bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimized High Resolution 3D Dense-U-Net Network for Brain and Spine Segmentation
Authors: Kolařík Martin , Burget Radim , Uher Václav , Říha Kamil , Dutta Malay Kishore
Published: January 2019

The 3D image segmentation is the process of partitioning a digital 3D volumes into multiple segments. This paper presents a fully automatic method for high resolution 3D volumetric segmentation of medical image data using modern supervised deep learning approach. We introduce 3D Dense-U-Net neural network architecture implementing densely connected layers. It has been optimized for graphic process unit accelerated high resolution image processing on currently available hardware (Nvidia GTX 1080ti). The method has been evaluated on MRI brain 3D volumetric dataset and CT thoracic scan dataset for spine segmentation. In contrast with many previous methods, our approach is capable of precise segmentation of the input image data in the original resolution, without any pre-processing of the input image. It can process image data in 3D and has achieved accuracy of 99.72% on MRI brain dataset, which outperformed results achieved by human expert. On lumbar and thoracic vertebrae CT dataset it has achieved the accuracy of 99.80%. The architecture proposed in this paper can also be easily applied to any task already using U-Net network as a segmentation algorithm to enhance its results. Complete source code was released online under open-source license.
2018 IEEE International Work Conference on Bioinspired Intelligence (IWOBI): Conference Report
Authors: Crespo-Mariño Juan Luis
Published: January 2019

The International Work Conference on Bioinspired Intelligence (IWOBI) is an annual event that comprises both an international peer-reviewed scientific conference and a set of workshops and other activities in order to foster the research abilities and expertise of young researchers in the field of bioinspired intelligence. IWOBI 2018 has been characterized by a strong transdisciplinary component. The main conference themes were at the intersection between classical engineering disciplines and computer science, and the life and health sciences. This was motivated by the scientific environment that defines research that is being conducted in Costa Rica. Even though IWOBI is an international event, it was very important for the local organizing committee to focus on knowledge areas that were considered of special interest to Costa Rican researchers and to students looking to start their scientific careers. With such great expectations, IWOBI 2018 has been the first IWOBI conference in history to have parallel tracks. In addition to a regular track, a biocomputation and related techniques track was developed, as well as another one devoted to high-performance computing (HPC) systems applications for life and health sciences applications. Workshops were another important resource developed within IWOBI 2018. They were considered a very important tool in order to foster and train young researchers within the country and they are a very valuable chance to establish direct networking with elite researchers from different countries and research interests. IWOBI 2018 was the first IWOBI conference that implemented real and effective workshops. There were two workshops, one of them devoted to COPASI software and the other one focused on the use of the message passing interface (MPI) parallel programming library.
Integral Representations and Algebraic Decompositions of the Fox-Wright Type of Special Functions
Authors: Prodanov Dimiter
Published: January 2019

The manuscript surveys the special functions of the Fox-Wright type. These functions are generalizations of the hypergeometric functions. Notable representatives of the type are the Mittag-Leffler functions and the Wright function. The integral representations of such functions are given and the conditions under which these function can be represented by simpler functions are demonstrated. The connection with generalized Erdélyi-Kober fractional differential and integral operators is demonstrated and discussed.
The Misconception of Antibiotic Equal to an Anti-Inflammatory Drug Promoting Antibiotic Misuse among Chinese University Students
Authors: Wang Weiyi , Wang Xiaomin , Hu Yanhong Jessika , Wu Dan , Lu Jingjing , Xu Yannan , Sun Chenhui , Zhou Xudong
Published: January 2019

Massive misuse of antibiotics is one of the most important reasons for antimicrobial resistance (AMR). Misconceptions of antibiotics contribute to antibiotic misuse behaviors. This study aims to examine whether university students hold the misconception that Antibiotic is a Xiaoyanyao (literally means anti-inflammatory drug in Chinese), and association between this misconception and antibiotic misuse behaviors. A cross-sectional study was conducted among university students using the cluster random sampling method in six universities of six regions in China (one university per region). The Chi-square test was used to assess the relationship between the misconception and antibiotic misuse behaviors. Logistic regression was conducted to identify the risk factors for antibiotic misuse behaviors. 11,192 of university students completed the entire questionnaire. There were 3882 (34.7%) students who were considered to have the misconception. Female students were more likely to have the misconception compared with males (36.7% vs. 32.6%, P < 0.001). Those students with a background of social science/humanities were more likely to have the misconception compared with those from science and medicine (44.1% vs. 30.3% vs. 20.1%, P < 0.001). Students came from rural areas compared with those from urban areas (37.5% vs. 32.5%, P < 0.001) were more likely to have the misconception. Students who had the misconception were 1.51 (95% CI 1.21–1.89, P < 0.001) times, 1.34 (95% CI 1.21–1.48, P < 0.001) times, and 1.36 (95% CI 1.24–1.50, P < 0.001) times more likely to report self-medication, request to obtain antibiotics, and take antibiotics prophylactically than those who did not have this misconception, respectively. The high proportion of university students’ misconception on Antibiotic is a Xiaoyanyao is worth more attention. Effective health education and interventions need to be promoted among university students and the whole population.
Uniaxial Tensile Behavior of Carbon Textile Reinforced Mortar
Authors: Zhou Fen , Liu Huanhui , Du Yunxing , Liu Lingling , Zhu Deju , Pan Wei
Published: January 2019

This paper investigates the effects of the reinforcement ratio, volume fraction of steel fibers, and prestressing on the uniaxial tensile behavior of carbon textile reinforced mortar (CTRM) through uniaxial tensile tests. The results show that the tensile strength of CTRM specimens increases with the reinforcement ratio, however the textile–matrix bond strength becomes weaker and debonding can occur. Short steel fibers are able to improve the mechanical properties of the entire CTRM composite and provide additional “shear resistant ability” to enhance the textile– matrix bond strength, resulting in finer cracks with smaller spacing and width. Investigations into the fracture surfaces using an optical microscope clarify these inferences. Increases in first-crack stress and tensile strength are also observed in prestressed TRM specimens. In this study, the combination of 1% steel fibers and prestressing at 15% of the ultimate tensile strength of two-layer textiles is found to be the optimum configuration, producing the highest first-crack stress and tensile strength and the most reasonable multi-cracking pattern.
Particulated, Extracted Human Teeth Characterization by SEM–EDX Evaluation as a Biomaterial for Socket Preservation: An In Vitro Study
Authors: Calvo-Guirado José Luis , Ballester Montilla Alvaro , De Aza Piedad N , Fernández-Domínguez Manuel , Gehrke Sergio Alexandre , Cegarra-Del Pino Pilar , Mahesh Lanka , Pelegrine André Antonio , Aragoneses Juan Manuel , Maté-Sánchez de Val José Eduardo
Published: January 2019

The aim of the study was to evaluate the chemical composition of crushed, extracted human teeth and the quantity of biomaterial that can be obtained from this process. A total of 100 human teeth, extracted due to trauma, decay, or periodontal disease, were analyzed. After extraction, all the teeth were classified, measured, and weighed on a microscale. The human teeth were crushed immediately using the Smart Dentin Grinder machine (KometaBio Inc., Cresskill, NJ, USA), a device specially designed for this procedure. The human tooth particles obtained were of 300–1200 microns, obtained by sieving through a special sorting filter, which divided the material into two compartments. The crushed teeth were weighed on a microscale, and scanning electron microscopy (SEM) evaluation was performed. After processing, 0.25 gr of human teeth produced 1.0 cc of biomaterial. Significant differences in tooth weight were found between the first and second upper molars compared with the lower molars. The chemical composition of the particulate was clearly similar to natural bone. Scanning electron microscopy–energy dispersive X-ray (SEM–EDX) analysis of the tooth particles obtained mean results of Ca% 23.42 ± 0.34 and P% 9.51 ± 0.11. Pore size distribution curves expressed the interparticle pore range as one small peak at 0.0053 µm. This result is in accordance with helium gas pycnometer findings; the augmented porosity corresponded to interparticle spaces and only 2.533% corresponded to intraparticle porosity. Autogenous tooth particulate biomaterial made from human extracted teeth may be considered a potential material for bone regeneration due to its chemical composition and the quantity obtained. After grinding the teeth, the resulting material increases in quantity by up to three times its original volume, such that two extracted mandibular lateral incisors teeth will provide a sufficient amount of material to fill four empty mandibular alveoli. The tooth particles present intra and extra pores up to 44.48% after pycnometer evaluation in order to increase the blood supply and support slow resorption of the grafted material, which supports healing and replacement resorption to achieve lamellar bone. After SEM–EDX evaluation, it appears that calcium and phosphates are still present within the collagen components even after the particle cleaning procedures that are conducted before use.
Bottom-Up Self-Assembled Supramolecular Structures Built by STM at the Solid/Liquid Interface
Authors: Ferreira Quirina , Delfino Catarina L. , Morgado Jorge , Alcácer Luís
Published: January 2019

One of the lines of research on organic devices is focused on their miniaturization to obtain denser and faster electronic circuits. The challenge is to build devices adding atom by atom or molecule by molecule until the desired structures are achieved. To do this job, techniques able to see and manipulate matter at this scale are needed. Scanning tunneling microscopy (STM) has been the selected technique by scientists to develop smart and functional unimolecular devices. This review article compiles the latest developments in this field giving examples of supramolecular systems monitored and fabricated at the molecular scale by bottom-up approaches using STM at the solid/liquid interface.
Oxidative Profile of Patients with Sickle Cell Disease
Authors: Antwi-Boasiako Charles , B. Dankwah Gifty , Aryee Robert , Hayfron-Benjamin Charles , S. Donkor Eric , D. Campbell Andrew
Published: January 2019

Oxidative stress plays a very significant role in the pathophysiology of sickle cell disease (SCD) and associated complications. Oxidative stress, which is often experienced by SCD patients as a result of continuous production of reactive oxygen species (ROS), may lead to endothelial dysfunction and acute inflammation. Antioxidant enzymes, such as superoxide dismutase (SOD) and catalase (CAT), often play a protective role. The current study aimed at determining the oxidative profile of persons with SCD at a tertiary hospital in Ghana. This was a case-control study involving 90 patients with SCD (34 HbSS patients at steady state, 30 HbSC at steady state, 15 HbSS with vaso-occlusive crisis, 11 HbSC with vaso-occlusive crisis), and 50 HbAA control group. Whole blood samples were collected from the study participants and analyzed for full blood counts. The blood samples were assayed for SOD and CAT as a measure of antioxidant defense, while lipid peroxidation was quantified as malondialdehyde (MDA). The results showed that the levels of SOD and CAT were significantly lower in SCD patients as compared to the control group. Patients with HbSS vaso-occlusive crisis had the lowest levels of SOD and CAT. The difference in SOD levels between HbSS at steady state and HbSC with vaso-occlusive crisis was, however, not significant (p = 0.228). The MDA level was significantly higher in SCD patients compared to the control group. This study concludes that the levels of various antioxidant enzymes (erythrocyte SOD and erythrocyte CAT) and oxidative marker (MDA) and are altered in SCD patients.
The Role of Tissue Transglutaminase in Cancer Cell Initiation, Survival and Progression
Authors: Tabolacci Claudio , De Martino Angelo , Mischiati Carlo , Feriotto Giordana , Beninati Simone
Published: January 2019

Tissue transglutaminase (transglutaminase type 2; TG2) is the most ubiquitously expressed member of the transglutaminase family (EC 2.3.2.13) that catalyzes specific post-translational modifications of proteins through a calcium-dependent acyl-transfer reaction (transamidation). In addition, this enzyme displays multiple additional enzymatic activities, such as guanine nucleotide binding and hydrolysis, protein kinase, disulfide isomerase activities, and is involved in cell adhesion. Transglutaminase 2 has been reported as one of key enzymes that is involved in all stages of carcinogenesis; the molecular mechanisms of action and physiopathological effects depend on its expression or activities, cellular localization, and specific cancer model. Since it has been reported as both a potential tumor suppressor and a tumor-promoting factor, the role of this enzyme in cancer is still controversial. Indeed, TG2 overexpression has been frequently associated with cancer stem cells’ survival, inflammation, metastatic spread, and drug resistance. On the other hand, the use of inducers of TG2 transamidating activity seems to inhibit tumor cell plasticity and invasion. This review covers the extensive and rapidly growing field of the role of TG2 in cancer stem cells survival and epithelial–mesenchymal transition, apoptosis and differentiation, and formation of aggressive metastatic phenotypes.
In Situ Mechanical Characterization of the Mixed-Mode Fracture Strength of the Cu/Si Interface for TSV Structures
Authors: Wu Chenglin , Wei Congjie , Li Yanxiao
Published: January 2019

In situ nanoindentation experiments have been widely adopted to characterize material behaviors of microelectronic devices. This work introduces the latest developments of nanoindentation experiments in the characterization of nonlinear material properties of 3D integrated microelectronic devices using the through-silicon via (TSV) technique. The elastic, plastic, and interfacial fracture behavior of the copper via and matrix via interface were characterized using small-scale specimens prepared with a focused ion beam (FIB) and nanoindentation experiments. A brittle interfacial fracture was found at the Cu/Si interface under mixed-mode loading with a phase angle ranging from 16.7° to 83.7°. The mixed-mode fracture strengths were extracted using the linear elastic fracture mechanics (LEFM) analysis and a fracture criterion was obtained by fitting the extracted data with the power-law function. The vectorial interfacial strength and toughness were found to be independent with the mode-mix.
Adhesion to Mineral Surfaces by Cells of Leptospirillum, Acidithiobacillus and Sulfobacillus from Armenian Sulfide Ores
Authors: Vardanyan Arevik , Vardanyan Narine , Khachatryan Anna , Zhang Ruiyong , Sand Wolfgang
Published: January 2019

Bioleaching of metal sulfides is an interfacial process where adhesion and subsequent biofilm formation are considered to be crucial for this process. In this study, adhesion and biofilm formation by several acidophiles (Acidithiobacillus, Leptospirillum and Sulfobacillus) isolated from different biotopes with sulfide ores in Armenia were studied. Results showed that: (1) these bacteria adhere to pyrite surfaces to various extents. A correlation between pyrite biooxidation and adhesion of S. thermosulfidooxidans 6, L. ferriphilum CC, L. ferrooxidans ZC on pyrite surfaces is shown. It is supposed that bioleaching of pyrite by S. thermosulfidooxidans 6, L. ferriphilum CC, L. ferrooxidans ZC occurs by means of indirect leaching: by ferric iron of bacterial origin; (2) cells of At. ferrooxidans 61, L. ferrooxidans ZC and St. thermosulfidooxidans 6 form a monolayer biofilm on pyrite surfaces. The coverage of pyrite surfaces varies among these species. The order of the biofilm coverage is: L. ferrooxidans ZC ≥ At. ferrooxidans 61 > St. thermosulfidooxidans 6; (3) the extracellular polymeric substances (EPS) analysis indicates that the tested strains produce EPS, if grown either on soluble ferrous iron or solid pyrite. EPS are mainly composed of proteins and carbohydrates. Cells excrete higher amounts of capsular EPS than of colloidal EPS. In addition, cells grown on pyrite produce more EPS than ones grown on ferrous iron.
Electrochemical Behavior of Ocean Polymetallic Nodules and Low-Grade Nickel Sulfide Ore in Acidithiobacillus Ferrooxidans-Coupled Bio-Leaching
Authors: Kang Jin-Xing , Feng Ya-Li , Li Hao-Ran , Du Zhu-Wei , Deng Xiang-Yi , Wang Hong-Jun
Published: January 2019

Efficient extraction of Ni, Co, Cu, and Mn from low-grade and refractory ores is a common technical challenge. The present study proposes an Acidithiobacillus ferrooxidans-coupled leaching of Ni, Cu, Co, and Mn from oceanic polymetallic nodules and low-grade nickel sulfide ore, and focuses on the electrochemical behavior of the ores in simulated bio-leaching solutions. In the dissolution of polymetallic nodules, A. ferrooxidans facilitates the diffusion of H+ and accelerates electron transfer, producing a decrease in charge transfer resistance and promoting the Mn(IV)-preceding reaction. The use of A. ferrooxidans is beneficial for lower impedance of sulfur-nickel ore, faster diffusion rate of product layer, and better transformation of the Fe3+/Fe2+ couple and S0/S2− couple. A. ferrooxidans increases the potential difference between the nodule cathode and sulfide anode, and increases electron liberation from the sulfide ore. This motivates a significant increase in the average extraction rates of Ni, Co, Cu, and Mn in the bacterial solution. The bio-leaching efficiencies of Ni, Co, Cu, and Mn were as high as 95.4%, 97.8%, 92.2% and 97.3%, respectively, representing improvements of 17.1%, 11.5%, 14.3% and 12.9% relative to that of the germ- and Fe(III)-free acidic 9 K basic system.
Direct Observation of Structure and Dynamics of Photogenerated Charge Carriers in Poly(3-hexylthiophene) Films by Femtosecond Time-Resolved Near-IR Inverse Raman Spectroscopy
Authors: Takaya Tomohisa , Enokida Ippei , Furukawa Yukio , Iwata Koichi
Published: January 2019

The initial charge separation process of conjugated polymers is one of the key factors for understanding their conductivity. The structure of photogenerated transients in conjugated polymers can be observed by resonance Raman spectroscopy in the near-IR region because they exhibit characteristic low-energy transitions. Here, we investigate the structure and dynamics of photogenerated transients in a regioregular poly(3-hexylthiophene) (P3HT):[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) blend film, as well as in a pristine P3HT film, using femtosecond time-resolved resonance inverse Raman spectroscopy in the near-IR region. The transient inverse Raman spectrum of the pristine P3HT film at 50 ps suggests coexistence of neutral and charged excitations, whereas that of the P3HT:PCBM blend film at 50 ps suggests formation of positive polarons with a different structure from those in an FeCl3-doped P3HT film. Time-resolved near-IR inverse Raman spectra of the blend film clearly show the absence of charge separation between P3HT and PCBM within the instrument response time of our spectrometer, while they indicate two independent pathways of the polaron formation with time constants of 0.3 and 10 ps.
Metrological and Critical Characterization of the Intel D415 Stereo Depth Camera
Authors: Carfagni Monica , Furferi Rocco , Governi Lapo , Santarelli Chiara , Servi Michaela , Uccheddu Francesca , Volpe Yary
Published: January 2019

Low-cost RGB-D cameras are increasingly being used in several research fields, including human–machine interaction, safety, robotics, biomedical engineering and even reverse engineering applications. Among the plethora of commercial devices, the Intel RealSense cameras have proven to be among the most suitable devices, providing a good compromise between cost, ease of use, compactness and precision. Released on the market in January 2018, the new Intel model RealSense D415 has a wide acquisition range (i.e., ~160–10,000 mm) and a narrow field of view to capture objects in rapid motion. Given the unexplored potential of this new device, especially when used as a 3D scanner, the present work aims to characterize and to provide metrological considerations for the RealSense D415. In particular, tests are carried out to assess the device performance in the near range (i.e., 100–1000 mm). Characterization is performed by integrating the guidelines of the existing standard (i.e., the German VDI/VDE 2634 Part 2) with a number of literature-based strategies. Performance analysis is finally compared against the latest close-range sensors, thus providing a useful guidance for researchers and practitioners aiming to use RGB-D cameras in reverse engineering applications.
Commodifying Lisbon: A Study on the Spatial Concentration of Short-Term Rentals
Authors: Lestegás Iago , Seixas João , Lois-González Rubén-Camilo
Published: January 2019

This article explores the relationship between the spatial concentration of short-term rentals in Lisbon’s historic center and the phenomena of uneven development and tourism gentrification. By providing quantitative and qualitative evidence of the uneven geographic distribution of tourist apartments within the municipality of Lisbon, it contributes to the study of the new processes of neoliberal urbanization in the crisis-ridden countries of Southern Europe. It argues that the great share of whole-home rentals and the expansion of the short-term rental market over the housing stock are symptoms of the commodification of housing in the neoliberal city. Due to the loss of consumption capacity by the Portuguese society amid crisis and austerity, real estate developers target external markets and local households must compete for access to a limited housing stock with tourists and other temporary city users. The subsequent global rent gap stimulates the proliferation of vacation rentals at the expense of the supply of residential housing, fueling property prices and jeopardizing housing affordability. With Portugal being a peripheral member of the EU and the Eurozone, the vulnerability of local households to the impacts of tourism gentrification is aggravated by the remarkable income gap with their counterparts of the core.
Green Roof Design Techniques to Improve Water Use under Mediterranean Conditions
Authors: Paço Teresa A. , Cruz de Carvalho Ricardo , Arsénio Pedro , Martins Diana
Published: January 2019

Green roof typology can vary depending on buildings structure, climate conditions, substrate, and plants used. In regions with hot and dry summers, such as the Mediterranean region, irrigation plays an essential role, as the highest temperatures occur during the driest period of the year. Irrigation might reduce the heat island effect and improve the cooling of buildings during this period, however, the added cost of maintenance operations and additional energy consumption could outrun the benefits provided by the project. Moreover, in situations where water is scarce or primarily channelled to other uses (e.g., domestic, agriculture or industry) during drought occurrence, it is advisable to implement green roof projects with the lowest use of water possible. The objective of the present work is to investigate solutions to optimize water use in green roofs under Mediterranean conditions, such as those of southern Europe. Two case studies are presented for Portugal, and potential techniques to reduce irrigation requirements in green roofs were tested. These addressed the use of native plant species, including the extreme type of a non-irrigated green roof (Biocrust roof) and techniques for plant installation. Plant drought tolerance was found to be an advantage in green roofs under these climatic conditions and, for the species studied, aesthetic value could be maintained when irrigation decreased.
Conflicts about Urban Green Spaces in Metropolitan Areas under Conditions of Climate Change: A Multidisciplinary Analysis of Stakeholders’ Perceptions of Planning Processes
Authors: Wagner Madeleine , Mager Christoph , Schmidt Nicole , Kiese Nina , Growe Anna
Published: January 2019

Under conditions of climate change, land-use conflicts are a significant challenge for spatial planning, especially in densely populated metropolitan regions. By using a multi-methodological approach, this study aims to identify different stakeholders’ perceptions of these spaces in planning processes within urban areas in Germany. We use an ecosystem service analysis to evaluate the ecological potential of each selected study area and conducted a household survey to gauge how the local population and administration perceive them. The perceptions of these two groups of stakeholders regarding each area’s spatial qualities often differed from their actual ecological potential. We conducted interviews to identify possible conflicts between politicians and administration staff. While cooperation between politicians and the administration staff takes place and works well, the stakeholders involved often evaluate and perceive the cooperation processes in planning differently. Therefore, the authors argue that an integrative and methodologically multi-layered approach is useful for understanding complex perceptions in spatial planning.
Working capital management and its influence on profitability and sustainable growth
Authors: Nastiti Pambayun Kinasih Yekti , Atahau Apriani Dorkas Rambu , Supramono Supramono
Published: January 2019

This study aims to test the effect of working capital management on firms’ profitability and the effect of this relationship on sustainable growth. Our sample firms are 136 manufacturing firms listed in the Indonesian Stock Exchange from 2010 to 2017. We use data panel regression with fixed effect estimation model to analyze our data. The results demonstrate that working capital significantly affects firms’ profitability. However, working capital management does not exhibit a significant direct influence on sustainable growth but a significant indirect influence through firms’ profitability. Thus, this study suggests that firms need to manage their working capital to increase their profits and eventually to achieve sustainable growth. This study contributes by including sustainable growth in the analysis of the relationship between working capital and firm performance. In addition, this study will likely contribute to managers in efforts to increase sustainable growth for their enterprises through working capital management.
Dust Attenuation, Star Formation, and Metallicity in z ∼ 2–3 Galaxies from KBSS-MOSFIRE
Authors: Theios Rachel L. , Steidel Charles C. , Strom Allison L. , Rudie Gwen C. , Trainor Ryan F. , Reddy Naveen A.
Published: January 2019

We present a detailed analysis of 317 2.0 ≤ z ≤ 2.7 star-forming galaxies from the Keck Baryonic Structure Survey. Using complementary spectroscopic observations with Keck/LRIS and Keck/MOSFIRE, as well as spectral energy distribution (SED) fits to broadband photometry, we examine the joint rest-UV and rest-optical properties of the same galaxies, including stellar and nebular dust attenuation, metallicity, and star formation rate (SFR). The inferred parameters of the stellar population (reddening, age, SFR, and stellar mass) are strongly dependent on the details of the assumed stellar population model and the shape of the attenuation curve. Nebular reddening is generally larger than continuum reddening, but with large scatter. Compared to local galaxies, high-redshift galaxies have lower gas-phase metallicities (and/or higher nebular excitation) at fixed nebular reddening, and higher nebular reddening at fixed stellar mass, consistent with gas fractions that increase with redshift. We find that continuum reddening is correlated with 12 + log(O/H)O3N2 at 3.0σ significance, whereas nebular reddening is correlated with only 1.1σ significance. This may reflect the dependence of both continuum reddening and O3N2 on the shape of the ionizing radiation field produced by the massive stars. Finally, we show that Hα-based and SED-based estimates of SFR exhibit significant scatter relative to one another, and on average agree only for particular combinations of spectral synthesis models and attenuation curves. We find that the SMC extinction curve predicts consistent SFRs if we assume the subsolar (0.14 Z
⊙) binary star models that are favored for high-redshift galaxies.
The Short GRB 170817A: Modeling the Off-axis Emission and Implications on the Ejecta Magnetization
Authors: Fraija N. , Colle F. De , Veres P. , Dichiara S. , Duran R. Barniol , Galvan-Gamez A. , do E. S. Pedreira A. C. Caligula
Published: January 2019

The short GRB 170817A, detected by the Fermi Gamma-ray Burst Monitor, orbiting satellites and ground-based telescopes, was the electromagnetic counterpart of a gravitational-wave transient (GW170817) from a binary neutron star merger. After this merger, the γ-ray light curve exhibited a faint peak at ∼1.7 s and the X-ray, optical, and radio light curves displayed extended emission that increased in brightness up to ∼160 days. In this paper, we show that the X-ray, optical and radio fluxes are consistent with the synchrotron forward-shock model viewed off-axis when the matter in the outflow is parameterized through a power-law velocity distribution. We discuss the origin of the γ-ray peak in terms of internal and external shocks. We show that the γ-ray flux might be consistent with a synchrotron self-Compton reverse-shock model observed at high latitudes. Comparing the best-fit values obtained after describing the γ-ray, X-ray, optical, and radio fluxes with our model, we find that the afterglow and γ-ray emission occurred in different regions and also find evidence to propose that the progenitor environment was entrained with magnetic fields; therefore we argue for the presence of magnetic field amplification in the binary neutron star merger.
Does High-density or Mass Help Star Clusters Produce X-Ray Binaries in Star-forming Galaxies?
Authors: Johns Mulia P. , Chandar R. , Rangelov B.
Published: January 2019

It is now widely accepted that many X-ray binaries (XRBs) form in compact star clusters. Therefore, it follows that there may be a link between the properties of star clusters and the production of XRBs. We study the masses and densities of compact clusters with different ages found in the merging Antennae galaxies and in the dwarf starburst NGC 4449, to assess their impact on the production of XRBs. The very youngest clusters, with ages log (τ/yr) < 7.0, likely host high-mass XRBs, while older clusters with ages log (τ/yr) = 7.0–8.6 host intermediate-mass XRBs. We find tentative evidence that intermediate-mass XRBs are more likely to form in more massive and dense clusters, while high-mass XRBs do not appear to form in clusters that favor higher masses or densities. If confirmed, these findings support a picture where high-mass and intermediate-mass XRBs form through different mechanisms.
The Circular Velocity Curve of the Milky Way from 5 to 25 kpc
Authors: Eilers Anna-Christina , Hogg David W. , Rix Hans-Walter , Ness Melissa K.
Published: January 2019

We measure the circular velocity curve v
c(R) of the Milky Way with the highest precision to date across Galactocentric distances of 5 ≤ R ≤ 25 kpc. Our analysis draws on the six-dimensional phase-space coordinates of ≳23,000 luminous red giant stars, for which we previously determined precise parallaxes using a data-driven model that combines spectral data from APOGEE with photometric information from WISE, 2MASS, and Gaia. We derive the circular velocity curve with the Jeans equation assuming an axisymmetric gravitational potential. At the location of the Sun we determine the circular velocity with its formal uncertainty to be

=

with systematic uncertainties at the ∼2%–5% level. We find that the velocity curve is gently but significantly declining at (−1.7 ± 0.1) km s−1 kpc−1, with a systematic uncertainty of 0.46 km s−1 kpc−1, beyond the inner 5 kpc. We exclude the inner 5 kpc from our analysis due to the presence of the Galactic bar, which strongly influences the kinematic structure and requires modeling in a nonaxisymmetric potential. Combining our results with external measurements of the mass distribution for the baryonic components of the Milky Way from other studies, we estimate the Galaxy’s dark halo mass within the virial radius to be

=

and a local dark matter density of

=

.
A Comparison between Radio Loud and Quiet Gamma-Ray Bursts, and Evidence for a Potential Correlation between Intrinsic Duration and Redshift in the Radio Loud Population
Authors: Lloyd-Ronning Nicole M. , Gompertz Ben , Pe’er Asaf , Dainotti Maria , Fruchter Andy
Published: January 2019

We extend our study of energetic radio-loud and -quiet gamma-ray bursts (GRBs), suggesting these GRBs potentially come from two separate progenitor systems. We expand the sample from our previous paper and find that our results are strengthened—radio-quiet GRBs have significantly shorter intrinsic prompt duration, and are also less energetic on average. However, the tenuous correlation between isotropic energy and intrinsic duration in the radio dark sample remains tenuous and is slightly weakened by adding more bursts. Interestingly, we find an anticorrelation between the intrinsic duration and redshift in the radio bright sample but not the radio dark sample, further supporting that these two samples may come from separate progenitors. We also find that very high energy (0.1–100 GeV) extended emission is only present in the radio-loud sample. There is no significant difference between the presence of X-ray/optical plateaus or the average jet opening angles between the two samples. We explore the interpretation of these results in the context of different progenitor models. The data are consistent with the radio-loud GRBs coming from a helium merger system and the radio-quiet GRBs coming from a collapsar system, but may also reflect other dichotomies in the inner engine such as a neutron star versus black hole core.
Black Hole Hyperaccretion Inflow–Outflow Model. II. Long-duration Gamma-Ray Bursts and Supernova 56Ni Bumps
Authors: Song Cui-Ying , Liu Tong
Published: January 2019

Long-duration gamma-ray bursts (LGRBs) associated with supernovae (SNe) are possibly born out of the death of a massive star. After the star collapses, a stellar-mass black hole (BH) is formed, surrounded by a hyperaccretion disk with outflows. Blandford–Znajek jets can be launched and then break out from the envelope to power LGRBs. The jet luminosity depends on the net inflow accretion rate at the inner radius of the disk. Furthermore, 56Ni synthesis should occur in the strong outflows from the accretion disk. The decay of 56Ni is considered to be the possible origin of SN bumps in the subsequent optical afterglows of LGRBs. If 56Ni originates entirely from the outflows, there is competition between the luminosities of LGRBs and those of the corresponding 56Ni bumps because of the material distribution between the disk inflows and outflows. In this paper, we investigated these two luminosities based on 15 cases of LGRB–SN in the framework of the BH hyperaccretion inflow–outflow model. Then, one can constrain the characteristics of the progenitor stars of these LGRBs. The results indicate that these LGRBs may originate from the low-metallicity (

, where Z and Z
⊙ are the metallicities of the stars and the Sun, respectively) stars or some massive solar-metallicity stars. For ultra-LGRBs (ULGRBs), such as GRB 111209A, most of the massive low-metallicity stars with

could be progenitors only if very strong outflows are launched from the disks. When the contributions of nucleosynthesis in the disk outflows are considered, there is no shortage of 56Ni mass for luminous SNe associated with ULGRBs.
Evidence for Optically Thick, Eddington-limited Winds Driven by Supercritical Accretion
Authors: Zhou Yu , Feng Hua , Ho Luis C. , Yao Yuhan
Published: January 2019

Supercritical accretion onto compact objects powers a massive wind that is optically thick and Eddington-limited. If most of the hard X-rays from the central disk are obscured by the wind, the source will display a blackbody-like spectrum with a luminosity scaled with the mass of the compact object. From the Chandra archive of nearby galaxies, we selected a sample of luminous and very soft sources and excluded contamination from foreground objects and supernova remnants. They are found to be preferentially associated with late-type galaxies. The majority of sources in our sample are either too hot or too luminous to be explained by nuclear burning on the surface of white dwarfs, and are argued to be powered by accretion. The most likely explanation is that they are due to emission from the photosphere of a wind driven by supercritical accretion onto compact objects. Their blackbody luminosity ranges from ∼1037 to nearly 1040 erg s−1, indicative of the presence of both neutron stars and stellar-mass black holes. The blackbody luminosity also shows a possible bimodal distribution, albeit at low significance, peaked around the Eddington limit for neutron stars and stellar-mass black holes, respectively. If this can be confirmed, it will be smoking gun evidence that supercritical accretion powers thick winds. Based on a wind model, the inferred mass accretion rate of these objects is around a few hundred times the Eddington rate, suggesting that they may be intermediate between the canonical ultraluminous X-ray sources and SS 433 in terms of the accretion rate.
Hubble Constant from LSST Strong-lens Time Delays with Microlensing Systematics
Authors: Liao Kai
Published: January 2019

Strong-lens time delays have been widely used in cosmological studies, especially to infer H
0. The upcoming LSST will provide several hundred well-measured time delays from the light curves of lensed quasars. However, due to the inclination of the finite AGN accretion disk and the differential magnification of the coherent temperature fluctuations, the microlensing by the stars can lead to changes in the actual time delay on the light-crossing timescale of the emission region of ∼days. We first study how this would change the uncertainty of H
0 in the LSST era, assuming the microlensing time delays can be well estimated. We adopt 1/3, 1, and 3 days respectively as the typical microlensing time-delay uncertainties. The relative uncertainty of H
0 will be enlarged to 0.47%, 0.51%, and 0.76%, from the uncertainty without the microlensing, impact 0.45%. Then, due to our lack of understanding of the quasar models and microlensing patterns, we also test the reliability of the results if one neglects this effect in the analysis. The biases of H
0 will be 0.12%, 0.22% and 0.70%, suggesting that 1 day is the cutoff for a robust H
0 estimate.
Gas Density Perturbations Induced by One or More Forming Planets in the AS 209 Protoplanetary Disk as Seen with ALMA
Authors: Favre Cécile , Fedele Davide , Maud Luke , Booth Richard , Tazzari Marco , Miotello Anna , Testi Leonardo , Semenov Dmitry , Bruderer Simon
Published: January 2019

The formation of planets occurs within protoplanetary disks surrounding young stars, resulting in perturbation of the gas and dust surface densities. Here we report the first evidence of spatially resolved gas surface density (Σ
g
) perturbation toward the AS 209 protoplanetary disk from the optically thin C18O (J = 2−1) emission. The observations were carried out at 1.3 mm with Atacama Large Millimeter/submillimeter Array at a spatial resolution of about 0.″3 × 0.″2 (corresponding to ∼38 × 25 au). The C18O emission shows a compact (≤60 au), centrally peaked emission and an outer ring peaking at 140 au, consistent with that observed in the continuum emission, and its azimuthally averaged radial intensity profile presents a deficit that is spatially coincident with the previously reported dust map. This deficit can only be reproduced with our physico-thermochemical disk model by lowering Σgas by nearly an order of magnitude in the dust gaps. Another salient result is that, contrary to C18O, the DCO+ (J = 3−2) emission peaks between the two dust gaps. We infer that the best scenario to explain our observations (C18O deficit and DCO+ enhancement) is a gas perturbation due to one or more forming planets, which is commensurate with previous continuum observations of the source along with hydrodynamical simulations. Our findings confirm that the previously observed dust gaps are very likely due to perturbation of the gas surface density that is induced by a planet of at least 0.2M
J in formation. Finally, our observations also show the potential of using CO isotopologues to probe the presence of one or more Saturn-mass planets.
The Galactic Magneto-ionic Medium Survey: Moments of the Faraday Spectra
Authors: Dickey John M. , Landecker T. L. , Thomson Alec J. M. , Wolleben M. , Sun X. , Carretti E. , Douglas K. , Fletcher A. , Gaensler B. M. , Gray A. , Haverkorn M. , Hill A. S. , Mao S. A. , McClure-Griffiths N. M.
Published: January 2019

Faraday rotation occurs along every line of sight in the Galaxy; rotation measure (RM) synthesis allows a 3D representation of the interstellar magnetic field. This study uses data from the Global Magneto-Ionic Medium Survey, a combination of single-antenna spectro-polarimetric studies, including northern sky data from the Dominion Radio Astrophysical Observatory (DRAO) 26 m telescope (1270–1750 MHz) and southern sky data from the Parkes 64 m telescope (300–480 MHz). From the synthesized Faraday spectral cubes we compute the zeroth, first, and second moments to find the total polarized emission, mean RM, and RM width of the polarized emission. From DRAO first moments we find a weak vertical field directed from Galactic North to South, but Parkes data reveal fields directed toward the Sun at high latitudes in both hemispheres: the two surveys clearly sample different volumes. DRAO second moments show feature widths in Faraday spectra increasing with decreasing positive latitudes, implying that longer lines of sight encounter more Faraday rotating medium, but this is not seen at negative latitudes. Parkes data show the opposite: at positive latitudes the second moment decreases with decreasing latitude, but not at negative latitudes. Comparing first moments with RMs of pulsars and extragalactic sources and a study of depolarization together confirm that the DRAO survey samples to larger distances than the Parkes data. Emission regions in the DRAO survey are typically 700–1000 pc away, slightly beyond the scale height of the magneto-ionic medium; emission detected in the Parkes survey is entirely within the magneto-ionic disk, less than 500 pc away.
Characteristics of Plasma Cavities That Appeared in the Intensity Dropout Event of Solar Energetic Particles
Authors: Tan Lun C.
Published: January 2019

In order to explore the origin of the particle “dropout” phenomenon in the “gradual” solar energetic particle (SEP) event, we have selected 13 dropout intervals from 10 gradual SEP events during solar cycle 23. Our selection criterion is that within the dropout interval the average slab turbulence fraction is >0.8 in the ion dissipation range. In the plasma “cavity” that appeared in the dropout interval we have observed the angles of the wavenumber vector and the solar wind velocity vector relative to the mean magnetic field direction to be ∼0° and ∼90°, respectively. The distinctive feature of the cavity geometry could inhibit the occurrence of kinetic Alfvén waves (KAWs), leaving the dominance of magnetosonic-whistler waves in its plasma environment. Therefore, by examining the difference of turbulence characteristics between the dropout interval and the ambient solar wind, we are able to differentiate between the effects of KAWs and quasi-parallel whistler waves. Observations of the plasma β dependence of magnetic power density spectra in the ion dissipation range indicate that in the cavity of low plasma β (≤1) and low magnetic variance anisotropy (∼3) the turbulence cascade of the magnetosonic-whistler wave branch has reached a sufficiently developed stage.
Morphology and multigene phylogeny of Talaromyces amyrossmaniae, a new synnematous species belonging to the section Trachyspermi from India
Authors: Rajeshkumar Kunhiraman C. , Yilmaz Neriman , Marathe Sayali D. , Seifert Keith A.
Published: January 2019

A newTalaromycesspecies,T.amyrossmaniae, isolated from decaying fruit and litter ofTerminalia bellerica, is described and illustrated. On the natural substrate, the new species produces determinate synnemata, with a well-defined, vivid orange red to orange red cylindrical stipe, and a greyish green capitulum. Conidiophores are typically biverticillate, or sometimes have subterminal branches, with acerose phialides that produce globose to subglobose, smooth to slightly roughened conidia. Multigene phylogenetic analyses based on the internal transcribed spacer region (ITS), and partial sequences of β-tubulin (BenA), calmodulin (CaM), and DNA directed RNA polymerase second large subunit (RPB2) genes, along with morphological characterization, revealed that these isolates are distinct and form a unique lineage of Talaromyces in section Trachyspermi, closely allied toT.aerius,T.albobiverticillius,T.heiheensis,T.erythromellis, andT.solicola. The new speciesT.amyrossmaniaeis the first species in section Trachyspermi with determinate synnemata.
The identity of the Sri Lankan Amblypharyngodon (Teleostei, Cyprinidae)
Authors: Sudasinghe Hiranya , Pethiyagoda Rohan , Maduwage Kalana , Meegaskumbura Madhava
Published: January 2019

Morphological and molecular analyses of specimens representative of the geographic range of the cyprinid genusAmblypharyngodonin Sri Lanka suggest the presence of only a single species in the island, for which the nameAmblypharyngodongrandisquamisJordan & Starks, 1917, is available.Amblypharyngodongrandisquamisis a species endemic to Sri Lanka, distributed across the lowlands of both of the island’s main climatic zones. It is distinguished from all other species ofAmblypharyngodon, including the three species recorded from peninsular India (A.mola,A.microlepis, andA.melettinus), by a suite of characters that includes a body depth of 26.9–31.2% of the standard length (SL), 42–56 scales in the lateral series (of which usually 8–16 are pored), 20–24 circumpeduncular scales, 14–17 scale rows between the origins of the dorsal and pelvic fins, a dorsal-fin height of 21.1–27.6% SL, 18–19 caudal vertebrae and an eye diameter of 22.7–30.5% of the head length.Amblypharyngodongrandisquamisdiffers fromA.melettinusandA.molaby uncorrected pairwise genetic distances of more than 9% and 6%, respectively, for the mitochondrial cytochrome oxidase subunit 1 (COI) gene.
A new species of Tenuibaetis Kang & Yang, 1994 from Indonesia (Ephemeroptera, Baetidae)
Authors: Kaltenbach Thomas , Gattolliat Jean-Luc
Published: January 2019

A new species ofTenuibaetisKang & Yang is described and illustrated based on larvae collected in Java in 2010, which is the most southeastern report of this genus to date. The total number ofTenuibaetisspecies is thereby augmented to seven. The morphological differences of all other species are discussed and summarised in tabular form.