bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesising frontal face image using elastic net penalty and neighbourhood consistency prior
Authors: Hao Yuanhong , Qi Chun
Published: January 2015

Traditional frontal face image synthesis based on the ℓ1‐penalty has achieved remarkable success. However, the ℓ1‐penalty on reconstruction coefficients has the drawback of instability when processing high‐dimensional data (e.g. a facial image including hundreds of pixels). Moreover, the traditional ℓ1‐penalty‐based method requires consistency between the corresponding patches in frontal and profile faces, which is hard to guarantee due to self‐occlusion. To overcome the instability problem of the traditional method, an extension of the ℓ1‐penalty‐based frontal face synthesis method, which benefits from the nature of the elastic net, is presented. 3 addition, to enhance the aforementioned consistency, a neighbourhood consistency penalty is imposed onto the reconstruction coefficients using the connected neighbour patches of the current patch. Furthermore, to ensure the synthesised result faithfully approximates the ground truth, a sparse neighbour selection strategy is introduced for finding related neighbours adaptively. Experimental results demonstrate the superiority of the proposed method over some state‐of‐the‐art methods in both visual and quantitative comparisons.
3D imaging with single‐plane electrical capacitance tomography sensor
Authors: Sun Jiangtao , Ren Zhen , Yang Wuqiang
Published: January 2015

A single‐plane electrical capacitance tomography (ECT) sensor is usually used to visualise dielectric material distribution by providing two‐dimensional (2D) images. The imaging of a metallic object inside a dielectric material is reported and the feasibility of 3D imaging based on the fringe effect of a single‐plane ECT sensor is demonstrated. Experimental results are given.
Performance analysis of energy detector over η−μ fading channel: PDF‐based approach
Authors: Al‐Hmood H. , Al‐Raweshidy H.S.
Published: January 2015

The performance of an energy detector is analysed over an η − μ fading channel using the probability density function (PDF) of the received instantaneous signal‐to‐noise ratio. The η − μ is a generalised multipath fading channel that describes the non‐line‐of‐sight wireless communications scenario. Novel, general, exact and closed‐form analytic expressions for both average detection probability and the average area under the receiver operating characteristics curve are derived.
8b 0.9 V 300 MHz pipelined ADC using transistor healing and charge‐steering techniques
Authors: Moghadami S. , Ardalan S.
Published: January 2015

A fully integrated 0.9 V, 8b, 300 MHz pipelined analogue‐to‐digital converter (ADC) using healed transistors and charge‐steering op‐amps in 180 nm CMOS technology is presented. The proposed ADC employs the modified current‐driven bulk (CDB) method as a healing technique to reduce the threshold voltage (Vth) of transistors in order to improve the overall performance. The fabricated ADC achieves an SFDR of 59.1 dB and an SNDR of 42.9 dB while dissipating 2.56 mW from the 0.9 V power supply. These results yield an FOMW of 74.8 fJ/conversion step and an FOMS of 150.6 dB.
Very high‐sensitivity tunable phase detection of light power variations using electrical modulation of Si‐photodiode in photovoltaic regime
Authors: De Marcellis A. , Janneh M. , Palange E.
Published: January 2015

The use of a silicon (Si)‐photodiode (Si‐PD) operating in photovoltaic mode as a tunable very high‐sensitivity phase detector of light power variations is demonstrated. This result is reached by applying to the Si‐PD an electrical modulation through an AC excitation signal without a DC reverse bias. This allows employing the synchronous demodulation technique for phase detection that shows much better performances with respect to the conventional amplitude measurements, mainly overcoming the issues related to the electrical noise and the resolution limitation due to the selected full scale. The phase variations to be detected occur between the modulating signal and the one provided by the Si‐PD as a function of the light power variations on its sensitive area. The proposed approach notably simplifies both the electronic circuitry and the optical setup, minimising the detection system complexity and size. Experimental results demonstrate that it is possible to achieve phase detection sensitivity, with respect to light power variations, of up to 410°/μW as a function of the Si‐PD settable operating conditions. Using a standard commercial lock‐in amplifier with a 0.01° phase resolution is possible to obtain a light power resolution of up to 25 pW.
Energy efficiency‐based device‐to‐device uplink resource allocation with multiple resource reusing
Authors: Yang Chengcheng , Xu Xiaodong , Han Jiang , Tao Xiaofeng
Published: January 2015

Device‐to‐device communication fulfils its potential in terms of high resource utilisation, thus it has been a hot topic in the recent long‐term evolution standardisation process. The general scenario with multiple resource pool multiplexing instead of the one‐time reusing is considered. Meanwhile, the optimisation target focuses on device energy efficiency under certain system throughput insurance rather than the traditional system throughput. A modified genetic algorithm‐based scheme is applied to address the facing non‐deterministic polynomial‐time hard problem with higher convergence and lower complexity.
Broadband substrate‐integrated waveguide T‐junction with arbitrary power‐dividing ratio
Authors: Li Teng , Dou Wenbin
Published: January 2015

A novel broadband substrate‐integrated waveguide (SIW) T‐junction with an arbitrary power‐dividing ratio is proposed. Three inductive posts are designed to adopt flexibility for the equal output T‐junction to obtain a wide impedance bandwidth. To realise the unequal power‐dividing ratio over a wide bandwidth, the SIW coupler is integrated with corner structures and a novel T‐junction structure is formed. Three T‐junctions with different power division ratios (1:1, 1:4 and 1:8) at a centre frequency of 6 GHz are simulated, fabricated and measured. The measured bandwidths are 60, 53 and 63.3%, respectively.
Interferometric orbital angular momentum mode multiplexer/demultiplexer based on pairs of cylindrical lenses
Authors: Martelli P. , Boffi P. , Fasiello A. , Martinelli M.
Published: January 2015

A novel interferometric configuration for orbital angular momentum (OAM) mode multiplexing/demultiplexing, based on the image transformation property of pairs of cylindrical lenses and without any splitting loss, is proposed. The effectiveness in mode demultiplexing has been experimentally proven by performing bit error rate measurements for a 20 Gbit/s mode division multiplexing communication system where two modes with different values of OAM, corresponding to the angular indices l = 0 and 1, respectively, are transmitted.
Slew rate enhancement based on use of squaring circuits
Authors: Valero M.R. , Thoutam S. , Ramírez‐Angulo J. , Lopez‐Martín A. , Carvajal R.G.
Published: January 2015

A squaring circuit is introduced that boosts the tail current source of an opamp to improve its slew rate. It operates as a differential voltage magnitude detector, which generates opamp tail currents proportional to the magnitude (square) of the opamp's differential input voltage. Experimental results from a fabricated test chip verify current and slew rate enhancement between 900 and 1400% with respect to its initial value with <20% static current increase.
Wideband patch directional coupler based on non‐uniform mushroom structure
Authors: Zhou Xin Yu , Zheng Shao Yong , Pu Xing Yu , Chan Wing Shing , Long Yunliang
Published: January 2015

A wideband patch directional coupler is proposed. The coupler is designed based on the non‐uniform mushroom structure with unique characteristics. The current distribution within the patch can be controlled by the mushroom cells underneath for wideband property. An 8 dB directional coupler has been designed, fabricated and measured for verification. It exhibits good return loss, small coupling coefficient variation and quadrature phase difference among the output ports over a wide bandwidth of 74.6% centred at 8.45 GHz.
Tunable 500 GHz transmitter array in SiGe technology for gas spectroscopy
Authors: Schmalz K. , Borngräber J. , Debski W. , Neumaier P. , Wang R. , Hübers H.‐W.
Published: January 2015

A 500 GHz system for gas spectroscopy is presented, which includes an integrated SiGe 4 × 1 transmitter (TX) array, a Golay cell as a detector and a 1.9 m‐long gas absorption cell. The local oscillator (LO) of the TX array is controlled by an external phase‐locked loop, whose reference frequency is swept. The four TX branches involve frequency quadruplers (x4). The TX branches are fed by a 120 GHz power division network, which is connected to the LO. The estimated radiated output power of the TX array is −7 dBm at 500 GHz. The absorption spectrum of gaseous methanol is shown for 494–500 GHz.
Mutual dependency of features in multimodal biometric systems
Authors: Yang Wencheng , Hu Jiankun , Wang Song , Chen Chi
Published: January 2015

Multimodal biometric systems have many advantages over single‐modal biometric systems, e.g. higher recognition accuracy and security level. However, for most existing multimodal biometric systems, experiments are conducted using the unreal multimodal databases in which no samples of different biometric modules are from the same person. For example, a fingerprint sample of person A and a biometric face sample of person B will be combined to form a sample of the joint fingerprint module and face module. A multimodal biometric system is designed and tested, which is made up of two common biometrics, face and fingerprint, using a real multimodal database (a sample of the joint fingerprint module and face module is formed from the fingerprint and face of the same person) and two unreal multimodal databases. From the experimental results it is observed that there is a large discrepancy between the system performances evaluated with the real and unreal multimodal databases. This indicates that ignoring the influence of feature dependency, which has been a common practice in evaluating multimodal biometrics systems, can produce misleading system performance evaluation results.
Efficient locomotion control of biped robots on unknown sloped surfaces with central pattern generators
Authors: Cristiano J. , Puig D. , Garcia M.A.
Published: January 2015

A closed‐loop system for the central pattern generator (CPG)‐based locomotion control of biped robots that operates in the joint space is presented. The proposed system has been designed to allow biped robots to walk on unknown sloped surfaces. Feedback signals generated by the robot's inertial and force sensors are directly fed into the CPG to automatically adjust the locomotion pattern over flat and sloped terrain in real time. The proposed control system negotiates sloped surfaces similarly to state‐of‐the‐art CPG‐based control systems; however, whereas the latter must continuously solve the computationally intensive inverse kinematics of the robot, the proposed approach directly operates in the joint space, which makes it especially suitable for direct hardware implementation with electronic circuits. The performance of the proposed control system has been assessed through both simulation and real experiments on a NAO humanoid robot.
Extended state observer‐based sliding mode control for PWM‐based DC–DC buck power converter systems with mismatched disturbances
Authors: Wang Junxiao , Li Shihua , Yang Jun , Wu Bin , Li Qi
Published: January 2015

This study investigates an extended state observer (ESO)‐based sliding mode control (SMC) approach for pulse‐width modulation‐based DC–DC buck converter systems subject to mismatched disturbances. By designing a novel sliding‐mode manifold incorporated with a disturbance estimation technique, an ESO‐based SMC method is designed to deal with mismatched disturbances. A rigorous stability analysis is also presented. As compared with the nominal SMC method, the proposed method obtains a better disturbance rejection ability even the disturbances do not satisfy the so‐called matching condition. Simulations and experimental comparison results are implemented to verify the effectiveness of the proposed control method.
Concurrent multi‐agent systems with temporal logic objectives: game theoretic analysis and planning through negotiation
Authors: Fu Jie , Tanner Herbert G. , Heinz Jeffrey
Published: January 2015

This study examines equilibrium behaviour and negotiation protocol design for a class of systems composed of multiple, non‐cooperative, agents. The agents modelled as finite‐state transition systems, are autonomous, and are interacting ‘concurrently’ aiming at achieving individual tasks specified in temporal logic. Each agent has its own preferences over outcomes of its interaction with others. The agents’ goals and preferences are neither perfectly aligned nor necessarily opposing. The authors reason about agent behaviours in such a system, by formulating a concurrent multi‐agent game with infinitely many stages. To enable the synthesis of strategies, they develop a negotiation protocol which ensures that under a proper design of preferences and tasks, the mutually accepted plan is a Pareto optimal pure Nash equilibrium.
Minimum time optimal synthesis for two level quantum systems
Authors: Albertini Francesca , D’Alessandro Domenico
Published: January 2015

For the time optimal problem of an invariant system on SU(2), with two independent controls and a bound on the norm of the control, the extremals of the Pontryagin maximum principle are explicit functions of time. We use this fact here to perform the optimal synthesis for these systems, i.e., to find all time optimal trajectories. Although the Lie group SU(2) is three dimensional, time optimal trajectories can be described in the unit disk of the complex plane. We find that a circular trajectory separates optimal trajectories that reach the boundary of the unit disk from the others. Inside this separatrix circle, another trajectory (the critical trajectory) plays an important role in that all optimal trajectories end at an intersection with this curve. The results allow us to find the minimum time needed to achieve a given evolution of a two level quantum system.
Tribromobenzene on Cu(111): Temperature-dependent formation of halogen-bonded, organometallic, and covalent nanostructures
Authors: Fan Qitang , Wang Tao , Liu Liming , Zhao Jin , Zhu Junfa , Gottfried J. Michael
Published: January 2015

The temperature-controlled surface-assisted synthesis of halogen bonded, organometallic, and covalent nanostructures based on 1,3,5-tribromo-benzene (TriBB) was studied with scanning tunneling microscopy and X-ray photoemission spectroscopy in ultrahigh vacuum. Vapor deposition of TriBB onto a Cu(111) surface held at 90 K leads to the formation of large domains of a honeycomb-like organic monolayer structure stabilized by triangular nodes with Br⋯Br intermolecular bonds. Upon annealing the organic monolayer to ∼140 K, a new hexagonal close-packed structure with intact TriBB molecules connected by Cu adatoms is formed. Further warming up the sample to 300 K gives rise to the scission of C–Br bonds and formation of C–Cu–C bonds between phenyl fragments such that stable dendritic organometallic networks are formed. Larger islands of organometallic networks are obtained by maintaining the temperature of Cu(111) at 420 K during deposition of TriBB. Simultaneously, large islands of Br atoms are formed around the organometallic networks. Annealing the more extended organometallic network (prepared at 420 K) to 520 K leads to the formation of a branched covalent organic framework (COF) which comprises structural elements of porous graphene and is surrounded by Br islands. These organometallic networks and COFs appear as small dendritic and branched domains, most likely due to the steric influence exerted by the Br islands.
Correlation of infrared spectra and phase transitions in annealed proton-exchanged MgO doped LiNbO3
Authors: Sun Jian , Xu Chang-qing
Published: January 2015

Infrared spectra of OH− groups in annealed proton-exchanged (APE) 5 mol. % MgO-doped LiNbO3 (MgO:LiNbO3) crystals were studied using the Fourier transform infrared spectroscopy technique. Samples were prepared by benzoic acid proton-exchange followed with thermal annealing in oxygen. Evolutions of absorption peaks in APE MgO:LiNbO3 crystals were recorded and analyzed. Comparing with none-doped APE LiNbO3 crystals, a different phase transition behavior was found during thermal annealing. A periodically poled MgO:LiNbO3 slab waveguide was prepared using identical procedures, and the second harmonic generation (SHG) signals were measured. Comparing the obtained SHG results with the infrared spectra, relationships between the phase transitions and the recovery of second-order nonlinear coefficients during thermal annealing were investigated. Finally, a method for optimizing the performance of MgO:LiNbO3 waveguides was proposed.
Internal wave boundary layer interaction: A novel instability over broad topography
Authors: Harnanan Sandhya , Soontiens Nancy , Stastna Marek
Published: January 2015

It has been known for some time that internal wave-induced currents can drive near bed instabilities in the bottom boundary layer over a flat bottom. When the bottom is not flat, the situation can become quite complicated, with a diverse set of mechanisms responsible for instability and the subsequent transition to turbulence. Using numerical simulations, we demonstrate the existence of a mode of instability due to internal solitary wave propagation over broad topography that is fundamentally different from the two dominant paradigms of flow separation over sharp topography and global instability in the wave footprint that occurs over a flat bottom observed at high Reynolds number. We discuss both the two and three-dimensional evolution of the instability on experimental scales. The instability takes the form of a roll up of vorticity near the crest of the topography. As this region is unstratified in our simulations, little three-dimensionalization is observed. However, the instability-induced currents provide an efficient means to modulate across boundary layer transport. We subsequently extend the results to the field scale and discuss both the aspects of the instability that are consistent across scales and those that are different.
Rossby-Khantadze electromagnetic planetary waves driven by sheared zonal winds in the E-layer ionosphere
Authors: Futatani S. , Horton W. , Kahlon L. Z. , Kaladze T. D.
Published: January 2015

Nonlinear simulations of electromagnetic Rossby and Khantadze planetary waves in the presence of a shearless and sheared zonal flows in the weakly ionized ionospheric E-layer are carried out. The simulations show that the nonlinear action of the vortex structures keeps the solitary character in the presence of shearless zonal winds as well as the ideal solutions of solitary vortex in the absence of zonal winds. In the presence of sheared zonal winds, the zonal flows result in breaking into separate multiple smaller pieces. A passively convected scalar field is shown to clarify the transport associated with the vortices. The work shows that the zonal shear flows provide an energy source into the vortex structure according to the shear rate of the zonal winds.
Repetition rate stabilization of an erbium-doped all-fiber laser via opto-mechanical control of the intracavity group velocity
Authors: Shen Xuling , He Boqu , Zhao Jian , Liu Yang , Bai Dongbi , Yang Kangwen , Wang Chao , Liu Geping , Luo Daping , Liu Fengjiang , Hao Qiang , Li Wenxue , Zeng Heping
Published: January 2015

We present a method for stabilizing the repetition rate of an erbium-doped all-fiber laser by inserting an electronic polarization controller (EPC) in the fiber laser cavity. The device exhibited good integration, low cost, and convenient operation. Such a repetition rate stabilization may facilitate an all-fiber laser comb system with high integration. The repetition rate was phase-locked to a Rb reference more than 72 h with a low feedback voltage applied to one channel of the EPC. The repetition rate was 74.6 MHz. The standard deviation and the repetition rate linewidth were 1.4 and 1.7 mHz, respectively.
In-plane magnetization behaviors in the Shastry-Sutherland system TbB4: Monte Carlo simulation
Authors: Feng J. J. , Li W. C. , Qin M. H. , Xie Y. L. , Yan Z. B. , Jia X. T. , Liu J.-M.
Published: January 2015

The in-plane magnetization behaviors in TbB4 are theoretically studied using the frustrated classical XY model, including the exchange and biquadratic interactions, and the anisotropy energy. The magnetization curves at various temperatures are simulated, and the magnetic orders are uncovered by the tracking of the spin configurations. In addition, the effects of the in-plane anisotropy and biquadratic interaction on the magnetization curves are investigated in detail. The simulated results suggest that the magnetic anisotropy within the (001) plane owes to the complex interplay between these couplings, and the anisotropy term plays an important role.
Silver nanowires for transparent conductive electrode to GaN-based light-emitting diodes
Authors: Jeong Gyu-Jae , Lee Jae-Hwan , Han Sang-Hyun , Jin Won-Yong , Kang Jae-Wook , Lee Sung-Nam
Published: January 2015

Transparent, conductive, and uniform Ag nanowires (NWs) were introduced to improve the optical performance of GaN-based light-emitting diodes (LEDs) by a spin-coating technique. The Ag NWs acted as a current spreading layer, exhibiting high transmittance and low sheet resistance, and ultimately leading to high performance GaN-based LEDs with an ultra large size of 5 × 5 mm2. Compared to the transmittance of conventional LEDs without Ag NWs, the relative transmittance of LEDs with Ag NWs was approximately 90% of the overall wavelength region. However, the electroluminescence (EL) intensity of LED with Ag NWs was much higher than that of conventional LEDs without Ag NWs for injection current above 45 mA. In addition, the EL full width at half maximum of LEDs with Ag NWs was much lower than that of conventional LEDs without Ag NWs. Based on these results, we believe that the enhanced optical performance of ultra large LEDs was due to an increase in the current spreading effect.
Negative differential transconductance in electrolyte-gated ruthenate
Authors: Hassan Muhammad Umair , Dhoot Anoop Singh , Wimbush Stuart C.
Published: January 2015

We report on a study of electric field-induced doping of the highly conductive ruthenate SrRuO3 using an ionic liquid as the gate dielectric in a field-effect transistor configuration. Two distinct carrier transport regimes are identified for increasing positive gate voltage in thin (10 nm) films grown heteroepitaxially on SrTiO3 substrates. For Vg = 2 V and lower, the sample shows an increased conductivity of up to 13%, as might be expected for electron doping of a metal. At higher Vg = 2.5 V, we observe a large decrease in electrical conductivity of >20% (at 4.2 K) due to the prevalence of strongly blocked conduction pathways.
Lateral plasma etching enhanced on/off ratio in graphene nanoribbon field-effect transistor
Authors: Sun Jian , Iwasaki Takuya , Muruganathan Manoharan , Mizuta Hiroshi
Published: January 2015

Opening the transport gap in graphene by minimizing its width is highly desirable to achieve outstanding switching performance, i.e., the high on/off ratio, in its field effect transistors (FETs). In this letter, we propose a simple method to open a comparable transport gap in graphene by narrowing down it into graphene nanoribbon (GNR) via the conventional nanofabrication procedure. In the process, GNR capped with a 50-nm-wide hydrogen-silsesquioxane mask is trimmed down from the edges by lateral plasma etching. The on/off ratio of the FET device is dramatically enhanced by two orders of magnitude as etching duration increases. The large on/off ratios of ∼47 and ∼105 are achieved at room temperature and 5.4 K, respectively. The electrical measurement reveals a transport gap opening of ∼145 meV in GNR, which corresponds to a resulting width of <10 nm.
The photorefractive characteristics of bismuth-oxide doped lithium niobate crystals
Authors: Zheng Dahuai , Kong Yongfa , Liu Shiguo , Yao Jiaying , Zhang Ling , Chen Shaolin , Xu Jingjun
Published: January 2015

Bismuth-doped lithium niobate (LN:Bi) crystals were grown by Czochralski method and their optical damage resistance, photorefraction, absorption spectra, and defect energy levels were investigated. The experimental results indicate that the photorefractive properties of LN:Bi were enhanced as compared with congruent one, the photorefractive response time was greatly shortened, the photorefractive sensitivity was increased, and the diffraction efficiency of near-stoichiometric LN:Bi (SLN:Bi) reached 31.72% and 49.08% at 532 nm and 488 nm laser, respectively (light intensity of 400 mW/cm2). An absorption peak at about 350 nm was observed in the absorption spectrum of LN:Bi. And the defect energy levels simulation indicates new defect levels appear in the forbidden gap of LN:Bi crystals. Therefore bismuth can act as photorefractive centers in LN crystals.
First principle simulations on the effects of oxygen vacancy in HfO2-based RRAM
Authors: Dai Yuehua , Zhao Yuanyang , Wang Jiayu , Xu Jianbin , Yang Fei
Published: January 2015

HfO2-based resistive random access memory (RRAM) takes advantage of oxygen vacancy (V o) defects in its principle of operation. Since the change in resistivity of the material is controlled by the level of oxygen deficiency in the material, it is significantly important to study the performance of oxygen vacancies in formation of conductive filament. Excluding effects of the applied voltage, the Vienna ab initio simulation package (VASP) is used to investigate the orientation and concentration mechanism of the oxygen vacancies based on the first principle. The optimal value of crystal orientation [010] is identified by means of the calculated isosurface plots of partial charge density, formation energy, highest isosurface value, migration barrier, and energy band of oxygen vacancy in ten established orientation systems. It will effectively influence the SET voltage, forming voltage, and the ON/OFF ratio of the device. Based on the results of orientation dependence, different concentration models are established along crystal orientation [010]. The performance of proposed concentration models is evaluated and analyzed in this paper. The film is weakly conductive for the samples deposited in a mixture with less than 4.167at.% of V o contents, and the resistive switching (RS) phenomenon cannot be observed in this case. The RS behavior improves with an increase in the V o contents from 4.167at.% to 6.25at.%; nonetheless, it is found difficult to switch to a stable state. However, a higher V o concentration shows a more favorable uniformity and stability for HfO2-based RRAM.
Cycles of Investment: Bicycle Infrastructure, Gentrification, and the Restructuring of the San Francisco Bay Area
Authors: Stehlin John
Published: January 2015

Bicycling for transportation in American cities has grown dramatically in the past twenty years, symbolizing the return of capital investment and commercial vitality to formerly disinvested urban cores. The cycling ‘renaissance’ taking place to the greatest extent in gentrifying neighborhoods has been noted, but the processes relating cycling and gentrification have gone largely unexplored. This paper examines the early role that bicycle advocacy organizations in San Francisco played in articulating the specifically economic value of bicycle infrastructure investment. This narrative is now commonplace, and widely applied both to neighborhood revitalization and urban competition for ‘talent’. This alliance of bicycle advocacy with the ‘livable’ turn of gentrification raises serious questions for those who would pursue a more democratic and socially just politics of the bicycle.
At the Mercy of the Mountain? Field Stations and the Culture of Volcanology
Authors: Donovan Amy , Oppenheimer Clive
Published: January 2015

This paper discusses the role of volcano observatories as local sites of knowledge production through the monitoring of volcanoes, and links this with the global production of knowledge in volcanology. The paper initially discusses the institutional geography of volcanological science, and relates this broadly to the geography of science and science studies. It then focuses on interview data to draw some insights into the experiences of observatory and university scientists. Observatories have to provide scientific advice to local authorities and also engage with the international scientific community. They may act as gatekeepers to the field, and as rich sources of baseline data for research projects. As such, they have a pivotal role in the production of knowledge beyond the field sites—and are also involved in the protection of populations. The paper argues that the tension between academic research and volcano monitoring that occurs at many observatories is an important part of the process of knowledge production in volcanology, and also reveals the complex geographies of social responsibility and collaboration that exist around active volcanoes as scientific networks and territorial governance structures interact.
‘Fixing’ the climate crisis: capital, states, and carbon offsetting in India
Authors: Bryant Gareth , Dabhi Siddhartha , Böhm Steffen
Published: January 2015

The paper analyzes dynamics of accumulation and displacement in the Clean Development Mechanism (CDM). It combines the theoretical work of David Harvey and James O’Connor with a case study of the Gujarat Fluorochemicals Limited HFC-23 destruction project in Gujarat, India. The framework is used to connect the factors driving opportunities for capital accumulation in the CDM market with the causes of social and ecological dislocation at the local project level. We argue that the CDM is a spatial fix to the ecological crisis of climate change which secures conditions of production for fossil fuel industries and promotes new sites of accumulation for other companies. The political–economic ‘fix’ is dependent on ‘fixing’ a global sociospatial divide between developed and developing countries down to ‘fixed’ projects at the local level. This spatial fix facilitates a displacement of the costs of responding to the climate crisis from North to South.
No Escape? The Coordination Problem in Heritage Preservation
Authors: Holman Nancy , Ahlfeldt Gabriel M
Published: January 2015

Conservation Areas (CAs) are among the most restrictive English planning policies. Designation implies a significant limitation of owners' control over the shape and appearance of their properties. The policy, however, can also be argued to solve a sort of ‘prisoner's dilemma’, in which it might be collectively rational to preserve the character of an area, but an individual homeowner may be tempted to inappropriately alter their property, thus free-riding on nearby properties' character. The net benefit of the policy depends largely on the existence of positive ‘heritage effects’ and acknowledgement from homeowners that policy contributes to neighbourhood stability and the preservation of these positive effects. Our results of a mixed-method analysis of close to 1 million property transactions near to about 8000 CAs and 111 interviews with residents in nine representative CAs in Greater London suggest that positive heritage externalities exist and that residents in CAs tend to value their local environments, acknowledge the need for planning control, and execute their right to object to neighbour's planning request.
Borders, One-Dimensionality, and Illusion in the War on Drugs
Authors: Walker Margath A
Published: January 2015

In this paper I argue for the necessity and value of using critical theory to review tripartite politics across North and South America in the war on drugs. In particular, Herbert Marcuse's concept of one-dimensionality—a description of social structures and behaviors incapable of perceiving alternatives to existing realities—is elaborated. Using a Marcusian lens, I unpack key policy documents within the Mérida II Initiative, and the United States Northern Command and the United States Southern Command. The paper examines the mechanisms through which particular ‘realities’ emerge as prominent. In doing so, discursive and material tactics, embedded in political strategies which construct tangible problems to be solved, are highlighted. In the course of prescriptive policy measures, three regulating fictions materialize. First, Mérida II is cast in terms of a paradigm shift. Second, unilateral policies become bilateral agreements. And third, the hemispheric scale unfolds into regional divisions. All are tied in with a historical legacy of enacting symbolic illusion and a pattern of thought and behavior reduced to the given system. There are at least two significant outcomes. The first is the rendering of oppositional alternatives as utopian or illusory. The second is the deployment of difference which continuously reproduces North–South divisions and upholds the status quo.
Suppressive and Enhancing Effects in Early Visual Cortex during Illusory Shape Perception: A Comment on Kok and de Lange (2014)
Authors: Moors Pieter
Published: January 2015

In a recent functional magnetic resonance imaging study, Kok and de Lange (2014) observed that BOLD activity for a Kanizsa illusory shape stimulus, in which pacmen-like inducers elicit an illusory shape percept, was either enhanced or suppressed relative to a nonillusory control configuration depending on whether the spatial profile of BOLD activity in early visual cortex was related to the illusory shape or the inducers, respectively. The authors argued that these findings fit well with the predictive coding framework, because top-down predictions related to the illusory shape are not met with bottom-up sensory input and hence the feedforward error signal is enhanced. Conversely, for the inducing elements, there is a match between top-down predictions and input, leading to a decrease in error. Rather than invoking predictive coding as the explanatory framework, the suppressive effect related to the inducers might be caused by neural adaptation to perceptually stable input due to the trial sequence used in the experiment.
Growth suppression and cell death by pyridoxal is dependent on p53 in the human breast cancer cell line MCF-7
Authors: Minamino Masaki , Oka Tatsuzo , Kanouchi Hiroaki
Published: January 2015

Vitamin B6 compound, pyridoxine (PN), has shown antitumor action. Our previous experiments showed that PN induces expression of insulin-like growth factor binding protein-3 to arrest proliferation and induce cell death. This induction is inhibited by the p53-specific inhibitor pifithrin-α. Here, we report that another B6 compound, pyridoxal (PL), strongly inhibited MCF-7 cell growth compared to PN. PL induced the G0/G1 arrest and the accumulation of subG1 population. Although p53 mRNA was not changed by PL, 0.5 mM PL increased the protein level in MCF-7 cells. The cell growth suppression by 0.5 mM PL did not occur when p53 expression was knocked down using siRNA. Together, these data suggest that PL accumulate p53 and PL-induced cell growth suppression is dependent on p53 in MCF-7 breast cancer cells.
Intraoperative Core Temperature Patterns, Transfusion Requirement, and Hospital Duration in Patients Warmed with Forced Air
Authors: Sun Zhuo , Honar Hooman , Sessler Daniel I. , Dalton Jarrod E. , Yang Dongsheng , Panjasawatwong Krit , Deroee Armin F. , Salmasi Vafi , Saager Leif , Kurz Andrea
Published: January 2015

AbstractAbstract

In almost 59,000 adults having surgery lasting more than an hour, core temperatures decreased during the first hour of surgery, thereafter rising to an average final temperature of 36.3°C. Hypothermia significantly increased both transfusion requirements and duration of hospitalization, but only the increase in transfusions was clinically important.

Background:

Core temperature patterns in patients warmed with forced air remain poorly characterized. Also unknown is the extent to which transient and mild intraoperative hypothermia contributes to adverse outcomes in broad populations.

Methods:

We evaluated esophageal (core) temperatures in 58,814 adults having surgery lasting >60 min who were warmed with forced air. Independent associations between hypothermic exposure and transfusion requirement and duration of hospitalization were evaluated.

Results:

In every percentile subgroup, core temperature decreased during the first hour and subsequently increased. The mean lowest core temperature during the first hour was 35.7 ± 0.6°C. Sixty-four percent of the patients reached a core temperature threshold of <36°C 45 min after induction; 29% reached a core temperature threshold of <35.5°C. Nearly half the patients had continuous core temperatures <36°C for more than an hour, and 20% of the patients were <35.5°C for more than an hour. Twenty percent of patients had continuous core temperatures <36°C for more than 2 h, and 8% of the patients were below 35.5°C for more than 2 h. Hypothermia was independently associated with both transfusions and duration of hospitalization, although the prolongation of hospitalization was small.

Conclusions:

Even in actively warmed patients, hypothermia is routine during the first hour of anesthesia. Thereafter, average core temperatures progressively increase. Nonetheless, intraoperative hypothermia was common, and often prolonged. Hypothermia was associated with increased transfusion requirement, which is consistent with numerous randomized trials.
Escherichia coli and Staphylococcus phages: effect of translation initiation efficiency on differential codon adaptation mediated by virulent and temperate lifestyles
Authors: Prabhakaran Ramanandan , Chithambaram Shivapriya , Xia Xuhua
Published: January 2015

Rapid biosynthesis is key to the success of bacteria and viruses. Highly expressed genes in bacteria exhibit a strong codon bias corresponding to the differential availability of tRNAs. However, a large clade of lambdoid coliphages exhibits relatively poor codon adaptation to the host translation machinery, in contrast to other coliphages that exhibit strong codon adaptation to the host. Three possible explanations were previously proposed but dismissed: (1) the phage-borne tRNA genes that reduce the dependence of phage translation on host tRNAs, (2) lack of time needed for evolving codon adaptation due to recent host switching, and (3) strong strand asymmetry with biased mutation disrupting codon adaptation. Here, we examined the possibility that phages with relatively poor codon adaptation have poor translation initiation which would weaken the selection on codon adaptation. We measured translation initiation by: (1) the strength and position of the Shine–Dalgarno (SD) sequence, and (2) the stability of the secondary structure of sequences flanking the SD and start codon known to affect accessibility of the SD sequence and start codon. Phage genes with strong codon adaptation had significantly stronger SD sequences than those with poor codon adaptation. The former also had significantly weaker secondary structure in sequences flanking the SD sequence and start codon than the latter. Thus, lambdoid phages do not exhibit strong codon adaptation because they have relatively inefficient translation initiation and would benefit little from increased elongation efficiency. We also provided evidence suggesting that phage lifestyle (virulent versus temperate) affected selection intensity on the efficiency of translation initiation and elongation.
Genetic characterization of human coxsackievirus A6 variants associated with atypical hand, foot and mouth disease: a potential role of recombination in emergence and pathogenicity
Authors: Gaunt Eleanor , Harvala Heli , Österback Riikka , Sreenu Vattipally B. , Thomson Emma , Waris Matti , Simmonds Peter
Published: January 2015

Human coxsackievirus A6 (CVA6) is an enterically transmitted enterovirus. Until recently, CVA6 infections were considered as being of minor clinical significance, and only rarely aetiologically linked with hand, foot and mouth disease (HFMD) associated with other species A enteroviruses (particularly EV71 and CVA16). From 2008 onwards, however, CVA6 infections have been associated with several outbreaks worldwide of atypical HFMD (aHFMD) accompanied by a varicelliform rash. We recently reported CVA6-associated eczema herpeticum occurring predominantly in children and young adults in Edinburgh in January and February 2014. To investigate genetic determinants of novel clinical phenotypes of CVA6, we genetically characterized and analysed CVA6 variants associated with eczema herpeticum in Edinburgh in 2014 and those with aHFMD in CAV isolates collected from 2008. A total of eight recombinant forms (RFs) have circulated worldwide over the past 10 years, with the particularly recent appearance of RF-H associated with eczema herpeticum cases in Edinburgh in 2014. Comparison of phylogenies and divergence of complete genome sequences of CVA6 identified recombination breakpoints in 2A–2C, within VP3, and between 5′ untranslated region and VP1. A Bayesian temporal reconstruction of CVA6 evolution since 2004 provided estimates of dates and the actual recombination events that generated more recently appearing recombination groups (RF-E, -F, -G and -H). Associations were observed between recombination groups and clinical presentations of herpangina, aHFMD and eczema herpeticum, but not with VP1 or other structural genes. These observations provided evidence that NS gene regions may potentially contribute to clinical phenotypes and outcomes of CVA6 infection.
Alternative splicing QTLs in European and African populations using Altrans, a novel method for splice junction quantification
Authors: Ongen Halit , Dermitzakis Emmanouil T.
Published: January 2015

With the advent of RNA-sequencing technology we now have the power to detect different types of alternative splicing and how DNA variation affects splicing. However, given the short read lengths used in most population based RNA-sequencing experiments, quantifying transcripts accurately remains a challenge. Here we present a novel method, Altrans, for discovery of alternative splicing quantitative trait loci (asQTLs). To assess the performance of Altrans we compared it to Cufflinks, a well-established transcript quantification method. Simulations show that in the presence of transcripts absent from the annotation, Altrans performs better in quantifications than Cufflinks. We have applied Altrans and Cufflinks to the Geuvadis dataset, which comprises samples from European and African populations, and discovered (FDR = 1%) 1806 and 243 asQTLs with Altrans, and 1596 and 288 asQTLs with Cufflinks for Europeans and Africans, respectively. Although Cufflinks results replicated better across the two populations, this likely due to the increased sensitivity of Altrans in detecting harder to detect associations. We show that, by discovering a set of asQTLs in a smaller subset of European samples and replicating these in the remaining larger subset of Europeans, both methods achieve similar replication levels (94% and 98% replication in Altrans and Cufflinks, respectively). We find that method specific asQTLs are largely due to different types of alternative splicing events detected by each method. We overlapped the asQTLs with biochemically active regions of the genome and observed significant enrichments for many functional marks and variants in splicing regions, highlighting the biological relevance of the asQTLs identified. All together, we present a novel approach for discovering asQTLs that is a more direct assessment of splicing compared to other methods and is complementary to other transcript quantification methods.
Revisiting Demand Rules for Gene Regulation
Authors: Prajapat Mahendra Kumar , Jain Kirti , Choudhury Debika , Choudhary Gauri S. , Saini Supreet
Published: January 2015

Starting with Savageau’s pioneering work from 1970s, here, we choose the simplest transcription network and ask: How does the cell choose a regulatory topology from the different available possibilities? We study the natural distribution of topologies at genome, systems, and micro-level inE. coliand perform stochastic simulations to help explain the differences in natural distributions. Analyzing regulation of amino acid biosynthesis and carbon utilization inE. coliandB. subtilis, we observe many deviations from the demand rules, and observe an alternate pattern emerging. Overall, our results indicate that choice of topology is drawn randomly from a pool of all networks which satisfy the kinetic requirements of the cell, as dictated by physiology. In short, simply, the cell picks “whatever works”.
A systems-level approach to parental genomic imprinting: the imprinted gene network includes extracellular matrix genes and regulates cell cycle exit and differentiation
Authors: Al Adhami Hala , Evano Brendan , Le Digarcher Anne , Gueydan Charlotte , Dubois Emeric , Parrinello Hugues , Dantec Christelle , Bouschet Tristan , Varrault Annie , Journot Laurent
Published: January 2015

Genomic imprinting is an epigenetic mechanism that restrains the expression of ∼100 eutherian genes in a parent-of-origin-specific manner. The reason for this selective targeting of genes with seemingly disparate molecular functions is unclear. In the present work, we show that imprinted genes are coexpressed in a network that is regulated at the transition from proliferation to quiescence and differentiation during fibroblast cell cycle withdrawal, adipogenesis in vitro, and muscle regeneration in vivo. Imprinted gene regulation is not linked to alteration of DNA methylation or to perturbation of monoallelic, parent-of-origin-dependent expression. Overexpression and knockdown of imprinted gene expression alters the sensitivity of preadipocytes to contact inhibition and adipogenic differentiation. In silico and in cellulo experiments showed that the imprinted gene network includes biallelically expressed, nonimprinted genes. These control the extracellular matrix composition, cell adhesion, cell junction, and extracellular matrix-activated and growth factor–activated signaling. These observations show that imprinted genes share a common biological process that may account for their seemingly diverse roles in embryonic development, obesity, diabetes, muscle physiology, and neoplasm.
A three-dimensional coordination polymer based on the Zn4(μ3-OH)2unit: poly[[(μ4-benzene-1,4-dicarboxylato)bis(μ3-benzene-1,4-dicarboxylato)bis(μ3-hydroxido)bis(1,10-phenanthroline-5,6-dione)tetrazinc] dihydrate]
Authors: Wen Meng , Xiao Zu-Ping , Wang Chun-Ya , Huang Xi-He
Published: January 2015

The title compound, {[Zn4(C8H4O4)3(OH)2(C12H6N2O2)2]·2H2O}n, has been prepared hydrothermally by the reaction of Zn(NO3)2·6H2O with benzene-1,4-dicarboxylic acid (H2bdc) and 1,10-phenanthroline-5,6-dione (pdon) in H2O. In the crystal structure, a tetranuclear Zn4(OH)2fragment is located on a crystallographic inversion centre which relates two subunits, each containing a [ZnN2O4] octahedron and a [ZnO4] tetrahedron bridged by a μ3-OH group. The pdon ligand chelates to zinc through its two N atoms to form part of the [ZnN2O4] octahedron. The two crystallographically independent bdc2−ligands are fully deprotonated and adopt μ3-κO:κO′:κO′′ and μ4-κO:κO′:κO′′:κO′′′ coordination modes, bridging three or four ZnIIcations, respectively, from two Zn4(OH)2units. The Zn4(OH)2fragment connects six neighbouring tetranuclear units through four μ3-bdc2−and two μ4-bdc2−ligands, forming a three-dimensional framework with uninodal 6-connected α-Po topology, in which the tetranuclear Zn4(OH)2units are considered as 6-connected nodes and the bdc2−ligands act as linkers. The uncoordinated water molecules are located on opposite sides of the Zn4(OH)2unit and are connected to it through hydrogen-bonding interactions involving hydroxide and carboxylate groups. The structure is further stabilized by extensive π–π interactions between the pdon and μ4-bdc2−ligands.