Araneiforms are spider-like ground patterns that are widespread in the southern polar regions of Mars.A gas erosion process driven by the seasonal sublimation of CO_(2) ice was proposed as an explanation for their for...Araneiforms are spider-like ground patterns that are widespread in the southern polar regions of Mars.A gas erosion process driven by the seasonal sublimation of CO_(2) ice was proposed as an explanation for their formation,which cannot occur on Earth due to the high climatic temperature.In this study,we propose an alternative mechanism that attrib-utes the araneiform formation to the erosion of upwelling salt water from the subsurface,relying on the identification of the first terrestrial analog found in a playa of the Qaidam Basin on the northern Tibetan Plateau.Morphological analysis indicates that the structures in the Qaidam Basin have fractal features comparable to araneiforms on Mars.A numerical model is developed to investigate the araneiform formation driven by the water-diffusion mechanism.The simulation res-ults indicate that the water-diffusion process,under varying ground conditions,may be responsible for the diverse aranei-form morphologies observed on both Earth and Mars.Our numerical simulations also demonstrate that the orientations of the saltwater diffusion networks are controlled by pre-existing polygonal cracks,which is consistent with observations of araneiforms on Mars and Earth.Our study thus suggests that a saltwater-related origin of the araneiform is possible and has significant implications for water searches on Mars.展开更多
Pinus elliottii×P.caribaea is a widely planted commercial tree hybrid in South China.To investigate the potential of physiological parameters for clonal selection,cuttings of three clones(EH3,EH4 and EH5)and a co...Pinus elliottii×P.caribaea is a widely planted commercial tree hybrid in South China.To investigate the potential of physiological parameters for clonal selection,cuttings of three clones(EH3,EH4 and EH5)and a control were grown in phosphorus treated pots.Significant variations to phosphorous,photosystem II activity and polar metabolite abundance in needles were noted among clones.Clone EH5 was the most P-responsive and had maximum height growth.The highest maximum quantum yield of PSII in the dark(F_(v)/F_(m)),maximum quantum yield of PSII in the light(F_(v)'/F_(m)')and the actual PSII efficiency(Φ_(PSII))values were also found in EH5.A total of 64 polar metabolites were identified,21 were regulated by phosphorous,while 28 accumulated differentially among the three clones.There were few overlapping responsive metabolites to phosphorous fertilization.In EH5,the abundance of maltotriitol,neohesperidin and raffinose were highest,whereas galactinol and shikimic acid were lower compared with EH3 and EH4.The results reveal that physiological traits were genetically controlled and might be useful for selecting clones with high phosphorous utilization efficiency.展开更多
Bauxite deposits are studied because of their economic value and because they play an important role in the study of paleoclimate and paleogeography of continents. They provide a rare record of the weathering and evol...Bauxite deposits are studied because of their economic value and because they play an important role in the study of paleoclimate and paleogeography of continents. They provide a rare record of the weathering and evolution of continental surfaces. Geomicrobiological analysis makes it possible to verify that microorganisms have played a critical role during the formation of bauxite with the possibility already intimated in previous studies. Ambient temperature, abundance of water, organic carbon and bioavailable iron and other metal substrates provide a suitable environment for microbes to inhabit. Thiobacillus, Leptospirilum, Thermophilic bacteria and Heterotrophs have been shown to be able to oxidize ferrous iron and to reduce sulfate-generating sulfuric acid, which can accelerate the weathering of aluminosilicates and precipitation of iron oxyhydroxides. Microorganisms referred to the genus Bacillus can mediate the release of alkaline metals. Although the dissimilatory iron-reducing and sulfate-reducing bacteria in bauxites have not yet been identified, some recorded authigenic carbonates and ＂bacteriopyrites＂ that appear to be unique in morphology and grain size might record microbial activity. Typical bauxite minerals such as gibbsite, kaolinite, covellite, galena, pyrite, zircon, calcium plagioclase, orthoclase, and albite have been investigated as part of an analysis of microbial mediation. The paleoecology of such bauxitic microorganisms inhabiting continental （sub） surfaces, revealed through geomicrobiological analysis, will add a further dimension to paleoclimatic and paleoenvironmental studies.展开更多
Because overexpression of Vitreoscilla hemoglobin gene(Vgb)gene in plants can enhance tolerance to waterlogging,here Vgb was inserted into Populus alba×glandulosa to investigate its expression and effects on grow...Because overexpression of Vitreoscilla hemoglobin gene(Vgb)gene in plants can enhance tolerance to waterlogging,here Vgb was inserted into Populus alba×glandulosa to investigate its expression and effects on growth and physiological responses to waterlogging stress in the transgenic poplars.Southern blotting and RT-PCR analysis of Vgb-transgenic P.alba×glandulosa showed that the Vgb gene was integrated into the genome of the V13-81 and V13-85 transgenic lines and expressed.In greenhouse waterlogging stress tests,mortality of the transgenic poplar was significant lower than that of nontransgenic plants with increasing treatment time from 2 to 22 days.The transgenic plants had higher chlorophyll content and less chloroplast damage than in the control plants.Additionally,starch accumulation increased,and growth was enhanced in the transgenic plants,suggesting that the Vgb-expressing lines had improved energy reserves.Field trials of the transgenic poplar suggested that Vgb expression promotes growth and influences wood quality.Taken together,our results suggest that the expression of Vgb can increase the accumulation of chlorophyll and starch in the transgenic poplar,improve its ability to endure flooding,and improve growth and wood quality of the transgenic plants.展开更多
Boolean networks(BNs)introduced by Kauffman in[1]are of great significance in the description of gene interactions/evolutions in genetic regulatory networks.The regulation of genes can be achieved by adding external i...Boolean networks(BNs)introduced by Kauffman in[1]are of great significance in the description of gene interactions/evolutions in genetic regulatory networks.The regulation of genes can be achieved by adding external inputs into BNs.Consequently,Boolean control networks(BCNs)were established in[2].展开更多
Unsupervised learning methods were applied to explore data patterns in multivariate geophysical datasets collected from ocean floor sediment core samples coming from scientific ocean drilling in the South China Sea.Co...Unsupervised learning methods were applied to explore data patterns in multivariate geophysical datasets collected from ocean floor sediment core samples coming from scientific ocean drilling in the South China Sea.Compared to studies on similar datasets,but using supervised learning methods which are designed to make predictions based on sample training data,unsupervised learning methods require no a priori information and focus only on the input data.In this study,popular unsupervised learning methods including K-means,self-organizing maps,hierarchical clustering and random forest were coupled with different distance metrics to form exploratory data clusters.The resulting data clusters were externally validated with lithologic units and geologic time scales assigned to the datasets by conventional methods. Compact and connected data clusters displayed varying degrees of correspondence with existing classification by lithologic units and geologic time scales.K-means and self-organizing maps were observed to perform better with lithologic units while random forest corresponded best with geologic time scales.This study sets a pioneering example of how unsupervised machine learning methods can be used as an automatic processing tool for the increasingly high volume of scientific ocean drilling data.展开更多
Objective:To develop and synthesize a novel derivative of ethyl pyruvate,named TZC02,and investigate its radioprotective effects against ionizing radiation(IR)-induced intestinal injury in mice.Methods:Male C57BL/6J m...Objective:To develop and synthesize a novel derivative of ethyl pyruvate,named TZC02,and investigate its radioprotective effects against ionizing radiation(IR)-induced intestinal injury in mice.Methods:Male C57BL/6J mice weighing(20±2)g in the survival experiment were randomly divided into five groups(n=10 in each):control group,IR group,IR+TZC02(50 mg/kg)group,IR+TZC02(100 mg/kg)group,and IR+TZC02(200 mg/kg)group.Mice's survival rates were monitored for 7 d.In other experiments,the male mice were randomly divided into three groups(n=5 per group):control group,IR group,and IR+TZC02(100 mg/kg)group.TZC02 was intragastrically administered 1 h before 12 Gy abdominalγ-ray irradiation(ABI)and 24 h,48 h after irradiation,respectively.Three days after IR exposure,small intestinal tissues were collected and the number of small intestinal crypts was determined using hematoxylin&eosin(H&E)staining.Immunohistochemical analysis was used to assess the regenerative capacity of the small intestine(SI)and radiation-induced damage,stemness markers or DNA repair surrogates,including Ki67,lysozyme,and villus.The expressions of histone H2AX phosphorylation(γH2AX)and caspase-3 were evaluated through immunofluorescence analyses.Additionally,in vitro cultured small intestinal organoids were employed to investigate the effects of TZC02 on SI regeneration after irradiation.Results:The administration of TZC02 significantly improved the 7 d-survival rate of mice exposed to 12 Gy ABI(P<0.05).Compared to the IR group,TZC02 treatment attenuated the decrease of SI Ki67-positive cells[(59.60±6.33)vs.(37.70±7.82),t=11.89,P<0.0001]and Paneth cells[(9.90±1.37)vs.(5.50±1.71),t=6.02,P<0.001]in five crypts,and reduced structural damage to the SI[villus height,(349.49±60.17)μm vs.(294.72±40.09)μm;t=3.39;P<0.05].TZC02 also significantly decreased the crypt apoptosis detected by caspase-3[(10.75±1.26)vs.(29.83±2.56),t=13.39,P<0.0001]and DNA damage detected by gH2AX[(10.40±1.14)vs.(29.60±2.70),t=10.13,P<0.0001].The organoid survival 7 d post-irradiation further confirmed the protective effects of TZC02(area of organoids,(0.119±0.081)mm^(2)vs.(0.080±0.037)mm^(2);t=2.30;P<0.05).Conclusions:This study demonstrate that TZC02 can offer effective protection against IR-induced intestinal injury,suggesting its potential as a promising protective compound for patients treated with radiotherapy.展开更多
Oxygen isotope analyses were carried out by the laserprobe technique for mineral separates from mantle xenolith and megacryst in Cenozoic basalts, East China. The results not only give the δ I8O range consistent with...Oxygen isotope analyses were carried out by the laserprobe technique for mineral separates from mantle xenolith and megacryst in Cenozoic basalts, East China. The results not only give the δ I8O range consistent with that reported for peridotites in the world, but also yield oxygen isotope equilibrium between coexisting minerals.展开更多
Unsupervised machine learning methods were applied on multivariate geophysical and geochemical datasets of ocean floor sediment cores collected from the South China Sea. The well-preserved and continuous core samples ...Unsupervised machine learning methods were applied on multivariate geophysical and geochemical datasets of ocean floor sediment cores collected from the South China Sea. The well-preserved and continuous core samples comprising high resolution Cenozoic sediment records enable scientists to carry out paleoenvironment studies in detail. Bayesian age-depth chronological models constructed from biostratigraphic control points for the drilling sites are applied on cluster boundaries generated from two popular unsupervised learning methods: K-means and random forest. The unsupervised learning methods experimented have produced compact and unambiguous clusters from the datasets, indicating that previously unknown data patterns can be revealed when all variables from the datasets are taken into account simultaneously. A study of synchroneity of past events represented by the cluster boundaries across geographically separated ocean drilling sites is achieved through converting the fixed depths of cluster boundaries into chronological ranges represented by Gaussian density plots which are then compared with known past events in the region. A Gaussian density peak at around 7.2 Ma has been identified from results of all three sites and it is suggested to coincide with the initiation of the East Asian monsoon. Contrary to traditional statistical approach, a priori assumptions are not required for unsupervised learning, and the clustering results serve as a novel data-driven proxy for studying the complex and dynamic processes of the paleoenvironment surrounding the ocean sediment. This work serves as a pioneering approach to extract valuable information of regional events and opens up a systematic and objective way to study the vast global ocean sediment datasets.展开更多
This is a report of carbon isotope anomaly in marbles associated with the UHP eclogites from the Dabie Mountains. The results place constraints on the degree of crust_mantle interaction during the UHP metamorphism.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB41000000)the Fundamental Research Funds for the Central Universities(WK2080000144)。
文摘Araneiforms are spider-like ground patterns that are widespread in the southern polar regions of Mars.A gas erosion process driven by the seasonal sublimation of CO_(2) ice was proposed as an explanation for their formation,which cannot occur on Earth due to the high climatic temperature.In this study,we propose an alternative mechanism that attrib-utes the araneiform formation to the erosion of upwelling salt water from the subsurface,relying on the identification of the first terrestrial analog found in a playa of the Qaidam Basin on the northern Tibetan Plateau.Morphological analysis indicates that the structures in the Qaidam Basin have fractal features comparable to araneiforms on Mars.A numerical model is developed to investigate the araneiform formation driven by the water-diffusion mechanism.The simulation res-ults indicate that the water-diffusion process,under varying ground conditions,may be responsible for the diverse aranei-form morphologies observed on both Earth and Mars.Our numerical simulations also demonstrate that the orientations of the saltwater diffusion networks are controlled by pre-existing polygonal cracks,which is consistent with observations of araneiforms on Mars and Earth.Our study thus suggests that a saltwater-related origin of the araneiform is possible and has significant implications for water searches on Mars.
基金funded by the Science and Technology Planning Project of Guangdong Province(2017B020205003)the Natural Science Foundation of Guangdong Province(2014A030313657)。
文摘Pinus elliottii×P.caribaea is a widely planted commercial tree hybrid in South China.To investigate the potential of physiological parameters for clonal selection,cuttings of three clones(EH3,EH4 and EH5)and a control were grown in phosphorus treated pots.Significant variations to phosphorous,photosystem II activity and polar metabolite abundance in needles were noted among clones.Clone EH5 was the most P-responsive and had maximum height growth.The highest maximum quantum yield of PSII in the dark(F_(v)/F_(m)),maximum quantum yield of PSII in the light(F_(v)'/F_(m)')and the actual PSII efficiency(Φ_(PSII))values were also found in EH5.A total of 64 polar metabolites were identified,21 were regulated by phosphorous,while 28 accumulated differentially among the three clones.There were few overlapping responsive metabolites to phosphorous fertilization.In EH5,the abundance of maltotriitol,neohesperidin and raffinose were highest,whereas galactinol and shikimic acid were lower compared with EH3 and EH4.The results reveal that physiological traits were genetically controlled and might be useful for selecting clones with high phosphorous utilization efficiency.
基金supported by the Hong Kong University General Research Fund HKU703008P on‘Planetary Evolution of Ferric Iron Metabolism
文摘Bauxite deposits are studied because of their economic value and because they play an important role in the study of paleoclimate and paleogeography of continents. They provide a rare record of the weathering and evolution of continental surfaces. Geomicrobiological analysis makes it possible to verify that microorganisms have played a critical role during the formation of bauxite with the possibility already intimated in previous studies. Ambient temperature, abundance of water, organic carbon and bioavailable iron and other metal substrates provide a suitable environment for microbes to inhabit. Thiobacillus, Leptospirilum, Thermophilic bacteria and Heterotrophs have been shown to be able to oxidize ferrous iron and to reduce sulfate-generating sulfuric acid, which can accelerate the weathering of aluminosilicates and precipitation of iron oxyhydroxides. Microorganisms referred to the genus Bacillus can mediate the release of alkaline metals. Although the dissimilatory iron-reducing and sulfate-reducing bacteria in bauxites have not yet been identified, some recorded authigenic carbonates and ＂bacteriopyrites＂ that appear to be unique in morphology and grain size might record microbial activity. Typical bauxite minerals such as gibbsite, kaolinite, covellite, galena, pyrite, zircon, calcium plagioclase, orthoclase, and albite have been investigated as part of an analysis of microbial mediation. The paleoecology of such bauxitic microorganisms inhabiting continental （sub） surfaces, revealed through geomicrobiological analysis, will add a further dimension to paleoclimatic and paleoenvironmental studies.
基金supported by the Basic Research Fund of RIF(Grant No.CAFYBB2017ZA001-3)the National Natural Science Foundation of China(Grant No.31700589)the Forestry Genetic Breeding National Key Laboratory(Chinese Academy of Forestry Sciences)Open Project(Grant No.TGB 2013005).
文摘Because overexpression of Vitreoscilla hemoglobin gene(Vgb)gene in plants can enhance tolerance to waterlogging,here Vgb was inserted into Populus alba×glandulosa to investigate its expression and effects on growth and physiological responses to waterlogging stress in the transgenic poplars.Southern blotting and RT-PCR analysis of Vgb-transgenic P.alba×glandulosa showed that the Vgb gene was integrated into the genome of the V13-81 and V13-85 transgenic lines and expressed.In greenhouse waterlogging stress tests,mortality of the transgenic poplar was significant lower than that of nontransgenic plants with increasing treatment time from 2 to 22 days.The transgenic plants had higher chlorophyll content and less chloroplast damage than in the control plants.Additionally,starch accumulation increased,and growth was enhanced in the transgenic plants,suggesting that the Vgb-expressing lines had improved energy reserves.Field trials of the transgenic poplar suggested that Vgb expression promotes growth and influences wood quality.Taken together,our results suggest that the expression of Vgb can increase the accumulation of chlorophyll and starch in the transgenic poplar,improve its ability to endure flooding,and improve growth and wood quality of the transgenic plants.
基金This work was supported by the National Natural Science Foundation of China(62273201)the Research Fund for the Taishan Scholar Project of Shandong Province of China(tstp20221103)the Natural Science Foundation of Shandong Province(ZR2022QE267).
文摘Boolean networks(BNs)introduced by Kauffman in[1]are of great significance in the description of gene interactions/evolutions in genetic regulatory networks.The regulation of genes can be achieved by adding external inputs into BNs.Consequently,Boolean control networks(BCNs)were established in[2].
文摘Unsupervised learning methods were applied to explore data patterns in multivariate geophysical datasets collected from ocean floor sediment core samples coming from scientific ocean drilling in the South China Sea.Compared to studies on similar datasets,but using supervised learning methods which are designed to make predictions based on sample training data,unsupervised learning methods require no a priori information and focus only on the input data.In this study,popular unsupervised learning methods including K-means,self-organizing maps,hierarchical clustering and random forest were coupled with different distance metrics to form exploratory data clusters.The resulting data clusters were externally validated with lithologic units and geologic time scales assigned to the datasets by conventional methods. Compact and connected data clusters displayed varying degrees of correspondence with existing classification by lithologic units and geologic time scales.K-means and self-organizing maps were observed to perform better with lithologic units while random forest corresponded best with geologic time scales.This study sets a pioneering example of how unsupervised machine learning methods can be used as an automatic processing tool for the increasingly high volume of scientific ocean drilling data.
基金funded by the National Nature Science Foundation of China(81972975)the CAMS Medicine and Health Technology Innovation Project(2021-I2M-1-060,2021-RC310-010)+1 种基金the Major Program of Applied Basic Research Projects of Tianjin(22JCZDJC00430)the Natural Science Foundation of Tianjin City(20JCYBJC00250),China.
文摘Objective:To develop and synthesize a novel derivative of ethyl pyruvate,named TZC02,and investigate its radioprotective effects against ionizing radiation(IR)-induced intestinal injury in mice.Methods:Male C57BL/6J mice weighing(20±2)g in the survival experiment were randomly divided into five groups(n=10 in each):control group,IR group,IR+TZC02(50 mg/kg)group,IR+TZC02(100 mg/kg)group,and IR+TZC02(200 mg/kg)group.Mice's survival rates were monitored for 7 d.In other experiments,the male mice were randomly divided into three groups(n=5 per group):control group,IR group,and IR+TZC02(100 mg/kg)group.TZC02 was intragastrically administered 1 h before 12 Gy abdominalγ-ray irradiation(ABI)and 24 h,48 h after irradiation,respectively.Three days after IR exposure,small intestinal tissues were collected and the number of small intestinal crypts was determined using hematoxylin&eosin(H&E)staining.Immunohistochemical analysis was used to assess the regenerative capacity of the small intestine(SI)and radiation-induced damage,stemness markers or DNA repair surrogates,including Ki67,lysozyme,and villus.The expressions of histone H2AX phosphorylation(γH2AX)and caspase-3 were evaluated through immunofluorescence analyses.Additionally,in vitro cultured small intestinal organoids were employed to investigate the effects of TZC02 on SI regeneration after irradiation.Results:The administration of TZC02 significantly improved the 7 d-survival rate of mice exposed to 12 Gy ABI(P<0.05).Compared to the IR group,TZC02 treatment attenuated the decrease of SI Ki67-positive cells[(59.60±6.33)vs.(37.70±7.82),t=11.89,P<0.0001]and Paneth cells[(9.90±1.37)vs.(5.50±1.71),t=6.02,P<0.001]in five crypts,and reduced structural damage to the SI[villus height,(349.49±60.17)μm vs.(294.72±40.09)μm;t=3.39;P<0.05].TZC02 also significantly decreased the crypt apoptosis detected by caspase-3[(10.75±1.26)vs.(29.83±2.56),t=13.39,P<0.0001]and DNA damage detected by gH2AX[(10.40±1.14)vs.(29.60±2.70),t=10.13,P<0.0001].The organoid survival 7 d post-irradiation further confirmed the protective effects of TZC02(area of organoids,(0.119±0.081)mm^(2)vs.(0.080±0.037)mm^(2);t=2.30;P<0.05).Conclusions:This study demonstrate that TZC02 can offer effective protection against IR-induced intestinal injury,suggesting its potential as a promising protective compound for patients treated with radiotherapy.
文摘Oxygen isotope analyses were carried out by the laserprobe technique for mineral separates from mantle xenolith and megacryst in Cenozoic basalts, East China. The results not only give the δ I8O range consistent with that reported for peridotites in the world, but also yield oxygen isotope equilibrium between coexisting minerals.
文摘Unsupervised machine learning methods were applied on multivariate geophysical and geochemical datasets of ocean floor sediment cores collected from the South China Sea. The well-preserved and continuous core samples comprising high resolution Cenozoic sediment records enable scientists to carry out paleoenvironment studies in detail. Bayesian age-depth chronological models constructed from biostratigraphic control points for the drilling sites are applied on cluster boundaries generated from two popular unsupervised learning methods: K-means and random forest. The unsupervised learning methods experimented have produced compact and unambiguous clusters from the datasets, indicating that previously unknown data patterns can be revealed when all variables from the datasets are taken into account simultaneously. A study of synchroneity of past events represented by the cluster boundaries across geographically separated ocean drilling sites is achieved through converting the fixed depths of cluster boundaries into chronological ranges represented by Gaussian density plots which are then compared with known past events in the region. A Gaussian density peak at around 7.2 Ma has been identified from results of all three sites and it is suggested to coincide with the initiation of the East Asian monsoon. Contrary to traditional statistical approach, a priori assumptions are not required for unsupervised learning, and the clustering results serve as a novel data-driven proxy for studying the complex and dynamic processes of the paleoenvironment surrounding the ocean sediment. This work serves as a pioneering approach to extract valuable information of regional events and opens up a systematic and objective way to study the vast global ocean sediment datasets.
文摘This is a report of carbon isotope anomaly in marbles associated with the UHP eclogites from the Dabie Mountains. The results place constraints on the degree of crust_mantle interaction during the UHP metamorphism.
