Subaerial volcanism broke mid-Proterozoic environmental stasis.

The mid-Proterozoic, spanning 1.8 to 0.8 billion years ago, is recognized as a phase of marine anoxia, low marine primary productivity (MPP), and constrained eukaryotic biodiversity. However, emerging evidence suggesting intermittent environmental disturbances and concurrent eukaryotic evolution challenges the notion of a stagnant Earth during this era. We present a study detailing volcanic activity and its consequential impact on terrestrial weathering and MPP, elucidated through the examination of 1.4-billion-year-old tropical offshore sediments. Our investigation, leveraging precise mercury (Hg) and lithium (Li) isotopic analyses, reveals the introduction of fresh rock substrates by local volcanism. This geological event initiated a transformative process, shifting the initial regolith-dominated condition in tropical lowland to a regime of enhanced chemical weathering and denudation efficiency. Notably, the heightened influx of nutrient-rich volcanic derivatives, especially phosphorus, spurred MPP rates and heightened organic carbon burial. These factors emerge as potential drivers in breaking the long-term static state of the mid-Proterozoic.

Prediction of driving stress on high-altitude expressway using driving environment features: A naturalistic driving study in Tibet.

OBJECTIVE: Owing to the harsh environment in high-altitude areas, drivers experience significant driving stress. Compared with urban roads or expressways in low-altitude areas, the driving environment in high-altitude areas has distinct features, including mountainous environments and a higher proportion of trucks and buses. This study aims to investigate the feasibility of predicting stress levels through elements in the driving environment. METHODS: Naturalistic driving tests were conducted on an expressway in Tibet. Driving stress was assessed using heart rate variability (HRV)-based indicators and classified using K-means clustering. A DeepLabv3 model was built to conduct semantic segmentation and extract environment elements from the driving scenarios recorded through a camera next to the driver's eyes. A decision tree and 4 other ensemble learning models based on decision trees were built to predict driving stress levels using the environment elements. RESULTS: Fifty-six indicators were extracted from the driving environment. Results of the prediction models demonstrate that extreme gradient boosting has the best overall performance with the F1 score (harmonic mean of the precision and recall) and G-mean (geometric mean of sensitivity and specificity) reaching 0.855 and 0.890, respectively. Indicators based on the variation rate of trucks and buses have high feature importance and exhibit positive effects on driving stress. Indicators reflecting the proportion of mountain, road, and sky features negatively affect the expected levels of driving stress. Additionally, the mountain feature demonstrates multidimensional effects, because driving stress is positively affected by indicators of the variation rate for mountain elements. CONCLUSIONS: This study validates the prediction of driving stress using environment elements in the driver's field of view and extends its application to high-altitude expressways with distinct environmental characteristics. This method provides a real-time, less intrusive, and safer method of driving stress assessment and prediction and also enhances the understanding of the environmental determinants of driving stress. The results hold promising applications, including the development of a driving state assessment and warning module as well as the identification of high-risk road sections and implementation of control measures.

Organic carbon cycling and black shale deposition: an Earth System Science perspective.

Earth has a prolonged history characterized by substantial cycling of matter and energy between multiple spheres. The production of organic carbon can be traced back to as early as ∼4.0 Ga, but the frequency and scale of organic-rich shales have varied markedly over geological time. In this paper, we discuss the organic carbon cycle and the development of black shale from the perspective of Earth System Science. We propose that black shale depositions are the results of interactions among lithospheric evolution, orbital forcing, weathering, photosynthesis and degradation. Black shales can record Earth's oxygenation process, provide petroleum and metallic mineral resources and reveal information about the driver, direction and magnitude of climate change. Future research on black shales should be expanded to encompass a more extensive and more multidimensional perspective.

[Risk Assessment Method of Non-point Source Pollution Output for Watershed Using High Resolution Data].

In recent years, non-point source pollution has become the main cause of water quality deterioration in some reservoirs in China. Taking the Panjiakou Reservoir as an example, the classical output risk model was improved by introducing a precipitation factor and terrain factor. Combined with high-resolution satellite precipitation products (GPM) and GF-6 satellite images, a high-resolution data-driven risk assessment method for non-point source pollution output was established to study the temporal and spatial distribution characteristics of non-point source pollution output risk in the Panjiakou Reservoir basin. The results showed that the non-point source pollution output risk was high in the study area in 2018. The areas with higher and highest risk of nitrogen pollution output accounted for approximately 70.6% of the total watershed area, whereas the higher risk of phosphorus pollution output accounted for approximately 21.9%. The temporal and spatial distribution characteristics of non-point source pollution output risk in the Panjiakou Reservoir basin were analyzed. It was found that the non-point source pollution output risk in the Panjiakou Reservoir basin increased first and then decreased from April to September. This was consistent with the spatial and temporal distribution of precipitation in the basin. Combined with the analysis of land use distribution characteristics, the upstream area of the basin was mainly cultivated land, whereas cities were concentrated in the downstream portion of the basin. Affected by agricultural production and human activities, the risk of non-point source pollution output was higher in these regions. In view of the temporal and spatial distribution characteristics of non-point source pollution output risk, it is necessary to formulate a reasonable agricultural fertilization method, plan the landscape layout of source-sinks, and construct vegetation buffer zones.

Temporal-spatial evolution analysis of severe traffic violations using three functional forms of models considering the diurnal variation of meteorology.

Traffic violations and crashes are inherently associated. Analysis of traffic violation frequency is a prerequisite for improvements in crash prevention and corresponding countermeasures. One of the essential works in the field of traffic violations relates to the exploration of the correlations between a certain violation type (e.g., speeding or safety belt use) and its causal factors (e.g., demographics and road types). Till now, the effects of spatiotemporal and meteorological factors on severe traffic violations, a general term for dangerous driving behaviors, have not been fully considered. Using the dataset consisting of daily severe traffic violations and meteorological conditions during 12 months in Jiangsu Province, China, violation performance functions were developed for three violation types (total violations, driving under the influence, and speeding) based on three models (Poisson regression, zero-inflated Poisson regression, and negative binomial model). The findings indicate that the negative binomial model has a better performance for traffic violation frequency estimation. Additionally, elastic analysis for three violation types relying on the negative binomial model was conducted to present the relationships between the explanatory variables and the expected violation frequency. The effects of spatiotemporal factors have revealed that the violation situations are significantly different in varying cities and the frequency of drunk driving shows a significant time instability. It is also found that rainy days will generate a decrease in the possibility of violation occurrence. With regard to temperature, a significant negative effect is found and the decrease in temperature will bring about an increase in violation frequency. Besides, traffic violation frequency is significantly increased during holidays with comfortable weather conditions. The conclusion of this study can provide insightful suggestions for the department of traffic enforcement to adjust the patrol plans according to the specified periods (weeks, months, or holidays) and weather conditions. Special rectification actions and targeted educational activities are also advised to be put forward simultaneously.

Paleoenvironmental proxies and what the Xiamaling Formation tells us about the mid-Proterozoic ocean.

The Mesoproterozoic Era (1,600-1,000 million years ago, Ma) geochemical record is sparse, but, nevertheless, critical in untangling relationships between the evolution of eukaryotic ecosystems and the evolution of Earth-surface chemistry. The ca. 1,400 Ma Xiamaling Formation has experienced only very low-grade thermal maturity and has emerged as a promising geochemical archive informing on the interplay between climate, ecosystem organization, and the chemistry of the atmosphere and oceans. Indeed, the geochemical record of portions of the Xiamaling Formation has been used to place minimum constraints on concentrations of atmospheric oxygen as well as possible influences of climate and climate change on water chemistry and sedimentation dynamics. A recent study has argued, however, that some portions of the Xiamaling Formation deposited in a highly restricted environment with only limited value as a geochemical archive. In this contribution, we fully explore these arguments as well as the underlying assumptions surrounding the use of many proxies used for paleo-environmental reconstructions. In doing so, we pay particular attention to deep-water oxygen-minimum zone environments and show that these generate unique geochemical signals that have been underappreciated. These signals, however, are compatible with the geochemical record of those parts of the Xiamaling Formation interpreted as most restricted. Overall, we conclude that the Xiamaling Formation was most likely open to the global ocean throughout its depositional history. More broadly, we show that proper paleo-environmental reconstructions require an understanding of the biogeochemical signals generated in all relevant modern analogue depositional environments. We also evaluate new data on the δ98 Mo of Xiamaling Formation shales, revealing possible unknown pathways of molybdenum sequestration into sediments and concluding, finally, that seawater at that time likely had a δ98 Mo value of about 1.1‰.

Highly fractionated chromium isotopes in Mesoproterozoic-aged shales and atmospheric oxygen.

The history of atmospheric oxygen through the Mesoproterozoic Era is uncertain, but may have played a role in the timing of major evolutionary developments among eukaryotes. Previous work using chromium isotopes in sedimentary rocks has suggested that Mesoproterozoic Era atmospheric oxygen levels were too  low in concentration (<0.1% of present-day levels (PAL)) for the expansion of eukaryotic algae and for the evolution of crown-group animals that occurred later in the Neoproterozoic Era. In contrast, our new results on chromium isotopes from Mesoproterozoic-aged sedimentary rocks from the Shennongjia Group from South China is consistent with atmospheric oxygen concentrations of >1% PAL and thus the possibility that a permissive environment existed long before the expansion of various eukaryotic clades.

Using the high-level based program interface to facilitate the large scale scientific computing.

This paper is to make further research on facilitating the large-scale scientific computing on the grid and the desktop grid platform. The related issues include the programming method, the overhead of the high-level program interface based middleware, and the data anticipate migration. The block based Gauss Jordan algorithm as a real example of large-scale scientific computing is used to evaluate those issues presented above. The results show that the high-level based program interface makes the complex scientific applications on large-scale scientific platform easier, though a little overhead is unavoidable. Also, the data anticipation migration mechanism can improve the efficiency of the platform which needs to process big data based scientific applications.