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13. Where has all the influenza gone? The impact of COVID-19 on the circulation of influenza and other respiratory viruses, Australia, March to September 2020.

Author

Sullivan, Sheena, Carlson, Sandra, Cheng, Allen, Chilver, Monique, Dwyer, Dominic, Irwin, Melissa, Kok, Jen, Macartney, Kristine, MacLachlan, Jennifer, Minney-Smith, Cara, Smith, David, Stocks, Nigel, Taylor, Janette, and Barr, Ian

Subjects
influenza, non-pharmaceutical interventions, respiratory syncytial virus, rhinoviruses, travel restrictions, Australia, COVID-19, Coronavirus, Coronavirus Infections, Disease Notification, Epidemiological Monitoring, Female, Humans, Influenza, Human, Male, Pandemics, Population Surveillance, Respiratory Tract Infections, SARS-CoV-2, Seasons, Sentinel Surveillance
Abstract

The coronavirus disease pandemic was declared in March 2020, as the southern hemispheres winter approached. Australia expected co-circulation of severe acute respiratory syndrome coronavirus 2, influenza and other seasonal respiratory viruses. However, influenza notifications were 7,029 (March-September) compared with an average 149,832 for the same period in 2015-2019 [corrected], despite substantial testing. Restrictions on movement within and into Australia may have temporarily eliminated influenza. Other respiratory pathogens also showed remarkably changed activity in 2020.

Published
2020

15. Gender-specific aspects of socialisation and risk of cardiovascular disease among community-dwelling older adults: a prospective cohort study using machine learning algorithms and a conventional method

Author

Teshale, Achamyeleh Birhanu, primary, Htun, Htet Lin, additional, Owen, Alice J., additional, Ryan, Joanne, additional, Baker, JR, additional, Vered, Mor, additional, Reid, Christopher M, additional, Woods, Robyn L., additional, Berk, Michael, additional, Tonkin, Andrew, additional, Neumann, Johannes T, additional, Kilkenny, Monique F, additional, Phyo, Aung Zaw Zaw, additional, Nelson, Mark R, additional, Stocks, Nigel, additional, Britt, Carlene, additional, and Freak-Poli, Rosanne, additional

Published
2024
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18. Daily low‐dose aspirin and blood pressure in community‐dwelling older adults.

Author

Ernst, Michael E., Phan, Kevin, Nelson, Mark R., Woods, Robyn L., Fravel, Michelle A., Beilin, Lawrence, Orchard, Suzanne G., Zhou, Zhen, Polkinghorne, Kevan R., Broder, Jonathan C., Margolis, Karen L., Reid, Christopher M., Stocks, Nigel, Chowdhury, Enayet, and Wolfe, Rory

Abstract

High‐quality randomized trial evidence is lacking on whether low‐dose aspirin exerts significant effects on blood pressure (BP) in older adults. The authors assessed longitudinal BP changes in participants enrolled in ASPirin in Reducing Events in the Elderly (ASPREE), a randomized, placebo‐controlled trial of 100 mg daily aspirin in 19 114 community‐dwelling Australian and U.S. adults without cardiovascular disease (CVD), dementia, or independence‐limiting physical disability. Participants' BP was recorded at baseline and annual study visits, and managed by their usual care provider. BP trajectories for aspirin versus placebo during 4.7 years of follow‐up were examined for systolic and diastolic BP separately, using linear mixed models to account for between and within‐individual variability in BP. Analyses by subgroups were also explored with inclusion of interaction terms in the models. The difference in mean change in systolic BP between aspirin and placebo during study follow‐up was −0.03 mm Hg (95% confidence interval [CI]: −0.13, 0.07; p =.541) (aspirin minus placebo), while the mean difference for change in diastolic BP was −0.05 mm Hg (95% CI: –0.11, 0.01; p =.094). These small, non‐significant differences in BP change between the aspirin and placebo groups were consistent across baseline levels of BP and antihypertensive treatment status (treated/untreated). Likewise, subgroups of age, sex, chronic kidney disease, diabetes, and frailty revealed no interaction effect between the subgroup, aspirin treatment, and time. Interval‐censored Cox proportional hazards regression showed no difference in rates of incident treated hypertension between aspirin and placebo‐treated participants. The authors conclude that daily low‐dose aspirin does not significantly affect BP in older adults when managed by usual care. [ABSTRACT FROM AUTHOR]

Published
2024
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22. Abstract 12463: Low-Density-Lipoprotein Cholesterol and Mortality Outcomes Among Healthy Older Adults Not Taking Lipid-Lowering Agents: A Cohort Study With 12,334 Participants

Author

Zhou, Zhen, Tonkin, Andrew M, Curtis, Andrea J, Murray, Anne, Zhu, Chao, Reid, Christopher, Williamson, Jeff, Ryan, Joanne, McNeil, John J, Beilin, Lawrence J, Ernst, Michael E, Stocks, Nigel, Lacaze, Paul, Shah, Raj, Woods, Robyn, Wolfe, Rory, Gall, Seana L, Zoungas, Sophia, Orchard, Suzanne, and Nelson, Mark R

Published
2022
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24. Low interim influenza vaccine effectiveness, Australia, 1 May to 24 September 2017.

Author

Sullivan, Sheena, Chilver, Monique, Carville, Kylie, Deng, Yi-Mo, Grant, Kristina, Higgins, Geoff, Komadina, Naomi, Leung, Vivian, Minney-Smith, Cara, Teng, Don, Tran, Thomas, Stocks, Nigel, and Fielding, James

Subjects
Australia, epidemiology, influenza, influenza-like illness - ILI, surveillance, vaccines and immunisation, viral infections, Adolescent, Adult, Aged, Aged, 80 and over, Australia, Child, Child, Preschool, Female, Humans, Influenza A Virus, H1N1 Subtype, Influenza A Virus, H3N2 Subtype, Influenza B virus, Influenza Vaccines, Influenza, Human, Laboratories, Male, Middle Aged, Outcome Assessment, Health Care, RNA, Viral, Seasons, Sentinel Surveillance, Sequence Analysis, DNA, Vaccination, Vaccine Potency, Vaccines, Inactivated, Young Adult
Abstract

In 2017, influenza seasonal activity was high in the southern hemisphere. We present interim influenza vaccine effectiveness (VE) estimates from Australia. Adjusted VE was low overall at 33% (95% confidence interval (CI): 17 to 46), 50% (95% CI: 8 to 74) for A(H1)pdm09, 10% (95% CI: -16 to 31) for A(H3) and 57% (95% CI: 41 to 69) for influenza B. For A(H3), VE was poorer for those vaccinated in the current and prior seasons.

Published
2017

25. National Hypertension Taskforce of Australia: a roadmap to achieve 70% blood pressure control in Australia by 2030

Author

Schutte, Aletta E, Bennett, Belinda, Chow, Clara K, Cloud, Geoffrey C, Doyle, Kerry, Girdis, Zoe, Golledge, Jonathan, Goodman, Andrew, Hespe, Charlotte M, Hsu, Meng P, James, Sharon, Jennings, Garry, Khan, Taskeen, Lee, Audrey, Murphy, Lisa, Nelson, Mark R, Nicholls, Stephen J, Raffoul, Natalie, Robson, Breonny, Rodgers, Anthony, Sanders, Andrea, Shang, Catherine, Sharman, James E, Stocks, Nigel P, Usherwood, Tim, Webster, Ruth, Yang, Jun, and Schlaich, Markus

Published
2024
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26. Analysis of Spectrum Occupancy Using Machine Learning Algorithms

Author

Azmat, Freeha, Chen, Yunfei, and Stocks, Nigel

Subjects
Computer Science - Networking and Internet Architecture, Computer Science - Learning
Abstract

In this paper, we analyze the spectrum occupancy using different machine learning techniques. Both supervised techniques (naive Bayesian classifier (NBC), decision trees (DT), support vector machine (SVM), linear regression (LR)) and unsupervised algorithm (hidden markov model (HMM)) are studied to find the best technique with the highest classification accuracy (CA). A detailed comparison of the supervised and unsupervised algorithms in terms of the computational time and classification accuracy is performed. The classified occupancy status is further utilized to evaluate the probability of secondary user outage for the future time slots, which can be used by system designers to define spectrum allocation and spectrum sharing policies. Numerical results show that SVM is the best algorithm among all the supervised and unsupervised classifiers. Based on this, we proposed a new SVM algorithm by combining it with fire fly algorithm (FFA), which is shown to outperform all other algorithms., Comment: 21 pages, 6 figures

Published
2015

27. Engineering Scalable Digital Circuits From Non-digital Genetic Components

Author

Nikitin, Alexander P., Garcia–Ojalvo, Jordi, Stocks, Nigel G., Abarbanel, Henry D. I., Series Editor, Braha, Dan, Series Editor, Érdi, Péter, Series Editor, Friston, Karl J., Series Editor, Haken, Hermann, Series Editor, Jirsa, Viktor, Series Editor, Kacprzyk, Janusz, Series Editor, Kaneko, Kunihiko, Series Editor, Kelso, Scott, Founding Editor, Kirkilionis, Markus, Series Editor, Kurths, Jürgen, Series Editor, Menezes, Ronaldo, Series Editor, Nowak, Andrzej, Series Editor, Qudrat-Ullah, Hassan, Series Editor, Reichl, Linda, Series Editor, Schuster, Peter, Series Editor, Schweitzer, Frank, Series Editor, Sornette, Didier, Series Editor, Thurner, Stefan, Series Editor, In, Visarath, editor, Longhini, Patrick, editor, and Palacios, Antonio, editor

Published
2019
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29. Long-term blood pressure variability and frailty risk in older adults

Author

Fravel, Michelle A., primary, Ernst, Michael E., additional, Woods, Robyn L., additional, Beilin, Lawrence, additional, Zhou, Zhen, additional, Orchard, Suzanne G., additional, Chowdhury, Enayet, additional, Reid, Christopher M., additional, Saifuddin Ekram, ARM, additional, Espinoza, Sara E., additional, Nelson, Mark R., additional, Stocks, Nigel, additional, Polkinghorne, Kevan R., additional, Wolfe, Rory, additional, and Ryan, Joanne, additional

Published
2023
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36. Stochastic Pooling Networks

Author

McDonnell, Mark D., Amblard, Pierre-Olivier, and Stocks, Nigel G.

Subjects
Condensed Matter - Statistical Mechanics, Condensed Matter - Disordered Systems and Neural Networks
Abstract

We introduce and define the concept of a stochastic pooling network (SPN), as a model for sensor systems where redundancy and two forms of 'noise' -- lossy compression and randomness -- interact in surprising ways. Our approach to analyzing SPNs is information theoretic. We define an SPN as a network with multiple nodes that each produce noisy and compressed measurements of the same information. An SPN must combine all these measurements into a single further compressed network output, in a way dictated solely by naturally occurring physical properties -- i.e. pooling -- and yet causes no (or negligible) reduction in mutual information. This means SPNs exhibit redundancy reduction as an emergent property of pooling. The SPN concept is applicable to examples in biological neural coding, nano-electronics, distributed sensor networks, digital beamforming arrays, image processing, multiaccess communication networks and social networks. In most cases the randomness is assumed to be unavoidably present rather than deliberately introduced. We illustrate the central properties of SPNs for several case studies, where pooling occurs by summation, including nodes that are noisy scalar quantizers, and nodes with conditionally Poisson statistics. Other emergent properties of SPNs and some unsolved problems are also briefly discussed., Comment: Published, 14 pages of text, 42 references, 4 figures

Published
2009
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37. Low-Density-Lipoprotein Cholesterol and Mortality Outcomes Among Healthy Older Adults: A Post Hoc Analysis of ASPREE Trial.

Author

Zhou, Zhen, Tonkin, Andrew M, Curtis, Andrea J, Murray, Anne, Zhu, Chao, Reid, Christopher M, Williamson, Jeff D, Ryan, Joanne, McNeil, John J, Beilin, Lawrence J, Ernst, Michael E, Stocks, Nigel, Lacaze, Paul, Shah, Raj C, Woods, Robyn L, Wolfe, Rory, Gall, Seana, Zoungas, Sophia, Orchard, Suzanne G, and Nelson, Mark R

Subjects
OLDER people, CHOLESTEROL, CANCER-related mortality, LDL cholesterol, MORTALITY
Abstract

Background The prognostic implication of cholesterol levels in older adults remains uncertain. This study aimed to examine the relationship between low-density-lipoprotein cholesterol (LDL-c) and mortality outcomes in older individuals. Methods This post hoc analysis examined the associations of LDL-c levels with mortality risks from all-cause, cardiovascular disease (CVD), cancer, and combined non-CVD/noncancer conditions in a cohort of individuals aged ≥65 years from the ASPirin in Reducing Events in the Elderly trial (NCT01038583). At baseline, participants had no diagnosed dementia, physical disability, or CVD, and were not taking lipid-lowering agents. Outcome analyses were performed using multivariable Cox models. Results We analyzed 12 334 participants (mean age: 75.2 years). Over a median 7-year follow-up, 1 250 died. Restricted cubic splines found a U-shaped relation for LDL-c and all-cause mortality, cancer mortality, and noncancer/non-CVE mortality (nadir: 3.3–3.4 mmol/L); the risk of CVD mortality was similar at LDL-c below 3.3 mmol/L and increased above 3.3 mmol/L. Similar trends were observed in analyses modeling LDL-c by quartiles. When modeling LDL-c as a continuous variable, the risk of all-cause mortality, cancer mortality, and noncancer/non-CVD mortality was decreased by 9%, 16%, and 18%, respectively, per 1-mmol/L higher LDL-c, and the risk of CVD mortality was increased by 19% per 1-mmol/L higher LDL-c. Reduced all-cause and non-CVD/noncancer mortality risks were only significant in males but not females (p interaction < .05). Conclusions There were U-shaped relationships between LDL-c and all-cause mortality, cancer mortality, and noncancer/non-CVD mortality in healthy older adults. Higher LDL-c levels were associated with an increased risk of CVD mortality. Future studies are warranted to confirm our results. [ABSTRACT FROM AUTHOR]

Published
2024
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39. Association Between Triglycerides and Risk of Dementia in Community-Dwelling Older Adults: A Prospective Cohort Study

Author

Zhou, Zhen, primary, Ryan, Joanne, additional, Tonkin, Andrew M, additional, Zoungas, Sophia, additional, Lacaze, Paul, additional, Wolfe, Rory, additional, Orchard, Suzanne G, additional, Murray, Anne M, additional, Mcneil, John J, additional, Yu, Chenglong, additional, Watts, Gerald F, additional, Hussain, Sultana Monira, additional, Beilin, Lawrence J, additional, Ernst, Michael, additional, Stocks, Nigel, additional, Woods, Robyn L, additional, Zhu, Chao, additional, Reid, Christopher, additional, Shah, Raj C, additional, Chong, Trevor T, additional, Sood, Ajay, additional, Sheets, Kerry M, additional, and Nelson, Mark, additional

Published
2023
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40. Neural Population Coding is Optimized by Discrete Tuning Curves

Author

Nikitin, Alexander P., Stocks, Nigel G., Morse, Robert P., and McDonnell, Mark D.

Subjects
Quantitative Biology - Neurons and Cognition
Abstract

The sigmoidal tuning curve that maximizes the mutual information for a Poisson neuron, or population of Poisson neurons, is obtained. The optimal tuning curve is found to have a discrete structure that results in a quantization of the input signal. The number of quantization levels undergoes a hierarchy of phase transitions as the length of the coding window is varied. We postulate, using the mammalian auditory system as an example, that the presence of a subpopulation structure within a neural population is consistent with an optimal neural code., Comment: 7 pages total, including 2 figures, published by Physical Review Letters

Published
2008
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41. Maximally Informative Stimuli and Tuning Curves for Sigmoidal Rate-Coding Neurons and Populations

Author

McDonnell, Mark D. and Stocks, Nigel G.

Subjects
Quantitative Biology - Neurons and Cognition
Abstract

A general method for deriving maximally informative sigmoidal tuning curves for neural systems with small normalized variability is presented. The optimal tuning curve is a nonlinear function of the cumulative distribution function of the stimulus and depends on the mean-variance relationship of the neural system. The derivation is based on a known relationship between Shannon's mutual information and Fisher information, and the optimality of Jeffrey's prior. It relies on the existence of closed-form solutions to the converse problem of optimizing the stimulus distribution for a given tuning curve. It is shown that maximum mutual information corresponds to constant Fisher information only if the stimulus is uniformly distributed. As an example, the case of sub-Poisson binomial firing statistics is analyzed in detail., Comment: Accepted by Physical Review Letters. This revision updates figures and text

Published
2008
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42. Optimal stimulus and noise distributions for information transmission via suprathreshold stochastic resonance

Author

McDonnell, Mark D., Stocks, Nigel G., and Abbott, Derek

Subjects
Condensed Matter - Statistical Mechanics, Quantitative Biology - Neurons and Cognition
Abstract

Suprathreshold stochastic resonance (SSR) is a form of noise enhanced signal transmission that occurs in a parallel array of independently noisy identical threshold nonlinearities, including model neurons. Unlike most forms of stochastic resonance, the output response to suprathreshold random input signals of arbitrary magnitude is improved by the presence of even small amounts of noise. In this paper the information transmission performance of SSR in the limit of a large array size is considered. Using a relationship between Shannon's mutual information and Fisher information, a sufficient condition for optimality, i.e. channel capacity, is derived. It is shown that capacity is achieved when the signal distribution is Jeffrey's prior, as formed from the noise distribution, or when the noise distribution depends on the signal distribution via a cosine relationship. These results provide theoretical verification and justification for previous work in both computational neuroscience and electronics., Comment: Accepted for publication by Physical Review E, 28 pages of text and references, 5 figures, 2 tables

Published
2007
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44. Point singularities and suprathreshold stochastic resonance in optimal coding

Author

McDonnell, Mark D., Stocks, Nigel G., Pearce, Charles E. M., and Abbott, Derek

Subjects
Condensed Matter - Statistical Mechanics, Quantitative Biology - Neurons and Cognition
Abstract

Motivated by recent studies of population coding in theoretical neuroscience, we examine the optimality of a recently described form of stochastic resonance known as suprathreshold stochastic resonance, which occurs in populations of noisy threshold devices such as models of sensory neurons. Using the mutual information measure, it is shown numerically that for a random input signal, the optimal threshold distribution contains singularities. For large enough noise, this distribution consists of a single point and hence the optimal encoding is realized by the suprathreshold stochastic resonance effect. Furthermore, it is shown that a bifurcational pattern appears in the optimal threshold settings as the noise intensity increases. Fisher information is used to examine the behavior of the optimal threshold distribution as the population size approaches infinity., Comment: 11 pages, 3 figures, RevTeX

Published
2004
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48. Impact of the 2017 American Heart Association and American College of Cardiology hypertension guideline in aged individuals

Author

Chowdhury, Enayet Karim, Ernst, Michael E., Nelson, Mark, Margolis, Karen, Beilin, Lawrie J., Johnston, Collin, Woods, Robyn, Murray, Anne, Wolfe, Rory, Storey, Elsdon, Shah, Raj C., Lockery, Jessica, Tonkin, Andrew, Newman, Anne, Abhayaratna, Walter, Stocks, Nigel, Fitzgerald, Sharyn, Orchard, Suzanne, Trevaks, Ruth, Donnan, Geoffrey, Grimm, R., McNeil, John, and Reid, Christopher M.

Published
2020
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