Polyester is a synthetic material made from polyethylene terephthalate (PET), which is synthesised from fossil raw materials. Many clothing manufacturers are using polyester in their clothing, which, from an environmental perspective, creates a non-sustainable cycle. However, manufacturing can be made more sustainable by using recycled PET bottles as the raw material for polyester yarn. A clothing company that has taken a stand against materials made from fossil fibres and instead invests in only selling clothes made from sustainable materials is the Swedish children's clothing brand Polarn o. Pyret. Being able to use polyester made from PET bottles is important for Polarn o. Pyret to ensure the use of sustainable fibres in their clothing. In the past, the recycled polyester was used in combination with polyester from virgin fibre, but now the goal is instead to switch completely to the recycled polyester. However, the increased quantity of recycled polyester can involve new risks. The need to map potential contaminants is important because Polarn o. Pyret makes clothes for children, which entails strict requirements on the chemical content of the clothes. The purpose of this work is to get an overview of which contaminants that can accumulate in the polyester fibre and thus pose a risk when using recycled polyester made from PET bottles. The goal is to be able to shed light on these contaminants and write a proposal for a risk assessment guide that can establish a foundation for how Polarn o. Pyret should be able to act when using recycled polyester. The work was carried out through an extensive literature study, where research articles and review articles published on scientific databases were the main source of information. Focus was on the risk of non-intentionally added substances that can be traced from recycled PET bottles. The risk assessment was done in consideration of the regulations that is established within the European Union (EU), using the EU chemicals regulation REACH and the European Chemicals Agency (ECHA) database.  After the mapping of NIAS in r-PET, the literature showed 42 potential contaminants to be present. These substances originated from the degradation of PET or the degradation of additives, and impurities from the recycling process and post-consumption use. Adhesives, labels, and caps are a contributing factor to the formation of NIAS originating from the recycling process. Since PVC was found to be the most common plastic that could contaminate PET via recycling, the additives used in PVC could also migrate to PET and create impurities. The most common phthalate found in this study was DEHP, which was the main plasticiser in PVC.  15 substances of the NIAS found in the literature was CMR substances, which means that they either were, or were suspected to be, carcinogenic, mutagenic and/or toxic to reproduction. Among these were substances such as benzene, antimony, cadmium, lead, acetaldehyde, and formaldehyde. Certain substances found through the literature were classified to be endocrine disruptors. These NIAS were p-nonylphenol, the organophosphite TNPP, the phthalates DEHP, DBP, BBP and, DIBP, nickel and BPA. Some of the NIAS found were under assessment of being classified as persistent, bioaccumulativ and toxic (PBT). The PBT substances found were the organophosphite compound Irgafos 168 and the UV-stabilisers Tinuvin P, UV-234 and UV- 328. The risk assessment showed 20 contaminants that may cause irritation to the skin/eyes and/or throat and 24 contaminants which may be toxic to the aquatic life.  This risk assessment showed that the recycling process of PET bottles is not completely safe, because potential contaminants could be transferred into the polyester yarn, and then carried over into children's garment and pose health risks to children. / Polyester är ett syntetiskt material tillverkat av polyetentereftalat (PET), som är syntetiserat från fossila råvaror. Många klädtillverkare använder polyester i sina kläder vilket ur ett miljöperspektiv skapar ett ohållbart kretslopp. Tillverkningen kan dock göras mer hållbar genom att använda återvunna PET-flaskor som råvara för polyestergarn. Ett klädföretag som tagit ställning mot material tillverkade av fossila fibrer och i stället satsar på att endast sälja kläder av hållbara material är det svenska barnklädesmärket Polarn o. Pyret. Att kunna använda polyester tillverkad av PET-flaskor är viktigt för att Polarn o. Pyret ska kunna säkerställa användningen av hållbara fibrer i sina kläder. Tidigare användes den återvunna polyestern i kombination med polyester från jungfruliga råvaror, men nu är målet i stället att helt gå över till den återvunna polyestern. Den ökade mängden återvunnen polyester kan dock medföra nya risker. Behovet av att kartlägga potentiella föroreningar är också viktigt eftersom Polarn o. Pyrets gör kläder för barn, vilket medför hårda krav på klädernas kemikalieinnehåll. Syftet med detta arbete var att få en överblick över vilka kemikalier som kan ansamlas i polyesterfibern och därmed utgöra en risk vid användning av återvunnen polyester tillverkad av PET-flaskor. Målet var att identifiera dessa föroreningar och inkludera dessa ämnen i ett förslag till en riskbedömningsguide. Denna riskbedömningsguide skulle därmed kunna utgöra ett stöd för Polarn o. Pyret vid hantering av återvunnen polyester. Arbetet har utförts genom en omfattande litteraturstudie, där forskningsartiklar och översiktsartiklar publicerade på vetenskapliga databaser var den huvudsakliga informationskällan. Fokus låg på risken för oavsiktligt tillsatta ämnen som kan spåras från återvunna PET-flaskor. Riskbedömningen har gjorts med hänsyn till de regelverk som är etablerade inom Europeiska unionen (EU), med hjälp av EU:s kemikalieförordning REACH och europeiska kemikaliemyndighetens (ECHA) databas.  Efter kartläggningen av oavsiktligt tillsatta ämnen i återvunnen PET visade litteraturen att det fanns 42 potentiella kontaminanter. Dessa ämnen härrörde från nedbrytningen av PET eller nedbrytningen av tillsatser, samt från föroreningar kopplade till återvinningsprocessen. Lim, etiketter och korkar var en bidragande faktor till bildandet av de oavsiktligt tillsatta ämnen som härrörde från återvinningsprocessen. Eftersom PVC visade sig vara den vanligaste plasten som kunde kontaminera PET via återvinningen, kunde tillsatserna som används i PVC också migrera till PET och skapa föroreningar. Den vanligaste ftalaten som förekom i återvunnen PET i denna studie var DEHP, vilken är den huvudsakliga mjukgöraren i PVC.  15 oavsiktligt tillsatta ämnen konstaterades vara CMR-ämnen, vilket betyder att de var, eller misstänktes vara, cancerframkallande, mutagena och/eller reproduktionstoxiska. Bland dessa fanns ämnen som bensen, antimon, kadmium, bly, acetaldehyd och formaldehyd. Vissa ämnen som påträffades genom litteraturstudien klassificerades som hormonstörande. Dessa var p- nonylfenol, organofosfiten TNPP, ftalaterna DEHP, DBP, BBP och DIBP, nickel och BPA. En del av de ämnen som kartlades under riskbedömningen klassificerades som persistenta, bioackumulerande och toxiska (PBT). Bland dessa förekom organofosfitföreningen Irgafos 168 (Tris(2,4-ditert-butylfenyl)fosfit) och UV-stabilisatorerna Tinuvin P, UV-234 och UV-328. Riskbedömningen visade på 20 kontaminanter som kan orsaka irritation på hud/ögon och/eller svalg och 24 föroreningar som kan vara giftiga för vattenlivet.  Denna riskbedömning visade att återvinningsprocessen av PET-flaskor inte är helt säkert, eftersom potentiella kontaminanter kan inkluderas i polyestergarnet och därigenom skapa faror för barnen vid användningen av kläder tillverkade från återvunnen polyester.

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This thesis attempts to answer the questions "What purposes do family pets and the narratives we tell about them serve in modern American society?" and "What do these stories tell us about what Americans value and about where we locate our ‘value center’?" In Chapter 1, I discuss how Americans define loyalty in our pets now that our animals generally no longer help us work. I conclude that since the shift from agricultural to suburban settings, animals prove their loyalty individually and in human-like ways, rather than as "good" members of their own species, but at the same time because of their "animalness" they also provide us with a small but critical connection to nature. In Chapter 2, I explore how Americans experience spirituality or a "sixth sense" through our pets, especially our cats. These narratives show that many Americans are somehow able to hold diametrically opposed folk beliefs about exactly the same animal: while personal family stories about cats are almost uniformly positive and feature an angelic cat hero,impersonal folktales and legends still persistently characterize cats as evil and demonic. In Chapter 3, I look at how we work out our very American obsession with bigness through telling stories about our dogs. These stories allow us opportunities to talk about the socially inappropriate issue of male body size expectations, by celebrating big dogs and "under"dogs and by ridiculing those with "little dog complex."

Plasmid-encoded toxin (Pet) from enteroaggregative Escherichia coli is a member of the autotransporter subfamily termed SPATE (serine protease autotransporters of Enterobacteriaceae). Autotransporters, which are the most common Gram-negative secreted virulence factors, contain three functional domains: an amino terminal leader sequence, a mature protein or passenger domain, and a carboxy-terminal β domain. The leader sequence targets the protein to the periplasmic space and the β domain then forms a β-barrel pore in the outer membrane of the bacterium which allows the passenger domain to enter the external milieu. In some cases the passenger domain is cleaved from the β-barrel at the extracellular surface to release a soluble toxin. This is thought to be a self-contained process that does not require chaperones or ATP for folding and export of the passenger domain. Pet produces cytotoxic effects through cleavage of its target, the actin-binding protein α- fodrin. Pet is secreted into the extracellular environment, but its target lies within the cytosol. To reach its target, Pet moves from the cell surface to the ER where it triggers ER-associated degradation (ERAD) to enter the cytosol. ERAD is a normal cellular process in which improperly folded proteins are exported from the ER to the cytosol for degradation. Other toxins that utilize this pathway are AB toxins such as cholera toxin (CT) and ricin. The A subunits of these toxins are thermally unstable, and this facilitates their ERAD-dependent translocation into the cytosol. Pet, however, is not an AB toxin. We predict that thermal unfolding is not the mechanism Pet employs to exploit ERAD. It was necessary to purify the toxin first in order to study the structural properties and ER export of Pet. Surprisingly, purified Pet eluted as two close peaks by size exclusion chromatography. Both peaks were Pet as demonstrated through immunoblotting. The folding efficiency of autotransporters has not been extensively elucidated, and based on our purification results, we hypothesized that there is inefficiency in the folding of autotransporters, specifically Pet. A toxicity assay showed that Pet peak one did not display cytopathic activity while Pet peak two did. CD and fluorescence spectroscopy measurements also detected structural differences between the two variants of Pet and demonstrated that Pet peak one was an unfolded variant of Pet peak two. Native gel electrophoresis and biophysical measurements indicated that Pet peak one did not exist as a dimer or aggregate. Our results indicate there are two forms of Pet, and thus the folding process of autotransporters appears to be inherently inefficient. Active Pet (peak two) was used for further biophysical measurements and biochemical assays. Circular dichroism and fluorescence spectroscopy showed that the secondary and tertiary structures of Pet are maintained at physiological temperature, 37°C. Thermal unfolding of Pet occurred at temperatures above 50°C. Fluorescence quenching of Pet was also performed and demonstrated that, at 37°C, there are solvent-exposed aromatic amino acids. The slight structural alterations to Pet at physiological temperature as well as the exposed hydrophobic residues could trigger ERAD. In addition, a modeled structure of Pet revealed a hydrophobic loop which is surface-exposed and a likely target for toxin-ERAD interactions. The data suggests that translocation of Pet mediated by ERAD can occur by a mechanism different from certain AB toxins. An open, hydrophobic conformation likely triggers ERAD, but may also contribute to poor folding.

Identification of the pathways that could be targeted to alleviate ageing-related cognitive decline is of prime importance. One of the most promising target mechanisms is connected to healthy dopaminergic ageing. Extant research suggest that women may exhibit less ageing-related dopamine (DA) decline compared to men, implicating that women may suffer less from dopamine-related cognitive decline. However, to date, shortage of empirical investigations limit firm conclusions of sex differences. In the present work it is hypothesized that: (i) women as compared to men exhibit less aging-related DA losses, and (ii) less aging-related decline of episodic memory (EM), and that (iii) sex differences in episodic memory might be mediated by differences in DA integrity. To that end, sex-related differences in D1-type dopamine receptor (D1DR) integrity and episodic memory were investigated in a healthy cohort of young to old participants (age 20 – 80, n = 180, 50% women) through whole-brain voxel-wise analysis and linear regression models. Firstly, the dorsal caudate was identified as the main region of the EM-D1DR interrelation. Secondly, a significant female advantage was found for EM and D1DR in ageing. Finally, no mediation effect by D1DR on the sex-EM interaction was found. These results indicate the presence of correlational relationships between sex, cognition and D1DR, in ageing. However, D1DR was not found to be the mediating factor in the observed correlations. Future research, preferably using longitudinal design, should further investigate the underpinnings of sex differences in D1DR and EM.

The effect of various inorganic and organic additives as possible nucleating agents on the crystallisation behaviour of P. E. T. and the suosequent influence on the morphological and mechanical properties has been examined. Various methods of mixing(: the polymer and additive were investigated and a method involving the screw-Extrusion of the polymer and the additive was ultimately adopted. Crystallisation studies were carried out using differential scanning calorimetry under dynamic and isothermal modes. The results produced under conditions of isothermal crystallisation were analysed by means of a computer. Despite differences between batches of polymer all the additives with the exception of indigo produced a nucleating effect in the polymer as indicated by an increase in the rate of crystallisation compared with that of the base polymer. Two organo-metallic substances (sodium benzoate and sodium stearate) proved to be the most effective in this respect by decreasing the degree of supercooling of the polymer by 20 [degrees]. Morphological studies were carried out on isothermally crystallised samples, after etching and replication using a transmission electron microscope. A nodular structure whose dimensions were sensitive to both the nucleating agent and the temperature of crystallisation was observed. Mechanical testing of samples direct from the D. S. C. was carried out using a compression method. The breaking loads were found to vary with both the type of nucleating agent used and the crystallisation temperature chosen. A separate study involving the exanination of the resulting fracture surfaces by scanning electron microscopy revealed that a, high breaking load was associated with a fine discontinuous structure whereas lower breaking loads were characterised by a more continuous linear appearance. This implies a higher energy of fracture due to the increased surface area of the fracture surface of the former.

Globally, billions of tons of rubber and plastic waste are produced annually, and because these wastes degrade so slowly (about 450 years for plastic bottles and 80 years for tire rubbers), they are extremely difficult to dispose of. As a result, utilizing these wastes directly in building materials can significantly reduce the environmental load while also increasing the sustainability of the building material. This study compares the roles and effects of using recycled plastic and rubber as aggregates on the properties as well as the performance of concrete. This research focuses on sound insulation properties in particular. Each artificial polymer material of rubber and plastic has a special structure but consists of the same essential components. Plastic and rubber wastes, replacing fine/coarse aggregates are determined by their sort, size, replacement content, and shape. Plastic-based aggregates generally reduce the concrete's workability, but the impact of rubber-based aggregates is mostly influenced by their size and replacement amount. The main objective of this study is to review the evaluation of the sound insulating properties of concrete containing particles of plastic and rubber wastes based on their size, replacement amount, shape, and other factors. For the recycled PET, the results showed that the best percentage of recycled PET fibers mixed with ordinary concrete was in the range of 0.5 – 1.5% compared with other percentages. Low values in the range of 0.5 - 2%, especially 0.5%, of recycled PET mixed with concrete demonstrated the best value in terms of compressive strength compared with ordinary concrete. For the recycled rubber aggregate, the improved sound loss transmission for coarse crumb rubber was higher than the sound loss when using the same percentage of fine crumb. This could belong to that the coarse aggregate caused the voids to appear and increased the porosity in the system compared with the fine aggregate. When these aggregates were included the sound absorption can be improved drastically. The compressive strength of the samples containing fine crumbs of rubber was decreased compared to the control concrete sample without added rubber.   Many previous studies found a clear drop in compressive strength when using a fine rubber aggregate compared with coarse rubber aggregate. Generally, when adding a higher percentage of rubber, the sound absorption coefficient increased, while the compressive strength decreased.  Many researchers found that the thermal insulation increased when adding higher percentages of plastic and rubber waste to concrete. The degree of thermal insulation improvement for mixing concrete with plastic and rubber is also determined by the shape of the pieces. The density of concrete decreased as the percentage of plastic and rubber particles in the mixture increased.

京都大学 / 新制・論文博士 / 博士(医学) / 乙第13570号 / 論医博第2296号 / 新制||医||1069(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 花川 隆, 教授 渡邉 大, 教授 高橋 淳 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

In this study, we attempt to test whether more mechanics cause players to become more attached to a simulated pet over time. In order to find this out, we created a pet simulator game, split it into four versions with different levels of interaction for the player, going from no interaction to three discrete interactions. We had four groups of participants play the game for five consecutive days. In concert with this, the participants answered several surveys. The first was to establish their baseline attachment to the simulated pet and was delivered at the start of the study. The second and third were delivered at the end of the study, the second survey to characterise their attachment style and the third was a repeat of the first survey, allowing us to see what, if anything, had changed in their relationship to the simulated pet. Finally, we conducted semi-structured interviews with some participants whose responses were outlier or otherwise interesting. Our findings suggested loosely that the more interactions, the more likely a player forms an attachment but also that no interactions causes attachment to degrade over time.

著作権情報を一部追加（2023-06-30） / 京都大学 / 新制・論文博士 / 博士(農学) / 乙第13508号 / 論農博第2906号 / 新制||農||1095(附属図書館) / 学位論文||R4||N5408(農学部図書室) / (主査)教授 谷 史人, 教授 入江 一浩, 教授 井上 和生 / 学位規則第4条第2項該当 / Doctor of Agricultural Science / Kyoto University / DFAM