466 research outputs found
Subgroup Discovery: Real-World Applications
Subgroup discovery is a data mining technique which extracts interesting rules with respect
to a target variable. An important characteristic of this task is the combination of predictive
and descriptive induction. In this paper, an overview about subgroup discovery is performed.
In addition, di erent real-world applications solved through evolutionary algorithms where the
suitability and potential of this type of algorithms for the development of subgroup discovery
algorithms are presented
Analysing the Moodle e-learning platform through subgroup discovery algorithms based on evolutionary fuzzy systems
Nowadays, there is a increasing in the use of learning management systems
from the universities. This type of systems are also known under other
di erent terms as course management systems or learning content management
systems. Speci cally, these systems are e-learning platforms o ering
di erent facilities for information sharing and communication between the
participants in the e-learning process.
This contribution presents an experimental study with several subgroup
discovery algorithms based on evolutionary fuzzy systems using data from a
web-based education system. The main objective of this contribution is to
extract unusual subgroups to describe possible relationships between the use
of the e-learning platform and marks obtained by the students. The results
obtained by the best performing algorithm, NMEEF-SD, are also presented.
The most representative results obtained by this algorithm are summarised in
order to obtain knowledge that can allow teachers to take actions to improve student performance
Subgroup Discovery trhough Evolutionary Fuzzy Systems applied to Bioinformatic problems
Subgroup discovery is a descriptive data mining technique using supervised learning. This
paper presents a summary about the main properties and elements about subgroup discovery task.
In addition, we will focus on the suitability and potential of the search performed by evolutionary
algorithms in order to apply in the development of subgroup discovery algorithms, and in the use
of fuzzy logic which is a soft computing technique very close to the human reasoning. The
hybridisation of both techniques are well known as evolutionary fuzzy system.
The most relevant applications of evolutionary fuzzy systems for subgroup discovery in the
bioinformatics domains are outlined in this work. Specifically, these algorithms are applied to a
problem based on the Influenza A virus and the accute sore throat problem
Supervised Descriptive Rule Discovery: A Survey of the State-of-the-Art
The supervised descriptive rule discovery concept groups a set of data mining techniques whose objective is to
describe data with respect to a property of interest. Among the techniques within this concept are the subgroup
discovery, emerging patterns and contrast sets.
This contribution presents the supervised descriptive rule discovery concept within the data mining literature.
Specifically, it is important to remark the main di erence with respect to other existing techniques within classification
or description. In addition, a a survey of the state-of-the-art about the different techniques within supervised
descriptive rule discovery throughout the literature can be observed. The paper allows to the experts to analyse the
compatibilities between terms and heuristics of the different data mining tasks within this concept
Examining the role of wine brand love on brand loyalty: a multi-country comparison
This study develops and tests a model through a multi-country study that considers consumer wine knowledge and wine experience, wine brand trust and wine brand satisfaction as antecedents of wine brand love, and wine brand loyalty as a consequence of wine brand love. Data were collected in five wine-producing countries (Australia, Chile, France, Mexico and Portugal) with a final sample of 3462 completed surveys. Hypotheses were tested with structural equation modeling and the findings confirm the importance of brand love as both a mediator and direct influence on brand loyalty for wine consumers. Furthermore, brand satisfaction was positively and significantly related to brand love. In addition, wine experience, rather than wine knowledge, positively influenced brand trust and satisfaction. Finally, results also identify differences between countries thereby providing insights into how companies should focus their marketing strategies internationally.info:eu-repo/semantics/acceptedVersio
Neurologic phenotype of Schimke immuno-osseous dysplasia and neurodevelopmental expression of SMARCAL1
Schimke immuno-osseous dysplasia (OMIM 242900) is an uncommon autosomal-recessive multisystem disease caused by mutations in SMARCAL1 (swi/snf-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a-like 1), a gene encoding a putative chromatin remodeling protein. Neurologic manifestations identified to date relate to enhanced atherosclerosis and cerebrovascular disease. Based on a clinical survey, we determined that half of Schimke immuno-osseous dysplasia patients have a small head circumference, and 15% have social, language, motor, or cognitive abnormalities. Postmortem examination of 2 Schimke immuno-osseous dysplasia patients showed low brain weights and subtle brain histologic abnormalities suggestive of perturbed neuron-glial migration such as heterotopia, irregular cortical thickness, incomplete gyral formation, and poor definition of cortical layers. We found that SMARCAL1 is highly expressed in the developing and adult mouse and human brain, including neural precursors and neuronal lineage cells. These observations suggest that SMARCAL1 deficiency may influence brain development and function in addition to its previously recognized effect on cerebral circulation
Comparative electron temperature measurements of Thomson scattering and electron cyclotron emission diagnostics in TCABR plasmas
We present the first simultaneous measurements of the Thomson scattering and electron cyclotron emission radiometer diagnostics performed at TCABR tokamak with Alfven wave heating. The Thomson scattering diagnostic is an upgraded version of the one previously installed at the ISTTOK tokamak, while the electron cyclotron emission radiometer employs a heterodyne sweeping radiometer. For purely Ohmic discharges, the electron temperature measurements from both diagnostics are in good agreement. Additional Alfven wave heating does not affect the capability of the Thomson scattering diagnostic to measure the instantaneous electron temperature, whereas measurements from the electron cyclotron emission radiometer become underestimates of the actual temperature values. (C) 2010 American Institute of Physics. [doi:10.1063/1.3494379]811
Novel bioactive hydrophobic gentamicin carriers for the treatment of intracellular bacterial infections.
Gentamicin (GEN) is an aminoglycoside antibiotic with a potent antibacterial activity against a wide variety of bacteria. However, its poor cellular penetration limits its use in the treatment of infections caused by intracellular pathogens. One potential strategy to overcome this problem is the use of particulate carriers that can target the intracellular sites of infection. In this study GEN was ion paired with the anionic AOT surfactant to obtain a hydrophobic complex (GEN-AOT) that was formulated as a particulated material either by the Precipitation with a Compressed Antisolvent (PCA) method, or by encapsulation into poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles (NPs). The micronization of GEN-AOT by PCA yielded a particulated material with a higher surface area than the non-precipitated complex, while PLGA NPs within a size range of 250-330 nm and a sustained release of the drug over 70 days were obtained by preparing the NPs using the emulsion solvent evaporation method. For the first time, GEN encapsulation efficiency values around 100% were achieved for the different NP formulations with no signs of interaction between the drug and the polymer. Finally, in vitro studies against the intracellular bacteria Brucella melitensis, used as a model of intracellular pathogen, demonstrated that the bactericidal activity of GEN was unmodified after ion-pairing, precipitation or encapsulation into NPs. These results, encourage their use for treatment for infections caused by GEN sensitive intracellular bacteria
The eclipse of the V773 Tau B circumbinary disk
A deep (~70%) and extended (~150 days) eclipse was seen towards the young
multiple stellar system V773 Tau in 2010. We interpret it as due to the passage
of a circumbinary disk around the B components moving in front of the A
components. Our aim is to characterise the orientation and structure of the
disk, to refine the orbits of the subcomponents, and to predict when the next
eclipse will occur.
We combine the photometry from several ground based surveys, construct a
model for the light curve of the eclipse, and use high angular resolution
imaging to refine the orbits of the three components of the system, A, B and C.
Frequency analysis of the light curves, including from the TESS satellite,
enables characterisation of the rotational periods of the Aa and Ab stars.
A toy model of the circumbinary disk shows that it extends out to
approximately 5 au around the B binary and has an inclination of 73 degrees
with respect to the orbital plane of AB, where the lower bound of the radius of
the disk is constrained by the geometry of the AB orbit and the upper bound is
set by the stability of the disk. We identify several frequencies in the
photometric data that we attribute to rotational modulation of the Aa and Ab
stellar companions. We produce the first determination of the orbit of the more
distant C component around the AB system and limit its inclination to 93
degrees.
The high inclination and large diameter of the disk, together with the match
from theory suggest that B is an almost equal mass, moderately eccentric
binary. We identify the rotational periods of the Aa and Ab stars, identify a
third frequency in the light curve that we attribute to the orbital period of
the stars in the B binary. We predict that the next eclipse will be around
2037, during which both detailed photometric and spectroscopic monitoring will
characterise the disk in greater detail.Comment: 13 pages, 15 figures, 5 tables, A&A in press. All data and reduction
scripts available at https://github.com/mkenworthy/V773TauBdis
Aryl hydrocarbon receptor is required for optimal B-cell proliferation
The aryl hydrocarbon receptor (AhR), a transcription factor known for mediating xenobiotic toxicity, is expressed in B cells, which are known targets for environmental pollutants. However, it is unclear what the physiological functions of AhR in B cells are. We show here that expression of Ahr in B cells is up‐regulated upon B‐cell receptor (BCR) engagement and IL‐4 treatment. Addition of a natural ligand of AhR, FICZ, induces AhR translocation to the nucleus and transcription of the AhR target gene Cyp1a1, showing that the AhR pathway is functional in B cells. AhR‐deficient (Ahr (−/−)) B cells proliferate less than AhR‐sufficient (Ahr (+/+)) cells following in vitro BCR stimulation and in vivo adoptive transfer models confirmed that Ahr (−/−) B cells are outcompeted by Ahr (+/+) cells. Transcriptome comparison of AhR‐deficient and AhR‐sufficient B cells identified cyclin O (Ccno), a direct target of AhR, as a top candidate affected by AhR deficiency
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