吉林哈尼湖钻孔5000年来的植被演替与气候变化

重建古气候、古环境已成为当今全球变化研究的热点。5000以来是人类有文字记录的历史时期，其气候与植被变化与人类活动十分密切，对这一时期的气候变化的研究，具有重要的理论意义。 植被的状况可以在相当大的程度上反映气候的状况。孢子和花粉由于其个体小、产量高和易于保存而成为植被演替和古气候、古环境研究的重要手段之一。 孢粉组合的变化可以很好地反映植被的演替，吉林地区地层沉积比较稳定，本文选取哈尼湖钻孔360-0cm（5112－0aBP）的沉积物进行孢粉分析，共采取样品85个，平均时间分辨率约为60年。样品中花粉含量非常丰富，种类以乔木为主，其百分含量多在80%以上，最高可达96%，根据花粉组成在钻孔上的变化，结合花粉沉积率进行样品的分析，自下而上可分为4个花粉组合带，进而得出5000年以来该区气候演化大致可分为4个阶段：阶段1（5112－3784aBP），阔叶类乔木占优势，湿生及水生草本比较丰富，气候温暖湿润;阶段2（ 3784 －1380aBP）针叶类乔木占优势，湿生及水生草本消失，气候变凉干;阶段3（ 1380 －994aBP），以松为主的针叶类仍占绝对优势，喜温湿的灌木草本含量持续下降，说明气候继续变冷变干;阶段 4（ 994－0aBP），植物种类比较丰富，湿生植物的沉积率明显增高，气候变的更加湿润。

吉林柳河哈尼湖早中全新世古气候变化与环境演变的高分辨率孢粉纪录

　　全新世是与人类关系最密切的地质时期，重建全新世气候变化的历史，对人类的生产生活有重要的意义。植被是自然界中对气候变化反映最灵敏的指示物，通过地层剖面中的花粉分析，可以揭示古代植物区系，恢复古植被，因此，孢粉分析被用作研究植被演化、环境变迁的重要手段。 　　本文选取吉林哈尼湖钻孔剖面837~304cm（13.1~4.5cal.kaB.P.）沉积物进行孢粉分析，共采集样品123个，平均时间分辨率为69年。建立了早中全新世以来东北地区的孢粉组合序列，恢复了这一时段的植被演替序列，在此基础上，重点研究讨论了早中全新世气候事件在东北地区植被演替中的响应，为全新世古环境和气候变化的演变提供孢粉学证据。 　　研究结果表明：哈尼地区早中全新世以来气候演化有以下特征：13.1~11.9cal.kaB.P.为疏林草原景观，从11.9cal.kaB.P.开始逐渐发展成山地寒温性针叶林，至9.3cal.kaB.P.演化成栎为主的落叶阔叶林，5.5cal.kaB.P后松增加，发展成针阔混交林。从植被的变化推测，本区的气候经历了四个阶段的变化：冷干——冷湿——暖湿——凉干，虽然存在着冷暖干湿的变化，但自然环境基本为湿润状态，较稳定地保持了森林景观，气候变化相对温和。本区在进入大暖期以来气候并不稳定，分别在6.8、6.1、5.5、4.7cal kaB.P有不同程度的冷湿和冷干事件。频谱分析表明，本区在13.1～4.5cal.kaB.P.存在1100、700、500及300年的气候变化的准周期。

Quantitative PCR assay of sewage-associated Bacteroides markers to assess sewage pollution in an urban lake in Dhaka, Bangladesh

This paper aimed to assess the magnitude of sewage pollution in an urban lake in Dhaka, Bangladesh by using Quantitative PCR (qPCR) of sewage-associated Bacteroides HF183 markers. PCR was also used for the quantitative detection of ruminant wastewater-associated CF128 markers along with the enumeration of traditional fecal indicator bacteria, namely, enterococci. The number of enterococci in lake water samples ranged from 1.1 x 104 to 1.9 x 105 CFU/100 ml of water. From the 20 water samples tested, 14 (70%) and 7 (35%) were PCR positive for the HF183 and CF128 markers, respectively. The numbers of the HF183 and CF128 markers in lake water samples were 3.9 x 104 to 6.3 × 107 and 9.3 x 103 to 6.3 x 105 genomic units (GU)/100 ml of water, respectively. The high numbers of enterococci and the HF183 markers indicate sewage pollution and potential health risks to those who use the lake water for non-potable purposes such as bathing and washing clothes. This is the first study that investigated the presence of microbial source tracking (MST) markers in Dhaka, Bangladesh where diarrhoeal diseases is one of the major causes of childhood mortality. The molecular assay as used in this study can provide valuable information on the extent of sewage pollution, thus facilitating the development of robust strategies to minimise potential health risks.

Statistical phylogeographic tests of competing 'Lake Carpentaria hypotheses' in the mouth-brooding freshwater fish, Glossamia aprion (Apogonidae)

Glacial cycles during the Pleistocene reduced sea levels and created new land connections in northern Australia, where many currently isolated rivers also became connected via an extensive paleo-lake system, 'Lake Carpentaria'. However, the most recent period during which populations of freshwater species were connected by gene flow across Lake Carpentaria is debated: various 'Lake Carpentaria hypotheses' have been proposed. Here, we used a statistical phylogeographic approach to assess the timing of past population connectivity across the Carpentaria region in the obligate freshwater fish, Glossamia aprion. Results for this species indicate that the most recent period of genetic exchange across the Carpentaria region coincided with the mid- to late Pleistocene, a result shown previously for other freshwater and diadromous species. Based on these findings and published studies for various freshwater, diadromous and marine species, we propose a set of 'Lake Carpentaria' hypotheses to explain past population connectivity in aquatic species: (1) strictly freshwater species had widespread gene flow in the mid- to late Pleistocene before the last glacial maximum; (2) marine species were subdivided into eastern and western populations by land during Pleistocene glacial phases; and (3) past connectivity in diadromous species reflects the relative strength of their marine affinity.

The Lake of the Cemetery

This is brief paper written in the "here and now" as the event happened and describes the early morning journey of the author by balsa wood raft to the breeding colony of greater flamingoes (Phoenicopterus ruber) on the island of Isabela in the Galapagos archipelago in 1976. Isabela comprises five volcanoes in a north south alignment. The Lake of the Cemetary is close to the site of a former penal colony which is now the only village on the island. The ethological observations at the bird colony are discussed.

Realizing 'four comforts' in the urban fringe : the case of White Horse Lake Eco-creative City Project, Hangzhou, China

This article examines a cultural and creative industries park project – the White Horse Lake Ecocreative City on land outside the urban centre of Hangzhou, China, which uses an imaginary rural lifestyle as its key attraction. By analysing government policies and development plans, and through interviews with initiators, managers and creative practitioners, the article first assesses the geographical position, that is, the impact of locality with regard to both hard and soft infrastructure of the project; it then examines the synergies and tensions embedded in the strategic goals, that is, to build the right city for ‘four comforts’ (siyi, 四宜) – for residence, for business, for travel and for culture. The article concludes that Chinese-style cultural conversion remains locked in a top-down ideological framework, one that rural residents and the new ‘creative class’ are expected to respect.

Genuine community engagement in remote dryland regions : natural resource management in Lake Eyre Basin

Remote dryland regions are characterised by sparse populations and socially marginalised voices which pose particular challenges to natural resource management. This paper considers the issue of how to achieve community engagement in regions with these characteristics. In doing so, the paper contributes to an expanding international research agenda focusing on the distinct characteristics of arid and semi-arid regions under the heading of 'dryland syndrome'. The paper draws on government liaison officer and local community perspectives of successful engagement in the case-study region of Lake Eyre Basin, Australia. The results demonstrate that widely recognised characteristics of successful engagement are required but insufficient for genuine engagement in remote dryland regions. In addition to building trust through community ownership, being inclusive, effective communication, and adequate resources, genuine community engagement in drylands also requires respecting the extreme conditions and extraordinary variability of these areas. Residents of dryland regions seek genuine engagement yet engage opportunistically when seasons are conducive and when tangible outcomes are visible. © 2011 The Authors. Geographical Research © 2011 Institute of Australian Geographers.

Tools for successful NRM in the Lake Eyre Basin : achieving effective engagement

This chapter was developed as part of the ‘People, communities and economies of the Lake Eyre Basin’ project. It has been written for communities, government agencies and interface organisations involved in natural resource management (NRM) in the Lake Eyre Basin (LEB). Its purpose is to identify the key factors for successful community engagement processes relevant to the LEB and present tools and principles for successful engagement processes. The term ‘interface organisation’ is used here to refer to the diverse range of local and regional organisations (such as Catchment Committees or NRM Regional Bodies) that serve as linkages, or translators, between local communities and broader Australian and State Governments. The importance of fostering and harnessing effective processes of community engagement has been identified as crucial to building a prosperous future for rural and remote regions in Australia. The chapter presents an overview of the literature on successful community engagement processes for NRM, as well as an overview of the current NRM arrangements in the LEB. The main part of the chapter presents findings of the series of interviews conducted with the government liaison officers representing both state and federal organisations who are responsible for coordinating and facilitating regional NRM in the LEB, and with the members of communities of the LEB.

Cryptanalysis of the LAKE hash family

We analyse the security of the cryptographic hash function LAKE-256 proposed at FSE 2008 by Aumasson, Meier and Phan. By exploiting non-injectivity of some of the building primitives of LAKE, we show three different collision and near-collision attacks on the compression function. The first attack uses differences in the chaining values and the block counter and finds collisions with complexity 233. The second attack utilizes differences in the chaining values and salt and yields collisions with complexity 242. The final attack uses differences only in the chaining values to yield near-collisions with complexity 299. All our attacks are independent of the number of rounds in the compression function. We illustrate the first two attacks by showing examples of collisions and near-collisions.

Managing creativity on the margins : a comparative study of Beijing’s Songzhuang Art District and Hangzhou’s White Horse Lake Creative Eco-City

In the past decade the ‘creative cluster’ has become a driver of urban renewal in China. Many cluster developments attract human capital and investment to post-industrial spaces. This paper looks at two developments which are more post-agricultural than post-industrial: the first is Songzhuang, a large scale contemporary art community situated on the eastern fringe of Beijing, the second is Hangzhou’s White Horse Lake Creative Eco-City, a ‘mixed variety’ cluster model which integrates elements of art, fashion, design and animation. The common factor in both cases is how they came into existence. In both districts urban creative workers moved into a rural environment. Drawing on interviews with planners, officials, and residents we investigate the challenges of sustaining such fringe clusters.