12,951 research outputs found
An integrated model for computer assisted diagnosis, treatment and design of insoles for the diabetic foot
The incidence of diabetes has increased significantly in recent decades. In Germany, there is an estimate of three million diabetics and this number is growing at a rate of about 2 percent per year. In the U.S.A., the American Diabetes Association estimates that thirteen million people suffer from this condition, representing 5.2 percent of the entire population and every year, some 35 thousand patients have a lower limb amputated. In Latin America, it has been reported that the prevalence of diabetes is of the order of 14 to 20 percent, according to a research conducted by the WHO's Ad Hoc Diabetes Reporting Group. In Colombia, a study by Ashner et al concludes that the prevalence is 7 percent in both sexes
Accurate and automatic NOAA-AVHRR image navigation using a global contour matching approach
The problem of precise and automatic AVHRR image navigation is tractable in theory, but has proved to be somewhat difficult in practice. The authors' work has been motivated by the need for a fully automatic and operational navigation system capable of geo-referencing NOAA-AVHRR images with high accuracy and without operator supervision. The proposed method is based on the simultaneous use of an orbital model and a contour matching approach. This last process, relying on an affine transformation model, is used to correct the errors caused by inaccuracies in orbit modeling, nonzero value for the spacecraft's roll, pitch and yaw, errors due to inaccuracies in the satellite positioning and failures in the satellite internal clock. The automatic global contour matching process is summarized as follows: i) Estimation of the gradient energy map (edges) in the sensed image and detection of the cloudless (reliable) areas in this map. ii) Initialization of the affine model parameters by minimizing the Euclidean distance between the reference and sensed images objects. iii) Simultaneous optimization of all reference image contours on the sensed image by energy minimization in the domain of the global transformation parameters. The process is iterated in a hierarchical way, reducing the parameter searching space at each iteration. The proposed image navigation algorithm has proved to be capable of geo-referencing a satellite image within 1 pixel.Peer ReviewedPostprint (published version
Web-based learning and teaching resources for microscopic detection of human parasites.
DMU e-Parasitology (http://parasitology.dmu.ac.uk) presents novel web-based resources co-developed by EU academics at De Montfort University (DMU) for the teaching and learning of microscopic diagnoses of common and emerging human parasites. The package will be completed early in 2019 and presents a Virtual Laboratory and Microscope, which are equipped with engaging units for learning parasitological staining and fresh preparation techniques for detecting cysts, oocysts, eggs and spores, in conjunction with a library of digitised clinical slides. Units are equipped with short videos of academics performing the different techniques and quizzes and exercises, to provide students with the most practical experience possible
Periodic Chaotic Billiards: Quantum-Classical Correspondence in Energy Space
We investigate the properties of eigenstates and local density of states
(LDOS) for a periodic 2D rippled billiard, focusing on their quantum-classical
correspondence in energy representation. To construct the classical
counterparts of LDOS and the structure of eigenstates (SES), the effects of the
boundary are first incorporated (via a canonical transformation) into an
effective potential, rendering the one-particle motion in the 2D rippled
billiard equivalent to that of two-interacting particles in 1D geometry. We
show that classical counterparts of SES and LDOS in the case of strong chaotic
motion reveal quite a good correspondence with the quantum quantities. We also
show that the main features of the SES and LDOS can be explained in terms of
the underlying classical dynamics, in particular of certain periodic orbits. On
the other hand, statistical properties of eigenstates and LDOS turn out to be
different from those prescribed by random matrix theory. We discuss the quantum
effects responsible for the non-ergodic character of the eigenstates and
individual LDOS that seem to be generic for this type of billiards with a large
number of transverse channels.Comment: 13 pages, 18 figure
Top quark physics in hadron collisions
The top quark is the heaviest elementary particle observed to date. Its large
mass makes the top quark an ideal laboratory to test predictions of
perturbation theory concerning heavy quark production at hadron colliders. The
top quark is also a powerful probe for new phenomena beyond the Standard Model
of particle physics. In addition, the top quark mass is a crucial parameter for
scrutinizing the Standard Model in electroweak precision tests and for
predicting the mass of the yet unobserved Higgs boson. Ten years after the
discovery of the top quark at the Fermilab Tevatron top quark physics has
entered an era where detailed measurements of top quark properties are
undertaken. In this review article an introduction to the phenomenology of top
quark production in hadron collisions is given, the lessons learned in Tevatron
Run I are summarized, and first Run II results are discussed. A brief outlook
to the possibilities of top quark research a the Large Hadron Collider,
currently under construction at CERN, is included.Comment: 84 pages, 32 figures, accepted for publication by Reports on Progress
in Physic
Virtual libraries of tissue and clinical samples: potential role of a 3-D microscope.
Our international innovative teaching group from different European Universities (De Montfort University, DMU, UK; and the Spanish University of Alcalá, University Miguel Hernández and University of San Pablo CEU), in conjunction with practicing biomedical scientists in the National Health Service (UK) and biomedical researchers, are developing two complete e-learning packages for teaching and learning medical parasitology, named DMU e-Parasitology (accessible at: http://parasitology.dmu.ac.uk), and biology and chemistry, named DMU e-Biology (accessible at: http://parasitology.dmu.ac.uk/ebiology/index.htm), respectively. Both packages will include a virtual microscope with a complete library of digitised tissue images, clinical slides and cell culture slides/mini-videos for enhancing the teaching and learning of a myriad of techniques applicable to health science undergraduate and postgraduate students. Thus, these packages include detecting human parasites, by becoming familiar with their infective structures and/or organs (e.g. eggs, cysts) and/or explore pathogenic tissues stained with traditional (e.g. haematoxylin & eosin) or more modern (e.g. immunohistochemistry) techniques. The Virtual Microscope (VM) module in the DMU e-Parasitology package is almost completed (accessible at: http://parasitology.dmu.ac.uk/learn/microscope.htm) and contains a section for the three major groups of human-pathogenic parasites (Peña-Fernández et al., 2018) [1]. Digitised slides are provided with the functionality of a microscope by using the gadget Zoomify®, and we consider that they can enhance learning, as previous studies reported in the literature have reported similar sensitivity and specificity rates for identification of parasites for both digitised and real slides. The DMU e-Biology’s VM, currently in development, will provide healthy and pathological tissue samples from a range of mammalian tissues and organs.
This communication will provide a description of both virtual libraries and the process of developing them. In conjunction, we will use a three-dimensional (3D) super-resolution microscopy, 3D Cell Explorer (Nanolive, Lausanne, Switzerland), to incorporate potential 3D microscopic photographs/short videos of cells to provide students with information about the spatial arrangement and morphologies of cells that are essential for life
The Ratio of W + N jets To Z/gamma + N jets As a Precision Test of the Standard Model
We suggest replacing measurements of the individual cross-sections for the
production of W + N jets and Z/gamma + N jets in searches for new high-energy
phenomena at hadron colliders by the precision measurement of the ratios (W+0
jet)/(Z+0 jet), (W+1 jet)/(Z+1 jet), (W+2 jets)/(Z+2 jets),... (W+N jets)/(Z+N
jets), with N as large as 6 (the number of jets in ttbarH). These ratios can
also be formed for the case where one or more of the jets is tagged as a b or c
quark. Existing measurements of the individual cross sections for Wenu + N jets
at the Tevatron have systematic uncertainties that grow rapidly with N, being
dominated by uncertainties in the identification of jets and the jet energy
scale. These systematics, and also those associated with the luminosity, parton
distribution functions (PDF's), detector acceptance and efficiencies, and
systematics of jet finding and b-tagging, are expected to substantially cancel
in calculating the ratio of W to Z production in each N-jet channel, allowing a
greater sensitivity to new contributions in these channels in Run II at the
Tevatron and at the LHC.Comment: 10 pages, 8 figures, added reference
Rank one discrete valuations of power series fields
In this paper we study the rank one discrete valuations of the field
whose center in k\lcor\X\rcor is the maximal ideal. In
sections 2 to 6 we give a construction of a system of parametric equations
describing such valuations. This amounts to finding a parameter and a field of
coefficients. We devote section 2 to finding an element of value 1, that is, a
parameter. The field of coefficients is the residue field of the valuation, and
it is given in section 5.
The constructions given in these sections are not effective in the general
case, because we need either to use the Zorn's lemma or to know explicitly a
section of the natural homomorphism R_v\to\d between the ring and
the residue field of the valuation .
However, as a consequence of this construction, in section 7, we prove that
k((\X)) can be embedded into a field L((\Y)), where is an algebraic
extension of and the {\em ``extended valuation'' is as close as possible to
the usual order function}
Infrared Study of Fullerene Planetary Nebulae
We present a study of 16 PNe where fullerenes have been detected in their
Spitzer spectra. This large sample of objects offers an unique opportunity to
test conditions of fullerene formation and survival under different metallicity
environments as we are analyzing five sources in our own Galaxy, four in the
LMC, and seven in the SMC. Among the 16 PNe under study, we present the first
detection of C60 (possibly also C70) fullerenes in the PN M 1-60 as well as of
the unusual 6.6, 9.8, and 20 um features (possible planar C24) in the PN K
3-54. Although selection effects in the original samples of PNe observed with
Spitzer may play a potentially significant role in the statistics, we find that
the detection rate of fullerenes in C-rich PNe increases with decreasing
metallicity (5% in the Galaxy, 20% in the LMC, and 44% in the SMC). CLOUDY
photoionization modeling matches the observed IR fluxes with central stars that
display a rather narrow range in effective temperature (30,000-45,000 K),
suggesting a common evolutionary status of the objects and similar fullerene
formation conditions. The observed C60 intensity ratios in the Galactic sources
confirm our previous finding in the MCs that the fullerene emission is not
excited by the UV radiation from the central star. CLOUDY models also show that
line- and wind-blanketed model atmospheres can explain many of the observed
[NeIII]/[NeII] ratios by photoionization suggesting that possibly the UV
radiation from the central star, and not shocks, are triggering the
decomposition of the circumstellar dust grains. With the data at hand, we
suggest that the most likely explanation for the formation of fullerenes and
graphene precursors in PNe is that these molecular species are built from the
photo-chemical processing of a carbonaceous compound with a mixture of aromatic
and aliphatic structures similar to that of HAC dust.Comment: Accepted for publication in ApJ (43 pages, 11 figures, and 4 tables).
Small changes to fit the proof-corrected article to be published in Ap
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