5,017 research outputs found
Formulating MEDLINE queries for article retrieval based on PubMed exemplars
Bibliographic search engines allow endless possibilities for building queries based on specific words or phrases in article titles and abstracts, indexing terms, and other attributes. Unfortunately, deciding which attributes to use in a methodologically sound query is a non-trivial process. In this paper, we describe a system to help with this task, given an example set of PubMed articles to retrieve and a corresponding set of articles to exclude. The system provides the users with unigram and bigram features from the title, abstract, MeSH terms, and MeSH qualifier terms in decreasing order of precision, given a recall threshold. From this information and their knowledge of the domain, users can formulate a query and evaluate its performance. We apply the system to the task of distinguishing original research articles of functional magnetic resonance imaging (fMRI) of sensorimotor function from fMRI studies of higher cognitive functions
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The combining of explicit phonics and the literature basis of whole language
Controlling the layer localization of gapless states in bilayer graphene with a gate voltage
Experiments in gated bilayer graphene with stacking domain walls present
topological gapless states protected by no-valley mixing. Here we research
these states under gate voltages using atomistic models, which allow us to
elucidate their origin. We find that the gate potential controls the layer
localization of the two states, which switches non-trivially between layers
depending on the applied gate voltage magnitude. We also show how these bilayer
gapless states arise from bands of single-layer graphene by analyzing the
formation of carbon bonds between layers. Based on this analysis we provide a
model Hamiltonian with analytical solutions, which explains the layer
localization as a function of the ratio between the applied potential and
interlayer hopping. Our results open a route for the manipulation of gapless
states in electronic devices, analogous to the proposed writing and reading
memories in topological insulators
Chemical Kinship: Interdisciplinary Experiments with Pollution
This is the final version. Available from catalystjournal.org via the DOI in this record. Feminist technoscientific research with chemicals is proliferating. This critical commentary considers how this scholarship extends environmental justice research on pollution. We are concerned with two key questions: How can we do/design ethical research with chemicals? And, what methods allow for researching chemicals without resorting to an imagined space of purity? We consider unfolding projects which reorient relations with chemicals from villainous objects with violent effects, to chemical kin. We imagine chemical kinship as a concept, an analytical tool, and a mode of relating. Emerging through feminist and anticolonial work with chemicals, it involves a tentativeness towards making normative claims about chemicals because, like kin, these materials are never entirely good nor bad, at once they can both be enabling and harmful. This commentary considers what the unfolding research with chemicals generates, and consolidates conceptualisations of chemical kinship; we ultimately articulate an agenda for ethical research with chemicals as an experimental process of invention.Economic and Social Research Counci
Computability of simple games: A characterization and application to the core
The class of algorithmically computable simple games (i) includes the class
of games that have finite carriers and (ii) is included in the class of games
that have finite winning coalitions. This paper characterizes computable games,
strengthens the earlier result that computable games violate anonymity, and
gives examples showing that the above inclusions are strict. It also extends
Nakamura's theorem about the nonemptyness of the core and shows that computable
games have a finite Nakamura number, implying that the number of alternatives
that the players can deal with rationally is restricted.Comment: 35 pages; To appear in Journal of Mathematical Economics; Appendix
added, Propositions, Remarks, etc. are renumbere
Semiconductor-metal nanoparticle molecules: hybrid excitons and non-linear Fano effect
Modern nanotechnology opens the possibility of combining nanocrystals of
various materials with very different characteristics in one superstructure.
The resultant superstructure may provide new physical properties not
encountered in homogeneous systems. Here we study theoretically the optical
properties of hybrid molecules composed of semiconductor and metal
nanoparticles. Excitons and plasmons in such a hybrid molecule become strongly
coupled and demonstrate novel properties. At low incident light intensity, the
exciton peak in the absorption spectrum is broadened and shifted due to
incoherent and coherent interactions between metal and semiconductor
nanoparticles. At high light intensity, the absorption spectrum demonstrates a
surprising, strongly asymmetric shape. This shape originates from the coherent
inter-nanoparticle Coulomb interaction and can be viewed as a non-linear Fano
effect which is quite different from the usual linear Fano resonance.Comment: 5 pages, 5 figures, submitted to Phys. Rev. Let
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