2,104 research outputs found

    Making sense of Wnt signaling—linking hair cell regeneration to development

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    Wnt signaling is a highly conserved pathway crucial for development and homeostasis of multicellular organisms. Secreted Wnt ligands bind Frizzled receptors to regulate diverse processes such as axis patterning, cell division, and cell fate specification. They also serve to govern self-renewal of somatic stem cells in several adult tissues. The complexity of the pathway can be attributed to the myriad of Wnt and Frizzled combinations as well as its diverse context-dependent functions. In the developing mouse inner ear, Wnt signaling plays diverse roles, including specification of the otic placode and patterning of the otic vesicle. At later stages, its activity governs sensory hair cell specification, cell cycle regulation, and hair cell orientation. In regenerating sensory organs from non-mammalian species, Wnt signaling can also regulate the extent of proliferative hair cell regeneration. This review describes the current knowledge of the roles of Wnt signaling and Wnt-responsive cells in hair cell development and regeneration. We also discuss possible future directions and the potential application and limitation of Wnt signaling in augmenting hair cell regeneration

    Object kinetic Monte Carlo study of the effect of grain boundaries in martensitic Fe-Cr-C alloys

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    Fe-Cr-C alloys with chromium concentrations in the range from similar to 2 to 12 wt.% form ferritic-martensitic structures by rapid cooling from the austenite state already in the presence of relatively low carbon concentrations. In this process it is possible to obtain different ratios of ferrite and martensite, as well as formation of carbides, by varying the thermal treatment. The presence of ferrite or martensite might have an influence on the nanostructural evolution under irradiation of these alloys. Here, considering a tempered martensite reference alloy with 9% Cr, we make use of an already validated object kinetic Monte Carlo (OKMC) model in order to study the possible effect of the formation of martensite laths on the material nanostructural evolution under neutron irradiation, assuming that the relevant boundaries act as sinks for radiation defects. The results show that the reduction of the grain size (including in this definition the average size of prior austenite grains, packets, blocks, and laths) does not play any relevant role until sizes of the order of similar to 0.5 mu m are reached: for smaller grains, the number of defects being absorbed by the boundaries becomes dominant. However, this threshold is lower than the experimentally observed martensite lath dimensions, thereby suggesting that what makes the difference in martensitic Fe-Cr-C alloys with respect to ferrite, concerning events and mechanisms taking place during irradiation, are not the lath boundaries as sinks. Differences between the nanostructural evolution under neutron irradiation in ferrite and martensite should therefore be ascribed to other factors. (C) 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei

    Suitability of Paper-Based Substrates for Printed Electronics

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    Flexible plastic substrates are widely used in printed electronics; however, they cause major climate impacts and pose sustainability challenges. In recent years, paper-based electronics has been studied to increase the recyclability and sustainability of printed electronics. The aim of this paper is to analyze the printability and performance of metal conductor layers on different paper-based substrates using both flexography and screen printing and to compare the achieved performance with that of plastic foils. In addition, the re-pulpability potential of the used paper-based substrates is evaluated. As compared to the common polyethylene terephthalate (PET) substrate, the layer conductivity on paper-based substrates was found to be improved with both the printing methods without having a large influence on the detail rendering. This means that a certain surface roughness and porosity is needed for the improved ink transfer and optimum ink behavior on the surface of the substrate. In the case of uncoated paper-based substrates, the conductivity and print quality decreased by preventing the formation of the proper and intimate ink-substrate contact during the ink transfer. Finally, the re-pulpability trials together with layer quality analysis detected very good, coated substrate candidates for paper-based printed electronics competing with or even outperforming the print quality on the reference PET foil

    International energy agency ocean energy systems task 10 wave energy converter modeling verification and validation

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    This is the first joint reference paper for the Ocean Energy Systems (OES) Task 10 Wave Energy Converter modeling verification and validation group. The group is established under the OES Energy Technology Network program under the International Energy Agency. OES was founded in 2001 and Task 10 was proposed by Bob Thresher (National Renewable Energy Laboratory) in 2015 and approved by the OES Executive Committee EXCO in 2016. The kickoff workshop took place in September 2016, wherein the initial baseline task was defined. Experience from similar offshore wind validation/verification projects (OC3-OC5 conducted within the International Energy Agency Wind Task 30) [1], [2] showed that a simple test case would help the initial cooperation to present results in a comparable way. A heaving sphere was chosen as the first test case. The team of project participants simulated different numerical experiments, such as heave decay tests and regular and irregular wave cases. The simulation results are presented and discussed in this paper.IEA-OES Task 1

    PENGARUH DOSIS PUPUK GUANO DAN BEBERAPA JENIS MULSA TERHADAP PERTUMBUHAN DANM HASIL TANAMAN KENTANG (Solanum tuberosum L.)

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    Kentang adalah salah satu jenis komoditi hortikultura yang penting karena kaya akan karbohidrat dan dapat digunakan sebagai pengganti bahan makanan pokok. Di indonesia kentang sudah dijadikan bahan pangan alternatif terutama dalam pemenuhan gizi dan pangan masyarakat indonesia di samping beras. Penelitian ini telah dilakukan di Jorong Galagah, Kanagarian Alahan Panjang, Kecamatan Lembah Gumanti, Kabupaten Solok, Sumatera Barat dari bulan Maret sampai Juni 2018. Tujuan penelitian ini adalah mendapatkan interaksi terbaik antara pemberian pupuk guano dan penggunaan beberapa jenis mulsa terhadap pertumbuhan dan hasil tanaman kentang, mendapatkan pengaruh dosis pupuk guano terbaik terhadap pertumbuhan dan hasil tanaman kentang, mendapatkan jenis mulsa yang terbaik terhadap pertumbuhan dan hasil tanaman kentang. Rancangan yang digunakan yaitu Rancangan Acak Lengkap (RAL) pola faktorial dengan 3 ulangan. Faktor pertama adalah pupuk guano (0, 3, 6 dan 9 ton/ha) dan faktor kedua adalah mulsa plastik hitam perak dan mulsa plastik hitam. Data dianalisis secara statistik dengan uji F pada taraf nyata 5%, apabila F hitung lebih besar dari F tabel maka dilanjutkan dengan Uji Duncan’s New Multiple Range Tes (DNMRT) pada taraf 5%. Hasil penelitian menunjukkan tidak ada pengaruh antara pemberian pupuk guano dan penggunaan beberapa jenis mulsa terhadap tinggi tanaman, jumlah daun, dan diameter umbi terkecil. Dosis pupuk guano 9 ton/ha memberikan pengaruh terbaik terhadap jumlah umbi, jumlah cabang, dan diameter umbi terbesar. Jenis mulsa plastik hitam memberikan pengaruh terbaik terhadap jumlah umbi, diameter umbi terbesar, bobot umbi pertanaman, bobot umbi perpetak, dan bobot umbi per hektar. Kata kunci : kentang Cingkariang, pupuk guano, muls

    Thermal stability of a weakly magnetized rotating plasma

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    The thermal stability of a weakly magnetized, rotating, stratified, optically thin plasma is studied by means of linear-perturbation analysis. We derive dispersion relations and criteria for stability against axisymmetric perturbations that generalize previous results on either non-rotating or unmagnetized fluids. The implications for the hot atmospheres of galaxies and galaxy clusters are discussed.Comment: 16 pages, 3 figures, MNRAS accepted. New figures and corrected equations with respect to previous version. Results unchange

    Genetic study reveals local differentiation persisting in the face of high connectivity and a genomic inversion likely linked with sexual antagonism in a common marine fish

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    Sustainable harvest of wild populations requires knowledge of the underlying population structure. The focus of this study is on goldsinny wrasse (Ctenolabrus rupestris), a small marine fish inhabiting coastal waters of the north-eastern Atlantic. This species is caught in large numbers to serve as cleaner fish in salmonid aquaculture. We genotyped 2073 goldsinny wrasse from 43 sites along the Scandinavian coastline with 143 SNPs. Seven of the SNPs were linked and likely reside within a large genomic inversion dominated by one haplotype. The heterokaryotype of the putative inversion displayed sex-specific growth patterns, potentially resolving sexual antagonism for this trait. The unlinked 134 SNPs showed modest isolation-by-distance with samples from the northernmost locations showing highest divergence, whereas sites farther south were much more interconnected. Genetic divergence (FST) was highly variable among sites within regions, suggesting a varying degree of connectivity and local divergence. We conclude that despite a high degree of gene-flow mediated through pelagic dispersal in early life stages, regional and some local population structure remains due to limited adult movement in addition to other unidentified factors. Consequently, the species might be more vulnerable to local disturbances than previously anticipated.publishedVersio

    A Case of Acute Hepatitis with Mycoplasma pneumoniae Infection and Transient Depression of Multiple Coagulation Factors

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    We report a case of acute severe hepatitis with Mycoplasma pneumoniae (M. pneumoniae) infection and transient depression of multiple coagulation factors. A 5-year-old boy, previously healthy, was admitted with pneumonia. M. pneumoniae infection was confirmed by serology testing. Liver enzymes were elevated on admission without any past medical history. After treatment with azithromycin for 3 days, pneumonia improved, but the hepatitis was acutely aggravated. Partial thromboplastin time (PTT) was prolonged and depression of multiple coagulation factors developed. Liver biopsy revealed features consistent with acute hepatitis. A week later, liver enzymes were nearly normalized spontaneously. Normalization of prolonged PTT and coagulation factors were also observed several months later. This may be the first case of transient depression of multiple coagulation factors associated with M. pneumoniae infection
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