17 research outputs found

    Entwicklung und Evaluation einer LehrkrÀftefortbildung zur Planung von selbstgesteuerten Experimenten (Volume 319)

    Get PDF
    Das selbstgesteuerte Experimentieren ist laut den nationalen Bildungsstandards sowie den LehrplĂ€nen im Fach Chemie ein wichtiger Bestandteil der naturwissenschaftlichen Schulbildung. Offene Experimentierformen sind jedoch wenig etabliert. Um das selbstgesteuerte Experimentieren in die Unterrichtspraxis zu implementieren, wurde im Rahmen dieses Forschungsprojekts eine eintĂ€gige LehrkrĂ€ftefortbildung zur Konzeption von selbstgesteuerten Experimenten im Chemieunterricht durchgefĂŒhrt. Dazu wurde ein literaturbasiertes Strukturierungskonzept entwickelt, mit dem die LehrkrĂ€fte kochbuchartige Schulversuche zu selbstgesteuerten und kompetenzorientierten Experimenten mit beliebigen Öffnungsgraden modifizieren können. Begleitend zur Fortbildung wurde im PrĂ€-Post-Follow-Up-Design das fachdidaktische Wissen der Teilnehmenden hinsichtlich der Planung von selbstgesteuerten Experimenten empirisch ĂŒberprĂŒft. Zur Erfassung dieses Konstrukts wurde ein neues Messinstrument literaturbasiert entwickelt und die GĂŒte des Messinstruments evaluiert. Die Auswertungen zeigen, dass die Fortbildung hinsichtlich des fachdidaktischen Wissens der LehrkrĂ€fte kurz- sowie langfristig lernförderlich ist und die Fortbildung von den Teilnehmenden positiv bewertet wird. Die ReliabilitĂ€tsanalyse sowie die Validierungsstudie zeigen, dass der Test sowohl reliabel als auch valide ist. In Folgestudien könnte die langfristige VerhaltensĂ€nderung der LehrkrĂ€fte bezĂŒglich der Implementierung des selbstgesteuerten Experimentierens in den Unterricht untersucht werden

    Development of an instrument to assess early number concept development in four South African languages

    Get PDF
    A recently published interview-based test, known by its partly German acronym, MARKO-D SA, is introduced in this article by way of a narrative of its development through various cycles of research. The 48-item test, in 4 South African languages, captures number concept development of children in the 6 to 8-year age group. The authors present their argument for the South African versioning and translation of the test for this country, where there is a dearth of suitable assessment instruments for gauging young children’s mathematical concept development. We also present the findings of the research that was conducted to standardise and norm the local version of the test, along with our reasoning about the theoretical strength of the conceptual model that undergirds the test

    Active galactic nucleus jet feedback in hydrostatic halos

    Full text link
    Feedback driven by jets from active galactic nuclei is believed to be responsible for reducing cooling flows in cool-core galaxy clusters. We use simulations to model feedback from hydrodynamic jets in isolated halos. While the jet propagation converges only after the diameter of the jet is well resolved, reliable predictions about the effects these jets have on the cooling time distribution function only require resolutions sufficient to keep the jet-inflated cavities stable. Comparing different model variations, as well as an independent jet model using a different hydrodynamics code, we show that the dominant uncertainties are the choices of jet properties within a given model. Independent of implementation, we find that light, thermal jets with low momentum flux tend to delay the onset of a cooling flow more efficiently on a 5050 Myr timescale than heavy, kinetic jets. The delay of the cooling flow originates from a displacement and boost in entropy of the central gas. If the jet luminosity depends on accretion rate, collimated, light, hydrodynamic jets are able to reduce cooling flows in halos, without a need for jet precession or wide opening angles. Comparing the jet feedback with a `kinetic wind' implementation shows that equal amounts of star formation rate reduction can be achieved by different interactions with the halo gas: the jet has a larger effect on the hot halo gas while leaving the denser, star forming phase in place, while the wind acts more locally on the star forming phase, which manifests itself in different time-variability properties.Comment: 21 pages, 20 figures, submitted to MNRAS, comments welcom

    Brain stem tumors in children less than 3 months: clinical and radiologic findings of a rare disease

    Get PDF
    Purpose Brain stem tumors in children < 3 months at diagnosis are extremely rare. Our aim is to study a retrospective cohort to improve the understanding of the disease course and guide patient management. Methods This is a multicenter retrospective analysis across the European Society for Pediatric Oncology SIOP-E HGG/DIPG Working Group linked centers, including patients with a brainstem tumor diagnosed between 2009 and 2020 and aged < 3 months at diagnosis. Clinical data were collected, and imaging characteristics were analyzed blindly and independently by two neuroradiologists. Results Five cases were identified. No patient received any therapy. The epicenter of two tumors was in the medulla oblongata alone and in the medulla oblongata and the pons in three. For patients with tumor in equal parts in the medulla oblongata and the pons (n = 3), the extension at diagnosis involved the spinal cord; for the two patients with the tumor epicenter in the medulla oblongata alone (n = 2), the extension at diagnosis included the pons (n = 2) and the spinal cord (n = 1). Biopsy was performed in one patient identifying a pilocytic astrocytoma. Two patients died. In one patient, autopsy revealed a high-grade glioma (case 3). Three survivors showed either spontaneous tumor regression (n = 2) or stable disease (n = 1). Survivors were followed up for 10, 7, and 0.6 years, respectively. One case had the typical imaging characteristics of a dorsal exophytic low-grade glioma. Conclusions No patient fulfilled the radiologic criteria defining a high-grade glioma. Central neuroradiological review and biopsy may provide useful information regarding the patient management

    ETMR-01. Brain stem tumors in children less than three months: clinical and radiologic findings of a rare disease [Abstract]

    Get PDF
    BACKGROUND Brainstem gliomas account for 10-20% of all central nervous system pediatric neoplasms. Brain stem tumors in children less than three months old at diagnosis are extremely rare. Our aim is to study a retrospective cohort to improve the understanding of the disease course and guide patient management. METHODS This is a multicenter retrospective analysis across the European Society for Pediatric Oncology SIOP-E HGG/DIPG Working Group linked centers and included patients with a brainstem tumor diagnosed between 2009 and 2020 and aged less than 3 months at diagnosis. Clinical data was collected, and imaging characteristics were analyzed blindly and independently by two experienced neuroradiologists. RESULTS Five cases (female; n=4) were identified of which no patient received any therapy. The epicenter of 2 tumors was in the medulla oblongata alone and in the medulla oblongata and the pons in 3 cases. For patients with tumor in equal parts in the medulla oblongata and the pons (n=3) the extension at diagnosis involved the spinal cord; for the 2 patients with the tumor epicenter in the medulla oblongata alone (n=2) the extension at diagnosis included the pons (n=2) and the spinal cord (n=1). Biopsy was performed in one patient identifying a pilocytic astrocytoma. Two patients died rapidly. In one patient autopsy revealed a high-grade glioma (case 3). Three survivors showed either spontaneous tumor regression (n=2) or stable disease (n=1). The surviving patients were followed-up for 10, 7, and 0.6 years, respectively. One case had the typical imaging characteristics of a dorsal exophytic low-grade glioma. CONCLUSIONS No patient fulfilled the radiologic criteria defining a high-grade glioma. Central neuroradiological review and biopsy (if feasible) may provide useful information with regards to the patient’s management

    Multidisciplinary perspectives on automatic analysis of children's language samples : where do we go from here?

    Get PDF
    BACKGROUND : Language sample analysis (LSA) is invaluable to describe and understand child language use and development for clinical purposes and research. Digital tools supporting LSA are available, but many of the LSA steps have not been automated. Nevertheless, programs that include automatic speech recognition (ASR), the first step of LSA, have already reached mainstream applicability. SUMMARY : To better understand the complexity, challenges, and future needs of automatic LSA from a technological perspective, including the tasks of transcribing, annotating, and analysing natural child language samples, this article takes on a multidisciplinary view. Requirements of a fully automated LSA process are characterized, features of existing LSA software tools compared, and prior work from the disciplines of information science and computational linguistics reviewed. KEY MESSAGES : Existing tools vary in their extent of automation provided across the process of LSA. Advances in machine learning for speech recognition and processing have potential to facilitate LSA, but the specifics of child speech and language as well as the lack of child data complicate software design. A transdisciplinary approach is recommended as feasible to support future software development for LSA.https://karger.com/fplhj2023Centre for Augmentative and Alternative Communication (CAAC)Speech-Language Pathology and Audiolog

    Entwicklung und Evaluation einer LehrkrÀftefortbildung zur Planung von selbstgesteuerten Experimenten (Volume 319)

    No full text
    Das selbstgesteuerte Experimentieren ist laut den nationalen Bildungsstandards sowie den LehrplĂ€nen im Fach Chemie ein wichtiger Bestandteil der naturwissenschaftlichen Schulbildung. Offene Experimentierformen sind jedoch wenig etabliert. Um das selbstgesteuerte Experimentieren in die Unterrichtspraxis zu implementieren, wurde im Rahmen dieses Forschungsprojekts eine eintĂ€gige LehrkrĂ€ftefortbildung zur Konzeption von selbstgesteuerten Experimenten im Chemieunterricht durchgefĂŒhrt. Dazu wurde ein literaturbasiertes Strukturierungskonzept entwickelt, mit dem die LehrkrĂ€fte kochbuchartige Schulversuche zu selbstgesteuerten und kompetenzorientierten Experimenten mit beliebigen Öffnungsgraden modifizieren können. Begleitend zur Fortbildung wurde im PrĂ€-Post-Follow-Up-Design das fachdidaktische Wissen der Teilnehmenden hinsichtlich der Planung von selbstgesteuerten Experimenten empirisch ĂŒberprĂŒft. Zur Erfassung dieses Konstrukts wurde ein neues Messinstrument literaturbasiert entwickelt und die GĂŒte des Messinstruments evaluiert. Die Auswertungen zeigen, dass die Fortbildung hinsichtlich des fachdidaktischen Wissens der LehrkrĂ€fte kurz- sowie langfristig lernförderlich ist und die Fortbildung von den Teilnehmenden positiv bewertet wird. Die ReliabilitĂ€tsanalyse sowie die Validierungsstudie zeigen, dass der Test sowohl reliabel als auch valide ist. In Folgestudien könnte die langfristige VerhaltensĂ€nderung der LehrkrĂ€fte bezĂŒglich der Implementierung des selbstgesteuerten Experimentierens in den Unterricht untersucht werden

    A mathematics competence test for Grade 1 children migrates from Germany to South Africa

    No full text
    This article presents the translation and adaptation process of a mathematics test for the acquisition of key mathematical (arithmetic) concepts by children from four to eight years of age. The origin of this test was in Germany, whence it was sourced by researchers at the University of Johannesburg. A conceptual model of hierarchical mathematics competence development forms the theoretical foundation of the test. This notion of hierarchical competence was tested in a one-dimensional Rasch analysis, which confirmed the hierarchical structure of the test with five levels of ability. In the translation process, it was imperative to ascertain whether the items of the translation had retained the conceptual content of the original test and had been allocated to the same conceptual levels as in the original test. In a number of pilot studies with a total of 1 600 South African children, we focused on the items that had been allocated to a different level, aiming to find out whether this was the result of translation errors. In analyses of different samples, discussing and reflecting on the model fit, and especially on items that did not fit well, ‘misfitting’ items could mostly be attributed to translation difficulties and differences in the children’s strategies, and not to a generally altered model. The final model was established after the rephrasing of critical items. This model has already been tested with 500 additional South African children. Results are presented and discussed, with the focus on the Sesotho test results
    corecore