Технология и техника сооружения поисково-оценочных скважин на Майском месторождении алмазов (Республика Саха (Якутия))

Объектом исследования является кимберлитовая руда на объекте "Майское". Цель работы: составление проекта на бурение поисково-оценочных скважин; геологическое изучение объекта; разработка технологии проведе-ния поисковых работ на участке; разработка управления и организации работ на объекте. В процессе проектирования проводились: выбор бурового оборудования; поверочный расчет выбранного оборудования; расчет режимных параметров; анализ вредных и опасных факторов при проведении геологоразведочных работ и меры по их предупреждению; выбор вспомогательного оборудования и организации работ; сметно-финансовый расчет.The object of the study is kimberlite ore at the Mayskoye facility. The purpose of the work: preparation of the project for the drilling of exploration and evaluation wells; geological study of the object; development of technology for prospecting works on the site; development of management and organization of works on the site. In the process of design were carried out: selection of drilling equipment; calibration calculation of the selected equipment; calculation of operating parameters; analysis of harmful and dangerous factors during exploration and measures to prevent them; selection of auxiliary equipment and organization of wo

Homozygous WNT3 Mutation Causes Tetra-Amelia in a Large Consanguineous Family

Tetra-amelia is a rare human genetic disorder characterized by complete absence of all four limbs and other anomalies. We studied a consanguineous family with four affected fetuses displaying autosomal recessive tetra-amelia and craniofacial and urogenital defects. By homozygosity mapping, the disease locus was assigned to chromosome 17q21, with a maximum multipoint LOD score of 2.9 at markers D17S931, D17S1785, D17SS1827, and D17S1868. Further fine mapping defined a critical interval of ∼8.9 Mb between D17S1299 and D17S797. We identified a homozygous nonsense mutation (Q83X) in the WNT3 gene in affected fetuses of the family. WNT3, a human homologue of the Drosophila wingless gene, encodes a member of the WNT family known to play key roles in embryonic development. The Q83X mutation truncates WNT3 at its amino terminus, suggesting that loss of function is the most likely cause of the disorder. Our findings contrast with the observation of early lethality in mice homozygous for null alleles of Wnt3. To our knowledge, this is the first report of a mutation in a WNT gene associated with a Mendelian disorder. The identification of a WNT3 mutation in tetra-amelia indicates that WNT3 is required at the earliest stages of human limb formation and for craniofacial and urogenital development