Cooperative coordination in multi-agent systems has been a topic of interest in networked control theory in recent years. In contrast to cooperative agents, Byzantine agents in a network are capable ...to manipulate their data arbitrarily and send bad messages to neighbors, causing serious network security issues. This paper is concerned with resilient tracking consensus over a time-varying random directed graph, which consists of cooperative agents, Byzantine agents and a single leader. The objective of resilient tracking consensus is the convergence of cooperative agents to the leader in the presence of those deleterious Byzantine agents. We assume that the number and identity of the Byzantine agents are not known to cooperative agents, and the communication edges in the graph are dynamically randomly evolving. Based upon linear system analysis and a martingale convergence theorem, we design a linear discrete-time protocol to ensure tracking consensus almost surely in a purely distributed manner. Some numerical examples are provided to verify our theoretical results.
This paper studies interval consensus for switched multiagent systems over directed networks, which consist of a continuous-time subsystem and a discrete-time subsystem regulated by a switching rule. ...Interval consensus refers to a state constrained consensus, where each agent is allowed to propose an acceptable interval to saturate their expressed states and the final consensus state lies in the nonempty intersection of all these intervals. We establish conditions guaranteeing interval consensus for switched multiagent system under arbitrary switching rules. Furthermore, we introduce the scaled interval consensus notion, which allows both the convergence of states to a pre-assigned proportion and the scaled consensus values lying in the desired range. Simulation results are provided to verify the effectiveness of the theoretical results.
Interstitial solid strengthening is an effective strategy to harden metallic materials, however, it usually deteriorates the ductility. Here, we report that addition of carbon into the medium-entropy ...NiCoCr alloy successfully enhances the strength at no expense of ductility. It was found that up to 0.75 at.% carbon was completely solid-solutionized in (NiCoCr) 100-xCx (x = 0, 0.10, 0.25, 0.50 and 0.75 at.%) without formation of any carbides. With the increase of carbon content from 0 to 0.75 at.%, the yield and fracture strength were increased from 242 to 347 MPa to 727 and 862 MPa, respectively, whilst the ductility kept as high as about 75%. It is noteworthy that the integral of the stress over strain for the alloy with 0.75 at.% carbon reaches a value of 59 GPa %, surmounting the level of many reported multi-principal elements alloys. Our analysis indicates that carbon addition increases stacking fault energy, thus delaying occurrence of twinning and decreasing the thickness of twin lamellas. At the early deformation stage, carbon decreases the stress localization and stimulates dislocation multiplication. After occurrence of deformation twinning, finer twinning structure in the alloys added with carbon not only can obstacle and trigger more dislocations, but also transfer plastic deformation more efficiently, thus promoting the twinning process, postponing the plastic instability and eventually giving rise to a more pronounced work-hardening. Our results not only have important implications for understanding the solid solution strengthening mechanism in medium-entropy alloys, but also shed lights on developing advanced metallic alloys with a unique combination of strength and ductility.
Display omitted
•Addition of carbon into NiCoCr simultaneously increase the strength and ductility.•Carbon homogenizes the dislocation substructure and promotes uniform deformation.•Carbon addition increases the stacking fault energy.•Carbon addition delays occurrence of twinning and homogenizes plastic deformation.
Impaired executive function (EF) is suggested to be one of the core features in individuals with autism spectrum disorders (ASD); however, little is known about whether the extent of worse EF in ASD ...than typically developing (TD) controls is age-dependent. We used age-stratified analysis to reveal this issue.
We assessed 111 youths with ASD (aged 12.5 ± 2.8 years, male 94.6%) and 114 age-, and sex-matched TD controls with Digit Span and four EF tasks of the Cambridge Neuropsychological Test Automated Battery (CANTAB): Spatial Span (SSP), Spatial Working Memory (SWM), Stockings of Cambridge (SOC), and Intradimensional/Extradimensional Shift Test (I/ED).
Compared to TD controls, youths with ASD performed poorer on the Digit Span, SWM, SOC, and I/ED tasks. The performance of all the tasks improved with age for both groups. Age-stratified analyses were conducted due to significant age × group interactions in visuospatial planning (SOC) and set-shifting (I/ED) and showed that poorer performance on these two tasks in ASD than TD controls was found only in the child (aged 8-12 years) rather than the adolescent (aged 13-18 years) group. By contrast, youths with ASD had impaired working memory, regardless of age. The increased magnitude of group difference in visuospatial planning (SOC) with increased task demands differed between the two age groups but no age moderating effect on spatial working memory.
Our findings support deficits in visuospatial working memory and planning in youths with ASD; however, worse performance in set-shifting may only be demonstrated in children with ASD.
Chemotherapy is an important treatment modality for gastric cancer (GC); however, it usually fails because of drug resistance, especially multidrug resistance (MDR). Previously, we found a novel ...subset of MDR-associated microRNAs (miRNAs) through high-throughput functional screening. In this report, we investigated the exact roles and mechanisms of miR-23b-3p in the MDR of GC. Using gain or loss-of-function in in vitro and in vivo experiments, we found that overexpression of miR-23b-3p reversed cancer cell resistance to multiple chemotherapeutics in vitro and sensitize tumors to chemotherapy in vivo. Reporter gene assay and western blot analysis showed that ATG12 and HMGB2 were the direct targets of miR-23b-3p. Meanwhile, ATG12 and HMGB2 were positively associated with the occurrence of autophagy. Reducing the expression of these target genes by siRNA or inhibition of autophagy both sensitized GC cells to chemotherapy. These findings suggest that a miR-23b-3p/ATG12/HMGB2/autophagy-regulatory loop has a critical role in MDR in GC. In addition, miR-23b-3p could be used as a prognostic factor for overall survival in GC. In conclusion, our data demonstrated that miR-23b-3p inhibited autophagy mediated by ATG12 and HMGB2 and sensitized GC cells to chemotherapy, and suggested the potential application of miR-23b-3p in drug resistance prediction and treatment.
Metal–organic frameworks (MOFs)-based electrode materials have drawn wide interest in energy storage applications. Herein, a nickel-based metal–organic framework (Ni-MOF) has been synthesized by ...simple hydrothermal reaction with different reaction times. The hydrothermal reaction time has an impact on the energy storage performance of the synthesized material. Structural characterization confirms the layered structure and purity of the synthesized Ni-MOF. Significantly, improved energy storage performance was found for the Ni-MOF prepared under reaction time 30 h as compared to other reaction times. It exhibits the highest specific capacity of 1498.6 F/g at a current density of 1 A/g along with good rate of capability. This investigation provides useful approach to improve the capacitive performance of MOF-based electrode materials.
Increased intra-individual variability (IIV) in reaction time (RT) across various tasks is one ubiquitous neuropsychological finding in attention deficit hyperactivity disorder (ADHD). However, ...neurobiological underpinnings of IIV in individuals with ADHD have not yet been fully delineated. The ex-Gaussian distribution has been proved to capture IIV in RT. The authors explored the three parameters μ (mu), σ (sigma), τ (tau) of an ex-Gaussian RT distribution derived from the Conners' continuous performance test (CCPT) and their correlations with the microstructural integrity of the frontostriatal-caudate tracts and the cingulum bundles.
We assessed 28 youths with ADHD (8-17 years; 25 males) and 28 age-, sex-, IQ- and handedness-matched typically developing (TD) youths using the CCPT, Wechsler Intelligence Scale for Children, 3rd edition and magnetic resonance imaging (MRI). Microstructural integrity, indexed by generalized fractional anisotropy (GFA), was measured by diffusion spectrum imaging tractrography on a 3-T MRI system.
Youths with ADHD had larger σ (s.d. of Gaussian distribution) and τ (mean of exponential distribution) and reduced GFA in four bilateral frontostriatal tracts. With increased inter-stimulus intervals of CCPT, the magnitude of greater τ in ADHD than TD increased. In ADHD youths, the cingulum bundles and frontostriatal integrity were associated with three ex-Gaussian parameters and with μ (mean of Gaussian distribution) and τ, respectively; while only frontostriatal GFA was associated with μ and τ in TD youths.
Our findings suggest the crucial role of the integrity of the cingulum bundles in accounting for IIV in ADHD. Involvement of different brain systems in mediating IIV may relate to a distinctive pathophysiological processing and/or adaptive compensatory mechanism.
•New nasal cavity model combined with realistic facial features and environment.•Micron-particle deposition visualized with improved 2D surface mapping technique.•Influence of the external nose and ...breathing zone on the particle deposition.•Future studies should incorporate the external face and environment.
The breathing region connects the nasal cavity with the outside environmental air where flow is accelerated through the nostrils. Particles introduced into the nasal cavity without considering the breathing region neglect the influence of facial features and realistic boundary conditions at the nostrils. In this study, a new nasal cavity model is reconstructed combining facial features and an ambient environment focusing on the breathing region. The inhaled air from outside the nose is investigated and compared with a model that consists of the nasal cavity alone. An improved 2D surface mapping technique is applied to the 3D nasal cavity to visualize the particle deposition patterns onto a planar geometry. Using this technique, deposition of micron particles from 0.4μm to 30μm were investigated, and trajectories of 2.5μm, 10μm and 20μm were compared with the ‘nasal-only’ case. Particle deposition efficiency curves and particle trajectories are plotted to show that the inclusion of the external nose and breathing region causes: (i) a change in the fluid flow within the anterior nasal cavity half but the flow patterns regulate in the posterior half; (ii) minimal difference for 2.5μm particle deposition patterns; (iii) significant differences in 10 and 20μm particle deposition patterns where more particles are deposited in the posterior nasal regions.
Tumor cells preferentially adopt aerobic glycolysis for their energy supply, a phenomenon known as the Warburg effect. It remains a matter of debate as to how the Warburg effect is regulated during ...tumor progression. Here, we show that CHIP (carboxyl terminus of Hsc70-interacting protein), a U-box E3 ligase, suppresses tumor progression in ovarian carcinomas by inhibiting aerobic glycolysis. While CHIP is downregulated in ovarian carcinoma, induced expression of CHIP results in significant inhibition of the tumor growth examined by in vitro and in vivo experiments. Reciprocally, depletion of CHIP leads to promotion of tumor growth. By a SiLAD proteomics analysis, we identified pyruvate kinase isoenzyme M2 (PKM2), a critical regulator of glycolysis in tumors, as a target that CHIP mediated for degradation. Accordingly, we show that CHIP regulates PKM2 protein stability and thereafter the energy metabolic processes. Depletion or knockout of CHIP increased the glycolytic products in both tumor and mouse embryonic fibroblast cells. Simultaneously, we observed that CHIP expression inversely correlated with PKM2 levels in human ovarian carcinomas. This study reveals a mechanism that the Warburg effect is regulated by CHIP through its function as an E3 ligase, which mediates the degradation of PKM2 during tumor progression. Our findings shed new light into understanding of ovarian carcinomas and may provide a new therapeutic strategy for ovarian cancer.
PDF
