bluuebunny/crossref_metadata_2025 huggingface dataset:
Testing of WS2 Nanoparticles Functionalized by a Humin-Like Shell as Lubricant Additives
Authors: Sade Hagit , Moshkovich Alexey , Lellouche Jean-Paul , Rapoport Lev
Published: January 2018

Nanoparticles of transition metal dichalcogenides (TMDC) have been known to reduce friction and wear when added to oil-type liquid lubricants. Aggregation limits the ability of the nanoparticles to penetrate into the interface between the two rubbing surfaces—an important factor in friction reduction mechanisms. Doping has been successfully used to reduce agglomeration, but it must be done in the production process of the nanoparticles. The use of surface-functionalized nanoparticles is less common than doping. Nonetheless, it has the potential to reduce agglomeration and thereby improve the reduction of friction and wear. In this study, we present the results of preliminary tribological ball-on-flat tests performed with WS2 nanoparticles functionalized by a humin-like conformal shell, as additives to polyalphaolefin-4 (PAO-4) oil. We tested WS2 inorganic nanotubes (INTs) and two grades of inorganic fullerene-like nanoparticles (IFs). The shell/coating was found to improve friction reduction for IFs but not for INTs through better dispersion in the oil. The thicker the coating on the IFs, the less agglomerated they were. Coated industrial-grade IFs were found, by far, to be the best additive for friction reduction. We suggest the combination between reduced agglomeration and poor crystallinity as the reason for this result.
The Suppressive Activity of Fucofuroeckol-A Derived from Brown Algal Ecklonia stolonifera Okamura on UVB-Induced Mast Cell Degranulation
Authors: Vo Thanh , Kim Se-Kwon , Ryu BoMi , Ngo Dai , Yoon Na-Young , Bach Long , Hang Nguyen , Ngo Dai
Published: January 2018

UV light, especially UVB, is known as a trigger of allergic reaction, leading to mast cell degranulation and histamine release. In this study, phlorotannin Fucofuroeckol-A (F-A) derived from brown algal Ecklonia stolonifera Okamura was evaluated for its protective capability against UVB-induced allergic reaction in RBL-2H3 mast cells. It was revealed that F-A significantly suppress mast cell degranulation via decreasing histamine release as well as intracellular Ca2+ elevation at the concentration of 50 μM. Moreover, the inhibitory effect of F-A on IL-1β and TNF-α productions was also evidenced. Notably, the protective activity of F-A against mast cell degranulation was found due to scavenging ROS production. Accordingly, F-A from brown algal E. stolonifera was suggested to be promising candidate for its protective capability against UVB-induced allergic reaction.
Phytotherapy in the Management of Diabetes: A Review
Authors: Governa Paolo , Baini Giulia , Borgonetti Vittoria , Cettolin Giulia , Giachetti Daniela , Magnano Anna , Miraldi Elisabetta , Biagi Marco
Published: January 2018

Phytotherapy has long been a source of medicinal products and over the years there have been many attempts to use herbal medicines for the treatment of diabetes. Several medicinal plants and their preparations have been demonstrated to act at key points of glucidic metabolism. The most common mechanisms of action found include the inhibition of α-glucosidase and of AGE formation, the increase of GLUT-4 and PPARs expression and antioxidant activity. Despite the large amount of literature available, the actual clinical effectiveness of medicinal plants in controlling diabetes-related symptoms remains controversial and there is a crucial need for stronger evidence-based data. In this review, an overview of the medicinal plants, which use in the management of diabetes is supported by authoritative monographs, is provided. References to some species which are currently under increasing clinical investigation are also reported.
Organozinc Precursor-Derived Crystalline ZnO Nanoparticles: Synthesis, Characterization and Their Spectroscopic Properties
Authors: Liang Yucang , Wicker Susanne , Wang Xiao , Erichsen Egil , Fu Feng
Published: January 2018

Crystalline ZnO-ROH and ZnO-OR (R = Me, Et, iPr, nBu) nanoparticles (NPs) have been successfully synthesized by the thermal decomposition of in-situ-formed organozinc complexes Zn(OR)2 deriving from the reaction of Zn[N(SiMe3)2]2 with ROH and of the freshly prepared Zn(OR)2 under an identical condition, respectively. With increasing carbon chain length of alkyl alcohol, the thermal decomposition temperature and dispersibility of in-situ-formed intermediate zinc alkoxides in oleylamine markedly influenced the particle sizes of ZnO-ROH and its shape (sphere, plate-like aggregations), while a strong diffraction peak-broadening effect is observed with decreasing particle size. For ZnO-OR NPs, different particle sizes and various morphologies (hollow sphere or cuboid-like rod, solid sphere) are also observed. As a comparison, the calcination of the fresh-prepared Zn(OR)2 generated ZnO-R NPs possessing the particle sizes of 5.4~34.1 nm. All crystalline ZnO nanoparticles are characterized using X-ray diffraction analysis, electron microscopy and solid-state 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. The size effect caused by confinement of electrons’ movement and the defect centres caused by unpaired electrons on oxygen vacancies or ionized impurity heteroatoms in the crystal lattices are monitored by UV-visible spectroscopy, electron paramagnetic resonance (EPR) and photoluminescent (PL) spectroscopy, respectively. Based on the types of defects determined by EPR signals and correspondingly defect-induced probably appeared PL peak position compared to actual obtained PL spectra, we find that it is difficult to establish a direct relationship between defect types and PL peak position, revealing the complication of the formation of defect types and photoluminescence properties.
Enhanced and Selective Antiproliferative Activity of Methotrexate-Functionalized-Nanocapsules to Human Breast Cancer Cells (MCF-7)
Authors: De Oliveira Catiúscia , Büttenbender Sabrina , Prado Willian , Beckenkamp Aline , Asbahr Ana , Buffon Andréia , Guterres Silvia , Pohlmann Adriana
Published: January 2018

Methotrexate is a folic acid antagonist and its incorporation into nanoformulations is a promising strategy to increase the drug antiproliferative effect on human breast cancer cells by overexpressing folate receptors. To evaluate the efficiency and selectivity of nanoformulations containing methotrexate and its diethyl ester derivative, using two mechanisms of drug incorporation (encapsulation and surface functionalization) in the in vitro cellular uptake and antiproliferative activity in non-tumoral immortalized human keratinocytes (HaCaT) and in human breast carcinoma cells (MCF-7). Methotrexate and its diethyl ester derivative were incorporated into multiwall lipid-core nanocapsules with hydrodynamic diameters lower than 160 nm and higher drug incorporation efficiency. The nanoformulations were applied to semiconfluent HaCaT or MCF-7 cells. After 24 h, the nanocapsules were internalized into HaCaT and MCF-7 cells; however, no significant difference was observed between the nanoformulations in HaCaT (low expression of folate receptors), while they showed significantly higher cellular uptakes than the blank-nanoformulation in MCF-7, which was the highest uptakes observed for the drug functionalized-nanocapsules. No antiproliferative activity was observed in HaCaT culture, whereas drug-containing nanoformulations showed antiproliferative activity against MCF-7 cells. The effect was higher for drug-surface functionalized nanocapsules. In conclusion, methotrexate-functionalized-nanocapsules showed enhanced and selective antiproliferative activity to human breast cancer cells (MCF-7) being promising products for further in vivo pre-clinical evaluations.
Prospective Study of Dietary Zinc Intake and Risk of Cardiovascular Disease in Women
Authors: Milton Abul , Vashum Khanrin , McEvoy Mark , Hussain Sumaira , McElduff Patrick , Byles Julie , Attia John
Published: January 2018

Several animal and human studies have shown that zinc is associated with cellular damage and cardiac dysfunction. This study aims to investigate dietary zinc and the zinc-iron ratio, as predictors of incident cardiovascular disease (CVD) in a large longitudinal study of mid-age Australian women (aged 50–61 years). Data was self-reported and validated food frequency questionnaires were used to assess dietary intake. Energy-adjusted zinc was ranked using quintiles and predictors of incident CVD were examined using stepwise logistic regression. After six years of follow-up, 320 incident CVD cases were established. A positive association between dietary zinc intake, zinc-iron ratio and risk of CVD was observed even after adjusting for potential dietary and non-dietary confounders. Compared to those with the lowest quintile of zinc, those in the highest quintile (Odds Ratio (OR) = 1.67, 95% Confidence Interval (CI) = 1.08–2.62) and zinc-iron ratio (OR = 1.72, 95% CI = 1.05–2.81) had almost twice the odds of developing CVD (p trend = 0.007). This study shows that high dietary zinc intake and zinc-iron ratio is associated with a greater incidence of CVD in women. Further studies are required detailing the source of zinc and iron in diet and their precise roles when compared to other essential nutrients.
Dietary Supplements: Regulatory Challenges and Research Resources
Authors: Dwyer Johanna , Coates Paul , Smith Michael
Published: January 2018

Many of the scientific and regulatory challenges that exist in research on the safety, quality and efficacy of dietary supplements are common to all countries as the marketplace for them becomes increasingly global. This article summarizes some of the challenges in supplement science and provides a case study of research at the Office of Dietary Supplements at the National Institutes of Health, USA, along with some resources it has developed that are available to all scientists. It includes examples of some of the regulatory challenges faced and some resources for those who wish to learn more about them.
Block Copolymer Elastomer with Graphite Filler: Effect of Processing Conditions and Silane Coupling Agent on the Composite Properties
Authors: Panaitescu Denis , Gabor Raluca , Nicolae Cristian , Parau Anca , Vitelaru Catalin , Raditoiu Valentin , Chipara Mircea
Published: January 2018

The control of morphology and interface in poly(styrene-ethylene/butylene-styrene) (SEBS) composites with graphitic fillers is extremely important for the design of piezoresistive sensors for body motion or flexible temperature sensors. The effects of a high amount of graphite (G) and silane coupling agent on the morphology and properties of SEBS composites with anisotropic mechanical properties are reported. The physical and chemical bonding of silane to both G and SEBS surface was proved by EDX and TGA results; this improved interface influenced both the thermal and mechanical properties of the composite. The vinyltriethoxysilane (VS) promoted the formation of char residue and, being tightly bound to both SEBS and G, did not show separate decomposition peak in the TGA curve of composites. The mechanical properties were measured on two perpendicular directions and were improved by both the addition of VS and the increased amount of G; however, the increase of storage modulus due to orientation (from 5 to 15 times depending on the composition and direction of the test) was more important than that provided by the increase of G concentration, which was a maximum of four times that obtained for 15 wt % graphite. A mechanism to explain the influence of G content and treatment on the variation of storage modulus and tan δ depending on the direction of the test was also proposed.
Wind in Complex Terrain—Lidar Measurements for Evaluation of CFD Simulations
Authors: Risan Andrea , Lund John , Chang Chi-Yao , Sætran Lars
Published: January 2018

Computational Fluid Dynamics (CFD) is widely used to predict wind conditions for wind energy production purposes. However, as wind power development expands into areas of even more complex terrain and challenging flow conditions, more research is needed to investigate the ability of such models to describe turbulent flow features. In this study, the performance of a hybrid Reynolds-Averaged Navier-Stokes (RANS)/Large Eddy Simulation (LES) model in highly complex terrain has been investigated. The model was compared with measurements from a long range pulsed Lidar, which first were validated with sonic anemometer data. The accuracy of the Lidar was considered to be sufficient for validation of flow model turbulence estimates. By reducing the range gate length of the Lidar a slight additional improvement in accuracy was obtained, but the availability of measurements was reduced due to the increased noise floor in the returned signal. The DES model was able to capture the variations of velocity and turbulence along the line-of-sight of the Lidar beam but overestimated the turbulence level in regions of complex flow.
3-D Water Vapor Tomography in Wuhan from GPS, BDS and GLONASS Observations
Authors: Dong Zhounan , Jin Shuanggen
Published: January 2018

Three-dimensional water vapor can be reconstructed from Global Navigation Satellite System (GNSS) observations, which can study 3-D profile variations of atmospheric water vapor and climate. However, there is a large uncertainty of water vapor tomography from single GPS system observations due to limited satellites. The rapid development of multi-GNSS, including China’s Beidou Navigation Satellite System (BDS) and Russia’s GLONASS, has greatly improved the geometric distribution of satellite ray-path signals, which may improve the performance of water vapor tomography by combining multi-GNSS. In this paper, 3-D water vapor tomography results are the first time obtained using multi-GNSS data from Continuously Operating Reference Stations (CORS) network in Wuhan, China, whose performances are validated by radiosonde and the latest ECMWF ERA5 reanalysis products. The results show that the integrated multi-GNSS can pronouncedly increase the number of effective signals, and 3-D water vapor results are better than those from the GPS-only system, improving by 5% with GPS + GLONASS or GPS + GLONASS + BDS, while BDS has results that are not improved too much. Therefore, multi-GNSS will enhance the reliability and accuracy of 3-D water vapor tomography, which has more potential applications in the future.
Evaluation of Apple Maturity with Two Types of Dielectric Probes
Authors: Kafarski Marcin , Wilczek Andrzej , Szypłowska Agnieszka , Lewandowski Arkadiusz , Pieczywek Piotr , Janik Grzegorz , Skierucha Wojciech
Published: January 2018

The observed dielectric spectrum of ripe apples in the last period of shelf-life was analyzed using a multipole dielectric relaxation model, which assumes three active relaxation processes: primary α-process (water relaxation) and two secondary processes caused by solid-water-ion interactions α’ (bound water relaxations), as well as β’ (Maxwell-Wagner effect). The performance of two designs of the dielectric probe was compared: a classical coaxial open-ended probe (OE probe) and an open-ended probe with a prolonged central conductor in a form of an antenna (OE-A-probe). The OE-A probe increases the measurement volume and consequently extends the range of applications to other materials, like granulated agricultural products, soils, or liquid suspensions. However, its measurement frequency range is limited as compared to the OE probe because, above 1.5 GHz, the probe with the antenna generates higher propagation modes and the applied calibrations and calculations are not sufficient. It was shown that data from measurements using the OE-A probe gave slightly stronger correlations with apples’ quality parameters than using the typical OE probe. Additionally, we have compared twelve multipole fitting models with different combinations of poles (eight three-pole and four two-pole models). It was shown that the best fit is obtained using a two-pole model for data collected for the OE-A probe and a three-pole model for the OE probe, using only Cole-Cole poles in both cases.
Analysis and Optimization of a Novel 2-D Magnet Array with Gaps and Staggers for a Moving-Magnet Planar Motor
Authors: Wang Yang , Chen Xuedong , Luo Xin , Zeng Lizhan
Published: January 2018

This paper presents a novel 2-D magnet array with gaps and staggers, which is especially suitable for magnetically levitated planar motor with moving magnets. The magnetic flux density distribution is derived by Fourier analysis and superposition. The influences of gaps and staggers on high-order harmonics and flux density were analyzed, and the optimized design is presented. Compared with the other improved structures based on traditional Halbach magnet arrays, the proposed design has the lowest high-order harmonics percentage, and the characteristics of flux density meet the demand of high acceleration in horizontal directions. It is also lightweight and easy to manufacture. The proposed magnet array was built, and the calculation results have been verified with experiment.
Accurate 3D Positioning for a Mobile Platform in Non-Line-of-Sight Scenarios Based on IMU/Magnetometer Sensor Fusion
Authors: Hellmers Hendrik , Kasmi Zakaria , Norrdine Abdelmoumen , Eichhorn Andreas
Published: January 2018

In recent years, a variety of real-time applications benefit from services provided by localization systems due to the advent of sensing and communication technologies. Since the Global Navigation Satellite System (GNSS) enables localization only outside buildings, applications for indoor positioning and navigation use alternative technologies. Ultra Wide Band Signals (UWB), Wireless Local Area Network (WLAN), ultrasonic or infrared are common examples. However, these technologies suffer from fading and multipath effects caused by objects and materials in the building. In contrast, magnetic fields are able to pass through obstacles without significant propagation errors, i.e. in Non-Line of Sight Scenarios (NLoS). The aim of this work is to propose a novel indoor positioning system based on artificially generated magnetic fields in combination with Inertial Measurement Units (IMUs). In order to reach a better coverage, multiple coils are used as reference points. A basic algorithm for three-dimensional applications is demonstrated as well as evaluated in this article. The established system is then realized by a sensor fusion principle as well as a kinematic motion model on the basis of a Kalman filter. Furthermore, a pressure sensor is used in combination with an adaptive filtering method to reliably estimate the platform’s altitude.
Simulation Model for Productivity Analysis of External Insulated Precast Concrete Wall System
Authors: Baik Ho , Kim Minju , Lee Sang-Heon , Cho Hunhee
Published: January 2018

External Insulation Finishing System (EIFS) is recognized as a suitable method for attaining energy efficiency of buildings. However, conventional EIFS is not actively applied to building construction due to additional time and cost compared with interior insulation method. Therefore, as an alternative that can contribute to active utilization of the external insulation system, this study proposes an External Insulated Precast Concrete (PC) Wall System and its simulation for performing productivity analysis. Results of this study are as follows: (1) an external insulated PC-Wall system is developed of which its insulation performance is above 40% higher than that of the conventional EIFS; (2) performance of the developed system satisfied American Standards for Testing of Materials (ASTM) and American Architectural Manufacturers Association (AAMA) standards; (3) applicability of the developed system is verified via test-bed with construction time lapsing about 40 min for each PC-Wall; and (4) CYCLONE modeling methodology is employed to perform productivity analysis of the developed system compared with conventional EIFS.
Transforming Municipal Services to Transform Cities: Understanding the Role and Influence of the Private Sector
Authors: Hughes Sara , Peterson Jacqueline
Published: January 2018

Municipal services—such as water, energy, and waste management—play a significant role in shaping the sustainability of cities. In many places, these services are also fully or partially delivered by the private sector, but we are only beginning to understand the implications this has for the politics and administration of urban sustainability initiatives. In this paper, we use the case of organics waste recycling in the Twin Cities, Minnesota to identify and discuss three ways private sector engagement can shift the political and administrative landscapes of municipal service delivery: through the presence and form of accountability mechanisms, norms and conditions for entrepreneurship, and the feasibility and appropriateness of traditional policy tools for achieving urban sustainability transformations. The analysis highlights the need to better understand best practices available to local governments for pursuing urban sustainability in the context of privatization, the importance of public sector capacity, and the potential for corporate social responsibility in municipal service delivery.
Detecting Ghost Targets Using Multilayer Perceptron in Multiple-Target Tracking
Authors: Ryu In-hwan , Won Insu , Kwon Jangwoo
Published: January 2018

This paper deals with a method for removing a ghost target that is not a real object from the output of a multiple object-tracking algorithm. This method uses an artificial neural network (multilayer perceptron) and introduces a structure, learning, verification, and evaluation method for the artificial neural network. The implemented system was tested at an intersection in a city center. Results from a 28-min measurement were 88% accurate when the multilayer perceptron for ghost target classification successfully detected the ghost targets, and 6.7% inaccurate when ghost targets were mistaken for actual targets. This method is expected to contribute to the advancement of intelligent transportation systems if the weaknesses revealed during the evaluation of the system are complemented and refined.
Mosquitoes and the Lymphatic Filarial Parasites: Research Trends and Budding Roadmaps to Future Disease Eradication
Authors: Famakinde Damilare
Published: January 2018

The mosquito-borne lymphatic filariasis (LF) is a parasitic, neglected tropical disease that imposes an unbearable human scourge. Despite the unprecedented efforts in mass drug administration (MDA) and morbidity management, achieving the global LF elimination slated for the year 2020 has been thwarted by limited MDA coverage and ineffectiveness in the chemotherapeutic intervention. Moreover, successful and sustainable elimination of mosquito-vectored diseases is often encumbered by reintroduction and resurgence emanating from human residual or new infections being widely disseminated by the vectors even when chemotherapy proves effective, but especially in the absence of effective vaccines. This created impetus for strengthening the current defective mosquito control approach, and profound research in vector–pathogen systems and vector biology has been pushing the boundaries of ideas towards developing refined vector-harnessed control strategies. Eventual implementation of these emerging concepts will offer a synergistic approach that will not only accelerate LF elimination, but also augurs well for its future eradication. This brief review focuses on advances in mosquito–filaria research and considers the emerging prospects for future eradication of LF.
Entropic Distance for Nonlinear Master Equation
Authors: Biró Tamás , Telcs András , Néda Zoltán
Published: January 2018

More and more works deal with statistical systems far from equilibrium, dominated by unidirectional stochastic processes, augmented by rare resets. We analyze the construction of the entropic distance measure appropriate for such dynamics. We demonstrate that a power-like nonlinearity in the state probability in the master equation naturally leads to the Tsallis (Havrda–Charvát, Aczél–Daróczy) q-entropy formula in the context of seeking for the maximal entropy state at stationarity. A few possible applications of a certain simple and linear master equation to phenomena studied in statistical physics are listed at the end.
Lévy Analysis of HBT Correlation Functions in s N N = 62 GeV and 39 GeV Au + Au Collisions at PHENIX
Authors: Kincses Dániel
Published: January 2018

The phase diagram of strongly interacting matter can be explored by analyzing data of heavy-ion collisions at different center of mass collision energies. For investigating the space-time structure of the hadron emission source, Bose-Einstein or HBT correlation measurements are among the best tools. In this paper we present the latest results from the PHENIX experiment of the Relativistic Heavy Ion Collider (RHIC) on such measurements in s N N = 39 GeV and 62 GeV Au + Au collisions.
Myelin Oligodendrocyte Glycoprotein-Independent Rubella Infection of Keratinocytes and Resistance of First-Trimester Trophoblast Cells to Rubella Virus In Vitro
Authors: Trinh Quang , Pham Ngan , Takada Kazuhide , Komine-Aizawa Shihoko , Hayakawa Satoshi
Published: January 2018

Rubella virus (RuV), which belongs to the family Togaviridae and genus Rubivirus, causes systemic infection in children and young adults and congenital rubella syndrome in developing fetuses if the infection occurs during pregnancy. The mechanisms of fetal infection by RuV are not completely understood. Myelin oligodendrocyte glycoprotein (MOG) is reported to be a cellular receptor for RuV; however, it is mainly expressed in the central nervous system. Therefore, it is thought that other receptors are also responsible for virus entry into susceptible cells. In this study, we found that first-trimester trophoblast cells were resistant to RuV. In addition, we showed that HaCaT cells (an immortalized keratinocyte cell line) that did not express MOG on their surface were infected with RuV. This finding is one of the first demonstrations of MOG-independent RuV infection of susceptible host cells and suggests that it is important to continue searching for alternative RuV receptors. In addition, this study reports the resistance of first-trimester trophoblast cells to RuV and suggests that utilizing an epithelial–mesenchymal transition approach to study the mechanisms of transplacental vertical RuV infection.
Visualizing the Nucleotide Addition Cycle of Viral RNA-Dependent RNA Polymerase
Authors: Wu Jiqin , Gong Peng
Published: January 2018

Viral RNA-dependent RNA polymerases (RdRPs) are a class of nucleic acid polymerases bearing unique features from global architecture to catalytic mechanisms. In recent years, numerous viral RdRP crystal structures have improved the understanding of these molecular machines, in particular, for how they carry out each nucleotide addition cycle (NAC) as directed by the RNA template. This review focuses on a visual introduction of viral RdRP NAC mechanisms through a combination of static pictures of structural models, a user-friendly software-based assembly of the structural models, and two videos illustrating key conformational changes in the NAC.
Geometric Defects and Icosahedral Viruses
Authors: Wang Joseph , Mukhopadhyay Suchetana , Zlotnick Adam
Published: January 2018

We propose that viruses with geometric defects are not necessarily flawed viruses. A geometric defect may be a reactive site. Defects may facilitate assembly, dissociation, or accessibility of cellular proteins to virion components. In single molecule studies of hepadnavirus assembly, defects and overgrowth are common features. Icosahedral alphaviruses and flaviviruses, among others, have capsids with geometric defects. Similarly, immature retroviruses, which are non-icosahedral, have numerous “errors”. In many viruses, asymmetric exposure of interior features allows for regulated genome release or supports intracellular trafficking. In these viruses, the defects likely serve a biological function. Commonly used approaches for spherical virus structure determination use symmetry averaging, which obscures defects. We suggest that there are three classes of asymmetry: regular asymmetry as might be found in a tailed phage, irregular asymmetry as found, for example, in defects randomly trapped during assembly, and dynamic asymmetry due to Brownian dynamics of virus capsids. Awareness of their presence and recent advances in electron microscopy will allow unprecedented investigation of capsid irregularities to investigate their biological relevance.
Ailanthone Promotes Human Vestibular Schwannoma Cell Apoptosis and Autophagy by Downregulation of miR-21
Authors: Yang Peizhen , Sun Dezhong , Jiang Fei
Published: January 2018

Ailanthone (AIL) is a quassinoid isolated from the traditional Chinese medicinal herb Ailanthus altissima. The antitumor activities of AIL have been reported in several cancers. The purpose of the present study was to explore the effect of AIL on vestibular schwannomas (VSs).
Various concentrations of AIL (0‐1 μM) were used to treat human primary VS cells, and then cell viability, proliferation, apoptosis, and autophagy were assessed. Expression of miR-21 in VS cells was altered by miRNA transfection. The functional actions of AIL on miR-21 dysregulated
cells were also assessed. AIL significantly reduced the viability of VS cells, and the IC50 value was 0.48 ± 0.023 μM. In response to 0.6 μM AIL, BrdU+ cell rate and cyclin D1 expression were reduced, apoptotic cell rate was increased, caspase
3 and caspase 9 were cleaved, Beclin-1 and LC3-II were accumulated, and p62 was downregulated. miR-21 was lowly expressed in AIL-treated cells, and AIL-induced apoptosis and autophagy were attenuated by miR-21 overexpression. In addition, AIL downregulated Ras and Raf and deactivated MEK,
ERK, mTOR, and p70S6K, while the downregulation and deactivation induced by AIL were reversed by miR-21 overexpression. To conclude, AIL inhibited VS cell proliferation and induced apoptosis and autophagy. The antitumor activities of AIL in VS cells were realized possibly via downregulation of miR-21 and blocking the Ras/Raf/MEK/ERK and mTOR pathways.
A Generalized Approach to Model the Spectra and Radiation Dose Rate of Solar Particle Events on the Surface of Mars
Authors: Guo Jingnan , Zeitlin Cary , Wimmer-Schweingruber Robert F. , McDole Thoren , Kühl Patrick , Appel Jan C. , Matthiä Daniel , Krauss Johannes , Köhler Jan
Published: January 2018

For future human missions to Mars, it is important to study the surface radiation environment during extreme and elevated conditions. In the long term, it is mainly galactic cosmic rays (GCRs) modulated by solar activity that contribute to the radiation on the surface of Mars, but intense solar energetic particle (SEP) events may induce acute health effects. Such events may enhance the radiation level significantly and should be detected as immediately as possible to prevent severe damage to humans and equipment. However, the energetic particle environment on the Martian surface is significantly different from that in deep space due to the influence of the Martian atmosphere. Depending on the intensity and shape of the original solar particle spectra, as well as particle types, the surface spectra may induce entirely different radiation effects. In order to give immediate and accurate alerts while avoiding unnecessary ones, it is important to model and well understand the atmospheric effect on the incoming SEPs, including both protons and helium ions. In this paper, we have developed a generalized approach to quickly model the surface response of any given incoming proton/helium ion spectra and have applied it to a set of historical large solar events, thus providing insights into the possible variety of surface radiation environments that may be induced during SEP events. Based on the statistical study of more than 30 significant solar events, we have obtained an empirical model for estimating the surface dose rate directly from the intensities of a power-law SEP spectra.
Outcomes of Grazing Impacts between Sub-Neptunes in Kepler Multis
Authors: Hwang Jason , Chatterjee Sourav , Lombardi James , Steffen Jason H. , Rasio Frederic
Published: January 2018

Studies of high-multiplicity, tightly packed planetary systems suggest that dynamical instabilities are common and affect both the orbits and planet structures, where the compact orbits and typically low densities make physical collisions likely outcomes. Since the structure of many of these planets is such that the mass is dominated by a rocky core, but the volume is dominated by a tenuous gas envelope, the sticky-sphere approximation, used in dynamical integrators, may be a poor model for these collisions. We perform five sets of collision calculations, including detailed hydrodynamics, sampling mass ratios, and core mass fractions typical in Kepler Multis. In our primary set of calculations, we use Kepler-36 as a nominal remnant system, as the two planets have a small dynamical separation and an extreme density ratio. We use an N-body code, Mercury 6.2, to integrate initially unstable systems and study the resultant collisions in detail. We use these collisions, focusing on grazing collisions, in combination with realistic planet models created using gas profiles from Modules for Experiments in Stellar Astrophysics and core profiles using equations of state from Seager et al. to perform hydrodynamic calculations, finding scatterings, mergers, and even a potential planet–planet binary. We dynamically integrate the remnant systems, examine the stability, and estimate the final densities, finding that the remnant densities are sensitive to the core masses, and collisions result in generally more stable systems. We provide prescriptions for predicting the outcomes and modeling the changes in mass and orbits following collisions for general use in dynamical integrators.
J0815+4729: A Chemically Primitive Dwarf Star in the Galactic Halo Observed with Gran Telescopio Canarias*
Authors: Aguado David S. , Hernández Jonay I. González , Prieto Carlos Allende , Rebolo Rafael
Published: January 2018

We report the discovery of the carbon-rich hyper metal-poor unevolved star J0815+4729. This dwarf star was selected from SDSS/BOSS as a metal-poor candidate and follow-up spectroscopic observations at medium resolution were obtained with the Intermediate dispersion Spectrograph and Imaging System (ISIS) at William Herschel Telescope and the Optical System for Imaging and low-intermediate-Resolution Integrated Spectroscopy (OSIRIS) at Gran Telescopio de Canarias. We use the FERRE code to derive the main stellar parameters,

T

eff

=
6215
±
82

K, and

log
g
=
4.7
±
0.5

, an upper limit to the metallicity of [Fe/H] ≤ −5.8, and a carbon abundance of [C/Fe] ≥ +5.0, while

[
α

/

Fe
]
=
0.4

is assumed. The metallicity upper limit is based on the Ca ii K line, which at the resolving power of the OSIRIS spectrograph cannot be resolved from possible interstellar calcium. The star could be the most iron-poor unevolved star known and also be among the ones with the largest overabundances of carbon. High-resolution spectroscopy of J0815+4729 will certainly help to derive other important elemental abundances, possibly providing new fundamental constraints on the early stages of the universe, the formation of the first stars, and the properties of the first supernovae.
Black Hole Formation and Fallback during the Supernova Explosion of a 40 M⊙ Star
Authors: Chan Conrad , Müller Bernhard , Heger Alexander , Pakmor Rüdiger , Springel Volker
Published: January 2018

Fallback in core-collapse supernovae is considered a major ingredient for explaining abundance anomalies in metal-poor stars and the natal kicks and spins of black holes (BHs). We present a first 3D simulation of BH formation and fallback in an “aborted” neutrino-driven explosion of a 40 solar mass zero-metallicity progenitor from collapse to shock breakout. We follow the phase up to BH formation using the relativistic CoCoNuT-FMT code. For the subsequent evolution to shock breakout we apply the moving-mesh code Arepo to core-collapse supernovae for the first time. Our simulation shows that despite early BH formation, neutrino-heated bubbles can survive for tens of seconds before being accreted, leaving them sufficient time to transfer part of their energy to sustain the shock wave as is propagates through the envelope. Although the initial net energy (∼2 Bethe) of the neutrino-heated ejecta barely equals the binding energy of the envelope,

of hydrogen are still expelled with an energy of 0.23 Bethe. We find no significant mixing and only a modest BH kick and spin, but speculate that stronger effects could occur for slightly more energetic explosions or progenitors with less tightly bound envelopes.
Extending Counter-streaming Motion from an Active Region Filament to a Sunspot Light Bridge
Authors: Wang Haimin , Liu Rui , Li Qin , Liu Chang , Deng Na , Xu Yan , Jing Ju , Wang Yuming , Cao Wenda
Published: January 2018

We analyze high-resolution observations from the 1.6 m telescope at Big Bear Solar Observatory that cover an active region filament. Counter-streaming motions are clearly observed in the filament. The northern end of the counter-streaming motions extends to a light bridge, forming a spectacular circulation pattern around a sunspot, with clockwise motion in the blue wing and counterclockwise motion in the red wing, as observed in the Hα off-bands. The apparent speed of the flow is around 10–60 km s−1 in the filament, decreasing to 5–20 km s−1 in the light bridge. The most intriguing results are the magnetic structure and the counter-streaming motions in the light bridge. Similar to those in the filament, the magnetic fields show a dominant transverse component in the light bridge. However, the filament is located between opposed magnetic polarities, while the light bridge is between strong fields of the same polarity. We analyze the power of oscillations with the image sequences of constructed Dopplergrams, and find that the filament’s counter-streaming motion is due to physical mass motion along fibrils, while the light bridge’s counter-streaming motion is due to oscillation in the direction along the line-of-sight. The oscillation power peaks around 4 minutes. However, the section of the light bridge next to the filament also contains a component of the extension of the filament in combination with the oscillation, indicating that some strands of the filament are extended to and rooted in that part of the light bridge.
1I/‘Oumuamua as a Tidal Disruption Fragment from a Binary Star System
Authors: Ćuk Matija
Published: January 2018

1I/‘Oumuamua is the first known interstellar small body, probably being only about 100 m in size. Against expectations based on comets, ‘Oumuamua does not show any activity and has a very elongated figure, and it also exhibits undamped rotational tumbling. In contrast, ‘Oumuamua’s trajectory indicates that it was moving with the local stars, as expected from a low-velocity ejection from a relatively nearby system. Here, I assume that ‘Oumuamua is typical of 100 m interstellar objects and speculate on its origins. I find that giant planets are relatively inefficient at ejecting small bodies from inner solar systems of main-sequence stars, and that binary systems offer a much better opportunity for ejections of non-volatile bodies. I also conclude that ‘Oumuamua is not a member of a collisional population, which could explain its dramatic difference from small asteroids. I observe that 100 m small bodies are expected to carry little mass in realistic collisional populations and that occasional events, when whole planets are disrupted in catastrophic encounters, may dominate the interstellar population of 100 m fragments. Unlike the Sun or Jupiter, red dwarf stars are very dense and are capable of thoroughly tidally disrupting terrestrial planets. I conclude that ‘Oumuamua may have originated as a fragment from a planet that was tidally disrupted and then ejected by a dense member of a binary system, which could explain its peculiarities.
La Linière, l’impossible hospitalité en camp
Authors: Bouagga Yasmine
Published: January 2018

En mars 2016, s’ouvre à Grande-Synthe, près de Dunkerque, le « premier camp humanitaire aux normes internationales » en France, à l’initiative du maire de la commune et de Médecins sans frontières, avec pour objectif d’accueillir les migrants en transit vers la Grande-Bretagne qui croupissaient jusque-là dans un terrain marécageux. Mais comment et pourquoi ouvrir un tel camp dans un pays, censé être la 5 e puissance mondiale ?
À Paris, contrôle et expulsion en guise d’accueil
Authors: Macé Morgane
Published: January 2018

Novembre 2016 : un « centre humanitaire » ouvre ses portes dans le nord de Paris pour accueillir les exilé·e·s qui, faute de structures d’hébergement, dorment en nombre à la rue. Mais derrière la façade humanitaire, se cache un dispositif spécialement conçu par la préfecture de Paris pour éloigner au plus vite les exilé·e·s sans leur permettre de déposer une demande d’asile. Un piège administratif qui participe d’une politique d’expulsion ciblée facilitée par l’application du règlement « Dublin ».
Les relations école-famille sous l’angle de temporalités divergentes : suivi en « temps réel » ou médiation ?
Authors: Louessard Bastien , Levoin Xavier
Published: January 2018

Cette contribution propose d’examiner les pratiques d’un ENT (Environnement numérique de travail) par les différents membres de la communauté éducative sous l’angle de divergences entre les temporalités des uns et des autres. À partir d’entretiens menés avec des parents d’élèves, des chefs d’établissement, des CPE et des élèves de collèges et de lycées équipés d’un même ENT, les attentes et les craintes des acteurs révèlent la nature des discordances temporelles (débordement du temps professionnel sur le temps privé, affaiblissement de la médiation pédagogique, consumérisation de la relation éducative). Plusieurs observations conduisent cependant à nuancer cet écart et tendent à montrer que l’outil et ses contenus participent de la médiation entre école et famille.
Book Review: Jayadeva Uyangoda, Social Research: Philosophical and Methodological Foundations
Authors: Rambukwella Harshana
Published: January 2018

Jayadeva Uyangoda, Social Research: Philosophical and MethodologicalFoundations, Social Scientists’ Association, 2015, Pages: vii + 657, Price:LKR 1800, ISBN: 978-955-0762-33-0
Challenges in Cruise Tourism in Relation to Shore Excursions: The Case of Sri Lanka
Authors: Samarathunga W.H.M.S.
Published: January 2018

Although cruise tourism is one of the fastest growing segments of the international leisure tourism market, tourism research on ocean cruises have often been neglected in Sri Lanka. Cruise calls involve frequent shore excursions to attractions including both cultural and natural, in different parts of Sri Lanka. Thus, the aim of this study is to identify the challenges in cruise tourism in relation to shore excursions. The study is qualitative driven thus semi-structured interviews, discussions and participatory observation have been used as key research tools. Descriptive approaches were employed to analyze the data gathered. The findings emphasized that the shore excursion challenges are economic, natural and socio-cultural related, demand and supply related, and service providers related. The implications of the study can facilitate future researches, empirical studies, and strategy development relevant to cruise tourism.
Customer Relationship Management (CRM) Practices in the Hotel Sector from the Perspective of Leisure Travelers
Authors: Udunuwara Maduka , Sanders Dale , Wilkins Hugh
Published: January 2018

Customer relationship management (CRM) is widely discussed in numerous industries including the hotel sector. Much of the discussions on CRM have focused on implementations related aspects with only scant attention given to the CRM practices that manifest due to CRM implementations. As a result while the existing understanding on CRM has been established through an organisations point of view by identifying the back stage CRM from the point of view of the organisation, this study demonstrates the importance to enhance the understating of CRM through the customers’ point of view. Thus this study explored CRM practices experienced by the leisure travellers in the hotel context and what they think of such practices. Data was collected through focus groups which consisted of 22 participants in total. The findings indicated numerous customer relationship management practices experienced by leisure travellers at the: pre-encounter, encounter and post-encounter stages.
Illiquidity Based Factor Construction in Asset Pricing: An Analysis on Long Run Performance of Sri Lankan Initial Public Offering Stocks
Authors: Ediriwickrama T.C. , Azeez A.A.
Published: January 2018

IPO long run underperformance is a widely debated anomaly in corporate finance literature. Present study inquires whether above anomaly exists even after pricing for well known risk factors constructed based on size as well as illiquidity. This study proposed a new illiquidity based four factor asset pricing model and tested it using Sri Lankan initial public offering (IPO) stocks in inter war period and post war period. Proposed model was compared with Carhart (1997) four factor model. Both ordinary least square regression and weighted least square regression have been used to test Carhart’s model and proposed model in Sri Lankan context. It is found that long run IPO underperformance anomaly existed even after pricing for the illiquidity premium. Further two models perform very similarly and it is not fair to say one is superior to the other.
Is SAFTA Desirable? Evidence from Static Theory
Authors: Peiris T.U.I. , Azali M. , Habibullah M.S. , Hassan A.
Published: January 2018

South Asian Free Trade Area (SAFTA) depicts a huge potentiality in expanding intra-regional trade leading to a net trade creation for the region. Yet, prevailing inter-state political disputes and inner-state conflicts within the region tend to hinder intra-regional trade. Lack of prior studies that concentrate on these political factors when assessing the desirability of South Asian trade agreements motivates the present study. Thus, this study investigates the trade creation and trade diversion effects of SAFTA after controlling for political factors. In this regard, an augmented gravity model is employed over the period 2003 to 2013. Static linear panel estimation methods of pooled ordinary least square, random effects, and fixed effect methods are used in arriving at the results. Results confirm the desirability of SAFTA with the presence of significant intra-bloc and extra-bloc trade expansions. Further, SAFTA shows a significant anticipation effect as trade expansions are significant even prior to its implementation and they continued to be significant until 2012. Also, this study empirically confirms the deleteriousness of the region’s political factors in expanding trade.
Capital Structure Dynamics: Near vs. Off Target Firms in Sri Lanka
Authors: Buvanendra S.
Published: January 2018

This research paper aims at examining the determinants of the Speed of Adjustment (SOA) towards the target capital structure of near and off target firms in Sri Lanka. Particularly, it analyses the impact of not only firm-specific factors but also corporate governance factors on target capital structure. The methodology utilizes the benefits of the partial (stock) adjustment model, viz, two step Generalised Method of Moments (GMM) to determine the SOA to target capital structure. The results indicate that there is discernible concrete evidence of dynamic behaviour of capital structure in Sri Lanka. This confirms the applicability of dynamic trade-off theory. The near or off target firms’ capital structure adjustment exhibits significant difference in SOA between the two types, implying that off target firms adapt swiftly vis-à-vis those at the doorstep of target firms, in each of the three models. There is a clear indication of both firm related factors and corporate governance factors swaying capital structure adjustment in at least one of the measures of leverage in both situations, very near to and far off from optimum level of debt.