20 research outputs found

    SHEAR ZONE DEVELOPMENT AND FRICTIONAL INSTABILITY OF FAULT GOUGE

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    ABSTRACT: Earthquakes are typical phenomena of frictional slip of geomaterials in nature. To evaluate slip instability, shear development in a gouge layer or fault material has been investigated. However, the quantitative relationship between slip instability and shear development has not been revealed because of difficulty in quantitative observation of microstructures under high pressure. Hence, we aim to describe shear development in a gouge layer energetically, and discuss the relation between shear development and slip instability. To this end, we calculated shear angles by utilizing experimental data of gouge. As a result, this study reveals that shear bands in a gouge layer develop at lower angles or almost parallel to rock-gouge boundaries toward the occurrence of unstable slip, particularly under low confining pressure. Additionally, variation in Riedel shear angles throughout gouge layers depends on confining pressures: Under low confining pressures, heterogeneous localized shears trigger voluntary increase in strain. On the other hand, under a high confining pressure, gouge layers deform homogeneously, and the whole of samples slips dynamically. Clarification of shear development of geomaterials is useful for evaluating the occurrence of frictional slip such as earthquakes and slope failures

    Introduction pathways and evolutionary mechanisms of alien species of Lolium spreading across sandy coasts in Japan

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    1. Estimating the role of specific processes in the spread of alien species necessitates the determination of introduction pathways and source populations of invaded areas. Alien grasses in the genus Lolium that have extensively invaded Japan provide a unique opportunity to estimate the expansion process through direct comparison between source and naturalised populations because the introduction pathways, contaminants in grain commodities and commercial cultivars for fodder crops or revegetation materials are well-known. Therefore, by directly comparing source and naturalised populations, we estimated the introduction pathways and whether adaptative evolution occurred in Lolium species on sandy coasts in Japan. 2. Lolium individuals sampled from naturalised populations in croplands, seaports, and sandy coasts were compared with those from two introduction sources for morphological and genetic variations based on a genome-wide single nucleotide polymorphism analysis and a common garden experiment. Furthermore, we conducted a reciprocal transplant experiment between cropland and sandy coast. 3. Populations naturalised in croplands were closely related to the cultivars, whereas those naturalised in seaports and sandy coasts were associated with contaminants. These results indicate that the cropland and sandy coast populations are derived from cultivars and contaminants, respectively. In addition, asymmetric gene flow from cropland populations to sandy coast populations was observed. The reciprocal transplant experiment clearly demonstrated the home site advantage; populations derived from croplands yielded higher floret numbers than those derived from other habitats at the cropland site; sandy coast populations had higher survival rates than those from croplands at the coastal site. Port populations exhibited a similar tendency as sandy coast populations, indicating that contaminants may be originally adapted to salty and dry environments, such as that in sandy coasts. The flowering phenology in the sandy coast populations evolved in the late flowering; therefore, late flowering alleles may have been transferred from cropland populations to sandy coast populations. 4. Synthesis. We demonstrated that two congeneric species with different ecological characteristics were introduced through multiple introduction pathways and spread across different habitats. A direct comparison between source and naturalised populations can considerably elucidate the patterns and processes of biological invasions

    A sporadic case of CTLA4 haploinsufficiency manifesting as Epstein–Barr virus-positive diffuse large B-cell lymphoma

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    Cytotoxic T-lymphocyte-associated antigen 4 (CTLA4) is a coinhibitory receptor that plays an essential role in maintaining immune system homeostasis by suppressing T-cell activation. We report a sporadic case of CTLA4 haploinsufficiency in a patient with Epstein-Barr virus-positive diffuse large B-cell lymphoma and subsequent benign lymphadenopathy. A missense mutation in exon 2 of the CTLA4 gene (c.251T>C, p.V84A) was found in the patient's peripheral blood and buccal cell DNA, but not in her parents' DNA. CTLA4 expression decreased in the peripheral regulatory T cells upon stimulation, whereas CTLA4 and PD-1-positive T cell subsets increased, possibly to compensate for the defective CTLA4 function. This case suggests that some adult lymphoma patients with no remarkable medical history have primary immune disorder. As immune-targeted therapies are now widely used for the treatment of malignancies, it is increasingly important to recognize the underlying primary immune disorders to properly manage the disease and avoid unexpected complications of immunotherapies

    SLAM family member 8 is expressed in and enhances the growth of anaplastic large cell lymphoma

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    Signaling lymphocytic activation molecule family member 8 (SLAMF8)B-lymphocyte activator macrophage expressed/CD353 is a member of the CD2 family. SLAMF8 suppresses macrophage function but enhances the growth of neoplastic mast cells via SHP-2. In this study, we found that some anaplastic large cell lymphoma (ALCL) samples were immunohistochemically positive for SLAMF8. However, we found no significant differences between SLAMF8-positive and SLAMF8-negative ALCL samples with respect to age, gender, site, or prognosis. We also identified SLAMF8 expression in ALCL cell lines, Karpas299, and SU-DHL-1. SLAMF8 knockdown decreased the activation of SHP-2 and the growth of these cell lines, and increased the apoptosis of these cell lines. In addition, we observed the interaction between SLAMF8 and SHP-2 in these cell lines using the DuoLink in situ kit. Taken together, these results suggest that SLAMF8 may enhance the growth of ALCL via SHP-2 interaction

    Elucidating the genetic architecture of reproductive ageing in the Japanese population.

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    Population studies elucidating the genetic architecture of reproductive ageing have been largely limited to European ancestries, restricting the generalizability of the findings and overlooking possible key genes poorly captured by common European genetic variation. Here, we report 26 loci (all P < 5 × 10-8) for reproductive ageing, i.e. puberty timing or age at menopause, in a non-European population (up to 67,029 women of Japanese ancestry). Highlighted genes for menopause include GNRH1, which supports a primary, rather than passive, role for hypothalamic-pituitary GnRH signalling in the timing of menopause. For puberty timing, we demonstrate an aetiological role for receptor-like protein tyrosine phosphatases by combining evidence across population genetics and pre- and peri-pubertal changes in hypothalamic gene expression in rodent and primate models. Furthermore, our findings demonstrate widespread differences in allele frequencies and effect estimates between Japanese and European associated variants, highlighting the benefits and challenges of large-scale trans-ethnic approaches

    Machine learning models for measuring stomatal aperture from Arabidopsis thaliana leaf images captured by a portable stomatal imaging device

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    &lt;p&gt;Sample images, notebook, and machine learning model weights for device images of the following articles&lt;/p&gt; &lt;p&gt;- &lt;a href="https://doi.org/10.1093/pcp/pcad018"&gt;https://doi.org/10.1093/pcp/pcad018&lt;/a&gt;&nbsp;(Title: Image-Based Quantification of&nbsp;&lt;em&gt;Arabidopsis thaliana&lt;/em&gt;&nbsp;Stomatal Aperture from Leaf Images)&lt;/p&gt; &lt;p&gt;- submitted paper (Title: Direct observation and automated measurement of stomatal responses to &lt;em&gt;Pseudomonas syringae&lt;/em&gt; pv. &lt;em&gt;tomato&lt;/em&gt; DC3000 in &lt;em&gt;Arabidopsis thaliana&lt;/em&gt;)&lt;/p&gt

    Monitoring the outcomes of non‐pharmacological treatments for cognitive impairment using magnetoencephalography: A case series

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    Key Clinical Message Cognitive impairment associated dementia is treatable non‐pharmacologically. Monitoring tools are important to provide proper treatment. The present study showed that the resting‐state brain activity measured using magnetoencephalography reflects their outcomes and captures clinical impressions better than neuropsychological assessments, which have inherent limitations such as the practice effect. Abstract Mild cognitive impairment (MCI) is a prodromal phase of dementia caused by brain diseases. Non‐pharmacological treatments are sometimes effective in improving patient's cognition and quality of life. To provide better treatments, monitoring the treatment outcomes, which is done using neuropsychological assessments, is important. However, these assessments have inherent limitations, such as practice effects. Therefore, complementary assessments are anticipated. Magnetoencephalography (MEG) is a neuroimaging technique that is sensitive to changes in brain activity associated with cognitive impairment. It represents the state of brain activity in terms of MEG spectral parameters associated with neuropsychological assessment scores. MEG spectral parameters could reasonably be used to monitor treatment outcomes without the aforementioned limitations. However, few published longitudinal reports have assessed MEG spectral parameters during the non‐pharmacological treatment period for cognitive impairment associated with dementia. In this study, we retrospectively examined the clinical records of two patients with MCI. Changes in neuropsychological assessment scores and MEG spectral parameters were qualitatively evaluated along with the patients' conditions, as described in the medical records during non‐pharmacological treatments provided for more than 2 years. The changes in neuropsychological assessment scores and MEG spectral parameters showed comparable trends, with some discrepancies. Changes in MEG spectral parameters were more consistent with the subjective reports from caregivers and medical staff in the medical records. Our results suggest that MEG is a promising tool for monitoring patient conditions during treatment
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