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Chapman Robert F - - 2010
Winter sports events routinely take place at low to moderate altitudes, and nearly all Winter Olympic Games have had at least one venue at an altitude >1000 m. The acute and chronic effects of altitude can have a substantial effect on performance outcomes. Acutely, the decline in oxygen delivery to ...
Cai Ming-Chun - - 2010
Cardiac muscle adaptation is essential for maintaining physical capacity after ascending to high altitude. This study examines the effects of high altitude training on myocardial metabolic enzyme activity and composition of alpha-myosin heavy chain (MHC). Rats were randomly divided into normobaric sedentary (NS) and training (NT) groups, and hypobaric sedentary ...
Gassmann Max - - 2009
Numerous factors involved in general homeostasis are able to modulate ventilation. Classically, this comprises several kind of molecules, including neurotransmitters and steroids that are necessary for fine tuning ventilation under different conditions such as sleep, exercise, and acclimatization to high altitude. Recently, however, we have found that erythropoietin (Epo), the ...
Fischler Manuel - - 2009
RATIONALE: Whether pulmonary hypertension at high altitude limits exercise capacity remains uncertain. OBJECTIVES: To gain further insight into the pathophysiology of hypoxia induced pulmonary hypertension and the resulting reduction in exercise capacity, we investigated if the reduction in hypoxic pulmonary vasoconstrictive response with corticosteroids or phosphodiesterase-5 inhibition improves exercise capacity. ...
Beidleman Beth A - - 2009
PURPOSE: This study examined the effect of 1 wk of normobaric intermittent hypoxic exposure (IHE) combined with exercise training on endurance performance at a 4300-m altitude (HA). METHODS: Seventeen male lowlanders were divided into an IHE (n = 11) or SHAM (n = 6) group. Each completed cycle endurance testing ...
Heinicke Ilmar - - 2009
Oxidative stress occurs at altitude, and physical exertion might enhance this stress. In the present study, we investigated the combined effects of exercise and moderate altitude on redox balance in ten endurance exercising biathletes, and five sedentary volunteers during a 6-week-stay at 2,800 m. As a marker for oxidative stress, ...
Lalande Sophie S Division of Cardiovascular Diseases, Mayo Clinic, College of Medicine, Rochester, MN 55905, USA. - - 2009
The reduced arterial oxygen tension at high altitude impairs the ability to work. Acetazolamide improves arterial oxygen saturation (SaO(2)) by increasing ventilation but is associated with an increased work and cost of breathing. Depending on the settings, sildenafil can also increases SaO(2) possibly through a reduction in pulmonary hypertension and ...
Clark Sally A - - 2009
The aim of this study was to determine the time course of changes in haemoglobin mass (Hb(mass)) in well-trained cyclists in response to live high:train low (LHTL). Twelve well-trained male cyclists participated in a 3-week LHTL protocol comprising 3,000 m simulated altitude for ~14 h/day. Prior to LHTL duplicate baseline ...
Kelly Paul T - - 2009
INTRODUCTION: Exposure to altitude invariably involves some form of physical activity. There are limited data available to help predict the response to activity at altitude in patients with chronic obstructive pulmonary disease (COPD). The aim of the present study was to investigate the response to acute altitude exposure at rest ...
van Hall G - - 2009
Chronic hypoxia has been proposed to induce a closer coupling in human skeletal muscle between ATP utilization and production in both lowlanders (LN) acclimatizing to high altitude and high-altitude natives (HAN), linked with an improved match between pyruvate availability and its use in mitochondrial respiration. This should result in less ...
Saunders Philo U - - 2009
Since the 1968 Olympic Games when the effects of altitude on endurance performance became evident, moderate altitude training ( approximately 2000 to 3000 m) has become popular to improve competition performance both at altitude and sea level. When endurance athletes are exposed acutely to moderate altitude, a number of physiological ...
Paolinelis George - - 2009
Air-abrasion is a tooth preparation technology developed in the 1940s that is currently gaining popularity due to its compatibility with adhesive restorations. Variables, including propellant pressure, powder flow rate, nozzle angle and distance to the tooth surface abrasion time, can affect the cutting rate of the air-abrasion unit. A static ...
Beidleman Beth A - - 2009
This study determined the effectiveness of 6 days (d) of staging at 2200 m on physiologic adjustments and acute mountain sickness (AMS) during rapid, high-risk ascent to 4300 m. Eleven sea-level (SL) resident men (means +/- SD; 21 +/- 3 yr; 78 +/- 13 kg) completed resting measures of end-tidal ...
Voinovich D - - 2009
Simultaneous improvement of solubilization kinetics of main flavolignans of Silybum marianum extract was obtained cogrinding with two crosslinked polymers: micronized crospovidone, PVP-CL(R) and sodium carboxymethylcellulose, Ac-Di-Sol(R) in the 1:3 active-to-polymer weight ratio. By this process it was assessed that the main extract components lost its crystalline structure, and the powder ...
Martin Daniel S - - 2009
We sought to quantify changes in skeletal muscle oxygenation during exercise using near-infrared spectroscopy (NIRS) in healthy volunteers ascending to high altitude. Using NIRS, skeletal muscle tissue oxygen saturation (StO2) was measured in the vastus lateralis of 24 subjects. Measurements were performed at sea level (SL; 75 m), at 3,500 ...
Mutikainen Sara S Department of Health Sciences, University of Jyväskylä , Jyväskylä, - - 2009
Previous studies have shown that athletic training or other physical activity causes structural and functional adaptations in the heart, but less is known how long-term physical activity affects heart when genetic liability and childhood environment are taken into account. The aim of this study was to investigate the effects of ...
Pomidori Luca L Centro Studi Biomedici Applicati allo Sport Università di Ferrara, Italy. - - 2009
The oxygen saturation values reported in the high altitude literature are usually taken during a few minutes of measurement either at rest or during exercise. We aimed to investigate the daily hypoxic profile by monitoring oxygen saturation for 24 h in 8 lowlanders (4 females, ages 26 to 59) during ...
Eisenman I - - 2009
In light of the rapid recent retreat of Arctic sea ice, a number of studies have discussed the possibility of a critical threshold (or "tipping point") beyond which the ice-albedo feedback causes the ice cover to melt away in an irreversible process. The focus has typically been centered on the ...
Bauer A - - 2008
The objective of this study was to examine microvascular perfusion during hypobaric hypoxia and physical exercise. We used orthogonal polarization spectral imaging for the non-invasive visualization and assessment of the sublingual mucosal microcirculation in twelve healthy altitude acclimatized mountaineers. Red blood cell velocity (RCV), microvascular diameter (Dia), functional capillary density ...
Zechmeister Harald G - - 2008
To evaluate a new N-monitoring program in the framework of the UN-ECE ICP-Vegetation program using mosses as bioindicators, 490 moss samples were collected at 220 sites in Austria and analyzed for total N (N content) and delta(15)N signatures. Within-site variability of N content and delta(15)N signatures was tested for the ...
Viana Priscilla Z - - 2008
Cd, Cr, Pb, Ag, As, Ba, Hg, CH3Hg, and CN transport through sand, granular activated carbon (GAC), organoclay, shredded tires, and apatite caps was modeled by deterministic and Monte Carlo methods. Time to 10% breakthrough, 30 and 100 yr cumulative release were metrics of effectiveness. Effective caps prevented above-cap concentrations ...
Gibelli Giuseppe - - 2008
BACKGROUND: Altitude-induced sympathetic hyperactivity can elicit rhythm disturbances in healthy subjects, in particular during exercise. AIM: To asses the real susceptibility of healthy myocardium to malignant ventricular arrhythmias during exercise at high altitude using microvolt T-wave alternans (MTWA). METHODS: We evaluated eight healthy trained participants (one female, 42 +/- 9 ...
Umar Ahmad - - 2009
High-aspect-ratio ZnO nanowires based ultra-sensitive hydrazine amperometric sensor has been fabricated which showed a high and reproducible sensitivity of 12.76 microAcm(-2)nM(-1), detection limit, based on S/N ratio, 84.7 nM, response time less than 5s, linear range from 500 to 1200 nM and correlation coefficient of R=0.9989. This is the first ...
Munir Muhammad Miftahul - - 2008
A constant-current electrospinning system has been successfully developed to produce high quality nanofibers. In order to keep at a certain value of the electric current, a proportional integral-derivative (PID) control action was employed, in which the PID parameters were manually tuned. The desired value of electric current was quickly achieved ...
Gore C J - - 2008
Analysis of approximately 100 years of home-and-away South American World Cup matches illustrate that football competition at moderate/high altitude (>2000 m) favors the home team, although this is more than compensated by the likelihood of sea-level teams winning at home against the same opponents who have descended from altitude. Nevertheless, ...
Stray-Gundersen J - - 2008
For decades altitude training has been used by endurance athletes and coaches to enhance sea-level performance. Whether altitude training does, in fact, enhance sea level performance and, if so, by what means has been the subject of a number of investigations. Data produced principally by Levine and Stray-Gundersen have shown ...
Schmidt W - - 2008
It is controversially discussed whether soccer games should be played at moderate (2001-3000 m) and high altitudes (3001-5500 m) or should be restricted to near sea level and low altitude (501-2000 m) conditions. Athletes living at altitude are assumed to have a performance advantage compared with lowlanders. One advantage of ...
Levine B D - - 2008
Altitude will impact football performance through two separate and parallel pathways related to the hypobaric (physical) and hypoxic (physiological) components of terrestrial altitude: (a) the decrease in partial pressure of oxygen reduces maximal oxygen uptake and impairs "aerobic" performance by reducing maximal aerobic power, increasing the relative intensity of any ...
Richalet J-P - - 2008
The increase in oxygen transport elicited by several weeks of exposure to moderate to high altitude is used to increase physical performance when returning to sea level. However, many studies have shown that aerobic performance may not increase at sea level after a training block at high altitude. Subsequently, the ...
Urban Otmar - - 2008
We tested the hypothesis that leaf age affects photosynthetic induction, because conductance to CO2 diffusion usually decreases with increasing leaf age. Photosynthetic inductions, primarily determined by the light modulation of Rubisco activity and stomatal opening, were investigated in both young and mature leaves, as defined by leaf plastochron index (LPI), ...
Ando S - - 2008
We examined the effects of acute exercise on reaction time to visual stimuli presented in the central portion and periphery of the visual field. Twelve participants performed reaction time tasks at rest and during cycling at 65 % peak oxygen uptake in two visual conditions. We used circular black-and-white checkerboard ...
Donroe Joseph A - - 2008
Two cross-sectional studies in a high altitude region of Perú evaluated the role of pulse oximetry for detection of silicosis in high-altitude miners. In study one, exercise pulse oximetry and chest radiographs were used to evaluate 343 silica-exposed miners and 141 unexposed subjects for evidence of silicosis. Study 2 investigated ...
Brutsaert Tom D - - 2008
Natives of high altitude (HA) may have enhanced physical work capacity in hypoxia due to growth and development at altitude or, in the case of indigenous Andean and Himalayan residents, due to population genetic factors that determine higher limits to exercise performance. There is a growing scientific literature in support ...
Agostoni Piergiuseppe - - 2008
BACKGROUND: At sea level, ventilation kinetics are characterized during a ramp exercise by three progressively steeper slopes, the first from the beginning of exercise to anaerobic threshold, the second from anaerobic threshold to respiratory compensation point, and the third from respiratory compensation point to peak exercise. In the second ventilation ...
Bosch Martina M - - 2008
OBJECTIVES: To determine the incidence of optic disc swelling as a possible indicator of cerebral edema in a large group of healthy mountaineers exposed to very high altitudes and to correlate these findings with various clinical and environmental factors and occurrence of acute mountain sickness and high-altitude cerebral edema. METHODS: ...
Burtscher M - - 2008
Acute exposure to high altitude provokes the development of mountain illnesses and decrease of exercise performance. Thus, sufficient acclimatization is of utmost importance for mountaineers, trekkers, and athletes performing at high altitude. The main purpose of this paper was to review existing studies and observations on the effectiveness of preacclimatization ...
Zizek Suzana - - 2008
Experiments to determine the mercury methylation potential were performed on sediments from two locations on the river Idrijca (Slovenia), differing in ambient mercury concentrations. The tracer used was the radioactive isotope (197)Hg. The benefit of using this tracer is its high specific activity, which enables spikes as low as 0.02 ...
Tansey Etain A - - 2008
Many pathological conditions exist where tissues exhibit hypoxia or low oxygen tension. Hypoxic hypoxia arises when there is a reduction in the amount of oxygen entering the blood and occurs in healthy people at high altitude. In 1946, research sponsored by the United States Navy led to the collection and ...
Saunders P U - - 2009
There is conflicting evidence whether hypoxia improves running economy (RE), maximal O(2) uptake (V(O)(2max)), haemoglobin mass (Hb(mass)) and performance, and what total accumulated dose is necessary for effective adaptation. The aim of this study was to determine the effect of an extended hypoxic exposure on these physiological and performance measures. ...
Scarborough John E - - 2008
BACKGROUND: We wanted to determine whether current levels of fellowship training in hepato-pancreato-biliary (HPB) surgery will be sufficient to meet demand for HPB procedures in 2020. STUDY DESIGN: The Nationwide Inpatient Sample database for 1988 through 2003 was used to construct projections for the number of HPB procedures that will ...
Lapucki Tomasz - - 2008
Survival, haemolymph osmolality and the specific metabolic rate of the isopod Idotea chelipes from the brackish waters of the southern Baltic Sea (salinity 7 psu) were investigated after acclimation to different salinities in the range of 3-30 psu keeping other parameters constant (T=15 degrees C, full air saturation). Haemolymph osmolality ...
Böning D - - 2008
The assumption that buffering at altitude is deteriorated by bicarbonate (bi) reduction was investigated. Extracellular pH defense against lactic acidosis was estimated from changes (Delta) in lactic acid ([La]), [HCO3-], pH and PCO2 in plasma, which equilibrates with interstitial fluid. These quantities were measured in earlobe blood during and after ...
Mazzeo Robert S - - 2008
Studies performed over the past decade have yielded new information related to the physiological and metabolic adjustments made in response to both short- and long-term high-altitude exposure. These investigations have examined the potential mechanisms responsible for the alterations observed in such key variables as heart rate, stroke volume, cardiac output, ...
Huang Hsien-Hao - - 2008
PURPOSE: Oxidative stress and erythropoietin (EPO) levels are increased following high altitude exposure. We hypothesized that the altitude-oxidative stress and EPO response would be associated with the presence or absence of acute mountain sickness (AMS) in subjects exposed at high altitude. METHODS: The study enrolled 29 healthy volunteers exposed at ...
Beidleman Beth A - - 2008
PURPOSE: The purpose of this study was to determine whether seven intermittent altitude exposures (IAE), in combination with either rest or exercise training, improves time-trial exercise performance and induces physiologic adaptations consistent with chronic altitude adaptation at 4300 m. METHODS: Ten adult lowlanders (26 +/- 2 yr; 78 +/- 4 ...
Kapala Jacek - - 2008
The measurements of radioactive caesium contents in bottom sediments were carried out in four lakes. First samples (47) were taken in 1992-95. The repeat sampling (109) was performed from the same places in 2005. We examined eight chosen areas in these lakes. In six of them, we observed statistically significant ...
Woods D R - - 2008
OBJECTIVE: To investigate the cause and nature of palpitations occurring at high altitude. METHODS: Implantable loop recorders were inserted subcutaneously in the left pectoral region of 9 healthy male volunteers. Subjects flew to Kathmandu (1,250 m) and then Lukla (2,800 m) before immediately commencing an identical ascent and descent profile ...
Myers Stephen D - - 2008
OBJECTIVE: To test the hypothesis that acclimatization to high altitude results in an improvement of the ventilatory threshold (VT). METHODS: Eight lowlanders underwent cardiopulmonary exercise testing with a cycle ergometer to determine VT and peak oxygen uptake (Vo2peak) in Coventry, United Kingdom (altitude: 80 m), on arrival in leh, india ...
Imray Chris H E - - 2008
Recent studies in normal participants have shown that right to left shunt blood vessels in the lung open up during exercise. We describe the first field study to investigate this phenomenon at altitude. This study aimed to assess the effect of altitude and partial acclimatization on inducible right to left ...
Loeppky Jack A - - 2008
Hypoxemia is usually associated with acute mountain sickness (AMS), but most studies have varied in time and magnitude of altitude exposure, exercise, diet, environmental conditions, and severity of pulmonary edema. We wished to determine whether hypoxemia occurred early in subjects who developed subsequent AMS while resting at a simulated altitude ...
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