185 research outputs found

    The Long March or Bold Strokes : Comparing Strategies for Adopting EVS Learning Technology at a UK University

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    In recent years there has been much encouragement to investigate the use of classroom technologies to enhance the student learning experience especially in the STEM subjects but now extending across other subject areas as well. A typical classroom technology is electronic voting system (EVS) handsets which allow a lecturer to invite students to vote for their choice from a selection of given answers. Recently, a medium-size UK University has purchased over 9000 EVS handsets for use across the academic Schools as an innovative means for supporting formative and summative testing. Numerous training and support sessions have been provided to staff with the intention of supporting new and experienced users and increasing the take up by academics. As noted in earlier research reported at ECEL 2013, the student feedback was very positive for the use of EVS for formative activities, and less so, for its use in summative assessment. A recent review of the trends of EVS adoption at the University has been undertaken to inform decision-making and future use and support for the technology. One aspect of this review has considered the effectiveness of the strategies adopted by different academic Schools. EVS adoption and use across the University has been compared and placed within Rogers’ theory of the diffusion of innovation. This paper further considers a set of six different strategies adopted for EVS use by academic Schools. They have been categorised according to several variables, including their choice of speed of uptake and the number of handsets in use. The inherent strengths and possible weaknesses of the approaches adopted are considered. Among the questions raised were, does a strategy of large-scale technology adoption over a short time period indicate a greater likelihood of long term engagement and ultimate adoption of the technology? Or, does a longer elapsed time taken for a gradual purchase and adoption of EVS technology suggest a greater inclination for the embedding of technology for enhancing learning? What other success factors should be considered alongside the training and support provided for technology adoption to enhance the likelihood of long term adoption of classroom technologies? The discussion provides a comparison of six different strategies identified across the university and the rationale behind them and then proposes a set of strategy choices which can lead to a greater likelihood of successful adoption of classroom technology

    Cytoplasmic dynein-2 at a glance

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    Autoregulation of RCO by Low-Affinity Binding Modulates Cytokinin Action and Shapes Leaf Diversity

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    Mechanisms through which the evolution of gene regulation causes morphological diversity are largely unclear. The tremendous shape variation among plant leaves offers attractive opportunities to address this question. In cruciferous plants, the REDUCED COMPLEXITY (RCO) homeodomain protein evolved via gene duplication and acquired a novel expression domain that contributed to leaf shape diversity. However, the molecular pathways through which RCO regulates leaf growth are unknown. A key question is to identify genome-wide transcriptional targets of RCO and the DNA sequences to which RCO binds. We investigate this question using Cardamine hirsuta, which has complex leaves, and its relative Arabidopsis thaliana, which evolved simple leaves through loss of RCO. We demonstrate that RCO directly regulates genes controlling homeostasis of the hormone cytokinin to repress growth at the leaf base. Elevating cytokinin signaling in the RCO expression domain is sufficient to both transform A. thaliana simple leaves into complex ones and partially bypass the requirement for RCO in C. hirsuta complex leaf development. We also identify RCO as its own target gene. RCO directly represses its own transcription via an array of low-affinity binding sites, which evolved after RCO duplicated from its progenitor sequence. This autorepression is required to limit RCO expression. Thus, evolution of low-affinity binding sites created a negative autoregulatory loop that facilitated leaf shape evolution by defining RCO expression and fine-tuning cytokinin activity. In summary, we identify a transcriptional mechanism through which conflicts between novelty and pleiotropy are resolved during evolution and lead to morphological differences between species. Hajheidari et al. identify target genes for the RCO homeodomain protein that drove leaf shape diversity. They show that RCO regulates growth via orchestrating homeostasis for the hormone cytokinin and that it also represses its own transcription via low-affinity binding sites. This autorepression helps delimit RCO expression and shape leaf form

    Brachiopods from the Cisuralian–Guadalupian of Darvaz, Tajikistan and implications for Permian stratigraphic correlations

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    In this paper, we describe the upper Cisuralian Safetdara and Gundara formations of the Darvaz mountains, North Pamir, which were part ofthe Kunlun Arc, developed along the active Eurasian margin. The Safetdara Formation comprises massive limestones (mainly cyanobacterial,Tubiphytes and Archaeolithoporella boundstones) alternating with well-bedded bioclastic and oncoidal limestones and an interval of recessiveshales. The formation crops out above the Chelamchi Formation consisting of turbiditic siltstones and sandstones with bioclastic silty limestonesyielding massive limestone olistoliths. The Gundara Formation consists of fine sandstones at the base, followed by well-bedded marly bioclastic,oncoidal and microbial limestones, bearing a rich silicified brachiopod fauna in life-position. Two new taxa have been identified in this association:the cemented coralliform Gundaria insolita n. gen. n. sp. and the pedicle attached Hemileurus politus n. sp. The inferred environmental setting isthat of shoal deposits of warm, shallow, high energy, clear marine waters for the Safetdara Formation. The agglutinated microbial reefs to clusterreefs of the Gundara Formation were probably growing in a muddier, quieter and probably slightly deeper setting.The foraminifers of the Brevaxina Zone suggest a Bolorian age for the top of the Chelamchi Formation, the Safetdara Formation and the baseof the Gundara Formation. Kungurian conodonts have been found in the lower part of the Safetdara Formation. The biostratigraphic data from thesedimentary succession of North Pamir, integrated with those already obtained from Southeast Pamir, allow to refine the correlations between theTethyan regional scale and the International Time Scale. In particular, it seems now clear that the Bolorian and the lower part of the Kubergandiancorrelate to the Kungurian

    Regulator of calcineurin-2 is a centriolar protein with a role in cilia length control

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    Almost every cell in the human body extends a primary cilium. Defective cilia function leads to a set of disorders known as ciliopathies characterised by debilitating developmental defects affecting many tissues. Here we report a new role for regulator of calcineurin 2, RCAN2, in primary cilia function. It localises to centrioles and the basal body and is required to maintain normal cilia length. RCAN2 was identified as the most strongly upregulated gene from a comparative RNAseq analysis of cells in which expression of the Golgi matrix protein giantin had been abolished by gene editing. In contrast to previous work where we showed that depletion of giantin by RNAi results in defects in ciliogenesis and in cilia length control, giantin knockout cells generate normal cilia on serum withdrawal. Furthermore, giantin knockout zebrafish show increased expression of RCAN2. Importantly, suppression of RCAN2 expression in giantin knockout cells results in the same defects in cilia length control seen on RNAi of giantin itself. Together these data define RCAN2 as a regulator of cilia function that can compensate for loss of giantin function.</jats:p

    Perturbation theory for large Stokes number particles in random velocity fields

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    We derive a perturbative approach to study, in the large inertia limit, the dynamics of solid particles in a smooth, incompressible and finite-time correlated random velocity field. We carry on an expansion in powers of the inverse square root of the Stokes number, defined as the ratio of the relaxation time for the particle velocities and the correlation time of the velocity field. We describe in this limit the residual concentration fluctuations of the particle suspension, and determine the contribution to the collision statistics produced by clustering. For both concentration fluctuations and collision velocities, we analyze the differences with the compressible one-dimensional case.Comment: Latex, 12 pages, 2 eps figures include

    An in vitro collagen perfusion wound biofilm model; with applications for antimicrobial studies and microbial metabolomics

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    BackgroundThe majority of in vitro studies of medically relevant biofilms involve the development of biofilm on an inanimate solid surface. However, infection in vivo consists of biofilm growth on, or suspended within, the semi-solid matrix of the tissue, whereby current models do not effectively simulate the nature of the in vivo environment. This paper describes development of an in vitro method for culturing wound associated microorganisms in a system that combines a semi-solid collagen gel matrix with continuous flow of simulated wound fluid. This enables culture of wound associated reproducible steady state biofilms under conditions that more closely simulate the dynamic wound environment. To demonstrate the use of this model the antimicrobial kinetics of ceftazidime, against both mature and developing Pseudomonas aeruginosa biofilms, was assessed. In addition, we have shown the potential application of this model system for investigating microbial metabolomics by employing selected ion flow tube mass spectrometry (SIFT-MS) to monitor ammonia and hydrogen cyanide production by Pseudomonas aeruginosa biofilms in real-time. ResultsThe collagen wound biofilm model facilitates growth of steady-state reproducible Pseudomonas aeruginosa biofilms under wound like conditions. A maximum biofilm density of 1010 cfu slide-1 was achieved by 30 hours of continuous culture and maintained throughout the remainder of the experiment. Treatment with ceftazidime at a clinically relevant dose resulted in a 1.2 – 1.6 log reduction in biofilm density at 72 hours compared to untreated controls. Treatment resulted in loss of complex biofilm architecture and morphological changes to bacterial cells, visualised using confocal microscopy. When monitoring the biofilms using SIFT-MS, ammonia and hydrogen cyanide levels peaked at 12 hours at 2273 ppb (±826.4) and 138 ppb (±49.1) respectively and were detectable throughout experimentation. ConclusionsThe collagen wound biofilm model has been developed to facilitate growth of reproducible biofilms under wound-like conditions. We have successfully used this method to: (1) evaluate antimicrobial efficacy and kinetics, clearly demonstrating the development of antimicrobial tolerance in biofilm cultures; (2) characterise volatile metabolite production by P. aeruginosa biofilms, demonstrating the potential use of this method in metabolomics studies

    Supporting Future Cannabis Policy - Developing a Standard Joint Unit: A Brief Back-Casting Exercise.

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    The standardization of cannabis doses is a priority for research, policy-making, clinical and harm-reduction interventions and consumer security. Scientists have called for standard units of dosing for cannabis, similar to those used for alcohol. A Standard Joint Unit (SJU) would facilitate preventive and intervention models in ways similar to the Standard Drink (SD). Learning from the SD experiences allows researchers to tackle emerging barriers to the SJU by applying modern forecasting methods. During a workshop at the Lisbon Addictions Conference 2019, a back-casting foresight method was used to address challenges and achieve consensus in developing an SJU. Thirty-two professionals from 13 countries and 10 disciplines participated. Descriptive analysis of the workshop was carried out by the organizers and shared with the participants in order to suggest amendments. Several characteristics of the SJU were defined: (1) core values: easy-to use, universal, focused on THC, accurate, and accessible; (2) key challenges: sudden changes in patterns of use, heterogeneity of cannabis compounds as well as in administration routes, variations over time in THC concentrations, and of laws that regulate the legal status of recreational and medical cannabis use); and (3) facilitators: previous experience with standardized measurements, funding opportunities, multi-stakeholder support, high prevalence of cannabis users, and widespread changes in legislation. Participants also identified three initial steps for the implementation of a SJU by 2030: (1) Building a task-force to develop a consensus-based SJU; (2) Expanded available national-level data; (3) Linking SJU consumption to the concept of "risky use," based on evidence of harms
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