Congenital Anomalies in Human Embryos

Morphogenesis mainly occurs during embryonic stage, and congenital anomalies also occur at that time. The Kyoto Collection, one of the largest collections of human embryos, including a lot of those with congenital anomalies, is significantly helpful for analyzing embryonic growth. From the collection, normal and abnormal embryos have been selectively presented in this chapter. Recently developed imaging technology enabled three-dimensional (3D) imaging of embryos and fetuses in high resolution. The devices available for embryonic and fetal imaging and the results obtained therefrom are introduced in this chapter. In addition, new strategies for diagnosing congenital anomalies, such as autopsy imaging and genetic analyses, are discussed

Prolonged maturation of prefrontal white matter in chimpanzees

Delayed maturation in the prefrontal cortex, a brain region associated with complex cognitive processing, has been proposed to be specific to humans. However, we found, using a longitudinal design, that prefrontal white matter volume in chimpanzees increased gradually with age, and the increase appears to continue beyond the onset of puberty, as in humans. This provides the first evidence for a prolonged period of prefrontal connection elaboration in great apes

FLORA AND VEGETATION OF NACHOLA, SAMBURU DISTRICT, NORTHERN KENYA: A STUDY OF VEGETATION IN AN ARID LAND

Although patchy vegetation of open grassland and closed woodland or forest is often reconstructed as a habitat of early hominids, there are few studies of modern vegetation of this type. Vegetational and floral study in Nachola, northern Kenya aimed to remedy this lack. It appeared to have 160 species, which accords well with treated physiognomical classifications of semi arid open vegetations in northern Kenya. There are two contrasting types of vegetation i.e. riverine forest and grassland. Riverine forest comprises two dominant species and several tree species. Grassland has less biomass and despite its name, grass is rare. Instead, dwarf shrubs of Labiatae dominate the surface of the land. Riverine forest in Nachola has two major species, both producing fruits edible to frugivorous mammals, Ficus sycomorus and Acacia tortilis ssp. spirocarpa. Fruit production is suggested to be greater in F. sycomorus. Possibility of early hominid habitats should be discussed based on such an analysis of modern equivalents

FICUS SYCOMORUS FRUIT PRODUCTION IN A SEMI ARID LAND IN NORTHERN KENYA: IMPLICATIONS FOR UNDERSTANDING A POSSIBLE FOOD RESOURCE OF EARLY HOMINIDS

Food production of riverine forest in semi arid land, or patchy vegetation in northern Kenya is much needed for discussing the habitat of early hominids. This study aims to estimate the fruit production of Ficus sycomorus along the Baragoi River in Nachola and Baragoi, northern Kenya, possible source for the Pliocene australopithecines. As the largest fruit producer in the forest, the population of F. sycomorus in this riverine forest is counted and the Basal Area of all individuals measured. The number of fruits and their weights are also measured. The total production can be estimated to know the carrying capacity of this forest. The energy yielded by F. sycomorus of this population calculated is at least 74, 500 kcal per day. This amount of energy suggests enough for a small group of early hominids during the period of food scarcity

ホクブ ケニア カンソウチ カヘリン ト ショキ ヒトカ セイソクチ リカイ ニ カンレンスル ブンセキ

京都大学0048新制・課程博士博士(理学)甲第10000号理博第2661号新制||理||1354(附属図書館)UT51-2003-H421京都大学大学院理学研究科生物科学専攻(主査)教授 石田 英実, 教授 西田 利貞, 教授 米井 脩治学位規則第4条第1項該当Doctor of ScienceKyoto UniversityDA

Fetal brain development in chimpanzees versus humans.

世界で初めてチンパンジー胎児の脳成長が明らかに : ヒトの脳の巨大化はすでに胎児期からスタート. 京都大学プレスリリース. 2012-09-25.It is argued that the extraordinary brain enlargement observed in humans is due to not only the human-specific pattern of postnatal brain development, but also to that of prenatal brain development [1, 2]. However, the prenatal trajectory of brain development has not been explored in chimpanzees (Pan troglodytes), even though they are our closest living relatives. To address this lack of information, we tracked fetal development of the chimpanzee brain from approximately 14 to 34 weeks of gestation (just before birth) in utero using three-dimensional ultrasound imaging. The results were compared with those obtained for the human brain during approximately the same period. We found that the brain volume of chimpanzee fetuses was only half that of human fetuses at 16 weeks of gestation. Moreover, although the growth velocity of brain volume increased until approximately 22 weeks of gestation in both chimpanzees and humans, chimpanzee fetuses did not show the same accelerated increase in brain volume as human fetuses after that time. This suggests that maintenance of fast development of the human brain during intrauterine life has contributed to the remarkable brain enlargement observed in humans

Non-rigid registration of serial section images by blending transforms for 3D reconstruction

複数のスライスされた標本から元の立体形状を復元する画像処理技術を開発 --ヒトの成長過程の解明にも寄与--. 京都大学プレスリリース. 2019-08-02.In this research, we propose a novel registration method for three-dimensional (3D) reconstruction from serial section images. 3D reconstructed data from serial section images provides structural information with high resolution. However, there are three problems in 3D reconstruction: non-rigid deformation, tissue discontinuity, and accumulation of scale change. To solve the non-rigid deformation, we propose a novel non-rigid registration method using blending rigid transforms. To avoid the tissue discontinuity, we propose a target image selection method using the criterion based on the blending of transforms. To solve the scale change of tissue, we propose a scale adjustment method using the tissue area before and after registration. The experimental results demonstrate that our method can represent non-rigid deformation with a small number of control points, and is robust to a variation in staining. The results also demonstrate that our target selection method avoids tissue discontinuity and our scale adjustment reduces scale change