210 research outputs found

    Towards Ocean Grazer's Modular Power Take-Off System Modeling:A Port-Hamiltonian Approach

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    This paper presents a modular modeling framework for the Ocean Grazer's Power Take-Off (PTO) system, which operates as an array of point-absorber type devices connected to a hydraulic system. The modeling is based on the port-Hamiltonian (PH) framework that enables energy-based analysis and control of the PTO system. Firstly, a modular model of a point-absorber hydraulic system, which represents the main building block of the PTO, is presented. The model consists of wave-mechanical and hydraulic subsystems that are interconnected with a transformer-type interconnection. Secondly, we show passivity of the point-absorber hydraulic element and the accumulation of potential energy, which is due to the novel pumping mechanism of the point-absorber. Finally, we illustrate these properties through simulation results

    Genome-wide analysis of porcine backfat and intramuscular fat fatty acid composition using high-density genotyping and expression data

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    [EN] Background: Porcine fatty acid composition is a key factor for quality and nutritive value of pork. Several QTLs for fatty acid composition have been reported in diverse fat tissues. The results obtained so far seem to point out different genetic control of fatty acid composition conditional on the fat deposits. Those studies have been conducted using simple approaches and most of them focused on one single tissue. The first objective of the present study was to identify tissue-specific and tissue-consistent QTLs for fatty acid composition in backfat and intramuscular fat, combining linkage mapping and GWAS approaches and conducted under single and multitrait models. A second aim was to identify powerful candidate genes for these tissue-consistent QTLs, using microarray gene expression data and following a targeted genetical genomics approach. Results: The single model analyses, linkage and GWAS, revealed over 30 and 20 chromosomal regions, 24 of them identified here for the first time, specifically associated to the content of diverse fatty acids in BF and IMF, respectively. The analyses with multitrait models allowed identifying for the first time with a formal statistical approach seven different regions with pleiotropic effects on particular fatty acids in both fat deposits. The most relevant were found on SSC8 for C16:0 and C16:1(n-7) fatty acids, detected by both linkage and GWAS approaches. Other detected pleiotropic regions included one on SSC1 for C16:0, two on SSC4 for C16:0 and C18:2, one on SSC11 for C20:3 and the last one on SSC17 for C16:0. Finally, a targeted eQTL scan focused on regions showing tissue consistent effects was conducted with Longissimus and fat gene expression data. Some powerful candidate genes and regions were identified such as the PBX1, RGS4, TRIB3 and a transcription regulatory element close to ELOVL6 gene to be further studied. Conclusions: Complementary genome scans have confirmed several chromosome regions previously associated to fatty acid composition in backfat and intramuscular fat, but even more, to identify new ones. Although most of the detected regions were tissue-specific, supporting the hypothesis that the major part of genes affecting fatty acid composition differs among tissues, seven chromosomal regions showed tissue-consistent effects. Additional gene expression analyses have revealed powerful target regions to carry the mutation responsible for the pleiotropic effects.This work was funded by the MICINN project AGL2011-29821-C02 (Ministerio de Economia y Competitividad). We thank to Fabian Garcia, Anna Mercade and Carmen Barragan for their assistance in DNA preparation and SNP genotyping.Muñoz, M.; RodrĂ­guez, MC.; Alves, E.; Folch, J.; Ibañez Escriche, N.; SiliĂł, L.; FernĂĄndez, A. (2013). Genome-wide analysis of porcine backfat and intramuscular fat fatty acid composition using high-density genotyping and expression data. BMC Genomics. 14. https://doi.org/10.1186/1471-2164-14-845S14Lichtenstein, A. H. (2003). Dietary Fat and Cardiovascular Disease Risk: Quantity or Quality? Journal of Women’s Health, 12(2), 109-114. doi:10.1089/154099903321576493JimĂ©nez-Colmenero, F., Ventanas, J., & ToldrĂĄ, F. (2010). Nutritional composition of dry-cured ham and its role in a healthy diet. Meat Science, 84(4), 585-593. doi:10.1016/j.meatsci.2009.10.029Webb, E. C., & O’Neill, H. A. (2008). The animal fat paradox and meat quality. Meat Science, 80(1), 28-36. doi:10.1016/j.meatsci.2008.05.029Wood, J. D., Enser, M., Fisher, A. V., Nute, G. R., Sheard, P. R., Richardson, R. I., 
 Whittington, F. M. (2008). Fat deposition, fatty acid composition and meat quality: A review. Meat Science, 78(4), 343-358. doi:10.1016/j.meatsci.2007.07.019Martı́n, L., TimĂłn, M. L., PetrĂłn, M. J., Ventanas, J., & Antequera, T. (2000). Evolution of volatile aldehydes in Iberian ham matured under different processing conditions. Meat Science, 54(4), 333-337. doi:10.1016/s0309-1740(99)00107-2FernĂĄndez, A., de Pedro, E., NĂșñez, N., SiliĂł, L., Garcı́a-Casco, J., & Rodrı́guez, C. (2003). Genetic parameters for meat and fat quality and carcass composition traits in Iberian pigs. Meat Science, 64(4), 405-410. doi:10.1016/s0309-1740(02)00207-3Sellier, P., Maignel, L., & Bidanel, J. P. (2009). Genetic parameters for tissue and fatty acid composition of backfat, perirenal fat and longissimus muscle in Large White and Landrace pigs. animal, 4(4), 497-504. doi:10.1017/s1751731109991261Suzuki, K., Ishida, M., Kadowaki, H., Shibata, T., Uchida, H., & Nishida, A. (2006). Genetic correlations among fatty acid compositions in different sites of fat tissues, meat production, and meat quality traits in Duroc pigs. Journal of Animal Science, 84(8), 2026-2034. doi:10.2527/jas.2005-660Clop, A., Ovilo, C., Perez-Enciso, M., Cercos, A., Tomas, A., Fernandez, A., 
 Noguera, J. L. (2003). Detection of QTL affecting fatty acid composition in the pig. Mammalian Genome, 14(9), 650-656. doi:10.1007/s00335-002-2210-7Nii, M., Hayashi, T., Tani, F., Niki, A., Mori, N., Fujishima-Kanaya, N., 
 Mikawa, S. (2006). Quantitative trait loci mapping for fatty acid composition traits in perirenal and back fat using a Japanese wild boar × Large White intercross. Animal Genetics, 37(4), 342-347. doi:10.1111/j.1365-2052.2006.01485.xRamayo-Caldas, Y., MercadĂ©, A., CastellĂł, A., Yang, B., RodrĂ­guez, C., Alves, E., 
 Folch, J. M. (2012). Genome-wide association study for intramuscular fatty acid composition in an Iberian × Landrace cross1. Journal of Animal Science, 90(9), 2883-2893. doi:10.2527/jas.2011-4900Uemoto, Y., Soma, Y., Sato, S., Ishida, M., Shibata, T., Kadowaki, H., 
 Suzuki, K. (2011). Genome-wide mapping for fatty acid composition and melting point of fat in a purebred Duroc pig population. Animal Genetics, 43(1), 27-34. doi:10.1111/j.1365-2052.2011.02218.xGuo, T., Ren, J., Yang, K., Ma, J., Zhang, Z., & Huang, L. (2009). Quantitative trait loci for fatty acid composition in longissimus dorsi and abdominal fat: results from a White Duroc × Erhualian intercross F2population. Animal Genetics, 40(2), 185-191. doi:10.1111/j.1365-2052.2008.01819.xRamos, A. M., Crooijmans, R. P. M. A., Affara, N. A., Amaral, A. J., Archibald, A. L., Beever, J. E., 
 Groenen, M. A. M. (2009). Design of a High Density SNP Genotyping Assay in the Pig Using SNPs Identified and Characterized by Next Generation Sequencing Technology. PLoS ONE, 4(8), e6524. doi:10.1371/journal.pone.0006524Corominas, J., Ramayo-Caldas, Y., Puig-Oliveras, A., PĂ©rez-Montarelo, D., Noguera, J. L., Folch, J. M., & Ballester, M. (2013). Polymorphism in the ELOVL6 Gene Is Associated with a Major QTL Effect on Fatty Acid Composition in Pigs. PLoS ONE, 8(1), e53687. doi:10.1371/journal.pone.0053687Ponsuksili, S., Jonas, E., Murani, E., Phatsara, C., Srikanchai, T., Walz, C., 
 Wimmers, K. (2008). Trait correlated expression combined with expression QTL analysis reveals biological pathways and candidate genes affecting water holding capacity of muscle. BMC Genomics, 9(1), 367. doi:10.1186/1471-2164-9-367Steibel, J. P., Bates, R. O., Rosa, G. J. M., Tempelman, R. J., Rilington, V. D., Ragavendran, A., 
 Ernst, C. W. (2011). Genome-Wide Linkage Analysis of Global Gene Expression in Loin Muscle Tissue Identifies Candidate Genes in Pigs. PLoS ONE, 6(2), e16766. doi:10.1371/journal.pone.0016766Cïżœnovas, A., Quintanilla, R., Amills, M., & Pena, R. N. (2010). Muscle transcriptomic profiles in pigs with divergent phenotypes for fatness traits. BMC Genomics, 11(1), 372. doi:10.1186/1471-2164-11-372Uemoto, Y., Sato, S., Ohnishi, C., Terai, S., Komatsuda, A., & Kobayashi, E. (2009). The effects of single and epistatic quantitative trait loci for fatty acid composition in a Meishan × Duroc crossbred population. Journal of Animal Science, 87(11), 3470-3476. doi:10.2527/jas.2009-1917Muñoz, M., Alves, E., Ramayo-Caldas, Y., Casellas, J., RodrĂ­guez, C., Folch, J. M., 
 FernĂĄndez, A. I. (2011). Recombination rates across porcine autosomes inferred from high-density linkage maps. Animal Genetics, 43(5), 620-623. doi:10.1111/j.1365-2052.2011.02301.xQuintanilla, R., Pena, R. N., Gallardo, D., CĂĄnovas, A., RamĂ­rez, O., DĂ­az, I., 
 Amills, M. (2011). Porcine intramuscular fat content and composition are regulated by quantitative trait loci with muscle-specific effects1. Journal of Animal Science, 89(10), 2963-2971. doi:10.2527/jas.2011-3974Liaubet, L., Lobjois, V., Faraut, T., Tircazes, A., Benne, F., Iannuccelli, N., 
 Cherel, P. (2011). Genetic variability of transcript abundance in pig peri-mortem skeletal muscle: eQTL localized genes involved in stress response, cell death, muscle disorders and metabolism. BMC Genomics, 12(1). doi:10.1186/1471-2164-12-548Mitchell-Olds, T. (2010). Complex-trait analysis in plants. Genome Biology, 11(4), 113. doi:10.1186/gb-2010-11-4-113Scoggan, K. A., Jakobsson, P.-J., & Ford-Hutchinson, A. W. (1997). Production of Leukotriene C4in Different Human Tissues Is Attributable to Distinct Membrane Bound Biosynthetic Enzymes. Journal of Biological Chemistry, 272(15), 10182-10187. doi:10.1074/jbc.272.15.10182JAKOBSSON, A., WESTERBERG, R., & JACOBSSON, A. (2006). Fatty acid elongases in mammals: Their regulation and roles in metabolism. Progress in Lipid Research, 45(3), 237-249. doi:10.1016/j.plipres.2006.01.004Iankova, I., Chavey, C., Clapé, C., Colomer, C., Guérineau, N. C., Grillet, N., 
 Fajas, L. (2008). Regulator of G Protein Signaling-4 Controls Fatty Acid and Glucose Homeostasis. Endocrinology, 149(11), 5706-5712. doi:10.1210/en.2008-0717Angyal, A., & Kiss-Toth, E. (2012). The tribbles gene family and lipoprotein metabolism. Current Opinion in Lipidology, 23(2), 122-126. doi:10.1097/mol.0b013e3283508c3bÓvilo, C., PĂ©rez-Enciso, M., BarragĂĄn, C., Clop, A., RodrĂ­guez, C., Oliver, M. A., 
 Noguera, J. L. (2000). A QTL for intramuscular fat and backfat thickness is located on porcine Chromosome 6. Mammalian Genome, 11(4), 344-346. doi:10.1007/s003350010065Veroneze, R., Lopes, P. S., GuimarĂŁes, S. E. F., Silva, F. F., Lopes, M. S., Harlizius, B., & Knol, E. F. (2013). Linkage disequilibrium and haplotype block structure in six commercial pig lines. Journal of Animal Science, 91(8), 3493-3501. doi:10.2527/jas.2012-6052Storey, J. D., & Tibshirani, R. (2003). Statistical significance for genomewide studies. Proceedings of the National Academy of Sciences, 100(16), 9440-9445. doi:10.1073/pnas.1530509100Tsai, S., Cassady, J. P., Freking, B. A., Nonneman, D. J., Rohrer, G. A., & Piedrahita, J. A. (2006). Annotation of the Affymetrix1 porcine genome microarray. Animal Genetics, 37(4), 423-424. doi:10.1111/j.1365-2052.2006.01460.xNyholt, D. R. (2004). A Simple Correction for Multiple Testing for Single-Nucleotide Polymorphisms in Linkage Disequilibrium with Each Other. The American Journal of Human Genetics, 74(4), 765-769. doi:10.1086/383251Moskvina, V., & Schmidt, K. M. (2008). On multiple-testing correction in genome-wide association studies. Genetic Epidemiology, 32(6), 567-573. doi:10.1002/gepi.20331Benjamini, Y., & Yekutieli, D. (2005). Quantitative Trait Loci Analysis Using the False Discovery Rate. Genetics, 171(2), 783-790. doi:10.1534/genetics.104.03669

    Hidden imputations and the kaplan-meier estimator

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    The Kaplan-Meier (KM) estimator of the survival function imputes event times for right-censored and left-truncated observations, but these imputations are hidden and therefore sometimes unrecognized by applied health scientists. Using a simple example data set and the redistribution algorithm, we illustrate how imputations are made by the KM estimator. We also discuss the assumptions necessary for valid analyses of survival data. Illustrating imputations hidden by the KM estimator helps to clarify these assumptions and therefore may reduce inappropriate inferences

    A new experimental technique for quantifying the galvanic coupling effects on stainless steel during tribocorrosion under equilibrium conditions

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    Galvanic coupling during tribocorrosion of passive metals at open circuit potential (OCP) generates a wear-accelerated corrosion process within the depassivated area (worn surface) that is electrically in contact with the still passive one. The galvanic coupling effect at OCP was recently modeled using an electrochemical approach allowing for the theoretical quantification of the wear-accelerated corrosion under equilibrium conditions. Despite the usefulness of this model that mathematically determines the electrochemical conditions inside the wear track in terms of anode potential via the approximation of the net anodic current density, an experimental technique allowing for their experimental determination is essential in the effort to verify the galvanic coupling models and further understand the tribocorrosion mechanisms at OCP. In the present work, a new experimental technique based on galvanic current and potential measurements through a Zero-Resistance Ammeter (ZRA) for quantifying the electrode potential and anodic current inside the wear track during rubbing at OCP has been assessed. This experimental set-up has allowed for the first time to determine the prevailing electrochemical conditions (electrode potential and anodic current) inside the wear track by solely exposing the wear track to the electrolyte and physically separating the cathode from the anode (wear track). The effects of sliding wear at open circuit potential have been investigated for a super duplex stainless steel (UNS S32750) in 3.4 wt% NaCl. The new experimental set-up proposed in this work separates the cathode from the anode and exposes solely the wear track to the electrolyte. Using well-established electrochemical theories, the effect of the extent of the galvanic coupling on wear at the open circuit potential conditions has been quantified.The authors would like to thank the support from the European Union for funding C. Torres through the Leonardo da Vinci Mobility program. C.B. von der Ohe and E. Jensen are also acknowledged for having taken part in the initial phase 1151 of this long project. Dr. N. Papageorgiou (NTNU) is also acknowledged for the input and calculations in the modeling part and for preparing Figs. 6-9 of the paper.Espallargas Álvarez, N.; Johnsen, R.; Torres, C.; Igual Muñoz, AN. (2013). A new experimental technique for quantifying the galvanic coupling effects on stainless steel during tribocorrosion under equilibrium conditions. Wear. 307(1-2):190-197. doi:10.1016/j.wear.2013.08.026S1901973071-

    Diversity across major and candidate genes in European local pig breeds

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    The aim of this work was to analyse the distribution of causal and candidate mutations associated to relevant productive traits in twenty local European pig breeds. Also, the potential of the SNP panel employed for elucidating the genetic structure and relationships among breeds was evaluated. Most relevant genes and mutations associated with pig morphological, productive, meat quality, reproductive and disease resistance traits were prioritized and analyzed in a maximum of 47 blood samples from each of the breeds (Alentejana, Apulo-Calabrese, Basque, Bísara, Majorcan Black, Black Slavonian (Crna slavonska), Casertana, Cinta Senese, Gascon, Iberian, Krskopolje (Krskopoljski), Lithuanian indigenous wattle, Lithuanian White Old Type, Mora Romagnola, Moravka, Nero Siciliano, Sarda, Schwa-bisch-Hallisches Schwein (Swabian Hall pig), Swallow-Bellied Mangalitsa and Turopolje). We successfully analyzed allelic variation in 39 polymorphisms, located in 33 candidate genes. Results provide relevant information regarding genetic diversity and segregation of SNPs associated to production and quality traits. Coat color and morphological trait-genes that show low level of segregation, and fixed SNPs may be useful for traceability. On the other hand, we detected SNPs which may be useful for association studies as well as breeding programs. For instance, we observed predominance of alleles that might be unfavorable for disease resistance and boar taint in most breeds and segregation of many alleles involved in meat quality, fatness and growth traits. Overall, these findings provide a detailed catalogue of segregating candidate SNPs in 20 European local pig breeds that may be useful for traceability purposes, for association studies and for breeding schemes. Population genetic analyses based on these candidate genes are able to uncover some clues regarding the hidden genetic substructure of these populations, as the extreme genetic closeness between Iberian and Alentejana breeds and an uneven admixture of the breeds studied. The results are in agreement with available knowledge regarding breed history and management, although largest panels of neutral markers should be employed to get a deeper understanding of the population’s structure and relationships

    High-resolution bathymetry of the Blanes Canyon (NW Mediterranean)

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    5th International Network for Submarine Canyon Investigation and Scientific Exchange International Symposium (INCISE), 14-18 June 2021Submarine canyons are complex geomorphological features that have been identified as potential hotspots of biodiversity, which has led to many canyons being mapped and studied at high resolution (tens of meters). In this work, we present the first complete very-high resolution mapping of the Blanes submarine canyon in the northwestern Mediterranean, based on a compilation of swath bathymetry data acquired during different cruises, spanning between 2011 and 2020. The integrated data set completes and extends previous bathymetric datasets on the canyon rim and adjacent continental shelf acquired during the ESPACE programme in 2004. The grid spacing of the compilation map varies from 4 m for the canyon rim and adjacent shelf, 15 m for the head and upper canyon region and 25 m for the middle and lower canyon region. The Blanes Canyon deeply incises the continental shelf, showing an orientation parallel to the coastline at its head. Down-canyon, it displays a meandering course with a strong structural control, showing rectilinear canyon portions characterized by a flat-floored axis and steep terrains (>50Âș) on both canyon flanks, with the presence of networks of gullies and subhorizontal layered walls. The high resolution map has allowed to identify potential areas along the submarine canyon flanks that might provide suitable environmental conditions for hosting benthic ecosystems, particularly cold-water corals (CWCs). These sites were recently explored during the ABRIC Spanish National Project using the hybrid remotely operated vehicle (H-ROV) Ariane and the inspection-class ROV Liropus to explore the benthic communities and to collect specimen samples, complementing the previous ROV dataset acquired during the ABIDES Project. Collected data allowed for the compilation of an inventory of the most representative and relevant benthic species and communities observed within the Blanes Canyon. This information will be shared with the Blanes fishermen’s guild in the framework of an outreach project funded by the Fisheries Local Action Groups (GALP), to provide awareness of the presence and abundance of such vulnerable marine ecosystems in the Blanes Canyon, and to expand the spatial information provided by the ROV surveys by adding the local fishermen knowledgPeer reviewe

    Colossal dielectric constants in transition-metal oxides

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    Many transition-metal oxides show very large ("colossal") magnitudes of the dielectric constant and thus have immense potential for applications in modern microelectronics and for the development of new capacitance-based energy-storage devices. In the present work, we thoroughly discuss the mechanisms that can lead to colossal values of the dielectric constant, especially emphasising effects generated by external and internal interfaces, including electronic phase separation. In addition, we provide a detailed overview and discussion of the dielectric properties of CaCu3Ti4O12 and related systems, which is today's most investigated material with colossal dielectric constant. Also a variety of further transition-metal oxides with large dielectric constants are treated in detail, among them the system La2-xSrxNiO4 where electronic phase separation may play a role in the generation of a colossal dielectric constant.Comment: 31 pages, 18 figures, submitted to Eur. Phys. J. for publication in the Special Topics volume "Cooperative Phenomena in Solids: Metal-Insulator Transitions and Ordering of Microscopic Degrees of Freedom

    Diversity across major and candidate genes in European local pig breeds

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    The aim of this work was to analyse the distribution of causal and candidate mutations associated to relevant productive traits in twenty local European pig breeds. Also, the potential of the SNP panel employed for elucidating the genetic structure and relationships among breeds was evaluated. Most relevant genes and mutations associated with pig morphological, productive, meat quality, reproductive and disease resistance traits were prioritized and analyzed in a maximum of 47 blood samples from each of the breeds (Alentejana, Apulo-Calabrese, Basque, Bísara, Majorcan Black, Black Slavonian (Crna slavonska), Casertana, Cinta Senese, Gascon, Iberian, Krƥkopolje (Krƥkopoljski), Lithuanian indigenous wattle, Lithuanian White Old Type, Mora Romagnola, Moravka, Nero Siciliano, Sarda, SchwÀbisch-HÀllisches Schwein (Swabian Hall pig), Swallow-Bellied Mangalitsa and Turopolje). We successfully analyzed allelic variation in 39 polymorphisms, located in 33 candidate genes. Results provide relevant information regarding genetic diversity and segregation of SNPs associated to production and quality traits. Coat color and morphological trait-genes that show low level of segregation, and fixed SNPs may be useful for traceability. On the other hand, we detected SNPs which may be useful for association studies as well as breeding programs. For instance, we observed predominance of alleles that might be unfavorable for disease resistance and boar taint in most breeds and segregation of many alleles involved in meat quality, fatness and growth traits. Overall, these findings provide a detailed catalogue of segregating candidate SNPs in 20 European local pig breeds that may be useful for traceability purposes, for association studies and for breeding schemes. Population genetic analyses based on these candidate genes are able to uncover some clues regarding the hidden genetic substructure of these populations, as the extreme genetic closeness between Iberian and Alentejana breeds and an uneven admixture of the breeds studied. The results are in agreement with available knowledge regarding breed history and management, although largest panels of neutral markers should be employed to get a deeper understanding of the population's structure and relationships

    Grain Surface Models and Data for Astrochemistry

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    AbstractThe cross-disciplinary field of astrochemistry exists to understand the formation, destruction, and survival of molecules in astrophysical environments. Molecules in space are synthesized via a large variety of gas-phase reactions, and reactions on dust-grain surfaces, where the surface acts as a catalyst. A broad consensus has been reached in the astrochemistry community on how to suitably treat gas-phase processes in models, and also on how to present the necessary reaction data in databases; however, no such consensus has yet been reached for grain-surface processes. A team of ∌25 experts covering observational, laboratory and theoretical (astro)chemistry met in summer of 2014 at the Lorentz Center in Leiden with the aim to provide solutions for this problem and to review the current state-of-the-art of grain surface models, both in terms of technical implementation into models as well as the most up-to-date information available from experiments and chemical computations. This review builds on the results of this workshop and gives an outlook for future directions
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