bluuebunny/crossref_metadata_2025 huggingface dataset:
Planning exploration of the transition from “waste landfill” to “circular economy industrial park”-Take Guangzhou Xingfeng Domestic Waste Landfill Site Closure and Reconstruction Plan as an Example
Authors: Wenhong Li , Ridong Yu , Jiayi Lin
Published: March 2021

Under the background of high-level protection of the ecological environment and the promotion of economic “green recovery” and high-quality development after the epidemic, we will do a good job in the “14th Five-Year” ecological environment protection work, correctly handle the relationship between development and protection, and develop an environmental protection culture. It will definitely become the main line of work during the “14th Five-Year Plan” period. This article takes the closure and renovation plan of the Xingfeng domestic waste landfill in Guangzhou as an example, studies and draws on successful cases at home and abroad, and explores the planning and design of the renovation of the landfill after the closure, combined with the domestic waste landfill Advanced waste treatment technology and the unique natural ecological environment of Jinkeng National Forest Park will transform the Guangzhou Xingfeng Domestic Waste Landfill into a circular economy industrial park with the function of ecological recycling of domestic waste. This transformation plan can guide the public to actively participate in the environment. Cultural construction is of great significance to the construction of ecological civilization; at the same time, it is also an exploration of green recycling, low-carbon, and sustainable planning methods.
Integration of regional culture and place environment——Taking the landscape sculpture design scheme of Yuanbaozi Wetland Park as an example
Authors: Ma Jie , Li Yi , Shen Duwen , Zhang Ran
Published: March 2021

In order to create a good cultural atmosphere and environmental characteristics, improve the overall quality, promote the integration of public life into the modern city, and enhance the local artistic charm and taste of life, the creators integrated the regional culture and the unique environment of the place in the sculpture design concept scheme of yuanbaozi wetland park with the sense of modernity, interactivity and regionality. Taking “mountain” and “water” as the main idea, human history as the key link and integrating local elements can not only continue the context, but also reflect the unique local characteristics, and then integrate with the park landscape layout and style to realize the beauty of diversity and unity.
Investigation and Analysis on Current Management of Small and Medium-sized Rivers in Shandong Province
Authors: Jing Huilin , Tian Xi , Lu Xiayi , Cheng Xia , Zhu Shicheng , Zhou Shupeng
Published: March 2021

2020 is the last year of the 13th Five-Year Plan, and also the final year of building a well-off society in an all-round way. During the 13th Five-Year Plan, small and medium-sized rivers in this province have experienced large-scale treatment, playing an essential role in flood control and drainage, agricultural irrigation, disaster prevention and mitigation, and improvement of river ecological environment in addition to improving the currently weak water-conservancy infrastructure. However, local government still have problems in funding, land acquisition, segment-based management and treatment, project maintenance, and the balance between flood control and eco-system. Therefore, it is necessary to take effective measures and give the small and medium-sized rivers a greater role in flood control, drainage and eco-system apart from increasing investment in these fields.
Effect of evaporation on land salinization after storm surge overtopping embankment
Authors: Lu Hong
Published: March 2021

Based on SUTRA, a numerical simulation software of groundwater with variable saturation and density, the influence of evaporation after storm surge on soil pore water flow and salt transport process was studied. The results showed that the seawater overtopping caused land soil salinization, and evaporation would weaken the vertical infiltration of salt water, keep salt in the shallow soil, and increase the salt content in the shallow soil, which made it difficult to eliminate soil salinization.
Study on seismic and shock absorption performance of Yi Ci Hui stone pillar
Authors: Xiaowei Yang , Yanfeng Wang
Published: March 2021

The rigid block structure composed of multiple blocks of stones will sway during an earthquake. The rocking and rocking impact dissipates the seismic force and has good shock absorption performance. The seismic and seismic performance of Yi Ci Hui stone pillar with multi-layer block stones was studied. The results showed that: only the acceleration increases to a certain value, the rocking amplitude of the multi-layer stacked stone pillar occurs; with the continuous increase of the earthquake acceleration, the rocking amplitude of the stone pillar will rapidly decay or even be stationary. Stacking stone pillar can effectively take advantage of high compressive strength of block stone, and only produce compressive stress in the pillar root section to avoid stress failure of stone pillar. The energy reaction of the multi-layer stone pillar is mainly kinetic energy, which reaches the maximum when the stone pillar begins to shake, and then decreases rapidly. The total strain energy reaches the peak value when the stone pillar shakes, and then remains unchanged. The rocking and shaking of stacked stone pillars causes the impact of rock interface edge to dissipate seismic energy, which makes the rocking amplitude and kinetic energy of stone pillar gradually decrease, and the total strain energy is basically unchanged, which effectively plays the role of seismic shock absorption.
Experimental Verification on Finite Element Model of Composite Columns with Concrete Filled Steel Tube Flange
Authors: Ji Jing , Jiang Li , Jiang Liangqin , Song Huayu
Published: March 2021

In order to study mechanical performance of composite columns with concrete-filled steel tube flange subjected to the eccentric compression, the finite element model of this kind of composite columns is established by using ABAQUS finite element software. In this paper, the reasonable material constitutive and finite element modelling method are selected to carry out numerical simulation analysis of concrete-filled steel tubular composite columns and concrete-filled square steel tubular columns. The load vertical displacement curves, load lateral deflection curves and failure modes are obtained, which are in good agreement with the existing test data. The rationality of material constitutive and finite element modelling is verified, which lays a foundation for further establishing the calculation formula of eccentric compression bearing capacity of this kind of column.
Study on the preparation and properties of new sleeve grouting material for prefabricated building
Authors: Peng Hong , Liu Lijun
Published: March 2021

The control variable method was used to determine the reasonable amount of cementitious system, water reducing agent and early strength agent in the grouting material. Through orthogonal test, the effect of water-binder ratio, cement-sand ratio and desulfurized building gypsum content on the fluidity, compressive strength and vertical expansion rate of grouting material was studied. The experiment determined the optimal ratio of grouting material. The test results show that the main factor affecting the fluidity of grouting material is the cement-sand ratio; the main factor affecting the 1d and 3d compressive strength is the gypsum, and the main factor of the 28d compressive strength is the water-binder ratio; the main factor affecting the vertical expansion rate of 3h and 24h is the gypsum content. The optimal ratio of grouting material is: water-binder ratio of 0.23, cement-sand ratio of 1.0, the mass ratio of cement to mineral admixture is 4:1, polycarboxylate superplasticizer of 0.3%, calcium formate early strength agent of 0.7%, silicone defoamer of 0.2%, desulfurized building gypsum of 9%.
Study on hydrodynamic properties of a common building material
Authors: Yifei Wang , Mengyun Chu , Jingjian Li
Published: March 2021

The efficient self-leveling ability of self-compacting concrete is widely used in various industries and structures, but the influence mechanism and law on its flow performance have not been quantified, so it is urgent to find a suitable explanation method. Water film thickness is considered to be one of the key factors affecting the flow performance of mortar and cement paste, but there is a lack of research in concrete. In this paper, relevant experimental studies are carried out based on the theoretical innovation of water film thickness. In order to further improve the flow performance of self-compacting concrete, according to a certain gradient, 24 fresh self-compacting concrete flow performance tests and filling density measurement tests were carried out to observe the relationship between water film thickness and concrete flow performance. The results show that there is a strong correlation between the flow performance of concrete and the thickness of water film, and there is a positive correlation between them. the addition of talc powder can improve the flow performance of self-compacting concrete, and the flow performance is the best when 5% talc powder is added to replace cement.
Calculation method of stiffness of partially fabricated steel reinforced concrete beams
Authors: Yong Yang , Yanni Cao , Yicong Xue , Yunlong Yu
Published: March 2021

In this paper, two new types of partially precast steel reinforced concrete beams are proposed by combining the advantages of steel reinforced concrete beams, high strength concrete beams and precast assembly structures. Partially fabricated steel reinforced concrete beams are composed of precast high-strength concrete shell and cast-in-place concrete core area. In order to further reduce the dead weight of the members, partially fabricated steel concrete beam sections are hollow or can be filled with thermal insulation materials. In this paper, by using the superposition method and based on the existing test results, two new stiffness calculation methods for partially prefabricated SRC beams are proposed.
Research on earth pressure monitoring data of soil-stone assorted foundation pit
Authors: Quanming Zheng , Junyan Liu , Yan Liu , Donglin He , Yang Wang , Xiaodong Feng , Xiwen Zhang
Published: March 2021

Earth pressure is the most important type of load acting on the supporting structure of a foundation pit, and it is also a key factor in the design of foundation pit supporting. However, in engineering practice, the calculated value differs greatly from the actual value, which puzzles many engineers. This paper analyzes the field measured data of the earth pressure of the foundation pit in Minghucheng (Jinan city), and compares the calculated values of the Rankine active earth pressure and the passive earth pressure theory. The analysis finds that: (1) The measured value is between the active earth pressure and the passive earth pressure, and as the excavation of the foundation pit and the inward displacement of the supporting structure, the measured earth pressure value becomes smaller and approaches the active earth pressure. (2) When the pre-stressed anchors is applied, due to the fastening effect of the anchors, the earth pressure behind the supporting pile has a tendency to increase. (3) The theoretical value of Rankine’s active earth pressure in the soil-rock combination is obviously lower than the measured values.
Monitoring System Design for Intelligent Hydraulic Safety Based on the IoT
Authors: Wenfeng Ma , Haiyin Jin , Zhangyu Pan , Qi LinG , Jianhua Deng
Published: March 2021

In order to improve the safety operation management of hydraulic structures in hydropower stations, this paper analyzes the status and shortcomings of hydraulic safety monitoring automation system, and puts forward the design idea and scheme based on IoT. The intelligent connection of hydraulic monitoring equipment is realized by optimizing the design of sensing collection, communication network, monitoring application and information security of the system. By coordinating the monitoring, configuration and management of each monitoring terminal equipment, and using cloud computing technology to calculate, analyze and evaluate the monitoring data in real time, the intelligent online monitoring of hydraulic structures is realized, so as to ensure the safe and efficient operation of hydropower station infrastructure.
Finite Element Analysis of Deformation Effect of Concrete Filled Steel Tubular Composite Frame under High Temperature
Authors: Li Yucheng , Wang Wei , Wang Xing
Published: March 2021

The research on the mechanical characteristics of concrete-filled steel tubular composite frame under high temperature is one of the hot topics. In this paper, through the finite element simulation software, the failure characteristics of the deformation of concrete-filled steel tubular composite frame and the simulation results of the deformation effect of concrete-filled steel tubular composite frame structure are analyzed, including the effect of each component in different temperature fields, different structural fields and various coupling fields, the redistribution and change of the local plastic region of the component under high temperature, and the change of the local plastic region of the component under high temperature. The comparative analysis of the flexural effect of two-story two span concrete-filled steel tubular composite frame under different fire positions shows that: with the rising of fire time, the vertical displacement is also increasing, the scope of local plastic area is expanding, the deflection redistribution is obvious, and finally the mechanism is formed, and the failure occurs. The deformation effect of condition 1 changes more than that of condition 2, which indicates that the two-story two span steel tubular composite frame has a large deformation effect. The fire resistance of concrete-filled tubular composite frame is better under the condition of full section fire. The research results can provide reference value for strengthening and repairing of concrete-filled steel tubular composite frame under high temperature.
Study on tensile mechanical properties of polymer cement composite joint sealant under negative temperature
Authors: Wang Zhihang , Xu Jinyu , Meng Xin , Huang Zhe , Xia Wei
Published: March 2021

Tensile tests were carried out on polymer cement composite joint sealant(PCJS) after different negative temperature action time. By testing the tensile strength index, tensile deformation index and tensile energy consumption index of PCJS, the effect of negative temperature action time on the tensile mechanical properties of PCJS was studied. The results show that with the extension of the negative temperature, the tensile strength of PCJS continues to increase, the tensile elongation at break and the tensile toughness first increase and then decrease, the tensile peak strain and the tensile pre-peak toughness keep decreasing. After 1 d of negative temperature, the tensile elongation at break and the tensile toughness of PCJS were the largest.
Analysis and Treatment of the Cracks on the Runner Blade of a Francis Turbine
Authors: Long Yuanlin
Published: March 2021

Aiming at the problem of repeated cracks in the runner of a power plant, this paper comprehensively analyzes and determines the causes of runner cracks in terms of runner design, operation, blade strength, resonance, and blade material, and then deals with them.
Feasibility study of the binary geopolymer as the dredged silt stabilizer
Authors: Shi Yupeng , Zhang Mo , Pan Zhu , Sanjayan Jay
Published: March 2021

With the increasing dredging activities, a large quantity of silt is removed from the bottom of waterbody and dumped on the landfill site, having the potential to cause a number of environmental issues. Given that dredged silt is the soft and weak soil, it is usually stabilized with ordinary Portland cement (OPC) and/or lime for application in construction. However, the production processes of traditional stabilizers are energy intensive and high CO2 emission. In this study, attempts are being made to find an alternative environmentally friendly stabilizer with a low carbon footprint using industrial by-products. Six mixtures were prepared and these mixes can be grouped into two series. Series I includes untreated soil (S), cement stabilized soil (CS), the binary geopolymer (alkali-activated slag-fly ash) stabilized soil (SFS) and the alkali-activated soil (AS). In series II, 18% sand (by the weight of total soil) was added to SFS and AS. The properties of stabilized soils were evaluated via unconfined compressive strength (UCS) test, scanning electron microscopy (SEM) imaging and X-ray diffractometer (XRD) test. The results showed the formation of geopolymer gel for both AS and SFS. The formation of sodium alumino silicate hydrate was also detected, which may result in higher strength of SFS, as compared to AS. The strength of SFS is similar to that of CS while the emission CO2-e values of SFS are 76% lower than that of CS, indicates the effectiveness of the binary geopolymer as an effective and green soil stabilizer alternative to OPC.
The Movement Track of the Ocean Current in Jiaozhou Bay
Authors: Yang Dongfang , Li Haixia , Wang Qi , Zhang Longlei , Lin Dong
Published: March 2021

According to the data on the investigation of Jiaozhou Bay in May, August and October, 1992, the Pb content and the horizontal distribution in the surface of Jiaozhou Bay were studied. The results show that in May, the open ocean current with a high content of Pb entered Jiaozhou Bay surrounding the nearshore waters of the bay. In August, in the waters of Jiaozhou Bay, there was only one high Pb content source - open ocean current transportation. The open ocean current entered Jiaozhou Bay with a high content of Pb. The ocean current passed from the outside of the bay to the inside through the bay mouth with 37.53 μg/L Pb content. Then the ocean current made a circle around the inshore waters of Jiaozhou Bay, bringing a high Pb content zone of 11.30 - 27.44 μg/L. At this point, a low Pb content area of 5.53 μg/L appeared in the central waters of Jiaozhou Bay. So, in August, the open ocean current with a high content of Pb moved into Jiaozhou Bay. Then it surrounded the nearshore waters of the bay. By the authors’ Dongfang Yang’s migration law of material content, it is obtained that the open ocean current with high Pb content moves into Jiaozhou Bay. And with the continuous decrease of Pb content, the flow path of the open ocean current in the bay, illustrated by a model block diagram, is left. Furthermore, the migration law reveals that the unit water body with the ocean current returns to the inlet water in a counterclockwise direction along the inshore water in the bay. Thus, under the combined action of ocean current and tide, this unit of water body shows zigzag movement from east to north and to west along the eastern, northern and western coastal waters of Jiaozhou Bay, leaving the center of the bay barely affected by the unit water. The unit body of water has a circular center in the center of the bay and a zigzag motion along the edges. Moreover, the topography and geomorphology of the bottom of Jiaozhou Bay also confirm the movement track of the ocean current in the waters of Jiaozhou Bay proposed by the authors.
Research on end location of 32m box girder in high-speed railway
Authors: Du Xiaorui
Published: March 2021

The creep camber of 32m high-speed railway box girder causes periodic track longitudinal level irregularity, so it is necessary to strictly and accurately control the line change caused by creep to ensure the operation safety. The traditional analysis is mainly done by manual work. Based on the longitudinal level data of dynamic track inspection, this paper uses wavelet decomposition and moving-average filter to study the end location of box girder. the longitudinal level at the girder’s end can be extracted and the line state can be analyzed automatically. The results show that: compared with other time-frequency analysis methods, the proposed method can accurately locate the end of the box girder, and has good applicability.
Research on Frost Heave of High Speed Railway in Seasonal Frozen Region Based on Track Geometry Measurements
Authors: Wang Xiang
Published: March 2021

The frost heave and thawing settlement in the seasonal frozen areas can cause the track geometry change, even seriously affect the driving safety. Taking the HSR-A railway as the research object, this paper divides the change process of track surface during the period of frost heave and thawing settlement into four stages, and equates the four stages into a trapezoidal change process. Then the characteristics of these stages are summarized. Finally, based on the track geometry measurements (TGM), two different linear functions are used to represent the track surface changes before and after frost heave start respectively, and this essay proposes the start time estimations model(STEM) to estimate the start time of frost heave. STEM is applied to 10 typical frost heave positions in the HSR-A. The results show: the estimated effect is good.
Field measurement, analysis and protection for the vibration response of granary ruins caused by train load
Authors: Ma Qingwen , Li Xingang , Cheng Chaoqun , Yan Haitao
Published: March 2021

In this paper, the vibration effect of Longhai Railway on a granary ruins is taken as the research object. Firstly, the vibration response of the granary ruins is obtained by field test. Then, using FLAC3D finite element analysis software to establish an overall calculation model, and the shock absorption effect of vibration isolation barrier is analyzed and predicted. The conclusions are as follows: the horizontal vibration of granary ruins is stronger than the vertical vibration; because of the special structure of the granary ruins, when the vibration propagates to the interface of the cellar wall, it will produce horizontal vibration amplification phenomenon, and the vibration intensity of the granary ruins away from the vibration source will decrease faster; discontinuous concrete isolation piles are used to protect granary ruins. Under the premise of considering more economical, double-row piles with staggered layout have the best vibration isolation effect.
Study on a 2D flow and sediment mathematical model for the reach where a bridge is located
Authors: Ge Hua , Deng Chunyan , Gong Ping
Published: March 2021

In order to evaluate the feasibility of constructing a bridge in the end of Ganjiang River, a two-dimensional mathematical model was established in this paper. In order to verify the reliability of the mathematical model, based on the water and sediment processes from 2013 to 2018, the riverbed erosion and deposition were calculated. According to the measured terrain in 2013 and 2018, the calculated amount and distribution of erosion and deposition were verified. The verification results show that the mathematical model established in this paper can better simulate the erosion and deposition amount and distribution of the river reach, which can provide a reliable technical support for the construction of bridges.
Experimental Research on Pressure Pulsation and Stability of Giant Francis Turbine
Authors: Geng Qinghua
Published: March 2021

Pressure pulsation is an important factor affecting the stability of the turbine. The test studied the characteristics and laws of pressure fluctuations of giant hydraulic turbines to provide guidance for the design and stable operation of giant hydraulic turbines. The test used time-domain analysis and frequency-domain analysis methods to test and analyze the pressure pulsating real machine of giant hydraulic turbine. The test results show that the amplitude of pressure pulsation has a negative correlation with active power. The active power ranges from no-load to 40%P, and the pressure pulsation is mainly expressed as a high-frequency waveform with a frequency conversion of 8.8 to 24.4 times. The active power ranges from 40%P to 75%P, and the pressure pulsation mainly manifests as a low-frequency waveform with a frequency conversion of 0.19 to 0.28 times. Active power range from 75%P to 100%P, the amplitude of pressure pulsation decreases significantly. The above three load areas coincide with the vibration area of the unit, indicating that the hydraulic factor is the main factor affecting the stability of the unit.
Surrounding the solution of a linear system of equations from all sides
Authors: Steinerberger Stefan
Published: March 2021

Suppose

A
∈

R

n
×
n

A \in \mathbb {R}^{n \times n}

is invertible and we are looking for the solution of

A
x
=
b

Ax = b

. Given an initial guess

x
1

∈

R

x_1 \in \mathbb {R}

, we show that by reflecting through hyperplanes generated by the rows of

A
A

, we can generate an infinite sequence

(

x
k

)

k
=
1

∞

(x_k)_{k=1}^{\infty }

such that all elements have the same distance to the solution

x
x

, i.e.

‖

x
k

−
x
‖
=
‖

x
1

−
x
‖

\|x_k - x\| = \|x_1 - x\|

. If the hyperplanes are chosen at random, averages over the sequence converge and
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="double-struck upper E double-vertical-bar x minus StartFraction 1 Over m EndFraction sigma-summation Underscript k equals 1 Overscript m Endscripts x Subscript k Baseline double-vertical-bar less-than-or-equal-to StartFraction 1 plus double-vertical-bar upper A double-vertical-bar Subscript upper F Baseline double-vertical-bar upper A Superscript negative 1 Baseline double-vertical-bar Over StartRoot m EndRoot EndFraction dot double-vertical-bar x minus x 1 double-vertical-bar period">

E

‖
x
−

1
m

∑

k
=
1

m

x
k

‖

≤

1
+
‖
A

‖
F

‖

A

−
1

‖

m

⋅
‖
x
−

x
1

‖
.

\begin{equation*} \mathbb {E} \left \| x - \frac {1}{m} \sum _{k=1}^{m}{ x_k} \right \| \leq \frac {1 + \|A\|_F \|A^{-1}\|}{\sqrt {m}} \cdot \|x-x_1\|. \end{equation*}

The bound does not depend on the dimension of the matrix. This introduces a purely geometric way of attacking the problem: are there fast ways of estimating the location of the center of a sphere from knowing many points on the sphere? Our convergence rate (coinciding with that of the Random Kaczmarz method) comes from simple averaging, can one do better?
Correlated sexual selection on male genitalia, copulatory performance and nuptial gifts in a bushcricket (Orthoptera: Tettigoniidae) indicated by allometric scaling
Authors: Lehmann Gerlind U C , Kuchenreuther Sina , Lehmann Arne W , Dickhaus Thorsten
Published: March 2021

We adopt an allometric framework of scaling relationships for comparison between mating-related traits in the middle European bushcricket Roeseliana roeselii (Hagenbach, 1822). Eight characters, covering ontogenetic fitness (size traits; fixed at final moult), male condition (mass traits) and mating motivation (reproductive behaviours), were analysed in unrestricted matings and in matings involving genital manipulation. Shortening the male titillators had no effect on mating-related traits in males. However, titillators, known to be under sexual selection, scale hyperallometrically, with larger males possessing proportionally longer titillators, performing more titillator movements and exhibiting a reduced duration of copulation. Scaling was also hyperallometric for spermatophore mass, with larger males being heavier and transferring heavier nuptial gifts. Both titillator length and spermatophore mass might be condition-dependent indicators, because their variances were nearly twice as large those of body size or body mass. Mass traits were also dynamic, increasing by 11% for male body mass and 17% for spermatophore mass between the first and second matings. Sexual selection by female choice seems to favour larger trait size in the bushcricket R. roeselii, acting in concert on titillator length, intensity of titillator movements and spermatophore mass.
Overview of extracellular vesicles in the pathogenesis of preeclampsia
Authors: Wang Zheng , Zhao Gongxiao , Zeng Ming , Feng Weiyi , Liu Jinjun
Published: March 2021

Preeclampsia (PE) is a leading cause of maternal and fetal-neonatal deaths, and its pathogenesis has been linked to the involvement of extracellular vesicles (EVs). EVs are a heterogeneous group of cell-originated membranous vesicles including exosomes, microvesicles, and apoptotic bodies. EVs transport various bioactive cargos such as lipids, proteins, or nucleic acids, and thus mediate cellular communication and contribute to the proper functioning of cells, organs and processes, including normal pregnancy. Numerous studies have reported that EVs are associated with abnormal levels of soluble fms-like tyrosine kinase-1 (sFlt-1), soluble endoglin (sEng), and placental growth factor (PlGF) in PE. EVs isolated from preeclamptic women have been implicated in trophoblast dysfunction and have been reported to activate endothelium, monocytes, and platelets, and to be involved in defective placentation, imbalanced angiogenesis, and intravascular inflammation. When injected into pregnant rodents, these EVs induced hypertension, proteinuria, and adverse fetal outcomes. Deciphering the contribution of EVs to PE will advance our current understanding of this disorder and may lead to more clinical strategies for the management of PE. Of note, the composition of EV cargos may be characteristic of the status and stages of gestation, providing researchers the possibility of one day using EVs as novel, noninvasive, biomarkers for early screening of PE. Herein, we reviewed the latest research into EVs with emphasis on their role in the pathogenesis of PE and their applications as biomarkers in the early screening of this pregnancy-specific disorder.
Diffusion Imaging Reveals Sex Differences in the White Matter Following Sports-Related Concussion
Authors: Wright David K , Symons Georgia F , O’Brien William T , McDonald Stuart J , Zamani Akram , Major Brendan , Chen Zhibin , Costello Daniel , Brady Rhys D , Sun Mujun , Law Meng , O’Brien Terence J , Mychasiuk Richelle , Shultz Sandy R
Published: March 2021

Sports-related concussion (SRC) is a serious health concern. However, the temporal profile of neuropathophysiological changes after SRC and how these relate to biological sex are still poorly understood. This preliminary study investigated whether diffusion-weighted magnetic resonance imaging (dMRI) was sensitive to neuropathophysiological changes following SRC; whether these changes were sex-specific; and whether they persisted beyond the resolution of self-reported symptoms. Recently concussed athletes (n = 14), and age- and education-matched nonconcussed control athletes (n = 16), underwent MRI 24–48-h postinjury and again at 2-week postinjury (i.e., when cleared to return-to-play). Male athletes reported more symptoms and greater symptom severity compared with females. dMRI revealed white matter differences between athletes with SRC and their nonconcussed counterparts at 48-h postinjury. These differences were still present at 2-week postinjury, despite SRC athletes being cleared to return to play and may indicate increased cerebral vulnerability beyond the resolution of subjective symptoms. Furthermore, we identified sex-specific differences, with male SRC athletes having significantly greater white matter disruption compared with female SRC athletes. These results have important implications for the management of concussion, including guiding return-to-play decisions, and further improve our understanding regarding the role of sex in SRC outcomes.
Quantitative Determination of Methohexital in Human Whole Blood by Liquid Chromatography Tandem Mass Spectrometry
Authors: Zhang Yi , Zhang Yunfeng , Zhai Chunfeng
Published: March 2021

A rapid, simple and sensitive liquid chromatography tandem mass spectrometry method for the determination of methohexital in human whole blood was developed and validated. Ethyl acetate/n-hexane (9:1) was used as extraction solvent while aprobarbital was used as internal standard. Methohexital was recovered by liquid–liquid extraction from 100 μL of human whole blood. The mobile phase was water-acetonitrile, and an ACQUITY BEH C18 (2.1 × 100 mm, 1.7 μm) column was adopted. Negative electrospray ionization source and multiply reaction monitoring mode were applied. The transitions of m/z were 261.2/42.2 and 261.2/119.0 for methohexital. The limit of detection was 0.5 ng/mL, which was lower than the previous methods. Wide linear range (2–2,000 ng/mL) with a good correlation coefficient (r > 0.99) was also obtained. The intra- and inter- day precisions represented by relative standard deviation were <11.5%, and the recoveries were >79.67%. This analytical method involved small sample volume and had been proven to be rapid, easy, sensitive and specific. Therefore, it could be used for the clinical analysis of methohexital.
A simple model for the evolution of temperature-dependent sex determination explains the temperature sensitivity of embryonic mortality in imperiled reptiles
Authors: Lawson Lauren , Rollinson Njal
Published: March 2021

A common reptile conservation strategy involves artificial incubation of embryos and release of hatchlings or juveniles into wild populations. Temperature-dependent sex determination (TSD) occurs in most chelonians, permitting conservation managers to bias sex ratios towards females by incubating embryos at high temperatures, ultimately allowing the introduction of more egg-bearing individuals into populations. Here, we revisit classic sex allocation theory and hypothesize that TSD evolved in some reptile groups (specifically, chelonians and crocodilians) because male fitness is more sensitive to condition (general health, vigor) than female fitness. It follows that males benefit more than females from incubation environments that confer high-quality phenotypes, and hence high-condition individuals. We predict that female-producing temperatures, which comprise relatively high incubation temperatures in chelonians and crocodilians, are relatively stressful for embryos and subsequent life stages. We synthesize data from 28 studies to investigate how constant temperature incubation affects embryonic mortality in chelonians with TSD. We find several lines of evidence suggesting that warm, female-producing temperatures are more stressful than cool, male-producing temperatures. Further, we find some evidence that pivotal temperatures (TPiv, the temperature that produces a 1:1 sex ratio) may exhibit a correlated evolution with embryonic thermal tolerance. If patterns of temperature-sensitive embryonic mortality are also indicative of chronic thermal stress that occurs post-hatching, then conservation programs may benefit from incubating eggs close to species-specific TPivs, thus avoiding high-temperature incubation. Indeed, our models predict that, on average, a sex ratio of >75% females can generally be achieved by incubating eggs only 1°C above TPiv. Of equal importance, we provide insight into the enigmatic evolution of TSD in chelonians, by providing support to the hypothesis that TSD evolution is related to the quality of the phenotype conferred by incubation temperature, with males produced in high-quality incubation environments.
Commoners on Crusade: The Creation of Political Space?
Authors: Tyerman C J
Published: March 2021

According to a monastic chronicler from Lower Saxony, in October 1147, at Nicaea in Asia Minor, tensions within the crusade host of Conrad III of Germany threatened to erupt into mutiny. The chronicler pinned the blame on rumours that Conrad proposed bailing out the poverty-stricken and amateurish infantry and despatching them by sea directly to the Holy Land. The putative recipients angrily rejected royal largesse and authority, electing their own leader, a man called Bernard, and condemning Conrad with the words: ‘Since he scorns to have common people (plebem) with him, we refuse to follow him as king’. In this story, the king backed down. Whether or not these events actually happened, the incident conforms to similar descriptions of popular challenges to crusade leadership emerging from almost all the large-scale crusade campaigns to the eastern Mediterranean from the First Crusade onwards. Shared features include collective non-noble identity; organised popular political action; active public dialogue between commanders and their followers; social tensions that expose suspicions of elite self-interest and backsliding; and an outline of a coherent set of commoner ideological principles revolving around a desire to maintain, and occasionally to assert, communal fraternity across social groups in a common cause.
Pump flow setting and assessment of unloading in clinical practice
Authors: Møller Jacob Eifer , Hassager Christian , Bonello Laurent , Delmas Clement , Pappalardo Federico
Published: March 2021

The rationale for mechanical circulatory support (MCS) in cardiogenic shock is to restore cardiac output in selected patients when critically low or in case of refractory cardiac arrest. Furthermore, an MCS device that moves blood from either the left atrium or the left ventricle to the systemic circulation will potentially unload the ventricle. These devices are used alone or in combination with venoarterial extracorporeal membrane oxygenation (VA-ECMO). If a left-sided Impella device is used, it should be run at the highest possible performance level during treatment while avoiding suction events. When combined with VA-ECMO, the Impella device should be run at a lower performance level, ensuring sufficient left ventricular emptying but avoiding suction. Continuous monitoring is pivotal and patients managed outside the catheterization laboratory should be monitored with an arterial line, a central venous catheter, frequent use of pulmonary artery catheters and regular imaging by transthoracic echocardiogram.
Aromatic compound-degrading taxa in an anoxic coal seam microbiome from the Surat Basin, Australia
Authors: C Campbell Bronwyn , Gong Se , Greenfield Paul , J Midgley David , T Paulsen Ian , C George Simon
Published: March 2021

Methane is an important energy resource internationally, and a large proportion of this methane is produced by microbial communities living in coal seams. Despite the value of this resource for human energy security, our understanding of the metabolic roles played by specific taxa during the biodegradation of coal to methane in situ is quite limited. In order to develop a greater understanding of microbial catabolism on coal, a community from a coal seam in the Surat Basin, Australia, was incubated on 10 different aromatic organic compounds: coronene, benzo[a]pyrene, pyrene, phenanthrene, naphthalene, ethylbenzene, phenol, benzoate, vanillate and syringate. Each of these aromatic compounds either occurs in coal or is a possible product of the coal biodegradation process. 16S rRNA sequencing revealed substantial changes to each community in response to each aromatic carbon substrate provided. Abundant taxa from these substrate-specific communities were identified and their probable catabolic roles proposed based on literature searches of related taxa. This study is the first to link specific coal seam taxa to aromatic substrates available in coal seam environments. Two conceptual models of the putative degradation pathways and key taxa responsible are proposed.
Bacteria responsible for antimonite oxidation in antimony-contaminated soil revealed by DNA-SIP coupled to metagenomics
Authors: Zhang Miaomiao , Kolton Max , Li Zhe , Lin Hanzhi , Li Fangbai , Lu Guimei , Gao Pin , Sun Xiaoxu , Xu Rui , Xu Fuqing , Sun Weimin
Published: March 2021

Antimony (Sb), the analog of arsenic (As), is a toxic metalloid that poses risks to the environment and human health. Antimonite (Sb(III)) oxidation can decrease Sb toxicity, which contributes to the bioremediation of Sb contamination. Bacteria can oxidize Sb(III), but the current knowledge regarding Sb(III)-oxidizing bacteria (SbOB) is limited to pure culture studies, thus underestimating the diversity of SbOB. In this study, Sb(III)-oxidizing microcosms were set up using Sb-contaminated rice paddies as inocula. Sb(III) oxidation driven by microorganisms was observed in the microcosms. The increasing copies and transcription of the arsenate-oxidizing gene, aioA, in the microcosms during biotic Sb(III) oxidation indicated that microorganisms mediated Sb(III) oxidation via the aioA genes. Furthermore, a novel combination of DNA-SIP and shotgun metagenomic was applied to identify the SbOB and predict their metabolic potential. Several putative SbOB were identified, including Paracoccus, Rhizobium, Achromobacter and Hydrogenophaga. Furthermore, the metagenomic analysis indicated that all of these putative SbOB contained aioA genes, confirming their roles in Sb(III) oxidation. These results suggested the concept of proof of combining DNA-SIP and shotgun metagenomics directly. In addition, the identification of the novel putative SbOB expands the current knowledge regarding the diversity of SbOB.
Classroom undergraduate research experiences are a “CURE” that increases engagement by students and teachers
Authors: Scott Kathleen M
Published: March 2021

It is widely acknowledged that having experience conducting research is invaluable for undergraduate science students. Most undergraduate research is undertaken by students in a mentor's laboratory, but this limits the number of opportunities for students, as each laboratory can only take on a certain number of undergraduate researchers each semester. Additionally, it is also widely acknowledged that it is difficult for teachers to meet research goals while providing the best possible coursework for undergraduate students. Both of these bottlenecks can be circumvented via Classroom Undergraduate Research Experiences (CUREs), which integrate research into the curricula of structured undergraduate classes. Students enrolled in classes that include CUREs conduct research to address open-ended questions as part of their coursework. In this commentary, I describe the many ways in which CUREs are helpful for students and teachers, as well as considerations for designing successful CUREs. I provide several examples of CUREs from Microbial Physiology laboratory classes and Genomics classes that I have taught. Results from these CUREs have been successfully integrated into many peer-reviewed publications in which the students are co-authors, which has been a boon both to students’ post-baccalaureate opportunities, as well as my research agenda.
High-resolution genetic dissection of the major QTL for tipburn resistance in lettuce,Lactuca sativa
Authors: Macias-González Miguel , Truco Maria Jose , Han Rongkui , Jenni Sylvie , Michelmore Richard W
Published: March 2021

Tipburn is an important physiological disorder of lettuce, Lactuca sativa L., related to calcium deficiency that can result in leaf necrosis and unmarketable crops. The major quantitative trait locus (QTL), qTPB5.2, can account for up to 70% of the phenotypic variance for tipburn incidence in the field. This QTL was genetically dissected to identify candidate genes for tipburn by creating lines with recombination events within the QTL and assessing their resistance to tipburn. By comparing lines with contrasting haplotypes, the genetic region was narrowed down to ∼877 Kb that was associated with a reduction of tipburn by ∼60%. Analysis of the lettuce reference genome sequence revealed 12 genes in this region, one of which is a calcium transporter with a single nucleotide polymorphism in an exon between haplotypes with contrasting phenotypes. RNA-seq analysis of recombinants revealed two genes that were differentially expressed between contrasting haplotypes consistent with the tipburn phenotype. One encodes a Teosinte branched1/Cycloidea/Proliferating Cell factor transcription factor; however, differential expression of the calcium transporter was detected. The phenotypic data indicated that there is a second region outside of the ∼877 Kb region but within the QTL, at which a haplotype from the susceptible parent decreased tipburn by 10–20%. A recombinant line was identified with beneficial haplotypes in each region from both parents that showed greater tipburn resistance than the resistant parent; this line could be used as the foundation for breeding cultivars with more resistance than is currently available.
Municipal health promotion programs: is childhood obesity a concern at local level in Portugal?
Authors: Pereira Margarida , Padez Cristina , Nogueira Helena
Published: March 2021

Health promotion programs, targeted at distinct health outcomes such as childhood obesity, at local level are increasingly used worldwide. Therefore, there is a need to better understand the role of local governments (municipalities) as key public health promoters namely in the prevention of obesity in children. We aimed to provide some input regarding this issue in Portugal. First, we identified health-enhancing programs promoted by Portuguese municipalities in which children could participate. Then, we conducted a document analysis to provide clues about how municipalities conceptualized child health by retrieving information on which topics the programs were focused in, or acted upon, and identifying which socio-ecological model levels were addressed (or not) by each program. The 77 identified programs were promoted by 30 of the 308 Portuguese municipalities and only 11 programs addressed childhood obesity. Most programs focused in the individual health determinants and provided limited information which disabled its deeper analysis. Portuguese municipalities seem to disregard their potential as public health promoters. Childhood obesity is a major public health concern at national (and global) level but the same does not emerge locally. Municipalities are the closest government entities to the population, and it is their responsibility to ensure the population’s quality of life, by addressing the social determinants and the physical environments. Therefore, municipalities should acknowledge health in their actions and delineate health improvement programs considering current evidence, specifically in the case of childhood obesity prevention that besides being a health problem in itself, is a risk factor for non-communicable diseases.