Climate change refers to long-term shifts in weather conditions and patterns of extreme weather events. It may lead to changes in health threat to human beings, multiplying existing health problems. This review examines the scientific evidences on the impact of climate change on human infectious diseases. It identifies research progress and gaps on how human society may respond to, adapt to, and prepare for the related changes. Based on a survey of related publications between 1990 and 2015, the terms used for literature selection reflect three aspects--the components of infectious diseases, climate variables, and selected infectious diseases. Humans' vulnerability to the potential health impacts by climate change is evident in literature. As an active agent, human beings may control the related health effects that may be effectively controlled through adopting proactive measures, including better understanding of the climate change patterns and of the compound disease-specific health effects, and effective allocation of technologies and resources to promote healthy lifestyles and public awareness. The following adaptation measures are recommended: 1) to go beyond empirical observations of the association between climate change and infectious diseases and develop more scientific explanations, 2) to improve the prediction of spatial-temporal process of climate change and the associated shifts in infectious diseases at various spatial and temporal scales, and 3) to establish locally effective early warning systems for the health effects of predicated climate change.

A city and its transportation network are both complicated systems. Fractal geometry provides an effective way to describe the complex property of geographical features. This paper uses a modified box-counting method to describe the fractal property of urban transportation networks. Assuming that human settlements of different sizes are all operated by the same growth procedure, this paper investigates the relationship between the mass size of cities and the complexity of their road systems. The results confirm that, as cities grow from small to large, their transportation networks generally become more complicated—the urban spaces are filled up more densely by city roads and the locations within a city are more accessible. The quantitative relationship identified between the complexity of urban transportation network and city size provides an empirical guide for the planning and policymaking of urban development and road construction.