bluuebunny/crossref_metadata_2025 huggingface dataset:
Geological hazard interpretation and hazard evaluation of open pit mines based on Unmanned Aerial Vehicle images
Authors: Ma Jianxiong , Liu Jiwen , Ming Jing , Sang Xuejia
Published: August 2021

Over-exploitation of open-pit mines has caused extensive development of geological hazards, posing serious threats to people and buildings in the area. Based on the UAV tilt-tilt photography technology, this paper generates a real-world 3D model of the study area, taking the molybdenum mine of Songshumao in Yangjiajiaozi, Xingcheng City, Liaoning Province as an example, and combines orthophotography, high-precision DEM data and field geological survey research to establish a geohazard interpretation marker for the study area and interpret various types of geohazards such as landslides, landslides, dangerous rocks, ground cracks and unstable slopes in the study area. Based on the hierarchical analysis method combined with the geological environment characteristics, the geological hazard risk evaluation model and index system were established, and five indexes were selected, including geological hazard range, stratigraphic lithology, slope, elevation, vegetation coverage, etc. The study area was divided into high, medium and low risk zones, and the geological hazard risk zoning map was obtained to complete the geological hazard risk evaluation of the study area.
Effect of multiple extrusion on phase structure and properties of impact copolymerized polypropylene
Authors: Xiaoyan LIU , Dongbo ZHAO , Shoujun DENG , li LI , Hongyi DUAN
Published: August 2021

As a typical multi-component polymer, impact polypropylene copolymer (IPC) experiences the phase structure evolution during repeated processing, and the coarsening of phase domain often occurs. In this work, two IPCs with different molecular weight of rubber phase were compared systemically. The evolution of IPC phase morphology and crystallization behavior after multiple extrusion were studied through scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The materials mechanical properties were tested. Then the influence of rubber phase molecular weight on the phase morphology evolution and the properties after repeated extrusion were discussed in detail. It was found that for the IPC with low molecular weight of rubber phase, the size of rubber phase became smaller and dispersed more evenly with the increase of extrusion times; for the IPC with high molecular weight of rubber phase, the rubber phase size turned to unstable after multiple shearing. The rubber phase size had a complex effect on IPC mechanical properties.
The influence of molecular structure on the thermal properties and processability of nitrile-based resin molecules
Authors: Mengdi Chen , Wei Liao , Changping Yin , Suli Xing , Su Ju , Liping Sheng
Published: August 2021

With the increase in the speed of various aircraft and the demand for lightweight weapons and equipment, the demand for high-performance, high-temperature-resistant resin-based composite materials has become more urgent. The temperature resistance and molding process of composite materials are determined by the temperature resistance and manufacturability of the resin, so there is an urgent need to develop a resin that has both high temperature resistance and excellent process performance. The temperature resistance and processability of the resin are essentially determined by the molecular structure of the resin system. Therefore, in order to design a resin system with excellent heat resistance and processability, the relationship between molecular structure and performance must first be recognized. This paper collects a large amount of experimental data and preliminarily summarizes the influence of different molecular structures on the thermal performance and resin processability of resin polymers from the perspective of structure and performance. This provides a good experience and theoretical basis for the design of high-performance resin systems, providing references and ideas for related research.
Performance Evaluation of Polypropylene Resin for Capacitor Film
Authors: Sainan SONG , Xia WANG , Ruijuan MU , Zhaoliang XING , Xiying Dai
Published: August 2021

The molecular structure and mechanical properties of 3 kinds of imported polypropylene particles for capacitor film were analyzed by Gel Permeation Chromatograph (GPC), differential scanning calorimeter (DSC) and electronic tensile machine. The results showed that the melt index of imported polypropylene for capacitor film was about 3.0g/10min, the ash content was about 20ppm, the isotacticity index was higher than 98.5%, the crystallinity was higher than 45%, and the molecular weight distribution was wider than 6.0. The data showed these three kinds of imported polypropylene for capacitor film were all low-ash and higher isotactic polypropylene with high crystallinity and good mechanical tensile properties.
Adsorption characteristics of carbon nanotubes on low concentration erythromycin in water
Authors: Wang Tao , Kuang Bin , Li Zhensheng , Lin Ziyang , Du Siyuan , Guo Bing
Published: August 2021

Multi-walled carbon nanotubes (MWNTs) were used to adsorb low concentration erythromycin from natural water. The kinetic curves and adsorption isotherms were measured and the thermodynamic parameters were calculated. The effects of pH value, ionic strength and humic acid on the adsorption process were investigated. The results showed that the adsorption of carbon nanotubes to erythromycin was rapid in the first 40 min, and reached equilibrium within 200 min. The dynamics curve conforms to the quasi-second-order dynamics model. The Freundlich model can better fit the adsorption test data. Thermodynamic parameters show that the adsorption of Erythromycin by MWNTs is a spontaneous endothermic process. The adsorption activation energy Ea shows that the adsorption between MWNTs and erythromycin is a chemisorption process, and the content of oxygen-containing functional groups on the surface of CNTs determines the equilibrium adsorption amount. Ionic strength has obvious effect on adsorption. Increasing the pH value of the solution from 5 to 9 was beneficial to increasing the adsorption capacity of erythromycin. The adsorption capacity of carbon nanotubes to erythromycin was significantly increased with appropriate humic acid.
Analysis and Comparison on Dynamic Characteristics of CFST Arch Bridge
Authors: Ji Jing , Lin Yubo , Xu Ming , Zhong Meihui , Jiang Liang qin
Published: August 2021

In order to obtain the natural frequency and vibration mode of concrete-filled steel tube (CFST) arch bridge with different parameters, the modal analysis of a double-span arch bridge with a total length of 257.4 meters and a full width of 31.8 meters is carried out. By controlling the three variables of concrete strength, steel tube thickness and the number of transverse braces in arch ribs, the regularity of the natural frequency and vibration mode of CFST arch bridge with different variables is discussed. The results show that with the increasing of the strength of concrete-filled steel tube in arch ribs, the fundamental frequency increases gradually. The vertical stiffness of the arch bridge is positively related to the thickness of the arch rib steel pipe. The fundamental frequency of the arch bridge can be improved by setting transverse brace, and the change of the number of transverse braces has a significant effect on the sixth-order natural frequency. It is limited for the arch bridge to improve the stiffness by changing the number of transverse braces. These can lay the foundation for the dynamic response analysis of the CFST arch bridge.
Research Progress on Comprehensive Utilization of Red Mud
Authors: Lingxiang HUANG , Chunlei LI , Haibin WANG , Xingxing LI , Yongrong QI , Xuechen ZHU
Published: August 2021

Red Mud(RM), a kind of hazardous solid wastes produced during the process of alumina production, is disadvantageous for our environments owning to its characters of strong alkali and rich salt. It is essential to conduct innocent treatment. Summarizing the hazards of RM and methods of its comprehensive utilization, A reference for the deeper comprehensive utilization of RM in the future in this review was provided.
Design and research of uranium-containing wastewater treatment equipment based on new organometallic framework materials (MOF-808)
Authors: Rong Lishan , Huang Zefeng , Ouyang Ji , Liu Shaoqian , Yuan Bin , Xia Lin , Xiong Chaofan
Published: August 2021

With the significant increase in the amount of natural uranium mining in various countries around the world, a large amount of waste rocks are piled up in the tailings pond. If the uranium-containing wastewater is not treated, it will bring serious environmental problems. After related experiments in the laboratory, it is measured that the adsorption rate of high-tech products-MOF-808 material to uranium ions can reach 97% (the optimal pH=7.0, and the optimal dosage is 0.2mg/L). It can be used as a good adsorption material. Based on the high-efficiency selective adsorption of this material to uranium, a set of equipment using MOF-808 was designed in this paper. This device adopts improved intermittent processing, high integration and automation level, and small floor space. According to the desorption characteristics of the material, a simple membrane cleaning method is designed to recover high-concentration uranium-containing cleaning liquid, which greatly reduces the amount of mud and can produce considerable economic benefits. In addition, cleaning and operation can be carried out at the same time, realizing continuous uranium-containing wastewater treatment, which meets the requirements of energy saving and emission reduction, and is beneficial to the construction of green mines.
Research on fragmentation quality percentage of coal in hot air dense medium fluidized bed
Authors: Li Lingyue
Published: August 2021

This paper studies the percentage of pulverized coal in the hot air dense medium fluidized bed, and investigates the influence of coal surface moisture, drying temperature, drying time, air volume and other factors on the percentage of crushing, and establishes a mathematical correlation formula for the percentage of crushing; it shows that with the increase of drying temperature, the percentage of crushing increases; with the increase of air volume, the percentage of crushing increases; the percentage of crushing increases with the increase of drying time and increases with the increase of surface moisture of coal.
Experimental study on shortcut simultaneous nitrogen removal in treating domestic sewage
Authors: Pengsheng ZHENG , Yan XIAO , Jianchao YANG , Fei HONG
Published: August 2021

To treat domestic sewage with high efficacy and low cost, the technology of shortcut simultaneous nitrogen removal was used with a new biofilm reactor. The influences on nitrogen removal effect by start-up procedure, nitrogen transformation characteristics and main factors (hydraulic retention time, dissolved oxygen, carbon-nitrogen ratio) were analyzed. The results indicate that: The reactor finished start-up of shortcut simultaneous nitrogen removal in 14 days of cultivation time after the biofilm cultured in the carrier. The ammonia nitrogen removal rate, simultaneous nitrification-denitrification rate and cumulative nitrite nitrogen rate respectively reached 91.3%, 82.7% and 63.4% in the last phase of start-up procedure. To remove ammonia nitrogen with the technology of shortcut simultaneous nitrogen removal efficiently and steadily, hydraulic retention time, dissolved oxygen, carbon-nitrogen ratio should be controlled in 3.56 hours, 1.5 mg/L and 5~8.
Directly freeze-drying porous graphene aerogel as acoustic-absorbing material
Authors: Li Zengling , Chen Nan , Qu Liangti
Published: August 2021

Noise pollution, which is no less harmful than air, water and soil pollution, is becoming an environmental shortcoming that cannot be ignored. Scientists are also seeking various solutions to work on reducing noise pollution. In this work, porous graphene aerogel (FD-GA) and porous graphene oxide aerogel (FD-GOA) prepared by foaming combined with freeze-drying are reported as acoustic-absorbing materials. The effects of thickness and degree of compression on the acoustic-absorbing performance of FD-GA and FD-GOA in the 1000-6000 Hz range, where human ear hearing is sensitive, were investigated, respectively. FD-GA was found to have significantly higher acoustic absorption performance with a peak absorption of 96.7%. The present work provides a simple and straightforward strategy for the synthesis of the acoustic-absorbing material. Key words: freeze-drying, graphene aerogel, acoustic-absorbing
Sedimentary characteristics of Yan 6 oil layer of Yan’an Formation in X area of Ordos Basin
Authors: Zhao Meifang , Wang Jifeng
Published: August 2021

Using core, mud logging and logging data, the study on the sedimentary characteristics of the Yan 6 oil layer of the Yan'an Formation in the X area of the Ordos Basin was carried out. It is believed that the Yan 6 oil layer in X area mainly develops delta deposits, and the subfacies is delta plain. The sedimentary microfacies are mainly diversion channels, inter-branch swamps and natural dikes. According to coring well data, sand body shape analysis, and logging facies analysis. Vertically, the sand bodies in the Yan 6 oil layer group are discontinuous, and there are mainly distributary channels and inter-branch swamps. Horizontally, the Yan 6 oil layer group develops 7 river channels, which are distributed in a strip on the plane, and the extension direction is northwest-south east. The comprehensive characterization of the sedimentary microfacies and the distribution of reservoir sand bodies in Yan 6 oil layer provides a reliable basis for the oil field to adjust the oil production plan in time.
Active underwater acoustic control of polymer based piezoelectric composites
Authors: Simin Zou
Published: August 2021

Acoustic stealt of the submarin has always been the most valuable research field for Security Department of the Navy over the world. In this paper, the feasibility of underwater anechoic coating with the polymer matrix piezoelectric composite material has been studied. On the basis of the Thomson-Haskell matrix method, we have derived the reflected transform matrix and calculated a semi-analytical solution to the problem by using the MATLAB. It is found that the underwater anechoic effects of this new material are related to the material proportion of each composites, the control voltage, geometric parameters, incident angle and frequency and so on. The studies have showed that: the polymer matrix piezoelectric composite material takes the advantages of both the viscoelastic material and the piezoelectric material and the use of the new material has a superior nature than the traditional materials to the suppression of underwater acoustic reflection.
Pretreatment in the Determination of Trace Copper and Iron in Transformer Oil
Authors: Liang Qinqin , Luo Zongchang
Published: August 2021

Comparative trace copper and iron analysis of unused and running transformer oil is performed by iCP-MS with pretreatment by ashing, acid dissolution and direct injection method. The advantages and drawbacks of each of the listed methods are discussed. The direct injection method is so simple and time-consuming that can realize accurate determination of copper in oil, while it is not suitable for determination of iron in used transformer oil. Although limited by availability of equipment, acid dissolution method has good accuracy and reproducibility for the determination of transformer oil in all states.
Ionization of H(2p) atom by 30 keV proton and antiproton impact
Authors: Nassar Tarek E I
Published: August 2021

Ionization process of the hydrogen atom, being initially in the excited 2p-state, projected by 30 keV proton and antiproton impact has been investigated. The second-Born approximation (SBA) is used to measure the triple differential cross sections (TDCSs). The closure relation is employed on the second-Born term to come over consideration of the intermediate states. The triple differential cross-sections are represented graphically against the ejection angle, for two scattering angles and ejected energies into both scattering and perpendicular geometric planes. The single differential cross-section (SDCS) is calculated in the framework of the first-Born approximation.
Collective behavior of coupled multiplicative processes with stochastic resetting
Authors: Gómez Garay Ignacio T , Zanette Damián H
Published: August 2021

A dynamical variable driven by the combination of a deterministic multiplicative process with stochastic reset events develops, at long times, a stationary power-law distribution. Here, we analyze how such distribution changes when several variables of the same kind interact with each other through diffusion-like coupling. While for weak coupling the variables are still distributed following power-law functions, their distributions are severely distorted as interactions become stronger, with sudden appearance of cutoffs and divergent singularities. We explore these effects both analytically and numerically, for coupled ensembles of identical and non-identical variables. The most relevant consequences of ensemble heterogeneity are assessed, and preliminary results for spatially distributed ensembles are presented.
Representative methods of computational socioeconomics
Authors: Zhou Tao
Published: August 2021

The increasing availability of data sources and analysis tools borrowed from computer science and physical science have sharply changed traditional methodologies of social sciences, leading to a new branch named computational socioeconomics, which studies various phenomena in socioeconomic development by using quantitative methods based on large-scale real-world data. Sited on recent publications, this perspective will introduce three representative methods: (i) natural data analyses, (ii) large-scale online experiments, and (iii) integration of big data and surveys. This perspective ends up with in-depth discussion on the limitations and challenges of the above-mentioned emerging methods.
Protection of Copyright in Foreign Works in Nigeria: An Analysis of the Decision in Voice Web International Limited v Emerging Markets Telecommunication Services Ltd & Ors
Authors: Adewopo Adebambo , Itanyi Nkem
Published: August 2021

The protection for copyright in foreign works in Nigeria has been a contentious and controversial issue for over three decades. In this case analysis, through a trilogy of cases, we trace the judicial trend and jurisprudence on this issue of copyright law. We argue that although Sec. 5 and Sec. 41 of the Nigerian Copyright Act provide two methods by which foreign works can receive protection under the Act, the courts have repeatedly declined to confer such protection. The most recent case on this issue, Voice Web International Limited v Emerging Markets Telecommunication Services Ltd & Ors, provided an opportunity for the courts to lay the issue to rest; however, unfortunately, the courts again failed to do so. In this opinion, we critically examine the case and discuss the legislative history conferring protection to foreign works. We conclude that the correct statutory interpretation in determining the protection of foreign works is reciprocity, and this was satisfied in the case under review.
Rapid structure-function insights via hairpin-centric analysis of big RNA structure probing datasets
Authors: Radecki Pierce , Uppuluri Rahul , Aviran Sharon
Published: August 2021

The functions of RNA are often tied to its structure, hence analyzing structure is of significant interest when studying cellular processes. Recently, large-scale structure probing (SP) studies have enabled assessment of global structure-function relationships via standard data summarizations or local folding. Here, we approach structure quantification from a hairpin-centric perspective where putative hairpins are identified in SP datasets and used as a means to capture local structural effects. This has the advantage of rapid processing of big (e.g. transcriptome-wide) data as RNA folding is circumvented, yet it captures more information than simple data summarizations. We reformulate a statistical learning algorithm we previously developed to significantly improve precision of hairpin detection, then introduce a novel nucleotide-wise measure, termed the hairpin-derived structure level (HDSL), which captures local structuredness by accounting for the presence of likely hairpin elements. Applying HDSL to data from recent studies recapitulates, strengthens and expands on their findings which were obtained by more comprehensive folding algorithms, yet our analyses are orders of magnitude faster. These results demonstrate that hairpin detection is a promising avenue for global and rapid structure-function analysis, furthering our understanding of RNA biology and the principal features which drive biological insights from SP data.
Assessment of the Diversity and Inclusion Culture in a Physician Assistant Program
Authors: Palfreyman Lori Parlin , Joseph Jennifer , Parrott James Scott
Published: August 2021

Purpose

Physician assistant (PA) programs aim to foster a collaborative culture that enables stakeholders to feel included, empowered, and valued. The purpose of this study was to explore the cultural climate of diversity and inclusion in one PA program to identify areas of strength and to serve as a baseline needs assessment for future program initiatives.

Methods

The study used a cross-sectional, descriptive approach for PA survey data (N = 85) to assess perceptions of diversity and inclusion of PA program students, faculty, and staff.

Results

The respondents largely agreed that the program created an inclusive learning environment (92%), the curriculum positively affected their understanding of diversity and cultural responsiveness (84.6%), and the program had an adequate amount of inclusivity for all program stakeholders (87%). Some faculty members (25%) and students (6.2%) disagreed that faculty were open to diverse political beliefs, and 35% of the respondents believed that more emphasis could be put on religious diversity. A few students (7.7%) perceived faculty as not supportive of non-native English language speakers; students of color (11.5%) were more likely than White students (5.1%) to have this perception.

Conclusions

This study largely met the goal to create a professional environment of mutual respect and, ultimately, a climate of inclusiveness. It also identified opportunities for new initiatives to meet the needs of all program stakeholders. Follow-up research that distinguishes faculty from students and a multicenter study to explore perspectives based on demographic differences would be timely and useful.
Marixanthomonas spongiae sp. nov., isolated from marine sponge
Authors: Zhuang Lingping , Pang Haiyue , Xu Li , Chen Dan
Published: August 2021

A novel bacterial strain, designated as HN-E44T, was isolated from marine sponge collected from Yangpu Bay, Hainan, PR China. Strain HN-E44T was Gram-stain-negative, non-motile, catalase-positive, oxidase-negative, rod-shaped and yellow-pigmented. Growth occurred at 4–37 °C (optimum, 28 °C), at pH 6–8 (pH 7) and in 0.5–14 % (w/v) NaCl (3–5 %). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain HN-E44T formed an independent cluster with

Marixanthomonas ophiurae

JCM 14121T within the family

Flavobacteriaceae

and had the highest sequence similarity of 93.6 % to the closest type strain

M. ophiurae

JCM 14121T. The major fatty acids were iso-C15 : 0, anteiso-C15 : 0, iso-C17 : 0 3-OH, summed feature 3 (C16 : 1
 ω7c and/or C16 : 1
 ω6c) and iso-C15 : 1 G. The polar lipids comprised phosphatidylethanolamine, sphingolipid, four unidentified phospholipids, an unidentified aminophospholipid and an unidentified lipid. The respiratory quinone was identified as MK-6. The genomic DNA G+C content was determined to be 40.6 mol%. The average nucleotide identity (ANI) and average amino acid identity (AAI) values between strain HN-E44T and closest type strain

M. ophiurae

JCM 14121T were, respectively, 79.6 and 85.2 %, both of which were below thresholds for species delineation (95–96 % ANI and 95–96 % AAI), but were over thresholds for genus delineation (73.98 % ANI and 70–76 % AAI). The combined genotypic and phenotypic distinctiveness demonstrated that strain HN-E44T could be differentiated from closely related genera. Therefore, it is proposed that strain HN-E44T represents a novel species of the genus

Marixanthomonas

, for which the name Marixanthomonas spongiae sp. nov. is proposed, with the type strain HN-E44T (=MCCC 1K03332T=LMG 30459T).
Improving the reproduction number calculation by treating for daily variations of SARS-CoV-2 cases
Authors: Drewes Harry , Fläschner Gotthold , Möller Peter
Published: August 2021

The Covid-19 pandemic impacted the human life all over the globe, starting in the year of its emergence, 2019, and in the following years. A epidemiological key indicator that gained particular recognition in politics and decision making is the time-dependent reproduction number Rt, which is commonly calculated by institutions responsible for disease control following a method presented by Cori et. al. Here, we propose an improved as well as an alternative method, which make the calculation more stable against oscillations arising from daily variations in testing. Both methods can be used without great statistical knowledge or effort. The methods provides a smoother result without increasing the time-lag, and provides an advantage particular in the timeframe of weeks, which might serve as a better ground for forecasts and the raising of alarms.
Physician reimbursement and retention in HIV care: Racial disparities in the US South
Authors: Pan Zhongzhe , Dahman Bassam , Bono Rose S. , Sabik Lindsay M. , Belgrave Faye Z. , Nixon Daniel E. , Kimmel April D.
Published: August 2021

Fewer than 60% of Americans diagnosed with HIV are retained in care, with racial disparities. Addressing structural barriers to care may improve outcomes along the HIV care continuum, such as retention, and promote health equity. We examined the relationship between physician reimbursement and retention in HIV care, including racial differences. Data included person-level demographic information and administrative claims (Medicaid Analytic eXtract, 2008-12), state Medicaid-to-Medicare fee ratios (Urban Institute, 2008, 2012), and county characteristics for 15 Southern states plus District of Columbia. The fee ratio is a standardized measure of physician reimbursement capturing state variation in Medicaid relative to Medicare physician reimbursement, which is largely consistent across states. We used generalized estimating equations to assess the association between physician reimbursement ratio and retention in HIV care (≥2 claims for physician visits, antiretroviral prescriptions, or CD4 or HIV RNA viral load tests ≥90 days apart in a calendar-year). We also evaluated an increase in the fee ratio to parity, where Medicaid and Medicare physician reimbursement are equal. Stratified analysis assessed racial differences. The sample included 55,237 adult Medicaid enrollees living with HIV (179,002 enrollee-years). Enrollees were retained in HIV care for approximately three-quarters (76.8%) of their enrollment-years, with retention lower among non-Hispanic Black (76.2%) versus non-Hispanic White (81.3%, p<0.001) enrollees. A 10-percentage point increase in physician reimbursement was associated with a 4% increase in the odds of retention (aOR 1.04, 95% CI 1.01, 1.08). In stratified analysis, increased physician reimbursement was significantly associated with retention among non-Hispanic Black but not non-Hispanic White enrollees. At parity, predicted retention was 81.1% (80.0%, 82.1%) and 80.4% (79%, 81.7%) of enrollment-years, overall and for non-Hispanic Black enrollees, respectively. Higher physician reimbursement improves retention in HIV care, particularly among non-Hispanic Black individuals living with HIV, and could be a structural mechanism to promote racial equity in retention.
Cerebrospinal fluid concentration of complement component 4A is increased in first-episode schizophrenia
Authors: Gracias Jessica , Orhan Funda , Hörbeck Elin , Holmén-Larsson Jessica , Khanlarkani Neda , Malwade Susmita , Goparaju Sravan K. , Schwieler Lilly , Fatourus-Bergman Helena , Pelanis Aurimantas , Goold Carleton P. , Goulding Anneli , Annerbrink Kristina , Isgren Anniella , Sparding Timea , Schalling Martin , Yañez Viviana A. Carcamo , Göpfert Jens C. , Nilsson Johanna , Brinkmalm Ann , Blennow Kaj , Zetterberg Henrik , Engberg Göran , Piehl Fredrik , Sheridan Steven D. , Perlis Roy H. , Cervenka Simon , Erhardt Sophie , Landen Mikael , Sellgren Carl M.
Published: August 2021

Excessive synapse loss is a core feature of schizophrenia and is linked to the complement component 4A gene (C4A). In two independent cohorts, we show that cerebrospinal fluid (CSF) C4A concentration is elevated in first-episode psychosis patients who develop schizophrenia and correlates with CSF measurements of synapse density. Using patient-derived cellular modeling, we find that disease-associated cytokines increase neuronal C4A expression and that IL-1β associates with C4A in patient-derived CSF.
Microfluidics-Enabled Digital Isothermal Cas13a Assay
Authors: Liu Frank X. , Cui Johnson Q. , Park Hojeong , Chan Ka Wai , Leung Tyler , Tang Ben Zhong , Yao Shuhuai
Published: August 2021

The isothermal molecular diagnosis with CRISPR has attracted particular interest for the sensitive, specific detection of nucleic acids. However, most of the assays with Cas enzymes were performed in bulk assays using multistep approaches and hard to realize quantitative detection. Herein, we report Microfluidics-Enabled Digital Isothermal Cas13a Assay (MEDICA), a digital format of SHERLOCK with enhanced robustness and sensitivity. We first address the macromolecular crowding problems when combining the recombinase polymerase amplification (RPA) and Cas13a detection into a one-pot SHERLOCK assay. After the assay optimization, the enhanced one-pot SHERLOCK (E-SHERLOCK) achieves high robustness and 200-fold increased sensitivity. Leveraging droplet microfluidics, we streamline the E-SHERLOCK to eliminate undesired input targets caused by pre-amplification before partition, enabling background-free absolute quantification. From the real-time monitoring, MEDICA enables qualitative detection within 10 min and absolute quantification within 25 min. For the proof of concept, we applied MEDICA to quantify HPV 16 and 18 viral loads in 44 clinical samples, indicating perfect accordance with qPCR results. MEDICA highlights the CRISPR-based isothermal assays are promising for the next generation of point-of-care diagnostics.
Interplay of ADHD polygenic liability with birth-related, somatic and psychosocial factors in ADHD - a nationwide study
Authors: Brikell Isabell , Wimberley Theresa , Albiñana Clara , Jóhann Vilhjálmsson Bjarni , Agerbo Esben , Børglum Anders D. , Demontis Ditte , Schork Andrew J. , LaBianca Sonja , Werge Thomas , Hougaard David M. , Nordentoft Merete , Mors Ole , Mortensen Preben Bo , Petersen Liselotte Vogdrup , Dalsgaard Søren
Published: August 2021

Background

ADHD is multifactorial, yet the interplay ADHD polygenic risks scores (ADHD-PRS) and other ADHD associated risk-factors remains relatively unexplored. The aim of this study was to investigate associations, confounding and interactions of ADHD-PRS with birth, somatic and psychosocial risk-factors previously associated with ADHD.

Methods

Participants came from the Danish iPSYCH2012 case-cohort, including a randomly selected general population sample (N=21,578), and all ADHD cases with an ICD-10 diagnosis F90.0 (N=13,697), born in Denmark 1981-2005. We derived ADHD-PRS and identified 25 ADHD risk-factors in Danish national registers. Logistic regression was used to estimate associations of ADHD-PRS with each risk-factors in the general population. Cox models were applied in the full case-cohort to evaluate confounding of risk-factor associations by ADHD-PRS and family psychiatry history, and interactions between ADHD-PRS and each risk-factor.

Results

ADHD-PRS was associated with 14 out of 25 ADHD risk-factors in the general population, e.g., maternal autoimmune disorder, mild traumatic brain injury (TBI), and most psychosocial risk-factors. In the full case-cohort, 21 risk-factors were associated with ADHD diagnosis. Adjusting for ADHD-PRS and parental psychiatric history only led to minor attenuations of these associations. Interactions were observed between ADHD-PRS and sex, maternal autoimmune disease, TBI, paternal employment and age at child-birth.

Conclusion

Higher ADHD-PRS is associated with exposure to certain birth and somatic ADHD risk-factors, and broadly to psychosocial adversity. Evidence of gene-environment interactions were weak and ADHD-PRS and/or family psychiatric history have limited confounding effect on ADHD risk-factor associations, suggesting that majority of the investigated risk-factors act largely independently of ADHD-PRS to increase risk of ADHD.
Telehealth in Rheumatology: The 2021 Arab League of Rheumatology Best Practice Guidelines
Authors: Ziade Nelly , Hmamouchi Ihsane , Kibbi Lina el , Daou Melissa , Abdulateef Nizar , Abutiban Fatemah , Elzorkany Bassel , Dahou-Makhloufi Chafia , Hamdi Wafa , Emadi Samar Al , Halabi Hussein , Alnaqbi Khalid A. , Abu Al Saoud Sima , Hashad Soad , Niamane Radouane , Rakawi Manal El , Kazkaz Layla , Saad Sahar , Eissa Mervat , Fraser Ilanca , Masri Basel
Published: August 2021

Background

Telehealth use is increasing and will undeniably continue to play a role beyond the COVID-19 era. Best practice guidelines (BPG) for telehealth add credibility, standardize approaches, facilitate reimbursement, and decrease liability.

Objectives

To develop BPG for the use of Telehealth In Rheumatology in the Arab region, to identify the top barriers and facilitators of telehealth in the Arab region, and to provide rheumatologists with a practical toolkit for the implementation of telehealth.

Methods

Guidelines were drafted by a core steering committee from the Arab League of Associations for Rheumatology (ArLAR) after performing a literature search. A multidisciplinary task force (TF), including 18 rheumatologists, 2 patients, and 2 regulators from 15 Arab countries, assessed the BPG using 3 rounds of anonymous online voting by modified Delphi process. The voting on barriers and facilitators was performed through one voting round. The toolkit was developed based on available literature and discussions during the Delphi rounds.

Results

Four General Principles and twelve Statements were formulated. All statements reached >80% consensus. A teleconsultation was specifically defined for the purpose of these guidelines. The concept of choice in telehealth was highlighted, emphasizing patient confidentiality, medical information security, rheumatologist’s clinical judgment, and local jurisdictional regulations. The top barrier for telehealth was the concern about the quality of care. The toolkit emphasized technical aspects of teleconsultation and proposed a triage system.

Conclusions

The ArLAR BPG provides rheumatologists with a series of strategies about the most reliable, productive, and rational approaches to apply telehealth.

Article Summary

Strengths and limitations of this study

Best practice guidelines (BPG) the use of Telehealth In Rheumatology in the Arab region were developed herein under the umbrella of the Arab League of Associations for Rheumatology (ArLAR)

A teleconsultation was specifically defined for the purpose of these guidelines

The concept of choice in telehealth was highlighted, emphasizing patient confidentiality, medical information security, rheumatologist’s clinical judgment, and local jurisdictional regulations

The top barrier for telehealth was the concern about the quality of care

The ArLAR BPG provides rheumatologists with a series of strategies about the most reliable, productive, and rational approaches to apply telehealth in the rheumatology clinic
Evolutionary dynamics of a virus in a vaccinated population
Authors: Bell Graham
Published: August 2021

The progress of an epidemic in a small closed community is simulated by an agent-based model which allows vaccination and variation. The attributes of the virus are governed by two genetic loci: the P-locus, which determines growth, and the M-locus, which determines immune characteristics. Mutation at either locus modifies the attributes of the virus and leads to evolution through natural selection. For both loci the crucial variable is the potential mutation supply UPot, because evolution is likely to happen when UPot> 1. Mutation at the P-locus causes a limited increase in virulence, which may be affected by vaccine design. Mutation at the M-locus may cause a qualitative shift of dynamic regime from a simple limited epidemic to a perennial endemic disease by giving rise to escape mutants which may themselves mutate. A broad vaccine that remains efficacious despite several mutations at the M-locus prevents this shift and provides protection despite the evolution of the virus. Escape variants may nevertheless arise through recombination after coinfection, and can be suppressed by timely revaccination, using the prevalent strain to design the vaccine.
COVID-19 mitigation measures in primary schools and association with infection and school staff wellbeing: an observational survey linked with routine data in Wales, UK
Authors: Marchant Emily , Griffiths Lucy , Crick Tom , Fry Richard , Hollinghurst Joe , James Michaela , Cowley Laura , Abbasizanjani Hoda , Torabi Fatemeh , Thompson Dan , Kennedy Jonathan , Akbari Ashley , Gravenor Michael , Lyons Ronan A , Brophy Sinead
Published: August 2021

Introduction

School-based COVID-19 mitigation strategies have greatly impacted the primary school day (children aged 3-11) including: wearing face coverings, 2-metre distancing, no mixing of children, and no breakfast clubs or extra-curricular activities. This study examines these mitigation methods and association with COVID-19 infection, respiratory infection, and school staff wellbeing between October to December 2020 in Wales, UK.

Methods

A school staff survey captured self-reported COVID-19 mitigation measures in the school, participant anxiety and depression, and open-text responses regarding experiences of teaching and implementing measures. These survey responses were linked to national-scale COVID-19 test results data to examine association of measures in the school and the likelihood of a positive (staff or pupil) COVID-19 case in the school (clustered by school, adjusted for school size and free school meals using logistic regression). Linkage was conducted through the SAIL (Secure Anonymised Information Linkage) Databank.

Results

Responses were obtained from 353 participants from 59 primary schools within 15 of 22 local authorities. Having more direct non-household contacts was associated with a higher likelihood of COVID-19 positive case in the school (1-5 contacts compared to none, OR 2.89 (1.01, 8.31)) and a trend to more self-reported cold symptoms. Staff face covering was not associated with a lower odds of school COVID-19 cases (mask vs. no covering OR 2.82 (1.11, 7.14)) and was associated with higher self-reported cold symptoms. School staff reported the impacts of wearing face coverings on teaching, including having to stand closer to pupils and raise their voices to be heard. 67.1% were not able to implement 2-metre social distancing from pupils. We did not find evidence that maintaining a 2-metre distance was associated with lower rates of COVID-19 in the school.

Conclusions

Implementing, adhering to and evaluating COVID-19 mitigation guidelines is challenging in primary school settings. Our findings suggest that reducing non-household direct contacts lowers infection rates. There was no evidence that face coverings, 2-metre social distancing or stopping children mixing was associated with lower odds of COVID-19 or cold infection rates in the school. Primary school staff found teaching challenging during COVID-19 restrictions, especially for younger learners and those with additional learning needs.
Reconstructing the biogeography of a hunter-gatherer planet using machine-learning
Authors: Hamilton Marcus J. , Walker Robert S. , Buchanan Briggs , Blasi Damian E. , Bowern Claire L.
Published: August 2021

Estimating the total human population size (i.e., abundance) of the preagricultural planet is important for setting the baseline expectations for human-environment interactions if all energy and material requirements to support growth, maintenance, and well-being were foraged from local environments. However, demographic parameters and biogeographic distributions do not preserve directly in the archaeological record. Rather than attempting to estimate human abundance at some specific time in the past, a principled approach to making inferences at this scale is to ask what the human demography and biogeography of a hypothetical planet Earth would look like if populated by ethnographic hunter-gatherer societies. Given ethnographic hunter-gatherer societies likely include the largest, densest, and most complex foraging societies to have existed, we suggest population inferences drawn from this sample provide an upper bound to demographic estimates in prehistory. Our goal in this paper is to produce principled estimates of hunter-gatherer abundance, diversity, and biogeography. To do this we trained an extreme gradient boosting algorithm (XGBoost) to learn ethnographic hunter-gatherer population densities from a large matrix of climatic, environmental, and geographic data. We used the predictions generated by this model to reconstruct the hunter-gatherer biogeography of the rest of the planet. We find the human abundance of this world to be 6.1±2 million with an ethnolinguistic diversity of 8,330±2,770 populations, most of whom would have lived near coasts and in the tropics.

Significance Statement

Understanding the abundance of humans on planet Earth prior to the development of agriculture and the industrialized world is essential to understanding human population growth. However, the problem is that these features of human populations in the past are unknown and so must be estimated from data. We developed a machine learning approach that uses ethnographic and environmental data to reconstruct the demography and biogeography of planet Earth if populated by hunter-gatherers. Such a world would house about 6 million people divided into about 8,330 populations with a particular concentration in the tropics and along coasts.
Getting the gist faster: Blurry images enhance the early temporal similarity between neural signals and convolutional neural networks
Authors: Tovar David A. , Grootswagers Tijl , Jun James , Cha Oakyoon , Blake Randolph , Wallace Mark T.
Published: August 2021

Humans are able to recognize objects under a variety of noisy conditions, so models of the human visual system must account for how this feat is accomplished. In this study, we investigated how image perturbations, specifically reducing images to their low spatial frequency (LSF) components, affected correspondence between convolutional neural networks (CNNs) and brain signals recorded using magnetoencephalography (MEG). Using the high temporal resolution of MEG, we found that CNN-Brain correspondence for deeper and more complex layers across CNN architectures emerged earlier for LSF images than for their unfiltered broadband counterparts. The early emergence of LSF components is consistent with the coarse-to-fine theoretical framework for visual image processing, but surprisingly shows that LSF signals from images are more prominent when high spatial frequencies are removed. In addition, we decomposed MEG signals into oscillatory components and found correspondence varied based on frequency bands, painting a full picture of how CNN-Brain correspondence varies with time, frequency, and MEG sensor locations. Finally, we varied image properties of CNN training sets, and found marked changes in CNN processing dynamics and correspondence to brain activity. In sum, we show that image perturbations affect CNN-Brain correspondence in unexpected ways, as well as provide a rich methodological framework for assessing CNN-Brain correspondence across space, time, and frequency.
Deciphering the major metabolic pathways associated with aluminum tolerance in popcorn roots using label-free quantitative proteomics
Authors: Pinto Vitor Batista , Almeida Vinícius Costa , Lima Ítalo Antunes Pereira , de Moura Vale Ellen , Araújo Wagner Luiz , Silveira Vanildo , Viana José Marcelo Soriano
Published: August 2021

Aluminum toxicity is one of the most important abiotic stresses that affect crop production worldwide. The soluble form (Al3+) inhibits root growth by altering water and nutrients uptake, which also reduces plant growth and development. Under a long term Al3+ exposure, plants can activate several tolerance mechanisms, and to date, there are no reports of large-scale proteomic data of maize in response to this ion. To investigate the post-transcriptional regulation in response to Al toxicity, we performed a label-free quantitative proteomics for comparative analysis of two Al-contrasting popcorn inbred lines and an Al-tolerant commercial hybrid during 72 h under Al-stress. A total of 489 differentially accumulated proteins (DAPs) were identified in the Al-sensitive inbred line, 491 in the Al-tolerant inbred line, and 277 in the commercial hybrid. Among them, 120 DAPs were co-expressed in both Al tolerant genotypes. Bioinformatics analysis indicated that starch and sucrose metabolism, glycolysis/gluconeogenesis, and carbohydrate metabolism were significant biochemical processes regulated in response to Al toxicity. The up accumulation of sucrose synthase and the increase of sucrose content and starch degradation suggest that these components may enhance popcorn tolerance to Al stress. The up-accumulation of citrate synthase suggests a key role of this enzyme in the detoxification process in the Al-tolerant inbred line. The integration of transcriptomic and proteomic data indicated that the Al tolerance response presents a complex regulatory network into the transcription and translation dynamics of popcorn roots development.