The recently discovered subdwarf B (sdB) pulsator KIC 11 558 725 is one of the 16 pulsating sdB stars detected in the Kepler field. It features a rich g-mode frequency spectrum, with a few ...low-amplitude p-modes at short periods. This makes it a promising target for a seismic study aiming to constrain the internal structure of this star, and of sdB stars ingeneral. We have obtained ground-based spectroscopic radial-velocity measurements of KIC 11 558 725 based on low-resolution spectra in the Balmer-line region, spanning the 2010 and 2011 observing seasons. From these data we have discovered that KIC 11 558 725 is a binary with period P = 10.05 d, and that the radial-velocity amplitude of the sdB star is 58 km s-1. Consequently the companion of the sdB star has a minimum mass of 0.63 M⊙, and is therefore most likely an unseen white dwarf. We analyse the near-continuous 2010–2011 Kepler light curve to reveal the orbital Doppler-beaming effect, giving rise to light variations at the 238 ppm level, which is consistent with the observed spectroscopic orbital radial-velocity amplitude of the subdwarf. We use the strongest 70 pulsation frequencies in the Kepler light curve of the subdwarf as clocks to derive a third consistent measurement of the orbital radial-velocity amplitude, from the orbital light-travel delay. The orbital radius asdBsini = 11.5 R⊙ gives rise to a light-travel time delay of 53.6 s, which causes aliasing and lowers the amplitudes of the shortest pulsation frequencies, unless the effect is corrected for. We use our high signal-to-noise average spectra to study the atmospheric parameters of the sdB star, deriving Teff = 27 910 K andlog g = 5.41 dex, and find that carbon, nitrogen and oxygen are underabundant relative to the solar mixture. Furthermore, we analyse the Kepler light curve for its pulsational content and extract more than 160 significant frequencies.We investigate the pulsation frequencies for expected period spacings and rotational splittings. We find period-spacing sequences of spherical-harmonic degrees ℓ = 1 and ℓ = 2, and we associate a large fraction of the g-modes in KIC 11 558 725 with these sequences. From frequency splittings we conclude that the subdwarf is rotating subsynchronously with respect to the orbit.
Thermodynamic parameters are reported for duplex formation of 48 self-complementary RNA duplexes containing Watson–Crick terminal base pairs (GC, AU and UA) with all 16 possible 3′ double-nucleotide ...overhangs; mimicking the structures of short interfering RNAs (siRNA) and microRNAs (miRNA). Based on nearest-neighbor analysis, the addition of a second dangling nucleotide to a single 3′ dangling nucleotide increases stability of duplex formation up to 0.8 kcal/mol in a sequence dependent manner. Results from this study in conjunction with data from a previous study A. S. O'Toole, S. Miller and M. J. Serra (2005) RNA, 11, 512. allows for the development of a refined nearest-neighbor model to predict the influence of 3′ double-nucleotide overhangs on the stability of duplex formation. The model improves the prediction of free energy and melting temperature when tested against five oligomers with various core duplex sequences. Phylogenetic analysis of naturally occurring miRNAs was performed to support our results. Selection of the effector miR strand of the mature miRNA duplex appears to be dependent upon the identity of the 3′ double-nucleotide overhang. Thermodynamic parameters for 3′ single terminal overhangs adjacent to a UA pair are also presented.
An unusual adrenal cause of hypoglycaemia O'Toole, S M; Turner, B C; Plowman, P N ...
QJM : An International Journal of Medicine,
2017-Oct-01, 2017-10-01, 20171001, Letnik:
110, Številka:
10
Journal Article
The HER2 (ERBB2) and MYC genes are commonly amplified in breast cancer, yet little is known about their molecular and clinical interaction. Using a novel chimeric mammary transgenic approach and in ...vitro models, we demonstrate markedly increased self-renewal and tumour-propagating capability of cells transformed with Her2 and c-Myc. Coexpression of both oncoproteins in cultured cells led to the activation of a c-Myc transcriptional signature and acquisition of a self-renewing phenotype independent of an epithelial-mesenchymal transition programme or regulation of conventional cancer stem cell markers. Instead, Her2 and c-Myc cooperated to induce the expression of lipoprotein lipase, which was required for proliferation and self-renewal in vitro. HER2 and MYC were frequently coamplified in breast cancer, associated with aggressive clinical behaviour and poor outcome. Lastly, we show that in HER2(+) breast cancer patients receiving adjuvant chemotherapy (but not targeted anti-Her2 therapy), MYC amplification is associated with a poor outcome. These findings demonstrate the importance of molecular and cellular context in oncogenic transformation and acquisition of a malignant stem-like phenotype and have diagnostic and therapeutic consequences for the clinical management of HER2(+) breast cancer.
We report the detection of sixteen binary systems from the Anglo-Australian Planet Search. Solutions to the radial velocity data indicate that the stars have companions orbiting with a wide range of ...masses, eccentricities and periods. Three of the systems potentially contain brown-dwarf companions while another two have eccentricities that place them in the extreme upper tail of the eccentricity distribution for binaries with periods less than 1000 d. For periods up to 12 years, the distribution of our stellar companion masses is fairly flat, mirroring that seen in other radial velocity surveys, and contrasts sharply with the current distribution of candidate planetary masses, which rises strongly below 10 M
J. When looking at a larger sample of binaries that have FGK star primaries as a function of the primary star metallicity, we find that the distribution maintains a binary fraction of ∼43 ± 4 per cent between −1.0 and +0.6 dex in metallicity. This is in stark contrast to the giant exoplanet distribution. This result is in good agreement with binary formation models that invoke fragmentation of a collapsing giant molecular cloud, suggesting that this is the dominant formation mechanism for close binaries and not fragmentation of the primary star's remnant protoplanetary disc.
Selection functions in doppler planet searches O'Toole, S. J.; Tinney, C. G.; Jones, H. R. A. ...
Monthly notices of the Royal Astronomical Society,
January 2009, Letnik:
392, Številka:
2
Journal Article
Recenzirano
Odprti dostop
We present a preliminary analysis of the sensitivity of Anglo-Australian Planet Search data to the orbital parameters of extrasolar planets. To do so, we have developed new tools for the automatic ...analysis of large-scale simulations of Doppler velocity planet search data. One of these tools is the two-dimensional Keplerian Lomb–Scargle (LS) periodogram that enables the straightforward detection of exoplanets with high eccentricities (something the standard LS periodogram routinely fails to do). We used this technique to redetermine the orbital parameters of HD 20782b, with one of the highest known exoplanet eccentricities (e= 0.97 ± 0.01). We also derive a set of detection criteria that do not depend on the distribution functions of fitted Keplerian orbital parameters (which we show are non-Gaussian with pronounced, extended wings). Using these tools, we examine the selection functions in orbital period, eccentricity and planet mass of Anglo-Australian Planet Search data for three planets with large-scale Monte Carlo like simulations. We find that the detectability of exoplanets declines at high eccentricities. However, we also find that exoplanet detectability is a strong function of epoch-to-epoch data quality, number of observations and period sampling. This strongly suggests that simple parametrizations of the detectability of exoplanets based on ‘whole-of-survey’ metrics may not be accurate. We have derived empirical relationships between the uncertainty estimates for orbital parameters that are derived from least-squares Keplerian fits to our simulations and the true 99 per cent limits for the errors in those parameters, which are larger than equivalent Gaussian limits by the factors of 5–10. We quantify the rate at which false positives are made by our detection criteria, and find that they do not significantly affect our final conclusions. And finally, we find that there is a bias against measuring near-zero eccentricities, which becomes more significant in small, or low signal-to-noise ratio, data sets.
Abstract Disclosing an epilepsy diagnosis to others is complex due to the condition's largely invisible nature and associated stigma. Despite this, little has been documented in terms of what this ...process involves for children living with epilepsy (CWE) and their parents. A systematic review was conducted to examine and synthesize evidence pertaining to: (i) the disclosure practices of CWE and their parents, (ii) enablers and barriers for disclosure, (iii) the impact of disclosure practices, and (iv) the relationship between disclosure management and other variables. The electronic databases PsycINFO, PubMed, MEDLINE, CINAHL, Scopus, and Web of Science were searched systematically. Any empirical, peer-reviewed journal articles with findings reported regarding the self- or proxy-reported disclosure practices of children aged 0–18 years with any type of epilepsy and/or their parents were deemed eligible for inclusion. Two review authors completed all stages of screening, data extraction, and quality assessment independently with two additional review authors resolving any discrepancies. A total of 32 articles were included in the review. Only one dated study examined disclosure as a primary focus; in the remaining studies, disclosure was a subfocus of larger studies or pertinent qualitative themes/subthemes incidentally emerged. The limited evidence suggests that: 1) CWE and parents adopt varying disclosure management strategies — from concealment to voluntary disclosure; 2) disclosure decisions are challenging for CWE and parents; 3) many barriers to disclosure exist (e.g., fear of stigmatization and rejection); 4) only a limited number of factors that enable disclosure are known (e.g., openness by others to engage with and learn about epilepsy); 5) disclosure management is significantly related to a number of variables (e.g., child/maternal perceived stigma and seizure control); and 6) there are varying outcomes for CWE and/or their parents in accordance with the adoption of specific disclosure management strategies (e.g., disclosure resulting in greater acceptance and the receipt of support or evoking anxiety/fear in others; and concealment resulting in misunderstandings, embarrassment, and stigma-coaching), but the evidence remains inconclusive in terms of which disclosure management strategy is optimal. While some preliminary work has been conducted, disclosure of epilepsy is a topic that has been largely neglected to date. This is despite the fact that disclosure is a significant source of concern for CWE and parent populations. Future studies should focus on elucidating the unique contextual factors that inform disclosure decisions in order to develop a theoretical framework that can explain the epilepsy disclosure decision-making process.
Being an informal caregiver (IC) of a cancer patient is often associated with psychological distress. We have recently, in a randomized controlled trial (RCT), demonstrated efficacy of Emotion ...Regulation Therapy for ICs (ERT-C), evidenced as lower levels of psychological distress. Such efficacy demonstration is important, but a crucial step in improving treatments for the IC population is the identification of moderators (i.e., for whom the treatment works) and mediators (i.e., the drivers of the detected effect).
In a sample of 65 psychologically distressed ICs (combining participants who received immediate and delayed treatment in the RCT); we investigated age, gender, and homework completion as moderators of treatment outcome. Proposed mediators were derived from the ERT model and included mindfulness, emotion regulation dysfunction, decentering, and cognitive reappraisal.
The strongest moderation effect was found for homework completion, predicting improvements on psychological distress. Correlational mediation analyses generally supported the ERT model. However, temporal precedence was only established for the association between decentering and worry, where a bidirectional relation was revealed. Homework thus emerged as an important aspect of ERT-C and, albeit a bidirectional relationship, changes in decentering may precede changes in worry. Future trials should ensure the robustness of these results, hone the specificity of process measures, and further investigate the causal timeline of change.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
•GAD is associated with painful physical symptoms.•Psychotherapy can ameliorate both psychological and physical distress.•Changes in anxiety and depression during treatment preceded reductions in ...gastric distress.•Findings highlight utility of using psychotherapy to help physical symptoms in GAD.
Generalized anxiety disorder (GAD) is characterized, in part, by physical symptoms such as muscle tension and gastrointestinal (GI) distress. To date, little research has examined how changes in psychological symptoms associated with GAD may impact physical symptoms. This study investigated if reductions in worry, anxiety, and depression precede changes in muscle tension and GI distress throughout psychotherapy.
Participants with GAD (N = 85) completed 20 weeks of emotion regulation therapy (ERT) in addition to assessments pre, mid, and post treatment. They completed a physical symptom questionnaire, evaluating muscle tension and GI distress. Participants also completed psychological symptoms questionnaires, including the State Trait Anxiety Inventory (STAI-7), Penn State Worry Questionnaire (PSWQ), and Beck Depression Inventory (BDI-II). Control participants (N = 44) completed these measures at baseline.
Participants with GAD had significantly greater muscle tension (p < .001) and GI distress (p < .001) compared to control participants without GAD. Reductions in worry, depression, and trait anxiety did not precede changes in muscle tension (range of effect size (r): .05–.12). Reductions in both depression (p = 0.04) and trait anxiety (p < 0.01) preceded reductions in GI distress. Reductions in worry did not precede reductions in GI distress (p = 0.25).
These data provide preliminary evidence for the temporal effect of reductions in psychological symptoms on reductions in GI distress in GAD, highlighting the potential of psychotherapy to improve physical outcomes.
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