72 research outputs found

    Interaction and evolutionary algorithms

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    Evolution and Interaction are two processes in Computer Science that are used in many algorithms to create, shape, find and optimize solutions to real world problems. Evolution has been very successfully applied as a pow-erful tool to solve complex search problems in fields ranging from physics, chemistry and biology all the way to commercial application such as aircraft fuselage design and civil engineering grading plans. Defining interaction is a big part of algorithm design. Not only defining the inputs and outputs of an algorithm but for a complex algorithm the interactions inside of an al- gorithm are as important. This thesis will concentrate on where Evolution overlaps Interaction. It will show how evolution can be used to evolve in- teraction, how the interaction inside an evolutionary algorithm impacts its performance and how an evolutionary algorithm can interact with humans. By touching on these three forms of overlap this thesis tries to give insight into the world of evolution and interactionThis work is part of the research programme of the Foun-dation for Fundamental Research on Matter (FOM), which is part of the Netherlands Organisation for Scientific Re-search (NWO). FOM Project: An evolutionary approach to many-parameter physics, project nr.: 03TF78-2, werkgroep FOM-L-24UBL - phd migration 201

    Computer-implemented land planning system and method

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    US10380270B2Algorithms and the Foundations of Software technolog

    Computer-implemented land planning system and method with GIS integration

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    US 10,614,255 B2Algorithms and the Foundations of Software technolog

    A Cognitive Model of an Epistemic Community: Mapping the Dynamics of Shallow Lake Ecosystems

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    We used fuzzy cognitive mapping (FCM) to develop a generic shallow lake ecosystem model by augmenting the individual cognitive maps drawn by 8 scientists working in the area of shallow lake ecology. We calculated graph theoretical indices of the individual cognitive maps and the collective cognitive map produced by augmentation. The graph theoretical indices revealed internal cycles showing non-linear dynamics in the shallow lake ecosystem. The ecological processes were organized democratically without a top-down hierarchical structure. The steady state condition of the generic model was a characteristic turbid shallow lake ecosystem since there were no dynamic environmental changes that could cause shifts between a turbid and a clearwater state, and the generic model indicated that only a dynamic disturbance regime could maintain the clearwater state. The model developed herein captured the empirical behavior of shallow lakes, and contained the basic model of the Alternative Stable States Theory. In addition, our model expanded the basic model by quantifying the relative effects of connections and by extending it. In our expanded model we ran 4 simulations: harvesting submerged plants, nutrient reduction, fish removal without nutrient reduction, and biomanipulation. Only biomanipulation, which included fish removal and nutrient reduction, had the potential to shift the turbid state into clearwater state. The structure and relationships in the generic model as well as the outcomes of the management simulations were supported by actual field studies in shallow lake ecosystems. Thus, fuzzy cognitive mapping methodology enabled us to understand the complex structure of shallow lake ecosystems as a whole and obtain a valid generic model based on tacit knowledge of experts in the field.Comment: 24 pages, 5 Figure

    Quantifying measures to limit wind driven resuspension of sediments for improvement of the ecological quality in some shallow Dutch lakes

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    Although phosphorus loadings are considered the main pressure for most shallow lakes, wind-driven resuspension can cause additional problems for these aquatic ecosystems. We quantified the potential effectiveness of measures to reduce the contribution of resuspended sediments, resulting from wind action, to the overall light attenuation for three comparable shallow peat lakes with poor ecological status in the Netherlands: Loosdrecht, Nieuwkoop, and Reeuwijk (1.8–2.7 m depth, 1.6–2.5 km fetch). These measures are: 1. wave reducing barriers, 2. water level fluctuations, 3. capping of the sediment with sand, and 4. combinations of above. Critical shear stress of the sediments for resuspension (Vcrit), size distribution, and optical properties of the suspended material were quantified in the field (June 2009) and laboratory. Water quality monitoring data (2002–2009) showed that light attenuation by organic suspended matter in all lakes is high. Spatial modeling of the impact of these measures showed that in Lake Loosdrecht limiting wave action can have significant effects (reductions from 6% exceedance to 2% exceedance of Vcrit), whereas in Lake Nieuwkoop and Lake Reeuwijk this is less effective. The depth distribution and shape of Lake Nieuwkoop and Lake Reeuwijk limit the role of wind-driven resuspension in the total suspended matter concentration. Although the lakes are similar in general appearance (origin, size, and depth range) measures suitable to improve their ecological status differ. This calls for care when defining the programme of measures to improve the ecological status of a specific lake based on experience from other lakes.

    Genetic variants associated with longitudinal changes in brain structure across the lifespan

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    Human brain structure changes throughout the lifespan. Altered brain growth or rates of decline are implicated in a vast range of psychiatric, developmental and neurodegenerative diseases. In this study, we identified common genetic variants that affect rates of brain growth or atrophy in what is, to our knowledge, the first genome-wide association meta-analysis of changes in brain morphology across the lifespan. Longitudinal magnetic resonance imaging data from 15,640 individuals were used to compute rates of change for 15 brain structures. The most robustly identified genes GPR139, DACH1 and APOE are associated with metabolic processes. We demonstrate global genetic overlap with depression, schizophrenia, cognitive functioning, insomnia, height, body mass index and smoking. Gene set findings implicate both early brain development and neurodegenerative processes in the rates of brain changes. Identifying variants involved in structural brain changes may help to determine biological pathways underlying optimal and dysfunctional brain development and aging

    Genetic variants associated with longitudinal changes in brain structure across the lifespan

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    Human brain structure changes throughout the lifespan. Altered brain growth or rates of decline are implicated in a vast range of psychiatric, developmental and neurodegenerative diseases. In this study, we identified common genetic variants that affect rates of brain growth or atrophy in what is, to our knowledge, the first genome-wide association meta-analysis of changes in brain morphology across the lifespan. Longitudinal magnetic resonance imaging data from 15,640 individuals were used to compute rates of change for 15 brain structures. The most robustly identified genes GPR139, DACH1 and APOE are associated with metabolic processes. We demonstrate global genetic overlap with depression, schizophrenia, cognitive functioning, insomnia, height, body mass index and smoking. Gene set findings implicate both early brain development and neurodegenerative processes in the rates of brain changes. Identifying variants involved in structural brain changes may help to determine biological pathways underlying optimal and dysfunctional brain development and aging

    Organismal stoichiometry at the temporal scale: Seasonal variability shapes interspecific differences in fish

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    Abstract Changes in organismal stoichiometry (OS) may be driven by seasonal changes in lipid reserves (i.e. energy) and gonadal development in fish. However, these relationships are understudied. Hence, we investigated how seasonal changes in body lipid content and gonadal development can drive the seasonal variability of OS traits at the example of three coexisting freshwater fish species. Furthermore, we aimed to assess the importance of seasonal OS alteration in comparison with interspecific differences. Carbon (%C), nitrogen (%N) and phosphorus (%P) contents, and the molar ratios of these elements (C:N, C:P and N:P) were examined in rudd (Scardinius erythrophthalmus), pumpkinseed (Lepomis gibbosus) and Amur sleeper (Perccottus glenii). We consider the sex and seasonal changes in body size as a potential factor in shaping OS. Substantial seasonal intraspecific variability occurred in all OS traits. Its extent exceeded interspecific differences in %C, %N and C:N, while %P and C:P, N:P were determined primarily by species identity. The effect of sex occurred sporadically and was considerable in some cases. Seasonal changes in total length did not contribute to intraspecific variability of OS. Intra-annual changes in body lipid content affected seasonal variability of OS traits substantially, but the strength of this effect was species-specific. The regulatory role of lipid reserve alterations worked only for those species that exhibited considerable seasonal variation in body fat content. Gonado-somatic index proved to be marginal in shaping seasonal changes in OS, presumably because a substantial portion of the essential elemental demand for gonadal growth is supplied by rearrangements within the body, without notable changes in the entire elemental composition. In the light of our findings, we suggest that more attention should be given to the influence of seasonal variability in OS traits, and sex should be considered as a taxon-dependent effect. Ignoring this substantial degree of variability might lead to inaccuracies in assessing the extent of both intra- and interspecific OS differences. We conclude that seasonal OS variability might shape consumer-driven nutrient dynamics
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