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Learning & teaching in sociology - a report by the British Sociological Association
The following discussion around issues in learning and teaching is based on data collected during four focus groups with sociologists currently employed in a variety of ‘post 92’ universities in England. The participants were either employed within sociology departments or taught sociology to students studying degrees in different areas. The participants are coded with a letter to represent their focus group (A-D) and a number. While this is certainly not a representative sample there are a variety of interesting discussions and comments that help to inform a broad discussion about issues in learning and teaching. Any conclusions must be contextualised by the limited nature of the sample that is presented here. We have tried to reflect the main themes that reoccurred across the meetings. In order to capture some of the nuance and details of comments and ideas that the participants offered, extended quotes are often used. There are six overlapping sections that follow the format of the key questions that each focus group was asked to consider
A Comparison of Near-Infrared Photometry and Spectra for Y Dwarfs with a New Generation of Cool Cloudy Models
We present YJHK photometry, or a subset, for the six Y dwarfs discovered in
WISE data by Cushing et al.. The data were obtained using NIRI on the Gemini
North telescope. We also present a far-red spectrum obtained using GMOS-North
for WISEPC J205628.90+145953.3. We compare the data to Morley et al. (2012)
models, which include cloud decks of sulfide and chloride condensates. We find
that the models with these previously neglected clouds can reproduce the energy
distributions of T9 to Y0 dwarfs quite well, other than near 5um where the
models are too bright. This is thought to be because the models do not include
departures from chemical equilibrium caused by vertical mixing, which would
enhance the abundance of CO, decreasing the flux at 5um. Vertical mixing also
decreases the abundance of NH_3, which would otherwise have strong absorption
features at 1.03um and 1.52um that are not seen in the Y0 WISEPC
J205628.90+145953.3. We find that the five Y0 to Y0.5 dwarfs have 300 < T_eff K
< 450, 4.0 < log g < 4.5 and f_sed ~ 3. These temperatures and gravities imply
a mass range of 5 - 15 M_Jupiter and ages around 5 Gyr. We suggest that WISEP
J182831.08+265037.8 is a binary system, as this better explains its luminosity
and color. We find that the data can be made consistent with observed trends,
and generally consistent with the models, if the system is composed of a T_eff
= 325 K and log g ~ 4.0
secondary, corresponding to masses of 10 and 7 M_Jupiter and an age around 2
Gyr. If our deconvolution is correct, then the T_eff = 300 K cloud-free model
fluxes at K and W2 are too faint by 0.5 - 1.0 magnitudes. We will address this
discrepancy in our next generation of models, which will incorporate water
clouds and mixing.Comment: 39 pages, 10 Figures, 8 Tables. Accepted by ApJ. This revision
replaces Figures 9 and 10 with B & W versions, corrects figure captions for
color online only, corrects references. Text is unchanged. Tables 3, 4 and 8
are available at http://www.gemini.edu/staff/sleggett, other model data are
available at http://www.ucolick.org/~cmorley/cmorley/Data.htm
Emergence in genetic programming:let's exploit it!
Banzhaf explores the concept of emergence and how and where it happens in genetic programming [1]. Here we consider the question: what shall we do with it? We argue that given our ultimate goal to produce genetic programming systems that solve new and difficult problems, we should take advantage of emergence to get closer to this goal
High temperature condensate clouds in super-hot Jupiter atmospheres
Deciphering the role of clouds is central to our understanding of exoplanet
atmospheres, as they have a direct impact on the temperature and pressure
structure, and observational properties of the planet. Super-hot Jupiters
occupy a temperature regime similar to low mass M-dwarfs, where minimal cloud
condensation is expected. However, observations of exoplanets such as WASP-12b
(Teq ~ 2500 K) result in a transmission spectrum indicative of a cloudy
atmosphere. We re-examine the temperature and pressure space occupied by these
super-hot Jupiter atmospheres, to explore the role of the initial Al- and
Ti-bearing condensates as the main source of cloud material. Due to the high
temperatures a majority of the more common refractory material is not depleted
into deeper layers and would remain in the vapor phase. The lack of depletion
into deeper layers means that these materials with relatively low cloud masses
can become significant absorbers in the upper atmosphere. We provide
condensation curves for the initial Al- and Ti-bearing condensates that may be
used to provide quantitative estimates of the effect of metallicity on cloud
masses, as planets with metal-rich hosts potentially form more opaque clouds
because more mass is available for condensation. Increased metallicity also
pushes the point of condensation to hotter, deeper layers in the planetary
atmosphere further increasing the density of the cloud. We suggest that planets
around metal-rich hosts are more likely to have thick refractory clouds, and
discuss the implication on the observed spectra of WASP-12b.Comment: Accepted for publication in MNRAS, 10 pages, 1 table, 5 figure
Theory and practice of optimal mutation rate control in Hamming spaces of DNA sequences
We investigate the problem of optimal control of mutation by asexual self-replicating organisms represented by points in a metric space. We introduce the notion of a relatively monotonic fitness landscape and consider a generalisation of Fisher's geometric model of adaptation for such spaces. Using a Hamming space as a prime example, we derive the probability of adaptation as a function of reproduction parameters (e.g. mutation size or rate). Optimal control rules for the parameters are derived explicitly for some relatively monotonic landscapes, and then a general information-based heuristic is introduced. We then evaluate our theoretical control functions against optimal mutation functions evolved from a random population of functions using a meta genetic algorithm. Our experimental results show a close match between theory and experiment. We demonstrate this result both in artificial fitness landscapes, defined by a Hamming distance, and a natural landscape, where fitness is defined by a DNA-protein affinity. We discuss how a control of mutation rate could occur and evolve in natural organisms. We also outline future directions of this work
Monotonicity of fitness landscapes and mutation rate control
A common view in evolutionary biology is that mutation rates are minimised. However, studies in combinatorial optimisation and search have shown a clear advantage of using variable mutation rates as a control parameter to optimise the performance of evolutionary algorithms. Much biological theory in this area is based on Ronald Fisher's work, who used Euclidean geometry to study the relation between mutation size and expected fitness of the offspring in infinite phenotypic spaces. Here we reconsider this theory based on the alternative geometry of discrete and finite spaces of DNA sequences. First, we consider the geometric case of fitness being isomorphic to distance from an optimum, and show how problems of optimal mutation rate control can be solved exactly or approximately depending on additional constraints of the problem. Then we consider the general case of fitness communicating only partial information about the distance. We define weak monotonicity of fitness landscapes and prove that this property holds in all landscapes that are continuous and open at the optimum. This theoretical result motivates our hypothesis that optimal mutation rate functions in such landscapes will increase when fitness decreases in some neighbourhood of an optimum, resembling the control functions derived in the geometric case. We test this hypothesis experimentally by analysing approximately optimal mutation rate control functions in 115 complete landscapes of binding scores between DNA sequences and transcription factors. Our findings support the hypothesis and find that the increase of mutation rate is more rapid in landscapes that are less monotonic (more rugged). We discuss the relevance of these findings to living organisms
Liquidus Phases of the Richardson H5 Chondrite at High Pressures and Temperatures
Part of early mantle evolution may include a magma ocean, where core formation began before the proto-Earth reached half of its present radius. Temperatures were high and bombardment and accretion were still occurring, suggesting that the proto-Earth consisted of a core and an at least partially liquid mantle, the magma ocean. As the Earth accreted, pressure near the core increased and the magma ocean decreased in volume and became shallower as it began to cool and solidify. As crystals settled, or floated, the composition of the magma ocean could change significantly and begin to crystallize different minerals from the residual liquid. Therefore, the mantle may be stratified following the P-T phase diagram for the bulk silicate Earth. To understand mantle evolution, it is necessary to know liquidus phase relations at high pressures and temperatures. In order to model the evolution of the magma ocean, high pressure and temperature experiments have been conducted to simulate the crystallization process using a range of materials that most likely resemble the bulk composition of the early Earth
Family preferences for home or hospital care at diagnosis for children with diabetes in the DECIDE study.
This is the final version of the article. Available from Wiley via the DOI in this record.AIMS: A diagnosis of Type 1 diabetes in childhood can be a difficult life event for children and families. For children who are not severely ill, initial home rather than hospital-based care at diagnosis is an option although there is little research on which is preferable. Practice varies widely, with long hospital stays in some countries and predominantly home-based care in others. This article reports on the comparative acceptability and experience of children with Type 1 diabetes and their parents taking part in the DECIDE study evaluating outcomes of home or hospital-based treatment from diagnosis in the UK. METHODS: Semi-structured interviews with 11 (pairs of) parents and seven children were conducted between 15 and 20 months post diagnosis. Interviewees were asked about adaptation to, management and impact of the diabetes diagnosis, and their experience of initial post-diagnosis treatment. RESULTS: There were no differences between trial arms in adaptation to, management of or impact of diabetes. Most interviewees wanted to be randomized to the 'home' arm initially but expressed a retrospective preference for whichever trial arm they had been in, and cited benefits relating to learning about diabetes management. CONCLUSIONS: The setting for early treatment did not appear to have a differential impact on families in the long term. However, the data presented here describe different experiences of early treatment settings from the perspective of children and their families, and factors that influenced how families felt initially about treatment setting. Further research could investigate the short-term benefits of both settings.National Institute for Social Care and Health Research Clinical Research Centr
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