Gene expression data typically are large, complex, and highly noisy. Their dimension is high with several thousand genes (i.e., features) but with only a limited number of observations (i.e., samples). Although the classical principal component analysis (PCA) method is widely used as a first standard step in dimension reduction and in supervised and unsupervised classification, it suffers from several shortcomings in the case of data sets involving undersized samples, since the sample covariance matrix degenerates and becomes singular. In this paper we address these limitations within the context of probabilistic PCA (PPCA) by introducing and developing a new and novel approach using maximum entropy covariance matrix and its hybridized smoothed covariance estimators. To reduce the dimensionality of the data and to choose the number of probabilistic PCs (PPCs) to be retained, we further introduce and develop celebrated Akaike's information criterion (AIC), consistent Akaike's information criterion (CAIC), and the information theoretic measure of complexity (ICOMP) criterion of Bozdogan. Six publicly available undersized benchmark data sets were analyzed to show the utility, flexibility, and versatility of our approach with hybridized smoothed covariance matrix estimators, which do not degenerate to perform the PPCA to reduce the dimension and to carry out supervised classification of cancer groups in high dimensions.
This study looked at tertiary (i.e. undergraduate /a four-year degree) students' information and communication technology (ICT) self-efficacy beliefs and their level in use of certain common programmes at a newly established (i.e. 2007) university in Turkey in the spring of 2012. The study examined the tertiary students' (a) demographic background, (b) their ICT self-efficacy beliefs and (c) their ICT-using level in certain common programs. The students at three different departments were given the questionnaires to complete. 363 participants completed them. The study was mostly quantitative and partly qualitative. The quantitative results were analysed with SPSS (i.e. descriptive statistics, ANOVA, Independent Samples Test). The qualitative data were analysed by examining the participants' responses gathered from the open-ended questions and focussing on the shared themes among the responses. The results revealed that the participants were ICT literate and users. They had positive ICT self-efficacy beliefs and their level in certain programs was good. There were also statistical differences between (a) their ICT self-efficacy beliefs and (b) ICT level in certain common programs in terms of different independent variables (i.e. the length of ICT-use, the place of ICT-access, the frequency of ICT-use, the type of the course they were attending, and gender). The findings are consistent with models and theories of technology engagement which recognise facilitating or inhibiting conditions. The implications are (1) to provide (free) full-access to ICT in terms of efficient resources and technology availability, (2) to provide (efficient) ICT courses and (3) to integrate ICT into teaching/learning.
Parasite infections are common during the critical developmental period in children. The occurrences of intestinal parasites are also common in orphanage, nurseries and schools in Turkey. The study was carried out to determine the percentage of microsporidium and intestinal parasites in children from Malatya, Turkey. This study was carried out at the Department of Parasitology of Inonu University, Turgut Ozal Medical Center, during January-December 2006. Totally, 1,181 stool samples were examined using the native-Lugol, sedimentation-techniques, modified trichrome (MTS), acid-fast-trichrome stain and calcofluor staining methods. In addition, perianal region material was taken from the children to examine with cellophane tape method. Power analyses were performed for statistical analyses used. Microsporidia were found in 92 (7.8%) of the samples, and also intestinal parasites were detected in 329 (27.8%). The numbers of infections according to the species were as follows: 69 (5.8%) Entamoeba coli, 7 (0.6%) Blastocystis hominis, 114 (9.7%) Giardia intestinalis, 15 (1.3%) Iodomoeba butchlii, 8 (0.7%) Dientamoeba fragilis, 7 (0.6%) Taenia spp. 70 (5.9%) Enterobius vermicularis, 11 (0.9%) Hymenolepis nana, 25 (2.1%) Trichomonas intestinalis, 1 (0.1%) Ascaris lumbricoides and 2 (0.2%) Chilomastix mesnilii. Also, greater than 90% power values were achieved for statistical analyses. Whereas the detection rates of microsporidium and intestinal parasites were found to be low, it was concluded that in addition to intestinal parasites, microsporidium should be also searched for in children with complaints of intestinal system.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.