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Amphibians are rapidly vanishing. At the same time, it is most likely that the number of amphibian species is highly underestimated. Recent DNA barcoding work has attempted to define a threshold between intra- and inter-specific genetic distances to help identify candidate species. In groups with high extinction rates and poorly known species boundaries, like amphibians, such tools may provide a way to rapidly evaluate species richness. Here we analyse published and new 16S rDNA sequences from 60 frog species of Amazonia-Guianas to obtain a minimum estimate of the number of undescribed species in this region. We combined isolation by distance, phylogenetic analyses, and comparison of molecular distances to evaluate threshold values for the identification of candidate species among these frogs. In most cases, geographically distant populations belong to genetically highly distinct lineages that could be considered as candidate new species. This was not universal among the taxa studied and thus widespread species of Neotropical frogs really do exist, contrary to previous assumptions. Moreover, the many instances of paraphyly and the wide overlap between distributions of inter- and intra-specific distances reinforce the hypothesis that many cryptic species remain to be described. In our data set, pairwise genetic distances below 0.02 are strongly correlated with geographical distances. This correlation remains statistically significant until genetic distance is 0.05, with no such relation thereafter. This suggests that for higher distances allopatric and sympatric cryptic species prevail. Based on our analyses, we propose a more inclusive pairwise genetic distance of 0.03 between taxa to target lineages that could correspond to candidate species. Using this approach, we identify 129 candidate species, two-fold greater than the 60 species included in the current study. This leads to estimates of around 170 to 460 frog taxa unrecognized in Amazonia-Guianas. As a consequence the global amphibian decline detected especially in the Neotropics may be worse than realised.

Mutations in GPSM2 cause Chudley-McCullough syndrome (CMCS), an autosomal recessive neurological disorder characterized by early-onset sensorineural deafness and brain anomalies. Here, we show that mutation of the mouse orthologue of GPSM2 affects actin-rich stereocilia elongation in auditory and vestibular hair cells, causing deafness and balance defects. The G-protein subunit Gα i3 , a well-documented partner of Gpsm2, participates in the elongation process, and its absence also causes hearing deficits. We show that Gpsm2 defines an ∼200 nm nanodomain at the tips of stereocilia and this localization requires the presence of Gα i3 , myosin 15 and whirlin. Using single-molecule tracking, we report that loss of Gpsm2 leads to decreased outgrowth and a disruption of actin dynamics in neuronal growth cones. Our results elucidate the aetiology of CMCS and highlight a new molecular role for Gpsm2/Gα i3 in the regulation of actin dynamics in epithelial and neuronal tissues. Mutations in GPSM2 cause a rare disease characterized by deafness and brain abnormalities. Here the authors show that Gpsm2 forms a molecular complex with a heterotrimeric G-protein subunit, whirlin and a myosin motor to regulate actin dynamics in neurons and auditory hair cell stereocilia.

Diffuse large B-cell lymphoma is a common cancer in elderly patients. Although treatment has been standardised in younger patients, no prospective study has been done in patients over 80 years old. We aimed to investigate the efficacy and safety of a decreased dose of CHOP (doxorubicin, cyclophosphamide, vincristine, and prednisone) chemotherapy with a conventional dose of rituximab in elderly patients with diffuse large B-cell lymphoma. We did a prospective, multicentre, single-arm, phase 2 study of patients aged over 80 years who had diffuse large B-cell lymphoma. Patients were included from 38 centres in France and Belgium. All patients received six cycles of rituximab combined with low-dose CHOP (R-miniCHOP) at 3-week intervals. Patients received 375 mg/m 2 rituximab, 400 mg/m 2 cyclophosphamide, 25 mg/m 2 doxorubicin, and 1 mg vincristine on day 1 of each cycle, and 40 mg/m 2 prednisone on days 1–5. The primary endpoint was overall survival, both unadjusted and adjusted for treatment and baseline prognostic factors. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, NCT01087424. 150 patients were enrolled between Jan 9, 2006, and Jan 23, 2009 and 149 were included in the intention-to-treat analyses. Median age was 83 years (range 80–95). After a median follow-up of 20 months (range 0–45), the median overall survival was 29 months (95% CI 21 to upper limit not reached); 2-year overall survival was 59% (49–67%). In multivariate analyses, overall survival was only affected by a serum albumin concentration of 35 g/L or less (hazard ratio 3·2, 95% CI 1·4–7·1; p=0·0053). Median progression-free survival was 21 months (95% CI 13 to upper limit not reached), with a 2-year progression free survival of 47% (38–56). 58 deaths were reported, 33 of which were secondary to lymphoma progression. 12 deaths were attributed to toxicity of the treatment. The most frequent side-effect was haematological toxicity (grade ≥3 neutropenia in 59 patients; febrile neutropenia in 11 patients). R-miniCHOP offers a good compromise between efficacy and safety in patients aged over 80 years old. R-miniCHOP should be considered as the new standard treatment in this subgroup of patients. Groupe d'Etude des Lymphomes de l'Adulte (GELA).

Among exoplanets, the small-size population constitutes the dominant one, with a diversity of properties and compositions ranging from rocky to gas dominated envelope. While a large fraction of them have masses and radii similar to or smaller than Neptune, yet none share common properties in term of orbital period and insulation with our ice giants. These exoplanets belong to multi-planet systems where planets are closely packed within the first tenth of AU and often exposed to strong irradiation from their host star. Their formation process, subsequent evolution, and fate are still debated and trigger new developments of planet formation models. This paper reviews the characteristics and properties of this extended sample of planets with radii between ∼1.6 and 4.0 R ⊕ . Even though we still lack real Neptune/Uranus analogues, these exoplanets provide us with key observational constraints that allow the formation of our ice giants to be placed in a more general framework than the sole example of our solar system.

Injection flux tubes, characterized by localized equatorial magnetic field enhancements and concomitant hot plasma populations, contribute to Saturn's magnetospheric convection cycle by transporting magnetic flux radially inward. The sharp magnetic gradients at the flux‐tube edges have been demonstrated to enable the trapping of equatorially mirroring particles, leading to their energy‐dispersionless signatures in spacecraft observations. Here, we present a statistical distinction between flux tubes with and without particle‐trapping features in the electron cyclotron harmonic (ECH) wave properties. The particle‐trapping flux tubes carry stronger ECH waves in the high‐harmonic bands, whereas the other category is usually accompanied only by fundamental‐mode waves. This distinction is largely attributed to the higher content of energetic electrons within the particle‐trapping flux tubes. These results improve our understanding of the association between injection flux tubes and the high‐band ECH waves therein, suggesting a unique role of particle‐trapping flux tubes in Saturnian magnetospheric dynamics. Plain Language Summary In Saturn's magnetosphere, the plasma convection involves the inward motion of localized injection flux tubes characterized by enhanced magnetic field strength and energetic particle fluxes. The flux enhancements of particles at different energies are usually asynchronous because of their energy‐dependent drift speeds around Saturn. In certain events, however, this picture could be modified by sharp magnetic gradients at flux‐tube edges, which lead to the trapping of near‐equatorial particles manifested by their simultaneous flux enhancements over a wide energy range. Here, we analyze the Cassini observations of injection flux tubes, categorize them into those with and without particle‐trapping features, and examine their associated electrostatic wave properties. The particle‐trapping flux tubes are statistically associated with waves at discrete frequencies between harmonics of the electron gyrofrequency, known as electron cyclotron harmonic waves. These emissions occur in both the fundamental‐mode and high‐harmonic bands. In contrast, non‐trapping flux tubes are predominantly accompanied by fundamental‐mode waves only. The different wave properties are attributed to the higher content of energetic electrons in particle‐trapping flux tubes. These findings highlight the role of injection flux tubes in Saturn's magnetospheric dynamics. Key Points Particle‐trapping flux tubes with energy‐dispersionless features of equatorially mirroring particles carry intense electron cyclotron harmonic (ECH) waves in high bands Particle‐trapping flux tubes correspond to stronger magnetic field enhancements and higher content of energetic electrons than other events Parametric analysis demonstrates the important role of energetic electrons above 1 keV in the excitation of ECH waves in high harmonic bands

In Saturn's magnetosphere, the radially‐inward transport of magnetic fluxes is usually carried by localized flux tubes with sharply‐enhanced equatorial magnetic fields. The flux tubes also bring energetic particles inward, which are expected to drift azimuthally and produce energy‐dispersive signatures. Spacecraft observations, however, indicate the occurrence of energy‐dispersionless signatures for perpendicular‐moving particles. These unexpected features are attributed to the sharp magnetic gradient at the edge of the flux tubes, which significantly modifies the drift trajectories of perpendicular‐moving particles to enable their trapping motion within the flux tubes. The bouncing particles are less affected by the gradient, and therefore, still display energy‐dispersive signatures. It is the distinct particle behavior, together with different spacecraft traversal paths, that underlies the observational diversity. The results improve our understanding of particle dynamics in the magnetospheres of giant planets and indicate that pitch‐angle information should be considered in the extraction of flux‐tube properties from energetic particle observations. Plain Language Summary The conservation of magnetic fluxes in Saturn's magnetosphere requires that the outward convection is compensated by a return process of magnetic fluxes, which has been observed in the form of localized flux tubes associated with sharply‐enhanced equatorial magnetic field and hot plasma population. The azimuthal drift of energetic particles within the flux tubes produces energy‐dispersive signatures, which have been utilized to estimate the age and starting position of the returning flux tubes. In this paper, we are motivated by Cassini observations of energy‐dispersionless signatures for perpendicular‐moving particles, to demonstrate that their drift paths can be significantly modified by the sharp magnetic gradient to cause their trapping within the flux tubes. The bouncing particles, on the other hand, are less affected by the gradient and, therefore, can leave the flux tubes to continue their drift around the planet. We further construct the magnetic configuration associated with the flux tubes, to illustrate the origin of the diverse observational signatures depending on particle pitch angle, spacecraft traversal path, and the trapping extent. These results have important implications for the interpretation of observational data in the injection flux tubes, and therefore improve our understanding of giant planet's magnetosphere and the associated particle dynamics. Key Points In Saturn's injection flux tubes, charged particles often show distinct energy‐dispersive or dispersionless signals depending on pitch angle The unexpected, energy‐dispersionless features for perpendicular‐moving particles are formed by their trapping motion within the flux tubes The bouncing particles can hardly be trapped, and therefore, exhibit the characteristic energy dispersion and particle leaking signatures

This paper is an introduction to volume 56 of the Space Science Series of ISSI, “From disks to planets—the making of planets and their proto-atmospheres”, a key subject in our quest for the origins and evolutionary paths of planets, and for the causes of their diversity. Indeed, as exoplanet discoveries progressively accumulated and their characterization made spectacular progress, it became evident that the diversity of observed exoplanets can in no way be reduced to the two classes of planets that we are used to identify in the solar system, namely terrestrial planets and gas or ice giants: the exoplanet reality is just much broader. This fact is no doubt the result of the exceptional diversity of the evolutionary paths linking planetary systems as a whole as well as individual exoplanets and their proto-atmospheres to their parent circumstellar disks: this diversity and its causes are exactly what this paper explores. For each of the main phases of the formation and evolution of planetary systems and of individual planets, we summarize what we believe we understand and what are the important open questions needing further in-depth examination, and offer some suggestions on ways towards solutions. We start with the formation mechanisms of circumstellar disks, with their gas and disk components in which chemical composition plays a very important role in planet formation. We summarize how dust accretion within the disk generates planet cores, while gas accretion on these cores can lead to the diversity of their fluid envelopes. The temporal evolution of the parent disk itself, and its final dissipation, put strong constraints on how and how far planetary formation can proceed. The radiation output of the central star also plays an important role in this whole story. This early phase of planet evolution, from disk formation to dissipation, is characterized by a co-evolution of the disk and its daughter planets. During this co-evolution, planets and their protoatmospheres not only grow, but they also migrate radially as a result of their interaction with the disk, thus moving progressively from their distance of formation to their final location. The formation of planetary fluid envelopes (proto-atmospheres and oceans), is an essential product of this planet formation scenario which strongly constrains their possible evolution towards habitability. We discuss the effects of the initial conditions in the disk, of the location, size and mass of the planetary core, of the disk lifetime and of the radiation output and activity of the central star, on the formation of these envelopes and on their relative extensions with respect to the planet core. Overall, a fraction of the planets retain the primary proto-atmosphere they initially accreted from the gas disk. For those which lose it in this early evolution, outgassing of volatiles from the planetary core and mantle, together with some contributions of volatiles from colliding bodies, give them a chance to form a “secondary” atmosphere, like that of our own Earth. When the disk finally dissipates, usually before 10 Million years of age, it leaves us with the combination of a planetary system and a debris disk, each with a specific radial distribution with respect to their parent star(s). Whereas the dynamics of protoplanetary disks is dominated by gas-solid dynamical coupling, debris disks are dominated by gravitational dynamics acting on diverse families of planetesimals. Solid-body collisions between them and giant impacts on young planetary surfaces generate a new population of gas and dust in those disks. Synergies between solar system and exoplanet studies are particularly fruitful and need to be stimulated even more, because they give access to different and complementary components of debris disks: whereas the different families of planetesimals can be extensively studied in the solar system, they remain unobserved in exoplanet systems. But, in those systems, long-wavelength telescopic observations of dust provide a wealth of indirect information about the unobserved population of planetesimals. Promising progress is being currently made to observe the gas component as well, using millimetre and sub-millimetre giant radio interferometers. Within planetary systems themselves, individual planets are the assembly of a solid body and a fluid envelope, including their planetary atmosphere when there is one. Their characteristics range from terrestrial planets through sub-Neptunes and Neptunes and to gas giants, each type covering most of the orbital distances probed by present-day techniques. With the continuous progress in detection and characterization techniques and the advent of major providers of new data like the Kepler mission, the architecture of these planetary systems can be studied more and more accurately in a statistically meaningful sense and compared to the one of our own solar system, which does not appear to be an exceptional case. Finally, our understanding of exoplanets atmospheres has made spectacular advances recently using the occultation spectroscopy techniques implemented on the currently operating space and ground-based observing facilities. The powerful new observing facilities planned for the near and more distant future will make it possible to address many of the most challenging current questions of the science of exoplanets and their systems. There is little doubt that, using this new generation of facilities, we will be able to reconstruct more and more accurately the complex evolutionary paths which link stellar genesis to the possible emergence of habitable worlds.

This updated and revised edition of Hamers and Blanc's successful textbook presents state-of-the-art knowledge about languages in contact from individual bilingualism (or bilinguality) to societal bilingualism. It is both multi- and interdisciplinary in approach, and analyses bilingualism at individual, interpersonal, and societal levels. Linguistic, cognitive and sociocultural aspects of bilingual development are explored, as are problems such as bilingual memory and polyglot aphasia. Hamers and Blanc analyse the relationship between culture, identity, and language behaviour in multicultural settings, as well as the communication strategies in interpersonal and intergroup relations. They also propose theoretical models of language processing and development, which are then applied to bilingual behaviour. Other topics reviewed include language shift, pidgins and creoles, language planning and bilingual education. This book will be invaluable to students, teachers and scholars interested in languages in contact in a range of disciplines including psycholinguistics, linguistics, the social sciences, education and language planning.

Nature Communications 8: Article number: 14907 (2017); Published: 7 April 2017; Updated: 25 May 2018 The original version of this Article contained an error in the spelling of the author Aysegul Gezer, which was incorrectly given as Aysegul Geyser. This has now been corrected in both the PDF and HTML versions of the Article.