Helen Collins results 29
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Aotearoa New Zealand’s marine carbon cycle in a changing climate – Current understanding and future directionsNARA Subscribed
The marine system plays a critical role in the global climate cycle, as a major control of atmospheric carbon dioxide (CO 2 ). Marine primary production (photosynthesis) and remineralisation of organic carbon (respiration, degradation) determine the amount of CO 2 sequestered in marine sediments and deep‐water environments on century to millennial timescales. The stocks and fluxes of the marine carbon cycle are susceptible to...
Modelling the variability and dynamics of river plumes in Hawke’s Bay, Aotearoa New ZealandOA Marine
A quarter of the freshwater entering the global ocean originates from small rivers, yet the dynamics and environmental impacts of plumes generated by small rivers are understudied. Numerous small rivers with varying discharge rates terminate in Hawke’s Bay, Aotearoa New Zealand (NZ) delivering large amounts of terrigenous material to the bay. In this study, a realistic, high-resolution hydrodynamic model configuration is used...
Continuous home cage monitoring of activity and sleep in mice during repeated paroxetine treatment and discontinuationNARA Subscribed
Rationale Non-invasive home cage monitoring is emerging as a valuable tool to assess the effects of experimental interventions on mouse behaviour. A field in which these techniques may prove useful is the study of repeated selective serotonin reuptake inhibitor (SSRI) treatment and discontinuation. SSRI discontinuation syndrome is an under-researched condition that includes the emergence of sleep disturbances following treatme...
Closing the gap between science and management of cold‐water refuges in rivers and streamsNARA Subscribed
Human activities and climate change threaten coldwater organisms in freshwater ecosystems by causing rivers and streams to warm, increasing the intensity and frequency of warm temperature events, and reducing thermal heterogeneity. Cold‐water refuges are discrete patches of relatively cool water that are used by coldwater organisms for thermal relief and short‐term survival. Globally, cohesive management approaches are needed...
City infrastructure ontologiesNARA Subscribed
Building accurate physical-biogeochemical models of processes driving climate and eutrophication-related stressors in coastal waters is an essential step in managing the impacts of these stressors. Here we develop a coupled physical-biogeochemical model to investigate present day processes for a key marine ecosystem in Aotearoa, New Zealand: The Hauraki Gulf/Firth of Thames system. Simulation results compared well with an acco...
Riparian plant species offer a range of organic resources to stream invertebrate communities through varied leaf breakdown ratesNARA Subscribed
Riparian plants provide an important source of energy for freshwater food webs through inputs of leaf litter. Planting riparian buffers with mixed species could enhance the detrital resource supply for invertebrates through varied leaf breakdown rates. To quantify leaf breakdown rates and invertebrate colonisation, we used leaves from eleven grass, shrub and tree species common along agricultural waterways in New Zealand. Brea...
Comprehensive analysis of epigenetic clocks reveals associations between disproportionate biological ageing and hippocampal volumeNARA Subscribed
The concept of age acceleration, the difference between biological age and chronological age, is of growing interest, particularly with respect to age-related disorders, such as Alzheimer’s Disease (AD). Whilst studies have reported associations with AD risk and related phenotypes, there remains a lack of consensus on these associations. Here we aimed to comprehensively investigate the relationship between five recognised meas...
Common, low-frequency, rare, and ultra-rare coding variants contribute to COVID-19 severityNARA Subscribed
The combined impact of common and rare exonic variants in COVID-19 host genetics is currently insufficiently understood. Here, common and rare variants from whole-exome sequencing data of about 4000 SARS-CoV-2-positive individuals were used to define an interpretable machine-learning model for predicting COVID-19 severity. First, variants were converted into separate sets of Boolean features, depending on the absence or the pr...
The transition from winter to spring represents a major shift in the basal energy source for the Antarctic marine ecosystem from lipids and other sources of stored energy to sunlight. Because sea ice imposes a strong control on the transmission of sunlight into the water column during the polar spring, we hypothesized that the timing of the sea ice retreat influences the timing of the transition from stored energy to photosynt...
Introduced aquatic macrophytes can dominate small agricultural waterways in summer and autumn becoming a significant management problem. Excessive growth can clog waterways, causing drainage issues and reducing agricultural productivity while in‐stream velocities are reduced and sedimentation increased. Consequently, water managers remove them by mechanical clearance, chemical spray and cutting which can be costly and have neg...
Evaluating practical macrophyte control tools on small agricultural waterways in Canterbury, New ZealandNARA Subscribed
Excessive macrophytes can cause significant problems in agricultural waterways requiring active management. Conventional control techniques can have a range of adverse effects. We investigated several control tools in two experiments: firstly, we tested eight treatments at a small‐scale (2 m × 2 m). We found intensive hand weeding, weed mat and herbicide spraying to be effective treatments, reducing macrophyte cover to
A comparative approach to assess drivers of success in mammalian conservation recovery programsNARA Subscribed
The outcomes of species recovery programs have been mixed; high‐profile population recoveries contrast with species‐level extinctions. Each conservation intervention has its own challenges, but to inform more effective management it is imperative to assess whether correlates of wider recovery program success or failure can be identified. To contribute to evidence‐based improvement of future conservation strategies, we conducte...