bluuebunny/crossref_metadata_2025 huggingface dataset:
Rethinking Healthcare Teams’ Practices Using Network Science: Implications, Challenges, and Benefits
Authors: Aloini Davide , Ferraro Giovanna , Iovanella Antonio , Stefanini Alessandro
Published: June 2022

Healthcare teams act in a very complex environment and present extremely peculiar features since they are multidisciplinary, work under quickly changing conditions, and often stay together for a short period with a dynamically fluctuating team membership. Thus, in the broad discussions about the future of healthcare, the strategy for improving providers’ collaboration and team dynamics is becoming a central topic. Within this context, this paper aims to discuss different viewpoints about the application of network science to teamworking. Our results highlight the potential benefits deriving from network science-enabled analysis, and also show some preliminary empirical evidence through a real case study. In so doing, we intend to stimulate discussions regarding the implications of network science in the investigation and improvement of healthcare teams. The intention is to pave the way for future research in this context by suggesting the potential advantages of healthcare teamwork analysis, as well as recognising its challenges and threats.
Experimental Capture Width Ratio on Unit Module System of Hybrid Wave Energy Converter for Nearshore
Authors: Park Min-Su , Lee Seung-Heon , Ko Sang-Cheol
Published: June 2022

This study proposes a new hybrid wave energy converter composed of a horizontal cylinder and a swing plate to improve the capture width ratio. The horizontal cylinder generates electrical energy by using the potential energy of the incident wave, whereas the swing plate produces electrical energy by using the kinetic energy of the water particles. The converter can improve the capture width ratio of the wave energy by efficiently combining the energies generated by these two different sources. The power-generating performance of the proposed hybrid wave energy converter is evaluated experimentally through a hydraulic model test at a scale ratio of 0.3 in a two-dimensional wave tank using direct conversion by a dynamo PTO (Power Take-Off) system. The dynamic power-generation characteristics of the hybrid wave energy converter are analyzed with respect to the eventual regularity of the incident wave (regular and irregular wave conditions), and the data necessary for the design of the generator and control system are acquired.
Research on the Prediction Model of Blasting Vibration Velocity in the Dahuangshan Mine
Authors: Guo Jiang , Zhang Chen , Xie Shoudong , Liu Yi
Published: June 2022

In order to improve the prediction accuracy of blast vibration velocity, the model for predicting the peak particle velocity of blast vibration using the XGBoost (Extreme Gradient Boosting) method is improved, and the EWT–XGBoost model is established to predict the peak particle velocity of blast vibration by combining it with the EWT (Empirical Wavelet Transform) method. Calculate the relative error and root mean square error between the predicted value and measured value of each test sample, and compare the prediction performance of the EWT–XGBoost model with the original model. There is a large elevation difference between each vibration measurement location of high and steep slopes, but high and steep slopes are extremely dangerous, which is not conducive to the layout of blasting vibration monitoring equipment. The vibration velocity prediction model adopts the numerical simulation method, selects the center position of the small platform as the measurement point of the peak particle velocity, and studies the variation law of the blasting vibration velocity of the high and steep slopes under the action of top blasting. The research results show that the EWT–XGBoost model has a higher accuracy than the original model in the prediction of blasting vibration velocity; the simultaneous detonation method on adjacent high and steep slopes cannot meet the relevant requirements of safety regulations, and the delayed detonation method can effectively reduce the blasting vibration of high and steep slopes. The shock absorption effect of the elevation difference within 45 m is obvious.
Scanning Inductive Thermographic Surface Defect Inspection of Long Flat or Curved Work-Pieces Using Rectification Targets
Authors: Tuschl Christoph , Oswald-Tranta Beate , Eck Sven
Published: June 2022

Inductive thermography is an NDT method, which can be excellently used to inspect long metallic specimens (such as railway tracks) to detect surface defects. Aiming at the inspection of railway tracks in service with a movable setup, the method had to be advanced from a stationary application to a scanning setup. This work presents methods for using calibration targets for rectification, in order to improve the quality of the resulting images. Two scanning techniques are presented for detecting different types of rolling contact fatigue (RCF) defects on rail pieces. In the case of the first method, separate stationary inductive pulsed measurements are carried out for the segments of a long sample and the results are stitched together to one panoramic image of the whole specimen (“stop-and-go”). Since the surface of the rail piece is curved, rectification of the surface with a flexible grid is necessary to generate seamless panoramic images. In the case of the second method, a specimen is moved with constant speed underneath the induction coil. For the detection of shallow surface cracks, the infrared camera has to have a view of the surface during the heating; therefore, the camera is placed behind the coil but tilted towards a position below the induction coil. In order to be able to evaluate phase images from the temporal temperature change, a checkerboard grid as a rectification target is used. It is also analyzed how the chosen IR camera frame rate and the motion speed affect the scanning result.
Deep Learning-Based Bug Report Summarization Using Sentence Significance Factors
Authors: Koh Youngji , Kang Sungwon , Lee Seonah
Published: June 2022

During the maintenance phase of software development, bug reports provide important information for software developers. Developers share information, discuss bugs, and fix associated bugs through bug reports; however, bug reports often include complex and long discussions, and developers have difficulty obtaining the desired information. To address this issue, researchers proposed methods for summarizing bug reports; however, to select relevant sentences, existing methods rely solely on word frequencies or other factors that are dependent on the characteristics of a bug report, failing to produce high-quality summaries or resulting in limited applicability. In this paper, we propose a deep-learning-based bug report summarization method using sentence significance factors. When conducting experiments over a public dataset using believability, sentence-to-sentence cohesion, and topic association as sentence significance factors, the results show that our method outperforms the state-of-the-art method BugSum with respect to precision, recall, and F-score and that the application scope of the proposed method is wider than that of BugSum.
CPN4M: Testing Multi-Agent Systems under Organizational Model Moise+ Using Colored Petri Nets
Authors: Gonçalves Eder Mateus Nunes , Machado Ricardo Arend , Rodrigues Bruno Coelho , Adamatti Diana
Published: June 2022

Multi-agent systems (MASs) are distributed and complex software that demand specific software engineering features. Testing is a critical phase when validating software, and it is also difficult to conceive and execute. Designing systems under a multi-agent paradigm is even more difficult because of properties such as autonomy, reactivity, pro-activity, and social skills. Any multi-agent system has at least three main dimensions: the individual and social levels and communication interfaces. Considering an approach for testing a dimension specifically, we deal with the social level as an organizational model in this paper. It imposes some restrictions on agents’ behavior through a set of behavioral constraints. In this sense, an error in the organization can occur when the allocated resources are not enough for executing plans and reaching goals. This work aims to present a whole framework for analyzing and testing MAS social level under organizational model Moise+. This framework uses a Moise+ specifications set as information artifact mapped in a colored Petri net (CPN) model, named CPN4M, as a test case generation mechanism. CPN4M uses two different test adequacy criteria: all-paths and state-transition path. In this paper, we have formalized the transition from Moise+ to CPN, the procedures for test case generation, and executed some tests in a case study. The results indicate that this methodology can increase the correction degree for a social level in a multi-agent system specified by a Moise+ model, indicating the system context that can lead the MAS for failures.
Patent Analysis of the Development of Technologies Applied to the Combustion Process
Authors: Santos Alex Álisson Bandeira , Neves Paulo Roberto Freitas , Oliveira Fabricia Oliveira , Nunes Danielle Devequi Gomes , Machado Bruna Aparecida Souza
Published: June 2022

The use of combustion in industrial activity is of paramount importance for economic and social development. However, combustion reactions are the main sources of atmospheric pollutant emissions. Given this reality, it is necessary to study new combustion techniques, such as the application of oxygen in the process, in order to increase the efficiency and productivity of the burning process and energy production. In addition, studies have reported the use of acoustic excitation, a low-investment technique that can promote higher rates of heat and mass transfer. Thus, the goal of this study was to bring data on the current scenario related to the application of these two technologies to the combustion process where, through the reported results, they can be used as a guide for companies’ decisions about new technologies and global trends to be identified. For this, a technological prospection was carried out which focused on patents to investigate the use of oxygen-enhanced combustion and acoustic excitation coupled to the combustion process; a total of 88 documents were found. Few documents applied acoustic excitation for process improvement, indicating that its use is recent; however, according to the literature, it is a promising field to be explored. Siemens AG was the main depositor, and ten primary inventors were identified. Germany and the United States were the countries with the highest number of filings. In the prospected documents, it was possible to identify that there is a need for the further investigation of the joint use of both techniques. These investigations may lead to the development of processes and devices that can provide economic and environmental gains for the energy industry.
Reliability Assessment of PAUT Technique in Lieu of RT for Tube Welds in Thermal Power Plant Facilities
Authors: Choi Yu Min , Kang Dongchan , Kim Young Lae , Cho Sungjong , Park Taesung , Park Ik Keun
Published: June 2022

In this study, a reliability evaluation of the phased array ultrasonic testing (PAUT) method was performed to examine the applicability of the method for tube weld specimens with flaws having the same specifications as the tubes in the boilers of thermal power plant facilities. To this end, test specimens were fabricated by inserting flaws into tube welds with identical materials and specifications to those used in the thermal power plant. PAUT data acquisition was obtained using a round robin test (RRT) on the fabricated specimen, and the data were compared with the results of radiographic testing (RT) for a comparative evaluation of the flaw detection performance. In addition, for quantitative reliability analysis, the flaw detection performance (probability of detection; POD) and the error in the sizing accuracy (root-mean-square error; RMSE) were calculated with different materials of the specimens (carbon steel, stainless steel, dissimilar metal) and flaw types (volumetric, planar). In the analysis results, for high-risk planar defects, the PAUT technique exhibited superior flaw detection performance to the RT technique. A POD analysis of the PAUT technique indicated that flaws of 6.9 mm length were detected at 80% probability for total tube specimens. Furthermore, a reliability analysis was performed for test specimens of different materials and flaw types, and the results were derived. Through the findings of this study, the applicable range of the PAUT technique was examined, and a technical basis for PAUT in lieu of RT was established.
Multi-Exposure Image Fusion Based on Weighted Average Adaptive Factor and Local Detail Enhancement
Authors: Wang Dou , Xu Chao , Feng Bo , Hu Yunxue , Tan Wei , An Ziheng , Han Jubao , Qian Kai , Fang Qianqian
Published: June 2022

In order to adapt to the local brightness and contrast of input image sequences, we propose a new weighted average adaptive factor well-exposure weight evaluation scheme. The exposure weights of brighter and darker pixels are determined according to the local average brightness and expected brightness. We find that in the traditional multi-exposure image fusion scheme, the brighter and darker regions of the scene lose many details. To solve this problem, we first propose a standard to determine the brighter and darker regions and then use a fast local Laplacian filter to enhance the image in the region. This paper selects 16 multi-exposure images of different scenes for subjective and objective analysis and compares them with eight existing multi-exposure fusion schemes. The experimental results show that the proposed method can enhance the details appropriately while preserving the details in static scenes and adapting to the input image brightness.
Energy Efficiency Improvement of Diesel–Electric Trains Using Solar Energy: A Feasibility Study
Authors: Fayad Ahmad , Ibrahim Hussein , Ilinca Adrian , Sattarpanah Karganroudi Sasan , Issa Mohamad
Published: June 2022

Nowadays, productivity challenges in modern manufacturing systems have been the driving force in generating energy-efficient technologies in every industry, including diesel–electric locomotives. The diesel–electric locomotive is one of the most widely used methods in rail transportation, especially in North America. More precisely, the evolution of the electric transmission has allowed the locomotive’s effective tractive effort to increase its diesel engine horsepower. In this paper, we study a new way to improve the energy efficiency of diesel–electric trains using photovoltaic solar panels. This solution is suitable for reducing greenhouse gas emissions of the diesel–electric locomotive system, particularly in cold climates. We explore the amount of energy produced by the PV solar panels and compare it with that produced by the auxiliary diesel-generator during a train’s journey. This comparison clarifies the actual percentage of energy that solar panels can cover. Thus, this paper presents a validation of feasibility and profitability as a function of the train’s specific operating conditions and the meteorological data associated with their routes. Based on the results, the minimum annual fuel reduction of auxiliary generators allowed using PV solar panels is above 50% in all cases and wagon classes, proving this solution’s feasibility. Regarding the comparison, case 3 (Sept-Îles to Schefferville) and case 4 (Luxor to Aswan) are the best, with over 100% of the energy provided by PV solar panels in all the wagons’ classes. The payback period ranges from 2.5 years to 9.1 years, while the CO2 emission reduction’s revenues range from $460 to $998 per year/wagon.
Study of the Healing Effect of Concrete with Supplementary Cementitious Materials after Early-Age Damage by Acoustic Emission Technique
Authors: Chen Zhonggou , He Rui , Jin Xianyu
Published: June 2022

The study on the influence of early age damage of concrete on its long-term strength development is of great importance. In this work, 102 concrete cubes with and without supplementary cementitious materials (SCMs) were prepared. The pre-loading with loading degrees of 20%, 50%, and 80% of the corresponding compressive strength at 3-, 7-, 14-, and 28 d age was applied to the concrete samples. Then, concrete samples were further cured to 270 d, and the compressive strength was tested by the uniaxial compression test. The acoustic emission signals during the compressive strength test were collected. It is found that the pozzolanic reaction healed the damage caused by the early age damage, and the compressive strength of concrete with the incorporation of SCMs at 270 d age after pre-loading was higher than that of ordinary concrete without SCMs. The peak frequency of the uniaxial compression acoustic emission of concrete can be divided into four frequency intervals to correspond to different damage mechanisms of concrete, namely: interval I (12 ± 5 kHz), interval II (38 ± 5 kHz), interval III (171 ± 5 kHz), interval IV (259 ± 5 kHz).
Simple Compressive Strength Results of Sodium-Hydroxide- and Sodium-Silicate-Activated Copper Flotation Tailing Geopolymers
Authors: Castillo Hengels , Droguett Thomas , Vesely Mario , Garrido Pamela , Palma Sergio
Published: June 2022

Geopolymers are created by mixing a source of aluminosilicates, which can be natural or by-products of other industries, with an alkaline solution, which dissolves the aluminates and silicates present in this source, where after a polymerization process, an N-A-S-H gel is formed, which is responsible for providing the properties that characterize geopolymers. Among the variety of existing geopolymers, those based on by-products from other industries stand out since they were demonstrated to be a less-polluting alternative for concrete production than ordinary Portland cement (OPC). Due to the above, it is essential to study copper flotation tailings as raw material to generate geopolymers. The excessive amounts of existing tailing deposits also produce different risks for the nearby communities. Therefore, using this industrial waste as a construction material would provide several environmental and economic benefits. This article reports on the experimental work carried out in the laboratory of the Sustainable Mining Research Center CIMS of the Engineering Consulting Company JRI, where the effect of the alkaline activator type on the compressive strength of geopolymers based on copper flotation tailings was analyzed. For this purpose, two geopolymeric mixtures were made with different kinds of alkaline activators; one activated using 100% NaOH and the other activated with 100% sodium silicate (SS). From the results, it was found that the geopolymers activated with 100% SS obtained the highest compressive strength, reaching 36.46 MPa with 7 days of curing at 90 °C, followed by the geopolymers activated with 100% NaOH, where a compressive strength of 22.98 MPa was obtained under the same curing conditions. On the other hand, it was found that both geopolymers created were not leachable according to the TCLP test performed, and thus, these geopolymers were classified as non-toxic materials. In addition, it was found that both geopolymers presented a high infiltration value, making them practically impermeable.
Detecting Deceptive Utterances Using Deep Pre-Trained Neural Networks
Authors: Wawer Aleksander , Sarzyńska-Wawer Justyna
Published: June 2022

Lying is an integral part of everyday communication in both written and oral forms. Detecting lies is therefore essential and has many possible applications. Our study aims to investigate the performance of automated lie detection methods, namely the most recent breed of pre-trained transformer neural networks capable of processing the Polish language. We used a dataset of nearly 1500 true and false statements, half of which were transcripts and the other half written statements, originating from possibly the largest study of deception in the Polish language. Technically, the problem was posed as text classification. We found that models perform better on typed than spoken utterances. The best-performing model achieved an accuracy of 0.69, which is much higher than the human performance average of 0.56. For transcribed utterances, human performance was at 0.58 and the models reached 0.62. We also explored model interpretability based on integrated gradient to shed light on classifier decisions. Our observations highlight the role of first words and phrases in model decisions, but more work is needed to systematically explore the observed patterns.
Nosemosis in Honeybees: A Review Guide on Biology and Diagnostic Methods
Authors: Mazur Ewa Danuta , Gajda Anna Maria
Published: June 2022

Nosema apis and Nosema ceranae are dangerous parasites of the honey bee (Apis mellifera). N. ceranae is more pathogenic and, nowadays, more widespread than N. apis. There are also cases of mixed infections or infections of only N. apis. Both N. apis and N. ceranae can lead to the weakening or death of A. mellifera colonies. It is crucial to make a fast and reliable diagnosis to monitor the disease and to start the correct treatment. Additionally, there is a need for further research on the pathogenicity of Nosema spp. and also on their prevalence in different regions of the world. In this paper, we present reliable diagnostic methods for Nosema spp. infection in honey bees and list the advantages and disadvantages of each method. We have also included basic information about nosemosis and the majority of diagnostic methods in order to provide a source of knowledge for veterinarians and researchers.
Investigation of Wind-Loads Acting on Low-Aspect-Ratio Cylindrical Structures Based on a Wind Tunnel Test
Authors: Han Zhen , Li Bo , Tian Yuji , Xue Meimei , Shao Shuai
Published: June 2022

The low-aspect-ratio cylindrical structures represented by oil tanks is a kind of wind sensitive structure, which is prone to buckling under wind-loads. A wind tunnel test was conducted to investigate the properties of wind-loads acting on smooth cylinders with an aspect ratio AR = 0.323 and 0.875, respectively. Some parameters, such as Reynolds number (Re) and turbulence intensity, were taken into account. The results reveal that low-aspect-ratio cylinders have a Re effect, and the effect rises with AR. AR is the main factor affecting the value of the base pressure coefficient and positive pressure range, and the former increases with AR, while the latter decreases with AR. Moreover, due to the influence of the free end and turbulence, which may suppress vortex shedding, the power spectrum of the lift coefficient essentially shows broad spectral peaks with Re and turbulence. Increasing the incoming turbulence made the flow round cylinders at a higher Re state, that is, the supercritical regime is reached at a smaller Re. When turbulence is greater than 4.0%, turbulence and Re have little effect on the mean base force coefficient of low-aspect-ratio cylinders.
Technique Evolutions for Microorganism Detection in Complex Samples: A Review
Authors: Prada Pierre , Brunel Benjamin , Reffuveille Fany , Gangloff Sophie C.
Published: June 2022

Rapid detection of microorganisms is a major challenge in the medical and industrial sectors. In a pharmaceutical laboratory, contamination of medical products may lead to severe health risks for patients, such as sepsis. In the specific case of advanced therapy medicinal products, contamination must be detected as early as possible to avoid late production stop and unnecessary costs. Unfortunately, the conventional methods used to detect microorganisms are based on time-consuming and labor-intensive approaches. Therefore, it is important to find new tools to detect microorganisms in a shorter time frame. This review sums up the current methods and represents the evolution in techniques for microorganism detection. First, there is a focus on promising ligands, such as aptamers and antimicrobial peptides, cheaper to produce and with a broader spectrum of detection. Then, we describe methods achieving low limits of detection, thanks to Raman spectroscopy or precise handling of samples through microfluids devices. The last part is dedicated to techniques in real-time, such as surface plasmon resonance, preventing the risk of contamination. Detection of pathogens in complex biological fluids remains a scientific challenge, and this review points toward important areas for future research.
Optimal Machine Learning Based Privacy Preserving Blockchain Assisted Internet of Things with Smart Cities Environment
Authors: Al-Qarafi A. , Alrowais Fadwa , S. Alotaibi Saud , Nemri Nadhem , Al-Wesabi Fahd N. , Al Duhayyim Mesfer , Marzouk Radwa , Othman Mahmoud , Al-Shabi M.
Published: June 2022

Currently, the amount of Internet of Things (IoT) applications is enhanced for processing, analyzing, and managing the created big data from the smart city. Certain other applications of smart cities were location-based services, transportation management, and urban design, amongst others. There are several challenges under these applications containing privacy, data security, mining, and visualization. The blockchain-assisted IoT application (BIoT) is offering new urban computing to secure smart cities. The blockchain is a secure and transparent data-sharing decentralized platform, so BIoT is suggested as the optimum solution to the aforementioned challenges. In this view, this study develops an Optimal Machine Learning-based Intrusion Detection System for Privacy Preserving BIoT with Smart Cities Environment, called OMLIDS-PBIoT technique. The presented OMLIDS-PBIoT technique exploits BC and ML techniques to accomplish security in the smart city environment. For attaining this, the presented OMLIDS-PBIoT technique employs data pre-processing in the initial stage to transform the data into a compatible format. Moreover, a golden eagle optimization (GEO)-based feature selection (FS) model is designed to derive useful feature subsets. In addition, a heap-based optimizer (HBO) with random vector functional link network (RVFL) model was utilized for intrusion classification. Additionally, blockchain technology is exploited for secure data transmission in the IoT-enabled smart city environment. The performance validation of the OMLIDS-PBIoT technique is carried out using benchmark datasets, and the outcomes are inspected under numerous factors. The experimental results demonstrate the superiority of the OMLIDS-PBIoT technique over recent approaches.
A Review of Neural Network-Based Emulation of Guitar Amplifiers
Authors: Vanhatalo Tara , Legrand Pierrick , Desainte-Catherine Myriam , Hanna Pierre , Brusco Antoine , Pille Guillaume , Bayle Yann
Published: June 2022

Vacuum tube amplifiers present sonic characteristics frequently coveted by musicians, that are often due to the distinct nonlinearities of their circuits, and accurately modelling such effects can be a challenging task. A recent rise in machine learning methods has lead to the ubiquity of neural networks in all fields of study including virtual analog modelling. This has lead to the appearance of a variety of architectures tailored to this task. This article aims to provide an overview of the current state of the research in neural emulation of analog distortion circuits by first presenting preceding methods in the field and then focusing on a complete review of the deep learning landscape that has appeared in recent years, detailing each subclass of available architectures. This is done in order to bring to light future possible avenues of work in this field.
Parameter Identification of Structures with Different Connections Using Static Responses
Authors: Xiao Feng , Zhu Weiwei , Meng Xiangwei , Chen Gang S.
Published: June 2022

This paper presents a parameter-identification method for rod structures with different connections. In this method, the parameters of the structure are adjusted to match its analytical and measured displacements. The damage identification for truss structure and rigid frame were investigated. Previous studies often considered the cross-sectional area damage or joint damage; there are few studies on the simultaneous existence of these two types of damage. In this study, damage identification for a rigid frame with both cross-sectional and joint damage was performed. Based on the measured displacements, the proposed method can accurately identify the cross-sectional and joint damage for a rigid frame.
Characterization of Terrain-Induced Turbulence by Large-Eddy Simulation for Air Safety Considerations in Airport Siting
Authors: Wang Sai , De Roo Frederik , Thobois Ludovic , Reuder Joachim
Published: June 2022

Topography-induced turbulence poses a potential hazard for aviation safety, in particular during the final approach and landing. In this context, it is essential to assure that the impact of topography-induced turbulence on the flight paths during take-off and landing is minimized already during the design and planning phase. As an example of the siting and planning of a potential new airport in complex terrain, this study investigates the distribution of terrain-induced boundary layer turbulence in the vicinity of the current Lofoten airport at Leknes (LKN). For that purpose, large-eddy simulations (LES) have been performed with the PAralellized Large-eddy Simulation Model (PALM) on a 40×45×4km3 computational domain around LKN. An initial parametric sensitivity study resulted in a grid spacing of 50 m and an overall simulation time of 12 h for our individual model runs. A suite of 32 model simulations for 16 different wind directions and two geostrophic wind speeds of 10 ms−1 and 20 ms−1, was then performed and analysed. A turbulence risk analysis along idealized flight trajectories shows that the high-risk conditions are substantially determined by the wind conditions and their interaction with the topography. With respect to wind speed, the results indicate that for a geostrophic flow below 10 ms−1, the risk of aviation critical, terrain-induced boundary layer turbulence (BLT), is rather low in the vicinity of LKN. At 20 ms−1 the situation has completely changed, as for 14 out of 16 investigated wind directions the 9 m2s−2 aviation critical threshold of turbulent kinetic energy per unit air mass (TKE) is exceeded. In the northwesterly wind scenarios, the largest areas with critical turbulence in the vicinity of LKN are observed.
Reversion of MRAP2 Protein Sequence Generates a Functional Novel Pharmacological Modulator for MC4R Signaling
Authors: Xu Jing , Wang Meng , Fu Yanbin , Zhang Cong , Kuang Zhe , Bian Shan , Wan Rui , Qu Shen , Zhang Chao
Published: June 2022

As a member of the melanocortin receptor family, melanocortin 4 receptor (MC4R) plays a critical role in regulating energy homeostasis and feeding behavior, and has been proven as a promising therapeutic target for treating severe obesity syndrome. Numerous studies have demonstrated that central MC4R signaling is significantly affected by melanocortin receptor accessory protein 2 (MRAP2) in humans, mice and zebrafish. MRAP2 proteins exist as parallel or antiparallel dimers on the plasma membrane, but the structural insight of dual orientations with the pharmacological profiles has not yet been fully studied. Investigation and optimization of the conformational topology of MRAP2 are critical for the development of transmembrane allosteric modulators to treat MC4R-associated disorders. In this study, we synthesized a brand new single transmembrane protein by reversing wild-type mouse and zebrafish MRAP2 sequences and examined their dimerization, interaction and pharmacological activities on mouse and zebrafish MC4R signaling. We showed that the reversed zebrafish MRAPa exhibited an opposite function on modulating zMC4R signaling and the reversed mouse MRAP2 lost the capability for regulating MC4R trafficking but exhibited a novel function for cAMP cascades, despite proper expression and folding. Taken together, our results provided new biochemical insights on the oligomeric states and membrane orientations of MRAP2 proteins, as well as its pharmacological assistance for modulating MC4R signaling.
A fresh look at the Hyolithid Doliutheca from the Early Cambrian (Stage 4) Shipai Formation of the Three Gorges Area, Hubei, South China
Authors: Liu Fan , Skovsted Christian , Topper Timothy , Zhang Zhifei
Published: June 2022

New hyolith specimens from the early Cambrian (Stage 4) of the Three Gorges area, western Hubei Province are described and assigned to the species Doliutheca orientalis. Doliutheca are preserved in two taphonomic modes: casts in silty mudstone revealing gross morphology and some soft parts, and internal molds in calcareous pelites, which exhibit new morphological details of the conch and operculum. SEM and Micro-CT analyses show that Doliutheca preserve well-developed platy clavicles and cardinal processes on the interior of the operculum composed of rod-shaped tubular elements. This observation and the distinct cardinal and conical shields of the operculum indicate that Doliutheca could be placed within the Family Paramicrocornidae, most recently established as a group of hyoliths closely related to hyolithids.
Histochemical Evidence for Nitrogen-Transfer Endosymbiosis in Non-Photosynthetic Cells of Leaves and Inflorescence Bracts of Angiosperms
Authors: Micci April , Zhang Qiuwei , Chang Xiaoqian , Kingsley Kathryn , Park Linsey , Chiaranunt Peerapol , Strickland Raquele , Velazquez Fernando , Lindert Sean , Elmore Matthew , Vines Philip L. , Crane Sharron , Irizarry Ivelisse , Kowalski Kurt P. , Johnston-Monje David , White James F.
Published: June 2022

We used light and confocal microscopy to visualize bacteria in leaf and bract cells of more than 30 species in 18 families of seed plants. Through histochemical analysis, we detected hormones (including ethylene and nitric oxide), superoxide, and nitrogenous chemicals (including nitric oxide and nitrate) around bacteria within plant cells. Bacteria were observed in epidermal cells, various filamentous and glandular trichomes, and other non-photosynthetic cells. Most notably, bacteria showing nitrate formation based on histochemical staining were present in glandular trichomes of some dicots (e.g., Humulus lupulus and Cannabis sativa). Glandular trichome chemistry is hypothesized to function to scavenge oxygen around bacteria and reduce oxidative damage to intracellular bacterial cells. Experiments to assess the differential absorption of isotopic nitrogen into plants suggest the assimilation of nitrogen into actively growing tissues of plants, where bacteria are most active and carbohydrates are more available. The leaf and bract cell endosymbiosis types outlined in this paper have not been previously reported and may be important in facilitating plant growth, development, oxidative stress resistance, and nutrient absorption into plants. It is unknown whether leaf and bract cell endosymbioses are significant in increasing the nitrogen content of plants. From the experiments that we conducted, it is impossible to know whether plant trichomes evolved specifically as organs for nitrogen fixation or if, instead, trichomes are structures in which bacteria easily colonize and where some casual nitrogen transfer may occur between bacteria and plant cells. It is likely that the endosymbioses seen in leaves and bracts are less efficient than those of root nodules of legumes in similar plants. However, the presence of endosymbioses that yield nitrate in plants could confer a reduced need for soil nitrogen and constitute increased nitrogen-use efficiency, even if the actual amount of nitrogen transferred to plant cells is small. More research is needed to evaluate the importance of nitrogen transfer within leaf and bract cells of plants.
Trematodes of Genera Gyrabascus and Parabascus from Bats in European Russia: Morphology and Molecular Phylogeny
Authors: Kirillova Nadezhda Yu. , Shchenkov Sergei V. , Kirillov Alexander A. , Ruchin Alexander B.
Published: June 2022

Morphological variability of trematodes from bats (Chiroptera) is poorly studied. Since the variability of adult digenean specimens may be rather high, morphological features are often insufficient for the identification of closely related species, and confirmation with the use of molecular data is required. The aim of our study was to combine the morphological and molecular phylogenetic analyses of several bat trematodes from the genera Gyrabascus and Parabascus (Pleurogenidae): Gyrabascus amphoraeformis, Gyrabascus oppositus, Parabascus lepidotus, Parabascus duboisi, and Parabascus semisquamosus, of which G. amphoraeformis and G. oppositus are little known in European Russia. We made detailed morphological descriptions of these trematodes from several definitive hosts, analyzed morphometric features, and generated new partial sequences of the 28S rRNA gene. A broad variability of trematodes of the genera Gyrabascus and Parabascus was revealed both from various host species and from specimens of the same host species. We propose a new taxonomic key for the identification of the studied species. Certain host specificity of these trematodes was revealed.
Biotransformation of Androstenedione by Filamentous Fungi Isolated from Cultural Heritage Sites in the State Tretyakov Gallery
Authors: Zhgun Alexander A. , Potapov Mark P. , Avdanina Darya A. , Karpova Natalya V. , Yaderets Vera V. , Dzhavakhiya Vakhtang V. , Kardonsky Dmitry A.
Published: June 2022

The transformation of steroids by microorganisms is widely used in medical biotechnology. A huge group of filamentous fungi is one of the most promising taxa for screening new biocatalytic reactions in order to obtain pharmaceutically significant steroids. In this work, we screened 10 filamentous fungi-destructors of egg tempera for the ability to biotransform androst-4-en-3,17-dione (AD) during cultivation in a liquid nutrient medium or in a buffer solution. These taxonomically unrelated strains, belonging to the classes Eurotiomycetes, Dothideomycetes and Sordariomycetes, are dominant representatives of the microbiome from halls where works of tempera painting are stored in the State Tretyakov Gallery (STG, Moscow, Russia). Since the binder of tempera paints, egg yolk, contains about 2% cholesterol, these degrading fungi appear to be a promising group for screening for steroid converting activity. It turned out that all the studied fungi-destructors are able to transform AD. Some strains showed transformation efficiency close to the industrial strain Curvularia lunata RNCIM F-981. In total, 33 steroids formed during the transformation of AD were characterized, for 19 of them the structure was established by gas chromatography/mass spectrometry analysis. In this work, we have shown for the first time that fungi-destructors of tempera paintings can efficiently transform steroids.
Identification and Characterization of a New Microalga Dysmorphococcus globosus-HI from the Himalayan Region as a Potential Source of Natural Astaxanthin
Authors: Zohir Wafaa F. , Kapase Vikas U. , Kumar Shashi
Published: June 2022

Synthesized astaxanthin (ASX), stereoisomers of 3S,3′R, 3R,3′R, and 3S,3′S, have over 95% market share and have relatively poor antioxidant and bioactivity properties, with persistent issues in terms of biological functions, health benefits, and biosafety if compared to natural ASX. Bioprospecting of new microalgal strains could be vital for a new source of powerful antioxidant (ASX). In this study, a new algal strain was isolated from the Indian foothills of the Himalayas. Its identity was discerned by morphological and DNA barcode studies. It is a unicellular spheroidal cell-shaped alga with 100–200 μm diameter. The isolate has 93.4% similarity to Dysmorphococcus globosus species based on 18S-rDNA phylogenetic analysis and named as D. globosus-HI (HI stands for Himalayan India). Its growth and major cellular components (carotenoids, carbohydrates, protein, lipids, fatty acid profile, and ASX) were optimized using the seven different culture media. The highest biomass (1.14 g L−1) was observed in the MBBM medium, with a specific growth rate (0.087 day−1), division/day (0.125), and cellular yield (6.16 x 106 cells/mL). The highest carotenoids (1.56 mg g−1), lipids (32.5 mg L−1), and carbohydrates (135.62 mg L−1) were recorded in the 3N-BBM medium. The maximum ω3-FAs (17.78%), ω6-FAs (23.11%), and ω9-FAs (7.06%) were observed in MBBM, JW, and BG-11 medium respectively. The highest amount of antioxidant ASX was accumulated in the 3N-BBM medium (391 mg L−1). It is more than any other known algal species used in the production of natural ASX. The optimized biochemical studies on the D. globosus-HI strain should fulfill the increasing demand for natural ASX for commercial application.
Taxonomic and Phylogenetic Insights into Novel Ascomycota from Forest Woody Litter
Authors: Wanasinghe Dhanushka N. , Mortimer Peter E.
Published: June 2022

While surveying the mycobiomes of dead woody litter in Yunnan Province, China, numerous isolates with affinity to Pleosporales (Dothideomycetes, Ascomycota) were recovered. The present work characterizes two species associated with dead woody twigs found in terrestrial habitats in the Kunming area of Yunnan. The novel taxa were recognized based on a polyphasic approach, including morphological examination and multiple gene phylogenetic analyses (non-translated loci and protein-coding regions). Neokalmusia jonahhulmei sp. nov. is introduced in Didymosphaeriaceae (Pleosporales) as a woody-based saprobic ascomycete that possesses multiloculate ascostromata immersed under a black clypeus-like structure, and three-septate, brown, fusiform, guttulate ascospores. Thyridaria jonahhulmei (Thyridariaceae) is introduced with teleomorphic and anamorphic (coelomycetous) characteristics. The teleomorph has the following characteristics: globose to subglobose ascomata with an ostiolum, a pruinose layer of yellow to reddish- or orange-brown material appearing around the top of the ostiolar necks, and brown, ellipsoid to fusoid, two-to-three-septate, euseptate, rough-walled ascospores; the anamorph features pycnidial conidiomata, phialidic, ampulliform to doliiform, conidiogenous cells, and brown, guttulate, ellipsoidal, aseptate conidia.
The Repeating, Modular Architecture of the HtrA Proteases
Authors: Merski Matthew , Macedo-Ribeiro Sandra , Wieczorek Rafal M. , Górna Maria W.
Published: June 2022

A conserved, 26-residue sequence [AA(X2)[A/G][G/L](X2)GDV[I/L](X2)[V/L]NGE(X1)V(X6)] and corresponding structure repeating module were identified within the HtrA protease family using a non-redundant set (N = 20) of publicly available structures. While the repeats themselves were far from sequence perfect, they had notable conservation to a statistically significant level. Three or more repetitions were identified within each protein despite being statistically expected to randomly occur only once per 1031 residues. This sequence repeat was associated with a six stranded antiparallel β-barrel module, two of which are present in the core of the structures of the PA clan of serine proteases, while a modified version of this module could be identified in the PDZ-like domains. Automated structural alignment methods had difficulties in superimposing these β-barrels, but the use of a target human HtrA2 structure showed that these modules had an average RMSD across the set of structures of less than 2 Å (mean and median). Our findings support Dayhoff’s hypothesis that complex proteins arose through duplication of simpler peptide motifs and domains.
Influence of Carbon Sources on the Phenolic Compound Production by Euglena gracilis Using an Untargeted Metabolomic Approach
Authors: Bernard Eve , Guéguen Céline
Published: June 2022

Industrial development and urbanization has led to the diverse presence of metals in wastewater that are often improperly treated. The microalgae Euglena gracilis can tolerate high concentrations of metal via the excretion of organic metabolites, including phenolics. This study aims to evaluate how carbon amendment stimulates phenolic compound production by E. gracilis. The number, relative intensity and molecular composition of the phenolic compounds were significantly different between each of four carbon amended cultures (i.e., glutamic acid, malic acid, glucose, reduced glutathione) during the log phase. Phenolic compounds were mainly produced during the minimum growth rate, likely a response to stressful conditions. A better understanding of phenolic compounds production by E. gracilis and the impact of growth conditions will help identify conditions that favor certain phenolic compounds for dietary and metal chelation applications.
Gamma-Linolenic Acid (GLA) Protects against Ionizing Radiation-Induced Damage: An In Vitro and In Vivo Study
Authors: Rengachar Poorani , Bhatt Anant Narayan , Polavarapu Sailaja , Veeramani Senthil , Krishnan Anand , Sadananda Monika , Das Undurti N.
Published: June 2022

Radiation is pro-inflammatory in nature in view of its ability to induce the generation of reactive oxygen species (ROS), cytokines, chemokines, and growth factors with associated inflammatory cells. Cells are efficient in repairing radiation-induced DNA damage; however, exactly how this happens is not clear. In the present study, GLA reduced DNA damage (as evidenced by micronuclei formation) and enhanced metabolic viability, which led to an increase in the number of surviving RAW 264.7 cells in vitro by reducing ROS generation, and restoring the activities of desaturases, COX-1, COX-2, and 5-LOX enzymes, TNF-α/TGF-β, NF-kB/IkB, and Bcl-2/Bax ratios, and iNOS, AIM-2, and caspases 1 and 3, to near normal. These in vitro beneficial actions were confirmed by in vivo studies, which revealed that the survival of female C57BL/6J mice exposed to lethal radiation (survival~20%) is significantly enhanced (to ~80%) by GLA treatment by restoring altered levels of duodenal HMGB1, IL-6, TNF-α, and IL-10 concentrations, as well as the expression of NF-kB, IkB, Bcl-2, Bax, delta-6-desaturase, COX-2, and 5-LOX genes, and pro- and anti-oxidant enzymes (SOD, catalase, glutathione), to near normal. These in vitro and in vivo studies suggest that GLA protects cells/tissues from lethal doses of radiation by producing appropriate changes in inflammation and its resolution in a timely fashion.