title: Designs efficiency for non-market valuation with choice modelling: how to measure it, what to report and why

authors: Rose, John M.

subjects: efficient experimental design

abstract: We review the basic principles for the evaluation of design efficiency in discrete choice modelling with a focus on efficiency of WTP estimates from the multinomial logit model. The discussion is developed under the realistic assumption that researchers can plausibly define a prior on the utility coefficients. Some new measures of design performance in applied studies are proposed and their rationale discussed. An empirical example based on the generation and comparison of fifteen separate designs from a common set of assumptions illustrates the relevant considerations to the context of non-market valuation, with particular emphasis placed on C-efficiency. Conclusions are drawn for the practice of reporting in non-market valuation and for future work on design research.

text: Designs efficiency for non-market valuation with choice modelling: how to measure it, what to report and why We review the basic principles for the evaluation of design efficiency in discrete choice modelling with a focus on efficiency of WTP estimates from the multinomial logit model. The discussion is developed under the realistic assumption that researchers can plausibly define a prior on the utility coefficients. Some new measures of design performance in applied studies are proposed and their rationale discussed. An empirical example based on the generation and comparison of fifteen separate designs from a common set of assumptions illustrates the relevant considerations to the context of non-market valuation, with particular emphasis placed on C-efficiency. Conclusions are drawn for the practice of reporting in non-market valuation and for future work on design research.

year: 2007-10

title: A novel drifter designed for use with a mounted Acoustic Doppler Current Profiler in shallow environments

authors: Mullarney, Julia C.

subjects: Acoustic Doppler Current Profiler

abstract: We present a novel design for a surface drifter, mounted with a pulse-coherent Acoustic Doppler Current Profiler (ADCP) for measuring near-surface (depths 0.18-1 m) flows. During repeated drifter deployments over the tidal flats of Skagit Bay, the mounted ADCP recorded high quality and high resolution profiles of velocity in depths as shallow as 0.4 m. Depth-dependent velocities revealed regions of vertically sheared currents and wave motions not resolved by surface drifters alone. Although the cost of ADCPs is substantial, the drifter bodies were low cost, robust, and of simple construction.

text: A novel drifter designed for use with a mounted Acoustic Doppler Current Profiler in shallow environments We present a novel design for a surface drifter, mounted with a pulse-coherent Acoustic Doppler Current Profiler (ADCP) for measuring near-surface (depths 0.18-1 m) flows. During repeated drifter deployments over the tidal flats of Skagit Bay, the mounted ADCP recorded high quality and high resolution profiles of velocity in depths as shallow as 0.4 m. Depth-dependent velocities revealed regions of vertically sheared currents and wave motions not resolved by surface drifters alone. Although the cost of ADCPs is substantial, the drifter bodies were low cost, robust, and of simple construction.

year: 2013

title: Mycobacterium tuberculosis strains in New Zealand: phylogeny and structural biology

authors: Claire Vignette, Mulholland

subjects: tuberculosis

abstract: Mycobacterium tuberculosis is an obligate human pathogen and is the primary causative agent of tuberculosis. New Zealand has a relatively low incidence of tuberculosis disease, however, Māori (the indigenous people of New Zealand) and Pacific People are disproportionally affected. Molecular typing shows that approximately two-thirds of M. tuberculosis isolates from New Zealand-born patients can be assigned to clusters of related strains. The largest M. tuberculosis cluster in New Zealand is known as the ‘Rangipo’ cluster and is predominantly found in Māori. This strain has been the source of several tuberculosis outbreaks over the last 30 years and anecdotal evidence suggests it may be particularly virulent. Two other large clusters, known as the ‘Southern Cross’ and ‘Otara’ clusters, most commonly occur in Pacific People.
Here, whole genome sequencing, phylogenetics and structural biology were used to investigate evolutionary origins and functional consequences of genomic diversity in New Zealand M. tuberculosis clusters, with a particular focus on the Rangipo strain. Analysis of Rangipo strain non-synonymous single nucleotide polymorphisms (nsSNPs) identified bacterial genetic factors that may contribute to the high transmissibility of this strain. The F420-dependent oxidoreductase Rv2893 harbours a Rangipo-specific G72S mutation encoded by a nsSNP. H37Rv and Rangipo Rv2893 structures were solved and show the effect of this G72S mutation. Binding of the F420 cofactor was confirmed and characterised. SNP analyses also guided the optimisation of a diagnostic assay for rapid Rangipo strain classification at low cost and with high discriminatory power. Phylogenetic analyses revealed the Rangipo and Otara clusters belong to a larger M.tuberculosis clade of French/European origin that is also prevalent in indigenous populations in Canada. Molecular dating indicates dispersal of this clade to the South Pacific was driven by expanding European trade networks in the early 19th century and identifies host factors that have contributed to the dispersal and expansion of the Rangipo and Otara strains.
Overall, these results show that relatively recent changes in host ecology have likely played a crucial role in driving the success of the Rangipo strain in New Zealand and point to bacterial genetic factors that may influence its virulence and thereby also contribute to its prevalence.

text: Mycobacterium tuberculosis strains in New Zealand: phylogeny and structural biology Mycobacterium tuberculosis is an obligate human pathogen and is the primary causative agent of tuberculosis. New Zealand has a relatively low incidence of tuberculosis disease, however, Māori (the indigenous people of New Zealand) and Pacific People are disproportionally affected. Molecular typing shows that approximately two-thirds of M. tuberculosis isolates from New Zealand-born patients can be assigned to clusters of related strains. The largest M. tuberculosis cluster in New Zealand is known as the ‘Rangipo’ cluster and is predominantly found in Māori. This strain has been the source of several tuberculosis outbreaks over the last 30 years and anecdotal evidence suggests it may be particularly virulent. Two other large clusters, known as the ‘Southern Cross’ and ‘Otara’ clusters, most commonly occur in Pacific People.
Here, whole genome sequencing, phylogenetics and structural biology were used to investigate evolutionary origins and functional consequences of genomic diversity in New Zealand M. tuberculosis clusters, with a particular focus on the Rangipo strain. Analysis of Rangipo strain non-synonymous single nucleotide polymorphisms (nsSNPs) identified bacterial genetic factors that may contribute to the high transmissibility of this strain. The F420-dependent oxidoreductase Rv2893 harbours a Rangipo-specific G72S mutation encoded by a nsSNP. H37Rv and Rangipo Rv2893 structures were solved and show the effect of this G72S mutation. Binding of the F420 cofactor was confirmed and characterised. SNP analyses also guided the optimisation of a diagnostic assay for rapid Rangipo strain classification at low cost and with high discriminatory power. Phylogenetic analyses revealed the Rangipo and Otara clusters belong to a larger M.tuberculosis clade of French/European origin that is also prevalent in indigenous populations in Canada. Molecular dating indicates dispersal of this clade to the South Pacific was driven by expanding European trade networks in the early 19th century and identifies host factors that have contributed to the dispersal and expansion of the Rangipo and Otara strains.
Overall, these results show that relatively recent changes in host ecology have likely played a crucial role in driving the success of the Rangipo strain in New Zealand and point to bacterial genetic factors that may influence its virulence and thereby also contribute to its prevalence.

year: 2019