bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Development Process of a New Fluid–Solid Coupling Similar-Material Based on the Orthogonal Test
Authors: Liu Shiliang , Liu Weitao
Published: November 2018

Similar-material, composed of different raw materials with different properties, is similar to the physical and mechanical properties of geotechnical media, in which raw material proportioning is an important means to control the performance of similar-material in physical simulation. On this basis, a new fluid–solid coupling similar-material was developed through proportioning tests, in which similar-material is mixed with river sand, calcium carbonate, talc powder, white cement, vaseline, antiwear hydraulic oil. The optimum proportioning test development process was established. First, the proportioning test scheme was designed based on the orthogonal test. Subsequently, test specimens were produced to obtain parameters such as density, compressive strength, tensile strength, and permeability coefficient. Then, by increasing the ingredients of the proportioning, the evolution law of parameters was obtained by range and variance analysis. Finally, four multiple linear regression equations between the parameters and similar-material ingredients were obtained, and the optimum proportioning of ingredients was further determined for different requirements. The results indicate that the selected raw materials and their proportioning method are feasible, and the results were also verified in a coal mine floor water inrush by physical simulation test. The experimental development process of a fluid–solid coupling similar-material can provide a reference for similar-material under different demand conditions.
Enantioselective Extraction of Phenylalanine Enantiomers Using Environmentally Friendly Aqueous Two-Phase Systems
Authors: Sun Danyu , Wang Runping , Li Fenfang , Liu Lianglei , Tan Zhijian
Published: November 2018

(1) Background: The environmentally friendly choline-amino acid ionic liquids (ChAAILs) and deep eutectic solvents (DESs) have been used as excellent alternatives to volatile organic compounds (VOCs) and ionic liquids (ILs) in recent years; (2) Methods: Thus, ChAAILs/salt and DESs/salt aqueous two-phase systems (ATPSs) were developed for the chiral extraction of phenylalanine enantiomers. The optimum ATPS of [Ch][L-Pro]/K3PO4 was chosen, and the influencing parameters were investigated, including ChAAILs concentration, salt concentration, chiral selector concentration, extraction temperature, phenylalanine concentration, and system pH; (3) Results: The phenylalanine enantiomers were mainly extracted into the top phase (ChAAIL-rich phase), meanwhile, the (S)-phenylalanine [(S)-Phe)] was preferentially recognized by the chiral selector in the top phase. The maximum separation factor (α) of 2.05 was obtained under the optimal conditions; and (4) Conclusions: This ATPS that was used for the chiral extraction of enantiomers is much more environmentally friendly, simple, and rapid, and has the potential to be used in the enantioselective extraction of other enantiomers.
Tropical Deforestation and Recolonization by Exotic and Native Trees: Spatial Patterns of Tropical Forest Biomass, Functional Groups, and Species Counts and Links to Stand Age, Geoclimate, and Sustainability Goals
Authors: Helmer Eileen H. , Ruzycki Thomas S. , Wilson Barry T. , Sherrill Kirk R. , Lefsky Michael A. , Marcano-Vega Humfredo , Brandeis Thomas J. , Erickson Heather E. , Ruefenacht Bonnie
Published: November 2018

We mapped native, endemic, and introduced (i.e., exotic) tree species counts, relative basal areas of functional groups, species basal areas, and forest biomass from forest inventory data, satellite imagery, and environmental data for Puerto Rico and the Virgin Islands. Imagery included time series of Landsat composites and Moderate Resolution Imaging Spectroradiometer (MODIS)-based phenology. Environmental data included climate, land-cover, geology, topography, and road distances. Large-scale deforestation and subsequent forest regrowth are clear in the resulting maps decades after large-scale transition back to forest. Stand age, climate, geology, topography, road/urban locations, and protection are clearly influential. Unprotected forests on more accessible or arable lands are younger and have more introduced species and deciduous and nitrogen-fixing basal areas, fewer endemic species, and less biomass. Exotic species are widespread—except in the oldest, most remote forests on the least arable lands, where shade-tolerant exotics may persist. Although the maps have large uncertainty, their patterns of biomass, tree species diversity, and functional traits suggest that for a given geoclimate, forest age is a core proxy for forest biomass, species counts, nitrogen-fixing status, and leaf longevity. Geoclimate indicates hard-leaved species commonness. Until global wall-to-wall remote sensing data from specialized sensors are available, maps from multispectral image time series and other predictor data should help with running ecosystem models and as sustainable development indicators. Forest attribute models trained with a tree species ordination and mapped with nearest neighbor substitution (Phenological Gradient Nearest Neighbor method, PGNN) yielded larger correlation coefficients for observed vs. mapped tree species basal areas than Cubist regression tree models trained separately on each species. In contrast, Cubist regression tree models of forest structural and functional attributes yielded larger such correlation coefficients than the ordination-trained PGNN models.
Real-Time Prediction of Crop Yields From MODIS Relative Vegetation Health: A Continent-Wide Analysis of Africa
Authors: Petersen Lillian Kay
Published: November 2018

Developing countries often have poor monitoring and reporting of weather and crop health, leading to slow responses to droughts and food shortages. Here, I develop satellite analysis methods and software tools to predict crop yields two to four months before the harvest. This method measures relative vegetation health based on pixel-level monthly anomalies of NDVI, EVI and NDWI indices. Because no crop mask, tuning, or subnational ground truth data are required, this method can be applied to any location, crop, or climate, making it ideal for African countries with small fields and poor ground observations. Testing began in Illinois where there is reliable county-level crop data. Correlations were computed between corn, soybean, and sorghum yields and monthly vegetation health anomalies for every county and year. A multivariate regression using every index and month (up to 1600 values) produced a correlation of 0.86 with corn, 0.74 for soybeans, and 0.65 for sorghum, all with p-values less than 10 − 6 . The high correlations in Illinois show that this model has good forecasting skill for crop yields. Next, the method was applied to every country in Africa for each country’s main crops. Crop production was then predicted for the 2018 harvest and compared to actual production values. Twenty percent of the predictions had less than 2% error, and 40% had less than 5% error. This method is unique because of its simplicity and versatility: it shows that a single user on a laptop computer can produce reasonable real-time estimates of crop yields across an entire continent.
An EEG Experimental Study Evaluating the Performance of Texas Instruments ADS1299
Authors: Rashid Usman , Niazi Imran Khan , Signal Nada , Taylor Denise
Published: November 2018

Texas Instruments ADS1299 is an attractive choice for low cost electroencephalography (EEG) devices owing to its low power consumption and low input referred noise. To date, there have been no rigorous evaluations of its performance. In this EEG experimental study we evaluated the performance of the ADS1299 against a high quality laboratory-based system. Two self-paced lower limb motor tasks were performed by 22 healthy participants. Recorded power across delta, theta, alpha, and beta EEG bands, the power ratio across the motor tasks, pre-movement noise, and signal-to-noise ratio were obtained for evaluation. The amplitude and time of the negative peak in the movement-related cortical potentials (MRCPs) extracted from the EEG data were also obtained. Using linear mixed models, no statistically significant differences (p > 0.05) were found in any of these measures across the two systems. These findings were further supported by evaluation of cosine similarity, waveform differences, and topographic maps. There were statistically significant differences in MRCPs across the motor tasks in both systems. We conclude that the performance of the ADS1299 in combination with wet Ag/AgCl electrodes is analogous to that of a laboratory-based system in a low frequency (<40 Hz) EEG recording.
Feasibility of Distributed Fiber Optic Sensor for Corrosion Monitoring of Steel Bars in Reinforced Concrete
Authors: Fan Liang , Bao Yi , Chen Genda
Published: November 2018

This study investigates the feasibility of distributed fiber optic sensor for corrosion monitoring of steel bars embedded in concrete. Two sensor installation methods are compared: (1) attaching the sensor along the bar and (2) winding the sensor on the bar. For the second method, optical fibers were winded spirally on steel bars with different spacings: 0 mm, 2 mm, 5 mm, and 10 mm. Steel bar pull-out testing was conducted to evaluate the effect of presence of distributed sensor on the bond strength of steel–concrete interface. Electrochemical testing was carried out to assess the influence of the installation methods on the corrosion resistance of the reinforced concrete. Winding the optical fiber on steel bars with a 10-mm spacing does not affect the bond strength and corrosion resistance and allows real-time corrosion monitoring. The distributed sensor data can be used to estimate the corrosion induced steel loss and predict concrete cracking.
Implementation of a Piezo-diagnostics Approach for Damage Detection Based on PCA in a Linux-Based Embedded Platform
Authors: Camacho Jhonatan , Quintero Andrés , Ruiz Magda , Villamizar Rodolfo , Mujica Luis
Published: November 2018

The implementation of damage-detection methods for continuously assessing structural integrity entails systems with attractive features such as storage capabilities, memory capacity, computational complexity and time-consuming processing. In this sense, embedded hardware platforms are a promising technology for developing integrated solutions in Structural Health Monitoring. In this paper, design, test, and specifications for a standalone inspection prototype are presented, which take advantage of piezo-diagnostics principle, statistical processing via Principal Component Analysis (PCA) and embedded systems. The equipment corresponds to a piezoelectric active system with the capability to detect defects in structures, by using a PCA-based algorithm embedded in the Odroid-U3 ARM Linux platform. The operation of the equipment consists of applying, at one side of the structure, wide guided waves by means of piezoelectric devices operated in actuation mode and to record the wave response in another side of the structure by using the same kind of piezoelectric devices operated in sensor mode. Based on the nominal response of the guide wave (no damages), represented by means of a PCA statistical model, the system can detect damages between the actuated/sensed points through squared prediction error (Q-statistical index). The system performance was evaluated in a pipe test bench where two kinds of damages were studied: first, a mass is added to the pipe surface, and then leaks are provoked to the pipe structure by means of a drill tool. The experiments were conducted on two lab structures: (i) a meter carbon-steel pipe section and (ii) a pipe loop structure. The wave response was recorded between the instrumented points for two conditions: (i) The pipe in nominal conditions, where several repetitions will be applied to build the nominal statistical model and (ii) when damage is caused to the pipe (mass adding or leak). Damage conditions were graphically recognized through the Q-statistic chart. Thus, the feasibility to implement an automated real-time diagnostic system is demonstrated with minimum processing resources and hardware flexibility.
Large Occupational Accidents Data Analysis with a Coupled Unsupervised Algorithm: The S.O.M. K-Means Method. An Application to the Wood Industry
Authors: Comberti Lorenzo , Demichela Micaela , Baldissone Gabriele , Fois Gianmario , Luzzi Roberto
Published: November 2018

Data on occupational accidents are usually stored in large databases by worker compensation authorities, and by the safety and prevention teams of companies. An analysis of these databases can play an important role in the prevention of accidents and the reduction of risks, but it can be a complex procedure because of the dimensions and complexity of such databases. The SKM (SOM K-Means) method, a two-level clustering system, made up of SOM (Self Organizing Map) and K-Means clustering, has obtained positive results in identifying the dynamics of critical accidents by referring to a database of 1200 occupational accidents that had occurred in the wood industry. The present research has been conducted to validate the recently presented SKM methodology through the analysis of a larger data set of more than 4000 occupational accidents that occurred in Piedmont (Italy), between 2006 and 2013. This work has partitioned the accidents into groups of different accident dynamics families and has quantified the severity and frequency of occurrence of these accidents. The obtained information may be of help to Company Managers and National Authorities to better address preventive measures and policies concerning the clusters that have been identified as being the most critical within a risk-based decision-making framework.
Agricultural Education in Today’s School System: An Evaluation of Agricultural and Related Science Courses among High Schools in Alabama, USA
Authors: Jean Rosny , Christian Colmore
Published: November 2018

Previous studies on global food security have indicated that in order to sustain the global population by the year 2050, a significant increase in food production will be needed. Consequently, it is crucial that today’s students are educated to realize this increasing food demand. One of the problems is that currently too few students seem to be interested in pursuing studies in the fields of agriculture and related sciences. By exploring three research questions, this study assesses the extent to which high school students in each of the 67 counties in the U.S. state of Alabama are being exposed to agricultural-related science courses. For the purposes of this assessment, the high schools were grouped by zones—Northern, Central, Southern and the Black Belt. Relevant high school data, including courses offered, were compiled from Alabama’s Department of Education 2017 directory. Microsoft Excel and SPSS software were used to analyze the data. The findings of this study demonstrated that there are spatial differences in agriculture-related courses offered in high schools in Alabama’s Northern, Central and Southern regions. Future research should further investigate what percentage of high school students actually choose agriculture or related disciplines as their professional career paths after graduating from high school.
Determination of Optimum Hot-Water Temperatures for PCM Radiant Floor-Heating Systems Based on the Wet Construction Method
Authors: Baek Sanghoon , Kim Sangchul
Published: November 2018

Owing to use of mortar, which demonstrates low heat storage and discharge performance, conventional radiant floor-heating systems, based on the wet construction method and hot-water circulation, consume large amounts of energy. This study proposes a new type of radiant floor-heating system that is capable of reducing energy consumption via use of the latent heat of a phase change material (PCM), whereby the phase change, which occurs within, is induced by the thermal energy supplied by hot water. Simulation analyses revealed that hot-water supply temperatures, required to maintain the floor-surface and indoor-air temperatures at the set point using PCM latent heat, were in the range 40–41 °C. At supply water temperatures measuring less than 39 °C or exceeding 42 °C, the latent-heat effect of the phase change of the PCM tended to fail, and the corresponding floor-surface temperature assumed a value different from that corresponding to the set point. By contrast, supply temperatures in the range 40–41 °C resulted in return temperatures measuring approximately 27.4–27.5 °C, which in turn corresponded to an indoor air temperature of 21.6–22.6 °C that was stably maintained within ±0.6 °C of the 22 °C set-point temperature.
Trust at a Distance—Trust in Online Communication in Environmental and Global Health Research Projects
Authors: De Vries Jasper R. , Van Bommel Séverine , Peters Karin
Published: November 2018

Online collaboration to deal with (global) environmental and public health problems continues to grow as the quality of technology for communication improves. In these collaborations, trust is seen as important for sustainable collaborations and organizations. However, face-to-face communication, which is often lacking in these contexts, is seen as a pre-requisite for trust development. Therefore, this paper aims to explore empirically which factors influence the emergence of trust in the early stages of online collaboration. Using the relevant literature, we conducted a series of interviews around projects in the field of public health and the environment on the interface between science and practice. The results show that trust does develop between participants. This trust is strongly influenced by perceived ability and integrity, fostered by reputation, third-party perceptions, and project structure. In these contexts, these types of trust facilitate collaboration but are also influenced by a wider set of aspects such as power, expectations, and uncertainty. However, from the results we also conclude that online collaboration does not create benevolence and a shared identity, thereby limiting further trust development and leading to less strong relations. Strong relations, however, are deemed important to reach creative and innovative solutions and long-term sustainable collaboration and organizations.
Charged and Non-Charged Black Hole Solutions in Mimetic Gravitational Theory
Authors: Nashed Gamal G.L.
Published: November 2018

In this study, we derive, in the framework of mimetic theory, charged and non-charged black hole solutions for spherically symmetric as well as flat horizon spacetimes. The asymptotic behavior of those black holes behave as flat or (A)dS spacetimes and coincide with the solutions derived before in general relativity theory. Using the field equations of non-linear electrodynamics mimetic theory we derive new black hole solutions with monopole and quadrupole terms. The quadruple term of those black holes is related by a constant so that its vanishing makes the solutions coincide with the linear Maxwell black holes. We study the singularities of those solutions and show that they possess stronger singularity than the ones known in general relativity. Among many things, we study the horizons as well as the heat capacity to see if the black holes derived in this study have thermodynamical stability or not.
Local and Holistic Feature Fusion for Occlusion-Robust 3D Ear Recognition
Authors: Zhu Qinping , Mu Zhichun
Published: November 2018

Occlusion over ear surfaces results in performance degradation of ear registration and recognition systems. In this paper, we propose an occlusion-resistant three-dimensional (3D) ear recognition system consisting of four primary components: (1) an ear detection component, (2) a local feature extraction and matching component, (3) a holistic matching component, and (4) a decision-level fusion algorithm. The ear detection component is implemented based on faster region-based convolutional neural networks. In the local feature extraction and matching component, a symmetric space-centered 3D shape descriptor based on the surface patch histogram of indexed shapes (SPHIS) is used to generate a set of keypoints and a feature vector for each keypoint. Then, a two-step noncooperative game theory (NGT)-based method is proposed. The proposed symmetric game-based method is effectively applied to determine a set of keypoints that satisfy the rigid constraints from initial keypoint correspondences. In the holistic matching component, a proposed variant of breed surface voxelization is used to calculate the holistic registration error. Finally, the decision-level fusion algorithm is applied to generate the final match scores. Evaluation results from experiments conducted show that the proposed method produces competitive results for partial occlusion on a dataset consisting of natural and random occlusion.
Exactly Solvable One-Qubit Driving Fields Generated via Nonlinear Equations
Authors: Enríquez Marco , Cruz y Cruz Sara
Published: November 2018

Using the Hubbard representation for S U ( 2 ) , we write the time-evolution operator of a two-level system in the disentangled form. This allows us to map the corresponding dynamical law into a set of nonlinear coupled equations. In order to find exact solutions, we use an inverse approach and find families of time-dependent Hamiltonians whose off-diagonal elements are connected with the Ermakov equation. A physical model with the so-obtained Hamiltonians is discussed in the context of the nuclear magnetic resonance phenomenon.
MPF Problem over Modified Medial Semigroup Is NP-Complete
Authors: Sakalauskas Eligijus , Mihalkovich Aleksejus
Published: November 2018

This paper is a continuation of our previous publication of enhanced matrix power function (MPF) as a conjectured one-way function. We are considering a problem introduced in our previous paper and prove that tis problem is NP-Complete. The proof is based on the dual interpretation of well known multivariate quadratic (MQ) problem defined over the binary field as a system of MQ equations, and as a general satisfiability (GSAT) problem. Due to this interpretation the necessary constraints to MPF function for cryptographic protocols construction can be added to initial GSAT problem. Then it is proved that obtained GSAT problem is NP-Complete using Schaefer dichotomy theorem. Referencing to this result, GSAT problem by polynomial-time reduction is reduced to the sub-problem of enhanced MPF, hence the latter is NP-Complete as well.
Architecting and Designing Sustainable Smart City Services in a Living Lab Environment
Authors: Alam Md Tawseef , Porras Jari
Published: November 2018

In terms of sustainability, cities become smart when they provide smart services to the inhabitants using information and communication technologies without threatening the future of the environment, economy, or society. However, the process of developing such sustainable smart services has certain challenges, especially in understanding the real needs of the people living in the city. Citizens or, in a wider perspective, the inhabitants of the city are the key stakeholders in the case of smart services in a city. Active involvement of the people throughout the development process is a way of successfully designing such services. On the other hand, integrating sustainability, for example, including environmental data, into smart city services is challenging. Therefore, this research aims to combine environmental data with regular smart city services, while engaging city inhabitants in the development process. This approach was adapted from the concept of living lab methodology. Finally, an application developed following this method is presented and evaluated.
CRISPRStudio: A User-Friendly Software for Rapid CRISPR Array Visualization
Authors: Dion Moïra B. , Labrie Simon J. , Shah Shiraz A. , Moineau Sylvain
Published: November 2018

The CRISPR-Cas system biologically serves as an adaptive defense mechanism against phages. However, there is growing interest in exploiting the hypervariable nature of the CRISPR locus, often of viral origin, for microbial typing and tracking. Moreover, the spacer content of any given strain provides a phage resistance profile. Large-scale CRISPR typing studies require an efficient method for showcasing CRISPR array similarities across multiple isolates. Historically, CRISPR arrays found in microbes have been represented by colored shapes based on nucleotide sequence identity and, while this approach is now routinely used, only scarce computational resources are available to automate the process, making it very time-consuming for large datasets. To alleviate this tedious task, we introduce CRISPRStudio, a command-line tool developed to accelerate CRISPR analysis and standardize the preparation of CRISPR array figures. It first compares nucleotide spacer sequences present in a dataset and then clusters them based on sequence similarity to assign a meaningful representative color. CRISPRStudio offers versatility to suit different biological contexts by including options such as automatic sorting of CRISPR loci and highlighting of shared spacers, while remaining fast and user-friendly.
Comprehensive Analysis of Hepatitis B Virus Promoter Region Mutations
Authors: Meier-Stephenson Vanessa , Bremner William T. R. , Dalton Chimone S. , Van Marle Guido , Coffin Carla S. , Patel Trushar R.
Published: November 2018

Over 250 million people are infected chronically with hepatitis B virus (HBV), the leading cause of liver cancer worldwide. HBV persists, due, in part, to its compact, stable minichromosome, the covalently-closed, circular DNA (cccDNA), which resides in the hepatocytes’ nuclei. Current therapies target downstream replication products, however, a true virological cure will require targeting the cccDNA. Finding targets on such a small, compact genome is challenging. For HBV, to remain replication-competent, it needs to maintain nucleotide fidelity in key regions, such as the promoter regions, to ensure that it can continue to utilize the necessary host proteins. HBVdb (HBV database) is a repository of HBV sequences spanning all genotypes (A–H) amplified from clinical samples, and hence implying an extensive collection of replication-competent viruses. Here, we analyzed the HBV sequences from HBVdb using bioinformatics tools to comprehensively assess the HBV core and X promoter regions amongst the nearly 70,000 HBV sequences for highly-conserved nucleotides and variant frequencies. Notably, there is a high degree of nucleotide conservation within specific segments of these promoter regions highlighting their importance in potential host protein-viral interactions and thus the virus’ viability. Such findings may have key implications for designing antivirals to target these areas.
Measuring Inundation Depth in a Subway Station Using the Laser Image Analysis Method
Authors: Park Inhwan , Seong Hoje , Ryu Yonguk , Rhee Dong Sop
Published: November 2018

Subway station platforms are vulnerable to flood damage. Thus, investigation of inundation properties in subway platforms is required to ensure the safety of citizens against flooding. In this study, the evacuation time and safety were analyzed in a subway station model using inundation depth measurements. The subway station model contained shallow water depth conditions, which did not allow for contact-type measurement devices. Instead, an image analysis procedure using laser images was proposed to measure the inundation depth. The proposed laser image analysis method can recognize a boundary line between the water and air by visualizing the water surface using a laser sheet. The inundation depth measurements using the image analysis method were reasonably accurate, resulting in differences of 2.97–7.67% compared to the results obtained using a digital point gauge. When inflow positions and flowrates of rainwater were changed, the measured results showed that the inundation depth increased in areas in which the rainwater inflow was relatively small or collided when moving in the direction opposite to the rainwater. The calculated evacuation time from the subway station showed that a drainage system is required to decrease the inundation depth in areas of inflowing rainwater collision. Furthermore, the estimated results of evacuation safety showed that safety handles are necessary even in low depth regions to prevent people from falling down due to increased flow velocity, during evacuation.
ALMA Reveals a Collision between Protostellar Outflows in BHR 71
Authors: Zapata Luis A. , Fernández-López Manuel , Rodríguez Luis F. , Garay Guido , Takahashi Satoko , Lee Chin-Fei , Hernández-Gómez Antonio
Published: November 2018

For a binary protostellar outflow system in which its members are located close to each other (the separation being smaller than the addition of the widths of the flows) and with large opening angles, the collision seems unavoidable regardless of the orientation of the outflows. This is in contrast to the current observational evidence of just a few regions with indications of colliding outflows, which could also suggests that the average distance between protostars is larger than the width of the flows. Here, using sensitive observations of the Atacama Large Millimeter/Submillimeter Array, we report resolved images of carbon monoxide (CO) toward the binary flows associated with the BHR 71 protostellar system. These images reveal for the first time solid evidence that their flows are partially colliding, increasing the brightness of the CO, the dispersion of the velocities in the interaction zone, and changing part of the orientation in one of the flows. Additionally, this impact opened the possibility of knowing the three-dimensional geometry of the system, revealing that one of its components (IRS 2) should be closer to us.
Hubble Space Telescope Observations of 3200 Phaethon at Closest Approach
Authors: Jewitt David , Mutchler Max , Agarwal Jessica , Li Jing
Published: November 2018

We present Hubble Space Telescope observations of the active asteroid (and Geminid stream parent) 3200 Phaethon when at its closest approach to Earth (separation 0.07 au) in 2017 December. Images were recorded within ∼1° of the orbital plane, providing extra sensitivity to low surface brightness caused by scattering from a large-particle trail. We placed an upper limit on the apparent surface brightness of such a trail at 27.2 mag arcsecond−2, corresponding to an in-plane optical depth ≤3 × 10−9. No co-moving sources brighter than absolute magnitude 26.3, corresponding to circular equivalent radius ∼12 m (albedo 0.12 assumed), were detected. Phaethon is too hot for near-surface ice to survive. We briefly consider the thermodynamic stability of deeply buried ice, finding that its survival would require either a very small (regolith-like) thermal diffusivity (<10−8 m2 s−1), or the unexpectedly recent injection of Phaethon (timescale ≲106 years) into its present orbit, or both.
The Stellar Contents of Intermediate-mass Disk Galaxies in the Virgo Cluster. I. GMOS Spectra*
†
‡
Authors: Davidge T. J.
Published: November 2018

The stellar contents of six intermediate-mass early-type disk galaxies in the Virgo cluster are examined using deep long slit spectra. The isophotal and photometric properties of the galaxies at near- and mid-infrared wavelengths are also examined. Characteristic ages and metallicities are found by making comparisons with the strengths of lines measured from model spectra. The light from the central regions of these galaxies at visible/red wavelengths is not dominated by old populations. Rather, the central regions of four galaxies (NGC 4305, NGC 4306, NGC 4497, and NGC 4620) are dominated by populations with ages ∼1.5–3 Gyr. Centrally concentrated line emission is found in two of the galaxies (NGC 4491 and NGC 4584), and the relative strengths of Hα and [S ii]6746 are consistent with this emission originating in star-forming regions. The disks of these galaxies are dominated by populations that are at least 1 Gyr older than those near the centers, indicating that the quenching of star formation progressed from large radii inwards, and did not occur over a short timescale. NGC 4497 has the oldest disk, with a luminosity-weighted age of 10 Gyr. The metallicities of the galaxies in this sample are consistent with their integrated brightnesses, suggesting that they have not been subjected to large-scale stellar stripping. [Mg/Fe] is roughly solar, suggesting that these systems retained and enriched gas over timescales of at least 1 Gyr. The progenitors of these galaxies were likely late-type systems that were accreted by Virgo during intermediate or early epochs and have since been depleted of gas and dust.
Compton Shoulder Diagnostics in Active Galactic Nuclei for Probing the Metallicity of the Obscuring Compton-thick Tori
Authors: Hikitani Masaya , Ohno Masanori , Fukazawa Yasushi , Kawaguchi Toshihiro , Odaka Hirokazu
Published: November 2018

We analyzed the spectral shape of the Compton shoulder around the neutral Fe–K
α
line of the Compton-thick type II Seyfert nucleus of the Circinus galaxy. The characteristics of this Compton shoulder with respect to the reflected continuum and Fe–K
α
line core intensity are powerful diagnostics tools for analyzing the structure of the molecular tori, which obscures the central engine. We applied our Monte-Carlo-based X-ray reflection spectral model to the Chandra High Energy Transmission Grating data and successfully constrained the various spectral parameters independently, using only the spectral data only around the Fe–K
α
emission line. The obtained column density and inclination angle are consistent with previous observations and the Compton-thick type II Seyfert picture. In addition, we determined the metal abundance of the molecular torus for the case of the smooth and clumpy torus to be

and 1.74 ± 0.16 solar abundance, respectively. Such slightly over-solar abundance can be useful information for discussing the star formation rate in the molecular tori of active galactic nuclei.
Hyperflares of M Dwarfs
Authors: Chang H.-Y. , Lin C.-L. , Ip W.-H. , Huang L.-C. , Hou W.-C. , Yu P.-C. , Song Y.-H. , Luo A.
Published: November 2018

From a study of the light curves of the M dwarfs observed by the Kepler space telescope in its primary mission, a number of flare events with the peak flux increases reaching more than the nominal stellar luminosity have been found. One of them, KIC 9201463, produced an extreme flare with the peak flux increase jumping to five times the quiet-time value. In relative terms, this class of hyperflares is much stronger than the superflares of the solar-type stars and could have a very important influence on the atmospheric evolution and the potential development of biospheres of habitable super-Earths orbiting around M dwarf stars. A cross-correlation of the flare activities of some of these M dwarf stars and their Hα equivalent width (EW) values derived from the LAMOST project indicates that the Hα EW values can be used to monitor the occurrence of hyperflares as well as the level of flare activity of different classes of M dwarfs with fast to slow rotations, and hence the long-term environmental effects of star–planet interaction of exoplanets.
Forming Gliese 876 through Smooth Disk Migration
Authors: Dempsey Adam M. , Nelson Benjamin E.
Published: November 2018

We run a suite of dissipative N-body simulations to determine which regions of phase space for smooth disk migration are consistent with the GJ876 system, an M-dwarf hosting three planets orbiting in a chaotic 4:2:1 Laplace resonance. We adopt adaptive mesh refinement (AMR) methods that are commonly used in hydrodynamical simulations to efficiently explore the parameter space defined by the semimajor axis and eccentricity damping timescales. We find that there is a large region of phase space that produces systems in the chaotic Laplace resonance and a smaller region consistent with the observed eccentricities and libration amplitudes for the resonant angles. Under the assumptions of Type I migration for the outer planet, we translate these damping timescales into constraints on the protoplanetary disk surface density and thickness. When we strongly (weakly) damp the eccentricities of the inner two Laplace planets, these timescales correspond to disk surface densities around ten thousand (a few hundred) grams per square centimeter and disk aspect ratios between 1% and 10%. Additionally, smooth migration produces systems with a range of chaotic timescales, from decades and centuries to upward of thousands of years. In agreement with previous studies, the less chaotic regions of phase space coincide with the system being in a low-energy double apsidal corotation resonance. Our detailed modeling of multiplanetary systems coupled with our AMR exploration method enhances our ability to map out the parameter space of planet formation models and is well suited to study other resonant chain systems such as Trappist-1, Kepler-60, and others.
Description of three new species of Scolanthus (Cnidaria, Anthozoa, Actiniaria, Edwardsiidae): first records of the genus from Japan
Authors: Izumi Takato , Fujita Toshihiko
Published: November 2018

Scolanthusis one genus of Edwardsiidae, a speciose family of burrowing worm-like sea anemones characterized by lacking a physa-like aboral end and by possessing nemathybomes on the whole body except at the distal end. This genus has been recorded worldwide, but there have been no specimens collected from Japan. In this study, we discovered fourScolanthusspecies in Japan for the first time:Scolanthusarmatus(Carlgren, 1931) andScolanthuskopepesp. n.from the Ogasawara Islands,Scolanthusenasp. n.from Ena Bay, Kanagawa, andScolanthusiseisp. n.from Sugashima Island, Mie.
Review of Brazilian jawfishes of the genus Opistognathus with descriptions of two new species (Teleostei, Opistognathidae)
Authors: Smith-Vaniz William F. , Tornabene Luke , Macieira Raphael M.
Published: November 2018

A new species of jawfish,Opistognathusthionyisp. n., is described from the Vitória-Trindade Chain and Fernando de Noronha Archipelago off Brazil, a disjunct distribution of ca. 1,800 km.Opistognathusthionyiand its allopatric Caribbean sister-species,Opistognathusmaxillosus, both have a wide, fan-like upper margin of the subopercular flap and mostly over-lapping meristic data. The new species differs fromO.maxillosusin having the darkest spot on the spinous dorsal fin, when present, between spines 2–5, versus always present between spines 6–9, the buccal area surrounding the esophageal opening pale versus very dark and fewer oblique scale rows in longitudinal series (45–52 vs. 69–85). A second new species,Opistognathusvicinussp. n., known from Brazil’s mainland, has completely over-lapping meristic values with its allopatric Caribbean sister-speciesO.whitehursti, but differs in lacking vomerine teeth and a supramaxilla and retaining the juvenile color pattern of the latter species in adults. Diagnoses, photographs, an identification key, and distributional maps are given for all Brazilian species ofOpistognathus.

Molecular phylogenetic analysis of partial cytochrome c oxidase subunit-I sequences indicates that specimens of the two allopatric pairs,O.thionyi–O.maxillosusandO.vicinus–O.whitehursti, form reciprocally monophyletic groups that differ from each other on average by 9 to 11%, with less than 1% average pair-wise genetic distance within-species. Similar patterns of phylogenetic structure were observed between reciprocally monophyletic (predominately allopatric) groups within nominal species ofOpistognathusaurifrons, suggesting the possibility of at least two additional undescribed species from the Brazilian Province.
A new genus of oonopid spiders from Myanmar (Araneae, Oonopidae)
Authors: Tong Yanfeng , Chen Haifeng , Liu Sijia , Li Shuqiang
Published: November 2018

A new genus,KachiniaTong & Li,gen. n., including two new species,K.putaoTong & Li,sp. n., andK.mahmolaeTong & Li,sp. n., is described from Myanmar. The new genus belonging to the subfamily Oonopinae Simon, 1890, currently is the only member of theBrignolia-Opopaeaclade with leg spines.
Revision of Lineostethus (Heteroptera: Pentatomidae: Discocephalini)
Authors: de Almeida Garbelotto Thereza , Leite Kochenborger Ana Paula , Campos Luiz Alexandre
Published: November 2018

LineostethusRuckes, 1966 has four species,L.clypeatus(Stål, 1862),L.graziaeHildebrand & Becker, 1982,L.marginellus(Stål, 1872), andL.tenebricornis(Ruckes, 1957); mostly restricted to Central America, but with distribution records in the southern North America.Lineostethusis one of the discocephaline genera with discoid head. The last review of the genus, from the 1980’s, focused on the genital morphology and failed to provide updated descriptions or a key to species. We had access to material from different collections, including several specimens representing new species ofLineostethus, and males ofL.marginelluswhich shows important variations in genital morphology. Here we update the generic description ofLineostethusand its known species and describe the new speciesLineostethusacuminatussp. nov. (holotype male in DZUP: Costa Rica, Guanacaste),Lineostethusauritussp. nov. (holotype male in AMNH: Mexico, Oaxaca),Lineostethusotarussp. nov. (holotype male in AMNH: Mexico, Michoacán) andLineostethussinuosussp. nov. (holotype male in DZUP: Mexico, Yucatán). Additionally, we provide identification keys and distribution maps.
Morphological study of the gastrointestinal tract of Larimichthys crocea (Acanthopterygii: Perciformes)
Authors: Kalhoro Hameeda , Tong Shengli , Wang Lei , Hua Ying , Volatiana Josie Ancella , Shao Qingjun
Published: November 2018

The present study aimed to investigate the macroscopic and histological structure of the gastrointestinal tract (GIT) of Larimichthyscrocea (Richardson, 1846). It consists of esophagus, stomach regions, pyloric caeca, intestinal regions, and rectum. Sixteen tubular light yellowish pyloric caeca of similar sizes were observed in all individuals. The digestive wall consists of mucosa, submucosa, muscularis, and adventitia. No major differences appeared in the structure of the tunica, epithelial cell types, connective tissues and musculature glands of L.crocea GIT. The mucosal epithelia in the oesophagus has longitudinal branched folds with frontward and hindmost zones. The gastric tunica mucosa has a characteristic folded structure and can be divided into three regions. The intestinal tunica mucosa is characterized by villi structures and numerous mucus-secreting cells. Mucus-secreting goblet cells were strongly positive to AB at pH 2.5 in the oesophagus (excluding gastro-oesophageal junction) and intestine mucosal regions, which indicates an abundance of carboxylate mucins. The surface epithelia of the gastric mucosa is PAS-positive and AB-negative. SEM examination revealed that cells in the epithelium of the esophagus have an unbroken apical layer and goblet cells. The intestinal coefficient (IC) of L.crocea was 0.80 ± 0.21, consistent with a carnivorous or omnivorous habit. Our study adds the knowledge of the digestive system of L.crocea and might be useful in the management of L.crocea stocks.
High Incidence of Arterial and Venous Thrombosis in Antineutrophil Cytoplasmic Antibody–associated Vasculitis
Authors: Kang Amy , Antonelou Marilina , Wong Nikki L. , Tanna Anisha , Arulkumaran Nishkantha , Tam Frederick W.K. , Pusey Charles D.
Published: November 2018

Objective.

To determine the incidence of arterial thrombotic events (ATE) and venous thromboembolism (VTE) in antineutrophil cytoplasmic antibody–associated vasculitis (AAV).

Methods.

This is a retrospective cohort study presenting the incidence of ATE (coronary events or ischemic stroke) and VTE [pulmonary embolism (PE) or deep venous thrombosis (DVT)] in patients diagnosed with AAV between 2005 and 2014.

Results.

There were 204 patients with AAV who were identified. Median followup for surviving patients was 5.8 (range 1–10) years, accounting for 1088 person-years (PY). The incidence of ATE was 2.67/100 PY (1.56 for coronary events and 1.10 for ischemic stroke) and for VTE was 1.47/100 PY (0.83 for DVT only and 0.64 for PE with/without DVT). On multivariate analysis, prior ischemic heart disease (IHD) and advancing age were the only independent predictors of ATE. Among patients without prior IHD or stroke, the incidence of ATE remained elevated at 2.32/100 PY (1.26 for coronary events and 1.06 for ischemic stroke). ATE, but not VTE, was an independent predictor of all-cause mortality. Event rates for both ATE and VTE were highest in the first year after diagnosis of AAV but remained above the population incidence during the 10-year followup period. In comparison to reported rates for the UK population, the event rates in our AAV patients were 15-times higher for coronary events, 11-times higher for incident stroke, and 20-times higher for VTE.

Conclusion.

Patients with AAV have a high incidence of arterial and venous thrombosis, particularly in the first year after diagnosis.
Ultrasound of Subtalar Joint Synovitis in Patients with Rheumatoid Arthritis: Results of an OMERACT Reliability Exercise Using Consensual Definitions
Authors: Bruyn George A.W. , Siddle Heidi J. , Hanova Petra , Costantino Félicie , Iagnocco Annamaria , Sedie Andrea Delle , Gutierrez Marwin , Hammer Hilde B. , Jernberg Elizabeth , Loeille Damien , Micu Mihaela C. , Moller Ingrid , Pineda Carlos , Richards Bethan , Stoenoiu Maria S. , Suzuki Takeshi , Terslev Lene , Vlad Violeta , Wonink Robert , d’Agostino Maria-Antonietta , Wakefield Richard J.
Published: November 2018

Objective.

To evaluate the intraobserver and interobserver reliability of the ultrasonographic (US) assessment of subtalar joint (STJ) synovitis in patients with rheumatoid arthritis (RA).

Methods.

Following a Delphi process, 12 sonographers conducted an US reliability exercise on 10 RA patients with hindfoot pain. The anteromedial, posteromedial, and posterolateral STJ was assessed using B-mode and power Doppler (PD) techniques according to an agreed US protocol and using a 4-grade semiquantitative grading score for synovitis [synovial hypertrophy (SH) and signal] and a dichotomous score for the presence of joint effusion (JE). Intraobserver and interobserver reliability were computed by Cohen’s and Light’s κ. Weighted κ coefficients with absolute weighting were computed for B-mode and PD signal.

Results.

Mean weighted Cohen’s κ for SH, PD, and JE were 0.80 (95% CI 0.62–0.98), 0.61 (95% CI 0.48–0.73), and 0.52 (95% CI 0.36–0.67), respectively. Weighted Cohen’s κ for SH, PD, and JE in the anteromedial, posteromedial, and posterolateral STJ were −0.04 to 0.79, 0.42–0.95, and 0.28–0.77; 0.31–1, −0.05 to 0.65, and −0.2 to 0.69; 0.66–1, 0.52–1, and 0.42–0.88, respectively. Weighted Light’s κ for SH was 0.67 (95% CI 0.58–0.74), 0.46 (95% CI 0.35–0.59) for PD, and 0.16 (95% CI 0.08–0.27) for JE. Weighted Light’s κ for SH, PD, and JE were 0.63 (95% CI 0.45–0.82), 0.33 (95% CI 0.19–0.42), and 0.09 (95% CI −0.01 to 0.19), for the anteromedial; 0.49 (95% CI 0.27–0.64), 0.35 (95% CI 0.27–0.4), and 0.04 (95% CI −0.06 to 0.1) for posteromedial; and 0.82 (95% CI 0.75–0.89), 0.66 (95% CI 0.56–0.8), and 0.18 (95% CI 0.04–0.34) for posterolateral STJ, respectively.

Conclusion.

Using a multisite assessment, US appears to be a reliable tool for assessing synovitis of STJ in RA.