14 research outputs found

    TESS Hunt for Young and Maturing Exoplanets (THYME). III. A Two-planet System in the 400 Myr Ursa Major Group

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    Exoplanets can evolve significantly between birth and maturity as their atmospheres, orbits, and structures are shaped by their environment. Young planets (<<1 Gyr) offer the opportunity to probe these sculpting processes. However, most of the known young planets orbit prohibitively faint stars. We present the discovery of two planets transiting HD 63433 (TOI 1726, TIC 130181866), a young Sun-like (M∗=0.99±0.03M_*=0.99\pm0.03) star. Through kinematics, lithium abundance, and rotation, we confirm that HD 63433 is a member of the Ursa Major moving group (τ=414±23\tau=414\pm23 Myr). Based on the TESS light curve and updated stellar parameters, the planet radii are 2.15±0.10R⊕2.15\pm0.10R_\oplus and 2.67±0.12R⊕2.67\pm0.12R_\oplus, the orbital periods are 7.11 and 20.55 days, and the orbital eccentricities are lower than abut 0.2. Using HARPS-N velocities, we measure the Rossiter-McLaughlin signal of the inner planet, demonstrating the orbit is prograde. Since the host star is bright (V=6.9), both planets are amenable to transmission spectroscopy, radial velocity measurements of their masses, and more precise determination of the stellar obliquity. This system is therefore poised to play an important role in our understanding of planetary system evolution in the first billion years after formation

    Expression and function of G-protein-coupled receptorsin the male reproductive tract

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    This review focuses on the expression and function of muscarinic acetylcholine receptors (mAChRs), α1-adrenoceptors and relaxin receptors in the male reproductive tract. The localization and differential expression of mAChR and α1-adrenoceptor subtypes in specific compartments of the efferent ductules, epididymis, vas deferens, seminal vesicle and prostate of various species indicate a role for these receptors in the modulation of luminal fluid composition and smooth muscle contraction, including effects on male fertility. Furthermore, the activation of mAChRs induces transactivation of the epidermal growth factor receptor (EGFR) and the Sertoli cell proliferation. The relaxin receptors are present in the testis, RXFP1 in elongated spermatids and Sertoli cells from rat, and RXFP2 in Leydig and germ cells from rat and human, suggesting a role for these receptors in the spermatogenic process. The localization of both receptors in the apical portion of epithelial cells and smooth muscle layers of the vas deferens suggests an involvement of these receptors in the contraction and regulation of secretion.Esta revisĂŁo enfatiza a expressĂŁo e a função dos receptores muscarĂ­nicos, adrenoceptores α1 e receptores para relaxina no sistema reprodutor masculino. A expressĂŁo dos receptores muscarĂ­nicos e adrenoceptores α1 em compartimentos especĂ­ficos de dĂșctulos eferentes, epidĂ­dimo, ductos deferentes, vesĂ­cula seminal e prĂłstata de vĂĄrias espĂ©cies indica o envolvimento destes receptores na modulação da composição do fluido luminal e na contração do mĂșsculo liso, incluindo efeitos na fertilidade masculina. AlĂ©m disso, a ativação dos receptores muscarĂ­nicos leva Ă  transativação do receptor para o fator crescimento epidermal e proliferação das cĂ©lulas de Sertoli. Os receptores para relaxina estĂŁo presentes no testĂ­culo, RXFP1 nas espermĂĄtides alongadas e cĂ©lulas de Sertoli de rato e RXFP2 nas cĂ©lulas de Leydig e germinativas de ratos e humano, sugerindo o envolvimento destes receptores no processo espermatogĂȘnico. A localização de ambos os receptores na porção apical das cĂ©lulas epiteliais e no mĂșsculo liso dos ductos deferentes de rato sugere um papel na contração e na regulação da secreção.Fundação de Amparo Ă  Pesquisa do Estado de SĂŁo Paulo (FAPESP)Conselho Nacional de Desenvolvimento CientĂ­fico e TecnolĂłgico (CNPq)Universidade Federal de SĂŁo Paulo (UNIFESP) Escola Paulista de Medicina Departamento de FarmacologiaUNIFESP, EPM, Depto. de FarmacologiaSciEL

    Expression and function of G-protein-coupled receptorsin the male reproductive tract

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    Tying seismic data to geologic information from core data: an example from ODP Leg 177

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    The integration of seismic data with core data provides ground-truth toa structural interpretation of seismic data.The most important difficulty that arises in an integration effort isthe correct translation between the different scales of the core dataand the seismic data.In the absence of check-shots, detailed knowledge of the velocitystructure at the drilling locations is required, either from downholelogging measurements, velocity analysis of the seismic data, or directmeasurements on core samples.Three of the seven drill-sites during ODP (Ocean Drilling Program) Leg177 in the south-eastern Atlantic were located on the Agulhas Ridge andconnected through eight seismic profiles.Synthetic seismograms created from velocity and density measurements onselected core samples generally show a good agreement with real seismicdata with respect to amplitude and waveform, whereas timing of theevents is troublesome.The use of velocity profiles with inaccurate sections along cores, afalse depth scale due to recovery problems, and inaccuracies in thepositioning during both seismic and coring operations are the mainshortcomings of this method.The main reflectors identified on seismic data correspond to hiatuses orperiods of reduced sedimentation rates, and correlate well with densityvariations.In this way the cored data provide a calibration tool for the overallgeological interpretation of the seismic sections
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