Revisiting cometary bow shock positions

The Rosetta spacecraft will arrive at comet 67P/Churyumov–Gerasimenko in 2014 and will escort the comet along its journey around the Sun. The predicted outgassing rate of the comet and the solar wind properties close to its perihelion at 1.24 AU lead to the expectation that a cometary bow shock will form during the escort phase. Since the forecasts of the subsolar stand off distances differ, this study revisits selected models and presents hybrid simulations of the comet–solar wind interaction region performed with the A.I.K.E.F. code. It is shown that small variations of the solar wind parameters will shift the bow shock position considerably. In addition, a model is presented that reproduces the bow shock distances observed in the hybrid simulations.

Kinetic modeling of sodium in the lunar exosphere

Our knowledge about the lunar environment is based on a large volume of ground-based, remote, and in situ observations. These observations have been conducted at different times and sampled different pieces of such a complex system as the surface-bound exosphere of the Moon. Numerical modeling is the tool that can link results of these separate observations into a single picture. Being validated against previous measurements, models can be used for predictions and interpretation of future observations results. In this paper we present a kinetic model of the sodium exosphere of the Moon as well as results of its validation against a set of ground-based and remote observations. The unique characteristic of the model is that it takes the orbital motion of the Moon and the Earth into consideration and simulates both the exosphere as well as the sodium tail self-consistently. The extended computational domain covers the part of the Earth’s orbit at new Moon, which allows us to study the effect of Earth’s gravity on the lunar sodium tail. The model is fitted to a set of ground-based and remote observations by tuning sodium source rate as well as values of sticking, and accommodation coefficients. The best agreement of the model results with the observations is reached when all sodium atoms returning from the exosphere stick to the surface and the net sodium escape rate is about 5.3 × 1022 s−1.

ROSINA/DFMS capabilities to measure isotopic ratios in water at comet 67P/Churyumov–Gerasimenko

The likelihood that comets may have delivered part of the water to Earth has been reinforced by the recent observation of the earth-like D/H ratio in Jupiter-family comet 103P/Hartley 2 by Hartogh et al. (2011). Prior to this observation, results from several Oort cloud comets indicated a factor of 2 enrichment of deuterium relative to the abundance at Earth. The European Space Agency’s Rosetta spacecraft will encounter comet 67P/Churyumov-Gerasimenko, another Jupiter-family comet of likely Kuiper belt origin, in 2014 and accompany it from almost aphelion to and past perihelion. Onboard Rosetta is the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) which consists of two mass spectrometers and a pressure sensor [Balsiger et al. 2007]. With its unprecedented mass resolution, for a space-borne instrument, the Double Focusing Mass Spectrometer (DFMS), one of the major subsystems of ROSINA, will be able to obtain unambiguously the ratios of the isotopes in water from in situ measurements in the coma around the comet. We will discuss the performance of this sensor on the basis of measurements of the terrestrial hydrogen and oxygen isotopic ratios performed with the flight spare instrument in the lab. We also show that the instrument on Rosetta is capable of measuring the D/H even in the very low density water background released by the spacecraft. This capability demonstrates that ROSINA should obtain very sensitive measurements of these ratios in the cometary environment. These measurements will allow detection of fractionation as function of the distance from the nucleus as well as fractionation due to mechanisms that are correlated with heliocentric distance.

Modeling the heterogeneous ice and gas coma of Comet 103P/Hartley 2

The spectacular images of Comet 103P/Hartley 2 recorded by the Medium Resolution Instrument (MRI) and High Resolution Instrument (HRI) on board of the Extrasolar Planet Observation and Deep Impact Extended Investigation (EPOXI) spacecraft, as the Deep Impact extended mission, revealed that its bi-lobed very active nucleus outgasses volatiles heterogeneously. Indeed, CO2 is the primary driver of activity by dragging out chunks of pure ice out of the nucleus from the sub-solar lobe that appear to be the main source of water in Hartley 2's coma by sublimating slowly as they go away from the nucleus. However, water vapor is released by direct sublimation of the nucleus at the waist without any significant amount of either CO2 or icy grains. The coma structure for a comet with such areas of diverse chemistry differs from the usual models where gases are produced in a homogeneous way from the surface. We use the fully kinetic Direct Simulation Monte Carlo model of Tenishev et al. (Tenishev, V.M., Combi, M.R., Davidsson, B. [2008]. Astrophys. J. 685, 659-677; Tenishev, V.M., Combi, M.R., Rubin, M. [2011]. Astrophys. J. 732, 104-120) applied to Comet 103P/Hartley 2 including sublimating icy grains to reproduce the observations made by EPOXI and ground-based measurements. A realistic bi-lobed nucleus with a succession of active areas with different chemistry was included in the model enabling us to study in details the coma of Hartley 2. The different gas production rates from each area were found by fitting the spectra computed using a line-by-line non-LTE radiative transfer model to the HRI observations. The presence of icy grains with long lifetimes, which are pushed anti-sunward by radiation pressure, explains the observed OH asymmetry with enhancement on the night side of the coma.

Pharmacogenetics-based population pharmacokinetic analysis of etravirine in HIV-1 infected individuals

Objectives: Etravirine (ETV) is metabolized by cytochrome P450 (CYP) 3A, 2C9, and 2C19. Metabolites are glucuronidated by uridine diphosphate glucuronosyltransferases (UGT). To identify the potential impact of genetic and non-genetic factors involved in ETV metabolism, we carried out a two-step pharmacogenetics-based population pharmacokinetic study in HIV-1 infected individuals. Materials and methods: The study population included 144 individuals contributing 289 ETV plasma concentrations and four individuals contributing 23 ETV plasma concentrations collected in a rich sampling design. Genetic variants [n=125 single-nucleotide polymorphisms (SNPs)] in 34 genes with a predicted role in ETV metabolism were selected. A first step population pharmacokinetic model included non-genetic and known genetic factors (seven SNPs in CYP2C, one SNP in CYP3A5) as covariates. Post-hoc individual ETV clearance (CL) was used in a second (discovery) step, in which the effect of the remaining 98 SNPs in CYP3A, P450 cytochrome oxidoreductase (POR), nuclear receptor genes, and UGTs was investigated. Results: A one-compartment model with zero-order absorption best characterized ETV pharmacokinetics. The average ETV CL was 41 (l/h) (CV 51.1%), the volume of distribution was 1325 l, and the mean absorption time was 1.2 h. The administration of darunavir/ritonavir or tenofovir was the only non-genetic covariate influencing ETV CL significantly, resulting in a 40% [95% confidence interval (CI): 13–69%] and a 42% (95% CI: 17–68%) increase in ETV CL, respectively. Carriers of rs4244285 (CYP2C19*2) had 23% (8–38%) lower ETV CL. Co-administered antiretroviral agents and genetic factors explained 16% of the variance in ETV concentrations. None of the SNPs in the discovery step influenced ETV CL. Conclusion: ETV concentrations are highly variable, and co-administered antiretroviral agents and genetic factors explained only a modest part of the interindividual variability in ETV elimination. Opposing effects of interacting drugs effectively abrogate genetic influences on ETV CL, and vice-versa.

Gender differences in the association of a high quality job and self-esteem over time: A multiwave study

High self-esteem often predicts job-related outcomes, such as high job satisfaction or high status. Theoretically, high quality jobs (HQJs) should be important for self-esteem, as they enable people to use a variety of skills and attribute accomplishments to themselves, but research findings are mixed. We expected reciprocal relationships between self-esteem and HQJ. However, as work often is more important for the status of men, we expected HQJ to have a stronger influence on self-esteem for men as compared to women. Conversely, task-related achievements violate gender stereotypes for women, who may need high self-esteem to obtain HQJs. In a 4-year cross-lagged panel analysis with 325 young workers, self-esteem predicted HQJ; the lagged effect from HQJ on self-esteem was marginally significant. In line with the hypotheses, the multigroup model showed a significant path only from self-esteem to HQJ for women, and from HQJ to self-esteem for men. The reverse effect was not found for women, and only marginally significant for men. Overall, although there were some indications for reciprocal effects, our findings suggest that women need high self-esteem to obtain HQJs to a greater degree than men, and that men base their self-esteem on HQJs to a greater extent than women.

Changes in situational and dispositional factors as predictors of job satisfaction

Arguably, job satisfaction is one of the most important variables with regard to work. When explaining job satisfaction, research usually focuses on predictor variables in terms of levels but neglects growth rates. Therefore it remains unclear how potential predictors evolve over time and how their development affects job satisfaction. Using multivariate latent growth modeling in a study with 1145 young workers over five years, we analyzed how well job satisfaction is predicted a) by levels of situational (i.e., job control) and dispositional (i.e., Core Self-Evaluations (CSE)) factors and b) by growth per year of these predictors. Results showed both intercepts and slopes to be related to each other, suggesting a joint growth of job control and CSE during early careers. Job satisfaction after five years was best predicted by the slopes of job control (β = .31, p < .001) and CSE (β = .34, p < .01). These findings provide further longitudinal evidence for the role of situational as well as dispositional factors for predicting job satisfaction. In addition, growth rates per year were better predictors than initial levels. Furthermore, a lack of change in job control or CSE went along with a drop in job satisfaction, implying that young workers need to perceive things to be improving in order to increase, or at least maintain, their level of job satisfaction. In terms of theory, the relative importance of levels versus changes deserves more attention. In terms of practical implications, our results suggest a double emphasis on job design (i.e., granting sufficient, and increasing, control) and on personal development (e.g., through training) so that people experience a match between both. Finally, negative associations between initial levels and growth rates suggest that people are quite successful in achieving a reasonable fit between their job characteristics and their needs and goals.

Development of Values after Compulsory School: Work comes first, then family

During school-to-work transition, adolescents develop values and prioritize what is im-portant in their life. Values are concepts or beliefs about desirable states or behaviors that guide the selection or evaluation of behavior and events, and are ordered by their relative importance (Schwartz & Bilsky, 1987). Stressing the important role of values, career re-search has intensively studied the effect of values on educational decisions and early career development (e.g. Eccles, 2005; Hirschi, 2010; Rimann, Udris, & Weiss, 2000). Few re-searchers, however, have investigated so far how values develop in the early career phase and how value trajectories are influenced by individual characteristics. Values can be oriented towards specific life domains, such as work or family. Work values include intrinsic and extrinsic aspects of work (e.g., self-development, cooperation with others, income) (George & Jones, 1997). Family values include the importance of partner-ship, the creation of an own family and having children (Mayer, Kuramschew, & Trommsdroff, 2009). Research indicates that work values change considerably during early career development (Johnson, 2001; Lindsay & Knox, 1984). Individual differences in work values and value trajectories are found e.g., in relation to gender (Duffy & Sedlacek, 2007), parental background (Loughlin & Barling, 2001), personality (Lowry et al., 2012), educa-tion (Battle, 2003), and the anticipated timing of school-to-work transition (Porfeli, 2007). In contrast to work values, research on family value trajectories is rare and knowledge about the development during the school-to-work transition and early career development is lack-ing. This paper aims at filling this research gap. Focusing on family values and intrinsic work values and we expect a) family and work val-ues to change between ages 16 and 25, and b) that initial levels of family and work values as well as value change to be predicted by gender, reading literacy, ambition, and expected du-ration of education. Method. Using data from 2620 young adults (59.5% females), who participated in the Swiss longitudinal study TREE, latent growth modeling was employed to estimate the initial level and growth rate per year for work and family values. Analyses are based on TREE-waves 1 (year 2001, first year after compulsory school) to 8 (year 2010). Variables in the models included family values and intrinsic work values, gender, reading literacy, ambition and ex-pected duration of education. Language region was included as control variable. Results. Family values did not change significantly over the first four years after leaving compulsory school (mean slope = -.03, p =.36). They increased, however, significantly five years after compulsory school (mean slope = .13, p >.001). Intercept (.23, p < .001), first slope (.02, p < .001), and second slope (.01, p < .001) showed significant variance. Initial levels were higher for men and those with higher ambitions. Increases were found to be steeper for males as well as for participants with lower educational duration expectations and reading skills. Intrinsic work values increased over the first four years (mean slope =.03, p <.05) and showed a tendency to decrease in the years five to ten (mean slope = -.01, p < .10). Intercept (.21, p < .001), first slope (.01, p < .001), and second slope (.01, p < .001) showed signifi-cant variance, meaning that there are individual differences in initial levels and growth rates. Initial levels were higher for females, and those with higher ambitions, expecting longer educational pathways, and having lower reading skills. Growth rates were lower for the first phase and steeper for the second phase for males compared to females. Discussion. In general, results showed different patterns of work and family value trajecto-ries, and different individual factors related to initial levels and development after compul-sory school. Developments seem to fit to major life and career roles: in the first years after compulsory school young adults may be engaged to become established in one's job; later on, raising a family becomes more important. That we found significant gender differences in work and family trajectories may reflect attempts to overcome traditional roles, as over-all, women increase in work values and men increase in family values, resulting in an over-all trend to converge.

Changes in skill variety predict job satisfaction and psychosomatic complaints

Purpose Skill variety in terms of opportunities for utilizing different skills is an important element of job design; it is associated with well-being and health, but most pertinent research is cross-sectional. Positive associations with well-being, and with intellectual flexibility, have been shown longitudinally, but these studies focus on levels of skill variety at time 1 and do not use changes in skill variety as a predictor. We expect changes in skill variety to be associated with well-being in terms of higher job satisfaction and fewer psychosomatic complaints. Design/Methodology Skill variety, job satisfaction, and psychosomatic complaints were assessed in 2005, 2006, 2007, and 2010 (N = 317 young employees). Data were analyzed using latent growth modeling. Results Skill variety decreased over the first three years after labor market entry. Initial levels of skill variety predicted higher job satisfaction in 2010. Steeper decreases in skill variety from 2005 to 2007 predicted lower levels of job satisfaction and more psychosomatic complaints three years later. Limitations This longitudinal study used only self-report. Research/Practical Implications Our results extend the often found association between challenging work content and job satisfaction in terms of a) showing it for young employees, b) longitudinally, c) not only for initial level but also for changes, and d) for psychosomatic complaints; they underscore the importance of maintaining a high level of challenging work content beyond the initial phase by enriching work as routine increases. Originality/Value Compared to the few existing longitudinal studies, we focus on changes and their relations with well-being.

Psychological, Educational and Sociological Perspectives on Success and Well-Being in Career Development

Back Cover Text This collection covers how success and well-being relate to each other in early career development in the domains of employment and education. It gives a conceptual overview of success and well-being as established in the psychological research tradition, complemented by educational and sociological approaches. The volume presents articles on success and well-being in applied contexts, such as well-being as an individual resource during school-to-work transition, or well-being and success at the workplace. Work psychologists, social psychologists, educational researchers, and sociologists will find this book valuable, as it provides unique insights into social and psychological processes afforded by the combination of disciplines, concepts, and a diversity of approaches. Table of Contents Acknowledgements 1. Introduction Robin Samuel, Manfred Max Bergman, Anita C. Keller and Norbert K. Semmer 2. The Influence of Career Success on Subjective Well-Being Andrea E. Abele-Brehm 3. Upper-Secondary Educational Trajectories and Young Men’s and Women’s Self-Esteem Development in Switzerland Sybille Bayard, Monika Staffelbach, Phillip Fischer and Marlies Buchmann. 4. Young People’s Progress after Dropout from Vocational Edu-cation and Training: Transitions and Occupational Integration at Stake. Longitudinal Qualitative Perspective Barbara Duc and Nadia Lamamra 5. Success, Well-Being and Social Recognition: An Interactional Perspective on Vocational Training Practices Stefano A. Losa, Barbara Duc and Laurent Filliettaz. 6. Agentic Pathways toward Fulfillment in Work Jeylan T. Mortimer, Mike Vuolo and Jeremy Staff 7. The How and Why of the Relationship between Job Insecuri-ty, Subjective Career Success, and Turnover Intention Cécile Tschopp and Gudela Grote 8. Work Experiences and Well-Being in the First Years of Professional Work in Switzerland: A Ten-Year Follow-up Study Wolfgang Kälin, Anita C. Keller, Franziska Tschan, Achim Elfering and Norbert K. Semmer 9. The Meaning and Measurement of Well-Being as an Indicator of Success Anita C. Keller, Norbert K. Semmer, Robin Samuel and Manfred Max Bergman

Do Integration Policies Affect Immigrants' Voluntary Engagement? An Exploration at Switzerland's Subnational Level

This paper investigates whether integration policies influence immigrants' propensity to volunteer, the latter being an important element of immigrants' integration into the host society. By distinguishing different categories of integration policies at Switzerland's subnational level and applying a Bayesian multilevel approach, our results suggest varying policy effects: while policies fostering socio-structural rights enhance immigrants' propensity to volunteer, we observe a negative curvilinear relationship between cultural rights and obligations and immigrants' volunteerism implying that a combination of cultural entitlements and obligations is most conducive to immigrants' civic engagement.