The role of biological research in supporting policy needs     

Leonard P 《Marine environmental research》2002,54(3-5):209-213

Within the UK, the Department for Environment, Food and Rural Affairs (DEFRA) is one of several government departments which undertakes research in support of its policy aims. For example, DEFRA has responsibility for licensing the deposit of materials in the sea in order to protect the environment, public health and prevent interference with other uses of the sea. This includes assessment of pollutant responses in marine organisms. The objectives include assessment of the sub-lethal effect that pollutants have at the cellular, organ and individual level, for example in normal genetic, behavioural and reproductive activity and extrapolation of the potential impact of pollutants to populations. This work helps DEFRA to establish whether individually or in combination, pollutants have an adverse effect on the environment. This paper gives some examples of the research undertaken and demonstrates how biological research can provide cost effective solutions to analytical problems and an opportunity to predict the way in which proposed disposal operations may have an impact on the marine environment. The way such research may influence policy is also discussed.  相似文献   

The effect of standing biomass on flow velocity and turbulence in Spartina alterniflora canopies     

Lynn A. Leonard  Alexander L. Croft 《Estuarine, Coastal and Shelf Science》2006,69(3-4):325

Plant-flow interactions on the surface of tidal wetlands result in flow characteristics that are profoundly different from non-vegetated flows. Reductions in mean flow velocity and turbulence, especially the vertical components, limit vertical mixing and may impact a wide range of processes including geochemical exchanges at the sediment water interface, larval recruitment and dispersion, and sediment deposition and retention. The goal of this paper is to quantify horizontal and vertical components of velocity, turbulence intensity and total turbulent kinetic energy in Spartina alterniflora canopies in southeastern North Carolina and to relate flow characteristics to particulate transport on the marsh surface. Another aim of this paper is to assess the extent to which the distribution of standing biomass affects mean flow and turbulence by comparing S. alterniflora data to other canopy types and through a series of canopy manipulations which altered canopy height and stem densities.The results of this study indicate that flow velocity, turbulence intensity, and total turbulent kinetic energy (TKE) are significantly reduced within the vegetated canopy and that this reduction is inversely related to the amount of biomass present in the water column. Within the canopy, approximately 50% of the initial mean velocity and TKE is reduced within 5 m of the canopy edge. Within the canopy, mean velocity and TKE_horiz usually exceeded vertical velocity or TKE_vert and the vertical components of flow were attenuated more strongly than the horizontal. These results suggest that within the vegetation, turbulence contributes more to lateral advection than to vertical mixing. As a result, total suspended solid concentrations were shown to decrease logarithmically with distance from the canopy edge and to decrease at a faster rate in more densely vegetated regions of the canopy (i.e. lower TKE_vert) as compared to areas of sparser vegetation (i.e. higher TKE_vert).  相似文献   

Meteorite organics in planetary environments: hydrothermal release, surface activity, and microbial utilization     

Mautner MN  Leonard RL  Deamer DW 《Planetary and Space Science》1995,43(1-2):139-147

Up to 50% of the organics in the Murchison meteorite, possibly including some of the polymer, is released in high temperature and pressure aqueous environments, to 350 degrees C and 250 bar, that simulate submarine volcanic, hydrothermal or impact-induced conditions. Meteorite organics of prebiotic significance, such as nonanoic acid, glycine, and pyrene survive the hydrothermal conditions. The released material is surface active with surface pressures up to 19.8 x 10(-3) N m-1, and exhibits an extended surface tension isotherm which suggests a mixture of amphiphilic components. One component, nonanoic acid, is shown to form vesicles. The materials extracted under mild conditions, at 120 degrees C, are nutrients for the humic acid bacterium Pseudomonas maltophilia and efficient nutrients for the oligotroph Flavobacterium oryzihabitans, demonstrating the capability of microorganisms to metabolize extraterrestrial organics.  相似文献   

A Space-Time GIS Approach to Exploring Large Individual-based Spatiotemporal Datasets   总被引：3，自引：0，他引：3  

Shih-Lung Shaw  Hongbo Yu  Leonard S Bombom 《Transactions in GIS》2008,12(4):425-441

The increasing number of large individual-based spatiotemporal datasets in various research fields has challenged the GIS community to develop analysis tools that can efficiently help researchers explore the datasets in order to uncover useful information. Rooted in Hägerstrand's time geography, this study presents a generalized space-time path (GSTP) approach to facilitating visualization and exploration of spatiotemporal changes among individuals in a large dataset. The fundamental idea of this approach is to derive a small number of representative space-time paths (i.e. GSTPs) from the raw dataset by identifying spatial cluster centers of observed individuals at different time periods and connecting them according to their temporal sequence. A space-time GIS environment is developed to implement the GSTP concept. Different methods of handling temporal data aggregation and the creation of GSTPs are discussed in this article. Using a large individual-based migration history dataset, this study successfully develops an operational space-time GIS prototype in ESRI's ArcScene and ArcMap to provide a proof-of-concept study of this approach. This space-time GIS system demonstrates that the proposed GSTP approach can provide a useful exploratory analysis and geovisualization environment to help researchers effectively search for hidden patterns and trends in such datasets.  相似文献   

Natural hazards in Australia: floods     

Fiona Johnson  Christopher J. White  Albert van Dijk  Marie Ekstrom  Jason P. Evans  Dörte Jakob  Anthony S. Kiem  Michael Leonard  Alexandra Rouillard  Seth Westra 《Climatic change》2016,139(1):21-35

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Objective forecasting of frost using locally‐observed meteorological parameters     

Leonard M. Druyan  Nurit Chai 《大气与海洋》2013,51(4):396-402

Abstract

An objective scheme for forecasting frost is derived using scatter diagrams of meteorological parameters observed at 20 h local time at a station in the western Jezreel Valley of Zsrael. Verifîcation based on independent data was highly consistent with probabilities of frost versus no‐frost predicted by the suggested procedure.  相似文献   

Collaborative geomatics and the Mushkegowuk Cree First Nations: Fostering adaptive capacity for community-based sub-arctic natural resource management     

Daniel D.P. McCarthy  Graham S. Whitelaw  Scott Anderson  Donald Cowan  Fred McGarry  Anthony Robins  Holly L. Gardner  Christine D. Barbeau  Nadia A. Charania  Zachariah General  Jeff Liedtke  Celine Sutherland  Paulo Alencar  Leonard J.S. Tsuji 《Geoforum》2012,43(2):305-314

The remote First Nation (FN) communities of the Mushkegowuk Territory on the west coast of James Bay, Ontario, Canada are currently facing increased development pressures and the imposition of a government land use planning process. The land use planning process is mandated in the Far North Act (received Royal Assent on September 23, 2010). There is a need for capacity enhancement for community-based natural resource planning and management in the Territory. A number of frameworks are emerging for addressing change brought on by resource development and building resilience to such change at the community level. Among these include the concept of adaptive capacity. In collaboration with FN community leaders, we explored the use of “collaborative geomatics” tools to foster adaptive capacity. Our action research suggests that collaborative geomatics technologies should enhance the Mushkegowuk First Nations’ adaptive capacity to address environmental and policy change by allowing them to collect and manage data collaboratively (e.g., traditional environmental knowledge, western science) to create opportunities for innovative community development, including natural resource development and management.  相似文献   

Rates of microbial elemental sulfur oxidation and O and S isotopic fractionation under varied nutrient and temperature regimes     

Laura A. Smith  M. Jim Hendry  Leonard I. Wassenaar  John Lawrence 《Applied Geochemistry》2012

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An innovative tailored seasonal rainfall forecasting production in Zimbabwe     

Desmond Manatsa  Leonard Unganai  Christopher Gadzirai  Swadhin K. Behera 《Natural Hazards》2012,64(2):1187-1207

Farmers?? adaptation to climate change over southern Africa may become an elusive concept if adequate attention is not rendered to the most important adaptive tool, the regional seasonal forecasting system. Uptake of the convectional seasonal rainfall forecasts issued through the southern African regional climate outlook forum process in Zimbabwe is very low, most probably due to an inherent poor forecast skill and inadequate lead time. Zimbabwe??s recurrent droughts are never in forecast, and the bias towards near normal conditions is almost perpetual. Consequently, the forecasts are poorly valued by the farmers as benefits accrued from these forecasts are minimal. The dissemination process is also very complicated, resulting in the late and distorted reception. The probabilistic nature of the forecast renders it difficult to interpret by the farmers, hence the need to review the whole system. An innovative approach to a regional seasonal forecasting system developed through a participatory process so as to offer a practically possible remedial option is described in this paper. The main added advantage over the convectional forecast is that the new forecast system carries with it, predominantly binary forecast information desperately needed by local farmers??whether a drought will occur in a given season. Hence, the tailored forecast is easier for farmers to understand and act on compared to the conventional method of using tercile probabilities. It does not only provide a better forecasting skill, but gives additional indications of the intra-seasonal distribution of the rainfall including onsets, cessations, wet spell and dry spell locations for specific terciles. The lead time is more than 3?months, which is adequate for the farmers to prepare their land well before the onset of the rains. Its simplicity renders it relatively easy to use, with model inputs only requiring the states of El Nino Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) climate modes. The developed forecast system could be one way to enhance management of risks and opportunities in rain-fed agriculture among small-holder farmers not only in Zimbabwe but also throughout the SADC region where the impact of ENSO and/or IOD on a desired station rainfall is significant.  相似文献   

Decoupled stochastic mapping [for mobile robot & AUVnavigation]     

Leonard  J.J. Feder  H.J.S. 《Oceanic Engineering, IEEE Journal of》2001,26(4):561-571

This paper describes decoupled stochastic mapping (DSM), a new computationally efficient approach to large-scale concurrent mapping and localization (CML). DSM reduces the computational burden of conventional stochastic mapping by dividing the environment into multiple overlapping submap regions, each with its own stochastic map. Two new approximation techniques are utilized for transferring vehicle state information from one submap to another, yielding a constant-time algorithm whose memory requirements scale linearly with the number of submaps. The approach is demonstrated via simulations and experiments. Simulation results are presented for the case of an autonomous underwater vehicle navigating in an unknown environment with 110 and 1200 features using simulated observations of point features by a forward look sonar. Empirical tests are used to examine the consistency of the error bounds calculated by the different methods. Experimental results are also presented for an environment with 93 features using sonar data obtained in a 3 by 9 by 1 m testing tank  相似文献