental measurements is also observed.
Flow restrictive and shear reducing effect of magnetization relaxation in ferrofluid cavity flow
Authors: Singh Chamkor , Das Arup Kumar , Das Prasanta Kumar
Published: August 2016

In this study, we report the effects of a uniform stationary magnetic field on the flow of ferrofluid (FF) inside a boundary driven cavity. A coupled set of conservation equations for the flow field, the Maxwell’s magnetostatic equations, and the constitutive magnetization equation are solved numerically. The non-dimensional groups primarily influencing the phenomenon are first systematically identified through the normalization of the complete set of equations. We find the magnetization relaxation effects, under the stationary uniform field, to be flow restrictive in nature. The misalignment between the local magnetic field and the magnetization suppresses the vorticity field in the cavity, shifts the primary central vortex, and reduces the average shear stress at the boundaries. As a consequence, it becomes apparent that at a given Reynolds number, the application of uniform magnetic field can reduce the shear drag at the boundaries of the cavity, of course at an expense of reduced flow rate in their vicinity. Our study uniquely reveals that the relaxation time effects are dominant in the regions of ferrofluid flow where the change in the magnitude of the vorticity takes place over a length scale which is much smaller than the characteristic length scale of the flow geometry. Depending on the magnitudes of influencing parameters, the solution exhibits anomalous characteristics, such as creeping and saturating behavior.
Effect of non-ohmic contacts on the light-intensity dependence of the open-circuit voltage in organic solar cells
Authors: Solak S. , Blom P. W. M. , Wetzelaer G. A. H.
Published: August 2016

The effect of contact barriers on the light-intensity dependence of the open-circuit voltage of organic solar cells is investigated in experiments and simulations. Reduced light-intensity dependence is found when the open-circuit voltage surpasses the built-in voltage, leading to a slope of kT/2q for a device with one non-ohmic contact and a slope of zero for a device with two non-ohmic contacts. The reduced light-intensity dependence of the open-circuit voltage is not caused by entering a contact-recombination-limited regime but by the absence of band bending in the vicinity of a non-ohmic contact.
Correcting lateral chromatic aberrations in non-monochromatic X-ray microscopy
Authors: Falch Ken Vidar , Detlefs Carsten , Di Michiel Marco , Snigireva Irina , Snigirev Anatoly , Mathiesen Ragnvald H.
Published: August 2016

Lateral chromatic aberration in microscopy based on refractive optics may be reduced significantly by adjustments to the illumination scheme. By taking advantage of a broadened bandwidth illumination, the proposed scheme could open for x-ray microscopy with spatial resolution in the range 150–200 nm at millisecond frame rates. The scheme is readily implemented and is achievable using only standard refractive x-ray lenses, which has the advantage of high efficiency. It also maximizes the transmission and removes the spatial filtering effects associated with absorption in x-ray lenses.
Defects, stoichiometry, and electronic transport in SrTiO3-δ epilayers: A high pressure oxygen sputter deposition study
Authors: Ambwani P. , Xu P. , Haugstad G. , Jeong J. S. , Deng R. , Mkhoyan K. A. , Jalan B. , Leighton C.
Published: August 2016

SrTiO3 is not only of enduring interest due to its unique dielectric, structural, and lattice dynamical properties, but is also the archetypal perovskite oxide semiconductor and a foundational material in oxide heterostructures and electronics. This has naturally focused attention on growth, stoichiometry, and defects in SrTiO3, one exciting recent development being such precisely stoichiometric defect-managed thin films that electron mobilities have finally exceeded bulk crystals. This has been achieved only by molecular beam epitaxy, however (and to a somewhat lesser extent pulsed laser deposition (PLD)), and numerous open questions remain. Here, we present a study of the stoichiometry, defects, and structure in SrTiO3 synthesized by a different method, high pressure oxygen sputtering, relating the results to electronic transport. We find that this form of sputter deposition is also capable of homoepitaxy of precisely stoichiometric SrTiO3, but only provided that substrate and target preparation, temperature, pressure, and deposition rate are carefully controlled. Even under these conditions, oxygen-vacancy-doped heteroepitaxial SrTiO3 films are found to have carrier density, mobility, and conductivity significantly lower than bulk. While surface depletion plays a role, it is argued from particle-induced X-ray emission (PIXE) measurements of trace impurities in commercial sputtering targets that this is also due to deep acceptors such as Fe at 100's of parts-per-million levels. Comparisons of PIXE from SrTiO3 crystals and polycrystalline targets are shown to be of general interest, with clear implications for sputter and PLD deposition of this important material.
Uniform second Li ion intercalation in solid state ϵ-LiVOPO4
Authors: Wangoh Linda W. , Sallis Shawn , Wiaderek Kamila M. , Lin Yuh-Chieh , Wen Bohua , Quackenbush Nicholas F. , Chernova Natasha A. , Guo Jinghua , Ma Lu , Wu Tianpin , Lee Tien-Lin , Schlueter Christoph , Ong Shyue Ping , Chapman Karena W. , Whittingham M. Stanley , Piper Louis F. J.
Published: August 2016

Full, reversible intercalation of two Li+ has not yet been achieved in promising VOPO4 electrodes. A pronounced Li+ gradient has been reported in the low voltage window (i.e., second lithium reaction) that is thought to originate from disrupted kinetics in the high voltage regime (i.e., first lithium reaction). Here, we employ a combination of hard and soft x–ray photoelectron and absorption spectroscopy techniques to depth profile solid state synthesized LiVOPO4 cycled within the low voltage window only. Analysis of the vanadium environment revealed no evidence of a Li+ gradient, which combined with almost full theoretical capacity confirms that disrupted kinetics in the high voltage window are responsible for hindering full two lithium insertion. Furthermore, we argue that the uniform Li+ intercalation is a prerequisite for the formation of intermediate phases Li1.50VOPO4 and Li1.75VOPO4. The evolution from LiVOPO4 to Li2VOPO4 via the intermediate phases is confirmed by direct comparison between O K–edge absorption spectroscopy and density functional theory.
Observation of indium ion migration-induced resistive switching in Al/Mg0.5Ca0.5TiO3/ITO
Authors: Lin Zong-Han , Wang Yeong-Her
Published: August 2016

Understanding switching mechanisms is very important for resistive random access memory (RRAM) applications. This letter reports an investigation of Al/Mg0.5Ca0.5TiO3 (MCTO)/ITO RRAM, which exhibits bipolar resistive switching behavior. The filaments that connect Al electrodes with indium tin oxide electrodes across the MCTO layer at a low-resistance state are identified. The filaments composed of In2O3 crystals are observed through energy-dispersive X-ray spectroscopy, high-resolution transmission electron microscopy, nanobeam diffraction, and comparisons of Joint Committee on Powder Diffraction Standards (JCPDS) cards. Finally, a switching mechanism resulting from an electrical field induced by In3+ ion migration is proposed. In3+ ion migration forms/ruptures the conductive filaments and sets/resets the RRAM device.
Robust ferromagnetism of single crystalline CoxZn1−xO (0.3 ≤ x ≤ 0.45) epitaxial films with high Co concentration
Authors: Cao Qiang , Zhu Dapeng , Fu Maoxiang , Cai Li , Yang Ping , Li Shuang , Zhu Yinlian , Ma Xiuliang , Liu Guolei , Chen Yanxue , Yan Shishen , Mei Liangmo , Wang Xiaolin
Published: August 2016

In contrast to conventional dilute magnetic semiconductors with concentrations of magnetic ions of just a few percent, here, we report the fabrication of epitaxial CoxZn1−xO single crystalline films with Co concentrations from x = 0.3 up to 0.45 by radio-frequency oxygen-plasma-assisted molecular beam epitaxy. The films retain their single crystalline wurtzite structure without any other crystallographic phase from precipitates, based on reflection high energy electron diffraction, X-ray diffraction, transmission electron microscopy, and Raman scattering. The results of X-ray diffraction, optical transmission spectroscopy, and in-situ X-ray photoelectron spectroscopy confirm the incorporation of Co2+ cations into the wurtzite lattice. The films exhibit robust ferromagnetism and the magneto-optical Kerr effect at room temperature. The saturation magnetization reaches 265 emu/cm3 at x = 0.45, which corresponds to the average magnetic moment of 1.5 μB per Co atom.
Micron-scale phenotyping quantification and three-dimensional microstructure reconstruction of vascular bundles within maize stalks based on micro-CT scanning
Authors: Du Jianjun , Zhang Ying , Guo Xinyu , Ma Liming , Shao Meng , Pan Xiaodi , Zhao Chunjiang
Published: August 2016

Vascular bundles within maize (Zea mays L.) stalks play a key role in the mechanical support of plant architecture as well as in water and nutrient transportation. Convenient and accurate phenotyping of vascular bundles may help phenotypic identification of germplasm resources for breeding. Based on practical sample preparation procedures for maize stalks, we acquired serials of cross-sectional images using a micro-computed tomography (CT) imaging device. An image processing pipeline dedicated to the phenotyping of vascular bundles was also developed to automatically segment and validate vascular bundles from the cross-sectional images of maize stalks, from which phenotypic traits of vascular bundles, i.e. number, area, and spatial distribution, were calculated. More profound quantification of spatial distribution was given as area ratio of vascular bundles, which described the distribution of vascular bundles associated with the centroid of maize stalks. In addition, three-dimensional visualisation was performed to reveal the spatial configuration and distribution of vascular bundles. The proposed method significantly improves computation accuracy for the phenotypic traits of vascular bundles compared with previous methods, and is expected to be useful for illustrating relationships between phenotypic traits of vascular bundles and their function.
Evidence of proteinuria, but no other characteristics of pre-eclampsia, in relaxin-deficient mice
Authors: O'Sullivan Kelly P. , Marshall Sarah A. , Cullen Scott , Saunders Tahnee , Hannan Natalie J. , Senadheera Sevvandi N. , Parry Laura J.
Published: August 2016

Pre-eclampsia (PE) is a leading cause of maternal and fetal death, characterised by an imbalance of placental growth factors and hypertension at >20 weeks gestation. Impaired maternal systemic vascular adaptations and fetal growth restriction are features of both PE and pregnant relaxin-deficient (Rln–/–) mice. The aim of the present study was to investigate whether these phenotypes in Rln–/– mice are associated with abnormal placental growth factor expression, increased soluble fms-like tyrosine kinase-1 (sFlt-1), proteinuria and/or hypertension during pregnancy. In addition, we examined relaxin and relaxin receptor (relaxin/insulin like family peptide receptor 1 (RXFP1)) mRNA expression in placentas of women with PE. There was no significant difference in placental vascular endothelial growth factor A (VegfA) and placenta growth factor (Plgf) gene expression between Rln–/– and wild-type mice. Circulating plasma sFlt-1 concentrations in pregnant mice of both genotypes and ages were increased compared with non-pregnant mice but were lower in younger pregnant Rln–/– mice compared with aged-matched Rln+/+ mice. Aged pregnant Rln–/– mice had higher urinary albumin : creatinine ratios compared with age-matched Rln+/+ mice, indicative of proteinuria. Systolic and diastolic blood pressures did not differ between genotypes. In addition, PE in women was not associated with altered placental mRNA expression of RLN2 or RXFP1 at term. Overall, the data demonstrate that pregnant Rln–/– mice do not have the typical characteristics of PE. However, these mice show evidence of proteinuria, but we suggest that this results from systemic renal vascular dysfunction before pregnancy.
Structure of fully protonated proteins by proton-detected magic-angle spinning NMR
Authors: Andreas Loren B. , Jaudzems Kristaps , Stanek Jan , Lalli Daniela , Bertarello Andrea , Le Marchand Tanguy , Cala-De Paepe Diane , Kotelovica Svetlana , Akopjana Inara , Knott Benno , Wegner Sebastian , Engelke Frank , Lesage Anne , Emsley Lyndon , Tars Kaspars , Herrmann Torsten , Pintacuda Guido
Published: August 2016

Significance

Protein structure determination is key to the detailed description of many biological processes. The critical factor that would allow general application of magic-angle spinning (MAS) solid-state NMR to this end is improvement in sensitivity and resolution for as many nuclear spins as possible. This is achieved here with detection of resolved
1
H resonances in protonated proteins by increasing MAS rates to frequencies of 100 kHz and above. For large proteins and assemblies, ultrafast spinning narrows spectral resonances better than Brownian motion on which solution NMR relies, removing a fundamental barrier to the NMR study of large systems. This is exploited here to determine the de novo structure of a 28-kDa protein dimer in a 2.5-MDa viral capsid assembly.
Oviposition responses of two mosquito species to pool size and predator presence: varying trade-offs between desiccation and predation risks
Authors: Saward-Arav Deborah , Sadeh Asaf , Mangel Marc , Templeton Alan R. , Blaustein Leon
Published: August 2016

Natural selection is predicted to favor females that can detect risks of desiccation and predation when choosing among temporary pools for oviposition. Pool size may serve both as a cue for desiccation risk and as a predictor for future colonization by predators or for the probability of present, undetected predators. Therefore, oviposition responses to pool size are expected to interact with the presence of predators that can be detected. We measured oviposition by two mosquito species, Culiseta longiareolata and Culex laticinctus, in a mesocosm experiment, crossing two pool surface sizes with presence or absence of the hemipteran predator, Notonecta maculata, which is chemically detectable by mosquitoes. Both mosquito species strongly avoided Notonecta pools. Using a mechanistic statistical model, we accounted for the higher encounter rate of females with larger pools, and determined their true oviposition preferences for pool size. C. laticinctus showed a clear preference for larger pools, but C. longiareolata, a species with larvae more vulnerable to predation, showed no significant preference for pool size. This study confirms the importance of risk of predation in explaining oviposition patterns, and suggests a possible inter-specific variation in the trade-off between predation and desiccation risks.
Transient endoreplication down-regulates the kinesin-14 HSET and contributes to genomic instability
Authors: Chen Shengyao , Stout Jane R. , Dharmaiah Sathiya , Yde Sarah , Calvi Brian R. , Walczak Claire E.
Published: August 2016

Polyploid cancer cells exhibit chromosomal instability (CIN), which is associated with tumorigenesis and therapy resistance. The mechanisms that induce polyploidy and how these mechanisms contribute to CIN are not fully understood. Here we evaluate CIN in human cells that become polyploid through an experimentally induced endoreplication cycle. When these induced endoreplicating cells (iECs) returned to mitosis, it resulted in aneuploidy in daughter cells. This aneuploidy resulted from multipolar divisions, chromosome missegregation, and failure in cytokinesis. The iECs went through several rounds of division, ultimately spawning proliferative cells of reduced ploidy. iECs have reduced levels of the kinesin-14 HSET, which likely accounts for the multipolar divisions, and overexpression of HSET reduced spindle multipolarity. However, HSET overexpression had only mild effects on CIN, suggesting that additional defects must contribute to genomic instability in dividing iECs. Overall our results suggest that transient endoreplication cycles generate a diverse population of proliferative aneuploid cells that have the potential to contribute to tumor heterogeneity.
RIC-3 phosphorylation enables dual regulation of excitation and inhibition ofCaenorhabditis elegansmuscle
Authors: Safdie Gracia , Liewald Jana F. , Kagan Sarah , Battat Emil , Gottschalk Alexander , Treinin Millet
Published: August 2016

Brain function depends on a delicate balance between excitation and inhibition. Similarly, Caenorhabditis elegans motor system function depends on a precise balance between excitation and inhibition, as C. elegans muscles receive both inhibitory, GABAergic and excitatory, cholinergic inputs from motor neurons. Here we show that phosphorylation of the ER-resident chaperone of nicotinic acetylcholine receptors, RIC-3, leads to increased muscle excitability. RIC-3 phosphorylation at Ser-164 depends on opposing functions of the phosphatase calcineurin (TAX-6), and of the casein kinase II homologue KIN-10. Effects of calcineurin down-regulation and of phosphorylated RIC-3 on muscle excitability are mediated by GABAAreceptor inhibition. Thus RIC-3 phosphorylation enables effects of this chaperone on GABAAreceptors in addition to nAChRs. This dual effect provides coordinated regulation of excitation and inhibition and enables fine-tuning of the excitation–inhibition balance. Moreover, regulation of inhibitory GABAAsignaling by calcineurin, a calcium- and calmodulin-dependent phosphatase, enables homeostatic balancing of excitation and inhibition.
Microtubule aging probed by microfluidics-assisted tubulin washout
Authors: Duellberg Christian , Cade Nicholas Ian , Surrey Thomas
Published: August 2016

Microtubules switch stochastically between phases of growth and shrinkage. The molecular mechanism responsible for the end of a growth phase, an event called catastrophe, is still not understood. The probability for a catastrophe to occur increases with microtubule age, putting constraints on the possible molecular mechanism of catastrophe induction. Here we used microfluidics-assisted fast tubulin washout experiments to induce microtubule depolymerization in a controlled manner at different times after the start of growth. We found that aging can also be observed in this assay, providing valuable new constraints against which theoretical models of catastrophe induction can be tested. We found that the data can be quantitatively well explained by a simple kinetic threshold model that assumes an age-dependent broadening of the protective cap at the microtubule end as a result of an evolving tapered end structure; this leads to a decrease of the cap density and its stability. This analysis suggests an intuitive picture of the role of morphological changes of the protective cap for the age dependence of microtubule stability.
Age-specific differences in the seasonal spatial distribution of butterfish (Peprilus triacanthus)
Authors: Adams Charles F.
Published: July 2016

The spatial distribution of butterfish (Peprilus triacanthus) in the Northwest Atlantic Ocean was investigated using a suite of spatial indicators based on Northeast Fisheries Science Center spring and fall bottom trawl survey data, 1982–2013. In the spring, ages 2 and 3 were found farther northeast and deeper than age 1 butterfish, while in the fall, age 3 butterfish were found farther northeast and deeper than ages 0 and 1. There was no significant northward movement of butterfish in spring or fall over the course of either time-series. However, there was a significant increase in the area occupied by ages 1–3 in the spring that was correlated with surface temperature. This illustrates that responses to climate change may be manifested as range expansions, rather than poleward movement of the centre of gravity (i.e. bivariate weighted mean location of the population). Two changes were observed over the course of the fall time series, both for ages 1 and 2: increased spatial dispersion; and a decrease in depth. The former result would have been masked, while the latter would have been erroneously generalized to all age classes, if an age-specific analysis had not been done. This study demonstrates the importance of an age-based and seasonal analysis. It is also shown how a spatial distribution analyses can inform stock assessments by providing insights into diverging survey indices and availability to surveys in general. Similarly, spatial distribution analyses can be used to verify the spatial equilibrium assumption for the calculation of biological reference points.
Observing the ocean interior in support of integrated management
Authors: Trenkel Verena M. , Handegard Nils Olav , Weber Thomas C.
Published: July 2016

Active- and passive-acoustic methods are widely used tools for observing, monitoring, and understanding marine ecosystems. From 25 to 28 May 2015, 214 scientists from 31 nations gathered for an ICES symposium on Marine Ecosystem Acoustics (SoME Acoustics) to discuss three major themes related to acoustic observations of marine ecosystems: (i) recent developments in acoustic and platform technologies; (ii) acoustic characterisation of aquatic organisms, ecosystem structure, and ecosystem processes; and (iii) contribution of acoustics to integrated ecosystem assessments and management. The development of, and access to new instruments, such as broad bandwidth systems, enables insightful ecological studies and innovative management approaches. Unresolved ecological questions and the increasing move towards ecosystem based management pose further challenges to scientists and instrument developers. Considering the SoME Acoustics presentations in the context of three previous ICES symposia on fisheries acoustics, topics increasingly emphasize ecosystem studies and management. The continued expansion of work and progress in marine ecosystem acoustics is due to the cross-disciplinary work of fisheries acousticians, engineers, ecologists, modellers, and others. An analysis of the symposium co-authorship network reveals a highly connected acoustic science community collaborating around the globe.
Conceptualizing Consciousness in Consumer Research
Authors: Williams Lawrence E , Poehlman T Andrew
Published: August 2016

An outsized focus on the explanatory value of conscious thought can constrain opportunities to more rigorously examine the influence of less obvious drivers of consumer behavior. This article proposes a more precise, disaggregated, and minimized perspective on consciousness, distinguishing it from other higher-order mental processes (i.e., deliberation, intentionality, control, and effort). A more circumscribed perspective on consciousness, we argue, facilitates attempts to examine the causal impact of low-level, biological, or otherwise unconscious influences, bringing these into the frame of inquiry. Accordingly, we outline how a reduced reliance on consciousness as an explanatory construct deepens inquiry into the processes guiding choice, self-control, and persuasion. Lastly, in a set of recommendations centering on theory, methods, and training, we suggest ways for consumer researchers to evaluate more critically whether the contents of consciousness play a meaningful role in driving behavior.
Long-term complications of definitive chemoradiotherapy for esophageal cancer using the classical method
Authors: Ito Hitoshi , Itasaka Satoshi , Sakanaka Katsuyuki , Araki Norio , Mizowaki Takashi , Hiraoka Masahiro
Published: July 2016

Chemoradiation therapy is widely used to treat both inoperable and operable patients, and is less invasive than surgery. Although the number of long-term survivors who have received chemoradiation therapy is increasing, the long-term toxicity pattern and cumulative incidence of toxicity regarding this modality are poorly understood. Classically, chemoradiation therapy for esophageal cancer consists of an anterior–posterior field and a subsequent oblique boost field. We retrospectively analyzed patients who were treated with definitive chemoradiation therapy for esophageal cancer using this classical method from 1999 to 2008. For the assessment of toxicity, the National Cancer Institute Common Toxicity Criteria Version 3.0 was adopted. A total of 101 patients were analyzed. The median follow-up time was 16 months for all patients and 62 months for the surviving patients. Eleven patients experienced late toxicities of ≥Grade 3. Two patients died of late toxicities. The 3- and 5-year cumulative incidences for the first late cardiopulmonary toxicities of ≥Grade 3 were 17.4% and 20.8%, respectively. Cardiopulmonary effusions were observed within the first 3 years of completion of the initial treatment in seven out of eight patients. Sudden death and cardiac ischemia were observed over a 10-year period. Older age was found to be a risk factor for late toxicity after definitive chemoradiation therapy for esophageal cancer. Substantial toxicities were observed in patients who had received chemoradiation therapy for esophageal cancer using the classical method. To minimize the incidence of late toxicity, more sophisticated radiation techniques may be useful.
Identification and characterization of wheat drought-responsive MYB transcription factors involved in the regulation of cuticle biosynthesis
Authors: Bi Huihui , Luang Sukanya , Li Yuan , Bazanova Natalia , Morran Sarah , Song Zhihong , Perera M. Ann , Hrmova Maria , Borisjuk Nikolai , Lopato Sergiy
Published: August 2016

A plant cuticle forms a hydrophobic layer covering plant organs, and plays an important role in plant development and protection from environmental stresses. We examined epicuticular structure, composition, and a MYB-based regulatory network in two Australian wheat cultivars, RAC875 and Kukri, with contrasting cuticle appearance (glaucousness) and drought tolerance. Metabolomics and microscopic analyses of epicuticular waxes revealed that the content of β-diketones was the major compositional and structural difference between RAC875 and Kukri. The content of β-diketones remained the same while those of alkanes and primary alcohols were increased by drought in both cultivars, suggesting that the interplay of all components rather than a single one defines the difference in drought tolerance between cultivars. Six wheat genes encoding MYB transcription factors (TFs) were cloned; four of them were regulated in flag leaves of both cultivars by rapid dehydration and/or slowly developing cyclic drought. The involvement of selected MYB TFs in the regulation of cuticle biosynthesis was confirmed by a transient expression assay in wheat cell culture, using the promoters of wheat genes encoding cuticle biosynthesis-related enzymes and the SHINE1 (SHN1) TF. Two functional MYB-responsive elements, specifically recognized by TaMYB74 but not by other MYB TFs, were localized in the TdSHN1 promoter. Protein structural determinants underlying the binding specificity of TaMYB74 for functional DNA cis -elements were defined, using 3D protein molecular modelling. A scheme, linking drought-induced expression of the investigated TFs with downstream genes that participate in the synthesis of cuticle components, is proposed.
Optical and radio astrometry of the galaxy associated with FRB 150418
Authors: Bassa C. G. , Beswick R. , Tingay S. J. , Keane E. F. , Bhandari S. , Johnston S. , Totani T. , Tominaga N. , Yasuda N. , Stappers B. W. , Barr E. D. , Kramer M. , Possenti A.
Published: July 2016

A fading radio source, coincident in time and position with the fast radio burst FRB 150418, has been associated with the galaxy WISE J071634.59−190039.2. Subsequent observations of this galaxy have revealed that it contains a persistent, but variable, radio source. We present e-Multi-Element Radio Linked Interferometer Network, Very Long Baseline Array, and Australia Telescope Compact Array radio observations and Subaru optical observations of WISE J071634.59−190039.2 and find that the persistent radio source is unresolved and must be compact (<0.01 kpc), and that its location is consistent with the optical centre of the galaxy. We conclude that it is likely that WISE J071634.59−190039.2 contains a weak radio active galactic nucleus.
When and where did GW150914 form?
Authors: Lamberts A. , Garrison-Kimmel S. , Clausen D. R. , Hopkins P. F.
Published: July 2016

The recent LIGO detection of gravitational waves (GW150914), likely originating from the merger of two ∼ 30M⊙ black holes suggests progenitor stars of low metallicity ([Z/Z⊙] ≲ 0.3), constraining when and where the progenitor of GW150914 may have formed. We combine estimates of galaxy properties (star-forming gas metallicity, star formation rate and merger rate) across cosmic time to predict the low redshift black hole – black hole merger rate as a function of present day host galaxy mass, Mgal, the formation redshift of the progenitor system zf and different progenitor metallicities Zp. For $Z_\mathrm{p}\geqslant 0.1 \rm Z_{{\odot }}$, the signal is dominated by binaries in massive galaxies with zf ≃ 2 while below $Z_\mathrm{p}\leqslant 0.1\rm Z_{{\odot }}$ most mergers come from binaries formed around zf ≃ 0.5 in dwarf galaxies. Additional gravitational wave detections from merging massive black holes will provide constraints on the mass–metallicity relation and massive star formation at high redshifts.
Definitive test of the Rh = ct universe using redshift drift
Authors: Melia Fulvio
Published: August 2016

The redshift drift of objects moving in the Hubble flow has been proposed as a powerful model-independent probe of the underlying cosmology. A measurement of the first- and second-order redshift derivatives appears to be well within the reach of upcoming surveys using as the Extremely Large Telescope high resolution spectrometer (ELT-HIRES) and the Square Kilometer Phase 2 Array (SKA). Here we show that an unambiguous prediction of the Rh = ct cosmology is zero drift at all redshifts, contrasting sharply with all other models in which the expansion rate is variable. For example, multiyear monitoring of sources at redshift z = 5 with the ELT-HIRES is expected to show a velocity shift Δv = −15 cm s−1 yr−1 due to the redshift drift in Planck ΛCDM, while Δv = 0 cm s−1 yr−1 in Rh = ct. With an anticipated ELT-HIRES measurement error of ±5 cm s−1 yr−1 after 5 yr, these upcoming redshift drift measurements might therefore be able to differentiate between Rh = ct and Planck ΛCDM at ∼3σ, assuming that any possible source evolution is well understood. Such a result would provide the strongest evidence yet in favour of the Rh = ct cosmology. With a 20-yr baseline, these observations could favour one of these models over the other at better than 5σ.