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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.
1

Variability in and coupling of larval availability and settlement of the mussel Perna perna : a spatio-temporal approach /

Porri, Francesca. January 2003 (has links)
Thesis (Ph. D. (Zoology & Entomology))--Rhodes University, 2004.
2

Anthropogenic versus natural influences on the genetic structure of the green mussel Perna Viridis (L.) in Hong Kong /

Chan, Kwok-kuen. January 1993 (has links)
Thesis (M. Phil.)--University of Hong Kong, 1993. / Includes bibliographical references (leaves 74-91).
3

Cytological and physiological biomarkers in Perna viridis (Linnaeus) (Bivalvia : Mytilidae) /

Nicholson, Shaun. January 1999 (has links)
Thesis (Ph. D.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves 148-187).
4

Physiological effects of copper, cadmium and reduced salinity on intertidal and cultivated Perna canaliculus mussels : a thesis submitted in fulfilment of the requirements for the degree of Masters [i.e. Master] of Science in Zoology at the University of Canterbury, New Zealand /

Smith, Frantz E. January 2008 (has links)
Thesis (M. Sc.)--University of Canterbury, 2008. / Typescript (photocopy). Includes bibliographical references (leaves 209-228). Also available via the World Wide Web.
5

Variability in and coupling of larval availability and settlement of the mussel Perna perna : a spatio-temporal approach

Porri, Francesca January 2004 (has links)
Population dynamics of many intertidal organisms are highly influenced by the abundance and distribution of planktonic larvae in the water column and their arrival on the shore. The brown mussel, Perna perna was used to investigate two of the primary processes that affect population size and dynamics, larval availability and settlement, on the south coast of South Africa. Perna perna is a dominant species on rocky shores of the southern and eastern coasts of South Africa. It creates three-dimensional beds that provide habitats for many other species and hence promotes biodiversity. Larval availability and settlement were examined at different spatial and temporal scales using a nested experimental design. To detect possible relationships between larval availability and settlement, the studies were simultaneous. Two sites, 4km apart, were chosen to investigate mussel settlement patterns. Within each site, three locations (300m from each other) were selected. At each location, five artificial settler collectors were placed at approximately 20cm intervals. Collectors were replaced at a range of time intervals, from daily to seasonal, for 16 months. Each intertidal location was paired with an offshore station, 500m from the shore, where larval availability was measured. At each offshore station, three vertical hauls were collected twice a month using a plankton net. Plankton sampling lasted for 14 months and was designed to examine variability on three temporal scales: seasonal, lunar and daily. The results showed no correlation between the distribution of larvae in the water and settlers on the shore. While larvae were abundant in the water at the start of sampling, they became very rare throughout the rest of the study at both sites and all locations. In contrast, distinct peaks of settler abundance were observed during the seasonal settlement study. In addition to the expected, strong temporal variation that emerged from both studies at all time scales, spatial patterns of variability were also observed. While no spatial effect was detected for the larvae in the water column, there was distinct spatial variation in settlement at the location level: some locations always showed higher settlement than others. These results suggest that, on scales of hundreds of meters to kilometers, larval availability and settlement are very unpredictable in time and that differential delivery of larvae occurs from nearshore waters to the shore. Although the effect of the state of the moon (new or full) was not significant in either study, more settlers seemed to arrive on the shore during new moon. Wind direction did not correlate significantly with settlement. However, the dropping of offshore winds and the prevalence of onshore winds, which are characteristic of summer, may be linked to the start of settlement. Nevertheless, further investigations on tidal or lunar cycles and on the influence of wind on surface currents are required to clarify the effects of moon and wind on settlement.
6

The effect of chronic copper exposure on the energy budget of two mussels, perna viridis (L.) and septifer virgatus (Wiegmann) /

Sze, Wai-chung. January 1995 (has links)
Thesis (M. Phil.)--University of Hong Kong, 1996. / Includes bibliographical references (leaf 170-195).
7

Biomarcadores de exposição, efeito e bioacumulação de xenobióticos em mexilhões Perna perna (Linnaeus, 1758) transplantados ao longo do litoral de São Paulo / Biomarkers of exposure, effect and bioaccumulation of xenobiotics in mussels Perna perna transplanted along São Paulo shore

Pereira, Camilo Dias Seabra 20 May 2008 (has links)
O presente estudo avaliou a exposição, os efeitos e a bioacumulação de xenobióticos em mexilhões Perna perna coletados na Praia da Cocanha (Caraguatatuba - referência) e transplantados para: Engenho d\'Água (Ilhabela), Terminal Almirante Barroso - TEBAR (São Sebastião), Ilha das Palmas e Itaipu (Baía de Santos). Após 3 meses de exposição em cada estação do ano, os mexilhões foram analisados quanto à bioacumulação de metais, HPAs, LABs e a biomarcadores de exposição e efeito. Os organismos fixados na Ilhabela apresentaram concentrações mais elevadas de Cd, Hg, alterações significativas nas atividades de Glutationa Peroxidase (GPx) e Glutationa-S-Transferase (GST), no tempo de retenção do vermelho neutro (TRVN) e no desenvolvimento embriolarval (DE); no TEBAR apresentaram bioacumulação de HPAs, Fe, Co, Cd, alteração na atividade de CYP 450 (DBF), nos danos em DNA, lipoperoxidação e no TRVN; na Ilha das Palmas apresentaram bioacumulação de Co, Fe, Cr, Hg, Pb, LABs e alterações nas atividades de DBF, Catalase, GPx, Glutationa Redutase (GR), TRVN e DE; enquanto que os organismos transplantados para Itaipu acumularam Fe, Co, Cd, Hg, Pb e apresentaram alterações nas atividades de DBF, GPX, GR, GST, danos em DNA, TRVN e DE. A integração dos resultados de biomarcadores e bioacumulação propiciou um melhor entendimento da biodisponibilidade e dos efeitos de contaminantes para a espécie estudada no litoral de São Paulo. / The present study aimed to assess the exposure, effects and bioaccumulation ofxenobiotics in the mussel Perna perna transplanted from a clean site (Cocanha Beach, Caraguatatuba) to different sites (Engenho D\'Água Beach - Ilhabela; TEBAR oil terminal - São Sebastião; Palmas Island and Itaipu - Santos Bay). In each season, after 3 months of exposure, the mussels were recollected and their tissues were evaluated for bioaccumulation of metals, PAHs, LABs and biomarkers of exposure and effect. Organisms transplanted to Ilhabela accumulated Cd, Hg and exhibited significant alterations on Glutathione Peroxidase (GPx), Glutathione -S-Transferase (GST), Neutral Red retention time (NRRT) and embryonic development (ED); organisms transplanted to TEBAR accumulated PAHs, Fe, Co, Cd and showed significant differences on CYP 450 (DBF), DNA damage, lipidic peroxidation, NRRT and ED; organisms transplanted to Palmas accumulated Co, Fe, Cr, Hg, Pb, LABs and showed alterations on DBF, Catalase, GPx, Glutathione Reductase (GR), NRRT and ED; whereas organisms transplanted to Itaipu accumulated Fe, Co, Cd, Hg, Pb and exhibited alterations on DBF, GPX, GR and GST activities, DNA damages, NRRT and ED. This integrated assessment of biomarkers and bioaccumulation provided a better comprehension on the bioavailability and effects of contaminants for the studied species in São Paulo shore.
8

Avaliação da citotoxicidade do Dietiltoluamida (DEET) em mexilhões Perna perna (Linnaeus, 1758) irradiados e não irradiados com radiação gama de 60Co / Cytotoxicity evaluation of Diethyltoluamide (DEET) in Perna perna (Linnaeus, 1758) mussels non-irradiated and irradiated with 60Co gamma radiation

Martini, Gisela de Assis 18 October 2013 (has links)
Estudos recentes têm identificado a presença de diversos poluentes emergentes em ambientes aquáticos. A ocorrência em diferentes matrizes ambientais tem sido continuamente relatada, o que evidencia a necessidade de estudos de toxicidade. O DEET (N,N-dietil-meta-toluamida) é o princípio ativo mais utilizado em repelentes de insetos e está presente em diversas formulações comercialmente disponíveis. Além dos poluentes químicos, os organismos aquáticos estão sujeitos à exposição da radiação ionizante proveniente de fontes naturais ou em proximidades de instalações de usinas nucleares. O presente estudo avaliou a toxicidade do DEET em organismos irradiados e não irradiados com radiação gama de 60Co, e os efeitos que a radiação causa sob os lisossomos de hemócitos do mexilhão Perna perna. Para isso, foram realizados ensaios de toxicidade aguda para identificar a concentração de DEET e a dose de radiação gama passíveis de causar mortalidade, e posteriormente ensaios de citotoxicidade avaliando a estabilidade da membrana lisossômica em organismos expostos ao DEET e radiação ionizante. De acordo com os resultados obtidos nos ensaios de toxicidade aguda, a concentração de DEET que causa mortalidade em 50% dos organismos expostos (CL50) é de 114,27 mg L-1, e a dose de radiação que causa mortalidade (DL50) é de 1068 Gy. Nos os ensaios de citotoxicidade obteve-se a concentração de efeito não observado (CENO) para organismos irradiados e não irradiados de 0,0001 mg L-1 e a concentração de efeito observado (CEO) em concentrações acima desta. A CI25(72h) para organismos não irradiados foi de 0,0003 mg L-1 e a CI50(72h) foi de 0,0008 mg L-1 para organismos irradiados e não irradiados. Apesar das concentrações de efeito encontradas no presente estudo terem sido mais altas que as ambientais, estão na mesma ordem de grandeza e também deve-se levar em consideração os possíveis efeitos sinérgicos do DEET com outros contaminantes presentes em ambiente aquático. / Recent studies have identified the presence of several emerging pollutants in aquatic environments. The occurrence in different environmental matrices has been continuously reported, highlighting the need for toxicity studies. The DEET (N,N-diethyl-meta-toluamide) is the active ingredient used in most insect repellents, and is present in many commercially available formulations. Apart from chemical pollutants, aquatic organisms are subject to exposure of ionizing radiation from natural sources or in the vicinity of nuclear power plants. The present study evaluated the toxicity of DEET in organisms irradiated and non-irradiated with 60Co gamma radiation, and the effects that radiation causes in lysosomes of hemocytes of Perna perna mussel. For this purpose, assays were performed to identify the acute toxicity of DEET concentration and the dose of gamma radiation able to cause mortality. Subsequently, cytotoxicity assays were carried out to assess the stability of the lysosomal membrane in organisms exposed to ionizing radiation and DEET. According to the results obtained in acute toxicity tests, the concentration of DEET that causes mortality of 50% exposed organisms (LC50) is 114,27 mg L-1, and the radiation dose that causes mortality (LD50) is 1068 Gy. In the cytotoxicity assays, the concentration of the non-observed effect (NOEC) for irradiated and non-irradiated organisms 0.0001 mg L-1 and observed effect concentration (LOEC) at concentrations above this. The IC25 (72h) for non-irradiated organisms was 0.0003 mg L-1 and IC50 (72h) was 0.0008 mg L-1 for irradiated and non-irradiated organisms. Despite of the concentrations of effect found in this study were higher than in the environment, both measurements are in the same order of magnitude and should be also take into account the possible synergistic effects of DEET with other contaminants in the aquatic environment.
9

Concepção de uma tecnologia de monitoramento e gerenciamento do cuidado de pessoas com úlcera venosa / Concepção de uma Tecnologia de Monitoramento e Gerenciamento do Cuidado de Pessoas com úlcera Venesa (Inglês)

Prado, Silveria Lopes Ponte 15 December 2017 (has links)
Made available in DSpace on 2019-03-30T00:28:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-12-15 / Chronic Leg Ulcers (UCP) has been a common health problem in the population, with negative impact on quality of life due to difficult healing and relapses. UCPs may be of different etiologies, such as those of venous involvement, arterial, neuropathic, hematological and dermatological. However, the main one is peripheral vascular disease, with a focus on venous insufficiency. Fragility was verified in the monitoring process of the patient with UCP, and these fragilities have a direct impact on the proper cicatrization and their recurrence. The objective was to design an interventionist technological artifact as a strategy for the monitoring and management of patients with UV in the cicatricial process. This is a methodological research with predominantly quantitative approach, developed in four stages: 1st bibliographical survey of the needs and knowledge about specialized care for people with chronic leg ulcers 2nd laboratory phase of design and development of the technological artifact; 3rd evaluation of the artifact by judges and; 4th compilation and analysis of results. The research was approved by the Research Ethics Committee of the University of Fortaleza - UNIFOR (opinion nº2.300.822 and opinion nº1.865.393). The judges were selected on social networks and contacted by e-mail both for acceptance of participation and for evaluation of the content of the software via Google form <docs.google.Com>. The percentage of agreement and the index of validity of content (IVC) greater than 0.78. The prototype design of the software had its content validated by experts who approved 87 items from the 101 proposals. As for the form, a percentage of 100% of the positive answers of the specialists was obtained, showing an applicable instrument. Regarding the usability test, it was demonstrated that the tool is simple to handle, easy to identify and its texts are legible. In addition, their menus and icons are arranged in a way that facilitates access and information. It is concluded that there are several factors involved in care for people with UV (linked to ulcer, constitutional, behavioral, linked to malpractice and institutional). Compressive therapy requires an interventionist approach to the care and adherence of people with UV. The software will monitor and manage the factors to guide the healing process. It has been validated in its content and form by the stoma therapists. / As Úlceras Crônicas de Pernas (UCP) vem sendo um problema de saúde comum na população, com gerando impacto negativo na qualidade de vida devido a difícil cicatrização e recidivas. As UCPs podem ser de diferentes etiologias, como as de comprometimento venosa, arteriais, neuropáticas, hematológicas e dermatológicas. Porém a principal delas é a doença vascular periférica, com foco na insuficiência venosa. Verificou-se fragilidade no processo de monitoramento do paciente com UCP, e essas fragilidades impactam diretamente na cicatrização adequada e na reincidência das mesmas. Face ao exposto o objetivo foi conceber um artefato tecnológico intervencionista como estratégia para o monitoramento e gerenciamento dos pacientes com UV no processo cicatricial. Trata-se de pesquisa metodológica com abordagem predominantemente quantitativa, desenvolvida em quatro etapas: 1ª levantamento bibliográfico das necessidades e conhecimentos sobre o cuidado especializado às pessoas com úlceras crônicas de pernas 2ª fase laboratorial de concepção e desenvolvimento do artefato tecnológico; 3ª avaliação do artefato por juizes e; 4ª compilação e análise dos resultados. A pesquisa foi aprovada pelo Comitê de Ética em Pesquisa da Universidade de Fortaleza - UNIFOR (parecer nº 2.300.822 e parecer nº 1.865.393). Os juízes foram selecionados nas redes sociais e contactados por e-mail tanto para aceitação da participação como para a avaliação do conteúdo do software via Google formulário <docs.google.com>. Utilizou-se a percentagem de concordância e o índice de validade de conteúdo (IVC) maior a 0,78. A concepção do protótipo do software teve seu conteúdo validado por especialistas que aprovaram 87 itens dos 101 propostos. Quanto à forma, obtevese um percentual de 100% das respostas positivas dos especialistas, mostrando-se um instrumento aplicável. Em relação ao teste de usabilidade, demonstrou-se que a ferramenta é de simples manuseio, de fácil identificação e seus textos são legíveis. Além disso, os seus menus e ícones estão dispostos de forma que facilita o acesso e a informação. Conclui-se que são vários fatores intervenientes no cuidado as pessoas com UV (ligados á úlcera, constitucionais, comportamentais, ligados às más práticas e institucionais). A terapia compressiva requer uma abordagem intervencionista do cuidado e adesão das pessoas com UV. O software fará a monitorização e gerenciamento dos fatores para nortear o processo cicatricial. Foi validado no seu conteúdo e forma pelos estomaterapeutas.
10

Biomarcadores de exposição, efeito e bioacumulação de xenobióticos em mexilhões Perna perna (Linnaeus, 1758) transplantados ao longo do litoral de São Paulo / Biomarkers of exposure, effect and bioaccumulation of xenobiotics in mussels Perna perna transplanted along São Paulo shore

Camilo Dias Seabra Pereira 20 May 2008 (has links)
O presente estudo avaliou a exposição, os efeitos e a bioacumulação de xenobióticos em mexilhões Perna perna coletados na Praia da Cocanha (Caraguatatuba - referência) e transplantados para: Engenho d\'Água (Ilhabela), Terminal Almirante Barroso - TEBAR (São Sebastião), Ilha das Palmas e Itaipu (Baía de Santos). Após 3 meses de exposição em cada estação do ano, os mexilhões foram analisados quanto à bioacumulação de metais, HPAs, LABs e a biomarcadores de exposição e efeito. Os organismos fixados na Ilhabela apresentaram concentrações mais elevadas de Cd, Hg, alterações significativas nas atividades de Glutationa Peroxidase (GPx) e Glutationa-S-Transferase (GST), no tempo de retenção do vermelho neutro (TRVN) e no desenvolvimento embriolarval (DE); no TEBAR apresentaram bioacumulação de HPAs, Fe, Co, Cd, alteração na atividade de CYP 450 (DBF), nos danos em DNA, lipoperoxidação e no TRVN; na Ilha das Palmas apresentaram bioacumulação de Co, Fe, Cr, Hg, Pb, LABs e alterações nas atividades de DBF, Catalase, GPx, Glutationa Redutase (GR), TRVN e DE; enquanto que os organismos transplantados para Itaipu acumularam Fe, Co, Cd, Hg, Pb e apresentaram alterações nas atividades de DBF, GPX, GR, GST, danos em DNA, TRVN e DE. A integração dos resultados de biomarcadores e bioacumulação propiciou um melhor entendimento da biodisponibilidade e dos efeitos de contaminantes para a espécie estudada no litoral de São Paulo. / The present study aimed to assess the exposure, effects and bioaccumulation ofxenobiotics in the mussel Perna perna transplanted from a clean site (Cocanha Beach, Caraguatatuba) to different sites (Engenho D\'Água Beach - Ilhabela; TEBAR oil terminal - São Sebastião; Palmas Island and Itaipu - Santos Bay). In each season, after 3 months of exposure, the mussels were recollected and their tissues were evaluated for bioaccumulation of metals, PAHs, LABs and biomarkers of exposure and effect. Organisms transplanted to Ilhabela accumulated Cd, Hg and exhibited significant alterations on Glutathione Peroxidase (GPx), Glutathione -S-Transferase (GST), Neutral Red retention time (NRRT) and embryonic development (ED); organisms transplanted to TEBAR accumulated PAHs, Fe, Co, Cd and showed significant differences on CYP 450 (DBF), DNA damage, lipidic peroxidation, NRRT and ED; organisms transplanted to Palmas accumulated Co, Fe, Cr, Hg, Pb, LABs and showed alterations on DBF, Catalase, GPx, Glutathione Reductase (GR), NRRT and ED; whereas organisms transplanted to Itaipu accumulated Fe, Co, Cd, Hg, Pb and exhibited alterations on DBF, GPX, GR and GST activities, DNA damages, NRRT and ED. This integrated assessment of biomarkers and bioaccumulation provided a better comprehension on the bioavailability and effects of contaminants for the studied species in São Paulo shore.

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