Scanning electron microscopy of third-instar sarcophagid (Diptera: Sarcophagidae) recovered from a mummified human corpse in Thailand

The third-instar of an unidentified sarcophagid, recovered from a mummified body of a 32-yr-old Thai male was examined using scanning electron microscopy (SEM). Although the morphological features of this larva are similar to the other sarcophagid larvae, some features could be helpful for species identification, which is a basic requirement for estimation of postmortem interval in forensic investigation. These features included number and arrangement of papillae on the anterior spiracle, structure of spines, size of circumspiracular tubercles at caudal segment and branching peculiarity of the posterior spiracular hairs. This information could benefit future identification of the sarcophagid larvae that exist in Thailand.

Contributos para uma História do Ir à praia em Portugal

Dissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de Mestre em História Contemporânea

PREHISTORICAL Pediculus humanus capitis INFESTATION: QUANTITATIVE DATA AND LOW VACUUM SCANNING MICROSCOPY

A pre-Columbian Peruvian scalp was examined decades ago by a researcher from the Oswaldo Cruz Foundation. Professor Olympio da Fonseca Filho described nits and adult lice attached to hair shafts and commented about the origin of head lice infestations on mankind. This same scalp was sent to our laboratory and is the subject of the present paper. Analysis showed a massive infestation with nine eggs/cm2 and an impressive number of very well preserved adult lice. The infestation age was roughly estimated as nine months before death based on the distance of nits from the hair root and the medium rate of hair growth. A small traditional textile was associated with the scalp, possibly part of the funerary belongings. Other morphological aspects visualized by low-vacuum scanning electron microscopy are also presented here for adults and nits.

Automated segmentation, tracking and evaluation of bacteria in microscopy images

Dissertação para obtenção do Grau de Mestre em Engenharia Biomédica

Scanning electron microscopy and X-ray spectroscopy applied to mycelial phase of sporothrix schenckii

Scanning electron microscopy applied to the mycelial phase of Sporothrix schenckii shows a matted mycelium with conidia of a regular pattern. X-Ray microanalysis applied in energy dispersive spectroscopy and also in wavelength dispersive spectroscopy reveals the presence of several elements of Mendeleef's classification.

Study of chelicerae in the tick Amblyomma cajennense (Fabricius 1787) by scanning electron microscopy

Chelicerae de Amblyomma cajennense foram examinados em microscopia de varredura. Esta técnica mostrou detalhes não evidenciáveis ao poder de resolução do microscópio ótico.

Atomic force microscopy assisted with electron and ion beam microscopy for the direct measurement of biostructures and DNA samples

Dissertation to obtain a Master degree in Biotechnology

Confocal fluorescence microscopy: a powerful tool in the study of Chagas' disease

Confocal scanning fluorescence microscopy has become widely used in cell biology and pathology. In conjunction with monoclonal antibodies it may turn out to be a powerful diagnostic tool that also enables detailed studies of tissue forms of Trypanosoma cruzi.

Profissionais de saúde da Guiné-Bissau em Portugal por detrás do ir e não voltar

Introdução: A migração, apesar de não ser um fenómeno recente entre as profissões de saúde assumiu nos últimos anos proporções significativas, sobretudo em África. Para a GB, a saída dos profissionais de saúde tem um impacto devastador no que concerne o desempenho do sistema de saúde e por conseguinte a saúde das populações. Portugal, pelas ligações histórias e pela proximidade que mantém com a GB, tem sido escolhido pelos profissionais de saúde como o país destino para a emigração. Neste sentido considerou-se importante aprofundar conhecimentos sobre o fenómeno migratório dos profissionais de saúde da GB para Portugal, incluindo as motivações dos profissionais de saúde, a realidade vivida em Portugal e os motivos para o regresso. Objectivos: Caracterizar o fenómeno migratório dos profissionais de saúde guineenses para Portugal, ao longo de todo o processo migratório, desde a decisão de emigrar, à decisão de retorno. Material e métodos: Este estudo teve por base uma abordagem qualitativa, optando-se pela realização de um estudo de caso único, com várias unidades de análise. O caso em estudo foi o fenómeno migratório, tendo como objecto de estudo os profissionais de saúde guineenses nele envolvidos. Utilizaram-se métodos não probabilísticos para a selecção das amostras. Foram realizadas um total de 4 entrevistas semi-estruturadas a profissionais de saúde, 3 grupos focais a enfermeiros e 3 entrevistas a informadores chave na GB. Em Portugal, foram realizadas 12 entrevistas semi-estruturadas. Posteriormente, realizou-se a análise de conteúdo e análise exploratória dos dados. Resultados: As condições de trabalho, o acesso a formação, o crescimento e valorização profissionais, assim como, a estabilidade político-militar e melhores condições de vida, são factores essenciais para a motivação e empenho dos profissionais de saúde, e por conseguinte, funcionam como factores impulsionadores da emigração quando não existentes. Enquanto imigrantes, os profissionais médicos e enfermeiros não têm o mesmo percurso em termos de integração profissional. Os enfermeiros recentemente emigrados não obtêm o reconhecimento das suas habilitações ao contrário dos médicos. Contudo, a melhoria das condições de vida é, na generalidade, alcançada. Existe na maioria dos profissionais o desejo de regressar ao país de origem, estando a sua concretização dependente de condições tanto na GB como em Portugal. Conclusão: O fenómeno migratório é algo complexo, com inúmeros factores e em constante evolução, dizendo respeito sobretudo à procura de melhores condições de trabalho e de vida. O presente estudo serviu para identificar alguns destes factores e caracterizar as etapas do processo migratório dos profissionais de saúde da GB para Portugal, desde a decisão de emigrar à decisão de regressar. Deixa também pistas para desafios que se impõem com a migração destes profissionais.

Microscopy image segmentation by active contour models

In this thesis a semi-automated cell analysis system is described through image processing. To achieve this, an image processing algorithm was studied in order to segment cells in a semi-automatic way. The main goal of this analysis is to increase the performance of cell image segmentation process, without affecting the results in a significant way. Even though, a totally manual system has the ability of producing the best results, it has the disadvantage of taking too long and being repetitive, when a large number of images need to be processed. An active contour algorithm was tested in a sequence of images taken by a microscope. This algorithm, more commonly known as snakes, allowed the user to define an initial region in which the cell was incorporated. Then, the algorithm would run several times, making the initial region contours to converge to the cell boundaries. With the final contour, it was possible to extract region properties and produce statistical data. This data allowed to say that this algorithm produces similar results to a purely manual system but at a faster rate. On the other hand, it is slower than a purely automatic way but it allows the user to adjust the contour, making it more versatile and tolerant to image variations.

Laboratory diagnosis of amebiasis in a sample of students from southeastern Brazil and a comparison of microscopy with enzyme-linked immunosorbent assay for screening of infections with Entamoeba sp.

Introduction: Epidemiological studies on amebiasis have been reassessed since Entamoeba histolytica and E. dispar were first recognized as distinct species. Because the morphological similarity of these species renders microscopic diagnosis unreliable, additional tools are required to discriminate between Entamoeba species. The objectives of our study were to compare microscopy with ELISA kit (IVD®) results, to diagnose E. histolytica infection, and to determine the prevalence of amebiasis in a sample of students from southeastern Brazil. Methods: In this study, diagnosis was based on microscopy due to its capacity for revealing potential cysts/trophozoites and on two commercial kits for antigen detection in stool samples. Results: For 1,403 samples collected from students aged 6 to 14 years who were living in Divinópolis, Minas Gerais, Brazil, microscopy underestimated the number of individuals infected with E. histolytica/E. dispar (5.7% prevalence) compared with the ELISA kit (IVD®)-based diagnoses (15.7% for E. histolytica/E. dispar). A comparison of the ELISA (IVD®) and light microscopy results returned a 20% sensitivity, 97% specificity, low positive predictive value, and high negative predictive value for microscopy. An ELISA kit (TechLab®) that was specific for E. histolytica detected a 3.1% (43/1403) prevalence for E. histolytica infection. Conclusions: The ELISA kit (IVD®) can be used as an alternative screening tool. The high prevalence of E. histolytica infection detected in this study warrants the implementation of actions directed toward health promotion and preventive measures.