ABSTRACT
The usefulness of Bayesian statistical methods for the modelling of biochemical reactions is examined. With simulated data, it is shown that these methods can effectively fit mechanistic models of sequences of enzymatic reactions to experimental data. These methods have the advantages of being relatively easy to use and producing probability distributions for the model parameters rather than point estimates, allowing more informative inferences to be drawn. Three Markov Chain Monte Carlo algorithms are used to fit models to data from a sequence of four enzymatic reactions. The algorithms are evaluated with respect to the goodness-of-fit of the fitted models and the time to completion. It is shown that the algorithms produce essentially the same parameter distributions, but the time to completion varies.
Subject(s)
Biopolymers/metabolism , Models, Biological , Models, Statistical , Multienzyme Complexes/metabolism , Signal Transduction/physiology , Biochemistry/methods , Computer SimulationABSTRACT
STUDY OBJECTIVES: To determine the diagnostic utility of a nasal cannula/pressure transducer (NC), in comparison to thermistor (TH), during routine, clinical nocturnal polysomnography (NPSG). DESIGN: We analyzed the respiratory arousal index (RAI) using TH (RAI-TH) or NC (RAI-NC) in patients with suspected sleep-disordered breathing (SDB). SETTING: Sleep disorders center of a university-affiliated teaching hospital. PATIENTS: Fifty consecutive, nonselected patients referred for evaluation of suspected SDB. MEASUREMENTS AND RESULTS: Twenty patients were found to have obstructive sleep apnea/hypopnea syndrome (OSA), 25 had upper airway resistance syndrome (UARS), and 5 had primary snoring (PS). Mean RAI-NC was greater than the mean RAI-TH by 25%, 302%, and 500% in OSA, UARS, and PS, respectively. RAI-NC was >/= 14 (mean, 25.2) in UARS and < 14 (mean, 9) in PS. Mean RAI-TH was 8.4 in UARS and 1.8 in PS, with significant overlap between the two groups. CONCLUSIONS: NC is more sensitive than TH in detecting respiratory events during NPSG and may represent a simple, objective means to identify UARS among patients with a range of SDB.
Subject(s)
Airway Obstruction/diagnosis , Airway Resistance , Catheterization/instrumentation , Polysomnography/methods , Adult , Aged , Aged, 80 and over , Airway Obstruction/physiopathology , Airway Resistance/physiology , Circadian Rhythm , Female , Humans , Male , Middle Aged , Nose , Retrospective Studies , Sensitivity and Specificity , Sleep Apnea Syndromes/diagnosis , Sleep Apnea Syndromes/physiopathology , Snoring/diagnosis , Snoring/physiopathology , Syndrome , Transducers, PressureABSTRACT
The impact of dredging on a biological community is assessed through the use of log-linear modelling. The experiment is designed as a nested design and the data is collected at several stations within each of natural and dredged areas. The log-linear modelling analysis indicates the dredging has an impact on the abundance of dominant species.
