1,563 research outputs found

    Modification of Caloris ejecta blocks by long-lived mass-wasting: A volatile-driven process?

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    The Caloris basin is the largest well-preserved impact basin on Mercury. As such, Caloris ejecta afford us an opportunity to study material from Mercury’s deep interior with remote sensing. We have made observations of the geomorphology, colour, distribution, and flank slopes of the circum-Caloris knobs. Our observations suggest that these circum-Caloris knobs are modified ejecta blocks from the Caloris impact. High-resolution MESSENGER images show that knobs are conical and relatively uncratered compared with the surrounding plains, which implies the knobs have undergone resurfacing. We have observed material that has sloughed off knobs superposing impact craters that demonstrably postdate the Caloris impact, which requires some knob modification to have been more recent. We have observed hollows, depressions in Mercury’s surface generally believed to have been caused by volatile-loss, on and closely associated with several knobs, which indicates that many knobs contain volatile material and that knob modification could extend into Mercury’s recent past. Our measurements show that knob flanks typically have slopes of ∼21°, which is steep for a mound of unconsolidated material that was originally emplaced ∼3.8 Ga. The conical shape of knobs, their steep slopes, the dearth of superposed craters on knobs, and knob superposition relationships with other landforms suggest that Caloris ejecta blocks of arbitrary original shape were modified into their present shapes by long-lived mass-wasting. Mass-wasting must have dominated over impact gardening, which would have produced domal morphologies only. We suggest that mass-wasting was probably driven by volatile-loss, in a manner analogous to terrestrial landforms called ‘molards’. If the circum-Caloris knobs are analogous to molards, then they represent a landform and a process hitherto undocumented on Mercury, with implications for the volatile content of the planet’s interior. These knobs therefore are prime targets for BepiColombo, which could search for fresh failures and volatile exposures in the knobs

    Pharmacist Empathy in Smoking Cessation Counseling

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    Cigarette smoking and nicotine addiction are prevalent in today’s society. Approximately 19% of American adults (43.8 million people) smoke cigarettes. Smoking is associated with health risks such as Chronic Obstructive Pulmonary Disease (COPD), infertility, low birth weight, respiratory symptoms, heart disease, and lung cancer and is responsible for roughly $96 billion in health care costs. Provider empathy has been proven effective in other treatments like cold and cancer; however, its effectiveness in smoking cessation has not yet been studied. Empathy is defined in two realms: cognitive and affective. In the cognitive domain, individuals have the ability to understand and view the world from another’s perspective, and in the affective domain, they can connect to the experiences or feelings of others. The twofold objective of this study is (1) to validate a modified Kiersma-Chen Empathy Scale to measure patient perceptions of provider empathy and (2) to determine if patients who view their pharmacists as empathetic achieve a higher quit rate in smoking cessation. The original Kiersma-Chen Empathy Scale is a previously-validated measure of provider empathy. Patients who are utilizing smoking cessation clinical services and meet inclusion criteria and whose quit date was at least 6 months prior, will complete three surveys 6 months after their quit date. The surveys conducted will measure patient demographics, quit status, and the patient’s perceptions of their pharmacist’s empathy (modified KCES). The collected data will be analyzed via a psychometric test to show the validity of the modified empathy scale and via a Spearman correlation to demonstrate the association between provider empathy and smoking cessation rates. The results of this study will provide beneficial information about how pharmacist’s can best assist their patients in smoking cessation, specifically regarding the empathy shown to the patient

    Muscle Activated 3D Printed Prosthetic Arm

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    Due to the rapid growth of children and the cost of myoelectric technology, children are not given the same opportunities to use myoelectric prosthetics as adults. The Muscle Activated Prosthesis (MAP) team seeks to reconcile this by creating an affordable, trans-radial, myoelectric prosthesis that utilizes the flexibility of 3D printing technology for a fourteen-year-old congenital amputee named Lily. The MAP team has completed the design and prototype of a myoelectric prosthesis with a material cost of approximately 1,000asopposedtothe1,000 as opposed to the 10,000-$20,000 cost of clinically accepted myoelectric prosthetic upper limbs. The 3D printed prosthetic arm prototype incorporates electromyography (EMG) electrodes, a motor and tendon system, an open-source prosthetic hand design, a custom printed circuit board (PCB), and lithium-ion battery power. The opening and closing of the prosthetic hand is controlled by the myoelectric signals from the user’s forearm contractions which can be tested by the team using our adaptive prosthetic attachment. All these components result in an affordable prosthetic that has the potential for customization and adaptation to different sized limbs. Funding for this work provided by The Collaboratory for Strategic Partnerships and Applied Research.https://mosaic.messiah.edu/engr2022/1009/thumbnail.jp

    TOI-3785 b: A Low-Density Neptune Orbiting an M2-Dwarf Star

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    Using both ground-based transit photometry and high-precision radial velocity (RV) spectroscopy, we confirm the planetary nature of TOI-3785 b. This transiting Neptune orbits an M2-Dwarf star with a period of ~4.67 days, a planetary radius of 5.14 +/- 0.16 Earth Radii, a mass of 14.95 +4.10, -3.92 Earth Masses, and a density of 0.61 +0.18, -0.17 g/cm^3. TOI-3785 b belongs to a rare population of Neptunes (4 Earth Radii < Rp < 7 Earth Radii) orbiting cooler, smaller M-dwarf host stars, of which only ~10 have been confirmed. By increasing the number of confirmed planets, TOI-3785 b offers an opportunity to compare similar planets across varying planetary and stellar parameter spaces. Moreover, with a high transmission spectroscopy metric (TSM) of ~150 combined with a relatively cool equilibrium temperature of 582 +/- 16 K and an inactive host star, TOI-3785 b is one of the more promising low-density M-dwarf Neptune targets for atmospheric follow-up. Future investigation into atmospheric mass loss rates of TOI-3785 b may yield new insights into the atmospheric evolution of these low-mass gas planets around M-dwarfs.Comment: 22 pages, 6 figures, 6 tables, Submitted to A

    TOI-1728b: The Habitable-zone Planet Finder confirms a warm super Neptune orbiting an M dwarf host

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    We confirm the planetary nature of TOI-1728b using a combination of ground-based photometry, near-infrared Doppler velocimetry and spectroscopy with the Habitable-zone Planet Finder.TOI-1728 is an old, inactive M0 star with \teff{} =398032+31= 3980^{+31}_{-32} K, which hosts a transiting super Neptune at an orbital period of \sim 3.49 days. Joint fitting of the radial velocities and TESS and ground-based transits yields a planetary radius of 5.050.17+0.165.05_{-0.17}^{+0.16} R_{\oplus}, mass 26.785.13+5.4326.78_{-5.13}^{+5.43} M_{\oplus} and eccentricity 0.0570.039+0.0540.057_{-0.039}^{+0.054}. We estimate the stellar properties, and perform a search for He 10830 \AA absorption during the transit of this planet and claim a null detection with an upper limit of 1.1%\% with 90\% confidence. A deeper level of He 10830 \AA ~ absorption has been detected in the planet atmosphere of GJ 3470b, a comparable gaseous planet. TOI-1728b is the largest super Neptune -- the intermediate subclass of planets between Neptune and the more massive gas-giant planets -- discovered around an M dwarf. With its relatively large mass and radius, TOI-1728 represents a valuable datapoint in the M-dwarf exoplanet mass-radius diagram, bridging the gap between the lighter Neptune-sized planets and the heavier Jovian planets known to orbit M-dwarfs. With a low bulk density of 1.140.24+0.261.14_{-0.24}^{+0.26} g/cm3^3, and orbiting a bright host star (J 9.6\sim 9.6, V 12.4\sim 12.4), TOI-1728b is also a promising candidate for transmission spectroscopy both from the ground and from space, which can be used to constrain planet formation and evolutionary models.Comment: 21 pages, 12 figures, 4 tables: Accepted for publicatio

    TOI-1728b: The Habitable-zone Planet Finder Confirms a Warm Super-Neptune Orbiting an M-dwarf Host

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    We confirm the planetary nature of TOI-1728b using a combination of ground-based photometry, near-infrared Doppler velocimetry and spectroscopy with the Habitable-zone Planet Finder. TOI-1728 is an old, inactive M0 star with T_(eff) = 3980⁺³¹₋₃₂ K, which hosts a transiting super-Neptune at an orbital period of ~3.49 days. Joint fitting of the radial velocities and TESS and ground-based transits yields a planetary radius of 5.05^(+0.16)_(-0.17) R_⊕, mass 26.78^(+5.43)_(-5.13) M_⊕, and eccentricity 0.057^(+0.054)_(-0.039). We estimate the stellar properties, and perform a search for He 10830 Å absorption during the transit of this planet and claim a null detection with an upper limit of 1.1% with 90% confidence. A deeper level of He 10830 Å absorption has been detected in the planet atmosphere of GJ 3470b, a comparable gaseous planet. TOI-1728b is the largest super-Neptune—the intermediate subclass of planets between Neptune and the more massive gas-giant planets—discovered around an M dwarf. With its relatively large mass and radius, TOI-1728 represents a valuable data point in the M-dwarf exoplanet mass–radius diagram, bridging the gap between the lighter Neptune-sized planets and the heavier Jovian planets known to orbit M dwarfs. With a low bulk density of 1.14^(+0.26)_(-0.24) g cm⁻³, and orbiting a bright host star (J ~ 9.6, V ~ 12.4), TOI-1728b is also a promising candidate for transmission spectroscopy both from the ground and from space, which can be used to constrain planet formation and evolutionary models

    The Habitable Zone Planet Finder Reveals a High Mass and Low Obliquity for the Young Neptune K2-25b

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    Using radial velocity data from the Habitable Zone Planet Finder, we have measured the mass of the Neptune-sized planet K2-25b, as well as the obliquity of its M4.5 dwarf host star in the 600–800 Myr Hyades cluster. This is one of the youngest planetary systems for which both of these quantities have been measured and one of the very few M dwarfs with a measured obliquity. Based on a joint analysis of the radial velocity data, time-series photometry from the K2 mission, and new transit light curves obtained with diffuser-assisted photometry, the planet's radius and mass are 3.44 ± 0.12 R_⊕ and 24.5_(-5.2)^(+5.7) M_⊕. These properties are compatible with a rocky core enshrouded by a thin hydrogen–helium atmosphere (5% by mass). We measure an orbital eccentricity of e = 0.43 ± 0.05. The sky-projected stellar obliquity is λ = 3° ± 16°, compatible with spin–orbit alignment, in contrast to other "hot Neptunes" that have been studied around older stars

    The Habitable-zone Planet Finder Reveals A High Mass and a Low Obliquity for the Young Neptune K2-25b

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    Using radial-velocity data from the Habitable-zone Planet Finder, we have measured the mass of the Neptune-sized planet K2-25b, as well as the obliquity of its M4.5-dwarf host star in the 600-800MYr Hyades cluster. This is one of the youngest planetary systems for which both of these quantities have been measured, and one of the very few M dwarfs with a measured obliquity. Based on a joint analysis of the radial velocity data, time-series photometry from the K2 mission, and new transit light curves obtained with diffuser-assisted photometry, the planet's radius and mass are 3.44±0.12R3.44\pm 0.12 \mathrm{R_\oplus} and 24.55.2+5.7M24.5_{-5.2}^{+5.7} \mathrm{M_\oplus}. These properties are compatible with a rocky core enshrouded by a thin hydrogen-helium atmosphere (5% by mass). We measure an orbital eccentricity of e=0.43±0.05e=0.43 \pm 0.05. The sky-projected stellar obliquity is λ=3±16\lambda=3 \pm 16^{\circ}, compatible with spin-orbit alignment, in contrast to other "hot Neptunes" that have been studied around older stars.Comment: Accepted for publication in AJ, 31 pages, 14 figure

    TOI-4201: An Early M-dwarf Hosting a Massive Transiting Jupiter Stretching Theories of Core-Accretion

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    We confirm TOI-4201 b as a transiting Jovian mass planet orbiting an early M dwarf discovered by the Transiting Exoplanet Survey Satellite. Using ground based photometry and precise radial velocities from NEID and the Planet Finder Spectrograph, we measure a planet mass of 2.590.06+0.07^{+0.07}_{-0.06} MJ_{J}, making this one of the most massive planets transiting an M-dwarf. The planet is \sim0.4\% the mass of its 0.63 M_{\odot} host and may have a heavy element mass comparable to the total dust mass contained in a typical Class II disk. TOI-4201 b stretches our understanding of core-accretion during the protoplanetary phase, and the disk mass budget, necessitating giant planet formation to either take place much earlier in the disk lifetime, or perhaps through alternative mechanisms like gravitational instability.Comment: To be submitted to AAS journals on 14th July 202
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