7,367 research outputs found
The context-dependence of mutations: a linkage of formalisms
Defining the extent of epistasis - the non-independence of the effects of
mutations - is essential for understanding the relationship of genotype,
phenotype, and fitness in biological systems. The applications cover many areas
of biological research, including biochemistry, genomics, protein and systems
engineering, medicine, and evolutionary biology. However, the quantitative
definitions of epistasis vary among fields, and its analysis beyond just
pairwise effects remains obscure in general. Here, we show that different
definitions of epistasis are versions of a single mathematical formalism - the
weighted Walsh-Hadamard transform. We discuss that one of the definitions, the
backgound-averaged epistasis, is the most informative when the goal is to
uncover the general epistatic structure of a biological system, a description
that can be rather different from the local epistatic structure of specific
model systems. Key issues are the choice of effective ensembles for averaging
and to practically contend with the vast combinatorial complexity of mutations.
In this regard, we discuss possible approaches for optimally learning the
epistatic structure of biological systems.Comment: 6 pages, 3 figures, supplementary informatio
Machine Learning for Fluid Mechanics
The field of fluid mechanics is rapidly advancing, driven by unprecedented
volumes of data from field measurements, experiments and large-scale
simulations at multiple spatiotemporal scales. Machine learning offers a wealth
of techniques to extract information from data that could be translated into
knowledge about the underlying fluid mechanics. Moreover, machine learning
algorithms can augment domain knowledge and automate tasks related to flow
control and optimization. This article presents an overview of past history,
current developments, and emerging opportunities of machine learning for fluid
mechanics. It outlines fundamental machine learning methodologies and discusses
their uses for understanding, modeling, optimizing, and controlling fluid
flows. The strengths and limitations of these methods are addressed from the
perspective of scientific inquiry that considers data as an inherent part of
modeling, experimentation, and simulation. Machine learning provides a powerful
information processing framework that can enrich, and possibly even transform,
current lines of fluid mechanics research and industrial applications.Comment: To appear in the Annual Reviews of Fluid Mechanics, 202
The impact of culture on mobile phone purchasing: A comparison between Thai and British consumers
The idea of ICT Convergence is used by many practitioners and observers - such as economists,
politicians, journalists, and academics - as an important descriptor for technological change.
However, a review of previous work in this field suggests that, despite more than 30 years of research
on ICT Convergence, the theoretical basis of the concept of convergence is still under-researched. In
particular in the IS literature, the concept has been either relegated to the sidelines or taken for
granted without further reflection. Therefore, a systematic analysis of the idea of ICT Convergence
from an IS perspective is needed.
This paper aims to explore how the discourse of convergence is being shaped in the IS literature. In
order to address this question, 317 articles published in ten leading IS journals from 1998 to 2008
have been examined. This study has been built around a Grounded Theory approach informed by
Niklas Luhmann\u27s Theory of Distinction.
The findings show that convergence cannot be viewed as a single concept. Five archetypes of
convergence communication are identified, and a conceptualization of ICT Convergence as a
double process between alignment and interoperability is suggested. The main limitation of this paper
is the focus on leading IS journals
A metaproteomic approach to study human-microbial ecosystems at the mucosal luminal interface
Aberrant interactions between the host and the intestinal bacteria are thought to contribute to the pathogenesis of many digestive diseases. However, studying the complex ecosystem at the human mucosal-luminal interface (MLI) is challenging and requires an integrative systems biology approach. Therefore, we developed a novel method integrating lavage sampling of the human mucosal surface, high-throughput proteomics, and a unique suite of bioinformatic and statistical analyses. Shotgun proteomic analysis of secreted proteins recovered from the MLI confirmed the presence of both human and bacterial components. To profile the MLI metaproteome, we collected 205 mucosal lavage samples from 38 healthy subjects, and subjected them to high-throughput proteomics. The spectral data were subjected to a rigorous data processing pipeline to optimize suitability for quantitation and analysis, and then were evaluated using a set of biostatistical tools. Compared to the mucosal transcriptome, the MLI metaproteome was enriched for extracellular proteins involved in response to stimulus and immune system processes. Analysis of the metaproteome revealed significant individual-related as well as anatomic region-related (biogeographic) features. Quantitative shotgun proteomics established the identity and confirmed the biogeographic association of 49 proteins (including 3 functional protein networks) demarcating the proximal and distal colon. This robust and integrated proteomic approach is thus effective for identifying functional features of the human mucosal ecosystem, and a fresh understanding of the basic biology and disease processes at the MLI. © 2011 Li et al
Evolutionary Algorithms for Reinforcement Learning
There are two distinct approaches to solving reinforcement learning problems,
namely, searching in value function space and searching in policy space.
Temporal difference methods and evolutionary algorithms are well-known examples
of these approaches. Kaelbling, Littman and Moore recently provided an
informative survey of temporal difference methods. This article focuses on the
application of evolutionary algorithms to the reinforcement learning problem,
emphasizing alternative policy representations, credit assignment methods, and
problem-specific genetic operators. Strengths and weaknesses of the
evolutionary approach to reinforcement learning are presented, along with a
survey of representative applications
An Enhanced Sampling-Based Viewpoints Cosine Visual Model for an Efficient Big Data Clustering
Bunching is registering the item's similitude includes that can be utilized to segment the information. Object similarity (or dissimilarity) features are taken into account when locating relevant data object clusters. Removing the quantity of bunch data for any information is known as the grouping inclination. Top enormous information bunching calculations, similar to single pass k-implies (spkm), k-implies ++, smaller than usual group k-implies (mbkm), are created in the groups with k worth. By and by, the k worth is alloted by one or the other client or with any outside impedance. Along these lines, it is feasible to get this worth immovable once in a while. In the wake of concentrating on related work, it is researched that visual appraisal of (bunch) propensity (Tank) and its high level visual models extraordinarily decide the obscure group propensity esteem k. Multi-perspectives based cosine measure Tank (MVCM-Tank) utilized the multi-perspectives to evaluate grouping inclination better. Be that as it may, the MVCM-Tank experiences versatility issues in regards to computational time and memory designation. This paper improves the MVCM-Tank with the inspecting methodology to defeat the versatility issue for large information grouping. Trial investigation is performed utilizing the enormous gaussian engineered datasets and large constant datasets to show the effectiveness of the proposed work
SARS-CoV-2 virus RNA sequence classification and geographical analysis with convolutional neural networks approach
Covid-19 infection, which spread to the whole world in December 2019 and is
still active, caused more than 250 thousand deaths in the world today.
Researches on this subject have been focused on analyzing the genetic structure
of the virus, developing vaccines, the course of the disease, and its source.
In this study, RNA sequences belonging to the SARS-CoV-2 virus are transformed
into gene motifs with two basic image processing algorithms and classified with
the convolutional neural network (CNN) models. The CNN models achieved an
average of 98% Area Under Curve(AUC) value was achieved in RNA sequences
classified as Asia, Europe, America, and Oceania. The resulting artificial
neural network model was used for phylogenetic analysis of the variant of the
virus isolated in Turkey. The classification results reached were compared with
gene alignment values in the GISAID database, where SARS-CoV-2 virus records
are kept all over the world. Our experimental results have revealed that now
the detection of the geographic distribution of the virus with the CNN models
might serve as an efficient method
- …