305 research outputs found

    Brain abscesses in a patient with a patent foramen ovale: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Brain abscesses arising from right-to-left cardiac shunting are very rare in adults.</p> <p>Case presentation</p> <p>We describe the case of a 47-year-old non-hispanic white male with periodontal disease who developed several brain abscesses caused by <it>Streptococcus intermedius</it>. A comprehensive workup revealed a patent foramen ovale with oral flora as the only plausible explanation for the brain abscesses.</p> <p>Conclusion</p> <p>Based on this case and the relevant literature, we suggest an association between a silent patent foramen ovale, paradoxical microbial dissemination to the brain, and the development of brain abscesses.</p

    The path to Z And-type outbursts: The case of V426 Sagittae (HBHA 1704-05)

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    Context. The star V426 Sge (HBHA 1704-05), originally classified as an emission-line object and a semi-regular variable, brightened at the beginning of August 2018, showing signatures of a symbiotic star outburst. Aims. We aim to confirm the nature of V426 Sge as a classical symbiotic star, determine the photometric ephemeris of the light minima, and suggest the path from its 1968 symbiotic nova outburst to the following 2018 Z And-type outburst. Methods. We re-constructed an historical light curve (LC) of V426 Sge from approximately the year 1900, and used original low- (R ∼ 500-1500; 330-880 nm) and high-resolution (R ∼ 11 000-34 000; 360-760 nm) spectroscopy complemented with Swift-XRT and UVOT, optical UBVRCIC and near-infrared JHKL photometry obtained during the 2018 outburst and the following quiescence. Results. The historical LC reveals no symbiotic-like activity from ∼1900 to 1967. In 1968, V426 Sge experienced a symbiotic nova outburst that ceased around 1990. From approximately 1972, a wave-like orbitally related variation with a period of 493.4 ± 0.7 days developed in the LC. This was interrupted by a Z And-type outburst from the beginning of August 2018 to the middle of February 2019. At the maximum of the 2018 outburst, the burning white dwarf (WD) increased its temperature to ? 2 × 105 K, generated a luminosity of ∼7 × 1037 (d/3.3 kpc)2 erg s-1 and blew a wind at the rate of ∼3 × 10-6 M yr-1. Our spectral energy distribution models from the current quiescent phase reveal that the donor is a normal M4-5 III giant characterised with Teff ∼ 3400 K, RG ∼ 106 (d/3.3 kpc) R and LG ∼ 1350 (d/3.3 kpc)2 L and the accretor is a low-mass ∼0.5 M WD. Conclusions. During the transition from the symbiotic nova outburst to the quiescent phase, a pronounced sinusoidal variation along the orbit develops in the LC of most symbiotic novae. The following eventual outburst is of Z And-type, when the accretion by the WD temporarily exceeds the upper limit of the stable burning. At this point the system becomes a classical symbiotic star.Fil: Skopal, A.. Astronomical Institute Slovak Academy Of Sciences; EslovaquiaFil: Shugarov, S. Y.. Lomonosov Moscow State University; Rusia. Astronomical Institute Slovak Academy Of Sciences; EslovaquiaFil: Munari, U.. Osservatorio Astronomico Di Padova; ItaliaFil: Masetti, N.. Inaf Istituto Di Astrofisica Spaziale E Fisica Cosmica, Bologna; Italia. Universidad Andrés Bello; ChileFil: Marchesini, Ezequiel Joaquín. Università di Torino; Italia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Komzík, R. M.. Astronomical Institute Slovak Academy Of Sciences; EslovaquiaFil: Kundra, E.. Astronomical Institute Slovak Academy Of Sciences; EslovaquiaFil: Shagatova, N.. Astronomical Institute Slovak Academy Of Sciences; EslovaquiaFil: Tarasova, T. N.. Crimean Astrophysical Observatory Ras; RusiaFil: Buil, C.. Castanet Tolosan Observatory; FranciaFil: Boussin, C.. Observatoire de L'eridan Et de la Chevelure de Bérénice; FranciaFil: Shenavrin, V. I.. Lomonosov Moscow State University; RusiaFil: Hambsch, F. J.. Istituto Nazionale di Astrofisica; ItaliaFil: Dallaporta, S.. Istituto Nazionale di Astrofisica; ItaliaFil: Frigolé, Cecilia Andrea. Istituto Nazionale di Astrofisica; ItaliaFil: Gardey, Juan Cruz. Observatoire de la Tourbière; FranciaFil: Zubareva, A.. Institute Of Astronomy Of The Russian Academy Of Sciences; Rusia. Lomonosov Moscow State University; RusiaFil: Dubovský, P. A.. Vihorlat Observatory; EslovaquiaFil: Kroll, P.. Sonneberg Observatory; Alemani

    On the nature of the candidate T-Tauri star V501 Aurigae

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    We report new multi-colour photometry and high-resolution spectroscopic observations of the long-period variable V501 Aur, previously considered to be a weak-lined T-Tauri star belonging to the Taurus-Auriga star-forming region. The spectroscopic observations reveal that V501 Aur is a single-lined spectroscopic binary system with a 68.8-day orbital period, a slightly eccentric orbit (e ~ 0.03), and a systemic velocity discrepant from the mean of Taurus-Auriga. The photometry shows quasi-periodic variations on a different, ~55-day timescale that we attribute to rotational modulation by spots. No eclipses are seen. The visible object is a rapidly rotating (vsini ~ 25 km/s) early K star, which along with the rotation period implies it must be large (R > 26.3 Rsun), as suggested also by spectroscopic estimates indicating a low surface gravity. The parallax from the Gaia mission and other independent estimates imply a distance much greater than the Taurus-Auriga region, consistent with the giant interpretation. Taken together, this evidence together with a re-evaluation of the LiI~λ\lambda6707 and Hα\alpha lines shows that V501 Aur is not a T-Tauri star, but is instead a field binary with a giant primary far behind the Taurus-Auriga star-forming region. The large mass function from the spectroscopic orbit and a comparison with stellar evolution models suggest the secondary may be an early-type main-sequence star.Comment: 13 pages, 7 figures. Accepted to MNRA

    Long-term photometry of IC 348 with the Young Exoplanet Transit Initiative network

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    We present long-term photometric observations of the young open cluster IC 348 with a baseline time-scale of 2.4 yr. Our study was conducted with several telescopes from the Young Exoplanet Transit Initiative (YETI) network in the Bessel R band to find periodic variability of young stars. We identified 87 stars in IC 348 to be periodically variable; 33 of them were unreported before. Additionally, we detected 61 periodic non-members of which 41 are new discoveries. Our wide field of view was the key to those numerous newly found variable stars. The distribution of rotation periods in IC 348 has always been of special interest. We investigate it further with our newly detected periods but we cannot find a statistically significant bimodality. We also report the detection of a close eclipsing binary in IC 348 composed of a low-mass stellar component (M ≳ 0.09 M⊙) and a K0 pre-main-sequence star (M ≈ 2.7 M⊙). Furthermore, we discovered three detached binaries among the background stars in our field of view and confirmed the period of a fourth one

    The MD Anderson prostate cancer patient-derived xenograft series (MDA PCa PDX) captures the molecular landscape of prostate cancer and facilitates marker-driven therapy development

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    BACKGROUND: Advances in prostate cancer (PCa) lag behind other tumor types partly due to the paucity of models reflecting key milestones in PCa progression. OBJECTIVE: To develop clinically relevant PCa models. DESIGN: Since 1996 we have generated clinically annotated patient-derived xenografts (PDXs) (the MDA PCa PDX series) linked to specific phenotypes reflecting all aspects of clinical PCa. RESULTS: We studied two cell line-derived xenografts and the first 80 PDXs derived from 47 human PCa donors. Of these, 47 PDXs derived from 22 donors are working models and can be expanded either as cell lines (MDA PCa 2a and 2b) or PDXs. The histopathologic, genomic, and molecular characteristics (AR, ERG, and PTEN loss) maintain fidelity with the human tumor and correlate with published findings. PDX growth response to mouse castration and targeted therapy illustrate their clinical utility. Comparative genomic hybridization and sequencing show significant differences in oncogenic pathways in pairs of PDXs derived from different areas of the same tumor. We also identified a recurrent focal deletion in an area that includes the SPOPL gene in PDXs derived from 7 human donors out of 28 studied (25%). SPOPL is a SPOP paralog, and SPOP mutations define a molecular subclass of PCa. SPOPL deletions are found in 7% of TCGA PCas, which suggests that our cohort is a reliable platform for targeted drug development. CONCLUSIONS: The MDA PCa PDX series is a dynamic resource that captures the molecular landscape of PCas progressing under novel treatments and enables optimization of PCa-specific, marker-driven therapy

    Revisiting the Transit Timing Variations in the TrES-3 and Qatar-1 Systems with TESS Data

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    We present and analyze 58 transit light curves of TrES-3b and 98 transit light curves of Qatar-1b, observed by the Transiting Exoplanet Survey Satellite, plus two transit light curves of Qatar-1b, observed by us, using a ground-based 1.23 m telescope. These light curves are combined with the best-quality light curves taken from the Exoplanet Transit Database and the literature. The precisely determined midtransit times from these light curves enable us to obtain the refined orbital ephemerides, with improved precision, for both hot Jupiters. From the timing analysis, we find indications of the presence of transit timing variations (TTVs) in both systems. Since the observed TTVs are unlikely to be short-term and periodic, the possibility of additional planets in orbits close to TrES-3b and Qatar-1b is ruled out. The possible causes of long-term TTVs, such as orbital decay, apsidal precession, the Applegate mechanism, and line-of-sight acceleration, are also examined. However, none of these possibilities are found to explain the observed TTV of TrES-3b. In contrast to this, line-of-sight acceleration appears to be a plausible explanation for the observed TTV of Qatar-1b. In order to confirm these findings, further high-precision transit and radial velocity observations of both systems would be worthwhile

    An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics

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    For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types
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