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Primary Model (primary + model)
Selected AbstractsInquiring into the Primary Model: Yi Jing and the Onto-Hermeneutical Tradition*JOURNAL OF CHINESE PHILOSOPHY, Issue 3-4 2003Chung-Ying Cheng [source] Modelling and predicting the effect of temperature, water activity and pH on growth of Streptococcus iniae in TilapiaJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2008K. Zhou Abstract Aims:, To evaluate and model the growth of Streptococcus iniae affect by temperatures (10,45°C), water activity (Aw; 0·995,0·957), and pH (5,8). Methods and Results:, Temperatures, Aw, and pH were adjusted. The behaviour of S. iniae was studied and modelled. Growth curves were fitted by using logistic, Gompertz, and Baranyi models. The maximum growth rates obtained from the primary model were then modelled as a function of temperature, Aw, and pH using the Belehradek-type models for secondary model. The optimum values for growth were found to be in the range of 35,40°C, Aw 0.995,1, and pH 6,7. The statistical characteristics of the models were validated by r2, mean square error, bias, and accuracy factors. The results of validation indicated that Baranyi model performed the best. Conclusions:, The effect of temperature, Aw/NaCl, pH control of S. iniae in tilapia could be satisfactorily predicted under current experimental conditions, and the proposed models could serve as a tool for this purpose. Significance and Impact of the Study:, The suggested predictive model can be used for risk assessment concerning S. iniae in tilapia. [source] Market Valuation of Successful versus Non-successful R&D Efforts in the Pharmaceutical IndustryJOURNAL OF BUSINESS FINANCE & ACCOUNTING, Issue 9-10 2004Rebecca Toppe Shortridge Abstract: This paper examines the relationship between a non-financial measure of successful research and development (R&D) efforts in the pharmaceutical industry and R&D expenditures. I hypothesize that the R&D of successful producers will be valued more by the market than the R&D of non-successful producers. The regression results support the hypothesis. In the primary model, R&D is not associated with price; however, the coefficient on the interaction between R&D and successful developers is positively related to stock price. This implies that the market values the R&D expenditures of successful developers but not the expenditures of less-successful developers. [source] GROWTH KINETICS OF CLOSTRIDIUM PERFRINGENS IN COOKED BEEF,JOURNAL OF FOOD SAFETY, Issue 2 2003LIHAN HUANG ABSTRACT The objective of this work was to investigate the growth kinetics of a three-strain cocktail of Clostridium perfringens in cooked beef. The study was conducted by growing the heat-activated spores in ground beef under isothermal conditions between 17,50C. A four-parameter Gompertz equation was used as a primary model to fit the growth curves along with a modified Ratkowsky model to analyze the temperature dependence of the bacterial growth. Results indicated that the Gompertz model could accurately describe the growth of C. perfringens in cooked beef. The estimated theoretical minimum, optimum, and maximum growth temperatures of this organism in cooked beef were 9.8, 47.1, and 50.8C, respectively. A linear relationship between the durations of the lag and exponential phases of growth curves was observed in this study. Such a linear relationship can be used to generate a linear isothermal growth curve complete with the lag, exponential, and stationary phases without complex mathematical computation. The kinetic models and growth parameters obtained from this study potentially can be applied to the food industry to design appropriate cooling schedules and estimate the growth of C. perfringens in thermally processed beef products under temperature abuse conditions. [source] Dynamic Predictive Model for Growth of Salmonella Enteritidis in Egg YolkJOURNAL OF FOOD SCIENCE, Issue 7 2007V. Gumudavelli ABSTRACT:,Salmonella Enteritidis (SE) contamination of poultry eggs is a major human health concern worldwide. The risk of SE from shell eggs can be significantly reduced through rapid cooling of eggs after they are laid and their storage under safe temperature conditions. Predictive models for the growth of SE in egg yolk under varying ambient temperature conditions (dynamic) were developed. The growth of SE in egg yolk under several isothermal conditions (10, 15, 20, 25, 30, 35, 37, 39, 41, and 43 °C) was determined. The Baranyi model, a primary model, was fitted with growth data for each temperature and corresponding maximum specific growth rates were estimated. Root mean squared error (RMSE) values were less than 0.44 log10 CFU/g and pseudo- R2 values were greater than 0.98 for the primary model fitting. For developing the secondary model, the estimated maximum specific growth rates were then modeled as a function of temperature using the modified Ratkowsky's equation. The RMSE and pseudo- R2 were 0.05/h and 0.99, respectively. A dynamic model was developed by integrating the primary and secondary models and solving it numerically using the 4th-order Runge,Kutta method to predict the growth of SE in egg yolk under varying temperature conditions. The integrated dynamic model was then validated with 4 temperature profiles (varying) such as linear heating, exponential heating, exponential cooling, and sinusoidal temperatures. The predicted values agreed well with the observed growth data with RMSE values less than 0.29 log10 CFU/g. The developed dynamic model can predict the growth SE in egg yolk under varying temperature profiles. [source] Atypical Fetal Prostate Development is Associated with Ipsilateral Hypoplasia of the Wolffian Ducts in the ACI RatTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 5 2010Luke E. Hofkamp Abstract For over a half century, the ACI (August × Copenhagen) rat has been a primary model for studying renal agenesis and ipsilateral hypoplasia (IHP) of the Wolffian-derived structures (WDS). Because the ACI rat is also used as a model for prostate research, it is important to examine the relationship of IHP and urogenital sinus (UGS) development. The prostate is dependent on androgens for proper growth and differentiation. Alteration in androgen production and/or delivery to the UGS has the potential to perturbate normal development. In this study, we investigate whether the ipsilateral loss of the WDS is associated with altered prostate development. Digital images of serial-sectioned fetal ACI rat UGS were used to create three-dimensional (3-D) surface-rendered models of the developing prostate, seminal vesicle, vas deferens, and utricle on gestational day 21. The number and volume of prostate ducts developing from the UGS were calculated from the 3-D model data. Animals exhibiting IHP had a significant decrease in total fetal prostate volume (40%; P < 0.005) with significant regional specific differences when compared with normal male ACI rats. Anatomical and histological differences in the utricle, abnormal histology of the ipsilateral testes, and a truncation of the ipsilateral Wolffian ductal mesenchyme were also seen in the animals with IHP. Additional research is needed to further understand the mechanisms and consequences of IHP on prostate growth and development. Alterations to normal prenatal development of the male accessory sex organs can have important consequences for the growth and morphology of the adult gland. Anat Rec, 2010. © 2010 Wiley-Liss, Inc. [source] | |||||||||||||