Laboratory simulations of the City of Sydney’s stormwater biofilter units to assess the impact of design, fill variation and substrate amendment on pollution removal efficiency

In 2013, Western Sydney University (WSU) formed a research partnership with the City of Sydney Council (City) to investigate the performance of street stormwater biofilters (raingardens) mainly in the Southern Sydney area. The City was in the process of constructing 21,000 square metres of bioretention systems as part of their Decentralised Water Master Plan for improving the quality of stormwater runoff to Port Jackson, the Cooks River and the historical Botany Bay. The City’s program provided an excellent example for exploring urban stormwater biofiltration systems. The thesis reports on the completed laboratory component of the investigation, with the field component being ongoing. The laboratory component was intended to inform the design, potential performance and maintenance of field biofilters, and to establish a transferable simulation technology. In the laboratory biofilter simulations, synthetic stormwater was fed to 104 mm diameter soil columns with the same vertical cross-sections and fill material as the street units. Sufficient time was allowed for the development of biochemical processes, and removal results were compared with relevant local pollution reduction targets. A 104 mm column diameter minimised the edge effect associated with narrower columns, while containing the cost and spatial footprint of the equipment to facilitate technology transfer. The study concluded that simplified, low-footprint soil column simulations of decentralised water treatment devices, such as street stormwater biofilters, can be successfully applied to improvements in design, performance and maintenance cycles, with potential for the same simulation equipment to be used for performance-testing of commercial fills, avoiding subsequent costly remediation operations for field units. Overall, the study contributed materially to biofilter design and operation for purifying street stormwater runoff to promote safe and sustainable water recycling and secure high-quality environmental flows, with implications for technology transfer and hence contribution to global water security

Can We Calculate Mean Arterial Pressure in Humans?

Mean arterial pressure (MAP) is either measured with an oscillometric cuff and then systolic (SBP) and diastolic (DBP) blood pressures are estimated from an unknown algorithm; or SBP and DBP are measured via auscultation and MAP calculated using measures of systolic pressure (SBP), diastolic pressure (DBP), and a form-factor (FF; equation: [(SBP-DBP)*FF]+DBP). The typical FF used is 0.33 though others (0.4) have been proposed. Recent work indicates that estimation of aortic MAP via a FF leads to inaccurate values and should therefore be interpreted with caution, whether this is the case for local MAP is unknown. While the implications for hypertension (HTN) diagnosis are minimal, the calculation of local MAP is essential to the study of blood pressure regulation and exercise hemodynamics in patient populations (e.g. heart failure). PURPOSE: To compare the calculation of local MAP using catheter waveforms and a FF, against MAP derived from the pressure-time integral (PTI; i.e. average pressure across the cardiac cycle) measured via radial arterial catheterization. METHODS: We analyzed radial arterial catheter waveforms from 39 patients (Age: 71±7 years; BMI: 38.4±6.7; Female: 66%; HTN prevalence: 97%) with heart failure with preserved ejection fraction (HFpEF) at rest and during cycling exercise at 20 Watts. We compared the PTI (from the catheter waveform) with the calculation of MAP from the peak and nadir of the same waveforms (5-beat averages) using the 0.33 and 0.4 FF’s in the FF equation. RESULTS: Compared to the PTI (91±13 mmHg), resting MAP was not significantly different when calculated using the 0.33 FF (91±11 mmHg, P\u3e0.999) but was higher when using the 0.4 FF (96±12 mmHg, PCONCLUSION:While the 0.33 FF provides an accurate assessment of MAP on average during rest and exercise in the radial artery in patients with HFpEF, the limits of agreement are large reflecting a lack of precision in measurement at an individual level. Indirect calculations of MAP via a FF may lead to inaccurate conclusions regarding the mechanisms of blood pressure regulation both at rest and during exercise testing in this population

Synchronizing Cardiac Cycle Phase with Foot Strike to Optimize Cardiac Performance in Patients with Chronic Systolic Heart Failure and Cardiac Resynchronization Therapy (CRT)

Despite advances in medical and Cardiac Resynchronization Therapy (CRT), patients with chronic systolic heart failure (HF) have persistent symptoms including dyspnea on exertion and exercise intolerance. Novel strategies to improve exercise performance in these patients, such as optimizing cardio-locomotor coupling, could be particularly beneficial to improve functional capacity. For example, runners display a lower heart rate and higher oxygen pulse, suggestive of a higher stroke volume (SV), when foot strike occurs in diastole. Whether patients with HF undergoing CRT can similarly increase SV is unknown. PURPOSE: To compare the effects of diastolic versus systolic foot strike timing on exercise hemodynamics in patients with HF and CRT. METHODS: Ten patients (Age: 58 ± 17 years, 40% Female) with HF and previously implanted CRT pacemakers completed repeated 5-minute bouts of walking on a treadmill at a fixed but individualized speed (range: 1.5-3mph). Participants were randomized to walking to an auditory tone to synchronize their foot strike to either the systolic (ECG R-wave; 0 or 100%±15% or R-R interval) or diastolic phase (45±15% of the R-R interval) of their cardiac cycle. Participants were included if ≥50% of their steps were valid (i.e. in time). Patients wore a chest strap with an attached ECG sensor and accelerometer (CounterpaceR). Foot strike timing and associated valid step counts were assessed via CounterpaceR or post-hoc analysis of foot strike waveforms. Cardiopulmonary parameters were measured breath by breath via indirect calorimetry and cardiac output was measured via acetylene rebreathing, with SV calculated as the quotient of cardiac output and heart rate. RESULTS: There was no difference in oxygen uptake between conditions (1.02 ± 0.44 vs. 1.04 ± 0.44 L/min, P=0.298). When compared to systolic walking, stepping in diastole was associated with higher SV (Diastolic: 80 ± 28 vs. Systolic: 74 ± 26 ml, P=0.003) and cardiac output (8.3 ± 3.5 vs. 7.9 ± 3.4 L/min, P=0.004); heart rate (paced) was not different between conditions (101 ± 15 vs. 103 ± 14 bpm, P=0.300). Mean arterial pressure was significantly lower during diastolic walking (85 ± 12 vs. 98 ± 20 mmHg, P=0.007). CONCLUSION: In patients with HF and previous CRT, synchronizing foot strike with diastole during walking increased SV and cardiac output and reduced arterial pressure. Our findings indicate that in such paced hearts, diastolic stepping increases oxygen delivery and decreases afterload, which may facilitate increased exercise capacity. Therefore, if added to pacemakers, this cardio-locomotor coupling technology may maximize CRT efficiency and increase exercise participation and quality of life in patients with HF

Cardiac mechanisms for low aerobic power in anthracycline treated, older, long-term breast cancer survivors

Breast cancer survivors have reduced peak aerobic capacity (VO2peak) which may be related to latent or lingering chemotherapy induced cardiac damage. Nine, older (67 ± 3 years), long-term survivors (9.8 years) of anthracycline based chemotherapy and age- and sex-matched healthy controls were recruited and tested to determine whether: i) VO2peak remains reduced in long-term survivorship; and ii) reductions in VO2peak are due to cardiac dysfunction. VO2peak was significantly reduced in breast cancer survivors relative to healthy controls (15.9 ± 2.0 vs 19.9 ± 3.1 ml/kg/min, p = 0.006), however the heart rate and stroke volume responses to exercise were normal (heart rate reserve; 88 ± 9 vs 85 ± 10 bpm, p = 0.62: stroke volume reserve; 13 ± 6 vs 13 ± 9 ml,p = 0.94). These findings indicate low-normal ventricular size in long-term breast cancer survivors, but normal reserve function

Genetic and environmental determinants of diastolic heart function

Diastole is the sequence of physiological events that occur in the heart during ventricular filling and principally depends on myocardial relaxation and chamber stiffness. Abnormal diastolic function is related to many cardiovascular disease processes and is predictive of health outcomes, but its genetic architecture is largely unknown. Here, we use machine learning cardiac motion analysis to measure diastolic functional traits in 39,559 participants of the UK Biobank and perform a genome-wide association study. We identified 9 significant, independent loci near genes that are associated with maintaining sarcomeric function under biomechanical stress and genes implicated in the development of cardiomyopathy. Age, sex and diabetes were independent predictors of diastolic function and we found a causal relationship between genetically-determined ventricular stiffness and incident heart failure. Our results provide insights into the genetic and environmental factors influencing diastolic function that are relevant for identifying causal relationships and potential tractable targets

A critical examination of the health promoting prison two decades on

Two decades since the WHO Regional Office for Europe outlined and published a report on health promotion in prison, which stimulated further debate on the concept of the ‘health promoting prison’, this paper discusses the extent to which the concept has translated into practice and the extent to which success has been achieved. This paper primarily focuses on why there has been a gap between the strategic philosophy of health promotion in prison and practical implementation, suggesting that factors such as ‘lifestyle drift’ and public and political opinion have played a part. A further argument is made in relation to the overall commitment of European countries and more broadly WHO in their support of settings-based health promotion in this context. It is proposed that there has been a weakening of commitment over time with a worrying ‘negative trajectory’ of support for health promoting prisons. The paper argues that despite these challenges, the opportunities and potential to address the needs of those who are often most vulnerable and excluded is colossal and acting to tackle this should be a greater priority

A Developmental Approach to Machine Learning?

Visual learning depends on both the algorithms and the training material. This essay considers the natural statistics of infant- and toddler-egocentric vision. These natural training sets for human visual object recognition are very different from the training data fed into machine vision systems. Rather than equal experiences with all kinds of things, toddlers experience extremely skewed distributions with many repeated occurrences of a very few things. And though highly variable when considered as a whole, individual views of things are experienced in a specific order – with slow, smooth visual changes moment-to-moment, and developmentally ordered transitions in scene content. We propose that the skewed, ordered, biased visual experiences of infants and toddlers are the training data that allow human learners to develop a way to recognize everything, both the pervasively present entities and the rarely encountered ones. The joint consideration of real-world statistics for learning by researchers of human and machine learning seems likely to bring advances in both disciplines

Genetic and environmental determinants of diastolic heart function

Diastole is the sequence of physiological events that occur in the heart during ventricular filling and principally depends on myocardial relaxation and chamber stiffness. Abnormal diastolic function is related to many cardiovascular disease processes and is predictive of health outcomes, but its genetic architecture is largely unknown. Here, we use machine learning cardiac motion analysis to measure diastolic functional traits in 39,559 participants of the UK Biobank and perform a genome-wide association study. We identified 9 significant, independent loci near genes that are associated with maintaining sarcomeric function under biomechanical stress and genes implicated in the development of cardiomyopathy. Age, sex and diabetes were independent predictors of diastolic function and we found a causal relationship between genetically-determined ventricular stiffness and incident heart failure. Our results provide insights into the genetic and environmental factors influencing diastolic function that are relevant for identifying causal relationships and potential tractable targets

Resounding meaning: a PERMA wellbeing profile of classical musicians

While music has been linked with enhanced wellbeing across a wide variety of contexts, the professional pursuit of a music career is frequently associated with poor psychological health. Most research has focused on assessing negative functioning, and to date, few studies have attempted to profile musicians’ wellbeing using a positive framework. This study aimed to generate a profile that represents indicators of optimal functioning among classical musicians. The PERMA model, which reconciles hedonic and eudaimonic wellbeing, was adopted and its five elements assessed with a sample of professional classical musicians: Positive Emotion, Engagement, Relationships, Meaning and Accomplishment. 601 participants (298 women, 303 men) engaged in careers as orchestral (n = 236), solo (n = 158), chamber (n = 112), and choral musicians (n = 36), as well as composers (n = 30) and conductors (n = 29), answered the PERMA-Profiler, a self-report questionnaire built to assess the five components of PERMA. Results point to high scores across all dimensions, with Meaning emerging as the highest rated dimension. Musicians scored significantly higher than general population indicators on Positive Emotion, Relationships and Meaning. When wellbeing is assessed as positive functioning and not the absence of illbeing, musicians show promising profiles. The reconciliation between these findings and the previous body of research pointing to the music profession as highly challenging for healthy psychological functioning is discussed. *** For a video summary of this article please see http://researchonline.rcm.ac.uk/id/eprint/1804/ **