稻曲病菌交配型基因MAT1-2-1和MAT1-2-8的特性分析

 有性生殖在真菌的生活史和进化过程中具有重要作用,而交配型基因是控制有性生殖的关键因子。前期研究发现稻曲病菌(Villosiclava virens)MAT1-2型菌株中包含MAT1-2-1和MAT1-2-8两个交配型基因,但是它们如何调控稻曲病菌有性生殖依然不清楚。本文研究了它们在不同侵染和生长发育时期的表达模式和编码的蛋白结构特性。研究表明MAT1-2-1在侵染不同阶段一直下调表达;而MAT1-2-8在侵染早期(5 dpi)上调表达,在侵染后期下调表达。与营养菌丝阶段比较,MAT1-2-1和MAT1-2-8在有性发育过程菌核形成、菌核萌发、子座原基形成和子座成熟4个阶段的表达量都是下降的,在菌核形成阶段表达量最低。生物信息学分析显示MAT1-2-1和MAT1-2-8具有磷酸化位点,为非分泌蛋白,无明显的跨膜结构域。蛋白同源比对分析表明MAT1-2-1与香柱菌(Epichloë typhina)的MAT1-2-1同源性最高,而MAT1-2-8与绿僵菌(Metarhizium)的MBR_08192蛋白同源性最高。进一步研究发现MAT1-2-1和MAT1-2-8能够互作,并分别主要定位在细胞核和细胞基质中。通过质谱技术鉴定到MAT1-2-1的一些候选互作蛋白,如假定Ran交换因子Prp20/Pim1(KDB12229.1)、假定rRNA处理蛋白Ebp2(KDB12923.1)及组蛋白H1(KDB12711.1)等。因此,以上结果为研究稻曲病菌交配型基因MAT1-2-1和MAT1-2-8调控有性生殖的生物学功能奠定了基础。     

Multi-scale use of lands providing anthropogenic resources by American Crows in an urbanizing landscape

The conversion of forests and farmlands to human settlements has negative impacts on many native species, but also provides resources that some species are able to exploit. American Crows (Corvus brachyrhynchos), one such exploiter, create concern due to their impact as nest predators, disease hosts, and cultural harbingers of evil. We used various measures of crow abundance and resource use to determine crows’ response to features of anthropogenic landscapes in the Puget Sound region of the United States. We examined land cover and land use composition at three spatial scales: study sites (up to 208 ha), crow home ranges within sites (18.1 ha), and local land cover (400 m²). At the study site and within-site scales crow abundance was strongly correlated with land cover providing anthropogenic resources. In particular, crows were associated with the amount of ‘maintained forest’ cover, and were more likely to use grass and shrub cover than forest or bare soil cover. Although crows did not show a generalized response to an edge variable, they exhibited greater use of patchy habitat created by human settlements than of native forests. Radio-tagged territorial adults used resources within their home ranges relatively evenly, suggesting resource selection had occurred at a larger spatial scale. The land conversion pattern of new suburban and exurban settlements creates the mix of impervious surfaces and maintained vegetation that crows use, and in our study area crow populations are expected to continue to increase. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Vertical distribution of sand-dust aerosols and the relationships with atmospheric environment

The vertical distribution of aerosols in the troposphere is important for determining their effects on climate.The vertical distribution of aerosols under different atmospheric conditions in the free troposphere was directly observed using a surface micro-pulse LIDAR(MPL) and a TP/WVP-3000 microwave radiometer at the Semi-Arid Climate & Environment Observatory of Lanzhou University(SACOL,35.95°N,104.10°E) in the western Loess Plateau,China,in the spring of 2008.The results showed two possible transportation paths of a sandstorm from May 1 to May 4 in 2008.In one path,sand-dust aerosols were transported toward the east from the Taklimakan Desert to the Badain Jaran Desert and the Tengger Desert by a westerly wind and then toward the southeast to Jingtai and Lanzhou.A weak aerosol index(AI) indicated another possible transport path toward the east from the Taklimakan Desert to the Qaidam Basin and through the Tibetan Plateau eastward to SACOL.The aerosol profile of sandstorm processes over the SACOL area displayed three patterns:a single peak distribution under stable atmospheric conditions,indicating urban aerosol distribution;an exponential decrease under unstable atmospheric conditions in the presence of a sandstorm;and a slight change in the mixed layer during the first and last stages of the sandstorm,indicative of thorough mixing during lifting and deposition stages.Analyses of the aerosol layer height(ALH) showed that there are two types of ALH diurnal variation.The ALH during the first sandstorm stage was complex and disordered,and affected by atmospheric circulation.While the ALH had obvious diurnal variation in the other stage,the ALH and aerosol extinction coefficient(AEC) had a single peak,and was higher in the afternoon and lower in the morning.In the second case the ALH was in agreement with the atmospheric boundary layer height(BLH) variation.As a result of the development of the atmospheric boundary layer(ABL) during day and maintenance at night,ALH during sandstorm-free days showed obvious diurnal variations.Multiple vertical distribution patterns of sand-dust aerosols will result in different climate effects;therefore,the vertical distribution patterns can be used to parameterize climate and aerosol models.     

阿拉善荒漠特有珍稀濒危植物绵刺克隆生长构型研究

绵刺是阿拉善荒漠特有珍稀濒危植物 ,其具有独特的克隆生长构型 :由枝条下垂形成长间隔物的典型的游击型克隆生长构型和由根茎处形成的典型的密集型克隆生长构型。本文以环境塑造与克隆生长构型的可塑性关系研究绵刺的克隆生长构型 ,揭示其对环境表现出生态对策的高度适应性和可塑性     

木瓜秀粉蚧在海南的适生性及空间分布型研究

木瓜秀粉蚧是热带和亚热带地区重要的危险性害虫,本研究利用最大熵模型(Max Ent)和地理信息系统(GIS)软件,依据该虫的分布数据和20个环境因子预测其在海南的适生性,并对木瓜秀粉蚧在木薯地中的空间分布型进行了分析。结果表明:木瓜秀粉蚧在海南的高度适生区主要有陵水、乐东、东方、昌江、海口西部等地,模型的AUC值为0.982,表明该模型预测结果可靠;影响其分布的主要环境因子有年均降水量、最冷季度平均温度、年温度变化范围和最湿润季度降水量等,因子贡献率分别为23.7%、16.5%、14.2%和12.1%;用聚集度指标法确定木瓜秀粉蚧在木薯上一定密度下的空间分布为聚集分布,并采用m*-m回归法和Taylor幂法则对其进行了验证;成虫在木薯植株上的分布,表现为上、中层的虫口密度显著高于下层。研究结果对提高木瓜秀粉蚧的监测和防控水平具有指导意义。     

扬州市古运河生态环境林观光休闲型绿化模式营建研究

结合对扬州市古运河的整治，营建生态环境林观光休闲型滨河绿地风光带。在其实施的第1期工程中，就观光休闲型绿化模式的定位功能、建模原理、模式结构、绿化设计原则、主要地段景点的绿化配置与造景造意，以及模式绿化的初期效果等进行初步研究探讨。要求通过增加乔木数量，配置观赏人工植物群落，搭配仿古园林建筑，保护古文化遗迹，形成滨河绿地森林公园，最终达到既发挥观光旅游、休闲娱乐游憩功能，又发挥净化空气、改善城市生活环境的生态功能的目的。     

图们江流域湿地空间格局变化与保护

图们江流域的自然环境较为复杂,湿地类型丰富,分布广泛。源头及上游以森林沼泽和灌丛沼泽为主,中游多为草本沼泽,下游到图们江口,湿地分布广泛,主要类型为天然和人工湖泊,草本沼泽。由于人为活动,湿地的空间分布格局发生较大的变化。为保护湿地的环境功能,必须加强湿地环境监测,合理调整湿地空间结构,保证湿地资源的可持续利用。     

Improving preventive locust management: insights from a multi‐agent model

BACKGROUND

Preventive management of locust plagues works in some cases but still fails frequently. The role of funding institution awareness was suggested as a potential facilitating factor for cyclic locust plagues. We designed a multi‐agent system to represent the events of locust plague development and a management system with three levels: funding institution, national control unit and field teams. A sensitivity analysis identified the limits and improvements of the management system.

RESULTS

The model generated cyclic locust plagues through a decrease in funding institution awareness. The funding institution could improve its impact by increasing its support by just a few percent. The control unit should avoid hiring too many field teams when plagues bring in money, in order to ensure that surveys can be maintained in times of recession. The more information the teams can acquire about the natural system, the more efficient they will be.

CONCLUSION

We argue that anti‐locust management should be considered as a complex adaptive system. This not only would allow managers to prove to funders the random aspect of their needs, but would also enable funders and decision‐makers to understand and integrate their own decisions into the locust dynamics that still regularly affect human populations. © 2017 Society of Chemical Industry     

陕西省集雨节灌工程发展模式与对策

分析了陕西省开展集雨节灌的必要性和可行性,探讨陕西省不同地区集雨节灌发展模式及发展前景,提出了今后工程建设中要注意做好规划,按照先易后难原则分步实施,加大集蓄雨水的配套节水灌溉技术推广步伐,加强工程管理,加大科学研究力度等对策。     

知识融合教学模式在“数据结构”教学中的应用

＂数据结构＂课程具有理论性和实践性强,以及与计算机专业其他课程关联密切的特点,可以将知识融合教学模式应用于该课程的教学中,从教学内容、实践环节和考核评价指标等方面进行改革。结果表明,采用知识融合教学模式能够显著提高教学质量,促进学生专业应用能力和综合素质的提高。