A DEM upscaling method with integrating valley lines based on HASM

A new digital elevation model(DEM)upscaling method based on high accuracy surface modeling(HASM)is proposed by combining the elevation information of DEM and the valley lines extracted from DEM with different flow accumulation thresholds.The proposed method has several advantages over traditional DEM upscaling methods.First,the HASM ensures the smoothness of the upscaled DEM.Secondly,several DEMs with different topographic details can be obtained using the same DEM grid size by incorporating the valley lines with different flow accumulation thresholds.The Jiuyuangou watershed in China’s Loess Plateau was used as a case study.A DEM with a grid size of 5 m obtained from the local surveying and mapping department was used to verify the proposed DEM upscaling method.We established the surface complexity index to describe the complexity of the topographic surface and quantified the differences in the topographic features obtained from different upscaling results.The results show that topography becomes more generalized as grid size and flow accumulation threshold increase.At a large DEM grid size,an increase in the flow accumulation threshold increases the difference in elevation values in different grids,increasing the surface complexity index.This study provides a new DEM upscaling method suitable for quantifying topography.

The Method of Polynomial Particular Solutions for Solving Nonlinear Poisson-Type Equations

In this paper,the method of polynomial particular solutions is used to solve nonlinear Poisson-type partial differential equations in one,two,and three dimensions.The condition number of the coefficient matrix is reduced through the implementation of multiple scale technique,ultimately yielding a stable numerical solution.The methodological process can be divided into two main parts:first,identifying the corresponding polynomial particular solutions for the linear differential operator terms in the governing equations,and second,employing these polynomial particular solutions as basis function to iteratively solve the remaining nonlinear terms within the governing equations.Additionally,we investigate the potential improvement in numerical accuracy for equations with singularities in the analytical solution by shifting the computational domain a certain distance.Numerical experiments are conducted to assess both the accuracy and stability of the proposed method.A comparison of the obtained results with those produced by other numerical methods demonstrates the accuracy,stability,and efficiency of the proposed method in handling nonlinear Poisson-type partial differential equations.

强迫症患者额顶叶网络信息整合与分离功能特点

目的探讨强迫症患者脑网络节点信息整合与分离的功能改变及其与临床症状的相关性。方法纳入符合入组标准的56例强迫症患者(强迫症组)和56例性别、年龄、受教育年限相匹配的健康对照(对照组)。每个纳入研究的对象都进行静息态全脑功能磁共振成像扫描, 并采用耶鲁-布朗强迫量表(Yale-Brown Obsessive Compulsive Scale, Y-BOCS)评估强迫症组的临床症状。基于图论方法分析和独立样本t检验比较2组间节点功能网络拓扑属性的差异, 并采用偏相关分析探讨差异脑区属性值与临床症状的相关性。结果与对照组相比, 强迫症组左侧颞上回喙部、右侧中央后回干部的全局效率降低, 最短路径长度增大(均为P<0.001, FDR校正);左侧额下回背侧区的局部效率(P=0.002, 未校正)和聚类系数降低(P<0.001, FDR校正);进一步分析发现, 强迫症组左侧颞上回喙部的全局效率值与强迫思维因子分呈正相关(r=0.390, P=0.005), 左侧颞上回喙部的最短路径长度值与强迫思维因子分呈负相关(r=-0.359, P=0.010)。结论强迫症患者额顶叶网络(额下回、中央后回)信息整合与分离功能失调;颞上回喙部信息整合功能异常降低, 且颞上回喙部的全局效率越高、最短路径长度越短, 强迫思维越严重。

IL-21 accelerates xenogeneic graft-versus-host disease correlated with increased B-cell proliferation

Graft-versus-host disease(GVHD)is a prevalent and potential complication of hematopoietic stem cell trans-plantation.An animal model,xenogeneic GVHD(X-GVHD),that mimics accurately the clinical presentation of GVHD would provide a tool for investigating the mechanism involved in disease pathogenesis.Murine models indi-cated that inhibiting IL-21 signaling was a good therapy to reduce GVHD by impairing T cell functions.We sought to investigate the effect of exogenous human IL-21 on the process of X-GVHD.In this study,human IL-21 was expressed by hydrodynamic gene delivery in BALB/c-Rag2−/−IL-2Rγc−/−(BRG)immunodeficient mice which were intravenously transplanted human peripheral blood mononuclear cells(hPBMCs).We found that human IL-21 exacerbated X-GVHD and resulted in rapid fatality.As early as 6 days after hPBMCs transplanted to BRG mice,a marked expansion of human CD19+B cells,but not T cells,was observed in spleen of IL-21-treated mice.Com-pared with control group,IL-21 induced robust immuno-globulin secretion,which was accompanied by increased accumulation of CD19+CD38high plasma cells in spleen.In addition,we demonstrated that B-cell depletion was able to ameliorate X-GVHD.These results are the fi rst to fi nd in vivo expansion and differentiation of human B cells in response to IL-21,and reveal a correlation between the expansion of B cells and the exacerbation of xenogeneic GVHD.Our fi ndings show evidence of the involvement of B cells in X-GVHD and may have implications in the treat-ment of the disease.

Anti-TOSO antibody treatment promotes T cell activation-induced cell death(AICD) in vitro and in vivo

T cell activation-induced cell death(AICD),that involves the induction of Fas-mediated apoptosis,is very important for the maintenance of immune homeostasis.TOSO was firstly described as an inhibitor of Fasmediated apoptosis and overexpressed in chronic lymphocytic leukemia.Recently,TOSO was identified as IgM FcR.In this study,we produced anti-TOSO monoclonal antibody(mAb)that could block the binding of IgM to TOSO and found that T cell apoptosis is negatively correlated with TOSO expression during T cell activation.Treatment of activated T cells with anti-TOSO blocking mAb promoted T cell AICD in in vitro AICD model,and treatment of xenogeneic-GVHD mice with the antibody also increased the sensitivity of activated T cells to Fasinduced apoptosis,which was accompanied by reduction of c-FLIPL expression and up-regulation of AP-1 complex.In summary,our data indicate the anti-apoptotic effect of TOSO in T cell AICD and open up new therapeutic prospects for the treatment of hematologic malignancies and immune disorders.