bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of mechanical ball grinding time on the properties and microstructure of graphite-copper composite
Authors: Zou Haiping , Yu Xiaohong , Wu Hongliang
Published: January 2021

In this paper, the graphite-copper composite was prepared by powder metallurgy sintering method which used copper powder and graphene powder as raw materials. The powders were mixed by ultrasonic dispersion and mechanical ball grinding method. The effect of mechanical ball grinding time on the properties and microstructure of graphite-copper composite was investigated using Optical microscope, scanning electron microscope (SEM) and Vickers hardness meter. The result showed that the distribution of graphite in the copper matrix was uniformly and formed a good interface by using the ultrasonic dispersion and mechanical ball grinding method. When the mechanical ball grinding time was raised from 2 hours to 16 hours, the relative density and Vickers hardness of the graphite-copper composite reached their maximum value, the relative density was 92.1%, the Vickers hardness (HV0.5) was 61.9HV. However, the properties of graphite-copper composite showed a downward or stabilize trend the mechanical ball grinding time increasing from 16 hours to 48 hours.
A non-destructive testing method for metal stress based on conductivity measurement
Authors: Lu Qi , Wang Li , Gao Xiang , Tang Jiaqi
Published: January 2021

Military weapons and equipment have been working under harsh and complex conditions for a long time during their service. Due to external loads and environmental corrosion, load-bearing beams, engine blades, fixed connectors and other stressed components are prone to fatigue defects and even brittle fractures caused by stress concentration. Socio-economic and operating personnel’s life safety poses a huge threat. Based on electromagnetic eddy current testing, this paper mainly studies the influence of metal material stress on material conductivity and establishes a mathematical model of conductivity and stress through experiments to provide theoretical help for sensor measurement signal processing.
Design and Implementation of Charging and Discharging Device for Electric Inland River Cruise ship
Authors: Yu Zhang Ze
Published: January 2021

This paper designs a charging and discharging device for electric ships. The electric ships’ battery is very large, when performing charge and discharge control of the battery system, it is necessary to manage the charge and discharge current of the battery system reasonably. The battery charging and discharging device can convert the voltage of the energy storage system with a large variation range into a stable DC output voltage, which can control the charge and discharge current of each cluster, and complete the charge and discharge management of each battery cluster. The battery charging and discharging device can be quickly and dynamically adjusted to adapt to changes in the load, and has high operating efficiency and power density. This charging and discharging device has been successfully applied to a certain type of inland river pure electric cruise ship, which will significantly improve the reliability of large-capacity lithium battery ships, and significantly improve the environment of the Yangtze River and other inland river economic zones, and has good applicability in the field of new energy ships.
Influence of Cu doping and high-pressure torsion on electrochemical performance of lithium-rich cathode material
Authors: Wang Mingcai , Zhang Fan , Chen Linfeng , Xu Bin , Cui Zhonglu , Edalati Kaveh
Published: January 2021

Lithium-rich manganese based layered oxide yLi2MnO3∙(1-y)LiMO2 (M=Ni, Co and Mn) is one of the candidate materials for high-capacity cathodes in next-generation lithium-ion batteries. Ion doping with cation and introducing oxygen vacancy are regarded as two methods to change the electrochemical performance of Li-rich cathode materials. In this work, Li1.2Mn0.54Co0.13Ni0.13O2 was synthesized via one-step co-precipitation process, ion doping with low cost element Cu as well as high-pressure torsion were carried out to modify the Li-rich material. Results show that doping with Cu can slightly improve the specific discharge capacity as well as the coulombic efficiency which may be attributed to the lower cation mixing degree.
Structure and properties of Mn-Co-Ni-O thin films
Authors: Ma Chao
Published: January 2021

Mn1.56Co0.96Ni0.48O4 (MCN) thin films were prepared by chemical solution deposition method on the silicon substrate. The spinel structure and the dense surface morphology of the MCN thin films were characterized by X-ray diffraction, scanning electron microscopy and atomic force microscopy, respectively. The optical constants of the MCN thin films in the mid-infrared wavelength range were determined by measuring the ellipsometry parameters and modelling through the Drude-Lorentz oscillator dispersion formula. The refractive index decreases while the extinction coefficient increases with the increase of wavelength. The electrical resistance of the MCN thin films decreases rapidly with increasing temperature, indicating an NTC characteristic. It is expected that MCN thin films will show considerable application potential in the infrared detection.
Theory and Experimental Study of Corona Initial E-Field Strength of HVDC Large Fittings
Authors: Shiling Zhang
Published: January 2021

The electrode were used to imitate the valve tower shield plate, grading ring, grading ball and grading shield for UHVDC valve hall. Uneven electric field of the irregular conductor can not be calculated theoretically or measured accurately. The variation of typical electrode corona inception electric field strength is analyzed and threshold value of the corona inception electric field of the valve hall fittings is acquired. With the adequate modification, limited electric field magnitude for the valve hall is proposed. With the gray system MGM (1, M) model fitting and predicting technology, the E-field strength single-point high-precision measurement and the the wide-area time interval corona initial E-field fitting and predicting operation can be realized. The experimental results show that the maximum error is 3.25% within the measured concentration range, which increases with applied voltage. The maximum RSD% is less than 2.7%, showing the good stability. This system can provide the novel method for the study of corona detection of large fittings in UHVDC valve hall.
Morphology and structural Characteristics of TiO2-SiO2 binary glass deposition particles
Authors: Zhang Chenyang , Nie Lanjian , Xiang ZaiKui , Rao Chuandong , Fu Bo , Wang Lei , Shao Zhufeng , Wang Hongjie , Jia Yanan , Wang Hui , Wang Yufen
Published: January 2021

TiO2-SiO2 is a kind of binary component glass material with excellent properties such as high heat impact resistance, welding ability, and the size of the material is insensitive to temperature change. Based on the principle of Chemical Vapor Deposition (CVD), we used silicon tetrachloride and titanium tetrachloride as the raw materials for the preparation of this glass. In this research, we studied the morphology, structure, and particle size distribution of TiO2-SiO2 binary glass particles. The experimental results show that the deposition particles are spherical amorphous nanoparticles with a size of about 100nm, and there is no SiO2 or TiO2 crystalline phase in the particles. This particle structure overcomes the characteristic that TiO2 is easily crystallized in other preparation methods, making preparation for TiO2-SiO2 binary glass possible.
Emerging Aqueous Flow Batteries and Perspectives on Future Development
Authors: Zhang Jiayi
Published: January 2021

Flow battery, as a promising energy storage system, has been interested by researchers for a long time which reveals that the capacity and performance of flow battery is crucial for the usage of inherently intermittent clean energy resources. This work briefly compares three kinds of flow battery which are the most prevailing methods to achieve energy storage. Meanwhile, China is the largest energy producer and consumer in the world, and for this reason, China’s supply chain of raw material and demand for flow battery is critical for development of flow battery. Most of current researches on flow battery are modification on electrolytes, so tailoring on the structure design of flow battery is also a method for performance improvement. At last, a new design of the structure of flow is provided for further researches.
Fabrication of metal/polymer layer structure composites by demulsification-induced fast solidification
Authors: Wang Dan , Zhang Jianfu , Su Zhongmin
Published: January 2021

In this study, a simple and convenient method of demulsification-induced fast solidification was demonstrated to in situ prepare Zn/RE-906 polyurethane acrylate (906) polymer film layer structure composites. The mechanical connection strength between 906 polymer films and Zn, that is, adhesive strength, was characterized via lap shear testing. The adhesive strength between the 906 polymer films and Zn is adjustable by adjusting the adhesive time and adhesive temperature. The 906 polymer films exhibited an outstanding adhesive performance within the temperature range from room temperature to 175?. The 906 polymer films exhibited excellent adhesion capacity with Zn, making them attractive for applications in the automotive and aeronautic.
Finite-difference time-domain simulation of cathodoluminescence patterns of ZnO hexagonal microrods
Authors: Kowalski Bogdan J , Pieniążek Agnieszka , Reszka Anna , Witkowski Bartłomiej S , Godlewski Marek
Published: January 2021

The Finite-Difference Time-Domain (FDTD) numerical simulation method has been applied to interpret cathodoluminecence patterns observed for ZnO nanorods grown by a hydrothermal method. The 3D FDTD simulation reproduced the radial electromagnetic field pattern in the hexagonal resonator, corresponding to the CL emission maps of real ZnO microrods. The simulation result for the H

z
(TE) polarization—the intense field distribution along edges of the structure, in particular in the corners, but weak in the centre—matched the CL pattern particularly well. Since the experiment was not polarization sensitive, we suppose that polarisation sensitive transmission of electromagnetic field through the ZnO/air interface leads to such an observation. The results of the simulation show also that the lack of axial Fabry-Pérot-like resonances in the CL experiments is caused by leaking of the electromagnetic field from the ZnO resonator into the GaN substrate.
Thermal destabilization mechanism of cytochrome c′ from psychrophilic Shewanella violacea
Authors: Sakaguchi Riku , Fujiyoshi So , Wakai Satoshi , Yamanaka Masaru , Sambongi Yoshihiro
Published: January 2021

Cytochrome c′ is a nitric oxide (NO)-binding heme protein found in Gram negative bacteria. The thermal stability of psychrophilic Shewanella violacea cytochrome c′ (SVCP) is lower than those of its homologues from other 2 psychrophilic Shewanella species, indicating that thermal destabilization mechanism for low-temperature adaptation accumulates in SVCP. In order to understand this mechanism at the amino acid level, here the stability and function of SVCP variants, modeled using the 2 homologues, were examined. The variants exhibited increased stability, and they bound NO similar to the wild type. The vulnerability as to the SVCP stability could be attributed to less hydrogen bond at the subunit interface, more flexible loop structure, and less salt bridge on the protein surface, which appear to be its destabilization mechanism. This study provides an example for controlling stability without spoiling function in psychrophilic proteins.
Validation of a Host Gene Expression Test for Bacterial/Viral Discrimination in Immunocompromised Hosts
Authors: Mahle Rachael E , Suchindran Sunil , Henao Ricardo , Steinbrink Julie M , Burke Thomas W , McClain Micah T , Ginsburg Geoffrey S , Woods Christopher W , Tsalik Ephraim L
Published: January 2021

Background

Host gene expression has emerged as a complementary strategy to pathogen detection tests for the discrimination of bacterial and viral infection. The impact of immunocompromise on host-response tests remains unknown. We evaluated a host-response test discriminating bacterial, viral, and noninfectious conditions in immunocompromised subjects.

Methods

An 81-gene signature was measured using real-time–polymerase chain reaction in subjects with immunocompromise (chemotherapy, solid-organ transplant, immunomodulatory agents, AIDS) with bacterial infection, viral infection, or noninfectious illness. A regularized logistic regression model trained in immunocompetent subjects was used to estimate the likelihood of each class in immunocompromised subjects.

Results

Accuracy in the 136-subject immunocompetent training cohort was 84.6% for bacterial versus nonbacterial discrimination and 80.8% for viral versus nonviral discrimination. Model validation in 134 immunocompromised subjects showed overall accuracy of 73.9% for bacterial infection (P = .04 relative to immunocompetent subjects) and 75.4% for viral infection (P = .30). A scheme reporting results by quartile improved test utility. The highest probability quartile ruled-in bacterial and viral infection with 91.4% and 84.0% specificity, respectively. The lowest probability quartile ruled-out infection with 90.1% and 96.4% sensitivity for bacterial and viral infection, respectively. Performance was independent of the type or number of immunocompromising conditions.

Conclusions

A host gene expression test discriminated bacterial, viral, and noninfectious etiologies at a lower overall accuracy in immunocompromised patients compared with immunocompetent patients, although this difference was only significant for bacterial infection classification. With modified interpretive criteria, a host-response strategy may offer clinically useful diagnostic information for patients with immunocompromise.
Acute kidney injury in 3182 patients admitted with COVID-19: a single-center, retrospective, case–control study
Authors: Procaccini Fabio L , Alcázar Arroyo Roberto , Albalate Ramón Marta , Torres Aguilera Esther , Martín Navarro Juan , Ryan Murua Pablo , Cintra Cabrera Melissa , Ortega Díaz Mayra , Puerta Carretero Marta , de Sequera Ortiz Patricia
Published: January 2021

Background

Acute kidney injury (AKI) may develop in coronavirus disease 2019 (COVID-19) patients and may be associated with a worse outcome. The aim of this study is to describe AKI incidence during the first 45 days of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in Spain, its reversibility and the association with mortality.

Methods

This was an observational retrospective case–control study based on patients hospitalized between 1 March and 15 April 2020 with SARS-CoV-2 infection and AKI. Confirmed AKI cases were compared with stable kidney function patients for baseline characteristics, analytical data, treatment and renal outcome. Patients with end-stage kidney disease were excluded.

Results

AKI incidence was 17.22% among 3182 admitted COVID-19 patients and acute kidney disease (AKD) incidence was 6.82%. The most frequent causes of AKI were prerenal (68.8%) and sepsis (21.9%). Odds ratio (OR) for AKI was increased in patients with pre-existent hypertension [OR 2.58, 95% confidence interval (CI) 1.71–3.89] and chronic kidney disease (CKD) (OR 2.14, 95% CI 1.33–3.42) and in those with respiratory distress (OR 2.37, 95% CI 1.52–3.70). Low arterial pressure at admission increased the risk for Stage 3 AKI (OR 1.65, 95% CI 1.09–2.50). Baseline kidney function was not recovered in 45.73% of overall AKI cases and in 52.75% of AKI patients with prior CKD. Mortality was 38.5% compared with 13.4% of the overall sample population. AKI increased mortality risk at any time of hospitalization (hazard ratio 1.45, 95% CI 1.09–1.93).

Conclusions

AKI is frequent in COVID-19 patients and is associated with mortality, independently of acute respiratory distress syndrome. AKD was also frequent and merits adequate follow-up.
Metaheuristic-Enabled Artificial Neural Network Framework For Multimodal Biometric Recognition With Local Fusion Visual Features
Authors: Gokulkumari G
Published: January 2021

Biometric systems depending on ‘one-modal biometrics’ do not meet up with the required performance necessities for huge user appliances, owing to certain issues like ‘noisy data, intra-class variations, restricted degrees of freedom, spoof attacks and unacceptable error rates’. This work tends to discover a multimodal biometric recognition (MBR) model that includes three main phases like ‘(i) pre-processing, (ii) segmentation, (iii) feature extraction and (iv) classification’. Initially, the images are pre-processed and those pre-processed images are subjected to segmentation. In this context, segmentation is carried out using the Otsu thresholding model. The segmented images are then subjected to a feature extraction process. This work exploits local feature extraction, where ‘Gabor filter features, Zernibe moment features and proposed local binary pattern features’ are extracted. Subsequently, the fusion framework is developed, which has enhanced classification abilities with minimal dimension for MBR. As the next process, recognition takes place by the optimized neural network (NN) model. As a novelty, the training of NN is carried out using a new modified dragonfly algorithm by selecting the optimal weight. Finally, analysis is carried out for validating the betterment of the presented model in terms of different measures.
Elevational and Latitudinal Changes in Cold Tolerance of Nymph and Adult Mormon Crickets Anabrus simplex (Orthoptera: Tettigoniidae)
Authors: Srygley Robert B
Published: January 2021

Insects that hatch in winter and early spring in desert and montane regions are likely to encounter extreme weather events, including precipitous drops in temperature. The susceptibility of insects to exposure to subzero temperatures is predicted to decrease with increasing latitude or elevation. Mormon crickets occur over a broad latitudinal range from southwestern United States to Canada and a broad elevational range from near sea-level to 3,000 m. Population declines have been attributed to late freezing events, but winter hatching suggests they may also be cold tolerant. Lower lethal temperature of high elevation populations in low latitude Arizona (AZ) and high latitude Wyoming (WY) was measured by exposing nymphs and adults to 6 h or 24 h of subzero temperature. From similar latitude, WY was compared with mid-elevation Idaho (ID) and low elevation Oregon (OR) populations. Contrary to the prediction, lethal temperature of third instar nymphs was lower in AZ than in the more northerly populations. Consistently, AZ was more tolerant of cold in early nymphal instars relative to populations from higher latitude. Early hatching at lower latitudes might increase the risk of early instars experiencing a severe cold snap relative to nymphs at high latitudes. Also, contrary to prediction, the lethal temperature of adults increased with elevation, whereas third instar nymphs from mid-elevation ID were the most susceptible to cold exposure. Cold tolerance in immature and mature stages is more likely to be uncoupled when life stages do not coincide, as with Mormon crickets.
Right coronary artery–left ventricular fistula with giant right coronary artery of diffuse ectasia: a case report
Authors: Zhang Qiuxia , Chen Yaode , Hou Yuqing , Xiu Jiancheng
Published: January 2021

Background

Coronary artery fistula complicated with giant coronary artery ectasia (CAE) is a rare cardiac malformation, and its surgical indications and treatment strategies still need further discussion.

Case summary

In this case, a 41-year-old man had complained of occasional dizziness for 2 years, but he did not seek medical attention until he started to feel palpitations. A right coronary artery (RCA)–left ventricular (LV) fistula with giant RCA of diffuse ectasia was firstly revealed by transthoracic echocardiography. A widened left ventricle and significantly constricted right atrium and right ventricle were also detected by three-dimensional coronary artery computed tomography. Surgical treatment, including the repair of the RCA-LV fistula, the resection and reconstruction of the dilated RCA and coronary artery bypass grafting (CABG) under hypothermic cardiopulmonary bypass, were performed to correct the malformation. The patient presented a favourable health condition without any discomfort at the 1-year follow-up.

Discussion

CAE can be caused by various congenital or acquired factors. Surgical treatment, such as transcatheter embolization excision, surgical ligation or resection for symptomatic patients with CAE three times or larger than the reference diameter, has been reported to have satisfactory results. Additionally, CABG can be selected if myocardial perfusion is compromised and the distal branch is of reasonable size. In this case, the giant ectasia of the RCA may have been a consequence of the congenital RCA-LV fistula. Atherosclerosis, with calcified plaques in the RCA, and the patient’s long-term history of smoking may have contributed to the development of giant ectasia of the RCA.
A Composite Likelihood Approach for Dynamic Structural Models
Authors: Canova Fabio , Matthes Christian
Published: January 2021

We explain how to use the composite likelihood function to ameliorate estimation, computational and inferential problems in dynamic stochastic general equilibrium models. We combine the information present in different models or data sets to estimate the parameters common across models. We provide intuition for why the methodology works and alternative interpretations of the estimators we construct and of the statistics we employ. We present a number of situations where the methodology has the potential to resolve well-known problems and to provide a justification for existing practices that pool different estimates. In each case, we provide an example to illustrate how the approach works and its properties in practice.
Is radial artery occlusion and local vascular complications following transradial coronary procedures affected by the type of haemostasis device used? A non-inferiority Randomized Controlled Trial (RadCom trial)
Authors: Due-Tønnessen Nicole , Egeland Cecile H , Meyerdierks Oliver J , Opdahl Anders
Published: January 2021

Aims

Vascular access site complications following transradial coronary procedures are less common and severe compared to femoral approach. Radial artery occlusion is considered the main adverse effect. As radial access is gaining more acknowledgement, complication awareness, and understanding is important. The aim was to assess complication rates following transradial coronary procedures and to compare two radial compression devices in a non-inferiority randomized controlled trial.

Methods and results

Four hundred and ninety-nine patients were randomized to radial compression with a new device (RY Stop, n = 248) or the reference device (TR Band, n = 251) following transradial coronary procedures. Radial artery occlusion persistent at 90 days was the primary endpoint. Discomfort and accounts of vascular complications at access site were secondary endpoints. Radial artery occlusion was observed in 5% (n = 26) for the entire cohort with no difference between groups (RY Stop 6% vs. TR Band 5%; P = 0.69). Patients overall reported low levels of discomfort and the median scores were similar in both groups; RY Stop: 7 vs. TR Band: 10 (P = 0.90). There were few incidents of bleeding (7%), however, they were significantly more frequent with the RY Stop (12%) than with the TR Band (3%; P = 0.001). Few patients (4%) developed access site haematomas, and the incidence was similar in the two groups (P = 0.98).

Conclusion

We observed a radial artery occlusion rate of 5% at 90 days post-procedure. Access site discomfort and vascular complication rates were low. Overall, the RY Stop compression device was not inferior to the TR Band except occurrences of bleeding.
Correlation of Seed Weight and Nurserybed Traits with 5-, 10-, and 15-Year Volumes in a Loblolly Pine Progeny Test
Authors: Robinson John F. , van Buijtenen J. P.
Published: January 2021

Seed weight and nurserybed traits of loblolly pine families measured in detail in 1958 were compared to volumes attained 5, 10, and 15 years after outplanting. Three out of eight characteristics showed significant correlations. These were: (1) percent of seedlings within a family with distinct terminal buds in December, (2) percent of seedlings within a family without basal branches and (3) seed weight. A multiple regression was developed using two of these characteristics to predict volume at age 15. Although the regression R² value was low, a genetic gain of 8.0 percent could have been realized by selecting the best 20 percent of the families from the nurserybed. Forest Sci. 25:591-596.
Economic Impacts of Controlling Soil Loss from Silvicultural Activities in East Texas
Authors: Hickman Clifford A. , Jackson Ben D.
Published: January 2021

A linear programming model was used to study some of the economic consequences of imposing controls to limit soil loss from silvicultural activities in a northeast Texas county. Specifically, four control alternatives were evaluated in terms of their impacts on aggregate net income to forest landowners and aggregate timber output. These alternatives were an aggregate soil loss limit, a per unit area soil loss limit, a tax on excess soil loss, and a subsidy for reduced soil loss. It was found that each of these controls necessitated substantial reductions in landowner income and timber output to achieve only modest reductions in soil loss. The significance of these results is discussed, as is the potential usefulness of the linear programming model as a basis for decisionmaking about the economic rationality of silvicultural nonpoint source controls. Forest Sci. 25:627-640.
Continuous Forest Inventory Using a Linear Filter
Authors: Dixon Bruce L. , Howitt Richard E.
Published: January 2021

Timber management may be conceptualized as a stochastic optimal control problem because of uncertainty about forest dynamics and the sequential nature of the decisionmaking process. Given this point of view, it follows that decisions will be based on the conditional distributions of unknown model parameters where the distributions are derived recursively. By making various approximations, the management actions become a function of the conditional mean of timber inventories. This conditional mean and the conditional covariance of the inventories are generated by a Kalman filter. The conditional mean can alternatively be interpreted as an estimate of the unknown timber inventories. This estimate thus has the virtue of being optimal with respect to the overall timber management problem. The partial replacement estimator of Ware and Cunia is shown to be a special case of the Kalman estimator. The variance of the Ware and Cunia estimator is always greater than or equal to the variance of the corresponding Kalman estimator. Numerical results show that the variance of the Kalman estimator is almost always less than the variance of the Ware and Cunia estimator. In some cases when using the Kalman filter simple random sampling is shown to yield estimates with lower variance than partial replacement sampling. Forest Sci. 25:675-689.
Early Revegetation and Nutrient Dynamics Following the 1971 Little Sioux Forest Fire in Northeastern Minnesota
Authors: Ohmann Lewis F. , Grigal David F.
Published: January 2021

Three virgin plant communities dominated by Pinus banksiana, three by Populus-Betula, and one mixed community were studied over five growing seasons after burning in the 1971 Little Sioux Fire. From 1971 through 1975 tree and tall shrub reproduction generally decreased in density and increased in biomass. Low shrub cover and biomass increased for 3 years and then leveled off as tree and tall shrub competition increased. Herb cover and biomass increased most rapidly through 1972 and then slowed substantially. By 1975 total net primary productivity averaged 850 g/m²/yr for all seven stands, and over 1,200 g/m²/yr in the broadleaf-dominated stands. The forest floor 01 horizon increased in mass through 1974, and then apparently stabilized at about 620 g/m². The 02 horizon averaged about 1,000 g/m² and was still increasing in 1975. By the 1975 growing season the total amount of nutrients in aboveground vegetation on burned plots ranged from 33 percent of the N to 65 percent of the K found in nearby unburned forest communities. By 1973 the nutrients in the aboveground vegetation and the 01 horizon of the forest floor were greater than the quantity estimated to have been mobilized by the fire. The vegetation was an effective sink for the released nutrients.
FACTORS INFLUENCING FITNESS IN CHROMOSOMAL STRAINS IN DROSOPHILA SUBOBSCURA
Authors: Wasserman Marvin
Published: January 2021

Chromosomal polymorphism can be maintained by means of genic dominance, genic overdominance, recombination effects and karyotype selection. Experiments were carried out which allow us to distinguish among these factors as they effect egg hatch and larva-to-adult survival in D. subobscura. A strong karotype selection was observed. A small but highly significant recombination effect was also observed despite the fact that the material used in the experiment consisted of inbred, related strains and was therefore less likely to show such an effect than strains randomly chosen from a population. On the other hand, these strains, being inbred, were more likely to show genic dominance or genic overdominance than randomly picked samples. However neither genic dominance nor genic overdominance was detected.
MAINTENANCE OF GENETIC VARIATION WITH A FREQUENCY-DEPENDENT SELECTION MODEL AS COMPARED TO THE OVERDOMINANT MODEL
Authors: Hedrick Philip W
Published: January 2021

A frequency-dependent selection model proposed by Huang, Singh and Kojima (1971) was found to be more effective at maintaining genetic variation in a finite population than the overdominant model. The fourth moment parameter of the distribution of unfixed states showed that there was a more platykurtic distribution for the frequency-dependent model. This agreed well with the expected gene frequency change found for an infinite population.
Phenotype and Natural History of Children With Coexistent Inflammatory Bowel Disease and Celiac Disease
Authors: Bramuzzo Matteo , Lionetti Paolo , Miele Erasmo , Romano Claudio , Arrigo Serena , Cardile Sabrina , Di Nardo Giovanni , Illiceto Maria Teresa , Pastore Maria , Felici Enrico , Fuoti Maurizio , Banzato Claudia , Citrano Michele , Congia Mauro , Norsa Lorenzo , Pozzi Elena , Zuin Giovanna , Agrusti Anna , Bianconi Martina , Grieco Claudia , Giudici Fabiola , Aloi Marina , Alvisi Patrizia
Published: January 2021

Background

Adult patients with both inflammatory bowel disease (IBD) and celiac disease (CeD) have peculiar phenotypic features. This study aimed at describing the characteristics and natural history of children with both IBD and CeD.

Methods

This was a case-control study based on a national registry. Cases included children diagnosed with both IBD and CeD. Two matched IBD controls without CeD, and 2 matched CeD controls were selected for each case. Inflammatory bowel disease phenotype and natural history, comprising growth and pubertal development, were compared between groups.

Results

Forty-nine (1.75%) patients with IBD and CeD were identified out of 2800 patients with IBD. Compared with patients with IBD alone, patients with IBD and CeD presented more frequently with autoimmune diseases (odds ratio, 2.81; 95% CI, 0.97–8.37; P = 0.04). Ileocolonic localization (46.1% vs 73.1%), treatment with azathioprine (46.2% vs 71.2%), and anti-TNF biologics (46.2% vs 69.2%) were less common in patients with Crohn’s disease and CeD than in patients with Crohn’s disease alone. Patients with ulcerative colitis and CeD had an increased risk of colectomy despite similar medical treatments compared with patients with ulcerative colitis alone (13.0% vs 0%). Pubertal delay was more common in patients with IBD and CeD compared with patients with IBD alone (14.9% vs 3.2%; odds artio, 5.24; 95% CI, 1.13–33.0; P = 0.02) and CeD alone (14.9% vs 1.1%; P = 0.002).

Conclusions

Children with IBD and CeD may have peculiar features with a higher risk for autoimmune diseases, colectomy, and pubertal delay compared with IBD alone.
Mid-term outcomes of coronary artery bypass grafting in patients with mild left ventricular systolic dysfunction: a multicentre retrospective cohort study
Authors: Zhang Hang , Shi Ronghui , Qin Wei , Chen Wen , Li Liangpeng , Wang Wuwei , Zhao Yang , Wang Rui , Chen Xin
Published: January 2021

OBJECTIVES

Left ventricular systolic dysfunction (LVSD) is common and associated with adverse events in patients receiving coronary artery bypass grafting (CABG). However, the prognosis of mild LVSD has not been clearly described. We aimed to evaluate the mid-term outcomes of patients with mild LVSD following CABG.

METHODS

This multicentre cohort study using propensity score matching took place from December 2012 to October 2019 in Jiangsu Province, China, with a mean and maximum follow-up of 3.2 and 7.2 years, respectively. Patients were classified to normal left ventricular systolic function (left ventricular ejection fraction ≥53%) and mild LVSD (left ventricular ejection fraction >40%/<53%). The primary outcomes were death from all causes and death from cardiovascular causes. The secondary outcomes were heart failure, myocardial infarction, repeat revascularization and a composite of all mentioned outcomes, including death from all causes (major adverse events).

RESULTS

A total of 581 pairs were formed after matching. In-hospital death (1.5% vs 2.1%, P = 0.51) did not differ between 2 cohorts. Throughout 7 years, mild LVSD was associated with higher rates of death from all causes [hazard ratio (HR) 0.59, 95% confidence interval (CI) 0.39–0.89; P = 0.012], death from cardiovascular causes (HR 0.55, 95% CI 0.36–0.90; P = 0.017), heart failure (HR 0.60, 95% CI 0.37–0.93; P = 0.023) and major adverse events (HR 0.66, 95% CI 0.49–0.91; P = 0.009). There was no difference in the rates of myocardial infarction and repeat revascularization.

CONCLUSIONS

Mild LVSD was associated with a worse mid-term prognosis in patients following CABG.
Host Patch Use and Potential Competitive Interactions Between Two Egg Parasitoids From the Family Scelionidae, Candidate Biological Control Agents of Bagrada hilaris (Hemiptera: Pentatomidae)
Authors: Hougardy Evelyne , Hogg Brian N
Published: January 2021

Two egg parasitoids from Pakistan, Gryon sp. nr. gonikopalense Sharma (Hymenoptera: Scelionidae) and Trissolcus hyalinipennis Rajmohana & Narendran (Hymenoptera: Scelionidae), are currently being investigated as potential classical biocontrol agents for Bagrada hilaris Burmeister. The former is the most promising because of its ability to attack B. hilaris eggs in soil, but the latter was recently discovered in California. This study detailed the patch use and oviposition behavior of both species and assessed their relative foraging efficiency. We also investigated possible competitive interactions by assessing 1) the occurrence of intra- and interspecific host discrimination, 2) mutual interference between females (extrinsic competition), 3) the outcome of multiparasitism (intrinsic competition), and 4) the effect of competition on host suppression. Our results showed that T. hyalinipennis females tended to probe repeatedly in the same hosts leading to longer host patch time and lower foraging efficiency. Both species avoided conspecific superparasitism, but not multiparasitism. When the two species foraged simultaneously, G. sp. nr. gonikopalense seemed to be slightly superior in extrinsic competition, while neither species seemed to have an advantage in intrinsic competition. Also, neither species could develop as a facultative hyperparasitoid, but they inflicted non-reproductive mortality on eggs containing 4-d-old larvae of their competitor. Lastly, host mortality inflicted by G. sp. nr. gonikopalense and T. hyalinipennis when acting together appeared to be additive. These results suggest that the presence of T. hyalinipennis in California is unlikely to reduce G. sp. nr. gonikopalense efficiency, but will instead improve the biological control of B. hilaris.
Survey of Wheat Stem Sawfly (Hymenoptera: Cephidae) Infesting Wheat in Eastern Colorado
Authors: Cockrell Darren M , Randolph Terri , Peirce Erika , Peairs Frank B
Published: January 2021

From 2012 through 2020, a survey of wheat stem sawfly, Cephus cinctus Norton, was conducted in wheat (Triticum aestivum L.) fields in Eastern Colorado. In 2013, results showed sawfly infestations concentrated in the northern part of the state with only a few highly infested sites, with 38 of the 94 sampled sites having any infestation (five of which had >50% infestation levels). By 2020 sawfly had been found in all eastern counties sampled, and 72 of the 106 sites sampled were found to contain sawfly (11 of which had >50% infestation levels). The spread of this pest across the Colorado wheat-growing region will have lasting economic effects. The information gathered from this and future surveys will inform wheat variety development and aid in management decisions made by growers across the state.
Heterologous production of cyanobacterial compounds
Authors: Dhakal Dipesh , Chen Manyun , Luesch Hendrik , Ding Yousong
Published: January 2021

Cyanobacteria produce a plethora of compounds with unique chemical structures and diverse biological activities. Importantly, the increasing availability of cyanobacterial genome sequences and the rapid development of bioinformatics tools have unraveled the tremendous potential of cyanobacteria in producing new natural products. However, the discovery of these compounds based on cyanobacterial genomes has progressed slowly as the majority of their corresponding biosynthetic gene clusters (BGCs) are silent. In addition, cyanobacterial strains are often slow-growing, difficult for genetic engineering, or cannot be cultivated yet, limiting the use of host genetic engineering approaches for discovery. On the other hand, genetically tractable hosts such as Escherichia coli, Actinobacteria, and yeast have been developed for the heterologous expression of cyanobacterial BGCs. More recently, there have been increased interests in developing model cyanobacterial strains as heterologous production platforms. Herein, we present recent advances in the heterologous production of cyanobacterial compounds in both cyanobacterial and noncyanobacterial hosts. Emerging strategies for BGC assembly, host engineering, and optimization of BGC expression are included for fostering the broader applications of synthetic biology tools in the discovery of new cyanobacterial natural products.
Improved early warning of compact binary mergers using higher modes of gravitational radiation: a population study
Authors: Singh Mukesh Kumar , Kapadia Shasvath J , Shaikh Md Arif , Chatterjee Deep , Ajith Parameswaran
Published: January 2021

A gravitational wave early warning of a compact binary coalescence event, with a sufficiently tight localization skymap, would allow telescopes to point in the direction of the potential electromagnetic counterpart before its onset. Use of higher modes of gravitational radiation, in addition to the dominant mode typically used in templated real-time searches, was recently shown to produce significant improvements in early-warning times and skyarea localizations for a range of asymmetric mass binaries. We perform a large-scale study to assess the benefits of this method for a population of compact binary merger observations. In particular, we inject 100 000 such signals in Gaussian noise, with component masses $m_1 \in \left[1, 60 \right] \, \mathrm{M}_{\odot }$ and $m_2 \in \left[1, 3 \right] \, \mathrm{M}_{\odot }$. We consider three scenarios involving ground-based detectors: the fifth (O5) observing run of the Advanced LIGO-Virgo-KAGRA network, its projected Voyager upgrade, as well as a proposed third-generation (3G) network. We find that for fixed early-warning times of 20–60 s, the inclusion of the higher modes can provide localization improvements of a factor of ≳2 for up to ${\sim}60{{\ \rm per\ cent}}$ ($70 {{\ \rm per\ cent}}$) of the neutron star–black hole (NSBH) systems in the O5 (Voyager) scenario. Considering only those NSBH systems that can produce potential electromagnetic counterparts, such improvements in the localization can be expected for ${\sim}5\!-\!35{{\ \rm per\ cent}}$  $(20\!-\!50{{\ \rm per\ cent}})$ binaries in O5 (Voyager). For the 3G scenario, a significant fraction of the events have time gains of a minute to several minutes, assuming fiducial target localization areas of 100–1000 deg2.
Detecting episodes of star formation using Bayesian model selection
Authors: Lawler Andrew J , Acquaviva Viviana
Published: January 2021

Bayesian model comparison frameworks can be used when fitting models to data in order to infer the appropriate model complexity in a data-driven manner. We aim to use them to detect the correct number of major episodes of star formation from the analysis of the spectral energy distributions (SEDs) of galaxies, modelled after 3D-HST galaxies at z ∼ 1. Starting from the published stellar population properties of these galaxies, we use kernel density estimates to build multivariate input parameter distributions to obtain realistic simulations. We create simulated sets of spectra of varying degrees of complexity (identified by the number of parameters), and derive SED fitting results and pieces of evidence for pairs of nested models, including the correct model as well as more simplistic ones, using the bagpipes codebase with nested sampling algorithm multinest. We then ask the question: is it true – as expected in Bayesian model comparison frameworks – that the correct model has larger evidence? Our results indicate that the ratio of pieces of evidence (the Bayes factor) is able to identify the correct underlying model in the vast majority of cases. The quality of the results improves primarily as a function of the total S/N in the SED. We also compare the Bayes factors obtained using the evidence to those obtained via the Savage–Dickey density ratio (SDDR), an analytic approximation that can be calculated using samples from regular Markov Chain Monte Carlo methods. We show that the SDDR ratio can satisfactorily replace a full evidence calculation provided that the sampling density is sufficient.
Excision and End-to-End Anastomosis of a Giant Partially Thrombosed Cervical Internal Carotid Artery Aneurysm Mimicking a Neck Tumor: 2-Dimensional Operative Video
Authors: Khan Nickalus R , Shah Ashish , Morcos Jacques J
Published: January 2021

Aneurysms of the cervical internal carotid artery (ICA) are a rare entity
1,2
accounting for less than 0.2% to 0.5% of all carotid surgeries
3
and less than 1% of all arterial aneurysms.
4
There are several types of aneurysms, which include dissecting aneurysms, pseudoaneurysms, mycotic aneurysms, and fusiform and saccular aneurysms.
5
The causes can include atherosclerosis, trauma, infection, and dysplasia. We present the case of a 70-yr-old otherwise healthy female found to have a neck mass. She was referred from a peripheral vascular surgeon to a head and neck surgeon for potential biopsy. The head and neck surgeon obtained vascular imaging and referred the patient to neurosurgery for definitive management. The patient gave informed consent for the procedure. An excision of the cervical ICA aneurysm and reanastomosis of the cervical ICA was performed. The patient remained neurologically intact postoperatively and imaging demonstrated complete aneurysm occlusion and a patent cervical ICA anastomosis.

The patient gave verbal consent for this case to be published.
Nerve Splitting and Vascular Transposition for Trigeminal Neuralgia Attributed to Nerve Penetrating Trigeminocerebellar Artery: 2-Dimensional Operative Video
Authors: Goto Yukihiro , Inoue Takuro
Published: January 2021

The trigeminocerebellar artery (TCA) is an infrequent anatomic anomaly of the branches originating from the basilar artery. It is clinically identifiable by the presence of the ipsilateral superior cerebellar artery and the anterior inferior cerebellar artery, and its course from the basilar artery to the cerebellar hemisphere. Because of its anatomic proximity to the trigeminal nerve root, the TCA often causes trigeminal neuralgia (TGN). Unlike other common arteries, repositioning the TCA is not always feasible when it penetrates the trigeminal nerve root (the intraneural type of TCA). In addition, the rich perforators originating from the TCA may limit its movability. The nerve decompression technique in such a rare condition has not yet been fully assessed. In this video, we present the nerve-splitting method for the intraneural type of TCA, in which sufficient isolation of the sensory root is achieved. The motor root of the trigeminal nerve originates from the brainstem slightly rostral of the root entry zone of the sensory root. Dissecting the motor root from its exit to the porous trigeminus allows mobilization of the root together with penetrating TCA away from the sensory root. The movability of the TCA increases by dissecting its perforators to the nerve root and brain stem. Sufficient separation of the sensory root contributes to ensuring the surgical result of nerve decompression and reducing the risk of recurrence due to adhesion. No complications of motor root retraction, such as masseter weakness and malocclusion, were noted in our experience.

All data identifying the patients were anonymized. All procedures performed in this study were in accordance with the ethical standards of our institutional and national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. This study also obtained approval from the ethics committee of our institution. Written informed consent was obtained from all individual participants, as well as their first-degree relatives, included in this study.
‘Candidatus Liberibacter solanacearum’ Infection of Physalis ixocarpa Brot. (Solanales: Solanaceae) in Saltillo, Mexico
Authors: Reyes-Corral Cesar A. , Cooper W. Rodney , Karasev Alexander V. , Delgado-Luna Carolina , Sanchez-Peña Sergio R.
Published: January 2021

The potato psyllid Bactericera cockerelli (Šulc) (Hemiptera: Triozidae) is a pest of solanaceous crops (order Solanales), including potato (Solanum tuberosum L.) and tomato (S. lycopersicum L.). Feeding by high populations of nymphs causes psyllid yellows while adults and nymphs are vectors of the plant pathogen ‘Candidatus Liberibacter solanacearum’. Foliar symptoms that were consistent with either ‘Ca. L. solanacearum’ infection or psyllid yellows were observed in 2019 on tomatillo (Physalis ixocarpa Brot.; family Solanaceae) grown within an experimental plot located near Saltillo, Mexico. This study had three primary objectives: 9i) determine whether the foliar symptoms observed on tomatillo were associated with ‘Ca. L. solanacearum’ infection, (ii) identify the haplotypes of ‘Ca. L. solanacearum’ and potato psyllids present in the symptomatic plot, and (iii) use gut content analysis to infer the plant sources of ‘Ca. L. solanacearum’-infected psyllids. Results confirmed that 71% of symptomatic plants and 71% of psyllids collected from the plants were infected with ‘Ca. L. solanacearum’. The detection of ‘Ca. L. solanacearum’ in plants and psyllids and the lack of nymphal populations associated with psyllid yellows strongly suggests that the observed foliar symptoms were caused by ‘Ca. L. solanacearum’ infection. All infected plants and insects harbored the more virulent ‘Ca. L. solanacearum’ haplotype B but one psyllid was also coinfected with haplotype A. The potato psyllids were predominantly of the central haplotype but one psyllid was identified as the western haplotype. Molecular gut content analysis of psyllids confirmed the movement of psyllids between noncrop habitats and tomatillo and indicated that ‘Ca. L. solanacearum’ infection of psyllids was associated with increased plant diversity in their diet.