bluuebunny/crossref_metadata_2025 huggingface dataset:
Water permeation through single-layer graphyne membrane
Authors: Kou Jianlong , Zhou Xiaoyan , Chen Yanyan , Lu Hangjun , Wu Fengmin , Fan Jintu
Published: August 2013

We report the molecular dynamics simulations of spontaneous and continuous permeation of water molecules through a single-layer graphyne-3 membrane. We found that the graphyne-3 membrane is more permeable to water molecules than (5, 5) carbon nanotube membranes of similar pore diameter. The remarkable hydraulic permeability of the single-layer graphyne-3 membrane is attributed to the hydrogen bond formation, which connects the water molecules on both sides of the monolayer graphyne-3 membrane and aids to overcome the resistance of the nanopores, and to the relatively lower energy barrier at the pore entrance. Consequently, the single-layer graphyne-3 membrane has a great potential for application as membranes for desalination of sea water, filtration of polluted water, etc.
Dynamic simulation of concentrated macromolecular solutions with screened long-range hydrodynamic interactions: Algorithm and limitations
Authors: Ando Tadashi , Chow Edmond , Skolnick Jeffrey
Published: August 2013

Hydrodynamic interactions exert a critical effect on the dynamics of macromolecules. As the concentration of macromolecules increases, by analogy to the behavior of semidilute polymer solutions or the flow in porous media, one might expect hydrodynamic screening to occur. Hydrodynamic screening would have implications both for the understanding of macromolecular dynamics as well as practical implications for the simulation of concentrated macromolecular solutions, e.g., in cells. Stokesian dynamics (SD) is one of the most accurate methods for simulating the motions of N particles suspended in a viscous fluid at low Reynolds number, in that it considers both far-field and near-field hydrodynamic interactions. This algorithm traditionally involves an O(N3) operation to compute Brownian forces at each time step, although asymptotically faster but more complex SD methods are now available. Motivated by the idea of hydrodynamic screening, the far-field part of the hydrodynamic matrix in SD may be approximated by a diagonal matrix, which is equivalent to assuming that long range hydrodynamic interactions are completely screened. This approximation allows sparse matrix methods to be used, which can reduce the apparent computational scaling to O(N). Previously there were several simulation studies using this approximation for monodisperse suspensions. Here, we employ newly designed preconditioned iterative methods for both the computation of Brownian forces and the solution of linear systems, and consider the validity of this approximation in polydisperse suspensions. We evaluate the accuracy of the diagonal approximation method using an intracellular-like suspension. The diffusivities of particles obtained with this approximation are close to those with the original method. However, this approximation underestimates intermolecular correlated motions, which is a trade-off between accuracy and computing efficiency. The new method makes it possible to perform large-scale and long-time simulation with an approximate accounting of hydrodynamic interactions.
Modeling electron density distributions from X-ray diffraction to derive optical properties: Constrained wavefunction versus multipole refinement
Authors: Hickstein Daniel D. , Cole Jacqueline M. , Turner Michael J. , Jayatilaka Dylan
Published: August 2013

The rational design of next-generation optical materials requires an understanding of the connection between molecular structure and the solid-state optical properties of a material. A fundamental challenge is to utilize the accurate structural information provided by X-ray diffraction to explain the properties of a crystal. For years, the multipole refinement has been the workhorse technique for transforming high-resolution X-ray diffraction datasets into the detailed electron density distribution of crystalline material. However, the electron density alone is not sufficient for a reliable calculation of the nonlinear optical properties of a material. Recently, the X-ray constrained wavefunction refinement has emerged as a viable alternative to the multipole refinement, offering several potential advantages, including the calculation of a wide range of physical properties and seeding the refinement process with a physically reasonable starting point. In this study, we apply both the multipole refinement and the X-ray constrained wavefunction technique to four molecules with promising nonlinear optical properties and diverse structural motifs. In general, both techniques obtain comparable figures of merit and generate largely similar electron densities, demonstrating the wide applicability of the X-ray constrained wavefunction method. However, there are some systematic differences between the electron densities generated by each technique. Importantly, we find that the electron density generated using the X-ray constrained wavefunction method is dependent on the exact location of the nuclei. The X-ray constrained wavefunction refinement makes smaller changes to the wavefunction when coordinates from the Hartree–Fock-based Hirshfeld atom refinement are employed rather than coordinates from the multipole refinement, suggesting that coordinates from the Hirshfeld atom refinement allow the X-ray constrained wavefunction method to produce more accurate wavefunctions. We then use the experimentally derived wavefunctions to calculate the molecular dipole moment, polarizability, hyperpolarizability, and refractive index and show that these are in good agreement with the values calculated using ab initio methods. Thus, this study shows that experimental wavefunctions can be reliably generated from X-ray diffraction datasets, and that optical properties can be reliably calculated from these wavefunctions. Such a concerted interplay of experiment and computation via the X-ray constrained wavefunction refinement stands to enable the molecular engineering of tailor-made next-generation optical materials.
Experimental quantification of inverse energy cascade in deep rotating turbulence
Authors: Yarom Ehud , Vardi Yuval , Sharon Eran
Published: August 2013

We experimentally study the characteristics of an inverse energy cascade in deep rotating turbulence. Experiments were performed in a rotating cylindrical water tank with energy injection at a small scale. The steady state energy spectrum of the horizontal velocity field at scales larger than the injection scale is very well described by the 2D inverse energy cascade spectrum. Transient energy spectra evolve via 2D-like inverse cascade, with energy transfer from small to large scales. The measured energy transfer rates are in good quantitative agreement with the predictions for 2D turbulence.
A structure-based model fails to probe the mechanical unfolding pathways of the titin I27 domain
Authors: Kouza Maksim , Hu Chin-Kun , Li Mai Suan , Kolinski Andrzej
Published: August 2013

We discuss the use of a structure based Cα-Go model and Langevin dynamics to study in detail the mechanical properties and unfolding pathway of the titin I27 domain. We show that a simple Go-model does detect correctly the origin of the mechanical stability of this domain. The unfolding free energy landscape parameters xu and ΔG‡, extracted from dependencies of unfolding forces on pulling speeds, are found to agree reasonably well with experiments. We predict that above v = 104 nm/s the additional force-induced intermediate state is populated at an end-to-end extension of about 75 Å. The force-induced switch in the unfolding pathway occurs at the critical pulling speed vcrit ≈ 106–107 nm/s. We argue that this critical pulling speed is an upper limit of the interval where Bell's theory works. However, our results suggest that the Go-model fails to reproduce the experimentally observed mechanical unfolding pathway properly, yielding an incomplete picture of the free energy landscape. Surprisingly, the experimentally observed intermediate state with the A strand detached is not populated in Go-model simulations over a wide range of pulling speeds. The discrepancy between simulation and experiment is clearly seen from the early stage of the unfolding process which shows the limitation of the Go model in reproducing unfolding pathways and deciphering the complete picture of the free energy landscape.
Spontaneous electromagnetic fluctuations in unmagnetized plasmas. IV. Relativistic form factors of aperiodic Lorentzian modes
Authors: Felten T. , Schlickeiser R.
Published: August 2013

Closed analytical expressions for the electromagnetic fluctuation spectra in unmagnetized plasmas are derived using fully relativistic dispersion functions and form factors for the important class of isotropic form-invariant Lorentzian plasma particle distribution functions. Such distribution functions occur frequently in cosmic plasmas due to the presence of suprathermal charged particles and energetic cosmic ray particles. The results are illustrated for the important special case of aperiodic fluctuations. The collective, transverse, damped aperiodic mode, discovered before in nonrelativistic Maxwellian particle distributions, also exists in Lorentzian electron-proton particle distributions, now with the damping rate γ∝−k3 for all wavenumber values, resulting from the presence of relativistic particles in the tail of the Lorentzian distribution. For longitudinal electric field, fluctuations no damped or growing aperiodic collective mode exists in Lorentzian plasmas. The existence of a damped, collective, transverse, aperiodic mode is not in conflict with earlier general instability studies excluding the existence of growing aperiodic collective modes in isotropic plasmas.
Second-order radio frequency kinetic theory revisited: Resolving inconsistency with conventional fluid theory
Authors: Chen Jiale , Gao Zhe
Published: August 2013

The second-order velocity distribution function was calculated from the second-order rf kinetic theory [Jaeger et al., Phys. Plasmas 7, 641 (2000)]. However, the nonresonant ponderomotive force in the radial direction derived from the theory is inconsistent with that from the fluid theory. The inconsistency arises from that the multiple-timescale-separation assumption fails when the second-order Vlasov equation is directly integrated along unperturbed particle orbits. A slowly ramped wave field including an adiabatic turn-on process is applied in the modified kinetic theory in this paper. Since this modification leads only to additional reactive/nonresonant response relevant with the secular resonant response from the previous kinetic theory, the correct nonresonant ponderomotive force can be obtained while all the resonant moments remain unchanged.
Effective charge of ionic microgel particles in the swollen and collapsed states: The role of the steric microgel-ion repulsion
Authors: Moncho-Jordá A.
Published: August 2013

In this work the system formed by charged (ionic) microgels in the presence of monovalent salt is investigated by solving numerically the Ornstein-Zernike integral equations within the Hypernetted-Chain approximation. The ionic density profiles, effective interaction between microgel particles, and the effective charge of the particles are calculated. In addition to the electrostatic interaction, the excluded-volume repulsion between the microgel particle and the ions is also explicitly taken into account. Although this steric interaction is irrelevant in the swollen state (when the packing fraction of the polymer network is low), it becomes a very important contribution close to the de-swollen state, hindering the counterion penetration inside the microgel mesh. The theoretical predictions indicate that the ionic density profiles are strongly affected by the degree of swelling, going from a volumetric distribution of counterions in the swollen state to a surface accumulation outside the particle that becomes more important as the particle shrinks. The electrostatic effective interaction between pairs of microgel particles is shown to be the result of a complex interplay between electrostatic and depletion effects that strongly depend on the bare charge density of the particle. For sufficiently charged microgel particles, the steric exclusion leads to a less efficient screening of the microgel charge near the de-swollen configuration, and so to a significant increase of the effective charge of the microgel particle.
Umbral calculus and Sheffer sequences of polynomials
Authors: Kim Taekyun , Kim Dae San , Mansour Toufik , Rim Seog-Hoon , Schork Matthias
Published: August 2013

In this paper, we investigate some properties of Sheffer sequences of polynomials arising from umbral calculus. From these properties, we derive new and interesting identities between Sheffer sequences of polynomials. An application to normal ordering is presented.
Taylor series expansion based multidimensional image reconstruction for confocal and 4pi microscopy
Authors: Dilipkumar Shilpa , Pratim Mondal Partha
Published: August 2013

We propose and experimentally demonstrate a three-dimensional (3D) image reconstruction methodology based on Taylor series approximation (TSA) in a Bayesian image reconstruction formulation. TSA incorporates the requirement of analyticity in the image domain, and acts as a finite impulse response filter. This technique is validated on images obtained from widefield, confocal laser scanning fluorescence microscopy and two-photon excited 4pi (2PE-4pi) fluorescence microscopy. Studies on simulated 3D objects, mitochondria-tagged yeast cells (labeled with Mitotracker Orange) and mitochondrial networks (tagged with Green fluorescent protein) show a signal-to-background improvement of 40% and resolution enhancement from 360 to 240 nm. This technique can easily be extended to other imaging modalities (single plane illumination microscopy (SPIM), individual molecule localization SPIM, stimulated emission depletion microscopy and its variants).
Microlattices as architected thin films: Analysis of mechanical properties and high strain elastic recovery
Authors: Maloney Kevin J. , Roper Christopher S. , Jacobsen Alan J. , Carter William B. , Valdevit Lorenzo , Schaedler Tobias A.
Published: August 2013

Ordered periodic microlattices with densities from 0.5 mg/cm3 to 500 mg/cm3 are fabricated by depositing various thin film materials (Au, Cu, Ni, SiO2, poly(C8H4F4)) onto sacrificial polymer lattice templates. Young's modulus and strength are measured in compression and the density scaling is determined. At low relative densities, recovery from compressive strains of 50% and higher is observed, independent of lattice material. An analytical model is shown to accurately predict the transition between recoverable “pseudo-superelastic” and irrecoverable plastic deformation for all constituent materials. These materials are of interest for energy storage applications, deployable structures, and for acoustic, shock, and vibration damping.
Contrasting behavior of the structural and magnetic properties in Mn- and Fe-doped In2O3 films
Authors: Feng Qi , Blythe Harry J. , Jiang Feng-Xian , Xu Xiao-Hong , Heald Steve M. , Fox A. Mark , Gehring Gillian A.
Published: August 2013

We have observed room temperature ferromagnetism in In2O3 thin films doped with either 5 at.% Mn or Fe, prepared by pulsed laser deposition at substrate temperatures ranging from 300 to 600 °C. The dependence of saturation magnetization on grain size was investigated for both types of In2O3 films. It is revealed that, for the Mn-doped films, the magnetization was largest with small grains, indicating the importance of grain boundaries. In contrast, for Fe-doped films, the largest magnetization was observed with large grains.
Improving Li2O2 conductivity via polaron preemption: An ab initio study of Si doping
Authors: Timoshevskii Vladimir , Feng Zimin , Bevan Kirk H. , Goodenough John , Zaghib Karim
Published: August 2013

We report on ab initio electronic structure simulations of Li2O2, where 1.6% of lithium atoms are substituted by silicon. It is demonstrated that this leads to the formation of conducting impurity states in the band gap of Li2O2. We show that these states originate from the antibonding orbitals of the oxygen pairs and are remarkably stable against possible polaron formation (upon electron injection). Through this polaron preemption mechanism, the proposed compound is expected to show significantly higher electronic mobility than stoichiometric Li2O2, which could have significant applications in lithium-air batteries.
Effects of local defect growth in direct-drive cryogenic implosions on OMEGA
Authors: Igumenshchev I. V. , Goncharov V. N. , Shmayda W. T. , Harding D. R. , Sangster T. C. , Meyerhofer D. D.
Published: August 2013

Spherically symmetric, low-adiabat (adiabat α ≲ 3) cryogenic direct-drive-implosion experiments on the OMEGA laser [T. R. Boehly et al., Opt. Commun. 133, 495 (1995)] yield less than 10% of the neutrons predicted in one-dimensional hydrodynamic simulations. Two-dimensional hydrodynamic simulations suggest that this performance degradation can be explained assuming perturbations from isolated defects of submicron to tens-of-micron scale on the outer surface or inside the shell of implosion targets. These defects develop during the cryogenic filling process and typically number from several tens up to hundreds for each target covering from about 0.2% to 1% of its surface. The simulations predict that such defects can significantly perturb the implosion and result in the injection of about 1 to 2 μg of the hot ablator (carbon-deuterium) and fuel (deuterium-tritium) materials from the ablation surface into the targets. Both the hot mass injection and perturbations of the shell reduce the final shell convergence ratio and implosion performance. The injected carbon ions radiatively cool the hot spot, reducing the fuel temperature, and further reducing the neutron yield. The negative effect of local defects can be minimized by decreasing the number and size of these defects and/or using more hydrodynamically stable implosion designs with higher shell adiabat.
Field to thermo-field to thermionic electron emission: A practical guide to evaluation and electron emission from arc cathodes
Authors: Benilov M. S. , Benilova L. G.
Published: August 2013

This work is concerned with devising a method of evaluation of electron emission in the framework of the Murphy-Good theory, which would be as simple and computationally efficient as possible while being accurate in the full range of conditions of validity of the theory. The method relies on Padé approximants. A comparative study of electron emission from cathodes of arcs in ambient gas and vacuum arcs is performed with the use of this method. Electron emission from cathodes of arcs in ambient gas is of thermionic nature even for extremely high gas pressures characteristic of projection and automotive arc lamps and is adequately described by the Richardson-Schottky formula. The electron emission from vaporizing (hot) cathodes of vacuum arcs is of thermo-field nature and is adequately described by the Hantzsche fit formula. Since no analytical formulas are uniformly valid for field to thermo-field to thermionic emission, a numerical evaluation of the Murphy-Good formalism is inevitable in cases where a unified description of the full range of conditions is needed, as is the general case of plasma-cathode interaction in vacuum arcs, and the technique proposed in this work may be the method of choice to this end.
Dissipative particle dynamics simulations on self-assembly of rod-coil-rod triblock copolymers in a rod-selective solvent
Authors: Huang Jian-Hua , Fan Zhong-Xiang , Ma Ze-Xin
Published: August 2013

Self-assembly of rod-coil-rod ABA triblock copolymers in a rod-selective solvent is investigated by using dissipative particle dynamics simulations. The morphologies of the self-assembled aggregates are dependent on the number of copolymers in the aggregate and the rod length of the copolymer. We observe vesicles at short rod block and bowl-like aggregates at slightly longer rod block. In the vesicle region near the phase boundary, metastable bowl-like aggregates can be observed and be transformed into vesicles by annealing process. A transition from the bowl-like structure to the vesicle is observed by increasing the solvophobicity of the mid-coil block. In this study, the difference between the self-assembly of fully flexible ABA triblock copolymer and that of rod-coil-rod triblock copolymer is also discussed.
Evolution of strain in aluminum gallium nitride/gallium nitride high electron mobility transistors under on-state bias
Authors: Ghassemi H. , Lang A. , Johnson C. , Wang R. , Song B. , Phillips P. , Qiao Q. , Klie R. F. , Xing H. G. , Taheri M. L.
Published: August 2013

On-state degradation of AlGaN/GaN high electron mobility transistors (HEMTs) was quantified as a function of defect generation and strain evolution using high-resolution transmission electron microscopy. Observation of devices under on-state stress conditions elucidated defect formation mechanisms, which is known to be caused by hot electrons. Geometric phase analysis indicated a ∼25% decrease of the in-plane tensile strain in the AlGaN barrier after extended bias. Changes in sheet polarization charge density were estimated based on observations of the defect formation and resulting strain relaxation. We propose three regimes of degradation during HEMT device operation, and suggest the presence of a critical point at which defects become stable or permanent.
Fast switching characteristics in vertical organic field effect transistors
Authors: Greenman Michael , Ben-Sasson Ariel J. , Chen Zhihua , Facchetti Antonio , Tessler Nir
Published: August 2013

We report a theoretical and experimental investigation of the switching characteristics in patterned-source vertical field effect transistors. Experimentally we show that the layered structure gives rise to capacitances coupling of the potential between the drain and source electrodes. By removing the extrinsic gate-source capacitance we are able to demonstrate unprecedented sub-2 μs switching and current levels of 3 A/cm2. Theoretically, using a 2D drift-diffusion model, we show that the intrinsic response depends on two processes: the formation of the virtual electrode and the injection through it to form the vertical channel. The importance of the source structure parameter to achieve ultimate speed is discussed.
Split-ring resonators interacting with a magnetic field at visible frequencies
Authors: Tomioka T. , Kubo S. , Nakagawa M. , Hoga M. , Tanaka T.
Published: August 2013

Split-ring resonators (SRRs) are attractive owing to the interaction with a magnetic field of incident light. Here, we report the fabrication of uniform arrays of about 360 million Au SRRs with a line width of approximately 50 nm by reactive-monolayer-assisted thermal nanoimprint lithography over a 5-mm square area. Furthermore, we present an experimental demonstration of the oscillation of free electrons excited by a magnetic field at 690 nm in the visible frequency region. The fabrication and optical investigation of SRR arrays over such large areas will facilitate opportunities to realize advanced optical devices.
Quality of epitaxial InAs nanowires controlled by catalyst size in molecular beam epitaxy
Authors: Zhang Zhi , Lu Zhen-Yu , Chen Ping-Ping , Xu Hong-Yi , Guo Ya-Nan , Liao Zhi-Ming , Shi Sui-Xing , Lu Wei , Zou Jin
Published: August 2013

In this study, the structural quality of Au-catalyzed InAs nanowires grown by molecular beam epitaxy is investigated. Through detailed electron microscopy characterizations and analysis of binary Au-In phase diagram, it is found that defect-free InAs nanowires can be induced by smaller catalysts with a high In concentration, while comparatively larger catalysts containing less In induce defected InAs nanowires. This study indicates that the structural quality of InAs nanowires can be controlled by the size of Au catalysts when other growth conditions remain as constants.
Terahertz generation by GaAs nanowires
Authors: Trukhin V. N. , Buyskikh A. S. , Kaliteevskaya N. A. , Bourauleuv A. D. , Samoilov L. L. , Samsonenko Yu. B. , Cirlin G. E. , Kaliteevski M. A. , Gallant A. J.
Published: August 2013

We report on the emission of terahertz (THz) radiation from p-doped and intentionally undoped GaAs nanowires (NWs). The THz emission has been associated with the contributions of the drift and diffusion currents, excited in the 1D NWs. Taking into account the filling factor, the THz power emission for the NWs is shown to be 40 times more than that of the bulk epitaxial GaAs substrate. By analyzing the non-equilibrium dynamics of the photoinduced carriers in the nanowires, the charge carrier lifetime is shown to be of the order of 3 ns and the drift velocity 105 m/s.
Dynamic self-assembly of particles in an expanding channel flow
Authors: Sun Dongke , Wang Yong , Jiang Di , Xiang Nan , Chen Ke , Ni Zhonghua
Published: August 2013

Microfluidic particle crystals, which were previously observed in experiment, can be formed under the mediation of fluid flow. In this letter, we numerically investigated the dynamics of multi particles in an expanding channel, analyzed the fluid-particle interactions during the self-assembling, and revealed the underlying mechanism of the dynamic self-assembly of particles in the presence of fluid flow. Our results show that a pearls-string-like chain can be formed at low Reynolds numbers without external force fields. This research will possibly facilitate the utilization of expanding channel flows to obtain the microfluidic particle crystals for advanced applications in biomedicine and materials synthesis.
Phase transition and high piezoelectricity in (Ba,Ca)(Ti1−xSnx)O3 lead-free ceramics
Authors: Zhu Li-Feng , Zhang Bo-Ping , Zhao Xiao-Kun , Zhao Lei , Yao Fang-Zhou , Han Xi , Zhou Peng-Fei , Li Jing-Feng
Published: August 2013

The phase structure in the (Ba,Ca)(Ti1−xSnx)O3 lead-free ceramics was evolved from inceptive orthorhombic (O) at 0 ≤ x ≤ 0.04 to a two-phase coexistence of pseudocubic-orthorhombic (PC-O) at 0.06 ≤ x ≤ 0.10 and further to a multiphase coexistence of rhombohedral-pseudocubic-orthorhombic (R-PC-O) at x = 0.11. Due to the multiphase coexistence of R-PC-O at room temperature proved by X-ray diffraction, dielectric constant εr and differential scanning calorimetry, an ultrahigh piezoelectric coefficient d33 = 670 pC/N and electrostrain 0.061% were achieved. The high d33 over 520 pC/N was stabilized in a wide compositional range of 0.07 ≤ x ≤ 0.11, suggesting that (Ba,Ca)(Ti,Sn)O3 ceramics are a promising candidate for the lead-free piezoelectric ceramics.
Design optimized membrane-based flexible paper accelerometer with silver nano ink
Authors: Zhang Yuanfeng , Lei Chupeng , Soo Kim Woo
Published: August 2013

Here we report a highly sensitive single-axis membrane-type paper accelerometer. The accelerometer is consisted of a suspended parallel-plate sensing capacitor prepared by cost-effective nano ink printing technologies on a flexible paper substrate. The proof mass and suspension bridge structures of the accelerometer are designed based on the simulation results for the optimization of sensitivity. Vertical acceleration sensitivity of the optimized design with long ellipse-shaped bridges and round-shaped proof mass can reach 20 fF/g at z-axis acceleration of 1–10 g.
Fractal Spatialities
Authors: Chettiparamb Angelique
Published: August 2013

This paper argues for the use of ‘fractals’ in theorising sociospatial relations. From a realist position, a nonmathematical but nonmetaphoric and descriptive view of ‘fractals’ is advanced. Insights from the natural sciences are combined with insights on the position of the observer from Luhmann and notions of assemblages and repetitions from Deleuze. It is argued that the notion of ‘fractals’ can augment current understanding of sociospatialities in three ways. First, it can pose questions about the scalar position of the observer or the grain of observation; second, as a signifier of particular attributes, it prompts observation and description of particular structuring processes; and third, the epistemic access afforded by the concept can open up possibilities for transformative interventions and thereby inform the same. The theoretical usefulness of the concept is demonstrated by discussing the territory, place, scale, and networks (TPSN) model for theorising sociospatial relations advanced by B Jessop, N Brenner, and M Jones in their 2008 paper “Theorizing sociospatial relations”, published in this journal (volume 26, pages 389–401). It is suggested that a heuristic arising from a ‘fractal’ ontology can contribute to a polymorphous, as opposed to polyvalent, understanding of sociospatial relations.
On Moral Substance and Visual Obscurity in Policies and Practice of State Expansion
Authors: Sezneva Olga
Published: August 2013

What may the moment of territorial repossession and resettlement reveal to us about the practice of modern statehood? This paper discusses several key aspects of the Soviet occupation and incorporation of East Prussia in 1945–49: its juridical and administrative configuration into a zone of exception through militarized ‘closing’, the unequal invocation of citizenship rights and duties of Soviet settlers and the creation of legal and political limbo around German civilians, and the categorical production of social distinctions that separated the Soviet ‘us’ from the German ‘them’, together with a simultaneous articulation of a new, obscured identity—the spy. It demonstrates the thoroughly spatialized politics of settlement refracted through everyday experiences of travel, settlement, and cultural encounter. It argues on the basis of these findings that unintelligibility and ambiguity play a more complex role in statecraft than is often recognized.
Air Power as Police Power
Authors: Neocleous Mark
Published: August 2013

This paper makes a case for understanding air power through the lens of police. After first rethinking a key period in the history of air power (colonial bombing campaigns) as a police mechanism, the paper then moves to consider the impoverished conception of war and police in contemporary critical theory. The final section turns to perhaps the most pressing issue in current air power debates, namely drones, and suggests that a consideration of air power as police power helps us read drones as a continuation of the police logic inherent in air power since its inception.
Tracking and Tracing: Geographies of Logistical Governance and Labouring Bodies
Authors: Kanngieser Anja
Published: August 2013

Shifts in the production of national and global territories have coincided with new forms of biopolitical governance and surveillance, producing a simultaneous expansion and contraction of spatial and temporal mobility. In the logistics industries the mainstreaming of Radio Frequency Identification, the extended monitoring networks of GPS telematics, and the implementation of voice picking in warehouses have all had significant impacts on the mobilities of labour. Given the increasing scholarly interest in logistical geographies, this paper investigates these three advancements put to use for the regulation of bodies in the market environments of global capital from a technohistorical perspective, to provide a frame for further discourse on global supply chains, labour struggles, and security cultures.
The Interruption: Investigating Subjectivation and Affect
Authors: Dawney Leila
Published: August 2013

This paper contributes to current debates concerning affect and the nonrepresentational subject by introducing the concept of the interruption as a means of exploring the politics both of experience and of the feeling body. By thinking about the way in which affect is theorised in Spinoza's Ethics alongside a critique of the subject that draws on Foucault, I position the interruption as an event that elicits a mode of critique that enables an interrogation of both the sociality of affect and the somatisation of politics. This paper explores three events that I describe as interruptions, and demonstrates the utility and scope of such a concept.
Seasonal reproductive performance of crossbred ewes in intensive lamb-production systems
Authors: Fogarty N. M. , Mulholland J. G.
Published: August 2013

The lambing performance of 1179 crossbred ewes with 5540 joining records in three seasons (autumn, winter and spring) at two sites (Cowra and Wagga Wagga) was evaluated in three lamb-production systems (spring joining with autumn backup matings at both locations, with accelerated lambing at Cowra or annual autumn joining at Wagga Wagga) over 4 years. Two genotypes of ewes, Border Leicester × Merino (BLM) and Hyfer (Dorset × Merino composite), were used at both sites, with natural matings to Dorset, Suffolk or Hyfer rams. The following five traits were analysed separately at each site to evaluate ewe lambing performance: fertility, litter size, lambs born (per ewe joined), lambs weaned (per ewe joined) and weight of lamb weaned (per ewe joined). The mixed model included fixed effects for season of joining, ewe breed, ram group, ewe prejoining weight (spline) and their interactions, with ewe fitted as a random effect. The autumn (February) joinings had higher ewe fertility, litter size and overall lamb production than did joinings in spring (October and November), with winter (June) being intermediate. At the autumn joinings, the BLM ewes had higher fertility, lambs weaned and weight of lamb weaned than did the Hyfer ewes, although this was reversed at the spring joinings, causing significant season × ewe breed interactions. While litter size was larger in the autumn than in the spring for both breeds there was a much smaller seasonal effect among the Hyfer than BLM ewes. Prejoining ewe weight had a significant effect on all reproduction traits, with generally a curvilinear response with increasing weight. The interactions of weight with season × ewe breed were significant (P < 0.001) for all traits at Cowra and most traits at Wagga Wagga. Ram group was significant (P < 0.05) for most traits, with ewes joined to Hyfer rams having higher fertility than those joined to Suffolk. and with Dorset rams being intermediate. At Wagga Wagga, this was the case for spring joinings, but there was no difference between the ram groups in autumn, causing a significant ram × season interaction (P < 0.001). Ewe repeatability ranged from 0.15 to 0.25 for all traits. Using suitable breeds or genotypes, together with optimising management, could improve out-of-season lamb production.
The essential role of genetic resources in narrow-leafed lupin improvement
Authors: Berger Jens D. , Clements Jon C. , Nelson Matthew N. , Kamphuis Lars G. , Singh Karam B. , Buirchell Bevan
Published: August 2013

The narrow-leafed lupin (Lupinus angustifolius L.) is a legume with much to offer to agriculture and human wellbeing through its adaptation to nitrogen- and phosphorus-deficient, acid, sandy soils, and production of nutritious, very low glycemic index grain with manifold health benefits. However, the industry has exploited only a small fraction of the genetic and adaptive diversity of the species, reflecting a short and fragmented domestication history. Given declining global production, unlocking the potential residing in untapped sources of genetic diversity to maximise yield and value is critical for the future of the crop. To this end, a wide range of genetic resources is under evaluation. The Australian Lupin Collection comprises almost 4600 diverse, mostly wild accessions, many of which have been genotyped using DArT (Diversity Array Technology) markers, and collection sites characterised to facilitate ecophysiology of contrasting material. Additional exotic genetic resources include recombinant inbred line and mutant populations, as well as inter-specific crosses. These resources are being used to investigate specific adaptation and genetic and molecular control of key traits, all of which will be expedited by current efforts to provide a reference genome sequence for L. angustifolius. Genetic base broadening is the current breeding focus, combining distantly related wild and domestic material with elite cultivars in double-backcrosses or topcrosses, with dramatic effects on yield. In future this will be complemented by marker-based, targeted trait introgression to improve narrow-leafed lupin adaptation, quality/value, and fit into the farming system.
Consumption of residual pyrogenic carbon by wildfire
Authors: Santín C. , Doerr S. H. , Preston C. , Bryant R.
Published: August 2013

Pyrogenic carbon (PyC) produced during vegetation fires represents one of the most degradation resistant organic carbon pools and has important implications for the global carbon cycle. Its long-term fate in the environment and the processes leading to its degradation are the subject of much debate. Its consumption in subsequent fires is considered a potential major mechanism of abiotic PyC degradation; however, no quantitative data supporting this removal pathway have been published to date. To address this gap, we quantified consumption of residual PyC at the forest floor during an experimental fire, representative of a typical boreal wildfire, complemented by exploratory laboratory heating experiments. Labelled PyC (pinewood charcoal from a slash pile burn), in granular form contained in stainless steel mesh bags and as individual pieces, were placed at ~2-cm depth within the forest floor. The median mass loss of granular charcoal was 6.6%, with 75% of the samples losing <15%, and of individual pieces 15.1% with 75% of the samples losing <25%. The mass losses under laboratory conditions, although somewhat higher than in the field, confirm an overall low consumption of PyC. The limited losses of PyC found here do not support the widely held notion that wildfire is a major cause of loss for residual PyC.
Effects of fire severity on early recovery of Patagonian steppes
Authors: Ghermandi Luciana , Gonzalez Sofía , Lescano María Natalia , Oddi Facundo
Published: August 2013

Fire severity influences the recovery and biodiversity of plant communities. We compared the early post-fire recovery of plant functional groups in two sites (one burnt with high severity and one with low severity) in the north-western Patagonian steppe. We sampled the post-fire soil seed banks, as well as the composition and cover of aboveground plant species, and calculated richness, diversity and the percentage of exotic species. Low fire severity increased the diversity of aboveground vegetation and seed banks, whereas high fire severity reduced the cover of all functional groups, with the exception of fugitive species. Tiller production of perennial grasses decreased due to bud bank mortality. In the seed bank, high severity fire reduced fugitive species and increased exotic species. Fugitive species need fire to recruit, and the combination of fire cues and post-fire environmental conditions can explain the high abundance of these species after fire. In Patagonia, the use of fire is not considered a management option because fires are believed to be dangerous to humans, goods and services. However, north-western Patagonia is sparsely populated and the frequent wildfires pose no danger. It is necessary to increase the knowledge of the ecological processes of Patagonian ecosystems related to fire regime and land use, to achieve a reasonable balance between sustainable use and conservation in this region.
Changes in the spectral features of fuel layers of an Australian dry sclerophyll forest in response to prescribed burning
Authors: Gupta V. , Reinke K. , Jones S.
Published: August 2013

Prescribed burning is a landscape management tool often used for asset protection and ecological maintenance. Accordingly, there is a need to understand the effects fire has on the landscape and how these changes might be measured. Remote sensing pre- and post-burn has the potential to inform decisions about burn severity and ecosystem sensitivity to fire. The aim of this research was to identify changes in the electromagnetic radiation (EMR) following a prescribed burn in the fuel layers of an Australian dry sclerophyll forest using a hyperspectral radiometer (HSR). Results indicated three major changes in spectral features (1) absence of the green reflectance peak (550nm), (2) flattening or absence of red edge (680–750nm) and (3) disappearance of water absorption feature (970nm). The greatest difference in the intensity and shape of spectral signatures from pre-burn levels for all the targets occurred within the first 2 weeks post-burn. The trend of a return to the pre-burn spectral signature was seen to occur from week 5 onwards for most targets. These findings have important implications for identifying suitable remote sensing parameters for monitoring the effects of fire on vegetation.
Bringing values and deliberation to science communication
Authors: Dietz Thomas
Published: August 2013

Decisions always involve both facts and values, whereas most science communication focuses only on facts. If science communication is intended to inform decisions, it must be competent with regard to both facts and values. Public participation inevitably involves both facts and values. Research on public participation suggests that linking scientific analysis to public deliberation in an iterative process can help decision making deal effectively with both facts and values. Thus, linked analysis and deliberation can be an effective tool for science communication. However, challenges remain in conducting such process at the national and global scales, in enhancing trust, and in reconciling diverse values.
An integrated model of communication influence on beliefs
Authors: Eveland William P. , Cooper Kathryn E.
Published: August 2013

How do people develop and maintain their beliefs about science? Decades of social science research exist to help us answer this question. The Integrated Model of Communication Influence on Beliefs presented here combines multiple theories that have considered aspects of this process into a comprehensive model to explain how individuals arrive at their scientific beliefs. In this article, we (
i
) summarize what is known about how science is presented in various news and entertainment media forms; (
ii
) describe how individuals differ in their choices to be exposed to various forms and sources of communication; (
iii
) discuss the implications of how individuals mentally process information on the effects of communication; (
iv
) consider how communication effects can be altered depending on background characteristics and motivations of individuals; and (
v
) emphasize that the process of belief formation is not unidirectional but rather, feeds back on itself over time. We conclude by applying the Integrated Model of Communication Influence on Beliefs to the complex issue of beliefs about climate change.
New media landscapes and the science information consumer
Authors: Brossard Dominique
Published: August 2013

Individuals are increasingly turning to online environments to find information about science and to follow scientific developments. It is therefore crucial for scientists and scientific institutions to consider empirical findings from research in online science communication when thinking about science in the public sphere. After providing a snapshot of the current media landscape, this paper reviews recent major research findings related to science communication in the online environment and their implications for science in the 21st century. Particular emphasis is given to the bias introduced by search engines, the nature of scientific content encountered online, and the potential impact of the Internet on audiences’ knowledge and attitudes toward science.
In vivo genetic dissection of O2-evoked cGMP dynamics in aCaenorhabditis elegansgas sensor
Authors: Couto Africa , Oda Shigekazu , Nikolaev Viacheslav O. , Soltesz Zoltan , de Bono Mario
Published: August 2013

Significance

Although cGMP is a prominent second messenger in neurons, it has proven difficult to follow its dynamics in an intact nervous system in real time. Here, we use a genetically encoded cGMP sensor, cGi500, to visualize and genetically dissect endogenous cGMP dynamics in vivo. As a model, we use aCaenorhabditis elegansO2-sensing neuron. We uncover mutually regulating negative feedback mechanisms mediated by cGMP and Ca2+that involve PDE-1 and PDE-2 phosphodiesterases, protein kinase G, and cyclic nucleotide-gated channels. By simultaneously imaging Ca2+and cGMP, we provide evidence of compartmentalization of cGMP signaling in different cellular domains.
CD8 memory T cells have a bioenergetic advantage that underlies their rapid recall ability
Authors: van der Windt Gerritje J. W. , O’Sullivan David , Everts Bart , Huang Stanley Ching-Cheng , Buck Michael D. , Curtis Jonathan D. , Chang Chih-Hao , Smith Amber M. , Ai Teresa , Faubert Brandon , Jones Russell G. , Pearce Edward J. , Pearce Erika L.
Published: August 2013

A characteristic of memory T (TM) cells is their ability to mount faster and stronger responses to reinfection than naïve T (TN) cells do in response to an initial infection. However, the mechanisms that allow this rapid recall are not completely understood. We found that CD8 TMcells have more mitochondrial mass than CD8 TNcells and, that upon activation, the resulting secondary effector T (TE) cells proliferate more quickly, produce more cytokines, and maintain greater ATP levels than primary effector T cells. We also found that after activation, TMcells increase oxidative phosphorylation and aerobic glycolysis and sustain this increase to a greater extent than TNcells, suggesting that greater mitochondrial mass in TMcells not only promotes oxidative capacity, but also glycolytic capacity. We show that mitochondrial ATP is essential for the rapid induction of glycolysis in response to activation and the initiation of proliferation of both TNand TMcells. We also found that fatty acid oxidation is needed for TMcells to rapidly respond upon restimulation. Finally, we show that dissociation of the glycolysis enzyme hexokinase from mitochondria impairs proliferation and blocks the rapid induction of glycolysis upon T-cell receptor stimulation in TMcells. Our results demonstrate that greater mitochondrial mass endows TMcells with a bioenergetic advantage that underlies their ability to rapidly recall in response to reinfection.
DNA motifs determining the efficiency of adaptation into the
Escherichia coli
CRISPR array
Authors: Yosef Ido , Shitrit Dror , Goren Moran G. , Burstein David , Pupko Tal , Qimron Udi
Published: August 2013

Clustered regularly interspaced short palindromic repeats (CRISPR) and their associated proteins constitute a recently identified prokaryotic defense system against invading nucleic acids. DNA segments, termed protospacers, are integrated into the CRISPR array in a process called adaptation. Here, we establish a PCR-based assay that enables evaluating the adaptation efficiency of specific spacers into the type I-E
Escherichia coli
CRISPR array. Using this assay, we provide direct evidence that the protospacer adjacent motif along with the first base of the protospacer (5′-AAG) partially affect the efficiency of spacer acquisition. Remarkably, we identified a unique dinucleotide, 5′-AA, positioned at the 3′ end of the spacer, that enhances efficiency of the spacer's acquisition. Insertion of this dinucleotide increased acquisition efficiency of two different spacers. DNA sequencing of newly adapted CRISPR arrays revealed that the position of the newly identified motif with respect to the 5′-AAG is important for affecting acquisition efficiency. Analysis of approximately 1 million spacers showed that this motif is overrepresented in frequently acquired spacers compared with those acquired rarely. Our results represent an example of a short nonprotospacer adjacent motif sequence that affects acquisition efficiency and suggest that other as yet unknown motifs affect acquisition efficiency in other CRISPR systems as well.