1,234 research outputs found
A statistical normalization method and differential expression analysis for RNA-seq data between different species
Background: High-throughput techniques bring novel tools but also statistical
challenges to genomic research. Identifying genes with differential expression
between different species is an effective way to discover evolutionarily
conserved transcriptional responses. To remove systematic variation between
different species for a fair comparison, the normalization procedure serves as
a crucial pre-processing step that adjusts for the varying sample sequencing
depths and other confounding technical effects.
Results: In this paper, we propose a scale based normalization (SCBN) method
by taking into account the available knowledge of conserved orthologous genes
and hypothesis testing framework. Considering the different gene lengths and
unmapped genes between different species, we formulate the problem from the
perspective of hypothesis testing and search for the optimal scaling factor
that minimizes the deviation between the empirical and nominal type I errors.
Conclusions: Simulation studies show that the proposed method performs
significantly better than the existing competitor in a wide range of settings.
An RNA-seq dataset of different species is also analyzed and it coincides with
the conclusion that the proposed method outperforms the existing method. For
practical applications, we have also developed an R package named "SCBN" and
the software is available at
http://www.bioconductor.org/packages/devel/bioc/html/SCBN.html
Design and fabrication of robust broadband extreme ultraviolet multilayers
The random layer thickness variations can induce a great deformation of the
experimental reflection of broadband extreme ultraviolet multilayer. In order
to reduce this influence of random layer thickness fluctuations, the
multiobjective genetic algorithm has been improved and used in the robust
design of multilayer with a broad angular bandpass. The robust multilayer with
a lower sensitivity to random thickness errors have been obtained and the
corresponding multilayer mirrors were fabricated. The experimental results of
robust Mo/Si multilayer with a wide angular band were presented and analyzed,
and the advantage of robust multilayer design was demonstrated
Data-driven Computational Social Science: A Survey
Social science concerns issues on individuals, relationships, and the whole
society. The complexity of research topics in social science makes it the
amalgamation of multiple disciplines, such as economics, political science, and
sociology, etc. For centuries, scientists have conducted many studies to
understand the mechanisms of the society. However, due to the limitations of
traditional research methods, there exist many critical social issues to be
explored. To solve those issues, computational social science emerges due to
the rapid advancements of computation technologies and the profound studies on
social science. With the aids of the advanced research techniques, various
kinds of data from diverse areas can be acquired nowadays, and they can help us
look into social problems with a new eye. As a result, utilizing various data
to reveal issues derived from computational social science area has attracted
more and more attentions. In this paper, to the best of our knowledge, we
present a survey on data-driven computational social science for the first time
which primarily focuses on reviewing application domains involving human
dynamics. The state-of-the-art research on human dynamics is reviewed from
three aspects: individuals, relationships, and collectives. Specifically, the
research methodologies used to address research challenges in aforementioned
application domains are summarized. In addition, some important open challenges
with respect to both emerging research topics and research methods are
discussed.Comment: 28 pages, 8 figure
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