Microsatellite diversity of the Nordic type of goats in relation to breed conservation: how relevant is pure ancestry?

In the last decades, several endangered breeds of livestock species have been re-established effectively. However, the successful revival of the Dutch and Danish Landrace goats involved crossing with exotic breeds and the ancestry of the current populations is therefore not clear. We have generated genotypes for 27 FAO-recommended microsatellites of these landraces and three phenotypically similar Nordic-type landraces and compared these breeds with central European, Mediterranean and south-west Asian goats. We found decreasing levels of genetic diversity with increasing distance from the south-west Asian domestication site with a south-east-to-north-west cline that is clearly steeper than the Mediterranean east-to-west cline. In terms of genetic diversity, the Dutch Landrace comes next to the isolated Icelandic breed, which has an extremely low diversity. The Norwegian coastal goat and the Finnish and Icelandic landraces are clearly related. It appears that by a combination of mixed origin and a population bottleneck, the Dutch and Danish Land-races are separated from the other breeds. However, the current Dutch and Danish populations with the multicoloured and long-horned appearance effectively substitute for the original breed, illustrating that for conservation of cultural heritage, the phenotype of a breed is more relevant than pure ancestry and the genetic diversity of the original breed. More in general, we propose that for conservation, the retention of genetic diversity of an original breed and of the visual phenotype by which the breed is recognized and defined needs to be considered separately

Predicting proppant flowback from fracture-stimulated wells

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Includes bibliographical references (leaves 92-94).Issued also on microfiche from Lange Micrographics.In this thesis, the usefulness and benefits of predicting proppant flowback in the design stage of hydraulic fracturing treatments are evidenced. A new prediction model, as well as a methodology, is proposed in this work. These tools will help companies handle this phenomenon and consequently conduct more efficient fracturing treatments. Currently, proppant flowback is responsible for creating operational complications, increasing expenses and decreasing the productivity of fracture stimulated wells. So far, there have been some empirical approaches that have tried to explain this phenomenon and have helped identify the most important factors that influence it. However, all previous models have drawbacks and do not extend to all practical applications. In this work, the most relevant studies in the area were analyzed in order to clarify the mechanisms that govern the proppant flowback phenomenon. After doing this, the most consistent available features were included in a proposed semi-mechanistic model. This model is considered to be the most rigorous available approach to predict proppant flowback in future treatments. As part of this study, field cases that reported back-production of proppant were analyzed. From this analysis, it was demonstrated that proppant flowback was possible to anticipate. In addition, it was suggested the inclusion of a "Stability Criterion" in the design of future optimum fracturing treatments

Leading data analytics transformations

Thesis: M.B.A., Massachusetts Institute of Technology, Sloan School of Management, 2017.Cataloged from PDF version of thesis.Includes bibliographical references (pages 77-79).The phenomenal success of big technology companies founded with a strong emphasis on data, has epitomized the rise of the new "digital economy." Large traditional organizations, that were not long ago "on top of the world" are now at a crossroads. Their business models seem threatened by newcomers as they face pressure to "transform" and "modernize." Publicity has reinforced the perception that data can now be exploited and turned into a source of competitive advantage. In this context, data analytics presumably offers a vehicle to hasten this transformation. Who are the individuals leading these transformation efforts? Where do they come from? What are their challenges and perspectives? This thesis attempted to answer these questions and by doing so, uncover the "faces behind the leadership titles." Interviews of 33 individuals leading data analytics in large traditional organizations and under different capacities, (i.e., at the C-Suite, at the senior leadership level and in middle management) had a few elements in common: They articulated the difficulty of change, and the significant challenges in balancing strategic design with political savviness and cultural awareness. At their core, these are true leadership stories. Change management processes and the "Three Perspectives on Organizations" framework offer mechanisms to better understand the root causes for inhibitors of transformation and provide a path to guide data analytics initiatives. Whether data analytics proves to be a "passing fad" or not, by now, it has served as a catalyst for large traditional organizations to embark on transformation initiatives and reexamine ways to remain relevant. Leadership stories will most certainly abound as these organizations attempt to find ways to survive and prosper in what is now the "digital age."by Javier Mauricio Canon Moreno.M.B.A

SINFOR JBO

Tesis de la Sede Principal Uniminuto - BogotáEl objetivo del proyecto es agilizar procesos de inscripción, matricula y el seguimiento de la ruta académica de los estudiantes en el área de coordinación del centro JBO por medio dé un Sistema de Información. Para ello se opta por una serie de pasos basado en la comunicación directa con las personas implicadas que conllevan al entendimiento del problema, el reconocimiento de los procesos y posteriormente sistematización de los mismos, previo análisis y diseño del sistema de información

Restocked and non-restocked populations genetic composition: a case study in red-legged partridge (alectoris rufa)

Release of captive-bred red-legged (Alectoris rufa) partridges is used to reinforce hunting areas where wild populations have decreased in southern European countries. However, breeders have often used other species to improve acclimation to captivity (e.g. Alectoris chukar), producing different degrees of hybridized individuals. In this study, three hunting reserve partitions, characterized by the different likelihood of contact with captive-reared partridges, were sampled and genotyped with 22 microsatellite markers to check for the existence of A. rufa x A. chukar hybridization and to compare the genetic composition of restocked and non-restocked red-legged partridge populations. Our results reveal the efficiency of the marker set used to differentiate among closely related A. rufa partridge populations, and the different genetic composition between captive-reared individuals and wild ones, but also the hybridization with A. chukar partridges on cynegetic farms. These facts must be taken into account and genetic controls of farm breeding stocks should be performed before restocking, both to avoid introgression in wild populations and to guarantee the reintroduction of partridges of known genetic origin in each area

SNP included in candidate genes involved in muscle, lipid and energy metabolism behave like neutral markers

Studies of population structure and diversity in cattle have provided insights into the origins of breeds, their history and evolution, and allow the identification of global livestock diversity hotspots, which is important for conservation of diversity. Genetic diversity, genetic relationship, population structure, and the presence of hotspots of genetic diversity among 15 European bovine breeds from five countries were assessed using 435 single nucleotide polymorphisms (SNP) markers identified in candidate genes for muscle, lipid and energy metabolism, thus providing the opportunity to compare the breed relationships obtained using putatively functional markers with previous data using neutral loci. Individuals belonging to 11 breeds tended to be clearly assigned to a single cluster when the number of pre-defined populations reached a maximum in the likelihood of the data at K=12, whereas Asturiana de los Valles, Danish Red, Simmental, and Avilena-Negra Iberica displayed a greater degree of admixture, which may be explained by their diverse ancestry. Although overall results were in agreement with those reported by studies based on neutral genetic variations, some additional breed relationship information emerged using markers in candidate functional loci, including the relationship between the Asturiana de los Valles and Piedmontese, and Danish Red and Charolais breeds. This study indicates that the analysed loci have not been main targets for selection or for adaptation processes, but also that SNP within candidate genes related with beef characteristics and performance may provide a slightly new perspective on past breeding and may also help in the development of strategies for the rational conservation of livestock diversity

Utilidad de la conformación del túnel liso antes de usar limas rotatorias endodónticas de níquel-titanio

Introducción: para prevenir la fractura de instrumentos endodonticos actualmente se siguen investigando materiales, técnicas y diseños los cuales buscan reducir su incidencia. La conformación de túnel liso (Glide Path) se ha propuesto con este fin, sin embargo su utilidad ha sido controvertida. Objetivo: comprobar teóricamente mediante la utilización de un análisis de elementos finitos, la utilidad de la conformación de túnel liso, antes de la utilización de limas rotatorias endodonticas de níquel-titanio. Métodos: se realizó una simulación numérica mediante un análisis de elementos finitos, para lo cual se construyeron modelos matemáticos de las limas rotatorias de níquel-titanio S1 y S2 de la serie Protaper®. Con el software Simulation multyphisics de Autodesk® se programaron las propiedades mecánicas de las limas y un límite de falla por fractura de 1270,588 MPa. Posteriormente se aplicó el torque recomendado por el fabricante y se fijo la punta del instrumento (sin conformación de túnel liso) aplicando allí restricciones en todos los grados de libertad.Para simular la realización de la conformación de túnel liso, se aplicaron restricciones en todos los grados de libertad a una determinada distancia de la punta del instrumento, simulando de esta forma que la punta del instrumento permanecía libre. Resultados: al fijar la punta de las limas, los esfuerzos máximos fueron 1545,77 MPa para la S1 y 1306,47 MPa para la S2, observando fractura de los instrumentos. Al fijar las limas a distancia de la punta no se observó fractura. Conclusiones: se demostró teóricamente que al impedir que se atrapen la punta de las limas, se previene su fractura y que dicho atrapamiento se evita con una conformación de túnel liso, por lo que se concluye que este procedimiento es útil para prevenir la fractura de los instrumentos rotatorios de níquel-titanio