1,354 research outputs found
Early Localization of Bronchogenic Carcinoma
The performance of a fluorescence imaging device was compared with conventional white-light bronchoscopy in 100 patients with lung cancer, 46 patients with resected stage I non-small cell lung cancer,
10 patients with head and neck cancer, and 67 volunteers who had smoked at least 1 pack of
cigarettes per day for 25 years or more. Using differences in tissue autofluorescence between premalignant,
malignant, and normal tissues, fluorescence bronchoscopy was found to detect significantly
more areas with moderate/severe dysplasia or carcinoma in situ than conventional white-light
bronchoscopy with a similar specificity. Multiple foci of dysplasia or cancer were found in 13–24%
of these individuals. Fluorescence bronchoscopy may be an important adjunct to conventional bronchoscopic
examination to improve our ability to detect and localize premalignant and early lung cancer
lesions
Apolarity, Hessian and Macaulay polynomials
A result by Macaulay states that an Artinian graded Gorenstein ring R of
socle dimension one and socle degree b can be realized as the apolar ring of a
homogeneous polynomial f of degree b. If R is the Jacobian ring of a smooth
hypersurface g=0, then b is just equal to the degree of the Hessian polynomial
of g. In this paper we investigate the relationship between f and the Hessian
polynomial of g.Comment: 12 pages. Improved exposition, minor correction
Ultra-light Axions: Degeneracies with Massive Neutrinos and Forecasts for Future Cosmological Observations
A generic prediction of string theory is the existence of many axion fields.
It has recently been argued that many of these fields should be light and, like
the well known QCD axion, lead to observable cosmological consequences. In this
paper we study in detail the effect of the so-called string axiverse on large
scale structure, focusing on the morphology and evolution of density
perturbations, anisotropies in the cosmic microwave background and weak
gravitational lensing of distant galaxies. We quantify specific effects that
will arise from the presence of the axionic fields and highlight possible
degeneracies that may arise in the presence of massive neutrinos. We take
particular care understanding the different physical effects and scales that
come into play. We then forecast how the string axiverse may be constrained and
show that with a combination of different observations, it should be possible
to detect a fraction of ultralight axions to dark matter of a few percent.Comment: 24 pages, 16 figures, this version: corrected typos, some comments
added, matches published versio
The ABCD of usability testing
We introduce a methodology for tracking and auditing feedback, errors and suggestions for software packages. This short paper describes how we innovate on the evaluation mechanism, introducing an (Antecedent, Barrier, Consequence and Development) ABCD form, embedded within an eParticipation platform to enable end users to easily report on any usability issues. This methodology will be utilised to improve the STEP cloud eParticipation platform (part of the current STEP Horizon2020 project http://step4youth.eu. The platform is currently being piloted in real life contexts, with the participation of public authorities that are integrating the eParticipation platform into their regular decision-making practices. The project is involving young people, through engagement and motivation strategies and giving them a voice in Environmental decision making at the local level. The pilot evaluation aims to demonstrate how open engagement needs to be embedded within public sector processes and the usability methodology reported here will help to identify the key barriers for wide scale deployment of the platform
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"It’s so fluid, it's developing all the time": pre-service teachers' perceptions and understanding of cyberbullying in the school environment
To gain an insight into how those entering the teaching profession regard cyberbullying, two focus groups were conducted with nine pre-service teachers (PSTs). Thematic analytical approach revealed three themes: (a) evolving nature of bullying (b) involvement in cyberbullying and (c) management of cyberbullying. PSTs discussed how cyberbullying was evolving and becoming socially acceptable in the modern world. Participants addressed features of victimisation and perpetration associated with cyberbullying. PSTs reflected on the responsibility to address cyberbullying, discussing effective strategies to manage the issue. Participants considered the extent to which their Initial Teacher Training course prepared prospective teachers to manage cyberbullying
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Perceptions and responses towards cyberbullying: a systematic review of teachers in the education system
The rise and availability of digital technologies for young people have presented additional challenges for teachers in the school environment. One such challenge is cyberbullying, an escalating concern, associated with wide-reaching negative consequences for those involved and the surrounding community. The present systematic review explored teachers’ perceptions and responses towards cyberbullying in the education system. Once the search strategy was applied across the six databases, 20 studies fulfilled the inclusion criteria for the current review. The studies were reviewed and examined for common themes. Five themes were identified: (a) Cyberbullying characteristics and student involvement, (b) Cyberbullying training and guidance for teachers, (c) School commitment and strategies to manage cyberbullying, (d) The impact and extent of cyberbullying prevalence and consequences, and (e) Teachers’ confidence and concern towards cyberbullying. The themes are discussed in a narrative synthesis with reference to implications for teachers and for the continued development and review of anti-cyberbullying initiatives
Regina Lectures on Fat Points
These notes are a record of lectures given in the Workshop on Connections
Between Algebra and Geometry at the University of Regina, May 29--June 1, 2012.
The lectures were meant as an introduction to current research problems related
to fat points for an audience that was not expected to have much background in
commutative algebra or algebraic geometry (although sections 8 and 9 of these
notes demand somewhat more background than earlier sections).Comment: 32 pages, 3 figure
Characterization of carbon nanotube–thermotropic nematic liquid crystal composites
Dispersions of carbon nanotubes (CNTs) in liquid crystals (LCs) have attracted attention due to their unique properties and possible applications in photonics and electronics. However, these are hard to stabilize, and the loading level in the equilibrium state in LC hosts is small. A practical way to monitor the quality and CNT incorporation in such equilibrium dispersions is required. Here, we compare different methods for characterising equilibrium CNT–LC composite materials
Quasar accretion disk sizes from continuum reverberation mapping in the DES standard-star fields
Measurements of the physical properties of accretion disks in active galactic
nuclei are important for better understanding the growth and evolution of
supermassive black holes. We present the accretion disk sizes of 22 quasars
from continuum reverberation mapping with data from the Dark Energy Survey
(DES) standard star fields and the supernova C fields. We construct continuum
lightcurves with the \textit{griz} photometry that span five seasons of DES
observations. These data sample the time variability of the quasars with a
cadence as short as one day, which corresponds to a rest frame cadence that is
a factor of a few higher than most previous work. We derive time lags between
bands with both JAVELIN and the interpolated cross-correlation function method,
and fit for accretion disk sizes using the JAVELIN Thin Disk model. These new
measurements include disks around black holes with masses as small as
, which have equivalent sizes at 2500\AA \, as small as
light days in the rest frame. We find that most objects have
accretion disk sizes consistent with the prediction of the standard thin disk
model when we take disk variability into account. We have also simulated the
expected yield of accretion disk measurements under various observational
scenarios for the Large Synoptic Survey Telescope Deep Drilling Fields. We find
that the number of disk measurements would increase significantly if the
default cadence is changed from three days to two days or one day.Comment: 33 pages, 24 figure
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