M Small

Publications (5)50.8 Total impact

• Source

  Available from: polyu.edu.hk

  Article: Complex network from pseudoperiodic time series: topology versus dynamics.

  J Zhang, M Small
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  ABSTRACT: We construct complex networks from pseudoperiodic time series, with each cycle represented by a single node in the network. We investigate the statistical properties of these networks for various time series and find that time series with different dynamics exhibit distinct topological structures. Specifically, noisy periodic signals correspond to random networks, and chaotic time series generate networks that exhibit small world and scale free features. We show that this distinction in topological structure results from the hierarchy of unstable periodic orbits embedded in the chaotic attractor. Standard measures of structure in complex networks can therefore be applied to distinguish different dynamic regimes in time series. Application to human electrocardiograms shows that such statistical properties are able to differentiate between the sinus rhythm cardiograms of healthy volunteers and those of coronary care patients.
  Physical Review Letters 07/2006; 96(23):238701. · 7.37 Impact Factor
• Source

  Available from: polyu.edu.hk

  Article: Detecting chaos in pseudoperiodic time series without embedding.

  J Zhang, X Luo, M Small
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  ABSTRACT: A different method is proposed to detect deterministic structure from a pseudoperiodic time series. By using the correlation coefficient as a measure of the distance between cycles, we are exempt from phase-space reconstruction and further construct a hierarchy of pseudocycle series that, in turn, preserve less determinism than the original time series. Appropriate statistics are then devised to reveal the temporal and spatial correlation encoded in this hierarchy of the pseudocycle series, which allows for a reliable detection of determinism and chaos in the original time series. We demonstrate that this method can reliably identify chaos in the presence of noise of different sources for both artificial data and experimental time series.
  Physical Review E 02/2006; 73(1 Pt 2):016216. · 2.26 Impact Factor
• Article: Primary prevention of cardiovascular disease with atorvastatin in type 2 diabetes in the Collaborative Atorvastatin Diabetes Study (CARDS): multicentre randomised placebo-controlled trial

  Colhoun HM, Betteridge DJ, Durrington PN, Hitman GA, Neil HA, Livingstone SJ, Thomason MJ, Mackness MI, Charlton-Menys V, Fuller JH, [......], P Winocour, J Fraser, I A D O’Brien, B M Singh, J A Fulton, L Millar, SWarner, J N Harvey, P Jennings, J Thow
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  ABSTRACT: BACKGROUND: Type 2 diabetes is associated with a substantially increased risk of cardiovascular disease, but the role of lipid-lowering therapy with statins for the primary prevention of cardiovascular disease in diabetes is inadequately defined. We aimed to assess the effectiveness of atorvastatin 10 mg daily for primary prevention of major cardiovascular events in patients with type 2 diabetes without high concentrations of LDL-cholesterol. METHODS: 2838 patients aged 40-75 years in 132 centres in the UK and Ireland were randomised to placebo (n=1410) or atorvastatin 10 mg daily (n=1428). Study entrants had no documented previous history of cardiovascular disease, an LDL-cholesterol concentration of 4.14 mmol/L or lower, a fasting triglyceride amount of 6.78 mmol/L or less, and at least one of the following: retinopathy, albuminuria, current smoking, or hypertension. The primary endpoint was time to first occurrence of the following: acute coronary heart disease events, coronary revascularisation, or stroke. Analysis was by intention to treat. FINDINGS: The trial was terminated 2 years earlier than expected because the prespecified early stopping rule for efficacy had been met. Median duration of follow-up was 3.9 years (IQR 3.0-4.7). 127 patients allocated placebo (2.46 per 100 person-years at risk) and 83 allocated atorvastatin (1.54 per 100 person-years at risk) had at least one major cardiovascular event (rate reduction 37% [95% CI -52 to -17], p=0.001). Treatment would be expected to prevent at least 37 major vascular events per 1000 such people treated for 4 years. Assessed separately, acute coronary heart disease events were reduced by 36% (-55 to -9), coronary revascularisations by 31% (-59 to 16), and rate of stroke by 48% (-69 to -11). Atorvastatin reduced the death rate by 27% (-48 to 1, p=0.059). No excess of adverse events was noted in the atorvastatin group. INTERPRETATION: Atorvastatin 10 mg daily is safe and efficacious in reducing the risk of first cardiovascular disease events, including stroke, in patients with type 2 diabetes without high LDL-cholesterol. No justification is available for having a particular threshold level of LDL-cholesterol as the sole arbiter of which patients with type 2 diabetes should receive statins. The debate about whether all people with this disorder warrant statin treatment should now focus on whether any patients are at sufficiently low risk for this treatment to be withheld.
  The Lancet 08/2004; 364:685-696. · 38.28 Impact Factor
• Article: Baseline characteristics in the Collaborative AtoRvastatin Diabetes Study (CARDS) in patients with Type 2 diabetes

  Thomason MJ, Colhoun HM, Livingstone SJ, Mackness MI, Betteridge DJ, Durrington PN, Hitman GA, Neil HA, Fuller JH, CARDS Investigators, [......], P. Winocour, J. Fraser, I. A. D. O’Brien, B. M. Singh, J. A. Fulton, L. Millar, S. Warner, J. N. Harvey, P. Jennings, J. Thow
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  ABSTRACT: AIM: To describe baseline characteristics of patients in the Collaborative AtoRvastatin Diabetes Study (CARDS), a randomized, placebo-controlled trial of lipid lowering with atorvastatin 10 mg daily for the primary prevention of major cardiovascular events in patients with Type 2 diabetes. METHODS: The main eligibility criteria were Type 2 diabetes, age 40-75 years, no previous history of coronary heart disease, stroke or other major cardiovascular events, a documented history of at least one of retinopathy, micro- or macroalbuminuria, hypertension or current smoking, LDL-cholesterol < or = 4.14 mmol/l and triglycerides < or = 6.78 mmol/l. RESULTS: Randomization of 2838 persons (909 women) into CARDS was completed in June 2001. At entry, mean age was 62 years, 12% were over 70 years old and median duration of diabetes was 6 years. Median fasting lipid levels were total cholesterol 5.4 mmol/l, LDL-cholesterol 3.1 mmol/l, HDL-cholesterol 1.4 mmol/l and triglyceride 1.7 mmol/l. There was a documented history of retinopathy in 30% of patients, micro/macroalbuminuria in 11% (additionally 17% had micro/macroalbuminuria based on two elevated pretreatment measurements of albumin-creatinine ratios), hypertension in 79% and 23% were current smokers. CONCLUSION: CARDS will contribute importantly to the evidence for the macrovascular and microvascular benefits of lipid lowering with atorvastatin in patients with Type 2 diabetes. The results are likely to have important implications for the management of patients. Copyright 2004 Diabetes UK
  Diabetic Medicine 08/2004; 21(8):901-905. · 2.90 Impact Factor
• Article: Prescription and use of disposable plastic insulin syringes

  C Heatley, B M Fisher, M Small
  Practical Diabetes International 01/1990; 7(1):33-34.