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"Ito, Junji"
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Winning by hiding behind others: An analysis of speed skating data
by
Ichinose, Genki
,
Miyagawa, Daiki
,
Masuda, Naoki
in
Athletes
,
Athletic ability
,
Biology and Life Sciences
2020
In some athletic races, such as cycling and types of speed skating races, athletes have to complete a relatively long distance at a high speed in the presence of direct opponents. To win such a race, athletes are motivated to hide behind others to suppress energy consumption before a final moment of the race. This situation seems to produce a social dilemma: players want to hide behind others, whereas if a group of players attempts to do so, they may all lose to other players that overtake them. To support that speed skaters are involved in such a social dilemma, we analyzed video footage data for 14 mass start skating races to find that skaters that hid behind others to avoid air resistance for a long time before the final lap tended to win. Furthermore, the finish rank of the skaters in mass start races was independent of the record of the same skaters in time-trial races measured in the absence of direct opponents. The results suggest that how to strategically cope with a skater's dilemma may be a key determinant for winning long-distance and high-speed races with direct opponents.
Journal Article
Latency shortening with enhanced sparseness and responsiveness in V1 during active visual sensing
2022
In natural vision, neuronal responses to visual stimuli occur due to self-initiated eye movements. Here, we compare single-unit activity in the primary visual cortex (V1) of non-human primates to flashed natural scenes (passive vision condition) to when they freely explore the images by self-initiated eye movements (active vision condition). Active vision enhances the number of neurons responding, and the response latencies become shorter and less variable across neurons. The increased responsiveness and shortened latency during active vision were not explained by increased visual contrast. While the neuronal activities in all layers of V1 show enhanced responsiveness and shortened latency, a significant increase in lifetime sparseness during active vision is observed only in the supragranular layer. These findings demonstrate that the neuronal responses become more distinct in active vision than passive vision, interpreted as consequences of top-down predictive mechanisms.
Journal Article
Uterine artery embolization for postpartum and postabortion hemorrhage: a retrospective analysis of complications, subsequent fertility and pregnancy outcomes
2020
PurposeTo evaluate the impact of UAE for postpartum and postabortion hemorrhage on future infertility, especially in patients undergoing infertility treatment, along with angiographic endpoints.Materials and methodsSixty-two sessions performed emergent or prophylactic UAE for postpartum or postabortion hemorrhage between 2008 and 2017 were selected. Subsequent pregnancy outcomes and complications were investigated as primary outcomes. The cases were divided into two groups based on the presence of massive hemorrhage. The relationships between angiographic endpoints and complications were also evaluated as secondary outcomes.ResultsThe mean patient age was 34.1 ± 6.5 years. Fourteen of the 23 patients (60.9%) with desired fertility achieved pregnancy and 10 patients achieved live births (43.5%). In the patients during infertility treatment, three of the four patients had complications of severe adhesion after caesarean section or placenta accreta. In the group of patients with massive hemorrhage, the occurrence of uterine infection was significantly high (p = 0.014), but the angiographic endpoints were not significant, regardless of the occurrence of uterine infection.ConclusionIt was unnecessary to modify embolic endpoint according to seriousness of the hemorrhage. The pregnancy and live birth rates were acceptable, although patients undergoing infertility treatment had a higher rate of delivery complications.
Journal Article
The effect of arterial spin labeling MR angiography (ASL-MRA) in visualizing the branches of external carotid artery
2024
This study aimed to assess the performance of arterial-spin labeling MRA (ASL-MRA) for visualizing the external carotid artery (ECA) branches in comparison with time-of-flight MRA (TOF-MRA) and CT angiography (CTA). We retrospectively selected 31 consecutive patients, who underwent both MRAs and CTA, prior to the intra-arterial chemoradiotherapy (IACRT) for head and neck cancer. Four patients underwent IACRT bilaterally, so we analyzed 35 ECAs. Pseudo-continuous, three-dimensional ASL using a turbo field echo sequence was acquired. For the TOF-MRA and CTA, clinically used parameters were applied. Two observers evaluated each ECA branch with reference to the angiogram at the IACRT, using five-point scale, in consensus. Friedman test for multiple comparisons was applied. ASL-MRA and CTA better visualized the superior thyroid, lingual, facial, submental, transverse facial, and internal maxillary arteries (IMAs) better than TOF-MRA (
p
< 0.05). In addition, CTA was superior to ASL-MRA in visualizing only submental artery among these arteries (
p
= 0.0005). Alternatively, the ASL-MRA was superior for visualizing the middle meningeal artery (MMA) and IMA, compared to the CTA (
p
= 0.0001 and 0.0007, respectively). ASL-MRA was superior to the TOF-MRA and similar to the CTA in visualizing most of ECA branches. Furthermore, ASL-MRA can better visualize the periphery of MMA and IMA than CTA.
Journal Article
Distinct modes of top-down cognitive processing in the ventral visual cortex
2019
Top-down cognitive control leads to changes in the sensory processing of the brain. In visual perception such changes can take place in the ventral visual cortex altering the functional asymmetry in forward and backward connections. Here we used fixation-related evoked responses of EEG measurement and dynamic causal modeling to examine hierarchical forward-backward asymmetry, while twenty-six healthy adults performed cognitive tasks that require different types of top-down cognitive control (memorizing or searching visual objects embedded in a natural scene image). The generative model revealed an enhanced asymmetry toward forward connections during memorizing, whereas enhanced backward connections were found during searching. This task-dependent modulation of forward and backward connections suggests two distinct modes of top-down cognitive processing in cortical networks. The alteration in forward-backward asymmetry might underlie the functional role in the cognitive control of visual information processing.
•Fixation-related evoked responses during visual cognitive processes were examined.•Dynamic causal modeling estimated the generative model of the evoked responses.•Memorizing visual objects enhanced the strength of forward connections.•while searching a target object enhanced the strength of backward connections.
Journal Article
Concomitant radiotherapy and transarterial chemoembolization reduce skeletal-related events related to bone metastases from renal cell carcinoma
by
Toguchi Masafumi
,
Murayama Sadayuki
,
Maemoto Hitoshi
in
Anticancer properties
,
Bone cancer
,
Carboplatin
2020
ObjectivesThe purpose of this study was to compare the efficacy of radiotherapy (RT) combined with transcatheter arterial chemoembolization (TACE) with RT alone for the treatment of bone metastases from renal cell carcinoma (RCC).MethodsWe included in this retrospective study 25 RCC patients (28 bone metastases), who were treated with RT at our institution. Patients were divided into two groups: patients treated with RT alone (monotherapy group; n = 17) and those treated with RT combined with TACE (combined therapy group; n = 11). The administered median RT dose was 30 Gy in 10 fractions. Anti-cancer agents used in TACE were cisplatin (median dose, 50 mg) and carboplatin (median dose, 240 mg) for patients with reduced renal function. We evaluated the objective response, post-RT-skeletal-related event (PR-SRE)–free rate, and adverse events associated with treatment for each group.ResultsThe objective response rates for bone metastases in the monotherapy and combined therapy groups were 33% and 82%, respectively (p = 0.009). The 2-year PR-SRE-free rate in the monotherapy and combined therapy groups was 41.8% and 100%, respectively (p = 0.009). The objective response and PR-SRE-free rates were significantly superior in the combined therapy than in the monotherapy group. There were no significant differences in adverse events or survival between the two groups.ConclusionRT combined with TACE is a promising treatment for bone metastases from RCC, as it results in higher objective response, and PR-SRE-free rates compared with RT alone.Key Points• Skeletal-related events (SREs) are common in patients with bone metastases from renal cell carcinoma (RCC).• Radiotherapy (RT) provides pain relief in patients with bone metastases from RCC, but rarely achieves objective response.• Combination of RT with transcatheter arterial chemoembolization results in higher objective response and post-RT-SRE-free rates compared with RT alone and is a promising treatment for bone metastases from RCC, as it.
Journal Article
Immunogenicity of SARS-CoV-2 mRNA intramuscular vaccination in patients with muscular disorders
2023
Little clinical data is available on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients with muscular disorders (MDs). The immunogenicity of SARS-CoV-2 vaccines against MDs, in particular, remains unknown. Thus, this study aimed to confirm the immunogenicity and safety of the SARS-CoV-2 vaccine against MDs.
All participants were vaccinated with two doses of mRNA vaccines (BNT162b2, Pfizer-BioNTech). The serum samples were collected from each patient on the day of second dose of vaccination, and then, consecutively, after one month, three months, and six months. Anti-SARS-CoV-2 IgG levels were determined using the Abbott SARS-CoV-2 IgG II Quant assay.
We evaluated 75 individuals, including 42 patients with MDs and 33 patients with non-muscular disorders (non-MDs). Non-MD patients primarily include those with severe motor and intellectual disabilities. The median age of the patients was 32 years (range 12-64 years). After one and three months following the second immunization, patients with MDs had lower antibody responses. Furthermore, three months following the second immunization, the proportion of high responders among patients with MDs decreased significantly compared to that among patients without MDs (
-value of less than 0.01). No serious adverse events were observed in patients with or without MDs.
Intensity and latency of antibody response were suppressed in patients with MDs. Although MDs may be a key contributor in predicting the antibody response to SARS-CoV-2 vaccination, SARS-CoV-2 immunization in MDs needs extensive research.
Journal Article
Comparison of single- and multi-isocenter planning with Dynamic WaveArc for multiple brain metastases
2025
Dynamic WaveArc (DWA) is a technique used for continuous, non-coplanar volumetric-modulated arc therapy on the Vero4DRT platform. This study aimed to evaluate the application of single-isocenter DWA (SI-DWA) for treating multiple brain metastases by comparing dose distribution and irradiation time with multi-isocenter DWA (MI-DWA) through retrospective treatment planning. Treatment plans were developed for SI-DWA and MI-DWA in 14 cases with 3–5 brain metastases. Parameters assessed included target dose indices, such as conformity index (CI) of the planning target volume (PTV), volumes of normal brain excluding gross tumor volumes (GTVs) receiving a single dose equivalent of 14 Gy (V14), V30%, V20%, V10%, volumes of normal brain, including GTVs receiving a single dose equivalent of 12 Gy (V12), D2% for other organs at risk, and beam-on time. SI-DWA showed inferior CI, V14, and V12 values for lesions with PTV volumes <1 cc, whereas it performed equivalently to MI-DWA for lesions with PTV volumes ≥1 cc. SI-DWA resulted in higher volumes of normal brain receiving low doses compared to MI-DWA. SI-DWA exhibited significantly shorter beam-on times than MI-DWA. In conclusion, SI-DWA is an effective method for treating multiple brain metastases with PTV volumes ≥1 cc, offering an index of radiation-induced brain necrosis comparable with MI-DWA while allowing for shorter irradiation times.
Journal Article
Switch from ambient to focal processing mode explains the dynamics of free viewing eye movements
2017
Previous studies have reported that humans employ ambient and focal modes of visual exploration while they freely view natural scenes. These two modes have been characterized based on eye movement parameters such as saccade amplitude and fixation duration, but not by any visual features of the viewed scenes. Here we propose a new characterization of eye movements during free viewing based on how eyes are moved from and to objects in a visual scene. We applied this characterization to data obtained from freely-viewing macaque monkeys. We show that the analysis based on this characterization gives a direct indication of a behavioral shift from ambient to focal processing mode along the course of free viewing exploration. We further propose a stochastic model of saccade sequence generation incorporating a switch between the two processing modes, which quantitatively reproduces the behavioral features observed in the data.
Journal Article
Revealing Whole-Brain Causality Networks During Guided Visual Searching
2022
In our daily lives, we use eye movements to actively sample visual information from our environment (‘active vision’). However, little is known about how the underlying mechanisms are affected by goal-directed behavior. In a study of 31 participants, magnetoencephalography was combined with eye-tracking technology to investigate how interregional interactions in the brain change when engaged in two distinct forms of active vision: freely viewing natural images or performing a guided visual search. Regions of interest with significant fixation-related evoked activity were identified with spatiotemporal cluster permutation testing. Using generalized partial directed coherence, we show that, in response to fixation onset, a bilateral cluster consisting of four regions (posterior insula, transverse temporal gyrus, superior temporal gyrus, and supramarginal gyrus) formed a highly-connected network during free viewing. A comparable network also emerged in the right hemisphere during the search task, with the right supramarginal gyrus acting as a central node for information exchange. The results suggest that all four regions are vital to visual processing and guiding attention. Furthermore, the right supramarginal gyrus was the only region where activity during fixations on the search target was significantly negatively correlated with search response times. Based on our findings, we hypothesize that, following a fixation, the right supramarginal gyrus supplies the right supplementary eye field with new information to update the priority map guiding the eye movements during the search task.
Journal Article