99 research outputs found
The effect of three pelleted diets on the survival, growth, and feed conversion of juvenile white grunts (Haemulon plumieri)
The effect of four diets on the survival, growth and feed conversion of juvenile schoolmaster snapper (Lutjanus apodus)
'Support our networking and help us belong!': listening to beginning secondary school science teachers
This study, drawing on the voice of beginning teachers, seeks to illuminate their experiences of building professional relationships as they become part of the teaching profession. A networking perspective was taken to expose and explore the use of others during the first three years of a teacherâs workplace experience. Three case studies, set within a wider sample of 11 secondary school science teachers leaving one UK universityâs PostGraduate Certificate in Education, were studied. The project set out to determine the nature of the networks used by teachers in terms of both how they were being used for their own professional development and perceptions of how they were being used by others in school. Affordances and barriers to networking were explored using notions of identity formation through social participation. The focus of the paper is on how the teachers used others to help shape their sense of belonging to this, their new workplace. The paper develops ideas from network theories to argue that membership of the communities are a subset of the professional interârelationships teachers utilise for their professional development. During their first year of teaching, eight teachers were interviewed, completing 13 semiâstructured interviews. This was supplemented in Year 2 by a questionnaire survey of their experiences. In the third year of the programme, 11 teachers (including the original sample of eight) were surveyed using a network mapping tool in which they represented their communications with people, groups and resources. Finally, three of the teachers (common to both samples) were then interviewed specifically about their networking practices and experiences using the generation of their network map as a stimulated recall focus. The implications of the analysis of these accounts are that these beginning teachers did not perceive of themselves wholly as novices and that their personal aspirations to increase participation in practical science, develop a career or work for pupils holistically did not always sit comfortably with the school communities into which they were being accommodated. While highlighting the importance of trust and respect in establishing relationships, these teachersâ accounts highlight the importance of finding âpeersâ from whom they can find support and with whom they can reflect and potentially collaborate towards developing practice. They also raise questions about who these âpeersâ might be and where they might be found
Oracle-based optimization applied to climate model calibration
In this paper, we show how oracle-based optimization can be effectively used for the calibration of an intermediate complexity climate model. In a fully developed example, we estimate the 12 principal parameters of the C-GOLDSTEIN climate model by using an oracle- based optimization tool, Proximal-ACCPM. The oracle is a procedure that finds, for each query point, a value for the goodness-of-fit function and an evaluation of its gradient. The difficulty in the model calibration problem stems from the need to undertake costly calculations for each simulation and also from the fact that the error function used to assess the goodness-of-fit is not convex. The method converges to a Fbest fit_ estimate over 10 times faster than a comparable test using the ensemble Kalman filter. The approach is simple to implement and potentially useful in calibrating computationally demanding models based on temporal integration (simulation), for which functional derivative information is not readily available
A bright, high rotation-measure FRB that skewers the M33 halo
We report the detection of a bright fast radio burst, FRB\,191108, with
Apertif on the Westerbork Synthesis Radio Telescope (WSRT). The interferometer
allows us to localise the FRB to a narrow 5\arcsec\times7\arcmin ellipse by
employing both multibeam information within the Apertif phased-array feed (PAF)
beam pattern, and across different tied-array beams. The resulting sight line
passes close to Local Group galaxy M33, with an impact parameter of only
18\,kpc with respect to the core. It also traverses the much larger
circumgalactic medium of M31, the Andromeda Galaxy. We find that the shared
plasma of the Local Group galaxies could contribute 10\% of its
dispersion measure of 588\,pc\,cm. FRB\,191108 has a Faraday rotation
measure of +474\,\,rad\,m, which is too large to be explained by
either the Milky Way or the intergalactic medium. Based on the more moderate
RMs of other extragalactic sources that traverse the halo of M33, we conclude
that the dense magnetised plasma resides in the host galaxy. The FRB exhibits
frequency structure on two scales, one that is consistent with quenched
Galactic scintillation and broader spectral structure with
\,MHz. If the latter is due to scattering in the shared
M33/M31 CGM, our results constrain the Local Group plasma environment. We found
no accompanying persistent radio sources in the Apertif imaging survey data
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