With an equilibrium temperature of 1200 K, TrES-1 is one of the coolest hot Jupiters observed by Spitzer. It was also the first planet discovered by any transit survey and one of the first exoplanets ...from which thermal emission was directly observed. We analyzed all Spitzer eclipse and transit data for TrES-1 and obtained its eclipse depths and brightness temperatures in the 3.6 mu m (0.083% + or - 0.024%, 1270 + or - 110 K), 4.5 mu m (0.094% + or - 0.024%, 1126 + or - 90 K), 5.8 mu m (0.162% + or - 0.042%, 1205 + or - 130 K), 8.0 mu m (0.213% + or - 0.042%, 1190 + or - 130 K), and 16 mu m (0.33% + or - 0.12%, 1270 + or - 310 K) bands. The eclipse depths can be explained, within 1sigma errors, by a standard atmospheric model with solar abundance composition in chemical equilibrium, with or without a thermal inversion. The combined analysis of the transit, eclipse, and radial-velocity ephemerides gives an eccentricity of e = 0.033 super(+0.015) sub(-0.031) , consistent with a circular orbit. Since TrES-1's eclipses have low signal-to-noise ratios, we implemented optimal photometry and differential-evolutionMarkov ChainMonte Carlo (MCMC) algorithms in our Photometry for Orbits, Eclipses, and Transits pipeline. Benefits include higher photometric precision and~10 times faster MCMC convergence, with better exploration of the phase space and no manual parameter tuning.
Decisions made during stand regeneration that affect subsequent levels of competing vegetation and residual biomass can have important short-term consequences for early stand growth, and may affect ...long-term site productivity. Competing vegetation clearly affects the availability of site resources such as soil moisture and nutrients. Harvest residues can also impact the availability of site resources. We examined second- and third-year seedling performance of a Douglas-fir (
Pseudotsuga menziesii (Mirb.) Franco) plantation with different vegetation control and biomass retention treatments on a highly productive site in the coast range of Washington. Treatments included a bole-only harvest without vegetation control (BO
−
VC), a bole-only harvest with complete vegetation control (BO
+
VC), and a total tree harvest with complete vegetation control that also included removal of all coarse woody debris and harvest residues (TTP
+
VC). The objectives of the study were to determine if vegetation control and residue retention treatments affected soil moisture, soil temperature, and apparent nitrogen (N) availability, and whether these differences in site resources were correlated with seedling size and growth. In both the second and third growing seasons, volumetric soil moisture at 0–20
cm depth was lowest on plots that did not receive vegetation control (BO
−
VC). Seedlings on these plots also had the lowest diameter and volume growth. In year 2, which was fairly moist, volume growth on TTP
+
VC plots was slightly higher than on BO
+
VC plots. TTP
+
VC plots did have lower soil moisture, but soil temperatures were slightly warmer. In year 3, a drier year, growth was greatest on BO
+
VC plots, which had consistently higher soil moisture levels. Apparent N availability in year 3 also varied with vegetation control. Douglas-fir foliar N concentrations averaged 2.3% on the plots where competing vegetation was eliminated, compared to 1.8% on plots where competing vegetation was not controlled. Douglas-fir foliar N concentrations did not differ between residue retention treatments, although N concentrations of competing vegetation were higher where residual biomass was retained. Higher apparent N availability was correlated with greater seedling growth. Based on results from years 2 and 3, it appears that soil moisture, particularly late in the growing season, had the greatest effect on seedling growth in both years. Available N may also have played a role, although the effects of N cannot be completely separated from those of soil moisture. When soil moisture is adequate, it appears that available N and soil temperature exert greater influence on growth. Vegetation control and residue retention can influence all three of these factors. The relative importance of each factor may depend on the year-to-year variation in environmental conditions.
We investigate the current-phase relations of Al/InAs-quantum well planar Josephson junctions fabricated using nanowire shadowing technique. Based on several experiments, we conclude that the ...junctions exhibit an unusually large second-order Josephson harmonic, the
\sin(2\varphi)
sin
(
2
φ
)
term. First, superconducting quantum interference devices (dc-SQUIDs) show half-periodic oscillations, tunable by gate voltages as well as magnetic flux. Second, Josephson junction devices exhibit kinks near half-flux quantum in supercurrent diffraction patterns. Third, half-integer Shapiro steps are present in the junctions. Similar phenomena are observed in Sn/InAs quantum well devices. We perform data fitting to a numerical model with a two-component current phase relation. Analysis including a loop inductance suggests that the sign of the second harmonic term is negative. The microscopic origins of the observed effect remain to be understood. We consider alternative explanations which can account for some but not all of the evidence.
Secondary Eclipses of HAT-P-13b Hardy, Ryan A.; Harrington, Joseph; Hardin, Matthew R. ...
The Astrophysical journal,
02/2017, Letnik:
836, Številka:
1
Journal Article
Recenzirano
Odprti dostop
We present Spitzer secondary-eclipse observations of the hot Jupiter HAT-P-13 b in the 3.6 and 4.5 m bands. HAT-P-13 b inhabits a two-planet system with a configuration that enables constraints on ...the planet's second Love number, , from precise eccentricity measurements, which in turn constrains models of the planet's interior structure. We exploit the direct measurements of from our secondary-eclipse data and combine them with previously published radial velocity data to generate a refined model of the planet's orbit and thus an improved estimate on the possible interval for . We report eclipse phases of and and corresponding estimates of and . Under the assumptions of previous work, our estimate of of 0.81 0.10 is consistent with the lower extremes of possible core masses found by previous models, including models with no solid core. This anomalous result challenges both interior models and the dynamical assumptions that enable them, including the essential assumption of apsidal alignment. We also report eclipse depths of 0.081% 0.008% in the 3.6 m channel and 0.088% 0.028% in the 4.5 m channel. These photometric results are non-uniquely consistent with solar-abundance composition without any thermal inversion.
The growth in terahertz frequency applications utilising the quantum cascade laser is hampered by a lack of targeted power delivery solutions over large distances (>100 mm). Here we demonstrate the ...efficient coupling of double-metal quantum cascade lasers into flexible polystyrene lined hollow metallic waveguides via the use of a hollow copper waveguide integrated into the laser mounting block. Our approach exhibits low divergence, Gaussian-like emission, which is robust to misalignment error, at distances > 550 mm, with a coupling efficiency from the hollow copper waveguide into the flexible waveguide > 90%. We also demonstrate the ability to nitrogen purge the flexible waveguide, increasing the power transmission by up to 20% at 2.85 THz, which paves the way for future fibre based terahertz sensing and spectroscopy applications.
Geodetic observations in the oceans are important for understanding plate tectonics, earthquake cycles and volcanic processes. One approach to seafloor geodesy is the use of seafloor pressure gauges ...to sense vertical changes in the elevation of the seafloor after correcting for variations in the weight of the overlying oceans and atmosphere. A challenge of using pressure gauges is the tendency for the sensors to drift. The A-0-A method is a new approach for correcting drift. A valve is used to periodically switch, for a short time, the measured pressure from the external ocean to the inside of the instrument housing at atmospheric pressure. The internal pressure reading is compared to an accurate barometer to measure the drift which is assumed to be the same at low and high pressures. We describe a 30-months test of the A-0-A method at 900 m depth on the MARS cabled observatory in Monterey Bay using an instrument that includes two A-0-A calibrated pressure gauges and a three-component accelerometer. Prior to the calibrations, the two pressure sensors drift by 6 and 2 hPa, respectively. After the calibrations, the offsets of the corrected pressure sensors are consistent with each other to within 0.2 hPa. The drift corrected detided external pressure measurements show a 0.5 hPa/yr trend of increasing pressures during the experiment. The measurements are corrected for instrument subsidence based on the changes in tilt measured by the accelerometer, but the trend may include a component of subsidence that did not affect tilt. However, the observed trend of increasing pressure, closely matches that calculated from satellite altimetry and repeat conductivity, temperature and depth casts at a nearby location, and increasing pressures are consistent with the trend expected for the El Niño Southern Oscillation. We infer that the A-0-A drift corrections are accurate to better than one part in 10
5
per year. Additional long-term tests and comparisons with oceanographic observations and other methods for drift correction will be required to understand if the accuracy the A-0-A drift corrections matches the observed one part in 10
6
per year consistency between the two pressure sensors.
Background Inhibition of the P2Y12 ADP-receptor with oral antiplatelet agents given to patients undergoing primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction ...(STEMI) is associated with improved outcomes, but this strategy is limited by the time required for maximal antiplatelet effect after administration. We examined the safety and tolerability of a novel, direct-acting, reversible, intravenous P2Y12 ADP-receptor antagonist, elinogrel, versus placebo when administered to STEMI patients before primary PCI. Methods The ERASE MI trial was a pilot, phase IIA, randomized, double-blind, placebo-controlled, dose-escalation study designed to evaluate the safety and tolerability of escalating doses (10, 20, 40, and 60 mg) of elinogrel administered as a single intravenous bolus before the start of the diagnostic angiogram preceding primary PCI. Patients were randomly assigned in a 1:1 manner to either elinogrel or placebo within each dosing group; and all patients received a 600-mg clopidogrel loading dose, followed by a second 300-mg clopidogrel loading dose 4 hours after PCI. The major outcome, in-hospital bleeding, was assessed with the Thrombolysis in Myocardial Infarction and Global Strategies to Open Occluded Coronary Arteries bleeding scales. Pre-PCI corrected Thrombolysis in Myocardial Infarction frame count and ST-segment resolution were also evaluated. Results Seventy patients were randomized in the dose-escalation study, but the dose-confirmation phase was not started because the trial was prematurely terminated for administrative reasons. The incidence of bleeding events was infrequent and appeared to be similar in patients treated with all doses of elinogrel versus placebo. No differences in serious adverse events, laboratory values, corrected Thrombolysis in Myocardial Infarction frame count, or ST resolution were demonstrated between elinogrel and placebo. Conclusions With the limitations of a small study sample size, this pilot study provided preliminary data on the feasibility and tolerability of escalating doses of a direct-acting, reversible, intravenous P2Y12 ADP-receptor antagonist, elinogrel, as an adjunctive therapy for primary PCI for STEMI.
Platelets play a crucial role in the ischemic complications of percutaneous coronary procedures. The recent availability of c7E3 Fab (abciximab; ReoPro), a chimeric monoclonal antibody Fab fragment ...directed against the platelet glycoprotein IIb/IIIa receptor, has reduced abrupt closure and other adverse clinical events and lessened the need for revascularization procedures. As experience accrues, rare cases of acute profound thrombocytopenia have been revealed.
From November 1991 to July 1996, patients at Duke University Medical Center who underwent percutaneous coronary revascularization and received their first exposure to c7E3 Fab were evaluated for the development of acute profound thrombocytopenia, defined as a platelet count < 20 x 10(9)/L occurring within 24 hours of initial treatment. Four patients (0.5%) developed acute profound thrombocytopenia within 11 to 21 hours of receiving the c7E3 Fab bolus. Nadir platelet counts ranged from 1 to 16 x 10(9)/L and occurred within 11 to 26 hours. No patient developed a significant hemorrhagic complication, and each patient's platelet count responded to platelet transfusion. Platelet counts remained depressed for at least 3 days but returned to baseline within 2 weeks.
Acute profound thrombocytopenia can occur after c7E3 Fab administration. Its development was not predictable, and it requires consideration in every patient treated. A platelet count 2 to 4 hours after the bolus would likely have detected these four cases. When indicated, platelet transfusion will raise the platelet count to safer levels without adverse effects. The differential diagnosis (including heparin-induced thrombocytopenia), a plan for management, and postulates as to the mechanism are discussed.
Summary Background Cangrelor is a potent, rapid-acting, reversible intravenous platelet inhibitor that was tested for percutaneous coronary intervention (PCI) in three large, double-blind, randomised ...trials. We did a pooled analysis of data from three trials that assessed the effectiveness of cangrelor against either clopidogrel or placebo in PCI. Methods This prespecified, pooled analysis of patient-level data from three trials (CHAMPION-PCI, CHAMPION-PLATFORM, and CHAMPION-PHOENIX) compared cangrelor with control (clopidogrel or placebo) for prevention of thrombotic complications during and after PCI. Trial participants were patients undergoing PCI for ST-elevation myocardial infarction (11·6%), non-ST-elevation acute coronary syndromes (57·4%), and stable coronary artery disease (31·0%). Efficacy was assessed in the modified intention-to-treat population of 24 910 patients, with a prespecified primary efficacy composite of death, myocardial infarction, ischaemia-driven revascularisation, or stent thrombosis at 48 h. The primary safety outcome was non-coronary artery bypass graft-related GUSTO (Global Use of Strategies to Open Occluded Coronary Arteries) severe or life-threatening bleeding at 48 h. Findings Cangrelor reduced the odds of the primary outcome by 19% (3·8% for cangrelor vs 4·7% for control; odds ratio OR 0·81, 95% CI 0·71–0·91, p=0·0007), and stent thrombosis by 41% (0·5% vs 0·8%, OR 0·59, 95% CI 0·43–0·80, p=0·0008). Cangrelor reduced the odds of the secondary triple composite (all-cause death, myocardial infarction, or ischaemia-driven revascularisation at 48 h) by 19% (3·6% vs 4·4%, OR 0·81, 95% CI 0·71–0·92, p=0·0014). Efficacy outcomes were consistent across the trials and main patient subsets. These benefits were maintained at 30 days. There was no difference in the primary safety outcome (0·2% in both groups), in GUSTO moderate bleeding (0·6% vs 0·4%), or in transfusion (0·7% vs 0·6%), but cangrelor increased GUSTO mild bleeding (16·8% vs 13·0%, p<0·0001). Interpretation Compared with control (clopidogrel or placebo), cangrelor reduced PCI periprocedural thrombotic complications, at the expense of increased bleeding. Funding The Medicines Company.
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