Modeling Connectivity of Non‐floodplain Wetlands: Insights,Approaches, and Recommendations

Representing hydrologic connectivity of non‐floodplain wetlands (NFWs) to downstream waters in process‐based models is an emerging challenge relevant to many research, regulatory, and management activities. We review four case studies that utilize process‐based models developed to simulate NFW hydrology. Models range from a simple, lumped parameter model to a highly complex, fully distributed model. Across case studies, we highlight appropriate application of each model, emphasizing spatial scale, computational demands, process representation, and model limitations. We end with a synthesis of recommended “best modeling practices” to guide model application. These recommendations include: (1) clearly articulate modeling objectives, and revisit and adjust those objectives regularly; (2) develop a conceptualization of NFW connectivity using qualitative observations, empirical data, and process‐based modeling; (3) select a model to represent NFW connectivity by balancing both modeling objectives and available resources; (4) use innovative techniques and data sources to validate and calibrate NFW connectivity simulations; and (5) clearly articulate the limits of the resulting NFW connectivity representation. Our review and synthesis of these case studies highlights modeling approaches that incorporate NFW connectivity, demonstrates tradeoffs in model selection, and ultimately provides actionable guidance for future model application and development.     

Marine habitat mapping in support of Marine Protected Area management in a subarctic fjord: Gilbert Bay, Labrador, Canada

This paper presents an approach that allows production of benthic substrate and habitat maps in fjord environments. This approach is used to support the management of the Gilbert Bay Marine Protected Area (MPA) in southeastern Labrador, Atlantic Canada. Multibeam sonar-derived bathymetry, seabed slope, and acoustic reflectance (backscatter) were combined using supervised classification methods and GIS with ground-truthed benthic sampling in order to derive maps of the substrates and main benthic habitats. Six acoustically distinct substrate types were identified in the fjord, and three additional substrate types without a unique acoustic signature were recognized. Ordination by multidimensional scaling and analysis of similarity generalized these to four acoustically distinct habitat types. Greatest within-habitat (alpha) diversity was found in the coralline-algae encrusted gravel habitat. Greatest between-habitat (beta) diversity was found in the management Zones 1 and 2, which have the highest level of protection. The study confirmed that the zoning plan for the MPA, which was designed to protect spawning and juvenile fish habitat for a local genetically distinct population of Atlantic cod, afforded highest levels of protection to areas with highest habitat diversity.     

The Sensitivity of Probabilistic Risk Assessment Results to Alternative Model Structures: A Case Study of Municipal Waste Incineration

Abstract

In this analysis, human health risk due to exposure to municipal waste incinerator emissions is assessed as an example of the application of probabilistic techniques (e.g., Monte Carlo or Latin Hypercube simulations). Incinerator risk assessments are characterized by the dominance of indirect exposure, thus this analysis focuses on exposure via the ingestion of locally grown foods. In addition, since exposure to 2, 3, 7, 8-TCDD drives most incinerator risk assessments, this compound is the subject of the illustrative calculations. An important part of probabilistic risk assessment is determining the relative influence of the input parameters on the magnitude of the variance in the output distribution. This constitutes an important step toward prioritizing data needs for additional research. However, under various possible model forms reflecting incompletely understood aspects of contaminant transport, differences may be observed in estimates of risk, variance in risk, and the relative contributions of individual uncertain and variable inputs to the variance. In this analysis, a sequential structural decomposition of the relationships between the input variables is used to partition the variance in the output (i.e., risk) to identify the most influential contributors to overall variance among them. For comparison, the partitioning of variance is repeated, using techniques of multivariate regression. In summary, this study considers the degree to which results of a probabilistic assessment are contingent on critical model assumptions about the representation of deposition velocity. Specifically, this analysis assesses the impact on the results of uncertainty about the best model of the vapor/particle partitioning behavior of semi-volatile airborne pollutants.     

Defining core outcomes of reproductive genetic carrier screening: A Delphi survey of Australian and New Zealand stakeholders

Objective

Understanding the value, benefits and harms of health interventions is needed to inform best practice and ensure responsible implementation of new approaches to patient care. Such value is demonstrated through the assessment of outcomes; however, which outcomes are assessed is often highly varied across studies and can hinder the ability to draw robust conclusions. The Core Outcome Development for Carrier Screening study aims to understand the outcomes that can meaningfully capture the value of reproductive genetic carrier screening (RGCS).

Method

The authors report an iterative, two-round online Delphi survey of Australian and New Zealand stakeholders to determine the degree of consensus regarding the core outcomes of RGCS. Panellists ranked 83 outcomes according to their perceived importance on a nine-point Likert scale. Using the distribution of rankings, outcomes were grouped into tiers representative of their perceived level of importance and agreement between groups.

Results

The top tier outcomes represent those agreed to be critically important for all future studies of RGCS to assess and were used to define a preliminary core outcome set encompassing the domains (1) primary laboratory outcomes, (2) pregnancy outcomes, (3) resource use and, (4) perceived utility of RGCS.

Conclusion

These findings can guide the selection of meaningful outcomes in studies aiming to demonstrate the value of RGCS. A future international consensus process will expand on these findings and guide the inclusion of diverse perspectives across the range of settings in which RGCS is offered.     

Diversity and organizational innovation: The role of employee involvement

This study examined the interactive effects of workplace diversity and employee involvement on organizational innovation. Using a sample of 182 large Canadian organizations, we found a three‐way interaction between level of employee involvement, variation in involvement, and racioethnic diversity on innovation. In organizations with high levels of employee involvement, high variation in involvement was associated with higher involvement levels among racioethnic minorities, resulting in a stronger association between diversity and innovation. Furthermore, the association between White employee involvement and innovation was significantly more positive under the condition of high involvement among racioethnic minority group members. Thus, ensuring high levels of involvement among members of historically marginalized racioethnic groups enhances the innovation effects of employee empowerment systems. Copyright © 2010 John Wiley & Sons, Ltd.     

Site Redundancy in Urban Ozone Monitoring

This article describes two statistical methods that enable air pollution control agencies to assess the effectiveness of the spatial distribution of current stationary ozone monitoring networks by providing measures of site redundancy. These methods analyze site redundancy by determining the degree to which ozone measurements at one site can be successfully predicted from data collected at other monitoring sites. The first method, the similarity (SIM) measure, calculates redundancy based on the percentage of common operational days during which two monitoring stations report similar daily maximum ozone concentrations. The second method, a modeling technique, relates site redundancy in ozone measurement to an R-squared statistic from an autoregressive model. The model uses meteorological components recorded at a central location and ozone concentrations reported by the network’s other monitoring stations. Both techniques can assist in effective allocation of limited monitoring resources and offer a statistical approach to ambient air monitoring network design. The techniques are applied to data collected at six ozone monitoring stations in Harris County, Texas, during an eight-year period in the 1980s. The methods identified two sites in the six-site network that exhibit a high degree of redundancy.     

Sequential analysis of aggressive interactions in the stalk-eyed fly Teleopsis dalmanni

Understanding the mechanisms and determinants of conflict resolution is of great theoretical and practical importance because the outcome of contests between males over limited resources such as mates, territories, and food has profound fitness consequences. Despite the large literature on the theory of conflict resolution, relatively few empirical studies explicitly test predictions related to contest structure for these models. In sexually dimorphic species of stalk-eyed flies (Diopsidae), males engage in characteristic aggressive interactions over both females and food resources. We used sequential analysis of aggressive interactions between dyads of male stalk-eyed flies to investigate patterns of escalation, behavioral matching, and physical contact in order to distinguish between three common models of conflict resolution: the sequential assessment model, the cumulative assessment model, and the energetic war of attrition. Stalk-eyed flies were shown to engage in both low- and high-intensity behaviors during interactions with patterns of escalation and no de-escalation. Aggressive interactions did not demonstrate behavioral matching between winners and losers. Stalk-eyed flies also escalated to behaviors that included physical contact without injuries. Our results provide support for the sequential assessment model based on patterns of escalation with no de-escalation, behavioral mismatching, and behaviors which include physical contact but no injuries.     

Copper availability in seven Israeli soils incubated with and without biosolids

Land application is becoming a preferred option for disposal of sewage sludge (biosolids) from wastewater treatment plants. However, it creates potential risks due to the heavy metal contents of these materials, with copper (Cu) being of chief concern. The long-term fate of biosolid metals applied to agricultural soils is not well understood, particularly in the soils of the Middle East. This investigation was conducted to determine whether the availability of Cu changes with time in biosolid-amended and nonamended soils from Israel. Seven soils, typifying the span of properties and formation environments encountered in Israel, were incubated with and without biosolids for 7 yr, and changes in organic carbon (OC) content and labile Cu concentration were determined. Isotopic exchange techniques, using 64Cu, and ion activity measurements, using a Cu2+ ion selective electrode, revealed that the available Cu concentration remained relatively low and stable over the 7-yr incubation. This was despite substantial reductions in OC. This study shows that, with regard to Cu, application of such biosolids to these soils at rates of up to 250 Mg ha(-1) does not pose a threat to the environment in the short to medium term.