Simulations of propelling and energy harvesting articulated bodies via vortex particle-mesh methods

The emergence and understanding of new design paradigms that exploit flow induced mechanical instabilities for propulsion or energy harvesting demands robust and accurate flow structure interaction numerical models. In this context, we develop a novel two dimensional algorithm that combines a Vortex Particle-Mesh (VPM) method and a Multi-Body System (MBS) solver for the simulation of passive and actuated structures in fluids. The hydrodynamic forces and torques are recovered through an innovative approach which crucially complements and extends the projection and penalization approach of Coquerelle et al. and Gazzola et al. The resulting method avoids time consuming computation of the stresses at the wall to recover the force distribution on the surface of complex deforming shapes. This feature distinguishes the proposed approach from other VPM formulations. The methodology was verified against a number of benchmark results ranging from the sedimentation of a 2D cylinder to a passive three segmented structure in the wake of a cylinder. We then showcase the capabilities of this method through the study of an energy harvesting structure where the stocking process is modeled by the use of damping elements

Alien Registration- Bernier, Caroline (Lewiston, Androscoggin County)

https://digitalmaine.com/alien_docs/29379/thumbnail.jp

Sine wave in music and sound art : a typology of artistic approaches

Project : Towards an Aesthetics of the Sine Wave Chercheur.e.s : Nicolas Bernier, Guillaume Boutard, Caroline TraubeDespite the sine wave’s close links to the birth of electronic music in the mid-twentieth century, it has been little studied aesthetically, and no systematic review of its artistic usages exists. This article presents a brief literature review, followed by the results of a survey on the principles guiding sine wave-based works. This allows to put forward a typological framework contributing to an understanding of the application of the sine wave in music

Adaptation Actions in Africa: Evidence that Gender Matters

This paper presents the initial data analyses of the CCAFS gender survey implemented in four sites in Africa. Using descriptive statistics we show gender differences in terms of perceptions of climate change, awareness and adoption of climate smart agricultural (CSA) practices, and types and sources of agro-climatic information in the four sites.We find that both men and women are experiencing changes in long-run weather patterns and that they are changing their behaviours in response; albeit relatively minor shifts in existing agricultural practices. For example, the most prevalent changes reported include switching crop varieties, switching types of crops and changing planting dates. As expected, women are less aware of many CSA practices. Encouragingly, this same pattern does not hold when it comes to adoption; in many cases, in East Africa in particular, women, when aware, are more likely than or just as likely as men to adopt CSA practices. In West Africa, overall, the adoption of these practices was much lower. In addition, we see that access to information from different sources varies greatly between men and women and among the sites; however, promisingly, those with access to information report using it to make changes to their agricultural practices. Our findings suggest that targeting women with climate and agricultural information is likely to result in uptake of new agricultural practices for adaptation

APPleSOSS: A Producer of ProfiLEs for SOSS. Application to the NIRISS SOSS Mode

The SOSS mode of the NIRISS instrument is poised to be one of the workhorse modes for exoplanet atmosphere observations with the newly launched James Webb Space Telescope. One of the challenges of the SOSS mode, however, is the physical overlap of the first two diffraction orders of the G700XD grism on the detector. Recently, the ATOCA algorithm was developed and implemented as an option in the official JWST pipeline, as a method to extract SOSS spectra by decontaminating the detector -- that is, separating the first and second orders. Here, we present APPleSOSS (A Producer of ProfiLEs for SOSS), which generates the spatial profiles for each diffraction order upon which ATOCA relies. We validate APPleSOSS using simulated SOSS time series observations of WASP-52b, and compare it to ATOCA extractions using two other spatial profiles (a best and worst case scenario on-sky), as well as a simple box extraction performed without taking into account the order contamination. We demonstrate that APPleSOSS traces retain a high degree of fidelity to the true underlying spatial profiles, and therefore yield accurate extracted spectra. We further confirm that the effects of the order contamination for relative measurements (e.g., exoplanet transmission or emission observations) is small -- the transmission spectrum obtained from each of our four tests, including the contaminated box extraction, deviates by $\lesssim$0.1$\sigma$ from the atmosphere model input into our noiseless simulations. We further confirm via a retrieval analysis that the atmosphere parameters (metallicity and C/O) obtained from each transmission spectrum are consistent at the 1$\sigma$ level with the true underlying values.Comment: 12 pages, 9 figures. Submitted to PAS

ATOCA: an algorithm to treat order contamination. Application to the NIRISS SOSS mode

After a successful launch, the James Webb Space Telescope is preparing to undertake one of its principal missions, the characterization of the atmospheres of exoplanets. The Single Object Slitless Spectroscopy (SOSS) mode of the Near Infrared Imager and Slitless Spectrograph (NIRISS) is the only observing mode that has been specifically designed for this objective. It features a wide simultaneous spectral range (0.6--2.8\,\micron) through two spectral diffraction orders. However, due to mechanical constraints, these two orders overlap slightly over a short range, potentially introducing a ``contamination'' signal in the extracted spectrum. We show that for a typical box extraction, this contaminating signal amounts to 1\% or less over the 1.6--2.8\,\micron\ range (order 1), and up to 1\% over the 0.85--0.95\,\micron\ range (order 2). For observations of exoplanet atmospheres (transits, eclipses or phase curves) where only temporal variations in flux matter, the contamination signal typically biases the results by order of 1\% of the planetary atmosphere spectral features strength. To address this problem, we developed the Algorithm to Treat Order ContAmination (ATOCA). By constructing a linear model of each pixel on the detector, treating the underlying incident spectrum as a free variable, ATOCA is able to perform a simultaneous extraction of both orders. We show that, given appropriate estimates of the spatial trace profiles, the throughputs, the wavelength solutions, as well as the spectral resolution kernels for each order, it is possible to obtain an extracted spectrum accurate to within 10\,ppm over the full spectral range.Comment: Submitted to PASP. 22 pages, 12 figure

Atmospheric Reconnaissance of TRAPPIST-1 b with JWST/NIRISS: Evidence for Strong Stellar Contamination in the Transmission Spectra

TRAPPIST-1 is a nearby system of seven Earth-sized, temperate, rocky exoplanets transiting a Jupiter-sized M8.5V star, ideally suited for in-depth atmospheric studies. Each TRAPPIST-1 planet has been observed in transmission both from space and from the ground, confidently rejecting cloud-free, hydrogen-rich atmospheres. Secondary eclipse observations of TRAPPIST-1 b with JWST/MIRI are consistent with little to no atmosphere given the lack of heat redistribution. Here we present the first transmission spectra of TRAPPIST-1 b obtained with JWST/NIRISS over two visits. The two transmission spectra show moderate to strong evidence of contamination from unocculted stellar heterogeneities, which dominates the signal in both visits. The transmission spectrum of the first visit is consistent with unocculted starspots and the second visit exhibits signatures of unocculted faculae. Fitting the stellar contamination and planetary atmosphere either sequentially or simultaneously, we confirm the absence of cloud-free hydrogen-rich atmospheres, but cannot assess the presence of secondary atmospheres. We find that the uncertainties associated with the lack of stellar model fidelity are one order of magnitude above the observation precision of 89 ppm (combining the two visits). Without affecting the conclusion regarding the atmosphere of TRAPPIST-1 b, this highlights an important caveat for future explorations, which calls for additional observations to characterize stellar heterogeneities empirically and/or theoretical works to improve model fidelity for such cool stars. This need is all the more justified as stellar contamination can affect the search for atmospheres around the outer, cooler TRAPPIST-1 planets for which transmission spectroscopy is currently the most efficient technique.Comment: 26 pages, 11 figures, accepted for publication in The Astrophysical Journal Letter

Chronic disease patients' experience with telehealth interventions and self-care strategies during the first wave of the COVID-19 pandemic

Purpose. During the COVID-19 pandemic, the Québec Public Health Agency asked Family Medicine Groups (FMGs) to prioritize telehealth interventions over face-to-face consultations. Telehealth interventions may increase stress and anxiety among patients with physical and/or mental chronic diseases (PCDs) and have a negative impact on patient-centered care. This study aimed to explore how PCDs coped with their healthcare needs through the use of telehealth services provided by FMGs during the first wave of the COVID-19 pandemic, between march and august 2020. Methods. We conducted a qualitative descriptive study in FMGs in three regions of the province of Québec, Canada (metropolitan, semi-urban and rural). Forty-nine PCDs participated in this study. We carried out semi-structured interviews with 40 of these patients. We explored their satisfaction with telehealth services received in FMGs, their healthcare needs and emerging coping strategies related to self-care. We also investigated frequency of appointments in primary care. We used the transactional theory of stress and coping to inform our data collection and analysis, according to the COREQ appraisal grid. Results. All PCDs were satisfied with their telehealth experience. They reported quick and easy access to their family physician or other healthcare providers. Participants thought telehealth was less appropriate for follow-ups with social workers or with any healthcare provider with whom no trust relationship had been established. Furthermore, several PCDs mentioned having visited primary care settings less frequently during the pandemic than before, as most of them tried to cope on their own before making an appointment for an in-person consultation. PCDs developed coping strategies primarily aimed at maintaining their health status, others aimed at reducing their stress. Consistent with the transactional model, many participants demonstrated the use of strategies that promote resilience in a pandemic context. Conclusion. PCDs appreciated the telehealth interventions received but believe follow-ups could be improved. PCDs developed coping strategies to face the pandemic but they were not all optimal for their health. Combined with pandemic side effects, this could lead to a negative impact on PCDs’ health and self-management abilities

Major-Effect Alleles at Relatively Few Loci Underlie Distinct Vernalization and Flowering Variation in Arabidopsis Accessions

We have explored the genetic basis of variation in vernalization requirement and response in Arabidopsis accessions, selected on the basis of their phenotypic distinctiveness. Phenotyping of F2 populations in different environments, plus fine mapping, indicated possible causative genes. Our data support the identification of FRI and FLC as candidates for the major-effect QTL underlying variation in vernalization response, and identify a weak FLC allele, caused by a Mutator-like transposon, contributing to flowering time variation in two N. American accessions. They also reveal a number of additional QTL that contribute to flowering time variation after saturating vernalization. One of these was the result of expression variation at the FT locus. Overall, our data suggest that distinct phenotypic variation in the vernalization and flowering response of Arabidopsis accessions is accounted for by variation that has arisen independently at relatively few major-effect loci