The realization and application of parallel linear feedback shift registers

Two methods for serial-to-parallel transformation of linear feedback shift registers are briefly discussed. A third method for transformation is rigorously developed using a next-state and output equation representation of the linear feedback shift register. An algorithm is developed for simplifying the parallel machine resulting from serial-to-parallel transformation, where simplification is defined as reduction in the required number of modulo 2 adders. A computer program incorporating serial-to-parallel transformation and the simplification algorithm is provided --Abstract, page ii

DI Diesel Engine Combustion Visualized by Combined Laser Techniques

In this work we demonstrate that the progress of the combustionccycle in a four-cylinder (in-line) 1.9 1 direct injection Diesel engine can be studied effectively using different laser visualization techniques. Direct optical access to the piston bowl was facilitated by inserting quartz windows in one of the pistons. The flow field at the time of injection was characterized by seeding the flow and illuminating the piston bowl with a laser light sheet. Fuel spray development, auto-ignition and flame propagation in a Diesel cycle were followed by laser shadowgraphy and high speed cinematography while simultaneous laser induced fluorescence (LIF) and Mie scattering images were taken to distinguish the fuel distribution in the liquid and vapor phase. In addition, two dimensional distributions of OH and NO, formed during n-heptane/air combustion in the same engine, were recorded in the pressure range 5 to 50 bar by LIF following narrowband excitation using tunable excimer lasers. Finally, further work, designed to obtain quantitative images and hence data for comparison with model calculations, is outlined.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86790/1/Sick50.pd

CHEOPS in-flight performance: A comprehensive look at the first 3.5 yr of operations

Context. Since the discovery of the first exoplanet almost three decades ago, the number of known exoplanets has increased dramatically. By beginning of the 2000s it was clear that dedicated facilities to advance our studies in this field were needed. The CHaracterising ExOPlanet Satellite (CHEOPS) is a space telescope specifically designed to monitor transiting exoplanets orbiting bright stars. In September 2023, CHEOPS completed its nominal mission duration of 3.5 yr and remains in excellent operational conditions. As a testament to this, the mission has been extended until the end of 2026. Aims. Scientific and instrumental data have been collected throughout in-orbit commissioning and nominal operations, enabling a comprehensive analysis of the mission’s performance. In this article, we present the results of this analysis with a twofold goal. First, we aim to inform the scientific community about the present status of the mission and what can be expected as the instrument ages. Secondly, we intend for this publication to serve as a legacy document for future missions, providing insights and lessons learned from the successful operation of CHEOPS. Methods. To evaluate the instrument performance in flight, we developed a comprehensive monitoring and characterisation (M&C) programme. It consists of dedicated observations that allow us to characterise the instrument’s response and continuously monitor its behaviour. In addition to the standard collection of nominal science and housekeeping data, these observations provide valuable input for detecting, modelling, and correcting instrument systematics, discovering and addressing anomalies, and comparing the instrument’s actual performance with expectations. Results. The precision of the CHEOPS measurements has enabled the mission objectives to be met and exceeded. The satellite’s performance remains stable and reliable, ensuring accurate data collection throughout its operational life. Careful modelling of the instrumental systematics allows the data quality to be significantly improved during the light curve analysis phase, resulting in more precise scientific measurements. Conclusions. CHEOPS is compliant with the driving scientific requirements of the mission. Although visible, the ageing of the instrument has not affected the mission’s performance. The satellite’s capabilities remain robust, and we are confident that we will continue to acquire high-quality data during the mission extension.Fil: Fortier, Andrés. University of Bern; Suiza. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Simon, A. E.. University of Bern; SuizaFil: Broeg, C.. University of Bern; SuizaFil: Olofsson, G.. Stockholms Universitet. Departamento de Astronomia; SueciaFil: Deline, A.. Universidad de Ginebra; SuizaFil: Wilson, T. G.. University of Warwick; Reino UnidoFil: Maxted, P. F. L.. Keele University.; Reino UnidoFil: Brandeker, A.. Stockholms Universitet. Departamento de Astronomia; SueciaFil: Collier Cameron, A.. University of St. Andrews; Reino UnidoFil: Beck, M.. Universidad de Ginebra; SuizaFil: Bekkelien, A.. Universidad de Ginebra; SuizaFil: Billot, N.. Universidad de Ginebra; SuizaFil: Bonfanti, A.. Austrian Academy Of Sciences (oaw);Fil: Bruno, G.. Inaf-catania Astrophysical Observatory; ItaliaFil: Cabrera, J.. German Aerospace Center.; AlemaniaFil: Delrez, L.. Université de Liège; BélgicaFil: Demory, Brice Olivier. University of Bern; SuizaFil: Futyan, D.. Universidad de Ginebra; SuizaFil: Florén, H. G.. Stockholms Universitet. Departamento de Astronomia; SueciaFil: Günther, M. N.. Agencia Espacial Europea; EspañaFil: Heitzmann, A.. Universidad de Ginebra; SuizaFil: Hoyer, S.. Centre National de la Recherche Scientifique; FranciaFil: Isaak, K. G.. Agencia Espacial Europea; EspañaFil: Sousa, S. G.. Aix Marseille Université; Francia. Centre National de la Recherche Scientifique; FranciaFil: Stalport, M.. Research Centre For Astronomy And Earth Sciences; Hungría. Université de Liège; BélgicaFil: Petrucci, Romina Paola. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Villaver, E.. Universidad de La Laguna; España. Instituto de Astrofísica de Canarias; EspañaFil: Vinkó, J.. Research Centre for Astronomy and Earth Sciences; Hungría. ELTE Eötvös Loránd University; Hungría. University of Szeged; HungríaFil: Walton, N. A.. University of Cambridge; Estados UnidosFil: Wells, R.. University of Bern; SuizaFil: Wolter, D.. Institute of Planetary Research; Alemani

TOI-3362b: A Proto Hot Jupiter Undergoing High-Eccentricity Tidal Migration

High-eccentricity tidal migration is a possible way for giant planets to be placed in short-period orbits. If this happens often, one would expect to catch proto hot Jupiters on highly elliptical orbits undergoing high-eccentricity tidal migration. As of yet, few such systems have been discovered. Here, we introduce TOI-3362b (TIC-464300749b), an 18.1 day, 5 MJup planet orbiting a main-sequence F-type star that is likely undergoing high-eccentricity tidal migration. The orbital eccentricity is 0.815 (+0.023)/(-0.032). With a semimajor axis of 0.153 (+0.002)/(-0.003) au, the planet\u27s orbit is expected to shrink to a final orbital radius of 0.051 (+0.008)/(-0.006) au after complete tidal circularization. Several mechanisms could explain the extreme value of the planet\u27s eccentricity, such as planet–planet scattering and secular interactions. Such hypotheses can be tested with follow-up observations of the system, e.g., measuring the stellar obliquity and searching for companions in the system with precise, long-term radial-velocity observations. The variation in the planet\u27s equilibrium temperature as it orbits the host star and the tidal heating at periapse make this planet an intriguing target for atmospheric modeling and observation. Because the planet\u27s orbital period of 18.1 days is near the limit of TESS\u27s period sensitivity, even a few such discoveries suggest that proto hot Jupiters may be quite common

A framework to assess welfare mix and service provision models in health care and social welfare: case studies of two prominent Italian regions

BACKGROUND: The mechanisms through which the relationships among public institutions, private providers and families affect care and service provision systems are puzzling. How can we understand the mechanisms in these contexts? Which elements should we explore to capture the complexity of care provision? The aim of our study is to provide a framework that can help read and reframe these puzzling care provision mechanisms in a welfare mix context. METHODS: First, we develop a theoretical framework for understanding how service provision occurs in care systems that are characterised by a variety of relationships between multiple actors, using an evidence-based approach that looks at both public and private expenditures and the number of users relative to the level of needs coverage and compared with declared values and political rhetoric. Second, we test this framework in two case studies built on data from two prominent Italian regions, Lombardy and Emilia-Romagna. We argue that service provision models depend on the interplay among six conceptual elements: policy values, governance rules, resources, nature of the providers, service standards and eligibility criteria. RESULTS: Our empirical study shows that beneath the relevant differences in values and political rhetoric between the case studies of the two Italian regions, there is a surprising isomorphism in service standards and the levels of covering the population’s needs. CONCLUSION: The suggested framework appears to be effective and feasible; it fosters interdisciplinary approaches and supports policy-making discussions. This study may contribute to deepening knowledge about public care service provision and institutional arrangements, which can be used to promote more effective reforms and may advance future research. Although the framework was tested on the Italian welfare system, it can be used to assess many different systems

The K+ Channel Opener 1-EBIO Potentiates Residual Function of Mutant CFTR in Rectal Biopsies from Cystic Fibrosis Patients

BACKGROUND: The identification of strategies to improve mutant CFTR function remains a key priority in the development of new treatments for cystic fibrosis (CF). Previous studies demonstrated that the K⁺ channel opener 1-ethyl-2-benzimidazolone (1-EBIO) potentiates CFTR-mediated Cl⁻ secretion in cultured cells and mouse colon. However, the effects of 1-EBIO on wild-type and mutant CFTR function in native human colonic tissues remain unknown. METHODS: We studied the effects of 1-EBIO on CFTR-mediated Cl⁻ secretion in rectal biopsies from 47 CF patients carrying a wide spectrum of CFTR mutations and 57 age-matched controls. Rectal tissues were mounted in perfused micro-Ussing chambers and the effects of 1-EBIO were compared in control tissues, CF tissues expressing residual CFTR function and CF tissues with no detectable Cl⁻ secretion. RESULTS: Studies in control tissues demonstrate that 1-EBIO activated CFTR-mediated Cl⁻ secretion in the absence of cAMP-mediated stimulation and potentiated cAMP-induced Cl⁻ secretion by 39.2±6.7% (P<0.001) via activation of basolateral Ca²⁺-activated and clotrimazole-sensitive KCNN4 K⁺ channels. In CF specimens, 1-EBIO potentiated cAMP-induced Cl⁻ secretion in tissues with residual CFTR function by 44.4±11.5% (P<0.001), but had no effect on tissues lacking CFTR-mediated Cl⁻ conductance. CONCLUSIONS: We conclude that 1-EBIO potentiates Cl⁻secretion in native CF tissues expressing CFTR mutants with residual Cl⁻ channel function by activation of basolateral KCNN4 K⁺ channels that increase the driving force for luminal Cl⁻ exit. This mechanism may augment effects of CFTR correctors and potentiators that increase the number and/or activity of mutant CFTR channels at the cell surface and suggests KCNN4 as a therapeutic target for CF

Three Saturn-mass planets transiting F-type stars revealed with TESS and HARPS: TOI-615b, TOI-622b, and TOI-2641b

While the sample of confirmed exoplanets continues to grow, the population of transiting exoplanets around early-type stars is still limited. These planets allow us to investigate the planet properties and formation pathways over a wide range of stellar masses and study the impact of high irradiation on hot Jupiters orbiting such stars. We report the discovery of TOI-615b, TOI-622b, and TOI-2641b, three Saturn-mass planets transiting main sequence, F-type stars. The planets were identified by the Transiting Exoplanet Survey Satellite (TESS) and confirmed with complementary ground-based and radial velocity observations. TOI-615b is a highly irradiated (∼1277 F) and bloated Saturn-mass planet (1.69-0.06+0.05 RJup and 0.43-0.08+0.09 MJup) in a 4.66 day orbit transiting a 6850 K star. TOI-622b has a radius of 0.82-0.03+0.03 RJup and a mass of 0.30-0.08+0.07 MJup in a 6.40 day orbit. Despite its high insolation flux (∼600 F), TOI-622b does not show any evidence of radius inflation. TOI-2641b is a 0.39-0.04+0.02 MJup planet in a 4.88 day orbit with a grazing transit (b = 1.04-0.06+0.05) that results in a poorly constrained radius of 1.61-0.64+0.46 RJup. Additionally, TOI-615b is considered attractive for atmospheric studies via transmission spectroscopy with ground-based spectrographs and JWST. Future atmospheric and spin-orbit alignment observations are essential since they can provide information on the atmospheric composition, formation, and migration of exoplanets across various stellar types

Characterising TOI-732 b and c: New insights into the M-dwarf radius and density valley

TOI-732 is an M dwarf hosting two transiting planets that are located on the two opposite sides of the radius valley. By doubling the number of available space-based observations and increasing the number of radial velocity (RV) measurements, we aim at refining the parameters of TOI-732 b and c. We also use the results to study the slope of the radius valley and the density valley for a well-characterised sample of M-dwarf exoplanets. We performed a global MCMC analysis by jointly modelling ground-based light curves and CHEOPS and TESS observations, along with RV time series both taken from the literature and obtained with the MAROON-X spectrograph. The slopes of the M-dwarf valleys were quantified via a Support Vector Machine (SVM) procedure. TOI-732 b is an ultrashort-period planet ($P\sim0.77$ d) with a radius $R_b=1.325_{-0.058}^{+0.057}$ $R_{\oplus}$ and a mass $M_b=2.46\pm0.19$ $M_{\oplus}$ (mean density $\rho_b=5.8_{-0.8}^{+1.0}$ g cm$^{-3}$), while the outer planet at $P\sim12.25$ d has $R_c=2.39_{-0.11}^{+0.10}$ $R_{\oplus}$, $M_c=8.04_{-0.48}^{+0.50}$ $M_{\oplus}$, and thus $\rho_c=3.24_{-0.43}^{+0.55}$ g cm$^{-3}$. Also taking into account our interior structure calculations, TOI-732 b is a super-Earth and TOI-732 c is a mini-Neptune. Following the SVM approach, we quantified $\mathrm{d}\log{R_{p,{\mathrm{valley}}}}/\mathrm{d}\log{P}=-0.065_{-0.013}^{+0.024}$, which is flatter than for Sun-like stars. In line with former analyses, we note that the radius valley for M-dwarf planets is more densely populated, and we further quantify the slope of the density valley as $\mathrm{d}\log{\hat{\rho}_{\mathrm{valley}}}/\mathrm{d}\log{P}=-0.02_{-0.04}^{+0.12}$. Compared to FGK stars, the weaker dependence of the position of the radius valley on the orbital period might indicate that the formation shapes the radius valley around M dwarfs more strongly than the evolution mechanisms.Comment: 28 pages (17 in the main text), 18 figures (9 in the main text), 11 tables (7 in the main text). Accepted for publication in A&

ATREIDES:I. Embarking on a trek across the exo-Neptunian landscape with the TOI-421 system

Thedistribution of close-in exoplanets is shaped by a complex interplay betweenatmospheric and dynamical processes. The Desert, Ridge, and Savanna(respectively a lack, overoccurence, and mild deficit of Neptunes withincreasing periods) illustrate the sensitivity of these worlds to suchprocesses, making them ideal targets to disentangle their roles. Determininghow many Neptunes are brought close-in by early disk-driven migration (DDM;expected to maintain primordial spin-orbit alignment) or late high-eccentricitytidal migration (HEM; expected to generate large misalignments) is essential tounderstanding how much atmosphere they lost. In this paper, we propose aunified view of the exo-Neptunian landscape to guide its exploration andspeculate that the Ridge is a hot spot for evolutionary processes. Low-densityNeptunes would mainly undergo DDM, becoming fully eroded at shorter periodsthan the Ridge. This is in contrast to denser Neptunes, which would be broughtto the Ridge and Desert by HEM. We embark on this exploration via the ATREIDES(Ancestry, Traits, and Relations of Exoplanets Inhabiting the Desert Edges andSavanna) collaboration, which relies on spectroscopic and photometricobservations of ~60 close-in Neptunes, their reduction with robust pipelines,and their interpretation through internal structure, atmospheric, andevolutionary models. We carried out a systematic Rossiter-McLaughlin censuswith VLT/ESPRESSO to measure the distribution of 3D spin-orbit angles,correlate its shape with the system properties (orbit, density, evaporation),and thus relate the fraction of aligned-misaligned Neptunian systems to DDM,HEM, and atmospheric erosion. The first ATREIDES target, TOI-421 c, lies in theSavanna with a neighboring sub-Neptune TOI-421 b. We measured for the firsttime their 3D spin-orbit angles (ψb = 57−15+11∘; ψc = 44.9−4.1+4.4∘). Together with the eccentricity and possibly large mutualinclination of their orbits, this hints at a chaotic dynamical origin thatcould result from DDM followed by HEM. Our program will provide the communitywith a wealth of constraints for formation and evolution models, and we welcomecollaborations that will contribute to pushing our understanding of theexo-Neptunian landscape forward.</p

Detailed cool star flare morphology with CHEOPS and TESS

Context. White-light stellar flares are proxies for some of the most energetic types of flares, but their triggering mechanism is still poorly understood. As they are associated with strong X and UV emission, their study is particularly relevant to estimate the amount of high-energy irradiation onto the atmospheres of exoplanets, especially those in their stars' habitable zone. Aims. We used the high-cadence, high-photometric capabilities of the CHEOPS and TESS space telescopes to study the detailed morphology of white-light flares occurring in a sample of 130 late-K and M stars, and compared our findings with results obtained at a lower cadence. We developed dedicated software for this purpose. Results. Multi-peak flares represent a significant percentage ($\gtrsim 30$\%) of the detected outburst events. Our findings suggest that high-impulse flares are more frequent than suspected from lower-cadence data, so that the most impactful flux levels that hit close-in exoplanets might be more time-limited than expected. We found significant differences in the duration distributions of single-peak and complex flare components, but not in their peak luminosity. A statistical analysis of the flare parameter distributions provides marginal support for their description with a log-normal instead of a power-law function, leaving the door open to several flare formation scenarios. We tentatively confirmed previous results about quasi-periodic pulsations in high-cadence photometry, report the possible detection of a pre-flare dip, and did not find hints of photometric variability due to an undetected flare background. Conclusions. The high-cadence study of stellar hosts might be crucial to evaluate the impact of their flares on close-in exoplanets, as their impulsive phase emission might otherwise be incorrectly estimated. Future telescopes such as PLATO and Ariel will help in this respect.Comment: 28 pages, 25 figures, 4 tables, to be published in Astronomy & Astrophysic