98 research outputs found

    Advanced glycation end products and age-related diseases in the general population

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    In this thesis, epidemiological, nutritional, and gut microbiome related studies are presented to illustrate the relation of advanced glycation end products (AGEs) with age-related diseases. The studies are embedded in the Rotterdam Study, a cohort of the Dutch general population of middle-aged and elderly adults. The amount of skin AGEs measured as SAF was used as a representative of the long-term AGE burden. Chapter 1 gives an overview of the whole thesis (Section 1.1) and gives a brief introduction to AGEs and their implications in disease pathophysiology. Chapter 2 focuses on the interplay of AGEs in the skin and clinical and lifestyle factors, and Chapter 3 concerns the link of skin and dietary AGEs with age-related diseases. Chapter 4 discusses the interpretations and implications of the findings, major methodological considerations, and pressing questions for future research

    Advanced glycation end products and age-related diseases in the general population

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    In this thesis, epidemiological, nutritional, and gut microbiome related studies are presented to illustrate the relation of advanced glycation end products (AGEs) with age-related diseases. The studies are embedded in the Rotterdam Study, a cohort of the Dutch general population of middle-aged and elderly adults. The amount of skin AGEs measured as SAF was used as a representative of the long-term AGE burden. Chapter 1 gives an overview of the whole thesis (Section 1.1) and gives a brief introduction to AGEs and their implications in disease pathophysiology. Chapter 2 focuses on the interplay of AGEs in the skin and clinical and lifestyle factors, and Chapter 3 concerns the link of skin and dietary AGEs with age-related diseases. Chapter 4 discusses the interpretations and implications of the findings, major methodological considerations, and pressing questions for future research

    New Polymer and Composite Structures for Photonic Applications

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    The focus of this thesis is the development of materials and architectures for all-polymer functional structures for photonic applications. The first part concerns the improvement and optimization of colorimetric and fluorescent sensing structures for the detection of various analytes in the vapor phase. Optical-readout sensors are portable and can provide an easy interpretation that needs no specialized training and can be visible to the naked eye. This makes them promising for applications in environmental control, health monitoring and food safety. The objective of the work was to investigate analyte diffusion processes into multilayered structures of polymer submicrometric films, and then optimizing the structure design and expanding the materials used in the field. First, sensors based on vapor diffusion in multilayered polymer dielectric mirrors with structural coloring were developed. Given their clear color change, this typology of sensors has been shown to be promising in the literature. However, as their response is limited by the diffusion speed of molecular species, they can suffer from slow detection of vapor-phase analytes. Next, I examine the use of fluorescent polymer films sensitive to microviscosity changes caused by exposure to volatile organic compounds and observing the changes in fluorescence during said exposure. The effect on the overall diffusion of capping layers deposited on top of the fluorescent polymer was investigated to quantify the effect of the barrier polymer on the selectivity of the sensor. Finally, I employed the solution processing protocols developed for novel low refractive index polymer suspensions that were initially utilized for the sensors to engineer structures for fluorescence control. When two highly reflecting structures encapsulate a luminescent material in a submicrometric space, this changes the photoluminescence properties in structures called optical microcavities. While the highly reflecting structures can be metallic mirrors, these have limited reflectance intensity, high absorbance losses, as well as a lack of tunability. Instead, the use of dielectric mirrors enables very high reflectance at desired wavelengths. In addition, the use of compliant polymer materials allows the future use of these structures to construct more efficient flexible devices. I was able to develop highly reflecting microcavities for emitters in the visible range as well as in the near infrared. Besides achieving high amplification of fluorescence intensity, I was also able to report for the first time a change in the radiative rate of the fluorescence for polymer structures. As these effects were so far only observed in planar structures of inorganic nature or more complex polymer three-dimensional systems, this presents a breakthrough in the field. In this introduction I will give a wide but deep overview of the optics of multilayered polymer films, their diffusion peculiarities, and use for sensing. Furthermore, I will address the topic of solid-state organic fluorophores and controlling their photoluminescence through engineering the dielectric environment. This will be followed by a chapter-by-chapter exploration of the results obtained during the doctoral training as adapted from already published or drafted work. Finally, the outlook and possible future implications and developments of this research will be examined

    The Politics of Racial Translation : Negotiating Foreignness and Authenticity in Russophone Intersectional Feminism and Timati's Hip-hop (2012-2018)

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    Hva skjer med rase-, kjĂžnns- og seksualitetspolitikk i interseksjonell feminisme og hiphop nĂ„r de forflytter seg Ăžstover til postsovjetiske, russisksprĂ„klige kontekster? Denne avhandlingen utforsker oversettelsens betydning i sirkulasjonen av det amerikanske, engelsksprĂ„klige idiomet ‘rase som motstand’ i russisksprĂ„klige tilpasninger av hiphop og interseksjonalitet i perioden 2012-2018. Ved hjelp av digital etnografi, diskursanalyse og nĂŠrlesing av et utvalg musikkvideoer, analyseres to oversettelsesprosjekter empirisk: en russisksprĂ„klig grasrotside for interseksjonell feminisme, FIO (Feminist Intersectionality Against Oppression), og den – i Russland kontroversielle – tatarisk-jĂždiske hiphop-entreprenĂžren Timati. Denne avhandlingen, som befinner seg i skjĂŠringspunktet mellom kjĂžnns- og seksualitetsstudier, rase- og etnisitetsforskning og postsovjetiske kulturstudier, framhever oversettelse bĂ„de i sitt teoretiske rammeverk og i metodologisk forskningsdesign. Teoretisk er avhandlingens tilnĂŠrming til oversettelse inspirert av feministisk teori, feministisk antropologi og oversettelsesstudier, samt av transnasjonale perspektiver pĂ„ rasialisering og den voksende forskningen pĂ„ rase i Russland. Metodologisk trekker avhandlingen pĂ„ verktĂžy fra oversettelsesstudier og sosiolingvistikk. Ved Ă„ begrepsligjĂžre oversettelse som en forutsetning for geografisk forflytning av ideer, som et sted for forhandling der ting produseres som ‘fremmede’, og som en generativ snarere enn imiterende prosess, spĂžr den hva raseoversettelse frambringer og hvorfor noen oversettelsesprosjekter framstilles som mer fremmede enn andre. Metoden er Ă„ spore hvordan fremmedhet tilskrives ulike objekter, samt Ă„ undersĂžke de oversettelsesstrategiene som brukes i de to nevnte empiriske tilfellene nĂ„r de gjengir engelsksprĂ„klige rasekategorier som ‘white’, ‘black’, ‘people of color’ og ‘women of color’. I tillegg til Ă„ undersĂžke hvilke generative effekter oversettelsene har, bruker studien en multimodal tilnĂŠrming som overskrider de semantiske grensene til etnorasekategorier og muliggjĂžr utforsking av rasemessig oversettelse pĂ„ tvers av flere semiotiske moduser. Avhandlingen begrepsligjĂžr rasemessig oversettelse som gjennomsyret av kjĂžnns- og seksualitetsdynamikk, innebygd i geopolitiske konfrontasjoner og informert av russisk imperial arv, og argumenterer for at rasemessig oversettelse er generativ pĂ„ flere sentrale mĂ„ter. Den rasemessige oversettelsen skaper nye og moderne formsprĂ„k (russofon interseksjonell feminisme og russisk kommersiell hiphop), kronotopisk plasserte former for personlighet knyttet til bestemte oversettelsesstrategier eller motstand mot dem, samt affektive responser og bestridelser av oversettelsesvalg og oversettelsesprosjekter som stigmatiseres eller verdsettes som ‘fremmede’. De som oversetter, tilnĂŠrmer seg det engelsksprĂ„klige formsprĂ„ket ‘rase som motstand’ som ‘fremmed og moderne’, og indekserer en avansert tid og et avansert sted, USA, for Ă„ styrke, reparere og modernisere russisksprĂ„klig feminisme og russiske musikkscener. Begge oversettelsesprosjektene posisjonerer fremmedgjĂžring som en kilde til modernisering, noe som forklarer predisposisjonen for fremmedgjĂžrende oversettelsesstrategier. FremmedgjĂžrende oversettelsesstrategier og motviljen mot bokstavtrohet i postsovjetiske, russisksprĂ„klige kontekster, kan imidlertid gjĂžre oversetterne selv fremmede, noe som fremmer jakten pĂ„ originalitet, forsĂžk pĂ„ Ă„ forhandle oversettelsens stigma og Ă„ reparere kronisk inautentisitet. PĂ„ nettsidene til det russisksprĂ„klige, interseksjonelle feministiske digitale fellesskapet, skaper moderatorenes tilbĂžyelighet til translitterasjoner en form for uro, beskyldninger om uforstĂ„elighet og en slags motvilje for sprĂ„kblanding. Moderatorenes rolle som en kosmopolitisk, tosprĂ„klig, feministisk elite skiller seg fra vanlige russisksprĂ„klige lesere. Interseksjonalitet sirkulerer som en feministisk kronotop, som FIO ser for seg som en feministisk fremtid, et botemiddel mot den russisksprĂ„klige feminismens rasisme, homofobi og transfobi. Feministiske kronotoper blir brukt i diskusjoner rundt oversettelse og blant annet utnyttet i lokale kronotopiske forestillinger om russisk bakstreverskhet og slavofil trangsynthet. Den bokstavelige oversettelsen av kategorien ‘hvit’ genererer figurer som ‘hvit mann’ og ‘hvite kvinner’ og inngĂ„r i det russisksprĂ„klige interseksjonelle feministiske formsprĂ„ket. Produksjonen av modererende antirasistisk hvithet-i-oversettelse mobiliserer kronotopiske figurer av tilbakestĂ„ende rasistiske andre som komparativ kontrast til mer moderne kunnskap. Den driver ogsĂ„ frem spĂžrsmĂ„l om grensene for oversettbarheten til kategorien ‘hvit’ for den situerte antirasistiske post-sovjetiske praksisen i kommentartrĂ„dene, inkludert den skiftende kategorien КаĐČĐșазцы/Kaukasiere. Manglende oversettelse av kategoriene ‘people of color’ og ‘women of color’ genererer blant annet sĂžken etter en postsovjetisk ‘woman of color’ som et russisksprĂ„klig interseksjonelt feministisk subjekt. Slik kanoniseres “rĂ„â€ oversettelse, den transsprĂ„klige spredningen av etno-rasistiske kategorier og instrumentaliseringen av figuren ‘trans woman of color’ av russisksprĂ„klige radfem som et tegn pĂ„ den russisksprĂ„klige interseksjonalitetens totale fremmedhet. Begrepet realia brukes i materialet som en sĂžken etter Ă„ lokalisere det amerikanske raseidiomet og for Ă„ belyse sĂŠrtrekkene ved den post-sovjetiske etnorasiske maktdynamikken. I undersĂžkelsen av raseoversettelse i Timatis hiphop, vises det hvordan Timati, ved Ă„ kombinere amerikansk svart hiphop-estetikk med russisk glamour pĂ„ 2000-tallet, brukte uoversatt amerikansk svarthet som en kosmopolitisk kulturell kapital for Ă„ motvirke volden i den post-sovjetiske rasialiseringen. Ved Ă„ nĂŠrme seg amerikansk svart estetikk gjennom direkte erfaring med ‘kilden’, fikk Timati transnasjonal suksess med sin etnorasiale formbarhet og evne til Ă„ formidle mellom postsovjetiske markeder, lokale Ăžkonomiske eliter, amerikansk raseautentisitet og amerikanske hiphop-kjendiser. Han bidro derimot neppe til Ă„ avhjelpe hiphopens kroniske inautentisitet i Russland. ForsĂžk pĂ„ Ă„ hĂ„ndtere stigmaet fremmedhet og imitasjon, og Ă„ oppnĂ„ sterkere hiphop-autentisitet pĂ„ hjemmebane, markerte en reorientering av Timatis prosjekt for rasemessig oversettelse. Fra 2012-2013 figurerer Kaukasus og kaukasiske maskuliniteter som ‘regionale originaler’, noe som gjĂžr det mulig for Timati Ă„ oversette den amerikanske svarte maskuliniteten som ligger til grunn for amerikansk hiphop-autentisitet. Han tar i bruk ulike strategier, som ‘vikarierende autentisitet’, memetikk og hiphop-homofobi, og skaper en homofobisk hiphop-meykhana-cipher og visuelle, imperiale troper av et kaukasisk sublim. Skjegget som rasemessig/seksuell metonymi er sentralt for Ă„ forstĂ„ Timatis prosjekt for rasemessig oversettelse i 2014-2015, som er involvert i seksuell geopolitikk mellom Ăžst og vest. Gjennom hiphop-modernitet og tvillingfantasien om etnisk raseblanding og sentralasiatiske migranters Ăžkonomiske oppsving i Russland, oppvurderes den etniske andre fra Ă„ vĂŠre symbol pĂ„ en sikkerhetstrussel (skjeggete terrorister) til Ă„ bli moderne, homofob og kul – og slik i stand til Ă„ sikre Russlands organiske og multinasjonale fremtid mot et angivelig korrupt og seksuelt perverst Europa. HĂžydepunktet i Timatis prosjekt for rasemessig oversettelse i 2014-2016 resulterte i oppfinnelsen av en bevisst memetisk karakter, Teymuraz, som iscenesetter rasistiske klisjeer av kaukasiske og sentralasiatiske menn. Teymuraz, som en del av Russlands hybridkulturelle trend med estetisk populisme, resirkulerer elementer fra New East gopnik-stil, sovjetiske og postsovjetiske komedier om menn fra Kaukasus og Sentral-Asia, blander elementer av samfunnskritikk og tilegner seg de subalternes stemmer. Han utgjĂžr med dette et sĂŠregent patriotisk, antirasistisk prosjekt med motstridende implikasjoner. Timatis lekne fremfĂžringer av patriotisme og performativ disidentifikasjon fra USA som kilde til hiphop i 2015 forstĂ„r hiphop-patriotisme som en strategi for Ă„ lokalisere hiphop i den skiftende geopolitiske konteksten av Russlands vending bort fra Vesten. Russiske diskurser om hiphop-autentisitet, som er opptatt av Ă„ oppdage og avslĂžre plagiat i Timatis arbeid, gir stemme til et sĂŠregent arbeid med Ă„ skille ‘ekte’ hiphop fra ‘falsk’ hiphop. Dette arbeidet bygger pĂ„ rasistiske diskurser om handel og umoral, og markerer Timati som ‘fremmed’ - bĂ„de utenfor sjangerens og den russiske nasjonens grenser – og avslĂžrer en russisk etnonasjonal skjevhet som ligger til grunn for russiske diskurser om hiphop-autentisitet. NĂžkkelord: oversettelse, interseksjonalitet, rase, etnorasisk, postsovjetisk, russisk hiphop, rap, russisk rap, grasrotfeminisme, digital feminisme, feministiske kronotoper, feministisk oversettelse, feministisk aktivisme, populĂŠrmusikk, Russland, russofon, oversettelsesstrategier, litteralisme, translitterasjon, homofobi, transfobi, vikarierende autentisitet, memetikk, realia, rasemessig/seksuell metonymi, indeksikalitet, multimodalitet, den kalde krigen, russisk populĂŠrkultur, digital aktivisme, autentisitet, hiphop-maskuliniteter, rasialisering, Kaukasus, Sentral-Asia.What happens to race, gender, and sexuality politics of intersectional feminism and hip-hop when they travel eastwards into post-Soviet Russophone contexts? This thesis explores the role of translation in the circulations of the US Anglophone idiom ‘race as resistance’ in 2012-2018 Russophone adaptations of hip-hop and intersectionality. Drawing on the digital ethnography, discourse analysis, and close reading of a selection of music videos, it empirically analyzes two translation projects: a grassroots Russophone translation-based intersectional feminist page, FIO (Feminist Intersectionality Against Oppression) and – a controversial in Russia – Tatar-Jewish hip-hop entrepreneur, Timati. This thesis, situated at the intersection of gender and sexuality studies, race and ethnicity research, and post-Soviet cultural studies, foregrounds translation in its theoretical framework and methodological research design. Theoretically, the dissertation’s approach to translation is inspired by feminist theory, feminist anthropology, and translation studies, as well as by transnational perspectives on racialization and the growing scholarship on race in Russia. Methodologically it draws on the tools from translation studies and sociolinguistics. Conceptualizing translation as a precondition for travel, as a site of negotiation where things are produced as ‘foreign’ and as a generative rather than imitative process, this thesis asks what racial translation generates and why some translation projects are rendered as more foreign than others. The method is to track the attributions of foreignness and examine the translation strategies used by the two projects mentioned above when rendering English-language racial categories such as ‘white,’ ‘black,’ ‘people of color,’ and ‘women of color.’ The study also uses the multimodal approach that goes beyond the limits of the semantics of ethnoracial categories, allowing for the exploration of racial translation across multiple semiotic modes. Conceptualizing racial translation as saturated in gender and sexuality dynamics, embedded in geopolitical confrontations, and informed by Russian imperial legacies, the thesis argues that racial translation is generative in several central ways. It creates novel and modern idioms (Russophone intersectional feminism and Russian commercial hip-hop), chronotopically positioned types of personhood associated with particular translation strategies or resistance to them, as well as affective responses and contestations of translation choices and translation projects stigmatized or valorized as ‘foreign.’ The translators approach the Anglophone idiom of ‘race as resistance’ as ‘foreign and modern,’ indexing advanced time and place, the USA, brought up to invigorate, repair, and modernize Russophone feminisms and Russian music scenes. Both translation projects position foreignization as a source of modernization, explaining the predisposition for foreignizing translation strategies. However, foreignizing translation strategies and the aversion to literalism within post-Soviet Russophone contexts may render translators themselves foreign, propelling the search for originality, the attempts to negotiate the stigma of translation, and to repair chronic inauthenticity. On the pages of the Russophone intersectional feminist community, the moderators’ predisposition to transliterations generates visceral unease, accusations of unintelligibility, anxieties about the language mixing, and the roles of moderators as cosmopolitan bilingual feminist elites different from ordinary Russophone readers. Intersectionality circulates as a feminist chronotope, envisioned by FIO as a feminist future, a remedy against exclusions within Russophone feminisms such as racism, homophobia, and transphobia. Circulating feminist chronotopes are used in contestations around translation, harnessed on local chronotopic imaginaries such as Russian peasant backwardness and Slavophile parochialism. The literal translation of the category ‘white’ generates figures such as ‘white man’ and ‘white women,’ which enter the Russophone intersectional feminist idiom. The production of anti-racist whiteness-in-translation mobilizes chronotopic figures of backward racist others in comparative contrast with more modern bodies of knowledge and types of personhood. It also propels the questioning of the limits of the translatability of the category ‘white’ for the situated anti-racist post-Soviet praxis in the comment threads, including the shifting category КаĐČĐșазцы/Caucasians. Non-translation of the categories ‘people of color’ and ‘women of color’ generates, amongst other things, the search for a post-Soviet ‘woman of color’ as a Russophone intersectional feminist subject, the canonization of raw translation, the translingual proliferation of ethnoracial categories and the instrumentalization of the figure of ‘trans woman of color’ by Russophone radfem as a mark of Russophone intersectionality’s total foreignness. Finally, the term realia emerged in the empirical materials as the quest for localizing the US idiom of race, adjusting intersectionality to the specificities of post-Soviet ethnoracial power dynamics. Within the project of racial translation in Timati’s hip-hop, I show how Timati marrying of US black hip-hop aesthetics and Russian glamour in the 2000s deployed untranslated foreign US blackness as a cosmopolitan cultural capital to alleviate the violence of post-Soviet racialization. Approximating US black aesthetics through the direct experience of ‘the source,’ Timati’s ethnoracial malleability and capacity to mediate between post-Soviet markets, local economic elites, US racial authenticity, and US hip-hop celebrities brought him international success, yet hardly helped alleviate chronic hip-hop inauthenticity in Russia. Attempts to manage the stigma of foreignness and imitation and hence achieve a stronger hip-hop authenticity domestically marked a reorientation of Timati’s project of racial translation. From 2012-2013, the Caucasus and Caucasian masculinities figure as ‘regional originals,’ allowing Timati to translate the US black masculinity underpinning US hip-hop authenticity through the strategies of vicarious realness, memetics, and hip-hop homophobia in a gay bashing hip-hop meykhana cipher and visual Imperial tropes of the Caucasian sublime. The beard as racial/sexual metonymy is central for understanding Timati’s project of racial translation involved in East-West sexual geopolitics in the period of 2014-2015: through hip-hop modernity and the twin fantasy of ethnoracial mixing and Central Asian migrant economic uplift in Russia, the ethnoracial other is revalorized away from the image of the security threat (bearded terrorist) as modern, homophobic and cool, able to secure Russia’s organic and multinational future against corrupt and sexually perverse Europe. The pinnacle of Timati’s project of racial translation in 2014-2016 resulted in the invention of a deliberately memetic character, Teymuraz, enacting racialized cliches of Caucasian and Central Asian men. Teymuraz, as part of Russia’s hybrid cultural trend of aesthetic populism, recycles the elements of New East gopnik style, Soviet and post-Soviet comedies about men from the Caucasus and Central Asia, mixes elements of social critique, and appropriates the voices of the subaltern, performing a peculiar patriotic anti-racist project with contradictory implications. Timati’s 2015 ludic performances of hip-hop patriotism, coupled with performative disidentifications from the USA as a source of hip-hop, are read as a strategy of hip-hop localization in the changing geopolitical context of Russia’s turn away from the West. Russian discourses of hip-hop authenticity, preoccupied with detecting and exposing plagiarism in Timati’s work, serve to discern ‘real’ hip-hop from ‘fake’ hip-hop. These acts of discernment draw on the racialized discourses of commerce and immorality, marking Timati as ‘foreign’ - both outside the borders of the genre and the Russian nation – thus exposing the Russian ethnonational bias underpinning Russian discourses of hip-hop authenticity. Keywords: translation, intersectionality, race, ethnoracial, post-Soviet, Russian hip-hop, hip-hop, rap, Russian rap, grassroots feminism, digital feminism, feminist chronotopes, feminist translation, feminist activism, popular music, Russia, Russophone, translation strategies, literalism, transliteration, homophobia, transphobia, vicarious realness, memetics, realia, racial/sexual metonymy, indexicality, multimodality, Cold War, Russian popular culture, digital activism, authenticity, hip-hop masculinities, racialization, Caucasus, Central Asia.Doktorgradsavhandlin

    Warm Solutions: Medical Making & Collaborative Infrastructure for Care

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    Making, as an activity and culture, enables people to participate in technological innovation at non-traditional sites. In healthcare settings, medical makers undertake activities as a part of routine, professional care practice. Their collaborative process occurs at the intersection of centralized healthcare systems and decentralized maker technologies with reflexive opportunities for human-centered design. In my research, I propose a critical view of medical making as an opportunity to reposition the power to participate in design within traditional healthcare practice. I develop my thesis from multiple efforts in a wide ecosystem of medical makers across private and public practice, STEM institutions, academic research labs, and non-profit groups. I apply Science and Technology Studies (STS) and HCI theories to analyze stakeholder efforts in relation to long-term patient-centered care infrastructure. Embedded in practice, infrastructure becomes visible in relation to its use. In my dissertation, I develop an understanding of how stakeholders in healthcare settings and networks influence care infrastructure with maker technologies. I do this by foregrounding the norms, values, and expertise related to stakeholder participation across three sections. First, I re-locate the site where physician-led making begins from labs to the bedside – as safe, reliable, small-scale prototypes. Second, I re-frame the importance of medical making, with lessons from the COVID-19 pandemic, when grassroot- and institutional makers repaired temporary manufacturing breakdowns by creating reliable medical supplies. Third, I re-center the role of point-of-care medical makers, highlighting present-day nurse contributions as makers and contrasting their historically undocumented contributions in routine care. My research work culminates in a discussion of the human infrastructure, in addition to information systems, required to design environments for innovation based on the case study of medical making. For HCI researchers, this work first diversifies design values of novelty to include healthcare values of safety, reliability, and verifiability in collaborative systems, and second, extrapolates lessons from medical making to build fair, equitable, and sustainable infrastructure for collaboration between experts and non-experts. From these value-driven insights, I hope my work further contributes practical, methodological, and ethical implications for multiple stakeholders including policymakers and researchers.Ph.D

    (Re)Organizing Toronto Households during COVID-19 Lockdown: A case study on an Imposed Degrowth Scenario

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    By design or by disaster, the growth-oriented capitalist economy must come to terms with the biophysical limits of our finite planet. Many ecological economists make the intentional contraction – or degrowth – of total material and energy use in the global economy a precondition to an environmentally sustainable low-carbon alternative. However, in the context of increasing and concurrent social and environmental upheaval, degrowth “by design” should not be the only avenue explored – nor should a smooth economic transition be presumed. Degrowth research and practice must confront the devastating implications of extreme events, and be ready to counter capitalism’s exploitation of such occurrences as they increase in scale and intensity over time. Situating the COVID-19 pandemic lockdown measures as an imposed degrowth scenario, my thesis explores the possibilities and challenges of mobilizing economic alternatives during times of disruption. Through an exploratory case study, I investigate the experience of 42 Toronto, Canada households as they rapidly respond to an ongoing public health crisis to illuminate strategies for, and barriers to, engaging in degrowth politics and practice. First, I examine parallels between the pandemic lockdown and the degrowth imperative to establish the novel concept of an imposed degrowth. Second, I identify potential subjects, sites and tactics of a degrowth revolution, as well as barriers to realization, at the household scale. Third, building on the experiences of my participants, I enhance degrowth policy recommendations for a more robust response to an increasingly unstable climate future. My research aims to underscore the value of the degrowth imperative for responding to disruptive events while actively mobilizing sustainable economic alternatives. Following Latouche’s “Eight R’s of Degrowth”, my study demonstrates the role of households in cultivating a multiplicity of degrowth politics and practices. This includes re-evaluating personal and professional priorities, strengthening social networks, and calling for the public provisioning of universal basic needs. Participating households also faced a number of barriers to action, including the exacerbation of social harms, the loss of crucial services, and conflicting public health guidelines. The outcomes of this study make visible the labours, tensions and contradictions at play in the process of the everyday degrowth revolution. The realities of the pandemic further serve to expose the limits of an economic system predicated on growth, and underscore the importance of developing alternatives in the face of a climate uncertain future. The question becomes whether this crisis builds the impetus needed to mobilize such alternatives, or whether an even greater crisis will incapacitate entire economies before alternatives can be implemented

    Physiological and ecological implications of sequestered cardenolides in the milkweed bugs (Heteroptera: Lygaeinae)

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    Milkweed bugs (Heteroptera: Lygaeinae) have a predilection for toxic plants, and possess a distinctive black and red coloration. Although many milkweed bugs are generalist seed predators, they commonly feed on plants in the family Apocynaceae (milkweed) which often contain toxic cardenolides. Cardenolides inhibit the ubiquitous Na+/K+-ATPase, an essential animal enzyme mediating essential physiological functions. Milkweed bugs possess pronounced insensitivity towards cardenolides due to a few amino acid substitutions in the Na+/K+-ATPase (i.e., target site insensitivity) and sequester cardenolides for protection against their predators. The overarching question remains whether chemical defenses, in aposematic individuals sequestering toxins, incur physiological costs, such as effects on growth or other fitness parameters like longevity and fecundity, production of color pigments, and handling oxidative stresses, and/or ecological costs, such as universality of toxin defense. Using an artificial diet, I raised larvae of four milkweed bug species (Oncopeltus fasciatus, Caenocoris nerii, Spilostethus pandurus and Arocatus longiceps) and a closely related pyrrhocorid bug species (Pyrrhocoris apterus) on three increasing dietary doses of cardenolides, and assessed the increase in growth by recording the mass until adult. Additionally, I investigated the life-history parameters only in O. fasciatus. To understand if milkweed bugs exhibit honest signaling, using same artificial diet treatment, the color intensity of O. fasciatus was measured by taking photographs in each larval stage until adulthood. To understand if toxin sequestration in milkweed bugs imposes oxidative stress, biomarkers of oxidative stress was measured through biochemical assays for lipid peroxidation (malondialdehyde, or MDA), superoxide dismutase (SOD), and total glutathione content (GSH). To understand why protection against certain predators is not observed in all bug species although they feed on seeds containing cardenolides, I tested if the outcome of predator- prey interaction was mediated by the structural variation within the same class of compound or by the insect species. For this purpose, I raised two milkweed bug species (Lygaeus equestris and Horvathiolus superbus) on the seeds of two phylogenetically unrelated host plants (Ranunculaceae: Adonis vernalis and Plantaginaceae: Digitalis purpurea) from which the bugs sequestered cardenolides, and carried out predation assays with lacewing larvae. The amount of toxins sequestered by the milkweed bugs was estimated using high performance liquid chromatography. My research revealed that dietary plant toxins increased growth in the sequestering specialists (O. fasciatus and C. nerii) but not in the sequestering generalist, S. pandurus, despite all possessing toxin-resistant Na+/K+-ATPases. Under exposure to the dietary toxins, the growth of A. longiceps nymphs (resistant and non-sequestering) was unaffected, while that of P. apterus (non-resistant and non-sequestering) was impaired. In addition, O. fasciatus nymphs developed to adults faster and lived longer as adults under toxin exposure when compared to individuals raised on the control diet, but produced significantly fewer offspring unless being transferred to a toxin-free diet after reaching adulthood. Furthermore, I showed that O. fasciatus raised on the high and medium levels of dietary cardenolides had significantly lower levels of GSH. Bugs with more GSH levels had brighter warning signals but these signals were not related to sequestration. Besides physiological aspects, the chance of milkweed bugs surviving a predator attack strongly depended on the structural differences of sequestered toxins. Overall, I found that cardenolide consumption exerts a positive effect on overall fitness in milkweed bugs, a conclusion in disagreement with current theory predicting costs of sequestration. Oxidative state may be a fundamental aspect where costs lie in aposematic individuals sequestering toxins, and the effect of plant-toxin sequestration on predators is affected by the structural variation of defensive compounds and therefore depends on the ecological context, i.e., host-plant use. My dissertation provides insight into the implications of physiology and ecology on sequestering aposematic insects, giving us a better understanding of plant-insect-predator interactions.Ritterwanzen (Heteroptera: Lygaeinae) sind haeufig generalistische Samenraeuber und weisen eine charakteristische schwarz-rote Faerbung auf. Die Wanzen bevorzugen Samen toxischer Pflanzen aus der Familie der Apocynaceae (Hundsgiftgewaechse). Diese enthalten Cardenolide, welche die ubiquitaer vorkommende Na+/K+-ATPase hemmen, die essenzielle physiologische Funktionen im tierischen Organismus einnimmt. Lygaeinae besitzen aufgrund einiger Aminosaeure-Substitutionen in der Na+/K+-ATPase eine ausgepraegte Resistenz gegenueber den toxischen Cardenoliden und sequestrieren diese zum Schutz vor Fressfeinden. Die uebergeordnete Fragestellung meiner Dissertation ist, ob die Sequestrierung von Toxinen bei aposematischen Vertretern der Lygaeinae physiologische (z. B. Wachstum, Lebensspanne, Fruchtbarkeit, Produktion von Farbpigmenten und Umgang mit oxidativem Stress) und oekologische Kosten (z. B. Universalitaet der Toxin vermittelten Abwehr) verursacht. Mithilfe einer artifiziellen Diaet, welche Cardenolide in drei ansteigenden Konzentrationen enthielt, zog ich Nymphen von vier Lygaeinae-Arten (Oncopeltus fasciatus, Caenocoris nerii, Arocatus longiceps und Spilostethus pandurus) und eine eng verwandte Feuerwanzenart (Pyrrhocoris apterus) bis zum Adultstadium auf. Das Wachstum wurde bei allen Arten durch Gewichtsanalysen verfolgt, weitere Fitnessparameter wurden nur fuer Oncopeltus fasciatus ermittelt. Farbintensitaet von O. fasciatus sowie oxidativer Stress wurden mittels Bildaufnahmen und biochemischen Methoden zum Nachweis von Lipidperoxidation (Malondialdehyd oder MDA), Superoxiddismutase (SOD) und Gesamtglutathiongehalt (GSH) in allen Nymphen-Stadien bis hin zum adulten Tier gemessen. Um zu verstehen, warum ein Schutz gegen bestimmte Praedatoren nicht bei allen Wanzenarten nach dem Verzehr herzglykosidhaltiger Samen beobachtet wird, untersuchte ich, ob das Ergebnis der Raeuber-Beute-Interaktion durch die strukturelle Variation innerhalb derselben Verbindungsklasse oder durch die Insektenspezies beeinflusst wurde. Dazu zog ich zwei Arten von Ritterwanzen (Lygaeus equestris und Horvathiolus superbus) auf Samen zweier phylogenetisch nicht verwandter Wirtspflanzen (Ranunculaceae: Adonis vernalis und Plantaginaceae: Digitalis purpurea) auf, deren Cardenolide die Wanzen sequestrierten und fuehrte Praedationsexperimente mit Florfliegenlarven durch. Die Menge an sequestrierten Toxinen habe ich mittels Hochleistungsfluessigkeitschromatographie erfasst. Meine Untersuchungen ergaben, dass die mit der Nahrung aufgenommenen Pflanzentoxine das Wachstum der sequestrierenden Nahrungsspezialisten (O. fasciatus und C. nerii), nicht aber das der sequestrierenden Nahrungsgeneralisten, S. pandurus, beschleunigten, obwohl sie alle Toxin resistente Na+/K+-ATPasen besitzen. Unter Toxin-Exposition war das Wachstum der A. longiceps Nymphen (resistent und nicht sequestrierend) unbeeinflusst, waehrend das der P. apterus (nicht resistent und nicht sequestrierend) beeintraechtigt war. Darueber hinaus erreichten O. fasciatus Nymphen unter Toxin-Exposition frueher das Adultstadium und lebten zudem laenger, als Individuen, die auf einer Kontroll-Diaet ohne Toxine aufgezogen wurden. Allerdings produzierten sie deutlich weniger Nachkommen, wenn sie nach Erreichen des adulten Stadiums nicht auf eine Toxin freie Diaet umgestellt wurden. Weitergehend konnte ich zeigen, dass jene O. fasciatus, welche auf Diaet mit hohen und mittleren Cardenolid- Konzentrationen aufgezogen wurden, deutlich geringere GSH-Werte aufwiesen. Wanzen mit hoeheren GSH-Werten zeigten leuchtendere Signalfarben, die jedoch nicht mit der Sequestrierung korrelierten. Neben physiologischen Aspekten hing die Wahrscheinlichkeit, ob Ritterwanzen den Angriff eines Fressfeindes ueberlebten, stark von den strukturellen Unterschieden der sequestrierten Toxine ab. Zusammenfassend konnte ich zeigen, dass Cardenolid-Konsum einen positiven Effekt auf die Gesamtfitness mancher Ritterwanzen hat, was im Widerspruch zur aktuellen Lehrmeinung steht, dass durch Sequestrierung physiologische Kosten verursacht werden. Der oxidative Zustand der Tiere weist dennoch auf potentielle physiologische Kosten der Toxin-Sequestrierung hin. Die Wirkung der Toxin-Sequestrierung auf Fressfeinde wird durch strukturelle Variationen der toxischen Verbindungen zur Abwehr beeinflusst, sie haengt daher vom oekologischen Kontext, sprich der Verwendung bestimmter Wirtspflanzen ab. Die vorliegende Dissertation gibt einen Einblick in die physiologischen und oekologischen Konsequenzen von Sequestrierung bei aposematischen Insekten und verhilft zu einem besseren Verstaendnis der Wechselwirkungen zwischen Pflanzen, Insekten und Fressfeinden

    Wheat pollen viability and physiological, biochemical and biophysical factors impacting pollen storability

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    Pollen has high potential to preserve and exchange nuclear genes of plant genetic resources. To facilitate breeding programs, short- and more importantly long-term pollen preservation protocols have been established for many species. Long-term pollen preservation, particularly in wheat breeding programs, and especially with spatially and temporally isolated parents, would be of great interest to expand genetic diversity and to facilitate hybrid seed production. Wheat sheds tricellular pollen at maturity which loses the ability to germinate under ambient conditions within one hour. So far, neither short- nor long-term storage protocols for wheat pollen have been established, and physiological, ultrastructural and biochemical processes in pollen after shedding are hardly understood. To gain a comprehensive overview of processes contributing to fast viability loss, in this thesis, three consecutive studies on the viability and storability of wheat pollen were conducted. First, a comparison of different viability tests and their reliability for use in wheat pollen was made (Chapter 2, Manuscript 1). Second, two different environmental factors (temperature and relative humidity, RH) were investigated for their influence on wheat pollen longevity, physiological properties, pollen ultrastructure and metabolism (Chapter 3, Manuscript 2). Finally, experiments were conducted to investigate the feasibility of cryopreservation for wheat pollen (Chapter 4, Manuscript 3). In the first study a consistent semi-solid in vitro pollen germination medium containing raffinose, boric acid, calcium chloride and gelrite was formulated and compared against existing media (Jian et al. 2014; Jayaprakash et al. 2015; Cheng and McComb 1992) for wheat pollen. The medium formulation resulted in consistent germination percentages for fresh pollen of > 87%. The germination was correlated with pollen viability assessed by impedance flow cytometry (IFC viability, r = 0.67, P < 0.001) and fluorescein diacetate (FDA, r = 0.54, P < 0.05) staining (Chapter 2, Manuscript 1, Figure 5). However, when the medium was used with other Poaceae pollen species, germination was low and assumed to require further adaptation. Although, FDA and IFC viability can be easily applied both, FCR and IFC, seem to overestimate pollen viability (Chapter 2, Manuscript 1, Figure 5). Therefore, two viability tests, in vitro germination and IFC viability, were applied in consecutive studies. The second work revealed that low temperature (~ 4 °C) and high RH (> 90%) could keep pollen viable with a maximum of > 70% pollen germination after 60 minutes storage. The metabolic changes were most pronounced in unfavourable conditions (low RH and room temperature) were pollen lost most of its viability (pollen germination reached only 10%) after short storage of only 20 to 30 minutes. Under these conditions, wheat pollen showed extensive and deleterious changes in the ultra-structure (intine and cytoplasmic organization), fluctuations in primary metabolite concentration, and changes in water content (WC) (Chapter 3, Manuscript 2, Figures 1, 2, 6, 7). Overall, metabolic status, ultrastructural and WC changes lead to irreversible damages and viability loss suggesting that wheat pollen is not equipped with sufficient protection mechanisms to survive longer periods. Additionally, in these two studies we found differences in germination percentage (Manuscript 1, Figure 6; Manuscript 2, Supplemental Figure S4) and metabolite concentrations of specific compounds (Manuscript 2, Figure 4) between different genotypes tested. Thus, it is suggested that the genotype may have an important influence on pollen survival. Further research with a wide range of genotypic implications could reveal marker genes that might influence wheat pollen viability under different conditions. In the third study, it was tested if wheat pollen may be able to survive cryopreservation. Therefore, wheat pollen had been dried and cooled under different regimes. Rapidly dried wheat pollen to WC above the unfrozen water content (0.91 ± 0.11 mg H2O mg-1 DW) for 5 min retained IFC viability of around 6.1 ± 8.8% after fast cooling and warming but were not able to germinate. Nevertheless, damages induced by dehydration and cryo-injury during ultra-low temperature exposure seemed to occur to a lesser extent in the rapidly dried pollen compared to fresh pollen and pollen dried at ambient conditions for both, slow and rapid cooling/warming. Thus, within a very small window of a specific pollen WC and further adjustment pollen may survive cryopreservation storage. Future research and amendment of fast-drying and an optimisation of the cooling/warming rate will reveal whether the survival rate of pollen can be increased after exposure to cryo-storage. The use of cryoprotection may have favourable effects on the survival. Further suggestions for possible improvements of cryopreservation will be discussed in one of the sections of discussion

    Looking for dementia friendly communities: towards an interdisciplinary understanding using a case study, fragments and cut-ups

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    This thesis tries to develop an understanding of the phenomenon of ‘Dementia Friendly Communities’ (DFCs), a policy initiative which has been pursued during the last decade in the nations and regions of the UK, and other parts of the world. In Wales, this has coincided with a radical shrinking of state budgets to deliver social care support, often called ‘austerity’, and rising interest in the policy and cultural implications of an ageing society, and how dementia has seemingly become more central in that demographic trend. This inquiry arises initially from a critical gerontology perspective but develops along lines which borrow from cultural geography and post-war, avantgarde literature. Such an interdisciplinary approach presents opportunities for using novel methods of collecting and analysing material. Though conventional ethnographic techniques such as participant observation, interviewing and photography were used throughout, I also introduce practises such as writing using spontaneous prose, collaging or cut-ups, as an alternative means of analysis. During fieldwork, I attended various events and meetings with those involved in developing DFCs, including ‘dementia activists’, and witnessed the development of ‘Meeting Centres’ as a chosen approach to support those with dementias and their carers in the market town of Brecon, south Wales. From this, a picture emerges of a phenomenon which seems contingent and difficult to grasp, but offers space for critical counter-conducts, glimpses of community-making and types of citizenship. Foucauldian concepts such as biopolitics, governmentality and pastoral power, alongside more non-representational and affective approaches, were used throughout. Writers such as William S. Burroughs, Georges Perec and others inspired ‘ways of doing and making that [could] intervene in the general distribution of ways of doing and making’ (Ranciùre, 2004, p13). Findings are presented as a series of fragments, including fictocritical and anecdotal writing, collages and cut-ups of materials generated. The main contribution of this study is to attempt to a more nuanced portrayal of DFCs as found, whilst developing methods which question epistemic boundaries, and may have practical potential for synthesising new materials across disciplinary borders

    A MODELING PERSPECTIVE ON DEVELOPING NATURALISTIC NEUROPROSTHETICS USING ELECTRICAL STIMULATION

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    Direct electrical stimulation of neurons has been an important tool for understanding the brain and neurons, since the field of neuroscience began. Electrical stimulation was used to first understand sensation, the mapping of the brain, and more recently function, and, as our understanding of neurological disorders has advanced, it has become an increasingly important tool for interacting with neurons to design and carry out treatments. The hardware for electrical stimulation has greatly improved during the last century, allowing smaller scale, implantable treatments for a variety of disorders, from loss of sensations (hearing, vision, balance) to Parkinson’s disease and depression. Due to the clinical success of these treatments for a variety of impairments today, there are millions of neural implant users around the globe, and interest in medical implants and implants for human-enhancement are only growing. However, present neural implant treatments restore only limited function compared to natural systems. A limiting factor in the advancement of electrical stimulation-based treatments has been the restriction of using charge-balanced and typically short sub-millisecond pulses in order to safely interact with the brain, due to a reliance on durable, metal electrodes. Material science developments have led to more flexible electrodes that are capable of delivering more charge safely, but a focus has been on density of electrodes implanted over changing the waveform of electrical stimulation delivery. Recently, the Fridman lab at Johns Hopkins University developed the Freeform Stimulation (FS)– an implantable device that uses a microfluidic H-bridge architecture to safely deliver current for prolonged periods of time and that is not restricted to charge-balanced waveforms. In this work, we refer to these non-restricted waveforms as galvanic stimulation, which is used as an umbrella term that encompasses direct current, sinusoidal current, or alternative forms of non-charge-balanced current. The invention of the FS has opened the door to usage of galvanic stimulation in neural implants, begging an exploration of the effects of local galvanic stimulation on neural function. Galvanic stimulation has been used in the field of neuroscience, prior to concerns about safe long-term interaction with neurons. Unlike many systems, it had been historically used in the vestibular system internally and in the form of transcutaneous stimulation to this day. Historic and recent studies confirm that galvanic stimulation of the vestibular system has more naturalistic effects on neural spike timing and on induced behavior (eye velocities) than pulsatile stimulation, the standard in neural implants now. Recent vestibular stimulation studies with pulses also show evidence of suboptimal responses of neurons to pulsatile stimulation in which suprathreshold pulses only induce about half as many action potentials as pulses. This combination of results prompted an investigation of differences between galvanic and pulsatile electrical stimulation in the vestibular system. The research in this dissertation uses detailed biophysical modeling of single vestibular neurons to investigate the differences in the biophysical mechanism of galvanic and pulsatile stimulation. In Chapter 2, a more accurate model of a vestibular afferent is constructed from an existing model, and it is used to provide a theory for how galvanic stimulation produces a number of known effects on vestibular afferents. In Chapter 3, the same model is used to explain why pulsatile stimulation produces fewer action potentials than expected, and the results show that pulse amplitude, pulse rate, and the spontaneous activity of neurons at the axon have a number of interactions that lead to several non-monotonic relationships between pulse parameters and induced firing rate. Equations are created to correct for these non-monotonic relationships and produce intended firing rates. Chapter 4 focuses on how to create a neural implant that induces more naturalistic firing using the scientific understanding from Chapters 2 and 3 and machine learning. The work concludes by describing the implications of these findings for interacting with neurons and population and network scales and how this may make electrical stimulation increasingly more suited for treating complex network-level and psychiatric disorders
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