920 research outputs found
New Cache Attacks and Defenses
The sharing of last-level cache (LLC) among different physical cores makes cache vulnerable to side channel attacks. An attacker can get private information about co-running applications (victims) by monitoring their accesses. Cache side channel attacks can be mitigated by partitioning cache between the victim and attacker. However, previous partition works make the incorrect assumption that only the victim's cache misses are visible to attackers.
In this work, we provide the key insight that both cache hits and cache misses from the victim are vulnerable. For a cache hit,
although it does not affect the existence state, it can still change the replacement state and coherence state, which can also leak information to attackers. Based on this, we propose Invisible-Victim cache (IVcache), a new cache design that can mitigate both traditional LLC attacks and the new variants. IVcache classifies all processes as protected and unprotected. For accesses from protected processes, IVcache handles state changes in a slightly different way to make those accesses absolutely invisible to any other processes. We evaluate the defense effectiveness and performance of IVcache in the gem5 simulator. We show that IVcache can defend against real-world attacks, and that it introduces negligible performance effect to both protected and unprotected processes
Charles Dickensâ Benevolent Spirit as Revealed in A Tale of Two Cities
A Tale of Two Cities, one of Charles Dickensâ most representative work, reveals and criticizes the fact that the working people suffered the oppression from the aristocracy. Moreover, the novel showed that the revolution was bloody and cruel. Dickens revealed his benevolent spirit, namely, he showed sympathy for the poor working people and urged people to use love to dissolve hatred. Some critics thought that his spirit was unpractical fantasy. Through the analysis of Dickensâ life and times, the novel A Tale of Two Cities as well as his other works, the author points out that Dickensâ benevolent spirit has its practical meaning in modern times
Theoretical Investigation of Kainate Receptor GluK2 and Channelrhodopsin-2: Structure and Mechanism
This work focuses on the structures and mechanisms of functions of two different proteins: kainate receptor GluK2 and channelrhodopsin-2. They are able to activate neuron cells or transfer signals upon illumination, and thus, control and monitor neuron cell activities in living tissues. This technique is called optogenetics. The structure-function relationships of the proteins were investigated with multi-scale techniques, combining classic mechanical (MM) and quantum mechanical (QM) methods
Engineering the side facets of vertical [100] oriented InP nanowires for novel radial heterostructures
In addition to being grown on industry-standard orientation, vertical [100] oriented nanowires present novel families of facets and related cross-sectional shapes. These nanowires are engineered to achieve a number of facet combinations and cross-sectional shapes, by varying their growth parameters within ranges that facilitate vertical growth. In situ post-growth annealing technique is used to realise other combinations that are unattainable solely using growth parameters. Two examples of possible novel radial heterostructures grown on these vertical [100] oriented nanowire facets are presented, demonstrating their potential in future applications
Influence of catwalk design parameters on the galloping of constructing main cables in long-span suspension bridges
A main cable of a long-span suspension bridge is semi-surrounded by a catwalk during construction. Thus, design parameters of a catwalk may have influences on the galloping stability of a main cable during construction. To study the influence of catwalk design parameters on the galloping of steepled main cables, two main foci have been conducted. Firstly, the aerodynamic coefficients of the catwalk with actual design parameters are obtained by numerical simulation based on computational fluid dynamics (CFD), and the numerical results are compared with those of the previous wind tunnel test. Several typical main cables with different cross sections of a long-span suspension bridge during construction are selected, and their Den Hartog coefficients are obtained based on the numerical simulation considering the aerodynamic influences of the catwalks. Then four typical working conditions of a main cable which have great potential to occur galloping are selected based on the galloping analyze, and their aerodynamic coefficients considering the influence of the catwalk with different design parameters are obtained. The influence of the catwalk design parameters on galloping of the main cables is analyzed based on the Den Hartog criterion. Results indicate that catwalk design parameters have evident influences on aerodynamic coefficients and galloping of the main cables. The parameters of the catwalk which are favorable for suppressing the galloping of the main cables are determined, which establish a good guideline for the galloping-resistant design of the catwalk-main cable system on suspension bridges
Antimikrobna rezistencija i svojstva virulencije bakterije Enterococcus faecium izolirane u goveda s kliniÄkim mastitisom iz pokrajine Ningxia, Kina
This study was conducted to determine the antimicrobial resistance and virulence traits of 32 Enterococcus faecium isolates from clinical bovine mastitis cases in Ningxia Province, China. In total, 32 E. faecium isolates were taken from subclinical bovine mastitis on the basis of morphological characterization and biochemical testing, and screened for antimicrobial susceptibility. The virulence genes of the isolates were studied using polymerase chain reaction (PCR). The disc diffusion assay revealed a high occurrence of resistance against tetracycline (78.1%) and erythromycin (68.8%) in the E. faecium isolates. However, all tested E. faecium were susceptible to linezolid and vancomycin. Moreover, all E. faecium isolates harbored the erythromycin-resistant genes ermA, ermB and ermC, as well as the tetracycline-resistant genes tetK, tetL and tetM. Furthermore, all E. faecium isolates carried more than 3 of the tested virulence genes. The presence of agg (100%), cpd (100%), efaA (100%), gelE (93.4%), and esp (75.0%) was found most frequently in all the tested isolates. These findings are useful for making appropriate antimicrobial choices and developing antivirulence therapies for subclinical bovine mastitis caused by E. faecium in Ningxia Province, China.IstraĆŸivanje je provedeno kako bi se odredila antimikrobina rezistencija i svojstva virulencije izolata bakterije Enterococcus faecium uzetih u goveda s kliniÄkim mastitisom. U ukupno 32 izolata goveda iz pokrajine Ningxia u Kini, procijenjena je antimikrobna osjetljivost na temelju morfoloĆĄke karakterizacije i biokemijskih pretraga. Geni virulencije izolata istraĆŸeni su polimeraznom lanÄanom reakcijom (PCR). Disk-difuzijski test je u izolatu bakterije E. faecium pokazao visoku pojavnost rezistencije na tetraciklin (78,1 %) i eritromicin (68,8 %). Svi su pretraĆŸeni izolati bili osjetljivi na linezolid i vankomicin i imali gene rezisentne na eritromicin ermA, ermB i ermC, kao i na tetraciklin, tetK, tetL i tetM. Osim toga svi izolati E. faecium nosili su viĆĄe od tri istraĆŸivana gena virulencije. NajÄeĆĄÄi geni bili agg (100 %), cpd (100 %), efaA (100 %), gelE (93,4 %) i esp (75,0 %). Ovi rezultati mogu u pokrajini Ningxia u Kini pridonijeti pravilnom izboru antimikrobnog lijeka i razvoju uspjeĆĄne terapije za supkliniÄki goveÄi mastitis uzrokovan bakterijom E. faecium
Prognostic value of osteopontin splice variant-c expression in breast cancers: a meta-analysis
Objectives. Osteopontin (OPN) is overexpressed in breast cancers, while its clinical and prognostic significance remained unclear. This study aimed to assess the prognostic value of OPN, especially its splice variants, in breast cancers. Methods. Data were extracted from eligible studies concerning the OPN and OPN-c expression in breast cancer patients and were used to calculate the association between OPN/OPN-c and survival. Two reviewer teams independently screened the literatures according to the inclusion and exclusion criteria based on quality evaluation. Following the processes of data extraction, assessment, and transformation, meta-analysis was carried out via RevMan 5.3 software. Results. A total of ten studies involving 1,567 patients were included. The results demonstrated that high level OPN indicated a poor outcome in the OS (HR = 2.22, 95% CI: 1.23â4.00, and ; random-effects model) with heterogeneity (%) of breast cancer patients. High level OPN-c appeared to be more significantly associated with poor survival (HR = 2.14, 95% CI: 1.51â3.04, and ; fixed-effects model) with undetected heterogeneity (%). Conclusions. Our analyses indicated that both OPN and OPN-c could be considered as prognostic markers for breast cancers. The high level of OPN-c was suggested to be more reliably associated with poor survival in breast cancer patients
CosmoVAE: Variational Autoencoder for CMB Image Inpainting
Cosmic microwave background radiation (CMB) is critical to the understanding
of the early universe and precise estimation of cosmological constants. Due to
the contamination of thermal dust noise in the galaxy, the CMB map that is an
image on the two-dimensional sphere has missing observations, mainly
concentrated on the equatorial region. The noise of the CMB map has a
significant impact on the estimation precision for cosmological parameters.
Inpainting the CMB map can effectively reduce the uncertainty of parametric
estimation. In this paper, we propose a deep learning-based variational
autoencoder --- CosmoVAE, to restoring the missing observations of the CMB map.
The input and output of CosmoVAE are square images. To generate training,
validation, and test data sets, we segment the full-sky CMB map into many small
images by Cartesian projection. CosmoVAE assigns physical quantities to the
parameters of the VAE network by using the angular power spectrum of the
Gaussian random field as latent variables. CosmoVAE adopts a new loss function
to improve the learning performance of the model, which consists of
reconstruction loss, Kullback-Leibler divergence between the posterior
distribution of encoder network and the prior distribution of latent variables,
perceptual loss, and total-variation regularizer. The proposed model achieves
state of the art performance for Planck \texttt{Commander} 2018 CMB map
inpainting.Comment: 7 pages, 6 figure
Molecular Dynamics Investigation of gluazo, a Photo-Switchable Ligand for the Glutamate Receptor GluK2
Photochromic ligands (PCLs), defined as photoswitchable molecules that are able to endow native receptors with a sensitivity towards light, have become a promising photo-pharmacological tool for various applications in biology. In general, PCLs consist of a ligand of the target receptor covalently linked to an azobenzene, which can be reversibly switched between two configurations upon light illumination. Gluazo, as a PCL that targets excitatory amino acid receptors, in its dark-adapted trans iso-form was characterized to be a partial agonist of the kainate glutamate receptor GluK2. Application of UV light leads to the formation of the cis form, with remarkedly reduced affinity towards GluK2. The mechanism of the change of ligand affinity induced by the photoisomerization was unresolved. The presented computational study explains how the somerization of such a PCL affects the structural changes in the target receptor that lead to its activation
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