Permeability Prediction and Diagenesis in Tight Carbonates Using Machine Learning Techniques

Machine learning techniques have found their way into many problems in geoscience but have not been used significantly in the analysis of tight rocks. We present a case study testing the effectiveness of artificial neural networks and genetic algorithms for the prediction of permeability in tight carbonate rocks. The dataset consists of 130 core plugs from the Portland Formation in southern England, all of which have measurements of Klinkenberg-corrected permeability, helium porosity, characteristic pore throat diameter, and formation resistivity. Permeability has been predicted using genetic algorithms and artificial neural networks, as well as seven conventional ‘benchmark’ models with which the machine learning techniques have been compared. The genetic algorithm technique has provided a new empirical equation that fits the measured permeability better than any of the seven conventional benchmark models. However, the artificial neural network technique provided the best overall prediction method, quantified by the lowest root-mean-square error (RMSE) and highest coefficient of determination value (R2). The lowest RMSE from the conventional permeability equations was from the RGPZ equation, which predicted the test dataset with an RMSE of 0.458, while the highest RMSE came from the Berg equation, with an RMSE of 2.368. By comparison, the RMSE for the genetic algorithm and artificial neural network methods were 0.433 and 0.38, respectively. We attribute the better performance of machine learning techniques over conventional approaches to their enhanced capability to model the connectivity of pore microstructures caused by codependent and competing diagenetic processes. We also provide a qualitative model for the poroperm characteristics of tight carbonate rocks modified by each of eight diagenetic processes. We conclude that, for tight carbonate reservoirs, both machine learning techniques predict permeability more reliably and more accurately than conventional models and may be capable of distinguishing quantitatively between pore microstructures caused by different diagenetic processes

The combined effect of environmental thermal drop and isotonicity on metabolic stores of the teleost, Oreochromis niloticus

AbstractFour experimental regimes were designed to test the capacity of the Nile tilapia Oreochromis niloticus to make use of the energy saved form osmoregulation in an isotonic medium in overcoming the Winter Stress Syndrome (WSS). Fish either pre- acclimated to freshwater or isotonic salinity at 25°C were transferred directly to freshwater or an isotonic medium (ca. 12‰) at 14°C. Fish were killed 3, 6, 24, 48, 72 and 168h after transfer. The mobilisation and use of lipids from perivisceral and muscle fat observed in the study seem to be a direct response to cold stress as well as the associated fasting, these effects were salinity dependent being lesser at the isotonic salinity. The energy needs of fish diminish in cold conditions when the salinity of the environment approaches the isotonicity. The absence of any significant changes in muscle and water content indicated that the changes of muscle lipid are true and lipid was the sole source of energy upon thermal drop. The changes of blood haemoglobin levels throughout the four experimental regimes may indicate that the isotonic medium acclimated tilapia showed less haematological disturbance due to cold stress. Results from this experimental study recommend that the pre-acclimation of the Egyptian strain of Nile tilapia, O. niloticus, to an environmental salinity close to the isotonicity may improve fish cold tolerance

Environmental isotonicity improves cold tolerance of Nile tilapia, Oreochromis niloticus, in Egypt

AbstractThe limited ability of Oreochromis niloticus to tolerate low temperatures during winter in temperate and some subtropical region, such as in Egypt, is of major economic concern. The present study was aimed to improve the cold tolerance of Nile tilapia, O. niloticus, by using the well documented phenomena of saving energy consumption for osmoregulation in isotonic medium to decrease the physiological response to cold stress at winter months and may solve the Winter Stress Syndrome (WSS) and the over-wintering problems. Fish which were either pre-acclimated to freshwater or isotonic salinity at 25°C were transferred directly to freshwater or isotonic medium (12‰) at 14°C. Fish were killed 3, 6, 24, 48, 72 and 168h after transfer. In the isotonic medium pre-acclimated fish, it is shown that the effect of cold stress on the increment of plasma glucose level was much lower than that in fresh water. From the observations of Na+, K+, Mg2+-ATPase enzyme activity we conclude that less disturbance of ionic balance caused by cold tolerance was occurred in the isotonic point water than in the fresh water. The results of the acetylcholinesterase specific activity showed that, brain enzyme was inhibited by cold stress, and that the disruption of the cholinergic function induced by cold stress was much more pronounced in fresh water pre-acclimated tilapia than in isotonic point water pre-acclimated fish. Results from this study recommend that pre-acclimation of Nile tilapia, O. niloticus, to an environmental salinity close to the isotonicity, before winter onset, may improve their cold tolerance

Validation of the Antiproliferative Effects of Organic Extracts from the Green Husk of Juglans regia L. on PC-3 Human Prostate Cancer Cells by Assessment of Apoptosis-Related Genes

With the increased use of plant-based cancer chemotherapy, exploring the antiproliferative effects of phytochemicals for anticancer drug design has gained considerable attention worldwide. This study was undertaken to investigate the effect of walnut green husk extracts on cell proliferation and to determine the possible molecular mechanism of extract-induced cell death by quantifying the expression of Bcl-2, Bax, caspases-3, and Tp53. PC-3 human prostate cancer cells. In this study, we found that green husk extracts suppressed proliferation and induced apoptosis in a dose- and time-dependent manner by modulating expression of apoptosis-related genes. This involved DNA fragmentation (determined by TUNEL assay) and significant changes in levels of mRNA and the expression of corresponding proteins. An increase in expressions of Bax, caspase-3, and tp53 genes and their corresponding proteins was detected using real-time PCR and western blot analysis in PC-3 cells treated with the green husk organic extracts. In contrast, Bcl2 expression was downregulated after exposure to the extracts. Our data suggest the presence of bioactive compound(s) in walnut green husks that are capable of killing prostate carcinoma cells by inducing apoptosis and that the husks are a candidate source of anticancer drugs

Attenuated PTH Responsiveness to Vitamin D Deficiency among Patients with Type 2 Diabetes and Chronic Hyperglycemia

Background The short and long-term relationship between hyperglycemia and PTH level among patients suffering from both diabetes type 2 and vitamin D deficiency were evaluated. Methods This was a cross sectional study performed at Dubai Diabetes Center, UAE. To demonstrate the relationship between hyperglycemia and PTH level, subjects with type 2 diabetes and vitamin D deficiency (124 adults) were divided into 4 groups based on their FPG and HbA1c levels. Results Mean vitamin D and PTH levels among subjects with HbA1c ≤ 7% (53 mmol/mol) were 14.05 ng/ml and 19.51 pg/ml respectively. On the other hand, mean vitamin D and PTH levels among subjects with HbA1c ≥ 10% (86 mmol/mol) were significantly lower at 11.77 ng/ml and 17.75 pg/ml respectively. The product of vitamin D and PTH among subjects with an HbA1c ≤ 7% (53 mmol/mol) was 250.380, compared with only 197.710 among subjects with HbA1c ≥ 10 (86 mmol/mol). Regression analysis for subjects older than 50 years shows a significant negative effect of HbA1c on the PTH level. Mean calcium level among subjects with HbA1c ≤ 7% (53 mmol/mol) was 8.80 mg/dl compared with 8.94 mg/dl when HbA1c is ≥10% (86 mmol/mol) with no statistical difference. Although high FPG was associated with a lower PTH level, such association was not statistically significant. Conclusions Chronic hyperglycemia, as assessed by A1C level, is associated with a significantly attenuated PTH responsiveness to vitamin D deficiency without a significant change in calcium level. On the other hand, there was no significant association between FPG and PTH level

Modelling spatiotemporal patterns of dubas bug infestations on date palms in northern Oman: A geographical information system case study

The aim of this paper is to demonstrate how Geographical Information System (GIS) can be used effectively to study infestations of Dubas bug (DB), 'Ommatissus lybicus' Bergevin, in date palm ('Phoenix dactylifera L.') that occurred in northern Oman during 2006-2015. The ability to produce geographical and spatiotemporal layers using GIS is expected to serve an important role in both monitoring and surveillance of DB infestation and its impact in the study area. By using of spatial analytic and geostatistical functions in ArcGIS 10.3™, data that quantified the infestation levels of DB over a 10-year period from 2006 to 2015 were used to map and model the risk of infestation spatiotemporally. We modelled the spatiotemporal risk of DB infestation by performing hotspot analysis using the Getis-Ord statistic, Gi*. Our results show that annual hotspots over the study period were mainly concentrated in the mountain plains, particularly where farms are located between gradient elevations. Furthermore, the distribution pattern varied considerably with time and space. These results demonstrated the usefulness in following annual DB infestation patterns by studying the average seasonal infestation levels and distribution of hotspots as they can facilitate the allocation of resources for the treatment of infestations and allow for more effective monitoring of its influence on date palm trees

Understanding Water Consumption in Qatar: Evidence From a Nationally Representative Survey

This paper presents an analysis of a nationally representative (n = 1,002) telephone survey conducted in Qatar on habits, perceptions, and religious attitudes related to water use. Our empirical analysis yields three main findings. When asked whether religious obligation was a reason to save water, (Formula presented.) of respondents agreed with the statement, showing it to be an important stated motive for water conservation. However, we find no statistically significant relationship between stated attitudes towards water use and actual water consumption. Second, when asked to estimate their monthly water use, participants' actual water consumption was similar to how they perceived it to be, on average, but different at the decile level. Third, certain household water usage characteristics are associated with significantly higher levels of water consumption. These include: nationality, education, number of adults in the residence, among others. 2022 Informa UK Limited, trading as Taylor & Francis Group.We thank the editor, Christos Makropoulos and three anonymous reviewers, for very helpful feedback. Additionally, we thank Alecia Cassidy for useful discussions. This paper was made possible by NPRP grant # NPRP10-0131-170-300 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors. In addition, we thank the Eng. Nasser A. Al Khuzaei, Conservation and Energy Efficiency Department, the Qatar General Electricity and Water Corporation "KAHRAMAA" for his very helpful feedback and support.Scopu