采煤沉陷区土地利用变化及其景观异质性分析——以山西省东大煤矿为例

以山西省东大煤矿为例，对采煤沉陷区沉陷前后土地利用状况的变化以及景观异质性进行了初步研究。主要分析了不同土地利用类型斑块数量、面积的变化，以及景观破碎度、多样性、均匀度、优势度等指标。研究结果表明，采煤沉陷造成地表移动变形产生的裂隙、陷坑、塌方或滑坡等，致使土地被分割破碎，斑块数量增加而面积减小，植被毁坏，生态环境向着不合理的方向发展。     

青藏高原"黑土滩"退化草地植物和土壤对秃斑面积变化的响应

在青藏高原典型"黑土滩"区对93个秃斑块及周边的土壤和植被特征以及变化规律进行了调查分析.结果表明,高寒草地草毡层消失后形成的"黑土滩"秃斑在草地中形成一个"负肥力岛",秃斑块内土壤养分低于秃斑周边有草皮层覆盖的草地,其中全氮、铵态氮、有机碳差异显著;同时秃斑内pH显著高于秃斑块外水平.秃斑块是草地养分流失的通道.当秃...     

改进型中草药921合剂结合α-酮戊二酸对断奶大鼠肠道免疫的影响

研究了改进型中草药921合剂结合α 酮戊二酸(α ketoglutarate,AKG)作为饲料添加剂对体重为40.0±5g18日龄断奶大鼠小肠上皮淋巴集结数量、面积和十二指肠肠液中IgA的含量进行了测定。纯系断奶大白鼠被随机分为对照组、中草药组和中草药加AKG组,每组10只,分别饲喂1～2周,然后对上述内容进行研究。结果为:饲喂1周后,对照组、中草药组和中草药加AKG组小肠上皮淋巴结数量分别为16.4±1.23,14.2±0.63,15.1±0.68个(P>0.05);3组间十二指肠肠液中IgA含量分别为0.844±0.020,0.921±0.039,1.236±0.131g·L-1(P<0.01)。饲喂2周后对照组、中草药组和中草药加AKG组小肠上皮淋巴结数量分别为15.6±0.50,16.4±0.94,15.6±0.99个(P>0.05);3组间前段肠上皮淋巴集结面积分别为27.7±2.02,44.8±4.34,42.4±1.93mm2(P<0.01);中段分别为28.1±1.10,40.5±5.68,55.4±2.28mm2(P<0.01);后段分别为37.6±4.57,63.6±4.94,59.0±5.35mm2(P<0.01);3组间十二指肠肠液中IgA含量分别为0.256±0.015,0.493±0.030,0.601±0.047g·L-1(P<0.01)。中草药组和中草药加AKG组十二指肠IgA含量均显著高于对照组。研究表明:中草药结合AKG可以通过增加小肠上皮淋巴集结面积,增加肠道IgA的分泌,从而快速有效的改善肠道的生长和发育及黏膜     

Effects of oral supplementation with bovine colostrum on the immune system of weaned piglets

The aim of this study was to evaluate the influence of bovine colostrum supplementation on the immune system of weaned piglets in a context of a full ban of in-feed antibiotics. After weaning at 21 days, 24 outbred piglets were fed with a diet supplemented daily for three weeks with 0, 1 or 5 g of colostrum. Feed intake, growth performance, haematological parameters, and serum and local anti-colostrum immunoglobulin levels were examined. Lymphocytes from the blood, spleen, and gut-associated lymphoid were analysed for phenotype as well as for their ability to produce cytokines. The stimulation index (SI) of mononuclear cells from different organs was obtained after colostral or mitogenic stimulation. Feed intake, growth, and haematological parameters were not significantly affected by colostrum. Total serum IgA levels were increased after colostrum supplementation, with a transient decrease in total IgG. Local anti-colostrum immunization was observed in colostrum-fed piglets. The CD21+/CD3+ cells populations of the ileal Peyer's patch (iPP) were markedly affected. The SI of lymphocyte populations changed significantly whereas, naive blood lymphocytes were not stimulated in vitro in the presence of bovine colostrum, suggesting local anti-colostrum immunization and an absence of direct mitogenic effects of the colostrum. Both Th1 and Th2 cytokine production was present in the different organs of colostrum-fed piglets. Bovine colostrum especially stimulated iPP cells.     

Site-Specific Weed Control in Maize,Sugar Beet,Winter Wheat,and Winter Barley

A four-year study of site-specific weed control is presented in this paper. Weed seedling distribution was sampled and mapped prior to and after post-emergence herbicide application in four fields planted with maize, sugar beets, winter wheat and winter barley, rotating on one site. Herbicides and other weed control strategies were applied site-specifically according to the spatial variation of weed populations. Different decision algorithms were used for chemical weed control methods in each crop. A weed treatment map was created to direct location and dosage of herbicide application. The sprayer was coupled with a differential Global Positioning System (DGPS). The solenoid valves of the sprayer were opened automatically when the tractor entered a weed patch characterized in the weed treatment map. For site specific herbicide application, a patch sprayer was developed that allowed variable rate application and the selective control of each section of the spray boom.     

典型喀斯特山地城市镶嵌山体斑块格局时空变化特征

喀斯特山地城市镶嵌山体对生物多样性保护、生态系统健康稳定、生态系统服务具有重要的作用和功能。为探明喀斯特山地城市镶嵌山体斑块的时空变化,以典型喀斯特山地城市贵阳市中心城区为对象,运用2000—2020年5期高分辨率遥感影像,采用GIS空间分析、探索性空间数据模型、景观格局分析等方法,从规模、形态和空间分布方面,分析了快速城市化背景下山体斑块格局的时空变化特征。结果表明:(1)贵阳市中心城区山体斑块数量和面积分布广泛,但20年间山体斑块数量减少30座,面积减幅达25.2%,表现出先切割打碎后吞并侵占的特征,其中大型山体规模持续减小,其他各类型山体数量和面积呈“先增后减”的变化趋势。(2)山体斑块分维数接近1,整体形状较为规则,2000—2020年山体斑块形状指数增大近1.12倍,斑块形状总体呈现复杂化、破碎化的趋势; 但大型、中大型山体斑块形状更加规则化,而其他类型山体斑块形状日趋复杂破碎。(3)山体斑块具有极显著的空间聚集效应,最邻近指数介于0.766 9～0.841 4,全局性空间聚类标准化Z值小于-2.58,以小面积山体斑块的聚集为主,分布具有明显的空间异质性。20年间,空间聚集效应减弱,高密度区逐渐萎缩,低密度区不断扩散且呈集中连片趋势; 并且山体斑块的潜在生态连通性水平持续降低。     

A tale of urban forest patch governance in four eastern US cities

Urban forests are important components of societal interactions with nature. We focused on urban forest patches, a distinct and underexplored subset of the urban forest that spans land uses and ownerships, and requires silvicultural practices to address their unique biophysical characteristics and management regimes. Our goal was to elucidate multi-scalar urban forest patch governance arrangements as they translated to on-the-ground management in four urban areas (Chicago, New York City, Philadelphia, and Baltimore) within the eastern United States. A transdisciplinary knowledge co-production framework was used to guide identification of the prominent management challenge or dilemma motivating change to forest patch management in each location, and to describe the dynamic interplay of decision-making and governance processes across locations as they advanced toward desired forest conditions. A common management goal existed across all four locations: multi-age, structurally complex forests dominated by regionally native species. Ecological and social concerns affected by local context and city capacity served as starting points prompting management action and new collaborations. Disparate governance arrangements including top-down municipal resources, regional conservation facilitated by landowners, and grass-roots community-driven stewardship led to diverse support-building processes and innovative strategies that served as forces initiating and shaping new management actions. Science and iterative learning and adaptation influenced change in all locations, reinforcing new management arrangements and practices. Among the four study areas, the earliest management of urban forest patches started in the 1980 s, historically lacking embeddedness in urban forest management more broadly, and experiencing challenges with integration into existing governance infrastructure. Ultimately, new management and governance approaches to urban forest patches in all four study areas have evolved uniquely and organically, driven by place-based historical legacies and ongoing socio-ecological feedbacks. The generalization of findings for broader urban forest management guidelines, such as for trees and park, would lead to misguided outcomes.     

土地利用数据综合中图斑多边形决策推理

针对土地利用数据综合中图斑的化简处理,将智能体技术引入到图斑的综合处理过程中,建立了顾及多种条件的图斑重要性判断的决策机制,将可操作的几何、语义控制指标融入到推理中,实现了从图斑重要性判断到尺度变换算子选择的自动化过程,最后通过实际生产进行检验,结果显示该过程能够大幅度地提高生产效率,并能够很好地维护土地利用数据的面积平衡性以及全覆盖、无重叠、无缝隙的特征.该研究可为多比例尺国土资源数据库提供技术支持.     

C6, a new monoclonal antibody,reacts with the follicle-associated epithelium of calf ileal Peyer's patches

The follicle-associated epithelium (FAE) of Peyer''s patches (PPs) contains M cells that are important for reducing mucosal immune responses by transporting antigens into the underlying lymphoid tissue. We generated a monoclonal antibody (C6) that reacted with the FAE of calf ileal PPs, and analyzed the characteristics of C6 using immunohistochemistry and Western blotting. FAE of the ileal PP was stained with C6 during both late fetal developmental and postnatal stages. Neither the villous epithelial cell nor intestinal crypt basal cells were stained at any developmental stage. During the prenatal stages, FAE of the jejunal PP was C6-negative. However, a few C6-positive cells were distributed diffusely in some FAE of the jejunal PPs during the postnatal stages. The protein molecular weight of the antigen recognized by C6 was approximately 45 kDa. These data show that C6 is useful for identifying the FAE in ileal PPs and further suggest that differentiation of the FAE in these areas is independent of external antigens.