bluuebunny/crossref_metadata_2025 huggingface dataset:
Reliable protection scheme for PV integrated microgrid using an ensemble classifier approach with real‐time validation
Authors: Manohar Murli , Koley Ebha , Ghosh Subhojit
Published: October 2017

The need for enhancing grid resilience has led to wider acceptance of photo voltaic (PV) integrated microgrid. The variation in fault current during grid connected and islanding operation makes the microgrid protection task challenging. A protection scheme based on ensemble of classifiers has been devised by exploiting the effectiveness of a classifier set coupled with voting strategy. Unlike the existing classifier‐based approaches involving single classifier, the ensemble‐based approach is insensitive to the biasness of individual classifier and dimension/size of dataset. The proposed scheme is formulated to simultaneously perform the tasks of mode detection, fault detection/classification, section identification and location. The scheme is able to discriminate between faults and power quality disturbances, which avoids unintended false tripping. Along with accuracy, the reliability assessment of proposed scheme has been carried out using two indices, i.e. dependability and security for different faults, operating mode and contingencies. For evaluating the reliability of the fault locator, a stochastic approach (Monte‐Carlo simulation) has been adopted. The simulation results justify the applicability of the proposed ensemble classifier‐based scheme for complete protection and reliable operation of microgrids with PV penetration. The scheme also has been validated for real‐time settings using hardware in loop simulations.
Chandra and ALMA observations of the nuclear activity in two strongly lensed star-forming galaxies
Authors: Massardi M. , Enia A. F. M. , Negrello M. , Mancuso C. , Lapi A. , Vignali C. , Gilli R. , Burkutean S. , Danese L. , De Zotti G.
Published: October 2017

Aim. According to coevolutionary scenarios, nuclear activity and star formation play relevant roles in the early stages of galaxy formation. We aim at identifying them in high-redshift galaxies by exploiting high-resolution and high-sensitivity X-ray and millimeter-wavelength data to confirm the presence or absence of star formation and nuclear activity and describe their relative roles in shaping the spectral energy distributions and in contributing to the energy budgets of the galaxies.

Methods. We present the data, model, and analysis in the X-ray and millimeter (mm) bands for two strongly lensed galaxies, SDP.9 (HATLAS J090740.0-004200) and SDP.11 (HATLAS J091043.1-000322), which we selected in the Herschel-ATLAS catalogs for their excess emission in the mid-IR regime at redshift ≳1.5. This emission suggests nuclear activity in the early stages of galaxy formation. We observed both of them with Chandra ACIS-S in the X-ray regime and analyzed the high-resolution mm data that are available in the ALMA Science Archive for SDP.9. By combining the information available in mm, optical, and X-ray bands, we reconstructed the source morphology.

Results. Both targets were detected in the X-ray, which strongly indicates highly obscured nuclear activity. ALMA observations for SDP.9 for the continuum and CO(6-5) spectral line with high resolution (0.02 arcsec corresponding to ~65 pc at the distance of the galaxy) allowed us to estimate the lensed galaxy redshift to a better accuracy than pre-ALMA estimates (1.5753 ± 0.0003) and to model the emission of the optical, millimetric, and X-ray band for this galaxy. We demonstrate that the X-ray emission is generated in the nuclear environment, which strongly supports that this object has nuclear activity. On the basis of the X-ray data, we attempt an estimate of the black hole properties in these galaxies.

Conclusions. By taking advantage of the lensing magnification, we identify weak nuclear activity associated with high-z galaxies with high star formation rates. This is useful to extend the investigation of the relationship between star formation and nuclear activity to two intrinsically less luminous high-z star-forming galaxies than was possible so far. Given our results for only two objects, they alone cannot constrain the evolutionary models, but provide us with interesting hints and set an observational path toward addressing the role of star formation and nuclear activity in forming galaxies.
Epistemic responsibility as an edifying force in academic research: investigating the moral challenges and opportunities of an impact agenda in the UK and Australia
Authors: Chubb Jennifer , Reed Mark
Published: October 2017

The requirement to anticipate, articulate and evaluate the impact of research is a growing part of academic labor. A research impact agenda in the UK and Australia reflects a drive from Governments to see a return on the public investment of research. Some view this as symptomatic of a marketised higher education system, in which knowledge is a commodity as opposed to an object of intrinsic value and dismiss the latter view as nostalgic and unrealistic. Within a research context where knowledge continues to be politicized, long-standing philosophical concerns concerning the value of knowledge and its purpose are re-rehearsed and revisited. Discourse concerning the preservation of freedom in an age of increased accountability can be seen to give rise to increased moral and emotional dissonance amongst pockets of the academic community. At the same time, the academic community can be largely seen to possess a strong moral sense of epistemic responsibility toward the societal contribution of useful knowledge. This piece, based upon research that examined the philosophical challenges with respect to an impact agenda facing academics in the UK and Australia, will serve to provoke further discussion about the challenges posed by an impact agenda whilst also acting as a provocation for academics to locate and harness a sense of epistemic responsibility in order to respond to the impact agenda. This may enable a departure away from narrow conceptions of knowledge and its instrumentalism, thus supporting the academic community and its actors in forming a more holistic view of the value of knowledge within this context.
Axial magnetic field injection in magnetized liner inertial fusion
Authors: Gourdain P.-A. , Adams M. B. , Davies J. R. , Seyler C. E.
Published: October 2017

MagLIF is a fusion concept using a Z-pinch implosion to reach thermonuclear fusion. In current experiments, the implosion is driven by the Z-machine using 19 MA of electrical current with a rise time of 100 ns. MagLIF requires an initial axial magnetic field of 30 T to reduce heat losses to the liner wall during compression and to confine alpha particles during fusion burn. This field is generated well before the current ramp starts and needs to penetrate the transmission lines of the pulsed-power generator, as well as the liner itself. Consequently, the axial field rise time must exceed hundreds of microseconds. Any coil capable of being submitted to such a field for that length of time is inevitably bulky. The space required to fit the coil near the liner, increases the inductance of the load. In turn, the total current delivered to the load decreases since the voltage is limited by driver design. Yet, the large amount of current provided by the Z-machine can be used to produce the required 30 T field by tilting the return current posts surrounding the liner, eliminating the need for a separate coil. However, the problem now is the field penetration time, across the liner wall. This paper discusses why skin effect arguments do not hold in the presence of resistivity gradients. Numerical simulations show that fields larger than 30 T can diffuse across the liner wall in less than 60 ns, demonstrating that external coils can be replaced by return current posts with optimal helicity.
Deep kernel learning method for SAR image target recognition
Authors: Chen Xiuyuan , Peng Xiyuan , Duan Ran , Li Junbao
Published: October 2017

With the development of deep learning, research on image target recognition has made great progress in recent years. Remote sensing detection urgently requires target recognition for military, geographic, and other scientific research. This paper aims to solve the synthetic aperture radar image target recognition problem by combining deep and kernel learning. The model, which has a multilayer multiple kernel structure, is optimized layer by layer with the parameters of Support Vector Machine and a gradient descent algorithm. This new deep kernel learning method improves accuracy and achieves competitive recognition results compared with other learning methods.
Effect of in-plane strain anisotropy on (011) epitaxial BaTiO3 and PbTiO3 thin films
Authors: Ma Wenhui , Wang Fei
Published: October 2017

Misfit strain phase diagrams of single-domain (011) epitaxial BaTiO3 and PbTiO3 thin films are computed using a thermodynamic phenomenological approach. In the case of (001) epitaxial films, the two orthogonal in-plane misfit strains are equivalent. For (011) epitaxial films, however, the two substrate constraints exert quantitatively different influences due to crystal anisotropy. Effects of preferential strain relaxation and arbitrary in-plane strains are investigated, and similarity and contrast of BaTiO3 and PbTiO3 phase diagrams are revealed. Impact of anisotropy of in-plane constraint on polarization, dielectric and piezoelectric properties is explored, and the calculated structural transitions and out-of-plane lattice strain are compared with relevant theoretical and experimental data reported in the literature.
Excitation energies with spin-orbit couplings using equation-of-motion coupled-cluster singles and doubles eigenvectors
Authors: Bokhan Denis , Perera Ajith , Trubnikov Dmitrii N. , Bartlett Rodney J.
Published: October 2017

A method of calculation of excited states with spin-orbit couplings, which utilizes left and right eigenvectors of equation-of-motion coupled-cluster singles and doubles model has been formulated and implemented. The spin-orbit interactions are introduced by using the spin-orbit mean field approximation of the Briet-Pauli Hamiltonian. In order to evaluate all the necessary matrix elements, a scheme based on the diagrammatic representation of the second-quantized form of the spin-orbit interaction operator and the standard rules of second-quantized algebra is presented. We posit that this scheme is general and much simpler to use than the often used rules derived for the configuration state functions by using the Wigner-Eckart theorem. We show that the spin-orbit coupled states (i.e., target relativistic states) must satisfy specific conditions in order to classify them according to the double group symmetry. This interrelation between the structure of the target relativistic states and its double group symmetry is discussed in detail. An algorithm to classify the target states according to the irreducible representation of the double group symmetry is offered and implemented. Numerical tests for several atoms and molecules show good agreement of predicted and experimental spin-orbit splittings of the target excited states.
Investigation of the development of dielectric-barrier discharge instabilities in excimer lamp
Authors: Bouchachia A. , Belasri A. , Harrache Z. , Amir Aid D.
Published: October 2017

This work represents a study of the formation and propagation of the streamer during a pulse in a plasma cell with dielectric barriers containing a Ne/Xe gas mixture. It is based on a longitudinal mono-dimensional model of the dielectric barrier discharge. In this model, we show the possibility of streamers development in the cathode sheath and its propagation during the plasma formation stage. The model gives the spatiotemporal variations of the propagation speed, the electric field, and the charged particle density of the streamer's head.
Ti film deposition process of a plasma focus: Study by an experimental design
Authors: Inestrosa-Izurieta M. J. , Moreno J. , Davis S. , Soto L.
Published: October 2017

The plasma generated by plasma focus (PF) devices have substantially different physical characteristics from another plasma, energetic ions and electrons, compared with conventional plasma devices used for plasma nanofabrication, offering new and unique opportunities in the processing and synthesis of Nanomaterials. This article presents the use of a plasma focus of tens of joules, PF-50J, for the deposition of materials sprayed from the anode by the plasma dynamics in the axial direction. This work focuses on the determination of the most significant effects of the technological parameters of the system on the obtained depositions through the use of a statistical experimental design. The results allow us to give a qualitative understanding of the Ti film deposition process in our PF device depending on four different events provoked by the plasma dynamics: i) an electric erosion of the outer material of the anode; ii) substrate ablation generating an interlayer; iii) electron beam deposition of material from the center of the anode; iv) heat load provoking clustering or even melting of the deposition surface.
Systematic design of active spaces for multi-reference calculations of singlet–triplet gaps of organic diradicals, with benchmarks against doubly electron-attached coupled-cluster data
Authors: Stoneburner Samuel J. , Shen Jun , Ajala Adeayo O. , Piecuch Piotr , Truhlar Donald G. , Gagliardi Laura
Published: October 2017

Singlet−triplet gaps in diradical organic π-systems are of interest in many applications. In this study, we calculate them in a series of molecules, including cyclobutadiene and its derivatives and cyclopentadienyl cation, by using correlated participating orbitals within the complete active space (CAS) and restricted active space (RAS) self-consistent field frameworks, followed by second-order perturbation theory (CASPT2 and RASPT2). These calculations are evaluated by comparison with the results of doubly electron-attached (DEA) equation-of-motion (EOM) coupled-cluster (CC) calculations with up to 4-particle–2-hole (4p-2h) excitations. We find active spaces that can accurately reproduce the DEA-EOMCC(4p-2h) data while being small enough to be applicable to larger organic diradicals.
The effect of varying the introduction mode of reactants on electrical, physical and thermal stability properties of polypyrrole synthesized with CTAB
Authors: Vahidi K. , Jalili Y. Seyed , Salar Elahi A.
Published: October 2017

Electrical and physical properties of conducting polymers are generally enhanced via modifications in the chemical structure of the final product, there appears to be a void in facile physical means to improve the materials’ properties without utilizing additives which remain in the final product as impurity. In this research, we presented the effect of altering the introduction method of reactants in emulsion polymerization of PPy with CTAB on the electrical, physical and stability properties of the final product. Three samples were prepared: one via a conventional non-emulsion polymerization method as a reference sample, the second in which the reactants were added simultaneously and the goal sample in which the monomer/surfactant mixture was allowed to be stirred separately then it was added dropwise to the oxidant solution. UV-vis, FTIR, 4-point Van Derr Paw probe, FESEM and contact angle measurements were used to investigate optical, electrical, physical, heat stability and solubility properties of the samples. The results indicate that since in the final sample a higher portion of the reaction occurred on the hydrophobic interior of the micelles, the final material had a lower number of structural and chemical defects which leads to higher conjugation lengths and thus higher properties such as a 9-fold difference in conductivity and improved solubility and thermal stability. The novelty of this work lies in the simplicity of the alterations that have been made, both in terms of optimization of the synthetic route which had been thoroughly investigated and also in terms of the differences that our work poses compared to that of the others; namely: the parameters have been thoroughly studied and analyzed but not the method of addition as in our experiments the sequence of addition and the method of addition of the reactants were altered to observe their effect on the physical and the electronic properties which has led to the conclusion that in case of drop-wise addition, a larger portion of the reaction occurs inside the micelles hence giving rise to inhibition of the defect-producing chemical bonds which is supported by the analysis in our investigations.
Ultrasmooth metal thin films on curved fused silica by laser polishing
Authors: Anemone Gloria , Weingarten Christian , Al Taleb Amjad , Prieto Carlos , Farías Daniel
Published: October 2017

The fabrication of atomically smooth metal films on supporting oxides is a quite demanding task, since most physical vapor deposition methods used on metals do not work properly on oxide substrates. Here, we report an alternative procedure, based on performing laser polishing of a fused silica substrate before depositing the metallic thin film. This reduces the RMS surface roughness of fused silica by ca. 33%, and increases the maximum grain size of the metallic film from 200 nm to 1200 nm. The method has been applied to a fused silica parabolic lens, which has been coated with a graphene-terminated Ru thin film. The reduction of surface roughness caused by laser polishing leads to the formation of ultrasmooth Ru thin films. Crystallinity and subnanometer roughness of the metal coating are demonstrated by the observation of He diffraction from a macroscopically curved surface.
Towards filtered drag force model for non-cohesive and cohesive particle-gas flows
Authors: Ozel Ali , Gu Yile , Milioli Christian C. , Kolehmainen Jari , Sundaresan Sankaran
Published: October 2017

Euler-Lagrange simulations of gas-solid flows in unbounded domains have been performed to study sub-grid modeling of the filtered drag force for non-cohesive and cohesive particles. The filtered drag forces under various microstructures and flow conditions were analyzed in terms of various sub-grid quantities: the sub-grid drift velocity, which stems from the sub-grid correlation between the local fluid velocity and the local particle volume fraction, and the scalar variance of solid volume fraction, which is a measure to identify the degree of local inhomogeneity of volume fraction within a filter volume. The results show that the drift velocity and the scalar variance exert systematic effects on the filtered drag force. Effects of particle and domain sizes, gravitational accelerations, and mass loadings on the filtered drag are also studied, and it is shown that these effects can be captured by both sub-grid quantities. Additionally, the effect of cohesion force through the van der Waals interaction on the filtered drag force is investigated, and it is found that there is no significant difference on the dependence of the filtered drag coefficient of cohesive and non-cohesive particles on the sub-grid drift velocity or the scalar variance of solid volume fraction. The assessment of predictabilities of sub-grid quantities was performed by correlation coefficient analyses in a priori manner, and it is found that the drift velocity is superior. However, the drift velocity is not available in “coarse-grid” simulations and a specific closure is needed. A dynamic scale-similarity approach was used to model drift velocity but the predictability of that model is not entirely satisfactory. It is concluded that one must develop a more elaborate model for estimating the drift velocity in “coarse-grid” simulations.
Stable room-temperature thallium bromide semiconductor radiation detectors
Authors: Datta A. , Fiala J. , Becla P. , Motakef Shariar
Published: October 2017

Thallium bromide (TlBr) is a highly efficient ionic semiconductor with excellent radiation detection properties. However, at room temperature, TlBr devices polarize under an applied electric field. This phenomenon not only degrades the charge collection efficiency of the detectors but also promotes chemical reaction of the metal electrodes with bromine, resulting in an unstable electric field and premature failure of the device. This drawback has been crippling the TlBr semiconductor radiation detector technology over the past few decades. In this exhaustive study, this polarization phenomenon has been counteracted using innovative bias polarity switching schemes. Here the highly mobile Br− species, with an estimated electro-diffusion velocity of 10−8 cm/s, face opposing electro-migration forces during every polarity switch. This minimizes the device polarization and availability of Br− ions near the metal electrode. Our results indicate that it is possible to achieve longer device lifetimes spanning more than 17 000 h (five years of 8 × 7 operation) for planar and pixelated radiation detectors using this technique. On the other hand, at constant bias, 2500 h is the longest reported lifetime with most devices less than 1000 h. After testing several biasing switching schemes, it is concluded that the critical bias switching frequency at an applied bias of 1000 V/cm is about 17 μHz. Using this groundbreaking result, it will now be possible to deploy this highly efficient room temperature semiconductor material for field applications in homeland security, medical imaging, and physics research.
Room temperature 2D electron gas at the (001)-SrTiO3 surface
Authors: Gonzalez Sara , Mathieu Claire , Copie Olivier , Feyer Vitaliy , Schneider Claus M. , Barrett Nicholas
Published: October 2017

Functional oxides and phenomena such as a 2D electron gas (2DEG) at oxide interfaces represent potential technological breakthroughs for post-CMOS electronics. Non-invasive techniques are required to study the surface chemistry and electronic structure, underlying their often unique electrical properties. The sensitivity of photoemission electron microscopy to chemistry and electronic structure makes it an invaluable tool for probing the near surface region of microscopic regions and domains of functional materials. We present results demonstrating a room temperature 2DEG at the (001)-SrTiO3 surface. The 2DEG is switched on by soft X-ray irradiation.
Enhanced stability of magnetoelectric gyrators under high power conditions
Authors: Leung Chung Ming , Zhuang Xin , Gao Min , Tang Xiao , Xu Junran , Li Jiefang , Zhang Jitao , Srinivasan G. , Viehland D.
Published: October 2017

In this study, three different coil-based magnetoelectric (ME) gyrators of different geometries, including gyrators with high power output, have been designed and characterized. These included two magnetostrictive/piezoelectric/magnetostrictive (M-P-M) and one piezoelectric/magnetostrictive/piezoelectric (P-M-P) type ME gyrators, which consisted of nickel zinc ferrite (NZFO) and lead zirconate titanate (PZT) ceramic plates. Compared with M-P-M ME gyrators, the P-M-P ones exhibited a higher power efficiency (η) of 85% when operated at resonance under an optimal magnetic bias field (HBias) of 40 Oe at low power conditions. It retained a relatively high efficiency of η = 79% under a high input power density of 2.87 W/cm3. A low reduction in the magnetomechanical coupling and mechanical quality (k33,m and Qm) factors of the NZFO ferrite layer in the ME gyrator explains the resilience of the P-M-P type structure with increasing power drive. The findings open the possibility of using ME gyrators in high power applications.
Variation of index of refraction in cobalt doped ZnO nanostructures
Authors: Kaphle Amrit , Hari Parameswar
Published: October 2017

One dimensional zinc oxide (ZnO) nanostructures were fabricated using a low temperature chemical bath deposition technique. The ZnO nanorods were doped with cobalt using cobalt nitrate with cobalt concentration varying from 0% to 9%. The scanning electron microscope images of the nanostructures indicate that the diameter of ZnO nanorods increased with the increase in cobalt doping concentration. The optical characterizations of the doped and undoped samples were performed by investigating the variation in the band gap, the Urbach energy, the index of refraction, and the extinction coefficient with cobalt concentration. The dispersion of index of refraction in cobalt doped ZnO nanostructures was modeled based on the Wemple DiDomenico single oscillator model. The interband oscillator energy and the dispersion energy were estimated for different cobalt doped ZnO nanorod samples based on this model.
Analysis of rheological properties of Herschel-Bulkley fluid for pulsating flow of blood in ω-shaped stenosed artery
Authors: Abbas Z. , Shabbir M. S. , Ali N.
Published: October 2017

In the present article, we examined the pulsating flow of blood in the tapered ω-shaped stenosed arterial segment. The Herschel-Bulkley fluid model is used to represent the non-Newtonian characteristics of blood in narrow arteries. The equation governing the present flow is modelled by assuming that the flow is unsteady and one dimensional. Regular perturbation method is used to find the first order expression of various flow variables. The temporal and axial distributions of velocity, wall shear stress, volumetric flux and resistance to the flow are displayed graphically. The effects of various involved parameters on the radius of plug flow region are also discussed. A comparison between the flow of blood in single symmetric and ω-shaped stenotic regions of the arteries is also analyzed.
A fast and efficient size separation method for haploid embryonic stem cells
Authors: Freimann Remo , Wutz Anton
Published: October 2017

Hemizygous mutations introduced in haploid genomes can directly expose a phenotype, thus facilitating gene function analysis and forward genetic screening. Recently, mammalian haploid cells could be derived from mouse, rat, monkey, and human embryos and have been applied to screens of cellular mechanisms including cell signaling, pathogen host factors, and developmental pathways. Notably, haploid cell cultures have an intrinsic tendency for diploidization and, thus, require periodic cell sorting. Here, we report a method for rapid purification of haploid mouse embryonic stem cells from mixed cell populations with high viability and yield. Our method uses membranes with micrometer pores for force-free separation and facilitates enrichment of haploid cells without flow cytometry. The separation method simplifies maintaining haploid cell cultures and has further applications in establishing haploid cell lines from embryos and isolating cell cycle phases of mammalian cells.
Dispersion of the resonant second order nonlinearity in 2D semiconductors probed by femtosecond continuum pulses
Authors: Mokim Mohammad , Card Adam , Sah Bindeshwar , Ganikhanov Feruz
Published: October 2017

We demonstrate an effective microspectroscopy technique by tracing the dispersion of second order nonlinear susceptibility (χ(2)) in a monolayer tungsten diselenide (WSe2). The χ(2) dispersion obtained with better than 3 meV photon energy resolution showed peak value being within 6.3-8.4×10-19 m2/V range. We estimate the fundamental bandgap to be at 2.2 eV. Sub-structure in the χ(2) dispersion reveals a contribution to the nonlinearity due to exciton transitions with exciton binding energy estimated to be at 0.7 eV.
Non-linear stress response of non-gap-spanning magnetic chains suspended in a Newtonian fluid under oscillatory shear test: A direct numerical simulation
Authors: Hashemi M. R. , Manzari M. T. , Fatehi R.
Published: October 2017

A direct numerical simulation approach is used to investigate the effective non-linear viscoelastic stress response of non-gap-spanning magnetic chains suspended in a Newtonian fluid. The suspension is confined in a channel and the suspended clusters are formed under the influence of a constant external magnetic field. Large amplitude oscillatory shear (LAOS) tests are conducted to study the non-linear rheology of the system. The effect of inertia on the intensity of non-linearities is discussed for both magnetic and non-magnetic cases. By conducting magnetic sweep tests, the intensity and quality of the non-linear stress response are studied as a function of the strength of the external magnetic field. The Chebyshev expansion of the stress response is used to quantify the non-linear intra-cycle behaviour of the suspension. It is demonstrated that the system shows a strain-softening behaviour while the variation of the dynamic viscosity is highly sensitive to the external magnetic field. In a series of strain sweep tests, the overall non-linear viscoelastic behaviour of the system is also investigated for both a constant frequency and a constant strain-rate amplitude. It is shown that the intra-cycle behaviour of the system is different from its inter-cycle behaviour under LAOS tests.
Synthesis and properties of 2-mono- and 2,3-disubstituted thiochromones
Authors: Sosnovskikh Vyacheslav Ya.
Published: October 2017

Data on the methods of synthesis, chemical reactivity and biological activity of 2-mono- and 2,3-disubstituted thiochromones are integrated and described systematically. Particular sections of the review address 2-arylthiochromones (thioflavones), 2-alkyl- and 2,3-dialkyl-substituted thiochromones and functionalized thiochromones with electron-donating (amino, hydroxy or mercapto group) or electron-withdrawing (cyano, nitro, formyl or carboxyl group or halogen atom) groups in positions 2 and/or 3. Analysis of published data indicates that chemical transformations of thiochromones, including functional derivatives, are rarely accompanied by thiopyrone ring opening, which distinguishes these compounds from representatives of the chromone system. Reaction conditions and product yields and data on the biological activities of some compounds of this class are given.

The bibliography includes 189 references.
Poly(organo)phosphazenes: recent progress in the synthesis and applications in tissue engineering and drug delivery
Authors: Khan Rizwan Ullah , Wang Li , Yu Haojie , Zain-ul-Abdin  , Akram Muhammad , Wu Jialiang , Haroon Muhammad , Ullah Raja Summe , Deng Zheng , Xia Xia
Published: October 2017

It is a highly desirable goal of researchers to develop effective biomaterials with minimum recovery time and affordable treatment expense for tissue engineering and drug delivery. In this scenario, numerous synthetic and natural polymers have been used. Among those synthetic polymers, polyorganophosphazenes (POPs) have got much attention as highly promising candidates for applications in tissue engineering and drug delivery. Polyorganophosphazenes are hybrid polymers containing inorganic backbone consisting of alternating nitrogen and phosphorus atoms with two organic side groups. POPs possess a wide range of unique properties, i.e., synthetic flexibility, biocompatibility, osteocompatibility, osteoinductivity, sustainability and degradability into harmless end products with predictable degradation rate and adjustable mechanical strength. Moreover, their tunable hydrophilic/hydrophobic and stimuli responsive properties add extra points to their use in biomedical applications. In addition, their various polymeric forms, i.e., microspheres, nano/microfibres, micelles, membranes, polymersomes, hydrogels and nano-conjugate linear polymers provide different carriers to efficiently deliver various hydrophilic/hydrophobic therapeutic agents both in vitro and in vivo. This review focuses on the most recent progress that has been made in the synthesis and applications of POPs in tissue engineering and their different polymeric forms used for drug delivery. Moreover, we have also summarized the effect of different side groups on the overall efficiency of POPs.

The bibliography includes 239 references.
Polyelectrolyte multilayers: preparation and applications
Authors: Izumrudov Vladimir A. , Mussabayeva Binur Kh. , Murzagulova Kunnaz B.
Published: October 2017

The review concerns the results of studies on the synthesis of polyelectrolyte coatings on charged surfaces. These coatings represent nanostructured systems with clearly defined tendency to self-assembly and self-adjustment, which is of particular interest for materials science, biomedicine and pharmacology. A breakthrough in this area of knowledge is due to the development and introduction of a new technique, so-called layer-by-layer (LbL) deposition of nanofilms. The technique is very simple, viz., multilayers are formed as a result of alternating treatment of a charged substrate of arbitrary shape with water-salt solutions of differently charged polyelectrolytes. Nevertheless, efficient use of the LbL method to fabricate nanofilms requires meeting certain conditions and limitations that were revealed in the course of research on model systems. Prospects for applications of polyelectrolyte layers in various fields are discussed.

The bibliography includes 58 references.
Corrigendum to: Increased high molecular weight adiponectin, but decreased total adiponectin and kisspeptin, in central precocious puberty compared with aged-matched prepubertal girls
Authors: Sitticharoon Chantacha , Sukharomana Maynart , Likitmaskul Supawadee , Churintaraphan Malika , Maikaew Pailin
Published: October 2017

The aim of the present study was to compare serum leptin, kisspeptin, total adiponectin, high molecular weight (HMW) adiponectin and neuropeptide Y (NPY) levels between girls with central precocious puberty (CPP; n=26, 7–9.5 years old) and age-matched controls (n=29) including or excluding obese girls. Leptin and NPY levels were comparable between CPP and control girls. Kisspeptin levels were lower in the CPP than control group, and were positively correlated with oestrogen in the control group and with systolic and diastolic blood pressure in the CPP group. Kisspeptin levels were negatively correlated with FSH and LH in the CPP group. Total adiponectin levels were lower in CPP than control girls, and were negatively correlated with Tanner stage and body mass index, but positively correlated with the quantitative insulin sensitivity check index in the control group. HMW adiponectin was higher in the CPP than control group, and was positively correlated with Tanner stage and LH in all girls. Total adiponectin had a strong positive correlation with HMW adiponectin in the CPP group (r=0.915) compared with the control group (r=0.371). In conclusion, kisspeptin may be associated with increased oestrogen in prepubertal girls, but with increased blood pressure in girls with CPP. In girls entering puberty, HMW adiponectin was increased and associated with reproductive parameters. Based on these observations, HMW adiponectin probably plays an essential role in the initiation of puberty and is a candidate marker for the prediction of CPP.
Temporal variation in the population characteristics of harvested wolverine (Gulo gulo) in northwestern Canada
Authors: Kukka Piia M. , Jung Thomas S. , Robitaille Jean-François , Schmiegelow Fiona K. A.
Published: October 2017

Context Wolverines (Gulo gulo) are harvested for fur in northern Canada; however, the impacts of harvest are poorly known. Additionally, wolverine population data are largely absent for much of their northern range. Demographic data collected from harvested wolverines provide information on the vulnerability and variability of different sex and age cohorts to harvest, which, in turn, may have implications for harvest sustainability. Aims We examined the temporal variability of different sex and age cohorts in wolverine harvest among years, and within the harvest season, in Yukon, Canada. We also examined the pregnancy status of female wolverines in relation to the harvest date, so as to evaluate the impact of the harvest-season length on breeding wolverines. Methods We determined the sex and age composition of harvested wolverines via dissections of 655 carcasses collected from 2005 to 2014. We determined the reproductive status and fetal measurements for female wolverines via dissections of reproductive tracts. Key results The harvest consisted mostly of males, particularly of young individuals. The sex ratio of harvested animals did not fluctuate significantly, but we observed variation in the age structure among years. The age structure varied within the harvest season (November to March), with a greater proportion of adults being harvested in late winter. Active gestation was evident in females harvested after mid-January, and near-term or postpartum females were harvested during late February and March. Conclusions Late winter harvest is likely to have a more significant impact on populations than is early winter harvest, because of increased harvest of adults and breeding females. Wolverine harvest season extends to the onset of the denning season in late February and March, indicating a concern for ethical harvest. Implications Limiting the legal harvest season to early winter may contribute to improved harvest sustainability and protection of breeding wolverines in northern latitudes.
NOX4-dependent neuronal autotoxicity and BBB breakdown explain the superior sensitivity of the brain to ischemic damage
Authors: Casas Ana I. , Geuss Eva , Kleikers Pamela W. M. , Mencl Stine , Herrmann Alexander M. , Buendia Izaskun , Egea Javier , Meuth Sven G. , Lopez Manuela G. , Kleinschnitz Christoph , Schmidt Harald H. H. W.
Published: October 2017

Significance

Why the brain is uniquely sensitive to hypoxia and which cells are involved is incompletely understood. Here we identify that, upon ischemic stroke, in endothelial cells and neurons the reactive oxygen-forming NADPH oxidase 4 (NOX4) causes breakdown of the BBB and neuronal cell death. This mechanism is unique to the brain and not found in other forms of ischemia in the body. Genetic deletion of either cell type (endothelial or neuronal) or pharmacological inhibition of NOX4 leads to a significant reduction of infarct volume and direct neuroprotection. This mechanism explains the unique vulnerability of the hypoxic brain compared with other organs and provides a clear rationale for first-in-class neuroprotective therapies in stroke.
Climate-driven changes in functional biogeography of Arctic marine fish communities
Authors: Frainer André , Primicerio Raul , Kortsch Susanne , Aune Magnus , Dolgov Andrey V. , Fossheim Maria , Aschan Michaela M.
Published: October 2017

Significance

Arctic marine ecosystems are experiencing a rapid biogeographic change following the highest warming rates observed around the globe in recent decades. Currently, there are no studies of how the observed shifts in species composition are affecting Arctic marine ecosystem functioning at a biogeographic scale. We address this issue via functional biogeography and show that increasing temperatures and reduced ice coverage are associated with the borealization of Arctic fish communities. We find that large body-sized piscivorous and semipelagic boreal species are replacing small-bodied benthivorous Arctic species, likely affecting biomass production in the benthic and pelagic compartments and their coupling. The documented speed and magnitude of climate-driven borealization will profoundly alter ecosystem functioning in the Arctic.
Environmental and geographic variables are effective surrogates for genetic variation in conservation planning
Authors: Hanson Jeffrey O. , Rhodes Jonathan R. , Riginos Cynthia , Fuller Richard A.
Published: October 2017

Significance

To protect biodiversity for the long term, nature reserves and other protected areas need to represent a broad range of different genetic types. However, genetic data are expensive and time-consuming to obtain. Here we show that freely available environmental and geographic variables can be used as effective surrogates for genetic data in conservation planning. This means that conservation planners can, with some confidence, design protected area systems to represent intraspecific genetic diversity without investing in expensive programs to obtain and analyze genetic data.
Replication of early and recent Zika virus isolates throughout mouse brain development
Authors: Rosenfeld Amy B. , Doobin David J. , Warren Audrey L. , Racaniello Vincent R. , Vallee Richard B.
Published: October 2017

Significance

Zika virus (ZIKV) infection has been associated with multiple pathologies of the central nervous system (CNS) including microcephaly, Guillain-Barré syndrome, lissencephaly, the loss of white and gray matter volume and acute myelitis. Using organotypic brain slice cultures, we determined that ZIKV replicates across different embryonic developmental stages, and viral infection can disrupt proper brain development leading to congenital CNS complications. These data illustrate that all lineages of ZIKV tested are neurotropic, and that infection may disrupt neuronal migration during brain development. The results expand our understanding of neuropathologies associated with congenital Zika virus syndrome.
Hydrogen-induced change in microstructure and properties of steels: 18Cr10Mn–0.4N vis-à-vis 18Cr10Ni
Authors: Kim Han-Jin , Phaniraj M. P. , Cho Min-Kyung , Song Eun Ju , Baek Seung-Wook , Kim Gyeung-Ho , Suh Jin-Yoo , Lee Joonho , Han Heung Nam
Published: October 2017

Cr–Mn–N stainless steels have a cost and strength advantage over conventional Cr–Ni stainless steels. In this study microstructure and mechanical property of hydrogen-charged 18Cr10Mn-0.4N was compared with 18Cr10Ni austenitic stainless steel. This is the first such study for 18Cr10Mn–0.4N austenitic stainless steel. Electron microscopy was used to compare the deformed microstructure of the uncharged and hydrogen-charged specimens. The results are discussed in view of the current knowledge on hydrogen embrittlement. The 18Cr10Mn–0.4N steel suffered higher embrittlement mainly because it absorbed moref hydrogen.
Caffeine ingestion enhances Wingate performance: a meta‐analysis
Authors: Grgic Jozo
Published: October 2017

The positive effects of caffeine ingestion on aerobic performance are well‐established; however, recent findings are suggesting that caffeine ingestion might also enhance components of anaerobic performance. A commonly used test of anaerobic performance and power output is the 30‐second Wingate test. Several studies explored the effects of caffeine ingestion on Wingate performance, with equivocal findings. To elucidate this topic, this paper aims to determine the effects of caffeine ingestion on Wingate performance using meta‐analytic statistical techniques. Following a search through PubMed/MEDLINE, Scopus, and SportDiscus®, 16 studies were found meeting the inclusion criteria (pooled number of participants = 246). Random‐effects meta‐analysis of standardized mean differences (SMD) for peak power output and mean power output was performed. Study quality was assessed using the modified version of the PEDro checklist. Results of the meta‐analysis indicated a significant difference (p = .005) between the placebo and caffeine trials on mean power output with SMD values of small magnitude (0.18; 95% confidence interval: 0.05, 0.31; +3%). The meta‐analysis performed for peak power output indicated a significant difference (p = .006) between the placebo and caffeine trials (SMD = 0.27; 95% confidence interval: 0.08, 0.47 [moderate magnitude]; +4%). The results from the PEDro checklist indicated that, in general, studies are of good and excellent methodological quality. This meta‐analysis adds on to the current body of evidence showing that caffeine ingestion can also enhance components of anaerobic performance. The results presented herein may be helpful for developing more efficient evidence‐based recommendations regarding caffeine supplementation.
pH of endophagosomes controls association of their membranes with Vps34 and PtdIns(3)P levels
Authors: Naufer Amriya , Hipolito Victoria E.B. , Ganesan Suriakarthiga , Prashar Akriti , Zaremberg Vanina , Botelho Roberto J. , Terebiznik Mauricio R.
Published: October 2017

Phagocytosis of filamentous bacteria occurs through tubular phagocytic cups (tPCs) and takes many minutes to engulf these filaments into phagosomes. Contravening the canonical phagocytic pathway, tPCs mature by fusing with endosomes. Using this model, we observed the sequential recruitment of early and late endolysosomal markers to the elongating tPCs. Surprisingly, the regulatory early endosomal lipid phosphatidylinositol-3-phosphate (PtdIns(3)P) persists on tPCs as long as their luminal pH remains neutral. Interestingly, by manipulating cellular pH, we determined that PtdIns(3)P behaves similarly in canonical phagosomes as well as endosomes. We found that this is the product of a pH-based mechanism that induces the dissociation of the Vps34 class III phosphatidylinositol-3-kinase from these organelles as they acidify. The detachment of Vps34 stops the production of PtdIns(3)P, allowing for the turnover of this lipid by PIKfyve. Given that PtdIns(3)P-dependent signaling is important for multiple cellular pathways, this mechanism for pH-dependent regulation of Vps34 could be at the center of many PtdIns(3)P-dependent cellular processes.
‘It is not only an artist village, it is much more than that’1. The binding and dividing effects of the arts on a community
Authors: van der Vaart Gwenda , van Hoven Bettina , Huigen Paulus P P
Published: October 2017

The value of ‘the arts’ in community development is increasingly being recognized. This paper contributes to emerging insights on the various impacts of the arts on communities by highlighting when and how they can have binding and dividing effects on a community. We draw on a participatory research project conducted in Pingjum, a village in the Netherlands that hosts many cultural activities and in which many artists live. We discuss how the arts in Pingjum influence the community in the village. In our discussion, we pay attention to the sense of community that the arts generate, the meeting opportunities they provide and how the community is engaged by some artists. Our study shows that the influence of the arts is context-dependent, with the arts having both binding and dividing effects on the community in Pingjum. In terms of the value of the arts for community development, we emphasize three key issues: that the arts (i) do not have only advantages for a community; (ii) do not engage the entire community; and (iii) could potentially contribute to community fragmentation. Given these issues, we argue that the arts should be considered as one of several supportive means in community development processes. Ideally, they are integrated into a wider community development strategy and planning, and exist alongside other associations and activities in a community. In this way, the arts can contribute to the robustness of a community and assist it in developing the capacity and resources to flourish.
A numerical method for the approximation of reachable sets of linear control systems
Authors: Shao Lizhen , Zhao Fangyuan , Hu Guangda
Published: October 2017

In this article, a numerical method for the approximation of reachable sets of linear control systems is discussed. First a continuous system is transformed into a discrete one with Runge–Kutta methods. Then based on Benson’s outer approximation algorithm for solving multiobjective optimization problems, we propose a variant of Benson’s algorithm to sandwich the reachable set of the discrete system with an inner approximation and an outer approximation. By specifying an approximation error, the quality of the approximations measured in Hausdorff distance can be directly controlled. Furthermore, we use an illustrative example to demonstrate the working of the algorithm. Finally, computational experiments illustrate the superior performance of our proposed algorithm compared to a recent algorithm in the literature.