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Modelling the preferences of students for alternative assignment designs using the Discrete Choice Experiment methodology
This paper outlines how a discrete choice experiment (DCE) can be used to learn more about how students are willing to trade off various features of assignments such as the nature and timing of feedback and the method used to submit assignments. A DCE identifies plausible levels of the key attributes of a good or service and then presents the respondent with alternative bundles of these attributes and their levels and asks the respondent to choose between particular bundles. We report results from a DCE we conducted with undergraduate business students regarding their preferences for assignment systems. We find that the most important features of assignments are how relevant the assignments are for exam preparation and the nature of the feedback that students receive. We also find that students generally prefer online to paper assignments. We argue that the DCE approach has a lot of potential in education research. Accessed 4,497 times on https://pareonline.net from November 13, 2014 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right
Genetic-Algorithm-based Light Curve Optimization Applied to Observations of the W UMa star BH Cas
I have developed a procedure utilizing a Genetic-Algorithm-based optimization
scheme to fit the observed light curves of an eclipsing binary star with a
model produced by the Wilson-Devinney code. The principal advantages of this
approach are the global search capability and the objectivity of the final
result. Although this method can be more efficient than some other comparably
global search techniques, the computational requirements of the code are still
considerable. I have applied this fitting procedure to my observations of the W
UMa type eclipsing binary BH Cassiopeiae. An analysis of V-band CCD data
obtained in 1994/95 from Steward Observatory and U- and B-band photoelectric
data obtained in 1996 from McDonald Observatory provided three complete light
curves to constrain the fit. In addition, radial velocity curves obtained in
1997 from McDonald Observatory provided a direct measurement of the system mass
ratio to restrict the search. The results of the GA-based fit are in excellent
agreement with the final orbital solution obtained with the standard
differential corrections procedure in the Wilson-Devinney code.Comment: 9 pages, 2 figures, 2 tables, uses emulateapj.st
Implementation of an End-to-End Standards-based Patient Monitoring Solution
A proof-of-concept design of a patient monitoring solution for intensive care unit environments has been presented. It is end-to-end standard-based, using ISO/IEEE 11073 (X73) in the bedside environment and EN13606 to communicate the information to an electronic healthcare record (EHR) server. At the bedside end, the system is a plug-and-play sensor network communicating with a gateway that collects medical information and sends the data to a monitoring server. The monitoring server transforms this information into an EN13606 extract to be stored on the EHR server. The system has been implemented to comply with the last X73 and EN13606 available versions and tested in a laboratory environment to demonstrate the feasibility of an end-to-end standard-based solution
Constraining the properties of delta Scuti stars using spectroscopic eclipsing binary systems
Many stars exhibit stellar pulsations, favoring them for asteroseismic
analyses. Interpreting the oscillations requires some knowledge of the
oscillation mode geometry (spherical degree, radial and azimuthal orders). The
delta Scuti stars (1.5 - 2.5 M_sol) often show just one or few pulsation
frequencies. Although this may promise a successful seismological analysis, we
may not know enough about either the mode or the star to use the oscillation
frequency to improve the determination of the stellar model, or probe the
star's structure. For the observed frequencies to be used successfully as
seismic probes of these objects, we need to concentrate on stars for which we
can reduce the number of free parameters in the problem, such as binary systems
or open clusters. We investigate how much our understanding of a delta Scuti
star is improved when it is in a detached eclipsing binary system instead of
being a single field star. We use singular value decomposition to explore the
precision we expect in stellar parameters (mass, age and chemical composition)
for both cases. We examine how the parameter uncertainties propagate to the
luminosity - effective temperature diagram and determine when the effort of
obtaining a new measurement is justified. We show that for the single star, a
correct identification of the oscillation mode is necessary to produce strong
constraints on the stellar model properties, while for the binary system the
observations without the pulsation mode provide the same or better constraints
on the stellar parameters. In the latter case, ...Comment: emulateapj 16 pages, accepted Ap
Cognitive Performance in Midlife Type 2 Diabetes: Results form the ENBIND Study
Aims: To establish the impact of uncomplicated type 2 diabetes on cognitive and neuropsychological performance in midlife. Methods: We performed a cross-sectional study of middle-aged adults with uncomplicated type 2 diabetes and a cohort of healthy control participants. General cognition was assessed using the Montreal Cognitive Assessment test and neuropsychological assessment was undertaken using a detailed neuropsychological assessment battery. Results: A total of 152 participants (102 with type 2 diabetes and 50 controls) were recruited (mean age 52 ± 8 years, 51% women). Participants with midlife type 2 diabetes were more than twice as likely to make an error on the Montreal Cognitive Assessment test [incidence rate ratio 2.44 (95% CI 1.54 to 3.87); P \u3c 0.001]. Further, type 2 diabetes was also associated with significantly lower memory composite score [β: −0.20 (95% CI −0.39 to −0.01); P = 0.04] and paired associates learning score [β: = −1.97 (95% CI −3.51, −0.43); P = 0.01] on the neuropsychological assessment battery following adjustment for age, sex, BMI, educational attainment and hypercholesterolaemia. Conclusions: Even in midlife, type 2 diabetes was associated with small but statistically significant cognitive decrements. These statistically significant decrements, whilst not clinically significant in terms of objective cognitive impairment, may have important implications in selecting out individuals most at risk of later cognitive decline for potential preventative interventions in midlife
Asteroseismology with the WIRE satellite. I. Combining Ground- and Space-based Photometry of the Delta Scuti Star Epsilon Cephei
We have analysed ground-based multi-colour Stromgren photometry and
single-filter photometry from the star tracker on the WIRE satellite of the
delta scuti star Epsilon Cephei. The ground-based data set consists of 16
nights of data collected over 164 days, while the satellite data are nearly
continuous coverage of the star during 14 days. The spectral window and noise
level of the satellite data are superior to the ground-based data and this data
set is used to locate the frequencies. However, we can use the ground-based
data to improve the accuracy of the frequencies due to the much longer time
baseline. We detect 26 oscillation frequencies in the WIRE data set, but only
some of these can be seen clearly in the ground-based data. We have used the
multi-colour ground-based photometry to determine amplitude and phase
differences in the Stromgren b-y colour and the y filter in an attempt to
identify the radial degree of the oscillation frequencies. We conclude that the
accuracies of the amplitudes and phases are not sufficient to constrain
theoretical models of Epsilon Cephei. We find no evidence for rotational
splitting or the large separation among the frequencies detected in the WIRE
data set. To be able to identify oscillation frequencies in delta scuti stars
with the method we have applied, it is crucial to obtain more complete coverage
from multi-site campaigns with a long time baseline and in multiple filters.
This is important when planning photometric and spectroscopic ground-based
support for future satellite missions like COROT and KEPLER.Comment: 13 pages, 12 figures, 4 tables. Fig. 4 reduced in quality. Accepted
by A&
A Planet Orbiting the Star Rho Coronae Borealis
We report the discovery of near-sinusoidal radial velocity variations of the
G0V star rhoCrB, with period 39.6 days and amplitude 67 m/s. These variations
are consistent with the existence of an orbital companion in a circular orbit.
Adopting a mass of 1.0 M(Sun) for the primary, the companion has minimum mass
about 1.1 Jupiter masses, and orbital radius about 0.23 AU. Such an orbital
radius is too large for tidal circularization of an initially eccentric orbit
during the lifetime of the star, and hence we suggest that the low eccentricity
is primordial, as would be expected for a planet formed in a dissipative
circumstellar disk.Comment: 9 pages, LaTeX, accepted in Astrophys. J. Letter
Contemporary multicenter outcomes of continent cutaneous ileocecocystoplasty in the adult population over a 10-year period: A Neurogenic Bladder Research Group study
AIMS: Evidence is sparse on the long-term outcomes of continent cutaneous ileocecocystoplasty (CCIC). We hypothesized that obesity, laparoscopic/robotic approach, and concomitant surgeries would affect morbidity after CCIC and aimed to evaluate the outcomes of CCIC in adults in a multicenter contemporary study.
METHODS: We retrospectively reviewed the charts of adult patients from sites in the Neurogenic Bladder Research Group undergoing CCIC (2007-2017) who had at least 6 months of follow-up. We evaluated patient demographics, surgical details, 90-day complications, and follow-up surgeries. the Mann-Whitney U test was used to compare continuous variables and χ² and Fisher\u27s Exact tests were used to compare categorical variables.
RESULTS: We included 114 patients with a median age of 41 years. The median postoperative length of stay was 8 days. At 3 months postoperatively, major complications occurred in 18 (15.8%), and 24 patients (21.1%) were readmitted. During a median follow-up of 40 months, 48 patients (42.1%) underwent 80 additional related surgeries. Twenty-three patients (20.2%) underwent at least one channel revision, most often due to obstruction (15, 13.2%) or incontinence (4, 3.5%). Of the channel revisions, 10 (8.8%) were major and 14 (12.3%) were minor. Eleven patients (9.6%) abandoned the catheterizable channel during the follow-up period. Obesity and laparoscopic/robotic surgical approach did not affect outcomes, though concomitant surgery was associated with a higher rate of follow-up surgeries.
CONCLUSIONS: In this contemporary multicenter series evaluating CCIC, we found that the short-term major complication rate was low, but many patients require follow-up surgeries, mostly related to the catheterizable channel
Using a limited mapping strategy to identify major QTLs for resistance to grapevine powdery mildew (Erysiphe necator) and their use in marker-assisted breeding
A limited genetic mapping strategy based on simple sequence repeat (SSR) marker data was used with five grape populations segregating for powdery mildew (Erysiphe necator) resistance in an effort to develop genetic markers from multiple sources and enable the pyramiding of resistance loci. Three populations derived their resistance from Muscadinia rotundifolia ‘Magnolia’. The first population (06708) had 97 progeny and was screened with 137 SSR markers from seven chromosomes (4, 7, 9, 12, 13, 15, and 18) that have been reported to be associated with powdery or downy mildew resistance. A genetic map was constructed using the pseudo-testcross strategy and QTL analysis was carried out. Only markers from chromosome 13 and 18 were mapped in the second (04327) and third (06712) populations, which had 47 and 80 progeny, respectively. Significant QTLs for powdery mildew resistance with overlapping genomic regions were identified for different tissue types (leaf, stem, rachis, and berry) on chromosome 18, which distinguishes the resistance in ‘Magnolia’ from that present in other accessions of M. rotundifolia and controlled by the Run1 gene on chromosome 12. The ‘Magnolia’ resistance locus was termed as Run2.1. Powdery mildew resistance was also mapped in a fourth population (08391), which had 255 progeny and resistance from M. rotundifolia ‘Trayshed’. A locus accounting for 50% of the phenotypic variation mapped to chromosome 18 and was named Run2.2. This locus overlapped the region found in the ‘Magnolia’-based populations, but the allele sizes of the flanking markers were different. ‘Trayshed’ and ‘Magnolia’ shared at least one allele for 68% of the tested markers, but alleles of the other 32% of the markers were not shared indicating that the two M. rotundifolia selections were very different. The last population, 08306 with 42 progeny, derived its resistance from a selection Vitis romanetii C166-043. Genetic mapping discovered a major powdery mildew resistance locus termed Ren4 on chromosome 18, which explained 70% of the phenotypic variation in the same region of chromosome 18 found in the two M. rotundifolia resistant accessions. The mapping results indicate that powdery mildew resistance genes from different backgrounds reside on chromosome 18, and that genetic markers can be used as a powerful tool to pyramid these loci and other powdery mildew resistance loci into a single line
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