bluuebunny/crossref_metadata_2025 huggingface dataset:
VAT Method for Visualization of Mass Movement Features: An Alternative to Hillshaded DEM
Authors: Verbovšek Timotej , Popit Tomislav , Kokalj Žiga
Published: December 2019

Hillshaded digital elevation models are a well-known information layer used to determine the geomorphological properties of landslides. However, their use is limited because the results are dependent on a particular sun azimuth and elevation. Approaches proposed to overcome this bias include positive openness, sky-view factor, red relief image maps, and prismatic openness. We propose an upgrade to all these methods, a method named Visualization for Archaeological Topography (VAT). The method is based on a fusion of four information layers into a single image (hillshaded terrain, slope, positive openness, and sky-view factor). VAT can be used to enhance visibility of features of varied scale, height, orientation, and form that sit on terrain ranging from extremely flat to very steep. Besides this, the merits of VAT are that the results are comparable across diverse geographical areas. We have successfully tested the method for landslide recognition and analysis in five different areas in the Vipava Valley (SW Slovenia). Geomorphology of the area is very diverse and holds various types of mass movements. In contrast to classical hillshaded digital elevation models (DEMs), the geomorphological features of landslides obtained by the VAT method are very clearly seen in all studied mass movements.
A Review of Earth Observation-Based Analyses for Major River Basins
Authors: Uereyen Soner , Kuenzer Claudia
Published: December 2019

Regardless of political boundaries, river basins are a functional unit of the Earth’s land surface and provide an abundance of resources for the environment and humans. They supply livelihoods supported by the typical characteristics of large river basins, such as the provision of freshwater, irrigation water, and transport opportunities. At the same time, they are impacted i.e., by human-induced environmental changes, boundary conflicts, and upstream–downstream inequalities. In the framework of water resource management, monitoring of river basins is therefore of high importance, in particular for researchers, stake-holders and decision-makers. However, land surface and surface water properties of many major river basins remain largely unmonitored at basin scale. Several inventories exist, yet consistent spatial databases describing the status of major river basins at global scale are lacking. Here, Earth observation (EO) is a potential source of spatial information providing large-scale data on the status of land surface properties. This review provides a comprehensive overview of existing research articles analyzing major river basins primarily using EO. Furthermore, this review proposes to exploit EO data together with relevant open global-scale geodata to establish a database and to enable consistent spatial analyses and evaluate past and current states of major river basins.
Robust Statistics for GNSS Positioning under Harsh Conditions: A Useful Tool?
Authors: Medina Daniel , Li Haoqing , Vilà-Valls Jordi , Closas Pau
Published: December 2019

Navigation problems are generally solved applying least-squares (LS) adjustments. Techniques based on LS can be shown to perform optimally when the system noise is Gaussian distributed and the parametric model is accurately known. Unfortunately, real world problems usually contain unexpectedly large errors, so-called outliers, that violate the noise model assumption, leading to a spoiled solution estimation. In this work, the framework of robust statistics is explored to provide robust solutions to the global navigation satellite systems (GNSS) single point positioning (SPP) problem. Considering that GNSS observables may be contaminated by erroneous measurements, we survey the most popular approaches for robust regression (M-, S-, and MM-estimators) and how they can be adapted into a general methodology for robust GNSS positioning. We provide both theoretical insights and validation over experimental datasets, which serves in discussing the robust methods in detail.
Evaluation of Pattern Recognition Methods for Head Gesture-Based Interface of a Virtual Reality Helmet Equipped with a Single IMU Sensor
Authors: Hachaj Tomasz , Piekarczyk Marcin
Published: December 2019

The motivation of this paper is to examine the effectiveness of state-of-the-art and newly proposed motion capture pattern recognition methods in the task of head gesture classifications. The head gestures are designed for a user interface that utilizes a virtual reality helmet equipped with an internal measurement unit (IMU) sensor that has 6-axis accelerometer and gyroscope. We will validate a classifier that uses Principal Components Analysis (PCA)-based features with various numbers of dimensions, a two-stage PCA-based method, a feedforward artificial neural network, and random forest. Moreover, we will also propose a Dynamic Time Warping (DTW) classifier trained with extension of DTW Barycenter Averaging (DBA) algorithm that utilizes quaternion averaging and a bagged variation of previous method (DTWb) that utilizes many DTW classifiers that perform voting. The evaluation has been performed on 975 head gesture recordings in seven classes acquired from 12 persons. The highest value of recognition rate in a leave-one-out test has been obtained for DTWb and it equals 0.975 (0.026 better than the best of state-of-the-art methods to which we have compared our approach). Among the most important applications of the proposed method is improving life quality for people who are disabled below the neck by supporting, for example, an assistive autonomous power chair with a head gesture interface or remote controlled interfaces in robotics.
Efficient CORDIC Iteration Design of LiDAR Sensors’ Point-Cloud Map Reconstruction Technology
Authors: Fan Yu-Cheng , Liu Yi-Cheng , Chu Chiao-An
Published: December 2019

In this paper, we propose an efficient COordinate Rotation DIgital Computer (CORDIC) iteration circuit design for Light Detection and Ranging (LiDAR) sensors. A novel CORDIC architecture that achieves the goal of pre-selecting angles and reduces the number of iterations is presented for LiDAR sensors. The value of the trigonometric functions can be found in seven rotations regardless of the number of input N digits. The number of iterations are reduced by more than half. The experimental results show the similarity value to be all 1 and prove that the LiDAR decoded packet results are exactly the same as the ground truth. The total chip area is 1.93 mm × 1.93 mm and the core area is 1.32 mm × 1.32 mm, separately. The number of logic gates is 129,688. The designed chip only takes 0.012 ms and 0.912 ms to decode a packet and a 3D frame of LiDAR sensors, respectively. The throughput of the chip is 8.2105   ×   10 8 bits/sec. The average power consumption is 237.34 mW at a maximum operating frequency of 100 MHz. This design can not only reduce the number of iterations and the computing time but also reduce the chip area. This paper provides an efficient CORDIC iteration design and solution for LiDAR sensors to reconstruct the point-cloud map for autonomous vehicles.
Optimized LOAM Using Ground Plane Constraints and SegMatch-Based Loop Detection
Authors: Liu Xiao , Zhang Lei , Qin Shengran , Tian Daji , Ouyang Shihan , Chen Chu
Published: December 2019

Reducing the cumulative error in the process of simultaneous localization and mapping (SLAM) has always been a hot issue. In this paper, in order to improve the localization and mapping accuracy of ground vehicles, we proposed a novel optimized lidar odometry and mapping method using ground plane constraints and SegMatch-based loop detection. We only used the lidar point cloud to estimate the pose between consecutive frames, without any other sensors, such as Global Positioning System (GPS) and Inertial Measurement Unit (IMU). Firstly, the ground plane constraints were used to reduce matching errors. Then, based on more accurate lidar odometry obtained from lidar odometry and mapping (LOAM), SegMatch completed segmentation matching and loop detection to optimize the global pose. The neighborhood search was also used to accomplish the loop detection task in case of failure. Finally, the proposed method was evaluated and compared with the existing 3D lidar SLAM methods. Experiment results showed that the proposed method could realize low drift localization and dense 3D point cloud map construction.
Mapping and Tracking Forest Burnt Areas in the Indio Maiz Biological Reserve Using Sentinel-3 SLSTR and VIIRS-DNB Imagery
Authors: Chiang Shou-Hao , Ulloa Noel Ivan
Published: December 2019

Wildfires are considered one of the most major hazards and environmental issues worldwide. Recently, Earth observation satellite (EOS) sensors have proven to be effective for wildfire detection, although the quality and usefulness of the data are often hindered by cloud presence. One practical workaround is to combine datasets from multiple sensors. This research presents a methodology that utilizes data of the recently-launched Sentinel-3 sea and land surface temperature radiometer (S3-SLSTR) to reflect its applicability for detecting wildfires. In addition, visible infrared imaging radiometer suite day night band (VIIRS-DNB) imagery was introduced to assure day-night tracking capabilities. The wildfire event in the Indio Maiz Biological Reserve, Nicaragua, during 3–13 April 2018, was the study case. Six S3-SLSTR images were processed to compute spectral indices, such as the normalized difference vegetation index (NDVI), the normalized difference water index (NDWI), and the normalized burn ratio (NBR), to perform image segmentation for estimating the burnt area. The results indicate that 5870.7 ha of forest was affected during the wildfire, close to the 5945 ha reported by local authorities. In this study, the fire expansion was delineated and tracked in the Indio Maiz Biological Reserve using a modified fast marching method on nighttime-sensed temporal VIIRS-DNB. This study shows the importance of S3-SLSRT for wildfire monitoring and how it can be complemented with VIIRS-DNB to track burning biomass at daytime and nighttime.
Research of a Radar Imaging Algorithm Based on High Pulse Repetition Random Frequency Hopping Synthetic Wideband Waveform
Authors: He Songhua , Wu Xiaotian
Published: December 2019

Aiming at the imaging algorithm of high-pulse-repetition random-frequency-hopping synthetic wideband radar on a supersonic/hypersonic aircraft platform, this study established an echo simulation model of target and clutter, analyzed the special range-Doppler coupling effect and its influence on imaging, and proposes a method of imaging with pipeline-parallel processing based on generalized 2D matched-filtering and Doppler pre-processing. In the method, Doppler-beam-sharpening was advanced to be performed with the pulse compression process in each frame, and the special range-Doppler coupling effect caused by high dynamic motion of platform and random frequency hopping in bandwidth synthesis was well suppressed; several modes of random frequency hopping were designed and the pipeline-parallel image processing algorithm was optimized for each mode. Theoretical analysis and simulation results show that the proposed imaging method can effectively avoid the divergence of 2D range-Doppler images in the range direction, and can meet the requirements of real-time imaging.
Proposal to Reuse Rubber Waste from End-Of-Life Tires Using Thermosetting Resin
Authors: Buss Andre Hekermann , Kovaleski João Luiz , Pagani Regina Negri , da Silva Vander Luiz , Silva Jaqueline de Matos
Published: December 2019

Due to the increasing production of motor vehicles, a large amount of waste with different characteristics and compositions is generated, notably end-of-life tires, which are harmful to the environment when not properly disposed. Their composition contains contaminating chemical elements, resulting in negative impacts on the environment. This research aims to present a process that favors the recycling of rubber waste from end-of-life tires. For the construction of the state of the art and state of the technique, a review of the literature on end-of-life tire rubber, and a search on Google Patents and Espacenet was done using Methodi Ordinatio. For the experimental work, samples were made using concentrations of 20%, 40%, and 60% of end-of-life tire rubber particles, with the addition of thermoset polymeric matrix of isophthalic polyester resin, catalyst, and dyes. In order to evaluate the quality of the mixture, some tests with the material resulting from the mixture were performed: Izod impact strength, Shore D hardness, immersion density determination, flexural strength, and scanning electron microscopy analysis. The results from the tests indicate that the composition with 60% of rubber particles had better mechanical results than samples containing 20% and 40%. The tests also show that end-of-life tire particles promote chemical adsorption (interaction) with the thermoset polymer matrix, favoring the mechanical properties. The final results of this research are: the literature review and the search on granted patents showed that this study is original; the experimental work suggests that practical applications are possible, generating a new product, harder with a proportion of 60% of rubber particles, as indicated by the tests, with a smooth surface that does not require polishing. Thus, this research is characterized as innovative as well as having sustainable characteristics.
Understanding Tourists’ Willingness-to-Pay for Rural Landscape Improvement and Preference Heterogeneity
Authors: Cong Li , Zhang Yujun , Su Ching-Hui (Joan) , Chen Ming-Hsiang , Wang Jinnan
Published: December 2019

With the vigorous development of urbanization and rural tourism, the landscape of villages and towns has undergone tremendous changes under the influence of policies and industries. In order to avoid irreversible changes in the local heritage landscape and promote local sustainable development, it is necessary to strengthen the attention and research on the rural recreation landscape. This research examines the value of rural landscape recreation by applying the choice experiment method (CEM) to a suburban area in Sichuan, China. Mixed logit models were adopted in examining tourists’ willingness-to-pay (WTP) for rural landscape improvement and preference heterogeneity. An assessment of the rural landscape’s recreational value was made using the compensating surplus calculation method. Results reported are of four important landscape elements: ecological environment, rural life and associated productive landscape, rural housing, and service landscape, ranked by tourists from high-to-low. A major finding of the research is that an increase in rural tourism is dependent upon improvements to landscape elements. The results of this research can provide policymakers with valuable information necessary to develop a successful plan to attract and increase tourism in rural areas of China.
Mass Appraisal Models of Real Estate in the 21st Century: A Systematic Literature Review
Authors: Wang Daikun , Li Victor Jing
Published: December 2019

With the increasing volume and active transaction of real estate properties, mass appraisal has been widely adopted in many countries for different purposes, including assessment of property tax. In this paper, 104 papers are selected for the systematic literature review of mass appraisal models and methods from 2000 to 2018. The review focuses on the application trend and classification of mass appraisal and highlights a 3I-trend, namely AI-Based model, GIS-Based model and MIX-Based model. The characteristics of different mass appraisal models are analyzed and compared. Finally, the future trend of mass appraisal based on model perspective is defined as “mass appraisal 2.0”: mass appraisal is the appraisal procedure of model establishment, analysis and test of group of properties as of a given date, combined with artificial intelligence, geo-information systems, and mixed methods, to better model the real estate value of non-spatial and spatial data.
Analysis of Energy-Related Carbon Emissions in Inner Mongolia, China
Authors: Tseng Sheng-Wen
Published: December 2019

Inner Mongolia has shown both rapid economic growth and a large renewable energy base, this has come about by the introduction of the “Western Development” strategy and renewable energy policy of the Chinese Government. However, this has led to a contradictory situation where both high carbon emission and reduction exist together. The average economic growth of Inner Mongolia reached 15.76% between 2006 and 2016, which caused huge CO2 emissions. However, promotion of the renewable energy policy (since 2005) resulted in an energy self-sufficiency rate that reached 270.80% by 2016. In this study of the Inner Mongolia carbon emission situation, the logarithmic mean divisia index (LMDI) model was used to analyze the factors affecting carbon emission fluctuations from 2005 to 2016. The decoupling elasticity index was then used to measure the decoupling effect of the economic growth and carbon emissions. The results of this research show that: firstly, CO2 emissions increased rapidly from 651.03 million tons in 2006 to 1723.24 million tons in 2013. Despite a slight decline in CO2 emissions, a level above 1600 million tons was maintained between 2014 and 2016. Secondly, the industry sector was the main source of CO2 emissions in Inner Mongolia, and coal-based fuel played a determining role. Thirdly, in this study, two important contributions were made, including the discovery of two new drivers: labor and emission intensity factors. Further, findings about the effect of the six industrial sectors, economic structure, energy density, and emission intensity factors were also decomposed. It was found that during research period, the population factor, labor factor, and labor productivity factor all had a positive influence on CO2 emissions, whereas the economic structure factor and emission intensity factor had different impacts on the CO2 emissions depending on the particular industrial sector. Furthermore, the energy intensity of six industrial sectors contributed to the decrease in aggregate CO2 emissions. Finally, in this study, it was also found that economic growth and CO2 growth in Inner Mongolia presented a weak decoupling state. Policy recommendations based on these results have been presented.
Agricultural Transformations in the Southern Cone of Latin America: Agricultural Intensification and Decrease of the Aboveground Net Primary Production, Uruguay’s Case
Authors: Gazzano Inés , Achkar Marcel , Díaz Ismael
Published: December 2019

The agri-exporting enclaves of the current corporate food regime intensively exploit natural assets in global strategies that govern the local processes. Their multidimensional impacts contribute to the environmental and civilizational crisis. Linked to the agrarian metabolism in its appropriation phase, land use has impacts on local systems. To understand this process, it is necessary to identify the systemic and spatial expression of environmental transformation. The objective of this work was to analyze the dynamic adjustment of aboveground net primary production (ANPP) to agricultural intensification between the years 2000 and 2017, using a land use intensity index and the soils’ productive potential. Agricultural expansion and consolidation are observed, as well as the significant intensification throughout the period in 65% of the country’s area—with differences between regions—associated with soil types. ANPP is higher in areas of low land use intensity and lower in high intensity areas, varying from high to low in soils with low to high productive potential, respectively, and growing throughout the period—depending on the area, with less growth in areas of greater intensity. The appropriation of edaphic wealth puts the systemic functionality at risk and challenges these transforming dynamics, with a strong impact on southern systems.
Vertical Characteristics of Winter Ozone Distribution within the Boundary Layer in Shanghai Based on Hexacopter Unmanned Aerial Vehicle Platform
Authors: Chen Qian , Wang Dongsheng , Li Xiaobing , Li Bai , Song Ruifeng , He Hongdi , Peng Zhongren
Published: December 2019

Ozone is an important secondary air pollutant and plays different significant roles in regulating the formation of secondary organic aerosols. However, the characteristics of winter vertical ozone distributions have rarely been studied. In the winter of 2017, field experiments were performed in Shanghai, China using hexacopter unmanned aerial vehicle (UAV) platforms. The vertical profiles of ozone were obtained from 0–1200 m above the ground level. Results show that the UAV observations were reliable to capture the vertical variations of ozone. Vertical ozone profiles in the winter are classified into four categories: (1) well-mixed profile, (2) altitudinal increasing profile, (3) stratification profile, and (4) spike profile. Results show that although the average surface ozone level was relatively low, strong ozone variability and high ozone concentrations occurred at the upper air. The maximum observed ozone concentration was 220 ppb. In addition, using meteorological profiles and backward trajectories, we found that the ozone elevation aloft can be attributed to the downward transport of air flow from higher altitudes. Furthermore, ozone accumulation in the winter could be influenced by the horizontal transport of air masses for the northern part of China. This study successfully used hexacopter UAV platforms to perform vertical observations within the boundary layer. This provides systematic classification of winter ozone distribution within the boundary layer.
The Effects of Biodegradable Mulch Film on the Growth, Yield, and Water Use Efficiency of Cotton and Maize in an Arid Region
Authors: Deng Lu , Yu Yang , Zhang Haiyan , Wang Qian , Yu Ruide
Published: December 2019

Plastic residual film pollution in China is severe, and the use of degradable mulch film instead of plastic mulch can effectively alleviate this situation. The substitution of common polyethylene plastic mulch film with biodegradable mulch film in the agricultural production of cotton and maize in an arid region was investigated in the present study. Using bare soil as the control, we compared the effects of common polyethylene plastic film and biodegradable mulch film on crop growth, yield, and water use efficiency (WUE) in maize and cotton. The results indicated that: (1) the biodegradable mulch film in this region remained intact for 60 days after being laid down, significantly degrading after 120 days, and was associated with increased soil temperature, moisture conservation, and degradability in comparison to a bare soil control; (2) Both the biodegradable mulch film and the polyethylene plastic film significantly increased various physiological parameters, such as crop height, stalk diameter, and leaf area; (3) The biodegradable mulch film had a significant effect on crop yield by 69.4–76.2% and 65.2–71.9%, respectively, compared to the bare soil control. (4) Compared to the bare soil control, the biodegradable mulch film effectively increased WUE in the crops by 64.5–73.1%. In summary, biodegradable mulch film had comparable results to the common polyethylene plastic film in increasing crop growth, yield, and WUE. As the biodegradable mulch film causes no residual pollution, it is thus preferable to common plastic mulch film for agricultural applications in arid regions and supports the sustainable development of agroecosystems. Therefore, the use of degradable mulch films in agricultural production is more environmentally friendly and more conducive to the sustainable development of agricultural systems.
Innovation System Assessment Model for Sustainability Planning in Taiwan
Authors: Hung Shiu-Wan , Chang Chao-Liang , Liu Shu Ming
Published: December 2019

Research evidence has shown that innovation systems play crucial roles in the sustainability of a country. Taiwan as a natural resource-restricted society with a unique situation should pay great attention to related topics. Regarding this, scientific and strategic foresight planning is engaged in order to be competitive and sustainable. An advanced plan with evaluation and police research was revealed in this study, which utilized DEA (data envelope analysis) to reform qualitative principles and quantitively evaluate 22 counties of Taiwan, exploring potential opportunities among the counties. Moreover, based on the findings, a rational suggestion of smart healthcare development was investigated to help in decision making. In comparing the practical evidence with results, we conclude following viewpoints: First, sometimes policies have to be made with limited data and time because of the rapidly changing environment, though an effective solution to consistently bridge the conceptual principles with quantitative results is feasible. Second, we show quantitative results derived from qualitative principles that uncover missing phenomena from intuitive discussions. Third, by adapting the observation boundaries with variables, a new scenario can be exposed to meaningfully support decisions in new territories, including sustainability. Compared to intuitive decisions, scientific planning is fruitful according to social consensus in order to lay the foundation for sustainability.
The Sustainable Development of the China Pakistan Economic Corridor: Synergy among Economic, Social, and Environmental Sustainability
Authors: Awais Muhammad , Samin Tanzila , Gulzar Muhammad Awais , Hwang Jinsoo
Published: December 2019

This case study focuses on how economic, social and environmental factors synergize for sustainable development, and relates to fundamental speculations, looking to unclutter a query-encompassing view of the China Pakistan Economic Corridor (CPEC). This study is explanatory in nature, and identifies, recognizes, and discusses the social dispositions and fundamental sustainability dimensions related to sustainable development. Three fundamental sustainability dimensions—economic, social and environmental—are incorporated in connection with the CPEC to explore sustainable development. We submit an inclusive viewpoint of the CPEC, towards the sustainable development of economies, from neighborhoods to nations. This explanatory case reveals a momentous sprouting tie between China and Pakistan. For sustainable development in the global context, more meaningful paradigms are needed to be developed. Socio-economic diversity and strategic importance have highlighted a joint perspective and are emerging as novel ways of directing business enterprises to enter the Asian markets, thus contributing to the development and exploitation of operational economic opportunities, leading to competition for the global business market. This study integrates sustainability in connection with the scenario of the CPEC and provides a plethora of understanding.
On the Inverse Degree Polynomial
Authors: Bosch Paul , Rodríguez José Manuel , Rosario Omar , Sigarreta José María
Published: December 2019

Using the symmetry property of the inverse degree index, in this paper, we obtain several mathematical relations of the inverse degree polynomial, and we show that some properties of graphs, such as the cardinality of the set of vertices and edges, or the cyclomatic number, can be deduced from their inverse degree polynomials.
Human Visual Perception-Based Multi-Exposure Fusion Image Quality Assessment
Authors: Cui Yueli , Chen Aihua , Yang Benquan , Zhang Shiqing , Wang Yang
Published: December 2019

Compared with ordinary single exposure images, multi-exposure fusion (MEF) images are prone to color imbalance, detail information loss and abnormal exposure in the process of combining multiple images with different exposure levels. In this paper, we proposed a human visual perception-based multi-exposure fusion image quality assessment method by considering the related perceptual features (i.e., color, dense scale invariant feature transform (DSIFT) and exposure) to measure the quality degradation accurately, which is closely related to the symmetry principle in human eyes. Firstly, the L1 norm of chrominance components between fused images and the designed pseudo images with the most severe color attenuation is calculated to measure the global color degradation, and the color saturation similarity is added to eliminate the influence of color over-saturation. Secondly, a set of distorted images under different exposure levels with strong edge information of fused image is constructed through the structural transfer, thus DSIFT similarity and DSIFT saturation are computed to measure the local detail loss and enhancement, respectively. Thirdly, Gauss exposure function is used to detect the over-exposure or under-exposure areas, and the above perceptual features are aggregated with random forest to predict the final quality of fused image. Experimental results on a public MEF subjective assessment database show the superiority of the proposed method with the state-of-the-art image quality assessment models.
Structural Diversity, Characterization and Toxicology of Microcystins
Authors: Bouaïcha Noureddine , Miles Christopher , Beach Daniel , Labidi Zineb , Djabri Amina , Benayache Naila , Nguyen-Quang Tri
Published: December 2019

Hepatotoxic microcystins (MCs) are the most widespread class of cyanotoxins and the one that has most often been implicated in cyanobacterial toxicosis. One of the main challenges in studying and monitoring MCs is the great structural diversity within the class. The full chemical structure of the first MC was elucidated in the early 1980s and since then, the number of reported structural analogues has grown steadily and continues to do so, thanks largely to advances in analytical methodology. The structures of some of these analogues have been definitively elucidated after chemical isolation using a combination of techniques including nuclear magnetic resonance, amino acid analysis, and tandem mass spectrometry (MS/MS). Others have only been tentatively identified using liquid chromatography-MS/MS without chemical isolation. An understanding of the structural diversity of MCs, the genetic and environmental controls for this diversity and the impact of structure on toxicity are all essential to the ongoing study of MCs across several scientific disciplines. However, because of the diversity of MCs and the range of approaches that have been taken for characterizing them, comprehensive information on the state of knowledge in each of these areas can be challenging to gather. We have conducted an in-depth review of the literature surrounding the identification and toxicity of known MCs and present here a concise review of these topics. At present, at least 279 MCs have been reported and are tabulated here. Among these, about 20% (55 of 279) appear to be the result of chemical or biochemical transformations of MCs that can occur in the environment or during sample handling and extraction of cyanobacteria, including oxidation products, methyl esters, or post-biosynthetic metabolites. The toxicity of many MCs has also been studied using a range of different approaches and a great deal of variability can be observed between reported toxicities, even for the same congener. This review will help clarify the current state of knowledge on the structural diversity of MCs as a class and the impacts of structure on toxicity, as well as to identify gaps in knowledge that should be addressed in future research.
PirABVP Toxin Binds to Epithelial Cells of the Digestive Tract and Produce Pathognomonic AHPND Lesions in Germ-Free Brine Shrimp
Authors: Kumar Vikash , Bels Lobke De , Couck Liesbeth , Baruah Kartik , Bossier Peter , Broeck Wim Van den
Published: December 2019

Acute hepatopancreatic necrosis disease (AHPND), a newly emergent farmed penaeid shrimp bacterial disease originally known as early mortality syndrome (EMS), is causing havoc in the shrimp industry. The causative agent of AHPND was found to be a specific strain of bacteria, e.g., Vibrio and Shewanella sps., that contains pVA1 plasmid (63–70 kb) encoding the binary PirAVP and PirBVP toxins. The PirABVP and toxins are the primary virulence factors of AHPND-causing bacteria that mediates AHPND and mortality in shrimp. Hence, in this study using a germ-free brine shrimp model system, we evaluated the PirABVP toxin-mediated infection process at cellular level, including toxin attachment and subsequent toxin-induced damage to the digestive tract. The results showed that, PirABVP toxin binds to epithelial cells of the digestive tract of brine shrimp larvae and produces characteristic symptoms of AHPND. In the PirABVP-challenged brine shrimp larvae, shedding or sloughing of enterocytes in the midgut and hindgut regions was regularly visualized, and the intestinal lumen was filled with moderately electron-dense cells of variable shapes and sizes. In addition, the observed cellular debris in the intestinal lumen of the digestive tract was found to be of epithelial cell origin. The detailed morphology of the digestive tract demonstrates further that the PirABVP toxin challenge produces focal to extensive necrosis and damages epithelial cells in the midgut and hindgut regions, resulting in pyknosis, cell vacuolisation, and mitochondrial and rough endoplasmic reticulum (RER) damage to different degrees. Taken together, our study provides substantial evidence that PirABVP toxins bind to the digestive tract of brine shrimp larvae and seem to be responsible for generating characteristic AHPND lesions and damaging enterocytes in the midgut and hindgut regions.
Use of Mobile Devices with Multifunctional Sound Level Measurement Applications: Some Experiences for Urban Acoustics Education in Primary and Secondary Schools
Authors: Sakagami Kimihiro , Satoh Fumiaki , Omoto Akira
Published: December 2019

Geo-referenced sound data are often used in the field of acoustics education to learn about the urban acoustic environment. Simple soundwalks and sound collections are also employed, in which acquiring additional information such as visual data, recorded sound data, and GPS location data are helpful to produce a map with sound data and sound collection and to carry out more profound discussions in educational activities. In order to enrich these acoustic educational and environmental survey activities with a simple tool, the use of multifunctional sound-pressure level (SPL) measurement applications with mobile devices are proposed. Some experiences of combined activities of the above methods using the applications and mobile devices are reported in this paper. In this study, applications for SPL measurements, which record GPS location data, sound, photo, and video during measurements, were used to produce geo-referenced sound data. First, the accuracy of the applications was checked and we found them to have reasonable accuracy when used with iOS devices; for example, the averaged error was less than 1.5 dB(A) with iPhone XS. Next, they were actually used in a simple soundwalk-like field survey and the resulting geo-referenced sound data were presented to discuss the merits and demerits of each application. Overall, the applications used in this work were found to be useful; for example, recorded sound allowed us to check the main sound source and to carry out discussions using collected sound samples later, and photos and videos allowed us to grasp the impressions and situations around the measuring points. Therefore, these multifunctional sound level meter (SLM) applications can be effectively used for various purposes, including acoustics education for learning about urban acoustic environments.
Rapid, Unbiased PRRSV Strain Detection Using MinION Direct RNA Sequencing and Bioinformatics Tools
Authors: Tan Shaoyuan , Dvorak Cheryl M.T. , Murtaugh Michael P.
Published: December 2019

Prompt detection and effective control of porcine reproductive and respiratory syndrome virus (PRRSV) during outbreaks is important given its immense adverse impact on the swine industry. However, the diagnostic process can be challenging due to the high genetic diversity and high mutation rate of PRRSV. A diagnostic method that can provide more detailed genetic information about pathogens is urgently needed. In this study, we evaluated the ability of Oxford Nanopore MinION direct RNA sequencing to generate a PRRSV whole genome sequence and detect and discriminate virus at the strain-level. A nearly full length PRRSV genome was successfully generated from raw sequence reads, achieving an accuracy of 96% after consensus genome generation. Direct RNA sequencing reliably detected the PRRSV strain present with an accuracy of 99.9% using as few as 5 raw sequencing reads and successfully differentiated multiple co-infecting strains present in a sample. In addition, PRRSV strain information was obtained from clinical samples containing 104 to 106 viral copies or more within 6 hours of sequencing. Overall, direct viral RNA sequencing followed by bioinformatic analysis proves to be a promising approach for identification of the viral strain or strains involved in clinical infections, allowing for more precise prevention and control strategies during PRRSV outbreaks.
A Brief Introduction to Nonlinear Time Series Analysis and Recurrence Plots
Authors: Goswami Bedartha
Published: December 2019

Nonlinear time series analysis gained prominence from the late 1980s on, primarily because of its ability to characterize, analyze, and predict nontrivial features in data sets that stem from a wide range of fields such as finance, music, human physiology, cognitive science, astrophysics, climate, and engineering. More recently, recurrence plots, initially proposed as a visual tool for the analysis of complex systems, have proven to be a powerful framework to quantify and reveal nontrivial dynamical features in time series data. This tutorial review provides a brief introduction to the fundamentals of nonlinear time series analysis, before discussing in greater detail a few (out of the many existing) approaches of recurrence plot-based analysis of time series. In particular, it focusses on recurrence plot-based measures which characterize dynamical features such as determinism, synchronization, and regime changes. The concept of surrogate-based hypothesis testing, which is crucial to drawing any inference from data analyses, is also discussed. Finally, the presented recurrence plot approaches are applied to two climatic indices related to the equatorial and North Pacific regions, and their dynamical behavior and their interrelations are investigated.
Seasonal Variability in the Microbial Community and Pathogens in Wastewater Final Effluents
Authors: Chen Xiang , Lang Xiu Lu , Xu Ai-Ling , Song Zhi-Wen , Yang Juan , Guo Ming-Yue
Published: December 2019

Numerous bacteria, especially pathogens, exist in wastewater final effluents, which can lead to possible human health and ecological security risks when effluents are reused or discharged. However, the diversity, composition, and spatiotemporal dynamics of bacteria in wastewater final effluents remain poorly understood. In this study, a comprehensive analysis of the microbial community and pathogens in wastewater final effluents was performed using high-throughput sequencing. The results revealed that wastewater final effluents in autumn exhibited the highest bacterial community richness and diversity, while those in winter exhibited the lowest. Bacteria in wastewater final effluents predominantly belonged to five phyla, in the order of Proteobacteria, Actinobacteria, Planctomycetes, Bacteroidetes, and Firmicutes. At the species level, there were 8~15 dominant species in the wastewater final effluent in each season, and Dokdonella immobilis, Rhizobium gallicum, Candidatus Flaviluna lacus, and Planctomyces limnophilus were the most dominant species in spring, summer, autumn, and winter, respectively. The seasonal variability in bacteria suggested that the microbial diversity and community in wastewater final effluents were mainly influenced by temperature, salinity, disinfection methods, and flocculants. Notably, pathogenic bacteria in wastewater effluents had both the highest relative abundance and species abundance in summer. Arcobacter spp., Legionella spp., and Mycobacterium spp. were the dominant pathogenic bacteria, and all pathogenic bacteria were mainly associated with dermatosis, enteropathies, septicemia, and pneumonia.
Defining Coastal Resilience
Authors: Masselink Gerd , Lazarus Eli
Published: December 2019

The concept of resilience has taken root in the discourse of environmental management, especially regarding Building with Nature strategies for embedding natural physical and ecological dynamics into engineered interventions in developed coastal zones. Resilience is seen as a desirable quality, and coastal management policy and practice are increasingly aimed at maximising it. Despite its ubiquity, resilience remains ambiguous and poorly defined in management contexts. What is coastal resilience? And what does it mean in settings where natural environmental dynamics have been supplanted by human-dominated systems? Here, we revisit the complexities of coastal resilience as a concept, a term, and a prospective goal for environmental management. We consider examples of resilience in natural and built coastal environments, and offer a revised, formal definition of coastal resilience with a holistic scope and emphasis on systemic functionality: “Coastal resilience is the capacity of the socioeconomic and natural systems in the coastal environment to cope with disturbances, induced by factors such as sea level rise, extreme events and human impacts, by adapting whilst maintaining their essential functions.” Against a backdrop of climate change impacts, achieving both socioeconomic and natural resilience in coastal environments in the long-term (>50 years) is very costly. Cost trade-offs among management aims and objectives mean that enhancement of socioeconomic resilience typically comes at the expense of natural resilience, and vice versa. We suggest that for practical purposes, optimising resilience might be a more realistic goal of coastal zone management.
Effect of increased gravity on calcitic mineralization of test of foraminifera (protozoa)
Authors: Very Jean-Michel , Le Campion Joël
Published: December 2019

Deux espèces de Foraminifères ont été décalcifiées à l'E.D.T.A. pour permettre la reminéralisation du test après remplacement du chélateur par de l'eau de mer. Cette minéralisation a lieu sous des conditions normales d'élevage pour le groupe témoin, et sous une accélération de 1,6 G pour le groupe expérimental (accélération résultante de 1,9 G). La distribution des atomes de Ca et de Mg est analysée à l'aide de la microsonde à rayons X. Les distances interréticulaires d ainsi que les largeurs des pics de diffraction sont mesurées par diffractométrie X. L'effet de l'augmentation de la gravité se traduit différemment chez les deux espèces considérées : absence de variation du rapport de concentration Mg/Ca, absence de variation des distances interréticulaires d et accroissement des valeurs des pics de diffraction chez l'une, diminution du rapport Mg/Ca, augmentation des valeurs de d et diminution des largeurs des pics chez l'autre. Une action au niveau de la membrane cellulaire est proposée.
Approche expérimentale et naturelle de la déformation des roches par dissolution˗cristallisation, avec transfert de matière
Authors: Gratier Jean-Pierre
Published: December 2019

Divers dispositifs (déformations expérimentales, analyses sur échantillons déformés naturellement) sont décrits, qui permettent de tester des modèles de déformation des roches par dissolution˗cristallisation, avec transfert, soit par diffusion dans un fluide fixe, soit par déplacement du fluide. L'observation du changement de forme d'inclusions fluides, sous pression dans des cristaux chauffés sous un microscope permet d'établir des relations entre vitesse de déformation (ε) et divers paramètres : forme des cavités et pression interne (P). La relation ε = ƒ(P)exp[n] avec des valeurs de n autour de 3-3,5 montre l'importance de la courbure d'une surface solide˗fluide dans sa « déformation » sous pression par transfert de matière.
Dissolution expérimentale d'un rhomboèdre de calcite soumis à une contrainte. Experimental deformation, dissolution of calcite
Authors: Girou André , Esclamadon Jacqueline , Humbert Louis , Jacquin Christian , Poulet Michel , Roques Henri
Published: December 2019

Le but de l'étude est de mettre en évidence expérimentalement l'influence des contraintes mécaniques sur la dissolution d'un cristal de calcite. Les conditions expérimentales sont les suivantes : les rhomboèdres de calcite sont soumis à une contrainte parallèle à l'axe A3 (0 à 2 400 bars). Le réacteur est alimenté en eau permutée. Le débit de circulation est fixé à 5 cm³/h. La température de travail est maintenue constante à 25 °C. On constate que la pression appliquée sur le cristal augmente la vitesse globale de dissolution. Les figures de dissolution sont localisées dans la zone médiane du cristal (zone de cisaillement). Les courbes de dissolution obtenues lors des essais en compression ou en décompression sont comparables. La contrainte agirait essentiellement par augmentation de la surface de contact entre calcite et solution. Son effet sur la solubilité thermodynamique serait négligeable.
Les druides de César : digression ethnographique et neutralisation historique
Authors: Pailler Jean-Marie
Published: December 2019

César ne parle des druides que dans l’excursus ethnographique sur les Gaulois, au début du livre VI. Dans ce passage, il évoque la polyvalence des druides et leur grande influence politique. Mais dans le reste de la Guerre des Gaules, César ne parle presque jamais des druides, et s’il mentionne les nombreuses démarches de son ami éduen Diviciacus, il omet de préciser que c’était un druide. Pourtant, il est possible d’attribuer aux druides un rôle déterminant dans plusieurs événements rapportés, par ex. la rédaction du recensement helvète, la présidence d’assemblées de chefs séditieux, la réception de serments solennels, l’arbitrage entre prince rivaux. De plus, l’existence d’un chef suprême élu par les druides au cours d’une assemblée montre que les druides ont probablement conçu les premiers l’idée d’une unité de la Gaule. Le proconsul minimise le rôle des druides de façon à neutraliser leur image, mais il s’est probablement inspiré du modèle druidique pour le récupérer à son profit, car plusieurs de ses démarches montrent qu’il a voulu assumer lui-même le rôle d’arbitre suprême.
Indo-Gallici Reges
Authors: Delamarre Xavier
Published: December 2019

Les correspondances de vocabulaire entre l’indo-iranien et l’italo-celtique, signalées d’abord par Vendryes, ont été augmentées à date récente, en particulier par les travaux de E. Campanile, et ceux de l’auteur. Il s’attache ici à démontrer que le gaulois connaît quelques composés en -rīx qui ont un parallèle exact en sanskrit : 1. Svarigillus, et Svarica correspondent à skr. sva-rāj-“ indépendant” ; – 2. Samorix = véd. sam-rāj-“ chef suprême” ; – 3. Anderex, en Aquitaine, = véd. adhi-rāja “ empereur” ; – 4. Magiorix = v. ind. māha-rājá-“ grand-roi” ; – 5. Rerigonion, Ptol., citadelle des Novantae, présente (après préfixe intensif ro-> re-) la même suffixation que skr. rājanya-“ royal”.