The multifunctionality of urban farming: perceived benefits for neighbourhood improvement

Urban farming – a type of urban agriculture focused on entrepreneurial food production – serves multiple functions in neighbourhoods; yet these are not well delineated. Expectations for urban farming often centre on traditional measures of economic development, potentially overlooking other benefits. Through a qualitative case study conducted in Baltimore, Maryland, we sought to understand community perceptions regarding the ways in which urban farms can benefit cities. Interviews with residents, neighbourhood leaders, and urban farmers in three residential neighbourhoods with urban farms revealed the pathways by which community members view farms as improving neighbourhoods. Benefits stemmed from four primary changes urban farms made to study neighbourhoods: creation of public projects welcoming involvement, physical improvement of degraded space, production of local food, and creation of new businesses. These changes led to multiple perceived benefits including increased social connectedness, a transformed physical landscape, improved neighbourhood reputation, increased access to fresh produce, and educational, youth development, and employment opportunities. Our findings demonstrate the importance of a multifunctional paradigm that accounts for social and educational functions in assessing the value of urban farming and bring empirical evidence to the concept of multifunctional agriculture. Urban farms with strong social aims may appear to contribute little to economic development if measured using traditional indicators of success such as job creation or fiscal impacts, but provide numerous other benefits for community development.     

Monitoring Environmental Impact in the Upper Sonoran Lifestyle: A New Tool for Rapid Ecological Assessment

Characterized by expensive housing, high socioeconomic status, and topographic relief, Upper Sonoran Lifestyle communities are found primarily along the Wildland-Urban Interface (WUI) in the Phoenix, Arizona metro area. Communities like these sprawl into the wildlands in the United States Southwest, creating a distinct urban fringe. This article, through locational comparison, introduces and evaluates a new field assessment tool for monitoring anthropogenic impact on soil–vegetation interactions along the well-maintained multi-use recreational trails in Upper Sonoran Lifestyle region. Comparing data from randomly selected transects along other multi-use trails with data from a control site revealed three key indicators of anthropogenic disturbances on soil–vegetation interactions: soil disturbance, vegetation disturbance, and vegetation density. Soil and vegetation disturbance displayed an average distance decay exponent factor of −0.60, while vegetation density displayed a reverse decay average of 0.60. Other important indicators of disturbance included vegetation type, biological soil crusts, and soil bulk density. The predictive ability of this new field tool enhances its applicability, offering a powerful rapid ecological assessment method for monitoring long-term anthropogenic impact in the Upper Sonoran Lifestyle, and other sprawling cities along the WUI.     

可靠性技术的发展与应用

本文介绍了可靠性标准体系与参数体系,可靠性的分析与设计方法,可靠性试验的发展趋势,指出可靠性管理是产品可靠性工作的核心,以及提高电子设备可靠性的发展策略。     

Incorporating Uncertainty Into the Ranking of SPARROW Model Nutrient Yields From Mississippi/Atchafalaya River Basin Watersheds1

Abstract: Excessive loads of nutrients transported by tributary rivers have been linked to hypoxia in the Gulf of Mexico. Management efforts to reduce the hypoxic zone in the Gulf of Mexico and improve the water quality of rivers and streams could benefit from targeting nutrient reductions toward watersheds with the highest nutrient yields delivered to sensitive downstream waters. One challenge is that most conventional watershed modeling approaches (e.g., mechanistic models) used in these management decisions do not consider uncertainties in the predictions of nutrient yields and their downstream delivery. The increasing use of parameter estimation procedures to statistically estimate model coefficients, however, allows uncertainties in these predictions to be reliably estimated. Here, we use a robust bootstrapping procedure applied to the results of a previous application of the hybrid statistical/mechanistic watershed model SPARROW (Spatially Referenced Regression On Watershed attributes) to develop a statistically reliable method for identifying “high priority” areas for management, based on a probabilistic ranking of delivered nutrient yields from watersheds throughout a basin. The method is designed to be used by managers to prioritize watersheds where additional stream monitoring and evaluations of nutrient‐reduction strategies could be undertaken. Our ranking procedure incorporates information on the confidence intervals of model predictions and the corresponding watershed rankings of the delivered nutrient yields. From this quantified uncertainty, we estimate the probability that individual watersheds are among a collection of watersheds that have the highest delivered nutrient yields. We illustrate the application of the procedure to 818 eight‐digit Hydrologic Unit Code watersheds in the Mississippi/Atchafalaya River basin by identifying 150 watersheds having the highest delivered nutrient yields to the Gulf of Mexico. Highest delivered yields were from watersheds in the Central Mississippi, Ohio, and Lower Mississippi River basins. With 90% confidence, only a few watersheds can be reliably placed into the highest 150 category; however, many more watersheds can be removed from consideration as not belonging to the highest 150 category. Results from this ranking procedure provide robust information on watershed nutrient yields that can benefit management efforts to reduce nutrient loadings to downstream coastal waters, such as the Gulf of Mexico, or to local receiving streams and reservoirs.     

Liquefaction process for a hydrothermally treated waste mixture containing plastics

Most landfilled plastic waste is a mixture or is in the form of composites with incombustible wastes such as glass, metals, and ceramics. After hydrothermal treatment, including a steam-explosion process, the separation of mixed waste (MW) into organic and inorganic substances becomes easy. However, the effect of hydrothermal pretreatment on the subsequent liquefaction of organic substances from MW is not obvious. In this study, the effects on the liquefaction of polystyrene and high-density polyethylene are discussed. Moreover, optimum conditions for the liquefaction of organic substances from hydrothermally treated MW are identified. By means of this hydrothermal pretreatment, including the steam-explosion process, polystyrene and high-density polyethylene can be significantly converted to oil by liquefaction at 300°–400°C. In comparison with liquefaction of hydrothermally pretreated mixed waste (HMW) at 300°–400°C with a batch type reactor, the yield of oil increases significantly on liquefaction using a semi-batch type reactor. It is considered that the radical chain and termination reactions among the radicals from HMW were inhibited in the semi-batch type reactor. On liquefaction of HMW in a semi-batch reactor, the conversion of HMW to oil was enhanced on increasing the liquefaction temperature to 350°C and the holding time to 60 min. Chemical Feedstock Recycling & Other Innovative Recycling Techniques 6     

Best Practices in Environmental Communication: A Case Study of Louisiana's Coastal Crisis

This mixed-method case study of environmental communication best practices in Louisiana, USA, identifies trends and approaches as informed by environmental psychology. The results provide key insights for environmental communicators, especially communicators in coastal regions. In-depth interviews with both environmental psychologists and environmental communicators showed that both groups emphasized knowing the audience, telling local stories, building relationships with target audiences and targeted messaging. Both psychologists and communicators also frequently mentioned general messaging concerns of source credibility, avoiding controversial terms and talking about issues, impacts and solutions to which the target audience can relate. A representative survey revealed that Louisiana residents are most interested in hearing about how environmental issues such as climate change, coastal land loss and flooding are affecting their own communities. This finding supports the idea that environmental communicators could do a better job tapping into strong place attachment and sense of community among coastal residents to promote action.     

Effectiveness of Africa's tropical protected areas for maintaining forest cover

The effectiveness of parks for forest conservation is widely debated in Africa, where increasing human pressure, insufficient funding, and lack of management capacity frequently place significant demands on forests. Tropical forests house a substantial portion of the world's remaining biodiversity and are heavily affected by anthropogenic activity. We analyzed park effectiveness at the individual (224 parks) and national (23 countries) level across Africa by comparing the extent of forest loss (as a proxy for deforestation) inside parks to matched unprotected control sites. Although significant geographical variation existed among parks, the majority of African parks had significantly less forest loss within their boundaries (e.g., Mahale Park had 34 times less forest loss within its boundary) than control sites. Accessibility was a significant driver of forest loss. Relatively inaccessible areas had a higher probability (odds ratio >1, p < 0.001) of forest loss but only in ineffective parks, and relatively accessible areas had a higher probability of forest loss but only in effective parks. Smaller parks less effectively prevented forest loss inside park boundaries than larger parks (T = ?2.32, p < 0.05), and older parks less effectively prevented forest loss inside park boundaries than younger parks (F_2,154 = ?4.11, p < 0.001). Our analyses, the first individual and national assessment of park effectiveness across Africa, demonstrated the complexity of factors (such as geographical variation, accessibility, and park size and age) influencing the ability of a park to curb forest loss within its boundaries.     

环境污染物导致氧化应激的关键信号通路及其检测方法

环境污染物能够以多种途径进入生物体内,在体内产生含氧自由基等活性氧物质,并通过多种信号通路及酶反应引起氧化应激,造成生物体内的脂质过氧化、蛋白质损伤、DNA表达改变、酶失活等,从而引发心血管疾病、风湿类疾病、感染及癌症等的发生。本文对环境污染物致氧化应激产生的原因、涉及的信号通路及酶反应、造成的危害,以及常见的基于细胞模型的氧化应激检测方法进行了综述,期望为评价环境污染物和检测氧化损伤提供参考。     

Extraction and clean-up methods for organochlorine pesticides determination in milk

Organochlorine pesticides (OCPs) can cause environmental damage and human health risks since they are lipophilic compounds with high resistance to degradation and long half-lives in humans. As most persistent OCPs have been banned years ago, it is expected to find these compounds at trace levels in environment. Therefore, increasingly sensitive and reliable analytical techniques are required to ensure effective monitoring of these compounds. The aim of this review is to discuss extraction and clean-up methods used to monitor OCP residues in milk, reported in the last 20 years. To carry out this review, an exhaustive bibliographic review was conducted. Despite the disadvantages of conventional extraction and clean-up methods, such as liquid–liquid, solid-phase or Soxhlet extractions, these procedures are still used due to their reliability. New extraction methods, like solid-phase microextraction, matrix solid-phase dispersion or QuEChERS, have not been thoroughly evaluated for OCP determination in milk. Almost all the methodologies analyzed in this review presented good performance characteristics according to the performance acceptability criteria set in SANCO’s procedure. Comparison between limits of quantification (LOQ) and detection (LOD), for the reported methodologies, is not always possible due to the heterogeneity of the units. Thus, researchers should take into account an homogenization of LOD and LOQ units, according to the international regulations and MRLs established. Finally, more research is necessary to obtain the ideal methodology for OCPs determination in milk, which comprises the environmentally friendly characteristics of the new techniques and the reliability of the traditional methodologies.     

大气细粒子(PM2.5)监测技术进展

大气细粒子(PM2.5)的污染对人和生态环境等影响巨大,迫切需要进行PM2.5质量浓度的监测;本文介绍了PM2.5国内外监测研究进展、监测网络应用情况以及监测技术;重点介绍了几种先进的技术:β射线法、振荡天平法和光散射法,并详细描述了各种监测设备的原理及结构,提出最好采用PM2.5在线监测仪进行日常监测。