The DNA damage activity (DDA) assay and its application to river waters and diesel exhausts

An extremely sensitive assay has been developed for DNA-damaging chemicals using a DNA repair-deficient strain of Escherichia coli. Considerable DNA-damaging activity has been demonstrated by this assay in natural surface-water samples and in diesel-exhaust particulate extracts.     

Removal of bentazone from micro-polluted water using MIEX resin: Kinetics, equilibrium, and mechanism

The contamination of surface and ground water by bentazone has attracted increasing global concern in recent years. We conducted a detailed investigation using MIEX resin to eliminate bentazone from waters. Batch experiments were carried out to evaluate the e ect of process parameters, such as retention time, resin amount, and initial pesticide concentration, on removal e ciency of bentazone. Results showed the sorption process was fast and bentazone could be e ciently removed in 30 minutes. The kinetic process of bentazone sorption on MIEX resin was well described by pseudo second-order model and intraparticle di usion was the rate controlling step. The MIEX resin possessed the highest sorption capacity of 0.2656 mmol/mL for bentazone according to Langmuir fitting. Bentazone is a hydrophobic ionizable organic compound, and both ionic charge and hydrophobic aromatic structure governed the sorption characteristics on MIEX resin. The di erent removal e ciencies of ionic and non-ionic pesticides, combined with the charge balance equations of bentazone, SO4 2??, NO3?? and Cl??, indicated that removal of bentazone using MIEX resin occurred primarily via ion exchange.     

Status and changes of water quality in typical near-city zones of three East African Great Lakes in Tanzania

Environmental Science and Pollution Research - Tanzania is the only country bordering all three transboundary East African Great Lakes, i.e., Lake Victoria, Lake Tanganyika, and Lake Nyasa (Lake...     

Interactions between scientific uncertainty and flood management decisions: Two case studies in Colorado

Flood management policies in the United States rely on scientific information about the frequency and intensity of extreme precipitation and runoff. Yet, the available information is inherently uncertain because of the complexity of meteorological and hydrological processes. In mountainous areas, flood risk can vary greatly even within short distances depending on local climate, topography, soil characteristics, and land use. This paper describes two Colorado cases in which policy makers were presented with conflicting scientific estimates: revision of the Fort Collins floodplain map and modification of the Cherry Creek Dam. The case studies demonstrate that uncertainty can have substantial impacts on regulatory processes, public safety, and costs. The analysis considers the differing perspectives of various participants in the flood management processes, illustrating the interplay between uncertainties attributable to scientific issues and values issues. It suggests that attempts to provide a single “best” estimate do not necessarily meet the decision needs of all stakeholders. Conclusions indicate a need to improve communication about uncertainty when scientific estimates areprovided to decision makers. Furthermore, in highly controversial decisions, it may be necessary to reframe the discussion to consider the values issues raised by scientific uncertainty.     

Sharing and preparing: cross-institutional,food security-based knowledge in Canada

This study proposes a framework for the collection and management of knowledge related to food security in Canada. This paper has several goals. First, the paper summarizes the current state of food security knowledge in Canada. Second, the paper presents data from an experiment where food security issues were discussed by stakeholders at two fora, the first of which was held in western Canada and the second held in eastern Canada. Finally, based on the notes taken during and feedback received after the fora, this paper suggests a framework for organizing and managing the multiple perspectives and complex types of knowledge about food security and sustainable development from a Canadian context. Two fora were held in Canada where food security issues were presented and discussed by multiple stakeholders. Most provinces in Canada were represented in at least one of the two sessions. Sessions were designed to be informative and interactive; agenda were designed to take advantage of the needs and experiences of multiple stakeholders in both western and eastern regions of Canada. To develop the framework, the sessions were also designed to assess the types of issues and knowledge about food security in Canada. Evidence presented from this experiment supports arguments that food security work must be approached in a collaborative manner, no matter the approach or discipline. Data from fora held in western and eastern regions of Canada indicate a number of specific ways in which those along the food continuum have the desire to share knowledge and enter into partnerships to work toward secure and sustainable food systems. Data also indicate how academia and institutions of higher learning might play a key role in sharing food security-based knowledge. The data from this study suggest that academia could play a leadership role in collecting and sharing information about food security-based knowledge from all disciplinary approaches that could help collaborative in addressing the complexity of food security challenges. The framework developed in this paper could provide the guide for organizing knowledge about food security and sustainable development. The framework could be used as a map to guide understanding about the different ways in which food security can be approached and understood; this could help reduce tensions among partners in projects where a wide variety of experiences are attempting to work collaboratively. The two food security fora brought together stakeholders with specialized knowledge about food security in a Canadian context. The analysis of data arising from the fora permitted unique insights to arise about the nature of knowledge by region. The data in this study also allowed us to build a framework for food security knowledge from these regional knowledge bases. This paper suggests that academia actively take a leadership role and openly share knowledge about food security. Open sharing of knowledge will help collaborates in dealing with complex food security issues understand in-depth other approaches; this sharing may help to make explicit the tensions that arise during collaborative work.     

Are low infidelity rates in feral horses due to infanticide?

A growing number of studies conducted on diverse taxa have shown that extra-pair/group paternity is higher than what would be predicted from behavioral observations alone. While it may be beneficial for females to mate with multiple males, this often results in offspring not sired by the behavioral father, which could influence offspring survival, especially in social mammals. Feral horses (Equus caballus) maintain stable social relationships over several years, usually with one stallion defending a harem band of unrelated mares against other males. Sneak copulations by subordinate males have been observed and mares sometimes change bands, both of which can result in foals sired by males other than the dominant band stallion. We measured female fidelity in free-ranging feral horses in 23 bands, with 51 foals over four foaling seasons and tested offspring paternity against parental behaviors. We used 12 polymorphic microsatellite loci and the program CERVUS 2.0 to determine and exclude potential sires. The majority of mares remained in the band with the sire of their foal resulting in most foals being sired by the band stallion. Most foals that were not sired by the band stallion were born in the year after a round-up and we could not determine if they were the result of band changing or sneak copulations. Foals born into a band without their sire had lower survival rates and mothers were significantly more protective of foals not sired by the band stallion. These findings suggest that band stability increases the reproductive success of mares and support the importance of infanticide risk in equid social structure.     

Bridging the gap between the field and the lab: Environmental goods, policy maker input, and consequentiality

This paper explores the criterion validity of stated preference methods through experimental referenda that capture key characteristics of a stated preference survey for a proposed environmental program. In particular, we investigate whether advisory referenda, where participant votes have either known or unknown weight in the policy decision, can elicit values comparable to that of a standard, incentive-compatible referendum. When participants regard their votes as consequential, our results suggest there is no elicitation bias with advisory referenda. For advisory referenda where participants view their votes as inconsequential, and for purely hypothetical referenda, we observe elicitation bias.     

Supervisors' exceedingly difficult goals and abusive supervision: The mediating effects of hindrance stress,anger, and anxiety

This study examined a contextual predictor of abusive supervision. Specifically, we hypothesized that job goals that are judged by supervisors to be exceedingly difficult to attain is a predictor of subordinate‐rated abusive supervisory behavior. Drawing on the cognitive theory of stress, we hypothesized that exceedingly difficult job goals assigned to supervisors predict abusive behavior directed at their subordinates, as mediated by the supervisors' hindrance stress and emotions (e.g., anger and anxiety). We collected data from employees and their immediate supervisors to test this theoretical model (N = 215 matched pairs). The results of this multisource field study provided support for the hypothesized relationships. In particular, assigned job goals that were appraised by supervisors as exceedingly difficult to attain predicted their hindrance stress. Also, hindrance stress was positively related to anger and anxiety, which in turn predicted abusive supervision. Theoretically, these findings contribute to research on goal setting, stress, and abusive supervision. In addition, these findings are practically important in that they provide suggestions on how to minimize abusive supervision in organizations. Copyright © 2013 John Wiley & Sons, Ltd.