Vibration training elicits a mixed aerobic and resistance-type exercise in sedentary subjects.

Objective. Vibration training (VT) is a new exercise method, with good acceptance among sedentary subjects, due to its passive principle: the machine moves the subject, not the opposite. We hypothesize that untrained subjects can benefit from a greater cardiovascular and metabolic stimulation than trained athletes, resembling classical aerobic-type activity, in addition of eliciting strength gains shown in diverse studies. Methods. 3 group of male subjects, inactive (SED), endurance trained athletes (END) and strength trained athletes (STR) underwent fitness (VO2max) and lower-body strength tests (isokinetic). Subjects were submitted to a session of oscillating VT, composed of 3 exercises (isometric half-squat, dynamic squat, dynamic squat with added load), each of 3 minutes duration, and repeated at 3 frequencies. VO2, heart rate and Borg scale were monitored. Results. 27 healthy subjects (10 SED, 9 END and 8 STR), mean age 24.5 (SED), 25.0 (STR) and 29.8 (END) were included. VO2max was significantly different as expected (47.9 vs. 52.9 vs. 63.9 ml/kg/min, resp. for SED, STR and END). Isokinetic dominant leg extensors strength was higher in STR (3.32 Nm/kg vs. 2.60 and 2.74 in SED and END). During VT, peak oxygen consumption (% of VO2max) attained was 59.3 in SED, 50.8 in STR and 48.0 in END (P<0.001 between SED and other subjects). Peak heart rate (% of heart rate max) was 82.7 in SED, 80.4 in STR and 72.4 in END. In SED, dynamic exercises without extra load elicited 51.0% of VO2max and 72.1% of heart rate max, and perceived effort reached 15.1/20. Conclusions. VT is an unconventional type of exercise, which has been shown to enhance strength, bone density, balance and flexibility. Users are attracted by the relative passivity. In SED, we show that VT elicits sufficient cardiovascular response to benefit overall fitness in addition to the known strength effects. VT's higher acceptance as an exercise in sedentary people, compared to jogging or cycling for example, can lead to better adherence to physical activity. Although long-term effects of VT on health are not avalaible, we believe this type of combination of aerobic and resistance-type exercise can be beneficial on multiple health parameters, especially cardiovascular health.

Characterization of the hcnABC gene cluster encoding hydrogen cyanide synthase and anaerobic regulation by ANR in the strictly aerobic biocontrol agent Pseudomonas fluorescens CHA0.

The secondary metabolite hydrogen cyanide (HCN) is produced by Pseudomonas fluorescens from glycine, essentially under microaerophilic conditions. The genetic basis of HCN synthesis in P. fluorescens CHA0 was investigated. The contiguous structural genes hcnABC encoding HCN synthase were expressed from the T7 promoter in Escherichia coli, resulting in HCN production in this bacterium. Analysis of the nucleotide sequence of the hcnABC genes showed that each HCN synthase subunit was similar to known enzymes involved in hydrogen transfer, i.e., to formate dehydrogenase (for HcnA) or amino acid oxidases (for HcnB and HcnC). These similarities and the presence of flavin adenine dinucleotide- or NAD(P)-binding motifs in HcnB and HcnC suggest that HCN synthase may act as a dehydrogenase in the reaction leading from glycine to HCN and CO2. The hcnA promoter was mapped by primer extension; the -40 sequence (TTGGC ... ATCAA) resembled the consensus FNR (fumarate and nitrate reductase regulator) binding sequence (TTGAT ... ATCAA). The gene encoding the FNR-like protein ANR (anaerobic regulator) was cloned from P. fluorescens CHA0 and sequenced. ANR of strain CHA0 was most similar to ANR of P. aeruginosa and CydR of Azotobacter vinelandii. An anr mutant of P. fluorescens (CHA21) produced little HCN and was unable to express an hcnA-lacZ translational fusion, whereas in wild-type strain CHA0, microaerophilic conditions strongly favored the expression of the hcnA-lacZ fusion. Mutant CHA21 as well as an hcn deletion mutant were impaired in their capacity to suppress black root rot of tobacco, a disease caused by Thielaviopsis basicola, under gnotobiotic conditions. This effect was most pronounced in water-saturated artificial soil, where the anr mutant had lost about 30% of disease suppression ability, compared with wild-type strain CHA0. These results show that the anaerobic regulator ANR is required for cyanide synthesis in the strictly aerobic strain CHA0 and suggest that ANR-mediated cyanogenesis contributes to the suppression of black root rot.

Physical activity and enhanced fitness to improve cognitive function in older people without known cognitive impairment

Physical activity is beneficial for healthy ageing. It may also help maintain good cognitive function in older age. Aerobic activity improves cardiovascular fitness, but it is not known whether this sort of fitness is necessary for improved cognitive function.��Eleven studies of aerobic physical activity programmes for healthy people over the age of 55 years have been included in this review. Eight of these 11 studies reported that aerobic exercise interventions resulted in increased fitness of the trained group and an improvement in at least one aspect of cognitive function. The largest effects were on cognitive speed, auditory and visual attention. However, the cognitive functions which improved were not the same in each study and the majority of comparisons yielded no significant results.��The data are insufficient to show that the improvements in cognitive function which can be attributed to physical exercise are due to improvements in cardiovascular fitness.

Gender differences in whole-body fat oxidation kinetics during exercise.

Discrepancies appear in studies comparing fat oxidation between men and women. Therefore, this study aimed to quantitatively describe and compare whole-body fat oxidation kinetics between genders during exercise, using a sinusoidal (SIN) model. Twelve men and 11 women matched for age, body mass index, and aerobic fitness (maximal oxygen uptake and maximal power output per kilogram of fat-free mass (FFM)) performed submaximal incremental tests (Incr) with 5-min stages and a 7.5% maximal power output increment on a cycle ergometer. Fat oxidation rates were determined using indirect calorimetry, and plotted as a function of exercise intensity. The SIN model, which includes 3 independent variables (dilatation, symmetry, translation) that account for the main quantitative characteristics of kinetics, was used to mathematically describe fat oxidation kinetics and to determine the intensity (Fatmax) eliciting the maximal fat oxidation (MFO). During Incr, women exhibited greater fat oxidation rates from 35% to 85% maximal oxygen uptake, MFO (6.6 ± 0.9 vs. 4.5 ± 0.3 mg·kg FFM-1·min-1), and Fatmax (58.1% ± 1.9% vs. 50.0% ± 2.7% maximal oxygen uptake) than men (p < 0.05). While men and women showed similar global shapes of fat oxidation kinetics in terms of dilatation and symmetry (p > 0.05), the fat oxidation curve tended to be shifted toward higher exercise intensities in women (rightward translation, p = 0.08). These results support the idea that women have a greater reliance on fat oxidation than men during submaximal exercise, but also indicate that this greater fat oxidation is shifted toward higher exercise intensities in women than in men.

Three points for speed

This poster focuses on the effects of speed. The poster message is 'Three points for speed' and then lists three of the effects: 1. Extreme tiredness 2. Disturbed sleep 3. Paranoia. It also provides contact details for the National Drugs Helpline. Tel: 0800 776600.

Taking speed can really bring you down

This poster informs about the effects of taking speed stating: 'The more speed you take, the more exhausted you are when it wears off and the more likely you are to keep taking more. And that's called addiction'. It also provides contact details for the National Drugs Helpline. Tel: 0800 776600.

Effect of acute and chronic exercise on fat oxidation and hormonal and plasma metabolite kinetics in obese and severely obese men

Acute exercise increases energy expenditure (EE) during exercise and post-exercise recovery [excess post-exercise oxygen consumption (EPOC)] and therefore may be recommended as part of the multidisciplinary management of obesity. Moreover, chronic exercise (training) effectively promotes an increase in insulin sensitivity, which seems to be associated with increased fat oxidation rates (FORs). The main purpose of this thesis is to investigate 1) FORs and extra-muscular factors (hormones and plasma metabolites) that regulate fat metabolism during acute and chronic exercise; and 2) EPOC during acute post-exercise recovery in obese and severely obese men (class II and III). In the first study, we showed that obese and severely obese men present a lower exercise intensity (Fatmax) eliciting maximal fat oxidation and a lower reliance on fat oxidation at high, but not at low and moderate, exercise intensities compared to lean men. This was most likely related to an impaired muscular capacity to oxidize non-esterified fatty acids (NEFA) rather than decreased plasma NEFA availability or a change in the hormonal milieu during exercise. In the second study, we developed an accurate maximal incremental test to correctly and simultaneously evaluate aerobic fitness and fat oxidation kinetics during exercise in this population. This test may be used for the prescription of an appropriate exercise training intensity. In the third study, we demonstrated that only 2 wk of exercise training [continuous training at Fatmax and adapted high-intensity interval training (HIIT)], matched with respect to mechanical work, may be effective to improve aerobic fitness, FORs during exercise and insulin sensitivity, which suggest that FORs might be rapidly improved and that adapted HIIT is feasible in this population. The increased FORs concomitant with the lack of changes in lipolysis during exercise suggest an improvement in the mismatching between NEFA availability and oxidation, highlighting the importance of muscular (oxidative capacity) rather than extra-muscular (hormones and plasma metabolites) factors in the regulation of fat metabolism after a training program. In the fourth study, we observed a positive correlation between EE during exercise and EPOC, suggesting that a chronic increase in the volume or intensity of exercise may increase EE during exercise and during recovery. This may have an impact in weight management in obesity. In conclusion, these findings might have practical implications for exercise training prescriptions in order to improve the therapeutic approaches in obesity and severe obesity. -- L'exercice aigu augmente la dépense énergétique (DE) pendant l'exercice et la récupération post-exercice [excès de consommation d'oxygène post-exercise (EPOC)] et peut être utilisé dans la gestion multidisciplinaire de l'obésité. Quant à l'exercice chronique (entraînement), il est efficace pour augmenter la sensibilité à l'insuline, ce qui semble être associé à une amélioration du débit d'oxydation lipidique (DOL). Le but de cette thèse est d'étudier 1) le DOL et les facteurs extra-musculaires (hormones et métabolites plasmatiques) qui régulent le métabolisme lipidique pendant l'exercice aigu et chronique et 2) l'EPOC lors de la récupération aiguë post-exercice chez des hommes obèses et sévèrement obèses (classe II et III). Dans la première étude nous avons montré que les hommes obèses et sévèrement obèses présentent une plus basse intensité d'exercice (Fatmax) correspondant au débit d'oxydation lipidique maximale et un plus bas DOL à hautes, mais pas à faibles et modérées, intensités d'exercice comparé aux sujets normo-poids, ce qui est probablement lié à une incapacité musculaire à oxyder les acides gras non-estérifiés (AGNE) plutôt qu'à une diminution de leur disponibilité ou à un changement du milieu hormonal pendant l'exercice. Dans la deuxième étude nous avons développé un test maximal incrémental pour évaluer simultanément l'aptitude physique aérobie et la cinétique d'oxydation des lipides pendant l'exercice chez cette population. Dans la troisième étude nous avons montré que seulement deux semaines d'entraînement (continu à Fatmax et intermittent à haute intensité), appariés par la charge de travail, sont efficaces pour améliorer l'aptitude physique aérobie, le DOL pendant l'exercice et la sensibilité à l'insuline, ce qui suggère que le DOL peut être rapidement amélioré chez cette population. Ceci, en absence de changements de la lipolyse pendant l'exercice, suggère une amélioration de la balance entre la disponibilité et l'oxydation des AGNE, ce qui souligne l'importance des facteurs musculaires (capacité oxydative) plutôt que extra-musculaires (hormones et métabolites plasmatiques) dans la régulation du métabolisme lipidique après un entraînement. Dans la quatrième étude nous avons observé une corrélation positive entre la DE pendant l'exercice et l'EPOC, ce qui suggère qu'une augmentation chronique du volume ou de l'intensité de l'exercice pourrait augmenter la DE lors de l'exercice et lors de la récupération post-exercice. Ceci pourrait avoir un impact sur la gestion du poids chez cette population. En conclusion, ces résultats pourraient avoir des implications pratiques lors de la prescription des entraînements dans le but d'améliorer les approches thérapeutiques de l'obésité et de l'obésité sévère.

Hyperthermia and maximal oxygen uptake in men and women.

To compare the effect of hyperthermia on maximal oxygen uptake (VO2max) in men and women, VO2max was measured in 11 male and 11 female runners under seven conditions involving various ambient temperatures (Ta at 50% RH) and preheating designed to manipulate the esophageal (Tes) and mean skin (Tsk) temperatures at VO2max. The conditions were: 25 degrees C, no preheating (control); 25, 35, 40, and 45 degrees C, with exercise-induced preheating by a 20-min walk at approximately 33% of control VO2max; 45 degrees C, no preheating; and 45 degrees C, with passive preheating during which Tes and Tsk were increased to the same degree as at the end of the 20-min walk at 45 degrees C. Compared to VO2max (l x min(-1)) in the control condition (4.52+/-0.46 in men, 3.01+/-0.45 in women), VO2max in men and women was reduced with exercise-induced or passive preheating and increased Ta, approximately 4% at 35 degrees C, approximately 9% at 40 degrees C and approximately 18% at 45 degrees C. Percentage reductions (7-36%) in physical performance (treadmill test time to exhaustion) were strongly related to reductions in VO2max (r=0.82-0.84). The effects of hyperthermia on VO2max and physical performance in men and women were almost identical. We conclude that men and women do not differ in their thermal responses to maximal exercise, or in the relationship of hyperthermia to reductions in VO2max and physical performance at high temperature. Data are reported as mean (SD) unless otherwise stated.

Right-left digit ratio (2D:4D) and maximal oxygen uptake.

A low digit ratio (2D:4D) and low 2D:4D in the right compared with the left hand (right-left 2D:4D) are thought to be determined by high in utero concentrations of testosterone, and are related to "masculine" traits such as aggression and performance in sports like running and rugby. Low right-left 2D:4D is also related to sensitivity to testosterone as measured by the number of cytosine-adenine-guanine triplet repeats in exon 1 of the androgen receptor gene. Here we show that low right-left 2D:4D is associated with high maximal oxygen uptake (VO2(max)), high velocity at VO2(max), and high maximum lactate concentration in a sample of teenage boys. We suggest that low right-left 2D:4D is linked to performance in some sports because it is a proxy of high sensitivity to prenatal and maybe also circulating testosterone and high VO2(max).

Enhanced diastolic reflections on arterial pressure pulse during exercise recovery.

During recovery from a maximal or submaximal aerobic exercise, augmentation of central (aortic) systolic pressure by reflected pressure waves is blunted in healthy humans. However, the extent to which reflected pressure waves modify the central pulse in diastole in these conditions remains unknown. We evaluated systolic and diastolic central reflected waves in 11 endurance-trained athletes on recovery from a maximal running test on a treadmill (treadmill-max) and a 4000 m run in field conditions. On both occasions in each subject, the radial pulse was recorded with applanation tonometry in the resting preexercise state and then 5, 15, 25, 35, and 45 min after exercise termination. From the central waveform, as reconstructed by application of a generalized transfer function, we computed a systolic (AIx) and a diastolic index (AId) of pressure augmentation by reflections. At 5 min, both indices were below preexercise. At further time-points, AIx remained low, while AId progressively increased, to overshoot above preexercise at 45 min. The same behavior was observed with both exercise types. Beyond the first few minutes of recovery following either maximal or submaximal aerobic exercise, reflected waves selectively augment the central pressure pulse in diastole, at least in endurance-trained athletes.

Counterexamples to some pointwise estimates of the maximal Cauchy transform in terms of the Cauchy transform

Motivated by the work of Mateu, Orobitg, Pérez and Verdera, who proved inequalities of the form $T_*f\lesssim M(Tf)$ or $T_*f\lesssim M^2(Tf)$ for certain singular integral operators $T$, such as the Hilbert or the Beurling transforms, we study the possibility of establishing this type of control for the Cauchy transform along a Lipschitz graph. We show that this is not possible in general, and we give a partial positive result when the graph is substituted by a Jordan curve.

Evaluation of the speed-oligo direct Mycobacterium tuberculosis assay for molecular detection of mycobacteria in clinical respiratory specimens.

We present the first evaluation of a novel molecular assay, the Speed-oligo Direct Mycobacterium tuberculosis (SO-DMT) assay, which is based on PCR combined with a dipstick for the detection of mycobacteria and the specific identification of M. tuberculosis complex (MTC) in respiratory specimens. A blind evaluation was carried out in two stages: first, under experimental conditions on convenience samples comprising 20 negative specimens, 44 smear- and culture-positive respiratory specimens, and 11 sputa inoculated with various mycobacterium-related organisms; and second, in the routine workflow of 566 fresh respiratory specimens (4.9% acid-fast bacillus [AFB] smear positives, 7.6% MTC positives, and 1.8% nontuberculous mycobacteria [NTM] culture positives) from two Mycobacterium laboratories. SO-DMT assay showed no reactivity in any of the mycobacterium-free specimens or in those with mycobacterium-related organisms. Compared to culture, the sensitivity in the selected smear-positive specimens was 0.91 (0.92 for MTC and 0.90 for NTM), and there was no molecular detection of NTM in a tuberculosis case or vice versa. With respect to culture and clinical data, the sensitivity, specificity, and positive and negative predictive values for the SO-DMT system in routine specimens were 0.76 (0.93 in smear positives [1.0 for MTC and 0.5 for NTM] and 0.56 in smear negatives [0.68 for MTC and 0.16 for NTM]), 0.99, 0.85 (1.00 in smear positives and 0.68 in smear negatives), and 0.97, respectively. Molecular misidentification of NTM cases occurred when testing 2 gastric aspirates from two children with clinically but not microbiologically confirmed lung tuberculosis. The SO-DMT assay appears to be a fast and easy alternative for detecting mycobacteria and differentiating MTC from NTM in smear-positive respiratory specimens.

Diagnostic yield of a PCR assay in focal complications of brucellosis.

In order to evaluate the diagnostic yield of a PCR assay for patients with focal complications of brucellosis, we studied by PCR and by conventional microbiological techniques 34 nonblood samples from 32 patients with different focal forms of brucellosis. The samples from patients with brucellosis were paired to an equal number of control samples from the same locations of patients whose illnesses had different etiologies. Thirty-three of the 34 nonblood samples (97%) from the brucellosis patients were positive by PCR, whereas Brucella spp. were isolated from only 29.4% of the conventional cultures. For 11.4% of the patients, the confirmatory serological tests were either negative or showed titers below the diagnostic range. Two patients (6.2%) from the control group, both with tuberculous vertebral osteomyelitis, had a positive PCR result. The brucella PCR of blood from these two patients was also positive, and the two strains of Mycobacterium tuberculosis isolated were analyzed by the brucella PCR, with no evidence of amplification. These results show that the PCR assay is far more sensitive than conventional cultures, and this, coupled with its speed and reduction in risk to laboratory workers, makes this technique a very useful tool for the diagnosis of focal complications of brucellosis.

Analytical expressions for the flame front speed in the downward combustion of thin solid fuels and comparison to experiments

We derive analytical expressions for the propagation speed of downward combustion fronts of thin solid fuels with a background flow initially at rest. The classical combustion model for thin solid fuels that consists of five coupled reaction-convection-diffusion equations is here reduced into a single equation with the gas temperature as the single variable. For doing so we apply a two-zone combustion model that divides the system into a preheating region and a pyrolyzing region. The speed of the combustion front is obtained after matching the temperature and its derivative at the location that separates both regions.We also derive a simplified version of this analytical expression expected to be valid for a wide range of cases. Flame front velocities predicted by our analyticalexpressions agree well with experimental data found in the literature for a large variety of cases and substantially improve the results obtained from a previous well-known analytical expression