bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphometry of Boar Spermatozoa in Semen Stored at 17 °C—The Influence of the Staining Technique
Authors: Szablicka Dorota , Wysokińska Anna , Pawlak Angelika , Roman Klaudia
Published: July 2022

The aim of the study was to assess the morphometry of sperm during storage of liquid boar semen at 17 °C. An attempt was also made to evaluate the suitability of three staining methods for assessment of boar sperm morphometry. The study was carried out on 20 Landrace boars. Semen was collected from the boars every 5 days by the manual method. Four ejaculates from each boar were analysed (80 ejaculates in total). Analyses were performed five times: at 1 h, 24 h, 48 h, 96 h, and 168 h after semen collection. Blisters with insemination doses were opened immediately before the analyses. From each insemination dose, smears were prepared for morphometric evaluation of sperm, which were stained by three methods (eosin-nigrosin—EN, eosin-gentian—EG, and SpermBlue—SB). Morphometric measurements of 15 randomly selected sperm with normal morphology were performed on each slide. The morphometric measurements included the following parameters: sperm head length, width, area, and perimeter; tail length; and total sperm length. The results of the morphometric measurements were used to calculate the head shape index. The morphometric dimensions of the sperm were shown to change during storage of semen at 17 °C. The extent of these changes, however, depended on the staining method used, as the three methods result in different morphometric dimensions of sperm, in the case of both the head and the tail. In the slides stained by the eosin-nigrosin method, the dimensions of the head and tail were smaller at every time of storage than in the slides stained by the SpermBlue and eosin-gentian methods.
Antibiotic Use and Bacterial Infection in COVID-19 Patients in the Second Phase of the SARS-CoV-2 Pandemic: A Scoping Review
Authors: Cong Wenjuan , Stuart Beth , AIhusein Nour , Liu Binjuan , Tang Yunyi , Wang Hexing , Wang Yi , Manchundiya Amit , Lambert Helen
Published: July 2022

This scoping review aimed to explore the prevalence and patterns of global antibiotic use and bacterial infection in COVID-19 patients from studies published between June 2020 and March 2021. This review was reported in line with the Preferred Reporting of Systematic Reviews and Meta-Analyses (PRISMA) extension for Scoping Reviews, and the protocol is registered with the Open Science Framework. Compared with our previously-published review of the period (December 2019–June 2020), the antibiotic prescribing rate for COVID-19 patients (June 2020–March 2021) was found to have declined overall (82.3% vs. 39.7%), for mild and moderate patients (75.1% vs. 15.5%), and for severe and critical patients (75.3% vs. 48.3%). The seven most frequently prescribed antibiotics in COVID-19 patients were all on the “Watch” list of the WHO AWaRe antibiotics classification. The overall reported bacterial infection rate in COVID-19 patients was 10.5%, and the most frequently reported resistant pathogen in COVID-19 patients was Staphylococcus aureus, followed by Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae. There is an urgent need to establish comprehensive and consistent guidelines to assist clinicians in selecting appropriate antibiotics for COVID-19 patients when needed. The resistance data on the most frequently used antibiotics for COVID-19 patients for certain resistant pathogens should be closely monitored.
Blood Culture Headspace Gas Analysis Enables Early Detection of Escherichia coli Bacteremia in an Animal Model of Sepsis
Authors: Euler Maximilian , Perl Thorsten , Eickel Isabell , Dudakova Anna , Maguilla Rosado Esther , Drees Carolin , Vautz Wolfgang , Wieditz Johannes , Meissner Konrad , Kunze-Szikszay Nils
Published: July 2022

(1) Background: Automated blood culture headspace analysis for the detection of volatile organic compounds of microbial origin (mVOC) could be a non-invasive method for bedside rapid pathogen identification. We investigated whether analyzing the gaseous headspace of blood culture (BC) bottles through gas chromatography-ion mobility spectrometry (GC-IMS) enables differentiation of infected and non-infected; (2) Methods: BC were gained out of a rabbit model, with sepsis induced by intravenous administration of E. coli (EC group; n = 6) and control group (n = 6) receiving sterile LB medium intravenously. After 10 h, a pair of blood cultures was obtained and incubated for 36 h. The headspace from aerobic and anaerobic BC was sampled every two hours using an autosampler and analyzed using a GC-IMS device. MALDI-TOF MS was performed to confirm or exclude microbial growth in BCs; (3) Results: Signal intensities (SI) of 113 mVOC peak regions were statistically analyzed. In 24 regions, the SI trends differed between the groups and were considered to be useful for differentiation. The principal component analysis showed differentiation between EC and control group after 6 h, with 62.2% of the data variance described by the principal components 1 and 2. Single peak regions, for example peak region P_15, show significant SI differences after 6 h in the anaerobic environment (p < 0.001) and after 8 h in the aerobic environment (p < 0.001); (4) Conclusions: The results are promising and warrant further evaluation in studies with an extended microbial panel and indications concerning its transferability to human samples.
Modulation of Multiple Gene Clusters’ Expression by the PAS-LuxR Transcriptional Regulator PteF
Authors: Vicente Cláudia M. , Payero Tamara D. , Rodríguez-García Antonio , Barreales Eva G. , Pedro Antonio de , Santos-Beneit Fernando , Aparicio Jesús F.
Published: July 2022

PAS-LuxR transcriptional regulators are conserved proteins governing polyene antifungal biosynthesis. PteF is the regulator of filipin biosynthesis from Streptomyces avermitilis. Its mutation drastically abates filipin, but also oligomycin production, a macrolide ATP-synthase inhibitor, and delays sporulation; thus, it has been considered a transcriptional activator. Transcriptomic analyses were performed in S. avermitilis ΔpteF and its parental strain. Both strains were grown in a YEME medium without sucrose, and the samples were taken at exponential and stationary growth phases. A total of 257 genes showed an altered expression in the mutant, most of them at the exponential growth phase. Surprisingly, despite PteF being considered an activator, most of the genes affected showed overexpression, thereby suggesting a negative modulation. The affected genes were related to various metabolic processes, including genetic information processing; DNA, energy, carbohydrate, and lipid metabolism; morphological differentiation; and transcriptional regulation, among others, but were particularly related to secondary metabolite biosynthesis. Notably, 10 secondary metabolite gene clusters out of the 38 encoded by the genome showed altered expression profiles in the mutant, suggesting a regulatory role for PteF that is wider than expected. The transcriptomic results were validated by quantitative reverse-transcription polymerase chain reaction. These findings provide important clues to understanding the intertwined regulatory machinery that modulates antibiotic biosynthesis in Streptomyces.
Understanding Antibiotic Resistance as a Perceived Threat towards Dairy Cattle through Beliefs and Practices: A Survey-Based Study of Dairy Farmers
Authors: Casseri Eleni , Bulut Ece , Llanos Soto Sebastian , Wemette Michelle , Stout Alison , Greiner Safi Amelia , Lynch Robert , Moroni Paolo , Ivanek Renata
Published: July 2022

Antibiotic use is an important component in dairy herd management both to treat bacterial diseases and to maximize animal welfare. However, there is concern among scientists that antibiotic misuse and/or overuse by farmers might promote the emergence of resistant pathogens. We conducted a cross-sectional web-based questionnaire study with dairy farmers/managers in New York, USA to evaluate their (i) level of concern about antibiotic resistance and (ii) interest in adopting new judicious antibiotic use practices regarding mastitis treatment. A total of 118 responses were subjected to statistical analysis. The findings revealed that nearly half (45%) of study participants were undecided or disagreed that antibiotic resistance due to antibiotic use in dairy farming may negatively impact the health of dairy cattle. In contrast, the majority (78%) of participants self-reported that they do not treat with antibiotics at the first sign of mastitis, and the majority (66%) have either fully or partially implemented culture-based mastitis treatment on their farm. The self-reported adoption of culture-based mastitis treatment practices was statistically significantly associated with higher numbers of injectable and intramammary doses of antibiotics used on the participants’ farms. These findings will aid future research investigations on how to promote sustainable antibiotic use practices in dairy cattle.
Global Spread of MCR-Producing Salmonella enterica Isolates
Authors: Zhang Zengfeng , Tian Xiaorong , Shi Chunlei
Published: July 2022

Colistin resistance in bacteria has become a significant threat to food safety and public health, and its development was mainly attributed to the plasmid-mediated mcr genes. This study aimed to determine the global prevalence and molecular characteristics of mcr-producing Salmonella enterica isolates. A total of 2279 mcr-producing Salmonella genomes were obtained from the public database, which were disseminated in 37 countries from five continents worldwide, including Asia, Europe, America, Australia, and Africa. Human samples (39.5%; 900/2279) were the predominant sources of mcr-producing Salmonella isolates, followed by foods (32.6%), animals (13.7%), and environment (4.4%). Furthermore, 80 Salmonella serotypes were identified, and Typhimurium and 1,4,[5],12:i:- were the predominant serotypes, accounting for 18.3% and 18.7%, respectively. Twenty mcr variants were identified, and the most common ones were mcr-9.1 (65.2%) and mcr-1.1 (24.4%). Carbapenems-resistance gene blaNDM-1 and tigecycline-resistance gene tet(X4) were identified in one isolate, respectively. Phylogenetic results indicated that mcr-producing Salmonella fell into nine lineages (Lineages I-IX), and Salmonella Typhimurium, 1,4,[5],12:i:- and 4,[5],12:i:- isolates from different countries were mixed in Lineages I, II and III, suggesting that international spread occurred. These findings underline further challenges for the spread of Salmonella-bearing mcr genes.
Solving the Container Relocation Problem by Using a Metaheuristic Genetic Algorithm
Authors: Gulić Marko , Maglić Livia , Krljan Tomislav , Maglić Lovro
Published: July 2022

Maritime transport is the backbone of international trade of goods. Therefore, seaports are of great importance for maritime transport. Container transport plays an important role in maritime transport and is increasing year by year. Containers transported to a container terminal are stored in container yards side by side and on top of each other, forming blocks. If a container that is not on top of the block has to be retrieved, the containers that are above the required container must be relocated before the required container is retrieved. These additional container relocations, which block the retrieval of the required container, slow down the entire retrieval process. The container relocation problem, also known as the block relocation problem, is an optimization problem that involves finding an optimal sequence of operations for retrieving blocks (containers) from a container yard in a given order, minimizing additional relocations of blocking containers. In this paper, the focus is on the two-dimensional, static, offline and the restricted container relocation problem of real-size yard container bays. A new method for resolving the container relocation problem that uses a genetic algorithm is proposed to minimize the number of relocations within the bay. The method is evaluated on well-known test instances, and the obtained results are compared with the results of various relevant models for resolving the container relocation problem. The results show that the proposed method achieves the best or the second-best result for each test instance within the test set.
Simulation Study of Thermal–Mechanical Coupling Fretting Wear of Ti-6Al-4V Alloy
Authors: Li Ling , Zhang Wang , Li Ganghua , Wang Jingjing , Li Lixia , Xie Miaoxia
Published: July 2022

Fretting wear phenomenon has a non-negligible impact on the reliability of the contact parts of mechanical power systems. The impact of temperature increases in actual working conditions is taken into consideration in order to increase the accuracy of fretting wear prediction. Temperature-dependent wear coefficients were added to the energy dissipation wear model, and the UMESHMOTION subroutine was created. A temperature-displacement-coupled finite element model of fretting wear is established based on a cylinder/plane fretting test of Ti-6Al-4V alloy materials. The model takes into account the interaction between temperature, stress, and wear. The effects of the plastic deformation of materials, temperature, number of cycles, fretting velocity, and variable normal load on wear and temperature rise are explored. The results show that the wear amount is small when the temperature rises, and the plastic deformation of materials is not considered. The wear profile is no longer a smooth Hertzian shape when the plastic deformation of materials is considered. The amount of wear increases with the fretting speed and the number of cycles. Meanwhile, the temperature of the contact area and the surface near the contact area increases with the increase in fretting speed. Peak temperature rise of the contact surface increases with the number of cycles, and its horizontal position moves with the cylinder specimen. Furthermore, the wear profile is less smooth under the variable normal load, but the two variable normal loads in the same phase have similar wear profiles and temperature rise distributions. The theoretical resources provided by the research work can be used to design control strategies and optimize mechanical power systems.
CoR-SketchAR: Cooperative Sketch-Based Real-Time Augmented Reality Authoring Tool for Crowd Simulation
Authors: Kim Gahyeon , Sung Mankyu
Published: July 2022

In this study, we propose CoR-SketchAR, an augmented reality (AR) environment authoring tool that uses dry-erase markers for real-time collaboration among users. The most important requirement for multi-user collaboration in an AR environment is that the 3D virtual object must be placed at a specific location and can be easily changed by multiple users. Because marker-based registration techniques, which are widely used for matching virtual objects with real ones, require a marker for each object, and creating a crowd simulation environment with objects of various shapes and sizes requires the use of a large number of markers, which is time consuming and expensive. CoR-SketchAR, instead, creates an urban AR environment by drawing sketches with easily altered dry-erase marker. Then, system recognizes the shapes and colors of the sketches automatically. Those recognized shapes and colors provide the exact positions for overlaying the 3D virtual objects, which are the environment factors, on the real environment in augmented reality manner. We can even specify the path the crowd are moving along with a simple sketch stroke. We apply the computer vision technique to recognize the colors and shapes of sketches. By altering the size, shape and color sketches, the system is able to create a wide variety of dynamic urban environments. To validate the proposed techniques, we built two stand-alone software systems to check the usability of the proposed system (a 2D screen-based environmental authoring tool and a sketch-based environmental authoring tool) and conducted experiments in which two users collaborated with each other to create an environment with a specific authoring tool and then report surveys. In the experiments, users collaborated in pairs to create environmental elements, such as highways, buildings, trees, and the starting and goal positions of crowds. After recognizing them, the system then automatically creates a 3D environment, and crowds are animated accordingly. Based on a user survey, we observed that participants who used sketch-based environmental authoring tools were more active and accessible than those who used 2D screen-based authoring tools. The results of the study show that CoR-SketchAR can be further used to create a dynamical crowd simulation on a large scale using beam projectors or portable devices by simply adding sketches based on different scenarios.
Preparation and Properties of Polyurethane Composite Foams with Silica-Based Fillers
Authors: Lee Dong Ik , Ha Yeon Hee , Jeon Hanyong , Kim Seung Hyun
Published: July 2022

Polyurethane composite foams were prepared by adding three different types of silica materials as a filler to improve the mechanical and thermal insulation properties. The first type of filler consists of silica aerogels with high-volume pores, with the expectation of improving the thermal insulation of PU foams because silica aerogel itself has superior thermal insulation properties. Silica nanoparticle is used for the second type that has a size very similar to the pore size of silica aerogels for comparison. The last type to produce polyurethane composite foam uses a sol–gel reaction to produce polysiloxane that reacts with polyols during the urethane reaction and forming process. In particular, in the case of silica aerogels and nanoparticles, their surfaces are modified with APTES and then polymeric methylene diphenylene diisocyanate (PMDI) to increase the interaction between the polymer matrix and inorganic fillers. The polyurethane foam structure was successfully produced in all cases of composite foams. As expected, the mechanical properties and the thermal insulation effect were enhanced by the addition of silica fillers, but found to be closely related to the cell structure of polyurethane foams. The addition of small amounts of inorganic fillers improves the mechanical and thermal properties, but the higher the amount of filler, the worse they are due to the agglomeration of fillers on the cell walls. The dispersion of added inorganic fillers within the foam cells should be controlled effectively. Surface-modified silica fillers exhibit better enhancement of mechanical and thermal insulation properties.
Numerical Analysis Exterior RC Beam-Column Joints with CFRP Bars as Beam’s Tensional Reinforcement under Cyclic Reversal Deformations
Authors: Kytinou Violetta K. , Kosmidou Parthena-Maria K. , Chalioris Constantin E.
Published: July 2022

In this paper the cyclic lateral response of reinforced concrete (RC) beam-column joints with composite carbon fiber-reinforced polymer (CFRP) bars as a longitudinal reinforcement in the beam is simulated with finite element (FE) modeling using software Abaqus. An experimental project of two full-scale joint specimens subjected to cyclic loading with supplementary accompanying pull-out tests of CFRP bars is also included in this study. These test results are used to calibrate the developed FE model, the constitutive laws of the materials and the bond response between CFRP bars and concrete. Comparisons between test data and numerical results indicate that the calibrated model accurately predicts the cyclic response of RC beam-column joint specimens with CFRP longitudinal bars as the beam’s tensional reinforcement. A parametric analysis is also performed to provide useful concluding remarks concerning the design of concrete joints with composite bars and the ability of CFRP bars to substitute for conventional steel bars in RC structural members under seismic excitations.
Multi-Armed-Bandit Based Channel Selection Algorithm for Massive Heterogeneous Internet of Things Networks
Authors: Hasegawa So , Kitagawa Ryoma , Li Aohan , Kim Song-Ju , Watanabe Yoshito , Shoji Yozo , Hasegawa Mikio
Published: July 2022

In recent times, the number of Internet of Things devices has increased considerably. Numerous Internet of Things devices generate enormous traffic, thereby causing network congestion and packet loss. To address network congestion in massive Internet of Things systems, an efficient channel allocation method is necessary. Although some channel allocation methods have already been studied, as far as we know, there is no research focusing on the implementation phase of Internet of Things devices while considering massive heterogeneous Internet of Things systems where different kinds of Internet of Things devices coexist in the same Internet of Things system. This paper focuses on the multi-armed-bandit-based channel allocation method that can be implemented on resource-constrained Internet of Things devices with low computational processing ability while avoiding congestion in massive Internet of Things systems. This paper first evaluates some well-known multi-armed-bandit-based channel allocation methods in massive Internet of Things systems. The simulation results show that an improved multi-armed-bandit-based channel selection method called Modified Tug of War can achieve the highest frame success rate in most cases. Specifically, the frame success rate can reach 95% when the numbers of channels and IoT devices are 60 and 10,000, respectively, while 12% channels are suffering traffic load by other kinds of IoT devices. In addition, the performance in terms of frame success rate can be improved by 20% compared to the equality channel allocation. Moreover, the multi-armed-bandit-based channel allocation methods is implemented on 50 Wi-SUN Internet of Things devices that support IEEE 802.15.4g/4e communication and evaluate the performance in frame success rate in an actual wood house coexisting with LoRa devices. The experimental results show that the modified multi-armed-bandit method can achieve the highest frame success rate compared to other well-known frame success rate-based channel selection methods.
Calculation Model for Estimation of Residual Bearing Capacity of Damaged Reinforced Concrete Slender Columns
Authors: Kos Zeljko , Klymenko Yevhenii , Crnoja Anđelko , Grynyova Iryna
Published: July 2022

This work is devoted to the study of the influences of various parameters on the bearing capacities of compressed reinforced concrete columns of varying flexibilities damaged during operation. Experimental tests of pilot samples were carried out, and results were analyzed on the basis of which it was established that significant longitudinal bending was observed in the direction of the x-axis. By analyzing the influences of the angle and depth of damage on the behavior and nature of the destruction in the experimental samples, three main destruction patterns were identified. An analysis of the experimental and statistical models showed that the greatest influences on the bearing capacity of the samples were the depth of the damage and the angle of the cut, and the effect of the height of the samples was virtually negligible. A model of calculation for the residual bearing capacities of compressed damaged reinforced concrete elements of different flexibilities was developed. The results of the comparison testify to the good coincidence of the theoretical values with the values obtained from the actual experiment (the difference of an average of no more than 29.8%), indicating that the proposed method can be applied in building practice.
Identification of Multimodal Dynamic Characteristics of a Decurrent Tree with Application to a Model-Scale Wind Tunnel Study
Authors: Li Zhengnong , Hao Yanfeng , Kopp Gregory A. , Wu Chieh-Hsun
Published: July 2022

Wind tunnel tests of scaled model trees provide an effective approach for understanding fluctuating wind loading and wind-induced response of trees. For decurrent trees, vague multimodal dynamic characteristics and ineffective estimation of leaf mass are two of the main obstacles to developing aeroelastic models. In this study, multimodal dynamic characteristics of the decurrent tree are identified by field measurements and finite element models (FEM). It was found that the number of branches swaying in phase determines the magnitude of effective mass fraction of branch modes. The frequencies of branch modes with larger effective mass fraction were considered as a reference for an aeroelastic model. In addition, an approach to estimate leaf mass without destruction was developed by comparing trunk frequency between field measurements and FEM. Based on these characteristics of the prototype, the scaled, aeroelastic model was constructed and assessed. It was found that the mismatch of leaf stiffness between the model and the prototype leads to mismatch of leaf streamlining and damping between them. The Vogel exponent associated with leaf streamlining provides a possible way to ensure consistency of leaf stiffness between the model and prototype.
The Relation between Induced Electric Field and TMS-Evoked Potentials: A Deep TMS-EEG Study
Authors: Vlachos Ioannis , Tzirini Marietta , Chatzikyriakou Evangelia , Markakis Ioannis , Rouni Maria Anastasia , Samaras Theodoros , Roth Yiftach , Zangen Abraham , Rotenberg Alexander , Kugiumtzis Dimitris , Kimiskidis Vasilios K.
Published: July 2022

Transcranial magnetic stimulation (TMS) in humans induces electric fields (E-fields, EF) that perturb and modulate the brain’s endogenous neuronal activity and result in the generation of TMS-evoked potentials (TEPs). The exact relation of the characteristics of the induced E-field and the intensity of the brains’ response, as measured by electroencephalography (EEG), is presently unclear. In this pilot study, conducted on three healthy subjects and two patients with generalized epilepsy (total: 3 males, 2 females, mean age of 26 years; healthy: 2 males, 1 female, mean age of 25.7 years; patients: 1 male, 1 female, mean age of 26.5 years), we investigated the temporal and spatial relations of the E-field, induced by single-pulse stimuli, and the brain’s response to TMS. Brain stimulation was performed with a deep TMS device (BrainsWay Ltd., Jerusalem, Israel) and an H7 coil placed over the central area. The induced EF was computed on personalized anatomical models of the subjects through magneto quasi-static simulations. We identified specific time instances and brain regions that exhibit high positive or negative associations of the E-field with brain activity. In addition, we identified significant correlations of the brain’s response intensity with the strength of the induced E-field and finally prove that TEPs are better correlated with E-field characteristics than with the stimulator’s output. These observations provide further insight in the relation between E-field and the ensuing cortical activation, validate in a clinically relevant manner the results of E-field modeling and reinforce the view that personalized approaches should be adopted in the field of non-invasive brain stimulation.
Analysis of the Influence of a Powertrain Mounting System on a Dual-Clutch Transmission Vehicle under Typical Working Conditions
Authors: Guo Zheng , Qin Datong , Li Antai , Feng Jihao , Liu Yonggang
Published: July 2022

The unsuitably designed powertrain mount may cause jittering and shrugging during the starting and shifting processes of the vehicle, which seriously affects the comfort of using the vehicle. However, the influence of mounts on vehicles has been neglected in previous studies. In view of the above problems, this study establishes a DCT vehicle coupling dynamic model, considering six degrees of freedom of the powertrain mount and the engine dynamic torque, nonlinear characteristics of a dual-mass flywheel, time-varying stiffness of gear systems, and other factors. Furthermore, the effect of mounts on the longitudinal dynamic characteristics of the vehicle is studied during the starting, shifting, and tip-in/tip-out process. The results show that under typical working conditions, the mount and its stiffness and damping affect the fluctuation frequency and amplitude of the jerk. When the torque of the vehicle transmission system changes greatly, such as under starting and tip-in/tip-out conditions, the mount has a great impact on the dynamic performance of the vehicle. Simultaneously, the engine torque fluctuation can act on the vehicle through the mount, which has an impact on the jerk of the vehicle. A comparison with vehicle test results reveals that the DCT coupling dynamic model can reflect the law of the effect of the mount on the vehicle performance and verify the rationality of the model. Under typical working conditions, when the influence of the mount is not considered in the vehicle dynamic’s modeling, there is a large error of the jerk between the simulation results and the actual situation. The results provide a reference for optimizing the parameters of the mount and improving the dynamic characteristics of DCT vehicles.
Northern Hemisphere Extratropical Cyclone Activity in the Twentieth Century Reanalysis Version 3 (20CRv3) and Its Relationship with Continental Extreme Temperatures
Authors: Yu Bin , Wang Xiaolan L. , Feng Yang , Chan Rodney , Compo Gilbert P. , Slivinski Laura C. , Sardeshmukh Prashant D. , Wehner Michael , Yang Xiao-Yi
Published: July 2022

In this study, we detect and track extratropical cyclones using 6-hourly mean sea level pressure data taken from the Twentieth Century Reanalysis version 3 (20CRv3) over the period 1951–2015 and compare them with those in the Interim and fifth generation of ECMWF reanalyses over the period 1979–2018. Three indices were employed to characterize cyclone activity, including cyclone count, cyclone intensity, and a cyclone activity index (CAI) that combines the count and intensity. The results show that the cyclone indices in the three datasets have comparable annual climatologies and seasonal evolution over the northern extratropical land and ocean in recent decades. Based on the cyclone indices over the period 1951–2010 in 80 ensemble members of 20CRv3, cyclone count and intensity are negatively correlated in winter and tend to be positively and weakly correlated in summer. The interannual CAI variability is dominated by the cyclone count variability. Regional mean cyclone activity can be well represented using the ensemble average cyclone index. We then examined the linkage of the cyclone activity in 20CRv3 and observed cold and warm extremes over Eurasia and North America over the period 1951–2010. In winter, the principal components of interannual cold and warm extreme anomalies are more correlated with the regional mean cyclone count index over Eurasia, while they are more correlated with the cyclone intensity index over North America. The temperature anomalies associated with the regional and ensemble mean cyclone count index explain about 10% (20%) of interannual cold (warm) extreme variances averaged over Eurasia. The temperature anomalies associated with the mean cyclone intensity explain about 10% of interannual cold and warm extreme variances over North America. Large-scale atmospheric circulation anomalies in association with cyclone activity and the induced temperature advection drive temperature anomalies over Eurasia and North America. In summer, circulation and thermal advection anomalies associated with cyclone activity are weak over the two continents. Hence, that season’s relationship between cyclone activity and extreme temperature variability is weak.
Understanding the El Niño Southern Oscillation Effect on Cut-Off Lows as Simulated in Forced SST and Fully Coupled Experiments
Authors: Pinheiro Henri R. , Ambrizzi Tercio , Hodges Kevin I. , Gan Manoel A.
Published: July 2022

In this study, we show that changes in the 250 hPa vorticity cut-off low (COL) activity may possibly be driven by sea surface temperature (SST) variations in the tropical Pacific. Using ERA5 reanalysis, the existence of different large-scale circulation patterns is identified that work to enhance the COL activity with a weakened jet stream, while COLs are suppressed with strengthened westerlies. The present-day simulations of AMIP-CMIP6 models reproduce realistic features of the El Niño Southern Oscillation (ENSO)–COL teleconnection, but biases exist, especially in coupled models. The differences are a priori due to the inability of the models to accurately predict the time-mean zonal flow, which may be in part due to systematic biases in the predicted SST. The underestimation of warm SST anomalies over the eastern Pacific is a common problem in CMIP3 and CMIP5 models and remains a major uncertainty in CMIP6. We find that a reduced bias in the predicted SST by coupled models is most likely to produce more skillful simulations in the Southern Hemisphere, but the same evidence does not hold for the Northern Hemisphere. The study suggests the potential for seasonal prediction of COLs and the benefits that would result using accurate initialization and consistent model coupling.
A Social Vulnerability Index for Air Pollution and Its Spatially Varying Relationship to PM2.5 in Uganda
Authors: Clarke Kayan , Ash Kevin , Coker Eric S. , Sabo-Attwood Tara , Bainomugisha Engineer
Published: July 2022

Fine particulate matter (PM2.5) is a ubiquitous air pollutant that is harmful to human health. Social vulnerability indices (SVIs) are calculated to determine where vulnerable populations are located. We developed an SVI for Uganda to identify areas with high vulnerability and exposure to air pollution. The 2014 national census was used to create the SVI. Mean PM2.5 at the subcounty level was estimated using global PM2.5 estimates. The mean PM2.5 for Kampala at the parish level was estimated using low-cost PM2.5 sensors and spatial interpolation. A local indicator of spatial association (LISA) was performed to determine significant spatial clusters of social vulnerability, and a bivariate analysis was performed to identify where significant associations were between SVI and annual PM2.5 mean concentrations. The LISA results showed significant clustering of high SVI in the northern and western regions of the country. The spatial bivariate analysis showed positive linear associations between SVI and PM2.5 concentration in subcounties in the northern, western, and central regions of Uganda, as well as in certain northern parishes in Kampala. Our approach identified areas facing both high social vulnerability and air pollution levels. These areas can be prioritized for health interventions and policy to reduce the impact of ambient PM2.5.
Variation of Relative Humidity as Seen through Linking Water Vapor to Air Temperature: An Assessment of Interannual Variations in the Near-Surface Atmosphere
Authors: Hao Jiawei , Lu Er
Published: July 2022

It has generally been regarded that, in the warming climate, atmospheric water vapor may increase due to the enhancement in surface evaporation, which is expected from the Clausius–Clapeyron (C–C) equation, along with the assumption that relative humidity experiences small changes. If the variation in relative humidity is small, the response of water vapor to temperature will be closely in line with the C–C equation. However, whether relative humidity experiences large or small changes needs be assessed, and the change of relative humidity should be compared with the change in surface–air temperature. In this study, we link surface vapor pressure, which characterizes atmospheric water vapor, to surface-air temperature, and treat both the temperature and relative humidity as influencing factors. A method based on linear regression is applied to compare the interannual variabilities of relative humidity and temperature in the interannual variation in surface vapor pressure. Whether the year-to-year perturbation of relative humidity is important, compared with the perturbation in surface-air temperature, is explored Results show that, at high latitudes of both hemispheres, the variation in vapor pressure is dominated by air temperature, and relative humidity has small positive contributions. Thus, the variation in relative humidity over these regions is comparably small, and the response of water vapor to temperature can well follow the C–C equation. Differently, at mid-low latitudes, especially on land, air temperature plays a negative role in the variation in vapor pressure. Relative humidity offsets the negative contribution and dominates the variation in vapor pressure, suggesting that the variation in the relative humidity over these regions is comparably large. Hence, the response of water vapor to temperature deviate from the C–C equation. Analysis indicates that the different results of the dominance from the two influencing factors are affected by the dual effects of precipitation or wet-air transport over land. Both precipitation and the transport of cold wet air could break the C–C relation between water vapor pressure and temperature.
Local Structure of Convex Surfaces near Regular and Conical Points
Authors: Plakhov Alexander
Published: July 2022

Consider a point on a convex surface in Rd, d≥2 and a plane of support Π to the surface at this point. Draw a plane parallel with Π cutting a part of the surface. We study the limiting behavior of this part of the surface when the plane approaches the point, being always parallel with Π. More precisely, we study the limiting behavior of the normalized surface area measure in Sd−1 induced by this part of the surface. In this paper, we consider two cases: (a) when the point is regular and (b) when it is singular conical, that is the tangent cone at the point does not contain straight lines. In Case (a), the limit is the atom located at the outward normal vector to Π, and in Case (b), the limit is equal to the measure induced by the part of the tangent cone cut off by a plane.
2-Complex Symmetric Composition Operators on H2
Authors: Hu Lian , Li Songxiao , Yang Rong
Published: July 2022

In this paper, we study 2-complex symmetric composition operators with the conjugation J, defined by Jf(z)=(f(z¯))¯, on the Hardy space H2. More precisely, we obtain the necessary and sufficient condition for the composition operator Cϕ to be 2-complex symmetric with J when ϕ is an automorphism of D. We also characterize 2-complex symmetric with J when ϕ is a linear fractional self-map of D.
A Direct Interaction between Cyclodextrins and TASK Channels Decreases the Leak Current in Cerebellar Granule Neurons
Authors: Zúñiga Rafael , Mancilla Daniel , Rojas Tamara , Vergara Fernando , González Wendy , Catalán Marcelo A. , Zúñiga Leandro
Published: July 2022

Two pore domain potassium channels (K2P) are strongly expressed in the nervous system (CNS), where they play a central role in excitability. These channels give rise to background K+ currents, also known as IKSO (standing-outward potassium current). We detected the expression in primary cultured cerebellar granule neurons (CGNs) of TWIK-1 (K2P1), TASK-1 (K2P3), TASK-3 (K2P9), and TRESK (K2P18) channels by immunocytochemistry and their association with lipid rafts using the specific lipids raft markers flotillin-2 and caveolin-1. At the functional level, methyl-β-cyclodextrin (MβCD, 5 mM) reduced IKSO currents by ~40% in CGN cells. To dissect out this effect, we heterologously expressed the human TWIK-1, TASK-1, TASK-3, and TRESK channels in HEK-293 cells. MβCD directly blocked TASK-1 and TASK-3 channels and the covalently concatenated heterodimer TASK-1/TASK-3 currents. Conversely, MβCD did not affect TWIK-1- and TRESK-mediated K+ currents. On the other hand, the cholesterol-depleting agent filipin III did not affect TASK-1/TASK-3 channels. Together, the results suggest that neuronal background K+ channels are associated to lipid raft environments whilst the functional activity is independent of the cholesterol membrane organization.
Genistein Sensitizes Human Cholangiocarcinoma Cell Lines to Be Susceptible to Natural Killer Cells
Authors: Chiawpanit Chutipa , Panwong Suthida , Sawasdee Nunghathai , Yenchitsomanus Pa-thai , Panya Aussara
Published: July 2022

Cholangiocarcinoma (CCA) is a lethal bile duct cancer, which has poor treatment outcomes due to its high resistance to chemotherapy and cancer recurrence. Activation of aberrant anti-apoptotic signaling pathway has been reported to be a mechanism of chemoresistance and immune escape of CCA. Therefore, reversal of anti-apoptotic signaling pathway represents a feasible approach to potentiate effective treatments, especially for CCA with high chemoresistance. In this study, we demonstrated the effects of genistein on reactivation of apoptosis cascade and increase the susceptibility of CCA cells to natural killer (NK-92) cells. Genistein at 50 and 100 µM significantly activated extrinsic apoptotic pathway in CCA cells (KKU055, KKU100, and KKU213A), which was evident by reduction of procaspase-8 and -3 expression. Pretreatment of CCA cells with genistein at 50 µM, but not NK-92 cells, significantly increased NK-92 cell killing ability over the untreated control, suggesting the ability of genistein to sensitize CCA cells. Interestingly, genistein treatment could greatly lower the expression of cFLIP, an anti-apoptotic protein involved in the immune escape pathway, in addition to upregulation of death receptors, Fas- and TRAIL-receptors, in CCA cells, which might be the underlying molecular mechanism of genistein to sensitize CCA to be susceptible to NK-92 cells. Taken together, this finding revealed the benefit of genistein as a sensitizer to enhance the efficiency of NK cell immunotherapy for CCA.
A Metabolomic Approach and Traditional Physical Assessments to Compare U22 Soccer Players According to Their Competitive Level
Authors: da Cruz João Pedro , dos Santos Fábio Neves , Rasteiro Felipe Marroni , Marostegan Anita Brum , Manchado-Gobatto Fúlvia Barros , Gobatto Claudio Alexandre
Published: July 2022

The purpose of this study was to use traditional physical assessments combined with a metabolomic approach to compare the anthropometric, physical fitness level, and serum fasting metabolic profile among U22 soccer players at different competitive levels. In the experimental design, two teams of male U22 soccer were evaluated (non-elite = 20 athletes, competing in a regional division; elite = 16 athletes, competing in the first division of the national U22 youth league). Earlobe blood samples were collected, and metabolites were extracted after overnight fasting (12 h). Untargeted metabolomics through Liquid Chromatograph Mass Spectrometry (LC-MS) analysis and anthropometric evaluation were performed. Critical velocity was applied to determine aerobic (CV) and anaerobic (ARC) capacity. Height (non-elite = 174.4 ± 7.0 cm; elite = 176.5 ± 7.0 cm), body mass index (non-elite = 22.1 ± 2.4 kg/m2; elite = 21.9 ± 2.3 kg/m2), body mass (non-elite = 67.1 ± 8.8 kg; elite = 68.5 ± 10.1 kg), lean body mass (non-elite = 59.3 ± 7.1 kg; elite = 61.1 ± 7.9 kg), body fat (non-elite = 7.8 ± 2.4 kg; elite = 7.3 ± 2.4 kg), body fat percentage (non-elite = 11.4 ± 2.4%; elite = 10.5 ± 1.7%), hematocrit (non-elite = 50.2 ± 4.0%; elite = 51.0 ± 4.0%), CV (non-elite = 3.1 ± 0.4 m/s; elite = 3.0 ± 0.2 m/s), and ARC (non-elite = 129.6 ± 55.7 m; elite = 161.5 ± 61.0 m) showed no significant differences between the elite and non-elite teams, while the multivariate Partial Least Squares Discriminant Analysis (PLS-DA) model revealed a separation between the elite and non-elite athletes. Nineteen metabolites with importance for projection (VIP) >1.0 were annotated as belonging to the glycerolipid, sterol lipid, fatty acyl, flavonoid, and glycerophospholipid classes. Metabolites with a high relative abundance in the elite group were related in the literature to a better level of aerobic power, greater efficiency in the recovery process, and improvement of mood, immunity, decision making, and accuracy, in addition to acting in mitochondrial preservation and electron transport chain maintenance. In conclusion, although classical physical assessments were not able to distinguish the teams at different competitive levels, the metabolomics approach successfully indicated differences between the fasting metabolic profiles of elite and non-elite teams.
Spaghetti Tracer: A Framework for Tracing Semiregular Filamentous Densities in 3D Tomograms
Authors: Sazzed Salim , Scheible Peter , He Jing , Wriggers Willy
Published: July 2022

Within cells, cytoskeletal filaments are often arranged into loosely aligned bundles. These fibrous bundles are dense enough to exhibit a certain regularity and mean direction, however, their packing is not sufficient to impose a symmetry between—or specific shape on—individual filaments. This intermediate regularity is computationally difficult to handle because individual filaments have a certain directional freedom, however, the filament densities are not well segmented from each other (especially in the presence of noise, such as in cryo-electron tomography). In this paper, we develop a dynamic programming-based framework, Spaghetti Tracer, to characterizing the structural arrangement of filaments in the challenging 3D maps of subcellular components. Assuming that the tomogram can be rotated such that the filaments are oriented in a mean direction, the proposed framework first identifies local seed points for candidate filament segments, which are then grown from the seeds using a dynamic programming algorithm. We validate various algorithmic variations of our framework on simulated tomograms that closely mimic the noise and appearance of experimental maps. As we know the ground truth in the simulated tomograms, the statistical analysis consisting of precision, recall, and F1 scores allows us to optimize the performance of this new approach. We find that a bipyramidal accumulation scheme for path density is superior to straight-line accumulation. In addition, the multiplication of forward and backward path densities provides for an efficient filter that lifts the filament density above the noise level. Resulting from our tests is a robust method that can be expected to perform well (F1 scores 0.86–0.95) under experimental noise conditions.