991 research outputs found

    Developing Preservice Primary Teachers’ Confidence and Competence in Arts Education using Principles of Authentic Learning.

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    Arts education research over the years has highlighted the situation of non-specialist preservice primary arts teachers as having little confidence in their own artistic ability and their ability to teach the arts to children. Added to this, problems such a lack of resources, confidence, priority, time, knowledge and experience appear to inhibit the regular teaching of the arts by generalist classroom teachers while at the same time, face-to-face hours for preservice primary arts education have decreased significantly over the recent years. This paper describes how one subject within a Primary Teacher Education course responded to these challenges. This subject was based on Herrington, Oliver and Reeves’ (2003) framework for creating authentic learning environments then triangulates this authentic learning framework with what students wanted to learn in the subject and how they perceived they had developed their confidence and competence in creative arts educatio

    A new approach to bad news effects on volatilit y: the multiple-sign-volume sensitive regime EGARCH model (MSV-EGARCH)

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    In this paper, using daily data for six major international stock market indexes and a modified EGARCH specification, the links between stock market returns, volatility and trading volume are investigated in a new nonlinear conditional variance framework with multiple regimes and volume eff ects. Volatility forecast comparisons, using the Harvey-Newbold test for multiple forecasts encompassing, seem to demonstrate that the MSV- EGARCH complex threshold structure is able to correctly fit GARCH- type dynamics of the series under study and dominates competing standard asymmetric models in several of the considered stock indexes.info:eu-repo/semantics/publishedVersio

    Solar Orbiter observations of the Kelvin-Helmholtz waves in the solar wind

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    Context. The Kelvin-HeImholtz (KH) instability is a nonlinear shear-driven instability that develops at the interface between shear flows in plasmas. KH waves have been inferred in various astrophysical plasmas, and have been observed in situ at the magnetospheric boundaries of solar-system planets and through remote sensing at the boundaries of coronal mass ejections. // Aims. KH waves are also expected to develop at flow shear interfaces in the solar wind. While they were hypothesized to play an important role in the mixing of plasmas and in triggering solar wind fluctuations, their direct and unambiguous observation in the solar wind was still lacking. // Methods. We report in-situ observations of quasi-periodic magnetic and velocity field variations plausibly associated with KH waves using Solar Orbiter during its cruise phase. They are found in a shear layer in the slow solar wind in the close vicinity of the Heliospheric Current Sheet. Analysis is performed to derive the local configuration of the waves. A 2-D MHD simulation is also set up with approximate empirical values to test the stability of the shear layer. In addition, magnetic spectra of the event are analyzed. Results. We find that the observed conditions satisfy the KH instability onset criterion from the linear theory analysis, and its de- velopment is further confirmed by the simulation. The current sheet geometry analyses are found to be consistent with KH wave development, albeit with some limitations likely owing to the complex 3D nature of the event and solar wind propagation. Addition- ally, we report observations of an ion jet consistent with magnetic reconnection at a compressed current sheet within the KH wave interval. The KH activity is found to excite magnetic and velocity fluctuations with power law scalings that approximately follow k−5/3 and k−2.8 in the inertial and dissipation ranges, respectively. Finally, we discuss reasons for the lack of in-situ KH wave detection in past data. // Conclusions. These observations provide robust evidence of KH wave development in the solar wind. This sheds new light on the process of shear-driven turbulence as mediated by the KH waves with implications for the driving of solar wind fluctuations

    Flux rope and dynamics of the heliospheric current sheet Study of the Parker Solar Probe and Solar Orbiter conjunction of June 2020

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    Context: Solar Orbiter and Parker Solar Probe jointly observed the solar wind for the first time in June 2020, capturing data from very different solar wind streams: calm, Alfvénic wind and also highly dynamic large-scale structures. Context. Our aim is to understand the origin and characteristics of the highly dynamic solar wind observed by the two probes, particularly in the vicinity of the heliospheric current sheet (HCS). Methods: We analyzed the plasma data obtained by Parker Solar Probe and Solar Orbiter in situ during the month of June 2020. We used the Alfvén-wave turbulence magnetohydrodynamic solar wind model WindPredict-AW and we performed two 3D simulations based on ADAPT solar magnetograms for this period. Results: We show that the dynamic regions measured by both spacecraft are pervaded by flux ropes close to the HCS. These flux ropes are also present in the simulations, forming at the tip of helmet streamers, that is, at the base of the heliospheric current sheet. The formation mechanism involves a pressure-driven instability followed by a fast tearing reconnection process. We further characterize the 3D spatial structure of helmet streamer born flux ropes, which appears in the simulations to be related to the network of quasi-separatrices

    Establishing Diagnostic Criteria for Degenerative Cervical Myelopathy [AO Spine RECODE-DCM Research Priority Number 3].

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    STUDY DESIGN: Narrative review. OBJECTIVES: To discuss the importance of establishing diagnostic criteria in Degenerative Cervical Myelopathy (DCM), including factors that must be taken into account and challenges that must be overcome in this process. METHODS: Literature review summarising current evidence of establishing diagnostic criteria for DCM. RESULTS: Degenerative Cervical Myelopathy (DCM) is characterised by a degenerative process of the cervical spine resulting in chronic spinal cord dysfunction and subsequent neurological disability. Diagnostic delays lead to progressive neurological decline with associated reduction in quality of life for patients. Surgical decompression may halt neurologic worsening and, in many cases, improves function. Therefore, making a prompt diagnosis of DCM in order to facilitate early surgical intervention is a clinical priority in DCM. CONCLUSION: There are often extensive delays in the diagnosis of DCM. Presently, no single set of diagnostic criteria exists for DCM, making it challenging for clinicians to make the diagnosis. Earlier diagnosis and subsequent specialist referral could lead to improved patient outcomes using existing treatment modalities
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