Nicholas Bell results 27
· Newest (Page 1/2, per page 25)
Author: Nicholas Bell ×Clear All Filters
Search Results
The adoption of climate-resilient potato varieties (CRPVs) in Kenya remains limited despite sustained investments in breeding for tolerance to drought, heat, and emerging pests and diseases. Existing studies frequently explain this gap through isolated constraints such as low farmer awareness, limited seed access, or poor varietal performance. This review instead conceptualises low adoption as a consequence of systemic misalig...
Trust is recognised as a critical element of disaster risk reduction; it shapes how people perceive risks, mobilise resources, and respond to hazards. Here, trust is defined as an individual’s confidence in the ability and/ or intention of a system to act in their best interest. Importantly, many studies do not distinguish between ability- and intention-trust or acknowledge that such a distinction exists. Here, we present a sy...
Motivation Here, we make available a second version of the BioTIME database, which compiles records of abundance estimates for species in sample events of ecological assemblages through time. The updated version expands version 1.0 of the database by doubling the number of studies and includes substantial additional curation to the taxonomic accuracy of the records, as well as the metadata. Moreover, we now provide an R packag...
Global Marine Flyways Identified for Long‐Distance Migrating Seabirds From Tracking DataNARA Subscribed
Aim To identify the broad‐scale oceanic migration routes (‘marine flyways’) used by multiple pelagic, long‐distance migratory seabirds based on a global compilation of tracking data. Location Global. Time Period 1989–2023. Major Taxa Studied Seabirds (Families: Phaethontidae, Hydrobatidae, Diomedeidae, Procellariidae, Laridae and Stercorariidae). Methods We collated a comprehensive global tracking dataset that included the mig...
Parasite Abundance‐Occupancy Relationships Across Biogeographic Regions: Joint Effects of Niche Breadth, Host Availability and ClimateNARA Subscribed
Aim Changing biodiversity and environmental conditions may allow multi‐host pathogens to spread among host species and affect prevalence. There are several widely acknowledged theories about mechanisms that may influence variation in pathogen prevalence, including the controversially debated dilution effect and abundance‐occupancy relationship hypotheses. Here, we explore such abundance‐occupancy relationships for unique linea...
Co‐mast: Harmonized seed production data for woody plants across US long‐term research sitesNARA Subscribed
Plants display a range of temporal patterns of inter‐annual reproduction, from relatively constant seed production to “mast seeding,” the synchronized and highly variable interannual seed production of plants within a population. Previous efforts have compiled global records of seed production in long‐lived plants to gain insight into seed production, forest and animal population dynamics, and the effects of global change on m...
A diversity of endosymbionts across Australian aphids and their persistence in aphid culturesNARA Subscribed
There is increasing interest in the use of endosymbionts in pest control, which will benefit from the identification of endosymbionts from potential donor species for transfer to pest species. Here, we screened for endosymbionts in 123 Australian aphid samples across 32 species using 16S DNA metabarcoding. We then developed a qPCR method to validate the metabarcoding data set and to monitor endosymbiont persistence in aphid cu...
Sampling under ice-covered seas, such as the Chukchi and Bering, is difficult. Vessels capable of working in ice are limited, ice destroys surface floats, and ice keels on the shallow Chukchi shelf can extend downward 30 m, confining subsurface moorings to the near bottom. Hence, there is limited data from beneath the ice and in the marginal ice-edge zones. The Innovative Technology for Arctic Exploration (ITAE) program focuse...
Genomic erosion in a demographically recovered bird species during conservation rescueNARA Subscribed
The pink pigeon ( Nesoenas mayeri ) is an endemic species of Mauritius that has made a remarkable recovery after a severe population bottleneck in the 1970s to early 1990s. Prior to this bottleneck, an ex situ population was established from which captive‐bred individuals were released into free‐living subpopulations to increase population size and genetic variation. This conservation rescue led to rapid population recovery to...
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...
Global drivers of avian haemosporidian infections vary across zoogeographical regionsNARA Subscribed
Aim Macroecological analyses provide valuable insights into factors that influence how parasites are distributed across space and among hosts. Amid large uncertainties that arise when generalizing from local and regional findings, hierarchical approaches applied to global datasets are required to determine whether drivers of parasite infection patterns vary across scales. We assessed global patterns of haemosporidian infection...
Quantifying the level of population connectivity within and between geographically separated single-species deep-water fisheries stocks will be vital for designing effective management plans to preserve such populations. Despite this, stock structure in many fisheries is still poorly described and, at best, subject to precautionary management. Here we use rapidly evolving mitochondrial genes and microsatellite markers to inves...
Investigating historical gene flow in species complexes can indicate how environmental and reproductive barriers shape genome divergence during speciation. The processes influencing species diversification under environmental change remain one of the central focal points of evolutionary biology, particularly for marine organisms with high dispersal potential. We investigated genome‐wide divergence, introgression patterns and i...
Spatial patterns of genetic diversity among Australian alpine flora communities revealed by comparative phylogenomicsNARA Subscribed
Aim The alpine region of mainland Australia is one of the world's 187 biodiversity hotspots. Genetic analyses of Australian alpine fauna indicate high levels of endemism on fine spatial scales, unlike Northern Hemisphere alpine systems where shallow genetic differentiation is typically observed among populations. These discrepancies have been attributed to differences in elevation and influence from glacial activity, and point...