bluuebunny/crossref_metadata_2025 huggingface dataset:
The solitary wave solutions to the Klein–Gordon–Zakharov equations by extended rational methods
Authors: Yao Shao-Wen , Zekavatmand Sayyed Masood , Rezazadeh Hadi , Vahidi Javad , Ghaemi Mohammad Bagher , Inc Mustafa
Published: June 2021

In this paper, using the extended rational sine–cosine and rational sinh–cosh methods, we find new soliton solutions for the Klein–Gordon–Zakharov equations. The extended rational sine–cosine and rational sinh–cosh methods are prospering in finding soliton solutions of the Klein–Gordon–Zakharov equations. By means of these methods, we found some young solitons of the above mentioned equation. The conclusions we receive are dark, bright, and periodic. In addition, in order to imagine the underlying dynamics of the obtained soliton solutions, 2D and 3D plots are drawn.
Experimental research on the interaction between electromagnetic wave and plasma
Authors: Zhang Wenyuan , Xu Haojun , Song Zhijie , Han Xinmin , Chang Yipeng , Wei Xiaolong , Pei Binbin
Published: June 2021

The basis of plasma stealth technology is the attenuation of electromagnetic waves by plasma. In this study, the calculation principle of the finite-difference time-domain (FDTD) method is introduced and a FDTD time–space coupling model of electromagnetic wave propagation in plasma is established. The time-domain variation characteristics of electromagnetic waves entering the plasma are analyzed. The plasma parameter distribution under different conditions obtained using the COMSOL fluid mechanics model is introduced into the FDTD model. The plasma reflectivity measurement experiment was carried out in a microwave anechoic chamber, and the influence of different experimental conditions on the plasma reflectivity was analyzed. The variation of reflectivity under different plasma parameter distributions is obtained. The results show that increasing electron density and plasma thickness and enhanced plasma distribution uniformity are beneficial for improving the attenuation effect of plasma on electromagnetic waves. These results provide a reference for the inductively coupled plasma parameter distribution in a closed quartz cavity, which provides a basis for the plasma to attenuate the electromagnetic waves.
The Covid-19 shutdown: when studying turns digital, students want more structure
Authors: Gjerde Vegard , Gray Robert , Holst Bodil , Kolstø Stein Dankert
Published: June 2021

In March 2020, universities in Norway and many other countries shut down due to the Covid-19 pandemic. The students lost access to classrooms, libraries, study halls, and laboratories. Studying turned digital. Because it is unclear when this pandemic will cease to affect students and because we cannot know whether or when a new pandemic occurs, we need to find ways to improve digital study-life for students. An important step in this direction is to understand the students’ experiences and perspectives regarding how the digitalization affected their study-life both in structured learning arenas and their self-study. Therefore, we interviewed 12 students in an introductory mechanics course at a Norwegian university in June of 2020. Through a thematic analysis, we identified four broad categories in the students’ different experiences and reflections, namely that digitalization: (a) provides benefits, e.g. the flexibility inherent in online video lectures; (b) incurs learning costs, e.g. students reducing their study effort; (c) incurs social costs, e.g. missing being around other students; and (d) increases the need for structure, e.g. wanting to be arranged in digital groups to solve mandatory tasks. We also found that the 2019 students on average scored significantly better on the final exam than the 2020 students, d = 0.31, but we discuss why this result should be interpreted with caution. We provide suggestions for how to adapt courses to make students’ digital studying more socially stimulating and effective. Furthermore, this study is a contribution to the historical documentation of the Covid-19 pandemic.
A 3.3 kV 4H-SiC split gate MOSFET with a central implant region for superior trade-off between static and switching performance
Authors: Yoon Jongwoon , Kim Kwangsoo
Published: June 2021

A split gate MOSFET (SG-MOSFET) is widely known for reducing the reverse transfer capacitance (C
RSS). In a 3.3 kV class, the SG-MOSFET does not provide reliable operation due to the high gate oxide electric field. In addition to the poor static performance, the SG-MOSFET has issues such as the punch through and drain-induced barrier lowering (DIBL) caused by the high gate oxide electric field. As such, a 3.3 kV 4H-SiC split gate MOSFET with a grounded central implant region (SG-CIMOSFET) is proposed to resolve these issues and for achieving a superior trade-off between the static and switching performance. The SG-CIMOSFET has a significantly low on-resistance (R
ON) and maximum gate oxide field (E
OX) due to the central implant region. A grounded central implant region significantly reduces the C
RSS and gate drain charge (Q
GD) by partially screening the gate-to-drain capacitive coupling. Compared to a planar MOSFET, the SG MOSFET, central implant MOSFET (CIMOSFET), the SG-CIMOSFET improve the R
ON×Q
GD by 83.7%, 72.4% and 44.5%, respectively. The results show that the device features not only the smallest switching energy loss but also the fastest switching time.
Experimental study on Mechanical Properties of green and environmental friendly self-compacting recycled concrete
Authors: Ma Zhijian , Fang Guangxiu , Liang Zuoyin , Jin Dagen
Published: June 2021

By replacing cement with 5% of ground rice husk powder, 4% of corn stalk powder and 30% of fly ash, and replacing natural aggregate with 25% recycled aggregate, the Mechanical Properties of green and environment-friendly self-compacting recycled concrete were studied. The experimental results show that the early strength of the concrete is lower than the common self-compacting concrete. However, the strength of 56 days is up to the design requirement and the volume stability is good. According to the test value of the compressive strength of the concrete block, the curve equation of the relationship between the compressive strength and the age is put forward, and it provides a reference for similar concrete mix proportion design.
Experimental study on mix proportion of green environmental protection type three-doped fair-faced concrete
Authors: Zhang Ting , Fang Guangxiu , Chen Han , Cui Wenshuo
Published: June 2021

Fair-faced concrete has been favored by the majority of architectural and structural designers. In response to the sustainable development strategy of our government, this paper studies the green environment-friendly fair-faced concrete mixed with agricultural and industrial wastes. Based on the statistical analysis of the existing literature on fair-faced concrete, the green environmental protection of fair-faced concrete was considered comprehensively. The mix proportion of “three-doped” fair-faced concrete mixed with ground rice husk ash, fly ash and mineral powder, which replaced the cement amount by 8%, 20% and 6% respectively, and its influence on compressive strength were studied through experiments. The experimental results show that the green environmental protection type fair-faced concrete mixed with rice husk ash, fly ash and mineral powder can achieve requirements of the compressive strength by the design. And the growth rate of compressive strength from the 28th day to the 56th day is higher than that of ordinary fair-faced concrete. At the same time, the curve equation of the relationship between the compressive strength and the age is put forward, and the fit is good, which can provide reference for the design of similar concrete mix proportion.
Analysis of tower foundation of long span single tower cable stayed bridge
Authors: Liu Bo-Hai
Published: June 2021

The pylon is an important stressed structure in the single pylon cable-stayed bridge. The rationality of bearing platform and pile foundation of pylon foundation is one of the key research contents in the design of single pylon cable-stayed bridge. The main bridge of Tarim bridge in Xinjiang is a single tower double span cable-stayed bridge with span arrangement of (41 + 168 + 168 + 41) m and total height of cable tower of 125m. Arc shaped concrete tower columns are adopted. The stress of cable tower foundation is complex. The stress analysis of foundation scheme is one of the key problems of this project. In this paper, the geological conditions, structural stress, economic rationality, construction convenience and other factors are comprehensively considered, the different foundation types are compared and analyzed, the reasonable foundation type and layout type are determined, and the stress of the pile and cap structure of the main tower foundation is calculated and analyzed. Through the solid finite element model, this paper analyzes the influence of the stiffness deformation of pile cap on the stress of pile group foundation. The calculation results show that the stress of dumbbell shaped pile cap is more reasonable than that of rectangular foundation pile cap, and the number of pile foundation and the calculated pile length are reduced in varying degrees. By adjusting the pile foundation arrangement under dumbbell shaped foundation, the stress of pile foundation can be more uniform, which can be used as the foundation for similar projects. The foundation design provides reference and reference.
A method for calibrating seawater polyaromatic hydrocarbons sensor
Authors: Zhang Li , Wang Yang , Kong Xiangfeng , Wang Jingru , Wang Zhaoyu
Published: June 2021

To solve the problems in the calibration of polyaromatic hydrocarbons sensor used in seawater, we proposed a new method that using 1,5-Naphthalenedisulfonic acid, disodium salt dihydrate instead of polyaromatic hydrocarbons standard substances to calibrate seawater polyaromatic hydrocarbons sensor. Relative to polyaromatic hydrocarbons standard substances, 1,5-Naphthalenedisulfonic acid, disodium salt dihydrate shows higher solubility in seawater, better stability under the detection wavelength of polyaromatic hydrocarbons and lower toxicity to organisms. Our results showed that the relative errors between real concentrations of standard substances and measuring concentrations of these standard substances via 1,5-Naphthalenedisulfonic acid, disodium salt dihydrate-calibrated sensor varied from 5~15%. Our method can reduce the complexity of calibration procedures, and keep the accuracy and precision of sensors in the determination of polyaromatic hydrocarbons in seawater.
Investigation on Carbon Sequestration Capacity of Typical Subtropical Evergreen Broad-leaved Forest in Jiulianshan Nature Reserve
Authors: Zhang Qiugen , Xia Wei , Ding Yuan , Li Jian
Published: June 2021

Nine investigation sample plots (each 20m×20m) were set up to investigate the biomass and soil bulk density of three typical subtropical evergreen broad-leaved forests (Castanopsis eyrei, Schima superba, Cyclobalanopsis glauca) in Jiulianshan National Nature Reserve in Jiangxi Province in 2015 and 2020. The vegetation carbon density and carbon storage, soil carbon density and carbon storage, the carbon density and carbon storage of the investigation sample plots were calculated according to the organic carbon content of vegetation and soil. In addition, the changes in carbon sequestration capacity of three typical subtropical evergreen broad-leaved forests in Jiulianshan National Nature Reserve in Jiangxi Province in 2015 and 2020 were analyzed. The investigation results had shown that:Compared with 2015, the average organic carbon content of Castanopsis eyrei, Cyclobalanopsis glauca, and Schima superba of Jiulianshan National Nature Reserve in Jiangxi Province increased by 10.36%, 10.13% and 7.73% in 2020. The average organic carbon content of leaf, branch, stem and root increased also by 10.60%, 10.38%, 11.13% and 5.29% respectively. The soil organic carbon content of different soil layers in 2020 and 2015 were all decrease with the increase of soil depth. Compared to 2015, the organic carbon content increased while the soil bulk density decreased in 2020.

The average carbon density of the forest vegetation layer in the investigation plots of Jiulianshan National Nature Reserve in Jiangxi Province had increased from 82.63t/hm2 in 2015 to 108.94t/hm2 in 2020. The carbon density of the arbor layer had increased from 76.11t/hm2 in 2015 to 106.09t/hm2 in 2020, while the carbon density of the shrub layer, herbaceous layer and litter layer in 2020 was lower than that in 2015. In 2015 and 2020, the carbon density of different vegetation layers in the three typical subtropical evergreen broad-leaved forest of Castanopsis eyrei, Schima superba and Cyclobalanopsis glauca were all ranked as arbor layer, shrub layer, litter layer and herbaceous layer.

The average soil carbon density (calculated by 10cm) at different depths in 2020 and 2015 in Jiulianshan National Nature Reserve of Jiangxi Province all decreased with the increase of the soil depth. The total average soil carbon density in 2020 was 168.03t/hm2, which was 35.4%% lower than that of 2015(288.05t/hm2).

The average carbon storage in the sample plot (20m×20m) in Jiulianshan National Nature Reserve in Jiangxi Province decreased from 13771.04kg in 2015 to 10688.11kg in 2020 with a decrease of 22.38%. The average carbon storage of vegetation decreased from 3305.20kg in 2015 increased to 4357.60kg in 2020 with an increase of 31.8%, while the average soil carbon storage decreased from 10137.04kg in 2015 to 6475.51kg in 2020 whit a decrease of 36.1%.
Research on Sustainable Conservation of Ancient Villages by Utilizing Digital Technologies
Authors: Li Li , Peng Xuan , Liu Jiamin , Pan Xiang
Published: June 2021

With the coming of the 5G era, it has become a crucial international trend to conserve ancient villages and the sustainability by utilizing multiple digital technologies. The recognition of landscape and culture is a momentous step in the sustainable conservation of ancient villages’ study, as well as the extended application and management approach of data should be considered seriously. In the pages that follow, it tries to provide a conservation method systematically in which emphasizes the integration utilization of digital technologies by taking the Taoping Qiang Stockade Village in Sichuan as a case study. Moreover, this article proposes that the conservation should be carried out at three steps: landscape recognition, establish the data chain and cultural inheritance and dissemination. In general, this essay seeks to explore the utilization of digital technologies and provide a systematic perspective and methodology for the sustainable conservation of ancient villages.
Overview of Research on Monitoring of Marine Oil Spill
Authors: Li Kai , Ouyang Jieming , Yu Hongliang , Xu Yiqun , Xu Jin
Published: June 2021

Marine oil spill monitoring technology has become a hot topic of marine environmental protection. This article introduced the principles and characteristics of marine oil spill monitoring sensors, analysised the implementation methods of marine oil spill monitoring. Through the comparison of the application situation, the problems in the oil spill monitoring are drawn, finally the development of the offshore oil spill monitoring research is prospected.
Research on Natural Disaster Early Warning System Based on UAV Technology
Authors: Wu Bei , Fu Ruyu , Chen Jundao , Zhu Junhui , Gao Rongfang
Published: June 2021

Unmanned aerial vehicle (UAV) and low-altitude remote sensing technology can provide a new technical way for remote sensing monitoring tasks in large-scale and dangerous areas. Through the monomer and visual information query of BIM model, they are organically integrated into the disaster occurrence traceability system, forming a “1+4+N” (a disaster system early warning center, four basic platforms for video surveillance, data service, information sharing and intelligent planning, and the application of multiple scene topics) structure system in disaster system construction. That is, to carry out intelligent, information-based and systematic disaster scenario simulation, prediction analysis and rescue measures, so as to achieve the visual goals of comprehensive control of information, rapid rescue response and ensuring personal safety, and form an integrated natural disaster early warning system.
Research on the Rational Proportion of Housing Window in Shanghai Based on Ventilation Comfort
Authors: Wang Yueqiang , Luo Yulong , Zhou Jian
Published: June 2021

Taking the natural ventilation process of residential buildings in Shanghai in summer as research samples, this paper aims to obtain a reasonable range of window ratio by comparing the different scenario simulations by using Thsware VENT software. The research method was to simulate ventilation process of a room with rectangular windows in the same position in order to obtain the parameters of indoor wind environment under 12 window ratios circumstances. Through quantitative comparative analysis, the results showed that the ventilation parameters change regularly with the increase of the aspect ratio of windows. Moreover, the indoor natural ventilation comfort is best when the aspect ratio equals 2.0-2.76.
Study on the Composite Structure Type of Concrete Wall - Rockfill Dam
Authors: Zhou Heng , Lu Xi , Jing Liu , Di Shengjie , Huang Peng
Published: June 2021

This paper focuses on the proposed new structure type of “concrete wall - rockfill dam combination structure”, through the comparison of the downstream slope ratio of concrete wall, contact mode with rockfill body, contact mode with bedrock, wall height and other parameters, and the comparison with conventional rockfill dam structure, this paper provides a reference for the selection of the combined structure type. This new type can greatly improve the stress state of the panel rockfill dam, and effectively enhance the maintainability of the panel rockfill dam, partially solve the current problems of the panel rockfill dam, and can be popularized and applied.
Alignment Design of Underground Road: A Simulator Study
Authors: Chen Wei , Zhao Qian , Peng Weiyuan , Di Shengde , Sun Chuanjiao , Guo Da
Published: June 2021

In order to study the linear combination design method of underground roads, a road model with 16 test sections was designed for 8 common horizontal and vertical line combinations, and two test environments, up and under ground, were built. Fifteen participants participated in the driving simulation experiment. Driving behaviors between different lanes of roads on-ground and underground roads of each test section, each section with up or down slopes and with left or right turns were compared and analyzed. Then the applicability of different horizontal and vertical line combination in underground road design was evaluated.
Study on the position of load box for pile foundation of Qilu Yellow River Approach Bridge
Authors: Dong Pingsheng , Wang Xiang , Wang Hu
Published: June 2021

In theory, the balance point position of O-cell pile test is determined and unique, and the load box should be located at this point. But in practical projects, it is difficult to determine the balance point position accurately. The pile foundation of Qilu Yellow River Approach Bridge bears a large load. In order to reduce the risk caused by the position of load box in O-cell pile test, the double load box technology is adopted in this pile test project. According to the pile design, the soil properties and the loading sequence, the bearing capacity of the pile foundation before and after grouting is estimated. The pile test results show that the project is a successful example for the double load box technology.
Experimental study of three-dimensional photogrammetry technique in the observation of qiantang tidal bore’s height
Authors: Huang Xiaoya , Zheng Jian
Published: June 2021

In this paper, the three-dimensional photogrammetry is introduced in the tidal bore height observation of Yanguan station for the thread-shape bore near the Qiantang River estuary. The three-dimensional scene of the tidal bore is restored by remote control and post-solution. The measurement of tidal bore’s height in three-dimensional environment is realized, and the auxiliary measurement of tidal bore’s upper bound, the foot line, the tidal curve and other vector data are extracted. The accuracy of the measurement is compared with the result of the tidal bore height measured by the Water gauge observations on the same station. The results show that not only the tidal bore’s shape can be captured but also the tidal bore’s height can be quantitatively calculated by three-dimensional photogrammetry. The three-dimensional photogrammetry can be used to quantitatively observe the tidal bore’s height in Qiantang River Estuary and the measurement accuracy is reliable.
Study on Mix Proportion Design and Compressive Strength of Environment-Friendly Three-Admixture Concrete
Authors: Tuo Zijie , Jin Zhengchao , Song Yuhao , Li Chao , Fang Guangxiu
Published: June 2021

In this paper, the environment-friendly three-admixture concrete was prepared by using straw powder (rice husk powder) to replace cement by 6% and 8%, silicon powder by 10% and fly ash by 20%, respectively, and the effects of straw powder (rice husk powder), silicon powder and fly ash on the compressive strength of concrete were studied. Through the comparative analysis of the compressive strength of 9 groups three-mixed concrete blocks, the compressive strength of concrete reached the highest when the content of straw powder (rice husk powder) was 6%. On the basis of the current mix design formula of ordinary concrete, the strength formula of environment-friendly three-mixed concrete with correction coefficient was given, and the optimum substitution amount of straw powder (rice husk powder) was put forward.
Discussion for transitional material’s compaction construction technique of faced rockfill dam of one hydro-junction project
Authors: Tan Fengyi , Hu Lin , Tang Desheng
Published: June 2021

The transitional material zone was between the cushion material zone and the sandy gravel zone in the Faced Rockfill Dam of one Hydro-junction Project, which was from the C3 material yard with the diameter of less than 150.00 mm. By the in situ compaction tests of transitional material, its construction technique and parameters were obtained. Study showed that: its relative density was satisfied with the designed requirement (no less than 0.90) when it was compacted 8 times by the 26.0t self-propelled vibration roller at the speed of 2.0km/h on the conditions including the 20.0cm layout layer and the 5.0% water sprinkled content. Then there were series of compaction tests under the low temperature in winter. The study results was guided for the compaction construction of transitional material in the dam and was as the reference as the similar engineering.
Model test on bearing capacity characteristics of energy piles in saturated clay
Authors: Zhu W L , Chang H , Zhao S Y
Published: June 2021

Based on model tests, the load transfer mechanism of energy piles in saturated clay was studied, and the variation rules of pile and soil temperature, pile tip displacement, pile tip resistance, pile stress and lateral friction resistance were analyzed. The results show that the pile temperature decreases from top to bottom while the soil temperature decreases from the pile center to the radial direction. Under zero load, the pile expands by heat, and the pile top has a large upward displacement. Thermal consolidation of soil, settlement of soil surface and negative lateral friction occur under the alternating action of cooling and heating loads. Under working load, after applying cooling and heating load, the pile will produce unrecoverable accumulative settlement.
Application Research of BIM Technology in Ancient Architecture Restoration
Authors: Liu Yu-Jie , Li Wei , Li Yun-Han , Li Si-Jie
Published: June 2021

At present, the history of Chinese ancient architecture has a long history and independent development. As early as The Shang Dynasty, Chinese architectural system has been initially formed. Until the beginning of the 20th century, it has always maintained its own structure and layout principles, and has been widely spread to other countries. BIM Technology is a rapidly rising digital modeling technology in recent years, which is widely used in the construction industry. Its intuition and accuracy have become the advantages of its rapid development. At the same time, BIM Technology can also better protect ancient buildings from the perspective of information. Starting from the ancient building restoration industry, this paper analyzes the current development trend of the domestic ancient building industry, and summarizes the key problems existing in the existing ancient building restoration methods. This paper analyzes and discusses the advantages and functions of BIM technology. According to the example of the old office building of Fengtian Zhaoxin Kiln Company, a BIM model is established. Starting from the application of BIM technology in survey and design, construction process management and repair of special parts, the actual application of BIM technology in ancient building repair is discussed, and valuable results are obtained.
Research on Application of Soft Decoration Materials in Indoor Environmental Art Design
Authors: Zhang Yanxia
Published: June 2021

In recent years, with the continuous development of economy, people’s living standards have been continuously improved, urbanization has become more and more perfect, and requirements for indoor environmental art design have become higher and higher. The requirements for interior decoration have changed from the original decoration materials to be strong and durable to the modern decoration which is mainly beautiful and comfortable. Soft decoration materials play a vital role, because indoor soft decoration materials are the most important factor in determining the interior decoration style factor. In the decoration market at this stage, there is a saying that light decoration is heavy decoration, which shows the importance of soft decoration in indoor environmental art.
The influence of consumer’s “new demand” on commercial building design
Authors: Li Bing , Yang Xiaofan
Published: June 2021

With the continuous development of the society, the business environment has changed, and consumers’ consumption concepts have been updated, and consumers are in pursuit of efficient and diversified commercial space experience. Traditional commercial buildings are difficult to meet the new needs of people, and new materials and new technologies emerge in an endless stream to meet the needs of architectural development. This puts forward higher requirements to the design of commercial buildings. At present, new space in commercial buildings has emerged, and more architectural technologies have been applied in commercial buildings. Commercial space is constantly changing and reconstructing with the development of The Times and the needs of consumers.
Theoretical study on fatigue cumulative damage model of nanometer concrete
Authors: Li Wei , Xiong Long , Wang Xiaochu , Liuyujie
Published: June 2021

In order to follow-up nano concrete freeze-thaw damage model can have a solid theoretical foundation, this paper elaborates the concrete damage theory and fatigue damage model, and analyzes the characteristic and law of development of concrete fatigue cumulative damage, in order to fully understand the deteriorating law of the fatigue damage of concrete freezing and thawing, guide the establishment of concrete freeze-thaw damage model.
Preparation and mechanic properties of multi-wall carbon nanotube reinforced alumina matrix composites by spray drying and hot-pressing sintering
Authors: Tan Songlin , Zhuang Yongqi , Yi Jianhong
Published: June 2021

The multi-wall carbon nanotube (MWCNT) reinforced alumina (Al2O3) matrix composites were fabricated by spray drying and vacuum hot-pressing sintering. The mechanical properties of the composites with different mass fractions of MWCNT were studied. The flexural strength and fracture toughness of the composite were 498.3 MPa and 5.69 MPa·m 1/2, respectively, which were about 55.3% and 84.7% higher than that of pure Al2O3. With the increase in the content of MWCNT, the Vickers hardness and relative density of the composite decreased gradually. The correlation between the microstructure and the mechanical properties of the composite was analyzed.
The formation of sigma phase in the CoCrFeNi high-entropy alloys
Authors: Wang X J , Xu M , Liu N , Liu L X
Published: June 2021

The as-cast CoCrFeNi high-entropy alloys show simple FCC structure and outstanding deformation ability at room temperature. Respectively, after 50% of deforming at room temperature and annealing at intermediate temperature range of 600 °C–800 °C for 2 h, CoCrFeNi alloys still show simple-phase FCC structure. It is noteworthy that CoCrFeNi high-entropy alloys can’t be strengthened by means of annealing, while deformation is an effective way to strengthen the alloys. It is investigated that the formation of sigma (σ) phase in high-entropy alloys is closely related to the difference of atomic radius (δ), the concentration of valence electron (VEC) and paired sigma-forming element (PSFE) content, and PSFE plays an crucial role. When PSFE > 40 at.%, 6.75 ≤ VEC ≤ 7.86, 4.0 ≤ δ ≤ 7.2, σ phase is prone to form in high-entropy alloys. In addition, alloying and processing route are two important factors that affect the sigma-formation in CoCrFeNi high-entropy alloys.
Neurogrid simulates cortical cell-types, active dendrites, and top-down attention
Authors: Benjamin Ben Varkey , Steinmetz Nicholas A , Oza Nick N , Aguayo Jose J , Boahen Kwabena
Published: June 2021

A central challenge for systems neuroscience and artificial intelligence is to understand how cognitive behaviors arise from large, highly interconnected networks of neurons. Digital simulation is linking cognitive behavior to neural activity to bridge this gap in our understanding at great expense in time and electricity. A hybrid analog–digital approach, whereby slow analog circuits, operating in parallel, emulate graded integration of synaptic currents by dendrites while a fast digital bus, operating serially, emulates all-or-none transmission of action potentials by axons, may improve simulation efficacy. Due to the latter’s serial operation, this approach has not scaled beyond millions of synaptic connections (per bus). This limit was broken by following design principles the neocortex uses to minimize its wiring. The resulting hybrid analog–digital platform, Neurogrid, scales to billions of synaptic connections, between up to a million neurons, and simulates cortical models in real-time using a few watts of electricity. Here, we demonstrate that Neurogrid simulates cortical models spanning five levels of experimental investigation: biophysical, dendritic, neuronal, columnar, and area. Bridging these five levels with Neurogrid revealed a novel way active dendrites could mediate top-down attention.
From smart city to digital urban commons: Institutional considerations for governing shared mobility data
Authors: Creutzig Felix
Published: June 2021

Smart and shared mobility, from e-scooters to pool-riding services, reshape mobility in cities worldwide. While there is wide scope for new business opportunity in mobility, administrations remain unclear of how to manage and organize shared mobility and the big data underpinning shared mobility to serve the public good, in particular by reducing congestion and greenhouse gas emissions. Here, we suggest that management of smart mobility data constitutes a new layer of urban infrastructure that is integral to reaching sustainability goals. We investigate how integrated data management can realize the benefits of big data applications, while effectively managing risks, exemplifying our argument for the case of shared mobility in Israel. We argue that shared mobility and associated data management is neither necessary nor sufficient condition for sustainable mobility. However, given the current trend towards digitalization, data rentiership and surveillance capitalism, we suggest that institutionalizing data management of smart and shared mobility as a public good is a wise move that protects mobility users and facilitates efforts to steer shared mobility systems to low-carbon, low-congestion, and inclusive mobility. We develop a typology of six data platforms and find that integrated data platforms offer an opportunity to leverage benefits if three key design principles are followed: (1) open (but not necessarily free) data access; (2) maintaining the privacy, agency and participation of individuals, users, and the public; and (3) tailoring mobility services to meet well-defined goals of public policy.
Psilocybin Induces Aberrant Prediction Error Processing of Tactile Mismatch Responses—A Simultaneous EEG–FMRI Study
Authors: Duerler Patricia , Brem Silvia , Fraga-González Gorka , Neef Tiffany , Allen Micah , Zeidman Peter , Stämpfli Philipp , Vollenweider Franz X , Preller Katrin H
Published: June 2021

As source of sensory information, the body provides a sense of agency and self/non-self-discrimination. The integration of bodily states and sensory inputs with prior beliefs has been linked to the generation of bodily self-consciousness. The ability to detect surprising tactile stimuli is essential for the survival of an organism and for the formation of mental body representations. Despite the relevance for a variety of psychiatric disorders characterized by altered body and self-perception, the neurobiology of these processes is poorly understood. We therefore investigated the effect of psilocybin (Psi), known to induce alterations in self-experience, on tactile mismatch responses by combining pharmacological manipulations with simultaneous electroencephalography–functional magnetic resonance imaging (EEG–fMRI) recording. Psi reduced activity in response to tactile surprising stimuli in frontal regions, the visual cortex, and the cerebellum. Furthermore, Psi reduced tactile mismatch negativity EEG responses at frontal electrodes, associated with alterations of body- and self-experience. This study provides first evidence that Psi alters the integration of tactile sensory inputs through aberrant prediction error processing and highlights the importance of the 5-HT2A system in tactile deviancy processing as well as in the integration of bodily and self-related stimuli. These findings may have important implications for the treatment of psychiatric disorders characterized by aberrant bodily self-awareness.
Folic Acid Inhibits Aging-Induced Telomere Attrition and Apoptosis in Astrocytes In Vivo and In Vitro
Authors: Li Zhenshu , Zhou Dezheng , Zhang Dalong , Zhao Jing , Li Wen , Sun Yue , Chen Yongjie , Liu Huan , Wilson John X , Qian Zhiyong , Huang Guowei
Published: June 2021

Folic acid (FA) has been reported to inhibit astrocyte apoptosis and improve aging-induced disorders; however, its role in telomere attrition remains unclear. In present study, 4-month-old senescence-accelerated mouse prone 8 (SAMP8) mice were assigned to four treatment groups for the in vivo experiment: FA-deficient diet (FA-D) group, FA-normal diet (FA-N) group, low FA-supplemented diet (FA-L) group, and high FA-supplemented diet (FA-H) group. These mice were euthanized when 10 months old. There was also a young SAMP8 (4 months old) control group (Con-Y) fed with FA-normal diet. In in vitro study, primary cultures of astrocytes from hippocampus and cerebral cortex were incubated for five generations with various concentrations of FA (0–40 μM) and were assigned to five groups: FA 0 μM (generation 5), FA 10 μM (generation 5), FA 20 μM (generation 5), FA 40 μM (generation 5), and FA 10 μM (generation 1). The results showed that FA supplementation inhibited aging-induced astrocytosis, astrocyte apoptosis, neurodegeneration, and prevented telomere attrition in hippocampus and cortex of SAMP8 mice. FA supplementation also decreased apoptosis and telomere attrition, and increased telomerase activity, in primary cultures of astrocytes. These results showed that it may be one of the mechanisms that FA inhibiting aging-induced apoptosis of astrocyte by alleviating telomere attrition.
The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) mRNA Vaccine-Breakthrough Infection Phenotype Includes Significant Symptoms, Live Virus Shedding, and Viral Genetic Diversity
Authors: Pollett Simon D , Richard Stephanie A , Fries Anthony C , Simons Mark P , Mende Katrin , Lalani Tahaniyat , Lee Tida , Chi Sharon , Mody Rupal , Madar Cristian , Ganesan Anuradha , Larson Derek T , Colombo Christopher J , Colombo Rhonda , Samuels Emily C , Broder Christopher C , Laing Eric D , Smith Darci R , Tribble David , Agan Brian K , Burgess Timothy H
Published: June 2021

Little is known about severe acute respiratory syndrome coronavirus 2 “vaccine-breakthrough” infections (VBIs). Here we characterize 24 VBIs in predominantly young healthy persons. While none required hospitalization, a proportion endorsed severe symptoms and shed live virus as high as 4.13 × 103 plaque-forming units/mL. Infecting genotypes included both variant-of-concern (VOC) and non-VOC strains.
Dehydration risk is associated with reduced nest attendance and hatching success in a cooperatively breeding bird, the southern pied babbler Turdoides bicolor
Authors: Bourne Amanda R , Ridley Amanda R , McKechnie Andrew E , Spottiswoode Claire N , Cunningham Susan J
Published: June 2021

High air temperatures have measurable negative impacts on reproduction in wild animal populations, including during incubation in birds. Understanding the mechanisms driving these impacts requires comprehensive knowledge of animal physiology and behaviour under natural conditions. We used a novel combination of a non-invasive doubly labelled water (DLW) technique, nest temperature data and field-based behaviour observations to test effects of temperature, rainfall and group size on physiology and behaviour during incubation in southern pied babblers Turdoides bicolor, a cooperatively breeding passerine endemic to the arid savanna regions of southern Africa. The proportion of time that clutches were incubated declined as air temperatures increased, a behavioural pattern traditionally interpreted as a benefit of ambient incubation. However, we show that (i) clutches had a <50% chance of hatching when exposed to daily maximum air temperatures of >35.3°C; (ii) pied babbler groups incubated their nests almost constantly (99% of daylight hours) except on hot days; (iii) operative temperatures in unattended nests frequently exceeded 40.5°C, above which bird embryos are at risk of death; (iv) pied babblers incubating for long periods of time failed to maintain water balance on hot days; and (v) pied babblers from incubating groups lost mass on hot days. These results suggest that pied babblers might leave their nests during hot periods to lower the risk of dehydration associated with prolonged incubation at high operative temperatures. As mean air temperatures increase and extreme heat events become more frequent under climate change, birds will likely incur ever greater thermoregulatory costs of incubation, leading to compromised nest attendance and increased potential for eggs to overheat, with implications for nest success and, ultimately, population persistence.
Left ventricular longitudinal strain alterations in asymptomatic or mildly symptomatic paediatric patients with SARS-CoV-2 infection
Authors: Sirico Domenico , Di Chiara Costanza , Costenaro Paola , Bonfante Francesco , Cozzani Sandra , Plebani Mario , Reffo Elena , Castaldi Biagio , Donà Daniele , Da Dalt Liviana , Giaquinto Carlo , Di Salvo Giovanni
Published: June 2021

Aims

Compared with adult patients, clinical manifestations of children’s coronavirus disease-2019 (COVID-19) are generally perceived as less severe. The objective of this study was to evaluate cardiac involvement in previously healthy children with asymptomatic or mildly symptomatic severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection.

Methods and results

We analysed a cohort of 53 paediatric patients (29 males, 55%), mean age 7.5 ± 4.7 years, who had a confirmed diagnosis of SARS-CoV-2 infection and were asymptomatic or only mildly symptomatic for COVID-19. Patients underwent standard transthoracic echocardiogram and speckle tracking echocardiographic study at least 3 months after diagnosis. Thirty-two age, sex, and body surface area comparable healthy subjects were used as control group. Left ventricular ejection fraction was within normal limits but significantly lower in the cases group compared to controls (62.4 ± 4.1% vs. 65.2 ± 5.5%; P = 0.012). Tricuspid annular plane systolic excursion (20.1 ± 3 mm vs. 19.8 ± 3.4 mm; P = 0.822) and left ventricular (LV) global longitudinal strain (−21.9 ± 2.4% vs. −22.6 ± 2.5%; P = 0.208) were comparable between the two groups. Regional LV strain analysis showed a significant reduction of the LV mid-wall segments strain among cases compared to controls. Furthermore, in the cases group, there were 14 subjects (26%) with a regional peak systolic strain below −16% (−2.5 Z score in our healthy cohort) in at least two segments. These subjects did not show any difference regarding symptoms or serological findings.

Conclusion

SARS-CoV-2 infection may affect left ventricular deformation in 26% of children despite an asymptomatic or only mildly symptomatic acute illness. A follow-up is needed to verify the reversibility of these alterations and their impact on long-term outcomes.
Poor adherence to lifestyle recommendations in patients with coronary heart disease: results from the EUROASPIRE surveys
Authors: De Bacquer Dirk , Astin Felicity , Kotseva Kornelia , Pogosova Nana , De Smedt Delphine , De Backer Guy , Rydén Lars , Wood David , Jennings Catriona ,   for the EUROASPIRE IV and V surveys of the European Observational Research Programme of the European Society of Cardiology
Published: June 2021

Aims 

Despite the high use of cardioprotective medications, the risk factor control in patients with coronary heart disease (CHD) is still inadequate. Guidelines identify healthy lifestyles as equally important in secondary prevention as pharmacotherapy. Here, we describe reasons for poor lifestyle adherence from the patient’s perspective.

Methods and results 

In the EUROASPIRE IV and V surveys, 16 259 CHD patients were examined and interviewed during a study visit ≥6 months after hospital discharge. Data gathering was fully standardized. The Brief Illness Perception questionnaire was completed by a subsample of 2379 patients. Half of those who were smoking prior to hospital admission, were still smoking; 37% of current smokers had not attempted to quit and 51% was not considering to do so. The prevalence of obesity was 38%. Half of obese patients tried to lose weight in the past month and 61% considered weight loss in the following month. In relation to physical activity, 40% was on target with half of patients trying to do more everyday activities. Less than half had the intention to engage in planned exercise. Only 29% of all patients was at goal for all three lifestyle factors. The number of adverse lifestyles was strongly related to the way patients perceive their illness as threatening. Lifestyle modifications were more successful in those having participated in a cardiac rehabilitation and prevention programme. Patients indicated lack of self-confidence as the main barrier to change their unhealthy behaviour.

Conclusion 

Modern secondary prevention programmes should target behavioural change in all patients with adverse lifestyles.
The Dryas iulia Genome Supports Multiple Gains of a W Chromosome from a B Chromosome in Butterflies
Authors: Lewis James J , Cicconardi Francesco , Martin Simon H , Reed Robert D , Danko Charles G , Montgomery Stephen H
Published: June 2021

In butterflies and moths, which exhibit highly variable sex determination mechanisms, the homogametic Z chromosome is deeply conserved and is featured in many genome assemblies. The evolution and origin of the female W sex chromosome, however, remains mostly unknown. Previous studies have proposed that a ZZ/Z0 sex determination system is ancestral to Lepidoptera, and that W chromosomes may originate from sex-linked B chromosomes. Here, we sequence and assemble the female Dryas iulia genome into 32 highly contiguous ordered and oriented chromosomes, including the Z and W sex chromosomes. We then use sex-specific Hi-C, ATAC-seq, PRO-seq, and whole-genome DNA sequence data sets to test if features of the D. iulia W chromosome are consistent with a hypothesized B chromosome origin. We show that the putative W chromosome displays female-associated DNA sequence, gene expression, and chromatin accessibility to confirm the sex-linked function of the W sequence. In contrast with expectations from studies of homologous sex chromosomes, highly repetitive DNA content on the W chromosome, the sole presence of domesticated repetitive elements in functional DNA, and lack of sequence homology with the Z chromosome or autosomes is most consistent with a B chromosome origin for the W, although it remains challenging to rule out extensive sequence divergence. Synteny analysis of the D. iulia W chromosome with other female lepidopteran genome assemblies shows no homology between W chromosomes and suggests multiple, independent origins of the W chromosome from a B chromosome likely occurred in butterflies.
Exploring the Sustainability of Age-Friendly Initiatives in a Canadian Province
Authors: Menec Verena H , Newall Nancy E G , Milgrom Richard , Camps Dominique
Published: June 2021

Background and Objectives

Based on the World Health Organization Age-Friendly Cities and Communities (AFCC) framework, the government of Manitoba, Canada, launched a province-wide age-friendly initiative in 2008. The objective of this study was to explore the sustainability of the AFCC initiative more than a decade later. The study was guided by conceptualizations of sustainability as multidimensional and dynamic, composed of 4 aspects (continued capacity, institutionalization, continued benefits, and development/adaptation), and an ecologic perspective that highlights the importance of contextual influences, and their change over time, on AFCC activities.

Research Design and Methods

The study involved a qualitative, multiple case study design. Semistructured interviews were conducted in 2020 with a key informant from each of 52 AFCC. Interview data were analyzed deductively, guided by the sustainability framework and an ecologic perspective. Census data were used to describe the demographic characteristics of AFCC.

Results

We identified 6 groups of AFCC initiatives that varied in degree from the most to the least sustainable: active, in hiatus, reorganized, stalled, discontinued, and never got off the ground. Both local community factors (e.g., lack of capacity) and broader contextual factors, such as demographic changes and provincial legislations, influenced initiatives’ sustainability.

Discussion and Implications

AFCC initiatives can range in their degree of sustainability and can wax or wane over time. Ongoing external support for AFCC (e.g., from provincial or state government) to promote the vision of age-friendliness and to address lack of capacity (e.g., to assist with community assessments) could help with the long-term sustainability of initiatives.