Antibacterial and Drug Elution Performance of Thermoplastic Blends

Food preservatives or drug compounds can be eluted from polymer substrates to prevent the occurrence of hospital-acquired infections and food spoilage. We investigated the antimicrobial and drug-elution properties of the albumin and zein thermoplastic blends plasticized with glycerol and mixed with varying amounts of low-density polyethylene (LDPE), food preservatives (sodium benzoate or sodium nitrite), and drugs (ampicillin or ciprofloxacin). Bacillus subtilis and Escherichia coli were utilized as Gram (+) and Gram (?) species, respectively, for antimicrobial and drug-elution analyses, since these species are common in the human body and in food environments. The amount of contamination occurring in food and medical applications could be limited with usage of plastic blends made from thermomechanical molding of proteins (albumin from hen egg white and zein from corn), drug eluting compounds, and low-density polyethylene.     

‘Subjective resilience’: using perceptions to quantify household resilience to climate extremes and disasters

How should we measure a household’s resilience to climate extremes, climate change or other evolving threats? As resilience gathers momentum on the international stage, interest in this question continues to grow. So far, efforts to measure resilience have largely focused on the use of ‘objective’ frameworks and methods of indicator selection. These typically depend on a range of observable socio-economic variables, such as levels of income, the extent of a household’s social capital or its access to social safety nets. Yet while objective methods have their uses, they suffer from well-documented weaknesses. This paper advocates for the use of an alternative but complementary method: the measurement of ‘subjective’ resilience at the household level. The concept of subjective resilience stems from the premise that people have an understanding of the factors that contribute to their ability to anticipate, buffer and adapt to disturbance and change. Subjective household resilience therefore relates to an individual’s cognitive and affective self-evaluation of their household’s capabilities and capacities in responding to risk. We discuss the advantages and limitations of measuring subjective household resilience and highlight its relationships with other concepts such as perceived adaptive capacity, subjective well-being and psychological resilience. We then put forward different options for the design and delivery of survey questions on subjective household resilience. While the approach we describe is focused at the household level, we show how it has the potential to be aggregated to inform sub-national or national resilience metrics and indicators. Lastly, we highlight how subjective methods of resilience assessment could be used to improve policy and decision-making. Above all, we argue that, alongside traditional objective measures and indicators, efforts to measure resilience should take into account subjective aspects of household resilience in order to ensure a more holistic understanding of resilience to climate extremes and disasters.     

Securing our energy future: three international perspectives on microgrids and distributed renewables as a path toward resilient communities

ABSTRACT

This paper will examine three diverse microgrid cases in the US, Canada, and the European Union. The paper will explore how microgrids can help build resilient communities, facilitate distributed renewable energy, and ultimately lead to a secure energy future. The cases will include both urban and remote settings and compare the social, legal, and policy lessons learned from these cases to advance microgrid policy for long-term community resilience.     

多种聚氧乙烯牛脂胺混合物MON 0818的水生环境危害评估：脉冲暴露后沉积物、温度和恢复能力的影响

我们对一种商业表面活性剂混合物(多种聚氧乙烯牛脂胺)MON 0818进行了一系列毒性测试：1. 测定底栖无脊椎动物和鱼类在沉积物存在的情况下受到的毒性;2.测定大型蚤(Daphnia magna)和4种初级生产者经过24 h的脉冲暴露之后的恢复能力;3.鉴定水体温度上升对于2种冷水鱼类所受到MON 0818毒性的潜在影响。在沉积物存在的情况下,5种生物中有3种在最高10 mg/L的浓度下短期(24 h)死亡率为零。其余2种物种的中位有效浓度则显著高于仅对水体进行测试的结果。15 ℃下北极红点鲑(Salvelinus alpinus)的半数有效浓度统计上低于10 ℃下。绿藻(Rhabdocelis subcapitata)和普通小球藻(Chlorella vulgaris)在经过24 h 1 mg/L的暴露后的恢复期中显示出生长延迟的状况,表明该暴露可能存在潜在影响。尽管如此,2个物种的最大绝对生长速率并未改变,表明其均可恢复。1.5 mg/L下的蝾螈共生藻(Oophila sp.)和100 mg/L下的浮萍(Lemna minor)经过24 h的暴露并未显示显著反应。24 h 5 mg/L暴露之后的恢复期中,大型蚤显示出潜在的死亡率。然而存活个体的生殖终端指标并未受到影响。结果表明在沉积物的存在下MON 0818的快速损耗可以减轻对于被暴露生物的效果,在不小于环境中可能出现的MON 0818浓度情况下,24 h暴露以后的生物的完全恢复是可能的。
精选自Jose L. Rodriguez-Gil, Ryan Prosser, Gregory Hanta, David Poirier, Linda Lissemore, Mark Hanson, Keith R. Solomon. Aquatic hazard assessment of MON 0818, a commercial mixture of alkylamine ethoxylates commonly used in glyphosate-containing herbicide formulations. Part 2: Roles of sediment, temperature, and capacity for recovery following a pulsed exposure. Environmental Toxicology and Chemistry: Volume 36, Issue 2, pages 512–521, July 2017. DOI: 10.1002/etc.3558
详情请见http://onlinelibrary.wiley.com/wol1/doi/10.1002/etc.3558/full
     

Impact of riparian zone protection from cattle on nutrient, bacteria, F-coliphage, and loading of an intermittent stream

This 5-yr study compared, via an upstream-downstream experimental design, nutrient and microbial water quality of an intermittent stream running through a small pasture (～2.5 animals ha) where cattle are restricted from the riparian zone (restricted cattle access [RCA]) and where cattle have unrestricted access to the stream (unrestricted cattle access [URCA]). Fencing in the RCA excluded pasturing cattle to within ～3 to 5 m of the stream. Approximately 88% (26/32) of all comparisons of mean contaminant load reduction for lower, higher, and all stream flow conditions during the 5-yr study indicated net contaminant load reductions in the RCA; for the URCA, this percentage was 38% (12/32). For all flow conditions, mean percent load reductions in the RCA for nutrients and bacteria plus F-coliphage were 24 and 23%, respectively. These respective percentages for the URCA were -9 and -57% (positive values are reductions; negative values are increases). However, potentially as a result of protected wildlife habitat in the RCA, the mean percent load reduction for for "all flow" was -321% for the RCA and 60% for the URCA; for , these respective percentages were -209% (RCA) and 73% (URCA). For "all flow" situations, mean load reductions for the RCA were significantly greater ( < 0.1) than those from the URCA for NH-N, dissolved reactive phosphorus (DRP), total coliform, , and . For "high flow" situations, mean load reductions were significantly greater for the RCA for DRP, total coliform, and . For "low flow" conditions, significantly greater mean load reductions were in favor of the RCA for DRP, total P, total coliforms, fecal coliforms, , and . In no case were mean pollutant loads in the URCA significantly higher than RCA pollutant loads. Restricting pasturing livestock to within 3 to 5 m of intermittent streams can improve water quality; however, water quality impairment can occur if livestock have unrestricted access to a stream.     

Permeability measurement and scan imaging to assess clogging of pervious concrete pavements in parking lots

This paper describes a study that used permeability measurement along with physical and hydrological characteristics of 20 pervious concrete pavements in parking lots throughout California. The permeability was measured at five locations: the main entrance, an area with no traffic, and three separate measurements within a parking space at each parking lot. Hydrological and physical site characteristics such as traffic flow, erosion, vegetation cover, sediments accumulation, maintenance practice, presence of cracking, rainfall, and temperature data were also collected for each parking lot. These data were used to perform detailed statistical analysis to determine factors influencing changes in permeability and hence assessing possible cause of clogging. In addition, seven representative core samples were obtained from four different parking lots with permeability ranging from very low to very high. Porosity profiles produced from CT scanning were used to assess the possible nature and extent of clogging. Results showed that there is a large variation in permeability within each parking lot and between different parking lots. In general, the age of the parking lot is the predominant factor influencing the permeability. Statistical analysis revealed that fine sediment (particles less than 38 μm) mass is also an important influencing factor. Other influencing factors with lower significance included number of days with a temperature greater than 30°C and the amount of vegetation next to the parking lot. The combined scanned image analysis and porosity profile of the cores showed that most clogging occurs near the surface of the pavement. While lower porosity generally appeared to be limited to the upper 25 mm, in some core samples evidence of lower porosity was found up to 100mm below the surface.     

Mission impossible?: Adopting a CSR-based business model for extractive industries in developing countries

Corporations in the extractive industries often state their commitment to “corporate social responsibility” principles, but their actual implementation of these principles, particularly in developing countries, is questionable. This contradiction between rhetoric and reality is attributable to the fact that these companies have not fully integrated CSR into their business models. This can been seen in assessments of projects' costs and benefits, project and technology selection, respect for community consent, and performance incentive structures. The Marlin gold mine in Guatemala provides a concrete example of these sharp contradictions between stated CSR commitments and actual performance.     

The Harvest and Management of Migratory Bird Eggs by Inuit in Nunatsiavut, Labrador

This paper presents the results of collaborative research conducted in 2007 on the harvest of migratory bird eggs by Inuit households of Nunatsiavut, Labrador. Harvest variability between communities and species is examined, as is the social and ecological factors affecting the 2007 Inuit egg harvest. Representing the first comprehensive account of Inuit egg use in Labrador, this information should be valuable to agencies responsible for managing migratory bird populations in North America and will contribute to a more informed understanding of the complexity and temporal variability in subsistence harvesting among Labrador Inuit. It is argued that the recognition of this complexity will be critical as the Nunatsiavut Government and other wildlife management agencies formulate management policies that are supportive rather, than constraining, to Inuit resource use in the future.     

Enhanced UV-B and elevated CO(2) impacts sub-arctic shrub berry abundance, quality and seed germination

This study investigated the effects of long-term-enhanced UV-B, and combined UV-B with elevated CO(2) on dwarf shrub berry characteristics in a sub-arctic heath community. Germination of Vaccinium myrtillus was enhanced in seeds produced at elevated UV-B, but seed numbers and berry size were unaffected. Elevated UV-B and CO(2) stimulated the abundance of V. myrtillus berries, whilst UV-B alone stimulated the berry abundance of V. vitis-idaea and Empetrum hermaphroditum. Enhanced UV-B reduced concentrations of several polyphenolics in V. myrtillus berries, whilst elevated CO(2) increased quercetin glycosides in V. myrtillus, and syringetin glycosides and anthocyanins in E. hermaphroditum berries. UV-B?×?CO(2) interactions were found for total anthocyanins, delphinidin-3-hexoside and peonidin-3-pentosidein in V. myrtillus berries but not E. hermaphroditum. Results suggest positive impacts of UV-B on the germination of V. myrtillus and species-specific impacts of UV-B?×?elevated CO(2) on berry abundance and quality. The findings have relevance and implications for human and animal consumers plus seed dispersal and seedling establishment.     

Enhanced UV-B and Elevated CO<Subscript>2</Subscript> Impacts Sub-Arctic Shrub Berry Abundance,Quality and Seed Germination

This study investigated the effects of long-term-enhanced UV-B, and combined UV-B with elevated CO₂ on dwarf shrub berry characteristics in a sub-arctic heath community. Germination of Vaccinium myrtillus was enhanced in seeds produced at elevated UV-B, but seed numbers and berry size were unaffected. Elevated UV-B and CO₂ stimulated the abundance of V. myrtillus berries, whilst UV-B alone stimulated the berry abundance of V. vitis-idaea and Empetrum hermaphroditum. Enhanced UV-B reduced concentrations of several polyphenolics in V. myrtillus berries, whilst elevated CO₂ increased quercetin glycosides in V. myrtillus, and syringetin glycosides and anthocyanins in E. hermaphroditum berries. UV-B × CO₂ interactions were found for total anthocyanins, delphinidin-3-hexoside and peonidin-3-pentosidein in V. myrtillus berries but not E. hermaphroditum. Results suggest positive impacts of UV-B on the germination of V. myrtillus and species-specific impacts of UV-B × elevated CO₂ on berry abundance and quality. The findings have relevance and implications for human and animal consumers plus seed dispersal and seedling establishment.