OBJECTIVE Respiratory pressure-volume curves fitted to exponential equations have been used to assess disease severity and prognosis in spontaneously breathing patients with idiopathic pulmonary fibrosis. Sigmoidal equations have been used to fit pressure-volume curves for mechanically ventilated patients but not for idiopathic pulmonary fibrosis patients. We compared a sigmoidal model and an e...

Sigmoidal and double-sigmoidal dynamics are commonly observed in many areas of biology. Here we present sicegar, an R package for the automated fitting and classification of sigmoidal and double-sigmoidal data. The package categorizes data into one of three categories, "no signal," "sigmoidal," or "double-sigmoidal," by rigorously fitting a series of mathematical models to the data. The data is...

In the course of pursuing research on dinosaur growth rates (Myhrvold, 2013), I attempted to repli-cate the findings of Erickson et al. for Psittacosaurus lujiatunensis (Erickson et al., 2009a). In their study, they use femoral length measurements and age estimates for 80 specimens of P. lujiatunensis to estimate body mass and age, fit a growth curve, and construct a life table. These results w...

Recently there has been an increased interest in characterising the rates of alcoholic fermentations. Sigmoidal models have used to predict changes such as rate density decline. In this study, three published sigmoidal were assessed and fit industrial fermentation data. The first is four-parameter logistic model described ASBC Yeast-14 method. second a nested form function, adding extra paramet...

Increasing popularity of oat were accompanied with the introductions many new cultivars for last few decades. Aim this study to characterize growth and developments Kahraman, Küçükyayla, Yeniçeri, Sebat, Otağı Diriliş using sigmoidal models. Growth data comprised weekly observations dry weights stages three samplings two consecutive years. Results indicated that growing season determining facto...

Although catalyst deactivation rate greatly varies depending on many factors, including the catalyst structure, reactor feed composition, and operating conditions; it is usually inevitable. Since catalyst deactivation modeling has so far been poorly addressed in the literature, in the present study, nine experimental sets of cobalt based Fischer-Tropsch catalysts activity-time data were conside...