INVESTIGATIONS OF STORM WATER MANAGEMENT PROFESSIONALS\u27 PERCEPTIONS OF PERMEABLE INTERLOCKING CONCRETE PAVERS AS A STORMWATER MANAGEMENT OPTION

ABSTRACT This study examined stormwater management professionals\u27 perceptions of PICPs (Permeable Interlocking Concrete Pavement) as a stormwater management option to conventional curb and gutter methodology from years past. A self-administered survey questionnaire was developed as the primary research methodology. Three hundred stormwater management professionals were randomly selected as research subjects, and qualitative and quantitative methods were used to collect data for the study. Specific statistical gathering methods and tests for this study included: ex post facto experimental design, grounded theory design, correlation coefficients and ANOVA, and Pearson\u27s correlation coefficients. The survey found through quantitative analysis that although stormwater professionals have very little education on the topic of PICPs, they are very familiar with the benefits of this type pavement over more traditional types of surfacing. The hypothesis that stated PICPs were not well-utilized because stormwater professionals were not familiar with them was rejected and the reason for non-use appeared to be the perceived cost factor. The survey found through qualitative analysis the following major themes: The most common jobs among survey participants were stormwater administrators, project managers, and environmental engineers. Less runoff and perviousness were the biggest incentives to using PICPs. Cost and potential maintenance were the main deterrents to using PICPs. Reduced runoff, cost, and potential maintenance were the perceived main considerations of municipal governments with regards to PICP implementation. Poor - iii - design or installation, lack of knowledge, and inadequate maintenance are the biggest nuisances in reviewing PICP projects. Several practical recommendations were proposed in this study to overcome the barriers to using PICPs as a stormwater management tool, including more education of those involved in planning, designing, and implementing PICPs through workshops and training sessions, as well as more training for installers to provide decision makers a quality product from which to choose in the future. The most important aspect of education and training seemed to be the need to focus upon a better understanding of the actual long term costs and maintenance issues associated with PICPs

Pseudomonas Aeruginosa: Resistance to the Max

Pseudomonas aeruginosa is intrinsically resistant to a variety of antimicrobials and can develop resistance during anti-pseudomonal chemotherapy both of which compromise treatment of infections caused by this organism. Resistance to multiple classes of antimicrobials (multidrug resistance) in particular is increasingly common in P. aeruginosa, with a number of reports of pan-resistant isolates treatable with a single agent, colistin. Acquired resistance in this organism is multifactorial and attributable to chromosomal mutations and the acquisition of resistance genes via horizontal gene transfer. Mutational changes impacting resistance include upregulation of multidrug efflux systems to promote antimicrobial expulsion, derepression of ampC, AmpC alterations that expand the enzyme's substrate specificity (i.e., extended-spectrum AmpC), alterations to outer membrane permeability to limit antimicrobial entry and alterations to antimicrobial targets. Acquired mechanisms contributing to resistance in P. aeruginosa include β-lactamases, notably the extended-spectrum β-lactamases and the carbapenemases that hydrolyze most β-lactams, aminoglycoside-modifying enzymes, and 16S rRNA methylases that provide high-level pan-aminoglycoside resistance. The organism's propensity to grow in vivo as antimicrobial-tolerant biofilms and the occurrence of hypermutator strains that yield antimicrobial resistant mutants at higher frequency also compromise anti-pseudomonal chemotherapy. With limited therapeutic options and increasing resistance will the untreatable P. aeruginosa infection soon be upon us

The Polarization of American Politics

Elected officials in the United States appear to represent relatively extreme support coalitions rather than the interests of middle-of-the-road voters. This contention is supported by analysis of variance of liberal-conservative positions in the United States Senate from 1959 to 1980. Within both the Democratic and the Republican parties, there is considerable variation in liberal-conservative positions, but two senators from the same state and party tend to be very similar. In contrast, senators from the same state but from different parties are highly dissimilar, suggesting that each party represents an extreme support coalition in the state. Moreover, the distribution of senators is now consistent with the hypothesis that, in the long run, both parties have an equal chance of winning any seat in the Senate. This result suggests that there is now competition between equally balanced but extreme support coalitions throughout most of the United States

A Spatial Model for Legislative Roll Call Analysis

A general nonlinear logit model is used to analyze political choice data. The model assumes probabilistic voting based on a spatial utility function. The parameters of the utility function and the spatial coordinates of the choices and the choosers can all be estimated on the basis of observed choices. Ordinary Guttman scaling is a degenerate case of this model. Estimation of the model is implemented in the NOMINATE program for one dimensional analysis of two alternative choices with no nonvoting. The robustness and face validity of the program outputs are evaluated on the basis of roll call voting data for the U.S. House and Senate. Extensive Monte Carlo studies are also presented. Substantive applications using the results for the Senate are briefly illustrated

The European Common Space: Extending the Use of Anchoring Vignettes

In this article, we combine advances in both survey research and scaling techniques to estimate a common dimension for political parties across the member states of the European Union. Most previous scholarship has either ignored or assumed cross-national comparability of party placements across a variety of dimensions. The 2010 wave of the Chapel Hill Expert Survey includes anchoring vignettes which we use as “bridge votes” to place parties from different countries on a common space. We estimate our dimensions using the “blackbox” technique. Our results demonstrate both the usefulness of anchoring vignettes and the broad applicability of the blackbox scaling routine. Further, the resulting scale offers a cross-nationally comparable interval-level measure of a party’s left/right ideological position with a high degree of face validity. In short, we argue that the left/right economic dimension travels well across European countries

Ambition meets reality: Lessons from the taro boom in Nicaragua

Between 2006 and 2011, Nicaragua shipped an average of US$ 9.4 million per year of smallholder-produced fresh taro (Colocasia esculenta) to the United States; however, by 2016, the US market for Nicaraguan taro had effectively collapsed. We analyse the short-lived taro boom from the perspective of complex adaptive systems, showing how shocks, interactions between value chain actors, and lack of adaptive capacity among chain actors together contributed to the collapse of the chain. Primary data was collected from businesses and smallholders in 2010 and 2016 to understand the actors involved, their business relations, and the benefits and set backs they experienced along the way. The results show the capacity of better-off smallholders to engage in a demanding market, but also the struggles faced by more vulnerable smallholders to build new production systems and respond to internal and external shocks. Local businesses were generally unprepared for the uncertainties inherent in fresh horticultural trade or for engagement with distant buyers. Existing guides and tools for designing value chain interventions will benefit from greater attention to the circumstances of local actors and the challenges of building productive inter-business relations under higher levels of risk and uncertainty. Results demonstrate the need for a greater awareness of adaptive capacity within marketing systems that involve smallholders, a more critical look at the underlying assumptions of interventions for building these value chains, and the need for alternative planning scenarios, better risk mitigation and adaptation strategies. This case serves as a wake-up call for practitioners, donors, researchers and the private sector on how to identify market opportunities and the design of more robust strategies to respond to them

Scaling Roll Call Votes with wnominate in R

This paper presents a software package designed to estimate Poole and Rosenthal W-NOMINATE scores in R. The package uses a logistic regression model to analyze political choice data, usually (though not exclusively) from a legislative setting. In contrast to other scaling methods, W-NOMINATE explicitly assumes probabilistic voting based on a spatial utility function, where the parameters of the utility function and the spatial coordinates of the legislators and the votes can all be estimated on the basis of observed voting behavior. Building on software written by Poole in Fortran, the new wnominate package in R facilitates easier data input and manipulation, generates bootstrapped standard errors, and includes a new suite of graphics functions to display the results. We demonstrate the functionality of this package by conducting a natural experiment using roll calls -- an experiment which is greatly simplified by the data manipulation capabilities of the wnominate package in R

Recovering a Basic Space from Issue Scales in<i>R</i>

Basicspace is an R package that conducts Aldrich-McKelvey and Blackbox scaling to recover estimates of the underlying latent dimensions of issue scale data. We illustrate several applications of the package to survey data commonly used in the social sciences. Monte Carlo tests demonstrate that the procedure can recover latent dimensions and reproduce the matrix of responses at moderate levels of error and missing data