关于城市规划与设计中生态作用的研究

在城市建设中城市的规划是其总纲领,是其实行生态城市建设主要基础,当代的发展城市规建凸显出非常重要的效用。但是从目前的形势上看,在中国的城市建设规划与策划生态城市的发展中,为追求当前的效益却忽略了未来空气质量的对人们的益处,从而造成极大的环境污染和破坏,不但阻碍了建设生态城市化的进程,而且造成对环境与生活负面的作用。所以,须增加对生态环境城市的了解,重视城市规划的设计,利用可再生的自然资源,来对城市生态系统进行优化,改良居民居住环境,为建设绿色城市、宜居建筑提供有力的保证。本文对生态城市规划与设计中的作用展开探究。

Mechanisms of therapeutic effects of rhubarb on gut origin sepsis

It is proposed that gut-liver-lung axis plays an important role in the pathophysiologic development of the critical illness, and it induces excessive inflammatory response in vivo and multiple organ dysfunction syndrome. The mechanisms of therapeutic effects of rhubarb on critical patients are studied based on the theory of Chinese traditional medicine. Researches demonstrate that rhubarb can be used to protect gut barrier, maintain intestinal microecological environment and prevent bacterial translocation. It also can be used to inhibit the release of inflammatory mediators by liver inflammatory-effector cells, reduce inflammatory reaction in the liver and protect hepatic cell functions. Furthermore, rhubarb can be used to reduce pulmonary vascular permeability and extenuate pulmonary edema, inhibit the release of neutrophil myeloperoxidase, and lower the level of inflammatory response and decrease inflammatory mediators in circulation. The above results indicate that rhubarb may interrupt or partly interrupt the gut-liver-lung axis after trauma and reduce the intensity of systemic inflammatory response syndrome. Therefore, rhubarb may obviously lower the incidence of multiple organ dysfunction syndrome and be used to prevent and treat systemic inflammatory response syndrome and multiple organ dysfunction syndrome after trauma.

Interactive effects of metal pollution and ocean acidification on physiology of marine organisms

Changes in the global environment such as ocean acidification （OA） may interact with anthropogenic pollutants including trace metals threatening the integrity of marine ecosystems. We analyze recent studies on the interactive effects of OA and trace metals on marine organisms with a focus on the physiological basis of these interactions. Our analysis shows that the responses to elevated CO2 and metals are strongly dependent on the species, developmental stage, metal biochemistry and the degree of environmental hypercapnia, and cannot be directly predicted from the CO2-induced changes in metal solubility and speciation. The key physiological functions affected by both the OA and trace metal exposures involve acid-base regulation, pro- tein turnover and mitochondrial bioenergetics, reflecting the sensitivity of the underlying molecular and cellular pathways to CO2 and metals. Physiological interactions between elevated CO2 and metals may impact the organisms＇ capacity to maintain ac- id-base homeostasis and reduce the amount of energy available for fitness-related functions such as growth, development and re- production thereby affecting survival and performance of estuarine populations. Environmental hypercapnia may also affect the marine food webs by altering predator-prey interactions and the trophic transfer of metals in the food chain. However, our under- standing of the degree to which these effects can impact the function and integrity of marine ecosystems is limited due the scar- city of the published research and its bias towards certain taxonomic groups. Future research priorities should include studies of metal x Pco2 interactions focusing on critical physiological functions （including acid-base, protein and energy homeostasis） in a greater range of ecologically and economically important marine species, as well as including the field populations naturally ex- posed （and potentially adapted） to different levels of metals and CO2 in their environments [Current Zoology 61 （4）： 653-668, 2015].

Changes in niche differentiation and environmental filtering over a hydric stress gradient

Aims Diversity in communities is determined by species’ability to coexist with each other and to overcome environmental stress that may act as an environmental filter.Niche differentiation(ND)results in stronger intra-than interspecific competition and promotes coexistence.Because stress affects interactions,the strength of ND may change along stress gradients.A greater diversity of plant growth forms has been observed in stressful habitats,such as deserts and alpine regions,suggesting greater ND when stress is strong.We tested the hypothesis that niche differences and environmental filters become stronger with stress.Methods In a semiarid grassland in southern Mexico,we sowed six annual species in the field along a hydric stress gradient.Plants were grown alone(without interactions),with conspecific neighbors(intraspecific interactions)or with heterospecific neighbors(interspecific interactions).We analyzed how the ratio of intra-to interspecific competition changed along the gradient to assess how water availability determines the strength of ND.We also determined if hydric stress represented an environmental filter.Important Findings We observed stronger intra-than interspecific competition,especially where hydric stress was greater.Thus,we found ND in at least some portion of the gradient for all but one species.Some species were hindered by stress,but others were favored by it perhaps because it eliminates soil pathogens.Although strong ND was slightly more frequent with stress,our species sample was small and there were exceptions to the general pattern,so further research is needed to establish if this is a widespread phenomenon in nature.