648 research outputs found
A new dynamic property of human consciousness
As pointed out by William James, "the consciousness is a dynamic process, not a thing" , during which short term integration is succeeded by another differentiated neural state through the continual interplay between the environment, the body, and the brain itself. Thus, the dynamic structure underlying successive states of the brain is important for understanding human consciousness as a process. In order to investigate the dynamic property of human consciousness, we developed a new method to reconstruct a state space from electroencephalogram(EEG), in which a trajectory, reflecting states of consciousness, is constructed based on the global information integration of the brain. EEGs were obtained from 14 subjects received an intravenous bolus of propopol. Here we show that the degree of human consciousness is directly associated with the information integration capacity of gamma wave, which is significantly higher in the conscious state than in the unconscious state. And we found a new time evolutional property of human consciousness. The conscious state showed a lower dimensional dynamic process which changed to a random-like process after loss of consciousness. This characteristic dynamic property, appeared only in the gamma band, might be used as an indicator to distinguish the conscious and unconscious states and also considered as an important fact for the human consciousness model
Propofol Induction Reduces the Capacity for Neural Information Integration: Implications for the Mechanism of Consciousness and General Anesthesia
The cognitive unbinding paradigm suggests that the synthesis of cognitive information is attenuated by general anesthesia. Here, we investigated the functional organization of brain activities in the conscious and anesthetized states, based on characteristic functional segregation and integration of electroencephalography (EEG). EEG recordings were obtained from 14 subjects undergoing induction of general anesthesia with propofol. We quantified changes in mean information integration capacity in each band of the EEG. After induction with propofol, mean information integration capacity was reduced most prominently in the gamma band of the EEG (p=0.0001). Furthermore, we demonstrate that loss of consciousness is reflected by the breakdown of the spatiotemporal organization of gamma waves. Induction of general anesthesia with propofol reduces the capacity for information integration in the brain. These data directly support the information integration theory of consciousness and the cognitive unbinding paradigm of general anesthesia
Comparison of Ulnar Collateral Ligament Reconstruction Techniques in the Elbow of Sports Players
Ulnar collateral ligament injuries have been increasingly common in overhead throwing athletes. Ulnar collateral ligament reconstruction is the current gold standard for managing ulnar collateral ligament insufficiency, and numerous reconstruction techniques have been described. Although good clinical outcomes have been reported regarding return to sports, there are still several technical issues including exposure, graft selection and fixation, and ulnar nerve management. This review article summarizes a variety of surgical techniques of ulnar collateral ligament reconstructions and compares clinical outcomes and biomechanics
Near-Infrared [Fe II] and H2 Line Observations of the Supernova Remnant 3C 396: Probing the Pre-supernova Circumstellar Materials
We present the results of near-infrared [Fe II] and H2 line imaging and
spectroscopic observations of the supernova remnant 3C 396 using the Palomar 5
m Hale telescope. We detect long, filamentary [Fe II] emission delineating the
inner edge of the radio emission in the western boundary of the remnant in
imaging observations, together with a bright [Fe II] emission clump close to
the remnant center. There appears to be faint, diffuse [Fe II] emission between
the central clump and the western filamentary emission. The spectroscopic
observations determine the expansion velocity of the central clump to be ~56
km/s. This is far smaller than the expansion velocity of 3C 396 obtained from
X-ray observations, implying the inhomogeneity of the ambient medium. The
electron number density of the [Fe II] emission gas is < 2,000 cm-3. The H2
line emission, on the other hand, lies slightly outside the filamentary [Fe II]
emission in the western boundary, and forms a rather straight filament. We
suggest that the [Fe II] emission represents dense clumps in the wind material
from the red supergiant phase of a Type IIL/b progenitor of 3C 396 which have
been swept up by the supernova remnant shocks. The H2 emission may represent
either the boundary of a wind bubble produced during the main-sequence phase of
the progenitor or molecular clumps left over inside the bubble. We propose that
the near-infrared [Fe II] and H2 emission observed in several supernova
remnants of Type IIL/b SNe likely has the same origin.Comment: 24 page including 8 figures; Accepted by Ap
Validity of gait parameters for hip flexor contracture in patients with cerebral palsy
Background: Psoas contracture is known to cause abnormal hip motion in patients with cerebral palsy. The authors investigated the clinical relevance of hip kinematic and kinetic parameters, and 3D modeled psoas length in terms of discriminant validty, convergent validity, and responsiveness. Methods: Twenty-four patients with cerebral palsy (mean age 6.9 years) and 28 normal children (mean age 7.6 years) were included. Kinematic and kinetic data were obtained by three dimensional gait analysis, and psoas lengths were determined using a musculoskeletal modeling technique. Validity of the hip parameters were evaluated. Results: In discriminant validity, maximum psoas length (effect size r = 0.740), maximum pelvic tilt (0.710), maximum hip flexion in late swing (0.728), maximum hip extension in stance (0.743), and hip flexor index (0.792) showed favorable discriminant ability between the normal controls and the patients. In convergent validity, maximum psoas length was not significantly correlated with maximum hip extension in stance in control group whereas it was correlated with maximum hip extension in stance (r = -0.933, p < 0.001) in the patients group. In responsiveness, maximum pelvic tilt (p = 0.008), maximum hip extension in stance (p = 0.001), maximum psoas length (p < 0.001), and hip flexor index (p < 0.001) showed significant improvement post-operatively. Conclusions: Maximum pelvic tilt, maximum psoas length, hip flexor index, and maximum hip extension in stance were found to be clinically relevant parameters in evaluating hip flexor contracture.Y
AKARI Detection of the Infrared-Bright Supernova Remnant B0104-72.3 in the Small Magellanic Cloud
We present a serendipitous detection of the infrared-bright supernova remnant
(SNR) B0104-72.3 in the Small Magellanic Cloud by the Infrared Camera (IRC)
onboard AKARI. An elongated, partially complete shell is detected in all four
observed IRC bands covering 2.6-15 um. The infrared shell surrounds radio,
optical, and X-ray emission associated with the SNR and is probably a radiative
SNR shell. This is the first detection of a SNR shell in this near/mid-infrared
waveband in the Small Magellanic Cloud. The IRC color indicates that the
infrared emission might be from shocked H2 molecules with some possible
contributions from ionic lines. We conclude that B0104-72.3 is a middle-aged
SNR interacting with molecular clouds, similar to the Galactic SNR IC 443. Our
results highlight the potential of AKARI IRC observations in studying SNRs,
especially for diagnosing SNR shocks.Comment: 12 pages with 3 figures, accepted for publication in AKARI PASJ
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