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Profiling elite male 100-m sprint performance:The role of maximum velocity and relative acceleration

journal of Sport and Health Science 2022年第1期11卷 75-84页

作者： Robin Healy Ian C.Kenny andrew j.harrison Department of Physical Education and Sport Sciences University of LimerickV94 T9PXIreland Department of Sport and Health Sciences Athlone Institute of TechnologyN37 HD68Ireland Health Research Institute University of LimerickLimerickV94 T9PXIreland

Purpose:This study aimed to determine the accuracy of a 4 split time modelling method to generate velocity-time and velocity-distance variables in elite male 100-m sprinters and subsequently to assess the roles of key sprint parameters with respect to 100-m sprint ***,this study aimed to assess the differences between faster and slower sprinters in key sprint variables that have not been assessed in previous ***:Velocity-time and velocity-distance curves were generated using a mono-exponential function from 4 split times for 82 male sprinters during major athletics *** race variables-maximum velocity,the acceleration time constant(τ),and percentage of velocity lost(vLoss)-were derived for each *** were divided into tertiles,based on 100-m time,with the first and third tertiles considered to be the faster and slower groups,respectively,to facilitate further ***:Modelled split times and velocities displayed excellent accuracy and close agreement with raw measures(range of mean bias was-0.2%to 0.2%,and range of intraclass correlation coefficients(ICCs)was 0.935 to 0.999)except for 10-m time(mean bias was 1.6%±1.3%,and the ICC was 0.600).The 100-m sprint performance time and all 20-m split times had a significant near-perfect negative correlation with maximum velocity(r≥-0.90)except for the 0 to 20-m split time,where a significantly large negative correlation was found(r=-0.57).The faster group had a significantly higher maximum velocity andτ(p<0.001),and no significant difference was found for vLoss(p=0.085).Conclusion:Coaches and researchers are encouraged to utilize the 4 split time method proposed in the current study to assess several key race variables that describe a sprinter’s performance capacities,which can be subsequently used to further inform training.

关键词： Deceleration Modelling Race phases Reaction time Split times

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Does the McNeill Alexander model accurately predict maximum walking speed in novice and experienced race walkers？

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journal of Sport and Health Science 2018年第3期7卷 372-377页

作者： andrew j.harrison Patrick G.Molloy Laura-Anne M.Furlong Department of Physical Education and Sport Sciences University of LimerickCastletroyLimerick V94 T9PXIreland School of Sport Exercise and Health Sciences Loughborough UniversityEpinalWayLoughboroughLeicestershire LEll 3TUUK

Background:Mathematical models propose leg length as a limiting factor in determining the maximum walking *** study evaluated the effectiveness of a leg length-based model in predicting maximum walking velocity in an applied race walking situation,by comparing experienced and novice race walkers during conditions where strictly no flight time(FT)was permitted and in simulated competition conditions(i.e.,FTjump Next system(8 m)was used to determine walking velocity,step frequency,step length,ground contact time,and FT during race walking over a range of *** were made between novice and experienced participants in predicted maximum velocity and actual velocities achieved with no flight and velocities with FT<40 *** technical effectiveness of the participants was assessed using the ratio of maximum velocity to predicted ***:In novices,no significant difference was found between predicted and maximum walking speeds without FT but there was a small 5.8%gain in maximum speed when FT≤40 *** experienced race walkers,there was a significant reduction in maximum walking speed compared with predicted maximum(p<0.01)and a 11.7%gain in maximum walking speed with FT<40 ***:Leg length was a good predictor of maximal walking velocity in novice walkers but not a good predictor of maximum walking speed in well-trained walkers who appear to have optimised their walking technique to make use of non-visible flight periods of less than 40 *** gain in velocity above predicted maximum may be a useful index of race walking proficiency.

关键词： Biomechanics Gait Mathematical modelling Race walking Sports technique Technique development

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Signaling events during initiation of arbuscular mycorrhizal symbiosis

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journal of Integrative Plant Biology 2014年第3期56卷 250-261页

作者： Alexa M.Schmitz Maria j.harrison Boyce Thompson Institute for Plant Research Plant Pathology and Plant-Microbe Biology Cornell University

Under nutrient-limiting conditions, plants will enter into symbiosis with arbuscular mycorrhizal （AM） fungi for the enhancement of mineral nutrient acquisition from the surrounding soil. AM fungi live in close, intracellular association with plant roots where they transfer phosphate and nitrogen to the plant in exchange for carbon. They are obligate fungi, relying on their host as their only carbon source. Much has been discovered in the last decade concerning the signaling events during initiation of the AM symbiosis, including the identification of signaling molecules generated by both partners. This signaling occurs through symbiosis-specific gene products in the host plant, which are indispensable for normal AM development. At the same time, plants have adapted complex mechanisms for avoiding infection by pathogenic fungi, including an innate immune response to general microbial molecules, such as chitin present in fungal cell walls. How it is that AM fungal colonization is maintained without eliciting a defensive response from the host is still uncertain. In this review, we present a summary of the molecular signals and their elicited responses during initiation of the AM symbiosis, including plant immune responses and their suppression.

关键词： Arbuscular mycorrhizal fungi chitin chitooligosaccharide cutin LysM MAMP-triggered immunity Myc-LCO Nod factor strigolactones symbiosis

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Regeneration and utilization of nutrients during collapse of a Mesodinium rubrum red tide and its influence on phytoplankton species composition

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Science China Earth Sciences 2018年第10期61卷 1384-1396页

作者： Yafeng ZHANG Xiuxian SONG Paul j.harrison Sheng LIU Zhiming YU jinjun KAN Peiyuan QIAN Hao LIU Kedong YIN School of Marine Sciences Sun Yat-Sen University Key Laboratory of Marine Ecology and Environmental Sciences Institute of Oceanology Chinese Academy of Sciences Department of Earth Ocean & Atmospheric Sciences University of British Columbia Key Laboratory of Tropical Marine Environmental Dynamics South China Sea Institute of Oceanology Chinese Academy of Sciences Microbiology Division Stroud Water Research Center 970 Spencer Road Division of Life Science Hong Kong University of Science and Technology

High-biomass red tides occur frequently in some semi-enclosed bays of Hong Kong where ambient nutrients are not high enough to support such a high phytoplankton biomass. These high-biomass red tides release massive inorganic nutrients into local waters during their collapse. We hypothesized that the massive inorganic nutrients released from the collapse of red tides would fuel growth of other phytoplankton species. This could influence phytoplankton species composition. We tested the hypothesis using a red tide event caused by Mesodinium rubrum(M. rubrum) in a semi-enclosed bay, Port Shelter. The red tide patch had a cell density as high as 5.0×10~5 cells L^(-1), and high chlorophyll a(63.71 μg L^(-1)). Ambient inorganic nutrients(nitrate:NO_3^-, ammonium: NH_4^+, phosphate: PO_4^(3-), silicate: SiO_4^(3-)) were low both in the red tide patch and the non-red-tide patch(clear waters outside the red tide patch). Nutrient addition experiments were conducted by adding all the inorganic nutrients to water samples from the two patches followed by incubation for 9 days. The results showed that the addition of inorganic nutrients did not sustain high M. rubrum cell density, which collapsed after day 1, and did not drive M. rubrum in the non-red-tide patch sample to the same high-cell density in the red tide patch sample. This confirmed that nutrients were not the driving factor for the formation of this red tide event, or for its collapse. The death of M. rubrum after day 1 released high concentrations of NO_3^-,PO_4^(3-), SiO_4^(3-), NH_4^+, and urea. Bacterial abundance and heterotrophic activity increased, reaching the highest on day 3 or 4, and decreased as cell density of M. rubrum declined. The released nutrients stimulated growth of diatoms, such as Chaetoceros affinis var. circinalis, Thalassiothrix frauenfeldii, and Nitzschia sp., particularly with additions of SiO_4^(3-) treatments, and other species. These results demonstrated that initiation of M. rubrum red tid

关键词： Red tides Species composition Nutrients Regeneration Mesodinium rubrum

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Defining strawberry shape uniformity using 3D imaging and genetic mapping

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Horticulture Research 2020年第1期7卷 1126-1138页

作者： Bo Li Helen M.Cockerton Abigail Wjohnson Amanda Karlström Eleftheria Stavridou Greg Deakin Richard j.harrison NIAB EMR East MallingKent ME196BJUK University of the West of England Bristol BS161QYUK NIAB Huntingdon RoadCambridge CB30LEUK

Strawberry shape uniformity is a complex trait,influenced by multiple genetic and environmental *** complicate matters further,the phenotypic assessment of strawberry uniformity is confounded by the difficulty of quantifying geometric parameters‘by eye’and variation between *** in-depth genetic analysis of strawberry uniformity has not been undertaken to date,due to the lack of accurate and objective ***,uniformity remains one of the most important fruit quality selection criteria for the development of a new *** this study,a 3D-imaging approach was developed to characterise berry shape *** show that circularity of the maximum circumference had the closest predictive relationship with the manual uniformity *** five or six automated metrics provided the best predictive model,indicating that human assessment of uniformity is highly ***,visual assessment of strawberry fruit quality in a multi-parental QTL mapping population has allowed the identification of genetic components controlling uniformity.A“regular shape”QTL was identified and found to be associated with three uniformity *** QTL was present across a wide array of germplasm,indicating a potential candidate for marker-assisted breeding,while the potential to implement genomic selection is explored.A greater understanding of berry uniformity has been achieved through the study of the relative impact of automated metrics on human perceived ***,the comprehensive definition of strawberry shape uniformity using 3D imaging tools has allowed precision phenotyping,which has improved the accuracy of trait quantification and unlocked the ability to accurately select for uniform berries.

关键词： straw breeding shape

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Diagnosis of Vocal Cord Paralysis in Anaesthesia

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journal of Donghua University(English Edition) 2011年第1期28卷 5-9页

作者：余炜曾孝平 HAMID GholamHosseini andrew Cameron MICHAEL harrison j Faculty of Information Engineering and Automation Kunming University of Science and Technology College of Communication Engineering Chongqing University Institute of Biomedical Technologies(IBTec) Auckland University of Technology Middlemore Hospital(Otahuhu) Auckland 1640New Zealand School of Medicine University of AucklandAuckland 1142New Zealand

Vocal cord paralysis can occur as a complication o surgery or anaesthesia,if permanent is a significant clinica *** detection is important to optimize the chance o repair,and avoid complications associated with an impaired *** algorithm to detect altered vocal cord function was presented based on wavelet packet analysis(WPA) and suppor vector machines(SVM),and compared with the Hoarseness Diagram method(HDm),which was reported as an objective voice quality evaluation approach and could be used for pathological voice *** using voice signals recorded from subjects before and after the procedure show high classification accuracy with the new algorithm,whereas HDm fails in the detection of a hoarse *** finding would help to develop a screening tool to detect the vocal structure damage during surgery.

关键词： vocal cord paralysis wavelet packet analysis(WPA) support vector machine(SVM) anaesthesia

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Amplicon-based metagenomics identified candidate organisms in soils that caused yield decline in strawberry

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Horticulture Research 2015年第1期2卷 201-213页

作者： Xiangming Xu Thomas Passey Feng Wei Robert Saville Richard j.harrison East Malling Research East MallingWest MallingKentME196BJUK

A phenomenon of yield decline due to weak plant growth in strawberry was recently observed in non-chemo-fumigated soils,which was not associated with the soil fungal pathogen Verticillium dahliae,the main target of ***-based metagenomics was used to profile soil microbiota in order to identify microbial organisms that may have caused the yield decline.A total of 36 soil samples were obtained in 2013 and 2014 from four sites for metagenomic studies;two of the four sites had a yield-decline problem,the other two did *** than 2000 fungal or bacterial operational taxonomy units(OTUs)were found in these *** abundance of individual OTUs was statistically compared for differences between samples from sites with or without yield decline.A total of 721 individual comparisons were statistically significant–involving 366 unique bacterial and 44 unique fungal *** on further selection criteria,we focused on 34 bacterial and 17 fungal OTUs and found that yield decline resulted probably from one or more of the following four factors:(1)low abundance of Bacillus and Pseudomonas populations,which are well known for their ability of supressing pathogen development and/or promoting plant growth;(2)lack of the nematophagous fungus(Paecilomyces species);(3)a high level of two non-specific fungal root rot pathogens;and(4)wet soil *** study demonstrated the usefulness of an amplicon-based metagenomics approach to profile soil microbiota and to detect differential abundance in microbes.

关键词： soil straw soils

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Mapping QTL associated with Verticillium dahliae resistance in the cultivated strawberry(Fragaria×ananassa)

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Horticulture Research 2015年第1期2卷 272-279页

作者： L Antanaviciute NŠurbanovski N harrison K j McLeary D W Simpson F Wilson D j Sargent R j.harrison East Malling Research New RoadEast MallingKent ME196BJUK Research and Innovation Centre Fondazione Edmund MachVia E.Mach 138010 San Michele all’Adige(TN)Italy

A biparental cross of octoploid strawberry segregating for resistance to Verticillium dahliae,the causative agent of Verticillium wilt,was screened under field conditions for three *** wilt scores were significantly associated with multiple QTL,which were mostly significant across all *** significantly associated with the traits were used to screen material with known wilt resistance and susceptibility phenotypes.A clear and statistically significant relationship was observed between resistant,tolerant and susceptible material and the total number of markers present in the different resistance *** field situations resistance QTL appear to behave in an additive *** markers are abundant in the cultivated strawberry germplasm indicating that,despite the large number of markers,clear genetic gain is possible through marker-assisted breeding.

关键词： straw Fragaria resistance

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Ammonia and greenhouse gas emissions from a subtropical wheat field under different nitrogen fertilization strategies

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journal of Environmental Sciences 2017年第7期29卷 196-210页

作者： Shuai Liu jim j.Wang Zhou Tian Xudong Wang Stephen harrison College of Resources and Environment Northwest A & F University School of Plant Environmental and Soil SciencesLouisiana State University Agricultural Center

Minimizing soil ammonia（NH_3） and nitrous oxide（N_2O） emission factors（EFs） has significant implications in regional air quality and greenhouse gas（GHG） emissions besides nitrogen（N） nutrient *** aim of this study was to investigate the impacts of different N fertilizer treatments of conventional urea,polymer-coated urea,ammonia sulfate,urease inhibitor（NBPT,N-（n-butyl） thiophosphoric triamide）-treated urea,and nitrification inhibitor（DCD,dicyandiamide）-treated urea on emissions of NH_3 and GHGs from subtropical wheat cultivation.A field study was established in a Cancienne silt loam *** growth season,NH_3 emission following N fertilization was characterized using active chamber method whereas GHG emissions of N_2O,carbon dioxide（CO_2）,and methane（CH_4） were by passive chamber *** results showed that coated urea exhibited the largest reduction（49%） in the EF of NH_3-N followed by NBPT-treated urea（39%） and DCD-treated urea（24%） over conventional urea,whereas DCD-treated urea had the greatest suppression on N_2O-N（87%） followed by coated urea（76%） and NBPT-treated urea（69%）.Split fertilization of ammonium sulfate-urea significantly lowered both NH_3-N and N_2O-N EF values but split urea treatment had no impact over one-time application of *** NBPT and DCD-treated urea treatments lowered CO_2-C flux but had no effect on CH_4-C ***,application of coated urea or urea with NPBT or DCD could be used as a mitigation strategy for reducing NH_3 and N_2O emissions in subtropical wheat production in Southern USA.

关键词： Ammonia Nitrous oxide Carbon dioxide Methane Nitrogen fertilization

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