Detection of growth-related QTLs in turbot (Scophtalmus maximux)

Background The turbot (Scophthalmus maximus) is a highly appreciated European aquaculture species. Growth related traits constitute the main goal of the ongoing genetic breeding programs of this species. The recent construction of a consensus linkage map in this species has allowed the selection of a panel of 100 homogeneously distributed markers covering the 26 linkage groups (LG) suitable for QTL search. In this study we addressed the detection of QTL with effect on body weight, length and Fulton's condition factor. Results Eight families from two genetic breeding programs comprising 814 individuals were used to search for growth related QTL using the panel of microsatellites available for QTL screening. Two different approaches, maximum likelihood and regression interval mapping, were used in order to search for QTL. Up to eleven significant QTL were detected with both methods in at least one family: four for weight on LGs 5, 14, 15 and 16; five for length on LGs 5, 6, 12, 14 and 15; and two for Fulton's condition factor on LGs 3 and 16. In these LGs an association analysis was performed to ascertain the microsatellite marker with the highest apparent effect on the trait, in order to test the possibility of using them for marker assisted selection. Conclusions The use of regression interval mapping and maximum likelihood methods for QTL detection provided consistent results in many cases, although the high variation observed for traits mean among families made it difficult to evaluate QTL effects. Finer mapping of detected QTL, looking for tightly linked markers to the causative mutation, and comparative genomics are suggested to deepen in the analysis of QTL in turbot so they can be applied in marker assisted selection programs

Breeding Strategies for Weather Resilience in Small Ruminants in Atlantic and Mediterranean Climates

Many efforts are being made to cope with negative consequences of climate change (CC) on livestock. Among them, selective breeding of resilient animals to CC is presented as an opportunity to maintain high levels of performance regardless of variation in weather. In the present work, we proposed a set of breeding strategies to improve weather resilience in dairy goats raised in north-western European Atlantic conditions and dairy sheep raised in Mediterranean conditions while improving production efficiency at the same time. Breeding strategies differed in the selection emphasis placed on resilience traits, ranging from 0 to 40% in the index. Simulations were carried out mimicking real breeding programs including: milk yield, length of productive life, age at first kidding and mastitis incidence in dairy goats and milk, fat and protein yields, and fertility for dairy sheep. Considering the particular climatic conditions in the two regions, the predicted future climate scenarios, and genetic correlations among breeding objectives, resilience was defined as stability to weather changes for dairy goats and as the ability to improve performance under heat stress for dairy sheep. A strategy giving a selection weight of 10 and 20% for goat and sheep resilience, respectively, resulted in the best overall genetic response in terms of both, production and resilience ability. Not considering resilience in breeding programs could lead to a major production loss in future climate scenarios, whereas putting too much emphasis on resilience would result in a limited progress in milk production

Desarrollo, caracterización y utilización de micro esferas basadas en arena negra para la producción fotocatalítica de hidrógeno.

60 páginas incluye indice ilustraciones, diagramas y fotografíasEn el presente estudio se sintetizaron microesferas de arenas negras para la producción fotocatalítica de hidrógeno. Las arenas negras se obtuvieron de las playas de Santa Marta (Colombia), la muestra fue separada magnéticamente, molida y tamizada por malla 53 µm. Las microesferas se elaboraron en una matriz de alginato de sodio al variando la relación entre alginato:mineral 9:1, 8:2 y 7:3, seleccionando esta última como objeto de estudio debido a su mayor resistencia mecánica. Posteriormente se caracterizó su composición química, morfología, respuesta óptica y estructura mediante las técnicas XRF, SEM-EDX, espectrofotometría UV-VIS y FTIR respectivamente, determinando que en su composición existen agentes fotocatalíticamente activos como el TiO2 y α-Fe2O3 y que su gap directo permitido es 2.24 eV equivalente a una longitud de onda de 553 nm-1 la cual absorbe en el espectro visible. Finalmente se realizaron ensayos fotocatalíticos determinando que el comportamiento de la tasa de producción de hidrógeno es inversamente proporcional a la concentración de microesferas.

Evaluación de la transmisión de la tasa de interés de referencia a las tasas de interés del sistema financiero Colombiano

This paper studies monetary policy transmission using several statistical tools -- We find that the relationships between the policy interest rate and the financial system’s interest rates are positive and statistically significant, and transmission is complete eight months after policy shocks occur -- The speed of transmission varies according to the type of interest rates -- Transmission is faster for interest rates on loans provided to households, and is particularly rapid and complete for rates on preferential commercial loans -- Transmission is slower for credit card and mortgage rates, due to regulatory issues (interest rate ceilings)En este documento se analiza la transmisión de la política monetaria a las tasas de interés de mercado del sistema financiero utilizando diferentes herramientas estadísticas -- La relación existente entre la tasa de política y las tasas de interés de colocación es positiva y significativa, y se presenta una transmisión completa para las diferentes modalidades de crédito después de 8 meses -- La transmisión de la tasa de interés de referencia a las tasas de crédito difiere según las distintas modalidades de préstamo -- Se observa una mayor transmisión y más rápida a las tasas comerciales que a las ofrecidas a los hogares -- En particular, la transmisión a las tasas de crédito preferencial es más rápida y completa -- En cuanto a las tasas de tarjetas de crédito e hipotecarias, la transmisión es más débil debido a su naturaleza, regulación (tasa límite) y rigideces de las misma

Sirba 1.0 information system for ballistic recognition based on the vulger calls found in scenes of crimes

  The bullet casings found at crime scenes, are key to start investigations to clarify the facts. A weapon fring a projectile, leaving a set of marks on the cartridges, many of them in his shorts. In this paper we present an algorithm based on a 2D image taken from a bullet casings shorts, use processing techniques and image analysis to obtain some of these characteristic marks left by the weapon, then, based on a database that records the bullet casings found previously in other crime scenes and the K-nn algorithm used to relate the bullet casings with previously registered weapons or with other cartridges found in other scenes. To determine the importance of each characteristic marks, we design a genetic algorithm to further defne the optimal number of neighbors. An experiment was conducted with 15 weapons fred 10 or 30 times each obtained promising results. Las vainillas encontradas en las escenas de crímenes, son pieza clave para iniciar las investigaciones que esclarecen los hechos. Un arma al disparar un proyectil, deja un conjunto de marcas impresas en las vainillas, muchas de ellas en su culote. En éste artículo se presenta un algoritmo que partiendo de una imagen 2D, tomada del culote de una vainilla, utiliza técnicas de procesamiento y análisis de imágenes para obtener algunas de dichas marcas características que deja el arma, luego, basado en una base de datos que registra las vainillas encontradas previamente en otras escenas de crímenes y el algoritmo K-nn permite relacionar la vainilla con armas previamente registradas o con otras vainillas encontradas en otras escenas. Para determinar la importancia de cada característica, se diseño un algoritmo genético que además defne el número de vecinos óptimo. Se realizó un experimento con 15 armas disparadas 10 o 30 veces cada una, obteniendo resultados promisorios.  &nbsp

Joint genomic prediction of canine hip dysplasia in UK and US Labrador Retrievers

Canine hip dysplasia, a debilitating orthopedic disorder that leads to osteoarthritis and cartilage degeneration, is common in several large-sized dog breeds and shows moderate heritability suggesting that selection can reduce prevalence. Estimating genomic breeding values require large reference populations, which are expensive to genotype for development of genomic prediction tools. Combining datasets from different countries could be an option to help build larger reference datasets without incurring extra genotyping costs. Our objective was to evaluate genomic prediction based on a combination of UK and US datasets of genotyped dogs with records of Norberg angle scores, related to canine hip dysplasia. Prediction accuracies using a single population were 0.179 and 0.290 for 1,179 and 242 UK and US Labrador Retrievers, respectively. Prediction accuracies changed to 0.189 and 0.260, with an increased bias of genomic breeding values when using a joint training set (biased upwards for the US population and downwards for the UK population). Our results show that in this study of canine hip dysplasia, little or no benefit was gained from using a joint training set as compared to using a single population as training set. We attribute this to differences in the genetic background of the two populations as well as the small sample size of the US dataset

Genomic Regions Underlying Susceptibility to Bovine Tuberculosis in Holstein-Friesian Cattle

BACKGROUND: The significant social and economic loss as a result of bovine tuberculosis (bTB) presents a continuous challenge to cattle industries in the UK and worldwide. However, host genetic variation in cattle susceptibility to bTB provides an opportunity to select for resistant animals and further understand the genetic mechanisms underlying disease dynamics. METHODS: The present study identified genomic regions associated with susceptibility to bTB using genome-wide association (GWA), regional heritability mapping (RHM) and chromosome association approaches. Phenotypes comprised de-regressed estimated breeding values of 804 Holstein-Friesian sires and pertained to three bTB indicator traits: i) positive reactors to the skin test with positive post-mortem examination results (phenotype 1); ii) positive reactors to the skin test regardless of post-mortem examination results (phenotype 2) and iii) as in (ii) plus non-reactors and inconclusive reactors to the skin tests with positive post-mortem examination results (phenotype 3). Genotypes based on the 50 K SNP DNA array were available and a total of 34,874 SNPs remained per animal after quality control. RESULTS: The estimated polygenic heritability for susceptibility to bTB was 0.26, 0.37 and 0.34 for phenotypes 1, 2 and 3, respectively. GWA analysis identified a putative SNP on Bos taurus autosomes (BTA) 2 associated with phenotype 1, and another on BTA 23 associated with phenotype 2. Genomic regions encompassing these SNPs were found to harbour potentially relevant annotated genes. RHM confirmed the effect of these genomic regions and identified new regions on BTA 18 for phenotype 1 and BTA 3 for phenotypes 2 and 3. Heritabilities of the genomic regions ranged between 0.05 and 0.08 across the three phenotypes. Chromosome association analysis indicated a major role of BTA 23 on susceptibility to bTB. CONCLUSION: Genomic regions and candidate genes identified in the present study provide an opportunity to further understand pathways critical to cattle susceptibility to bTB and enhance genetic improvement programmes aiming at controlling and eradicating the disease. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12863-017-0493-7) contains supplementary material, which is available to authorized users