bluuebunny/crossref_metadata_2025 huggingface dataset:
Strategic Control Over the Unhelpful Effects of Primed Social Categories and Goals
Authors: Webb Thomas L. , Sheeran Paschal , Gollwitzer Peter M. , Trötschel Roman
Published: July 2012

Social situations can, at times, have a detrimental influence on behavior (e.g., exposure to supermodels can make people dumb, certain social situations can prompt excessive alcohol consumption). Gaining control over such effects can be difficult because the situational influence often occurs outside conscious awareness. The present research investigates whether forming if-then plans or “implementation intentions” (Gollwitzer, 1999) can help people to strategically prevent unwanted social influences. Two experiments found that priming social categories (e.g., supermodels, Experiment 1) or social goals (e.g., socializing, Experiment 2) can have a detrimental impact on participants’ general knowledge (Experiment 1) and mental readiness to drink (Experiment 2), respectively. However, both experiments also showed that forming implementation intentions designed to ensure the effective mobilization of resources (Experiment 1) or to ignore temptation (Experiment 2) prevented social primes from influencing behavior. These findings suggest that if-then planning affords strategic control over unwanted social influences on action.
Skill tests of three‐dimensional tidal currents in a global ocean model: A look at the North Atlantic
Authors: Timko Patrick G. , Arbic Brian K. , Richman James G. , Scott Robert B. , Metzger E. Joseph , Wallcraft Alan J.
Published: July 2012

We present and apply several skill tests to assess tidal currents generated within a global ocean model compared to an archive of current meter records spanning 40 years. Within the North Atlantic we have identified over 1800 velocity records available for comparison to model output. The skill tests identify those regions where tidal ellipse parameters (semi‐major/minor axis, inclination and Greenwich phase) fall within 95% confidence intervals derived from observations. Additional skill tests examine the vertical and horizontal structure of the tidal currents using the correlation and root mean square error between the observations and model. The skill tests account for grid misrepresentation within the model by comparing model values in a local 9‐point neighborhood. Both the three‐dimensional structure of model tidal currents and barotropic model tidal currents are compared to the altimetry based barotropic model TPXO 7.2. Our results indicate that the non‐data assimilative ocean model performance is comparable to TPXO 7.2. The semi‐major axes of the semi‐diurnal constituents lie within the 95% confidence intervals between 40% and 60% of the time in some regions of the North Atlantic. The performance degrades when all tidal ellipse parameters are considered. Root mean square errors between the model and observations distributed through the water column are generally less than 1 cm s−1 representing an error of less than ∼10% for constituent M2. The model tides also exhibit high correlation with observations in the horizontal planes. The skill tests could be adapted to other sets of observations and other models.
Geometry and kinematic evolution of a long‐living foreland structure inferred from field data and cross section balancing, the Sainte‐Victoire System, Provence, France
Authors: Espurt Nicolas , Hippolyte Jean‐Claude , Saillard Marianne , Bellier Olivier
Published: July 2012

The Sainte‐Victoire System (SVS) is a key area to understand how the shortening is accommodated in outer foreland of the Pyrenean‐Provence orogen between Late Cretaceous and Eocene. Structural data, growth strata and fault slip analysis, and four balanced cross sections are used to decipher the along‐strike geometry, deformational characteristics and kinematics of the SVS. The SVS is divided into two structural domains separated by a regional relay zone: the eastern domain is governed by a N‐vergent thin‐skinned tectonic style above Triassic series and the western domain, by a mixed S‐vergent thick‐ and thin‐skinned tectonic style with tectonic inversion of Late Paleozoic‐Triassic half grabens. Growth strata indicate that the eastern SVS grew during Danian as a result of shortening transfer from the southern Arc Basin. In contrast, the western SVS is an independent structure which has recorded the early stage (∼83 Ma) of shortening and focused continuous deformation during ∼40 Myr. The shallow N‐S shortening is ∼5 km (∼25%) and ∼8 km (∼34%) in the western and eastern SVS, respectively. At a regional scale, the tectonic inversion of the SVS and the Arc Basin recorded a deep shortening of the order of 15–18 km (∼34%). Although the shortening magnitude of the SVS remains small, other structures similar to the SVS were synchronously active across foreland basin, suggesting a significant amount of cumulated shortening. This outer foreland shortening may account for a non‐negligible amount of deformation at the Pyrenean‐Provence orogen scale.
Field information links permafrost carbon to physical vulnerabilities of thawing
Authors: Harden Jennifer W. , Koven Charles D. , Ping Chien‐Lu , Hugelius Gustaf , David McGuire A. , Camill Phillip , Jorgenson Torre , Kuhry Peter , Michaelson Gary J. , O'Donnell Jonathan A. , Schuur Edward A. G. , Tarnocai Charles , Johnson Kristopher , Grosse Guido
Published: July 2012

Deep soil profiles containing permafrost (Gelisols) were characterized for organic carbon (C) and total nitrogen (N) stocks to 3 m depths. Using the Community Climate System Model (CCSM4) we calculate cumulative distributions of active layer thickness (ALT) under current and future climates. The difference in cumulative ALT distributions over time was multiplied by C and N contents of soil horizons in Gelisol suborders to calculate newly thawed C and N. Thawing ranged from 147 PgC with 10 PgN by 2050 (representative concentration pathway RCP scenario 4.5) to 436 PgC with 29 PgN by 2100 (RCP 8.5). Organic horizons that thaw are vulnerable to combustion, and all horizon types are vulnerable to shifts in hydrology and decomposition. The rates and extent of such losses are unknown and can be further constrained by linking field and modelling approaches. These changes have the potential for strong additional loading to our atmosphere, water resources, and ecosystems.
Minimum distribution of subsea ice‐bearing permafrost on the U.S. Beaufort Sea continental shelf
Authors: Brothers Laura L. , Hart Patrick E. , Ruppel Carolyn D.
Published: July 2012

Starting in Late Pleistocene time (∼19 ka), sea level rise inundated coastal zones worldwide. On some parts of the present‐day circum‐Arctic continental shelf, this led to flooding and thawing of formerly subaerial permafrost and probable dissociation of associated gas hydrates. Relict permafrost has never been systematically mapped along the 700‐km‐long U.S. Beaufort Sea continental shelf and is often assumed to extend to ∼120 m water depth, the approximate amount of sea level rise since the Late Pleistocene. Here, 5,000 km of multichannel seismic (MCS) data acquired between 1977 and 1992 were examined for high‐velocity (>2.3 km s−1) refractions consistent with ice‐bearing, coarse‐grained sediments. Permafrost refractions were identified along <5% of the tracklines at depths of ∼5 to 470 m below the seafloor. The resulting map reveals the minimum extent of subsea ice‐bearing permafrost, which does not extend seaward of 30 km offshore or beyond the 20 m isobath.
Sizing up the bubbles that produce very fine ash during explosive volcanic eruptions
Authors: Genareau Kimberly , Proussevitch Alexander A. , Durant Adam J. , Mulukutla Gopal , Sahagian Dork L.
Published: July 2012

Explosive volcanic eruptions emit large proportions of very fine ash (<30 μm) into the atmosphere, posing hazards to aviation, infrastructure, and human health. Here we present an analysis of bubble size distributions at the point of fragmentation during the 18 May 1980 eruption of MSH through the examination of simple ash particles in distally deposited fall samples. The external surfaces of individual fine ash grains preserve the morphology of the bubbles that burst to form the ash, so bubble sizes can be measured using stereo‐scanning electron microscopy. Simple ash particles are those that allow the measurement of a single vesicle imprint per individual grain. These simple ash particles are the finest component of the tephra, and can thus travel great distances from the source volcano. Analyses of samples provided bubble volume distributions with a dominant peak between 560 and 5600μm3, corresponding to equivalent vesicle diameter modes of 10–22 μm, and these values were consistent for all examined sample locations. Determination of syn‐eruptive bubble sizes thus makes it possible to glean information regarding conduit dynamics at the point of magma fragmentation from observed ash deposits, to parameterize numerical eruption models in ways not previously possible, and to quantify the size of bubbles that burst to create the ash component most hazardous to the aviation industry and human health.
Spatial distributions of the ion to electron temperature ratio in the magnetosheath and plasma sheet
Authors: Wang Chih‐Ping , Gkioulidou Matina , Lyons Larry R. , Angelopoulos Vassilis
Published: July 2012

We have used THEMIS measurements to determine how the ion and electron temperatures and their ratio (Ti/Te) change spatially in the magnetosheath and plasma sheet and to identify the processes responsible for the variations. Magnetosheath Ti/Te varies from ∼4–12 with higher ratios observed during larger solar wind speed and at locations closer to the magnetopause. Ti/Te remains almost unchanged as particles flow downstream and cool adiabatically. Across the flank magnetopause from the magnetosheath to a plasma sheet that is cool with abundant cold plasma, temperature and specific entropy for ions and electrons increase significantly while Ti/Teremains similar, indicating that the magnetosheath ions and electrons are non‐adiabatically energized with similar proportion while entering the magnetosphere. Within the tail plasma sheet, Ti/Te varies from ∼6 to 10 when plasma is relatively cool to ∼2 to 5 when relatively warm. With this correlation, Ti/Te is higher closer to the flanks and during northward interplanetary magnetic field (IMF), while lower Ti/Te is more often seen during higher AE around midnight. The distinguishably lower Ti/Tefor warmer plasma in the near‐Earth plasma sheet is likely due to additional non‐adiabatic heating of electrons more than ions as particles move earthward and are adiabatically energized. As particles move into the near‐Earth magnetosphere, strengthening magnetic drift brings more hotter ions toward dusk and more hotter electrons toward dawn, resulting in a strong Ti/Tedawn‐dusk asymmetry with very high Ti/Te (∼15 to 100) near dusk and very low Ti/Te (∼1) near dawn.
Observed and modeled surface eddy heat fluxes in the eastern Nordic Seas
Authors: Isachsen P. E. , Koszalka I. , LaCasce J. H.
Published: July 2012

Large‐scale budget calculations and numerical model process studies suggest that lateral eddy heat fluxes have an important cooling effect on the Norwegian Atlantic Current (NwAC) as it flows through the Nordic Seas. But observational estimates of such fluxes have been lacking. Here, wintertime surface eddy heat fluxes in the eastern Nordic Seas are estimated from surface drifter data, satellite data and an eddy‐permitting numerical model. Maps of the eddy heat flux divergence suggest advective cooling along the path of the NwAC. Integrating the flux divergence over temperature classes yields consistent estimates for the three data sets; the waters warmer than about 6°C are cooled while the cooler waters are warmed. Similar integrations over bottom depth classes show that regions shallower than about 2000 m are cooled while deeper regions are warmed. Finally, integrating the flux divergence along the core of the NwAC suggests that the highest eddy‐induced heat loss at the surface is along the steepest part of the continental slope, east of the Lofoten Basin. The model fields indicate that cooling of the current by lateral eddy fluxes is comparable to or larger than the local heat loss to the atmosphere.
Sediment transport by runoff on debris‐mantled dryland hillslopes
Authors: Michaelides Katerina , Martin Gareth J.
Published: July 2012

Hillslopes supply sediment to river channels, and therefore impact drainage basin functioning and evolution. The relationship between hillslope attributes and sediment flux forms the basis of geomorphic transport laws used to model the long‐term topographic evolution of drainage basins, but their specific interactions during individual storm events are not well understood. Runoff‐driven erosion of coarse particles, prevalent in dryland environments, presents a particular set of conditions for sediment transport that is poorly resolved in current models. In order to address this gap, we developed a particle‐based, force‐balance model for sheetwash sediment transport on coarse, debris‐mantled hillslopes within a rainfall‐runoff model. We use the model to examine how the interplay between hillslope attributes (gradient, length and grain size distribution) and runoff characteristics affects sediment transport, grain‐size changes on the hillslope, and sediment supply to the slope base. The relationship between sediment flux and hillslope gradient was found to transition from linear above a threshold to sigmoidal depending on hillslope length, initial grain sizes, and runoff characteristics. Grain sizes supplied to the slope base vary in a complex manner with hillslope attributes but an overall coarsening of the hillslopes is found to occur with increasing gradient, corroborating previous findings from field measurements. Intense, short duration storms result in within‐hillslope sediment redistribution and equifinality in sediment supply for different hillslope characteristics, which explain the lack of field evidence for any systematic relationships. Our model findings provide insights into hillslope responses to climatic forcing and have theoretical implications for modeling hillslope evolution in dry lands.
Magnetic properties of the seven-coordinated nanoporous framework material Co(bpy)1.5(NO3)2 (bpy = 4,4′-bipyridine)
Authors: Bartolomé Elena , Alonso Pablo Javier , Arauzo Ana , Luzón Javier , Bartolomé Juan , Racles Carmen , Turta Constantin
Published: July 2012

The hepta-coordinated Co(bpy)1.5(NO3)2 molecule exhibits a large crystal field induced anisotropy along its binary symmetry axis, as deduced from SQUID magnetometry, EPR, heat capacity measurements and ab initio simulations.
Comparison of collisional radiative models for edge electron density reconstruction from Li I (2s-2p) emission profiles
Authors: Stoschus H. , Thomas D. M. , Hudson B. , Muñoz Burgos J. M. , Schweinzer J.
Published: July 2012

Four collisional radiative models (CRMs) for reconstruction of the edge electron density profile from the measured Li I (2s-2p) emission profile of an accelerated lithium beam are compared using experimental data from DIII-D. It is shown for both L- and H-mode plasmas that edge density profiles reconstructed with the CRMs DDD2, ABSOLUT, [Sasaki et al. Rev. Sci. Instrum. 64, 1699 (1993)] and a new model developed at DIII-D agree in a density scan from neped = (2.0–6.5) × 1019 m−3 within 20%, 20%, <5%, and 40%, respectively, of the pedestal density measured with Thomson scattering. Profile shape and absolute density vary in a scan of the effective ion charge Zeff = 1–6 up to a factor of two but agree with Thomson data for Zeff = 1–2 within the error bars.
Ruddlesden-Popper faults in LaNiO3/LaAlO3 superlattices
Authors: Detemple E. , Ramasse Q. M. , Sigle W. , Cristiani G. , Habermeier H.-U. , Keimer B. , van Aken P. A.
Published: July 2012

Scanning transmission electron microscopy in combination with electron energy-loss spectroscopy is used to study LaNiO3/LaAlO3 superlattices grown on (La,Sr)AlO4 with varying single-layer thicknesses, which are known to control their electronic properties. The microstructure of the films is investigated on the atomic level and the role of observed defects is discussed in the context of the different properties. Two types of Ruddlesden-Popper faults are found, which are either two or three dimensional. The common planar Ruddlesden-Popper fault is induced by steps on the substrate surface. In contrast, the three-dimensionally arranged Ruddlesden-Popper fault, whose size is in the nanometer range, is caused by the formation of local stacking faults during film growth. Furthermore, the interfaces of the superlattices are found to show different sharpness, but the microstructure does not depend substantially on the single-layer thickness.
Nonradiative lifetimes in intermediate band photovoltaics—Absence of lifetime recovery
Authors: Krich Jacob J. , Halperin Bertrand I. , Aspuru-Guzik Alán
Published: July 2012

Intermediate band photovoltaics hold the promise of being highly efficient and cost effective photovoltaic cells. Intermediate states in the band gap, however, are known to facilitate nonradiative recombination. Much effort has been dedicated to producing metallic intermediate bands in hopes of producing lifetime recovery—an increase in carrier lifetime as doping levels increase. We show that lifetime recovery induced by the insulator-to-metal transition will not occur, because the metallic extended states will be localized by phonons during the recombination process. Only trivial forms of lifetime recovery, e.g., from an overall shift in intermediate levels, are possible. Future work in intermediate band photovoltaics must focus on optimizing subgap optical absorption and minimizing recombination, but not via lifetime recovery.
Mn-activated K2ZrF6 and Na2ZrF6 phosphors: Sharp red and oscillatory blue-green emissions
Authors: Kasa Ryota , Adachi Sadao
Published: July 2012

Mn-activated A2ZrF6 (A = K, Na) phosphors are synthesized by the chemical reaction method in HF-based solutions. The Mn-activated K2ZrF6 phosphor exhibits sharp red emission peaks at ∼630 nm, which are typically observed in various Mn4+-activated phosphors. The phosphor is, therefore, identified to be K2ZrF6:Mn4+. The Mn-activated Na2ZrF6 phosphor, on the other hand, shows a broad blue-green emission band with a peak at ∼520 nm while exhibiting an oscillatory feature. This emission band is considered to originate from the Mn2+ ion in the Na+−Na+ site of Na2ZrF6. Such an oscillatory feature has not been previously reported for phosphors. Fourier transform analysis yields a main oscillatory period of ∼0.10 eV together with a secondary oscillatory period of ∼26 meV. Although the origin of the oscillatory feature in Na2ZrF6:Mn2+ is unclear, it appears to be caused by an effect of the Mn2+-induced strain in the Na2ZrF6 host. Such unique luminescence properties of Na2ZrF6:Mn2+ are not only of technological importance but also of scientific interest.
Phantom instabilities in adiabatically driven systems: Dynamical sensitivity to computational precision
Authors: Hasan Jafri Haider , Umeshkanta Singh Thounaojam , Ramaswamy Ramakrishna
Published: July 2012

We study the robustness of dynamical phenomena in adiabatically driven nonlinear mappings with skew-product structure. Deviations from true orbits are observed when computations are performed with inadequate numerical precision for monotone, periodic, or quasiperiodic driving. The effect of slow modulation is to “freeze” orbits in long intervals of purely contracting or purely expanding dynamics in the phase space. When computations are carried out with low precision, numerical errors build up phantom instabilities which ultimately force trajectories to depart from the true motion. Thus, the dynamics observed with finite precision computation shows sensitivity to numerical precision: the minimum accuracy required to obtain “true” trajectories is proportional to an internal timescale that can be defined for the adiabatic system.
Optical energy optimization at the nanoscale by near-field interference
Authors: Koene Benny , Savoini Matteo , Kimel Alexey V. , Kirilyuk Andrei , Rasing Theo
Published: July 2012

Employing plasmonic antennas for subdiffraction focusing of light on recording media requires to take into account the complete structure of the medium, including dielectric cover layers. We find, with finite difference time domain simulations, that optical energy transfer to the magnetic recording layer is most efficient for an off-resonant antenna. Furthermore, we show that the focal spot in the magnetic film is well below the diffraction limit, making nanoscale all-optical magnetic data recording achievable.
Temperature enhancement of terahertz responsivity of plasma field effect transistors
Authors: Klimenko Oleg A. , Knap Wojciech , Iniguez Benjamin , Coquillat Dominique , Mityagin Yury A. , Teppe Frederic , Dyakonova Nina , Videlier Hadley , But Dmitry , Lime Francois , Marczewski Jacek , Kucharski Krzysztof
Published: July 2012

Temperature dependence of THz detection by field effect transistors was investigated in a wide range of temperatures from 275 K down to 5 K. The important increase of the photoresponse following 1/T functional dependence was observed when cooling from room temperature down to 30 K. At the temperatures below ∼30 K, the THz response saturated and stayed temperature independent. Similar behavior was observed for GaAs, GaN, and Si based field effect transistors. The high temperature data were successfully interpreted using recent theory of overdamped plasma excitation in field effect transistors. The low temperature saturation of the photoresponse was tentatively explained by the change of the transport regime from diffusive to ballistic or traps governed one. Our results clearly show that THz detectors based on field effect transistors may improve their responsivity with lowering temperature but in the lowest temperatures (below ∼30 K) further improvement is hindered by the physics of the electron transport itself.
Frequency multiplying oscillator with an electron beam accelerated in a drift space
Authors: Jang Kyu-Ha , Lee Kitae , Hee Park Seong , Miginsky S. , Uk Jeong Young
Published: July 2012

In a uniform acceleration region, the behavior of a velocity-modulated electron beam has been analyzed using a particle-in-cell code. By making use of one of the accelerated harmonic components of the velocity-modulated electron beam, we demonstrate a frequency multiplying oscillator for a compact THz emitter, which employs multiple electron beams and a higher order mode resonator to modulate the electron beam without an additional driving source.
Mechanism-independent method for predicting response to multidrug combinations in bacteria
Authors: Wood Kevin , Nishida Satoshi , Sontag Eduardo D. , Cluzel Philippe
Published: July 2012

Drugs are commonly used in combinations larger than two for treating bacterial infection. However, it is generally impossible to infer directly from the effects of individual drugs the net effect of a multidrug combination. Here we develop a mechanism-independent method for predicting the microbial growth response to combinations of more than two drugs. Performing experiments in both Gram-negative (
Escherichia coli)
and Gram-positive (
Staphylococcus aureus
) bacteria, we demonstrate that for a wide range of drugs, the bacterial responses to drug pairs are sufficient to infer the effects of larger drug combinations. To experimentally establish the broad applicability of the method, we use drug combinations comprising protein synthesis inhibitors (macrolides, aminoglycosides, tetracyclines, lincosamides, and chloramphenicol), DNA synthesis inhibitors (fluoroquinolones and quinolones), folic acid synthesis inhibitors (sulfonamides and diaminopyrimidines), cell wall synthesis inhibitors, polypeptide antibiotics, preservatives, and analgesics. Moreover, we show that the microbial responses to these drug combinations can be predicted using a simple formula that should be widely applicable in pharmacology. These findings offer a powerful, readily accessible method for the rational design of candidate therapies using combinations of more than two drugs. In addition, the accurate predictions of this framework raise the question of whether the multidrug response in bacteria obeys statistical, rather than chemical, laws for combinations larger than two.
Modelling enemy release during range expansion of
Ilex aquifolium
with a two-component GLMM.
Authors: Thiele J. , Markussen B.
Published: July 2012

In this worked example, we present a two-component generalized linear mixed model (GLMM) modelling a counting response with exceedingly many zeros. The emphasis will be on model construction and validation. To our knowledge only ADMB (if the likelihood functions are coded directly) and the GLIMMIX procedure in SAS allows for a flexible modelling of two-component GLMMs, so the statistical analysis will be done in SAS V9.2. However, the analysis did not proceed as smoothly as we hoped, and we comment on some of the problems we encountered. This forms Supplement C to Thiele J, Markussen B. Potential of GLMM in modelling invasive spread.
Laser-assisted water condensation in the atmosphere: a step towards modulating precipitation?
Authors: Kasparian J , Rohwetter P , Wöste L , Wolf J-P
Published: July 2012

We review the recent results about laser-induced condensation based on self-guided filaments generated by ultrashort laser pulses. After recalling the physico-chemistry of cloud particle formation in the atmosphere and the physics of laser filamentation, we discuss experimental results on laser-induced condensation and its relevance for modulating precipitation.
Control-oriented modelling for neoclassical tearing mode stabilization via minimum-seeking techniques
Authors: Wehner W. , Schuster E.
Published: July 2012

Suppression of magnetic islands driven by the neoclassical tearing mode (NTM) is necessary for efficient and sustained operation of tokamak fusion reactors. Compensating for the lack of bootstrap current, due to the pressure profile flattening in the magnetic island, by a localized electron cyclotron current drive (ECCD) has been proved experimentally as an effective method to stabilize NTMs. The effectiveness of this method is limited in practice by the uncertainties in the width of the island, the relative position between the island and the beam, and the ECCD power threshold for NTM stabilization. Heuristic search and suppress algorithms have been proposed and shown effective in improving the alignment of the ECCD beam with the island, using only an estimate of the island width. Making use of this estimate, real-time, non-model-based, extremum-seeking optimization algorithms have also been proposed not only for beam steering but also for power modulation in order to minimize the island-beam misalignment and the time required for NTM stabilization. A control-oriented dynamic model for the effect of ECCD on the magnetic island is proposed in this work to enable both control design and performance analysis of these minimum-seeking type of controllers. The model expands previous work by including the impact of beam modulation parameters such as the island-beam phase mismatch and the beam duty-cycle on the island width dynamics.
Control of neoclassical tearing modes
Authors: Maraschek M.
Published: July 2012

Neoclassically driven tearing modes (NTMs) are a major problem for tokamaks operating in a conventional ELMy H-mode scenario. Depending on the mode numbers these pressure-driven perturbations cause a mild reduction in the maximum achievable β
N = β
t/(I
p/a
B
t) before the onset of the NTM, or can even lead to disruptions at a low edge safety factor, q
95. A control of these types of modes in high β
N plasmas is therefore of vital interest for magnetically confined fusion plasmas. The control consists of two major approaches, namely the control of the excitation of these modes and the removal, or at least mitigation, of these modes, once an excitation could not be avoided. For both routes examples will be given and the applicability of these approaches to ITER will be discussed.
Studies on neutral beam ion confinement and excitation of beta-induced Alfvén acoustic eigenmodes in the HL-2A tokamak
Authors: Yi Liu , Mitsutaka Isobe , Xiao-Dong Peng , Hao Wang , Xiao-Quan Ji , Wei Chen , Yi-Po Zhang , Yun-Bo Dong , Shigeru Morita , Kazuo Toi , Xu-Ru Duan
Published: July 2012

Experiments with high-energy deuterium neutral beam (NB) injection were performed on the HL-2A tokamak. To obtain information on NB deposition and the slowing down of beam ions in HL-2A plasmas, very short-pulse deuterium NB injection, or the so-called ‘blip’ injection, was applied to MHD-quiescent ohmic deuterium plasmas. Analysis of neutron decay following the NB ‘blip’ injection indicates that tangentially injected beam ions are well confined, slowing down classically in the HL-2A tokamak. In contrast to the MHD-quiescent plasma, anomalous losses of beam ions were observed when a core-localized mode with a frequency up-chirping from 15 to 40 kHz appeared in the plasma. The core-localized mode was identified as a beta-induced Alfvén acoustic (BAAE) mode by its frequency sweeping behaviour and numerical calculation. Such a high energetic particle driven mode led to fast-ion loss, showing the strong influence of the core-localized fast-ion-driven BAAE mode on the fast-ion transport. Furthermore, a clear frequency splitting was first observed on the Alfvén-acoustic-type mode, and is found to be strongly linked to the effect of resonant wave–particle interaction, providing further insights into how frequency splitting structures are generated in the plasma.
Physics of resistive wall modes
Authors: Igochine V.
Published: July 2012

The advanced tokamak regime is a promising candidate for steady-state tokamak operation which is desirable for a fusion reactor. This regime is characterized by a high bootstrap current fraction and a flat or reversed safety factor profile, which leads to operation close to the pressure limit. At this limit, an external kink mode becomes unstable. This external kink is converted into the slowly growing resistive wall mode (RWM) by the presence of a conducting wall. Reduction of the growth rate allows one to act on the mode and to stabilize it. There are two main factors which determine the stability of the RWM. The first factor comes from external magnetic perturbations (error fields, resistive wall, feedback coils, etc). This part of RWM physics is the same for tokamaks and reversed field pinch configurations. The physics of this interaction is relatively well understood and based on classical electrodynamics. The second ingredient of RWM physics is the interaction of the mode with plasma flow and fast particles. These interactions are particularly important for tokamaks, which have higher plasma flow and stronger trapped particle effects. The influence of the fast particles will also be increasingly more important in ITER and DEMO which will have a large fraction of fusion born alpha particles. These interactions have kinetic origins which make the computations challenging since not only particles influence the mode, but also the mode acts on the particles. Correct prediction of the ‘plasma–RWM’ interaction is an important ingredient which has to be combined with external field's influence (resistive wall, error fields and feedback) to make reliable predictions for RWM behaviour in tokamaks. All these issues are reviewed in this paper.
Influence of rotating resonant magnetic perturbation on the plasma radial electric field on TEXTOR
Authors: Zhang T. , Liang Y. , Sun Y. , Krämer-Flecken A. , Soldatov S. , Nardon E. , Tamain P. , Waelbroeck F.L. , Yang Y. , Pearson J. , Koslowski H.R.
Published: July 2012

The plasma radial electric field (E

r
) has been changed by applying an n = 1 counter-rotating resonant magnetic perturbation (RMP) field with a frequency of 5 kHz in ohmic plasmas on TEXTOR. The change in the E

r
(ΔE

r
) is negative, different from the observations in previous experiments where ΔE

r
was always positive when a static or low frequency (∼1 kHz) rotating RMP field was applied in the plasma on TEXTOR. The E

r
profile in the present experiment shows two distinct evolution stages. In the first stage, ΔE

r
from the q = 2 to q = 3 surfaces have a similar decrease as the amplitude of the 5 kHz counter-rotating field increases. In the second stage, the decrease rate of ΔE

r
is faster for the positions closer to the q = 2 surface. As a result, the E

r
around the q = 2 surface has a significant change in this second stage while no change of E

r
is observed near the q = 3 surface even after the excitation of an m/n = 2/1 tearing mode. A reduced MHD code, 4FC, has been used to model the experiment. Two simulations have been performed. The first one is by applying a single 2/1 perturbation while both, 2/1 and 3/1 perturbations, have been applied in the second simulation. The result from the second simulation is qualitatively consistent with the experimental observations while the first simulation including only a single 2/1 perturbation cannot explain the evolution of the E

r
profile in the second stage as observed in the experiment.
Troponin I in acute decompensated heart failure: insights from the ASCEND‐HF study
Authors: Felker G. Michael , Hasselblad Vic , Tang W.H. Wilson , Hernandez Adrian F. , Armstrong Paul W. , Fonarow Gregg C. , Voors Adriaan A. , Metra Marco , McMurray John J.V. , Butler Javed , Heizer Gretchen M. , Dickstein Kenneth , Massie Barry M. , Atar Dan , Troughton Richard W. , Anker Stefan D. , Califf Robert M. , Starling Randall C. , O'Connor Christopher M.
Published: July 2012

Aims

We examined the prognostic importance of cardiac troponin I (cTnI) in a cohort of patients enrolled in the ASCEND‐HF study of nesiritide in acute decompensated heart failure (ADHF). Circulating troponins are a prognostic marker in patients with ADHF. Contemporary assays with greater sensitivity require reassessment of the significance of troponin elevation in HF.

Methods and results

Cardiac troponin I was measured in a core laboratory in 808 ADHF patients enrolled in the ASCEND‐HF biomarkers substudy using a sensitive assay (VITROS Trop I ES, Ortho Clinical Diagnostics) with a lower limit of detection of 0.012 ng/mL and a 99th percentile upper reference limit (URL) of 0.034 ng/mL. Patients with clinical evidence of acute coronary syndrome or troponin >5× the URL were excluded. Multivariable modelling was used to assess the relationship between log(cTnI) and in‐hospital and post‐discharge outcomes. Baseline cTnI was undetectable in 22% and elevated above the 99th percentile URL in 50% of subjects. cTnI levels did not differ based on HF aetiology. After multivariable adjustment, higher cTnI was associated with worsened in‐hospital outcomes such as length of stay (P = 0.01) and worsening HF during the index hospitalization (P = 0.01), but was not associated with worsened post‐discharge outcomes at 30 or 180 days. The relationship between cTnI and outcomes was generally linear and there was no evidence of a threshold effect at any particular level of cTnI.

Conclusion

cTnI is elevated above the 99th percentile URL in 50% of ADHF patients and predicts in‐hospital outcome, but is not an independent predictor of long‐term outcomes.
High leptin and resistin expression in chronic heart failure: adverse outcome in patients with dilated and inflammatory cardiomyopathy
Authors: Bobbert Peter , Jenke Alexander , Bobbert Thomas , Kühl Uwe , Rauch Ursula , Lassner Dirk , Scheibenbogen Carmen , Poller Wolfgang , Schultheiss Heinz‐Peter , Skurk Carsten
Published: July 2012

Aim

The expression of leptin and resistin is known to be positively correlated with the incidence of chronic heart failure (CHF). Both adipokines have been implicated in immunomodulation and cardiac remodelling. Therefore, we performed for the first time a clinical study to elucidate the effects of leptin and resistin on progression of CHF in patients with non‐ischaemic dilated (DCM) and inflammatory (DCMi) cardiomyopathy.

Methods and results

For the clinical study 120 patients were divided into a control (n = 16), DCM (n = 52), and DCMi (n = 52) group to determine the effect of leptin and resistin on CHF progression. Nuclear factor‐κB (NF‐κB) activation, reactive oxygen species generation, and tumour necrosis factor‐α (TNF‐α) and interleukin‐6 (IL‐6) expression following adipokine exposition were determined in vitro in cardiomyocytes. Leptin and resistin systemic plasma levels and not cardiac expression were significantly elevated in patients with DCM (leptin, 13.12 ± 17.2 ng/mL, P < 0.05; resistin, 6.87 ± 2.25 ng/mL, P < 0.05) and DCMi (leptin, 13.63 ± 16 ng/mL, P < 0.05; resistin, 7.27 ± 2.2 ng/mL, P < 0.05) compared with the control group (leptin, 7.34 ± 5.7 ng/mL; resistin, 4.4 ± 1.18 ng/mL). A multivariate linear regression model revealed low leptin and resistin plasma levels as contributors for favourable cardiac functional parameters at 6‐month follow‐up independent of inflammatory conditions. Cell culture experiments in vitro showed leptin and resistin to be potent regulators of TNF‐α and IL‐6 expression in cardiomyocytes, leading to significantly increased redox stress in cardiac cells.

Conclusions

High leptin and resistin expression in patients with DCM and DCMi is associated with CHF progression, i.e. severe cardiac dysfunction, independent of immune responses.
Concessions of an alpha male? Cooperative defence and shared reproduction in multi-male primate groups
Authors: Snyder-Mackler Noah , Alberts Susan C. , Bergman Thore J.
Published: July 2012

By living in social groups with potential competitors, animals forgo monopolizing access to resources. Consequently, debate continues over how selection might favour sociality among competitors. For example, several models exist to account for the evolution of shared reproduction in groups. The ‘concession model’ hypothesizes that dominant reproducers benefit from the presence of subordinates, and hence tolerate some reproduction by subordinates. This mutual benefit to both dominants and subordinates may provide a foundation for the formation of social groups in which multiple members reproduce—a necessary step in the evolution of cooperation. To date, however, the concession model has received virtually no support in vertebrates. Instead, the vast majority of vertebrate data support ‘limited control models’, which posit that dominant reproducers are simply unable to prevent subordinates from reproducing. Here we present the most comprehensive evidence to date in support of the concession model in a vertebrate. We examined natural variation in the number of adult males in gelada (
Theropithecus gelada
) reproductive units to assess the extent of reproductive skew in multi-male units. Dominant (‘leader’) males in units that also had subordinate (‘follower’) males had a 30 per cent longer tenure than leaders in units that did not have followers, mainly because followers actively defended the group against potential immigrants. Follower males also obtained a small amount of reproduction in the unit, which may have functioned as a concession in return for defending the unit. These results suggest that dominants and subordinates may engage in mutually beneficial reproductive transactions, thus favouring male–male tolerance and cooperation.
An economic experiment reveals that humans prefer pool punishment to maintain the commons
Authors: Traulsen Arne , Röhl Torsten , Milinski Manfred
Published: July 2012

Punishment can stabilize costly cooperation and ensure the success of a common project that is threatened by free-riders. Punishment mechanisms can be classified into pool punishment, where the punishment act is carried out by a paid third party, (e.g. a police system or a sheriff), and peer punishment, where the punishment act is carried out by peers. Which punishment mechanism is preferred when both are concurrently available within a society? In an economic experiment, we show that the majority of subjects choose pool punishment, despite being costly even in the absence of defectors, when second-order free-riders, cooperators that do not punish, are also punished. Pool punishers are mutually enforcing their support for the punishment organization, stably trapping each other. Our experimental results show how organized punishment could have displaced individual punishment in human societies.
Identification of residues in West Nile virus pre-membrane protein that influence viral particle secretion and virulence
Authors: Setoh Y. X. , Prow N. A. , Hobson-Peters J. , Lobigs M. , Young P. R. , Khromykh A. A. , Hall R. A.
Published: July 2012

The pre-membrane protein (prM) of West Nile virus (WNV) functions as a chaperone for correct folding of the envelope (E) protein, and prevents premature fusion during virus egress. However, little is known about its role in virulence. To investigate this, we compared the amino acid sequences of prM between a highly virulent North American strain (WNVNY99) and a weakly virulent Australian subtype (WNVKUN). Five amino acid differences occur in WNVNY99compared with WNVKUN(I22V, H43Y, L72S, S105A and A156V). When expressed in mammalian cells, recombinant WNVNY99prM retained native antigenic structure, and was partially exported to the cell surface. In contrast, WNVKUNprM (in the absence of the E protein) failed to express a conserved conformational epitope and was mostly retained at the pre-Golgi stage. Substitutions in residues 22 (Ile to Val) and 72 (Leu to Ser) restored the antigenic structure and cell surface expression of WNVKUNprM to the same level as that of WNVNY99, and enhanced the secretion of WNVKUNprME particles when expressed in the presence of E. Introduction of the prM substitutions into a WNVKUNinfectious clone (FLSDX) enhanced the secretion of infectious particles in Vero cells, and enhanced virulence in mice. These findings highlight the role of prM in viral particle secretion and virulence, and suggest the involvement of the L72S and I22V substitutions in modulating these activities.
Nature and function of insulator protein binding sites in the Drosophila genome
Authors: Schwartz Yuri B. , Linder-Basso Daniela , Kharchenko Peter V. , Tolstorukov Michael Y. , Kim Maria , Li Hua-Bing , Gorchakov Andrey A. , Minoda Aki , Shanower Gregory , Alekseyenko Artyom A. , Riddle Nicole C. , Jung Youngsook L. , Gu Tingting , Plachetka Annette , Elgin Sarah C.R. , Kuroda Mitzi I. , Park Peter J. , Savitsky Mikhail , Karpen Gary H. , Pirrotta Vincenzo
Published: July 2012

Chromatin insulator elements and associated proteins have been proposed to partition eukaryotic genomes into sets of independently regulated domains. Here we test this hypothesis by quantitative genome-wide analysis of insulator protein binding to Drosophila chromatin. We find distinct combinatorial binding of insulator proteins to different classes of sites and uncover a novel type of insulator element that binds CP190 but not any other known insulator proteins. Functional characterization of different classes of binding sites indicates that only a small fraction act as robust insulators in standard enhancer-blocking assays. We show that insulators restrict the spreading of the H3K27me3 mark but only at a small number of Polycomb target regions and only to prevent repressive histone methylation within adjacent genes that are already transcriptionally inactive. RNAi knockdown of insulator proteins in cultured cells does not lead to major alterations in genome expression. Taken together, these observations argue against the concept of a genome partitioned by specialized boundary elements and suggest that insulators are reserved for specific regulation of selected genes.
Diosgenin hemihydrate
Authors: Hernández Linares María-Guadalupe , Bernès Sylvain , Flores-Alamo Marcos , Guerrero-Luna Gabriel , Martínez-Gallegos Anselmo A.
Published: July 2012

Diosgenin [or (22R,25R)-spirost-5-en-3β-ol] is the starting material of the Marker degradation, a cheap semi-synthesis of progesterone, which has been designated as an International Historic Chemical Landmark. Thus far, a single X-ray structure for diosgenin is known, namely its dimethyl sulfoxide solvate [Zhanget al.(2005).Acta Cryst.E61, o2324–o2325]. We have now determined the structure of the hemihydrate, C27H42O3·0.5H2O. The asymmetric unit contains two diosgenin molecules, with quite similar conformations, and one water molecule. Hydroxy groups in steroids and water molecules form O—H...O hydrogen-bondedR54(10) ring motifs. Fused edge-sharingR(10) rings form a backbone oriented along [100], which aggregates the diosgenin molecules in the crystal structure.
Diosgenone: a secondP21polymorph
Authors: Hernández Linares María-Guadalupe , Guerrero-Luna Gabriel , Bernès Sylvain , Flores-Alamo Marcos , Fernández-Herrera María A.
Published: July 2012

Diosgenone [(20S,22R,25R)-spirost-4-en-3-one, C27H40O3] has been proposed as a new therapeutic alternative for the treatment of malaria. The first X-ray structure report for diosgenone was by Piroet al.[(2002).Z. Naturforsch. Teil C,57, 947–950] in the space groupP21(Z′ = 2). We now report a new polymorph in the same space group, with two molecules in the asymmetric unit. Both molecules have similar conformations, characterized by a skewed envelopeAring, which contains the C=C bond conjugated with the ketone functionality at C3. The dimorphism results from a modification of the relative orientation of the molecules in the asymmetric unit: two independent molecules were arranged antiparallel in the Piro report, while they are parallel in the present determination.
Guanidinium hexaaquazinc(II) bis[tris(3-carboxypyridine-2-carboxylato)zincate]
Authors: Tabatabaee Masoumeh , Derikvand Zohreh , Attar Gharamaleki Jafar
Published: July 2012

In the title molecular salt, (CH6N3)1.30[Zn(H2O)6]0.35[Zn(C7H4NO4)3]2, the ZnIIatom (site symmetry 3) in the anion is coordinated by threeN,O-bidentate 3-carboxypyridine-2-carboxylate monoanions to generate afac-ZnN3O3octahedral coordination geometry. The guanidinium cation (the C atom has site symmetry 3) and the octahedral hexaaquazinc(II) dication (the Zn2+cation has site symmetry -3) are occupationally disordered in a 1.30:0.35 ratio. In the crystal, the components are linked by O—H...O and N—H...O hydrogen bonds to generate infinite (001) sheets. Weak aromatic π–π stacking [centroid–centroid distance = 3.797 (8) Å] is also observed in the crystal.
(R*)-Methyl 2-(2,6-dimethoxy-3,5-dinitrobenzamido)propanoate
Authors: Li Xiaofei , Tong Yan
Published: July 2012

In the title molecule, C13H15N3O9, the nitro groups are tilted with respect to the benzene mean plane by 22.8 (3) and 31.6 (3)°. The methoxy groups are in acisorientation relative to the ring. In the crystal, molecules are linked by strong N—H...O hydrogen bonds intoC(3) chains along [100].
Dilithium disodium nickel(II) cyclohexaphosphate dodecahydrate, Li2Na2NiP6O18·12H2O
Authors: Abid Sonia , Al-Deyab Salem S. , Rzaigui Mohamed
Published: July 2012

The crystal structure of Li2Na2NiP6O18·12H2O is characterized by the presence of six-membered P6O186−phosphate ring anions (internal symmetry -1) having a chair conformation and three different cations,viz.Li+, Na+and Ni2+, to counterbalance the anionic charge. All atoms are in general positions except for nickel, which lies on a special position with site symmetry 2. Lithium has a tetrahedral environment (LiO4), and sodium and nickel have octahedral environments [NaO6and Ni(H2O)6, respectively]. The P6O18rings are linkedviacorner sharing by NaO6octahedra and LiO4tetrahedra to form a three-dimensional framework presenting tunnels running along [010] in which the six-coordinated Ni2+cations are located. The structure is stabilized by a network of O—H...O hydrogen bonds.