Effects Of Aerobic Conditions Research Articles

A genome-scale metabolic network of the aroma bacterium Leuconostoc mesenteroides subsp. cremoris.

Leuconostoc mesenteroides subsp. cremoris is an obligate heterolactic fermentative lactic acid bacterium that is mostly used in industrial dairy fermentations. The phosphoketolase pathway (PKP) is a unique feature of the obligate heterolactic fermentation, which leads to the production of lactate, ethanol, and/or acetate, and the final product profile of PKP highly depends on the energetics and redox state of the organism. Another characteristic of the L. mesenteroides subsp. cremoris is the production of aroma compounds in dairy fermentation, such as in cheese production, through the utilization of citrate. Considering its importance in dairy fermentation, a detailed metabolic characterization of the organism is necessary for its more efficient use in the industry. To this aim, a genome-scale metabolic model of dairy-origin L. mesenteroides subsp. cremoris ATCC 19254 (iLM.c559) was reconstructed to explain the energetics and redox state mechanisms of the organism in full detail. The model includes 559 genes governing 1088 reactions between 1129 metabolites, and the reactions cover citrate utilization and citrate-related flavor metabolism. The model was validated by simulating co-metabolism of glucose and citrate and comparing the in silico results to our experimental results. Model simulations further showed that, in co-metabolism of citrate and glucose, no flavor compounds were produced when citrate could stimulate the formation of biomass. Significant amounts of flavor metabolites (e.g., diacetyl and acetoin) were only produced when citrate could not enhance growth, which suggests that flavor formation only occurs under carbon and ATP excess. The effects of aerobic conditions and different carbon sources on product profiles and growth were also investigated using the reconstructed model. The analyses provided further insights for the growth stimulation and flavor formation mechanisms of the organism.

Effects of Aerobic Conditioning on Individuals Post-Stroke: What Is the Evidence?

Background: Stroke has been considered the major cause of chronic disability in the world and ranks among the leading causes of death. Despite the fact that new vascular events often happen and risk factors are the same that Cardiovascular Diseases, secondary prevention through non-pharmacological measures, are not part of the routine physical rehabilitation after stroke. Objective: The aim is to answer the following clinical question: Should aerobic fitness be part of the physical rehabilitation of individuals post-stroke? Methodological Design: The methodology used in the study was an integrative literature review. Inclusion Criteria: Articles in English are published in secondary databases: systematic reviews with or without meta-analysis, which address the question PICO: patient (post-stroke), intervention (aerobic exercise), comparison (with or without aerobic conditioning) the outcome (volume of oxygen consumed peak (VO2peak), quality of life (QoL), morbidity and mortality). Outcomes: VO2peak, QoL, complications and mortality. Analysis of Studies: The methodological quality of included studies is assessed using the tools: PRISMA and R-AMSTAR. Results: There was “good” evidence for the inclusion of aerobic exercise on physical rehabilitation of post-stroke individuals to improve their physical capacity (VO2peak), facilitating the completion of activities of daily living and gait. There was weak evidence on the association of aerobic fitness with positive results on QoL in stroke victims and insufficient results to evaluate the effect of aerobic fitness on the risk of stroke recurrence and mortality. Conclusion: The aerobic conditioning should be included in the rehabilitation of stroke victims.

The effect of Aerobic Conditioning on Cardiovascular and Respiratory Recovery in Normobaric Hypoxia

PURPOSE: The purpose of this study was to determine differences in post-exercise oxygen consumption, cerebral oxygenation, heart rate (HR), minute ventilation (VE), between aerobically fit and unfit young males acutely following exercise in hypoxia compared to normoxia. METHODS: Apparently healthy college age males took part in two trials consisting of normobaric normoxia (21% oxygen) and normobaric hypoxia (12% oxygen). Fit (n = 3; VO2max = 51.5 ml • kg-1 • min-1 ± 3.1) and unfit (n = 3; VO2max = 34.4 ml kg-1 min-1 ± 5.6) males cycled at 50% of altitude adjusted VO2max (-26% of normoxic VO2max) for 1-hr after a 2-hr baseline. Data was collected at baseline, 5 min prior to the end of exercise and again at 5 and 60 min after the end of exercise. RESULTS: An interaction effect (trial x time x fitness) revealed significance in the change of cerebral oxygenation over the course of the recovery period. In fact, the unfit group demonstrated a significantly smaller change (P <0.05) change in cerebral oxygenation immediately post-exercise (-4.3% ± 2.2) compared to fit individuals (-22.0% ± 2.6). Change in cerebral oxygenation at the same time point during the normoxic trial was not significantly different (Fit = 10.7% ± 5.9, Unfit = 5.7% ± 2.6; P > 0.05). In addition, percent change of O2 consumption post-exercise (compared to baseline) was significantly greater in the unfit group in the hypoxic trial (Unfit = 121.1% ± 4.0, Fit = 70.1% ± 16.3; P < 0.05), but no significant difference was demonstrated during the normoxic trial. VE and HR were significantly different between the trials in all subjects but not between groups (P < 0.05). VE was greater during hypoxia (P < 0.05) in all subjects while the fit group demonstrated a significantly higher VE during exercise in hypoxia (P < 0.05) compared to unfit individuals. CONCLUSIONS: The data suggests that when exposed to hypoxia aerobic conditioning may have an affect on acute recovery responses to exercise in hypoxia. Future research may examine changes in the recovery response to exercise after acclimatization to hypoxic environments.

Effect of aerobic conditioning on ventricular activation: A principal components analysis approach to high-resolution electrocardiogram

BackgroundThe athlete's heart represents a reversible structural and functional adaptations of myocardial tissue developed through physical conditioning. Surface electrocardiogram (ECG) has the capability to detect myocardial hypertrophy but has limited performance in monitoring physical conditioning-induced myocardial remodeling. The aim of this study was to develop an ECG-derived test for detecting incipient myocardial hypertrophy in well-conditioned athletes based on a principal components (PC) analysis. MethodsTwo groups of study composed of 14 sedentary healthy volunteers (Control group) and 14 professional long distance runners (Athlete group) had their maximal metabolic equivalents (MET) estimated (mean±SD: Control group: 9±2 METs vs. Athlete group: 20±1 METs, p<0.05). All participants had their high-resolution ECG (HRECG) recorded, and a 120ms segment starting at the QRS complex onset and ending in the ST segment was extracted to build a data matrix for PC analysis. The Mahalanobis distance was evaluated by a logistic regression model to determine the optimal separation threshold between groups. HRECG was also analyzed using the classical time domain approach. The comparison of areas under the receiver operating characteristic curve (c-statistic) in 10,000 bootstrap re-samplings measured how well each method detected physical conditioning (α<0.05). ResultsAverage bootstrap c-statistic for PC analysis and time domain approaches were 0.98 and 0.79 (p<0.05), respectively. PC analysis and maximal oxygen consumption exhibited comparable performances to distinguish between groups. DiscussionThe PC analysis method applied to HRECG signals appropriately discriminates well-conditioned athletes from healthy, sedentary subjects.

Effects of aerobic conditioning on cardiovascular sympathetic response to and recovery from challenge

Exercise has widely documented cardioprotective effects, but the mechanisms behind these effects are still poorly understood. Here, we test the hypothesis that aerobic training lowers cardiovascular sympathetic responses to and speeds recovery from challenge. We conducted a randomized, controlled trial contrasting aerobic versus strength training on indices of cardiac (pre-ejection period, PEP) and vascular (low-frequency blood pressure variability, LF-BPV) sympathetic responses to and recovery from psychological and orthostatic challenge in 149 young, healthy, sedentary adults. Aerobic and strength training did not alter PEP or LF-BPV reactivity to or recovery from challenge. These findings, from a large randomized, controlled trial using an intent-to-treat design, show that moderate aerobic exercise training has no effect on PEP and LF-BPV reactivity to or recovery from psychological or orthostatic challenge. In healthy young adults, the cardioprotective effects of exercise training are unlikely to be mediated by changes in sympathetic activity.

The effect of aerobic conditions on the complexation ability between mercury and humic acid from landfill leachate and its implication for the environment

Three-dimensional excitation emission matrix (3DEEM) fluorescence spectroscopy was employed to investigate the structure and characteristics of humic acid (HA) from landfills at different stabilization processes. The results show that the HA in anaerobic landfill leachate stabilized more rapidly than that in semi-aerobic landfill leachate. There were strong interactions between HA and Hg, the S content as well as the oxygen-containing ligands of the HA played a key role in the complexation with mercury. The higher complexation capacity (CL) and stability constant (logK) of HA from anaerobic landfill leachate implies that it is important to strengthen the control of mercury transportation in anaerobic landfills during the early stabilization process. The logK and CL of HA from semi-aerobic landfill leachate increased with the landfill time indicate that control of leachate Hg contamination in the latter stage is of great significance in semi-aerobic landfills.

Effects of Aerobic Conditioning on Salivary IgA and Plasma IgA, IgG and IgM in Older Men and Women

As people age, they experience a decline in immune responses. Unusually heavy acute or chronic exercise could increase the risk of upper respiratory tract infection (URTI) whereas regular moderate physical activity may reduce URTI symptomatology. The purpose of the present study was to determine whether an aerobic exercise program would promote chronic adaptations in plasma IgA, IgG and IgM, and salivary IgA (Sal-IgA) in both elderly women and men. Forty-three independently living men and women, aged between 65 and 96 years, were randomly assigned to an aerobic exercising or a control group. Each participant underwent three evaluations (pre, post at 16 weeks and follow-up at 32 weeks). The aerobic exercise group increased resting plasma IgA concentration from 1.08 g. L (-1)+/-0.50 g. L (-1) to 2.29 g. L (-1)+/-0.93 g. L (-1), whereas salivary IgA concentration was unchanged. The control group maintained the plasma IgA values but experienced a decrease in Sal-IgA. The IgG and IgM plasma concentrations increased in both groups, however, only the exercise group maintained higher values in the final follow-up evaluation. Regular aerobic exercise may be effective in promoting IgA immunity and protecting against the deterioration in Sal-IgA values observed in the control group. No gender differences in the immunoglobulin responses to aerobic training were observed.

Aerotolerance of strictly anaerobic microorganisms and factors of defense against oxidative stress: A review

Effects of aerobic conditions on strictly anaerobic microorganisms belonging to diverse taxa (clostridia, acetogenic bacteria, lactic acid bacteria, bacteroids, sulfate-reducing bacteria, and methanogenic archaea) and differing considerably in their oxygen resistance have been reviewed, with emphasis on the role of aerotolerance in the ecology of anaerobes. Consideration is given to components of nutritive media for anaerobe culturing, which decrease the toxic effects of oxygen and there by contribute significantly to maintenance and storage of industrial cultures of strictly anaerobic microorganisms. Physiological and biochemical factors are described, accounting for the relative resistance of many strict anaerobes to oxygen and products of incomplete reduction thereof. Specific attention is given to regulation of enzymes of antioxidative defense, operating in the cells of strict anaerobes under the conditions of oxidative stress caused by oxygen, superoxide anion, or hydrogen peroxide.

Effects of Aerobic Conditioning and Strength Training on a Child with Down Syndrome: A Case Study

To determine the effects of a home exercise program of combined aerobic and strength training on fitness with a 10.5-year-old girl with Down syndrome (DS). Measurements included cardiovascular variables, strength, body composition, flexibility, and skill. The subject participated in a home exercise program: 30 to 60 minutes of moderate- to high-intensity exercise five to six days per week for six weeks. The cardiovascular variables monitored were heart rate, respiration rate, and oxygen consumption during a submaximal treadmill stress test. Other measures included 10-repetition maximal strength of selected muscle groups, body mass index, flexibility, Gross Motor Scales of the Bruininks-Oseretsky Test of Motor Proficiency, and anaerobic muscle power. Improvements in submaximal heart and respiration rates, aerobic performance, muscle strength and endurance, gross motor skills, and anaerobic power were observed for this subject. Body weight and flexibility were unchanged. For this subject, a combined aerobic and strength-training program resulted in improved cardiopulmonary functions not observed in previous studies of subjects with DS.

Effects of aerobic conditions in the rhizosphere of rice on the dynamics and availability of phosphorus in a flooded soil – A model experiment

AbstractThe secretion of O2 by rice roots results in aerobic conditions in the rhizoshere compared to the bulk flooded soil. The effect of this phenomenon on the adsorption/desorption behavior and on the availability of phosphorus (P) in a flooded soil was investigated in a model experiment. An experimental set‐up was developed that imitates both O2 release and P uptake by the rice root. The results showed that O2 secretion significantly reduced P adsorption/retention and increased P desorption/release in the “rhizosphere” soil, compared to the anaerobic bulk soil. The P uptake by an anion exchange resin from both unfertilized and P‐amended soil was significantly increased.The results confirm that the O2 secretion is an important mechanism to enhance P availability and P uptake of rice under flooded conditions, where the “physico‐chemical” availability of P in the anaerobic bulk soil is strongly reduced. The decrease of P availability in the P‐amended flooded bulk soil was mainly associated with the almost complete transformation of the precedingly enriched Al‐P fraction into Fe‐bound P with extremely low desorption/release characteristics during the subsequent flooding.

In vitro alterations in fecal short chain fatty acids and organic anions induced by the destruction of intestinal microflora under hypotonic and aerobic conditions

The pathogenesis of inflammatory bowel disease (IBD) remains unknown. It has been suggested that luminal factors such as the microflora, short chain fatty acids (SCFAs), food antigens and so on play important roles in the disease progression. Many reports have revealed alterations in the SCFA and organic acid concentration of the colon, especially increased lactate and decreased butyrate, in IBD patients. The mechanisms responsible for these alterations, however, remain unclear. Therefore, the effects of aerobic conditions on the alterations in the SCFA and organic anion levels in the feces was evaluated. Fecal specimens were collected from 5 healthy volunteers. Under aerobic condition, a mixture of feces and distilled water was incubated in 37 degrees C for 1 and 3 h. The pH, osmotic pressures, the concentrations of potassium, bicarbonate, SCFA and organic anion, and the activities of alpha-amylase and lactate dehydrogenase (LDH) in the mixture were then measured. We also examined any changes in the microscopic microflora under the hypotonic and aerobic conditions. The results showed the osmotic pressure, and the concentrations of lactate and SCFAs (formate, acetate, propionate and n-valerate) were progressively increased with longer incubation times, and reached a statistically significant difference. In particular, the ratios of lactate, succinate and n-valerate after 1 and 3 h of incubation increased remarkably. In contrast, the electrolyte levels and both alpha-amylase and LDH activities were not altered significantly. Microscopically, the microflora in the mixture decreased with prolonged incubation times. These data suggest that under these in vitro conditions, the organic anion and SCFA levels in the feces easily increased. It is probable that the alterations in the SCFA and organic anion levels in IBD patients may be partly due to intracellular components derived from microflora destroyed under hypotonic and aerobic conditions in the colonic lumen, for example caused by mucosal bleeding. These alterations may influence the pathogenesis and progression of IBD.

The Physical Activity Scale for the Elderly (PASE): Evidence for Validity

We assessed the validity of the Physical Activity Scale for the Elderly (PASE) in a sample of sedentary adults (56 men, 134 women, mean age ± [SD] 66.5 ± 5.3 years) who volunteered to participate in a randomized controlled trial on the effect of aerobic conditioning on psychological function. Construct validity was established by correlating PASE scores with physiologic and performance characteristics: peak oxygen uptake, resting heart rate and blood pressure, percent body fat, and balance. The mean PASE scores were higher in men than in women (men = 145.8 ± 78.0; women = 123.9 ± 66.3, P < 0.05), and in those age 55–64 years compared with those age 65 years and over (55–64 = 144.2 ± 75.8; 65 and over = 118.9 ± 63.9, P < 0.05). PASE scores were also significantly higher in those who did not report a chronic health condition (cardiovascular disease, hypertension, cancer, or recent surgery). PASE scores were significantly associated (P < 0.05) with peak oxygen uptake ( r = 0.20), systolic blood pressure ( r = −0.18) and balance score ( r = 0.20). No significant associations of PASE score and diastolic blood pressure, resting heart rate, or percent body fat were noted. These results provide additional evidence for the validity of the PASE as a measure of physical activity suitable for use in epidemiology studies on the association of physical activity, health, and physical function in older individuals.

Exercise conditioning in older coronary patients. Submaximal lactate response and endurance capacity.

Older coronary patients are at high risk of cardiac disability. Exercise conditioning programs have been demonstrated to improve functional capacity, particularly in younger coronary patients. In this study, the effects of aerobic conditioning on submaximal and maximal indicators of exercise performance were examined in 45 older coronary patients. Forty-five patients (mean age, 69 +/- 6 years; range, 62 to 82 years) entered 3-month and 12-month (n = 11) endurance training programs. Training effects were assessed during an exhaustive submaximal exercise protocol with measurement of endurance time, serum lactate, perceived exertion, and expired ventilatory measures. Exhaustive endurance time increased by more than 40% (30 +/- 10 to 41 +/- 10 minutes), with associated decreases in serum lactate, perceived exertion, minute ventilation, heart rate, and systolic blood pressure during steady-state exercise. Respiratory exchange ratio during steady-state exercise, an indicator of substrate utilization, decreased, indicating a shift toward greater use of free fatty acids as a metabolic fuel. In a subset of 10 patients, percent body fat was decreased (32 +/- 8% to 29 +/- 10%) over a period of 3 months. Older coronary patients respond to aerobic conditioning with remarkable improvements in submaximal endurance capacity, out of proportion to the more modest increases in VO2max. Activities that were exhaustive before training became sustainable for extended periods of time at a lower perceived exertion. Measurements of serum lactate, respiratory exchange ratio, and ventilation during steady-state exercise document that at an identical absolute work load after conditioning, exercise is performed using aerobic substrate to a greater degree, and ventilatory response to a given work load is lessened.

A comparison of modified atmosphere and vacuum skin packing for the storage of red meats

SummaryThe performances of two commercially available packaging systems for prolonging the shelf‐life of fresh meat were compared at 1°C and during simulated retail display. Beef and pork loin steaks in modified atmosphere packs (MAP), containing 75% O2 and 25% CO2, developed an initial bright red (beef) or pink (pork) colour, which gradually changed to brownish‐red or ‐pink after 12 days; similar samples in vacuum skin packs (VSP) remained purple‐red throughout the storage period. Off‐odours developed more rapidly in MAP (8–12 days), possibly due to more extensive growth of Brochothrix thermosphacta and the effects of aerobic conditions on the metabolites of lactic acid bacteria, which predominated in both types of packs. Evidence of rancidity, using thiobarbituric acid assay, was demonstrated in MAP beef after approximately 8 days, but not in VSP. Drip losses in MAP increased after 6 days' storage, but remained generally low in VSP. Physical texture (shear force values of cooked samples) of beef was unaffected by packaging method, but pork in VSP was significantly more tender (P &lt; 0.001) than in MAP.

The effect of aerobic conditioning on venous pooling in the foot

Nineteen fit college-age men were studied using foot (mid-arch) mercury-in-silastic strain gauge plethysmography before and after an 8-wk aerobic conditioning (running) program. Foot volume changes were followed through two maneuvers: a 15-s Trendelenburg procedure (passive leg elevation with subsequent relaxation in the dependent position) and a 15-s dynamic dorsi-flexion/plantar flexion exercise and subsequent relaxation. The conditioning regimen consisted of running 40 min, 3 d.wk-1 and resulted in a 10% (P less than 0.01) increase in VO2max. Following this regimen, subjects exhibited an increased blood volume drainage during the Trendelenburg procedure (mean delta VT = 3.3 ml.100 ml-1 pre-training, 3.8 ml.100 ml-1 post-training, P less than 0.05), but no significant change in delta VE (2.7 ml.100 ml-1 for all subjects). Muscle pump efficacy, defined as the ratio between delta VE and delta VT, did not change (64%). These data suggest that increased aerobic power via weight-bearing exercise training results in an increased foot venous pooling, but does not affect relative muscle pump function. This apparent increase in vascular pooling may be a physical response to the hypervolemia induced by endurance training, aiding in maintaining the constancy of vascular pressures.

The effects of aerobic conditioning and/or caloric restriction in overweight men and women

The purpose of this study was to compare the effects of exercise and/or caloric restriction for 12 wk on body composition, maximal aerobic power (VO2max), and serum lipids and lipoproteins in overweight individuals. Forty-eight males and 48 females (means age = 36.6 yr), 120-140% of ideal body weight, were randomly assigned to groups (N = 12 each) of diet-exercise (DE), diet (D), exercise (E), and sedentary control (C). The dietary regimen consisted of 1,200 kcal X d-1, while exercise consisted of 5 d X wk-1 of 30 min of walk/running. For the males, body weight (BW) and fat weight loss in the DE group (-11.8 and 23%, respectively) were significantly greater than in the D group (-9.1 and -18%), with both groups significantly greater than for E and C. In the females, BW and fat weight loss for DE (-10.4 and -24%) were significantly greater than for D (-7.8 and -20%), with both groups significantly greater than E and C. Both DE and D males and females had a decrease in fat-free weight of -4.5 and -2.4%, respectively. In both sexes, the increase in VO2max-BW (ml X kg -1 X min-1) in DE (25%) was significantly greater than for E (15%), D (11%), and C (0%), with differences between E and D nonsignificant. However, increases in absolute VO2max (1 X min-1) and VO2max-fat-free weight (ml X kg-1 X min-1) were similar (P greater than 0.05) for DE and E (14%) but significantly greater compared to D and C (2%).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of aerobic conditioning on the peripheral circulation during chronic beta-adrenergic blockade

The relation of peripheral circulatory adjustments to exercise training during long-term beta-adrenergic blockade has not been investigated. In 12 healthy men aged 22 to 34 years, blood flow in the calf was evaluated with submaximal exercise before and after a 6 week aerobic conditioning program. During conditioning, six subjects received no drug and six received propranolol, 80 to 120 mg/day in divided doses. Treated and control subjects were studied on entry and at the conclusion of a conditioning program, 72 hours after drug withdrawal in subjects given propranolol. The training was intensive and equivalent in both groups. Control subjects increased maximal oxygen uptake from 47.5 +/- 1.1 to 51.4 +/- 0.4 ml/kg per min (p less than 0.05), whereas those on propranolol did not improve. Immediately after exercise, blood flow in the calf was measured with strain gauge plethysmography after 3 minutes of supine exertion on a cycle ergometer. In control subjects, flow decreased from 15.7 +/- 1.6 to 14.0 +/- 1.4 ml/100 ml per min at 300 kg-m/min of exertion (p less than 0.05) and from 26.5 +/- 3.8 to 21.8 +/- 2.3 ml/100 ml per min at 700 kg-m/min (p less than 0.05). Vascular resistance was unchanged in these subjects at 300 kg-m/min (6.1 +/- 0.8 to 6.7 +/- 1.0 pru) (p = NS), but increased at 700 kg-m/min (4.2 +/- 0.8 to 4.8 +/- 0.7 pru) (p less than 0.05). In subjects given propranolol, no change in flow or resistance occurred after training at either work load.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of aerobic conditioning upon mood in clinically depressed men and women: a preliminary investigation.

A single-subject reversal design was used to test the hypothesis that aerobic conditioning would elevate mood in seven clinically depressed persons. The hypothesis was confirmed for two subjects but not for the group as a whole. A reversal design does not appear suitable for this area of investigation.

Oxidative phosphorylation and effects of aerobic conditions on Rhodopseudomonas viridis

Particles prepared from photosynthetically grown Rhodopseudomonas viridis, which has previously been described as an obligate photo-organotroph, catalyse oxidative phosphorylation. The P:O ratio is 0.3 with succinate as substrate and 0.45 with NADH. The reaction is inhibited by carbonyl cyanide p-trifluoromethoxyphenylhydrazone and oligomycin. Antimycin A or 2-heptyl-4-hydroxyquinoline- N-oxide inhibit succinate or NADH oxidation as well as oxidative phosphorylation. After repeated transfers of cultures from agar plates, kept aerobic in the dark, cells of R. viridis were capable of limited exponential aerobic growth. In such cells no bacteriochlorophyll and very little carotenoid was detected; there was also a loss of the characteristic membrane structure found in photosynthetic cells. The K m for oxygen of these cells was lowered from 0.35 (±0.09) to 0.007 (±0.002) mM and an additional cytochrome-like pigment was observed, with an absorption maximum at 560 nm at 77 °K. There was also an increased amount of a CO-binding pigment in aerobically grown cells.