294 research outputs found

    The HATNet and HATSouth Exoplanet Surveys

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    The Hungarian-made Automated Telescope Network (HATNet) has been in operation since 2003, with the key science goal being the discovery and accurate characterization of transiting extrasolar planets (TEPs) around bright stars. Using six small, 11\,cm\ aperture, fully automated telescopes in Arizona and Hawaii, as of 2017 March, it has discovered and accurately characterized 67 such objects. The HATSouth network of telescopes has been in operation since 2009, using slightly larger, 18\,cm diameter optical tubes. It was the first global network of telescopes using identical instrumentation. With three premier sites spread out in longitude (Chile, Namibia, Australia), the HATSouth network permits round-the-clock observations of a 128 square arcdegree swath of the sky at any given time, weather permitting. As of this writing, HATSouth has discovered 36 transiting exoplanets. Many of the altogether ~100 HAT and HATSouth exoplanets were the first of their kind. They have been important contributors to the rapidly developing field of exoplanets, motivating and influencing observational techniques, theoretical studies, and also actively shaping future instrumentation for the detection and characterization of such objects.Comment: Invited review chapter, accepted for publication in "Handbook of Exoplanets", edited by H.J. Deeg and J.A. Belmonte, Springer Reference Work

    HATS-17b: A Transiting Compact Warm Jupiter in a 16.3 Days Circular Orbit

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    We report the discovery of HATS-17b, the first transiting warm Jupiter of the HATSouth network. HATS-17b transits its bright (V=12.4) G-type (M⋆_{\star}=1.131 ±\pm 0.030 M⊙_{\odot}, R⋆_{\star}=1.091−0.046+0.070^{+0.070}_{-0.046} R⋆_{\star}) metal-rich ([Fe/H]=+0.3 dex) host star in a circular orbit with a period of P=16.2546 days. HATS-17b has a very compact radius of 0.777 ±\pm 0.056 RJ_J given its Jupiter-like mass of 1.338 ±\pm 0.065 MJ_J. Up to 50% of the mass of HATS-17b may be composed of heavy elements in order to explain its high density with current models of planetary structure. HATS-17b is the longest period transiting planet discovered to date by a ground-based photometric survey, and is one of the brightest transiting warm Jupiter systems known. The brightness of HATS-17b will allow detailed follow-up observations to characterize the orbital geometry of the system and the atmosphere of the planet.Comment: 12 page, 8 figures, submitted to A

    Solution NMR assignment of the C-terminal domain of human chTOG

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    The microtubule regulatory protein colonic and hepatic tumor overexpressed gene (chTOG), also known as cytoskeleleton associated protein 5 (CKAP5) plays an important role in organizing the cytoskeleton and in particular in the assembly of k-fibres in mitosis. Recently, we dissected the hitherto poorly understood C-terminus of this protein by discovering two new domains—a cryptic TOG domain (TOG6) and a smaller, helical domain at the very C-terminus. It was shown that the C-terminal domain is important for the interaction with the TACC domain in TACC3 during the assembly of k-fibres in a ternary complex that also includes clathrin. Here we now present the solution NMR assignment of the chTOG C-terminal domain which confirms our earlier prediction that it is mainly made of α-helices. However, the appearance of the 1H–15N HSQC spectrum is indicative of the presence of a considerable amount of unstructured and possibly flexible portions of protein in the domain

    Mechanosensitive Enteric Neurons in the Myenteric Plexus of the Mouse Intestine

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    BACKGROUND: Within the gut the autonomous enteric nervous system (ENS) is able to sense mechanical stimuli and to trigger gut reflex behaviour. We previously proposed a novel sensory circuit in the ENS which consists of multifunctional rapidly adapting mechanosensitive enteric neurons (RAMEN) in the guinea pig. The aim of this study was to validate this concept by studying its applicability to other species or gut regions. METHODOLOGY/PRINCIPAL FINDINGS: We deformed myenteric ganglia in the mouse small and large intestine and recorded spike discharge using voltage sensitive dye imaging. We also analysed expression of markers hitherto proposed to label mouse sensory myenteric neurons in the ileum (NF145kD) or colon (calretinin). RAMEN constituted 22% and 15% of myenteric neurons per ganglion in the ileum and colon, respectively. They encoded dynamic rather than sustained deformation. In the colon, 7% of mechanosensitive neurons fired throughout the sustained deformation, a behaviour typical for slowly adapting echanosensitive neurons (SAMEN). RAMEN and SAMEN responded directly to mechanical deformation as their response remained unchanged after synaptic blockade in low Ca(++)/high Mg(++). Activity levels of RAMEN increased with the degree of ganglion deformation. Recruitment of more RAMEN with stronger stimuli may suggest low and high threshold RAMEN. The majority of RAMEN were cholinergic but most lacked expression of NF145kD or calretinin. CONCLUSIONS/SIGNIFICANCE: We showed for the first time that fundamental properties of mechanosensitive enteric neurons, such as firing pattern, encoding of dynamic deformation, cholinergic phenotype and their proportion, are conserved across species and regions. We conclude that RAMEN are important for mechanotransduction in the ENS. They directly encode dynamic changes in force as their firing frequency is proportional to the degree of deformation of the ganglion they reside in. The additional existence of SAMEN in the colon is likely an adaptation to colonic motor patterns which consist of phasic and tonic contractions

    TOI-3235 b: A Transiting Giant Planet around an M4 Dwarf Star

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    We present the discovery of TOI-3235 b, a short-period Jupiter orbiting an M dwarf with a stellar mass close to the critical mass at which stars transition from partially to fully convective. TOI-3235 b was first identified as a candidate from TESS photometry and confirmed with radial velocities from ESPRESSO and ground-based photometry from HATSouth, MEarth-South, TRAPPIST-South, LCOGT, and ExTrA. We find that the planet has a mass of 0.665 ± 0.025 M J and a radius of 1.017 ± 0.044 R J. It orbits close to its host star, with an orbital period of 2.5926 days but has an equilibrium temperature of ≈ 604 K, well below the expected threshold for radius inflation of hot Jupiters. The host star has a mass of 0.3939 ± 0.0030 M ☉, a radius of 0.3697 ± 0.0018 R ☉, an effective temperature of 3389 K, and a J-band magnitude of 11.706 ± 0.025. Current planet formation models do not predict the existence of gas giants such as TOI-3235 b around such low-mass stars. With a high transmission spectroscopy metric, TOI-3235 b is one of the best-suited giants orbiting M dwarfs for atmospheric characterization

    Predicting GP visits: A multinomial logistic regression investigating GP visits amongst a cohort of UK patients living with Myalgic encephalomyelitis

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    Background Myalgic Encephalomyelitis (ME) is a chronic condition whose status within medicine is the subject of on-going debate. Some medical professionals regard it as a contentious illness. Others report a lack of confidence with diagnosis and management of the condition. The genesis of this paper was a complaint, made by an ME patient, about their treatment by a general practitioner. In response to the complaint, Healthwatch Trafford ran a patient experience-gathering project. Method Data was collected from 476 participants (411 women and 65 men), living with ME from across the UK. Multinomial logistic regression investigated the predictive utility of length of time with ME; geographic location (i.e. Manchester vs. rest of UK); trust in GP; whether the patient had received a formal diagnosis; time taken to diagnosis; and gender. The outcome variable was number of GP visits per year. Results All variables, with the exception of whether the patient had received a formal diagnosis, were significant predictors. Conclusions Relationships between ME patients and their GPs are discussed and argued to be key to the effective delivery of care to this patient cohort. Identifying potential barriers to doctor patient interactions in the context of ME is crucial

    HATS-47b, HATS-48Ab, HATS-49b and HATS-72b: Four Warm Giant Planets Transiting K Dwarfs

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    We report the discovery of four transiting giant planets around K dwarfs. The planets HATS-47b, HATS-48Ab, HATS49b, and HATS-72b have masses of 0.369+ 0.0210.031MJ, 0.243+ 0.0300.022 MJ, 0.353+ 0.0270.038 MJ, and 0.1254. 0.0039 MJ, respectively, and radii of 1.117. 0.014 RJ, 0.800. 0.015 RJ, 0.765. 0.013 RJ, and 0.7224. 0.0032 RJ, respectively. The planets orbit close to their host stars with orbital periods of 3.9228 days, 3.1317 days, 4.1480 days, and 7.3279 days, respectively. The hosts are main-sequence K dwarfs with masses of 0.674+ 0.0120.016.M, 0.7279. 0.0066.M, 0.7133. 0.0075.M, and 0.7311. 0.0028, and with V-band magnitudes of V = 14.829. 0.010, 14.35. 0.11, 14.998. 0.040 and 12.469. 0.010. The super-Neptune HATS-72b (a.k.a. WASP-191b and TOI 294.01) was independently identified as a transiting planet candidate by the HATSouth, WASP, and TESS surveys, and we present a combined analysis of all of the data gathered by each of these projects (and their follow-up programs). An exceptionally precise mass is measured for HATS-72b thanks to high-precision radial velocity (RV) measurements obtained with VLT/ESPRESSO, FEROS, HARPS, and Magellan/PFS. We also incorporate TESS observations of the warm Saturn-hosting systems HATS-47 (a.k.a. TOI.1073.01), HATS-48A, and HATS-49. HATS-47 was independently identified as a candidate by the TESS team, while the other two systems were not previously identified from the TESS data. The RV orbital variations are measured for these systems using Magellan/PFS. HATS-48A has a resolved 5.. 4 neighbor in Gaia.DR2, which is a common-proper-motion binary star companion to HATS-48A with a mass of 0.22.M and a current projected physical separation of similar to 1400 au

    Change in brain activity through virtual reality-based brain-machine communication in a chronic tetraplegic subject with muscular dystrophy

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    <p>Abstract</p> <p>Background</p> <p>For severely paralyzed people, a brain-computer interface (BCI) provides a way of re-establishing communication. Although subjects with muscular dystrophy (MD) appear to be potential BCI users, the actual long-term effects of BCI use on brain activities in MD subjects have yet to be clarified. To investigate these effects, we followed BCI use by a chronic tetraplegic subject with MD over 5 months. The topographic changes in an electroencephalogram (EEG) after long-term use of the virtual reality (VR)-based BCI were also assessed. Our originally developed BCI system was used to classify an EEG recorded over the sensorimotor cortex in real time and estimate the user's motor intention (MI) in 3 different limb movements: feet, left hand, and right hand. An avatar in the internet-based VR was controlled in accordance with the results of the EEG classification by the BCI. The subject was trained to control his avatar via the BCI by strolling in the VR for 1 hour a day and then continued the same training twice a month at his home.</p> <p>Results</p> <p>After the training, the error rate of the EEG classification decreased from 40% to 28%. The subject successfully walked around in the VR using only his MI and chatted with other users through a voice-chat function embedded in the internet-based VR. With this improvement in BCI control, event-related desynchronization (ERD) following MI was significantly enhanced (<it>p </it>< 0.01) for feet MI (from -29% to -55%), left-hand MI (from -23% to -42%), and right-hand MI (from -22% to -51%).</p> <p>Conclusions</p> <p>These results show that our subject with severe MD was able to learn to control his EEG signal and communicate with other users through use of VR navigation and suggest that an internet-based VR has the potential to provide paralyzed people with the opportunity for easy communication.</p
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