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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Caracterização fenotípica e molecular de Escherichia coli isolodas de amostras de água do mar da região costeira de São Paulo, Brasil. / Phenotypic and molecular characterization of Escherichia coli isolated from seawater samples from the coastal region of the state of São Paulo, Brazil.

Silva, Vanessa Feitosa Viana da 18 May 2015 (has links)
A qualidade das águas marinhas destinadas a recreação de contato primário pode ser afetada por fontes de poluição pontuais e não pontuais. Escherichia coli é membro comensal da microbiota intestinal de humanos e animais endotérmicos e quando presente no ambiente marinho indica contaminação fecal recente. Embora a maioria das cepas desta espécie não seja patogênica para o homem, existem isolados virulentos e/ ou resistentes aos antibióticos. E.coli pode ser caracterizada em grupos filogenéticos - GF (A, B1, B2, C, D, E, F e clado I) e em categorias diarreiogênicas (ETEC, EPEC, EHEC, EIEC, EAEC e DAEC). Este trabalho objetivou caracterizar 99 isolados de E.coli obtidos de amostras água do mar de três regiões costeiras do estado de São Paulo com diferentes níveis de contaminação [Ubatuba (UBA), oligotrófico (n=20); Baixada Santista (BS), eutrófico (n=30) e canal de São Sebastião (CSS), mesotrófico (n=49)], frente à susceptibilidade aos antibióticos, GF, genes associados à virulência (GAV) e assim estimar os riscos microbiológicos à balneabilidade dos locais de coleta. A susceptibilidade a ampicilina (AMP), amoxicilina- ácido clavulânico (AMC), amicacina (AMI), cefotaxima (CTX), cefuroxima (CRX), ciprofloxacino (CIP), cloranfenicol (CLO), imipenema (IPM), piperacilina-tazobactam (PPT), sulfametoxazol-trimetropima (SUT) e tetraciclina (TET) foi determinada pelo método de disco difusão. A classificação em GF foi realizada por PCR utilizando duas metodologias (CLERMONT et al., 2000 e 2011). Os GAV (stx1, stx2, eae, bfpA, aggR, elt, esth, estp, invE e astA) foram pesquisados por PCR. Os resultados foram utilizados na avaliação do risco microbiológico por QMRA. Dezenove isolados foram resistentes a AMP, sendo UBA (3%), BS (33%) e CSS (16%). Dezessete isolados foram resistentes a TET: UBA (20%), BS (23%) e CSS (12%); 14 isolados foram resistentes a SUT: UBA e CSS (10%) e BS (23%). As frequências (%) dos GF (Clermont ET AL., 2000) comensais A e B1 foram, respectivamente (55 e 15 em UBA; 63 e 13 na BS; 69 e 8 no CSS); já as frequências (%) dos GF virulentos B2 e D foram, respectivamente, 5 e 25 em UBA; 7 e 16 na BS; 4 e 18 no CSS. As frequências (%) dos GF (CLERMONT et al., 2013) comensais A, B1 e C foram: respectivamente: (15, 15 e 5 em UBA; 20, 3 e 3 na BS; 2, 10 e 2 no CSS), já os grupos mais virulentos (B2, D, E e F) foram, respectivamente: (15, 15, 0 e 10 em UBA; 13, 27, 0 e 10 na BS; 10, 33, 8 e 18 no CSS); as frequências do clado I em UBA, BS e CSS foram respectivamente: (15, 23 e 12). Os GAV detectados em UBA foram: astA (15%) e bfpA (5%); BS: esth (3%) e astA (30%) e no CSS: stx1 (2%), eae (4%), estp (2%) e astA (47). Embora não tenha sido detectado risco à balneabilidade, observou-se isolados resistentes e GF virulentos em todos os pontos de coleta, dessa forma, esses ambientes devem ser conservados para assegurar a saúde ambiental e humana, além disso a QMRA não representou o risco total de todos micro-organismos e patógenos oportunistas presentes nessas regiões. / The quality of seawater intended for bathing can be affected by sources of point and non-point pollution. In this pollutants may be Escherichia coli. E.coli is a commensal member of the intestinal tract of humans and endothermic animals, and when present in the marine environment indicates recent fecal contamination. Although most strains are harmless, there are virulent and/or resistant to antibiotics. E. coli can be evaluated by phylogenetic groups - PG (A, B1, B2, C, D, E, F, clade 1) and diarrheagenic categories (ETEC, EPEC, EHEC, EIEC, EAEC and DAEC). The aim of the present study was to characterize 99 E. coli isolated from seawater samples from three coastal regions of the state of São Paulo with different levels of contamination [Ubatuba (UBA), oligotrophic (n=20); Santos (BS), eutrophic (n=30) and São Sebastião Channel (CSS), mesotrophic (n=49)], in regard to antibiotics susceptibility, PG, virulence genes (VGs) associated with diarrheagenic pathotypes and to estimate the microbiological risks to bathing. The susceptibility to ampicillin (AMP), amoxicillin-clavulanic acid (AMC), amikacin (AMI), cefotaxime (CTX), cefuroxime (CRX), ciprofloxacin (CIP), chloramphenicol (CLO), imipenem (IPM), piperacillin-tazobactam (PPT), trimethoprim-sulfamethoxazole (SUT) and tetracycline (TET) was determined by disk diffusion. The classification in regard to GF was performed by PCR using two methodologies (2000 and 2013). The VGs (stx1, stx2, eae, bfpA, aggR, elt, esth, estp, invE and astA) were screened by PCR and the results were used to evaluate the microbiological risk by QMRA. Nineteen isolates were resistant to AMP: UBA (3%), BS (33%) and CSS (16%). Seventeen isolates were resistant to TET: UBA (20%), BS (23%) and CSS (12%); 14 isolates were resistant to the SUT: UBA and CSS (10%) and BS (23%). By the methodology of 2000, the frequencies (%) of commensals PG and B1 were, respectively, (55 and 15 in UBA; 63 and 13 in BS; 69 and 8 in CSS); while the frequencies (%) of virulent PG, B2 and D were, respectively (5 and 25 in UBA; 7 and 16 in BS; 4 and 18 in CSS). By the methodology of 2013, the frequencies (%) of PG commensals A, B1 and C were, respectively: (15, 15 and 5 in UBA; 20, 3 and 3 in BS; 2, 10 and 2 in CSS), on the other hand, the most virulent groups (B2, D, E and F) were, respectively: (15, 15, 0 and 10 in UBA; 13, 27, 0 and 10 in BS; 10, 33, 8 and 18 in CSS); clade 1 frequencies in UBA, BS and CSS were, respectively (15, 23 and 12). The VGs were detected in UBA; astA (15%) and bfpA (5%); BS: esth (3%) and astA (30%) and CSS: stx1 (2%), eae (4%), estp (2%) and astA (47). Although no microbiological hazard was detected to bathing, was observed resistant isolates and virulent PG, thereby these environments should be preserved to ensure the environmental and human health, moreover the QMRA did not represent the overall risk of all microorganisms and opportunistic pathogens present in these regions.
42

Avaliação da contaminação por hidrocarbonetos e organoclorados em diferentes compartimentos do ambiente marinho do Estado do Rio de Janeiro / Evaluation of the contamination of several compartiments of marine environment of the State of Rio de Janeiro by hidrocarbons and organochlorine

Taniguchi, Satie 31 October 2001 (has links)
O ambiente marinho é o destino final de muitos contaminantes, como os PAHs, PCBs, DDTs e HCHs, que têm sido detectados em vários compartimentos do ambiente marinho, podendo trazer efeitos deletérios para o ecossistema. O objetivo deste trabalho foi a avaliação da contaminação por hidrocarbonetos alifáticos, PAHs, PCBs, DDTs e HCHs através da análise de 15 amostras de sedimento, 6 de mexilhão e 11 de fígado de peixe. Para isso, foi otimizada uma mesma metodologia para todas as matrizes bióticas. A amostragem foi feita ao longo da costa do estado do Rio de Janeiro, no período de 1996 a 1998, durante o Programa de Monitoramento do Ambiente do Meio Ambiente Marinho, promovido pela Marinha do Brasil. Os controles de qualidade analítica e confiabilidade dos dados gerados seguiram os padrões internacionais. A metodologia utilizada foi considerada satisfatória para análise dos organismos e sedimentos, de acordo com a avaliação feita através da análise de materiais de referência certificados. Os PCBs e DDTs apresentaram o fenômeno da magnificação com concentrações crescentes: sedimentos < mexilhões < peixes. Os HCHs apresentaram as maiores concentrações nos mexilhões. Os hidrocarbonetos alifáticos apresentaram concentrações similares nas três matrizes amostradas, o mesmo ocorrendo com os PAHs. As concentrações de hidrocarbonetos do petróleo indicam que as maiores introduções são próximas às áreas urbanas. Os PCBs e pesticidas também foram detectados em grande parte das amostras, mas em baixas concentrações. A fonte desses OCs para o ambiente marinho pode ser oriunda de outras regiões devido ao transporte e à deposição atmosférica. A comparação entre as matrizes mostrou a importância da análise simultânea de sedimentos e organismos em função da concentração de cada grupo de compostos e sua diferente acumulação. / The marine environment is the final recipient of many organic compounds that are widely found in seawater, sediments and organisms. The purpose of this study was the assessment of the contamination of aliphatic hydrocarbons, PAHs, PCBs, DDTs and HCHs through the analyses of 15 sediments, 6 mussels and 11 fish livers. The same methodology was optimized for biotic matrices. The sampling was performed from 1996 to 1998 along the Coast of the State of Rio de Janeiro, during the Brazilian Navy Environmental Monitoring Program. Quality assurance and quality control followed the international procedures. The methodology give satisfactory results in accord with the analyses of certified standard reference materials. Data of PCBs and DDTs from different matrices revealed increasing concentrations: sediment < mussel < fish. HCHs prevailed in mussels. Data of aliphatic hydrocarbons and PAHs were similar between sediments and organisms. Levels of petroleum hydrocarbons showed major inputs near the urban areas. PCBs and chlorinated pesticides were detected in the majority of samples but in low levels. These inputs can be attributed to long-range atmospheric transport. Comparison among the sampled matrices showed the importance of simultaneous analyses of sediments and organisms based in the concentration of each group of compounds and their different accumulations.
43

La gestion des risques maritimes environnementaux : contribution au renforcement de la protection de l'environnement marin / Maritime risk management : contribution to the strenghening of the protection of the maritime environment

Lasmoles, Olivier 19 May 2014 (has links)
Le retentissement des catastrophes maritimes de ces dernières années, Erika, Prestige, Deepwater Horizon, a confirmé l’importance des enjeux de pollution marine, tant auprès du grand public que des décideurs politiques. Aucune leçon n’aurait-elle été tirée de ces précédents? Les appels à une prise en compte accrue de la protection de l’environnement n’auraient eu que peu d’impact sur les pratiques des transporteurs et armateurs. Les atteintes à l’environnement marin doivent être au plus vite jugulées et ce grâce à des outils adaptés et efficaces. Or, le droit maritime, droit relatif à la navigation qui se fait sur la mer, ne serait plus en mesure de protéger correctement son environnement car fondé sur des principes de responsabilité civile. L’évolution des nécessités recommanderait que lui soient substitués les principes issus du droit commun de l’environnement, fondé sur la responsabilité pénale. Dans un premier temps, l’identification des risques maritimes, anciens comme contemporains, démontre que malgré une évolution certaine des technologies et un accroissement de leur complexité, ceux-ci demeurent fondamentalement identiques, avec en toile de fond le marin, le naviguant agissant dans le cadre d’une organisation. Dans un second temps, l’analyse du traitement des risques techniques démontre, en premier lieu, la capacité du droit maritime à se réformer en s’inspirant des bonnes pratiques issues de l’industrie offshore., L’analyse des risques juridiques confirme, en second lieu, que le droit maritime, malgré ses imperfections, possède les ressources pour se réformer et répondre aux attentes contemporaines en matière environnementale. / The impact of the maritime catastrophes of recent years such as Erika, Prestige, and Deepwater Horizon, has confirmed the concerns regarding marine pollution, both with the general public and political decision-makers. Has no lesson been learned from these events? Calls for greater awareness for environmental protection have had little impact on the practices of transporters and shipowners. Violations of the marine environment must be halted as soon as possible, using suitable and effective methods. Maritime law, which relates to navigation by sea, is no longer able to protect the environment because it is based on principles of civil responsibility. Changes in obligations suggest that this should be replaced by principles derived from common law on the environment, based on criminal responsibility. In the first part, the identification of maritime risks, both old and contemporary, demonstrates that in spite of some developments in technology and an increase in its complexity, it remains fundamentally identical, with the backdrop of the sailor, the navigator, acting within the framework of an organization. In the second part, the analysis of the treatment of technical risks demonstrates, firstly, the capacity of maritime law to reform, taking the lead from good practice derived from the offshore industry. Secondly, the analysis of legal risks confirms that maritime law, in spite of its imperfections, has the resources to reform and respond to contemporary expectations in environmental matters.
44

The contributions of UNCLOS dispute settlement bodies to the development of the law of the sea

Nguyen, Lan Ngoc January 2019 (has links)
This thesis seeks to systematically examine the contributions made by the dispute settlement bodies established under the United Nations Convention on the Law of the Sea (UNCLOS) to the development of the law of the sea. The two main research questions to be answered are: (i) what kind of contribution have UNCLOS dispute settlement bodies made to the development of the law of the sea? and (ii) what are the factors that impact the performance of UNCLOS dispute settlement bodies in developing the law of the sea? To that end, Chapter 1 provides a working definition for the concept of 'judicial development of international law' in order to establish a framework for an assessment of the contributions of UNCLOS tribunals. Based on this working definition, Chapters 2, 3 and 4 examine the significance of UNCLOS tribunals' decisions in the development of three main areas of the law of the sea, respectively the law on fisheries, the law on the outer continental shelf and the law on marine environmental protection. Based on the findings of these chapters, Chapter 5 analyses the factors that help explain the contributions of UNCLOS tribunals to the law of the sea as identified in the preceding chapters. These factors include: (i) the jurisdictional scope of UNCLOS tribunals, (ii) the institutional design of UNCLOS, (iii) the interpretative method employed by UNCLOS tribunals in deciding their cases and (iv) the perception that UNCLOS tribunals hold regarding their roles. Chapter 6 concludes by taking stock of the contribution of UNCLOS tribunal in these areas and offering some final observations on the role of UNCLOS tribunals in the development of the law of the sea.
45

Computer vision for continuous plankton monitoring / Visão computacional para o monitoramento contínuo de plâncton

Matuszewski, Damian Janusz 04 April 2014 (has links)
Plankton microorganisms constitute the base of the marine food web and play a great role in global atmospheric carbon dioxide drawdown. Moreover, being very sensitive to any environmental changes they allow noticing (and potentially counteracting) them faster than with any other means. As such they not only influence the fishery industry but are also frequently used to analyze changes in exploited coastal areas and the influence of these interferences on local environment and climate. As a consequence, there is a strong need for highly efficient systems allowing long time and large volume observation of plankton communities. This would provide us with better understanding of plankton role on global climate as well as help maintain the fragile environmental equilibrium. The adopted sensors typically provide huge amounts of data that must be processed efficiently without the need for intensive manual work of specialists. A new system for general purpose particle analysis in large volumes is presented. It has been designed and optimized for the continuous plankton monitoring problem; however, it can be easily applied as a versatile moving fluids analysis tool or in any other application in which targets to be detected and identified move in a unidirectional flux. The proposed system is composed of three stages: data acquisition, targets detection and their identification. Dedicated optical hardware is used to record images of small particles immersed in the water flux. Targets detection is performed using a Visual Rhythm-based method which greatly accelerates the processing time and allows higher volume throughput. The proposed method detects, counts and measures organisms present in water flux passing in front of the camera. Moreover, the developed software allows saving cropped plankton images which not only greatly reduces required storage space but also constitutes the input for their automatic identification. In order to assure maximal performance (up to 720 MB/s) the algorithm was implemented using CUDA for GPGPU. The method was tested on a large dataset and compared with alternative frame-by-frame approach. The obtained plankton images were used to build a classifier that is applied to automatically identify organisms in plankton analysis experiments. For this purpose a dedicated feature extracting software was developed. Various subsets of the 55 shape characteristics were tested with different off-the-shelf learning models. The best accuracy of approximately 92% was obtained with Support Vector Machines. This result is comparable to the average expert manual identification performance. This work was developed under joint supervision with Professor Rubens Lopes (IO-USP). / Microorganismos planctônicos constituem a base da cadeia alimentar marinha e desempenham um grande papel na redução do dióxido de carbono na atmosfera. Além disso, são muito sensíveis a alterações ambientais e permitem perceber (e potencialmente neutralizar) as mesmas mais rapidamente do que em qualquer outro meio. Como tal, não só influenciam a indústria da pesca, mas também são frequentemente utilizados para analisar as mudanças nas zonas costeiras exploradas e a influência destas interferências no ambiente e clima locais. Como consequência, existe uma forte necessidade de desenvolver sistemas altamente eficientes, que permitam observar comunidades planctônicas em grandes escalas de tempo e volume. Isso nos fornece uma melhor compreensão do papel do plâncton no clima global, bem como ajuda a manter o equilíbrio do frágil meio ambiente. Os sensores utilizados normalmente fornecem grandes quantidades de dados que devem ser processados de forma eficiente sem a necessidade do trabalho manual intensivo de especialistas. Um novo sistema de monitoramento de plâncton em grandes volumes é apresentado. Foi desenvolvido e otimizado para o monitoramento contínuo de plâncton; no entanto, pode ser aplicado como uma ferramenta versátil para a análise de fluídos em movimento ou em qualquer aplicação que visa detectar e identificar movimento em fluxo unidirecional. O sistema proposto é composto de três estágios: aquisição de dados, detecção de alvos e suas identificações. O equipamento óptico é utilizado para gravar imagens de pequenas particulas imersas no fluxo de água. A detecção de alvos é realizada pelo método baseado no Ritmo Visual, que acelera significativamente o tempo de processamento e permite um maior fluxo de volume. O método proposto detecta, conta e mede organismos presentes na passagem do fluxo de água em frente ao sensor da câmera. Além disso, o software desenvolvido permite salvar imagens segmentadas de plâncton, que não só reduz consideravelmente o espaço de armazenamento necessário, mas também constitui a entrada para a sua identificação automática. Para garantir o desempenho máximo de até 720 MB/s, o algoritmo foi implementado utilizando CUDA para GPGPU. O método foi testado em um grande conjunto de dados e comparado com a abordagem alternativa de quadro-a-quadro. As imagens obtidas foram utilizadas para construir um classificador que é aplicado na identificação automática de organismos em experimentos de análise de plâncton. Por este motivo desenvolveu-se um software para extração de características. Diversos subconjuntos das 55 características foram testados através de modelos de aprendizagem disponíveis. A melhor exatidão de aproximadamente 92% foi obtida através da máquina de vetores de suporte. Este resultado é comparável à identificação manual média realizada por especialistas. Este trabalho foi desenvolvido sob a co-orientacao do Professor Rubens Lopes (IO-USP).
46

海洋環境において腐食した鋼管の形状計測と残存耐力に関する検討

田村, 功, Tamura, Isao, 渡邊, 英一, Watanabe, Eiichi, 伊藤, 義人, Itoh, Yoshito, 藤井, 堅, Fujii, katashi, 野上, 邦栄, Nogami, Kuniei, 杉浦, 邦征, Sugiura, kunitomo, 永田, 和寿, Nagata, kazutoshi, 岡, 扶樹, Oka, Tomoki 03 1900 (has links)
No description available.
47

Corrosion-induced release of zinc and copper in marine environments

Sandberg, Jan January 2006 (has links)
<p>This licentiate study was initiated by copper, zinc and galvanized steel producers in Europe, who felt a need to assess runoff rates of copper and zinc from the pure metals and commercial products at marine exposure conditions. Their motive was the increasing concern in various European countries and the on-going risk assessments of copper and zinc within the European commission. Also the circumstance that available runoff rates so far, had been reported for mainly urban exposure conditions, rather than marine. A collaboration was therefore established with the French Corrosion Institute, which runs a marine test site in Brest, and a set of vital questions were formulated. Their answers are the essence of this licentiate study.</p><p>Based on the ISO corrosivity classification and one-year exposures, the marine atmosphere of Brest is fairly corrosive for zinc (class C3) and highly corrosive for copper (C4). Despite higher corrosivity classifications for both metals in Brest compared to the urban site of Stockholm, used as a reference site, nearly all runoff rates assessed for copper, zinc and their commercial products were lower in Brest compared to Stockholm. This was attributed to a higher surface wetting in Brest and concomitant higher removal rate of deposited chloride and sulphate species from the marine-exposed surfaces. The comparison shows that measured corrosion rates cannot be used to predict runoff rates, since different physicochemical processes govern corrosion and runoff respectively.</p><p>For copper, the runoff rate in Brest was approximately 1.1 g m<sup>-2</sup> yr<sup>-1</sup> with cuprite (Cu2O) as main patina constituent. During periods of very high chloride and sulphate deposition, paratacamite (Cu<sub>2</sub>Cl(OH)<sub>3</sub>) formed which increased the runoff rate to 1.5 g m<sup>-2</sup> yr<sup>-1</sup>. For zinc, with hydrozincite (Zn<sub>5</sub>(CO<sub>3</sub>)2(OH)<sub>6</sub>) as the main patina constituent, the runoff rate was relatively stable at 2.6 g m<sup>-2</sup> yr<sup>-1</sup> throughout the year, despite episodes of heavy chloride and sulphate deposition.</p><p>The application of organic coatings of varying thickness on artificially patinated copper or on different zinc-based products resulted in improved barrier properties and reduced runoff rates that seem highly dependent on thickness. The thickest organic coating (150 µm thick), applied on hot dipped galvanized steel, reduced the runoff rate by a factor of 100. No deterioration of organic coatings was observed during the one-year exposures. Alloying zinc-based products with aluminium resulted in surface areas enriched in aluminium and concomitant reduced zinc runoff rates.</p><p>The release rate and bioavailability of copper from different anti-fouling paints into artificial seawater was also investigated. It turned out that the release rate not only depends on the copper concentration in the paint, but also on paint matrix properties and other released metal constituents detected. Far from all copper was bioavailabe at the immediate release situation. In all, the results suggest the importance of assessing the ecotoxic response of anti-fouling paints not only by regarding the copper release, but rather through an integrated effect of all matrix constituents.</p>
48

Responses of marine plankton to pollutant stress : integrated community studies of structure and function

Hjorth, Morten. January 2005 (has links) (PDF)
Ph.d.-afhandling, Roskilde Universitet, 2005. / Haves kun i elektronisk udg. Thesis (Ph.D.). 6 ill., 1tabel; approx. 50 ref. Summaries (Da, En).
49

Análise computacional de metagenomas: evidências de um resistoma marinho

Andrade, Bruno Gabriel Nascimento January 2012 (has links)
Submitted by Priscila Nascimento (pnascimento@icict.fiocruz.br) on 2013-03-22T18:57:42Z No. of bitstreams: 1 Bruno_Gabriel_N_Andrade.pdf: 1653673 bytes, checksum: 187a641b69c50d36212eb943747940e5 (MD5) / Made available in DSpace on 2013-03-22T18:57:42Z (GMT). No. of bitstreams: 1 Bruno_Gabriel_N_Andrade.pdf: 1653673 bytes, checksum: 187a641b69c50d36212eb943747940e5 (MD5) Previous issue date: 2012 / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil. / As Metallo-β-Lactamases (Mβls) são uma família de enzimas cuja importância clínica reside na sua capacidade de hidrolisar praticamente todos os antibióticos da classe dos β-Lactâmicos, incluindo as carbapenemas, que são os compostos mais poderosos utilizados atualmente, a única exceção são os monobactâmicos. Estas enzimas são classificadas em três subclasses, B1, B2 e B3, com base nas suas identidades em nível de sequência e perfil de atividade. As enzimas das subclasses B1 e B3, caracterizam-se por ter amplo espectro de ação enquanto que, as da subclasse B2, são carbapenemases estritas. O conjunto de genes associados à resistência das bactérias aos antimicrobianos, presentes em um determinado ambiente, é conhecido como “Resistoma”. Evidências caracterizam a microbiota de ambientes naturais como fonte e/ou reservatório destes genes e o resistoma ambiental como reservatório original das Mβls. Nosso estudo tem como objetivo buscar em projetos de metagenomas marinhos públicos evidências da existência de um resistoma neste bioma. Buscamos, in silico, por Mβls putativas similares àquelas encontradas em bactérias presentes em ambientes clínicos. Os projetos de metagenomas marinhos públicos foram obtidos no banco de armazenamento do Cyberinfrastructure for Advanced Microbial Research (CAMERA), buscas por Metallo-β-Lactamases foram feitas com o software HMMer V3, empregando um limiar de similaridade baseado em um e-value de 10-20, utilizando os alelos de Metallo-β-Lactamases conhecidos para a construção de perfis HMM, empregados como sondas. Para determinar a relação com as Metallo-β-Lactamases clínicas, uma segunda busca foi feita com os resultados do HMMer contra o banco de dados de proteínas não redundantes (NR) utilizando o programa Blastp do pacote Blast+. Motivos conservados característicos das Mβls foram identificados visualmente para a eliminação de falsos positivos, análises filogenéticas foram feitas utilizando o programa MEGA v5. Identificamos, em sítios de vários oceanos e mares, sequências apresentando Mβls putativas, apresentando similaridade de sequência estatisticamente relevante com Mβls clínicas, como: VIM, CFIA, BLAB, SPM, CPHA, GOB, L1, FEZ1 e CAU-1. Algumas destas Mβls putativas apresentaram identidade de sequência com suas similares clínicas, as Mβls VIM e SPM. Nossa análise mostrou que a Mβl GOB apresenta uma grande abundância e dispersão. Assim, apresentamos as primeiras evidências da existência de um resistoma marinho, caracterizado pela presença de sequências das três subclasses de Mβls e com ampla distribuição pelo meio marinho. / The Metallo-β-lactamases (Mβls) are a family of enzymes with high impact in the clinic due to their ability to hydrolyze virtually all antibiotics belonging to the β-lactams group, excluding the monobactams. These enzymes are classified into three subclasses, B1, B2 and B3, based on their sequence similarity and the activity profile. The enzymes from subclass B1 and B3 present a broad spectrum of activity and the subclass B2 are strict carbapenemases. The set of genes associated with bacteria antimicrobial resistance present in an environment is known as “Resistome”. Studies have presented evidences characterizing the microbiota of natural environments as the source and/or reservoir of resistance genes and the environmental resistome as the original reservoir of Mβls. Our study aims to search publicly available marine metagenome projects for evidences of a marine resistome. We performed an in silico analysis to reveal putative Mβls that are similar to those found in the clinical setting. The marine metagenomic were downloaded from the Cyberinfrastructure for Advanced Microbial Research (CAMERA), and screened for Metallo-β-lactamases with the HMMer V3 software, with similarity threshold of an e-value of 10-20, using the known Metallo-β- lactamases alleles to build HMM profiles, and used them as queries. In order to determine the relationship between these two groups, the results were queried against the NCBI non-redundant protein database using the Blastp software with the same e-value cutoff. The Mβl motifs were visually identified to eliminate false positives, and phylogenetic analysis were made using the MEGA v5 software. Putative sequences showing identity with clinical Mβls, such as: VIM, CFIA, BLAB, SPM, CPHA, GOB, L1, FEZ1 and CAU-1 were found in samples from distinct oceans. Our analysis showed that the Mβl GOB is variable and dispersed in various sites of the oceans. Thus, we could map and bring evidences of the marine resistome based on the presence of the three subclasses of Mβls distributed in the ocean.
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Impactos antropogênicos sobre comunidades de macroalgas marinhas / Anthropogenic impacts on marine macroalgae communities

SCHERNER, Fernando 17 June 2013 (has links)
Submitted by (edna.saturno@ufrpe.br) on 2016-06-17T16:31:52Z No. of bitstreams: 1 Fernando Scherner.pdf: 1240338 bytes, checksum: f5d748da0f0317493176e1e0823d858f (MD5) / Made available in DSpace on 2016-06-17T16:31:52Z (GMT). No. of bitstreams: 1 Fernando Scherner.pdf: 1240338 bytes, checksum: f5d748da0f0317493176e1e0823d858f (MD5) Previous issue date: 2013-06-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Human activities have been causing environmental alterations with consequences to marine biological communities. These changes have been occurring at local scale, such as urbanization and coastal pollution, and globally, throught climate change and ocean acidification caused by higher CO2 concentrations in the atmosphere. Coastal urbanization is rapidly expanding worlwide. This phenomenon has been leading to the contamination of the marine environment by a variety of pollutants, such as heavy metals. However, the effects of coastal urbanization on marine macroalgae communities still need further studies that consider their latitudinal limits of distribution. Likewise, studies on the effects of climate change, such as temperature increases and ocean acidification, on macroalgal communities are recent and still relatively limited. Thus, the aims of the present study were: 1) Evaluate the impacts of urbanization on marine macroalgae communities within different phycogeographycal regions along the Brazilian coast; 2) Assess the physiological effects of heavy metal contamination at concentrations observed in polluted regions within the temperature ranges of distribution of the seaweed Halimeda cuneata Hering in the SW Atlantic; 3) Evaluate the effects of increased temperatures and CO2 driven ocean acidification on the photosynthesis of marine macroalgae. For the first, a significant fraction of the Brazilian coast was studied, including sampling areas on the three phycogeographycal regions (warm temperate, tranzition zone, and tropical) where the structure and composition of the communities were determined in urban and reference areas. For the second, an experiment of metal enrichment was performed in laboratory, assessing the effects of metals at temperatures that occur within the limits of distribution of H. cuneata on the Brazilian coast and its recovery potential at the different temperatures. The third consisted of performing experiments in a reef mesocosms in a tropical region on the Brazilian coast, using calcified macroalgae species, evaluating the effects of temperature increases and CO2 driven acidification on the macroalgae photosynthetic performance. The results are presented here in three chapters. The first shows that urbanization leads to substantial declines in species number and causes drastic changes on marine macroalgae communities. The second provides evidence of the negative effects of heavy metals on the physiology of H. cuneata, which showed no photosynthetic recover at temperatures that occur on its limit of distribution in the south Atlantic. The third indicates a high photosynthetic adaptability of the studied macroalgae in face of temperature increases and acidification, which can be related to the possibilities of utilization of different inorganic carbon species by these algae. / As atividades humanas têm causado alterações ambientais com consequências sobre comunidades biológicas marinhas. Essas alterações vêm ocorrendo em escala local, como é o caso da urbanização e poluição costeira, e global, por meio das mudanças climáticas e acidificação dos oceanos causado por maiores concentrações de CO2 na atmosfera. A urbanização costeira está se expandindo rapidamente no mundo todo. Este fenômeno tem levado à contaminação do ambiente marinho por diversos poluentes, entre eles os metais pesados. Os efeitos da referida urbanização sobre as comunidades de macroalgas ainda necessitam de estudos que considerem os limites de distribuição latitudinal destes organismos. Semelhantemente, estudos sobre os potenciais efeitos das mudanças climáticas, como o aumento da temperatura e acidificação oceânica, sobre comunidades macroalgais, são recentes e ainda relativamente escassos. Nesse contexto, esse estudo teve como objetivos: 1) Avaliar os impactos da urbanização sobre comunidades de macroalgas marinhas nas diferentes províncias ficogeográficas do litoral brasileiro; 2) Compreender os mecanismos fisiológicos da contaminação do ambiente marinho por metais pesados sobre a alga pantropical Halimeda cuneata Hering em temperaturas que ocorrem em seus limites de distribuição no sudoeste do Atlântico; 3) Avaliar os efeitos do aumento de temperatura e da acidificação oceânica por adição de CO2 sobre a fotossíntese de macroalgas marinhas. Para o primeiro, uma fração significativa do litoral brasileiro foi estudada, incluindo áreas amostrais nas três províncias ficogeográficas brasileiras (Temperada quente, Zona de transição e Tropical) onde a estrutura e composição das comunidades foram determinadas em áreas urbanizadas e áreas referências. Para o segundo, um experimento com enriquecimento por metais foi realizado em laboratório, avaliando o efeito de metais em temperaturas que ocorrem dentro dos limites de distribuição de H. cuneata na costa brasileira e o seu potencial de recuperação nas diferentes temperaturas. Com relação ao terceiro, experimentos foram realizados em mesoscosmos recifal em região tropical no litoral brasileiro, utilizando espécies de macroalgas calcificadas, avaliando o efeito de aumentos de temperatura e da acidificação da água por adição de CO2 sobre a performance fotossintética das macroalgas. Os resultados são apresentados aqui em três capítulos. O primeiro mostra que a urbanização leva a diminuições substanciais no número de espécies e causa alterações profundas em comunidades macroalgais marinhas. O segundo evidencia os efeitos deletérios de metais pesados sobre as funções fisiológicas de H. cuneata, com destaque para a ausência de recuperação fotossintética em temperaturas que ocorrem no seu limite de distribuição no Atlântico sul. O terceiro indica uma alta adaptabilidade fotossintética das macroalgas estudadas diante de elevações de temperatura e acidificação, o que pode estar relacionado às possibilidades de utilização de diferentes espécies de carbono inorgânico por estas algas.

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