The entropy rate of Linear Additive Markov Processes.

This work derives a theoretical value for the entropy of a Linear Additive Markov Process (LAMP), an expressive but simple model able to generate sequences with a given autocorrelation structure. Our research establishes that the theoretical entropy rate of a LAMP model is equivalent to the theoretical entropy rate of the underlying first-order Markov Chain. The LAMP model captures complex relationships and long-range dependencies in data with similar expressibility to a higher-order Markov process. While a higher-order Markov process has a polynomial parameter space, a LAMP model is characterised only by a probability distribution and the transition matrix of an underlying first-order Markov Chain. This surprising result can be explained by the information balance between the additional structure imposed by the next state distribution of the LAMP model, and the additional randomness of each new transition. Understanding the entropy of the LAMP model provides a tool to model complex dependencies in data while retaining useful theoretical results. To emphasise the practical applications, we use the LAMP model to estimate the entropy rate of the LastFM, BrightKite, Wikispeedia and Reuters-21578 datasets. We compare estimates calculated using frequency probability estimates, a first-order Markov model and the LAMP model, also considering two approaches to ensure the transition matrix is irreducible. In most cases the LAMP entropy rates are lower than those of the alternatives, suggesting that LAMP model is better at accommodating structural dependencies in the processes, achieving a more accurate estimate of the true entropy.

Effect of infection control education program on childcare educator knowledge and confidence.

ISSUE ADDRESSED: Childcare educator knowledge gaps in infection control practices and outbreak management. This can contribute to the well-reported issue of transmission of infectious diseases in childcare centres and the associated health and economic costs. METHODS: A health promotion program in the form of an educational slideshow presentation with interactive question/answer component was developed and offered to all childcare centre staff in the Wide Bay region, Queensland. RESULTS: Childcare educators who participated in the education sessions reported a significant increase in their knowledge and confidence in outbreak management on pre- and post-intervention self-assessment. CONCLUSIONS: Simple educational programs can significantly improve the self-assessed knowledge and confidence of childcare educators in managing infectious diseases. SO WHAT?: Improving knowledge and confidence of childcare centre staff in managing basic infectious diseases can help reduce the health and economic impacts of these infections. Simple educational health promotion programs could be introduced as part of an orientation program for new staff, or refreshers for existing staff.

Evolving epidemiology of Q fever in Wide Bay.

Abstract: Q fever is a notifiable disease in Australia due to its public health significance. Recent data in the Wide Bay region (Queensland, Australia) suggests a rising number and changing geographical distribution of Q fever cases. This study aims to evaluate these changes through analysis of data from Queensland Health's Notifiable Conditions System (NoCS) over a ten-year period. A comparison was made between the recent five-year period (2018-2022) and the preceding five-year period (2013-2017) with reference to incidence rates, location of cases and likely exposures. Incidence rates of Q fever showed an upward trend over time, particularly in urban areas. This highlights the need for increased clinical suspicion, improved awareness among the community and healthcare providers, and potentially broadening of vaccination recommendations in the future.

Case Report: Unexpected Remission From Extreme and Enduring Bulimia Nervosa With Repeated Ketamine Assisted Psychotherapy.

Background: Bulimia nervosa is a disabling psychiatric disorder that considerably impairs physical health, disrupts psychosocial functioning, and reduces overall quality of life. Despite available treatment, less than half of sufferers achieve recovery and approximately a third become chronically ill. Extreme and enduring cases are particularly resistant to first-line treatment, namely antidepressants and cognitive behavioral therapy, and have the highest rate of premature mortality. Here, we demonstrate that in such cases, repeated sessions of ketamine assisted psychotherapy (KAP) is an effective treatment alternative for improving symptoms. Case Presentation: A 21-year-old woman presented with extreme and enduring bulimia nervosa. She reported recurrent binge-eating and purging by self-induced vomiting 40 episodes per day, which proved refractory to both pharmacological and behavioral treatment at the outpatient, residential, and inpatient level. Provided this, her physician recommended repeated KAP as an exploratory and off-label intervention for her eating disorder. The patient underwent three courses of KAP over 3 months, with each course consisting of six sessions scheduled twice weekly. She showed dramatic reductions in binge-eating and purging following the first course of treatment that continued with the second and third. Complete cessation of behavioral symptoms was achieved 3 months post-treatment. Her remission has sustained for over 1 year to date. Conclusions: To our knowledge, this is the first report of repeated KAP used to treat bulimia nervosa that led to complete and sustained remission, a rare outcome for severe and enduring cases, let alone extreme ones. Additionally, it highlights the degree to which KAP can be tailored at the individual level based on symptom severity and treatment response. While its mechanism of action is unclear, repeated KAP is a promising intervention for bulimia nervosa that warrants future research and clinical practice consideration.

A Review of Shannon and Differential Entropy Rate Estimation.

In this paper, we present a review of Shannon and differential entropy rate estimation techniques. Entropy rate, which measures the average information gain from a stochastic process, is a measure of uncertainty and complexity of a stochastic process. We discuss the estimation of entropy rate from empirical data, and review both parametric and non-parametric techniques. We look at many different assumptions on properties of the processes for parametric processes, in particular focussing on Markov and Gaussian assumptions. Non-parametric estimation relies on limit theorems which involve the entropy rate from observations, and to discuss these, we introduce some theory and the practical implementations of estimators of this type.

Impact of the COVID-19 pandemic on South Australia.

ObjectiveThis study assessed the impact of the COVID-19 pandemic on emergency departments (EDs) in South Australia, measured by changes in the number and casemix of patients in the system over time.MethodsData from the South Australia Emergency Department Dashboard, updated every 30min, were analysed for the period 4 October-21 December 2020. The Dashboard reports live counts of the number and type of patients in each of the six adult metropolitan public EDs in Adelaide, South Australia.ResultsThere was a significant difference in the mean daily average occupied ED capacity before and during two distinct increases in COVID-19 cases in South Australia. An increase in COVID-19 cases coincided with a decrease in patients in EDs (Pearson's r=-0.93 and -0.67; P<0.001 for both). Presentations in Australasian Triage Scale (ATS) Categories 2-5 decreased during these periods, whereas ATS Category 1 stayed constant. Mental health patients continued to present to the ED, despite the overall drop in ED presentations.ConclusionsDuring the two periods of COVID-19 case growth in South Australia, there was a significant drop in the number of patients presenting to the major public EDs and a change in the casemix of patients over time.What is known about the topic?EDs in Australia often operate at or over capacity, with frequent reports of ambulance ramping, access block and long waiting times. There have been reports internationally of significant declines in ED presentations throughout the COVID-19 pandemic.What does this paper add?This paper uses a novel publicly available data source that is available in real time to contribute a new perspective from South Australia, which has experienced two distinct periods of strict restrictions and lockdown. The research showed that the number of mental health presentations remained consistently high, despite a significant overall decline in ED occupancy.What are the implications for practitioners?This study demonstrates that South Australians are accessing emergency medical treatment differently in response to the COVID-19 pandemic. In the context of an overall decline in presentation numbers, the number of mental health-related presentations has not changed significantly, suggesting that this trend should be closely monitored. The findings corroborate the national concern that unwell people have avoided accessing emergency medical care during the pandemic, leading to worse outcomes and increased need for healthcare resources at a later date. It will be important to monitor and quickly detect further changes in ED usage using real-time data as the pandemic evolves, as well as in any future significant health crises.

How the Avengers assemble: Ecological modelling of effective cast sizes for movies.

The number of characters in a movie is an important feature. However, it is non-trivial to measure directly, for example naive metrics such as the number of credited characters vary wildly. Here, we show that a metric based on the notion of ecological diversity as expressed through a Shannon-entropy based metric can characterise the number of characters in a movie, and is useful in taxonomic classification. We also show how the metric can be generalised using Jensen-Shannon divergence to provide a measure of the similarity of characters appearing in different movies, for instance of use in recommendation systems, e.g., Netflix. We apply our measures to the Marvel Cinematic Universe (MCU), and show what they teach us about this highly successful franchise of movies. In particular, these measures provide a useful predictor of success for films in the MCU, as well as a natural means to understand the relationships between the stories in the overall film arc.

The "robust yet fragile" nature of the Internet.

The search for unifying properties of complex networks is popular, challenging, and important. For modeling approaches that focus on robustness and fragility as unifying concepts, the Internet is an especially attractive case study, mainly because its applications are ubiquitous and pervasive, and widely available exposition exists at every level of detail. Nevertheless, alternative approaches to modeling the Internet often make extremely different assumptions and derive opposite conclusions about fundamental properties of one and the same system. Fortunately, a detailed understanding of Internet technology combined with a unique ability to measure the network means that these differences can be understood thoroughly and resolved unambiguously. This article aims to make recent results of this process accessible beyond Internet specialists to the broader scientific community and to clarify several sources of basic methodological differences that are relevant beyond either the Internet or the two specific approaches focused on here (i.e., scale-free networks and highly optimized tolerance networks).