469 research outputs found

    Large impact of the apoplast on somatic embryogenesis in Cyclamen persicum offers possibilities for improved developmental control in vitro

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    <p>Abstract</p> <p>Background</p> <p>Clonal propagation is highly desired especially for valuable horticultural crops. The method with the potentially highest multiplication rate is regeneration via somatic embryogenesis. However, this mode of propagation is often hampered by the occurrence of developmental aberrations and non-embryogenic callus. Therefore, the developmental process of somatic embryogenesis was analysed in the ornamental crop <it>Cyclamen persicum </it>by expression profiling, comparing different developmental stages of embryogenic cell cultures, zygotic vs. somatic embryos and embryogenic vs. non-embryogenic cell cultures.</p> <p>Results</p> <p>The analysis was based on a cDNA microarray representing 1,216 transcripts and was exemplarily validated by realtime PCR. For this purpose relative transcript abundances of homologues of a putative receptor kinase, two different glutathione S-transferases (GST), a xyloglucan endotransglycosylase (XET) and a peroxidase (POX) were quantitatively measured by realtime PCR for three different comparisons. In total, 417 genes were found to be differentially expressed. Gene Ontology annotation revealed that transcripts coding for enzymes that are active in the extracellular compartment (apoplast) were significantly overrepresented in several comparisons. The expression profiling results are underpinned by thorough histological analyses of somatic and zygotic embryos.</p> <p>Conclusions</p> <p>The putative underlying physiological processes are discussed and hypotheses on improvement of the protocol for <it>in vitro </it>somatic embryogenesis in <it>Cyclamen persicum </it>are deduced. A set of physiological markers is proposed for efficient molecular control of the process of somatic embryogenesis in <it>C. persicum</it>. The general suitability of expression profiling for the development and improvement of micropropagation methods is discussed.</p

    Real Acoustic Fields: An Audio-Visual Room Acoustics Dataset and Benchmark

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    We present a new dataset called Real Acoustic Fields (RAF) that captures real acoustic room data from multiple modalities. The dataset includes high-quality and densely captured room impulse response data paired with multi-view images, and precise 6DoF pose tracking data for sound emitters and listeners in the rooms. We used this dataset to evaluate existing methods for novel-view acoustic synthesis and impulse response generation which previously relied on synthetic data. In our evaluation, we thoroughly assessed existing audio and audio-visual models against multiple criteria and proposed settings to enhance their performance on real-world data. We also conducted experiments to investigate the impact of incorporating visual data (i.e., images and depth) into neural acoustic field models. Additionally, we demonstrated the effectiveness of a simple sim2real approach, where a model is pre-trained with simulated data and fine-tuned with sparse real-world data, resulting in significant improvements in the few-shot learning approach. RAF is the first dataset to provide densely captured room acoustic data, making it an ideal resource for researchers working on audio and audio-visual neural acoustic field modeling techniques. Demos and datasets are available on our project page: https://facebookresearch.github.io/real-acoustic-fields/Comment: Accepted to CVPR 2024. Project site: https://facebookresearch.github.io/real-acoustic-fields

    EgoCap: Egocentric Marker-less Motion Capture with Two Fisheye Cameras (Extended Abstract)

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    Marker-based and marker-less optical skeletal motion-capture methods use an outside-in arrangement of cameras placed around a scene, with viewpoints converging on the center. They often create discomfort by possibly needed marker suits, and their recording volume is severely restricted and often constrained to indoor scenes with controlled backgrounds. We therefore propose a new method for real-time, marker-less and egocentric motion capture which estimates the full-body skeleton pose from a lightweight stereo pair of fisheye cameras that are attached to a helmet or virtual-reality headset. It combines the strength of a new generative pose estimation framework for fisheye views with a ConvNet-based body-part detector trained on a new automatically annotated and augmented dataset. Our inside-in method captures full-body motion in general indoor and outdoor scenes, and also crowded scenes

    Abnormal Behaviour Of Zero Degree Δ-electron Emission On The Projectile Ionic Charge

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    The 0° δ-electron emission was investigated by an electron-projectile coincidence technique as a function of incoming and outgoing projectile charge state for 0.53 MeV u-1Cuq+ on He. The electron emission spectra vary strongly with initial and final projectile charge state. For pure ionization channels the cross sections follow for low electron energy the q2-scaling law whereas in the binary encounter regime the scaling is reversed. Ctmc calculations are in fair agreement with the experimental data. © 1991 IOP Publishing Ltd

    Widespread higher fractional anisotropy associates to better cognitive functions in individuals at ultra-high risk for psychosis

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    In schizophrenia patients, cognitive functions appear linked to widespread alterations in cerebral white matter microstructure. Here we examine patterns of associations between regional white matter and cognitive functions in individuals at ultra-high risk for psychosis. One hundred and sixteen individuals at ultra-high risk for psychosis and 49 matched healthy controls underwent 3 T magnetic resonance diffusion-weighted imaging and cognitive assessments. Group differences on fractional anisotropy were tested using tract-based spatial statistics. Group differences in cognitive functions, voxel-wise as well as regional fractional anisotropy were tested using univariate general linear modeling. Multivariate partial least squares correlation analyses tested for associations between patterns of regional fractional anisotropy and cognitive functions. Univariate analyses revealed significant impairments on cognitive functions and lower fractional anisotropy in superior longitudinal fasciculus and cingulate gyrus in individuals at ultra-high risk for psychosis. Partial least squares correlation analysis revealed different associations between patterns of regional fractional anisotropy and cognitive functions in individuals at ultra-high risk for psychosis compared to healthy controls. Widespread higher fractional anisotropy was associated with better cognitive functioning for individuals at ultra-high risk for psychosis, but not for the healthy controls. Furthermore, patterns of cognitive functions were associated with an interaction-effect on regional fractional anisotropy in fornix, medial lemniscus, uncinate fasciculus, and superior cerebellar peduncle. Aberrant associations between patterns of cognitive functions to white matter may be explained by dysmyelination

    The Glial Regenerative Response to Central Nervous System Injury Is Enabled by Pros-Notch and Pros-NFκB Feedback

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    Organisms are structurally robust, as cells accommodate changes preserving structural integrity and function. The molecular mechanisms underlying structural robustness and plasticity are poorly understood, but can be investigated by probing how cells respond to injury. Injury to the CNS induces proliferation of enwrapping glia, leading to axonal re-enwrapment and partial functional recovery. This glial regenerative response is found across species, and may reflect a common underlying genetic mechanism. Here, we show that injury to the Drosophila larval CNS induces glial proliferation, and we uncover a gene network controlling this response. It consists of the mutual maintenance between the cell cycle inhibitor Prospero (Pros) and the cell cycle activators Notch and NFκB. Together they maintain glia in the brink of dividing, they enable glial proliferation following injury, and subsequently they exert negative feedback on cell division restoring cell cycle arrest. Pros also promotes glial differentiation, resolving vacuolization, enabling debris clearance and axonal enwrapment. Disruption of this gene network prevents repair and induces tumourigenesis. Using wound area measurements across genotypes and time-lapse recordings we show that when glial proliferation and glial differentiation are abolished, both the size of the glial wound and neuropile vacuolization increase. When glial proliferation and differentiation are enabled, glial wound size decreases and injury-induced apoptosis and vacuolization are prevented. The uncovered gene network promotes regeneration of the glial lesion and neuropile repair. In the unharmed animal, it is most likely a homeostatic mechanism for structural robustness. This gene network may be of relevance to mammalian glia to promote repair upon CNS injury or disease

    Performance of the First ANTARES Detector Line

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    In this paper we report on the data recorded with the first Antares detector line. The line was deployed on the 14th of February 2006 and was connected to the readout two weeks later. Environmental data for one and a half years of running are shown. Measurements of atmospheric muons from data taken from selected runs during the first six months of operation are presented. Performance figures in terms of time residuals and angular resolution are given. Finally the angular distribution of atmospheric muons is presented and from this the depth profile of the muon intensity is derived.Comment: 14 pages, 9 figure

    Detailed spectral and morphological analysis of the shell type SNR RCW 86

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    Aims: We aim for an understanding of the morphological and spectral properties of the supernova remnant RCW~86 and for insights into the production mechanism leading to the RCW~86 very high-energy gamma-ray emission. Methods: We analyzed High Energy Spectroscopic System data that had increased sensitivity compared to the observations presented in the RCW~86 H.E.S.S. discovery publication. Studies of the morphological correlation between the 0.5-1~keV X-ray band, the 2-5~keV X-ray band, radio, and gamma-ray emissions have been performed as well as broadband modeling of the spectral energy distribution with two different emission models. Results:We present the first conclusive evidence that the TeV gamma-ray emission region is shell-like based on our morphological studies. The comparison with 2-5~keV X-ray data reveals a correlation with the 0.4-50~TeV gamma-ray emission.The spectrum of RCW~86 is best described by a power law with an exponential cutoff at Ecut=(3.5±1.2stat)E_{cut}=(3.5\pm 1.2_{stat}) TeV and a spectral index of Γ\Gamma~1.6±0.21.6\pm 0.2. A static leptonic one-zone model adequately describes the measured spectral energy distribution of RCW~86, with the resultant total kinetic energy of the electrons above 1 GeV being equivalent to \sim0.1\% of the initial kinetic energy of a Type I a supernova explosion. When using a hadronic model, a magnetic field of BB~100μ\muG is needed to represent the measured data. Although this is comparable to formerly published estimates, a standard E2^{-2} spectrum for the proton distribution cannot describe the gamma-ray data. Instead, a spectral index of Γp\Gamma_p~1.7 would be required, which implies that ~7×1049/ncm37\times 10^{49}/n_{cm^{-3}}erg has been transferred into high-energy protons with the effective density ncm3=n/1n_{cm^{-3}}=n/ 1 cm^-3. This is about 10\% of the kinetic energy of a typical Type Ia supernova under the assumption of a density of 1~cm^-3.Comment: accepted for publication by A&
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