5,535 research outputs found
Context awareness computing in smart spaces using stochastic analysis of sensor data
In building a smart space, it becomes more critical to develop a recognition system which enables to be aware of contexts, since the appropriate services can be provided under the accurate recognition. As services satisfying for desires of individual human residents are more demanding, the necessity for more sophisticated recognition algorithms is increasing. This paper proposes an approach to discover the current context by stochastically analyzing data obtained from sensors deployed in the smart space. The approach proceeds in two phases, which is to build context models and to find one context model matching the current state space, however we mainly focus on the phase building context models. Experimental validation supports the approach and approved validity
Considering the Case for Biodiversity Cycles: Reexamining the Evidence for Periodicity in the Fossil Record
Medvedev and Melott (2007) have suggested that periodicity in fossil
biodiversity may be induced by cosmic rays which vary as the Solar System
oscillates normal to the galactic disk. We re-examine the evidence for a 62
million year (Myr) periodicity in biodiversity throughout the Phanerozoic
history of animal life reported by Rohde & Mueller (2005), as well as related
questions of periodicity in origination and extinction. We find that the signal
is robust against variations in methods of analysis, and is based on
fluctuations in the Paleozoic and a substantial part of the Mesozoic.
Examination of origination and extinction is somewhat ambiguous, with results
depending upon procedure. Origination and extinction intensity as defined by RM
may be affected by an artifact at 27 Myr in the duration of stratigraphic
intervals. Nevertheless, when a procedure free of this artifact is implemented,
the 27 Myr periodicity appears in origination, suggesting that the artifact may
ultimately be based on a signal in the data. A 62 Myr feature appears in
extinction, when this same procedure is used. We conclude that evidence for a
periodicity at 62 Myr is robust, and evidence for periodicity at approximately
27 Myr is also present, albeit more ambiguous.Comment: Minor modifications to reflect final published versio
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Revisiting global fossil fuel and biofuel emissions of ethane
Recent measurements over the Northern Hemisphere indicate that the long-term decline in the atmospheric burden of ethane (C2H6) has ended and the abundance increased dramatically between 2010 and 2014. The rise in C2H6 atmospheric abundances has been attributed to oil and natural gas extraction in North America. Existing global C2H6 emission inventories are based on outdated activity maps that do not account for current oil and natural gas exploitation regions. We present an updated global C2H6 emission inventory based on 2010 satellite-derived CH4 fluxes with adjusted C2H6 emissions over the U.S. from the National Emission Inventory (NEI 2011). We contrast our global 2010 C2H6 emission inventory with one developed for 2001. The C2H6 difference between global anthropogenic emissions is subtle (7.9 versus 7.2 Tg yr−1), but the spatial distribution of the emissions is distinct. In the 2010 C2H6 inventory, fossil fuel sources in the Northern Hemisphere represent half of global C2H6 emissions and 95% of global fossil fuel emissions. Over the U.S., unadjusted NEI 2011 C2H6 emissions produce mixing ratios that are 14–50% of those observed by aircraft observations (2008–2014). When the NEI 2011 C2H6 emission totals are scaled by a factor of 1.4, the Goddard Earth Observing System Chem model largely reproduces a regional suite of observations, with the exception of the central U.S., where it continues to underpredict observed mixing ratios in the lower troposphere. We estimate monthly mean contributions of fossil fuel C2H6 emissions to ozone and peroxyacetyl nitrate surface mixing ratios over North America of ~1% and ~8%, respectively
Pain neuroscience education on YouTube.
OBJECTIVES: The Internet in general, and YouTube in particular, is now one of the most popular sources of health-related information. Pain neuroscience education has become a primary tool for managing persistent pain, based in part on the discovery that information about pain can change pain. Our objective was to examine the availability, characteristics, and content of YouTube videos that address the neuroscience of pain. METHODS: We conducted a systematic review of videos on YouTube using the search terms "pain education", "what is pain", and "pain brain" in January 2018. Videos were included if they were in English, were under 10 minutes long, and included information on the neuroscience of pain. Videos were coded for (i) descriptive characteristics (e.g., number of views, duration on YouTube), (ii) source and style, (iii) whether or not they addressed seven pre-determined target concepts of pain neuroscience education (e.g., 'Pain is not an accurate marker of tissue state'), and (iv) how engaging they were. RESULTS: We found 106 unique videos that met the inclusion criteria. The videos ranged from having four views to over five million views (Mdn = 1,163 views), with the three most highly viewed videos accounting for 75% of the total views. Animated videos were much more highly viewed than non-animated videos. Only a small number of videos had been posted by a clearly-identifiable reputable source such as an academic or medical institution (10%), although a number of videos were posted by healthcare professionals and professional medical societies. For a small number of videos (7%), the source was unclear. We found 17 videos that addressed at least one target concept of pain neuroscience science education, only nine of which were considered to be at least somewhat engaging. The target concept 'Pain is a brain output' was considered to be well addressed by the most videos (N = 11), followed by 'Pain is a protector' (N = 10). We found only one video that adequately addressed all seven target concepts of pain neuroscience education. DISCUSSION: YouTube contains a variety of videos that practitioners, patients, and families may view to access pain neuroscience education information. A small portion of these videos addressed one or more target concepts of pain neuroscience education in an engaging manner. It is yet to be determined to what extent patients are able to learn information from these videos, to what extent the videos promote behavior change, and thus to what extent the videos may be useful for clinical practice
New ophthalmosaurid ichthyosaurs from the European lower cretaceous demonstrate extensive ichthyosaur survival across the Jurassic–Cretaceous boundary
Background
Ichthyosauria is a diverse clade of marine amniotes that spanned most of the Mesozoic. Until recently, most authors interpreted the fossil record as showing that three major extinction events affected this group during its history: one during the latest Triassic, one at the Jurassic–Cretaceous boundary (JCB), and one (resulting in total extinction) at the Cenomanian-Turonian boundary. The JCB was believed to eradicate most of the peculiar morphotypes found in the Late Jurassic, in favor of apparently less specialized forms in the Cretaceous. However, the record of ichthyosaurs from the Berriasian–Barremian interval is extremely limited, and the effects of the end-Jurassic extinction event on ichthyosaurs remains poorly understood.
Methodology/Principal Findings
Based on new material from the Hauterivian of England and Germany and on abundant material from the Cambridge Greensand Formation, we name a new ophthalmosaurid, Acamptonectes densus gen. et sp. nov. This taxon shares numerous features with Ophthalmosaurus, a genus now restricted to the Callovian–Berriasian interval. Our phylogenetic analysis indicates that Ophthalmosauridae diverged early in its history into two markedly distinct clades, Ophthalmosaurinae and Platypterygiinae, both of which cross the JCB and persist to the late Albian at least. To evaluate the effect of the JCB extinction event on ichthyosaurs, we calculated cladogenesis, extinction, and survival rates for each stage of the Oxfordian–Barremian interval, under different scenarios. The extinction rate during the JCB never surpasses the background extinction rate for the Oxfordian–Barremian interval and the JCB records one of the highest survival rates of the interval.
Conclusions/Significance
There is currently no evidence that ichthyosaurs were affected by the JCB extinction event, in contrast to many other marine groups. Ophthalmosaurid ichthyosaurs remained diverse from their rapid radiation in the Middle Jurassic to their total extinction at the beginning of the Late Cretaceous
High-throughput mapping of protein occupancy identifies functional elements without the restriction of a candidate factor approach
There are a variety of in vivo and in vitro methods to determine the genome-wide specificity of a particular trans-acting factor. However there is an inherent limitation to these candidate approaches. Most biological studies focus on the regulation of particular genes, which are bound by numerous unknown trans-acting factors. Therefore, most biological inquiries would be better addressed by a method that maps all trans-acting factors that bind particular regions rather than identifying all regions bound by a particular trans-acting factor. Here, we present a high-throughput binding assay that returns thousands of unbiased measurements of complex formation on nucleic acid. We applied this method to identify transcriptional complexes that form on DNA regions upstream of genes involved in pluripotency in embryonic stem cells (ES cells) before and after differentiation. The raw binding scores, motif analysis and expression data are used to computationally reconstruct remodeling events returning the identity of the transcription factor(s) most likely to comprise the complex. The most significant remodeling event during ES cell differentiation occurred upstream of the REST gene, a transcriptional repressor that blocks neurogenesis. We also demonstrate how this method can be used to discover RNA elements and discuss applications of screening polymorphisms for allelic differences in binding
Quantum Imaging with Incoherently Scattered Light from a Free-Electron Laser
The advent of accelerator-driven free-electron lasers (FEL) has opened new
avenues for high-resolution structure determination via diffraction methods
that go far beyond conventional x-ray crystallography methods. These techniques
rely on coherent scattering processes that require the maintenance of
first-order coherence of the radiation field throughout the imaging procedure.
Here we show that higher-order degrees of coherence, displayed in the intensity
correlations of incoherently scattered x-rays from an FEL, can be used to image
two-dimensional objects with a spatial resolution close to or even below the
Abbe limit. This constitutes a new approach towards structure determination
based on incoherent processes, including Compton scattering, fluorescence
emission or wavefront distortions, generally considered detrimental for imaging
applications. Our method is an extension of the landmark intensity correlation
measurements of Hanbury Brown and Twiss to higher than second-order paving the
way towards determination of structure and dynamics of matter in regimes where
coherent imaging methods have intrinsic limitations
Can spacetime curvature induced corrections to Lamb shift be observable?
The Lamb shift results from the coupling of an atom to vacuum fluctuations of
quantum fields, so corrections are expected to arise when the spacetime is
curved since the vacuum fluctuations are modified by the presence of spacetime
curvature. Here, we calculate the curvature-induced correction to the Lamb
shift outside a spherically symmetric object and demonstrate that this
correction can be remarkably significant outside a compact massive
astrophysical body. For instance, for a neutron star or a stellar mass black
hole, the correction is 25% at a radial distance of ,
16% at and as large as 1.6% even at , where is
the mass of the object, the Newtonian constant, and the speed of light.
In principle, we can look at the spectra from a distant compact super-massive
body to find such corrections. Therefore, our results suggest a possible way of
detecting fundamental quantum effects in astronomical observations.Comment: 13 pages, 3 figures, slight title change, clarifications and more
discussions added, version to be published in JHE
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