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Intralinguistic and Crosslinguistic Variation in the Turn-taking Organization Between Deaf-blind Signers: new evidence from Bay Islands Sign Language
Get PDFThis paper examines the turn-taking organization between two deaf-blind signers of Bay Islands Sign Language (BISL) and discusses how this language presents unique intra- and cross-linguistic variation. Following the framework of conversation analysis adapted to tactile sign languages, a case study was done on an extract of a conversation in the BISL corpus. One area of intra-linguistic variation is influenced by whether signers can perceive the language visually as well as tactilely. Signers use non-manual markers like nodding to backchannel when interacting with others who may be able to perceive them visually, but tactile-proprioceptive backchanneling techniques with blind interlocutors. Variation is also influenced by the type of co-formation employed by the signer. Cross-linguistically, this paper introduces several features which differ from previous descriptions of tactile languages. BISL signers are seen to nod with conversational purpose. Also, a novel technique for turn yielding in BISL involving throwing the hands of the interlocutor in the air has not been previously documented. The particular demographics and social history of the BISL community seem to be responsible for a number of features which differ from other tactile languages
How Do Your Genes Smell? Applying Genetic Tools To Understand Olfactory Perception
Get PDFMany of the major milestones in understanding the olfactory system have arisen from research conducted in non-human animal models through the use of various genetic tools. While mammalian olfaction is largely conserved, there are several key differences in humans that suggest the necessity of studies directed at human olfaction. The human olfactory system has both genotypic variation and phenotypic variation, suggesting that, like in animal research, genetic tools are viable and vital for investigating human olfaction. We first address the basic questions of the human olfactory system, examining whether our assumptions based on animal olfaction are confirmed and attempting to identify mechanisms of the olfactory system that are not well-characterized in humans or other animals. We conducted whole exome sequencing on 52 individuals in ten families with congenital anosmia, an inherited disorder where individuals lack a sense of smell from birth. Through selection of rare, segregating, deleterious variants, we identified 215 genes that are associated with congenital anosmia. These genes are likely to play a role in olfaction, and can therefore serve as a resource for further investigation of the underlying mechanisms of basic human olfaction. We next investigated the relationship between olfactory receptors and odor perception in order to improve our understanding of how odor information is processed at the periphery. Here, we identified two novel associations: a variant in OR51B2 that increases intensity perception of a key component of body odor, and two-linked variants in OR4D6 that predict specific anosmia to the musk compound Galaxolide. Uncovering the relationship between odors and their specific receptors is the first step to understanding how the ~400 olfactory receptors work in combination to code for odor perception. These studies make advances towards a comprehensive understanding of how the human peripheral olfactory system functions and codes olfactory information into odor perception
Investigation Of Metabolism And Autism-Relevant Behaviors In Drosophila Lacking Neurexin-1
Get PDFAutism is a neurodevelopmental condition that is highly heterogeneous in its clinical presentation. In addition to differences in social interaction and communication, and the presence of restrictive, repetitive behaviors, metabolic dysfunction is becoming more widely known and studied as a co-occurring condition seen in autistic individuals. However, the etiology of these metabolic alterations in autism remains unclear. Here, we utilized a combination of metabolomic, physiological, and behavioral assays to investigate how disruption of the autism-risk gene, neurexin-1, influences energy metabolism and associated behaviors in Drosophila melanogaster. These analyses revealed that Drosophila lacking neurexin-1 expression exhibit decreased resistance to environmental stressors, specifically starvation stress and heat stress. These findings lead us to consider whether the neurexin-1 mutant flies have an altered metabolic status, thus we performed metabolomics and complementary colorimetric assays and found that these flies have a distinct metabolic profile, with decreased lipid and carbohydrate stores. Moreover, neurexin-1-null Drosophila exhibit decreased levels of NAD+, an important cofactor in many energy production pathways. Interestingly, loss of neurexin-1 also results in disruptions in mitochondrial morphology in Drosophila flight muscle, in addition to decreased flight ability. Finally, we observed mechanically-induced seizure-like activity in the neurexin-1 mutant flies, which closely mimics clinical data wherein patients with deletions in Neurexin-1 experience seizures. Together, these findings point to a novel role for neurexin-1 in the regulation of energy metabolism and autism-related behavioral phenotypes in Drosophila, in addition to providing a foundation for further investigation into the etiology of metabolic dysfunction and seizures in autism
Dissenting Flesh: Racial Feeling In An Age Of Colorblindness
No full textAt the intersection of critical race theory and affect studies, Dissenting Flesh examines social and political shifts from strong emotions to ambiguous affects, from human subjects to uncanny objects, and from discourse to materiality in contemporary African American and Asian American writings. Dissenting Flesh connects these changing modes of racialized form, feeling, and being to a longer history of American liberalism that claims, to quote Justice John Harlan’s dissent in Plessy v. Ferguson (1896), “our constitution is colorblind.” This dissertation explores how the law’s abstraction of race into neutral skin color has historically been used not to alleviate but rather to obscure the workings of structural racism. By tracing a new genealogy of colorblind racism that precedes and endures after civil rights, Dissenting Flesh demonstrates that colorblindness is not merely a contemporary phenomenon but rather an abiding logic of U.S. law and empire meant to sever subjects from their bodies and histories. Across each chapter, Dissenting Flesh argues that flesh has the potential to disrupt this logic by indexing ongoing processes of racial dispossession in tactile, affective, and material forms. By envisioning the potential of flesh to incite change, this dissertation aims to put forth new methods of dissenting with, and repairing the effects of, an entrenched form of liberal racism. Dissenting Flesh insists, in the process, that combating colorblind racism requires a framework of comparative race. By bringing the model minority paradigm to bear upon Black studies and Black feminist theories of flesh to bear upon Asian American studies, Dissenting Flesh explores how and why liberalism sorts Asian Americans and African Americans into its most prized legal and cultural fictions of racial justice
The Effect Of Source Credibility On Promising Belief Messages: A Message Pretesting Study To Address Covid-19 Vaccine Hesitancy Among Black Americans
Get PDFPublic health messaging campaigns can be useful tools for addressing vaccine hesitancy. Behavior change theory-driven formative research, which guides campaign planners in message topic selection, is necessary for campaigns’ success. However, such research cannot advise on how to communicate campaign messages. Information processing theories propose avenues through which messages can be made more persuasive.
Focusing on Black Americans, this dissertation aims to test an approach to improve future public health messaging campaigns targeting COVID-19 vaccine hesitancy. Specifically, it investigates whether source credibility (an information processing theory variable) can enhance the persuasiveness of differentially promising campaign message topics. These message topics refer to beliefs associated with intention to receive a COVID-19 vaccine.
Study 1 was a two-part belief elicitation. In the first part (Study 1A) participants (N=117) reported their most salient beliefs related to the COVD-19 vaccine in an open-ended survey. The second part involved topic modeling on 5945 tweets discussing the vaccine. Beliefs identified from these studies were transformed into cross-sectional survey items for Study 2. Results from this study highlighted the utility in combining traditional survey data with publicly available social media data to learn about the health concerns of a target population.
Study 2 (N=500) identified beliefs varying in promise, following the Hornik & Woolf approach, to be transformed into message topics. Study 3 was a message experiment where participants (N=245) were exposed to messages, addressing either a “more” or “less” promising topic, designed to increase vaccination intention. The messages were also either communicated by a health professional, or layperson source.
Results of Study 3 indicated no main effects of neither message promise, nor source credibility on vaccination intention. Messages targeting the “less” promising topic shifted the linked belief, but the belief was not associated with intention. Messages on the “more” promising topic did not shift the linked belief, but the belief was strongly associated with intention. Evidence from these studies underline the benefit of choosing the most promising message topics when planning a public health messaging campaign. These results also suggest that additional research is needed to identify credible sources for vaccine non-intenders, and other differentiating characteristics of this unvaccinated population to develop effective public messaging campaigns in the future
Investigating The Role Of Cohesin In Dynamic Genome Folding And Gene Regulation
No full textInside of the nucleus, chromosomes are intricately folded to regulate expression of their genes. Early models of how chromosomes are organized were driven by genomics-based methods that average chromatin contact frequencies across cell populations. These studies revealed that the genome folds into megabase-sized topologically associating domains (TADs), reproducible clusters of self-interacting chromatin. TADs are proposed to form via the loop extrusion model, in which cohesin, a ring-shaped protein complex, extrudes chromatin until paused by the insulator protein CTCF. TADs typically encompass a gene and its regulatory elements, leading to a model in which TADs spatially insulate enhancer-promoter communication to regulate transcription. However, subsequent studies revealed that TAD boundaries were variable in single cells, suggesting TAD formation is dynamic. How such a mercurial system could reliably regulate gene expression was unclear. Here, we unpack the role of cohesin and its regulators in TAD folding and gene expression. We developed a novel imaging-based system to visualize TAD insulation in single cells. Using this system, we find that cohesin promotes chromatin interactions across domain boundaries, contributing to variability in boundary positions. We propose that cohesin dynamically extrudes chromatin past population-defined boundaries in a process we call asymmetric boundary bypass. We find that depleting NIPBL, which is required for cohesin loading and extrusion, decreased inter-domain intermingling, while knocking down WAPL, which opens the cohesin ring to dissociate it from chromatin, increases domain interactions. These knockdowns are accompanied by dysregulation of largely different sets of genes, which were enriched at loop anchors, indicating they are a direct effect of altering levels of cohesin on chromatin. We propose that boundary bypass allows promoters to sample neighboring chromatin for potential regulatory elements, building resiliency into the system. Interestingly, we find this process is regulated by the relative, rather than absolute, amounts of NIPBL and WAPL, as co-depletion of both proteins rescues the effect of either single knockdown on both gene expression and chromatin organization. Our data suggest that gene expression phenotypes associated with reduced cohesin levels could be corrected for by enhancing its processivity on chromosomes, which has wide implications for targeted therapies in cohesinopathies
Chasing The Intact Mind: Autism Discourse, Policy And Practice, 1943-Present
No full textIn her 2006 memoir Strange Son, Cure Autism Now co-founder Portia Iversen described the “intact mind” she believed was buried within even the most cognitively impaired autistic individuals, like her son Dov. But the sentiment itself was not new. Emerging largely out of psychoanalytic theory dating back to the end of the 19th century, the intact mind was amplified in parent memoirs even as biomedical discourse consolidated in the 1970s around a very different depiction of autism: as a biologically based, intractable neurodevelopmental disorder. With as many as 1 out of every 44 American children now affected, according to the CDC, discourse originally unique to autism has come to inform current debates at the heart of intellectual and developmental disability practice and policy in the United States – including battles over sheltered workshops, guardianship, and facilitated communication. This myopic focus, however, inadvertently reproduces historic patterns of discrimination that yoked human worth to intelligence. It is only by making space for the impaired mind, I argue, that we will be able to resolve these ongoing clashes – as well as even larger questions of personhood, dependency, and care
Understanding The Fracture Behavior Of Polymer-Infiltrated Nanoparticle Films
No full textPolymer-infiltrated nanoparticle films (PINFs) are a new class of polymer nanocomposites that overcome many of the challenges in manufacturing highly loaded nanocomposite films (PNCFs). PINFs have a wide range of applications as functional coatings and membranes and have excellent mechanical properties, including high stiffness, hardness, scratch and wear resistance. Fracture toughness is another critical mechanical property that plays an important role in the durability and reliability of PINFs. Establishing a fundamental understanding of the fracture behavior of PINFs is crucial to the design of damage tolerant PINFs.In this work, the effect of particle shape, confinement, and polymer-nanoparticle (NP) interactions on the fracture behavior of PINFs is investigated. The results show that well-aligned, high aspect ratio (AR) nanoplatelet films have significantly higher fracture toughness and larger enhancement in modulus, hardness and scratch resistance upon polymer infiltration than low AR NP films. Using a thin-film fracture testing method based on the double cantilever beam specimen, the role of confinement on fracture toughness is investigated by tuning the polymer molecular weight (MW) and NP size. The effect of polymer-NP interaction strength is also investigated by varying the type of polymer and changing the surface chemistry of NPs. The results show that the polymers can significantly toughen NP films through a confinement-induced molecular bridging mechanism when they are under extreme confinement and completely lose interchain entanglement. This mechanism is controlled by polymer MW, pore size and polymer-NP interaction strength and ultimately limited by the strength of polymer backbone. As the degree of confinement decreases, the bridging mechanism becomes less pronounced. In this case, entanglement-based mechanism becomes dominant and the fracture toughness of PINFs is dependent on the fracture properties of polymers. Finally, it is shown that the fracture toughness of PINFs can be further enhanced using mesoporous NPs due to the increase of polymer-NP interaction area and the interlocking between the polymer and NPs via mesopores. Thus, this work provides important guidelines for the design of mechanically robust PINFs as well as other highly loaded PNCFs
Electrolytic Demagnesiation Of Magnesium Alloys Towards Nanoporous Aluminum And Intermediate Ternary Compounds For Hydrogen Generation And Beyond
No full textHydrogen has the potential to meet the growing demand for clean energy, but several major challenges still need to be addressed. Metal hydrolysis is an approach proposed to produce and utilize hydrogen and to store hydrogen in the form of solid metals and liquid water to address some of these challenges. However, few works focus on studying the reaction of nanostructured metals with deionized water because of the passivation layer that typically forms on metals when exposed to air or water during the metal hydrolysis process. Electrolytic dealloying can be used to prepare nanoporous aluminum metal with high surface areas for hydrolysis, but this method has drawbacks in experimental flexibility. Thus, the focus of this work is on investigating the underlying reactivity of nanoporous aluminum metal in its hydrolysis reaction with pure water and on investigating the additional challenges associated with both the nanoporous metals used for hydrolysis and the electrolytic dealloying synthesis method. First, addressing the challenges of hydrogen were explored. The hydrolysis of nanoporous aluminum at room temperature was explored to create activated alumina as a value-added product to lower the costs of hydrogen produced by this approach. Practical investigation in using nanoporous aluminum showed safety concerns regarding the high reactivity and pyrophoricity of the metal; creating a pellet form of nanoporous aluminum with hygroscopic lithium borohydride was shown to nullify pyrophoricity via accumulation of water vapor at the surface of the pellet and thus increase the air-stability of NP-Al for practical purposes. Finally, the electrolytic dealloying synthesis method to create nanoporous aluminum for hydrolysis was also investigated. Here we show changing the electrolyte was able to synthesis ultrafine nanoporous aluminum, which fundamentally changes the reactivity and possible applications for this material. Changing the parent alloy is also investigated to show isolation and synthesis of the Mg11Cu6Al12 phase, which is difficult to synthesize by regular thermal means. Thus, the capabilities of electrolytic dealloying are fundamentally enhanced from this investigation
Dovish Reputation Theory: When Fighting To Demonstrate Resolve Backfires
Get PDFAccording to traditional, hawkish reputation theory, states inevitably harm their reputation for resolve by backing down and enhance or maintain it by choosing to stand firm and engage in military conflict. This logic has been used, at least in part, to justify consequential interventions like the Vietnam War, which resulted in tens of thousands of deaths and hundreds of billions of dollars spent. However, is it always true that states maximize their reputation for resolve by refusing to back down? In other words, is fighting to demonstrate resolve always a logical reason to go to war? I advance a new theory of reputation—dovish reputation theory—that argues the answer is no. My theory can be summarized in two steps. In the first step, choosing to fight rather than back down in the past can lead to war-weariness that reduces a country’s future level of resolve. In the second step, foreign actors can observe the signs of war-weariness and therefore downgrade their estimates of a country’s reputation for resolve. I test my theory using a multi-method research design that includes survey experiments conducted on the general public and members of the United Kingdom Parliament; large-N statistical analyses of political parties’ election manifestos and militarized interstate disputes; and historical case studies of World War I and the First Iraq War. My analysis yields four key findings. First, the experience of a previous conflict can harm a state’s future resolve. Second, backing down, all else equal, does undermine a state’s reputation for resolve. Third, choosing to fight can also erode a state’s reputation for resolve if signs of war-weariness develop. Fourth, the reputation for resolve costs associated with war-weariness can equal or outweigh the reputation for resolve benefits of not backing down. This means states do not always enhance or maintain their reputations for resolve by engaging in military conflict rather than backing down. The most important implication of this project is that the benefits of using military force are lower than the common wisdom suggests