Differential-Difference Equations. By Richard Bellman and Kenneth L. Cooke. Pp. xvi, 465. 1963. (Academic Press)

Meta-analytic procedures for social research

In this paper, the existence and uniqueness of the equilibrium point and its global asymptotic stability are discussed for a general class of recurrent neural networks with time-varying delays and Lipschitz continuous activation functions. The neural network model considered includes the delayed Hopfield neural networks, bidirectional associative memory networks, and delayed cellular neural networks as its special cases. Several new sufficient conditions for ascertaining the existence, uniqueness, and global asymptotic stability of the equilibrium point of such recurrent neural networks are obtained by using the theory of topological degree and properties of nonsingular M-matrix, and constructing suitable Lyapunov functionals. The new criteria do not require the activation functions to be differentiable, bounded or monotone nondecreasing and the connection weight matrices to be symmetric. Some stability results from previous works are extended and improved. Two illustrative examples are given to demonstrate the effectiveness of the obtained results.

Global asymptotic stability of a general class of recurrent neural networks with time-varying delays

Stability problems of continuous-time recurrent neural networks have been extensively studied, and many papers have been published in the literature The purpose of this paper is to provide a comprehensive review of the research on stability of continuous-time recurrent neural networks, including Hopfield neural networks, Cohen-Grossberg neural networks, and related models Since time delay is inevitable in practice, stability results of recurrent neural networks with different classes of time delays are reviewed in detail For the case of delay-dependent stability, the results on how to deal with the constant/variable delay in recurrent neural networks are summarized The relationship among stability results in different forms, such as algebraic inequality forms, \(M\) -matrix forms, linear matrix inequality forms, and Lyapunov diagonal stability forms, is discussed and compared Some necessary and sufficient stability conditions for recurrent neural networks without time delays are also discussed Concluding remarks and future directions of stability analysis of recurrent neural networks are given

https://romisatriawahono.net/lecture/rm/survey/machine%20learning/Zhang%20-%20Stability%20Analysis%20of%20Continuous-Time%20Recurrent%20Neural%20Networks%20-2014.pdf

A Comprehensive Review of Stability Analysis of Continuous-Time Recurrent Neural Networks

Summary Background There are few primary care studies of the COVID-19 pandemic. We aimed to identify demographic and clinical risk factors for testing positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within the Oxford Royal College of General Practitioners (RCGP) Research and Surveillance Centre primary care network. Methods We analysed routinely collected, pseudonymised data for patients in the RCGP Research and Surveillance Centre primary care sentinel network who were tested for SARS-CoV-2 between Jan 28 and April 4, 2020. We used multivariable logistic regression models with multiple imputation to identify risk factors for positive SARS-CoV-2 tests within this surveillance network. Findings We identified 3802 SARS-CoV-2 test results, of which 587 were positive. In multivariable analysis, male sex was independently associated with testing positive for SARS-CoV-2 (296 [18·4%] of 1612 men vs 291 [13·3%] of 2190 women; adjusted odds ratio [OR] 1·55, 95% CI 1·27–1·89). Adults were at increased risk of testing positive for SARS-CoV-2 compared with children, and people aged 40–64 years were at greatest risk in the multivariable model (243 [18·5%] of 1316 adults aged 40–64 years vs 23 [4·6%] of 499 children; adjusted OR 5·36, 95% CI 3·28–8·76). Compared with white people, the adjusted odds of a positive test were greater in black people (388 [15·5%] of 2497 white people vs 36 [62·1%] of 58 black people; adjusted OR 4·75, 95% CI 2·65–8·51). People living in urban areas versus rural areas (476 [26·2%] of 1816 in urban areas vs 111 [5·6%] of 1986 in rural areas; adjusted OR 4·59, 95% CI 3·57–5·90) and in more deprived areas (197 [29·5%] of 668 in most deprived vs 143 [7·7%] of 1855 in least deprived; adjusted OR 2·03, 95% CI 1·51–2·71) were more likely to test positive. People with chronic kidney disease were more likely to test positive in the adjusted analysis (68 [32·9%] of 207 with chronic kidney disease vs 519 [14·4%] of 3595 without; adjusted OR 1·91, 95% CI 1·31–2·78), but there was no significant association with other chronic conditions in that analysis. We found increased odds of a positive test among people who are obese (142 [20·9%] of 680 people with obesity vs 171 [13·2%] of 1296 normal-weight people; adjusted OR 1·41, 95% CI 1·04–1·91). Notably, active smoking was linked with decreased odds of a positive test result (47 [11·4%] of 413 active smokers vs 201 [17·9%] of 1125 non-smokers; adjusted OR 0·49, 95% CI 0·34–0·71). Interpretation A positive SARS-CoV-2 test result in this primary care cohort was associated with similar risk factors as observed for severe outcomes of COVID-19 in hospital settings, except for smoking. We provide evidence of potential sociodemographic factors associated with a positive test, including deprivation, population density, ethnicity, and chronic kidney disease. Funding Wellcome Trust.

Risk factors for SARS-CoV-2 among patients in the Oxford Royal College of General Practitioners Research and Surveillance Centre primary care network: a cross-sectional study.

Results concerning the absolute stability of delayed neural networks

This paper describes a model that can forecast the daily number of occupied beds due to emergency admissions in an acute hospital Out of sample forecasts 32 day days in advance have an RMS error of 3% of the mean number of beds used for emergency admissions We find that the number of occupied beds due to emergency admissions is related to both air temperature and PHLS data on influenza like illnesses We find that a period of high volatility, indicated by GARCH errors, will result in an increase in waiting times in the A&E Department Furthermore volatility gives more warning of waiting times in A&E than total bed occupancy

Forecasting Demand of Emergency Care

On the Global Convergence of a Class of Functional Differential Equations with Applications in Neural Network Theory

Objective Prehabilitation is increasingly being used to mitigate treatment‐related complications and enhance recovery. An individual's state of health at diagnosis, including obesity, physical fitness and comorbidities, are influencing factors for the occurrence of adverse effects. This review explores whether prehabilitation works in improving health outcomes at or beyond the initial 30 days post‐treatment and considers the utility of prehabilitation before cancer treatment. Methods A database search was conducted for articles published with prehabilitation as a pre‐cancer treatment intervention between 2009 and 2017. Studies with no 30 days post‐treatment data were excluded. Outcomes post‐prehabilitation were extracted for physical function, nutrition and patient‐reported outcomes. Results Sixteen randomised controlled trials with a combined 2017 participants and six observational studies with 289 participants were included. Prehabilitation interventions provided multi‐modality components including exercise, nutrition and psychoeducational aspects. Prehabilitation improved gait, cardiopulmonary function, urinary continence, lung function and mood 30 days post‐treatment but was not consistent across studies. Conclusion When combined with rehabilitation, greater benefits were seen in 30‐day gait and physical functioning compared to prehabilitation alone. Large‐scale randomised studies are required to translate what is already known from feasibility studies to improve overall health and increase long‐term cancer patient outcomes.

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Prehabilitation for adults diagnosed with cancer: A systematic review of long-term physical function, nutrition and patient-reported outcomes

METHODS: A cross-sectional survey of men attending antenatal care with their partners at three London Maternity Units. We assessed level of pregnancy planning using the partner version of the London Measure of Unplanned Pregnancy (LMUP), preconception health behaviours, and whether they had sought information and health professional advice before conception. MAIN RESULTS: We recruited 573 men (91% response rate). Mean age was 34 years, 86% were in employment or full time education and 66% had a degree. Half were overweight or obese, 16% were still smoking and 79% had consumed alcohol in the three months before conception. Of 250 men answering questions about medication, a third were taking medication with potentially adverse effects on male reproductive health, while 23% reported taking pre-pregnancy vitamins. 46.9% had looked at information about pregnancy from a variety of sources, including online, before their partner became pregnant. Assessed by the LMUP, 74% of pregnancies were planned. Male 'planners' were more likely than other men to reduce smoking, reduce alcohol consumption and to eat more healthily in preparation for pregnancy. However, 57% took no action to improve their health. SIGNIFICANCE OF THE FINDINGS: In a sample of relatively educated men accompanying their partners on an antenatal visit, nearly half had made at least one positive health behaviour change before pregnancy, but half were overweight or obese and a third were on medication that could impair male reproductive health. These findings, together with a high prevalence of alcohol consumption and smoking, indicate the need for greater paternal preconception health awareness and care. Innovative ways to promote positive messages about fatherhood, including medication review as part of preconception care, should be evaluated for impact on improving paternal reproductive health and pregnancy and neonatal outcomes.

/pdf/preparation-for-fatherhood-a-survey-of-men-s-preconception-5bs804xynm.pdf

Mark Joy

Papers

Results concerning the absolute stability of delayed neural networks

Forecasting Demand of Emergency Care

On the Global Convergence of a Class of Functional Differential Equations with Applications in Neural Network Theory

Prehabilitation for adults diagnosed with cancer: A systematic review of long-term physical function, nutrition and patient-reported outcomes

Preparation for fatherhood: A survey of men's preconception health knowledge and behaviour in England