Because rainfall seeping makes losing stability of unsaturated soil slope, and arouses great loss to production and human being safety, the stability of unsaturated soil slope has been researched by many scholars rece...Because rainfall seeping makes losing stability of unsaturated soil slope, and arouses great loss to production and human being safety, the stability of unsaturated soil slope has been researched by many scholars recently. This article mainly uses the model for the prediction of shear strength with respect to soil suction, developed by Vanapalli and Fredlund to formulate rainfall seeping how to affect the stability of unsaturated soil slope. Firstly, volumetric water content of unsaturated soil slope changes with rainfall duration, and effective saturation changes with its volumetric water content. Secondly, soil volume weight changes with its volumetric water content. Thirdly, matric suction also changes with its volumetric water content. According to these causes, this article researches how much they make the contribution to the minimum safety coefficient respectively. At last, these factors roundly considered, this article gets the rule of minimum safety coefficient of unsaturated soil slope with rainfall duration that is minimum safety coefficient gradually increasing firstly, then decreasing that is composed of two sectors, first is slowly decreasing, then is fast decreasing after some value.展开更多
Cold seeps are oases for biological communities on the sea floor around hydrocarbon emission pathways.Microbial utilization of methane and other hydrocarbons yield products that fuel rich chemosynthetic communities at...Cold seeps are oases for biological communities on the sea floor around hydrocarbon emission pathways.Microbial utilization of methane and other hydrocarbons yield products that fuel rich chemosynthetic communities at these sites.One such site in the cold seep ecosystem of Krishna-Godavari basin(K-G basin)along the east coast of India,discovered in Feb 2018 at a depth of 1800 m was assessed for its bacterial diversity.The seep bacterial communities were dominated by phylum Proteobacteria(57%),Firmicutes(16%)and unclassified species belonging to the family Helicobacteriaceae.The surface sediments of the seep had maximum OTUs(operational taxonomic units)(2.27×10^(3))with a Shannon alpha diversity index of 8.06.In general,environmental parameters like total organic carbon(p<0.01),sulfate(p<0.001),sulfide(p<0.05)and methane(p<0.01)were responsible for shaping the bacterial community of the cold seep ecosystem in the K-G Basin.Environmental parameters play a significant role in changing the bacterial diversity richness between different cold seep environments in the oceans.展开更多
Bathymodiolus mussels distribute in both deep-sea cold seep and hydrothermal vent environments,whose endosymbiotic gill tissue is a prominent character for the adaptation of extreme habitats.However,few studies explor...Bathymodiolus mussels distribute in both deep-sea cold seep and hydrothermal vent environments,whose endosymbiotic gill tissue is a prominent character for the adaptation of extreme habitats.However,few studies explored the adaptation mechanisms through comparative transcriptome sequencing and analysis of different tissues between seep mussels and vent mussels.We performed the comparative transcriptome sequencing and analysis for three tissue types(gill,mantle,and adductor muscle)of Bathymodiolus mussels collected from a cold seeping site Station S 11 and the 50-km away hydrothermal field Minami-Ensei Knoll in the Okinawa Trough.Results show that gene expression patterns had distinct tissue specificity.Compared with the non-endosymbiotic tissues(mantle and adductor muscle),the significantly strengthened gene functions in endosymbiotic gill included microbial recognition(fibrinogen C domain-containing protein 1-B-like(fibcd),fibrinogen-related protein 8(frp),peptidoglycan recognition proteins(pgrp),and C-type lectin(clec)),cell apoptosis and immunity(interferon regulatory factor 1/2-like 1(ir f),cathepsin D(ctsd),caspase 2(casp 2)),and antioxidant capacity(copper/zinc superoxide dismutase(czsod),glutathione peroxidase(gpx),selenoprotein(sel)),in both seep and vent individuals.Consistent with metal accumulation,high expression levels of genes related to heavy metal detoxification(cytochrome P 450(cyp),ferritin-like(ftl),metallothionein(mt),glutathione S-transferase(gst))were also observed in gill.Moreover,to adapt to high hydrostatic pressure in the deep sea,the Kyoto Encyclopedia of Genes and Genomes(KEGG)pathways associated with cellular community were significantly enriched in all three tissues,suggesting the regulation of cell structure and cell adhesion at transcriptional level.This study obtained gene expression profiles of deep-sea mussels subsisting at cold seep and hydrothermal vent sites,which could lay foundations for comprehensive investigations of molecular basis in adaptation of deep-sea mussels to the two extreme ecosystems.展开更多
The paper deals with the urgent problem of gas-geochemical parameters in the seas and shelf transit zones based on a comparison of field studies and remote sensing data.The results of complex gas-geochemical studies o...The paper deals with the urgent problem of gas-geochemical parameters in the seas and shelf transit zones based on a comparison of field studies and remote sensing data.The results of complex gas-geochemical studies of the Daginsky gas-hydrothermal system are presented,as well as an assessment of methane emissions from the studied area.The Daginsky gas-hydrothermal system is located on the northeastern coast of Sakhalin Island,and is a unique object due to a combination of a number of factors:from zonality due to the proximity of the Okhotsk Sea and the geological structure,to the interaction of deep and surface processes manifested in the presence of biogenic and thermogenic methane,as well as mantle helium.Tectonic faults and oil and gas bearing structures of the northeastern shelf of Sakhalin,which determine the direction of natural gas flows and facilitate its migration to the surface,make a significant contribution to the gas appearance of thermal springs.The main gas is methane up to 90%,homologues of methane up to and including pentane have been established,and isolated high concentrations of helium and hydrogen,both dissolved and in the free gas of bubbles,have also been noted.The conducted isotope studies allow to speak about the complex genesis of the gas.δ^(13)C isotopic composition,ranging from−49.4‰to−60.2‰shows the dominance of biogenic methane with an admixture of thermogenic component.This is also confirmed by the presence of a fraction of mantle helium.The flow of methane into the atmosphere from the Daginsky area is 963757.5 mol/(km^(2)·day),or about 15.4 t/(km^(2)·year),which indicates the importance of this region for the regional and global carbon cycle.The dynamics of methane emissions can vary depending on various factors,such as seasonal fluctuations and geological activity,which further complicates the understanding of processes in the region.展开更多
Deep-sea cold seeps form a benthic hypoxic biome characterized by low temperatures,methane venting,and metalliferous fluid emissions.This extreme environment was dominated by high-biomass species such as clams.While m...Deep-sea cold seeps form a benthic hypoxic biome characterized by low temperatures,methane venting,and metalliferous fluid emissions.This extreme environment was dominated by high-biomass species such as clams.While most studies have focused on the symbiotic function of cold seep clams,research on the roles of their non-symbiotic functions remains limited.In this study,we conducted transcriptome analysis to examine gene expression pattern in the testis,adductor muscle(hereinafter“muscle”),and foot of Phreagena okutanii,a clam species collected from the S11 site on the western slope of the Okinawa Trough.Principal component analysis and differential expression analysis revealed that the gene expression patterns of the muscle and foot tissues were shared more similar gene expression patterns with each other than with the testis.A total of 564 co-expressed genes with transcripts per million(TPM)>10 were identified as co-expressed genes in the testis,muscle,and foot.The gene expression patterns of hemoglobin Ⅰ and Ⅱ(hb1,hb2),heat shock proteins 70 and 90(hsp70,hsp90),glutathione peroxidase(GPx),thioredoxin-2(Trx2),and ferritin(fer)for oxygen transportation,stress response and antioxidation were identified in the three tissues.In particular,4853 and 6194 differentially expressed genes(DEGs)were identified in the testis compared to the muscle and foot,respectively,significantly exceeding the 854 DEGs observed between the muscle and foot.Furthermore,DEG intersection enabled the identification of shared tissue-specific expression patterns,including genes that were upregulated in the testis relative to both the muscle and foot;those upregulated in the muscle relative to both the testis and foot,and those upregulated in the foot relative to both the testis and muscle.Antioxidant genes inhibited the production of reactive oxygen species and catalyzed their removal.The immune response gene played a key role in pathogen recognition and elimination.Energy metabolism genes enhanced energy production and accumulation,supporting adaptation to the high-sulfur and low-oxygen environments.Our study provides further insights into the gene expression pattern of bivalves in specialized deep-sea cold seep environments.展开更多
The stability of unsaturated soil slope has been the hot point recently. Especially, the seeping rainfall makes losing stability of unsaturated soil slope, and causes enormous loss to the producation and safety of oth...The stability of unsaturated soil slope has been the hot point recently. Especially, the seeping rainfall makes losing stability of unsaturated soil slope, and causes enormous loss to the producation and safety of other people. The seeping rainfall makes volumetric water content of unsaturated soil slope changing, and the volumetric water content has directly relationship with matric suction. And matric suction also has directly relationship with the stability of unsaturated soil slope. So the change of matric suction influence the stability changing, that is, safety coefficient has decided relationship with volumetric water content. The profile of dangerous volumetric water content curves of unsaturated soil slope has been obtained. If a volumetric water content curve of some unsaturated soil slope belongs to one of these dongerous curves, the unsaturated soil slope could be in danger. So this is called DVWCCP(dangerous volumetric water content curves profile). By monitoring the volumetric water content curves can obtain the stability information of some soil slope to serve producing and safety.展开更多
基金Supported bythe Heilongjiang Province Education Office Gaozhigaozhuan Research.The Project No.10555020 and Heilongjiang Province Higher Education Scientific Research Institute of Higher Education"11.5"planningissues(115c-386).
文摘Because rainfall seeping makes losing stability of unsaturated soil slope, and arouses great loss to production and human being safety, the stability of unsaturated soil slope has been researched by many scholars recently. This article mainly uses the model for the prediction of shear strength with respect to soil suction, developed by Vanapalli and Fredlund to formulate rainfall seeping how to affect the stability of unsaturated soil slope. Firstly, volumetric water content of unsaturated soil slope changes with rainfall duration, and effective saturation changes with its volumetric water content. Secondly, soil volume weight changes with its volumetric water content. Thirdly, matric suction also changes with its volumetric water content. According to these causes, this article researches how much they make the contribution to the minimum safety coefficient respectively. At last, these factors roundly considered, this article gets the rule of minimum safety coefficient of unsaturated soil slope with rainfall duration that is minimum safety coefficient gradually increasing firstly, then decreasing that is composed of two sectors, first is slowly decreasing, then is fast decreasing after some value.
文摘Cold seeps are oases for biological communities on the sea floor around hydrocarbon emission pathways.Microbial utilization of methane and other hydrocarbons yield products that fuel rich chemosynthetic communities at these sites.One such site in the cold seep ecosystem of Krishna-Godavari basin(K-G basin)along the east coast of India,discovered in Feb 2018 at a depth of 1800 m was assessed for its bacterial diversity.The seep bacterial communities were dominated by phylum Proteobacteria(57%),Firmicutes(16%)and unclassified species belonging to the family Helicobacteriaceae.The surface sediments of the seep had maximum OTUs(operational taxonomic units)(2.27×10^(3))with a Shannon alpha diversity index of 8.06.In general,environmental parameters like total organic carbon(p<0.01),sulfate(p<0.001),sulfide(p<0.05)and methane(p<0.01)were responsible for shaping the bacterial community of the cold seep ecosystem in the K-G Basin.Environmental parameters play a significant role in changing the bacterial diversity richness between different cold seep environments in the oceans.
基金Supported by the National Natural Science Foundation of China(Nos.91858208,92358301)the Laoshan Laboratory(No.LSKJ 202203500),the China Postdoctoral Science Foundation of China(No.2019M663209)the Fundamental Research Funds for the Central Universities in China(No.19lGPY100)。
文摘Bathymodiolus mussels distribute in both deep-sea cold seep and hydrothermal vent environments,whose endosymbiotic gill tissue is a prominent character for the adaptation of extreme habitats.However,few studies explored the adaptation mechanisms through comparative transcriptome sequencing and analysis of different tissues between seep mussels and vent mussels.We performed the comparative transcriptome sequencing and analysis for three tissue types(gill,mantle,and adductor muscle)of Bathymodiolus mussels collected from a cold seeping site Station S 11 and the 50-km away hydrothermal field Minami-Ensei Knoll in the Okinawa Trough.Results show that gene expression patterns had distinct tissue specificity.Compared with the non-endosymbiotic tissues(mantle and adductor muscle),the significantly strengthened gene functions in endosymbiotic gill included microbial recognition(fibrinogen C domain-containing protein 1-B-like(fibcd),fibrinogen-related protein 8(frp),peptidoglycan recognition proteins(pgrp),and C-type lectin(clec)),cell apoptosis and immunity(interferon regulatory factor 1/2-like 1(ir f),cathepsin D(ctsd),caspase 2(casp 2)),and antioxidant capacity(copper/zinc superoxide dismutase(czsod),glutathione peroxidase(gpx),selenoprotein(sel)),in both seep and vent individuals.Consistent with metal accumulation,high expression levels of genes related to heavy metal detoxification(cytochrome P 450(cyp),ferritin-like(ftl),metallothionein(mt),glutathione S-transferase(gst))were also observed in gill.Moreover,to adapt to high hydrostatic pressure in the deep sea,the Kyoto Encyclopedia of Genes and Genomes(KEGG)pathways associated with cellular community were significantly enriched in all three tissues,suggesting the regulation of cell structure and cell adhesion at transcriptional level.This study obtained gene expression profiles of deep-sea mussels subsisting at cold seep and hydrothermal vent sites,which could lay foundations for comprehensive investigations of molecular basis in adaptation of deep-sea mussels to the two extreme ecosystems.
基金funded by a grant Russian Science Foundation(No.23-77-10038,https://rscf.ru/project/23-77-10038/)partly within the framework of the state task of the POI FEB RAS(No.124022100078-7).
文摘The paper deals with the urgent problem of gas-geochemical parameters in the seas and shelf transit zones based on a comparison of field studies and remote sensing data.The results of complex gas-geochemical studies of the Daginsky gas-hydrothermal system are presented,as well as an assessment of methane emissions from the studied area.The Daginsky gas-hydrothermal system is located on the northeastern coast of Sakhalin Island,and is a unique object due to a combination of a number of factors:from zonality due to the proximity of the Okhotsk Sea and the geological structure,to the interaction of deep and surface processes manifested in the presence of biogenic and thermogenic methane,as well as mantle helium.Tectonic faults and oil and gas bearing structures of the northeastern shelf of Sakhalin,which determine the direction of natural gas flows and facilitate its migration to the surface,make a significant contribution to the gas appearance of thermal springs.The main gas is methane up to 90%,homologues of methane up to and including pentane have been established,and isolated high concentrations of helium and hydrogen,both dissolved and in the free gas of bubbles,have also been noted.The conducted isotope studies allow to speak about the complex genesis of the gas.δ^(13)C isotopic composition,ranging from−49.4‰to−60.2‰shows the dominance of biogenic methane with an admixture of thermogenic component.This is also confirmed by the presence of a fraction of mantle helium.The flow of methane into the atmosphere from the Daginsky area is 963757.5 mol/(km^(2)·day),or about 15.4 t/(km^(2)·year),which indicates the importance of this region for the regional and global carbon cycle.The dynamics of methane emissions can vary depending on various factors,such as seasonal fluctuations and geological activity,which further complicates the understanding of processes in the region.
基金The National Natural Science Foundation of China under contract Nos 91858208 and 92358301the Laoshan Laboratory under contract No.LSKJ202203500+2 种基金the China Postdoctoral Science Foundation of China under contract No.2019M663209the Fundamental Research Funds for the Central Universities in China under contract No.19lGPY100the Innovation and Entrepreneurship Training Program for College Students under contract No.202210558122.
文摘Deep-sea cold seeps form a benthic hypoxic biome characterized by low temperatures,methane venting,and metalliferous fluid emissions.This extreme environment was dominated by high-biomass species such as clams.While most studies have focused on the symbiotic function of cold seep clams,research on the roles of their non-symbiotic functions remains limited.In this study,we conducted transcriptome analysis to examine gene expression pattern in the testis,adductor muscle(hereinafter“muscle”),and foot of Phreagena okutanii,a clam species collected from the S11 site on the western slope of the Okinawa Trough.Principal component analysis and differential expression analysis revealed that the gene expression patterns of the muscle and foot tissues were shared more similar gene expression patterns with each other than with the testis.A total of 564 co-expressed genes with transcripts per million(TPM)>10 were identified as co-expressed genes in the testis,muscle,and foot.The gene expression patterns of hemoglobin Ⅰ and Ⅱ(hb1,hb2),heat shock proteins 70 and 90(hsp70,hsp90),glutathione peroxidase(GPx),thioredoxin-2(Trx2),and ferritin(fer)for oxygen transportation,stress response and antioxidation were identified in the three tissues.In particular,4853 and 6194 differentially expressed genes(DEGs)were identified in the testis compared to the muscle and foot,respectively,significantly exceeding the 854 DEGs observed between the muscle and foot.Furthermore,DEG intersection enabled the identification of shared tissue-specific expression patterns,including genes that were upregulated in the testis relative to both the muscle and foot;those upregulated in the muscle relative to both the testis and foot,and those upregulated in the foot relative to both the testis and muscle.Antioxidant genes inhibited the production of reactive oxygen species and catalyzed their removal.The immune response gene played a key role in pathogen recognition and elimination.Energy metabolism genes enhanced energy production and accumulation,supporting adaptation to the high-sulfur and low-oxygen environments.Our study provides further insights into the gene expression pattern of bivalves in specialized deep-sea cold seep environments.
文摘The stability of unsaturated soil slope has been the hot point recently. Especially, the seeping rainfall makes losing stability of unsaturated soil slope, and causes enormous loss to the producation and safety of other people. The seeping rainfall makes volumetric water content of unsaturated soil slope changing, and the volumetric water content has directly relationship with matric suction. And matric suction also has directly relationship with the stability of unsaturated soil slope. So the change of matric suction influence the stability changing, that is, safety coefficient has decided relationship with volumetric water content. The profile of dangerous volumetric water content curves of unsaturated soil slope has been obtained. If a volumetric water content curve of some unsaturated soil slope belongs to one of these dongerous curves, the unsaturated soil slope could be in danger. So this is called DVWCCP(dangerous volumetric water content curves profile). By monitoring the volumetric water content curves can obtain the stability information of some soil slope to serve producing and safety.
