研究生在基础与临床相结合科研项目中培养方法的几点思考

随着我国科研创新的开展与推进,学生进入实际科研项目已逐渐成为研究生培养的重要方式。基础与,临床相结合的科研项目立论均来自于临床问题,把在患者身上无法实现的方法通过基础实验的手段加以实施和验证,从而达到发现和揭示病因与发病机制的目的,结果甚或对临床产生指导意义。首都医科大学病理与病理生理学系研究生培养点结合这类研究项目的推进,在规范的方法和流程中引导和培养研究生从临床现象中设问、从海量数据中分析和论证的能力,并通过这些训练,使研究生为进一步深入研究奠定基础,共同为转化医学研究做出贡献。     

Mapping Cod: Fisheries Science,Fish Harvesters’ Ecological Knowledge and Cod Migrations in the Northern Gulf of St. Lawrence

Some recent scholarship has focused on integrating local and/or traditional knowledge with conventional scientific information in fisheries management to improve the factual foundation of and strengthen support for management decisions. This article compares a sequence of historical and contemporary scientific texts and maps about the migrations and stock structure of cod in the Northern Gulf of St. Lawrence with texts and maps generated by the authors through the collection, aggregation and interpretation of commercial fish harvesters’ ecological knowledge. We find that the relationship between fisheries science and harvesters’ ecological knowledge is dynamic and has changed over time, and that both are ‘situated’ socially and ecologically. Overall, each paints an incomplete picture of cod movements and stock structure but the knowledge of harvesters provides a valuable complement to scientific information, particularly at the local scale, and has the potential to contribute to the identification of local cod stocks that are new to science and management. We end by considering how this case study informs the larger discussion about the challenges and potential benefits of the so-called integration project to bring together science and the ecological knowledge of fish harvesters.

An Assessment of a Small Urban Stream Restoration Project in Northern California

Stream restoration projects have become increasingly common, and the need for systematic post‐project evaluation, particularly for small‐scale projects, is evident. This study describes how a 70‐m restored reach of a small urban stream, Baxter Creek (in Poinsett Park, El Cerrito, California), was quickly and inexpensively evaluated using habitat, biological, and resident‐attitude assessments. The restoration involved opening a previously culverted channel, planting riparian vegetation, and adding in‐stream step‐pool sequences and sinuosity. Replicated benthic macroinvertebrate samples from the restored site and an upstream unrestored site were compared using several metrics, including taxa richness and a biotic index. Both biological and habitat quality improved in the restored compared with the unrestored section. However, when compared with a creek restored 12 years before, habitat condition was of lower quality in the recently restored creek. A survey of the neighborhood residents indicated that, overall, they were pleased with the restored creek site. The approach used in this demonstration project may be applicable to other small‐scale evaluations of urban stream restorations.     

Biodiversity on the brink: Evaluating a transdisciplinary research collaboration

Global biodiversity is facing an extinction crisis. Australia has one of the highest terrestrial species extinction rates in the world. Scientists, policy advisors and governments have recommended that the issue be addressed at a landscape-scale, while noting that there are significant knowledge gaps that are hampering implementation of such an approach. From 2011–2015, the Australian Government funded a transdisciplinary research program, the Landscapes and Policy Hub, to meet this need. Transdisciplinary research is widely acknowledged as essential to address the complexity of contemporary environmental problems. Given that such research programs are in their infancy, it is important to evaluate their efficacy and provide an empirical basis for improving their design. This paper presents an evaluation of the strategies fostering transdisciplinarity adopted by the Landscapes and Policy Hub. A heavy emphasis on communication, with skilled knowledge brokering, regular face-to-face meetings using participatory activities and shared field engagements enhanced transdisciplinary interaction between researchers and research users. However, establishing a fully integrated interdisciplinary research program remained a challenge. Efforts to enable shared conceptual frameworks to emerge through adaptive application of theory in practice could have been balanced with increased effort at the outset for researchers and research users to collaboratively formulate shared research questions, leading to the establishment of teams that could address these questions through cross-mobilisation of interdisciplinary expertise.     

Governance of indigenous policy in the neo-liberal age: indigenous disadvantage and the intersecting of paternalism and neo-liberalism as a racial project

Thinking about the governance of Indigenous poverty as an economic, social and racial project, the paper offers a way of understanding the dynamics of Indigenous policy formation in Australia in the neo-liberal age as what Howard Winant first coined a racial formation. In providing this analysis, this paper sits alongside a small, but growing body of work that reveals the racialized effects of governing through poverty in the neo-liberal age.     

Decomposition of macrophyte litter in a subtropical constructed wetland in south Florida (USA)

The South Florida Water Management District has constructed large treatment wetlands (stormwater treatment areas (STAs)) to reduce total phosphorus concentrations in agricultural runoff before this water enters the Everglades. An important component of nutrient removal and storage in these systems is incorporation of nutrients into aquatic macrophytes and burial of this biomass in the sediments. However, decomposition of plant biomass before burial returns nutrients to the water column and may reduce STA treatment efficiency. As part of research on biogeochemical control of STA performance, we conducted a summer (July–September) and a long-term (12-month) experiment (February–February) that measured decomposition rates and release of chemical constituents from dominant aquatic macrophytes in a constructed wetland located in south Florida. The rank order of mean decomposition rates was Najas/Ceratophyllum (0.0568 d⁻¹) > Pistia (0.0508 d⁻¹) > Eichhornia (0.0191 d⁻¹) > submerged Typha (0.0059 d⁻¹) > aerial Typha (0.0008 d⁻¹). Summer decomposition rates were generally higher than rates from the long-term experiment, which suggested a temperature effect. Decomposition rates were negatively correlated with litter C:N and C:P molar ratios and cellulose and lignin content and positively correlated with N and P content. There was no significant difference in decomposition rates among sampling stations despite the fact that there was a decreasing gradient in water column inorganic phosphorus and nitrogen concentrations at these sites. Relatively little of the initial P mass remained in the litter of all species, except Typha, by the end of both experiments. First-order decomposition models derived using nonlinear regression generally had explanatory power, i.e. accounted for variance, comparable to more complex decreasing-coefficient models. Decomposition rates for the species examined in this study were within the range of published values when comparisons were made either by species or by plant group.     

小水电代燃料工程对森林生态服务功能的影响

根据国家林业局发布的《森林生态系统服务功能评估规范》(LY/T 1721—2008),从涵养水源、保育土壤、固碳释氧和积累营养物质功能4个方面进行评价,研究小水电代燃料工程的实施对贵州省麻江县项目区森林生态服务功能的物质量及其价值的影响.结果表明: 小水电代燃料工程对森林生态系统服务功能物质量的增加有显著作用.马尾松和柏木人工林在项目区内涵养水源功能的物质量达20662.04 m³·hm^-2·a^-1,比项目区外增加20.5%,保育土壤量为119.1 t·hm^-2·a^-1,比项目区外增加29.7%,固碳释氧量为220.49 t·hm^-2·a^-1,比项目区外增加40.2%,林木营养积累量达3.49 t·hm^-2·a^-1,比项目区外增加48.5%.小水电代燃料工程对项目区森林生态系统服务功能价值增加额度表现为:固碳释氧功能(7.14 万元·hm^-2·a^-1)>涵养水源功能(6.01万元·hm^-2·a^-1)>林木营养积累功能(1.38万元·hm^-2·a^-1)>保育土壤功能(0.81万元·hm^-2·a^-1).小水电代燃料工程对提高森林生态服务功能价值和实现林区的可持续发展具有重要作用.     

单细胞自由生物基因组全序列的测定和比较基因组研究

近几年来五种单细胞生物的基因组计划得以完成。本文介绍了从五种生物的全基因组序列获得的一些成果,包括全基因组鸟枪法测序、基因组分析和新比较基因组等三个方面,并对生物基因组计划的研究方法作一些探讨。     

Contrasting effects of repeated summer drought on soil carbon efflux in hydric and mesic heathland soils

Current predictions of climate change include altered rainfall patterns throughout Europe, continental USA and areas such as the Amazon. The effect of this on soil carbon efflux remains unclear although several modelling studies have highlighted the potential importance of drought for carbon storage. To test the importance of drought, and more importantly repeated drought year-on-year, we used automated retractable curtains to exclude rain and produce repeated summer drought in three heathlands at varying moisture conditions. This included a hydric system limited by water-excess (in the UK) and two mesic systems with seasonal water limitation in Denmark (DK) and the Netherlands (NL). The experimental rainfall reductions were set to reflect single year droughts observed in the last decade with exclusion of rain for 2–3 months of the year resulting in a 20–26% reduction in annual rainfall and 23–38% reduction in mean soil moisture during the drought period. Unexpectedly, sustained reduction in soil moisture over winter (between drought periods) was also observed at all three sites, along with a reduction in the maximum water-holding capacity attained. Three hypotheses are discussed which may have contributed to this lack of recovery in soil moisture: hydrophobicity of soil organic matter, increased water use by plants and increased cracking of the soil. The responses of soil respiration to this change in soil moisture varied among the sites: decreased rates were observed at the water-limited NL and DK sites whilst they increased at the UK site. Reduced sensitivity of soil respiration to soil temperature was observed at soil moisture contents above 55% at the UK site and below 20% and 13% at the NL and DK sites, respectively. Soil respiration rates recovered to predrought levels in the NL and DK sites during the winter re-wetting period that indicates any change in soil C storage due to changes in soil C efflux may be short lived in these mesic systems. In contrast, in the hydric UK site after 2 years of drought treatment, the persistent reduction in soil moisture throughout the year resulted in a year-round increase in soil respiration flux, a response that accelerated over time to 40% above control levels. These findings suggest that carbon-rich soils with high organic matter content may act as a significant source of CO₂ to the atmosphere following repeated summer drought. Nonrecovery of soil moisture and a persistent increase in soil respiration may be the primary mechanism underlying the reported substantial losses of soil carbon from UK organic soils over the last 20 years. These findings indicate that the water status of an ecosystem will be a critical factor to consider in determining the impact of drought on the soil carbon fluxes and storage.