Mercury pollution is a major environmental problem accompanying industrial activities. Most of the mercury released ends up and retained in the soil as complexes of the toxic ionic mercury (Hg2+), which then can be co...Mercury pollution is a major environmental problem accompanying industrial activities. Most of the mercury released ends up and retained in the soil as complexes of the toxic ionic mercury (Hg2+), which then can be converted by microbes into the even more toxic methylmercury which tends to bioaccumulate. Mercury detoxification of the soil can also occur by microbes converting the ionic mercury into the least toxic metallic mercury (Hg0) form, which then evaporates. The remediation potentia1 of transgenic plants carrying the MerA gene from E. coLi encoding mercuric ion reductase could be evaluated. A modified version of the gene, optimized for plant codon preferences (merApe9, Rugh et al. 1996), was introduced into tobacco by Agrobacterium-mediated leaf disk transformation. Transgenic seeds were resistant to HgCl2 at 50 μM and some of them (10-20% ) could germinate on media containing as much as 350 μM HgCl2, while the control plants were fully inhibited or died on 50 μM HgCl2. The rate of elemental mercury evolution from Hg2+ (added as HgCl2) was 5-8 times higher for transgenic plants than the control. Mercury volatilization by isolated organs standardized for fresh weight was higher (up to 5 times) in the roots than in shoots or the leaves. The data suggest that it is the root system of the transgenic plants that volatilizes most of the reduced mercury (Hg0). It also suggests that much of the mercury need not enter the vascular system to be transported to the leaves for volatilization. Thansgenic plants with the merApe9 gene may be used to mercury detoxification for environmental improvement in mercury-- contaminated regions more efficiently than it had been predicted based on data on volatilization of whole plants via the upper parts only (Rugh et al. 1996).展开更多
In this article,two new algorithms are presented that convert a given data tensor train into either a Tucker decomposition with orthogonal matrix factors or a multi-scale entanglement renormalization ansatz(MERA).The ...In this article,two new algorithms are presented that convert a given data tensor train into either a Tucker decomposition with orthogonal matrix factors or a multi-scale entanglement renormalization ansatz(MERA).The Tucker core tensor is never explicitly computed but stored as a tensor train instead,resulting in both computationally and storage efficient algorithms.Both the multilinear Tucker-ranks as well as the MERA-ranks are automatically determined by the algorithm for a given upper bound on the relative approximation error.In addition,an iterative algorithm with low computational complexity based on solving an orthogonal Procrustes problem is proposed for the first time to retrieve optimal rank-lowering disentangler tensors,which are a crucial component in the construction of a low-rank MERA.Numerical experiments demonstrate the effectiveness of the proposed algorithms together with the potential storage benefit of a low-rank MERA over a tensor train.展开更多
Present study deals with the effects of glyphosate-based herbicide,Excel Mera 71 on Anabas testudineus,Heteropnestes fossilis and Oreochromis niloticus in field conditions(1.85 kg/ha)based on anti-oxidative,metabolic ...Present study deals with the effects of glyphosate-based herbicide,Excel Mera 71 on Anabas testudineus,Heteropnestes fossilis and Oreochromis niloticus in field conditions(1.85 kg/ha)based on anti-oxidative,metabolic and digestive responses.For this study following biomarkers viz.,acetylcholinesterase(AChE),lipid peroxidation(LPO),catalase(CAT),glutathione-S-transferase(GST),alkaline phosphatase(ALP),aspartate aminotransferase(AST),alanine aminotransferase(ALT),amylase,lipase and protease were investigated in gill,stomach,intestine,liver,kidney,brain,muscle and spinal cord of the concerned fish species.Enzyme activities were significantly altered by glyphosate exposure after 30 days,these activities were tissue as well as species specific.The results suggested that these biomarkers could be used to assess the ecological risks of glyphosate on fish.Bioaccumulation factor(BAF)studied in different aquatic natural macrophytes showed order of Alternanthera philoxeroides>Azolla pinnata>Lemna sp.(Minor)>Lemna sp.(Major)>Pistia stratiotes,while transfer factor(TF)showed the order of Pistia stratiotes>Alternanthera philoxeroides>Lemna sp.Bioconcentration factor(BCF)study showed maximum accumulation of glyphosate in liver,kidney or intestine,and minimum either in bone or stomach irrespective of fish species.An integrated biomarker response(IBR),which uses a battery of biomarkers to calculate the standardized scores for each biomarker responses ranging from physiological to biochemical/molecular responses,was evaluated by combining the multiple biomarkers into a single value to evaluate quantitatively the toxicological effects of glyphosate.In general,the multiple indices exhibited variations and A.testudineus was more affected than other fish species;maximum IBR value was observed for LPO and minimum in case of ALT.The order of integrated biomarkers caused by glyphosate treatment was recorded as follows:LPO>Amylase>CAT>AST>Protease>Lipase>ALP>GST>AChE>ALT for A.testudineus,LPO>AChE>AST>Protease>CAT>Amylase>Lipase>GST>ALP>ALT for H.fossilis and AChE>CAT>LPO>AST>Amylase>GST>Protease>ALP>Lipase>ALT for O.niloticus.Finally,IBR analysis is able to distinguish the variations between different parameters and might be a useful tool for the quantification of integrated responses induced by glyphosate toward fish.展开更多
文章概述了日本"人与环境系研究"的诞生与发展,并介绍了近年来的一些课题。人与环境系研究是一个多学科交叉的领域,人间·环境学会(Man-environment Research Association,简称MERA)一直担负着日本人与环境系的研究与发展...文章概述了日本"人与环境系研究"的诞生与发展,并介绍了近年来的一些课题。人与环境系研究是一个多学科交叉的领域,人间·环境学会(Man-environment Research Association,简称MERA)一直担负着日本人与环境系的研究与发展。MERA之所以具有先进性和独特性,是源于环境心理学研究者和建筑计划学研究者各自作用及相互合作。此外,MERA成立至今,通过EDRA、IAPS、EBRA等国际会议,研究者之间的学术交流也发挥了重要的作用。日本的研究与当今日本城市面临的问题密切相关,文章通过研究案例进行了介绍。展开更多
文摘Mercury pollution is a major environmental problem accompanying industrial activities. Most of the mercury released ends up and retained in the soil as complexes of the toxic ionic mercury (Hg2+), which then can be converted by microbes into the even more toxic methylmercury which tends to bioaccumulate. Mercury detoxification of the soil can also occur by microbes converting the ionic mercury into the least toxic metallic mercury (Hg0) form, which then evaporates. The remediation potentia1 of transgenic plants carrying the MerA gene from E. coLi encoding mercuric ion reductase could be evaluated. A modified version of the gene, optimized for plant codon preferences (merApe9, Rugh et al. 1996), was introduced into tobacco by Agrobacterium-mediated leaf disk transformation. Transgenic seeds were resistant to HgCl2 at 50 μM and some of them (10-20% ) could germinate on media containing as much as 350 μM HgCl2, while the control plants were fully inhibited or died on 50 μM HgCl2. The rate of elemental mercury evolution from Hg2+ (added as HgCl2) was 5-8 times higher for transgenic plants than the control. Mercury volatilization by isolated organs standardized for fresh weight was higher (up to 5 times) in the roots than in shoots or the leaves. The data suggest that it is the root system of the transgenic plants that volatilizes most of the reduced mercury (Hg0). It also suggests that much of the mercury need not enter the vascular system to be transported to the leaves for volatilization. Thansgenic plants with the merApe9 gene may be used to mercury detoxification for environmental improvement in mercury-- contaminated regions more efficiently than it had been predicted based on data on volatilization of whole plants via the upper parts only (Rugh et al. 1996).
基金the Ministry of Education and Science of the Russian Federation(grant 14.756.31.0001).
文摘In this article,two new algorithms are presented that convert a given data tensor train into either a Tucker decomposition with orthogonal matrix factors or a multi-scale entanglement renormalization ansatz(MERA).The Tucker core tensor is never explicitly computed but stored as a tensor train instead,resulting in both computationally and storage efficient algorithms.Both the multilinear Tucker-ranks as well as the MERA-ranks are automatically determined by the algorithm for a given upper bound on the relative approximation error.In addition,an iterative algorithm with low computational complexity based on solving an orthogonal Procrustes problem is proposed for the first time to retrieve optimal rank-lowering disentangler tensors,which are a crucial component in the construction of a low-rank MERA.Numerical experiments demonstrate the effectiveness of the proposed algorithms together with the potential storage benefit of a low-rank MERA over a tensor train.
基金The authors like to thank the Head,Department of Environmental Science,The University of Burdwan,Burdwan,West Bengal,India for providing the laboratory facilities and library facilities during the course of research.We also like to thank the INSPIRE Program Division,Department of Science&Technology,Govt.of India(DST/INSPIRE Fellowship/2011/164,Dt.29.09.2011)for the financial assistance.We are also thankful to the respective reviewers for improving our manuscript.
文摘Present study deals with the effects of glyphosate-based herbicide,Excel Mera 71 on Anabas testudineus,Heteropnestes fossilis and Oreochromis niloticus in field conditions(1.85 kg/ha)based on anti-oxidative,metabolic and digestive responses.For this study following biomarkers viz.,acetylcholinesterase(AChE),lipid peroxidation(LPO),catalase(CAT),glutathione-S-transferase(GST),alkaline phosphatase(ALP),aspartate aminotransferase(AST),alanine aminotransferase(ALT),amylase,lipase and protease were investigated in gill,stomach,intestine,liver,kidney,brain,muscle and spinal cord of the concerned fish species.Enzyme activities were significantly altered by glyphosate exposure after 30 days,these activities were tissue as well as species specific.The results suggested that these biomarkers could be used to assess the ecological risks of glyphosate on fish.Bioaccumulation factor(BAF)studied in different aquatic natural macrophytes showed order of Alternanthera philoxeroides>Azolla pinnata>Lemna sp.(Minor)>Lemna sp.(Major)>Pistia stratiotes,while transfer factor(TF)showed the order of Pistia stratiotes>Alternanthera philoxeroides>Lemna sp.Bioconcentration factor(BCF)study showed maximum accumulation of glyphosate in liver,kidney or intestine,and minimum either in bone or stomach irrespective of fish species.An integrated biomarker response(IBR),which uses a battery of biomarkers to calculate the standardized scores for each biomarker responses ranging from physiological to biochemical/molecular responses,was evaluated by combining the multiple biomarkers into a single value to evaluate quantitatively the toxicological effects of glyphosate.In general,the multiple indices exhibited variations and A.testudineus was more affected than other fish species;maximum IBR value was observed for LPO and minimum in case of ALT.The order of integrated biomarkers caused by glyphosate treatment was recorded as follows:LPO>Amylase>CAT>AST>Protease>Lipase>ALP>GST>AChE>ALT for A.testudineus,LPO>AChE>AST>Protease>CAT>Amylase>Lipase>GST>ALP>ALT for H.fossilis and AChE>CAT>LPO>AST>Amylase>GST>Protease>ALP>Lipase>ALT for O.niloticus.Finally,IBR analysis is able to distinguish the variations between different parameters and might be a useful tool for the quantification of integrated responses induced by glyphosate toward fish.
文摘文章概述了日本"人与环境系研究"的诞生与发展,并介绍了近年来的一些课题。人与环境系研究是一个多学科交叉的领域,人间·环境学会(Man-environment Research Association,简称MERA)一直担负着日本人与环境系的研究与发展。MERA之所以具有先进性和独特性,是源于环境心理学研究者和建筑计划学研究者各自作用及相互合作。此外,MERA成立至今,通过EDRA、IAPS、EBRA等国际会议,研究者之间的学术交流也发挥了重要的作用。日本的研究与当今日本城市面临的问题密切相关,文章通过研究案例进行了介绍。
