757 research outputs found

    Dynamic Island Model based on Spectral Clustering in Genetic Algorithm

    Full text link
    How to maintain relative high diversity is important to avoid premature convergence in population-based optimization methods. Island model is widely considered as a major approach to achieve this because of its flexibility and high efficiency. The model maintains a group of sub-populations on different islands and allows sub-populations to interact with each other via predefined migration policies. However, current island model has some drawbacks. One is that after a certain number of generations, different islands may retain quite similar, converged sub-populations thereby losing diversity and decreasing efficiency. Another drawback is that determining the number of islands to maintain is also very challenging. Meanwhile initializing many sub-populations increases the randomness of island model. To address these issues, we proposed a dynamic island model~(DIM-SP) which can force each island to maintain different sub-populations, control the number of islands dynamically and starts with one sub-population. The proposed island model outperforms the other three state-of-the-art island models in three baseline optimization problems including job shop scheduler problem, travelling salesmen problem and quadratic multiple knapsack problem.Comment: 8 page

    Herpes Simplex Virus Type 2 Immediate Early Protein ICP27 Inhibits IFN-β Production in Mucosal Epithelial Cells by Antagonizing IRF3 Activation.

    Get PDF
    Herpes simplex virus type 2 (HSV-2) is the main cause of genital herpes and infections are common in the lower genital tract. Although neuronal and immune cells can be infected, epithelial cells, and keratinocytes are the primary HSV-2 target cells. HSV-2 establishes latency by evading the host immune system and its infection can also increase the risk of HIV-1 sexual transmission. Our pervious study found that HSV-2 immediate early protein ICP22, inhibited IFN-β production by interfering with the IRF3 pathway. However, ICP22-null HSV-2 did not completely lose the capability of suppressing IFN-β induction, suggesting the involvement of other viral components in the process. In this study, by using an ex vivo cervical explant model, we first demonstrated that HSV-2 can indeed inhibit IFN-β induction in human mucosal tissues. We further identified HSV-2 immediate early protein ICP27 as a potent IFN-β antagonist. ICP27 significantly suppresses the Sendai virus or polyinosinic-polycytidylic acid-induced IFN-β production in human mucosal epithelial cells, showing that ICP27 inhibits the IFN-β promoter activation, and IFN-β production at both mRNA and protein levels. Additional studies revealed that ICP27 directly associates with IRF3 and inhibits its phosphorylation and nuclear translocation, resulting in the inhibition of IFN-β induction. Our findings provide insights into the molecular mechanism underlying HSV-2 mucosal immune evasion, and information for the design of HSV-2 mucosal vaccines

    Development of a Simple Remote Sensing EvapoTranspiration model (Sim-ReSET): Algorithm and model test

    Get PDF
    Remote sensing (RS) has been considered as the most promising tool for evapotranspiration (ET) estimations from local, regional to global scales. Many studies have been conducted to estimated ET using RS data, however, most of them are based partially on ground observations. In this study, we developed a new dual-source Simple Remote Sensing EvapoTranspiration model (Sim-ReSET) based only on RS data. One merit of this model is that the calculation of aerodynamic resistance can be avoided by means of a reference dry bare soil and an assumption that wind speed at the upper boundary of atmospheric surface layer is homogenous, but the aerodynamic characters are still considered by means of canopy height. The other merit is that all inputs (net radiation, soil heat flux, canopy height, variables related to land surface temperature) can be potentially obtained from remote sensing data, which allows obtaining regular RS-driven ET product. For the purposes of sensitivity analysis and performance evaluation of the Sim-ReSET model without the effect of potential uncertainties and errors from remote sensing data, the Sim-ReSET model was tested only using intensive ground observations at the Yucheng ecological station in the North China Plain from 2006 to 2008. Results show that the model has a good performance for instantaneous ET estimations with a mean absolute difference (MAD) of 34.27 W/m2 and a root mean square error (RMSE) of 41.84 W/m2 under neutral or near-neutral atmospheric conditions. On 12 cloudless days, the MAD of daily ET accumulated from instantaneous estimations is 0.26 mm/day, and the RMSE is 0.30 mm/day

    Two- and three-dimensional study of the Kelvin-Helmholtz instability, magnetic reconnection and their mutual interaction at the magnetospheric boundary

    Get PDF
    Thesis (Ph.D.) University of Alaska Fairbanks, 1997Magnetic reconnection and the Kelvin-Helmholtz (KH) instability regulate the transport of magnetic flux, plasma, momentum and energy from the solar wind into the magnetosphere. In this thesis, I use two-dimensional and three-dimensional MHD simulations to investigate the KH instability, magnetic reconnection, and their relationship. Two basic flow and magnetic field configurations are distinguished at the Earth's magnetopause: (1) configurations where the difference in plasma velocity between the two sides of the boundary Δ\Deltav (velocity shear) is parallel to the difference of the magnetic field Δ\Deltab (magnetic shear), and (2) configurations where the velocity shear is perpendicular to the magnetic shear. For configuration (1), either magnetic reconnection is modified by the shear flow, or the KH instability is modified by the magnetic shear and resistivity. The evolution of the basic configuration (2) requires three dimensions. In this case, both processes can operate simultaneously in different planes. If the KH instability grows faster initially, it can wrap up the current layer and thereby initiate a very fast and turbulent reconnection process. The resulting magnetic turbulence can provide the first explanation of often very turbulent structures of the magnetopause current layer. For the first time, it is quantitatively confirmed that the KH instability operates at the magnetospheric boundary at low latitudes

    The Effect of Harsh Parenting on Smartphone Addiction of Adolescents

    Get PDF
    Based on the questionnaire statistical results of 3219 students from two non-boarding key secondary schools from Wuhan and Shiyan, the study published in Psychological Development and Education Research established the mediation effect model, regulating effect model, and intermediary effect model with regulation to explore the mediating effect of core self-evaluation in the process of smartphone addiction through harsh parenting among adolescents, and also the regulating effect of friendship quality

    Technoference and Adolescent Internet Gaming Addiction: The Mediating Role of the Need to Belong and the Moderating Role of Friendship Quality

    Get PDF
    Internet gaming, a product of information technology, has become an essential part of adolescents’ lives. While a moderate amount of online gaming helps improve their life satisfaction and promote their pro-social behavior, the Internet gaming addiction can lead to various mental problems among them. This study constructed a moderated mediation model based on the problem behavior theory and the individual-environment interaction models to examine the effects of technoference, the need to belong, and friendship quality on adolescent Internet gaming addiction

    Herpes Simplex Virus Type 2 Infection-Induced Expression of CXCR3 Ligands Promotes CD4(+) T Cell Migration and Is Regulated by the Viral Immediate-Early Protein ICP4

    Get PDF
    HSV-2 infection-induced CXCR3 ligands are important for the recruitment of virus-specific CD8+ T cells, but their impact on CD4+ T cell trafficking remains to be further determined. Given that recruitment of CD4+ T cells to infection areas may be one of the mechanisms that account for HSV-2 infection-mediated enhancement of HIV-1 sexual transmission, here we investigated the functionality of HSV-2 infection-induced CXCR3 ligands CXCL9, CXCL10, and CXCL11 in vivo and in vitro, and determined the viral components responsive for such induction and the underlying mechanisms. We first found that the expression of CXCR3 ligands CXCL9, CXCL10, and CXCL11 was increased in mice following vaginal challenge with HSV-2, while CXCL9 played a predominant role in the recruitment of CD4+ T cells to the vaginal foci of infected mice. HSV-2 infection also induced the production of CXCL9, CXCL10, and CXCL11 in human cervical epithelial cells. Of note, although HSV-2 induced the expression of all the three CXCR3 ligands, the induced CXCL9 appeared to play a predominant role in promoting CD4+ T cell migration, reflecting that the concentrations of CXCL10 and CXCL11 required for CD4+ T cell migration are higher than that of CXCL9. We further revealed that, ICP4, an immediate-early protein of HSV-2, is crucial in promoting CXCR3 ligand expression through the activation of p38 MAPK pathway. Mechanistically, ICP4 binds to corresponding promoters of CXCR3 ligands via interacting with the TATA binding protein (TBP), resulting in the transcriptional activation of the corresponding promoters. Taken together, our study highlights HSV-2 ICP4 as a vital viral protein in promoting CXCR3 ligand expression and CXCL9 as the key induced chemokine in mediating CD4+ T cell migration. Findings in this study have shed light on HSV-2 induced leukocyte recruitment which may be important for understanding HSV-2 infection-enhanced HIV-1 sexual transmission and the development of intervention strategies

    Identification of anthropogenic parameters for a regional nitrogen balance model via field investigation of six ecosystems in China

    Get PDF
    To evaluate the impact of human behavior (with regard food consumption, waste disposal and farming method) on nitrogen flow, a field investigation was conducted in six typical ecosystems in China. A number of parameters for regional nitrogen balance models were identified during the investigation. The results show that the average per-capita daily protein intake is 107 g. While there is an insignificant difference in total protein intake among the different ecosystems, protein intake from all food groups, except for eggs, is significantly different (P a parts per thousand currency sign 0.05). Differences in diet, along with those in socio-economic conditions, reflect differences in the characteristics of the ecosystems. Regarding per-capita annual potential nitrogen loading from human excrement, a considerable difference exists between the urban rich and the rural poor. In urban areas, approximately 1.02 kg N is returned to farmlands and 5.49 kg N is directly discharged into rivers. In rural regions, on the other hand, approximately 4.33 kg N is returned to farmlands and 1.60 kg N is directly discharged into rivers. Furthermore, urea and mixed fertilizers constitute the most common chemical fertilizers in the study area. Fertilizer diversification is practiced in a range of agricultural lands, paddy-fields and irrigated plains. In the oasis and paddy-field agricultural systems, many of the agricultural by-products (e.g., straw) are burned or mixed with base-fertilizers and plowed into the soil. In irrigated agricultural systems, over 70% of agricultural by-products are recycled as livestock feed. In most instances, livestock excrement is directly reduced in the pasturelands or reused in the fields as manure. Occasionally, as in the case of large-scale breeding, excrements are usually abandoned

    DC-SIGN promotes Japanese encephalitis virus transmission from dendritic cells to T cells via virological synapses.

    Get PDF
    Skin-resident dendritic cells (DCs) likely encounter incoming viruses in the first place, and their migration to lymph nodes following virus capture may promote viral replication. However, the molecular mechanisms underlying these processes remain unclear. In the present study, we found that compared to cell-free viruses, DC-bound viruses showed enhanced capture of JEV by T cells. Additionally, JEV infection was increased by co-culturing DCs and T cells. Blocking the C-type lectin receptor DC-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) with neutralizing antibodies or antagonists blocked JEV transmission to T cells. Live-cell imaging revealed that DCs captured and transferred JEV viral particles to T cells via virological synapses formed at DC-T cell junctions. These findings indicate that DC-SIGN plays an important role in JEV transmission from DCs to T cells and provide insight into how JEV exploits the migratory and antigen-presenting capabilities of DCs to gain access to lymph nodes for dissemination and persistence in the host
    corecore