High-pressure cylindrical ion trap mass spectrometry

This work describes the development of mass spectrometry (MS) instrumentation capable of operating at helium buffer gas pressures up to 1 torr. This is approximately three orders of magnitude higher than the pressures used in commercially available MS instrumentation. High-pressure operation is desirable since it reduces the size, weight, and power (SWaP) of the instrument by reducing the pumping system workload. A simple and rugged roughing pump could achieve these pressures while reducing SWaP by eliminating the turbo pump. Therefore this technology could be used to develop next generation hand-portable instruments and bring MS to new applications. Custom MS instrumentation was designed and built to utilize 500 μm radius cylindrical ion trap (CIT) mass analyzers. Two vacuum chamber configurations were used to establish a performance baseline at traditional ion trap operating pressures. The instrument design was refined during these simple experiments before moving to high-pressure operation. The feasibility of high-pressure CIT operation up to 1 torr was first demonstrated using a differentially pumped instrument. Electron ionization was performed and a mass-selective instability scan was used to eject ions into a low-pressure chamber for detection with an electron multiplier. Peak broadening effects at high pressure were reduced by increasing axial RF amplitude and ejecting ions into a low-pressure detection region. Peak widths for Xe+ spectra at pressures from 38.6 to 983.5 mTorr were analyzed and average peak widths for these low and high-pressure spectra were found to be relatively constant. After demonstrating the CIT operation at high pressure, it was desirable to replace the electron multiplier with a pressure tolerant detector and simplify the instrument to a single vacuum chamber. The first experimental investigation of MS in this isobaric chamber at pressures up to 867 mTorr is reported. A solid-state capacitive transimpedance amplifier (CTIA) was used for ion detection at high pressures. Average peak widths for Xe+ ions in spectra acquired at pressures from 133 to 867 mTorr were found to be nearly constant. Results presented here demonstrate mass spectra at ~1 torr using a solid-state ion detector capable of operating at atmospheric pressure for MS applications requiring portability.Doctor of Philosoph

From Isotopes to TK Interviews: Towards Interdisciplinary Research in Fort Resolution and the Slave River Delta, Northwest Territories

Evolving research in Fort Resolution and the Slave River Delta, Northwest Territories, aims to improve understanding of how the natural ecosystem functions and responds to various environmental stressors, as well as to enhance the stewardship of natural resources and the capacity of local residents to respond to change. We seek to integrate approaches that span the natural and social sciences and traditional knowledge understandings of change, employing a research design developed in response to the concerns of a northern community. In doing so, we have strived for a research process that is collaborative, interdisciplinary, policy-oriented, and reflective of northern priorities. These elements characterize the new northern research paradigm increasingly promoted by various federal funding agencies, northern partners, and communities. They represent a holistic perspective in the pursuit of solutions to address complex environmental and socioeconomic concerns about impacts of climate change and resource development on northern societies. However, efforts to fulfill the objectives of this research paradigm are associated with a host of on-the-ground challenges. These challenges include (but are not restricted to) developing effective community partnerships and collaboration and documenting change through interdisciplinary approaches. Here we provide an overview of the components that comprise our interdisciplinary research program and offer an accounting of our formative experiences in confronting these challenges

Lateral Oblique Approach to an Ultrasound-Guided Internal Jugular Central Line Placement

Presented as a poster at Indiana Society of Anesthesiologists Annual Meeting 2021

From Isotopes to TK Interviews: Towards Interdisciplinary Research in Fort Resolution and the Slave River Delta, Northwest Territories

Evolving research in Fort Resolution and the Slave River Delta, Northwest Territories, aims to improve understanding of how the natural ecosystem functions and responds to various environmental stressors, as well as to enhance the stewardship of natural resources and the capacity of local residents to respond to change. We seek to integrate approaches that span the natural and social sciences and traditional knowledge understandings of change, employing a research design developed in response to the concerns of a northern community. In doing so, we have strived for a research process that is collaborative, interdisciplinary, policy-oriented, and reflective of northern priorities. These elements characterize the new northern research paradigm increasingly promoted by various federal funding agencies, northern partners, and communities. They represent a holistic perspective in the pursuit of solutions to address complex environmental and socioeconomic concerns about impacts of climate change and resource development on northern societies. However, efforts to fulfill the objectives of this research paradigm are associated with a host of on-the-ground challenges. These challenges include (but are not restricted to) developing effective community partnerships and collaboration and documenting change through interdisciplinary approaches. Here we provide an overview of the components that comprise our interdisciplinary research program and offer an accounting of our formative experiences in confronting these challenges.Des travaux de recherche en cours à Fort Resolution et dans le delta de la rivière des Esclaves, aux Territoires du Nord-Ouest, visent à mieux comprendre le fonctionnement de l’écosystème naturel, à réagir aux divers facteurs d’agression environnementaux ainsi qu’à rehausser la gérance des ressources naturelles et la capacité des habitants de la région à réagir au changement. Nous cherchons à intégrer des méthodes qui englobent les sciences naturelles et sociales et favorisent la compréhension du changement du point de vue des connaissances traditionnelles. Nous cherchons également à employer une méthodologie respectueuse des inquiétudes de la collectivité du Nord. Ce faisant, nous avons abouti à un processus de recherche caractérisé par la collaboration, l’interdisciplinarité et les politiques, processus qui tient également compte des priorités dans le Nord. Ces éléments définissent le nouveau paradigme de recherche dans le Nord qui est de plus en plus préconisé par divers organismes de subvention fédéraux, partenaires du Nord et collectivités. Ils représentent une perspective holistique en guise de solutions à des enjeux environnementaux et socioéconomiques complexes portant sur les incidences du changement climatique et de l’exploitation des ressources sur les sociétés du Nord. Toutefois, les efforts visant à concrétiser les objectifs de ce paradigme de recherche font face à une multitude de défis. Ces défis comprennent (mais sans s’y restreindre) la formation de partenariats efficaces avec les collectivités, des efforts de collaboration et la prise de notes sur les changements qui s’opèrent grâce à des méthodes interdisciplinaires. Ici, nous fournissons un aperçu des éléments de notre programme de recherche interdisciplinaire et donnons un aperçu de l’expérience formative qui a découlé de ces défis

Gain, Loss and Divergence in Primate Zinc-Finger Genes: A Rich Resource for Evolution of Gene Regulatory Differences between Species

The molecular changes underlying major phenotypic differences between humans and other primates are not well understood, but alterations in gene regulation are likely to play a major role. Here we performed a thorough evolutionary analysis of the largest family of primate transcription factors, the Krüppel-type zinc finger (KZNF) gene family. We identified and curated gene and pseudogene models for KZNFs in three primate species, chimpanzee, orangutan and rhesus macaque, to allow for a comparison with the curated set of human KZNFs. We show that the recent evolutionary history of primate KZNFs has been complex, including many lineage-specific duplications and deletions. We found 213 species-specific KZNFs, among them 7 human-specific and 23 chimpanzee-specific genes. Two human-specific genes were validated experimentally. Ten genes have been lost in humans and 13 in chimpanzees, either through deletion or pseudogenization. We also identified 30 KZNF orthologs with human-specific and 42 with chimpanzee-specific sequence changes that are predicted to affect DNA binding properties of the proteins. Eleven of these genes show signatures of accelerated evolution, suggesting positive selection between humans and chimpanzees. During primate evolution the most extensive re-shaping of the KZNF repertoire, including most gene additions, pseudogenizations, and structural changes occurred within the subfamily homininae. Using zinc finger (ZNF) binding predictions, we suggest potential impact these changes have had on human gene regulatory networks. The large species differences in this family of TFs stands in stark contrast to the overall high conservation of primate genomes and potentially represents a potent driver of primate evolution

Domesticating Fears and Fantasies of ‘the East’: integrating the Ottoman legacy within European heritage

'Europe' has no fixed geographical, historical, religious or cultural boundaries. Claims for the existence of European civilization as a discrete construct are continually made yet dissolve on close scrutiny. Here, we examine these claims at one of the grandest points of existential crisis and belonging for Europe, the relationship with the 'Other within': Turkey, the Balkans and Ottoman heritage in Europe. Through a hybrid semiotic and Foucauldian analysis of catalogues of eight high-profile exhibitions in the United Kingdom, Turkey, Belgium and Portugal we argue that an unsettled discursive struggle is at play, in which one 'Europe' articulates 'reconciliation' of profound civilizational difference while another, Ottoman, 'Europe' stakes a claim of right as an intrinsic component of what it means to be European in a contemporary context. We attempt to trace the role of museum marketing in the perennial accommodation/exclusion of the Ottoman Empire as an intrinsic component in the diversity of Europe’s cultural heritage

Self-Organization of the Escherichia coli Chemotaxis Network Imaged with Super-Resolution Light Microscopy

Photoactivated localization microscopy analysis of chemotaxis receptors in bacteria suggests that the non-random organization of these proteins results from random self-assembly of clusters without direct cytoskeletal involvement or active transport