67 research outputs found

    Multi-temporal Remote Sensing Land-cover Change Detection for Biodiversity Assessment in the Berg River Catchment

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    Due to the intimate relationship that exists between land cover and biodiversity it is possible to draw inferences on the current state of the biodiversity of an area, assess the likely future pressures and plan accordingly based on an analysis of land-cover change. As a means of assessing the state of biodiversity in the Cape Floristic Region, two land-cover maps (1986/7 and 2007) were developed and demonstrated for the Berg River catchment in the Western Cape province of South Africa using multispectral Landsat Thematic Mapper (TM) data. The land-cover maps were produced to an accuracy of 85% using an object-orientated nearest neighbour supervised classification. The existing vegetation types of South Africa data set were superimposed on the newly classified remnants of natural vegetation to model changes in biodiversity. It was found that the area occupied by natural vegetation increased by more than 14%, suggesting an increase in biodiversity from 1986/7 to 2007. Considerable variation between vegetation types was, however, recorded. The land cover mapping, change analysis and biodiversity modelling methods employed by this study show that land-cover change analysis provides an ideal platform from which to initiate more intensive analyses of biodiversity change and conservation. Some limitations to the use of Landsat imagery for biodiversity monitoring are discussed

    DFTB+, a software package for efficient approximate density functional theory based atomistic simulations

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    DFTB+ is a versatile community developed open source software package offering fast and efficient methods for carrying out atomistic quantum mechanical simulations. By implementing various methods approximating density functional theory (DFT), such as the density functional based tight binding (DFTB) and the extended tight binding method, it enables simulations of large systems and long timescales with reasonable accuracy while being considerably faster for typical simulations than the respective ab initio methods. Based on the DFTB framework, it additionally offers approximated versions of various DFT extensions including hybrid functionals, time dependent formalism for treating excited systems, electron transport using non-equilibrium Green's functions, and many more. DFTB+ can be used as a user-friendly standalone application in addition to being embedded into other software packages as a library or acting as a calculation-server accessed by socket communication. We give an overview of the recently developed capabilities of the DFTB+ code, demonstrating with a few use case examples, discuss the strengths and weaknesses of the various features, and also discuss on-going developments and possible future perspectives

    Earth observation for sustainable urban planning in developing countries: needs, trends, and future directions

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    Abstract: Cities are constantly changing and authorities face immense challenges in obtaining accurate and timely data to effectively manage urban areas. This is particularly problematic in the developing world where municipal records are often unavailable or not updated. Spaceborne earth observation (EO) has great potential for providing up-to-date spatial information about urban areas. This article reviews the application of EO for supporting urban planning. In particular, the article overviews case studies where EO was used to derive products and indicators required by urban planners. The review concludes that EO has sufficiently matured in recent years but that a shift from the current focus on purely science-driven EO applications to the provision of useful information for day-to-day decision-making and urban sustainability monitoring is clearly needed

    Pattern Recognition and Event Reconstruction in Particle Physics Experiments

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    This report reviews methods of pattern recognition and event reconstruction used in modern high energy physics experiments. After a brief introduction into general concepts of particle detectors and statistical evaluation, different approaches in global and local methods of track pattern recognition are reviewed with their typical strengths and shortcomings. The emphasis is then moved to methods which estimate the particle properties from the signals which pattern recognition has associated. Finally, the global reconstruction of the event is briefly addressed.Comment: 101 pages, 58 figure

    Christianity as Public Religion::A Justification for using a Christian Sociological Approach for Studying the Social Scientific Aspects of Sport

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    The vast majority of social scientific studies of sport have been secular in nature and/or have tended to ignore the importance of studying the religious aspects of sport. In light of this, Shilling and Mellor (2014) have sought to encourage sociologists of sport not to divorce the ‘religious’ and the ‘sacred’ from their studies. In response to this call, the goal of the current essay is to explore how the conception of Christianity as ‘public religion’ can be utilised to help justify the use of a Christian sociological approach for studying the social scientific aspects of sport. After making a case for Christianity as public religion, we conclude that many of the sociological issues inherent in modern sport are an indirect result of its increasing secularisation and argue that this justifies the need for a Christian sociological approach. We encourage researchers to use the Bible, the tools of Christian theology and sociological concepts together, so to inform analyses of modern sport from a Christian perspective

    A historical overview of the classification, evolution, and dispersion of Leishmania parasites and sandflies

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    Background The aim of this study is to describe the major evolutionary historical events among Leishmania, sandflies, and the associated animal reservoirs in detail, in accordance with the geographical evolution of the Earth, which has not been previously discussed on a large scale. Methodology and Principal Findings Leishmania and sandfly classification has always been a controversial matter, and the increasing number of species currently described further complicates this issue. Despite several hypotheses on the origin, evolution, and distribution of Leishmania and sandflies in the Old and New World, no consistent agreement exists regarding dissemination of the actors that play roles in leishmaniasis. For this purpose, we present here three centuries of research on sandflies and Leishmania descriptions, as well as a complete description of Leishmania and sandfly fossils and the emergence date of each Leishmania and sandfly group during different geographical periods, from 550 million years ago until now. We discuss critically the different approaches that were used for Leishmana and sandfly classification and their synonymies, proposing an updated classification for each species of Leishmania and sandfly. We update information on the current distribution and dispersion of different species of Leishmania (53), sandflies (more than 800 at genus or subgenus level), and animal reservoirs in each of the following geographical ecozones: Palearctic, Nearctic, Neotropic, Afrotropical, Oriental, Malagasy, and Australian. We propose an updated list of the potential and proven sandfly vectors for each Leishmania species in the Old and New World. Finally, we address a classical question about digenetic Leishmania evolution: which was the first host, a vertebrate or an invertebrate? Conclusions and Significance We propose an updated view of events that have played important roles in the geographical dispersion of sandflies, in relation to both the Leishmania species they transmit and the animal reservoirs of the parasites

    Presentation probability of visual–auditory pairs modulates visually induced auditory predictions

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    Predictions about forthcoming auditory events can be established on the basis of preceding visual information. Sounds being incongruent to predictive visual information have been found to elicit an enhanced negative ERP in the latency range of the auditory N1 compared with physically identical sounds being preceded by congruent visual information. This so-called incongruency response (IR) is interpreted as reduced prediction error for predicted sounds at a sensory level. The main purpose of this study was to examine the impact of probability manipulations on the IR. We manipulated the probability with which particular congruent visual–auditory pairs were presented (83/17 vs. 50/50 condition). This manipulation led to two conditions with different strengths of the association of visual with auditory information. A visual cue was presented either above or below a fixation cross and was followed by either a high- or low-pitched sound. In 90% of trials, the visual cue correctly predicted the subsequent sound. In one condition, one of the sounds was presented more frequently (83% of trials), whereas in the other condition both sounds were presented with equal probability (50% of trials). Therefore, in the 83/17 condition, one congruent combination of visual cue and corresponding sound was presented more frequently than the other combinations presumably leading to a stronger visual–auditory association. A significant IR for unpredicted compared with predicted but otherwise identical sounds was observed only in the 83/17 condition, but not in the 50/50 condition, where both congruent visual cue–sound combinations were presented with equal probability. We also tested whether the processing of the prediction violation is dependent on the task relevance of the visual information. Therefore, we contrasted a visual–auditory matching task with a pitch discrimination task. It turned out that the task only had an impact on the behavioral performance but not on the prediction error signals. Results suggest that the generation of visual-to-auditory sensory predictions is facilitated by a strong association between the visual cue and the predicted sound (83/17 condition) but is not influenced by the task relevance of the visual information

    Investigations on Surface Defects in Gear Hobbing

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