bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical study of nonequilibrium plasma assisted detonation initiation in detonation tube
Authors: Zhou Siyin , Wang Fang , Che Xueke , Nie Wansheng
Published: December 2016

Nonequilibrium plasma has shown great merits in ignition and combustion nowadays, which should be especially useful for hypersonic propulsion. A coaxial electrodes configuration was established to investigate the effect of alternating current (AC) dielectric barrier discharge nonequilibrium plasma on the detonation initiation process in a hydrogen-oxygen mixture. A discharge simulation-combustion simulation loosely coupled method was used to simulate plasma assisted detonation initiation. First, the dielectric barrier discharge in the hydrogen-oxygen mixture driven by an AC voltage was simulated, which takes 17 kinds of particles (including positively charged particles, negatively charged particles, and neutral particles) and 47 reactions into account. The temporal and spatial characteristics of the discharge products were obtained. Then, the discharge products were incorporated into the combustion model of a detonation combustor as the initial conditions for the later detonation initiation simulation. Results showed that the number density distributions of plasma species are different in space and time, and develop highly nonuniformly from high voltage electrode to grounded electrode at certain times. All the active species reach their highest concentration at approximately 0.6T (T denotes a discharge cycle). Compared with the no plasma case, the differences of flowfield shape mainly appear in the early stage of the deflagration to detonation transition process. None of the sub-processes (including the very slow combustion, deflagration, over-driven detonation, detonation decay, and propagation of a self-sustained stable detonation wave) have been removed by the plasma. After the formation of a C-J detonation wave, the whole flowfield remains unchanged. With the help of plasma, the deflagration to detonation transition (DDT) time and distance are reduced by about 11.6% and 12.9%, respectively, which should be attributed to the active particles effect of nonequilibrium plasma and the local turbulent enhancing effect by the spatial characteristics of discharge. In addition, as the duration of forming a shock wave in the combustor is shortened by approximately 8.1%, it can be inferred that the plasma accelerates the DDT process more significantly before the flow becomes supersonic.
Linear global gyrokinetic simulations of toroidal Alfven eigenmodes in KSTAR plasmas
Authors: Shahzad M. , Rizvi H. , Ryu C. M.
Published: December 2016

Excitation of toroidal Alfven eigenmodes (TAEs) in KSTAR tokamak plasmas has been studied by using the GENE code. Verification and benchmark analysis are performed for Alfven eigenmodes (AEs) excited by the energetic particles (EPs) in comparison with the AEs from the GYGLES code, and excellent agreements are found. In addition, the threshold value of the EP density gradient to destabilize the TAE has been investigated. For the plasma equilibrium of KSTAR discharge (10574), TAEs of n = 2 are found to be excited by coupling of adjoining poloidal harmonics (5, 6), (6, 7), and (7, 8). The dependence of the growth rate and frequency of the TAE on the EP density gradient is examined. It is found that the threshold value of EP density gradient increases with the higher poloidal mode coupling, of which location moves outward in the radial direction. The growth rates of TAEs with higher poloidal mode numbers are smaller than those with lower poloidal mode numbers, indicating that perpendicular wavenumbers play an important role. The efficiency of the EP drive for the TAE decreases for a higher poloidal mode coupling. At a higher EP density gradient, TAEs with higher poloidal harmonics are less unstable due to the decrease in the radial extents of the modes.
Effect of sequence dispersity on morphology of tapered diblock copolymers from molecular dynamics simulations
Authors: Levine William G. , Seo Youngmi , Brown Jonathan R. , Hall Lisa M.
Published: December 2016

Tapered diblock copolymers are similar to typical AB diblock copolymers but have an added transition region between the two blocks which changes gradually in composition from pure A to pure B. This tapered region can be varied from 0% (true diblock) to 100% (gradient copolymer) of the polymer length, and this allows some control over the microphase separated domain spacing and other material properties. We perform molecular dynamics simulations of linearly tapered block copolymers with tapers of various lengths, initialized from fluids density functional theory predictions. To investigate the effect of sequence dispersity, we compare systems composed of identical polymers, whose taper has a fixed sequence that most closely approximates a linear gradient, with sequentially disperse polymers, whose sequences are created statistically to yield the appropriate ensemble average linear gradient. Especially at high segregation strength, we find clear differences in polymer conformations and microstructures between these systems. Importantly, the statistical polymers are able to find more favorable conformations given their sequence, for instance, a statistical polymer with a larger fraction of A than the median will tend towards the A lamellae. The conformations of the statistically different polymers can thus be less stretched, and these systems have higher overall density. Consequently, the lamellae formed by statistical polymers have smaller domain spacing with sharper interfaces.
Field enhancement at silicon surfaces by gold ellipsoids probed by optical second-harmonic generation spectroscopy
Authors: Ulriksen Hans Ulrik , Pedersen Kjeld
Published: December 2016

Optical second-harmonic generation (SHG) spectroscopy has been used to determine the field enhancements from Au nanoparticles on a silicon substrate. Au particles with diameters from 30 to 250 nm have been deposited on a Si substrate passivated by a 1 nm thick surface oxide. The linear optical spectra are dominated by a horizontal plasmon resonance near 1.0 eV, and the experimental spectra are modelled by the island film model in order to extract the linear properties of the metal particles. SHG spectroscopy from this system shows resonances from the metal particles and from the silicon/oxide substrate. By following the evolution of these Si resonances with the size of the Au particles, the field enhancement in the Si surface has been modelled. The effect of the Au particles on SHG at the Si E1 resonance is a combination of charge transfer through the thin oxide that changes the space charge region and an enhancement of the optical field in a thin surface layer of the Si substrate.
A Hamiltonian approach to the cohomogeneity one Ricci soliton equations and explicit examples of non-Kähler solitons
Authors: Betancourt de la Parra Alejandro , Dancer Andrew S. , Wang McKenzie Y.
Published: December 2016

We show how to view the equations for a cohomogeneity one Ricci soliton as a Hamiltonian system with a constraint. We investigate conserved quantities and superpotentials and use this to find some explicit formulae for Ricci solitons not of Kähler type in five dimensions.
A technique for individual atom delivery into a crossed vortex bottle beam trap using a dynamic 1D optical lattice
Authors: Dinardo Brad A. , Anderson Dana Z.
Published: December 2016

We describe a system for loading a single atom from a reservoir into a blue-detuned crossed vortex bottle beam trap using a dynamic 1D optical lattice. The lattice beams are frequency chirped using acousto-optic modulators, which causes the lattice to move along its axial direction and behave like an optical conveyor belt. A stationary lattice is initially loaded with approximately 6000 atoms from a reservoir, and the conveyor belt transports them 1.1 mm from the reservoir to a bottle beam trap, where a single atom is loaded via light-assisted collisions. Photon counting data confirm that an atom can be delivered and loaded into the bottle beam trap 13.1% of the time.
Electron beam evaporation of boron at forevacuum pressures for plasma-assisted deposition of boron-containing coatings
Authors: Yushkov Yu. G. , Tyunkov A. V. , Oks E. M. , Zolotukhin D. B.
Published: December 2016

We describe the use of a plasma-cathode electron source for electron beam evaporation of boron at forevacuum pressures (∼10 Pa) with subsequent deposition of boron-containing coatings on a titanium substrate. We analyze the process of electron beam heating and evaporation of boron, study the mass-to-charge composition of the gas and boron beam-produced plasma, apply such plasma for coating deposition, and investigate the elemental composition of the deposited film and its microhardness.
Polarization switching from plasmonic lattice mode to multipolar localized surface plasmon resonances in arrays of large nanoantennas
Authors: Wing Waylin J. , Sadeghi Seyed M. , Gutha Rithvik R.
Published: December 2016

We experimentally investigate plasmonic lattice modes of gold nanoantenna arrays that occur in asymmetric structures containing a silica substrate and either air or a thin layer of a high-index dielectric. Very distinct polarization switching is observed in the nanoantenna arrays wherein by rotating the incident light polarization by ninety degrees, the array can exhibit either a plasmonic lattice mode or a multipolar localized surface plasmon resonance of varying nature. A large range of nanoantenna lengths are studied, and since the length of the nanoantennas dictates the multipolar localized surface plasmon resonance, we find that the characteristics of the polarization switching are affected accordingly. We also investigate how the thin layer of the high-index dielectric on top of the nanoantenna arrays, in conjunction with varying nanoantenna length, impacts the generation of plasmonic lattice modes and the polarization switching in the arrays. The high-index dielectric is found to assist in the generation and optical coupling of the plasmonic lattice modes. By altering the angle of incidence, the polarization switching can become very large, and the arrays can be made to selectively transmit light of certain wavelengths.
The migration and growth of nuclei in an ideal vortex flow
Authors: Zhang Lingxin , Chen Linya , Shao Xueming
Published: December 2016

Tip vortex cavitation occurs on ship propellers which can cause significant noise compared to the wet flow. In order to predict the inception of tip vortex cavitation, numerous researches have been investigated about the detailed flow field around the tip. According to informed studies, the inception of tip vortex cavitation is affected by many factors. To understand the effect of water quality on cavitation inception, the motion of nuclei in an ideal vortex flow, i.e., the Rankine vortex flow, was investigated. The one-way coupling point-particle tracking model was employed to simulate the trajectory of nuclei. Meanwhile, Rayleigh-Plesset equation was introduced to describe the growth of nuclei. The results show that the nucleus size has a significant effect on nucleus’ trajectory. The capture time of a nucleus is approximately inversely proportional to its radius. The growth of nucleus accelerates its migration in the vortex flow and shortens its capture time, especially for the case of explosive growth.
A mechanical rotator for neutron scattering measurements
Authors: Thaler A. , Northen E. , Aczel A. A. , MacDougall G. J.
Published: December 2016

We have designed and built a mechanical rotation system for use in single crystal neutron scattering experiments at low temperatures. The main motivation for this device is to facilitate the application of magnetic fields transverse to a primary training axis, using only a vertical cryomagnet. Development was done in the context of a triple-axis neutron spectrometer, but the design is such that it can be generalized to a number of different instruments or measurement techniques. Here, we discuss some of the experimental constraints motivating the design, followed by design specifics, preliminary experimental results, and a discussion of potential uses and future extension possibilities.
Demkov-Kunike models with decay
Authors: Kenmoe M. B. , Tchapda A. B. , Fai L. C.
Published: December 2016

Exact analytical solutions to the dissipative time-dependent Schrödinger equation are obtained for a decaying two-state system with decay rates Γ1 and Γ2 for the levels with extremal spin projections. The system is coherently driven with a pulse whose detuning is made up of two parts: a time-dependent part (chirp) of hyperbolic-tangent shape and a static part with real and imaginary terms. This gives us a wide range of possibilities to arbitrarily select the interaction terms. We considered two versions which led to decaying Demkov-Kunike (DK) models; the version in which the Rabi frequency (interaction) is a time-dependent hyperbolic-secant function (called decaying DK1 model) and the case when it is constant in time and never turns off (decaying DK2 model). Our analytical solutions account for all possible initial moments instead of only t0 = 0 or t0 = − ∞ as for non-decaying models and may be useful for the experiments on level crossings. Two complementary limits of the pulse detuning are considered and explored: the limit of fast (i) and slow rise (ii). In the case (i), the coupling between level positions in the first DK model collapses, while the second DK model reduces to a Rabi model (constant Hamiltonian), in the case (ii), both DK models reduce to the LZ model. In both cases (i) and (ii), analytical approximated solutions which conveniently approach the exact solutions are derived.
Exactly solvable Hermite, Laguerre, and Jacobi type quantum parametric oscillators
Authors: A. Büyükaşık Şirin , Çayiç Zehra
Published: December 2016

We introduce exactly solvable quantum parametric oscillators, which are generalizations of the quantum problems related with the classical orthogonal polynomials of Hermite, Laguerre, and Jacobi type, introduced in the work of Büyükaşık et al. [J. Math. Phys. 50, 072102 (2009)]. Quantization of these models with specific damping, frequency, and external forces is obtained using the Wei-Norman Lie algebraic approach. This determines the evolution operator exactly in terms of two linearly independent homogeneous solutions and a particular solution of the corresponding classical equation of motion. Then, time-evolution of wave functions and coherent states are found explicitly. Probability densities, expectation values, and uncertainty relations are evaluated and their properties are investigated under the influence of the external terms.
Enhanced phonon scattering by nanovoids in high thermoelectric power factor polysilicon thin films
Authors: Dunham Marc T. , Lorenzi Bruno , Andrews Sean C. , Sood Aditya , Asheghi Mehdi , Narducci Dario , Goodson Kenneth E.
Published: December 2016

The ability to tune the thermal conductivity of semiconductor materials is of interest for thermoelectric applications, in particular, for doped silicon, which can be readily integrated in electronic microstructures and have a high thermoelectric power factor. Here, we examine the impact of nanovoids on the thermal conductivity of highly doped, high-power factor polysilicon thin films using time-domain thermoreflectance. Voids are formed through ion implantation and annealing, evolving from many small (∼4 nm mean diameter) voids after 500 °C anneal to fewer, larger (∼29 nm mean diameter) voids with a constant total volume fraction after staged thermal annealing to 1000 °C. The thermal conductivity is reduced to 65% of the non-implanted reference film conductivity after implantation and 500 °C anneal, increasing with anneal temperature until fully restored after 800 °C anneal. The void size distributions are determined experimentally using small-angle and wide-angle X-ray scattering. While we believe multiple physical mechanisms are at play, we are able to corroborate the positive correlation between measurements of thermal conductivity and void size with Monte Carlo calculations and a scattering probability based on Matthiessen's rule. The data suggest an opportunity for thermal conductivity suppression combined with the high power factor for increased material zT and efficiency of nanostructured polysilicon as a thermoelectric material.
Localized ultrahigh frequency acoustic fields induced micro-vortices for submilliseconds microfluidic mixing
Authors: Cui Weiwei , Zhang Hao , Zhang Hongxiang , Yang Yang , He Meihang , Qu Hemi , Pang Wei , Zhang Daihua , Duan Xuexin
Published: December 2016

We present an acoustic microfluidic mixing approach via acousto-mechanically induced micro-vortices sustained by localized ultrahigh frequency (UHF) acoustic fields. A micro-fabricated solid-mounted thin-film piezoelectric resonator (SMR) with a frequency of 1.54 GHz has been integrated into microfluidic systems. Experimental and simulation results show that UHF-SMR triggers strong acoustic field gradients to produce efficient and highly localized acoustic streaming vortices, providing a powerful source for microfluidic mixing. Homogeneous mixing with 87% mixing efficiency at a Peclet number of 35520 within 1 ms has been achieved. The proposed strategy shows a great potential for microfluidic mixing and enhanced molecule transportation in minimized analytical systems.
Analytical solution and optimal design for galloping-based piezoelectric energy harvesters
Authors: Tan T. , Yan Z.
Published: December 2016

The performance of the galloping-based piezoelectric energy harvester is usually investigated numerically. Instead of performing case studies by numerical simulations, analytical solutions of the nonlinear distributed parameter model are derived to capture the intrinsic effects of the physical parameters on the performance of such energy harvesters. The analytical solutions are confirmed with the numerical solutions. Optimal performance of such energy harvesters is therefore revealed theoretically. The electric damping due to the electromechanical coupling is defined. The design at the optimal electrical damping with smaller onset speed to galloping, higher harvested power, and acceptable tip displacement is superior than the design at the maximal electrical damping, as long as the optimal electrical damping can be achieved. Otherwise, the design at the maximal electrical damping should be then adopted. As the wind speed and aerodynamic empirical coefficients increase, the tip displacement and harvested power increase. This study provides a theoretical design and optimization procedure for galloping-based piezoelectric energy harvesters.
Visible wavelength surface-enhanced Raman spectroscopy from In-InP nanopillars for biomolecule detection
Authors: Murdoch B. J. , Portoles J. F. , Tardio S. , Barlow A. J. , Fletcher I. W. , Cumpson P. J.
Published: December 2016

Visible wavelength surface-enhanced Raman spectroscopy (SERS) has been observed from bovine serum albumin (BSA) using In-InP nanopillars synthesised by Ar gas cluster ion beam sputtering of InP wafers. InP provides a high local refractive index for plasmonic In structures, which increases the wavelength of the In surface plasmon resonance. The Raman scattering signal was determined to be up to 285 times higher for BSA deposited onto In-InP nanopillars when compared with Si wafer substrates. These substrates demonstrate the label-free detection of biomolecules by visible wavelength SERS, without the use of noble metal particles.
Four-state non-volatile memory in a multiferroic spin filter tunnel junction
Authors: Ruan Jieji , Li Chen , Yuan Zhoushen , Wang Peng , Li Aidong , Wu Di
Published: December 2016

We report a spin filter type multiferroic tunnel junction with a ferromagnetic/ferroelectric bilayer barrier. Memory functions of a spin filter magnetic tunnel junction and a ferroelectric tunnel junction are combined in this single device, producing four non-volatile resistive states that can be read out in a non-destructive manner. This concept is demonstrated in a LaNiO3/Pr0.8Ca0.2MnO3/BaTiO3/La0.7Sr0.3MnO3 all-oxide tunnel junction. The ferromagnetic insulator Pr0.8Ca0.2MnO3 serves as the spin filter and the ferromagnetic metal La0.7Sr0.3MnO3 is the spin analyzer. The ferroelectric polarization reversal in the BaTiO3 barrier switches the tunneling barrier height to produce a tunneling electroresistance. The ferroelectric switching also modulates the spin polarization and the spin filtering efficiency in Pr0.8Ca0.2MnO3.
Observation of large magnetocaloric effect in equiatomic binary compound ErZn
Authors: Li Lingwei , Yuan Ye , Xu Chi , Qi Yang , Zhou Shengqiang
Published: December 2016

The magnetism, magnetocaloric effect and universal behaviour in rare earth Zinc binary compound of ErZn have been studied. The ErZn compound undergoes a second order paramagnetic (PM) to ferromagnetic (FM) transition at Curie temperature of TC ∼ 20 K. The ErZn compound exhibits a large reversible magnetocaloric effect (MCE) around its own TC. The rescaled magnetic entropy change curves overlap with each other under various magnetic field changes, further confirming the ErZn with the second order phase transition. For the magnetic field change of 0-7 T, the maximum values of the magnetic entropy change (−ΔSMmax), relative cooling power (RCP) and refrigerant capacity (RC) for ErZn are 23.3 J/kg K, 581 J/kg and 437 J/kg, respectively.
Exchange bias effect in CaMn𝟏−𝒙Re𝒙O3
Authors: Markovich V. , Fita I. , Wisniewski A. , Puzniak R. , Martin C. , Jung G. , Gorodetsky G.
Published: December 2016

Exchange bias effect in CaMn1-xRexO3 (x ≤ 0.1) has been investigated. The effect is very small in the samples doped at x = 0.02 and 0.04, but increases monotonously with further increase in Re doping. For x = 0.1, both vertical and horizontal shifts in hysteresis loop of field cooled sample decrease monotonously with increasing temperature and vanish above 70 K, while coercivity disappears only above 90 K upon approaching the Néel temperature. Exchange bias field, coercivity, and remanence asymmetry depend sensitively on temperature and maximal measuring field. Magnetic training effect has been studied for x = 0.06, 0.08, 0.1 samples and analyzed using a spin relaxation model. The observed exchange bias is attributed to the low-temperature phase separation into ferromagnetic clusters and the G-type and/or C-type antiferromagnetic matrix.
Utilization of multiple read heads for TMR prediction and correction in bit-patterned media recording
Authors: Busyatras W. , Warisarn C. , Okamoto Y. , Nakamura Y. , Myint L. M. M. , Supnithi P. , Kovintavewat P.
Published: December 2016

This paper proposes a utilization of multiple read heads to predict and correct a track mis-registration (TMR) in bit-patterned media recording (BPMR) based on the readback signals. We propose to use the signal energy ratio between the upper and lower tracks from multiple read heads to estimate the TMR level. Then, a pair of two-dimensional (2D) target and its corresponding 2D equalizer associated with the estimated TMR will be chosen to correct the TMR in the data detection process. Numerical results show that the proposed system can achieve a very high accuracy of TMR prediction, thus performing better than the conventional system, especially when TMR is severe.
Relative importance of transpiration rate and leaf morphological traits for the regulation of leaf temperature
Authors: Monteiro Madalena Vaz , Blanuša Tijana , Verhoef Anne , Hadley Paul , Cameron Ross W. F.
Published: December 2016

Urban greening solutions such as green roofs help improve residents’ thermal comfort and building insulation. However, not all plants provide the same level of cooling. This is partially due to differences in plant structure and function, including different mechanisms that plants employ to regulate leaf temperature. Ranking of multiple leaf and plant traits involved in the regulation of leaf temperature (and, consequently, plants’ cooling ‘service’) is not well understood. We, therefore, investigated the relative importance of water loss, leaf colour, thickness and extent of pubescence for the regulation of leaf temperature, in the context of species for semi-extensive green roofs. Leaf temperature was measured with an infrared imaging camera in a range of contrasting genotypes within three plant genera (Heuchera, Salvia and Sempervivum). In three glasshouse experiments (each evaluating three or four genotypes of each genus), we varied water availability to the plants and assessed how leaf temperature altered depending on water loss and specific leaf traits. Greatest reductions in leaf temperature were closely associated with higher water loss. Additionally, in non-succulents (Heuchera, Salvia), lighter leaf colour and longer hair length (on pubescent leaves) both contributed to reduced leaf temperature. However, in succulent Sempervivum, colour and pubescence made no significant contribution; leaf thickness and rate of water loss were the key regulating factors. We propose that this can lead to different plant types having significantly different potentials for cooling. We suggest that maintaining transpirational water loss by sustainable irrigation and selecting urban plants with favourable morphological traits are the key to maximising thermal benefits provided by applications such as green roofs.
Phenotyping of plants in competitive but controlled environments: a study of drought response in transgenic wheat
Authors: Kovalchuk Nataliya , Laga Hamid , Cai Jinhai , Kumar Pankaj , Parent Boris , Lu Zhi , Miklavcic Stanley J. , Haefele Stephan M.
Published: December 2016

In recent years, the interest in new technologies for wheat improvement has increased greatly. To screen genetically modified germplasm in conditions more realistic for a field situation we developed a phenotyping platform where transgenic wheat and barley are grown in competition. In this study, we used the platform to (1) test selected promoter and gene combinations for their capacity to increase drought tolerance, (2) test the function and power of our platform to screen the performance of transgenic plants growing in competition, and (3) develop and test an imaging and analysis process as a means of obtaining additional, non-destructive data on plant growth throughout the whole growth cycle instead of relying solely on destructive sampling at the end of the season. The results showed that several transgenic lines under well watered conditions had higher biomass and/or grain weight than the wild-type control but the advantage was significant in one case only. None of the transgenics seemed to show any grain weight advantage under drought stress and only two lines had a substantially but not significantly higher biomass weight than the wild type. However, their evaluation under drought stress was disadvantaged by their delayed flowering date, which increased the drought stress they experienced in comparison to the wild type. Continuous imaging during the season provided additional and non-destructive phenotyping information on the canopy development of mini-plots in our phenotyping platform. A correlation analysis of daily canopy coverage data with harvest metrics showed that the best predictive value from canopy coverage data for harvest metrics was achieved with observations from around heading/flowering to early ripening whereas early season observations had only a limited diagnostic value. The result that the biomass/leaf development in the early growth phase has little correlation with biomass or grain yield data questions imaging approaches concentrating only on the early development stage.
Intrafollicular oestradiol production, expression of the LH receptor (LHR) gene and its isoforms, and early follicular deviation in Bos indicus
Authors: Wohlres-Viana S. , Arashiro E. K. N. , Machado M. A. , Camargo L. S. A. , Siqueira L. G. B. , Palhao M. P. , Viana J. H. M.
Published: December 2016

The aim of the present study was to characterise the roles of intrafollicular oestradiol production and granulosa cell (GC) expression of the LH receptor (LHR) gene and its isoforms during follicular deviation in Bos indicus. Follicular wave emergence was synchronised in heifers from a Bos taurus dairy (Holstein; n = 10) and a B. indicus dairy breed (Gir; n = 10). Follicles were aspirated individually at sizes corresponding to the periods of predeviation, deviation and postdeviation. Intrafollicular oestradiol (IF-E2) and progesterone (IF-P4) concentrations were determined in the follicular fluid (FF) by radioimmunoassay, and relative expression of P450 aromatase (CYP19A1) and LHR forms was evaluated in GC using real-time quantitative–polymerase chain reaction. Despite differences in the size of the dominant follicle at deviation, changes in CYP19A1 expression and IF-E2 concentrations were similar in follicles of the same diameter in both breeds. A peak in total LHR expression occurred after follicular deviation in association with low expression of LHR isoforms. The results suggest that regulation of LHR function by sequential changes in the expression pattern of LHR isoforms may play a role in the early deviation of the dominant follicle, as observed in B. indicus breeds.
Decline in the negative association between low birth weight and cognitive ability
Authors: Goisis Alice , Özcan Berkay , Myrskylä Mikko
Published: December 2016

Significance

Many studies have shown that children with a low birth weight (less than 2.5 kg) have worse cognitive ability than children with a normal birth weight. No existing study has analyzed whether, given the advances in neonatology and obstetric practice that have occurred over the past 50 years in developed contexts, the association between low birth weight and cognitive ability has changed over time. Using data from the 1958 National Child Development Study, the 1970 British Cohort Study, and the 2000–2002 Millennium Cohort Study, we show that the association between low birth weight and decreased cognitive ability has been more than halved between the 1958 and 1970 birth cohorts and the cohort born around the year 2001.
Spatial heterogeneity of climate change as an experiential basis for skepticism
Authors: Kaufmann Robert K. , Mann Michael L. , Gopal Sucharita , Liederman Jackie A. , Howe Peter D. , Pretis Felix , Tang Xiaojing , Gilmore Michelle
Published: December 2016

Significance

We develop a simple heuristic to measure local changes in climate based on the timing of record high and low temperatures. The metric shows local cooling and warming in the United States and captures two aspects of experiential learning that influence how the public perceives a change in climate: recency weighting and an emphasis on extreme events. We find that skepticism about whether the Earth is warming is greater in areas exhibiting cooling relative to areas that have warmed and that recent cooling can offset historical warming. This experiential basis for skepticism of climate change identifies obstacles to communicating ongoing changes in climate to the public and how these communications might be improved.
Fisheries management impacts on target species status
Authors: Melnychuk Michael C. , Peterson Emily , Elliott Matthew , Hilborn Ray
Published: December 2016

Significance

There is broad public interest in the health of our oceans and marine life at local, national, and international levels. In recent years there has been increasing concern about whether our fisheries can sustainably provide seafood without overfishing fish stocks. Several papers have described the global status of fish populations (i.e., their abundance and exploitation rates) and have hypothesized influences of fisheries management, but this report is unique in being a comprehensive analysis of how specific management attributes (which are numerous and operate simultaneously) affect population status across oceans, countries, and taxonomic groups. Our report integrates management policies and population ecology to assess sustainable harvesting outcomes of target species in marine fisheries; results have important global food security implications.
Persistence and biodegradation of oil at the ocean floor following
Deepwater Horizon
Authors: Bagby Sarah C. , Reddy Christopher M. , Aeppli Christoph , Fisher G. Burch , Valentine David L.
Published: December 2016

Significance

The
Deepwater Horizon
event led to an unprecedented discharge of ∼4.1 million barrels of oil to the Gulf of Mexico. The deposition of ∼4–31% of this oil to the seafloor has been quantified previously on a bulk basis. In this work, we assess the extent of degradation over 4 y postspill for each of 125 petroleum hydrocarbons that contaminated the seafloor. As expected, chemically simpler compounds broke down more quickly than complex compounds, but degradation rates also depended on environmental context: Breakdown often was faster before seafloor deposition than after and for oil trapped in small droplets than for oil in large particles. These results provide a basis to predict the long-term fate of seafloor oil.
FGF14 is a regulator of KCNQ2/3 channels
Authors: Pablo Juan Lorenzo , Pitt Geoffrey S.
Published: December 2016

Significance

KCNQ K
+
channels and voltage-gated sodium channels (VGSCs) are both critical determinants of neuronal excitability and highly localized to the axon initial segment (AIS). Although these two classes of ion channels are functionally and spatially linked, information about their coregulation is lacking. Here we report that the VGSC regulator fibroblast growth factor 14 (FGF14) is a regulator of KCNQ channels. FGF14 knockdown in hippocampal neurons leads to loss of KCNQ localization to the AIS and reduced KCNQ currents. Expressed heterologously, FGF14 is a positive regulator of KCNQ channels, ruling out an indirect VGSC-related effect. FGF14 is capable of binding VGSCs and KCNQ2 simultaneously at distinct interaction interfaces, providing a molecular basis for how these channel classes are coregulated in neurons.
Glacial ocean circulation and stratification explained by reduced atmospheric temperature
Authors: Jansen Malte F.
Published: December 2016

Significance

To understand climatic swings between glacial and interglacial climates we need to explain the observed fluctuations in atmospheric carbon dioxide (CO
2
), which in turn are most likely driven by changes in the deep ocean circulation. This study presents a model for differences in the deep ocean circulation between glacial and interglacial climates consistent with both our physical understanding and various proxy observations. The results suggest that observed changes in ocean circulation and stratification are caused directly by atmospheric cooling or warming, which has important implications for our interpretation of glacial–interglacial transitions. In particular, the direct link between atmospheric temperature and ocean circulation changes supports the notion of a positive feedback loop between atmospheric temperature, ocean circulation, and atmospheric CO
2
.
Chemical distinctions between Stradivari’s maple and modern tonewood
Authors: Tai Hwan-Ching , Li Guo-Chian , Huang Shing-Jong , Jhu Chang-Ruei , Chung Jen-Hsuan , Wang Bo Y. , Hsu Chia-Shuo , Brandmair Brigitte , Chung Dai-Ting , Chen Hao Ming , Chan Jerry Chun Chung
Published: December 2016

Significance

There have been numerous attempts to elucidate the “secrets” of Stradivari violins, to explain why functional replacements have not been reproduced over the past two centuries. Whether there are systematic differences between Stradivari violins and later imitations has been heatedly debated. Our analysis of Stradivari’s maples from three independent sources showed reproducible differences in chemical compositions compared with modern maples. Stradivari’s use of mineral-treated maples belonged to a forgotten tradition unknown to later violin makers. His maple also appeared to be transformed by aging and vibration, resulting in a unique composite material unavailable to modern makers. Modern chemical analyses may, therefore, improve our understanding of Stradivari’s unique craft and inspire the development of novel material approaches in instrument making.
Edge effects enhance carbon uptake and its vulnerability to climate change in temperate broadleaf forests
Authors: Reinmann Andrew B. , Hutyra Lucy R.
Published: December 2016

Significance

A large proportion of the world’s forest is highly fragmented, but our understanding of forest carbon dynamics and their response to climate largely comes from unfragmented forests, which presents an important mismatch between landscapes that we study and those that we aim to characterize. We find that temperate broadleaf forest growth and biomass in southern New England increase substantially from forest interior to edge. However, forest growth reductions with climate stress increase with proximity to the edge, pointing to important interactions between forest fragmentation and climate change. We show that, by not accounting for edge effects, current approaches to quantifying regional and global carbon balance may underestimate carbon sequestration and not accurately represent forest growth response to future climate change.
Global risk model for vector-borne transmission of Zika virus reveals the role of El Niño 2015
Authors: Caminade Cyril , Turner Joanne , Metelmann Soeren , Hesson Jenny C. , Blagrove Marcus S. C. , Solomon Tom , Morse Andrew P. , Baylis Matthew
Published: December 2016

Significance

This study quantifies the impact of climate variability on Zika virus (ZIKV) transmission by two mosquito vectors with distinct characteristics:
Aedes aegypti and Aedes albopictus
. Observed climate data were used to dynamically drive a two vectors–one host
R
0
epidemiological model. Our modeling results indicate that temperature conditions related to the 2015 El Niño climate phenomenon were exceptionally conducive for mosquito-borne transmission of ZIKV over South America. The virus is believed to have entered the continent earlier in 2013. This finding implicates that such a large ZIKV outbreak occurred not solely because of the introduction of ZIKV in a naive population, but because the climatic conditions were optimal for mosquito-borne transmission of ZIKV over South America in 2015.
Disrupting the blood–brain barrier by focused ultrasound induces sterile inflammation
Authors: Kovacs Zsofia I. , Kim Saejeong , Jikaria Neekita , Qureshi Farhan , Milo Blerta , Lewis Bobbi K. , Bresler Michele , Burks Scott R. , Frank Joseph A.
Published: December 2016

Significance

Pulsed focused ultrasound (pFUS) with systemic microbubble (MB) infusion is a noninvasive technique that opens the blood–brain barrier (BBB) and is currently advocated for increasing drug or gene delivery in neurological diseases. The opening of the BBB by pFUS+MB resulted in immediate damage-associated molecular patterns that led to a sterile inflammation response within the parenchyma that lasted 24 h. Currently, pFUS+MB exposure is under consideration as an adjuvant in the treatment in malignancy or neurodegenerative disease. These results demonstrate that pFUS+MB induces a sterile inflammatory response compatible with ischemia or mild traumatic brain injury. Further investigation will be required before translation to clinical trials.
Enhanced strength and temperature dependence of mechanical properties of Li at small scales and its implications for Li metal anodes
Authors: Xu Chen , Ahmad Zeeshan , Aryanfar Asghar , Viswanathan Venkatasubramanian , Greer Julia R.
Published: December 2016

Significance

Li metal anodes play a crucial part in next-generation Li ion and “beyond-Li ion” batteries. The issue of dendrites remains a major hurdle, and mechanical suppression through the use of solid electrolytes proves to be a promising solution. However, a lack of knowledge of mechanical properties of lithium metal at the micrometer scale limits our understanding of the mechanical interactions at the electrolyte/electrode interface. In this work, we report results on the mechanical properties of Li, specifically that Li exhibits a strong size effect at room and elevated temperature. First-principle calculations show a high level of elastic anisotropy. Based on the results, we present rational guidelines for anode/electrolyte selection and operating condition that will lead to better cycling performance.
Observing the formation of ice and organic crystals in active sites
Authors: Campbell James M. , Meldrum Fiona C. , Christenson Hugo K.
Published: December 2016

Significance

Crystal nucleation—the first appearance of a crystalline phase where there was none before—usually occurs at the surface of a foreign material. Ice formation in the atmosphere is dependent upon the number and type of aerosol particles present, but little is known about why some are more effective than others. Here we investigate the role of surface topography in promoting crystallization of ice and different organic crystals and show that acute geometries are highly effective in promoting the growth of a confined crystalline phase, which then gives rise to a bulk phase. This is relevant to crystallization in a large number of real-world systems such as industrial film growth and our climate.
Linking parasite populations in hosts to parasite populations in space through Taylor's law and the negative binomial distribution
Authors: Cohen Joel E. , Poulin Robert , Lagrue Clément
Published: December 2016

Significance

The spatial distribution of individuals of any species is a basic concern of ecology. The spatial distribution of parasites matters to control and conservation of parasites that affect human and nonhuman populations. This paper develops a quantitative theory to predict the spatial distribution of parasites based on the distribution of parasites in hosts and the spatial distribution of hosts. The theory is tested using observations of metazoan hosts and parasites in the littoral zone of four lakes in Otago, New Zealand. We infer that the spatial distribution of parasites depends crucially on high local correlations of hosts' parasite loads. If so, local hotspots of correlated parasite loads should be considered in parasite control and conservation.
Why fascists took over theReichstagbut have not captured the Kremlin: a comparison of Weimar Germany and post-Soviet Russia
Authors: Kailitz Steffen , Umland Andreas
Published: December 2016

Like Weimar Germany, contemporary Russia is home to fascist actors and widespread nationalism. But unlike interwar Germany, the party system in post-Soviet Russia is heavily manipulated and civil society remains underdeveloped. This means that fascists have not had a chance to use elections or to penetrate civil society in order to build up political support. The continuing presence of a resolutely authoritarian, yet non-fascist “national leader” (Vladimir Putin) keeps the country from becoming a liberal democracy but it also, for now, makes it less likely that the regime will become fascist.
Sablefish mortality associated with whale depredation in Alaska
Authors: Peterson Megan J. , Hanselman Dana
Published: December 2016

Killer whale (Orcinus orca) and sperm whale (Physeter macrocephalus) depredation (whales removing or damaging fish caught on fishing gear) can reduce catch rates and decrease the accuracy of fish stock assessments. This study advances our understanding of the impact of whale depredation on the commercial sablefish (Anoplopoma fimbria) fishery in Alaska and evaluates the impact depredation may have on the annual federal sablefish assessment. A statistical modelling approach was used to estimate the whale effect on commercial sablefish fishery catch rates; killer whale depredation was more severe (catch rates declined by 45%–70%) than sperm whale depredation (24%–29%). Total estimated sablefish catch removals 1995–2014 ranged from 1251 t to 2407 t by killer whales in western Alaska management areas and 482 t to 1040 t by sperm whales in the Gulf of Alaska 2001–2014. Including sablefish mortality due to whale depredation on the commercial fishery in the sablefish stock assessment resulted in a 1% reduction in the recommended quota. Accounting for sablefish mortality due to whale depredation in the commercial fishery in the sablefish assessment will occur tandem with correcting for depredation on the annual National Marine Fisheries Service longline survey, the primary survey index used in the assessment.
Long-term outcomes after carbon-ion radiotherapy for oral mucosal malignant melanoma
Authors: Naganawa Kensuke , Koto Masashi , Takagi Ryo , Hasegawa Azusa , Ikawa Hiroaki , Shimozato Kazuo , Kamada Tadashi , Okamoto Yoshitaka ,   the Organizing Committee for the Working Group for Head-and-Neck Cancer
Published: December 2016

Oral mucosal malignant melanoma (OMM) is extremely rare and has a poor prognosis. Owing to its rarity, it has not yet been possible to establish an optimal treatment modality. The objective of this study was to evaluate the long-term efficacy of carbon-ion radiotherapy (C-ion RT) for OMM. Between 1997 and 2013, 19 patients with OMM were treated with C-ion RT alone. Patient ages ranged from 44 to 84 years (median, 69 years). Nine men and 10 women were included. OMMs were restaged in accordance with the seventh edition of the tumour/node/metastasis (TNM) Staging System of the International Union Against Cancer. Before treatment, 14 patients had T3 disease and 5 had T4a disease. Three patients were classified as having N1 disease. All patients were classified as having M0. The hard palate was the most frequently involved oral subsite. All patients were treated with 57.6 Gy (relative biological effectiveness) in 16 fractions. The median follow-up period was 61 months (range, 8–190 months). The 5-year local control, overall survival and progression-free survival rates were 89.5%, 57.4% and 51.6%, respectively. For local control and overall survival, T classification was found to be a significant prognostic factor. Grade 2 and 3 osteoradionecrosis was observed in three and four patients, respectively. The presence of teeth within the planning target volume was a significant risk factor for developing osteoradionecrosis. C-ion RT was an effective treatment option with acceptable toxicity for OMM.
Tale of J1328+2752: a misaligned double–double radio galaxy hosted by a binary black hole?
Authors: Nandi S. , Jamrozy M. , Roy R. , Larsson J. , Saikia D. J. , Baes M. , Singh M.
Published: December 2016

We present a radio and optical study of the double–double radio galaxy J1328+2752 based on new low-frequency Giant Metrewave Radio Telescope observations and Sloan Digital Sky Survey (SDSS) data. The radio data were used to investigate the morphology and to perform a spectral index analysis. In this source, we find that the inner double is misaligned by ∼30° from the axis of the outer diffuse structure. The SDSS spectrum shows that the central component has double-peaked line profiles with different emission strengths. The average velocity off-set of the two components is 235 ± 10.5 km s−1. The misaligned radio morphology along with the double-peaked emission lines indicate that this source is a potential candidate binary supermassive black hole. This study further supports mergers as a possible explanation for repeated jet activity in radio sources.