30 research outputs found
TNC-UTM: A Holistic Solution to Secure Enterprise Networks
This paper presents TNC-UTM, a holistic solution to secure enterprise networks from gateway to endpoints. Just as its name suggested, the TNC-UTM solution combines two popular techniques TNC and UTM together by defining an interface between them that integrates their security capacity to provide efficiently network access control and security protection for enterprise network. Not only TNC-UTM provides the features of TNC and UTM, but also it achieves stronger security and higher performance by introducing intelligent configuration decisions and RBAC mechanism. Experiment demonstrated the superior advantages of the TNC-UTM solution
Verification of the standard theory of plasma emission with particle-in-cell simulations
The standard theory of plasma emission is based on kinetic couplings between
a single beam of energetic electrons and unmagnetized thermal plasmas,
involving multi-step nonlinear wave-particle and wave-wave interactions. The
theory has not yet been completely verified with fully-kinetic electromagnetic
particle-in-cell (PIC) simulations. Earlier studies, greatly limited by
available computational resources, are controversial regarding whether the
fundamental emission can be generated according to the standard theory. To
resolve the controversy, we conducted PIC simulations with a large domain of
simulation and a large number of macroparticles, among the largest ones of
similar studies. We found significant fundamental emission if the relative beam
density is small enough (say, 0.01), in line with earlier study with a
much-smaller domain; the relative intensity (normalized by the total initial
beam energy) of all modes, except the mode associated with the
beam-electromagnetic Weibel instability, decreases with increasing relative
density of the beam. We also found significant transverse magnetic component
associated with the superluminal Langmuir turbulence, which has been mistakenly
regarded as evidence of the F emission in earlier study. Further investigations
are required to reveal their origin
Neutron Scattering Signature of Phonon Renormalization in Nickel (II) Oxide
The physics of mutual interaction of phonon quasiparticles with electronic
spin degrees of freedom, leading to unusual transport phenomena of spin and
heat, has been a subject of continuing interests for decades. Despite its
pivotal role in transport processes, the effect of spin-phonon coupling on the
phonon system, especially acoustic phonon properties, has so far been elusive.
By means of inelastic neutron scattering and first-principles calculations,
anomalous scattering spectral intensity from acoustic phonons was identified in
the exemplary collinear antiferromagnetic nickel (II) oxide, unveiling strong
spin-lattice correlations that renormalize the polarization of acoustic phonon.
In particular, a clear magnetic scattering signature of the measured neutron
scattering intensity from acoustic phonons is demonstrated by its momentum
transfer and temperature dependences. The anomalous scattering intensity is
successfully modeled with a modified magneto-vibrational scattering cross
section, suggesting the presence of spin precession driven by phonon. The
renormalization of phonon eigenvector is indicated by the observed
"geometry-forbidden" neutron scattering intensity from transverse acoustic
phonon. Importantly, the eigenvector renormalization cannot be explained by
magnetostriction but instead, it could result from the coupling between phonon
and local magnetization of ions.Comment: Research pape
Matryoshka Phonon Twinning in alpha-GaN
Understanding lattice dynamics is crucial for effective thermal management in
high-power electronic devices because phonons dominate thermal transport in
most semiconductors. This study utilizes complementary inelastic X-ray and
neutron scattering techniques and reports the temperature-dependent phonon
dynamics of alpha-GaN, one of the most important third-generation power
semiconductors. A prominent Matryoshka phonon dispersion is discovered with the
scattering tools and confirmed by the first-principles calculations. Such
Matryoshka twinning throughout the three-dimension reciprocal space is
demonstrated to amplify the anharmonicity of the related phonon modes through
creating abundant three-phonon scattering channels and cutting the phonon
lifetime of affected modes by more than 50%. Such phonon topology effectively
contributes to the reduction of the in-plane thermal transport, thus the
anisotropic thermal conductivity of alpha-GaN. The results not only have
significant implications for engineering the thermal performance and other
phonon-related properties of alpha-GaN, but also offer valuable insights on the
role of anomalous phonon topology in thermal transport of other technically
important semiconductors.Comment: 34 pages, 15 figure
Frustration-induced diffusive scattering anomaly and dimension change in
Magnetic frustration, arising from the competition of exchange interactions,
has received great attention because of its relevance to exotic quantum
phenomena in materials. In the current work, we report an unusual
checkerboard-shaped scattering anomaly in , far from the known
incommensurate magnetic satellite peaks, for the first time by inelastic
neutron scattering. More surprisingly, such phenomenon appears as spin dynamics
at low temperature, but it becomes prominent above N\'eel transition as elastic
scattering. A new model Hamiltonian that includes an intraplane next-nearest
neighbor was proposed and attributes such anomaly to the near-perfect magnetic
frustration and the emergence of unexpected two-dimensional magnetic order in
the quasi-one-dimensional .Comment: 24 pages, 10 figure
CodeLabeller: A Web-based Code Annotation Tool for Java Design Patterns and Summaries
With the rise of AI in SE, researchers have shown how AI can be applied to
assist software developers in a wide variety of activities. However, it has not
been accompanied by a complementary increase in labelled datasets, which is
required in many supervised learning methods. Several studies have been using
crowdsourcing platforms to collect labelled training data in recent years.
However, research has shown that the quality of labelled data is unstable due
to participant bias, knowledge variance, and task difficulty. Thus, we present
CodeLabeller, a web-based tool that aims to provide a more efficient approach
in handling the process of labelling Java source files at scale by improving
the data collection process throughout, and improving the degree of reliability
of responses by requiring each labeller to attach a confidence rating to each
of their responses. We test CodeLabeller by constructing a corpus of over a
thousand source files obtained from a large collection of opensource Java
projects, and labelling each Java source file with their respective design
patterns and summaries. Apart from assisting researchers to crowdsource a
labelled dataset, the tool has practical applicability in software engineering
education and assists in building expert ratings for software artefacts. This
paper discusses the motivation behind the creation of CodeLabeller, the
intended users, a tool demonstration and its UI, its implementation, benefits,
and lastly, the evaluation through a user study and in-practice usage.Comment: 4 pages, 4 figure
Mutual spin-phonon driving effects and phonon eigenvector renormalization in nickel (II) oxide
The physics of mutual interaction of phonon quasiparticles with electronic spin degrees of freedom, leading to unusual transport phenomena of spin and heat, has been a subject of continuing interests for decades. Despite its pivotal role in transport processes, the effect of spin-phonon coupling on the phonon system, especially acoustic phonon properties, has so far been elusive. By means of inelastic neutron scattering and first-principles calculations, anomalous scattering spectral intensity from acoustic phonons was identified in the exemplary collinear antiferromagnetic nickel (II) oxide, unveiling strong spin-lattice correlations that renormalize the polarization of acoustic phonon. In particular, a clear magnetic scattering signature of the measured neutron scattering intensity from acoustic phonons is demonstrated by its momentum transfer and temperature dependences. The anomalous scattering intensity is successfully modeled with a modified magneto-vibrational scattering cross-section, suggesting the presence of spin precession driven by phonon. The renormalization of phonon eigenvector is indicated by the observed "geometry-forbidden" neutron scattering intensity from transverse acoustic phonon. Importantly, the eigenvector renormalization cannot be explained by magnetostriction but instead, it could result from the coupling between phonon and local magnetization of ions
Differential Expression Pattern of Goat Uterine Fluids Extracellular Vesicles miRNAs during Peri-Implantation
Early pregnancy failure occurs when a mature embryo attaches to an unreceptive endometrium. During the formation of a receptive endometrium, extracellular vesicles (EVs) of the uterine fluids (UFs) deliver regulatory molecules such as small RNAs to mediate intrauterine communication between the embryo and the endometrium. However, profiling of small RNAs in goat UFs’ EVs during pregnancy recognition (day 16) has not been carried out. In this study, EVs were isolated from UFs on day 16 of the estrous cycle or gestation. They were isolated by Optiprep™ Density G radient (ODG) and verified by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blotting. Immunostaining demonstrated that CD63 was present both in the endometrial epithelium and glandular epithelium, and stain intensity was greater in the pregnant endometrium compared to the non-pregnant endometrium. Small RNA sequencing revealed that UFs’ EVs contained numerous sRNA families and a total of 106 differentially expressed miRNAs (DEMs). Additionally, 1867 target genes of the DEMs were obtained, and miRNA–mRNA interaction networks were constructed. GO and KEGG analysis showed that miRNAs were significantly associated with the formation of a receptive endometrium and embryo implantation. In addition, the fluorescence in situ hybridization assay (FISH) showed that chi-miR-451-5p was mainly expressed in stromal cells of the endometrium and a higher level was detected in the endometrial luminal epithelium in pregnant states. Moreover, the dual-luciferase reporter assay showed that chi-miR-451-5p directly binds to PSMB8 and may play an important role in the formation of a receptive endometrium and embryo implantation. In conclusion, these results reveal that UFs’ EVs contain various small RNAs that may be vital in the formation of a receptive endometrium and embryo implantation
Tantalum Particles Induced Cytotoxic and Inflammatory Effects in Human Monocytes
The aim of this study is to evaluate the biological safety of tantalum (Ta) particles and to further explore the effects of Ta particles on human monocyte toxicity and inflammatory cytokine expression. Human monocyte leukemia (THP-1) cells were cultured with Ta and hydroxyapatite (HA) particles. Cell counting kit-8 method was used to evaluate the cytotoxicity of Ta and HA particles. The apoptosis effects were evaluated by flow cytometry, and the protein expression levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were evaluated by ELISA. The protein levels of inflammation-related signaling pathways including nuclear factor-kappa B (NF-κB) and extracellular regulated kinase (ERK) were detected by western blotting. The cytotoxicity test showed that the toxicity level of Ta in vitro was grade l, which is within the clinically acceptable range. Compared with the HA control, Ta had no significant effect on THP-1 cell apoptosis, IL-6, and TNF-α release. The phosphorylated levels of NF-κB and ERK at 3 h in the Ta group were lower than those in the HA and control groups (P<0.001 both). These results reveal Ta particles behave good biosafety properties and provide some new insights for the future clinical use of Ta