Ancient diversification in extreme environments: Exploring the historical biogeography of the Antarctic winged midge Parochlus steinenii (Diptera: Chironomidae)

The terrestrial fauna of Antarctica consists of a limited number of species, notably insects, small crustaceans and other micro-invertebrates. Over long periods of evolutionary isolation, these organisms have developed varying degrees of tolerance to multifaceted environmental stresses. Recent molecular biogeographical research highlights the enduring persistence of much of Antarctica's current terrestrial fauna, with estimates spanning from hundreds of thousands to millions of years. Parochlus steinenii, commonly known as the Antarctic winged midge, stands out as one of the only two insect species native to Antarctica. Distributed across three biogeographic regions, southern South America and the Falkland/Malvinas Islands, sub-Antarctic South Georgia and the Maritime Antarctic South Shetland Islands, this midge raises questions about the temporal isolation of its populations and their divergence. Employing mitochondrial and nuclear genetic markers, we conducted phylogeographic and demographic analyses on 151 individuals of P. steinenii obtained across the three main biogeographic regions including the Magellanic sub-Antarctic Ecoregion (MSE) of southern South America, the sub-Antarctic Island of South Georgia (SG) and the South Shetland Islands (SSI) within the Maritime Antarctic (MA). Our data support the diversification of P. steinenii during the mid-Pleistocene around 1.46 Mya. This period included a branching event between a clade containing only specimens from the MSE and a clade containing individuals from a broader range of locations including the SSI and SG. Based on intraspecific phylogeographic and demographic inferences, we detected strong evolutionary divergence between the three main biogeographic regions. We also detected a signal of population growth during the deglaciation process in SSI and SG, contrary to the pattern seen in the MSE. The different demographic and phylogeographic histories between the sampled biogeographic regions could result from the MA and SG experiencing a strong genetic bottleneck due to a reduction in population size during the Last Glacial Maximum, while the MSE maintained a significant effective population size. The high level of divergence detected between individuals from the MSE and the remaining biogeographic regions supports the hypothesis of a speciation process taking place in P. steinenii

Liquid-crystal enabled electrophoresis: Scenarios for driving and reconfigurable assembling of colloids

We demonstrate several examples of driving and steering of colloids when dispersed in nematic liquid crystals. The driving mechanism is based on the principle of nonlinear electrophoresis which is mediated by the asymmetry in the structure of the defects that the inclusions generate in the host elastic matrix. The steering mechanism originates in the photoactivation of the anchoring conditions of the nematic liquid crystal on one of the enclosing plates. As experimental realizations we first review a scenario of water microdroplets being phoretically transported for cargo release and chemical reaction. Steering is illustrated in terms of the reconfigurable assembly of colloidal particles, either in the form of asters or rotating-mills, commanded by predesigned patterns of illumination

Postgraduate students learning about research: exploring the attitudes of social work and mental health students in an English university setting.

We discuss an ongoing pedagogic initiative and research project exploring how postgraduates undertaking social work or mental health educational programmes in one UK university since 2007 responded to learning about research methods during a year-long module. Few studies have looked specifically at postgraduate students’ attitudes towards research / research methods although previous work considered undergraduate students’ attitudes or research methods training for social work or health studies students. We note from previous research that students may express anxiety when learning about research, particularly quantitative methods. Using an existing validated rating scale with 5 subscales (Papanastasiou, 2005), we explored student attitudes prior to taking a research module and the possible significance of gender, professional group and status on course (college or employment based). We report initial findings from two student cohorts (2007-8 & 2008-9) comprising 105 social work + dual diagnosis (mental health) masters students. Project data was then used by students to complete a quantitative assignment as part of module assessment. Results showed these students had a ‘positive’ attitude towards research pre-module; this was generally maintained but did not increase post-module. Student cohorts were rated as having overall research ‘anxiety’ pre-module; this lessened post-module although the change was not statistically significant. A significant change (decrease) in ‘usefulness to career’ subscale was recorded post-module. We consider the factors that could have impacted on these research findings such as reduced follow up sample sizes ; but report how combining a pedagogic initiative with a research project offers opportunities to explore this complex area in more depth and with positive outcomes for student learning