Marital Histories and Economic Well-Being

Compared to unmarried individuals married individuals report greater average wealth. A restricted focus on current marital status risks misrepresenting the effects of marriage on wealth, as an increasing proportion of older adults have been divorced and remarried, having lived through the dramatic upheavals in family structure from the 1960s through the 1980s. To shed light on the associations between a lifetime of marriage events and wealth near retirement, we used panel data from the Health and Retirement Study and developed categories of marital experiences that acknowledged current status, type, number and date of past marital disruptions and total duration of time spent married across the lifespan. We found that the route individuals took to get to their current marital status were important predictors of wealth levels near retirement and were different for males and females. Observable differences in lifetime earnings, mortality risk, risk aversion, other characteristics such as education and number of children, explained much of the wealth difference between married and remarried individuals however neither observable characteristics nor sources of other wealth from pensions and Social Security were enough to explain the large differences in wealth accumulation between single and married women and individuals experiencing more than one marital disruption. Given the higher divorce rate, prevalence of multiple divorces and earlier age of divorce of the Baby Boomer cohort compared to earlier cohorts, an understanding of how marriage disruptions over the lifecycle impact savings is increasingly important for understanding the economic security of retirees.

Mann and gender in Old English prose : a pilot study

It has long been known that OE mann was used in gender-neutral as well as gender-specific contexts. Because of the enormous volume of its attestations in Old English prose, the more precise usage patterns of mann remain, however, largely uncharted, and existing lexicographical tools provide only a basic picture. This article aims to present a preliminary study of the various uses of mann as attested in Old English prose, particularly in its surprisingly consistent use by an individual author, namely that of the ninth-century Old English Martyrology. Patterns emerging from this text are then tested against other prose material. Particular attention is paid to gender-specific usage, examples of which are shown to be exceptional for a word which largely occurs in gender-neutral contexts.Peer reviewe

First images of a possible CO(+)-tail of comet P/Schwassmann-Wachmann 1 observed against the dust coma background

Comet P/Schwassmann-Wachmann 1 was observed with the 2m-Ritchey-Cretien Telescope of the Bulgarian National Observatory, Rozhen, Bulgaria, using the CCD-camera and focal reducer of the Max-Planck-Institute for Aeronomy. Images were taken in a red continuum window and in the 2-0 A(exp 2)Pi - X(exp 2)Sigma(+) band of CO(+) located in the blue part of the spectrum. The red images reveal an extended dust coma. From a comparison of the red and blue images a dust reddening of 13.2 percent per 1000 A is derived. At 642 nm the magnitude of the comet with a square diaphragm of 4.5 arcsec is 16.6. The blue images, taken in the CO(+) band, show a significantly different brightness distribution which is interpreted as presence of a CO(+) coma and tail superimposed on the continuum. A column density of several 10(exp 10) CO(+) molecules cm(exp -2) is derived. The tail thickness of 10(exp 5) km is unexpectedly small. We estimate the CO(+) production rate to about 6 x 10(exp 26) CO(+) particles s(exp -1). This value does not support the idea that the outbursts of this comet are caused by crystallization of amorphous water ice

Champagne Seas—Foretelling the Ocean’s Future?

Imagine you are an ocean researcher and you want to study the ecological impacts of ocean acidification. You know from studies carried out under controlled laboratory conditions that lowered pH can impact the physiology, growth, and development of certain organisms. What you want to know next is how these changes in individual species translate into the direct and indirect ecological changes that occur in the open ocean. Here we summarize the results from a new approach to understanding the ecological implications of ocean acidification: observational studies and IN SITU experimentation at ocean sites with low pH and high CO2

Front- vs. back-illuminated CCD cameras for photometric surveys: a noise budget analysis

Exoplanetary transit and stellar oscillation surveys require a very high precision photometry. The instrumental noise has therefore to be minimized. First, we perform a semi-analytical model of different noise sources. We show that the noise due the CCD electrodes can be overcome using a Gaussian PSF (Point Spread Function) of full width half maximum larger than 1.6 pixels. We also find that for a PSF size of a few pixels, the photometric aperture has to be at least 2.5 times larger than the PSF full width half maximum. Then, we compare a front- with a back-illuminated CCD through a Monte-Carlo simulation. Both cameras give the same results for a PSF full width half maximum larger than 1.5 pixels. All these simulations are applied to the A STEP (Antarctica Search for Transiting Extrasolar Planets) project. As a result, we choose a front-illuminated camera for A STEP because of its better resolution and lower price, and we will use a PSF larger than 1.6 pixels

Atmospheric effects of stellar cosmic rays on Earth-like exoplanets orbiting M-dwarfs

M-dwarf stars are generally considered favourable for rocky planet detection. However, such planets may be subject to extreme conditions due to possible high stellar activity. The goal of this work is to determine the potential effect of stellar cosmic rays on key atmospheric species of Earth-like planets orbiting in the habitable zone of M-dwarf stars and show corresponding changes in the planetary spectra. We build upon the cosmic rays model scheme of Grenfell et al. (2012), who considered cosmic ray induced NOx production, by adding further cosmic ray induced production mechanisms (e.g. for HOx) and introducing primary protons of a wider energy range (16 MeV - 0.5 TeV). Previous studies suggested that planets in the habitable zone that are subject to strong flaring conditions have high atmospheric methane concentrations, while their ozone biosignature is completely destroyed. Our current study shows, however, that adding cosmic ray induced HOx production can cause a decrease in atmospheric methane abundance of up to 80\%. Furthermore, the cosmic ray induced HOx molecules react with NOx to produce HNO$_3$, which produces strong HNO$_3$ signals in the theoretical spectra and reduces NOx-induced catalytic destruction of ozone so that more than 25\% of the ozone column remains. Hence, an ozone signal remains visible in the theoretical spectrum (albeit with a weaker intensity) when incorporating the new cosmic ray induced NOx and HOx schemes, even for a constantly flaring M-star case. We also find that HNO$_3$ levels may be high enough to be potentially detectable. Since ozone concentrations, which act as the key shield against harmful UV radiation, are affected by cosmic rays via NOx-induced catalytic destruction of ozone, the impact of stellar cosmic rays on surface UV fluxes is also studied.Comment: 14 pages, 12 figure

Degenerate Bose gases with uniform loss

We theoretically investigate a weakly-interacting degenerate Bose gas coupled to an empty Markovian bath. We show that in the universal phononic limit the system evolves towards an asymptotic state where an emergent temperature is set by the quantum noise of the outcoupling process. For situations typically encountered in experiments, this mechanism leads to significant cooling. Such dissipative cooling supplements conventional evaporative cooling and dominates in settings where thermalization is highly suppressed, such as in a one-dimensional quasicondensate.Comment: 9 pages, 5 figures, open access publicatio

Prospects of long-time-series observations from Dome C for transit search

The detection of transiting extrasolar planets requires high-photometric quality and long-duration photometric stellar time-series. In this paper, we investigate the advantages provided by the Antarctic observing platform Dome C for planet transit detections during its long winter period, which allows for relatively long, uninterrupted time-series. Our calculations include limiting effects due to the Sun and Moon, cloud coverage and the effect of reduced photometric quality for high extinction of target fields. We compare the potential for long time-series from Dome C with a single site in Chile, a three-site low-latitude network as well as combinations of Dome C with Chile and the network, respectively. Dome C is one of the prime astronomical sites on Earth for obtaining uninterrupted long-duration observations in terms of prospects for a high observational duty cycle. The duty cycle of a project can, however, be significantly improved by integrating Dome C into a network of sites.Comment: 10 pages, 9 figures, accepted by PAS

The effect of stellar limb darkening values on the accuracy of the planet radii derived from photometric transit observations

We study how the precision of the exoplanet radius determination is affected by our present knowledge of limb darkening in two cases: when we fix the limb darkening coefficients and when we adjust them. We also investigate the effects of spots in one-colour photometry. We study the effect of limb darkening on the planetary radius determination both via analytical expressions and by numerical experiments. We also compare some of the existing limb darkening tables. When stellar spots affect the fit, we replace the limb darkening coefficients, calculated for the unspotted cases, with effective limb darkening coefficients to describe the effect of the spots. There are two important cases. (1) When one fixes the limb darkening values according to some theoretical predictions, the inconsistencies of the tables do not allow us to reach accuracy in the planetary radius of better than 1-10% (depending on the impact parameter) if the host star's surface effective temperature is higher than 5000 K. Below 5000 K the radius ratio determination may contain even 20% error. (2) When one allows adjustment of the limb darkening coefficients, the a/Rs ratio, the planet-to-stellar radius ratio, and the impact parameter can be determined with sufficient accuracy (<1%), if the signal-to-noise ratio is high enough. However, the presence of stellar spots and faculae can destroy the agreement between the limb darkening tables and the fitted limb darkening coefficients, but this does not affect the precision of the planet radius determination. We also find that it is necessary to fit the contamination factor, too. We conclude that the present inconsistencies of theoretical stellar limb darkening tables suggests one should not fix the limb darkening coefficients. When one allows them to be adjusted, then the planet radius, impact parameter, and the a/Rs can be obtained with the required precision.Comment: Astronomy & Astrophysics Vol. 549, A9 (2013) - 11 page