506 research outputs found

    Effective risk governance for environmental policy making: a knowledge management perspective

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    Effective risk management within environmental policy making requires knowledge on natural, economic and social systems to be integrated; knowledge characterised by complexity, uncertainty and ambiguity. We describe a case study in a (UK) central government department exploring how risk governance supports and hinders this challenging integration of knowledge. Forty-five semi-structured interviews were completed over a two year period. We found that lateral knowledge transfer between teams working on different policy areas was widely viewed as a key source of knowledge. However, the process of lateral knowledge transfer was predominantly informal and unsupported by risk governance structures. We argue this made decision quality vulnerable to a loss of knowledge through staff turnover, and time and resource pressures. Our conclusion is that the predominant form of risk governance framework, with its focus on centralised decision-making and vertical knowledge transfer is insufficient to support risk-based, environmental policy making. We discuss how risk governance can better support environmental policy makers through systematic knowledge management practices

    A new approach to the chronology of caves 268/272/275 in the Dunhuang Mogao Grottoes: combining radiocarbon dates and archaeological information within a Bayesian statistical framework

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    The construction chronology of three of the earliest Dunhuang Mogao Grottoes (Caves 268, 272, and 275) has been the subject of ongoing debate for over half a century. This chronology is a crucial topic in terms of further understanding of the establishment of the Dunhuang Mogao Grottoes, early Buddhism in the Gansu corridor, and its relationship with Buddhism developed in the Central Plains. Building upon archaeological, art historical and radiocarbon (14C) dating studies, we integrate new 14C data with these previously published findings utilizing Bayesian statistical modeling to improve the chronological resolution of this issue. Thus, we determine that all three of these caves were constructed around AD 410ā€“440, suggesting coeval rather than sequential construction

    The RESET tephra database and associated analytical tools

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    An open-access database has been set up to support the research project study- ing the ā€˜Response of Humans to Abrupt Environmental Transitionsā€™ (RESET). The main methodology underlying this project was to use tephra layers to tie together and synchronise the chronologies of stratigraphic records at archaeological and envi- ronmental sites. The database has information on occurrences, and chemical compo- sitions, of glass shards from tephra and cryptotephra deposits found across Europe. The data includes both information from the RESET project itself and from the published literature. With over 12,000 major element analyses and over 3000 trace element analyses on glass shards, relevant to 80 late Quaternary eruptions, the RESET project has generated an important archive of data. When added to the published information, the database described here has a total of more than 22,000 major element analyses and nearly 4000 trace element analyses on glass from over 240 eruptions. In addition to the database and its associated data, new methods of data analysis for assessing correlations have been developed as part of the project. In particular an approach using multi-dimensional kernel density estimates to evaluate the likelihood of tephra compositions matching is described here and tested on data generated as part of the RESET project.</p

    Zimbabwe culture before Mapungubwe: new evidence from Mapela Hill, South-Western Zimbabwe

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    Across the globe, the emergence of complex societies excites intense academic debate in archaeology and allied disciplines. Not surprisingly, in southern Africa the traditional assumption that the evolution of socio-political complexity began with ideological transformations from K2 to Mapungubwe between CE1200 and 1220 is clouded in controversy. It is believed that the K2āˆ’Mapungubwe transitions crystallised class distinction and sacred leadership, thought to be the key elements of the Zimbabwe culture on Mapungubwe Hill long before they emerged anywhere else. From Mapungubwe (CE1220-1290), the Zimbabwe culture was expressed at Great Zimbabwe (CE1300-1450) and eventually Khami (CE1450-1820). However, new fieldwork at Mapela Hill, when coupled with a Bayesian chronology, offers tremendous fresh insights which refute this orthodoxy. Firstly, Mapela possesses enormous prestige stone-walled terraces whose initial construction date from the 11 th century CE, almost two hundred years earlier than Mapungubwe. Secondly, the basal levels of the Mapela terraces and hilltop contain Ć©lite solid dhaka (adobe) floors associated with K2 pottery and glass beads. Thirdly, with a hilltop and flat area occupation since the 11 th century CE, Mapela exhibits evidence of class distinction and sacred leadership earlier than K2 and Mapungubwe, the supposed propagators of the Zimbabwe culture. Fourthly, Mapungubwe material culture only appeared later in the Mapela sequence and therefore post-dates the earliest appearance of stone walling and dhaka floors at the site. Since stone walls, dhaka floors and class distinction are the essence of the Zimbabwe culture, their earlier appearance at Mapela suggests that Mapungubwe can no longer be regarded as the sole cradle of the Zimbabwe culture. This demands not just fresh ways of accounting for the rise of socio-political complexity in southern Africa, but also significant adjustments to existing models

    New pathways of sociopolitical complexity in southern Africa

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    Much is known about the economy and spatial organization of Zimbabwe culture entities of Mapungubwe, Great Zimbabwe and Khami but less in terms of their origins and relationship with each other. Based on little tangible evidence, it is believed and widely accepted that the societies based at Mapungubwe (AD 1220ā€“1290), Great Zimbabwe (AD 1300ā€“1450) and Khami (AD 1450ā€“1820) rose, developed and eclipsed in tandem. A recent reexamination of the relationship between these settlements and related ones using local ceramics, imported artefacts, stone architecture and Bayesian modelling suggests this may not have been the case. The synthesis proffered revelations which temper the widely accepted assumption that sociopolitical complexity in southern Africa began in the Shashi-Limpopo Valley before anywhere else in the region. Firstly, there are numerous Zhizo and Leopardā€™s Kopje sites that predate Mapungubwe but contain prestige goods and stone structures dating from the late first millennium AD. Secondly, material culture studies and modelled radiocarbon dates indicate that Great Zimbabwe evolved out of Gumanye while Khami, like Mapungubwe, may have developed out of the Leopardā€™s Kopje. In fact, Great Zimbabwe was already a place of importance when Mapungubwe collapsed. Thirdly, Khami and Great Zimbabwe overlapped for over a century, before the latter buckled. Therefore, the evolution of sociopolitical complexity in southern Africa may have followed trajectories that are different from what the current understanding implies.National Research Foundation of South Africa (Bluesky Research Grant: 85892) and the Programme for Enhancement of Research Capacity (PERC) of University of Cape Town Research Office.http://link.springer.com/journal/10437hb201

    In vivo quantification of peroxisome tethering to chloroplasts in tobacco epidermal cells using optical tweezers

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    Open access articlePeroxisomes are highly motile organelles that display a range of motions within a short time frame. In static snapshots they can be juxtaposed to chloroplasts which has led to the hypothesis that they are physically interacting. Here, using optical tweezers we have tested the dynamic physical interaction in vivo. Using near-infrared optical tweezers, combined with TIRF microscopy, we were able to trap peroxisomes and approximate the forces involved in chloroplast association in vivo, and observed weaker tethering to additional unknown structures within the cell. We show that chloroplasts and peroxisomes are physically tethered through peroxules, a poorly described structure in plant cells. We suggest peroxules have a novel role in maintaining peroxisome-organelle interactions in the dynamic environment. This could be important for fatty acid mobilisation and photorespiration through interaction with oil bodies and chloroplasts, highlighting a fundamentally important role for organelle interactions for essential biochemistry and physiological processes.Biotechnology and Biological Sciences Research Council (BBSRC)Science and Technology Facilities Council (STFC)Wellcome Trust - Institutional Strategic Support AwardLeverhulme Trus

    The production and composition of Chinese lead-barium glass through experimental laboratory replication

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    Lead-barium glass appeared during the late Warring States period in China (457 - 221 BCE) and was considered as a Chinese invention due to the unique presence of high barium. There is no indication as to how it was made. A set of twenty-four different combinations of possible raw materials were melted to test and systematically evaluate the possible recipes for lead-barium glass. Specifically, the function and source of sodium in lead-barium glass were explored. The results show that sodium source is crucial for lead-barium glass forming in this particular system. This paper explores an alternative formulation since sodium flux is not reported in historical Chinese sources, in which the Na2O is provided by including soda-lime glass in the mixture. This particular formulation provides a potential explanation for the source of the sodium in lead-barium glas

    Large-Scale Turnover of Functional Transcription Factor Binding Sites in Drosophila

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    The gain and loss of functional transcription factor binding sites has been proposed as a major source of evolutionary change in cis-regulatory DNA and gene expression. We have developed an evolutionary model to study binding-site turnover that uses multiple sequence alignments to assess the evolutionary constraint on individual binding sites, and to map gain and loss events along a phylogenetic tree. We apply this model to study the evolutionary dynamics of binding sites of the Drosophila melanogaster transcription factor Zeste, using genome-wide in vivo (ChIPā€“chip) binding data to identify functional Zeste binding sites, and the genome sequences of D. melanogaster, D. simulans, D. erecta, and D. yakuba to study their evolution. We estimate that more than 5% of functional Zeste binding sites in D. melanogaster were gained along the D. melanogaster lineage or lost along one of the other lineages. We find that Zeste-bound regions have a reduced rate of binding-site loss and an increased rate of binding-site gain relative to flanking sequences. Finally, we show that binding-site gains and losses are asymmetrically distributed with respect to D. melanogaster, consistent with lineage-specific acquisition and loss of Zeste-responsive regulatory elements

    Relationships between physical qualities and key performance indicators during match-play in senior international rugby union players

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    The use of physical tests to profile physical capabilities, and provide training direction to athletes is common practice. Likewise, in professional team sports, notational analysis codes the key contributions of each player during competition. Limited studies have however investigated relationships between physical capabilities and key performance indicators (KPIs) of rugby union match-play. Elite professional players, categorised as forwards (n = 15) or backs (n = 14), from an international rugby union squad (n = 29) undertook assessments of isometric mid-thigh pull (IMTP), bilateral and unilateral countermovement jumps (CMJ) and drop jumps (DJ; from 40 and 20 cm, respectively), and assessment of acceleration (10 m), a 5 m weighted sled drive, and a Yo-Yo intermittent recovery test level 1 (Yo-Yo IRTL1). Game statistics of the same players from 92 matches (~23 matches per player) during the 2014ā€“15 season were analysed for effort and performance-based metrics. For forwards, Yo-Yo IRTL1 correlated significantly with; number of tackles made (r = 0.717), first three players at a ruck in both attack (r = 0.568) and defence (r = 0.581), number of effective rucks (r = 0.630), total possessions (r = 0.522), passes made (r = 0.651), percentage of carries over the gainline (r = 0.610), effective ruck success (r = 0.600), tackle success (r = 0.540), and the number of turnovers made (r = 0.518). Drop jump performance in forwards was associated with; the number of clean breaks (r = 0.558), dominant collisions (r = 0.589), and offloads (r = 0.594). For backs, the sled-drive test correlated with; number of carries (r = -0.751), first three players at an attacking ruck (r = -0.613), effective attacking rucks (r = -0.584), number of dominant collisions (r = -0.792) and offloads (r = -0.814). Likewise, for backs, IMTP peak force was related to; the number of possessions (r = 0.793), passes made (r = 0.792), effective attacking ruck percentage (r = 0.628), and the number of offloads (r = 0.621) whilst relative peak force correlated with; the percentage of carries over the gainline (r = 0.533), percent tackle success (r = 0.603) and effective attacking ruck percentage (r = 0.584). Regression analyses highlighted that only a small number of variables (i.e., carries, tackles, attacking and defensive first three at ruck) returned practically achievable changes
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