Design of Marine Protected Areas on high seas and territorial waters of rockall bank

Fisheries closures are rapidly being developed to protect vulnerable marine ecosystems worldwide. Satellite monitoring of fishing vessel activity indicates that these closures can work effectively with good compliance by international fleets even in remote areas. Here we summarise how remote fisheries closures were designed to protect Lophelia pertusa habitat in a region of the NE Atlantic that straddles the EU fishing zone and the high seas. We show how scientific records, fishers' knowledge and surveillance data on fishing activity can be combined to provide a powerful tool for the design of Marine Protected Areas. © Inter-Research 2009

Star formation and ISM morphology in tidally induced spiral structures

Tidal encounters are believed to be one of the key drivers of galactic spiral structure in the Universe. Such spirals are expected to produce different morphological and kinematic features compared to density wave and dynamic spiral arms. In this work we present high resolution simulations of a tidal encounter of a small mass companion with a disc galaxy. Included are the effects of gas cooling and heating, star formation and stellar feedback. The structure of the perturbed disc differs greatly from the isolated galaxy, showing clear spiral features that act as sites of new star formation, and displaying interarm spurs. The two arms of the galaxy, the bridge and tail, appear to behave differently; with different star formation histories and structure. Specific attention is focused on offsets between gas and stellar spiral features which can be directly compared to observations. We find some offsets do exist between different media, with gaseous arms appearing mostly on the convex side of the stellar arms, though the exact locations appear highly time dependent. These results further highlight the differences between tidal spirals and other theories of arm structure.Comment: 17 pages, 19 colour figures, accepted for publication in MNRA

On the effective turbulence driving mode of molecular clouds formed in disc galaxies

We determine the physical properties and turbulence driving mode of molecular clouds formed in numerical simulations of a Milky Way-type disc galaxy with parsec-scale resolution. The clouds form through gravitational fragmentation of the gas, leading to average values for mass, radii and velocity dispersion in good agreement with observations of Milky Way clouds. The driving parameter (b) for the turbulence within each cloud is characterised by the ratio of the density contrast (sigma_rho) to the average Mach number (Mach) within the cloud, b = sigma_rho/Mach. As shown in previous works, b ~ 1/3 indicates solenoidal (divergence-free) driving and b ~ 1 indicates compressive (curl-free) driving. We find that the average b value of all the clouds formed in the simulations has a lower limit of b > 0.2. Importantly, we find that b has a broad distribution, covering values from purely solenoidal to purely compressive driving. Tracking the evolution of individual clouds reveals that the b value for each cloud does not vary significantly over their lifetime. Finally, we perform a resolution study with minimum cell sizes of 8, 4, 2 and 1 pc and find that the average b value increases with increasing resolution. Therefore, we conclude that our measured b values are strictly lower limits and that a resolution better than 1 pc is required for convergence. However, regardless of the resolution, we find that b varies by factors of a few in all cases, which means that the effective driving mode alters significantly from cloud to cloud.Comment: 12 pages, 11 figures, accepted for publication in MNRAS, more info: https://www.mso.anu.edu.au/~chfeder/pubs/turb_driv_gal/turb_driv_gal.htm

Magnetism and half-metallicity at the O surfaces of ceramic oxides

The occurence of spin-polarization at ZrO$_{2}$, Al$_{2}$O$_{3}$ and MgO surfaces is proved by means of \textit{ab-initio} calculations within the density functional theory. Large spin moments, as high as 1.56 $\mu_B$, develop at O-ended polar terminations, transforming the non-magnetic insulator into a half-metal. The magnetic moments mainly reside in the surface oxygen atoms and their origin is related to the existence of $2p$ holes of well-defined spin polarization at the valence band of the ionic oxide. The direct relation between magnetization and local loss of donor charge makes possible to extend the magnetization mechanism beyond surface properties

Narrating self-identity in bisexual motherhood

Our qualitative study investigated the ways in which bisexual mothers came to identify as such and how their identity interconnected with their personal relationship and parenting histories within the social contexts they experienced. Eight women (ages 28 to 56 years old) who had experienced sexual relationships with both women and men over their life span were interviewed. At the time of their interview the participants were mothers to children of various ages from infancy to adulthood. A Labovian narrative analysis was conducted to highlight key points in their understanding of their sense of self in relation to particular social contexts and their story of how they came to identify as a bisexual mother or not. Our findings pointed to involvement in various self-identity projects that were variously integrated and resolved within their life course story, namely, the construction of a positive sexual identity and the development of a romantic relationship and the desire to parent. Our life course development study emphasized sexual self-identity as providing a source of agency and organization with respect to personal development in embracing or sidelining opportunities as these occurred or did not occur within changing social contexts over time