bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential fluid mechanics – basis of the theory of flows with combustion
Authors: Chashechkin Yuli D.
Published: May 2021

The basis of invariant models is a system of fundamental equations with an empirical formula for the Gibbs potential and density. This paper presents an analysis of fast direct atomic-molecular, mechanical with a flow or wavy with a group velocity, and slow diffusion transfer of energy. The classification of components, including ligaments, waves, and vortices is given based on the compatibility condition, which determines the rank and the order of the linearized version of equations. The requirements for numerical and laboratory modeling are formulated. The structure of the flow near the strip and the rotating disk is studied. Comparison of calculations with the data of experiments carried out at the stands of the Unique science facilities “GFK IPMech RAS” is given. Expanding developed approaches to flows with combustion is discussed.
Finishing surface treatment of GTE parts with dry electropolishing
Authors: Krioni N.K. , Mingazhev A.D. , Gafarova V.A.
Published: May 2021

One of the major problems in GTE production is ensuring high performance of compressor blades. Existing methods of surface polishing have a number of disadvantages and, cannot ensure a high-quality surface of gas turbine engine blades. The most advanced method of polishing parts is the technology of dry electropolishing in the medium of granules (DEPG). However, the use of the DEPG method during polishing leads to defects. The study of the defect causes during DEPG allowed the authors of this paper to develop a brand new technology of dry tape electropolishing. This method made it possible to eliminate the disadvantages of DEPG and to ensure the specified geometric parameters of the blade airfoil.
Influence of operating conditions on the protective polyurethane coating for carbon fiber reinforced plastic blades of gas turbine engines
Authors: Orlov M A , Polikarpova I A , Storozhuk I P , Afanasiev D V , Solodilov V I , Kireinov A V , Shapagin A V
Published: May 2021

The article presents research results of protective coating, which is a two-component composition based on polyurethane, developed in Bauman Moscow State Technical University, in operating conditions. The influence of sea water and negative temperature on the properties of carbon fiber reinforced plastic with protective coatings, as well as resistance to erosion wear, was determined. It is shown that the developed coating has high performance properties and resistance to erosion wear compared to existing commercial coatings certified by Boeing, Pratt & Whitney and Airbus.
Dynamic loading of spur gears with linear tooth profile modification: modelling and experimental comparisons
Authors: Kalinin D V
Published: May 2021

A dynamic model of a gear pair has been developed to investigate methods of decreasing dynamic loads and analysing dynamic stresses of gears in aviation engine drives. The effect of tooth profile modification on dynamic stresses in the system, as well as the effect of main gear parameters is analysed. It is shown that high level of dynamic stresses and vibrations in gears may be caused by using standard parameters of tooth profile modification. An experimental study of the dynamics of gears with various profile modification parameters has been carried out. The paper shows the necessity of changing the approach to calculating parameters of tooth profile modification of teeth.
A study on the operation of a gas turbine unit using hydrogen as fuel
Authors: Marin G E , Mendeleev D I , Osipov B M
Published: May 2021

The last decade has been driven by the impact of environmental challenges on the energy industry. Decarburization policy is the driver of the global energy transition. Hydrogen can be used as an alternative to natural gas, kerosene, and diesel fuel. A large-scale conversion of generating equipment to hydrogen fuel would significantly reduce carbon impact on the world because the product of hydrogen combustion is water. This paper focuses on the combustion of pure hydrogen in a GE 6FA power gas turbine. A mathematical model has been created in the AS GRET software package. During the simulation, the operation of a gas turbine unit in the load range from 40 to 77 MW was considered. As a result, the dependences of fuel consumption, enthalpy, and air consumption depending on the load were obtained. The value of the heat of the exhaust gases was also obtained.
Developing a critical technologies roadmap for next generation hybrid and electric commuter airplanes
Authors: Sukharev A A , Ovdienko M A , Varyukhin A N , Zakharchenko V S , Galperin S B , Fomin A V
Published: May 2021

Using hybrid and electric propulsion systems (HPS and EPS) as part of commuter airplanes provides a wide range of opportunities for creating fundamentally new aircraft configurations. The main idea is that HPS and EPS allow for flexible aircraft energy redistribution. Therefore, the propulsion system’s efficiency increases, which leads to a decrease of its environmental impact and improves its economic performance. The main barrier to implementing new HPS and EPS commuter airplanes concepts is the inadequate level of technological advancements. This paper covers the review of promising concepts of propulsion systems, and provides the list and the required level of technical perfection for technologies necessary for future commuter airplanes.
Innovative Management of Design Concepts Research and International Cooperation on EU Programs for creating Hybrid Electric Aircraft & Airship
Authors: Ravikovich Yu , Ponyaev L , Klusachek M
Published: May 2021

Fast and expanded implementation of the most relevant innovative developments is becoming a fundamental trend in the strategy of breakthrough economic development of advanced countries. However, today finding and implementing any original idea or a new scientific discovery or technological solution requires more and more tool costs. It is necessary to use highly valuable experience of smart specialists and provide considerable financial support for foreign economic cooperation and targeted scientific interaction on an international level. MAI was included in two international consortiums for the new European programs INEA 2020-2023 to create new promising environmental models of Hybrid Electric Propulsion systems for FUTPRINT50 and IMOTHEP regional passenger aircraft projects.
Characterization of magnetic Czochralski silicon devices with aluminium oxide field insulator: effect of oxygen precursor on electrical properties and radiation hardness
Authors: Ott J. , Bharthuar S. , Gädda A. , Arsenovich T. , Bezak M. , Brücken E. , Golovleva M. , Härkönen J. , Kalliokoski M. , Karadzhinova-Ferrer A. , Kirschenmann S. , Litichevskyi V. , Luukka P. , Martikainen L. , Naaranoja T.
Published: May 2021

Aluminium oxide (Al2O3) has been proposed as an alternative to thermal silicon dioxide (SiO2) as field insulator and surface passivation for silicon detectors, where it could substitute p-stop/p-spray insulation implants between pixels due to its negative oxide charge, and enable capacitive coupling of segments by means of its higher dielectric constant.
Al2O3 is commonly grown by atomic layer deposition (ALD), which allows the deposition of thin layers with excellent precision.

In this work, we report the electrical characterization of single pad detectors (diodes) and MOS capacitors fabricated on magnetic Czochralski silicon substrates and using Al2O3 as field insulator. Devices are studied by capacitance-voltage, current-voltage, and transient current technique measurements. We evaluate the influence of the oxygen precursors in the ALD process, as well as the effect of gamma irradiation, on the properties of these devices. We observe that leakage currents in diodes before the onset of breakdown are low for all studied ALD processes. Charge collection as measured by transient current technique (TCT) is also independent of the choice of oxygen precursor. The Al2O3 films deposited with O3 possess a higher negative oxide charge than films deposited by H2O, However, in diodes a higher oxide charge is linked to earlier breakdown, as has been predicted by simulation studies. A combination of H2and O3 precursors results in a good compromise between the beneficial properties provided by the respective individual precursors.
Controllable performance of a dopamine-modified silk fibroin-based bio-adhesive by doping metal ions
Authors: Yin Zichu , Liu Han , Lin Minjie , Xie Wenjiao , Yang Xiaogang , Cai Yurong
Published: May 2021

Bio-adhesives are essential for wound healing because of their convenience and safety. Although widely used as biomaterials, silk fibroin’s (SF’s) further application as bio-adhesive is hindered due to its weak stickiness with tissue and slow gelation speed. Here, a dopamine-modified SF-based bio-adhesive is fabricated by using genipin as the chemical cross-linking agent. Furthermore, metal ions have been used to adjust the adhesion property of the bio-adhesive. The experimental results shows that the dopamine-modified SF-based composite holds a better stickiness except slow gelation speed. The doping of Cu2+ and Fe3+ can accelerate the gelation of the bio-adhesive. Compared with Cu2+, Fe3+ has a stronger effect on the gelation speed of the bio-adhesive, which is positive correlative to the concentration of Fe3+. The adhesive has injectability and degradability. In addition, the SF-based adhesive has good biocompatibility and good improvement for cell migration in vitro. The SF-based bio-adhesive holds potential application in the field of rapid fixation of wounds.
Estimation of winter soil cover by vegetation before spring-sown crops for mainland France using multispectral satellite imagery
Authors: Nowak Benjamin , Marliac Gaëlle , Michaud Audrey
Published: May 2021

Winter soil cover by vegetation is associated with multiple benefits. In this study, winter soil cover rate before spring-sown crops was estimated for mainland France from multispectral imagery. For 67% and 84% of the area under spring-sown crops for years 2018 and 2019, soil cover during the previous winter was estimated through the computation of the Normalized Difference Vegetation Index (NDVI), using Sentinel-2 multispectral images. At country scale, winter soil cover rate before spring-sown crops was estimated between 37% and 48% for 2018 and between 31% and 43% for 2019, depending on the NDVI threshold for a soil to be considered covered by at least 50% of vegetation. Spatial patterns were relatively similar between the two years studied, highlighting strong heterogeneities between French departments. Cropping systems may explain some of these heterogeneities, as it has been shown that there is a large variability in the soil cover rate between spring-sown crops, but also depending on the previous crop. Winter soil cover rate was higher for crops associated with livestock production, such as maize silage (between 59% and 74% of plots covered before this crop). It was also shown that winter soil cover could be ensured by other means than cover crops: temporary grasslands were the previous crop with the highest soil cover, probably due to late ploughing. For these reasons, mixed systems combining livestock and crop productions may be a solution to increase winter soil cover before spring-sown crops.
Mating Communication of the Variegated Leafhopper, Erasmoneura variabilis, With Notes on Vibrational Signaling of Other Grapevine Cicadellids in California
Authors: Krugner Rodrigo , Gordon Shira D
Published: May 2021

Leafhoppers in the tribe Erythroneurini are a concern for grape growers in California due to direct feeding damage by piercing the leaves. Management of leafhopper populations in vineyards may be accomplished by insecticide applications, the release of natural enemies, conservation biological control, exploitation of controlled deficit irrigation, or a combination of the above. Based on research on other leafhopper species, a behavioral mating disruption is a viable option, but nothing is known about the mating communication and circadian signaling of these species in vineyards. The objectives of this study were to identify and describe vibrational signals associated with mate selection behavior of Erasmoneura variabilis and Erythroneura ziczac, and evaluate the occurrence of vibrational signals within sympatric populations of E. variabilis, E. ziczac, and Homalodisca vitripennis on grapevines. Analysis of vibrational communication signals revealed that 1) one female signal and two distinct male signals are used in E. variabilis pair formation, 2) the pair formation process in E. variabilis is divided into three communication phases, 3) E. variabilis pre-copulatory communication is longer in the presence than in the absence of male-male rivalry, 4) two distinct signals are used in E. ziczac pair formation, and 5) E. variabilis, E. ziczac, and H. vitripennis sing at night and during the day. Results include detailed descriptions of leafhopper communication signals that are relevant for future development of vibrational disruption as a novel method to suppress populations under field conditions.
Microbial Etiologies and Clinical Characteristics of Children Seeking Emergency Department Care Due to Vomiting in the Absence of Diarrhea
Authors: Freedman Stephen B , Xie Jianling , Lee Bonita E , Ali Samina , Pang Xiao-Li , Chui Linda , Zhuo Ran , Vanderkooi Otto G , Tellier Raymond , Funk Anna L , Tarr Phillip I
Published: May 2021

Background

As children with isolated vomiting are rarely able to provide a specimen suitable for routine pathogen testing, we have limited knowledge about their infecting pathogens.

Methods

Between December 2014 and August 2018, children <18 years old with presumed acute gastroenteritis who presented to 2 emergency departments (EDs) in Alberta, Canada, were recruited. Eligible participants had ≥3 episodes of vomiting and/or diarrhea in a 24-hour period, <7 days of symptoms, and provided a rectal swab or stool specimen. We quantified the proportion of children with isolated vomiting in whom an enteropathogen was identified, and analyzed clinical characteristics, types of enteropathogens, resources used, and alternative diagnoses.

Results

Of the 2695 participants, at the ED visit, 295 (10.9%), 1321 (49.0%), and 1079 (40.0%) reported having isolated diarrhea, vomiting and diarrhea, or isolated vomiting, respectively. An enteropathogen was detected most commonly in those with vomiting and diarrhea (1067/1321; 80.8%); detection did not differ between those with isolated diarrhea (170/295; 57.6%) and isolated vomiting (589/1079; 54.6%) (95% confidence interval of the difference: −3.4%, 9.3%). Children with isolated vomiting most often had a virus (557/1077; 51.7%), most commonly norovirus (321/1077; 29.8%); 5.7% (62/1079) had a bacterial pathogen. X-rays, ultrasounds, and urine tests were most commonly performed in children with isolated vomiting. Alternate etiologies were most common in those with isolated vomiting (5.7%; 61/1079).

Conclusions

The rate of enteropathogen identification in children with isolated vomiting using molecular diagnostic tests and rectal swabs is substantial. Molecular diagnostics offer an emerging diagnostic strategy in children with isolated vomiting.
Social Communication across Reproductive Boundaries: Hormones and the Auditory Periphery of Songbirds and Frogs
Authors: Gall Megan D , Baugh Alexander T , Lucas Jeffrey R , Bee Mark A
Published: May 2021

Synopsis

Most animals experience reproductive transitions in their lives; for example, reaching reproductive maturity or cycling in and out of breeding condition. Some reproductive transitions are abrupt, while others are more gradual. In most cases, changes in communication between the sexes follow the time course of these reproductive transitions and are typically thought to be coordinated by steroid hormones. We know a great deal about hormonal control of communication behaviors in birds and frogs, as well as the central neural control of these behaviors. There has also been significant interest in the effects of steroid hormones on central nervous system structures that control both the production and reception of communication signals associated with reproductive behaviors. However, peripheral sensory structures have typically received less attention, although there has been growing interest in recent years. It is becoming clear that peripheral sensory systems play an important role in reproductive communication, are plastic across reproductive conditions, and, in some cases, this plasticity may be mediated by steroid hormones. In this article, we discuss recent evidence for the role of peripheral auditory structures in reproductive communication in birds and frogs, the plasticity of the peripheral auditory system, and the role of steroid hormones in mediating the effects of the peripheral auditory system on reproductive communication. We focus on both seasonal and acute reproductive transitions, introduce new data on the role of hormones in modulating seasonal patterns, and make recommendations for future work.
Mustafin Models of Projective Varieties and Vector Bundles
Authors: Hahn Marvin Anas
Published: May 2021

Mustafin varieties are well-studied degenerations of projective spaces induced by a choice of integral points in a Bruhat–Tits building. In recent work, Annette Werner and the author initiated the study of degenerations of plane curves obtained by Mustafin varieties by means of arithmetic geometry. Moreover, we applied these techniques to construct models of vector bundles on plane curves with strongly semistable reduction. In this work, we take a Groebner basis approach to the more general problem of studying degenerations of projective varieties. Our methods include determining the behaviour of Groebner bases under substitution over unique factorisation rings. Finally, we outline applications to the $p-$adic Simpson correspondence, when the respective projective variety is a curve.
Multiomics reveal pivotal roles of sodium translocation and compartmentation in regulating salinity resistance in allotetraploid rapeseed
Authors: Zhou Ting , Yue Cai-Peng , Liu Ying , Zhang Tian-Yu , Huang Jin-Yong , Hua Ying-Peng
Published: May 2021

The large size and complexity of the allotetraploid rapeseed (Brassica napus) genome present huge challenges for understanding salinity resistance in this important crop. In this study, we identified two rapeseed genotypes with significantly different degrees of salinity resistance and examined the underlying mechanisms using an integrated analysis of phenomics, ionomics, genomics, and transcriptomics. Under salinity, a higher accumulation of osmoregulation substances and better root-system architecture was observed in the resistant genotype, H159, than in the sensitive one, L339. A lower shoot Na+ concentration and a higher root vacuolar Na+ concentration indicated lower root-to-shoot translocation and higher compartmentation in H159 than in L339. Whole-genome re-sequencing (WGRS) and transcriptome sequencing identified numerous DNA variants and differentially expressed genes involved in abiotic stress responses and ion transport. Combining ionomics with transcriptomics identified plasma membrane-localized BnaC2.HKT1;1 and tonoplast-localized BnaC5.NHX2 as the central factors regulating differential root xylem unloading and vacuolar sequestration of Na+ between the two genotypes. Identification of polymorphisms by WGRS and PCR revealed two polymorphic MYB-binding sites in the promoter regions that might determine the differential gene expression of BnaC2.HKT1;1 and BnaC5.NHX2. Our multiomics approach thus identified core transporters involved in Na+ translocation and compartmentation that regulate salinity resistance in rapeseed. Our results may provide elite gene resources for the improvement of salinity resistance in this crop, and our multiomics approach can be applied to other similar studies.
‘Somewhat of an affectation’: Bach, Vivaldi, and the Early Films of Pier Paolo Pasolini
Authors: Greig Donald
Published: May 2021

Critics and film theorists have frequently drawn attention to the use of J. S. Bach’s music in Accattone (1961), Pier Paolo Pasolini’s first film. Many have noted the strangeness of the musical choice and in particular its sociocultural disconnection from the film’s setting of the borgate, the deprived areas on the outskirts of Rome. Pasolini’s second film, Mamma Roma (1962), similarly focuses on the lives of an underclass of pimps, prostitutes, and scroungers, yet its use of the music of Antonio Vivaldi has elicited little study. This article explores the imbalance of critical responses in the context of Pasolini’s political aesthetic. I argue that the imposing figure of Bach has distracted commentators, and that Pasolini is less interested in the cultural associations of individual composers and compositions than in the formal properties of Baroque music. Close analysis of the films reveals careful correspondences between film and music that show both the potential and the limitations of Baroque music when applied to the moving image.
Hierarchically modelling Kepler dwarfs and subgiants to improve inference of stellar properties with asteroseismology
Authors: Lyttle Alexander J , Davies Guy R , Li Tanda , Carboneau Lindsey M , Leung Ho-Hin , Westwood Harry , Chaplin William J , Hall Oliver J , Huber Daniel , Nielsen Martin B , Basu Sarbani , García Rafael A
Published: May 2021

With recent advances in modelling stars using high-precision asteroseismology, the systematic effects associated with our assumptions of stellar helium abundance (Y) and the mixing-length theory parameter (αMLT) are becoming more important. We apply a new method to improve the inference of stellar parameters for a sample of Kepler dwarfs and subgiants across a narrow mass range ($0.8 \lt M \lt 1.2\, \rm M_\odot$). In this method, we include a statistical treatment of Y and the αMLT. We develop a hierarchical Bayesian model to encode information about the distribution of Y and αMLT in the population, fitting a linear helium enrichment law including an intrinsic spread around this relation and normal distribution in αMLT. We test various levels of pooling parameters, with and without solar data as a calibrator. When including the Sun as a star, we find the gradient for the enrichment law, $\Delta Y / \Delta Z = 1.05\substack{+0.28\\-0.25}$ and the mean αMLT in the population, $\mu _\alpha = 1.90\substack{+0.10\\-0.09}$. While accounting for the uncertainty in Y and αMLT, we are still able to report statistical uncertainties of 2.5 per cent in mass, 1.2 per cent in radius, and 12 per cent in age. Our method can also be applied to larger samples that will lead to improved constraints on both the population level inference and the star-by-star fundamental parameters.
Progenitor mass constraints for the type Ib intermediate-luminosity SN 2015ap and the highly extinguished SN 2016bau
Authors: Aryan Amar , Pandey S B , Zheng WeiKang , Filippenko Alexei V , Vinko Jozsef , Ouchi Ryoma , Shivvers Isaac , Yuk Heechan , Kumar Sahana , Stegman Samantha , Halevi Goni , Ross Timothy W , Gould Carolina , Yunus Sameen , Baer-Way Raphael , deGraw Asia , Maeda Keiichi , Bhattacharya D , Kumar Amit , Gupta Rahul , Yadav Abhay P , Buckley David A H , Misra Kuntal , Tiwari S N
Published: May 2021

Photometric and spectroscopic analyses of the intermediate-luminosity Type Ib supernova (SN) 2015ap and of the heavily reddened Type Ib SN 2016bau are discussed. Photometric properties of the two SNe, such as colour evolution, bolometric luminosity, photospheric radius, temperature, and velocity evolution, are also constrained. The ejecta mass, synthesized nickel mass, and kinetic energy of the ejecta are calculated from their light-curve analysis. We also model and compare the spectra of SN 2015ap and SN 2016bau at various stages of their evolution. The P Cygni profiles of various lines present in the spectra are used to determine the velocity evolution of the ejecta. To account for the observed photometric and spectroscopic properties of the two SNe, we have computed 12 M⊙ zero-age main-sequence (ZAMS) star models and evolved them until the onset of core-collapse using the publicly available stellar-evolution codeMESA. Synthetic explosions were produced using the public version of STELLA and another publicly available code, SNEC, utilizing the MESA models. SNEC and stella provide various observable properties such as the bolometric luminosity and velocity evolution. The parameters produced by SNEC/STELLA and our observations show close agreement with each other, thus supporting a 12 M⊙ ZAMS star as the possible progenitor for SN 2015ap, while the progenitor of SN 2016bau is slightly less massive, being close to the boundary between SN and non-SN as the final product.
DNA damage in leukocytes and serum nitrite concentration are negatively associated in type 1 diabetes
Authors: Rostoka Evita , Salna Ilze , Dekante Alise , Pahirko Leonora , Borisovs Vitalijs , Celma Laura , Valeinis Jānis , Sjakste Nikolajs , Sokolovska Jelizaveta
Published: May 2021

Chronic hyperglycaemia leads to DNA damage in diabetes and might be associated with nitrosative stress. In this study, we aimed at assessing the level of DNA strand breaks in leukocytes, serum nitrite and nitrate in patients with type 1 diabetes and healthy controls and associations of these parameters with diabetes-related outcomes in a prospective study. The level of DNA damage was determined in 71 patients with type 1 diabetes and 57 healthy controls by comet assay and scored with arbitrary units (AU). The chemiluminescence method was used to measure nitrite and nitrate. Clinical information and data on consumption of alcohol, physical activity and smoking were collected. Progression of complications in patients with diabetes was assessed after a follow-up time of 4–5 years. We observed a higher level of DNA damage in leukocytes of patients with type 1 diabetes compared with healthy subjects [type 1 diabetes AU 50 (36–74.5); control AU 30 (24.1–43), P < 0.001]. According to regression, type 1 diabetes leads to a 2-fold increase in DNA damage. In the group of type 1 diabetes, DNA damage correlated positively with total cholesterol (R = 0.262, P = 0.028) and negatively with serum glucose level (R = −0.284; P = 0.018) and serum nitrite (R = −0.335; P = 0.008). DNA damage was not significantly associated with HbA1c, diabetes duration, complications and lifestyle factors. However, DNA damage > 57 AU was associated with statistically significantly lower serum nitrite and 1.52 higher risk of progression of complications of diabetes over the follow-up period. The latter result was not statistically significant due to insufficient study power [relative risk 1.52 (95% confidence interval = 0.68, 3.42, P = 0.31)]. Our results confirm that type 1 diabetes is associated with a higher level of DNA strand breaks in leukocytes when compared with the reference group and demonstrate the negative association between DNA damage and serum nitrite concentration.
Quantitative Characterization of Population-Wide Tissue- and Metabolite-Specific Variability in Perchloroethylene Toxicokinetics in Male Mice
Authors: Dalaijamts Chimeddulam , Cichocki Joseph A , Luo Yu-Syuan , Rusyn Ivan , Chiu Weihsueh A
Published: May 2021

Quantification of interindividual variability is a continuing challenge in risk assessment, particularly for compounds with complex metabolism and multi-organ toxicity. Toxicokinetic variability for perchloroethylene (perc) was previously characterized across 3 mouse strains and in 1 mouse strain with various degrees of liver steatosis. To further characterize the role of genetic variability in toxicokinetics of perc, we applied Bayesian population physiologically based pharmacokinetic (PBPK) modeling to the data on perc and metabolites in blood/plasma and tissues of male mice from 45 inbred strains from the Collaborative Cross (CC) mouse population. After identifying the most influential PBPK parameters based on global sensitivity analysis, we fit the model with a hierarchical Bayesian population analysis using Markov chain Monte Carlo simulation. We found that the data from 3 commonly used strains were not representative of the full range of variability in perc and metabolite blood/plasma and tissue concentrations across the CC population. Using interstrain variability as a surrogate for human interindividual variability, we calculated dose-dependent, chemical-, and tissue-specific toxicokinetic variability factors (TKVFs) as candidate science-based replacements for the default uncertainty factor for human toxicokinetic variability of 100.5. We found that toxicokinetic variability factors for glutathione conjugation metabolites of perc showed the greatest variability, often exceeding the default, whereas those for oxidative metabolites and perc itself were generally less than the default. Overall, we demonstrate how a combination of a population-based mouse model such as the CC with Bayesian population PBPK modeling can reduce uncertainty in human toxicokinetic variability and increase accuracy and precision in quantitative risk assessment.
Genetic Dissection of T-DNA Insertional Mutants Reveals Uncoupling of Dikaryotic Filamentation and Virulence in Sugarcane Smut Fungus
Authors: Lu Shan , Guo Feng , Wang Zhiqiang , Shen Xiaorui , Deng Yizhen , Meng Jiaorong , Jiang Zide , Chen Baoshan
Published: May 2021

The biotrophic basidiomycetous fungus Sporisorium scitamineum causing smut disease in sugarcane is characterized by a life cycle composed of a yeast-like nonpathogenic haploid basidiosporial stage outside the plant and filamentous pathogenic dikaryotic hyphae within the plant. Under field conditions, dikaryotic hyphae are formed after mating of two opposite mating-type strains. However, the mechanisms underlying genetic regulation of filamentation and its association with pathogenicity and development of teliospores are unclear. This study has focused on the characterization and genetic dissection of haploid filamentous mutants derived from T-DNA insertional mutagenesis. Our results support the existence of at least three genotypes among the six haploid filamentous mutants that differentially contribute to virulence and development of the whip and teliospore, providing a novel foundation for further investigation of the regulatory networks associated with pathogenicity and teliospore development in S. scitamineum.
The Quality of Life of Patients with Colorectal Cancer and a Stoma in China: A Quantitative Cross-sectional Study
Authors: Liu Huayun , Zhu Xiaomei , Yu Juping , He Pingping , Shen Boyong , Tang Xinhui , Xu Xianghua , Wei Di , Chen Yongyi , Li Xuying
Published: May 2021

OBJECTIVE

To explore quality of life (QOL) in patients with colorectal cancer and a stoma and factors associated with their QOL.

METHODS

A quantitative cross-sectional study was carried out in the stoma and wound care clinic of a cancer hospital in China. Participants were recruited from clinic patients. Investigators collected demographic data and clinical information; QOL was measured using a Chinese version of the stoma-QOL scale.

RESULTS

In total, 359 participants took part; 161 (44.8%) had an ileostomy, whereas the others had a colostomy, and about half of the participants (46.5%) had a permanent stoma. The mean age was 57.86 ± 11.92 years. The QOL scores of most participants were poor, with a median value of 49.44. Participants whose stoma was cared for by others had a significantly lower QOL score than those who cared for their own stomas (odds ratio [OR], 1.58; 95% confidence interval [CI], 1.05–2.38; P = .029). Participants with a temporary stoma had a lower QOL score than those with a permanent stoma (OR, 2.08; 95% CI, 1.275–3.40; P = .004). Further, participants with a complication had a lower QOL score than those without (OR, 1.62; 95% CI, 1.07–2.43; P = .022).

CONCLUSIONS

These findings suggest a need for well-developed interventions to improve the QOL of these patients. This study provides valuable insights to inform the development of future clinical practice and research in this area in China and beyond.
Understanding VA’s Use of and Relationships With Community Care Providers Under the MISSION Act
Authors: Mattocks Kristin M. , Kroll-Desrosiers Aimee , Kinney Rebecca , Elwy Anashua R. , Cunningham Kristin J. , Mengeling Michelle A.
Published: May 2021

Background:

Congress has enacted 2 major pieces of legislation to improve access to care for Veterans within the Department of Veterans Affairs (VA). As a result, the VA has undergone a major transformation in the way that care is delivered to Veterans with an increased reliance on community-based provider networks. No studies have examined the relationship between VA and contracted community providers. This study examines VA facility directors’ perspectives on their successes and challenges building relationships with community providers within the VA Community Care Network (CCN).

Objectives:

To understand who VA facilities partner with for community care, highlight areas of greatest need for partnerships in various regions, and identify challenges of working with community providers in the new CCN contract.

Research Design:

We conducted a national survey with VA facility directors to explore needs, challenges, and expectations with the CCN.

Results:

The most common care referred to community providers included physical therapy, chiropractic, orthopedic, ophthalmology, and acupuncture. Open-ended responses focused on 3 topics: (1) Challenges in working with community providers, (2) Strategies to maintain strong relationships with community providers, and (3) Re-engagement with community providers who no longer provide care for Veterans.

Conclusions:

VA faces challenges engaging with community providers given problems with timely reimbursement of community providers, low (Medicare) reimbursement rates, and confusing VA rules related to prior authorizations and bundled services. It will be critical to identify strategies to successfully initiate and sustain relationships with community providers.
Rural Veterans’ Experiences With Outpatient Care in the Veterans Health Administration Versus Community Care
Authors: Davila Heather , Rosen Amy K. , Beilstein-Wedel Erin , Shwartz Michael , Chatelain Leslie , Gurewich Deborah
Published: May 2021

Background:

The 2014 Veterans Access, Choice and Accountability Act was intended to improve Veterans’ access to timely health care by expanding their options to receive community care (CC) paid for by the Veterans Health Administration (VA). Although CC could particularly benefit rural Veterans, we know little about rural Veterans’ experiences with CC.

Objective:

The objective of this study was to compare rural Veterans’ experiences with CC and VA outpatient health care services to those of urban Veterans and examine changes over time.

Research Design:

Retrospective, cross-sectional study using data from the Survey of Healthcare Experiences of Patients (SHEP) and VA Corporate Data Warehouse. Subjects: All Veterans who responded to the SHEP survey in Fiscal Year (FY) 16 or FY19.

Measures:

Outcomes were 4 measures of care experience (Access, Communication, Coordination, and Provider Rating). Independent variables included care setting (CC/VA), rural/urban status, and demographic and clinical characteristics.

Results:

Compared with urban Veterans, rural Veterans rated CC the same (for specialty care) or better (for primary care). Rural Veterans reported worse experiences in CC versus VA, except for specialty care Access. Rural Veterans’ care experiences improved between FY16 and FY19 in both CC and VA, with greater improvements in CC.

Conclusions:

Rural Veterans’ reported comparable or better experiences in CC compared with urban Veterans, but rural Veterans’ CC experiences still lagged behind their experiences in VA for primary care. As growing numbers of Veterans use CC, VA should ensure that rural and urban Veterans’ experiences with CC are at least comparable to their experiences with VA care.
Extreme growth plasticity in the early branching sauropodomorphMassospondylus carinatus
Authors: Chapelle Kimberley E. J. , Botha Jennifer , Choiniere Jonah N.
Published: May 2021

There is growing evidence of developmental plasticity in early branching dinosaurs and their outgroups. This is reflected in disparate patterns of morphological and histological change during ontogeny. In fossils, only the osteohistological assessment of annual lines of arrested growth (LAGs) can reveal the pace of skeletal growth. Some later branching non-bird dinosaur species appear to have followed an asymptotic growth pattern, with declining growth rates at increasing ontogenetic ages. By contrast, the early branching sauropodomorphPlateosaurus trossingensisappears to have had plastic growth, suggesting that this was the plesiomorphic condition for dinosaurs. The South African sauropodomorphMassospondylus carinatusis an ideal taxon in which to test this because it is known from a comprehensive ontogenetic series, it has recently been stratigraphically and taxonomically revised, and it lived at a time of ecosystem upheaval following the end-Triassic extinction. Here, we report on the results of a femoral osteohistological study ofM. carinatuscomprising 20 individuals ranging from embryo to skeletally mature. We find major variability in the spacing of the LAGs and infer disparate body masses forM. carinatusindividuals at given ontogenetic ages, contradicting previous studies. These findings are consistent with a high degree of growth plasticity inM. carinatus.
Is a fair comparison between doping tested and doping untested powerlifters possible?
Authors: Khudayarov Anna
Published: May 2021

Purpose

Powerlifting is clearly divided into doping tested amateur competitions and doping untested pro competitions with pro competition money prizes ranging from a few thousand USD to over $120 000 USD in a single competition. However, the results of both pro and amateur powerlifting competitions are then collected and put into the same result database (although there is the possibility to filter the results using doping control status). The powerlifting results are compared by scores to have a fair comparison between different weight class athletes. This study plays with the thought of comparing doping tested and doping untested athletes, and creates a coefficient for the comparison.

Methods

The powerlifting results (noted in kg) of the 10 top ranked athletes per weight class and separately for men and women, and for doping tested and doping untested categories were collected from the openpowerlifting.org database. A weight adjusted model was fit to these results separately for men and women with the doping control status used a binary factor.

Results

Doping control status was a significant factor when modelling the powerlifting results, p<0.001 for both men and women. Men’s doping untested results were 1.0725 times as large as the doping tested results. Women’s doping untested results were 1.1208 times as large as the doping tested results. These separate and precise factors could be used as coefficients for scoring doping tested and doping untested athletes’ powerlifting results. Moreover, the coefficients approximate the effect of doping on an elite level athlete’s results.
Technology-delivered undergraduate medical education involving patients and carers: A rapid systematic review
Authors: Lawes-Wickwar Sadie , Lovat Eitan , Alao Adedoyin , Hamer-Hunt Julia , Yurtoglu Nesrin , Jensen Cherise , Clarke Nicola , Roberts Nia , Park Sophie
Published: May 2021

Background

Involving patients and carers in medical education centralises their voice in healthcare and supports students to develop key professional and person-centred skills. Medical schools are increasingly using technology to deliver educational activities. No review currently exists to establish the variety of technologies and their uses in undergraduate medical education when patients and/or carers are involved.

Methods

Ovid MEDLINE, Ovid EMBASE and medRxiv were searched in October 2020 and reference lists of key articles were hand searched. Eligible studies reported technology-assisted education, in any setting, involving authentic patients and/or carers. Studies in foreign languages, or describing actors or non-authentic patients were excluded. Study quality was assessed using the Mixed Methods Appraisal Tool (MMAT). Levels of patient involvement were assessed using Towle et al’s (2010) taxonomy.

Results

Twenty studies were included. The majority involved patients and/or carers via pre-recorded videos or online scenarios, with no student-interaction. Four studies evaluated remote consultations using telehealth technology, involving real-time interactions with authentic patients. Technology-supported teaching sessions involving patients and/or carers were found to be acceptable to students, educationally valuable (to students and educators), and enhanced student engagement, patient-centred attitudes, knowledge of specific patient groups, and communication and clinical skills. Two studies describing real-time remote interactions with authentic patients indicated potential barriers for students (reduced ability to build relationship with patients and examine them), educators (reduced ability to build rapport with students) and patients (issues with using or accessing telehealth).

Conclusions

No studies directly measured the perspective of patients or carers involved in technology-delivered medical education. Future research should establish barriers and facilitators to patients and carers taking up a role in medical students’ education when technology is used, and evaluate PPI activities at Levels 3 and above as described by Towle et al’s taxonomy.
Heart rate changes associated with autonomic dysreflexia in daily life of individuals with chronic spinal cord injury
Authors: Yee Belinda , Nightingale Tom E. , Ramirez Andrea L. , Walter Matthias , Krassioukov Andrei V.
Published: May 2021

Objective

To characterize heart rate (HR) changes during autonomic dysreflexia (AD) in daily life for individuals with chronic spinal cord injury (SCI).

Design

Data analysis of two prospective clinical studies and one cross-sectional study.

Setting

Single-center study.

Participants

Forty-five individuals (including 8 females) with a chronic SCI at or above the sixth thoracic spinal segment with confirmed AD, and a median age and time since injury of 43 years (interquartile range [IQR] 36 – 50) and 17 years (IQR 6 – 23) respectively, were included for analysis.

Interventions

Not applicable.

Main outcome measure

Any systolic blood pressure (SBP) increase ≥ 20mmHg from baseline from a 24-hour ambulatory surveillance period was identified and categorized as either confirmed (i.e. known AD trigger), unknown (i.e. no diary entry), and unlikely (i.e. potential physical activity driven SBP increase). SBP-associated HR changes were categorized as either unchanged, increased or decreased compared to baseline.

Results

A total of 797 episodes of SBP increase above AD threshold were identified and classified as confirmed (n = 250, 31.4%), unknown (n = 472, 59.2%) or unlikely (n = 75, 9.4%). Median SBP changes and median SBP-related HR changes were 37 mmHg and -8 bpm, 28 mmHg and -6 bpm, or 30 mmHg and -4 bpm for confirmed, unknown, or unlikely episodes, respectively. HR-decrease/increase ratio was 3:1 for confirmed and unknown, and 1.5:1 for unlikely episodes. HR changes resulting in brady-/tachycardia were 34.4% / 2.8% for confirmed, 39.6% / 3.4% unknown, and 26.7% / 9.3% for unlikely episodes, respectively.

Conclusions

Our findings suggest that the majority of confirmed AD episodes are associated with a HR decrease. Further improvements, such as more precise participant diaries combined with the use of 24-hour Holter electrocardiogram and wearable-sensors-derived measures of physical activity could provide a better, more detailed characterization of HR changes during episodes of AD.
Prevalence and source analysis of COVID-19 misinformation of 138 countries
Authors: Al-Zaman Md. Sayeed
Published: May 2021

This study analyzed 9,657 pieces of misinformation that originated in 138 countries and fact-checked by 94 organizations. Collected from Poynter Institute’s official website and following a quantitative content analysis method along with descriptive statistical analysis, this research produces some novel insights regarding COVID-19 misinformation. The findings show that India (15.94%), the US (9.74%), Brazil (8.57%), and Spain (8.03%) are the four most misinformation-affected countries. Based on the results, it is presumed that the prevalence of COVID-19 misinformation can have a positive association with the COVID-19 situation. Social media (84.94%) produces the highest amount of misinformation, and the internet (90.5%) as a whole is responsible for most of the COVID-19 misinformation. Moreover, Facebook alone produces 66.87% misinformation among all social media platforms. Of all countries, India (18.07%) produced the highest amount of social media misinformation, perhaps thanks to the country’s higher internet penetration rate, increasing social media consumption, and users’ lack of internet literacy. On the other hand, countries like Turkey, the US, Brazil, and the Philippines where either political control over media is intense or political conservatism is apparent, experienced a higher amount of misinformation from mainstream media, political figures, and celebrities. Although the prevalence of misinformation was the highest in March 2020, given the present trends, it may likely to increase slightly in 2021.
Insights into genetic factors contributing to variability in SARS-CoV-2 susceptibility and COVID-19 disease severity
Authors: D’Antonio Matteo ,   The COVID-19 Host Genetics Initiative, Arthur Timothy D. , Nguyen Jennifer P. , Matsui Hiroko , D’Antonio-Chronowska Agnieszka , Frazer Kelly A.
Published: May 2021

Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we applied colocalization to compare summary statistics for 16 GWASs from the COVID-19 Host Genetics Initiative to investigate similarities and differences in their genetic signals. We identified 9 loci associated with susceptibility (one with two independent GWAS signals; one with an ethnicity-specific signal), 14 associated with severity (one with two independent GWAS signals; two with ethnicity-specific signals) and one harboring two discrepant GWAS signals (one for susceptibility; one for severity). Utilizing colocalization we also identified 45 GTEx tissues that had eQTL(s) for 18 genes strongly associated with GWAS signals in eleven loci (1-4 genes per locus). Some of these genes showed tissue-specific altered expression and others showed altered expression in up to 41 different tissue types. Our study provides insights into the complex molecular mechanisms underlying inherited predispositions to COVID-19-disease phenotypes.