Timothy L. Johnson results 39
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Monthly differences in the movement ecology of lake whitefish ( Coregonus clupeaformis ) in eastern Lake OntarioNARA Subscribed
Lake whitefish are a cold‐water species that holds cultural and economic importance throughout the Great Lakes region. Anthropogenic stressors over the last 60 years (e.g., invasive species, habitat degradation, and pollution) have caused significant declines in their populations. Furthermore, there is limited knowledge on the spatial ecology and habitat use of the species in Lake Ontario. Therefore, we used acoustic telemetry...
With an area covering just under 1 million km 2 , Australia’s Coral Sea Marine Park (CSMP) is among the largest marine protected areas globally. Yet, the demersal deep-reef fish fauna of the CSMP remains poorly described, due in part to its remote location, as well as its sheer size, much of which is inaccessible below conventional SCUBA diving depths. Recent remotely operated vehicle (ROV) explorations conducted by the Schmid...
The Toxicology Investigators Consortium 2023 Annual ReportNARA Subscribed
A comparison of the growth and development of pyjama sharks ( Poroderma africanum ) in wild and captive populationsNARA Subscribed
The pyjama shark ( Poroderma africanum ) is a Scyliorhinid species endemic to South Africa. Even though it is kept in captivity in many aquaria, there is a lack of research on its growth and development. In this study, we investigated the fertilization rate of eggs and the age at female sexual maturation in captive sharks and compared their growth to that of wild individuals. This is the first study to compare the growth of ca...
The Toxicology Investigators Consortium 2022 Annual ReportNARA Subscribed
The ENIGMA sports injury working group:– an international collaboration to further our understanding of sport-related brain injuryNARA Subscribed
Sport-related brain injury is very common, and the potential long-term effects include a wide range of neurological and psychiatric symptoms, and potentially neurodegeneration. Around the globe, researchers are conducting neuroimaging studies on primarily homogenous samples of athletes. However, neuroimaging studies are expensive and time consuming, and thus current findings from studies of sport-related brain injury are often...
Resilience of cold water aquaculture: a review of likely scenarios as climate changes in the Gulf of MaineNARA Subscribed
Climate change is one of the biggest challenges facing development and continuation of sustainable aquaculture in temperate regions. We primarily consider the ecological and physical resilience of aquaculture in the Gulf of Maine (GoM), where a thriving industry includes marine algae, extensive and intensive shellfish aquaculture, and a well‐established Atlantic salmon industry, as well as the infrastructure required to suppor...
Unconventional high-pressure Raman spectroscopy study of kinetic and peak pressure effects in plagioclase feldsparsNARA Subscribed
We present the results of a high-pressure semi-hydrostatic study of two plagioclase minerals, andesine and albite, using diamond anvil cells (DACs) to characterize in situ variations in Raman spectra under different static pressures. In this work, we also examined the kinetic effects on deformation at both long and short timescales through non-traditional experiments in which the DAC was either dropped or struck with a mallet....
TRY plant trait database – enhanced coverage and open accessNARA Subscribed
Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodivers...
Understanding the processes that determine above‐ground biomass ( AGB ) in Amazonian forests is important for predicting the sensitivity of these ecosystems to environmental change and for designing and evaluating dynamic global vegetation models ( DGVM s). AGB is determined by inputs from woody productivity [woody net primary productivity ( NPP )] and the rate at which carbon is lost through tree mortality. Here, we test whet...
Modeling trade‐offs between plant fiber and toxins: a framework for quantifying risks perceived by foraging herbivoresNARA Subscribed
When selecting habitats, herbivores must weigh multiple risks, such as predation, starvation, toxicity, and thermal stress, forcing them to make fitness trade‐offs. Here, we applied the method of paired comparisons (PC) to investigate how herbivores make trade‐offs between habitat features that influence selection of food patches. The method of PC measures utility and the inverse of utility, relative risk, and makes trade‐offs...