The p250GAP Gene Is Associated with Risk for Schizophrenia and Schizotypal Personality Traits

BACKGROUND: Hypofunction of the glutamate N-Methyl-d-aspartate (NMDA) receptor has been implicated in the pathophysiology of schizophrenia. p250GAP is a brain-enriched NMDA receptor-interacting RhoGAP. p250GAP is involved in spine morphology, and spine morphology has been shown to be altered in the post-mortem brains of patients with schizophrenia. Schizotypal personality disorder has a strong familial relationship with schizophrenia. Several susceptibility genes for schizophrenia have been related to schizotypal traits. METHODS: We first investigated the association of eight linkage disequilibrium-tagging single-nucleotide polymorphisms (SNPs) that cover the p250GAP gene with schizophrenia in a Japanese sample of 431 schizophrenia patients and 572 controls. We then investigated the impact of the risk genetic variant in the p250GAP gene on schizotypal personality traits in 180 healthy subjects using the Schizotypal Personality Questionnaire. RESULTS: We found a significant difference in genotype frequency between the patients and the controls in rs2298599 (χ(2) = 17.6, p = 0.00015). The minor A/A genotype frequency of rs2298599 was higher in the patients (18%) than in the controls (9%) (χ(2) = 15.5, p = 0.000083). Moreover, we found that subjects with the rs2298599 risk A/A genotype, compared with G allele carriers, had higher scores of schizotypal traits (F(1,178) = 4.08, p = 0.045), particularly the interpersonal factor (F(1,178) = 5.85, p = 0.017). DISCUSSION: These results suggest that a genetic variation in the p250GAP gene might increase susceptibility not only for schizophrenia but also for schizotypal personality traits. We concluded that the p250GAP gene might be a new candidate gene for susceptibility to schizophrenia

REM睡眠中の嗅覚刺激が夢の情動性に及ぼす影響 ―ニオイ知覚の個人差に基づく検討―

2021【要旨

Dominating factors influencing rapid meander shift and levee breaches caused by a record-breaking flood in the Otofuke River, Japan

The Otofuke River is a tributary of the Tokachi River, Hokkaido Japan, consisting of a channelized reach with a steep slope and a relatively large designed width. In August 2016, the river witnessed four major flooding events with a record-breaking discharge within a time span of 15 days. The Otofuke River originally had a straight channelized reach. However, because of a series of flooding events, the river promptly followed a sinusoidal path, damaging the riverbank embankments. The straight channelized reach of Otofuke River faced active erosion of both banks, leading to the formation of a meandering channel planform. This also led to levee breaches at the seven locations. In order to understand the mechanism of such a quick shift in river channel planform, we collected various field survey data and conducted computational analysis. We investigated the underlying processes by capturing the complex interactions between the rapid channel migration, unsteady discharge, and sediment transport. Field surveys including aerial photographs and images showed rapid formation of a meandering planform in the Otofuke River as a result of the typhoon on 31 August 2016. According to the maximum water level traces, bank erosion developed after the peak discharge. Numerical investigation revealed that alternate sandbars continuously developed and propagated downstream until the moment of peak discharge, and a significant accumulation of sediment subsequently started on the bars at the mid-channel during the flood falling stage. Such morphological processes led to strong flow deflections transversely toward the embankment that resulted in lateral channel shifting and levee breaches at a location where vegetation along the embankments had already disappeared

Dominating factors influencing rapid meander shift and levee breaches caused by a record-breaking flood in the Otofuke River, Japan

The Otofuke River is a tributary of the Tokachi River, Hokkaido Japan, consisting of a channelized reach with a steep slope and a relatively large designed width. In August 2016, the river witnessed four major flooding events with a record-breaking discharge within a time span of 15 days. The Otofuke River originally had a straight channelized reach. However, because of a series of flooding events, the river promptly followed a sinusoidal path, damaging the riverbank embankments. The straight channelized reach of Otofuke River faced active erosion of both banks, leading to the formation of a meandering channel planform. This also led to levee breaches at the seven locations. In order to understand the mechanism of such a quick shift in river channel planform, we collected various field survey data and conducted computational analysis. We investigated the underlying processes by capturing the complex interactions between the rapid channel migration, unsteady discharge, and sediment transport. Field surveys including aerial photographs and images showed rapid formation of a meandering planform in the Otofuke River as a result of the typhoon on 31 August 2016. According to the maximum water level traces, bank erosion developed after the peak discharge. Numerical investigation revealed that alternate sandbars continuously developed and propagated downstream until the moment of peak discharge, and a significant accumulation of sediment subsequently started on the bars at the mid-channel during the flood falling stage. Such morphological processes led to strong flow deflections transversely toward the embankment that resulted in lateral channel shifting and levee breaches at a location where vegetation along the embankments had already disappeared