924 resultados para Giant Rats Tail Grass Serious Environmental Weed
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Hygrophila ( Hygrophila polysperma (Roxb.) T. Anderson) is a plants which forms serious aquatic weed problems. Both submerged and emergent growth forms occur. Nutritional studies with a controlled release fertilizer and sediments collected from hygrophila-infested areas were conducted with the emergent growth habit to provide insights into growth of this introduced plant. Plant dry weights for experimental 16- week culture periods with low average temperatures were associated with low amounts of hygrophila biomass as compared to culture periods with high average temperatures. Hygrophila cultured in sand rooting media with the controlled release fertilizer produced as much as 20 times more dry weight than plants cultured in sediments only. First-degree linear regression statistics showed hygrophila dry weights were highly related to ammonia nitrogen, magnesium, sodium, and pH values in the sediments. These findings show the close relationship of the emergent growth habit of hygrophila to sediment nutrients. Analyses for certain sediment characteristics may provide an indication of the potential growth that may be expected for weed infestations of this plant. Hygrophila grows year round in south Florida; however, visual observations of canals and other bodies of water indicate that lower amounts of hygrophila plants occur during the cooler months of year than during the summer season. These findings show the seasonal growth of emergent hygrophila occurs with biomass dependent on both sediment nutrients and temperature.
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A prática da troca de óleo lubrificante usado, particularmente óleos automotivos, representa um grave problema ambiental em função de sua natureza perigosa, do manuseio incorreto e do descarte indiscriminado no meio ambiente. A investigação quanto à remediação de áreas contaminadas por esse resíduo torna-se necessária, particularmente para solo de natureza argilosa. O presente estudo teve por objetivo avaliar a biorremediação de um solo argiloso contaminado por óleo lubrificante utilizando biorreatores de fase semi-sólida. Frascos tipo Erlenmeyer, contendo 20 g de solo contaminado com 3% (m/m) de óleo lubrificante, em triplicata, foram mantidos em temperatura e agitação constantes, segundo as seguintes estratégias de tratamento: (i) Bioestímulo com ajuste de nutrientes (BIOE); (ii) Bioaumento com adição de inóculo microbiano aclimatado (BIOA); (iii) Bioestímulo e adição de surfactante sintético Tween-80 (BIOES); (iv) Bioaumento, bioestímulo e surfactante sintético Tween-80 (BIOAS) e (iv) controle, com água destilada purificada (CONT). A eficiência de remoção do contaminante foi avaliada após 68 dias de tratamento por análises de evolução de CO2, redução de COT, decaimento de HTP, de n-alcanos e frações de hidrocarbonetos saturados, aromáticos e compostos polares. O tratamento BIOAS resultou na maior produção de CO2 acumulada (1247,0 mg.20g-1 de solo) seguida pelo tratamento BIOES (1077,6 mg.20g-1 de solo). Ao final do experimento, todos os tratamentos reduziram significativamente os teores de HTPs quando comparados ao controle (11,14,2%). Os tratamentos BIOAS e BIOES não apresentaram diferenças significativas quanto à redução de HTPs (42,03,7% e 37,46,3%, respectivamente). Tanto o bioestímulo quanto o bioaumento mostraram-se estratégias com potencial para aumentar a eficácia da biorremediação de solos argilosos, sendo que a adição de surfactante foi o fator mais importante, tendo aumentado significativamente a capacidade de remoção em ambas as estratégias. O uso de biorreatores em fase semi-sólida na biorremediação de solo argiloso contaminado com óleo lubrificante mostrou-se bastante promissor e tal estratégia pode ser aplicada em escala imediatamente superior
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No Brasil, a contaminação do solo por derramamentos de combustíveis representa um dos mais graves problemas ambientais e o impacto da introdução de novas misturas como diesel/biodiesel na matriz energética requer investigação quanto a tecnologias apropriadas de remediação. O presente estudo teve por objetivo avaliar diferentes estratégias de biorremediação no tratamento de solo contaminado experimentalmente com óleo diesel B5. Foram conduzidos três experimentos. No primeiro, quatro microcosmos em duplicata, contendo 500 g de solo e 5% (p/p) de óleo diesel B5, todos suplementados com oxigênio através de revolvimento manual e com ajuste de umidade, tiveram como tratamentos: bioestímulo com ajuste de pH (BE1); bioestímulo com ajuste de pH e nutrientes (BE2); bioaumento com ajuste de pH, nutrientes e adição de consórcio microbiano comercial KMA (BAM) e; controle abiótico, com ajuste de pH e solo esterilizado em autoclave (PA). Paralelamente, foi conduzido tratamento por bioaumento com ajuste de pH e nutrientes, suplementação de oxigênio e consórcio KMA, em solo contaminado apenas por diesel a 5% (BAD). A população microbiana foi monitorada através da contagem de UFC e os tratamentos, avaliados pela remoção de carbono orgânico e de hidrocarbonetos de petróleo (n-alcanos C10-C36). No segundo experimento, o metabolismo microbiano aeróbio foi avaliado através da produção de CO2 em respirômetros de Bartha (triplicatas), em solo contaminado com 5% (p/p) de óleo diesel B5, ajustado para pH e umidade, nas seguintes condições: solo com adição do consórcio KMA; solo com adição de cultura microbiana obtida a partir de outro solo proveniente de um posto de combustível com histórico de vazamento de tanques (RES) e; solo esterilizado por adição de azida de sódio a 0,3% (p/p). Como controle, solo sem contaminação, com sua população microbiana autóctone. No terceiro experimento, a capacidade da microbiota autóctone (EX), assim como do consórcio KMA e da cultura RES, em biodegradar óleo diesel B5, diesel e biodiesel de soja foi testada através do uso de indicadores de oxirredução DCPIP e TTC. Os experimentos em microcosmos indicam que houve uma complementaridade metabólica entre a população nativa e o consórcio comercial de microorganismos KMA, cuja presença promoveu um decaimento mais rápido de n-alcanos nas primeiras semanas do experimento. No entanto, após 63 dias de experimento, os tratamentos BAM, BAD e BE2 apresentaram, respectivamente, em média, 92,7%, 89,4% e 81,7% de remoção dos hidrocarbonetos n-alcanos C10-C36, sendo tais diferenças, sem significância estatística. Nos respirômetros, o bioaumento com cultura microbiana RES apresentou a maior produção de CO2 e a maior remoção de hidrocarbonetos (46,2%) após 29 dias. Tanto nos ensaios em microcosmos quanto nos respirométricos, não foi possível estimar a contribuição dos processos abióticos, tendo em vista evidências da existência de atividade microbiana no solo esterilizado térmica ou quimicamente. Os ensaios com os dois indicadores redox mostraram que apenas a microbiota nativa do solo em estudo e a cultura microbiana RES apresentaram potencial para degradar óleo diesel B5, biodiesel de soja ou diesel, quando colocadas em meio mineral contendo tais combustíveis como única fonte de carbono.
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As a result of increased population growth, the attraction of high profits from shrimp culture and ineffective mangrove forest management, a number of serious environmental problems exist in Ngoc Hien District, Minh Hai Province, Vietnam. These environmental problems are highlighted in this article.
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A necessidade de redução da emissão de poluentes, visando diminuir os sérios problemas de poluição atmosférica enfrentados atualmente, é hoje uma das principais preocupações mundiais, provocando o surgimento de leis mais rígidas, que restringem o teor de enxofre na gasolina e no diesel. Assim, o desenvolvimento de tecnologias mais eficazes na remoção de enxofre nestes combustíveis tem recebido atenção crescente. Estas tecnologias incluem a extração física com solvente, a adsorção seletiva, processos de redução/oxidação microbiológicos e a dessulfurização oxidativa (ODS). A dessulfurização oxidativa converte os compostos de enxofre em sulfonas que podem ser facilmente separadas por processos físicos. Portanto, a ODS apresenta grande potencial para tornar-se um processo complementar a processo de hidrodessulfurização tradicional na produção de combustíveis altamente dessulfurizados. Neste contexto, este trabalho visou o estudo do desempenho de catalisadores de V2O5 suportados em alumina, sílica e sílica-alumina frente à reação de ODS do dibenzotiofeno em presença do peróxido de hidrogênio, como oxidante, e da acetonitrila, como solvente polar aprótico. Os catalisadores foram preparados por impregnação ao ponto úmido e caracterizados por difração de raios-X (DRX), análise textural, redução à temperatura programada (TPR-H2), dessorção de amônia à temperatura programa (TPD-NH3) e espectroscopia Raman. O efeito de parâmetros reacionais como quantidade de solvente, relação O/S e concentração de catalisador foram investigados, utilizando a alumina como suporte, visando estabelecer as condições reacionais que levassem a maiores valores de conversão do dibenzotiofeno (DBT). Uma vez estabelecidas estas condições, foi analisado o efeito do teor de V2O5 presente no catalisador e, posteriormente, o efeito do suporte catalítico. Os resultados obtidos mostraram a 70 C razão molar H2O2/Sde 16,6, razão carga/solvente igual a 1:1 e 100 mg do catalisador 15 % V2O5/SiO2, a conversão obtida foi de 95%
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In the Philippines at present, milkfish farming in ponds includes a wide range of intensities, systems and practices. To make aquaculture possible, ecosystems are used as sources of energy and resources and as sinks for wastes. The growth of aquaculture is limited by the life-support functions of the ecosystem, and sustainability depends on matching the farming techniques with the processes and functions of the ecosystems, for example, by recycling some degraded resources. The fish farm has many interactions with the external environment. Serious environmental problems may be avoided if high-intensity farms are properly planned in the first place, at the farm level and at the level of the coastal zone where it can be integrated with other uses by other sectors. It is believed that the key to immediate success in the mass production of milkfish for local consumption and for export of value-added forms may be in semi-intensive farming at target yields of 3 tons per ha per year, double the current national average. Intensive milkfish farming will be limited by environmental, resource and market constraints. Integrated intensive farming systems are the appropriate long-term response to the triple needs of the next century: more food, more income, and more jobs for more people, all from less land, less resources, and less non-renewable energy.
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Invasive alien species have become one of the most serious environmental issues in the world. Data of taxon, origin, pathway, and environmental impacts of invasive alien microorganisms, invertebrates, amphibians and reptiles, fish, birds, mammals, herbs, trees, and, marine organisms in terrestrial, aquatic, and marine ecosystems of China were analyzed during 2001 and 2003, based on literature retrieval and field survey. There were 283 invasive alien species in China, and the number of species of invasive alien microorganisms, aquatic plants, terrestrial plants, aquatic invertebrates, terrestrial invertebrates, amphibians and reptiles, fish, and mammals were 19, 18, 170, 25, 33, 3, 10, and 5, respectively. The proportion of invasive alien species originated from America, Europe, Asia, Africa, and Oceania were 55.1, 21.7, 9.9, 8.1, and 0.6%, respectively. Methods for estimation of direct economic losses to agriculture, forestry, stockbreeding, fishery, road and water transportation, storage, water conservancy, environment and public facilities, and human health were established. Methods for estimation of indirect economic losses caused by invasive alien species to service functions of forest ecosystems, agricultural ecosystems, grassland ecosystems, and wetland ecosystems were also established. The total economic losses caused by invasive alien species to China were to the time of USD 14.45 billion, with direct and indirect economic losses accounting for 16.59% and 83.41% of total economic losses, respectively.
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Sand storm is a serious environmental threat to humans. Sand particles are transported by saltation and suspension, causing soil erosion in one place and deposition in another. In order to prevent and predict sand storms, the causes and the manners of particle motions must be studied in detail. In this paper a standard k-epsilon model is used for the gas phase simulation and the discrete element method (DEM) is used to predict the movements of particles using an in-house procedure. The data are summarized in an Eulerian-Eulerian regime after simulation to get the statistical particle Reynolds stress and particle collision stress. The results show that for the current case the Reynolds stress and the air shear stress predominate in the region 20-250 mm above the initial sand bed surface. However, in the region below 3 mm, the collision stress must be taken into account in predicting particle movement. (C) 2010 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.
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目前,随着全球气候变化的加剧,水分短缺更加明显。在干旱与半干旱地区,水分胁迫是影响植物存活和生长的主要限制因子。同时,随着大气平流层中臭氧浓度的减少,过量的紫外辐射(UV-B)到达地球表面,一些地区的植物不可避免地受到增强UV-B 和水分胁迫的共同作用。文献表明在UV-B 增强的情况下,干旱表现为减弱或增强UV-B 对植物的影响,这与种、品种有一定的相关性。另外,脱落酸(ABA)是近年来研究报道最多的信息调控物质,与植物抗旱性途径有较大的关系,但其对植株抗UV-B 的影响还有待于研究。本论文以滇杨(Populus yunnanensis)为模式植物,从形态和生理方面研究了增强UV-B、干旱和脱落酸对它的影响,并探讨了UV-B 与干旱的互作效应以及喷施脱落酸对植株抗旱性和抗UV-B 能力的影响。主要研究结果如下:1. 增强的UV-B 和干旱胁迫都影响了滇杨的形态生长和生理生化反应。它们都导致了滇杨植株的株高、基茎、整株叶面积、平均叶面积、总生物量和净光合速率的显著降低,使得叶片增厚,过氧化物酶(GPX)活性升高,脯氨酸和花色素苷含量增加,膜脂过氧化程度增大。不同的是干旱显著降低了植株叶片数目,增大了根/冠比(Rs)、细根/总根比(Ft)、提高了内源ABA 含量、碳同位素(δ13C)以及紫外吸收物质含量和超氧化物歧化酶(SOD)的活性,而UV-B 对它们没有影响。干旱与UV-B 的复合作用加剧了任一单独胁迫对植株的抑制,表现为更小的株高、基茎、整株叶面积、平均叶面积、总生物量,更低的光合作用和更高的MDA 含量。而且UV-B 辐射降低了干旱胁迫下生物量分配的可塑性,表现为降低了干旱情况下的Rs 和Ft,ABA 的含量也显著下降,复合胁迫下脯氨酸含量和过氧化氢酶(CAT)的活性比任一单独胁迫时都要低。这些实验结果表明,增强的UV-B 与干旱的复合胁迫加剧了对植株的抑制作用。II2. 干旱情况下同时施加外源ABA 提高了植株的根/冠比、细根/总根比和单位面积叶重,即提高了干旱胁迫下植株对生物量分配的可塑性。而且外源ABA 使干旱胁迫下的长期用水效率、ABA 含量、脯氨酸含量、GPX 活性进一步增加,并有效调节了活性氧代谢的平衡,抑制了受旱植株MDA 的增加。结果表明,外源ABA 的喷施提高了滇杨植株的抗旱性。3. 在增强的UV-B 情况下,外源ABA 加剧了UV-B 对滇杨形态生长的抑制效果,表现为进一步降低了滇杨植株的整株叶面积、平均叶面积、单位面积叶重和总生物量,而且ABA 还降低了UV-B 胁迫下的净光合速率和脯氨酸的含量,增大了MDA 的含量。通过以上的数据我们可以看出,外源ABA 虽然提高了滇杨植株的抗旱性,但却加剧了UV-B 胁迫对植株的抑制作用。Currently, drought is one of the most serious environmental stresses. In arid and semi-aridregions, drought is a major constraint imposed on tree survival and growth. The decrease ofozone layer leads to a significant increase in ultraviolet-B (UV-B, 280-320 nm) radiationreaching the earth surface. In some places, plants suffer both UV-B and water stresssimultaneously. Their combination will increase or decrease the sensitivity of plants to UV-Bstress which lies on the species. On the other hand, abscisic acid (ABA), as a plant homoneand growth regulator, is better for plants resistant to drought stress, but it is uncleared aboutthe relationship between exogenous ABA and supplemental UV-B. In the present study, weemployed Populus yunnanensis Dode as a model species to characterize the growth andecophysiological responses of woody plants to supplemental UV-B, drought and exogenous ABA. The results are as follows:1. Both supplemental UV-B and drought affected the morphological, physiological andbiochemical responses of P. yunnanensis. They decreased the plant height, basal diameter,total leaf area, average leaf area, biomass and photosynthesis, and increased specific leaf mass,the activity of guaiacol peroxidase (GPX), the content of proline, anthocyanins andmalondialdehyde (MDA). However, drought decreased the leaf number and increasedroot/shoot ratio, fine root/total ratio, the activity of superoxide dimutase (SOD) and thecontents of ABA, carbon isotope composition (δ13C), UV-absorbing compounds. Whilesupplemental UV-B had no effects on them. The combination of drought and UV-Baugmented the growth inhibtion acting as further lower plant height and smaller basaldiameter, leaf area, biomass and higher MDA content. And compared with drought stress,root/shoot ratio and fine root/total root ratio decreased under the combination stresses. The photosynthesis, proline content and Catalase (CAT) activity became lower under combinationstresses than that of either stress lonely. According to these results, we suggested that,compared with the effect of stress lonely, the combination of supplemental UV-B and droughtdid not mitigate the harmful effect, but augmented it.2. Under drought conditions, exogenous ABA increased root/shoot ratio, fine root/total rootratio and the specific leaf mass. That was to say exogenous ABA increased plant plasticityunder drought conditions. Also ABA content, proline content, activity of GPX and δ13C wereenhanced further. In addition the enhancement of MDA was restrained. So the resultssuggested that exogenous ABA increased the seedling capacity of resistance to drought.3. Under supplemental UV-B conditions, exogenous ABA augmented the growth restrain ofUV-B to seedlings, which acted as further decreased leaf area, specific leaf mass and biomass.Compared with UV-B stress alone, proline content and photosynthesis were decreased andMDA content was increased under the combination of UV-B and ABA. These resultssuggested that although exogenous ABA increased the seedling capacity of resistance todrought, it augmented the growth restrain of supplemental UV-B to P. yunnanensis.
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人类活动引起全球大气中温室气体(CO2、CH4、NOx)浓度不断增加,致使地球表面温度在过去的100 年中已经增长了0.74 ± 0.18℃,预计到本世纪末将会增加1.1-6.4℃。此外,氮沉降也是当今社会的重要环境问题,随着经济发展的全球化, 高氮沉降也呈现出全球化趋势。全球气候变暖和氮沉降给陆地生态系统的地上、地下生物学和生物地球化学过程所带来巨大影响越来越引起人们的关注。 本文以川西亚高山针叶林的两个重要树种云杉和油松幼苗为研究对象,采用红外辐射增温(空气增温2.1℃,土壤增温2.6℃)和根部施氮(施氮量25 g N m-2yr-1)的方法,从生长形态、光合作用、抗氧化能力和矿质营养等方面研究这两种幼苗对气候变暖和氮沉降的响应。该实验为室外控制实验,包括四个处理:(1)不增温+不施氮(UU);(2) 不增温+施氮(UF);(3) 增温+不施氮(WU);(4) 增温+施氮(WF)。本研究旨在从生理生化、物质代谢 、生长及形态等不同水平上研究模拟增温和施氮对两种树苗的联合效应,提高我们对全球变化下亚高山针叶林早期更新过程的理解,同时也为森林管理提供科学依据。具体研究结果如下: 单独增温处理显著提高了云杉和油松幼苗的地茎、叶重、茎重、根重以及总生物量;单独施氮处理也增加了两种幼苗的株高和总生物量。而增温和施氮联合作用对两种幼苗生长的影响并不相同,联合作用对云杉幼苗生长指标的正效应显著低于单独施氮处理,但是联合作用比单独增温或施氮更大程度的促进了油松幼苗生物量的积累。 单独增温和施氮都有利于提高云杉和油松叶片中叶绿素含量、净光合速率(A)、最大净光合速率(Amax)、表观量子效率(Φ)、最大光能转化效率(Fv/Fm)和量子产量(Y)。与对两种幼苗生长指标的影响相似,加氮和增温共同作用下油松幼苗的以上光合指标比在单独增温或施氮处理下有更大程度的提高;而联合作用下云杉幼苗叶绿素含量、净光合速率、最大净光合速率、表观量子效率、最大光能转化效率以及量子产量比单独施氮处理明显地降低。 增温和施氮都显著地降低了云杉和油松幼苗针叶组织中活性氧和丙二醛的积累。交互作用降低了云杉幼苗叶片的抗氧化酶活性、脯氨酸和ASA 的含量,却显著提高了油松幼苗SOD、POD、APX 等抗氧化酶的活性,并且对油松幼苗脯氨酸和ASA 积累的促进作用比单一因子更加明显。因此,增温和施氮共同作用下油松幼苗叶片中O2-产生速率、H2O2 及MDA 含量明显降低,而云杉叶片中只有O2-产生速率出现降低趋势。 增温和施氮都降低了云杉体内的P、Ca、Mg 元素的含量,增加了Cu、Zn、Mn 在各器官内的积累。对油松幼苗而言,增温和加氮单独作用也显著降低了Ca 含量增加了Cu、Zn、Mn 的积累,但是不同于云杉幼苗的是P、Mg 也显著增加。增温和施氮联合作用对云杉幼苗体内元素的影响与单一施氮处理或增温处理相似,不同的是比单一因子作用更为明显降低了P、Ca、Mg 含量,增加了植株中N、Cu、Zn、Mn 的含量,但是油松矿质元素含量在联合作用下并没有产生类似于云杉幼苗的双因子叠加效应。 总之,尽管单独增温或者施氮都有利于云杉和油松幼苗生长指标、光合能力以及抗氧化能力的提高。但是,增温和施氮对云杉幼苗生长生理的促进效应非但没有在交互作用下有更大的提高,反而低于单独氮处理。与此不同的是,增温和施氮联合作用比单因子作用更有利于油松幼苗生长及生理指标的提高。 With the continued increase in atmospheric concentrations of greenhouse gases (CO2、CH4、NOx), the mean global surface temperature has increased by about 0.74 ± 0.18℃ over the past century and is predicted to rise by as much as 6.4℃ during this century. Besides global warming, nitrogen deposition is another serious environmental problem caused by human activities, and high nitrogen load has become globalization as a result of global economy development. Global climate warming and nitrogen deposition have induced dramatic alternations in above - and below- ground biology and biogeochemistry process in terrestrial ecosystems, and more and more attention has been invited to those problems. This experiment mainly studies two important species Picea asperata and Pinus tabulaeformis in subalpine coniferous forest of western Sichuan, China. Infared heaters are induced to increase both air and soil temperature by 2.1℃ and 2.6 ℃, respectively. Ammonium nitrate solution (for a total equivalent to 25 g N m-2 year-1) is added to soil surface. There are four treatments in this study: (1) unwarmed unfertilized (UU); (2) unwarmed fertilized (UF); (3) warmed unfertilized (WU); (4) warmed fertilized (WF). This study is conducted to determine the influences of experimental warming and nitrogen fertilization on physiolchemistry, nutrition metabolism, growth and morphology in the two coniferous species seedlings. The current study is favorable for increasing our understanding on the early phase of regeneration behavior in subalpine coniferous forest, and it also provide scientific direction for forest management under future global changes. The results are as follows: Artificial warming alone significantly increased basal diameter, leaf mass, stem mass, root mass and total biomass for Picea asperata and Pinus tabulaeformis seedlings, and single nitrogen fertilization are also favorable for growth of the two species and stimulate plant hight and total biomass. The two species seedlings respond differently to the combination of elevated temperature and nitrogen addition. Warming combined with nitrogen fertilization weakens the positive effects of nitrogen addition for growth of Picea asperata seedlings. However, the combination of elevated temperature and nitrogen fertilization further increase biomass accumulation of Pinus tabulaeformis seedlings. Both elevated temperature alone and nitrogen fertilization alone can increase photosynthetic pigments contents, net photosynthetic rate (A), maximum net photosynthetic rate (Amax), apparent quantity yield (Φ), maximum photochemical efficiency of photosystem II (Fv/Fm) and effective quantum yield (Y). Similarly with growth parameters, the combination of warming and nitrogen addition induced more increment of these above photosynthetic parameters for Pinus tabulaeformis seedlings. However, these photosynthetic parameters of Picea asperata seedlings under the combination of warming and nitrogen addition are lower than those under nitrogen fertilization alone. The levels of active oxygen species (AOS) and malodiadehyde (MDA) in needles of the two coniferous species seedling are obviously decreased by experimental warming or additional nitrogen. Warming combined with nitrogen fertilizer reduces the activities of SOD, CAT and APX, and the contents of proline and ASA of Picea asperata seedlings, but the combination significantly increases activities of these antioxidant enzymes in needlels of Pinus tabulaeformis seedlings and further improves the accumulation of proline and ASA compared to either artificial warming or nitrogen addition. Therefore, the rate of O2 - production, the contents of H2O2 and MDA in needles of Pinus tabulaeformis seedlings are remarkably reduced by the combination of warming and nitrogen addition, but the combination only significantly decreased the rate of O2 - production of Picea asperata seedlings. Elevated temperature or nitrogen fertilization decrease the contents of P, Ca, Mg but increase Cu, Zn, Mn contents for Picea asperata seedlings. For Pinus tabulaeformis seedlings, elevated temperature alone and nitrogen fertilization alone decreased Ca, but increased P, Mg, Cu, Zn, Mn contents. The effects of the combination of warming and nitrogen addition on these element contents in needles of Picea asperata seedlings are added or multiplied the effects of warming and nitrogen addition alone, resulting in less contens of P, Ca, Mg and more contents of Cu, Zn, Mn than either elevated temperature or nitrogen fertilization. Howere, these adding or multipluing single-factor effects on contents of these elements are not observed in the case of Pinus tabulaeformis seedlings. In conclusion, growth parameters, photosynthetic capacities and antioxidant abilities of Picea tasperata and Pinus abulaeformis seedlings are improved by experimental warming or nitrogen fertilization. Interestingly, the positive effects of warming and nitrogen addition on growth and physiological performances are not multiplied by the combination of elevated temperature and nitrogen fertilization, even dempened for Picea asperata seedlings. However, for Pinus tabulaeformis seedlings, growth and physiological performances are further improved by the combination.
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Gemstone Team GREEN JUSTICE
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Dissertação de Mestrado apresentado ao Instituto de Contabilidade e Administração do Porto para a obtenção do grau de Mestre em Empreendedorismo e Internacionalização, sob orientação de Maria Clara Dias Pinto Ribeiro
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Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização de Vias de Comunicação e Transportes
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Urban developments have exerted immense pressure on wetlands. Urban areas are normally centers of commercial activity and continue to attract migrants in large numbers in search of employment from different areas. As a result, habitations keep coming up in the natural areas / flood plains. This is happening in various Indian cities and towns and large habitations are coming up in low-lying areas, often encroaching even over drainage channels. In some cases, houses are constructed even on top of nallahs and drains. In the case of Kochi the situation is even worse as the base of the urban development itself stands on a completely reclaimed island. Also the topography and geology demanded more reclamation of land when the city developed as an agglomerative cluster. Cochin is a coastal settlement interspersed with a large backwater system and fringed on the eastern side by laterite-capped low hills from which a number of streams drain into the backwater system. The ridge line of the eastern low hills provides a welldefined watershed delimiting Cochin basin which help to confine the environmental parameters within a physical limit. This leads to an obvious conclusion that if physiography alone is considered, the western flatland is ideal for urban development. However it will result in serious environmental deterioration, as it comprises mainly of wetland and for availability of land there has to be large scale filling up of these wetlands which includes shallow mangrove-fringed water sheets, paddy fields, Pokkali fields, estuary etc.Chapter 1 School 4 of Environmental Studies The urban boundaries of Cochin are expanding fast with a consequent over-stretching of the existing fabric of basic amenities and services. Urbanisation leads to the transformation of agricultural land into built-up areas with the concomitant problems regarding water supply, drainage, garbage and sewage disposal etc. Many of the environmental problems of Cochin are hydrologic in origin; like water-logging / floods, sedimentation and pollution in the water bodies as well as shoreline erosion
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A recently emerging bleeding canker disease, caused by Pseudomonas syringae pathovar aesculi (Pae), is threatening European horse chestnut in northwest Europe. Very little is known about the origin and biology of this new disease. We used the nucleotide sequences of seven commonly used marker genes to investigate the phylogeny of three strains isolated recently from bleeding stem cankers on European horse chestnut in Britain (E-Pae). On the basis of these sequences alone, the E-Pae strains were identical to the Pae type-strain (I-Pae), isolated from leaf spots on Indian horse chestnut in India in 1969. The phylogenetic analyses also showed that Pae belongs to a distinct clade of P. syringae pathovars adapted to woody hosts. We generated genome-wide Illumina sequence data from the three E-Pae strains and one strain of I-Pae. Comparative genomic analyses revealed pathovar-specific genomic regions in Pae potentially implicated in virulence on a tree host, including genes for the catabolism of plant-derived aromatic compounds and enterobactin synthesis. Several gene clusters displayed intra-pathovar variation, including those encoding type IV secretion, a novel fatty acid biosynthesis pathway and a sucrose uptake pathway. Rates of single nucleotide polymorphisms in the four Pae genomes indicate that the three E-Pae strains diverged from each other much more recently than they diverged from I-Pae. The very low genetic diversity among the three geographically distinct E-Pae strains suggests that they originate from a single, recent introduction into Britain, thus highlighting the serious environmental risks posed by the spread of an exotic plant pathogenic bacterium to a new geographic location. The genomic regions in Pae that are absent from other P. syringae pathovars that infect herbaceous hosts may represent candidate genetic adaptations to infection of the woody parts of the tree.