28 research outputs found
The genetics of two colour forms of Chrysolina aurichalcea (Mannerheim) (Coleoptera: Chrysomelidae) and these gene frequencies around the Utsukushigahara Heights, central Honshu, Japan.
The inheritance pattern of the two colour forms (cyaneus-form and cupreous-form) of adult Chrysolina aurichalcea (Mannerheim) was examined by the crossing. The inheritance of these colour forms followed Mendel's law, showing the dominance of cyaneus-form over cupreous-form. The sampling of field populations around the Utsukushigahara Heights, central Honshu, Japan, was carried out at 74 sites. The estimation based on these results showed that the gene frequencies of cupreous-form were high (80-90%) at mountain areas (the sites higher than alt. 1600m) whereas they were low (20-50%) at the basins of both sides of the heights (the Matsumoto and the Ueda basins: the sites lower than alt. 800m). At the boundary of the mountain areas and the two basin areas, the gene frequency showed various rate and in some cases, it changed abruptly between the two sites which were apart from each other by a few hundreds meters. The histogram of gene frequencies among them for 8 years showed that the frequencies were fairly constant at major sites. At some sites, the phenotypic frequency of cupreous-form fluctuated very much. The causes of differentiation into two groups and of the change at some sites in phenotypic frequency were discussed with possible explanations, especially in relation to natural selection by the environmental factors.Article信州大学理学部紀要 22(2): 83-97(1987)departmental bulletin pape
A homological approach to a mathematical definition of pulmonary fibrosis and emphysema on computed tomography
Three-dimensional imaging is essential to evaluate local abnormalities and understand structure-function relationships in an organ. However, quantifiable and interpretable methods to localize abnormalities remain unestablished. Visual assessments are prone to bias, machine learning methods depend on training images, and the underlying decision principle is usually difficult to interpret. Here, we developed a homological approach to mathematically define emphysema and fibrosis in the lungs on computed tomography (CT). Using persistent homology, the density of homological features, including connected components, tunnels, and voids, was extracted from the volumetric CT scans of lung diseases. A pair of CT values at which each homological feature appeared (birth) and disappeared (death) was computed by sweeping the threshold levels from higher to lower CT values. Consequently, fibrosis and emphysema were defined as voxels with dense voids having a longer lifetime (birth-death difference) and voxels with dense connected components having a lower birth, respectively. In an independent dataset including subjects with idiopathic pulmonary fibrosis (IPF), chronic obstructive pulmonary disease (COPD), and combined pulmonary fibrosis and emphysema (CPFE), the proposed definition enabled accurate segmentation with comparable quality to deep learning in terms of Dice coefficients. Persistent homology-defined fibrosis was closely associated with physiological abnormalities such as impaired diffusion capacity and long-term mortality in subjects with IPF and CPFE, and persistent homology-defined emphysema was associated with impaired diffusion capacity in subjects with COPD. The present persistent homology-based evaluation of structural abnormalities could help explore the clinical and physiological impacts of structural changes and morphological mechanisms of disease progression