475 research outputs found
Breaking Temporal Consistency: Generating Video Universal Adversarial Perturbations Using Image Models
As video analysis using deep learning models becomes more widespread, the
vulnerability of such models to adversarial attacks is becoming a pressing
concern. In particular, Universal Adversarial Perturbation (UAP) poses a
significant threat, as a single perturbation can mislead deep learning models
on entire datasets. We propose a novel video UAP using image data and image
model. This enables us to take advantage of the rich image data and image
model-based studies available for video applications. However, there is a
challenge that image models are limited in their ability to analyze the
temporal aspects of videos, which is crucial for a successful video attack. To
address this challenge, we introduce the Breaking Temporal Consistency (BTC)
method, which is the first attempt to incorporate temporal information into
video attacks using image models. We aim to generate adversarial videos that
have opposite patterns to the original. Specifically, BTC-UAP minimizes the
feature similarity between neighboring frames in videos. Our approach is simple
but effective at attacking unseen video models. Additionally, it is applicable
to videos of varying lengths and invariant to temporal shifts. Our approach
surpasses existing methods in terms of effectiveness on various datasets,
including ImageNet, UCF-101, and Kinetics-400.Comment: ICCV 202
A pilot study of alterations of the gut microbiome in canine chronic kidney disease
IntroductionGut dysbiosis has been noted in humans and animals with chronic kidney disease (CKD). However, little is known about the gut microbiome in canine patients with CKD. This study aimed to analyze and compare the gut microbiome profiles of healthy and CKD dogs, including differences in the gut microbiome between each CKD stage.MethodsThe study was conducted on 29 client-owned dogs who underwent physical examination, complete blood count (CBC), serum biochemistry, and urinalysis. The gut microbiome profile of healthy dogs (n = 10) and dogs with CKD (n = 19) was analyzed employing 16S rRNA sequencing.ResultsSignificant differences were seen in the composition of the gut microbiome, with increased operational taxonomic units from the phylum Proteobacteria (p = 0.035), family Enterobacteriaceae (p < 0.001), and genus Enterococcus (p = 0.002) in dogs with CKD, and a decrease in the genus Ruminococcus (p = 0.007). Furthermore, an increase in both the progression of CKD and abundance of genus Klebsiella (Jonckheere-Terpstra test statistic value (JT) = 2.852, p = 0.004) and Clostridium (JT = 2.018, p = 0.044) was observed.DiscussionOur study demonstrated that in dogs with CKD, the composition of the gut microbiome varied depending on the stage of CKD. Alterations in gut microbiome composition observed in CKD patients are characterized by an increase in proteolytic bacteria and a decrease in saccharolytic bacteria. These findings suggest specific gut microbiota could be targeted for clinical management of uremic dogs with CKD
Optimization of extraction process for enhancement of antioxidant activity of Acer mono bark
Response surface methodology (RSM) was used for finding the optimum extraction condition of Acer mono bark. Twenty experimental conditions were set based on three key variables such as temperature, time and pressure by signalling reaction variables with 5 levels of - 2, - 1, 0, 1, 2 in accordance with central composite design for proceeding extraction and antioxidant tests. The optimized condition for the highest extraction yields was 13.10% at 83.48°C, 54.36 MPa for 13.08 minutes. For DPPH radical scavenging ability, an optimal condition was 92.89% at 88.50°C, 49.69 MPa for 15.08 minutes, and for SOD-like activity 40.69% at 85.21°C, 53.28 MPa for 15.83 minutes. The optimized condition for total polyphenol content was 4.23 mg/g at 81.51°C, 52.92 MPa for 14.79 minutes. The most optimized extraction condition was determined to be at 85°C, 52 MPa for 14 minutes for considering both extraction yield and its biological activities of this plant
Impact of commercial cigarette smoke condensate on brain tissue co-cultured with astrocytes and blood-brain barrier endothelial cells
The purpose of the current study was to investigate the effect of two commercial cigarette smoke condensates (CCSC) on oxidative stress and cell cytotoxicity in human brain (T98G) or astrocytes (U-373 MG) in the presence of human brain microvascular endothelial cells (HBMEC). Cell viability of mono-culture of T98G or U-373 MG was markedly decreased in a concentration-dependent manner, and T98G was more susceptible than U-373 MG to CCSC exposure. Cytotoxicity was less prominent when T98G was co-cultured with HBMEC than when T98G was co-cultured with U-373 MG. Significant reduction in trans-epithelial electric resistance (TEER), a biomarker of cellular integrity was noted in HBMEC co-cultured with T98G (HBMEC-T98G co-culture) and U-373 MG co-cultured with T98G (U-373 MG-T98G co-culture) after 24 or 48 hr CCSC exposure, respectively. TEER value of U-373 MG co-cultured with T98G (79-84%) was higher than HBMEC co-cultured with T98G (62-63%) within 120-hr incubation with CCSC. Reactive oxygen species (ROS) generated by CCSC in mono-culture of T98G and U-373 MG reached highest levels at 4 and 16 mg/ml, respectively. ROS production by T98G fell when co-cultured with HBMEC or U-373MG. These findings suggest that adverse consequences of CCSC treatment on brain cells may be protected by blood-brain barrier or astrocytes, but with chronic exposure toxicity may be worsened due to destruction of cellular integrity.
Differential effect of corn oil-based low trans structured fat on the plasma and hepatic lipid profile in an atherogenic mouse model: comparison to hydrogenated trans fat
<p>Abstract</p> <p>Background</p> <p><it>Trans </it>fat are not desirable in many aspects on health maintenance. Low <it>trans </it>structured fats have been reported to be relatively more safe than <it>trans </it>fats.</p> <p>Methods</p> <p>We examined the effects of low <it>trans </it>structured fat from corn oil (LC), compared with high <it>trans </it>fat shortening, on cholesterol and fatty acid metabolism in apo E deficient mice which is an atherogenic animal model. The animals were fed a high <it>trans </it>fat (10% fat: commercial shortening (CS)) or a low <it>trans </it>fat (LC) diet for 12 weeks.</p> <p>Results</p> <p>LC decreased apo B and hepatic cholesterol and triglyceride concentration compared to the CS group but significantly increased plasma total cholesterol and triglyceride concentration and fecal lipids with a simultaneous increase in HDL-cholesterol level, apo A-I, and the ratio of HDL-cholesterol to total cholesterol (HTR). Reduction of hepatic lipid levels by inclusion of LC intake was observed alongside modulation of hepatic enzyme activities related to cholesterol esterification, fatty acid metabolism and fecal lipids level compared to the CS group. The differential effects of LC intake on the plasma and hepatic lipid profile seemed to be partly due to the fatty acid composition of LC which contains higher MUFA, PUFA and SFA content as well as lower content of <it>trans </it>fatty acids compared to CS.</p> <p>Conclusions</p> <p>We suggest that LC may exert a dual effect on plasma and hepatic lipid metabolism in an atherogenic animal model. Accordingly, LC, supplemented at 10% in diet, had an anti-atherogenic effect on these <it>apo E</it><sup><it>-/- </it></sup>mice, and increased fecal lipids, decreased hepatic steatosis, but elevated plasma lipids. Further studies are needed to verify the exact mode of action regarding the complex physiological changes and alteration in lipid metabolism caused by LC.</p
Effects of Bee Venom on Glutamate-Induced Toxicity in Neuronal and Glial Cells
Bee venom (BV), which is extracted from honeybees, is used in traditional Korean medical therapy. Several groups have demonstrated the anti-inflammatory effects of BV in osteoarthritis both in vivo and in vitro. Glutamate is the predominant excitatory neurotransmitter in the central nervous system (CNS). Changes in glutamate release and uptake due to alterations in the activity of glutamate transporters have been reported in many neurodegenerative diseases, including Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis. To assess if BV can prevent glutamate-mediated neurotoxicity, we examined cell viability and signal transduction in glutamate-treated neuronal and microglial cells in the presence and absence of BV. We induced glutamatergic toxicity in neuronal cells and microglial cells and found that BV protected against cell death. Furthermore, BV significantly inhibited the cellular toxicity of glutamate, and pretreatment with BV altered MAP kinase activation (e.g., JNK, ERK, and p38) following exposure to glutamate. These findings suggest that treatment with BV may be helpful in reducing glutamatergic cell toxicity in neurodegenerative diseases
Shock ion acceleration by an ultrashort circularly polarized laser pulse via relativistic transparency in an exploded target
We investigated ion acceleration by an electrostatic shock in an exploded target irradiated by an ultrashort, circularly polarized laser pulse by means of one- and three-dimensional particle-in-cell simulations. We discovered that the laser field penetrating via relativistic transparency (RT) rapidly heated the upstream electron plasma to enable the formation of a high-speed electrostatic shock. Owing to the RT-based rapid heating and the fast compression of the initial density spike by a circularly polarized pulse, a new regime of the shock ion acceleration driven by an ultrashort (20-40 fs), moderately intense (1-1.4 PW) laser pulse is envisaged. This regime enables more efficient shock ion acceleration under a limited total pulse energy than a linearly polarized pulse with crystal laser systems of lambda similar to 1 mu mopen
Tissue-specific DNA damage response in Mouse Whole-body irradiation
Background Genomic instability is a hallmark of various cancers, and DNA repair is an essential process for maintaining genomic integrity. Mammalian cells have developed various DNA repair mechanisms in response to DNA damage. Compared to the cellular response to DNA damage, the in vivo DNA damage response (DDR) of specific tissues has not been studied extensively. Objective In this study, mice were exposed to whole-body gamma (gamma)-irradiation to evaluate the specific DDR of various tissues. We treated male C57BL6/J mice with gamma-irradiation at different doses, and the DDR protein levels in different tissues were analyzed. Results The level of gamma-H2A histone family member X (gamma H2AX) increased in most organs after exposure to gamma-irradiation. In particular, the liver, lung, and kidney tissues showed higher gamma H2AX induction upon DNA damage, compared to that in the brain, muscle, and testis tissues. RAD51 was highly expressed in the testis, irrespective of irradiation. The levels of proliferating cell nuclear antigen (PCNA) and ubiquitinated PCNA increased in lung tissues upon irradiation, suggesting that the post-replication repair may mainly operate in the lungs in response to gamma-irradiation. Conclusion These results suggest that each tissue has a preferable repair mechanism in response to gamma-irradiation. Therefore, the understanding and application of tissue-specific DNA damage responses could improve the clinical approach of radiotherapy for treating specific cancers
HIV-Specific Cellular Immune Responses Are Stimulated by Structured Treatment Interruption in Chronically HIV-1 Infected Koreans
We evaluated the enhancing effect of structured treatment interruptions (STIs) on HIV-specific immunity in chronically HIV-1 infected Korean patients. A prospective case-control study was done with a total of 10 subjects for a period of 26 weeks. Six subjects were on STIs and four subjects were on continuous HAART for comparison. The STI subjects underwent four periods of STIs. For those on STIs, HAART was stopped at week 0 for two weeks, and resumed thereafter for six weeks. Viral load and CD4+/CD8+ T cells were measured by HIV RNA RT-PCR and flow cytometry, and HIV-specific immunity was measured by an ELISPOT assay. HIV-specific cytotoxic T cell immunity was more pronounced in the STI subjects than in the continuous HAART subjects after 26 weeks (p = 0.011). The difference in cytotoxic T cell response in the STI group was more prominent than in the continuous HAART group (p = 0.011). Viral load after 26 weeks was higher in the STI subjects than in the continuous HAART subjects (p = 0.008). An HIV-specific cellular immune response can be stimulated by STIs in chronically HIV-infected Koreans. A larger study is warranted in order to further characterize viral and immunological parameters of treatment with STIs in cases of chronic HIV infection
Neuropsychological profiles of patients with obsessive-compulsive disorder: early onset versus late onset
In this study, we assess the neuropsychological profiles of both early and late symptom-onset obsessive-compulsive disorder (OCD) patients. The early and late-onset OCD patients are compared to the control group with a series of neuropsychological measurements. The late-onset OCD patients exhibited impaired performance on the immediate and the delayed recall conditions of the Rey-Osterrieth Complex Figure Test (RCFT) and the letter and category fluency of the Controlled Oral Word Association Test (COWA), compared to the normal controls and the early-onset OCD patients. The controls and early-onset OCD patients did not differ on any of the neuropsychological measurements taken in this study. These results suggest that different neurophysiological mechanisms are in play in early and late-onset OCD patients, and age of onset can serve as a potential marker for the subtyping of OCD
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