bluuebunny/crossref_metadata_2025_split huggingface dataset:
Shrub‐encroached grassland as an alternative stable state in semiarid steppe regions: Evidence from community stability and assembly
Authors: Hao Guang , Yang Nan , Dong Ke , Xu Yujuan , Ding Xinfeng , Shi Xinjian , Chen Lei , Wang Jinlong , Zhao Nianxi , Gao Yubao 
Published: April 2021

AbstractUnderstanding community restoration state and assembly mechanisms is helpful to assess restoration measures and predict community dynamics. In order to explore the effects of fencing duration and shrub cover on community stability and assembly, we investigated the community information and assessed the assembly mechanisms in plots using shrub cover of Caragana microphylla within each of the three sites fenced since 1979, 1983, and 2003 in a semiarid steppe region of China. Community composition was different among various fencing duration or shrub cover treatments. Shrub cover had a positive effect, and fencing duration had a negative effect on community stability, and both had indirect effects via regulating vegetation cover. Both shrub cover and fencing duration influenced phylogenetic structure directly and negatively, and indirectly via regulating Simpson's diversity and vegetation cover. Considering that the functional traits were phylogenetically convergent, community assembly mechanisms assessed by the values of phylogenetic structure shifted from stochasticity to competitive exclusion with the increase of shrub cover and fencing duration, and competitive exclusion dominated community assembly in the plots of low or high shrub cover in the site of fencing since 1979. The responses of community stability and community assembly to the changes of shrub cover and fencing duration suggest that the shrub‐encroached grassland is an alternative stable community state in semiarid steppe regions. Therefore, it is essential to distinguish shrub‐encroached grasslands from non‐encroached degraded grasslands when formulating relevant conservation and management measures in similar regions.
Triglyceride/High‐Density Lipoprotein Cholesterol Ratio: A Clue to Metabolic Syndrome, Insulin Resistance, and Severe Atherosclerosis
Authors: Azarpazhooh M. Reza , Najafi Farid , Darbandi Mitra , Kiarasi Soushyant , Oduyemi Temilola , Spence J. David 
Published: April 2021

AbstractHigh serum levels of triglycerides (Tg) and low levels of high‐density lipoprotein cholesterol (HDL‐C) are characteristic of the Metabolic Syndrome (MetS). We assessed the ratio of Tg to HDL‐C as a way to identify MetS and insulin resistance. We also evaluated its association with severity of carotid atherosclerosis. Data were analyzed from three cohorts totaling 13,908 participants. MetS was defined according to the International Diabetes Federation criteria. Optimal cut‐off for Tg/HDL‐C ratio was obtained using Youden's index in receiver‐operating characteristic (ROC) curve analyses. The risk of MetS and IR in those with a Tg/HDL‐C ratio above the optimum cutoff was evaluated by logistic regression analysis. A Tg/HDL‐C ratio above the optimal cutoff level significantly increased the odds ratio for MetS in the three cohorts (OR 6.00, 4.04, and 3.50, least in the healthy population), identified insulin resistance defined by the homeostatic model of insulin resistance (HOMA‐IR) (p < 0.0001), and was strongly associated with atherosclerosis severity (p = 0.0001). Tg/HDL‐C ratio identifies persons with MetS, insulin resistance, and severe atherosclerosis. It should be used more widely to identify patients at high risk. This is clinically important because insulin resistance is treatable.
SBS Thermoplastic Elastomer Based on Dynamic Metal‐Ligand Bond: Structure, Mechanical Properties, and Shape Memory Behavior
Authors: Wang Qiang , He Yu , Li Qiuying , Wu Chifei 
Published: April 2021

AbstractA Cooper(II) (Cu2+)‐nitrogen coordination‐crosslinked network is designed in poly(styrene‐co‐butadiene‐co‐styrene) (SBS) to change commercial elastomers into advanced soft materials. Herein, ligand groups into SBS molecular chains by the 3,6‐di(2‐pyridyl)‐1,2,4,5‐tetrazine (DPT) click reaction are first introduced. The results from fourier transform infrared (FT‐IR), 1H‐nuclear magnetic resonance, and X‐ray photoelectron spectroscopy (XPS) are verified the successful modification of SBS. The DPT‐grafted SBS could then coordinate with copper sulfate (CuSO4) to form a Cu2+‐nitrogen bond, which is further characterized using FT‐IR, XPS, atomic force microscope, scanning electron microscope, and geometric structure calculations. After modifying SBS to form an SBS‐DPT/CuSO4 composite (SBS‐DPT2‐Cu10), the tensile stress is improved from 11.43 to 23.25 MPa, while the elongation at break is remained almost unchanged, and the corresponding toughness is increased from 33.21 to 63.26 MJ m–3. Moreover, the dynamic nature of the Cu2+‐nitrogen coordination bonds enables the SBS‐DPT/CuSO4 composite to exhibit sustained thermoplastic performance and excellent shape memory behavior under an external thermal stimulus.
Impact of capacity on the supplier's distribution channel selection in facing a retail platform
Authors: Xie Xia , Hu Peng , Yu Jing , Dai Bin 
Published: April 2021

AbstractIn the presence of agency selling in emerging retail platforms, suppliers are motivated to select purely traditional reselling, agency selling or a hybrid distribution channel strategy. In this paper, considering a capacity‐constrained supplier facing a retail platform, we examine the equilibrium pricing and ordering decisions in the hybrid channel, and further analyze the impact of limited capacity on the supplier's distribution channel selection as well as equilibrium outcomes. Results show that the hybrid channel always dominates pure agency selling. In comparison to the unlimited capacity setting, we find that limited capacity motivates the supplier to select pure reselling under a low commission rate. However, under a moderate commission rate, moderate capacity motivates the supplier to select the hybrid channel. We also show that, under moderate capacity in the hybrid channel, the retail platform may order all the supplier's capacity and strategically withhold some to avoid downstream competition, and that the impact of commission rate on the capacity thresholds of withholding behavior may be nonmonotonic. Interestingly, we find that moderate capacity may benefit the supplier, the retail platform, and consumers at the same time, creating a win–win–win outcome.
An efficient algorithm for solving the nonnegative tensor least squares problem
Authors: Duan Xue‐Feng , Duan Shan‐Qi , Li Juan , Li Jiao‐fen , Wang Qing‐Wen 
Published: April 2021

AbstractIn this paper, we consider the nonnegative tensor least squares problem, which arises in the color image restoration. Based on the BB stepsize technique, we design a nonmonotonic descent stepsize and then derive a new gradient projection algorithm to solve this problem. The convergence analysis of the new gradient projected algorithm is given. Some numerical examples show that the new method is feasible and effective. Especially, some simulation experiments in the color image restoration problems illustrate that our algorithm is more effective than the existed algorithms.
A subspace iteration eigensolver based on Cauchy integrals for vibroacoustic problems in unbounded domains
Authors: Baydoun Suhaib Koji , Voigt Matthias , Goderbauer Benedikt , Jelich Christopher , Marburg Steffen 
Published: April 2021

AbstractDespite the potential and the increasing popularity of the boundary element method (BEM), modal analyses based on BEM are not yet put into engineering practice, mainly due to the lack of efficient solvers for the underlying nonlinear eigenvalue problem (EVP). In this article, we review a subspace iteration method based on FEAST for the solution of vibroacoustic EVPs involving the finite element method (FEM) and BEM. The subspace is obtained by applying a spectral projector and is computed by contour integration, whereas the contour is also used to subsequently solve the projected EVP by rational approximation. The computation of the projection matrices is addressed by two approaches. In the case of heavy fluid loading, we solve the underlying coupled linear systems by an iterative block Krylov method. In the case of light fluid loading, we exploit the fact that the coupled system admits accurate model order reduction solely based on the structural subsystem. Applications to a spherical shell and to a musical bell indicate that only a few contour points are required for an accurate solution without inducing spurious eigenvalues. The results are compared with those of a contour integral method and illustrate the efficiency of the proposed eigensolver.
The role of knowledge sharing in volunteer learning and development
Authors: Fullwood Roger , Rowley Jennifer 
Published: April 2021

AbstractDespite the growing importance of volunteers to many organizations, there has been little research into how they share their knowledge and develop the skills they need. Moreover, the focus of existing research has been on short‐term episodic volunteering. This article addresses these deficits by examining the significance of knowledge sharing to volunteer development and also the relative importance of individual processes. A case study approach is adopted, which focuses on a major heritage site that is heavily reliant on a volunteer workforce. Development of volunteers is particularly relevant to the heritage sector where organizations need a sizeable, stable, and well‐trained volunteer workforce. We performed semi‐structured interviews with six managers as well as conducting five focus groups with volunteers from diverse work areas in the National Trust. The Volunteer Development through Knowledge Sharing Model is proposed. This is the first conceptual model to summarize the processes in volunteer development. Processes are clustered as follows: informal learning, formal training, learning resources, and research by volunteers. Informal learning through tacit knowledge sharing is pre‐eminent and knowledge created by volunteer research was highly significant for educating visitors. The characteristics of the volunteer workforce were found to affect all these processes. Implications for practitioners are also discussed.
Macroion molecule properties from slender body hydrodynamics
Authors: Adamczyk Zbigniew , Batys Piotr , Płaziński Wojciech , Morga Maria , Lupa Dawid , Michna Aneta 
Published: April 2021

AbstractThe all‐atom molecular dynamics simulations were applied to determine physicochemical parameters for poly‐l‐lysine (a cationic macroion) and λ‐carrageenan (an anionic polysaccharide macroion) comprising the monomer length and the density. The molecule chain diameter for an equivalent cylinder was also calculated. These results were used for the interpretation of experimental data derived from dynamic viscosity measurements of macroion solutions enabling the intrinsic viscosity to be determined. It was confirmed that the molecules assume extended rod‐like conformations in dilute NaCl solutions. Considering the slender body hydrodynamics, the length to diameter parameter (aspect ratio) of the molecules was calculated as a function of their intrinsic viscosity. Using this parameter, the molar mass of macroions can be precisely calculated from a linear dependence derived in this work. The proportionality constant can be ab initio calculated using molecular dynamics modeling. It is confirmed that the formula yields reliable results for both anionic and cationic macroions. Except for the molar mass, the method can be used to predict the diffusion coefficient, the hydrodynamic diameter, the radius of gyration, and the sedimentation coefficients of macroion molecules in dilute electrolytes.
Manufacturing and characterization of novel silicone/natural fabric/graphene‐based functional composites for human body motion sensing
Authors: Mohan Velram Balaji , Santhana Krishnan Sushmitha , Bhattacharyya Debes 
Published: April 2021

AbstractThis study focuses on the development of strain‐sensors utilizing biodegradable natural fabrics (cotton, flax, and wool) and graphene nanoplatelets (GN) through novel coating techniques. A systematic study on improving the electrical conductivity of natural fiber fabrics to be used as effecting sensing stimuli was conducted by varying the proportions of graphene. To further enhance the conductivity, GN was hybridized with conducting polymers, such as polypyrrole (PPy), polyaniline (PANI), and with carbon black (CB). The electrical conductivity, morphological, and mechanical characterizations were carried composites for detailed comparative analysis. The conductive composites were incorporated into flexible and stretchable silicone elastomer (Ecoflex) to be used as strain sensors. Electromechanical characterizations were carried out on the composite sensors and their performance on different human body motions, including finger, wrist, elbow, and knee movements were assessed. The results showed that the addition of hybrids, such as PPy increased the electrical conductivity in fabrics (for instance, cotton with a conductivity of 1.7 S.cm−1). However, the addition of PANI tends to have a negative effect on the conductivity due to poor ability to deposit on the fiber surface. It was observed that the thermal stability was improved with the addition of conductive particles which gives rise to excellent sensitivity and durability of the composite sensors.
Quantification of crocin, picrocrocin and safranal in saffron stigmas obtained from sounded corms with acoustic waves
Authors: Razavizadeh Bibi Marzieh , Arabshahi Delooei Noora 
Published: April 2021

AbstractIntroductionPlant acoustic frequency technology (PAFT) is the effect or treatment of a plant with a specific frequency sound wave.ObjectiveThe sound waves with different frequencies and a sound pressure level 77 dB were emitted on the saffron corms in a controlled environment using aeroponic cultivation and the contents of crocin, picrocrocin and safranal in their produced stigmas were analysed by high‐performance liquid chromatography. For this purpose, the corms were divided into two groups. In group 1, sound waves with the frequencies of 0.5, 1 and 2 kHz were emitted on saffron corms in different stages of sprouting, flowering and the whole stage of sprouting and flowering. In group 2, sonication was performed on the corms during the flowering stage at 4, 8, 12 and 16 kHz frequencies.ResultsThe changes in the contents of crocin, picrocrocin and safranal were not significantly compared to the control at 0.5, 1 and 2 kHz frequencies in the stages of sprouting and flowering of corms. While the higher frequencies (4, 8, 12 and 16 kHz) in flowering stage were affected significantly, the crocin and picrocrocin content increased 8.5% and 30%, applying the frequency of 12 and 8 kHz, respectively. Also, the effect of sound exposure time per day with the frequency of 16 kHz at 15, 30 and 60 min were investigated.ConclusionThe findings showed that the corms could be affected by sounding in the different stages of growth of the corm and also in the content of secondary metabolites.
Stand up to action: The postural effect of moral dilemma decision‐making and the moderating role of dual processes
Authors: Liu Chuanjun , Liao Jiangqun 
Published: April 2021

AbstractPrevious studies have demonstrated the possibility that when people are in standing rather than sitting postures, they have a stronger cognitive control propensity, making them inclined to agree more to sacrificing one innocent person and saving more people. Furthermore, this postural effect can be moderated by dual processes. In three studies, participants read dilemma scenarios followed by a proposed behavior to sacrifice one innocent person and save five or more people. The participants in sitting or standing postures were asked whether the described action was morally acceptable (moral judgment) and whether they would perform the described action (moral action). The results demonstrated that participants were more approving of the behavioral proposal in the moral action perspective than in the moral judgment perspective across the three studies. The hypothesized postural effect was found in a field study (Study 1) and replicated in a preregistered replication study (Study 2), and was further supported in an experimental study (Study 3). Compared with those in sitting postures, participants in standing postures expressed higher approval of the behavioral proposal compared to their sitting counterparts. Furthermore, the postural effect was dismissed when participants made moral decisions with a dual task to increase cognitive load, and it was reversed when they made moral decisions after deliberate consideration of the behavioral proposal (Study 3). The present research supports and extends the dual‐process morality theory by demonstrating that body posture can affect moral decision‐making; it also offers novel evidence revealing the moderating role of dual process on embodiment effects. It enriches our knowledge that morality is evolutionarily embodied in postures and that the dual process can moderate embodiment effects.
Practice patterns of prenatal and perinatal testing in Canadian cytogenetics laboratories
Authors: Ashfield Tamara , McCready Elizabeth , Shago Mary , Wang Hong , Sinclair‐Bourque Elizabeth , Cappa Eva , Piche Marolt Amanda , Chun Kathy 
Published: April 2021

AbstractObjectiveTo survey patterns of practice in Canadian cytogenetics laboratories and evaluate whether newer technologies have influenced testing algorithms for the detection of common aneuploidies and other genomic imbalances in the prenatal and perinatal settings.MethodsCytogenetics laboratories across Canada were invited to participate in two patterns‐of‐practice surveys: one in 2016 and one in 2019. They were asked to identify the prenatal and perinatal specimen types tested at their facility and which testing methods were used for initial testing and for follow‐up.ResultsAll clinical laboratories performing prenatal testing offer rapid aneuploidy detection (RAD). Most laboratories also offer microarray analysis. A positive result is either followed up by karyotyping or no further testing is performed. For prenatal samples, a negative result may be followed up by microarray or karyotyping and is dependent on the reason for referral. For perinatal samples, availability of microarray to follow up a negative result is increasing.ConclusionsSince 2016, the availability of RAD as a first‐line test in Canadian cytogenetics laboratories remains consistent, while microarray has become the preferred follow‐up testing method over traditional karyotyping following a normal RAD result. Despite a universal healthcare system, disparities in prenatal and perinatal cytogenetic testing algorithms are apparent.
Highly efficient nitrogen fixation enabled by an atmospheric pressure rotating gliding arc
Authors: Chen Hang , Wu Angjian , Mathieu Stéphanie , Gao Peihan , Li Xiaodong , Xu Bo Z. , Yan Jianhua , Tu Xin 
Published: April 2021

AbstractA rotating gliding arc is proposed as a promising alternative to enable direct nitrogen fixation from ubiquitous air under mild conditions. The effect of different process parameters on NO
x
generation and energy consumption has been investigated through a combination of experiments and artificial neural network (ANN) modeling. The optical emission spectroscopic diagnostics together with electrical diagnostics and high‐speed photography has been used to understand the variation of the discharge characteristics. The lowest energy consumption of NO
x
production (4.2 MJ/mol) is achieved at a gas flow rate of 12 L/min and an O2 concentration of 20 vol%. The simulation results from the ANN model show a good agreement with the experimental data and the model enables us to evaluate the relative importance of the process parameters to the reaction performance.
Sarsasapogenin ameliorates diabetes‐associated memory impairment and neuroinflammation through down‐regulation of PAR‐1 receptor
Authors: Kong Li , Liu Yue , Zhang Yu‐Meng , Li Yu , Gou Ling‐Shan , Ma Teng‐Fei , Liu Yao‐Wu 
Published: April 2021

Sarsasapogenin (Sar), a natural steroidal compound, shows neuroprotection, cognition‐enhancement, antiinflammation, antithrombosis effects, and so on. However, whether Sar has ameliorative effects on diabetes‐associated cognitive impairment remains unknown. In this study, we found that Sar ameliorated diabetes‐associated memory impairment in streptozotocin‐induced diabetic rats, evidenced by increased numbers of crossing platform and percentage of time spent in the target quadrant in Morris water maze tests, and suppressed the nucleotide‐binding domain and leucine‐rich repeat containing protein 1 (NLRP1) inflammasome in hippocampus and cerebral cortex. Furthermore, Sar inhibited advanced glycation end‐products and its receptor (AGEs/RAGE) axis and suppressed up‐regulation of thrombin receptor protease‐activated receptor 1 (PAR‐1) in cerebral cortex. On the other hand, Sar mitigated high glucose‐induced neuronal damages, NLRP1 inflammasome activation, and PAR‐1 up‐regulation in high glucose‐cultured SH‐SY5Y cells, but did not affect thrombin activity. Moreover, the effects of Sar were similar to those of a selective PAR‐1 antagonist vorapaxar. Further studies indicated that activation of the NLRP1 inflammasome and NF‐κB mediated the effect of PAR‐1 up‐regulation in high glucose condition by using PAR‐1 knockdown assay. In summary, this study demonstrated that Sar prevented memory impairment caused by diabetes, which was achieved through suppressing neuroinflammation from activated NLRP1 inflammasome and NF‐κB regulated by cerebral PAR‐1.Highlights
Sarsasapogenin ameliorated memory impairment caused by diabetes in rats.
Sarsasapogenin mitigated neuronal damages and neuroinflammation by down‐regulating cerebral PAR‐1.
The NLRP1 inflammasome and NF‐κB signaling mediated the pro‐inflammatory effects of PAR‐1.
Sarsasapogenin was a pleiotropic neuroprotective agent and memory enhancer in diabetic rodents.
Spatial and temporal trends of Minnesota River phytoplankton and zooplankton
Authors: Sindt Anthony R. , Wolf Michael C. 
Published: April 2021

AbstractPlankton communities have important roles in aquatic ecosystems, but studies of plankton in lotic systems are infrequent. We collected over 100 water, phytoplankton, and zooplankton samples during 2016–2018 to explore spatiotemporal trends in Minnesota River plankton communities and evaluate relationships with physico‐chemical factors. Phytoplankton and zooplankton community structure exhibited temporal patterns but only the zooplankton community differed spatially. Cyanobacteria (M ± SE; 11.27 ± 1.43 mm3/L) and diatoms (8.12 ± 1.08 mm3/L) dominated phytoplankton biovolume with seasonal peaks in Cyanobacteria occurring during July–September and peaks in diatoms occurring during May, August, and September. All phytoplankton taxa except Cryptophyta exhibited a negative relationship with relative discharge. Crustacean zooplankton biomass was greatest at two upstream sites (146.7 ± 32.6 μg/L) where cladocerans and copepods were likely exported from upstream of dams where water residence time is greater. Within the lower free‐flowing reach rotifers dominated the zooplankton community (207.9 ± 40.9 individuals/L and 6.5 ± 1.0 μg/L). Thus, spatial differences in zooplankton community structure were primarily attributed to the influence of dams. Seasonal patterns in zooplankton community structure included peaks in Chydoridae, cyclopoid, immature copepod, and rotifer biomass during May and Bosminidae biomass during October. Excluding the influence of dams on zooplankton, the cumulative effects of month and relative discharge were the most important for explaining variability in plankton community structure. Baseline understanding of plankton community dynamics provides the ability to quantify responses to future perturbations such as climate change and establishment of invasive planktivores.