Safe DreamerV3: Safe Reinforcement Learning with World Models

The widespread application of Reinforcement Learning (RL) in real-world situations is yet to come to fruition, largely as a result of its failure to satisfy the essential safety demands of such systems. Existing safe reinforcement learning (SafeRL) methods, employing cost functions to enhance safety, fail to achieve zero-cost in complex scenarios, including vision-only tasks, even with comprehensive data sampling and training. To address this, we introduce Safe DreamerV3, a novel algorithm that integrates both Lagrangian-based and planning-based methods within a world model. Our methodology represents a significant advancement in SafeRL as the first algorithm to achieve nearly zero-cost in both low-dimensional and vision-only tasks within the Safety-Gymnasium benchmark. Our project website can be found in: https://sites.google.com/view/safedreamerv3

HL-DPoS: An Enhanced Anti-Long-Range Attack DPoS Algorithm

The consensus algorithm is crucial in blockchain for ensuring the validity and security of transactions across the decentralized network. However, achieving consensus among nodes and packaging blocks in blockchain networks is a complex task that requires efficient and secure consensus algorithms. The DPoS consensus algorithm has emerged as a popular choice due to its fast transaction processing and high throughput. Despite these advantages, the algorithm still suffers from weaknesses such as centralization and vulnerability to long-range attacks, which can compromise the integrity of the blockchain network. To combat these problems, we developed an Enhanced Anti-Long-Range Attack DPoS algorithm (HL-DPoS). First, we split nodes into pieces to reduce centralization issues while giving witness nodes the power to report and benefit from malicious node's reports, maintaining high efficiency and high security. Second, we propose a validation method in HL-DPoS that compares consensuses transactions with the longest chain to detect long-range attacks. Algorithm analysis and simulation experiment results demonstrate that our HL-DPoS consensus algorithm improves security while achieving better consensus performance

Early-initiated childhood reading for pleasure : associations with better cognitive performance, mental well-being and brain structure in young adolescence

Childhood is a crucial neurodevelopmental period. We investigated whether childhood reading for pleasure (RfP) was related to young adolescent assessments of cognition, mental health, and brain structure. We conducted a cross-sectional and longitudinal study in a large-scale US national cohort (10 000 + young adolescents), using the well-established linear mixed model and structural equation methods for twin study, longitudinal and mediation analyses. A 2-sample Mendelian randomization (MR) analysis for potential causal inference was also performed. Important factors including socio-economic status were controlled. Early-initiated long-standing childhood RfP (early RfP) was highly positively correlated with performance on cognitive tests and significantly negatively correlated with mental health problem scores of young adolescents. These participants with higher early RfP scores exhibited moderately larger total brain cortical areas and volumes, with increased regions including the temporal, frontal, insula, supramarginal; left angular, para-hippocampal; right middle-occipital, anterior-cingulate, orbital areas; and subcortical ventral-diencephalon and thalamus. These brain structures were significantly related to their cognitive and mental health scores, and displayed significant mediation effects. Early RfP was longitudinally associated with higher crystallized cognition and lower attention symptoms at follow-up. Approximately 12 h/week of youth regular RfP was cognitively optimal. We further observed a moderately significant heritability of early RfP, with considerable contribution from environments. MR analysis revealed beneficial causal associations of early RfP with adult cognitive performance and left superior temporal structure. These findings, for the first time, revealed the important relationships of early RfP with subsequent brain and cognitive development and mental well-being

Halophilic archaea cultivated from surface sterilized middle-late eocene rock salt are polyploid

Peer reviewe

Tembusu Virus in Ducks, China

In China in 2010, a disease outbreak in egg-laying ducks was associated with a flavivirus. The virus was isolated and partially sequenced. The isolate exhibited 87%–91% identity with strains of Tembusu virus, a mosquito-borne flavivirus of the Ntaya virus group. These findings demonstrate emergence of Tembusu virus in ducks

Petroleum rock mechanics: An area worthy of focus in geo-energy research

Rock mechanics is a discipline that studies the stress, strain, failure, stability, and reinforcement of rocks under the action of external factors (such as load, fluid flow, and temperature changes). It is not only a branch of mechanics but also an interdisciplinary engineering subject. This discipline requires knowledge of applied mathematics, solid mechanics, fluid mechanics, geology, soil mechanics, and civil engineering, etc., and the main purpose is to solve engineering problems that arise from anthropogenic or natural processes concerning rock physics. Petroleum, a complex mixture of hydrocarbons that occurs in subsurface rocks in liquid, gaseous, or solid form, includes oil, natural gas, and the viscoelastic solid bitumen. Literally, “petroleum” means “rock oil” from Latin, in which the word “petra” means “rock” or “stone” while “oleum” corresponds to “oil”.The upstream of the petroleum industry mainly includes the processes of petroleum geophysical prospecting, drilling & completion, fracturing, injection & production, and storage. Each of the abovementioned phases is directly related to rock mechanics, and for some of these stages, the success of the project directly depends on the mechanical behavior of the subsurface rocks.·  In the stage of petroleum geophysical exploration, it is necessary to ascertain the intrinsic correlation between petrophysical properties and field parameters related to geophysical exploration methods, e.g., how rock elastic moduli will affect wave propagation during acoustic porosity logging, which is conducive to improving the accuracy of reservoir identification and explaining the oil and gas occurrence states as well as physical parameters of the reservoir.·  In the drilling and completion stage, rock mechanics is the main theoretical basis to ensure wellbore stability and prevent sand production or casing damage. At this stage, it is necessary to establish mechanical models through analytical or numerical methods to reveal the mechanical mechanisms of wellbore instability, sand production, and casing damage for various well types such as vertical, inclined, horizontal, and lateral wells. Consequently, controlled measurements can be made to ensure the stability and integrity of the borehole.·  Fracturing is a key technology for the efficient development of low-permeability oil and gas reservoirs. Based on the theories of rock fracture mechanics and fluid mechanics, the evaluation metric of rock fracability can be proposed, the crack propagation pattern of complex reservoir rocks during hydraulic fracturing can be revealed, and the process and parameters of hydraulic fracturing can be optimized based on computer simulation of hydraulic fracturing.·  Fluid injection and production can usually be regarded as a pure fluid transport problem in reservoir engineering contexts. But the reservoir rock is, after all, an elastoplastic material rather than a rigid body. Therefore, in order to accurately predict oil and gas production and optimize injection and production protocols, reservoir thermo-hydromechanical coupling theory has been incorporated into reservoir simulation and geo-stress evolution analysis. By formulating different rock constitutive models, fluid transport models, and multi-physics coupling algorithms, integrated simulations of reservoir fluid pressure and solid stress fields can be achieved.·  Large-scale underground gas storage is an important measure to ensure the safe production of oil and gas. In the stage of site selection and operating parameter design, it is necessary to study the sealing efficiency of the caprock and the stability of the nearby faults based on rock mechanics and fluid-solid coupling theories, so as to determine the safety window for all the operating parameters during gas storage.·  In the design of salt cavern gas storage projects, rock mechanics analysis is necessary for salt cavern stability evaluation, injection pressure optimization, and geological disasters prevention, such as land subsidence and induced seismicity. In addition to the issues mentioned above, natural gas hydrate extraction, enhanced heavy oil recovery, and shale gas/oil reservoir development also involve complex thermal-hydraulic-mechanical-chemical coupling mechanisms.Nowadays, the development of oil and gas reservoirs is getting deeper and deeper. For example, some wells in the Tarim Oilfield in Xinjiang, have been drilled more than 8,000 meters in depth. At the same time, rock mechanics is playing an increasingly important role in the oil and gas industry with the increasing development of unconventional oil and gas reservoirs. In the coming period, the research of petroleum rock mechanics will focus on:·  Rock mechanical properties and behaviors under high temperature and high pressure and their influences on reservoir productivity;·  The propagation and control of hydraulic fractures in complex reservoirs, as well as new and efficient fracturing methods for shale oil and gas reservoirs;·  Improved reservoir rock thermal-hydraulic-mechanical chemical multi-physics coupling algorithms;·  High temperature and high pressure physical experiments of reservoir rock under multi-physics conditions;·  Accurate and efficient computational algorithms and simulator development for multi-physics coupling problems.Certainly, with the in-depth intersection and integration of various related disciplines, 3D printing technology, artificial intelligence algorithm and other technologies have been introduced into petroleum rock mechanics, and numerous new research directions are emerging.The papers published in this virtual special issue are closely related to petroleum rock mechanics and have important significance in both theoretical and practical aspects. In these 16 articles, the research on the modeling and simulation of permeability variation is mainline. Coupled multi-scale and multi-physics characterization, as well as the related simulation methods are the focus of attention. The purpose of the included researches is to discover and explain the mechanisms governing the exploitation of geological resources and ultimately provide guidance for engineering practice.We hope that while reading and citing these papers, colleagues will think profoundly and deepen the research in this area, and jointly promote the development of petroleum rock mechanics.Cited as: Yang, C., Liu, J. Petroleum rock mechanics: An area worthy of focus in geo-energy research. Advances in Geo-Energy Research, 2021, 5(4): 351-352, doi: 10.46690/ager.2021.04.01Contributions to the virtual special issue-listing of articles arranged as follows:Andhumoudine, A. B., Nie, X., Zhou, Q., et al. Investigation of coal elastic properties based on digital core technology and finite element method. Advances in Geo-Energy Research, 2021, 5(1): 53-63.Anyim, K., Gan, Q. Fault zone exploitation in geothermal reservoirs: Production optimization, permeability evolution and induced seismicity. Advances in Geo-Energy Research, 2020, 4(1): 1-12.Chai, Y., Yin, S. 3D displacement discontinuity analysis of in-situ stress perturbation near a weak fault. Advances in Geo-Energy Research, 2021, 5(3): 286-296.Chen, S., Ding, B., Gong, L., et al. Comparison of multi-field coupling numerical simulation in hot dry rock thermal exploitation of enhanced geothermal systems. Advances in Geo-Energy Research, 2019, 3(4): 396-409.Faraji, M., Rezagholilou, A., Ghanavati, M., et al. Breakouts derived from image logs aid the estimation of maximum horizontal stress: A case study from Perth Basin, Western Australia. Advances in Geo-Energy Research, 2021, 5(1): 8-24.Jia, D., Qiu, Y., Li, C, et al. Propagation of pressure drop in coalbed methane reservoir during drainage stage. Advances in Geo-Energy Research, 2019, 3(4): 387-395.Lei, G., Liao, Q., Chen, W., et al. Stress dependent gas-water relative permeability in gas hydrates: A theoretical model. Advances in Geo-Energy Research, 2020, 4(3): 326-338.Li, J., Yu, T., Liang, X., et al. Insights on the gas permeability change in porous shale. Advances in Geo-Energy Research, 2017, 1(2): 69-73.Li, L., Liang, W., Lian, H., et al. Compressed air energy storage: characteristics, basic principles, and geological considerations. Advances in Geo-Energy Research, 2018, 2(2): 135-147.Liu, R., Jiang, Y., Huang, N., et al. Hydraulic properties of 3D crossed rock fractures by considering anisotropic aperture distributions. Advances in Geo-Energy Research, 2018, 2(2): 113-121.Nguyen, T.S. Thermo-Hydro-Mechanical-Chemical processes in geological disposal of radioactive waste – An example of regulatory research. Advances in Geo-Energy Research, 2018, 2(2): 173-189.Wang, F., Gong, R., Huang, Z., et al. Single-phase inflow  performance relationship in stress-sensitive reservoirs. Advances in Geo-Energy Research, 2021, 5(2): 202-211.Wei, Q., Wang, Y., Han, D., et al. Combined effects of permeability and fluid saturation on seismic wave dispersion and attenuation in partially-saturated sandstone. Advances in Geo-Energy Research, 2021, 5(2): 181-190.Yang, Y., He, Y., Zheng, Q. An analysis of the key safety technologies for natural gas hydrate exploitation. Advances in Geo-Energy Research, 2017, 1(2): 100-104.Ye, D., Liu, G., Gao, F., et al. A multi-field coupling model of gas flow in fractured coal seam. Advances in Geo-Energy Research, 2021, 5(1): 104-118.Zhang, T., Li, Z., Adenutsi, C.D., et al. A new model for calculating permeability of natural fractures in dual-porosity reservoir. Advances in Geo-Energy Research, 2017, 1(2): 86-92.

Evaluation by hierarchical clustering of multiple cytokine expression after phytohemagglutinin stimulation

The hierarchical clustering method has been used for exploration of gene expression and proteomic profiles; however, little research into its application in the examination of expression of multiplecytokine/chemokine responses to stimuli has been reported. Thus, little progress has been made on how phytohemagglutinin(PHA) affects cytokine expression profiling on a large scale in the human hematological system. To investigate the characteristic expression pattern under PHA stimulation, Luminex, a multiplex bead-based suspension array, was performed. The data set collected from human peripheral blood mononuclear cells (PBMC) was analyzed using the hierarchical clustering method. It was revealed that two specific chemokines (CCL3 andCCL4) underwent significantly greater quantitative changes during induction of expression than other tested cytokines/chemokines after PHA stimulation. This result indicates that hierarchical clustering is a useful tool for detecting fine patterns during exploration of biological data, and that it can play an important role in comparative studies