291 research outputs found

    Designing Digital Problem Based Learning Tasks that Motivate Students

    Get PDF
    Article about Designing Digital Problem Based Learning Tasks that Motivate Students

    The impacts of major groundwater droughts based on the European Drought Impact Inventory (EDII)

    Get PDF
    Groundwater represents the largest accessible terrestrial water storage. As such, it is of crucial importance for society, as it can uphold provision of hydrological services to society when there is a lack of water during drought. However, when droughts extend over longer periods of time and groundwater abstraction is increased, longer-lasting groundwater droughts can develop, aggravating existing water shortages. This complex interaction results in an ambivalence of groundwater as a drought mitigation agent, and groundwater as a drought hazard impacting society. This behaviour is well-established in theory. However, to date no study exists looking at empirical data regarding how and when groundwater is factually reported as a mitigation agent or as an impact agent. In this study, we build on previous efforts to synthesize text-based reports on drought impacts in the European Drought Impact Inventory (EDII). We extended the EDII with additional, groundwater-related reports. We then analysed the EDII data to find out: a) how is groundwater used during drought and what is its role? b) is it used differently in different climatic or legislative settings? c) did the role of groundwater change over time? To answer these questions, we isolated the reports in the EDII that directly relate to groundwater, and merged them to new groundwater-related impact categories. We qualitatively summarized the way groundwater is reported as an impact, as a hazard, or as a mitigation agent, and provide statistics on the frequency of each occurrence. Preliminary results show that … We further present the temporal development of the reporting, and compare the type and number of occurrence of groundwater-related reports between the UK with a humid climate and the Iberian Peninsula (Spain and Portugal) with a Mediterranean climate. The study will provide the first systematic documentation of groundwater drought impacts. It will thus provide guidance for researchers and water resource professionals considering whether groundwater can be used sustainably as an alternative resource during drought under different circumstances

    Comparative analysis of impacts of groundwater droughts in a European context

    Get PDF
    •Because groundwater is the main source of water supply, droughts propagating into groundwater systems pose a threat to water security. •There is a need to study groundwater droughts in general. •In particular, within the Groundwater Drought Initiative (GDI) project, we aim to understand the impacts that groundwater droughts have on environmental systems and society. •In this study, we screened the European Drought Impact Inventory (EDII, Stahl et al. 2016) for groundwater-related impacts and present some first results

    Searching for the effect of multiple uncontrolled interventions in BRMS

    Get PDF
    We search for the effects of 8 different (uncontrolled) interventions (1intervention per school) on the sub-concepts of learner’s (4th to 8th grade)motivation, self-regulation, and ICT competency data over the past threeyears. Data marking for intervention (yes/no), ICT competence of teachersand the presence of specially trained teachers are added to the formulas.Assessment of ICT competency in 3rd grade can be used as prior. Smoothsillustrate if the (motivation or self-regulation) concepts grow over timegrouped by intervention, school or grade. Grades are nested within schoolsand data is grouped by student. Are we missing anything

    Variability of B and Be stars in the LMC/SMC: binaries and pulsations

    Get PDF
    To study the variability of the 523 B and Be stars observed in the Magellanic clouds with the VLT-FLAMES, we cross-matched the stars of our sample with the photometric database MACHO, which provides for each star an 8 years lightcurve. We searched for long, medium, and short-term periodicity and found the eclipsing binaries in our sample. For these stars, combining, spectroscopy and photometry, we were able to provide information on several systems of stars (systemic velocities, ratios of masses, etc). We also present the ratios of B-binaries to B-non binaries in the LMC/SMC in comparison with the MW. Note that this ratio is also an important issue to understand the mechanism of star-formation at low metallicity. We also found the first multiperiodic B and Be stars in the SMC, in particular the first SMC Beta Cep and SPB, while, according to the models, pulsations were not foreseen in low metallicity environments, i.e. typically in the SMC. Our results show that the instability strips are shifted towards higher temperatures in comparison with the Milky Way' strips of pulsating B-type stars. By the fact that we found more pulsating Be stars than pulsating B stars in the SMC, it seems that the fast rotation favours the presence of pulsations. However, the ratio of pulsating B-type stars to "non"-pulsating B-type stars at low metallicity is lower than at high metallicity.Comment: poster IAUS25

    Large spread in the representation of compound long-duration dry and hot spells over Europe in CMIP5

    Get PDF
    Long-duration, sub-seasonal dry spells in combination with high temperature extremes during summer have led to extreme impacts on society and ecosystems in the past. Such events are expected to become more frequent due to increasing temperatures as a result of anthropogenic climate change. However, there is little information on how long-duration dry and hot spells are represented in global climate models (GCMs). In this study, we evaluate 33 CMIP5 (coupled model intercomparison project 5) GCMs in their representation of long-duration dry spells and temperatures during dry spells. We define a dry spell as a consecutive number of days with a daily precipitation of less than 1 mm. CMIP5 models tend to underestimate the persistence of dry spells in northern Europe, while a large variability exists between model estimates in central and southern Europe, where models have contrasting biases. Throughout Europe, we also find a large spread between models in their representation of temperature extremes during dry spells. In central and southern Europe this spread in temperature extremes between models is related to the representation of dry spells, where models that produce longer dry spells also produce higher temperatures, and vice versa. Our results indicate that this variability in model estimates is due to model differences and not internal variability. At latitudes between 50–60∘ N, the differences in the representation of persistent dry spells are strongly related to the representation of persistent anticyclonic systems, such as atmospheric blocking and subtropical ridges. Furthermore, models simulating a higher frequency of anticyclonic systems than ERA5 also simulate temperatures in dry spells that are between 1.4, and 2.8 K warmer than models with a lower frequency in these areas. Overall, there is a large spread between CMIP5 models in their representation of long-duration dry and hot events that is due to errors in the representation of large-scale anticyclonic systems in certain parts of Europe. This information is important to consider when interpreting the plausibility of future projections from climate models and highlights the potential value that improvements in the representation of anticyclonic systems may have for the simulation of impactful hazards.</p

    An evolutionary missing link? A modest-mass early-type galaxy hosting an oversized nuclear black hole

    Get PDF
    SAGE1C J053634.78-722658.5 is a galaxy at redshift z = 0.14, discovered behind the Large Magellanic Cloud in the Spitzer Space Telescope`Surveying the Agents of Galaxy Evolution' Spectroscopy survey. It has very strong silicate emission at 10 μm but negligible far-IR and UV emission. This makes it a candidate for a bare active galactic nuclei (AGN) source in the IR, perhaps seen pole-on, without significant IR emission from the host galaxy. In this paper we present optical spectra taken with the Southern African Large Telescope to investigate the nature of the underlying host galaxy and its AGN. We find broad H α emission characteristic of an AGN, plus absorption lines associated with a mature stellar population (>9 Gyr), and refine its redshift determination to z = 0.1428 ± 0.0001. There is no evidence for any emission lines associated with star formation. This remarkable object exemplifies the need for separating the emission from any AGN from that of the host galaxy when employing IR diagnostic diagrams. We estimate the black hole mass, MBH = 3.5 ± 0.8 × 108 M⊙, host galaxy mass, M_stars=2.5^{2.5}_{1.2}× 10^{10} M⊙, and accretion luminosity, Lbol(AGN) = 5.3 ± 0.4 × 1045 erg s-1 (≈12 per cent of the Eddington luminosity), and find the AGN to be more prominent than expected for a host galaxy of this modest size. The old age is in tension with the downsizing paradigm in which this galaxy would recently have transformed from a star-forming disc galaxy into an early-type, passively evolving galaxy

    Measuring the Development of ICT Skills for Personalized Learning:Developing an Instrument for Dutch Primary Education

    Get PDF
    Our study investigates the development and validation of a questionnaire for competencies learners need to learn in a personalized way using ICT. 9 Dutch schools for primary education collaborate to make personalized learning with ICT evidence-informed. At these 9 iXperium schools, multidisciplinary design teams (consisting of primary school teachers and principals, teachers and students of the teacher-training program of a Dutch university of applied science, researchers from a Dutch university, and external ICT experts) design and research integrated interventions for PL with ICT. We defined personalized learning conditions before filtering the twenty-four learning objectives needed to measure development in personalized learning using ICT. The final questionnaire consists of thirty-three questions to cover the learning objectives. The validity and reliability of our questionary are analyzed in six steps. Cognitive validity (1) and a response model (2) are reported based on literature and a pilot with three iterative rounds of interviews (n=19). Internal constancy (3), confirmatory factor analysis (4), coefficient H (5) are reported after the first run of the questionnaire (n=800), and a test-retest alpha is reported after the second run of the questionnaire (n=800)
    • …
    corecore