Topography of mountain belts controlled by rheology and surface processes.

It is widely recognized that collisional mountain belt topography is generated by crustal thickening and lowered by river bedrock erosion, linking climate and tectonics1-4. However, whether surface processes or lithospheric strength control mountain belt height, shape and longevity remains uncertain. Additionally, how to reconcile high erosion rates in some active orogens with long-term survival of mountain belts for hundreds of millions of years remains enigmatic. Here we investigate mountain belt growth and decay using a new coupled surface process5,6 and mantle-scale tectonic model7. End-member models and the new non-dimensional Beaumont number, Bm, quantify how surface processes and tectonics control the topographic evolution of mountain belts, and enable the definition of three end-member types of growing orogens: type 1, non-steady state, strength controlled (Bm > 0.5); type 2, flux steady state8, strength controlled (Bm ≈ 0.4-0.5); and type 3, flux steady state, erosion controlled (Bm < 0.4). Our results indicate that tectonics dominate in Himalaya-Tibet and the Central Andes (both type 1), efficient surface processes balance high convergence rates in Taiwan (probably type 2) and surface processes dominate in the Southern Alps of New Zealand (type 3). Orogenic decay is determined by erosional efficiency and can be subdivided into two phases with variable isostatic rebound characteristics and associated timescales. The results presented here provide a unified framework explaining how surface processes and lithospheric strength control the height, shape, and longevity of mountain belts.

Emergence of methicillin resistance predates the clinical use of antibiotics.

The discovery of antibiotics more than 80 years ago has led to considerable improvements in human and animal health. Although antibiotic resistance in environmental bacteria is ancient, resistance in human pathogens is thought to be a modern phenomenon that is driven by the clinical use of antibiotics1. Here we show that particular lineages of methicillin-resistant Staphylococcus aureus-a notorious human pathogen-appeared in European hedgehogs in the pre-antibiotic era. Subsequently, these lineages spread within the local hedgehog populations and between hedgehogs and secondary hosts, including livestock and humans. We also demonstrate that the hedgehog dermatophyte Trichophyton erinacei produces two ß-lactam antibiotics that provide a natural selective environment in which methicillin-resistant S. aureus isolates have an advantage over susceptible isolates. Together, these results suggest that methicillin resistance emerged in the pre-antibiotic era as a co-evolutionary adaptation of S. aureus to the colonization of dermatophyte-infected hedgehogs. The evolution of clinically relevant antibiotic-resistance genes in wild animals and the connectivity of natural, agricultural and human ecosystems demonstrate that the use of a One Health approach is critical for our understanding and management of antibiotic resistance, which is one of the biggest threats to global health, food security and development.

Fluid-rich subducting topography generates anomalous forearc porosity.

The role of subducting topography on the mode of fault slip-particularly whether it hinders or facilitates large megathrust earthquakes-remains a controversial topic in subduction dynamics1-5. Models have illustrated the potential for subducting topography to severely alter the structure, stress state and mechanics of subduction zones4,6; however, direct geophysical imaging of the complex fracture networks proposed and the hydrology of both the subducting topography and the associated upper plate damage zones remains elusive. Here we use passive and controlled-source seafloor electromagnetic data collected at the northern Hikurangi Margin, New Zealand, to constrain electrical resistivity in a region of active seamount subduction. We show that a seamount on the incoming plate contains a thin, low-porosity basaltic cap that traps a conductive matrix of porous volcaniclastics and altered material over a resistive core, which allows 3.2 to 4.7 times more water to subduct, compared with normal, unfaulted oceanic lithosphere. In the forearc, we image a sediment-starved plate interface above a subducting seamount with similar electrical structure to the incoming plate seamount. A sharp resistive peak within the subducting seamount lies directly beneath a prominent upper plate conductive anomaly. The coincidence of this upper plate anomaly with the location of burst-type repeating earthquakes and seismicity associated with a recent slow slip event7 directly links subducting topography to the creation of fluid-rich damage zones in the forearc that alter the effective normal stress at the plate interface by modulating the fluid overpressure. In addition to severely modifying the structure and physical conditions of the upper plate, subducting seamounts represent an underappreciated mechanism for transporting a considerable flux of water to the forearc and deeper mantle.

Hemispheric black carbon increase after the 13th-century Maori arrival in New Zealand.

New Zealand was among the last habitable places on earth to be colonized by humans1. Charcoal records indicate that wildfires were rare prior to colonization and widespread following the 13th- to 14th-century Maori settlement2, but the precise timing and magnitude of associated biomass-burning emissions are unknown1,3, as are effects on light-absorbing black carbon aerosol concentrations over the pristine Southern Ocean and Antarctica4. Here we used an array of well-dated Antarctic ice-core records to show that while black carbon deposition rates were stable over continental Antarctica during the past two millennia, they were approximately threefold higher over the northern Antarctic Peninsula during the past 700 years. Aerosol modelling5 demonstrates that the observed deposition could result only from increased emissions poleward of 40° S-implicating fires in Tasmania, New Zealand and Patagonia-but only New Zealand palaeofire records indicate coincident increases. Rapid deposition increases started in 1297 (±30 s.d.) in the northern Antarctic Peninsula, consistent with the late 13th-century Maori settlement and New Zealand black carbon emissions of 36 (±21 2 s.d.) Gg y-1 during peak deposition in the 16th century. While charcoal and pollen records suggest earlier, climate-modulated burning in Tasmania and southern Patagonia6,7, deposition in Antarctica shows that black carbon emissions from burning in New Zealand dwarfed other preindustrial emissions in these regions during the past 2,000 years, providing clear evidence of large-scale environmental effects associated with early human activities across the remote Southern Hemisphere.

The tuatara genome reveals ancient features of amniote evolution.

The tuatara (Sphenodon punctatus)-the only living member of the reptilian order Rhynchocephalia (Sphenodontia), once widespread across Gondwana1,2-is an iconic species that is endemic to New Zealand2,3. A key link to the now-extinct stem reptiles (from which dinosaurs, modern reptiles, birds and mammals evolved), the tuatara provides key insights into the ancestral amniotes2,4. Here we analyse the genome of the tuatara, which-at approximately 5 Gb-is among the largest of the vertebrate genomes yet assembled. Our analyses of this genome, along with comparisons with other vertebrate genomes, reinforce the uniqueness of the tuatara. Phylogenetic analyses indicate that the tuatara lineage diverged from that of snakes and lizards around 250 million years ago. This lineage also shows moderate rates of molecular evolution, with instances of punctuated evolution. Our genome sequence analysis identifies expansions of proteins, non-protein-coding RNA families and repeat elements, the latter of which show an amalgam of reptilian and mammalian features. The sequencing of the tuatara genome provides a valuable resource for deep comparative analyses of tetrapods, as well as for tuatara biology and conservation. Our study also provides important insights into both the technical challenges and the cultural obligations that are associated with genome sequencing.

Temperate rainforests near the South Pole during peak Cretaceous warmth.

The mid-Cretaceous period was one of the warmest intervals of the past 140 million years1-5, driven by atmospheric carbon dioxide levels of around 1,000 parts per million by volume6. In the near absence of proximal geological records from south of the Antarctic Circle, it is disputed whether polar ice could exist under such environmental conditions. Here we use a sedimentary sequence recovered from the West Antarctic shelf-the southernmost Cretaceous record reported so far-and show that a temperate lowland rainforest environment existed at a palaeolatitude of about 82° S during the Turonian-Santonian age (92 to 83 million years ago). This record contains an intact 3-metre-long network of in situ fossil roots embedded in a mudstone matrix containing diverse pollen and spores. A climate model simulation shows that the reconstructed temperate climate at this high latitude requires a combination of both atmospheric carbon dioxide concentrations of 1,120-1,680 parts per million by volume and a vegetated land surface without major Antarctic glaciation, highlighting the important cooling effect exerted by ice albedo under high levels of atmospheric carbon dioxide.

Preventive percutaneous coronary intervention versus optimal medical therapy alone for the treatment of vulnerable atherosclerotic coronary plaques (PREVENT): a multicentre, open-label, randomised controlled trial.

BACKGROUND: Acute coronary syndrome and sudden cardiac death are often caused by rupture and thrombosis of lipid-rich atherosclerotic coronary plaques (known as vulnerable plaques), many of which are non-flow-limiting. The safety and effectiveness of focal preventive therapy with percutaneous coronary intervention of vulnerable plaques in reducing adverse cardiac events are unknown. We aimed to assess whether preventive percutaneous coronary intervention of non-flow-limiting vulnerable plaques improves clinical outcomes compared with optimal medical therapy alone. METHODS: PREVENT was a multicentre, open-label, randomised controlled trial done at 15 research hospitals in four countries (South Korea, Japan, Taiwan, and New Zealand). Patients aged 18 years or older with non-flow-limiting (fractional flow reserve >0·80) vulnerable coronary plaques identified by intracoronary imaging were randomly assigned (1:1) to either percutaneous coronary intervention plus optimal medical therapy or optimal medical therapy alone, in block sizes of 4 or 6, stratified by diabetes status and the performance of percutaneous coronary intervention in a non-study target vessel. Follow-up continued annually in all enrolled patients until the last enrolled patient reached 2 years after randomisation. The primary outcome was a composite of death from cardiac causes, target-vessel myocardial infarction, ischaemia-driven target-vessel revascularisation, or hospitalisation for unstable or progressive angina, assessed in the intention-to-treat population at 2 years. Time-to-first-event estimates were calculated with the Kaplan-Meier method and were compared with the log-rank test. This report is the principal analysis from the trial and includes all long-term analysed data. The trial is registered at ClinicalTrials.gov, NCT02316886, and is complete. FINDINGS: Between Sept 23, 2015, and Sept 29, 2021, 5627 patients were screened for eligibility, 1606 of whom were enrolled and randomly assigned to percutaneous coronary intervention (n=803) or optimal medical therapy alone (n=803). 1177 (73%) patients were men and 429 (27%) were women. 2-year follow-up for the primary outcome assessment was completed in 1556 (97%) patients (percutaneous coronary intervention group n=780; optimal medical therapy group n=776). At 2 years, the primary outcome occurred in three (0·4%) patients in the percutaneous coronary intervention group and in 27 (3·4%) patients in the medical therapy group (absolute difference -3·0 percentage points [95% CI -4·4 to -1·8]; p=0·0003). The effect of preventive percutaneous coronary intervention was directionally consistent for each component of the primary composite outcome. Serious clinical or adverse events did not differ between the percutaneous coronary intervention group and the medical therapy group: at 2 years, four (0·5%) versus ten (1·3%) patients died (absolute difference -0·8 percentage points [95% CI -1·7 to 0·2]) and nine (1·1%) versus 13 (1·7%) patients had myocardial infarction (absolute difference -0·5 percentage points [-1·7 to 0·6]). INTERPRETATION: In patients with non-flow-limiting vulnerable coronary plaques, preventive percutaneous coronary intervention reduced major adverse cardiac events arising from high-risk vulnerable plaques, compared with optimal medical therapy alone. Given that PREVENT is the first large trial to show the potential effect of the focal treatment for vulnerable plaques, these findings support consideration to expand indications for percutaneous coronary intervention to include non-flow-limiting, high-risk vulnerable plaques. FUNDING: The CardioVascular Research Foundation, Abbott, Yuhan Corp, CAH-Cordis, Philips, and Infraredx, a Nipro company.

Rates and causes of death after release from incarceration among 1 471 526 people in eight high-income and middle-income countries: an individual participant data meta-analysis.

BACKGROUND: Formerly incarcerated people have exceptionally poor health profiles and are at increased risk of preventable mortality when compared with their general population peers. However, not enough is known about the epidemiology of mortality in this population-specifically the rates, causes, and timing of death in specific subgroups and regions-to inform the development of targeted, evidence-based responses. We aimed to document the incidence, timing, causes, and risk factors for mortality after release from incarceration. METHODS: We analysed linked administrative data from the multi-national Mortality After Release from Incarceration Consortium (MARIC) study. We examined mortality outcomes for 1 471 526 people released from incarceration in eight countries (Australia, Brazil, Canada, New Zealand, Norway, Scotland, Sweden, and the USA) from 1980 to 2018, across 10 534 441 person-years of follow-up (range 0-24 years per person). We combined data from 18 cohort studies using two-step individual participant data meta-analyses to estimate pooled all-cause and cause-specific crude mortality rates (CMRs) per 100 000 person-years, for specific time periods (first, daily from days 1-14; second, weekly from weeks 3-12; third, weeks 13-52 combined; fourth, weeks 53 and over combined; and fifth, total follow-up) after release, overall and stratified by age, sex, and region. FINDINGS: 75 427 deaths were recorded. The all-cause CMR during the first week following release (1612 [95% CI 1048-2287]) was higher than during all other time periods (incidence rate ratio [IRR] compared with week 2: 1·5 [95% CI 1·2-1·8], I2=26·0%, weeks 3-4: 2·0 [1·5-2·6], I2=53·0%, and weeks 9-12: 2·2 [1·6-3·0], I2=70·5%). The highest cause-specific mortality rates during the first week were due to alcohol and other drug poisoning (CMR 657 [95% CI 332-1076]), suicide (135 [36-277]), and cardiovascular disease (71 [16-153]). We observed considerable variation in cause-specific CMRs over time since release and across regions. Pooled all-cause CMRs were similar between males (731 [95% CI 630-839]) and females (660 [560-767]) and were higher in older age groups. INTERPRETATION: The markedly elevated rate of death in the first week post-release underscores an urgent need for investment in evidence-based, coordinated transitional healthcare, including treatment for mental illness and substance use disorders to prevent post-release deaths due to suicide and overdose. Temporal variations in rates and causes of death highlight the need for routine monitoring of post-release mortality. FUNDING: Australia's National Health and Medical Research Council.

Near-term forecasting of Covid-19 cases and hospitalisations in Aotearoa New Zealand.

Near-term forecasting of infectious disease incidence and consequent demand for acute healthcare services can support capacity planning and public health responses. Despite well-developed scenario modelling to support the Covid-19 response, Aotearoa New Zealand lacks advanced infectious disease forecasting capacity. We develop a model using Aotearoa New Zealand's unique Covid-19 data streams to predict reported Covid-19 cases, hospital admissions and hospital occupancy. The method combines a semi-mechanistic model for disease transmission to predict cases with Gaussian process regression models to predict the fraction of reported cases that will require hospital treatment. We evaluate forecast performance against out-of-sample data over the period from 2 October 2022 to 23 July 2023. Our results show that forecast performance is reasonably good over a 1-3 week time horizon, although generally deteriorates as the time horizon is lengthened. The model has been operationalised to provide weekly national and regional forecasts in real-time. This study is an important step towards development of more sophisticated situational awareness and infectious disease forecasting tools in Aotearoa New Zealand.

The amplitude and origin of sea-level variability during the Pliocene epoch.

Earth is heading towards a climate that last existed more than three million years ago (Ma) during the 'mid-Pliocene warm period'1, when atmospheric carbon dioxide concentrations were about 400 parts per million, global sea level oscillated in response to orbital forcing2,3 and peak global-mean sea level (GMSL) may have reached about 20 metres above the present-day value4,5. For sea-level rise of this magnitude, extensive retreat or collapse of the Greenland, West Antarctic and marine-based sectors of the East Antarctic ice sheets is required. Yet the relative amplitude of sea-level variations within glacial-interglacial cycles remains poorly constrained. To address this, we calibrate a theoretical relationship between modern sediment transport by waves and water depth, and then apply the technique to grain size in a continuous 800-metre-thick Pliocene sequence of shallow-marine sediments from Whanganui Basin, New Zealand. Water-depth variations obtained in this way, after corrections for tectonic subsidence, yield cyclic relative sea-level (RSL) variations. Here we show that sea level varied on average by 13 ± 5 metres over glacial-interglacial cycles during the middle-to-late Pliocene (about 3.3-2.5 Ma). The resulting record is independent of the global ice volume proxy3 (as derived from the deep-ocean oxygen isotope record) and sea-level cycles are in phase with 20-thousand-year (kyr) periodic changes in insolation over Antarctica, paced by eccentricity-modulated orbital precession6 between 3.3 and 2.7 Ma. Thereafter, sea-level fluctuations are paced by the 41-kyr period of cycles in Earth's axial tilt as ice sheets stabilize on Antarctica and intensify in the Northern Hemisphere3,6. Strictly, we provide the amplitude of RSL change, rather than absolute GMSL change. However, simulations of RSL change based on glacio-isostatic adjustment show that our record approximates eustatic sea level, defined here as GMSL unregistered to the centre of the Earth. Nonetheless, under conservative assumptions, our estimates limit maximum Pliocene sea-level rise to less than 25 metres and provide new constraints on polar ice-volume variability under the climate conditions predicted for this century.

A new chronology for the Maori settlement of Aotearoa (NZ) and the potential role of climate change in demographic developments.

Understanding the role of climate change, resource availability, and population growth in human mobility remains critically important in anthropology. Researching linkages between climate and demographic changes during the short settlement history of Aotearoa (New Zealand) requires temporal precision equivalent to the period of a single generation. However, current modeling approaches frequently use small terrestrial radiocarbon datasets, a practice that obscures past Maori population patterns and their connection to changing climate. Our systematic analysis of terrestrial and marine 14C ages has enabled robust assessments of the largest dataset yet collated from island contexts. This analysis has been made possible by the recent development of a temporal marine correction for southern Pacific waters, and our findings show the shortcomings of previous models. We demonstrate that human settlement in the mid to late 13th century AD is unambiguous. We highlight initial (AD 1250 to 1275) settlement in the North Island. The South Island was reached a decade later (AD 1280 to 1295), where the hunting of giant flightless moa commenced (AD 1300 to 1415), and the population grew rapidly. Population growth leveled off around AD 1340 and declined between AD 1380 and 1420, synchronous with the onset of the Little Ice Age and moa loss as an essential food source. The population continued to grow in the more economically stable north, where conditions for horticulture were optimal. The enhanced precision of this research afforded by the robust analysis of marine dates opens up unique opportunities to investigate interconnectivity in Polynesia and inform the patterns seen in other island contexts.

A single introduction of wild rabbits triggered the biological invasion of Australia.

Biological invasions are a major cause of environmental and economic disruption. While ecological factors are key determinants of their success, the role of genetics has been more challenging to demonstrate. The colonization of Australia by the European rabbit is one of the most iconic and devastating biological invasions in recorded history. Here, we show that despite numerous introductions over a 70-y period, this invasion was triggered by a single release of a few animals that spread thousands of kilometers across the continent. We found genetic support for historical accounts that these were English rabbits imported in 1859 by a settler named Thomas Austin and traced the origin of the invasive population back to his birthplace in England. We also find evidence of additional introductions that established local populations but have not spread geographically. Combining genomic and historical data we show that, contrary to the earlier introductions, which consisted mostly of domestic animals, the invasive rabbits had wild ancestry. In New Zealand and Tasmania, rabbits also became a pest several decades after being introduced. We argue that the common denominator of these invasions was the arrival of a new genotype that was better adapted to the natural environment. These findings demonstrate how the genetic composition of invasive individuals can determine the success of an introduction and provide a mechanism by which multiple introductions can be required for a biological invasion.

Multiple arterial vs. single arterial coronary artery bypass grafting: sex-related differences in outcomes.

BACKGROUND AND AIMS: Uncertainty exists over whether multiple arterial grafting has a sex-related association with survival after coronary artery bypass grafting. This study aims to compare the long-term survival of using multiple arterial grafting vs. single arterial grafting in women and men undergoing coronary artery bypass grafting. METHODS: The retrospective study used the Australian and New Zealand Society of Cardiothoracic Surgical Database with linkage to the National Death Index. Patients from 2001 to 2020 were identified. Sex-stratified, inverse probability weighted Cox proportional hazard model was used to facilitate survival comparisons. The primary outcome was all-cause mortality. RESULTS: A total number of 54 275 adult patients receiving at least two grafts in primary isolated bypass operations were analysed. The entire study cohort consisted of 10 693 (19.7%) female patients and 29 711 (54.7%) multiple arterial grafting procedures. At a median (interquartile range) postoperative follow-up of 4.9 (2.3-8.4) years, mortality was significantly lower in male patients undergoing multiarterial than single arterial procedures (adjusted hazard ratio 0.82; 95% confidence interval 0.77-0.87; P < .001). The survival benefit was also significant for females (adjusted hazard ratio 0.83; 95% confidence interval 0.76-0.91; P < .001) at a median (interquartile range) follow-up of 5.2 (2.4-8.7) years. The interaction model from Cox regression suggested insignificant subgroup effect from sex (P = .08) on the observed survival advantage. The survival benefits associated with multiple arterial grafting were consistent across all sex-stratified subgroups except for female patients with left main coronary disease. CONCLUSIONS: Compared to single arterial grafting, multiple arterial revascularization is associated with improved long-term survival for women as well as men.

Long-term outcomes after hospitalization for atrial fibrillation or flutter.

BACKGROUND AND AIMS: Atrial fibrillation (AF) and flutter are common causes of hospitalizations but contemporary long-term outcomes following these episodes are uncertain. This study assessed outcomes up to 10 years after an acute AF or flutter hospitalization. METHODS: Patients hospitalized acutely with a primary diagnosis of AF or flutter from 2008-17 from all public and most private hospitals in Australia and New Zealand were included. Kaplan-Meier methods and flexible parametric survival modelling were used to estimate survival and loss in life expectancy, respectively. Competing risk model accounting for death was used when estimating incidence of non-fatal outcomes. RESULTS: A total of 260 492 adults (mean age 70.5 ± 14.4 years, 49.6% female) were followed up for 1 068 009 person-years (PY), during which 69 167 died (incidence rate 6.5/100 PY) with 91.2% survival at 1 year, 72.7% at 5 years, and 55.2% at 10 years. Estimated loss in life expectancy was 2.6 years, or 16.8% of expected life expectancy. Re-hospitalizations for heart failure (2.9/100 PY), stroke (1.7/100 PY), and myocardial infarction (1.1/100 PY) were common with respective cumulative incidences of 16.8%, 11.0%, and 7.1% by 10 years. Re-hospitalization for AF or flutter occurred in 21.3% by 1 year, 35.3% by 5 years, and 41.2% by 10 years (11.6/100 PY). The cumulative incidence of patients undergoing catheter ablation of AF was 6.5% at 10 years (1.2/100 PY). CONCLUSIONS: Patients hospitalized for AF or flutter had high death rates with an average 2.6-year loss in life expectancy. Moreover, re-hospitalizations for AF or flutter and related outcomes such as heart failure and stroke were common with catheter ablation used infrequently for treatment, which warrant further actions.

Associations between type 1 diabetes and educational outcomes: an Aotearoa/New Zealand nationwide birth cohort study using the Integrated Data Infrastructure.

AIMS/HYPOTHESIS: Type 1 diabetes is one of the most common chronic diseases of childhood. It is hypothesised that the metabolic and psychosocial consequences of type 1 diabetes may affect educational outcomes; however, existing literature presents conflicting results. This study aimed to assess whether educational outcomes differ for young people with and without type 1 diabetes in Aotearoa/New Zealand (NZ). METHODS: This was a nationwide 9 year birth cohort study of all people born in NZ from 1993 to 2001 using linked administrative data held within the Integrated Data Infrastructure, a national research database containing linked health and non-health data. Educational outcomes of high school attainment, high school attendance and university enrolment were measured from age 13 years until 20 years. Generalised linear regression models with log link and Gaussian distributions were used to compare educational outcomes between those with and those without type 1 diabetes, adjusting for sociodemographic and maternal characteristics. RESULTS: Of the 442,320 children in the birth cohort, type 1 diabetes was identified in 2058 (0.47%) (mean [SD] age of type 1 diabetes diagnosis 7.7 [3.4] years). Educational outcomes were significantly lower for children with type 1 diabetes than for those without type 1 diabetes, including for any high school qualification (RR 0.97 [95% CI 0.95, 0.99]), university entrance-level high school attainment (RR 0.88 [95% CI 0.84, 0.92]), regular high school attendance (RR 0.91 [95% CI 0.85, 0.97]) and university enrolment (RR 0.93 [95% CI 0.88, 0.98]), even after adjusting for sociodemographic and maternal factors. In addition, educational outcomes were substantially lower for those with post type 1 diabetes diagnosis hospitalisations for diabetic ketoacidosis and hypoglycaemia. CONCLUSIONS/INTERPRETATION: In this whole NZ birth cohort study, type 1 diabetes was associated with lower educational outcomes spanning secondary school and into university enrolment. Ongoing efforts to support students with type 1 diabetes are needed, particularly for those with a greater risk profile.

Detecting Nonadditive Biotic Interactions and Assessing Their Biological Relevance among Temperate Rainforest Trees.

AbstractInteractions between and within abiotic and biotic processes generate nonadditive density-dependent effects on species performance that can vary in strength or direction across environments. If ignored, nonadditivities can lead to inaccurate predictions of species responses to environmental and compositional changes. While there are increasing empirical efforts to test the constancy of pairwise biotic interactions along environmental and compositional gradients, few assess both simultaneously. Using a nationwide forest inventory that spans broad ambient temperature and moisture gradients throughout New Zealand, we address this gap by analyzing the diameter growth of six focal tree species as a function of neighbor densities and climate, as well as neighbor × climate and neighbor × neighbor statistical interactions. The most complex model featuring all interaction terms had the highest predictive accuracy. Compared with climate variables, biotic interactions typically had stronger effects on diameter growth, especially when subjected to nonadditivities from local climatic conditions and the density of intermediary species. Furthermore, statistically strong (or weak) nonadditivities could be biologically irrelevant (or significant) depending on whether a species pair typically interacted under average or more extreme conditions. Our study highlights the importance of considering both the statistical potential and the biological relevance of nonadditive biotic interactions when assessing species performance under global change.

Performance of cardiovascular disease risk prediction equations in more than 14 000 survivors of cancer in New Zealand primary care: a validation study.

BACKGROUND: People with cancer have an increased risk of cardiovascular disease. Risk prediction equations developed in New Zealand accurately predict 5-year cardiovascular disease risk in a general primary care population in the country. We assessed the performance of these equations for survivors of cancer in New Zealand. METHODS: For this validation study, patients aged 30-74 years from the PREDICT open cohort study, which was used to develop the New Zealand cardiovascular disease risk prediction equations, were included in the analysis if they had a primary diagnosis of invasive cancer at least 2 years before the date of the first cardiovascular disease risk assessment. The risk prediction equations are sex-specific and include the following predictors: age, ethnicity, socioeconomic deprivation index, family history of cardiovascular disease, smoking status, history of atrial fibrillation and diabetes, systolic blood pressure, total cholesterol to HDL cholesterol ratio, and preventive pharmacotherapy (blood-pressure-lowering, lipid-lowering, and antithrombotic drugs). Calibration was assessed by comparing the mean predicted 5-year cardiovascular disease risk, estimated using the risk prediction equations, with the observed risk across deciles of risk, for men and women, and according to the three clinical 5-year cardiovascular disease risk groups in New Zealand guidelines (<5%, 5% to <15%, and ≥15%). Discrimination was assessed by Harrell's C statistic. FINDINGS: 14 263 patients were included in the study. The mean age was 61 years (SD 9) for men and 60 years (SD 8) for women, with a median follow-up of 5·8 years for men and 5·7 years for women. The observed cardiovascular disease risk was underpredicted by a maximum of 2·5% in male and 3·2% in female decile groups. When patients were grouped according to clinical risk groups, observed cardiovascular disease risk was underpredicted by less than 2% in the lower risk groups and overpredicted by 2·2% for men and 3·3% for women in the highest risk group. Harrell's C statistics were 0·67 (SE 0·01) for men and 0·73 (0·01) for women. INTERPRETATION: The New Zealand cardiovascular disease risk prediction equations reasonably predicted the observed 5-year cardiovascular disease risk in survivors of cancer in the country, in whom risk prediction was considered clinically appropriate. Prediction could be improved by adding cancer-specific variables and considering competing risks. Our findings suggest that the equations are reasonable clinical tools for use in survivors of cancer in New Zealand. FUNDING: Auckland Medical Research Foundation, Health Research Council of New Zealand.

Host population crashes disrupt the diversity of associated marine microbiomes.

Host-associated microbial communities are shaped by myriad factors ranging from host conditions, environmental conditions and other microbes. Disentangling the ecological impact of each of these factors can be particularly difficult as many variables are correlated. Here, we leveraged earthquake-induced changes in host population structure to assess the influence of population crashes on marine microbial ecosystems. A large (7.8 magnitude) earthquake in New Zealand in 2016 led to widespread coastal uplift of up to ~6 m, sufficient to locally extirpate some intertidal southern bull kelp populations. These uplifted populations are slowly recovering, but remain at much lower densities than at nearby, less-uplifted sites. By comparing the microbial communities of the hosts from disturbed and relatively undisturbed populations using 16S rRNA gene amplicon sequencing, we observed that disturbed host populations supported higher functional, taxonomic and phylogenetic microbial beta diversity than non-disturbed host populations. Our findings shed light on microbiome ecological assembly processes, particularly highlighting that large-scale disturbances that affect host populations can dramatically influence microbiome structure. We suggest that disturbance-induced changes in host density limit the dispersal opportunities of microbes, with host community connectivity declining with the density of host populations.