Ophiostoma novo-ulmi sp. nov., causative agent of current Dutch elm disease pandemics

The aggressive subgroup of the Dutch elm disease pathogen Ophiostoma ulmi (Buism.) Nannf. syn. Ceratocystis ulmi (Buism.) Moreau is named as a new species, O. novo-ulmi, and is thereby separated from the old non-aggressive subgroup, which is retained as O. ulmi. O. novo-ulmi differs from O. ulmi in colony morphology, growth rate, optimum temperature for growth, perithecial neck length, pathogenicity to elm, bark colonising ability, cerato-ulmin protein production, synnemetal and protoperithecial production, mating type frequency, protein and isozyme polymorphisms, mitochondrial DNA and nuclear DNA polymorphisms, and mitochondrial DNA size. In addition, a strong unidirectional fertility barrier operates between the two species, while their hybrids show remarkable variation, poor fitness, and many are infertile. These aspects are summarised. New information on perithecial dimensions is presented. O. ulmi is redefined and a neotype designated. The status of the Eurasian and North American races of O. novo-ulmi is currently under investigation.Abbreviations EAN Eurasian race - NAN North American race     

北美水貂和欧亚水獭在东北地区的分布与生态位重叠

作为入侵物种,北美水貂(Neovison vison)在欧洲引起了一系列生态问题,侵占了欧亚水獭(Lutra lutra)的生态空间,其入侵性对当地生物多样性和生态系统构成了严重威胁。水貂引入我国东北地区已有70多年的历史,然而国内对其野外种群却鲜有研究。掌握水貂种群的入侵范围、入侵影响因素以及与本地具有相似生态位的欧亚水獭之间的竞争关系,对水貂的入侵管理和东北地区的生物多样性保护具有重要意义。本研究利用实地调查和文献资料获取的分布信息,通过集合模型识别水貂和水獭的潜在分布区,评估水貂对水獭在地理空间上的入侵风险,并通过主成分分析(principal component analysis,PCA)评估其生态位重叠和影响因素。结果表明:(1)我国东北地区水貂的潜在分布区面积为61,944.57 km²,水獭的潜在分布区面积为83,590.94 km²,两者重叠区域面积为50,544.21 km²,占水獭潜在分布区面积的60.47%;(2)从各省分布情况来看,黑龙江省水獭受水貂入侵的风险最高,潜在分布区重叠的比例达到78.9...     

基于DNA变异在亚欧混合人群中预测男性型脱发

男性型脱发(male pattern baldness,MPB)是一种雄激素依赖性的遗传性脱发疾病,对个人形象、心理产生较大的消极影响.近期欧美人群中进行的大样本全基因组关联分析(genome wide association studies,GWAS)已报道大量与MPB相关的遗传易感性单核苷酸多态性(single nucleotide polymorphisms,SNPs)位点,但这些位点在东亚人群中的遗传效应尚不清楚.本研究基于我国684个亚欧混合人群(Eurasian)样本,对在英国生物样本库(UK Biobank) 205 327个欧洲男性GWAS分析发现的624个与MPB相关的SNPs进行人群异质性分析,基于多基因风险打分(polygenic risk scores,PRS)建立预测模型,并对预测因子数量与模型预测性能的关系进行了研究.通过质控的467个SNPs中6.9%与MPB显著相关(P0.05).结合年龄、体质指数(body mass index,BMI)和25个SNPs建立的线性回归和逻辑回归模型,效果较好(R~2=28.9%,AUC=0.82).年龄对模型效果影响较大(R~2=22.9%,AUC=0.77),结合BMI及68个SNPs时AUC达到最大(约0.89).本研究表明MPB在欧洲和东亚人群中存在较强的遗传异质性,选取SNPs子集能达到与全集相近的预测准确性,预测模型有助于东亚人群MPB遗传机制的理解及疾病的早期诊断和预防.     

Vocalizations and courtship displays of the Bittern Botaurus stellaris

Capsule We report on the courtship behaviour of the Eurasian Bittern from direct observation in rice fields.     

Ecological role of vertebrate scavengers in urban ecosystems in the UK

Recent research has demonstrated how scavenging, the act of consuming dead animals, plays a key role in ecosystem structure, functioning, and stability. A growing number of studies suggest that vertebrate scavengers also provide key ecosystem services, the benefits humans gain from the natural world, particularly in the removal of carcasses from the environment. An increasing proportion of the human population is now residing in cities and towns, many of which, despite being highly altered environments, contain significant wildlife populations, and so animal carcasses. Indeed, non‐predation fatalities may be higher within urban than natural environments. Despite this, the fate of carcasses in urban environments and the role vertebrate scavengers play in their removal have not been determined. In this study, we quantify the role of vertebrate scavengers in urban environments in three towns in the UK. Using experimentally deployed rat carcasses and rapid fire motion‐triggered cameras, we determined which species were scavenging and how removal of carcass biomass was partitioned between them. Of the 63 experimental carcasses deployed, vertebrate scavenger activity was detected at 67%. There was a significantly greater depletion in carcass biomass in the presence (mean loss of 194 g) than absence (mean loss of 14 g) of scavengers. Scavenger activity was restricted to three species, Carrion crows Corvus corone, Eurasian magpies Pica pica, and European red foxes Vulpes vulpes. From behavioral analysis, we estimated that a maximum of 73% of the carcass biomass was removed by vertebrate scavengers. Despite having low species richness, the urban scavenger community in our urban study system removed a similar proportion of carcasses to those reported in more pristine environments. Vertebrate scavengers are providing a key urban ecosystem service in terms of carcass removal. This service is, however, often overlooked, and the species that provide it are among some of the most disliked and persecuted.     

内蒙古赛罕乌拉国家级自然保护区猞猁食物构成初步分析

猞猁(Lynxlynx)是内蒙古赛罕乌拉国家级自然保护区内的顶级捕食者,在维持该地区生态平衡和调节猎物数量上具有重要地位。分析猞猁粪便样品残留物不仅能明确其猎物构成,了解与同域分布其他捕食者的关系,还能为制定物种保护措施和栖息地管理策略提供科学参考。本研究在2006至2008年间利用样线法在该区域收集到35份猞猁粪便样品。通过相对出现频率法对粪样进行食性分析,发现猞猁的主要食物组成以蒙古兔(Lepus tolai,30.85%)和植物(28.72%)较多;年度(χ~2=18.696,P <0.001)和季节性(χ~2=74.695,P <0.001)食物构成均存在显著差异。结果表明,蒙古兔在猞猁的食物组成中占最重要地位;猞猁的食物构成与季节有关,寒冷季节捕食大型猎物,而温暖季节捕食的小型猎物更常见。     

Path tortuosity of Eurasian badgers (<Emphasis Type="Italic">Meles meles</Emphasis>) in a heterogeneous Mediterranean landscape

Movement is the process by which individual organisms are displaced over time to eat, reproduce and defend resources. Fractal analysis is a technique used to study animal movement that measures spatial complexity of path tortuosity; here, we apply it to characterize the movement patterns of the Eurasian badger (Meles meles) in a Mediterranean landscape. We calculated path tortuosity overall and seasonally, and for individuals of different sexes and social groups. The influence of variables related to badgers’ resources (food, shelter, water), human infra-structures and weather conditions were analysed with respect to the tortuosity of each badger’s path. A total of 55 search paths from six badgers were considered for this study. Although badgers generally displayed convoluted movement, there were two exceptions: (a) males overall and (b) all badgers in summer; for both, movements had a lower fractal value, i.e. were less tortuous. The convoluted movement pattern generally observed is probably adapted to the clumped distribution of food in the study area. Nevertheless, our results suggest that the use of dens and latrines were the principal determinants of tortuosity of badgers’ paths while foraging.     

Sorption of Co, Cu, Ni and Zn from industrial effluents by the submerged aquatic macrophyte Myriophyllum spicatum L.

The submerged aquatic plant Myriophyllum spicatum L. (Eurasian water milfoil) has been suggested as an efficient plant species for the treatment of metal-contaminated industrial wastewater. The process of metal removal by plants involves a combination of rapid sorption on the surface and slow accumulation and translocation in the biomass. This study focussed on the sorption/desorption characteristics of the surface of M. spicatum for Co, Cu, Ni and Zn. Batch sorption tests with mixed metal solutions covering a range of 0, 1, 5, 10, 50 and 100 mg l⁻¹ of each metal, were performed. For Co, Ni and Zn, the sorption process was well described by the Langmuir model, whereas sorption of Cu was better described by the Freundlich model. The biomass showed the highest affinity for Cu and Zn. Langmuir sorption maxima of Co, Ni and Zn were 2.3, 3.0 and 6.8 mg g⁻¹ DM, respectively. At the highest initial concentration of 100 mg l⁻¹, a maximum of 29 mg g⁻¹ DM of Cu was sorbed onto the surface of the biomass. Desorption by 0.1 M HCl did not fully recover the metals sorbed onto the surface and there was evidence of leaching from within the biomass. Recovery of heavy metals and regeneration of the biomass by washing with 0.1 M HCl was therefore not suggested as a viable strategy.