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Predictors of residual force enhancement in voluntary contractions of elbow flexors

Journal of Sport and Health Science 2018年第3期7卷 318-325页

作者： Heiliane de Brito Fontana daiani de campos Raphael Luiz Sakugawa Biological Sciences Center Federal University of Santa CatarinaCampus Reitor Joao David Ferreira LimaFlorianopoilsSC 88040-900Brazil Biomechanic Laboratory Federal University of Santa CatarinaCampus Reitor Joao David Ferreira LimaFlorianopolisSC 88040-900Brazil

Background:The steady-state increase in muscle force generating potential following a lengthening contraction is called residual force enhancement(RFE).In this study,we aimed to test for differences in torque,electromyographic activity(EMG),and the associated neuromuscular efficiency(NME)between isometric voluntary contractions of elbow flexors preceded and not preceded by a lengthening *** dependence of such differences on(i)stretch amplitude,(ii)the region of the force-length(FxL)relationship where contraction occurs,and(iii)the individual's ability to produce(negative)work during the stretch was ***:Sixteen healthy adults participated in the *** flexor torque,angle,and biceps brachii EMG for purely isometric contractions(reference contractions)and for isometric contractions preceded by active stretches of 20°and 40°were measured at the ascending,plateau,and descending regions of subject-specific FxL *** contractions were performed in an isokinetic ***-factor(stretch×FxL region)repeated measures analysis of variance ANOVAs was used to analyze the effect of active stretch on EMG,torque,and NME across *** relationships between mechanical work during stretch-calculated as the torque-angular displacement integral-and the changes in EMG,torque,and NME were analyzed using Pearson ***:In general,torque,EMG,and NME following active stretches differed from the values observed for the purely isometric reference *** although the detailed effects of active stretch on torque and EMG differed between regions of the FxL relationship,NME increased by about 19%for all muscle *** to 30%of the interindividual variability in torque generating potential change in response to active stretching was accounted for by differences in(negative)work capacity between ***:Our results suggest that(i)RFE contributes to"flatten"the elbow flexor torque-angle relationship,favoring

关键词： Force-length History-dependent properties Neuromuscular efficiency Upper limb Voluntary contractions

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Residual force enhancement in human skeletal muscles:A systematic review and meta-analysis

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Journal of Sport and Health Science 2022年第1期11卷 94-103页

作者： daiani de campos Lucas B.R.Orssatto Gabriel S.Trajano Walter Herzog Heiliane de Brito Fontana Biomechanics Laboratory Federal University of Santa CatarinaFlorianopolis 88040-001Brazil Faculty of Health School of Exercise and Nutrition SciencesQueensland University of TechnologyBrisbane QLD 4030Australia Human Performance Laboratory Faculty of KinesiologyUniversity of CalgaryAB T2N 1N4Canada School of Biological Sciences Federal University of Santa CatarinaFlorianopolis 88040-900Brazil

Objective:We reviewed and appraised the existing evidence of in vivo manifestations of residual force enhancement in human skeletal muscles and assessed,through a meta-analysis,the effect of an immediate history of eccentric contraction on the subsequent torque capacity of voluntary and electrically evoked muscle ***:Our search was conducted from database inception to May *** information was extracted from,and quality was assessed for,45 ***-analyses and metaregressions were used to analyze residual torque enhancement and its dependence on the angular amplitude of the preceding eccentric ***:Procedures varied across studies with regards to muscle group tested,angular stretch amplitude,randomization of contractions,time window analyzed,and verbal *** capacity in isometric(constant muscle tendon unit length and joint angle)contractions preceded by an eccentric contraction was typically greater compared to purely isometric contractions,and this effect was greater for electrically evoked muscle contractions than voluntary *** torque enhancement differed across muscle groups for the voluntary contractions,with a significant enhancement in torque observed for the adductor pollicis,ankle dorsiflexors,ankle plantar flexors,and knee extensors,but not for the elbow and knee ***-regressions revealed that the angular amplitude of the eccentric contraction(normalized to the respective joints full range of motion)was not associated with the residual torque enhancement ***:There is evidence of residual torque enhancement for most,but not all,muscle groups,and residual torque enhancement is greater for electrically evoked than for voluntary *** to our hypothesis,and contrary to generally accepted findings on isolated muscle preparations,residual torque enhancement in voluntary and electrically evoked contractions does not seem to depend on the angular ampli

关键词： Cross-bridge theory Eccentric contraction Force-length relationship Isometric force Muscle properties

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An overview on nucleation theories and models

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Journal of Rare Earths 2019年第10期37卷 1015-1022页

作者： Marcos Flavio de campos Jose Adilson de Castro department of Mechanical Engineering Federal Fluminense University

Several different models for coercivity are discussed. There are two main situations: i) nanocrystalline magnets, with grain size bellow the single domain particle size, and ii) magnets with grain size above single domain particle size. The described theories and models are general, and can be applied in either NdFeB magnets, SmFeCoCuZr or strontium ferrite magnets. The spring effect observed in isotropic nanocrystalline magnets can be explained with the Stoner-Wohlfarth model. Modifications of the StonerWohlfarth model are necessary to take into account the effect of interaction between grains. When the grain size is above the single domain size, energy considerations show that nucleation should occur at the surface of grains. Nucleation is interpreted as a two-step process, where domain wall displacement occurs for grain size above single domain size, after a nucleus is first formed. The effect of grain size on the coercive field is discussed.

关键词： Coercivity Nucleation Grain size Spring effect Nd-Fe-B Permanent magnet

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Hypertonic saline:a brief overview of hemodynamic response and anti-inflammatory properties in head injury

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Neural Regeneration Research 2015年第12期10卷 1938-1939页

作者： Matheus Fernandes de Oliveira Fernando campos Gomes Pinto department of Neurosurgery Hospital do Servidor Público Estadual de S?o PauloIAMSPE Division of Functional Neurosurgery of the Institute of Psychiatry Hospital das ClínicasUniversidade de S?o Paulo

Hypertonic saline （HS） has been applied in several med- ical areas such as pneumology （asthma, cystic fibrosis and bronchiolytis）, endocrinology （hyponatremia） and especially in emergency medicine, in traumatic and in- flammatory/infectious disorders. It may be composed of 3% or 7.5% sodium chlorate. By far, 3% solution is the most widely studied and used solution （Pinto et al., 2006, 2015; dekker et al., 2014; Gantner et al., 2014; Shein et al., 2014）.

关键词： TBI Hypertonic saline head

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Lessons and challenges for the recycling sector of Brazil from the pandemic outbreak of COVID-19

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Waste Disposal and Sustainable Energy 2021年第2期3卷 145-154页

作者： Ronei de Almeida Roberta Guimarães de Souza Juacyara Carbonelli campos School of Chemistry Inorganic Processes DepartmentFederal University of Rio de Janeiro.AvAthos da Silveira Ramos 149Ilha do FundãoRio de Janeiro 21941-909Brazil CoClima Av.Alfonso Balthazar da Silveira 339Recreio dos BandeirantesRio de Janeiro 22790-710Brazil

The 2019-2020 coronavirus pandemic imposed unprecedented challenges in Brazilian governance sectors,mostly in the waste management ***,we analyse the main challenges of the recycling sector in Brazil to cope with this *** difficulties during the pandemic outbreak of COVID-19 can help improve waste recycling in the post-pandemic period in Brazil and other developing nations that face similar *** current pandemic exposed the deficiencies of this system,and some important lessons can be *** are drawn to advance the proper management of recyclables in the *** Government must increase total investments in the recycling industry’s infrastructure and support local recycling initiatives during a public health crisis and *** sum,this paper strengthens the idea that waste segregation at the source and selective collection will not be sufficient without massive investments in the recycling sector’s *** future challenge includes strengthening the economic markets for recycled materials.

关键词： Coronavirus developing countries Informal sector Recycling Selective collection Waste management

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Old climatically-buffered infertile landscapes(OCBILs):more than harsh habitats,Atlantic Forest inselbergs can be drivers of evolutionary diversity

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Journal of Mountain Science 2022年第9期19卷 2528-2543页

作者： Felipe de CARVALHO ARAÚJO Natália de AGUIAR-campos Cleber Rodrigo de SOUZA Eduardo de Paiva PAULA Rubens Manoel dos SANTOS Laboratory of Phytogeography and Evolutionary Ecology Department of Forest SciencesFederal University of LavrasLavrasMinas GeraisBrazil

Granite-gneiss rock outcrop inselbergs are ancient stable ecosystems with old,climaticallybuffered infertile landscapes(OCBILs).Although inselbergs provide key ecosystem services,little is done for their conservation and,so far,a lot of their unknown evolutionary history has already been lost by human *** a fine-scale approach,here we tested if habitat and environmental filtering(the inselberg’s harshness)affect the evolutionary diversity of an Atlantic Forest inselberg in *** recorded all trees with a diameter at breast height≥5cm in 20 plots in four habitat types(total sampled area of 0.8 hectares),from highest to lowest:island,hillside,foothill,and semideciduous forest(matrix).We also collected soil samples for chemical,textural and physical soil *** fitted linear models to test the effects of soil and habitat on plotlevel metrics of phylogenetic diversity and structure,lineage diversity,phylogeneticβ-diversity,and evolutionary *** found that the upper inselberg habitats contain a distinct set of ancient,closely related,harsh-tolerant lineages,as well as a subset of lineages that persist under harsh conditions with a certain degree of water *** inferior inselberg habitats harbor higher lineage diversity than expected by *** strongly predicted evolutionary *** concluded that soil depth,slope,nutrients and texture(environmental filtering)and habitat types and topography(habitat filtering)shape the evolutionary history contained in fine-scale inselberg habitats,which should encourage the conservation of these ancient ecosystems.

关键词： Phylogenetic diversity Atlantic Forest Niche conservatism Environmental filters Soil fertility Terrestrial Island

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Ziegler-Nichols Customization for Quadrotor Attitude Control under Empty and Full Loading Conditions

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Computer Modeling in Engineering & Sciences 2020年第10期125卷 65-75页

作者： Ivan Paulo Canal Manuel Martin Pérez Reimbold Maurício de campos Federal Institute of Education Science and Technology FarroupilhaCampus PanambiPanambiBrazil Regional University of the Northwest of the State of Rio Grande do Sul IjuíBrazil

An aircraft quadrotor is a complex control system that allows for great flexibility in *** multirotor aerial systems such as quadrotors is complex because the variables involved are not always available,known,and *** inclusion of payload changes the dynamic characteristics of the aircraft,making it necessary to adapt the control system for this *** the various control methods that have been investigated,proportional-integralderivative(PID)control offers good results and simplicity of application;however,achieving stability and high performance is challenging,with the most critical task being tuning the controller *** Ziegler-Nichols(ZN)theory was used to tune the controller gains for pitch and roll attitude command;however,the performance results were not *** response of this system was refined,resulting in an improvement in the reference tracking and the rejection of *** particular refinement was applied to the quadrotor,and via a reverse calculation,the parameters that allow the tuning of PID gains were obtained,based on *** particularization of the ZN theory applied to a quadrotor with and without a load(termed ZNAQ and ZNAQL,respectively)is proposed and results in a significant improvement in the control system response performance(up to 75%),demonstrating that ZNAQ and ZNAQL are valid for tuning the controller PID gains and are more efficient than the original ZN theory approach.

关键词： Ziegler-Nichols quadrotor control PID tuning multirotor

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Patterns of species richness and beta diversity of vascular plants along elevation gradient in Brazilian páramo

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Journal of Mountain Science 2023年第7期20卷 1911-1920页

作者： CORdeIRO Anais de Almeida campos KLANdeRUD Kari VILLA Pedro Manuel NERI Andreza Viana Federal University of Viçosa Department of Plant BiologyLaboratory of Ecology and Evolution of PlantsCampus Viçosa36570-900Viçosa-MGBrazil Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life SciencesP.O.Box 5003N-1432ÅsNorway Biodiversity Conservation Association 7101Puerto AyacuchoEstado AmazonasVenezuela

Understanding the relationships between plant diversity and the environment is an important step towards conservation of species and *** this study,we hypothesize that community species richness decreases and species composition change along the elevation gradient,with a greater contribution of species turnover than nestedness to beta *** surveyed plant species in 300 plots(1 m×1 m)in four elevational bands(2100 m,2300m,2500 m,and 2700 m)in the CaparaóNational Park,Southeastern *** samples presented a great number of species(97 spp.,59 genera,27families),however,74%of the species were considered rare with their relative abundance beingdetected two distinct communities with few species in *** transition between the two communities occurred at 2500 m,and this elevation band also had the highest species richness in total.A non-metric multidimensional scaling(NMDS)showed floristic differences between the bands even though they had similar *** 89%of the plot pairs,using pairwise comparison of species composition,only half of the species that occurred in one did occur in the other *** dissimilarity among the plots and elevational band reflects a significant contribution of spatial species turnover to the species richness and beta diversity on the Caparaó*** diversity increased with spatial scale(from plot to elevational-band).The dissimilarity(βSOR=0.907)in the area was due almost exclusively to spatial species turnover(βSIM=0.879),with very low contribution of species nestedness(βSNE=0.028).Our research showed that species richness does not decrease with elevation in the study area,but the floristic composition *** clear distinction of species along the gradient show that spatial species turnover is the major diversitygenerating process in the studied area.

关键词： High altitude grassland Species turnover Partitioning diversity Campo de altitude Tropical mountains

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Litter decomposition and nutrient release for two tropical N-fixing species in Rio de Janeiro,Brazil

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Journal of Forestry Research 2022年第2期33卷 487-496页

作者： David Pessanha Siqueira Giovanna campos Mamede Weiss de Carvalho JoséGabriel de Souza Silva Marcos Vinicius Winckler Caldeira deborah Guerra Barroso Laboratório de Fitotecnia Universidade Estadual do Norte Fluminense Darcy RibeiroAvenida Alberto Lamego2000Campos dos GoytacazesRio de JaneiroBrazil departamento de Ciências Florestais e da Madeira Universidade Federal do Espírito SantoAvenida Governador Lindenberg316Jerônimo MonteiroEspírito SantoBrazil department of Geosciences and Natural Resources Management University of CopenhagenRolighedsvej 23Frederisksberg CDenmark

Litter production and decomposition are critical to forest productivity,nutrient cycling,and carbon seques-tration in tropical woody ***,nutrient release and leaf litter stoichiometry in tropical legume tree plantations over the long term after outplanting are poorly understood or even *** improving our under-standing of the pattern of changes in the decomposition of N-fixing leaf litters and their possible impact on carbon stor-age,we measured litter production,mass loss and nutrient release for 240 d during litter decomposition for two tropical legume tree species(Plathymenia reticulata and Hymenaea courbaril),in Rio de Janeiro,*** production for *** was 5.689 kg ha^(−1) a^(−1) and 3.231 kg ha^(−1) a^(−1) for *** patterns of mass loss rates were similar;however,nutrient release was greater for ***,while *** showed immobilization of nutrients,especially for N,which increased by almost 20%in the early phase of decomposition followed by gradual *** from the N-fixing species did differ in nutrient chemistries over time,which was not surprising given that initial nutrient concentrations varied broadly,except for C and *** of the nutrient concentrations increased as the remaining litter mass decreased in both species,except for C and *** C:N and N:P ratios differed between the species,but N:P did not correlate to mass *** species had N-rich leaves,but *** decomposition was very likely P-limited,while *** seemed to be co-limited by N and *** results showed different patterns in nutrient release and the stoichi-ometry involved in the decomposition dynamics of the two tropical N-fixing species,even though they have similar litter decay *** species,but especially ***,may help re-establish nutrient cycling in disturbed ecosystems.

关键词： Nutrient dynamics Legume species Litter chemistry Ecological stoichiometry Tropical forest

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Vegetative propagation of Apuleia leiocarpa(Vogel)***

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Journal of Forestry Research 2022年第2期33卷 455-462页

作者： JoséGabriel de Souza Silva Diêgo Faustolo Alves Bispo David Pessanha Siqueira Giovanna campos Mamede Weiss de Carvalho deborah Guerra Barroso Laboratório de Fitotecnia Universidade Estadual do Norte Fluminense Darcy RibeiroAvenida Alberto LamegoCampos dos GoytacazesRJ 2000Brazil

Apuleia leiocarpa is an environmentally and economically significant Atlantic Forest species threat-ened by ongoing *** vegetative propagation of the species could be a step forward to enable implanta-tion of clonal seed orchards and multiplication of selected trees but remains unknown to *** study assessed the mini-cutting technique for propagation of *** and determined the time required for rooting and viable mini-cutting type and *** results show that it is possible to propagate *** with mini-cuttings derived from mini-stumps produced with seeds;the mini-stumps pre-sented regrowth capacity and remained constantly produc-tive for 1 year;10-cm *** mini-cuttings should remain under misting conditions for at least 40 days,and the vegetative propagation of *** with intermediate 7-to 10-cm mini-cuttings resulted in more vigorous clonal seedlings than smaller mini-cuttings.

关键词： Mini-cutting Tropical woody species Adventitious rooting Fabaceae

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