Abstract

We take a heterodimer multiscale reaction-diffusion model as a starting point and modify it to account for the nonlocality of the underlying processes. The resulting model is a coupled system of integro-differential equations. The effect of nonlocal interactions is quantified based on the comparisons of the newly developed model with its local counterpart. Our primary focus is given to the estimation of conversion times from healthy to toxic proteins. This is done based on the stability analysis of a simplified model, as well as on the fully coupled numerical implementation. Several clinically relevant patient proteopathies are highlighted. They include the primary tauopathy, as well as the secondary tauopathy where the sustained presence of toxic tau protein requires also to be accompanied by toxic amyloid-beta peptides. We demonstrate the dynamics of concentrations of toxic proteins under several clinically realistic scenarios. Finally, we carry out a detailed parametric study, providing further insight into the role of nonlinear effects controlled via the Holling type II functional response.

Abstract

In this study, it is aimed''' '''to determine the most measured writing constructs based on confirmatory factor analysis to evaluate the significant differences in the specifications of the EFL writing skills test between Iranian advanced and intermediate proficiency level learners. For this purpose, sequential combination method''' '''was performed to provide comprehensive answers to research questions. In the present study, 60 out of 114 Iranian language learners from Boroujerd Branch Azad University were selected as participants. Then, the quantitative stage was followed by the qualitative stage. The research tools included Oxford Placement Test (OPT), structured survey questionnaire, semi-structured interview, and writing tasks. The participants were divided into advanced and intermediate groups based on the students' writing skills scores. Moreover, independent t-tests as well as principal component analysis (PCA), were used to compare the advanced and intermediate groups. The results showed that there is a significant difference between Iranian learners with high and medium skill level in the most measured structures in the specifications of the Iranian EFL writing skills test. Most of the measured structures included mode, evaluation and mechanics, respectively.

Abstract

In this study, it is aimed to determine the most measured writing constructs based on confirmatory factor analysis to evaluate the significant differences in the specifications of the EFL writing skills test between Iranian advanced and intermediate proficiency level learners. For this purpose, sequential combination method was performed to provide comprehensive answers to research questions. In the present study, 60 out of 114 Iranian language learners from Boroujerd Branch Azad University were selected as participants. Then, the quantitative stage was followed by the qualitative stage. The research tools included Oxford Placement Test (OPT), structured survey questionnaire, semi-structured interview, and writing tasks. The participants were divided into advanced and intermediate groups based on the students' writing skills scores. Moreover, independent t-tests as well as principal component analysis (PCA), were used to compare the advanced and intermediate groups. The results showed that there is a significant difference between Iranian learners with high and medium skill level in the most measured structures in the specifications of the Iranian EFL writing skills test. Most of the measured structures included mode, evaluation and mechanics, respectively.