98 research outputs found
Understanding Open-Set Recognition by Jacobian Norm of Representation
In contrast to conventional closed-set recognition, open-set recognition
(OSR) assumes the presence of an unknown class, which is not seen to a model
during training. One predominant approach in OSR is metric learning, where a
model is trained to separate the inter-class representations of known class
data. Numerous works in OSR reported that, even though the models are trained
only with the known class data, the models become aware of the unknown, and
learn to separate the unknown class representations from the known class
representations. This paper analyzes this emergent phenomenon by observing the
Jacobian norm of representation. We theoretically show that minimizing the
intra-class distances within the known set reduces the Jacobian norm of known
class representations while maximizing the inter-class distances within the
known set increases the Jacobian norm of the unknown class. The closed-set
metric learning thus separates the unknown from the known by forcing their
Jacobian norm values to differ. We empirically validate our theoretical
framework with ample pieces of evidence using standard OSR datasets. Moreover,
under our theoretical framework, we explain how the standard deep learning
techniques can be helpful for OSR and use the framework as a guiding principle
to develop an effective OSR model
Glycogen synthase kinase 3 beta suppresses polyglutamine aggregation by inhibiting Vaccinia-related kinase 2 activity
Huntington's disease (HD) is a neurodegenerative disorder caused by an abnormal expansion of polyglutamine repeats in the N-terminal of huntingtin. The amount of aggregate-prone protein is controlled by various mechanisms, including molecular chaperones. Vaccinia-related kinase 2 (VRK2) is known to negatively regulate chaperonin TRiC, and VRK2-facilitated degradation of TRiC increases polyQ protein aggregation, which is involved in HD. We found that VRK2 activity was negatively controlled by glycogen synthase kinase 3 beta (GSK3 beta). GSK3 beta directly bound to VRK2 and inhibited the catalytic activity of VRK2 in a kinase activity-independent manner. Furthermore, GSK3 beta increased the stability of TRiC and decreased the formation of HttQ103-GFP aggregates by inhibiting VRK2. These results indicate that GSK3 beta signaling may be a regulatory mechanism of HD progression and suggest targets for further therapeutic trials for HD.1131Ysciescopu
Measuring the social value of nuclear energy using contingent valuation methodology
As one of the promising energy sources for the next few decades, nuclear energy receives more attention than before as environmental issues become more important and the supply of fossil fuels becomes unstable. One of the reasons for this attention is based on the rapid innovation of nuclear
technology which solves many of its technological constraints and safety issues. However, regardless of
these rapid innovations, social acceptance for nuclear energy has been relatively low and unchanged. Consequently, the social perception has often been an obstacle to the development and execution of nuclear policy requiring enormous subsidies which are not based on the social value of nuclear energy. Therefore, in this study, we estimate the social value of nuclear energy-consumers’ willingness-to-pay for nuclear energy—using the Contingent Valuation Method (CVM) and suggest that the social value of nuclear energy increases approximately 68.5% with the provision of adequate information about nuclear energy to the public. Consequently, we suggest that the social acceptance management in nuclear policy development is important along with nuclear technology innovation
The application of a dual-lead locking screw could enhance the reduction and fixation stability of the proximal humerus fractures: a biomechanical evaluation
IntroductionBicortical screw fixation, which penetrates and fixes the near and far cortex of bone, has been conventionally used to achieve compressive fixation for fracture using screws. Open reduction and internal fixation using the locking plate are widely used for treating proximal humerus fractures. However, minimal contact between the bone and the locking plate can lead to an insufficient reduction. Theoretically, a dual-lead locking screw with different leads for the screw head and body could enhance the reduction and fixation stability of fragments in proximal humeral fractures without bicortical fixation, and achieve additional compression at the bone-plate-screw interface. This study assessed the insertion mechanics of the lead ratio of the dual-lead locking screw and its effect on the fixation stability of the proximal humerus fracture.MethodsA Multi-Fix® locking plating system composed of ∅ 3.5 mm locking screws and a locking plate was used to make a locked plating for Sawbone bone blocks and fourth-generation composite humeri. Two different types of Sawbone bone blocks were used to simulate the osteoporotic (10 PCF) and normal cancellous (20 PCF) bones. The lead of the screw head thread (Lhead) was 0.8 mm, and that of the screw body (Lbody) was 0.8, 1.25, 1.6, 2.0, and 2.4 mm, whose lead ratios (Rlead=Lbody/Lhead) were 1.0, 1.56, 2.0, 2.5, and 3.0, respectively.ResultsThe dual-lead locking screw elevated the compression between the locking plate and the bone. The elevation in the compression due to the dual-lead thread became weaker for the cancellous bone when the lead of the screw body was more than twice that of the screw head. The plate/humerus compression with strong bone quality withstood higher dual-lead-driven compression.DiscussionA dual-lead locking screw of Lbody=1.25mm (Rlead=1.56) is recommended for maximum rotational stability for the locked humerus plating. The screws with over Lbody=1.6mm (Rlead=2) have no advantage in terms of the failure torque and maximum torsional deformation. Any locking dual-lead screw with a body thread lead of <1.6 mm (Rlead=2) can be used without the risk of bone crush when surgeons require additional compression to the locked cancellous bone plating
Higher Plasma Stromal Cell-Derived Factor 1 Is Associated with Lower Risk for Sarcopenia in Older Asian Adults
Background Despite the protective effects of stromal cell-derived factor 1 (SDF-1) in stimulating muscle regeneration shown in experimental research, there is a lack of clinical studies linking circulating SDF-1 concentrations with muscle phenotypes. In order to elucidate the role of SDF-1 as a potential biomarker reflecting human muscle health, we investigated the association of plasma SDF-1 levels with sarcopenia in older adults. Methods This cross-sectional study included 97 community-dwelling participants who underwent a comprehensive geriatric assessment at a tertiary hospital in South Korea. Sarcopenia was defined by specific cutoff values applicable to the Asian population, whereas plasma SDF-1 levels were determined using an enzyme immunoassay. Results After accounting for sex, age, and body mass index, participants with sarcopenia and low muscle mass exhibited plasma SDF-1 levels that were 21.8% and 18.3% lower than those without these conditions, respectively (P=0.008 and P=0.009, respectively). Consistently, higher plasma SDF-1 levels exhibited a significant correlation with higher skeletal muscle mass index (SMI) and gait speed (both P=0.043), and the risk of sarcopenia and low muscle mass decreased by 58% and 55% per standard deviation increase in plasma SDF-1 levels, respectively (P=0.045 and P=0.030, respectively). Furthermore, participants in the highest SDF-1 tertile exhibited significantly higher SMI compared to those in the lowest tertile (P=0.012). Conclusion These findings clinically corroborate earlier experimental discoveries highlighting the muscle anabolic effects of SDF-1 and support the potential role of circulating SDF-1 as a biomarker reflecting human muscle health in older adults
Effects of daily quercetin-rich supplementation on cardiometabolic risks in male smokers
Limited information from human studies indicates that dietary quercetin supplementation influences blood lipid profiles, glycemic response, and inflammatory status, collectively termed cardiometabolic risks. We tested the hypothesis that quercetin-rich supplementation, derived from onion peel extract, improves cardiometabolic risk components in healthy male smokers in a randomized, double blinded, placebo-controlled parallel design. Randomly assigned subjects were instructed to take either the placebo (n = 43) or 100 mg quercetin capsules each day (n = 49) for 10 weeks. Anthropometric parameters and blood pressure were measured, and blood lipids, glucose, interleukin-6, and soluble vascular cell adhesion molecule-1 (sVCAM-1) were determined at baseline and after 10 weeks of quercetin supplementation. Quercetin-rich supplementation significantly reduced serum concentrations of total cholesterol (P < 0.05) and LDL-cholesterol (P < 0.01), whereas these effects were not shown in the placebo group. Furthermore, significant increases were observed in serum concentrations of HDL-cholesterol both in the placebo (P < 0.005) and quercetin-rich supplementation group (P < 0.001); however, changes in HDL-cholesterol were significantly greater in subjects receiving quercetin-rich supplementation than the placebo. Both systolic (P < 0.05) and diastolic blood pressure (P < 0.01) decreased significantly in the quercetin-rich supplementation group. Glucose concentrations decreased significantly after 10 weeks of quercetin-rich supplementation (P < 0.05). In contrast, no effects of quercetin-rich supplementation were observed for the inflammatory markers-IL-6 and sVCAM-1. Daily quercetin-rich supplementation from onion peel extract improved blood lipid profiles, glucose, and blood pressure, suggesting a beneficial role for quercetin as a preventive measure against cardiovascular risk
Increased Inflammation, Reduced Plasma Phospholipid Eicosapentaenoic Acid and Reduced Antioxidant Potential of Treated Hypertensive Patients with Metabolic Syndrome
PURPOSE: In the present study, we tested whether the presence of metabolic syndrome (MetS) would worsen the features of inflammation, plasma omega 3 fatty acid levels and antioxidant potential in treated hypertensive patients.
MATERIALS AND METHODS: TWO GROUPS WERE CLASSIFIED BY THE COMPONENTS OF METS: a reference group of treated hypertensive subjects: hypertension (HTN) group (n = 39) and with more than two additional MetS components: HTN with Mets group (n = 40). We further compared the parameters between HTN group and HTN with MetS group.
RESULTS: The results showed that age (p < 0.001) and body mass index (BMI) (p < 0.001) were significantly different between HTN group and HTN with MetS group. Age- and BMI-adjusted total radical trapping antioxidant potential (TRAP) (p < 0.01) was significantly lower, whereas age- and BMI-adjusted CD (p < 0.05) and interleukin (IL) 6 (p < 0.05) were significantly higher in HTN with MetS group than in HTN group. Moreover, HTN with MetS group had significantly lower levels of age- and BMI-adjusted plasma phospholipid eicosapentaenoic acid (EPA) than HTN group (p < 0.05). On the other hand, the levels of age- and BMI-adjusted intracellular cell adhesion molecule-1 (ICAM-1), adiponectin and high molecular weight (HMW)-adiponectin were not significantly different between the groups.
CONCLUSION: In conclusion, our results showed increased inflammatory marker, reduced antioxidant potential and EPA levels in treated hypertensive patients in the presence of MetS, suggesting the importance of changes of therapeutic lifestyle to modify the features of MetS.ope
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Development and Validation of a Music-based Attention Assessment for Patients with Traumatic Brain Injury
Impairments in attention are commonly seen in individuals with traumatic brain injury (TBI). While attention assessment measurements have been developed rigorously and utilized frequently in cognitive neurorehabilitation, there is a paucity of auditory attention assessment instruments that are ecologically valid and that assess different subtypes of attention. Yet, deficits in auditory attention can severely limit everyday functioning, negatively impact work and personal relationships and compromise personal safety. The purpose of this study was to develop and to investigate the psychometric properties of a Music-based Attention Assessment (MAA) instrument. The MAA is a multiple choice, melodic contour identification test, designed to assess three different types of auditory attention, including sustained attention, selective attention, and divided attention. The MAA was piloted with patients with TBI (n = 15) and healthy adults (n = 30) separately to evaluate preliminary psychometric properties. Both pilot studies reported that the MAA possessed a very high reliability and appropriate item properties. However, the MAA was revised due to a ceiling effect on mean test scores in the healthy adult group. The revised version of the MAA was administered to healthy adults (n = 165) as well as TBI patients (n= 22) to investigate construct validity, item properties, test reliability, and difference in MAA performance between groups. Here, psychometric validation of the revised version of the MAA is described, and the obtained results reported. Exploratory factor analysis identified five-factor constructs, supporting the different types of attention that underlie the test items of the revised version of the MAA. The factors identified were Sustained-Short, Sustained-Med to Long, Selective-Noise, Selective & Divided, and Divided-Long. After item elimination, the finalized 45-item MAA in relation to the identified five-factor constructs provided evidence of high internal consistencies as computed by split-half reliability coefficients (r = .836) and Cronbach’s alpha (α = .940), indicating homogeneity of test items within each of the five subtest as well as for the total test. As predicted, significant differences were found between the healthy adult and TBI patient samples across the exploratively obtained five-factor constructs of the revised version of the MAA. The MAA performance was significantly better in the healthy adult group than in the TBI patient group, except on the Sustained Attention–Short Subtest, indicating pervasive attention impairments in patients with TBI. The finding also suggests that a basic level of sustained attention to deal with a small amount of auditory information during a limited time might be intact for the patients with TBI who have a moderate to severe level of brain injury. The aggregate findings suggest that the MAA is a valid and reliable measure that provides diagnostic information in regards to the three types of auditory attention deficits frequently observed in patients with TBI. The use of melodic contours in attention assessment is discussed along with limitations of the study and suggestions for future research. The MAA, when used in conjunction with attention assessment instruments in different sensory modalities, would provide a greater level of precision in the attention assessment of patients with TBI, resulting in more symptom specific and individualized rehabilitation and treatment
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