330 research outputs found
Novel Dialogue 5.3 It’s on The Illabus: A Discussion with Jean-Christophe Cloutier and John Jennings (SW)
No full textJohn Jennings—Hugo Award winner, New York Times bestselling author, curator, scholar, and Artist—is keenly aware that in adapting novels for the graphic format, his decisions turn what has only been imagined into facts drawn on the page. In this conversation with critic, translator, and teacher of a creative course on the art of making comics, Jean-Christophe Cloutier, Jennings explores how he makes those decisions that range from the design of endpapers to selecting a character’s skin tone with the ultimate aim of championing Black culture and Black comics. Given that Jennings has just entered the Marvel Universe with the debut of Silver Surfer: Ghost Light, the timing is right to reflect on the pressures and pleasures of adapting beloved stories for a contemporary audience. Jennings is both teacher and student of comics’ powerful lessons, and lucky for listeners, his course comes with an illustrated syllabus, aka illabus. In the podcast’s first ever episode about graphic novels, Jennings and Cloutier talk comic book history, the power of collaboration, and the importance of long showers
Essay about Great Duck Island. The author speculates about the lives of previous
No full textEssay about Great Duck Island. The author speculates about the lives of previous residents, including the psychiatrist George Cloutier, discusses the bird population of the island, and reflects on her own process of imagining and interpreting the island
Characterizing the Exoplanet Population Around Mid-to-Late M Dwarfs
No full textAround Sun-like stars and early M dwarfs alike, super-Earths and sub-Neptunes form a bimodal distribution separated by a dearth of planets between 1.6 and 1.9 Earth radii known as the radius valley. Modeling these planet populations and the radius valley have refined planet formation models but full understanding of the planet formation process requires a complete picture of the planet population extending to the lowest mass stars. As of yet, transiting exoplanet surveys have been largely insensitive to planets around mid-to-late M dwarfs. Fortunately, NASA’s Transiting Exoplanet Survey Satellite (TESS) has opened a window into the exoplanet population around mid-to-late M dwarfs. I have led a systematic search for small transiting planets around 9,131 mid-to-late M dwarfs observed by TESS to characterize the planet population. I will present my pipeline to process TESS light curves and to detect and vet signals from transiting planets. Over the set of targets, this survey recovers a population of 73 manually vetted transiting planet signals. Using injection-recovery tests, I characterize the sensitivity of my pipeline to transiting planets around stars in the sample as a function period, instellation and radius. Using the recovered planet population combined with my survey completeness, I measure an occurrence rate of 1.326(+0.210/−0.208) planets per star, with radii < 6.5R⊕ and orbital periods within 30 days dominated by a population of sub- and super-Earths with very few sub-Neptunes compared to more massive M dwarfs. This result is in agreement with previous work in this regime, while surveying a factor of 25 more stars, and aligns with theoretical predictions of the planet population. Along with our occurrence rate calculation, we provide strong evidence that the radius valley disappears in this stellar mass regime.ThesisMaster of Science (MSc)With thousands of exoplanet discoveries over the last three decades, exoplanet astronomy has revolutionized our understanding of the planet population. Successive surveys have shown that the two most common types of planets are rocky super-Earths with radii between 1 and 1.7 Earth radii and sub-Neptunes with radii spanning 2 to 5 Earth radii. Between these two populations is dearth of planets dubbed the Radius Valley. Super-Earths and sub-Neptunes are unrepresented in the solar system and models that can reproduce their population and the Radius Valley have sharpened our understanding of the planet formation process. We cannot reach a full understanding of the planet formation process without extending our understanding to the full population of planet-forming stars. The smallest of these stars are mid-to-late M dwarfs spanning from 8% to 40% the mass of our Sun and previous surveys have been largely insensitive to their planets at a population level. In this work I present my planet finding pipeline, and its deployment to survey 9,131 mid-to-late M dwarfs observed by the Transiting Exoplanet Survey Satellite (TESS) for transiting planet signals. By combining a population of 73 planets from this survey with a detailed, empirically established understanding of my pipeline's detection sensitivity to planets of various properties, this survey finds that each mid-to-late M dwarf hosts 1.3 planets within 30 days on average. This population is dominated by super-Earths, with relatively few sub-Neptunes. This result is in agreement with theoretical predictions of the planet population around the lowest mass stars and provides strong evidence that the radius valley disappears in this mass stellar regime
A Spectroscopic Framework for Deriving Elemental Abundances of M Dwarfs
No full textMeasuring accurate stellar abundances of planet-forming elements is critical to our understanding of exoplanet compositions and their formation processes. While these values can be reliably derived from optical spectra for FGK-type stars, the recovery of accurate abundances for M dwarfs is complicated due to persistent discrepancies between models and observed spectra, such as blended absorption features and broad molecular bands that obscure the continuum. These lingering uncertainties in M dwarf chemical compositions inhibit our ability to accurately model the interiors and atmospheres of exoplanets around M dwarfs. To address this issue, we have built a custom framework to extract elemental abundances from the spectra of cool stars via the spectral synthesis method. We showcase our methodology as well as the derived elemental abundances for a pair of cool stars. SPIRou, with its high spectral resolution and broad near-IR wavelength range, is the ideal instrument to help mitigate the difficulties present in the recovery of M dwarf elemental abundances. By combining the capabilities of SPIRou with our framework, we are well equipped to ensure the accuracy of derived elemental abundances in M dwarfs. Our results will ultimately be applied to planet-hosting M dwarfs in order to place strong constraints on the planets’ refractory and volatile abundances, both of which are important diagnostics of planetary formation histories and interior compositions.ThesisMaster of Science (MSc)Understanding what planets are made of helps us learn how they form. Since planets and their stars are created from the same materials, we can study a star’s composition to learn more about the planets that orbit it. Measuring the abundances of planet-forming elements like magnesium, silicon, and iron is routinely performed for Sun-like stars, but the task proves to be much more difficult for smaller, cooler stars like M dwarfs. M dwarfs are very common and host most of the super-Earths within the Milky Way that could potentially support life, so studying them is crucial. My Master’s thesis focuses on developing a method to accurately measure the elemental abundances in M dwarfs using high-resolution spectra taken at infrared wavelengths where M dwarfs emit most of their light. My work is helping to improve our understanding of the composition and formation pathways of exoplanets around M dwarfs
The White Dwarf Opportunity
No full textThe winds of M dwarf stars are poorly constrained and poorly understood. Literature values of M dwarf wind mass-loss rates span several orders of magnitude and suffer from poor number statistics, with fewer than 30 systems having well-constrained values. Stellar winds are especially important to how young planetary systems evolve, with consequences for expected exoplanet atmosphere loss, atmospheric chemistry, surface habitability, and more. While several methodologies exist for constraining stellar winds, only four have produced detections of wind mass-loss rates for M dwarf stars. One of these methodologies involves constraining the M dwarf mass-loss rate using atmospheric metal pollution of a close companion white dwarf star.
In this work, I calculate wind mass-loss rates for two M dwarf stars using this methodology. Additionally, I expand the range of systems to which this methodology can be applied. Previous studies have noted that M dwarfs in close binary systems with white dwarfs are often magnetically active. This magnetic activity produces emission lines for magnetically sensitive elements, such as calcium. Calcium is also the metal pollutant that produces the deepest optical light absorption signals in white dwarfs. In this work, I develop methodology for recovering calcium absorption equivalent widths from white dwarf stars in unresolved binaries with magnetically active M dwarfs. I apply this methodology to 56 systems, recovering 19 white dwarf calcium equivalent widths which remain in absorption within their 1 sigma uncertainty. While it is left to a future work to calculate wind rates for these systems, this methodology does significantly expand the number of close white dwarf-M dwarf binary systems for which M dwarf wind rates can be recovered.ThesisMaster of Science (MSc
Exoplanet Mass-Radius Relations Verified by the Solar System
No full textUnderstanding a planet's composition is necessary to understand its habitability. Inferring a planet's composition solely from observations of mass and radii requires the construction of planetary interior structure models. We present a new planetary interior structure model that includes significant physics excluded from previous models, such as the coexistence of many chemical species within the mantle, high pressure phase transitions of mantle materials, light elements within the planetary core and partitioning between the solid and liquid core, radiative transfer in the upper atmosphere, a prescription to calculate planetary transit radii rather than radii at a particular pressure, and more. We validate our resultant interior structure model by running forward models for the measured masses and compositions of Earth, Mars, the Moon, Venus, Mercury, and Europa. Our model produces radii and moment of inertia coefficients within 0.5% or 1 standard deviation of reality in all cases where the moment of inertia is well-constrained. In the case of a poorly-constrained moment of inertia, our model produces radii and moment of inertia coefficients within 1% or 3 standard deviations of reality. We present the resultant mass-radius curves between 0.01 and 100 Earth masses. We find that the radii of sub-Neptunes are consistent with planets made of either a few % H/He or 10s of % water, with surface temperature also playing a crucial factor. We find radii for pure Fe planets significantly systematically lower than much of the literature owing to our adoption of newer EOS. We fit power laws of the form M=R^X in a piecewise fashion with pieces being separated by changes in the state of the planetary interior: for a planet with Earth's composition, the solidification of the core at 2.25 Earth masses and onset of high pressure phases in the mantle at 3.41 Earth masses. At higher masses and core mass fractions, X becomes larger. The values of X for Earth-like and cold water worlds are within 1%. Previous values of X reported in the literature are only valid at masses below the solidification of the core.ThesisMaster of Science (MSc)Determining the materials that planets around other stars are made out of requires the construction of planetary interior structure models. In this thesis we present a new model that includes features often not included in previous models, such as: new calculations for the density of materials at high pressures, allowing multiple materials to coexist on the same layer of the planet, and transitions of materials between different structures. We verify that our model is accurate by comparing it to the size of Earth, Mars, the Moon, Venus, Mercury, and Europa (a moon of Jupiter). We also compare our model to a number representing how the mass inside a planet is distributed. We generally get numbers with <0.5% error. We create graphs using our model for the sizes of planets with different compositions and masses. These graphs can be compared to the measured masses and sizes of planets to guess their compositions
A Model of Regulatory Burden in Technology Diffusion: The Case of Plant-Derived Vaccines.
No full textPlant-derived vaccines may soon displace conventional vaccines. Assuming there are no major technological barriers undermining the feasibility of this innovative technology, it is worthwhile to generate quantitative models of regulatory burden of producing and diffusing plant-derived vaccines in industrialized and developing countries. A dynamic simulation model of technology diffusion—and the data to populate it—has been generated for studying regulatory barriers in the diffusion of plant-derived vaccines. The role of regulatory burden is evaluated for a variety of scenarios in which plant-derived vaccines are produced and diffused. This model relates the innovative and conventional vaccine technologies and the effects of the impact of the uptake of the innovative technology on mortality and morbidity. This case study demonstrates how dynamic simulation models can be used to assess the long-term potential impact of novel technologies in terms of a variety of socio-economic indicators.dynamic simulation model; plant-derived vaccines; regulatory burden; technology transfer; vaccines;
Chapter House: A Vision for a Sustainable Future
No full textabstract: Since the the Long Walks of the 1860’s Navajo people have wrestled with the problems of acculturation and assimilation, while trying to preserve their spiritual and cultural foundations. Though history has negatively affected Navajo wellbeing (happiness), sustainable Navajo principles and practices act as a positive counterweight.
Aspiring to build the most socially and environmentally sustainable chapter house possible, the Navajo Nation’s Tonalea Chapter collaborated with our ASU research team. Two roundtable discussion with Chapter elders and members, led to a vision foundation that embodies physical, functional and environmental conditions, as well as cultural and spiritual beliefs and values.
Initially, Houde’s (2007) Six Faces of Traditional Ecological Knowledge (TEK) were used to sort commentary. Analysis and review led to expanding the framework from six to eight traditional ecological knowledge categories (TEK8): Culture, Spirituality, Ecosystem, Time, Land, Design, Social Justice and Equity, and Economics.
Sorted narratives and discussions revealed traditional ways of life, beliefs, and values, along with suggestions about who to design for, and what functions are most needed. Based on the TEK8 categorized comments, design recommendations were offered.
Additional work is needed, but a strong foundation for a framework mapping TEK to sustainable design for indigenous people has been developed. By using the TEK8 to address social justice issues through participatory visioning, culturally appropriate design and broader opportunities for happiness may result
As Kings Become Pawns (Book Review: Cloutier, P. Three Kings: Axis Royal Armies on the Russian Front 1941 [Text] / P. Cloutier. – Charleston, SC : Createspace Independing Publishing Platform, 2015. – 160 p.)
No full textThe publication is a review of the American historian P. Cloutier’s book devoted to the participation of such satellite states of Nazi Germany, like Hungary, Italy and Romania in the war against the Soviet Union. Based on a wide complex of historical sources and literature, P. Cloutier managed to reconstruct a holistic history of the Hungarian, Italian and Romanian armed forces in the Eastern front from June to December 1941. The reasons and background of the participation of Hungary, Italy and Romania in the military efforts of Nazi Germany, as well as the objects pursued by their military and political leaders is analyzed. The main stages and series of events of combat using of military units and formations of the representatives of these countries, mainly in the southern sector of the Eastern front are examined. The author rightly shows that from a quantitative point of view, the contribution of the Hungarian, Italian and Romanian armed forces was considerable. However, due to a number of reasons, this contribution is not of high quality. The German command, in whole, poorly assessed their combat qualities, preferring to use the Hungarians, Italians and Romanians together with the units and formations of the Wehrmacht. P. Cloutier’s concept, source base, facts, the scientific apparatus and methodology allow us to conclude that his monograph is a major contribution to the historiography of the World War II
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