Why Do Some Water Utilities Recycle More than Others? A Qualitative Comparative Analysis in New South Wales, Australia

Although the recycling of municipal wastewater can play an important role in water supply security and ecosystem protection, the percentage of wastewater recycled is generally low and strikingly variable. Previous research has employed detailed case studies to examine the factors that contribute to recycling success but usually lacks a comparative perspective across cases. In this study, 25 water utilities in New South Wales, Australia, were compared using fuzzy-set Qualitative Comparative Analysis (fsQCA). This research method applies binary logic and set theory to identify the minimal combinations of conditions that are necessary and/or sufficient for an outcome to occur within the set of cases analyzed. The influence of six factors (rainfall, population density, coastal or inland location, proximity to users; cost recovery and revenue for water supply services) was examined for two outcomes, agricultural use and "heavy" (i.e., commercial/municipal/industrial) use. Each outcome was explained by two different pathways, illustrating that different combinations of conditions are associated with the same outcome. Generally, while economic factors are crucial for heavy use, factors relating to water stress and geographical proximity matter most for agricultural reuse. These results suggest that policies to promote wastewater reuse may be most effective if they target uses that are most feasible for utilities and correspond to the local context. This work also makes a methodological contribution through illustrating the potential utility of fsQCA for understanding the complex drivers of performance in water recycling.

Light sheet fluorescence microscopy for in situ cell interaction analysis in mouse lymph nodes.

Reactive lymph nodes (LNs) are sites where pMHC-loaded dendritic cells (DCs) interact with rare cognate T cells, leading to their clonal expansion. While DC interactions with T cell subsets critically shape the ensuing immune response, surprisingly little is known on their spatial orchestration at physiologically T cell low precursor frequencies. Light sheet fluorescence microscopy and one of its implementations, selective plane illumination microscopy (SPIM), is a powerful method to obtain precise spatial information of entire organs of 0.5-10mm diameter, the size range of murine LNs. Yet, its usefulness for immunological research has thus far not been comprehensively explored. Here, we have tested and defined protocols that preserve fluorescent protein function during lymphoid tissue clearing required for SPIM. Reconstructions of SPIM-generated 3D data sets revealed that calibrated numbers of adoptively transferred T cells and DCs are successfully detected at a single cell level within optically cleared murine LNs. Finally, we define parameters to quantify specific interactions between antigen-specific T cells and pMHC-bearing DCs in murine LNs. In sum, our studies describe the successful application of light sheet fluorescence microscopy to immunologically relevant tissues.

Elucidating the internal structure of psychophysical timing performance in the sub-second and second range by utilizing confirmatory factor analysis

The most influential theoretical account in time psychophysics assumes the existence of a unitary internal clock based on neural counting. The distinct timing hypothesis, on the other hand, suggests an automatic timing mechanism for processing of durations in the sub-second range and a cognitively controlled timing mechanism for processing of durations in the range of seconds. Although several psychophysical approaches can be applied for identifying the internal structure of interval timing in the second and sub-second range, the existing data provide a puzzling picture of rather inconsistent results. In the present chapter, we introduce confirmatory factor analysis (CFA) to further elucidate the internal structure of interval timing performance in the sub-second and second range. More specifically, we investigated whether CFA would rather support the notion of a unitary timing mechanism or of distinct timing mechanisms underlying interval timing in the sub-second and second range, respectively. The assumption of two distinct timing mechanisms which are completely independent of each other was not supported by our data. The model assuming a unitary timing mechanism underlying interval timing in both the sub-second and second range fitted the empirical data much better. Eventually, we also tested a third model assuming two distinct, but functionally related mechanisms. The correlation between the two latent variables representing the hypothesized timing mechanisms was rather high and comparison of fit indices indicated that the assumption of two associated timing mechanisms described the observed data better than only one latent variable. Models are discussed in the light of the existing psychophysical and neurophysiological data.