The appraisal of mesophilic anaerobic digestion and thermophilic aerobic digestion in the treatment of municipal sludge in Ireland

It has been well documented that the optimum feedstock for anaerobic digesters consists of readily biodegradable compounds, as found in primary sludge or even a mixed substrate of primary and excess activated sludge. Due to the requirements of the Urban Wastewater Treatment Plant Directive of 1991, the quantities of secondary sludge generated is set to increase substantially. A pilot scale study was undertaken to evaluate the performance of both Mesophilic Anaerobic Digestion and Thermophilic Aerobic digestion in the treatment of secondary sludge. The results indicated that the anaerobic pilot scale digester achieved a greater solids destruction than the aerobic pilot plant averaging at 28% T.S. removal verses 20% for the aerobic digester, despite the fact that secondary sludge is the optimum feedstock for aerobic digestion. This can, however, be attributed to the greater biomass yield experienced with aerobic systems, and to the absence of Autothermal conditions. At present, the traditional technique of Mesophilic Anaerobic Digestion is in widespread application throughout Ireland, for the stabilisation of sewage sludge. There is only one Autothermal Thermophilic Aerobic Digester at present situated in Killarney, Co. Kerry. A further objectives of the study was to compare full-scale applications of Mesophilic Anaerobic Digestion to ATAD. Two Sludge Treatment plants, situated in Co. Kerry, were used for this purpose, and were assessed mainly under the following headings; process stability, solids reduction on average, the ATAD plant in Killarney has the advantage of producing a “Class A” Biosolid in terms of pathogen reduction, and can effectively treat double the quantity of sludge. In addition, economically the ATAD plant is cheaper to run, costing €190 / t.d.s verses €211 / t.d.s. for the anaerobic digester in Tralee. An overview of additional operational Anaerobic Digestion Plants throughout Ireland is also presented.

Heart Rate Variability Correlates to Functional Aerobic Impairment in Hemodialysis Patients

Background:Autonomic dysfunction (AD) is highly prevalent in hemodialysis (HD) patients and has been implicated in their increased risk of cardiovascular mortality.Objective:To correlate heart rate variability (HRV) during exercise treadmill test (ETT) with the values obtained when measuring functional aerobic impairment (FAI) in HD patients and controls.Methods:Cross-sectional study involving HD patients and a control group. Clinical examination, blood sampling, transthoracic echocardiogram, 24-hour Holter, and ETT were performed. A symptom-limited ramp treadmill protocol with active recovery was employed. Heart rate variability was evaluated in time domain at exercise and recovery periods.Results:Forty-one HD patients and 41 controls concluded the study. HD patients had higher FAI and lower HRV than controls (p<0.001 for both). A correlation was found between exercise HRV (SDNN) and FAI in both groups. This association was independent of age, sex, smoking, body mass index, diabetes, and clonidine or beta-blocker use, but not of hemoglobin levels.Conclusion:No association was found between FAI and HRV on 24-hour Holter or at the recovery period of ETT. Of note, exercise HRV was inversely correlated with FAI in HD patients and controls. (Arq Bras Cardiol. 2015; [online]. ahead print, PP.0-0)

Alternatives to Aerobic Exercise Prescription in Patients with Chronic Heart Failure

Background: Exercise is essential for patients with heart failure as it leads to a reduction in morbidity and mortality as well as improved functional capacity and oxygen uptake (v̇O2). However, the need for an experienced physiologist and the cost of the exam may render the cardiopulmonary exercise test (CPET) unfeasible. Thus, the six-minute walk test (6MWT) and step test (ST) may be alternatives for exercise prescription. Objective: The aim was to correlate heart rate (HR) during the 6MWT and ST with HR at the anaerobic threshold (HRAT) and peak HR (HRP) obtained on the CPET. Methods: Eighty-three patients (58 ± 11 years) with heart failure (NYHA class II) were included and all subjects had optimized medication for at least 3 months. Evaluations involved CPET (v̇O2, HRAT, HRP), 6MWT (HR6MWT) and ST (HRST). Results: The participants exhibited severe ventricular dysfunction (ejection fraction: 31 ± 7%) and low peak v̇O2 (15.2 ± 3.1 mL.kg-1.min-1). HRP (113 ± 19 bpm) was higher than HRAT (92 ± 14 bpm; p < 0.05) and HR6MWT (94 ± 13 bpm; p < 0.05). No significant difference was found between HRP and HRST. Moreover, a strong correlation was found between HRAT and HR6MWT (r = 0.81; p < 0.0001), and between HRP and HRST (r = 0.89; p < 0.0001). Conclusion: These findings suggest that, in the absence of CPET, exercise prescription can be performed by use of 6MWT and ST, based on HR6MWT and HRST

Aerobic Training after Myocardial Infarction: Remodeling Evaluated by Cardiac Magnetic Resonance

Abstract Background: Numerous studies show the benefits of exercise training after myocardial infarction (MI). Nevertheless, the effects on function and remodeling are still controversial. Objectives: To evaluate, in patients after (MI), the effects of aerobic exercise of moderate intensity on ventricular remodeling by cardiac magnetic resonance imaging (CMR). Methods: 26 male patients, 52.9 ± 7.9 years, after a first MI, were assigned to groups: trained group (TG), 18; and control group (CG), 8. The TG performed supervised aerobic exercise on treadmill twice a week, and unsupervised sessions on 2 additional days per week, for at least 3 months. Laboratory tests, anthropometric measurements, resting heart rate (HR), exercise test, and CMR were conducted at baseline and follow-up. Results: The TG showed a 10.8% reduction in fasting blood glucose (p = 0.01), and a 7.3-bpm reduction in resting HR in both sitting and supine positions (p < 0.0001). There was an increase in oxygen uptake only in the TG (35.4 ± 8.1 to 49.1 ± 9.6 mL/kg/min, p < 0.0001). There was a statistically significant decrease in the TG left ventricular mass (LVmass) (128.7 ± 38.9 to 117.2 ± 27.2 g, p = 0.0032). There were no statistically significant changes in the values of left ventricular end-diastolic volume (LVEDV) and ejection fraction in the groups. The LVmass/EDV ratio demonstrated a statistically significant positive remodeling in the TG (p = 0.015). Conclusions: Aerobic exercise of moderate intensity improved physical capacity and other cardiovascular variables. A positive remodeling was identified in the TG, where a left ventricular diastolic dimension increase was associated with LVmass reduction.

Control of fluidized bed spray granulation processes

Magdeburg, Univ., Fak. für Elektrotechnik und Informationstechnik, Diss., 2012

Model-based measurement and control of fluidised bed spray granulation processes

Magdeburg, Univ., Fak. für Verfahrens- und Systemtechnik, Diss., 2012

Relationship of physical activity with motor skills, aerobic fitness and body fat in preschool children: a cross-sectional and longitudinal study (Ballabeina).

Adiposity, low aerobic fitness and low levels of activity are all associated with clustered cardiovascular disease risk in children and their high prevalence represents a major public health concern. The aim of this study is to investigate the relationship of objectively measured physical activity (PA) with motor skills (agility and balance), aerobic fitness and %body fat in young children. This study is a cross-sectional and longitudinal analyses using mixed linear models. Longitudinal data were adjusted for baseline outcome parameters. In all, 217 healthy preschool children (age 4-6 years, 48% boys) participated in this study. PA (accelerometers), agility (obstacle course), dynamic balance (balance beam), aerobic fitness (20-m shuttle run) and %body fat (bioelectric impedance) at baseline and 9 months later. PA was positively associated with both motor skills and aerobic fitness at baseline as well as with their longitudinal changes. Specifically, only vigorous, but not total or moderate PA, was related to changes in aerobic fitness. Higher PA was associated with less %body fat at baseline, but not with its change. Conversely, baseline motor skills, aerobic fitness or %body fat were not related to changes in PA. In young children, baseline PA was associated with improvements in motor skills and in aerobic fitness, an important determinant of cardiovascular risk.

Endothelial Cell-Derived Nitric Oxide Enhances Aerobic Glycolysis in Astrocytes via HIF-1α-Mediated Target Gene Activation.

Astrocytes exhibit a prominent glycolytic activity, but whether such a metabolic profile is influenced by intercellular communication is unknown. Treatment of primary cultures of mouse cortical astrocytes with the nitric oxide (NO) donor DetaNONOate induced a time-dependent enhancement in the expression of genes encoding various glycolytic enzymes as well as transporters for glucose and lactate. Such an effect was shown to be dependent on the hypoxia-inducible factor HIF-1α, which is stabilized and translocated to the nucleus to exert its transcriptional regulation. NO action was dependent on both the PI3K/Akt/mTOR and MEK signaling pathways and required the activation of COX, but was independent of the soluble guanylate cyclase pathway. Furthermore, as a consequence of NO treatment, an enhanced lactate production and release by astrocytes was evidenced, which was prevented by downregulating HIF-1α. Several brain cell types represent possible sources of NO. It was found that endothelial cells, which express the endothelial NO synthase (eNOS) isoform, constitutively produced the largest amount of NO in culture. When astrocytes were cocultured with primary cultures of brain vascular endothelial cells, stabilization of HIF-1α and an enhancement in glucose transporter-1, hexokinase-2, and monocarboxylate transporter-4 expression as well as increased lactate production was found in astrocytes. This effect was inhibited by the NOS inhibitor l-NAME and was not seen when astrocytes were cocultured with primary cultures of cortical neurons. Our findings suggest that endothelial cell-derived NO participates to the maintenance of a high glycolytic activity in astrocytes mediated by astrocytic HIF-1α activation.

Relationship of aerobic fitness and motor skills with memory and attention in preschoolers (Ballabeina): a cross-sectional and longitudinal study.

BACKGROUND: The debate about a possible relationship between aerobic fitness and motor skills with cognitive development in children has recently re-emerged, because of the decrease in children's aerobic fitness and the concomitant pressure of schools to enhance cognitive performance. As the literature in young children is scarce, we examined the cross-sectional and longitudinal relationship of aerobic fitness and motor skills with spatial working memory and attention in preschool children. METHODS: Data from 245 ethnically diverse preschool children (mean age: 5.2 (0.6) years, girls: 49.4%) analyzed at baseline and 9 months later. Assessments included aerobic fitness (20 m shuttle run) and motor skills with agility (obstacle course) and dynamic balance (balance beam). Cognitive parameters included spatial working memory (IDS) and attention (KHV-VK). All analyses were adjusted for age, sex, BMI, migration status, parental education, native language and linguistic region. Longitudinal analyses were additionally adjusted for the respective baseline value. RESULTS: In the cross-sectional analysis, aerobic fitness was associated with better attention (r=0.16, p=0.03). A shorter time in the agility test was independently associated with a better performance both in working memory (r=-0.17, p=0.01) and in attention (r=-0.20, p=0.01). In the longitudinal analyses, baseline aerobic fitness was independently related to improvements in attention (r=0.16, p=0.03), while baseline dynamic balance was associated with improvements in working memory (r=0.15, p=0.04). CONCLUSIONS: In young children, higher baseline aerobic fitness and motor skills were related to a better spatial working memory and/or attention at baseline, and to some extent also to their future improvements over the following 9 months. TRIAL REGISTRATION: clinicaltrials.gov NCT00674544.

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.

Aerobic and functional capacities in a selected active population of European octogenarians

Master athletes are often considered to represent the ideal rate of decline of aerobic function; however, most of the studies interested in active elderly people are often limited to people younger than 75. We aimed to determine the physiological adaptations and aerobic fitness in a selected European population of active octogenarians during maximal and submaximal exercise tests. Aerobic capacity was measured during maximal incremental tests on treadmill (TR) and cycle-ergometer (CE) and functional capacity during a 6-minute walk test (6-MWT) in 17 subjects aged 81.2 +/- 0.8 years. Pulmonary gas exchange and heart rate (HR) were continuously measured during the different exercise tests. Maximal oxygen consumption (V.O (2max)) on TR and CE was significantly higher than predicted values (TR: 28.7 +/- 1.2 vs. 17 +/- 0.5 ml . kg (-1) . min (-1); CE: 23 +/- 1.2 vs. 16 +/- 0.6 ml . kg (-1) . min (-1) for measured and predicted values respectively). V.O (2max) and HR (max), as well as V.O (2) and HR at the ventilatory threshold (V.O (2)T (V.E) and HR T (V.E)) were significantly higher on TR than on CE (HR (max): 144 +/- 4 vs. 138 +/- 4 bpm; V.O (2)T (V.E): 22.5 +/- 0.8 vs. 17.7 +/- 0.9 ml . kg (-1) . min (-1) for TR and CE respectively). V.O (2)T (V.E) and HR T (V.E) on TR were equivalent to V.O (2) and HR measured during the 6-MWT. HR T (V.E) on TR and mean HR during the 6-MWT were strongly correlated (R = 0.82, p < 0.01). Maintenance of regular physical activity provides high aerobic fitness, in octogenarians, as was shown by the higher values of our subjects in comparison to predicted values. Moreover, the close relation between the intensity developed at T (V.E) on TR and 6-MWT could support the idea that a walk test is a submaximal test performed at high intensity that could provide a basis for exercise prescription in an individualized manner in active elderly people.

The peroxiredoxin Tpx1 is essential as a H202-scavenger during aerobic growth in fission yeast

Peroxiredoxins are known to interact with hydrogen peroxide (H2O2) and to participate in oxidant scavenging, redox signal transduction, and heat-shock responses. The two-cysteine peroxiredoxin Tpx1 of Schizosaccharomyces pombe has been characterized as the H2O2 sensor that transduces the redox signal to the transcription factor Pap1. Here, we show that Tpx1 is essential for aerobic, but not anaerobic, growth. We demonstrate that Tpx1 has an exquisite sensitivity for its substrate, which explains its participation in maintaining low steady-state levels of H2O2. We also show in vitro and in vivo that inactivation of Tpx1 by oxidation of its catalytic cysteine to a sulfinic acid is always preceded by a sulfinic acid form in a covalently linked dimer, which may be important for understanding the kinetics of Tpx1 inactivation. Furthermore, we provide evidence that a strain expressing Tpx1.C169S, lacking the resolving cysteine, can sustain aerobic growth, and we show that small reductants can modulate the activity of the mutant protein in vitro, probably by supplying a thiol group to substitute for cysteine 169.

Relationship of aerobic fitness and motor skills with memory and attention in preschoolers (Ballabeina): A cross-sectional and longitudinal study.

Background: The debate about a possible relationship between aerobic fitness and motor skills with cognitive development in children has recently re-emerged, because of the decrease in children's aerobic fitness and the concomitant pressure of schools to enhance cognitive performance. As the literature in young children is scarce, we examined the cross-sectional and longitudinal relationship of aerobic fitness and motor skills with spatial working memory and attention in preschool children.Methods: Data from 245 ethnically diverse preschool children (mean age: 5.2 (0.6) years, girls: 49.4%) analyzed at baseline and 9 months later. Assessments included aerobic fitness (20 m shuttle run) and motor skills with agility (obstacle course) and dynamic balance (balance beam). Cognitive parameters included spatial working memory (IDS) and attention (KHV-VK). All analyses were adjusted for age, sex, BMI, migration status, parental education, native language and linguistic region. Longitudinal analyses were additionally adjusted for the respective baseline value.Results: In the cross-sectional analysis, aerobic fitness was associated with better attention (r = 0.16, p = 0.03). A shorter time in the agility test was independently associated with a better performance both in working memory (r = -0.17, p = 0.01) and in attention (r = -0.20, p = 0.01). In the longitudinal analyses, baseline aerobic fitness was independently related to improvements in attention (r = 0.16, p = 0.03), while baseline dynamic balance was associated with improvements in working memory (r = 0.15, p = 0.04).Conclusions: In young children, higher baseline aerobic fitness and motor skills were related to a better spatial working memory and/or attention at baseline, and to some extent also to their future improvements over the following 9 months.

Effects of aerobic fitness on oxygen uptake kinetics in heavy intensity swimming.

This study aimed to characterise both the [Formula: see text] kinetics within constant heavy-intensity swimming exercise, and to assess the relationships between [Formula: see text] kinetics and other parameters of aerobic fitness, in well-trained swimmers. On separate days, 21 male swimmers completed: (1) an incremental swimming test to determine their maximal oxygen uptake [Formula: see text], first ventilatory threshold (VT), and the velocity associated with [Formula: see text] [Formula: see text] and (2) two square-wave transitions from rest to heavy-intensity exercise, to determine their [Formula: see text] kinetics. All the tests involved breath-by-breath analysis of freestyle swimming using a swimming snorkel. [Formula: see text] kinetics was modelled with two exponential functions. The mean values for the incremental test were 56.0 ± 6.0 ml min(-1) kg(-1), 1.45 ± 0.08 m s(-1); and 42.1 ± 5.7 ml min(-1) kg(-1) for [Formula: see text], [Formula: see text] and VT, respectively. For the square-wave transition, the time constant of the primary phase (τ(p)) averaged 17.3 ± 5.4 s and the relevant slow component (A'(sc)) averaged 4.8 ± 2.9 ml min(-1) kg(-1) [representing 8.9% of the end-exercise [Formula: see text] (%A'(sc))]. τ(p) was correlated with [Formula: see text] (r = -0.55, P = 0.01), but not with either [Formula: see text] (r = 0.05, ns) or VT (r = 0.14, ns). The %A'(sc) did not correlate with either [Formula: see text] (r = -0.14, ns) or [Formula: see text] (r = 0.06, ns), but was inversely related with VT (r = -0.61, P < 0.01). This study was the first to describe the [Formula: see text] kinetics in heavy-intensity swimming using specific swimming exercise and appropriate methods. As has been demonstrated in cycling, faster [Formula: see text] kinetics allow higher aerobic power outputs to be attained. The slow component seems to be reduced in swimmers with higher ventilatory thresholds.