The effects of transcranial direct current stimulation on within- and cross-paradigm transfer following multi-session backward recall training.

Transcranial direct current stimulation (tDCS) has been shown to enhance the efficacy and generalisation of working memory (WM) training, but there has been little systematic investigation into how coupling task-specific WM training with stimulation impacts more specifically on transfer to untrained tasks. This randomised controlled trial investigated the boundary conditions to transfer by testing firstly whether the benefits of training on backward digit recall (BDR) extend to untrained backward recall tasks and n-back tasks with different materials, and secondly which, if any, form of transfer is enhanced by tDCS. Forty-eight participants were allocated to one of three conditions: BDR training with anodal (10 min, 1 mA) or sham tDCS, or visual search training with sham tDCS, applied over the left dorsolateral prefrontal cortex. Transfer was assessed on within- (backward recall with digits, letters, and spatial locations) and cross-paradigm (n-back with digits and letters) transfer tests following three sessions of training and stimulation. On-task training gains were found, with transfer to other backward span but not n-back tasks. There was little evidence that tDCS enhanced on-task training or transfer. These findings indicate that training enhances paradigm-specific processes within WM, but that tDCS does not enhance these gains

On the impact of spectral template uncertainties in synthetic stellar populations

Uncertainties in stellar population models, both in terms of stellar evolution and stellar spectra, translate into uncertainties in our interpretation of stellar populations in galaxies, since stars are the source of most of the light we receive from them. Observations by JWST are revealing high-redshift galaxies in great detail, which must then be compared to models. One significant source of uncertainty is in the stellar spectra used to generate composite spectra of stellar populations, which are then compared to data. Confidence in theoretical models is important to enable reliable determination of the properties of these galaxies such as their ages and star formation history. Here we present a comparison of spectral synthesis carried out with 6 different stellar spectral libraries using the Binary Population and Spectral Synthesis (bpass) framework. In photometric colours, the differences between theoretical libraries are relatively small (<0.10 mag), similar to typical observational uncertainties on individual galaxy observations. Differences become more pronounced when detailed spectroscopic properties are examined. Predictions for spectral line indices can vary significantly, with equivalent widths differing by a factor of two in some cases. With these index strengths, some of the libraries yield predictions of ages and metallicities which are unphysical. Many spectral libraries lack wavelength coverage in the ultraviolet, which is of growing importance in the era of JWST observations of distant galaxies, whose flux is dominated by hot, young stars

Markers of success: A study of twins' instructed second language acquisition

We examined the association between proficiency in instructed second language acquisition (ISLA) and previous bilingualism, starting age of ISLA, language anxiety and attitude. The analyses were conducted on 564 adolescent Australian twins. Additionally, by examining discrepancies within approximately 100 pairs of monozygotic twins, we sought to specifically identify the environmental effects related to attitude and anxiety on achievement (i.e. with genetic effects removed). We found a clear relationship between attitude towards language learning and proficiency in the second language. Furthermore, the analyses on the monozygotic twins point to the possibility that higher language anxiety is associated with higher proficiency. On the other hand, bilingualism and starting age of ISLA appear to be unrelated to proficiency in the language being learned.</p

Binary evolution pathways of blue large-amplitude pulsators

Blue Large-Amplitude Pulsators (BLAPs) are a recently discovered class of pulsating star, believed to be proto-white dwarfs, produced by mass stripping of a red giant when it has a small helium core. An outstanding question is why the stars in this class of pulsator seem to form two distinct groups by surface gravity, despite predictions that stars in the gap between them should also pulsate. We use a binary population synthesis model to identify potential evolutionary pathways that a star can take to become a BLAP. We find that BLAPs can be produced either through common envelope evolution or Roche lobe overflow, with a Main Sequence star or an evolved compact object being responsible for the envelope stripping. The mass distribution of the inferred population indicates that fewer stars would be expected in the range of masses intermediate to the two known groups of pulsators, suggesting that the lack of observational discoveries in this region may be a result of the underlying population of pre-white dwarf stars. We also consider metallicity variation and find evidence that BLAPs at Z = 0.010 (half-Solar) would be pulsationally unstable and may also be more common. Based on this analysis, we expect the Milky Way to host around 12000 BLAPs and we predict the number density of sources expected in future observations such as the Legacy Survey of Space and Time at the Vera Rubin Observatory

The Etiology of Individual Differences in Second Language Acquisition in Australian School Students: A Behavior‐Genetic Study

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93553/1/j.1467-9922.2012.00718.x.pd

Models of school breakfast program implementation in Western Australia and the implications for supporting disadvantaged students

A substantial body of literature points to the educational and social benefits of school breakfast programs. Most high-income countries provide free or subsidized school breakfasts to support disadvantaged children. Australia does not have a nationally-funded school meal program. Instead, charitable organizations offer school breakfast programs on a voluntary basis, often with funding support from state/territory governments. Decisions about participating in a school breakfast program (SBP), which students to support, and the degree of integration with other strategies to support disadvantaged students are made at the school level. This large-scale, multi-year study examined models of SBP implementation in Western Australian (WA) schools and stakeholder perceptions of the impact of SBPs at the classroom and whole school level. Findings indicate that the approaches adopted by WA schools reflect the extent to which SBPs are part of an integrated approach to supporting disadvantaged students. Minimalist approaches were evident where the focus was limited to alleviating hunger. More inclusive, resource‐intensive models were apparent where the SBP was positioned within a whole school approach to student wellbeing and/or community capacity-building. All schools reported benefits for disadvantaged students, however, the social benefits of SBPs that manifested at the classroom and whole school level were more pronounced in schools that had adopted more integrated, whole school approaches. The findings have implications for Australian schools and other countries that seek to optimize the role of SBPs to provide more holistic support for vulnerable students and reduce the impact of social and economic disadvantage

Educational interventions involving physical manipulatives for improving children's learning and development: A scoping review

Physical manipulatives (PMs) are concrete objects used during hands-on learning activities (e.g., building blocks, fraction tiles, counters), and are widely used in primary-school teaching, especially during maths instruction. This scoping review collated studies that have examined the effectiveness of educational PM interventions with pre-primary and primary-age children. A total of 102 studies met the inclusion criteria and were synthesised in the review. Most studies included a sample of children aged 4–6 years and were conducted in a school setting. They spanned 26 different countries, but almost all took place in high- or middle-income contexts, mainly in the USA. Interventions were grouped into three main learning domains: maths, literacy and science. Considerable heterogeneity was identified across the review studies in terms of the PMs and hands-on activities used (e.g., block building, shape sorting, paper folding, enactment with figurines). Evidence relating to effectiveness of the intervention programmes was synthesised, with the most promising findings identified in the maths domain. Benefits to children's spatial, literacy and science skills were also reported. Overall, however, the evidence was mixed: other studies found that PMs were not associated with learning benefits, and many were hindered by methodological shortcomings. This calls for caution when drawing conclusions about the overall effectiveness of PM interventions. Nevertheless, the findings illustrate the many ways hands-on PM activities can be incorporated into children's early learning experiences. Recommendations for further research and for using PMs in practice are made

Genomic Scans across Three Eucalypts Suggest that Adaptation to Aridity is a Genome-Wide Phenomenon

Widespread species spanning strong environmental (e.g., climatic) gradients frequently display morphological and physiological adaptations to local conditions. Some adaptations are common to different species that occupy similar environments. However, the genomic architecture underlying such convergent traits may not be the same between species. Using genomic data from previous studies of three widespread eucalypt species that grow along rainfall gradients in southern Australia, our probabilistic approach provides evidence that adaptation to aridity is a genome-wide phenomenon, likely to involve multiple and diverse genes, gene families and regulatory regions that affect a multitude of complex genetic and biochemical processes

Iron Isotope Fractionation during Fe(II) Oxidation Mediated by the Oxygen-Producing Marine Cyanobacterium Synechococcus PCC 7002

In this study, we couple iron isotope analysis to microscopic and mineralogical investigation of iron speciation during circumneutral Fe(II) oxidation and Fe(III) precipitation with photosynthetically produced oxygen. In the presence of the cyanobacterium Synechococcus PCC 7002, aqueous Fe(II) (Fe(II)aq) is oxidized and precipitated as amorphous Fe(III) oxyhydroxide minerals (iron precipitates, Feppt), with distinct isotopic fractionation (ε56Fe) values determined from fitting the δ56Fe(II)aq (1.79‰ and 2.15‰) and the δ56Feppt (2.44‰ and 2.98‰) data trends from two replicate experiments. Additional Fe(II) and Fe(III) phases were detected using microscopy and chemical extractions and likely represent Fe(II) and Fe(III) sorbed to minerals and cells. The iron desorbed with sodium acetate (FeNaAc) yielded heavier δ56Fe compositions than Fe(II)aq. Modeling of the fractionation during Fe(III) sorption to cells and Fe(II) sorption to Feppt, combined with equilibration of sorbed iron and with Fe(II)aq using published fractionation factors, is consistent with our resulting δ56FeNaAc. The δ56Feppt data trend is inconsistent with complete equilibrium exchange with Fe(II)aq. Because of this and our detection of microbially excreted organics (e.g., exopolysaccharides) coating Feppt in our microscopic analysis, we suggest that electron and atom exchange is partially suppressed in this system by biologically produced organics. These results indicate that cyanobacteria influence the fate and composition of iron in sunlit environments via their role in Fe(II) oxidation through O2 production, the capacity of their cell surfaces to sorb iron, and the interaction of secreted organics with Fe(III) minerals

The dependence of theoretical synthetic spectra on α-enhancement in young, binary stellar populations

The enhancement of α elements such as oxygen is an important phase in the chemical evolution of the early Universe, with nebular material becoming enriched in these elements sooner than iron. Here, we present models which incorporate stellar spectra with α-enhanced compositions, focusing on the impact on the integrated light of young stellar populations, including those with large binary star fractions using the Binary Populations and Spectral Synthesis (BPASS) framework, while using Solar-scaled stellar evolution models. We find that broad spectrum outputs such as production of ionizing flux, the ultraviolet spectral slope and optical colours are only weakly affected by a change i