The Legacy Effect of Squatter Settlements on Urban Redevelopment

The paper presents a theoretical model that seeks to answer the question of why former squatter settlements tend to upgrade/redevelop at a slower pace than otherwise similar settlements originating in the formal sector. We argue that squatter settlers’ initial strategy to access urban land creates a ‘legacy effect’ that curtails settlement upgrading possibilities even after the settlements are granted property titles. We test our model using the case of Cochabamba, Bolivia and obtain results consistent with our theoretical model prediction. Our results suggest that the commonly used ‘benign neglect while keeping the threat of eviction’ policy has profound impacts on how land is developed in the informal sector and this poses costly consequences for local governments after legalization.squatters, informal settlements, urban development, neighbourhood upgrading, urban redevelopment

The devil in the deep: Expanding the known habitat of a rare and protected fish

The accepted geographic range of a species is related to both opportunity and effort in sampling that range. In deepwater ecosystems where human access is limited, the geographic ranges of many marine species are likely to be underestimated. A chance recording from baited cameras deployed on deep uncharted reef revealed an eastern blue devil fish (Paraplesiops bleekeri) at a depth of 51 m and more than 2 km further down the continental shelf slope than previously observed. This is the first verifiable observation of eastern blue devil fish, a protected and endemic southeastern Australian temperate reef species, at depths greater than the typically accepted depth range of 30 m. Knowledge on the ecology of this and many other reef species is indeed often limited to shallow coastal reefs, which are easily accessible by divers and researchers. Suitable habitat for many reef species appears to exist on deeper offshore reefs but is likely being overlooked due to the logistics of conducting research on these often uncharted habitats. On the basis of our observation at a depth of 51 m and observations by recreational fishers catching eastern blue devil fishes on deep offshore reefs, we suggest that the current depth range of eastern blue devil fish is being underestimated at 30 m. We also observed several common reef species well outside of their accepted depth range. Notably, immaculate damsel (Mecaenichthys immaculatus), red morwong (Cheilodactylus fuscus), mado (Atypichthys strigatus), white-ear (Parma microlepis) and silver sweep (Scorpis lineolata) were abundant and recorded in a number of locations at up to a depth of at least 55 m. This underestimation of depth potentially represents a large area of deep offshore reefs and micro habitats out on the continental shelf that could contribute to the resilience of eastern blue devil fish to extinction risk and contribute to the resilience of many reef species to climate change

Estimation of Conditional Power for Cluster-Randomized Trials with Interval-Censored Endpoints

Cluster-randomized trials (CRTs) of infectious disease preventions often yield correlated, interval-censored data: dependencies may exist between observations from the same cluster, and event occurrence may be assessed only at intermittent clinic visits. This data structure must be accounted for when conducting interim monitoring and futility assessment for CRTs. In this article, we propose a flexible framework for conditional power estimation when outcomes are correlated and interval-censored. Under the assumption that the survival times follow a shared frailty model, we first characterize the correspondence between the marginal and cluster-conditional survival functions, and then use this relationship to semiparametrically estimate the cluster-specific survival distributions from the available interim data. We incorporate assumptions about changes to the event process over the remainder of the trial---as well as estimates of the dependency among observations in the same cluster---to extend these survival curves through the end of the study. Based on these projected survival functions we generate correlated interval-censored observations, and then calculate the conditional power as the proportion of times (across multiple full-data generation steps) that the null hypothesis of no treatment effect is rejected. We evaluate the performance of the proposed method through extensive simulation studies, and illustrate its use on a large cluster-randomized HIV prevention trial

Effects of a Tailored Social Marketing Campaign Targeting Smoking Policy Compliance on Smoking-Related Behaviour on Campus

Introduction. Smoking represents a significant risk to Canadians. Young people in Canada have historically had the highest smoking prevalence of any other age group. Implementing smoking policies can be an effective strategy for post-secondary campuses to interrupt smoking trajectories and reduce the risk of campus citizens being exposed to second- hand smoke, however compliance can be a barrier to achieving these outcomes. This study examined the effects of a social marketing campaign on policy-non-compliance on a post- secondary campus in Ontario, Canada. Methods. The 3-week campaign was implemented by students and focused on policy- compliance-related objectives. Six smoking sites were observed twice a day for one week before the campaign, and one week after the campaign was completed. 4 sites were designated smoking areas, as defined by the smoking policy at the institution. 2 sites were undesignated “hot-spots” where smoking was frequently observed to occur. A butt litter audit was completed before and after the campaign to determine if butt litter decreased after the campaign. Results. At designated smoking sites, using the strict policy definition of the designated smoking sites, the proportion of observed behaviour that was non-compliant decreased in designated smoking areas (-0.079, 95% CI = 0.143, -0.0151, p < .05). Noncompliant behaviours also significantly decreased after the campaign using a more lenient measure of compliance (-0.102, 95% CI = -0.203, -0.001, p < .05). At undesignated hot spots, the average number of people using the areas to smoke decreased at both sites after the campaign. The proportion of all cigarettes which were disposed of correctly in receptacles was 75.5% before the campaign and 77.4% after the campaign. It is unclear if second-hand smoke exposure was reduced for non- smoking pedestrians despite the overall reduction in non-compliant behaviours. Conclusions. Implementing a student-led, social marketing campaign focussed on improving compliance was an effective strategy to improve compliance with smoking policy