Linear programming applied to dairy cattle selection

Paper 1 outlines a generalization to Hill\u27s equations for predicting response to selection. Equations are developed that account for multiple stage selection in either or both sexes and the flow of genes for animals selected at later stages. The asymptotic response to a single cycle of selection is shown to agree with classical selection theory. The equations applied to a dairy progeny testing scheme representative of an artificial insemination organization in the USA. The predicted asymptotic rates to a single cycle of selection were overestimated by 6% and the cumulative response to continuous selection over 20 years was overestimated by 8% when single stage male selection model was compared to two stage selection model;A linear programming model that accounts for the economic consequences of response to selection to the producer enterprise over a given planning horizon is described in Paper 2. A procedure is given in detail for defining upper lower bound constraints on variables that are correlated in the linear programming model. The optimal response to selection per year for the production traits was closest to their maximums achievable from a gene-flow model. Of all the non-production traits, days open had the greatest proportion of its maximum achievable from a gene-flow model. The linear programming model was used to compute relative economic weights (REV). The REVs for milk, fat, and protein production were considerably larger than the REVs for the non-production traits for all planning horizons. Somatic cell score had the largest REVs of the non-production traits in all planning horizons;In the third paper multiple-trait REML was used to estimate the heritabilities and the genetic and phenotypic correlations for 48- and 72-mo herd life from sire models incorporating sire relationships. Two traits were defined for 48- and 72-mo herd life, true herd life (THL) and functional herd life (FHL), which were adjusted for milk production prior to culling. The genetic correlations were used to compute weights for indirect prediction of true and functional herd-life PTA from linear-type traits PTA. (Abstract shortened by UMI.

Influencia de las variaciones de la densidad en la cobertera de los cinturones de pliegues y cabalgamientos: aportación de la modelización analógica en centrifugadora

We present an innovative centrifuge analogue modelling approach to evaluate the influence of density contrast on structure location and vergence affecting thin-skinned compressional settings. Our natural prototype involves a detached foreland basin characterized by a basal ductile evaporitic décollement overlain by a brittle-like cover comprising a set of rock density variations. The experimental programme included gravity spreading and shortening characterized by density contrast up to 0.5 gr/cm3. Density contrast boundaries were designed perpendicular to the shortening except for one case, where it was parallel. Under no horizontal stress conditions, i.e. the tectonically quiescence context, just the centrifuge force (up to almost 900g), the cover depicts a syncline-anticline structure were the inflexion point was localized along the density contrast boundary. Moreover, wavelength and amplitude increased following the density contrast rise. In compression, density contrast boundaries perpendicular to the shortening direction controlled the vergence of the developed structuresSe presenta un estudio basado en la modelización analógica en centrifugadora que analiza la influencia que tienen las variaciones laterales de densidad de las rocas en la localización y vergencia de las estructuras afectadas por una tectónica de piel fina en contextos compresivos. El prototipo natural esta constituido por una cuenca de antepaís cabalgante a favor de un nivel de despegue dúctil sobre el cual se apoya una cobertera frágil caracterizada por variaciones laterales de la densidad. El programa experimental incluye experimentos en ausencia de esfuerzos horizontales y compresivos donde los contrastes de densidad varían por debajo de 0,5 gr/cm3. Los límites entre dominios con diferente densidad son perpendiculares al acortamiento salvo en un caso donde es paralelo. En ausencia de esfuerzos horizontales, aplicando la fuerza centrífuga (hasta 900g) se desarrolla una estructura sinclinal-anticlinal cuyo punto de inflexión coincide con el límite entre diferentes densidades y cuya longitud de onda y amplitud aumentan a medida que aumenta el contraste de densidad. En contextos compresivos, los contrastes de densidad localizados perpendicularmente al acortamiento controlan la vergencia de las estructura

Influence of décollement-cover thickness variations in fold-and-thrust belts: Insights from centrifuge analog modeling

Centrifuge analog modeling incorporating thickness variations of décollement and overlying sedimentary cover is used to study thrust-wedge evolution on salt-detached contractional systems involving tapered sedimentary cover. From simpler, layer-cake to 3D tapered décollement-cover sequences, our models constrain wedge evolution: a more advanced front, where the cover is thicker, promotes differential frontal translation and triggers vertical axis rotation of several hinterland anticlines which appear towards the thinner cover area. In all cases, the décollement level is strongly sheared and tends to migrate laterally toward the thinner cover areas. Models are compared with previous analog models under normal gravity and the natural example of the South Pyrenean Central salient. All in all, we conclude that a 3D tapered décollement-cover basin architecture, as a sole factor, can determine the formation of a thrust salient formed by increasing structural curvature (progressive arc)

The Patos-Pernambuco shear system of NE Brazil: Partitioned intracontinental transcurrent deformation revealed by enhanced aeromagnetic data

The Neoproterozoic-Cambrian (Brasiliano) intracontinental Patos-Pernambuco shear system is developed in Archean to Neoproterozoic crust, reactivating rift margins N of the São Francisco Craton. We here use enhanced aeromagnetic images to reveal internal details of the broad E-W dextral Patos and Pernambuco shear zones, the intervening Central (Transversal) Domain and the adjacent Northern Domain. We estimate shear strains up to 50–60 and a total of ca. 350 and 200 km dextral displacement for the Patos and Pernambuco shear zones, respectively. Deflection of foliations, fold axial surfaces and plutons as well as internal S-C fabrics and asymmetric folds within these large shear zones confirm dextral displacement. However, the dominant population of NE-trending shear zones in the Central Domain, by many considered dextral, are here confirmed to be sinistral and thereby elongating this domain. The Northern Domain behaved differently, hence large-scale Ediacaran strain partitioning in the region is suggested, where different blocks experienced different deformation between major simple-shear dominated shear zones. We show how much more structural information can now be obtained from enhanced aeromagnetic data than from field mapping alone; aeromagnetic interpretations, nevertheless, still draw on analysis techniques epitomized by John Ramsay.publishedVersio

Marine Genetic Resources in Areas Beyond National Jurisdiction: Promoting Marine Scientific Research and Enabling Equitable Benefit Sharing

Growing human activity in areas beyond national jurisdiction (ABNJ) is driving increasing impacts on the biodiversity of this vast area of the ocean. As a result, the United Nations General Assembly committed to convening a series of intergovernmental conferences (IGCs) to develop an international legally-binding instrument (ILBI) for the conservation and sustainable use of marine biological diversity of ABNJ [the biodiversity beyond national jurisdiction (BBNJ) agreement] under the United Nations Convention on the Law of the Sea. The BBNJ agreement includes consideration of marine genetic resources (MGR) in ABNJ, including how to share benefits and promote marine scientific research whilst building capacity of developing states in science and technology. Three IGCs have been completed to date with the fourth delayed by the Covid pandemic. This delay has allowed a series of informal dialogues to take place between state parties, which have highlighted a number of areas related to MGR and benefit sharing that require technical guidance from ocean experts. These include: guiding principles on the access and use of MGR from ABNJ; the sharing of knowledge arising from research on MGR in ABNJ; and capacity building and technology transfer for developing states. In this paper, we explain what MGR are, the methods required to collect, study and archive them, including data arising from scientific investigation. We also explore the practical requirements of access by developing countries to scientific cruises, including the sharing of data, as well as participation in research and development on shore whilst promoting rather than hindering marine scientific research. We outline existing infrastructure and shared resources that facilitate access, research, development, and benefit sharing of MGR from ABNJ; and discuss existing gaps. We examine international capacity development and technology transfer schemes that might facilitate or complement non-monetary benefit sharing activities. We end the paper by highlighting what the ILBI can achieve in terms of access, utilization, and benefit sharing of MGR and how we might future-proof the BBNJ Agreement with respect to developments in science and technology

Optimal cow replacement on New Zealand seasonal supply dairy farms : a thesis presented in partial fulfilment of the requirements for a Mastrate [sic] degree of Agricultural Science in Animal Science at Massey University

An intraherd best linear unbiased prediction (BLUP) model for predicting the future milkfat production of individual cows was developed. A major advantage of the BLUP technique was to enable prediction of the future milkfat production of freshening heifers, since relationships between animals were included in the model. These predictions of future performance were incorporated, along with various costs and revenues Qf production in New Zealand and calving date, into a model to arrive at an expected net revenue for each individual cow. Three models to rank cows on future profitability were developed and evaluated. Two models utilised dynamic programming procedures. One model estimated the annualised present value of the net returns of each cow and her replacement up to a predetermined planning horizon. The second model used the same criterion, but also a11owed optimal replacement to occur in future seasons. The third model utilised replacement model evaluation techniques and estimated the annualised present value of the net returns based on the remaining economic lifespan of individual cows. The models were tested over a large number of different situations. The effects of changes in the different economic parameters are discussed and the behaviour of each model is documented. The parameters directly associated with the cost of replacement had the greatest effect on the annual present value's (APV) of individual cows. The optimal rankings were affected by the price of the heifer replacement and the price of manufacturing beef, whereas milkfat price played an insignificant role. Varying the price of manufacturing beef and the price of the heifer replacement simultaneously had only a small effect on the ranking of the cows. The parameters such as interest rate and planning horizon also affected the APVs produced by the dynamic models. Increasing the planning horizon post 10 yeors coused o reduction in the voriotion between the APVs. It was concluded that the dynamic programming model which allowed optimal replacement in future seasons provided the best system for ranking cows on expected future income

Gold associated with Neoarchean alkaline intrusion, Lac Bachelor, Abitibi, Canada

International audienceRecent alkaline intrusion-related gold deposits have been recognized worldwide (e.g. Cripple Creek, Ladolam). Similar Neoarchean deposits are now recognized in the Canadian Superior Province but their metallogeny is still misunderstood; the Lac Bachelor gold deposit is a key example. It is located within the Desmaraisville basin, a "Timiskaming-type" basin in the Abitibi Greenstone Belt Where it is hosted by a volcano-sedimentary assemblage, mafic and felsic intrusions, and associated with regional NE-SW oblique-slip faults. Gold mineralization is located on the margin of the O'Brien stock, a polyphase alkaline quartz-syenite body which intrudes andesite and tuff. It displays porphyritic and equigranular textures. Injections of aplitic dykes occurred in late events. The O'Brien stock is mainly composed of Na-and K-feldspars, quartz, and mafic minerals. Purple fluorite is present, both disseminated in the syenite and in quartz-fluorite-pyrite veins that appears as comagmatic. The Lac Bachelor gold deposit is characterized by several mineralized zones among which the Main zone (ZP) and the B zone (ZB) are the most economically important. A porphyry-style mineralization is present at the stock margin with quartz, quartz-magnetite, quart-fluorite, and pyrite stockwork. Subhorizontal quartz-fluorite veins extend into the host rocks proximal to the stock. The Main and B zones are mainly localized in tuffs at the edges of the pluton and follow pre-existing discontinuities. Gold occurs in association with disseminated pyrite, magnetite, haematite, and rare chalcopyrite and pyrrhotite. In the ZP and lesser in the ZB, the magnetite is oxidized into haematite. Gold is present in highly altered (haematite-carbonate) zones associated with disseminated pyrite. The ZB is less haematized than the ZP, which is consistent with the timing: structural relations between these zones suggest that the ZB was formed first and the ZP occurred after. The hydrothermal event is clearly related to the intrusion of the O'Brien syenite. However, fluids appear to have followed pre-existing discontinuities that focused mineralization. Results illustrate the complementary roles of magmatic and structural controls during the mineralization processes