RESUMO
This review documents technical progress in ophthalmic magnetic resonance imaging (MRI) at ultrahigh fields (UHF, B(0) ≥ 7.0 T). The review surveys frontier applications of UHF-MRI tailored for high spatial resolution in vivo imaging of the eye, orbit and optic nerve. Early examples of clinical ophthalmic UHF-MRI including the assessment of melanoma of the choroid membrane and the characterisation of intraocular masses are demonstrated. A concluding section ventures a glance beyond the horizon and explores research promises along with future directions of ophthalmic UHF-MRI.
Assuntos
Neoplasias Oculares/patologia , Aumento da Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Oftalmoscopia/métodos , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Avaliação da Tecnologia BiomédicaRESUMO
"Push-Pull" is an inexpensive and eminently practical strategy designed for developing countries in order to exploit sound principles of chemical ecology for agricultural pest management. This strategy is specifically suitable for small holder farmers. Their experience can easily be integrated into existing farming practices in their immediate environment. "Push-pull" within one and a half decades became widely established and meanwhile is greatly beneficial to practitioners in East Africa, mainly Kenya. The classical push-pull approach used for applied plant-insect management was pioneered by Khan and Pickett (2000) and subsequent papers of Pickett (2003) and Khan et al. (2006, 2008). Relevant plant species explored so far were maize or sorghum intercropped with other East African plants (Desmodium spp. resp. Melinis minutiflora) possessing natural chemicals repellent resp. attractive for stem borer moths Chilo partellus (Lepidoptera), whereby Desmodium spp. was grown inside the maize rows while M. minutiflora surrounded it. Both simultaneous actions combined resulted in a significant decrease of stem borers in the area to be protected. A benefit to cost ratio of 2.5 was realized. Within a period of 15 years the number of subscribing farmers substantially increased from a few dozen to more than 80,000 in 2014. Two experiments along the paths of chemical ecology were undertaken between Sept 2012 and Feb 2013: One was designed to investigate if the legume D. intortum known to produce repellent volatiles against stem borer moths induces defence in Zea mays varieties. We looked at two open-pollinated farmers' varieties and two commercial hybrid varieties suspecting the farmers' varieties to be responsive rather than the hybrids. However, no defence induction was detected in this study so far. This could be explained by an insufficient production of defence inducing volatiles in leaves of D. intortum whereas flowers might produce a sufficient response. More detailed study is needed. A second approach made use of species-specific insect monitoring traps baited with highly specific female sex pheromones for attracting and monitoring destructive insect pests. The female sex pheromone (8-methyl-decane-2-ol propanoate) of Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae) (Western Corn Rootworm) is readily available as bait in the "Metcalf sticky cup trap" for trapping males, an extraordinarily sensitive technique for monitoring the presence or absence of male beetles in a given area. Li et al. (2006) had argued for the likelihood of easy immigration of this cosmopolitan maize pest into East Africa. Our results, however, so far indicate the absence of a local population in the area of Mbita, while not excluding its presence at Nairobi or Mombasa. Both investigations contribute to different aspects of Kenyan economic development and may be seen as two independent but complementary contributions towards livelihood improvement of small holder farmers in Kenya.
Assuntos
Agricultura/métodos , Controle de Insetos/métodos , Controle Biológico de Vetores/métodos , Doenças das Plantas/prevenção & controle , Zea mays/crescimento & desenvolvimento , Animais , Besouros/efeitos dos fármacos , Besouros/fisiologia , Fabaceae/química , Fabaceae/metabolismo , Feminino , Quênia , Masculino , Mariposas/efeitos dos fármacos , Mariposas/fisiologia , Feromônios/farmacologia , Doenças das Plantas/parasitologia , Compostos Orgânicos Voláteis/metabolismo , Compostos Orgânicos Voláteis/farmacologia , Zea mays/parasitologiaRESUMO
In teleradiology, imaging data are transferred over a distance. This service is provided for the purpose of consulting or teleradiological reading in the narrower sense. Once a justification has been proposed in the latter, the examination is performed under the responsibility of a radiologist who is not present on site. The need for teleradiology services often derives from sparsely populated areas, a shortage of doctors, or the need for cost-efficient provision of radiological examinations. The providers and recipients of teleradiology services enter into an agreement specifying conditions for data transfer. The German ionizing radiation (medical exposure) regulations demand that the teleradiologist holds radiation protection qualifications and is able to reach the examination site within 45 - 60 minutes. In Germany, teleradiology services are still limited to nights, weekends, and vacations, although the German regulations allow an expansion under certain circumstances. Efforts to fundamentally change radiology in favor of teleradiology are putting the status of a radiological medical act as well as current teaching models at risk, thereby indirectly sustaining physician shortage. Transnational teleradiology services offer the possibility of cost reduction, taking advantage of out-of-hour reading and wage fluctuation. At the same time, such services are associated with deficits in quality and availability of personnel as well as the quality of medical services. In the long-term teleradiology concepts will fundamentally change radiology. Smaller radiology units will concentrate on daily business and fast reporting. Larger units also providing academic teaching can use teleradiology networks to offer specialized readings.