Diagenesis of Upper Cambrian Mount Simon Sandstone in the Illinois Basin - Microscale Investigation of Basinal Fluid Migration and Mass Transfer

A series of investigations were conducted to evaluate microscale evidence for basinal fluid migration in the Illinois basin during diagenesis of the Upper Cambrian Mount Simon Sandstone. Samples were examined using transmitted light and cathodoluminescence (CL) petrography, fluid inclusion analysis, and Secondary Ion Mass Spectrometry (SIMS) analysis of 18O/16O ratios and trace element compositions. Preliminary investigation of in situ laser ablation 40Ar-39Ar age dating techniques on authigenic K-feldspar over growths was also completed. Two major generations of quartz overgrowths are observed, on the basis of transmitted light and CL petrography and fluid inclusion studies. High-resolution (100 μm x 100 μm), gray-scale images of CL in authigenic quartz overgrowths were acquired using the electron microprobe. Generation 1 quartz overgrowths have low intensity, medium- to dark- gray CL and are associated with fluid inclusion homogenization temperatures (Th) of 60 - 95°C. Generation 2 quartz overgrowths have light-gray CL and are related to fluid inclusion Th of 100 - 145°C. Th decreases from the southern part of the basin towards the north. Burial temperatures estimated by stratigraphic reconstruction and thermal history modeling did not exceed 60 - 90°C, thus, passage of at least two generations of basinal fluid flow, at temperatures similar to or slightly elevated relative to burial temperature (Th = 60 - 145°C) through the Mount Simon Sandstone are indicated. Salinities of these Na-Ca-K-Mg-Cl-H2O fluids vary from 18 wt% to 25 wt% NaCl equivalent, suggesting that both diagenetic fluids were highly saline basinal brines. Ion-microprobe oxygen isotope analyses of authigenic K-feldspar and quartz reveal a south-to-north-increasing trend in δ18O values. Average K-feldspar δ18O (V-SMOW) values increase systematically from +14 ± 1‰ in the southernmost and deepest borehole samples from Illinois to +24 ± 2‰ in the northernmost outcrop samples in Wisconsin. A similar south-to-north trend was observed for quartz overgrowths (22 ± 2‰ to 28 ± 2‰). Within-sample δ18O variations of up to 9‰ are much greater than analytical precision of the ion probe. This may be, in part, the result of sampling different generations of cements, as supported by CL and fluid inclusion studies in quartz. CL zones within quartz overgrowths were analyzed to evaluate δ18O values in different generations of quartz cements. Generation 1 quartz cements have δ18O values that are equal to (within analytical precision) or greater than (up to 6.8‰ difference) generation 2 quartz cements. Overall, however, generation 1 cements are isotopically-enriched relative to generation 2 quartz cements. Constraints on fluid compositions using fluid-inclusion temperatures that were point-matched to δ18O values of quartz overgrowths containing these fluid inclusions reveal two distinct diagenetic fluids, corresponding to generation 1 (T \u3c 95°C) and generation 2 (T \u3e 95°C) fluids. the δ18O values of generation 1 fluid are about -5‰ in the southern portion of the basin and increase to ~ 0‰ in the northern part of the basin; δ18O values of generation 2 fluid increases from ~ +2‰ in the south to ~ +7‰ in the north. For the generation 1 diagenetic event (T \u3c 95°C), fluid temperatures are consistent with burial temperatures in the deeper part of the southern basin, where the fluid may have originated. Fluid temperatures in the northern part of the basin are lower than in the southern basin, but still higher than burial temperatures. Ion-microprobe studies of authigenic K-feldspar and quartz reveal that Rb, Sr, Ba, Pb, Fe, Mg, B, Ti, and Cl are present in trace amounts in authigenic K-feldspar. In quartz cements, K, Al, Fe, B, Ti, Mg, and Cl were detected. Strongly covariant relationships among Sr-Ba-Pb-Rb, Na-Mg-Ca-Cl, and K-Al in authigenic cements were attributed to their similar geochemical behaviors and incorporation modes, continuous chemical changes in the fluid during migration and cement precipitation, and the requirements of solid solution charge compensation. Concentrations of Ba, Sr, Rb, Pb, Fe, Ca, and Ce in diagenetic fluids were estimated on the basis of trace element contents in authigenic K-feldspar and distribution coefficients between sanidine and hydrothermal fluids. No correlation between fluid compositions and positions in the basin (south to north) is apparent. Total K+Na+Li+Mg+Ca concentrations are significantly higher in generation 2 quartz cement, compared to generation 1 cements; B and K are both notably enriched in generation 2. These differences suggest that later brines had a different composition. The lack of regional trends indicates more local control of the physiochemical environment on trace element concentrations in authigenic minerals, compared to their oxygen isotope of fluid inclusion compositions. Preliminary trials of in situ UV-laser probe 40Ar/39Ar dating of authigenic K-feldspar cements were largely unsuccessful in releasing Ar gas out of the overgrowths; rather, the UV-laser mostly shattered the grains, without melting them. Ar-laser step heating tests on areas ~ 50 x 50 μm in size released gas from both detrital and authigenic K-feldspar. An overwhelming amount of atmospheric air was also released from the ceramic adhesive, resulting in very large analytical errors related to air-compound corrections. Procedures need to be taken to reduce air in the ceramic adhesive during thin section preparation, if this ceramic is used to substitute for epoxies. This study demonstrates that in situ microscale ion probe analytical techniques have significant advantages over conventional analysis in obtaining oxygen isotope compositions and trace-element concentrations from very fine-grained authigenic minerals. High-resolution ion probe analysis, in concert with detailed CL petrography and fluid inclusion studies, may provide valuable geochemical constraints on low-temperature diagenesis and basinal fluid migration, revealing multiple events, regional flow directions, fluid compositions, and temperatures and possible fluid sources

Automatic seizure detection based on Machine Learning and EEG

The diagnosis and treatment of epilepsy depend on accurate seizure detection. In clinical practice, the evaluation of seizures is done by visual inspection of an electroencephalogram (EEG). it is very time­consuming and requires trained experts. Automatic seizure detection is important. Machine learning approaches are intensely being applied to this problem due to their ability to classify seizure conditions from a large amount of data, and provide pre­screened results for neurologists. This work proposes a variety of experiments with different machine­learning architectures (support vector machine SVM, K nearest neighbour KNN, random forest RF, feef forward neural network FFNN and convolutional neural network CNN) for the detection of epileptic seizures using multichannel EEG signals from the CHBT­MIT Scalp EEG Database. The best model built in this work contains a combination of a feed­forward neural network (FFNN) and a convolutional neural network (CNN). CNN input images are constructed by applying short­time Fourier transform (STFT) to electroencephalography (EEG) signals and then merged with statistical metrics into a FFNN. The best model of this project showed an outstanding performance of 98.615% accuracy, 98.737% sensitivity and 98.425% specificity. This work also includes a discussion of other exciting ideas that could lead to future research investigations

A Research on Chaos Forecast with the Capital Market Structure Model

To study the process of pricing in capital market and look for a new way for decision support in financial market, according to the mechanism of artificial neural network, Capital Market Structure Model is developed in this case due to the influence between bargainer and price of asset in market. During proof-test, result of chaos forecast under the capital market structure model shows that chaos forecast capability of the Capital Market Structure Model is good for decision support

A dynamic programming approach for generalized nearly isotonic optimization

Shape restricted statistical estimation problems have been extensively studied, with many important practical applications in signal processing, bioinformatics, and machine learning. In this paper, we propose and study a generalized nearly isotonic optimization (GNIO) model, which recovers, as special cases, many classic problems in shape constrained statistical regression, such as isotonic regression, nearly isotonic regression and unimodal regression problems. We develop an efficient and easy-to-implement dynamic programming algorithm for solving the proposed model whose recursion nature is carefully uncovered and exploited. For special $\ell_2$-GNIO problems, implementation details and the optimal ${\cal O}(n)$ running time analysis of our algorithm are discussed. Numerical experiments, including the comparison between our approach and the powerful commercial solver Gurobi for solving $\ell_1$-GNIO and $\ell_2$-GNIO problems, on both simulated and real data sets are presented to demonstrate the high efficiency and robustness of our proposed algorithm in solving large scale GNIO problems

Constructing Physical and Genomic Maps for Puccinia striiformis f. sp. tritici, the Wheat Stripe Rust Pathogen, by Comparing Its EST Sequences to the Genomic Sequence of P. graminis f. sp. tritici, the Wheat Stem Rust Pathogen

The wheat stripe rust fungus, Puccinia striiformis f. sp. tritici (Pst), does not have a known alternate host for sexual reproduction, which makes it impossible to study gene linkages through classic genetic and molecular mapping approaches. In this study, we compared 4,219 Pst expression sequence tags (ESTs) to the genomic sequence of P. graminis f. sp. tritici (Pgt), the wheat stem rust fungus, using BLAST searches. The percentages of homologous genes varied greatly among different Pst libraries with 54.51%, 51.21%, and 13.61% for the urediniospore, germinated urediniospore, and haustorial libraries, respectively, with an average of 33.92%. The 1,432 Pst genes with significant homology with Pgt sequences were grouped into physical groups corresponding to 237 Pgt supercontigs. The physical relationship was demonstrated by 12 pairs (57%), out of 21 selected Pst gene pairs, through PCR screening of a Pst BAC library. The results indicate that the Pgt genome sequence is useful in constructing Pst physical maps

Low zinc status and absorption exist in infants with jejunostomies or ileostomies which persists after intestinal repair.

There is very little data regarding trace mineral nutrition in infants with small intestinal ostomies. Here we evaluated 14 infants with jejunal or ileal ostomies to measure their zinc absorption and retention and biochemical zinc and copper status. Zinc absorption was measured using a dual-tracer stable isotope technique at two different time points when possible. The first study was conducted when the subject was receiving maximal tolerated feeds enterally while the ostomy remained in place. A second study was performed as soon as feasible after full feeds were achieved after intestinal repair. We found biochemical evidence of deficiencies of both zinc and copper in infants with small intestinal ostomies at both time points. Fractional zinc absorption with an ostomy in place was 10.9% ± 5.3%. After reanastamosis, fractional zinc absorption was 9.4% ± 5.7%. Net zinc balance was negative prior to reanastamosis. In conclusion, our data demonstrate that infants with a jejunostomy or ileostomy are at high risk for zinc and copper deficiency before and after intestinal reanastamosis. Additional supplementation, especially of zinc, should be considered during this time period