Christchurch Clinical Studies Trust

Intracontinental reverse faults in Otago and South Canterbury, Aotearoa-New Zealand, have complex surface morphologies. The Dunstan Fault and Fox Peak Fault are expressed at the surface by multiple parallel to sub-parallel fault traces. These traces can be hundreds of meters apart from each other and span a deformation zone up to 2-3km in width. We ask the following questions: Do all traces rupture together in each ground rupturing earthquake, or do they rupture independently? If traces rupture independently, is it random which trace ruptures in a given event, or is there a spatio-temporal pattern? What is the likelihood of a new trace rupturing in the next large earthquake? We use paleoseismic techniques to constrain the timings of past earthquakes on each trace. The results are compared to see if the same earthquake ruptured multiple traces. If we can tease out any spatio-temporal patterns, we may be able to answer the question: In a future ground rupturing earthquake, which trace/traces will rupture? The results have implications for fault zonation and fault displacement hazard analysis of intracontinental reverse faults in Aotearoa-New Zealand and beyond.

Flooding from fluvial and pluvial sources pose a significant and growing risk to buildings in New Zealand, yet national-scale assessments of direct economic loss are limited. This study addresses that gap by applying an end-to-end workflow that integrates state-of-the-art hydraulic modelling with a modular flood risk analysis framework, enabling consistent expected annual damage (EAD) calculation at the building scale and enumeration at different jurisdictional levels. National EAD of NZD 190 million was estimated, with Canterbury and Waikato regions contributing 35% of this total. Residential and appurtenant buildings account for the majority (71%) of national EAD. These findings provide the first comprehensive baseline for direct building economic flood risk in New Zealand, and advances that availability of flood risk models for location-based risk mitigation strategies.

ABSTRACT Digital networks are virtual representations of freshwater systems that provide important inputs to, and mapping of, river classifications, simulation models, and quantitative data analyses for policy, planning, and management. Strahler order has often been used to characterize network configuration and as a proxy indicator of river channel size and distance from headwaters. We propose and demonstrate an extension to standard Strahler ordering that uses non‐positive numbers to indicate relative positions of overland flow pathways. Non‐positive extended Strahler orders are calculated by subtracting the initially calculated standard Strahler order of the most downstream overland flow segment from: (a) the initially calculated standard Strahler order calculated for that segment; and (b) the initially calculated standard Strahler order for all upstream connected overland flow segments. The original meaning of Strahler order in terms of network configuration and relation to headwaters is preserved by applying standard Strahler ordering to assign positive numbers to network segments representing river channels. Extended Strahler ordering allows consistent comparisons between networks with different resolutions, and overland flow pathways to be distinguished from river channels within networks. A method for determining river channel headwater and sinkhole locations from cartographical maps is demonstrated because these locations are required to identify river channels within networks. The number of network segments assigned to each extended Strahler order was calculated for a case study catchment. Results demonstrated that positive Strahler orders calculated for a digital network using the extended Strahler ordering method corresponded well with those derived from cartographical maps regardless of network resolution. Extended Strahler ordering therefore provides consistency in the meaning of each Strahler order when overland flow pathways are included within a network, which is desirable if the network is being used for out‐of‐channel routing, and feasible if high‐resolution digital elevation data are available to generate detailed networks. The source of the cartographical and elevation data should be communicated when describing the origins of extended Strahler orders.

ABSTRACT Flooding is a disruptive and devastating natural hazard for communities all around the world. To combat the negative effects of flooding, it has become a global priority to implement and research flood early warning systems (FEWS). However, previous research did not comprehensively examine both the technological and social dimensions of FEWS nor the knowledge of their availability and status around the world. To address these gaps, this paper completes a narrative review and synthesizes best practices in FEWS warning and system design, and introduces a “FEWS Around the World” repository which catalogs 3–4 examples per region across six continents. Our analysis shows that while most FEWS include design features outlined in the literature such as timeliness, human capacity, and integration, fewer implement novel components related to impact‐based warnings, participatory science, bottom‐up approaches, advanced technology, and maintaining a preparedness fund, highlighting gaps and opportunities for improvement. Examples demonstrate how these characteristics manifest in diverse contexts, from community‐based systems in Nepal to AI‐driven systems like Google's Flood Hub. By bridging design principles with observed global practices, this paper is designed to aid researchers, practitioners, and communities in people‐centered FEWS development, implementation, and operation, improving resilient flood risk management.

Abstract In 2022, a suspected incursion of Oryctes rhinoceros (coconut rhinoceros beetle, CRB) was reported in Bahía de Banderas, Nayarit, México, based on damage symptoms observed on coconut palms and photographs of beetles on a social media site. This prompted collaboration with local biologists and land managers, and a survey of the area with the suspected invasion was carried out in 2024. Adult beetles and larvae were collected, and morphological features were consistent with taxonomic characteristics of O. rhinoceros . Damage to coconut palms consistent with that caused by O. rhinoceros was observed and photographed in the locations where the beetles were captured. Molecular analysis confirmed the specimens' species identity as O. rhinoceros , belonging to the CRB‐G (clade I A ) haplotype grouping. The Oryctes rhinoceros nudivirus, a biocontrol agent which is widespread in coconut rhinoceros beetle populations in some Pacific islands, was not detected. Reports of O. rhinoceros on iNaturalist, the results of this survey and DNA analysis confirm that O. rhinoceros has established for the first time in the Americas in Bahía de Banderas on the border between Nayarit and Jalisco. While the current infestation area is limited, a thorough delimiting survey should be carried out as soon as possible, and a response plan should be prepared to contain or eradicate the pest before it spreads.

BackgroundApproximately 31% of adults experience dental anxiety, which represents a significant barrier to timely care and ultimately results in poor oral health outcomes. Moderate sedation is an effective method of managing anxiety while preserving patient responsiveness. Total intravenous anesthesia (TIVA) combined with target-controlled infusion (TCI) systems, which utilize pharmacokinetic models, enable precise control of drug delivery by maintaining stable effect-site concentrations. This study evaluated the safety and efficacy of moderate TCI-administered sedation using an Eleveld pharmacodynamic-pharmacokinetic model for propofol and remifentanil in dental practice.MethodsThis prospective study included 114 patients who underwent dental procedures at two clinical sites. Moderate sedation was delivered via a TCI-guided Eleveld model, targeting the effect-site concentrations of propofol and remifentanil. The primary outcome was the incidence of adverse events as defined by the Tracking and Reporting Outcomes of Procedural Sedation criteria. The secondary outcomes included procedural duration, drug dosing, vital sign fluctuations, and patient-reported satisfaction.ResultsAfter 7725 min of sedation, no adverse events were reported according to the TROOPS criteria. None of the patients experienced hypoxia (SpO2 <90%), bradycardia (HR < 40 bpm), or clinical over-sedation. Hypotension (MAP < 65 mmHg) occurred in 13 patients who were managed conservatively without intervention. The average recovery time was 10.1 ± 5.2 min. Patient satisfaction was high (99%), with 93.6% of patients reporting little to no recall of the procedure.ConclusionsTCI-based moderate sedation using the Eleveld model for propofol and remifentanil is safe, effective, and well-tolerated in dental settings. The model offers predictable sedation depth, rapid recovery, and high levels of patient satisfaction, supporting its broader implementation in the management of dental anxiety.

SARS-CoV-2 is now endemic and expected to remain a health threat, with new variants continuing to emerge and the potential for vaccines to become less effective. While effective vaccines and natural immunity have significantly reduced hospitalisations and the need for critical care, outpatient treatment options remain limited, and real-world evidence on their clinical and cost-effectiveness is lacking. In this paper, we present the design of the Canadian Adaptive Platform Trial of Treatments for COVID in Community Settings (CanTreatCOVID). By evaluating multiple treatment options in a pragmatic adaptive platform trial, this study will generate high-quality, generalisable evidence to inform clinical guidelines and healthcare decision-making. CanTreatCOVID is an open-label, individually randomised, multicentre, national adaptive platform trial designed to evaluate the clinical and cost-effectiveness of therapeutics for non-hospitalised SARS-CoV-2 patients across Canada. Eligible participants must present with symptomatic SARS-CoV-2 infection, confirmed by PCR or rapid antigen testing (RAT), within 5 days of symptom onset. The trial targets two groups that are expected to be at higher risk of more severe disease: (1) individuals aged 50 years and older and (2) those aged 18-49 years with one or more comorbidities. CanTreatCOVID uses numerous approaches to recruit participants to the study, including a multifaceted public communication strategy and outreach through primary care, outpatient clinics and emergency departments. Participants are randomised to receive either usual care, including supportive and symptom-based management, or an investigational therapeutic selected by the Canadian COVID-19 Outpatient Therapeutics Committee. The first therapeutic arm evaluates nirmatrelvir/ritonavir (Paxlovid), administered two times per day for 5 days. The second therapeutic arm investigates a combination antioxidant therapy (selenium 300 µg, zinc 40 mg, lycopene 45 mg and vitamin C 1.5 g), administered for 10 days. The primary outcome is all-cause hospitalisation or death within 28 days of randomisation. The CanTreatCOVID master protocol and subprotocols have been approved by Health Canada and local research ethics boards in the participating provinces across Canada. The results of the study will be disseminated to policy-makers, presented at conferences and published in peer-reviewed journals to ensure that findings are accessible to the broader scientific and medical communities. This study was approved by the Unity Health Toronto Research Ethics Board (#22-179) and Clinical Trials Ontario (Project ID 4133). NCT05614349.

Phylosymbiosis describes an association between the phylogenetic relationships among host species and composition of their microbiomes. Conifers have long evolutionary histories and extensive opportunity for coevolution to have occurred among these host plants and their microbiomes. We tested for phylosymbiosis in the root microbiomes of conifer seedlings as an indicator of coevolutionary plant-microbiome selection processes or concurrent ecological filtering. We grew 23 species of Pinaceae and Cupressaceae in a common soil for 52 weeks and assessed whether similarity in bacterial and fungal root microbiome composition was based on host phylogenetic distances using correlation and topology-based methods. Relationships among soil physicochemical properties, host traits and microbial community composition were also assessed. Phylosymbiosis was significant in both bacterial and fungal root microbiomes. Host taxonomic relationships consistently explained more variance in microbiome composition than host traits or soil physicochemical properties. Indirect host effects on soil physicochemical properties, specifically sulfate sulfur, explained variation in microbiome composition in most models. We have evidence for phylosymbiosis in the root systems of conifer seedlings in both bacterial and fungal communities. This represents an important step towards uncovering patterns of coevolution in long-lived organisms and their associated microbes, and indicates the fundamental role of phylosymbiosis to root microbiome assembly.