This project focuses on Totten and Denman glaciers, East Antarctica, which are influenced by ice-shelf melting. In situ observations constraining the ocean heat content causing the melt, however, are limited. To fill this gap, the project will use Air-Launched Autonomous Micro Observer (ALAMO profilers) to telemeter back repeated hydrographic profiles near the ice-shelf fronts to complement other planned ship-based efforts in these areas. Remote sensing data will be used to provide updated and improved estimates of the melt rate for each shelf. The combined melt and oceanographic data will be used to constrain parameterized transfer functions for cavity melting in response to ocean temperature, improving on current parametrizations based on limited data. These melt functions will be used with ocean temperatures from climate models to force a basin-scale, open-source ice-flow model to determine the century-scale response for a variety of scenarios, helping to reduce uncertainty in sea level contributions from this part of Antarctica. Processes other than melt that might further alter the response will also be examined. For example, as flow speed increases, damage to ice-shelf shear margins increases, potentially introducing a positive feedback. Another potential factor is reductions in ice-shelf extent that decrease buttressing and increase ice loss. To investigate these processes, numerical experiments using varying degrees of damage and ice-shelf loss will help determine the extent to which these factors might further increase sea level. Through the air-deployment of float profilers from a sonobuoy launch tube in polar settings, a long-term impact of the project will be to raise the technology readiness of operational in-situ monitoring of the rapidly changing polar shelf seas, paving the way for a transformative expansion of observations of ocean hydrographic properties from remote areas that currently are understood poorly.

Over 40% of the human body is made up of skeletal muscle, which are essential for breathing, and for movement. Skeletal muscles are composed of numerous cells called muscle fibres. Within the muscle fibres, two main proteins called myosin and actin are organised into thick and thin filaments respectively, and these filaments have highly precise, lengths. These filaments are organised into muscle sarcomeres, which are in turn organised in long linear arrays from one end of the muscle fibre to the other. The interaction of myosin with actin in each muscle sarcomere drives a small shortening of each sarcomere (known as a contraction), which is summed along the muscle fibre, to drive muscle shortening, which in turn drives movement. Genetic alterations to the genes that encode part of the myosin molecule mean that a faulty (or mutant) protein is made, and this leads to severe muscle weakness in patients, in a type of disease known as myosinopathies. We do not understand how these faulty (or mutant) myosin proteins cause skeletal muscle weakness. Our research will help us to obtain a new understanding of how faulty myosin proteins cause myosinopathies. We will be able to test how mutations affect the molecular structure of the myosin, how this affects its ability to form precisely built filaments, and how this then results in changes to muscle structure, leading to muscle weakness. Our approaches will range from investigating individual fragments of myosin to investigating the organisation and properties of myosin in intact human patient samples to enable us to obtain a deep understanding. This new knowledge will not only greatly advance our understanding of myosinopathies, but, most importantly, suggest pharmacological targets that may be exploited for effective therapeutic interventions.

United States

Since the discovery of Sedna in 2007, the past decade has seen the discovery of a population of distant Solar System objects (often referred to as Inner Oort cloud objects [IOCs]) on a highly eccentric orbits beyond the Kuiper belt. The very existence of these distant small bodies challenges our understanding of the Solar System. These orbits are well beyond the reach of the known giant planets and could not be scattered into their highly eccentric orbits from interactions with Neptune alone. IOCs orbit too far from the edge of the Solar System to feel the perturbing effects of passing stars or galactic tides in the present-day solar neighborhood. Some other mechanism in the Solar System current or past architecture is required to emplace these extreme Solar System minor planets on their orbits. The orbits of these distant planetoids are the fossilized record of their formation. Each of the proposed scenarios offered to explain the formation of the IOCs leaves a distinctive imprint on the members of this distant population and has profound consequences for our understanding of the Solar System's origin and evolution. The majority of the known IOCs appear to come to perihelion at similar locations on the sky, which is currently proposed to be due to the active gravitational shepherding from an unseen 9th planet at ~200 au or beyond. Although there is compelling evidence to suggest the possibility of an ice giant planet beyond Neptune, there are results from other modern-day out Solar System surveys that seem to conflict with this hypothesis. To help unravel this mystery, this New Applicant Scheme proposal seeks to study the origin and properties of this distant collection of planetesimals and what they reveal about the dynamical history and environment of the outer Solar System.

Magma mixing has been shown to be an important process in triggering volcanic eruptions. The triggering process is likely related to the increase in pressure due to bubble formation which accompanies magma mixing. Because magmas are complex liquids, their interaction is also not straightforward. But most magmas contain crystals and these can be used to record the history of magmatic interaction, in much the same way as a black box contains the detailed record of an aircraft's flight. Crystals can be read rather like tree rings - the outer rims (and the tiny crystals or 'microlites' which form at the last stage of crystallisation) reflect the magma environment immediately before or during eruption, while crystal cores reflect past environments which existed before the magmas came in contact with each other. When magmas interact there are three important consequences; 1) crystals which existed in the precursor magmas may be transferred from one liquid to another, accompanied by some degree of mixing of the liquids 2) as the liquids try to mix they commonly do so incompletely, and form magmatic blobs or 'enclaves' of one magma in the other. Many crystals found in the enclaves originated in the magma which is now seen as the host. The tendency to form these enclaves, and the sizes, shapes and abundances are controlled by the difference in composition of the original liquids. In any case enclave formation is an intermediate step before complete mixing of the liquids. As such the preservation of enclaves in volcanic rocks gives us a vitally useful 'snapshot' of the system allowing us to measure the distribution of crystals, their sizes and compositions 3) the magma mixing process itself leads to a change in crystallisation conditions, typically promoting the formation of microlites in the enclaves due to a combination of cooling (relative to the more evolved host magma) and raising of the liquidus due to loss of volatiles (bubbles) from the liquid. Since crystals have the capacity to lock in the record of the changing environment as magma mixing takes place, then we can; 1. Measure the chemical compositions of the crystals and liquids (now solidified to glass) and use equilibrium relationships (such as Fe-Mg or Ca-Al partitioning) to establish what the liquid compositions were at various stages of growth, and therefore when crystals were transferred from one liquid to another 2. Use the 'diffusion clock' of chemical gradients in the crystals responding to changes in equilibrium conditions to determine how long before eruption (when diffusion effectively stops) the crystals were transferred. Since the crystal transfer marks the earliest stages of magma mixing, and this mixing may be the trigger for an eruption, then these timescales can help us predict future eruptions 3. Measure the sizes and shapes of crystals in enclaves and host rock to see whether a particular type of crystal is preferentially entrained We intend to carry out these studies on two natural recent volcanic systems; Kameni (Santorini, Greece) and Lassen (California, USA) where a great deal of geochemical. Petrographic and volocanological work has already been done to characterise the system, and where mixing textures and enclaves are well-preserved. In parallel to the work on natural samples, we plan to approach the problem from the opposite direction by carrying out experiments to simulate crystal exchange during magma mixing. These experiments will allow us to evaluate which criteria (crystal shape? liquid viscosities?) are most important in controlling crystal exchange. We expect our measurements from natural systems to inform the conditions we build into the experiments, and ultimately we expect to derive simple empirical relationships among them to describe this exchange. This work will then interface with numerical models being developed by colleagues which badly need some realistic boundary conditions.