Search results for "cluster analysis."
showing 10 items of 805 documents
Altered metabolism of gut microbiota contributes to chronic immune activation in HIV-infected individuals.
2015
Altered interplay between gut mucosa and microbiota during treated HIV infection may possibly contribute to increased bacterial translocation and chronic immune activation, both of which are predictors of morbidity and mortality. Although a dysbiotic gut microbiota has recently been reported in HIV + individuals, the metagenome gene pool associated with HIV infection remains unknown. The aim of this study is to characterize the functional gene content of gut microbiota in HIV + patients and to define the metabolic pathways of this bacterial community, which is potentially associated with immune dysfunction. We determined systemic markers of innate and adaptive immunity in a cohort of HIV-in…
Cluster analysis of clinical data reveals three pediatric eosinophilic gastrointestinal disorder phenotypes
2022
Primary eosinophilic gastrointestinal disorders (EGIDs) are a spectrum of emerging inflammatory diseases, which may involve any part of the gastrointestinal (GI) tract and lead to a pathological eosinophilic mucosal infiltration.1,2 Based on the anatomical site of the eosinophil inflammation, EGIDs are classified into eosinophilic esophagitis (EoE) and nonesophageal EGIDs.This study aimed to characterize EGIDs heterogeneity by performing cluster analysis on a cohort of children and adolescents followed at the Pediatric Center for Eosinophilic Gastrointestinal Disorders (CPED) in Pavia, Italy, using an extensive pediatric primary care database from our University Hospital
Improved Photocatalytic Activity of Polysiloxane TiO2 Composites by Thermally Induced Nanoparticle Bulk Clustering and Dye Adsorption
2021
Fine control of nanoparticle clustering within polymeric matrices can be tuned to enhance the physicochemical properties of the resulting composites, which are governed by the interplay of nanoparticle surface segregation and bulk clustering. To this aim, out-of-equilibrium strategies can be leveraged to program the multiscale organization of such systems. Here, we present experimental results indicating that bulk assembly of highly photoactive clusters of titanium dioxide nanoparticles within an in situ synthesized polysiloxane matrix can be thermally tuned. Remarkably, the controlled nanoparticle clustering results in improved degradation photocatalytic performances of the material under …
A Morphological Clustering Method for daily solar radiation curves
2011
Abstract We present a new method based on Mathematical Morphology techniques for the classification of solar radiation curves that we call MfCM. The main advantage of using MfCM as opposed to daily clearness index distributions is that it allows us to keep the dynamics of the solar radiance curves in the analysis: both cloud transitions and variability in direct radiation are simultaneously taken into account. To illustrate our proposal, we use a set of real radiation data collected in a location sited in southern Spain.
Endometrial receptivity and implantation are not affected by the presence of uterine intramural leiomyomas: a clinical and functional genomics analys…
2008
Uterine leiomyomas are the most frequent benign tumors during reproductive age. Whether intramural leiomyomas cause infertility and should be removed is controversial because no study has addressed the underlying mechanism of infertility.The objective of the study was to test the effect of intramural leiomyomas on endometrial function by comparing gene during the window of implantation and implantation in an oocyte donation program, in which the quality of the embryos replaced is similar and the endocrine environment of the endometrium is standardized by exogenous steroids.Human endometria of women with single intramural leiomyomas (group A,5 cm and group B,or =5 cm) and controls (group C) …
A genomic diagnostic tool for human endometrial receptivity based on the transcriptomic signature
2009
Objective: To create a genomic tool composed of a customized microarray and a bioinformatic predictor for endometrial dating and to detect pathologies of endometrial origin. To define the transcriptomic signature of human endometrial receptivity. Design: Two cohorts of endometrial samples along the menstrual cycle were used: one to select the genes to be included in the customized microarray (endometrial receptivity array [ERA]), and the other to be analyzed by ERA to train the predictor for endometrial dating and to define the transcriptomic signature. A third cohort including pathological endometrial samples was used to train the predictor for pathological classification. Setting: Healthy…
ExtMiner : Combining multiple ranking and clustering algorithms for structured document retrieval
2006
This paper introduces ExtMiner, a platform and potential tool for information management in SMEs (small & medium-size enterprise), or for organizational workgroups. ExtMiner supports interactive and iterative clustering of documents. It provides users with a visual cluster and list views at the same time, supporting iterative search process. ExtMiner may also be applied as a platform for research on retrieval fusion, since it combines search, clustering and visualization algorithms. ExtMiner was evaluated with three document collections. Although the findings were encouraging the user interface and performance with large document repositories need further development. peerReviewed
An approach based on the Adaptive Resonance Theory for analysing the viability of recommender systems in a citizen Web portal
2007
This paper proposes a methodology to optimise the future accuracy of a collaborative recommender application in a citizen Web portal. There are four stages namely, user modelling, benchmarking of clustering algorithms, prediction analysis and recommendation. The first stage is to develop analytical models of common characteristics of Web-user data. These artificial data sets are then used to evaluate the performance of clustering algorithms, in particular benchmarking the ART2 neural network with K-means clustering. Afterwards, it is evaluated the predictive accuracy of the clusters applied to a real-world data set derived from access logs to the citizen Web portal Infoville XXI (http://www…
A Semantic Collaborative Clustering Approach Based on Confusion Matrix
2019
In this paper we discuss about a new images retrieval technique based on clustering. We argue that images don’t have an intrinsic meaning, but they can receive different interpretation. These images can complicate documents retrieval. However, users need a quick and direct access to documents. To answer this requirement, we propose a retrieval approach which use a collaborative clustering technique based on Confusion matrix.
Combining fuzzy C-mean and normalized convolution for cloud detection in IR images
2009
An important task for the cloud monitoring in several frameworks is providing maps of the cloud coverage. In this paper we present a method to detect cloudy pixels for images taken from ground by an infra-red camera. The method is a three-steps algorithm mainly based on a Fuzzy C-Mean clustering, that works on a feature space derived from the original image and the output of the reconstructed image obtained via normalized convolution. Experiments, run on several infra-red images acquired under different conditions, show that the cloud maps returned are satisfactory. © 2009 Springer Berlin Heidelberg.