Gene Expression Response to Sea Lice in Atlantic Salmon Skin: RNA Sequencing Comparison Between Resistant and Susceptible Animals

Sea lice are parasitic copepods that cause large economic losses to salmon aquaculture worldwide. Frequent chemotherapeutic treatments are typically required to control this parasite, and alternative measures such as breeding for improved host resistance are desirable. Insight into the host–parasite interaction and mechanisms of host resistance can lead to improvements in selective breeding, and potentially novel treatment targets. In this study, RNA sequencing was used to study the skin transcriptome of Atlantic salmon (Salmo salar) parasitized with sea lice (Caligus rogercresseyi). The overall aims were to compare the transcriptomic profile of skin at louse attachment sites and “healthy” skin, and to assess differences in gene expression response between animals with varying levels of resistance to the parasite. Atlantic salmon pre-smolts were challenged with C. rogercresseyi, growth and lice count measurements were taken for each fish. 21 animals were selected and RNA-Seq was performed on skin from a louse attachment site, and skin distal to attachment sites for each animal. These animals were classified into family-balanced groups according to the traits of resistance (high vs. low lice count), and growth during infestation. Overall comparison of skin from louse attachment sites vs. healthy skin showed that 4,355 genes were differentially expressed, indicating local up-regulation of several immune pathways and activation of tissue repair mechanisms. Comparison between resistant and susceptible animals highlighted expression differences in several immune response and pattern recognition genes, and also myogenic and iron availability factors. Components of the pathways involved in differential response to sea lice may be targets for studies aimed at improved or novel treatment strategies, or to prioritize candidate functional polymorphisms to enhance genomic selection for host resistance in commercial salmon breeding programs

Combined Effects of the North Atlantic Oscillation and the Arctic Oscillation on Sea Surface Temperature in the Alborán Sea

We explored the possible effects of the North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) on interannual sea surface temperature (SST) variations in the Albora´n Sea, both separately and combined. The probability of observing mean annual SST values higher than average was related to NAO and AO values of the previous year. The effect of NAO on SST was negative, while that of AO was positive. The pure effects of NAO and AO on SST are obscuring each other, due to the positive correlation between them. When decomposing SST, NAO and AO in seasonal values, we found that variation in mean annual SST and mean winter SST was significantly related to the mean autumn NAO of the previous year, while mean summer SST was related to mean autumn AO of the previous year. The one year delay in the effect of the NAO and AO on the SST could be partially related to the amount of accumulated snow, as we found a significant correlation between the total snow in the North Albora´n watershed for a year with the annual average SST of the subsequent year. A positive AO implies a colder atmosphere in the Polar Regions, which could favour occasional cold waves over the Iberian Peninsula which, when coupled with precipitations favoured by a negative NAO, may result in snow precipitation. This snow may be accumulated in the high peaks and melt down in spring-summer of the following year, which consequently increases the runoff of freshwater to the sea, which in turn causes a diminution of sea surface salinity and density, and blocks the local upwelling of colder water, resulting in a higher SST.CGL2009-11316 (Ministerio de Ciencia e Innovación, Spain, and FEDER

Shape index, Brouwer degree and Poincaré-Hopf theorem

In this paper we study the relationship of the Brouwer degree of a vector field with the dynamics of the induced flow. Analogous relations are studied for the index of a vector field. We obtain new forms of the Poincaré-Hopf theorem and of the Borsuk and Hirsch antipodal theorems. As an application, we calculate the Brouwer degree of the vector field of the Lorenz equations in isolating blocks of the Lorenz strange set.Depto. de Álgebra, Geometría y TopologíaFac. de Ciencias MatemáticasFALSEMinisterio de Ciencia, Innovación y Universidadesunpu

Population Genomic Structure and Genome-Wide Linkage Disequilibrium in Farmed Atlantic Salmon (Salmo salar L.) Using Dense SNP Genotypes

Chilean Farmed Atlantic salmon (Salmo salar) populations were established with individuals of both European and North American origins. These populations are expected to be highly genetically differentiated due to evolutionary history and poor gene flow between ancestral populations from different continents. The extent and decay of linkage disequilibrium (LD) among single nucleotide polymorphism (SNP) impacts the implementation of genome-wide association studies and genomic selection and provides relevant information about demographic processes of fish populations. We assessed the population structure and characterized the extent and decay of LD in three Chilean commercial populations of Atlantic salmon with North American (NAM), Scottish (SCO), and Norwegian (NOR) origin. A total of 123 animals were genotyped using a 159 K SNP Axiom® myDesignTM Genotyping Array. A total of 32 K SNP markers, representing the common SNPs along the three populations after quality control were used. The principal component analysis explained 78.9% of the genetic diversity between populations, clearly discriminating between populations of North American and European origin, and also between European populations. NAM had the lowest effective population size, followed by SCO and NOR. Large differences in the LD decay were observed between populations of North American and European origin. An r2 threshold of 0.2 was estimated for marker pairs separated by 7,800, 64, and 50 kb in the NAM, SCO, and NOR populations, respectively. In this study we show that this SNP panel can be used to detect association between markers and traits of interests and also to capture high-resolution information for genome-enabled predictions. Also, we suggest the feasibility to achieve similar prediction accuracies using a smaller SNP data set for the NAM population, compared with samples with European origin which would need a higher density SNP array

Colour changes in Galician granitic stones induced by UV Nd:YAG laser irradiation

Presentado en International Conference Lacona VII, Madrid, Spain, 17-21 September 2007[Resumen]: estudio sobre el cambio de color del granito gallego al limpiarlo mediante láser ultravioleta[Abstract] Laser cleaning has become a high profile and accepted specialized cleaning technique for most stone types. Given that local natural building stone in our region, Galicia (North West of Spain) is granite, our interest was focused on the response of this stone type to laser cleaning. The aim of this work is to determine the change in colour as index of the response of galician granites to UV-Nd:YAG laser exposure. For this purpose samples of commercial granites from different quarries were irradiated at increasing fluences. Colour changes were determined through the analysis of digital images and expressed in the L*a*b* and L*h*C* colour models. The results enable the establishment of application limits of laser cleaning to these material

Alkaline-earth (Be, Mg and Ca) bonds at the origin of huge acidity enhancements

The interaction between alkaline-earth derivatives with the general formula X2M (X = H, F and Cl; M = Be, Mg and Ca) and a set of Lewis bases, including first and second-row hydrides, namely YHn(Y = O, N, F, S, P and Cl) hydrides, as well as other typical cyclic organic bases, such as aniline, 1H-1,2,3-triazole, 1H-tetrazole and phenylphosphine, was investigated using the G4 ab initio composite method. Contrary to what was expected, it was found that the interactions involving Mg and Ca derivatives were not necessarily weaker than those between beryllium bonds. The origin is two-fold: larger deformation of the interacting systems when Be-derivatives are involved and appearance of secondary non-covalent interactions in the formation of some of the Mg- and Ca-containing complexes. Hence, the dissociation of the latter complexes may require higher enthalpies than that of the Be complexes. These deformations are triggered by a significant redistribution of electron density of the two interacting moieties, which also result in dramatic changes in the reactivity of the interacting compounds and in particular in the intrinsic basicity of the Lewis bases investigated, to the point that conventional bases, such as ammonia or aniline, upon complexation with MCl2(M = Be, Mg and Ca), become stronger Brønsted acids than phosphoric acid, whereas other bases, such as 1H-tetrazole, become stronger acids than perchloric acid.This work was carried out with financial support from the Ministerio de Economía, Industria y Competitividad (projects CTQ2015-63997-C2 and CTQ2013-43698-P), by the COST Action CM1204 and Comunidad Autónoma de Madrid (S2013/MIT2841, Fotocarbon

Effect of Alloying Elements on Laser Surface Modification of Powder Metallurgy to Improve Surface Mechanical Properties of Beta Titanium Alloys for Biomedical Application

[Abstract] Beta-type titanium alloy surfaces (Tie35Nbe10Ta (TNT) and Tie30Nbe4Sn (TNS)) weremodified by laser using a power of 1000 W and speed of 6.7 mm/s (Condition A) and a powerof 1500 W with speed of 10 mm/s (Condition B). Increasing laser conditions, the thicknessof the molten layer was also increased. The initial equiaxed grains changes to quiteelongated grains shape. The surfaces were structured undera00martensite,aand matrixb.Thebphase content decreased slightly and thea00phase increased for both alloysincreasing the laser conditions. The condition A increased the elastic modulus (E) anddecreased the hardness while condition B did not affect the mechanical properties surfacefor the TNT system compared to base metal (BM). In TNS system the laser condition Adecreased the E and increased the hardness while increasing the laser parameters (Con-dition B) both E and hardness decreased compared to BM. The laser surface treatment wasinfluenced by the levels of alloying elements present promoting most significant changesin the microstructure and mechanical properties in the TNS systemThis work was supported by the Ministerio Español de Ciencia, Innovación y Universidades, Spain with Grant RTI2018-097810-B-I00, RTI2018-096472-B-I00 and the European Union (EU) through Fondo Europeo de Desarrollo Regional (FEDER), Spai

Intramolecular magnesium bonds in malonaldehyde-like systems. A critical view of the resonance-assisted phenomena

Through the use of high-level G4-theory calculations we have investigated the structure, stability and bonding of a set of Mg derivatives formed by replacing the –OH group of malonaldehyde or only the hydrogen atom of this group by a –MgH group. To give insight on the resonance-assisted phenomenon, which might be involved in the stabilization of these compounds, we also included the corresponding saturated analogues in our survey. The effect of the rigidity of the molecular framework was considered by analyzing the Mg-derivatives of (Z)-4-(hydroxymethylene)cyclobut-2- enone, obtained through the same substitutions mentioned above. The effect of replacing the carbonyl group by an imino group was also contemplated. In all cases, the global minimum is a cyclic conformer stabilized through the formation of rather strong intramolecular magnesium bonds. The strength of these interactions is directly related with the intrinsic basicity of the carbonyl group (or the imino group) and the intrinsic acidity of the –MgH group, rather than with a resonance-assisted phenomenon. As a matter of fact, for all the investigated systems, the conclusion is that resonance in the cyclic conformer is directly correlated with the strength of the intramolecular magnesium bond, and not vice-versa. Interestingly, the strength and characteristics of these interactions for these Mg-containing derivatives are very similar to those of the corresponding Be-containing analoguesWork supported by the Projects CTQ2015-63997-C2 and CTQ2016-76061-P of the Ministerio de Economía y Competitividad of Spain, FOTOCARBON-CM S2013/MIT-2841 of the Comunidad Autónoma de Madrid and by the COST Action CM1204 of the EU Framework Programme. Horizon 202