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Unveiling a new regulator: Vacuolar V-ATPase mediates brassinosteroid signaling in Arabidopsis

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Molecular Plant 2024年第2期17卷 227-229页

作者： Shikha Malik Justin W.Walley Department of Plant Pathology Entomologyand Microbiologylowa State UniversityAmesIA 50011USA

Plant growth and development are intricately regulated by hormones such as auxins,gibberellins,jamonates,cytokinins,and brassinosteroids(BRs).BRs are a group of plant steroid hormones that play a vital role in plant growth and response to the environment.BRs regulate many biological processes including cell elongation,cell division,and male fertility,as well as abiotic and biotic stress responses.

关键词： media fertility brassinosteroid

Abomasal infusion of branched-chain amino acids or branched-chain keto-acids alter lactation performance and liver triglycerides in fresh cows

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Journal of Animal Science and Biotechnology 2024年第3期15卷 1145-1157页

作者： Kristen Gallagher Isabelle Bernstein Cynthia Collings David Main Ghayyoor Ahmad Sarah Naughton Jayasimha Daddam Vengai Mavangira Mike Vandehaar Zheng Zhou Department of Animal Science Michigan State UniversityEast Lansing 48824USA Department of Veterinary Diagnostic and Production Animal Medicine Ames 50011USA

Background Dairy cows are at high risk of fatty liver disease in early lactation,but current preventative measures are not always effective.Cows with fatty liver have lower circulating branched-chain amino acid(BCAA)concentra-tions whereas cows with high circulating BCAA levels have low liver triglyceride(TG).Our objective was to determine the impact of BCAA and their corresponding ketoacids(branched-chain ketoacids,BCKA)on production performance and liver TG accumulation in Holstein cows in the first 3 weeks postpartum.Methods Thirty-six multiparous Holstein cows were used in a randomized block design experiment.Cows were abomasally infused for the first 21 d postpartum with solutions of 1)saline(CON,n=12);2)BCA(67 g valine,50 g leu-cine,and 34 g isoleucine,n=12);and 3)BCK(77 g 2-ketovaline calcium salt,57 g 2-ketoleucine calcium salt,and 39 g 2-ketoisoleucine calcium salt,n=12).All cows received the same diet.Treatment effects were determined using PROC GLIMMIX in SAS.Results No differences were detected for body weight,body condition score,or dry matter intake averaged over the first 21 d postpartum.Cows receiving BCK had significantly lower liver TG concentrations compared to CON(6.60%vs.4.77%,standard error of the mean(SEM)0.49)during the first 3 weeks of lactation.Infusion of BCA increased milk yield(39.5 vs.35.3 kg/d,SEM 1.8),milk fat yield(2.10 vs.1.69 kg/d,SEM 0.08),and lactose yield(2.11 vs.1.67 kg/d,SEM 0.07)compared with CON.Compared to CON,cows receiving BCA had lower plasma glucose(55.0 vs.59.2 mg/dL,SEM 0.86)but higherβ-hydroxybutyrate(9.17 vs.6.00 mg/dL,SEM 0.80).Conclusions Overall,BCAA supplementation in this study improved milk production,whereas BCKA supplementa-tion reduced TG accumulation in the liver of fresh cows.

关键词： Branched-chain amino acids Branched-chain ketoacids Fatty liver Fresh cow

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Substitution of Pb with (Li_(1/2)Bi_(1/2)) in PbZrO_(3)-based antiferroelectric ceramics

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Journal of Advanced Dielectrics 2024年第1期14卷 74-81页

作者： Binzhi Liu Anand P.S.Gaur Jun Cui Xiaoli Tan Department of Materials Science and Engineering Iowa State University AmesIA 50011USA

PbZrO_(3)-based antiferroelectric(AFE)ceramics are promising dielectrics for high-energy-density capacitors due to their reversible phase transitions during charge-discharge cycles.In this work,a new composition series,[Pb_(0.93-x)La_(0.02)(Li_(1/2)Bi_(1/2))_(x)Sr_(0.04)][Zr_(0.57)Sn_(0.34)Ti_(0.09)]O_(3),with Li^(+)and Bi^(3+)substitution of Pb^(2+)at x=0,0.04,0.08,0.12,0.16 is investigated for the microstructure evolution,ferroelectric(FE)and dielectric properties.It is found that Li^(+) and Bi^(3+) substitution can significantly reduce the sintering temperature and simultaneously enhance the dielectric breakdown strength.An ultrahigh energy efficiency(94.0%)and a large energy density(3.22 J/cm^(3))are achieved in the composition of x=0.12 with a low sintering temperature(1075℃).

关键词： PbZrO_(3)-based antiferroelectrics LiþBi substitution energy storage energy efficiency

Evaluation of the Impact of Driver Behavior on Back of Queues Events in Work Zones Using the SHRP2 Naturalistic Driving Study Data

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Journal of Transportation Technologies 2024年第2期14卷 179-194页

作者： Shauna Hallmark Guillermo Basulto-Elias Nicole Oneyear Omar Smadi Institute for Transportation 2711 S. Loop Drive Suite 4700 Ames Iowa Iowa Division Federal Highway Administration Ames Iowa

The SHRP2 Naturalistic Driving Study was used to evaluate the impact of various work zone and driver characteristics on back of queue safety critical events (crash, near-crash, or conflicts) The model included 43 SCE and 209 “normal” events which were used as controls. The traces included representing 209 unique drivers. A Mixed-Effects Logistic Regression model was developed with probability of a SCE as the response variable and driver and work zone characteristics as predictor variables. The final model indicated glances over 1 second away from the driving task and following closely increased risk of an SCE by 3.8 times and 2.9 times, respectively. Average speed was negatively correlated to crash risk. This is counterintuitive since in most cases, it is expected that higher speeds are related to back of queue crashes. However, most queues form under congested conditions. As a result, vehicles encountering a back of queue would be more likely to be traveling at lower speeds.

关键词： Safety Critical Events Speed Following Closely Glance Behavior

Superconvergence of Direct Discontinuous Galerkin Methods:Eigen-structure Analysis Based on Fourier Approach

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Communications on Applied Mathematics and Computation 2024年第1期6卷 257-278页

作者： Xuechun Liu Haijin Wang Jue Yan Xinghui Zhong School of Mathematical Sciences Zhejiang UniversityHangzhou310027ZhejiangChina School of Science Nanjing University of Posts and TelecommunicationsNanjing210023JiangsuChina Department of Mathematics Iowa State UniversityAmes50011IAUSA

This paper investigates superconvergence properties of the direct discontinuous Galerkin(DDG)method with interface corrections and the symmetric DDG method for diffusion equations.We apply the Fourier analysis technique to symbolically compute eigenvalues and eigenvectors of the amplification matrices for both DDG methods with different coefficient settings in the numerical fluxes.Based on the eigen-structure analysis,we carry out error estimates of the DDG solutions,which can be decomposed into three parts:(i)dissipation errors of the physically relevant eigenvalue,which grow linearly with the time and are of order 2k for P^(k)(k=2,3)approximations;(ii)projection error from a special projection of the exact solution,which is decreasing over the time and is related to the eigenvector corresponding to the physically relevant eigenvalue;(iii)dissipative errors of non-physically relevant eigenvalues,which decay exponentially with respect to the spatial mesh sizeΔx.We observe that the errors are sensitive to the choice of the numerical flux coefficient for even degree P^(2)approximations,but are not for odd degree P^(3)approximations.Numerical experiments are provided to verify the theoretical results.

关键词： Direct discontinuous Galerkin(DDG)method with interface correction Symmetric DDG method Superconvergence Fourier analysis Eigen-structure

Population genomic analysis reveals key genetic variations and the driving force for embryonic callus induction capability in maize

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Journal of Integrative Agriculture 2024年第7期23卷 2178-2195页

作者： Peng Liu Langlang Ma Siyi Jian Yao He Guangsheng Yuan Fei Ge Zhong Chen Chaoying Zou Guangtang Pan Thomas Lübberstedt Yaou Shen State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China/Maize Research Institute Sichuan Agricultural UniversityChengdu 611130China Department of Agronomy Iowa State UniversityAmesIA 50011USA

Genetic transformation has been an effective technology for improving the agronomic traits of maize.However,it is highly reliant on the use of embryonic callus(EC)and shows a serious genotype dependence.In this study,we performed genomic sequencing for 80 core maize germplasms and constructed a high-density genomic variation map using our newly developed pipeline(MQ2Gpipe).Based on the induction rate of EC(REC),these inbred lines were categorized into three subpopulations.The low-REC germplasms displayed more abundant genetic diversity than the high-REC germplasms.By integrating a genome-wide selective signature screen and region-based association analysis,we revealed 95.23 Mb of selective regions and 43 REC-associated variants.These variants had phenotypic variance explained values ranging between 21.46 and 49.46%.In total,103 candidate genes were identified within the linkage disequilibrium regions of these REC-associated loci.These genes mainly participate in regulation of the cell cycle,regulation of cytokinesis,and other functions,among which MYB15 and EMB2745 were located within the previously reported QTL for EC induction.Numerous leaf area-associated variants with large effects were closely linked to several REC-related loci,implying a potential synergistic selection of REC and leaf size during modern maize breeding.

关键词： maize genetic transformation embryonic callus selective signal association analysis

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Efficiency of Botanical and Chemical Pesticides on the Control of Field Insect Pests under Cowpea Production

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American Journal of Plant Sciences 2024年第3期15卷 203-221页

作者： John Ssengo Brian Zebosi Jeninah Karungi Department of Plant Pathology Entomology and Microbiology Iowa State University Ames IA USA Department of Agricultural Production Makerere University Kampala Uganda Department of Genetics Development and Cell Biology Iowa State University Ames IA USA

The pulse cowpea [Vigna unguiculata (L.) Walp] holds a significant agricultural position in Uganda, ranking fourth among legume crops, following common beans, groundnuts, and soybeans. Known for its versatility, cowpeas are consumable at various developmental stages, from early seedling to maturity. However, the crop faces persistent pest challenges at each stage, leading to substantial yield losses. In Uganda, chemical insecticides are the primary pest control means, but their increased and excessive use raises environmental, health, and economic concerns. This has prompted a quest for alternative and sustainable solutions, prompting an exploration of botanical insecticides. This study, conducted at Makerere University Agricultural Research Institute (MUARIK), aimed to evaluate the effectiveness of three selected botanical insecticides versus four established chemical insecticides for managing cowpea insect pests under field conditions. The treatments included: Carbofuran, Cypermethrin 10% EC, Dimethoate, Pestwin, Pyrethrum ewc , Pyrethrum 5ew, Profenofos 40% Cypermethrin 4% EC mix, and Untreated, arranged in a randomized complete block design with three replications. The significant pests studied were aphids, thrips, pod-sucking bugs, and legume pod borer. Results indicated substantial impacts of the treatments on pest infestation, with Profenofos 40% Cypermethrin 4% EC being the most effective against most pests. The plant parameter, plant height, was significantly affected by treatments in 2016B, while the number of pods was impacted in 2017A. Pestwin, a botanical insecticide blend (containing Azadirachtin indica, Pongamia pinnata, and Ricinus communis extracts) demonstrated superior efficacy against cowpea aphids. Moreover, it positively influenced plant height, number of pods, and pod biomass, surpassing many chemical insecticides. Pestwin’s environmental friendliness positions it as a potential contributor to reducing environmental pollution, making it a promising candidate for inclusion in IPM programs. O

关键词： Cowpea Pest Management Botanical Solutions Profenofos Sustainability

Speed and surface steepness affect internal tibial loading during running

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Journal of Sport and Health Science 2024年第1期13卷 118-124页

作者： Hannah Rice Markus Kurz Patrick Mai Leon Robertz Kevin Bill Timothy R.Derrick Steffen Willwacher Department of Physical Performance Norwegian School of Sport SciencesOslo 0806Norway Sports Tech Research Centre Mid Sweden UniversityÖstersund SE-83125Sweden Department of Mechanical and Process Engineering Offenburg University of Applied SciencesOffenburg 77652Germany Institute of Biomechanics and Orthopaedics German Sport University CologneCologne 50933Germany Department of Kinesiology Iowa State UniversityAmesIA 50011USA

Background:Internal tibial loading is influenced by modifiable factors with implications for the risk of stress injury.Runners encounter varied surface steepness(gradients)when running outdoors and may adapt their speed according to the gradient.This study aimed to quantify tibial bending moments and stress at the anterior and posterior peripheries when running at different speeds on surfaces of different gradients.Methods:Twenty recreational runners ran on a treadmill at 3 different speeds(2.5 m/s,3.0 m/s,and 3.5 m/s)and gradients(level:0%;uphill:+5%,+10%,and+15%;downhill:-5%,-10%,and-15%).Force and marker data were collected synchronously throughout.Bending moments were estimated at the distal third centroid of the tibia about the medial-lateral axis by ensuring static equilibrium at each 1%of stance.Stress was derived from bending moments at the anterior and posterior peripheries by modeling the tibia as a hollow ellipse.Two-way repeated-measures analysis of variance were conducted using both functional and discrete statistical analyses.Results:There were significant main effects for running speed and gradient on peak bending moments and peak anterior and posterior stress.Higher running speeds resulted in greater tibial loading.Running uphill at+10%and+15%resulted in greater tibial loading than level running.Running downhill at-10%and-15%resulted in reduced tibial loading compared to level running.There was no difference between+5%or-5%and level running.Conclusion:Running at faster speeds and uphill on gradients≥+10%increased internal tibial loading,whereas slower running and downhill running on gradients≥-10%reduced internal loading.Adapting running speed according to the gradient could be a protective mechanism,providing runners with a strategy to minimize the risk of tibial stress injuries.

关键词： Bending moments Gradient Musculoskeletal modeling Overuse injury Tibial stress Training factors

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Investigation of Projectile Impact Behaviors of Graphene Aerogel Using Molecular Dynamics Simulations

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 3047-3061页

作者： Xinyu Zhang Wenjie Xia Yang Wang Liang Wang Xiaofeng Liu Department of Engineering Mechanics Shanghai Jiao Tong UniversityShanghai200240China Department of Aerospace Engineering Iowa State UniversityAmesIA50011USA School of Materials Science and Engineering University of Science&Technology BeijingBeijing100083China Zernike Institute for Advanced Materials University of GroningenGroningen9747The Netherlands

Graphene aerogel(GA),as a novel solid material,has shown great potential in engineering applications due to its unique mechanical properties.In this study,the mechanical performance of GA under high-velocity projectile impacts is thoroughly investigated using full-atomic molecular dynamics(MD)simulations.The study results show that the porous structure and density are key factors determining the mechanical response of GA under impact loading.Specifically,the impact-induced penetration of the projectile leads to the collapse of the pore structure,causing stretching and subsequent rupture of covalent bonds in graphene sheets.Moreover,the effects of temperature on the mechanical performance of GA have been proven to be minimal,thereby highlighting the mechanical stability of GA over a wide range of temperatures.Finally,the energy absorption density(EAD)and energy absorption efficiency(EAE)metrics are adopted to assess the energy absorption capacity of GA during projectile penetration.The research findings of this work demonstrate the significant potential of GA for energy absorption applications.

关键词： Graphene aerogel molecular dynamics simulation impact response energy absorption