261 research outputs found

    Lidar detection of metallic species at the mesopause level

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    The measurement alkali species present in the atomic form at the mesopause level has been performed by lidar for more than ten years. Atomic and ionic calcium density profiles are obtained for 3 years by the same technique in the visible range, at 423 nm for atomic calcium, and 393 nm for ionic calcium Ca(+). The experimental set-up and the preliminary results have been presented elsewhere. The 423 nm wavelength is directly obtained by the emission of a dye laser pumped by the third harmonic of a Nd-YAG laser. For the generation of the 393 nm wavelength, frequency mixing was used: the emission at 624 nm of a dye laser pumped by the 2nd harmonic of a Nd-Yag laser is mixed with the fundamental infrared emission (remaining after frequency doubling), in a non-linear KDP crystal, which gives the 393 nm emission. The behavior of the two atomic species, calcium and sodium, which are in the same altitude range are compared. For 45% of the observations, no ionic calcium was detected: the ionic calcium abundance was thus below the detection threshold. Contrasting with the density profiles of the atomic species, sodium and calcium, the ionic calcium profile present important variations on small time scales. The main characteristics of theatomic and ionic calcium behaviors that can be deduced from the measurements made are given

    Cross-dimensional Weighting for Aggregated Deep Convolutional Features

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    We propose a simple and straightforward way of creating powerful image representations via cross-dimensional weighting and aggregation of deep convolutional neural network layer outputs. We first present a generalized framework that encompasses a broad family of approaches and includes cross-dimensional pooling and weighting steps. We then propose specific non-parametric schemes for both spatial- and channel-wise weighting that boost the effect of highly active spatial responses and at the same time regulate burstiness effects. We experiment on different public datasets for image search and show that our approach outperforms the current state-of-the-art for approaches based on pre-trained networks. We also provide an easy-to-use, open source implementation that reproduces our results.Comment: Accepted for publications at the 4th Workshop on Web-scale Vision and Social Media (VSM), ECCV 201

    Pulsed mononode dye laser developed for a geophysical application

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    Following the extension of the lidar technique in the study of the atmosphere, the necessity of having a high power pulsed laser beam with a narrowed bandwidth and the possibility of selecting a particular wavelength within a certain spectral region arises. With the collaboration of others, a laser cavity using the multiwave Fizeau wedge (MWFW) was developed. Using the classical method of beam amplification with the aid of different stages, a new pulsed dye laser device was designed. The originality resides in the use of reflecting properties of the MFWF. Locally a plan wave coming with a particular angular incidence is reflected with a greater than unity coefficient; this is the consequence of the wedge angle which doubles the participation of every ray in the interferometric process. This dye laser operation and advantages are discussed. The feasibility of different geophysical applications envisageable with this laser is discussed

    Risks linked to accidental inoculation of humans with veterinary vaccines: a 7-year prospective study

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    AIM: Accidental inoculation of humans with veterinary vaccines can lead to early and late complications. The aim of our study is to describe these complications and their risk factors. METHODS: Prospective observational study conducted from 2007 to 2014 at Angers University Hospital\u27s Poison Control Centre. The endpoints examined were: early and late locoregional complications, surgical treatment, and absence from work. The statistical analysis was based on a multivariate analysis. DISCUSSION: The presence of mineral oil adjuvants, the injection of the vaccine under pressure and injection in joint and tendon of the hand significantly increased early locoregional complications and surgery but only the presence of mineral oil adjuvant increased significantly late locoregional complications at one month. Absence from work is significantly correlated to the site of injection and the presence of mineral oil adjuvant. CONCLUSION: It is important to know about the contents of the veterinary vaccine in order to anticipate early and late complications that may arise (particularly due to the presence of mineral oil adjuvants). Special attention must also be given do the site of injection. We think that any accidental injection of veterinary vaccine into humans, especially those containing mineral oils, must lead to an early medical consultation. This must also be indicated on the product

    PlaNet - Photo Geolocation with Convolutional Neural Networks

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    Is it possible to build a system to determine the location where a photo was taken using just its pixels? In general, the problem seems exceptionally difficult: it is trivial to construct situations where no location can be inferred. Yet images often contain informative cues such as landmarks, weather patterns, vegetation, road markings, and architectural details, which in combination may allow one to determine an approximate location and occasionally an exact location. Websites such as GeoGuessr and View from your Window suggest that humans are relatively good at integrating these cues to geolocate images, especially en-masse. In computer vision, the photo geolocation problem is usually approached using image retrieval methods. In contrast, we pose the problem as one of classification by subdividing the surface of the earth into thousands of multi-scale geographic cells, and train a deep network using millions of geotagged images. While previous approaches only recognize landmarks or perform approximate matching using global image descriptors, our model is able to use and integrate multiple visible cues. We show that the resulting model, called PlaNet, outperforms previous approaches and even attains superhuman levels of accuracy in some cases. Moreover, we extend our model to photo albums by combining it with a long short-term memory (LSTM) architecture. By learning to exploit temporal coherence to geolocate uncertain photos, we demonstrate that this model achieves a 50% performance improvement over the single-image model

    Regional processing of the N- and C-terminal domains of proopiomelanocortin in monkey pituitary and brain

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    The total content and extent of processing of the [gamma]3MSH and [beta]-endorphin-containing N- and C-terminal domains of proopiomelanocortin were determined in the anterior and intermediate lobes of the pituitaries and in 11 regions of the brains of three Rhesus monkeys. Most immunoreactive [gamma]3MSH and [beta]-endorphin was located in the pituitary lobes, although significant amounts were also found in several brain regions. Sephadex column chromatography revealed that [gamma]3MSH immunoreactivity was found primarily as 4K and 9K forms; no [gamma]1MSH was detected. [beta]-Endorphin immunoreactivity was found as [beta]-endorphin, [beta]-lipotropin, and as a 5K form which may represent [beta]-endorphin extended N-terminally by part or all of [beta]-MSH. In the anterior lobe of the pituitary, the predominant products were 9K [gamma]3MSH and [beta]-lipotropin; in the intermediate lobe, more processed forms (4K [gamma]3MSH, [beta]-endorphin and 5K [beta]-endorphin) appeared to be preferentially stored. The pattern of processing in various brain regions was similar to that of the intermediate lobe of the pituitary.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27343/1/0000368.pd

    Ferroelectricity in a quasiamorphous ultrathin BaTiO3 film

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    Until now, the quasiamorphous (QA) phase in BaTiO3 (BTO), SrTiO3 (STO), and BaZrO3 was achieved by pulling a thick film through a steep temperature gradient. Here, we show that a room-temperature deposited ultrathin film, subsequently annealed in O-2 can also produce a QA phase. The atomic, electronic, and ferroelectric (FE) structure of a QA, ultrathin BTO grown on STO were studied by x-ray diffraction (XRD), x-ray photoelectron diffraction (XPD), x-ray photoelectron spectroscopy (XPS), and piezoforce microscopy (PFM). The absence of long-range order is confirmed by in-and out-of-plane XRD as well as Ti 2p XPD. FE polarized domains with good retention have been successfully written into the QA film and exhibit a clear P-E hysteresis loop. Substrate clamping frustrates volume expansion during annealing leading to a QA film. Photoelectron spectroscopy confirms a similar overall electronic structure as for thicker films but with some significant differences. Simple charge-transfer arguments are not sufficient to explain the high-resolution core-level spectra. Ba, Ti, and O all show components associated with a surface region. We suggest that the observation of such a component in the Ti 2p spectrum is linked with the high dynamic charge tensor induced by the large off-center displacement of the Ti ion.8420French National Research Agency (ANR) [ANR-10-BLAN-1012]CEAFrench National Research Agency (ANR) [ANR-10-BLAN-1012

    Measurement of the Longitudinal Spin Transfer to Lambda and Anti-Lambda Hyperons in Polarised Muon DIS

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    The longitudinal polarisation transfer from muons to lambda and anti-lambda hyperons, D_LL, has been studied in deep inelastic scattering off an unpolarised isoscalar target at the COMPASS experiment at CERN. The spin transfers to lambda and anti-lambda produced in the current fragmentation region exhibit different behaviours as a function of x and xF . The measured x and xF dependences of D^lambda_LL are compatible with zero, while D^anti-lambda_LL tends to increase with xF, reaching values of 0.4 - 0.5. The resulting average values are D^lambda_LL = -0.012 +- 0.047 +- 0.024 and D^anti-lambda_LL = 0.249 +- 0.056 +- 0.049. These results are discussed in the frame of recent model calculations.Comment: 13 pages, 7 figure

    First Measurement of Chiral Dynamics in \pi^- \gamma -> \pi^- \pi^- \pi^+

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    The COMPASS collaboration at CERN has investigated the \pi^- \gamma -> \pi^- \pi^- \pi^+ reaction at center-of-momentum energy below five pion masses, sqrt(s) < 5 m(\pi), embedded in the Primakoff reaction of 190 GeV pions impinging on a lead target. Exchange of quasi-real photons is selected by isolating the sharp Coulomb peak observed at smallest momentum transfers, t' < 0.001 (GeV/c)^2. Using partial-wave analysis techniques, the scattering intensity of Coulomb production described in terms of chiral dynamics and its dependence on the 3\pi-invariant mass m(3\pi) = sqrt(s) were extracted. The absolute cross section was determined in seven bins of s\sqrt{s} with an overall precision of 20%. At leading order, the result is found to be in good agreement with the prediction of chiral perturbation theory over the whole energy range investigated.Comment: 10 pages, 5 figure
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