Genetic Bottlenecks In \u3ci\u3ePristis\u3c/i\u3e Sawfishes In Northern Australian Waters

Northern Australia has been identified as the last stronghold for the dwarf sawfish Pristis clavata, green sawfish P. zijsron, and largetooth sawfish P. pristis, making these populations key in global conservation efforts for each species. This research assesses the levels of genetic diversity in these 3 sawfishes in Australian waters, testing for the presence of population bottlenecks using data at microsatellite loci. Levels of observed heterozygosity in each species from the west coast of Australia and the north-eastern Gulf of Carpentaria were generally high. M ratio tests suggest that assemblages of P. zijsron and P. pristis on the west coast and P. clavata and P. zijsron in the Gulf of Carpentaria may have experienced population bottlenecks. The bottlenecks are especially pronounced in P. zijsron populations and in P. clavatafrom the Gulf of Carpentaria. Demographic analyses, based on mtDNA data, indicate relatively recent (evolutionarily) range expansions in Pristis sawfishes in northern Australian waters, which could account for the population bottlenecks. A more recent range expansion in each of P. clavata and P. zijsron, as evidenced by more recent population divergence and more recent/higher rates of historic maternal gene flow, could account for the more pronounced bottlenecks in these species when compared to P. pristis. Given that Pristis sawfishes in Australian waters have experienced population bottlenecks, whether they be historic, contemporary or both, the preservation of remaining genetic diversity should be a high conservation priority

Barriers and enablers to learning during team-based clinical simulations: reflective interviews with final year undergraduate nursing students

Background: Contemporary approaches to clinical simulation can enhance educational outcomes. However, simulation approaches do have limitations with possible compromises for learning and teaching. This paper aims to identify barriersand enablers to learning in simulated clinical settings.Methods: A generic qualitative design was applied. Semi-structured group video debriefing interviews were held with Australian final-year nursing students who completed three patient deterioration scenarios with a standardized patient.Audio-recorded interviews were transcribed and analysed to identify emergent themes.Results: Interviews with 15 teams of three students (n = 45) from three universities were analysed. Learning enablers were ‘Realism of the simulated environment’; ‘Practicing: we should do this at uni’; ‘Learning from reflection and expert feedback’, and ‘How to become competent: know the gaps’. Barriers to learning included ‘Increased stress from inexperience; ‘Expectations when pretending’ and ‘Lack of assistance’. Skills practice in team-based settings with applicable reflection and debriefing was regarded as beneficial. Simulated patients enhanced fidelity but were unable to replicate actual clinical signs. High stress levels were perceived as a barrier to learning.Conclusions: Applicably designed high fidelity simulations with video-based reflective review offer repeated rehearsal of clinical situations to enable learning. This educational strategy may reduce the time it takes undergraduate students toreach competency

Evolution of the Near-Infrared Tully-Fisher Relation: Constraints on the Relationship Between the Stellar and Total Masses of Disk Galaxies since z=1

Using a combination of Keck spectroscopy and near-infrared imaging, we investigate the K-band and stellar mass Tully-Fisher relation for 101 disk galaxies at 0.2 < z < 1.2, with the goal of placing the first observational constraints on the assembly history of halo and stellar mass. Our main result is a lack of evolution in either the K-band or stellar mass Tully-Fisher relation from z = 0 - 1.2. Furthermore, although our sample is not statistically complete, we consider it suitable for an initial investigation of how the fraction of total mass that has condensed into stars is distributed with both redshift and total halo mass. We calculate stellar masses from optical and near-infrared photometry and total masses from maximum rotational velocities and disk scale lengths, utilizing a range of model relationships derived analytically and from simulations. We find that the stellar/total mass distribution and stellar-mass Tully-Fisher relation for z > 0.7 disks is similar to that at lower redshift, suggesting that baryonic mass is accreted by disks along with dark matter at z < 1, and that disk galaxy formation at z < 1 is hierarchical in nature. We briefly discuss the evolutionary trends expected in conventional structure formation models and the implications of extending such a study to much larger samples.Comment: ApJ, in press, 9 page

The Magnitude-Size Relation of Galaxies out to z ~ 1

As part of the Deep Extragalactic Evolutionary Probe (DEEP) survey, a sample of 190 field galaxies (I_{814} <= 23.5) in the ``Groth Survey Strip'' has been used to analyze the magnitude-size relation over the range 0.1 < z < 1.1. The survey is statistically complete to this magnitude limit. All galaxies have photometric structural parameters, including bulge fractions (B/T), from Hubble Space Telescope images, and spectroscopic redshifts from the Keck Telescope. The analysis includes a determination of the survey selection function in the magnitude-size plane as a function of redshift, which mainly drops faint galaxies at large distances. Our results suggest that selection effects play a very important role. A first analysis treats disk-dominated galaxies with B/T < 0.5. If selection effects are ignored, the mean disk surface brightness (averaged over all galaxies) increases by ~1.3 mag from z = 0.1 to 0.9. However, most of this change is plausibly due to comparing low luminosity galaxies in nearby redshift bins to high luminosity galaxies in distant bins. If this effect is allowed for, no discernible evolution remains in the disk surface brightness of bright (M_B < -19) disk-dominated galaxies. A second analysis treats all galaxies by substituting half-light radius for disk scale length, with similar conclusions. Indeed, at all redshifts, the bulk of galaxies is consistent with the magnitude-size envelope of local galaxies, i.e., with little or no evolution in surface brightness. In the two highest redshift bins (z > 0.7), a handful of luminous, high surface brightness galaxies appears that occupies a region of the magnitude-size plane rarely populated by local galaxies. Their wide range of colors and bulge fractions points to a variety of possible origins.Comment: 19 pages, 12 figures. Accepted for publication in the Astrophysical Journa

Expert in my pocket: creating first person POV videos to enhance mobile learning

Worldwide, there has been a rapid increase in both the use of mobile technologies as a conduit for student learning and the use of wearable cameras to record sporting and recreational activities. The Expert in My Pocket project (EiMP) has combined these two technologies to produce a repository of freely available short videos and supporting materials to enhance student development of psychomotor clinical skills. The videos are presented from a first person point of view (1PPOV) with expert health professionals &lsquo;thinking aloud&rsquo; as they demonstrate selected skills. Research indicates that students and educators overwhelmingly support the concept of EiMP videos and more importantly value the 1PPOV as an authentic view. This paper demonstrates the techniques and equipment employed to produce these videos, which consisted of a chest or head mounted GoPro camera operated via an iPad. Additionally, the paper explains another innovative feature, Quick Response (QR) Codes, that when linked to the videos placed on equipment assists with &ldquo;just in time&rdquo; mobile learning