1,329 research outputs found
The development of the professional values and practice standard in the secondary graduate initial teacher training route in England
The paper reports on a pilot research project to investigate how trainee teachers develop an understanding of the competences that must be reached in the area of professional practice and values , which is one of the standards that needs to be met before the award of Qualified Teacher Status in England. Data were collected from secondary trainee teachers, their placement mentors in schools and university tutors. Data have been interpreted in the context of potential threats to the professionalism of teachers, through the introduction of managerialist influences in public funded education. The main findings are: that trainees think that the most dominant influence on developing understanding of professional values are their school placements ; there were little differences in the responses from four subject areas studied ; mentors and other lead teachers play an important role in the development of understanding of professional values; the grades awarded by mentors when assessing professional practice and values varies between the four subjects studied. The explanation for these findings is complex and is related to the understanding and interpretation of the standard by both mentors and trainee teachers. The findings highlight some of the difficulties in attempting to assess competency standards in an area that is underpinned by values and suggest that initial teacher training can best assist the development of the standard when it is approached in a critical way by all parties.</p
The importance of preventive feedback: inference from observations of the stellar masses and metallicities of Milky Way dwarf galaxies
Dwarf galaxies are known to have remarkably low star formation efficiency due
to strong feedback. Adopting the dwarf galaxies of the Milky Way as a
laboratory, we explore a flexible semi-analytic galaxy formation model to
understand how the feedback processes shape the satellite galaxies of the Milky
Way. Using Markov-Chain Monte-Carlo, we exhaustively search a large parameter
space of the model and rigorously show that the general wisdom of strong
outflows as the primary feedback mechanism cannot simultaneously explain the
stellar mass function and the mass--metallicity relation of the Milky Way
satellites. An extended model that assumes that a fraction of baryons is
prevented from collapsing into low-mass halos in the first place can be
accurately constrained to simultaneously reproduce those observations. The
inference suggests that two different physical mechanisms are needed to explain
the two different data sets. In particular, moderate outflows with weak halo
mass dependence are needed to explain the mass--metallicity relation, and
prevention of baryons falling into shallow gravitational potentials of low-mass
halos (e.g. "pre-heating") is needed to explain the low stellar mass fraction
for a given subhalo mass.Comment: 14 pages, 4 figures, accepted for publication in Ap
The connection between the host halo and the satellite galaxies of the Milky Way
Many properties of the Milky Way's dark matter halo, including its mass
assembly history, concentration, and subhalo population, remain poorly
constrained. We explore the connection between these properties of the Milky
Way and its satellite galaxy population, especially the implication of the
presence of the Magellanic Clouds for the properties of the Milky Way halo.
Using a suite of high-resolution -body simulations of Milky Way-mass halos
with a fixed final Mvir ~ 10^{12.1}Msun, we find that the presence of
Magellanic Cloud-like satellites strongly correlates with the assembly history,
concentration, and subhalo population of the host halo, such that Milky
Way-mass systems with Magellanic Clouds have lower concentration, more rapid
recent accretion, and more massive subhalos than typical halos of the same
mass. Using a flexible semi-analytic galaxy formation model that is tuned to
reproduce the stellar mass function of the classical dwarf galaxies of the
Milky Way with Markov-Chain Monte-Carlo, we show that adopting host halos with
different mass-assembly histories and concentrations can lead to different
best-fit models for galaxy-formation physics, especially for the strength of
feedback. These biases arise because the presence of the Magellanic Clouds
boosts the overall population of high-mass subhalos, thus requiring a different
stellar-mass-to-halo-mass ratio to match the data. These biases also lead to
significant differences in the mass--metallicity relation, the kinematics of
low-mass satellites, the number counts of small satellites associated with the
Magellanic Clouds, and the stellar mass of Milky Way itself. Observations of
these galaxy properties can thus provide useful constraints on the properties
of the Milky Way halo.Comment: 20 pages, 12 figures, accepted for publication in ApJ. A new section
on the effect of host halo mass-assembly history on the central galaxy
stellar mass is adde
Naming the parts: a case-study of a gender equality initiative with academic women
YesThis paper aims to seek to contribute to current debates about the effectiveness of different types of gender equality interventions in the academic context. This paper presents an argument for the need to move beyond an individual-structural dichotomy in how such interventions are perceived. The paper draws on an action-research case-study, the Through the Glass Ceiling project, to challenge the idea that “individual”/single-actor interventions serve only to reinforce underlying inequalities by attempting to “fix the women”.It is suggested that actions that support women in their careers have the potential to achieve a degree of transformation at individual, cultural and structural levels when such actions are designed with an understanding of how individuals embody the gendered and gendering social structures and values that are constantly being produced and reproduced within society and academia. The case study highlights the benefits of supporting individuals as gendered actors in gendering institutions and of facilitating the development of critical gender awareness, suggesting that such interventions are most effective when undertaken as part of an integrated institutional equality agenda. By calling attention to the ongoing mutual construction of actors and practices in organizations, this paper seeks to make both a conceptual contribution to how we understand the (re)production and potential transformation of gender relations in academia and to influence wider policy dialogues on diversity at work.FP
The mass assembly of galaxy groups and the evolution of the magnitude gap
We investigate the assembly of groups and clusters of galaxies using the
Millennium dark matter simulation and the associated gas simulations and
semi-analytic catalogues of galaxies. In particular, in order to find an
observable quantity that could be used to identify early-formed groups, we
study the development of the difference in magnitude between their brightest
galaxies to assess the use of magnitude gaps as possible indicators. We select
galaxy groups and clusters at redshift z=1 with dark matter halo mass M(R200) >
1E13/h Msun, and trace their properties until the present time (z=0). We
consider only the systems with X-ray luminosity L_X> 0.25E42/h^2 erg/s at z=0.
While it is true that a large magnitude gap between the two brightest galaxies
of a particular group often indicates that a large fraction of its mass was
assembled at an early epoch, it is not a necessary condition. More than 90% of
fossil groups defined on the basis of their magnitude gaps (at any epoch
between 0<z<1) cease to be fossils within 4 Gyr, mostly because other massive
galaxies are assembled within their cores, even though most of the mass in
their haloes might have been assembled at early times. We show that, compared
to the conventional definition of fossil galaxy groups based on the magnitude
gap Delta m(12)> 2 (in the R-band, within 0.5R200 of the centre of the group),
an alternative criterion Delta m(14)>2.5 (within the same radius) finds 50%
more early-formed systems, and those that on average retain their fossil phase
longer. However, the conventional criterion performs marginally better at
finding early-formed groups at the high-mass end of groups. Nevertheless, both
criteria fail to identify a majority of the early-formed systems.Comment: 16 pages, 11 figures, 2 tables. Accepted for publication in MNRA
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