117 research outputs found
Synchronization from Second Order Network Connectivity Statistics
We investigate how network structure can influence the tendency for a neuronal network to synchronize, or its synchronizability, independent of the dynamical model for each neuron. The synchrony analysis takes advantage of the framework of second order networks, which defines four second order connectivity statistics based on the relative frequency of two-connection network motifs. The analysis identifies two of these statistics, convergent connections, and chain connections, as highly influencing the synchrony. Simulations verify that synchrony decreases with the frequency of convergent connections and increases with the frequency of chain connections. These trends persist with simulations of multiple models for the neuron dynamics and for different types of networks. Surprisingly, divergent connections, which determine the fraction of shared inputs, do not strongly influence the synchrony. The critical role of chains, rather than divergent connections, in influencing synchrony can be explained by their increasing the effective coupling strength. The decrease of synchrony with convergent connections is primarily due to the resulting heterogeneity in firing rates
Upregulation of CD94 on CD8+T Cells in Anterior Chamber-Associated Immune Deviation
<p>Abstract</p> <p>Background</p> <p>CD8<sup>+ </sup>regulatory T cells (Treg) have been considered to be involved in a model of ocular-induced tolerance, known as anterior chamber-associated immune deviation (ACAID). The phenotype and characteristics of CD8<sup>+</sup>Treg in ACAID remain only poorly understood. Recent studies have reported that the CD94-Qa-1 system is implicated in the induction of ACAID CD8<sup>+</sup>Treg, but the functions and characteristics of CD8<sup>+</sup>CD94<sup>+</sup>T cells remain unclear.</p> <p>Results</p> <p>Both mRNA and protein of CD94 and NKG2A were markedly up-regulated on splenic CD8<sup>+</sup>T cells of ACAID mice compared with controls. Flow cytometric analysis showed that very few CD8<sup>+</sup>CD94<sup>+</sup>T cells express granzyme B, perforin and Foxp3. CD8<sup>+</sup>CD94<sup>+</sup>T cells, but not CD8<sup>+</sup>CD94<sup>-</sup>T cells, magnetically isolated from the spleens of ACAID mice, produced large amounts of TGF-beta1 and exhibited suppressive activity in vitro. Neutralization of TGF-beta1 caused reversal of suppression mediated by CD8<sup>+</sup>CD94<sup>+</sup>T cells.</p> <p>Conclusion</p> <p>CD8<sup>+</sup>CD94<sup>+</sup>T cells from ACAID mice exhibited suppressive activity in association with enhanced expression of TGF-beta1, suggesting that CD8<sup>+</sup>Treg are mainly distributed in CD94<sup>+</sup>T cell subpopulations.</p
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Tuberculosis burden in China: a high prevalence of pulmonary tuberculosis in household contacts with and without symptoms
Background: In the context of decreasing tuberculosis prevalence in China, we examined the effectiveness of screening household contacts of tuberculosis patients. Methods: A tuberculosis survey was conducted in 2008. All 3,355 household contacts of notified tuberculosis cases were examined with a questionnaire interview, chest X-ray and three sputum smear tests. The effectiveness was examined by comparing the prevalence of pulmonary tuberculosis in household contacts with or without presenting clinical symptoms against the respective notification rates. Regression models were used to evaluate the factors associated with pulmonary tuberculosis. Results: Of the 3,355 household contacts, 92 members (2.7%) had pulmonary tuberculosis, among which 46 cases were asymptomatic. The prevalence of pulmonary tuberculosis and smear positive cases in household contacts without symptoms were 20 and 7 times higher than the notification rates in 2008, while those in household contacts with symptoms were 247 and 108 times higher than notification rates, respectively. The patients detected were mainly Index Cases’ spouses, sisters/brothers and those who were in contact with female Index Cases. Conclusions: The present study provides convincing evidence that household contacts of notified tuberculosis cases are at higher risk of developing tuberculosis. Routine screening for household contacts without any symptoms is recommended for sustained tuberculosis control in China as well as in the world
(1E,2E)-N1,N2-Bis(5′-methyl-[1,1′:3′,1′′-terphenyl]-4′-yl)acenaphthylene-1,2-diimine unknown solvent
The title compound, C50H36N2, synthesized by the condensation reaction of 2-methyl-4,6-diphenylaniline and acenaphthylene-1,2-dione, crystallizes with two independent molecules (A and B) in the asymmetric unit. The two molecules differ essentially in the orientation of the phenyl ring at position 3′ of the terphenyl group with respect to the central ring of this unit. In molecule A this dihedral angle is 16.68 (14)°, while in molecule B the corresponding angle is 33.10 (16)°. The three-fused-ring 1,2-dihydroacenaphthylene units are planar in each molecule; r.m.s. deviation of 0.025 Å in molecule A and 0.017 Å in molecule B. The central rings of the terphenyl groups are almost normal to the mean plane of the three-fused-ring units with dihedral angles of 79.43 (12) and 82.66 (13)° in molecule A and 88.99 (13) and 87.98 (12)° in molecule B. In the crystal, the two molecules are linked via a C—H...N hydrogen bond. These A–B units are linked by a pair of C—H...π interactions, forming a four-molecule unit located about an inversion center. These four-molecule units are linked by weak π–π interactions [most significant intercentroid distance = 3.794 (2) Å], forming columns along direction [010]. A region of disordered electron density was corrected for using the SQUEEZE routine in PLATON [Spek (2015). Acta Cryst. C71, 9–18]. The formula mass and unit-cell characteristics of this unknown solvent were not be taken into account during the refinement
Security Situation Prediction of Network Based on Lstm Neural Network
Part 2: AIInternational audienceAs an emerging technology that blocks network security threats, network security situation prediction is the key to defending against network security threats. In view of the single source of information and the lack of time attributes of the existing methods, we propose an optimal network security situation prediction model based on lstm neural network. We employ the stochastic gradient descent method as the minimum training loss to establish a network security situation prediction model, and give the model implementation algorithm pseudo code to further predict the future network security situation. The simulation experiments based on the data collected from Security Data dataset show that compared with other commonly used time series methods, the prediction accuracy of the model is higher and the overall situation of network security situation is more intuitively reflected, which provides a new solution for network security situation
Removal of Heavy Metals from Urban Stormwater Runoff Using Bioretention Media Mix
Heavy metals from urban stormwater runoff are important sources of surface water pollutants. Sand, zeolite, sandy loam, and quartz-sand were separately mixed with lignin to form four bioretention media mixes for experimental study using synthetic stormwater runoff. The average removal efficiencies of four heavy metals (Cu, Zn, Cd, and Pb) by the four media mixes were all better than 97% at the optimum pH of 6.05 (ranging from 6 to 8) and the seven-day rainfall-event interval. The influence of the influent concentration and the rainfall-event interval on the removal efficiency of heavy metals by the four media mixes was not significant, but the variation of the removal efficiencies at the four-day rainfall-event interval was large. Under acidic conditions, there was a certain heavy metal dissolution in the four reactors, but the effect on the removal efficiency was minor. Heavy metals were present in the media mainly in the form of the residual fraction (>50%). The accumulation of Cu, Zn, and Cd in the surface planting-soil layer (same humus and sandy-loam mixture for all reactors) was significantly larger than the accumulation at deeper depths but not for Pb. Overall, the heavy metal removal efficiencies by the four media mixes were not significantly different, and the choice of the planting-soil layer can become the control factor of heavy metal removal
High-quality chromosome-level scaffolds of the plant bug Pachypeltis micranthus provide insights into the availability of Mikania micrantha control
Abstract Background The plant bug, Pachypeltis micranthus Mu et Liu (Hemiptera: Miridae), is an effective potential biological control agent for Mikania micrantha H.B.K. (Asteraceae; one of the most notorious invasive weeds worldwide). However, limited knowledge about this species hindered its practical application and research. Accordingly, sequencing the genome of this mirid bug holds great significance in controlling M. micrantha. Results Here, 712.72 Mb high-quality chromosome-level scaffolds of P. micranthus were generated, of which 707.51 Mb (99.27%) of assembled sequences were anchored onto 15 chromosome-level scaffolds with contig N50 of 16.84 Mb. The P. micranthus genome had the highest GC content (42.43%) and the second highest proportion of repetitive sequences (375.82 Mb, 52.73%) than the three other mirid bugs (i.e., Apolygus lucorum, Cyrtorhinus lividipennis, and Nesidiocoris tenuis). Phylogenetic analysis showed that P. micranthus clustered with other mirid bugs and diverged from the common ancestor approximately 200 million years ago. Gene family expansion and/or contraction were analyzed, and significantly expanded gene families associated with P. micranthus feeding and adaptation to M. micrantha were manually identified. Compared with the whole body, transcriptome analysis of the salivary gland revealed that most of the upregulated genes were significantly associated with metabolism pathways and peptidase activity, particularly among cysteine peptidase, serine peptidase, and polygalacturonase; this could be one of the reasons for precisely and highly efficient feeding by the oligophagous bug P. micranthus on M. micrantha. Conclusion Collectively, this work provides a crucial chromosome-level scaffolds resource to study the evolutionary adaptation between mirid bug and their host. It is also helpful in searching for novel environment-friendly biological strategies to control M. micrantha
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