Search Results
Results 251 - 300 of 804
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Rodríguez Hernán - - 2005
OBJECTIVE: Describing the behaviour of dengue and its vector in Cáqueza, Colombia (1746 masl) by serological, entomological and virological monitoring between March and June 2004. METHODS: Two types of study were carried out. One was a cross-sectional study for serologically monitoring the population and taking entomological indicators; participants were selected ...
Tsopelas Fotios N - - 2005
In this work the lipophilicity of different selenium species occurring in environmental matrices and food, Se(IV), Se(VI), selenomethionine (Se-Met), selenocystamine (Se-CM), selenocystine (Se-Cyst), and dimethyl diselenide (CH3)2Se2, was investigated in the octanol-water system, using the shaking flask method and detection with inductively coupled plasma-atomic emission spectrometry (ICP-AES), in order to ...
Powell Frank L - - 2004
We measured ventilation (VI) and arterial blood gases in Pekin ducks during acclimatization to 3800 m altitude for 1-90 days. Four experimental series were conducted over 4 years using both natural altitude and a hypobaric chamber. PaCO2 decreased to 3.5 Torr, relative to the value measured during acute hypoxia after ...
Muza Stephen R - - 2004
BACKGROUND: This study compared the distribution of arterial oxygen saturation (SaO2) and susceptibility to Acute Mountain Sickness (AMS) in moderate altitude residents (MAR) and low altitude residents (LAR) following rapid ascent to 4056 m. METHODS: Resting PETCO2 and SaO2 were measured in 38 subjects residing for > 3 mo near ...
Storey Kenneth B - - 2004
Peter W. Hochachka led a grand life of science adventure and left as his legacy a whole new field--biochemical adaptation. Oxygen was at the core of Peter's career and his laboratory made major contributions to our understanding of how animals deal with variation in oxygen availability in many forms. He ...
Böning D - - 2004
Total hemoglobin mass has not been systematically investigated in females at altitude. We measured this quantity (CO-rebreathing method) as well as peak oxygen uptake in 54 young women (age 22.5 +/- 0.6 SE years) with differing physical fitness living in Bogota (2600 m) and compared the results with those of ...
Wilber Randall L - - 2004
PURPOSE: To evaluate the effect of different fractions of inspired oxygen (FIO2) on oxidative stress during a high-intensity interval workout in trained endurance athletes residing at altitude. METHODS: Subjects (N = 19) were trained male cyclists who were residents of moderate altitude (1800-1900 m). Testing was conducted at 1860 m ...
Richalet Jean-Paul - - 2005
Exposure to high altitude induces pulmonary hypertension that may lead to life-threatening conditions. In a randomized, double-blind, placebo-controlled study, the effects of oral sildenafil on altitude-induced pulmonary hypertension and gas exchange in normal subjects were examined. Twelve subjects (sildenafil [SIL] n = 6; placebo [PLA] n = 6) were exposed ...
Webb James T - - 2004
INTRODUCTION: Over 80% altitude decompression sickness (DCS) was reported during a 4-h exposure with mild exercise to 7620 m (25,000 ft) without prebreathe. Prebreathe for more than 1 h would be necessary to reduce the DCS risk below 40%. Use of a single period of exercise to enhance prebreathe effectiveness ...
Baldwin Suzanne L - - 2004
As lithospheric plates are subducted, rocks are metamorphosed under high-pressure and ultrahigh-pressure conditions to produce eclogites and eclogite facies metamorphic rocks. Because chemical equilibrium is rarely fully achieved, eclogites may preserve in their distinctive mineral assemblages and textures a record of the pressures, temperatures and deformation the rock was subjected ...
Winters William R - - 2004
We examined a large (240 km2) northern Appalachian bituminous coal basin (Irwin Syncline, Westmoreland County, Pennsylvania) comprising 27 mine complexes with nine major (> 2.5 x 10(3) L/min) discharges. The synclinal basin was divided into seven subbasins based on equilibrium hydraulic relationships established during the past 25 years. Recharge rates, ...
Choukèr Alexander - - 2005
To test the hypothesis of whether strenuous physical exercise inhibits neutrophils that can get activated by hypobaric hypoxia, we analyzed the effects of both high altitude and strenuous exercise alone and in combination on potentially cytotoxic functions of granulocytes in healthy volunteers (n = 12 men; average age 27.6 yr; ...
Warren Charles R - - 2004
The internal conductance to CO(2) supply from substomatal cavities to sites of carboxylation may pose a large limitation to photosynthesis, but little is known of how it is affected by nutrient supply. Knowing how internal conductance responds to nutrient supply is critical for interpreting the biochemical responses from A-C(i) curves. ...
León-Velarde F - - 2004
Avian embryos at high altitude do not benefit of the maternal protection against hypoxia as in mammals. Nevertheless, avian embryos are known to hatch successfully at altitudes between 4,000 and 6,500 m. This review considers some of the processes that bring about the outstanding modifications in the pressure differences between ...
Ghofrani Hossein A - - 2004
BACKGROUND: Alveolar hypoxia causes pulmonary hypertension and enhanced right ventricular afterload, which may impair exercise tolerance. The phosphodiesterase-5 inhibitor sildenafil has been reported to cause pulmonary vasodilatation. OBJECTIVE: To investigate the effects of sildenafil on exercise capacity under conditions of hypoxic pulmonary hypertension. DESIGN: Randomized, double-blind, placebo-controlled crossover study. SETTING: ...
Ikemoto Tokutaka - - 2004
Distribution of Cu, Zn, Cd, Ag, Hg, and Se were determined in hepatocytosol of northern fur seals (Callorhinus ursinus), black-footed albatrosses (Diomedea nigripes), and Dall's porpoises (Phocoenoides dalli). Copper, Zn, and Cd were accumulated preferentially in metallothionein (MT) fraction and their contents in MT fraction increased with the amounts in ...
Ashenden Michael J - - 2004
This study reports blood model scores used for detection of recombinant human erythropoietin (rHuEPO) abuse by athletes. Elite female rowers were monitored prior to their World Championships, including a period spent training at moderate altitude. In contrast to previous results, no substantial increase in model scores was found following altitude ...
Bajaj Monika - - 2004
OBJECTIVE: To audit the gentamicin usage guidelines due to concerns that it resulted in too many sub-therapeutic peak levels, devise a new guideline and re-audit after change in practise. METHOD: A prospective audit of 50 sets of gentamicin levels on the Old Gentamicin Regime was conducted. Desired levels were a ...
Erba P - - 2004
The purpose of the study was to investigate determinants of acute mountain sickness after rapid ascent to high altitude. A total of 21 climbers were studied ascending from <1,200 m to Capanna Regina Margherita, a hut in the Alps at 4,559 m, within <24 h. During their overnight stay at ...
Savourey Gustave - - 2004
Erythropoiesis was studied in 11 subjects submitted to a 4-h hypoxia (HH) in a hypobaric chamber (4,500 m, barometric pressure 58.9 kPa) both before and after a 3-week sojourn in the Andes. On return to sea level, increased red blood cells (+3.27%), packed cell volume (+4.76%), haemoglobin (+6.55%) ( P<0.05), ...
Weitz Charles A - - 2004
Han Chinese of low-altitude descent have been living in Qinghai Province of Western China for at least two millennia. For most of this time they have lived at elevations under 2,500 m. However, during the last four decades an increasing number of Han have moved into high-altitude towns at elevations ...
Rezende Enrico L - - 2004
Metabolic rate is a key aspect of organismal biology and the identification of selective factors that have led to species differences is a major goal of evolutionary physiology. We tested whether environmental characteristics and/or diet were significant predictors of interspecific variation in rodent metabolic rates. Mass-specific basal metabolic rates (BMR) ...
Meyer C - - 2004
A 4-year-old Thoroughbred gelding racehorse was referred to the Onderstepoort Veterinary Academic Hospital (OVAH) with a history of post-race distress and collapse. In the absence of any obvious abnormalities in the preceding diagnostic work-up, a standard exercise test was performed to determine an underlying cause for the post-race distress reported. ...
Calbet José A L - - 2004
With altitude acclimatization, blood hemoglobin concentration increases while plasma volume (PV) and maximal cardiac output (Qmax) decrease. This investigation aimed to determine whether reduction of Qmax at altitude is due to low circulating blood volume (BV). Eight Danish lowlanders (3 females, 5 males: age 24.0 +/- 0.6 yr; mean +/- ...
Muza Stephen R - - 2004
BACKGROUND: Acute Mountain Sickness (AMS) is a multi-system disorder that is characterized by headache, anorexia, nausea, vomiting, insomnia, lassitude, and malaise. The syndrome is common in unacclimatized low altitude residents who rapidly ascend to terrestrial elevations exceeding 2,500 m. AMS may be a manifestation of hypoxia-induced cerebral edema resulting, in ...
Louie Dianna - - 2004
Exercised-induced asthma is not due to exercise itself per se, but rather is due to cooling and/or drying of the airway because of the increased ventilation that accompanies exercise. Travel to high altitudes is accompanied by increased ventilation of cool, often dry, air, irrespective of the level of exertion, and ...
Brutsaert Tom D - - 2004
Forced vital capacity (FVC) and maximal exercise response were measured in two populations of Peruvian males (age, 18-35 years) at 4,338 m who differed by the environment in which they were born and raised, i.e., high altitude (Cerro de Pasco, Peru, BHA, n = 39) and sea level (Lima, Peru, ...
Turchyn Alexandra V - - 2004
Oxygen isotopes in marine sulfate (delta18O(SO4)) measured in marine barite show variability over the past 10 million years, including a 5 per mil decrease during the Plio-Pleistocene, with near-constant values during the Miocene that are slightly enriched over the modern ocean. A numerical model suggests that sea level fluctuations during ...
Aughey R J - - 2005
Athletes commonly attempt to enhance performance by training in normoxia but sleeping in hypoxia [live high and train low (LHTL)]. However, chronic hypoxia reduces muscle Na(+)-K(+)-ATPase content, whereas fatiguing contractions reduce Na(+)-K(+)-ATPase activity, which each may impair performance. We examined whether LHTL and intense exercise would decrease muscle Na(+)-K(+)-ATPase activity ...
Pisitkun T - - 2004
Convective-controlled double high flux hemodiafiltration (CC-DHF) was set-up using two high flux dialyzers. The convection occurred in the first while the fluid replacement took place in the second dialyzer. The system of CC-DHF basically resembled that of hemodiafiltration. CC-DHF was performed in 9 chronic hemodialysis Thai patients who had been ...
Beidleman Beth A - - 2004
Acute mountain sickness (AMS) commonly occurs at altitudes exceeding 2000-2500 m and usually resolves after acclimatization induced by a few days of chronic residence at the same altitude. Increased ventilation and diuresis may contribute to the reduction in AMS with altitude acclimatization. The aim of the present study was to ...
Labocha Marta K - - 2004
Basal metabolic rate (BMR) is a fundamental energetic trait and has been measured in hundreds of birds and mammals. Nevertheless, little is known about the consistency of the population-average BMR or its repeatability at the level of individual variation. Here, we report that average mass-independent BMR did not differ between ...
Marconi Claudio - - 2004
Tibetan highlanders develop at altitude peak aerobic power levels close to those of Caucasians at sea level. In order to establish whether this feature is genetic and, as a consequence, retained by Tibetan lowlanders, altitude-induced changes of peak aerobic performance were assessed in four groups of volunteers with different ethnic, ...
Linneweber J - - 2004
OBJECTIVE: The Baylor Gyro BVAD is under development with the final goal of establishing a totally implantable biventricular assist system (BVAD). The aim of this study was to evaluate the safety, reliability, and effectiveness of the device in a long-term in vivo model. METHODS: The BVAD was implanted into eight ...
Entin Pauline L - - 2004
Although exercise during pregnancy has been shown to be safe and is now recommended by the American College of Obstetricians and Gynecologists and the Society of Obstetricians and Gynaecologists of Canada for all healthy women, little is known about the combined effects of high altitude and exercise during pregnancy. Due ...
Wu Tianyi - - 2004
Chronic mountain sickness (CMS) and high altitude pulmonary edema (HAPE) each occur rarely in Tibetans, and they have previously not been reported in the same person. Here we describe a 37-year-old native Tibetan man with CMS at 4300 m, who developed HAPE after his return home from a 12-day visit ...
Kleinsasser Axel - - 2004
Reducing the work of breathing (WOB) during exercise and thus the oxygen required solely for ventilation may be an option to increase the oxygen available for nonventilatory physiological tasks at altitude. This study evaluated whether pressure support ventilation (PSV) and proportional assist ventilation (PAV) may partially reduce WOB during exercise ...
O'Connor Terry - - 2004
Acute mountain sickness (AMS) is a common condition in individuals who travel to altitudes over 2000 m. While AMS is an important public health problem, no measurements can reliably support or predict the diagnosis with any degree of confidence. We therefore set out to study whether pulse oximetry data are ...
Brutsaert Tom D - - 2004
This study tested the hypothesis that Andean natives are adapted to high altitude (HA) via high work efficiency during exercise in hypoxia. A total of 186 young males and females were tested in Bolivia, comprising eight different subject groups. Groups were identified based on gender, ancestry (Aymara vs. European), altitude ...
Jefferson J Ashley - - 2004
The generation of reactive oxygen species is typically associated with hyperoxia and ischemia reperfusion. Recent evidence has suggested that increased oxidative stress may occur with hypoxia. We hypothesized that oxidative stress would be increased in subjects exposed to high altitude hypoxia. We studied 28 control subjects living in Lima, Peru ...
Saunders P U - - 2004
To investigate the effect of altitude exposure on running economy (RE), 22 elite distance runners [maximal O(2) consumption (Vo(2)) 72.8 +/- 4.4 ml x kg(-1) x min(-1); training volume 128 +/- 27 km/wk], who were homogenous for maximal Vo(2) and training, were assigned to one of three groups: live high ...
Pollock Neal W - - 2003
BACKGROUND: Postdive altitude exposure increases the risk of decompression sickness (DCS). Certain training and operational situations may require U.S. Special Operations Forces (SOF) personnel to conduct high altitude parachute operations after diving. Problematically, the minimum safe preflight surface intervals (PFSI) between diving and high altitude flying are not known. METHODS: ...
Mazzeo Robert S - - 2003
This investigation examined the influence of alpha-adrenergic blockade on plasma and urinary catecholamine responses to both exercise and high-altitude exposure. Sixteen nonsmoking, eumenorrheic women (age 23.2 +/- 1.4 years, 68.7 +/- 1.0 kg) were studied at sea level and during 12 days of high-altitude exposure (4,300 m). Subjects received either ...
van Dijk Pim - - 2003
The physiological vulnerability of distortion product otoacoustic emissions (DPOAEs) was investigated in the leopard frog, Rana pipiens pipiens. For each frog, DPOAEs were recorded from the amphibian and the basilar papillae. Measurements were taken before and after either the arrest of oxygen supply due to cardioectomy, or the destruction of ...
Pilmanis Andrew A - - 2003
INTRODUCTION: Loss of aircraft cabin pressurization can result in very rapid decompression rates. The literature contains reports of increased or unchanged levels of altitude decompression sickness (DCS) resulting from increasing the rate of decompression. We conducted two prospective exposure profiles to quantify the DCS risk at 12,192 m (40,000 ft), ...
Ashenden Michael J - - 2003
BACKGROUND AND OBJECTIVES: ON- and OFF-model scores derived from blood parameters sensitive to erythropoiesis have been shown to be a useful tool to identify athletes who are currently injecting erythropoietin to enhance performance or those who have recently stopped doing so. We investigated changes in blood parameters and model scores ...
Zhong-Yuan Shi - - 2003
The simulated dive experiments were conducted at the high altitude of 4500 meters and 5000 meters, for the requirement of diving operation in the lakes at the altitude of 4442 meters for the construction of large-scale hydroelectric power station. The high & low pressure chamber-complex was used, and 15 professional ...
Dilharreguy Bixente - - 2003
Experimental and modeling studies were used to estimate the effect of different sampling rates (repetition times, TR) and different sampling positions on the estimates of the temporal properties of the hemodynamic response function (HRF) derived from fMRI studies. Data were acquired at a TR of 250 ms and then subjected ...
Russell Michael F - - 2003
An analytical method for determining the quality and hence the chemical variety status of tea tree transplants is described. The key to the procedure was found to be the leaf age of the test material. Investigation at very early development stages was seen to give misleading results due to the ...
Beidleman Beth A - - 2003
Chronic altitude residence improves muscular performance at altitude, but the effect of intermittent altitude exposures (IAE) on muscular performance at altitude has not been defined. The purpose of this study was to determine the effects of 3 wk of IAE, in combination with rest and cycle training, on muscular performance ...
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