1,947 research outputs found
Haematalogical investigations in children
The haematology laboratory is able to perform a number of tests to help establish the cause of illness
in children. The full blood count (FBC, also known as a complete blood count, CBC) is one of the most
basic blood tests performed on children attending hospital or a primary care clinic. All doctors should
therefore have an understanding of how the test is performed, possible pitfalls, be able to interpret
results and know when more specialised testing or advice is required. Other haematological
investigations in routine use include coagulation screens, blood film examination, reticulocyte counts
and methods for estimation of iron stores and detection of abnormal haemoglobins. This section will
focus on these basic tests and simple algorithms for the subsequent investigation and differential
diagnosis of the commonest haemato-logical abnormalities encountered in general paediatric practice.
The reader is referred to Chapter 15 for an account of the clinical presentation and management of
primary haematological disorders in children
Diffusion-limited aggregation as branched growth
I present a first-principles theory of diffusion-limited aggregation in two
dimensions. A renormalized mean-field approximation gives the form of the
unstable manifold for branch competition, following the method of Halsey and
Leibig [Phys. Rev. A {\bf 46}, 7793 (1992)]. This leads to a result for the
cluster dimensionality, D \approx 1.66, which is close to numerically obtained
values. In addition, the multifractal exponent \tau(3) = D in this theory, in
agreement with a proposed `electrostatic' scaling law.Comment: 13 pages, one figure not included (available by request, by ordinary
mail), Plain Te
Granular gravitational collapse and chute flow
Inelastic grains in a flow under gravitation tend to collapse into states in
which the relative normal velocities of two neighboring grains is zero. If the
time scale for this gravitational collapse is shorter than inverse strain rates
in the flow, we propose that this collapse will lead to the formation of
``granular eddies", large scale condensed structures of particles moving
coherently with one another. The scale of these eddies is determined by the
gradient of the strain rate. Applying these concepts to chute flow of granular
media, (gravitationally driven flow down inclined planes) we predict the
existence of a bulk flow region whose rheology is determined only by flow
density. This theory yields the experimental ``Pouliquen flow rule",
correlating different chute flows; it also correctly accounts for the different
flow regimes observed.Comment: LaTeX2e with epl class, 7 pages, 2 figures, submitted to Europhysics
Letter
High-Dimensional Diffusive Growth
We consider a model of aggregation, both diffusion-limited and ballistic,
based on the Cayley tree. Growth is from the leaves of the tree towards the
root, leading to non-trivial screening and branch competition effects. The
model exhibits a phase transition between ballistic and diffusion-controlled
growth, with non-trivial corrections to cluster size at the critical point.
Even in the ballistic regime, cluster scaling is controlled by extremal
statistics due to the branching structure of the Cayley tree; it is the
extremal nature of the fluctuations that enables us to solve the model.Comment: 5 pages, 3 figures; reference adde
Branched Growth with Walkers
Diffusion-limited aggregation has a natural generalization to the
"-models", in which random walkers must arrive at a point on the
cluster surface in order for growth to occur. It has recently been proposed
that in spatial dimensionality , there is an upper critical
above which the fractal dimensionality of the clusters is D=1. I compute the
first order correction to for , obtaining . The
methods used can also determine multifractal dimensions to first order in
.Comment: 6 pages, 1 figur
Multifractal Dimensions for Branched Growth
A recently proposed theory for diffusion-limited aggregation (DLA), which
models this system as a random branched growth process, is reviewed. Like DLA,
this process is stochastic, and ensemble averaging is needed in order to define
multifractal dimensions. In an earlier work [T. C. Halsey and M. Leibig, Phys.
Rev. A46, 7793 (1992)], annealed average dimensions were computed for this
model. In this paper, we compute the quenched average dimensions, which are
expected to apply to typical members of the ensemble. We develop a perturbative
expansion for the average of the logarithm of the multifractal partition
function; the leading and sub-leading divergent terms in this expansion are
then resummed to all orders. The result is that in the limit where the number
of particles n -> \infty, the quenched and annealed dimensions are {\it
identical}; however, the attainment of this limit requires enormous values of
n. At smaller, more realistic values of n, the apparent quenched dimensions
differ from the annealed dimensions. We interpret these results to mean that
while multifractality as an ensemble property of random branched growth (and
hence of DLA) is quite robust, it subtly fails for typical members of the
ensemble.Comment: 82 pages, 24 included figures in 16 files, 1 included tabl
WHO LIVES, WHO DIES, WHO TELLS YOUR STORY: A CASE STUDY OF HAMILTON: AN AMERICAN MUSICAL TO UNDERSTAND THE EFFECT OF ENGAGING THE PAST IN THE CULTURE OF TODAY
This thesis is a look into how Alexander Hamilton has been portrayed on stage in the musical Hamilton: An American Musical, written by Lin-Manuel Miranda. The goal of this research is to show that this musical is not history, but rather a commentary on current culture through one of America’s favorite stories (that of the Revolution.) In this show, past figures have been used to discuss the issues of modern America, and that is now being sold as history. This has been discovered through the analysis of primary and secondary sources of the time period, as well as through a listening to and understanding of the show. Through this analysis, it can be seen that anachronism is a real and present danger in the study of history, as modern ideas influence the story being told. While historically based art can be beautiful, it is often shaped into the story writers wish to tell rather than what had occurred
Effect of weak disorder in the Fully Frustrated XY model
The critical behaviour of the Fully Frustrated XY model in presence of weak
positional disorder is studied in a square lattice by Monte Carlo methods. The
critical exponent associated to the divergence of the chiral correlation length
is found to be equal to 1.7 already at very small values of disorder.
Furthermore the helicity modulus jump is found larger than the universal value
expected in the XY model.Comment: 8 pages, 4 figures (revtex
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