43 research outputs found

    "Exaggerated Death of Distance: Revisiting Distance Effects on Regional Price Dispersions"

    Get PDF
    This paper empirically establishes the significant roles of transport costs in price dispersions across regions. We identify and estimate the iceberg-type distance-elastic transport costs as a parameter of a structural model of cross-regional price differentials featuring product delivery decisions. Utilizing a data set of wholesale prices and product delivery patterns of agricultural products in Japan, our structural estimation approach finds large distance elasticities of the transport costs. The result confirms that geographical barriers are an economically significant contributor to the failures of the law of one price.

    Exaggerated Death of Distance: Revisiting Distance Effects on Regional Price Dispersions

    Get PDF
    This paper empirically establishes the signicant roles of transport costs in price dispersions across regions. We identify and estimate the iceberg-type distance-elastic transport costs as a parameter of a structural model of cross-regional price dierentials featuring product delivery decisions. Utilizing a data set of wholesale prices and product delivery patterns of agricultural products in Japan, our structural estimation approach nds large distance elasticities of the transport costs. The result conrms that geographical barriers are an economically signicant contributor to the failures of the law of one price.

    The Price of Distance : Pricing to Market, Producer Heterogeneity, and Geographic Barriers

    Get PDF
    Transport costs are generally attributable to price differentials across geographically separated re-gions. However, when using price differential data, the identification of distance-elastic transport costs depends on how producers handle transport costs and set prices in remote markets. To ad-dress this problem, we adopt a nonhomothetic preference framework with heterogeneous producers. We show that the presence of nonhomothetic preferences is important in causing producer hetero-geneity to alter individual pricing behavior depending on market conditions, a property absent in the constant elasticity of substitution heterogeneity framework. This also exhibits the property that producers do not fully pass on the increase in transport costs. By not accounting for these features, the distance elasticity of transport costs is underestimated. However, by incorporating these features in our model and using empirical analysis and microlevel data, we reveal that the distance effect is significantly large, suggesting that the price of geographic barriers for regional transportation is high

    Development of an epileptic seizure prediction algorithm using R–R intervals with self-attentive autoencoder

    Get PDF
    Epilepsy is a neurological disorder that may affect the autonomic nervous system (ANS) from 15 to 20 min before seizure onset, and disturbances of ANS affect R–R intervals (RRI) on an electrocardiogram (ECG). This study aims to develop a machine learning algorithm for predicting focal epileptic seizures by monitoring R–R interval (RRI) data in real time. The developed algorithm adopts a self-attentive autoencoder (SA-AE), which is a neural network for time-series data. The results of applying the developed seizure prediction algorithm to clinical data demonstrated that it functioned well in most patients; however, false positives (FPs) occurred in specific participants. In a future work, we will investigate the causes of FPs and optimize the developing seizure prediction algorithm to further improve performance using newly added clinical data

    Emerging roles of ARHGAP33 in intracellular trafficking of TrkB and pathophysiology of neuropsychiatric disorders

    Get PDF
    Intracellular trafficking of receptor proteins is essential for neurons to detect various extracellular factors during the formation and refinement of neural circuits. However, the precise mechanisms underlying the trafficking of neurotrophin receptors to synapses remain elusive. Here, we demonstrate that a brain-enriched sorting nexin, ARHGAP33, is a new type of regulator for the intracellular trafficking of TrkB, a high-affinity receptor for brain-derived neurotrophic factor. ARHGAP33 knockout (KO) mice exhibit reduced expression of synaptic TrkB, impaired spine development and neuropsychiatric disorder-related behavioural abnormalities. These deficits are rescued by specific pharmacological enhancement of TrkB signalling in ARHGAP33 KO mice. Mechanistically, ARHGAP33 interacts with SORT1 to cooperatively regulate TrkB trafficking. Human ARHGAP33 is associated with brain phenotypes and reduced SORT1 expression is found in patients with schizophrenia. We propose that ARHGAP33/SORT1-mediated TrkB trafficking is essential for synapse development and that the dysfunction of this mechanism may be a new molecular pathology of neuropsychiatric disorders

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

    Get PDF
    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

    The Price of Distance : Pricing to Market, Producer Heterogeneity, and Geographic Barriers

    No full text
    corecore