207 research outputs found

    Presence of a novel epithelial antigen on rat cerebellar cell lines as detected by a monoclonal antibody

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    We have derived a monoclonal antibody, MCAb 51, following immunization of BALB/c mice with a Rous sarcoma virus-transformed rat cerebellar cell line. When assayed by immunofluorescence on primary rat cerebellar cultures MCAb 51 recognizes only islands of cells with an epitheloid morphology. Double-label immunofluorescence experiments with MCAb 51 and antisera to tetanus toxin, glial fibrillary acidic protein, galactocerebroside and fibronectin reveal that these cells do not appear to be neurons, astrocytes, oligodendrocytes, or fibroblasts, respectively. In contrast, cells from kidney, liver, tongue and choroid plexus epithelium are positive for the antigen. Of 12 Rous sarcoma virus-transformed cell lines, in contrast to 2 out of 9 chemically transformed lines, 11 exhibit the MCAb 51 antigen. These findings demonstrate that MCAb 51 recognizes an epithelial cell surface marker. Possible explanations for the difference in the expression of the antigen on Rous sarcoma virus and chemically transformed neural lines are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25625/1/0000175.pd

    Phase II study of capecitabine and oxaliplatin given prior to and concurrently with preoperative pelvic radiotherapy in patients with locally advanced rectal cancer

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    This multicentre phase II study evaluated the efficacy and safety of preoperative capecitabine plus oxaliplatin and radiotherapy (RT) in patients with locally advanced rectal cancer (T3/T4 rectal adenocarcinoma with or without nodal involvement). Treatment consisted of one cycle of XELOX (capecitabine 1000 mg m−2 bid on days 1–14 and oxaliplatin 130 mg m−2 on day 1), followed by RT (1.8 Gy fractions 5 days per week for 5 weeks) plus CAPOX (capecitabine 825 mg m−2 bid on days 22–35 and 43–56, and oxaliplatin 50 mg m−2 on days 22, 29, 43 and 50). Surgery was recommended 5 weeks after completion of chemoradiotherapy. The primary end point was pathological complete tumour response (pCR). Sixty patients were enrolled. In the intent-to-treat population, the pCR rate was 23% (95% CI: 13–36%). 58 patients underwent surgery; R0 resection was achieved in 57 (98%) patients, including all 5 patients with T4 tumours. Sphincter preservation was achieved in 49 (84%) patients. Tumour and/or nodal downstaging was observed in 39 (65%) patients. The most common grade 3/4 adverse events were diarrhoea (20%) and lymphocytopaenia (43%). Preoperative capecitabine, oxaliplatin and RT achieved encouraging rates of pCR, R0 resection, sphincter preservation and tumour downstaging in patients with locally advanced rectal cancer

    Characterising TOI-732 b and c: New insights into the M-dwarf radius and density valley

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    TOI-732 is an M dwarf hosting two transiting planets that are located on the two opposite sides of the radius valley. By doubling the number of available space-based observations and increasing the number of radial velocity (RV) measurements, we aim at refining the parameters of TOI-732 b and c. We also use the results to study the slope of the radius valley and the density valley for a well-characterised sample of M-dwarf exoplanets. We performed a global MCMC analysis by jointly modelling ground-based light curves and CHEOPS and TESS observations, along with RV time series both taken from the literature and obtained with the MAROON-X spectrograph. The slopes of the M-dwarf valleys were quantified via a Support Vector Machine (SVM) procedure. TOI-732 b is an ultrashort-period planet (P∌0.77P\sim0.77 d) with a radius Rb=1.325−0.058+0.057R_b=1.325_{-0.058}^{+0.057} R⊕R_{\oplus} and a mass Mb=2.46±0.19M_b=2.46\pm0.19 M⊕M_{\oplus} (mean density ρb=5.8−0.8+1.0\rho_b=5.8_{-0.8}^{+1.0} g cm−3^{-3}), while the outer planet at P∌12.25P\sim12.25 d has Rc=2.39−0.11+0.10R_c=2.39_{-0.11}^{+0.10} R⊕R_{\oplus}, Mc=8.04−0.48+0.50M_c=8.04_{-0.48}^{+0.50} M⊕M_{\oplus}, and thus ρc=3.24−0.43+0.55\rho_c=3.24_{-0.43}^{+0.55} g cm−3^{-3}. Also taking into account our interior structure calculations, TOI-732 b is a super-Earth and TOI-732 c is a mini-Neptune. Following the SVM approach, we quantified dlog⁥Rp,valley/dlog⁥P=−0.065−0.013+0.024\mathrm{d}\log{R_{p,{\mathrm{valley}}}}/\mathrm{d}\log{P}=-0.065_{-0.013}^{+0.024}, which is flatter than for Sun-like stars. In line with former analyses, we note that the radius valley for M-dwarf planets is more densely populated, and we further quantify the slope of the density valley as dlogâĄÏ^valley/dlog⁥P=−0.02−0.04+0.12\mathrm{d}\log{\hat{\rho}_{\mathrm{valley}}}/\mathrm{d}\log{P}=-0.02_{-0.04}^{+0.12}. Compared to FGK stars, the weaker dependence of the position of the radius valley on the orbital period might indicate that the formation shapes the radius valley around M dwarfs more strongly than the evolution mechanisms.Comment: 28 pages (17 in the main text), 18 figures (9 in the main text), 11 tables (7 in the main text). Accepted for publication in A&

    CHEOPS observations of KELT-20 b/MASCARA-2 b: An aligned orbit and signs of variability from a reflective dayside

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    Occultations are windows of opportunity to indirectly peek into the dayside atmosphere of exoplanets. High-precision transit events provide information on the spin-orbit alignment of exoplanets around fast-rotating hosts. We aim to precisely measure the planetary radius and geometric albedo of the ultra-hot Jupiter (UHJ) KELT-20 b as well as the system's spin-orbit alignment. We obtained optical high-precision transits and occultations of KELT-20 b using CHEOPS observations in conjunction with the simultaneous TESS observations. We interpreted the occultation measurements together with archival infrared observations to measure the planetary geometric albedo and dayside temperatures. We further used the host star's gravity-darkened nature to measure the system's obliquity. We present a time-averaged precise occultation depth of 82(6) ppm measured with seven CHEOPS visits and 131(+8/-7) ppm from the analysis of all available TESS photometry. Using these measurements, we precisely constrain the geometric albedo of KELT-20 b to 0.26(0.04) and the brightness temperature of the dayside hemisphere to 2566(+77/-80) K. Assuming Lambertian scattering law, we constrain the Bond albedo to 0.36(+0.04/-0.05) along with a minimal heat transfer to the night side. Furthermore, using five transit observations we provide stricter constraints of 3.9(1.1) degrees on the sky-projected obliquity of the system. The aligned orbit of KELT-20 b is in contrast to previous CHEOPS studies that have found strongly inclined orbits for planets orbiting other A-type stars. The comparably high planetary geometric albedo of KELT-20 b corroborates a known trend of strongly irradiated planets being more reflective. Finally, we tentatively detect signs of temporal variability in the occultation depths, which might indicate variable cloud cover advecting onto the planetary day side.Comment: 27 pages, 15 figures, Accepted for publication in Astronomy & Astrophysic

    A framework to assess welfare mix and service provision models in health care and social welfare: case studies of two prominent Italian regions

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    BACKGROUND: The mechanisms through which the relationships among public institutions, private providers and families affect care and service provision systems are puzzling. How can we understand the mechanisms in these contexts? Which elements should we explore to capture the complexity of care provision? The aim of our study is to provide a framework that can help read and reframe these puzzling care provision mechanisms in a welfare mix context. METHODS: First, we develop a theoretical framework for understanding how service provision occurs in care systems that are characterised by a variety of relationships between multiple actors, using an evidence-based approach that looks at both public and private expenditures and the number of users relative to the level of needs coverage and compared with declared values and political rhetoric. Second, we test this framework in two case studies built on data from two prominent Italian regions, Lombardy and Emilia-Romagna. We argue that service provision models depend on the interplay among six conceptual elements: policy values, governance rules, resources, nature of the providers, service standards and eligibility criteria. RESULTS: Our empirical study shows that beneath the relevant differences in values and political rhetoric between the case studies of the two Italian regions, there is a surprising isomorphism in service standards and the levels of covering the population’s needs. CONCLUSION: The suggested framework appears to be effective and feasible; it fosters interdisciplinary approaches and supports policy-making discussions. This study may contribute to deepening knowledge about public care service provision and institutional arrangements, which can be used to promote more effective reforms and may advance future research. Although the framework was tested on the Italian welfare system, it can be used to assess many different systems

    Three Saturn-mass planets transiting F-type stars revealed with TESS and HARPS

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    While the sample of confirmed exoplanets continues to increase, the population of transiting exoplanets around early-type stars is still limited. These planets allow us to investigate the planet properties and formation pathways over a wide range of stellar masses and study the impact of high irradiation on hot Jupiters orbiting such stars. We report the discovery of TOI-615b, TOI-622b, and TOI-2641b, three Saturn-mass planets transiting main sequence, F-type stars. The planets were identified by the Transiting Exoplanet Survey Satellite (TESS) and confirmed with complementary ground-based and radial velocity observations. TOI-615b is a highly irradiated (∌\sim1277 F⊕F_{\oplus}) and bloated Saturn-mass planet (1.69−0.06+0.05^{+0.05}_{-0.06}RJupR_{Jup} and 0.43−0.08+0.09^{+0.09}_{-0.08}MJupM_{Jup}) in a 4.66 day orbit transiting a 6850 K star. TOI-622b has a radius of 0.82−0.03+0.03^{+0.03}_{-0.03}RJupR_{Jup} and a mass of 0.30−0.08+0.07^{+0.07}_{-0.08}~MJupM_{Jup} in a 6.40 day orbit. Despite its high insolation flux (∌\sim600 F⊕F_{\oplus}), TOI-622b does not show any evidence of radius inflation. TOI-2641b is a 0.37−0.04+0.05^{+0.05}_{-0.04}MJupM_{Jup} planet in a 4.88 day orbit with a grazing transit (b = 1.04−0.06+0.05^{+0.05}_{-0.06 }) that results in a poorly constrained radius of 1.61−0.64+0.46^{+0.46}_{-0.64}RJupR_{Jup}. Additionally, TOI-615b is considered attractive for atmospheric studies via transmission spectroscopy with ground-based spectrographs and JWST\textit{JWST}. Future atmospheric and spin-orbit alignment observations are essential since they can provide information on the atmospheric composition, formation and migration of exoplanets across various stellar types.Comment: 16 pages, 17 figures, submitted to A&

    A Mini-Neptune from TESS and CHEOPS Around the 120 Myr Old AB Dor Member HIP 94235

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    The Transiting Exoplanet Survey Satellite (TESS) mission has enabled discoveries of the brightest transiting planet systems around young stars. These systems are the benchmarks for testing theories of planetary evolution. We report the discovery of a mini-Neptune transiting a bright star in the AB Doradus moving group. HIP 94235 (TOI-4399, TIC 464646604) is a V mag = 8.31 G-dwarf hosting a 3.00-0.28+0.32RùƠ mini-Neptune in a 7.7 day period orbit. HIP 94235 is part of the AB Doradus moving group, one of the youngest and closest associations. Due to its youth, the host star exhibits significant photometric spot modulation, lithium absorption, and X-ray emission. Three 0.06% transits were observed during Sector 27 of the TESS Extended Mission, though these transit signals are dwarfed by the 2% peak-To-peak photometric variability exhibited by the host star. Follow-up observations with the Characterising Exoplanet Satellite confirmed the transit signal and prevented the erosion of the transit ephemeris. HIP 94235 is part of a 50 au G-M binary system. We make use of diffraction limited observations spanning 11 yr, and astrometric accelerations from Hipparcos and Gaia, to constrain the orbit of HIP 94235 B. HIP 94235 is one of the tightest stellar binaries to host an inner planet. As part of a growing sample of bright, young planet systems, HIP 94235 b is ideal for follow-up transit observations, such as those that investigate the evaporative processes driven by high-energy radiation that may sculpt the valleys and deserts in the Neptune population

    Characterising TOI-732 b and c : new insights into the M-dwarf radius and density valley

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    Context. TOI-732 is an M dwarf hosting two transiting planets that are located on the two opposite sides of the radius valley. Inferring a reliable demographics for this type of systems is key to understanding their formation and evolution mechanisms. Aims. By doubling the number of available space-based observations and increasing the number of radial velocity (RV) measurements, we aim at refining the parameters of TOI-732 b and c. We also use the results to study the slope of the radius valley and the density valley for a well-characterised sample of M-dwarf exoplanets. Methods. We performed a global Markov chain Monte Carlo analysis by jointly modelling ground-based light curves and CHEOPS and TESS observations, along with RV time series both taken from the literature and obtained with the MAROON-X spectrograph. The slopes of the M-dwarf valleys were quantified via a support vector machine (SVM) procedure. Results. TOI-732b is an ultrashort-period planet (P = 0.76837931-0.00000042+0.0000039 days) with a radius Rb = 1.325-0.058+0.057R⊕, a mass Mb = 2.46 ± 0.19 M⊕, and thus a mean density ρb = 5.8-0.8+1.0 g cm-3, while the outer planet at P = 12.252284 ± 0.000013 days has Rc = 2.39-0.11+0.10R⊕, Mc = 8.04-0.48+0.50M⊕, and thus ρc = 3.24-0.43+0.55 g cm-3. Even with respect to the most recently reported values, this work yields uncertainties on the transit depths and on the RV semi-amplitudes that are smaller up to a factor of ~1.6 and ~2.4 for TOI-732 b and c, respectively. Our calculations for the interior structure and the location of the planets in the mass-radius diagram lead us to classify TOI-732 b as a super-Earth and TOI-732 c as a mini-Neptune. Following the SVM approach, we quantified d log Rp,valley / d logP = -0.065-0.013+0.024, which is flatter than for Sun-like stars. In line with former analyses, we note that the radius valley for M-dwarf planets is more densely populated, and we further quantify the slope of the density valley as d log ρ^valley / d log P = -0.02-0.04+0.12. Conclusions. Compared to FGK stars, the weaker dependence of the position of the radius valley on the orbital period might indicate that the formation shapes the radius valley around M dwarfs more strongly than the evolution mechanisms

    Three new brown dwarfs and a massive hot Jupiter revealed by TESS around early-type stars

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    Context. The detection and characterization of exoplanets and brown dwarfs around massive AF-type stars is essential to investigate and constrain the impact of stellar mass on planet properties. However, such targets are still poorly explored in radial velocity (RV) surveys because they only feature a small number of stellar lines and those are usually broadened and blended by stellar rotation as well as stellar jitter. As a result, the available information about the formation and evolution of planets and brown dwarfs around hot stars is limited. Aims. We aim to increase the sample and precisely measure the masses and eccentricities of giant planets and brown dwarfs transiting early-type stars detected by the Transiting Exoplanet Survey Satellite (TESS). Methods. We followed bright (V 6200 K that host giant companions (R > 7 R⊕) using ground-based photometric observations as well as high precision radial velocity measurements from the CORALIE, CHIRON, TRES, FEROS, and MINERVA-Australis spectrographs. Results. In the context of the search for exoplanets and brown dwarfs around early-type stars, we present the discovery of three brown dwarf companions, TOI-629b, TOI-1982b, and TOI-2543b, and one massive planet, TOI-1107b. From the joint analysis of TESS and ground-based photometry in combination with high precision radial velocity measurements, we find the brown dwarfs have masses between 66 and 68 MJup, periods between 7.54 and 17.17 days, and radii between 0.95 and 1.11 RJup. The hot Jupiter TOI-1107b has an orbital period of 4.08 days, a radius of 1.30 RJup, and a mass of 3.35 MJup. As a by-product of this program, we identified four low-mass eclipsing components (TOI-288b, TOI-446b, TOI-478b, and TOI-764b). Conclusions. Both TOI-1107b and TOI-1982b present an anomalously inflated radius with respect to the age of these systems. TOI-629 is among the hottest stars with a known transiting brown dwarf. TOI-629b and TOI-1982b are among the most eccentric brown dwarfs. The massive planet and the three brown dwarfs add to the growing population of well-characterized giant planets and brown dwarfs transiting AF-type stars and they reduce the apparent paucity
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