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Central Asia’s Ili River Ecosystem as a Wicked Problem: Unraveling Complex Interrelationships at the Interface of Water, Energy, and Food Полный текст
2018
Steven G. Pueppke | Sabir T. Nurtazin | Norman A. Graham | Jiaguo Qi
The Ili River originates in the mountains of Xinjiang, China, and flows across an increasingly arid landscape before terminating in Kazakhstan’s Lake Balkhash, which has no outlet to the ocean. The river has been extensively impounded and diverted over the past half century to produce hydroelectric power and food on irrigated land. Water withdrawals are increasing to the extent that they are beginning to threaten the ecosystem, just as it is becoming stressed by altered inflows as glaciers retreat and disappear. If the Ili River ecosystem is to be preserved, it is crucial that we thoroughly understand the spatial and temporal nuances of the interrelationships between water, energy, and food—and the vulnerability of these components to climate change. The ecosystem has all of the characteristics of a classically-defined “wicked problem”, and so it warrants treatment as a complex and dynamic challenge subject to changing assumptions, unexpected consequences, and strong social and economic overtones. Research should thus focus not just on new knowledge about the water, energy, or food component, but on advancing our understanding of the ecosystem as a whole. This will require the participation of interdisciplinary teams of researchers with both tacit and specialized knowledge.
Показать больше [+] Меньше [-]Host Age Affects the Development of Southern Catfish Gut Bacterial Community Divergent From That in the Food and Rearing Water Полный текст
2018
Zhimin Zhang | Zhimin Zhang | Dapeng Li | Dapeng Li | Mohamed M. Refaey | Mohamed M. Refaey | Mohamed M. Refaey | Weitong Xu | Weitong Xu | Rong Tang | Rong Tang | Li Li | Li Li
Host development influences gut microbial assemblies that may be confounded partly by dietary shifts and the changing environmental microbiota during ontogenesis. However, little is known about microbial colonization by excluding dietary effects and compositional differences in microbiota between the gut and environment at different ontogenetic stages. Herein, a developmental gut microbial experiment under controlled laboratory conditions was conducted with carnivorous southern catfish Silurus meridionalis fed on an identical prey with commensal and abundant microbiota. In this study, we provided a long-term analysis of gut microbiota associated with host age at 8, 18, 35, 65, and 125 day post-fertilization (dpf) and explored microbial relationships among host, food and water environment at 8, 35, and 125 dpf. The results showed that gut microbial diversity in southern catfish tended to increase linearly as host aged. Gut microbiota underwent significant temporal shifts despite similar microbial communities in food and rearing water during the host development and dramatically differed from the environmental microbiota. At the compositional abundance, Tenericutes and Fusobacteria were enriched in the gut and markedly varied with host age, whereas Spirochaetes and Bacteroidetes detected were persistently the most abundant phyla in food and water, respectively. In addition to alterations in individual microbial taxa, the individual differences in gut microbiota were at a lower level at the early stages than at the late stages and in which gut microbiota reached a stable status, suggesting the course of microbial successions. These results indicate that host development fundamentally shapes a key transition in microbial community structure, which is independent of dietary effects. In addition, the dominant taxa residing in the gut do not share their niche habitats with the abundant microbiota in the surrounding environment. It's inferred that complex gut microbiota could not be simple reflections of environmental microbiota. The knowledge enhances the understanding of gut microbial establishment in the developing fish and provides a useful resource for such studies of fish- or egg-associated microbiota in aquaculture.
Показать больше [+] Меньше [-]The Water-Energy-Food Nexus in East Asia: A tele-connected value chain analysis using inter-regional input-output analysis Полный текст
2018
White, David J. | Hubacek, Klaus | Feng, Kuishuang | Sun, Laixiang | Meng, Bo
Population and economic growth pose unique challenges in securing sufficient water, energy, and food to meet demand at the sub-national (regional), national, and supra-national level. An increasing share of this demand is met through trade and imports. The unprecedented rapid growth, extent, and complexity of global value chains (GVCs) since the 1980s have reshaped global trade. The GVCs – and new economic patterns of regionalization – affect the demands on water, energy, and food within countries and across global supply chains. East Asia is of particular interest due to the region’s rapid economic growth, substantial population size, high interdependence of the region’s economies, and varying degree of resource availability. While greater interdependence across the region has increased the efficiency of production and trade, these activities require the input of water-energy-food and generate disturbances in the environment. The transnational inter-regional input-output approach is utilized in a tele-connected Water-Energy-Food Nexus (WEFN) analysis of the East Asia GVC to assess competing demands for these resources and environmental outcomes.This analysis demonstrates the hidden virtual flows of water, energy, and food embodied in intra-regional and transnational inter-regional trade. China’s current national export oriented economic growth strategy in East Asia is not sustainable from the WEFN perspective. China is a net virtual exporter of nexus resources to Japan and South Korea. China’s prioritization of economic growth and trade in low value added and pollution intensive sectors consumes a great amount of nexus resources within its territory to satisfy consumers’ demands in Japan and South Korea. Japan’s Kanto and Kinki regions and South Korea’s Sudokwon region were the major beneficiaries while China bore the environmental burden associated with the production of exports. For example, net virtual exports from China’s East region included over 1.2billionm³ of scarce water and 61.3million metric (CO₂ equivalent) tons of greenhouse gases (i.e. CO₂, NH₄, and N₂O) and 2 million metric tons of SOₓ emissions.Trade is an important mechanism for overcoming resource bottlenecks, but, taking into account environmental linkages, regional specialization is not necessarily mutually beneficial. This analysis demonstrates a mismatch between regional water-energy-food availability and final resource consumption and the lack of attention for environmental impacts in national economic growth strategies. Resource scarce countries like China must, therefore, incorporate trade-off decisions between pursuing national economic growth, incurring environmental degradation, and food security into strategic regional development policies.
Показать больше [+] Меньше [-]Fecal Indicator Bacteria along Multiple Environmental Transmission Pathways (Water, Hands, Food, Soil, Flies) and Subsequent Child Diarrhea in Rural Bangladesh Полный текст
2018
Pickering, Amy J. | Ercumen, Ayse | Arnold, Benjamin F. | Kwong, Laura H. | Parvez, Sarker Masud | Alam, Mahfuja | Sen, Debashis | Islam, Sharmin | Kullmann, Craig | Chase, Claire | Ahmed, Rokeya | Unicomb, Leanne | Colford, John M. | Luby, Stephen P.
Enteric pathogens can be transmitted through multiple environmental pathways, yet little is known about the relative contribution of each pathway to diarrhea risk among children. We aimed to identify fecal transmission pathways in the household environment associated with prospectively measured child diarrhea in rural Bangladesh. We measured the presence and levels of Escherichia coli in tube wells, stored drinking water, pond water, child hand rinses, courtyard soil, flies, and food in 1843 households. Gastrointestinal symptoms among children ages 0–60 months were recorded concurrently at the time of environmental sample collection and again a median of 6 days later. Incident diarrhea (3 or more loose stools in a 24-h period) was positively associated with the concentration of E. coli on child hands measured on the first visit (incidence rate ratio [IRR] = 1.23, 95% CI 1.06, 1.43 for a log₁₀ increase), while other pathways were not associated. In cross-sectional analysis, there were no associations between concurrently measured environmental contamination and diarrhea. Our findings suggest higher levels of E. coli on child hands are strongly associated with subsequent diarrheal illness rates among children in rural Bangladesh.
Показать больше [+] Меньше [-]The potential impact of Brexit on the energy, water and food nexus in the UK: A fuzzy cognitive mapping approach Полный текст
2018
Ziv, Guy | Watson, Elizabeth | Young, Dylan | Howard, David C. | Larcom, Shaun T. | Tanentzap, Andrew J.
Energy is one of the cornerstones essential for human life, along with other services such as water and food. Understanding how the different services in the energy-water-food (EWF) nexus interact and are perceived by different actors is key to achieving sustainability. In this paper, we derive a model of the EWF nexus using fuzzy cognitive mapping (FCM). Data were collected in a two-step approach from workshops with researchers and stakeholders involved in the three focal sectors. Four FCMs were developed; one for each of the EWF sectors, and one for the interactions that create the nexus between EWF. The FCM represents the combined views of the groups who participated in the workshops, the importance and limitations of which is discussed. To demonstrate its effectiveness, the aggregated FCM was applied to predict the impacts on the EWF nexus of four scenarios under which the United Kingdom would depart from the European Union (i.e. Brexit). The FCM indicated that energy-related concepts had the largest influence on the EWF nexus and that EWF demand will decrease most under a ‘hard-Brexit’ scenario. The demand for energy was shown to decline relatively less than other services and was strongly associated with gross domestic product (GDP), whereas UK population size had a stronger effect on water and food demand. Overall, we found a threefold change across all concepts in scenarios without freedom of movement, contribution to the EU budget, and increased policy devolution to the UK.
Показать больше [+] Меньше [-]Evaluating sustainability of water-energy-food (WEF) nexus using an improved matter-element extension model: A case study of China Полный текст
2018
Wang, Qiang | Li, Siqi | He, Gang | Li, Rongrong | Wang, Xuefeng
The sustainability of the water-energy-food (WEF) nexus is a significant challenge faced by developing countries, especially China. Evaluating the sustainability status of China's water-energy-food, and improving its sustainable use, may provide good physical conditions to support China's future development. This paper applied the Pressure, State, and Response (PSR) model to select evaluation indexes. A combination weighting method was used to combine two objective weighting methods to determine index weights. The study constructed the classical field, the limited field, and the matter-element to be evaluated. This allowed the establishment of an improved matter-element extension model to evaluate the sustainability of the water-energy-food nexus; the model was then used to quantitatively evaluate the sustainability of China's water-energy-food nexus. The simulation results indicated that in 2005, the sustainability of China's water-energy-food was at a relatively low efficiency rank. By 2015, the sustainability of China's water-energy-food had reached a general efficiency rank. The results suggested that the sustainability of China's water-energy-food system significantly improved between 2005 and 2015; however, the improved sustainability remained at a general status (The general status means that the sustainability of water-energy-food nexus in China can meet the basic development needs, but it is far from the optimal state and needs further adjustment and improvement). Thus, China should improve its current utilization patterns for the three resources and consider them as a whole. This would help realize synergistic resource use and enhance their sustainability.
Показать больше [+] Меньше [-]Cellulose-glycerol-polyvinyl alcohol composite films for food packaging: Evaluation of water adsorption, mechanical properties, light-barrier properties and transparency Полный текст
2018
Cazón, Patricia | Vázquez Murillo, Manuel | Velázquez, Gonzalo
Nowadays consumers are aware of environmental problems. As an alternative to petrochemical polymers for food packaging, researchers have been focused on biopolymeric materials as raw material. The aim of this study was to evaluate mechanical properties (toughness, burst strength and distance to burst), water adsorption, light-barrier properties and transparency of composite films based on cellulose, glycerol and polyvinyl alcohol. Scanning electron microscopy, spectral analysis (FT-IR and UV–VIS-NIR) and differential scanning calorimetry were performed to explain the morphology, structural and thermal properties of the films. Results showed that polyvinyl alcohol enhances the toughness of films up to 44.30 MJ/m3. However, toughness decreases when glycerol concentration is increased (from 23.41 to 10.55 MJ/m3). Water adsorption increased with increasing polyvinyl alcohol concentration up to 222%. Polyvinyl alcohol increased the film thickness. The films showed higher burst strength (up to 12014 g) than other biodegradable films. The films obtained have optimal values of transparency like those values of synthetic polymers. Glycerol produced a UV protective effect in the films, an important effect for food packaging to prevent lipid oxidative deterioration. Results showed that it is feasible to obtain cellulose-glycerol-polyvinyl alcohol composite films with improved properties.
Показать больше [+] Меньше [-]Predicting the combinatorial effects of water activity, pH and organic acids on Listeria growth in media and complex food matrices Полный текст
2018
Nyhan, L. | Begley, M. | Mutel, A. | Qu, Y. | Johnson, N. | Callanan, M.
The aim of this study was to develop a model to predict growth of Listeria in complex food matrices as a function of pH, water activity and undissociated acetic and propionic acid concentration i.e. common food hurdles. Experimental growth curves of Listeria in food products and broth media were collected from ComBase, the literature and industry sources from which a bespoke secondary gamma model was constructed. Model performance was evaluated by comparing predictions to measured growth rates in growth media (BHI broth) and two adjusted food matrices (zucchini purée and béarnaise sauce). In general, observed growth rates were higher in broth than in the food matrices which resulted in the model over-estimating growth in the adjusted food matrices. In addition, model outputs were more accurate for conditions without acids, indicating that the organic acid component of the model was a source of inaccuracy. In summary, a new predictive growth model for innovating or renovating food products that rely on multi-hurdle technology was created. This study is the first to report on modelling of propionic acid as an inhibitor of Listeria in combination with other hurdles. Our findings provide valuable insights into predictive model design and performance and highlight the importance of experimental validation of models in real food matrices rather than laboratory media alone.
Показать больше [+] Меньше [-]Assessment of the Impacts of Rice Self-sufficiency on National Rresources in Korea through Water-Energy-Food-Land Nexus Approach
2018
Lee, S.H., Texas A and M University, USA | Choi, J.Y., Seoul National University, Seoul, Republic of Korea | Yoo, S.H., Chonnam National University, Gwangju, Republic of Korea | Hur, S.O., National Institute of Agricultural Sciences, Rural Development Administration, Wanju, Republic of Korea
The aim of this study is to apply the Water-Energy-Food-Land Nexus approach which can analyze the trade-offs among resources, and assess the holistic impacts of food security. First, we applied rice as a study crop and analyzed the trend of consumption of rice and the area of paddy fields. Second, the portfolios of water, energy, and land for rice production were constructed using data of footprints and productivity. Finally, the self-sufficiency ratio (SSR) of rice in target year was set as food security scenario and assessed the impacts of food security on water, energy, and land availability. In 2030, the SSR of rice decreased to 87 %, and water use for producing rice decreased from 4,728 to 3,350 million m³, and the water availability index increased from 0.33 to 0.53. However, food security is essential issue and we set the 50 % and 100 % SSR of rice as high and low food security scenarios. For 100% SSR in 2030, about 3,508 million m³ water was required and water availability index reached to 0.5. In other words, there is the trade-off between food security and water-energy-lands availability. Therefore, it is difficult to make a decision whether a high level of SSR is better or worse. However, this study showed the both positive and negative impacts by change of food security and it can be useful for setting the policy decision considering both food security and sustainable resource management at the same time.
Показать больше [+] Меньше [-]Central Asia’s Ili River Ecosystem as a Wicked Problem: Unraveling Complex Interrelationships at the Interface of Water, Energy, and Food Полный текст
2018
Pueppke, Steven G. | Nurtazin, Sabir T. | Graham, Norman A. | Qi, Jiaguo
The Ili River originates in the mountains of Xinjiang, China, and flows across an increasingly arid landscape before terminating in Kazakhstan’s Lake Balkhash, which has no outlet to the ocean. The river has been extensively impounded and diverted over the past half century to produce hydroelectric power and food on irrigated land. Water withdrawals are increasing to the extent that they are beginning to threaten the ecosystem, just as it is becoming stressed by altered inflows as glaciers retreat and disappear. If the Ili River ecosystem is to be preserved, it is crucial that we thoroughly understand the spatial and temporal nuances of the interrelationships between water, energy, and food—and the vulnerability of these components to climate change. The ecosystem has all of the characteristics of a classically-defined “wicked problem”, and so it warrants treatment as a complex and dynamic challenge subject to changing assumptions, unexpected consequences, and strong social and economic overtones. Research should thus focus not just on new knowledge about the water, energy, or food component, but on advancing our understanding of the ecosystem as a whole. This will require the participation of interdisciplinary teams of researchers with both tacit and specialized knowledge.
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