530 research outputs found
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Trajectories of learning across museums and classrooms
This paper explores the use of social and mobile technologies on school field trips as means of enhancing the visitor experience. It employs the notion of a ‘trajectory’ (Ludvigsen et al. 2010; Pierroux et al., 2010; Littleton & Kerawalla, 2012) as appropriate means of connecting learners temporal experiences with informal and formal learning contexts. The focus of the analysis is on a group’s trajectory with an aim to examine the meanings made and represented in multimodal ‘ensembles’ and further, to explore whether artefacts and tools encountered or used inform students’ ensembles and assist them in making connections across the settings. This paper aims to contribute to contemporary discourse on technology-enhanced museum learning by exploring aspects of the visitor experience, such as meaning making across and between contexts
Parents of Children with Learning Disabilities: Attitudes Toward Education
In this study, twenty parents of children with learning disabilities were surveyed to discover their attitudes toward education. The subjects were selected from those eligible and those attending a voluntary support group for parents of children with learning disabilities. It was discovered that parents react differently to the initial diagnosis of a learning disability. The data showed parents felt comfortable discussing their children\u27s progress with school officials and were willing to advocate for their children whenever necessary. However, these parents felt the school personnel needed to communicate more effectively with the parents and attempt to understand the difficulties of raising a child with a learning disability. The data also showed that these parents needed more information on their children\u27s rights, other services available, and information on support groups for parents of children with learning disabilities
Nitrogen Abundances and the Distance Moduli of the Pleiades and Hyades
Recent reanalyses of HIPPARCOS parallax data confirm a previously noted
discrepancy with the Pleiades distance modulus estimated from main-sequence
fitting in the color-magnitude diagram. One proposed explanation of this
distance modulus discrepancy is a Pleiades He abundance that is significantly
larger than the Hyades value. We suggest that, based on our theoretical and
observational understanding of Galactic chemical evolution, nitrogen abundances
may serve as a proxy for helium abundances of disk stars. Utilizing
high-resolution near-UV Keck/HIRES spectroscopy, we determine N abundances in
the Pleiades and Hyades dwarfs from NH features in the 3330 Ang region. While
our Hyades N abundances show a modest 0.2 dex trend over a 800 K Teff range, we
find the Pleiades N abundance (by number) is 0.13+/-0.05 dex lower than in the
Hyades for stars in a smaller overlapping Teff range around 6000 K; possible
systematic errors in the lower Pleiades N abundance result are estimated to be
at the <0.10 dex level. Our results indicate [N/Fe]=0 for both the Pleiades and
Hyades, consistent with the ratios exhibited by local Galactic disk field stars
in other studies. If N production is a reliable tracer of He production in the
disk, then our results suggest the Pleiades He abundance is no larger than that
in the Hyades. This finding is supported by the relative Pleiades-Hyades C, O,
and Fe abundances interpreted in the current context of Galactic chemical
evolution, and is resistant to the effects on our derived N abundances of a He
abundance difference like that needed to explain the Pleiades distance modulus
discrepancy. A physical explanation of the Pleiades distance modulus
discrepancy does not appear to be related to He abundance.Comment: Accepted for publication in the Publications of the Astronomical
Society of the Pacifi
Evaluating complex digital resources
Squires (1999) discussed the gap between HCI (Human Computer Interaction) and the educational computing communities in their very different approaches to evaluating educational software. This paper revisits that issue in the context of evaluating digital resources, focusing on two approaches to evaluation: an HCI and an educational perspective. Squires and Preece's HCI evaluation model is a predictive model ‐ it helps teachers decide whether or not to use educational software ‐ whilst our own concern is in evaluating the use of learning technologies. It is suggested that in part the different approaches of the two communities relate to the different focus that each takes: in HCI the focus is typically on development and hence usability, whilst in education the concern is with the learner and teacher use
Fundamental Capillary Electrophoresis: An Evaluation of Electrokinetic Sampling
Capillary electrophoresis has become a powerful separation technique in fields of biochemical separations, inorganic ions, and chiral separations. The technique has experienced exponential growth since the historic publication of Zone Electrophoresis in Open-Tubular Glass Capillaries by Lukacs and Jorgenson in 1981. However, the use of capillary electrophoresis as a primary research analysis tool still remains to be seen in many pharmaceutical laboratories. One of the main reasons for this is that it remains difficult to validate CE methods using the criteria of quantitation and accuracy posed by the current government regulating agencies, as developed for high performance liquid chromatography and gas chromatography methods.
This dissertation will examine the fundamental principles of capillary electrophoresis as they pertain to quantitative reproducibility of peak. areas with the primary focus on effects of electrokinetic sampling conditions. Data supporting longer sampling times and higher sampling voltages contributes to reproducibility relative standard deviation values of less the 2%. Injection plug lengths elucidated from sampling criteria are also evaluated.
Two models of predicting the injection plug length under the conditions of electrokinetic injection are contrasted. The first system employs standard electrokinetic sampling equations. The second model, developed by Otsuka and Terabe, predicts a maximum length above which a 5% variation in peak width may be observed. The combination of these models lead to the derivation of another expression describing the electrokinetic injection plug length. More accurate measurements of analyte mobility are shown through the use of this equation in a fashion similar to the graphical analysis of the standard Beer\u27s Law plot.
Five different pre-injection conditions and four different quantitation techniques are evaluated as they affect the overall separation performance of caffeine and theophylline using capillary zone electrophoresis with electrokinetic injection. When quantitation methods such as internal standardization or internal area normalization are used, preinjection rinsing conditions are irrelevant.
With a better understanding of analyte mobility, the field of capillary electrophoresis analysis may be extended to the analysis of polymetallic complexes. Polymetallic complexes are of current interest in the literature due to their complexity and wide range of potential applicability. The first isomeric compound to be studied is [Ru(tpy)CI] 2(bpmi+ (tpy = 2,2\u27:6 2 -terpyridine) (bpm = 2,2\u27-bipyrimidine). These isomers, which are of the same charge to mass ratio, were separated in approximately four minutes in a fused-silica capillary column with phosphate buffer ofpH 7.5 at an applied voltage of 20 kV followed by direct UV detection. An electrophoretic concentration step (stacking) was utilized in order to improve peak shape
In-Vivo Lipidomics using Single-Cell Raman Spectroscopy
We describe a method for direct, quantitative, in vivo lipid profiling of oil producing microalgae using single-cell laser-trapping Raman spectroscopy (LTRS). This approach is demonstrated in the quantitative determination of the degree of unsaturation and transition temperatures of constituent lipids within microalgae. These properties are important markers for determining engine compatibility and performance metrics of algal biodiesel. We show that these factors can be directly measured from a single living microalgal cell held in place with an optical trap while simultaneously collecting Raman data. Cellular response to different growth conditions is monitored in real time. Our approach circumvents the need for lipid extraction and analysis that is both slow and invasive. Furthermore, this technique yields real-time chemical information in a label-free manner, thus eliminating the limitations of impermeability, toxicity and specificity of the fluorescent probes used in other common protocols. Although the single-cell Raman spectroscopy demonstrated here is focused on the study of the microalgal lipids with biofuel applications, the analytical capability and quantitation algorithms demonstrated are applicable to many different organisms, and should prove useful for a diverse range of applications in lipidomics
Evidence-based Learning: Foundations
This chapter discusses some of the Computer Aided Learning (CAL) Research Group’s early work, focusing on our attempts to understand learners’ practices so that teaching could be adapted to meet learners’ needs. The chapter describes and discusses examples of CALRG research from the group’s early days to the start of the 2000s. One reason for doing this is to explore the extent to which there has been continuity in the group’s work over time. In the chapter we argue that the group’s motivation, aims, ethos and overall approach have remained similar during its forty-year existence. The chapter draws on the Beyond Prototypes framework, described in Chapter 1 of this book, to frame some of the discussion, in particular focusing on policy and environment. Analysis of the case studies that led to the development of the framework suggest that Technology Enhanced Learning (TEL) needs to be understood as a ‘complex’, made up of a series of elements that need to be considered together. The chapter also uses the three themes of the group’s first conference to provide an organising framework for the discussion. The three themes from that first conference are firstly, models of learning; secondly, methods for studying learning and thirdly, institutional research
Endothelial progenitor cells and burn injury - exploring the relationship.
Burn wounds result in varying degrees of soft tissue damage that are typically graded clinically. Recently a key participant in neovascularization, the endothelial progenitor cell, has been the subject of intense cardiovascular research to explore whether it can serve as a biomarker for vascular injury. In this review, we examine the identity of the endothelial progenitor cell as well as the evidence that support its role as a key responder after burn insult. While there is conflicting evidence with regards to the delta of endothelial progenitor cell mobilization and burn severity, it is clear that they play an important role in wound healing. Systematic and controlled studies are needed to clarify this relationship, and whether this population can serve as a biomarker for burn severity
Bigfin reef squid demonstrate capacity for conditional discrimination and projected future carbon dioxide levels have no effect on learning capabilities
Anthropogenic carbon dioxide (CO2) emissions are being absorbed by the oceans, a process known as ocean acidification, and risks adversely affecting a variety of behaviours in a range of marine species, including inhibited learning in some fishes. However, the effects of elevated CO2 on learning in advanced invertebrates such as cephalopods are unknown. Any impacts to the learning abilities of cephalopods could have far-reaching consequences for their populations and the communities they inhabit. Cephalopods have some of the most advanced cognitive abilities among invertebrates and are one of the few invertebrate taxa in which conditional discrimination has been demonstrated, though the trait has not been demonstrated in any species of squid. Here, we tested for the first time the capacity for conditional discrimination in a squid species (Sepioteuthis lessoniana). Furthermore, we investigated the effects of projected future CO2 levels (1,084 mu atm) on conditional discrimination and learning more generally. A three-task experiment within a two-choice arena was used to test learning and conditional discrimination. Learning was measured by improvements in task completion in repeated trials over time and the number of trials required to pass each task. Squid exhibited significant learning capabilities, with an increase in correct choices over successive trials and a decrease in the number of trials needed to complete the successive tasks. Six of the 12 squid tested successfully passed all three tasks indicating a capacity for conditional discrimination in the species. Elevated CO2 had no effect on learning or on the capacity for conditional discrimination in squid. This study highlights the remarkable cognitive abilities of S. lessoniana, demonstrated by their capacity for conditional discrimination, and suggests that ocean acidification will not compromise learning abilities. However, other behavioural traits in the species have been shown to be altered at comparable elevated CO2 conditions. It is not clear why some ecologically important behaviours are altered by elevated CO2 whereas others are unaffected. Future research should focus on the physiological mechanism responsible for altered behaviours in squid at elevated CO2
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