104 research outputs found

    Radiated Ultrashort High-Power Electromagnetic Pulses Induce ATP Release in B16F10 Murine Melanoma Cells

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    Ultrawideband electromagnetic pulses with high amplitude and short duration are reported to affect several aspects of cell physiology. They are usually delivered to the living material through electrodes in small dedicated chambers. Here we showed, using a totally different experimental setup, that radiated EM pulses illuminating the living material through a specialized antenna (without any direct contact) are able to trigger a rapid release of ATP in cultured murine cells that was concomitant with a drop of intracellular AEC. Despite this rapid and strong response, we found that cell viability and clonogenicity were only slightly affected by the EMF exposure

    Comparing four interaction techniques on a simple structured navigation task using a Head-Mounted Display

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    Virtual Reality (VR) is a scientific and technical domain that can provide mediums to dive users into an interactive 3D computer-generated world. Several processes of immersion bring to user the feeling of having quit the real world and of being present in the virtual environment, physically as well as psychologically (1,2). VR must provide a coherent experience in terms of sensory, cognitive and functional information (2). Fidelity, as the objective degree of exactness with which a system reproduces real-world, is hence a key point to design immersive VR-based systems. Since the 2010’s, low-cost cave automatic virtual environment (3) and many Head-Mounted Display (HMD) are available for immersive VR. However, navigate through 3D environments displayed in HMD is still challenging because it can cause sickness and disorientation. Since techniques based on haptic devices like keyboard and joystick have been extensively explored in the past, the present study aimed to investigate the impact of the navigation technique on performance on a simple traveling-centered task and the user experience with the HMD HTC Vive. Since techniques based on haptic devices like keyboard and joystick have been extensively explored in the past, the present study aimed to investigate the impact of the navigation technique on performance on a simple traveling-centered task and the user experience with the HMD HTC Vive. We compared four continuous navigation techniques: Arms Swinging, Walking-In-Place, Pointing and Touchpad. Results on the learning effect indicated that the repetition was especially beneficial for Directional Touchpad. On the user experience, the results revealed a general discomfort of attendees with the presented systems, but they found themselves competent at the end of the experiment in the accomplishment of the proposed task. Joysticks or directional was associated to a failure in using the gaze to orientate the camera view in virtual reality

    Object recognition by intersection between adapted color histograms

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    Most of object recognition schemes fail in case of illumination changes between the color image acquisitions. One of the most widely used solutions to cope with this problem is to compare the images by means of the intersection between invariant color histograms. Unlike the classical invariant color histograms approach which independently analyzes each image, we consider each pair constituted by the query image and one of the target images constructed during the retrieval. In this paper, we propose a new approach based on color histograms which are adapted to each pair constituted by the query image and one of the target images. These adapted color histograms are determined so that their intersection is high only when the objects contained in the two images are similar. The adapted color histograms processing is based on an original model of illumination changes based on the rank measures of the pixels within the color component images.Dans cet article, nous abordons le problème de la reconnaissance des objets sous éclairage non contrôlé par la recherche de toutes les images d'une base qui contiennent le même objet que celui représenté dans une image requête. Nous nous intéressons aux problèmes soulevés par les modifications des images couleur consécutives à des changements d'illuminant. Les images considérées dans cet article contiennent un seul objet placé sur un fond uniforme et éclairé avec un illuminant qui diffère d'une image à l'autre. Les méthodes classiques basées sur des histogrammes invariants ne fournissent pas des résultats satisfaisants en termes de reconnaissance d'objets éclairés par différents illuminants. Nous proposons de traiter ce problème, non pas en analysant les images de la base indépendamment les unes des autres, mais en analysant tous les couples constitués de l'image requête et de chacune des images candidates. Plus précisément, nous proposons d'analyser chaque couple d'histogrammes couleur pour comparer le contenu de chaque couple d'images. Pour cela, la procédure détermine un couple d'histogrammes couleur dits « spécifiques » à chaque couple d'histogrammes couleur considéré, de telle sorte que l'intersection entre ces histogrammes couleur spécifiques soit élevée uniquement lorsque les deux objets contenus dans les deux images sont similaires. Cette procédure est basée sur une nouvelle hypothèse sur les conséquences d'un changement d'illuminant qui ne porte pas directement sur les couleurs des pixels, mais sur les mesures de rang des pixels

    Natural vs anthropogenic streams in Europe: History, ecology and implications for restoration, river-rewilding and riverine ecosystem services

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    This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordIn Europe and North America the prevailing model of “natural” lowland streams is incised-meandering channels with silt-clay floodplains, and this is the typical template for stream restoration. Using both published and new unpublished geological and historical data from Europe we critically review this model, show how it is inappropriate for the European context, and examine the implications for carbon sequestration and Riverine Ecosystem Services (RES) including river rewilding. This paper brings together for the first time, all the pertinent strands of evidence we now have on the long-term trajectories of floodplain system from sediment-based dating to sedaDNA. Floodplain chronostratigraphy shows that early Holocene streams were predominantly multi-channel (anabranching) systems, often choked with vegetation and relatively rarely single-channel actively meandering systems. Floodplains were either non-existent or limited to adjacent organic-filled palaeochannels, spring/valley mires and flushes. This applied to many, if not most, small to medium rivers but also major sections of the larger rivers such as the Thames, Seine, Rhône, Lower Rhine, Vistula and Danube. As shown by radiocarbon and optically stimulated luminescence (OSL) dating during the mid-late Holocene c. 4–2 ka BP, overbank silt-clay deposition transformed European floodplains, covering former wetlands and silting-up secondary channels. This was followed by direct intervention in the Medieval period incorporating weir and mill-based systems – part of a deep engagement with rivers and floodplains which is even reflected in river and floodplain settlement place names. The final transformation was the “industrialisation of channels” through hard-engineering – part of the Anthropocene great acceleration. The primary causative factor in transforming pristine floodplains was accelerated soil erosion caused by deforestation and arable farming, but with effective sediment delivery also reflecting climatic fluctuations. Later floodplain modifications built on these transformed floodplain topographies. So, unlike North America where channel-floodplain transformation was rapid, the transformation of European streams occurred over a much longer time-period with considerable spatial diversity regarding timing and kind of modification. This has had implications for the evolution of RES including reduced carbon sequestration over the past millennia. Due to the multi-faceted combination of catchment controls, ecological change and cultural legacy, it is impractical, if not impossible, to identify an originally natural condition and thus restore European rivers to their pre-transformation state (naturalisation). Nevertheless, attempts to restore to historical (pre-industrial) states allowing for natural floodplain processes can have both ecological and carbon offset benefits, as well as additional abiotic benefits such as flood attenuation and water quality improvements. This includes rewilding using beaver reintroduction which has overall positive benefits on river corridor ecology. New developments, particularly biomolecular methods offer the potential of unifying modern ecological monitoring with the reconstruction of past ecosystems and their trajectories. The sustainable restoration of rivers and floodplains designed to maximise desirable RES and natural capital must be predicated on the awareness that Anthropocene rivers are still largely imprisoned in the banks of their history and this requires acceptance of an increased complexity for the achievement and maintenance of desirable restoration goals.OSL dating from the Severn-Wye Basin was undertaken at the Geochronology Laboratories, University of Gloucestershire under grants from the EU Leader+ Programme (administered by English Heritage) and the Leverhulme Flood and Flow Project (RPG-2016-004)

    Measurement of the neutrino-oxygen neutral-current interaction cross section by observing nuclear deexcitation gamma rays

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    We report the first measurement of the neutrino-oxygen neutral-current quasielastic (NCQE) cross section gamma It is obtained by observing nuclear deexcitation. rays which follow neutrino-oxygen interactions at the Super-Kamiokande water Cherenkov detector. We use T2K data corresponding to 3.01 x 10(20) protons on target. By selecting only events during the T2K beam window and with well-reconstructed vertices in the fiducial volume, the large background rate from natural radioactivity is dramatically reduced. We observe 43 events in the 4-30 MeV reconstructed energy window, compared with an expectation of 51.0, which includes an estimated 16.2 background events. The background is primarily nonquasielastic neutral-current interactions and has only 1.2 events from natural radioactivity. The flux-averaged NCQE cross section we measure is 1.55 x 10(-38) cm(2) with a 68% confidence interval of (1.22, 2.20) x 10(-38) cm(2) at a median neutrino energy of 630 MeV, compared with the theoretical prediction of 2.01 x 10(-38) cm(2)

    Indication of Electron Neutrino Appearance from an Accelerator-Produced Off-Axis Muon Neutrino Beam

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    The T2K experiment observes indications of nu(mu) -> nu(mu) e appearance in data accumulated with 1.43 x 10(20) protons on target. Six events pass all selection criteria at the far detector. In a three-flavor neutrino oscillation scenario with |Delta m(23)(2)| = 2.4 x 10(-3) eV(2), sin(2)2 theta(23) = 1 and sin(2)2 theta(13) = 0, the expected number of such events is 1.5 +/- 0.3(syst). Under this hypothesis, the probability to observe six or more candidate events is 7 x 10(-3), equivalent to 2.5 sigma significance. At 90% C.L., the data are consistent with 0.03(0.04) < sin(2)2 theta(13) < 0.28(0.34) for delta(CP) = 0 and a normal (inverted) hierarchy

    Time projection chambers for the T2K near detectors

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    The T2K experiment is designed to study neutrino oscillation properties by directing a high intensity neutrino beam produced at J-PARC in Tokai, Japan, towards the large Super-Kamiokande detector located 295 km away, in Kamioka, Japan. The experiment includes a sophisticated near detector complex, 280 m downstream of the neutrino production target in order to measure the properties of the neutrino beam and to better understand neutrino interactions at the energy scale below a few GeV. A key element of the near detectors is the ND280 tracker, consisting of two active scintillator-bar target systems surrounded by three large time projection chambers (TPCs) for charged particle tracking. The data collected with the tracker is used to study charged current neutrino interaction rates and kinematics prior to oscillation, in order to reduce uncertainties in the oscillation measurements by the far detector. The tracker is surrounded by the former UA1/Nomad dipole magnet and the TPCs measure the charges, momenta, and particle types of charged particles passing through them. Novel features of the TPC design include its rectangular box layout constructed from composite panels, the use of bulk micromegas detectors for gas amplification, electronics readout based on a new ASIC, and a photoelectron calibration system. This paper describes the design and construction of the TPCs, the micromegas modules, the readout electronics, the gas handling system, and shows the performance of the TPCs as deduced from measurements with particle beams, cosmic rays, and the calibration system

    Gene expression analysis of overwintering mountain pine beetle larvae suggests multiple systems involved in overwintering stress, cold hardiness, and preparation for spring development

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    Cold-induced mortality has historically been a key aspect of mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae), population control, but little is known about the molecular basis for cold tolerance in this insect. We used RNA-seq analysis to monitor gene expression patterns of mountain pine beetle larvae at four time points during their overwintering period—early-autumn, late-autumn, early-spring, and late-spring. Changing transcript profiles over the winter indicates a multipronged physiological response from larvae that is broadly characterized by gene transcripts involved in insect immune responses and detoxification during the autumn. In the spring, although transcripts associated with developmental process are present, there was no particular biological process dominating the transcriptome

    Emergence of Epidemic Neisseria meningitidis Serogroup X Meningitis in Togo and Burkina Faso

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    Serogroup X meningococci (NmX) historically have caused sporadic and clustered meningitis cases in sub-Saharan Africa. To study recent NmX epidemiology, we analyzed data from population-based, sentinel and passive surveillance, and outbreak investigations of bacterial meningitis in Togo and Burkina Faso during 2006–2010. Cerebrospinal fluid specimens were analyzed by PCR. In Togo during 2006–2009, NmX accounted for 16% of the 702 confirmed bacterial meningitis cases. Kozah district experienced an NmX outbreak in March 2007 with an NmX seasonal cumulative incidence of 33/100,000. In Burkina Faso during 2007–2010, NmX accounted for 7% of the 778 confirmed bacterial meningitis cases, with an increase from 2009 to 2010 (4% to 35% of all confirmed cases, respectively). In 2010, NmX epidemics occurred in northern and central regions of Burkina Faso; the highest district cumulative incidence of NmX was estimated as 130/100,000 during March–April. Although limited to a few districts, we have documented NmX meningitis epidemics occurring with a seasonal incidence previously only reported in the meningitis belt for NmW135 and NmA, which argues for development of an NmX vaccine

    Draft genome of the mountain pine beetle, Dendroctonus ponderosae Hopkins, a major forest pest

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    Background The mountain pine beetle, Dendroctonus ponderosae Hopkins, is the most serious insect pest of western North American pine forests. A recent outbreak destroyed more than 15 million hectares of pine forests, with major environmental effects on forest health, and economic effects on the forest industry. The outbreak has in part been driven by climate change, and will contribute to increased carbon emissions through decaying forests. Results We developed a genome sequence resource for the mountain pine beetle to better understand the unique aspects of this insect's biology. A draft de novo genome sequence was assembled from paired-end, short-read sequences from an individual field-collected male pupa, and scaffolded using mate-paired, short-read genomic sequences from pooled field-collected pupae, paired-end short-insert whole-transcriptome shotgun sequencing reads of mRNA from adult beetle tissues, and paired-end Sanger EST sequences from various life stages. We describe the cytochrome P450, glutathione S-transferase, and plant cell wall-degrading enzyme gene families important to the survival of the mountain pine beetle in its harsh and nutrient-poor host environment, and examine genome-wide single-nucleotide polymorphism variation. A horizontally transferred bacterial sucrose-6-phosphate hydrolase was evident in the genome, and its tissue-specific transcription suggests a functional role for this beetle. Conclusions Despite Coleoptera being the largest insect order with over 400,000 described species, including many agricultural and forest pest species, this is only the second genome sequence reported in Coleoptera, and will provide an important resource for the Curculionoidea and other insects
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