bluuebunny/crossref_metadata_2025 huggingface dataset:
The Application of Mucoadhesive Chitosan Nanoparticles in Nasal Drug Delivery
Authors: Shim Soojin , Yoo Han Sang
Published: November 2020

Mucosal delivery of antigens can induce both humoral and cellular immune responses. Particularly, the nasal cavity is a strongly inductive site for mucosal immunity among several administration routes, as it is generally the first point of contact for inhaled antigens. However, the delivery of antigens to the nasal cavity has some disadvantages such as rapid clearance and disposition of inhaled materials. For these reasons, remarkable efforts have been made to develop antigen delivery systems which suit the nasal route. The use of nanoparticles as delivery vehicles enables protection of the antigen from degradation and sustains the release of the loaded antigen, eventually resulting in improved vaccine and/or drug efficacy. Chitosan, which exhibits low toxicity, biodegradability, good cost performance, and strong mucoadhesive properties, is a useful material for nanoparticles. The present review provides an overview of the mucosal immune response induced by nanoparticles, recent advances in the use of nanoparticles, and nasal delivery systems with chitosan nanoparticles.
Temporal Change in Alert Override Rate with a Minimally Interruptive Clinical Decision Support on a Next-Generation Electronic Medical Record
Authors: Cha Won Chul , Jung Weon , Yu Jaeyong , Yoo Junsang , Choi Jinwook
Published: November 2020

Background and objectives: The aim of this study is to describe the temporal change in alert override with a minimally interruptive clinical decision support (CDS) on a Next-Generation electronic medical record (EMR) and analyze factors associated with the change. Materials and Methods: The minimally interruptive CDS used in this study was implemented in the hospital in 2016, which was a part of the new next-generation EMR, Data Analytics and Research Window for Integrated kNowledge (DARWIN), which does not generate modals, ‘pop-ups’ but show messages as in-line information. The prescription (medication order) and alerts data from July 2016 to December 2017 were extracted. Piece-wise regression analysis and linear regression analysis was performed to determine the temporal change and factors associated with it. Results: Overall, 2,706,395 alerts and 993 doctors were included in the study. Among doctors, 37.2% were faculty (professors), 17.2% were fellows, and 45.6% trainees (interns and residents). The overall override rate was 61.9%. There was a significant change in an increasing trend at month 12 (p < 0.001). We found doctors’ positions and specialties, along with the number of alerts and medication variability, were significantly associated with the change. Conclusions: In this study, we found a significant temporal change of alert override. We also found factors associated with the change, which had statistical significance.
Spontaneous Heterotopic Pregnancy with Unaffected Intrauterine Pregnancy: Systematic Review of Clinical Outcomes
Authors: Oancea Mihaela , Ciortea Razvan , Diculescu Doru , Poienar Alexandra-Andreea , Grigore Mihaela , Lupean Roxana-Adelina , Nicula Renata , Chira Diana , Strilciuc Stefan , Mihu Dan
Published: November 2020

Background and objective: Spontaneous heterotopic pregnancy (SHP) is a rare condition represented by the synchronous coexistence of an intrauterine and an ectopic pregnancy. It rarely occurs with natural conception and is usually a consequence of assisted reproductive techniques. Diagnosis of SHP can be a challenge for the clinician. The evolution of the intrauterine pregnancy is dependent on many factors, such as the location of the heterotopic pregnancy, gestational age at the time of diagnosis, the surgical procedure, the presence of other risk factors, early or delayed management. The aim of this systematic review of the literature was to extract existing evidence on spontaneous heterotopic pregnancy with otherwise unaffected intrauterine pregnancy. Materials and Methods: From a total of 1907 database entries identified in PubMed, EMBASE and Cochrane reviews, we selected 18 papers for narrative synthesis, for which we explored the diagnostic options, treatment, and outcome of these extremely rare epidemiologic occurrences. Manuscripts were assessed using the CARE guidelines for reporting case reports. Results: The main symptom was abdominal pain, and the preferred treatment approach was surgical, more precisely, using a laparoscopic approach. Most cases presented no risk factors, and the diagnosis was mostly made in the first semester. Conclusions: Normal follow-up and evolution of intrauterine pregnancy have been observed regardless of surgical approach (open or laparoscopic). Early diagnosis and treatment are advised, as they impact maternal and fetal outcomes. Evidence on this topic is scarce, predominantly comprised of case reports with variable degrees of adherence to dissemination guidelines. More studies on this topic are required to optimize care protocols for this type of pregnancy.
Impact of Intestinal Microbiota on Growth and Feed Efficiency in Pigs: A Review
Authors: Gardiner Gillian E. , Metzler-Zebeli Barbara U. , Lawlor Peadar G.
Published: November 2020

This review summarises the evidence for a link between the porcine intestinal microbiota and growth and feed efficiency (FE), and suggests microbiota-targeted strategies to improve productivity. However, there are challenges in identifying reliable microbial predictors of host phenotype; environmental factors impact the microbe–host interplay, sequential differences along the intestine result in segment-specific FE- and growth-associated taxa/functionality, and it is often difficult to distinguish cause and effect. However, bacterial taxa involved in nutrient processing and energy harvest, and those with anti-inflammatory effects, are consistently linked with improved productivity. In particular, evidence is emerging for an association of Treponema and methanogens such as Methanobrevibacter in the small and large intestines and Lactobacillus in the large intestine with a leaner phenotype and/or improved FE. Bacterial carbohydrate and/or lipid metabolism pathways are also generally enriched in the large intestine of leaner pigs and/or those with better growth/FE. Possible microbial signalling routes linked to superior growth and FE include increased intestinal propionate production and reduced inflammatory response. In summary, the bacterial taxa and/or metabolic pathways identified here could be used as biomarkers for FE/growth in pigs, the taxa exploited as probiotics or the taxa/functionality manipulated via dietary/breeding strategies in order to improve productivity in pigs.
A Multi-Omics Protocol for Swine Feces to Elucidate Longitudinal Dynamics in Microbiome Structure and Function
Authors: Gierse Laurin , Meene Alexander , Schultz Daniel , Schwaiger Theresa , Karte Claudia , Schröder Charlotte , Wang Haitao , Wünsche Christine , Methling Karen , Kreikemeyer Bernd , Fuchs Stephan , Bernhardt Jörg , Becher Dörte , Lalk Michael , KoInfekt Study Group  , Urich Tim , Riedel Katharina
Published: November 2020

Swine are regarded as promising biomedical models, but the dynamics of their gastrointestinal microbiome have been much less investigated than that of humans or mice. The aim of this study was to establish an integrated multi-omics protocol to investigate the fecal microbiome of healthy swine. To this end, a preparation and analysis protocol including integrated sample preparation for meta-omics analyses of deep-frozen feces was developed. Subsequent data integration linked microbiome composition with function, and metabolic activity with protein inventories, i.e., 16S rRNA data and expressed proteins, and identified proteins with corresponding metabolites. 16S rRNA gene amplicon and metaproteomics analyses revealed a fecal microbiome dominated by Prevotellaceae, Lactobacillaceae, Lachnospiraceae, Ruminococcaceae and Clostridiaceae. Similar microbiome compositions in feces and colon, but not ileum samples, were observed, showing that feces can serve as minimal-invasive proxy for porcine colon microbiomes. Longitudinal dynamics in composition, e.g., temporal decreased abundance of Lactobacillaceae and Streptococcaceae during the experiment, were not reflected in microbiome function. Instead, metaproteomics and metabolomics showed a rather stable functional state, as evident from short-chain fatty acids (SCFA) profiles and associated metaproteome functions, pointing towards functional redundancy among microbiome constituents. In conclusion, our pipeline generates congruent data from different omics approaches on the taxonomy and functionality of the intestinal microbiome of swine.
Development of a Multivalent Kunjin Virus Reporter Virus-Like Particle System Inducing Seroconversion for Ebola and West Nile Virus Proteins in Mice
Authors: Tran Pham-Tue-Hung , Asghar Naveed , Höglund Urban , Larsson Olivia , Haag Lars , Mirazimi Ali , Johansson Magnus , Melik Wessam
Published: November 2020

Kunjin virus (KUNV) is an attenuated strain of the severe neurotropic West Nile virus (WNV). The virus has a single-strand positive-sense RNA genome that encodes a polyprotein. Following gene expression, the polyprotein is cleaved into structural proteins for viral packaging and nonstructural proteins for viral replication and expression. Removal of the structural genes generate subgenomic replicons that maintain replication capacity. Co-expression of these replicons with the viral structural genes produces reporter virus-like particles (RVPs) which infect cells in a single round. In this study, we aimed to develop a system to generate multivalent RVPs based on KUNV to elicit an immune response against different viruses. We selected the Ebola virus (EBOV) glycoprotein (GP) and the matrix protein (VP40) genes, as candidates to be delivered by KUNV RVPs. Initially, we enhanced the production of KUNV RVPs by generating a stable cell line expressing the KUNV packaging system comprising capsid, precursor membrane, and envelope. Transfection of the DNA-based KUNV replicon into this cell line resulted in an enhanced RVP production. The replicon was expressed in the stable cell line to produce the RVPs that allowed the delivery of EBOV GP and VP40 genes into other cells. Finally, we immunized BALB/cN mice with RVPs, resulting in seroconversion for EBOV GP, EBOV VP40, WNV nonstructural protein 1, and WNV E protein. Thus, our study shows that KUNV RVPs may function as a WNV vaccine candidate and RVPs can be used as a gene delivery system in the development of future EBOV vaccines.
Evidence for the Dissemination to Humans of Methicillin-Resistant Staphylococcus aureus ST398 through the Pork Production Chain: A Study in a Portuguese Slaughterhouse
Authors: Bouchami Ons , Fraqueza Maria João , Faria Nuno Alexandre , Alves Valquíria , Lawal Opeyemi Uwangbaoje , de Lencastre Herminia , Miragaia Maria
Published: November 2020

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) ST398 was recovered from infections in humans exposed to animals, raising public health concerns. However, contact with food producing chain as a means of transmission of LA-MRSA to humans remains poorly understood. We aimed to assess if pork production chain is a source of MRSA ST398 for human colonization and infection. MRSA from live pigs, meat, the environment, and slaughterhouse workers were analyzed by Pulsed-Field Gel Electrophoresis (PFGE), spa, MLST typing, SNPs and for antibiotic resistance and virulence gene profiles. We compared core and accessory genomes of MRSA ST398 isolated from slaughterhouse and hospital. We detected MRSA ST398 (t011, t108, t1451) along the entire pork production chain (live pigs: 60%; equipment: 38%; meat: 23%) and in workers (40%). All MRSA ST398 were multidrug resistant, and the majority carried genes encoding biocide resistance and enterotoxins. We found 23 cross-transmission events between live pigs, meat, and workers (6–55 SNPs). MRSA ST398 from infection and slaughterhouse environment belonged to the same clonal type (ST398, t011, SCCmec V), but differed in 321–378 SNPs. Pork production chain can be a source of MRSA ST398 for colonization of human slaughterhouse workers, which can represent a risk of subsequent meat contamination and human infection.
Comparative Analysis of the Global Transcriptomic Response to Oxidative Stress of Bacillus anthracis htrA-Disrupted and Parental Wild Type Strains
Authors: Zaide Galia , Elia Uri , Cohen-Gihon Inbar , Israeli Ma’ayan , Rotem Shahar , Israeli Ofir , Ehrlich Sharon , Cohen Hila , Lazar Shirley , Beth-Din Adi , Shafferman Avigdor , Zvi Anat , Cohen Ofer , Chitlaru Theodor
Published: November 2020

We previously demonstrated that the HtrA (High Temperature Requirement A) protease/chaperone active in the quality control of protein synthesis, represents an important virulence determinant of Bacillus anthracis. Virulence attenuation of htrA-disrupted Bacillus anthracis strains was attributed to susceptibility of ΔhtrA strains to stress insults, as evidenced by affected growth under various stress conditions. Here, we report a comparative RNA-seq transcriptomic study generating a database of differentially expressed genes in the B. anthracis htrA-disrupted and wild type parental strains under oxidative stress. The study demonstrates that, apart from protease and chaperone activities, HtrA exerts a regulatory role influencing expression of more than 1000 genes under stress. Functional analysis of groups or individual genes exhibiting strain-specific modulation, evidenced (i) massive downregulation in the ΔhtrA and upregulation in the WT strains of various transcriptional regulators, (ii) downregulation of translation processes in the WT strain, and (iii) downregulation of metal ion binding functions and upregulation of sporulation-associated functions in the ΔhtrA strain. These modulated functions are extensively discussed. Fifteen genes uniquely upregulated in the wild type strain were further interrogated for their modulation in response to other stress regimens. Overexpression of one of these genes, encoding for MazG (a nucleoside triphosphate pyrophosphohydrolase involved in various stress responses in other bacteria), in the ΔhtrA strain resulted in partial alleviation of the H2O2-sensitive phenotype.
Shared Extended-Spectrum β-Lactamase-Producing Salmonella Serovars between Agricultural and Aquatic Environments Revealed through invA Amplicon Sequencing
Authors: Raseala Cecilia Mahlatse , Ekwanzala Mutshiene Deogratias , Momba Maggy Ndombo Benteke
Published: November 2020

The presence of antibiotic-resistant Salmonella spp. in the environment is of great public health interest, worldwide. Furthermore, its extended-spectrum β-lactamase (ESBL)-producing strains constitute an emerging global health concern due to their limited treatment options in hospital. Therefore, this study aimed at characterising and tracking nonresistant and ESBL–producing Salmonella spp. from agricultural settings to nearby water sources highlighting their antibiotic resistance genes (ARG) and virulence factor (VF) distribution using a combination of both culture-dependent and independent methods. Furthermore, this study investigated the diversity and shared serovars among sampled matrices using amplicon sequencing of the invasion gene A (invA) of Salmonella spp. The results showed that soil had the highest prevalence of Salmonella spp. (62.5%, 65/104) and ESBL-producing Salmonella (34.6%, 36/104). For typed ARG, the most commonly detected gene was blaOXA with 75% (30/40), followed by blaCTX-M 67.5% (27/40),blaTEM 40% (16/40) and sul1 30% (12/40) gene; blaSHV gene was not detected in isolated ESBL-producing Salmonella spp. For VF, the most detected gene was invA (96.9%, 38/40), followed by spaM (17.5%, 7/40), spiC (40%, 16/40), orfL (32.5%, 13/40), misL 32.5% (13/40) and pipD 32.5 (13/40). For diversity analysis, soil, manure, irrigation water and nearby freshwater revealed 81, 68, 12 and 9 serovars, respectively. Soil, manure, irrigation water and freshwater stream samples shared five serovars, which indicated circulation of ESBL-producing Salmonella spp. within the agricultural environment and nearby water sources. Soil is therefore identified as one of the major reservoirs of ESBL-producing Salmonella spp. It is concluded that agricultural environment contamination may have a direct relationship with the presence of antibiotic-producing Salmonella in freshwater streams.
The Exploration of Novel Regulatory Relationships Drives Haloarchaeal Operon-Like Structural Dynamics over Short Evolutionary Distances
Authors: Seitzer Phillip , Yao Andrew I. , Cisneros Ariana , Facciotti Marc T.
Published: November 2020

Operons are a dominant feature of bacterial and archaeal genome organization. Numerous investigations have related aspects of operon structure to operon function, making operons exemplars for studies aimed at deciphering Nature’s design principles for genomic organization at a local scale. We consider this understanding to be both fundamentally important and ultimately useful in the de novo design of increasingly complex synthetic circuits. Here we analyze the evolution of the genomic context of operon-like structures in a set of 76 sequenced and annotated species of halophilic archaea. The phylogenetic depth and breadth of this dataset allows insight into changes in operon-like structures over shorter evolutionary time scales than have been studied in previous cross-species analysis of operon evolution. Our analysis, implemented in the updated software package JContextExplorer finds that operon-like context as measured by changes in structure frequently differs from a sequence divergence model of whole-species phylogeny and that changes seem to be dominated by the exploration of novel regulatory relationships.
Effect of Chloride Ions on the Electrochemical Oxidation of Chalcopyrite at 340 °C and 21 MPa
Authors: Wang Luying , Li Heping , Liu Qingyou , Xu Liping , Zha Lei , Lin Sen
Published: November 2020

Understanding the oxidative mechanisms of chalcopyrite in various hydrothermal fluids is of great significance to improve copper extraction and to model the geochemical cycling of copper, iron, and sulfur. This paper investigated the effect of NaCl on the electrochemical oxidation of chalcopyrite at 340 °C and 21 MPa using polarization curves, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and Raman spectroscopy. The experimental results showed that NaCl can promote chalcopyrite leaching. As NaCl concentration increases, the protective property of the oxidation layer degraded. In the absence of NaCl, the oxidation layer that consisted of CuSn, (n ≥ 1), probably with some Fe2O3 and Fe(OH)3 and also in the presence of NaCl, Fe2O3, is the principal oxidation product. More rapid ionic diffusion and further chemical reaction contributed to the improvement of chalcopyrite dissolution with increasing NaCl concentration. A dissolution mechanism is proposed in this paper to explain the chalcopyrite leaching processes which is dependent on NaCl concentration.
A Review of Silent Substitution Devices for Melanopsin Stimulation in Humans
Authors: Conus Vincent , Geiser Martial
Published: November 2020

One way to study the specific response of the non-visual melanopsin photoreceptors of the human eye is to silence the response of cones and rods. Melanopsin photoreceptors (ipRGC), highlighted in the early 2000s, are intimately linked to the circadian rhythm and therefore to our sleep and wakefulness. Rest and sleep regulation, health and cognitive functions are all linked to ipRGC and play an important role in work and human relationships. Thus, we believe that the study of ipRGC responses is important.We searched and reviewed scientific articles describing instrumentation dedicated to these studies. PubMed lists more than 90,000 articles created since the year 2000 that contain the word circadian but only 252 with silent substitution. In relation to melanopsin, we found 39 relevant articles from which only 11 give a device description for humans, which is incomplete in most cases. We did not find any consensus for light intensity description, melanopsin contrast, sequences of melanopsin light stimulation and optical setup to expose the retina to the light.
Quality of Watermelon Juice Concentrated by Forward Osmosis and Conventional Processes
Authors: Milczarek Rebecca R. , Olsen Carl W. , Sedej Ivana
Published: November 2020

Watermelon (Citrullus lanatus) juice is known for its refreshing flavor, but its high perishability limits its availability throughout the year. Watermelon juice concentrate has extended shelf-life and lower transportation and storage costs, but the conventional thermal evaporation process for concentrating juice degrades the nutritional components and sensory quality of the product. Thus, in this work, a large-scale, non-thermal forward osmosis (FO) process was used to concentrate fresh watermelon juice up to 65°Brix. The FO concentrate was compared to thermal concentrate and fresh juices, and to commercially available refrigerated watermelon juices, in terms of lycopene and citrulline content, total soluble phenolics, antioxidant activity, and sensory properties. The FO concentrate had statistically similar (p < 0.05) levels of all the nutrients of interest except antioxidant activity, when compared to the thermal concentrate. The reconstituted FO concentrate maintained the same antioxidant activity as the raw source juice, which was 45% higher than that of the reconstituted thermal concentrate. Sensory results showed that reconstituted FO concentrate resulted in highly liked juice, and it outperformed the reconstituted thermal concentrate in the sensory hedonic rating. This work demonstrates the possibility to produce a high-quality watermelon juice concentrate by forward osmosis.
Design of a Separation Process for Natural 2-Phenylethanol with Economic and Safety Considerations
Authors: Puga-Córdova Luis E. , Pérez-Sánchez Zahira A. , López-Molina Antíoco , Conde-Báez Laura , Jiménez-Gutiérrez Arturo , Conde-Mejía Carolina
Published: November 2020

The present work aimed to design a separation process for 2-phenylethanol (2-PEA) produced by whey fermentation and to evaluate its economic potential. The separation sequence consisted of a liquid–liquid extraction column followed by two distillation columns for 2-PEA purification and solvent recovery. In addition, the use of ethyl acetate as a solvent for the extraction process was analyzed. The results, aided by the Aspen Plus v.10 process simulator, showed that 2-PEA can be separated with a purity of 96% by weight. The operating cost of the process, estimated at USD 22.70 per kilogram, shows that the separation alternative developed in this work has a high economic potential. The use of ethyl acetate as a solvent was found to efficiently remove 2-PEA from the fermentation mixture. From a process safety analysis point of view, the use of a bioprocess safety index developed in this work identified the separation process sections that could require special attention as part of the safety engineering stage of the process implementation.
Fermentation of Organic Residues to Beneficial Chemicals: A Review of Medium-Chain Fatty Acid Production
Authors: Stamatopoulou Panagiota , Malkowski Juliet , Conrado Leandro , Brown Kennedy , Scarborough Matthew
Published: November 2020

Medium-chain fatty acids (MCFAs) have a variety of uses in the production of industrial chemicals, food, and personal care products. These compounds are often produced through palm refining, but recent work has demonstrated that MCFAs can also be produced through the fermentation of complex organic substrates, including organic waste streams. While “chain elongation” offers a renewable platform for producing MCFAs, there are several limitations that need to be addressed before full-scale implementation becomes widespread. Here, we review the history of work on MCFA production by both pure and mixed cultures of fermenting organisms, and the unique metabolic features that lead to MCFA production. We also offer approaches to address the remaining challenges and increase MCFA production from renewable feedstocks.
Gas Turbine Intercoolers: Introducing Nanofluids—A Mini-Review
Authors: Alsayegh Ali , Ali Naser
Published: November 2020

Coolant is one of the main factors affecting the overall thermal performance of the intercooler for the gas turbine intercooled cycle. The thermal conductivity of conventional coolants, such as water, is relatively low when compared to solid conducting materials, and therefore can hinder the progress towards achieving a compact and highly effective intercooler. Nanofluids are advanced types of working fluids that contain dispersed nanoparticles in conventional basefluids, and as such possess superior thermal conductivity compared to their counterparts. In this paper, a short review on the effect of different nanofluids on the thermal performance of gas turbines intercoolers is presented for the first time. Firstly, this work reviews the different designs of intercoolers used in gas turbines intercooled cycles. Then, it explains the different types of nanofluids and their fabrication processes. The effective parameters, such as physical stability, thermal conductivity, and viscosity are also highlighted and discussed. Furthermore, the level of enhancement in the performance of intercoolers utilizing nanofluids is demonstrated and evaluated. Lastly, the current challenges and future research directions in this field are provided.
Samnamul (Shoots of Aruncus dioicus) Inhibit Adipogenesis by Downregulating Adipocyte-Specific Transcription Factors in 3T3-L1 Adipocytes
Authors: Lee Ji Yeon , Park Jeong-Yong , Seo Hyun Taek , Seong Hyun-A , Ji Yun-Jeong , Lee Seung Eun , Seo Kyung Hye , Kim Hyung Don
Published: November 2020

Adipocyte-specific transcription factors and antioxidants are considered the best target of obesity. Aruncus dioicus var. kamtschaticus (A. dioicus, Samnamul) is easily available owing to edible and inexpensive. However, the anti-adipogenic effects of the underlying mechanism of A. dioicus extract (ADE) have not yet been reported. In the present study, we evaluate anti-adipogenic pathway in 3T3-L1 adipocytes, antioxidant activities and quantified phenolics using high-performance liquid chromatography of ADE. The results revealed ADE had reduced adipocyte differentiation (0.72-fold vs. MDI (media of differentiation) control), triglyceride (TG; 0.50-fold vs. MDI control, p < 0.001), and total cholesterol contents (0.77-fold vs. MDI control) by regulating adipocyte-specific transcription factors (C/EBPα, PPARγ, and SREBP1) and their downstream mRNA (AdipoQ, Ap2, SREBP1-c, and FAS) levels. Furthermore, ADE has higher total phenol and flavonoid contents and scavenging assay in the DPPH and ABTS+. In particularly, ADE contains chlorogenic acid (7.04 mg/kg), caffeic acid (20.14 mg/kg), ferulic acid (1.74 mg/kg), veratric acid (29.31 mg/kg), cinnamic acid (4.70 mg/kg), and quercetin (4.18 mg/kg). In conclusion, since these phenols, especially quercetin, in the ADE appear to reduce differentiation, TG and cholesterol content by regulating adipocyte-specific transcription factors in adipocytes, ADE has the potential to be developed into a new antioxidant and anti-obesity therapeutics.
Estimation of Surface Concentrations of Black Carbon from Long-Term Measurements at Aeronet Sites over Korea
Authors: Choi Yongjoo , Ghim Young Sung , Zhang Ying , Park Seung-Myung , Song In-ho
Published: November 2020

We estimated fine-mode black carbon (BC) concentrations at the surface using AERONET data from five AERONET sites in Korea, representing urban, rural, and background. We first obtained the columnar BC concentrations by separating the refractive index (RI) for fine-mode aerosols from AERONET data and minimizing the difference between separated RIs and calculated RIs using a mixing rule that can represent a real aerosol mixture (Maxwell Garnett for water-insoluble components and volume average for water-soluble components). Next, we acquired the surface BC concentrations by establishing a multiple linear regression (MLR) between in-situ BC concentrations from co-located or adjacent measurement sites, and columnar BC concentrations, by linearly adding meteorological parameters, month, and land-use type as the independent variables. The columnar BC concentrations estimated from AERONET data using a mixing rule well reproduced site-specific monthly variations of the in-situ measurement data, such as increases due to heating and/or biomass burning and long-range transport associated with prevailing westerlies in the spring and winter, and decreases due to wet scavenging in the summer. The MLR model exhibited a better correlation between measured and predicted BC concentrations than those based on columnar concentrations only, with a correlation coefficient of 0.64. The performance of our MLR model for BC was comparable to that reported in previous studies on the relationship between aerosol optical depth and particulate matter concentration in Korea. This study suggests that the MLR model with properly selected parameters is useful for estimating the surface BC concentration from AERONET data during the daytime, at sites where BC monitoring is not available.
Weakly Supervised Change Detection Based on Edge Mapping and SDAE Network in High-Resolution Remote Sensing Images
Authors: Lu Ning , Chen Can , Shi Wenbo , Zhang Junwei , Ma Jianfeng
Published: November 2020

Change detection for high-resolution remote sensing images is more and more widespread in the application of monitoring the Earth’s surface. However, on the one hand, the ground truth could facilitate the distinction between changed and unchanged areas, but it is hard to acquire them. On the other hand, due to the complexity of remote sensing images, it is difficult to extract features of difference, let alone the construction of the classification model that performs change detection based on the features of difference in each pixel pair. Aiming at these challenges, this paper proposes a weakly supervised change detection method based on edge mapping and Stacked Denoising Auto-Encoders (SDAE) network called EM-SDAE. We analyze the difference in edge maps of bi-temporal remote sensing images to acquire part of the ground truth at a relatively low cost. Moreover, we design a neural network based on SDAE with a deep structure, which extracts the features of difference so as to efficiently classify changed and unchanged regions after being trained with the ground truth. In our experiments, three real sets of high-resolution remote sensing images are employed to validate the high efficiency of our proposed method. The results show that accuracy can even reach up to 91.18% with our method. In particular, compared with the state-of-the-art work (e.g., IR-MAD, PCA-k-means, CaffeNet, USFA, and DSFA), it improves the Kappa coefficient by 27.19% on average.
Observing Snow Cover and Water Resource Changes in the High Mountain Asia Region in Comparison with Global Mountain Trends over 2000–2018
Authors: Notarnicola Claudia
Published: November 2020

The quantification of snow cover changes and of the related water resources in mountain areas has a key role for understanding the impact on several sectors such as ecosystem services, tourism and energy production. By using NASA-Moderate Resolution Imaging Spectroradiometer (MODIS) images from 2000 to 2018, this study analyzes changes in snow cover in the High Mountain Asia region and compares them with global mountain areas. Globally, snow cover extent and duration are declining with significant trends in around 78% of mountain areas, and the High Mountain Asia region follows similar trends in around 86% of the areas. As an example, Shaluli Shan area in China shows significant negative trends for both snow cover extent and duration, with −11.4% (confidence interval: −17.7%, −5.5%) and −47.3 days (confidence interval: −70.4 days, −24.4 days) at elevations >5500 m a.s.l. respectively. In spring, an earlier snowmelt of −13.5 days (confidence interval: −24.3 days, −2.0 days) in 4000–5500 m a.s.l. is detected. On the other side, Tien Shan area shows an earlier snow onset of −28.8 days (confidence interval: −44.3 days, −8.2 days) between 2500 and 4000 m a.s.l., governed by decreasing temperature and increasing snowfall. In the current analysis, the Tibetan Plateau shows no significant changes. Regarding water resources, by using Gravity Recovery and Climate Experiment (GRACE) data it was found that around 50% of areas in the High Mountain Asia region and 30% at global level are suffering from significant negative temporal trends of total water storage (including groundwater, soil moisture, surface water, snow, and ice) in the period 2002–2015. In the High Mountain Asia region, this negative trend involves around 54% of the areas during spring period, while at a global level this percentage lies between 25% and 30% for all seasons. Positive trends for water storage are detected in a maximum 10% of the areas in High Mountain Asia region and in around 20% of the areas at global level. Overall snow mass changes determine a significant contribution to the total water storage changes up to 30% of the areas in winter and spring time over 2002–2015.
Deep Learning-Based Masonry Wall Image Analysis
Authors: Ibrahim Yahya , Nagy Balázs , Benedek Csaba
Published: November 2020

In this paper we introduce a novel machine learning-based fully automatic approach for the semantic analysis and documentation of masonry wall images, performing in parallel automatic detection and virtual completion of occluded or damaged wall regions, and brick segmentation leading to an accurate model of the wall structure. For this purpose, we propose a four-stage algorithm which comprises three interacting deep neural networks and a watershed transform-based brick outline extraction step. At the beginning, a U-Net-based sub-network performs initial wall segmentation into brick, mortar and occluded regions, which is followed by a two-stage adversarial inpainting model. The first adversarial network predicts the schematic mortar-brick pattern of the occluded areas based on the observed wall structure, providing in itself valuable structural information for archeological and architectural applications. The second adversarial network predicts the pixels’ color values yielding a realistic visual experience for the observer. Finally, using the neural network outputs as markers in a watershed-based segmentation process, we generate the accurate contours of the individual bricks, both in the originally visible and in the artificially inpainted wall regions. Note that while the first three stages implement a sequential pipeline, they interact through dependencies of their loss functions admitting the consideration of hidden feature dependencies between the different network components. For training and testing the network a new dataset has been created, and an extensive qualitative and quantitative evaluation versus the state-of-the-art is given. The experiments confirmed that the proposed method outperforms the reference techniques both in terms of wall structure estimation and regarding the visual quality of the inpainting step, moreover it can be robustly used for various different masonry wall types.
Parametric Models to Characterize the Phenology of the Lowveld Savanna at Skukuza, South Africa
Authors: De Lemos Hugo , Verstraete Michel M. , Scholes Mary
Published: November 2020

Mathematical models, such as the logistic curve, have been extensively used to model the temporal evolution of biological processes, though other similarly shaped functions could be (and sometimes have been) used for this purpose. Most previous studies focused on agricultural regions in the Northern Hemisphere and were based on the Normalized Difference Vegetation Index (NDVI). This paper compares the capacity of four parametric double S-shaped models (Gaussian, Hyperbolic Tangent, Logistic, and Sine) to represent the seasonal phenology of an unmanaged, protected savanna biome in South Africa’s Lowveld, using the Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) generated by the Multi-angle Imaging SpectroRadiometer-High Resolution (MISR-HR) processing system on the basis of data originally collected by National Aeronautics and Space Administration (NASA)’s Multi-angle Imaging SpectroRadiometer (MISR) instrument since 24 February 2000. FAPAR time series are automatically split into successive vegetative seasons, and the models are inverted against those irregularly spaced data to provide a description of the seasonal fluctuations despite the presence of noise and missing values. The performance of these models is assessed by quantifying their ability to account for the variability of remote sensing data and to evaluate the Gross Primary Productivity (GPP) of vegetation, as well as by evaluating their numerical efficiency. Simulated results retrieved from remote sensing are compared to GPP estimates derived from field measurements acquired at Skukuza’s flux tower in the Kruger National Park, which has also been operational since 2000. Preliminary results indicate that (1) all four models considered can be adjusted to fit an FAPAR time series when the temporal distribution of the data is sufficiently dense in both the growing and the senescence phases of the vegetative season, (2) the Gaussian and especially the Sine models are more sensitive than the Hyperbolic Tangent and Logistic to the temporal distribution of FAPAR values during the vegetative season, and, in particular, to the presence of long temporal gaps in the observational data, and (3) the performance of these models to simulate the phenology of plants is generally quite sensitive to the presence of unexpectedly low FAPAR values during the peak period of activity and to the presence of long gaps in the observational data. Consequently, efforts to screen out outliers and to minimize those gaps, especially during the rainy season (vegetation’s growth phase), would go a long way to improve the capacity of the models to adequately account for the evolution of the canopy cover and to better assess the relation between FAPAR and GPP.
Stress Estimation through Deep Rock Core Diametrical Deformation and Joint Roughness Assessment Using X-ray CT Imaging
Authors: Kim Hanna , Diaz Melvin B. , Kim Joo Yeon , Jung Yong-Bok , Kim Kwang Yeom
Published: November 2020

In-situ stress estimation plays an important role on the success of an underground project. However, no method is error-free, and therefore a combination of methods is desirable. In this study, the in-situ stresses for a geothermal project have been assessed through the analysis of a deep rock core taken at 4.2 km, using the diametrical core deformation analysis (DCDA) method that relates the diametrical core expansion after stress relief with the stresses assuming elastic deformation. The extracted granodiorite core sample of 100 mm of diameter was intersected with a closed joint at a dip angle of 80.8° with respect to the vertical coring direction. The core sample was scanned using an industrial X-ray computed tomography (CT), and the diametrical deformation measurements were computed with CT slices. Results from using the DCDA method indicated an average horizontal stress difference of 13.3 MPa, similar to that reported for a nearby exploration well. Furthermore, the stress orientations were compared with the orientation of maximum roughness values. The results indicated a correlation between the orientation of the maximum horizontal stress and the orientation of the minimum joint roughness coefficient, implying a possible tracking of stress orientation using joint roughness anisotropy.
Comparison of Signal-Analysis Techniques for Seismic Detection System for High-Speed Train Data: Effect of Bridge Structures
Authors: Yoo Mintaek , Moon Jae Sang
Published: November 2020

This study evaluated the earthquake warning system for high-speed trains using onboard accelerometers instead of expensive seismometers. Onboard accelerometers measure the train data additional to the earthquake acceleration. The measured earthquake acceleration could also be modified by railroad-supporting bridges. To develop the data analysis system, the virtual onboard data sets are synthesized using the train acceleration data and earthquake data. Not only the earthquake acceleration data but also the earthquake responses of bridges are used for the virtual onboard data synthesis. For the analysis of synthesized data, the short-time Fourier Transform (STFT), the wavelet transform (WT), and Wigner–Ville Distribution (WVD) methods have been compared. Results show that WVD provides the best detection performance while the computational costs are large.
Computation Offloading in a Cognitive Vehicular Networks with Vehicular Cloud Computing and Remote Cloud Computing
Authors: Xu Shilin , Guo Caili
Published: November 2020

To satisfy the explosive growth of computation-intensive vehicular applications, we investigated the computation offloading problem in a cognitive vehicular networks (CVN). Specifically, in our scheme, the vehicular cloud computing (VCC)- and remote cloud computing (RCC)-enabled computation offloading were jointly considered. So far, extensive research has been conducted on RCC-based computation offloading, while the studies on VCC-based computation offloading are relatively rare. In fact, due to the dynamic and uncertainty of on-board resource, the VCC-based computation offloading is more challenging then the RCC one, especially under the vehicular scenario with expensive inter-vehicle communication or poor communication environment. To solve this problem, we propose to leverage the VCC’s computation resource for computation offloading with a perception-exploitation way, which mainly comprise resource discovery and computation offloading two stages. In resource discovery stage, upon the action-observation history, a Long Short-Term Memory (LSTM) model is proposed to predict the on-board resource utilizing status at next time slot. Thereafter, based on the obtained computation resource distribution, a decentralized multi-agent Deep Reinforcement Learning (DRL) algorithm is proposed to solve the collaborative computation offloading with VCC and RCC. Last but not least, the proposed algorithms’ effectiveness is verified with a host of numerical simulation results from different perspectives.
Efficient Path Planing for Articulated Vehicles in Cluttered Environments
Authors: Samaniego Ricardo , Rodríguez Rodrigo , Vázquez Fernando , López Joaquín
Published: November 2020

Motion planning and control for articulated logistic vehicles such as tugger trains is a challenging problem in service robotics. The case of tugger trains presents particular difficulties due to the kinematic complexity of these multiarticulated vehicles. Sampling-based motion planners offer a motion planning solution that can take into account the kinematics and dynamics of the vehicle. However, their planning times scale poorly for high dimensional systems, such as these articulated vehicles moving in a big map. To improve the efficiency of the sampling-based motion planners, some approaches combine these methods with discrete search techniques. The goal is to direct the sampling phase with heuristics provided by a faster, precociously ran, discrete search planner. However, sometimes these heuristics can mislead the search towards unfeasible solutions, because the discrete search planners do not take into account the kinematic and dynamic restrictions of the vehicle. In this paper we present a solution adapted for articulated logistic vehicles that uses a kinodynamic discrete planning to bias the sampling-based algorithm. The whole system has been applied in two different towing tractors (a tricycle and a quadricycle) with two different trailers (simple trailer and synchronized shaft trailer).
Transient Analysis of Fresnel Zone Plates for Ultrasound Focusing Applications
Authors: Pérez-López Sergio , Tarrazó-Serrano Daniel , Dolmatov Dimitry O. , Rubio Constanza , Candelas Pilar
Published: November 2020

Fresnel Zone Plates are planar lenses that can be used to focus ultrasound beams. This kind of acoustic lenses can play a key role in the resolution of ultrasonic NDT systems. In this type of pulse-echo applications, the pulse duration is an important parameter that specifies the axial resolution, and thus, shorter ultrasound pulses provide higher resolutions. However, acoustic lenses exhibit a transient response that should be considered when setting the pulse duration, as pulses shorter than the transient state duration result in degradation in the response of acoustic lenses in terms of focal intensity, focal displacement, and lateral and axial resolutions. In this work, a thorough analysis of the transient response of Fresnel Zone Plates is discussed, demonstrating that the transient state should be considered in order to achieve optimal focusing performance. Theoretical and numerical results are presented, showing very good agreement.
1-Tx/5-Rx Through-Wall UWB Switched-Antenna-Array Radar for Detecting Stationary Humans
Authors: Rittiplang Artit , Phasukkit Pattarapong
Published: November 2020

This research proposes a through-wall S-band ultra-wideband (UWB) switched-antenna-array radar scheme for detection of stationary human subjects from respiration. The proposed antenna-array radar consists of one transmitting (Tx) and five receiving antennas (Rx). The Tx and Rx antennas are of Vivaldi type with high antenna gain (10 dBi) and narrow-angle directivity. The S-band frequency (2–4 GHz) is capable of penetrating non-metal solid objects and detecting human respiration behind a solid wall. Under the proposed radar scheme, the reflected signals are algorithmically preprocessed and filtered to remove unwanted signals, and 3D signal array is converted into 2D array using statistical variance. The images are reconstructed using back-projection algorithm prior to Sinc-filtered refinement. To validate the detection performance of the through-wall UWB radar scheme, simulations are carried out and experiments performed with single and multiple real stationary human subjects and a mannequin behind the concrete wall. Although the proposed method is an odd concept, the interest of this paper is applying the 1-Tx/5-Rx UWB switched-antenna array radar with the proposed method that is capable of distinguishing between the human subjects and the mannequin behind the concrete wall.
Estimating Lower Limb Kinematics Using a Lie Group Constrained Extended Kalman Filter with a Reduced Wearable IMU Count and Distance Measurements
Authors: Sy Luke Wicent F. , Lovell Nigel H. , Redmond Stephen J.
Published: November 2020

Tracking the kinematics of human movement usually requires the use of equipment that constrains the user within a room (e.g., optical motion capture systems), or requires the use of a conspicuous body-worn measurement system (e.g., inertial measurement units (IMUs) attached to each body segment). This paper presents a novel Lie group constrained extended Kalman filter to estimate lower limb kinematics using IMU and inter-IMU distance measurements in a reduced sensor count configuration. The algorithm iterates through the prediction (kinematic equations), measurement (pelvis height assumption/inter-IMU distance measurements, zero velocity update for feet/ankles, flat-floor assumption for feet/ankles, and covariance limiter), and constraint update (formulation of hinged knee joints and ball-and-socket hip joints). The knee and hip joint angle root-mean-square errors in the sagittal plane for straight walking were 7.6±2.6∘ and 6.6±2.7∘, respectively, while the correlation coefficients were 0.95±0.03 and 0.87±0.16, respectively. Furthermore, experiments using simulated inter-IMU distance measurements show that performance improved substantially for dynamic movements, even at large noise levels (σ=0.2 m). However, further validation is recommended with actual distance measurement sensors, such as ultra-wideband ranging sensors.