Investigating the Sustainability of Outcomes in a Chronic Disease Treatment Programme

This study examines trends in chronic disease outcomes from initiation of a specialised chronic disease treatment programme through to incorporation of programme activities into routine service delivery. We reviewed clinical records of 98 participants with confirmed renal disease or hypertension in a remote indigenous community health centre in Northern Australia. For each participant the review period spanned an initial three years while participating in a specialised cardiovascular and renal disease treatment programme and a subsequent three years following withdrawal of the treatment programme. Responsibility for care was incorporated into the comprehensive primary care service which had been recently redeveloped to implement best practice care plans. The time series analysis included at least six measures prior to handover of the specialised programme and six following handover. Main outcome measures were trends in blood pressure (BP) control, and systolic and diastolic BP. We found an improvement in BP control in the first 6-12 months of the programme, followed by a steady declining trend. There was no significant difference in this trend between the pre- compared to the post-programme withdrawal period. This finding was consistent for control at levels below 130/80 and 140/90, and for trends in mean systolic and diastolic BP. Investigation of the sustainability of programme outcomes presents major challenges for research design. Sustained success in the management of chronic disease through primary care services requires better understanding of the causal mechanisms related to clinical intervention, the basis upon which they can be 'institutionalised' in a given context, and the extent to which they require regular revitalisation to maintain their effect

Modeling the vascular system with microfluidic technology

Here are presented several technologies advancing the state of microfluidic modeling of the vascular system through the integration of high throughput analysis equipment with microfluidic systems, allowing for the monitoring of cell-cell communication between the red blood cell (RBC) and endothelial cells. A review of the prior knowledge of the role of adenosine triphosphate (ATP) and nitric oxide (NO) release from the RBC is presented, along with the current understanding of the role these molecules play in vasodilation along with the endothelium. Here, this dissertation hypothesizes that hypoxic vasodilation of blood vessels requires ATP release from the RBC that stimulates NO synthesis in the endothelium, resulting in vasodilation. To investigate this hypothesis, a microfluidic model capable of quantitatively determining NO and culturing endothelial cells near a flowing RBC channel is fabricated. Techniques for fabrication of microfluidic devices are reviewed, along with detection and cell culture systems integrated in microfluidic systems. First presented is a novel system for analysis of NO released from RBCs under hypoxic conditions that uses a polydimethylsiloxane (PDMS) based microfluidic device incorporating a polycarbonate membrane. This membrane separates a flowing RBC sample from fluorogenic probe, DAF-FM, which when reacted with NO, has a larger fluorescence emission. This device was designed to be integrated into a fluorescence plate reader to obtain readout, which was a significant improvement over prior systems requiring custom detection platforms or microscopes for readout. Using this technology, a significant increase in NO release from RBCs under hypoxic conditions was observed.Next endothelial cell culture was incorporated onto the membrane of the device, and inhibition studies performed to investigate the origin of NO which reaches beyond an endothelial layer. In this model system, NO measured above an endothelial layer is representative of that available to the smooth muscle to induce vasodilation. Using this system, which integrated novel approaches of using the DAF-FM probe for NO in an extracellular manner and plate reader detection, it was shown that under hypoxic conditions, an increase in NO detected above the endothelium only is observed when RBC ATP release function and endothelial NO synthesis function is present, suggesting a pathway of hypoxic vasodilation requiring RBC ATP release and endothelial NO productionAlso, technology was developed enabling electrochemical oxygen detection within a flowing channel on a microfluidic device using epoxy-immobilized gold and silver wires as working and reference electrodes, respectively. This presents an easily reusable and low cost platform to potentially vary then detect the oxygen concentration in a flowing cell sample prior to other analysis. This would allow the investigation of hypoxic systems at oxygen concentrations other than completely oxygenated, or completely deoxygenated. Lastly, in efforts to explore other applications of the polycarbonate membrane based microfluidic devices, in particular their potential utility in drug screening and development. To this end, transport of several selected pharmaceutical molecules with the membrane based devices was investigated. In this process, it was discovered that some of the more hydrophilic molecules can absorb into PDMS based devices. To remove this limitation, techniques were developed which use the available fabrication equipment to produce PDMS devices to fabricate polystyrene devices. As polystyrene is frequently used in cell culture applications, this should allow for future work to more readily transfer cell culture protocols and techniques to microfluidic systems.Thesis (Ph. D.)--Michigan State University, Chemistry, 2012Includes bibliographical reference

Pre-sleep alpha brain entrainment for chronic pain and sleep disturbance

Home-based neuromodulation is a potentially scalable option to help address the globally important challenge of chronic pain. Alpha entrainment is a neuromodulatory technique which has emerged as potentially helpful for pain. In this project it has been applied via a smartphone application called hBET which provides repetitive audio or visual stimulation at 10 Hz. The general aim is to study the feasibility and effect of home-based use of hBET delivered pre-sleep for people with chronic pain and sleep disturbance, in a way which helpfully informs future research. To fulfil this aim three studies are presented. In the first, an uncontrolled feasibility study, participants with chronic pain and disturbed sleep found the use of hBET at home acceptable and beneficial to symptoms. The high adherence rate and improvements in participant-reported measures of pain, sleep, mood and fatigue demonstrates the technique is feasible and clinically promising. The second study, a qualitative investigation into participants’ experience of engaging with hBET, contributes detailed learning on how the intended users interact with this technology which informs future development and provides new insights into how pain and sleep interact. The third study progresses the investigation by adding a sham control and real time home-based EEG monitoring, using a crossover randomised design. This trial confirms that hBET entrains alpha and results in an improvement in pain at night and sleep quality, compared to the sham control. It also demonstrates, for the first time in the literature, the feasibility of pre-sleep sensory alpha entrainment in conjunction with home EEG monitoring for individuals with chronic pain. Taken together, this body of work establishes the potential of sensory alpha entrainment as a management tool for chronic pain and sleep disturbance and informs the technical development of the intervention and future trial design

Stochastic Model for Surface Erosion Via Ion-Sputtering: Dynamical Evolution from Ripple Morphology to Rough Morphology

Surfaces eroded by ion-sputtering are sometimes observed to develop morphologies which are either ripple (periodic), or rough (non-periodic). We introduce a discrete stochastic model that allows us to interpret these experimental observations within a unified framework. We find that a periodic ripple morphology characterizes the initial stages of the evolution, whereas the surface displays self-affine scaling in the later time regime. Further, we argue that the stochastic continuum equation describing the surface height is a noisy version of the Kuramoto-Sivashinsky equation.Comment: 4 pages, 7 postscript figs., Revtex, to appear in Phys. Rev. Let

Strategies to limit the impact of nematode pressure on sugarcane productivity in the Isis

Two trials were done in this project. One was a continuation of work started under a previous GRDC/SRDC-funded activity, 'Strategies to improve the integration of legumes into cane based farming systems'. This trial aimed to assess the impact of trash and tillage management options and nematicide application on nematodes and crop performance. Methods and results are contained in the following publication: Halpin NV, Stirling GR, Rehbein WE, Quinn B, Jakins A, Ginns SP. The impact of trash and tillage management options and nematicide application on crop performance and plant-parasitic nematode populations in a sugarcane/peanut farming system. Proc. Aust. Soc. Sugar Cane Technol. 37, 192-203. Nematicide application in the plant crop significantly reduced total numbers of plant parasitic nematodes (PPN) but there was no impact on yield. Application of nematicide to the ratoon crop significantly reduced sugar yield. The study confirmed other work demonstrating that implementation of strategies like reduced tillage reduced populations of total PPN, suggesting that the soil was more suppressive to PPN in those treatments. The second trial, a variety trial, demonstrated the limited value of nematicide application in sugarcane farming systems. This study has highlighted that growers shouldn’t view nematicides as a ‘cure all’ for paddocks that have historically had high PPN numbers. Nematicides have high mammalian toxicity, have the potential to contaminate ground water (Kookana et al. 1995) and are costly. The cost of nematicide used in R1 was approx. $320 -$350/ha, adding $3.50/t of cane in a 100 t/ha crop. Also, our study demonstrated that a single nematicide treatment at the application rate registered for sugarcane is not very effective in reducing populations of nematode pests. There appears to be some levels of resistance to nematodes within the current suite of varieties available to the southern canelands. For example the soil in plots that were growing Q183 had 560% more root knot nematodes / 200mL soil compared to plots that grew Q245. The authors see great value in investment into a nematode screening program that could rate varieties into groups of susceptibility to both major sugarcane nematode pests. Such a rating could then be built into a decision support ‘tree’ or tool to better enable producers to select varieties on a paddock by paddock basis

Association of Accelerometry-Measured Physical Activity and Cardiovascular Events in Mobility-Limited Older Adults: The LIFE (Lifestyle Interventions and Independence for Elders) Study.

BACKGROUND:Data are sparse regarding the value of physical activity (PA) surveillance among older adults-particularly among those with mobility limitations. The objective of this study was to examine longitudinal associations between objectively measured daily PA and the incidence of cardiovascular events among older adults in the LIFE (Lifestyle Interventions and Independence for Elders) study. METHODS AND RESULTS:Cardiovascular events were adjudicated based on medical records review, and cardiovascular risk factors were controlled for in the analysis. Home-based activity data were collected by hip-worn accelerometers at baseline and at 6, 12, and 24 months postrandomization to either a physical activity or health education intervention. LIFE study participants (n=1590; age 78.9±5.2 [SD] years; 67.2% women) at baseline had an 11% lower incidence of experiencing a subsequent cardiovascular event per 500 steps taken per day based on activity data (hazard ratio, 0.89; 95% confidence interval, 0.84-0.96; P=0.001). At baseline, every 30 minutes spent performing activities ≥500 counts per minute (hazard ratio, 0.75; confidence interval, 0.65-0.89 [P=0.001]) were also associated with a lower incidence of cardiovascular events. Throughout follow-up (6, 12, and 24 months), both the number of steps per day (per 500 steps; hazard ratio, 0.90, confidence interval, 0.85-0.96 [P=0.001]) and duration of activity ≥500 counts per minute (per 30 minutes; hazard ratio, 0.76; confidence interval, 0.63-0.90 [P=0.002]) were significantly associated with lower cardiovascular event rates. CONCLUSIONS:Objective measurements of physical activity via accelerometry were associated with cardiovascular events among older adults with limited mobility (summary score >10 on the Short Physical Performance Battery) both using baseline and longitudinal data. CLINICAL TRIAL REGISTRATION:URL: http://www.clinicaltrials.gov. Unique identifier: NCT01072500

The Potential of Low-Tech Tools and Artificial Intelligence for Monitoring Blue Carbon in Greenland’s Deep Sea

Arctic environments are changing rapidly. To assess climate change impacts and guide conservation, there is a need to effectively monitor areas of high biodiversity that are difficult to access, such as the deep sea. Greenland (Kalaallit Nunaat), like many remote countries with large deep-sea exclusive economic zones (EEZs), lacks consistent access to the funding and logistics required to maintain advanced and expensive technologies for seafloor exploration. To fill this need, video and camera imaging technologies have been adapted to suit the unique requirements of Arctic environments and the social and economic needs of Greenland. Since 2015, a benthic monitoring program carried out by the Greenland Institute of Natural Resources (GINR) has provided the only large-scale, comprehensive survey in this region, including collection and analysis of photos and GoPro video footage recorded as deep as 1,600 m (Blicher, and Arboe, 2021). In line with the “collect once, use many times” principle, GINR is exploring the versatility of these data, which were originally designated for monitoring and evidence-based management. A potential research avenue for these data is polar blue carbon—the carbon stored and sequestered in ocean habitats—including benthic communities that either live on the seafloor (such as corals and sponges) or are transported there by ocean currents (such as algal detritus). This paper outlines Greenland’s affordable deep-sea technology, based on a towed camera system (Yesson, 2023), and its potential application to rapid, standardized artificial intelligence (AI)-based analysis

Outstanding challenges in the transferability of ecological models

Predictive models are central to many scientific disciplines and vital for informing management in a rapidly changing world. However, limited understanding of the accuracy and precision of models transferred to novel conditions (their ‘transferability’) undermines confidence in their predictions. Here, 50 experts identified priority knowledge gaps which, if filled, will most improve model transfers. These are summarized into six technical and six fundamental challenges, which underlie the combined need to intensify research on the determinants of ecological predictability, including species traits and data quality, and develop best practices for transferring models. Of high importance is the identification of a widely applicable set of transferability metrics, with appropriate tools to quantify the sources and impacts of prediction uncertainty under novel conditions

Peanut agronomy experiments with five varieties in the Bundaberg and Kingaroy regions in the 2021-22 season

This report summarises the results of the peanut agronomy experiments conducted at Bundaberg and Kingaroy during the 2021-22 season as part of the above project. The experiments were laid out in a split-plot design with three replications at each location. Five peanut varieties, including Holt, Alloway, Kairi, Wheeler and P85-p112-151 (P85), were assigned to main plots, and four plant populations, 6, 12, 18, and 24 plants per m2, were assigned to subplots. All varieties were runner types except Wheeler, which represented a 'Virginia' type. Planting was done by the precision planting 20/20® and vSet® electronic seed metering system. The experiments were irrigated using irrigation scheduling software Aquaman via the web-based 'Yield Prophet'