bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization of the Conceptual Design of a Multistage Rocket Launcher
Authors: Orgeira-Crespo Pedro , Rey Guillermo , Ulloa Carlos , Garcia-Luis Uxia , Rouco Pablo , Aguado-Agelet Fernando
Published: May 2022

The design of a vehicle launch comprises many factors, including the optimization of the climb path and the distribution of the mass in stages. The optimization process has been addressed historically from different points of view, using proprietary software solutions to obtain an ideal mass distribution among stages. In this research, we propose software for the separate optimization of the trajectory of a launch rocket, maximizing the payload weight and the global design, while varying the power plant selection. The launch is mathematically modeled considering its propulsive, gravitational, and aerodynamical aspects. The ascent trajectory is optimized by discretizing the trajectory using structural and physical constraints, and the design accounts for the mass and power plant of each stage. The optimization algorithm is checked against various real rockets and other modeling algorithms, obtaining differences of up to 9%.
Biotribological Characteristic of Peanut Harvesting Impact-Friction Contact under Different Conditions
Authors: Zhang Peng , Xu Hongbo , Zhuo Xiaoru , Hu Zhichao , Lian Chenglong , Wang Bing
Published: May 2022

Although cutting flow peanut-picking is the main peanut harvesting method, it has the problems of a large harvest loss and a high damage rate of peanut shells. The analysis of impact-friction contact characteristics during peanut fruit picking is crucial to illustrate peanut fruit picking damage. A typical peanut variety, “Dabaisha”, was considered in this study. The characteristics of peanut-picking impact-friction were studied using a peanut-picking impact-friction test bench under different conditions. An orthogonal test with three factors and levels was performed after the single-factor condition was determined. The apparent morphologies of peanut shells before and after the collision and friction tests were compared and analyzed using micro-computed tomography, white-light interferometry, and optical microscopy, whereas the impact-friction damage characteristics of peanuts under the influence of various factors were discussed. The results show that the orders of influence of the coefficient of friction of peanuts and wear loss of peanut pods were as follows: invasion depth > moisture content > contact linear velocity and moisture content > invasion depth > contact linear velocity, respectively. The experimental results and discussion in this study can provide a data reference for developing and designing peanut mechanization production equipment.
Antagonism and Antimicrobial Capacity of Epiphytic and Endophytic Bacteria against the Phytopathogen Xylella fastidiosa
Authors: Mourou Marwa , Hanani Arafat , D’Onghia Anna Maria , Davino Salvatore Walter , Balestra Giorgio Mariano , Valentini Franco
Published: May 2022

Olive quick decline syndrome (OQDS), which is caused by Xylella fastidiosa, poses a severe threat to the agriculture of Mediterranean countries and causes severe damage to the olive trees in Italy. Since no effective control measures are currently available, the objective of this study was the screening of antagonistic bacteria that are potentially deployable as biocontrol agents against X. fastidiosa. Therefore, two approaches were used, i.e., the evaluation of the antagonistic activity of (i) endophytic bacteria isolated from two different cultivars of olive trees (Leccino and Ogliarola salentina) and (ii) epiphytic bacteria isolated from the phyllospheres of different host plant species of X. fastidiosa. In vitro dual culture tests showed that 12 out of 200 isolates inhibited X. fastidiosa growth, with appearances of clear zones between 4.0 and 38.6 mm. 16S rRNA gene sequencing revealed different species of the genera Paenibacillus, Bacillus, Pantoea, Microbacterium, Stenotrophomonas, Delftia, and Pseudomonas. Furthermore, an investigation for antimicrobial activity identified 5 out of the 12 antagonistic bacteria, Paenibacillus rigui, Bacillus subtilis, Bacillus pumilus, Microbacterium oxydans, and Stenotrophomonas rhizophila, that were able to produce culture filtrates with inhibitory activities. Our results are promising for further investigation to develop an eco-sustainable strategy to control X. fastidiosa using biocontrol agents or their secreted metabolites.
Duodenal Metabolic Profile Changes in Heat-Stressed Broilers
Authors: Dridi Jalila S. , Greene Elizabeth S. , Maynard Craig W. , Brugaletta Giorgio , Ramser Alison , Christopher Courtney J. , Campagna Shawn R. , Castro Hector F. , Dridi Sami
Published: May 2022

Heat stress (HS) is devastating to poultry production sustainability worldwide. In addition to its adverse effects on growth, welfare, meat quality, and mortality, HS alters the gut integrity, leading to dysbiosis and leaky gut syndrome; however, the underlying mechanisms are not fully defined. Here, we used a high-throughput mass spectrometric metabolomics approach to probe the metabolite profile in the duodenum of modern broilers exposed to acute (AHS, 2 h) or chronic cyclic (CHS, 8 h/day for 2 weeks) HS in comparison with thermoneutral (TN) and pair-fed birds. Ultra high performance liquid chromatography coupled with high resolution mass spectrometry (UHPLC–HRMS) identified a total of 178 known metabolites. The trajectory analysis of the principal component analysis (PCA) score plots (both 2D and 3D maps) showed clear separation between TN and each treated group, indicating a unique duodenal metabolite profile in HS birds. Within the HS groups, partial least squares discriminant analysis (PLS-DA) displayed different clusters when comparing metabolite profiles from AHS and CHS birds, suggesting that the metabolite signatures were also dependent on HS duration. To gain biologically related molecule networks, the above identified duodenal metabolites were mapped into the Ingenuity Pathway Analysis (IPA) knowledge-base and analyzed to outline the most enriched biological functions. Several common and specific top canonical pathways were generated. Specifically, the adenosine nucleotide degradation and dopamine degradation pathways were specific for the AHS group; however, the UDP-D-xylose and UDP-D-glucuronate biosynthesis pathways were generated only for the CHS group. The top diseases enriched by the IPA core analysis for the DA metabolites, including cancer, organismal (GI) injury, hematological, cardiovascular, developmental, hereditary, and neurological disorders, were group-specific. The top altered molecular and cellular functions were amino acid metabolism, molecular transport, small molecule biochemistry, protein synthesis, cell death and survival, and DNA damage and repair. The IPA-causal network predicted that the upstream regulators (carnitine palmitoyltransferase 1B, CPT1B; histone deacetylase 11, HDAC11; carbonic anhydrase 9, CA9; interleukin 37, IL37; glycine N-methyl transferase, GNMT; GATA4) and the downstream mediators (mitogen-activated protein kinases, MAPKs; superoxide dismutase, SOD) were altered in the HS groups. Taken together, these data showed that, independently of feed intake depression, HS induced significant changes in the duodenal metabolite profile in a duration-dependent manner and identified a potential duodenal signature for HS.
Molecular Characterization of 18S rDNA, ITS-1, ITS-2, and COI from Eimeria christenseni and E. arloingi in Goats from Shaanxi Province, Northwestern China
Authors: Liang Gaoxing , Yang Xin , Liu Ding , Li Yuan , Wang Junwei , Chen Xi , Zhao Guanghui , Song Junke
Published: May 2022

Coccidiosis caused by Eimeria is one of the most common and significant diseases in goats, leading to serious economic losses in the development of the goat industry. Although several genetic loci, such as 18S rDNA, ITS-1, ITS-2, and COI, have been applied in the molecular characterization of Eimeria in chicken, rabbits, turkey, and wildlife, little is known about these molecular markers of Eimeria in goats. In the present study, we isolated purified oocysts of highly pathogenic Eimeriaarloingi and Eimeria christenseni from fecal samples of goats in Shaanxi province, China, and then subjected these purified oocysts to genomic DNA isolation, PCR amplification, and sequencing of 18S rDNA, ITS-1, ITS-2, and COI loci of Eimeria arloingi and Eimeria christenseni. Finally, the obtained sequences were used for phylogenetic analysis of Eimeria species in goats and other livestock. The lengths of the 18S rDNA, ITS-1, ITS-2, and COI were 1790 bp, 403 bp, 584 bp, and 1268 bp for E. arloingi and 1796 bp, 386 bp, 565 bp, and 1268 bp for E. christenseni, respectively. The phylogenetical analysis based on 18S rDNA indicated that E. christenseni and E. arloingi were the most closely related to ovine Eimeria, followed by E. bovis, E. ellipsoidalis, and E. zuernii from cattle. The phylogenetical analysis based on ITS-1 and ITS-2 could not effectively distinguish ovine Eimeria from caprine Eimeria. The phylogenetical analysis based on the COI locus could effectively distinguish between Eimeria species from goats and cattle, but it was ineffective in distinguishing between Eimeria species from sheep and goats. To the best of our knowledge, this is the first characterization of 18S rDNA, ITS-1, ITS-2, and COI in E. arloingi and E. christenseni; it can provide useful genetic markers for molecular epidemiological and population genetic studies on E. arloingi and E. christenseni in goats and contribute to the prevention and control of goat coccidiosis.
The Activity of Plant-Derived Ren’s Oligopeptides-1 against the Pseudorabies Virus
Authors: Xiao Danmei , He Yu , Xiao Qin , Cai Luxia , Wang Haoqi , Reheman Aikebaier , Xiao Ke
Published: May 2022

Newly synthesized Ren’s oligopeptides-1 was found to have an antiviral effect in clinical trials, and the purpose of this study was to further demonstrate the antiviral activity of Ren’s oligopeptides-1 against the PRV 152-GFP strain. We used the real-time cell analysis system (RTCA) to detect the cytotoxicity of different concentrations of Ren’s oligopeptides-1. We then applied high content screening (HCS) to detect the antiviral activity of Ren’s oligopeptides-1 against PRV. Meanwhile, the fluorescence signal of the virus was collected in real time and the expression levels of the related genes in the PK15 cells infected with PRV were detected using real-time PCR. At the mRNA level, we discovered that, at a concentration of 6 mg/mL, Ren’s oligopeptides-1 reduced the expression of pseudorabies virus (PRV) genes such as IE180, UL18, UL54, and UL21 at a concentration of 6 mg/mL. We then determined that Ren’s oligopeptides-1 has an EC50 value of 6 mg/mL, and at this level, no cytotoxicity was observed.
De Novo Assembly of the Dirofilaria immitis Genome by Long-Read Nanopore-Based Sequencing Technology on an Adult Worm from a Canine Cardiopulmonary Dirofilariosis Case
Authors: Gomes-de-Sá Sónia , Barradas Patrícia , Queirós-Reis Luís , Matas Isabel M. , Amorim Irina , Cardoso Luís , Muñoz-Mérida Antonio , Mesquita João R.
Published: May 2022

Dirofilaria immitis is a zoonotic parasitic nematode that infects domestic and wild canids, among its vertebrate hosts. The genetic analysis of D. immitis nowadays transcends the need for genetic taxonomy of nematodes, such as the study of resistance to macrocyclic lactone. We expanded the use of long-read nanopore-based sequencing technology on nematodes by performing genomic de novo assembly of a D. immitis specimen retrieved from a canine cardiopulmonary dirofilariasis case using the ONT MinION platform, followed by the study of macrocyclic lactone resistance. The assembled genome of D. immitis consists of 110 contigs with an N50 of 3687191. The genome size is 87899012 and contains a total of 9741 proteins; 6 ribosomal RNAs, with three belonging to the small subunit (18S) and three to the large subunit (28S); and 73 tRNAs. Subsequent analysis of six loci previously characterized as being associated to macrocyclic lactone resistance selection pressure showed that four have a genotype associated with either some loss of efficacy or the resistance phenotype. Considering the zoonotic potential of D. immitis, the identification of a resistant parasite alerts for the overuse of macrocyclic lactone in the region, which poses a potential risk to both veterinary and human public health.
Genetic Evaluation and Population Structure of Jiangsu Native Pigs in China Revealed by SINE Insertion Polymorphisms
Authors: Wang Xiaoyan , D’Alessandro Enrico , Chi Chenglin , Moawad Ali Shoaib , Zong Wencheng , Chen Cai , Song Chengyi
Published: May 2022

Short interspersed nuclear elements (SINEs), one type of retrotransposon, are considered to be ideal molecular markers due to their wide distribution in the genome, high copy number, and high polymorphism. Preliminary studies have identified more than 35,000 SINE-retrotransposon insertion polymorphisms (RIPs) in the pig genome. In this study, 18 SINE-RIPs were used to evaluate the genetic variation and population structure of seven native pig populations and two crossbreeds in the Jiangsu Province of China. Two commercial pig breeds (Duroc and Large White) and one Italian native breed (Sicilian Black pig) were selected as the control. The results showed that all 18 SINE-RIPs were polymorphic among these pigs. The Jiangsu native pig populations (Erhualian, Fengjing, Middle Meishan, Mi, Shawutou, Small Meishan, and Huai) were shown to be more polymorphic than the crossbreeds (Sushan and Sujiang) and external breeds (Sicilian Black pig, Large White, and Duroc) based on the expected heterozygosity and polymorphic information content values. Some native pigs, including Small Meishan, Mi, Middle Meishan, and Erhualian, had a higher degree of inbreeding according to the FIS values. Based on the neighbor-joining tree, all of the Jiangsu native pig populations formed one branch, while the three external pig breeds formed the other branches, with the two crossbreeds containing more than 50% external pig ancestry. The Huai pigs were independent of the other Jiangsu native pigs but shared a common ancestor with Sujiang and Mi. The results provide a new perspective on the population structure of these native pig breeds and will assist with the conservation and utilization of Chinese native pigs.
Detection of Trypanosoma Infection in Dromedary Camels by Using Different Diagnostic Techniques in Northern Oman
Authors: Al-Kharusi Amal , Elshafie Elshafie Ibrahim , Baqir Senan , Faraz Asim , Al-Ansari Aliya , Burger Pamela , Mahgoub Osman , Al-Kharousi Kaadhia , Al-Duhli Halima , Al-Sinani Mohammed , Al-Hatali Raqiya , Roberts Derek
Published: May 2022

Camel trypanosomoses is considered a devastating disease with severe health consequences that can be caused by different hemoprotozoan parasites. Camel samples (388) from the five regions in Northern Oman were assessed using a thin blood film. In addition, 95 seropositive samples were analyzed using various primers of mechanically transmitted trypanosomes. Out of the 388 blood smears examined, 0.8% (CI 95%, 2/388) were found to be positive for Trypanosoma sp. using a microscope. The parasitologically positive cases were detected in samples from females. The overall molecular prevalences were as follows: TBR was 78/95, 77% (CI 73.1–89.2%); ITS was 30/95, 31.6% (CI 73.1–89.2%); and T. evansi type A (RoTat 1.2) was 8/95, 8.4% (CI 4.0–16.0%). There were two species of trypanosomes that were observed in the camels.
Are Virulence and Antibiotic Resistance Genes Linked? A Comprehensive Analysis of Bacterial Chromosomes and Plasmids
Authors: Darmancier Helena , Domingues Célia P. F. , Rebelo João S. , Amaro Ana , Dionísio Francisco , Pothier Joël , Serra Octávio , Nogueira Teresa
Published: May 2022

Although pathogenic bacteria are the targets of antibiotics, these drugs also affect hundreds of commensal or mutualistic species. Moreover, the use of antibiotics is not only restricted to the treatment of infections but is also largely applied in agriculture and in prophylaxis. During this work, we tested the hypothesis that there is a correlation between the number and the genomic location of antibiotic resistance (AR) genes and virulence factor (VF) genes. We performed a comprehensive study of 16,632 reference bacterial genomes in which we identified and counted all orthologues of AR and VF genes in each of the locations: chromosomes, plasmids, or in both locations of the same genome. We found that, on a global scale, no correlation emerges. However, some categories of AR and VF genes co-occur preferentially, and in the mobilome, which supports the hypothesis that some bacterial pathogens are under selective pressure to be resistant to specific antibiotics, a fact that can jeopardize antimicrobial therapy for some human-threatening diseases.
Pseudomonas aeruginosa Community-Onset Bloodstream Infections: Characterization, Diagnostic Predictors, and Predictive Score Development—Results from the PRO-BAC Cohort
Authors: Martínez Pérez-Crespo Pedro María , Rojas Álvaro , Lanz-García Joaquín Felipe , Retamar-Gentil Pilar , Reguera-Iglesias José María , Lima-Rodríguez Olalla , del Arco Jiménez Alfonso , Fernández Suárez Jonathan , Jover-Saenz Alfredo , Goikoetxea Aguirre Josune , León Jiménez Eva , Cantón-Bulnes María Luisa , Ortega Lafont Pilar , Armiñanzas Castillo Carlos , Sevilla Blanco Juan , Cuquet Pedragosa Jordi , Boix-Palop Lucía , Becerril Carral Berta , Bahamonde-Carrasco Alberto , Marrodan Ciordia Teresa , Natera Kindelán Clara , Reche Molina Isabel María , Herrero Rodríguez Carmen , Pérez Camacho Inés , Vinuesa García David , Galán-Sánchez Fátima , Smithson Amat Alejandro , Merino de Lucas Esperanza , Sánchez-Porto Antonio , Guzmán García Marcos , López-Hernández Inmaculada , Rodríguez-Baño Jesús , López-Cortés Luis Eduardo ,   on behalf of the PROBAC REIPI/GEIH-SEIMC/SAEI Group
Published: May 2022

Community-onset bloodstream infections (CO-BSI) caused by gram-negative bacilli are common and associated with significant mortality; those caused by Pseudomonas aeruginosa are associated with worse prognosis and higher rates of inadequateempirical antibiotic treatment. The aims of this study were to describe the characteristics of patients with CO-BSI caused by P. aeruginosa, to identify predictors, and to develop a predictive score for P. aeruginosa CO-BSI. Materials/methods: PROBAC is a prospective cohort including patients >14 years with BSI from 26 Spanish hospitals between October 2016 and May 2017. Patients with monomicrobial P. aeruginosa CO-BSI and monomicrobial Enterobacterales CO-BSI were included. Variables of interest were collected. Independent predictors of Pseudomonas aeruginosa CO-BSI were identified by logistic regression and a prediction score was developed. Results: A total of 78patients with P. aeruginosa CO-BSI and 2572 with Enterobacterales CO-BSI were included. Patients with P. aeruginosa had a median age of 70 years (IQR 60–79), 68.8% were male, median Charlson score was 5 (IQR 3–7), and 30-daymortality was 18.5%. Multivariate analysis identified the following predictors of CO-BSI-PA [adjusted OR (95% CI)]: male gender [1.89 (1.14–3.12)], haematological malignancy [2.45 (1.20–4.99)], obstructive uropathy [2.86 (1.13–3.02)], source of infection other than urinary tract, biliary tract or intra-abdominal [6.69 (4.10–10.92)] and healthcare-associated BSI [1.85 (1.13–3.02)]. Anindex predictive of CO-BSI-PA was developed; scores ≥ 3.5 showed a negative predictive value of 89% and an area under the receiver operator curve (ROC) of 0.66. Conclusions: We did not find a good predictive score of P. aeruginosa CO-BSI due to its relatively low incidence in the overall population. Our model includes variables that are easy to collect in real clinical practice and could be useful to detect patients with very low risk of P. aeruginosa CO-BSI.
Nanostructured Antibiotics and Their Emerging Medicinal Applications: An Overview of Nanoantibiotics
Authors: Modi Shreya , Inwati Gajendra Kumar , Gacem Amel , Saquib Abullais Shahabe , Prajapati Rajendra , Yadav Virendra Kumar , Syed Rabbani , Alqahtani Mohammed S. , Yadav Krishna Kumar , Islam Saiful , Ahn Yongtae , Jeon Byong-Hun
Published: May 2022

Bacterial strains resistant to antimicrobial treatments, such as antibiotics, have emerged as serious clinical problems, necessitating the development of novel bactericidal materials. Nanostructures with particle sizes ranging from 1 to 100 nanometers have appeared recently as novel antibacterial agents, which are also known as “nanoantibiotics”. Nanomaterials have been shown to exert greater antibacterial effects on Gram-positive and Gram-negative bacteria across several studies. Antibacterial nanofilms for medical implants and restorative matters to prevent bacterial harm and antibacterial vaccinations to control bacterial infections are examples of nanoparticle applications in the biomedical sectors. The development of unique nanostructures, such as nanocrystals and nanostructured materials, is an exciting step in alternative efforts to manage microorganisms because these materials provide disrupted antibacterial effects, including better biocompatibility, as opposed to minor molecular antimicrobial systems, which have short-term functions and are poisonous. Although the mechanism of action of nanoparticles (NPs) is unknown, scientific suggestions include the oxidative-reductive phenomenon, reactive ionic metals, and reactive oxygen species (ROS). Many synchronized gene transformations in the same bacterial cell are essential for antibacterial resistance to emerge; thus, bacterial cells find it difficult to build resistance to nanoparticles. Therefore, nanomaterials are considered as advanced solution tools for the fields of medical science and allied health science. The current review emphasizes the importance of nanoparticles and various nanosized materials as antimicrobial agents based on their size, nature, etc.
Synergistic Effects of Bacteriophage vB_Eco4-M7 and Selected Antibiotics on the Biofilm Formed by Shiga Toxin-Producing Escherichia coli
Authors: Necel Agnieszka , Bloch Sylwia , Topka-Bielecka Gracja , Janiszewska Agata , Łukasiak Aleksandra , Nejman-Faleńczyk Bożena , Węgrzyn Grzegorz
Published: May 2022

Apart from antibiotic resistance of pathogenic bacteria, the formation of biofilms is a feature that makes bacterial infections especially difficulty to treat. Shiga toxin-producing Escherichia coli (STEC) strains are dangerous pathogens, causing severe infections in humans, and capable of biofilm production. We have reported previously the identification and characterization of the vB_Eco4-M7 bacteriophage, infecting various STEC strains. It was suggested that this phage might be potentially used in phage therapy against these bacteria. Here, we tested the effects of vB_Eco4-M7 alone or in a phage cocktail with another STEC-infecting phage, and/or in a combination with different antibiotics (ciprofloxacin and rifampicin) on biofilm formed by a model STEC strain, named E. coli O157:H7 (ST2-8624). The vB_Eco4-M7 phage appeared effective in anti-biofilm action in all these experimental conditions (2–3-fold reduction of the biofilm density, and 2–3 orders of magnitude reduction of the number of bacterial cells). However, the highest efficiency in reducing a biofilm’s density and number of bacterial cells was observed when phage infection preceded antibiotic treatment (6-fold reduction of the biofilm density, and 5–6 orders of magnitude reduction of the number of bacterial cells). Previous reports indicated that the use of antibiotics to treat STEC-caused infections might be dangerous due to the induction of Shiga toxin-converting prophages from bacterial genomes under stress conditions caused by antibacterial agents. We found that ciprofloxacin was almost as efficient in inducing prophages from the E. coli O15:H7 (ST2-8624) genome as a classical inducer, mitomycin C, while no detectable prophage induction could be observed in rifampicin-treated STEC cells. Therefore, we conclude the latter antibiotic or similarly acting compounds might be candidate(s) as effective and safe drug(s) when used in combination with phage therapy to combat STEC-mediated infections.
Fast Loop Closure Selection Method with Spatiotemporal Consistency for Multi-Robot Map Fusion
Authors: Chen Wei , Sun Jian , Zheng Qiang
Published: May 2022

This paper presents a robust method based on graph topology to find the topologically correct and consistent subset of inter-robot relative pose measurements for multi-robot map fusion. However, the absence of good prior on relative pose gives a severe challenge to distinguish the inliers and outliers, and once the wrong inter-robot loop closures are used to optimize the pose graph, which can seriously corrupt the fused global map. Existing works mainly rely on the consistency of spatial dimension to select inter-robot measurements, while it does not always hold. In this paper, we propose a fast inter-robot loop closure selection method that integrates the consistency and topology relationship of inter-robot measurements, which both conform to the continuity characteristics of similar scenes and spatiotemporal consistency. Firstly, a clustering method integrating topology correctness of inter-robot loop closures is proposed to split the entire measurement set into multiple clusters. Then, our method decomposes the traditional high-dimensional consistency matrix into the sub-matrix blocks corresponding to the overlapping trajectory regions. Finally, we define the weight function to find the topologically correct and consistent subset with the maximum cardinality, then convert the weight function to the maximum clique problem from graph theory and solve it. We evaluate the performance of our method in a simulation and in a real-world experiment. Compared to state-of-the-art methods, the results show that our method can achieve competitive performance in accuracy while reducing computation time by 75%.
Determining the Shear Resistance in Landslides with Respect to Shear Displacement and Shearing Time in Drainage-Controlled Ring Shear Tests
Authors: Jeong Sueng-Won
Published: May 2022

Shear stress is an important parameter in estimating the slope stability and flow dynamics in mass movements. The ring shear test can often be employed to determine the residual shear stress because of its suitability for large deformations for assumed in situ stress and drainage conditions. Determination of the residual shear stress of weathered landslide materials composed of coarse-grained sediments was examined with respect to the shear displacement and drainage condition. Based on the experimental results, the shear stress of landslide materials has typical maximum and minimum values (i.e., peak and residual shear stress). The measured shear stress generally increases with an increase in shear speed regardless of drainage condition. In general, the residual shear stress can be measured when a relatively long shearing time is applied. The residual shear stress, which is known as the minimum shear resistance at the initiation of landslide occurrence along the pre-existing slip surface of the landslide body, is also measurable even though limited shear displacement (0.1–100 mm) and shear speed (0.1–100 mm/s) are applied. The minimum range of residual shear stress of weathered soils obtained from the ring shear tests is roughly half of the value obtained from the direct shear tests. The residual shear stress can be used to estimate the reactivation of slope movement.
Occupants’ Perspectives of the Use of Smartphones during Fire Evacuation from High-Rise Residential Buildings
Authors: Gerges Michael , Demian Peter , Khalafallah Ahmed , Salamak Marek
Published: May 2022

Over the past few years there has been a significant change in fire safety design and management. As the possibility of safe escape is the most crucial aspect of a building’s fire safety features, the understanding of human behaviour under fire conditions is important for a successful evacuation. Previous research studies have developed models, prototypes, and serious games that help engineers/architects to design or firefighters to improve design so that the building facilitates a smooth evacuation process. Although these studies have looked into human behaviour, perceptions of important stakeholders (such as occupants, structural engineers, fire engineers, facility managers) are still not understood. These perceptions are important for the appropriate application of technology for evacuation. The broader research effort, of which this paper is part, stems from the premise that bespoke evacuation instructions can be sent directly to evacuees’ smartphones. Information from a BIM model with the aid of sensors can be used to customise these evacuation instructions. The prospect of information being delivered to occupants during a fire emergency is still at its premature phase and more research is needed. Twenty-three interviews were conducted with occupants who currently live in high-rise residential buildings in Egypt and the United Kingdom to understand their views of using smartphones to assist during fire evacuations. The sampling strategy targeted occupants who currently live in high-rise residential buildings but have not necessarily experienced a fire evacuation. The research clearly shows the importance of smartphones during evacuation and the role they can play in assisting occupants to find the fastest and safest egress route. The interview findings will assist in future research to develop an evacuation framework system that could be implemented for high-rise residential buildings.
Performance Analysis of Acceleration and Inertial Force of Electromagnetic Suspension Inertial Stabilizer
Authors: Gao Sumei , Xu Longxiang , Jin Chaowu
Published: May 2022

In this paper, the structural characteristics of electromagnetic suspension (EMS) inertial stabilizers are analyzed firstly, and then a mechanical analysis of a single mass block and double mass block is carried out. The relationship model between the inertial anti-rolling mass block and inertial force transmitted to the ship is established. The inertial force is determined by the number of coil turns, coil current, mass block, mass of the ship, electromagnet current, rate of change of the electromagnet current, air gap between the electromagnet and inertial mass block, and rotational angular speed. Through theoretical analysis, it is found that the response speed of inertia force is directly related to the electromagnetic coil current, the voltage at both ends of the electromagnetic coil, the coil resistance and the air gap. It is concluded that the response speed of the inertia force can be controlled by controlling the coil current, adjusting the voltage at both ends of the coil and adjusting the air gap. The inductance of the electromagnetic coil will also increase the nonlinearity of the inertial anti-roll system. On the basis of theoretical analysis, a digital simulation of EMS inertial stabilizer is carried out by MATLAB and ANSYS MAXWELL2D. Finally, a single mass block system of EMS inertial stabilizer is designed and tested. During the test, a 1.5 V sinusoidal excitation voltage is added to the electromagnetic coil after the mass block is suspended stably, and the maximum acceleration values of the inertial anti-rolling mass block and hull are 10.29 m/s2 and 1.27 m/s2. Finally, the theoretical analysis results, digital simulation results and experimental results are analyzed, which verifies the correctness of the acceleration and inertia force performance analysis of the EMS inertial stabilizer.
Prediction of Shallow Failure on a Slope Using Volumetric Water Content Gradient Characteristics
Authors: Suk Jae-Wook , Jeong Hyang-Seon , Jung Min-Su , Kang Hyo-Sub , Kim Ho-Jong , Choi Sun-Gyu
Published: May 2022

Landslides that occur near residential regions are most commonly a result of shallow slope failure, which takes place as a consequence of heavy rainfall during the monsoon season, causing loss to human life and property. In this study, the characteristics of the volumetric water content (VWC) gradient were analyzed to predict shallow slope failure which was reproduced based on flume experiments performed at various slope conditions. The VWC gradient values were calculated for each measurement position and slope depth. Moreover, the VWC gradient characteristics during the occurrence and nonoccurrence of shallow slope failures were compared to those of an actual site that did not undergo slope failure. Our results show that the probability of failure increases with an increase in the VWC gradient value. Additionally, early warning criteria are proposed by dividing the range of the VWC gradient value into four stages in which the failure rate rapidly increased. Full-scale flume experiments were performed to simulate an actual site in terms of its scale, and the appropriate sensor installation positions were proposed to effectively predict the probability of failure.
Deep Reinforcement Factorization Machines: A Deep Reinforcement Learning Model with Random Exploration Strategy and High Deployment Efficiency
Authors: Yu Huaidong , Yin Jian
Published: May 2022

In recent years, the recommendation system and robot learning are undoubtedly the two most popular application fields, and the core algorithms supporting these two fields are deep learning based on perception and reinforcement learning based on exploration learning, respectively. How to combine these two fields to better improve the development of the whole machine learning field is the dream of numerous researchers. The Deep Reinforcement Network (DRN) model successfully embedded reinforcement learning into the recommendation system, which provided a good idea for subsequent researchers. However, the disadvantage is also obvious, that is, the DRN model is built for news recommendations, meaning that the DRN model is not transferable, which is also the defect of many current recommendation system models. Meanwhile, the agent learning method adopted by the DRN model is primitive and inefficient. Among many models and algorithms that have emerged in recent years, we use the newly proposed deployment efficiency to measure their comprehensive quality and found that few models focus on both efficiency and performance improvement. To fill the gap of model deployment efficiency neglected by many researchers and to create a model of reinforcement learning agents with stronger performance, we have been exploring and trying to complete research on the Gate Attentional Factorization Machines (GAFM) model. Finally, we successfully integrated the GAFM model and reinforcement learning. The Deep Reinforcement Factorization Machines (DRFM) model proposed in this paper is based on the combination of deep learning with high perception ability and reinforcement learning with high exploration ability, centered on improving the deployment efficiency and learning performance of the model. The GAFM model is modified and upgraded using multidisciplinary techniques, and a new model-based random exploration strategy is proposed to update and optimize the recommendation list efficiently. Through parallel contrast experiments on various datasets, it is proved that the DRFM model surpasses the traditional recommendation system model in all aspects. The DRFM model is far superior to other models in terms of performance and robustness, and also significantly improved in terms of deployment efficiency. At the same time, we conduct a comparative analysis with the latest deep reinforcement learning algorithm and prove the unique advantages of the DRFM model.
Affinity-Point Graph Convolutional Network for 3D Point Cloud Analysis
Authors: Wang Yang , Xiao Shunping
Published: May 2022

Efficient learning of 3D shape representation from point cloud is one of the biggest requirements in 3D computer vision. In recent years, convolutional neural networks have achieved great success in 2D image representation learning. However, unlike images that have a Euclidean structure, 3D point clouds are irregular since the neighbors of each node are inconsistent. Many studies have tried to develop various convolutional graph neural networks to overcome this problem and to achieve great results. Nevertheless, these studies simply took the centroid point and its corresponding neighbors as the graph structure, thus ignoring the structural information. In this paper, an Affinity-Point Graph Convolutional Network (AP-GCN) is proposed to learn the graph structure for each reference point. In this method, the affinity between points is first defined using the feature of each point feature. Then, a graph with affinity information is built. After that, the edge-conditioned convolution is performed between the graph vertices and edges to obtain stronger neighborhood information. Finally, the learned information is used for recognition and segmentation tasks. Comprehensive experiments demonstrate that AP-GCN learned much more reasonable features and achieved significant improvements in 3D computer vision tasks such as object classification and segmentation.
A Method to Produce vsiRNAs in Plants with Cross-Kingdom Gene Silencing Capacity
Authors: Villanueva-Alonzo Hernán de Jesús , Haro-Álvarez Ana Paulina , Alvarado-Segura Arturo A. , Valle-Gough Raúl Enrique , Collí-Mull Juan Gualberto , Cal-Torres Alberto , Arana-Argáez Víctor Ermilo , Torres-Romero Julio César , Moreno-Valenzuela Oscar Alberto , Nic-Can Geovanny , Ayil-Gutiérrez Benjamín Abraham , Acosta-Viana Karla Y.
Published: May 2022

Plants have evolved defense mechanisms to suppress viral transcription and replication by transcriptional and post-transcriptional gene silencing mediated by virus-derived small interfering RNAs (vsiRNAs). Based on this response, virus-induced gene silencing (VIGS)-based technology has been developed to silence target genes on either host plants or insect pests. This mechanism could also be used for the silencing of genes of interest in the medical field. We used the VIGS vector pEuMV-YP:Krt18, which was obtained by inserting the Mus musculus (M. musculus) Krt18 sequence into pEuMV-YP:ΔAV1. The objective was to evaluate the capacity of pEuMV-YP:Krt18 to induce Nicotiana benthamiana (N. benthamiana) production of vsiRNAs of a specific sequence that belongs to neither the plant genome nor the wild virus genome, which were used to induce cross-kingdom gene silencing between plants and mammals. The percentage of vsiRNA for each viral gene was calculated from an sRNA library of N. benthamiana plants infected by pEuMV-YP: Krt18. When the vsiRNAs were characterized, it was found that they corresponded to all the genes of the pEuMV-YP:Krt18 vector. These vsiRNAs induced the silencing of the Krt18 gene in M. musculus macrophages, supporting the ability to use VIGS vectors in plants as biofactories for the production of sRNAs that induce gene silencing in mammals.
Effect of Chitosan Solution on Low-Cohesive Soil’s Shear Modulus G Determined through Resonant Column and Torsional Shearing Tests
Authors: Bocheńska Marta , Bujko Marcin , Dyka Ireneusz , Srokosz Piotr , Ossowski Rafał
Published: May 2022

In this study the effect of using a biopolymer soil stabilizer on soil stiffness characteristics was investigated. Chitosan is a bio-waste material that is obtained by chemical treatment of chitin (a chemical component of fungi or crustaceans’ shells). Using chitosan solution as a soil stabilizer is based on the assumption that the biopolymer forms temporary bonds with soil particles. What is important is that these bonds are biodegradable, so the product does not leave any harmful waste and has high eco-compatibility. The biopolymer itself is a by-product of many industrial chemical processes, so its application is compliant with the goals of sustainable geotechnical engineering. The effect of chitosan on soil shear strength, permeability or surface erosion has already been investigated in several different studies. In this study specimens of low-cohesive soil stabilized with two different chitosan solutions were subject to cyclic loading (torsional shearing test) and dynamic loading (resonant column) to obtain soil shear modulus G as a function of strain values. It has been shown that chitosan solution added to medium-grained materials improves their shear modulus G substantially (up to 3 times) even for relatively low chitosan concentration solutions (1.5 g of chitosan per 1 kg of dry silica sand). The results obtained in this study and the known chitosan properties suggest that chitosan solutions can be a very effective and eco-friendly short-term stabilizer for temporary geotechnical structures, e.g., working platforms.
Optimization of the Preformulation and Formulation Parameters in the Development of New Extended-Release Tablets Containing Felodipine
Authors: Pop Anca Lucia , Musuc Adina Magdalena , Nicoară Anca Cecilia , Ozon Emma Adriana , Crisan Simona , Penes Ovidiu Nicolae , Nasui Bogdana Adriana , Lupuliasa Dumitru , Secăreanu Ana Andreea
Published: May 2022

Herein, new extended-release tablets containing felodipine were developed. For the orally administered formulations, optimization of the preformulation and formulation parameters was performed to assess the performance of the dosage form. Initially, the morphological and physical characterization of two forms of felodipine (microcrystalline and macrocrystalline) using Fourier transform infrared spectroscopy, differential scanning calorimetry and optical microscopy was performed. The pharmaco-technical properties of the two felodipine forms were also determined. Subsequently, formulation studies for felodipine extended-release tablets were performed. Mathematical modelling of release kinetics of felodipine from developed formulations using a power law model was also performed. Based on the influence of formulation factors on the in vitro availability of felodipine in experimental tablets, a new extended-release tablet formulation was established.
Development of a Model Material for Dynamic Geotechnical Model Tests
Authors: Tian Jianlin , Wang Liangqing , An Cailong , Wu Qiong , Sun Zihao , Ke Rui
Published: May 2022

To develop a model material suitable for analysing the stability of sandstone slopes during strong earthquakes, an orthogonal test was designed by selecting seven physico-mechemical parameters, a combination of dynamic and static parameters, as research indexes. Then, the influence of the proportion of each component in the model material on each test index was determined by sensitivity analysis, and the quantitative relationship between physico-mechanical parameters and component proportions was established by multiple linear regression analysis to develop a model material similar to sandstone. Finally, a sandstone slope along the Duxiang Expressway was taken as an example, and the proportions of the components suitable for a model of the rock mass in this area were determined. The test results showed that (1) the physico-mechanical parameters selected for the dynamic and static tests were used to effectively develop model materials for dynamic geotechnical model tests; (2) samples of model materials composed of barite powder, quartz sand, ferric powder, gypsum and cement met the requirements for dynamic testing of geotechnical models of sandstone slopes; and (3) through sensitivity analysis of various factors and multiple linear regression analysis, the required model materials were efficiently configured, and the failure mode, failure process and physico-mechanical parameters of the model materials accurately simulated the original rock materials.
Development of an Integrated Lightweight Multi-Rotor UAV Payload for Atmospheric Carbon Dioxide Mole Fraction Measurements
Authors: Zhao Tonghui , Yang Dongxu , Liu Yi , Cai Zhaonan , Yao Lu , Che Ke , Ren Xiaoyu , Bi Yongheng , Yi You , Wang Jing , Zhu Sihong
Published: May 2022

Records and projections of increasing global average temperature call for improvements of global stocktake inputs, which are vital to achieving targets of intergovernmental agreements on climate change. Unmanned Aerial Vehicle (UAV)-based atmospheric observation of greenhouse gas (GHG) concentrations is an upcoming addition to the top-down measurement methods due to its advantageous spatial-temporal resolutions, greater coverage area and lower costs. Hence, we developed and tested a lightweight UAV payload enclosure integrating a non-dispersive diffusion infrared (NDIR) spectrometer and two electrochemical sensors for measurements of carbon dioxide (CO2), carbon monoxide (CO) and nitrogen dioxide (NO2). To achieve higher response times and maintain measurement qualities, we designed a custom air inlet on the rotor-facing side of the enclosure to reduce measurement fluctuations caused by rotor downwash airflow. To validate the payload design, we conducted a controlled test for comparing chambered and chamber-less NDIR spectrometer measurements. From the test we observed a reduction of 0.48 hPa in terms of standard deviation of pressure measurements and minimised downwash-flow-induced anomalous biases (+0.49 ppm and +0.08 hpa for chambered compared to −1.33 ppm and −1.05 hpa for chamber-less). We also conducted an outdoor in-situ measurement test with multiple flights reaching 500 m above ground level (ABGL). The test yielded high resolution results representing vertical distributions of mole fraction concentrations of three types of gases via two types of flight trajectory planning methods. Therefore, we provide an alternative UAV payload integration method for NDIR spectrometer CO2 measurements that complement existing airborne GHG observation methodologies. Additionally, we also introduced an aerodynamic approach in reducing measurement noises and biases for a low response time sensor configuration.
Resource-Based Industries and CO2 Emissions Embedded in Value Chains: A Regional Analysis for Selected Countries in Latin America
Authors: Sanguinet Eduardo Rodrigues , Azzoni Carlos Roberto , Alvim Augusto Mussi
Published: May 2022

This paper analyzes the relative content of CO2 emissions embedded in regional supply chains in four different countries in Latin America: Brazil, Chile, Colombia, and Mexico. We estimate both the trade in value-added (TiVA) and the CO2 content embedded in interregional and foreign exports, mapping the relative intensity of CO2 emission levels on value chains. For that, we applied an inter-regional input-output model to determine the interplay between the CO2 emission embedded in goods of resource-based industries and their linkages with other economic industries, revealing a map of CO2 emissions on trade in value-added trade from a subnational dimension. The main result reveals an interregional dependence, indicating a higher level of embedded CO2 on value-added in each regional economy for resource-based industries, usually intense in CO2 emissions. This finding has considerable implications for the sustainable development goals of these subnational areas, as the spatial concentration of production leads to an unbalanced regional capacity for promoting reductions in CO2 emissions along with value chains.
Modelling Methane Adsorption Isotherms on Shale at Different Temperatures
Authors: Zhang Dongqing
Published: May 2022

Prediction of adsorption isotherms under different temperatures is significant to reserve estimation of shale gas reservoirs. Based on the Polanyi adsorption potential theory and Langmuir adsorption theory, a method was presented to predict adsorption isotherms at different temperatures. In this method, the relationship between Langmuir pressure and temperature was quantified. By utilizing this method, we predicted adsorption isotherms of Longmaxi shale from 45 °C to 120 °C according to experimental data at 30 °C. Meanwhile, by considering the pressure and temperature gradients, we also predicted the adsorption capacity of Longmaxi shale with geologic depth. Results show that the adsorption data predicted by our method are in accord with experimental data and the error coefficient is less than 5%. In addition, the isosteric heat of adsorption for Longmaxi shale can be calculated by predicted adsorption data based on the Clausius–Clapeyron equation of capillary systems. Therefore, our study illustrates theoretical foundations for the efficient evaluation of adsorbed gas content in shale gas reservoirs at geologic conditions.