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Effects of musical cadence in the acute physiologic adaptations to head-out aquatic exercises

Barbosa, Tiago M.; Sousa, V.; Silva, A.J.; Reis, V.M.; Marinho, D.A.; Bragada, José A.
Fonte: Instituto Politécnico de Bragança Publicador: Instituto Politécnico de Bragança
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
27.23%
The purpose of this study was to analyze the relationships between musical cadence and the physiologic adaptations to basic head-out aquatic exercises. Fifteen young and clinically healthy women performed, immersed to the breast, a cardiovascular aquatic exercise called the ‘‘rocking horse.’’ The study design included an intermittent and progressive protocol starting at a 90 b min21 rhythm and increasing every 6 minutes, by 15 b min21, up to 195 b min21 or exhaustion. The rating of perceived effort (RPE) at the maximal heart rate achieved during each bout (HRmax), the percentage of the maximal theoretical heart rate estimated (%HRmax), and the blood lactate concentration ([La-]) were evaluated. The musical cadence was also calculated at 4 mmol L21 of blood lactate (R4), the RPE at R4 (RPE@R4), the HR at R4 (HR@R4), and the %HRmax at R4 (%HRmax@R4). Strong relationships were verified between the musical cadence and the RPE (R2 = 0.85; p , 0.01), the HRmax (R2 = 0.66; p , 0.01), the %HRmax (R2 = 0.61; p , 0.01), and the [La-] (R2 = 0.54; p , 0.01). The R4 was 148.13 6 17.53 b min21, the RPE@R4 was 14.53 6 2.53, the HR@R4 was 169.33 6 12.06 b min21, and the %HRmax@R4 was 85.53 6 5.72%. The main conclusion is that increasing musical cadence created an increase in the physiologic response. Therefore...

Kinematical characterisation of a basic head-out aquatic Exercise during an incremental protocol

Oliveira, C.; Teixeira, Genoveva; Costa, M.J.; Marinho, D.A.; Silva, A.J.; Barbosa, Tiago M.
Fonte: Norwegian School of Sports Science Publicador: Norwegian School of Sports Science
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
27.23%
The aim of this study was to analyze the relationships between musical cadence and kinematical characteristics of a basic head-out aquatic exercise. Six young women with at least one year of experience conducting head-out aquatic classes were videotaped in the sagital plane with a pair of cameras providing a dual projection from both above and underwater performing 5 incremental bouts (120, 135, 150, 165 and 180 b.min-1) of the basic head-out aquatic exercise “rocking horse”. There was a decrease of the cycle period throughout the protocol. Relationships between horizontal or vertical displacements with music cadence were not significant. Increased cadence imposed increased segmental and centre of mass’ velocities. As a conclusion expert and fit subjects seem to increase segmental velocity with increasing musical cadence.

Relationships between head-out aquatic exercise kinematics and musical cadence: analysis of the side kick

Oliveira, C.; Teixeira, Genoveva; Costa, M.J.; Marinho, D.A.; Silva, A.J.; Barbosa, Tiago M.
Fonte: International Federation Sports Medicine Publicador: International Federation Sports Medicine
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
27.23%
Background: Head-out aquatic exercises became one of the most popular physical activities within the health primarily and thirdly prevention system. Music is seen as one of the most important aspects when conducting head-out aquatic exercise sessions. Research question: Is there any relationship between musical cadence and the kinematic behaviour when performing aerobic head-out aquatic exercises? It was hypothesized that an increase in music cadence will would impose a decrease of the segment range of motion. Type of study: Experimental, prospective. Methods: Six young and clinically healthy women with at least one year of experience conducting head-out aquatic classes were videotaped in the frontal plane, with a pair of cameras providing a double projection (above and below the water surface). Subjects performed an incremental protocol of five bouts (120b.min-1, 135b.min-1, 150b.min-1, 165b.min-1 and 180b.min-1) with 16 full cycles of the “side kick” exercise. Data processing and calculation of segmental (i.e. hands and feet) and anatomical landmark (i.e. centre of mass) were performed using the software Ariel Performance Analysis System and applying the DLT algorithm. Results: There was a decrease in the cycle period during the incremental protocol. The relationships between the segmental lateral and vertical displacements with the musical cadence were not significant. The segmental velocities on the lateral and vertical components showed significant increases throughout the incremental protocol. Conclusions: The data suggest that segmental velocity increases with increasing cadence...

The influence of musical cadence into aquatic jumping jacks kinematics

Costa, M.J.; Oliveira, C.; Teixeira, Genoveva; Marinho, D.A.; Silva, A.J.; Barbosa, Tiago M.
Fonte: Journal Sports Science and Medicine Publicador: Journal Sports Science and Medicine
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
27.12%
The aim of this study was to analyze the relationships between the head-out aquatic exercise “Jumping jacks” kinematics and the musical cadence in healthy and fit subjects. Five young women, with at least one year of experience conducting headout aquatic programs were videotaped in the frontal plane, with a pair of cameras providing a double projection (above and below the water surface). Subjects performed an incremental protocol of five bouts (120 b·min-1, 135 b·min-1, 150 b·min-1, 165 b·min-1 and 180 b·min-1) with 16 full cycles of the “Jumping jacks” exercise. Data processing and calculation of upper limbs’ (i.e. hands), lower limbs’ (i.e. feet) and center of mass’ 2D linear velocity and displacement were computed with the software Ariel Performance Analysis System and applying the 2DDLT algorithm. Subjects decreased the cycle period during the incremental protocol. Significant and negative relationships with the musical cadence were verified for the center of mass and upper limbs vertical displacement. On the other hand, for the lower limbs lateral velocity, a significant and positive relationship was observed. It is concluded that expert and fit subjects increase the lower limb’s velocity to maintain the range of motion...

ELECTROMYOGRAPHY AND KINEMATIC CHANGES OF GAIT CYCLE AT DIFFERENT CADENCES IN DIABETIC NEUROPATHIC INDIVIDUALS

GOMES, Aline A.; ONODERA, Andrea N.; OTUZI, Mitie E. I.; PRIPAS, Denise; MEZZARANE, Rinaldo Andre; SACCO, Isabel C. N.
Fonte: WILEY-BLACKWELL Publicador: WILEY-BLACKWELL
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
27.12%
Introduction: Changes in gait cadence caused by challenging situations in daily life might induce higher demand for strength and propulsion in diabetic neuropathic (DN) subjects. Methods: Forty-six subjects (healthy and DN) walked at two cadences (self-selected and 25% higher). Kinematic and electromyographic data were obtained from lower limbs and compared across the gait cycle. Results: DN subjects showed a delayed peak in plantarflexor activity along the whole cycle (irrespective of cadence) compared with healthy subjects. However, during the imposed cadence, DN individuals showed reduced ankle range of motion along the entire cycle compared with the self-selected condition and healthy individuals walking at both cadences (P = 0.002). Conclusions: These findings suggest that when diabetic individuals face a new challenging situation that induces a higher demand for muscle strength and propulsion, the necessary range of motion and neuromuscular control around distal joints are insufficient. Muscle Nerve 44: 258-268, 2011; FAPESP[2007/01799-1]; FAPESP[2004/09585-2]; Canadian Bureau for International Education

Avaliação da fadiga no ciclismo por meio da análise dos momentos articulares resultantes; Fatigue evaluation by means of the analisys of resultant joint moments

Bini, Rodrigo Rico
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
27.12%
O processo de instalação da fadiga implica na mudança do padrão coordenativo durante a pedalada. Desta forma a análise da contribuição de cada articulação do membro inferior para o somatório absoluto dos momentos articulares se faz necessária para o melhor entendimento dos mecanismos relacionados aos efeitos do processo de instalação da fadiga sobre o padrão coordenativo no ciclismo. O objetivo deste estudo foi comparar a contribuição das articulações do quadril, joelho e tornozelo para o somatório absoluto dos momentos articulares resultantes, assim como a força resultante e a cinemática destas articulações, ao longo do tempo, nos modelos experimentais de carga constante e de carga incremental até a exaustão. Foram avaliados onze ciclistas de estrada da categoria elite, que participam de competições regionais (Texas) e nacionais (Estados Unidos) do sexo masculino (idade 31 ± 7 anos; consumo máximo de oxigênio 62,84 ± 4,86 ml.kg-1.min-1; potência máxima 407 ± 37 W). Onze ciclistas foram avaliados no primeiro dia de avaliação, este constituindo um teste de ciclismo máximo com incrementos de carga a cada dois minutos (75, 90 e 100% da PO máxima estimada, respectivamente). No segundo dia de avaliação...

Efeito da cadência de pedalada sobre as respostas metabólica e cardiovascular durante o exercício incremental e de carga constante em indivíduos ativos

Denadai, Benedito Sérgio; de Araújo Ruas, Vinícius Daniel; Figueira, Tiago Rezende
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica
ENG; POR
Relevância na Pesquisa
27.23%
The main purpose of this study was to analyze the effect of the pedaling cadence (500 × 100 rpm) on the heart rate (HR) and the blood lactate response during incremental and constant workload exercises in active individuals. Nine active male individuals (20.9 ± 2.9 years old; 73.9 ± 6.5 kg; 1.79 ± 0.9 m) were submitted to two incremental tests, and to 6-8 constant workload tests to determine the intensity corresponding to the maximal steady state lactate (MLSSintens) in both cadences. The maximal power (Pmax) attained during the incremental test, and the MLSSintens were significantly lower at 100 rpm (240.9 ± 12.6 W; 148.1 ± 154.W) compared to 50 rpm (263.9 ± 18.6 W; 186.1 ± 21.2 W), respectively. The HRmax did not change between cadences (50 rpm = 191.1 ± 8.8 bpm; 100 rpm = 192.6 ± 9.9 bpm). Regardless the cadence, the HRmax percentage (70, 80, 90, and 100%) determined the same lactate concentrations during the incremental test. However, when the intensity was expressed in Pmax percentage or in absolute power, the lactate and the HR values were always higher at highest cadences. The HR corresponding to MLSSintens was similar between cadences (50 rpm = 162.5 ± 9.1 bpm; 100 rpm = 160.4 ± 9.2 bpm). Based on these results...

Caracterização e Comparação Cinemática de Movimentos Básicos de Hidroginástica a Diferentes Ritmos de Execução: Análise do “Balanço lateral”

Teixeira, Genoveva Manuela Lobo Marques Coelho
Fonte: Universidade de Trás-os-Montes e Alto Douro Publicador: Universidade de Trás-os-Montes e Alto Douro
Tipo: Dissertação de Mestrado
POR
Relevância na Pesquisa
27.23%
Dissertação de Mestrado em Ciências do Desporto - Actividades de Academia; A Hidroginástica é uma actividade física que, reúne características que estimulam o desenvolvimento das principais componentes da aptidão física [100]. Para Rocha [90], esta é uma actividade que por ser realizada dentro de água, pode ser praticada por indivíduos de diversas faixas etárias, pois oferece uma reduzida carga mecânica sobre o aparelho locomotor, num ambiente supostamente descontraído e agradável do ponto de vista psicológico. O objectivo geral do presente estudo consistiu em analisar a associação entre a cadência e o padrão cinemático, um movimento básico de Hidroginástica “balanço lateral” a diferentes Cadências. A amostra estudada foi constituída por 6 instrutoras de Hidroginástica, do sexo feminino, com pelo menos um ano de experiência na leccionação deste tipo de programas, sem qualquer patologia músculo-esquelética nos últimos seis meses e não grávidas. A metodologia por nós utilizada, consistiu num registo em vídeo no plano frontal, do exercício básico de Hidroginástica “Balanço Lateral”, recorrendo a um par de câmaras, proporcionando assim uma dupla projecção do desempenho acima e abaixo do nível da água...

The relationship between cadence, pedalling technique and gross efficiency in cycling

Leirdal, Stig; Ettema, Gertjan
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.3%
Technique and energy saving are two variables often considered as important for performance in cycling and related to each other. Theoretically, excellent pedalling technique should give high gross efficiency (GE). The purpose of the present study was to examine the relationship between pedalling technique and GE. 10 well-trained cyclists were measured for GE, force effectiveness (FE) and dead centre size (DC) at a work rate corresponding to ~75% of VO2max during level and inclined cycling, seat adjusted forward and backward, at three different cadences around their own freely chosen cadence (FCC) on an ergometer. Within subjects, FE, DC and GE decreased as cadence increased (p < 0.001). A strong relationship between FE and GE was found, which was to great extent explained by FCC. The relationship between cadence and both FE and GE, within and between subjects, was very similar, irrespective of FCC. There was no difference between level and inclined cycling position. The seat adjustments did not affect FE, DC and GE or the relationship between them. Energy expenditure is strongly coupled to cadence, but force effectiveness, as a measure for pedalling technique, is not likely the cause of this relationship. FE, DC and GE are not affected by body orientation or seat adjustments...

The Power of Auditory-Motor Synchronization in Sports: Enhancing Running Performance by Coupling Cadence with the Right Beats

Bood, Robert Jan; Nijssen, Marijn; van der Kamp, John; Roerdink, Melvyn
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 07/08/2013 EN
Relevância na Pesquisa
27.3%
Acoustic stimuli, like music and metronomes, are often used in sports. Adjusting movement tempo to acoustic stimuli (i.e., auditory-motor synchronization) may be beneficial for sports performance. However, music also possesses motivational qualities that may further enhance performance. Our objective was to examine the relative effects of auditory-motor synchronization and the motivational impact of acoustic stimuli on running performance. To this end, 19 participants ran to exhaustion on a treadmill in 1) a control condition without acoustic stimuli, 2) a metronome condition with a sequence of beeps matching participants’ cadence (synchronization), and 3) a music condition with synchronous motivational music matched to participants’ cadence (synchronization+motivation). Conditions were counterbalanced and measurements were taken on separate days. As expected, time to exhaustion was significantly longer with acoustic stimuli than without. Unexpectedly, however, time to exhaustion did not differ between metronome and motivational music conditions, despite differences in motivational quality. Motivational music slightly reduced perceived exertion of sub-maximal running intensity and heart rates of (near-)maximal running intensity. The beat of the stimuli –which was most salient during the metronome condition– helped runners to maintain a consistent pace by coupling cadence to the prescribed tempo. Thus...

The Influence of Musical Cadence into Aquatic Jumping Jacks Kinematics

Costa, Mário J.; Oliveira, Cristiana; Teixeira, Genoveva; Marinho, Daniel A; Silva, António J.; Barbosa, Tiago M
Fonte: Asist Group Publicador: Asist Group
Tipo: Artigo de Revista Científica
Publicado em 01/12/2011 EN
Relevância na Pesquisa
27.12%
The aim of this study was to analyze the relationships between the head-out aquatic exercise “Jumping jacks” kinematics and the musical cadence in healthy and fit subjects. Five young women, with at least one year of experience conducting head- out aquatic programs were videotaped in the frontal plane, with a pair of cameras providing a double projection (above and below the water surface). Subjects performed an incremental protocol of five bouts (120 b·min-1, 135 b·min-1, 150 b·min-1, 165 b·min-1 and 180 b·min-1) with 16 full cycles of the “Jumping jacks” exercise. Data processing and calculation of upper limbs’ (i.e. hands), lower limbs’ (i.e. feet) and center of mass’ 2D linear velocity and displacement were computed with the software Ariel Performance Analysis System and applying the 2D-DLT algorithm. Subjects decreased the cycle period during the incremental protocol. Significant and negative relationships with the musical cadence were verified for the center of mass and upper limbs vertical displacement. On the other hand, for the lower limbs lateral velocity, a significant and positive relationship was observed. It is concluded that expert and fit subjects increase the lower limb’s velocity to maintain the range of motion...

Effect of Ankle-foot Orthosis on Gait Velocity and Cadence of Stroke Patients: A Systematic Review

Ferreira, Luiz Alfredo Braun; Neto, Hugo Pasini; Grecco, Luanda André College; Christovão, Thaluanna Calil Lourenço; Duarte, Natália AlmeidaCarvalho; Lazzari, Roberta Delasta; Galli, Manuela; Oliveira, Claudia Santos
Fonte: The Society of Physical Therapy Science Publicador: The Society of Physical Therapy Science
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.12%
[Purpose] The aim of the present study was to analyze the effect of an ankle-foot orthosis on gait variables (velocity and cadence) of stroke patients. To do this, a systematic review was conducted of four databases. [Subjects and Methods] The papers identified were evaluated based on the following inclusion criteria: 1) design: controlled, clinical trial; 2) population: stroke patients; 3) intervention: analysis of spatiotemporal variables of gait with an ankle-foot orthosis; 4) control group with different intervention or no intervention; and 5) outcome: improvement in gait velocity or cadence. [Results] Thirteen controlled trials addressing the effect of an ankle-foot orthosis on gait variables of stroke patients were found. They exhibited methodological quality of 3 or more points on the PEDro scale. [Conclusion] While the findings suggest the benefits of an AFO regarding gait velocity, the impact of this type of orthosis on cadence remains inconclusive. Thus, there is a need for further well-designed randomized, controlled, clinical trials to establish better scientific evidence for the effects of AFO usage on gait variables of stroke patients.

The Effect of Cycling Cadence on Subsequent 10km Running Performance in Well-Trained Triathletes

Tew, Garry
Fonte: Asist Group Publicador: Asist Group
Tipo: Artigo de Revista Científica
Publicado em 01/09/2005 EN
Relevância na Pesquisa
27.46%
The aim of this study was to examine the effects of different pedalling cadences on the performance of a subsequent 10km treadmill run. Eight male triathletes (age 38.9 ± 15.4 years, body mass 72.2 ± 5.2 kg, and stature 176 ± 6 cm; mean ± SD) completed a maximal cycling test, one isolated run (10km), and then three randomly ordered cycle-run sessions (65 minutes cycling + 10km run). During the cycling bout of the cycle-run sessions, subjects cycled at an intensity corresponding to 70% Pmax while maintaining one of three cadences, corresponding to preferred cadence (PC), PC+15% (fast cadence) and PC-15% (slow cadence). Slow, preferred and fast cadences were 71.8 ± 3.0, 84.5 ± 3.6, and 97.3 ± 4.3 rpm, respectively (mean ± SD). Physiological variables measured during the cycle-run and isolated run sessions were VO2, VE, RER, HR, RPE, and blood lactate. Biomechanical variables measured during the cycle-run and isolated run sessions were running velocity, stride length, stride frequency, and hip and knee angles at foot-strike and toe-off. Running performance times were also recorded. A significant effect of prior cycling exercise was found on 10km running time (p = 0.001) without any cadence effect (p = 0.801, ω2 = 0.006) (49:58 ± 8:20...

Effects Of Cadence on Aerobic Capacity Following a Prolonged, Varied Intensity Cycling Trial

Stebbins, Charles L.; Moore, Jesse L.; Casazza, Gretchen A.
Fonte: Asist Group Publicador: Asist Group
Tipo: Artigo de Revista Científica
Publicado em 20/01/2014 EN
Relevância na Pesquisa
27.12%
We determined if high cadences, during a prolonged cycling protocol with varying intensities (similar to race situations) decrease performance compared to cycling at a lower, more energetically optimal, cadence. Eight healthy, competitive male road cyclists (35 ± 2 yr) cycled for 180 min at either 80 or 100 rpm (randomized) with varying intensities of power outputs corresponding to 50, 65 and 80% of VO2max. At the end of this cycling period, participants completed a ramped exercise test to exhaustion at their preferred cadence (90 ± 7 rpm). There were no cadence differences in blood glucose, respiratory exchange ratio or rate of perceived exertion. Heart Rate, VO2 and blood lactate were higher at 100 rpm vs. 80 rpm. The total energy cost while cycling during the 65% and 80% VO2max intervals at 100 rpm (15.2 ± 2.7 and 19.1 ± 2.5 kcal∙min-1, respectively) were higher than at 80 rpm (14.3 ± 2.7 and 18.3± 2.2 kcal∙min-1, respectively) (p < 0.05). Gross efficiency was higher at 80 rpm vs. 100 rpm during both the 65% (22.8 ± 1.0 vs. 21.3 ± 4.5%) and the 80% (23.1 vs. 22.1 ± 0.9%) exercise intensities (P< 0.05). Maximal power during the performance test (362 ± 38 watts) was greater at 80 rpm than 100 rpm (327 ± 27 watts) (p < 0.05). Findings suggest that in conditions simulating those seen during prolonged competitive cycling...

Effects of different frequencies of rhythmic auditory cueing on the stride length, cadence, and gait speed in healthy young females

Yu, Lili; Zhang, Qi; Hu, Chunying; Huang, Qiuchen; Ye, Miao; Li, Desheng
Fonte: The Society of Physical Therapy Science Publicador: The Society of Physical Therapy Science
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.36%
[Purpose] The aim of this study was to explore the effects of different frequencies of rhythmic auditory cueing (RAC) on stride length, cadence, and gait speed in healthy young females. The findings of this study might be used as clinical guidance of physical therapy for choosing the suitable frequency of RAC. [Subjects] Thirteen healthy young females were recruited in this study. [Methods] Ten meters walking tests were measured in all subjects under 4 conditions with each repeated 3 times and a 3-min seated rest period between repetitions. Subjects first walked as usual and then were asked to listen carefully to the rhythm of a metronome and walk with 3 kinds of RAC (90%, 100%, and 110% of the mean cadence). The three frequencies (90%, 100%, and 110%) of RAC were randomly assigned. Gait speed, stride length, and cadence were calculated, and a statistical analysis was performed using the SPSS (version 17.0) computer package. [Results] The gait speed and cadence of 90% RAC walking showed significant decreases compared with normal walking and 100% and 110% RAC walking. The stride length, cadence, and gait speed of 110% RAC walking showed significant increases compared with normal walking and 90% and 100% RAC walking. [Conclusion] Our results showed that 110% RAC was the best of the 3 cueing frequencies for improvement of stride length...

Ability to modulate walking cadence remains intact in Parkinson's disease.

Morris, M E; Iansek, R; Matyas, T A; Summers, J J
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /12/1994 EN
Relevância na Pesquisa
27.12%
Gait hypokinesia (slowness) is a characteristic feature of Parkinson's disease. It is not clear, however, whether the slowness is due to a problem in regulation of the timing of consecutive steps or the control of stride size. Examination of cadence control for slow to medium walking speeds has shown an increase in step frequency that was a compensation for reduced stride length. In this investigation the ability of Parkinsonian patients to modulate their cadence (steps per minute) at the fast walking speeds exhibited by age and height matched controls was examined. The findings indicated that cadence control remains unaffected throughout its entire range in Parkinson's disease and that gait hypokinesia is directly attributable to an inability to internally generate sufficiently large steps.

An examination of some characteristics of Kepler Short and Long Cadence Data

Murphy, Simon J.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 30/01/2012
Relevância na Pesquisa
27.36%
A close comparison of Kepler short- and long-cadence data released prior to 2011 Nov 1 has shown some subtle differences that make the short-cadence data superior to their long-cadence counterparts. The inevitable results of a faster sampling rate are present: the short-cadence data provide greater time resolution for short-lived events like flares, and have a much higher Nyquist frequency than the long-cadence data; however, they also contain fewer high-amplitude peaks at low frequency and allow a more precise determination of pulsation frequencies, amplitudes and phases. The latter observation indicates that Kepler data are not normally distributed. Moreover, a close inspection of the Pre-search Data Conditioned (PDC) long-cadence data show residuals that have increased noise on time-scales important to asteroseismology, but unimportant to planet searches.; Comment: Accepted for publication in MNRAS. 7 pages, 5 figures

Tile or Stare? Cadence and Sky Monitoring Observing Strategies that Maximize the Number of Discovered Transients

Nemiroff, Robert J.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 29/01/2003
Relevância na Pesquisa
27.23%
To maximize the number of transients discovered on the sky, should sky-monitoring projects stare at one location or continually jump from location to location, tiling the sky? If tiling is preferred, what cadence maximizes the discovery rate? As sky monitoring is a growing part of astronomical observing, utilized to find such phenomena as supernovae, microlensing, and planet transits, well thought out answers to these questions are increasingly important. Answers are sky, source, and telescope dependent and should include information about the source luminosity distribution near the observation limit, the duration of variability, the nature of the dominant noise, and the magnitude of down and slew times. Usually, a critical slope of the effective cumulative transient apparent luminosity distribution (Log N - Log S) at the limiting magnitude will define when "tile" or "stare" is superior. For shallower slopes, when "tile" is superior, optimal cadences and pointing algorithms are discussed. For transients discovered on a single exposure or time-contiguous series of exposures, when down and slew times are small and the character of the noise is unchanged, the most productive cadence for isotropic power-law luminosity distributions is the duration of the transient -- faster cadences waste time re-discovering known transients...

Implicações da cadência de pedalada sobre a potência mecânica e o período de contração muscular no ciclismo; Pedaling cadence effects on mechanical power and muscle contraction timing during cycling

JACQUES, Tiago Canal; LANFERDINI, Fábio Juner; BINI, Rodrigo Rico; VAZ, Marco Aurélio
Fonte: Universidade de São Paulo. Escola de Educação Física e Esporte Publicador: Universidade de São Paulo. Escola de Educação Física e Esporte
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 01/09/2014 POR
Relevância na Pesquisa
27.23%
The mechanical energy required to propel the crank may depend on eccentric and concentric muscle actions. However, it is uncertain whether pedaling cadence would elicit changes in concentric and eccentric contributions. Therefore, the purpose of the present study was to investigate the effects of alterations in pedaling cadence on the eccentric and concentric muscle actions. Joint power production and absorption were calculated to assess potential effects from variations in pedaling cadence on joint kinetics. Twenty-one cyclists participated in this study (VO2pico: 64.1 ± 5.0 ml/kg/min; training volume: 368.2 ± 69.5 km/week). In their first session, maximal power output (POMAX) and power output related to the second ventilation threshold (POVT2) were determined during an incremental maximal cycling test to exhaustion. In their second session, cyclists performed two 2-min trials with workload from their POVT2 at two different cadences (70 and 90 rpm). Muscle activation of six muscles, pedal forces and lower limb joint kinematics were evaluated. Longer eccentric contraction at 70 rpm for vastus medialis (8%; p < 0.01) and biceps femoris (20%; p = 0.04) were observed compared to 90 rpm. Longer concentric contraction for vastus medialis muscle (10%; p = 0.04) at 90 rpm was observed compared to 70 rpm. There were no differences in joint power production and absorption among pedaling cadences. No alterations in joint power could indicate maintenance of movement when pedaling cadence is changed. Eccentric contractions from knee muscles could be related to joint control...

Effect of pedal cadence on mechanical power output and physiological variables; Efeitos da cadência de pedalada sobre a potência mecânica e variáveis fisiológicas

Cabral Dias, Marcelo Ricardo; Universidade Castelo Branco, RJ.; Calil e Silva, André; Universidade Castelo Branco, RJ.; Marques Novo Júnior, José; Universidade Federal de Juiz de Fora, MG; Batista, Luiz Alberto; Universidade Castelo Branco, RJ.; Perrou
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 Formato: application/pdf; application/pdf
Publicado em 05/09/2007 POR; ENG
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27.12%
The objective of this study was to compare the responses of the variables maximal power output (POmax), heart rate (HR), rating of perceived exertion (RPE), systolic blood pressure (SBP), diastolic blood pressure (DBP) and double product (DP) in the maximum reached load and during 60 and 90 rev.min-1 tests. The study sample consisted of 14 men (26.5 ± 3.5 years, 78.5 ± 7.8 kg and 178.1 ± 7.0 cm) engaged in indoor cycling classes, who undertook two tests of maximum effort using Balke’s incremental protocol. The fi rst test (test60) consisted of a pedal cadence of 60 rev.min-1 throughout the test, until voluntary exhaustion or the appearance of signs or symptom limits. The second test (test90) was at a pedal cadence of 90 rev.min-1. There were no signifi cant difference between the cadences tested in terms of HRmax (test60: 189.7±12.0 beats.min-1; test90: 190.9±10.7 beats.min-1), RPEmax (test60: 20.0±0.3; test90: 20.0±1.0) or DBPmean (test60: 76.7±4.9 mmHg; test90: 79.1 ± 5.3 mmHg). On the other hand, the values of POmax (test60: 344.6±70.1 W; test90: 285.7±61.8 W), SBPmax (test60: 186.1±14.7 mmHg; test90: 202.1±21.5 mmHg) and DPmax (test60: 35402.9±4431.7; test90: 38655.0±5270.5) were different. In relation to the behavior of the variables during the tests...