bluuebunny/crossref_metadata_2025 huggingface dataset:
Antimycobacterial Activity of Alkaloids and Extracts from Tabernaemontana alba and T. arborea
Authors: Guzmán-Gutiérrez Silvia Laura , Silva-Miranda Mayra , Krengel Felix , Huerta-Salazar Elizabeth , León-Santiago Mayra , Díaz-Cantón Jessica Karina , Espitia Pinzón Clara , Reyes-Chilpa Ricardo
Published: May 2020

Tuberculosis is the main cause of death from a single infectious agent. Globally, according to the World Health Organization, in 2018, there were an estimated 1.2 million tuberculosis deaths. Moreover, there is a continuous appearance of drug-resistant strains. Thus, development of new antituberculosis medicines should receive high priority. Plant-derived natural products are promising candidates for this purpose. We therefore screened alkaloid extracts obtained from the root and stem barks of the Mexican Apocynaceae species Tabernaemontana alba and Tabernaemontana arborea, as well as the pure alkaloids ibogaine, voacangine, and voacamine, tested for activity against Mycobacterium tuberculosis H37Rv and cytotoxicity to mammalian Vero cells using the resazurin microtiter and the MTT assays, respectively. The extracts were analyzed by GC-MS and HPLC-UV. T. arborea root bark alkaloid extract showed the highest activity against M. tuberculosis (MIC100 = 7.8 µg/mL) of the four extracts tested. HPLC suggested that voacangine and voacamine were the major components. The latter was isolated by column chromatography, and its chemical structure was elucidated by 1H and 13C NMR, and MS. Unambiguous assignation was performed by HSQC, HMBC, and NOESY experiments. Voacamine is a dimeric bis-indole-type alkaloid and is 15 times more potent than the monomeric ibogan-type alkaloids ibogaine and voacangine (MIC100 = 15.6, 250.0, and 250.0 µg/mL, respectively). However, all of these compounds showed cytotoxicity to Vero cells, with a poor selectivity index of 1.00, 0.16, and 1.42, respectively. This is the first report of voacamine activity against M. tuberculosis.
Optic Atrophy and Generalized Chorea in a Patient Harboring an OPA10/RTN4IP1 Pathogenic Variant
Authors: Giacomini Thea , Gamucci Alessandra , Pisciotta Livia , Nesti Claudia , Fiorillo Chiara , Doccini Stefano , Morana Giovanni , Nobili Lino , Santorelli Filippo M. , Mancardi Maria Margherita , De Grandis Elisa
Published: May 2020

RTN4IP1 pathogenic variants (OPA10 syndrome) have been described in patients with early-onset recessive optic neuropathy and recently associated with a broader clinical spectrum, from isolated optic neuropathy to severe encephalopathies with epilepsy. Here we present a case of a patient with a complex clinical picture characterized by bilateral optic nerve atrophy, horizontal nystagmus, myopia, mild intellectual disability, generalized chorea, isolated small subependymal heterotopia, and asynchronous self-resolving midbrain MRI (magnetic resonance imaging) lesions. By using massive gene sequencing, we identified in this patient the c.308G > A (p.Arg103His) homozygous pathogenic variant in the RTN4IP1 gene. Complex movement disorders and relapsing-remitting neuroradiological lesions have not been previously reported in this condition. Our case expands the clinical spectrum of OPA10 syndrome and opens new opportunities for the molecular diagnosis.
The linchpin of Eurasia: Kazakhstan and the Eurasian economic union between Russia’s defensive regionalism and China’s new Silk Roads
Authors: Pieper Moritz
Published: May 2020

This paper analyses the extent to which Kazakhstan’s agency in its interaction with China’s ‘Belt and Road’ initiative is shaped not only by Russia and China’s outward projection, but also de-centring practices at the regional and sub-national level. The Kazakhstani government has embraced China’s Silk Road economic belt (SREB—the land-based ‘belt’ of the BRI) and has aligned its ‘Nurly Zhol’ domestic stimulus programme with the SREB. At the same time, Kazakhstan’s membership in the Eurasian Economic Union increases Russian leverage over Kazakhstani trade and tariff policies. The advent of the BRI thus exacerbates, but has not caused, a partially competing logic behind Russia’s defensive regionalism and Kazakhstan’s professed multi-vector foreign policy. Contrasting the latter with Russian and Chinese geopolitical constraints imposed on the sociopolitical fabric of Kazakhstan, the paper examines how Kazakhstan is a microcosm for the dynamics of a new Eurasian order in the making.
Rapid data-driven model reduction of nonlinear dynamical systems including chemical reaction networks using ℓ1-regularization
Authors: Yang Q. , Sing-Long C. A. , Reed E. J.
Published: May 2020

Large-scale nonlinear dynamical systems, such as models of atmospheric hydrodynamics, chemical reaction networks, and electronic circuits, often involve thousands or more interacting components. In order to identify key components in the complex dynamical system as well as to accelerate simulations, model reduction is often desirable. In this work, we develop a new data-driven method utilizing ℓ1-regularization for model reduction of nonlinear dynamical systems, which involves minimal parameterization and has polynomial-time complexity, allowing it to easily handle large-scale systems with as many as thousands of components in a matter of minutes. A primary objective of our model reduction method is interpretability, that is to identify key components of the dynamical system that contribute to behaviors of interest, rather than just finding an efficient projection of the dynamical system onto lower dimensions. Our method produces a family of reduced models that exhibit a trade-off between model complexity and estimation error. We find empirically that our method chooses reduced models with good extrapolation properties, an important consideration in practical applications. The reduction and extrapolation performance of our method are illustrated by applications to the Lorenz model and chemical reaction rate equations, where performance is found to be competitive with or better than state-of-the-art approaches.
On the highly swirling flow through a confined bluff-body
Authors: Brito Lopes A. V. , Emekwuru N. , Bonello B. , Abtahizadeh E.
Published: May 2020

We address highly swirling, confined-bluff-body-flow evolving through a burner; particularly, contributions of the swirling motion to a central-recirculation-zone (CRZ) downstream the injector. Previous studies suggest that flame stability reduces in combustors lacking this zone; careful consideration of the CRZ is thus desirable. We use Reynolds-Averaged-Navier–Stokes (RANS) and Large-Eddy-Simulation (LES) to simulate the flow, and the influence of the swirl device was included in defining the inflow conditions for LES simulations. We use mean velocity profiles and turbulence statistics to test results. There is qualitative agreement between computed and reported experimental data, and we document quantitative differences obtained with the RANS models. LES velocity field results are mostly within 3% of the experimental data, better than the latest reported LES data, reinforcing the suitability of our approach. We took advantage of the quality of the LES mesh, which solves 95.6% of the resolved-turbulence-energy, to present the vorticity structures showing the precessing vortex motion on the CRZ boundaries. Anisotropic states of the Reynolds-stress were characterized with the aid of an anisotropy invariant map, a novelty for this type of burner; the turbulence states considerably vary inside the burner, behaving isotropically in the center of the CRZ, whereas axisymmetric turbulence is predominant in the other areas of the CRZ. The results reinforce the importance of applying appropriate turbulence models and inflow conditions for simulations involving confined-bluff-body-flows in order to capture the main flow fields and structures in the CRZ.
Glassy dielectric anomaly and negative magneto-capacitance effect in electron-doped Ca1−xSrxMn0.85Sb0.15O3
Authors: Taniguchi Haruka , Takahashi Hidenori , Terui Akihiro , Sadamitsu Kensuke , Sato Yuka , Ito Michihiro , Nonaka Katsuhiko , Kobayashi Satoru , Matsukawa Michiaki , Suryanarayanan Ramanathan , Sasaki Nae , Yamaguchi Shunpei , Watanabe Takao
Published: May 2020

Manganites exhibit various types of electronic phenomena, and these electronic characteristics can be controlled by carrier doping. Herein, we report the dielectric and magnetic properties of electron-doped manganite Ca1−xSrxMn0.85Sb0.15O3 (x=0, 0.1, 0.2, and 0.3). The temperature dependence of the real part of the dielectric constant exhibits a broad and large peak just below the kink temperature of magnetization and a sharp decrease at lower temperatures, accompanied by an anomaly of the imaginary part. Furthermore, isovalent Sr substitution enhances the temperature of the dielectric peak by more than 50 K. Interestingly, the dielectric peak exhibits a negative magnetic-field effect. For all measured samples, the low-temperature variation of the dielectric constant can be qualitatively explained based on the Maxwell–Wagner (MW) model that describes a system composed of grain boundaries and semiconducting grains. However, the observed peak and its negative magneto-capacitance effect at high temperatures cannot be reproduced by a combination of the MW model and magnetoresistance effect. The dielectric peak strongly indicates polaronic relaxation in the present system. These results suggest that polarons form clusters with a dipole ordering and magneto-electric coupling, which might be consistently understood by the charge-ordering scenario.
The existence of strange nonchaotic attractors in the quasiperiodically forced Ricker family
Authors: Li Gaolei , Yue Yuan , Li Denghui , Xie Jianhua , Grebogi Celso
Published: May 2020

In this paper, the Ricker family (a population model) with quasiperiodic excitation is considered. The existence of strange nonchaotic attractors (SNAs) is analyzed in a co-dimension-2 parameter space by both theoretical and numerical methods. We prove that SNAs exist in a positive measure parameter set. The SNAs are nowhere differentiable (i.e., strange). We use numerical methods to identify the existence of SNAs in a larger parameter set. The nonchaotic property of SNAs is verified by evaluating the Lyapunov exponents, while the strange property is characterized by phase sensitivity and rational approximations. We also find that there is a transition region in a parameter plane in which SNAs alternate with chaotic attractors.
Influences of Hall current and radiation on MHD micropolar non-Newtonian hybrid nanofluid flow between two surfaces
Authors: Islam Saeed , Khan Arshad , Deebani Wejdan , Bonyah Ebenezer , Alreshidi Nasser Aedh , Shah Zahir
Published: May 2020

In this article, the magnetohydrodynamic flow and heat transmission of a micropolar hybrid nanofluid between two surfaces inside a rotating system are examined. The Hall current and thermal radiations are also considered for the flow system. In this article, a base fluid is taken as water, while graphene oxide (GO) and copper (Cu) are applied as hybrid nanoparticles. The flow is assumed to be in a steady state. The governing partial differential equations along with boundary conditions for the modeled problem are transformed into a system of non-linear ordinary differential equations using similarity transformations. The set of resultant ordinary differential equations is solved by using an optimal approach. The main focus of this study is to examine the magnetohydrodynamic heat transmission and hybrid nanofluid flow in a rotating system between two parallel plates by taking into account the thermal radiations and Hall current impacts. Various physical parameters are discussed in detail graphically in this article. The main outcome of this study indicates that the augmented values of the magnetic parameter increase the velocity profile and decrease the rotational velocity profile.
Electromechanical properties of soft dissipative dielectric elastomer actuators influenced by electrode thickness and conductivity
Authors: Zhang Junshi , Liu Lei , Chen Hualing
Published: May 2020

Viscoelasticity and charge leakage are two typical dissipations of a dielectric elastomer (DE). During applied voltage loading, the electrodes tune the electromechanical deformation of DE, which results from the non-ideal insulator attribute of the DE. In this article, the influence of the electrodes is considered to establish a thorough electrodes-coupled dissipative model of DE. The effect that electrode thickness and conductivity has on the static and dynamic properties of the DE is investigated, including the electromechanical deformation of DE membrane and the voltage loaded across the thickness direction. It is found that the electromechanical deformation and voltage across the DE membrane gradually reduce with increasing electrode thickness and decreasing electrode conductivity. Resonance characteristics of the DE for varying electrode thickness and conductivity are also analyzed. The results demonstrate that electrodes with minimal thickness and high conductivity mitigate the resonant frequency and enhance the vibration intensity of the DE system.
Axisymmetric mixed convective propulsion of a non-Newtonian fluid through a ciliated tubule
Authors: Farooq A. A. , Shah Zahir , Shutaywi Meshal , Bonyah Ebenezer , Roy Prosun
Published: May 2020

Thousands of chemical reactions occur in the human body when certain biological fluids, such as blood, semen, mucus, and synovial joint materials, move in various organs. These reactions play a vital role in regulating the life sustaining metabolic processes in the body. Analysis of thermal effects on these chemical reactions is relatively a new area in modern clinical medications. The present study investigates a simulation of the combined response due to heat and mass transport mechanisms taking place in the human body during the flow of physiological fluids. In particular, we focus our attention on the human male reproductive system, wherein the semen transports through the ductus efferentes due to metachronal waves of cilia. The constitutive relations of the robust Jeffrey viscoelastic fluid are used to model the human semen. The mathematical model of the present problem constitutes the axisymmetric flow of a Jeffrey fluid inside a vertical tubule under the influence of mixed convective heat and mass transfers. The inner side of the tubule is covered with ciliated structures. The influence of thermal behaviors of various metabolic processes in the human body due to an external heat source or sink is also taken into account. The mathematical formulation consists of using the approach of lubrication theory approximation; the nonlinear momentum, energy, and concentration equations are simplified to get analytical solutions. Explicit expressions for temperature, concentration, velocity, pressure gradient, and volume flow rate of the proposed bodily fluid (i.e., human semen) are formulated. The expression for the volume flow rate is used to estimate the volume flux of the semen under the influence of various parameters. A comparison between the theoretical and experimentally obtained values of the flow rate of the human semen is also made. It is noted that our calculated values are very close to the estimated values. Industrial applications of the present results are obvious in the fabrication of artificial cilia pumping systems for microfluidic flow systems.
Visualization of compensating currents in type-II/1 superconductor via high field cooling
Authors: Valsecchi Jacopo , White Jonathan S. , Bartkowiak Marek , Treimer Wolfgang , Kim Youngju , Lee Seung Wook , Gokhfeld Denis M. , Harti Ralph P. , Morgano Manuel , Strobl Markus , Grünzweig Christian
Published: May 2020

The morphology of vortex lattice domains in bulk type-II/1 superconductors is of central interest for many areas such as fundamental condensed matter physics, engineering science, and the optimization of materials for high transport current superconductivity applications. Here, we present a comprehensive experimental study of a single crystal niobium in the intermediate mixed state and Shubnikov phase with two complementary neutron techniques: high resolution polarized neutron imaging and small-angle neutron scattering. In this way, we were able to identify and visualize the occurrence of compensating currents, the flux line closure, and the freezing of the vortex spacing during the process of field cooling and high field cooling. With the combination of complementary neutron techniques, it was possible to add insights into the quest for the understanding of the flux pinning and nucleation of vortices in type-II/1 superconductors during the process of field cooling and high field cooling.
e
T
1.0: An open source electronic structure program with emphasis on coupled cluster and multilevel methods
Authors: Folkestad Sarai D. , Kjønstad Eirik F. , Myhre Rolf H. , Andersen Josefine H. , Balbi Alice , Coriani Sonia , Giovannini Tommaso , Goletto Linda , Haugland Tor S. , Hutcheson Anders , Høyvik Ida-Marie , Moitra Torsha , Paul Alexander C. , Scavino Marco , Skeidsvoll Andreas S. , Tveten Åsmund H. , Koch Henrik
Published: May 2020

The eT program is an open source electronic structure package with emphasis on coupled cluster and multilevel methods. It includes efficient spin adapted implementations of ground and excited singlet states, as well as equation of motion oscillator strengths, for CCS, CC2, CCSD, and CC3. Furthermore, eT provides unique capabilities such as multilevel Hartree–Fock and multilevel CC2, real-time propagation for CCS and CCSD, and efficient CC3 oscillator strengths. With a coupled cluster code based on an efficient Cholesky decomposition algorithm for the electronic repulsion integrals, eT has similar advantages as codes using density fitting, but with strict error control. Here, we present the main features of the program and demonstrate its performance through example calculations. Because of its availability, performance, and unique capabilities, we expect eT to become a valuable resource to the electronic structure community.
A model of micro lubrication between two walls with an arbitrary temperature difference based on kinetic theory
Authors: Doi Toshiyuki
Published: May 2020

Micro lubrication of a gas between two walls with an arbitrary temperature difference is studied on the basis of the Bhatnagar–Gross–Krook–Welander model of the Boltzmann equation. Applying the slowly varying approximation, the kinetic equation is studied analytically when the Knudsen number based on the gap size is large. The leading order approximation, which ought to be the solution of the nonlinear heat transfer problem, is replaced by its free molecular solution. Due to this crude approximation, a macroscopic lubrication model of Reynolds-type equation is derived in a closed form. For an assessment of the model, a direct numerical analysis of the kinetic equation is also conducted. The lift calculated using our model approximates that of the direct numerical analysis within the error of 4% uniformly in the range of the temperature ratio between 0.75 and 2 and the Knudsen number Kn between 0.1 and 10. A heating of the moving wall reduces the lift acting on the other wall when Kn is sufficiently large, whereas it is enhanced when Kn is sufficiently small.
Increased electrical conduction with high hole mobility in anti-ThCr2Si2-type La2O2Bi via oxygen intercalation adjacent to Bi square net
Authors: Matsumoto Kota , Kawasoko Hideyuki , Kasai Hidetaka , Nishibori Eiji , Fukumura Tomoteru
Published: May 2020

Anti-ThCr2Si2-type RE2O2Bi (RE = rare earth) with a Bi square net is known to show an insulator–metal transition by substituting RE. In this study, La2O2Bi polycrystals with different oxygen nonstoichiometry were synthesized. As the amount of oxygen in La2O2Bi increased, the c-axis length was expanded due to the generation of an additional 4e site for excess oxygen, while the a-axis length remained almost constant, indicating the separation of Bi square nets by oxygen intercalation. Concomitantly, transformation of insulating La2O2Bi into metallic La2O2Bi occurred with the change in carrier polarity from the n- to p-type. Despite its polycrystalline form, La2O2Bi with the largest amount of oxygen showed a rather high hole mobility of 85 cm2 V−1 s−1 among other layered oxypnictides and oxychalcogenides.
p-type conduction mechanism in continuously varied non-stoichimetric SnOx thin films deposited by reactive sputtering with the impedance control
Authors: Jia Junjun , Sugane Takumi , Nakamura Shin-ichi , Shigesato Yuzo
Published: May 2020

We successfully fabricated a series of SnOx films varying from SnO2 to SnO using reactive sputtering. By precisely tailoring the transition region in reactive sputtering, a continuous structural evolution from SnO2 to SnO was observed with SnO2 films showing a typical columnar structure and SnO films having a dense film structure with larger crystallites. X-ray diffraction measurement confirmed that the fabricated SnO films coexist with the minor SnO2 and Sn3O4 phases. SnO films exhibit an unintentional p-type conductivity, and the interstitial oxygen possibly acts as the acceptor. The maximum hole mobility is 3.38cm2/Vs at a hole concentration of 1.12×1018cm−3. We propose a p-type conduction mechanism for those SnOx films with the major SnO phase coexisting with the minor SnO2 and Sn3O4 phases, in which the possible optimum for the hole transport can be achieved by tailoring the balance between the amounts of the SnO2/Sn3O4 phases and interstitial oxygen.
The magnetic, electronic, and light-induced topological properties in two-dimensional hexagonal FeX2 (X = Cl, Br, I) monolayers
Authors: Kong Xiangru , Li Linyang , Liang Liangbo , Peeters François M. , Liu Xiong-Jun
Published: May 2020

Using Floquet–Bloch theory, we propose to realize chiral topological phases in two-dimensional (2D) hexagonal FeX2 (X = Cl, Br, I) monolayers under irradiation of circularly polarized light. Such 2D FeX2 monolayers are predicted to be dynamically stable and exhibit both ferromagnetic and semiconducting properties. To capture the full topological physics of the magnetic semiconductor under periodic driving, we adopt ab initio Wannier-based tight-binding methods for the Floquet–Bloch bands, with the light-induced bandgap closings and openings being obtained as the light field strength increases. The calculations of slabs with open boundaries show the existence of chiral edge states. Interestingly, the topological transitions with branches of chiral edge states changing from zero to one and from one to two by tuning the light amplitude are obtained, showing that the topological Floquet phase of high Chern number can be induced in the present Floquet–Bloch systems.
Bipolar spin Hall nano-oscillators
Authors: Hache T. , Li Y. , Weinhold T. , Scheumann B. , Gonçalves F. J. T. , Hellwig O. , Fassbender J. , Schultheiss H.
Published: May 2020

We demonstrate a spin Hall nano-oscillator (SHNO) that allows for efficient tuning of magnetic auto-oscillations over an extended range of gigahertz frequencies, using bipolar direct currents at constant magnetic fields. This is achieved by stacking two distinct ferromagnetic layers with a platinum interlayer. In this device, the orientation of the spin polarized electrons accumulated at the top and bottom interfaces of the platinum layer is switched upon changing the polarity of the direct current. As a result, the effective anti-damping required to drive large amplitude auto-oscillations can appear either at the top or bottom magnetic layer. Tuning of the auto-oscillation frequencies by several gigahertz can be achieved by combining two materials with sufficiently different saturation magnetizations. Here, we show that the combination of NiFe and CoFeB can result in 3 GHz shifts in the auto-oscillation frequencies. Bipolar SHNOs as such may bring enhanced synchronization capabilities to neuromorphic computing applications.
Characteristics and temperature-field-thickness evolutions of magnetic domain structures in van der Waals magnet Fe3GeTe2 nanolayers
Authors: Wang Hong , Wang Cuixiang , Li Zi-An , Tian Huanfang , Shi Youguo , Yang Huaixin , Li Jianqi
Published: May 2020

In two-dimensional van der Waals magnets, the presence of magnetic orders, strong spin–orbit coupling, and asymmetry at interfaces is the key ingredient for hosting noncollinear spin textures. Here, we investigate the characteristics and evolution of magnetic domain structures in thin Fe3GeTe2 nanolayers as a function of temperature, applied magnetic field, and specimen thickness using advanced magnetic electron microscopy. Specifically, electron holography analyses reveal the spin configurations of Bloch-type, zero-field-stabilized magnetic bubbles in 20-nm-thick Fe3GeTe2 nanolayers at cryogenic temperature. In situ Lorentz transmission electron microscopy measurements further provide detailed magnetic phase diagrams of noncollinear spin textures, including magnetic spirals and bubbles in Fe3GeTe2 as a function of temperature, applied magnetic field, and specimen thickness. We further estimate the micromagnetic parameters of Fe3GeTe2, such as anisotropy energy density and magnetization at specific specimen temperature using the critical thicknesses measured from Lorentz microscopy measurements. Our experimental results of magnetic domain structures in Fe3GeTe2 nanolayers reveal that due to their intrinsic highly uniaxial magnetocrystalline anisotropy, a very thin film of tens of nanometers of Fe3GeTe2 can support the spontaneous and stable formation of zero-field magnetic bubbles.
By force of habit: Self-trapping in a dynamical utility landscape
Authors: Moran José , Fosset Antoine , Luzzati Davide , Bouchaud Jean-Philippe , Benzaquen Michael
Published: May 2020

Historically, rational choice theory has focused on the utility maximization principle to describe how individuals make choices. In reality, there is a computational cost related to exploring the universe of available choices and it is often not clear whether we are truly maximizing an underlying utility function. In particular, memory effects and habit formation may dominate over utility maximization. We propose a stylized model with a history-dependent utility function, where the utility associated to each choice is increased when that choice has been made in the past, with a certain decaying memory kernel. We show that self-reinforcing effects can cause the agent to get stuck with a choice by sheer force of habit. We discuss the special nature of the transition between free exploration of the space of choice and self-trapping. We find, in particular, that the trapping time distribution is precisely a Zipf law at the transition, and that the self-trapped phase exhibits super-aging behavior.
Very large thermal rectification in ferromagnetic insulator-based superconducting tunnel junctions
Authors: Giazotto F. , Bergeret F. S.
Published: May 2020

We investigate electronic thermal rectification in ferromagnetic insulator-based superconducting tunnel junctions. Ferromagnetic insulators coupled to superconductors are known to induce sizable spin splitting in the superconducting density of states and also lead to efficient spin filtering if used as tunnel barriers. The combination of spin splitting and spin filtering is shown to yield a substantial amount of self-amplification of the electronic heat diode effect due to breaking of the electron-hole symmetry in the system, which is added to the thermal asymmetry of the junction. Large spin splitting and large spin polarization (≳90%) can potentially lead to thermal rectification efficiencies exceeding ∼5×104% for realistic parameters in a suitable temperature range, thereby outperforming up to a factor of ∼250, the heat diode effect achievable with conventional superconducting tunnel junctions. These results are relevant for improved control of heat currents in innovative phase-coherent caloritronic nanodevices and for enhanced thermal management of quantum circuits at the nanoscale.
High fibre selection by roe deer (Capreolus capreolus): evidence of ruminal microbiome adaption to seasonal and geographical differences in nutrient composition
Authors: Dahl Sarah-Alica , Hudler Martina , Windisch Wilhelm , Bolduan Carmen , Brugger Daniel , König Andreas
Published: May 2020

Context. The European roe deer owes its ability to digest fibre to its microbiome. This is made up of many different species at different levels of abundance and with different differentiations. In Europe, the roe deer is often classified as a so-called ‘concentrate selector’. This term has often been interpreted by different researchers to mean a selector of either protein- or energy-rich food. According to various studies, this selection behaviour is due to the low abundance of fibre-degrading microorganisms. Aims. The aim of the present study was to determine the concentration of crude nutrients in the rumen of roe deer, with the focus on the fibre fractions, and to show changes among seasons and between habitats. Furthermore, the aim was to find out how far the composition of the ruminal microbiota adapts to these changes. Methods. From 2011 to 2014, we collected the rumens of 245 roe deer in two Bavarian habitat types, a forest and an agricultural habitat. The crude nutrient contents and the size of the total microbiome and the proportions of individual genera were determined in the rumen content. Key results. The average annual concentration of crude fibre in the ingested food is 26–30% and this rises to 38% in certain months. The forest roe deer had the highest proportions of crude fibre in their food and the concentrations of other nutrients were also highly dependent on the season and habitat. Furthermore, the animals also have far less protein in their rumen content than often assumed. The total number of microorganisms in the rumens of the forest deer is significantly higher than in animals living in the agricultural area. The number of microorganisms was highest in the forest roe deer in winter, and in the roe deer from the agricultural area in summer. Clear connections can also be seen between individual groups of microorganisms and particular crude nutrients. The high crude-fibre concentration leads to a high number of fibre-degrading microorganisms, such as, for example, anaerobic fungi or the Ruminococcus flavefaciens. Conclusions. The results showed a high adaptability of the animals to a fibre-rich diet. The microbiome adapts very well to the respective nutrient availabilities. This, in turn, is what allows the roe deer to adapt so readily to diverse habitats and environmental conditions. Implications. Due to the generally high concentrations of fibre, combined with the high numbers of fibre-degraders in the rumen, we suggest that, from now on, we should talk of a roe deer as being a ‘selector’ or ‘browser’ rather than a ‘concentrate selector’.
Directed flow of photons in Cu

+

Au collisions at RHIC
Authors: Dasgupta Pingal , Chatterjee Rupa , Srivastava Dinesh K
Published: May 2020

The Cu + Au collisions are expected to provide interesting new aspects in the understanding of anisotropic flow in heavy ion collisions due to asymmetric initial geometry on the transverse plane as well as due to the significant difference in number of participants in the two colliding nuclei. We calculate directed flow coefficient v
1 of thermal photons from 200 A GeV Cu + Au collisions at RHIC using a hydrodynamic model with fluctuating initial conditions and compare the results with the elliptic and triangular flow parameters. The photon v
1(p
T) is found to be non-zero and shows a different nature compared to the elliptic and triangular flow parameters as a function of p
T. We see a negative v
1 for p
T < 2 GeV/c, which becomes positive and rises slowly with larger p
T (>2 GeV/c) values. The QGP radiation completely dominates the v
1 in the region 1 < p
T < 6 GeV/c whereas, the contribution from hadronic phase is only marginal. In addition, the v
1 is found to be more sensitive to the initial formation time of the plasma compared to the elliptic and triangular flow parameters. Photon v
1 from Au + Au collisions is also calculated and compared with the v
1 from Cu + Au collisions. These results indicate that fluctuations play the most significant role in the determination of photon v
1 as the results from symmetric and symmetric collisions are found to be close to each other. We suggest that a simultaneous measurements of photon v

n
coefficients (n = 1, 2, 3) can provide valuable information about the initial state produced in heavy ion collisions.
Personalized automatic sleep staging with single-night data: a pilot study with Kullback–Leibler divergence regularization
Authors: Phan Huy , Mikkelsen Kaare , Chén Oliver Y , Koch Philipp , Mertins Alfred , Kidmose Preben , De Vos Maarten
Published: May 2020

Objective: Brain waves vary between people. This work aims to improve automatic sleep staging for longitudinal sleep monitoring via personalization of algorithms based on individual characteristics extracted from sleep data recorded during the first night. Approach: As data from a single night are very small, thereby making model training difficult, we propose a Kullback–Leibler (KL) divergence regularized transfer learning approach to address this problem. We employ the pretrained SeqSleepNet (i.e. the subject independent model) as a starting point and finetune it with the single-night personalization data to derive the personalized model. This is done by adding the KL divergence between the output of the subject independent model and it of the personalized model to the loss function during finetuning. In effect, KL-divergence regularization prevents the personalized model from overfitting to the single-night data and straying too far away from the subject independent model. Main results: Experimental results on the Sleep-EDF Expanded database consisting of 75 subjects show that sleep staging personalization with single-night data is possible with help of the proposed KL-divergence regularization. On average, we achieve a personalized sleep staging accuracy of 79.6%, a Cohen’s kappa of 0.706, a macro F1-score of 73.0%, a sensitivity of 71.8%, and a specificity of 94.2%. Significance: We find both that the approach is robust against overfitting and that it improves the accuracy by 4.5 percentage points compared to the baseline method without personalization and 2.2 percentage points compared to it with personalization but without regularization.
Bose–Einstein condensation on curved manifolds
Authors: Móller Natália S , dos Santos F Ednilson A , Bagnato Vanderlei S , Pelster Axel
Published: May 2020

Here we describe a weakly interacting Bose gas on a curved smooth manifold, which is embedded in the three-dimensional Euclidean space. To this end we start by considering a harmonic trap in the normal direction of the manifold, which confines the three-dimensional Bose gas in the vicinity of its surface. Following the notion of dimensional reduction as outlined in [L Salasnich et al, Phys. Rev. A 65, 043614 (2002)], we assume a large enough trap frequency so that the normal degree of freedom of the condensate wave function can be approximately integrated out. In this way we obtain an effective condensate wave function on the quasi-two-dimensional surface of the curved manifold, where the thickness of the cloud is determined self-consistently. For the particular case when the manifold is a sphere, our equilibrium results show how the chemical potential and the thickness of the cloud increase with the interaction strength. Furthermore, we determine within a linear stability analysis the low-lying collective excitations together with their eigenfrequencies, which turn out to reveal an instability for attractive interactions.
Charging and energy fluctuations of a driven quantum battery
Authors: Crescente A , Carrega M , Sassetti M , Ferraro D
Published: May 2020

We consider a quantum battery modelled as a set of N independent two-level quantum systems driven by a time dependent classical source. Different figures of merit, such as stored energy, time of charging and energy quantum fluctuations during the charging process, are characterized in a wide range of parameters, by means of numerical approach and suitable analytical approximation scheme. Particular emphasis is put on the role of different initial conditions, describing the preparation state of the quantum battery, as well as on the sensitivity to the functional form of the external time-dependent drive. It is shown that an optimal charging protocol, characterized by fast charging time and the absence of charging fluctuations, can be achieved starting from the ground state of each two-level system, while other pure preparation states are less efficient. Moreover, we argue that a periodic train of peaked rectangular pulses can lead to fast charging. This study aims at providing a useful theoretical background in view of future experimental solid-state implementations.
Divertor impurity seeding with a new feedback control scheme for
maintaining good core confinement in grassy-ELM H-mode regime with tungsten
monoblock divertor in EAST
Authors: Xu G.S. , Yuan Q.P. , Li K.D. , Wang L. , Xu J.C. , Yang Q.Q. , Duan Y.M. , Meng L.Y. , Yang Z.S. , Ding F. , Liu J.B. , Guo H.Y. , Wang H.Q. , Eldon D. , Tao Y.Q. , Wu K. , Yan N. , Ding R. , Wang Y.F. , Ye Y. , Zhang L. , Zhang T. , Zang Q. , Li Y.Y. , Liu H.Q. , Jia G.Z. , Liu X.J. , Si H. , Li E.Z. , Zeng L. , Qian J.P. , Lin S.Y. , Xu L.Q. , Wang H.H. , Gong X.Z. , Wan B.N.
Published: May 2020

Small perturbations and strong impurity exhaust capability associated with the
small grassy ELMs render the grassy-ELM regime a suitable candidate for
achieving steady-state H-mode operation with a radiative divertor, especially in
a metal-wall device, such as the Experimental Advanced Superconducting Tokamak
(EAST). As the degradation of pedestal performance with excessive divertor
impurity seeding or accumulation tends to be accompanied with significantly
increased radiation near the divertor X point, feedback control of the absolute
extreme ultraviolet (AXUV) radiation near the X point has been employed to
maintain the confinement property in EAST. However, the absolute value of the
AXUV radiation at the outer target varies with plasma conditions as during the
divertor detachment process. Thus, a new feedback-control scheme has been
recently developed and applied to grassy-ELM H-mode plasmas in EAST to achieve
stationary partial detachment while maintaining good global energy confinement
with H
98,y2 >1. In this scheme, electron
temperatures (T
et) measured by divertor Langmuir
probes are used to identify the onset of detachment, and then the plasma control
system (PCS) switches to the feedback control of one channel of AXUV radiation
near the X point, where a steep gradient in the radiation profile is present.
The feedback is performed through pulse-width-modulated duty cycle of a piezo
valve to seed impurities with mixed gas (50% Ne and 50% D2) from the
outer target plate near the strike point in the upper tungsten monoblock
divertor. T
et near the strike point is maintained in
the range of 5–8 eV, and peak surface temperature on the outer target
plate (T
IR,peak) is suppressed and maintained at
∼180 °C, based on infrared camera measurements. The plasma stored energy
maintains nearly constant over the entire feedback-control period. It thus
offers a highly promising plasma control scenario suitable for long-pulse
high-performance H-mode operation in EAST, which is potentially applicable to
future steady-state fusion reactors as an integrated solution for the control of
both ELM-induced transient and steady-state divertor heat loads while
maintaining good core confinement.
The Effect of Smoking on the Association between Long-Term Alcohol Consumption and Dyslipidemia in a Middle-Aged and Older Population
Authors: Lee Kyueun , Kim Jihye
Published: May 2020

Aims

The joint effects of chronic alcohol consumption and smoking on dyslipidemia remain unclear in a prospective design. This study examined the effect of smoking on the association between long-term alcohol consumption and risk of incident dyslipidemia.

Methods

A total of 4467 participants (1866 men and 2601women) aged 40–69 years without dyslipidemia were recruited at baseline. Alcohol consumption was assessed biennially using a questionnaire and classified as light, moderate or heavy drinker. Smoking status was examined at baseline and categorized into non-smokers and current smokers. Dyslipidemia was defined as the presence of one or more of following: hypertriglyceridemia (triglyceride ≥200 mg/dL), hypercholesterolemia (total cholesterol ≥240 mg/dL), low high-density lipoprotein-cholesterol (HDL-C) < 40 mg/dL, or high low-density lipoprotein cholesterol ≥160 mg/dL.

Results

During a follow-up period of 12 years, 2872 (64.3%) participants developed dyslipidemia. In non-smoking men, light or moderate alcohol consumption was associated with a lower risk of incident dyslipidemia such as hypertriglyceridemia and hypercholesterolemia, whereas this association was not observed in current smoking men. Unlike non-smokers, the duration of alcohol drinking > 10 years was associated with a higher risk of hypertriglyceridemia in current smoking men (hazard ratio = 1.57, 95% confidence interval: 1.07–2.30, P = 0.020). In addition, alcohol consumption was inversely associated with low HDL-C regardless of smoking status. In women, alcohol consumption was inversely associated with dyslipidemia hypercholesterolemia and low HDL-C regardless of alcohol amount.

Conclusion

Smoking crucially confounds the association between long-term alcohol consumption and dyslipidemia, particularly in hypertriglyceridemia and hypercholesterolemia.
Parasitologist-level classification of apicomplexan parasites and host cell with deep cycle transfer learning (DCTL)
Authors: Li Sen , Yang Qi , Jiang Hao , Cortés-Vecino Jesús A , Zhang Yang
Published: May 2020

Motivation

Apicomplexan parasites, including Toxoplasma, Plasmodium and Babesia, are important pathogens that affect billions of humans and animals worldwide. Usually a microscope is used to detect these parasites, but it is difficult to use microscopes and clinician requires to be trained. Finding a cost-effective solution to detect these parasites is of particular interest in developing countries, in which infection is more common.

Results

Here, we propose an alternative method, deep cycle transfer learning (DCTL), to detect apicomplexan parasites, by utilizing deep learning-based microscopic image analysis. DCTL is based on observations of parasitologists that Toxoplasma is banana-shaped, Plasmodium is generally ring-shaped, and Babesia is typically pear-shaped. Our approach aims to connect those microscopic objects (Toxoplasma, Plasmodium, Babesia and erythrocyte) with their morphological similar macro ones (banana, ring, pear and apple) through a cycle transfer of knowledge. In the experiments, we conduct DCTL on 24 358 microscopic images of parasites. Results demonstrate high accuracy and effectiveness of DCTL, with an average accuracy of 95.7% and an area under the curve of 0.995 for all parasites types. This article is the first work to apply knowledge from parasitologists to apicomplexan parasite recognition, and it opens new ground for developing AI-powered microscopy image diagnostic systems.

Availability and implementation

Code and dataset available at https://github.com/senli2018/DCTL.

Supplementary information

Supplementary data are available at Bioinformatics online.
TheMacroptilium gracilespecies complex (Fabaceae, Papilionoideae): an integrative taxonomic study based on morphological, molecular and ecological data
Authors: Berlingeri Chiara , Crespo Manuel B , Calles Teodardo
Published: May 2020

Macroptilium gracile (Phaseolinae, Fabaceae) sensu lato is an extremely diverse species distributed from Mexico to Argentina. The taxonomic and nomenclatural history of the species is confusing, due to existing contrasting treatments. All 15 names corresponding to 12 taxa that have often been considered akin to M. gracile were selected here to clarify the identity of this taxonomic aggregate, using morphological, molecular and biogeographical analyses. Univariate and multivariate statistical analyses (nMDS and cluster) of 67 morphological traits were performed on a sample of 109 herbarium sheets. Maximum parsimony and Bayesian inference analyses were conducted using plastid (rpl32-trnL(UAG), trnK-matK-trnK) and nuclear (ITS/5.8S) DNA sequence data on a sample of 31 accessions belonging to taxa of the M. gracile complex and other Macroptilium spp., using three members of related genera (Phaseolus and Vigna) as outgroups. A database with plant locations per taxa was used to elaborate a distribution map, and the potential habitats were estimated through nMDS analysis. Our morphological, molecular and biogeographic results suggest that members of the M. gracile complex belong to three taxonomic entities, for which a new arrangement is proposed accepting Macroptilium gracile (with two varieties) and M. campestre, including two new nomenclatural combinations (M. gracile var. subcoriaceum and M. campestre). Types for all cited names are indicated where available (with a new lectotype designation). Morphological, ecological and distributional data are reported for each accepted taxon.
Definitions and classification of malformations of cortical development: practical guidelines
Authors: Severino Mariasavina , Geraldo Ana Filipa , Utz Norbert , Tortora Domenico , Pogledic Ivana , Klonowski Wlodzimierz , Triulzi Fabio , Arrigoni Filippo , Mankad Kshitij , Leventer Richard J , Mancini Grazia M S , Barkovich James A , Lequin Maarten H , Rossi Andrea
Published: May 2020

Malformations of cortical development are a group of rare disorders commonly manifesting with developmental delay, cerebral palsy or seizures. The neurological outcome is extremely variable depending on the type, extent and severity of the malformation and the involved genetic pathways of brain development. Neuroimaging plays an essential role in the diagnosis of these malformations, but several issues regarding malformations of cortical development definitions and classification remain unclear. The purpose of this consensus statement is to provide standardized malformations of cortical development terminology and classification for neuroradiological pattern interpretation. A committee of international experts in paediatric neuroradiology prepared systematic literature reviews and formulated neuroimaging recommendations in collaboration with geneticists, paediatric neurologists and pathologists during consensus meetings in the context of the European Network Neuro-MIG initiative on Brain Malformations (https://www.neuro-mig.org/). Malformations of cortical development neuroimaging features and practical recommendations are provided to aid both expert and non-expert radiologists and neurologists who may encounter patients with malformations of cortical development in their practice, with the aim of improving malformations of cortical development diagnosis and imaging interpretation worldwide.