1,602 research outputs found
A novel regulator of the p53-mediated mitochondrial apoptotic pathway
The p53 tumor suppressor protein induces apoptosis in response to genotoxic and environmental stress. Recent studies have revealed the existence of a transcription-independent mitochondrial p53 apoptosis pathway, however the mechanism regulating p53 translocation to mitochondria and subsequent initiation of apoptosis was not known. Here, we show that Tid1, also known as mtHsp40 or Dnaja3, interacts with p53 and directs its translocation to mitochondria in cells exposed to hypoxia. Overexpression of Tid1 in tumor cells promoted mitochondrial localization of both wildtype and mutant forms of p53 and was able to restore the pro-apoptotic activity of mutant p53 proteins that were otherwise unable to induce apoptosis. Tid1's mitochondrial signal sequence and DnaJ domain were both required for the movement of the p53-Tid1 complex from the cytosol to the mitochondria. Our findings establish Tid1 as a novel regulator of p53 localization and apoptotic function
Proto-type installation of a double-station system for the optical-video-detection and orbital characterisation of a meteor/fireball in South Korea
We give a detailed description of the installation and operation of a
double-station meteor detection system which formed part of a research &
education project between Korea Astronomy Space Science Institute and Daejeon
Science Highschool. A total of six light-sensitive CCD cameras were installed
with three cameras at SOAO and three cameras at BOAO observatory. A
double-station observation of a meteor event enables the determination of the
three-dimensional orbit in space. This project was initiated in response to the
Jinju fireball event in March 2014. The cameras were installed in
October/November 2014. The two stations are identical in hardware as well as
software. Each station employes sensitive Watec-902H2 cameras in combination
with relatively fast f/1.2 lenses. Various fields of views were used for
measuring differences in detection rates of meteor events. We employed the
SonotaCo UFO software suite for meteor detection and their subsequent analysis.
The system setup as well as installation/operation experience is described and
first results are presented. We also give a brief overview of historic as well
as recent meteor (fall) detections in South Korea. For more information please
consult http://meteor.kasi.re.kr .Comment: Technical/instrumentation description of a professional meteor
detection system, 23 pages, 20 figures (color/monochrome), 5 tables,
submitted to the Journal of Korean Astronomical Society (JKAS,
http://jkas.kas.org/, http://jkas.kas.org/history.html
Resting-state EEG, impulsiveness, and personality in daily and nondaily smokers
OBJECTIVES:
Resting EEG is sensitive to transient, acute effects of nicotine administration and abstinence, but the chronic effects of smoking on EEG are poorly characterized. This study measures the resting EEG profile of chronic smokers in a non-deprived, non-peak state to test whether differences in smoking behavior and personality traits affect pharmaco-EEG response.
METHODS:
Resting EEG, impulsiveness, and personality measures were collected from daily smokers (n=22), nondaily smokers (n=31), and non-smokers (n=30).
RESULTS:
Daily smokers had reduced resting delta and alpha EEG power and higher impulsiveness (Barratt Impulsiveness Scale) compared to nondaily smokers and non-smokers. Both daily and nondaily smokers discounted delayed rewards more steeply, reported lower conscientiousness (NEO-FFI), and reported greater disinhibition and experience seeking (Sensation Seeking Scale) than non-smokers. Nondaily smokers reported greater sensory hedonia than nonsmokers.
CONCLUSIONS:
Altered resting EEG power in daily smokers demonstrates differences in neural signaling that correlated with greater smoking behavior and dependence. Although nondaily smokers share some characteristics with daily smokers that may predict smoking initiation and maintenance, they differ on measures of impulsiveness and resting EEG power.
SIGNIFICANCE:
Resting EEG in non-deprived chronic smokers provides a standard for comparison to peak and trough nicotine states and may serve as a biomarker for nicotine dependence, relapse risk, and recovery
Pole-skipping points in 2D gravity and SYK model
We represent the first investigation of pole-skipping on both the gravity and
field theory sides. In contrast to the higher dimensional models, there is no
momentum degree of freedom in dimensional bulk theory. Thus, we then
consider a scalar field mass as our degree of freedom for the pole-skipping
phenomenon instead of momentum. The pole-skipping frequencies of the scalar
field in 2D gravity are the same as higher dimensional cases: for positive integer . At each of these frequencies, there is a
corresponding pole-skipping mass, so the pole-skipping points exist in the
space. We also compute the pole-skipping points of the SYK model
in space where is the dimension of the bilinear primary
operator. We find that there is a one-to-one correspondence of the
pole-skipping points between the JT gravity and the SYK model. To obtain the
pole-skipping points, we need to consider the parameter related to
chemical potential on the horizon of charged JT gravity and the particle-hole
asymmetric parameter of the complex SYK model as shift
parameters. This highlights the correspondence in
relation to pole-skipping
Predicting the Knowledge: Recklessness Distinction in the Human Brain
Criminal convictions require proof that a prohibited act was performed in a statutorily specified mental state. Different legal consequences, including greater punishments, are mandated for those who act in a state of knowledge, compared with a state of recklessness. Existing research, however, suggests people have trouble classifying defendants as knowing, rather than reckless, even when instructed on the relevant legal criteria.
We used a machine-learning technique on brain imaging data to predict, with high accuracy, which mental state our participants were in. This predictive ability depended on both the magnitude of the risks and the amount of information about those risks possessed by the participants. Our results provide neural evidence of a detectable difference in the mental state of knowledge in contrast to recklessness and suggest, as a proof of principle, the possibility of inferring from brain data in which legally relevant category a person belongs. Some potential legal implications of this result are discussed
Structural performance experiment by moving cart to mount measurement sensors
The development of a measurement system for the purpose of structural performance evaluation has been needed. This work introduces a moving cart system on which to mount measurement sensors to measure acceleration and sound pressure in the time domain and an impact hammer for external excitation. The measurement data are utilized to evaluate the structural performance based on a mixed approach to directly and indirectly collect response data by a microphone and an accelerometer, respectively. The reliability of the measurement data is improved by the utilization of multiple sensors. The structural state is investigated by the power spectral density estimate (PSE) or proper orthogonal mode (POM) of the sound pressure and acceleration data. The applicability of the system is illustrated in a field test
Transient receptor potential channel TRPV4 mediates TGF-β1-induced differentiation of human ventricular fibroblasts
Background: Cardiac fibroblasts (CFs) are principal extracellular matrix-producing cells. In response to injury, CFs transdifferentiate into myofibroblasts. Intracellular calcium (Ca2+) signaling, involved in fibroblast proliferation and differentiation, is activated in fibroblasts through transient receptor potential (TRP) channels, but the function of these channels has not been investigated in human ventricular CFs. Under evaluation in this study, was the role of TRP channels in the differentiation of human ventricular CFs induced by transforming the growth factor beta (TGF-β), a pro-fibrotic cytokine.
Methods: Human ventricular CFs were used in this study. The differentiation of CFs into myofibroblast was induced with TGF-β and was identified by the expression of smooth muscle actin.
Results: Results indicate that Ca2+ signaling was an essential component of ventricular CF differentiation. CFs treated with TGF-β demonstrated increased expression of a TRP channel, TRPV4, both at the mRNA and protein levels, which corresponded with CF-myofibroblast trans-differentiation, as evidenced by the upregulation of α-smooth muscle actin, a myofibroblast marker, and plasminogen activator inhibitor-1, which are fibrogenesis markers. An agonist of TRPV4 induced the conversion of CFs into myofibroblasts, whereas it’s antagonist as well a Ca2+ chelating agent reduced it, indicating that the Ca2+ influx throughTRPV4 is required for CF trans-differentiation. Overall, these results demonstrate that TRPV4-mediated Ca2+ influx participates in regulating the differentiation of human ventricular CFs into myofibroblasts through the MAPK/ERK pathway.
Conclusions: Overall, these results demonstrate that TRPV4-mediated Ca2+ influx participates in regulating the differentiation of human ventricular CFs into myofibroblasts through the MAPK/ERK pathway
Can a Biomechanical Foot Orthosis Affect Gait in Patients With Hallux Valgus? A Pilot Study
Objective To investigate the effects of customized biomechanical foot orthosis (BFO) on kinematic data during gait in patients with hallux valgus (HV) deformities and compare the results with those of a normal control group. Methods Ten patients with HV deformities and 10 healthy volunteers were enrolled in this study. HV deformity was diagnosed using biomechanical and radiological assessments by a rehabilitation physician. Patients received the customized BFO manufactured at a commercial orthosis laboratory (Biomechanics, Goyang, South Korea) according to the strictly defined procedure by a single experienced technician. The spatiotemporal and kinematic data acquired by the Vicon 3D motion capture system (Oxford Metrics, Oxford, UK) were compared between the intervention groups (control vs. HV without orthosis) and between the HV groups (with vs. without orthosis). Results The temporal-spatial and kinematic parameters of the HV group were significantly different from those of the control group. After applying BFO to the HV group, significantly increased ranges of plantar flexion motion and hindfoot inversion were observed. Furthermore, the HV group with BFO showed improved gait cadence, walking speed, and stride length, although the results were not statistically significant. Conclusion Our results suggest that it is imperative to understand the pathophysiology of HV, and the application of customized BFO can be useful for improving kinematics in HV deformities
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