In this study,the distribution pattern of meiofauna from nine sandy beaches at six latitudinal gradients along Chinese coast between 18 and 40?N was studied on their meiofauna abundance to examine the effect of latitu...In this study,the distribution pattern of meiofauna from nine sandy beaches at six latitudinal gradients along Chinese coast between 18 and 40?N was studied on their meiofauna abundance to examine the effect of latitudinal gradients.In general,meiofauna abundance was lower in four subtropical beaches in Xiamen(24?N) and Zhoushan(29?N) than that in other beaches.Meiofauna abundance differed little between tropical and temperate beaches.The taxonomic structure of meiofauna showed a dominance of nematode in colder area.The relative composition of turbellarians and polychaetes increased in warmer area.In addition to latitudinal gradient,salinity,oxygenation,sediment grain size affect also the meiofauna latitudinal distribution.As for horizontal distribution,the highest meiofauna abundance was found in low tidal zone at tropical beaches,and in middle tidal zone at temperate beaches.The horizontal distribution of meiofauna was controlled by both physical and biotic factors including feeding and anthropogenic activities.Although meiofauna abundance exhibited a horizontal difference,the composition of meiofaunal main taxa was unanimous horizontally at all beaches at the same sampling latitude.展开更多
In spring and summer 2011, the macro- and megabenthic fauna in two sections of the East China Sea were investigated using an Agassiz net trawl to detect the seasonal and spatial variations of benthic community charact...In spring and summer 2011, the macro- and megabenthic fauna in two sections of the East China Sea were investigated using an Agassiz net trawl to detect the seasonal and spatial variations of benthic community characteristics and the relation to environmental variables. The total number of species increased slightly from spring (131 species) to summer (133) whereas the percentage of Mollusca decreased significantly. The index of relative importance (IRI) indicated that the top five important species changed completely from spring to summer. Species number, abundance and biomass in summer were significantly higher than in spring, but no significant difference was observed among areas (coastal, transitional and oceanic areas, divided basically from inshore to offshore). Species richness (at), diversity (H) and evenness (J) showed no significant seasonal or spatial variations. Cluster analysis and nMDS ordination identified three benthic communities from inshore to offshore, corresponding to the three areas. Analysis of Similarity (ANOSIM) indicated the overall significant difference in community structure between seasons and among areas. K-dominance curves revealed the high intrinsic diversity in the offshore area. Canonical correspondence analysis showed that the coastal community was positively correlated to total nitrogen and total organic carbon in spring, but negatively in summer; oceanic community was positively correlated to total nitrogen and total organic carbon in both seasons. Species such as Coelorhynchus multispinulosus, Neobythites sivicola, Lepidotrigla alata, Solenocera melantho, Parapenaeus fissuroides, Oratosquilla gonypetes and Spiropagurus spiriger occurred exclusively in the offshore oceanic area and their presence may reflect the influence of the offshore Kuroshio Current.展开更多
A pool of dormant stages of planktonic organisms in saline lakes is a substantial component in the plankton communities;we need to take it into account to understand plankton dynamics.Hypersaline water bodies in Crime...A pool of dormant stages of planktonic organisms in saline lakes is a substantial component in the plankton communities;we need to take it into account to understand plankton dynamics.Hypersaline water bodies in Crimea,the largest peninsula in the Black Sea,constitute a very characteristic and peculiar habitat type in the region.We examined the presence of crustacean resting stages in sediments of dried up sites of the Crimean hypersaline lakes.Sediment samples were taken in 9 different lakes.Experiments performed on the hatching of these resting stages showed the presence of Moina salina(Cladocera),parthenogenetic Artemia and Artemia urmiana(Anostraca),Eucypris mareotica( inflata)(Ostracoda),and Cletocamptus retrogressus(Harpacticoida).Comparing the experimental results obtained with clean dried brine shrimp cysts and those kept in sediment samples,it was noted that clean cysts hatched much faster than those from sediments did.Some components in bottom sediments slow down and desynchronize hatching from resting eggs in different groups of crustaceans.The sediments of different lakes inhibited the nauplii output from Artemia and ostracod resting eggs to different degrees.More data are needed before we can discuss the reasons of this inhibition.The nonsynchronous output of active stages from the bottom resting ones may be an adaptation that allows crustacean species to exist in extreme and unpredictably changing environments,avoiding the risk that all may emerge at once under unsuitable conditions.展开更多
Microbial fuel cells (MFCs) rely on microbial conversion of organic substrates to electricity. The optimal perfor- mance depends on the establishment of a microbial community rich in electrogenic bacteria. Usually t...Microbial fuel cells (MFCs) rely on microbial conversion of organic substrates to electricity. The optimal perfor- mance depends on the establishment of a microbial community rich in electrogenic bacteria. Usually this micro- bial community is established from inoculation of the MFC anode chamber with naturally occurring mixed inocula. In this study, the electrochemical performance of MFCs and microbial community evolution were eval- uated for three inocula including domestic wastewater (DW), lake sediment (LS) and biogas sludge (BS) with varying substrate loading (Lsub) and external resistance (Rext) on the MFC. The electrogenic bacterium Geobacter sulfurreducens was identified in all inocula and its abundance during MFC operation was positively linked to the MFC performance. The IS inoculated MFCs showed highest abundance (18% ± 1%) of G. sulfurreducens, maximum current density [Imax = (690 ± 30) mA.m 2] and coulombic efficiency (CE = 29% ±1%) with acetate as the substrate./max and CE increased to (1780 ± 30) mA.m-2 and 58%± 1%, respectively, after decreasing the Rext from 1000 Ωto 200 Ω, which also correlated to a higher abundance ofG. sulfurreducens (21% ±0.7%) on the MFC anodic biofilm. The data obtained contribute to understanding the microbial community response to Lsub and Roy, for of timizing electricity eneration in MFCs.展开更多
The effectiveness of adsorptive treatment of waste cooking oils was assessed in terms of suitability for biodiesel production. New technologies involving standard diesel engines have been developed using biofuel produ...The effectiveness of adsorptive treatment of waste cooking oils was assessed in terms of suitability for biodiesel production. New technologies involving standard diesel engines have been developed using biofuel products from vegetable oils and waste animal fats based on environmental and economic considerations. The potential application of used rapeseed oil after treatment with a mixture of active carbon (AR) and magnesium silicate (MG) as energy source was studied. The results were compared with substrates standard in the Vogel&Noot GmbH technology for the transesterification of oils and fats.展开更多
We made comparative studies of three tropical ox-bow lakes in India with different trophic states.The species number of zooplanktons was negatively correlated with the degree of water eutrophication,and lakes of simil...We made comparative studies of three tropical ox-bow lakes in India with different trophic states.The species number of zooplanktons was negatively correlated with the degree of water eutrophication,and lakes of similar trophic status had higher similarity of species.The most significant differences of species composition were observed with rotifers and zoobenthos.The density and biomass of phytoplankton,rotifers,oligochaetes and chironomids tended to increase with increasing nutrients.We observed a significant difference of dominant species in different waters,especially the eutrophic lake,which was dominated by a few species of oligochaetes.The abundance of Tanypus bilobatus showed a highly significant correlation with the degree of eutrophication.Rotifers and zoobenthos showed considerably lower biodiversity in the eutrophic lake.展开更多
The Inohana Lake is a branch lake of the Hamana Lake. The Inohana Lake is an estuary rather than a brackish lake, and has suffered environmental problems such as eutrophication and bottom hypoxic water. In this study,...The Inohana Lake is a branch lake of the Hamana Lake. The Inohana Lake is an estuary rather than a brackish lake, and has suffered environmental problems such as eutrophication and bottom hypoxic water. In this study, the coupled hydrodynamic and ecological models (eco-hydrodynamic model) were used to construct the strategy for preventing the bottom hypoxic water and improving or recovering the water quality in the lake. Using the model input obtained from the summertime data over 1998-2002, the summer-average flow field and oxygen concentration and budget of the standard run were calculated. Remedial measures used in this study are divided into two parts: the biogeochemical and physical changes in the present situation. For the remedial measures including the biogeochemical changes in the present situation, the simulations considering the reductions of the nutrient inputs from the river, main lake (land) and bottom sediment, and the sediment oxygen demand (SOD) were carried out. For the remedial measures including the physical changes, the 50 and 100 m extensions of the inlet width were considered in the model runs. These simulated results were compared in terms of changes in the dissolved oxygen (DO) concentration and oxygen budget in the bottom layer in the Inohana Lake. There was no significant change in the DO concentration and oxygen stock in the simulations for the reduction of the nutrient inputs from the land and bottom sediment, however increases in those in the simulations for the reduction of SOD. When SOD was reduced by 50%, the bottom DO concentration increased by approximately 2 mg/L and the oxygen stock in the bottom layer increased by 47% comparing the present situation (the standard run) of the lake. The simulation results for inlet width extension showed that the extension of width makes the DO concentration and oxygen stock lower. The remedial measures for the sediment control were proposed to prevent the bottom hypoxia and manage the water quality.展开更多
The whole metazoan community inhabiting Laizhou Bay and adjacent Bohai Sea waters were sampled in late autumn, 2006. Secondary production estimates for macrofauna and meiofauna were made separately. Total benthic seco...The whole metazoan community inhabiting Laizhou Bay and adjacent Bohai Sea waters were sampled in late autumn, 2006. Secondary production estimates for macrofauna and meiofauna were made separately. Total benthic secondary production was as high as 8.38 ±4.08 g ash-free dry weight (AFDW) m^-2 a^-1, which represented the autumn production level. In general, macrofaunal secondary production in Laizhou Bay was much lower than that in adjacent Bohai Sea areas. In contrast, meiofaunal secondary production in Laizhou Bay was higher than that in adjacent Bohai Sea areas. Macrofatma contributed 61% to benthic secondary production (5.09 ±3.26 g AFDW m^-2 a^-1), lower than the value in previous studies in Bohai Sea. Sediment granulometric characteristics and bottom-water salinity could explain the substantial variability in the macrofauna biomass and production. Meiofaunal production was an important component of benthic production and exceeded macrofauna production under exceptional conditions, e.g. in Laizhou Bay, where macrofauna was restricted. Chlorophyll pigments (Chl-a) concentrations in sediment explained the general meiofaunal biomass and production distribution here.展开更多
The increase in anthropogenic activities occur along the upstream of Citarum River Basin (CRB) in Bandung regency had a negative impact to the water quality caused by the presence of human activity, it will be able ...The increase in anthropogenic activities occur along the upstream of Citarum River Basin (CRB) in Bandung regency had a negative impact to the water quality caused by the presence of human activity, it will be able to be a disruption to the ecosystem aquatic. The purpose of this study was to determine the relationship of the physical and chemical parameters of water and sediment to the presence of macrozoobenthos populations. Based on the result of Pearson Correlation Analysis (PCA), the parameters of COD, TOC and silt composition were the highest correlation to the macrozoobenthos population density, the value were 0.966, 0.865 and 0.576. Although PCA analysis is used to determine the relationship between the parameters of water, sediment and sediment particle distribution, the result showed that the water parameters were the mayor component affected the density of macrozoobenthos. While based on the composition of sediment, it is found that substrate as silt, clay and gravel and phosphate parameter affected the density of macrozoobenthos. The measurement of water quality also were calculated by Biotic Monitoring Working Party-Average Score Per Taxon (BMWP-ASPT) index showed that the quality were polluted condition, although by Pollution Index (IP) method showed as a light polluted category.展开更多
OBJECTIVE: To investigate the biomechanical characters of human dura and its substitutes and to establish guidelines for selection of optimal repair materials for reconstruction of skull base defects. METHODS: A measu...OBJECTIVE: To investigate the biomechanical characters of human dura and its substitutes and to establish guidelines for selection of optimal repair materials for reconstruction of skull base defects. METHODS: A measurement of creep properties of human dura and its substitutes were conducted using biomechanical tests. The dynamic changes of biomechanical properties of canine dura obtained from skull base defects were observed as well. RESULTS: The creep properties of human dura presented a linear-relationship between initial strain and stress, and the creep strain increased slowly with time. The creep compliance formula for human dura and its substitutes was as follows: J (t) = J(0) + Kf (t). The initial compliance of canine dura in skull base defects was reduced by 35%, 46% and 50%, respectively 1, 3 and 6 months after surgery. CONCLUSION: The optimal material for the repair of skull base defects can be estimated using creep compliance analysis. The less the compliance, the better the property of anti-protrusion. Fresh human dura is the least compliant and then in increasing order are lyophilized human dura, fresh human pericranium, Terylene and silicon membranes. The pattern of biomechanical characteristics of the dura mater at skull base defects shows that the strain ability of the dura mater decreases distinctly for 1 - 3 months and then remains almost unchanged for 3 - 6 months after surgery.展开更多
Most previous researches have focused on biochar application in agricultural soils; however, limited information is available concerning the effects of biochar amendment on greenhouse substrate properties. A greenhous...Most previous researches have focused on biochar application in agricultural soils; however, limited information is available concerning the effects of biochar amendment on greenhouse substrate properties. A greenhouse experiment was conducted to investigate effects of wheat straw biochar (0-160 mL L-1) and super absorbent polymer (SAP, 0.8 g L-1) on physical and chemical properties of a substrate based on spent pig litter compost and the growth of water spinach (Ipomoea aquatica Forsk). Total porosity, water-holding capacity~ pH and electrical conductivity (EC) of the substrate significantly increased with increasing biochar rates, especially in the substrate without SAP. The values of pH and EC were significantly lower in the substrate with SAP than those without SAP at the high biochar application rates (100-160 mL L-l). The germination rates of water spinach decreased with increasing biochar rates when biochar was added alone (76.9%-83.7%), whereas the rates increased to 83.6%-85.8% when biochar was added in combination with SAP. Growth parameters of water spinach and nutrient uptake by shoots and roots increased with increasing biochar rates and reached the maximum values at the biochar rate of 100 mL L-1. There were significant cubic relationships between the uptake of nutrients (N, P, and K) and biochar rates, both with and without SAP addition. In order to avoid negative effects on plant growth, the biochar application rate should be controlled at an optimal level (100 mL L-1 ). The SAP addition not only enhanced the positive effects of biochar application on the properties of the substrate, but also inhibited the excessive rise of pH and EC following biochar additions, which led to better plant growth and enhanced nutrient uptakes by water spinach.展开更多
This study examines how the spatiotemporal patterns of functional groups of macro benthos responded to coastal wetland restoration projects. Compared with the traditional single-species approach, methods for identifyi...This study examines how the spatiotemporal patterns of functional groups of macro benthos responded to coastal wetland restoration projects. Compared with the traditional single-species approach, methods for identifying functional groups of macro benthos more comprehensively reflect the states of the wetland, i.e., spatiotemporal patterns and the related influencing factors. In this study, the macro benthos samples, soil samples, and plant samples were collected at each same sample site in April, July, and October of 2017 and January of 2018. After classification of the macro benthos functional groups according to some traits, the factors influencing the functional groups were examined by a linear stepwise regression. The results showed that all macro benthos were classified into 11 different functional groups based on their traits of forms of locomotion, feeding habits, and food gathering methods. The semi-mobile suspensivores(FDX), semi-mobile surface detritivores(SDX), and Jawed mobile carnivores(CMJ) were the main groups observed in a year. Regression analysis showed that particle size,moisture content, and plant height were important common factors influencing most groups. The main influencing factor of FDX was particle size(P=0.020). Moisture content(P=0.004), plant cover degree(P=0.008), and particle size(P=0.032) comprised the main restrictions of SDX in summer. Soil salinity(P=0.040) and plant height(P=0.011)were the factors influencing CMJ in autumn and winter. This study shows the changing characteristics of macro benthos functional groups to promote coastal wetland restoration and future biogeomorphological studies.展开更多
基金supported by the National Natural Science Foundation of China (Nos.40906063,40730847,41106122,and 41076090)
文摘In this study,the distribution pattern of meiofauna from nine sandy beaches at six latitudinal gradients along Chinese coast between 18 and 40?N was studied on their meiofauna abundance to examine the effect of latitudinal gradients.In general,meiofauna abundance was lower in four subtropical beaches in Xiamen(24?N) and Zhoushan(29?N) than that in other beaches.Meiofauna abundance differed little between tropical and temperate beaches.The taxonomic structure of meiofauna showed a dominance of nematode in colder area.The relative composition of turbellarians and polychaetes increased in warmer area.In addition to latitudinal gradient,salinity,oxygenation,sediment grain size affect also the meiofauna latitudinal distribution.As for horizontal distribution,the highest meiofauna abundance was found in low tidal zone at tropical beaches,and in middle tidal zone at temperate beaches.The horizontal distribution of meiofauna was controlled by both physical and biotic factors including feeding and anthropogenic activities.Although meiofauna abundance exhibited a horizontal difference,the composition of meiofaunal main taxa was unanimous horizontally at all beaches at the same sampling latitude.
基金Supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA11020303)the Ocean Public Welfare Scientifi c Research Project,State Oceanic Administration of the PRC(No.201505004)the National Natural Science Foundation of China(Nos.41176133,41406157)
文摘In spring and summer 2011, the macro- and megabenthic fauna in two sections of the East China Sea were investigated using an Agassiz net trawl to detect the seasonal and spatial variations of benthic community characteristics and the relation to environmental variables. The total number of species increased slightly from spring (131 species) to summer (133) whereas the percentage of Mollusca decreased significantly. The index of relative importance (IRI) indicated that the top five important species changed completely from spring to summer. Species number, abundance and biomass in summer were significantly higher than in spring, but no significant difference was observed among areas (coastal, transitional and oceanic areas, divided basically from inshore to offshore). Species richness (at), diversity (H) and evenness (J) showed no significant seasonal or spatial variations. Cluster analysis and nMDS ordination identified three benthic communities from inshore to offshore, corresponding to the three areas. Analysis of Similarity (ANOSIM) indicated the overall significant difference in community structure between seasons and among areas. K-dominance curves revealed the high intrinsic diversity in the offshore area. Canonical correspondence analysis showed that the coastal community was positively correlated to total nitrogen and total organic carbon in spring, but negatively in summer; oceanic community was positively correlated to total nitrogen and total organic carbon in both seasons. Species such as Coelorhynchus multispinulosus, Neobythites sivicola, Lepidotrigla alata, Solenocera melantho, Parapenaeus fissuroides, Oratosquilla gonypetes and Spiropagurus spiriger occurred exclusively in the offshore oceanic area and their presence may reflect the influence of the offshore Kuroshio Current.
文摘A pool of dormant stages of planktonic organisms in saline lakes is a substantial component in the plankton communities;we need to take it into account to understand plankton dynamics.Hypersaline water bodies in Crimea,the largest peninsula in the Black Sea,constitute a very characteristic and peculiar habitat type in the region.We examined the presence of crustacean resting stages in sediments of dried up sites of the Crimean hypersaline lakes.Sediment samples were taken in 9 different lakes.Experiments performed on the hatching of these resting stages showed the presence of Moina salina(Cladocera),parthenogenetic Artemia and Artemia urmiana(Anostraca),Eucypris mareotica( inflata)(Ostracoda),and Cletocamptus retrogressus(Harpacticoida).Comparing the experimental results obtained with clean dried brine shrimp cysts and those kept in sediment samples,it was noted that clean cysts hatched much faster than those from sediments did.Some components in bottom sediments slow down and desynchronize hatching from resting eggs in different groups of crustaceans.The sediments of different lakes inhibited the nauplii output from Artemia and ostracod resting eggs to different degrees.More data are needed before we can discuss the reasons of this inhibition.The nonsynchronous output of active stages from the bottom resting ones may be an adaptation that allows crustacean species to exist in extreme and unpredictably changing environments,avoiding the risk that all may emerge at once under unsuitable conditions.
基金grateful to Danida Fellowship Centre for supporting the research project (Biobased electricity in developing countries,DFC No.11-091 Ris?)The financial support from China Scholarship Council (CSC No.2011635051) for Guotao Sun is gratefully acknowledged.Annette E.Jensen,DTU is thanked for technical support
文摘Microbial fuel cells (MFCs) rely on microbial conversion of organic substrates to electricity. The optimal perfor- mance depends on the establishment of a microbial community rich in electrogenic bacteria. Usually this micro- bial community is established from inoculation of the MFC anode chamber with naturally occurring mixed inocula. In this study, the electrochemical performance of MFCs and microbial community evolution were eval- uated for three inocula including domestic wastewater (DW), lake sediment (LS) and biogas sludge (BS) with varying substrate loading (Lsub) and external resistance (Rext) on the MFC. The electrogenic bacterium Geobacter sulfurreducens was identified in all inocula and its abundance during MFC operation was positively linked to the MFC performance. The IS inoculated MFCs showed highest abundance (18% ± 1%) of G. sulfurreducens, maximum current density [Imax = (690 ± 30) mA.m 2] and coulombic efficiency (CE = 29% ±1%) with acetate as the substrate./max and CE increased to (1780 ± 30) mA.m-2 and 58%± 1%, respectively, after decreasing the Rext from 1000 Ωto 200 Ω, which also correlated to a higher abundance ofG. sulfurreducens (21% ±0.7%) on the MFC anodic biofilm. The data obtained contribute to understanding the microbial community response to Lsub and Roy, for of timizing electricity eneration in MFCs.
文摘The effectiveness of adsorptive treatment of waste cooking oils was assessed in terms of suitability for biodiesel production. New technologies involving standard diesel engines have been developed using biofuel products from vegetable oils and waste animal fats based on environmental and economic considerations. The potential application of used rapeseed oil after treatment with a mixture of active carbon (AR) and magnesium silicate (MG) as energy source was studied. The results were compared with substrates standard in the Vogel&Noot GmbH technology for the transesterification of oils and fats.
文摘We made comparative studies of three tropical ox-bow lakes in India with different trophic states.The species number of zooplanktons was negatively correlated with the degree of water eutrophication,and lakes of similar trophic status had higher similarity of species.The most significant differences of species composition were observed with rotifers and zoobenthos.The density and biomass of phytoplankton,rotifers,oligochaetes and chironomids tended to increase with increasing nutrients.We observed a significant difference of dominant species in different waters,especially the eutrophic lake,which was dominated by a few species of oligochaetes.The abundance of Tanypus bilobatus showed a highly significant correlation with the degree of eutrophication.Rotifers and zoobenthos showed considerably lower biodiversity in the eutrophic lake.
文摘The Inohana Lake is a branch lake of the Hamana Lake. The Inohana Lake is an estuary rather than a brackish lake, and has suffered environmental problems such as eutrophication and bottom hypoxic water. In this study, the coupled hydrodynamic and ecological models (eco-hydrodynamic model) were used to construct the strategy for preventing the bottom hypoxic water and improving or recovering the water quality in the lake. Using the model input obtained from the summertime data over 1998-2002, the summer-average flow field and oxygen concentration and budget of the standard run were calculated. Remedial measures used in this study are divided into two parts: the biogeochemical and physical changes in the present situation. For the remedial measures including the biogeochemical changes in the present situation, the simulations considering the reductions of the nutrient inputs from the river, main lake (land) and bottom sediment, and the sediment oxygen demand (SOD) were carried out. For the remedial measures including the physical changes, the 50 and 100 m extensions of the inlet width were considered in the model runs. These simulated results were compared in terms of changes in the dissolved oxygen (DO) concentration and oxygen budget in the bottom layer in the Inohana Lake. There was no significant change in the DO concentration and oxygen stock in the simulations for the reduction of the nutrient inputs from the land and bottom sediment, however increases in those in the simulations for the reduction of SOD. When SOD was reduced by 50%, the bottom DO concentration increased by approximately 2 mg/L and the oxygen stock in the bottom layer increased by 47% comparing the present situation (the standard run) of the lake. The simulation results for inlet width extension showed that the extension of width makes the DO concentration and oxygen stock lower. The remedial measures for the sediment control were proposed to prevent the bottom hypoxia and manage the water quality.
基金supported by the National Natural Science Foundation of China (Nos 40730847, 40906063)
文摘The whole metazoan community inhabiting Laizhou Bay and adjacent Bohai Sea waters were sampled in late autumn, 2006. Secondary production estimates for macrofauna and meiofauna were made separately. Total benthic secondary production was as high as 8.38 ±4.08 g ash-free dry weight (AFDW) m^-2 a^-1, which represented the autumn production level. In general, macrofaunal secondary production in Laizhou Bay was much lower than that in adjacent Bohai Sea areas. In contrast, meiofaunal secondary production in Laizhou Bay was higher than that in adjacent Bohai Sea areas. Macrofatma contributed 61% to benthic secondary production (5.09 ±3.26 g AFDW m^-2 a^-1), lower than the value in previous studies in Bohai Sea. Sediment granulometric characteristics and bottom-water salinity could explain the substantial variability in the macrofauna biomass and production. Meiofaunal production was an important component of benthic production and exceeded macrofauna production under exceptional conditions, e.g. in Laizhou Bay, where macrofauna was restricted. Chlorophyll pigments (Chl-a) concentrations in sediment explained the general meiofaunal biomass and production distribution here.
文摘The increase in anthropogenic activities occur along the upstream of Citarum River Basin (CRB) in Bandung regency had a negative impact to the water quality caused by the presence of human activity, it will be able to be a disruption to the ecosystem aquatic. The purpose of this study was to determine the relationship of the physical and chemical parameters of water and sediment to the presence of macrozoobenthos populations. Based on the result of Pearson Correlation Analysis (PCA), the parameters of COD, TOC and silt composition were the highest correlation to the macrozoobenthos population density, the value were 0.966, 0.865 and 0.576. Although PCA analysis is used to determine the relationship between the parameters of water, sediment and sediment particle distribution, the result showed that the water parameters were the mayor component affected the density of macrozoobenthos. While based on the composition of sediment, it is found that substrate as silt, clay and gravel and phosphate parameter affected the density of macrozoobenthos. The measurement of water quality also were calculated by Biotic Monitoring Working Party-Average Score Per Taxon (BMWP-ASPT) index showed that the quality were polluted condition, although by Pollution Index (IP) method showed as a light polluted category.
基金ThisstudywassupportedbyagrantfromtheNationalNaturalScienceFoundationofChina (No 3 9670 199)
文摘OBJECTIVE: To investigate the biomechanical characters of human dura and its substitutes and to establish guidelines for selection of optimal repair materials for reconstruction of skull base defects. METHODS: A measurement of creep properties of human dura and its substitutes were conducted using biomechanical tests. The dynamic changes of biomechanical properties of canine dura obtained from skull base defects were observed as well. RESULTS: The creep properties of human dura presented a linear-relationship between initial strain and stress, and the creep strain increased slowly with time. The creep compliance formula for human dura and its substitutes was as follows: J (t) = J(0) + Kf (t). The initial compliance of canine dura in skull base defects was reduced by 35%, 46% and 50%, respectively 1, 3 and 6 months after surgery. CONCLUSION: The optimal material for the repair of skull base defects can be estimated using creep compliance analysis. The less the compliance, the better the property of anti-protrusion. Fresh human dura is the least compliant and then in increasing order are lyophilized human dura, fresh human pericranium, Terylene and silicon membranes. The pattern of biomechanical characteristics of the dura mater at skull base defects shows that the strain ability of the dura mater decreases distinctly for 1 - 3 months and then remains almost unchanged for 3 - 6 months after surgery.
基金supported by the National Natural Science Foundation of China (No.41401259)the General Financial Grant from the China Postdoctoral Science Foundation (No.2014M551528)+1 种基金the Independent Innovation Project of Jiangsu Province,China (No.CX(14)2035)the Special Scientific Research Fund of Agricultural Public Welfare Profession of China (No.201203050)
文摘Most previous researches have focused on biochar application in agricultural soils; however, limited information is available concerning the effects of biochar amendment on greenhouse substrate properties. A greenhouse experiment was conducted to investigate effects of wheat straw biochar (0-160 mL L-1) and super absorbent polymer (SAP, 0.8 g L-1) on physical and chemical properties of a substrate based on spent pig litter compost and the growth of water spinach (Ipomoea aquatica Forsk). Total porosity, water-holding capacity~ pH and electrical conductivity (EC) of the substrate significantly increased with increasing biochar rates, especially in the substrate without SAP. The values of pH and EC were significantly lower in the substrate with SAP than those without SAP at the high biochar application rates (100-160 mL L-l). The germination rates of water spinach decreased with increasing biochar rates when biochar was added alone (76.9%-83.7%), whereas the rates increased to 83.6%-85.8% when biochar was added in combination with SAP. Growth parameters of water spinach and nutrient uptake by shoots and roots increased with increasing biochar rates and reached the maximum values at the biochar rate of 100 mL L-1. There were significant cubic relationships between the uptake of nutrients (N, P, and K) and biochar rates, both with and without SAP addition. In order to avoid negative effects on plant growth, the biochar application rate should be controlled at an optimal level (100 mL L-1 ). The SAP addition not only enhanced the positive effects of biochar application on the properties of the substrate, but also inhibited the excessive rise of pH and EC following biochar additions, which led to better plant growth and enhanced nutrient uptakes by water spinach.
基金The National Key Research and Development Program of China (2017YFC0506002)The Foundation of Shanghai Marine Environmental Monitoring Center (MEMRT202003)。
文摘This study examines how the spatiotemporal patterns of functional groups of macro benthos responded to coastal wetland restoration projects. Compared with the traditional single-species approach, methods for identifying functional groups of macro benthos more comprehensively reflect the states of the wetland, i.e., spatiotemporal patterns and the related influencing factors. In this study, the macro benthos samples, soil samples, and plant samples were collected at each same sample site in April, July, and October of 2017 and January of 2018. After classification of the macro benthos functional groups according to some traits, the factors influencing the functional groups were examined by a linear stepwise regression. The results showed that all macro benthos were classified into 11 different functional groups based on their traits of forms of locomotion, feeding habits, and food gathering methods. The semi-mobile suspensivores(FDX), semi-mobile surface detritivores(SDX), and Jawed mobile carnivores(CMJ) were the main groups observed in a year. Regression analysis showed that particle size,moisture content, and plant height were important common factors influencing most groups. The main influencing factor of FDX was particle size(P=0.020). Moisture content(P=0.004), plant cover degree(P=0.008), and particle size(P=0.032) comprised the main restrictions of SDX in summer. Soil salinity(P=0.040) and plant height(P=0.011)were the factors influencing CMJ in autumn and winter. This study shows the changing characteristics of macro benthos functional groups to promote coastal wetland restoration and future biogeomorphological studies.