125 research outputs found
Methods for multi-spectral image fusion: identifying stable and repeatable information across the visible and infrared spectra
Fusion of images captured from different viewpoints is a well-known challenge in computer vision with many established approaches and applications; however, if the observations are captured by sensors also separated by wavelength, this challenge is compounded significantly. This dissertation presents an investigation into the fusion of visible and thermal image information from two front-facing sensors mounted side-by-side. The primary focus of this work is the development of methods that enable us to map and overlay multi-spectral information; the goal is to establish a combined image in which each pixel contains both colour and thermal information. Pixel-level fusion of these distinct modalities is approached using computational stereo methods; the focus is on the viewpoint alignment and correspondence search/matching stages of processing. Frequency domain analysis is performed using a method called phase congruency. An extensive investigation of this method is carried out with two major objectives: to identify predictable relationships between the elements extracted from each modality, and to establish a stable representation of the common information captured by both sensors. Phase congruency is shown to be a stable edge detector and repeatable spatial similarity measure for multi-spectral information; this result forms the basis for the methods developed in the subsequent chapters of this work. The feasibility of automatic alignment with sparse feature-correspondence methods is investigated. It is found that conventional methods fail to match inter-spectrum correspondences, motivating the development of an edge orientation histogram (EOH) descriptor which incorporates elements of the phase congruency process. A cost function, which incorporates the outputs of the phase congruency process and the mutual information similarity measure, is developed for computational stereo correspondence matching. An evaluation of the proposed cost function shows it to be an effective similarity measure for multi-spectral information
The association between placental human papillomavirus detection and pre-eclampsia in adult women giving birth in two academic hospitals in Johannesburg
A research report submitted to the Faculty of Health Sciences, University of the
Witwatersrand in partial fulfilment of the requirements for the degree of
Master of Medicine in the branch of Obstetrics & Gynaecology. Johannesburg, 2017.Background and objectives
Evidence supporting an association between HPV infection and pre-eclampsia has
recently been published. Pre-eclampsia is a common, serious complication of
pregnancy of complex aetiology that to date has not been fully described. Human
papillomavirus (HPV) is a ubiquitous, DNA-virus with tropism for human mucosal
commonly found in the female genital tract. Association between placental HPV
infection and preterm labour and pregnancy loss has previously been described. This
study tested the hypothesis that an association exists between HPV in the placenta
or the cervix and clinical pre-eclampsia, or levels of its associated biomarkers,
soluble fms-like tyrosine kinase (sFLT1) and placental growth factor (PlGF).
Methods
Women with pre-eclampsia were matched to healthy controls. All subjects were
delivered by caesarean section, and cervical and placental samples were collected at
the time of delivery. These samples were tested for HPV using a polymerase chain
reaction (PCR) assay. Serum levels of soluble fms-like tyrosine kinase (sFLT1) and
placental growth factor (PlGF) at the time of delivery were tested. Placental and
cervical HPV was compared to the outcomes of clinical pre-eclampsia and serum
sFLT1 and PlGF levels.
Results and conclusion
While clinically apparent disease was associated with increased levels of sFLT1 and
decreased levels of PlGF, HPV was not detected in any of the placental specimens
using the PCR assay. As a result, no association was found between placental HPV
detection and clinically apparent pre-eclampsia or deranged serum levels of sFLT1 or
PlGF. HPV was very common in cervical samples and showed a non-significant trend
towards negative association with clinical pre-eclampsia and sFLT1, and a positive
association with PlGF. This may be an effect of cervical HPV infection on the
vascular endothelial growth factor (VEGF) signalling system that may explain its
association with miscarriage.LG201
Local government development priorities in developing regions: Implications for environmental management - case studies in the Free State Province, South Africa
Development at Local Government level in South Africa is guided by the formulation of Land Development Objectives (LDOs) which referred to the strategic planning phase of the Integrated Development Planning (IDP) process. Legislation determines that each Local Authority should identify and prioritise the most important developmental issues to ensure that the limited resources available are focussed on those aspects that are of the greatest concern to the community at large. Since the LDO process implies a legislative requirement with legally binding outcomes, it is significant to identify the development principles targeted; the aspects reflected in the long-term visions of the towns, and the development issues that received priority. The outcome of the latter will have direct implications for the focus of environmental management. This article will provide a short overview of the LDO process after which four case studies, representing a range of economic and demographic profiles, will be analysed. The most relevant and pressing local government development issues, identified by the specific communities within the context of a broad understanding of the term environment, will subsequently be highlighted. This will provide a context to realistically implement responsible environmental management practice
Did Adolf Hitler have syphilis?
The evidence that Adolf Hitler may have suffered from incapacitating syphilis is reviewed. Rumours that he acquired syphilis from a prostitute at the age of 20 years, with possible re-infection during World War I, can no longer be verified. Evidence is that he was sexually rather inactive throughout his life. Suggestions that Hitler\'s cardiac lesion and complaints such as transitory blindness, tremor of his left arm and leg, recurring abdominal pain and a skin lesion of the leg were of syphilitic aetiology cannot be supported. Hitler\'s progressive mental and physical deterioration after 1942, his growing paranoia, fits of rage, grandiosity and symptoms of possible dementia would fit in with neurosyphilis. There are, however, also other explanations for his terminal syndrome, and evidence that repeated clinical examinations did not show the characteristic signs of dementia paralytica or tabes dorsalis, swings the balance of probability away from tertiary syphilis. South African Medical Journal Vol. 95(10) 2005: 750-75
Tumours and cancers in Graeco-Roman times
In Graeco-Roman times all tumours (Greek: onkoi, abnormal swellings) were considered to be of inflammatory origin, the result of unfavourable hurnoural fluxes, and caused by an extravascular outpouring of fluid into tissue spaces. The neoplastic nature of tumours is a more recent concept, barely two centuries old. In Hippocratic literature tumours were mainly classified as karkin6mata, phumata, and oidemata. Phumata included a large variety of tumours, inflammatory and neoplastic in origin, and mostly benign (in modern terms), while oidemata were soft, painless tumours and even included generalised oedema (dropsy). Although all categories possibly included occasional cancers, the vast majority of what appears to have been malignant tumours were called karkinoi karkinomata (Latin: cancrum/carcinoma). There was, however, no recognition of benign and malignant, primary and secondary tumours, in the modem sense
The epidemic of Athens, 430 - 426 BC
The Athenian epidemic of 430 - 426 BC, at the outbreak of the Peloponnesian War, caused the death of the great statesman, Pericles, decimated the population and contributed significantly to the decline and fall of classical Greece. In his remarkable documentation of the epidemic, Thucydides (who survived the disease) not only left us a clear clinical picture of the pestilence but also identified its infectious nature and the fact that it conferred at least partial immunity on survivors. As confirmed by a large number of scholars who studied the subject, Thucydides' description does not accurately fit any existing disease, but we suggest that analysis of the signs and symptoms, considered in conjunction with significant epidemiological evidence, narrows down the many possibilities to epidemic typhus, plague, arboviral disease (e.g. Rift Valley fever) and smallpox. Typhus and smallpox fit best, but we favour the latter for reasons given. Unless further primary sources of information become available (and this seems most unlikely), productive speculation as to the cause of Thucydides' epidemic has probably reached the end of the road
Regional resilience in peripheral South Africa: The Northern Cape case
The role of regional policy mechanisms towards increased regional resilience is widely recognised, but limited consideration is given to the impact of these mechanisms in, specifically, the peripheral region. In reaction hereto, this article explores the role of three key mechanisms, i.e. economic sectoral composition, innovation and knowledge networks, as well as government institutions as policy tools towards increased regional resilience in a peripheral region in South Africa. The role of each of these mechanisms is quantified and measured by specified indices such as the GVA, the Tress Index and the ICT Access Index, and government indicators such as audit outcomes and service delivery data in five planning regions of the Northern Cape province. This article highlights that a state of dynamic stability and resilience is more feasible through policy intervention focused on these three mechanisms, coupled with detailed regional socio-economic analysis. It also emphasises that a knowledge-rich region will be less dependent on single sector development, pushing itself into a new development stage of secondary and tertiary sector focus through economic diversification, lessening its vulnerability to external shocks and disturbances, and impeding regional lock-in. In support hereto, collective institutional action by a responsive and accountable local and regional government, operating beyond their functional limits, will reinforce and amplify development in the peripheral region
Pre-Hippocratic Greek medicine and its influence on the Hippocratic Corpus
The origins of the Hippocratic Corpus, traditionally held to herald the birth of empirical medicine, are traced in the works of the “pre-Socratic” philosopher-physicians. Although it retained many of the earlier, factually incorrect hypotheses on human physiology and pathology, and consequently proposed largely ineffectual therapies, the Corpus was a decisive milestone in that it described clinical disease patterns objectively, it prescribed medication on the basis of rational argument (as understood at the time) unadulterated by considerations of religion or superstition, and it was underpinned by an ethical code which has largely withstood the test of time
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