9,399 research outputs found
Tablet computers in assessing performance in a high stakes exam : opinion matters
The authors would like to thank Dr Craig brown, University of Aberdeen for assistance with data analysis.Peer reviewedPublisher PD
Intensity of Rainfall and Severity of Melioidosis, Australia
In a 12-year prospective study of 318 culture-confirmed cases of melioidosis from the Top End of the Northern Territory of Australia, rainfall data for individual patient locations were correlated with patient risk factors, clinical parameters, and outcomes. Median rainfall in the 14 days before admission was highest for those dying with melioidosis (211 mm), in comparison to 110 mm for those surviving (p = 0.0002). Median 14-day rainfall was also significantly higher for those admitted with pneumonia. On univariate analysis, a prior 14-day rainfall of ≥125 mm was significantly correlated with pneumonia (odds ratio [OR] 1.70 [confidence interval [CI] 1.09 to 2.65]), bacteremia (OR 1.93 [CI 1.24 to 3.02]), septic shock (OR 1.94 [CI 1.14 to 3.29]), and death (OR 2.50 [CI 1.36 to 4.57]). On multivariate analysis, rainfall in the 14 days before admission was an independent risk factor for pneumonia (p = 0.023), bacteremic pneumonia (p = 0.001), septic shock (p = 0.005), and death (p < 0.0001). Heavy monsoonal rains and winds may cause a shift towards inhalation of Burkholderia pseudomallei
Automated reduction of submillimetre single-dish heterodyne data from the James Clerk Maxwell Telescope using ORAC-DR
With the advent of modern multi-detector heterodyne instruments that can
result in observations generating thousands of spectra per minute it is no
longer feasible to reduce these data as individual spectra. We describe the
automated data reduction procedure used to generate baselined data cubes from
heterodyne data obtained at the James Clerk Maxwell Telescope. The system can
automatically detect baseline regions in spectra and automatically determine
regridding parameters, all without input from a user. Additionally it can
detect and remove spectra suffering from transient interference effects or
anomalous baselines. The pipeline is written as a set of recipes using the
ORAC-DR pipeline environment with the algorithmic code using Starlink software
packages and infrastructure. The algorithms presented here can be applied to
other heterodyne array instruments and have been applied to data from
historical JCMT heterodyne instrumentation.Comment: 18 pages, 13 figures, submitted to Monthly Notices of the Royal
Astronomical Societ
On the General Ericksen-Leslie System: Parodi's Relation, Well-posedness and Stability
In this paper we investigate the role of Parodi's relation in the
well-posedness and stability of the general Ericksen-Leslie system modeling
nematic liquid crystal flows. First, we give a formal physical derivation of
the Ericksen-Leslie system through an appropriate energy variational approach
under Parodi's relation, in which we can distinguish the
conservative/dissipative parts of the induced elastic stress. Next, we prove
global well-posedness and long-time behavior of the Ericksen-Leslie system
under the assumption that the viscosity is sufficiently large. Finally,
under Parodi's relation, we show the global well-posedness and Lyapunov
stability for the Ericksen-Leslie system near local energy minimizers. The
connection between Parodi's relation and linear stability of the
Ericksen-Leslie system is also discussed
Seeing statistics at the upgraded 3.8m UK infrared telescope (UKIRT)
From 1991 until 1997, the 3.8m UK Infrared Telescope (UKIRT) underwent a
programme of upgrades aimed at improving its intrinsic optical performance.
This resulted in images with a FWHM of 0."17 at 2.2 um in September 1998. To
understand and maintain the improvements to the delivered image quality since
the completion of the upgrades programme, we have regularly monitored the
overall atmospheric seeing, as measured by radial displacements of subaperture
images (i.e. seeing-generated focus fluctuations), and the delivered image
diameters. The latter have been measured and recorded automatically since the
beginning of 2001 whenever the facility imager UFTI (UKIRT Fast Track Imager)
has been in use.
In this paper we report the results of these measurements. We investigate the
relation between the delivered image diameter and the RMS atmospheric seeing
(as measured by focus fluctuations, mentioned above). We find that the best
seeing occurs in the second half of the night, generally after 2am HST and that
the best seeing occurs in the summer between the months of July and September.
We also find that the relationship between Zrms and delivered image diameter is
uncertain. As a result Zrms frequently predicts a larger FWHM than that
measured in the images.
Finally, we show that there is no correlation between near-infrared seeing
measured at UKIRT and sub-mm seeing measured at the Caltech Submillimetre
Observatory (CSO).Comment: 10 pages to appear in the SPIE proceeding vol. 4484 on Observatory
Operations to Maximize Scientific Retur
Remarks on separating words
The separating words problem asks for the size of the smallest DFA needed to
distinguish between two words of length <= n (by accepting one and rejecting
the other). In this paper we survey what is known and unknown about the
problem, consider some variations, and prove several new results
Enumeration and Decidable Properties of Automatic Sequences
We show that various aspects of k-automatic sequences -- such as having an
unbordered factor of length n -- are both decidable and effectively enumerable.
As a consequence it follows that many related sequences are either k-automatic
or k-regular. These include many sequences previously studied in the
literature, such as the recurrence function, the appearance function, and the
repetitivity index. We also give some new characterizations of the class of
k-regular sequences. Many results extend to other sequences defined in terms of
Pisot numeration systems
An investigation into the efficacy of avatar-based systems for student advice
Student support is an important function in all universities. Most students expect access to support 24/7, but support staff cannot be available at all times of day. This paper addresses this problem, describing the development of an avatar-based system to guide students through the materials provided by a university student employability service. Firstly, students and staff were surveyed to establish the demand for such a system. The system was then constructed. Finally, the system was evaluated by students and staff, which led to a clearer understanding of the optimal role for avatar-based systems and consequent improvements to the system’s functionality
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