This collection of short stories takes its name from various islands historically believed to exist and at one time or other located on maps, sometimes remaining on them for centuries, but later removed after they were proved to be illusory. Reports of these islands usually came from sailors as they explored new realms, mistaking actual islands for imaginary ones or by geographical error. Illusions can persist unchallenged for ages. A similar yet modern illusion is the persistence of vision, a phenomenon by which an afterimage, say, on a screen, is thought to persist on the retina for approximately one twenty-fifth of a second. The characters in these stories live their isolated lives as after-image phantoms on islands that either never existed or no longer exist.

European whitefish (Coregonus lavaretus) forms reproductively isolated sub-populations with different body sizes in the lakes where northern pike (Esox lucius) exists. It has been hypothesized that the initial reproductive isolation between ecotypes arises through size-assortative mate choice or because small and large individuals arrive to the spawning grounds at different times. To test these hypotheses, I caught and measured both breeding whitefish pairs and singular whitefish on the spawning grounds over the spawning season. There was no correlation between the lengths of males and females in breeding pairs, indicating that mate selection was random with respect to body size. There were no significant differences in body length between sampling dates during the field period in November 2021, suggesting that there is no divergence in spawning time between large and small individuals. Thus, neither of the two hypotheses were supported. Interestingly, males have significantly higher amount of breeding tubercles than females according to my results, which could be a selective factor in mate selection. However, the function of the tubercles is yet poorly understood.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第21000号 / 医博第4346号 / 新制||医||1027(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 岩井 一宏, 教授 中川 一路, 教授 伊達 洋至 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

No description available.

Linamarase application exists in biotechnology such as potentiometric sensors for linamarin by coupling linamarase from cassava leaf with a cyanide ion-selective electrode and to measure glucose in biomedical applications. It is used in a batchwise process to detoxify fermenting cassava during ‘garri’ production. Linamarase along with its naturally occurring substrates, linamarin and lotaustralin, is found in a variety of edible plant tissues such as those of cassava from which garri is produced. However, the separation and purification of linamarase at reasonable large quantity for these applications from plants has been a challenge. In the study a miniflex Ultrafiltration (UF) Cross Flow obtained from Schleicher and Schuell (Germany) was used for linamarase isolation and purification from cassava tissues. Membranes with different pore sizes of 0.45, 0.2, 0.1 and 0.02 μm, made from polyethersulfon screnes and silicone adhensives, with surface area of 2.4 mm2, were experimented. Fluxes were observed to decrease very sharply from 0.45 to 0.02μm membrane pore sizes. No permeate was collected from 0.1 and 0.02 μm membranes due to concentration polarisation and clogging of these membranes. Permeate and retentate from 0.45 and 0.2 μm membrane contained linamarase, while the retentate of the 0.1 and 0.02 μm membranes contained linamarse and that no permeate was collected from 0.1 and 0.02 μm membranes due to the fouling and clogging of the small membrane pores. It was therefore concluded that linamarase was finally purified by the 0.2 μm membrane. A simple mathematical model derived from the Hagen-Poiseuille equation could not predict the linamarase flux data, perhaps due to the effect of concentration polarisation, which led to the proposition of the Langmuir adsorption isotherm. It was interesting to observe that the plot of 1/v versus 1/Δp from the use of the Langmuir equation gave a linear relationship from which the linamarase flux iii was predicted. The standard error between the experiment and the model was 0.011, which is a good measure of the agreement between data. The Langmuir adsorption isotherm therefore predicts the fouling and concentration polarisation of the membrane during linamarase purification from cassava tissues. This proposition was supported by the solute deposits on the pores and surface of the membrane where van der Waal forces were created between the molecules, thus resulting in the fouling and chemical polarisation.

Social isolation during adolescence can have long lasting negative effects in both humans and animal models. In mice, post-weaning social isolation leads to increased addiction-like behaviors in adulthood. However, little is known about how post-weaning social isolation alters the brain. Stress during development can lead to persistent restructuring of neurons. Changes in dendritic spines can be long-lasting and have been theorized to play an important role in the maintenance of cocaine craving. We found that post-weaning isolation led to a persistent increase in spine density in adulthood within both the core and shell regions of the nucleus accumbens in male mice, but not female mice. In contrast, in the infralimbic cortex, post-weaning social isolation led to an increase in spine density only in female mice. This study highlights the long-lasting, sex-specific effects of post-weaning isolation. Microglia have been shown to assist in both the formation and elimination of dendritic spines, and are activated following exposure to stress and cocaine. Therefore, we hypothesized that microglia may be involved in the restructuring of dendritic spines during post-weaning isolation, and contribute to addiction-like behavior in adulthood. We examined whether inhibiting microglia with minocycline during the first three weeks of post-weaning isolation altered the impact of isolation in cocaine seeking. Isolated animals that received minocycline showed increased cocaine seeking in adulthood compared to group housed mice and isolated mice that received saline. Minocycline and isolation also caused sex-specific alterations in spine density. The findings of these studies provide insight into the mechanisms by which social isolation during adolescence increases vulnerability to addiction later in life. / Psychology

No description available.

According to the United Nations, by the year of 2050, 16% ofthe world’s population will be over the age of 65, that is one in six people.¹ Considering this, there is more need than ever to bridge the generation gap. Prior research on the theme of different kinds of domestic efficiency, led me to a comparative study between mass produced housing and collective living. I spoke in favour of the values of social sustainability at the price of economically superior construction methods. Departing then from the subject of social isolation and involuntary loneliness versus togetherness, I landed on the topic of elderly care and intergenerational interdependence. This paper proposes the need of intergenerational housing and therefore my method for approaching this theme is through designing a combined elderly care home, student housing and preschool. My findings suggest that the environment which surrounds us impacts us in a number of ways, as does the ambiance, the people, and the relationships we have with them. Therefore, I aim to create a space with a warm and familiar feel as opposed to an impersonal and institutional one and a place where relationships between different age groups can naturally blossom.

京都大学 / 新制・課程博士 / 博士(理学) / 甲第24457号 / 理博第4956号 / 新制||理||1707(附属図書館) / 京都大学大学院理学研究科生物科学専攻 / (主査)准教授 中野 隆文, 教授 本川 雅治, 教授 森 哲 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

Indiana University-Purdue University Indianapolis (IUPUI) / This study examined effects of ostracism on psychological well-being and self-control and the roles of the personality traits hope, optimism, and forgiveness as moderators of these effects. Undergraduate students (N=104) were randomly assigned to be included or excluded in a computerized ball-toss game, Cyberball. Facets of psychological well-being examined included belonging and self-esteem. Participants also completed cognitive and physical self-control measures via tracing and handgrip tasks. Ostracized participants experienced less belonging, but there was no significant difference between groups on self-esteem. Ostracized participants persisted for less time on the tracing task. There were no significant differences between groups for performance on the handgrip task. None of the personality traits were found to moderate the effects of ostracism on psychological well-being or self-control. Results are discussed in terms of implications and recommendations for future researchers.