Kume M.,Japan Aqua Restoration Research Center |
Kitano J.,Fred Hutchinson Cancer Research Center |
Mori S.,Gifu Keizai University |
Shibuya T.,Akkeshi Waterfowl Observation Center
Journal of Evolutionary Biology | Year: 2010
When two closely related species migrate to divergent spawning sites, divergent use of spawning habitats can directly reduce heterospecific mating. Furthermore, adaptations to divergent spawning habitats can promote speciation as a by-product of ecological divergence. Here, we investigated habitat isolation and ecological divergence between two anadromous forms of threespine stickleback (Gasterosteus aculeatus), the Japan Sea and Pacific Ocean forms. In several coastal regions of eastern Hokkaido, Japan, these forms migrate to the same watershed to spawn. Our field surveys in a single watershed revealed that segregation of distinct spawning sites between the two forms was maintained within the watershed across multiple years. These spawning sites diverged in salinity and predator composition. Morphological and physiological divergence between the forms also occurs in the direction predicted by ecological differences between the spawning sites. Our data indicate that migration into divergent spawning habitats can be an important mechanism contributing to speciation and phenotypic divergence in anadromous fishes. © 2010 The Authors. Journal Compilation © 2010 European Society For Evolutionary Biology.
Natsumeda T.,Chiba Institute of Science |
Mori S.,Gifu Keizai University |
Yuma M.,Ryukoku University
Journal of Ethology | Year: 2012
Despite growing evidence for plasticity in the mating patterns of nest-holding animals in relation to the changes in nest abundance, the effects of aggressive interaction by dominant males on nest availability for conspecific rivals remains unclear. To quantify the effects of male-male competition on nest-site choice and mating success of the male Japanese fluvial sculpin Cottus pollux, we conducted experiments on 5 males from different 5 size classes under both sufficient and shortage nest-abundance conditions. Nest-choice experiments showed that both male size class and nest-abundance condition had significant effects on the nesting rates of males. Following the nest-choice experiments, 10 gravid females were added in the experimental tanks. Mating experiments revealed that male size, nesting rate before addition of females, and the number of courtship attempts on females were valid variables of male mating success, regardless of nest-abundance conditions. After achieving initial mating success, the largest nesting male exhibited more frequent aggressive interaction with other conspecific males than he did before obtaining eggs in his nest. Our results suggest that size-mediated dominance and aggressive behavior of males may disrupt nest acquisition of other conspecific males, and may consequently result in extreme variation in mating success among males even under sufficient nest-abundance conditions. © 2011 Japan Ethological Society and Springer.
Sugihara K.,Gifu Keizai University
SIGGRAPH Asia 2011 Sketches, SA'11 | Year: 2011
A 3-D city model as shown in Figure 1 is important in several fields, such as urban planning and gaming industries. However, enormous time and labour has to be consumed to create these 3-D models, using 3-D modeling softwares such as 3ds Max or SketchUp. For example, when manually modeling a house with roofs by Constructive Solid Geometry (CSG), one must use the following laborious steps: (1) Generation of primitives of appropriate size, such as box, prism or polyhedron that will form parts of a house (2) Boolean operations are applied to these primitives to form the shapes of parts of a house such as making holes in a building body for doors and windows (3) Rotation of parts of a house (4) Positioning of parts of a house (5) Texture mapping onto these parts.
Kitano J.,Tohoku University |
Kitano J.,Japan Science and Technology Agency |
Kitano J.,National Institute of Genetics |
Mori S.,Gifu Keizai University |
Peichel C.L.,Fred Hutchinson Cancer Research Center
Journal of Fish Biology | Year: 2012
Sexual dimorphism in geometric body shape and external morphology was compared between marine and stream-resident forms of three-spined stickleback Gasterosteus aculeatus collected from North America and Japan. Some aspects of sexual dimorphism were shared between ecotypes: males had larger heads than females with no significant effect of ecotype on the magnitude of sexual dimorphism. By contrast, a significant sex-by-ecotype interaction was found for body depth. Males tended to have deeper bodies than females in both forms, but the magnitude of sexual dimorphism was reduced in stream-resident forms. Although females were generally larger in standard length and had larger pelvic girdles, significant sexual dimorphism in these traits was not consistently found across populations or ecotypes. These results suggest that some aspects of sexual dimorphism were shared between ecotypes, while others were unique to each population. The results further suggest that ecology may influence the evolution of sexual dimorphism in some external morphological traits, such as body depth. © 2011 The Fisheries Society of the British Isles.
Sugihara K.,Gifu Keizai University |
Kikata J.,Kagoshima University
Journal of Computing in Civil Engineering | Year: 2013
A three-dimensional (3D) urban model is an important information infrastructure that can be utilized in several fields, such as urban planning and game industries. However, enormous time and effort have to be spent to create 3D urban models using 3D modeling software. This paper employs automatic generation of 3D building models through integrating geographic information systems (GIS) and computer graphics. An integrated system is proposed for automatically creating 3D building models from building polygons (building footprints) on a digital map. Because most building polygons' edges meet at a right angle (orthogonal polygon), the integrated system partitions orthogonal building polygons into a set of rectangles and places rectangular roofs and box-shaped building bodies on these rectangles. In this research, a new scheme for partitioning complicated orthogonal building polygons is proposed. In the digital map, however, not all building polygons are orthogonal. To place parts of a building properly, in either orthogonal or nonorthogonal polygons, the proposed system places parts of a building, such as windows along the inner contour, which is set back from the original building polygon by straight skeleton computation. For a multiple-bounded polygon (a building polygon bounded by outer polygons), a new scheme is also presented for creating a complicated building-shape model or a multilayer building. © 2013 American Society of Civil Engineers.