793 research outputs found
Predictive Modelling of Bone Ageing
Bone age assessment (BAA) is a task performed daily by paediatricians in hospitalsworldwide. The main reasons for BAA to be performed are: fi�rstly, diagnosis of growth disorders through monitoring skeletal development; secondly, prediction of final adult height; and fi�nally, verifi�cation of age claims. Manually predicting bone age from radiographs is a di�fficult and time consuming task. This thesis investigates bone age assessment and why automating the process will help. A review of previous automated bone age assessment systems is undertaken and we investigate why none of these systems have gained widespread acceptance. We propose a new automated method for bone age assessment, ASMA (Automated Skeletal Maturity Assessment).
The basic premise of the approach is to automatically extract descriptive shape features that capture the human expertise in forming bone age estimates. The algorithm consists of the following six modularised stages: hand segmentation; hand
segmentation classifi�cation; bone segmentation; feature extraction; bone segmentation classifi�cation; bone age prediction.
We demonstrate that ASMA performs at least as well as other automated systems and that models constructed on just three bones are as accurate at predicting age as expert human assessors using the standard technique. We also investigate the importance of ethnicity and gender in skeletal development. Our conclusion is that the feature based system of separating the image processing from the age modelling is
the best approach, since it off�ers flexibility and transparency, and produces accurate estimates
An evolutionary model with Turing machines
The development of a large non-coding fraction in eukaryotic DNA and the
phenomenon of the code-bloat in the field of evolutionary computations show a
striking similarity. This seems to suggest that (in the presence of mechanisms
of code growth) the evolution of a complex code can't be attained without
maintaining a large inactive fraction. To test this hypothesis we performed
computer simulations of an evolutionary toy model for Turing machines, studying
the relations among fitness and coding/non-coding ratio while varying mutation
and code growth rates. The results suggest that, in our model, having a large
reservoir of non-coding states constitutes a great (long term) evolutionary
advantage.Comment: 16 pages, 7 figure
‘Why am I in all of these pictures?’ From learning stories to lived stories:The politics of children’s participation rights in documentation practices
Caralyn Blaisdell - ORCID: 0000-0002-5491-7346
https://orcid.org/0000-0002-5491-7346In this paper, we report on Phase One of a small action research project that examined how Learning Stories were put into practice at one Scottish nursery. Specifically, the paper looks at young children’s participation rights and how they were enacted within the authorship of the stories. The project used an action research approach in which qualitative data about participants’ current experiences with the stories was used to spark reflection, experimentation and change in documentation practices. Drawing on Phase One data from young children, parents and practitioners at the nursery, our findings illustrate the complex enactment of children’s participation rights, including children’s right to information, freedom of expression and their right to express their views and have those views taken into account. The paper concludes that more work needs to be done in the field of Learning stories to (a) acknowledge the complex political and material considerations at play in the creation of pedagogical documentation and (b) to accommodate children’s own authorship, through flexible, non (or less) written methods.The research was funded by The Froebel Trust: Registered Charity No. 1145128 Company Limited by Guarantee Registered in London No. 7862112.https://doi.org/10.1080/1350293X.2021.2007970aheadofprintaheadofprin
Posing Unique and Urgent Challenges to Understandings of Quality: Elucidations through a Froebelian lens
This paper reports on findings from a small pilot study undertaken with early years practitioners in Scotland. The Scottish Government is currently implementing its key election promise of almost doubling the entitlement to publicly funded early learning and childcare (ELC) for all three and four-year old and eligible two-year old children. A key message from the Scottish Government during this period has been that quality is at the heart of the expansion initiative (Scottish Government, 2017b). However, quality can be a contested and an ill understood concept (Moss, 2019). This pilot study, therefore, explored the perspectives of practitioners in Scotland regarding what quality in early years provision entails, particularly in this time of change and expansion. The paper will make three key arguments based on the findings from the study. First, that although quality is a much-used term in Scottish ELC settings, understandings of the term can be subjective, yet powerful and can leave practitioners with more questions than answers. Second, we argue that Fröbelian principles could ameliorate some of the issues regarding quality in Scotland, particularly in terms of combatting discrimination. Finally, we argue that those principles must be accompanied by a social justice lens in which prejudice and stereotypes are recognized, named, and unpacked and action for change taken
A Supercooled Spin Liquid State in the Frustrated Pyrochlore Dy2Ti2O7
A "supercooled" liquid develops when a fluid does not crystallize upon
cooling below its ordering temperature. Instead, the microscopic relaxation
times diverge so rapidly that, upon further cooling, equilibration eventually
becomes impossible and glass formation occurs. Classic supercooled liquids
exhibit specific identifiers including microscopic relaxation times diverging
on a Vogel-Tammann-Fulcher (VTF) trajectory, a Havriliak-Negami (HN) form for
the dielectric function, and a general Kohlrausch-Williams-Watts (KWW) form for
time-domain relaxation. Recently, the pyrochlore Dy2Ti2O7 has become of
interest because its frustrated magnetic interactions may, in theory, lead to
highly exotic magnetic fluids. However, its true magnetic state at low
temperatures has proven very difficult to identify unambiguously. Here we
introduce high-precision, boundary-free magnetization transport techniques
based upon toroidal geometries and gain a fundamentally new understanding of
the time- and frequency-dependent magnetization dynamics of Dy2Ti2O7. We
demonstrate a virtually universal HN form for the magnetic susceptibility, a
general KWW form for the real-time magnetic relaxation, and a divergence of the
microscopic magnetic relaxation rates with precisely the VTF trajectory. Low
temperature Dy2Ti2O7 therefore exhibits the characteristics of a supercooled
magnetic liquid; the consequent implication is that this translationally
invariant lattice of strongly correlated spins is evolving towards an
unprecedented magnetic glass state, perhaps due to many-body localization of
spin.Comment: Version 2 updates: added legend for data in Figures 4A and 4B;
corrected equation reference in caption for Figure 4
Magnetic Monopole Noise
Magnetic monopoles are hypothetical elementary particles exhibiting quantized
magnetic charge and quantized magnetic flux . A classic proposal for detecting such magnetic charges is to measure the
quantized jump in magnetic flux threading the loop of a superconducting
quantum interference device (SQUID) when a monopole passes through it.
Naturally, with the theoretical discovery that a plasma of emergent magnetic
charges should exist in several lanthanide-pyrochlore magnetic insulators,
including DyTiO, this SQUID technique was proposed for their direct
detection. Experimentally, this has proven extremely challenging because of the
high number density, and the generation-recombination (GR) fluctuations, of the
monopole plasma. Recently, however, theoretical advances have allowed the
spectral density of magnetic-flux noise due to GR
fluctuations of magnetic charge pairs to be determined. These
theories present a sequence of strikingly clear predictions for the
magnetic-flux noise signature of emergent magnetic monopoles. Here we report
development of a high-sensitivity, SQUID based flux-noise spectrometer, and
consequent measurements of the frequency and temperature dependence of
for DyTiO samples. Virtually all the elements
of predicted for a magnetic monopole plasma, including the
existence of intense magnetization noise and its characteristic frequency and
temperature dependence, are detected directly. Moreover, comparisons of
simulated and measured correlation functions of the magnetic-flux
noise imply that the motion of magnetic charges is strongly
correlated because traversal of the same trajectory by two magnetic charges of
same sign is forbidden
The mental health and well-being profile of young adults using social media
The relationship between mental health and social media has received significant research and policy attention. However, there is little population-representative data about who social media users are which limits understanding of confounding factors between mental health and social media. Here we profile users of Facebook, Twitter, Instagram, Snapchat and YouTube from the Avon Longitudinal Study of Parents and Children population cohort (N = 4083). We provide estimates of demographics and mental health and well-being outcomes by platform. We find that users of different platforms and frequencies are not homogeneous. User groups differ primarily by sex and YouTube users are the most likely to have poorer mental health outcomes. Instagram and Snapchat users tend to have higher well-being than the other social media sites considered. Relationships between use-frequency and well-being differ depending on the specific well-being construct measured. The reproducibility of future research may be improved by stratifying by sex and being specific about the well-being constructs used
New Study Underway to Estimate the Impact of Lesser Scaup on Arkansas’ Baitfish Industry
The baitfish industry is an important economic enterprise for many aquaculture producers in Arkansas. The industry generates approximately $30 million annually in farm-gate sales of these small fish that include fathead minnows, goldfish and golden shiners. Diving ducks known as scaup, or “Bluebills,” spend late fall through early spring in Arkansas and Mississippi on deep water wetlands, rivers, and aquaculture ponds. The notion that scaup are consuming an abundance of baitfish in Arkansas ponds has concerned commercial growers for several years
3D seismic imaging of buried Younger Dryas mass movement flows: Lake Windermere, UK
Windermere is a glacially overdeepened lake located in the southeastern Lake District, UK. Using the threedimensional(3D) Chirp subbottom profiler, we image mass movement deposits related to the Younger Dryas(YD) within a decimetre-resolution 3D seismic volume, documenting their internal structure and interactionwith preexisting deposits in unprecedented detail. Three distinct flow events are identified and mappedthroughout the 3D survey area. Package structures and seismic attributes classify them as: a small (totalvolume of c. 1500 m3) debris flow containing deformed translated blocks; a large (inferred total volume ofc. 500,000 m3), homogeneous fine-grained mass flow deposit; and a debris flow (inferred total volume ofc. 60,000 m3) containing small (c. 8.0×2.0 m) deformed translated blocks. Geomorphological mapping oftheir distribution and interaction with preexisting sediments permit the reconstruction of a depositionalhistory for the stratigraphic units identified in the seismic volume.<br/
New Study Underway to Estimate the Impact of Lesser Scaup on Arkansas’ Baitfish Industry
The baitfish industry is an important economic enterprise for many aquaculture producers in Arkansas. The industry generates approximately $30 million annually in farm-gate sales of these small fish that include fathead minnows, goldfish and golden shiners. Diving ducks known as scaup, or “Bluebills,” spend late fall through early spring in Arkansas and Mississippi on deep water wetlands, rivers, and aquaculture ponds. The notion that scaup are consuming an abundance of baitfish in Arkansas ponds has concerned commercial growers for several years
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