The negative effects of habitat loss on biodiversity are undisputed,while the effect of habitat configuration,i.e.,the spatial arrangement of habitat area,has been debated for decades.To develop a more comprehensive u...The negative effects of habitat loss on biodiversity are undisputed,while the effect of habitat configuration,i.e.,the spatial arrangement of habitat area,has been debated for decades.To develop a more comprehensive understanding,it is important to know when and how configuration matters.In this study,we tested whether forest configuration influences the richness of species in groups characterized by varying shade tolerance in different ways and how such effects are related to habitat amount(i.e.,the percentage of forest cover)at the landscape scale.Based on 104 survey plots(each measuring 1km^(2))of vascular plants on the Swiss Plateau,and using two statistical approaches(i.e.,multiple regression and path analysis),we modeled the effects of habitat amount and configuration(measured as number of forest patches,total edge length,and proximity index)across all the plots and separately for three habitat amount classes:<10%,10%–30%,and>30%forest cover.When we modeled all plots together,we found that,after controlling for habitat amount,the forest configuration significantly affected species richness.When we considered the different habitat amount classes separately,most of the significant effects of habitat configuration on species richness occurred only for habitat amounts of<10%forest cover.Additionally,the response to forest configuration differed among species with different shade tolerances.When forest area was<10%,the effects of the number of patches and the total edge length on the species richness of light-demanding forest species were greater than the effect of habitat amount,whereas neither configuration metric affected the richness of shade-tolerant species.In conclusion,our findings highlight the importance of configuration in landscapes with a small amount of habitat.At the same time,they demonstrate that considering the confounding factors(e.g.species traits)is important for understanding the effects of forest configuration on biodiversity and that generalizations remain a challenge for landscape ecology.展开更多
Siliceous diatoms are one of the most prominent actors in the oceans,and they account for approximately 40%of the primary production and particulate organic carbon export flux.It is believed that changes in carbon flu...Siliceous diatoms are one of the most prominent actors in the oceans,and they account for approximately 40%of the primary production and particulate organic carbon export flux.It is believed that changes in carbon flux caused by variations in diatom distribution can lead to significant climate shifts.Although the fundamental pathways of diatom-driven carbon sequestration have long been established,there are no reports of CaCO_(3) precipitation induced by marine diatom species.This manuscript introduces novel details regarding the enhancement of aragonite precipitation during photosynthesis in Skeletonema costatum in both artificial and natural seawater.Through direct measurements of cell surfaces via a pH microelectrode and zeta potential analyzer,it was determined that the diatom-mediated promotion of CaCO_(3) precipitation is achieved through the creation of specific microenvironments with concentrated[CO_(3)^(2-)]and[Ca^(2+)]and/or the dehydrating effect of adsorbed Ca^(2+).Based on this mechanism,it is highly plausible that diatom-mediated calcification could occur in the oceans,an assertion that was supported by the significant deviation of total alkalinity(TA)from the conservative TA-salinity mixing line during a Skeletonema costatum bloom in the East China Sea and other similar occurrences.The newly discovered calcification pathway establishes a link between particulate inorganic and organic carbon flux and thus helps in the reassessment of marine carbon export fluxes and CO_(2) sequestration efficiency.This discovery may have important ramifications for assessing marine carbon cycling and predicting the potential effects of future ocean acidification.展开更多
Biological scaffolds have been the focus of bone tissue engineering research in recent years. In this paper, emodin (EM), macromolecular compound polycaprolactone (PCL), and hydroxyapatite (HA) were used as raw materi...Biological scaffolds have been the focus of bone tissue engineering research in recent years. In this paper, emodin (EM), macromolecular compound polycaprolactone (PCL), and hydroxyapatite (HA) were used as raw materials to prepare EM/PCL/HA fibers containing different EM ratios by electrospinning, and the properties and osteogenic efficacy of EM/PCL/HA were studied. Scanning electron microscopy, transmission electron microscopy, and atomic force microscopy were used to characterize the structures of HA and the electrospun fibers. Results showed that HA has high crystallinity and loose porous structure, and the electrospun fibers have a smooth and flat surface. In vitro release results showed that EM was slowly released from EM/PCL/HA within 216 h. Cell proliferation assay in mouse embryonic osteoblast precursor cells (MC3T3-E1) exhibited that 5% EM/PCL/HA had the best effect on promoting cell proliferation. Alkaline phosphatase (ALP) and mineralized nodules staining results also showed that 5% EM/PCL/HA had the best effect on promoting osteogenic differentiation. qRT-PCR results showed that the mRNA expression level of osteoblast differentiation markers, namely, bone morphogenetic protein (BMP)-2, BMP-9, and osteocalcin were significantly upregulated by 5% EM/PCL/HA treatment. These results indicate that EM/PCL/HA is a potential osteogenic material, which can provide a reference for the development of bone injury repair materials.展开更多
基金Yiwen Pan holds a research grant from the China Scholarship Council(CSC)supported by the National Natural Science Foundation of China(grant no.31860120)。
文摘The negative effects of habitat loss on biodiversity are undisputed,while the effect of habitat configuration,i.e.,the spatial arrangement of habitat area,has been debated for decades.To develop a more comprehensive understanding,it is important to know when and how configuration matters.In this study,we tested whether forest configuration influences the richness of species in groups characterized by varying shade tolerance in different ways and how such effects are related to habitat amount(i.e.,the percentage of forest cover)at the landscape scale.Based on 104 survey plots(each measuring 1km^(2))of vascular plants on the Swiss Plateau,and using two statistical approaches(i.e.,multiple regression and path analysis),we modeled the effects of habitat amount and configuration(measured as number of forest patches,total edge length,and proximity index)across all the plots and separately for three habitat amount classes:<10%,10%–30%,and>30%forest cover.When we modeled all plots together,we found that,after controlling for habitat amount,the forest configuration significantly affected species richness.When we considered the different habitat amount classes separately,most of the significant effects of habitat configuration on species richness occurred only for habitat amounts of<10%forest cover.Additionally,the response to forest configuration differed among species with different shade tolerances.When forest area was<10%,the effects of the number of patches and the total edge length on the species richness of light-demanding forest species were greater than the effect of habitat amount,whereas neither configuration metric affected the richness of shade-tolerant species.In conclusion,our findings highlight the importance of configuration in landscapes with a small amount of habitat.At the same time,they demonstrate that considering the confounding factors(e.g.species traits)is important for understanding the effects of forest configuration on biodiversity and that generalizations remain a challenge for landscape ecology.
基金supported by the National Natural Science Foundation of China(Grant Nos.42188102&42176036)the Zhejiang Provincial Natural Science Foundation of China(Grant No.LD24D060002)+1 种基金the Science and Technology Program of Zhoushan City(Grant No.2022C81002)the Fundamental Research Funds for the Central Universities,and the Ocean Negative Carbon Emission(ONCE)。
文摘Siliceous diatoms are one of the most prominent actors in the oceans,and they account for approximately 40%of the primary production and particulate organic carbon export flux.It is believed that changes in carbon flux caused by variations in diatom distribution can lead to significant climate shifts.Although the fundamental pathways of diatom-driven carbon sequestration have long been established,there are no reports of CaCO_(3) precipitation induced by marine diatom species.This manuscript introduces novel details regarding the enhancement of aragonite precipitation during photosynthesis in Skeletonema costatum in both artificial and natural seawater.Through direct measurements of cell surfaces via a pH microelectrode and zeta potential analyzer,it was determined that the diatom-mediated promotion of CaCO_(3) precipitation is achieved through the creation of specific microenvironments with concentrated[CO_(3)^(2-)]and[Ca^(2+)]and/or the dehydrating effect of adsorbed Ca^(2+).Based on this mechanism,it is highly plausible that diatom-mediated calcification could occur in the oceans,an assertion that was supported by the significant deviation of total alkalinity(TA)from the conservative TA-salinity mixing line during a Skeletonema costatum bloom in the East China Sea and other similar occurrences.The newly discovered calcification pathway establishes a link between particulate inorganic and organic carbon flux and thus helps in the reassessment of marine carbon export fluxes and CO_(2) sequestration efficiency.This discovery may have important ramifications for assessing marine carbon cycling and predicting the potential effects of future ocean acidification.
基金supported by Grants from the National Natural Science Foundation of China(No.81871756 and No.51672178)Innovation Fund of National Orthopaedic and Exercise Rehabilitation Clinical Medical Research Center(2021-NCRC-CXJJ-ZH-13).
文摘Biological scaffolds have been the focus of bone tissue engineering research in recent years. In this paper, emodin (EM), macromolecular compound polycaprolactone (PCL), and hydroxyapatite (HA) were used as raw materials to prepare EM/PCL/HA fibers containing different EM ratios by electrospinning, and the properties and osteogenic efficacy of EM/PCL/HA were studied. Scanning electron microscopy, transmission electron microscopy, and atomic force microscopy were used to characterize the structures of HA and the electrospun fibers. Results showed that HA has high crystallinity and loose porous structure, and the electrospun fibers have a smooth and flat surface. In vitro release results showed that EM was slowly released from EM/PCL/HA within 216 h. Cell proliferation assay in mouse embryonic osteoblast precursor cells (MC3T3-E1) exhibited that 5% EM/PCL/HA had the best effect on promoting cell proliferation. Alkaline phosphatase (ALP) and mineralized nodules staining results also showed that 5% EM/PCL/HA had the best effect on promoting osteogenic differentiation. qRT-PCR results showed that the mRNA expression level of osteoblast differentiation markers, namely, bone morphogenetic protein (BMP)-2, BMP-9, and osteocalcin were significantly upregulated by 5% EM/PCL/HA treatment. These results indicate that EM/PCL/HA is a potential osteogenic material, which can provide a reference for the development of bone injury repair materials.
基金supported by the National Natural Science Foundation of China(42188102,42176036,and 51120195001)the Science and Technology Program of Zhoushan City(2022C81002)the Fundamental Research Funds for the Central Universities,and the Ocean Negative Carbon Emission(ONCE)Program。
