1,547 research outputs found
Efficient Discovery of Ontology Functional Dependencies
Poor data quality has become a pervasive issue due to the increasing
complexity and size of modern datasets. Constraint based data cleaning
techniques rely on integrity constraints as a benchmark to identify and correct
errors. Data values that do not satisfy the given set of constraints are
flagged as dirty, and data updates are made to re-align the data and the
constraints. However, many errors often require user input to resolve due to
domain expertise defining specific terminology and relationships. For example,
in pharmaceuticals, 'Advil' \emph{is-a} brand name for 'ibuprofen' that can be
captured in a pharmaceutical ontology. While functional dependencies (FDs) have
traditionally been used in existing data cleaning solutions to model syntactic
equivalence, they are not able to model broader relationships (e.g., is-a)
defined by an ontology. In this paper, we take a first step towards extending
the set of data quality constraints used in data cleaning by defining and
discovering \emph{Ontology Functional Dependencies} (OFDs). We lay out
theoretical and practical foundations for OFDs, including a set of sound and
complete axioms, and a linear inference procedure. We then develop effective
algorithms for discovering OFDs, and a set of optimizations that efficiently
prune the search space. Our experimental evaluation using real data show the
scalability and accuracy of our algorithms.Comment: 12 page
Accretion through the inner hole of transitional disks: What happens to the dust?
We study the effect of radiation pressure on the dust in the inner rim of
transitional disks with large inner holes. In particular, we evaluate whether
radiation pressure can be responsible for keeping the inner holes dust-free,
while allowing gas accretion to proceed. This has been proposed in a paper by
Chiang and Murray-Clay (2007, Nature Physics 3, p. 604) who explain the
formation of these holes as an inside-out evacuation due to X- ray-triggered
accretion of the innermost layer of the disk rim outside of the hole. We show
that radiation pressure is clearly incapable of stopping dust from flowing into
the hole because of dust pile-up and optical depth effects, and also because of
viscous mixing. Other mechanisms need to be found to explain the persistence of
the opacity hole in the presence of accretion, and we speculate on possible
solutions.Comment: 6 pages, 3 figures, Accepted for publication by Astronomy and
Astrophysic
A 10-bit SAR ADC with an Ultra-Low Power Supply
This paper presents a successive approximation analog-to-digital converter (SAR ADC) design, which operates with a 0.2 V power supply. The design utilizes a dynamic bulk biasing scheme to dynamically adjust the relative NMOS and PMOS strengths, which are very sensitive to temperature, process, and mismatch variations at low supply voltages. The design achieves a very low power consumption due to the 0.2 V supply. Several circuits in the design are optimized for full functionality at 0.2 V. Extracted simulations show a total power consumption of 9 nW with a peak SNDR of 61.3 dB and a Walden Figure of Merit of 1.91 fJ/conversion-step
Attitudes towards Interprofessional education in the medical curriculum: a systematic review of the literature
Pre-licensure medical students’ knowledge and views on interprofessional learning: A qualitative concept analysis based on real-world data
Background: The several definitions of Interprofessional Education (IPE) allow for different interpretations and interchangeable terms. This study aims to determine the characteristics and attributes of the definition of IPE.
Materials and methods: In November 2019, 31 medical students (64.5% female) from a single institution took part in nine semi-structured interviews. We created a deductive three-level code system followed by an inductive code system based on several known IPE definitions. We extracted the main entities of the concept of IPE according to both code systems to create a framework. We used MaxQDA software for qualitative analysis. Verification of codes and categories was attained through sequential peer-debrief.
Results: Participants correctly named the WHO’s definition of IPE, and outlined its four main dimensions according to the Interprofessional Education Collaborative report. We found new IPE attributes and demonstrated the weight of communication and role recognition. Two-thirds of medical students mentioned IPE activities that we classified as a contrary model (without collaboration or patient-centeredness) and a minimum weight was given to the importance of patient-centeredness.
Conclusion: Medical students’ understanding of the concept of IPE is coherent. We deepened the understanding of previously identified definitions of IPE, and we identified new attributes of the concept. Finally, we added “well-being” as a component of interprofessionality
Effects of X-ray irradiation and disk flaring on the [NeII] 12.8 micron emission from young stellar objects
The [Ne II] fine-structure emission line at 12.8 micron has been detected in
several young stellar objects (YSO) spectra. This line is thought to be
produced by X-ray irradiation of the warm protoplanetary disk atmospheres,
however the observational correlation between [Ne II] luminosities and measured
X-ray luminosities shows a large scatter. Such spread limits the utility of
this line as a probe of the gaseous phase of disks, as several authors have
suggested pollution by outflows as a probable cause of the observed scatter. In
this work we explore the possibility that the large variations in the observed
[Ne II] luminosity may be caused instead by different star-disk parameters. In
particular we study the effects that the hardness of the irradiating source and
the structure (flaring) of the disk have on the luminosity and spectral profile
of the [Ne II] 12.8 micron line. We find that varying these parameter can
indeed cause up to an order of magnitude variation in the emission luminosities
which may explain the scatter observed, although our models predict somewhat
smaller luminosities than those recently reported by other authors who observed
the line with the Spitzer Space Telescope. Our models also show that the
hardness of the spectrum has only a limited (undetectable) effect on the line
profiles, while changes in the flaring power of the disk significantly affect
the size of the [Ne II] emission region and, as a consequence, its line
profile. In particular we suggest that broad line profiles centred on the
stellar radial velocity may be indicative of flat disks seen at large
inclination angles.Comment: 9 pages, 8 figures. accepted for publication in MNRA
Attitudes of medical students towards interprofessional education:A mixed-methods study
BackgroundInterprofessional Education (IPE) aims to improve students' attitudes towards collaboration, teamwork, and leads to improved patient care upon graduation. However, the best time to introduce IPE into the undergraduate curriculum is still under debate.MethodsWe used a mixed-methods design based on a sequential explanatory model. Medical students from all six years at the University of Bern, Switzerland (n = 683) completed an online survey about attitudes towards interprofessional learning using a scale validated for German speakers (G-IPAS). Thirty-one medical students participated in nine semi-structured interviews focusing on their experience in interprofessional learning and on the possible impact it might have on their professional development.ResultsWomen showed better attitudes in the G-IPAS across all years (p = 0,007). Pre-clinical students showed more positive attitudes towards IPE [Year 1 to Year 3 (p = 0.011)]. Students correctly defined IPE and its core dimensions. They appealed for more organized IPE interventions throughout the curriculum. Students also acknowledged the relevance of IPE for their future professional performance.ConclusionsThese findings support an early introduction of IPE into the medical curriculum. Although students realise that interprofessional learning is fundamental to high-quality patient care, there are still obstacles and stereotypes to overcome.Trial registrationISRCTN 41715934
Isometric Force Production Symmetry and Jumping Performance in Collegiate Athletes
Objectives: The purpose of this study was to identify the relationship between isometric force production symmetry and jumping performance in weighted and un-weighted static and countermovement jumps (SJ and CMJ). Design: Bivariate correlation between isometric force production symmetry and vertical jump performance variables. Methods: Collegiate athletes were evaluated for this study (n=36). Subjects performed SJ, CMJ, and isometric mid-thigh pulls (IMTP). Jumps were analyzed for jump height (JH) and peak power (PP). IMTP was analyzed for peak force (PF) for left and right sides, and values were calculated to produce a peak force symmetry index (PF-SI) score. Correlational statistics were performed examining the relationship between PF-SI and jump variables. Results: Moderate statistically significant negative correlations were observed between PF-SI and all jump variables, indicating that as asymmetry increases jump performance decreases. SJ correlations weakened in weighted conditions (JH r=-0.52 @ 0 kg/r=-0.39 @ 20 kg, PP r=-0.43 @ 0 kg/r=-0.34 @ 20 kg), but CMJ produced similar correlations for both conditions (JH r=-0.47 @ 0 kg/r=-0.49 @ 20 kg, PP r=-0.28 @ 0 kg/r=-0.34 @ 20 kg). Unlike the SJ, which only contains the propulsive or concentric portion of the jump, the CMJ also contains the eccentric portion and performance contributions of the stretch-shortening cycle (SSC). The addition of the SSC may play a role in the maintaining the magnitude of asymmetry in the CMJ weighted condition. Conclusions: The results indicate that force production asymmetry may be detrimental to bilateral vertical jumping performance. The findings should be considered for further investigation on sport-specific tasks
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