scholarly journals Spatial Congruence Analysis (SCAN): A method for detecting biogeographical patterns based on species range congruences

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0245818
Author(s):  
Cassiano A. F. R. Gatto ◽  
Mario Cohn-Haft

Species with congruent geographical distributions, potentially caused by common historical and ecological spatial processes, constitute biogeographical units called chorotypes. Nevertheless, the degree of spatial range congruence characterizing these groups of species is rarely used as an explicit parameter. Methods conceived for the identification of patterns of shared ranges often suffer from scale bias associated with the use of grids, or the incapacity to describe the full complexity of patterns, from core areas of high spatial congruence, to long gradients of range distributions expanding from these core areas. Here, we propose a simple analytical method, Spatial Congruence Analysis (SCAN), which identifies chorotypes by mapping direct and indirect spatial relationships among species. Assessments are made under a referential value of congruence as an explicit numerical parameter. A one-layered network connects species (vertices) using pairwise spatial congruence estimates (edges). This network is then analyzed for each species, separately, by an algorithm which searches for spatial relationships to the reference species. The method was applied to two datasets: a simulated gradient of ranges and real distributions of birds. The simulated dataset showed that SCAN can describe gradients of distribution with a high level of detail. The bird dataset showed that only a small portion of range overlaps is biogeographically meaningful, and that there is a large variation in types of patterns that can be found with real distributions. Species analyzed separately may converge on similar or identical groups, may be nested in larger chorotypes, or may even generate overlapped patterns with no species in common. Chorotypes can vary from simple ones, composed by few highly congruent species, to complex, with numerous alternative component species and spatial configurations, which offer insights about possible processes driving these patterns in distinct degrees of spatial congruence. Metrics such as congruence, depth, richness, and ratio between common and total areas can be used to describe chorotypes in detail, allowing comparisons between patterns across regions and taxa.

2021 ◽  
Author(s):  
Cassiano A F R Gatto ◽  
Mario Cohn-Haft

AbstractSimilar species ranges may represent outcomes of common biological processes and so form the basis for biogeographical concepts such as areas of endemism and ecoregions. Nevertheless, spatial range congruence is rarely quantified, much less incorporated in bioregionalization methods as an explicit parameter. Furthermore, most available methods suffer from limitations related to the loss, or the excess of range information, or scale bias associated with the use of grids, and the incapacity to recognize independent overlapped patterns or gradients of range distributions. Here, we propose an analytical method, Spatial Congruence Analysis (SCAN), to identify biogeographically meaningful groups of species, called biogeographic elements. Such elements are based on direct and indirect spatial relationships among species’ ranges and vary depending on an explicit measure of range congruence controlled as a numerical parameter in the analysis. A one-layered network connects species (vertices) using pairwise spatial congruence estimates (edges). This network is then analyzed for each species, separately, by an algorithm that accesses the entire web of spatial relationships to the reference species. The method was applied to two datasets: a simulated gradient of ranges and real distributions of birds. The gradient results showed that SCAN can describe gradients of distribution with a high level of detail, without confounding transition zones with true biogeographical units, a frequent pitfall of other methods. The bird dataset showed that only a small portion of range overlaps is biogeographically meaningful, and that there is a large variation in types of patterns that can be found with real distributions. Distinct reference species may converge on similar or identical groups of spatially related species, may lead to recognition of nested species groups, or may even generate similar spatial patterns with no species in common. The biological significance or causal processes of these patterns should be investigated a posteriori. Patterns can vary from simple ones, composed by few highly congruent species, to complex, with numerous alternative component species and spatial configurations, depending on particular parameter settings as determined by the investigator. This approach eliminates or reduces limitations of other methods and permits pattern description without hidden assumptions about processes, and so should make a valuable contribution to the biogeographer’s toolbox.“If there is any basic unit of biogeography, it is the geographic range of a species.” - Brown, Stevens & Kaufman [1].“[spatial] congruence […] should be optimized, while realizing that this criterion will most likely never be fully met” - HP Linder [2].


2006 ◽  
Vol 27 (4) ◽  
pp. 218-228 ◽  
Author(s):  
Paul Rodway ◽  
Karen Gillies ◽  
Astrid Schepman

This study examined whether individual differences in the vividness of visual imagery influenced performance on a novel long-term change detection task. Participants were presented with a sequence of pictures, with each picture and its title displayed for 17  s, and then presented with changed or unchanged versions of those pictures and asked to detect whether the picture had been changed. Cuing the retrieval of the picture's image, by presenting the picture's title before the arrival of the changed picture, facilitated change detection accuracy. This suggests that the retrieval of the picture's representation immunizes it against overwriting by the arrival of the changed picture. The high and low vividness participants did not differ in overall levels of change detection accuracy. However, in replication of Gur and Hilgard (1975) , high vividness participants were significantly more accurate at detecting salient changes to pictures compared to low vividness participants. The results suggest that vivid images are not characterised by a high level of detail and that vivid imagery enhances memory for the salient aspects of a scene but not all of the details of a scene. Possible causes of this difference, and how they may lead to an understanding of individual differences in change detection, are considered.


2010 ◽  
pp. 194-208 ◽  
Author(s):  
Francesco Bellotti ◽  
Riccardo Berta ◽  
Alessandro De Gloria ◽  
Ludovica Primavera

Virtual reality environments are ever more going online. This trend, opened by videogames, will open new important opportunities to enhance cultural tourism, given the possibility of creating compelling virtual adventures set in the context of artistic and natural beauties. The authors are exploring these challenges in the context of the Travel in Europe (TiE) project, and developing tools to build enriched virtual environments where the player could explore faithfully reconstructed places and live there information-rich, contextualized experiences. The TiE architecture is based on a state-of-the-art commercial game engine, with massive multiplayer online games (MMOG) facilities that support access to multiple concurrent users, plus ad-hoc designed modules. The 3D model is completely geo-referenced. In each covered area, a few points-of-interest (POIs) are implemented. These buildings are rigorously reconstructed at a high level of detail. The textures for the rest of the palaces are built dynamically by the TiE system using a statistical template-based algorithm that exploits local characterizations of common architectonic elements. The TiE virtual world is enriched by geo-localized, contextualized MicroGames (mGs). mGs are simple, short games that focus the player’s attention on a particular item that is found during exploration of the 3D world. mGs are typically taken from well known simple game models, such as Puzzle, MemoryGame, and FindTheWrongDetails. The main concept that underpins mGs is that, they should be intuitive and easy to play, so that the player can focus on the contents rather than on learning how to play. Preliminary informal tests have suggested that the approach is valid and that the enriched 3D environment supports the contextualized promotion of artifacts, products and services, which is an important growing demand from institutions and enterprises that want to valorize the resources of a territory.


Author(s):  
Florian Hruby ◽  
Irma Castellanos ◽  
Rainer Ressl

Abstract Scale has been a defining criterion of mapmaking for centuries. However, this criterion is fundamentally questioned by highly immersive virtual reality (VR) systems able to represent geographic environments at a high level of detail and, thus, providing the user with a feeling of being present in VR space. In this paper, we will use the concept of scale as a vehicle for discussing some of the main differences between immersive VR and non-immersive geovisualization products. Based on a short review of diverging meanings of scale we will propose possible approaches to the issue of both spatial and temporal scale in immersive VR. Our considerations shall encourage a more detailed treatment of the specific characteristics of immersive geovisualization to facilitate deeper conceptual integration of immersive and non-immersive visualization in the realm of cartography.


Author(s):  
D. Gajski ◽  
A. Solter ◽  
M. Gašparovic

Many valuable archaeological artefacts have the size of a few centimetres or less. The production of relevant documentation of such artefacts is mainly limited to subjective interpretation and manual drawing techniques using a magnifier. Most of the laser scanners available for the archaeological purposes cannot reach sufficient space resolution to gather all relevant features of the artefact, such as the shape, the relief, the texture and any damage present. Digital photogrammetric techniques make measuring with high accuracy possible and such techniques can be used to produce the relevant archaeometric documentation with a high level of detail. The approaches for shooting a good macro photograph (in the photogrammetric sense) will be explored and discussed as well as the design of a calibration test-field and the self-calibration methods suitable for macro photogrammetry. Finally, the method will be tested by producing a photorealistic 3D-model of an ancient figurine.


2021 ◽  
Vol 855 (1) ◽  
pp. 012021
Author(s):  
G M Colleto ◽  
V Gomes

Abstract Understanding the built environment’s impacts is essential to support strategic planning and policy design for sustainable development now, and in the future. Modelling individual buildings and infrastructure at high level of detail is resource intensive. Thus, urban scale analyses demand simplifications that balance level of detail and scope broadness. For combining simplified modelling and extended scope, classification by archetypes emerge as a promising methodological approach to extend assessment scope beyond energy use simulation. Archetypes that include life cycle assessment (LCA) parameters can support circularity challenges diagnosis, mapping and predictions, strategies to close material and energy loops and their monitoring within urban built environments. We hypothesized that, upon limited complementation, operational and pre/post construction (embodied) datasets coupled with building grouping techniques satisfactorily represent the built stock to support cradle to grave LCA of built environments. Studies on the use of archetypes for this purpose are scarce, so this article reports findings of a Systematic Literature Review (SLR) on archetypes-based approaches for energy assessment that could inspire application in LCA studies at urban scale. The SLR highlighted a lack of methodological consensus, and that data availability seems to be the major limitation for archetype creation in most studies, which rarely present in-depth information on their development. The few investigations providing consistent methodological procedures actually detail the initial classification process. Transposing the archetype strategy from energy assessment to LCA at urban scale faces practical limitations. Several databases support operational energy studies, but the same does not apply to LCA. Urban building energy models typically overlook infrastructure. Also, statistical results depend directly on data input quality and data availability may compromise the quality of variable selection.


2018 ◽  
Vol 74 (6) ◽  
pp. 545-559 ◽  
Author(s):  
Thomas C. Terwilliger ◽  
Oleg V. Sobolev ◽  
Pavel V. Afonine ◽  
Paul D. Adams

An algorithm for automatic map sharpening is presented that is based on optimization of the detail and connectivity of the sharpened map. The detail in the map is reflected in the surface area of an iso-contour surface that contains a fixed fraction of the volume of the map, where a map with high level of detail has a high surface area. The connectivity of the sharpened map is reflected in the number of connected regions defined by the same iso-contour surfaces, where a map with high connectivity has a small number of connected regions. By combining these two measures in a metric termed the `adjusted surface area', map quality can be evaluated in an automated fashion. This metric was used to choose optimal map-sharpening parameters without reference to a model or other interpretations of the map. Map sharpening by optimization of the adjusted surface area can be carried out for a map as a whole or it can be carried out locally, yielding a locally sharpened map. To evaluate the performance of various approaches, a simple metric based on map–model correlation that can reproduce visual choices of optimally sharpened maps was used. The map–model correlation is calculated using a model withBfactors (atomic displacement factors; ADPs) set to zero. This model-based metric was used to evaluate map sharpening and to evaluate map-sharpening approaches, and it was found that optimization of the adjusted surface area can be an effective tool for map sharpening.


Author(s):  
Ian A. Sigal ◽  
Hongli Yang ◽  
Michael D. Roberts ◽  
J. Crawford Downs

Biomechanical response is often influenced by the geometry (shape) of a system. Numerical techniques such as the finite element (FE) method offer the possibility of incorporating geometric details of a system into a mathematical model with a greater level of detail than is generally achievable with purely analytical models. In this vein, FE models of biological structures tend to fall into two broad categories: generic models and specimen-specific models. Generic models are attractive because the geometric features of interest may be cast as variable parameters that simplify analysis of factor influence, but may be limited in what can be predicted about a specific specimen. In contrast, specimen-specific models may contain a high level of geometric detail, but analysis of the influence of geometry can be more complicated.


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