ABSTRACT
Spectroscopy of transiting exoplanets can be used to investigate their atmospheric properties and habitability. Combining radial velocity (RV) and transit data provides additional information on exoplanet physical properties. We detect a transiting rocky planet with an orbital period of 1.467 days around the nearby red dwarf star Gliese 486. The planet Gliese 486 b is 2.81 Earth masses and 1.31 Earth radii, with uncertainties of 5%, as determined from RV data and photometric light curves. The host star is at a distance of ~8.1 parsecs, has a J-band magnitude of ~7.2, and is observable from both hemispheres of Earth. On the basis of these properties and the planet's short orbital period and high equilibrium temperature, we show that this terrestrial planet is suitable for emission and transit spectroscopy.
ABSTRACT
The closet exoplanets to the Sun provide opportunities for detailed characterization of planets outside the Solar System. We report the discovery, using radial velocity measurements, of a compact multiplanet system of super-Earth exoplanets orbiting the nearby red dwarf star GJ 887. The two planets have orbital periods of 9.3 and 21.8 days. Assuming an Earth-like albedo, the equilibrium temperature of the 21.8-day planet is ~350 kelvin. The planets are interior to, but close to the inner edge of, the liquid-water habitable zone. We also detect an unconfirmed signal with a period of ~50 days, which could correspond to a third super-Earth in a more temperate orbit. Our observations show that GJ 887 has photometric variability below 500 parts per million, which is unusually quiet for a red dwarf.
ABSTRACT
Surveys have shown that super-Earth and Neptune-mass exoplanets are more frequent than gas giants around low-mass stars, as predicted by the core accretion theory of planet formation. We report the discovery of a giant planet around the very-low-mass star GJ 3512, as determined by optical and near-infrared radial-velocity observations. The planet has a minimum mass of 0.46 Jupiter masses, very high for such a small host star, and an eccentric 204-day orbit. Dynamical models show that the high eccentricity is most likely due to planet-planet interactions. We use simulations to demonstrate that the GJ 3512 planetary system challenges generally accepted formation theories, and that it puts constraints on the planet accretion and migration rates. Disk instabilities may be more efficient in forming planets than previously thought.
ABSTRACT
Barnard's star is a red dwarf, and has the largest proper motion (apparent motion across the sky) of all known stars. At a distance of 1.8 parsecs1, it is the closest single star to the Sun; only the three stars in the α Centauri system are closer. Barnard's star is also among the least magnetically active red dwarfs known2,3 and has an estimated age older than the Solar System. Its properties make it a prime target for planetary searches; various techniques with different sensitivity limits have been used previously, including radial-velocity imaging4-6, astrometry7,8 and direct imaging9, but all ultimately led to negative or null results. Here we combine numerous measurements from high-precision radial-velocity instruments, revealing the presence of a low-amplitude periodic signal with a period of 233 days. Independent photometric and spectroscopic monitoring, as well as an analysis of instrumental systematic effects, suggest that this signal is best explained as arising from a planetary companion. The candidate planet around Barnard's star is a cold super-Earth, with a minimum mass of 3.2 times that of Earth, orbiting near its snow line (the minimum distance from the star at which volatile compounds could condense). The combination of all radial-velocity datasets spanning 20 years of measurements additionally reveals a long-term modulation that could arise from a stellar magnetic-activity cycle or from a more distant planetary object. Because of its proximity to the Sun, the candidate planet has a maximum angular separation of 220 milliarcseconds from Barnard's star, making it an excellent target for direct imaging and astrometric observations in the future.
ABSTRACT
In the treatment of difficult chronic pain conditions, cognitive-perceptive approaches offer an alternative to conventional therapies. Especially phantom limb pain and complex regional pain syndrome (CRPS) are frequently treated with these promising modalities. This article provides an overview of the most important cognitive-perceptive therapies and the research results concerning their clinical efficacy. In addition, we discuss their neurobiological foundation and clinical perspectives.
Subject(s)
Chronic Pain/rehabilitation , Cognitive Behavioral Therapy/methods , Pain Perception , Chronic Pain/psychology , Combined Modality Therapy , Complex Regional Pain Syndromes/psychology , Complex Regional Pain Syndromes/rehabilitation , Humans , Illusions/psychology , Imagination , Neurological Rehabilitation/methods , Phantom Limb/psychology , Phantom Limb/rehabilitationABSTRACT
Complex regional pain syndrome (CRPS) is a poorly understood pain disorder of the limbs. Maladaptive cortical plasticity has been shown to play a major role in its pathophysiological presentation. Recently, there is increasing interest in the role of the basal ganglia (BG), since clinical findings and neuroimaging studies point to possible BG involvement in CRPS. CRPS symptoms are often characterized by movement disorders associated with BG dysfunction. Very frequently, dystonia and tremor are reported and, to a lesser extent, myoclonus. Neuroimaging studies present inconsistent findings concerning altered brain networks and mainly focus on cortical areas. Subcortical contribution to this disorder has so far been neglected. Clinical data presenting BG dysfunction-related movement disorders in CRPS patients raise the hypothesis of BG dysfunction in this syndrome. Moreover, several neuroimaging studies documented abnormalities in the BG and in the frontal, parietal and limbic cortical areas. These regions are functionally and anatomically connected in motor, pain and working memory networks. Put together, these findings call for further characterization of the dynamic cortical and subcortical interactions in CRPS. SIGNIFICANCE: This paper presents an overview of our current knowledge about BG pathology in CRPS. A better understanding of the involvement of the BG in the CRPS pathology holds the potential for developing and improving efficacious, mechanism-based treatment modalities.
Subject(s)
Basal Ganglia Diseases/etiology , Complex Regional Pain Syndromes/complications , Basal Ganglia Diseases/diagnostic imaging , Basal Ganglia Diseases/physiopathology , Complex Regional Pain Syndromes/diagnostic imaging , Complex Regional Pain Syndromes/physiopathology , Humans , Movement Disorders/etiologyABSTRACT
Staphylococcus aureus sequence type (ST)398, which is commonly found as a colonization strain in pig farming, is emerging more frequently as the cause of human infections. In this study, we analysed ST398 of porcine and human origin at the genetic, protein and immunogenic levels. Although genetic analysis of the genes encoding the major virulence factors revealed the presence of the same genes in all strains studied, the results demonstrated spa type crossing alterations in adhesion abilities in addition to a strongly enhanced lysis activity directly linked to impaired clearance attributable to polymorphonuclear leukocytes (PMNs). This change in virulence pattern indicates high heterogenicity in the ST398 pool that is not based on a different genetic make-up, but probably on variations in the genetic regulation systems. These modifications, which are tightly connected to pathogenicity, cannot be detected by conventional diagnostic methods.
Subject(s)
Staphylococcal Infections/epidemiology , Staphylococcal Infections/veterinary , Staphylococcus aureus/classification , Staphylococcus aureus/isolation & purification , Adult , Animals , Bacterial Adhesion , Cell Death , Female , Genotype , Humans , Male , Middle Aged , Neutrophils/microbiology , Phenotype , Staphylococcal Infections/microbiology , Staphylococcus aureus/genetics , Staphylococcus aureus/pathogenicity , Swine , Swine Diseases/microbiology , Virulence , Young AdultABSTRACT
The text is a reflexion about the political implications and practices related to the concept of integral attention of woman's health, in its several interpretations, for reference on the women multi-dimensionality.