634 research outputs found
A Cost-effective Shuffling Method against DDoS Attacks using Moving Target Defense
Moving Target Defense (MTD) has emerged as a newcomer into the asymmetric
field of attack and defense, and shuffling-based MTD has been regarded as one
of the most effective ways to mitigate DDoS attacks. However, previous work
does not acknowledge that frequent shuffles would significantly intensify the
overhead. MTD requires a quantitative measure to compare the cost and
effectiveness of available adaptations and explore the best trade-off between
them. In this paper, therefore, we propose a new cost-effective shuffling
method against DDoS attacks using MTD. By exploiting Multi-Objective Markov
Decision Processes to model the interaction between the attacker and the
defender, and designing a cost-effective shuffling algorithm, we study the best
trade-off between the effectiveness and cost of shuffling in a given shuffling
scenario. Finally, simulation and experimentation on an experimental software
defined network (SDN) indicate that our approach imposes an acceptable
shuffling overload and is effective in mitigating DDoS attacks
A Significant Increase of RNAi Efficiency in Human Cells by the CMV Enhancer with a tRNAlys Promoter
RNA interference (RNAi) is the process of mRNA degradation induced by double-stranded RNA in a sequence-specific manner. Different types of promoters, such as U6, H1, tRNA, and CMV, have been used to control the inhibitory effect of RNAi expression vectors. In the present study, we constructed two shRNA expression vectors, respectively, controlled by tRNAlys
and CMV enhancer-tRNAlys promoters. Compared to the vectors with tRNAlys or U6 promoter, the vector with a CMV enhancer-tRNAlys promoter silenced pokemon more efficiently on both the mRNA and the protein levels. Meanwhile, the silencing of pokemon inhibited the proliferation of MCF7 cells, but the induction of apoptosis of MCF7 cells was not observed. We conclude that the CMV enhancer-tRNAlys promoter may be a powerful tool in driving intracellular expression of shRNA which can efficiently silence targeted gene
P-Glycoprotein/MDR1 Regulates Pokemon Gene Transcription Through p53 Expression in Human Breast Cancer Cells
P-glycoprotein (Pgp), encoded by the multidrug resistance 1 (MDR1) gene, is an efflux transporter and plays an important role in pharmacokinetics. In this study, we demonstrated that the pokemon promoter activity, the pokemon mRNA and protein expression can be significantly inhibited by Pgp. Chromatin immunoprecipitation assay showed that Pgp can bind the pokemon prompter to repress pokemon transcription activity. Furthermore, Pgp regulated pokemon transcription activity through expression of p53 as seen by use of p53 siRNA transfected MCF-7 cells or p53 mutated MDA-MB-231 cells. Moreover, p53 was detected to bind with Pgp in vivo using immunoprecipitation assay. Taken together, we conclude that Pgp can regulate the expression of pokemon through the presence of p53, suggesting that Pgp is a potent regulator and may offer an effective novel target for cancer therapy
PoseFusion: Robust Object-in-Hand Pose Estimation with SelectLSTM
Accurate estimation of the relative pose between an object and a robot hand
is critical for many manipulation tasks. However, most of the existing
object-in-hand pose datasets use two-finger grippers and also assume that the
object remains fixed in the hand without any relative movements, which is not
representative of real-world scenarios. To address this issue, a 6D
object-in-hand pose dataset is proposed using a teleoperation method with an
anthropomorphic Shadow Dexterous hand. Our dataset comprises RGB-D images,
proprioception and tactile data, covering diverse grasping poses, finger
contact states, and object occlusions. To overcome the significant hand
occlusion and limited tactile sensor contact in real-world scenarios, we
propose PoseFusion, a hybrid multi-modal fusion approach that integrates the
information from visual and tactile perception channels. PoseFusion generates
three candidate object poses from three estimators (tactile only, visual only,
and visuo-tactile fusion), which are then filtered by a SelectLSTM network to
select the optimal pose, avoiding inferior fusion poses resulting from modality
collapse. Extensive experiments demonstrate the robustness and advantages of
our framework. All data and codes are available on the project website:
https://elevenjiang1.github.io/ObjectInHand-Dataset
HIV Exploits Antiviral Host Innate GCN2-ATF4 Signaling for Establishing Viral Replication Early in Infection.
Antiviral innate host defenses against acute viral infections include suppression of host protein synthesis to restrict viral protein production. Less is known about mechanisms by which viral pathogens subvert host antiviral innate responses for establishing their replication and dissemination. We investigated early innate defense against human immunodeficiency virus (HIV) infection and viral evasion by utilizing human CD4+ T cell cultures in vitro and a simian immunodeficiency virus (SIV) model of AIDS in vivo Our data showed that early host innate defense against the viral infection involves GCN2-ATF4 signaling-mediated suppression of global protein synthesis, which is exploited by the virus for supporting its own replication during early viral infection and dissemination in the gut mucosa. Suppression of protein synthesis and induction of protein kinase GCN2-ATF4 signaling were detected in the gut during acute SIV infection. These changes diminished during chronic viral infection. HIV replication induced by serum deprivation in CD4+ T cells was linked to the induction of ATF4 that was recruited to the HIV long terminal repeat (LTR) to promote viral transcription. Experimental inhibition of GCN2-ATF4 signaling either by a specific inhibitor or by amino acid supplementation suppressed the induction of HIV expression. Enhancing ATF4 expression through selenium administration resulted in reactivation of latent HIV in vitro as well as ex vivo in the primary CD4+ T cells isolated from patients receiving suppressive antiretroviral therapy (ART). In summary, HIV/SIV exploits the early host antiviral response through GCN2-ATF4 signaling by utilizing ATF4 for activating the viral LTR transcription to establish initial viral replication and is a potential target for HIV prevention and therapy.IMPORTANCE Understanding how HIV overcomes host antiviral innate defense response in order to establish infection and dissemination is critical for developing prevention and treatment strategies. Most investigations focused on the viral pathogenic mechanisms leading to immune dysfunction following robust viral infection and dissemination. Less is known about mechanisms that enable HIV to establish its presence despite rapid onset of host antiviral innate response. Our novel findings provide insights into the viral strategy that hijacks the host innate response of the suppression of protein biosynthesis to restrict the virus production. The virus leverages transcription factor ATF4 expression during the GCN2-ATF4 signaling response and utilizes it to activate viral transcription through the LTR to support viral transcription and production in both HIV and SIV infections. This unique viral strategy is exploiting the innate response and is distinct from the mechanisms of immune dysfunction after the critical mass of viral loads is generated
Microbial signatures of neonatal bacterial meningitis from multiple body sites
As a common central nervous system infection in newborns, neonatal bacterial meningitis (NBM) can seriously affect their health and growth. However, although metagenomic approaches are being applied in clinical diagnostic practice, there are some limitations for whole metagenome sequencing and amplicon sequencing in handling low microbial biomass samples. Through a newly developed ultra-sensitive metagenomic sequencing method named 2bRAD-M, we investigated the microbial signatures of central nervous system infections in neonates admitted to the neonatal intensive care unit. Particularly, we recruited a total of 23 neonates suspected of having NBM and collected their blood, cerebrospinal fluid, and skin samples for 2bRAD-M sequencing. Then we developed a novel decontamination method (Reads Level Decontamination, RLD) for 2bRAD-M by which we efficiently denoised the sequencing data and found some potential biomarkers that have significantly different relative abundance between 12 patients that were diagnosed as NBM and 11 Non-NBM based on their cerebrospinal fluid (CSF) examination results. Specifically, we discovered 11 and 8 potential biomarkers for NBM in blood and CSF separately and further identified 16 and 35 microbial species that highly correlated with the physiological indicators in blood and CSF. Our study not only provide microbiological evidence to aid in the diagnosis of NBM but also demonstrated the application of an ultra-sensitive metagenomic sequencing method in pathogenesis study
2,4-Dinitrobenzaldehyde hydrazone
The title compound, C7H6N4O4, plays an important role in the synthesis of biologically active compounds. The planar hydrazone group is oriented at a dihedral angle of 8.27 (3)° with respect to the benzene ring. In the crystal structure, intermolecular N—H⋯O and N—H⋯N hydrogen bonds link the molecules
Six Thallus Surface Types of Coralline Algae with Descriptions of Two New Records of Amphiroa beauvoisii and Neogoniolithon setchellii in Sanya reef, China
Coralline algae are globally distributed calcifying species and play critical ecological roles to marine ecosystems by contributing significantly to their structural complexity and diversity. Thallus surface types of historical samples in Sanya coral reef reserve were studied based on the scanning electron microscope (SEM) method. Our results show six thallus surface types within the study area: Corallina-type, Jania-type, Leptophytum-type, Phymatolithon-type, Pneophyllum-type, and Spongites-type. The Phymatolithon-type is the dominant surface type in Sanya reefs. Two new record species in the region are described: Amphiroa beauvoisii and Neogoniolithon setchellii. Although thallus surface types provide useful diagnostics characters for distinguishing coralline algae at tribe or subfamily level, species identification needs to refer to the reproductive features. This is the first surface study of coralline algae in the South China Sea. This result provides the baseline data needed for the monitoring and management of reef-building organisms of coral reef in China
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