Sequencing batch reactor (SBR) systems were used for the development of a system and operating procedures for the high production of polyhydroxyalkanoates (PHAs) by wastewater treatment (activated sludge) bacterial cultures. It was found that unbalanced growth conditions stimulated massive PHA production in activated sludge biomass. Operating conditions had a significant effect on PHA production and the composition of the accumulated copolymer when either laboratory prepared mixtures of organics or a high acetic acid industrial wastewater were used as the organic substrate mixture. Fully aerobic (AE) conditions with nitrogen (N) and phosphorus (P) limitations were the optimum conditions for PHA production when the laboratory prepared mixtures of orgnics were used, while fully AE with the combinations of N, P, and potassium (K) limitations were better for PHA production using a high acetic acid industrial wastewater as the substrate. One nutrient limitation or partial limitation of either N or P as used for commercial production using pure cultures did not promote massive PHA production in activated sludge biomass compared to the combination of nutrient limitations. A maximum cellular PHA accumulation of 70%TSS was obtained under fully AE conditions with multiple alternating periods of growth and N&P limitations. Microaerophilic/aerobic (MAA/AE) or anaerobic/aerobic (AN/AE) cycling promoted less PHA production compared to fully AE conditions. The relative amounts of the PHA copolymers formed, i.e., polyhydroxybutyrate (PHB) and polyhydroxyvalerate (PHV) were different under different operating conditions, even though the types and amounts of volatile fatty acids (VFAs) in the feed were the same. It was determined that high total phosphorus (TP) content inside the bacterial cells had a significant detrimental impact on PHA production by activated sludge biomass. A two-stage bioprocess was a better approach for obtaining activated sludge PHA accumulation because a growth phase was necessary to grow the bacterial population that contains minimal TP before starting the subsequent PHA accumulation phase. Seeding sludge obtained from a conventional fully aerobic wastewater treatment system was more suitable than seed obtained from a biological phosphorus removal (BPR) system because bacterial populations from BPR systems tended to convert organic substrates to intracellular carbohydrate content rather than PHA under nutrient limitation conditions. The molecular weights and melting point temperatures of PHAs produced by the mixed culture of activated sludge biomass were comparable to those obtained from pure cultures and have the potential to be used for commercial applications. The results of this study indicate that activated sludge biomass has considerable potential for PHA production for commercial purposes, and likely could do so utilizing wastewater sources of organics. In particular organic rich, nutrient limited wastewaters have potential for efficient PHA production. / Ph. D.

No description available.

No description available.

There have been many attempts at answering the question of whether the cardiovascular adaptations resulting from aerobic exercise training of a particular muscle group are transferable when exercise is performed with the untrained muscles? Through the use of power spectral analysis (PSA) of heart rate variability (HRV) and blood pressure variability (BPV) the present study investigated this question in terms of a training induced modification of neurocardiac control. Fifteen healthy subjects (7 arm trainers & 8 leg trainers) aerobically exercise trained for 9 weeks, 3 sessions/week for 45 minutes/session. Training workload intensities were selected individually to obtain a target training heart rate (HR) between 75-80% HR maximum as determined from the initial pre-training V0₂ₘₐₓ. of the respective limbs. The exercise training program had no effect on supine rest HR, HR V or BPV, or standing HR and HRV. Following training, the arm group demonstrated a significant increase in V0₂ₚₑₐₖ (30.0 ± 1.4 to 34.2 ± 1.8 ml/kg/min.; p<0.05) during arm exercise and a significant reduction in leg exercise V0₂ₚₑₐₖ ( 44.8 ± 2.1 to 41.2 ± 1.6 ml/kg/min.; p<0.05). The leg training group demonstrated a slight post-training increase in leg exercise V0₂ₚₑₐₖ (43.5 ± 1.7 to 44.2 ± 2.4 ml/kg/min.; N.S.) and no change in arm exercise V0₂ₚₑₐₖ. Post-training changes in the maximum power produced during the respective limb group exercise tests corresponded to those of V0₂ₚₑₐₖ results. Mean HR values obtained from the arm trained group during the progressive maximal arm exercise test demonstrated significant post-training reductions at 50 percent (Δ-13 ±3.0 b.p.m.;p<0.05) and 75 percent (Δ-16 ± 5.8 b.p.m.;p<0.05) of the pre-training maximum workload. No change in mean HR was observed during progressive leg exercise in the arm trained group. The leg training group demonstrated non-significant HR reductions in both arm (Δ-3 ± 3.1 b.p.m. at 50% & Δ-6 ± 2.8 b.p.m. at 75%; N.S.) and leg (Δ -6 ± 4.5 b.p.m. at 50% & Δ -9 ± 3.5 b.p.m. at 75%; N.S.) progressive exercise tests. Mean HR and indices of HRV and BPV measured over 15 minutes of recovery following maximal exercise of both limb groups, were unaffected as a result of either training modality. The leg trained group demonstrated non-significant reductions in mean HR during both arm and leg steady-state submaximal exercise tests following training. No significant changes in any HRV components were observed in concordance with these non-significant mean HR reductions. Similarly, the arm trained group failed to demonstrate any significant changes in mean HR or HRV indices during either arm or leg submaximal exercise. Results from the present investigation indicated that a positive exercise training effect had occurred in the arm trained group, while the leg training group demonstrated smaller improvements in exercise performance compared to the arm trainers. Findings from the incremental exercise test further demonstrated the post-training improvements in the arm training group, and negligible improvements within the leg trained group. These improvements, or lack of, were all demonstrated in the mean HR measure with no significant changes in HRV patterns. This would suggest that non-neural factors contributed to most of the post-training adaptations. The discrepancies in results between the two training groups may be attributed firstly to the arm muscles greater potential for peripheral adaptations. Secondly, an inadequate training stimulus for the leg training group probably resulted in their poor post-training improvements. Lastly, the low submaximal exercise test intensities may have limited a clear observation in training improvements of either limb training group. The examination of post-maximal arm and leg exercise recovery failed to disclose any new information on the neurocardiac influences during exercise recovery subsequent to upper or lower limb training. The question of whether training induced neurocardiac control modifications may be transferable between the trained and untrained limbs may still be relevant, but requires more vigorous training of either muscle group. / Thesis / Master of Science (MSc)

Metabolic fuel use in rainbow trout (𝘖𝘯𝘤𝘰𝘳𝘩𝘺𝘯𝘤𝘩𝘶𝘴 𝘮𝘺𝘬𝘪𝘴𝘴 W.) was investigated using closed system respirometry and proximate body analysis. During short term starvation (15 days, routine activity) the utilization of protein as a substrate, as determined by respirometry, increased from 14 to 24% of total fuel supply. However, even by the end of the experiment, the contribution of protein (24%) did not approach the classically reported values for fish of between 40 and 90%. Indeed, from respirometry data, during the first quarter of the experiment lipid contributed the majority of the fuel ( >60%) while carbohydrate contributed about 20%. Thereafter, lipid and carbohydrate became essentially equivalent in importance (about 37% each). However, from proximate body analysis, a more traditional fuel mixture was found (protein, 58%; lipid, 40%; carbohydrate, 2%) suggesting the possibility that the two procedures were measuring fundamentally different parameters. Instantaneous fuel use during sustainable swimming at different speeds was investigated by respirometry using three day test periods. While protein catabolism remained constant over time, and uniform between groups, its relative contribution tended to increase with time as total M₀₂ declined with sustained swimming. Protein catabolism was highest in nonswimming fish (30-45%) and lowest in the high speed swimmers (20%); lipid was the most abundant (41-55%) fuel used in all groups at all times. In the nonswimmers and lowspeed swimmers, lipid use tended to increase slightly over time whereas in the high speed swimmers, lipid use dropped from 54 to 44%. Carbohydrate use (up to 38%) was higher than predicted by earlier literature, but decreased greatly in both the nonswimmers and low speed swimmers over the three days, whereas in the high speed swimmers the contribution increased with time. The low speed swimmers from the last set of experiments were used as controls for the final set of experiments in which another group of fish were trained for two weeks at 1.0 L·s⁻¹ prior to testing using an otherwise similar regime. Even though there was no difference in gas exchange, the make-up of the fuel mixture was different for the two groups. Protein use was significantly lower, while lipid use was higher in the trained fish. In addition, relative protein use in the trained fish was constant over the three day period, a feature found only in the the high speed swimmers of the previous experiment. A critical evaluation of the respiratory quotient is given since its use by fish physiologists has been without complete conversion from that used by the mammal physiologists. In addition, the often quoted term "fuel use" is differentiated into 𝘪𝘯𝘴𝘵𝘢𝘯𝘵𝘢𝘯𝘦𝘰𝘶𝘴 𝘧𝘶𝘦𝘭 𝘶𝘴𝘦 and 𝘤𝘰𝘮𝘱𝘰𝘴𝘪𝘵𝘪𝘰𝘯𝘢𝘭 𝘧𝘶𝘦𝘭 𝘶𝘴𝘦 since the two describe fundamentally different principles, though this has not always been recognized in the literature. / Thesis / Master of Science (MS)

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The treatability of a high strength industrial wastewater, 9,000 mg/L as chemical oxygen demand (COD), by three sequencing batch reactor (SBRs) systems operated under alternating redox environments: anaerobic/aerobic (ANA), anoxic/aerobic (ANX), and aerobic was investigated. A synthetic wastewater was modeled after a wastewater from an existing chemical processing facility. The largest component, hydroxypivaldehyde, was unavailable for the use in this research and was substituted by pivalic acid, both of which have a tertiary carbon. No significant degradation occurred in the anaerobic phase of operation; however, 55-65% of the COD was removed during anoxic operation. Simultaneous removal of pivalic acid and acetic acid was seen in both the anoxic and aerobic reaction phases. The anoxic/aerobic SBR provided the best overall treatability of the synthetic wastewater based on: effluent quality, sludge characteristics and settling properties. The results suggested that anoxic/aerobic treatment schemes are a viable treatment alternative for industrial wastewaters containing high concentrations of organic acids, including acids with tertiary carbons. The treatability of the three alternating redox environments on the Industry's wastewater was also investigated. Again, no significant degradation of the industrial wastewater occurred during the anaerobic reaction phase. During the anoxic reaction phase, 15-20% of the COD was removed from the industrial wastewater in contrast to the high removals seen with the synthetic wastewater. The aerobic SBR provided the best COD removal for the industrial wastewater. The performance differences between the synthetic and industrial wastewaters stress the importance of treatability studies on the actual industrial wastewater. Biological treatment of the synthetic and Industry wastewaters was unable to achieve the effluent goal of 100 mg/L as COD. Sand filtration followed by granular activated carbon adsorption treatment of the effluent from the synthetic wastewater-fed ANA SBR provided the COD removal necessary to achieve the effluent goal. / Master of Science

No description available.

The purpose of this study was to investigate if a low mixed carbohydrate plus moderate protein supplement, provided during endurance exercise, would improve time to exhaustion in comparison to a traditional 6% carbohydrate supplement in female athletes exercising at or below their ventilatory threshold. Fourteen (n = 14) trained female cyclists and triathletes cycled on two separate occasions for three hours at intensities varying between 45% - 70% VO₂max, followed by a ride to exhaustion at an intensity approximating the individual's VT (average 75.06% VO₂max). Supplements (275ml) were provided every 20 min during exercise and were composed of a 3% carbohydrate mixture + 1.2% protein (CHO+PRO) or a 6% carbohydrate-only (CHO). The CHO+PRO treatment contained a mixture of dextrose, maltodextrin, fructose, and whey protein isolate. The CHO treatment was composed of dextrose only. Time to exhaustion (TTE) was significantly greater with CHO+PRO in comparison to CHO (49.94 ± 7.01 vs 42.36 ± 6.21 min, respectively, p < 0.05). Blood glucose was signifcantly lower during the CHO+PRO (4.07 ± 0.12 mmol x L⁻¹) trial compared to CHO (4.47 ± 0.12 mmol x L⁻¹), with treatment x time interactions occurring from 118 minutes of exercise until exhaustion (p < 0.05). Heart rate was significantly lowered in the CHO+PRO treatment during exercise as compared to CHO (p < 0.05). There were no significant differences for other blood measures, ratings of perceived exertion or carbohydrate and fat oxidation between trials. Results from the present study suggest that the addition of a moderate amount of protein to a low mixed carbohydrate supplement improves endurance performance in females above that of a traditional 6% carbohydrate supplement. Improvement in performance occurred despite CHO+PRO containing a lower carbohydrate and caloric content. It is likely the greater performance seen with CHO+PRO was a result of the carbohydrate protein combination and the use of a mixture of carbohydrate sources. / text

The largest percentage of mortality from tobacco smoking is cardiovascular-related. It is not known whether regular participation in exercise mitigates the adverse influence of smoking on vasculature. The purpose of this study is to determine if regular aerobic exercise is associated with reduced arterial stiffness in young men who are cigarette smokers. Using a cross-sectional observational study design, the sample included 78 young men (22±5 years) with the following classification: sedentary smokers (n=12); physically active smokers (n=25); sedentary non-smokers (n=20); and physically active non-smokers (n=21). Arterial stiffness was assessed by brachial-ankle pulse wave velocity (baPWV). There were no group differences in height, body fatness, systolic and diastolic blood pressure. As expected, both physically active groups demonstrated greater VO2max and lower heart rate at rest than their sedentary peers. The sedentary smokers demonstrated greater baPWV than the sedentary non-smokers (1,183±33.5 vs. 1,055±25 cm/sec). baPWV was not different between the physically-active smokers and the physically-active non-smokers (1,084±26 vs. 1,070±28.6 cm/sec). Chronic smoking is associated with arterial stiffening in sedentary men but a significant smoking-induced increase in arterial stiffness was not observed in physically active adults. These results are consistent with the idea that regular participation in physical activity may mitigate the adverse effect of smoking on the vasculature. / text