This paper is based on the deliberations of the Assessment Working Group at EDUsummIT 2015 in Bangkok, Thailand. All of the members of Thematic Working Group 5 (TWG5) have contributed to this ...synthesis of potentials, concerns and issues with regard to the role of technology in assessment as, for and of learning in the 21^(st) century. The group decided to focus primarily on formative assessment rather than summative assessment and high stakes testing. Formative assessments and feedback provide an important opportunity to support and enhance student learning. Recognizing shifts in education towards blended and online learning with problem-based and inquiry-based approaches led to considerations of technologies that could effectively support formative assessment and informative feedback to 21^(st) century learners. The paper concludes with a summary of conclusions and recommendations of the working group to be taken up in subsequent efforts.
MicroRNA-34a (miR-34a) is a master regulator of signaling networks that maintains normal physiology and disease and is currently in development as a miRNA-based therapy for cancer. Prior studies have ...reported low miR-34a expression in osteosarcoma; however, the molecular mechanisms underlying miR-34a activity in osteosarcoma are not well-defined. Therefore, this study evaluated the role of miR-34a in regulating signal transduction pathways that influence cell death in osteosarcoma. Levels of miR-34a were attenuated in human osteosarcoma cells and xenografts of the Pediatric Preclinical Testing Consortium (PPTC). Bioinformatics predictions identified stathmin 1 (STMN1) as a potential miR-34a target. Biotin pull-down assay and luciferase reporter analysis confirmed miR-34a target interactions within the STMN1 mRNA 3'-untranslated region. Overexpression of miR-34a in osteosarcoma cells suppressed STMN1 expression and reduced cell growth
Restoration of miR-34a led to microtubule destabilization and increased βIII-tubulin expression, with corresponding G
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phase cell-cycle arrest and apoptosis. Knockdown of the Sp1 transcription factor, by siRNA silencing, also upregulated βIII-tubulin expression in osteosarcoma cells, suggesting that miR-34a indirectly affects Sp1. Validating the coordinating role of miR-34a in microtubule destabilization, when miR-34a was combined with either microtubule inhibitors or chemotherapy, STMN1 phosphorylation was suppressed and there was greater cytotoxicity in osteosarcoma cells. These results demonstrate that miR-34a directly represses STMN1 gene and protein expression and upregulates βIII-tubulin, leading to disruption of the microtubule network and cell death.
The miR-34a/STMN1/βIII-tubulin axis maintains the microtubule cytoskeleton in osteosarcoma, and combining miR-34a with microtubule inhibitors can be investigated as a novel therapeutic strategy.
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•Hurricane forecasts typically neglect the simulation of flood inundation.•A 2D hydrodynamic model is coupled to NOAA forecasts of Hurricane Harvey.•In considering fluvial, pluvial and coastal ...flooding, it matches observations well.•Simple, zero-physics approaches exhibit relatively low performance in comparison.•Representing the physics of flooding is both possible and necessary in forecasts.
Forecasts of tropical cyclones have seen rapid improvements in recent years as expanding computational capacity permits more runs of finer resolution meteorological models with increasing representation of physical processes. However, the utilization of a hydrodynamic component in these models is often neglected, meaning flood forecasts typically output point water levels that give little indication of a projected inundation extent on the ground. Here, we append this critical component to the forecast cascade by coupling Fathom-US, a continental-scale hydraulic model which employs the LISFLOOD-FP numerical scheme, to forecasts of streamflow, rainfall and coastal surge height from the National Oceanic and Atmospheric Administration (NOAA). Medium-term (2–15 days) flood inundation forecasts, as well as hindcasts driven by real-time observations, were executed for Hurricane Harvey by rapidly simulating pluvial and coastal flood hazard and extracting fluvial flood maps from an existing US-wide simulation library. The resultant ~30 m resolution depth grids were then validated against post-event observations collated by the US Geological Survey. Across the disaster zone, the hindcast (forecast) model captured, on average, 78% (75%) of the benchmark flood extent, obtained a Critical Success Index of 0.66 (0.57) and deviated from observed high water marks by ~1 m (~1.2 m). When compared to a simpler GIS-based approach, the hydraulic model exhibited much higher skill in replicating observations. This study shows that fully hydrodynamic approaches can be practicably employed in large-scale forecast frameworks at high resolution to produce skillful projections of inundation extent without significantly affecting the forecast lead time.
New texts from Greek antiquity continue to emerge on scraps of papyrus from the sands of Egypt, not only adding to the surviving corpus of classical and Hellenistic literature, but also occasionally ...offering a glimpse into how these poems were studied in antiquity.New Literary Papyri from the Michigan Collection: Mythographic Lyric and a Catalogue of Poetic First Linespresents three such new texts: an innovative lyric poem on the Trojan cycle, a scholarly anthology of lyric verses, and a brief but enigmatic third text. Cassandra Borges and C. Michael Sampson offer the original Greek text of these pieces, along with their scholarly commentary, analyzing their features in a variety of contexts-historical, cultural, poetic, mythological, religious, and scholarly.
The fragments collected here are of considerable antiquity (late third to second century BCE) a fact that is significant inasmuch as it places them among the oldest Greek papyri, but all the more so because in this period, a scholarly community was thriving in Ptolemaic Alexandria, the political and cultural capital of Hellenistic Egypt. The fragments bear witness to that scholarly activity: not only is their anthology of poetic verses consistent with other scholarly selections, but the very survival of these texts may well be at least partially indebted to the work of the Alexandrians in studying and propagating Greek literature in Egypt.
This edition supplements the 1970s work of Reinhold Merkelbach and Denys Page. Recent digitizing for the APIS project revealed a previously unsuspected join with other material, however, which alone warrants a new, comprehensive edition and analysis.
: A procedure has been developed to analyze the trace element concentrations in glass fragments using particle‐induced X‐ray emission (PIXE) spectrometry. This method involves using accelerated ...protons to excite inner‐shell electronic transitions of target atoms and recording the resultant X‐rays to characterize the trace element concentrations. The protocol was able to identify those glass fragments that originated from different sources based on their elemental analyses. The protocol includes specific approaches to calculating uncertainties and handling measurements below the level of detection. The results indicate that this approach has increased sensitivity for several elements with higher atomic number compared with X‐ray fluorescence methods. While not as sensitive as laser‐ablation or inductively coupled plasma mass spectrometry methods of dissolved samples, it is entirely nondestructive and entails a much simpler sample preparation process that may be used to presort glass fragments for more comprehensive elemental analysis. As such, the technique described may have a niche role in forensic glass analysis.
Global flood hazard models have recently become a reality thanks to the release of open access global digital elevation models, the development of simplified and highly efficient flow algorithms, and ...the steady increase in computational power. In this commentary we argue that although the availability of open access global terrain data has been critical in enabling the development of such models, the relatively poor resolution and precision of these data now limit significantly our ability to estimate flood inundation and risk for the majority of the planet’s surface. The difficulty of deriving an accurate ‘bare-earth’ terrain model due to the interaction of vegetation and urban structures with the satellite-based remote sensors means that global terrain data are often poorest in the areas where people, property (and thus vulnerability) are most concentrated. Furthermore, the current generation of open access global terrain models are over a decade old and many large floodplains, particularly those in developing countries, have undergone significant change in this time. There is therefore a pressing need for a new generation of high resolution and high vertical precision open access global digital elevation models to allow significantly improved global flood hazard models to be developed.
Abstract
This paper reports the development of a ∼30 m resolution two‐dimensional hydrodynamic model of the conterminous U.S. using only publicly available data. The model employs a highly efficient ...numerical solution of the local inertial form of the shallow water equations which simulates fluvial flooding in catchments down to 50 km
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and pluvial flooding in all catchments. Importantly, we use the U.S. Geological Survey (USGS) National Elevation Dataset to determine topography; the U.S. Army Corps of Engineers National Levee Database to explicitly represent known flood defenses; and global regionalized flood frequency analysis to characterize return period flows and rainfalls. We validate these simulations against the complete catalogue of Federal Emergency Management Agency (FEMA) Special Flood Hazard Area (SFHA) maps and detailed local hydraulic models developed by the USGS. Where the FEMA SFHAs are based on high‐quality local models, the continental‐scale model attains a hit rate of 86%. This correspondence improves in temperate areas and for basins above 400 km
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. Against the higher quality USGS data, the average hit rate reaches 92% for the 1 in 100 year flood, and 90% for all flood return periods. Given typical hydraulic modeling uncertainties in the FEMA maps and USGS model outputs (e.g., errors in estimating return period flows), it is probable that the continental‐scale model can replicate both to within error. The results show that continental‐scale models may now offer sufficient rigor to inform some decision‐making needs with dramatically lower cost and greater coverage than approaches based on a patchwork of local studies.
Key Points
A 30 m resolution flood hazard model of the entire conterminous United States is built using publicly available data
Delineations of flood hazard are comprehensively validated against United States government agency benchmarks
Model performance is largely comparable to quality local models, offering cheaper hazard information with complete spatial coverage
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