Coercive and anisotropy fields in patterned amorphous FeSi submicrometric structures

Amorphous FexSi12x films have been prepared on Si substrates in order to fabricate submicrometric magnetic structures with soft magnetic behavior. The magnetic properties compositional dependence of the unpatterned samples has been analyzed to select the Fe content (x50.7) with the lowest coercive and anisotropy fields values. Arrays of Fe0.7Si0.3 lines have been fabricated by electron beam lithography combined with a liftoff technique, with typical dimensions of 200 nm linewidth and 1 mm line spacing. These arrays present coercive fields parallel to the line direction as small as 9 Oe.Peer reviewe

Leader Cells Define Directionality of Trunk, but Not Cranial, Neural Crest Cell Migration.

Collective cell migration is fundamental for life and a hallmark of cancer. Neural crest (NC) cells migrate collectively, but the mechanisms governing this process remain controversial. Previous analyses in Xenopus indicate that cranial NC (CNC) cells are a homogeneous population relying on cell-cell interactions for directional migration, while chick embryo analyses suggest a heterogeneous population with leader cells instructing directionality. Our data in chick and zebrafish embryos show that CNC cells do not require leader cells for migration and all cells present similar migratory capacities. In contrast, laser ablation of trunk NC (TNC) cells shows that leader cells direct movement and cell-cell contacts are required for migration. Moreover, leader and follower identities are acquired before the initiation of migration and remain fixed thereafter. Thus, two distinct mechanisms establish the directionality of CNC cells and TNC cells. This implies the existence of multiple molecular mechanisms for collective cell migration.D11I1096 Fondo de Fomento al Desarrollo Científico y TecnológicoThis is the final version of the article. It first appeared from Cell Press via httsp://doi.org/10.1016/j.celrep.2016.04.06

Direct visualization of the native structure of viroid RNAs at single-molecule resolution by atomic force microscopy

[EN] Viroids are small infectious, non-protein-coding circular RNAs that replicate independently and, in some cases, incite diseases in plants. They are classified into two families: Pospiviroidae, composed of species that have a central conserved region (CCR) and replicate in the cell nucleus, and Avsunviroidae, containing species that lack a CCR and whose multimeric replicative intermediates of either polarity generated in plastids self-cleave through hammerhead ribozymes. The compact, rod-like or branched, secondary structures of viroid RNAs have been predicted by RNA folding algorithms and further examined using different in vitro and in vivo experimental techniques. However, direct data about their native tertiary structure remain scarce. Here we have applied atomic force microscopy (AFM) to image at single-molecule resolution different variant RNAs of three representative viroids: potato spindle tuber viroid (PSTVd, family Pospiviroidae), peach latent mosaic viroid and eggplant latent viroid (PLMVd and ELVd, family Avsunviroidae). Our results provide a direct visualization of their native, three-dimensional conformations at 0 and 4 mM Mg2+ and highlight the role that some elements of tertiary structure play in their stabilization. The AFM images show that addition of 4 mM Mg2+ to the folding buffer results in a size contraction in PSTVd and ELVd, as well as in PLMVd when the kissing-loop interaction that stabilizes its 3D structure is preserved.This work was supported by the Spanish Ministerio de Economia y Competitividad (MINECO) grants BIO2016-79618-R (funded by EU under the FEDER programme) to C.B. and BFU2104-56812-P to R.F., as well as by the Comunidad de Madrid grant S2018/NMT-4349 to L.V. CIBERehd is funded by the Instituto de Salud Carlos III (ISCIII).Moreno, M.; Vázquez, L.; López Carrasco, A.; Martín-Gago, JA.; Flores Pedauye, R.; Briones, C. (2019). Direct visualization of the native structure of viroid RNAs at single-molecule resolution by atomic force microscopy. RNA Biology. 16(3):295-308. https://doi.org/10.1080/15476286.2019.1572436S295308163Diener, T. O. (2003). Discovering viroids — a personal perspective. Nature Reviews Microbiology, 1(1), 75-80. doi:10.1038/nrmicro736Flores, R., Hernández, C., Alba, A. E. M. de, Daròs, J.-A., & Serio, F. D. (2005). Viroids and Viroid-Host Interactions. Annual Review of Phytopathology, 43(1), 117-139. doi:10.1146/annurev.phyto.43.040204.140243Ding, B. (2009). The Biology of Viroid-Host Interactions. Annual Review of Phytopathology, 47(1), 105-131. doi:10.1146/annurev-phyto-080508-081927Zhang, Z., Qi, S., Tang, N., Zhang, X., Chen, S., Zhu, P., … Wu, Q. (2014). Discovery of Replicating Circular RNAs by RNA-Seq and Computational Algorithms. PLoS Pathogens, 10(12), e1004553. doi:10.1371/journal.ppat.1004553Serra, P., Messmer, A., Sanderson, D., James, D., & Flores, R. (2018). Apple hammerhead viroid-like RNA is a bona fide viroid: Autonomous replication and structural features support its inclusion as a new member in the genus Pelamoviroid. Virus Research, 249, 8-15. doi:10.1016/j.virusres.2018.03.001Hadidi, A., Barba, M., Hong, N., & Hallan, V. (2017). Apple Scar Skin Viroid. Viroids and Satellites, 217-228. doi:10.1016/b978-0-12-801498-1.00021-8Flores, R., Minoia, S., Carbonell, A., Gisel, A., Delgado, S., López-Carrasco, A., … Di Serio, F. (2015). Viroids, the simplest RNA replicons: How they manipulate their hosts for being propagated and how their hosts react for containing the infection. Virus Research, 209, 136-145. doi:10.1016/j.virusres.2015.02.027Hammann, C., & Steger, G. (2012). Viroid-specific small RNA in plant disease. 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Science, 223(4635), 450-455. doi:10.1126/science.6197756Daros, J. A., Marcos, J. F., Hernandez, C., & Flores, R. (1994). Replication of avocado sunblotch viroid: evidence for a symmetric pathway with two rolling circles and hammerhead ribozyme processing. Proceedings of the National Academy of Sciences, 91(26), 12813-12817. doi:10.1073/pnas.91.26.12813Feldstein, P. A., Hu, Y., & Owens, R. A. (1998). Precisely full length, circularizable, complementary RNA: An infectious form of potato spindle tuber viroid. Proceedings of the National Academy of Sciences, 95(11), 6560-6565. doi:10.1073/pnas.95.11.6560Daros, J.-A., & Flores, R. (2004). Arabidopsis thaliana has the enzymatic machinery for replicating representative viroid species of the family Pospiviroidae. Proceedings of the National Academy of Sciences, 101(17), 6792-6797. doi:10.1073/pnas.0401090101Flores, R., Gago-Zachert, S., Serra, P., Sanjuán, R., & Elena, S. F. (2014). Viroids: Survivors from the RNA World? Annual Review of Microbiology, 68(1), 395-414. doi:10.1146/annurev-micro-091313-103416Diener, T. O. (1989). Circular RNAs: relics of precellular evolution? Proceedings of the National Academy of Sciences, 86(23), 9370-9374. doi:10.1073/pnas.86.23.9370Ruiz-Mirazo, K., Briones, C., & de la Escosura, A. (2013). Prebiotic Systems Chemistry: New Perspectives for the Origins of Life. Chemical Reviews, 114(1), 285-366. doi:10.1021/cr2004844Flores, R., Serra, P., Minoia, S., Di Serio, F., & Navarro, B. (2012). Viroids: From Genotype to Phenotype Just Relying on RNA Sequence and Structural Motifs. Frontiers in Microbiology, 3. doi:10.3389/fmicb.2012.00217Steger, G., & Perreault, J.-P. (2016). Structure and Associated Biological Functions of Viroids. Advances in Virus Research, 141-172. doi:10.1016/bs.aivir.2015.11.002Diener, T. O. (1972). Potato spindle tuber viroid. Virology, 50(2), 606-609. doi:10.1016/0042-6822(72)90412-6Gross, H. J., Domdey, H., Lossow, C., Jank, P., Raba, M., Alberty, H., & Sänger, H. L. (1978). Nucleotide sequence and secondary structure of potato spindle tuber viroid. Nature, 273(5659), 203-208. doi:10.1038/273203a0Gast, F.-U., Kempe, D., Spieker, R. L., & Sänger, H. L. (1996). Secondary Structure Probing of Potato Spindle Tuber Viroid (PSTVd) and Sequence Comparison with Other Small Pathogenic RNA Replicons Provides Evidence for Central Non-canonical Base-pairs, Large A-rich Loops, and a Terminal Branch. Journal of Molecular Biology, 262(5), 652-670. doi:10.1006/jmbi.1996.0543Giguère, T., Raj Adkar-Purushothama, C., & Perreault, J.-P. (2014). Comprehensive Secondary Structure Elucidation of Four Genera of the Family Pospiviroidae. PLoS ONE, 9(6), e98655. doi:10.1371/journal.pone.0098655López-Carrasco, A., & Flores, R. (2016). Dissecting the secondary structure of the circular RNA of a nuclear viroid in vivo: A «naked» rod-like conformation similar but not identical to that observed in vitro. RNA Biology, 14(8), 1046-1054. doi:10.1080/15476286.2016.1223005Wang, Y., Zirbel, C. L., Leontis, N. B., & Ding, B. (2018). RNA 3-dimensional structural motifs as a critical constraint of viroid RNA evolution. PLOS Pathogens, 14(2), e1006801. doi:10.1371/journal.ppat.1006801Zhong, X., Leontis, N., Qian, S., Itaya, A., Qi, Y., Boris-Lawrie, K., & Ding, B. (2006). Tertiary Structural and Functional Analyses of a Viroid RNA Motif by Isostericity Matrix and Mutagenesis Reveal Its Essential Role in Replication. Journal of Virology, 80(17), 8566-8581. doi:10.1128/jvi.00837-06Zhong, X., Tao, X., Stombaugh, J., Leontis, N., & Ding, B. (2007). Tertiary structure and function of an RNA motif required for plant vascular entry to initiate systemic trafficking. The EMBO Journal, 26(16), 3836-3846. doi:10.1038/sj.emboj.7601812Zhong, X., Archual, A. J., Amin, A. A., & Ding, B. (2008). A Genomic Map of Viroid RNA Motifs Critical for Replication and Systemic Trafficking. The Plant Cell, 20(1), 35-47. doi:10.1105/tpc.107.056606Hernandez, C., & Flores, R. (1992). Plus and minus RNAs of peach latent mosaic viroid self-cleave in vitro via hammerhead structures. Proceedings of the National Academy of Sciences, 89(9), 3711-3715. doi:10.1073/pnas.89.9.3711Fadda, Z., Daròs, J. A., Fagoaga, C., Flores, R., & Duran-Vila, N. (2003). Eggplant Latent Viroid , the Candidate Type Species for a New Genus within the Family Avsunviroidae (Hammerhead Viroids). Journal of Virology, 77(11), 6528-6532. doi:10.1128/jvi.77.11.6528-6532.2003Navarro, B., & Flores, R. (1997). Chrysanthemum chlorotic mottle viroid: Unusual structural properties of a subgroup of self-cleaving viroids with hammerhead ribozymes. Proceedings of the National Academy of Sciences, 94(21), 11262-11267. doi:10.1073/pnas.94.21.11262Bussière, F., Ouellet, J., Côté, F., Lévesque, D., & Perreault, J. P. (2000). Mapping in Solution Shows the Peach Latent Mosaic Viroid To Possess a New Pseudoknot in a Complex, Branched Secondary Structure. Journal of Virology, 74(6), 2647-2654. doi:10.1128/jvi.74.6.2647-2654.2000GAGO, S. (2005). A kissing-loop interaction in a hammerhead viroid RNA critical for its in vitro folding and in vivo viability. RNA, 11(7), 1073-1083. doi:10.1261/rna.2230605Dube, A., Baumstark, T., Bisaillon, M., & Perreault, J.-P. (2010). The RNA strands of the plus and minus polarities of peach latent mosaic viroid fold into different structures. RNA, 16(3), 463-473. doi:10.1261/rna.1826710Sogo, J. M., Koller, T., & Diener, T. O. (1973). Potato spindle tuber viroid. Virology, 55(1), 70-80. doi:10.1016/s0042-6822(73)81009-8Goodman, T. C., Nagel, L., Rappold, W., Klotz, G., & Riesner, D. (1984). 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Prolapso genital incidencia y casuística: Hospital Naval de Guayaquil 1995 - 2000

El prolapso es motivo frecuente de consulta para en Ginecología y la mayoría de las mujeres que lo padecen sobrepasan los 50 años.Se realizó un estudio retrospectivo, descriptivo y longitudinal desde 1995 al 2000 en el hospital Naval de Guayaquil.El objetivo: Conocer los factores causales más comunes.Comprobar la importancia de la relación entre los antecedentes gineco-obstétricos y el desarrollo del prolapso genital.Identificar el tipo de tratamiento quirúrgico y las complicaciones que se presentaron al momento de la resolución en las pacientes internadas en el hospital Naval de Guayaquil (HOSNAV).Se encontraron 65 casos en el estudio de 6 años, la edad media de presentación fue 57 años 8 meses, se demostró que mientras más se acerquen a la etapa del climaterio, la incidencia de prolapso genital aumenta en forma proporcional. El factor causal que se relaciona al desarrollo de prolapsos es la multiparidad y los partos distócicos

DNA-based population density estimation of black bear at northern Mexico: A preliminary study

The analysis of deoxyribonucleic acid (DNA) microsatellites from hair samples obtained by the non-invasive method of traps was used to estimate the population density of black bears (Ursus americanus eremicus) in a mountain located at the county of Lampazos, Nuevo Leon, Mexico. The genotyping of bears was performed by multiplex polymerase chain reaction (PCR) using an average of two hairs for each animal. Samples were obtained with barbed wire placed at the traps, which contained food as bait. Multiplex PCR was performed with the GenomiPhiTM, G.E. kit and genotyping with an automated DNA sequencing machine (ABI 310 System). Allelic frequency, heterozygosis and exclusion probability of seven DNA microsatellites were calculated and analyzed with computer programs to determine the population density. Three of the microsatellites had a heterozygosis higher than 0.7 and the population density was calculated in at least 1 bear/km2.Keywords: Black bear, Ursus americanus, population size, DNA microsatellite, MexicoAfrican Journal of Biotechnology Vol. 12(2), pp. 103-10

Strategies and options for increasing and sustaining fisheries and aquaculture production to benefit poorer households in Asia [PDF in letter standard]

The last three decades have wi tnessed dramatic changes in the structure of supply and demand for fish, especially in Asia. This WorldFish research study sponsored by the Asian Development Bank focussed on nine developing countries û Bangladesh, China, India, Indonesia, Malaysia, the Philippines, Sri Lanka, Thailand, and Vietnam, all active players in the transformation of global fish supply and demand. The study, broken into five components and reported here, considered: 1) the profile of key aquaculture technologies and fishing practices; 2) analysis of policies, institutions and support services; 3) socioeconomic profile of major stakeholders in the fisheries sector; 4) projections of fish demand and supply in the nine Asian countries; and 5) formulation of national action plans based on the findings and recommendations of the study.Research, Fisheries, Economic analysis, Aquaculture, Fish consumption, Trade, Policies, Socioeconomic aspects, Technology, Fishery products, Asia, China, People's Rep., Bangladesh, India, Indonesia, Malaysia, Philippines, Malaysia, Sri Lanka, Thailand, Vietnam,