749 research outputs found

    The potential for using visual elicitation in understanding preschool teachers’ beliefs of appropriate educational practices

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    We explore the use of video and photo elicitation in a research study undertaken to understand the way in which preschool teachers perceive and construct their provision of children’s educational experiences. We explore the value of visually elicited interviews based on video footage and photographs captured during teaching and learning in four classrooms in two preschool settings in Kenya. Through visually elicited interviews, both the teachers and the researcher constructed meaningful conversations (interviews) to explore preschool teachers’ practical experiences and their beliefs, understanding and interpretation of developmentally appropriate educational practices. This paper targets the possible value of and contribution made by visual data generation procedures, as well as their inherent challenges, in order to add to the body of knowledge on visually elicited interviews

    Offside goals and induced breaches of contract

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    An analysis of Global Resources Group Ltd v Mackay which explores the possibility of building links between the offside goals rule and nominate delict of inducing breach of contract

    A bioinformatics approach to the development of immunoassays for specified risk material in canned meat products

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    A bioinformatics approach to developing antibodies to specific proteins has been evaluated for the production of antibodies to heat-processed specified risk tissues from ruminants (brain and eye tissue). The approach involved the identification of proteins specific to ruminant tissues by interrogation of the annotation fields within the Swissprot database. These protein sequences were then interrogated for peptide sequences that were unique to the protein. Peptides were selected that met these criteria as close as possible and that were also theoretically resistant to either pepsin or trypsin. The selected peptides were synthesised and used as immunogens to raise monoclonal antibodies. Antibodies specific for the synthetic peptides were raised to half of the selected peptides. These antibodies have each been incorporated into a competitive enzyme-linked immunosorbent assay (ELISA) and shown to be able to detect the heat-processed parent protein after digestion with either pepsin or trypsin. One antibody, specific for alpha crystallin peptide (from bovine eye tissue), was able to detect the peptide in canned meat products spiked with 10% eye tissue. These results, although preliminary in nature, show that bioinformatics in conjunction with enzyme digestion can be used to develop ELISA for proteins in high-temperature processed foods and demonstrate that the approach is worth further stud

    Mean curvature flow in asymptotically flat product spacetimes

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    We consider the long-time behaviour of the mean curvature flow of spacelike hypersurfaces in the Lorentzian product manifold M×RM\times\mathbb{R}, where MM is asymptotically flat. If the initial hypersurface F0M×RF_0\subset M\times\mathbb{R} is uniformly spacelike and asymptotic to M×{s}M\times\left\{s\right\} for some sRs\in\mathbb{R} at infinity, we show that a mean curvature flow starting at F0F_0 exists for all times and converges uniformly to M×{s}M\times\left\{s\right\} as tt\to \infty.Comment: 23 pages, final versio

    TOR1A mutation-related isolated childhood-onset generalised dystonia in South Africa

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    Background. Childhood-onset generalised dystonia is commonly caused by TOR1A mutations and is known to respond well to pallidal deep-brain stimulation (DBS) surgery. The incidence and prevalence of monogenic dystonia in individuals from Africa and specifically of African ancestry are unknown, and no local cases of TOR1A mutation dystonia are found in the literature.Objectives. To describe our experience with the outcome of TOR1A mutation-positive patients with isolated generalised dystonia (IGD) of childhood onset who were treated with pallidal DBS.Methods. All patients with TOR1A mutations from Steve Biko Academic Hospital and the Pretoria Neurology Institute in Pretoria, South Africa (SA), who underwent DBS for IGD of childhood onset were identified. We conducted a retrospective analysis of their demographics, clinical presentation and time to generalisation, genetic status and family history, and response to DBS treatment of the internal segment of the globus pallidus (GPi), utilising pre- and post-surgical scores of the United Dystonia Rating Scale (UDRS).Results. Three patients, all of black African ancestry, were identified. The median age at onset was 12 years and the median time to surgery from dystonia generalisation was 3 years. Two children presented with cervical-onset dystonia. Two patients were related, representing the only two with a positive family history. All three patients had a positive outcome after surgery, with improvement of 67 - 90% on the UDRS recorded at last follow-up.Conclusions. TOR1A mutations are found in SA patients of black African ancestry, with age of onset and generalisation comparable to those described in international studies. However, onset with cervical dystonia was more common than previously reported. Response to GPi DBS was excellent in all patients.

    Unlocking the Inaccessible Energy Density of Sodium Vanadium Fluorophosphate Electrode Materials by Transition Metal Mixing

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    Sodium (Na) vanadium (V) fluorophosphate NaxV2(PO4)2F3\mathrm{Na_xV_2(PO_4)_2F_3} (NVPF) is a highly attractive intercalation electrode material due to its high operation voltage, large capacity, and long cycle life. However, several issues limit the full utilization of NVPF's energy density: 1) the high voltage plateau associated with extracting the "third" Na ion in the reaction N1_1VPF \rightarrow VPF (~4.9 V vs Na/Na+^+) appears above the electrochemical stability window of most practical electrolytes (~4.5 V); 2) a sudden drop in Na-ion diffusivity is observed near composition Na1V2(PO4)2F3\mathrm{Na_1V_2(PO_4)_2F_3}. Therefore, it is important to investigate the potential substitution of V by other transition metals in NVPF derivatives, which can access the extraction of the third Na-ion. In this work, we investigate the partial substitution of V with molybdenum (Mo), niobium (Nb), or tungsten (W) in NVPF to improve its energy density. We examine the structural and electrochemical behaviors of NaxV2yMoy(PO4)2F3\mathrm{Na_xV_{2-y}Mo_y(PO_4)_2F_3}, NaxV2yNby(PO4)2F3\mathrm{Na_xV_{2-y}Nb_y(PO_4)_2F_3}, and NaxW2(PO4)2F3\mathrm{Na_xW_{2}(PO_4)_2F_3} across the whole Na composition region of 0 \leq x \leq 4, and at various transition metal substitution levels, namely, y=0.5, 1.0, 1.5, 2.0 for Mo, and y=1.0, 2.0 for Nb. We find that partial substitution of 50% V by Mo in NVPF reduces the voltage plateau for extracting the third Na ion by 0.6 Volts, which enables further Na extraction from Na1Mo2(PO4)2F3\mathrm{Na_1Mo_{2}(PO_4)_2F_3} and increases the theoretical gravimetric capacity from ~128 to ~174 mAh/g. Analysis of the migration barriers for Na-ions in NaxVMo(PO4)2F3\mathrm{Na_xVMo(PO_4)_2F_3} unveils improved kinetic properties over NVPF. The proposed NaxVMo(PO4)2F3\mathrm{Na_xVMo(PO_4)_2F_3} material provides an optimal gravimetric energy density of ~577.3 Wh/kg versus ~507 Wh/kg for the pristine NVPF, which amounts to an increase of ~13.9%

    Harnessing ChatGPT for thematic analysis: Are we ready?

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    ChatGPT is an advanced natural language processing tool with growing applications across various disciplines in medical research. Thematic analysis, a qualitative research method to identify and interpret patterns in data, is one application that stands to benefit from this technology. This viewpoint explores the utilization of ChatGPT in three core phases of thematic analysis within a medical context: 1) direct coding of transcripts, 2) generating themes from a predefined list of codes, and 3) preprocessing quotes for manuscript inclusion. Additionally, we explore the potential of ChatGPT to generate interview transcripts, which may be used for training purposes. We assess the strengths and limitations of using ChatGPT in these roles, highlighting areas where human intervention remains necessary. Overall, we argue that ChatGPT can function as a valuable tool during analysis, enhancing the efficiency of the thematic analysis and offering additional insights into the qualitative data.Comment: 23 pages, 7 figures, 3 tables, 1 textbo

    Endogenous orienting modulates the Simon effect: critical factors in experimental design

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    Responses are faster when the side of stimulus and response correspond than when they do not correspond, even if stimulus location is irrelevant to the task at hand: the correspondence, spatial compatibility effect, or Simon effect. Generally, it is assumed that an automatically generated spatial code is responsible for this effect, but the precise mechanism underlying the formation of this code is still under dispute. Two major alternatives have been proposed: the referential-coding account, which can be subdivided into a static version and an attention-centered version, and the attention-shift account. These accounts hold clear-cut predictions for attentional cuing experiments. The former would assume a Simon effect irrespective of attentional cuing in its static version, whereas the attention-centered version of the referential-coding account and the attention-shift account would predict a decreased Simon effect on validly as opposed to invalidly cued trials. However, results from previous studies are equivocal to the effects of attentional cuing on the Simon effect. We argue here that attentional cueing reliably modulates the Simon effect if some crucial experimental conditions, mostly relevant for optimizing attentional allocation, are met. Furthermore, we propose that the Simon effect may be better understood within the perspective of supra-modal spatial attention, thereby providing an explanation for observed discrepancies in the literature

    On Multifractal Structure in Non-Representational Art

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    Multifractal analysis techniques are applied to patterns in several abstract expressionist artworks, paintined by various artists. The analysis is carried out on two distinct types of structures: the physical patterns formed by a specific color (``blobs''), as well as patterns formed by the luminance gradient between adjacent colors (``edges''). It is found that the analysis method applied to ``blobs'' cannot distinguish between artists of the same movement, yielding a multifractal spectrum of dimensions between about 1.5-1.8. The method can distinguish between different types of images, however, as demonstrated by studying a radically different type of art. The data suggests that the ``edge'' method can distinguish between artists in the same movement, and is proposed to represent a toy model of visual discrimination. A ``fractal reconstruction'' analysis technique is also applied to the images, in order to determine whether or not a specific signature can be extracted which might serve as a type of fingerprint for the movement. However, these results are vague and no direct conclusions may be drawn.Comment: 53 pp LaTeX, 10 figures (ps/eps

    Effect of Moringa oleifera Lam. leaf powder on the pharmacokinetics of nevirapine in HIV-infected adults: a one sequence cross-over study

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    Moringa oleifera Lam., an herb commonly consumed by HIV-infected people on antiretroviral therapy, inhibits cytochrome P450 3A4, 1A2 and 2D6 activity in vitro; and may alter the pharmacokinetics (PK) of antiretroviral drugs metabolized via the same pathways. However, in vitro drug interaction activity may not translate to a clinically significant effect. Therefore, the effect of moringa leaf powder on the PK of nevirapine in HIV-infected people was investigated. Adult patients at steady-state dosing with nevirapine were admitted for 12-h intensive PK sampling following a 21-day herbal medicine washout. Blood sampling was repeated after 14 days of nevirapine and moringa (1.85 g leaf powder/day) co-administration. Nevirapine plasma concentrations were determined by liquid chromatography-tandem mass spectrometry. To assess the effect of moringa on nevirapine PK, the change in nevirapine area under the plasma concentration–time curve (AUC) was determined. The mean difference in pre- and post-moringa nevirapine, maximum concentration (Cmax) and concentration at 12 h (C12h) were also calculated. The PK parameters were compared by assessing the post/pre geometric mean ratios (GMRs) and associated 90% confidence intervals (CIs). Pharmacokinetics analyses were performed on the results from 11 participants for whom complete data were obtained. The post/pre GMRs and associated 90% CIs for nevirapine were 1.07 (1.00–1.14) for the AUC; 1.06 (0.98–1.16) for Cmax and 1.03 (0.92–1.16) for C12h. Co-administration of Moringa oleifera Lam. leaf powder at the traditional dose did not significantly alter the steady-state PK of nevirapine. Trial registration number NCT01410058 (ClinicalTrials.gov
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