bluuebunny/crossref_metadata_2025 huggingface dataset:
Automated Core–Penumbra Quantification in Neonatal Ischemic Brain Injury
Authors: Ghosh Nirmalya , Yuan Xiangpeng , Turenius Christine I , Tone Beatriz , Ambadipudi Kamalakar , Snyder Evan Y , Obenaus Andre , Ashwal Stephen
Published: August 2012

Neonatal hypoxic-ischemic brain injury (HII) and arterial ischemic stroke (AIS) result in irreversibly injured (core) and salvageable (penumbral) tissue regions. Identification and reliable quantification of salvageable tissue is pivotal to any effective and safe intervention. Magnetic resonance imaging (MRI) is the current standard to distinguish core from penumbra using diffusion-perfusion mismatch (DPM). However, subtle MR signal variations between core–penumbral regions make their visual delineation difficult. We hypothesized that computational analysis of MRI data provides a more accurate assessment of core and penumbral tissue evolution in HII/AIS. We used two neonatal rat-pup models of HII/AIS (unilateral and global hypoxic-ischemia) and clinical data sets from neonates with AIS to test our noninvasive, automated computational approach, Hierarchical Region Splitting (HRS), to detect and quantify ischemic core–penumbra using only a single MRI modality (T2- or diffusion-weighted imaging, T2WI/DWI). We also validated our approach by comparing core–penumbral images (from HRS) to DPM with immunohistochemical validation of HII tissues. Our translational and clinical data results showed that HRS could accurately and reliably distinguish the ischemic core from penumbra and their spatiotemporal evolution, which may aid in the vetting and execution of effective therapeutic interventions as well as patient selection.
Drug Transport across the Blood–Brain Barrier
Authors: Pardridge William M
Published: August 2012

The blood–brain barrier (BBB) prevents the brain uptake of most pharmaceuticals. This property arises from the epithelial-like tight junctions within the brain capillary endothelium. The BBB is anatomically and functionally distinct from the blood–cerebrospinal fluid barrier at the choroid plexus. Certain small molecule drugs may cross the BBB via lipid-mediated free diffusion, providing the drug has a molecular weight <400 Da and forms <8 hydrogen bonds. These chemical properties are lacking in the majority of small molecule drugs, and all large molecule drugs. Nevertheless, drugs can be reengineered for BBB transport, based on the knowledge of the endogenous transport systems within the BBB. Small molecule drugs can be synthesized that access carrier-mediated transport (CMT) systems within the BBB. Large molecule drugs can be reengineered with molecular Trojan horse delivery systems to access receptor-mediated transport (RMT) systems within the BBB. Peptide and antisense radiopharmaceuticals are made brain-penetrating with the combined use of RMT-based delivery systems and avidin–biotin technology. Knowledge on the endogenous CMT and RMT systems expressed at the BBB enable new solutions to the problem of BBB drug transport.
Probing why trypanosomes assemble atypical cytochrome c with an AxxCH haem-binding motif instead of CxxCH
Authors: Ginger Michael L. , Sam Katharine A. , Allen James W. A.
Published: August 2012

Mitochondrial cytochromes c and c1 are core components of the respiratory chain of all oxygen-respiring eukaryotes. These proteins contain haem, covalently bound to the polypeptide in a catalysed post-translational modification. In all eukaryotes, except members of the protist phylum Euglenozoa, haem attachment is to the cysteine residues of a CxxCH haem-binding motif. In the Euglenozoa, which include medically relevant trypanosomatid parasites, haem attachment is to a single cysteine residue in an AxxCH haem-binding motif. Moreover, genes encoding known c-type cytochrome biogenesis machineries are all absent from trypanosomatid genomes, indicating the presence of a novel biosynthetic apparatus. In the present study, we investigate expression and maturation of cytochrome c with a typical CxxCH haem-binding motif in the trypanosomatids Crithidia fasciculata and Trypanosoma brucei. Haem became attached to both cysteine residues of the haem-binding motif, indicating that, in contrast with previous hypotheses, nothing prevents formation of a CxxCH cytochrome c in euglenozoan mitochondria. The cytochrome variant was also able to replace the function of wild-type cytochrome c in T. brucei. However, the haem attachment to protein was not via the stereospecifically conserved linkage universally observed in natural c-type cytochromes, suggesting that the trypanosome cytochrome c biogenesis machinery recognized and processed only the wild-type single-cysteine haem-binding motif. Moreover, the presence of the CxxCH cytochrome c resulted in a fitness cost in respiration. The level of cytochrome c biogenesis in trypanosomatids was also found to be limited, with the cells operating at close to maximum capacity.
The proximal C-terminus of α1C subunits is necessary for junctional membrane targeting of cardiac L-type calcium channels
Authors: Nakada Tsutomu , Flucher Bernhard E. , Kashihara Toshihide , Sheng Xiaona , Shibazaki Toshihide , Horiuchi-Hirose Miwa , Gomi Simmon , Hirose Masamichi , Yamada Mitsuhiko
Published: August 2012

In cardiac myocytes, LTCCs (L-type calcium channels) form a functional signalling complex with ryanodine receptors at the JM (junctional membrane). Although the specific localization of LTCCs to the JM is critical for excitation–contraction coupling, their targeting mechanism is unclear. Transient transfection of GFP (green fluorescent protein)–α1S or GFP–α1C, but not P/Q-type calcium channel α1A, in dysgenic (α1S-null) GLT myotubes results in correct targeting of these LTCCs to the JMs and restoration of action-potential-induced Ca2+ transients. To identify the sequences of α1C responsible for JM targeting, we generated a range of α1C–α1A chimaeras, deletion mutants and alanine substitution mutants and studied their targeting properties in GLT myotubes. The results revealed that amino acids L1681QAGLRTL1688 and P1693EIRRAIS1700, predicted to form two adjacent α-helices in the proximal C-terminus, are necessary for the JM targeting of α1C. The efficiency of restoration of action-potential-induced Ca2+ transients in GLT myotubes was significantly decreased by mutations in the targeting motif. JM targeting was not disrupted by the distal C-terminus of α1C which binds to the second α-helix. Therefore we have identified a new structural motif in the C-terminus of α1C that mediates the targeting of cardiac LTCCs to JMs independently of the interaction between proximal and distal C-termini of α1C.
First fusion proton measurements in TEXTOR plasmas using activation technique
Authors: Bonheure G. , Mlynar J. , Wassenhove G. Van , Hult M. , González de Orduña R. , Lutter G. , Vermaercke P. , Huber A. , Schweer B. , Esser G. , Biel W.
Published: August 2012

MeV particle loss measurements from fusion plasmas, in particular alpha particles, remain difficult in large fusion devices and further R&D is needed for ITER. This paper describes the first attempt to measure 3 MeV escaping fusion protons emitted from TEXTOR tokamak plasmas using activation technique. This technique was successfully demonstrated, initially, in 2006 on the JET tokamak. An ion camera equipped with a collimator and several types of activation detectors was installed inside the TEXTOR vacuum vessel to perform these measurements. After irradiation, the detectors were analyzed using ultra low level gamma-ray spectrometry at the HADES underground laboratory. 3 MeV escaping fusion protons were detected in larger number −∼6 times more - compared to earlier measurements using this technique on JET. Another major progress was the reduction of the cooling time by a factor of 50, which made possible to detect radionuclides with half-life of less than 90 min.
Propagation characteristics of a Gaussian laser beam in plasma with modulated collision frequency
Authors: Wang Ying , Yuan Chengxun , Zhou Zhongxiang , Gao Ruilin , Li Lei , Du Yanwei
Published: August 2012

The propagation characteristics of a Gaussian laser beam in cold plasma with the electron collision frequency modulated by laser intensity are presented. The nonlinear dynamics of the ponderomotive force, which induce nonlinear self-focusing as opposed to spatial diffraction, are considered. The effective dielectric function of the Drude model and complex eikonal function are adopted in deriving coupled differential equations of the varying laser beam parameters. In the framework of ponderomotive nonlinearity, the frequency of electron collision in plasmas, which is proportional to the spatial electron density, is strongly interrelated with the laser beam propagation characteristics. Hence, the propagation properties of the laser beam and the modulated electron collision frequency distribution in plasma were studied and explained in depth. Employing this self-consistent method, the obtained simulation results approach practical conditions, which is of significance to the study of laser–plasma interactions.
Indirect Coulomb energy for two-dimensional atoms
Authors: Benguria Rafael D. , Tušek Matěj
Published: August 2012

In this paper we provide a family of lower bounds on the indirect Coulomb energy for atomic and molecular systems in two dimensions in terms of a functional of the single particle density with gradient correction terms.
The scaling limit of the energy correlations in non-integrable Ising models
Authors: Giuliani Alessandro , Greenblatt Rafael L. , Mastropietro Vieri
Published: August 2012

We obtain an explicit expression for the multipoint energy correlations of a non-solvable two-dimensional Ising models with nearest neighbor ferromagnetic interactions plus a weak finite range interaction of strength λ, in a scaling limit in which we send the lattice spacing to zero and the temperature to the critical one. Our analysis is based on an exact mapping of the model into an interacting lattice fermionic theory, which generalizes the one originally used by Schultz, Mattis, and Lieb for the nearest neighbor Ising model. The interacting model is then analyzed by a multiscale method first proposed by Pinson and Spencer. If the lattice spacing is finite, then the correlations cannot be computed in closed form: rather, they are expressed in terms of infinite, convergent, power series in λ. In the scaling limit, these infinite expansions radically simplify and reduce to the limiting energy correlations of the integrable Ising model, up to a finite renormalization of the parameters. Explicit bounds on the speed of convergence to the scaling limit are derived.
Predicting conditions for microscale surfactant mediated tipstreaming
Authors: Moyle Todd M. , Walker Lynn M. , Anna Shelley L.
Published: August 2012

Microscale tipstreaming is a unique method to overcome the limiting length scale in microfluidics allowing for production of submicron-sized droplets. Tipstreaming is the ejection of small drops from a liquid thread formed by interfacial tension gradients and convective transport of surfactant. Controlling and understanding this process is essential for successful application in areas such as synthesis of nano-scale particles, manipulation of biomolecules, enzyme activity studies, and others. However, models that predict operating conditions for microscale tipstreaming do not currently exist. In this work, we develop a semi-analytical model aimed at capturing the essential physics of the tipstreaming mechanism. The model relies on interfacial shape observations indicative of microscale tipstreaming to simplify the fluid flow and surfactant transport equations. The result is an interfacial mass balance of surfactant. Conditions where the mass balance can be satisfied define the operating conditions for microscale tipstreaming. Results from the model are compared with our own experimental results. Good agreement is found between model predictions and experiments. Scaling of each boundary that controls the feasible tipstreaming region is given. Finally, the model is able to guide selection of device geometry and surfactant properties to shift or expand the feasible region where microscale tipstreaming is expected.
Properties of patchy colloidal particles close to a surface: A Monte Carlo and density functional study
Authors: Gnan Nicoletta , de las Heras Daniel , Tavares José Maria , da Gama Margarida M. Telo , Sciortino Francesco
Published: August 2012

We investigate the behavior of a patchy particle model close to a hard-wall via Monte Carlo simulation and density functional theory (DFT). Two DFT approaches, based on the homogeneous and inhomogeneous versions of Wertheim's first order perturbation theory for the association free energy are used. We evaluate, by simulation and theory, the equilibrium bulk phase diagram of the fluid and analyze the surface properties for two isochores, one of which is close to the liquid side of the gas-liquid coexistence curve. We find that the density profile near the wall crosses over from a typical high-temperature adsorption profile to a low-temperature desorption one, for the isochore close to coexistence. We relate this behavior to the properties of the bulk network liquid and find that the theoretical descriptions are reasonably accurate in this regime. At very low temperatures, however, an almost fully bonded network is formed, and the simulations reveal a second adsorption regime which is not captured by DFT. We trace this failure to the neglect of orientational correlations of the particles, which are found to exhibit surface induced orientational order in this regime.
Broadside mobility of a disk in a viscous fluid near a plane wall with no-slip boundary condition
Authors: Felderhof B. U.
Published: August 2012

The broadside motion of a disk in a viscous fluid towards a planar wall with no-slip boundary condition is studied on the basis of the steady-state Stokes equations. It is shown that flow velocity and pressure of the fluid can be found conveniently from a superposition of elementary complex stream functions. The two amplitude functions characterizing the superposition are found from the numerical solution of a pair of integral equations for the axial and radial velocity components at the disk. The numerical procedure converges fast, provided the distance to the plane is not much smaller than the radius of the disk. For small distance the flow is well approximated by lubrication theory.
Theory for cross effect dynamic nuclear polarization under magic-angle spinning in solid state nuclear magnetic resonance: The importance of level crossings
Authors: Thurber Kent R. , Tycko Robert
Published: August 2012

We present theoretical calculations of dynamic nuclear polarization (DNP) due to the cross effect in nuclear magnetic resonance under magic-angle spinning (MAS). Using a three-spin model (two electrons and one nucleus), cross effect DNP with MAS for electron spins with a large g-anisotropy can be seen as a series of spin transitions at avoided crossings of the energy levels, with varying degrees of adiabaticity. If the electron spin-lattice relaxation time T1e is large relative to the MAS rotation period, the cross effect can happen as two separate events: (i) partial saturation of one electron spin by the applied microwaves as one electron spin resonance (ESR) frequency crosses the microwave frequency and (ii) flip of all three spins, when the difference of the two ESR frequencies crosses the nuclear frequency, which transfers polarization to the nuclear spin if the two electron spins have different polarizations. In addition, adiabatic level crossings at which the two ESR frequencies become equal serve to maintain non-uniform saturation across the ESR line. We present analytical results based on the Landau-Zener theory of adiabatic transitions, as well as numerical quantum mechanical calculations for the evolution of the time-dependent three-spin system. These calculations provide insight into the dependence of cross effect DNP on various experimental parameters, including MAS frequency, microwave field strength, spin relaxation rates, hyperfine and electron-electron dipole coupling strengths, and the nature of the biradical dopants.
Radiative heat transfer analysis of a directly irradiated cavity-type solar thermochemical reactor by Monte-Carlo ray tracing
Authors: Villafán-Vidales H. I. , Abanades S. , Arancibia-Bulnes C. A. , Riveros-Rosas D. , Romero-Paredes H. , Espinosa-Paredes G. , Estrada C. A.
Published: August 2012

Radiative heat transfer in a 1 kW cavity-type solar reactor devoted to the thermal reduction of compressed ZnO and SnO2 powders is analyzed by a Monte Carlo ray tracing simulation. The developed model takes into account the radiative properties of the reactant particles and of the ceramic cavity walls, as well as the angular intensity distribution of the incoming concentrated solar irradiation. The model also includes the conduction heat losses through the lateral walls and the energy consumed by the endothermic chemical reaction. It is used to predict the temperature and the absorbed flux density profiles on the inner cavity walls for different main features of the reactor, concerning the dimensions of the cavity and the type of reactant. Results show that the absorbed flux density profile and the theoretical thermochemical efficiency change with the cavity aspect ratio and with the oxide reactant. The cavity with an aspect ratio of 3 and a SnO2 pellet undergoing dissociation presents the highest thermochemical efficiency. Additionally, a different configuration of the reactor design is considered, which consists in implementing a layer of reactive particles on the inner lateral cavity wall. The model highlights that this type of reactor operation with a reactant layer on the lateral cavity wall results in an improved thermochemical efficiency.
Role of Ti phases in the modulation of border traps at the TiO2/n-Si interfaces
Authors: Nasim F. , Ali A. , Hafizuddin Mohammad , Bhatti A. S.
Published: August 2012

Charge accumulation at interfaces is a key issue for the use of high dielectric constant materials in nanoelectronics. In this work, we report the charge accumulation behavior at the TiO2/n-Si interfaces formed at various growth temperatures. Growth of TiO2 in an oxygen deficient environment led to the formation of rutile phase in the as-grown films. The anatase phase was recovered by annealing in air and the ratio of anatase to rutile phase in the TiO2 films improved considerably. The amount of charge accumulation and the direction of charge injection were studied by obtaining C–V hysteresis curves in the as-grown and the annealed TiO2 films. It was observed that the amount of accumulated charges decreased as the density of interface border traps dropped considerably due to annealing. X-ray photo-electron spectroscopy revealed the presence of two major phases corresponding to TiO2 and Ti2O3, due to the existence of oxygen deficiencies. The annealing in air resulted in appreciable increase in the weight percentage of TiO2 phase in samples grown at high temperatures. The healing of oxygen vacancies improved with the increase in the weight percentage of TiO2. Thus, it was concluded that the accumulated charges were mainly due to oxygen deficiencies and the healing of oxygen defects led to a drop in the interface charges, thus, bringing the interface close to ideal.
Structural rotation of Al under uniaxial compression: A first-principles prediction
Authors: Yadav S. K. , Wang J. , Ramprasad R. , Misra A. , Liu X.-Y.
Published: August 2012

We report on a density functional theory based study of a novel structural rotation of single-crystal aluminum (Al) under uniaxial compression. It was found that under strains either along the 〈112〉 or the 〈111〉 direction, beyond a critical stress of about 13 GPa, the Al crystal can rotate through shear in the Shockley partial direction on the {111} plane, to relieve internal stresses. This phenomenon reveals a new mechanism leading to the onset of homogeneous dislocation nucleation in face-centered-cubic materials under high uniaxial compressions.
Effect of Pr substitution on structural and dielectric properties of SrTiO3
Authors: Wang Xiaofei , Hu Qiubo , Li Liben , Lu Xiaomei
Published: August 2012

Pr-doped SrTiO3 ceramics were fabricated by the conventional solid-state reaction method. Pr-doping greatly decreased the lattice parameters and the average grain size of SrTiO3 ceramics sample. Two thermally activated dielectric relaxations were found for the low- and high-temperature relaxations, respectively. By means of a detailed analysis, the low-temperature relaxation was ascribed to the electric hopping between Pr3+ and Pr4+ induced by the Pr-doping, and the origin of the high-temperature relaxation was changed from oxygen vacancies to the polar nanoregions with the increase of Pr content.
Ferromagnetism of Cd doped SnO2: A first-principles study
Authors: Zhang Kai-Cheng , Li Yong-Feng , Liu Yong , Zhu Yan
Published: August 2012

The magnetic properties of Cd-doped SnO2 are studied by first-principles calculations. Our results reveal that the doped system favors a ferromagnetic state and high Curie-temperature can be expected in it. The doped Cd atoms do not tend to form clusters in tin oxide. The systems can be favorably synthesized in oxygen-rich ambient. The origin of ferromagnetism can be attributed to the hole-mediated p-d hybridization between Cd and O atoms.
Ellipsometrically determined optical properties of nickel-containing tungsten oxide thin films: Nanostructure inferred from effective medium theory
Authors: Valyukh I. , Green S. V. , Granqvist C. G. , Gunnarsson K. , Arwin H. , Niklasson G. A.
Published: August 2012

Films of NixW1−x oxide with 0.05 ≤ x ≤ 0.53 were produced by reactive dc magnetron co-sputtering onto Si. Such films have documented electrochromism. Spectroscopic ellipsometry was used to extract accurate data on the dielectric function in the photon range 0.062 to 5.62 eV. The results for 0.62 to 5.62 eV were compared with computations from the Bruggeman effective medium theory applied to two nanostructural models: one representing a random mixture of structural entities characterized by the dielectric functions of WO3 and NiWO4 and the other describing a random mixture of WO3 and NiO. Unambiguous evidence was found in favor of the former model, and hence the films are composed of nanosized tungsten oxide and nickel tungstate. This agrees excellently with an earlier investigation of ours on NixW1−x oxide films, where nanostructure was inferred from Raman spectroscopy, x-ray photoelectron spectroscopy, and x-ray diffraction.
Ultra-precise tracking control of piezoelectric actuators via a fuzzy hysteresis model
Authors: Li Pengzhi , Yan Feng , Ge Chuan , Zhang Mingchao
Published: August 2012

In this paper, a novel Takagi-Sugeno (T-S) fuzzy system based model is proposed for hysteresis in piezoelectric actuators. The antecedent and consequent structures of the fuzzy hysteresis model (FHM) can be, respectively, identified on-line through uniform partition approach and recursive least squares (RLS) algorithm. With respect to controller design, the inverse of FHM is used to develop a feedforward controller to cancel out the hysteresis effect. Then a hybrid controller is designed for high-performance tracking. It combines the feedforward controller with a proportional integral differential (PID) controller favourable for stabilization and disturbance compensation. To achieve nanometer-scale tracking precision, the enhanced adaptive hybrid controller is further developed. It uses real-time input and output data to update FHM, thus changing the feedforward controller to suit the on-site hysteresis character of the piezoelectric actuator. Finally, as to 3 cases of 50 Hz sinusoidal, multiple frequency sinusoidal and 50 Hz triangular trajectories tracking, experimental results demonstrate the efficiency of the proposed controllers. Especially, being only 0.35% of the maximum desired displacement, the maximum error of 50 Hz sinusoidal tracking is greatly reduced to 5.8 nm, which clearly shows the ultra-precise nanometer-scale tracking performance of the developed adaptive hybrid controller.
Resistance switch using metal nanogap electrodes in air
Authors: Suga Hiroshi , Horikawa Masayo , Kumaragurubaran Somu , Furuta Shigeo , Masuda Yuichiro , Shimizu Tetsuo , Naitoh Yasuhisa
Published: August 2012

Resistance switching in nanogap electrodes, the electrodes of which are made of platinum and gold, was investigated in air. The “off-to-on” transition in air was achieved by voltage sweeping enforced with a current-compliance operation that suppresses the overcurrent just after the change in tunneling resistance. It was also found that the applied voltages for the “on-to-off” resistance transition could be suppressed in air. These results imply that resistance switching is caused in air, and moreover, that the switching voltage is affected by the surroundings.
Nonlinear dissipation of circularly polarized Alfvén waves due to the beam-induced obliquely propagating waves
Authors: Nariyuki Y. , Hada T. , Tsubouchi K.
Published: August 2012

In the present study, the dissipation processes of circularly polarized Alfvén waves in solar wind plasmas including beam components are numerically discussed by using a 2-D hybrid simulation code. Numerical results suggest that the parent Alfvén waves are rapidly dissipated due to the presence of the beam-induced obliquely propagating waves, such as kinetic Alfvén waves. The nonlinear wave-wave coupling is directly evaluated by using the induction equation for the parent wave. It is also observed both in the 1-D and 2-D simulations that the presence of large amplitude Alfvén waves strongly suppresses the beam instabilities.
Rayleigh-Taylor-induced magnetic fields in laser-irradiated plastic foils
Authors: Manuel M. J.-E. , Li C. K. , Séguin F. H. , Frenje J. A. , Casey D. T. , Petrasso R. D. , Hu S. X. , Betti R. , Hager J. , Meyerhofer D. D. , Smalyuk V.
Published: August 2012

Experimental observations of magnetic fields generated by Rayleigh-Taylor growth in laser-irradiated planar foils are presented. X-ray and monoenergetic proton radiographic techniques were used to probe plastic foils with seeded surface perturbations at different times during the evolution. Protons deflected by fields in the target cause modulations in proton fluence at the seed wavelength of 120 μm. Path-integrated magnetic-field strengths were inferred from modulations in proton fluence using a discrete-Fourier-transform analysis technique and found to increase from 10 to 100 T-μm during linear growth. Electron thermal conduction was shown to be unaffected by Rayleigh-Taylor-induced magnetic fields during the linear growth phase.
Microfluidic mixing in a Y-junction open channel
Authors: Tan Jue Nee , Neild Adrian
Published: August 2012

In the laminar regimes typical of microfluidic systems’, mixing is governed by molecular diffusion; however this process is slow in nature. Consequently, passive or active methods are usually sought for effective mixing. In this work, open fluidic channels will be investigated; these channels are bounded on all but one face by an air/fluid interface. Firstly, it will be shown that flow in open channels can merge at a Y-junction in a stable manner; hence two fluids can be brought into contact with each other. Secondly, the mixing of these two fluids will be studied. At high flow rates (>300 μl/min) mixing occurs at the junction without need for additional intervention, this mixing is far swifter than can be expected from molecular diffusion. At lower flow rates, intervention is required. A major motivation for open fluidic channels is the ability to interact with the surrounding air environment; this feature is used to effect the desired mixing. It is shown that by blowing an air jet across the junction, shear stresses at the air/fluid interface causes a flow profile within the fluid inductive to rapid mixing of the fluids.
Community Development Corporations, Policy Networks, and the Rescaling of Community Development Advocacy
Authors: Scally Corianne Payton
Published: August 2012

Some argue that, as place-bound, development-oriented entities dependent upon capital, community development corporations (CDCs) are ineffective political agents beyond the boundaries of the disadvantaged neighborhoods they serve. In response I ask: how have CDCs worked through policy networks to rescale the ‘spaces of engagement’ for community development policy beyond the local? Data gathered through document analysis, a survey, and interviews point to three distinct phases of the CDC rescaling project: (1) linking the local through a national network; (2) expanding spaces of engagement through state policy networks; and (3) a national network of networks. CDC policy networks have had uneven success in establishing their legitimacy, proving CDC effectiveness as agents of local economic development, overcoming ‘militant particularisms’, and mobilizing both the state and capital. CDCs can expand their spaces of engagement beyond the local through policy networks if they successfully develop boundary-spanning relations, defend their place-based agenda, combat essentialization through performance measurement, strengthen their state networks, and reimagine their national rescaling project.
The Transnational Regime Complex for Climate Change
Authors: Abbott Kenneth W
Published: August 2012

In climate change, as in other areas, recent years have produced a ‘Cambrian explosion’ of transnational institutions, standards, financing arrangements, and programs. As a result, climate governance has become complex, fragmented, and decentralized, operating without central coordination. Most studies of climate governance focus on inter state institutions. In contrast, I map a different realm of climate change governance: the diverse array of transnational schemes. I analyze this emerging system in terms of two theoretical frameworks developed to describe, explain, and evaluate complex governance arrangements—regime complex theory and polycentric governance theory—revealing fruitful avenues for positive and normative research. I conclude by arguing that the benefits of institutional complexity could be increased, and the costs reduced, through nonhierarchical ‘orchestration’ of climate change governance, in which international organizations or other appropriate authorities support and steer transnational schemes that further global public interests.
Building Environmental Governance in Bosnia-Herzegovina: Europeanisation and Transnational Assistance in the Context of Limited Statehood
Authors: Fagan Adam
Published: August 2012

With this paper I seek to identify the conditions under which a shift occurs from hierarchical decision making towards new modes of environmental governance in a case of weak statehood (Bosnia-Herzegovina), where an external agency (the EU) exerts significant influence alongside foreign consultants and international financial institutions (the European Bank for Reconstruction and Development—EBRD). The Environmental Impact Assessments (EIAs) undertaken as part of the development of the trans-European road network across the country are used here as case studies for examining emerging patterns of environmental governance in a state under the shadow of EU conditionality. The data suggest that whilst over a period of time the adoption of new EU-compliant formal procedures and frameworks (eg, EIA laws) does seem to be generating new modes of governance interaction and citizen involvement, the impact is contingent upon the critical didactic role played by (in this case) the EBRD in making the formal procedures effective and in building knowledge capacity within the state administration. Thus, a simple correlation between EU conditionality and substantive political change cannot be assumed, particularly where state agencies possess limited policy knowledge and nonstate actors (environmental NGOs) lack mobilisation capacity.
Shallow or Deep Europeanisation? The Uneven Impact of EU Cohesion Policy on the Regional and Local Authorities in Poland
Authors: Dąbrowski Marcin
Published: August 2012

With this paper I aim at refining the understanding of mechanisms of postaccession Europeanisation in the new member states by investigating the impact of EU cohesion policy on the Polish subnational policy actors involved in its implementation. Drawing on recent empirical evidence on the influence of EU cohesion policy in three areas—administrative capacity, strategic planning, and governance—I show that adjustment to the EU cohesion policy norms initially tends to be stimulated by cost–benefit calculation or constraint, which may involve ‘shallow’ adjustment. However, the study also reveals that over time, provided that EU-imported norms are in line with the actors' preferences, socialisation and learning mechanisms become more prominent. Moreover, I demonstrate that the subnational impact of EU cohesion policy remains uneven and differentiated depending on the actors' preferences, attitudes, and capacity.
Development of bovine embryos derived from reproductive techniques
Authors: Alberto Míryan L. V. , Meirelles Flavio V. , Perecin Felipe , Ambrósio Carlos E. , Favaron Phelipe O. , Franciolli André L. R. , Mess Andrea M. , dos Santos José M. , Rici Rose E. G. , Bertolini Marcelo , Miglino Maria A.
Published: August 2012

Assisted reproduction techniques have improved agricultural breeding in the bovine. However, important development steps may differ from the situation in vivo and there is a high mortality rate during the first trimester of gestation. To better understand these events, we investigated the development of embryos and fetal membranes following fixed-time AI (FTAI), IVF and nuclear transfer (NT). The onset of yolk-sac development was not normal in cloned embryos. Later steps differed from conditions in vivo in all three groups; the yolk-sac was yellowish and juxtaposed with the amniotic membrane. Vascularisation of the chorioallantoic membrane was relatively late and low in NT gestations, but normal in the others. The overall development of the embryos was normal, as indicated by morphology and regression analysis of growth rate. However, NT conceptuses were significantly smaller, with the livers in some embryos occupying the abdominal cavity and others exhibiting heart abnormalities. In conclusion, the yolk-sac and the cardiovascular system seem to be vulnerable to morphogenetic alterations. Future studies will focus on gene expression and early vascularisation processes to investigate whether these changes may be responsible for the high incidence of intrauterine mortality, especially in clones.
Follicular fluid leptin concentrations and expression of leptin and leptin receptor in the equine ovary and in vitro-matured oocyte with reference to pubertal development and breeds
Authors: Lange-Consiglio Anna , Arrighi Silvana , Fiandanese Nadia , Pocar Paola , Aralla Marina , Bosi GiamPaolo , Borromeo Vitaliano , Berrini Anna , Meucci Aurora , Dell'Aquila Maria E. , Cremonesi Fausto
Published: August 2012

There is no published information about follicular-fluid leptin concentrations or the presence of leptin and leptin receptor in the equine ovary or oocyte. Three groups of mares – adult draft mares, draft fillies and adult Standardbred mares – were included in the study. Leptin and leptin receptor were detected in all immature oocytes by immunofluorescence with higher intensity in oocytes from draft mares compared with draft fillies and Standardbred mares. After in vitro maturation a higher proportion of oocytes reached metaphase II in draft mares than in draft fillies and Standardbred mares, and in all groups both leptin and leptin receptor became localised in the oocyte cortex but with higher immunopositivity in draft mares compared with draft fillies and Standardbred mares. These intensities were confirmed by the expression profiles of leptin and leptin receptor mRNA. Moreover, leptin was detected in ovarian blood vessels in all three types of animal and within the corpora lutea in adult mares. Serum and follicular-fluid concentrations of leptin were similar in draft and Standardbred mares but higher in draft mares than in draft fillies. This study supports the hypothesis that expression of leptin and leptin receptor mRNA and the rate of maturation can be related either to adiposity or to puberty.
Describing wildland surface fuel loading for fire management: a review of approaches, methods and systems
Authors: Keane Robert E.
Published: August 2012

Wildland fuelbeds are exceptionally complex, consisting of diverse particles of many sizes, types and shapes with abundances and properties that are highly variable in time and space. This complexity makes it difficult to accurately describe, classify, sample and map fuels for wildland fire research and management. As a result, many fire behaviour and effects software prediction systems use a generalised description of fuels to simplify data collection and entry into various computer programs. There are several major fuel description systems currently used in the United States, Canada and Australia, and this is a source of confusion for many in fire management. This paper (1) summarises the challenges of describing fuels, (2) contrasts approaches (association, classification and abstraction) for developing fuel description systems and (3) discusses possible future directions in wildland fuel description and science to transition to a universal fuel description system. Most discussion centres on surface fuel loadings as the primary descriptive characteristic. This synthesis paper is intended to provide background for understanding surface fuel classification and description systems and their use in simulating fire behaviour and effects, quantifying carbon inventories and evaluating site productivity.
Antibodies and IL-3 support helminth-induced basophil expansion
Authors: Herbst Tina , Esser Julia , Prati Moira , Kulagin Manuel , Stettler Rebecca , Zaiss Mario M. , Hewitson James P. , Merky Patrick , Verbeek Joseph S. , Bourquin Carole , Camberis Mali , Prout Melanie , Maizels Rick M. , Le Gros Graham , Harris Nicola L.
Published: August 2012

Basophils are powerful mediators of Th2 immunity and are present in increased numbers during allergic inflammation and helminth infection. Despite their ability to potentiate Th2 immunity the mechanisms regulating basophil development remain largely unknown. We have found a unique role for isotype-switched antibodies in promoting helminth-induced basophil production following infection of mice withHeligmosomoides polygyrus bakeriorNippostrongylus brasiliensis.H. polygyrus bakeri-induced basophil expansion was found to occur within the bone marrow, and to a lesser extent the spleen, and was IL-3 dependent. IL-3 was largely produced by CD4+CD49b+NK1.1−effector T cells at these sites, and required the IL-4Rα chain. However, antibody-deficient mice exhibited defective basophil mobilization despite intact T-cell IL-3 production, and supplementation of mice with immune serum could promote basophilia independently of required IL-4Rα signaling. Helminth-induced eosinophilia was not affected by the deficiency in isotype-switched antibodies, suggesting a direct effect on basophils rather than through priming of Th2 responses. Although normal type 2 immunity occurred in the basopenic mice following primary infection withH. polygyrus bakeri, parasite rejection following challenge infection was impaired. These data reveal a role for isotype-switched antibodies in promoting basophil expansion and effector function following helminth infection.
Dynamics of the
l
-fucose/H
+
symporter revealed by fluorescence spectroscopy
Authors: Sugihara Junichi , Sun Linfeng , Yan Nieng , Kaback H. Ronald
Published: August 2012

FucP of
Escherichia coli
catalyzes
l
-fucose/H
+
symport, and a crystal structure in an outward-facing conformation has been reported. However, nothing is known about FucP conformational dynamics. Here, we show that addition of
l
-fucose to purified FucP in detergent induces ∼20% quenching of Trp fluorescence in a concentration-dependent manner without a shift in λ
max
. Quenching is essentially abolished when both Trp38 and Trp278, which are positioned on opposing faces of the outward-facing cavity walls, are replaced with Tyr or Phe, and reduced quenching is observed when either Trp is mutated. Therefore, both Trp residues are involved in the phenomenon. Furthermore, replacement of either Trp38 or Trp278, predominantly Trp38, causes decreased quenching, decreased apparent affinity for
l
-fucose, and significant inhibition of active
l
-fucose transport, indicating that the two residues are likely involved directly in sugar binding. It is proposed that sugar binding induces a conformational change in which the outward-facing cavity in FucP closes, thereby bringing Trp38 and Trp278 into close proximity around the bound sugar to form an “occluded” intermediate. The location of these two Trp residues provides a unique method for analyzing structural dynamics in FucP.
Gender differences in the incentive salience of adult and infant faces
Authors: Hahn Amanda C. , Xiao Dengke , Sprengelmeyer Reiner , Perrett David I.
Published: August 2012

Facial appearance can motivate behaviour and elicit activation of brain circuits putatively involved in reward. Gender differences have been observed for motivation to view beauty in adult faces—heterosexual women are motivated by beauty in general, while heterosexual men are motivated to view opposite-sex beauty alone. Although gender differences have been observed in sensitivity to infant cuteness, infant faces appear to hold equal incentive salience among men and women. In the present study, we investigated the incentive salience of attractiveness and cuteness in adult and infant faces, respectively. We predicted that, given alternative viewing options, gender differences would emerge for motivation to view infant faces. Heterosexual participants completed a “pay-per-view” key-press task, which allowed them to control stimulus duration. Gender differences were found such that infants held greater incentive salience among women, although both sexes differentiated infant faces based on cuteness. Among adult faces, men exerted more effort than women to view opposite-sex faces. These findings suggest that, contrary to previous reports, gender differences do exist in the incentive salience of infant faces as well as opposite-sex faces.
Trade-offs in visual attention and the enhancement of memory specificity for positive and negative emotional stimuli
Authors: Chipchase Susan Y. , Chapman Peter
Published: August 2012

Emotional influences on memory can lead to trade-offs in memory for gist or detail and trade-offs in memory for central or peripheral aspects of an event. Attentional narrowing has often been proposed as a theoretical explanation for this pattern of findings with negative emotion. These trade-offs have been less extensively investigated with positive emotion. In three experiments, we investigate memory for specific visual details of positive and negative stimuli, examine central–peripheral trade-offs in memory, and assess the hypothesis that attentional narrowing contributes to emotional enhancement of memory specificity. We found that memory for details was enhanced by negative and positive emotion. Central–peripheral trade-offs were found in memory for negative emotional stimuli but not in memory for positive emotional stimuli. These trade-offs with negative emotion were associated with attentional narrowing at the time of encoding, as measured by eye movements. There were no attentional effects at the time of encoding found with positive emotional stimuli. Evidence was found for the attentional narrowing hypothesis of memory specificity and central–peripheral trade-offs in memory for negative emotional events. Alternative explanations for the positive emotional enhancement of memory specificity are required.
Novel word integration in the mental lexicon: Evidence from unmasked and masked semantic priming
Authors: Tamminen Jakke , Gaskell M. Gareth
Published: August 2012

We sought to establish whether novel words can become integrated into existing semantic networks by teaching participants new meaningful words and then using these new words as primes in two semantic priming experiments, in which participants carried out a lexical decision task to familiar words. Importantly, at no point in training did the novel words co-occur with the familiar words that served as targets in the primed lexical decision task, allowing us to evaluate semantic priming in the absence of direct association. We found that familiar words were primed by the newly related novel words, both when the novel word prime was unmasked (Experiment 1) and when it was masked (Experiment 2), suggesting that the new words had been integrated into semantic memory. Furthermore, this integration was strongest after a 1-week delay and was independent of explicit recall of the novel word meanings: Forgetting of meanings did not attenuate priming. We argue that even after brief training, newly learned words become an integrated part of the adult mental lexicon rather than being episodically represented separately from the lexicon.
Liquid crystal anchoring utilizing surface topological effects of self-structured dual-groove patterns
Authors: Park Chang-sub , Park Min-Kyu , Joo Kyung-Il , Park Ji-Sub , Park Kyung-Woo , Han Yeonjeong , Kang Shin-Won , Kim Hak-Rin
Published: August 2012

We demonstrate topologically patterned dual-groove surfaces for liquid crystal (LC) surface anchoring, where the dual-groove structure is made by a replica-moulding method from a self-structured poly(dimethylsiloxane) (PDMS) surface. In our method, the micro-groove structure with a periodicity on the order of micrometres is self-structured on the oxidized PDMS mould surface having a photolithographically defined macro-groove pattern owing to a thermally induced anisotropic stress effect. The direction of the micro-groove is determined to be perpendicular to the macro-groove direction and to form a mutually orthogonal dual-groove structure. With the presented method, the relative azimuth anchoring strength ratio (g) between the macro-groove and the micro-groove can be controlled precisely and easily. We investigated the LC anchoring effect created by the self-structured dual-groove pattern based on g, where the monostable LC anchoring surface is provided by the dual-groove surface with a g value close to 0 or infinity, and bistable LC anchoring is promoted as g approaches 1.
Modelling of the nanoscale channel length effect on the subthreshold characteristics of junctionless field-effect transistors with a symmetric double-gate structure
Authors: Jin Xiaoshi , Liu Xi , Wu Meile , Chuai Rongyan , Lee Jung-Hee , Lee Jong-Ho
Published: August 2012

An analytical subthreshold current of deep nanoscale short channel junctionless field-effect transistors (JL FETs) with a symmetric double-gate (DG) structure has been proposed. It is derived from two-dimensional Poisson's equation using a variable separation technique. The proposed models can exactly describe the behaviour of subthreshold I–V characteristics with nanoscale channel length without any empirical fitting parameter. The model accounts for channel length, body thickness, gate oxide thickness and body doping concentrations. The models are verified by comparison with TCAD simulations and show good agreement.