High serum immunoglobulin g and m levels predict freedom from adverse cardiovascular events in hypertension: a nested case-control substudy of the Anglo-Scandinavian cardiac outcomes trial

Aims: We aimed to determine whether the levels of total serum IgM and IgG, together with specific antibodies against malondialdehyde-conjugated low-density lipoprotein (MDA-LDL), can improve cardiovascular risk discrimination. Methods and Results: The Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) randomized 9098 patients in the UK and Ireland into the Blood Pressure-Lowering Arm. 485 patients that had cardiovascular (CV) events over 5.5 years were age and sex matched with 1367 controls. Higher baseline total serum IgG, and to a lesser extent IgM, were associated with decreased risk of CV events (IgG odds ratio (OR) per one standard deviation (SD) 0.80 [95% confidence interval, CI 0.72,0.89], p < 0.0001; IgM 0.83[0.75,0.93], p = 0.001), and particularly events due to coronary heart disease (CHD) (IgG OR 0.66 (0.57,0.76); p < 0.0001, IgM OR 0.81 (0.71,0.93); p = 0.002). The association persisted after adjustment for a basic model with variables in the Framingham Risk Score (FRS) as well as following inclusion of C-reactive protein (CRP) and N-terminal pro-B-type natriuretic peptide (NtProBNP). IgG and IgM antibodies against MDA-LDL were also associated with CV events but their significance was lost following adjustment for total serum IgG and IgM respectively. The area under the receiver operator curve for CV events was improved from the basic risk model when adding in total serum IgG, and there was improvement in continuous and categorical net reclassification (17.6% and 7.5% respectively) as well as in the integrated discrimination index. Conclusion: High total serum IgG levels are an independent predictor of freedom from adverse cardiovascular events, particularly those attributed to CHD, in patients with hypertension

The Transit Light Curve Project. IX. Evidence for a Smaller Radius of the Exoplanet XO-3b

We present photometry of 13 transits of XO-3b, a massive transiting planet on an eccentric orbit. Previous data led to two inconsistent estimates of the planetary radius. Our data strongly favor the smaller radius, with increased precision: R_p = 1.217 +/- 0.073 R_Jup. A conflict remains between the mean stellar density determined from the light curve, and the stellar surface gravity determined from the shapes of spectral lines. We argue the light curve should take precedence, and revise the system parameters accordingly. The planetary radius is about 1 sigma larger than the theoretical radius for a hydrogen-helium planet of the given mass and insolation. To help in planning future observations, we provide refined transit and occultation ephemerides.Comment: To appear in ApJ [22 pages

The XO Planetary Survey Project - Astrophysical False Positives

Searches for planetary transits find many astrophysical false positives as a by-product. There are four main types analyzed in the literature: a grazing-incidence eclipsing binary star, an eclipsing binary star with a small radius companion star, a blend of one or more stars with an unrelated eclipsing binary star, and a physical triple star system. We present a list of 69 astrophysical false positives that had been identified as candidates of transiting planets of the on-going XO survey. This list may be useful in order to avoid redundant observation and characterization of these particular candidates independently identified by other wide-field searches for transiting planets. The list may be useful for those modeling the yield of the XO survey and surveys similar to it. Subsequent observations of some of the listed stars may improve mass-radius relations, especially for low-mass stars. From the candidates exhibiting eclipses, we report three new spectroscopic double-line binaries and give mass function estimations for 15 single lined spectroscopic binaries.Comment: 13 pages, 4 figures, accepted to ApJ

Thermal Emission and Tidal Heating of the Heavy and Eccentric Planet XO-3b

We determined the flux ratios of the heavy and eccentric planet XO-3b to its parent star in the four IRAC bands of the Spitzer Space Telescope: 0.101% +- 0.004% at 3.6 micron; 0.143% +- 0.006% at 4.5 micron; 0.134% +- 0.049% at 5.8 micron and 0.150% +- 0.036% at 8.0 micron. The flux ratios are within [-2.2,0.3, -0.8, -1.7]-sigma of the model of XO-3b with a thermally inverted stratosphere in the 3.6 micron, 4.5 micron, 5.8 micron and 8.0 micron channels, respectively. XO-3b has a high illumination from its parent star (Fp ~(1.9 - 4.2) x 10^9 ergs cm^-2 s^-1) and is thus expected to have a thermal inversion, which we indeed observe. When combined with existing data for other planets, the correlation between the presence of an atmospheric temperature inversion and the substellar flux is insufficient to explain why some high insolation planets like TrES-3 do not have stratospheric inversions and some low insolation planets like XO-1b do have inversions. Secondary factors such as sulfur chemistry, atmospheric metallicity, amounts of macroscopic mixing in the stratosphere or even dynamical weather effects likely play a role. Using the secondary eclipse timing centroids we determined the orbital eccentricity of XO-3b as e = 0.277 +- 0.009. The model radius-age trajectories for XO-3b imply that at least some amount of tidal-heating is required to inflate the radius of XO-3b, and the tidal heating parameter of the planet is constrained to Qp < 10^6 .Comment: Accepted for publications in The Astrophysical Journa

XO-3b: A Massive Planet in an Eccentric Orbit Transiting an F5V Star

We report the discovery of a massive (Mpsini = 13.02 +/- 0.64 Mjup; total mass 13.25 +/- 0.64 Mjup), large (1.95 +/- 0.16 Rjup) planet in a transiting, eccentric orbit (e = 0.260 +/- 0.017) around a 10th magnitude F5V star in the constellation Camelopardalis. We designate the planet XO-3b, and the star XO-3, also known as GSC 03727-01064. The orbital period of XO-3b is 3.1915426 +/- 0.00014 days. XO-3 lacks a trigonometric distance; we estimate its distance to be 260 +/- 23 pc. The radius of XO-3 is 2.13 +/- 0.21 Rsun, its mass is 1.41 +/- 0.08 Msun, its vsini = 18.54 +/- 0.17 km/s, and its metallicity is [Fe/H] = -0.177 +/- 0.027. This system is unusual for a number of reasons. XO-3b is one of the most massive planets discovered around any star for which the orbital period is less than 10 days. The mass is near the deuterium burning limit of 13 Mjup, which is a proposed boundary between planets and brown dwarfs. Although Burrows et al. (2001) propose that formation in a disk or formation in the interstellar medium in a manner similar to stars is a more logical way to differentiate planets and brown dwarfs, our current observations are not adequate to address this distinction. XO-3b is also unusual in that its eccentricity is large given its relatively short orbital period. Both the planetary radius and the inclination are functions of the spectroscopically determined stellar radius. Analysis of the transit light curve of XO-3b suggests that the spectroscopically derived parameters may be over estimated. Though relatively noisy, the light curves favor a smaller radius in order to better match the steepness of the ingress and egress. The light curve fits imply a planetary radius of 1.25 +/- 0.15 Rjup, which would correspond to a mass of 12.03 +/- 0.46 Mjup.Comment: 26 pages, 10 figures. Accepted by ApJ. Current version has several small corrections as a result of a bug in the fitting softwar

Do early warning indicators consistently predict nonlinear change in long-term ecological data?

1. Anthropogenic pressures, including climate change, are causing nonlinear changes in ecosystems globally. The development of reliable early warning indicators (EWIs) to predict these changes is vital for the adaptive management of ecosystems and the protection of biodiversity, natural capital and ecosystem services. Increased variance and autocorrelation are potential early warning indicators and can be readily estimated from ecological time series. Here, we undertook a comprehensive test of the consistency between early warning indicators and nonlinear abundance change across species, trophic levels and ecosystem types. 2. We tested whether long-term abundance time series of 55 taxa (126 data sets) across multiple trophic levels in marine and freshwater ecosystems showed (i) significant nonlinear change in abundance ‘turning points’ and (ii) significant increases in variance and autocorrelation (‘early warning indicators’). For each data set, we then quantified the prevalence of three cases: true positives (early warning indicators and associated turning point), false negatives (turning point but no associated early warning indicators) and false positives (early warning indicators but no turning point). 3. True positives were rare, representing only 9% (16 of 170) of cases using variance, and 13% (19 of 152) of cases using autocorrelation. False positives were more prevalent than false negatives (53% vs. 38% for variance; 47% vs. 40% for autocorrelation). False results were found in every decade and across all trophic levels and ecosystems. 4. Time series that contained true positives were uncommon (8% for variance; 6% for autocorrelation), with all but one time series also containing false classifications. Coherence between the types of early warning indicators was generally low with 43% of time series categorized differently based on variance compared to autocorrelation. 5. Synthesis and applications. Conservation management requires effective early warnings of ecosystem change using readily available data, and variance and autocorrelation in abundance data have been suggested as candidates. However, our study shows that they consistently fail to predict nonlinear change. For early warning indicators to be effective tools for preventative management of ecosystem change, we recommend that multivariate approaches of a suite of potential indicators are adopted, incorporating analyses of anthropogenic drivers and process-based understanding

Spatio-temporal variation in the zooplankton prey of lesser sandeels : species and community trait patterns from the continuous plankton recorder

The phenology, distribution and size composition of plankton communities are changing rapidly in response to warming. This may lead to shifts in the prey fields of planktivorous fish, which play a key role in transferring energy up marine food chains. Here, we use 60+ years of Continuous Plankton Recorder data to explore temporal trends in key taxa and community traits in the prey field of planktivorous lesser sandeels (Ammodytes marinus) in the North Sea, the Faroes and southern Iceland. We found marked spatial variation in the prey field, with Calanus copepods generally being a key component much more common in the northern part of the study area, but not further south. In the western North Sea, the estimated amount of available energy in the prey field has decreased by more than 50% since the 1960s. This decrease was accompanied by declining abundances of small copepods, and shifts in the timing of peak annual prey abundances out of the sandeel foraging season. Further, the estimated average prey community body prey size has increased in several of the locations considered. Overall, our results point to the importance of considering the full prey field of planktivores regional studies of prey fields, rather than and caution against inferring ecological consequences based only on large-scale trends in key taxa or mean community traits