خيارات البحث
النتائج 91 - 100 من 224
The Impact of Pricing Policies on Irrigation Water for Agro-Food Farms in Ecuador النص الكامل
2017
Franco-Crespo, Christian | Sumpsi, José María
The institutional reform of the State established in Ecuador during the last decade has aimed at regaining control of specific sectors such as the consumptive use of water. Since 2014, regulation, consumption, and use of water, especially in agriculture, have been analyzed through policies and fiscal instruments. This research presents itself in the context of the simulation of scenarios using positive mathematical programming, to analyze the economic impact of pricing policies on agro-food farms. Policies of fixed costs, water blocks, and volumetric prices are evaluated. The results show that the existing fixed costs do not reduce water consumption. In contrast, the scenarios of water blocks and volumetric prices impact on the behavior of farmers. The tendency of water consumption to the application of volumetric prices demonstrates that banana farms have a greater tolerance to the increase of water costs. On the other hand, the response to an increase in cost in the case of cacao, sugar cane, and rice depends on the productivity of farmers. The negative effects can lead to the abandonment of agriculture. Thus, volumetric policies are more efficient in reducing water consumption as well as in recovering the costs of the irrigation system.
اظهر المزيد [+] اقل [-]Closing the governance gaps in the water-energy-food nexus: Insights from integrative governance النص الكامل
2017
Weitz, Nina | Strambo, Claudia | Kemp-Benedict, Eric | Måns Nilsson på Aspeboda,
The water-energy-food nexus has become a popular concept in environmental change research and policy debates. Proponents suggest that a nexus approach promotes policy coherence through identifying optimal policy mixes and governance arrangements across the water, energy and food sectors. Although the nexus literature identifies some barriers to achieving coherence it does not clearly explain why the barriers are present, what influences them, and how they can be acted upon. These gaps disconnect the nexus literature from the governance processes it ultimately seeks to influence. This paper examines how the integrative environmental governance literature can help to close these gaps. It extracts insights from seven streams of research literature and discusses their relevance for the nexus literature. We argue that connecting the nexus to decision-making processes requires: i) rethinking the boundaries of nexus analysis vis-à-vis other sectors and levels; ii) elaboration of shared principles that can guide decision-making towards policy coherence − or an appropriate form of fragmentation − in different contexts; iii) viewing policy coherence as a continuous process of changing values and perception rather than as an outcome.
اظهر المزيد [+] اقل [-]Analysis on the Water-saving Irrigation Technique Based on the Perspective of Food Safety النص الكامل
2017
HUANG, Jinpeng | WANG, Benfu | ZHOU, Bende
The paper analyzed the important role of water saving in protecting the food safety, introduced the present development of agricultural water-saving technique, pointed out the potential risks of water resources, and proposed the future development of water-saving irrigation.
اظهر المزيد [+] اقل [-]Registered Dietitian Nutritionists’ Perspectives on Integrating Food and Water System Issues into Professional Practice النص الكامل
2017
Heidelberger, Lindsay | Smith, Chery | Robinson-O’Brien, Ramona | Earthman, Carrie | Robien, Kim
Sustainable agriculture encompasses economic, environmental, and social aspects of the food system. Members of the Academy of Nutrition and Dietetics (Academy) play an important role in promoting sustainable agriculture because they work in areas where they can influence the food purchasing decisions of foodservice operations and the public.To investigate behavior of registered dietitian nutritionists (RDNs) toward incorporating sustainable agriculture principles into professional practice using the Theory of Planned Behavior.This cross-sectional study surveyed RDNs nationwide about their perspectives on incorporating sustainable agriculture issues into practice. The survey questions were based on a survey originally administered to Minnesota RDNs during 2002.The sample (N=626) was drawn from a randomly selected, national sample of Academy members.Data were analyzed using descriptive statistics, independent t tests, Pearson correlations, and stepwise regression.The sample was mostly white, female, and the average age was 45.4±12.2 years. Almost half of Academy RDNs (47%) reported incorporating environmental issues into their practice. All four Theory of Planned Behavior variables (intention, attitude, perceived behavior control, and subjective norm) were predictive of behavior to include sustainable agriculture issues into practice. Barriers to incorporating this topic into practice included lack of knowledge, ability, time, and employer support.This study found that most of the RDN respondents had heard of sustainable agriculture and nearly half reported including this topic in their professional practice. To integrate this topic into practice more consistently, RDNs need more knowledge, time, and employer support.
اظهر المزيد [+] اقل [-]Ultrasonic degradation kinetics and rheological profiles of a food polysaccharide (konjac glucomannan) in water النص الكامل
2017
Li, Jing | Li, Bin | Geng, Ping | Song, Ang-Xin | Wu, Jian-Yong
This study was carried out to evaluate the effects of power ultrasound (US) on the molecular weight and rheological properties of a food polysaccharide, konjac glucomannan (KGM). Upon the exposure of KGM solution (1% w/v in water) to US at a relatively high power intensity (50 W/cm2), the apparent viscosity decreased rapidly from about 50 Pa s to a negligible level within 10–20 min. The intrinsic viscosity ([η]) of KGM solution decreased gradually during the US exposure with a time course closely fitted to the first-order polymer degradation kinetics (random chain scission). The US treatment also caused a significant reduction of particle size (Zavg) of KGM aggregates and changes in the rheological properties including the decrease of storage modulus (G′) and loss modulus (G″), and the increase in phase angle (tan δ = G″/G′). Nevertheless, no change in primary structure was detected by Fourier transformation infrared (FT-IR) analysis. The results suggested that high intensity US was an effective means for KGM degradation without significant structural destruction.
اظهر المزيد [+] اقل [-]Daphnia magna fitness during low food supply under different water temperature and brownification scenarios. النص الكامل
2017
Gall, Andrea | Kainz, Martin J. | Rasconi, Serena | Centre Alpin de Recherche sur les Réseaux Trophiques et Ecosystèmes Limniques (CARRTEL) ; Institut National de la Recherche Agronomique (INRA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])
International audience
اظهر المزيد [+] اقل [-]Water for Energy and Food: A System Modelling Approach for Blue Nile River Basin النص الكامل
2017
Cho Tan | Tohid Erfani | Rasool Erfani
The world is facing a more water constrained future as a result of urbanisation, population growth, industrialisation and the emergence of climate change. This has direct impacts on the resilience and performance of the energy and food industries, as water plays a key role in electricity generation processes and agriculture production. Water, energy and food dependencies are more evident in transboundary river basins where several countries share the same source of water for irrigation demand and energy production. From the perspective of the upstream users, it would be ideal to store the water for hydropower generation and the agriculture sector while protecting the environment, whereas the downstream users need the supply of water for their agricultural growth and municipal requirements. We aim to develop a system thinking study by focusing on the transboundary Blue Nile River basin where the Ethiopian government investment in the Grand Renaissance dam has led to opposition by downstream users due to potential reduction of water resource availability downstream. We propose a system thinking approach for analysing different water management practices that considers all the available resources and the requirements set by all the users. To simulate this interaction, we use system dynamics to model the linkage between food production, water abstraction and energy generation. We link the simulation model to an optimisation engine to achieve effective management of the reservoir’s operation. The study provides a platform to investigate how the reservoir operating policies can improve an understanding of the value of water in its alternative uses, and shows how different optimal reservoir release rules generate different optimal solutions inherently involved in upstream and downstream users’ requirements. The proposed methodology is an attempt to enable Nile riparian countries to make more informed decisions on water resources policy and management.
اظهر المزيد [+] اقل [-]Influence of protein type on Polyglycerol Polyricinoleate replacement in W/O/W (water-in-oil-in-water) double emulsions for food applications النص الكامل
2017
Balcaen, Mathieu | Vermeir, Lien | Van der Meeren, Paul
In most publications concerning edible W/O/W-emulsions, the low-HLB emulsifier polyglycerol polyricinoleate (PGPR) is used to stabilize the W/O-interface in combination with a high-HLB emulsifier which stabilizes the O/W-interface. Therefore, PGPR was used as the reference low-HLB emulsifier and compared to two alternative low-HLB emulsifiers namely ammonium phosphatide (AMP) and low-HLB sucrose ester O-170. As high-HLB emulsifiers both random coil (sodium caseinate) and globular proteins (whey protein isolate) were used. Hereby, the use of WPI led to similar, high enclosed water volume fractions for all used low-HLB emulsifiers whereas the use of Na-Caseinate led to almost no enclosed water in the emulsions containing ammonium phosphatide. Finally, the influence of osmotic pressure gradients on the release of an enclosed compound was examined. Therefore, the W/O/W-emulsions were diluted in iso-, hypo- and hypertonic solutions after which the release of an enclosed marker compound was followed over time. Hereby, AMP- and O-170 stabilized W/O/W-emulsions released the enclosed marker due to swelling under hypotonic dilution whereas hyper- and isotonic dilution never led to release of the enclosed marker, regardless of the used low-HLB emulsifier.
اظهر المزيد [+] اقل [-]Realistic pesticide exposure through water and food amplifies long-term effects in a Limnephilid caddisfly النص الكامل
2017
Rasmussen, Jes Jessen | Reiber, Lena | Holmstrup, Martin | Liess, Matthias
Pesticides are increasingly recognized as relevant stressors in stream ecosystems. Stream biota is exposed to pesticides with low water solubility, e.g. pyrethroid insecticides, via water, habitat, and food. However, long-term effects of simultaneous exposure pathways are unknown. In this context, we conducted a microcosm experiment with the caddisfly Anabolia nervosa exposing the larvae to the pyrethroid insecticide esfenvalerate (EFV) at 0.1 and 1.0μgL−1 via (i) water, (ii) food or a (iii) combination of water and food. Combined exposure through water and food significantly reduced emergence by 60% and significantly postponed emergence timing at the highest EFV level, whereas none of the single-phase exposures showed significant effects. Moreover, our study revealed that successfully emerged females from the highest biphasic treatment level were characterised by altered composition of storage lipids indicative of reduced energy reserves. Consequently, a realistic test scenario that represents simultaneous exposure of organisms and their food may reveal substantially increased long term effects of pyrethroids when compared with current ecological risk assessment applying only single phase exposure. We recommend that relevant concurrent exposure routes of pesticides should be considered in order to derive realistic regulatory acceptable concentrations of pesticides.
اظهر المزيد [+] اقل [-]Veterinary antibiotics in food, drinking water, and the urine of preschool children in Hong Kong النص الكامل
2017
Li, Na | Ho, Keith W.K. | Ying, Guang-Guo | Deng, Wen-Jing
Due to the harmful effects of veterinary antibiotics (VAs) residues in food on children's health, urine samples from 31 preschool and primary school children were analyzed for 13 common VAs. Samples of raw and cooked pork, chicken, fish, milk and drinking water from the children's living areas were also analyzed for residual VAs. Urinalysis revealed one to four target antibiotics in 77.4% of the sample group, with concentrations as high as 0.36ng/mL. Norfloxacin and penicillin had the highest detection rates (48.4% and 35.5%, respectively), with median concentrations of 0.037 and 0.13ng/mL, respectively. The VA burden of children in HK was lower than that in Shanghai. Enrofloxacin, penicillin, and erythromycin were the most detected VAs in raw and cooked food. Only oxytetracycline was detected in terminal tap water, and none were detected in milk. Tetracycline and doxycycline hyclate were detected in organic eggs (up to 7.1ng/g) and regular eggs (up to 6.6ng/g), which were common in children's diets. Traditional Chinese cooking processes did not completely eliminate VAs, and the concentrations of some VAs increased, especially after frying and roasting. The estimated daily intake (EDI) results show that the contribution of dietary intake and that based on the urine concentrations of VAs were far below the acceptable daily intake (ADI). The EDIs from urine were significantly lower than those based on cooked foods. The highest level of achievement percentage (LAP) based on dietary consumption and urine concentrations were 39.7% and 1.79%, respectively, and thus current levels of exposure to VAs would not seem to pose a risk to children's health. However, harmful effects of residual VAs during developmental periods may occur with exposure to much lower doses than those considered harmful to adults, and further investigation of these emerging pollutants is urgently encouraged.
اظهر المزيد [+] اقل [-]