2,090 research outputs found

    Economics knowledge, attitudes and experience of student teachers in Scotland

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    There is a move away from teaching economics as a separate subject in Scotland. It is now mainly taught within Business Management courses in upper secondary school and is embedded within several subject areas in both primary and early secondary curricula, a move that is in step with broader curricular aims to break down barriers among subjects. This writing discusses the need for clearly situated teaching and learning of economics, provided by teachers provided by teachers who have sufficient background knowledge to devise effective contexts for learning, whether or not it is taught as a discrete subject. The results of a survey of student teachers' levels of economic literacy are analysed and recommendations made for the preparation of teachers to deal effectively with embedded approaches to teaching about economics

    The bloodstream differentiation - division of Trypanosoma brucei studied using mitochondrial markers

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    In the bloodstream of its mammalian host, the African trypanosome Trypanosoma brucei undergoes a life cycle stage differentiation from a long, slender form to a short, stumpy form. This involves three known major events: exit from a proliferative cell cycle, morphological change and mitochondrial biogenesis. Previously, models have been proposed accounting for these events (Matthews & Gull 1994a). Refinement of, and discrimination between, these models has been hindered by a lack of stage-regulated antigens useful as markers at the single-cell level. We have now evaluated a variety of cytological markers and applied them to investigate the coordination of phenotypic differentiation and cell cycle arrest. Our studies have focused on the differential expression of the mitochondrial enzyme dihydrolipoamide dehydrogenase relative to the differentiation-division of bloodstream trypanosomes. The results implicate a temporal order of events: commitment, division, phenotypic differentiation

    What happened? Do preschool children and capuchin monkeys spontaneously use visual traces to locate a reward?

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    This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 Research and Innovation Programme (grant agreement no. 639072). Edinburgh Zoo's Living Links Research Facility is core supported by the Royal Zoological Society of Scotland (registered charity no.: SC004064) through funding generated by its visitors, members and supporters.The ability to infer unseen causes from evidence is argued to emerge early in development and to be uniquely human. We explored whether preschoolers and capuchin monkeys could locate a reward based on the physical traces left following a hidden event. Preschoolers and capuchin monkeys were presented with two cups covered with foil. Behind a barrier, an experimenter (E) punctured the foil coverings one at a time, revealing the cups with one cover broken after the first event and both covers broken after the second. One event involved hiding a reward, the other event was performed with a stick (order counterbalanced). Preschoolers and, with additional experience, monkeys could connect the traces to the objects used in the puncturing events to find the reward. Reversing the order of events perturbed the performance of 3-year olds and capuchins, while 4-year-old children performed above chance when the order of events was reversed from the first trial. Capuchins performed significantly better on the ripped foil task than they did on an arbitrary test in which the covers were not ripped but rather replaced with a differently patterned cover. We conclude that by 4 years of age children spontaneously reason backwards from evidence to deduce its cause.Publisher PDFPeer reviewe

    Use of Cyclic Simple Shear Testing in Evaluation of the Deformation Potential of Liquefiable Soils

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    In recent years, a significant research effort has been focused on assessing the performance of structures founded on potentially liquefiable materials. While significant progress has been made on predictive tools for cases in which large deformations are likely, the ability to accurately and reliably predict small to moderate lateral deformations (\u3c1m) has proven more elusive. As a result, there is a universal need for high quality, element-level laboratory test data to calibrate and validate constitutive laws and numerical models for predicting the deformation of soil with limited liquefaction potential. To address this increasingly urgent need, a comprehensive cyclic simple shear testing program on liquefiable sands has been undertaken using the UC Berkeley Bi-directional Simple Shear Device. Many of the tests performed have new and innovative aspects that can provide information and insight into the behavior of soils showing limited deformation potential. Descried in this paper are results from a Kα test series, which replicates sloping ground conditions, and a newly developed and innovative “fabric” test series, which examines the influence of previous loading history on soil fabric and behavior

    Morphologic Changes of Apoptosis Induced in Human Chronic Myelogenous Leukemia Blast Cells by SC41661A (Searle), A Selective Inhibitor of 5-Lipoxygenase

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    Several inhibitors of the arachidonic acid-metabolizing enzyme, 5-lipoxygenase reduce proliferation of hematopoietic and non-hematopoietic cells and cell lines and some cells undergo limited differentiation. Cells were cultured from patients with chronic myelogenous leukemia in blast crisis with the selective inhibitor of 5-lipoxygenase,SC41661A[3-{3,5-bis(1,1-dimethyl)-4-hydroxyphenyl}hiol]-N-methyl-N-[2-(2-phridinyl-propanamide)]. Cells cultured for 3 to 5 days with 40 ÎŒM SC41661A exhibited reduced cellular numbers along with ultrastructural changes and DNA laddering characteristic of apoptosis. Similar culture conditions reduced proliferation of U937 monoblastoid cells. In U937 cells, the ultrastructural features of apoptosis were not observed at 72 hours, when DNA laddering was present and cell numbers were reduced, but was present after 144 hours of culture. Dissociation between certain morphologic and biochemical sequelae of apoptosis has been described in other systems. These observations are of interest since the induction of apoptosis in dividing chronic myelogenous leukemia (CML) cells by a noncytotoxic agent suggests paradigmatically new sites for therapeutic intervention

    Trypanosoma Cruzi Surface change characteristics of cultured epimastigotes, trypomastigotes and amastigotes

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    Inhibitory control and cue relevance modulate chimpanzees’ (Pan troglodytes) performance in a spatial foraging task

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    This project has received funding from the European Research Council under the European Union’s Horizon 2020 research and innovation program (Grant Agreement 639072). Brandon Tinklenberg was supported by a grant from the Social Sciences and Humanities Research Council of Canada (SSHRC 435-2016-1051).Inhibition tasks usually require subjects to exert control to act correctly when a competing action plan is prepotent. In comparative psychology, one concern about the existing inhibition tasks is that the relative contribution of inhibitory control to performance (as compared to learning or object knowledge) is rarely explicitly investigated. We addressed this problem by presenting chimpanzees with a spatial foraging task in which they could acquire food more efficiently by learning which objects were baited. In Experiment 1, we examined how objects that elicited a prepotent approach response, transparent cups containing food, affected their learning rates. Although showing an initial bias to approach these sealed cups with visible food, the chimpanzees learned to avoid them more quickly across sessions compared to a color discrimination. They also learned a color discrimination more quickly if the incorrect cups were sealed such that a piece of food could never be hidden inside them. In Experiment 2, visible food of 2 different types was sealed in the upper part of the cups: 1 type signaled the presence of food reward hidden underneath; the cups with the other type were sealed. The chimpanzees learned more quickly in a congruent condition (the to-be-chosen food cue matched the reward) than in an incongruent condition (the to-be-avoided food cue matched the reward). Together, these findings highlight that performance in inhibition tasks is affected by several other cognitive abilities such as object knowledge, memory, and learning, which need to be quantified before meaningful comparisons can be drawn.PostprintPeer reviewe

    How can I find what I want? Can children, chimpanzees and capuchin monkeys form abstract representations to guide their behavior in a sampling task?

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    Authors are grateful to the Royal Zoological Society of Scotland (RZSS) and the University of St Andrews for core financial support to the RZSS Edinburgh Zoo’s Living Links Research Centre, where this project was carried out. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No. [639072]). We acknowledge the support of the Natural Sciences and Engineering Research Council of Canada (NSERC) [funding reference number 2016-05552].Abstract concepts are a powerful tool for making wide-ranging predictions in new situations based on little experience. Whereas looking-time studies suggest an early emergence of this ability in human infancy, other paradigms like the relational match to sample task often fail to detect abstract concepts until late preschool years. Similarly, non-human animals show difficulties and often succeed only after long training regimes. Given the considerable influence of slight task modifications, the conclusiveness of these findings for the development and phylogenetic distribution of abstract reasoning is debated. Here, we tested the abilities of 3 to 5-year-old children, chimpanzees, and capuchin monkeys in a unified and more ecologically valid task design based on the concept of “overhypotheses” (Goodman, 1955). Participants sampled high- and low-valued items from containers that either each offered items of uniform value or a mix of high- and low-valued items. In a test situation, participants should switch away earlier from a container offering low-valued items when they learned that, in general, items within a container are of the same type, but should stay longer if they formed the overhypothesis that containers bear a mix of types. We compared each species' performance to the predictions of a probabilistic hierarchical Bayesian model forming overhypotheses at a first and second level of abstraction, adapted to each species' reward preferences. Children and, to a more limited extent, chimpanzees demonstrated their sensitivity to abstract patterns in the evidence. In contrast, capuchin monkeys did not exhibit conclusive evidence for the ability of abstract knowledge formation.Publisher PDFPeer reviewe

    Chemical determinants of occupational hypersensitivity pneumonitis

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    Background: Workplace inhalational exposures to low molecular weight (LMW) chemicals cause hypersensitivity pneumonitis (HP) as well as the more common manifestation of respiratory hypersensitivity, occupational asthma (OA). Aims: To explore whether chemical causation of HP is associated with different structural and physico-chemical determinants from OA. Methods: Chemical causes of human cases of HP and OA were identified from searches of peer-reviewed literature up to the end of 2011. Each chemical was categorised according to whether or not it had been the attributed cause of at least one case of HP. The predicted asthma hazard was determined for each chemical using a previously developed quantitative structure-activity relationship (QSAR) model. The chemicals in both sets were independently and ‘blindly’ analysed by an expert in mechanistic chemistry for a qualitative prediction of protein cross-linking potential and determination of lipophilicity (log Kow). Results: Ten HP causing chemicals were identified and had a higher median QSAR predicted asthma hazard than the control group of 101 OA causing chemicals (p < 0.005). Nine of ten HP causing chemicals were predicted to be protein cross-linkers compared to 24/92 controls (p<0.0001). The distributions of log Kow indicated higher values for the HP list (median 3.47) compared to controls (median 0.81) (p < 0.05). Conclusion: These findings suggest that chemicals capable of causing HP tend to have higher predicted asthma hazard, are more lipophilic and are more likely to be protein cross-linkers than those causing OA. Key words: hypersensitivity pneumonitis, occupational chemicals, occupational respiratory disease, toxic inhalatio
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