Search

Extreme climate events are becoming more frequent, with poorly understood implications for carbon sequestration by terrestrial ecosystems. A better understanding will critically depend on accurate and precise quantification of ecosystems responses to these events. Taking the 2019 US Midwest floods as a case study, we investigate current capabilities for tracking regional flux anomalies with "top‐down" inversion analyses that assimilate atmospheric CO2 observations. For this analysis, we develop a regionally nested version of the NASA Carbon Monitoring System‐Flux system for North America (CMS‐Flux‐NA) that allows high resolution atmospheric transport (0.5° × 0.625°). Relative to a 2018 baseline, we find the 2019 US Midwest growing season net carbon uptake is reduced by 11–57 TgC (3%–16%, range across assimilated CO2 data sets). These estimates are found to be consistent with independent "bottom‐up" estimates of carbon uptake based on vegetation remote sensing (15–78 TgC). We then investigate current limitations in tracking regional carbon budgets using "top‐down" methods. In a set of observing system simulation experiments, we show that the ability of atmospheric CO2 inversions to capture regional carbon flux anomalies is still limited by observational coverage gaps for both in situ and satellite observations. Future space‐based missions that allow for daily observational coverage across North America would largely mitigate these observational gaps, allowing for improved top‐down estimates of ecosystem responses to extreme climate events. Plain Language Summary: Extreme climate events, such as floods or heatwaves, can have major impacts on the carbon cycle. For example, widespread flooding in the US Midwest during 2019 delayed the planting of crops leading to reduced plant growth and carbon uptake relative to 2018. Here, we test how well this reduction in carbon uptake can be inferred from measurements of atmospheric CO2. We find that these data can identify reduced net carbon uptake to the US Midwest during the 2019 floods, but that sparse observational coverage limits our ability to quantify the anomaly in net carbon uptake. We show that expanded space‐based observations of CO2 would fill these gaps, allowing for improved estimates of interannual variations in the US CO2 budget. Key Points: Bottom‐up and top‐down methods capture reduced 2019 US Midwest carbon uptake relative to 2018Gaps in atmospheric CO2 observations drive uncertainties in top‐down estimatesNested inversion better localizes US Midwest ΔNEE relative to coarse global model [ABSTRACT FROM AUTHOR]

Autonomous sleep tracking at home has become inevitable in today’s fast-paced world. A crucial aspect of addressing sleep-related issues involves accurately classifying sleep stages. This paper introduces a novel approach PSO–XGBoost, combining particle swarm optimisation (PSO) with extreme gradient boosting (XGBoost) to enhance the XGBoost model’s performance. Our model achieves improved overall accuracy and faster convergence by leveraging PSO to fine-tune hyperparameters. Our proposed model utilises features extracted from EEG signals, spanning time, frequency, and time–frequency domains. We employed the Pz-oz signal dataset from the sleep-EDF expanded repository for experimentation. Our model achieves impressive metrics through stratified-K-fold validation on ten selected subjects: 95.4% accuracy, 95.4% F1-score, 95.4% precision, and 94.3% recall. The experiment results demonstrate the effectiveness of our technique, showcasing an average accuracy of 95%, outperforming traditional machine learning classifications. The findings revealed that the feature-shifting approach supplements the classification outcome by 3 to 4 per cent. Moreover, our findings suggest that prefrontal EEG derivations are ideal options and could open up exciting possibilities for using wearable EEG devices in sleep monitoring. The ease of obtaining EEG signals with dry electrodes on the forehead enhances the feasibility of this application. Furthermore, the proposed method demonstrates computational efficiency and holds significant value for real-time sleep classification applications.

Indian Writing English is matured from a sapling to deep rooted tree where it shelters over millions of people by exploring the writers in various branches. Among explored writers, Amit Chaudhuri is a writer in versatile. He is a poet, novelist, critic, essayist, singer and also a good musician. Amit Chaudhuri belongs to Calcutta, his works excessively explicit the impact of a particular perspective of own domain, Calcutta. Chaudhuri's first novel A Strange and Sublime Address explores the domestic values of middle class family in the city of Calcutta where the family gives more importance to traditional and cultural values of ancestral home. Chaudhuri has described the city of Calcutta in parallel fashions as City of Joy and City of Chaos. The protagonist of the novel is twelve years old boy, Sandeep and Chaudhuri has portrayed the distinct instances of domestic obsession of the characters can be observed in the novel. Hence, the present paper focuses on domestic perception of Calcutta city conceited by Amit Chaudhuri in his AStrange and Sublime Address. [ABSTRACT FROM AUTHOR]

Adding bioenergy to the U.S. energy portfolio requires long-term profitability for bioenergy producers and long-term protection of affected ecosystems. In this study, we present steps along the path toward evaluating both sides of the sustainability equation (production and environmental) for switchgrass (Panicum virgatum) using the Soil and Water Assessment Tool (SWAT). We modeled production of switchgrass and river flow using SWAT for current landscapes at a regional scale. To quantify feedstock production, we compared lowland switchgrass yields simulated by SWAT with estimates from a model based on empirical data for the eastern U.S. The two produced similar geographic patterns. Average yields reported in field trials tended to be higher than average SWAT-predicted yields, which may nevertheless be more representative of production-scale yields. As a preliminary step toward quantifying bioenergy-related changes in water quality, we evaluated flow predictions by the SWAT model for the Arkansas-White-Red river basin. We compared monthly SWAT flow predictions to USGS measurements from 86 subbasins across the region. Although agreement was good, we conducted an analysis of residuals (functional validation) seeking patterns to guide future model improvements. The analysis indicated that differences between SWAT flow predictions and field data increased in downstream subbasins and in subbasins with higher percentage of water. Together, these analyses have moved us closer to our ultimate goal of identifying areas with high economic and environmental potential for sustainable feedstock production. [ABSTRACT FROM AUTHOR]

Chromium is known to be highly toxic to biological systems. This study was designed to determine the mutagenic effects of different concentrations (0, 10, 25, 50, 100 and 200 mg/L) of hexavalent chromium on root tip cells of blackgram (Vigna mungo L. Hepper). The blackgram seeds were equi-spacially arranged in sterilized petriplates lined with filter paper and they were treated with different concentrations of chromium solution. In germination studies, the morphological growth parameters such as germination percentage, root length, shoot length fresh weight and dry weight of blackgram seedlings were decreased with increasing dose of chromium concentrations. No germination of blackgram seeds was recorded at 300mg/l chromium concentration. Chromosome aberration assay was used to determine the mitotic indices and rate of chromosome aberration in blackgram root tip cells due to chromium treatment. The results showed that the mitotic indices were complicated due to different concentrations of chromium. However, the increase in chromium concentration has led to a gradual increase in the percentage of chromosomal aberration and mitotic index. The chromosome length, absolute chromosome length and average chromosome lengths were gradually found to decrease. There was no considerable change in 2n number of chromosome with the increase in chromium concentrations. It is concluded that the hexavalent chromium has significant mutagenic effect on the root tip cells of blackgram. [ABSTRACT FROM AUTHOR]

The sugar industry is a key factor in the rural economy of our country. The enormous quantities of wastes generated by the sugar mills has led to the problems of air, water and soil pollution. The water pollution problem due to the discharge of industrial effluents is affecting greater dimension in India. These effluents irrigation not only reduced the growth and crop productivity but also polluted the soil. So, an attempt has been made to find out the effect of application of vermicompost on growth behaviour, biochemical changes and yield of greengram grown under sugar mill effluent polluted soil. The experiment studies were carried out in plastic containers filled with polluted soil mixed with vermicompost. The growth parameters like root length, shoot length, total leaf area, fresh weight and dry weight, number of fruits and yield were recorded at the time of harvest. The biochemicals like chlorophyll, protein, carotenoid, amino acid and sugar were also estimated in greengram. All the parameters increased at vermicompost mixed polluted soil when compared to control. The application of vermicompost increased the growth and yield by reducing the pollutant toxicity. [ABSTRACT FROM AUTHOR]