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Upper limb assessment in tetraplegia: clinical, functional and kinematic correlations

CACHO, Enio Walker Azevedo; OLIVEIRA, Roberta de; ORTOLAN, Rodrigo L.; VAROTO, Renato; CLIQUET JR., Alberto
Fonte: LIPPINCOTT WILLIAMS & WILKINS Publicador: LIPPINCOTT WILLIAMS & WILKINS
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.42%
The aim of this study was to correlate clinical and functional evaluations with kinematic variables of upper limp reach-to-grasp movement in patients with tetraplegia. Twenty chronic patients were selected to perform reach-to-grasp kinematic assessment using a target placed at a distance equal to the arm`s length. Kinematic variables (hand peak velocity, movement time, percent time-to-maximal velocity, index of curvature, number of peaks, and joint range of motion) were correlated to clinical (Standard Neurological Classification of Spinal Cord Injury-American Spinal Injury Association) and functional [Functional Independence Measure (FIM) and Spinal Cord Independence Measure II (SCIM II)) evaluation scores. Twenty control participants were also selected to obtain normal reference parameters. There was a positive correlation between total motor index and FIM (r=0.6089; P=0.0044) and SCIM II (r=0.5229; P=0.018). Both functional scores showed positive correlation with each other (r=0.8283; P<0.0001). A correlation was also observed between the right and left motor indices, the motor AM, and the SCIM II in most of the reach-to-grasp kinematic variables studied (hand peak velocity, movement time, index of curvature, and number of peaks). In contrast...

Comparação entre julgamento tradicional e avaliação cinemática do salto de cavalos da raça Brasileiro de Hipismo; Comparison between traditional judgement and jumping kinematic evaluation of Brazilian Sport horses

Miyashiro, Patricia
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 14/06/2012 PT
Relevância na Pesquisa
36.31%
O objetivo do presente trabalho foi descrever as características cinemáticas do salto de cavalos da raça Brasileiro de Hipismo, avaliar o julgamento realizado pelos juízes durante uma competição de salto em liberdade e comparar essas avaliações. Foram utilizados 13 equinos da raça Brasileiro de Hipismo, machos não castrados (40,15±4,24 meses, 491,1±40,89 kg). Os animais foram filmados saltando um obstáculo oxer durante uma competição de saltos em liberdade. Trajetórias do centro de massa corporal (CM) foram calculadas através da posição de pontos anatômicos que foram rastreados manualmente desde a decolagem até o pouso. Dessa trajetória, variáveis biomecânicas foram calculadas: velocidade vertical e horizontal, ângulos da velocidade e do deslocamento do CM na decolagem, altura máxima, deslocamento vertical e horizontal do CM, altura e fração de encurtamento dos membros sobre o obstáculo. Um polinômio de segunda ordem foi calculado através da trajetória do CM para obter três constantes com base na equação resultante. Os cavalos foram avaliados por três juízes: medidas zoométricas, funcionalidade, morfologia, salto, genealogia e modelo de garanhão. As notas de julgamento são consistentes entre si...

Comparação das variáveis cinemáticas, eletromiográficas e do conusmo de oxigênio da corrida no triathlon com uma corrida prolongada e uma corrida isolada; Comparison of kinematic and electromyographic variables and oxygen uptake of the triathlon running with a prolonged run and an isolated run

Fraga, Carina Helena Wasem
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
46.39%
A corrida representa um importante segmento do triathlon, sendo precedida pela prova de ciclismo. A compreensão dos efeitos do ciclismo sobre o desempenho da corrida, portanto, se torna indispensável para a otimização dos resultados finais de uma prova. O objetivo desse estudo foi comparar as variáveis cinemáticas, eletromiográficas e o consumo de oxigênio da corrida no triathlon com àquelas de uma corrida isolada e de uma corrida prolongada. As seguintes variáveis foram avaliadas no presente estudo: (1) freqüência e amplitude de passada; (2) o valor RMS (root mean square) médio do sinal EMG dos músculos bíceps femoral, reto femoral, vasto lateral, gastrocnêmio medial e tibial anterior; e, (3) o VO2. Participaram desse estudo nove triatletas do sexo masculino. O protocolo de avaliação foi realizado em três etapas: (1) teste para obtenção do VO2 máx, realizado em esteira ergométrica; (2) teste que envolveu a sucessão ciclismo-corrida da prova de triathlon (CT), com 40 km de ciclismo, seguidos de10 km de corrida – em um contexto de prova simulada; e (3) teste de corrida prolongada (CP), em que o atleta correu o tempo correspondente aos 40 km de ciclismo somado a 10 km de corrida. Os primeiros 10 km dessa corrida prolongada constituíram a corrida isolada (CI). Os dados cinemáticos...

Relação entre economia de corrida e variáveis biomecânicas em corredores fundistas; Relationship between running economy and biomechanical variables in distance runners

Tartaruga, Marcus Peikriswili
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
56.4%
O objetivo do presente estudo foi analisar o comportamento de 15 variáveis cinemáticas (tempo de passada, tempo de suporte, tempo de balanço, comprimento de passada, comprimento de passada relativo, freqüência de passada, ângulos do joelho e tornozelo no foot strike e no take-off, máxima flexão do tronco e máxima flexão do joelho na fase de suporte, amplitude angular do cotovelo durante a passada, máxima pronação da parte posterior do pé e amplitude vertical do centro de massa) e 8 variáveis neuromusculares (ativação elétrica muscular do reto femoral, vasto lateral, semitendinoso e bíceps femoral - porção curta – nas fases de suporte e balanço) da corrida, correlacionando-as com a economia de corrida (ECO). Dezesseis homens (idade: 27+1 anos; consumo máximo de oxigênio (VO2máx): 56,4+4,8 ml.kg-1.min), corredores fundistas com experiência em provas de 10.000 metros, realizaram um teste submáximo de corrida em esteira rolante na velocidade de 16 km.h-1 correspondente a uma intensidade média de 10,7% abaixo do limiar anaeróbio (LA) e a uma velocidade média de 11,1% abaixo da velocidade no LA. Foi utilizado um ergoespirômetro portátil para registro do consumo submáximo de oxigênio (VO2submáx) e para o registro das variáveis cinemáticas e neuromusculares da corrida...

Chewing in Temporomandibular Disorder Patients: An Exploratory Study of an Association With Some Psychological Variables

Brandini, Daniela A.; Benson, Janet; Nicholas, Michael K.; Murray, Greg M.; Peck, Christopher C.
Fonte: Quintessence Publishing Co Inc Publicador: Quintessence Publishing Co Inc
Tipo: Artigo de Revista Científica Formato: 56-67
ENG
Relevância na Pesquisa
36.25%
Aims: To compare kinematic parameters (ie, amplitude, velocity, cycle frequency) of chewing and pain characteristics in a group of female myofascial temporomandibular disorder (TMD) patients with an age-matched control female group, and to study correlations between psychological variables and kinematic variables of chewing. Methods: Twenty-nine female participants were recruited. All participants were categorized according to the Research Diagnostic Criteria for TMD (RDC/TMD) into control (n = 14, mean age 28.9 years, SD 5.0 years) or TMD (n = 15, mean age 31.3 years, SD 10.7) groups. Jaw movements were recorded during free gum chewing and chewing standardized for timing. Patients completed the Depression, Anxiety, and Stress Scales (DASS-42), the Pain Catastrophizing Scale (PCS), the Fear of Pain Questionnaire-III (FPQ-III), and the Pain Self-Efficacy Questionnaire (PSEQ). Statistical analyses involved evaluation for group differences, and correlations between kinematic variables and psychological questionnaire scores (eg, depression, anxiety, stress) and pain intensity ratings. Results: Velocity and amplitude of standardized (but not free) chewing were significantly greater (P < .05) in the TMD group than the control group. There were significant (P < .05) positive correlations between pain intensity ratings and velocity and amplitude of standardized chewing but not free chewing. There were significant (P < .05) positive correlations between depression and jaw amplitude and stress and jaw velocity for standardized but not free chewing. Conclusion: This exploratory study has provided data suggesting that psychological factors...

Association between energy cost of walking, muscle activation, and biomechanical parameters in older female fallers and non-fallers

Marques, Nise Ribeiro; Laroche, Dain Patrick; Hallal, Camilla Zamfolini; Crozara, Luciano Fernandes; Morcelli, Mary Hellen; Karuka, Aline Harumi; Navega, Marcelo Tavella; Gonçalves, Mauro
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 330-336
ENG
Relevância na Pesquisa
46.21%
Objective: To determine the nervous activation, muscle strength, and biomechanical parameters that influence the cost of walking in older fallers and non-fallers. Methods: Maximal voluntary isokinetic torque was measured for the hip, knee and ankle of older women. Oxygen consumption was measured at rest and during 8 min of walking at self-selected speed. An additional minute of walking was performed to collect kinematic variables and the electromyographic signal of trunk, hip, knee, and ankle muscles, which was analyzed by the linear envelope. Cost of walking was calculated by subtracting resting body mass-normalized oxygen consumption from walking body mass-normalized oxygen consumption. Stride time and length, and ankle and hip range of motion were calculated from kinematic data. Findings: Older adult fallers had 28% lower knee extensor strength (p = 0.02), 47% lower internal oblique activation at heel contact (p = 0.03), and higher coactivation between tibialis anterior and gastrocnemius lateralis in each of the gait phases (p < 0.05). For fallers, a higher activation of gluteus maximus was associated with a higher cost of walking (r = 0.55, p < 0.05 and r = 0.71, p < 0.01, before and after heel contact, respectively). For non-fallers...

Avaliação da extremidade superior de tetraplégicos : correlações clínicas, funcionais e cinemáticas; Upper limb assessment in tetraplegia : clinical, functional and kinematic correlations

Enio Walker Azevedo Cacho
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 24/08/2010 PT
Relevância na Pesquisa
46.35%
Vários são os instrumentos de avaliação dedicados aos tetraplégicos. A compreensão de suas relações é de fundamental importância para o desenvolvimento e elaboração de abordagens terapêuticas voltadas à reabilitação da extremidade superior desses indivíduos. Assim, o objetivo deste estudo foi analisar as correlações entre as avaliações clínicas, funcionais e cinemáticas da extremidade superior durante os movimentos de alcance-preensão em tetraplégicos. Vinte tetraplégicos crônicos e vinte participantes controles foram selecionados para o estudo. Os instrumentos utilizados para a avaliação foram: o padrão de classificação da Associação Americana de Lesão Medular – ASIA, a Medida de Independência Funcional – MIF, a Mensuração de Independência da Medula espinhal – SCIM II, e a avaliação cinemática do movimento de alcance-preensão. Foram utilizadas as seguintes variáveis cinemáticas: deslocamento anterior do tronco e protração do ombro, amplitude articular do ombro, cotovelo e punho nos planos sagital e horizontal, índice de curvatura, pico de velocidade máxima, razão do pico de velocidade máxima, tempo de movimento e número de picos. O deslocamento anterior do tronco, protração do ombro e as amplitudes articulares do ombro e cotovelo não apresentaram diferenças significativas entre os tetraplégicos e os controles. Apenas a amplitude de flexoextensão do punho foi significativamente maior em tetraplégicos. Os movimentos dos tetraplégicos foram mais lentos...

Análise cinemática 3D da corrida de 100m por videogrametria; 3D kinematic analysis of the 100m sprint using a video-based system

Natália de Almeida Rodrigues
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 30/01/2014 PT
Relevância na Pesquisa
36.37%
A análise cinemática da corrida visa descrever o movimento de atletas por meio da quantificação de variáveis permitindo identificar padrões de movimento e assimetrias entre os membros com a finalidade de melhorar o desempenho ou prevenir e tratar lesões. Entretanto, a prova dos 100m rasos tem sido estudada freqüentemente com volumes reduzidos de aquisição e com a avaliação de poucos passos dentro de fases específicas da corrida, sendo então necessário propor métodos mais específicos. Assim, o objetivo deste trabalho foi propor a análise cinemática tridimensional da corrida 100m por videogrametria. O objetivo específico da análise consistiu em: a) descrever a trajetória do centro de massa (CM) e obter as variáveis cinemáticas (comprimento de passo, largura de passo, ângulo de ataque e componente vertical do CM) dos atletas em todas as fases da corrida (aceleração, manutenção e desaceleração), e b) avaliar o método. Foi avaliada uma corrida de cada um dos cinco corredores velocistas, do sexo masculino e de nível nacional. Doze câmeras foram distribuídas ao longo da pista formando três regiões e duas áreas de intersecção: a região 1 (30m x 1.37m x 2.32m), a região 2 (30m x 1.37m x 2.32m) e a região 3 (50m x 1.37m x 2...

Motor co-ordinates in primate red nucleus: preferential relation to muscle activation versus kinematic variables.

Miller, L E; Houk, J C
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 15/10/1995 EN
Relevância na Pesquisa
46.15%
1. Magnocellular red nucleus (RNm) neurones (n = 158) were recorded from two macaque monkeys during a tracking task using one of six single-degree-of-freedom manipulanda. This task allowed us to study discrete movements about most of the joints of the arm. Single-unit, kinematic and electromyographic (EMG) signals from ten to twenty muscles of the upper limb were collected for approximately 2 min while the monkey used a given manipulandum. Movements about different joints were studied by switching among manipulanda. 2. Cross-correlation functions were calculated between RNm discharge rate and the kinematic variables, position and velocity, and between RNm and each of the EMG signals. Statistically significant cross-correlation peaks were found in 24% of the position correlations, 22% of the velocity correlations and 32% of the EMG correlations. The highest correlations were for EMG, reaching above 0.60. The peak correlation provided an effective means of identifying neurones with strong functional relations to one or more movements and/or muscles. These could then be analysed in detail, on a trial-by-trial basis. 3. The similarity between the dynamics of EMG and velocity signals of many highly practised movements makes it difficult to determine which might be the more likely target of RNm control. Therefore...

Kinematic Structure at the Early Flight Position in Ski Jumping

Vodičar, Janez; Čoh, Milan; Jošt, Bojan
Fonte: Akademia Wychowania Fizycznego w Katowicach Publicador: Akademia Wychowania Fizycznego w Katowicach
Tipo: Artigo de Revista Científica
Publicado em 30/12/2012 EN
Relevância na Pesquisa
36.27%
The purpose of our research was to establish the variability of correlation between the length of the jumps and selected multi-item kinematic variables (n=9) in the early flight phase technique of ski jumping. This study was conducted on a sample of elite Slovenian ski jumpers (N=29) who participated in the experiment on a jumping hill in Hinterzarten, Germany (HS95m) on the 20th of August, 2008. The highest and most significant correlations (p=0.01) with the length of the ski jump were found in the multi-item variable height of flying, which was also expressed with the highest level of stability of the explained total variance (TV) on the first factor (TV=69.13%). The most important characteristic of the aerodynamic aspect of early flight was the variable angle between the body chord and the horizontal axis with significantly high correlations (p<0.05). The stability of that aerodynamic factor was very high (TV=65.04%). The results were essentially similar for the multi-item variable angle between left leg and the horizontal axis (TV=61.88%). The rest of the multi-item kinematic variables did not have significant correlations with the multi-item variable length of jump. Only two more variables, the angle between the upper body and the horizontal plane (TV=53.69%)...

Kinematic Variables Evolution During a 200-m Maximum Test in Young Paddlers

Vaquero-Cristóbal, Raquel; Alacid, Fernando; López-Plaza, Daniel; Muyor, José María; López-Miñarro, Pedro A.
Fonte: Akademia Wychowania Fizycznego w Katowicach Publicador: Akademia Wychowania Fizycznego w Katowicach
Tipo: Artigo de Revista Científica
Publicado em 08/10/2013 EN
Relevância na Pesquisa
46.39%
The objective of this research was to determine the kinematic variables evolution in a sprint canoeing maximal test over 200 m, comparing women and men kayak paddlers and men canoeists. Speed evolution, cycle frequency, cycle length and cycle index were analysed each 50 m section in fifty-two young paddlers (20 male kayakers, 17 female kayakers and 15 male canoeists; 13–14 years-old). Recordings were taken from a boat which followed each paddler trial in order to measure the variables cited above. Kinematic evolution was similar in the three categories, the speed and cycle index decreased through the test after the first 50 m. Significant differences were observed among most of the sections in speed and the cycle index (p<0.05 and <0.01, respectively). Cycle length remained stable showing the lowest values in the first section when compared with the others (p<0.01). Cycle frequency progressively decreased along the distance. Significant differences were identified in the majority of the sections (p<0.01). Men kayakers attained higher values in all the variables than women kayakers and men canoeists, but only such variables as speed, cycle length and cycle index were observed to be significantly higher (p<0.01). Moreover, lower kinematic values were obtained from men canoeists. The study of the evolution of kinematic variables can provide valuable information for athletes and coaches while planning training sessions and competitions.

Body Composition and Kinematic Analysis of the Grab Start in Youth Swimmers

Alptekin, Ahmet
Fonte: Akademia Wychowania Fizycznego w Katowicach Publicador: Akademia Wychowania Fizycznego w Katowicach
Tipo: Artigo de Revista Científica
Publicado em 10/10/2014 EN
Relevância na Pesquisa
36.39%
The purposes of this study were to compare the kinematic variables in youth swimmers during the grab start between sexes and to investigate the relationship between body composition and kinematic variables of the participants. Six female (Mage = 13.71 ± 0.49 yrs) and seven male (Mage = 14.00 ± 1.07 yrs) swimmers participated in this study. All participants were required to perform grab start tests in random order (three trials by each participant), while the best attempt was analyzed. Nineteen kinematic parameters consisting of block time, flight time, flight distance, total time, total distance, horizontal and vertical displacement of the center of mass (CM) at take-off, horizontal and vertical displacement of the CM at entry, height of take-off and entry, relative height of take-off, horizontal and vertical velocity of the CM at take-off, horizontal and vertical velocity of the CM at entry, angle of take-off, angle of entry and angle of knee at block were analyzed. Out of the 19 evaluated kinematic parameters, a statistical difference between the female and male group was found only in the total distance. Therefore, both female and male groups are considered as only one group and merged after analyzing the results. Statistical analysis showed positive and negative correlations between horizontal / vertical velocity of CM at take-off and several kinematic variables (e.g. angle of entry (rhorizontal = −.868...

Kinematic analysis of forelimb and hind limb joints in clinically healthy sheep

Faria, Luis G.; Rahal, Sheila C.; Agostinho, Felipe S.; Minto, Bruno W.; Matsubara, Lidia M.; Kano, Washington T.; Castilho, Maira S.; Mesquita, Luciane R.
Fonte: Biomed Central Ltd Publicador: Biomed Central Ltd
Tipo: Artigo de Revista Científica Formato: 1-5
ENG
Relevância na Pesquisa
36.32%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Processo FAPESP: 2012/02173-7; Background: Variations associated with sex, age, velocity, breed and body geometry should be considered in the determination of kinematic parameters for a gait considered normal.Therefore, this study aimed to evaluate kinematic patterns of forelimbs and hind limbs in clinically normal sheep from two different age groups walking at a constant velocity. The hypothesis was that the age may influence sagittal plane kinematic patterns. Fourteen clinically healthy female sheep were divided into Group 1 - seven animals aged from 8 to 12 months, and Group 2 - seven animals aged above 5 years. Before starting data collection, the sheep were trained to be conducted for walking in a pre-determined space at constant velocity. A minimum of 5 valid trials were obtained from the right and left sides of each sheep. Data were analyzed by use of a motion-analysis program. Flexion and extension joint angles (maximum, minimum, displacement), and angular velocity (maximum, minimum) were determined for the shoulder, elbow, carpal, hip, stifle, and tarsal joints.Results: Within each group...

Kinematic analysis and upper limb contributions to racket head velocity of elite tennis players in tennis forehand drive winner.

Pedro, Bruno Miguel Machado
Fonte: Universidade Técnica de Lisboa Publicador: Universidade Técnica de Lisboa
Tipo: Dissertação de Mestrado
Publicado em //2015 ENG
Relevância na Pesquisa
46.1%
Mestrado em Treino de Alto Rendimento; The aim of the present study was to quantify and compare kinematic variables and their contributions to the racket head speed in tennis forehand winner, in the cross court and inside out direction. Mini inertial sensors (Xsens MVN) of motion capture, recorded kinematic data of six elite tennis players (ATP professionals). Linear velocity of the racket and ball were captured with a high speed video camera. Results indicate that the direction of the shot is influenced by the internal/external rotation of the upper arm and the abduction/adduction of the hand after the impact. Significant differences between the two directions were found in the end of the racket horizontal movement, where the players showed higher wrist abduction when playing in the inside out direction (cross court: 13.9 ± 17.2°; inside out: 16.9 ± 18.6°). Players presented a higher internal rotation of the shoulder in the inside out direction (cross court: -54.0 ± 11.8°vs. inside out: -48.0 ± 11.0°) and demonstrated an increased racket linear velocity in the cross court direction (cross court: 32.0±3.5m/s vs. Inside out: 30.3±3.8m/s). Horizontal flexion/abduction of the upper arm and flexion/extension of the forearm were the major contributors for the racket’s head speed.; Resumo: O objetivo do presente estudo foi comparar variáveis cinemáticas entre uma direita cruzada e descruzada no ténis e quantificar a contribuição do membro superior para a velocidade da cabeça da raquete Foram utilizados mini sensores inerciais (Xsens MVN) para capturar o movimento de seis atletas profissionais (ranking ATP). Para capturar a velocidade da raquete e da bola foi utilizada uma câmara de alta velocidade...

Análise cinemática tridimensional do salto em distância de atletas de alto nível em competição; Three-dimensional kinematic analysis of the long jump in high level in competition

Jerusa Petróvna Resende Lara
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 04/02/2011 PT
Relevância na Pesquisa
36.49%
O presente trabalho teve como objetivo fazer a análise cinemática tridimensional do salto em distância de atletas de alto nível em competição através de quatro trabalhos independentes. O primeiro trabalho teve como objetivo analisar a relação das variáveis cinemáticas do salto em distância de atletas de alto nível em competição através de uma análise de regressão linear múltipla nas fases de aproximação, impulsão e voo. Os resultados encontrados foram que a velocidade escalar do centro de massa no touchdown , a altura máxima do centro de massa na fase de voo e a distância do pé de apoio do atleta à tábua de impulsão foram as variáveis incluídas no modelo de predição da distância saltada, sendo conjuntamente responsáveis por 68% da variabilidade da distância. Para um segundo modelo, onde as velocidades escalares foram substituídas pelas componentes das velocidades do centro de massa, a velocidade horizontal do centro de massa no touchdown, a velocidade vertical do centro de massa no touchdown e o ângulo de ataque foram responsáveis por 88% da variabilidade da distância saltada. O segundo trabalho teve como objetivo analisar a replicabilidade e a reprodutibilidade das variáveis cinemáticas tridimensionais no salto em distância e testar a sensibilidade dos valores de replicabilidade e reprodutibilidade na predição da distância saltada. Para esse estudo dez observadores de ambos os sexos realizaram cinco medições cada um de um mesmo salto em distância sob as condições que definem reprodutibilidade e replicabilidade. A partir das edições dos observadores...

Kinematic Discrimination of tW and tt Productions Using Initial State Radiation

Kim, Doojin; Kong, Kyoungchul
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.25%
Production of a single top quark provides excellent opportunity for understanding top quark physics and Cabibbo-Kobayashi-Maskawa structure of the quark sector in the Standard Model. Although an associated production with a b-quark has already been observed at the Tevatron in 2009, a single top production in association with a W gauge boson has not been observed till 2014 at the LHC, where pair production of the top quark serves as the dominant background. Due to the kinematic similarity between tW and the dominant background, it is challenging to find suitable kinematic variables that offer good signal-background separation, which naturally leads to the use of multivariate methods. In this paper, we investigate kinematic structure of tW+j channel using M_T2 and invariant mass variables, and find that tW +j production could well be separated from tt production with high purity at a low cost of statistics when utilizing these kinematic correlations.; Comment: 15 pages, 11 figures, 3 tables, journal submitted version, references added

Strategies for Probing Non-Minimal Dark Sectors at Colliders: The Interplay Between Cuts and Kinematic Distributions

Dienes, Keith R.; Su, Shufang; Thomas, Brooks
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 09/07/2014
Relevância na Pesquisa
36.31%
In this paper, we examine the strategies and prospects for distinguishing between traditional dark-matter models and models with non-minimal dark sectors --- including models of Dynamical Dark Matter (DDM) --- at hadron colliders. For concreteness, we focus on events with two hadronic jets and large missing transverse energy at the Large Hadron Collider (LHC). As we discuss, simple "bump-hunting" searches are not sufficient; probing non-minimal dark sectors typically requires an analysis of the actual shapes of the distributions of relevant kinematic variables. We therefore begin by identifying those kinematic variables whose distributions are particularly suited to this task. However, as we demonstrate, this then leads to a number of additional subtleties, since cuts imposed on the data for the purpose of background reduction can at the same time have the unintended consequence of distorting these distributions in unexpected ways, thereby obscuring signals of new physics. We therefore proceed to study the correlations between several of the most popular relevant kinematic variables currently on the market, and investigate how imposing cuts on one or more of these variables can impact the distributions of others. Finally, we combine our results in order to assess the prospects for distinguishing non-minimal dark sectors in this channel at the upgraded LHC.; Comment: 16 pages...

Significance Variables

Nachman, Benjamin; Lester, Christopher G.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 27/03/2013
Relevância na Pesquisa
36.29%
Many particle physics analyses which need to discriminate some background process from a signal ignore event-by-event resolutions of kinematic variables. Adding this information, as is done for missing momentum significance, can only improve the power of existing techniques. We therefore propose the use of significance variables which combine kinematic information with event-by-event resolutions. We begin by giving some explicit examples of constructing optimal significance variables. Then, we consider three applications: new heavy gauge bosons, Higgs to $\tau\tau$, and direct stop squark pair production. We find that significance variables can provide additional discriminating power over the original kinematic variables: $\sim$ 20% improvement over $m_T$ in the case of $H\rightarrow\tau\tau$ case, and $\sim$ 30% impovement over $m_{T2}$ in the case of the direct stop search.; Comment: 21 pages, 7 figures

Assigning UPDRS Scores in the Leg Agility Task of Parkinsonians: Can It Be Done through BSN-based Kinematic Variables?

Giuberti, Matteo; Ferrari, Gianluigi; Contin, Laura; Cimolin, Veronica; Azzaro, Corrado; Albani, Giovanni; Mauro, Alessandro
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 31/10/2014
Relevância na Pesquisa
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In this paper, by characterizing the Leg Agility (LA) task, which contributes to the evaluation of the degree of severity of the Parkinson's Disease (PD), through kinematic variables (including the angular amplitude and speed of thighs' motion), we investigate the link between these variables and Unified Parkinson's Disease Rating Scale (UPDRS) scores. Our investigation relies on the use of a few body-worn wireless inertial nodes and represents a first step in the design of a portable system, amenable to be integrated in Internet of Things (IoT) scenarios, for automatic detection of the degree of severity (in terms of UPDRS score) of PD. The experimental investigation is carried out considering 24 PD patients.; Comment: 10 pages

Blood lactate concentrations and kinematic behavior of young runners in 50 and 100m sprints; Concentrações de lactato sangüíneo e o comportamento cinemático de corredores mirins em provas de 50 e 100m rasos

Dal Pupo, Juliano; Universidade Federal de Santa Catarina
Fonte: Universidade Federal de Santa Catarina. Florianópolis, SC. Brasil Publicador: Universidade Federal de Santa Catarina. Florianópolis, SC. Brasil
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; "Avaliado por Pares",; ; Avaliado por Pares; Pesquisa descritiva Formato: application/pdf; application/pdf
Publicado em 04/01/2008 POR; ENG
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36.37%
http://dx.doi.org/10.5007/1980-0037.2008v10n4p393The purpose of this study was to verify the kinematic behavior of young runners during 50 and 100m sprints and their blood lactate concentration at the end of these sprints. Kinematic analysis was performed on the speed curve and some variables analyzed at the end of these runs. Fourteen individuals took part in this study, being 7 males (12.35 ± 0.83 years) and 7 females (12.61 ± 0.70 years). The speed curve was constructed using the panning method. The remaining kinematic variables were measured using two-dimensional videography with a Peak Motus video camera operating at 180 Hz. Blood samples were taken from the runners’ earlobes in order to assay lactate concentration. The results demonstrate that at both distances top speed is reached at 40m. This, however, corresponds to 80% of the distance of the 50m sprint, but just 40% of the 100m run. The significant differences in kinematic variables observed between the two sprints were: increased duration of the support phase in the males, decreased stride frequency among the females and lower average speed at the end of 100m in comparison to 50m, in all individuals. The highest blood lactate concentrations were observed after the 100m run. It was concluded that there was greater loss of performance during 100m...