Predicting new mineral occurrences and planetary analog environments via mineral association analysis

The locations of minerals and mineral-forming environments, despite being of great scientific importance and economic interest, are often difficult to predict due to the complex nature of natural systems. In this work, we embrace the complexity and inherent "messiness" of our planet's intertwined geological, chemical, and biological systems by employing machine learning to characterize patterns embedded in the multidimensionality of mineral occurrence and associations. These patterns are a product of, and therefore offer insight into, the Earth's dynamic evolutionary history. Mineral association analysis quantifies high-dimensional multicorrelations in mineral localities across the globe, enabling the identification of previously unknown mineral occurrences, as well as mineral assemblages and their associated paragenetic modes. In this study, we have predicted (i) the previously unknown mineral inventory of the Mars analogue site, Tecopa Basin, (ii) new locations of uranium minerals, particularly those important to understanding the oxidation-hydration history of uraninite, (iii) new deposits of critical minerals, specifically rare earth element (REE)- and Li-bearing phases, and (iv) changes in mineralization and mineral associations through deep time, including a discussion of possible biases in mineralogical data and sampling; furthermore, we have (v) tested and confirmed several of these mineral occurrence predictions in nature, thereby providing ground truth of the predictive method. Mineral association analysis is a predictive method that will enhance our understanding of mineralization and mineralizing environments on Earth, across our solar system, and through deep time.

Global earth mineral inventory: A data legacy

Minerals contain important clues to understanding the complex geologic history of Earth and other planetary bodies. Therefore, geologists have been collecting mineral samples and compiling data about these samples for centuries. These data have been used to better understand the movement of continental plates, the oxidation of Earth's atmosphere and the water regime of ancient martian landscapes. Datasets found at 'RRUFF.info/Evolution' and 'mindat.org' have documented a wealth of mineral occurrences around the world. One of the main goals in geoinformatics has been to facilitate discovery by creating and merging datasets from various scientific fields and using statistical methods and visualization tools to inspire and test hypotheses applicable to modelling Earth's past environments. To help achieve this goal, we have compiled physical, chemical and geological properties of minerals and linked them to the above-mentioned mineral occurrence datasets. As a part of the Deep Time Data Infrastructure, funded by the W.M. Keck Foundation, with significant support from the Deep Carbon Observatory (DCO) and the A.P. Sloan Foundation, GEMI ('Global Earth Mineral Inventory') was developed from the need of researchers to have all of the required mineral data visible in a single portal, connected by a robust, yet easy to understand schema. Our data legacy integrates these resources into a digestible format for exploration and analysis and has allowed researchers to gain valuable insights from mineralogical data. GEMI can be considered a network, with every node representing some feature of the datasets, for example, a node can represent geological parameters like colour, hardness or lustre. Exploring subnetworks gives the researcher a specific view of the data required for the task at hand. GEMI is accessible through the DCO Data Portal (https://dx.deepcarbon.net/11121/6200-6954-6634-8243-CC). We describe our efforts in compiling GEMI, the Data Policies for usage and sharing, and the evaluation metrics for this data legacy.

Rat serum albumin synthesis in variant rat hepatoma cells

Variant subclones of the rat hepatoma cell line FU5-5 have been isolated that are altered in their production of rat serum albumin. Three of these variants, isolated in a random screening, have been categorized as high, intermediate, and low producers. They secrete albumin into the culture medium at different rates: 16, 1.7, and 0.3 microgram/mg cell protein/48 h. A fourth variant, isolated on the basis of altered morphology, secretes no detectable albumin. Unlike the albumin-producing variants, this null variant is also deficient in the level and inducibility of tyrosine aminotransferase activity. Albumin biosynthesis as determined in pulse-labeling experiments is affected similarly in the four variants, yielding albumin synthetic rates of 0.24, 0.035, 0.006, and less than 0.002% of total protein synthesis. The translatable albumin messenger RNA content in these variants was measured using a rabbit reticulocyte lysate system. The null variant contains no detectable mRNA, and the three quantitative variants contain levels of translatable albumin messenger RNA corresponding to 0.07, 0.03, and 0.005% of total stimulated polypeptide synthesis. The highest producing variant contains less translatable albumin mRNA than expected on the basis of cellular biosynthetic measurements, suggesting a translation efficiency difference in this clone. Cell hybrids constructed by fusing the high-producing clone and the null variant produce little or no albumin. This extinction indicates that the null variant contains a diffusible regulatory factor capable of decreasing albumin gene expression. The relatively stable and discrete heritable phenotypic changes exhibited by these clones may serve as a model for similar changes that occur during hepatic differentiation.

Immortalization of normal liver functions in cell culture: rat hepatocyte-hepatoma cell hybrids expressing ornithine carbamoyltransferase activity

Normal rat hepatocytes have been fused with highly differentiated rat hepatoma cells. Some of the hybrids express a physiologically significant level of activity of the urea cycle enzyme ornithine carbamoyltransferase (OCT), a liver-specific function not found in the hepatoma cells. These hybrids have 10% of the adult rat liver OCT specific activity, incorporate 3H-ornithine into protein arginine, and can be selectively grown in arginine-free medium supplemented with ornithine. Somatic cell hybridization of normal differentiated cells with highly differentiated neoplastic cells of the same tissue type may be useful as a general method for obtaining permanent cell lines with new tissue-specific phenotypes.