Unanticipated sabotage of two underwater pipelines in the Baltic Sea(Nord Stream 1 and 2)happened on 26September 2022.Massive quantities of natural gas,primarily methane,were released into the atmosphere,which lasted ...Unanticipated sabotage of two underwater pipelines in the Baltic Sea(Nord Stream 1 and 2)happened on 26September 2022.Massive quantities of natural gas,primarily methane,were released into the atmosphere,which lasted for about one week.As a more powerful greenhouse gas than CO_(2),the potential climatic impact of methane is a global concern.Using multiple methods and datasets,a recent study reported a relatively accurate magnitude of the leaked methane at 0.22±0.03 million tons(Mt),which was lower than the initial estimate in the immediate aftermath of the event.Under an energy conservation framework used in IPCC AR6,we derived a negligible increase in global surface air temperature of 1.8×10^(-5)℃ in a 20-year time horizon caused by the methane leaks with an upper limit of 0.25 Mt.Although the resultant warming from this methane leak incident was minor,future carbon release from additional Earth system feedbacks,such as thawing permafrost,and its impact on the methane mitigation pathways of the Paris Agreement,warrants investigation.展开更多
The roads in correlation with the traffic linked to their existences are at the origin of the emission of numerous polluting substances likely to induce disturbances of the growth and the behavioral changes in the org...The roads in correlation with the traffic linked to their existences are at the origin of the emission of numerous polluting substances likely to induce disturbances of the growth and the behavioral changes in the organisms living in their vicinities. The purpose of this study is to analyze the growth and capacity accumulation of a common earthworm species (Millsonia omodeoi) in Cu, Cr, Ni, Pb and Zn in soils along a main road called “Autoroute du Nord” in C?te d’Ivoire. Thus, the earthworms were harvested in soils from a distance of 0 m (just after the sidewalk) to a distance of 200 m from the toll highway and in a control soil sampled in Lamto reserve (C?te d’Ivoire). The study was carried out in the soil laboratory at the ecological station of Lamto reserve. The Ford-Walford technique was used to determine the model and parameters most appropriated for describing the growth of earthworms. A pairwise comparison of the growth parameters was carried out using the Kruskal-Wallis test with the STATISTICA 7.1 software. The heavy metals contained in the cultivated soils and earthworms were detected and quantified using a Scanning Electron Micro-scope (MEB FEG Supra 40 VP Zeiss) and an Atomic Absorption Spectrometer SPECTRA 110 (VARIAN). The capacity accumulation of heavy metals in earthworm was determined by the bioaccumulation factor (BAF) calculation. The results of this study showed that Gompertz is the most appropriated model to describe the growth of M. omodeoi. The life cycle of M. omodeoi shows that this earthworm adopts a K type demographic strategy. Cu is the most accumulated heavy metals in M. omodeoi, when Cr is the least accumulated. Concerning heavy metal content in the earthworms, it decreases while moving away from the pavement. These results highlight a possibility of choice of M. omodeoi as 1) indicators of heavy metals pollution and 2) target of biological organisms for environmental impact studies.展开更多
Surface watercourses are areas of very high ecological and heritage value. Macroinvertebrates are bioindicators of the health of aquatic ecosystems. The aim of this study was to assess the effects of dewatering and re...Surface watercourses are areas of very high ecological and heritage value. Macroinvertebrates are bioindicators of the health of aquatic ecosystems. The aim of this study was to assess the effects of dewatering and re-watering cycles on benthic macroinvertebrate (BMI) communities. Two data collections were carried out at two stations (Okpara 1 and Okpara 2) on the Okpara river before and after dewatering. Thus, 8 samples of benthic macroinvertebrates and 12 physico-chemical parameters (T°C, pH, Transparency, Depth, Conductivity, Dissolved Oxygen that were measured in situ, and BOD5, COD, NH<sub>4</sub><sup>+</sup>, NO<sub>3</sub><sup>-</sup>, NO<sub>2</sub><sup>-</sup> and PO<sub>4</sub><sup>3-</sup>) were assayed in the laboratory. Canonical Correspondence Analysis (CCA) was used to match physico-chemical data to MIB families. Shannon and Piélou diversity indices were used to determine the effects of dewatering on MIBs. The increase in temperature values of pH, BOD5, COD, NH4</sub>+</sup>, NO3</sub>-</sup>, NO2</sub>-</sup> and PO4</sub>3-</sup>, after re-watering indicates the effect of dewatering on the quality of Okpara aquatic ecosystems. The benthic macrofauna collected consisted of 62.42% insects, 0.65% crustaceans, 6.48% molluscs, 0.72% worms and 0.14% arachnids. Whereas after re-watering, 21.67% insects, 0% crustaceans, 0.22% molluscs, 7.56% worms and 0.29% arachnids were recorded. Insects, crustaceans and molluscs were more abundant before dewatering than after. This was revealed by low abundances and taxonomic richness, as well as low Shannon index values of samples collected after re-watering.展开更多
The full-length Mlo gene was obtained by reverse transcription polymerase chain reaction （RT-PCR） and RACE. The result of sequence analysis indicated that M/o gene from Pericallis hybrida B. Nord. contained about 12...The full-length Mlo gene was obtained by reverse transcription polymerase chain reaction （RT-PCR） and RACE. The result of sequence analysis indicated that M/o gene from Pericallis hybrida B. Nord. contained about 1296bp open reading frame and encoded 431 amino acids. According to the comparison of the exogenous gene sequences by BLAST analysis and phylogenetic analysis, Mlo gene shared over 85% nucleotide homology and 98% amino acid homology. Finally, through semi-quantitative-PCR and fluorescence quantitative analysis, we found that Mlo gene showed the highest expression levels in leaves and the lowest in roots after inoculated with powdery mildew pathogen for different days.展开更多
The modeling of volatility and correlation is important in order to calculate hedge ratios, value at risk estimates, CAPM （Capital Asset Pricing Model betas）, derivate pricing and risk management in general. Recent ...The modeling of volatility and correlation is important in order to calculate hedge ratios, value at risk estimates, CAPM （Capital Asset Pricing Model betas）, derivate pricing and risk management in general. Recent access to intra-daily high-frequency data for two of the most liquid contracts at the Nord Pool exchange has made it possible to apply new and promising methods for analyzing volatility and correlation. The concepts of realized volatility and realized correlation are applied, and this study statistically describes the distribution （both distributional properties and temporal dependencies） of electricity forward data from 2005 to 2009. The main findings show that the logarithmic realized volatility is approximately normally distributed, while realized correlation seems not to be. Further, realized volatility and realized correlation have a long-memory feature. There also seems to be a high correlation between realized correlation and volatilities and positive relations between trading volume and realized volatility and between trading volume and realized correlation. These results are to a large extent consistent with earlier studies of stylized facts of other financial and commodity markets.展开更多
基金supported by the National Key Research and Development Program(Grant No.2017YFA0603503)the National Natural Science Foundation of China(Grant No.41605057)。
文摘Unanticipated sabotage of two underwater pipelines in the Baltic Sea(Nord Stream 1 and 2)happened on 26September 2022.Massive quantities of natural gas,primarily methane,were released into the atmosphere,which lasted for about one week.As a more powerful greenhouse gas than CO_(2),the potential climatic impact of methane is a global concern.Using multiple methods and datasets,a recent study reported a relatively accurate magnitude of the leaked methane at 0.22±0.03 million tons(Mt),which was lower than the initial estimate in the immediate aftermath of the event.Under an energy conservation framework used in IPCC AR6,we derived a negligible increase in global surface air temperature of 1.8×10^(-5)℃ in a 20-year time horizon caused by the methane leaks with an upper limit of 0.25 Mt.Although the resultant warming from this methane leak incident was minor,future carbon release from additional Earth system feedbacks,such as thawing permafrost,and its impact on the methane mitigation pathways of the Paris Agreement,warrants investigation.
文摘The roads in correlation with the traffic linked to their existences are at the origin of the emission of numerous polluting substances likely to induce disturbances of the growth and the behavioral changes in the organisms living in their vicinities. The purpose of this study is to analyze the growth and capacity accumulation of a common earthworm species (Millsonia omodeoi) in Cu, Cr, Ni, Pb and Zn in soils along a main road called “Autoroute du Nord” in C?te d’Ivoire. Thus, the earthworms were harvested in soils from a distance of 0 m (just after the sidewalk) to a distance of 200 m from the toll highway and in a control soil sampled in Lamto reserve (C?te d’Ivoire). The study was carried out in the soil laboratory at the ecological station of Lamto reserve. The Ford-Walford technique was used to determine the model and parameters most appropriated for describing the growth of earthworms. A pairwise comparison of the growth parameters was carried out using the Kruskal-Wallis test with the STATISTICA 7.1 software. The heavy metals contained in the cultivated soils and earthworms were detected and quantified using a Scanning Electron Micro-scope (MEB FEG Supra 40 VP Zeiss) and an Atomic Absorption Spectrometer SPECTRA 110 (VARIAN). The capacity accumulation of heavy metals in earthworm was determined by the bioaccumulation factor (BAF) calculation. The results of this study showed that Gompertz is the most appropriated model to describe the growth of M. omodeoi. The life cycle of M. omodeoi shows that this earthworm adopts a K type demographic strategy. Cu is the most accumulated heavy metals in M. omodeoi, when Cr is the least accumulated. Concerning heavy metal content in the earthworms, it decreases while moving away from the pavement. These results highlight a possibility of choice of M. omodeoi as 1) indicators of heavy metals pollution and 2) target of biological organisms for environmental impact studies.
文摘Surface watercourses are areas of very high ecological and heritage value. Macroinvertebrates are bioindicators of the health of aquatic ecosystems. The aim of this study was to assess the effects of dewatering and re-watering cycles on benthic macroinvertebrate (BMI) communities. Two data collections were carried out at two stations (Okpara 1 and Okpara 2) on the Okpara river before and after dewatering. Thus, 8 samples of benthic macroinvertebrates and 12 physico-chemical parameters (T°C, pH, Transparency, Depth, Conductivity, Dissolved Oxygen that were measured in situ, and BOD5, COD, NH<sub>4</sub><sup>+</sup>, NO<sub>3</sub><sup>-</sup>, NO<sub>2</sub><sup>-</sup> and PO<sub>4</sub><sup>3-</sup>) were assayed in the laboratory. Canonical Correspondence Analysis (CCA) was used to match physico-chemical data to MIB families. Shannon and Piélou diversity indices were used to determine the effects of dewatering on MIBs. The increase in temperature values of pH, BOD5, COD, NH4</sub>+</sup>, NO3</sub>-</sup>, NO2</sub>-</sup> and PO4</sub>3-</sup>, after re-watering indicates the effect of dewatering on the quality of Okpara aquatic ecosystems. The benthic macrofauna collected consisted of 62.42% insects, 0.65% crustaceans, 6.48% molluscs, 0.72% worms and 0.14% arachnids. Whereas after re-watering, 21.67% insects, 0% crustaceans, 0.22% molluscs, 7.56% worms and 0.29% arachnids were recorded. Insects, crustaceans and molluscs were more abundant before dewatering than after. This was revealed by low abundances and taxonomic richness, as well as low Shannon index values of samples collected after re-watering.
基金Supported by Postdoctoral Scientifi c Research Foundation of Heilongjiang Province(LBH-Q10144)the Natural Science Foundation of Heilongjiang Province(C201112)Northeast Agricultural University Doctoral Research Fund(200830)
文摘The full-length Mlo gene was obtained by reverse transcription polymerase chain reaction （RT-PCR） and RACE. The result of sequence analysis indicated that M/o gene from Pericallis hybrida B. Nord. contained about 1296bp open reading frame and encoded 431 amino acids. According to the comparison of the exogenous gene sequences by BLAST analysis and phylogenetic analysis, Mlo gene shared over 85% nucleotide homology and 98% amino acid homology. Finally, through semi-quantitative-PCR and fluorescence quantitative analysis, we found that Mlo gene showed the highest expression levels in leaves and the lowest in roots after inoculated with powdery mildew pathogen for different days.
文摘The modeling of volatility and correlation is important in order to calculate hedge ratios, value at risk estimates, CAPM （Capital Asset Pricing Model betas）, derivate pricing and risk management in general. Recent access to intra-daily high-frequency data for two of the most liquid contracts at the Nord Pool exchange has made it possible to apply new and promising methods for analyzing volatility and correlation. The concepts of realized volatility and realized correlation are applied, and this study statistically describes the distribution （both distributional properties and temporal dependencies） of electricity forward data from 2005 to 2009. The main findings show that the logarithmic realized volatility is approximately normally distributed, while realized correlation seems not to be. Further, realized volatility and realized correlation have a long-memory feature. There also seems to be a high correlation between realized correlation and volatilities and positive relations between trading volume and realized volatility and between trading volume and realized correlation. These results are to a large extent consistent with earlier studies of stylized facts of other financial and commodity markets.
