63 research outputs found
A Neurorobotics Simulation of Autistic Behavior Induced by Unusual Sensory Precision
Recently, applying computational models developed in cognitive science to psychiatric disorders has been recognized as an essential approach for understanding cognitive mechanisms underlying psychiatric symptoms. Autism spectrum disorder is a neurodevelopmental disorder that is hypothesized to affect information processes in the brain involving the estimation of sensory precision (uncertainty), but the mechanism by which observed symptoms are generated from such abnormalities has not been thoroughly investigated. Using a humanoid robot controlled by a neural network using a precision-weighted prediction error minimization mechanism, it is suggested that both increased and decreased sensory precision could induce the behavioral rigidity characterized by resistance to change that is characteristic of autistic behavior. Specifically, decreased sensory precision caused any error signals to be disregarded, leading to invariability of the robot’s intention, while increased sensory precision caused an excessive response to error signals, leading to fluctuations and subsequent fixation of intention. The results may provide a system-level explanation of mechanisms underlying different types of behavioral rigidity in autism spectrum and other psychiatric disorders. In addition, our findings suggest that symptoms caused by decreased and increased sensory precision could be distinguishable by examining the internal experience of patients and neural activity coding prediction error signals in the biological brain
Risk factors for unsuccessful removal of central venous access ports implanted in the forearm of adult oncologic patients
Purpose: To evaluate the risk factors for unsuccessful removal of a central venous access port (CV port) implanted in the forearm of adult oncologic patients.
Materials and methods: This study included 97 adult oncologic patients (51 males, 46 females; age range, 30–88 years; mean age, 63.7 years) in whom removal of a CV port implanted in the forearm was attempted at our hospital between January 2015 and May 2021. Gender, age at removal, body mass index, and diagnosis were examined as patient characteristics; and indwelling period, indwelling side, and indication for removal were examined as factors associated with removal of a CV port. These variables were compared between successful and unsuccessful cases using univariate analysis. Then, multivariate analysis was performed to identify independent risk factors for unsuccessful removal of a CV port using variables with a significant difference in the univariate analysis. A receiver-operating characteristics (ROC) curve was drawn for significant risk factors in the multivariate analysis and the Youden index was used to determine the optimum cut-off value for predicting unsuccessful removal of a CV port.
Results: Removal of CV ports was successful in 79 cases (81.4%), but unsuccessful in 18 cases (18.6%) due to fixation of the catheter to the vessel wall. Multivariate logistic regression analysis showed that the indwelling period (odds ratio 1.048; 95% confidence interval 1.026–1.070; P 60 months had unsuccessful removal.
Conclusion: The indwelling period is an independent risk factor for unsuccessful removal of a CV port implanted in the forearm of adult oncologic patients, with a cut-off of 41 months
Emergence of sensory attenuation based upon the free-energy principle
The brain attenuates its responses to self-produced exteroceptions (e.g., we cannot tickle ourselves). Is this phenomenon, known as sensory attenuation, enabled innately, or acquired through learning? Here, our simulation study using a multimodal hierarchical recurrent neural network model, based on variational free-energy minimization, shows that a mechanism for sensory attenuation can develop through learning of two distinct types of sensorimotor experience, involving self-produced or externally produced exteroceptions. For each sensorimotor context, a particular free-energy state emerged through interaction between top-down prediction with precision and bottom-up sensory prediction error from each sensory area. The executive area in the network served as an information hub. Consequently, shifts between the two sensorimotor contexts triggered transitions from one free-energy state to another in the network via executive control, which caused shifts between attenuating and amplifying prediction-error-induced responses in the sensory areas. This study situates emergence of sensory attenuation (or self-other distinction) in development of distinct free-energy states in the dynamic hierarchical neural system
Percutaneous drainage of psoas and iliopsoas muscle abscesses with a one-step technique under real-time computed tomography fluoroscopic guidance
PURPOSE : To evaluate the utility and safety of drainage catheter installation for psoas/iliopsoas muscle abscesses using a one-step technique under the guidance of real-time computed tomography (CT) fluoroscopy. MATERIALS and METHODS : Ten psoas or iliopsoas muscle abscesses in 7 patients that were treated with percutaneous drainage were included in this study. All drainage procedures were carried out using a one-step technique under real-time CT fluoroscopic guidance. RESULTS : The drainage catheter insertion was performed successfully with the one-step technique in all lesions. Improvements in the patients’ symptoms and blood test results were seen after the drainage procedure in all cases. In addition, postoperative CT scans demonstrated that the abscesses had reduced in size or disappeared in all but one patient, who was transferred to another institution while the drainage catheter was still in place. No major complications were seen in any case. CONCLUSION : The one-step procedure is simple to perform. The percutaneous drainage of psoas or iliopsoas muscle abscesses with the one-step technique under real-time CT fluoroscopic guidance is accurate and safe. Moreover, compared with the two-step technique the one-step procedure results in a shorter drainage procedure and exposes the patient and operator to lower amounts of radiation
スマートフォン ト インターネット オ モチイタ トクシマ ケンリツ カイフ ビョウイン エンカク イリョウ シエン システム k-support ノ ドウニュウ
Because a specialist in general medical treatment lacked the Kaifu area of South Tokushima absolutely, we forced a limited doctor to many burdens and performed medical treatment while I always carried risks on my back for the disease except the specialty domain. A stroke specialist in particular is an absent medical depopulated area, and it is difficult to perform the rt-PA IV therapy that is a standard therapy for a stroke for the immediate nature period. Using remote video diagnosis treatment supporting system SYNAPSE ERm that was the smartphone application that FUJIFILM developed for the purpose of canceling these, we introduced smartphone and Tokushima Prefectural Kaifu Hospital remoteness medical treatment support system (k-support) by the Internet as area medical treatment support in February, 2013. This system can provide image information and patient information such as CT or the MRI to a tablet phone and the smartphone of Tokushima Prefectural Kaifu Hospital full-time employment doctors and the doctors who support it, and work in a House in real time. In other words, we can obtain necessary information without asking the when and where and can send appropriate instructions, advice to the Tokushima Prefectural Kaifu Hospital medical attendant from a specialist for it. After introduction, the treatment with this system in 58 emergency patients was carried out in seven months until August 31. The example letting the wide area present the smartphone such as this system and a remote medical treatment support system using the Internet in the medical depopulated area is the first trial in this country
Measurements of the and -induced Coherent Charged Pion Production Cross Sections on by the T2K experiment
We report an updated measurement of the -induced, and the first
measurement of the -induced coherent charged pion production
cross section on nuclei in the T2K experiment. This is measured in a
restricted region of the final-state phase space for which
GeV, and , and at a mean
(anti)neutrino energy of 0.85 GeV using the T2K near detector. The measured
CC coherent pion production flux-averaged cross section on
is . The new measurement
of the -induced cross section on is . The results are compatible with both the NEUT
5.4.0 Berger-Sehgal (2009) and GENIE 2.8.0 Rein-Sehgal (2007) model
predictions
Scintillator ageing of the T2K near detectors from 2010 to 2021
The T2K experiment widely uses plastic scintillator as a target for neutrino interactions and an active medium for the measurement of charged particles produced in neutrino interactions at its near detector complex. Over 10 years of operation the measured light yield recorded by the scintillator based subsystems has been observed to degrade by 0.9–2.2% per year. Extrapolation of the degradation rate through to 2040 indicates the recorded light yield should remain above the lower threshold used by the current reconstruction algorithms for all subsystems. This will allow the near detectors to continue contributing to important physics measurements during the T2K-II and Hyper-Kamiokande eras. Additionally, work to disentangle the degradation of the plastic scintillator and wavelength shifting fibres shows that the reduction in light yield can be attributed to the ageing of the plastic scintillator. The long component of the attenuation length of the wavelength shifting fibres was observed to degrade by 1.3–5.4% per year, while the short component of the attenuation length did not show any conclusive degradation
Measurements of the νμ and ν¯μ -induced coherent charged pion production cross sections on C12 by the T2K experiment
We report an updated measurement of the
ν
μ
-induced, and the first measurement of the
¯
ν
μ
-induced coherent charged pion production cross section on
12
C
nuclei in the Tokai-to-Kamioka experiment. This is measured in a restricted region of the final-state phase space for which
p
μ
,
π
>
0.2
GeV
,
cos
(
θ
μ
)
>
0.8
and
cos
(
θ
π
)
>
0.6
, and at a mean (anti)neutrino energy of 0.85 GeV using the T2K near detector. The measured
ν
μ
charged current coherent pion production flux-averaged cross section on
12
C
is
(
2.98
±
0.37
(
stat
)
±
0.31
(
syst
)
+
0.49
−
0.00
(
Q
2
model
)
)
×
10
−
40
cm
2
. The new measurement of the
¯
ν
μ
-induced cross section on
12
C
is
(
3.05
±
0.71
(
stat
)
±
0.39
(
syst
)
+
0.74
−
0.00
(
Q
2
model
)
)
×
10
−
40
cm
2
. The results are compatible with both the NEUT 5.4.0 Berger-Sehgal (2009) and GENIE 2.8.0 Rein-Sehgal (2007) model predictions
Design and Evaluation of Broad-Band High Pass Filter of Metal Perforated Sheets for Microwave Diagnostics
This paper reports characteristic evaluations of perforated metal sheet type high pass filters for milli- or microwave by numerical analysis and the guiding principle of designing broad-band high pass filters. The broad-band filters will be used for the microwave plasma diagnostics such as ECE, interferometer and reflectometer. We used 3D-modeling electromagnetic field calculation code to take complex interferences into account. The validity of the numerical analysis is guaranteed by a good agreement between calculated results and measured results. It is found that the frequency characteristic over the cut-off frequency depends on the filter thickness and that a thin filter is desirable for the ideal broad-band frequency filter
Design and Evaluation of Broad-Band High Pass Filter of Metal Perforated Sheets for Microwave Diagnostics
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