Reconocimiento de la sigatoka negra (Mycosphaerella fijiensis) del plátano y banano en el municipio de Cocorná.

En 1992 en una vereda ubicada entre Cocorná y San Luis se encontraron los síntomas característicos de la sigatoka negra, los cuales fueron confirmados mediante pruebas de laboratorio. Este hecho creó la necesidad de efectuar un reconocimiento con el propósito de constatar su presencia y conocer la distribución geográfica en el municipio de Cocorná, principal productor de plátano en el oriente antioqueño. Se concluyó que la enfermedad no estaba muy difundida en la región, pero debido a condiciones ambientales y de manejo del cultivo favorables para el desarrollo del patógeno es muy posible que tenga una rápida difusión si no se toman las medidas necesariasBanano- Musa acuminata - Musa paradisiacaCoco-Cocos nuciferaPlátano-Musa sapientu

Design, manufacturing and set-up tests of a wave energy converter prototype in the context of the European Project LIFE-Demowave

LifeDemoWave Project is a real case of development of a R&D project, from the initial idea to the final construction and installation of a prototype for testing in operational environment. This project was born from an idea of the main researcher of the CIMA Group that finally led to two patents of two wave generation systems. Based on these patents, CIMA sought different ways for funding with the aim of developing prototypes with a high TRL and being able to test the operating principle of the patented systems. Finally, funding was obtained through the Life Program of the European Union and in collaboration with five other partners. The main objective of the LifeDemoWave project (http://www. life-demowave.eu/en/) is the demonstration of the feasibility of the use of wave power for electric generation in order to reduce greenhouse gases' emissions. For demonstration purposes, prototypes of wave power generation, reproducible and scalable at high level, are installed in the Galician coast. LifeDemoWave project considers, as well as its design and implementation, the environmental impact in the installation areas and its effect on biodiversity.Peer Reviewe

Glucocerebrosidase mutations and synucleinopathies. Potential role of sterylglucosides and relevance of studying both GBA1 and GBA2 genes.

Gaucher's disease (GD) is the most prevalent lysosomal storage disorder. GD is caused by homozygous mutations of the GBA1 gene, which codes for beta-glucocerebrosidase (GCase). Although GD primarily affects peripheral tissues, the presence of neurological symptoms has been reported in several GD subtypes. GBA1 mutations have recently deserved increased attention upon the demonstration that both homo- and heterozygous GBA1 mutations represent the most important genetic risk factor for the appearance of synucleinopathies like Parkinson's disease (PD) and dementia with Lewy bodies (LBD). Although reduced GCase activity leads to alpha-synuclein aggregation, the mechanisms sustaining a role for GCase in alpha-synuclein homeostasis still remain largely unknown. Furthermore, the role to be played by impairment in the physiological function of endoplasmic reticulum, mitochondria and other subcellular membranous components is currently under investigation. Here we focus on the impact of GCase loss-of-function that impact on the levels of sterylglucosides, molecules that are known to trigger a PD-related synucleinopathy upon administration in rats. Moreover, the concurrence of another gene also coding for an enzyme with GCase activity (GBA2 gene) should also be taken into consideration, bearing in mind that in addition to a hydrolytic function, both GCases also share transglycosylation as a second catalytic activity. Accordingly, sterylglycoside levels should also be considered to further assess their impact on the neurodegenerative process. In this regard¿and besides GBA1 genotyping¿we suggest that screening for GBA2 mutations should be considered, together with analytical measurements of cholesterol glycosides in body fluids, as biomarkers for both PD risk and disease progression

Cuestionario para la selección de conceptos fundamentales: análisis de validez y confiabilidad

La conceptualización tiene una importancia capital en el aprendizaje, cuya medición se puede representar como una modificación de las estructuras cognitivas del individuo. Para su análisis resulta esencial establecer los conceptos objetivos y comprobar la estabilidad o modificación de sus relaciones. Este estudio describe la creación de un instrumento de recogida de información, concretamente un cuestionario, validado por expertos en la materia, donde se permite a los alumnos introducir los conceptos más importantes sobre una temática concreta, para su posterior análisis con técnicas de representación de la estructura cognitiva. Es un instrumento de recolección de información abierto, en cuanto a que se ajusta a las necesidades de los investigadores, y, a su vez, orientado, ya que permite establecer las líneas fundamentales que relacionan los conceptos sobre los que se cuestiona

Intragenic recombination between pseudogenes as a source of new disease specificity at a simple resistance locus

BACKGROUND: Pooling of multi-site MRI data is often necessary when a large cohort is desired. However, different scanning platforms can introduce systematic differences which confound true effects of interest. One may reduce multi-site bias by calibrating pivotal scanning parameters, or include them as covariates to improve the data integrity. NEW METHOD: In the present study we use a source-based morphometry (SBM) model to explore scanning effects in multi-site sMRI studies and develop a data-driven correction. Specifically, independent components are extracted from the data and investigated for associations with scanning parameters to assess the influence. The identified scanning-related components can be eliminated from the original data for correction. RESULTS: A small set of SBM components captured most of the variance associated with the scanning differences. In a dataset of 1460 healthy subjects, pronounced and independent scanning effects were observed in brainstem and thalamus, associated with magnetic field strength-inversion time and RF-receiving coil. A second study with 110 schizophrenia patients and 124 healthy controls demonstrated that scanning effects can be effectively corrected with the SBM approach. COMPARISON WITH EXISTING METHOD(S): Both SBM and GLM correction appeared to effectively eliminate the scanning effects. Meanwhile, the SBM-corrected data yielded a more significant patient versus control group difference and less questionable findings. CONCLUSIONS: It is important to calibrate scanning settings and completely examine individual parameters for the control of confounding effects in multi-site sMRI studies. Both GLM and SBM correction can reduce scanning effects, though SBM's data-driven nature provides additional flexibility and is better able to handle collinear effects

Comparison of Three CIDR Based Fixed-time AI Protocols for Beef Heifers

Several effective fixed-time AI (FTAI) protocols have been developed to facilitate AI while eliminating the need for estrus detection. Among these are the 5-d CO-Synch+CIDR (5d), PG 6-d CIDR (PG-CIDR), and 14-d CIDR-PG (CIDR-PG) protocols. While each of these protocols varies in duration and approach to synchronizing estrus and ovulation, each has been reported as an effective method to facilitate FTAI in beef heifers. Therefore, the objective of this study was to compare FTAI pregnancy rates in beef heifers synchronized with these three CIDR based protocols. Virgin beef heifers (n = 801) at four locations were synchronized with one of three protocols: 1) (5-day CO-Synch + CIDR) an injection of GnRH (100 μg; i.m.) and insertion of a CIDR on d -5, PG (25 mg; i.m.) and CIDR removal on d 0 with a second injection of PG (\u3e4 h after CIDR removal) on d 0 and FTAI at 72 h after CIDR removal, 2) (PG 6-day CIDR) PG (25 mg; i.m.) on d -9, GnRH (100 μg; i.m.) and insertion of a CIDR on d -6, PG and CIDR removal on d 0, and FTAI at 66 h after CIDR removal, or 3) (14-day CIDR-PG) a 14-day CIDR insert from d -30 to -16, PG (25 mg; i.m.) on d 0, and FTAI at 66 h after PG. All heifers received an injection of GnRH (100 μg; i.m.) concurrent with FTAI. Timing of treatment initiation was offset to allow all heifers to receive FTAI concomitantly and at random. Pregnancy success was determined between 35 and 40 d after FTAI by transrectal ultrasonography. Blood samples were collected approximately 12 d before the beginning of each protocol and at the initiation of each protocol to determine estrous cycling status (77%). Data were analyzed using the GLIMMIX procedures of SAS. Fixed-time AI pregnancy success did not differ between treatments (P = 0.13; 62.5%, 56.9%, and 53.3%, for 5-day CO-Synch + CIDR, PG 6-day CIDR, and 14-day CIDR-PG; respectively) or location (P = 0.16; 51.5%, 62.7%, 56.1%, and 58.6% for location 1, 2, 3, and 4; respectively). However, heifers that had reached puberty by initiation of synchronization had greater (P \u3c 0.01) pregnancy success compared to heifers that were prepubertal (60.7% and 47.3%; respectively). In summary, all three protocols had similar FTAI pregnancy success, and puberty status had the greatest impact on pregnancy success

Dietary supplementation with vitamins C and E prevents downregulation of endothelial NOS expression in hypercholesterolemia in vivo and in vitro

Impaired endothelium-dependent vasodilation has been associated with decreased NO bioavailability in hypercholesterolemia. This study aimed to determine whether antioxidant vitamins C and E could improve hypercholesterolemia-derived endothelial dysfunction in the porcine model, and whether observed in vivo results could be reproduced in vitro by incubation of coronary endothelial cells (EC) in the presence of native low-density lipoproteins (LDL). Adult mini-pigs were fed standard (C), cholesterol rich (HC) or cholesterol rich diet supplemented with vitamins C and E (HCV). Endothelium-dependent blood flow increase in response to acetylcholine was determined. Endothelial nitric oxide synthase (eNOS) expression was measured in arterial samples and in EC incubated with LDL isolated from porcine plasma. Vasomotor response to acetylcholine in HC was significantly lower (P<0.05) than control and HCV. There was a significant (P<0.05) decrease in eNOS immunoreactivity in HC, compared with HCV and control. Native LDL from HC, but not from HCV, induced a significant decrease in eNOS expression. Vitamins C and E treatment improved the endothelium-dependent vasomotor capacity and prevented decreased expression of eNOS in hypercholesterolemic pigs. A similar effect could be demonstrated in vitro, by incubation of EC with native LDL, suggesting that the effect of physiologically-modified LDL on eNOS could have a role in recovering vascular function

DNA synthesis determines the binding mode of the human mitochondrial single-stranded DNA-binding protein

[EN] Single-stranded DNA-binding proteins (SSBs) play a key role in genome maintenance, binding and organizing single-stranded DNA (ssDNA) intermediates. Multimeric SSBs, such as the human mitochondrial SSB (HmtSSB), present multiple sites to interact with ssDNA, which has been shown in vitro to enable them to bind a variable number of single-stranded nucleotides depending on the salt and protein concentration. It has long been suggested that different binding modes might be used selectively for different functions. To study this possibility, we used optical tweezers to determine and compare the structure and energetics of long, individual HmtSSB¿DNA complexes assembled on preformed ssDNA and on ssDNA generated gradually during `in situ¿ DNA synthesis. We show that HmtSSB binds to preformed ss-DNA in two major modes, depending on salt and protein concentration. However, when protein binding was coupled to strand-displacement DNA synthesis, only one of the two binding modes was observed under all experimental conditions. Our results reveal a key role for the gradual generation of ssDNA in modulating the binding mode of a multimeric SSB protein and consequently, in generating the appropriate nucleoprotein structure for DNA synthetic reactions required for genome maintenance.We are grateful to Prof. M. Salas laboratory (CBMSO-CSIC) for generously providing the Phi29 DNA polymerase and to Juan P. García Villaluenga (UCM) for useful discussions. Spanish Ministry of Economy and Competitiveness [MAT2015-71806-R to J.R.A-G, FIS2010-17440, FIS2015-67765-R to F.J.C., BFU2012-31825, BFU2015-63714-R to B.I.]; Spanish Ministry of Education, Culture and Sport [FPU13/02934 to J.J., FPU13/02826 to E.B-H.]; National Institutes of Health [GM45925 to L.S.K.]; University of Tampere (to G.L.C.); Programa de Financiacion Universidad Complutense de Madrid-Santander Universidades [CT45/15-CT46/15 to F.C.]. Funding for open access charge: Spanish Ministry of Economy and Competitiveness [BFU2015-63714-R].Morin, J.; Cerrón, F.; Jarillo, J.; Beltran-Heredia, E.; Ciesielski, G.; Arias-Gonzalez, JR.; Kaguni, L.... (2017). DNA synthesis determines the binding mode of the human mitochondrial single-stranded DNA-binding protein. Nucleic Acids Research. 45(12):7237-7248. https://doi.org/10.1093/nar/gkx395S723772484512Shereda, R. D., Kozlov, A. G., Lohman, T. M., Cox, M. M., & Keck, J. L. (2008). SSB as an Organizer/Mobilizer of Genome Maintenance Complexes. Critical Reviews in Biochemistry and Molecular Biology, 43(5), 289-318. doi:10.1080/10409230802341296Flynn, R. L., & Zou, L. (2010). Oligonucleotide/oligosaccharide-binding fold proteins: a growing family of genome guardians. Critical Reviews in Biochemistry and Molecular Biology, 45(4), 266-275. doi:10.3109/10409238.2010.488216Murzin, A. G. (1993). OB(oligonucleotide/oligosaccharide binding)-fold: common structural and functional solution for non-homologous sequences. The EMBO Journal, 12(3), 861-867. doi:10.1002/j.1460-2075.1993.tb05726.xKozlov, A. G., Weiland, E., Mittal, A., Waldman, V., Antony, E., Fazio, N., … Lohman, T. M. (2015). Intrinsically Disordered C-Terminal Tails of E. coli Single-Stranded DNA Binding Protein Regulate Cooperative Binding to Single-Stranded DNA. Journal of Molecular Biology, 427(4), 763-774. doi:10.1016/j.jmb.2014.12.020Kuznetsov, S. V., Kozlov, A. G., Lohman, T. M., & Ansari, A. (2006). Microsecond Dynamics of Protein–DNA Interactions: Direct Observation of the Wrapping/Unwrapping Kinetics of Single-stranded DNA around the E.coli SSB Tetramer. Journal of Molecular Biology, 359(1), 55-65. doi:10.1016/j.jmb.2006.02.070Lohman, T. M., & Ferrari, M. E. (1994). Escherichia Coli Single-Stranded DNA-Binding Protein: Multiple DNA-Binding Modes and Cooperativities. Annual Review of Biochemistry, 63(1), 527-570. doi:10.1146/annurev.bi.63.070194.002523Maier, D., Farr, C. L., Poeck, B., Alahari, A., Vogel, M., Fischer, S., … Schneuwly, S. (2001). Mitochondrial Single-stranded DNA-binding Protein Is Required for Mitochondrial DNA Replication and Development in Drosophila melanogaster. Molecular Biology of the Cell, 12(4), 821-830. doi:10.1091/mbc.12.4.821Ruhanen, H., Borrie, S., Szabadkai, G., Tyynismaa, H., Jones, A. W. E., Kang, D., … Yasukawa, T. (2010). Mitochondrial single-stranded DNA binding protein is required for maintenance of mitochondrial DNA and 7S DNA but is not required for mitochondrial nucleoid organisation. Biochimica et Biophysica Acta (BBA) - Molecular Cell Research, 1803(8), 931-939. doi:10.1016/j.bbamcr.2010.04.008Farr, C. L., Matsushima, Y., Lagina, A. T., Luo, N., & Kaguni, L. S. (2004). Physiological and Biochemical Defects in Functional Interactions of Mitochondrial DNA Polymerase and DNA-binding Mutants of Single-stranded DNA-binding Protein. Journal of Biological Chemistry, 279(17), 17047-17053. doi:10.1074/jbc.m400283200Van Tuyle, G. C., & Pavco, P. A. (1985). The rat liver mitochondrial DNA-protein complex: displaced single strands of replicative intermediates are protein coated. The Journal of Cell Biology, 100(1), 251-257. doi:10.1083/jcb.100.1.251Clayton, D. A. (1982). Replication of animal mitochondrial DNA. Cell, 28(4), 693-705. doi:10.1016/0092-8674(82)90049-6Farr, C. L., Wang, Y., & Kaguni, L. S. (1999). Functional Interactions of Mitochondrial DNA Polymerase and Single-stranded DNA-binding Protein. Journal of Biological Chemistry, 274(21), 14779-14785. doi:10.1074/jbc.274.21.14779Korhonen, J. A., Gaspari, M., & Falkenberg, M. (2003). TWINKLE Has 5′ → 3′ DNA Helicase Activity and Is Specifically Stimulated by Mitochondrial Single-stranded DNA-binding Protein. Journal of Biological Chemistry, 278(49), 48627-48632. doi:10.1074/jbc.m306981200Miralles Fusté, J., Shi, Y., Wanrooij, S., Zhu, X., Jemt, E., Persson, Ö., … Falkenberg, M. (2014). In Vivo Occupancy of Mitochondrial Single-Stranded DNA Binding Protein Supports the Strand Displacement Mode of DNA Replication. PLoS Genetics, 10(12), e1004832. doi:10.1371/journal.pgen.1004832Oliveira, M. T., & Kaguni, L. S. (2011). Reduced Stimulation of Recombinant DNA Polymerase γ and Mitochondrial DNA (mtDNA) Helicase by Variants of Mitochondrial Single-stranded DNA-binding Protein (mtSSB) Correlates with Defects in mtDNA Replication in Animal Cells. Journal of Biological Chemistry, 286(47), 40649-40658. doi:10.1074/jbc.m111.289983Williams, A. J., & Kaguni, L. S. (1995). Stimulation ofDrosophilaMitochondrial DNA Polymerase by Single-stranded DNA-binding Protein. Journal of Biological Chemistry, 270(2), 860-865. doi:10.1074/jbc.270.2.860Bogenhagen, D. F., Wang, Y., Shen, E. L., & Kobayashi, R. (2003). Protein Components of Mitochondrial DNA Nucleoids in Higher Eukaryotes. Molecular & Cellular Proteomics, 2(11), 1205-1216. doi:10.1074/mcp.m300035-mcp200BARAT-GUERIDE, M., DUFRESNE, C., & RICKWOOD, D. (1989). Effect of DNA conformation on the transcription of mitochondrial DNA. European Journal of Biochemistry, 183(2), 297-302. doi:10.1111/j.1432-1033.1989.tb14928.xYang, C., Curth, U., Urbanke, C., & Kang, C. (1997). Crystal structure of human mitochondrial single-stranded DNA binding protein at 2.4 Å resolution. Nature Structural Biology, 4(2), 153-157. doi:10.1038/nsb0297-153Raghunathan, S., Ricard, C. S., Lohman, T. M., & Waksman, G. (1997). Crystal structure of the homo-tetrameric DNA binding domain of Escherichia coli single-stranded DNA-binding protein determined by multiwavelength x-ray diffraction on the selenomethionyl protein at 2.9-A resolution. Proceedings of the National Academy of Sciences, 94(13), 6652-6657. doi:10.1073/pnas.94.13.6652CURTH, U., URBANKE, C., GREIPEL, J., GERBERDING, H., TIRANTI, V., & ZEVIANI, M. (1994). Single-stranded-DNA-binding proteins from human mitochondria and Escherichia coli have analogous physicochemical properties. European Journal of Biochemistry, 221(1), 435-443. doi:10.1111/j.1432-1033.1994.tb18756.xOverman, L. B., & Lohman, T. M. (1994). Linkage of pH, Anion and Cation Effects in Protein-Nucleic Acid Equilibria. Journal of Molecular Biology, 236(1), 165-178. doi:10.1006/jmbi.1994.1126Bhattacharyya, B., George, N. P., Thurmes, T. M., Zhou, R., Jani, N., Wessel, S. R., … Keck, J. L. (2013). Structural mechanisms of PriA-mediated DNA replication restart. Proceedings of the National Academy of Sciences, 111(4), 1373-1378. doi:10.1073/pnas.1318001111Carlini, L. E., Porter, R. D., Curth, U., & Urbanke, C. (1993). Viability and preliminary in vivo characterization of site directed mutants of Escherichia coli single-stranded DNA-binding protein. Molecular Microbiology, 10(5), 1067-1075. doi:10.1111/j.1365-2958.1993.tb00977.xGriffith, J. D., Harris, L. D., & Register, J. (1984). Visualization of SSB-ssDNA Complexes Active in the Assembly of Stable RecA-DNA Filaments. Cold Spring Harbor Symposia on Quantitative Biology, 49(0), 553-559. doi:10.1101/sqb.1984.049.01.062Morrical, S. W., & Cox, M. M. (1990). Stabilization of recA protein-ssDNA complexes by the single-stranded DNA binding protein of Escherichia coli. Biochemistry, 29(3), 837-843. doi:10.1021/bi00455a034Muniyappa, K., Williams, K., Chase, J. W., & Radding, C. M. (1990). Active nucleoprotein filaments of single-stranded binding protein and recA protein on single-stranded DNA have a regular repeating structure. Nucleic Acids Research, 18(13), 3967-3973. doi:10.1093/nar/18.13.3967Wessel, S. R., Marceau, A. H., Massoni, S. C., Zhou, R., Ha, T., Sandler, S. J., & Keck, J. L. (2013). PriC-mediated DNA Replication Restart Requires PriC Complex Formation with the Single-stranded DNA-binding Protein. Journal of Biological Chemistry, 288(24), 17569-17578. doi:10.1074/jbc.m113.478156Bell, J. C., Liu, B., & Kowalczykowski, S. C. (2015). Imaging and energetics of single SSB-ssDNA molecules reveal intramolecular condensation and insight into RecOR function. eLife, 4. doi:10.7554/elife.08646Suksombat, S., Khafizov, R., Kozlov, A. G., Lohman, T. M., & Chemla, Y. R. (2015). Structural dynamics of E. coli single-stranded DNA binding protein reveal DNA wrapping and unwrapping pathways. eLife, 4. doi:10.7554/elife.08193Zhou, R., Kozlov, A. G., Roy, R., Zhang, J., Korolev, S., Lohman, T. M., & Ha, T. (2011). SSB Functions as a Sliding Platform that Migrates on DNA via Reptation. Cell, 146(2), 222-232. doi:10.1016/j.cell.2011.06.036Pant, K., Karpel, R. L., Rouzina, I., & Williams, M. C. (2004). Mechanical Measurement of Single-molecule Binding Rates: Kinetics of DNA Helix-destabilization by T4 Gene 32 Protein. Journal of Molecular Biology, 336(4), 851-870. doi:10.1016/j.jmb.2003.12.025Pant, K., Karpel, R. L., Rouzina, I., & Williams, M. C. (2005). Salt Dependent Binding of T4 Gene 32 Protein to Single and Double-stranded DNA: Single Molecule Force Spectroscopy Measurements. Journal of Molecular Biology, 349(2), 317-330. doi:10.1016/j.jmb.2005.03.065Robberson, D. L., & Clayton, D. A. (1972). Replication of Mitochondrial DNA in Mouse L Cells and Their Thymidine Kinase- Derivatives: Displacement Replication on a Covalently-Closed Circular Template. Proceedings of the National Academy of Sciences, 69(12), 3810-3814. doi:10.1073/pnas.69.12.3810Ciesielski, G. L., Bermek, O., Rosado-Ruiz, F. A., Hovde, S. L., Neitzke, O. J., Griffith, J. D., & Kaguni, L. S. (2015). Mitochondrial Single-stranded DNA-binding Proteins Stimulate the Activity of DNA Polymerase γ by Organization of the Template DNA. Journal of Biological Chemistry, 290(48), 28697-28707. doi:10.1074/jbc.m115.673707Lázaro, J. M., Blanco, L., & Salas, M. (1995). [5] Purification of bacteriophage φ29 DNA polymerase. DNA Replication, 42-49. doi:10.1016/0076-6879(95)62007-9Ibarra, B., Chemla, Y. R., Plyasunov, S., Smith, S. B., Lázaro, J. M., Salas, M., & Bustamante, C. (2009). Proofreading dynamics of a processive DNA polymerase. The EMBO Journal, 28(18), 2794-2802. doi:10.1038/emboj.2009.219Morin, J. A., Cao, F. J., Lazaro, J. M., Arias-Gonzalez, J. R., Valpuesta, J. M., Carrascosa, J. L., … Ibarra, B. (2012). Active DNA unwinding dynamics during processive DNA replication. Proceedings of the National Academy of Sciences, 109(21), 8115-8120. doi:10.1073/pnas.1204759109Smith, S. B., Cui, Y., & Bustamante, C. (2003). [7] Optical-trap force transducer that operates by direct measurement of light momentum. Biophotonics, Part B, 134-162. doi:10.1016/s0076-6879(03)61009-8Bosco, A., Camunas-Soler, J., & Ritort, F. (2013). Elastic properties and secondary structure formation of single-stranded DNA at monovalent and divalent salt conditions. Nucleic Acids Research, 42(3), 2064-2074. doi:10.1093/nar/gkt1089Smith, S., Finzi, L., & Bustamante, C. (1992). Direct mechanical measurements of the elasticity of single DNA molecules by using magnetic beads. Science, 258(5085), 1122-1126. doi:10.1126/science.1439819Longley, M. J., Smith, L. A., & Copeland, W. C. (2009). Preparation of Human Mitochondrial Single-Stranded DNA-Binding Protein. Mitochondrial DNA, 73-85. doi:10.1007/978-1-59745-521-3_5Li, K., & Williams, R. S. (1997). Tetramerization and Single-stranded DNA Binding Properties of Native and Mutated Forms of Murine Mitochondrial Single-stranded DNA-binding Proteins. Journal of Biological Chemistry, 272(13), 8686-8694. doi:10.1074/jbc.272.13.8686Jarillo, J., Morín, J. A., Beltrán-Heredia, E., Villaluenga, J. P. G., Ibarra, B., & Cao, F. J. (2017). Mechanics, thermodynamics, and kinetics of ligand binding to biopolymers. PLOS ONE, 12(4), e0174830. doi:10.1371/journal.pone.0174830Bujalowski, W., & Lohman, T. M. (1986). Escherichia coli single-strand binding protein forms multiple, distinct complexes with single-stranded DNA. Biochemistry, 25(24), 7799-7802. doi:10.1021/bi00372a003Thömmes, P., Farr, C. L., Marton, R. F., Kaguni, L. S., & Cotterill, S. (1995). Mitochondrial Single-stranded DNA-binding Protein fromDrosophilaEmbryos. Journal of Biological Chemistry, 270(36), 21137-21143. doi:10.1074/jbc.270.36.21137Rodriguez, I., Lazaro, J. M., Blanco, L., Kamtekar, S., Berman, A. J., Wang, J., … de Vega, M. (2005). A specific subdomain in  29 DNA polymerase confers both processivity and strand-displacement capacity. Proceedings of the National Academy of Sciences, 102(18), 6407-6412. doi:10.1073/pnas.0500597102Kamtekar, S., Berman, A. J., Wang, J., Lázaro, J. M., de Vega, M., Blanco, L., … Steitz, T. A. (2004). Insights into Strand Displacement and Processivity from the Crystal Structure of the Protein-Primed DNA Polymerase of Bacteriophage φ29. Molecular Cell, 16(4), 609-618. doi:10.1016/j.molcel.2004.10.019Chrysogelos, S., & Griffith, J. (1982). Escherichia coli single-strand binding protein organizes single-stranded DNA in nucleosome-like units. Proceedings of the National Academy of Sciences, 79(19), 5803-5807. doi:10.1073/pnas.79.19.5803Hamon, L., Pastre, D., Dupaigne, P., Breton, C. L., Cam, E. L., & Pietrement, O. (2007). High-resolution AFM imaging of single-stranded DNA-binding (SSB) protein--DNA complexes. Nucleic Acids Research, 35(8), e58-e58. doi:10.1093/nar/gkm147Takamatsu, C., Umeda, S., Ohsato, T., Ohno, T., Abe, Y., Fukuoh, A., … Kang, D. (2002). Regulation of mitochondrial D‐loops by transcription factor A and single‐stranded DNA‐binding protein. EMBO reports, 3(5), 451-456. doi:10.1093/embo-reports/kvf099Wang, Y., & Bogenhagen, D. F. (2006). Human Mitochondrial DNA Nucleoids Are Linked to Protein Folding Machinery and Metabolic Enzymes at the Mitochondrial Inner Membrane. Journal of Biological Chemistry, 281(35), 25791-25802. doi:10.1074/jbc.m604501200Brown, T. A. (2005). Replication of mitochondrial DNA occurs by strand displacement with alternative light-strand origins, not via a strand-coupled mechanism. Genes & Development, 19(20), 2466-2476. doi:10.1101/gad.135210

Ab initio and finite-temperature molecular dynamics studies of lattice resistance in tantalum

This manuscript explores the apparent discrepancy between experimental data and theoretical calculations of the lattice resistance of bcc tantalum. We present the first results for the temperature dependence of the Peierls stress in this system and the first ab initio calculation of the zero-temperature Peierls stress to employ periodic boundary conditions, which are those best suited to the study of metallic systems at the electron-structure level. Our ab initio value for the Peierls stress is over five times larger than current extrapolations of experimental lattice resistance to zero-temperature. Although we do find that the common techniques for such extrapolation indeed tend to underestimate the zero-temperature limit, the amount of the underestimation which we observe is only 10-20%, leaving open the possibility that mechanisms other than the simple Peierls stress are important in controlling the process of low temperature slip.Comment: 12 pages and 9 figure

Unital Quantum Channels - Convex Structure and Revivals of Birkhoff's Theorem

The set of doubly-stochastic quantum channels and its subset of mixtures of unitaries are investigated. We provide a detailed analysis of their structure together with computable criteria for the separation of the two sets. When applied to O(d)-covariant channels this leads to a complete characterization and reveals a remarkable feature: instances of channels which are not in the convex hull of unitaries can return to it when either taking finitely many copies of them or supplementing with a completely depolarizing channel. In these scenarios this implies that a channel whose noise initially resists any environment-assisted attempt of correction can become perfectly correctable.Comment: 31 page