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16 Projects

  • Canada
  • 2012-2021
  • 2010
  • 2012

10
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  • Funder: NIH Project Code: 5F32GM089058-02X1
    Funder Contribution: 7,850 USD
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  • Funder: EC Project Code: 244096
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  • Funder: NIH Project Code: 1F32GM089058-01
    Funder Contribution: 37,368 USD
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  • Funder: EC Project Code: 266660
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  • Funder: SNSF Project Code: 131501
    Funder Contribution: 81,050
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  • Funder: SNSF Project Code: 131511
    Funder Contribution: 169,150
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  • Funder: UKRI Project Code: NE/H012524/1
    Funder Contribution: 62,630 GBP

    The Arctic is changing rapidly. One of the clearest changes is a reduction in the extent and thickness of summer sea ice. The loss of ice is predicted to increase in the coming years as a consequence of climatic warming. There may be no summer sea ice in the Arctic by 2030. Critically, the ice acts as a shade to sunlight and as it retreats it exposes open water to illumination causing a rapid increase in the growth of marine plants (phytoplankton). These plants use up carbon dioxide (CO2) from the atmosphere and are therefore an important component of Earth's climate system. Once formed, the phytoplankton become food for herbivorous zooplankton who are able to transport this source of carbon to deeper waters where it is excreted and buried in the sediments. This process, called the 'biological pump', transfers carbon from the atmosphere and locks it away. It is important that we understand the relationships between ice, phytoplankton, zooplankton and carbon and these relationships can be simulated in models of biogeochemical cycles. The critical link in this chain is the herbivorous zooplankton. They have a particular behaviour called 'diel vertical migration' (DVM) which is a prominent feature of many marine ecosystems. The animals move quickly tens to hundreds of meters vertically around dawn and dusk in migrations that comprise the most massive periodic shifts in biomass on Earth. The classical view is that DVM occurs as a trade off by individuals between food acquisition and predator avoidance. Zooplankton move upwards to feed at night into the nearsurface where primary production occurs. Here, under the cover of darkness, the risk from visual predators is minimised. This upward/downward migration redistributes carbon fixed by photosynthesis near the surface to deeper waters, and may remove larger quantities of CO2 from the atmosphere than would otherwise be the case, reducing the rate of CO2 accumulation in the atmosphere. Studying zooplankton in the Arctic year round is difficult because of access and ice cover. One successful technique for recording DVM behaviour uses an instrument called an acoustic Doppler current profiler (ADCP). Many ADCPs have been deployed in the Arctic over the last decade to measure currents but the acoustic signals also record zooplankton migrations. Usually these data are only analysed to understand the ocean currents within the localised region where the instrument was deployed. We are at a critical time in Arctic research where we must take a wider, 'pan-Arctic' view of marine processes. We propose to work with international groups to collate, process and archive the ADCP data, creating a unique resource for studying DVM. The regular, rhythmic behaviour means that we can use numerical techniques (circadian rhythm analysis) to quantify how strong and regular the migration behaviour is and relate this to the biological communities that are present, the level of illumination and the amount of sea ice cover. We will use this knowledge to improve models of how zooplankton transport carbon, through their faecal material, to depth. Understanding zooplankton DVM is important for many reasons. Quantifying DVM behaviour will allow us to improve our ability to predict how changes in sea ice might alter changes in the way carbon is captured and stored in the productive Arctic seas. It will give us a greater insight into how and why animals undertake such regular migrations and how the timing of these migrations is controlled. By relating the acoustic data with species data we will be able to understand the role of zooplankton in Arctic ecosystems and this is of particular importance if predictions on the effect of plankton-dependent fish species are to be made.

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  • Funder: UKRI Project Code: NE/H012176/1
    Funder Contribution: 19,803 GBP

    Living birds evolved from a flightless ancestor. The changes that eventually made flight possible not only involved modifying the theropod dinosaur body plan and evolving feathers, but also required the brain and senses to be developed to cope with life off the ground. To fly, a bird needs detailed feedback about its position in the air from its organs of balance, and also from visual information. The processing of these signals mostly occurs in a region of the brain called the flocculus, which is easy to see on a bird brain because it projects like a finger from the sides of the cerebellum. The flocculus varies greatly in size between species and, because of its function in balance, this size variation may relate to certain kinds of flying behaviour. The variation might also relate to the habitat in which a species lives, because flying in enclosed environments such as forests requires different flying skills to flying over open ground. Modern X-ray micro-CT techniques now allow us to see inside the skull of both living and fossil birds, revealing how the brain of modern birds has evolved. Using CT analysis, the size of the flocculus can be determined in dinosaurs and living and extinct birds, because its shape - and that of the brain as a whole - is impressed on the inner surface of the skull. The likelihood that flocculus size relates to flying ability has led some palaeontologists to infer flying ability for early birds such as Archaeopteryx from this structure. However, the relationship between flocculus size and flying behaviour has never been tested. It might be that the dimensions of the bony pocket that houses the flocculus are an overestimate of its size because other tissues lie between the flocculus and the bone. It might also be that the size of the flocculus is related to the overall size of the bird rather than to its flying ability or habitat preference. This project intends to test these possibilities by CT scanning the skulls of nearly 100 living species, and creating 'virtual brain models' from the internal space that housed the brain in life. The volume of the flocculus in each 'virtual brain' will be measured and analysed statistically to find out if flocculus size can be used to predict flying behaviour and/or habitat, or whether the size of the bird is the controlling factor. If strong relationships are not found we will know that palaeontologists should avoid speculating on the flying ability of extinct species based on flocculus size. Alternatively, if relationships are found, our test will have provided palaeontologists with a tool to test current ideas about the evolution of avian flight, and the transition from dinosaurs to birds.

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    visibilityviews9
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  • Funder: NIH Project Code: 5F32GM089058-02
    Funder Contribution: 40,548 USD
    more_vert
  • Funder: EC Project Code: 243914
    visibility409
    visibilityviews409
    downloaddownloads655
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16 Projects
  • Funder: NIH Project Code: 5F32GM089058-02X1
    Funder Contribution: 7,850 USD
    more_vert
  • Funder: EC Project Code: 244096
    more_vert
  • Funder: NIH Project Code: 1F32GM089058-01
    Funder Contribution: 37,368 USD
    more_vert
  • Funder: EC Project Code: 266660
    more_vert
  • Funder: SNSF Project Code: 131501
    Funder Contribution: 81,050
    more_vert
  • Funder: SNSF Project Code: 131511
    Funder Contribution: 169,150
    more_vert
  • Funder: UKRI Project Code: NE/H012524/1
    Funder Contribution: 62,630 GBP

    The Arctic is changing rapidly. One of the clearest changes is a reduction in the extent and thickness of summer sea ice. The loss of ice is predicted to increase in the coming years as a consequence of climatic warming. There may be no summer sea ice in the Arctic by 2030. Critically, the ice acts as a shade to sunlight and as it retreats it exposes open water to illumination causing a rapid increase in the growth of marine plants (phytoplankton). These plants use up carbon dioxide (CO2) from the atmosphere and are therefore an important component of Earth's climate system. Once formed, the phytoplankton become food for herbivorous zooplankton who are able to transport this source of carbon to deeper waters where it is excreted and buried in the sediments. This process, called the 'biological pump', transfers carbon from the atmosphere and locks it away. It is important that we understand the relationships between ice, phytoplankton, zooplankton and carbon and these relationships can be simulated in models of biogeochemical cycles. The critical link in this chain is the herbivorous zooplankton. They have a particular behaviour called 'diel vertical migration' (DVM) which is a prominent feature of many marine ecosystems. The animals move quickly tens to hundreds of meters vertically around dawn and dusk in migrations that comprise the most massive periodic shifts in biomass on Earth. The classical view is that DVM occurs as a trade off by individuals between food acquisition and predator avoidance. Zooplankton move upwards to feed at night into the nearsurface where primary production occurs. Here, under the cover of darkness, the risk from visual predators is minimised. This upward/downward migration redistributes carbon fixed by photosynthesis near the surface to deeper waters, and may remove larger quantities of CO2 from the atmosphere than would otherwise be the case, reducing the rate of CO2 accumulation in the atmosphere. Studying zooplankton in the Arctic year round is difficult because of access and ice cover. One successful technique for recording DVM behaviour uses an instrument called an acoustic Doppler current profiler (ADCP). Many ADCPs have been deployed in the Arctic over the last decade to measure currents but the acoustic signals also record zooplankton migrations. Usually these data are only analysed to understand the ocean currents within the localised region where the instrument was deployed. We are at a critical time in Arctic research where we must take a wider, 'pan-Arctic' view of marine processes. We propose to work with international groups to collate, process and archive the ADCP data, creating a unique resource for studying DVM. The regular, rhythmic behaviour means that we can use numerical techniques (circadian rhythm analysis) to quantify how strong and regular the migration behaviour is and relate this to the biological communities that are present, the level of illumination and the amount of sea ice cover. We will use this knowledge to improve models of how zooplankton transport carbon, through their faecal material, to depth. Understanding zooplankton DVM is important for many reasons. Quantifying DVM behaviour will allow us to improve our ability to predict how changes in sea ice might alter changes in the way carbon is captured and stored in the productive Arctic seas. It will give us a greater insight into how and why animals undertake such regular migrations and how the timing of these migrations is controlled. By relating the acoustic data with species data we will be able to understand the role of zooplankton in Arctic ecosystems and this is of particular importance if predictions on the effect of plankton-dependent fish species are to be made.

    visibility10
    visibilityviews10
    downloaddownloads5
    Powered by Usage counts
    more_vert
  • Funder: UKRI Project Code: NE/H012176/1
    Funder Contribution: 19,803 GBP

    Living birds evolved from a flightless ancestor. The changes that eventually made flight possible not only involved modifying the theropod dinosaur body plan and evolving feathers, but also required the brain and senses to be developed to cope with life off the ground. To fly, a bird needs detailed feedback about its position in the air from its organs of balance, and also from visual information. The processing of these signals mostly occurs in a region of the brain called the flocculus, which is easy to see on a bird brain because it projects like a finger from the sides of the cerebellum. The flocculus varies greatly in size between species and, because of its function in balance, this size variation may relate to certain kinds of flying behaviour. The variation might also relate to the habitat in which a species lives, because flying in enclosed environments such as forests requires different flying skills to flying over open ground. Modern X-ray micro-CT techniques now allow us to see inside the skull of both living and fossil birds, revealing how the brain of modern birds has evolved. Using CT analysis, the size of the flocculus can be determined in dinosaurs and living and extinct birds, because its shape - and that of the brain as a whole - is impressed on the inner surface of the skull. The likelihood that flocculus size relates to flying ability has led some palaeontologists to infer flying ability for early birds such as Archaeopteryx from this structure. However, the relationship between flocculus size and flying behaviour has never been tested. It might be that the dimensions of the bony pocket that houses the flocculus are an overestimate of its size because other tissues lie between the flocculus and the bone. It might also be that the size of the flocculus is related to the overall size of the bird rather than to its flying ability or habitat preference. This project intends to test these possibilities by CT scanning the skulls of nearly 100 living species, and creating 'virtual brain models' from the internal space that housed the brain in life. The volume of the flocculus in each 'virtual brain' will be measured and analysed statistically to find out if flocculus size can be used to predict flying behaviour and/or habitat, or whether the size of the bird is the controlling factor. If strong relationships are not found we will know that palaeontologists should avoid speculating on the flying ability of extinct species based on flocculus size. Alternatively, if relationships are found, our test will have provided palaeontologists with a tool to test current ideas about the evolution of avian flight, and the transition from dinosaurs to birds.

    visibility9
    visibilityviews9
    downloaddownloads18
    Powered by Usage counts
    more_vert
  • Funder: NIH Project Code: 5F32GM089058-02
    Funder Contribution: 40,548 USD
    more_vert
  • Funder: EC Project Code: 243914
    visibility409
    visibilityviews409
    downloaddownloads655
    Powered by Usage counts
    more_vert