937 research outputs found

    How Does Pre-Service Teacher Preparedness to Use ICTs for Learning and Teaching Develop Through Their Degree Program?

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    It is now well accepted that graduating teachers need the capacity to integrate Information and Communication Technologies (ICTs) in ways which harness their learning affordances and develop students’ digital literacies. However, effective ICT integration in the classroom is challenging because it requires complex application of technological, pedagogical and content knowledge. A key challenge for teacher educators is the provision of learning experiences at university and on professional placement which will allow pre-service teachers to develop these capacities. Understanding the learning process of pre-service teachers in relation to ICT integration is essential if this teacher education challenge is to be addressed. This article reports on a study in which a group of 11 pre-service Primary school teachers were interviewed at stages through their program with a focus on their preparedness to use ICTs in their teaching. The study used a model developed by Taylor (2004), which defines three stages of teacher ICT capacity development (uncritical and accepting, beginning to problematise, and reflection and theorisation), as an analytic lens. Using this model, pre-service teachers were positioned against the stages in the model at six points during their four year program, and factors contributing to their movement through the phases were identified

    The Predictive Link between Matrix and Metastasis

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    Cancer spread (metastasis) is responsible for 90% of cancer-related fatalities. Informing patient treatment to prevent metastasis, or kill all cancer cells in a patient\u27s body before it becomes metastatic is extremely powerful. However, aggressive treatment for all non-metastatic patients is detrimental, both for quality of life concerns, and the risk of kidney or liver-related toxicity. Knowing when and where a patient has metastatic risk could revolutionize patient treatment and care. In this review, we attempt to summarize the key work of engineers and quantitative biologists in developing strategies and model systems to predict metastasis, with a particular focus on cell interactions with the extracellular matrix (ECM), as a tool to predict metastatic risk and tropism

    A Biomaterial Screening Approach Reveals Microenvironmental Mechanisms of Drug Resistance

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    Traditional drug screening methods lack features of the tumor microenvironment that contribute to resistance. Most studies examine cell response in a single biomaterial platform in depth, leaving a gap in understanding how extracellular signals such as stiffness, dimensionality, and cell–cell contacts act independently or are integrated within a cell to affect either drug sensitivity or resistance. This is critically important, as adaptive resistance is mediated, at least in part, by the extracellular matrix (ECM) of the tumor microenvironment. We developed an approach to screen drug responses in cells cultured on 2D and in 3D biomaterial environments to explore how key features of ECM mediate drug response. This approach uncovered that cells on 2D hydrogels and spheroids encapsulated in 3D hydrogels were less responsive to receptor tyrosine kinase (RTK)-targeting drugs sorafenib and lapatinib, but not cytotoxic drugs, compared to single cells in hydrogels and cells on plastic. We found that transcriptomic differences between these in vitro models and tumor xenografts did not reveal mechanisms of ECM-mediated resistance to sorafenib. However, a systems biology analysis of phospho-kinome data uncovered that variation in MEK phosphorylation was associated with RTK-targeted drug resistance. Using sorafenib as a model drug, we found that co-administration with a MEK inhibitor decreased ECM-mediated resistance in vitro and reduced in vivo tumor burden compared to sorafenib alone. In sum, we provide a novel strategy for identifying and overcoming ECM-mediated resistance mechanisms by performing drug screening, phospho-kinome analysis, and systems biology across multiple biomaterial environments

    A cell–ECM screening method to predict breast cancer metastasis

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    Breast cancer preferentially spreads to the bone, brain, liver, and lung. The clinical patterns of this tissue-specific spread (tropism) cannot be explained by blood flow alone, yet our understanding of what mediates tropism to these physically and chemically diverse tissues is limited. While the micro- environment has been recognized as a critical factor in governing metastatic colonization, the role of the extracellular matrix (ECM) in mediating tropism has not been thoroughly explored. We created a simple biomaterial platform with systematic control over the ECM protein density and composition to determine if integrin binding governs how metastatic cells differentiate between secondary tissue sites. Instead of examining individual behaviors, we compiled large patterns of phenotypes associated with adhesion to and migration on these controlled ECMs. In combining this novel analysis with a simple biomaterial platform, we created an in vitro fingerprint that is predictive of in vivo metastasis. This rapid biomaterial screen also provided information on how b1, a2, and a6 integrins might mediate metastasis in patients, providing insights beyond a purely genetic analysis. We propose that this approach of screening many cell–ECM interactions, across many different heterogeneous cell lines, is predictive of in vivo behavior, and is much simpler, faster, and more economical than complex 3D environments or mouse models. We also propose that when specifically applied toward the question of tissue tropism in breast cancer, it can be used to provide insight into certain integrin subunits as therapeutic targets

    Anomalously Diffusing and Persistently Migrating Cells in 2D and 3D Culture Environments

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    Appropriately chosen descriptive models of cell migration in biomaterials will allow researchers to characterize and ultimately predict the movement of cells in engineered systems for a variety of applications in tissue engineering. The persistent random walk (PRW) model accurately describes cell migration on two-dimensional (2D) substrates. However, this model inherently cannot describe subdiffusive cell movement, i.e. migration paths in which the root mean square displacement increases more slowly than the square root of the time interval. Subdiffusivity is a common characteristic of cells moving in confined environments, such as three-dimensional (3D) porous scaffolds, hydrogel networks, and in vivo tissues. We demonstrate that a generalized anomalous diffusion (AD) model, which uses a simple power law to relate the mean square displacement (MSD) to time, more accurately captures individual cell migration paths across a range of engineered 2D and 3D environments than does the more commonly used PRW model. We used the AD model parameters to distinguish cell movement profiles on substrates with different chemokinetic factors, geometries (2D vs 3D), substrate adhesivities, and compliances. Although the two models performed with equal precision for superdiffusive cells, we suggest a simple AD model, in lieu of PRW, to describe cell trajectories in populations with a significant subdiffusive fraction, such as cells in confined, 3D environments

    Auditing the office for learning and teaching resource library

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    The Australian government Office for Learning and Teaching\u27s (OLT) Resource Library is a key means of disseminating the outcomes from projects funded by itself and its predecessor organisations, the Australian Learning and Teaching Council (ALTC) and the Carrick Institute. In order to apply the recommendations and resources emanating from these projects, it is vital that educators and other stakeholders are aware of, and effectively able to use, the Resource Library. Based on anecdotal evidence indicating a lack of awareness of the Resource Library and problems with consistently being able to search for and retrieve relevant resources from the database, the OLT commissioned a project to formally evaluate the Library and redesign it to improve access and usability. This paper reports on the project\u27s progress, including the results from a questionnaire completed by 117 higher education stakeholders

    Auditing the Office for Learning and Teaching Resource Library

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    The Australian government Office for Learning and Teaching’s (OLT) Resource Library was a key means of disseminating the outcomes from projects funded by itself and its predecessor organisations, the Australian Learning and Teaching Council (ALTC) and the Carrick Institute. In order to apply the recommendations and resources emanating from these projects, it is vital that educators and other stakeholders are aware of, and effectively able to use, the Resource Library. Based on anecdotal evidence indicating a lack of awareness of the Resource Library and problems with consistently being able to search for and retrieve relevant resources from the database, the OLT commissioned a project to formally evaluate the Library and redesign it to improve access and usability. This paper reports on the project’s progress, including the results from a questionnaire completed by 117 higher education stakeholders

    Comparative Study of Multicellular Tumor Spheroid Formation Methods and Implications for Drug Screening

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    Improved in vitro models are needed to better understand cancer progression and bridge the gap between in vitro proof-of-concept studies, in vivo validation, and clinical application. Multicellular tumor spheroids (MCTS) are a popular method for three-dimensional (3D) cell culture, because they capture some aspects of the dimensionality, cell–cell contact, and cell–matrix interactions seen in vivo. Many approaches exist to create MCTS from cell lines, and they have been used to study tumor cell invasion, growth, and how cells respond to drugs in physiologically relevant 3D microenvironments. However, there are several discrepancies in the observations made of cell behaviors when comparing between MCTS formation methods. To resolve these inconsistencies, we created and compared the behavior of breast, prostate, and ovarian cancer cells across three MCTS formation methods: in polyNIPAAM gels, in microwells, or in suspension culture. These methods formed MCTS via proliferation from single cells or passive aggregation, and therefore showed differential reliance on genes important for cell–cell or cell–matrix interactions. We also found that the MCTS formation method dictated drug sensitivity, where MCTS formed over longer periods of time via clonal growth were more resistant to treatment. Toward clinical application, we compared an ovarian cancer cell line MCTS formed in polyNIPAAM with cells from patient-derived malignant ascites. The method that relied on clonal growth (PolyNIPAAM gel) was more time and cost intensive, but yielded MCTS that were uniformly spherical, and exhibited the most reproducible drug responses. Conversely, MCTS methods that relied on aggregation were faster, but yielded MCTS with grape-like, lobular structures. These three MCTS formation methods differed in culture time requirements and complexity, and had distinct drug response profiles, suggesting the choice of MCTS formation method should be carefully chosen based on the application required
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