Trends in lizard translocations in New Zealand between 1988 and 2013

There is growing concern about mitigation-driven translocations that move animals from anthropogenic threats at donor sites because of their failure rate and lack of application of scientific principles and best practice. We reviewed all known lizard translocations in New Zealand between 1988 and 2013 and identified 85 translocations of 30 lizard taxa to 46 release sites. Most translocations (62%) were motivated by conservation goals for the species or the release site, and one-third were mitigation-driven translocations, typically motivated by habitat loss due to development. Mitigation-driven translocations began in 2003, and since that time have equalled the number of conservation-motivated translocations. Conservation-motivated translocations usually released lizards on islands without mammalian predators, whereas mitigation-driven translocations usually relocated lizards to mainland sites with introduced predators. Long-term monitoring has been sparse and often rudimentary. Eight lizard translocations have recorded population growth, including one mitigation-driven translocation that was into a fenced reserve. Research on commonly used management techniques to mitigate human-related impacts is recommended to establish whether these techniques benefit lizards in the long term.     

Cox proportional hazards models with left truncation and time‐varying coefficient: Application of age at event as outcome in cohort studies

When analyzing time‐to‐event cohort data, two different ways of choosing a time scale have been discussed in the literature: time‐on‐study or age at onset of disease. One advantage of choosing the latter is interpretability of the hazard ratio as a function of age. To handle the analysis of age at onset in a principled manner, we present an analysis of the Cox Proportional Hazards model with time‐varying coefficient for left‐truncated and right‐censored data. In the analysis of Northern Manhattan Study (NOMAS) with age at onset of stroke as outcome, we demonstrate that well‐established risk factors may be important only around a certain age span and less established risk factors can have a strong effect in a certain age span.     

Assessing the Potential of Phytoremediation at a Site in the U.K. Contaminated With 137Cs

Spinacia oleracea L. cv. ‘Bloomsdale’, Beta vulgaris L. cv. ‘Flavescens’, Brassica juncea L. ‘OB825’, and Helianthus annuus L. cv. ‘Oranges and Lemons’ were grown for 8 weeks at a site contaminated with ¹³⁷Cs at Bradwell Nuclear Power Station, UK. The site was a trench approximately 1.5 m deep, 2 m wide, and 100 m long in ‘made ground’ consisting of alluvium with traces of illites, kaolinites, and smectites. ¹³⁷Cs activity concentration was measured in individual plants after 8 weeks growth and the soil in which they grew. The biomass produced and total ¹³⁷Cs removed to shoots differed significantly between species but ¹³⁷Cs activity concentrations and Transfer Factors (TFs) did not. B. vulgaris produced the most biomass and removed the greatest amount of ¹³⁷Cs. For all plants, and within each taxon, plants growing at low soil ¹³⁷Cs activity concentrations had significantly greater TFs than those growing at high soil ¹³⁷Cs activity concentrations. It is concluded that selecting plant taxa suited to a particular site can be an effective way of improving phytoremediation rates, that there is much scope for adjusting harvesting intervals to 8 weeks or less without affecting TFs, and that estimates of time taken for ¹³⁷Cs removal by phytoremediation should consider that TFs may increase as soil concentrations decrease. With refinements in methodology, phytoremediation has the potential to contribute significantly to decontamination of the site at Bradwell.