Correction to:J.For.Res.(2022)33:689–698 https://doi.org/10.1007/s11676-021-01335-7 In the Original Publication,the text“Acknowledgements sdfkjds”has been inadvertently appeared in the paper.The Original article ha...Correction to:J.For.Res.(2022)33:689–698 https://doi.org/10.1007/s11676-021-01335-7 In the Original Publication,the text“Acknowledgements sdfkjds”has been inadvertently appeared in the paper.The Original article has been corrected.展开更多
Myopia is the leading cause of visual impairments worldwide. Some studies revealed that visual experience in early life affected the final myopia, indicating that environmental factors play an impellent role in the de...Myopia is the leading cause of visual impairments worldwide. Some studies revealed that visual experience in early life affected the final myopia, indicating that environmental factors play an impellent role in the development of myopia. However, risk factors of myopia are still not identified among adolescents in China. A total of 4104 cases of myopia symptom and 3306 emmetropia controls were selected from students in primary and middle schools in Wuhan in 2008. We identified the risk factors associated with myopia symptom by multivariate logistic regression in this cross-sectional study and constructed a risk score system for myopia symptom. The value of the area under the receiver operating characteristic curve (ROC) was 0.735. Furthermore, we followed up 93 students aged 7-9 years for one year and calculated the total points using the score system. We found no significant difference between the final myopia symptom and the results predicted by the total points by pair chi-square test (P>0.05). The score system had a modest ability to estimate the risk factors of myopia symptom. Using this score system, we could identify the students who are at risk of myopia symptom in the future according to their behaviors and environmental factors, and take measures to slow the progress of myopia symptom.展开更多
The Cu(Ⅱ) separation behaviors with polymer inclusion membranes(PIMs) are explored by modifying 2-aminomethylpyridine derivatives with hydrophobic alkyl chains, including 2-[N-(tert-butyloxycarbonylmethyl)-2-picolyam...The Cu(Ⅱ) separation behaviors with polymer inclusion membranes(PIMs) are explored by modifying 2-aminomethylpyridine derivatives with hydrophobic alkyl chains, including 2-[N-(tert-butyloxycarbonylmethyl)-2-picolyamino]acetate(AMB), N,N-dioctyl-2-aminomethylpyridine(AMD), tert-butyl 2-(N-octyl-2-picolyamino) acetate(AMC), and N,N-didecyl-2-aminomethylpyridine(AME). The transport flux and selectivity of Cu(Ⅱ) are determined by optimizing composition and structure of carriers and plasticizers. The results show that the hydrophobic modification of 2-aminomethylpyridine derivatives can boost the selective transport of copper ions in PIMs and membrane stability. In the optimum composition of 30 wt.% PVC, 30 wt.% AME, and 40 wt.% NPOE, the initial flux of Cu(Ⅱ) is 5.8×10^(−6) mol·m^(−2)·s^(−1). The FT-IR and XPS spectra identify that the alkyl amine functional groups of AME involve in the transport of copper chloride species. The SAXS analysis demonstrates that the generated micro-channels in PIMs induced by the hydrophobic modification of 2-aminomethylpyridine derivatives can contribute to the enhanced Cu(Ⅱ) flux.展开更多
Bursaphelenchus xylophilus,causal agent of pine wilt disease,causes extensive damage worldwide.Strate-gies are needed to inhibit population growth or block the spread of the invasive nematode to control pine wilt dis-...Bursaphelenchus xylophilus,causal agent of pine wilt disease,causes extensive damage worldwide.Strate-gies are needed to inhibit population growth or block the spread of the invasive nematode to control pine wilt dis-ease.The gene daf-8 plays crucial roles in larval develop-ment and dauer formation in Caenorhabditis elegans,but little is known about its orthologue in B.xylophilus.In the present molecular characterization and functional analysis of daf-8 in B.xylophilus(Bx-daf-8),RT-qPCR showed that the expression of Bx-daf-8 gradually increased during the embryonic stage,peaked in the second-stage juvenile(J2),then dramatically dropped in the J3,and remained at that low level for the rest of its life.Bx-daf-8-transgenic C.elegans was employed to mimic the spatiotemporal expression of Bx-daf-8,which was expressed close to the pharynx during early embryogenesis and weakly throughout the whole body during late embryogenesis.It was observed in head neurons and tail ganglions throughout all postembryonic stages.B.xylophilus embryos were severely abnormal,and hatching rate decreased sharply after Bx-daf-8 knockdown.daf-16-1 and da-f16-2,downstream genes in the IIS pathway,also dropped sharply after Bx-daf-8 knockdown.We propose that TGFβmay crosstalk with the IIS pathway upstream of Bx-daf-16 and that daf-8 may act as a master regulator of daf-16 in B.xylophilus.However,knockdown of Bx-daf-8 did not lead to constitutive developmental arrest at the dauer larval stage,indicating that dauer entry in B.xylophilus might be controlled by several genes and is more complicated than in C.elegans.Bx-daf-8 alone did not control the dauer entry in B.xylophilus,but it was indispensable for embryogen-esis,providing a potential target for suppressing population growth of B.xylophilus.展开更多
Ecological footprint is a method of measuring how much we use the natural resources and how much the nature provides services for human beings. This paper summarized the application of ecological footprint at differen...Ecological footprint is a method of measuring how much we use the natural resources and how much the nature provides services for human beings. This paper summarized the application of ecological footprint at different scales and in different fields and different ecological types at home and abroad,analyzed the advantages and disadvantages of ecological footprint method,and made a prediction of the application of ecological footprint.展开更多
Glutamate dehydrogenase(GDH)plays an important role in the ammonium assimilation and nitrogen metabolism by catalyzing the reversible oxidative deamination of L-glutamate toα-ketoglutarate.In the present study,the po...Glutamate dehydrogenase(GDH)plays an important role in the ammonium assimilation and nitrogen metabolism by catalyzing the reversible oxidative deamination of L-glutamate toα-ketoglutarate.In the present study,the potential functions of GDH in response to heat stre ss were explored in the scleractinian coral Pocillopora damicornis(designated as PdGDH).The cDNA of PdGDH contained an open reading frame of 1611 bp encoding a polypeptide of 536 amino acids,which exhibited the highest sequence identity to GDH of Stylophora pistillata(96%identity),and the deduced PdGDH protein was predicted to contain one GdhA domain(from Val95 to Tyr525).The recombinant protein of PdGDH(rPdGDH)was expressed in Escherichia coli BL21(DE3)-Transetta,and its catalytic activity was measured under different temperatures,pH conditions and epigallocatechin-3-gallate(EGCG,a GDH inhibitor)concentrations.The purified rPdGDH only used reduced coenzyme nicotinamide adenine dinucleotide(NADH)as coenzyme,and its highe st activity was observed at 35℃and pH 7.5,re spectively.The rPdGDH activity was negatively correlated with the concentration of EGCG,and was inhibited by more than half(65%,P<0.05)at 10mol/L EGCG.No significant alteration of PdGDH mRNA expression was detected at 12 h after exposure to heat and ammonium(P>0.05).Furthermore,the activities of NADH-GDH in the scleractinian coral P.damicornis increased significantly at 12 h after the heat and ammonium stress,and the NADH-GDH activity in the heat stress group(32.66 U/mg,P<0.05)was significantly higher than that in the heat and ammonium stress group(11.26 U/mg).These results collectively suggested that PdGDH,as a homologue of glutamate dehydrogenase in the scleractinian coral P.damicornis,could respond to heat stress at the protein level,which would have ability to further promote ammonium assimilation to increase the heat acclimatization of the coral-Symbiodiniaceae symbiotic association.展开更多
Actinobacillus pleuropneumoniae(APP)is the major pathogen of porcine contagious pleuropneumoniae(PCP).The QseB/QseC two-component system(TCS)consists of the regulator QseB and the kinase QseC,which relates to quorum s...Actinobacillus pleuropneumoniae(APP)is the major pathogen of porcine contagious pleuropneumoniae(PCP).The QseB/QseC two-component system(TCS)consists of the regulator QseB and the kinase QseC,which relates to quorum sensing(QS)and virulence in some bacteria.Here,we investigated the role of QseB/QseC in apf gene cluster(apfABCD)expression of APP.Our results have showed that QseB/QseC TCS can potentially regulate the expression of apf gene cluster.The△qseBC,△apfA,△apfB,△apfC and△apfD strains are more sensitive to acidic and osmotic stressful conditions,and exhibite lower biofilm formation ability than wild-type(WT)strain,whereas the complemented strains show similar phenotype to the wr strain.In additon,the mutants have defective antiphagocytosis,adhesion and invasion when they come into contact with the host cells.In experimental animal models of infection,mice infected with△qseBC,△apfA,△apfB,△apfC and △apfD strains showed lower mortality and bacterial loads in the lung and the blood than those infected with wr strain.In conclusion,our results suggest that QseB/QseC TCS contributes to stress resistance,biofilm formation,phagocytosis,adhesion,invasion and virulence by downregulating expression of apf gene cluster in A.pleuropneumoniae.展开更多
The estimation was made for the conservation value of forest ecosystem biodiversity in Nyingchi Prefecture of Tibet.The results showed that the annual economic benefits of biodiversity in Nyingchi Prefecture were abou...The estimation was made for the conservation value of forest ecosystem biodiversity in Nyingchi Prefecture of Tibet.The results showed that the annual economic benefits of biodiversity in Nyingchi Prefecture were about 21.4 billion yuan,and the annual economic benefits of global biodiversity were about 3 trillion USD.It indicated that the ecological value of forest ecosystem in Nyingchi Prefecture is high,forest ecosystem has extremely important ecological value.Therefore,in the decision-making process,it is necessary to strengthen the protection of forest ecosystem,with particular emphasis on the restoration of damaged ecosystem.展开更多
In this study,we choose the street green space in Bayi District,Mainling Town of Mainling County and Zhamu Town of Bomê County in Nyingchi City as investigation sites.In each investigation site,we select the unda...In this study,we choose the street green space in Bayi District,Mainling Town of Mainling County and Zhamu Town of Bomê County in Nyingchi City as investigation sites.In each investigation site,we select the undamaged plant communities of moderate density as objects of investigation and record,and establish the investigation database.Based on the habitat records and natural ecological conditions,we analyze the growth adaptability of Ligustrum L.plants in Southeast Tibet and the key influencing factors.It is found that the Ligustrum L.plants introduced in Southeast Tibet mainly include Ligustrum lucidum Ait.,Ligustrum quihoui Carr.and Ligustrum vicaryi.The growth adaptability of Ligustrum lucidum Ait.plants is divided into high level,middle level and low level.According to the investigation results,the frequency of Ligustrum lucidum Ait.plants with good growth status is greater than 65%.In general,the plants are fond of light,and have certain tolerance to cold.They can be cultivated in open field and show good growth adaptability in Southeast Tibet,so these plants can be further applied.展开更多
China’s rapid economic development has initiated the deterioration of its ecological environment,posing a threat to the sustainable development of human society.As a result,an assessment of regional sustainability is...China’s rapid economic development has initiated the deterioration of its ecological environment,posing a threat to the sustainable development of human society.As a result,an assessment of regional sustainability is critical.This paper researches China’s most forested province,Fujian Province,as the study area.We proposed a grid-based approach to assess the regional carbon footprint in accordance with the Intergovernmental Panel on Climate Change’s(IPCC)carbon emission guidelines.Our method of assessment also introduced carbon emission indicators with our improved and published Net Primary Production(NPP)based on process simulation.The carbon footprint in Fujian Province from 2005-2017 was calculated and examined from a spatiotemporal perspective.Ecological indicators were used in the sustainability assessment.The research draws the following conclusions:1)the carbon footprint in the eastern regions of Fujian Province was higher due to rapid economic development;2)that of the western regions was lower;3)an uptrend in the carbon footprint of Fujian Province was observed.All five ecological indicators based on carbon emissions and economic and social data showed an ecologically unsustainable trend over 13 years in the research area due to unsustainable economic development.Therefore,it is urgent to balance the relationship between economic development and environmental protection.Our research provides scientific references for achieving ecological civilization and sustainability in a similar region.展开更多
The hexavalent chromium(Cr(Ⅵ))would frequently impose inhibition to anaerobic ammonium oxidation(anammox)process,hindering the efficiency of nitrogen removal in wastewater treatment.Hydrazine(N2H4),which is an interm...The hexavalent chromium(Cr(Ⅵ))would frequently impose inhibition to anaerobic ammonium oxidation(anammox)process,hindering the efficiency of nitrogen removal in wastewater treatment.Hydrazine(N2H4),which is an intermediate product of anammox,participates in intracellular metabolism and extracellular Cr(Ⅵ)reduction.However,the roles of N_(2)H_(4)-induced intracellular metabolism and extracellular reduction in nitrogen removal under Cr(Ⅵ)stress remain unclear.The addition of 3.67 mg/L of N2H4 increased the anammox activity by 17%.As an intermediate,N2H4 enhanced anammox metabolism by increasing the heme c content and electron transfer system activity.As a reductant,N_(2)H_(4) accelerated the reduction of c-Cyts-mediated extracellular Cr(Ⅵ)to the less toxic Cr(Ⅲ).Extracellular Cr(Ⅲ)accounts for 74%of the total Cr in a Cr(Ⅵ)-stressed anammox consortia.These findings highlight that N_(2)H_(4)-induced extracellular Cr(Ⅵ)reduction is the dominant mechanism for the survival of anammox consortia.We also found that N_(2)H_(4) increased the production of extracellular polymeric substances to sequester excessive Cr(Ⅵ)and produced Cr(Ⅲ).Taken together,the study findings suggest a potential strategy for enhancing nitrogen removal from ammonium-rich wastewater contaminated with Cr(Ⅵ).展开更多
The development of soil crust on sandy land may affect the surface hydrological process.This paper investigates the process of evaporation and dew deposition influenced by different soil surface types which were domin...The development of soil crust on sandy land may affect the surface hydrological process.This paper investigates the process of evaporation and dew deposition influenced by different soil surface types which were dominated by sand,primitive biotic crust,and advanced biotic crust,respectively,in the south fringe of Mu Us sandy land in Northwest China from July to September of 2006.The experimental results indicate that the advanced biotic crust could increase evaporation and dew deposition compared to the primitive biotic crust and bare sand although the differences between them were not significant.The average evaporation from advanced biotic crust,primitive biotic crust and sand was 6.8,6.6,and 6.5 mm/d,respectively,and water content is around 16.2%in the condition of initially identical soil.The average dew amount on advanced biotic crust was 0.116 mm/d with extreme 0.05 and 0.24 mm/d.The average values on primitive biotic crust and sand were 0.105 and 0.101 mm/d,respectively,with extreme 0.04 and 0.21 mm/d for both treatments.Also,the dew deposition on advanced biotic crust seemed stable and might rest for a longer time than that on primitive biotic crust and sand.The results suggest that the advanced biotic crust possibly facilitates evaporation and dew deposition.Therefore,the development of biotic crust may potentially enhance the hydrological circulation in the upper sand layer in sandy land.展开更多
Remote sensing spatiotemporal fusion models blend multi-source images of different spatial resolutions to create synthetic images with high resolution and frequency,contributing to time series research where high qual...Remote sensing spatiotemporal fusion models blend multi-source images of different spatial resolutions to create synthetic images with high resolution and frequency,contributing to time series research where high quality observations are not available with sufficient frequency.However,existing models are vulnerable to spatial heterogeneity and land cover changes,which are frequent in human-dominated regions.To obtain quality time series of satellite images in a human-dominated region,this study developed the Modified Flexible Spatial-temporal Data Fusion(MFSDAF)approach based on the Flexible Spatial-temporal Data Fusion(FSDAF)model by using the enhanced linear regression(ELR).Multiple experiments of various land cover change scenarios were conducted based on both actual and simulated satellite images,respectively.The proposed MFSDAF model was validated by using the correlation coefficient(r),relative root mean square error(RRMSE),and structural similarity(SSIM),and was then compared with the Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model(ESTARFM)and FSDAF models.Results show that in the presence of significant land cover change,MFSDAF showed a maximum increase in r,RRMSE,and SSIM of 0.0313,0.0109 and 0.049,respectively,compared to FSDAF,while ESTARFM performed best with less temporal difference of in the input images.In conditions of stable landscape changes,the three performance statistics indicated a small advantage of MFSDAF over FSDAF,but were 0.0286,0.0102,0.0317 higher than for ESTARFM,respectively.MFSDAF showed greater accuracy of capturing subtle changes and created high-precision images from both actual and simulated satellite images.展开更多
A chemical investigation on Sporormiella sp.led to the isolation and structural elucidation of tripodalsporormielones Ae C(1-3),a new class of polyketide possessing unprecedented cage-like skeletons with polyvdent bri...A chemical investigation on Sporormiella sp.led to the isolation and structural elucidation of tripodalsporormielones Ae C(1-3),a new class of polyketide possessing unprecedented cage-like skeletons with polyvdent bridged and fused ring systems.These polyketides with cage-like skeletons were characterized as a high non-protonated carbon-containing system,which resulted in few HMBC correlations observed and made the accurate structures hard to be obtained by NMR.Especially,some signals of non-protonated sp;carbons are weak and even unobservable in compound 1.In order to establish the structure of 1,the calculated NMR with DP4 evaluation was applied to determine the structure from the plausible structure candidates obtained from the detailed NMR analysis.Based on NMR experiments and calculated NMR,the structures of isolated compounds were established and confirmed by X-ray technology.Through chiral isolation,the optically pure enantiomers of 1 and 3 were obtained,and their absolute configurations were determined based on ECD quantum chemical calculation.Based on the isolated compounds and our previous work,1-3 would be derived from 3-methylorcinaldehyde,and their plausible biosynthetic mechanism was proposed.Furthermore,1 exhibited obvious short-term memory improvement activity on an Alzheimer’s disease fly model.展开更多
文摘Correction to:J.For.Res.(2022)33:689–698 https://doi.org/10.1007/s11676-021-01335-7 In the Original Publication,the text“Acknowledgements sdfkjds”has been inadvertently appeared in the paper.The Original article has been corrected.
文摘Myopia is the leading cause of visual impairments worldwide. Some studies revealed that visual experience in early life affected the final myopia, indicating that environmental factors play an impellent role in the development of myopia. However, risk factors of myopia are still not identified among adolescents in China. A total of 4104 cases of myopia symptom and 3306 emmetropia controls were selected from students in primary and middle schools in Wuhan in 2008. We identified the risk factors associated with myopia symptom by multivariate logistic regression in this cross-sectional study and constructed a risk score system for myopia symptom. The value of the area under the receiver operating characteristic curve (ROC) was 0.735. Furthermore, we followed up 93 students aged 7-9 years for one year and calculated the total points using the score system. We found no significant difference between the final myopia symptom and the results predicted by the total points by pair chi-square test (P>0.05). The score system had a modest ability to estimate the risk factors of myopia symptom. Using this score system, we could identify the students who are at risk of myopia symptom in the future according to their behaviors and environmental factors, and take measures to slow the progress of myopia symptom.
基金financial supports from the National Key R&D Program of China(No.2019YFC1907801)National Natural Science Foundation of China(No.52174286)+1 种基金Hunan Provincial Science and Technology Plan Project,China(No.2019JJ30031)InnovationDriven of Central South University,China(No.2020CX007)。
文摘The Cu(Ⅱ) separation behaviors with polymer inclusion membranes(PIMs) are explored by modifying 2-aminomethylpyridine derivatives with hydrophobic alkyl chains, including 2-[N-(tert-butyloxycarbonylmethyl)-2-picolyamino]acetate(AMB), N,N-dioctyl-2-aminomethylpyridine(AMD), tert-butyl 2-(N-octyl-2-picolyamino) acetate(AMC), and N,N-didecyl-2-aminomethylpyridine(AME). The transport flux and selectivity of Cu(Ⅱ) are determined by optimizing composition and structure of carriers and plasticizers. The results show that the hydrophobic modification of 2-aminomethylpyridine derivatives can boost the selective transport of copper ions in PIMs and membrane stability. In the optimum composition of 30 wt.% PVC, 30 wt.% AME, and 40 wt.% NPOE, the initial flux of Cu(Ⅱ) is 5.8×10^(−6) mol·m^(−2)·s^(−1). The FT-IR and XPS spectra identify that the alkyl amine functional groups of AME involve in the transport of copper chloride species. The SAXS analysis demonstrates that the generated micro-channels in PIMs induced by the hydrophobic modification of 2-aminomethylpyridine derivatives can contribute to the enhanced Cu(Ⅱ) flux.
基金The work was supported by the National Natural Science Foundation of China(31870633,31700565,31670652,31570638 and 31270688)National Key Research and Development Plan of China(2017YFD0600102-03).
文摘Bursaphelenchus xylophilus,causal agent of pine wilt disease,causes extensive damage worldwide.Strate-gies are needed to inhibit population growth or block the spread of the invasive nematode to control pine wilt dis-ease.The gene daf-8 plays crucial roles in larval develop-ment and dauer formation in Caenorhabditis elegans,but little is known about its orthologue in B.xylophilus.In the present molecular characterization and functional analysis of daf-8 in B.xylophilus(Bx-daf-8),RT-qPCR showed that the expression of Bx-daf-8 gradually increased during the embryonic stage,peaked in the second-stage juvenile(J2),then dramatically dropped in the J3,and remained at that low level for the rest of its life.Bx-daf-8-transgenic C.elegans was employed to mimic the spatiotemporal expression of Bx-daf-8,which was expressed close to the pharynx during early embryogenesis and weakly throughout the whole body during late embryogenesis.It was observed in head neurons and tail ganglions throughout all postembryonic stages.B.xylophilus embryos were severely abnormal,and hatching rate decreased sharply after Bx-daf-8 knockdown.daf-16-1 and da-f16-2,downstream genes in the IIS pathway,also dropped sharply after Bx-daf-8 knockdown.We propose that TGFβmay crosstalk with the IIS pathway upstream of Bx-daf-16 and that daf-8 may act as a master regulator of daf-16 in B.xylophilus.However,knockdown of Bx-daf-8 did not lead to constitutive developmental arrest at the dauer larval stage,indicating that dauer entry in B.xylophilus might be controlled by several genes and is more complicated than in C.elegans.Bx-daf-8 alone did not control the dauer entry in B.xylophilus,but it was indispensable for embryogen-esis,providing a potential target for suppressing population growth of B.xylophilus.
基金Supported by the Innovation Project for College Young Teachers in Tibet Autonomous Region"Ecological Economic System Assessment of Tibet Based on Ecological Footprint Theory"(QC2015-28)
文摘Ecological footprint is a method of measuring how much we use the natural resources and how much the nature provides services for human beings. This paper summarized the application of ecological footprint at different scales and in different fields and different ecological types at home and abroad,analyzed the advantages and disadvantages of ecological footprint method,and made a prediction of the application of ecological footprint.
基金Supported by the Major Science and Technology Program of Hainan Province (No. ZDKJ2019011)the ISF-NSFC Joint Scientifi c Research Program (No. 42161144006 or 3511/21)+1 种基金the National Natural Science Foundation of China (Nos. 31772460, 42076145)the Hainan Provincial Natural Science Foundation of China (Nos. 2019RC067, 420CXTD432)
文摘Glutamate dehydrogenase(GDH)plays an important role in the ammonium assimilation and nitrogen metabolism by catalyzing the reversible oxidative deamination of L-glutamate toα-ketoglutarate.In the present study,the potential functions of GDH in response to heat stre ss were explored in the scleractinian coral Pocillopora damicornis(designated as PdGDH).The cDNA of PdGDH contained an open reading frame of 1611 bp encoding a polypeptide of 536 amino acids,which exhibited the highest sequence identity to GDH of Stylophora pistillata(96%identity),and the deduced PdGDH protein was predicted to contain one GdhA domain(from Val95 to Tyr525).The recombinant protein of PdGDH(rPdGDH)was expressed in Escherichia coli BL21(DE3)-Transetta,and its catalytic activity was measured under different temperatures,pH conditions and epigallocatechin-3-gallate(EGCG,a GDH inhibitor)concentrations.The purified rPdGDH only used reduced coenzyme nicotinamide adenine dinucleotide(NADH)as coenzyme,and its highe st activity was observed at 35℃and pH 7.5,re spectively.The rPdGDH activity was negatively correlated with the concentration of EGCG,and was inhibited by more than half(65%,P<0.05)at 10mol/L EGCG.No significant alteration of PdGDH mRNA expression was detected at 12 h after exposure to heat and ammonium(P>0.05).Furthermore,the activities of NADH-GDH in the scleractinian coral P.damicornis increased significantly at 12 h after the heat and ammonium stress,and the NADH-GDH activity in the heat stress group(32.66 U/mg,P<0.05)was significantly higher than that in the heat and ammonium stress group(11.26 U/mg).These results collectively suggested that PdGDH,as a homologue of glutamate dehydrogenase in the scleractinian coral P.damicornis,could respond to heat stress at the protein level,which would have ability to further promote ammonium assimilation to increase the heat acclimatization of the coral-Symbiodiniaceae symbiotic association.
基金supported by grants from the Technique Innovation Program of Hubei Province(No.2018ABA108)the National Pig Industry Technology System(No.CARS-35).
文摘Actinobacillus pleuropneumoniae(APP)is the major pathogen of porcine contagious pleuropneumoniae(PCP).The QseB/QseC two-component system(TCS)consists of the regulator QseB and the kinase QseC,which relates to quorum sensing(QS)and virulence in some bacteria.Here,we investigated the role of QseB/QseC in apf gene cluster(apfABCD)expression of APP.Our results have showed that QseB/QseC TCS can potentially regulate the expression of apf gene cluster.The△qseBC,△apfA,△apfB,△apfC and△apfD strains are more sensitive to acidic and osmotic stressful conditions,and exhibite lower biofilm formation ability than wild-type(WT)strain,whereas the complemented strains show similar phenotype to the wr strain.In additon,the mutants have defective antiphagocytosis,adhesion and invasion when they come into contact with the host cells.In experimental animal models of infection,mice infected with△qseBC,△apfA,△apfB,△apfC and △apfD strains showed lower mortality and bacterial loads in the lung and the blood than those infected with wr strain.In conclusion,our results suggest that QseB/QseC TCS contributes to stress resistance,biofilm formation,phagocytosis,adhesion,invasion and virulence by downregulating expression of apf gene cluster in A.pleuropneumoniae.
基金Supported by Humanity and Social Science Project of Colleges and Universities in Tibet Autonomous Region in 2015 "Study on Ecological Economy Construction in Tibet:A Case Study of Nyingchi Prefecture"(sk2015-33)
文摘The estimation was made for the conservation value of forest ecosystem biodiversity in Nyingchi Prefecture of Tibet.The results showed that the annual economic benefits of biodiversity in Nyingchi Prefecture were about 21.4 billion yuan,and the annual economic benefits of global biodiversity were about 3 trillion USD.It indicated that the ecological value of forest ecosystem in Nyingchi Prefecture is high,forest ecosystem has extremely important ecological value.Therefore,in the decision-making process,it is necessary to strengthen the protection of forest ecosystem,with particular emphasis on the restoration of damaged ecosystem.
基金Supported by Natural Science Foundation of Tibet Autonomous Region(2016-ZR-15-42)
文摘In this study,we choose the street green space in Bayi District,Mainling Town of Mainling County and Zhamu Town of Bomê County in Nyingchi City as investigation sites.In each investigation site,we select the undamaged plant communities of moderate density as objects of investigation and record,and establish the investigation database.Based on the habitat records and natural ecological conditions,we analyze the growth adaptability of Ligustrum L.plants in Southeast Tibet and the key influencing factors.It is found that the Ligustrum L.plants introduced in Southeast Tibet mainly include Ligustrum lucidum Ait.,Ligustrum quihoui Carr.and Ligustrum vicaryi.The growth adaptability of Ligustrum lucidum Ait.plants is divided into high level,middle level and low level.According to the investigation results,the frequency of Ligustrum lucidum Ait.plants with good growth status is greater than 65%.In general,the plants are fond of light,and have certain tolerance to cold.They can be cultivated in open field and show good growth adaptability in Southeast Tibet,so these plants can be further applied.
基金supported by the National Natural Science Foundation of China(Grant No.41601562)sponsored by China Scholarship Council(No.201806655014)+1 种基金the Research Project for Young Teachers of Fujian Province(No.JAT160085)the Scientific Research Foundation of Fuzhou University(No.XRC-1536).
文摘China’s rapid economic development has initiated the deterioration of its ecological environment,posing a threat to the sustainable development of human society.As a result,an assessment of regional sustainability is critical.This paper researches China’s most forested province,Fujian Province,as the study area.We proposed a grid-based approach to assess the regional carbon footprint in accordance with the Intergovernmental Panel on Climate Change’s(IPCC)carbon emission guidelines.Our method of assessment also introduced carbon emission indicators with our improved and published Net Primary Production(NPP)based on process simulation.The carbon footprint in Fujian Province from 2005-2017 was calculated and examined from a spatiotemporal perspective.Ecological indicators were used in the sustainability assessment.The research draws the following conclusions:1)the carbon footprint in the eastern regions of Fujian Province was higher due to rapid economic development;2)that of the western regions was lower;3)an uptrend in the carbon footprint of Fujian Province was observed.All five ecological indicators based on carbon emissions and economic and social data showed an ecologically unsustainable trend over 13 years in the research area due to unsustainable economic development.Therefore,it is urgent to balance the relationship between economic development and environmental protection.Our research provides scientific references for achieving ecological civilization and sustainability in a similar region.
基金supported by the National Natural Science Foundations of China(No.52000182,U21A20294,51878662)the Natural Science Foundation of Hunan Province(No.2020JJ4725)the Technological Innovation Guidance Program of Jiangxi Province(No.20203BDH80W017).
文摘The hexavalent chromium(Cr(Ⅵ))would frequently impose inhibition to anaerobic ammonium oxidation(anammox)process,hindering the efficiency of nitrogen removal in wastewater treatment.Hydrazine(N2H4),which is an intermediate product of anammox,participates in intracellular metabolism and extracellular Cr(Ⅵ)reduction.However,the roles of N_(2)H_(4)-induced intracellular metabolism and extracellular reduction in nitrogen removal under Cr(Ⅵ)stress remain unclear.The addition of 3.67 mg/L of N2H4 increased the anammox activity by 17%.As an intermediate,N2H4 enhanced anammox metabolism by increasing the heme c content and electron transfer system activity.As a reductant,N_(2)H_(4) accelerated the reduction of c-Cyts-mediated extracellular Cr(Ⅵ)to the less toxic Cr(Ⅲ).Extracellular Cr(Ⅲ)accounts for 74%of the total Cr in a Cr(Ⅵ)-stressed anammox consortia.These findings highlight that N_(2)H_(4)-induced extracellular Cr(Ⅵ)reduction is the dominant mechanism for the survival of anammox consortia.We also found that N_(2)H_(4) increased the production of extracellular polymeric substances to sequester excessive Cr(Ⅵ)and produced Cr(Ⅲ).Taken together,the study findings suggest a potential strategy for enhancing nitrogen removal from ammonium-rich wastewater contaminated with Cr(Ⅵ).
基金This study was financially co-supported by the National Natural Science Foundation of China(Grant No.40571023)the Foundation for the Author of National Excellent Doctoral Dissertation of China(Grant No.200426)the Ministry of Science and Technology,China(Grant No.2006BAD26B07).
文摘The development of soil crust on sandy land may affect the surface hydrological process.This paper investigates the process of evaporation and dew deposition influenced by different soil surface types which were dominated by sand,primitive biotic crust,and advanced biotic crust,respectively,in the south fringe of Mu Us sandy land in Northwest China from July to September of 2006.The experimental results indicate that the advanced biotic crust could increase evaporation and dew deposition compared to the primitive biotic crust and bare sand although the differences between them were not significant.The average evaporation from advanced biotic crust,primitive biotic crust and sand was 6.8,6.6,and 6.5 mm/d,respectively,and water content is around 16.2%in the condition of initially identical soil.The average dew amount on advanced biotic crust was 0.116 mm/d with extreme 0.05 and 0.24 mm/d.The average values on primitive biotic crust and sand were 0.105 and 0.101 mm/d,respectively,with extreme 0.04 and 0.21 mm/d for both treatments.Also,the dew deposition on advanced biotic crust seemed stable and might rest for a longer time than that on primitive biotic crust and sand.The results suggest that the advanced biotic crust possibly facilitates evaporation and dew deposition.Therefore,the development of biotic crust may potentially enhance the hydrological circulation in the upper sand layer in sandy land.
基金This research received financial support by the National Natural Science Foundation of China(Grant Nos.41601562 and 41761014)the National Key Research and Development Program of China(No.2017YFC1502404)+1 种基金the China Institute of Water Resources and Hydropower Research Team Construction and Talent Development Project(No.JZ0145B752017)the Research Project for Young Teachers of Fujian Province(No.JAT160085).
文摘Remote sensing spatiotemporal fusion models blend multi-source images of different spatial resolutions to create synthetic images with high resolution and frequency,contributing to time series research where high quality observations are not available with sufficient frequency.However,existing models are vulnerable to spatial heterogeneity and land cover changes,which are frequent in human-dominated regions.To obtain quality time series of satellite images in a human-dominated region,this study developed the Modified Flexible Spatial-temporal Data Fusion(MFSDAF)approach based on the Flexible Spatial-temporal Data Fusion(FSDAF)model by using the enhanced linear regression(ELR).Multiple experiments of various land cover change scenarios were conducted based on both actual and simulated satellite images,respectively.The proposed MFSDAF model was validated by using the correlation coefficient(r),relative root mean square error(RRMSE),and structural similarity(SSIM),and was then compared with the Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model(ESTARFM)and FSDAF models.Results show that in the presence of significant land cover change,MFSDAF showed a maximum increase in r,RRMSE,and SSIM of 0.0313,0.0109 and 0.049,respectively,compared to FSDAF,while ESTARFM performed best with less temporal difference of in the input images.In conditions of stable landscape changes,the three performance statistics indicated a small advantage of MFSDAF over FSDAF,but were 0.0286,0.0102,0.0317 higher than for ESTARFM,respectively.MFSDAF showed greater accuracy of capturing subtle changes and created high-precision images from both actual and simulated satellite images.
基金financially supported by grants from National Key Research and Development Program of China(2018YF A0903200/2018YFA0903201)the National Natural Science Foundation of China(81925037 and 81973213)+5 种基金Chang Jiang Scholars Program(Young Scholar)from the Ministry of Education of China(Hao Gao,2017)National High-level Personnel of Special Support Program(2017RA2259,China)the 111 Project of Ministry of Education of the People’s Republic of China(B13038)the Guangdong Natural Science Funds for Distinguished Young Scholar(2017A03036027,China)Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01Y036,China)K.C.Wong Education Foundation(Hao Gao,2016,China)。
文摘A chemical investigation on Sporormiella sp.led to the isolation and structural elucidation of tripodalsporormielones Ae C(1-3),a new class of polyketide possessing unprecedented cage-like skeletons with polyvdent bridged and fused ring systems.These polyketides with cage-like skeletons were characterized as a high non-protonated carbon-containing system,which resulted in few HMBC correlations observed and made the accurate structures hard to be obtained by NMR.Especially,some signals of non-protonated sp;carbons are weak and even unobservable in compound 1.In order to establish the structure of 1,the calculated NMR with DP4 evaluation was applied to determine the structure from the plausible structure candidates obtained from the detailed NMR analysis.Based on NMR experiments and calculated NMR,the structures of isolated compounds were established and confirmed by X-ray technology.Through chiral isolation,the optically pure enantiomers of 1 and 3 were obtained,and their absolute configurations were determined based on ECD quantum chemical calculation.Based on the isolated compounds and our previous work,1-3 would be derived from 3-methylorcinaldehyde,and their plausible biosynthetic mechanism was proposed.Furthermore,1 exhibited obvious short-term memory improvement activity on an Alzheimer’s disease fly model.