Biology subjects

Fukui, H.

Publications and source records attributed to Fukui, H..

7 recordsLinked to original sources

bioRxiv2026

Mapping human-macaque encounter potential by integrating visitor-use and macaque-use intensity in Kamikochi, Japan

Managing visitor-wildlife interactions in high-use protected areas requires identifying not only where visitors concentrate but also where visitor use overlaps with wildlife space use. We estimated relative human- macaque encounter potential in Kamikochi, Chubu Sangaku National Park, Japan, where Japanese macaques (Macaca fuscata) and visitors use the same frontcountry landscape. We integrated Mobile Spatial Statistics derived from mobile phone network data, trail-camera counts, and direct-follow location data from macaques along a frontcountry-backcountry gradient. Broad-scale 500-m grid estimates of daytime visitor presence for the 2023 and 2024 open seasons were allocated to 50-m trail sections and adjusted using counts from 10 trail cameras. Automated video counts based on YOLO11 and ByteTrack showed high agreement with manual counts of 100 validation videos (MAE = 0.10 persons/video, MAPE = 1.26%, exact agreement rate = 92.0%). Visitor-use and macaque-use data were converted into kernel density surfaces, and encounter potential was calculated as their normalized product. High encounter potential was concentrated in the central frontcountry: 87.1% of areas with index values [≥] 0.9 fell within the frontcountry and 12.9% within the backcountry. Areas with high visitor use or high macaque use alone did not necessarily show high encounter potential when the two distributions were spatially offset. These results show that spatial overlap provides management information not captured by visitor counts alone. Relative encounter potential can help prioritize patrols, visitor messaging, viewing management, and other interventions in protected areas where wildlife does not consistently avoid heavily used visitor spaces.

zoology↗

bioRxiv2026

Identity-state expression and switching in co-conscious dissociative identity disorder: a non-traumatic proof-of-concept fMRI study

Dissociative identity disorder (DID) remains debated because identity-state phenomena are privately experienced and may be attributed to suggestion, simulation or role enactment. Most neuroimaging studies rely on symptom provocation or traumatic recall, which complicates interpretation and is poorly suited to co-conscious presentations where simultaneous awareness should make state differences hardest to detect. We applied Identity-State Characterization and Analysis (ID-SCAN), a non-traumatic, identity-cued functional magnetic resonance imaging protocol, to a DSM-5-diagnosed woman with persistent co-consciousness between Adult and Adolescent identity-states. One task used identical insect images that evoked opposite preferences across identity-states; the other used trait judgments about self, the other identity-state and a shared intimate other. Analyses combined Bayesian single-case general linear modelling, generalized psychophysiological interaction connectivity and searchlight representational similarity analysis. Identity-instruction cue epochs were pooled across tasks to assess switch direction. The same insect stimuli engaged different valuation-related configurations across identity-states: Adolescent-selective effects centred on striato-thalamic regions, whereas Adult-selective effects extended to amygdala and orbitofrontal/medial prefrontal cortex, with distinct task-evoked coupling. Adult-as-self and Adolescent-as-self occupied separable positions within canonical self-referential regions. Cue-locked activity differed by switch direction across tasks, with larger reconfiguration when switching to Adult (mean between-cluster beta separation 4.30 versus 0.85; permutation p = 0.0001). Cross-task overlap localized a limited shared task-related substrate mainly to posterior visual and dorsal parietal cortex. Even under persistent co-consciousness and without trauma provocation, identity-state expression and switching showed convergent within-person neural signatures. The findings support non-traumatic mechanistic phenotyping of dissociative presentations and motivate cohort and longitudinal studies, including treatment-tracking work.

neuroscience↗

bioRxiv2026

Degree heating weeks fail to reach alert thresholds yet coral bleaching is widespread: structural insensitivity of anomaly-based metrics across Japan's latitudinal gradient

1.1Degree Heating Weeks (DHW) is the standard metric for global coral bleaching prediction, yet its performance varies markedly across regions for structurally unexplained reasons. We analyse five years (2020-2024) of standardised bleaching surveys from Japans Monitoring Site 1000 program (26 sites, 113 site-years; balanced panel n = 105) across a 24-35{degrees}N latitudinal gradient to diagnose why DHW fails in subtropical waters. Only 4 of 113 site-years (3.5%) reached the DHW [≥] 4 alert threshold, while bleaching (>0%) was recorded in 65 site-years (57.5%). DHW sensitivity for detecting any bleaching was 6.2%. A simple absolute-temperature metric (days with SST [≥] 30{degrees}C) significantly outperformed DHW in discriminating [≥]50% bleaching (AUC = 0.926 vs 0.667, {Delta}AUC = 0.260, 95% CI [0.154, 0.355], p < 0.001), with the largest gap at low latitudes ({Delta}AUC = 0.293, p < 0.001). The Maximum Monthly Mean (MMM) was strongly correlated with latitude (r = -0.914), compressing the thermal gap available for HotSpot accumulation at low-latitude sites and eliminating HotSpot events at high-latitude sites. This structural insensitivity -- arising from the anomaly-based design of DHW rather than from threshold miscalibration -- operated through two distinct mechanisms across the latitudinal gradient. At low latitudes, where MMM approaches 30{degrees}C, HotSpot signals were compressed below detection thresholds despite widespread bleaching; at high latitudes, SST rarely exceeded MMM, rendering HotSpot events absent altogether. These findings demonstrate that DHWs standard alert framework is structurally non-functional across Japans coral monitoring network and that regional assessment requires metrics independent of the MMM-relative anomaly architecture.

ecology↗

bioRxiv2026

Coral bleaching as state transition: bimodal prevalence and response-definition dependence of thermal stress metrics across Japan's Monitoring Site 1000 network

Coral bleaching is conventionally modelled as a continuous response to cumulative thermal stress, yet the distributional structure of site-level bleaching prevalence has rarely been examined. Here we analyse five years (fiscal years 2020-2024) of standardised bleaching surveys from Japans Monitoring Site 1000 program, encompassing 2,288 observations across 585 survey points at 26 sites in the Ryukyu Archipelago and adjacent waters. We document three principal findings. First, bleaching prevalence is bimodally distributed in all five years: the intermediate range (20-80%) remains stable at 21-27% of observations, while inter-annual variation is driven by redistribution between low and high domains -- confirmed by Hartigans dip test (all p < 0.001) and beta mixture modelling ({Delta}BIC = 9.0-113.9). Second, the 2022 and 2024 bleaching events are qualitatively distinct: 2022 was a partial mass bleaching (positively skewed, selective), while 2024 was comprehensive (symmetric, median 60.0%). Third, a simple threshold metric (days above 30{degrees}C) outperformed Degree Heating Weeks in discriminating bleaching across all severity levels (GEE-based AUC: 0.877 vs 0.624 at [≥]50% prevalence, p < 0.001; 0.830 vs 0.633 at >0%, p = 0.007), indicating that metric structure and the ecological severity threshold defining the outcome are inseparable design considerations.

ecology↗

bioRxiv2025

Endothelial-zippering proceeds by sensing heartbeat-driven force through Cadherin-6 during heart-vessel connection in zebrafish

The connection between the heart and great vessels established during embryogenesis is essential for circulation. However, how great veins adhere to the endocardium lining the inside lumen of the beating heart remains unknown. Here, using zebrafish, we demonstrate that the endocardium and great veins are sealed in a zipper-closing manner outside the beating heart. The gradual elongation of the endocardium, driven by convergent extension, organized this adhesion by pulling venous ECs along the anterior-posterior axis. Time-specific manipulation of the heart rate revealed that this endocardial elongation proceeds against heartbeat-driven force. From time-lapse imaging of adherens junctions, which would counterbalance mechanical forces, we found a specific contribution of Cadherin-6 instead of Cadherin-5 in sensing endocardium-specific mechanical force. This specificity was confirmed by the depletion of Cadherin-6 that caused endocardium deformation. Altogether, we propose Cadherin-6 mediated EC-zippering as a novel mechanism that updates the understanding of Cadherin usage in dynamic morphogenesis.

developmental biology↗

bioRxiv2024

Sympathetic Nervous System Overactivation Induces Colonic Eosinophil-Associated Microinflammation and Contributes to the Pathogenesis of Irritable Bowel Syndrome

ObjectiveMucosal microinflammation is a characteristic clinical manifestation of irritable bowel syndrome (IBS), and its symptoms are often triggered by psychological stress. In the present study, we aimed to investigate the impact of early life stress-associated dysfunction of the sympathetic nervous system (SNS) on mucosal immune changes in the gastrointestinal tract (GI) and its contribution to IBS pathogenesis. DesignWe utilised a traditional animal model of IBS with maternal separation (MS) and evaluated colorectal hypersensitivity, immune alterations, and SNS activity in adult rats with MS. We conducted a series of experiments to manipulate peripheral SNS activity pharmacologically and chemogenetically to explore the interaction between SNS activity and GI events. ResultsThe MS-induced IBS model exhibited visceral hypersensitivity and eosinophilic infiltration in the colonic mucosa, along with SNS overactivation. Degeneration of the SNS using 6-OHDA neurotoxin decreased eosinophil infiltration and visceral hypersensitivity in the MS model. Notably, specific chemogenetic activation of the peripheral SNS induced eosinophil infiltration in the intestinal mucosa through the noradrenergic signalling-mediated release of eotaxin-1 from mesenchymal cells. ConclusionThis study highlights the critical role of SNS overactivation in eotaxin-1-driven eosinophil infiltration in the colon, leading to the development of visceral hypersensitivity in IBS. The results provide important insights into the mechanistic links among increased sympathetic activity, mucosal microinflammation, and visceral hypersensitivity in individuals with IBS, suggesting potential therapeutic approaches. What is already known on this topicO_LIA subgroup of patients with irritable bowel syndrome (IBS) presents with microinflammation in the gastrointestinal tract (GI). C_LIO_LIEarly life stress is recognised as a major risk factor for the development of IBS in adulthood. C_LIO_LIOveractivation of the sympathetic nervous system (SNS) is frequently associated with IBS. C_LI What this study addsO_LIMaternal separation (MS) stress induces eosinophil-associated microinflammation in the colonic mucosa of adult rats. C_LIO_LIInhibition of SNS activity suppresses eosinophil infiltration and mitigates visceral hypersensitivity in the MS model. C_LIO_LINoradrenergic signalling within the peripheral sympathetic activation stimulates mesenchymal cells to release eotaxin-1, leading to substantial eosinophil-predominant immune alterations in the colon. C_LI How this study might affect research, practice, or policyO_LITreatment with fibroblast-derived eotaxin-1 and targeting eosinophil-associated microinflammation could be a potential strategy to alleviate visceral pain in patients with IBS. C_LIO_LIThe chemogenomic method specifically manipulates peripheral SNS and provides a valuable tool for future research. C_LI

neuroscience↗

bioRxiv2017

Hippo signaling restricts cells in the second heart field that differentiate into Islet-1-positive atrial cardiomyocytes

AbstractCardiac precursor cells (CPCs) in the first heart field (FHF) and the second heart field (SHF) present at both arterial and venous poles assemble to form a cardiac tube in zebrafish. Hippo kinase cascade is essential for proper heart formation; however, it remains elusive how Hippo signal contributes to early cardiac fate determination. We here demonstrate that mutants of large tumor suppressor kinase 1/2 (lats1/2) exhibited an increase in a SHF marker, Islet1 (Isl1)-positive and hand2 promoter-activated venous pole atrial cardiomyocytes (CMs) and that those showed expansion of the domain between between the anterior and the posterior lateral plate mesoderm. Consistently, TEAD-8 dependent transcription was activated in caudal region of the left ALPM cells that gave rise to the venous pole atrial CMs. Yap1/Wwtr1-promoted bmp2b expression was essential for Smad-regulated hand2 expression in the left ALPM, indicating that Hippo signaling restricts the SHF cells originating from the left ALPM that move toward the venous pole.

developmental biology↗