Building reflective practices in a pre-service math and science teacher education course that focuses on qualitative video analysis

The use of video for in-service and pre-service teacher development has been gaining acceptance, and yet video remains a challenging and understudied tool. Many projects have used video to help pre-service and in-service teachers reflect on their own teaching processes, examine teacher–student interactions, and develop their professional vision. But rarely has video been used in ways more akin to qualitative education research that is focused on student learning. Even more rarely has this focus occurred at the earliest stages of pre-service teaching when students have not yet decided to pursue teaching careers. Yet here we argue that there are benefits to our approach. We examine a course for prospective pre-service math and science teachers at the University of California, Berkeley, that engages participants in qualitative video analysis to foster their reflective practice. This course is unique in that the prospective pre-service teachers engage in qualitative video analysis at a level characteristic of professional educational research, in that their analysis focuses on student learning of math and science content. We describe classroom activities that provide opportunities for the preservice teacher participants to better observe, notice, and interpret their students’ sociocognitive activity. The course culmination project involves participants developing and teaching lessons in a high school classroom. The participants then videotape the lessons and conduct qualitative video analysis. Results include detailed examples of two selected prospective pre-service teachers demonstrating coherent and effective approaches to conceptualizing the learning and teaching of mathematical and science content along with some potential design principles for building reflective practices through qualitative video projects. © 2018 Association for Science Teacher Education

Geometry and electronic structure of iridium adsorbed on graphene

We report investigation of the geometry and electronic structure of iridium atoms adsorbed onto graphene through a combined experimental and theoretical study. Ir atoms were deposited onto a flake of graphene on a Pt(111) surface and found to form clusters even at low temperatures. The areal density of the observed clusters on the graphene flake suggests the clusters are most likely pairs of Ir atoms. Theoretical ab initio density functional (DFT) calculations indicate that these Ir dimers are oriented horizontally, near neighboring "bridge" sites of the graphene lattice, as this configuration has the strongest adsorption energy of all high-symmetry configurations for the Ir dimer. A large peak in the local density of states (LDOS) at the Dirac point energy was measured via scanning tunneling spectroscopy, and this result is reproduced by a DFT calculation of the LDOS. The peak at the Dirac point energy is found to be from the Ir s and p states. The LDOS in the monomer case was also calculated, and is found to significantly differ from the experimentally determined data, further supporting the hypothesis of low-temperature clustering

Progressive multiple sclerosis: Prospects for disease therapy, repair, and restoration of function

Multiple sclerosis is a major cause of neurological disability, which accrues predominantly during progressive forms of the disease. Although development of multifocal inflammatory lesions is the underlying pathological process in relapsing-remitting multiple sclerosis, the gradual accumulation of disability that characterises progressive multiple sclerosis seems to result more from diffuse immune mechanisms and neurodegeneration. As a result, the 14 anti-inflammatory drugs that have regulatory approval for treatment of relapsing-remitting multiple sclerosis have little or no efficacy in progressive multiple sclerosis without inflammatory lesion activity. Effective therapies for progressive multiple sclerosis that prevent worsening, reverse damage, and restore function are a major unmet need. In this Series paper we summarise the current status of therapy for progressive multiple sclerosis and outline prospects for the future

Sydney particle characterisation study PM2.5 source apportionment in the Sydney Region between 2000 and 2014

The Australian Nuclear Science and Technology Organisation (ANSTO) has been applying accelerator based nuclear techniques to the characterisation of fine PM2.5 ambient air pollution since the early 1990s. Over the decades large long-term databases have been acquired at dozens of sites both in Australia and internationally on the PM2.5 mass together with over 23 different elemental and chemical species that make up this fine particle pollution. In this study we used data previously collected by ANSTO from four of our long-term sampling sites covering the period from 1 January 2000 to 31 December 2014. Positive matrix factorisation (PMF) source apportionment techniques were applied to this data to identify seven different source components or fingerprints that make up the measured total PM2.5mass at each of these four sites. The primary aim of this study was to: convert the existing 15-year PM2.5 mass and elemental datasets for four given sites in the Sydney basin into identifiable source fingerprints quantify the absolute and the percentage contribution of each of these fingerprints to the total fine PM2.5 mass provide seasonal and annual variations for each of the source fingerprints provide a readily accessible database containing the daily source fingerprints and their contributions covering the 15-year period from 2000–2014 for four given sites in the Sydney basin if possible, identify and quantify the major contributors of fine particle pollution to the ambient air quality in Sydney. Typically fine particles were collected over 24-hour periods twice a week (104 filters per year) at Lucas Heights, Richmond, Mascot and Liverpool sites over a 15-year period from 2000 to 2014. In all, around 6000 sampling days are represented by this study. Each of these filters was analysed for the 23 elemental and chemical species: hydrogen (H), sodium (Na), al uminium (Al), silicon (Si), phosphorous (P), sulfur (S), chlorine (Cl), potassium (K), calcium (Ca), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), selenium (Se), bromium (Br), lead (Pb), bl ack carbon (BC) and total nitrogen (TotN) to concentrations down to 1ngm–3 of air sampled. TotN is the total nitrogen from ammonium and nitrate ions. © 2016 ANST

Can IBA techniques quantify the contributions of deserts, winter domestic heating and coal fired power stations to the ambient fine particle air pollution concentrations in the Sydney Basin?

ANSTO has used accelerator based ion beam analysis (IBA) techniques to characterise, fingerprint and source fine particles in and around Australia since the early 1990's. This large database covering many years allows us to now look quantitatively at fine particle sources, including automobiles, smoke, sea spray, soils and industrial emissions. This talk will discuss the accelerator based IBA techniques and how they are used to identify the contributions of windblown soils, wood heating and coal fired power stations to ambient air pollution in the Sydney Basin between 1998 and the present

Long term fine aerosols at the Cape Grim global baseline station: 1998 to 2016

Fine aerosol measurements have been undertaken at the Cape Grim global baseline station since 1992. Ion beam analysis techniques were then used to determine the elemental composition of the samples from which source fingerprints can be determined. In this study six source fingerprints were identified to contribute to the measurements of PM2.5 at Cape Grim (from 1998 to 2016); fresh sea salt (57%), secondary sulfate and nitrates (14%), smoke (13%), aged sea salt (the product of NaCl reactions with SO2; 12%), soil dust (2.4%) and industrial metals (1.5%). Back trajectory analysis showed that local Tasmanian sources of soil dust contributed to the high soil dust measurements. High measurements of secondary aerosols were recorded when air masses were arriving from the Australian mainland, in the direction of the Victorian power stations. When air masses were arriving from the baseline sector, the maximum concentration of aged sea salt was 1.3 μg/m3, compared to overall maximum of 4.9 μg/m3. For secondary sulfates and nitrates the maximum concentrations were 2.5 and 7.5 μg/m3 from the baseline sector and overall, respectively. While measurements at Cape Grim can be affected from long range transport from mainland Australia and some local Tasmanian sources, the average concentrations of anthropogenic sources are still considerably lower than those measured at more populated areas. For example, at Lucas Heights (located south-west of the Sydney central business district, with little local sources) the average concentrations of secondary sulfates/nitrates and aged sea air were 1.4 and 1.0 μg/m3, respectively; compared to average concentrations of 0.8 and 0.6 μg/m3, at Cape Grim. The average concentrations of smoke were compatible at the two sites. The impact of primary aerosols from vehicle exhaust at Cape Grim was limited and no corresponding fingerprint was resolved.Crown Copyright © 2017 Published by Elsevier Lt

Kinetic profiling of therapeutic strategies for inhibiting the formation of amyloid oligomers

Protein self-assembly into amyloid fibrils underlies several neurodegenerative conditions, including Alzheimer's and Parkinson's diseases. It has become apparent that the small oligomers formed during this process constitute neurotoxic molecular species associated with amyloid aggregation. Targeting the formation of oligomers represents therefore a possible therapeutic avenue to combat these diseases. However, it remains challenging to establish which microscopic steps should be targeted to suppress most effectively the generation of oligomeric aggregates. Recently, we have developed a kinetic model of oligomer dynamics during amyloid aggregation. Here, we use this approach to derive explicit scaling relationships that reveal how key features of the time evolution of oligomers, including oligomer peak concentration and life-time, are controlled by the different rate parameters. We discuss the therapeutic implications of our framework by predicting changes in oligomer concentrations when the rates of the individual microscopic events are varied. Our results identify the kinetic parameters that control most effectively the generation of oligomers, thus opening the way for the systematic rational design of therapeutic strategies against amyloid-related diseases

Observations of total RONO2 over the boreal forest: NO x sinks and HNO3 sources

In contrast with the textbook view of remote chemistry where HNO 3 formation is the primary sink of nitrogen oxides, recent theoretical analyses show that formation of RONO2 (ΣANs) from isoprene and other terpene precursors is the primary net chemical loss of nitrogen oxides over the remote continents where the concentration of nitrogen oxides is low. This then increases the prominence of questions concerning the chemical lifetime and ultimate fate of ΣANs. We present observations of nitrogen oxides and organic molecules collected over the Canadian boreal forest during the summer which show that ΣANs account for ∼20% of total oxidized nitrogen and that their instantaneous production rate is larger than that of HNO3. This confirms the primary role of reactions producing ΣANs as a control over the lifetime of NOx (NOx =NO+NO2) in remote, continental environments. However, HNO 3 is generally present in larger concentrations than ΣANs indicating that the atmospheric lifetime of ΣANs is shorter than the HNO3 lifetime. We in-vestigate a range of proposed loss mechanisms that would explain the inferred lifetime of ΣANs finding that in combination with deposition, two processes are consistent with the observations: (1) rapid ozonolysis of isoprene nitrates where at least ∼40% of the ozonolysis producs t ts release NOx from the carbon backbone and/or (2) hydrolysis of particulate organic nitrates with HNO3 as a product. Implications of these ideas for our understanding of NOx and NOy budget in remote and rural locations are discussed. © Author(s) 2013