Identifying remains of extinct kangaroos in Late Pleistocene deposits using collagen fingerprinting

Our knowledge of past animal populations, including the geographical ranges of extinct species, has largely been derived from morphological analyses of skeletal fossil remains. However, a major barrier to the identification of the remains of extinct megafaunal species in archaeological and palaeontological sites is the highly fragmented nature of the material, which often precludes confident taxonomic identifications based on morphology. Biomolecular techniques are able to go beyond these limitations and are increasingly being used to make such identifications. Protein analysis offers a promising alternative to DNA techniques because they can be much cheaper, more amenable to high‐throughput processing and work on much older specimens. Here we demonstrate the potential of collagen fingerprinting in an Australian context by extracting collagen from 50‐ka kangaroo fossils from two caves in Tasmania, and identify several species including the extinct short‐faced kangaroo Simosthenurus occidentalis . Importantly, of the five fossil bones sampled that had hitherto been ascribed morphology‐based identifications below the family level, three had been incorrectly identified during an initial assessment of photographs taken in the field. Our results highlight the utility of using protein‐based methods for making genus‐level identification of marsupial bone, especially those that may form a basis for broader arguments such as that of late‐surviving megafaunal species.

     

贝类养殖风险控制体系建设的基本构想

随着贝类养殖技术的提高,贝类养殖种类与养殖方式日趋多元化,养殖规模逐步扩大,养殖产量不断增加,现已成为中国水产养殖的重要组成部分。基于对中国贝类养殖发展现状的分析,将贝类养殖风险归纳为自然、生态、经济社会与技术风险等四类,并对四大风险的来源进行了深入分析,提出了建立贝类养殖"一体两翼"风险控制体系的基本构想。最后,从政府扶持、团队建设、科技攻关、融资等方面提出了保障措施与建议。     

中国栉孔扇贝养殖和育种的回顾与展望

栉孔扇贝作为一种双壳贝类，其营养和经济价值较高，在中国海水养殖业中占有重要地位。自20世纪50年代开始，栉孔扇贝养殖产业先后经历了自然采苗、半人工采苗、人工育苗、提纯复壮和新品种培育等过程，逐渐成为中国北方主要的浅海浮筏养殖品种。本文综述了中国栉孔扇贝养殖产业的发展历程，简要总结其养殖和育种过程中存在的问题，并对其今后的发展进行展望。     

新型局地增长模培育法对两次飑线个例的对流尺度集合预报试验

利用局地增长模培育法对两次典型飑线过程进行了对流尺度集合预报试验,通过与传统增长模培育法对比,检验了局地增长模培育法的实际预报效果.通过概率匹配平均处理后,将降水预报结果与实况资料进行对比分析,并用分数技巧评分来代替传统公平技巧评分实现对降水结果的合理检验,得出结论:1)在飑线降水预报上,局地增长模培育法优于增长模培育...     

基于Local-BGM法的冷涡暴雨集合预报试验及评估检验北大核心

基于传统增长模繁殖法(Breeding Growing Mode,BGM)和局地增长模繁殖法(Local Breeding Growing Mode,Local-BGM)生成初始扰动成员,对一次冷涡暴雨过程进行集合预报试验,从多方面比较两种方案的预报效果,并且在邻域概率法(Neighborhood Probability,NP)中引入时间邻域,评估概率预报结果。结果表明,引入局地化思想的Local-BGM方案能够生成比传统BGM方案更合理的初始扰动,具有很明显的局地特征。对于扰动变量的预报,Local-BGM方案在均方根误差和离散度等方面均表现更好,同时能够提高各量级降水的预报技巧。邻域集合概率法能够综合各个集合成员预报的降水信息得到优于集合平均的概率预报,分数技巧评分更高。并且在考虑时间不确定性后,无论是控制预报、集合平均还是邻域集合概率法,分数技巧评分均有很大改善,并且降水阈值越大改善效果越明显,能够为极端强降水天气提供较为客观的概率预报信息。     

ESRfrag: A new suite of open access programs for the efficient handling of Electron Spin Resonance spectra of enamel fragments

Accurate decomposition of Electron Spin Resonance (ESR) spectrum is a crucial task to extract compound signal intensities of enamel fragments at different irradiation time, in particular for dose recovery accuracy. While it can be achieved manually, the task is laborious and repetitive. In this paper, we present a new freely available program “ESRfrag” that allows the alignment, merging, and computation of complex angular ESR spectra. This program is an open access web-based code, designed to specifically alleviate the daunting task of working with large amounts of ESR spectra for enamel fragment dating. ESRfrag provides an increased reliability and precision on the results compared to manual calculation by removing operators bias. The program can be freely access through the Geoarchaeology and Archaeometry Research Group website (https://www.garg.org.au/projects).