Photometric redshifts with Quasi Newton Algorithm (MLPQNA). Results in the PHAT1 contest

Context. Since the advent of modern multiband digital sky surveys, photometric redshifts (photo-z's) have become relevant if not crucial to many fields of observational cosmology, from the characterization of cosmic structures, to weak and strong lensing. Aims. We describe an application to an astrophysical context, namely the evaluation of photometric redshifts, of MLPQNA, a machine learning method based on Quasi Newton Algorithm. Methods. Theoretical methods for photo-z's evaluation are based on the interpolation of a priori knowledge (spectroscopic redshifts or SED templates) and represent an ideal comparison ground for neural networks based methods. The MultiLayer Perceptron with Quasi Newton learning rule (MLPQNA) described here is a computing effective implementation of Neural Networks for the first time exploited to solve regression problems in the astrophysical context and is offered to the community through the DAMEWARE (DAta Mining & ExplorationWeb Application REsource) infrastructure. Results. The PHAT contest (Hildebrandt et al. 2010) provides a standard dataset to test old and new methods for photometric redshift evaluation and with a set of statistical indicators which allow a straightforward comparison among different methods. The MLPQNA model has been applied on the whole PHAT1 dataset of 1984 objects after an optimization of the model performed by using as training set the 515 available spectroscopic redshifts. When applied to the PHAT1 dataset, MLPQNA obtains the best bias accuracy (0.0006) and very competitive accuracies in terms of scatter (0.056) and outlier percentage (16.3%), scoring as the second most effective empirical method among those which have so far participated to the contest. MLPQNA shows better generalization capabilities than most other empirical methods especially in presence of underpopulated regions of the Knowledge Base.Comment: Accepted for publication in Astronomy & Astrophysics; 9 pages, 2 figure

The possibilities of using plasmid ORF clone library for ybeY gene compensation studies in Escherichia coli

The YbeY, encoded by the highly conserved ybeY gene, is a multi-functional protein in Escherichia coli. The processing of the 3′ terminus of 16S rRNA is its most important function, which has a direct effect on the biogenesis of ribosomes. The deletion of ybeY leads to phenotypic and translational defects. YbeY has an extensive network of interactions with other proteins, many of which are still not fully understood. ORF library can be used as a powerful biological tool to detect interactions between proteins. Two different selection strategies were applied using two pooled Gateway® entry clone libraries. Fully pooled library containing all genes represented in the library, and partially pooled library with the lack of some library genes, were electroporated into ybeY null mutants. According to the specificity of each pooled library, the growth selections and PCR methods for genes detecting were different. Results have shown that cultures growth improves during selection. Several genes, whose amount prevails over others in the last selection cycles, were sequenced

Alternative models within the framework of the World Economic Forum’s Travel & Tourism Competitiveness Index – Suggestions for theory development

Destination competitiveness is a relatively young research area. Much research has been done on a conceptual level. Only recently, some authors have developed measures of this highly complex construct. The measure where the most data are available is the Travel & Tourism Competitiveness Index (TTCI), developed by the World Economic Forum. This paper aims at testing this measure’s explanatory power and proposing alternative models within the framework of the (TTCI). Results show that the explanatory power for a dynamic performance criterion is limited and that models that are less pre-structured fit better, explain more and reveal reasons for heterogeneity

PAX8 in ovarian carcinoma: identification of new downstream networks and target genes

PAX8 is a transcription factor involved in the tissue-specific expression of several genes during development, tissue homeostasis and cancer. Recently, PAX8 has been reported to be an important marker for the diagnosis of ovarian carcinoma with a pivotal function in the tumorigenic phenotype of ovarian cancer cells. PAX8 is normally expressed in Fallopian tube secretory cells but not in ovarian surface epithelial cells; however, its expression is detected in the majority of high-grade serous ovarian carcinoma (HGSC) supporting the tubal origin of this cancer. To determine whether PAX8 contributes to ovarian cancer development, we initially conducted a transcriptome analyses to determine the distinctive molecular profiles of the Fallopian tube epithelial secretory cell line (FT194) and the ovarian cancer cell line (SKOV3), before and after PAX8 silencing. The bioinformatics analysis revealed several GO categories enriched in both PAX8-silenced FT-194 and SKOV3 cells. Among those categories, the results showed that both “cell migration” and the “positive regulation of cell migration” bioprocess displayed transcriptional change of 5% in SKOV3 cells and the adhesion category shows change of about 16% in SKOV3 and 14% in FT-194 cells. With respect to specific pathways, the highest differential changes upon PAX8 silencing were found in angiogenesis, Wnt, cadherin and integrin signalling pathways, in both cell types. Since migration and adhesion are important biological processes in both physiological and pathological conditions, migration and adhesion assays were performed using a primary human fallopian tube secretory cells (Primary hFTSECs) and a panel of ovarian cancer cell lines (SKOV3, KURAMOCHI, OVSAHO and PEA1). Interestingly, our results show that inhibition of PAX8 expression in Primary hFTSEC and in epithelial ovarian cancer cell lines significantly reduces the ability of the cells to migrate and adhere on Fibronectin and/or Collagen I substrates. Integrins are reported to be the major regulators of cellular attachment with the extracellular matrix and are required for cellular migration. In our transcriptome analysis, Integrin β3 was significantly downregulated after PAX8 silencing in SKOV3 cells. Therefore, we performed qRT-PCR on Primary hFTSEC and our panel of ovarian cancer cell lines and the results show a strong reduction of Integrin β3 expression in all ovarian cancer cell lines after PAX8 silencing, respect to the control cells. In parallel, we also show that loss of PAX8 does not affect the expression of Integrin αv, the ligand of Integrin β3 involved in ovarian cancer tumorigenesis. The Immunofluorescences assays of the functional heterodimer αvβ3 was tested in Primary hFTSEC and KURAMOCHI cell lines and in PAX8 silenced cells the signal was decreased. In conclusion, we believe that it is of great relevance to further study and decipher the link between PAX8 and Integrin β3 because it could help uncover the role of PAX8 in HGSC development

Computational methods for t-spread monomial ideals

Let $K$ be a field and $S=K[x_1,\ldots,x_n]$ a standard polynomial ring over $K$. In this paper, some new optimized algorithms to compute the smallest $t$-spread lexicographic set and the smallest $t$-spread strongly stable set containing a given set of $t$-spread monomials of $S$ are presented. Some technical tools allowing to compute the cardinality of $t$-spread strongly stable sets avoiding their construction are given. Then, a \emph{Macaulay2} package, \texttt{TSpreadIdeals}, providing methods to easily manage $t$-spread monomials and $t$-spread ideals is implemented. Some functions to ease the calculation of well known results about algebraic invariants for $t$-spread ideals are also provided

The relationship between the intelligence of pupils of different nationalities and the accomplishment of these same individuals of different levels of mental ability

Not Available.Sister Mary Amata HoldenNot ListedNot ListedMaster of ScienceDepartment Not ListedCunningham Memorial library, Terre Haute, Indiana State University.isua-thesis-1942-holden.pdfMastersTitle from document title page. Document formatted into pages: contains 122p. : ill. Includes appendix and bibliography