1,223 research outputs found
Mind before matter: reversing the arrow of fundamentality
In this contribution to FQXi's essay contest 2018, I suggest that it is
sometimes a step forward to reverse our intuition on "what is fundamental", a
move that is somewhat reminiscent of the idea of noncommutative geometry. I
argue that some foundational conceptual problems in physics and related fields
motivate us to attempt such a reversal of perspective, and to take seriously
the idea that an information-theoretic notion of observer ("mind") could in
some sense be more fundamental than our intuitive idea of a physical world
("matter"). I sketch what such an approach could look like, and why it would
complement but not contradict the view that the material world is the cause of
our experience.Comment: Contribution to the 2018 FQXi essay contest "What is fundamental?
Equality of Participation Online Versus Face to Face: Condensed Analysis of the Community Forum Deliberative Methods Demonstration
Online deliberation may provide a more cost-effective and/or less inhibiting
environment for public participation than face to face (F2F). But do online
methods bias participation toward certain individuals or groups? We compare F2F
versus online participation in an experiment affording within-participants and
cross-modal comparisons. For English speakers required to have Internet access
as a condition of participation, we find no negative effects of online modes on
equality of participation (EoP) related to gender, age, or educational level.
Asynchronous online discussion appears to improve EoP for gender relative to
F2F. Data suggest a dampening effect of online environments on black
participants, as well as amplification for whites. Synchronous online voice
communication EoP is on par with F2F across individuals. But individual-level
EoP is much lower in the online forum, and greater online forum participation
predicts greater F2F participation for individuals. Measured rates of
participation are compared to self-reported experiences, and other findings are
discussed.Comment: 14 pages, 10 tables, to appear in Efthimios Tambouris, Panos
Panagiotopoulos, {\O}ystein S{\ae}b{\o}, Konstantinos Tarabanis, Michela
Milano, Theresa Pardo, and Maria Wimmer (Editors), Electronic Participation:
Proceedings of the 7th IFIP WG 8.5 International Conference, ePart 2015
(Thessaloniki, August 30-September 2), Springer LNCS Vol. 9249, 201
A guideline for analyzing circadian wheel-running behavior in rodents under different lighting conditions
Most behavioral experiments within circadian research are based on the analysis of locomotor activity. This paper introduces scientists to chronobiology by explaining the basic terminology used within the field. Furthermore, it aims to assist in designing, carrying out, and evaluating wheel-running experiments with rodents, particularly mice. Since light is an easily applicable stimulus that provokes strong effects on clock phase, the paper focuses on the application of different lighting conditions
Predicting sentence translation quality using extrinsic and language independent features
We develop a top performing model for automatic, accurate, and language independent prediction of sentence-level statistical machine translation (SMT) quality with or without looking at the translation outputs.
We derive various feature functions measuring the closeness of a given test sentence to the training data and
the difficulty of translating the sentence.
We describe \texttt{mono} feature functions that are based on statistics of only one side of the parallel
training corpora and \texttt{duo} feature functions that incorporate statistics involving both source and
target sides of the training data.
Overall, we describe novel, language independent, and SMT system extrinsic features for predicting the SMT performance, which also rank high during feature ranking evaluations.
We experiment with different learning settings, with or without looking at the translations, which help differentiate the contribution of different feature sets.
We apply partial least squares and feature subset selection, both of which improve the results and we present ranking of the top features selected for each learning setting, providing an exhaustive analysis of the extrinsic features used.
We show that by just looking at the test source sentences and not using the translation outputs at all, we can
achieve better performance than a baseline system using SMT model dependent features that generated the
translations.
Furthermore, our prediction system is able to achieve the nd best performance overall according to the official
results of the Quality Estimation Task (QET) challenge when also looking at the translation outputs.
Our representation and features achieve the top performance in QET among the models using the SVR learning model
Kank Is an EB1 Interacting Protein that Localises to Muscle-Tendon Attachment Sites in Drosophila
Little is known about how microtubules are regulated in different cell types during development. EB1 plays a central role in the regulation of microtubule plus ends. It directly binds to microtubule plus ends and recruits proteins which regulate microtubule dynamics and behaviour. We report the identification of Kank, the sole Drosophila orthologue of human Kank proteins, as an EB1 interactor that predominantly localises to embryonic attachment sites between muscle and tendon cells. Human Kank1 was identified as a tumour suppressor and has documented roles in actin regulation and cell polarity in cultured mammalian cells. We found that Drosophila Kank binds EB1 directly and this interaction is essential for Kank localisation to microtubule plus ends in cultured cells. Kank protein is expressed throughout fly development and increases during embryogenesis. In late embryos, it accumulates to sites of attachment between muscle and epidermal cells. A kank deletion mutant was generated. We found that the mutant is viable and fertile without noticeable defects. Further analysis showed that Kank is dispensable for muscle function in larvae. This is in sharp contrast to C. elegans in which the Kank orthologue VAB-19 is required for development by stabilising attachment structures between muscle and epidermal cells
Nanostructured 3D Constructs Based on Chitosan and Chondroitin Sulphate Multilayers for Cartilage Tissue Engineering
Nanostructured three-dimensional constructs combining layer-by-layer technology (LbL) and template leaching were processed and evaluated as possible support structures for cartilage tissue engineering. Multilayered constructs were formed by depositing the polyelectrolytes chitosan (CHT) and chondroitin sulphate (CS) on either bidimensional glass surfaces or 3D packet of paraffin spheres. 2D CHT/CS multi-layered constructs proved to support the attachment and proliferation of bovine chondrocytes (BCH). The technology was transposed to 3D level and CHT/CS multi-layered hierarchical scaffolds were retrieved after paraffin leaching. The obtained nanostructured 3D constructs had a high porosity and water uptake capacity of about 300%. Dynamical mechanical analysis (DMA) showed the viscoelastic nature of the scaffolds. Cellular tests were performed with the culture of BCH and multipotent bone marrow derived stromal cells (hMSCs) up to 21 days in chondrogenic differentiation media. Together with scanning electronic microscopy analysis, viability tests and DNA quantification, our results clearly showed that cells attached, proliferated and were metabolically active over the entire scaffold. Cartilaginous extracellular matrix (ECM) formation was further assessed and results showed that GAG secretion occurred indicating the maintenance of the chondrogenic phenotype and the chondrogenic differentiation of hMSCs
The APOSTEL recommendations for reporting quantitative optical coherence tomography studies
OBJECTIVE: To develop consensus recommendations for reporting of quantitative optical coherence tomography (OCT) study results.
METHODS: A panel of experienced OCT researchers (including 11 neurologists, 2 ophthalmologists, and 2 neuroscientists) discussed requirements for performing and reporting quantitative analyses of retinal morphology and developed a list of initial recommendations based on experience and previous studies. The list of recommendations was subsequently revised during several meetings of the coordinating group.
RESULTS: We provide a 9-point checklist encompassing aspects deemed relevant when reporting quantitative OCT studies. The areas covered are study protocol, acquisition device, acquisition settings, scanning protocol, funduscopic imaging, postacquisition data selection, postacquisition data analysis, recommended nomenclature, and statistical analysis.
CONCLUSIONS: The Advised Protocol for OCT Study Terminology and Elements recommendations include core items to standardize and improve quality of reporting in quantitative OCT studies. The recommendations will make reporting of quantitative OCT studies more consistent and in line with existing standards for reporting research in other biomedical areas. The recommendations originated from expert consensus and thus represent Class IV evidence. They will need to be regularly adjusted according to new insights and practices
Molecular Valves for Controlling Gas Phase Transport Made from Discrete Angstrom-Sized Pores in Graphene
An ability to precisely regulate the quantity and location of molecular flux
is of value in applications such as nanoscale 3D printing, catalysis, and
sensor design. Barrier materials containing pores with molecular dimensions
have previously been used to manipulate molecular compositions in the gas
phase, but have so far been unable to offer controlled gas transport through
individual pores. Here, we show that gas flux through discrete angstrom-sized
pores in monolayer graphene can be detected and then controlled using
nanometer-sized gold clusters, which are formed on the surface of the graphene
and can migrate and partially block a pore. In samples without gold clusters,
we observe stochastic switching of the magnitude of the gas permeance, which we
attribute to molecular rearrangements of the pore. Our molecular valves could
be used, for example, to develop unique approaches to molecular synthesis that
are based on the controllable switching of a molecular gas flux, reminiscent of
ion channels in biological cell membranes and solid state nanopores.Comment: to appear in Nature Nanotechnolog
Tissue-Specific Function of Period3 in Circadian Rhythmicity
The mammalian circadian system is composed of multiple central and peripheral clocks that are temporally coordinated to synchronize physiology and behavior with environmental cycles. Mammals have three homologs of the circadian Period gene (Per1, 2, 3). While numerous studies have demonstrated that Per1 and Per2 are necessary for molecular timekeeping and light responsiveness in the master circadian clock in the suprachiasmatic nuclei (SCN), the function of Per3 has been elusive. In the current study, we investigated the role of Per3 in circadian timekeeping in central and peripheral oscillators by analyzing PER2::LUCIFERASE expression in tissues explanted from C57BL/6J wild-type and Per3−/− mice. We observed shortening of the periods in some tissues from Per3−/− mice compared to wild-types. Importantly, the periods were not altered in other tissues, including the SCN, in Per3−/− mice. We also found that Per3-dependent shortening of endogenous periods resulted in advanced phases of those tissues, demonstrating that the in vitro phenotype is also present in vivo. Our data demonstrate that Per3 is important for endogenous timekeeping in specific tissues and those tissue-specific changes in endogenous periods result in internal misalignment of circadian clocks in Per3−/− mice. Taken together, our studies demonstrate that Per3 is a key player in the mammalian circadian system
The Rossiter-McLaughlin effect in Exoplanet Research
The Rossiter-McLaughlin effect occurs during a planet's transit. It provides
the main means of measuring the sky-projected spin-orbit angle between a
planet's orbital plane, and its host star's equatorial plane. Observing the
Rossiter-McLaughlin effect is now a near routine procedure. It is an important
element in the orbital characterisation of transiting exoplanets. Measurements
of the spin-orbit angle have revealed a surprising diversity, far from the
placid, Kantian and Laplacian ideals, whereby planets form, and remain, on
orbital planes coincident with their star's equator. This chapter will review a
short history of the Rossiter-McLaughlin effect, how it is modelled, and will
summarise the current state of the field before describing other uses for a
spectroscopic transit, and alternative methods of measuring the spin-orbit
angle.Comment: Review to appear as a chapter in the "Handbook of Exoplanets", ed. H.
Deeg & J.A. Belmont
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