Antioxidant Activity of Osage Orange Extract in Soybean Oil and Fish Oil during Storage

The food industry is seeking natural antioxidants for edible oils that have comparable activity to synthetic counterparts. In this study, Osage orange extract (OOE) rich in osajin (42.9%) and pomiferin (30.0%) was obtained after hexane extraction of the fruit, and its antioxidant activity was examined in stripped soybean oil (SBO) and fish oil (FO), in which antioxidants and polar compounds were removed. The antioxidant activity of OOE was compared with commercial natural antioxidants (i.e., rosemary extract and mixed tocopherols) and a synthetic antioxidant, butylated hydroxytoluene (BHT), during storage at 25 and 40 °C. The 0.1% OOE had stronger antioxidant activity than 0.1% rosemary extract and 0.1% mixed tocopherols in both oils at 25 and 40 °C. Its activity was similar to 0.02% BHT in SBO and was similar or slightly stronger than 0.02% BHT in FO. When OOE was studied at 0.05, 0.1, and 0.2%, there was a weak dose–response in SBO but a stronger dose–response in FO. Headspace volatile analysis using solid phase micro-extraction (SPME) combined with GC–MS indicated that 0.1% OOE was very effective in preventing the formation of volatile oxidation products in both oils. Although it should be further tested for safety before the actual use, this study shows that OOE can be developed as an antioxidant for edible oils.     

Early observations on an emerging Great Lakes invader Hemimysis anomala in Lake Ontario

Hemimysis anomala, a Ponto-Caspian littoral mysid, is an emerging Great Lakes invader that was discovered in Lakes Michigan and Ontario in 2006. Similar to the native mysid Mysis diluviana, Hemimysis exhibits a diel vertical migration pattern but generally inhabits shallower and warmer waters than M. diluviana. Because basic information on the distribution, habitat use, and biology of Hemimysis in the Great Lakes is scarce, the potential for food web disruption by Hemimysis cannot easily be predicted. Preliminary observations indicate widespread invasion of Hemimysis in Lake Ontario. In this study, we confirm the presence of Hemimysis at sites spanning the northern and southern shores of Lake Ontario and the presence of the individuals during winter months. In one horizontal tow in November 2007, over 26,000 individuals were collected with a length range of 4.4 to 9.0 mm and an average caloric density of 611 cal/g wet weight. The most effective methods for sampling Hemimysis were horizontal tows with either a zooplankton net in the water column or a benthic sled near the lake bottom. Although more quantitative data on the life history and distribution of this species is necessary, our preliminary observations support the prediction that the potential for Hemimysis to impact the nearshore food web in Lake Ontario appears high.     

Use of flow-normalization to evaluate nutrient concentration and flux changes in Lake Champlain tributaries, 1990–2009

The U.S. Geological Survey evaluated 20 years of total phosphorus (P) and total nitrogen (N) concentration data for 18 Lake Champlain tributaries using a new statistical method based on weighted regressions to estimate daily concentration and flux histories based on discharge, season, and trend as explanatory variables. The use of all the streamflow discharge values for a given date in the record, in a process called “flow-normalization”, removed the year-to-year variation due to streamflow and generated a smooth time series from which trends were calculated. This approach to data analysis can be of great value to evaluations of the success of restoration efforts because it filters out the large random fluctuations in the flux that are due to the temporal variability in streamflow. Results for the full 20 years of record showed a mixture of upward and downward trends for concentrations and yields of P and N. When the record was broken into two 10-year periods, for many tributaries, the more recent period showed a reversal in N from upward to downward trends and a similar reversal or reduction in magnitude of upward trends for P. Some measures of P and N concentrations and yields appear to be related to intensity of agricultural activities, point-source loads of P, or population density. Total flow-normalized P flux aggregated from the monitored tributaries showed a decrease of 30 metric tons per year from 1991 to 2009, which is about 15% of the targeted reduction established by the operational management plan for the Lake Champlain Basin.     

Optimising Reliability: Portfolio Modeling of Contract Types for Retail Water Providers

This paper considers the retail water provider’s purchasing decision of a portfolio of permanent contracts from wholesalers with multiple volatile water sources. We consider the reliability of two contract types: (1) fixed annual quantities, and (2) an inflow harvest function with storage. Our four-reservoir case in Sydney (Australia) has cross-correlated inflow data. To accommodate multi-reservoir cross-correlation we adapt Portfolio Theory from finance to lognormal reservoir inflows, re-framing traditional storage theory from the wholesaler’s optimal operating policy to the retailer’s optimal purchasing policy. We find that Reliability improves with access to a source pool (cf. fixed quantities from separate sources), demonstrating the ‘insurance effect’, and the portfolio that minimises lognormal variance also minimises harvest (and thus environmental impact). Reform direction in Australian (and other international) water markets is towards multi-provider vertical disintegration, which may reduce pool opportunities and negate the insurance effect. We consider diminishing reliability returns as reservoir harvesting increases, and conclude a retail portfolio of permanent contracts from reservoirs, plus short-term contracts from alternative sources (either independently or negatively cross-correlated) efficiently secures high reliability. The challenge in incomplete water markets remains in encouraging and sustaining supply diversification that may only be needed aperiodically during extreme droughts.     

The Challenges of Inclusive Cross-Scale Collective Action in Watersheds

Abstract

Increasing attention to watershed management is part of an international policy trend toward integrated water resource management. Integration is multidimensional—across sectors, administrative regions, ministerial portfolios and levels of hydrologic structure and socioeconomic organization. Collective action is key. Individuals need to work effectively together to share common water points; upstream land users and downstream water consumers need to manage and resolve potential conflicts over water quantity and quality, while all the industries, farming communities, urban residents and public agencies that have interests in resource use and environmental quality need to agree on development and conservation objectives and approaches at the basin level. Initiatives that seek to foster collective action in watersheds need to account for the very different interests in water and watershed management. While there may be relatively straightforward ways to foster collective action at a local scale, some forms of collective action may, in fact, be detrimental to other stakeholders. In the developing world in particular, there are often geographic pockets and social groups that are chronically disadvantaged in collective and public processes. Water-users' associations and basin authorities may exacerbate these disparities and further marginalize already poor people. New statutory institutions may intentionally or inadvertently disempower effective customary local institutions. To enable project and program designers to address these challenges better, this paper lays out a framework for assessing the potential for, and implications of, individual and collective decisions in a watershed context. The framework integrates concepts drawn from the biophysical and social sciences, including new perspectives on watershed components, poverty, and collective action. Collective action is seen as a fractal process: collective action for water management at one level of social-spatial organization can have spillover effects at lower and higher levels of social-spatial resolution. To be pro-poor, watershed-management institutions must be genuinely inclusive, deliberately recognizing the interests, perspectives and knowledge of groups that may be systematically excluded from other political and social processes. Researchers, evaluators, watershed-management practitioners and others who apply the framework should be better placed to lay the foundations for that illusive goal: pro-poor, inclusive and resource-conserving development.     

Assessment of remnant unionid assemblages in a selection of Great Lakes coastal wetlands

Populations of native unionids have been in steady decline over the past century. The invasion of dreissenid mussels (Dreissena polymorpha and Dreissena rostriformis bugensis) in the mid-1980's impacted already imperiled unionid populations by greatly increasing their regional extinction rates. A selection of Great Lakes coastal wetlands around Michigan was surveyed to locate remnant populations of native unionids. Physical and chemical parameters were measured in coastal wetlands to evaluate the importance of these habitat parameters to remnant unionid assemblages. We assessed fouling rates by dreissenids on unionids and used artificial substrates to estimate dreissenid colonization densities. Live unionids were found in coastal wetlands of the Les Cheneaux Islands, the Lake St. Clair delta, and North Maumee Bay with significantly higher unionid fouling in the Les Cheneaux Islands compared to the other two sampling areas (F_2,76 = 4.97, p = 0.0095). No live unionids were documented in Beaver Island, Garden Island, Grand Traverse Bay, or Saginaw Bay wetlands. Dreissena colonization densities on artificial substrates averaged 19,213 m^− 2 at one site in North Maumee Bay, and 10,425 m^− 2 in Saginaw Bay, but no colonization occurred in the wetlands of Beaver Island, Garden Island, the Les Cheneaux Islands, or Grand Traverse Bay while Dreissena presence in the open water of these regions was evident. Dreissena colonization densities on artificial substrates increased with measures of anthropogenic disturbance and decreased with higher water level fluctuations and aerial exposure. Specific conductance, turbidity, and magnitude of water level fluctuations were important predictors of Dreissena colonization on artificial substrates.     

Phenol and catechol biodegradation by the haloalkaliphile Halomonas campisalis: influence of pH and salinity

Removal of aromatic compounds from alkaline and/or saline industrial wastewater is an environmental concern for industry. In addition, aromatics may be accumulating in soda lakes, unique natural systems, where the fate and toxicity of these contaminants is unknown. To determine the feasibility of aromatic compound biodegradation in saline and alkaline conditions, the effect of pH and salinity on the biodegradation of phenol as a model aromatic waste compound by the haloalkaliphilic bacterium Halomonas campisalis was examined. Phenol was degraded as a source of carbon and energy at pH 8-11 and 0-150 g/L NaCl. Metabolic intermediates catechol, cis,cis-muconate, and (+)-muconolactone were identified, thus indicating that phenol was degraded via the beta-ketoadipate metabolic pathway. Although phenol and catechol were completely degraded in all cases, small amounts of cis,cis-muconate accumulated proportionally to increases in pH. There was no noticeable influence of salinity on cis,cis-muconate accumulation except at 0 g/L NaCl where it was completely degraded. These results indicate that it may be feasible to use haloalkaliphiles forthe treatment of aromatics present in saline and/or alkaline systems. This is the first report of phenol and catechol biodegradation under combined saline and alkaline conditions.     

Analytical model to relate DMFC material properties to optimum fuel efficiency and system size

In the design of the direct methanol fuel cell and the evaluation of new materials and their appropriateness for inclusion, it is helpful to consider the impact of material properties on the performance of a complete system: to some degree, methanol crossover losses can be mitigated by proper system design. As such, an analytical model is developed to evaluate the methanol concentration profile across the anode backing layer and membrane of the direct methanol fuel cell. The model is integrated down the anode flow channel to determine fuel utilization as a function of the feed concentration, backing layer properties, and membrane properties. A minimum stoichiometric ratio is determined based on maintaining zero-order methanol kinetics, which allows the fuel efficiency to be optimized by controlling these physical properties. This analysis is then used to estimate the required flow rates and the size of system components such as the methanol storage tank, based on the minimum methanol flow rate that those components must produce to deliver a specified current; in this way, the system-level benefits of reduced membrane crossover can be evaluated.     

Use of X-ray computed microtomography to understand why gels reduce relative permeability to water more than that to oil

X-ray computed microtomography (XMT) was used to investigate why gels reduce relative permeability to water more than that to oil in strongly water-wet Berea sandstone. XMT allows saturation differences to be monitored for individual pores during various stages of oil, water, and gelant flooding. The method also characterizes distributions of pore size, aspect ratio, and coordination number for the porous media. We studied a Cr(III) acetate–HPAM gel that reduced permeability to water (at S_or) by a factor 80–90 times more than that to oil (at S_wr). In Berea, the gel caused disproportionate permeability reduction by trapping substantial volumes of oil that remained immobile during water flooding (i.e., 43.5% S_or before gel placement versus 78.7% S_or after gel placement). With this high trapped oil saturation, water was forced to flow through narrow films, through the smallest pores, and through the gel itself. In contrast, during oil flooding, oil pathways remained relatively free from constriction by the gel.     

Burden and cost of gastroenteritis in a Canadian community

This study estimated the health burden and costs associated with gastroenteritis in the City of Hamilton (Ontario, Canada). The number of cases, number of different resource units used, and cost per resource unit were represented by probability distributions and point estimates. These were subsequently integrated in a stochastic model to estimate the overall burden and cost in the population and to depict the uncertainty of the estimates. The estimated mean annual cost per capita was Can dollar 115. The estimated mean annual cost per case was Can dollar 1,089 and was similar to other published figures. Gastroenteritis represented a significant burden in the study population, with costs high enough to justify prevention efforts. These results, currently the most accurate available estimates for a Canadian population, can inform future economic evaluations to determine the most cost effective measures for reducing the burden and cost of gastroenteritis in the community.