贫困村认定及扶持政策的减贫效应检验——来自安徽省W县全域280个行政村的经验证据

贫困村认定是中国扶贫重点开发县政策在县域空间尺度内部的更精准化瞄准。安徽省六安市W县（国家贫困县）280个行政村2016—2017年的扶贫数据表明，贫困村认定政策所裹挟的倾斜式财政资金投入对贫困村出列和贫困发生率逐年降低发挥了强有力的保障作用；贫困村认定政策具有显著的减贫效应；产业帮扶财政资金投入的减贫效应强于农村基础设施建设投资。随着中国扶贫战略由"消除绝对贫困"到"减少相对贫困"演进，贫困村认定政策的制度设计仍可延续，未来应做好"认定—投入—验收"流程，以减少瞄准失偏和促进资源优化配置。     

赤眼蜂在不同生境植物上分布的初步研究

本文对湖北省9种赤眼蜂在不同生境植物上的分布作了调查分析。结果表明,湖北省9种赤眼蜂可寄生在21科25属25种植物的虫卵上,根据25种植物的生态特点,可划为农田型、沼泽型、林间型和广布型四类。属于农田型有玉米螟赤眼蜂(Trichogramma ostriniae)和广赤眼蜂(T.evanescens),林间型有舟蛾赤眼蜂(T.closterae)和风蝶赤眼蜂(T.seticini),沼泽型有稻螟赤眼蜂(T.japonicum),广布型有拟澳洲赤眼蜂(T.Confusum)、松毛虫赤眼上(T.dendrolimi)、毒蛾赤眼峰(T.ivelae)和粘虫赤眼蜂(T.1eucaniae)。     

Au Elements and Their Evolution in Some AIIopolyploid Genomes of Aegilops

To study the sequences of short interspersed nuclear elements （SINEs） evolution in some allopolyploid genomes of Aegilops, 108 Au element fragments （a novel kind of plant SINE） were amplified and sequenced in 10 species of Aegilops, which were clustered into three different groups （A, B and C） based on their related geuome types. The sequences of these Au element fragments were heterogouous in di-, tetra-, and hexa-ploids, and the deudrograms of Au element obtained from phylogenetic analysis were very complex in each group and could be clustered into 15, 15 and 22 families, respectively. In this study, three rules about Au elements evolution have been drawn from the results： i. Most families were composed of Au element members with different host species in three groups; ii. Family 1-6 in Group A, Family 1-6 in Group B, Family 1-4 and Family 6-13 in Group C contained only one, apparently highly degenerate Au dement member （a single representative elemeut）; iii. Elements generally fell into clades that were species-specific with respect to their host species. The potential mechanisms of Au element evolution in Aegilops were discussed.     

徐州市北郊土壤重金属污染演化特征研究

对1991年和2003年徐州市北郊工业区土壤中重金属的含量作了对比分析，探讨了该区土壤重金属污染的演化特征。结果表明，12年来，该区土壤中重金属含量的水平分布，除了Cu污染有所减轻外，Cd、Pb、Zn、Cr污染都有不同程度加重，顺序是Cd＞Pb＞Zn＞Cr，而且Cd普遍超标；垂直分布上逐渐递减的规律已受到扰动，个别元素有淋溶沉积现象。     

哀牢山自然保护区南华分区黑颈长尾雉春季栖息地利用

2004年2~4月,对云南哀牢山自然保护区南华分区黑颈长尾雉Syrmaticus humiae的春季栖息地利用进行了研究。结果表明:①黑颈长尾雉春季栖息地有常绿阔叶林、稀树灌丛林和华山松Pinus armandii;幼林等3种,前两者为其主要的栖息生境类型。②黑颈长尾雉栖息地的主要特征是高海拔,向阳坡,坡度较大,距水源较近,距道路较远;乔木层平均胸径和高度较小,盖度和密度较低,以壳斗科Fagaceae和山茶科Theaceae植物为主;灌木层较高但密度较低,以山茶科和杨柳科Salicaceae植物占优势;草本层密度较大,以堇菜科Violaceae,蔷薇科Rosaceae和菊科Compositae种类为主;枯落物层盖度较低。③草本层和灌木层提供大量食物和优越的隐蔽条件,其作用大于乔木层。草本层密度和灌木层盖度是决定黑颈长尾雉春季栖息地利用的主要因素。表3参20     

甘肃、青海和宁夏地区牛病毒性腹泻病毒Erns基因的变异分析

分析2013—2019年中国西北部分省区不同基因亚型牛病毒性腹泻病毒（BVDV）抗原基因E^rns的分子特征,了解其遗传演化规律。从甘肃、青海、宁夏规模化牛场送检的疑似牛病毒性腹泻发病牛150份EDTA抗凝血提取总RNA,利用RT-PCR扩增病毒基因组E^rns-E1区,克隆测序后比对,构建系统进化树进行遗传演化关系分析。利用牛肾细胞MDBK对检出的不同基因亚型BVDV进行分离,并鉴定其生物型。RT-PCR扩增结果表明,BVDV总体阳性率为37.33%,其中甘肃省、青海省、宁夏回族自治区BVDV阳性率分别为37.68%、35.71%、40.00%。获得56份E^rns-E1 DNA,克隆测序获得33条不同的E^rns序列,长度均为681 bp,分析表明流行株分属10个BVDV基因亚型：BVDV-1a （2株）、BVDV-1b （5株）、BVDV-1c （1株）、BVDV-1d （3株）、BVDV-1m （11株）、BVDV-1o （1株）、BVDV-1p （4株）、BVDV-1q （4株）、BVDV-1v （1株）、BVDV-2a （1株）。分离获得BVDV-1a亚型、BVDV-1b亚型、BVDV-1v亚型、BVDV-2a亚型分离株各1株,BVDV-1 d亚型分离株2株,均为非致细胞病变型。各亚型株间E^rns基因核苷酸相似性以BVDV-1a～1d经典亚型株（79.8%～85.9%）或1m～1q及1v新亚型株（81.0%～87.3%）较高,以BVDV-1 m和BVDV-1p流行株亚型间相似性最高（87.3%）。各亚型株E^rns基因编码蛋白的RNA酶活性位点以及双链RNA作用基序（₁₃₉KKGK₁₄₂）保守,但E^rns第26位糖基化位点（26 NRSL）在1m～1q、1v亚型株移位（24 NVSR）。首次以E^rns核苷酸序列构建系统进化树,结果显示1m～1q及1v等亚型BVDV株在进化上关系较为密切。本研究首次选用E^rns靶标基因对甘肃、青海、宁夏部分省区牛源BVDV株进行同源性及系统进化分析,发现10个基因亚型流行株,以1m亚型株最为普遍,1m～1q及1v等亚型株亲缘关系密切。     

Bird habitat preferences drive hemoparasite infection in the Neotropical region

The role that the environment plays in vector-borne parasite infection is one of the central factors for understanding disease dynamics. We assessed how Neotropical bird foraging strata and habitat preferences determine infection by parasites of the genera Haemoproteus, Plasmodium, Leucocytozoon, and Trypanosoma and filarioids, and tested for phylogenetic signal in these host–parasite associations. We performed extensive searches of the scientific literature and created a database of hemoparasite surveys. We collected data on host body mass, foraging strata, habitat preference, and migratory status, and tested if host ecological traits predict each hemoparasite occurrence and prevalence using a phylogenetic Bayesian framework. Species of Plasmodium tend to infect birds from tropical forests while birds from altitudinal environments are likely to be infected by species of Leucocytozoon. The probability of a bird being infected by filarioid or Trypanosoma is higher in lowland forests. Bird species that occur in anthropic environments and dry habitats of tropical latitudes are more susceptible to infection by species of Haemoproteus. Host foraging strata is also influential and bird species that forage in the mid-high and canopy strata are more prone to infection by species of Haemoproteus and filarioids. We also identified phylogenetic signal for host–parasite associations with the probability of infection of Neotropical birds by any hemoparasite being more similar among more closely related species. We provided a useful framework to identify environments that correlate with hemoparasite infection, which is also helpful for detecting areas with potential suitability for hemoparasite infection due to land conversion and climate change.     

Evaporation ponds as a drainwater disposal management option

Constructed evaporation ponds are being utilized for disposalof saline subsurface drainage waters in San Joaquin Valley,California. These terminal evaporation ponds are located inhydrologically closed basins and/or regions with no surfacedrainage out of the valley. The saline drainwaters disposedinto the ponds are sodium-sulfate or sodium-sulfate-chloridetype waters and upon desiccation produces mirabilite andhalite. The drainwaters contain excessive levels of traceelements from geochemical origins. The trace element of mostconcern, is selenium because it bioaccumulates in the aquaticfood chain and causes death and deformity of waterbirdsattracted to the pond environment. At the present, the onlyeconomic drainwater disposal option in the southern. portionof the valley is evaporation ponds. The operation of theseponds is heavily regulated by waste discharge requirements toreduce and mitigate wildlife impacts. A case study onevaporation ponds and bird usage from a drainage districtillustrates the extensive monitoring and mitigation required.The prognosis is evaporation basins will be needed for theforeseeable future unless breakthroughs occur in economic andeffective drainwater treatment and drainwater reuseoptions.     

梯级水电站水量平衡的研究

针对三个梯级水电站出现的水量计算不平衡的现象，通过对这三个水电站的日常水情调度数据的分析和对库区河段的明渠非恒定流计算，探讨了水量计算不平衡的原因，并给出了这些水电站的水位流量关系特性，对其他流域梯级水电站有一定参考作用。     

基于纹理差异度引导的DRLSE病虫害图像精准分割方法

为精准分割纹理背景下的病虫害目标,提出一种基于混合高斯模型的纹理差异度表示方法和基于纹理差异度引导的DRLSE农作物病虫害精准分割方法。采用基于混合高斯模型的纹理差异度表示方法得到纹理差异度图像,利用Otsu自动阈值分割和形态学后处理得到农作物病虫害DRLSE演化的初始区域,将基于改进纹理差异度的边缘停止函数应用到DRLSE演化中。实验结果表明该方法可以获得精准的害虫和病变区域轮廓。