bluuebunny/crossref_metadata_2025 huggingface dataset:
Chiro-optical response in helically arranged achiral dielectric nanoparticles
Authors: Singh Haobijam Johnson , Ghosh Ambarish
Published: February 2018

Helically arranged dielectric resonators (amorphous silicon) and their chiro-optical response in single and collective resonance modes.
Simplification and cost reduction of visual corona tests
Authors: Riba Jordi‐Roger , Abomailek Carlos , Casals‐Torrens Pau , Capelli Francesca
Published: February 2018

Visual corona tests are useful to identify the critical corona points of different high‐voltage components. Radio interference voltage and partial discharge measurements also allow detecting corona activity. However, these techniques require expensive screened laboratories, sophisticated instrumentation and usually do not provide the exact location of the discharges. Corona tests are often performed in external laboratories, where customers habitually have to face long waiting times. The tests in such laboratories must be totally planned beforehand, as they are habitually done by external engineers, so little information about the behaviour and possible modifications of the product is acquired by the customer. This study proposes a feasible solution to perform routine corona tests, while greatly reducing the voltage applied, laboratory size and requirements, testing times, and thus test costs. This study also detects the visual corona onset by means of a commercial digital camera, which allows locating the critical corona points, thus greatly decreasing the costs of the corona instrumentation, while maintaining the accuracy and sensitivity of the detection method. The methodology proposed in this study can be applied to many other high‐voltage devices such as conductors, vibration dumpers, corona protections and different types of hardware and fittings for power lines and substations.
Evolution of the cluster optical galaxy luminosity function in the CFHTLS: breaking the degeneracy between mass and redshift
Authors: Sarron F. , Martinet N. , Durret F. , Adami C.
Published: February 2018

Obtaining large samples of galaxy clusters is important for cosmology: cluster counts as a function of redshift and mass can constrain the parameters of our Universe. They are also useful in order to understand the formation and evolution of clusters. We develop an improved version of the Adami & MAzure Cluster FInder (AMACFI), now the Adami, MAzure & Sarron Cluster FInder (AMASCFI), and apply it to the 154 deg2 of the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) to obtain a large catalogue of 1371 cluster candidates with mass M200 > 1014 M⊙ and redshift z ≤ 0.7. We derive the selection function of the algorithm from the Millennium simulation, and cluster masses from a richness–mass scaling relation built from matching our candidates with X-ray detections. We study the evolution of these clusters with mass and redshift by computing the i′-band galaxy luminosity functions (GLFs) for the early-type (ETGs) and late-type galaxies (LTGs). This sample is 90% pure and 70% complete, and therefore our results are representative of a large fraction of the cluster population in these redshift and mass ranges. We find an increase in both the ETG and LTG faint populations with decreasing redshift (with Schechter slopes αETG = −0.65 ± 0.03 and αLTG = −0.95 ± 0.04 at z = 0.6, and αETG = −0.79 ± 0.02 and αLTG = −1.26 ± 0.03 at z = 0.2) and also a decrease in the LTG (but not the ETG) bright end. Our large sample allows us to break the degeneracy between mass and redshift, finding that the redshift evolution is more pronounced in high-mass clusters, but that there is no significant dependence of the faint end on mass for a given redshift. These results show that the cluster red sequence is mainly formed at redshift z > 0.7, and that faint ETGs continue to enrich the red sequence through quenching of brighter LTGs at z ≤ 0.7. The efficiency of this quenching is higher in large-mass clusters, while the accretion rate of faint LTGs is lower as the more massive clusters have already emptied most of their environment at higher redshifts.
Probing the use of spectroscopy to determine the meteoritic analogues of meteors
Authors: Drouard A. , Vernazza P. , Loehle S. , Gattacceca J. , Vaubaillon J. , Zanda B. , Birlan M. , Bouley S. , Colas F. , Eberhart M. , Hermann T. , Jorda L. , Marmo C. , Meindl A. , Oefele R. , Zamkotsian F. , Zander F.
Published: February 2018

Context. Determining the source regions of meteorites is one of the major goals of current research in planetary science. Whereas asteroid observations are currently unable to pinpoint the source regions of most meteorite classes, observations of meteors with camera networks and the subsequent recovery of the meteorite may help make progress on this question. The main caveat of such an approach, however, is that the recovery rate of meteorite falls is low (<20%), implying that the meteoritic analogues of at least 80% of the observed falls remain unknown.

Aims. Spectroscopic observations of incoming bolides may have the potential to mitigate this problem by classifying the incoming meteoritic material.

Methods. To probe the use of spectroscopy to determine the meteoritic analogues of incoming bolides, we collected emission spectra in the visible range (320–880 nm) of five meteorite types (H, L, LL, CM, and eucrite) acquired in atmospheric entry-like conditions in a plasma wind tunnel at the Institute of Space Systems (IRS) at the University of Stuttgart (Germany). A detailed spectral analysis including a systematic line identification and mass ratio determinations (Mg/Fe, Na/Fe) was subsequently performed on all spectra.

Results. It appears that spectroscopy, via a simple line identification, allows us to distinguish the three main meteorite classes (chondrites, achondrites and irons) but it does not have the potential to distinguish for example an H chondrite from a CM chondrite.

Conclusions. The source location within the main belt of the different meteorite classes (H, L, LL, CM, CI, etc.) should continue to be investigated via fireball observation networks. Spectroscopy of incoming bolides only marginally helps precisely classify the incoming material (iron meteorites only). To reach a statistically significant sample of recovered meteorites along with accurate orbits (>100) within a reasonable time frame (10–20 years), the optimal solution may be the spatial extension of existing fireball observation networks.
The nature of the TRAPPIST-1 exoplanets
Authors: Grimm Simon L. , Demory Brice-Olivier , Gillon Michaël , Dorn Caroline , Agol Eric , Burdanov Artem , Delrez Laetitia , Sestovic Marko , Triaud Amaury H. M. J. , Turbet Martin , Bolmont Émeline , Caldas Anthony , de Wit Julien , Jehin Emmanuël , Leconte Jérémy , Raymond Sean N. , Van Grootel Valérie , Burgasser Adam J. , Carey Sean , Fabrycky Daniel , Heng Kevin , Hernandez David M. , Ingalls James G. , Lederer Susan , Selsis Franck , Queloz Didier
Published: February 2018

Context. The TRAPPIST-1 system hosts seven Earth-sized, temperate exoplanets orbiting an ultra-cool dwarf star. As such, it represents a remarkable setting to study the formation and evolution of terrestrial planets that formed in the same protoplanetary disk. While the sizes of the TRAPPIST-1 planets are all known to better than 5% precision, their densities have significant uncertainties (between 28% and 95%) because of poor constraints on the planet’s masses.

Aims. The goal of this paper is to improve our knowledge of the TRAPPIST-1 planetary masses and densities using transit-timing variations (TTVs). The complexity of the TTV inversion problem is known to be particularly acute in multi-planetary systems (convergence issues, degeneracies and size of the parameter space), especially for resonant chain systems such as TRAPPIST-1.

Methods. To overcome these challenges, we have used a novel method that employs a genetic algorithm coupled to a full N-body integrator that we applied to a set of 284 individual transit timings. This approach enables us to efficiently explore the parameter space and to derive reliable masses and densities from TTVs for all seven planets.

Results. Our new masses result in a five- to eight-fold improvement on the planetary density uncertainties, with precisions ranging from 5% to 12%. These updated values provide new insights into the bulk structure of the TRAPPIST-1 planets. We find that TRAPPIST-1 c and e likely have largely rocky interiors, while planets b, d, f, g, and h require envelopes of volatiles in the form of thick atmospheres, oceans, or ice, in most cases with water mass fractions less than 5%.
An integrated inventory model involving discrete setup cost reduction, variable safety factor, selling price dependent demand, and investment
Authors: Dey Bikash Koli , Sarkar Biswajit , Sarkar Mitali , Pareek Sarla
Published: February 2018

This paper develops a sustainable integrated inventory model for maximizing profit with a controllable lead time, discrete setup cost reduction, and consideration of environmental issues. Contrary to the available literature, this paper considers a discrete setup cost for the vendor, thus making the integrated model sustainable. The customer’s demand is assumed to be selling-price dependent to increase the number of sales, and the lead time demand follows a Poisson distribution. The integrated model is used to optimized the total shipment number, volume of shipments, safety factor, investments, selling-price, and probability of moving between the“in-control”to“out-of-control”states. An algorithm is developed to obtain the numerical results. Numerical examples and sensitivity analyses are given to illustrate the model.
Economic-order-type inventory models for non-instantaneous deteriorating items and backlogging
Authors: Ahmad Bashair , Benkherouf Lakdere
Published: February 2018

This paper is concerned with finding the optimal economic order quantity for the basic (EOQ) inventory model with backlogging in the presence of non-instantaneous deterioration. It is shown that the optimal EOQ is a threshold policy. That is, (i) if the time at which deterioration begins in the non-instantaneous deterioration model is greater than or equal to the time at which backlogging begins in the basic (EOQ) model, then the optimal policy is determined by the parameters of the basic (EOQ) model, else (ii) the optimal policy corresponds to the unique critical point of the objective function for the model with non-instantaneous deterioration. An approach for determining this policy is proposed. This approach is simple and easy to implement. Moreover, it does not suffer from the shortcomings of existing approaches in the literature. A numerical example is presented for illustration.
1-(Trimethylsilyl)vinyl MIDA Boronate: A Trifunctional C2 Building Block
Authors: Grygorenko Oleksandr , Ivon Yevhen , Voitenko Zoya
Published: February 2018

1-(Trimethylsilyl)vinyl MIDA boronate — a trifunctional C2 building block — is prepared in only two laboratory steps and 54% overall yield starting from readily available trimethyl(vinyl)silane. The title compound undergoes orthogonal functionalization at either of the groups present in its structure, for example, iodination at the trimethylsilyl moiety, epoxidation at the double bond, and Suzuki–Miyaura coupling at the MIDA boronate.
Homeopathic Dilutions, Hahnemann Principles, and the Solvent Issue: Must We Address Ethanol as a “Homeopathic” or a “Chemical” Issue?
Authors: Chirumbolo Salvatore , Bjørklund Geir
Published: February 2018

Introduction Homeopathic remedies usually contain a significant amount of ethanol as a co-solvent with water, a pharmaceutical formulation that may raise some concern when remedies are tested in vitro or in laboratory animals, due to the assessed toxicity of ethanol on cell cultures and organisms. The amount of alcohol in a homeopathic remedy is adjusted following the different homeopathic pharmacopoeias but it is rarely below 30% v/v, which is a molar mass established to meet both Hahnemann's traditional heritage and the hypothetical role of ethanol in “imprinting” water, through the formation of nanobubbles, with the homeopathic activity of the remedy.

Aims This article aims at discussing the role of ethanol in homeopathic dilutions and how its chemical nature should affect the experimental approach in homeopathy.

Issues Under Debate While the content of ethanol in a homeopathic remedy should be as low as 20% v/v, which is a molar fraction able to catalyze the formation of nanobubbles in a dynamized alcohol–water dilution, this amount raises concern about ethanol toxicology in the experimental research with laboratory animals or in vitro. Several authors diluted 1:100 ethanol 30% v/v from their tested homeopathic dilutions with distilled water to prevent the cytotoxic effect of the alcohol, but in doing so, they probably reduced the ability of ethanol (now 0.3% v/v) to induce the formation of nanobubbles, thus probably affecting the homeopathic property of the same dilution. This may generate concerns about how to manage an experimental setting, to meet both the “chemical” nature of ethanol and its role in “homeopathy,” an issue that is discussed in the article.

Conclusion Any author working with homeopathic dilutions containing a molar fraction of ethanol higher than 20% should take into account the fact that ethanol is cytotoxic and may be a catalyst to the formation of nanobubbles, and so should adjust the experimental approach accordingly.
Die Durchführung der perkutanen gastralen Punktion im Rahmen der PEG-Anlage durch Pflegepersonal – rechtlich und fachlich legitim?
Authors: Karnine Jens
Published: February 2018

Die perkutane endoskopische Gastrostomie ist ein etabliertes endoskopisch-chirurgisches Verfahren zur Anlage von Ernährungskathetern. Die Durchführung im praktischen Alltag erfordert für die Durchführung zwei Ärzte (Endoskopiker und Punkteur) und ist somit sehr personalintensiv. Da dieser Standard der Durchführung nicht immer eingehalten wird oder werden kann, schafft sich die praktische Realität ihre eigenen, kritisch zu hinterfragenden Lösungswege.

Vor dem Hintergrund veränderter Rahmenbedingungen im Gesundheitswesen mit der Notwendigkeit neue Strukturen zu schaffen und Prozesse zu verändern, stellt sich die Frage, ob die Tätigkeit der perkutanen gastralen Punktion im Rahmen der PEG-Anlage nicht auch durch Pflegepersonal durchgeführt werden kann.

Generell wird dies in rechtlichen und fachlichen Aussagen und Vorgaben verneint. Die PEG-Anlage ist als nicht delegierbare ärztliche Aufgabe klassifiziert. Bei genauer Betrachtungen und Untersuchung der in Deutschland gültigen Rechtsquellen, Gesetze, Richtlinien etc. lassen sich allerdings keinerlei Grundlagen schaffende Begründungen diesbezüglich erkennen. Im Rahmen der Betrachtung der praktischen Durchführungstätigkeit erscheint die Aussage der Nichtdelegierbarkeit der Durchführung der perkutanen gastralen Punktion ebenfalls als nicht begründbar und haltlos.

Allerdings muss auch deutlich benannt werden, dass bei einer Übernahme der perkutanen gastralen Punktion durch Pflegepersonal bestimmte strukturelle, prozessorganisatorische und vor allem qualifikatorische Voraussetzungen vorausgesetzt und gegeben sein müssen.
Interface chemical and electronic properties of LaAlO3/SrVO3 heterostructures
Authors: Fouchet Arnaud , Rault Julien E. , Allain Mickaël , Bérini Bruno , Rueff Jean-Pascal , Dumont Yves , Keller Niels
Published: February 2018

We have studied the chemical and electronic properties of LaAlO3/SrVO3 (SVO) ultrathin films by combining hard x-ray photoemission spectroscopy and transport measurements. We compare single SrVO3 (SVO) ultrathin films and SrVO3 buried below a polar LaAlO3 (LAO) thin layer, both epitaxially grown on SrTiO3. While ultrathin films (4 unit cells) of SVO do show insulating behavior over the entire temperature range, the LAO/SVO interface has a resistivity minimum at 250 K. When increasing the SVO layer thickness, the minimum is observed to shift to higher temperatures, but the resistivity always stays smaller than that of comparable SVO single films. Hard x-ray photoemission spectroscopy reveals a surface or interface related V5+ component in the V 2p spectra for SVO films and LAO/SVO heterostructures, respectively, attributed to a strongly oxidized component. This chemical reconstruction is weaker in LAO/SVO heterostructures compared to single SVO films. We show that this dead layer in SVO ultrathin films has to be considered when the film thickness reaches the few unit-cells limit and propose solutions on how to prevent this detrimental effect.
An efficient fluorescent single-particle position tracking system for long-term pulsed measurements of nitrogen-vacancy centers in diamond
Authors: Kim Kiho , Yun Jiwon , Lee Donghyuck , Kim Dohun
Published: February 2018

A simple and convenient design enables real-time three-dimensional position tracking of nitrogen-vacancy (NV) centers in diamond. The system consists entirely of commercially available components (a single-photon counter, a high-speed digital-to-analog converter, a phase-sensitive detector-based feedback device, and a piezo stage), eliminating the need for custom programming or rigorous optimization processes. With a large input range of counters and trackers combined with high sensitivity of single-photon counting, high-speed position tracking (upper bound recovery time of 0.9 s upon 250 nm of step-like positional shift) not only of bright ensembles, but also of low-photon-collection-efficiency single to few NV centers (down to 103 s−1) is possible. The tracking requires position modulation of only 10 nm, which allows simultaneous position tracking and pulsed measurements in the long term. Therefore, this tracking system enables measuring a single-spin magnetic resonance and Rabi oscillations at a very high resolution even without photon collection optimization. The system is widely applicable to various fields related to NV center quantum manipulation research such as NV optical trapping, NV tracking in fluid dynamics, and biological sensing using NV centers inside a biological cell.
GPU-accelerated two dimensional synthetic aperture focusing for photoacoustic microscopy
Authors: Liu Siyu , Feng Xiaohua , Gao Fei , Jin Haoran , Zhang Ruochong , Luo Yunqi , Zheng Yuanjin
Published: February 2018

Acoustic resolution photoacoustic microscopy (AR-PAM) generally suffers from limited depth of focus, which had been extended by synthetic aperture focusing techniques (SAFTs). However, for three dimensional AR-PAM, current one dimensional (1D) SAFT and its improved version like cross-shaped SAFT do not provide isotropic resolution in the lateral direction. The full potential of the SAFT remains to be tapped. To this end, two dimensional (2D) SAFT with fast computing architecture is proposed in this work. Explained by geometric modeling and Fourier acoustics theories, 2D-SAFT provide the narrowest post-focusing capability, thus to achieve best lateral resolution. Compared with previous 1D-SAFT techniques, the proposed 2D-SAFT improved the lateral resolution by at least 1.7 times and the signal-to-noise ratio (SNR) by about 10 dB in both simulation and experiments. Moreover, the improved 2D-SAFT algorithm is accelerated by a graphical processing unit that reduces the long period of reconstruction to only a few seconds. The proposed 2D-SAFT is demonstrated to outperform previous reported 1D SAFT in the aspects of improving the depth of focus, imaging resolution, and SNR with fast computational efficiency. This work facilitates future studies on in vivo deeper and high-resolution photoacoustic microscopy beyond several centimeters.
A sensitive EUV Schwarzschild microscope for plasma studies with sub-micrometer resolution
Authors: Zastrau U. , Rödel C. , Nakatsutsumi M. , Feigl T. , Appel K. , Chen B. , Döppner T. , Fennel T. , Fiedler T. , Fletcher L. B. , Förster E. , Gamboa E. , Gericke D. O. , Göde S. , Grote-Fortmann C. , Hilbert V. , Kazak L. , Laarmann T. , Lee H. J. , Mabey P. , Martinez F. , Meiwes-Broer K.-H. , Pauer H. , Perske M. , Przystawik A. , Roling S. , Skruszewicz S. , Shihab M. , Tiggesbäumker J. , Toleikis S. , Wünsche M. , Zacharias H. , Glenzer S. H. , Gregori G.
Published: February 2018

We present an extreme ultraviolet (EUV) microscope using a Schwarzschild objective which is optimized for single-shot sub-micrometer imaging of laser-plasma targets. The microscope has been designed and constructed for imaging the scattering from an EUV-heated solid-density hydrogen jet. Imaging of a cryogenic hydrogen target was demonstrated using single pulses of the free-electron laser in Hamburg (FLASH) free-electron laser at a wavelength of 13.5 nm. In a single exposure, we observe a hydrogen jet with ice fragments with a spatial resolution in the sub-micrometer range. In situ EUV imaging is expected to enable novel experimental capabilities for warm dense matter studies of micrometer-sized samples in laser-plasma experiments.
Effect of pore geometry on the compressibility of a confined simple fluid
Authors: Dobrzanski Christopher D. , Maximov Max A. , Gor Gennady Y.
Published: February 2018

Fluids confined in nanopores exhibit properties different from the properties of the same fluids in bulk; among these properties is the isothermal compressibility or elastic modulus. The modulus of a fluid in nanopores can be extracted from ultrasonic experiments or calculated from molecular simulations. Using Monte Carlo simulations in the grand canonical ensemble, we calculated the modulus for liquid argon at its normal boiling point (87.3 K) adsorbed in model silica pores of two different morphologies and various sizes. For spherical pores, for all the pore sizes (diameters) exceeding 2 nm, we obtained a logarithmic dependence of fluid modulus on the vapor pressure. Calculation of the modulus at saturation showed that the modulus of the fluid in spherical pores is a linear function of the reciprocal pore size. The calculation of the modulus of the fluid in cylindrical pores appeared too scattered to make quantitative conclusions. We performed additional simulations at higher temperature (119.6 K), at which Monte Carlo insertions and removals become more efficient. The results of the simulations at higher temperature confirmed both regularities for cylindrical pores and showed quantitative difference between the fluid moduli in pores of different geometries. Both of the observed regularities for the modulus stem from the Tait-Murnaghan equation applied to the confined fluid. Our results, along with the development of the effective medium theories for nanoporous media, set the groundwork for analysis of the experimentally measured elastic properties of fluid-saturated nanoporous materials.
Graphene bolometer with thermoelectric readout and capacitive coupling to an antenna
Authors: Skoblin Grigory , Sun Jie , Yurgens August
Published: February 2018

We report on a prototype graphene radiation detector based on the thermoelectric effect. We used a split top gate to create a p-n junction in the graphene, thereby making an effective thermocouple to read out the electronic temperature in the graphene. The electronic temperature is increased due to the AC currents induced in the graphene from the incoming radiation, which is first received by an antenna and then directed to the graphene via the top-gate capacitance. With the exception of the constant DC voltages applied to the gate, the detector does not need any bias and is therefore very simple to use. The measurements showed a clear response to microwaves at 94 GHz with the signal being almost temperature independent in the 4–100 K temperature range. The optical responsivity reached ∼700 V/W.
LiNbO3 waveguides for integrated SPDC spectroscopy
Authors: Solntsev Alexander S. , Kumar Pawan , Pertsch Thomas , Sukhorukov Andrey A. , Setzpfandt Frank
Published: February 2018

Spontaneous parametric down-conversion (SPDC) spectroscopy using photon pairs is a promising avenue towards affordable mid-infrared (MIR) spectroscopy. Here, we experimentally investigate the feasibility of using periodically poled waveguides in lithium niobate for SPDC spectroscopy applications. We find the waveguides suitable to generate wavelength non-degenerate photon pairs with one photon in the MIR spectral range with high fluence. We use this to determine the cutoff wavelengths of the waveguide mode in the MIR by performing only measurements in the near-infrared spectral range.
A radio-frequency ion trap with string electrodes
Authors: Kanai Daisuke , Hasegawa Taro
Published: February 2018

A radio-frequency (rf) ion trap with string electrodes is introduced. In this trap configuration, the rf electrodes are made of narrow metal strings, by which a negligibly small portion of light-induced fluorescence (LIF) is blocked. Then the LIF collection solid angle can be maximized. In the demonstration, barium ions are trapped and laser-cooled in the rf trap with string electrodes successfully, and the crystallization is confirmed by the LIF spectrum.
The quasi-nonassociative exceptional F(4) deformed quantum oscillator
Authors: Aizawa N. , Kuznetsova Z. , Toppan F.
Published: February 2018

We present the deformed (for the presence of Calogero potential terms) one-dimensional quantum oscillator with the exceptional Lie superalgebra F(4) as spectrum-generating superconformal algebra. The Hilbert space is given by a 16-ple of square-integrable functions. The energy levels are 23+n, with n = 0, 1, 2, …. The ground state is 7 times degenerate. The excited states are 8 times degenerate. The (7, 8, 8, 8, …) semi-infinite tower of states is recovered from the (7; 8; 1) supermultiplet of the N=8 worldline supersymmetry. The model is unique, up to similarity transformations, and admits an octonionic-covariant formulation which manifests itself as “quasi-nonassociativity.” This means, in particular, that the Calogero coupling constants are expressed in terms of the octonionic structure constants. The associated F(4) superconformal quantum mechanics is also presented.
Kinetics of laser irradiated nanoparticles cloud
Authors: Mishra S. K. , Upadhyay Kahaly M. , Misra Shikha
Published: February 2018

A comprehensive kinetic model describing the complex kinetics of a laser irradiated nanoparticle ensemble has been developed. The absorbed laser radiation here serves dual purpose, viz., photoenhanced thermionic emission via rise in its temperature and direct photoemission of electrons. On the basis of mean charge theory along with the equations for particle (electron) and energy flux balance over the nanoparticles, the transient processes of charge/temperature evolution over its surface and mass diminution on account of the sublimation (phase change) process have been elucidated. Using this formulation phenomenon of nanoparticle charging, its temperature rise to the sublimation point, mass ablation, and cloud disintegration have been investigated; afterwards, typical timescales of disintegration, sublimation and complete evaporation in reference to a graphite nanoparticle cloud (as an illustrative case) have been parametrically investigated. Based on a numerical analysis, an adequate parameter space describing the nanoparticle operation below the sublimation temperature, in terms of laser intensity, wavelength and nanoparticle material work function, has been identified. The cloud disintegration is found to be sensitive to the nanoparticle charging through photoemission; as a consequence, it illustrates that radiation operating below the photoemission threshold causes disintegration in the phase change state, while above the threshold, it occurs with the onset of surface heating.
Numerical simulations to model laser-driven coil-capacitor targets for generation of kilo-Tesla magnetic fields
Authors: Schillaci F. , De Marco M. , Giuffrida L. , Fujioka S. , Zhang Z. , Korn G. , Margarone D.
Published: February 2018

A coil-capacitor target is modeled using FEM simulations and analytical calculations, which allow to explain the time evolution of such complex target during magnetic field production driven by the flow of an extremely high current generated through the interaction with a high power laser. The numerical model includes a detailed study of the magnetic field produced by the coil-capacitor target, both in the static and transient cases, as well as magnetic force and Joule heating. The model is validated by experimental data reported in literature and can be of interest for several applications. As an example, the combination of two synchronized nanosecond lasers with the purpose of producing a plasma responsible of the proton-boron (p+ + 11B → 8.5 MeV + 3α) fusion reaction, and energizing two multi-turn coils with the main purpose of confining such a plasma could enhance the reaction rate. The preliminary conceptual design of a magnetic mirror configuration to be used for confining protons and boron ions up to a few MeV/u in a region of less than 1 mm2 is briefly reported.
Scaled lattice fermion fields, stability bounds, and regularity
Authors: O’Carroll Michael , Faria da Veiga Paulo A.
Published: February 2018

We consider locally gauge-invariant lattice quantum field theory models with locally scaled Wilson-Fermi fields in d = 1, 2, 3, 4 spacetime dimensions. The use of scaled fermions preserves Osterwalder-Seiler positivity and the spectral content of the models (the decay rates of correlations are unchanged in the infinite lattice). In addition, it also results in less singular, more regular behavior in the continuum limit. Precisely, we treat general fermionic gauge and purely fermionic lattice models in an imaginary-time functional integral formulation. Starting with a hypercubic finite lattice Λ⊂(aZ)d, a ∈ (0, 1], and considering the partition function of non-Abelian and Abelian gauge models (the free fermion case is included) neglecting the pure gauge interactions, we obtain stability bounds uniformly in the lattice spacing a ∈ (0, 1]. These bounds imply, at least in the subsequential sense, the existence of the thermodynamic (Λ ↗ (aZ)d) and the continuum (a ↘ 0) limits. Specializing to the U(1) gauge group, the known non-intersecting loop expansion for the d = 2 partition function is extended to d = 3 and the thermodynamic limit of the free energy is shown to exist with a bound independent of a ∈ (0, 1]. In the case of scaled free Fermi fields (corresponding to a trivial gauge group with only the identity element), spectral representations are obtained for the partition function, free energy, and correlations. The thermodynamic and continuum limits of the free fermion free energy are shown to exist. The thermodynamic limit of n-point correlations also exist with bounds independent of the point locations and a ∈ (0, 1], and with no n! dependence. Also, a time-zero Hilbert-Fock space is constructed, as well as time-zero, spatially pointwise scaled fermion creation operators which are shown to be norm bounded uniformly in a ∈ (0, 1]. The use of our scaled fields since the beginning allows us to extract and isolate the singularities of the free energy when a ↘ 0.
Functional dioecy in Gleditsia amorphoides (Fabaceae)
Authors: Cerino María Carolina , Castro Damián César , Richard Geraldina Alicia , Exner Eliana de Luján , Pensiero José Francisco
Published: February 2018

The genus Gleditsia (Fabaceae) comprises woody shrubs and trees that grow in temperate and subtropical regions around the world. This genus is characterised by sexual polymorphism and functionally unisexual flowers. Gleditsia amorphoides is the southernmost species of the genus, and is widely used as a source of timber and derived products for industrial applications (galactomannans are extracted from its seeds and saponins are derived from its fruits). The species is endemic to the Chaquenean Forest of South America. It is described as morphologically androdioecious, with male and perfect flowers appearing on different plants. In the current study, we characterised floral morphology, experimentally tested the breeding system and analysed flower visitors. Results indicated that G. amorphoides staminate flowers produce viable pollen grains and that perfect flowers have a functional gynoecium and empty anthers, where pollen abortion occurs early in floral development. The species relies on outcrossing, which depends mainly on pollen carried by insect pollinators, to produce seeds and fruits. We conclude that G. amorphoides is functionally dioecious, with staminate and pistillate floral morphs.
Geometrical control of dissipation during the spreading of liquids on soft solids
Authors: Zhao Menghua , Dervaux Julien , Narita Tetsuharu , Lequeux François , Limat Laurent , Roché Matthieu
Published: February 2018

Significance

Soft solids such as gels are routinely used to coat solid surfaces to control wetting and adhesion. While wetting statics on these coatings have received a lot of attention, the dynamics have hardly been studied. Here, we show that energy dissipation during spreading depends not only on the viscoelasticity of the gel but also on the thickness of the coating. We provide both an analytical model and a scaling law that predict the dynamic contact angle—i.e., the signature of dissipation in the droplet–substrate–atmosphere system—as a function of the mechanical properties of the gel and the thickness of the coating. Finally, we show that droplets moving on coatings having thickness gradients drift toward regions of higher dissipation.
PARP-1–dependent recruitment of cold-inducible RNA-binding protein promotes double-strand break repair and genome stability
Authors: Chen Jung-Kuei , Lin Wen-Ling , Chen Zhang , Liu Hung-wen
Published: February 2018

Significance

The repair of DNA double-strand breaks (DSBs) entails complex and highly coordinated machinery, the detailed molecular organization of which remains to be fully understood. In this study, the cold-inducible RNA-binding protein (CIRBP) was identified as an active contributor during DSB repair. On DNA damage, CIRBP was found to temporarily accumulate at DNA damage sites through an interaction with poly(ADP ribose) polymerase-1 (PARP-1)-generated poly(ADP-ribose). CIRBP was also shown to modulate association of the MRN (Mre11, Rad50, and NBS1) complex and ATM kinase with chromatin and to reduce the activation of downstream signaling. The complex interactions among CIRBP, PARP-1, ATM kinase, and MRN provide compelling evidence supporting a role for CIRBP in the regulation of DSB repair and genome stability.
Circadian clock-dependent and -independent posttranscriptional regulation underlies temporal mRNA accumulation in mouse liver
Authors: Wang Jingkui , Symul Laura , Yeung Jake , Gobet Cédric , Sobel Jonathan , Lück Sarah , Westermark Pål O. , Molina Nacho , Naef Felix
Published: February 2018

Significance

Rhythms in gene expression propelled by the circadian clock and environmental signals are ubiquitous across cells and tissues. In particular, in mouse tissues, thousands of transcripts show oscillations with a period of 24 hours. Keys question are how such rhythms propagate and eventually exert functions, but also how these are generated. Here, we developed a mathematical model based on total RNA-seq to classify genes according to the respective contributions of transcriptional and posttranscriptional regulation toward mRNA expression profiles. We found that about one-third of rhythmically accumulating mRNA are under posttranscriptional regulation. Such regulation is only partially dependent on the circadian clock, showing that systemic pathways and feeding patterns contribute important posttranscriptional control of gene expression in liver.
Control of chemoselectivity in asymmetric tandem reactions: Direct synthesis of chiral amines bearing nonadjacent stereocenters
Authors: Li Zhe , Hu Bin , Wu Yongwei , Fei Chao , Deng Li
Published: February 2018

This paper describes the mechanistic insight-guided development of a catalyst system, employing a phenolic proton donor catalyst in addition to a cinchonium-derived phase-transfer catalyst, to control the chemoselectivity of two distinct intermediates, thereby enabling the desired asymmetric tandem conjugate addition–protonation pathway to dominate over a number of side-reaction pathways to provide a synthetic approach for the direct generation of optically active amines bearing two nonadjacent stereocenters.
Assessment of the Legionnaires’ disease outbreak in Flint, Michigan
Authors: Zahran Sammy , McElmurry Shawn P. , Kilgore Paul E. , Mushinski David , Press Jack , Love Nancy G. , Sadler Richard C. , Swanson Michele S.
Published: February 2018

The 2014–2015 Legionnaires’ disease (LD) outbreak in Genesee County, MI, and the outbreak resolution in 2016 coincided with changes in the source of drinking water to Flint’s municipal water system. Following the switch in water supply from Detroit to Flint River water, the odds of a Flint resident presenting with LD increased 6.3-fold (95% CI: 2.5, 14.0). This risk subsided following boil water advisories, likely due to residents avoiding water, and returned to historically normal levels with the switch back in water supply. During the crisis, as the concentration of free chlorine in water delivered to Flint residents decreased, their risk of acquiring LD increased. When the average weekly chlorine level in a census tract was <0.5 mg/L or <0.2 mg/L, the odds of an LD case presenting from a Flint neighborhood increased by a factor of 2.9 (95% CI: 1.4, 6.3) or 3.9 (95% CI: 1.8, 8.7), respectively. During the switch, the risk of a Flint neighborhood having a case of LD increased by 80% per 1 mg/L decrease in free chlorine, as calculated from the extensive variation in chlorine observed. In communities adjacent to Flint, the probability of LD occurring increased with the flow of commuters into Flint. Together, the results support the hypothesis that a system-wide proliferation of legionellae was responsible for the LD outbreak in Genesee County, MI.
Utilizing Bloom's Taxonomy to Design a Substance use Disorders Course for Health Professions Students
Authors: Muzyk Andrew J. , Tew Chris , Thomas-Fannin Allie , Dayal Sanjai , Maeda Reina , Schramm-Sapyta Nicole , Andolsek Kathryn , Holmer Shelley
Published: February 2018

Background: Substance use disorders (SUDs) are a public health problem affecting millions of Americans. Despite their prevalence, there are few health care resources allocated for SUDs treatment. Relatively few health care professionals are exposed to SUDs education in their respective programs, which may be one reason for this resource insufficiency. In hopes of rectifying this gap, the authors developed a SUDs course for health professions students combining classroom learning with practical application to patient care. Methods: The authors used Bloom's taxonomy of cognitive, affective, and psychomotor learning domains as an educational framework to create numerous opportunities for students to deepen their knowledge, assess their attitudes, and develop their motivational interviewing skills. The primary outcome of the study was a comparison of students’ scores on the Substance Abuse Attitude Scale (SAAS) pre- and post-course completion. Secondary outcome was to compare students’ self-assessment scores of their patient counseling with residents’ assessments of them on the Liverpool Communication Skills Assessment Scale (LCSAS). Results: One hundred twelve students participated in the authors’ SUDs course over a 9-month period. Ninety-five students completed both the pre- and post-course SAAS surveys. The total SAAS survey score and individual domain scores for nonmoralizing, treatment optimism, and treatment intervention demonstrated significant improvement post-course. Eighty-nine students completed a motivational interview with a patient. Eighty students had a LCSAS self-assessment paired with a residents’ assessment. Mean scores for individual items on the LCSAS for both groups’ assessment were approximately 3.5, indicating that students’ communication was assessed as “acceptable” to “good.” Conclusions: This study demonstrates that Bloom's taxonomy was a useful educational framework to ensure a systematic development of the authors’ SUDs course. Through participation in our course, students touched each of the 3 domains in Bloom's taxonomy. The authors believe their course design may serve as a framework for future SUDs courses.
The longitudinal relationship between generalized self‐efficacy and physical activity in school‐aged children
Authors: Li Yao‐Chuen , Joshi Divya , King‐Dowling Sara , Hay John , Faught Brent E. , Cairney John
Published: February 2018

Our understanding of the longitudinal relationship between generalized self‐efficacy (GSE) and physical activity in children and youth is limited. The purpose of this study was to investigate the effect of GSE towards physical activity on sedentary behaviours and physical activity in school‐aged children over time. A total of 2278 nine‐year‐old children (1120 girls and 1158 boys) were recruited at baseline and followed for seven waves of data collection from 2005 to 2008. All children completed questionnaires at each wave assessing their GSE (adequacy, predilection, and enjoyment), sedentary behaviours, free play, and organized activity. Mixed‐effects models were used to estimate changes in physical activity and GSE within individuals over time, controlling for gender and motor ability. The results showed that participation in free play significantly increased over time, whereas organized activity significantly decreased over the same period. Children with high perceived adequacy and predilection had higher free play and organized activity participation relative to other children over time. However, the effect of perceived adequacy diminished over time, while the gaps between groups with different levels of predilection widened over time. While sedentary behaviours were lower over time in children with high predilection, these behaviours were consistently higher in children with high enjoyment. The differences in sedentary behaviours between groups increased over time for both predilection and enjoyment. This study highlights the importance of different components of GSE on physical activity participation. In addition, interventions targeting the enhancement of predilection may facilitate physical activity and reduce sedentary behaviours.
GCevobase: an evolution-based database for GC content in eukaryotic genomes
Authors: Wang Dapeng
Published: February 2018

How to comprehend the underlying mechanism behind the origin and evolution of genome composition such as GC content has been regarded as a long-standing crucial question, highlighting its biological significance and functional relevance. To varying extents, several systematically identified patterns of GC content variations are shown to be linked to a set of genomic features in the events of replication, transcription, translation and recombination, with strong contrasts between diverse phylogenetic or taxonomical groups. In this situation, we develop a repository—GCevobase—which houses compositional and size related data presented in various forms from 1118 genomes including 5 major clades of eukaryotic species such as vertebrates, invertebrates, plants, fungi and protists. It analyzes the cautiously selected sequences with clearly-defined bases and structures them under the taxonomical classification system (kingdom, phylum, class, order and family) at the genome and gene scales. It uses the diversified and intelligible graphs to show the statistical measurements of GC content in the sequence, at the three codon positions and at 4-fold degenerate sites and CDS length and their genome-wide correlations and display the evolutionary pathways of GC content by taking into account between-species orthologs and within-species paralogs for each annotated gene. In addition, a lot of internal and external links have been created, making it an effective communication between the data from individual genomes and the raw data are downloadable.

Availability and implementation

https://github.com/NextGenBioinformatics/GCevobase

Supplementary information

Supplementary data are available at Bioinformatics online.
Accelerometer Physical Activity is Associated with Greater Gray Matter Volumes in Older Adults Without Dementia or Mild Cognitive Impairment
Authors: Halloway Shannon , Arfanakis Konstantinos , Wilbur JoEllen , Schoeny Michael E , Pressler Susan J
Published: February 2018

Objectives

Physical activity (PA) is a modifiable health behavior that can protect against age-related gray matter atrophy and cognitive dysfunction. Current studies of PA and gray matter failed to utilize device measures of PA and do not focus on adults >80 years. Thus, the purpose of this secondary analysis was to examine cross-sectional associations between accelerometer lifestyle PA and (a) gray matter volumes and (b) cognitive function, controlling for demographics, and health status.

Method

Participants were 262 older adults without dementia or mild cognitive impairment from Rush Memory and Aging Project, an epidemiological cohort study. Participants wore an accelerometer to assess total daily lifestyle PA, and completed anatomical magnetic resonance imaging to assess gray matter volumes and a neurocognitive test battery to assess cognitive function.

Results

Multivariate linear regression indicated that higher levels of total daily lifestyle PA was significantly related to larger gray matter volumes, F(2, 215) = 3.61, p = .027, including subcortical gray matter (β = 0.17, p = .007) and total gray matter (β = 0.11, p = .049), with no significant associations between lifestyle PA and cognitive function.

Discussion

These findings may inform future lifestyle PA interventions in order to attenuate age-related gray matter atrophy.
Where the Solar system meets the solar neighbourhood: patterns in the distribution of radiants of observed hyperbolic minor bodies
Authors: de la Fuente Marcos Carlos , de la Fuente Marcos Raúl , Aarseth Sverre J
Published: February 2018

Observed hyperbolic minor bodies might have an interstellar origin, but they can be natives of the Solar system as well. Fly-bys with the known planets or the Sun may result in the hyperbolic ejection of an originally bound minor body; in addition, members of the Oort cloud could be forced to follow inbound hyperbolic paths as a result of secular perturbations induced by the Galactic disc or, less frequently, due to impulsive interactions with passing stars. These four processes must leave distinctive signatures in the distribution of radiants of observed hyperbolic objects, both in terms of coordinates and velocity. Here, we perform a systematic numerical exploration of the past orbital evolution of known hyperbolic minor bodies using a full N-body approach and statistical analyses to study their radiants. Our results confirm the theoretical expectations that strong anisotropies are present in the data. We also identify a statistically significant overdensity of high-speed radiants towards the constellation of Gemini that could be due to the closest and most recent known fly-by of a star to the Solar system, that of the so-called Scholz's star. In addition to and besides 1I/2017 U1 (‘Oumuamua), we single out eight candidate interstellar comets based on their radiants’ velocities.