2,650 research outputs found
First Light of Engineered Diffusers at the Nordic Optical Telescope Reveal Time Variability in the Optical Eclipse Depth of WASP-12b
We present the characterization of two engineered diffusers mounted on the
2.5 meter Nordic Optical Telescope, located at Roque de Los Muchachos, Spain.
To assess the reliability and the efficiency of the diffusers, we carried out
several test observations of two photometric standard stars, along with
observations of one primary transit observation of TrES-3b in the red (R-band),
one of CoRoT-1b in the blue (B-band), and three secondary eclipses of WASP-12b
in V-band. The achieved photometric precision is in all cases within the
sub-millimagnitude level for exposures between 25 and 180 seconds. Along a
detailed analysis of the functionality of the diffusers, we add a new transit
depth measurement in the blue (B-band) to the already observed transmission
spectrum of CoRoT-1b, disfavouring a Rayleigh slope. We also report variability
of the eclipse depth of WASP-12b in the V-band. For the WASP-12b secondary
eclipses, we observe a secondary-depth deviation of about 5-sigma, and a
difference of 6-sigma and 2.5-sigma when compared to the values reported by
other authors in similar wavelength range determined from Hubble Space
Telescope data. We further speculate about the potential physical processes or
causes responsible for this observed variabilityComment: 11 pages, 9 figure
Dapagliflozin reduces albuminuria over 2 years in patients with type 2 diabetes mellitus and renal impairment
Prediction of the effect of dapagliflozin on kidney and heart failure outcomes based on short-term changes in multiple risk markers
BACKGROUND: Besides improving glucose control, sodium-glucose co-transporter 2 inhibition with dapagliflozin reduces blood pressure, body weight and urinary albumin:creatinine ratio (UACR) in patients with type 2 diabetes (T2DM). The parameter response efficacy (PRE) score was developed to predict how short-term drug effects on cardiovascular risk markers translate into long-term changes in clinical outcomes. We applied the PRE score to clinical trials of dapagliflozin to model the effect of the drug on kidney and heart failure (HF) outcomes in patients with T2DM and impaired kidney function. METHODS: The relationships between multiple risk markers and long-term outcome were determined in a background population of patients with T2DM with a multivariable Cox model. These relationships were then applied to short-term changes in risk markers observed in a pooled database of dapagliflozin trials (nâ=â7) that recruited patients with albuminuria to predict the drug-induced changes to kidney and HF outcomes. RESULTS: A total of 132 and 350 patients had UACRâ>200âmg/g and >30âmg/g at baseline, respectively, and were selected for analysis. The PRE score predicted a risk change for kidney events of -40.8% [95% confidence interval (CI) -51.7 to -29.4) and -40.4% (95% CI -48.4 to -31.1) with dapagliflozin 10âmg compared with placebo for the UACRâ>200âmg/g and >30âmg/g subgroups. The predicted change in risk for HF events was -27.3% (95% CI -47.7 to -5.1) and -21.2% (95% CI -35.0 to -7.8), respectively. Simulation analyses showed that even with a smaller albuminuria-lowering effect of dapagliflozin (10% instead of the observed 35% in both groups), the estimated kidney risk reduction was still 26.5 and 26.8%, respectively. CONCLUSIONS: The PRE score predicted clinically meaningful reductions in kidney and HF events associated with dapagliflozin therapy in patients with diabetic kidney disease. These results support a large long-term outcome trial in this population to confirm the benefits of the drug on these endpoints
Immune gene profiles in Atlantic salmon (salmo salar L.) post-smolts infected with SAV3 by bath-challenge show a delayed response and lower levels of gene transcription compared to injected fish
Acknowledgements This research was funded by the Research Council of Norway, Research grant # 224885/E40. The following people are thanked for their expert technical assistance and help during sampling; Ann Catherine BĂ„rdsgjĂŠre Einen, Stig MĂŠhle, Ingrid Fiksdal and Miriam Castillo FurnĂ©. Thanks also to Ivar Helge Matre at Matre Research Station, IMR for the production of fish and Joachim NordbĂž for fish husbandry and help with sampling. Ăystein Evensen, Norwegian University of Life Sciences, is acknowledged for providing the SAV3 isolate.Peer reviewedPostprin
Atlantic salmon adapted to seawater for 9 weeks develop a robust immune response to salmonid alphavirus upon bath challenge
This research was funded by the Research Council of Norway. Research grant # 224885/E40. The following people are thanked for their expert technical assistance and help during sampling and analysis; Ann Catherine Einen BĂ„rdsgjĂŠre, Stig MĂŠhle, Ingrid Fiksdal and Miriam Castillo FurnĂ©. Thanks also to Ivar Helge Matre (Matre Research Station, Institute for Marine Research) for production of fish and Joachim NordbĂž for fish husbandry and help with sampling. Kai Ove Skaftnesmoe is thanked for the preparation of Fig. 6. Ăystein Evensen, Norwegian University of Life Sciences, is acknowledged for providing the SAV3 isolate.Peer reviewedPostprin
CARM1 and BAF155: an example of how chromatin remodeling factors can be relocalized and contribute to cancer
Correction of anemia by dapagliflozin in patients with type 2 diabetes
Aims: Anemia is common in type 2 diabetes (T2D), particularly in patients with kidney impairment, and often goes unrecognized. Dapagliflozin treatment increases hemoglobin and serum erythropoietin levels. We investigated the effect of dapagliflozin 10-mg/day on hemoglobin in T2D patients with and without anemia. Methods: Data from 5325 patients from 14 placebo-controlled, dapagliflozin-treatment studies of at least 24-weeks duration were pooled. Dapagliflozin's effects (vs. placebo) on hemoglobin, serum albumin, estimated glomerular filtration rate (eGFR), systolic blood pressure, body weight, and safety in patients with and without anemia were evaluated. Results: At baseline, 13% of all T2D patients and 28% of those with chronic kidney disease (eGFR Conclusions: Treatment with dapagliflozin can correct and prevent anemia in T2D patients. A gradual increase in hemoglobin beyond week 4 may indicate an erythropoiesis-stimulating effect of sodium-glucose cotransporter 2 inhibition. (c) 2020 Published by Elsevier Inc
Solar Contamination in Extreme-precision Radial-velocity Measurements: Deleterious Effects and Prospects for Mitigation
Solar contamination, due to moonlight and atmospheric scattering of sunlight, can cause systematic errors in stellar radial velocity (RV) measurements that significantly detract from the ~10 cm sâ1 sensitivity required for the detection and characterization of terrestrial exoplanets in or near habitable zones of Sun-like stars. The addition of low-level spectral contamination at variable effective velocity offsets introduces systematic noise when measuring velocities using classical mask-based or template-based cross-correlation techniques. Here we present simulations estimating the range of RV measurement error induced by uncorrected scattered sunlight contamination. We explore potential correction techniques, using both simultaneous spectrometer sky fibers and broadband imaging via coherent fiber imaging bundles, that could reliably reduce this source of error to below the photon-noise limit of typical stellar observations. We discuss the limitations of these simulations, the underlying assumptions, and mitigation mechanisms. We also present and discuss the components designed and built into the NEID (NN-EXPLORE Exoplanet Investigations with Doppler spectroscopy) precision RV instrument for the WIYN 3.5 m telescope, to serve as an ongoing resource for the community to explore and evaluate correction techniques. We emphasize that while "bright time" has been traditionally adequate for RV science, the goal of 10 cm sâ1 precision on the most interesting exoplanetary systems may necessitate access to darker skies for these next-generation instruments
Reduction in albuminuria with dapagliflozin cannot be predicted by baseline clinical characteristics or changes in most other risk markers
The sodium glucose co-transporter-2 inhibitor dapagliflozin has been shown to decrease urinary albumin-to-creatinine ratio (UACR). This effect, however, varies among individual patients. In this study, we assessed the baseline characteristics and concurrent changes in other cardiovascular risk markers that might be associated with UACR response to dapagliflozin. A pooled analysis of 11 phase 3 randomized, controlled clinical trials was performed. UACR change from baseline after 24 weeks treatment with dapagliflozin 10 mg/d in 531 patients with type 2 diabetes and UACR â„30 mg/g at baseline was determined. UACR response was defined as >30% reduction from baseline at 24 weeks, whereas UACR non-response was defined as â€30% reduction at 24 weeks. A total of 288 (54%) patients were classified as responders and 243 (46%) as non-responders. At 24 weeks, the UACR-adjusted mean change from baseline was -71.2% and 25.9% in responders and non-responders, respectively. Baseline characteristics were similar between both groups. Changes in HbA1c and body weight were comparable across groups. Responders showed a numerically larger reduction in estimated glomerular filtration rate and systolic blood pressure versus non-responders. UACR reduction to dapagliflozin is an individual characteristic that cannot be predicted by baseline clinical features or changes in metabolic variables. Whether UACR response would improve long-term renal and cardiovascular outcomes remains to be determined
Persistent starspot signals on M dwarfs: multi-wavelength Doppler observations with the Habitable-zone Planet Finder and Keck/HIRES
Young, rapidly-rotating M dwarfs exhibit prominent starspots, which create
quasiperiodic signals in their photometric and Doppler spectroscopic
measurements. The periodic Doppler signals can mimic radial velocity (RV)
changes expected from orbiting exoplanets. Exoplanets can be distinguished from
activity-induced false positives by the chromaticity and long-term incoherence
of starspot signals, but these qualities are poorly constrained for
fully-convective M stars. Coherent photometric starspot signals on M dwarfs may
persist for hundreds of rotations, and the wavelength dependence of starspot RV
signals may not be consistent between stars due to differences in their
magnetic fields and active regions. We obtained precise multi-wavelength RVs of
four rapidly-rotating M dwarfs (AD Leo, G 227-22, GJ 1245B, GJ 3959) using the
near-infrared (NIR) Habitable-zone Planet Finder, and the optical Keck/HIRES
spectrometer. Our RVs are complemented by photometry from Kepler, TESS, and the
Las Cumbres Observatory (LCO) network of telescopes. We found that all four
stars exhibit large spot-induced Doppler signals at their rotation periods, and
investigated the longevity and optical-to-NIR chromaticity for these signals.
The phase curves remain coherent much longer than is typical for Sunlike stars.
Their chromaticity varies, and one star (GJ 3959) exhibits optical and NIR RV
modulation consistent in both phase and amplitude. In general, though, we find
that the NIR amplitudes are lower than their optical counterparts. We conclude
that starspot modulation for rapidly-rotating M stars frequently remains
coherent for hundreds of stellar rotations, and gives rise to Doppler signals
that, due to this coherence, may be mistaken for exoplanets.Comment: Accepted for publication in the Astrophysical Journa
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