2,780 research outputs found
Coupled Two-Way Clustering Analysis of Gene Microarray Data
We present a novel coupled two-way clustering approach to gene microarray
data analysis. The main idea is to identify subsets of the genes and samples,
such that when one of these is used to cluster the other, stable and
significant partitions emerge. The search for such subsets is a computationally
complex task: we present an algorithm, based on iterative clustering, which
performs such a search. This analysis is especially suitable for gene
microarray data, where the contributions of a variety of biological mechanisms
to the gene expression levels are entangled in a large body of experimental
data. The method was applied to two gene microarray data sets, on colon cancer
and leukemia. By identifying relevant subsets of the data and focusing on them
we were able to discover partitions and correlations that were masked and
hidden when the full dataset was used in the analysis. Some of these partitions
have clear biological interpretation; others can serve to identify possible
directions for future research
Super-paramagnetic clustering of yeast gene expression profiles
High-density DNA arrays, used to monitor gene expression at a genomic scale,
have produced vast amounts of information which require the development of
efficient computational methods to analyze them. The important first step is to
extract the fundamental patterns of gene expression inherent in the data. This
paper describes the application of a novel clustering algorithm,
Super-Paramagnetic Clustering (SPC) to analysis of gene expression profiles
that were generated recently during a study of the yeast cell cycle. SPC was
used to organize genes into biologically relevant clusters that are suggestive
for their co-regulation. Some of the advantages of SPC are its robustness
against noise and initialization, a clear signature of cluster formation and
splitting, and an unsupervised self-organized determination of the number of
clusters at each resolution. Our analysis revealed interesting correlated
behavior of several groups of genes which has not been previously identified
The Role of Inert Objects in Quantum Mechanical Phase
Quantum mechanical foundations of the polarized neutron phase shift
experiment are discussed. The fact that the neutron retains its ground state
throughout the experiment is shown to be crucial for the phase shift obtained.Comment: 7 pages, no figures, Late
Double-valuedness of the electron wave function and rotational zero-point motion of electrons in rings
I propose that the phase of an electron's wave function changes by when
the electron goes around a loop maintaining phase coherence. Equivalently, that
the minimum orbital angular momentum of an electron in a ring is
rather than zero as generally assumed, hence that the electron in a ring has
azimuthal zero point motion. This proposal provides a physical explanation for
the origin of electronic `quantum pressure', it implies that a spin current
exists in the ground state of aromatic ring molecules, and it suggests an
explanation for the ubiquitousness of persistent currents observed in
mesoscopic rings
An unusually large aggregation of the western conifer seed bug, Leptoglossus occidentalis (Hemiptera: Coreidae), in a man-made structure
An overwintering aggregation of more than 2000 Leptoglossus occidentalis is reported in a manufacturing plant in the southem interior of British Columbia. Such aggregations may be mediated by pheromones. Range extension may have occurred through inadvertent transport of aggregations of overwintering adults
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