3,629 research outputs found
A comparison of vertical thermospheric winds from Fabry-Perot Interferometer measurements over a 50 km baseline
Bimetallic Cooperativity in Proton Reduction with an Amido‐Bridged Cobalt Catalyst
The bimetallic catalyst [CoII2(L1)(bpy)2]ClO4 (1), in which L1 is an [NN′2O2] fused ligand, efficiently reduced H+ to H2 in CH3CN in the presence of 100 equiv of HOAc with a turnover number of 18 and a Faradaic efficiency of 94 % after 3 h of bulk electrolysis at −1.6 V (vs. Ag/AgCl). This observation allowed the proposal that this bimetallic cooperativity is associated with distance, angle, and orbital alignment of the two Co centers, as promoted by the unique Co−Namido−Co environment offered by L1. Experimental results revealed that the parent [CoIICoII] complex undergoes two successive metal‐based 1 e− reductions to generate the catalytically active species [CoICoI], and DFT calculations suggested that addition of a proton to one CoI triggers a cooperative 1 e− transfer by each of these CoI centers. This 2 e− transfer is an alternative route to generate a more reactive [CoII(CoII−H−)] hydride, thus avoiding the CoIII−H− required in monometallic species. This [CoII(CoII−H−)] species then accepts another H+ to release H2
A comparison of thermospheric winds and temperatures from Fabry-Perot Interferometer and EISCAT Radar measurements with models
Logsig-RNN: a novel network for robust and efficient skeleton-based action recognition
This paper contributes to the challenge of skeleton-based human action recognition in
videos. The key step is to develop a generic network architecture to extract discriminative
features for the spatio-temporal skeleton data. In this paper, we propose a novel module,
namely Logsig-RNN, which is the combination of the log-signature layer and recurrent
type neural networks (RNNs). The former one comes from the mathematically principled
technology of signatures and log-signatures as representations for streamed data, which
can manage high sample rate streams, non-uniform sampling and time series of variable
length. It serves as an enhancement of the recurrent layer, which can be conveniently
plugged into neural networks. Besides we propose two path transformation layers to
significantly reduce path dimension while retaining the essential information fed into
the Logsig-RNN module. (The network architecture is illustrated in Figure 1 (Right).)
Finally, numerical results demonstrate that replacing the RNN module by the LogsigRNN module in SOTA networks consistently improves the performance on both Chalearn
gesture data and NTU RGB+D 120 action data in terms of accuracy and robustness.
In particular, we achieve the state-of-the-art accuracy on Chalearn2013 gesture data by
combining simple path transformation layers with the Logsig-RNN
Genetic testing for inherited retinal degenerations: Triumphs and tribulations
Inherited retinal degenerations (IRDs) are a genotypically and phenotypically diverse group of conditions. Great strides have been made toward identifying the genetic basis for these conditions over the last 30 years—more than 270 different genes involved in syndromic and nonsyndromic forms of retinal dystrophies have now been identified. The identification of these genes and the improvement of clinical laboratory techniques have led to the identification of the genetic basis of disease in 56–76% of patients with IRDs through next generation sequencing and copy number variant analysis. Genetic testing is an essential part of clinical care for patients affected with IRDs and is required to confirm the diagnosis, understand the inheritance of the condition, and determine eligibility for gene‐specific treatments or clinical trials. Despite the success achieved in determining the genetic cause of these conditions, several challenges remain, which must be considered when providing genetic testing and genetic counseling to patients. For this reason, an integrated team of ophthalmic and genetic clinicians who are familiar with these challenges is necessary to provide optimal comprehensive care to these patients.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162692/2/ajmgc31835.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162692/1/ajmgc31835_am.pd
Chandra X-ray Observatory Arcsecond Imaging of the Young, Oxygen-rich Supernova Remnant 1E0102.2-7219
We present observations of the young, Oxygen-rich supernova remnant
1E0102.2-7219 taken by the Chandra X-ray Observatory during Chandra's Orbital
Activation and Checkout phase. The boundary of the blast wave shock is clearly
seen for the first time, allowing the diameter of the remnant and the mean
blast wave velocity to be determined accurately. The prominent X-ray bright
ring of material may be the result of the reverse shock encountering ejecta;
the radial variation of O VII vs. O VIII emission indicates an ionizing shock
propagating inwards, possibly through a strong density gradient in the ejecta.
We compare the X-ray emission to Australia Telescope Compact Array 6 cm radio
observations (Amy and Ball) and to archival Hubble Space Telescope [O III]
observations. The ring of radio emission is predominantly inward of the outer
blast wave, consistent with an interpretation as synchrotron radiation
originating behind the blast wave, but outward of the bright X-ray ring of
emission. Many (but not all) of the prominent optical filaments are seen to
correspond to X-ray bright regions. We obtain an upper limit of ~9e33 erg/s (3
sigma) on any potential pulsar X-ray emission from the central region.Comment: Accepted for pulication in Ap. J. Letters. 4 pages, 6 figures (one
color figure). Formatted with emulateapj5. Revised to incorporate copyediting
changes. High-resolution postscript (3.02MB) and tiff versions of the color
figure are available from
http://chandra.harvard.edu/photo/cycle1/0015multi/index.htm
Joint Proceedings of the 4th International Workshop on Linked Media and the 3rd Developers Hackshop co-located with the 13th Extended Semantic Web Conference ESWC 2016
Exploring the inner region of Type 1 AGNs with the Keck interferometer
The exploration of extragalactic objects with long-baseline interferometers
in the near-infrared has been very limited. Here we report successful
observations with the Keck interferometer at K-band (2.2 um) for four Type 1
AGNs, namely NGC4151, Mrk231, NGC4051, and the QSO IRAS13349+2438 at z=0.108.
For the latter three objects, these are the first long-baseline interferometric
measurements in the infrared. We detect high visibilities (V^2 ~ 0.8-0.9) for
all the four objects, including NGC4151 for which we confirm the high V^2 level
measured by Swain et al.(2003). We marginally detect a decrease of V^2 with
increasing baseline lengths for NGC4151, although over a very limited range,
where the decrease and absolute V^2 are well fitted with a ring model of radius
0.45+/-0.04 mas (0.039+/-0.003 pc). Strikingly, this matches independent radius
measurements from optical--infrared reverberations that are thought to be
probing the dust sublimation radius. We also show that the effective radius of
the other objects, obtained from the same ring model, is either roughly equal
to or slightly larger than the reverberation radius as a function of AGN
luminosity. This suggests that we are indeed partially resolving the dust
sublimation region. The ratio of the effective ring radius to the reverberation
radius might also give us an approximate probe for the radial structure of the
inner accreting material in each object. This should be scrutinized with
further observations.Comment: accepted for publication in A&A Letter
Extrapolating EISCAT Pedersen conductances to other parts of the sky using ground-based TV auroral images
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