Testing the Temporal Stability of Accessibility Value in Residential Hedonic Prices

Purpose – This paper bridges the gap between, on the one hand, supply-driven (urban form and transportation networks) and demand-driven (action-based) accessibility to urban amenities and, on the other hand, house price dynamics as captured through panel hedonic modelling. It aims at assessing temporal changes in the valuation of accessibility, while ordering households’ priorities among access to labour market, schools and shopping outlets. Design/methodology/approach – Several indexes are built using a methodology developed by Thériault et al. (2005, published in Journal of Property Investment and Finance). They integrate car-based travel time on the road network (using GIS), distribution of opportunities (activity places) within the city, and willingness of persons to travel in order to reach specific types of activity places (mobility behaviour). While some measure centrality (potential attractiveness considering travel time, population and opportunities) others consist of action-based indexes using fuzzy logic and capture the willingness to travel in order to reach actual specific activity places (work places, schools, shopping centres, groceries). They summarise suitable opportunities available from each neighbourhood. Rescaled indices (worst - to 100 - best) are inserted simultaneously into a multiplicative hedonic model of single-family houses sold in Quebec City during years 1986, 1991 and 1996 (10,269 transactions). Manipulations of accessibility indexes are developed for ordering their relative impact on sale prices and isolate effects of each index on the variation of sale price, thus providing proxies of households’ priorities. Moreover, a panel-like modelling approach is used to control for changes in the valuation of each property-specific, taxation or accessibility attribute during the study period. Findings – This original approach proves efficient in isolating the cross-effects of urban centrality from accessibility to several types of amenities, while controlling for multicollinearity and heteroscedasticity. Results are in line with expectations. While only a few property-specific attributes experience a change in their marginal contribution to house value during the study period, all accessibility indexes do. Every single accessibility index has a much stronger effect on house values than centrality (which is still marginally significant). When buying their home, households put more emphasis on access to schools than they put on access to the labour market, which in turn, prevail over accessibility to either shopping centres or, finally, groceries. The ordering is rather stable but the actual valuation of a specific amenity may change over time. Practical implications – Better understanding the effect of accessibility to amenities on house values provides guidelines for choosing among a set of new neighbourhoods to develop in order to generate optimal fiscal effects for municipalities. It could also provide guidelines for decision making when improving transportation networks or locating new activity centres.

Testing the Temporal Stability of Accessibility Value in Residential Hedonic Prices

Purpose – This paper bridges the gap between, on the one hand, supply-driven (urban form and transportation networks) and demand-driven (action-based) accessibility to urban amenities and, on the other hand, house price dynamics as captured through panel hedonic modelling. It aims at assessing temporal changes in the valuation of accessibility, while ordering households' priorities among access to labour market, schools and shopping outlets. Design/methodology/approach – Several indexes are built using a methodology developed by Thériault et al. (2005, published in Journal of Property Investment and Finance). They integrate car-based travel time on the road network (using GIS), distribution of opportunities (activity places) within the city, and willingness of persons to travel in order to reach specific types of activity places (mobility behaviour). While some measure centrality (potential attractiveness considering travel time, population and opportunities) others consist of action-based indexes using fuzzy logic and capture the willingness to travel in order to reach actual specific activity places (work places, schools, shopping centres, groceries). They summarise suitable opportunities available from each neighbourhood. Rescaled indices (worst - to 100 - best) are inserted simultaneously into a multiplicative hedonic model of single-family houses sold in Quebec City during years 1986, 1991 and 1996 (10,269 transactions). Manipulations of accessibility indexes are developed for ordering their relative impact on sale prices and isolate effects of each index on the variation of sale price, thus providing proxies of households' priorities. Moreover, a panel-like modelling approach is used to control for changes in the valuation of each property-specific, taxation or accessibility attribute during the study period. Findings – This original approach proves efficient in isolating the cross-effects of urban centrality from accessibility to several types of amenities, while controlling for multicollinearity and heteroscedasticity. Results are in line with expectations. While only a few property-specific attributes experience a change in their marginal contribution to house value during the study period, all accessibility indexes do. Every single accessibility index has a much stronger effect on house values than centrality (which is still marginally significant). When buying their home, households put more emphasis on access to schools than they put on access to the labour market, which in turn, prevail over accessibility to either shopping centres or, finally, groceries. The ordering is rather stable but the actual valuation of a specific amenity may change over time. Practical implications – Better understanding the effect of accessibility to amenities on house values provides guidelines for choosing among a set of new neighbourhoods to develop in order to generate optimal fiscal effects for municipalities. It could also provide guidelines for decision making when improving transportation networks or locating new activity centres

Undecidable properties of self-affine sets and multi-tape automata

We study the decidability of the topological properties of some objects coming from fractal geometry. We prove that having empty interior is undecidable for the sets defined by two-dimensional graph-directed iterated function systems. These results are obtained by studying a particular class of self-affine sets associated with multi-tape automata. We first establish the undecidability of some language-theoretical properties of such automata, which then translate into undecidability results about their associated self-affine sets.Comment: 10 pages, v2 includes some corrections to match the published versio

Seismic anisotropy of the Canadian High Arctic : evidence from shear-wave splitting

FD is supported by the Natural Sciences and Engineering Research Council of Canada (NSERC/CRSNG) through its Discovery Grant and Canada Research Chair programmes [10.13039/501100000038](341802-2013-RGPIN). Data from the ELLITE stations and some of the long-term stations (Scripps Inst. Oceanography, 1986; Stephenson et al., 2013) are available through the IRIS Data Management Center; the remaining Canadian data are available through the Canadian National Data Centre, Natural Resources Canada (Geological Survey of Canada, 1989). ELLITE instrumentation was loaned to the project by SEIS-UK and the project received support from De Beers Canada and the University of Aberdeen. The ELLITE project was carried out as part of the Circum-Arctic Lithosphere Evolution (CALE) programme, and supported by Natural Resources Canada's GEM-1 programme, which also supported JMD's MSc funding. We thank the Editor and the three reviewers for their helpful comments which improved the manuscript.Peer reviewedPostprin

Real-life experience with ceftolozane/tazobactam in Canada: results from the CLEAR (Canadian LEadership on Antimicrobial Real-life usage) registry.

Objectives Ceftolozane/tazobactam is a cephalosporin/β-lactamase inhibitor combination with activity against Gram-negative bacilli. We report the use of ceftolozane/tazobactam in Canada using a national registry. Methods The CLEAR registry uses REDCapTM (Research Electronic Data Capture) (online survey, https://is.gd/CLEAR_ceftolozanetazobactam) to capture details associated with clinical use of ceftolozane/tazobactam. Results Data from 51 patients treated in 2020 with ceftolozane/tazobactam are available. Infections treated included hospital-acquired bacterial pneumonia (37.3% of patients), ventilator-associated bacterial pneumonia (15.7%), bone/joint infection (11.8%), complicated intra-abdominal infection (7.8%) and complicated skin and skin structure infection (7.8%). 17.6% of patients had bacteremia and 47.1% were in intensive care. Ceftolozane/tazobactam was primarily used as directed therapy for Pseudomonas aeruginosa infections (92.2% of patients). Ceftolozane/tazobactam was used because of resistance to (86.3%), failure of (11.7%), or adverse effects from (2.0%) previously prescribed antimicrobials. Ceftolozane/tazobactam susceptibility testing was performed on isolates from 88.2% of patients. Ceftolozane/tazobactam was used in combination with another antimicrobial active versus Gram-negative bacilli in 39.2% of patients (aminoglycosides [15.7%], fluoroquinolones [7.8%] and colistin/polymyxin B [7.8%]). The dosage regimen was customized in all patients based on their creatinine clearance. Treatment duration was primarily >10 days (60.8% of patients) with microbiological success in 60.5% and clinical success in 64.4% of patients. 7.8% of patients had adverse effects not requiring drug discontinuation. Conclusions In Canada, ceftolozane/tazobactam is used as directed therapy to treat a variety of severe infections caused MDR P. aeruginosa. It is commonly used in combination with other antimicrobials with relatively high microbiological/clinical cure rates, and an excellent safety profile

Molecular mechanisms of drug resistance in natural Leishmania populations vary with genetic background

The evolution of drug-resistance in pathogens is a major global health threat. Elucidating the molecular basis of pathogen drug-resistance has been the focus of many studies but rarely is it known whether a drug-resistance mechanism identified is universal for the studied pathogen; it has seldom been clarified whether drug-resistance mechanisms vary with the pathogen's genotype. Nevertheless this is of critical importance in gaining an understanding of the complexity of this global threat and in underpinning epidemiological surveillance of pathogen drug resistance in the field. This study aimed to assess the molecular and phenotypic heterogeneity that emerges in natural parasite populations under drug treatment pressure. We studied lines of the protozoan parasite Leishmania (L.) donovani with differential susceptibility to antimonial drugs; the lines being derived from clinical isolates belonging to two distinct genetic populations that circulate in the leishmaniasis endemic region of Nepal. Parasite pathways known to be affected by antimonial drugs were characterised on five experimental levels in the lines of the two populations. Characterisation of DNA sequence, gene expression, protein expression and thiol levels revealed a number of molecular features that mark antimonial-resistant parasites in only one of the two populations studied. A final series of in vitro stress phenotyping experiments confirmed this heterogeneity amongst drug-resistant parasites from the two populations. These data provide evidence that the molecular changes associated with antimonial-resistance in natural Leishmania populations depend on the genetic background of the Leishmania population, which has resulted in a divergent set of resistance markers in the Leishmania populations. This heterogeneity of parasite adaptations provides severe challenges for the control of drug resistance in the field and the design of molecular surveillance tools for widespread applicability

Advertising Bans and the Substitutability of Online and Offline Advertising

The authors examine whether the growth of the Internet has reduced the effectiveness of government regulation of advertising. They combine nonexperimental variation in local regulation of offline alcohol advertising with data from field tests that randomized exposure to online advertising for 275 different online advertising campaigns to 61,580 people. The results show that people are 8% less likely to say that they will purchase an alcoholic beverage in states that have alcohol advertising bans compared with states that do not. For consumers exposed to online advertising, this gap narrows to 3%. There are similar effects for four changes in local offline alcohol advertising restrictions when advertising effectiveness is observed both before and after the change. The effect of online advertising is disproportionately high for new products and for products with low awareness in places that have bans. This suggests that online advertising could reduce the effectiveness of attempts to regulate offline advertising channels because online advertising substitutes for (rather than complements) offline advertising.Google (Firm)WPP (Firm