bluuebunny/crossref_metadata_2025 huggingface dataset:
Survey of Finite Element Method-Based Real-Time Simulations
Authors: Marinkovic Dragan , Zehn Manfred
Published: July 2019

The finite element method (FEM) has deservedly gained the reputation of the most powerful, highly efficient, and versatile numerical method in the field of structural analysis. Though typical application of FE programs implies the so-called “off-line” computations, the rapid pace of hardware development over the past couple of decades was the major impetus for numerous researchers to consider the possibility of real-time simulation based on FE models. Limitations of available hardware components in various phases of developments demanded remarkable innovativeness in the quest for suitable solutions to the challenge. Different approaches have been proposed depending on the demands of the specific field of application. Though it is still a relatively young field of work in global terms, an immense amount of work has already been done calling for a representative survey. This paper aims to provide such a survey, which of course cannot be exhaustive.
A Short-Term Forecast Model of foF2 Based on Elman Neural Network
Authors: Fan Jieqing , Liu Chao , Lv Yajing , Han Jing , Wang Jian
Published: July 2019

The critical frequency foF2 of the ionosphere F2 layer is one of the most important parameters of the ionosphere. Based on the Elman neural network (ENN), this paper constructs a single station forecasting model to predict foF2 one hour ahead. In order to avoid the network falling into local minimum, the model is optimized by the improved particle swarm optimization (IPSO). The input parameters used in the model include local time, seasonal information, solar cycle information and magnetic activity information. Data of the Wuhan Station from 2008 to 2016 were used to train and test the model. The prediction results of foF2 show that the root mean square error (RMSE) of the Elman neural network model is 4.30% lower than that of the back-propagation neural network (BPNN) model. The RMSE is further reduced by 8.92% after using the IPSO to optimize the model. This indicates that the Elman neural network model optimized by the improved particle swarm optimization is superior to the BP neural network and Elman neural network in the forecast of foF2 one hour ahead at Wuhan station.
Evaluation of Short-Term Aging Protocol for Asphalt Mixtures
Authors: Sirin Okan , Paul Dalim K. , Kassem Emad , Ohiduzzaman Md
Published: July 2019

Asphalt mixtures are subjected to short-term aging during the production, placement, and compaction processes. Proper evaluation of asphalt pavement performance relies on the accurate characterization of asphalt mixtures during the design stage. In this study, three different loose asphalt mixtures often used in Qatar were evaluated to develop a laboratory short-term aging procedure. Sample mixtures 1 and 3 were collected from a construction site, while mixture 2 was obtained from an asphalt plant. Virgin aggregates and binders were also collected to reproduce the mixtures in the laboratory. Laboratory-produced mixtures were conditioned at 135 °C using various time durations. The mechanical properties of laboratory-produced mixtures were compared to those of mixtures produced on site. The results of the mechanical and binder testing demonstrated that the proper short-term aging protocol for asphalt mixtures often used in road construction in the State of Qatar would involve heating asphalt mixtures for 4 h at 135 °C before laboratory compaction.
Applications of Photogrammetric Modeling to Roman Wall Painting: A Case Study in the House of Marcus Lucretius
Authors: McClinton Kelly E.
Published: July 2019

Across many sites in Italy today, wall paintings face particular dangers of damage and destruction. In Pompeii, many extant fragments are open to the air and accessible to tourists. While efforts are underway to preserve the precious few examples that have come down to us today, after excavation even new finds begin to decay from the moment they are exposed to the air. Digital photogrammetry has been used for the documentation, preservation, and reconstruction of archaeological sites, small objects, and sculpture. Photogrammetry is also well-suited to the illustration and reconstruction of Roman wall painting and Roman domestic interiors. Unlike traditional photography, photogrammetry can offer three-dimensional (3D) documentation that captures the seams, cracks, and warps in the structure of the wall. In the case of an entire room, it can also preserve the orientation and visual impression of multiple walls in situ. This paper discusses the results of several photogrammetric campaigns recently undertaken to document the material record in the House of Marcus Lucretius at Pompeii (IX, 3, 5.24). In the process, it explores the combination of visual analysis with digital tools, and the use of 3D models to represent complex relationships between spaces and objects. To conclude, future avenues for research will be discussed, including the creation of an online database that would facilitate visualizing further connections within the material record.
Application of GCM Bias Correction to RCM Simulations of East Asian Winter Climate
Authors: Lim Chang-Mook , Yhang Yoo-Bin , Ham Suryun
Published: July 2019

Both the global circulation model (GCM) and regional climate model (RCM) simulations suffer from model biases that eventually result in significant errors in regional forecasts. This model bias issue is addressed using the bias correction approach. This study examines the influence of bias correction on the performance of downscaling simulations of the East Asian winter climate using the Global/Regional Integrated Model system (GRIMs). To assess the bias correction approach, we conducted three sets of simulations for 25 winters (December to February) from 1982 to 2006 over East Asia. The GRIMs were forced by the (1) National Centers for Environmental Prediction (NCEP) Department of Energy (DOE) reanalysis data, (2) original NCEP Climate Forecast System (CFS) data, and (3) bias-corrected CFS data. The GCM climatological means were adjusted based on the NCEP–DOE reanalysis data. The bias correction method was applied to zonal and meridional wind, temperature, geopotential height, specific humidity, and sea surface temperature of the CFS data. The GCM-driven experiments with/without bias correction were compared with the reanalysis-driven simulation. The results of this comparison suggest that the application of bias correction improves the downscaled climate in terms of the climatological mean, inter-annual variability, and extreme events owing to the elimination of errors in large-scale circulations. The effect of bias correction on the simulated extreme event is not as significant as those on the climatological mean and inter-annual variability, but the increased skill appears to be a clue for potential use for predicting extreme events.
Carbon-Carbon Double Bond and Resorcinol in Resveratrol and Its Analogues: What Is the Characteristic Structure in Quenching Singlet Oxygen?
Authors: Kong Qingjun , Ren Xueyan , Qi Jianrui , Yu Jia , Lu Jun , Wang Shuo
Published: July 2019

Stilbenes, particularly resveratrol and resveratrol dimers, could effectively quench singlet oxygen (1O2). It was reported that both resorcinol and carbon-carbon double bond quenching 1O2 can participate in the mechanism. However, it is still not clear which structure plays a dominant role in quenching 1O2. To investigate the characteristic structure in the mechanism of quenching 1O2, the resveratrol, pterostilbene and piceatannol quenching 1O2 abilities were compared by UHPLC-QTOF-MS2 and UHPLC-QQQ-MS2. Results showed that catechol, carbon-carbon double bond and resorcinol participated in the quenching of 1O2. Catechol ring plays a leading role in the mechanism, and the contribution of the structures in quenching 1O2 activity are as follows: catechol ring > carbon-carbon double bond > resorcinol ring, which is supported by the calculation of energy. Our findings will contribute to the future screening of stilbenes with higher activity, and those stilbenes may have great therapeutic potential in 1O2-mediated diseases.
Molecular Pathways Modulated by Curcumin Analogue, Diarylpentanoids in Cancer
Authors: Paulraj Felicia , Abas Faridah , H. Lajis Nordin , Othman Iekhsan , Naidu Rakesh
Published: July 2019

While curcumin has a range of therapeutic benefits, its potent anticancer activity remains an attractive avenue for anticancer research owing to the multifactorial nature of cancer itself. The structure of curcumin has thus been used as a lead to design more potent analogues, and diarylpentanoids in particular have shown improved cytotoxicity over curcumin. Investigations of diarylpentanoids have demonstrated that these compounds exert anti-cancer effects through several signalling pathways that are associated with cancer. This review focuses on selected diarylpentanoids and highlights molecular targets that modulate key pathways involved in cancer such as NF-κB, MAPK/ERK, and STAT signalling. Future research will need to focus on drug interactions to explore potential synergistic actions of diarylpentanoids and further establish the use of diverse animal models.
Role of Dietary Supplements in the Management of Parkinson’s Disease
Authors: Ciulla Michele , Marinelli Lisa , Cacciatore Ivana , Stefano Antonio Di
Published: July 2019

The use of food supplements or functional food has significantly increased in the past decades, especially to compensate both the modern lifestyle and the food shortages of the industrialized countries. Despite food supplements are habitually intended to correct nutritional deficiencies or to support specific physiological functions, they are often combined with common drug therapies to improve the patient’s health and/or mitigate the symptoms of many chronic diseases such as cardiovascular diseases, cystic fibrosis, cancer, liver and gastrointestinal diseases. In recent years, increased attentions are given to the patient’s diet, and the use of food supplements and functional food rich in vitamins and antioxidants plays a very important role in the treatment and prevention of neurodegenerative diseases such as Parkinson’s disease (PD). Natural compounds, phytochemicals, vitamins, and minerals can prevent, delay, or alleviate the clinical symptoms of PD in contrast to some of the main physiopathological mechanisms involved in the development of the disease, like oxidative stress, free radical formation, and neuroinflammation. The purpose of this review is to collect scientific evidences which support the use of specific biomolecules and biogenic elements commonly found in food supplements or functional food to improve the clinical framework of patients with PD.
Analysis and Identification of Active Compounds from Gami-Soyosan Toxic to MCF-7 Human Breast Adenocarcinoma Cells
Authors: Jung Mi-Yeon , Seo Chang-Seob , Baek Seon-Eun , Lee Jaemin , Shin Myoung-Sook , Kang Ki Sung , Lee Sullim , Yoo Jeong-Eun
Published: July 2019

Gami-soyosan is a medicinal herbal formulation prescribed for the treatment of menopausal symptoms, including hot flashes and osteoporosis. Gami-soyosan is also used to treat similar symptoms experienced by patients with breast cancer. The incidence of breast cancer in women receiving hormone replacement therapy is a big burden. However, little is known about the components and their mechanism of action that exhibit these beneficial effects of Gami-soyosan. The aim of this study was to simultaneously analyze compounds of Gami-soyosan, and determine their cytotoxic effects on estrogen receptor (ER)-positive MCF-7 human breast adenocarcinoma cells. We established a simultaneous analysis method of 18 compounds contained in Gami-soyosan and found that, among the various compounds in Gami-soyosan, gallic acid (1), decursin (17), and decursinol angelate (18) suppressed the viability of MCF-7 cells. Gallic acid (1), decursin (17), and decursinol angelate (18) induced apoptotic cell death and significantly increased poly (ADP-ribose) polymerase (PARP) cleavage and the Bcl-2-associated X protein/ B-cell lymphoma 2 (Bax/Bcl-2) ratio. Decursin (17) increased the expression of cleaved caspases-8, -9, -7, and -3. Decursinol angelate (18) increased the expression of cleaved caspase-8 and -7. These three components altered the different apoptosis signal pathways. Collectively, gallic acid (1), decursin (17), and decursinol angelate (18) may be used to inhibit cell proliferation synergistically in patients with ER-positive breast cancer.
An Approximation of Heart Failure Using Cardiovascular Simulation Toolbox
Authors: Ortiz-León Gabriela , Barrantes-Vargas Heiner José , Arguedas-Sandí Manuel , Pacheco-Chaverri Jose Ángel , Vílchez-Monge Marta
Published: July 2019

In this paper, we present the simulation of 5 different heart failures with the help of the Cardiovascular Simulation Toolbox (CVST) proposed by O. Barnea et al. at Tel-Aviv University. This is a modified version of the CVST, proposed by G.Ortiz; here, we show that the pathological failures can be covered by this tool. We varied the value of the tool blocks, included the results of the hemodynamic parameters and the P-V loop curves for each disease and compared them to the medical data to prove the effectiveness of the simulation. Based on these changes, we achieved an effective simulation of the following heart failures in the CVST: Diastolic Heart Failure (DHF), Systolic Heart Failure (SHF), Right Ventricle Heart Failure (RVHF), Low Output Heart Failure (LOHF) and High Output Heart Failure (HOHF).
The Role of Electrochemical Immunosensors in Clinical Analysis
Authors: Mollarasouli Fariba , Kurbanoglu Sevinc , Ozkan Sibel A.
Published: July 2019

An immunosensor is a kind of affinity biosensor based on interactions between an antigen and specific antigen immobilized on a transducer surface. Immunosensors possess high selectivity and sensitivity due to the specific binding between antibody and corresponding antigen, making them a suitable platform for several applications especially in the medical and bioanalysis fields. Electrochemical immunosensors rely on the measurements of an electrical signal recorded by an electrochemical transducer and can be classed as amperometric, potentiometric, conductometric, or impedimetric depending on the signal type. Among the immunosensors, electrochemical immunosensors have been more perfected due to their simplicity and, especially their ability to be portable, and for in situ or automated detection. This review addresses the potential of immunosensors destined for application in clinical analysis, especially cancer biomarker diagnosis. The emphasis is on the approaches used to fabricate electrochemical immunosensors. A general overview of recent applications of the developed electrochemical immunosensors in the clinical approach is described.
Machilin A Inhibits Tumor Growth and Macrophage M2 Polarization Through the Reduction of Lactic Acid
Authors: Chung Tae-Wook , Kim Eun-Yeong , Han Chang Woo , Park So Young , Jeong Mi Suk , Yoon Dahye , Choi Hee-Jung , Jin Ling , Park Mi-Ju , Kwon Yun Ju , Lee Hanna , Kim Keuk-Jun , Park Kang Hyun , Kim Suhkmann , Jang Se Bok , Ha Ki-Tae
Published: July 2019

Lactate dehydrogenase A (LDHA) is an important enzyme responsible for cancer growth and energy metabolism in various cancers via the aerobic glycolytic pathway. Here, we report that machilin A (MA), which acts as a competitive inhibitor by blocking the nicotinamide adenine dinucleotide (NAD) binding site of LDHA, suppresses growth of cancer cells and lactate production in various cancer cell types, including colon, breast, lung, and liver cancers. Furthermore, MA markedly decreased LDHA activity, lactate production, and intracellular adenosine triphosphate (ATP) levels induced by hypoxia-induced LDHA expression in cancer cells, and significantly inhibited colony formation, leading to reduced cancer cell survival. In mouse models inoculated with murine Lewis lung carcinoma, MA significantly suppressed tumor growth as observed by a reduction of tumor volume and weight; resulting from the inhibition of LDHA activity. Subsequently, the suppression of tumor-derived lactic acid in MA-treated cancer cells resulted in decrease of neovascularization through the regulation of alternatively activated macrophages (M2) polarization in macrophages. Taken together, we suggest that the reduction of lactate by MA in cancer cells directly results in a suppression of cancer cell growth. Furthermore, macrophage polarization and activation of endothelial cells for angiogenesis were indirectly regulated preventing lactate production in MA-treated cancer cells.
Cryopreserved Human Natural Killer Cells Exhibit Potent Antitumor Efficacy against Orthotopic Pancreatic Cancer through Efficient Tumor-Homing and Cytolytic Ability
Authors: Oh Eonju , Min Bokyung , Li Yan , Lian ChunYing , Hong JinWoo , Park Gyeong-min , Yang Bitna , Cho Sung , Hwang Yu , Yun Chae-Ok
Published: July 2019

Pancreatic cancer is known to be highly aggressive, and desmoplasia-induced accumulation of extracellular matrix (ECM), which is a hallmark of many pancreatic cancers, severely restricts the therapeutic efficacy of both immunotherapeutics and conventional chemotherapeutics due to the ECM functioning as a major physical barrier against permeation and penetration. In the case of cell-based immunotherapeutics, there are several other bottlenecks preventing translation into clinical use due to their biological nature; for example, poor availability of cell therapeutic in a readily usable form due to difficulties in production, handling, shipping, and storage. To address these challenges, we have isolated allogeneic natural killer (NK) cells from healthy donors and expanded them in vitro to generate cryopreserved stocks. These cryopreserved NK cells were thawed to evaluate their therapeutic efficacy against desmoplastic pancreatic tumors, ultimately aiming to develop a readily accessible and mass-producible off-the-shelf cell-based immunotherapeutic. The cultured NK cells post-thawing retained highly pure populations of activated NK cells that expressed various activating receptors and a chemokine receptor. Furthermore, systemic administration of NK cells induced greater in vivo tumor growth suppression when compared with gemcitabine, which is the standard chemotherapeutic used for pancreatic cancer treatment. The potent antitumor effect of NK cells was mediated by efficient tumor-homing ability and infiltration into desmoplastic tumor tissues. Moreover, the infiltration of NK cells led to strong induction of apoptosis, elevated expression of the antitumor cytokine interferon (IFN)-γ, and inhibited expression of the immunosuppressive transforming growth factor (TGF)-β in tumor tissues. Expanded and cryopreserved NK cells are strong candidates for future cell-mediated systemic immunotherapy against pancreatic cancer.
Co-Mn-Al Mixed Oxides Promoted by K for Direct NO Decomposition: Effect of Preparation Parameters
Authors: Pacultová Kateřina , Bílková Tereza , Klegova Anna , Karásková Kateřina , Fridrichová Dagmar , Jirátová Květa , Kiška Tomáš , Balabánová Jana , Koštejn Martin , Kotarba Andrzej , Kaspera Wojciech , Stelmachowski Paweł , Słowik Grzegorz , Obalová Lucie
Published: July 2019

Fundamental research on direct NO decomposition is still needed for the design of a sufficiently active, stable and selective catalyst. Co-based mixed oxides promoted by alkali metals are promising catalysts for direct NO decomposition, but which parameters play the key role in NO decomposition over mixed oxide catalysts? How do applied preparation conditions affect the obtained catalyst’s properties? Co4MnAlOx mixed oxides promoted by potassium calcined at various conditions were tested for direct NO decomposition with the aim to determine their activity, stability and selectivity. The catalysts were prepared by co-precipitation of the corresponding nitrates and subsequently promoted by KNO3. The catalysts were characterized by atomic absorption spectrometry (AAS)/inductive coupled plasma (ICP), X-ray photoelectron spectrometry (XPS), XRD, N2 physisorption, temperature programmed desorption of CO2 (TPD-CO2), temperature programmed reduction by hydrogen (TPR-H2), species-resolved thermal alkali desorption (SR-TAD), work function measurement and STEM. The preparation procedure affects physico-chemical properties of the catalysts, especially those that are associated with the potassium promoter presence. The addition of K is essential for catalytic activity, as it substantially affects the catalyst reducibility and basicity—key properties of a deNO catalyst. However, SR-TAD revealed that potassium migration, redistribution and volatilization are strongly dependent on the catalyst calcination temperature—higher calcination temperature leads to potassium stabilization. It also caused the formation of new phases and thus affected the main properties—SBET, crystallinity and residual potassium amount.
Modified Nimo Nanoparticles for Efficient Catalytic Hydrogen Generation from Hydrous Hydrazine
Authors: Liu Ying , Zhang Huan , Ma Cong , Sun Nan
Published: July 2019

Precious metal-free NiMoM (M = Pr2O3, Cu2O) catalysts have been synthesized through a simple coreduction method, without any surfactant or support material, and characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The resultant Pr2O3- or Cu2O-modified NiMo catalysts exhibit different structures, which is due to a difference in the synergistic effects of NiMo and the modifying elements. NiMoPr2O3 has an amorphous structure, with low crystallinity and uniform particle dispersion, while NiMo@Cu2O adopts the core–shell structure, where the core and shell are synergistic with each other to promote electron transfer efficiency. The support material-free nanocatalysts Ni9Mo1(Pr2O3)0.375 and Ni4Mo@Cu2O are both highly efficient compared with bimetallic NiMo catalysts, in terms of hydrogen generation from hydrous hydrazine (N2H4·H2O) at 343 K, with total turnover frequencies (TOFs) of 62 h−1 and 71.4 h−1, respectively. Their corresponding activation energies (Ea) were determined to be 43.24 kJ mol−1 and 46.47 kJ mol−1, respectively. This is the first report on the use of Pr-modified NiMo and core–shell NiMo@Cu2O catalysts, and these results may be used to promote the effective application of noble metal-free nanocatalysts for hydrogen production from hydrous hydrazine.
Arachidonic Acid Evokes an Increase in Intracellular Ca2+ Concentration and Nitric Oxide Production in Endothelial Cells from Human Brain Microcirculation
Authors: Berra-Romani Roberto , Faris Pawan , Negri Sharon , Botta Laura , Genova Tullio , Moccia Francesco
Published: July 2019

It has long been known that the conditionally essential polyunsaturated arachidonic acid (AA) regulates cerebral blood flow (CBF) through its metabolites prostaglandin E2 and epoxyeicosatrienoic acid, which act on vascular smooth muscle cells and pericytes to vasorelax cerebral microvessels. However, AA may also elicit endothelial nitric oxide (NO) release through an increase in intracellular Ca2+ concentration ([Ca2+]i). Herein, we adopted Ca2+ and NO imaging, combined with immunoblotting, to assess whether AA induces intracellular Ca2+ signals and NO release in the human brain microvascular endothelial cell line hCMEC/D3. AA caused a dose-dependent increase in [Ca2+]i that was mimicked by the not-metabolizable analogue, eicosatetraynoic acid. The Ca2+ response to AA was patterned by endoplasmic reticulum Ca2+ release through type 3 inositol-1,4,5-trisphosphate receptors, lysosomal Ca2+ mobilization through two-pore channels 1 and 2 (TPC1-2), and extracellular Ca2+ influx through transient receptor potential vanilloid 4 (TRPV4). In addition, AA-evoked Ca2+ signals resulted in robust NO release, but this signal was considerably delayed as compared to the accompanying Ca2+ wave and was essentially mediated by TPC1-2 and TRPV4. Overall, these data provide the first evidence that AA elicits Ca2+-dependent NO release from a human cerebrovascular endothelial cell line, but they seemingly rule out the possibility that this NO signal could acutely modulate neurovascular coupling.
Osteopontin in the Cerebrospinal Fluid of Patients with Severe Aneurysmal Subarachnoid Hemorrhage
Authors: Abate Maria Giulia , Moretto Lorenza , Licari Ilaria , Esposito Teresa , Capuano Lorenzo , Olivieri Carlo , Benech Arnaldo , Brucoli Matteo , Avanzi Gian Carlo , Cammarota Gianmaria , Dianzani Umberto , Clemente Nausicaa , Panzarasa Gabriele , Citerio Giuseppe , Carfagna Fabio , Cappellano Giuseppe , Della Corte Francesco , Vaschetto Rosanna
Published: July 2019

Aneurysmal subarachnoid hemorrhage (SAH) is associated with high morbidity and mortality. In SAH patients, plasma osteopontin (OPN) has been shown to independently predict poor outcome. The aim of the study is to investigate, in a selected population with severe SAH, OPN time course in cerebrospinal fluid (CSF) and plasma during the first week after aneurism rupture, and OPN prognostic value. We included 44 patients with the following criteria: (1) age 18 and 80 years, (2) diagnosis of SAH from cerebral aneurysm rupture, (3) insertion of external ventricular drain. Plasma and CSF were sampled at day 1, 4, and 8. OPN levels, in CSF and plasma, displayed a weak correlation on day 1 and were higher, in CSF, in all time points. Only in poor prognosis patients, OPN levels in CSF significantly increased at day 4 and day 8. Plasma OPN at day 1 and 4 was predictor of poor outcome. In conclusion, plasma and CSF OPN displays a weak correlation, on day 1. The higher levels of OPN found in the CSF compared to plasma, suggest OPN production within the CNS after SAH. Furthermore, plasma OPN, at day 1 and 4, seems to be an independent predictor of poor outcome.
First-Principles Investigations of Single Metal Atoms (Sc, Ti, V, Cr, Mn, and Ni) Embedded in Hexagonal Boron Nitride Nanosheets for the Catalysis of CO Oxidation
Authors: Liu Yi , Yang Li-Ming , Ganz Eric
Published: July 2019

We evaluated isolated transition metal atoms (Sc, Ti, V, Cr, Mn, and Ni) embedded in hexagonal-BN as novel single atom catalysts for CO oxidation. We predicted that embedded Ni atoms should have superior performance for this task. Ti, V, and Mn bind CO2 too strongly and so the reaction will not proceed smoothly. We studied the detailed reaction processes for Sc, Cr, and Ni. The Langmuir–Hinshelwood (LH), Eley–Rideal (ER), and the new termolecular Eley–Rideal (TER) processes for CO oxidation were investigated. Sc was not effective. Cr primarily used the ER process, although the barrier was relatively large at 1.30 eV. Ni was the best of the group, with a 0.44 eV barrier for LH, and a 0.47 eV barrier for TER. Therefore, we predicted that the LH and TER processes could operate at relatively low temperatures between 300 and 500 K.
A Phylogenomic Supertree of Birds
Authors: Kimball Rebecca T. , Oliveros Carl H. , Wang Ning , White Noor D. , Barker F. Keith , Field Daniel J. , Ksepka Daniel T. , Chesser R. Terry , Moyle Robert G. , Braun Michael J. , Brumfield Robb T. , Faircloth Brant C. , Smith Brian Tilston , Braun Edward L.
Published: July 2019

It has long been appreciated that analyses of genomic data (e.g., whole genome sequencing or sequence capture) have the potential to reveal the tree of life, but it remains challenging to move from sequence data to a clear understanding of evolutionary history, in part due to the computational challenges of phylogenetic estimation using genome-scale data. Supertree methods solve that challenge because they facilitate a divide-and-conquer approach for large-scale phylogeny inference by integrating smaller subtrees in a computationally efficient manner. Here, we combined information from sequence capture and whole-genome phylogenies using supertree methods. However, the available phylogenomic trees had limited overlap so we used taxon-rich (but not phylogenomic) megaphylogenies to weave them together. This allowed us to construct a phylogenomic supertree, with support values, that included 707 bird species (~7% of avian species diversity). We estimated branch lengths using mitochondrial sequence data and we used these branch lengths to estimate divergence times. Our time-calibrated supertree supports radiation of all three major avian clades (Palaeognathae, Galloanseres, and Neoaves) near the Cretaceous-Paleogene (K-Pg) boundary. The approach we used will permit the continued addition of taxa to this supertree as new phylogenomic data are published, and it could be applied to other taxa as well.
Effects of Mix Factors on the Mechanistic-Empirical Flexible Pavement Design
Authors: Islam Md Rashadul , Kalevela Sylvester A. , Nesselhauf Shelby K.
Published: July 2019

This study investigates the sensitivity of the mechanistic-empirical flexible pavement design performance parameters such as cracking, rutting, and smoothness to mix factors for 11 categories of hot-mix asphalt (HMA) mixtures. For each category of HMA mixture, the variations in the pavement performances for different effective binder content (Vbe), air void (Va), voids-in-mineral aggregates (VMA), voids-filled-with asphalt (VFA), and asphalt content (AC) are examined by the AASHTOWare Pavement Mechanistic-Empirical Design, simply the AASHTOWare software analysis. Five types of distresses: international roughness index (IRI), total rutting, rutting in the HMA layer, bottom-up fatigue cracking, and top-down longitudinal fatigue cracking are considered in the analysis. Results show that the prediction of distresses values after 20-year of service life using the AASHTOWare software may differ by up to 170% for different specimens of a certain mix design. All distresses, except rutting, increase in Va, VMA, and VFA. Rutting in HMA increases with an increase in VMA and VFA, and is insensitive to Vbe, Va, and AC in the study range of these parameters.
Do Crude Oil Prices Drive the Relationship between Stock Markets of Oil-Importing and Oil-Exporting Countries?
Authors: Youssef Manel , Mokni Khaled
Published: July 2019

The impact that oil market shocks have on stock markets of oil-related economies has several implications for both domestic and foreign investors. Thus, we investigate the role of the oil market in deriving the dynamic linkage between stock markets of oil-exporting and oil-importing countries. We employed a DCC-FIGARCH model to assess the dynamic relationship between these markets over the period between 2000 and 2018. Our findings report the following regularities: First, the oil-stock markets’ relationship and that between oil-importing and oil-exporting countries’ stock markets themselves is time-varying. Moreover, we note that the response of stock market returns to oil price changes in oil-importing countries changes is more pronounced than for oil-exporting countries during periods of turmoil. Second, the oil-stock dynamic correlations tend to change as a result of the origin of oil prices shocks stemming from the period of global turmoil or changes in the global business cycle. Third, oil prices significantly drive the relationship between oil-importing and oil-exporting countries’ stock markets in both high and low oil-stock correlation regimes.
The Nexus between Stock Returns of Oil Companies and Oil Price Fluctuations after Heavy Oil Upgrading: Toward Theoretical Progress
Authors: Sedighi Mojtaba , Mohammadi Majid , Farahani Fard Saeed , Sedighi Mehdi
Published: July 2019

This study attempts to discover the nexus between crude oil price fluctuation after heavy oil upgrading and stock returns of petroleum companies in the U.S. Stock Exchange for the years 2008 to 2018. One of the methods of upgrading heavy crude oil is to extract asphaltene from crude oil. Considering the Asphaltene Removal (AR) as a factor in the nexus between oil price and the stock market is an innovation in the literature of energy finance. Asphaltenes cause many problems in the petroleum industry, which increases the cost of oil production and reduces the financial efficiency of oil companies. The AR is certainly one of the significant matters of the oil industry and can affect the price of oil. Therefore, changes in the price of oil can influence the price of oil company stocks. Hence, changes in stock prices will certainly affect the stock returns of oil companies. In an effort to solve this puzzle, the four financial models were employed to explore the nexus between oil price fluctuations and stock returns. The analysis of the results demonstrated that the oil price fluctuations caused by the removal of asphaltenes influence the stock returns of petroleum companies. Eventually, the theoretical hypothesis was confirmed by considering the USA as a case study. The outcomes of this investigation are a theoretical progression in areas related to the petroleum industry and the stock market that could lead to the adoption of new investment policies in the petroleum industry including investing in new procedures to manage and decrease the costs and time of the AR process, which would result in the advancement of petroleum companies. In fact, we have introduced a modern investment strategy in the oil industry aimed at reducing oil production costs, improving financial statements and increasing the stock returns of petroleum companies. Eventually, we will present new investment policies in the oil industry that can lead to economic growth and development of financial markets especially stock market, derivatives market, futures exchange, commodities exchange, as well as bond market.
An Improved Model Predictive Torque Control for a Two-Level Inverter Fed Interior Permanent Magnet Synchronous Motor
Authors: Zhang Guozheng , Chen Chen , Gu Xin , Wang Zhiqiang , Li Xinmin
Published: July 2019

In conventional model predictive control, the dimensions of the control variables are different from each other, which makes adjusting the weighted factors in the cost function complicated. This issue can be solved by adopting the model predictive flux control. However, the performance of the electromagnetic torque is affected by the change of the cost function. A novel model predictive torque control of the interior permanent magnet synchronous motor is presented in this paper, and the cost function involving the excitation torque and reluctance torque is established. Combined with the model predictive flux control and discrete space vector modulation, the current ripple and torque ripple are reduced. The performance of torque under an overload condition is superior to model predictive flux control. The effectiveness of the proposed algorithm is verified by the simulation and experimental results.
Using Gaussian Mixture Models for Gesture Recognition During Haptically Guided Telemanipulation
Authors: Pérez-del-Pulgar Carlos J. , Smisek Jan , Rivas-Blanco Irene , Schiele Andre , Muñoz Victor F.
Published: July 2019

Haptic guidance is a promising method for assisting an operator in solving robotic remote operation tasks. It can be implemented through different methods, such as virtual fixtures, where a predefined trajectory is used to generate guidance forces, or interactive guidance, where sensor measurements are used to assist the operator in real-time. During the last years, the use of learning from demonstration (LfD) has been proposed to perform interactive guidance based on simple tasks that are usually composed of a single stage. However, it would be desirable to improve this approach to solve complex tasks composed of several stages or gestures. This paper extends the LfD approach for object telemanipulation where the task to be solved is divided into a set of gestures that need to be detected. Thus, each gesture is previously trained and encoded within a Gaussian mixture model using LfD, and stored in a gesture library. During telemanipulation, depending on the sensory information, the gesture that is being carried out is recognized using the same LfD trained model for haptic guidance. The method was experimentally verified in a teleoperated peg-in-hole insertion task. A KUKA LWR4+ lightweight robot was remotely controlled with a Sigma.7 haptic device with LfD-based shared control. Finally, a comparison was carried out to evaluate the performance of Gaussian mixture models with a well-established gesture recognition method, continuous hidden Markov models, for the same task. Results show that the Gaussian mixture models (GMM)-based method slightly improves the success rate, with lower training and recognition processing times.
A Simple and Robust Shock-Capturing Approach for Discontinuous Galerkin Discretizations
Authors: Choi Jae Hwan , Alonso Juan J. , van der Weide Edwin
Published: July 2019

The discontinuous Galerkin (DG) method has become popular in Computational Fluid Dynamics mainly due to its ability to achieve high-order solution accuracy on arbitrary grids, its high arithmetic intensity (measured as the ratio of the number of floating point operations to memory references), and the use of a local stencil that makes scalable parallel solutions possible. Despite its advantages, several difficulties hinder widespread use of the DG method, especially in industrial applications. One of the major challenges remaining is the capturing of discontinuities in a robust and accurate way. In our previous work, we have proposed a simple shock detector to identify discontinuities within a flow solution. The detector only utilizes local information to sense a shock/discontinuity ensuring that one of the key advantages of DG methods, their data locality, is not lost in transonic and supersonic flows. In this work, we reexamine the shock detector capabilities to distinguish between smooth and discontinuous solutions. Furthermore, we optimize the functional relationships between the shock detector and the filter strength, and present it in detail for others to use. By utilizing the shock detector and the corresponding filtering-strength relationships, one can robustly and accurately capture discontinuities ranging from very weak to strong shocks. Our method is demonstrated in a number of two-dimensional canonical examples.
Arbuscular Mycorrhizal Fungi Effectively Enhances the Growth of Gleditsia sinensis Lam. Seedlings under Greenhouse Conditions
Authors: Wang Jinping , Zhong Huini , Zhu Lingjun , Yuan Yingdan , Xu Linhao , Wang G. Geoff , Zhai Lu , Yang Lu , Zhang Jinchi
Published: July 2019

The Chinese honey locust tree Gleditsia sinensis Lam. (Fabaceae) is a precious ecological and economic tree species that has wide-ranging usage. However, knowledge regarding seedling cultivation (especially the use of arbuscular mycorrhizal fungi (AMF)) is scarce, which limits the developent of Gleditsia plantations. A pot experiment was carried out under greenhouse conditions to estimate the effects of three AMF strains (Funneliformis mosseae 1, Funneliformis mosseae 2, and Diversispora tortuosa) on the growth, photosynthetic rate, and nutrient content of G. sinensis seedlings. Results showed that the growth parameters (seedling height, basal diameter, dry biomass) of the seedlings were significantly increased by each of the three AMF strains, associated with high root colonization rates (greater than 75%). Chlorophyll concentrations and photosynthetic rates were also increased by AMF, and phosphorus (P), and potassium (K) content in the three organs (leaf, stem, and root), and nitrogen (N) content in the leaf and stem of arbuscular mycorrhizal (AM) seedlings were significantly higher than in non-AM seedlings. Mycorrhizal dependency of the AM seedlings was greater than 350%, and significantly correlated with the increased P and K content in all three organs and increased N content in the leaf and stem. Positive effects of F. mosseae on growth and the nutrient content of seedlings were higher than those of D. tortuosa, but no significant different effects on G. sinensis seedlings were observed between the two strains of F. mosseae. Hence, growth of G. sinensis seedlings was effectively enhanced by AMF, with F. mosseae being more suitable for the inoculation of G. sinensis seedlings. These results indicate that arbuscular mycorrhization is beneficial for the growth of young G. sinensis plants. Further research is needed to determine whether the effects can be reproduced in a forest situation.
The Role of Traditional Livelihood Practices and Local Ethnobotanical Knowledge in Mitigating Chestnut Disease and Pest Severity in Turkey
Authors: Wall Jeffrey , Köse Coşkun , Köse Nesibe , Okan Taner , Aksoy Elif Başak , Jarvis Devra , Allred Shorna
Published: July 2019

The European chestnut population is enduring multiple compounding exotic pest and disease outbreaks across Turkey. The deeply held value of the chestnut species for the Turkish public is reflected in substantial government conservation programming. Chestnut is predominantly found on state land managed by Turkey’s General Directorate of Forestry (GDF), which generally upholds restrictive policies for chestnut-related livelihood practices other than nut collection and beehive placement. Such policies are justified by a government position that human activities and presence is likely to worsen disease dynamics. Conversely, a growing body of research findings testify that small-scale livelihood practices maintain biological diversity and, furthermore, that this traditional maintenance of diversity has been correlated with decreased pathogen pressure within agroecosystems. However, few studies have investigated this phenomenon in the context of agroforestry systems. At a global ecological moment of increasingly pervasive and severe exotic forest pathogen impact, this paper investigates the influence of diverse small-scale livelihood practices and knowledge on chestnut tree health across the highly heterogenous geography of Turkey. We conducted ethnobotanical questionnaires with 96 chestnut-utilizing households, and chestnut tree health evaluations in georeferenced forest areas they identified, throughout Turkey’s Black Sea, Marmara, and Aegean regions. Using data from 1500 trees, we characterized the effects of subsequently recorded environmental, physiological, and anthropogenic factors on tree health using multiple correspondence analysis (MCA), multiple factor analysis (MFA), and mixed models. Our results show that the traditional human management of tree physiology and ecology has a significant positive effect on tree health, especially through the acts of grafting and culling as well as the maintenance of diversity. We argue that conceptualizing such livelihood systems as human niche construction and maintenance can help forest management agencies to better understand and conserve valuable landscapes, even in increasingly common periods of severe pathogenic pressure.
Reforesting Appalachian Surface Mines from Seed: A Five-Year Black Walnut Pilot Study
Authors: Hall Sarah L. , Barton Christopher D. , Sena Kenton L. , Angel Patrick
Published: July 2019

Research Highlights: We found promising success for black walnut (Juglans nigra L.) planted on a legacy surface mine. Our results indicate that direct seeding can be an effective restoration method, and that shelters may not be needed. Background and Objectives: Reforestation in the Appalachian coalfields has primarily relied on the planting of nursery stock late in the dormant season. This study examined the use of direct seeding during the fall, a practice that, if successful, could both reduce costs of planting and open up a new season for reforestation planting. Black walnut is of particular value for wildlife habitats, timber value, and even human nutrition. In addition, it normally occurs in diverse forests with rich soils of the region. Therefore, establishment on previously surface-mined lands may indicate a positive successional trajectory and resilience. Materials and Methods: This study took place in eastern Kentucky, USA, on a site that was surface mined from 1996 to 2000 and subsequently reclaimed as a wildlife habitat. In 2010, the site was decompacted according to the Forestry Reclamation Approach (FRA) by deep ripping with a bulldozer, and in November 2011, a 2 × 2 factorial experiment was initiated to compare the growth of walnut trees planted either by seed or as one-year seedlings, and either with or without tree shelters. Each treatment (four total: Unsheltered Seedling, Sheltered Seedling, Unsheltered Seed, and Sheltered Seed) had three replicate plots of 17 × 9 m, with 50 seeds or seedlings planted per plot. Measurements (survival, height, diameter, and volume) were made in 2012, 2013, and 2016. Effects of planting type and shelter presence, as well as their interaction, were analyzed using linear mixed models. Results: Planting type was significant for all measurements in the first two years (seedlings > seed), but this difference was largely diminished by 2016. There was a significant interaction of the two main effects, such that shelters benefited (or did not affect) those trees planted as seedlings, but hindered those planted from seed.
Architecting Software for the Internet of Thing Based Systems
Authors: Alreshidi Abdulrahman , Ahmad Aakash
Published: July 2019

Context—Internet of Thing (IoT) based systems support any-time/place computations by interconnecting humans, systems, services, devices, and things that enabling autonomous systems to shape-up digitized societies. Software architecture, as the blue-print of software-intensive systems, abstracts the complexities of modeling, design, development, and evolution phases of a software to engineer complex IoT driven systems effectively and efficiently. Objectives and Method—Research and development efforts are required to exploit architectural principle and practices to design and develop IoT systems to go beyond the state-of-the-art for IoTs. The objectives of this research are to empirically investigate and systematically classify the state-of-the-art on architecting IoT based software. We have used the Evidence Based Software Engineering (EBSE) method to conduct a mapping study of the existing IoT solutions by investigating 88 qualitatively selected studies. Results and Implications—The results of the mapping study highlight various research themes that exploit software architecture models to develop IoT systems. The identified research themes include, but are not limited to, cloud-based software ecosystems, software defined networking, autonomous, and adaptive software and agent-based systems that IoTs drive. The mapping study suggests that futuristic research on architecting IoT software is focused on architectural languages and patterns that support reusability, automation, and human decision support to develop and dynamically adapt IoT software. The mapping study represents a concentrated knowledge regarding architectural principle and practices to facilitate knowledge transfer—benefiting researchers and practitioners—on the role of software architecture for IoT systems.
Signatures of the Crypto-Currency Market Decoupling from the Forex
Authors: Drożdż Stanisław , Minati Ludovico , Oświȩcimka Paweł , Stanuszek Marek , Wa̧torek Marcin
Published: July 2019

Based on the high-frequency recordings from Kraken, a cryptocurrency exchange and professional trading platform that aims to bring Bitcoin and other cryptocurrencies into the mainstream, the multiscale cross-correlations involving the Bitcoin (BTC), Ethereum (ETH), Euro (EUR) and US dollar (USD) are studied over the period between 1 July 2016 and 31 December 2018. It is shown that the multiscaling characteristics of the exchange rate fluctuations related to the cryptocurrency market approach those of the Forex. This, in particular, applies to the BTC/ETH exchange rate, whose Hurst exponent by the end of 2018 started approaching the value of 0.5, which is characteristic of the mature world markets. Furthermore, the BTC/ETH direct exchange rate has already developed multifractality, which manifests itself via broad singularity spectra. A particularly significant result is that the measures applied for detecting cross-correlations between the dynamics of the BTC/ETH and EUR/USD exchange rates do not show any noticeable relationships. This could be taken as an indication that the cryptocurrency market has begun decoupling itself from the Forex.