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961.
962.
Carrageenan-based films demonstrate good performance, the raw materials for their production are abundant in nature and can be sustainably sourced from seaweeds. Similar to other naturally-derived biopolymers, however, carrageenans are relatively expensive to purify and form into useful materials. In order to potentially lower the production costs compared to pure carrageenan, semi-refined carrageenan (SRC) plasticized with 0–50% (w/w) glycerol was investigated using a solution casting method. The film color and opacity increased along with the moisture content, whereas the water vapor permeability decreased with increasing levels of glycerol. The tensile properties of the SRC films improved significantly, particularly at glycerol additions greater than 30% (w/w). Moreover, the addition of glycerol improved the thermal stability and altered the surface morphology of the films. In general, the properties of the SRC films were comparable with refined carrageenan films suggesting that SRC has potential to be furthered developed into more cost effective primary food packaging materials.  相似文献   
963.
The semi-arid Amboseli landscape, southern Kenya, is characterised by intermittent groundwater-fed wetlands that form sedimentary geoarchives recording past ecosystem changes. We present a 5000-year environmental history of a radiocarbon dated sediment core from Esambu Swamp adjacent to Amboseli National Park. Although radiocarbon dates suggest an unconformity or sedimentary gap that spans between 3800 and 500 cal year BP, the record provides a unique insight into the long-term ecosystem history and wetland processes, particularly the past 500 years. Climatic shifts, fire activity and recent anthropogenic activity drive changes in ecosystem composition. Prior to 3800 cal year BP the pollen data suggest semi-arid savanna ecosystem persisted near the wetland. The wetland transgressed at some time between 3800 and 500 cal year BP and it is difficult to constrain this timing further, and palustrine peaty sediments have accumulated since 400 cal year BP. Increased abundance of Afromontane forest taxa from adjacent highlands of Kilimanjaro and the Chyulu Hills and local arboreal taxa reflect changes in regional moisture budgets. Particularly transformative changes occurred in the last five centuries, associated with increased local biomass burning coeval with the arrival of Maa-speaking pastoralists and intensification of the ivory trade. Cereal crops occurred consistently from around 300 cal year BP, indicative of further anthropogenic activity. The study provides unique insight in Amboseli ecosystem history and the link between ecosystem drivers of change. Such long-term perspectives are crucial for future climate change and associated livelihood impacts, so that suitable responses to ensure sustainable management practices can be developed in an important conservation landscape.  相似文献   
964.
965.
Households in hurricane-prone regions respond to hurricane threat in numerous ways. Perceptions about their risk and other factors are thought to influence individuals’ decisions to take protective actions for hurricanes. This research investigates the perceptions, behavioral intentions, and actual protective actions of a sample of residents in Miami-Dade County, Florida. We use unique data collected via a telephone survey to investigate a set of factors including risk perception, perceived local government readiness for a hurricane, past hurricane experience, hazard information exposure, and demographics, which have been posited to influence perceived hurricane preparedness, intent to evacuate under hurricane threat, and actual hurricane preparedness. The analytic results show that risk perception was positively associated with perceived preparedness, intent to evacuate, and one of the actual preparedness measures. Perceived local government readiness for a hurricane also was positively related to perceived preparedness and an actual protective measure. The results for other factors, including socio-demographics, varied by dependent variable. Following a report of the results, we discuss the research and policy implications of our findings.  相似文献   
966.
ABSTRACT

The electricity grid is susceptible to numerous threats, especially severe weather events that have the potential to cause large-scale power outages. This has resulted in an increased emphasis on resilience against these events. Microgrids, small standalone power grids that have the ability to function independently from the greater electricity grid, have significant potential to improve response to environmental and anthropogenic crises. The vast majority of extant microgrids are generally small in scale, and operated under a conventional model of single operator, owner, and user. We argue that the ultimate potential of this approach will be in the development of multi-stakeholder microgrids which can combine a diversity of renewable and conventional power resources to respond to environmental hazards. The addition of stakeholders allows for increased diversification of generation sources, economies of scale, and other increased operational benefits and opportunities. However, there are significant challenges that arise with the additional layer of stakeholders in terms of governance, cost, and technical operations that can cause the multi-stakeholder model to be more difficult to implement. We develop the case for multi-stakeholder microgrids as a response to environmental hazards, and outline the challenges and questions facing the development of this form of microgrid.  相似文献   
967.
As natural disasters increase around the world and stretch the capacities of emergency services, national governments and international institutions have stressed the importance of shared responsibility; the idea that all actors within a society have some obligations in disaster management and must work collectively to reduce disaster risk. However, the exact balance between individual and government responsibility is not yet established and continually contested, especially after major events. In Australia, the National Strategy for Disaster Resilience (NSDR) is the overarching policy framework for disaster risk management and aims to create resilient communities through an emphasis on shared responsibility and empowerment. Through a literature review and document analysis of the NSDR and associated policy documents, we clarify, organise and operationalise the necessarily general policy goal of shared responsibility. We first analyse how the NSDR conceptualises communities to discover which community actors are mentioned. We then identify the responsibilities it prescribes or implies for these different actors and consider the types of policy instruments that are relevant to disaster risk management. Our analysis reveals a tension between the NSDR’s placement of government at the centre of disaster risk management, and its other, less well-explained emphasis on community empowerment.  相似文献   
968.
Timothy Hsiao attempts to defend industrial animal farming by arguing that it is not inherently cruel. We raise three main objections to his defense. First, his argument rests on a misunderstanding of the nature of cruelty. Second, his conclusion, though technically true, is so weak as to be of virtually no moral significance or interest. Third, his contention that animals lack moral standing, and thus that mistreating them is wrong only insofar as it makes one more disposed to mistreat other humans, is untenable on both philosophical and biological grounds.  相似文献   
969.
Climate-induced changes in vegetation phenology at northern latitudes are still poorly understood. Continued monitoring and research are therefore needed to improve the understanding of abiotic drivers. Here we used 14 years of time lapse imagery and climate data from high-Arctic Northeast Greenland to assess the seasonal response of a dwarf shrub heath, grassland, and fen, to inter-annual variation in snow-cover, soil moisture, and air and soil temperatures. A late snow melt and start of growing season is counterbalanced by a fast greenup and a tendency to higher peak greenness values. Snow water equivalents and soil moisture explained up to 77 % of growing season duration and senescence phase, highlighting that water availability is a prominent driver in the heath site, rather than temperatures. We found a significant advance in the start of spring by 10 days and in the end of fall by 11 days, resulting in an unchanged growing season length. Vegetation greenness, derived from the imagery, was correlated to primary productivity, showing that the imagery holds valuable information on vegetation productivity.  相似文献   
970.
Watershed‐scale hydrologic simulation models generally require climate data inputs including precipitation and temperature. These climate inputs can be derived from downscaled global climate simulations which have the potential to drive runoff forecasts at the scale of local watersheds. While a simulation designed to drive a local watershed model would ideally be constructed at an appropriate scale, global climate simulations are, by definition, arbitrarily determined large rectangular spatial grids. This paper addresses the technical challenge of making climate simulation model results readily available in the form of downscaled datasets that can be used for watershed scale models. Specifically, we present the development and deployment of a new Coupled Model Intercomparison Project phase 5 (CMIP5) based database which has been prepared through a scaling and weighted averaging process for use at the level of U.S. Geological Survey (USGS) Hydrologic Unit Code (HUC)‐8 watersheds. The resulting dataset includes 2,106 virtual observation sites (watershed centroids) each with 698 associated time series datasets representing average monthly temperature and precipitation between 1950 and 2099 based on 234 unique climate model simulations. The new dataset is deployed on a HydroServer and distributed using WaterOneFlow web services in the WaterML format. These methods can be adapted for downscaled General Circulation Model (GCM) results for specific drainage areas smaller than HUC‐8. Two example use cases for the dataset also are presented.  相似文献   
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