Dynamic fluctuation model of complex networks with weight scaling behavior and its application to airport networks

In the IRT person-fluctuation model, the individual trait levels fluctuate within a single test administration whereas the items have fixed locations. This article studies the relations between the person and item parameters of this model and two central properties of item and test scores: temporal stability and external validity. For temporal stability, formulas are derived for predicting and interpreting item response changes in a test-retest situation on the basis of the individual fluctuations. As for validity, formulas are derived for obtaining disattenuated estimates and for predicting changes in validity in groups with different levels of fluctuation. These latter formulas are related to previous research in the person-fit domain. The results obtained and the relations discussed are illustrated with an empirical example.

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The Mean and Standard Deviation of Cross-Modality Matches: A Study of Individual Scaling Behavior

PsycEXTRA Dataset ◽

10.1037/e546832009-001 ◽

1970 ◽

Author(s):

Jan Hosman ◽

Gunnar Borg

Keyword(s):

Standard Deviation ◽

Scaling Behavior ◽

The Mean

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Computational Investigations of the Transmembrane Italian-Mutant (E22K) 3A\(\beta_{11 - 40}\) in Aqueous Solution

Communications in Physics ◽

10.15625/0868-3166/28/3/12773 ◽

2018 ◽

Vol 28 (3) ◽

pp. 265 ◽

Cited By ~ 1

Author(s):

Son Tung Ngo

Keyword(s):

Structural Changes ◽

Replica Exchange ◽

Aβ Oligomers ◽

Replica Exchange Molecular Dynamics ◽

Charged Residue ◽

Intermolecular Contacts ◽

Structural Details ◽

Positively Charged ◽

Dynamic Fluctuation ◽

Good Agreement

The Amyloid beta (Aβ) oligomers are characterized as critical cytotoxic materials in Alzheimer’s disease (AD) pathogenesis. Structural details of transmembrane oligomers are inevitably necessary to design/search potential inhibitor due to treat AD. However, the experimental detections for structural modify of low-order Aβ oligomers are precluded due to the extremely dynamic fluctuation of the oligomers. In this project, the transmembrane Italian-mutant (E22K) 3Aβ11-40 (tmE22K 3Aβ11-40) was extensively investigated upon the temperature replica exchange molecular dynamics (REMD) simulations. The structural changes of the trimer when replacing the negative charged residue E22 by a positively charged residue K were monitored over simulation intervals. The oligomer size was turned to be larger and the increase of β-content was recorded. The momentous gain of intermolecular contacts with DPPC molecules implies that tmE22K 3Aβ11-40 easier self-inserts into the membrane than the WT one. Furthermore, the tighter interaction between constituting monomers was indicated implying that the E22K mutation probably enhances the Aβ fibril formation. The results are in good agreement with experiments that E22K amyloid is self-aggregate faster than the WT form. Details information of tmE22K trimer structure and kinetics probably yield the understanding of AD mechanism.

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