The robust selection of predictive genes via a simple classifier

Identifying genes that direct the mechanism of a disease from expression data is extremely useful in understanding how that mechanism works. This in turn may lead to better diagnoses and potentially can lead to a cure for that disease. This task becomes extremely challenging when the data are characterised by only a small number of samples and a high number of dimensions, as it is often the case with gene expression data. Motivated by this challenge, we present a general framework that focuses on simplicity and data perturbation. These are the keys for the robust identification of the most predictive features in such data. Within this framework, we propose a simple selective na¨ıve Bayes classifier discovered using a global search technique, and combine it with data perturbation to increase its robustness to small sample sizes. An extensive validation of the method was carried out using two applied datasets from the field of microarrays and a simulated dataset, all confounded by small sample sizes and high dimensionality. The method has been shown capable of identifying genes previously confirmed or associated with prostate cancer and viral infections

Effect of signal duration on detection for gated and for continuous noise

Effect of signal duration on detection for gated and continuous nois

From Golden Spirals to Constant Slope Surfaces

In this paper, we find all constant slope surfaces in the Euclidean 3-space, namely those surfaces for which the position vector of a point of the surface makes constant angle with the normal at the surface in that point. These surfaces could be thought as the bi-dimensional analogue of the generalized helices. Some pictures are drawn by using the parametric equations we found.Comment: 11 pages, 8 figure

Consensus clustering and functional interpretation of gene-expression data

Microarray analysis using clustering algorithms can suffer from lack of inter-method consistency in assigning related gene-expression profiles to clusters. Obtaining a consensus set of clusters from a number of clustering methods should improve confidence in gene-expression analysis. Here we introduce consensus clustering, which provides such an advantage. When coupled with a statistically based gene functional analysis, our method allowed the identification of novel genes regulated by NFκB and the unfolded protein response in certain B-cell lymphomas

The supercluster--void network III. The correlation function as a geometrical statistic

We investigate properties of the correlation function of clusters of galaxies using geometrical models. On small scales the correlation function depends on the shape and the size of superclusters. On large scales it describes the geometry of the distribution of superclusters. If superclusters are distributed randomly then the correlation function on large scales is featureless. If superclusters and voids have a tendency to form a regular lattice then the correlation function on large scales has quasi-regularly spaced maxima and minima of decaying amplitude; i.e., it is oscillating. The period of oscillations is equal to the step size of the grid of the lattice. We calculate the power spectrum for our models and compare the geometrical information of the correlation function with other statistics. We find that geometric properties (the regularity of the distribution of clusters on large scales) are better quantified by the correlation function. We also analyse errors in the correlation function and the power spectrum by generating random realizations of models and finding the scatter of these realizations.Comment: MNRAS LaTex style, 12 pages, 7 PostScript figures embedded, accepted by MNRA

Progression and assessment in foreign languages at Key Stage 2

The teaching of primary languages has been increasing steadily, in response to the future entitlement for all Key Stage 2 (KS2) pupils aged 7-11 to learn a foreign language by 2010. However, there remain concerns about progression both within KS2 and through to secondary school and about how learners' progress is assessed. This paper presents findings on the issues of progression and assessment taken from case studies which formed part of a project funded by the then Department for Education and Skills (DfES), now the Department for Children, Schools and Families (DCSF). This project set out to evaluate 19 local authority (LA) Pathfinders in England that were piloting the introduction of foreign language learning at KS2 between 2003 and 2005. Findings revealed that there was inconsistency between schools, even within each LA Pathfinder, in the use of schemes of work and that assessment was generally underdeveloped in the majority of the Pathfinders. In order to set these findings in context, this paper examines the issues of progression and assessment in foreign language learning in England. Finally, it investigates the challenges English primary schools face in terms of progression and assessment in the light of the new entitlement and discusses implications for the future. Managing progression, both within KS2 and through to secondary school at KS3 (ages 11-14), is one of the key factors in determining the overall success of starting languages in primary school

The Environment of ``E+A'' Galaxies

The violent star formation history of ``E+A'' galaxies and their detection almost exclusively in distant clusters is frequently used to link them to the ``Butcher-Oemler effect'' and to argue that cluster environment influences galaxy evolution. From 11113 spectra in the Las Campanas Redshift Survey, we have obtained a unique sample of 21 nearby ``E+A" galaxies. Surprisingly, a large fraction (about 75%) of these ``E+A''s lie in the field. Therefore, interactions with the cluster environment, in the form of the ICM or cluster potential, are not essential for ``E+A'' formation. If one mechanism is responsible for ``E+A''s, their existence in the field and the tidal features in at least 5 of the 21 argue that galaxy-galaxy interactions and mergers are that mechanism. The most likely environments for such interactions are poor groups, which have lower velocity dispersions than clusters and higher galaxy densities than the field. In hierarchical models, groups fall into clusters in greater numbers at intermediate redshifts than they do today. Thus, the Butcher-Oemler effect may reflect the typical evolution of galaxies in groups and in the field rather than the influence of clusters on star formation in galaxies. This abstract is abridged.Comment: 39 uuencoded, compressed pages (except Fig 1), complete preprint at ftp://ociw.edu/pub/aiz/eplusa.ps, ApJ, submitte

Refinement of the crystal structure of caesium dichloride

CslC12, trigonal, space group R'3m with a= 5.469 (2) A, ~ = 70.67 (3) °, Z= 1. The atomic positions have been determined by least-squares refinement of counter intensities, the final R being 0.031 for 256 reflexions. The I-CI bond length is 2.548 A

Digital Infrastructure Development within a Nonprofit Polymer Science Library: An Analysis of the Transition to Digital Serials at the Michigan Molecular Institute

The authors analyze the issues that the Michigan Molecular Institute Library (MMI) will face in making the transition to digital serials. Supporting a specialized research institute, the library has a limited number of serial subscriptions (68) from a large number of publishers (42). Furthermore, its specialized nature limits the number of potential consortia partners. Strengths include a user community of skilled researchers in a well-defined research area. In making the transition, MMI will encounter both similar and different issues than those found in larger academic and research libraries. Topics covered include current access, planning, licensing, archival concerns, interlibrary loan, interoperability, and emerging trends. The authors recommend that the MMI librarian periodically evaluate the collection strategy in keeping with changing trends