bluuebunny/crossref_metadata_2025 huggingface dataset:
Line broadening of confined CO gas: From molecule-wall to molecule-molecule collisions with pressure
Authors: Hartmann J.-M. , Boulet C. , Auwera J. Vander , El Hamzaoui H. , Capoen B. , Bouazaoui M.
Published: February 2014

The infrared absorption in the fundamental band of CO gas confined in porous silica xerogel has been recorded at room temperature for pressures between about 5 and 920 hPa using a high resolution Fourier transform spectrometer. The widths of individual lines are determined from fits of measured spectra and compared with ab initio predictions obtained from requantized classical molecular dynamics simulations. Good agreement is obtained from the low pressure regime where the line shapes are governed by molecule-wall collisions to high pressures where the influence of molecule-molecule interactions dominates. These results, together with those obtained with a simple analytical model, indicate that both mechanisms contribute in a practically additive way to the observed linewidths. They also confirm that a single collision of a molecule with a wall changes its rotational state. These results are of interest for the determination of some characteristics of the opened porosity of porous materials through optical soundings.
High speed electric motors based on high performance novel soft magnets
Authors: Silveyra J. M. , Leary A. M. , DeGeorge V. , Simizu S. , McHenry M. E.
Published: February 2014

Novel Co-based soft magnetic materials are presented as a potential substitute for electrical steels in high speed motors for current industry applications. The low losses, high permeabilities, and good mechanical strength of these materials enable application in high rotational speed induction machines. Here, we present a finite element analysis of Parallel Path Magnetic Technology rotating motors constructed with both silicon steel and Co-based nanocomposite. The later achieved a 70% size reduction and an 83% reduction on NdFeB magnet volume with respect to a similar Si-steel design.
Broadband nanoelectromechanical phase shifting of light on a chip
Authors: Poot M. , Tang H. X.
Published: February 2014

We demonstrate an optomechanical phase shifter. By electrostatically deflecting the nanofabricated mechanical structure, the effective index of a nearby waveguide is changed and the resulting phase shift is measured using an integrated Mach-Zehnder interferometer. Comparing to thermo-optical phase shifters, our device does not consume power in static operation and also it can operate over large frequency, wavelength, and power ranges. Operation in the MHz range and sub-μs pulses is demonstrated.
Fermi-level depinning and contact resistance reduction in metal/n-Ge junctions by insertion of W-encapsulating Si cluster films
Authors: Okada Naoya , Uchida Noriyuki , Kanayama Toshihiko
Published: February 2014

We demonstrate Fermi-level depinning in metal/Ge junctions and a significant reduction of specific contact resistivity of n-Ge by inserting an ultra-thin semiconducting Si-rich W silicide film (WSin, n = 12–14) composed of W-encapsulating Si clusters. Dependence of the specific contact resistivity on the electron Schottky barrier height followed the ideal exponential relation for various contact metal species. This result indicates that the insertion of the WSin film provides a negligible contribution to contact resistivity because its tunneling resistance is very low owing to the low offset of the conduction band edge of Ge.
Switching mechanism of double forming process phenomenon in ZrOx/HfOy bilayer resistive switching memory structure with large endurance
Authors: Huang Chun-Yang , Huang Chung-Yu , Tsai Tsung-Ling , Lin Chun-An , Tseng Tseung-Yuen
Published: February 2014

In this Letter, the mechanism of double forming process phenomenon revealing in ZrO2/HfO2 bilayer resistive random access memory structure is investigated. This phenomenon caused by the formation of TiON interfacial layer can be well explained by using the energy band diagram. The TiON interfacial layer will be a tunneling barrier during the first forming process when a negative voltage applied on the device, while it will breakdown when applying a positive voltage. Besides, due to the double forming process, an asymmetric conductive filament with narrower size at ZrO2/HfO2 interface is formed in the device. The point for formation and rupture of the conductive filament can be confined at the ZrO2/HfO2 interface, and it will suppress the consumption of oxygen ions during endurance test. Therefore, high speed (40 ns) and large endurance (107 cycles) characteristics are achieved in this device structure.
Spin-orbit torque opposing the Oersted torque in ultrathin Co/Pt bilayers
Authors: Skinner T. D. , Wang M. , Hindmarch A. T. , Rushforth A. W. , Irvine A. C. , Heiss D. , Kurebayashi H. , Ferguson A. J.
Published: February 2014

Current-induced torques in ultrathin Co/Pt bilayers were investigated using an electrically driven ferromagnetic resonance technique. The angle dependence of the resonances, detected by a rectification effect as a voltage, was analysed to determine the symmetries and relative magnitudes of the spin-orbit torques. Both anti-damping (Slonczewski) and field-like torques were observed. As the ferromagnet thickness was reduced from 3 to 1 nm, the sign of the sum of the field-like torque and Oersted torque reversed. This observation is consistent with the emergence of a Rashba spin orbit torque in ultra-thin bilayers.
Flip-chip bonding of vertical-cavity surface-emitting lasers using laser-induced forward transfer
Authors: Kaur K. S. , Missinne J. , Van Steenberge G.
Published: February 2014

This letter reports the use of the Laser-Induced Forward Transfer (LIFT) technique for the fabrication of indium micro-bumps for the flip-chip (FC) bonding of single vertical-cavity surface-emitting laser chips. The FC bonded chips were electrically and optically characterized, and the successful functioning of the devices post-bonding is demonstrated. The die shear and life-time tests carried out on the bonded chips confirmed the mechanical reliability of the LIFT-assisted FC bonded assemblies.
Post-deposition processing options for high-efficiency sputtered CdS/CdTe solar cells
Authors: Paudel Naba R. , Young Matthew , Roland Paul J. , Ellingson Randy J. , Yan Yanfa , Compaan Alvin D.
Published: February 2014

CdCl2 activation near 400 °C is known to be critically important for obtaining high efficiency CdS/CdTe solar cells. However, this treatment step behaves differently on high-temperature-grown CdTe than on lower-temperature-grown CdTe layers such as those grown by sputtering. On sputtered films, the post-deposition activation produces grain-boundary passivation, sulfur diffusion into CdTe, and substantial grain growth. Nevertheless, we find the CdCl2 process for sputtered films to be characterized by a single activation energy that we interpret as applying to S diffusion into CdTe. We find this activation energy to hold for CdCl2 treatments from 370 to 440 °C. The completed CdS/CdTe solar-cell structures showed somewhat poorer initial performance with activation above 420 °C, but, in this case, the cell efficiency increased after accelerated life testing at 85 °C, open-circuit biasing and one-sun illumination. With an optimized CdCl2 activation process, the use of oxygenated sputtered CdS, and low-iron soda-lime glass, cell efficiencies of 14.5% were achieved.
Magnetic behavior of LaMn2(Si(1−x)Gex)2 compounds characterized by magnetic hyperfine field measurements
Authors: Bosch-Santos B. , Carbonari A. W. , Cabrera-Pasca G. A. , Saxena R. N.
Published: February 2014

The temperature dependence of the magnetic hyperfine field (Bhf) at Mn atom sites was measured in LaMn2(Si(1−x)Gex)2, with 0 ≤ x ≤ 1, compounds with perturbed γ−γ angular correlation spectroscopy using 111In(111Cd) as probe nuclei in the temperature range from 20 K to 480 K. The results show a transition from antiferromagnetic to ferromagnetic ordering for all studied compounds when Ge gradually replaces Si and allowed an accurate determination of the Néel temperature (TN) for each compound. It was observed that TN decreases when Ge concentration increases. Conversely, the Curie temperature increases with increase of Ge concentration. This remarkable change in the behavior of the transition temperatures is discussed in terms of the Mn-Mn distance and ascribed to a change in the exchange constant Jex.
Inkjet printed ambipolar transistors and inverters based on carbon nanotube/zinc tin oxide heterostructures
Authors: Kim Bongjun , Jang Seonpil , Geier Michael L. , Prabhumirashi Pradyumna L. , Hersam Mark C. , Dodabalapur Ananth
Published: February 2014

We report ambipolar field-effect transistors (FETs) consisting of inkjet printed semiconductor bilayer heterostructures utilizing semiconducting single-walled carbon nanotubes (SWCNTs) and amorphous zinc tin oxide (ZTO). The bilayer structure allows for electron transport to occur principally in the amorphous oxide layer and hole transport to occur exclusively in the SWCNT layer. This results in balanced electron and hole mobilities exceeding 2 cm2 V−1 s−1 at low operating voltages (<5 V) in air. We further show that the SWCNT-ZTO hybrid ambipolar FETs can be integrated into functional inverter circuits that display high peak gain (>10). This work provides a pathway for realizing solution processable, inkjet printable, large area electronic devices, and systems based on SWCNT-amorphous oxide heterostructures.
Electrical detection of picosecond acoustic pulses in vertical transport devices with nanowires
Authors: Young E. S. K. , Bouravleuv A. D. , Cirlin G. E. , Dhaka V. , Lipsanen H. , Tchernycheva M. , Scherbakov A. V. , Platonov A. V. , Akimov A. V. , Kent A. J.
Published: February 2014

Picosecond acoustic pulses, generated in a thin aluminum transducer, are injected into semiconductor vertical transport devices consisting of core-shell GaAsP nanowires. The acoustic pulses induce current pulses in the device with amplitude ∼1 μA. The spectrum of the electrical response is sensitive to the elastic properties of the device and has a frequency cutoff at ∼10 GHz. This work shows the potential of the technique for studies the elastic properties of complex semiconductor nanodevices.
Magnetic coupling in asymmetric FeCoV/Ru/FeNi trilayers
Authors: Wei Yajun , Jana Somnath , Brucas Rimantas , Pogoryelov Yevgen , Ranjbar Mojtaba , Dumas Randy K. , Warnicke Peter , Åkerman Johan , Arena Dario A. , Karis Olof , Svedlindh Peter
Published: February 2014

We have investigated the magnetic anisotropy and interlayer coupling in trilayer films of permendur(100 Å)/Ru/permalloy(100 Å), with the thickness of the Ru spacer varying from 0 to 200 Å. While the permendur/permalloy sample exhibits a small in-plane uniaxial magnetic anisotropy with Hu = 27 Oe, all trilayers are magnetically isotropic in-plane. Results from hysteresis loop and ferromagnetic resonance measurements were fitted to a micromagnetic model, with the results indicating that all the films are ferromagnetically coupled except the one with 10 Å Ru spacer, which shows antiferromagnetic coupling. The trilayers with Ru spacer layer thickness larger than 20 Å exhibit only very weak ferromagnetic coupling.
Nanofocusing of longitudinally polarized light using absorbance modulation
Authors: Li Qiang , Zhao Xing , Zhang Bo , Zheng Yi , Zhou Liqiu , Wang Lingjie , Wu Yanxiong , Fang Zhiliang
Published: February 2014

Recently, many methods based on amplitude or phase modulation to reduce the focal spot and enhance the longitudinal field component of a tight-focused radially polarized light beam have been suggested. But they all suffer from spot size limit 0.36λ/NA and large side lobes strength in longitudinal component. Here, we report a method of generating a tighter focused spot by focusing radially polarized and azimuthally polarized beams of different wavelengths on a thin photochromic film through a high-numerical-aperture lens simultaneously. In this method, by suppressing the radial component and compressing the longitudinal component of radially polarized beam, absorbance modulation makes the ultimate spot size break the size limit of 0.36λ/NA with side-lobe intensity of longitudinal component below 1% of central-peak intensity. The theoretical analysis and simulation demonstrate that the focal spot size could be smaller than 0.1λ with nearly all radial component blocked at high intensity ratio of the two illuminating beams.
Unusual defect physics in CH3NH3PbI3 perovskite solar cell absorber
Authors: Yin Wan-Jian , Shi Tingting , Yan Yanfa
Published: February 2014

Thin-film solar cells based on Methylammonium triiodideplumbate (CH3NH3PbI3) halide perovskites have recently shown remarkable performance. First-principle calculations show that CH3NH3PbI3 has unusual defect physics: (i) Different from common p-type thin-film solar cell absorbers, it exhibits flexible conductivity from good p-type, intrinsic to good n-type depending on the growth conditions; (ii) Dominant intrinsic defects create only shallow levels, which partially explain the long electron-hole diffusion length and high open-circuit voltage in solar cell. The unusual defect properties can be attributed to the strong Pb lone-pair s orbital and I p orbital antibonding coupling and the high ionicity of CH3NH3PbI3.
Properties of GaN grown on Si(111) substrates dependent on the thickness of 3C-SiC intermediate layers
Authors: Fang H. , Katagiri M. , Miyake H. , Hiramatsu K. , Oku H. , Asamura H. , Kawamura K.
Published: February 2014

Crack-free GaN epilayers were grown with the mask less epitaxial lateral overgrowth (ELO) on Si substrates with various thicknesses of 3C-SiC intermediate layers. The defects in 3C-SiC and GaN layers were studied to reveal the impact of 3C-SiC intermediate layer on GaN epitaxy. In the 3C-SiC layer, a gradient density of stacking faults (SFs) was observed along the growth direction. Most of the SFs locate in the first 500-nm-thick 3C-SiC layer. Thanks to the maskless ELO method, the defects in under layer could not extend into GaN layer, even grown on a 100-nm-thick 3C-SiC layer with high density. The threading dislocation density in GaN varies in the range of ∼(1 ± 0.3) × 109 cm−2. Investigation of GaN nucleation indicated a correlation between GaN quality and surface roughness of 3C-SiC layers. Meanwhile, the surface morphology of 3C-SiC is affected by double positioning domains, which revealed as a result of strain relaxation process during growth on Si substrate.
Note: Electrical detection and quantification of spin rectification effect enabled by shorted microstrip transmission line technique
Authors: Soh Wee Tee , Peng Bin , Chai Guozhi , Ong C. K.
Published: February 2014

We describe a shorted microstrip method for the sensitive quantification of Spin Rectification Effect (SRE). SRE for a Permalloy (Ni80Fe20) thin film strip sputtered onto SiO2 substrate is demonstrated. Our method obviates the need for simultaneous lithographic patterning of the sample and transmission line, therefore greatly simplifying the SRE measurement process. Such a shorted microstrip method can allow different contributions to SRE (anisotropic magnetoresistance, Hall effect, and anomalous Hall effect) to be simultaneously determined. Furthermore, SRE signals from unpatterned 50 nm thick Permalloy films of area dimensions 5 mm × 10 mm can even be detected.
Nano-optical observation of cascade switching in a parallel superconducting nanowire single photon detector
Authors: Heath Robert M. , Tanner Michael G. , Casaburi Alessandro , Webster Mark G. , San Emeterio Alvarez Lara , Jiang Weitao , Barber Zoe H. , Warburton Richard J. , Hadfield Robert H.
Published: February 2014

The device physics of parallel-wire superconducting nanowire single photon detectors is based on a cascade process. Using nano-optical techniques and a parallel wire device with spatially separate pixels, we explicitly demonstrate the single- and multi-photon triggering regimes. We develop a model for describing efficiency of a detector operating in the arm-trigger regime. We investigate the timing response of the detector when illuminating a single pixel and two pixels. We see a change in the active area of the detector between the two regimes and find the two-pixel trigger regime to have a faster timing response than the one-pixel regime.
Electromagnetic properties of Fe-Si-Al/BaTiO3/Nd2Fe14B particulate composites at microwave frequencies
Authors: Wang Xian , Xu Xiaojun , Gong Wei , Feng Zekun , Gong Rongzhou
Published: February 2014

Ferroelectric/ferromagnetic (soft and hard) three-phase microwave absorption composites, consisting of Fe-Si-Al/BaTiO3/Nd2Fe14B, are presented, which were fabricated by mechanical ball milling. The microstructure, magnetic, and microwave properties were measured, demonstrating significant improvement in magnetization and coercivity, compared to those single phase materials. In particular, either ferroelectric or hard magnetic phase presents a strong tunability of permeability and permittivity with frequency, which can tailor a frequency band of microwave absorption. The experiments indicate that an optimal reflection loss of the Fe-Si-Al/BaTiO3/Nd2Fe14B was tuned from 2 to 9.52 GHz, whereas the peak value was remarkably enhanced by 62.8%. Therefore, the three-phase microwave absorption composites may remain thin but have great potential to be used at high frequency range.
Ultrafast optical properties of lithographically defined quantum dot amplifiers
Authors: Miaja-Avila L. , Verma V. B. , Coleman J. J. , Mirin R. P. , Silverman K. L.
Published: February 2014

We measure the ultrafast optical response of lithographically defined quantum dot amplifiers at 40 K. Recovery of the gain mostly occurs in less than 1 picosecond, with some longer-term transients attributable to carrier heating. Recovery of the absorption proceeds on a much longer timescale, representative of relaxation between quantum dot levels and carrier recombination. We also measure transparency current-density in these devices.
Parallel laser fabrication of film-embedded microstructures using reusable functionalized template
Authors: Kang Bongchul , Deb Nath S. K. , Kim Hyun-Chul , Kim Sung-Gaun
Published: February 2014

This study proposes a new parallel mass-production method for obtaining microstructures embedded in flexible films, utilizing a laser-processed reusable functionalized template and a laser-induced adhesive transfer. This physical shape-free template can be cost-effectively fabricated by means of the laser-induced plasmonic defunctionalization of a self-assembled monolayer. The resulting metal nanoparticle microstructure, deposited self-selectively on the template, is transferred to a flexible film by a photo-induced instantaneous interfacial adhesion film in parallel; this process being optimized using molecular dynamics simulations. This method is demonstrated to be capable of the high-efficiency and eco-friendly production of high resolution and durable microstructures in flexible films, using a reusable template to eliminate material waste. Moreover, key design parameters such as the resolution, thickness, type, and shape of microstructures can be actively changed.
Large E-field tunability of microwave ferromagnetic properties in Fe59.3Co28.0Hf12.7/PZN-PT multiferroic composites
Authors: Li Shandong , Du Honglei , Xue Qian , Gao Xiaoyang , Zhang Yongcheng , Shao Weiquan , Nan Tianxiang , Zhou Ziyao , Sun Nian X.
Published: February 2014

Strong converse magnetoelectric coupling was observed in a multiferroic heterostructure of Fe59.3Co28.0Hf12.7 film on (011) cut lead zinc niobate-lead titanate (PZN-PT) slab, which exhibited a large electric field (E-field) tunability of microwave magnetic properties. With the increase of E-field from 0 to 6 kV/cm on PZN-PT, the ferromagnetic resonance (FMR) field Hr shifts downwards by 430.7 Oe along [011¯] direction and upwards by 492.9 Oe along [100] direction of the PZN-PT. Accordingly, the strong magnetoelectric coupling led to a significantly enhanced self-biased FMR frequency from 4.2 to 7.9 GHz under zero bias magnetic field, and the magnetic damping constant α was decreased from 0.0260 to 0.0185 at the same time. These features demonstrate that this multiferroic laminate is promising in fabrication of E-field tunable microwave components.
Schlieren characterization of gas flows generated by cathodic arcs in atmospheric pressure environment
Authors: Kronhaus I. , Eichler S. , Schein J.
Published: February 2014

Schlieren diagnostics of cathodic arc flows in air are presented. Three important processes are observed: (1) a luminous hemispherical region near the cathode with a radius of ≈1 mm, identified as the cathodic metallic plasma; (2) a luminous plasma jet extending ≈10 mm from the cathode, termed as the cathodic air jet (CAJ); (3) a background gas pushed to expand at subsonic velocities ≥100 m/s. The gas is accelerated in the direction of the CAJ. The main collisional processes in the CAJ are identified using optical emission spectroscopy and mean free path analysis. The CAJ plasma is shown to be composed of N2+ and Cu+ ions. It is concluded that the CAJ length is determined by the dissociative recombination of N2+. With external magnetic field, the CAJ rotates according to the Lorentz force direction. Observing the CAJ motion and its affect on stationary and flowing background gas, it is concluded that the CAJ has significant directed thrust.
The Creative Industries and Urban Economic Growth in the UK
Authors: Lee Neil
Published: February 2014

Policy makers in the UK see the creative industries as a key sector for regenerating inner cities and stimulating flagging urban economies. The creative industries may raise productivity through spillovers or as part of the production processes of other firms. Creative firms may squeeze out other, less productive sectors. Highly skilled workers may be attracted to creative cities. Or the creative industries may thrive in growing cities with strong demand for their products. This paper tests the link between the creative industries and wage and employment growth in a panel of travel-to-work areas from 2003 to 2008. The results suggest the creative industries drive both wage and employment growth in other sectors. However, when only urban areas are considered the creative industries drive wage growth but do not increase employment. These findings are consistent with the idea that the creative industries help other sectors grow, but may squeeze out declining industries from urban areas.
UK Biofuel Policy: Envisaging Sustainable Biofuels, Shaping Institutions and Futures
Authors: Levidow Les , Papaioannou Theo
Published: February 2014

Technoscientific innovation has played a central role in UK biofuel policy. When the government was proposing mandatory targets in 2007–08, public controversy over ‘unsustainable biofuels’ was channelled into prospects for future biofuels to avoid environmental harm and land-use conflicts. This vision serves as an imaginary—a feasible, desirable future. Societal benefits have been envisaged according to specific models of economic competitiveness, valuable knowledge, and environmental sustainability— together comprising a prevalent imaginary of future ‘sustainable biofuels’. This has informed institutional change along two lines. First, targets are envisaged as a temporary transition until future ‘advanced biofuels’ make liquid fuel more sustainable. Second, UK research institutes realign their priorities towards seeking investment from foreign counterparts and global energy companies, in the name of making UK science and industry more competitive. Together these measures have been justified as necessary for a transition to advanced biofuels which would better contribute to a low-carbon economy. Although this imaginary may eventually be transformed into reality, initially realised has been institutional change that reinforces infrastructural dependence on liquid fuel for the internal combustion engine. As an imaginary, then, ‘sustainable biofuels’ can help explain how a policy agenda promotes one future, while marginalising alternatives.
The Evolutionary Dynamics of Biofuel Value Chains: From Unipolar and Government-Driven to Multipolar Governance
Authors: Ponte Stefano
Published: February 2014

In this paper I propose to push the frontier of global value chain (GVC) governance analysis through the concept of ‘polarity’. Much of the existing GVC literature has focused on ‘unipolar’ value chains, where one group of ‘lead firms’ inhabiting a specific function in a chain plays a dominant role in governing it. Some scholars have explored the dynamics of governance in GVCs characterized as ‘bipolar’, where two sets of actors in different functional positions both drive the chain. I expand this direction further to suggest conceptualizing governance within a continuum between unipolarity and multipolarity Empirically, I do so by examining the evolutionary dynamics of governance in biofuel value chains, with specific focus on the key regulatory and institutional features that facilitated their emergence and expansion. First, I examine the formation, evolution, and governance of three national/regional value chains (in Brazil, the US, and the EU); then, I provide evidence to support a trend towards the increasing but still partial formation of a global biofuel value chain and examine its governance traits.
Science in Carbon Economies: Debating What Counts in US Biofuel Governance
Authors: Gillon Sean
Published: February 2014

This paper analyzes the scientific practices that constitute carbon economies by rendering carbon countable, fungible, and governable. Examining US biofuel governance, I draw on field research and document and policy analyses to consider the roles state, private industry, and civil society actors play in negotiating scientific practice in biofuel governance and to explore the geographically uneven consequences of contrasting science–society configurations. This research illustrates the complex and contradictory roles of nature's quantification and state-supported science in carbon economies. Although nature's quantification as carbon was initially used as a technology of opposition and accountability to limit vested interest power and maintain biofuels' greenhouse gas reduction capacity, it ultimately served industry interests by focusing policy deliberation on technical issues industry deftly navigated and away from policy rationale, value conflict, and biofuels' broader social–ecological consequences. Drawing attention to state-supported environmental risk assessment and place-based approaches to integrating science and agriculture, this research describes multiple, conflicting modes of state scientific practice and emphasizes the importance of considering multiple scientific perspectives in climate change research and intervention. I argue that, rather than focusing on mitigating climate change through universal, carbon-focused science alone, future science–society configurations should include efforts to build institutional capacity for transformation and adaptation to confront uneven and changing social–ecological circumstances using site-specific scientific knowledge.
Biofuels and the Politics of Land-Use Change: Tracing the Interactions of Discourse and Place in European Policy Making
Authors: Palmer James R
Published: February 2014

Whilst transport biofuels have enjoyed strong political support in Europe for much of the past decade, concerns over their full impacts have an almost equally long history. Since 2008 these concerns have centred most intently upon the land-use change impacts of biofuel production, whereby increased demand for biofuels leads nonagricultural landscapes to be converted—either directly or indirectly—into agricultural ones. Amongst other things, biofuel-driven land-use change might potentially lead to significant emissions of greenhouse gases (GHG), losses of biodiversity, reduced ecosystem resilience, degradation of soil and water resources, declines in regional food security, or even land rights infringements through so-called ‘land-grabbing’. Political debates surrounding biofuel-driven land-use change in Europe have historically been restricted, however, to considerations of technical modelling work addressing the GHG emissions that might result from this process, thereby ignoring a wide range of alternative issues. Adopting a discursive-institutionalist perspective, this paper scrutinises two interrelated sets of dynamics pertaining to the handling of this political issue in Europe. First, it examines how the specific bureaucratic context of Brussels has itself been constitutive of the discursive practices used by policy makers to establish and retain control of the prevailing political conception of biofuel-driven land-use change. Second, it examines how these practices have inevitably led to what Scott terms a “narrowing of vision” in policy makers' approach to this problem, with concomitant implications for the role occupied by conceptions of ‘place’ in the policy process. In both instances the argument is made that such interactions exclude critical perspectives on what is at stake in the drive for biofuels from relevant policy-making procedures altogether. In light of these conclusions, I contend that future geographical analyses of environmental policy making writ large should pay greater attention to the interactions of discourse and place, particularly if they are to better understand the precise mechanisms through which political controversy is ultimately managed and settled in modern democratic contexts today.
Hegel's Geographical Thought
Authors: Bond Dean W
Published: February 2014

This paper sketches out the contours of the philosopher G W F Hegel's geographical thought. Until now, geographers have shown little interest in Hegel's geographical writing. He has figured minimally in histories of geography, and critical geographers who have engaged with Hegel have done so indirectly, either through Karl Marx's work or through Marxist and postcolonial scholars' readings of Hegel. This paper offers a more direct reading. It begins from an understanding of geographical thought as both an intellectual and a practical endeavor with its own distinct historical geographies. It examines Hegel's concepts of ‘nature’ ( Natur) and ‘space’ ( Raum); his understanding of geography's relationship to history and anthropology; his relationship to Carl Ritter and Alexander von Humboldt; and the significance of ‘territory’ in his political philosophy. It highlights the ambiguity that characterized Hegel's thinking about geography, especially in his discussion of climate's influence on humans. It also challenges Henri Lefebvre's reading of Hegel's view on the state's relationship to territory. Finally, it suggests that Hegel's conceptions of nature, space, and geography mattered not only for his philosophies of history, nature, and subjective spirit, but for his understanding of modernity's geographies as well.
The Sydney Metropolitan Strategy as a Zoning Technology: Analyzing the Spatial and Temporal Dimensions of Obsolescence
Authors: Rogers Dallas
Published: February 2014

This paper provides two discrete contributions to urban and spatial theory. The first demonstrates that within discourse analysis conceptions of time and space have analytical utility for investigations into the framings of social and urban policy. The second moves analyses of urban obsolescence beyond Marxism to demonstrate that Foucauldian theory can provide revealing insights about the stewardship of discourses of urban obsolescence through texts and visual images created by different social actors. On the basis of these two contributions I demonstrate how the Sydney metropolitan planning authority has deployed specific spatial and temporal ‘zoning technologies’ to demarcate and evaluate sections of the city. The discourses of obsolescence that have emerged in Sydney are clearly informed by market-centric ideology and discursively constructed, not in the presence of an anemic state and a rational market, but as a technology of power that is deployed by the state and serves the interests of powerful market actors. I conclude that this discursive process is leading to the demise of Sydney's public housing estates.
Effects of low protein diets on performance of pigs with a lean genotype between 40 and 115 kg liveweight
Authors: Bunger L. , Lambe N. R. , McLean K. , Cesaro G. , Walling G. A. , Whitney H. , Jagger S. , Fullarton P. , Maltin C. A. , Wood J. D.
Published: February 2014

The aim of the work was to assess the effects of three dietary protein regimes on pig performance and nitrogen (N) excretion, in particular, whether performance can be maintained in lean, fast growing pigs when protein levels are reduced to limit N excretion. Entire male pigs of a lean genotype (Pietrain × Large White × Landrace), 192 in total in four batches, were grown from 40 to 115 kg in pens with four pigs per pen. The diets were: (i) a high-protein control regime; (ii) a low-protein regime in which protein was reduced by ~2 percentage units in each growth stage, but with levels of five essential amino acids the same as in the control (LP1); (iii) an even lower protein regime in which levels of essential amino acids were not maintained beyond 60 kg (LP2). The LP2 regime was designed to promote intramuscular fat deposition rather than efficient growth. Excretion of N was reduced by 17% and 19% in LP1 and LP2, respectively, compared with the control. Average daily gain was lower and feed conversion ratio higher in LP2 than the other regimes, as expected. The control and LP1, which differed in protein but not essential amino acid levels, produced broadly similar results for performance, but pigs in LP1 had poorer feed conversion than control pigs, which could be due to slightly greater fat deposition. The results show the difficulty in maintaining consistently high levels of performance in fast-growing, lean pigs when dietary protein levels are reduced.
Correlated morphological and genetic patterns in Embothrium coccineum (Proteaceae) across climate and geography: can Embothrium survive patagonian climate change?
Authors: Souto Cintia P. , Smouse Peter E.
Published: February 2014

Adaptive radiation and reproductive isolation can determine the biogeographic structure of any species. We examine patterns of biotic variation in Embothrium coccineum, a Proteaceae tree that spans 20° of latitude and is both morphologically and genetically highly variable. We aim to (1) explore the correspondence between these biotic patterns and current geographic and climatic gradients, and (2) determine whether and how those patterns are likely to respond to changing climate. We conducted separate principal component analyses on biotic and abiotic sets of variables for 34 populations of Embothrium coccineum, accounting for a large fraction of the total variation in each. We then used canonical correlation analyses to optimise the match of those gradients onto each other. Smaller, rounder leaves and particular alleles typify the colder and drier parts of the range, whereas larger, lanceolate leaves and other alleles typify warmer and moister areas. Finally, we mapped biotic profiles onto a predicted climatic landscape, on the basis of doubling of CO2 projections. The climatic regime is predicted to shift geographically, but this lineage has successfully responded to repeated and dramatic climatic shifts since the Oligocene, and it should also be able to move and adapt quickly enough to meet the present challenge. More generally, our analytic approach can be extended to analysis of biotic and abiotic patterns in other species facing climatic challenges. Where there is enough biogeographic variation to provide adaptively relevant substrate, and where propagule dispersal is sufficiently extensive to keep up with the pace of spatial climatic shift, such taxa should be able to cope with shifting climate.
Drought-induced mortality selectively affects Scots pine trees that show limited intrinsic water-use efficiency responsiveness to raising atmospheric CO2
Authors: Hereş Ana-Maria , Voltas Jordi , López Bernat Claramunt , Martínez-Vilalta Jordi
Published: February 2014

Widespread drought-induced tree mortality has been documented around the world, and could increase in frequency and intensity under warmer and drier conditions. Ecophysiological differences between dying and surviving trees might underlie predispositions to mortality, but are poorly documented. Here we report a study of Scots pines (Pinus sylvestris L.) from two sites located in north-eastern Iberian Peninsula where drought-associated mortality episodes were registered during the last few decades. Time trends of discrimination against 13C (Δ13C) and intrinsic water-use efficiency (WUEi) in tree rings at an annual resolution and for a 34 year period were used to compare co-occurring now-dead and surviving pines. Results indicate that both surviving and now-dead pines significantly increased their WUEi over time, although this increase was significantly lower for now-dead individuals. These differential WUEi trends corresponded to different scenarios describing how plant gas exchange responds to increasing atmospheric CO2 (Ca): the estimated intercellular CO2 concentration was nearly constant in surviving pines but tended to increase proportionally to Ca in now-dead trees. Concurrently, the WUEi increase was not paralleled by a growth enhancement, regardless of tree state, suggesting that in water-limited areas like the Mediterranean, it cannot overcome the impact of an increasingly warmer and drier climate on tree growth.
Polymorphisms in TOX and NCOA2 genes and their associations with reproductive traits in cattle
Authors: de Camargo Gregório M. F. , Costa Raphael B. , de Albuquerque Lucia G. , Regitano Luciana C. A. , Baldi Fernando , Tonhati Humberto
Published: February 2014

Reproductive traits are an important component of the economic selection index for beef cattle in the tropics. Phenotypic expression of these traits occurs late because they are measured when the animals reach reproductive age. Association studies using high-density markers have been conducted to identify genes that influence certain traits. The identification of causal mutations in these genes permits the inclusion of these single nucleotide polymorphisms (SNPs) in customised DNA chips to increase efficiency and validity. Therefore, the aim of the present study was to detect causal mutations in the TOX and NCOA2 genes, previously identified by genome-wide association studies of zebu cattle. DNA was extracted from 385 Nellore females and polymorphisms were investigated by polymerase chain reaction sequencing. Five polymorphisms were detected in the NCOA2 gene and four in the TOX gene that were associated with reproductive traits. Analysis of variance showed that SNP 1718 in the NCOA2 gene was significant for early pregnancy probability (P = 0.02) and age at first calving (P = 0.03), and SNP 2038 in the same gene was significant for days to calving (P = 0.03). Studies investigating polymorphisms in other regions of the gene and in other genes should be conducted to identify causal mutations.
Neuronal nonlinearity explains greater visual spatial resolution for darks than lights
Authors: Kremkow Jens , Jin Jianzhong , Komban Stanley J. , Wang Yushi , Lashgari Reza , Li Xiaobing , Jansen Michael , Zaidi Qasim , Alonso Jose-Manuel
Published: February 2014

Significance

Light and dark stimuli are separately processed by ON and OFF channels in retina and thalamus. Although most textbooks assume that ON and OFF visual responses are relatively balanced throughout the visual system, recent studies have identified a pronounced overrepresentation of OFF responses in the cerebral cortex. This recent discovery resonates with Galileo and Helmholtz’s pioneering observations that visual spatial resolution is higher for darks than lights. In this paper, we demonstrate that these two seemingly separate findings are related and caused by a pronounced difference between ON and OFF luminance response functions, which most likely originates in photoreceptors. Therefore, asymmetric ON and OFF neural responses provide the neurophysiological explanation for an almost four-century-old puzzle dating back to Galileo.
Block-Cell-Printing for live single-cell printing
Authors: Zhang Kai , Chou Chao-Kai , Xia Xiaofeng , Hung Mien-Chie , Qin Lidong
Published: February 2014

Significance

The ability of printing single-cell arrays with high precision and efficiency, single-cell resolution, multiple cell types, and maintenance of cell viability and function is essential for cell function and heterogeneity measurement. It is still hard for current methods to completely satisfy the above requirements. We report a unique live-cell printing technique, Block-Cell-Printing, that allows for convenient, precise, multiplexed, and high-throughput printing of functional single-cell arrays. Block-Cell-Printing has a minimum turnaround time of 0.5 h, a maximum resolution of 5 µm, and close to 100% cell viability. This method has been applied to study cell communications in heterotypic cell pairs with controlled morphology, characterize cells’ abilities to extend their membranes, and print primary neurons.
Nonflammable perfluoropolyether-based electrolytes for lithium batteries
Authors: Wong Dominica H. C. , Thelen Jacob L. , Fu Yanbao , Devaux Didier , Pandya Ashish A. , Battaglia Vincent S. , Balsara Nitash P. , DeSimone Joseph M.
Published: February 2014

Significance

This research article describes a unique class of nonflammable electrolytes for lithium-ion batteries that are based on functionalized perfluoropolyethers (PFPEs). It demonstrates that PFPEs may be used as a major component in operating batteries. These electrolytes not only are completely nonflammable, but they also exhibit unprecedented high transference numbers and low electrochemical polarization, indicative of longer battery life. The results in this work may represent a significant step toward a lithium-ion battery with improved safety and pave the way for the development of new electrolytes that can address the persisting challenges of current battery technologies.
Afforestation in China cools local land surface temperature
Authors: Peng Shu-Shi , Piao Shilong , Zeng Zhenzhong , Ciais Philippe , Zhou Liming , Li Laurent Z. X. , Myneni Ranga B. , Yin Yi , Zeng Hui
Published: February 2014

Significance

China has the largest afforested area in the world. Afforestation not only contributes to increased carbon storage but also alters local albedo and turbulent energy fluxes, which offers feedback on the local and regional climate. This study presents previously unidentified observational evidence of the effect of large-scale afforestation on land surface temperature (LST) in China. Afforestation decreases daytime LST, because of enhanced evapotranspiration, and increases nighttime LST. This nighttime warming tends to offset daytime cooling in dry regions. These results suggest it is necessary to carefully consider where to plant trees to achieve potential climatic benefits in future afforestation projects.
Transoceanic drift and the domestication of African bottle gourds in the Americas
Authors: Kistler Logan , Montenegro Álvaro , Smith Bruce D. , Gifford John A. , Green Richard E. , Newsom Lee A. , Shapiro Beth
Published: February 2014

Significance

Bottle gourd, one of the most cross-culturally ubiquitous crops, had a pan-tropical distribution by the beginning of the Holocene. Our findings overturn a major component of the current model for bottle gourd’s early global dispersal, specifically regarding how it entered the Americas. Our findings also indicate that the domestication process itself took place in a diffuse pattern throughout the bottle gourd’s New World range, explaining early and nearly contemporaneous use of bottle gourds in North, Central, and South America. Bottle gourd’s weedy growth habit and the diffuse domestication pattern also suggest that early cultivation were probably not restricted to known centers of domestication. It is likely, however, that domesticated phenotypes emerged in these centers alongside food crops.
The predictability of molecular evolution during functional innovation
Authors: Blank Diana , Wolf Luise , Ackermann Martin , Silander Olin K.
Published: February 2014

Significance

Understanding the genetic changes that underlie phenotypic functional innovations is a fundamental goal in evolutionary biology, giving insight into species’ past, present, and future evolutionary trajectories. One important unresolved question is whether such genetic changes typically affect protein expression or protein structure. Here we use large-scale laboratory evolution with bacteria to quantify the types of genetic changes that occur during functional innovation. We show that whether these changes affect protein expression or protein structure depends on which cellular functions are being selected upon. We then show that changes affecting protein expression occur in qualitatively different sets of genes from changes affecting protein structure. These results show that using functional knowledge it is possible to predict the course of evolution.
Inhibition of p53 preserves Parkin-mediated mitophagy and pancreatic β-cell function in diabetes
Authors: Hoshino Atsushi , Ariyoshi Makoto , Okawa Yoshifumi , Kaimoto Satoshi , Uchihashi Motoki , Fukai Kuniyoshi , Iwai-Kanai Eri , Ikeda Koji , Ueyama Tomomi , Ogata Takehiro , Matoba Satoaki
Published: February 2014

Significance

Tumor suppressor p53 has been known to have a broader role that extends to the regulation of energy metabolism. We investigated the role of islet p53 and found that genetic and pharmacological inhibition of p53 preserves insulin secretion and glucose tolerance in both streptozotocin-induced type 1 and
db/db
mouse models of type 2 diabetes. Glucolipotoxicy induces accumulation of p53 in the cytosol via oxidative stress and endoplasmic reticulum stress. Cytosolic p53 inhibits the autophagic clearance of damaged mitochondria by an inhibitory protein–protein interaction with Parkin, leading to the impairment of mitochondrial energetics and subsequent insulin secretion signals in islet β-cells.
PACAP receptor gene polymorphism impacts fear responses in the amygdala and hippocampus
Authors: Stevens Jennifer Strafford , Almli Lynn M. , Fani Negar , Gutman David A. , Bradley Bekh , Norrholm Seth D. , Reiser Emily , Ely Timothy D. , Dhanani Rahim , Glover Ebony M. , Jovanovic Tanja , Ressler Kerry J.
Published: February 2014

Significance

Higher circulating pituitary adenylate cyclase-activating polypeptide (PACAP) and a polymorphism in its receptor geneADCYAP1R1, adenylate cyclase activating polypeptide 1 receptor type 1, have recently been linked with posttraumatic stress disorder (PTSD) in women and not men. The current study examined the influence ofADCYAP1R1genotype on brain function among traumatized women. In individuals with the risk genotype, the amygdala showed greater reactivity to threat stimuli and decreased functional connectivity with the hippocampus.ADCYAP1R1genotype had larger effects than PTSD diagnosis, suggesting that amygdala reactivity is an intermediate phenotype for anxiety-related psychopathology. Amygdala reactivity has been identified as a possible predisposing risk factor for PTSD, and the current findings indicate a possible genetic mechanism. Findings also point to a neurobiological explanation for increased PTSD prevalence in women.