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Yang X.,Shanghai JiaoTong University | Hamaguchi S.,App TOKYO Co. | Sun Y.,Shanghai JiaoTong University | Xiao S.,Shanghai JiaoTong University
Proceedings - 2011 4th International Conference on Biomedical Engineering and Informatics, BMEI 2011 | Year: 2011

Detection of optic disk (OD) in fundus image is a standard procedure before the diagnosis and analysis of various serious ophthalmic pathologies. Manual detection will consume both time and energy. Therefore automatically detection is rather necessary and practical. However, owing to uneven illumination, disorder distribution of optic vessels or noises in the fundus images, this task has constantly been challenging. In this paper, a novel method based on Gaussian vessel detector with contrast tuning, morphology operations and tangent information, is presented to detect OD from retinal fundus images. After converting the color image to grayscale image by its green channel, image contrast is tuned intended for the subsequent vessel detection. Proceeded with Gaussian vessel detector, the search space for the later operation will be restricted to a limited dimension. Next, morphology operations as well as denoising operations guarantee that interferences of trivial vessels or noise eliminated. Eventually, by applying the tangent information transformation on the pre-processed image, the center of the Optic disc is determined. This method achieved a success ratio of 91.3 (74 out of 81 images) in the standard database S.T.A.R.E. The experimental result shows that the proposed method is effective and could approximate the average accuracy of a human observer. © 2011 IEEE.

Suzuki H.,Hokkaido University | Nunome M.,Hokkaido University | Kinoshita G.,Hokkaido University | Aplin K.P.,Smithsonian Institution | And 10 more authors.
Heredity | Year: 2013

We examined the sequence variation of mitochondrial DNA control region and cytochrome b gene of the house mouse (Mus musculus sensu lato) drawn from ca. 200 localities, with 286 new samples drawn primarily from previously unsampled portions of their Eurasian distribution and with the objective of further clarifying evolutionary episodes of this species before and after the onset of human-mediated long-distance dispersals. Phylogenetic analysis of the expanded data detected five equally distinct clades, with geographic ranges of northern Eurasia (musculus, MUS), India and Southeast Asia (castaneus, CAS), Nepal (unspecified, NEP), western Europe (domesticus, DOM) and Yemen (gentilulus). Our results confirm previous suggestions of Southwestern Asia as the likely place of origin of M. musculus and the region of Iran, Afghanistan, Pakistan, and northern India, specifically as the ancestral homeland of CAS. The divergence of the subspecies lineages and of internal sublineage differentiation within CAS were estimated to be 0.37-0.47 and 0.14-0.23 million years ago (mya), respectively, assuming a split of M. musculus and Mus spretus at 1.7 mya. Of the four CAS sublineages detected, only one extends to eastern parts of India, Southeast Asia, Indonesia, Philippines, South China, Northeast China, Primorye, Sakhalin and Japan, implying a dramatic range expansion of CAS out of its homeland during an evolutionary short time, perhaps associated with the spread of agricultural practices. Multiple and non-coincident eastward dispersal events of MUS sublineages to distant geographic areas, such as northern China, Russia and Korea, are inferred, with the possibility of several different routes. © 2013 Macmillan Publishers Limited.

Kirihara T.,Hokkaido University | Shinohara A.,University of Miyazaki | Tsuchiya K.,App TOKYO Co. | Harada M.,Osaka City University | And 2 more authors.
Zoological Science | Year: 2013

We assessed dispersal and vicariant events in four species of Japanese moles in the genera Mogera and Euroscaptor to better understand the factors shaping intra- and interspecific differentiation in Japanese moles. We used the combined viewpoints of molecular phylogeny and historical geology using nucleotide sequences of mitochondrial (cytochrome b; Cytb) and nuclear (A2ab, Bmp4, Tcf25, vWf) genes. The divergence times estimated from the molecular data were verified with available geological data on the chronology of fluctuations in sea level in the Korea Strait, assuming sequential migration and speciation events. This produced possible migration times of 5.6, 3.5, 2.4, and 1.3 million years ago for four species of Japanese moles, Euroscaptor mizura, Mogera tokudae, M. imaizumii, and M. wogura, respectively. For the western Japanese mole M. wogura, Cytb sequences revealed four major phylogroups with strong geographic affinities in southwestern Central Honshu (I), western Honshu/Shikoku (II), Kyushu/westernmost Honshu (III), and Korea/Russian Primorye (IV). The nuclear gene sequences supported the distinctiveness of phylogroups I and IV, indicating long, independent evolutionary histories. In contrast, phylogroups II and III were merged into a single geographic group based on the nuclear gene data. Intraspecific divergences in M. imaizumii and M. tokudae were rather apparent in Cytb but not in nuclear gene sequences. The results suggest that repeated dispersal events have occurred between the Asian continent and the Japanese Islands, and intensive vicariant events associated with abiotic and biotic factors have created higher levels of species and genetic diversities in moles occurring on the Japanese Islands. © 2013 Zoological Society of Japan.

Nakahara K.,Osaka University | Mitsui C.,Osaka University | Okamoto T.,Osaka University | Yamagishi M.,Osaka University | And 5 more authors.
Chemistry Letters | Year: 2013

We focus on aggregated structures and charge-transporting properties in semiconductor assemblies of a new-type twisted π-conjugated molecule, dinaphtho[2,1-b:1′,2′-d]furan (DNF-U). Single crystals were successfully grown by physical vapor transport to form a two-dimensional herringbone packing structure, which is advantageous for intermolecular charge transport. Based on the packing structure, relatively large transfer integrals were theoretically calculated to be 20 and 57 meV for C-H π and π π direction, respectively. The single-crystal field-effect transistors exhibited notable hole mobility of up to 1.0 cm2V-1 s-11. © 2013 The Chemical Society of Japan.

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