The Spin-Orbit Evolution of GJ 667C System: The Effect of Composition and Other Planet's Perturbations

Potentially habitable planets within the habitable zone of M-dwarfs are affected by tidal interaction. We studied the tidal evolution in GJ 667C using a numerical code we call TIDEV. We reviewed the problem of the dynamical evolution focusing on the effects that a rheological treatment, different compositions and the inclusion of orbital perturbations, have on the spin-down time and the probability to be trapped in a low spin-orbit resonance. Composition have a strong effect on the spin-down time, changing, in some cases, by almost a factor of 2 with respect to the value estimated for a reference Earth-like model. We calculated the time to reach a low resonance value (3:2) for the configuration of 6 planets. Capture probabilities are affected when assuming different compositions and eccentricities variations. We chose planets b and c to evaluate the probabilities of capture in resonances below 5:2 for two compositions: Earth-like and Waterworld planets. We found that perturbations, although having a secular effect on eccentricities, have a low impact on capture probabilities and noth- ing on spin-down times. The implications of the eccentricity variations and actual habitability of the GJ 667C system are discussed.Comment: 15 pages, 9 figures, 4 tables. Accepted for publication in MNRAS - V

Tidal decay and orbital circularization in close-in two-planet systems

The motion of two planets around a Sun-like star under the combined effects of mutual interaction and tidal dissipation is investigated. The secular behaviour of the system is analyzed using two different approaches. First, we solve the exact equations of motion through the numerical simulation of the system evolution. In addition to the orbital decay and circularization, we show that the final configuration of the system is affected by the shrink of the inner orbit. Our second approach consist in the analysis of the stationary solutions of mean equations of motion based on a Hamiltonian formalism. We consider the case of a hot super-Earth planet with a more massive outer companion. As a real example, the CoRoT-7 system is analyzed solving the exact and mean equations of motion. The star-planet tidal interaction produces orbital decay and circularization of the orbit of CoRoT-7b. In addition, the long-term tidal evolution is such that the eccentricity of CoRoT-7c is also circularized and a pair of final circular orbits is obtained. A curve in the space of eccentricities can be constructed through the computation of stationary solutions of mean equations including dissipation. The application to CoRoT-7 system shows that the stationary curve agrees with the result of numerical simulations of exact equations. A similar investigation performed in a super-Earth-Jupiter two-planet system shows that the doubly circular state is accelerated when there is a significant orbital migration of the inner planet, in comparison with previous results were migration is neglected.Comment: Accepted for publication in MNRAS; 10 pages, 13 figure

NaV1.1 is essential for proprioceptive signaling and motor behaviors

The voltage-gated sodium channel (NaV), NaV1.1, is well-studied in the central nervous system; conversely, its contribution to peripheral sensory neuron function is more enigmatic. Here, we identify a new role for NaV1.1 in mammalian proprioception. RNAscope analysis and in vitro patch-clamp recordings in genetically identified mouse proprioceptors show ubiquitous channel expression and significant contributions to intrinsic excitability. Notably, genetic deletion of NaV1.1 in sensory neurons caused profound and visible motor coordination deficits in conditional knockout mice of both sexes, similar to conditional Piezo2-knockout animals, suggesting that this channel is a major contributor to sensory proprioceptive transmission. Ex vivo muscle afferent recordings from conditional knockout mice found that loss of NaV1.1 leads to inconsistent and unreliable proprioceptor firing characterized by action potential failures during static muscle stretch; conversely, afferent responses to dynamic vibrations were unaffected. This suggests that while a combination of Piezo2 and other NaV isoforms is sufficient to elicit activity in response to transient stimuli, NaV1.1 is required for transmission of receptor potentials generated during sustained muscle stretch. Impressively, recordings from afferents of heterozygous conditional knockout animals were similarly impaired, and heterozygous conditional knockout mice also exhibited motor behavioral deficits. Thus, NaV1.1 haploinsufficiency in sensory neurons impairs both proprioceptor function and motor behaviors. Importantly, human patients harboring NaV1.1 loss-of-function mutations often present with motor delays and ataxia; therefore, our data suggest that sensory neuron dysfunction contributes to the clinical manifestations of neurological disorders in which NaV1.1 function is compromised. Collectively, we present the first evidence that NaV1.1 is essential for mammalian proprioceptive signaling and behaviors

Stability of Terrestrial Planets in the Habitable Zone of Gl 777 A, HD 72659, Gl 614, 47 Uma and HD 4208

We have undertaken a thorough dynamical investigation of five extrasolar planetary systems using extensive numerical experiments. The systems Gl 777 A, HD 72659, Gl 614, 47 Uma and HD 4208 were examined concerning the question of whether they could host terrestrial like planets in their habitable zones (=HZ). First we investigated the mean motion resonances between fictitious terrestrial planets and the existing gas giants in these five extrasolar systems. Then a fine grid of initial conditions for a potential terrestrial planet within the HZ was chosen for each system, from which the stability of orbits was then assessed by direct integrations over a time interval of 1 million years. The computations were carried out using a Lie-series integration method with an adaptive step size control. This integration method achieves machine precision accuracy in a highly efficient and robust way, requiring no special adjustments when the orbits have large eccentricities. The stability of orbits was examined with a determination of the Renyi entropy, estimated from recurrence plots, and with a more straight forward method based on the maximum eccentricity achieved by the planet over the 1 million year integration. Additionally, the eccentricity is an indication of the habitability of a terrestrial planet in the HZ; any value of e>0.2 produces a significant temperature difference on a planet's surface between apoapse and periapse. The results for possible stable orbits for terrestrial planets in habitable zones for the five systems are summarized as follows: for Gl 777 A nearly the entire HZ is stable, for 47 Uma, HD 72659 and HD 4208 terrestrial planets can survive for a sufficiently long time, while for Gl 614 our results exclude terrestrial planets moving in stable orbits within the HZ.Comment: 14 pages, 18 figures submitted to A&

Approaches and geographical locations of respectful maternity care research: A scoping review

Background Peripartum mistreatment of women contributes to maternal mortality across the globe and disproportionately affects vulnerable populations. While traditionally recognized in low/low-middle-income countries, the extent of research on respectful maternity care and the types of mistreatment occurring in high-income countries is not well understood. We conducted a scoping review to 1) map existing respectful maternity care research by location, country income level, and approach, 2) determine if high-income countries have been studied equally when compared to low/low-middle-income countries, and 3) analyze the types of disrespectful care found in high-income countries. Methods A systematic search for published literature up to April 2021 using PubMed/MEDLINE, EMBASE, CINAHL Complete, and the Maternity & Infant Care Database was performed. Studies were included if they were full-length journal articles, published in any language, reporting original data on disrespectful maternal care received from healthcare providers during childbirth. Study location, country income level, types of mistreatment reported, and treatment interventions were extracted. This study was registered on PROSPERO, number CRD42021255337. Results A total of 346 included studies were categorized by research approach, including direct labor observation, surveys, interviews, and focus groups. Interviews and surveys were the most common research approaches utilized (47% and 29% of all articles, respectively). Only 61 (17.6%) of these studies were conducted in high-income countries. The most common forms of mistreatment reported in high-income countries were lack of informed consent, emotional mistreatment, and stigma/discrimination. Conclusions Mapping existing research on respectful maternity care by location and country income level reveals limited research in high-income countries and identifies a need for a more global approach. Furthermore, studies of respectful maternity care in high-income countries identify the occurrence of all forms of mistreatment, clashing with biases that suggest respectful maternity care is only an issue in low-income countries and calling for additional research to identify interventions that embrace an equitable, patient-centric empowerment model of maternity care

Cretaceous Continental Bridges, Insularity, and Vicariance in the Southern Hemisphere: Which Route Did Dinosaurs Take?

The history of biota distribution in the southern hemisphere represents a fascinating and strongly debated argument. The sequential break-up of Gondwana was indeed responsible for physical barriers that precluded dispersal event, and therefore phylogenies? Did different organism had the opportunity for dispersal episodes through recently claimed continental bridges? When geographic and environmental conditions were suitable for active diffusion during the Mesozoic? Among the most relevant taxa that inhabitant the southern landmasses in the Cretaceous period are dinosaurs. Their vast stratigraphic and geographic occurrence is intimately linked to the evolution of Gondwana and recent discoveries from all southern landmasses greatly challenged several vicariant models. In this study are summarised the most significant geological, palaeogeographic, palaeontological and phylogenetic data on Cretaceous Gondwanan dinosaur evolution, with particular emphasis on the ephemeral land bridges that constitute the bulk of the recently developed biogeographic models. A comparison between different datasets suggest that a complex and sequential mix of vicariance and dispersal patterns characterized the distribution of dinosaurian faunas in the Cretaceous. In particular, this study dispute the role of ephemeral intercontinental connections for biota dispersal in the Late Cretaceous and support an earlier peak in dinosaur distribution