bluuebunny/crossref_metadata_2025 huggingface dataset:
An Intranuclear Sodalis-Like Symbiont and Spiroplasma Coinfect the Carrot Psyllid, Bactericera trigonica (Hemiptera, Psylloidea)
Authors: Ghosh Saptarshi , Sela Noa , Kontsedalov Svetlana , Lebedev Galina , Haines Lee R. , Ghanim Murad
Published: May 2020

Endosymbionts harbored inside insects play critical roles in the biology of their insect host and can influence the transmission of pathogens by insect vectors. Bactericera trigonica infests umbelliferous plants and transmits the bacterial plant pathogen Candidatus Liberibacter solanacearum (CLso), causing carrot yellows disease. To characterize the bacterial diversity of B. trigonica, as a first step, we used PCR-restriction fragment length polymorphism (PCR-RFLP) and denaturing gradient gel electrophoresis (DGGE) analyses of 16S rDNA to identify Sodalis and Spiroplasma endosymbionts. The prevalence of both symbionts in field-collected psyllid populations was determined: Sodalis was detected in 100% of field populations, while Spiroplasma was present in 82.5% of individuals. Phylogenetic analysis using 16S rDNA revealed that Sodalis infecting B. trigonica was more closely related to symbionts infecting weevils, stink bugs and tsetse flies than to those from psyllid species. Using fluorescent in situ hybridization and immunostaining, Sodalis was found to be localized inside the nuclei of the midgut cells and bacteriocytes. Spiroplasma was restricted to the cytoplasm of the midgut cells. We further show that a recently reported Bactericera trigonica densovirus (BtDNV), a densovirus infecting B. trigonica was detected in 100% of psyllids and has reduced titers inside CLso-infected psyllids by more than two-fold compared to CLso uninfected psyllids. The findings of this study will help to increase our understanding of psyllid–endosymbiont interactions.
Soil Chemical and Microbiological Properties Are Changed by Long-Term Chemical Fertilizers That Limit Ecosystem Functioning
Authors: Bai Yong-Chao , Chang Ying-Ying , Hussain Muzammil , Lu Bin , Zhang Jun-Pei , Song Xiao-Bo , Lei Xia-Shuo , Pei Dong
Published: May 2020

Although the effects of fertilization and microbiota on plant growth have been widely studied, our understanding of the chemical fertilizers to alter soil chemical and microbiological properties in woody plants is still limited. The aim of the present study is to investigate the impact of long-term application of chemical fertilizers on chemical and microbiological properties of root-associated soils of walnut trees. The results show that soil organic matter (OM), pHkcl, total nitrogen (TN), nitrate-nitrogen (NO3−), and total phosphorus (TP) contents were significantly higher in non-fertilized soil than after chemical fertilization. The long-term fertilization led to excessive ammonium-nitrogen (NH4+) and available phosphorus (AP) residues in the cultivated soil, among which NH4+ resulted in soil acidification and changes in bacterial community structure, while AP reduced fungal diversity. The naturally grown walnut trees led to an enrichment in beneficial bacteria such as Burkholderia, Nitrospira, Pseudomonas, and Candidatus_Solibacter, as well as fungi, including Trichoderma, Lophiostoma, Phomopsis, Ilyonectria, Purpureocillium, Cylindrocladiella, Hyalorbilia, Chaetomium, and Trichoglossum. The presence of these bacterial and fungal genera that have been associated with nutrient mobilization and plant growth was likely related to the higher soil OM, TN, NO3−, and TP contents in the non-fertilized plots. These findings highlight that reduced chemical fertilizers and organic cultivation with beneficial microbiota could be used to improve economic efficiency and benefit the environment in sustainable agriculture.
Endophytes Increased Fruit Quality with Higher Soluble Sugar Production in Honeycrisp Apple (Malus pumila)
Authors: Rho Hyungmin , Van Epps Victor , Kim Soo-Hyung , Doty Sharon L.
Published: May 2020

Endophytes are fungi, bacteria, or yeast symbionts that live in the intercellular spaces or vascular tissues of host plants. Investigations indicate that endophytes isolated from the Salicaceae family (Populus and Salix) hosts provide several benefits that promote plant growth, including but not limited to di-nitrogen fixation, plant hormone production, nutrient acquisition, stress tolerance, and defense against phytopathogens. In exchange, the microorganisms receive domicile and photosynthates. Considering the known characteristics of nitrogen fixation and plant hormone production, we hypothesized that apple trees grown under nitrogen-limited conditions would show improved biometrics with endophyte inoculation. Our research objectives were to investigate the endophyte effects on plant physiology and fruiting. We examined these effects through ecophysiology metrics involving rates of photosynthesis, stomatal conductance and density, transpiration, biomass accretion, chlorophyll content and fluorescence, and fruit soluble sugar content and biomass. Our results showed evidence of the endophytes’ colonization in apple trees, decreased stomatal density, delayed leaf senescence, and increased lateral root biomass with endophytes. A highlight of the findings was a significant increase in both fruit soluble sugar content and biomass. Future research into the mechanistic underpinnings of this phenomenon stands to offer novel insights on how microbiota may alter carbohydrate metabolism under nitrogen-deficient conditions.
Systematic Review of the Respiratory Syncytial Virus (RSV) Prevalence, Genotype Distribution, and Seasonality in Children from the Middle East and North Africa (MENA) Region
Authors: Yassine Hadi M. , Sohail Muhammad U. , Younes Nadin , Nasrallah Gheyath K.
Published: May 2020

Respiratory syncytial virus (RSV) is one of the most common viruses to infect children worldwide and is the leading cause of lower respiratory tract illness (LRI) in infants. This study aimed to conduct a systematic review by collecting and reviewing all the published knowledge about the epidemiology of RSV in the Middle East and North Africa (MENA) region. Therefore, we systematically searched four databases; Embase, Medline, Scopus, and Cochrane databases from 2001 to 2019 to collect all the information related to the RSV prevalence, genotype distribution, and seasonality in children in MENA region. Our search strategy identified 598 studies, of which 83 met our inclusion criteria, which cover the past 19 years (2000–2019). Odds ratio (OR) and confidence interval (CI) were calculated to measure the association between RSV prevalence, gender, and age distribution. An overall prevalence of 24.4% (n = 17,106/69,981) of respiratory infections was recorded for RSV. The highest RSV prevalence was reported in Jordan (64%, during 2006–2007) and Israel (56%, 2005–2006). RSV A subgroup was more prevalent (62.9%; OR = 2.9, 95%CI = 2.64–3.13) than RSV B. RSV was most prevalent in children who were less than 12 months old (68.6%; OR = 4.7, 95%CI = 2.6–8.6) and was higher in males (59.6%; OR = 2.17, 95%CI = 1.2–3.8) than in female infants. Finally, the highest prevalence was recorded during winter seasons in all countries, except for Pakistan. RSV prevalence in the MENA region is comparable with the global one (24.4% vs. 22%). This first comprehensive report about RSV prevalence in the MENA region and our data should be important to guide vaccine introduction decisions and future evaluation.
Characteristics and Driving Factors of the Aerobic Denitrifying Microbial Community in Baiyangdian Lake, Xiong’an New Area
Authors: Zhou Shilei , Sun Yue , Li Zaixing , Huang Tinglin
Published: May 2020

Here, the ion-exchangeable form of nitrogen (IEF-N), weak-acid extractable form of nitrogen (WAEF-N), strong-alkali extractable form of nitrogen (SAEF-N), strong-oxidant extractable form of nitrogen (SOEF-N), residue nitrogen (Res-N), and total nitrogen (TN) showed spatial differences, and most of the sediment nitrogen fractions exhibited positive correlations in Baiyangdian Lake. High-throughput sequencing analysis revealed that the aerobic denitrification microbial community was composed of proteobacteria (42.04%–99.08%) and unclassified_bacteria (0.92%–57.92%). Moreover, the microbial community exhibited significant differences (R2 = 0.4422, P < 0.05) on the basis of the adonis analysis. T(temperature), Moisture content (MC), sediment total phosphorus (STP), ion-exchangeable form of ammonia (IEF-NH4+-N), weak-acid extractable form of ammonia (WAEF-NH4+-N), weak-acid extractable form of nitrate (WAEF-NO3−-N), and strong-alkali extractable form of ammonia (SAEF-NH4+-N) were the dominant environmental factors and explained 11.1%, 8.2%, 10.7%, 6.9%, 9.3%, 8.1%, 10.5%, 7.5%, and 7% variation, respectively, of the total variation in the microbial community. Furthermore, the network analysis showed that symbiotic relationships accounted for a major percentage of the microbial networks. The keystone aerobic denitrifying bacteria belonged to Comamonas, Rhodobacter, Achromobacter, Aeromonas, Azoarcus, Leptothrix_Burkholderiales, Pseudomonas, Thauera, unclassified_Burkholderiales, and unclassified_bacteria. The composition of the keystone aerobic denitrifying microbial community also exhibited significant differences (R2 = 0.4534, P < 0.05) on the basis of the adonis analysis. T, STP, IEF-NH4+-N, ion-exchangeable form of nitrate (IEF-NO3−-N), WAEF-NO3−-N, SAEF-NH4+-N, and TN were the dominant environmental factors that explained 8.4%, 6.2%, 4.6%, 5.9%, 5.9%, 4.5%, and 9.4% variation, respectively, of the total variation in the keystone aerobic denitrifying microbial community. The systematic investigation could provide a theoretical foundation for the evolution mechanism of the aerobic denitrifying microbial community in Baiyangdian Lake.
A Nutrigenetic Approach to Investigate the Relationship between Metabolic Traits and Vitamin D Status in an Asian Indian Population
Authors: Alathari Buthaina E. , Bodhini Dhanasekaran , Jayashri Ramamoorthy , Lakshmipriya Nagarajan , Shanthi Rani Coimbatore Subramanian , Sudha Vasudevan , Lovegrove Julie A. , Anjana Ranjit Mohan , Mohan Viswanathan , Radha Venkatesan , Pradeepa Rajendra , Vimaleswaran Karani S.
Published: May 2020

Studies in Asian Indians have examined the association of metabolic traits with vitamin D status. However, findings have been quite inconsistent. Hence, we aimed to explore the relationship between metabolic traits and 25-hydroxyvitamin D [25(OH)D] concentrations. We investigate whether this relationship was modified by lifestyle factors using a nutrigenetic approach in 545 Asian Indians randomly selected from the Chennai Urban Rural Epidemiology Study (219 normal glucose tolerant individuals, 151 with pre-diabetes and 175 individuals with type 2 diabetes). A metabolic genetic risk score (GRS) was developed using five common metabolic disease-related genetic variants. There was a significant interaction between metabolic GRS and carbohydrate intake (energy%) on 25(OH)D (Pinteraction = 0.047). Individuals consuming a low carbohydrate diet (≤62%) and those having lesser number of metabolic risk alleles (GRS ≤ 1) had significantly higher levels of 25(OH)D (p = 0.033). Conversely, individuals consuming a high carbohydrate diet despite having lesser number of risk alleles did not show a significant increase in 25(OH)D (p = 0.662). In summary, our findings show that individuals carrying a smaller number of metabolic risk alleles are likely to have higher 25(OH)D levels if they consume a low carbohydrate diet. These data support the current dietary carbohydrate recommendations of 50%–60% energy suggesting that reduced metabolic genetic risk increases 25(OH)D.
Moderate Intake of Lean Red Meat Was Associated with Lower Risk of Elevated Blood Pressure in Chinese Women: Results from the China Health and Nutrition Survey, 1991–2015
Authors: Wang Zhihong , Huang Qiumin , Wang Liusen , Jiang Hongru , Wang Yun , Wang Huijun , Zhang Jiguo , Zhai Fengying , Zhang Bing
Published: May 2020

This study aimed to examine longitudinal associations between fatty and lean, fresh red meat intake and blood pressure (BP) in Chinese adults. The data were from nine waves of the China Health and Nutrition Survey (1991–2015), a longitudinal, open cohort study. The surveys were conducted in 303 urban and rural communities of 15 provinces in China. Collected by consecutive three-day 24-h dietary recalls combined with household weighing for foods or only condiments, the diet exposure of interest was daily red meat intake and its subtypes (fatty versus lean) defined by 10-g fat content per 100 g. The main outcome was systolic blood pressure (SBP), diastolic blood pressure (DBP) and risk of elevated BP defined as having a mean of SBP ≥ 135 mmHg, DBP ≥ 85 mmHg, or taking antihypertensive medication. Three-level mixed-effect regressions showed women had SBP increases of 2.19 mmHg (95% CI: 1.07, 4.46) from a higher intake of total fresh red meat, 2.42 mmHg (95% CI: 1.18, 4.94) from a higher intake of fatty, fresh red meat, as well as 0.48 mmHg (95% CI: 0.26, 0.88) from a higher intake of lean, fresh red meat in the top tertile versus bottom one when adjusted for potential confounders. After adjusting for survey years, women with the highest tertile of lean, fresh red meat intake had a 32% lower risk of elevated BP (OR 0.68, 95%CI:0.48, 0.96) as compared with those with the first tertile (non-consumer). Fatty and lean, fresh red meat intakes were differentially associated with BP among Chinese adults. Further research is required to elicit the potential mechanism on gender-specific differential association of fatty versus lean, fresh red meat with BP.
The Impact of Glucose-Based or Lipid-Based Total Parenteral Nutrition on the Free Fatty Acids Profile in Critically Ill Patients
Authors: Skorepa Pavel , Sobotka Ondrej , Vanek Jan , Ticha Alena , Fortunato Joao , Manak Jan , Blaha Vladimir , Horacek Jan M. , Sobotka Lubos
Published: May 2020

Introduction: Our study aim was to assess how the macronutrient intake during total parenteral nutrition (TPN) modulates plasma total free fatty acids (FFAs) levels and individual fatty acids in critically ill patients. Method: Adult patients aged 18–80, admitted to the intensive care unit (ICU), who were indicated for TPN, with an expected duration of more than three days, were included in the study. Isoenergetic and isonitrogenous TPN solutions were given with a major non-protein energy source, which was glucose (group G) or glucose and lipid emulsions (Smof lipid; group L). Blood samples were collected on days 0, 1, 3, 6, 9, 14, and 28. Results: A significant decrease (p < 0.001) in total FFAs occurred in both groups with a bigger decrease in group G (p < 0.001) from day 0 (0.41 ± 0.19 mmol∙L−1) to day 28 (0.10 ± 0.07 mmol∙L−1). Increased palmitooleic acid and decreased linoleic and docosahexaenoic acids, with a trend of increased mead acid to arachidonic acid ratio, on day 28 were observed in group G in comparison with group L. Group G had an insignificant increase in leptin with no differences in the concentrations of vitamin E, triacylglycerides, and plasminogen activator inhibitor-1. Conclusion: Decreased plasma FFA in critically ill patients who receive TPN may result from increased insulin sensitivity with a better effect in group G, owing to higher insulin and glucose dosing and no lipid emulsions. It is advisable to include a lipid emulsion at the latest from three weeks of TPN to prevent essential fatty acid deficiency.
Erratum: Mangas-Sanjuán, V.; et al. Assessment of the Inter-Batch Variability of Microstructure Parameters in Topical Semisolids and Impact on the Demonstration of Equivalence. Pharmaceutics 2019, 11, 503
Authors: Mangas-Sanjuán Víctor , Pleguezuelos-Villa María , Merino-Sanjuán Matilde , Hernández Mᵃ Jesús , Nácher Amparo , García-Arieta Alfredo , Peris Daniel , Hidalgo Irene , Soler Lluís , Sallan Marta , Merino Virginia
Published: May 2020

The authors wish to make the following corrections to this paper [...]
PLGA Nanoparticles for the Intraperitoneal Administration of CBD in the Treatment of Ovarian Cancer: In Vitro and In Ovo Assessment
Authors: Fraguas-Sánchez Ana I. , Torres-Suárez Ana I. , Cohen Marie , Delie Florence , Bastida-Ruiz Daniel , Yart Lucile , Martin-Sabroso Cristina , Fernández-Carballido Ana
Published: May 2020

The intraperitoneal administration of chemotherapeutics has emerged as a potential route in ovarian cancer treatment. Nanoparticles as carriers for these agents could be interesting by increasing the retention of chemotherapeutics within the peritoneal cavity. Moreover, nanoparticles could be internalised by cancer cells and let the drug release near the biological target, which could increase the anticancer efficacy. Cannabidiol (CBD), the main nonpsychotropic cannabinoid, appears as a potential anticancer drug. The aim of this work was to develop polymer nanoparticles as CBD carriers capable of being internalised by ovarian cancer cells. The drug-loaded nanoparticles (CBD-NPs) exhibited a spherical shape, a particle size around 240 nm and a negative zeta potential (−16.6 ± 1.2 mV). The encapsulation efficiency was high, with values above 95%. A controlled CBD release for 96 h was achieved. Nanoparticle internalisation in SKOV-3 epithelial ovarian cancer cells mainly occurred between 2 and 4 h of incubation. CBD antiproliferative activity in ovarian cancer cells was preserved after encapsulation. In fact, CBD-NPs showed a lower IC50 values than CBD in solution. Both CBD in solution and CBD-NPs induced the expression of PARP, indicating the onset of apoptosis. In SKOV-3-derived tumours formed in the chick embryo model, a slightly higher—although not statistically significant—tumour growth inhibition was observed with CBD-NPs compared to CBD in solution. To sum up, poly-lactic-co-glycolic acid (PLGA) nanoparticles could be a good strategy to deliver CBD intraperitoneally for ovarian cancer treatment.
MERS-CoV Spike Protein Vaccine and Inactivated Influenza Vaccine Formulated with Single Strand RNA Adjuvant Induce T-Cell Activation through Intranasal Immunization in Mice
Authors: Kim Hye-Jung , Kwak Hye Won , Kang Kyung Won , Bang Yoo-Jin , Lee Yu-Sun , Park Hyeong-Jun , Kim Jae-Yong , Park Hyo-Jung , Hwang Kyung-Ah , Lee Sang-Myeong , Nam Jae-Hwan
Published: May 2020

The effectiveness of vaccines is enhanced by adding adjuvants. Furthermore, the selection of an inoculation route depends on the type of adjuvant used and is important for achieving optimum vaccine efficacy. We investigated the immunological differences between two types of vaccines—spike protein from the Middle East respiratory syndrome virus and inactivated influenza virus vaccine, in combination with a single-stranded RNA adjuvant—administered through various routes (intramuscular, intradermal, and intranasal) to BALB/c mice. Intramuscular immunization with the RNA adjuvant-formulated spike protein elicited the highest humoral immune response, characterized by IgG1 and neutralizing antibody production. Although intranasal immunization did not elicit a humoral response, it showed extensive T-cell activation through large-scale induction of interferon-γ- and interleukin-2-secreting cells, as well as CD4+ T-cell activation in mouse splenocytes. Moreover, only intranasal immunization induced IgA production. When immunized with the inactivated influenza vaccine, administration of the RNA adjuvant via all routes led to protection after viral challenge, regardless of the presence of a vaccine-specific antibody. Therefore, the inoculation route should depend on the type of immune response needed; i.e., the intramuscular route is suitable for eliciting a humoral immune response, whereas the intranasal route is useful for T-cell activation and IgA induction.
Biotin-Decorated PAMAM G4.5 Dendrimer Nanoparticles to Enhance the Delivery, Anti-Proliferative, and Apoptotic Effects of Chemotherapeutic Drug in Cancer Cells
Authors: Hanurry Endiries Yibru , Mekonnen Tefera Worku , Andrgie Abegaz Tizazu , Darge Haile Fentahun , Birhan Yihenew Simegniew , Hsu Wei-Hsin , Chou Hsiao-Ying , Cheng Chih-Chia , Lai Juin-Yih , Tsai Hsieh-Chih
Published: May 2020

Biotin receptors are overexpressed by various types of solid cancer cells and play a significant role in tumor metabolism, growth, and metastasis. Thus, targeting the biotin receptors on tumor cells may enhance the efficiency and reduce the side-effects of chemotherapy. The aim of this study was to develop a biotin-coupled poly(amido)amine (PAMAM) (PG4.5) dendrimer nanoparticle to enhance the tumor-specific delivery and intracellular uptake of anticancer drugs via receptor-mediated endocytosis. We modified PG4.5 with diethylenetriamine (DETA) followed by biotin via an amide bond and characterized the resulting PG4.5-DETA-biotin nanoparticles by 1H NMR, FTIR, and Raman spectroscopy. Loading and releasing of gemcitabine (GEM) from PG4.5-DETA-biotin were evaluated by UV–Visible spectrophotometry. Cell viability and cellular uptake were examined by MTT assay and flow cytometry to assess the biocompatibility, cellular internalization efficiency and antiproliferative activity of PG4.5-DETA-biotin/GEM. Gemcitabine-loaded PG4.5-DETA-biotin nanoparticles were spherical with a particle size of 81.6 ± 6.08 nm and zeta potential of 0.47 ± 1.25 mV. Maximum drug-loading content and encapsulation efficiency were 10.84 ± 0.16% and 47.01 ± 0.71%, respectively. Nearly 60.54 ± 1.99% and 73.96 ± 1.14% of gemcitabine was released from PG4.5-DETA-biotin/GEM nanoparticles after 48 h at the acidic pH values of 6.5 and 5, respectively. Flow cytometry and fluorescence microscopy of cellular uptake results revealed PG4.5-DETA-biotin/GEM nanoparticles selectively targeted cancer cells in vitro. Cytotoxicity assays demonstrated gemcitabine-loaded PG4.5-DETA-biotin significantly reduced cell viability and induced apoptosis in HeLa cells. Thus, biotin-coupled PG4.5-DETA nanocarrier could provide an effective, targeted drug delivery system and selectively convey gemcitabine into tumor cells.
Pharmacists and Contraception in the Inpatient Setting
Authors: Ciriello Domenique , Cieri-Hutcherson Nicole
Published: May 2020

The choice of contraceptive method should be based on patient specific factors, patient preference, and method-specific properties. In this article, we review opportunities for an inpatient clinical pharmacist to assist in the selection and counseling of contraceptives in hospitalized patients. An inpatient pharmacist has the opportunity to discuss various contraceptive methods with the patient, ensuring an appropriate method is used after discharge, which is especially important after the occurrence of a contraception-related adverse effect or contraindication to certain contraceptive methods. Barriers, such as formulary restrictions, can limit inpatient initiation of contraceptive therapy while hospitalized, but pharmacists can provide education on appropriate alternatives. Inpatient clinical pharmacists can also make recommendations for contraceptive methods in special populations. It is crucial to select an appropriate therapy in patients with an underlying medical condition, such as those with active or history of breast cancer, psychiatric disorder, or thrombophilia, as inappropriate therapy can cause an increased risk of harm. Pharmacists can assist in contraceptive counseling, evaluating for drug-drug and drug-disease interactions, and recommending the most appropriate therapy in special populations. An inpatient pharmacist has the opportunity to interact with the medical team and assist in navigation of teratogenic medication use and Risk Evaluation and Mitigation Strategies.
Thermal Conductivity of Polyisoprene and Polybutadiene from Molecular Dynamics Simulations and Transient Measurements
Authors: Vasilev Aleksandr , Lorenz Tommy , Breitkopf Cornelia
Published: May 2020

The thermal conductivities of untreated polyisoprene and polybutadiene were calculated by molecular dynamics (MD) simulations using a Green-Kubo approach between −10 °C and 50 °C at atmospheric pressure. For comparison, the thermal conductivities of untreated polyisoprene with a molecular weight of 54,000 g/mol and untreated polybutadiene with a molecular weight of 45,000 g/mol were measured by the transient hot wire method in similar conditions. The simulation results of both polymers are in good agreement with the experimental data. We observed that the MD simulations slightly overestimate the thermal conductivity due to the chosen force field description. Details are discussed in the paper.
Biodegradable Polylactide–Poly(3-Hydroxybutyrate) Compositions Obtained via Blending under Shear Deformations and Electrospinning: Characterization and Environmental Application
Authors: Rogovina Svetlana , Zhorina Lubov , Gatin Andrey , Prut Eduard , Kuznetsova Olga , Yakhina Anastasia , Olkhov Anatoliy , Samoylov Naum , Grishin Maxim , Iordanskii Alexey , Berlin Alexandr
Published: May 2020

Compositions of polylactide (PLA) and poly(3-hydroxybutyrate) (PHB) thermoplastic polyesters originated from the nature raw have been obtained by blending under shear deformations and electrospinning methods in the form of films and nanofibers as well as unwoven nanofibrous materials, respectively. The degrees of crystallinity calculated on the base of melting enthalpies and thermal transition temperatures for glassy state, cold crystallization, and melting point for individual biopolymers and ternary polymer blends PLA-PHB- poly(ethyleneglycol) (PEG) have been evaluated. It has been shown that the mechanical properties of compositions depend on the presence of plasticizers PEG with different molar masses in interval of 400–1000. The experiments on the action of mold fungi on the films have shown that PHB is a fully biodegradable polymer unlike PLA, whereas the biodegradability of the obtained composites is determined by their composition. The sorption activity of PLA–PHB nanofibers and unwoven nanofibrous PLA–PHB composites relative to water and oil has been studied and the possibility of their use as absorbents in wastewater treatment from petroleum products has been demonstrated.
A Review on Barrier Properties of Poly(Lactic Acid)/Clay Nanocomposites
Authors: Singha Shuvra , Hedenqvist Mikael S.
Published: May 2020

Poly(lactic acid) (PLA) is considered to be among the best biopolymer substitutes for the existing petroleum-based polymers in the field of food packaging owing to its renewability, biodegradability, non-toxicity and mechanical properties. However, PLA displays only moderate barrier properties to gases, vapors and organic compounds, which can limit its application as a packaging material. Hence, it becomes essential to understand the mass transport properties of PLA and address the transport challenges. Significant improvements in the barrier properties can be achieved by incorporating two-dimensional clay nanofillers, the planes of which create tortuosity to the diffusing molecules, thereby increasing the effective length of the diffusion path. This article reviews the literature on barrier properties of PLA/clay nanocomposites. The important PLA/clay nanocomposite preparation techniques, such as solution intercalation, melt processing and in situ polymerization, are outlined followed by an extensive account of barrier performance of nanocomposites drawn from the literature. Fundamentals of mass transport phenomena and the factors affecting mass transport are also presented. Furthermore, mathematical models that have been proposed/used to predict the permeability in polymer/clay nanocomposites are reviewed and the extent to which the models are validated in PLA/clay composites is discussed.
Studying the Applicability of X-Band SAR Data to the Network-Scale Mapping of Pavement Roughness on US Roads
Authors: Meyer Franz J. , Ajadi Olaniyi A. , Hoppe Edward J.
Published: May 2020

The traveling public judges the quality of a road mostly by its roughness and/or ride quality. Hence, mapping, monitoring, and maintaining adequate pavement smoothness is of high importance to State Departments of Transportation in the US. Current methods rely mostly on in situ measurements and are, therefore, time consuming and costly when applied at the network scale. This paper studies the applicability of satellite radar remote sensing data, specifically, high-resolution Synthetic Aperture Radar (SAR) data acquired at X-band, to the network-wide mapping of pavement roughness of roads in the US. Based on a comparison of high-resolution X-band Cosmo-SkyMed images with road roughness data in the form of International Roughness Index (IRI) measurements, we found that X-band radar brightness generally increases when pavement roughness worsens. Based on these findings, we developed and inverted a model to distinguish well maintained road segments from segments in need of repair. Over test sites in Augusta County, VA, we found that our classification scheme reaches an overall accuracy of 92.6%. This study illustrates the capacity of X-band SAR for pavement roughness mapping and suggests that incorporating SAR into DOT operations could be beneficial.
Can InSAR Coherence and Closure Phase Be Used to Estimate Soil Moisture Changes?
Authors: Eshqi Molan Yusuf , Lu Zhong
Published: May 2020

We studied the influence of the statistical properties of soil moisture changes on the Interferometric Synthetic Aperture Radar (InSAR) coherence and closure phase to determine whether the InSAR coherence and closure phase can be used to estimate soil moisture changes. We generated semi-synthetic multi-looked interferograms by pairing n real single-looked pixels of an observed SAR image with n synthetic single-looked pixels. The synthetic SAR data are generated from the real SAR data by applying soil moisture changes with a pre-defined mean and standard deviation of changes. Our results show that the diversity of soil moisture changes within the multi-look window gives rise to decorrelation, a multi-looked phase artifact, and a non-zero phase triplet. The decorrelation and closure phase increase by enlarging the diversity of soil moisture changes. We also showed that non-soil moisture changes can lead to larger decorrelations and closure phases. Furthermore, the diversity of phase changes, decorrelation, and closure phases are correlated with land cover type. We concluded that the closure phase and coherence are independent of the magnitude of soil moisture changes and are inappropriate tools to estimate soil moisture changes. Coherence, however, can be used as a proxy for soil moisture changes if the diversity and magnitude of soil moisture changes within a multi-looked pixel are strongly correlated.
Short-Term Ecogeomorphic Evolution of a Fluvial Delta from Hindcasting Intertidal Marsh-Top Elevations (HIME)
Authors: Smith Brittany C. , Moffett Kevan B. , Mohrig David
Published: May 2020

Understanding how delta islands grow and change at contemporary, interannual timescales remains a key scientific goal and societal need, but the high-resolution, high frequency morphodynamic data that would be most useful for this are as yet logistically prohibitive. The recorded water levels needed for relative elevation analysis are also often lacking. This paper presents a new approach for hindcasting intertidal marsh-top elevations (HIME) to resolve ecogeomorphic change, even in a young, rapidly changing fluvial delta setting, at sub-decadal temporal resolution and at the spatial resolution of widely available optical remote sensing imagery (e.g., 30 m Landsat). The HIME method first calculates: (i) the probability of land exposure in a set of historical imagery from a user-defined discrete timespan (e.g., months or years); (ii) the probability of water level non-exceedance from water level records, which need not be complete nor coincident with the imagery; and (iii) the systematic variation in local mean water level with distance along the primary hydraulic gradient. The HIME method then combines these inputs to estimate a marsh-top elevation map for each historical timespan of interest. The method was developed, validated, applied, and results analyzed to investigate time-lapse evolution of the Wax Lake Delta in Louisiana, USA, every three years, over two decades (1993–2013). The hindcast maps of delta island extents and elevations evidenced ecogeomorphic system self-organization around four stable attractors, or elevation platforms, at about −0.3 m (subtidal), 0.2 m, 0.4 m, and 0.9 m (supratidal) NAVD88. The HIME results also yielded a time series of net subaerial sediment accumulation, and specific locations and magnitudes of gains and losses, at scales from 30 m to delta-wide (~100 km3) and 6 to 21 years. Average subaerial net sediment accumulation at the Wax Lake Delta (WLD) was estimated as 0.6 cm/yr during the study period. Finally, multiple linear regression models were successfully trained on the HIME elevation maps to model evolving delta island morphologies based on simple geometric factors, such as distance down-delta and position on a delta island; the models also successfully reproduced an average delta topset slope of 1.4 cm. Overall, this study’s development and application of the HIME method added detailed insights to recent, transient ecogeomorphological change at the WLD, and demonstrated the potential of the new approach for accurately reconstructing past intertidal topographies and dynamic change.
Railway Point-Operating Machine Fault Detection Using Unlabeled Signaling Sensor Data
Authors: Mistry Pritesh , Lane Phil , Allen Paul
Published: May 2020

In this study, we propose a methodology for the identification of potential fault occurrences of railway point-operating machines, using unlabeled signal sensor data. Data supplied by Network Rail, UK, is processed using a fast Fourier transform signal processing approach, coupled with the mean and max current levels to identify potential faults in point-operating machines. The method developed can dynamically adapt to the behavioral characteristics of individual point-operating machines, thereby providing bespoke condition monitoring capabilities in situ and in real time. The work described in this paper is not unique to railway point-operating machines, rather the data pre-processing and methodology is readily applicable to any motorized device fitted with current sensing capabilities. The novelty of our approach is that it does not require pre-labelled data with historical fault occurrences and therefore closely resembles problems of the real world, with application for smart city infrastructure. Lastly, we demonstrate the problems faced with handling such data and the capability of our methodology to dynamically adapt to diverse data presentations.
Potential of Pléiades and WorldView-3 Tri-Stereo DSMs to Represent Heights of Small Isolated Objects
Authors: Loghin Ana-Maria , Otepka-Schremmer Johannes , Pfeifer Norbert
Published: May 2020

High-resolution stereo and multi-view imagery are used for digital surface model (DSM) derivation over large areas for numerous applications in topography, cartography, geomorphology, and 3D surface modelling. Dense image matching is a key component in 3D reconstruction and mapping, although the 3D reconstruction process encounters difficulties for water surfaces, areas with no texture or with a repetitive pattern appearance in the images, and for very small objects. This study investigates the capabilities and limitations of space-borne very high resolution imagery, specifically Pléiades (0.70 m) and WorldView-3 (0.31 m) imagery, with respect to the automatic point cloud reconstruction of small isolated objects. For this purpose, single buildings, vehicles, and trees were analyzed. The main focus is to quantify their detectability in the photogrammetrically-derived DSMs by estimating their heights as a function of object type and size. The estimated height was investigated with respect to the following parameters: building length and width, vehicle length and width, and tree crown diameter. Manually measured object heights from the oriented images were used as a reference. We demonstrate that the DSM-based estimated height of a single object strongly depends on its size, and we quantify this effect. Starting from very small objects, which are not elevated against their surroundings, and ending with large objects, we obtained a gradual increase of the relative heights. For small vehicles, buildings, and trees (lengths <7 pixels, crown diameters <4 pixels), the Pléiades-derived DSM showed less than 20% or none of the actual object’s height. For large vehicles, buildings, and trees (lengths >14 pixels, crown diameters >7 pixels), the estimated heights were higher than 60% of the real values. In the case of the WorldView-3 derived DSM, the estimated height of small vehicles, buildings, and trees (lengths <16 pixels, crown diameters <8 pixels) was less than 50% of their actual height, whereas larger objects (lengths >33 pixels, crown diameters >16 pixels) were reconstructed at more than 90% in height.
Dynamic Frame Update Policy for UHF RFID Sensor Tag Collisions
Authors: Arjona Laura , Landaluce Hugo , Perallos Asier , Onieva Enrique
Published: May 2020

The current growing demand for low-cost edge devices to bridge the physical–digital divide has triggered the growing scope of Radio Frequency Identification (RFID) technology research. Besides object identification, researchers have also examined the possibility of using RFID tags for low-power wireless sensing, localisation and activity inference. This paper focuses on passive UHF RFID sensing. An RFID system consists of a reader and various numbers of tags, which can incorporate different kinds of sensors. These sensor tags require fast anti-collision protocols to minimise the number of collisions with the other tags sharing the reader’s interrogation zone. Therefore, RFID application developers must be mindful of anti-collision protocols. Dynamic Frame Slotted Aloha (DFSA) anti-collision protocols have been used extensively in the literature because EPCglobal Class 1 Generation 2 (EPC C1G2), which is the current communication protocol standard in RFID, employs this strategy. Protocols under this category are distinguished by their policy for updating the transmission frame size. This paper analyses the frame size update policy of DFSA strategies to survey and classify the main state-of-the-art of DFSA protocols according to their policy. Consequently, this paper proposes a novel policy to lower the time to read one sensor data packet compared to existing strategies. Next, the novel anti-collision protocol Fuzzy Frame Slotted Aloha (FFSA) is presented, which applies this novel DFSA policy. The results of our simulation confirm that FFSA significantly decreases the sensor tag read time for a wide range of tag populations when compared to earlier DFSA protocols thanks to the proposed frame size update policy.
Gradient Estimator-Based Amplitude Estimation for Dynamic Mode Atomic Force Microscopy: Small-Signal Modeling and Tuning
Authors: Ahmed Hafiz , Benbouzid Mohamed
Published: May 2020

Atomic force microscopy (AFM) plays an important role in nanoscale imaging application. AFM works by oscillating a microcantilever on the surface of the sample being scanned. In this process, estimating the amplitude of the cantilever deflection signal plays an important role in characterizing the topography of the surface. Existing approaches on this topic either have slow dynamic response e.g., lock-in-amplifier or high computational complexity e.g., Kalman filter. In this context, gradient estimator can be considered as a trade-off between fast dynamic response and high computational complexity. However, no constructive tuning rule is available in the literature for gradient estimator. In this paper, we consider small-signal modeling and tuning of gradient estimator. The proposed approach greatly simplifies the tuning procedure. Numerical simulation and experimental results are provided to demonstrate the suitability of the proposed tuning procedure.
S6AE: Securing 6LoWPAN Using Authenticated Encryption Scheme
Authors: Tanveer Muhammad , Abbas Ghulam , Abbas Ziaul Haq , Waqas Muhammad , Muhammad Fazal , Kim Sunghwan
Published: May 2020

IPv6 over Low Power Wireless Personal Area Networks (6LoWPAN) has an ample share in the Internet of Things. Sensor nodes in 6LoWPAN collect vital information from the environment and transmit to a central server through the public Internet. Therefore, it is inevitable to secure communications and allow legitimate sensor nodes to access network resources. This paper presents a lightweight Authentication and Key Exchange (AKE) scheme for 6LoWPAN using an authenticated encryption algorithm and hash function. Upon successful authentication, sensor nodes and the central server can establish the secret key for secure communications. The proposed scheme ensures header verification during the AKE process without using IP security protocol and, thus, has low communication and computational overheads. The logical correctness of the proposed scheme is validated through Burrows–Abadi–Needham logic. Furthermore, automatic security analyses by using AVISPA illustrate that the proposed scheme is resistant to various malicious attacks in 6LoWPANs.
Deep Learning-Based Real-Time Auto Classification of Smartphone Measured Bridge Vibration Data
Authors: Shrestha Ashish , Dang Ji
Published: May 2020

In this study, a simple and customizable convolution neural network framework was used to train a vibration classification model that can be integrated into the measurement application in order to realize accurate and real-time bridge vibration status on mobile platforms. The inputs for the network model are basically the multichannel time-series signals acquired from the built-in accelerometer sensor of smartphones, while the outputs are the predefined vibration categories. To verify the effectiveness of the proposed framework, data collected from long-term monitoring of bridge were used for training a model, and its classification performance was evaluated on the test set constituting the data collected from the same bridge but not used previously for training. An iOS application program was developed on the smartphone for incorporating the trained model with predefined classification labels so that it can classify vibration datasets measured on any other bridges in real-time. The results justify the practical feasibility of using a low-latency, high-accuracy smartphone-based system amid which bottlenecks of processing large amounts of data will be eliminated, and stable observation of structural conditions can be promoted.
Fabrication of Microbolometer Arrays Based on Polymorphous Silicon–Germanium
Authors: Jimenez Ricardo , Moreno Mario , Torres Alfonso , Morales Alfredo , Ponce Arturo , Ferrusca Daniel , Rangel-Magdaleno Jose , Castro-Ramos Jorge , Hernandez-Perez Julio , Cano Eduardo
Published: May 2020

This work reports the development of arrays of infrared sensors (microbolometers) using a hydrogenated polymorphous silicon–germanium alloy (pm-SixGe1-x:H). Basically, polymorphous semiconductors consist of an amorphous semiconductor matrix with embedded nanocrystals of about 2–3 nm. The pm-SixGe1-x:H alloy studied has a high temperature coefficient of resistance (TCR) of 4.08%/K and conductivity of 1.5 × 10−5 S∙cm−1. Deposition of thermosensing film was made by plasma-enhanced chemical vapor deposition (PECVD) at 200 °C, while the area of the devices is 50 × 50 μm2 with a fill factor of 81%. Finally, an array of 19 × 20 microbolometers was packaged for electrical characterization. Voltage responsivity values were obtained in the range of 4 × 104 V/W and detectivity around 2 × 107 cm∙Hz1/2/W with a polarization current of 70 μA at a chopper frequency of 30 Hz. A minimum value of 2 × 10−10 W/Hz1/2 noise equivalent power was obtained at room temperature. In addition, it was found that all the tested devices responded to incident infrared radiation, proving that the structure and mechanical stability are excellent.
Research on Focal Length Measurement Scheme of Self-Collimating Optical Instrument Based on Double Grating
Authors: Yang Wenchang , Wang Zhiqian , Shen Chengwu , Liu Yusheng , Liu Shaojin , Li Qinwen , Du Wen , Song Zhuoda
Published: May 2020

In this paper, we propose a scheme for measuring the focal length of a collimating optical instrument. First, a mathematical model for measuring the focal length of a collimator with double gratings is derived based on the moiré fringe formula and the principles of geometric optics. Mathematical simulation shows that a slight difference in the focal length of two collimators has an important influence on the imaging law of moiré fringes. Our solution has a good resolution ability for focal length differences within 5‰, especially in the small angle range below 4°. Thus, the focal length of collimators can be measured by the amplification of the slight difference. Further, owing to the relative reference measurement, the measurement resolution at the symmetrical position of focal length is poor. Then, in the designed experiment, a corresponding moiré image at different angles is acquired using collimators with known focal length. The experimental results indicate that the root mean square error (RMSE) of the collimator corresponding to grating angles of 2°–4° is better than 4.7‰, indicating an ideal measurement accuracy of the proposed scheme. This work demonstrates that our proposed scheme can achieve an ideal accuracy in the measurement of a symmetrical optical path.
Explora: Interactive Querying of Multidimensional Data in the Context of Smart Cities
Authors: Ordonez-Ante Leandro , Van Seghbroeck Gregory , Wauters Tim , Volckaert Bruno , De Turck Filip
Published: May 2020

Citizen engagement is one of the key factors for smart city initiatives to remain sustainable over time. This in turn entails providing citizens and other relevant stakeholders with the latest data and tools that enable them to derive insights that add value to their day-to-day life. The massive volume of data being constantly produced in these smart city environments makes satisfying this requirement particularly challenging. This paper introduces Explora, a generic framework for serving interactive low-latency requests, typical of visual exploratory applications on spatiotemporal data, which leverages the stream processing for deriving—on ingestion time—synopsis data structures that concisely capture the spatial and temporal trends and dynamics of the sensed variables and serve as compacted data sets to provide fast (approximate) answers to visual queries on smart city data. The experimental evaluation conducted on proof-of-concept implementations of Explora, based on traditional database and distributed data processing setups, accounts for a decrease of up to 2 orders of magnitude in query latency compared to queries running on the base raw data at the expense of less than 10% query accuracy and 30% data footprint. The implementation of the framework on real smart city data along with the obtained experimental results prove the feasibility of the proposed approach.