Traveling Granular Segregation Patterns in a Long Drum Mixer

Mixtures of granular media often exhibit size segregation along the axis of a partially-filled, horizontal, rotating cylinder. Previous experiments have observed axial bands of segregation that grow from concentration fluctuations and merge in a manner analogous to spinodal decomposition. We have observed that a new dynamical state precedes this effect in certain mixtures: bi-directional traveling waves. By preparing initial conditions, we found that the wave speed decreased with wavelength. Such waves appear to be inconsistent with simple PDE models which are first order in time.Comment: 11 page

Microcraters in aluminum foils exposed by Stardust

We will present preliminary results on the nature and size frequency distribution of microcraters that formed in aluminum foils during the flyby of comet Wild 2 by the Stardust spacecraft

Characterization of ion/electron beam induced deposition of electrical contacts at the sub-{\mu}m scale

We investigate the fabrication of electrical contacts using ion- and electron-beam induced deposition of platinum at the sub-\mu m scale. Halos associated with the metal surface decoration are characterized electrically in the 0.05-2 \mu m range using transport measurements, conducting atomic force microscopy and Kelvin probe microscopy. In contrast with IBID, EBID electrodes exhibit weakly conductive halos at the sub-\mu m scale, and can thus be used to achieve resist-free electrical contacts for transport measurements at the sub-\mu m scale. Four-point transport measurements using \mu m-spaced EBID contacts are provided in the case of a multiwalled carbon nanotube

Three-dimensional random Voronoi tessellations: From cubic crystal lattices to Poisson point processes

We perturb the SC, BCC, and FCC crystal structures with a spatial Gaussian noise whose adimensional strength is controlled by the parameter a, and analyze the topological and metrical properties of the resulting Voronoi Tessellations (VT). The topological properties of the VT of the SC and FCC crystals are unstable with respect to the introduction of noise, because the corresponding polyhedra are geometrically degenerate, whereas the tessellation of the BCC crystal is topologically stable even against noise of small but finite intensity. For weak noise, the mean area of the perturbed BCC and FCC crystals VT increases quadratically with a. In the case of perturbed SCC crystals, there is an optimal amount of noise that minimizes the mean area of the cells. Already for a moderate noise (a>0.5), the properties of the three perturbed VT are indistinguishable, and for intense noise (a>2), results converge to the Poisson-VT limit. Notably, 2-parameter gamma distributions are an excellent model for the empirical of of all considered properties. The VT of the perturbed BCC and FCC structures are local maxima for the isoperimetric quotient, which measures the degre of sphericity of the cells, among space filling VT. In the BCC case, this suggests a weaker form of the recentluy disproved Kelvin conjecture. Due to the fluctuations of the shape of the cells, anomalous scalings with exponents >3/2 is observed between the area and the volumes of the cells, and, except for the FCC case, also for a->0. In the Poisson-VT limit, the exponent is about 1.67. As the number of faces is positively correlated with the sphericity of the cells, the anomalous scaling is heavily reduced when we perform powerlaw fits separately on cells with a specific number of faces

Linking cause and effect: Nanoscale vibrational spectroscopy of space weathering from asteroid Ryugu

Airless bodies are subjected to space-weathering effects that modify the first few microns of their surface. Therefore, understanding their impact on the optical properties of asteroids is key to the interpretation of their color variability and infrared reflectance observations. The recent Hayabusa2 sample return mission to asteroid Ryugu offers the first opportunity to study these effects, in the case of the most abundant spectral type among the main-asteroid belt, C-type objects. This study employs vibrational electron energy-loss spectroscopy in the transmission electron microscope to achieve the spatial resolution required to measure the distinct mid-infrared spectral signature of Ryugu's space-weathered surface. The comparison with the spectrum of the pristine underlying matrix reveals the loss of structural -OH and C-rich components in the space-weathered layers, providing direct experimental evidence that exposure to the space environment tends to mask the optical signatures of phyllosilicates and carbonaceous matter. Our findings should contribute to rectifying potential underestimations of water and carbon content of C-type asteroids when studied through remote sensing with new-generation telescopes.The Hayabusa2 project has been developed and led by JAXA in collaboration with Deutsches Zentrum für Luft- und Raumfahrt (DLR) and Centre national d'études spatiales (CNES), and supported by NASA and Australian Space Agency (ASA). We thank all the members of the Hayabusa2 project for their technical and scientific contributions. This work was carried out on the electron microscopy facility of the Advanced Characterization Platform of the Chevreul Institute, University of Lille—CNRS. This project has been funded by ISITE ULNE and the "Métropole Européenne de Lille" through the "TEM-Aster project," the LARCAS ANR (Reference No. SAN-22199). It has also been funded by in part by the National Agency for Research (ANR) under the program of future investment TEMPOS-CHROMATEM (Reference No. ANR-10-EQPX-50). Micro-infrared spectroscopy was performed at the Institut de Planétologie et d'Astrophysique de Grenoble (IPAG). European Union's Horizon 2020 research and innovation program under grant Agreements No. 823717 (ESTEEM3). The Chevreul Institute is thanked for its help in the development of this work through the CHEMACT project supported by the "Ministère de l'Enseignement Supérieur de la Recherche et de l'Innovation," the region "Hauts-de-France" and the "Métropole Européenne de Lille." JSPS KAKENHI grant numbers related to this study are 19H00725, 19K0094, and 21H05424. This research was supported by the H2020 European Research Council (ERC) (SOLARYS ERC-CoG2017-771691). We acknowledge the funding by the Spanish University Ministry and Next Generation EU through a Margarita Salas fellowship.Peer reviewe

Linking Cause and Effect: Nanoscale Vibrational Spectroscopy of Space Weathering from Asteroid Ryugu

Airless bodies are subjected to space-weathering effects that modify the first few microns of their surface. Therefore, understanding their impact on the optical properties of asteroids is key to the interpretation of their color variability and infrared reflectance observations. The recent Hayabusa2 sample return mission to asteroid Ryugu offers the first opportunity to study these effects, in the case of the most abundant spectral type among the main-asteroid belt, C-type objects. This study employs vibrational electron energy-loss spectroscopy in the transmission electron microscope to achieve the spatial resolution required to measure the distinct mid-infrared spectral signature of Ryugu's space-weathered surface. The comparison with the spectrum of the pristine underlying matrix reveals the loss of structural -OH and C-rich components in the space-weathered layers, providing direct experimental evidence that exposure to the space environment tends to mask the optical signatures of phyllosilicates and carbonaceous matter. Our findings should contribute to rectifying potential underestimations of water and carbon content of C-type asteroids when studied through remote sensing with new-generation telescopes

Bone marrow niche trafficking of miR-126 controls the self-renewal of leukemia stem cells in chronic myelogenous leukemia

Leukemia stem cells (LSCs) in individuals with chronic myelogenous leukemia (CML) (hereafter referred to as CML LSCs) are responsible for initiating and maintaining clonal hematopoiesis. These cells persist in the bone marrow (BM) despite effective inhibition of BCR–ABL kinase activity by tyrosine kinase inhibitors (TKIs). Here we show that although the microRNA (miRNA) miR-126 supported the quiescence, self-renewal and engraftment capacity of CML LSCs, miR-126 levels were lower in CML LSCs than in long-term hematopoietic stem cells (LT-HSCs) from healthy individuals. Downregulation of miR-126 levels in CML LSCs was due to phosphorylation of Sprouty-related EVH1-domain-containing 1 (SPRED1) by BCR–ABL, which led to inhibition of the RAN–exportin-5–RCC1 complex that mediates miRNA maturation. Endothelial cells (ECs) in the BM supply miR-126 to CML LSCs to support quiescence and leukemia growth, as shown using mouse models of CML in which Mir126a (encoding miR-126) was conditionally knocked out in ECs and/or LSCs. Inhibition of BCR–ABL by TKI treatment caused an undesired increase in endogenous miR-126 levels, which enhanced LSC quiescence and persistence. Mir126a knockout in LSCs and/or ECs, or treatment with a miR-126 inhibitor that targets miR-126 expression in both LSCs and ECs, enhanced the in vivo anti-leukemic effects of TKI treatment and strongly diminished LSC leukemia-initiating capacity, providing a new strategy for the elimination of LSCs in individuals with CML

Role of P2 purinergic receptors in synaptic transmission under normoxic and ischaemic conditions in the CA1 region of rat hippocampal slices

The role of ATP and its stable analogue ATPγS [adenosine-5′-o-(3-thio)triphosphate] was studied in rat hippocampal neurotransmission under normoxic conditions and during oxygen and glucose deprivation (OGD). Field excitatory postsynaptic potentials (fEPSPs) from the dendritic layer or population spikes (PSs) from the soma were extracellularly recorded in the CA1 area of the rat hippocampus. Exogenous application of ATP or ATPγS reduced fEPSP and PS amplitudes. In both cases the inhibitory effect was blocked by the selective A1 adenosine receptor antagonist DPCPX (8-cyclopentyl-1,3-dipropylxanthine) and was potentiated by different ecto-ATPase inhibitors: ARL 67156 (6-N,N-diethyl-D-β,γ-dibromomethylene), BGO 136 (1-hydroxynaphthalene-3,6-disulfonate) and PV4 [hexapotassium dihydrogen monotitanoundecatungstocobaltate(II) tridecahydrate, K6H2[TiW11CoO40]·13H2O]. ATPγS-mediated inhibition was reduced by the P2 antagonist suramin [8-(3-benzamido-4-methylbenzamido)naphthalene-1,3,5-trisulfonate] at the somatic level and by other P2 blockers, PPADS (pyridoxalphosphate-6-azophenyl-2′,4′-disulfonate) and MRS 2179 (2′-deoxy-N6-methyladenosine 3′,5′-bisphosphate), at the dendritic level. After removal of both P2 agonists, a persistent increase in evoked synaptic responses was recorded both at the dendritic and somatic levels. This effect was prevented in the presence of different P2 antagonists. A 7-min OGD induced tissue anoxic depolarization and was invariably followed by irreversible loss of fEPSP. PPADS, suramin, MRS2179 or BBG (brilliant blue G) significantly prevented the irreversible failure of neurotransmission induced by 7-min OGD. Furthermore, in the presence of these P2 antagonists, the development of anoxic depolarization was blocked or significantly delayed. Our results indicate that P2 receptors modulate CA1 synaptic transmission under normoxic conditions by eliciting both inhibitory and excitatory effects. In the same brain region, P2 receptor stimulation plays a deleterious role during a severe OGD insult

First TILLING Platform in Cucurbita pepo: A New Mutant Resource for Gene Function and Crop Improvement

Although the availability of genetic and genomic resources for Cucurbita pepo has increased significantly, functional genomic resources are still limited for this crop. In this direction, we have developed a high throughput reverse genetic tool: the first TILLING (Targeting Induced Local Lesions IN Genomes) resource for this species. Additionally, we have used this resource to demonstrate that the previous EMS mutant population we developed has the highest mutation density compared with other cucurbits mutant populations. The overall mutation density in this first C. pepo TILLING platform was estimated to be 1/133 Kb by screening five additional genes. In total, 58 mutations confirmed by sequencing were identified in the five targeted genes, thirteen of which were predicted to have an impact on the function of the protein. The genotype/phenotype correlation was studied in a peroxidase gene, revealing that the phenotype of seedling homozygous for one of the isolated mutant alleles was albino. These results indicate that the TILLING approach in this species was successful at providing new mutations and can address the major challenge of linking sequence information to biological function and also the identification of novel variation for crop breeding.Financial support was provided by the Spanish Project INIA (Instituto Nacional de Investigacion y Tecnologia Agraria y Almentaria) RTA2011-00044C02-01, the ANR MELODY (ANR-11-BSV7-0024), the European Research Council (ERCSEXYPARTH), FEDER, and FSE funds. NVD has been awarded a grant by the Andalusian Institute of Agronomy Research IFAPA. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Vicente-Dolera, N.; Troadec, C.; Moya, M.; Río-Celestino, MD.; Pomares-Viciana, T.; Bendahmane, A.; Picó Sirvent, MB.... (2014). First TILLING Platform in Cucurbita pepo: A New Mutant Resource for Gene Function and Crop Improvement. PLoS ONE. 9(11):112743-112743. https://doi.org/10.1371/journal.pone.0112743S112743112743911Paris, H. S., Yonash, N., Portnoy, V., Mozes-Daube, N., Tzuri, G., & Katzir, N. (2002). Assessment of genetic relationships in Cucurbita pepo (Cucurbitaceae) using DNA markers. Theoretical and Applied Genetics, 106(6), 971-978. doi:10.1007/s00122-002-1157-0Parry, M. A. J., Madgwick, P. J., Bayon, C., Tearall, K., Hernandez-Lopez, A., Baudo, M., … Phillips, A. L. (2009). Mutation discovery for crop improvement. Journal of Experimental Botany, 60(10), 2817-2825. doi:10.1093/jxb/erp189Gilchrist, E., & Haughn, G. (2010). Reverse genetics techniques: engineering loss and gain of gene function in plants. Briefings in Functional Genomics, 9(2), 103-110. doi:10.1093/bfgp/elp059McCallum, C. M., Comai, L., Greene, E. A., & Henikoff, S. (2000). Targeting Induced LocalLesions IN Genomes (TILLING) for Plant Functional Genomics. Plant Physiology, 123(2), 439-442. doi:10.1104/pp.123.2.439Colbert, T., Till, B. J., Tompa, R., Reynolds, S., Steine, M. N., Yeung, A. T., … Henikoff, S. (2001). High-Throughput Screening for Induced Point Mutations. Plant Physiology, 126(2), 480-484. doi:10.1104/pp.126.2.480Wang, T. L., Uauy, C., Robson, F., & Till, B. (2012). TILLINGin extremis. Plant Biotechnology Journal, 10(7), 761-772. doi:10.1111/j.1467-7652.2012.00708.xDong, C., Dalton-Morgan, J., Vincent, K., & Sharp, P. (2009). A Modified TILLING Method for Wheat Breeding. The Plant Genome Journal, 2(1), 39. doi:10.3835/plantgenome2008.10.0012Uauy, C., Paraiso, F., Colasuonno, P., Tran, R. K., Tsai, H., Berardi, S., … Dubcovsky, J. (2009). A modified TILLING approach to detect induced mutations in tetraploid and hexaploid wheat. BMC Plant Biology, 9(1), 115. doi:10.1186/1471-2229-9-115Kumar, A. P., Boualem, A., Bhattacharya, A., Parikh, S., Desai, N., Zambelli, A., … Bendahmane, A. (2013). SMART -- Sunflower Mutant population And Reverse genetic Tool for crop improvement. BMC Plant Biology, 13(1), 38. doi:10.1186/1471-2229-13-38Kurowska, M., Daszkowska-Golec, A., Gruszka, D., Marzec, M., Szurman, M., Szarejko, I., & Maluszynski, M. (2011). TILLING - a shortcut in functional genomics. Journal of Applied Genetics, 52(4), 371-390. doi:10.1007/s13353-011-0061-1Rigola, D., van Oeveren, J., Janssen, A., Bonné, A., Schneiders, H., van der Poel, H. J. A., … van Eijk, M. J. T. (2009). High-Throughput Detection of Induced Mutations and Natural Variation Using KeyPoint™ Technology. PLoS ONE, 4(3), e4761. doi:10.1371/journal.pone.0004761González, M., Xu, M., Esteras, C., Roig, C., Monforte, A. J., Troadec, C., … Picó, B. (2011). Towards a TILLING platform for functional genomics in Piel de Sapo melons. BMC Research Notes, 4(1). doi:10.1186/1756-0500-4-289Elias, R., Till, B. J., Mba, C., & Al-Safadi, B. (2009). Optimizing TILLING and Ecotilling techniques for potato (Solanum tuberosum L). BMC Research Notes, 2(1), 141. doi:10.1186/1756-0500-2-141Dahmani-Mardas, F., Troadec, C., Boualem, A., Lévêque, S., Alsadon, A. A., Aldoss, A. A., … Bendahmane, A. (2010). Engineering Melon Plants with Improved Fruit Shelf Life Using the TILLING Approach. PLoS ONE, 5(12), e15776. doi:10.1371/journal.pone.0015776Boualem, A., Fleurier, S., Troadec, C., Audigier, P., Kumar, A. P. K., Chatterjee, M., … Bendahmane, A. (2014). Development of a Cucumis sativus TILLinG Platform for Forward and Reverse Genetics. PLoS ONE, 9(5), e97963. doi:10.1371/journal.pone.0097963Blanca, J., Cañizares, J., Roig, C., Ziarsolo, P., Nuez, F., & Picó, B. (2011). Transcriptome characterization and high throughput SSRs and SNPs discovery in Cucurbita pepo (Cucurbitaceae). BMC Genomics, 12(1). doi:10.1186/1471-2164-12-104Esteras, C., Gomez, P., Monforte, A. J., Blanca, J., Vicente-Dolera, N., Roig, C., … Pico, B. (2012). High-throughput SNP genotyping in Cucurbita pepo for map construction and quantitative trait loci mapping. BMC Genomics, 13(1), 80. doi:10.1186/1471-2164-13-80Vicente-Dólera, N., Pinillos, V., Moya, M., Del Río-Celestino, M., Pomares-Viciana, T., Román, B., & Gómez, P. (2014). An improved method to obtain novel mutants in Cucurbita pepo by pollen viability. Scientia Horticulturae, 169, 14-19. doi:10.1016/j.scienta.2014.01.045Martín, B., Ramiro, M., Martínez-Zapater, J. M., & Alonso-Blanco, C. (2009). A high-density collection of EMS-induced mutations for TILLING in Landsberg erecta genetic background of Arabidopsis. BMC Plant Biology, 9(1), 147. doi:10.1186/1471-2229-9-147Wienholds, E. (2003). Efficient Target-Selected Mutagenesis in Zebrafish. Genome Research, 13(12), 2700-2707. doi:10.1101/gr.1725103Dalmais, M., Schmidt, J., Le Signor, C., Moussy, F., Burstin, J., Savois, V., … Bendahmane, A. (2008). UTILLdb, a Pisum sativum in silico forward and reverse genetics tool. Genome Biology, 9(2), R43. doi:10.1186/gb-2008-9-2-r43Triques, K., Sturbois, B., Gallais, S., Dalmais, M., Chauvin, S., Clepet, C., … Bendahmane, A. (2007). Characterization of Arabidopsis thaliana mismatch specific endonucleases: application to mutation discovery by TILLING in pea. The Plant Journal, 51(6), 1116-1125. doi:10.1111/j.1365-313x.2007.03201.xTaylor, N. E. (2003). PARSESNP: a tool for the analysis of nucleotide polymorphisms. Nucleic Acids Research, 31(13), 3808-3811. doi:10.1093/nar/gkg574Ng, P. C. 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Molecular Genetics and Genomics, 279(3), 213-223. doi:10.1007/s00438-007-0293-2Chantreau, M., Grec, S., Gutierrez, L., Dalmais, M., Pineau, C., Demailly, H., … Hawkins, S. (2013). PT-Flax (phenotyping and TILLinG of flax): development of a flax (Linum usitatissimum L.) mutant population and TILLinG platform for forward and reverse genetics. BMC Plant Biology, 13(1), 159. doi:10.1186/1471-2229-13-159Rawat, N., Sehgal, S. K., Joshi, A., Rothe, N., Wilson, D. L., McGraw, N., … Gill, B. S. (2012). A diploid wheat TILLING resource for wheat functional genomics. BMC Plant Biology, 12(1), 205. doi:10.1186/1471-2229-12-205Minoia, S., Petrozza, A., D’Onofrio, O., Piron, F., Mosca, G., Sozio, G., … Carriero, F. (2010). A new mutant genetic resource for tomato crop improvement by TILLING technology. BMC Research Notes, 3(1). doi:10.1186/1756-0500-3-69Markiewicz, P., Kleina, L. G., Cruz, C., Ehret, S., & Miller, J. H. (1994). Genetic Studies of the lac Repressor. XIV. 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