Steven Ralph results 32
· Newest (Page 1/2, per page 25)
Author: Steven Ralph ×Clear All Filters
Search Results
Marine megafauna species are affected by a wide range of anthropogenic threats. To evaluate the risk of such threats, species’ vulnerability to each threat must first be determined. We build on the existing threats classification scheme and ranking system of the International Union for Conservation of Nature (IUCN) Red List of Threatened Species by assessing the vulnerability of 256 marine megafauna species to 23 at‐sea threat...
The Toxicology Investigators Consortium 2024 Annual ReportNARA Subscribed
Observed and projected changes in snow accumulation and snowline in California’s snowy mountainsNARA Subscribed
The Sierra Nevada and Southern Cascades—California’s snowy mountains—are primary freshwater sources and natural reservoirs for the states of California and Nevada. These mountains receive precipitation overwhelmingly from wintertime storms including atmospheric rivers (ARs), much of it falling as snow at the higher elevations. Using a seven-decade record of daily observed temperature and precipitation as well as a snow reanaly...
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...
Unrestricted gene flow between two subspecies of translocated brushtail possums (Trichosurus vulpecula) in Aotearoa New ZealandNARA Subscribed
Two lineages of brushtail possums ( Trichosurus vulpecula ) were historically introduced to Aotearoa New Zealand, and these two subspecies have different phenotypic forms. Despite over 100 years of potential interbreeding, they appear to retain morphological differences, which may indicate reproductive isolation. We examined this using population samples from a confined landscape and scored each specimen for phenotype using a...
Evaluating the potential of full‐waveform lidar for mapping pan‐tropical tree species richnessNARA Subscribed
Aim Mapping tree species richness across the tropics is of great interest for effective conservation and biodiversity management. In this study, we evaluated the potential of full‐waveform lidar data for mapping tree species richness across the tropics by relating measurements of vertical canopy structure, as a proxy for the occupation of vertical niche space, to tree species richness. Location Tropics. Time period Present. Ma...
Macroalgal communities in Australia and around the world store vast quantities of carbon in their living biomass, but their prevalence of growing on hard substrata means that they have limited capacity to act as long‐term carbon sinks. Unlike other coastal blue carbon habitats such as seagrasses, saltmarshes and mangroves, they do not develop their own organic‐rich sediments, but may instead act as a rich carbon source and mak...
A dynamic model of the cellular carbon to chlorophyll ratio applied to a batch culture and a continental shelf ecosystemNARA Subscribed
A novel parameterization of the dynamical relationship between cellular carbon (C) and chlorophyll (Chl) is developed using a Chl synthesis term that includes the physiological status of the cell and the effect of packaging of pigments within cells. The geometric derivation highlights the non‐linear relationship between Chl content and absorption due to the package effect. When parameterized for a generic 3 µm radius phytoplan...
The interaction between land use and catchment physiognomy: understanding avifaunal patterns of the Murray–Darling Basin, AustraliaNARA Subscribed
Aim We assessed whether different patterns of land use within similar physiognomic catchments (= watersheds) produced discernible effects on avian assemblages and, if so, whether such effects were related to particular land‐use activities (e.g. extensive cropping). Location Murray–Darling Basin in south‐eastern Australia. Methods We used a recently (2007) published physiognomic classification of catchments based on different s...
Observations of tidal flows in Te Aumiti (French Pass), the fastest such flows in New Zealand, were conducted in 2006 using a vessel‐mounted acoustic Doppler current profiler (ADCP), pressure sensors, a current meter mooring, drifters, and microwave radar. The suite of measurements revealed spring tide currents exceeding 4 m s ‐1 , but only in the throat of the pass. The pressure sensors either side of the pass indicated a pha...