37 research outputs found
Prediction of cognitive impairment via deep learning trained with multi-center neuropsychological test data
Background
Neuropsychological tests (NPTs) are important tools for informing diagnoses of cognitive impairment (CI). However, interpreting NPTs requires specialists and is thus time-consuming. To streamline the application of NPTs in clinical settings, we developed and evaluated the accuracy of a machine learning algorithm using multi-center NPT data.
Methods
Multi-center data were obtained from 14,926 formal neuropsychological assessments (Seoul Neuropsychological Screening Battery), which were classified into normal cognition (NC), mild cognitive impairment (MCI) and Alzheimers disease dementia (ADD). We trained a machine learning model with artificial neural network algorithm using TensorFlow (https://www.tensorflow.org) to distinguish cognitive state with the 46-variable data and measured prediction accuracies from 10 randomly selected datasets. The features of the NPT were listed in order of their contribution to the outcome using Recursive Feature Elimination.
Results
The ten times mean accuracies of identifying CI (MCI and ADD) achieved by 96.66 ± 0.52% of the balanced dataset and 97.23 ± 0.32% of the clinic-based dataset, and the accuracies for predicting cognitive states (NC, MCI or ADD) were 95.49 ± 0.53 and 96.34 ± 1.03%. The sensitivity to the detection CI and MCI in the balanced dataset were 96.0 and 96.0%, and the specificity were 96.8 and 97.4%, respectively. The time orientation and 3-word recall score of MMSE were highly ranked features in predicting CI and cognitive state. The twelve features reduced from 46 variable of NPTs with age and education had contributed to more than 90% accuracy in predicting cognitive impairment.
Conclusions
The machine learning algorithm for NPTs has suggested potential use as a reference in differentiating cognitive impairment in the clinical setting.The publication costs, design of the study, data management and writing the manuscript for this article were supported by the Ministry of Education of the Republic of Korea and the National Research Foundation of Korea (NRF-2017S1A6A3A01078538), Korea Ministry of Health & Welfare, and from
the Original Technology Research Program for Brain Science through the National Research Foundation of Korea funded by the Korean Government (MSIP; No. 2014M3C7A1064752)
Agentivity of passives and inchoatives in second language learners of English and Korean
Thesis (Ph.D.)--University of Hawaii at Manoa, 2008.Second language (L2) learners' overpassivization of unaccusatives such as '*the accident was happened' have been widely investigated. One popular account claims that L2 learners lexically causativize unaccusatives and then syntactically passivize them. This study suggests an alternative possibility: Passive unaccusatives may be caused by learners' confusion in the agentivity of passives and inchoatives. This study therefore explores whether L2 learners know the distinction between passives and inchoatives in terms of agentivity. (a) The window was Broken. (passive) (b) The window broke. (inchoative) Unlike inchoatives, passives imply the agent even if not expressed in the syntax.The results of the EFL study showed that L2 learners have knowledge of constructional meanings of passives and inchoatives but did not show their knowledge when there was no agent in context given as a stimulus for conceptualization. In the KFL study, L2 learners showed native-like knowledge of the passive and the inchoative in Korean. The results suggests that L2 learners' overpassivization can be caused by their incomplete knowledge of constructional meanings.This dissertation includes two studies: the English as a foreign language (EFL) and the Korean as a foreign language (KFL). Each study includes three experiments: a movie judgment tasks, and two written acceptability judgment tanks---one with sentences and one with question-answer mini-dialogues. The EFL study tested 148 L2 learners of English in Korea and 42 native speakers of English. In the KFL study, the participants were 117 L2 learners of Korean in the U.S. and 64 native speakers of Korean. In the movie test, participants viewed an animation with one of the context types (animate, inanimate, and no agent) and read a passive/inchoative sentence describing the movie and then judge how well the sentence describes the movie. The sentence test investigated how well the participants know that by the agent-phrases (with an animate or inanimate agent) sound natural only with passives, not inchoatives, but that by itself-phrases sound natural with only inchoatives, not passives. The Q&A test examined whether passive and inchoative why-questions expect different types of answers (purpose, animate-cause, and inanimate-cause).Includes bibliographical references (leaves 242-247).Also available by subscription via World Wide Web275 leaves, bound 29 c
THE ACQUISITION AND INTERPRETATION OF ENGLISH LOCATIVE CONSTRUCTIONS BY NATIVE SPEAKERS OF KOREAN
Platelet Activation: The Mechanisms and Potential Biomarkers
Beyond hemostasis and thrombosis, an increasing number of studies indicate that platelets play an integral role in intercellular communication, mediating inflammatory and immunomodulatory activities. Our knowledge about how platelets modulate inflammatory and immunity has greatly improved in recent years. In this review, we discuss recent advances in the pathways of platelet activation and potential application of platelet activation biomarkers to diagnosis and prediction of disease states
Crystal structure of calcium perchlorate anhydrate, Ca(ClO4)2, from laboratory powder X-ray diffraction data
The crystal structure of calcium perchlorate anhydrate was determined from laboratory X-ray powder diffraction data. The title compound was obtained by heating hydrated calcium perchlorate [Ca(ClO 4)2 ·xH2 O] at 623K in air for 12h. It crystallizes in the orthorhombic space group Pbca and is isotypic with Ca(AlD4)2. The asymmetric unit contains one Ca, two Cl and eight O sites, all on general sites (Wyckoff position 8c). The crystal structure consists of isolated ClO4 - tetrahedra and Ca2+ cations. The Ca2+ cation is coordinated by eight O atoms of eight symmetry-related ClO4 - tetrahedra within a distorted square-antiprismatic environment. © 2018 Lee et al.TRU
Downregulation of Poly(ADP-Ribose) Polymerase 1 by a Viral Processivity Factor Facilitates Lytic Replication of Gammaherpesvirus
Nuclear Factor I-C Regulates Stemness Genes and Proliferation of Stem Cells in Various Mineralized Tissue through Epithelial-Mesenchymal Interactions in Dental Epithelial Stem Cells
© 2022 Dong-Seol Lee et al.Tooth development includes numerous cell divisions and cell-cell interactions generating the stem cell niche. After an indefinite number of divisions, pluripotent cells differentiate into various types of cells. Nuclear factor I (NFI) transcription factors are known as crucial regulators in various organ development and stem cell biology. Among its members, nuclear factor I-C (NFI-C) has been reported to play an essential role in odontogenesis. Nfic knockout mice show malformation in all mineralized tissues, but it remains unclear which stage of development Nfic is involved in. We previously reported that Nfic induces the differentiation of ameloblast, odontoblast, and osteoblast. However, the question remains whether Nfic participates in the late stage of development, perpetuating the proliferation of stem cells. This study aimed to elucidate the underlying mechanism of NFI-C function in stem cells capable of forming hard tissues. Here, we demonstrate that Nfic regulates Sox2 and cell proliferation in diverse mineralized tissue stem cells such as dental epithelial stem cells (DESCs), dental pulp stem cells, and bone marrow stem cells, but not in fibroblasts. It was also involved in the expression of pluripotency genes Lin28 and NANOG. Especially in DESCs, Nfic regulates the proliferation of epithelial cells via epithelial-mesenchymal interactions, which are the Fgf8-Nfic-Sox2 pathway in epithelium and Nfic-Fgf10 in the mesenchyme. Moreover, Nfic slightly increased reprogramming efficiency in induced pluripotent stem cells of mineralized tissues, but not in soft tissues. In conclusion, these results suggest that Nfic is a crucial factor for maintaining the stem cell niche of mineralized tissues and provides a possibility for Nfic as an additional factor in improving reprogramming efficiency.N