Detection of biotic responses to urbanization using fish assemblages from small streams of western Georgia,USA

We examined relationships between stream fish assemblages and land use alteration associated with urbanization in 15 lower Piedmont watersheds along an urbanization gradient north of Columbus, western Georgia. Based on land cover data from 2002 Landsat 7 TM imagery aerial photos, streams drained watersheds that were largely urban, developing (suburban), agricultural (pasture), managed pine forest, and unmanaged mixed-forest. We quantified fish seasonally from 3 run-pool segments in each stream, and used a variety of metrics as response variables in analyses of relationships between fish assemblage structure and land use and natural basin variation. In general, Georgia-Index of Biotic Integrity (GA-IBI) values, Bray-Curtis faunal similarity of streams to mean conditions within reference streams, proportions of fish as lithophilic spawners, and fish lacking eroded fins, lesions, tumors decreased with increasing urbanization. Multiple regression indicated that assemblages were explained by a combination of land use and natural basin variables (basin size, average discharge, nearest distance to a larger downstream tributary [colonization source]), with land use variables being important predictors of summer assemblages and natural basin variables being more important in winter and spring assemblages. Non-metric multidimensional scaling (NMDS) ordinations revealed strong separation between assemblages in urban watersheds and forested watersheds, whereas assemblages in agricultural and developing watersheds were intermediate between those in urban and forested watersheds. Our data suggest that fish are reliable indicators of anthropogenic disturbance at the landscape scale, at least seasonally, and may be used to forecast the magnitude of landscape-level changes in stream structure and function associated with the conversion of forests to urban/suburban land in the Southeast.     

Movement and structure as determinants of spatial representations

It was hypothesized that the cognitive representation of distances between locations in an environment is a function not only of the environment's structure, but also of a person's pattern of travel within the environment. In the present study subjects were exposed to an experimental environment in which some locations were separated either by an opaque or a transparent barrier and other locations were not separated by any barrier. As subjects learned where the locations were, they were required to follow a specific route that allowed travel between some locations in each category but not others. Afterward subjects were asked to reproduce from memory the separation between pairs of locations. The results supported the hypothesis. Recalled distance between locations was significantly affected by both movement patterns of subjects and structural aspects of the environment (type of barrier and actual separation between locations). These results are interpreted in terms of the types of information made available through particular movement patterns and the corresponding salience of that information.     

Research evidence utilization in policy development by child welfare administrators

An exploratory qualitative study was conducted to explore how child welfare administrators use research evidence in decision-making. Content analysis revealed that a cultural shift toward evidence-based practice (EBP) is occurring in Canadian child welfare organizations and multiple types of evidence inform policy decisions. Barriers to using evidence include individual, organizational, and environmental factors. Facilitating factors include the development of internal champions and organizational cultures that value EBP. Integrating research into practice and policy decisions requires a multifaceted approach of creating organizational cultures that support research utilization and supporting senior bureaucrats to use research evidence in policy development.     

Inference and Decision Making for 21st-Century Drug Development and Approval

ABSTRACT

The cost and time of pharmaceutical drug development continue to grow at rates that many say are unsustainable. These trends have enormous impact on what treatments get to patients, when they get them and how they are used. The statistical framework for supporting decisions in regulated clinical development of new medicines has followed a traditional path of frequentist methodology. Trials using hypothesis tests of “no treatment effect” are done routinely, and the p-value < 0.05 is often the determinant of what constitutes a “successful” trial. Many drugs fail in clinical development, adding to the cost of new medicines, and some evidence points blame at the deficiencies of the frequentist paradigm. An unknown number effective medicines may have been abandoned because trials were declared “unsuccessful” due to a p-value exceeding 0.05. Recently, the Bayesian paradigm has shown utility in the clinical drug development process for its probability-based inference. We argue for a Bayesian approach that employs data from other trials as a “prior” for Phase 3 trials so that synthesized evidence across trials can be utilized to compute probability statements that are valuable for understanding the magnitude of treatment effect. Such a Bayesian paradigm provides a promising framework for improving statistical inference and regulatory decision making.     

Gender dysphoric/gender variant (GD/GV) children and adolescents: summarizing what we know and what we have yet to learn

The optimal approach to treating minors with gender dysphoria/gender variance (GD/GV) is much more controversial than treating these phenomena in adults. This is because children have limited capacity to participate in decision making regarding their own treatment, and even adolescents have no legal ability to provide informed consent. Minors must, therefore, depend on parents or other caregivers to make treatment decisions on their behalf, including those that will influence the course of their lives in the long term. Presently, the highest level of evidence available for selecting among the various approaches to treatment is best characterized as "expert opinion." Yet, opinions vary widely among experts and are influenced by theoretical orientation and assumptions and beliefs regarding the origins of gender identity, as well as its perceived malleability at particular stages of development. This article outlines some of the more salient points raised by the clinicians who treat GD/GV and their discussants. This article summarizes what the editors believe is known and what has yet to be learned about minors with GD/GV, their families, their treatment, and their surrounding cultures.     

Asymptotics for Statistical Treatment Rules

This paper develops asymptotic optimality theory for statistical treatment rules in smooth parametric and semiparametric models. Manski (2000, 2002, 2004) and Dehejia (2005) have argued that the problem of choosing treatments to maximize social welfare is distinct from the point estimation and hypothesis testing problems usually considered in the treatment effects literature, and advocate formal analysis of decision procedures that map empirical data into treatment choices. We develop large‐sample approximations to statistical treatment assignment problems using the limits of experiments framework. We then consider some different loss functions and derive treatment assignment rules that are asymptotically optimal under average and minmax risk criteria.     

Excluded losses and the demand for insurance

The demand for insurance is examined when the insured asset can incur losses that are excluded from insurance coverage. These losses are negatively correlated with covered losses and hence cannot be treated as background risk. Excluded losses have strikingly different effects on the demand for insurance than does background risk and lead to a modification of many standard insurance demand results. A number of new theorems concerning the effects of excluded losses are also presented. Risk-averse and prudent decision makers reduce their demand for insurance when excluded losses increase in size or riskiness. Excluded losses are a possible explanation for why many decision makers fail to take up insurance when it is offered.     

Surprise,surprise: the New Zealand general election of 2017

ABSTRACT

This article analyses the 2017 general election in New Zealand and draws out some of its implications. The final outcome was a surprise, and its implications momentous. Events strengthened Labour under a new leader and weakened the Green and New Zealand First parties, making it possible for Labour to become a viable coalition formateur. Comparing campaign public polling results, at least some of the polls were ‘wrong’, but all added to the excitement and uncertainty. Coupled with a new Labour Party leader, that uncertainty and excitement had mobilising effects that affected the young, but not the old. Finally, this article analyses the changes to the party system, nation-wide, and in the Māori electorates, assessing the degree of two-party dominance, and draws out implications for debates about the threshold for representation.     

The role of the state in structural transition and economic crisis

As academicians, we emphasize to our students to keep up with class, and always read ahead. When I took over as President-elect of the WSSA in April of 2008, while busy communicating with the Section Coordinators and plan the 2009 Annual Conference (Reno, Nevada), I would occasionally pause and ponder what I would present for my President Address (reading ahead). What do I know that would be of interest to the general membership of the WSSA? I naturally thought of China and its economic reform, as half of my research output over the last decade has been in this area. Then, the subprime crisis came to be, and I wondered about how the economy would cope. I can claim some expertise to the former, but of no special authority regarding the latter. However, I do have some thoughts regarding the role of the State during such economic upheavals, but in a more conceptual manner than a policy solution.