bluuebunny/crossref_metadata_2025 huggingface dataset:
Balanced bandpass filter based on magnetically coupled coplanar waveguide folded‐stepped impedance resonators
Authors: Fernández‐Prieto A. , Bhatker J. , Lujambio A. , Martel J. , Medina F. , Boix R.R.
Published: May 2016

A novel balanced differential bandpass filter implemented in coplanar waveguide (CPW) technology is presented. The filter is based on the use of two magnetically coupled CPW folded‐stepped impedance resonators. The use of magnetic coupling, instead of the more common electric coupling, provides inherent common‐mode rejection. Measured and simulated results demonstrate the benefits of the proposed balanced filter.
Signal interference between CRLH TL and RH TL
Authors: Xiao Yang , Li Lin , Liu Gang , Cheng Wei
Published: May 2016

This Letter studies novel signal interference between composite right/left‐handed transmission line (CRLH‐TL) and right‐handed transmission line (RH‐TL). Theoretical study reveals that proposed innovative structure could not only realise conventional three transmission zeros bandstop response in minimised size but also provide bandpass and highpass filtering characteristic. Finally, a bandpass filter having a wide fractional bandwidth of 142% is implemented with very compact size of 42.27 mm × 26.76 mm. Theoretical predictions are well validated by corresponding measurements.
Radar classification of indoor targets using support vector machines
Authors: Bufler Travis D. , Narayanan Ram M.
Published: May 2016

Through‐the‐wall radar systems are typically plagued by harsh clutter which confounds the detection and classification of targets. This study approaches the problem of separating humans from indoor targets through machine learning techniques by implementing support vector machine (SVM) classifiers. Simulated and experimental data are used to evaluate the suitability of SVMs for target classification via their spectral characteristics. Numerical modelling of humans and indoor clutter was accomplished through the finite‐difference time‐domain (FDTD) method. The radar cross‐sections for the various objects are acquired over a wide range of frequencies, polarisations, aspect angles, and material properties. Furthermore, the spectral properties of humans and clutter targets are measured using a network analyser. The potentials of the acquired simulated and experimental spectral characteristics at different frequencies and polarisations are explored for target classification using SVMs. Feature selection algorithms are also investigated to reduce the redundancy and model complexity. Finally, the classification performance is assessed in the presence of additive white Gaussian noise and through various wall materials.
Effect of surfactant type on the synthesis of nanocrystalline MgAl2O4 and its application as a support for Ni catalyst in the steam pre‐reforming of natural gas
Authors: Keshavarz Ahmad Reza , Soleimani Mansooreh
Published: May 2016

Mesoporous nanocrystalline magnesium aluminate (MgAl2O4) particles with different surface area (70–230 m2 g−1) were synthesised via the homogeneous co‐precipitation method using different surfactants (cationic, anionic and non‐ionic). The obtained powders were used as the support to prepare 10.5 nickel (Ni)/MgAl2O4 catalysts, and the resulting samples were tested in the steam pre‐reforming of natural gas. The obtained samples were characterised by Fourier transform infrared spectroscopy, Brunauer‐Emmett‐Teller (BET), X‐ray diffraction, thermogravimetric/differential thermal analysis, transmission electron microscopy and temperature programmed desorption (TPD) techniques. Experimental results showed that the shape, surface area and porosity of MgAl2O4 particles were strongly dependent on the type of surfactants used. In addition, the Ni catalyst supported on the MgAl2O4 with the highest surface area exhibited the smallest size of Ni particles (14.1 nm). This catalyst has over 97% of ethane and propane conversions in steam pre‐reforming of natural gas under atmospheric pressure, 550°C, low steam to carbon molar ratio (S/C = 1.5) and high gas hourly space velocity (GHSV = 100,000 ml g−1catalyst h−1).
Bildarchivierung: Mit dem PACS die Zukunft planen
Authors: Emmerich Torsten
Published: May 2016

Im Gesundheitswesen verschwimmen die Grenzen zwischen einzelnen Fachbereichen und Abteilungen immer mehr. Fachbezogene IT-Systeme wie das Bildarchivierungs- und Kommunikationssystem (PACS) müssen sich diesem Wandel anpassen. Das geht nur, wenn sie in der Lage sind, über ihren ursprünglichen Zweck hinauszuwachsen.
Flucht planen: Licht leitet
Authors: Thalmayr Maria
Published: May 2016

Menschen streben instinktiv zum Licht. Dieses Verhaltensmuster könnten sich Fachplaner bei der Konzeption von Flucht- und Rettungswegen zu Nutze machen. „Bisher spielt die Lichtplanung im Brandschutz wie in der Krankenhausplanung allgemein jedoch kaum eine Rolle und wird, wenn überhaupt, zu spät in die Überlegungen mit einbezogen.“
1:0 für den Schiedsrichter
Authors: Wenzel Kirsten
Published: May 2016

Willensstärke und Dynamik: Natürlich treffen diese Manager-Eigenschaften auch auf den Chef der Paracelsus-Klinik Hemer zu. Doch sein Markenzeichen ist die Entscheidungsfreude. Und das hat einen guten Grund.
Tight Glycemic Control in the Pediatric Intensive Care Unit
Authors: Agus Michael , Soto-Rivera Carmen
Published: May 2016

Hyperglycemia is a common complication in critically ill, nondiabetic children. Four large pediatric randomized controlled trials of tight glycemic control (TGC) have been conducted to date with contradicting results. This review will highlight the design and outcomes of these trials and other relevant studies to provide an overview of the advantages and disadvantages of TGC for different populations at risk of hyperglycemia along with future directions for research.
Mean flow generation by Görtler vortices in a rotating annulus with librating side walls
Authors: Ghasemi V. Abouzar , Klein Marten , Harlander Uwe , Kurgansky Michael V. , Schaller Eberhard , Will Andreas
Published: May 2016

Time periodic variation of the rotation rate of an annulus induces in supercritical regime an unstable Stokes boundary layer over the cylinder side walls, generating Görtler vortices in a portion of a libration cycle as a discrete event. Numerical results show that these vortices propagate into the fluid bulk and generate an azimuthal mean flow. Direct numerical simulations of the fluid flow in an annular container with librating outer (inner) cylinder side wall and Reynolds-averaged Navier–Stokes (RANS) equations as diagnostic equations are used to investigate generation mechanism of the retrograde (prograde) azimuthal mean flow in the bulk. First, we explain, phenomenologically, how absolute angular momentum of the bulk flow is mixed and changed due to the propagation of the Görtler vortices, causing a new vortex of basin size. Then we investigate the RANS equations for intermediate time scale of the development of the Görtler vortices and for long time scale of the order of several libration periods. The former exhibits sign selection of the azimuthal mean flow. Investigating the latter, we predict that the azimuthal mean flow is proportional to the libration amplitude squared and to the inverse square root of the Ekman number and libration frequency and then confirms this using the numerical data. Additionally, presence of an upscale cascade of energy is shown, using the kinetic energy budget of fluctuating flow.
Photoionisation study of Xe.CF4 and Kr.CF4 van-der-Waals molecules
Authors: Alekseev V. A. , Garcia G. A. , Kevorkyants R. , Nahon L.
Published: May 2016

We report on photoionization studies of Xe.CF4 and Kr.CF4 van-der-Waals complexes produced in a supersonic expansion and detected using synchrotron radiation and photoelectron-photoion coincidence techniques. The ionization potential of CF4 is larger than those of the Xe and Kr atoms and the ground state of the Rg.CF4+ ion correlates with Rg+ (2P3/2) + CF4. The onset of the Rg.CF4+ signals was found to be only ∼0.2 eV below the Rg ionization potential. In agreement with experiment, complementary ab initio calculations show that vertical transitions originating from the potential minimum of the ground state of Rg.CF4 terminate at a part of the potential energy surfaces of Rg.CF4+, which are approximately 0.05 eV below the Rg+ (2P3/2) + CF4 dissociation limit. In contrast to the neutral complexes, which are most stable in the face geometry, for the Rg.CF4+ ions, the calculations show that the minimum of the potential energy surface is in the vertex geometry. Experiments which have been performed only with Xe.CF4 revealed no Xe.CF4+ signal above the first ionization threshold of Xe, suggesting that the Rg.CF4+ ions are not stable above the first dissociation limit.
Resolution-of-identity stochastic time-dependent configuration interaction for dissipative electron dynamics in strong fields
Authors: Klinkusch Stefan , Tremblay Jean Christophe
Published: May 2016

In this contribution, we introduce a method for simulating dissipative, ultrafast many-electron dynamics in intense laser fields. The method is based on the norm-conserving stochastic unraveling of the dissipative Liouville-von Neumann equation in its Lindblad form. The N-electron wave functions sampling the density matrix are represented in the basis of singly excited configuration state functions. The interaction with an external laser field is treated variationally and the response of the electronic density is included to all orders in this basis. The coupling to an external environment is included via relaxation operators inducing transition between the configuration state functions. Single electron ionization is represented by irreversible transition operators from the ionizing states to an auxiliary continuum state. The method finds its efficiency in the representation of the operators in the interaction picture, where the resolution-of-identity is used to reduce the size of the Hamiltonian eigenstate basis. The zeroth-order eigenstates can be obtained either at the configuration interaction singles level or from a time-dependent density functional theory reference calculation. The latter offers an alternative to explicitly time-dependent density functional theory which has the advantage of remaining strictly valid for strong field excitations while improving the description of the correlation as compared to configuration interaction singles. The method is tested on a well-characterized toy system, the excitation of the low-lying charge transfer state in LiCN.
Molecular dynamics at constant Cauchy stress
Authors: Miller Ronald E. , Tadmor Ellad B. , Gibson Joshua S. , Bernstein Noam , Pavia Fabio
Published: May 2016

The Parrinello-Rahman algorithm for imposing a general state of stress in periodic molecular dynamics simulations is widely used in the literature and has been implemented in many readily available molecular dynamics codes. However, what is often overlooked is that this algorithm controls the second Piola-Kirchhoff stress as opposed to the true (Cauchy) stress. This can lead to misinterpretation of simulation results because (1) the true stress that is imposed during the simulation depends on the deformation of the periodic cell, (2) the true stress is potentially very different from the imposed second Piola-Kirchhoff stress, and (3) the true stress can vary significantly during the simulation even if the imposed second Piola-Kirchhoff is constant. We propose a simple modification to the algorithm that allows the true Cauchy stress to be controlled directly. We then demonstrate the efficacy of the new algorithm with the example of martensitic phase transformations under applied stress.
Polymer gels with associating side chains and their interaction with surfactants
Authors: Gordievskaya Yulia D. , Rumyantsev Artem M. , Kramarenko Elena Yu.
Published: May 2016

Conformational behaviour of hydrophobically modified (HM) polymer gels in solutions of nonionic surfactants is studied theoretically. A HM gel contains hydrophobic side chains (stickers) grafted to its subchains. Hydrophobic stickers are capable to aggregate into joint micelles with surfactant molecules. Micelles containing more than one sticker serve as additional physical cross-links of the network, and their formation causes gel shrinking. In the proposed theoretical model, the interior of the gel/surfactant complex is treated as an array of densely packed spherical polymer brushes consisting of gel subchains tethered to the surface of the spherical sticker/surfactant micelles. Effect of stickers length and grafting density, surfactant concentration and hydrophobicity on gel swelling as well as on hydrophobic association inside it is analyzed. It is shown that increasing surfactant concentration can result in a gel collapse, which is caused by surfactant-induced hydrophobic aggregation of stickers, and a successive gel reswelling. The latter should be attributed to a growing fraction of surfactants in joint aggregates and, hence, increasing number of micelles containing only one sticker and not participating in gel physical cross-linking. In polyelectrolyte (PE) gels hydrophobic aggregation is opposed by osmotic pressure of mobile counterions, so that at some critical ionization degree hydrophobic association is completely suppressed. Hydrophobic modification of polymers is shown to open new ways for controlling gel responsiveness. In particular, it is discussed that incorporation of photosensitive groups into gel subchains and/or surfactant tail could give a possibility to vary the gel volume by light. Since hydrophobic aggregation regularities in gels and solutions are common, we hope our findings will be useful for design of polymer based self-healing materials as well.
Reduction method for representations of queer Lie superalgebras
Authors: Chen Chih-Whi
Published: May 2016

We develop a reduction procedure which provides an equivalence from an arbitrary block of the BGG category for the queer Lie superalgebra 𝔮(n) to a “ℤ ± s-weights” (s ∈ ℂ) block of a BGG category for finite direct sum of queer Lie superalgebras. We give descriptions of blocks. We also establish equivalences between certain maximal parabolic subcategories for 𝔮(n) and blocks of atypicality-one of the category of finite-dimensional modules for 𝔤𝔩(ℓ|n − ℓ).
Structural and electronic properties of UnOm (n=1-3,m=1-3n) clusters: A theoretical study using screened hybrid density functional theory
Authors: Yang Yu , Liu Haitao , Zhang Ping
Published: May 2016

The structural and electronic properties of small uranium oxide clusters UnOm (n=1-3, m=1-3n) are systematically studied within the screened hybrid density functional theory. It is found that the formation of U–O–U bondings and isolated U–O bonds are energetically more stable than U–U bondings. As a result, no uranium cores are observed. Through fragmentation studies, we find that the UnOm clusters with the m/n ratio between 2 and 2.5 are very stable, hinting that UO2+x hyperoxides are energetically stable. Electronically, we find that the O-2p states always distribute in the deep energy range, and the U-5f states always distribute at the two sides of the Fermi level. The U-6d states mainly hybridize with the U-5f states in U-rich clusters, while hybridizing with O-2p states in O-rich clusters. Our work is the first one on the screened hybrid density functional theory level studying the atomic and electronic properties of the actinide oxide clusters.
Quasi-linear gyrokinetic predictions of the Coriolis momentum pinch in National Spherical Torus Experiment
Authors: Guttenfelder W. , Kaye S. M. , Ren Y. , Solomon W. , Bell R. E. , Candy J. , Gerhardt S. P. , LeBlanc B. P. , Yuh H.
Published: May 2016

This paper presents quasi-linear gyrokinetic predictions of the Coriolis momentum pinch for low aspect-ratio National Spherical Torus Experiment (NSTX) H-modes where previous experimental measurements were focused. Local, linear calculations predict that in the region of interest (just outside the mid-radius) of these relatively high-beta plasmas, profiles are most unstable to microtearing modes that are only effective in transporting electron energy. However, sub-dominant electromagnetic and electrostatic ballooning modes are also unstable, which are effective at transporting energy, particles, and momentum. The quasi-linear prediction of transport from these weaker ballooning modes, assuming they contribute transport in addition to that from microtearing modes in a nonlinear turbulent state, leads to a very small or outward convection of momentum, inconsistent with the experimentally measured inward pinch, and opposite to predictions in conventional aspect ratio tokamaks. Additional predictions of a low beta L-mode plasma, unstable to more traditional electrostatic ion temperature gradient-trapped electron mode instability, show that the Coriolis pinch is inward but remains relatively weak and insensitive to many parameter variations. The weak or outward pinch predicted in NSTX plasmas appears to be at least partially correlated to changes in the parallel mode structure that occur at a finite beta and low aspect ratio, as discussed in previous theories. The only conditions identified where a stronger inward pinch is predicted occur either in the purely electrostatic limit or if the aspect ratio is increased. As the Coriolis pinch cannot explain the measured momentum pinch, additional theoretical momentum transport mechanisms are discussed that may be potentially important.
Active sites of ligand-protected Au25 nanoparticle catalysts for CO2 electroreduction to CO
Authors: Alfonso Dominic R. , Kauffman Douglas , Matranga Christopher
Published: May 2016

Recent experimental studies have reported the electrochemical reduction of carbon dioxide (CO2) into CO at atomically precise negatively charged Au25− nanoclusters. The studies showed CO2 conversion at remarkably low overpotentials, but the exact mechanisms and nature of the active sites remain unclear. We used first-principles density functional theory and continuum solvation models to examine the role of the cluster during electrochemical CO2 reduction and analyze the free energies of proposed intermediate species. Contrary to previous assumptions, our results show that the fully ligand protected cluster is not an active CO2 reduction catalyst because formation of the crucial carboxyl intermediate required very high electrochemical potentials. Instead, our calculations suggest that the reduction process likely occurs on a dethiolated gold site, and adsorbed carboxyl intermediate formation was significantly stabilized at dethiolated gold sites. These findings point to the crucial role of exposed metal sites during electrochemical CO2 reduction at gold nanocluster catalysts.
Synthesis of Ge1−xSnx alloys by ion implantation and pulsed laser melting: Towards a group IV direct bandgap material
Authors: Tran Tuan T. , Pastor David , Gandhi Hemi H. , Smillie Lachlan A. , Akey Austin J. , Aziz Michael J. , Williams J. S.
Published: May 2016

The germanium-tin (Ge1−xSnx) material system is expected to be a direct bandgap group IV semiconductor at a Sn content of 6.5−11 at. %. Such Sn concentrations can be realized by non-equilibrium deposition techniques such as molecular beam epitaxy or chemical vapour deposition. In this report, the combination of ion implantation and pulsed laser melting is demonstrated to be an alternative promising method to produce a highly Sn concentrated alloy with a good crystal quality. The structural properties of the alloys such as soluble Sn concentration, strain distribution, and crystal quality have been characterized by Rutherford backscattering spectrometry, Raman spectroscopy, x ray diffraction, and transmission electron microscopy. It is shown that it is possible to produce a high quality alloy with up to 6.2 at. %Sn. The optical properties and electronic band structure have been studied by spectroscopic ellipsometry. The introduction of substitutional Sn into Ge is shown to either induce a splitting between light and heavy hole subbands or lower the conduction band at the Γ valley. Limitations and possible solutions to introducing higher Sn content into Ge that is sufficient for a direct bandgap transition are also discussed.
Measurement protocol dependent magnetocaloric properties in a Si-doped Mn-rich Mn-Ni-Sn-Si off-stoichiometric Heusler alloy
Authors: Ghosh Arup , Sen Pintu , Mandal Kalyan
Published: May 2016

This work reports the magnetocaloric properties in a Si-doped, Mn-rich Mn46Ni39.5Sn10Si4.5 alloy in the aspects of different measurement protocols across its martensitic and reverse transition. A good agreeable value of the magnetic entropy changes (ΔSM ∼ 20 J/kg K due to a ΔH = 50 kOe) along with large refrigerant capacity (RC ∼ 110 J/kg) has been obtained from the high field M-T measurements, which can be a very handy tool for magnetocaloric study. We have analyzed the field dependent magnetization data during heating and cooling near the structural transition for different field changes and fitted them universally using a Lorentz function. The isothermal measurement by ramping the temperature discontinuously during cooling is found to be one of the most convenient and energy efficient ways to minimize the field induced losses, which helps to achieve a very high RC in similar materials exhibiting first order phase transition. A significant amount of zero field cooled exchange bias field (∼720 Oe at 5 K) and magnetoresistance (∼−25% due to a ΔH = 80 kOe) has also been achieved from this sample.
A semi-discrete Kadomtsev-Petviashvili equation and its coupled integrable system
Authors: Li Chun-Xia , Lafortune Stéphane , Shen Shou-Feng
Published: May 2016

We establish connections between two cascades of integrable systems generated from the continuum limits of the Hirota-Miwa equation and its remarkable nonlinear counterpart under the Miwa transformation, respectively. Among these equations, we are mainly concerned with the semi-discrete bilinear Kadomtsev-Petviashvili (KP) equation which is seldomly studied in literature. We present both of its Casorati and Grammian determinant solutions. Through the Pfaffianization procedure proposed by Hirota and Ohta, we are able to derive the coupled integrable system for the semi-discrete KP equation.
Survival of translocated sharp-tailed grouse: temporal threshold and age effects
Authors: Mathews Steven R. , Coates Peter S. , Delehanty David J.
Published: May 2016

Context The Columbian sharp-tailed grouse (Tympanuchus phasianellus columbianus) is a subspecies of conservation concern in the western United States, currently occupying ≤10% of its historic range. Land and management agencies are employing translocation techniques to restore Columbian sharp-tailed grouse (CSTG) populations. However, establishing self-sustaining populations by translocating grouse often is unsuccessful, owing, in part, to low survivorship of translocated grouse following release. Aims We measured and modelled patterns of CSTG mortality for 150 days following translocation into historic range, to better understand patterns and causes of success or failure in conservation efforts to re-establish grouse populations. Methods We conducted two independent multi-year translocations and evaluated individual and temporal factors associated with CSTG survival up to 150 days following their release. Both translocations were reintroduction attempts in Nevada, USA, to establish viable populations of CSTG into their historic range. Key results We observed a clear temporal threshold in survival probability, with CSTG mortality substantially higher during the first 50 days following release than during the subsequent 100 days. Additionally, translocated yearling grouse exhibited higher overall survival (0.669 ± 0.062) than did adults (0.420 ± 0.052) across the 150-day period and higher survival than adults both before and after the 50-day temporal threshold. Conclusions Translocated CSTG are especially vulnerable to mortality for 50 days following release, whereas translocated yearling grouse are more resistant to mortality than are adult grouse. On the basis of the likelihood of survival, yearling CSTG are better candidates for population restoration through translocation than are adult grouse. Implications Management actions that ameliorate mortality factors for 50 days following translocation and translocations that employ yearling grouse will increase the likelihood of population establishment.
Myosin MyTH4-FERM structures highlight important principles of convergent evolution
Authors: Planelles-Herrero Vicente José , Blanc Florian , Sirigu Serena , Sirkia Helena , Clause Jeffrey , Sourigues Yannick , Johnsrud Daniel O. , Amigues Beatrice , Cecchini Marco , Gilbert Susan P. , Houdusse Anne , Titus Margaret A.
Published: May 2016

Significance

Myosins containing MyTH4-FERM (myosin tail homology 4-band 4.1, ezrin, radixin, moesin, or MF) domains in their tails are found in wide range of phylogenetically divergent organisms. Interestingly, evolutionarily distant MF myosins have similar roles in the extension of actin-filled membrane protrusions, such as filopodia, and microtubule binding, suggesting that their core functions have been highly conserved over evolution. A structural analysis of mammalian and Dd myosin MF domains in combination with comparison of diverse MF myosin sequences illustrate how tuning of existing features can give rise to new structures while preserving the general properties of myosin tails. Thus, tinkering with the MF domain enables it to serve as a multifunctional platform for cooperative recruitment of various partners, allowing common properties to arise through convergent evolution.
Investigations on joining of Nylon 6 plates via novel method of heat assisted friction stir welding to find the optimum process parameters
Authors: Mostafapour A. , Taghizad Asad F.
Published: May 2016

During this research, an attempt was made to join Nylon 6 plates via a novel method of heat assisted friction stir welding by using an external heat source. The results asserted that a sound joint with characteristics similar to the parent material can only be achieved within a certain range of welding parameters. A high quality joint with over 98% of base material strength was obtained with a proper set of parameters. Response surface methodology based on Box–Behnken design was employed to investigate the effects of the different operating conditions on mechanical properties of the joints. It was predicted that tensile strength of joints could reach up to 107.2% of the base material by using the optimised process parameters.
Electromagnetic particle simulation of the effect of toroidicity on linear mode conversion and absorption of lower hybrid waves
Authors: Bao J. , Lin Z. , Kuley A. , Wang Z.X.
Published: May 2016

Effects of toroidicity on linear mode conversion and absorption of lower hybrid (LH) waves in fusion plasmas have been studied using electromagnetic particle simulation. The simulation confirms that the toroidicity induces an upshift of parallel refractive index when LH waves propagate from the tokamak edge toward the core, which affects the radial position for the mode conversion between slow and fast LH waves. Furthermore, moving LH antenna launch position from low field side toward high field side leads to a larger upshift of the parallel refractive index, which helps the slow LH wave penetration into the tokamak core. The broadening of the poloidal spectrum of the wave-packet due to wave diffraction is also verified in the simulation. Both the upshift and broadening effects of the parallel spectrum of the wave-packet modify the parallel phase velocity and thus the linear absorption of LH waves by electron Landau resonance.
Three-dimensional modeling of plasma edge transport and divertor fluxes during application of resonant magnetic perturbations on ITER
Authors: Schmitz O. , Becoulet M. , Cahyna P. , Evans T.E. , Feng Y. , Frerichs H. , Loarte A. , Pitts R.A. , Reiser D. , Fenstermacher M.E. , Harting D. , Kirschner A. , Kukushkin A. , Lunt T. , Saibene G. , Reiter D. , Samm U. , Wiesen S.
Published: May 2016

Results from three-dimensional modeling of plasma edge transport and plasma–wall interactions during application of resonant magnetic perturbation (RMP) fields for control of edge-localized modes in the ITER standard 15 MA Q  =  10 H-mode are presented. The full 3D plasma fluid and kinetic neutral transport code EMC3-EIRENE is used for the modeling. Four characteristic perturbed magnetic topologies are considered and discussed with reference to the axisymmetric case without RMP fields. Two perturbation field amplitudes at full and half of the ITER ELM control coil current capability using the vacuum approximation are compared to a case including a strongly screening plasma response. In addition, a vacuum field case at high q
95  =  4.2 featuring increased magnetic shear has been modeled.

Formation of a three-dimensional plasma boundary is seen for all four perturbed magnetic topologies. The resonant field amplitudes and the effective radial magnetic field at the separatrix define the shape and extension of the 3D plasma boundary. Opening of the magnetic field lines from inside the separatrix establishes scrape-off layer-like channels of direct parallel particle and heat flux towards the divertor yielding a reduction of the main plasma thermal and particle confinement. This impact on confinement is most accentuated at full RMP current and is strongly reduced when screened RMP fields are considered, as well as for the reduced coil current cases.

The divertor fluxes are redirected into a three-dimensional pattern of helical magnetic footprints on the divertor target tiles. At maximum perturbation strength, these fingers stretch out as far as 60 cm across the divertor targets, yielding heat flux spreading and the reduction of peak heat fluxes by 30%. However, at the same time substantial and highly localized heat fluxes reach divertor areas well outside of the axisymmetric heat flux decay profile. Reduced RMP amplitudes due to screening or reduced RMP coil current yield a reduction of the width of the divertor flux spreading to about 20–25 cm and cause increased peak heat fluxes back to values similar to those in the axisymmetric case. The dependencies of these features on the divertor recycling regime and the perpendicular transport assumptions, as well as toroidal averaged effects mimicking rotation of the RMP field, are discussed in the paper.
Sympathomodulatory Effects of Antihypertensive Drug Treatment
Authors: Grassi Guido
Published: May 2016

BACKGROUND

An activation of sympathetic neural influences to the heart and peripheral circulation has been shown to represent a hallmark of the essential hypertensive state, adrenergic neural factors participating together with other variables at the development and progression of the high blood pressure state as well as of the hypertension-related target organ damage. This represents the rationale for employing in hypertension treatment drugs which combine the blood pressure-lowering properties with the modulatory effects on the sympathetic neural function.

METHODS AND RESULTS

Several studies published during the past 40 years have investigated the impact of antihypertensive drugs on the sympathetic target as assessed by indirect and direct approaches. In the present paper, the effects of different monotherapies or combination drug treatment used in hypertension to lower elevated blood pressure values on various adrenergic markers will be examined. This will be followed by a discussion of the (i) hemodynamic and nonhemodynamic consequences of employing antihypertensive drugs with sympathomodulatory or sympathoexcitatory properties and (ii) mechanisms potentially responsible for the adrenergic responses to a given antihypertensive drug. The final part of this review will address the questions still open related to the impact of antihypertensive drug treatment on sympathetic function. Two questions in particular will be examined, i.e., whether antihypertensive drugs with sympathomodulatory properties may be capable to fully restore a “normal” adrenergic drive and how far sympathetic activity should be reduced in hypertensive patients.

CONCLUSION

Future investigations aimed at answering these questions will be needed in order to improve cardiovascular protection in treated hypertensive patients.
A Beta-splitting model for evolutionary trees
Authors: Sainudiin Raazesh , Véber Amandine
Published: May 2016

In this article, we construct a generalization of the Blum–François Beta-splitting model for evolutionary trees, which was itself inspired by Aldous' Beta-splitting model on cladograms. The novelty of our approach allows for asymmetric shares of diversification rates (or diversification ‘potential’) between two sister species in an evolutionarily interpretable manner, as well as the addition of extinction to the model in a natural way. We describe the incremental evolutionary construction of a tree with
n
leaves by splitting or freezing extant lineages through the generating, organizing and deleting processes. We then give the probability of any (binary rooted) tree under this model with no extinction, at several resolutions:
ranked planar trees
giving asymmetric roles to the first and second offspring species of a given species and keeping track of the order of the speciation events occurring during the creation of the tree,
unranked planar trees
,
ranked non-planar trees
and finally (
unranked non-planar
)
trees
. We also describe a continuous-time equivalent of the generating, organizing and deleting processes where tree topology and branch lengths are jointly modelled and provide code in SageMath/Python for these algorithms.
Multiple-stage decisions in a marine central-place forager
Authors: Friedlaender Ari S. , Johnston David W. , Tyson Reny B. , Kaltenberg Amanda , Goldbogen Jeremy A. , Stimpert Alison K. , Curtice Corrie , Hazen Elliott L. , Halpin Patrick N. , Read Andrew J. , Nowacek Douglas P.
Published: May 2016

Air-breathing marine animals face a complex set of physical challenges associated with diving that affect the decisions of how to optimize feeding. Baleen whales (Mysticeti) have evolved bulk-filter feeding mechanisms to efficiently feed on dense prey patches. Baleen whales are central place foragers where oxygen at the surface represents the central place and depth acts as the distance to prey. Although hypothesized that baleen whales will target the densest prey patches anywhere in the water column, how depth and density interact to influence foraging behaviour is poorly understood. We used multi-sensor archival tags and active acoustics to quantify Antarctic humpback whale foraging behaviour relative to prey. Our analyses reveal multi-stage foraging decisions driven by both krill depth and density. During daylight hours when whales did not feed, krill were found in deep high-density patches. As krill migrated vertically into larger and less dense patches near the surface, whales began to forage. During foraging bouts, we found that feeding rates (number of feeding lunges per hour) were greatest when prey was shallowest, and feeding rates decreased with increasing dive depth. This strategy is consistent with previous models of how air-breathing diving animals optimize foraging efficiency. Thus, humpback whales forage mainly when prey is more broadly distributed and shallower, presumably to minimize diving and searching costs and to increase feeding rates overall and thus foraging efficiency. Using direct measurements of feeding behaviour from animal-borne tags and prey availability from echosounders, our study demonstrates a multi-stage foraging process in a central place forager that we suggest acts to optimize overall efficiency by maximizing net energy gain over time. These data reveal a previously unrecognized level of complexity in predator–prey interactions and underscores the need to simultaneously measure prey distribution in marine central place forager studies.
Hamiltonian approach to Ehrenfest expectation values and Gaussian quantum states
Authors: Bonet-Luz Esther , Tronci Cesare
Published: May 2016

The dynamics of quantum expectation values is considered in a geometric setting. First, expectation values of the canonical observables are shown to be equivariant momentum maps for the action of the Heisenberg group on quantum states. Then, the Hamiltonian structure of Ehrenfest’s theorem is shown to be Lie–Poisson for a semidirect-product Lie group, named theEhrenfest group. The underlying Poisson structure produces classical and quantum mechanics as special limit cases. In addition, quantum dynamics is expressed in the frame of the expectation values, in which the latter undergo canonical Hamiltonian motion. In the case of Gaussian states, expectation values dynamics couples to second-order moments, which also enjoy a momentum map structure. Eventually, Gaussian states are shown to possess a Lie–Poisson structure associated with another semidirect-product group, which is called the Jacobi group. This structure produces the energy-conserving variant of a class of Gaussian moment models that have previously appeared in the chemical physics literature.
Blood does not buy goodwill: allowing culling increases poaching of a large carnivore
Authors: Chapron Guillaume , Treves Adrian
Published: May 2016

Quantifying environmental crime and the effectiveness of policy interventions is difficult because perpetrators typically conceal evidence. To prevent illegal uses of natural resources, such as poaching endangered species, governments have advocated granting policy flexibility to local authorities by liberalizing culling or hunting of large carnivores. We present the first quantitative evaluation of the hypothesis that liberalizing culling will reduce poaching and improve population status of an endangered carnivore. We show that allowing wolf (Canis lupus) culling was substantially more likely to increase poaching than reduce it. Replicated, quasi-experimental changes in wolf policies in Wisconsin and Michigan, USA, revealed that a repeated policy signal to allow state culling triggered repeated slowdowns in wolf population growth, irrespective of the policy implementation measured as the number of wolves killed. The most likely explanation for these slowdowns was poaching and alternative explanations found no support. When the government kills a protected species, the perceived value of each individual of that species may decline; so liberalizing wolf culling may have sent a negative message about the value of wolves or acceptability of poaching. Our results suggest that granting management flexibility for endangered species to address illegal behaviour may instead promote such behaviour.
Regionalization of surface lipids in insects
Authors: Wang Yiwen , Yu Zhitao , Zhang Jianzhen , Moussian Bernard
Published: May 2016

Cuticular hydrocarbons (CHCs) play a critical role in the establishment of the waterproof barrier that prevents dehydration and wetting in insects. While rich data are available on CHC composition in different species, we know little about their distribution and organization. Here, we report on our studies of the surface barrier of the fruit flyDrosophila melanogasterapplying a newly developed Eosin Y staining method. The inert Eosin Y penetrates different regions of the adult body at distinct temperatures. By contrast, the larval body takes up the dye rather uniformly and gradually with increasing temperature. Cooling down specimens to 25°C after incubation at higher temperatures restores impermeability. Eosin Y penetration is also sensitive to lipid solvents such as chloroform indicating that permeability depends on CHCs. As inD. melanogasteradult flies, Eosin Y penetration is regionalized inTenebrio molitorlarvae, whereas it is not inLocusta migratorianymphs. Regionalization of the fly surface implies tissue-specific variation of the genetic or biochemical programmes of CHC production and deposition. The Eosin Y-based map of CHC distribution may serve to identify the respective factors that are activated to accommodate ecological needs.
Genetic basis of adult migration timing in anadromous steelhead discovered through multivariate association testing
Authors: Hess Jon E. , Zendt Joseph S. , Matala Amanda R. , Narum Shawn R.
Published: May 2016

Migration traits are presumed to be complex and to involve interaction among multiple genes. We used both univariate analyses and a multivariate random forest (RF) machine learning algorithm to conduct association mapping of 15 239 single nucleotide polymorphisms (SNPs) for adult migration-timing phenotype in steelhead (Oncorhynchus mykiss). Our study focused on a model natural population of steelhead that exhibits two distinct migration-timing life histories with high levels of admixture in nature. Neutral divergence was limited between fish exhibiting summer- and winter-run migration owing to high levels of interbreeding, but a univariate mixed linear model found three SNPs from a major effect gene to be significantly associated with migration timing (p< 0.000005) that explained 46% of trait variation. Alignment to the annotatedSalmo salargenome provided evidence that all three SNPs localize within a 46 kb region overlapping GREB1-like (an oestrogen target gene) on chromosome Ssa03. Additionally, multivariate analyses with RF identified that these three SNPs plus 15 additional SNPs explained up to 60% of trait variation. These candidate SNPs may provide the ability to predict adult migration timing of steelhead to facilitate conservation management of this species, and this study demonstrates the benefit of multivariate analyses for association studies.
Epistasis between antibiotic resistance mutations and genetic background shape the fitness effect of resistance across species ofPseudomonas
Authors: Vogwill T. , Kojadinovic M. , MacLean R. C.
Published: May 2016

Antibiotic resistance often evolves by mutations at conserved sites in essential genes, resulting in parallel molecular evolution between divergent bacterial strains and species. Whether these resistance mutations are having parallel effects on fitness across bacterial taxa, however, is unclear. This is an important point to address, because the fitness effects of resistance mutations play a key role in the spread and maintenance of resistance in pathogen populations. We address this idea by measuring the fitness effect of a collection of rifampicin resistance mutations in the β subunit of RNA polymerase (rpoB) across eight strains that span the diversity of the genusPseudomonas. We find that almost 50% ofrpoBmutations have background-dependent fitness costs, demonstrating that epistatic interactions betweenrpoBand the rest of the genome are common. Moreover, epistasis is typically strong, and it is the dominant genetic determinant of the cost of resistance mutations. To investigate the functional basis of epistasis, and becauserpoBplays a central role in transcription, we measured the effects of commonrpoBmutations on transcriptional efficiency across three strains ofPseudomonas. Transcriptional efficiency correlates strongly to fitness across strains, and epistasis arises because individualrpoBmutations have differential effects on transcriptional efficiency in different genetic backgrounds.
How to colour a flower: on the optical principles of flower coloration
Authors: van der Kooi Casper J. , Elzenga J. Theo M. , Staal Marten , Stavenga Doekele G.
Published: May 2016

The coloration of flowers is due to the wavelength-selective absorption by pigments of light backscattered by structures inside the petals. We investigated the optical properties of flowers using (micro)spectrophotometry and anatomical methods. To assess the contribution of different structures to the overall visual signal of flowers, we used an optical model, where a petal is considered as a stack of differently pigmented and structured layers and we interpreted the visual signals of the model petals with insect vision models. We show that the reflectance depends, in addition to the pigmentation, on the petal's thickness and the inhomogeneity of its interior. We find large between-species differences in floral pigments, pigment concentration and localization, as well as floral interior structure. The fractions of reflected and transmitted light are remarkably similar between the studied species, suggesting common selective pressures of pollinator visual systems. Our optical model highlights that pigment localization crucially determines the efficiency of pigmentary filtering and thereby the chromatic contrast and saturation of the visual signal. The strongest visual signal occurs with deposition of pigments only on the side of viewing. Our systematic approach and optical modelling open new perspectives on the virtues of flower colour.
Differential remodelling of peroxisome function underpins the environmental and metabolic adaptability of diplonemids and kinetoplastids
Authors: Morales Jorge , Hashimoto Muneaki , Williams Tom A. , Hirawake-Mogi Hiroko , Makiuchi Takashi , Tsubouchi Akiko , Kaga Naoko , Taka Hikari , Fujimura Tsutomu , Koike Masato , Mita Toshihiro , Bringaud Frédéric , Concepción Juan L. , Hashimoto Tetsuo , Embley T. Martin , Nara Takeshi
Published: May 2016

The remodelling of organelle function is increasingly appreciated as a central driver of eukaryotic biodiversity and evolution. Kinetoplastids including
Trypanosoma
and
Leishmania
have evolved specialized peroxisomes, called glycosomes. Glycosomes uniquely contain a glycolytic pathway as well as other enzymes, which underpin the physiological flexibility of these major human pathogens. The sister group of kinetoplastids are the diplonemids, which are among the most abundant eukaryotes in marine plankton. Here we demonstrate the compartmentalization of gluconeogenesis, or glycolysis in reverse, in the peroxisomes of the free-living marine diplonemid,
Diplonema papillatum
. Our results suggest that peroxisome modification was already under way in the common ancestor of kinetoplastids and diplonemids, and raise the possibility that the central importance of gluconeogenesis to carbon metabolism in the heterotrophic free-living ancestor may have been an important selective driver. Our data indicate that peroxisome modification is not confined to the kinetoplastid lineage, but has also been a factor in the success of their free-living euglenozoan relatives.
Local adaptation is associated with zinc tolerance inPseudomonasendophytes of the metal-hyperaccumulator plantNoccaea caerulescens
Authors: Fones H. N. , McCurrach H. , Mithani A. , Smith J. A. C. , Preston G. M.
Published: May 2016

Metal-hyperaccumulating plants, which are hypothesized to use metals for defence against pests and pathogens, provide a unique context in which to study plant–pathogen coevolution. Previously, we demonstrated that the high concentrations of zinc found in leaves of the hyperaccumulatorNoccaea caerulescensprovide protection against bacterial pathogens, with a potential trade-off between metal-based and pathogen-induced defences. We speculated that an evolutionary arms race between zinc-based defences inN. caerulescensand zinc tolerance in pathogens might have driven the development of the hyperaccumulation phenotype. Here, we investigate the possibility of local adaptation by bacteria to the zinc-rich environment ofN. caerulescensleaves and show that leaves sampled from the contaminated surroundings of a former mine site harboured endophytes with greater zinc tolerance than those within plants of an artificially created hyperaccumulating population. Experimental manipulation of zinc concentrations in plants of this artificial population influenced the zinc tolerance of recovered endophytes. In laboratory experiments, only endophytic bacteria isolated from plants of the natural population were able to grow to high population densities in anyN. caerulescensplants. These findings suggest that long-term coexistence with zinc-hyperaccumulating plants leads to local adaptation by endophytic bacteria to the environment within their leaves.