Abstract
Mature super-Earths and sub-Neptunes are predicted to be ≃ Jovian radius when younger than 10 Myr. Thus, we expect to find 5–15
R
⊕
planets around young stars even if their older ...counterparts harbor none. We report the discovery and validation of TOI 1227b, a 0.85 ± 0.05
R
J
(9.5
R
⊕
) planet transiting a very-low-mass star (0.170 ± 0.015
M
⊙
) every 27.4 days. TOI 1227's kinematics and strong lithium absorption confirm that it is a member of a previously discovered subgroup in the Lower Centaurus Crux OB association, which we designate the Musca group. We derive an age of 11 ± 2 Myr for Musca, based on lithium, rotation, and the color–magnitude diagram of Musca members. The TESS data and ground-based follow-up show a deep (2.5%) transit. We use multiwavelength transit observations and radial velocities from the IGRINS spectrograph to validate the signal as planetary in nature, and we obtain an upper limit on the planet mass of ≃0.5
M
J
. Because such large planets are exceptionally rare around mature low-mass stars, we suggest that TOI 1227b is still contracting and will eventually turn into one of the more common <5
R
⊕
planets.
Necrotising otitis externa is a serious infective condition. Patients are typically frail, diagnostic delay is common and severe pain is a key feature. This study aimed to qualitatively analyse ...patient-centred data to identify key themes in the patient's experience.
Open-ended questionnaires were sent to 28 patients. Responses were qualitatively analysed using a grounded theory approach. Iterative cycles were used to develop codes using a constant comparison technique. Emerging categories were refined to identify core themes.
Four main themes emerged: severe pain, mental health, quality of life and diagnostic delays.
This is the first study to explore patients' perspectives in necrotising otitis externa. It indicates a need to raise awareness of necrotising otitis externa, and to improve symptom management, pain control and quality of life. This valuable information can be used to identify research priorities, guide service improvements, improve clinical care and feed into the development of a Core Outcome Set for necrotising otitis externa.
At this time of social flux, of changing demographics on campus and the world beyond, of recognition of intersectional identities, as well as the wide variety of aspirations and career goals of ...today's women undergraduates, how can colleges and universities best prepare them for the demands of modern leadership? This text speaks to the changing context of today's women students' experiences, recognizing that their work life goals may go beyond climbing the corporate ladder to include social innovation and entrepreneurial goals, policy and politics, and social activism. This book is a product of multiple collaborations and intellectual contributions of a diverse group of undergraduate and graduate women who helped shape the course on which it is based. They provided research support, critical readings, as well as the diverse narratives that are included throughout the book, not as an ideal for readers to aspire to but as an authentic expression of how their distinct and sometimes non-conforming lived experiences shaped their understandings of leadership. It goes beyond hero/she-ro person-centered approaches to get at the complex and intrapersonal nature of leadership. It also situates intersectional identities, critical consciousness, and student development theory as important lenses throughout the text. Recognizing that there are many possible manifestations of leadership or gender, this text encourages students to embrace the contradictions rather than engaging in dualistic, black-and-white thinking, challenging them to address such questions as, Should women "lean in" and work harder to achieve their own leadership goals, or should they focus on bigger systemic issues to create equity in the workplace? Each chapter concludes with a brief chapter review, a narrative from a current college student, and critical reflection questions.
Abstract
Theoretical models indicate that photoevaporative and magnetothermal winds play a crucial role in the evolution and dispersal of protoplanetary disks and affect the formation of planetary ...systems. However, it is still unclear what wind-driving mechanism is dominant or if both are at work, perhaps at different stages of disk evolution. Recent spatially resolved observations by Fang et al. of the O
i
6300 Å spectral line, a common disk wind tracer in TW Hya, revealed that about 80% of the emission is confined to the inner few astronomical units of the disk. In this work, we show that state-of-the-art X-ray-driven photoevaporation models can reproduce the compact emission and the line profile of the O
i
6300 Å line. Furthermore, we show that the models also simultaneously reproduce the observed line luminosities and detailed spectral profiles of both the O
i
6300 Å and the Ne
ii
12.8
μ
m lines. While MHD wind models can also reproduce the compact radial emission of the O
i
6300 Å line, they fail to match the observed spectral profile of the O
i
6300 Å line and underestimate the luminosity of the Ne
ii
12.8
μ
m line by a factor of 3. We conclude that, while we cannot exclude the presence of an MHD wind component, the bulk of the wind structure of TW Hya is predominantly shaped by a photoevaporative flow.
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The electrification of public transit is one of the key actions in the transportation sector. This study proposed an innovative framework for analyzing the effectiveness and emission ...reduction potential of electrifying transit policies. The future energy consumption, GHG emissions, and pollutant emissions of bus fleets in representative Canadian cities were analyzed. Under the high oil price scenarios, this study incorporated the upfront infrastructure costs, the social costs of pollution, and the dynamics of carbon prices and fuel prices, allowing for a comprehensive analysis of carbon reduction costs during transition. Compared to the BAU scenarios, the cumulative GHG emissions from 2019 to 2030 of bus fleet in ESD scenarios in Toronto, Montreal, Edmonton, and Halifax had a reduction of 18.7 %, 30.1 %, 21.3 % and 34.6 %, respectively. The findings have implications for the trade-off management of climate policies at the provincial level and can help understand polycentric governance from multiple resource perspectives.
Active school travel (AST) is promoted in many jurisdictions, including Ontario, Canada, where there is provincial support for school travel planning (STP) efforts. Two pillars of school travel plans ...in the province are education and encouragement. For these pillars to stand, relevant stakeholders must be cognizant of and understand the issues and stakes. For this reason, we deem it important to understand how AST is communicated. In this research we adopt framing analysis to investigate the ways in which various organizations communicate to the public around AST. A frame is a central organizing idea or story line that provides meaning to a particular phenomenon, and thus helps to set the parameters for conversations about policy. In the case of AST, framing can influence what policy alternatives are perceived as available by children, parents, and their wider communities. The research is supported by natural language processing techniques applied to publicly available documents from Ontario stakeholders involved in school travel planning. We then compare the findings from these documents to a selection of academic studies on AST. We conclude that framing of AST in Ontario is mostly empirical-scientific in style, and largely in agreement with academic research on AST. However, it is essentially conservative and does not challenge the status quo of motorized travel. Furthermore, the frames tend to download responsibility for change to households, which limits the scope of policy alternatives by keeping collective action out of the frame.
Abstract Objective This study aims to evaluate the feasibility and potential effectiveness of two approaches to using the PTSD Coach mobile application in primary care: Self-Managed PTSD Coach and ...Clinician-Supported PTSD Coach. This study also aims to gather preliminary data to investigate if clinician support improves the benefits of using PTSD Coach on posttraumatic stress disorder (PTSD) severity and specialty mental healthcare utilization. Method Twenty primary care veterans with PTSD symptoms were randomized to either Self-Managed PTSD Coach consisting of one 10-min session providing instructions for application use or Clinician-Supported PTSD Coach consisting of four 20-min sessions focused on setting symptom reduction goals and helping veterans fully engage with application content. Results Research procedures and intervention conditions appear feasible as indicated by high rates of assessment and intervention retention and high clinician fidelity and satisfaction. Both treatments resulted in reductions in PTSD symptoms, with 7 Clinician-Supported PTSD Coach and 3 Self-Managed PTSD Coach participants reporting clinically significant improvements. Clinician-Supported PTSD Coach resulted in more specialty PTSD care use postintervention and possibly greater reductions in PTSD symptoms. Conclusions Both PTSD Coach interventions are feasible and potentially helpful. The addition of clinician support appears to increase the effectiveness of self-management alone. A larger-scale randomized controlled trial is warranted to confirm these encouraging preliminary findings.
Snow lines can be thermally unstable Owen, James E
Monthly notices of the Royal Astronomical Society,
07/2020, Letnik:
495, Številka:
3
Journal Article
Recenzirano
Odprti dostop
ABSTRACT
Volatile species in protoplanetary discs can undergo a phase change from vapour to solid. These ‘snow lines’ can play vital roles in planet formation at all scales, from dust coagulation to ...planetary migration. In the outer regions of protoplanetary discs, the temperature profile is set by the absorption of reprocessed stellar light by the solids. Further, the temperature profile sets the distribution of solids through sublimation and condensation at various snow lines. Hence, the snow line position depends on the temperature profile and vice versa. We show that this coupling can be thermally unstable, such that a patch of the disc at a snow line will produce either runaway sublimation or condensation. This thermal instability arises at moderate optical depths, where heating by absorption of reprocessed stellar light from the disc’s atmosphere is optically thick, yet cooling is optically thin. Since volatiles in the solid phase drift much faster than volatiles in the vapour phase, this thermal instability results in a limit cycle. The snow line progressively moves in, condensing volatiles, before receding, as the volatiles sublimate. Using numerical simulations, we study the evolution of the carbon monoxide (CO) snow line. We find the CO snow line is thermally unstable under typical disc conditions and evolves inwards from ∼50 to ∼30 au on time-scales from 1000 to 10 000 yr. The CO snow line spends between ${\sim}10{{\ \rm per\ cent}}\,\mathrm{ and}\,50{{\ \rm per\ cent}}$ of its time at smaller separations, where the exact value is sensitive to the total opacity and turbulent viscosity. The evolving snow line also creates ring-like structures in the solid distribution interior to the snow line. Multiple ring-like structures created by moving snow lines could potentially explain the substructures seen in many ALMA images.
Abstract
The phase separation dynamics in graphitic anodes significantly affects lithium plating propensity, which is the major degradation mechanism that impairs the safety and fast charge ...capabilities of automotive lithium-ion batteries. In this study, we present comprehensive investigation employing operando high-resolution optical microscopy combined with non-equilibrium thermodynamics implemented in a multi-dimensional (1D+1D to 3D) phase-field modeling framework to reveal the rate-dependent spatial dynamics of phase separation and plating in graphite electrodes. Here we visualize and provide mechanistic understanding of the multistage phase separation, plating, inter/intra-particle lithium exchange and plated lithium back-intercalation phenomena. A strong dependence of intra-particle lithiation heterogeneity on the particle size, shape, orientation, surface condition and C-rate at the particle level is observed, which leads to early onset of plating spatially resolved by a 3D image-based phase-field model. Moreover, we highlight the distinct relaxation processes at different state-of-charges (SOCs), wherein thermodynamically unstable graphite particles undergo a drastic intra-particle lithium redistribution and inter-particle lithium exchange at intermediate SOCs, whereas the electrode equilibrates much slower at low and high SOCs. These physics-based insights into the distinct SOC-dependent relaxation efficiency provide new perspective towards developing advanced fast charge protocols to suppress plating and shorten the constant voltage regime.
![High-resolution [O i] Line ...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/2041-8205/small "High-resolution [O i] Line Spectral Mapping of TW Hya Consistent with X-Ray-driven Photoevaporation")
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