Invasive species generally possess unique characteristics that allow them to survive the invasion process in order to es- tablish and spread in new habitats. Successful invaders must resist both physical and physiolog...Invasive species generally possess unique characteristics that allow them to survive the invasion process in order to es- tablish and spread in new habitats. Successful invaders must resist both physical and physiological stresses associated with the changing environment. A common littoral barnacle, Chthamalus challengeri Hoek, 1883 （Crustacea, Cirripedia）, which is native to Japan, South Korea and northern China, has become established in the high-littoral zone adjacent to Yangshan Port, Shanghai, China. A comparison of the morphology of Chthamlus species from Zhoushan archipelago with previous description indicates the occur- rence of C. challengeri. The new immigrant becomes a dominant species in certain high-intertidal habitats of the adjacent area to of Yangshan Port. C. challengeri was found in part of sampling sites in Zhoushan in 2010; however, it dispersed to all the eleven sam- piing sites in 2012. Densities of C.challengeri had increased over 10 times in the last 2 years, with the highest mean value reaching 39533 ± 6243 ind. m-2 in the new habitat. The specific ratios of both operculum area （Sa） to base area （SA） and average height of pa- rietal plates （H） to length of base （L） revealed that C. challengeri displays morphological changes to resist stronger currents in the new habitats for invasion.展开更多
AIM： To characterize the types of mutations present in the 23S rRNA genes of Malaysian isolates of clarithromycin-resistant Helicobacter pylori （H pylorl~. METHODS： Clarithromycin susceptibility of H pylori isolate...AIM： To characterize the types of mutations present in the 23S rRNA genes of Malaysian isolates of clarithromycin-resistant Helicobacter pylori （H pylorl~. METHODS： Clarithromycin susceptibility of H pylori isolates was determined by E test. Analyses for point mutations in the domain V of 23S rRNA genes in clarithromycin-resistant and -sensitive strains were performed by sequence analysis of amplified polymerase chain reaction products. Restriction fragment length polymorphism was performed using Bsa I and MboI enzymes to detect restriction sites that correspond to the mutations in the clarithromycin- resistant strains. RESULTS： Of 187 isolates from 120 patients, four were resistant to clarithromycin, while 183 were sensitive. The MIC of the resistant strains ranged from 1.5 to 24 pg/mL. Two isolates had an A2142G mutation and another two had A2143G mutations. A T2182C mutation was detected in two out of four clarithromycin-resistant isolates and in 13 of 14 clarithromycin-sensitive isolates. Restriction enzyme analyses with Bsa I and Mbo I were able to detect the mutations. CONCLUSION： Clarithromycin resistance is an uncommon occurrence among Malaysian isolates of Hpylori strains and the mutations A2142G and A2143G detected were associated with low-level resistance.展开更多
Invasive plants are a major threat to biodiversity and may adversely affect food security.Clonal integration enables the sharing of resources between connected ramets and can enhance plant performance in many invasive...Invasive plants are a major threat to biodiversity and may adversely affect food security.Clonal integration enables the sharing of resources between connected ramets and can enhance plant performance in many invasive species.However,few studies have examined the role of clonal integration when weeds are exposed to plant growth regulators(PGRs).PGRs are used extensively in agriculture and may affect nearby weeds through soil leaching,erosion and runoff.Our aim was to investigate the effects of clonal integration on growth in a noxious weed,Alternanthera philoxeroides(alligator weed),in response to two PGRs frequently used in agriculture,gibberellins(GAs)and paclobutrazol(PAC).Ramets of A.philoxeroides were propagated in the greenhouse,and treated with PGRs.PGRs were applied to the older ramets(i.e.‘basal’part),with half of the plants having the stems between the apical(younger)and basal parts left connected,while the remaining plants had the stems between the two parts severed.Following the growing period,plants were measured for growth traits.We found that GA and PAC had contrasting effects on plant growth.GA significantly promoted above-ground growth of the apical ramets via clonal integration.Alternatively,PAC inhibited above-ground growth in the basal and apical parts,and enhanced below-ground growth of the basal and apical ramets through clonal integration.Our results highlight how clonal integration can promote growth in A.philoxeroides following the application of PGRs,which is likely an important mechanism for this species to invade new environments.展开更多
The North China Craton(NCC) hosts numerous gold deposits and is known as the most gold-productive region of China. The gold deposits were mostly formed within a few million years in the Early Cretaceous(130–120 Ma), ...The North China Craton(NCC) hosts numerous gold deposits and is known as the most gold-productive region of China. The gold deposits were mostly formed within a few million years in the Early Cretaceous(130–120 Ma), coeval with widespread occurrences of bimodal magmatism, rift basins and metamorphic core complexes that marked the peak of lithospheric thinning and destruction of the NCC. Stable isotope data and geological evidence indicate that ore-forming fluids and other components were largely exsolved from cooling magma and/or derived from mantle degassing during the period of lithospheric extension. Gold mineralization in the NCC contrasts strikingly with that of other cratons where gold ore-forming fluids were sourced mostly from metamorphic devolatization in compressional or transpressional regimes. In this paper, we present a summary and discussion on time-space distribution and ore genesis of gold deposits in the NCC in the context of the timing, spatial variation, and decratonic processes. Compared with orogenic gold deposits in other cratonic blocks, the Early Cretaceous gold deposits in the NCC are quite distinct in that they were deposited from magma-derived fluids under extensional settings and associated closely with destruction of cratonic lithosphere. We argue that Early Cretaceous gold deposits in the NCC cannot be classified as orogenic gold deposits as previously suggested, rather, they are a new type of gold deposits, termed as "decratonic gold deposits" in this study. The westward subduction of the paleo-West Pacific plate(the Izanagi plate) beneath the eastern China continent gave rise to an optimal tectonic setting for large-scale gold mineralization in the Early Cretaceous. Dehydration of the subducted and stagnant slab in the mantle transition zone led to continuous hydration and considerable metasomatism of the mantle wedge beneath the NCC. As a consequence, the refractory mantle became oxidized and highly enriched in large ion lithophile elements and chalcophile elements(e.g., Cu, Au, Ag and Te). Partial melting of such a mantle would have produced voluminous hydrous, Au- and S-bearing basaltic magma, which, together with crust-derived melts induced by underplating of basaltic magma, served as an important source for ore-forming fluids. It is suggested that the Eocene Carlin-type gold deposits in Nevada, occurring geologically in the deformed western margin of the North America Craton, are comparable with the Early Cretaceous gold deposits of the NCC because they share similar tectonic settings and auriferous fluids. The NCC gold deposits are characterized by gold-bearing quartz veins in the Archean amphibolite facies rocks, whereas the Nevada gold deposits are featured by fine-grained sulfide dissemination in Paleozoic marine sedimentary rocks. Their main differences in gold mineralization are the different host rocks, ore-controlling structures, and ore-forming depth. The similar tectonic setting and ore-forming fluid source, however, indicate that the Carlin-type gold deposits in Nevada are actually analogous to decratonic gold deposits in the NCC. Gold deposits in both the NCC and Nevada were formed in a relatively short time interval(<10 Myr) and become progressively younger toward the subduction zone. Younging of gold mineralization toward subduction zone might have been attributed to retreat of subduction zone and rollback of subducted slab. According to the ages of gold deposits on inland and marginal zones, the retreat rates of the Izanagi plate in the western Pacific in the Early Cretaceous and the Farallon plate of the eastern Pacific in the Eocene are estimated at 8.8 cm/yr and 3.3 cm/yr, respectively.展开更多
This article combines with the author＇s academic experience, especially the papers he has published in Zhongguo Shehui Kexue （中国社会科学） in recent years, to discuss the extremely important role of the journal in...This article combines with the author＇s academic experience, especially the papers he has published in Zhongguo Shehui Kexue （中国社会科学） in recent years, to discuss the extremely important role of the journal in creatively advancing the study of Marx＇s philosophy. This progress is mainly evident in three respects： a new understanding of the essence of Marx＇s philosophy; a new exploration of its historical development; and new reflections on its origins.展开更多
Members of the Chinese delegation celebrate after Beijing wins the bid to host the 2022 Winter Olympics at the128th Session of the International Olympic Committee in Kuala Lumpur,Malaysia,on July 31.Beijing beat its o...Members of the Chinese delegation celebrate after Beijing wins the bid to host the 2022 Winter Olympics at the128th Session of the International Olympic Committee in Kuala Lumpur,Malaysia,on July 31.Beijing beat its only competitor Almaty,Kazakhstan,by 44 votes to 40 with one abstention.President Xi Jinping expressed Chinese people’s passion for the Winter Games in a video message during Beijing’s presentation.The Chinese capital launched a joint bid for the Games in November 2013 with Zhangjiakou in neighboring Hebei Province.It becomes the first city in the world to host both the Summer and Winter Olympics.展开更多
基金supported by China’s National Special Research Fund for Non-Profit Marine Sector (No. 2013418027)Marine Biology Program of Shanghai Leading Academic Disipline (No. J50701)+1 种基金Marine Special Fund of Shanghai Committee of Science and Technology (No. 11dz1205000)a Doctoral Research Fund from Shanghai Ocean University (No. A2-0302-14-300084)
文摘Invasive species generally possess unique characteristics that allow them to survive the invasion process in order to es- tablish and spread in new habitats. Successful invaders must resist both physical and physiological stresses associated with the changing environment. A common littoral barnacle, Chthamalus challengeri Hoek, 1883 （Crustacea, Cirripedia）, which is native to Japan, South Korea and northern China, has become established in the high-littoral zone adjacent to Yangshan Port, Shanghai, China. A comparison of the morphology of Chthamlus species from Zhoushan archipelago with previous description indicates the occur- rence of C. challengeri. The new immigrant becomes a dominant species in certain high-intertidal habitats of the adjacent area to of Yangshan Port. C. challengeri was found in part of sampling sites in Zhoushan in 2010; however, it dispersed to all the eleven sam- piing sites in 2012. Densities of C.challengeri had increased over 10 times in the last 2 years, with the highest mean value reaching 39533 ± 6243 ind. m-2 in the new habitat. The specific ratios of both operculum area （Sa） to base area （SA） and average height of pa- rietal plates （H） to length of base （L） revealed that C. challengeri displays morphological changes to resist stronger currents in the new habitats for invasion.
基金Supported by A grant from the Ministry of Science,Technology and Innovation,Malaysia
文摘AIM： To characterize the types of mutations present in the 23S rRNA genes of Malaysian isolates of clarithromycin-resistant Helicobacter pylori （H pylorl~. METHODS： Clarithromycin susceptibility of H pylori isolates was determined by E test. Analyses for point mutations in the domain V of 23S rRNA genes in clarithromycin-resistant and -sensitive strains were performed by sequence analysis of amplified polymerase chain reaction products. Restriction fragment length polymorphism was performed using Bsa I and MboI enzymes to detect restriction sites that correspond to the mutations in the clarithromycin- resistant strains. RESULTS： Of 187 isolates from 120 patients, four were resistant to clarithromycin, while 183 were sensitive. The MIC of the resistant strains ranged from 1.5 to 24 pg/mL. Two isolates had an A2142G mutation and another two had A2143G mutations. A T2182C mutation was detected in two out of four clarithromycin-resistant isolates and in 13 of 14 clarithromycin-sensitive isolates. Restriction enzyme analyses with Bsa I and Mbo I were able to detect the mutations. CONCLUSION： Clarithromycin resistance is an uncommon occurrence among Malaysian isolates of Hpylori strains and the mutations A2142G and A2143G detected were associated with low-level resistance.
基金supported by National Natural Science Foundation of China(32171509,32071905,32071521,32001087)the Natural Science Foundation of Jiangsu(BK20211321)+2 种基金Jiangsu Planned Projects for Postdoctoral Research Funds(2021K160B)Jiangsu University Research Foundation(20JDG055)Part of the funding for this research was supported by Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Invasive plants are a major threat to biodiversity and may adversely affect food security.Clonal integration enables the sharing of resources between connected ramets and can enhance plant performance in many invasive species.However,few studies have examined the role of clonal integration when weeds are exposed to plant growth regulators(PGRs).PGRs are used extensively in agriculture and may affect nearby weeds through soil leaching,erosion and runoff.Our aim was to investigate the effects of clonal integration on growth in a noxious weed,Alternanthera philoxeroides(alligator weed),in response to two PGRs frequently used in agriculture,gibberellins(GAs)and paclobutrazol(PAC).Ramets of A.philoxeroides were propagated in the greenhouse,and treated with PGRs.PGRs were applied to the older ramets(i.e.‘basal’part),with half of the plants having the stems between the apical(younger)and basal parts left connected,while the remaining plants had the stems between the two parts severed.Following the growing period,plants were measured for growth traits.We found that GA and PAC had contrasting effects on plant growth.GA significantly promoted above-ground growth of the apical ramets via clonal integration.Alternatively,PAC inhibited above-ground growth in the basal and apical parts,and enhanced below-ground growth of the basal and apical ramets through clonal integration.Our results highlight how clonal integration can promote growth in A.philoxeroides following the application of PGRs,which is likely an important mechanism for this species to invade new environments.
基金financially supported by the National Natural Science Foundation of China(Grant No.91414301)project of the State Key Laboratory of Lithospheric Evolution(Grant No.1303)
文摘The North China Craton(NCC) hosts numerous gold deposits and is known as the most gold-productive region of China. The gold deposits were mostly formed within a few million years in the Early Cretaceous(130–120 Ma), coeval with widespread occurrences of bimodal magmatism, rift basins and metamorphic core complexes that marked the peak of lithospheric thinning and destruction of the NCC. Stable isotope data and geological evidence indicate that ore-forming fluids and other components were largely exsolved from cooling magma and/or derived from mantle degassing during the period of lithospheric extension. Gold mineralization in the NCC contrasts strikingly with that of other cratons where gold ore-forming fluids were sourced mostly from metamorphic devolatization in compressional or transpressional regimes. In this paper, we present a summary and discussion on time-space distribution and ore genesis of gold deposits in the NCC in the context of the timing, spatial variation, and decratonic processes. Compared with orogenic gold deposits in other cratonic blocks, the Early Cretaceous gold deposits in the NCC are quite distinct in that they were deposited from magma-derived fluids under extensional settings and associated closely with destruction of cratonic lithosphere. We argue that Early Cretaceous gold deposits in the NCC cannot be classified as orogenic gold deposits as previously suggested, rather, they are a new type of gold deposits, termed as "decratonic gold deposits" in this study. The westward subduction of the paleo-West Pacific plate(the Izanagi plate) beneath the eastern China continent gave rise to an optimal tectonic setting for large-scale gold mineralization in the Early Cretaceous. Dehydration of the subducted and stagnant slab in the mantle transition zone led to continuous hydration and considerable metasomatism of the mantle wedge beneath the NCC. As a consequence, the refractory mantle became oxidized and highly enriched in large ion lithophile elements and chalcophile elements(e.g., Cu, Au, Ag and Te). Partial melting of such a mantle would have produced voluminous hydrous, Au- and S-bearing basaltic magma, which, together with crust-derived melts induced by underplating of basaltic magma, served as an important source for ore-forming fluids. It is suggested that the Eocene Carlin-type gold deposits in Nevada, occurring geologically in the deformed western margin of the North America Craton, are comparable with the Early Cretaceous gold deposits of the NCC because they share similar tectonic settings and auriferous fluids. The NCC gold deposits are characterized by gold-bearing quartz veins in the Archean amphibolite facies rocks, whereas the Nevada gold deposits are featured by fine-grained sulfide dissemination in Paleozoic marine sedimentary rocks. Their main differences in gold mineralization are the different host rocks, ore-controlling structures, and ore-forming depth. The similar tectonic setting and ore-forming fluid source, however, indicate that the Carlin-type gold deposits in Nevada are actually analogous to decratonic gold deposits in the NCC. Gold deposits in both the NCC and Nevada were formed in a relatively short time interval(<10 Myr) and become progressively younger toward the subduction zone. Younging of gold mineralization toward subduction zone might have been attributed to retreat of subduction zone and rollback of subducted slab. According to the ages of gold deposits on inland and marginal zones, the retreat rates of the Izanagi plate in the western Pacific in the Early Cretaceous and the Farallon plate of the eastern Pacific in the Eocene are estimated at 8.8 cm/yr and 3.3 cm/yr, respectively.
文摘This article combines with the author＇s academic experience, especially the papers he has published in Zhongguo Shehui Kexue （中国社会科学） in recent years, to discuss the extremely important role of the journal in creatively advancing the study of Marx＇s philosophy. This progress is mainly evident in three respects： a new understanding of the essence of Marx＇s philosophy; a new exploration of its historical development; and new reflections on its origins.
文摘Members of the Chinese delegation celebrate after Beijing wins the bid to host the 2022 Winter Olympics at the128th Session of the International Olympic Committee in Kuala Lumpur,Malaysia,on July 31.Beijing beat its only competitor Almaty,Kazakhstan,by 44 votes to 40 with one abstention.President Xi Jinping expressed Chinese people’s passion for the Winter Games in a video message during Beijing’s presentation.The Chinese capital launched a joint bid for the Games in November 2013 with Zhangjiakou in neighboring Hebei Province.It becomes the first city in the world to host both the Summer and Winter Olympics.
