Editorial

Mitigation and Adaptation Strategies for Global Change -     

Soil vapor extraction system design: A case study comparing vacuum and pore‐gas velocity cutoff criteria

Soil vapor extraction (SVE) systems are typically designed based on the results of a vadose‐zone pumping test (transient or steady‐state) using a pressure criterion to establish the zone of influence (ZOI). A common problem associated with pressure‐based SVE design is overestimating the ZOI of the extraction well. As a result, design strategies based upon critical pore‐ gas velocity (CPGV) have become more common. Field tests were conducted at the Savannah River Site (SRS) to determine the influence of a vapor extraction well based upon both a pressure and pore‐ gas velocity design criterion. The results from these tests show that an SVE system designed based upon a CPGV is more robust and will have shorter cleanup times due to increased flow throughout the treatment zone. Pressure‐based SVE design may be appropriate in applications where soil gas containment is the primary objective; however, in cases where the capture and removal of contaminated soil gas is the primary objective, CPGV is a better design criterion. © 2006 Wiley Periodicals, Inc.     

SYSTEM ECONOMIC RESPONSE TO WATER QUANTITY AND QUALITY - FUNDAMENTAL CONSIDERATIONS1

The relationship between water quantity, water quality, and system economic response to permutations of these variables on any given water use, and the allocation of water among competing uses is outlined by means of a conceptual model. The effect of the quantity-quality variable mix on a given use is called the “intensive effect,” and the allocation mix on the total system is the “extensive effect.” The elements of the model are best described by the partial sketch of the flow diagram, outlined below in terms of symbols.     

How flies respond to honey bee pheromone: the role of the foraging gene on reproductive response to queen mandibular pheromone

In this study we test one central prediction from sociogenomic theory—that social and non-social taxa share common genetic toolkits that regulate reproduction in response to environmental cues. We exposed Drosophila females of rover (for ^R) and sitter (for ^s) genotypes to an ovary-suppressing pheromone derived from the honeybee Apis mellifera. Surprisingly, queen mandibular pheromone (QMP) affected several measures of fitness in flies, and in a manner comparable to the pheromone’s normal effect on bee workers. QMP-treated sitter flies had smaller ovaries that contained fewer eggs than did untreated controls. QMP-treated rover flies, by contrast, showed a more variable pattern that only sometimes resulted in ovary inhibition, while a third strain of fly that contains a sitter mutant allele in a rover background (for ^s2) showed no ovarian response to QMP. Taken together, our results suggest that distinctly non-social insects have some capacity to respond to social cues, but that this response varies with fly genotype. In general, the interspecific response is consistent with a conserved gene set affecting reproductive physiology. The differential response among strains in particular suggests that for is itself important for modulating the fly’s pheromonal response.     

Impacts of bioethanol on gasoline prices in the Philippines: an econometric analysis

The rising prices of crude oil in the world market and the continuing global trend to mainstream renewable energy use have prompted the Philippines to consider alternative fuels. Since 2006 when a new law was implemented requiring a 10 % blend to unleaded gasoline, the use of ethanol has increased significantly. Sugarcane (Saccharum spp.), cassava (Manihot esculenta ) and sweet potato (Ipomoea batatas) have been the major feedstock in ethanol production. This analysis focused on the impacts of E10 (10 % ethanol content) on the retail price of gasoline and how this might affect gasoline prices. Recognizing the direct dependence of the price of E10 on gasoline prices, the analysis focused on analyzing the price of ethanol. The hypothesis is that since ethanol is what makes E10 cheaper than gas given the lower cost of its production i.e., domestically grown raw materials, then cheaper ethanol should depress the price of E10 and therefore gas, ceteris paribus. The price of E10 is endogenous since it is a function of the price of gasoline, being a major input to its production, 90 % in fact. Using fixed-effects, 2007–2009 provincial panel data, from second stage least squares econometric estimation, the impact of ethanol use on retail regular gasoline prices is quantified. The partial effect analysis indicates that a 1-peso (rate: 1USD - PhP 41.96) increase in the price of feedstock prices as inputs to the production of E10 increases the price of gasoline by 37 centavos per liter. The analysis shows the positive relationship between the prices of E10 and gasoline.     

Reviewing the framework for dealing with urban environmental problems

It is now widely accepted that there are problems with the state of urban environments globally. This paper presents the commonly used approaches for dealing with environmental problems, which have been categorised into target, top-down, market-driven and participative. The problems with these approaches are discussed, and the significance of participative approaches in dealing with environmental problems at the local scale is highlighted. The paper questions the basis underlying these approaches, and concludes that a new framework is needed to provide fresh approaches for dealing with environmental problems.     

Element Levels in Snakes in South Carolina: Differences Between a Control Site and Exposed Site on the Savannah River Site

Levels of 18 elements, including lead, mercury, selenium, and uranium, were examined in three species of snakes from an exposed and reference site on the Department of Energy's Savannah River Site in South Carolina. We tested the hypotheses that there were no differences as a function of species, and there were no difference between the exposed and control site for blood and muscle (tail) samples for banded water snake (Nerodia fasciata), brown water snake (N. taxispilota) and cottonmouth (Akistrodon piscivorous). The banded water snakes collected were significantly smaller than the other two species. For blood, there were significant species differences only for barium, copper, selenium, uranium and zinc, while for muscle tissue there were significant interspecific differences in aluminum, arsenic, barium, cobalt, cesium, copper, iron, lead, mercury, manganese, strontium, vanadium and zinc, suggesting that muscle tissue in the tail is a better indicator of potential interspecific differences. It is also easier logistically to collect tail tissue than blood. Where one species had significantly higher levels than the other species in muscle tissue levels, cottonmouth had higherlevels of five elements (aluminum, cobalt, lead, mercury, vanadium), brown water snake had two (lead, strontium), and banded water snake had only barium. There were few significant differences between the control and reference site for levels of blood, but several for muscle tissue. All three species had significantly higher levels of arsenic and manganese at Tim's Branch than the reference site, and nickel and uranium were significantly higher for banded watersnake and cottonmouth, the larger species. Individuals with high exposure of one element were exposed to high levels of other elements.     

Cash and voucher assistance along humanitarian supply chains: a literature review and directions for future research

This study reviews research on cash and voucher assistance (CVA) by applying a humanitarian supply chain management perspective. A systematic literature review was conducted to identify, analyse, and synthesise past academic research. The content, context, and process framework was used to structure the content analysis. The findings reveal that the outcomes of CVA programmes are dependent on critical context-specific variables that influence feasibility and operability. Humanitarian actors must consider factors that are external (the nature of disaster, politics, economy, and infrastructure) and internal (local market availability and accessibility, supplier/donor interest, supplier/vendor selection and contracting, and beneficiary preference) to the supply chain. The delivery process is influenced by them, impacting on programme responsiveness and cost-efficiency. The results provide insights that humanitarian practitioners can utilise to reconsider their supply chain strategies when deciding on the selection and implementation of CVA programmes. Potential literature gaps are identified, and recommendations for further research are provided.