28 research outputs found
DNA barcoding reveals the coral “laboratory-rat”, Stylophora pistillata encompasses multiple identities
Stylophora pistillata is a widely used coral “lab-rat” species with highly variable morphology and a broad biogeographic range (Red Sea to western central Pacific). Here we show, by analysing Cytochorme Oxidase I sequences, from 241 samples across this range, that this taxon in fact comprises four deeply divergent clades corresponding to the Pacific-Western Australia, Chagos-Madagascar-South Africa, Gulf of Aden-Zanzibar-Madagascar, and Red Sea-Persian/Arabian Gulf-Kenya. On the basis of the fossil record of Stylophora, these four clades diverged from one another 51.5-29.6 Mya, i.e., long before the closure of the Tethyan connection between the tropical Indo-West Pacific and Atlantic in the early Miocene (16–24 Mya) and should be recognised as four distinct species. These findings have implications for comparative ecological and/or physiological studies carried out using Stylophora pistillata as a model species, and highlight the fact that phenotypic plasticity, thought to be common in scleractinian corals, can mask significant genetic variation
Overlay of conventional angiographic and en-face OCT images enhances their interpretation
BACKGROUND: Combining characteristic morphological and functional information in one image increases pathophysiologic understanding as well as diagnostic accuracy in most clinical settings. En-face optical coherence tomography (OCT) provides a high resolution, transversal OCT image of the macular area combined with a confocal image of the same area (OCT C-scans). Creating an overlay image of a conventional angiographic image onto an OCT image, using the confocal part to facilitate transformation, combines structural and functional information of the retinal area of interest. This paper describes the construction of such overlay images and their aid in improving the interpretation of OCT C-scans. METHODS: In various patients, en-face OCT C-scans (made with a prototype OCT-Ophthalmoscope (OTI, Canada) in use at the Department of Ophthalmology (Academic Medical Centre, Amsterdam, The Netherlands)) and conventional fluorescein angiography (FA) were performed. ImagePro, with a custom made plug-in, was used to make an overlay-image. The confocal part of the OCT C-scan was used to spatially transform the FA image onto the OCT C-scan, using the vascular arcades as a reference. To facilitate visualization the transformed angiographic image and the OCT C-scan were combined in an RGB image. RESULTS: The confocal part of the OCT C-scan could easily be fused with angiographic images. Overlay showed a direct correspondence between retinal thickening and FA leakage in Birdshot retinochoroiditis, localized the subretinal neovascular membrane and correlated anatomic and vascular leakage features in myopia, and showed the extent of retinal and pigment epithelial detachment in retinal angiomatous proliferation as FA leakage was subject to blocked fluorescence. The overlay mode provided additional insight not readily available in either mode alone. CONCLUSION: Combining conventional angiographic images and en-face OCT C-scans assists in the interpretation of both imaging modalities. By combining the physiopathological information in the angiograms with the structural information in the OCT scan, zones of leakage can be correlated to structural changes in the retina or pigment epithelium. This strategy could be used in the evaluation and monitoring of patients with complex central macular pathology
Virtual Reality as a Tool for Evaluation of Repetitive Rhythmic Movements in the Elderly and Parkinson's Disease Patients
This work presents an immersive Virtual Reality (VR) system to evaluate, and potentially treat, the alterations in rhythmic hand movements seen in Parkinson's disease (PD) and the elderly (EC), by comparison with healthy young controls (YC). The system integrates the subjects into a VR environment by means of a Head Mounted Display, such that subjects perceive themselves in a virtual world consisting of a table within a room. In this experiment, subjects are presented in 1st person perspective, so that the avatar reproduces finger tapping movements performed by the subjects. The task, known as the finger tapping test (FT), was performed by all three subject groups, PD, EC and YC. FT was carried out by each subject on two different days (sessions), one week apart. In each FT session all subjects performed FT in the real world (FTREAL) and in the VR (FTVR); each mode was repeated three times in randomized order. During FT both the tapping frequency and the coefficient of variation of inter-tap interval were registered. FTVR was a valid test to detect differences in rhythm formation between the three groups. Intra-class correlation coefficients (ICC) and mean difference between days for FTVR (for each group) showed reliable results. Finally, the analysis of ICC and mean difference between FTVR vs FTREAL, for each variable and group, also showed high reliability. This shows that FT evaluation in VR environments is valid as real world alternative, as VR evaluation did not distort movement execution and detects alteration in rhythm formation. These results support the use of VR as a promising tool to study alterations and the control of movement in different subject groups in unusual environments, such as during fMRI or other imaging studies
Efeito da radioterapia na função pulmonar e na fadiga de mulheres em tratamento para o câncer de mama
O presente estudo comparou a função pulmonar e a fadiga de mulheres antes e após a radioterapia (RT) adjuvante para tratamento do câncer de mama, e correlacionou a função pulmonar com a dose de radiação e fadiga. Foi conduzido um estudo observacional longitudinal envolvendo 20 mulheres. A função pulmonar foi avaliada pela espirometria (ClementClarke®) e manovacuometria (GlobalMed®, modelo MVD 300), e a fadiga pelo Functional Assessment of Cancer Therapy Fatigue (FACT-F). Todas as avaliações foram realizadas antes da primeira sessão e uma semana após o término da RT adjuvante. Para a análise estatística foram utilizados os testes Wilcoxon Signed Rank Test e correlação de Spearman, adotando-se nível de significância p<0,05. Na espirometria, encontrou-se redução significativa da capacidade vital forçada (23,52%), do volume expiratório forçado no primeiro segundo (26,23%) e do pico de fluxo expiratório (10,12%) (p=0,001). As pressões expiratórias e inspiratórias máximas também diminuíram significativamente (25,45 e 32,92%, respectivamente). Observou-se diminuição significativa do bem-estar físico e do bem-estar funcional, e um aumento significativo da fadiga no FACT-F (p=0,001). Não foram observadas correlações entre as variáveis da função pulmonar com a dose de radiação e fadiga. Em curto prazo, a RT promoveu redução na função pulmonar, mas a mesma permaneceu próxima à normalidade para a amostra estudada. Observou-se aumento significativo da fadiga e diminuição dos escores dos domínios bem-estar físico e funcional
