INVESTIGATION OF THE ROLES OF ASF1 AND CAF-1-MEDIATED CHROMATIN ASSEMBLY IN THE HUMAN DNA DAMAGE RESPONSE

The access-repair-restore model for the role of chromatin in DNA repair infers that chromatin is a mere obstacle to DNA repair. However, here we show that blocking chromatin assembly of newly-synthesized histones, via knockdown of the histone chaperones ASF1A, CAF-1 or a mutation that specifically prevents ASF1 binding to histones, hinders loading of Rad51 onto ssDNA during homologous recombination, as a consequence of reduced recruitment of the Rad51 loader MMS22L/TONSL to ssDNA, resulting in persistent RPA foci, extensive DNA end-resection, and persistent activation of the ATR-Chk1 pathway. By contrast, ASF1 and CAF-1 render the rapid inactivation of ATM Chk2 pathway via facilitating histone acetylation to allow the recruitment of ATM to DSBs for efficient repair by non homologous end joining. Furthermore, in response to DSB damage, ASF1A is specifically phosphorylated by DNA-PKcs and potentially other kinases, enhancing its interaction with histones H3.1/H4 and CAF-1, and promoting the recruitment of MMS22L/TONSL to the damaged DNA to form the Rad51 nucleofilament during homologous recombination. We propose a model whereby DSB-induced phosphorylation of ASF1A promotes transient assembly of newly-synthesized histones onto single-stranded resected DNA, which serves to recruit TONSL-MMS22L to efficiently form the Rad51 vii nucleofilament for strand invasion. As such, we have uncovered an unexpected role for chromatin assembly in an intermediate stage of homologous recombination, revealing that chromatin assembly plays an active role in DNA repair per se

Frictional analysis of cam-controlled planetary gear trains

This study aims to carry out the frictional analysis of cam-controlled planetary gear trains through an illustrative example. First, the equations for frictional analysis proposed in the previous study are presented. Then, the results of friction force and couples are obtained by numerical analysis. The results indicate that a cam-controlled planetary gear train is of high mechanical efficiency, but will induce significant vibration

Cross Talk among Phytohormone Signal and Carbohydrate Metabolism Involving Regenerable Calli Induction under Osmotic Treatment

Nonregenerable calli (NRC) derived from immature seeds of japonica rice were inoculated on MS medium containing 10 μM 2,4-D (MSD10). They turned to highly regenerable calli (HRC) when sorbitol was supplemented into the medium. Meanwhile, high levels of endogenous IAA and ABA were accumulated in HRC. Exogenous IAA precursor and ABA in MSD10 have the same effect to enhance regeneration ability. However, there are only partial effects if IAA precursor or ABA was supplemented, respectively. The regeneration ability is prominently decreased from 75% to 25% while an auxin transport inhibitor, 2,3,5-triiodobenzoic acid, was included in the medium. It suggested that endogenous auxin signal and ABA may involve in the induction of HRC. Furthermore, it showed higher contents of glucose, sucrose, and starch and higher expression levels of wall-bound invertase 1, sucrose transporter 1 (OsSUT1), and OsSUT2 genes in HRC than in NRC. The expression levels of PIN-formed 1 and LEA1 were also consistent with the trend of carbohydrate metabolisms. We thus concluded a flowchart for HRC induction by osmotic stress. According to the hypothesis, osmotic stress may regulate endogenous levels of auxin interacting with ABA, then affect carbohydrate metabolism to trigger callus initiation and further shoot regeneration in rice

Limited-edition advertising does not always work for luxury brands: The influence of consumption contexts

Limited-edition advertising on a limited quantity available to be sold (LQS, limited quantity scarcity) is used to increase product value, thereby enticing consumers. This type of limited-edition advertising has been proven to be effective for luxury brands; as a result, its adoption has increased over the years. However, are limited editions effective across all consumption situations? The current study argues that limited-edition advertising may not always work as well as previously thought and that it is only effective when (1) consumers are in emotional (versus cognitive) consumption contexts, (2) the consumption is socially visible (versus invisible), and (3) the country of origin where the luxury product was made is favourable (versus unfavourable). The results of two experiments using 807 participants confirmed the study’s hypotheses. More importantly, the findings showed that limited-edition advertising had detrimental effects in a cognitive consumption context; that is, using limited-edition advertising in a cognitive consumption context decreased consumers’ purchase intentions. Theoretical and managerial implications are discussed

麹菌Aspergillus oryzaeにおけるストレス顆粒に関する研究

学位の種別:課程博士University of Tokyo(東京大学

Small-Size Humanoid Soccer Robot Design for FIRA HuroSot

Non

Dengue Vector Surveillance and Control in Taiwan

In view of possible dengue outbreak due to the rapid development of national tourism to Southeast Asia, the long-neglected Aedes surveillance was resumed since July 1987. After the dengue outbreak was detected in November 1987, the surveillance was greatly intensified, and house mosquitoes were collected for virus isolation. Nine isolates of dengue type one virus were obtained from the female mosquitoes of Aedes aegypti among the 9 species of mosquitoes collected in houses in 1987 and 1988. Health education of the public was enforced by propaganda through newspapers, broadcastings, televisions and public lectures etc. Although the outbreak could be kept under control fairly successfully, the results of Aedes surveys reveal that the achievement in source reduction of Aedes breeding has so far been unsatisfactory. Aedes larval density per 100 houses showed only very gradual lowering each year from 3,010 in 1987 to 1,900, 1,015, 1,373, 604, 570 and 218. Since Ae. aegypti is considered playing an important role in the present outbreak, in 1991 and 1992 residual spray of alphacypermethrin was applied to the interior walls of houses in the area with Breteau index of above 35 for Ae. aegypti. Undoubtedly it contributed much in suppressing the outbreak in recent years

INVITATION: An Elderly Friendly ICT-enabled Interactive Installation to Promote Social Participations

Many countries are facing significant challenges posed by aging populations, and many of these elderly people are increasingly socially isolated, raising the need to develop senior-friendly services and settings for community life. ICT-enabled technologies can be used to help the elderly maintain adequate degrees of social participation. This paper reports the design and production of an innovative recreation installation featuring elderly friendly technologies to enhance the social lives of elderly Chinese people. The contents are composed of modernized visualization elements of traditional Chinese painting designed to engage elderly Chinese people and promote interaction and participation.</p

A comparison of the learning effects between TGfU-SE and TGfU on learning motivation, sport enjoyment, responsibility, and game performance in physical education

BackgroundBoth the Sport Education (SE) model and Teaching Games for Understanding (TGfU) have been connected to the theory of situated learning, which is a game-centered curricular model. TGfU emphasizes tactical awareness, decision making, and skill execution. The SE model provides a complete season during physical education (PE) lessons. Therefore, it is worth exploring the integration of TGfU with SE (TGfU-SE) model in PE courses, and whether the hybrid TGfU-SE model can achieve better learning effects for students than the TGfU model alone.PurposeThe purpose of the study was to compare the difference in learning effects between the TGfU-SE model and the TGfU model on students’ learning motivation, sport enjoyment, responsibility, and game performance.MethodsThis study used a quasi-experimental design to compare different learning effects between the experimental group (TGfU-SE) and the control group (TGfU). The participants lived in Taiwan, including two junior high school PE teachers and four PE classes with a total of 90 students (TGfU-SE group, n = 46; TGfU group, n = 44). Each teacher taught two PE classes, one with an experimental group and one with a control group. This study used four research instruments, including the Responsibility Scale in Physical Education (RSPE), Learning Motivation Scale in Physical Education (LMSPE), Sport Enjoyment Scale in Physical Education (SESPE), and Game Performance assessment instrument (GPAI). Analysis of covariance (ANCOVA) and the independent t-test were used to analyze the data.ResultsThe results of this study showed that the TGfU-SE model had more positive learning effects on students’ learning motivation, sport enjoyment, responsibility, and game performance than the TGfU model.Conclusionwe concluded that the TGfU-SE model had a more positive influence on students’ learning performance than the TGfU model. It is suggested that the hybrid TGfU-SE model could be implemented effectively in the PE curriculum