1,679 research outputs found

    The near-infrared companion to HD94660 (=KQ Vel)

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    The Bp star HD94660 is a single-lined spectroscopic binary. Some authors have suggested that the unseen companion of at least 2M_sun may be a compact object. We intend to study this multiple system in detail, especially to learn more about the so-far unseen companion. We have collected and analyzed PIONIER H-band data from the Very Large Telescope Interferometer, TESS visible photometric data, and X-ray observations with Chandra of HD94660. Using PIONIER, we were able to detect the companion to HD94660, which is absent from high quality spectra at visible wavelengths, with a magnitude difference of 1.8 in the H band at a separation of 18.72mas. The TESS light curve shows variations with a period of 2.1d and also flaring. The Chandra spectrum is well described by emission from hot thermal plasma, yet might include a non-thermal component. The X-ray properties are compatible with a magnetically active companion, while some magnetospheric contribution from the primary is also possible. We can rule out that the companion to HD94660 is a compact source. It is also very unlikely that this companion is a single star, as the estimated mass of more than 2M_sun, the magnitude difference of 1.8 in the H band, and its non-detection in visible spectra are difficult to realize in a single object. One alternative could be a pair of late F stars, which would also be responsible for the detected photometric variations. Interferometric observations over the full binary orbit are necessary to determine the real mass of the companion and to add constraints on the overall geometry of the system.Comment: 6 pages, 1 table, 4 figures, accepted for publication in A&

    One-Year Treatment With Exenatide Improves ÎČ-Cell Function, Compared With Insulin Glargine, in Metformin-Treated Type 2 Diabetic Patients: A randomized, controlled trial

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    0.0001). beta-Cell function measures returned to pretreatment values in both groups after a 4-week off-drug period. A1C and body weight rose to pretreatment values 12 weeks after discontinuation of either exenatide or insulin glargine therapy. CONCLUSIONS: Exenatide significantly improves beta-cell function during 1 year of treatment compared with titrated insulin glargine. After cessation of both exenatide and insulin glargine therapy, beta-cell function and glycemic control returned to pretreatment values, suggesting that ongoing treatment is necessary to maintain the beneficial effects of either therap

    Environmental conditions but not nest composition affect reproductive success in an urban bird

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    Adjusting the composition of their nests, breeding birds can influence the environmental conditions that eggs and offspring experience. Birds often use feathers to build nests, presumably due to their insulating properties. The amount of feathers in nests is often associated with increased nestling survival and body condition. However, it is unclear whether these putative beneficial effects of adding feathers to nests are relevant in a wide range of environmental conditions. Here, we combine data on weather conditions and feathers in nests (i.e., nest composition) to investigate their relative contribution to reproductive success in the Eurasian tree sparrow (Passer montanus). Specifically, we investigate whether the effect of weather conditions on breeding success is modulated by the amount of feathers added to the nest. We found a strong negative effect of rainfall on the number of nestlings that successfully fledged per breeding attempt, but this negative effect was not mitigated by the amount of feathers in nests. We also found that the amount of feathers in nests varied along the breeding season, with nests containing more feathers early in the breeding season, when temperatures were lower. Despite considerable variation in nest composition, our results do not suggest an important role of feathers in nests protecting eggs or nestling tree sparrows against fluctuations in environmental conditions

    Quantum critical lines in holographic phases with (un)broken symmetry

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    All possible scaling IR asymptotics in homogeneous, translation invariant holographic phases preserving or breaking a U(1) symmetry in the IR are classified. Scale invariant geometries where the scalar extremizes its effective potential are distinguished from hyperscaling violating geometries where the scalar runs logarithmically. It is shown that the general critical saddle-point solutions are characterized by three critical exponents (Ξ,z,ζ\theta, z, \zeta). Both exact solutions as well as leading behaviors are exhibited. Using them, neutral or charged geometries realizing both fractionalized or cohesive phases are found. The generic global IR picture emerging is that of quantum critical lines, separated by quantum critical points which correspond to the scale invariant solutions with a constant scalar.Comment: v3: 32+29 pages, 2 figures. Matches version published in JHEP. Important addition of an exponent characterizing the IR scaling of the electric potentia

    Efficacy and Safety of Technosphere Inhaled Insulin Compared With Technosphere Powder Placebo in Insulin-Naive Type 2 Diabetes Suboptimally Controlled With Oral Agents

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    OBJECTIVE—This double-blind, placebo-controlled, randomized, multicenter, parallel-group study compared the efficacy, safety, and tolerability of Technosphere insulin with Technosphere powder as placebo in insulin-naive type 2 diabetic patients whose diabetes was suboptimally controlled with oral antidiabetic agents

    Lorentz violation, Gravity, Dissipation and Holography

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    We reconsider Lorentz Violation (LV) at the fundamental level. We show that Lorentz Violation is intimately connected with gravity and that LV couplings in QFT must always be fields in a gravitational sector. Diffeomorphism invariance must be intact and the LV couplings transform as tensors under coordinate/frame changes. Therefore searching for LV is one of the most sensitive ways of looking for new physics, either new interactions or modifications of known ones. Energy dissipation/Cerenkov radiation is shown to be a generic feature of LV in QFT. A general computation is done in strongly coupled theories with gravity duals. It is shown that in scale invariant regimes, the energy dissipation rate depends non-triviallly on two characteristic exponents, the Lifshitz exponent and the hyperscaling violation exponent.Comment: LateX, 51 pages, 9 figures. (v2) References and comments added. Misprints correcte

    Family history is neglected in the work-up of patients with colorectal cancer: a quality assessment using cancer registry data

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    In the diagnostic work-up of hereditary non-polyposis colorectal cancer (HNPCC, Lynch syndrome), high-risk patients can be identified using information from the family history on cancer (‘Amsterdam criteria’ and ‘Bethesda guidelines’). To investigate to what extent the medical specialists apply these criteria to patients with colorectal carcinoma and a suspicion of HNPCC, we collected information on diagnostic work-up of 224 patients of seven hospitals in the region of the Comprehensive Cancer Centre West in Leiden, The Netherlands. These patients were diagnosed with colorectal cancer between 1999 and 2001 and satisfied at least one of the Bethesda guidelines. A complete family history was recorded for 38 of the 244 patients (16%). Patients with a complete family history were more likely to be referred to the Clinical Genetic Centre than those with an incomplete or absent family history (53% vs. 13% and 4%, respectively; P < 0.0001), and more likely to be analyzed for microsatellite instability (MSI), which is a characteristic of HNPCC (34% vs. 6% and 1%, respectively; P < 0.0001). We conclude that the family history is neglected in the majority of patients with colorectal cancer and MSI-analysis is only performed in a small proportion of the patients that meet the guidelines for this analysis
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