Long-term persisting hybrid swarm and geographic difference in hybridization pattern: genetic consequences of secondary contact between two Vincetoxicum species (Apocynaceae-Asclepiadoideae)

Background: During glacial periods, glacial advances caused temperate plant extirpation or retreat into localized warmer areas, and subsequent postglacial glacial retreats resulted in range expansions, which facilitated secondary contact of previously allopatric isolated lineages. The evolutionary outcomes of secondary contact, including hybrid zones, dynamic hybrid swarm, and resultant hybrid speciation, depends on the strengths of reproductive barriers that have arisen through epistatic and pleiotropic effects during allopatric isolation. The aim of this study was to demonstrate refugia isolation and subsequent secondary contact between two perennial Asclepioid species and to assess the genetic consequences of the secondary contact. We modeled the range shift of two ecologically distinct Vincetoxicum species using the species distribution model (SDM) and assessed the genetic consequences of secondary contact by combining morphological and genetic approaches. We performed morphometric analysis (592 individuals) and examined 10 nuclear microsatellites (671 individuals) in V. atratum, V. japonicum, and putative hybrid populations. Results: Multivariate analysis, model-based Bayesian analysis, and non-model-based discriminant analysis of principal components confirmed the hybridization between V. atratum and V. japonicum. High pollen fertility and a lack of linkage disequilibrium suggested that the hybrid populations may be self-sustaining and have persisted since V. atratum and V. japonicum came into contact during the post-glacial period. Moreover, our findings show that the pattern of hybridization between V. atratum and V. japonicum is unidirectional and differs among populations. Geographically-isolated hybrid populations exist as genetically distinct hybrid swarms that consist of V. atratum-like genotypes, V. japonicum-like genotypes, or admixed genotypes. In addition, Bayesian-based clustering analysis and coalescent-based estimates of long-term gene flow showed patterns of introgressive hybridization in three morphologically ‘pure’ V. japonicum populations. Conclusion: In this study, we demonstrated that climatic oscillations during the Quaternary period likely led to species range shift and subsequently secondary contact. Hybrid populations may be self-sustaining and have persisted since V. atratum and V. japonicum came into contact during the post-glacial period. Pattern of hybridization between V. atratum and V. japonicum is unidirectional and differs among populations. We concluded that these differences in the genetic consequences of secondary contact are caused by historical colonization processes and/or natural selection

Bacteremia Derived from Clinical Materials on Blood Culture and Catheter Tip after Intravenous Infusion Therapy in a University Hospital

中心静脈内にカテーテル(以下CVCとする)を挿入して行う輸液管理は重症患者への医療には欠くことの出来ないものとなっている一方, カテーテル留置に伴う血流感染の危険性は高い。大学病院におけるCVC由来血流感染症の実態を明らかにするため, 1996年1月から1998年12月までの3年間に広島大学医学部附属病院での各診療科別にみた微生物検査室へのCVCおよび血液の培養依頼状況およびその結果を明らかにした。本調査ではCVCおよび血液の培養の原因菌が一致し, それらの症例について, 薬剤感受性やカルテの内容からCVC挿入が血流感染の直接的な原因になっていたか否かを検討することによりCVC由来菌血症と定義した。血液およびCVCの検査依頼総数は2,233件, 菌検出検体は283件, 検出率は12.7%であった。3年間に検出された菌種の過半数は, 血液およびCVC共にグラム陽性球菌であった。診療科により検出される菌の種類, またその数の違いが見られており, 外科系においてはグラム陽性菌の検出数が多く, 内科系ではグラム陰性菌の検出数が多い傾向が見られたが, 統計的な有意差は認められなかった。血液とCVCから同種の菌検出が認められた症例は13件であり, 1996年に6件, 1997年に5件, 1998年に2件であった。これらの症例を検討した結果, 明らかにCVC由来感染と考えられたものは各年毎2例であり, 原因菌以外の操作中の汚染として見過ごされがちなCoagulase negative-staphylococciが多く見られた。これらのことから, CVC由来血流感染を防止し, 患者の生命予後を改善していくため, CVCを用いた輸液管理に関する正しい理解と正確な技術に基づいたルート管理の必要性が考えられた。To clarify the contamination pattern of samples from central venous catheter tip and blood, all submitted materials by each clinical department from Jan. 1996 to Dec. 1998 were summarized the contaminated cases were determined whether to be catheter-related bacteremia or not. Positive samples were counted as well as those in which bacteria were matched between the catheter tip and the blood. We further checked the later cases from the viewpoint of antibiotic sensitivity and other information in the clinical chart to decide whether the patient had catheter-related bacteremia or not. The total sample materials were 2,233,including 283 (12.7%) bacteria-positive samples. More than halves of the bacteria specimens were gram positive cocci. Detected bacteria differed according to the clinical department. More of the bacteria were gram positive cocci than gram-negative bacilli, the former dominant in the surgical departments than the latter in the non-surgical departments. But these difference were not significant statistically. In thirteen cases, the same bacteria were detected in both the central venous catheter tip and the blood, including six cases in 1996,5 cases in 1997,and 2 cases in 1998,and definitive catheter-related bacteremia was found in 2 cases each year. The other 11 cases were coagulase negative-staphylococci and thought to be contaminated during the sampling maneuver. The medical staff always should keep in mind to improve the patient outcomes by reducing catether-related infections. We must thus have appropriate knowledge and technical skills for catheter administration

Multi-cue 3D Object Recognition in Knowledge-based Vision-guided Humanoid Robot System

Abstract — A vision based object recognition subsystem on knowledge-based humanoid robot system is presented. Humanoid robot system for real world service application must integrate an object recognition subsystem and a motion planning subsystem in both mobility and manipulation tasks. These requirements involve the vision system capable of self-localization for navigation tasks and object recognition for manipulation tasks, while communicating with the motion planning subsystem. In this paper, we describe a design and implementation of knowledge based visual 3D object recognition system with multi-cue integration using particle filter technique. The particle filter provides very robust object recognition performance and knowledge based approach enables robot to perform both object localization and self localization with movable/fixed information. Since this object recognition subsystem share knowledge with a motion planning subsystem, we are able to generate vision-guided humanoid behaviors without considering visual processing functions. Finally, in order to demonstrate the generality of the system, we demonstrated several vision-based humanoid behavior experiments in a daily life environment. Fig. 1. system Behavior example of knowledge based vision guided humanoid I

Phylogeography of Infraspecific Differentiation of Hydrangea serrata (Hydrangeaceae), a Widespread Shrub Species in the Japanese Archipelago

departmental bulletin pape

Molecular Phylogenetic Analyses of Geographical and Ecological Speciation of Anaphalis margaritacea

departmental bulletin pape

Versatile Multilinked Aerial Robot with Tilting Propellers: Design, Modeling, Control and State Estimation for Autonomous Flight and Manipulation

Multilinked aerial robot is one of the state-of-the-art works in aerial robotics, which demonstrates the deformability benefiting both maneuvering and manipulation. However, the performance in outdoor physical world has not yet been evaluated because of the weakness in the controllability and the lack of the state estimation for autonomous flight. Thus we adopt tilting propellers to enhance the controllability. The related design, modeling and control method are developed in this work to enable the stable hovering and deformation. Furthermore, the state estimation which involves the time synchronization between sensors and the multilinked kinematics is also presented in this work to enable the fully autonomous flight in the outdoor environment. Various autonomous outdoor experiments, including the fast maneuvering for interception with target, object grasping for delivery, and blanket manipulation for firefighting are performed to evaluate the feasibility and versatility of the proposed robot platform. To the best of our knowledge, this is the first study for the multilinked aerial robot to achieve the fully autonomous flight and the manipulation task in outdoor environment. We also applied our platform in all challenges of the 2020 Mohammed Bin Zayed International Robotics Competition, and ranked third place in Challenge 1 and sixth place in Challenge 3 internationally, demonstrating the reliable flight performance in the fields

サクライソウ集団における近交弱勢による種子結実率の低下

サクライソウはサクライソウ科に属する小型の菌従属性植物である。この種は国内では数集団が現存するのみで，絶滅が危惧されている。本研究では，サクライソウの保全を考えるうえで，集団の存続に影響を及ぼすと考えられる近交弱勢を推定することを目的とし，岐阜県高山市のサクライソウの1集団において，人工交配実験を行い，近交弱勢による種子結実率の低下について調べた。自家交配を行った花では，他家交配を行った花よりも結実率が大きく低下した。これらのデータをもとに計算される，種子結実段階の近交弱勢はおおよそ0.4となった。近交弱勢は種子形成後にも現れると考えられるので，世代を通しての近交弱勢はさらに大きなものとなる可能性がある