An investigation of the difference in seasonal precipitation forecast skills between the multiple linear regression （MLR） ensemble and the simple multimodel ensemble mean （EM） was based on the forecast quality of ...An investigation of the difference in seasonal precipitation forecast skills between the multiple linear regression （MLR） ensemble and the simple multimodel ensemble mean （EM） was based on the forecast quality of individual models. The possible causes of difference in previous studies were analyzed. In order to make the simulation capability of studied regions relatively uniform, three regions with different temporal correlation coefficients were chosen for this study. Results show the causes resulting in the incapability of the MLR approach vary among different regions. In the Nifio3.4 region, strong co-linearity within individual models is generally the main reason. However, in the high latitude region, no significant co-linearity can be found in individual models, but the abilities of single models are so poor that it makes the MLR approach inappropriate for superensemble forecasts in this region. In addition, it is important to note that the use of various score measurements could result in some discrepancies when we compare the results derived from different multimodel ensemble approaches.展开更多
This investigation aims to delineate the spatial distribution,prevalence,and diversity of antibiotic resistance genes(ARGs)within aquatic ecosystems across four coastal aquaculture zones in Hainan Province—Danzhou,Wa...This investigation aims to delineate the spatial distribution,prevalence,and diversity of antibiotic resistance genes(ARGs)within aquatic ecosystems across four coastal aquaculture zones in Hainan Province—Danzhou,Wanning,Wenchang,and Sanya.It further assesses the impact of environmental parameters on ARGs dissemination and microbial community structure.High-throughput sequencing was utilized to analyze water samples from 42 sampling sites,complemented by absolute quantitative PCR to quantify 144 ARGs variants.This approach elucidated correlations between ARGs and microbial assemblages,as well as the influence of environmental factors on these interactions.Results indicated that the number of ARGs detected per site ranged from 61 to 123,with Danzhou exhibiting 90 to 123,Wanning 74 to 123,Wenchang 68 to 122,and Sanya 61 to 109 ARGs.Notably,16 sampling points harbored over 110 ARGs.Quantitative analysis revealed ARG concentrations ranging from 16,167 to 1,784,618 copies/ng.Co-occurrence network analysis demonstrated that most ARGs were associated with MGEs,16S rRNA genes,transposons,and integrons,indicating these elements'critical role in horizontal gene transfer.Microbial community profiling identified 27,050 operational taxonomic units(OTUs)across 72 phyla,153 classes,371 orders,459 families,and 924 genera,with Proteobacteria,Bacteroidota,Actinobacteriota,Cyanobacteria,and Planctomycetota as dominant taxa.Genus-level analysis revealed significant variations in the abundance of taxa such as Cyanobium_PCC-6307,Candidatus_Actinomarina,and HIMB11 across sampling sites.Environmental parameters,including pH,dissolved oxygen(DO),specific conductance(SPC),salinity(SAL),temperature(T),and pressure(kPa),showed strong correlations with ARG distribution and microbial community composition.Region-specific colinearity networks indicated distinct relationships between microbial taxa and ARGs;notably,Danzhou and Wanning exhibited strong correlations with over 20 ARGs per genus,whereas Wenchang displayed a more complex association pattern,suggesting a multifaceted role in ARG transmission pathways.Overall,the findings suggest that environmental factors and microbial hosts significantly influence ARG prevalence in Hainan's coastal waters,with regional variations in microbial-ARG interactions,particularly in Wenchang,indicating heightened transmission risks.This study offers vital insights for sustainable aquaculture practices and informs regional regulatory strategies for aquaculture management.展开更多
The shapes of block within the rock mass have an important effect on the rock properties, so it＇s very important to evaluate the shapes of rock fragmentation and to determine the geometric characteristics distributio...The shapes of block within the rock mass have an important effect on the rock properties, so it＇s very important to evaluate the shapes of rock fragmentation and to determine the geometric characteristics distribution of the block. The previous methods to classify rock block shape are based on the assumption that a block shape is approximately orthogonal, which is acceptable in only a few rock masses. This paper proposes a new method for block shape classification using triangular diagram together with parameters of co-linearity e and volume coefficient K, which combines the shape categorization with block volume for statistical analysis. Rock block equivalent size calculation methods based on block shape is proposed and the block cumulative percentage of total volume statistical analysis is given. In order to verify this block shape classification method, three ideal rock masses with approximately orthogonal joint sets have been generated and simulated.展开更多
基金supported by the National Key Technology Research and Development Program(Grant No.2006BAC02B04)the Major State Basic Research Development Program of China(Grant No.2006CB400503)
文摘An investigation of the difference in seasonal precipitation forecast skills between the multiple linear regression （MLR） ensemble and the simple multimodel ensemble mean （EM） was based on the forecast quality of individual models. The possible causes of difference in previous studies were analyzed. In order to make the simulation capability of studied regions relatively uniform, three regions with different temporal correlation coefficients were chosen for this study. Results show the causes resulting in the incapability of the MLR approach vary among different regions. In the Nifio3.4 region, strong co-linearity within individual models is generally the main reason. However, in the high latitude region, no significant co-linearity can be found in individual models, but the abilities of single models are so poor that it makes the MLR approach inappropriate for superensemble forecasts in this region. In addition, it is important to note that the use of various score measurements could result in some discrepancies when we compare the results derived from different multimodel ensemble approaches.
文摘This investigation aims to delineate the spatial distribution,prevalence,and diversity of antibiotic resistance genes(ARGs)within aquatic ecosystems across four coastal aquaculture zones in Hainan Province—Danzhou,Wanning,Wenchang,and Sanya.It further assesses the impact of environmental parameters on ARGs dissemination and microbial community structure.High-throughput sequencing was utilized to analyze water samples from 42 sampling sites,complemented by absolute quantitative PCR to quantify 144 ARGs variants.This approach elucidated correlations between ARGs and microbial assemblages,as well as the influence of environmental factors on these interactions.Results indicated that the number of ARGs detected per site ranged from 61 to 123,with Danzhou exhibiting 90 to 123,Wanning 74 to 123,Wenchang 68 to 122,and Sanya 61 to 109 ARGs.Notably,16 sampling points harbored over 110 ARGs.Quantitative analysis revealed ARG concentrations ranging from 16,167 to 1,784,618 copies/ng.Co-occurrence network analysis demonstrated that most ARGs were associated with MGEs,16S rRNA genes,transposons,and integrons,indicating these elements'critical role in horizontal gene transfer.Microbial community profiling identified 27,050 operational taxonomic units(OTUs)across 72 phyla,153 classes,371 orders,459 families,and 924 genera,with Proteobacteria,Bacteroidota,Actinobacteriota,Cyanobacteria,and Planctomycetota as dominant taxa.Genus-level analysis revealed significant variations in the abundance of taxa such as Cyanobium_PCC-6307,Candidatus_Actinomarina,and HIMB11 across sampling sites.Environmental parameters,including pH,dissolved oxygen(DO),specific conductance(SPC),salinity(SAL),temperature(T),and pressure(kPa),showed strong correlations with ARG distribution and microbial community composition.Region-specific colinearity networks indicated distinct relationships between microbial taxa and ARGs;notably,Danzhou and Wanning exhibited strong correlations with over 20 ARGs per genus,whereas Wenchang displayed a more complex association pattern,suggesting a multifaceted role in ARG transmission pathways.Overall,the findings suggest that environmental factors and microbial hosts significantly influence ARG prevalence in Hainan's coastal waters,with regional variations in microbial-ARG interactions,particularly in Wenchang,indicating heightened transmission risks.This study offers vital insights for sustainable aquaculture practices and informs regional regulatory strategies for aquaculture management.
基金supported by the Yunnan Provincial College and Institute Science and Technology Cooperation Projects (Grant No.2006YX26)the Technological Innovation and Technical Development Special Projects in Yunnan Province (Grant No.2007GA007)
文摘The shapes of block within the rock mass have an important effect on the rock properties, so it＇s very important to evaluate the shapes of rock fragmentation and to determine the geometric characteristics distribution of the block. The previous methods to classify rock block shape are based on the assumption that a block shape is approximately orthogonal, which is acceptable in only a few rock masses. This paper proposes a new method for block shape classification using triangular diagram together with parameters of co-linearity e and volume coefficient K, which combines the shape categorization with block volume for statistical analysis. Rock block equivalent size calculation methods based on block shape is proposed and the block cumulative percentage of total volume statistical analysis is given. In order to verify this block shape classification method, three ideal rock masses with approximately orthogonal joint sets have been generated and simulated.
