80 research outputs found
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Advancement of Space Plasma Measurements With Novel Langmuir Probe Technologies
Langmuir probes have been flown on spacecraft missions for in-situ measurements of the local plasma environment from sounding rocket missions to flagship missions like Cassini or Rosetta over the past 50 years. Langmuir probes are conductors of simple geometries (spheres, disks, cylinders, etc.) inserted into a plasma. By sweeping a voltage on the probe and measuring the current collected or emitted, a current-voltage (I-V) relationship can be found and interpreted to derive the density, temperature, and potential of the ambient plasma. However, even after decades of use, there are still challenges in the analysis and interpretation of Langmuir probe measurements due to non-ideal plasma environments encountered by or created by the spacecraft.
In the upper atmospheres of planets atomic oxygen is present in high densities capable of degrading the probe surface, warping the I-V curve of a Langmuir probe or otherwise causing a the probe to incorrectly measure the plasma. Due to plasma interactions with the probe itself and spacecraft there is often an anisotropic or inhomogeneous plasma environments. The following dissertation summarizes the research to find probe coatings whose measurements are least affected by atomic oxygen as well as the construction of a double hemisphere Langmuir probe (DHP) to improve space plasma measurements in: i) Low-density plasmas where the Debye sheath from the SC will interfere with probe measurements; ii) flowing plasmas where asymmetric current collection causes characterization of the density; iii) high-surface-emission environments where photoemission from the probe or SC will pollute the measurements of the ambient plasma.</p
Plasma Soluble Human Elastin Fragments as an Intra-Aneurysmal Localized Biomarker for Ruptured Intracranial Aneurysm
Background—Fragmentation of the tunica media is a hallmark of intracranial aneurysm formation, often leading to aneurysmal progression and subsequent rupture. The objective of this study is to determine the plasma level of elastin fragments in the lumen of ruptured versus unruptured human intracranial aneurysms. Methods and Results—One hundred consecutive patients with/without ruptured saccular intracranial aneurysms undergoing endovascular coiling or stent-assisted coiling were recruited. Blood samples were collected from the lumen of intracranial aneurysm using a microcatheter. The tip of the microcatheter was placed inside the aneurysm’s sac in close proximity to the inner wall of the dome. Plasma levels of elastin fragments were measured using an ELISA-based method. Mean plasma level of soluble human elastin fragments was significantly greater in ruptured aneurysms when compared with nonruptured aneurysms (102.0±15.5 versus 39.3±9.6 ng/mL; P\u3c0.001). Mean plasma level of soluble human elastin fragments did not have significant correlation with age, sex, size, or aneurysm location. Conclusions—The present study revealed that a significantly higher concentration of soluble human elastin fragments in the lumen of ruptured intracranial aneurysms when compared with nonruptured ones. © 2018 The Authors
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Divergent drivers of leaf trait variation within species, among species, and among functional groups.
Understanding variation in leaf functional traits-including rates of photosynthesis and respiration and concentrations of nitrogen and phosphorus-is a fundamental challenge in plant ecophysiology. When expressed per unit leaf area, these traits typically increase with leaf mass per area (LMA) within species but are roughly independent of LMA across the global flora. LMA is determined by mass components with different biological functions, including photosynthetic mass that largely determines metabolic rates and contains most nitrogen and phosphorus, and structural mass that affects toughness and leaf lifespan (LL). A possible explanation for the contrasting trait relationships is that most LMA variation within species is associated with variation in photosynthetic mass, whereas most LMA variation across the global flora is associated with variation in structural mass. This hypothesis leads to the predictions that (i) gas exchange rates and nutrient concentrations per unit leaf area should increase strongly with LMA across species assemblages with low LL variance but should increase weakly with LMA across species assemblages with high LL variance and that (ii) controlling for LL variation should increase the strength of the above LMA relationships. We present analyses of intra- and interspecific trait variation from three tropical forest sites and interspecific analyses within functional groups in a global dataset that are consistent with the above predictions. Our analysis suggests that the qualitatively different trait relationships exhibited by different leaf assemblages can be understood by considering the degree to which photosynthetic and structural mass components contribute to LMA variation in a given assemblage
Right Ventricular Dysfunction and Adverse Outcomes after Renal Transplantation
INTRODUCTION: Pulmonary hypertension is common among patients with end-stage renal disease, although data regarding the impact of right ventricular (RV) failure on postoperative outcomes remain limited. We hypothesized that echocardiographic findings of RV dilation and dysfunction are associated with adverse clinical outcomes after renal transplant.
METHODS: A retrospective review of adult renal transplant recipients at a single institution from January 2008 to June 2010 was conducted. Patients with transthoracic echocardiograms (TTEs) within 1 year leading up to transplant were included. The primary end point was a composite of delayed graft function, graft failure, and all-cause mortality.
RESULTS: Eighty patients were included. Mean follow-up time was 9.4 ± 0.8 years. Eight patients (100%) with qualitative RV dysfunction met the primary end point, while 39/65 patients (60.0%) without RV dysfunction met the end point (p = 0.026). Qualitative RV dilation was associated with a significantly shorter time to all-cause graft failure (p = 0.03) and death (p = 0.048). RV systolic pressure was not measurable in 45/80 patients (56%) and was not associated with outcomes in the remaining patients.
CONCLUSION: RV dilation and dysfunction are associated with adverse outcomes after renal transplant. TTE assessment of RV size and function should be a standard part of the pre-kidney transplant cardiovascular risk assessment
Immersive Trajectory Design Framework Using Augmented Reality
The field of astrodynamics currently relies on highly specialized tools for spacecraft trajectory design, resulting in intricate trajectories sometimes difficult to visualize on 2D screens. On the other hand, the intuitive interaction capabilities of augmented reality make it ideal for solving complex 3D problems that require complex spatial representations, which is key for astrodynamics and space mission planning. By implementing common and complex orbital mechanics algorithms in augmented reality, a hands-on method for designing orbit solutions and spacecraft missions is created. This effort explores the aforementioned implementation with the Microsoft Hololens 2 as well as its applications in both industry and academia. Furthermore, the collaboration between the Human Factors and Aerospace Engineering departments led to the creation of a user-friendly augmented reality system tailored for space mission planning. A user-centered design approach was explored, which involved assessing user requirements, analyzing existing processes, prototyping an AR interface, and engaging in iterative design. Moving forward, the team plans to refine and test the application\u27s front-end design through heuristic evaluations, ongoing refinement, and testing of prototypes with potential users. This is all in hopes of ensuring that the tool is user-friendly, while maintaining accuracy and applicability to higher-fidelity problems
Hipotiroidismo y esteatosis hepática
La infiltraciĂłn grasa es una condiciĂłn en la que se produce depĂłsito de lĂpidos en el citoplasma de los hepatocitos y se presenta en una serie de patologĂas entre las que podemos mencionar el hipotiroidismo. Entre los objetivos del presente estudio está el establecer la presencia de daño hepático en pacientes con disfunciĂłn tiroidea, incluir dentro del rastreo inicial de todo paciente hipotiroideo el estudio de enzimas hepáticas e instaurar la ecosonografĂa abdominal como auxiliar diagnĂłstico en pacientes con alto Ăndice de sospecha de esteatosis hepática.Las estadĂsticas a nivel mundial promedian entre un 25 y 30% de frecuencia de infiltraciĂłn grasa hepática en el hipotiroidismo. En nuestros resultados lo más relevante fue ver que el 31.25% de nuestro universo padecĂa de este problema, lo cual concuerda con las cifras arrojadas en otros estudios mĂ©dicos realizados.Podemos concluir además que debe ser parte del protocolo de seguimiento en todo paciente hipotiroideo, el estudio de la funciĂłn hepática, con el afán de evitar o controlar la progresiĂłn de la esteatosis hepática si llegara a estar presente
Divergent drivers of leaf trait variation within species, among species, and among functional groups
Understanding variation in leaf functional traits—including rates of photosynthesis and respiration and concentrations of nitrogen and phosphorus—is a fundamental challenge in plant ecophysiology. When expressed per unit leaf area, these traits typically increase with leaf mass per area (LMA) within species but are roughly independent of LMA across the global flora. LMA is determined by mass components with different biological functions, including photosynthetic mass that largely determines metabolic rates and contains most nitrogen and phosphorus, and structural mass that affects toughness and leaf lifespan (LL). A possible explanation for the contrasting trait relationships is that most LMA variation within species is associated with variation in photosynthetic mass, whereas most LMA variation across the global flora is associated with variation in structural mass. This hypothesis leads to the predictions that (i) gas exchange rates and nutrient concentrations per unit leaf area should increase strongly with LMA across species assemblages with low LL variance but should increase weakly with LMA across species assemblages with high LL variance and that (ii) controlling for LL variation should increase the strength of the above LMA relationships. We present analyses of intra- and interspecific trait variation from three tropical forest sites and interspecific analyses within functional groups in a global dataset that are consistent with the above predictions. Our analysis suggests that the qualitatively different trait relationships exhibited by different leaf assemblages can be understood by considering the degree to which photosynthetic and structural mass components contribute to LMA variation in a given assemblage
Reconstructing genome evolution in historic samples of the Irish potato famine pathogen
Responsible for the Irish potato famine of 1845–49, the oomycete pathogen Phytophthora infestans caused persistent, devastating outbreaks of potato late blight across Europe in the 19th century. Despite continued interest in the history and spread of the pathogen, the genome of the famine-era strain remains entirely unknown. Here we characterize temporal genomic changes in introduced P. infestans. We shotgun sequence five 19th-century European strains from archival herbarium samples—including the oldest known European specimen, collected in 1845 from the first reported source of introduction. We then compare their genomes to those of extant isolates. We report multiple distinct genotypes in historical Europe and a suite of infection-related genes different from modern strains. At virulence-related loci, several now-ubiquitous genotypes were absent from the historical gene pool. At least one of these genotypes encodes a virulent phenotype in modern strains, which helps explain the 20th century’s episodic replacements of European P. infestans lineages
Volume 10
Introduction Dr. Roger A. Byrne
An Analysis of Media Framing in Cases of Violence Against Women by Taylor Hogg
Writing in the Discipline of Nursing by Tiffany Carter
Photography by Brandyn Johnson
The Hidden Life of Beef Cattle: A Study of Cattle Welfare on Traditional Ranches and Industrial Farms by Haleigh James
Bloodworth\u27s by Josh Baker and Tyler Cernak
Prosimians: Little Bodies, Big Significance by Kirsten Bauer
Skinformed by Allie Snavely
Coopertition and Gracious Professionalism: The Effects of First Robotics Folklore and Culture on the Stem Community by Mary Zell Galen
Tilt by Eric Powell And Thomas Wise
The Millennial Generation and Protest Politics: How Social Media Affects Civic Engagement by Katie Kinsey
Effects of Intergenerational Daycares: Parents\u27 Perception of Early Childhood Socialization with Elderly Populations by Beth Barbolla, Maeleigh Ferlet, Rebecca Morra
Speech and Intelligence: Does My Use of AAE Label Me Incompetent? By Michala Day
Stimulation of Dendritic Cells with Dimethylfumarate Leads to Cd-4 Th2 T-Cells Immune Responses in Multiple Sclerosis and Psoriasis by Alexandra Evangelista, Max Flores, Harley Hodges, and Clardene Jones
The Hunt by Harrison Samaniego
The Rise of Structural Individualism: Millennial Attitudes Towards Welfare and Poverty by Jamesha Watson
A Rhetorical Analysis of Pope Francis\u27s Address to U.S. Congress on September 24, 2015: A Petition for the Revival of Community and Common Values by Abby Gargiulo
Photomontage Poster by Heather Green
Love You to Death: Repressed Desires in Poe\u27s The Black Cat by Haley Klepatzki
Muhammad Ali by Juan Guevara
No end to it, baby : Pynchon, Communication, and The Crying of Lot 49 by Dani Bondurant
The Sun Has Set on Britain By Michael Joseph Link, Jr.
The Handbettering Campaign by Pamela Dahl
Ceremony Marks FDR\u27s Continuance as Leader as War Goes On: An Analysis Of FDR\u27s Fourth Inauguration and How It Reflected the Effect of the War in American Society by Maeve Losen
How White Is for Witching and Get Out Challenge Western Xenophobia by Charlotte Murphe
Size and Shape Constraints of (486958) Arrokoth from Stellar Occultations
We present the results from four stellar occultations by (486958) Arrokoth, the flyby target of the New Horizons extended mission. Three of the four efforts led to positive detections of the body, and all constrained the presence of rings and other debris, finding none. Twenty-five mobile stations were deployed for 2017 June 3 and augmented by fixed telescopes. There were no positive detections from this effort. The event on 2017 July 10 was observed by the Stratospheric Observatory for Infrared Astronomy with one very short chord. Twenty-four deployed stations on 2017 July 17 resulted in five chords that clearly showed a complicated shape consistent with a contact binary with rough dimensions of 20 by 30 km for the overall outline. A visible albedo of 10% was derived from these data. Twenty-two systems were deployed for the fourth event on 2018 August 4 and resulted in two chords. The combination of the occultation data and the flyby results provides a significant refinement of the rotation period, now estimated to be 15.9380 ± 0.0005 hr. The occultation data also provided high-precision astrometric constraints on the position of the object that were crucial for supporting the navigation for the New Horizons flyby. This work demonstrates an effective method for obtaining detailed size and shape information and probing for rings and dust on distant Kuiper Belt objects as well as being an important source of positional data that can aid in spacecraft navigation that is particularly useful for small and distant bodies.Fil: Buie, Marc W.. Southwest Research Institute.; Estados UnidosFil: Porter, Simon B.. Southwest Research Institute.; Estados UnidosFil: Tamblyn, Peter. Southwest Research Institute.; Estados UnidosFil: Terrell, Dirk. Southwest Research Institute.; Estados UnidosFil: Parker, Alex Harrison. Southwest Research Institute.; Estados UnidosFil: Baratoux, David. GĂ©osciences Environnement Toulouse; Francia. Centre National de la Recherche Scientifique; FranciaFil: Kaire, Maram. Ministry of Higher Education Research and Innovation; Senegal. AsociaciĂłn Senegalesa para la PromociĂłn de la AstronomĂa; SenegalFil: Leiva, Rodrigo. Southwest Research Institute.; Estados UnidosFil: Verbiscer, Anne J.. University of Virginia; Estados UnidosFil: Zangari, Amanda M.. Southwest Research Institute.; Estados UnidosFil: Colas, François. Centre National de la Recherche Scientifique. Observatoire de Paris; Francia. Sorbonne University; Francia. Centre National de la Recherche Scientifique; FranciaFil: Diop, Baidy Demba. Direction de la Formation et de la Communication; SenegalFil: Samaniego, Joseph I.. University of Colorado; Estados UnidosFil: Wasserman, Lawrence H.. Lowell Observatory; Estados UnidosFil: Benecchi, Susan D.. Planetary Science Institute; Estados UnidosFil: Caspi, Amir. Southwest Research Institute.; Estados UnidosFil: Gwyn, Stephen. Herzberg Astronomy and Astrophysics Research Centre; CanadáFil: Kavelaars, J. J.. Herzberg Astronomy and Astrophysics Research Centre; CanadáFil: Ocampo UrĂa, Adriana C.. National Aeronautics and Space Administration; Estados UnidosFil: Rabassa, Jorge Oscar. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro Austral de Investigaciones CientĂficas; ArgentinaFil: Skrutskie, M. F.. University of Virginia; Estados UnidosFil: Soto, Alejandro. Southwest Research Institute.; Estados UnidosFil: Tanga, Paolo. UniversitĂ© CĂ´te d’Azur; Francia. Centre National de la Recherche Scientifique; FranciaFil: Young, Eliot F.. Southwest Research Institute.; Estados UnidosFil: Stern, S. Alan. Southwest Research Institute.; Estados UnidosFil: Andersen, Bridget C.. University of Virginia; Estados UnidosFil: Arango PĂ©rez, Mauricio E.. Universidad de Antioquia; ColombiaFil: Arredondo, Anicia. Massachusetts Institute of Technology; Estados UnidosFil: Artola, Rodolfo Alfredo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto de AstronomĂa TeĂłrica y Experimental. Universidad Nacional de CĂłrdoba. Observatorio AstronĂłmico de CĂłrdoba. Instituto de AstronomĂa TeĂłrica y Experimental; ArgentinaFil: GarcĂa Migani, Esteban AndrĂ©s. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, FĂsicas y Naturales. Departamento de GeofĂsica y AstronomĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - San Juan; Argentin
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