Health Security and Risk Aversion

Health security has become a popular way of justifying efforts to control catastrophic threats to public health. Unfortunately, there has been little analysis of the concept of health security, nor the relationship between health security and other potential aims of public health policy. In this paper I develop an account of health security as an aversion to risky policy options. I explore three reasons for thinking risk avoidance is a distinctly worthwhile aim of public health policy: (i) that security is intrinsically valuable, (ii) that it is necessary for social planning and (iii) that it is an appropriate response to decision‐making in contexts of very limited information. Striking the right balance between securing and maximizing population health thus requires a substantive, and hitherto unrecognized, value judgment. Finally, I critically evaluate the current health security agenda in light of this new account of the concept and its relationship to the other aims of public health policy.     

Livelihood diversification and implications on dryland resources of central Tanzania

The concern over sustainable livelihoods in African drylands is an issue that has received considerable attention from researchers and policy makers alike. Over the past two decades African rural areas have undergone rapid changes, whereby, rural income diversification has become the most salient feature. With a particular focus on dryland ecosystems, among the major challenges facing communities in these areas is recurrent drought leading to conditions of food insecurity. This paper draws on experience on coping mechanisms for food insecurity from an agro-pastoral community in Mvumi, located in the semiarid areas of central Tanzania. An understanding of livelihoods of people in this area has involved examining how communities have managed to adjust their livelihood in the midst of challenges resulting not only from drought but also from various forces such as socio–economic, political and ecological factors. It has been found out that, despite profound food crisis in this area, people are not always desperate and that there are possibilities for realizing some hidden potentials of dryland resources for livelihood diversification. The issue of sustainable natural resource management in such areas is, however, questionable because of some adverse environmental effects associated with some of the coping mechanisms.     

长江经济带生态安全测度研究

长江经济带城镇化发展迅速，但随之出现的诸多生态安全问题已严重制约其高质量发展。为综合特征指数法与指标体系法优势，并诠释社会经济与生态共生发展这一生态安全新内涵，在分析城镇化发展与自然生态相互作用基础上，选取2006年至2017年长江经济带沿线11个省市数据为研究样本，运用"驱动-压力-状态-影响-响应（DPSIR）"模型、R聚类法及变异系数法确定生态安全指标及其权重，再利用城镇化-自然生态Lotka-Volterra共生模型获得具备生态经济内涵的受力指数、综合特征指数，实现指标与指数的耦合，更进一步推导出生态安全预警依据。最后进行实证测度，并根据测度结果进行指标回溯分析生态安全问题成因，完成逆向解耦。研究结果表明：（1）2006-2017年长江经济带城镇化系统发展迅猛，尤其是城镇化驱动力得到强化，但长江经济带生态环境状况改善幅度并不明显且长期处于城镇化高速发展而生态环境遭受损害的偏害发展模式；（2）长江经济带11个省市生态安全格局差异显著，呈现"东西较高，中间偏低"格局；（3）通过指标回溯发现，产业结构发展不均衡、城镇人口过度扩张、城镇化子系统对生态环境空间的侵占等因素是造成长江经济带生态安全问题的重要原因。     

山水资源型城市景观生态风险评价及生态安全格局构建——以张家界市为例

区域生态安全是现代城市健康发展的重要内容，科学认识与评价区域生态风险与构建生态安全格局，有利于综合提升区域生态安全水平。以张家界市2019年高分二号遥感解译数据为基础，使用GIS空间分析与Fragstats软件构建景观生态风险指数，对景观生态风险空间分布特征进行分析；利用最小累积阻力模型(MCR),以9个自然保护地为生态源地，以景观生态风险指数、植被覆盖度、高程、坡度、与道路距离、与水域距离构建阻力面，识别生态廊道与生态节点，构建生态安全格局并提出生态安全保护策略。结果表明：(1)研究区景观生态风险空间差异明显，生态风险呈现“中部、四周低，高值区总体沿澧水水系呈条带状延伸”的空间分布规律；(2)低、较低、中、较高、高生态风险分别占比21.59%、41.79%、22.57%、12.08%、1.98%,其中较低生态风险占比最高，高生态风险占比最低，各区县高生态风险压力排序为：永定区>慈利县>桑植县>武陵源区；(3)研究共识别出生态廊道24条，生态节点47个，生态廊道累积长达872.35km,生态廊道与生态节点分别呈现“三横四纵”、“中多西少，南多北少”的空间分布特征；(4...     

浅议高校校园网的安全问题

从校园网的特点出发,针对当前存在的主要安全威胁以及内部安全威胁的表现形式,分析了校园网中存在的各种安全问题,并提出了以多种技术手段和管理手段加强校园网安全的应对策略。     

海岸带区域陆海统筹生态安全研究

海岸带既是区域经济发展的黄金地带，亦是陆海系统交互胁迫的敏感区域，快速城镇化与工业化导致海岸带关键生态系统服务受损、生态网络格局紊乱、珍稀物种安全保障空间萎缩等重大生态安全问题。以闽三角海岸带珍稀物种-栖息地系统为研究对象，从“多物种-多生境-多尺度”视角出发，基于陆海统筹理念系统评估了闽三角海岸带珍稀物种-栖息地系统的脆弱性，建立了基于物种水平的海岸带生态保护与修复网络，构建了海岸带陆海统筹生态安全“一张图”。研究结果表明：(1)高强度围填海驱动下，闽三角红树林与水鸟栖息地脆弱性显著增加，高脆弱区域主要集中于九龙江河口、厦门同安湾和泉州湾；(2)闽三角生态安全网络由12条水鸟迁徙廊道和11个生态节点组成，其中影响陆海统筹生态安全的生态节点4个，预警生态节点3个；(3)闽三角海岸带未来安全韧性生境(水鸟栖息地与文昌鱼、中国鲎低脆弱生境较密集的区域)分布于云霄红树林保护区、东山岛近岸、九龙江河口、厦门大嶝海域、围头湾、深沪湾。本研究能够为设计规划未来韧性海岸带“受损海水-滨海湿地-珍稀物种”一体化修复与保护的生态安全格局，保障陆海统筹生态安全提供理论支撑和一体化解决方案。     

In the Time of Frost: El Niño and the Political Ecology of Vulnerability in Papua New Guinea

ABSTRACT

Climatic anomalies associated with El Niño bring prolonged droughts and night-time frosts that devastate subsistence gardens in the Papua New Guinea highlands. As a customary process of adaptation to the subsequent food insecurity caused by crop-destroying frosts, people migrate to lower altitude areas where kin and friends provide sustenance and social support. However, with increasing economic development and the demise of collective kin endeavours in the region, long-distance migration networks no longer appear to offer people respite from food insecurity. In this paper, I examine the changes in social responses to El Niño-caused food shortages at varying scales – from subsistence farmers to international aid agencies – over the past several El Niño events. The paper explores the production of vulnerability when customary social-ecological systems of adaptation intersect with regional and national politics, development efforts, and humanitarian aid agencies.     

A procedure to introduce point mutations into the Rubisco large subunit gene in wild-type plants

Photosynthetic inefficiencies limit the productivity and sustainability of crop production and the resilience of agriculture to future societal and environmental challenges. Rubisco is a key target for improvement as it plays a central role in carbon fixation during photosynthesis and is remarkably inefficient. Introduction of mutations to the chloroplast-encoded Rubisco large subunit rbcL is of particular interest for improving the catalytic activity and efficiency of the enzyme. However, manipulation of rbcL is hampered by its location in the plastome, with many species recalcitrant to plastome transformation, and by the plastid's efficient repair system, which can prevent effective maintenance of mutations introduced with homologous recombination. Here we present a system where the introduction of a number of silent mutations into rbcL within the model plant Nicotiana tabacum facilitates simplified screening via additional restriction enzyme sites. This system was used to successfully generate a range of transplastomic lines from wild-type N. tabacum with stable point mutations within rbcL in 40% of the transformants, allowing assessment of the effect of these mutations on Rubisco assembly and activity. With further optimization the approach offers a viable way forward for mutagenic testing of Rubisco function in planta within tobacco and modification of rbcL in other crops where chloroplast transformation is feasible. The transformation strategy could also be applied to introduce point mutations in other chloroplast-encoded genes.     

整合多重生态保护目标的广东省生态安全格局构建

构建生态安全格局是缓解生态保护与经济发展之间的突出矛盾，保障可持续发展的有效空间途径。但目前生态安全格局的构建过于强调综合，简单叠加多种生态系统服务的方法忽视了不同服务间的权衡与协同关系，难以直接支撑不同目标下的生态保护决策。以广东省为例，重点关注生境维持、水源涵养、水质净化、粮食生产、土壤保持、洪水调节、沿海灾害缓解七种重要的生态系统服务，面向生物多样性保育、水资源利用、粮食生产、自然灾害防范等单一生态保护目标分别构建生态安全格局。研究结果表明，面向生物多样性保育目标的生态安全格局呈“双屏障带”式分布，生态源地主要分布在粤北生态发展区；面向水资源利用目标的水安全格局呈“五江一带”式分布，重点保护区主要位于河湖水库及周边绿地；面向粮食生产目标的生态源地主要分布在广东省东西两翼；面向自然灾害防范目标的生态源地在珠三角、湛江市、汕头市少有分布，集中在粤北生态发展区。基于多种生态系统服务综合重要性判定生态源地，并整合单一生态保护目标下的多重源地，识别综合生态源地共49536.10 km~2,主要分布在珠三角外围和粤北生态发展区。基于最小累积阻力模型和电路模型，识别了总长度2268.07 km...