A cadaver study comparing two approaches for performing maxillary nerve block in dogs

Objective To compare the success by inexperienced anaesthetists of using a modified infraorbital approach to the maxillary nerve with the traditional percutaneous approach. Study design Prospective, randomized, blinded controlled study. Animals Heads from 37 euthanized Beagle and Beagle cross dogs. Methods Four anaesthetists were recruited to perform two different approaches to block the maxillary nerve of the cadavers. The infraorbital (I) approach advanced an intravenous catheter along the infraorbital canal. Earlier measurements from scans of similar heads were used to assess suitable catheter size. The percutaneous (P) approach introduced a needle percutaneously just below the ventral border of the zygomatic arch. The side of the head where the technique was to be performed was randomized. A total volume of 0.5 mL methylene blue was injected in each approach. After completion of injections, head dissections were performed by an investigator unaware of the approach used and staining of the maxillary and pterygopalatine nerves was evaluated. Chi squared analysis examined the relationship between the methods (p < 0.05). Complications related to the techniques, such as intravascular/intraneural injection and location of the dye, were evaluated macroscopically. Results Maxillary nerve staining >6 mm was found in 64.9% (I) versus 21.6% (P) attempts; staining <6 mm was found in 27% (I) versus 21.6% (P); and no nerve staining 8.1% (I) versus 56.8% (M). Pterygopalatine nerve staining was found in 70% (I) versus 21% (P). The infraorbital approach demonstrated significantly higher maxillary and pterygopalatine nerve staining compared to the percutaneous approach (p = 0.001 for both nerves). No evidence of intravascular/intraneural injections was found. Conclusion and clinical relevance The infraorbital approach was more successful than the percutaneous approach when performed by inexperienced anaesthetists. No macroscopic complications were observed.     

Communicative Action to Level the Playing Field in Forest Plantations in Indonesia

The government of Indonesia allocated state land to private companies to establish forest plantations. However, ownership of this land was contested by some Sumatran communities. The plantation company, endorsed by the government, quickly developed a partnership to resolve the conflict, but this was unclear and inequitable. Action research was carried out to facilitate communication among stakeholders. This communicative action changed some perceptions and shared values began to emerge. A forum was established, which contributed to equitability producing a better partnership. This research is a model for empowering local communities in climate change, bioenergy, and food security negotiations.     

The Evolution of Watershed Councils and the Oregon Plan

Summary

Revisiting the history of Oregon politics, especially environmental policy, shows that populist tradition and innovative government are tied together. Political innovation through massive reform led to the Oregon System, a governmental approach that allows a good deal of direct, or participatory, democracy. The degree of direct democracy in Oregon, or at least the threat of voters bypassing the legislature, led to a series of environmental laws passed in the 1970s. Along with similar federal laws, these set a regulatory baseline from which to build a watershed protection strategy. Key to this Watershed Health Program is the role of community-based watershed councils, which provide a good example of local, inclusive, participatory democracy. Utilizing watershed councils as the key component of a state watershed restoration strategy within the context of a regulatory baseline is an example of a hybrid centralized/decentralized approach to environmental policy. This hybrid approach is a political innovation that serves as an incremental response to competing environmental and anti-government populism. This approach will be severely tested by the 1997 Oregon Plan for Salmon and Healthy Watersheds, a state conservation plan designed to head off a listing of salmonid species under the Endangered Species Act. If this approach is successful, community-based ecosystem management groups and states that wish to copy Oregon's example will have new ideas to foster maintenance and restoration of ecosystems through state-administered conservation plans.     

马铃薯皮中黄酮类物质测定及含量

以马铃薯皮为试验材料,研究了黄酮类化合物提取方法,获得了提取马铃薯皮中黄酮类化合物的最佳条件,测量了马铃薯皮中体现抗氧化性的黄酮类化合物的含量。试验中,对马铃薯皮中黄酮类化合物进行了提取、分离,以1,1-二苯基-2-三硝基苯肼(1,1-Diphenyl-2-picrylhydrazyl radical 2,2-Diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl,DPPH)的清除率作为马铃薯皮中提取的黄酮类化合物含量及抗氧化活性的评价指标。通过单因素试验,确定提取溶剂、温度、时间、料液比等对提取结果的影响程度。并在单因素试验的基础上设计4因素3水平的正交试验,从而确定马铃薯皮中黄酮类化合物的最佳提取条件。结果表明,马铃薯皮中黄酮类抗氧化物的提取最佳条件为50℃的温度下用80%丙酮溶液按照料液比1:10的比例提取,提取时间为3 h。在此条件下测得DPPH的清除率为84.62%。在最佳提取条件下提取马铃薯皮中黄酮类化合物,并测得每克烘干后的马铃薯皮中含有约10.95 mg的黄酮类物质,与其它类果实果皮中具有相似的抗氧化活性的黄酮类物质的含量相比明显较高。     

间作植物根系对Pb斑块胁迫适应机制

为研究间作体系植物根系受Pb胁迫的形态学适应机制,利用根箱试验设计Pb斑块胁迫下玉米、小花南芥单作和玉米与小花南芥间作处理。结果表明:在Pb斑块(0、1000 mg·kg~(-1))处理根箱条件下,间作小花南芥根生物量的相对关系指数显著增加,小花南芥根趋向有Pb斑块生长,根系表面积显著增加,间作模式极显著影响小花南芥根系形态;间作玉米根生物量的相对关系指数显著降低,玉米根趋向无Pb斑块生长,Pb处理极显著影响玉米根系形态。径级在1.5 mmd3≤2.5 mm根表面积显著影响间作小花南芥与玉米对Pb的响应。研究表明,根间相互作用激发小花南芥根系趋向Pb斑块,玉米根系趋向无Pb斑块,揭示了超富集植物与作物间作体系促进两种植物根系趋向性适应的重要原因。     

基于大食物观的多元化食物供给体系构建研究

构建多元化食物供给体系能够稳定和扩大食物供给,满足人们多样化食物需求的要求,促进农业食物系统转型。本文运用大食物观的思路,通过对相关政策、文献和数据的系统梳理,分析我国在构建多元化食物供给体系上的主要做法,探讨其不足,提出未来构建多元化食物供给体系的对策建议。研究表明,我国在提高国内粮食产量、保障重要农产品的供给、参与农产品国际贸易、树立大农业观和大食物观方面取得了很大的成绩,但同时也存在农产品供给与消费需求不匹配、食物消费多元化不足、国内农产品生产区域布局不平衡、国外农产品进口过度集中、农产品加工多样化程度不高等制约多元化食物供给的障碍。为了更好地构建多元化食物供给体系,应以大食物观来统筹粮食和重要农产品生产,丰富优化食物生产和消费结构,拓宽扩大食物来源,合理布局农产品生产区域,拓宽农业食物系统全产业链,统筹利用好国内和国际两个市场两种资源。     

探讨林地生态保护的作用及途径

生态保护工程是国家的绿化工程建设的重点,也是森林保护的重点内容,随着当前的 国家绿化建设发展加快,国家的绿化工程不断推动建设,林地的保护工作受到的重视程度加深, 部门的负责人员需要通过一定的措施,正视林地的生态建设过程中面临的问题,通过不断的探 索,寻求有效的途径,为生态保护工作的顺利进行提供重要的途径内容。     

Participatory research approaches to integrating scientific and farmer knowledge of soil to meet multiple objectives in the English East Midlands

Soil management influences food production, economic performance of farm businesses, and a range of public benefits such as water quality, flood control and aquatic and terrestrial biodiversity. The aim of this paper is to explore the role of participatory research in combining scientific and farmer knowledge of soils to meet these multiple objectives. We use five separate research studies involving communication, consultation and co‐production, carried out in the English East Midlands between 2014 and 2018. We compare the participatory processes for knowledge exchange and their material outcomes and assess them retrospectively against specified criteria for successful application of participatory research. We conclude that, depending on context and scalar fit, multiple approaches to participatory research can be complementary, strengthen engagement and build trust within a farming community, resulting in a greater shared understanding of how to address the soil management objectives of farmers and wider society.     

雄安新区上游农业种植结构及需水时空演变

本文利用作物模型模拟小麦、玉米灌溉需水量,结合蒸发皿法估算蔬菜、果树等其他作物需水量,回溯雄安新区上游1986-2015年农业种植结构及农业需水的时空演变趋势,摸清不同作物的需水量比例及时间变化,并推算了消除降水年际波动的1970-2015年农作物灌溉需水量,探讨单纯人类活动下的农业需水量变化趋势。结果表明,1986-2015年,研究区作物播种总面积总体呈上升趋势,耕地面积多年平均84.9万hm²,有效灌溉面积平均71.3万hm²,占总耕地面积的84%。其中小麦播种面积稍有下降,玉米、蔬菜播种面积显著增加,果树种植比例在山区增加、平原区减少。研究区多年平均灌溉需水量22.52×10⁸ m³,小麦、玉米、蔬菜、果树和其他作物分别占灌溉需水总量的58.6%、12.6%、5.8%、16.3%和6.7%,受播种面积增加影响,1970-2015年,蔬菜和果树需水显著上升。从空间上来看,灌溉需水总量在上游山区上升显著,而在平原区表现为下降;排除降水的年际波动后,研究区作物需水自1970年以来一直呈上升趋势,进入20世纪80年代中期,虽然整体上升减缓,但随农业播种总面积增加和蔬菜、水果需水增加影响,需水量整体呈缓慢上升趋势。因此,控制上游农业用水,种植低耗水作物、减少耗水作物的种植面积,是恢复雄安新区清水产流的关键。     

土地利用对水体营养物影响的研究进展

日益严重的水质污染威胁到人类健康与生存,水体富营养化是其中一大治理难题。流域土地利用深刻影响水体中的营养物,定量刻画两者关系,可有效指导土地利用优化以改善水体质量。在国内外研究的基础上,本文梳理了样地实验、统计分析、经验模型和机理模型等4类研究土地利用和水体营养物关系的方法,并分析了不同方法应用的优缺点。以往研究多侧重土地利用数量结构,对强度和空间分布的量化及其与水体营养物关系的模型构建等研究尚显不足,多从单一或部分信息进行松散研究,导致不同研究中土地利用对水体营养物的解释能力差异显著。本文着重综述土地利用类型、强度差异和空间分布等3个方面对水体营养物影响的研究进展,并阐述关于两者定量关系尺度效应的争议和不确定性。目前主要存在问题包括现有研究土地利用和水体营养物的关系手段不足、土地利用多组分信息和水体营养物关系规律不清和尺度效应不确定性等3方面。因此,本文以水体污染物的产生、迁移、转化等的生态水文过程为线索,提出土地利用多信息空间综合表达和量化研究框架作为核心突破口。应用该框架,未来围绕融合过程机理与经验统计的模型开发、富营养化过程关联的土地利用多信息综合量化和多尺度结构的构建等3个方面开展研究,旨在为丰富土地利用对水体营养物影响研究提供一定的参考价值。