Interstellar 12C/13C from CH+ absorption lines: Results from an extended survey

The 12C/13C isotope ratio in the interstellar medium (ISM), and its evolution with time, is an important tracer of stellar yields. Spatial variations of this ratio can be used to study mixing in the ISM. We want to determine this ratio and its spatial variations in the local ISM from CH+ absorption lines in the optical towards early-type stars. The aim is to determine the average value for the local ISM and study possible spatial variations. We observed a large number of early-type stars with Feros to extend the sample of suitable target stars for CH+ isotope studies. The best suited targets were observed with Uves with higher signal-to-noise ratio and spectral resolution to determine the isotope ratio from the interstellar CH+ lines. This study significantly expands the number of 13CH+ detections. We find an average ratio of = 76.27 +- 1.94 or, for f = 1/R, = (120.46 +- 3.02) 10^{-4}. The scatter in f is 6.3 sigma(). This findings strengthens the case for chemical inhomogeneity in the local ISM, with important implications for the mixing in the ISM. Given the large scatter, the present-day value in the ISM is not significantly larger than the solar value, which corresponds to the local value 4.5 Gyr ago.Comment: 11 pages, 16 figures, 2 tables, A&A submitte

Intergenerational Transmission of Health-promoting Behaviors: Examining Participation in Physical Activity between Middle-aged Mothers and their Younger Adult Children

Research has provided considerable evidence that participation in regular physical activity is associated with numerous physical and mental health benefits (Penedo & Dahn, 2005). Despite public health efforts to increase the activity levels adults, only 25% of the U.S. adult population is regularly active and nearly 60% remains sedentary (US Department of Health and Human Services [USDHHS], 2008). A small, but growing, area of research has examined physical activity from an intergenerational or dyadic perspective that considers how involvements in close, personal relationships influence levels of physical activity. In a sample of middle-aged mothers and their younger adult children, the present study had three primary objectives: (a) to examine the relations among well-known predictors of physical activity in younger adulthood and midlife, (b) to examine the relations between individual characteristics and interpersonal variables on physical activity within mother-child dyads, and (c) to examine whether mothers influenced their daughters more strongly than their sons. Data from 48 mother-child dyads between the ages of 18 and 57 were collected via an online survey. Findings from the first research objective indicate an adequate fit of the model to the data for middle-aged mothers (chi2 (df = 2; N = 48) = 2.938, p = .230) and younger adults (chi 2 (df = 3; N = 48) = .288, p = .962). With regard to the second research objective, results indicated an adequate fit of the model to the data chi2 (df = 6; N = 48) = 5.057, p = .537. The hypothesized model explained 2.4% of variance in younger adults\u27 physical activity and 17.5% of variance in middle-aged mothers\u27 physical activity. In addition, standardized beta weights provided support for one actor effect, as mothers\u27 internal health locus of control was positively associated with physical activity. (beta = .42). Research objective three was not supported. Findings from this study may help inform the design of future health interventions. Specifically, the results suggest that personal relationships, such as the relationship one has with a family member, may play a role in understanding participation in physical activity

Health promotion during midlife: The influence of internal health locus of control and future time perspective

Health promoting behaviors are typically categorized as behaviors that move individuals towards optimal health while concurrently decreasing one\u27s susceptibility to disease and illness (Becker & Arnold, 2004; Breslow, 1999). When compared to other developmental age periods, less is known about health promotion in midlife (Merrill & Verbrugge, 1999). Thus, the present study examined the relations among demographic variables, future time perspective, internal health locus of control, and middle-aged adults\u27 engagement in health promotion. Data from 109 middle-aged adults between the ages of 40 and 66 were collected via an online survey. Results indicated that the data fit the model poorly chi2 (df = 6;N = 109) = 13.791 p \u3c .05), CFI = .867, TLI = .667, RMSEA = .110. Despite the poor fit, the path model accounted for a substantial amount of variance in health promotion ( R2 = .30). The model indicated that future time perspective and internal health locus of control were associated with engagement in health promotion. In addition, both age and adults\u27 perceptions of the severity of their chronic health conditions were associated with future time perspective. Findings from this study may help inform the design of health interventions. Specifically, results suggest that interventions should consider integrating future time perspective into a theoretical framework in understanding why middle-aged adults choose to engage in health promotion

Incorporating Skew into RMS Surface Roughness Probability Distribution

The standard treatment of RMS surface roughness data is the application of a Gaussian probability distribution. This handling of surface roughness ignores the skew present in the surface and overestimates the most probable RMS of the surface, the mode. Using experimental data we confirm the Gaussian distribution overestimates the mode and application of an asymmetric distribution provides a better fit. Implementing the proposed asymmetric distribution into the optical manufacturing process would reduce the polishing time required to meet surface roughness specifications

Effective Governance of Global Financial Markets:An Evolutionary Plan for Reform

Runaway electrons, which are generated in a plasma where the induced electric field exceeds a certain critical value, can reach very high energies in the MeV range. For such energetic electrons, radiative losses will contribute significantly to the momentum space dynamics. Under certain conditions, due to radiative momentum losses, a non-monotonic feature - a ‘bump' - can form in the runaway electron tail, creating a potential for bump-on-tail-type instabilities to arise. Here, we study the conditions for the existence of the bump. We derive an analytical threshold condition for bump appearance and give an approximate expression for the minimum energy at which the bump can appear. Numerical calculations are performed to support the analytical derivation

Measuring Skew in Average Surface Roughness as a Function of Surface Preparation

Characterizing surface roughness is important for predicting optical performance. Better measurement of surface roughness reduces grinding saving both time and money and allows the science requirements to be better defined. In this study various materials are polished from a fine grind to a fine polish. Each sample's RMS surface roughness is measured at 81 locations in a 9x9 square grid using a Zygo white light interferometer at regular intervals during the polishing process. Each data set is fit with various standard distributions and tested for goodness of fit. We show that the skew in the RMS data changes as a function of polishing time

Similarity Measure Development for Case-Based Reasoning- A Data-driven Approach

In this paper, we demonstrate a data-driven methodology for modelling the local similarity measures of various attributes in a dataset. We analyse the spread in the numerical attributes and estimate their distribution using polynomial function to showcase an approach for deriving strong initial value ranges of numerical attributes and use a non-overlapping distribution for categorical attributes such that the entire similarity range [0,1] is utilized. We use an open source dataset for demonstrating modelling and development of the similarity measures and will present a case-based reasoning (CBR) system that can be used to search for the most relevant similar cases

Long-term spectroscopic monitoring of the Luminous Blue Variable HD160529

We have spectroscopically monitored the galactic Luminous Blue Variable HD 160529 and obtained an extensive high-resolution data set that covers the years 1991 to 2002. During this period, the star evolved from an extended photometric minimum phase towards a new visual maximum. In several observing seasons, we covered up to four months with almost daily spectra. Our spectra typically cover most of the visual spectral range with a high spectral resolution (about 20,000 or more). This allows us to investigate the variability in many lines and on many time scales from days to years. We find a correlation between the photospheric HeI lines and the brightness of the star, both on a time scale of months and on a time scale of years. The short-term variations are smaller and do not follow the long-term trend, strongly suggesting different physical mechanisms. Metal lines also show both short-term and long-term variations in strength and also a long-term trend in radial velocity. Most of the line-profile variations can be attributed to changing strengths of lines. Propagating features in the line profiles are rarely observed. We find that the mass-loss rate of HD 160529 is almost independent of temperature, i.e. visual brightness.Comment: 14 pages, 15 figures, accepted for publication in Astronomy & Astrophysic