891 research outputs found
Recruiting the ‘quality teacher’: equity, faith, and passion
The figure of the teacher is becoming increasingly significant in schooling systems around the globe. In this article, we consider how the market-oriented system of schooling in the Australian state of New South Wales may be reflecting and (re)shaping understandings of who teachers are and should be. To do this, we present a corpus-assisted analysis of advertisements for teaching positions gathered across the public, Catholic and independent school sectors, to explore how schools and school sectors construct images of the ‘good’ or ‘quality’ teacher. Findings indicate a stronger focus on the ‘person’ of the teacher in independent schools; and a surprising lack of pedagogical concerns within any sector. Our contribution is novel in first, using a relatively untapped data source to explore how the figure of the teacher is constructed in the public domain; and second, demonstrating the reciprocal relationship between teachers and schools in the marketing of educational products
Rotas alternativas e caminhos para a identidade profissional dos professores: Explorando as diversas identidades dos membros Teach For America
Research on the development of professional identity for teachers who enter the profession through alternative routes is still in its infancy. In contrast to their peers who complete traditional initial teacher education programs, these teachers are exposed to different conditions and constraints that produce a range of sub-identities previously unidentified in the literature. This paper draws on interviews with 27 teachers who entered teaching through Teach For America and wrestled with these sub-identities as they considered their emerging professional identity. We argue that these sub-identities point to structural challenges embedded within Teach for America, and we highlight the need for additional research on the growing cadre of teachers entering the teaching profession through alternative routes, and subsequently influencing policymaking processes.La investigación sobre el desarrollo de la identidad profesional de los maestros que ingresan a la profesión a través de vías alternativas todavía está en su infancia. A diferencia de sus colegas que completan los programas tradicionales de formación docente inicial, estos maestros están expuestos a diferentes condiciones y limitaciones que producen una multitud de identidades no identificadas previamente en la literatura. Esta investigación se basa en entrevistas con 27 maestros que ingresaron a la enseñanza a través de Teach For America y lucharon con estas subidentidades cuando consideraban su identidad profesional emergente. Presentamos argumentos que estas subidentidades apuntan a desafíos estructurales integrados en Teach for America, y destacamos la necesidad de investigación adicional sobre el creciente grupo de profesores que ingresan a la profesión docente a través de rutas alternativas, y que posteriormente influyen en los procesos de formulación de pólitica.A pesquisa sobre o desenvolvimento da identidade profissional dos professores que entram na profissão através de meios alternativos ainda está em sua infância. Ao contrário de seus colegas que completam os tradicionais programas iniciais de treinamento de professores, esses professores estão expostos a diferentes condições e limitações que produzem uma multiplicidade de identidades não identificadas anteriormente na literatura. Esta pesquisa é baseada em entrevistas com 27 professores que entraram no ensino por Teach For America e lutaram com essas subidências quando consideraram sua identidade profissional emergente. Apresentamos argumentos de que essas subentendências apontam para desafios estruturais integrados no Teach for America e destacamos a necessidade de pesquisas adicionais sobre o crescente grupo de professores que entram na profissão docente através de rotas alternativas e que posteriormente influenciam os processos de formulação de pólitica
Teachers' orientations to educational research and data in England and Australia: implications for teacher professionalism
Teachers’ engagement with and understanding of educational research and data is an increasing concern for policy-makers around the globe. With unprecedented access to, and new forms of, ‘data’ in schools, concerns for its ‘best practice’ use in classroom decision-making have come to the fore. In academic spaces, these developments have also been of concern due to what such pushes for ‘evidence-based practice’ may elide in terms of teacher knowledge and professionalism. In this article, we present findings from two national contexts, England and Australia, in order to explore how teachers understand themselves and their work in relation to educational data and research. We find that, despite highly engaged samples across contexts who place considerable importance on such research and data, respondents do not report an equal sense of capacity across the various forms which they may take. Particular limitations are identified in relation to action research. We argue that these results have consequences for the development of a ‘mature’ profession that goes beyond performative forms of professionalism and towards those of a ‘research-rich’ culture of trust
Researching teachers’ time use: Complexity, challenges and a possible way forward
In the context of global concerns about teacher workload and the relationship between workload and attrition, understanding the nature, quantity and intensity of teachers’ work is an essential first step in formulating robust solutions to this significant problem. Understanding teachers’ work, however, is a complex undertaking, and prior attempts have largely been focused on the quantity rather than the intensity or quality of work required and undertaken. This article reports on a pilot study of the Teacher Time Use app, a bespoke tool developed by the research team to ‘get inside’ teachers’ subjective experience of time through a focus on both workload and intensity. Our analysis shows that the app provides a simple, non-demanding way for teachers to record their work in a timely and efficient way. It also highlights the capacity of this approach to understand both the range and quantum of tasks that comprise teachers’ work and consequently the nature and subjective experience of work intensification. We argue the need for a more nuanced empirical understanding of the layering and multi-tasking of teachers’ work that characterises work intensity, and suggest that the Teachers’ Time Use app provides an effective means for recording and representing the complex dimensions of teachers’ work and time use
A luminosity distribution for kilonovae based on short gamma-ray burst afterglows
The combined detection of a gravitational-wave signal, kilonova, and short
gamma-ray burst (sGRB) from GW170817 marked a scientific breakthrough in the
field of multi-messenger astronomy. But even before GW170817, there have been a
number of sGRBs with possible associated kilonova detections. In this work, we
re-examine these "historical" sGRB afterglows with a combination of
state-of-the-art afterglow and kilonova models. This allows us to include
optical/near-infrared synchrotron emission produced by the sGRB as well as
ultraviolet/optical/near-infrared emission powered by the radioactive decay of
-process elements (i.e., the kilonova). Fitting the lightcurves, we derive
the velocity and the mass distribution as well as the composition of the
ejected material. The posteriors on kilonova parameters obtained from the fit
were turned into distributions for the peak magnitude of the kilonova emission
in different bands and the time at which this peak occurs. From the sGRB with
an associated kilonova, we found that the peak magnitude in H bands falls in
the range [-16.2, -13.1] ( of confidence) and occurs within after the sGRB prompt emission. In g band instead we obtain a peak
magnitude in range [-16.8, -12.3] occurring within the first after
the sGRB prompt. From the luminosity distributions of GW170817/AT2017gfo,
kilonova candidates GRB130603B, GRB050709 and GRB060614 (with the possible
inclusion of GRB150101B) and the upper limits from all the other sGRBs not
associated with any kilonova detection we obtain for the first time a kilonova
luminosity function in different bands.Comment: Published in MNRAS, 24 pages, 14 figure
Radiative Emission Mechanisms of Tidal Disruption Events
We describe how the various outcomes of stellar tidal disruption give rise to
observable radiation. We separately consider the cases where gas circularizes
rapidly into an accretion disc, as well as the case when shocked debris streams
provide the observable emission without having fully circularized. For the
rapid circularization case, we describe how outflows, absorption by
reprocessing layers, and Comptonization can cause the observed radiation to
depart from that of a bare disc, possibly giving rise to the observed
optical/UV emission along with soft X-rays from the disc. If, instead, most of
the debris follows highly eccentric orbits for a significant time, many
properties of the observed optical/UV emission can be explained by the scale of
those eccentric orbits and the shocks embedded in the debris flow near orbital
apocenter. In this picture, soft X-ray emission at early times results from the
smaller amount of debris mass deflected into a compact accretion disc by weak
shocks near the stellar pericenter. A general proposal for the near-constancy
of the ultraviolet/optical color temperatures is provided, by linking it to
incomplete thermalization of radiation in the atmosphere of the emitting
region. We also briefly discuss the radio signals from the interaction of
unbound debris and jets with the black hole environment.Comment: Accepted for publication in Springer Space Science Reviews. Chapter
in ISSI review "The Tidal Disruption of Stars by Massive Black Holes" vol. 7
Assessing the applicability of the Revised Universal Soil Loss Equation (RUSLE) to Irish Catchments
Elevated suspended sediment concentrations in fluvial environments have important implications for system ecology and even small concentrations may have serious consequences for sensitive ecosystems or organisms, such as freshwater pearl mussels (<i>Margaritifera margaritifera</i>). Informed decision making is therefore required for land managers to understand and control soil erosion and sediment delivery to the river network. However, given that monitoring of sediment fluxes requires financial and human resources which are often limited at a national scale, sediment mobilisation and delivery models are commonly used for sediment yield estimation and management. The Revised Universal Soil Loss Equation (RUSLE) is the most widely used model for overland flow erosion and can, when combined with a sediment delivery ratio (SDR), provide reasonable sediment load estimations for a catchment. This paper presents RUSLE factors established from extant GIS and rainfall datasets that are incorporated into a flexible catchment modelling approach. We believe that this is the first time that results from a RUSLE application at a national scale are tested against measured sediment yield values available from Ireland. An initial assessment of RUSLE applied to Irish conditions indicates an overestimation of modelled sediment yield values for most of the selected catchments. Improved methods for model and SDR factors estimation are needed to account for Irish conditions and catchment characteristics. Nonetheless, validation and testing of the model in this study using observed values is an important step towards more effective sediment yield modelling tools for nationwide applications
MOSFiT: Modular open source fitter for transients
Much of the progress made in time-domain astronomy is accomplished by
relating observational multi-wavelength time series data to models derived from
our understanding of physical laws. This goal is typically accomplished by
dividing the task in two: collecting data (observing), and constructing models
to represent that data (theorizing). Owing to the natural tendency for
specialization, a disconnect can develop between the best available theories
and the best available data, potentially delaying advances in our understanding
new classes of transients. We introduce MOSFiT: the Modular Open-Source Fitter
for Transients, a Python-based package that downloads transient datasets from
open online catalogs (e.g., the Open Supernova Catalog), generates Monte Carlo
ensembles of semi-analytical light curve fits to those datasets and their
associated Bayesian parameter posteriors, and optionally delivers the fitting
results back to those same catalogs to make them available to the rest of the
community. MOSFiT is designed to help bridge the gap between observations and
theory in time-domain astronomy; in addition to making the application of
existing models and creation of new models as simple as possible, MOSFiT yields
statistically robust predictions for transient characteristics, with a standard
output format that includes all the setup information necessary to reproduce a
given result. As large-scale surveys such as LSST discover entirely new classes
of transients, tools such as MOSFiT will be critical for enabling rapid
comparison of models against data in statistically consistent, reproducible,
and scientifically beneficial ways
Evidence of a Massive Stellar Disruption in the X-ray Spectrum of ASASSN-14li
The proximity and duration of the tidal disruption event (TDE) ASASSN-14li
led to the discovery of narrow, blue-shifted absorption lines in X-rays and UV.
The gas seen in X-ray absorption is consistent with bound material close to the
apocenter of elliptical orbital paths, or with a disk wind similar to those
seen in Seyfert-1 active galactic nuclei. We present a new analysis of the
deepest high-resolution XMM-Newton and Chandra spectra of ASASSN-14li. Driven
by the relative strengths of He-like and H-like charge states, the data require
[N/C] > 2.4, in qualitative agreement with UV spectral results. Flows of the
kind seen in the X-ray spectrum of ASASSN-14li were not clearly predicted in
simulations of TDEs; this left open the possibility that the observed
absorption might be tied to gas released in prior AGN activity. However, the
abundance pattern revealed in this analysis points to a single star rather than
a standard AGN accretion flow comprised of myriad gas contributions. The
simplest explanation of the data is likely that a moderately massive star (M ~
3 Msun) with significant CNO processing was disrupted. An alternative
explanation is that a lower mass star was disrupted that had previously been
stripped of its envelope. We discuss the strengths and limitations of our
analysis and these interpretations.Comment: Accepted for publication in ApJ Letter
A multi-organ transcriptome resource for the Burmese Python (Python molurus bivittatus)
<p>Abstract</p> <p>Background</p> <p>Snakes provide a unique vertebrate system for studying a diversity of extreme adaptations, including those related to development, metabolism, physiology, and venom. Despite their importance as research models, genomic resources for snakes are few. Among snakes, the Burmese python is the premier model for studying extremes of metabolic fluctuation and physiological remodelling. In this species, the consumption of large infrequent meals can induce a 40-fold increase in metabolic rate and more than a doubling in size of some organs. To provide a foundation for research utilizing the python, our aim was to assemble and annotate a transcriptome reference from the heart and liver. To accomplish this aim, we used the 454-FLX sequencing platform to collect sequence data from multiple cDNA libraries.</p> <p>Results</p> <p>We collected nearly 1 million 454 sequence reads, and assembled these into 37,245 contigs with a combined length of 13,409,006 bp. To identify known genes, these contigs were compared to chicken and lizard gene sets, and to all Genbank sequences. A total of 13,286 of these contigs were annotated based on similarity to known genes or Genbank sequences. We used gene ontology (GO) assignments to characterize the types of genes in this transcriptome resource. The raw data, transcript contig assembly, and transcript annotations are made available online for use by the broader research community.</p> <p>Conclusion</p> <p>These data should facilitate future studies using pythons and snakes in general, helping to further contribute to the utilization of snakes as a model evolutionary and physiological system. This sequence collection represents a major genomic resource for the Burmese python, and the large number of transcript sequences characterized should contribute to future research in this and other snake species.</p
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