119 research outputs found
Exploring Quantum Synchronization with a Composite Two-Qubit Oscillator
Synchronization has recently been explored deep in the quantum regime with
elementary few-level quantum oscillators such as qudits and weakly pumped
quantum Van der Pol oscillators. To engineer more complex quantum synchronizing
systems, it is practically relevant to study composite oscillators built up
from basic quantum units that are commonly available and offer high
controllability. Here, we consider a minimal model for a composite oscillator
consisting of two interacting qubits coupled to separate baths, and show that
this system exhibits a wide variety of synchronizing behaviors. We study the
phase response of the constituent qubits as well as the system as a whole, when
one of the qubits is weakly driven. We consider the thermal baths to have
positive as well as effective negative temperatures, and discover effects that
occur only when the temperatures of the baths for the two qubits are of
opposite signs. We propose and analyze a circuit quantum electrodynamics
implementation of this model, which exploits recent advances in dissipation
engineering to realize effective negative temperature baths. Our work
demonstrates the potential for assembling complex quantum synchronizing systems
from basic building units, which is of pragmatic importance for advancing the
field of quantum synchronization.Comment: 18 pages, 15 figures; includes appendices; improved presentation and
some new result
COVID-KOP: integrating emerging COVID-19 data with the ROBOKOP database
SUMMARY: In response to the COVID-19 pandemic, we established COVID-KOP, a new knowledgebase integrating the existing Reasoning Over Biomedical Objects linked in Knowledge Oriented Pathways (ROBOKOP) biomedical knowledge graph with information from recent biomedical literature on COVID-19 annotated in the CORD-19 collection. COVID-KOP can be used effectively to generate new hypotheses concerning repurposing of known drugs and clinical drug candidates against COVID-19 by establishing respective confirmatory pathways of drug action. AVAILABILITY AND IMPLEMENTATION: COVID-KOP is freely accessible at https://covidkop.renci.org/. For code and instructions for the original ROBOKOP, see: https://github.com/NCATS-Gamma/robokop
Phylotastic! Making tree-of-life knowledge accessible, reusable and convenient
Abstract
Background
Scientists rarely reuse expert knowledge of phylogeny, in spite of years of effort to assemble a great “Tree of Life” (ToL). A notable exception involves the use of Phylomatic, which provides tools to generate custom phylogenies from a large, pre-computed, expert phylogeny of plant taxa. This suggests great potential for a more generalized system that, starting with a query consisting of a list of any known species, would rectify non-standard names, identify expert phylogenies containing the implicated taxa, prune away unneeded parts, and supply branch lengths and annotations, resulting in a custom phylogeny suited to the user’s needs. Such a system could become a sustainable community resource if implemented as a distributed system of loosely coupled parts that interact through clearly defined interfaces.
Results
With the aim of building such a “phylotastic” system, the NESCent Hackathons, Interoperability, Phylogenies (HIP) working group recruited 2 dozen scientist-programmers to a weeklong programming hackathon in June 2012. During the hackathon (and a three-month follow-up period), 5 teams produced designs, implementations, documentation, presentations, and tests including: (1) a generalized scheme for integrating components; (2) proof-of-concept pruners and controllers; (3) a meta-API for taxonomic name resolution services; (4) a system for storing, finding, and retrieving phylogenies using semantic web technologies for data exchange, storage, and querying; (5) an innovative new service, DateLife.org, which synthesizes pre-computed, time-calibrated phylogenies to assign ages to nodes; and (6) demonstration projects. These outcomes are accessible via a public code repository (GitHub.com), a website (
http://www.phylotastic.org
), and a server image.
Conclusions
Approximately 9 person-months of effort (centered on a software development hackathon) resulted in the design and implementation of proof-of-concept software for 4 core phylotastic components, 3 controllers, and 3 end-user demonstration tools. While these products have substantial limitations, they suggest considerable potential for a distributed system that makes phylogenetic knowledge readily accessible in computable form. Widespread use of phylotastic systems will create an electronic marketplace for sharing phylogenetic knowledge that will spur innovation in other areas of the ToL enterprise, such as annotation of sources and methods and third-party methods of quality assessment.http://deepblue.lib.umich.edu/bitstream/2027.42/112888/1/12859_2013_Article_5897.pd
Developing a vocabulary and ontology for modeling insect natural history data: example data, use cases, and competency questions
Insects are possibly the most taxonomically and ecologically diverse class of multicellular organisms on Earth. Consequently, they provide nearly unlimited opportunities to develop and test ecological and evolutionary hypotheses. Currently, however, large-scale studies of insect ecology, behavior, and trait evolution are impeded by the difficulty in obtaining and analyzing data derived from natural history observations of insects. These data are typically highly heterogeneous and widely scattered among many sources, which makes developing robust information systems to aggregate and disseminate them a significant challenge. As a step towards this goal, we report initial results of a new effort to develop a standardized vocabulary and ontology for insect natural history data. In particular, we describe a new database of representative insect natural history data derived from multiple sources (but focused on data from specimens in biological collections), an analysis of the abstract conceptual areas required for a comprehensive ontology of insect natural history data, and a database of use cases and competency questions to guide the development of data systems for insect natural history data. We also discuss data modeling and technology-related challenges that must be overcome to implement robust integration of insect natural history data
Phylotastic! Making tree-of-life knowledge accessible, reusable and convenient
Abstract Background Scientists rarely reuse expert knowledge of phylogeny, in spite of years of effort to assemble a great “Tree of Life” (ToL). A notable exception involves the use of Phylomatic, which provides tools to generate custom phylogenies from a large, pre-computed, expert phylogeny of plant taxa. This suggests great potential for a more generalized system that, starting with a query consisting of a list of any known species, would rectify non-standard names, identify expert phylogenies containing the implicated taxa, prune away unneeded parts, and supply branch lengths and annotations, resulting in a custom phylogeny suited to the user’s needs. Such a system could become a sustainable community resource if implemented as a distributed system of loosely coupled parts that interact through clearly defined interfaces. Results With the aim of building such a “phylotastic” system, the NESCent Hackathons, Interoperability, Phylogenies (HIP) working group recruited 2 dozen scientist-programmers to a weeklong programming hackathon in June 2012. During the hackathon (and a three-month follow-up period), 5 teams produced designs, implementations, documentation, presentations, and tests including: (1) a generalized scheme for integrating components; (2) proof-of-concept pruners and controllers; (3) a meta-API for taxonomic name resolution services; (4) a system for storing, finding, and retrieving phylogenies using semantic web technologies for data exchange, storage, and querying; (5) an innovative new service, DateLife.org, which synthesizes pre-computed, time-calibrated phylogenies to assign ages to nodes; and (6) demonstration projects. These outcomes are accessible via a public code repository (GitHub.com), a website (http://www.phylotastic.org), and a server image. Conclusions Approximately 9 person-months of effort (centered on a software development hackathon) resulted in the design and implementation of proof-of-concept software for 4 core phylotastic components, 3 controllers, and 3 end-user demonstration tools. While these products have substantial limitations, they suggest considerable potential for a distributed system that makes phylogenetic knowledge readily accessible in computable form. Widespread use of phylotastic systems will create an electronic marketplace for sharing phylogenetic knowledge that will spur innovation in other areas of the ToL enterprise, such as annotation of sources and methods and third-party methods of quality assessment
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Announcing the Biomedical Data Translator: Initial Public Release.
The growing availability of biomedical data offers vast potential to improve human health, but the complexity and lack of integration of these datasets often limit their utility. To address this, the Biomedical Data Translator Consortium has developed an open-source knowledge graph-based system-Translator-designed to integrate, harmonize, and make inferences over diverse biomedical data sources. We announce here Translators initial public release and provide an overview of its architecture, standards, user interface, and core features. Translator employs a scalable, federated, knowledge graph framework for the integration of clinical, genomic, pharmacological, and other biomedical knowledge sources, enabling query retrieval, inference, and hypothesis generation. Translators user interface is designed to support the exploration of knowledge relationships and the generation of insights, without requiring deep technical expertise and gradually revealing more detailed evidence, provenance, and confidence information, as needed by a given user. To demonstrate Translators application and impact, we highlight features of the user interface in the context of three real-world use cases: suggesting potential therapeutics for patients with rare disease; explaining the mechanism of action of a pipeline drug; and screening and validating drug candidates in a model organism. We discuss strengths and limitations of reasoning within a largely federated system and the need for rich concept modeling and deep provenance tracking. Finally, we outline future directions for enhancing Translators functionality and expanding its data sources. Translator represents a significant step forward in making complex biomedical knowledge more accessible and actionable, aiming to accelerate translational research and improve patient care
Recommended from our members
Phylotastic! Making tree-of-life knowledge accessible, reusable and convenient
Background: Scientists rarely reuse expert knowledge of phylogeny, in spite of years of effort to assemble a great
“Tree of Life” (ToL). A notable exception involves the use of Phylomatic, which provides tools to generate custom
phylogenies from a large, pre-computed, expert phylogeny of plant taxa. This suggests great potential for a more
generalized system that, starting with a query consisting of a list of any known species, would rectify non-standard
names, identify expert phylogenies containing the implicated taxa, prune away unneeded parts, and supply branch
lengths and annotations, resulting in a custom phylogeny suited to the user’s needs. Such a system could become
a sustainable community resource if implemented as a distributed system of loosely coupled parts that interact
through clearly defined interfaces.
Results: With the aim of building such a “phylotastic” system, the NESCent Hackathons, Interoperability, Phylogenies
(HIP) working group recruited 2 dozen scientist-programmers to a weeklong programming hackathon in June 2012.
During the hackathon (and a three-month follow-up period), 5 teams produced designs, implementations,
documentation, presentations, and tests including: (1) a generalized scheme for integrating components; (2) proofof-
concept pruners and controllers; (3) a meta-API for taxonomic name resolution services; (4) a system for storing,
finding, and retrieving phylogenies using semantic web technologies for data exchange, storage, and querying; (5) an
innovative new service, DateLife.org, which synthesizes pre-computed, time-calibrated phylogenies to assign ages to
nodes; and (6) demonstration projects. These outcomes are accessible via a public code repository (GitHub.com), a
website (www.phylotastic.org), and a server image.
Conclusions: Approximately 9 person-months of effort (centered on a software development hackathon) resulted in
the design and implementation of proof-of-concept software for 4 core phylotastic components, 3 controllers, and 3
end-user demonstration tools. While these products have substantial limitations, they suggest considerable potential
for a distributed system that makes phylogenetic knowledge readily accessible in computable form. Widespread use of
phylotastic systems will create an electronic marketplace for sharing phylogenetic knowledge that will spur innovation
in other areas of the ToL enterprise, such as annotation of sources and methods and third-party methods of quality
assessment.Keywords: Web services, Taxonomy, Data reuse, Phylogeny, Tree of life, HackathonKeywords: Web services, Taxonomy, Data reuse, Phylogeny, Tree of life, Hackatho
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
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