Tracking Cholera in Coastal Regions Using Satellite Observations1

Jutla, Antarpreet S., Ali S. Akanda, and Shafiqul Islam, 2010. Tracking Cholera in Coastal Regions Using Satellite Observations. Journal of the American Water Resources Association (JAWRA) 46(4): 651-662. DOI: 10.1111/j.1752-1688.2010.00448.x Abstract: Cholera remains a significant health threat across the globe. The pattern and magnitude of the seven global pandemics suggest that cholera outbreaks primarily originate in coastal regions and then spread inland through secondary means. Cholera bacteria show strong association with plankton abundance in coastal ecosystems. This review study investigates the relationship(s) between cholera incidence and coastal processes and explores utility of using remote sensing data to track coastal plankton blooms, using chlorophyll as a surrogate variable for plankton abundance, and subsequent cholera outbreaks. Most studies over the last several decades have primarily focused on the microbiological and epidemiological understanding of cholera outbreaks. Accurate identification and mechanistic understanding of large scale climatic, geophysical, and oceanic processes governing cholera-chlorophyll relationship is important for developing cholera prediction models. Development of a holistic understanding of these processes requires long and reliable chlorophyll datasets, which are beginning to be available through satellites. We have presented a schematic pathway and a modeling framework that relate cholera with various hydroclimatic and oceanic variables for understanding disease dynamics using the latest advances in remote sensing. Satellite data, with its unprecedented spatial and temporal coverage, have potentials to monitor coastal processes and track cholera outbreaks in endemic regions.     

Constructing an Interdisciplinary Flow Regime Recommendation1

Bartholow, John M., 2010. Constructing an Interdisciplinary Flow Regime Recommendation. Journal of the American Water Resources Association (JAWRA) 1-15. DOI: 10.1111/j.1752-1688.2010.00461.x Abstract: It is generally agreed that river rehabilitation most often relies on restoring a more natural flow regime, but credibly defining the desired regime can be problematic. I combined four distinct methods to develop and refine month-by-month and event-based flow recommendations to protect and partially restore the ecological integrity of the Cache la Poudre River through Fort Collins, Colorado. A statistical hydrologic approach was used to summarize the river’s natural flow regime and set provisional monthly flow targets at levels that were historically exceeded 75% of the time. These preliminary monthly targets were supplemented using results from three Poudre-specific disciplinary studies. A substrate maintenance flow model was used to better define the high flows needed to flush accumulated sediment from the river’s channel and help sustain the riparian zone in this snowmelt-dominated river. A hydraulic/habitat model and a water temperature model were both used to better define the minimum flows necessary to maintain a thriving cool water fishery. The result is a range of recommended monthly flows and daily flow guidance illustrating the advantage of combining a wide range of available disciplinary information, supplemented by judgment based on ecological principles and a general understanding of river ecosystems, in a highly altered, working river.     

生态文明对图书管理的影响及对策措施

生态文明是社会主义文明的组成部分之一,是社会文明发展的新阶段.生态文明使有关图书的重要性更加突出,数量激增,涉及的范围更加广泛,类型更加复杂多样.因此,图书管理应以生态文明为指导,为生态文明建设服务,采取高度重视,调整、增加分类,开设专柜、专室,及时向读者提供有关信息等措施.     

Modeling Streams and Hydrogeomorphic Attributes in Oregon From Digital and Field Data1

Abstract: Managers, regulators, and researchers of aquatic ecosystems are increasingly pressed to consider large areas. However, accurate stream maps with geo‐referenced attributes are uncommon over relevant spatial extents. Field inventories provide high‐quality data, particularly for habitat characteristics at fine spatial resolutions (e.g., large wood), but are costly and so cover relatively small areas. Recent availability of regional digital data and Geographic Information Systems software has advanced capabilities to delineate stream networks and estimate coarse‐resolution hydrogeomorphic attributes (e.g., gradient). A spatially comprehensive coverage results, but types of modeled outputs may be limited and their accuracy is typically unknown. Capitalizing on strengths in both field and regional digital data, we modeled a synthetic stream network and a variety of hydrogeomorphic attributes for the Oregon Coastal Province. The synthetic network, encompassing 96,000 km of stream, was derived from digital elevation data. We used high‐resolution but spatially restricted data from field inventories and streamflow gauges to evaluate, calibrate, and interpret hydrogeomorphic attributes modeled from digital elevation and precipitation data. The attributes we chose to model (drainage area, mean annual precipitation, mean annual flow, probability of perennial flow, channel gradient, active‐channel width and depth, valley‐floor width, valley‐width index, and valley constraint) have demonstrated value for stream research and management. For most of these attributes, field‐measured, and modeled values were highly correlated, yielding confidence in the modeled outputs. The modeled stream network and attributes have been used for a variety of purposes, including mapping riparian areas, identifying headwater streams likely to transport debris flows, and characterizing the potential of streams to provide high‐quality habitat for salmonids. Our framework and models can be adapted and applied to areas where the necessary field and digital data exist or can be obtained.     

Microbial community dynamics in uranium contaminated subsurface sediments under biostimulated conditions with high nitrate and nickel pressure

BACKGROUND, AIM, AND SCOPE: The subsurface at the Oak Ridge Field Research Center represents an extreme and diverse geochemical environment that places different stresses on the endogenous microbial communities, including low pH, elevated nitrate concentrations, and the occurrence of heavy metals and radionuclides, including hexavalent uranium [U(VI)]. The in situ immobilization of U(VI) in the aquifer can be achieved through microbial reduction to relatively insoluble U(IV). However, a high redox potential due to the presence of nitrate and the toxicity of heavy metals will impede this process. Our aim is to test biostimulation of the endogenous microbial communities to improve nitrate reduction and subsequent U(VI) reduction under conditions of elevated heavy metals. MATERIALS AND METHODS: Column experiments were used to test the possibility of using biostimulation via the addition of ethanol as a carbon source to improve nitrate reduction in the presence of elevated aqueous nickel. We subsequently analyzed the composition of the microbial communities that became established and their potential for U(VI) reduction and its in situ immobilization. RESULTS: Phylogenetic analysis revealed that the microbial population changed from heavy metal sensitive members of the actinobacteria, alpha- and gamma-proteobacteria to a community dominated by heavy metal resistant (nickel, cadmium, zinc, and cobalt resistant), nitrate reducing beta- and gamma-proteobacteria, and sulfate reducing Clostridiaceae. Coincidentally, synchrotron X-ray absorption spectroscopy analyses indicated that the resulting redox conditions favored U(VI) reduction transformation to insoluble U(IV) species associated with soil minerals and biomass. DISCUSSION: This study shows that the necessary genetic information to adapt to the implemented nickel stress resides in the endogenous microbial population present at the Oak Ridge FRC site, which changed from a community generally found under oligotrophic conditions to a community able to withstand the stress imposed by heavy metals, while efficiently reducing nitrate as electron donor. Once nitrate was reduced efficient reduction and in situ immobilization of uranium was observed. CONCLUSIONS: This study provides evidence that stimulating the metabolism of the endogenous bacterial population at the Oak Ridge FRC site by adding ethanol, a suitable carbon source, results in efficient nitrate reduction under conditions of elevated nickel, and a decrease of the redox potential such that sulfate and iron reducing bacteria are able to thrive and create conditions favorable for the reduction and in situ immobilization of uranium. Since we have found that the remediation potential resides within the endogenous microbial community, we believe it will be feasible to conduct field tests. RECOMMENDATIONS AND PERSPECTIVES: Biostimulation of endogenous bacteria provides an efficient tool for the successful in situ remediation of mixed-waste sites, particularly those co-contaminated with heavy metals, nitrate and radionuclides, as found in the United States and other countries as environmental legacies of the nuclear age.     

人员疏散拥堵问题的博弈分析

从经济学的角度,应用博弈论中经典的"公共地悲剧"理论,分析疏散出口、安全通道等没有排他性所有权的稀缺性资源供给与需求之间的矛盾,提出了人员疏散过程中的博弈数学模型,揭示在理性的疏散人员追求自身收益最大化和没有有效约束与管制的前提条件下,疏散出口等公共资源会被过度使用的现象,即人员疏散过程中的"公共地悲剧"——人员拥堵,并在所提出的博弈模型基础上,从设计与管理的角度,给出一些解决拥堵问题的建议和对策。     

大空间建筑室内火蔓延全尺寸实验设计

大空间建筑室内火蔓延的全尺寸实验能较好反应和说明大空间建筑室内火灾过程的主要规律,也是当前研究建筑室内火灾机理较理想的一种实验方法。文中介绍了大空间建筑室内火蔓延全尺寸实验室的设计思想和实现方法,简要介绍了其在建筑火灾研究中的主要应用前景。     

低碳城市和创新型城市双试点效果评估——基于绿色经济转型视角

全面系统评估环境规制政策协同效应对绿色经济效率的影响,对于推动生态文明建设具有重要的意义。文章基于2006—2020年281个地级市的样本数据,运用多期双重差分模型评估双试点政策对绿色经济效率的影响。研究发现：(1)相比于非试点城市,双试点政策的实施使试点城市的绿色经济效率提升约8.29%,此结论在经过平行趋势等稳健性检验后依旧成立;(2)双试点政策比单试点政策更能显著提高绿色经济效率,政策间存在协同效应;(3)双试点政策通过创新型和改进型绿色技术创新、降低能源消费强度促进绿色经济效率,同时会增加能源消费规模进而抑制绿色经济效率;(4)双试点政策对周围100～900 km以内区域的绿色经济效率产生显著的正向空间溢出效应。本文丰富了环境政策协同对绿色经济效率的影响研究,为政策的有效实施、推动减污降碳协同增效提供科学支持。     

基于可持续发展的物流运输绿色化的途径与方法分析——以SHARP公司的绿色运输实践为例

由于物流运输绿色化的目的主要在于通过有效的物流系统的规划与控制,在保证物流服务目标的前提下,尽量地去降低运输中的能量消耗和各种废弃物的排放以及运输工具对道路的占用;因此实践中不仅要贯彻和坚持安全性、及时与准确性、经济效益与环境效益相统一以及人与车辆管理的一体化等四方面的原则,而且还在通过技术进步以切实降低各种运输方式对环境的影响、建立起对汽车驾驶员的培训及绩效管理体系、在城市物流系统的合理规划等几个方面进行努力.     

生存空间相对性的再研究

生存空间可分为狭义和广义两种,狭义生存空间的特点是有限性和潜在性,扩展性或相对性则是广义生存空间的最大特征;对生存空间的分类研究,有助于某一国家或地区生存现状和发展潜力的评价;人们通过贸易,交换着各自的生存空间;发展经济和科学技术,合理分配生活和生产空间,保护环境,控制人口,以及对资源的合理分配,是人类保护和扩大生存空间努力的基本方面。