Flying, fasting, and feeding in birds during migration: a nutritional and physiological ecology perspective

Unlike exercising mammals, migratory birds fuel very high intensity exercise (e.g., flight) with fatty acids delivered from the adipose tissue to the working muscles by the circulatory system. Given the primary importance of fatty acids for fueling intense exercise, we discuss the likely limiting steps in lipid transport and oxidation for exercising birds and the ecological factors that affect the quality and quantity of fat stored in wild birds. Most stored lipids in migratory birds are comprised of three fatty acids (16:0, 18:1 and 18:2) even though migratory birds have diverse food habits. Diet selection and selective metabolism of lipids play important roles in determining the fatty acid composition of birds which, in turn, affects energetic performance during intense exercise. As such, migratory birds offer an intriguing model for studying the implications of lipid metabolism and obesity on exercise performance. We conclude with a discussion of the energetic costs of migratory flight and stopover in birds, and its implications for bird migration strategies.

The upgraded DO detector

The DO experiment enjoyed a very successful data-collection run at the Fermilab Tevatron collider between 1992 and 1996. Since then, the detector has been upgraded to take advantage of improvements to the Tevatron and to enhance its physics capabilities. We describe the new elements of the detector, including the silicon microstrip tracker, central fiber tracker, solenoidal magnet, preshower detectors, forward muon detector, and forward proton detector. The uranium/liquid -argon calorimeters and central muon detector, remaining from Run 1, are discussed briefly. We also present the associated electronics, triggering, and data acquisition systems, along with the design and implementation of software specific to DO. (c) 2006 Elsevier B.V. All rights reserved.

CMS physics technical design report, volume II: Physics performance

CMS is a general purpose experiment, designed to study the physics of pp collisions at 14 TeV at the Large Hadron Collider ( LHC). It currently involves more than 2000 physicists from more than 150 institutes and 37 countries. The LHC will provide extraordinary opportunities for particle physics based on its unprecedented collision energy and luminosity when it begins operation in 2007. The principal aim of this report is to present the strategy of CMS to explore the rich physics programme offered by the LHC. This volume demonstrates the physics capability of the CMS experiment. The prime goals of CMS are to explore physics at the TeV scale and to study the mechanism of electroweak symmetry breaking - through the discovery of the Higgs particle or otherwise. To carry out this task, CMS must be prepared to search for new particles, such as the Higgs boson or supersymmetric partners of the Standard Model particles, from the start- up of the LHC since new physics at the TeV scale may manifest itself with modest data samples of the order of a few fb(-1) or less. The analysis tools that have been developed are applied to study in great detail and with all the methodology of performing an analysis on CMS data specific benchmark processes upon which to gauge the performance of CMS. These processes cover several Higgs boson decay channels, the production and decay of new particles such as Z' and supersymmetric particles, B-s production and processes in heavy ion collisions. The simulation of these benchmark processes includes subtle effects such as possible detector miscalibration and misalignment. Besides these benchmark processes, the physics reach of CMS is studied for a large number of signatures arising in the Standard Model and also in theories beyond the Standard Model for integrated luminosities ranging from 1 fb(-1) to 30 fb(-1). The Standard Model processes include QCD, B-physics, diffraction, detailed studies of the top quark properties, and electroweak physics topics such as the W and Z(0) boson properties. The production and decay of the Higgs particle is studied for many observable decays, and the precision with which the Higgs boson properties can be derived is determined. About ten different supersymmetry benchmark points are analysed using full simulation. The CMS discovery reach is evaluated in the SUSY parameter space covering a large variety of decay signatures. Furthermore, the discovery reach for a plethora of alternative models for new physics is explored, notably extra dimensions, new vector boson high mass states, little Higgs models, technicolour and others. Methods to discriminate between models have been investigated. This report is organized as follows. Chapter 1, the Introduction, describes the context of this document. Chapters 2-6 describe examples of full analyses, with photons, electrons, muons, jets, missing E-T, B-mesons and tau's, and for quarkonia in heavy ion collisions. Chapters 7-15 describe the physics reach for Standard Model processes, Higgs discovery and searches for new physics beyond the Standard Model.

Velocidade de corrida associada ao consumo máximo de oxigênio em meninos de 10 a 15 anos

O objetivo deste estudo foi determinar a influência da idade cronológica e da maturação biológica sobre o consumo máximo de oxigênio (VO2max) e a velocidade de corrida correspondente ao VO2max em crianças e adolescentes brasileiros, do sexo masculino, com idade entre 10 e 15 anos, não praticantes de atividade física sistemática. Participaram do estudo 40 voluntários, divididos em dois grupos, segundo a idade cronológica (GC1 - n = 20; 11,4 ± 0,6 anos; 38,8 ± 8,6kg; 143,6 ± 8,2cm e GC2 - n = 20; 14,1 ± 0,6 anos; 55,9 ± 14,2kg; 163,3 ± 10,2cm) e maturação biológica (GB1 - n = 20; estágios 1, 2 e 3; e GB2 - n = 20; estágios 4 e 5). O VO2max foi mensurado em um teste progressivo e intermitente de corrida em esteira rolante, com estágios de três minutos e pausa de 20 segundos, incrementos de 1km/h a começar com 9km/h, até a exaustão voluntária. A velocidade correspondente ao VO2max (vVO2max) foi considerada como a menor velocidade em que se observou o maior valor de VO2. A máxima velocidade aeróbia (Va max) foi calculada pela fórmula proposta por di Prampero (1986). Houve diferença significante para os valores de VO2max(l/min), Va max(km/h)e vVO2max(km/h) entre os grupos GC1 e GC2 (1,84 ± 0,41 / 2,81 ± 0,61; 11,8 ± 1,2 / 12,6 ± 1,2; 12,1 ± 1,2 / 12,9 ± 1,1, respectivamente), GB1 e GB2 (1,80 ± 0,37 / 2,87 ± 0,56; 12,1 ± 1,2 / 12,9 ± 1,1; 11,8 ± 1,2 / 12,5 ± 1,1, respectivamente), mas não para os valores de VO2max em ml.kg-1.min-1 para todos os grupos (GC1 e GC2: 47,9 ± 6,8 / 50,4 ± 5,5; GB1 e GB2: 47,9 ± 6,8 / 50,3 ± 5,5, respectivamente). Com base nos resultados obtidos, pode-se concluir que o VO2max (l/min), aVa max e a vVO2max têm seus valores aumentados como um provável efeito do crescimento e desenvolvimento, podendo, ainda, expressar melhora da economia de movimento, mesmo em indivíduos não praticantes de atividade física sistemática.

Influência da forma de indução à acidose na determinação da intensidade de lactato mínimo em corredores de longa distância

O objetivo principal deste estudo foi verificar se diferentes formas de indução à acidose interferem na determinação da intensidade do lactato mínimo (LACmin) em corredores de longa distância. Desse modo, 14 corredores de provas fundas do atletismo participaram do estudo. Os atletas realizaram três protocolos: 1) teste incremental em esteira rolante, com incrementos de 1km.h-1 a cada três minutos até a exaustão, para a determinação das intensidades de limiar anaeróbio (OBLA), de limiar aeróbio (Laer), consumo máximo de oxigênio (VO2max) e intensidade de consumo máximo de oxigênio (vVO2max); 2) teste de lactato mínimo em pista de atletismo (LACminp), que consistiu de dois esforços máximos de 233m na pista de atletismo com intervalo de um minuto entre cada repetição, com oito minutos de recuperação passiva, seguido de um teste incremental semelhante ao do protocolo 1; e 3) teste de lactato mínimo em esteira rolante (LACmine), constituído de dois esforços máximos de um minuto e 45 segundos com intervalo de um minuto, na intensidade de 120% da vVO2max, seguido dos mesmos procedimentos do protocolo 2. Foram coletadas amostras de sangue do lóbulo da orelha ao final de cada estágio em todos os protocolos e no 7º minuto de recuperação passiva dos testes de LACmine e LACminp. A análise de variância (ANOVA) mostrou que ocorreram diferenças significativas entre as intensidades de LACmine (13,23 ± 1,78km.h-1) e OBLA (14,67 ± 1,44km.h-1). Dessa maneira, a partir dos resultados obtidos no presente estudo, é possível concluir que a determinação da intensidade correspondente ao lactato mínimo é dependente do protocolo utilizado para a indução à acidose. Além disso, o LACmine subestimou a intensidade correspondente ao OBLA, não podendo ser utilizado para a mensuração da capacidade aeróbia de corredores fundistas.

Aspectos fisiológicos do mountain biking competitivo

A prática do ciclismo off-road (mountain biking - MTB), cresceu muito nas últimas duas décadas, sendo incluído como esporte olímpico, nos Jogos de Atlanta em 1996, na modalidade Cross Country. Na última década, houve um aumento no número de publicações científicas que verificaram a demanda fisiológica durante competições, assim como o estudo de possíveis preditores da performance nesta modalidade. O objetivo deste estudo de revisão foi descrever alguns aspectos fisiológicos específicos do MTB Cross Country (MTB CC) competitivo (intensidade de provas, perfil fisiológico de atletas de elite, uso de suspensões e determinantes da performance em subidas). Observa-se na literatura analisada que as provas de MTB CC parecem impor uma sobrecarga fisiológica maior, quando analisada através da frequência cardíaca, do que provas de ciclismo de estrada com duração semelhante. Entretanto, quando analisada pela potência de pedalada, observa-se claramente a característica intermitente da modalidade, com variações de potência durante a prova entre zero e 500W, e potência média relativamente baixa em comparação aos valores de FC encontrados. Outro fator importante levantado neste estudo são as alterações fisiológicas decorrentes do uso de suspensões nas bicicletas de MTB CC. O uso deste equipamento reduz o estresse muscular provocado pelo terreno acidentado, embora pareça não afetar o gasto energético total, tanto em percurso plano como em subidas. Entretanto, é fato que o desempenho em circuitos acidentados é melhorado com o uso das suspensões. Com base nos estudos abordados nessa revisão, conclui-se que o MTB CC enquanto modalidade competitiva apresenta uma grande variação de intensidade (avaliada através da potência), sendo esta atribuída principalmente ao tipo de terreno (irregular e com muitas aclives e declives acentuados) em que as provas de MTB CC acontecem.

Variáveis fisiológicas e neuromusculares associadas com a performance aeróbia em corredores de endurance: efeitos da distância da prova

O objetivo deste estudo foi analisar a validade do consumo máximo de oxigênio (VO2max), velocidade associada ao VO2max (vVO2max), tempo de exaustão na vVO2max (Tlim), limiar anaeróbio (LAn), economia de corrida (EC) e força explosiva (FE) para predizer a performance aeróbia de corredores de endurance nas distâncias de 1.500m, 5.000m e 10.000m. Participaram deste estudo 11 corredores de endurance moderadamente treinados (28,36 ± 6,47 anos) que realizaram os seguintes testes: provas simuladas em uma pista de 400m em diferentes dias, nas distâncias de 10.000m, 5.000m e 1.500m; teste incremental máximo para determinar os índices VO2max, vVO2max, e LAn; um teste submáximo de carga constante para determinar a EC, seguido por um teste máximo também de carga constante a 100% da vVO2max para determinar o Tlim; e um teste de salto vertical para determinar a FE. de acordo com a análise de regressão múltipla, a vVO2max utilizada de forma isolada explicou 57% da variação de performance na prova de 1.500m. No entanto, quando o Tlim, a FE e a vVO2max foram analisados em conjunto, a explicação para a performance nessa prova foi de 88%. Nos 5.000m, o Tlim, a vVO2max e o LAn responderam por 88% da variação de performance (p < 0,05). Diferentemente, na prova de 10.000m, o LAn foi a única variável que apresentou capacidade de predição de performance. em conclusão, a predição da performance aeróbia de corredores moderadamente treinados por meio de variáveis fisiológicas e neuromusculares é dependente da distância da prova (1.500m, 5.000m e 10.000m)

Effect of exercise mode on the blood lactate removal during recovery of high-intensity exercise

The aim of this study was to determine the effect of exercise mode on the blood lactate removal during recovery of high-intensity exercise. Nine male individuals performed the following tests in order to determine the blood lactate removal: Running - 2x200 m, the subjects ran at their maximum capacity, and rested 2 min between each bout. Swimming - 2x50 m, the subjects swam at their maximum capacity, and rested 2 min between each bout. Each test was realized on different days with three recovery modes: passive (sitting down), swimming, or running. Recovery exercise intensity was corresponding to the aerobic threshold. All recovery activities lasted 30 min. The two forms of active recovery were initiated 2 min after the end of high-intensity exercise and lasted 15 min, and were followed by 13 min of seated rest. After 1,7, 12,17, and 30 min of the end of high-intensity exercise, blood samples (25 mu l) were collected in order to determine the blood lactate concentration. By linear regression, between the logarithm of lactate concentration and its respective time of recovery, the half-time of blood lactate removal (t1/2) was determined. Time of high-intensity exercise and the lactate concentration obtained in the 1(st) min of recovery were not different between running and swimming. Passive recovery (PR) following running (R-PR=25.5+/-4.3 min) showed a t1/2 significantly higher than PR after swimming (S-PR=18.6+/-4.3 min). The t1/2 of the sequences running-running (R-R=13.0 min), running-swimming (R-S=12.9+/-3.8 min), swimming-swimming (S-S=13.2+/-2.8 min), and swimming-running (S-R=12.9+/-3.8 min) were significantly lower than the t1/2 of the R-PR and S-PR. There was no difference between the t1/2 of the sequences R-R R-S, and S-S. on the other hand the sequence S-R showed a t1/2 significantly lower than the sequences S-S and R-R. It was concluded that the two forms of active recovery determine an increase in the blood lactate removal, regardless of the mode of high-intensity exercise performed previously. Active recovery performed by the muscle groups that were not previously fatigued, can improve the blood lactate removal.

Effect of the chronological age and sexual maturation on the time to exhaustion at maximal aerobic speed

The purposes of this study were: a) to verify the effect of chronological age and sexual maturation on the time to exhaustion at VO(2)max (t(lim)) and; b) to examine the reproducibility of t(lim) in boys aged 10-15 years. Forty boys, divided into 4 groups, in accordance to the chronological age (G10-12 and G13-15) and sexual maturation (P1-P3 and P4-P5 levels for pubic hair), performed the following tests: 1) incremental test for determination of VO(2)max and; 2) all-out exercise bout performed at VO(2)max to determine the t(lim). There was no difference of t(lim) (sec) between G10-12 and G13-15 (181.5 +/- 96.3 vs. 199 105.5). While the two measures of t(lim) were moderately related (r = 0.78), t(lim) from the second test (226.6 +/- 96.1 s) was higher than that of the first (191.3 +/- 79.2 s). We can conclude that the t(lim) is not influenced by chronological age and sexual maturation. Besides, t(lim) presents a lower reproducibility in children and adolescents.

Assessment of anaerobic power of swimmers: the correlation of laboratory tests on an arm ergometer with field tests in a swimming fool

The aim of this study was to verify the correlation between the Wingate arm crank test outputs (peak power, mean power, and fatigue index), obtained on a specific ergometer, and the performance in crawl stroke swim sprints of 14, 25, 50, and 400 m. The experiment was conducted with 9 healthy male volunteers (18.1 +/- 2.2 years of age; 172 +/- 0.04 cm; 67.7 +/- 5.92 kg and 15.7 +/- 4.57% body fat). on determined days, all individuals were submitted to the Wingate arm crank test and crawl freestyle sprints of 14, 25, 50, and 400 m as they were timed with a stopwatch. The peak power, the mean power, and the fatigue index, which were obtained during the Wingate arm crank test, were not significantly correlated with the maximum swim velocities during the crawl free-style tests of 14 (r = 0.40; r = 0.64; r = 0.11), 25 (r = 0.28; r = 0.39; r = -0.27), 50 (r = 0.03; r = 0.09; r = -0.31), and 400 (r = -0.52; r = -0.37; r = -0.65) m respectively. Thus, it is possible to conclude that the Wingate arm crank test is not suitable to assess the anaerobic power of swimmers under the described experimental conditions.

Effects of Strength Training on Running Economy

The objective of this study was to compare the effect of different strength training protocols added to endurance training on running economy (RE). Sixteen well-trained runners (27.4 +/- 4.4 years; 62.7 +/- 4.3 kg; 166.1 +/- 5.0 cm), were randomized into two groups: explosive strength training (EST) (n = 9) and heavy weight strength training (HWT) (n = 7) group. They performed the following tests before and after 4 weeks of training: 1) incremental treadmill test to exhaustion to determine of peak oxygen uptake and the velocity corresponding to 3.5 mM of blood lactate concentration; 2) submaximal constant-intensity test to determine RE; 3) maximal countermovernent jump test and; 4) one repetition maximal strength test in leg press. After the training period, there was an improvement in RE only in the HWT group (HWT = 47.3 +/- 6.8 vs. 44.3 +/- 4.9 ml.kg(-1) -min(-1); EST = 46.4 +/- 4.1 vs. 45.5 +/- 4.1 ml.kg(-1) .min(-1)). In conclusion, a short period of traditional strength training can improve RE in well-trained runners, but this improvement can be dependent on the strength training characteristics. When comparing to explosive training performed in the same equipment, heavy weight training seems to be more efficient for the improvement of RE.

Effects of Exercise Mode on the Oxygen Uptake Kinetic Response to Severe-Intensity Exercise in Prepubertal Children

The objective of this study was to verify the effect of the exercise mode on slow component of VO(2) (VO(2)SC) in children aged 11-12 years during severe-intensity exercise. After determination of the lactate threshold (LT) and peak VO(2) (VO(2)peak) in both cycling (CE) and running exercise (TR), fourteen active boys completed a series of "square-wave" transitions of 6-min duration at 75%Delta [75%Delta = LT + 0.75 X (VO(2)peak-LT)l to determine the VO(2) kinetics. The VO(2)SC was significantly higher in CE (180.5 +/- 155.8 ml . min(-1)) than in TR (113.0 +/- 84.2 ml . min(-1)). We can conclude that, although a VO(2)SC does indeed develop during TR in children, its magnitude is considerably lower than in CE during severe-intensity exercise.