We present an analysis of local molecular clouds ( km s−1, i.e., <1.5 kpc) in the first Galactic quadrant ( and ), a pilot region of the Milky Way Imaging Scroll Painting (MWISP) CO survey. Using the ...Spectral Clustering for Interstellar Molecular Emission Segmentation algorithm to divide large molecular clouds into moderate-size ones, we determined distances to 28 molecular clouds with the background-eliminated extinction-parallax method using the Gaia DR2 parallax measurements aided by AG and AV; the distance ranges from 250 to about 1.5 kpc. These incomplete distance samples indicate a linear relationship between the distance and the radial velocity (VLSR) with a scatter of 0.16 kpc, and kinematic distances may be systematically larger for local molecular clouds. In order to investigate fundamental properties of molecular clouds, such as the total sample number, the line width, the brightness temperature, the physical area, and the mass, we decompose the spectral cube using the density-based spatial clustering of applications with noise (DBSCAN) algorithm. Post-selection criteria are imposed on DBSCAN clusters to remove the noise contamination, and we found that the separation of molecular cloud individuals is reliable based on a definition of independent consecutive structures in l-b-V space. The completeness of the local molecular cloud flux collected by the MWISP CO survey is about 80%. The physical area, A, shows a power-law distribution, dN/d , while the molecular cloud mass also follows a power-law distribution but is slightly flatter, dN/dM ∝ M−1.96 0.11.
In this paper, we investigate the effects of poroelastic properties and permeability on hydraulic fracturing in an anisotropic medium. A hybrid approach combining the EDFM (embedded discrete fracture ...model) and XFEM (extended finite element method) is proposed. Fractures are embedded into a nonconforming grid used to determine the fluid flow in a porous matrix by the mimetic finite difference method, accounting for an anisotropic permeability tensor. The stress-strain problem is solved by the extended finite element method with the same grid. The fluid flow and rock deformation as well as the fracture propagation are iteratively coupled. The proposed approach is validated against the analytical solutions for Mandel’s problem and the KDG model. A series of calculations are performed, and the obtained results are analyzed to investigate the effects of the anisotropy of permeability, that of the elastic modulus and Biot’s coefficient on the hydraulic fracturing process. It is found that the anisotropy of permeability has a significant influence on the geometrical parameter of a fracture, while the anisotropy of the elastic modulus has a dominating influence on the propagation direction of a fracture. Biot’s coefficient also has an influence on the fracture propagation kinetics.
Little is known about the changes in soil microbial phosphorus (P) cycling potential during terrestrial ecosystem management and restoration, although much research aims to enhance soil P cycling. ...Here, we used metagenomic sequencing to analyse 18 soil microbial communities at a P-deficient degraded mine site in southern China where ecological restoration was implemented using two soil ameliorants and eight plant species. Our results show that the relative abundances of key genes governing soil microbial P-cycling potential were higher at the restored site than at the unrestored site, indicating enhancement of soil P cycling following restoration. The gcd gene, encoding an enzyme that mediates inorganic P solubilization, was predominant across soil samples and was a major determinant of bioavailable soil P. We reconstructed 39 near-complete bacterial genomes harboring gcd, which represented diverse novel phosphate-solubilizing microbial taxa. Strong correlations were found between the relative abundance of these genomes and bioavailable soil P, suggesting their contributions to the enhancement of soil P cycling. Moreover, 84 mobile genetic elements were detected in the scaffolds containing gcd in the 39 genomes, providing evidence for the role of phage-related horizontal gene transfer in assisting soil microbes to acquire new metabolic potential related to P cycling.
The transportation sector has significantly contributed to greenhouse gas and air pollutant emissions. Based on the Kaya constant equation and the LMDI decomposition model, A synergistic reduction ...effect model of transportation tailpipe Environmental negative externalities emissions is constructed to adopt the inter-provincial panel data of China from 2005 to 2019. The synergistic reduction emission impact and indirect drivers between air pollution and carbon emission are analyzed. The results show that the drivers of the synergistic impact are mainly energy efficiency and industrial structure. Significant synergistic emission reduction effects exist in eastern China, western China, medium-sized transportation markets, and less developed tourism regions. Further, increasing environmental regulation can improve the synergistic reduction impact of the transportation sector's air pollutants and carbon emissions. This paper provides theoretical support for winning the battle of pollution prevention and control and achieving the "dual carbon" goal in the new era.
•A synergistic reduction effect model of air pollution and carbon emissions is established.•Air pollution reduction will increase rapidly when carbon reduction emissions increase.•Energy efficiency and industrial structure can affect the synergistic effect.•Enhance environmental regulation can improve the synergistic reduction effect.
This paper analyzes the problems in the governance of the novel coronavirus epidemic, and finds that there are still problems in collaborative governance, such as difficulties in inter-governmental ...coordination, lack of institutional guarantee, and insufficient role of social organizations. On this basis, this paper attempts to build a public crisis collaborative governance model, further explains the model, and puts forward specific action directions and countermeasures for the three types of subjects involved in this model, including government, social organizations and citizens, to participate in the public crisis collaborative governance.
Abstract
Currently, coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been reported in almost all countries globally. No effective ...therapy has been documented for COVID-19, and the role of convalescent plasma therapy is unknown. In the current study, 6 patients with COVID-19 and respiratory failure received convalescent plasma a median of 21.5 days after viral shedding was first detected, all tested negative for SARS-CoV-2 RNA within 3 days after infusion, and 5 eventually died. In conclusion, convalescent plasma treatment can end SARS-CoV-2 shedding but cannot reduce the mortality rate in critically ill patients with end-stage COVID-19, and treatment should be initiated earlier.
Six patients with coronavirus 2019 disease and respiratory failure received convalescent plasma a median of 21.5 days after first detected viral shedding, all tested negative for severe acute respiratory syndrome coronavirus 2 within 3 days after infusion, and 5 eventually died.
We present a new method of calculating distances of molecular clouds in the Galactic plane, using CO observations and the Gaia DR2 parallax and G-band extinction (AG) measurements. Due to the ...complexity of dust environments in the Galactic plane, AG contains irregular variations, which are difficult to model. To overcome this, we propose that the AG of off-cloud stars (Gaia stars around molecular clouds) can be used as a baseline to calibrate the AG of on-cloud stars (Gaia stars toward molecular clouds), which removes the AG components that are unrelated to molecular clouds. The distance is subsequently inferred from the jump point in on-cloud AG with Bayesian analysis and Markov chain Monte Carlo (MCMC) sampling. We applied this baseline subtraction method to a 100 deg2 region (209 75 ≤ l ≤ 219 75, and ) in the third Galactic quadrant, which was mapped as part of the Milky Way Imaging Scroll Painting (MWISP) project, covering three CO isotopologue lines, and derived distances and masses for 11 molecular clouds, including the Maddalena molecular cloud and Sh 2-287. The results indicate that the distance of the Perseus Arm in this region is about 2.4 kpc and molecular clouds are present in the interarm regions.
Abstract
According to the structures traced by
13
CO spectral lines within
12
CO molecular clouds (MCs), we investigate the contributions of their internal gas motions and relative motions to the ...total velocity dispersions of
12
CO MCs. Our samples of 2851
12
CO MCs harbor a total of 9556 individual
13
CO structures, among which 1848 MCs (∼65%) have one individual
13
CO structure and the other 1003 MCs (∼35%) have multiple
13
CO structures. We find that the contribution of the relative motion between
13
CO structures (
σ
13
CO
,
re
) is larger than that from their internal gas motion (
σ
13
CO
,
in
) in ∼62% of 1003 MCs in the “Multiple” regime. In addition, we find that
σ
13
CO
,
re
tends to increase with the total velocity dispersion (
σ
12
CO
,
tot
) in our samples, especially for MCs with multiple
13
CO structures. This result provides a manifestation of macroturbulence within MCs, which gradually becomes the dominant way of storing kinetic energy along with the development of MC scales.
Soaring cases of coronavirus disease (COVID-19) are pummeling the global health system. Overwhelmed health facilities have endeavored to mitigate the pandemic, but mortality of COVID-19 continues to ...increase. Here, we present a mortality risk prediction model for COVID-19 (MRPMC) that uses patients' clinical data on admission to stratify patients by mortality risk, which enables prediction of physiological deterioration and death up to 20 days in advance. This ensemble model is built using four machine learning methods including Logistic Regression, Support Vector Machine, Gradient Boosted Decision Tree, and Neural Network. We validate MRPMC in an internal validation cohort and two external validation cohorts, where it achieves an AUC of 0.9621 (95% CI: 0.9464-0.9778), 0.9760 (0.9613-0.9906), and 0.9246 (0.8763-0.9729), respectively. This model enables expeditious and accurate mortality risk stratification of patients with COVID-19, and potentially facilitates more responsive health systems that are conducive to high risk COVID-19 patients.
In 2023, the majority of the Earth witnessed its warmest boreal summer and autumn since 1850. Whether 2023 will indeed turn out to be the warmest year on record and what caused the astonishingly ...large margin of warming has become one of the hottest topics in the scientific community and is closely connected to the future development of human society. We analyzed the monthly varying global mean surface temperature (GMST) in 2023 and found that the globe, the land, and the oceans in 2023 all exhibit extraordinary warming, which is distinct from any previous year in recorded history. Based on the GMST statistical ensemble prediction model developed at the Institute of Atmospheric Physics, the GMST in 2023 is predicted to be 1.41°C ± 0.07°C, which will certainly surpass that in 2016 as the warmest year since 1850, and is approaching the 1.5°C global warming threshold. Compared to 2022, the GMST in 2023 will increase by 0.24°C, with 88% of the increment contributed by the annual variability as mostly affected by El Niño. Moreover, the multidecadal variability related to the Atlantic Multidecadal Oscillation (AMO) in 2023 also provided an important warming background for sparking the GMST rise. As a result, the GMST in 2023 is projected to be 1.15°C ± 0.07°C, with only a 0.02°C increment, if the effects of natural variability—including El Niño and the AMO—are eliminated and only the global warming trend is considered.
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