Lunar dust characterization by polarimetric signature. I. Negative polarization branch of sphere aggregates of various porosities

Context. In support of NASA's exploration program and the return to the Moon, the polarimetric signature of dispersed individual Lunar regolith dust grains is studied to enable the characterization of the dust exopsheric environment by remote, in-situ, and standoff sensing. Aims. We explore the value of the negative polarization branch (NPB) as a signature for characterizing individual grains to determine if it can be used in the same way as for surfaces of planets and atmosphereless bodies. Results. Calculations show that polarization phase curves for spherical grains exhibit a sharp transition over a narrow range of size parameter between two distinct regimes, one typical of Rayleigh scattering and another dominated by a large NPB. The linear polarimetric signature observed for aggregates is a composite of a) the polarization induced by individual grains composing the aggregate and b) the polarization due to the aggregate as a whole dust grain. The weight of each component varies depending on the porosity of the aggregate. An NPB similar to the one observed for atmosphereless astronomical bodies is present for different ranges of the size parameter depending on the value of the porosity. It appears as a remnant of the negative branch exhibited by the single spherical grains. The sharper, narrow negative branch that is measured for some granular surfaces in the laboratory or seen in astronomical observations is not observed here.Comment: 7 pages, 8 figures, accepted for publication in Astronomy & Astrophysic

The learning styles neuromyth:when the same term means different things to different teachers

Alexia Barrable - ORCID: 0000-0002-5352-8330 https://orcid.org/0000-0002-5352-8330Although learning styles (LS) have been recognised as a neuromyth, they remain a virtual truism within education. A point of concern is that the term LS has been used within theories that describe them using completely different notions and categorisations. This is the first empirical study to investigate education professionals’ conceptualisation, as well as means of identifying and implementing LS in their classroom. A sample of 123 education professionals were administered a questionnaire consisting both closed- and open-ended questions. Responses were analysed using thematic analysis. LS were found to be mainly conceptualised within the Visual-Auditory-(Reading)-Kinaesthetic (VAK/VARK) framework, as well as Gardner’s multiple intelligences. Moreover, a lot of education professionals confused theories of learning (e.g., behavioural or cognitive theories) with LS. In terms of identifying LS, educators reported using a variety of methods, spanning from observation and everyday contact to the use of tests. The ways LS were implemented in the classroom were numerous, comprising various teaching aids, participatory techniques and motor activities. Overall, we argue that the extended use of the term LS gives the illusion of a consensus amongst educators, when a closer examination reveals that the term LS is conceptualised, identified and implemented idiosyncratically by different individuals. This study aims to be of use to pre-service and in-service teacher educators in their effort to debunk the neuromyth of LS and replace it with evidence-based practices.https://doi.org/10.1007/s10212-020-00485-236pubpub

An international, multicentre evaluation and description of Burkholderia pseudomallei infection in cystic fibrosis

Several cases of Burkholderia pseudomallei infection in CF have been previously reported. We aimed to identify all cases globally, risk factors for acquisition, clinical consequences, and optimal treatment strategies.We performed a literature search to identify all published cases of B. pseudomallei infection in CF. In addition we hand-searched respiratory journals, and contacted experts in infectious diseases and CF around the world. Supervising clinicians for identified cases were contacted and contemporaneous clinical data was requested.25 culture-confirmed cases were identified. The median age at acquisition was 21 years, mean FEV1 % predicted was 60 %, and mean BMI was 19.5 kg/m(2). The location of acquisition was northern Australia or south-east Asia for most. 19 patients (76 %) developed chronic infection, which was usually associated with clinical decline. Successful eradication strategies included a minimum of two weeks of intravenous ceftazidime, followed by a consolidation phase with trimethoprim/sulfamethoxazole, and this resulted in a higher chance of success when instituted early. Three cases of lung transplantation have been recorded in the setting of chronic B. pseudomallei infection.Chronic carriage of B. pseudomallei in patients with CF appears common after infection, in contrast to the non-CF population. This is often associated with an accelerated clinical decline. Lung transplantation has been performed in select cases of chronic B. pseudomallei infection.James B. Geake, David W. Reid, Bart J. Currie, Scott C. Bell, and MelioidCF Investigator

Research On and Activities For Mathematically Gifted Students

This Topical Survey offers a brief overview of the current state of research on and activities for mathematically gifted students around the world. This is of interest to a broad readership, including educational researchers, research mathematicians, mathematics teachers, teacher educators, curriculum designers, doctoral students, and other stakeholders. It first discusses research concerning the nature of mathematical giftedness, including theoretical frameworks and methodologies that are helpful in identifying and/or creating mathematically gifted students, which is described in this section. It also focuses on research on and the development of mathematical talent and innovation in students, including connections between cognitive, social and affective aspects of mathematically gifted students. Exemplary teaching and learning practices, curricula and a variety of programs that contribute to the development of mathematical talent, gifts, and passion are described as well as the pedagogy and mathematics content suitable for educating pre-service and in-service teachers of mathematically gifted students. The final section provides a brief summary of the paper along with suggestions for the research, activities, and resources that should be available to support mathematically gifted students and their teachers, parents, and other stakeholders

Malignant cerebellar ganglioglioma

We present a 62-year-old man with a high-grade cerebellar ganglioglioma with ataxia. Gangliogliomas are rare tumours which usually occur in the first 3 decades of life. There have only been a small number of grade IV gangliogliomas reported in the literature.Marguerite Harding, Brian Brophy and Timothy Geak

Idiosyncratic reactions are the most common cause of abnormal liver function tests in patients with cystic fibrosis

Background: Beta-lactam antibiotic-related liver enzyme derangement can limit treatment options for infective exacerbations in cystic fibrosis (CF) bronchiectasis. Aim: To identify risk factors for elevated liver function tests (LFT) in CF patients receiving parenteral antibiotics. Methods: All patients attending The Prince Charles Hospital (TPCH) Adult CF Centre in 2012 were identified using the CF Research Database and CF Data Registry. Biochemistry and haematology panels between 1 January 2012 and 31 December 2012 for each patient were retrieved from Queensland Health Pathology and private pathology providers. Patients with LFT more than three times the upper limit of normal were identified. For each laboratory test, concurrently administered antibiotic(s) were analysed from TPCH pharmacy dispensing system for patients who received intravenous (IV) antibiotic treatment. Results: Abnormal liver enzymes were evident in significantly more patients receiving IV antibiotics than patients who did not (43% vs 18%, P < 0.001). Pre-existing CF-related liver disease and total IV antibiotic treatment days were not associated with abnormal LFT. Higher C-reactive protein and peripheral eosinophil counts were not more common in patients with abnormal LFT. Male sex, poorer lung function and lower leucocyte counts were associated with abnormal LFT; however, these variables only explained 4.2% of the variance in the multivariable logistic model. Conclusion: Elevated LFT are common during IV antibiotic treatment in CF. Although specific antibiotic exposure may contribute to abnormal LFT in a minority of cases, our study demonstrates that antibiotic-induced liver injury is largely idiosyncratic and unpredictable