Abnormal structure and function of white matter in obsessive-compulsive disorder.

BACKGROUND: Abnormal structure and function of gray matter (GM) have been discovered in the cortico-striatal-thalamic-cortical (CSTC) circuit in obsessive-compulsive disorder (OCD). The GM structure and function may be influenced by the structure and function of the white matter (WM). Therefore, it is crucial to explore the characteristics of WM in OCD. METHODS: Diffusion tensor imaging and resting-state functional magnetic resonance imaging data of 52 patients with OCD and 39 healthy controls (HCs) were collected. The tract-based spatial statistics, amplitude of low-frequency fluctuations (ALFF), and structural-functional coupling approaches were utilized to explore the WM structure and function. Furthermore, the relationship between the abnormal WM structure and function and clinical symptoms of OCD was investigated using Pearson's correlation. Support vector machine was performed to evaluate whether patients with OCD could be identified with the changed WM structure and function. RESULTS: Compared to HCs, the lower fractional anisotropy (FA) values of four clusters including the superior corona radiata, anterior corona radiata, right superior longitudinal fasciculus, corpus callosum, left posterior corona radiata, fornix, and the right anterior limb of internal capsule, reduced ALFF/FA ratio in the left anterior thalamic radiation (ATR), and the decreased functional connectivity between the left ATR and the left dorsal lateral prefrontal cortex within CSTC circuit at rest were observed in OCD. The decreased ALFF/FA ratio in the left ATR negatively correlated with Yale-Brown Obsessive-Compulsive Scale obsessive thinking scores and Hamilton Anxiety Rating Scale scores in OCD. Furthermore, the features that combined the abnormal WM structure and function performed best in distinguishing OCD from HCs with the appropriate accuracy (0.80), sensitivity (0.82), as well as specificity (0.80). CONCLUSION: Current research discovered changed WM structure and function in OCD. Furthermore, abnormal WM structural-functional coupling may lead to aberrant GM connectivity within the CSTC circuit at rest in OCD. TRIAL REGISTRATION: Study on the mechanism of brain network in obsessive-compulsive disorder with multi-model magnetic resonance imaging (ChiCTR-COC-17013301).

Two multimodal neuroimaging subtypes of obsessive-compulsive disorder disclosed by semi-supervised machine learning.

BACKGROUND: Obsessive-compulsive disorder (OCD) is a highly heterogeneous mental condition with a diverse symptom. Existing studies classified OCD on the basis of conventional phenomenology-based taxonomy ignoring the fact that the same subtype identified in accordance with clinical symptom may have different mechanisms and treatment responses. METHODS: This research involved 50 medicine-free patients with OCD and 50 matched healthy controls (HCs). All the participants were subjected to structural and functional magnetic resonance imaging (MRI). Voxel-based morphometry (VBM) and amplitude of low frequency fluctuation (ALFF) were used to evaluate gray matter volume (GMV) and spontaneous neuronal activities at rest respectively. Similarity network fusion (SNF) was utilized to integrate GMVs and spontaneous neuronal activities, and heterogeneity by discriminant analysis was applied to characterise OCD subtypes. RESULTS: Two OCD subtypes were identified: Subtype 1 exhibited decreased GMVs (i.e., left inferior temporal gyrus, right supplementary motor area and right lingual gyrus) and increased ALFF value (i.e., right orbitofrontal cortex), whereas subtype 2 exhibited increased GMVs (i.e., left cuneus, right precentral gyrus, left postcentral gyrus and left hippocampus) and decreased ALFF value (i.e., right caudate nucleus). Furthermore, the altered GMVs was negatively correlated with abnormal ALFF values in both subtype 1 and 2. LIMITATIONS: This study requires further validation via a larger, independent dataset and should consider the potential influences of psychotropic medication on OCD patients' brain activities. CONCLUSIONS: Results revealed two reproducible subtypes of OCD based on underlying multimodal neuroimaging and provided new perspectives on the classification of OCD.

The Effects of General Listening Anxiety and Listening Test Anxiety on Self-Perceived Listening Performance Among Chinese English Learners.

Purpose: This research seeks to conceptualize foreign language listening anxiety (FLLA) and provide its measurement, and further explore the influences of FLLA on self-perceived listening performance. Methods: In Study 1, semi-structured interviews explored FLLA-arousal situations. Follow-up reliability and validity tests for the newly-developed scale were testified. In Study 2, structural equation modeling explored the relationship between FLLA and self-perceived performance, which was followed by the comparison of the effects of different types of FLLA on self-perceived performance between English and non-English major students. Results: The componential factors of FLLA included two factors, namely general listening anxiety and listening test anxiety, and general listening anxiety was represented by FLLA in classroom, daily usage, and media learning. The results also showed that listening test anxiety negatively affected self-perceived performance; general listening anxiety positively affected listening test anxiety but did not affect self-perceived performance, and listening test anxiety played a full mediation role. Moreover, findings revealed that non-English major students' general listening anxiety was higher than that of English major students. However, the multi-group analysis showed that these two groups did not differ in the effect of general listening anxiety on listening test anxiety, and in the effects of listening anxieties on self-perceived performance. For the two groups, the mechanism of anxiety-and-performance relationship was consistent. Conclusion: The results of this research have expanded the knowledge of listening anxiety by distinguishing general listening anxiety from listening test anxiety. Moreover, by testifying the mediator of listening test anxiety, this research deepened the understanding of the effects of different types of FLLA on self-perceived listening performance and the intensity differences of listening anxieties in English and non-English majors. Furthermore, the research has contributed to the literature on FLLA research based on Complex Dynamic Systems Theory, and has practical pedagogical implications for future studies.

Chinese University English Teachers' Professional Learning through Academic Reading on Social Media-A Mixed-Methods Approach.

Teachers' professional learning on social media has received growing attention recently, but research into teachers' academic engagement on social media remains limited. This study aimed to examine what factors motivated university English teachers to engage with academic reading on social media. The determinants of academic reading on social media were identified by semi-structured interviews, which were further validated by quantitative investigation. The results showed that participants' perception of values of content knowledge, pedagogical content knowledge, and students' participation in the classroom affected their intentions toward commitment to academic reading on social media. Additionally, the results revealed that perceived value of pedagogical content knowledge mediated the relationship between perceived value of content knowledge and participants' intentions toward academic reading on social media while also mediating the relationship between perceived value of students' participation in the classroom and the participants' intentions toward academic reading on social media. These findings yield implications for the professional development of university teachers and the development of pedagogical content knowledge.

A Systematic Review of Foreign Language Listening Anxiety: Focus on the Theoretical Definitions and Measurements.

A considerable amount of research on foreign language (FL) listening anxiety has emerged since 1986, yet a lack of sufficient attention on the conceptual definitions of FL listening anxiety and inappropriate employment of instruments to measure FL listening anxiety cause confusion in the research to a certain extent. This study presents a systematic review of 35 years of FL listening anxiety research. After initially searching 2,172 studies in 7 databases, 76 studies were identified for in-depth analysis. The results verified that the definitions of FL listening anxiety can be categorized into psychological, social, and situation-specific approaches, but the measure of FL listening anxiety was not only examined under these three approaches, but also additionally examined by sources of anxiety, learner characteristics, FL listening ability, and physiological factors. The results also showed that the definition of FL listening anxiety was not clear-cut nor that the measure was accurate, and to a great extent, the measure and the definition were inconsistent. This inconsistency can attribute to conceptual fuzziness in theoretical defining and casual utilization of scales without justification or explanation. We argue that future research needs to provide a tighter link between a more precise definition based on different situations and a valid measure of FL listening anxiety.

[Characteristics, Source Analysis, and Health Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) Pollution in Marine Organisms from Estuaries of Changhua River in Hainan Province].

To assess the contamination by polycyclic aromatic hydrocarbons (PAHs) in organisms in the estuary of Changhua River in Hainan, we determined the content of 16 priority PAHs by gas chromatography and mass spectrometry (GC-MS). The composition, source, and potential edible risk of PAHs were studied. The results showed that the total PAHs of demersal fish (wet weight, same below), crustaceans, and pelagic fish were 5.52-787.98, 12.18-154.64, and 10.20-199.79 ng·g-1, respectively, and the average contents were 83.21, 64.72, and 89.48 ng·g-1, respectively. There were some differences in the content of PAHs in various organisms. The average content followed the order of pelagic fish > demersal fish > crustaceans. Compared with other areas in the country and abroad, the content of marine organisms'PAHs in the estuary of the Changhua River was above the medium level. The result of isomer characteristic ratio showed that the PAHs of 33 organisms mainly came from the combustion sources (petroleum combustion and biomass combustion) and petroleum sources. Moreover, demersal fish were greatly affected by combustion sources, while pelagic fish were greatly affected by petroleum sources. Human risk assessment indicated that the content of benzopyrene (BaP) was within the limits set by the European Union. Most of the organisms in the estuary of Changhua River were within the safe range of consumption, but the long-term consumption of these seafoods may pose a potential health risk (1.0×10-5≤ILCR<1.0×10-4).

Effects of vehicle gap changes on fuel economy and emission performance of the traffic flow in the ACC strategy.

This paper focuses on the effects of vehicle gap changes on fuel and emission performance of the simulated traffic flow in the adaptive cruise control (ACC) strategy. Firstly, the close correlation of vehicle gap changes and the host car's behaviors was explored with the measured car-following data. Secondly, the correlation between the host car's velocity and vehicle gap changes with different memory steps was also explored to develop the nth car's optimal velocity function. Thirdly, a microscopic traffic simulation program was created for analyzing the traffic flow evolution process and approximately estimating the fuel consumptions and exhaust emissions. As a result, it was seen that vehicle gap changes with memory significantly affect fuel economy and emission performance of the simulated traffic flow in the ACC strategy, which can result in low fuel consumptions and exhaust emissions. This study is an incremental step forward for designing the control strategy of the ACC system.