bluuebunny/crossref_metadata_2025 huggingface dataset:
Design, Synthesis and Anti-Platelet Aggregation Activity Study of Ginkgolide-1,2,3-triazole Derivatives
Authors: Cui Jian , Hu Le’An , Shi Wei , Cui Guozhen , Zhang Xumu , Zhang Qing-Wen
Published: June 2019

Ginkgolides are the major active component of Ginkgo biloba for inhibition of platelet activating factor receptor. An azide-alkyne Huisgen cycloaddition reaction was used to introduce a triazole nucleus into the target ginkgolide molecules. A series of ginkgolide-1,2,3-triazole conjugates with varied functional groups including benzyl, phenyl and heterocycle moieties was thus synthesized. Many of the designed derivatives showed potent antiplatelet aggregation activities with IC50 values of 5~21 nM.
Datura Metel L. Ameliorates Imiquimod-Induced Psoriasis-Like Dermatitis and Inhibits Inflammatory Cytokines Production through TLR7/8–MyD88–NF-κB–NLRP3 Inflammasome Pathway
Authors: Yang Bing-You , Cheng Yan-Gang , Liu Yan , Liu Yuan , Tan Jin-Yan , Guan Wei , Guo Shuang , Kuang Hai-Xue
Published: June 2019

Background: Psoriasis is a chronic, immune-mediated inflammatory skin disease, and the inflammatory response plays an important role in its development and progression. Datura metel L. is a traditional Chinese medicine that exhibited a significant therapeutic effect on psoriasis in our previous study due to its remarkable anti-inflammatory effect. Meanwhile, the mechanism underlying its effects on psoriasis is still unclear. Methods: An imiquimod-induced psoriasis-like dermatitis mouse model was constructed to evaluate the protective effect of the effective part of Datura metel L. (EPD), which was verified by evaluations of the Psoriasis Area and Severity Index (PASI) score. Hematoxylin and eosin (H&E) staining, immunohistochemical examination, enzyme-linked immunosorbent assay (ELISA), and Western blot were used to measure the inflammatory cytokines and the protein expression associated with the Toll-like receptor 7– myeloid differentiation primary response gene 88–nuclear Factor-κB–nucleotide-binding oligomerization domain (Nod)-like receptor family pyrin domain-containing 3 (TLR7/8–MyD88–NF-κB–NLRP3) inflammasome pathway. Results: EPD significantly decreased the PASI, reduced epidermal thickness, and decreased the proliferation and differentiation of epidermal cells in psoriasis-like dermatitis C57BL/6 mice induced by imiquimod (IMQ). Furthermore, EPD reduced the infiltration of CD3+ cells to psoriatic lesions, as well as ameliorated the elevations of intercellular adhesion molecule 1 (ICAM-1) and inhibited the production of imiquimod-induced inflammatory cytokines, including IL-1β, IL-2, IL-6, IL-10, IL-12, IL-17, IL-22, IL-23, tumor necrosis factor-α (TNF-α), monocyte chemotactic protein 1 (MCP-1), and interferon-γ (IFN-γ). Besides, EPD decreased the imiquimod-induced expression levels of TLR7, TLR8, TRAF6, MyD88, p-IKKα, p-IKBα, p-NF-κB, NLRP3, apoptosis-associated speck-like protein contained a caspase recruitment domain (ASC), cysteinyl aspartate specific proteinase 1 (caspase-1), and IL-1β. Conclusion: This study demonstrated that EPD exhibited a protective effect on an imiquimod-induced psoriasis mice model by inhibiting the inflammatory response, which might be ascribed to the inhibition of the TLR7/8–MyD88–NF-κb–NLRP3 inflammasome pathway.
Rapid, Refined, and Robust Method for Expression, Purification, and Characterization of Recombinant Human Amyloid beta 1-42
Authors: Prakash Priya , Lantz Travis C. , Jethava Krupal P. , Chopra Gaurav
Published: June 2019

Amyloid plaques found in the brains of Alzheimer’s disease patients primarily consists of amyloid beta 1-42 (Aβ42). Commercially, Aβ42 is synthesized using high-throughput peptide synthesizers resulting in the presence of impurities and the racemization of amino acids that affects its aggregation properties. Furthermore, the repeated purchase of even a small quantity (~1 mg) of commercial Aβ42 can be expensive for academic researchers. Here, we describe a detailed methodology for robust expression of recombinant human Aβ(M1-42) in Rosetta(DE3)pLysS and BL21(DE3)pLysS competent E. coli using standard molecular biology techniques with refined and rapid one-step analytical purification techniques. The peptide is isolated and purified from transformed cells using an optimized reverse-phase high-performance liquid chromatography (HPLC) protocol with commonly available C18 columns, yielding high amounts of peptide (~15–20 mg per 1 L culture) within a short period of time. The recombinant human Aβ(M1-42) forms characteristic aggregates similar to synthetic Aβ42 aggregates as verified by western blotting and atomic force microscopy to warrant future biological use. Our rapid, refined, and robust technique produces pure recombinant human Aβ(M1-42) that may be used to synthesize chemical probes and in several downstream in vitro and in vivo assays to facilitate Alzheimer’s disease research.
Comparison of Different Polarization Sensitive Second Harmonic Generation Imaging Techniques
Authors: Alizadeh Mehdi , Ghotbi Masood , Loza-Alvarez Pablo , Merino David
Published: June 2019

Polarization sensitive second harmonic generation (pSHG) microscopy is an imaging technique able to provide, in a non-invasive manner, information related to the molecular structure of second harmonic generation (SHG) active structures, many of which are commonly found in biological tissue. The process of acquiring this information by means of pSHG microscopy requires a scan of the sample using different polarizations of the excitation beam. This process can take considerable time in comparison with the dynamics of in vivo processes. Fortunately, single scan polarization sensitive second harmonic generation (SS-pSHG) microscopy has also been reported, and is able to generate the same information at a faster speed compared to pSHG. In this paper, the orientation of second harmonic active supramolecular assemblies in starch granules is obtained on by means of pSHG and SS-pSHG. These results are compared in the forward and backward directions, showing a good agreement in both techniques. This paper shows for the first time, to the best of the authors’ knowledge, data acquired using both techniques over the exact same sample and image plane, so that they can be compared pixel-to-pixel.
Gold Nanoparticle-Based Colorimetric Strategies for Chemical and Biological Sensing Applications
Authors: Chang Chia-Chen , Chen Chie-Pein , Wu Tzu-Heng , Yang Ching-Hsu , Lin Chii-Wann , Chen Chen-Yu
Published: June 2019

Gold nanoparticles are popularly used in biological and chemical sensors and their applications owing to their fascinating chemical, optical, and catalytic properties. Particularly, the use of gold nanoparticles is widespread in colorimetric assays because of their simple, cost-effective fabrication, and ease of use. More importantly, the gold nanoparticle sensor response is a visual change in color, which allows easy interpretation of results. Therefore, many studies of gold nanoparticle-based colorimetric methods have been reported, and some review articles published over the past years. Most reviews focus exclusively on a single gold nanoparticle-based colorimetric technique for one analyte of interest. In this review, we focus on the current developments in different colorimetric assay designs for the sensing of various chemical and biological samples. We summarize and classify the sensing strategies and mechanism analyses of gold nanoparticle-based detection. Additionally, typical examples of recently developed gold nanoparticle-based colorimetric methods and their applications in the detection of various analytes are presented and discussed comprehensively.
Negative Differential Conductance Assisted by Optical Fields in a Single Quantum Dot with Ferromagnetic Electrodes
Authors: Liu Weici , Wang Faqiang , Tang Zhilie , Liang Ruisheng
Published: June 2019

In a single quantum dot (QD) system connected with ferromagnetic electrodes, the electron transport properties, assisted by the thermal and Fock state optical fields, are theoretically studied by the Keldysh nonequilibrium Green’s function approach. The results show that the evolution properties of the density of state and tunneling current assisted by the Fock state optical field, are quite different from those of the thermal state. The photon sideband shift decreases monotonously with the increase in the electron–photon coupling strength for the case of the thermal state, while the shift is oscillatory for the case of the Fock state. Negative differential conductance (NDC) appears obviously in a QD system contacted with parallel (P) and antiparallel (AP) magnetization alignment of the ferromagnetic electrode leads, assisted by the Fock state optical field in a wide range of electron–photon interaction parameters. Evident NDC usually only arises in an AP configuration QD system assisted by the thermal state optical field. The results have the potential to introduce a new way to actively manipulate and control the single-electron tunneling transport on a QD system by the quantum states of the optical field.
Near-Infrared Optical Modulation for Ultrashort Pulse Generation Employing Indium Monosulfide (InS) Two-Dimensional Semiconductor Nanocrystals
Authors: Wang Tao , Wang Jin , Wu Jian , Ma Pengfei , Su Rongtao , Ma Yanxing , Zhou Pu
Published: June 2019

In recent years, metal chalcogenide nanomaterials have received much attention in the field of ultrafast lasers due to their unique band-gap characteristic and excellent optical properties. In this work, two-dimensional (2D) indium monosulfide (InS) nanosheets were synthesized through a modified liquid-phase exfoliation method. In addition, a film-type InS-polyvinyl alcohol (PVA) saturable absorber (SA) was prepared as an optical modulator to generate ultrashort pulses. The nonlinear properties of the InS-PVA SA were systematically investigated. The modulation depth and saturation intensity of the InS-SA were 5.7% and 6.79 MW/cm2, respectively. By employing this InS-PVA SA, a stable, passively mode-locked Yb-doped fiber laser was demonstrated. At the fundamental frequency, the laser operated at 1.02 MHz, with a pulse width of 486.7 ps, and the maximum output power was 1.91 mW. By adjusting the polarization states in the cavity, harmonic mode-locked phenomena were also observed. To our knowledge, this is the first time an ultrashort pulse output based on InS has been achieved. The experimental findings indicate that InS is a viable candidate in the field of ultrafast lasers due to its excellent saturable absorption characteristics, which thereby promotes the ultrafast optical applications of InX (X = S, Se, and Te) and expands the category of new SAs.
Knockdown of microRNA-135b in Mammary Carcinoma by Targeted Nanodiamonds: Potentials and Pitfalls of In Vivo Applications
Authors: Křivohlavá Romana , Neuhӧferová Eva , Jakobsen Katrine Q. , Benson Veronika
Published: June 2019

Nanodiamonds (ND) serve as RNA carriers with potential for in vivo application. ND coatings and their administration strategy significantly change their fate, toxicity, and effectivity within a multicellular system. Our goal was to develop multiple ND coating for effective RNA delivery in vivo. Our final complex (NDA135b) consisted of ND, polymer, antisense RNA, and transferrin. We aimed (i) to assess if a tumor-specific coating promotes NDA135b tumor accumulation and effective inhibition of oncogenic microRNA-135b and (ii) to outline off-targets and immune cell interactions. First, we tested NDA135b toxicity and effectivity in tumorospheres co-cultured with immune cells ex vivo. We found NDA135b to target tumor cells, but it binds also to granulocytes. Then, we followed with NDA135b intravenous and intratumoral applications in tumor-bearing animals in vivo. Application of NDA135b in vivo led to the effective knockdown of microRNA-135b in tumor tissue regardless administration. Only intravenous application resulted in NDA135b circulation in peripheral blood and urine and the decreased granularity of splenocytes. Our data show that localized intratumoral application of NDA135b represents a suitable and safe approach for in vivo application of nanodiamond-based constructs. Systemic intravenous application led to an interaction of NDA135b with bio-interface, and needs further examination regarding its safety.
Understanding of Nanophase Separation and Hydrophilic Morphology in Nafion and SPEEK Membranes: A Combined Experimental and Theoretical Studies
Authors: Wang Rujie , Liu Shanshan , Wang Lidong , Li Ming , Gao Chong
Published: June 2019

The understanding of the relationship between the chemical structure and the hydrophilic structure is crucial for the designing of high-performance PEMs. Comparative studies in typical Nafion and sulfonated poly (ether ether ketone) (SPEEK) were performed using a combined experimental and theoretical method. SPEEK showed suppressed fuel crossover and good mechanical property but low water uptake, weak phase separation, and inadequate proton conductivity. Molecular dynamics (MD) simulation approaches were employed to get a molecular-level understanding of the structure–property relationship of SPEEK and Nafion membranes. In SPEEK membranes, the local aggregation of hydrophilic clusters is worse, and much stronger electrostatic interaction between Os–Hh was verified, resulting in less delocalized free H3O+ and much lower DH3O+. In addition, the probability of H2O–H3O+ association varied with water content. Particularly, SPEEK exhibited much lower H9O4+ probability at various relative water contents, leading to lower structural diffusivity than Nafion. Eventually, SPEEK possessed low vehicular and structural diffusivities, which resulted in a low proton conductivity. The results indicated that the structure of hydrated hydronium complexes would deform to adapt the confining hydrophilic channels. The confinement effect on diffusion of H2O and H3O+ is influenced by the water content and the hydrophilic morphologies. This study provided a new insight into the exploration of high-performance membranes in fuel cell.
Fabrication of Superhydrophobic Silicone Rubber with Periodic Micro/Nano-Suction Cup Structure by ArF Excimer Laser-Induced Photodissociation
Authors: Okoshi Masayuki
Published: June 2019

A 193-nm ArF excimer laser was used to induce the photodissociation of Si–O bonds of silicone rubber in order to fabricate a periodic micro/nano-suction cup silicone structure, approximately 1 μm in diameter and 2 μm in height at regular intervals of 2.5 μm. The laser was focused on Al-coated silicone rubber by each silica glass microsphere 2.5 μm in diameter, which covered the entire surface of the silicone rubber. The silicone rubber underneath each microsphere photochemically swelled after laser-ablating the coated Al to limit the diameter of the swelling. Simultaneously, the coated Al was able to adjust the focal point to the surface of the silicone rubber to form a hole approximately 500 nm in diameter, centered at the swollen silicone. The dependences of the thickness of the coated-Al and the laser pulse number are discussed, based on the observations of a scanning electron microscope (SEM) and an atomic force microscope (AFM). The superhydrophobic property of the fabricated micro/nano-suction cup structure was successfully found.
Mediterranean Diet Adherence is Associated with Lower Prevalence of Functional Gastrointestinal Disorders in Children and Adolescents
Authors: Agakidis Charalampos , Kotzakioulafi Evangelia , Petridis Dimitrios , Apostolidou Konstantina , Karagiozoglou-Lampoudi Thomai
Published: June 2019

Dietary patterns may have a role in the prevention of functional gastrointestinal disorders (FGIDs). The current study aimed at examining the association between FGIDs and adherence to the Mediterranean diet (MD) among elementary school children (ESC), as well as high school students (HSS). In a prospective cohort study, data from 1116 subjects (387 ESC and 448 HSS) aged 6–18 years were collected. FGID identification was based on the Questionnaire on Pediatric Gastrointestinal Symptoms-Rome III (QPGS-RIII). Adherence to the MD was assessed using the KIDMED Index. Full data were available on 835/1116 questionnaires. Based on Rome III criteria, 184/835 participants (22%) were identified with FGID (122 (66%) with functional constipation (FC)). The prevalence of FGIDs (p = 0.001) was significantly higher in HSS (13–18 years). The KIDMED score in the cohort was 5.7 ± 2.5. Subjects with FGIDs demonstrated a lower KIDMED score compared to the non-FGID group, both in the cohort, as well as in the ESC and HSS subgroups (FGID vs. non-FGID: p = 0.001, p = 0.007, and p = 0.032, respectively). Multivariate analysis highlighted the KIDMED score as a significant predictor of FGIDs and FC after controlling for the age subgroups. We conclude that good adherence to the MD is associated to lower prevalence of FGIDs, while adolescents display a significantly higher prevalence of FGIDs compared to children.
Food Addiction Symptoms and Amygdala Response in Fasted and Fed States
Authors: Pursey Kirrilly M. , Contreras-Rodriguez Oren , Collins Clare E. , Stanwell Peter , Burrows Tracy L.
Published: June 2019

Few studies have investigated the underlying neural substrates of food addiction (FA) in humans using a recognised assessment tool. In addition, no studies have investigated subregions of the amygdala (basolateral (BLA) and central amygdala), which have been linked to reward-seeking behaviours, susceptibility to weight gain, and promoting appetitive behaviours, in the context of FA. This pilot study aimed to explore the association between FA symptoms and activation in the BLA and central amygdala via functional magnetic resonance imaging (fMRI), in response to visual food cues in fasted and fed states. Females (n = 12) aged 18–35 years completed two fMRI scans (fasted and fed) while viewing high-calorie food images and low-calorie food images. Food addiction symptoms were assessed using the Yale Food Addiction Scale. Associations between FA symptoms and activation of the BLA and central amygdala were tested using bilateral masks and small-volume correction procedures in multiple regression models, controlling for BMI. Participants were 24.1 ± 2.6 years, with mean BMI of 27.4 ± 5.0 kg/m2 and FA symptom score of 4.1 ± 2.2. A significant positive association was identified between FA symptoms and higher activation of the left BLA to high-calorie versus low-calorie foods in the fasted session, but not the fed session. There were no significant associations with the central amygdala in either session. This exploratory study provides pilot data to inform future studies investigating the neural mechanisms underlying FA.
Vitamin D Supplementation and Post-Stroke Rehabilitation: A Randomized, Double-Blind, Placebo-Controlled Trial
Authors: Momosaki Ryo , Abo Masahiro , Urashima Mitsuyoshi
Published: June 2019

Low vitamin D levels are associated with poorer outcomes after stroke. However, it is not clear whether post-stroke vitamin D supplementation can improve these outcomes. In this study, we investigated the effects of vitamin D supplementation on outcomes in hospitalized patients undergoing rehabilitation after acute stroke. A multicenter, randomized, controlled, double-blind, parallel-group trial was conducted from January 2012 through July 2017. One hundred patients admitted to a convalescent rehabilitation ward after having an acute stroke were randomized, and each one received either vitamin D3 (2000 IU/day) or a placebo. The primary outcome was a gain in the Barthel Index scores at week 8. Secondary outcomes were seen in Barthel Index efficiency, hand grip strength, and calf circumference at week 8. Ninety-seven patients completed the study. There were no significant differences in the demographic characteristics between the groups. The mean (±standard deviation) gain in the Barthel Index score was 19.0 ± 14.8 in the supplementation group and 19.5 ± 13.1 in the placebo group (p = 0.88). The Barthel Index efficiency was 0.32 ± 0.31 in the supplementation group and 0.28 ± 0.21 in the placebo group (p = 0.38). There were no between-group differences in the other secondary outcomes. Our findings suggest that oral vitamin D3 supplementation does not improve rehabilitation outcomes after acute stroke.
Simultaneous Recovery of Matrix and Fiber in Carbon Reinforced Composites through a Diels–Alder Solvolysis Process
Authors: Fortunato Giovanni , Anghileri Luca , Griffini Gianmarco , Turri Stefano
Published: June 2019

Efficient and comprehensive recycling of fiber-reinforced thermosets is particularly challenging, since the irreversible degradation of the matrix component is necessary in order to separate the fiber component in high purity. In this work, a new approach to fully recyclable thermoset composites is presented, based on the thermal reversibility of an epoxy-based polymer network, crosslinked through Diels–Alder (DA) chemistry. Carbon fiber composites, fabricated by compression molding, were efficiently recycled through a simple solvolysis procedure in common solvents, under mild conditions, with no catalysts. Specifically, the purity of reclaimed fibers, assessed by thermogravimetric analysis and scanning electron microscopy, was very high (>95%) and allowed successful reprocessing into second generation composites. Moreover, the dissolved matrix residues were directly employed to prepare smart, thermally healable coatings. Overall, DA chemistry has been shown to provide a convenient strategy towards circular economy of thermoset composites.
Development of Large-Scale Stopped-Flow Technique and its Application in Elucidation of Initial Ziegler–Natta Olefin Polymerization Kinetics
Authors: Thakur Ashutosh , Wada Toru , Chammingkwan Patchanee , Terano Minoru , Taniike Toshiaki
Published: June 2019

The stopped-flow (SF) technique has been extensively applied to study Ziegler–Natta (ZN) olefin polymerization kinetics within an extremely short period (typically <0.2 s) for understanding the nature of the active sites as well as the polymerization mechanisms through microstructure analyses of obtained polymers. In spite of its great applicability, a small amount of polymer that is yielded in a short-time polymerization has been a major bottleneck for polymer characterizations. In order to overcome this limitation, a large-scale SF (LSF) system has been developed, which offers stable and scalable polymerization over an expanded time range from a few tens milliseconds to several seconds. The scalability of the LSF technique has been further improved by introducing a new quenching protocol. With these advantages, the LSF technique has been effectively applied to address several unknown issues in ZN catalysis, such as the role of physical and chemical transformations of a catalyst on the initial polymerization kinetics, and regiochemistry of ZN propylene polymerization. Here, we review the development of the LSF technique and recent efforts for understanding heterogeneous ZN olefin polymerization catalysis with this new system.
Civil Religion as Myth, Not History
Authors: Danielson Leilah
Published: June 2019

This article draws upon recent historiography to critique the concept of “civil religion”, and argues that it should be replaced by nationalism. Its central point is that there is indeed a dominant language of American nationalism and one that has largely reflected the culture of the Anglo-Protestant majority, but that it has always been contested and that it has changed over time. Civil religion, by contrast, is a far more slippery concept that elides questions of power, identity, and belonging that nationalism places at the center of inquiry.
Global Earthquake Response with Imaging Geodesy: Recent Examples from the USGS NEIC
Authors: Barnhart William D. , Hayes Gavin P. , Wald David J.
Published: June 2019

The U.S. Geological Survey National Earthquake Information Center leads real-time efforts to provide rapid and accurate assessments of the impacts of global earthquakes, including estimates of ground shaking, ground failure, and the resulting human impacts. These efforts primarily rely on analysis of the seismic wavefield to characterize the source of the earthquake, which in turn informs a suite of disaster response products such as ShakeMap and PAGER. In recent years, the proliferation of rapidly acquired and openly available in-situ and remotely sensed geodetic observations has opened new avenues for responding to earthquakes around the world in the days following significant events. Geodetic observations, particularly from interferometric synthetic aperture radar (InSAR) and satellite optical imagery, provide a means to robustly constrain the dimensions and spatial complexity of earthquakes beyond what is typically possible with seismic observations alone. Here, we document recent cases where geodetic observations contributed important information to earthquake response efforts—from informing and validating seismically-derived source models to independently constraining earthquake impact products—and the conditions under which geodetic observations improve earthquake response products. We use examples from the 2013 Mw7.7 Baluchistan, Pakistan, 2014 Mw6.0 Napa, California, 2015 Mw7.8 Gorkha, Nepal, and 2018 Mw7.5 Palu, Indonesia earthquakes to highlight the varying ways geodetic observations have contributed to earthquake response efforts at the NEIC. We additionally provide a synopsis of the workflows implemented for geodetic earthquake response. As remote sensing geodetic observations become increasingly available and the frequency of satellite acquisitions continues to increase, operational earthquake geodetic imaging stands to make critical contributions to natural disaster response efforts around the world.
A Novel Relational-Based Transductive Transfer Learning Method for PolSAR Images via Time-Series Clustering
Authors: Qin Xingli , Yang Jie , Li Pingxiang , Sun Weidong , Liu Wei
Published: June 2019

The combination of transfer learning and remote sensing image processing technology can effectively improve the automation level of image information extraction from a remote sensing time series. However, in the processing of polarimetric synthetic aperture radar (PolSAR) time-series images, the existing transfer learning methods often cannot make full use of the time-series information of the images, relying too much on the labeled samples in the target domain. Furthermore, the speckle noise inherent in synthetic aperture radar (SAR) imagery aggravates the difficulty of the manual selection of labeled samples, so these methods have difficulty in meeting the processing requirements of large data volumes and high efficiency. In lieu of these problems and the spatio-temporal relational knowledge of objects in time-series images, this paper introduces the theory of time-series clustering and proposes a new three-phase time-series clustering algorithm. Due to the full use of the inherent characteristics of the PolSAR images, this algorithm can accurately transfer the labels of the source domain samples to those samples that have not changed in the whole time series without relying on the target domain labeled samples, so as to realize transductive sample label transfer for PolSAR time-series images. Experiments were carried out using three different sets of PolSAR time-series images and the proposed method was compared with two of the existing methods. The experimental results showed that the transfer precision of the proposed method reaches a high level with different data and different objects and it performs significantly better than the existing methods. With strong reliability and practicability, the proposed method can provide a new solution for the rapid information extraction of remote sensing image time series.
The Pan-and-Tilt Hyperspectral Radiometer System (PANTHYR) for Autonomous Satellite Validation Measurements—Prototype Design and Testing
Authors: Vansteenwegen Dieter , Ruddick Kevin , Cattrijsse André , Vanhellemont Quinten , Beck Matthew
Published: June 2019

This paper describes a system, named “pan-and-tilt hyperspectral radiometer system” (PANTHYR) that is designed for autonomous measurement of hyperspectral water reflectance. The system is suitable for deployment in diverse locations (including offshore platforms) for the validation of water reflectance derived from any satellite mission with visible and/or near-infrared spectral bands (400–900 nm). Key user requirements include reliable autonomous operation at remote sites without grid power or cabled internet and only limited maintenance (1–2 times per year), flexible zenith and azimuth pointing, modularity to adapt to future evolution of components and different sites (power, data transmission, and mounting possibilities), and moderate hardware acquisition cost. PANTHYR consists of two commercial off-the-shelf (COTS) hyperspectral radiometers, mounted on a COTS pan-and-tilt pointing system, controlled by a single-board-computer and associated custom-designed electronics which provide power, pointing instructions, and data archiving and transmission. The variable zenith pointing improves protection of sensors which are parked downward when not measuring, and it allows for use of a single radiance sensor for both sky and water viewing. The latter gives cost reduction for radiometer purchase, as well as reduction of uncertainties associated with radiometer spectral and radiometric differences for comparable two-radiance-sensor systems. The system is designed so that hardware and software upgrades or changes are easy to implement. In this paper, the system design requirements and choices are described, including details of the electronics, hardware, and software. A prototype test on the Acqua Alta Oceanographic Tower (near Venice, Italy) is described, including comparison of the PANTHYR system data with two other established systems: the multispectral autonomous AERONET-OC data and a manually deployed three-sensor hyperspectral system. The test established that high-quality hyperspectral data for water reflectance can be acquired autonomously with this system. Lessons learned from the prototype testing are described, and the future perspectives for the hardware and software development are outlined.
Reconstruction of Ocean Color Data Using Machine Learning Techniques in Polar Regions: Focusing on Off Cape Hallett, Ross Sea
Authors: Park Jinku , Kim Jeong-Hoon , Kim Hyun-cheol , Kim Bong-Kuk , Bae Dukwon , Jo Young-Heon , Jo Naeun , Lee Sang Heon
Published: June 2019

The most problematic issue in the ocean color application is the presence of heavy clouds, especially in polar regions. For that reason, the demand for the ocean color application in polar regions is increased. As a way to overcome such issues, we conducted the reconstruction of the chlorophyll-a concentration (CHL) data using the machine learning-based models to raise the usability of CHL data. This analysis was first conducted on a regional scale and focused on the biologically-valued Cape Hallett, Ross Sea, Antarctica. Environmental factors and geographical information associated with phytoplankton dynamics were considered as predictors for the CHL reconstruction, which were obtained from cloud-free microwave and reanalysis data. As the machine learning models used in the present study, the ensemble-based models such as Random forest (RF) and Extremely randomized tree (ET) were selected with 10-fold cross-validation. As a result, both CHL reconstructions from the two models showed significant agreement with the standard satellite-derived CHL data. In addition, the reconstructed CHLs were close to the actual CHL value even where it was not observed by the satellites. However, there is a slight difference between the CHL reconstruction results from the RF and the ET, which is likely caused by the difference in the contribution of each predictor. In addition, we examined the variable importance for the CHL reconstruction quantitatively. As such, the sea surface and atmospheric temperature, and the photosynthetically available radiation have high contributions to the model developments. Mostly, geographic information appears to have a lower contribution relative to environmental predictors. Lastly, we estimated the partial dependences for the predictors for further study on the variable contribution and investigated the contributions to the CHL reconstruction with changes in the predictors.
Sensitivity Analysis Method for Spectral Band Adjustment between Hyperspectral Sensors: A Case Study Using the CLARREO Pathfinder and HISUI
Authors: Obata Kenta
Published: June 2019

The International Space Station has become the platform for deploying hyperspectral sensors covering the solar reflective spectral range for earth observation. Intercalibration of hyperspectral sensors plays a crucial role in evaluating/improving radiometric consistency. When intercalibrating between hyperspectral sensors, spectral band adjustment is required to mitigate the effects of differences between the relative spectral responses (RSRs) of the sensors. Errors in spectral parameters used in spectral band adjustment are propagated through to the adjustment results. The present study analytically approximated the uncertainty in the spectral band adjustment for evaluating the relative contributions of uncertainties in parameters associated with the exo-atmosphere, atmosphere, and surface to the total uncertainty. Numerical simulations using the derived equations were conducted to perform a sensitivity analysis for the case of the spectral band adjustment between the Climate Absolute Radiance and Refractivity Observatory (CLARREO) Pathfinder (CPF) and the Hyperspectral Imager Suite (HISUI). The results show that the effects of errors in the solar irradiance were greater than those of other sources of error, indicating that accurate estimates of atmospheric reflectances and tranismittances are not needed for spectral band adjustment between CPF and HISUI in the atmospheric windows. The accuracy of the analytical approximation was also evaluated in the simulations. The framework of the sensitivity analysis is applicable to other pairs of hyperspectral sensors.
Determining the Boundary and Probability of Surface Urban Heat Island Footprint Based on a Logistic Model
Authors: Qiao Zhi , Wu Chen , Zhao Dongqi , Xu Xinliang , Yang Jilin , Feng Li , Sun Zongyao , Liu Luo
Published: June 2019

Studies of the spatial extent of surface urban heat island (SUHI or UHISurf) effects require precise determination of the footprint (FP) boundary. Currently available methods overestimate or underestimate the SUHI FP boundary, and can even alter its morphology, due to theoretical limitations on the ability of their algorithms to accurately determine the impacts of the shape, topography, and landscape heterogeneity of the city. The key to determining the FP boundary is identifying background temperatures in reference rural regions. Due to the instability of remote sensing data, these background temperatures should be determined automatically rather than manually, to eliminate artificial bias. To address this need, we developed an algorithm that adequately represents the decay of land surface temperature (LST) from the urban center to surrounding rural regions, and automatically calculates thresholds for reference rural LSTs in all directions based on a logistic curve. In this study, we applied this algorithm with data from the Aqua Moderate Resolution Imaging Spectroradiometer (Aqua/MODIS) 8-day level 3 (L3) LST global grid product to delineate precise SUHI FPs for the Beijing metropolitan area during the summers of 2004–2018 and determine the interannual and diurnal variations in FP boundaries and their relationship with SUHI intensity.
A Secure and Efficient Data Sharing and Searching Scheme in Wireless Sensor Networks
Authors: Zhu Binrui , Susilo Willy , Qin Jing , Guo Fuchun , Zhao Zhen , Ma Jixin
Published: June 2019

Wireless sensor networks (WSN) generally utilize cloud computing to store and process sensing data in real time, namely, cloud-assisted WSN. However, the cloud-assisted WSN faces new security challenges, particularly outsourced data confidentiality. Data Encryption is a fundamental approach but it limits target data retrieval in massive encrypted data. Public key encryption with keyword search (PEKS) enables a data receiver to retrieve encrypted data containing some specific keyword in cloud-assisted WSN. However, the traditional PEKS schemes suffer from an inherent problem, namely, the keyword guessing attack (KGA). KGA includes off-line KGA and on-line KGA. To date, the existing literature on PEKS cannot simultaneously resist both off-line KGA and on-line KGA performed by an external adversary and an internal adversary. In this work, we propose a secure and efficient data sharing and searching scheme to address the aforementioned problem such that our scheme is secure against both off-line KGA and on-line KGA performed by external and internal adversaries. We would like to stress that our scheme simultaneously achieves document encryption/decryption and keyword search functions. We also prove our scheme achieves keyword security and document security. Furthermore, our scheme is more efficient than previous schemes by eliminating the pairing computation.
The AM4I Architecture and Framework for Multimodal Interaction and Its Application to Smart Environments
Authors: Almeida Nuno , Teixeira António , Silva Samuel , Ketsmur Maksym
Published: June 2019

Technologies, such as smart sensors, actuators, and other kinds of devices, are often installed in our environments (e.g., our Homes) and available to integrate our daily lives. Despite their installation being motivated by the pursuit of automation and increased efficiency, making these environments usable, acceptable and enjoyable in a sustainable, energy efficient way is not only a matter of automation. Tackling these goals is a complex task demanding the combination of different perspectives including building and urban Architecture, Ubiquitous Computing and Human-Computer Interaction (HCI) to provide occupants with the means to shape these environments to their needs. Interaction is of paramount relevance in the creation of adequate relations of users with their environments, but it cannot be seen independently from the ubiquitous sensing and computing or the environment’s architecture. In this regard, there are several challenges to HCI, particularly in how to integrate this multidisciplinary effort. Although there are several solutions to address some of these challenges, the complexity and dynamic nature of the smart environments and the diversity of technologies involved still present many challenges, particularly for its development. In general, the development is complex, and it is hard to create a dynamic environment providing versatile and adaptive forms of interaction. To participate in the multidisciplinary effort, the development of interaction must be supported by tools capable of facilitating co-design by multidisciplinary teams. In this article, we address the development of interaction for complex smart environments and propose the AM4I architecture and framework, a novel modular approach to design and develop adaptive multiplatform multilingual multi-device multimodal interactive systems. The potential of the framework is demonstrated by proof-of-concept applications in two different smart environment contexts, non-residential buildings and smart homes.
A New Fault Diagnosis Method for a Diesel Engine Based on an Optimized Vibration Mel Frequency under Multiple Operation Conditions
Authors: Zhao Haipeng , Zhang Jinjie , Jiang Zhinong , Wei Donghai , Zhang Xudong , Mao Zhiwei
Published: June 2019

The diesel engine has been a significant component of large-scale mechanical systems for the intelligent manufacturing industry. Because of its complex structure and poor working environment, it has trouble effectively acquiring the representative fault features. Further, fault diagnosis of the diesel engine faces great challenges. This paper presents a new fault diagnosis method for the detection of diesel engine faults under multiple operation conditions instead of conventional methods confined to a single condition. First, an adaptive correlation threshold process is designed as a preprocessing unit to enhance data quality by weakening non-impact region characteristics. Next, a feature extraction method for sound signals based on the Mel frequency cepstrum (MFC) is improved and introduced into the machinery fault diagnosis. Then, the combination of the improved feature and vibrational mode decomposition (VMD) is proposed to incorporate VMD into an effective adaptive decomposition of non-stationary signals to combine it with an excellent feature representation of the vibration signal. Finally, the vector quantization algorithm is adopted to reduce the feature dimensions and generate codebook model bases, which trains the K-Nearest Neighbor classifiers. Five comparative methods were carried out, and the experimental results show that the proposed method offers a good effect of the common valve clearance fault of diesel engines under different conditions.
MicroGal Gravity Measurements with MGS-6 Micro-g LaCoste Gravimeter
Authors: Przyborski Marek , Pyrchla Jerzy , Pyrchla Krzysztof , Szulwic Jakub
Published: June 2019

The article discusses the registration of micro-gravity changes with the MGS-6 Micro-g LaCoste gravity sensor during static measurements. An experiment was carried out to determine how small changes in gravity can be registered using the MGS-6 system sensor. The tides of the Earth’s crust were chosen as the source of disturbance of the field with small amplitude and long-term changes. The tested sensor was placed in a geophysical observatory on a specially designed tripod. Simultaneously on the nearby concrete pillar, the registration of changes in gravity was carried out using the superconducting iGrav gravimeter. The high temporal stability of the superconducting gravimeters and the low noise combined with leading sensitivity of its reading allow it to be considered as a reliable reference source for MGS-6. The article discusses the impact of non-leveling changes of the MGS-6 gravimetry on the reading and determines the size of its non-linear drift. The obtained differences in indications between devices did not exceed 50 μ Gal for 68% of data. The measurements also showed excellent time stability of the MGS-6 measurement system. The data collected during the experiment allowed determining the level of accuracy that can be sought during real measurements using the MGS-6 system on research vessels. They also give an overview of the dynamics of the drift phenomenon of the analyzed research system.
An Adaptive Track Segmentation Algorithm for a Railway Intrusion Detection System
Authors: Wang Yang , Zhu Liqiang , Yu Zujun , Guo Baoqing
Published: June 2019

Video surveillance-based intrusion detection has been widely used in modern railway systems. Objects inside the alarm region, or the track area, can be detected by image processing algorithms. With the increasing number of surveillance cameras, manual labeling of alarm regions for each camera has become time-consuming and is sometimes not feasible at all, especially for pan-tilt-zoom (PTZ) cameras which may change their monitoring area at any time. To automatically label the track area for all cameras, video surveillance system requires an accurate track segmentation algorithm with small memory footprint and short inference delay. In this paper, we propose an adaptive segmentation algorithm to delineate the boundary of the track area with very light computation burden. The proposed algorithm includes three steps. Firstly, the image is segmented into fragmented regions. To reduce the redundant calculation in the evaluation of the boundary weight for generating the fragmented regions, an optimal set of Gaussian kernels with adaptive directions for each specific scene is calculated using Hough transformation. Secondly, the fragmented regions are combined into local areas by using a new clustering rule, based on the region’s boundary weight and size. Finally, a classification network is used to recognize the track area among all local areas. To achieve a fast and accurate classification, a simplified CNN network is designed by using pre-trained convolution kernels and a loss function that can enhance the diversity of the feature maps. Experimental results show that the proposed method finds an effective balance between the segmentation precision, calculation time, and hardware cost of the system.
Keep Your Head Up—Correlation between Visual Exploration Frequency, Passing Percentage and Turnover Rate in Elite Football Midfielders
Authors: Phatak Ashwin , Gruber Markus
Published: June 2019

Statistical analysis of real in-game situations plays an increasing role in talent identification and player recruitment across team sports. Recently, visual exploration frequency (VEF) in football has been discussed as being one of the important performance-determining parameters. However, until now, VEF has been studied almost exclusively in laboratory settings. Moreover, the VEF of individuals has not been correlated with performance parameters in a statistically significant number of top-level players. Thus, the objective of the present study was to examine the relationship between VEF and individual performance parameters in elite football midfielders. Thirty-five midfielders participating in the Euro 2016 championship were analyzed using game video. Their VEF was categorized into scans, transition scans, and total scans. Linear regression analysis was used to correlate the three different VEF parameters with the passing percentage and the turnover rate for individual players. The linear regression showed significant positive correlations between scan rate (p = 0.033, R 2 = 3.0%) and total scan rate (p = 0.015, R 2 = 4.0%) and passing percentage but not between transition scan rate and passing percentage (p = 0.074). There was a significant negative correlation between transition scan rate and turnover rate (p = 0.023, R 2 = 3.5%) but not between total scan rate (p = 0.857) or scan rate (p = 0.817) and turnover rate. In conclusion, the present study shows that players with a higher VEF may complete more passes and cause fewer turnovers. VEF explains up to 4% of variance in pass completion and turnover rate and thus should be considered as one of the factors that can help to evaluate players and identify talents as well as to tailor training interventions to the needs of midfielders up to the highest level of professional football.
Gastrointestinal Complaints and Correlations with Self-Reported Macronutrient Intake in Independent Groups of (Ultra)Marathon Runners Competing at Different Distances
Authors: Hoogervorst Daan , van der Burg Nancy , Versteegen Joline J. , Lambrechtse Karin J. , Redegeld Martijn I. , Cornelissen Larissa A. J. , Wardenaar Floris C.
Published: June 2019

This study investigated the differences in gastrointestinal (GI) and exercise related complaints between groups of runners competing at different distances using web-based questionnaires. Total (severe) complaints were reported by 89.3% (49.7%) of the runners during the race vs. 70.6% (29.4%) after the race. Significant differences between groups were described for marathon (n = 98) and 60 km (n = 43) runners. During competition, runners reported the urge to urinate (47.7%), muscle cramps (43.6%) and belching (43.6%). The prevalence of bloating, flatulence, side ache and dizziness differed between distances (p < 0.02). There were small to moderate negative correlations between food and fluid intake and GI complaints. After competition (12 h), 70.6% of participants reported complaints, with muscle cramps (47.6%), flatulence (19.0%) and bloating (12.7%) being the most prevalent. Prevalence of belching, nausea, stomach cramps and muscle cramps differed between race distances (p < 0.04). There were small to high positive correlations between complaints during and after competition (p < 0.05). In conclusion, runners of all distances reported a high prevalence of GI and other exercise related complaints. There were some small differences in reporting type and severity of complaints between distances. Results showed small to strong correlations between complaints during and after competition and with nutrient intake, without a clear similar pattern for all distances.