K-shell photoionization of ground-state Li-like carbon ions [C3+^{3+}]: experiment, theory and comparison with time-reversed photorecombination

Absolute cross sections for the K-shell photoionization of ground-state Li-like carbon [C$^{3+}$(1s$^2$2s $^2$S)] ions were measured by employing the ion-photon merged-beams technique at the Advanced Light Source. The energy ranges 299.8--300.15 eV, 303.29--303.58 eV and 335.61--337.57 eV of the [1s(2s2p)$^3$P]$^2$P, [1s(2s2p)$^1$P]$^2$P and [(1s2s)$^3$S 3p]$^2$P resonances, respectively, were investigated using resolving powers of up to 6000. The autoionization linewidth of the [1s(2s2p)$^1$P]$^2$P resonance was measured to be $27 \pm 5$ meV and compares favourably with a theoretical result of 26 meV obtained from the intermediate coupling R-Matrix method. The present photoionization cross section results are compared with the outcome from photorecombination measurements by employing the principle of detailed balance.Comment: 3 figures and 2 table

Astrophysical Relevance of Storage-Ring Electron-Ion Recombination Experiments

The relevance of storage-ring electron-ion recombination experiments for astrophysics is outlined. In particular, the role of low-energy dielectronic-recombination resonances is discussed. A bibliographic compilation of electron-ion recombination measurements with cosmically abundant ions is provided.Comment: 8 pages, 3 figures, 1 table, 77 references, Proceedings of the 14th International Conference on the Physics of Highly Charged Ions, Cofu, Tokyo, Septmber 1-5, 2008, to be published in J. Phys. Conf. Se

Reflective Goal-Setting Improves Academic Performance in Teacher and Business Education: A Large-Scale Field Experiment

Students often have trouble adjusting to higher education and this affects their performance, retention, and well-being. Scholars have suggested applying reflective goal- setting interventions, and most have found positive effects on academic performance and retention. However, one study found no effect at all, stressing the need for understanding the underlying mechanisms, as they could explain when the intervention works and why. Thus, we assessed these mechanisms through a rigorous effect test, using an experimental design and repeated measures. We measured engagement, self-regulated learning, resilience, grit, wellbeing, academic performance, and retention at three points in a large scale randomized controlled trial involving first-year teacher and business education students (N = 1,134). The treatment group earned significantly more course credits and had lower drop out rates. Contrary to previous findings, these effects were independent of gender or ethnicity. Grit, self-regulated learning, resilience, or engagement did not mediate the effects. This study confirmed reflective goal-setting’s small and direct effect on academic performance, but no mediating or moderating effects. Differences in implementation fidelity could explain previous studies’ varying effect-sizes

Electron-ion recombination of Si IV forming Si III: Storage-ring measurement and multiconfiguration Dirac-Fock calculations

The electron-ion recombination rate coefficient for Si IV forming Si III was measured at the heavy-ion storage-ring TSR. The experimental electron-ion collision energy range of 0-186 eV encompassed the 2p(6) nl n'l' dielectronic recombination (DR) resonances associated with 3s to nl core excitations, 2s 2p(6) 3s nl n'l' resonances associated with 2s to nl (n=3,4) core excitations, and 2p(5) 3s nl n'l' resonances associated with 2p to nl (n=3,...,infinity) core excitations. The experimental DR results are compared with theoretical calculations using the multiconfiguration Dirac-Fock (MCDF) method for DR via the 3s to 3p n'l' and 3s to 3d n'l' (both n'=3,...,6) and 2p(5) 3s 3l n'l' (n'=3,4) capture channels. Finally, the experimental and theoretical plasma DR rate coefficients for Si IV forming Si III are derived and compared with previously available results.Comment: 13 pages, 9 figures, 3 tables. Accepted for publication in Physical Review

Isotope shift in the dielectronic recombination of three-electron ^{A}Nd^{57+}

Isotope shifts in dielectronic recombination spectra were studied for Li-like ^{A}Nd^{57+} ions with A=142 and A=150. From the displacement of resonance positions energy shifts \delta E^{142,150}(2s-2p_1/2)= 40.2(3)(6) meV (stat)(sys)) and \delta E^{142,150}(2s-2p_3/2) = 42.3(12)(20) meV of 2s-2p_j transitions were deduced. An evaluation of these values within a full QED treatment yields a change in the mean-square charge radius of ^{142,150}\delta = -1.36(1)(3) fm^2. The approach is conceptually new and combines the advantage of a simple atomic structure with high sensitivity to nuclear size.Comment: 10 pages, 3 figures, accepted for publication in Physical Review Letter

The Right Job Pays; Effects of Student Employment on the Study Progress of Pre-service Teachers

Spending time on work during a full-time study might compete with class attendance or self-study and slow study progress. At the same time, a domain-relevant job may grant beneficial effects that enhance academic outcomes. Prior research showed contradictory findings, possibly because of a lack of distinction between types of work and the different years of college. The current study analyzed the effect of different types of work on the study progress of 132 Dutch pre-service teachers with repeated measures at 25 points in time over a 4-year timespan using growth models. Students who spent more time on a paid job as a teacher obtained significantly more study credits. The optimal number of hours spent on paid work outside of education changes during college. These findings support the importance of study-job-congruence and add the roles of timing (year of college) and remuneration (getting paid) as relevant variables to role-based resource theory

Preoperative apolipoprotein CI levels correlate positively with the proinflammatory response in patients experiencing endotoxemia following elective cardiac surgery

Objective: Experimental models show that apolipoprotein CI (apoCI) binds and enhances the inflammatory response to endotoxin. We studied in patients undergoing cardiopulmonary bypass surgery (CPB) and experiencing endotoxemia during reperfusion whether plasma apoCI levels correlate with the inflammatory response and perioperative cytokine release. Design: Prospective, observational, clinical cohort study. Setting: Operating room (OR) and intensive care unit (ICU) of a university hospital. Patients: One hundred fifty-nine consecutive patients > 18 years of age (66% males (n = 105), median age 65 and 67 years for males and females, respectively) undergoing elective cardiothoracic surgery with cardiopulmonary bypass. Interventions: None. Measurements: Baseline apoCI, apoCIII, total cholesterol and triglyceride levels, and perioperative endotoxin and TNF-α levels were determined. Results: High preoperative plasma apoCI, but not apoCIII, levels were associated (p < 0.05) with increased perioperative levels of TNF-α in patients experiencing endotoxemia. This association was not observed in patients without endotoxemia. Conclusion: High plasma apoCI is positively related to proinflammatory response in patients experiencing endotoxemia and confirms the observations in animal models. © 2008 The Author(s)

K-shell photoionization of ground-state Li-like boron ions [B2+^{2+}]: Experiment and Theory

Absolute cross sections for the K-shell photoionization of ground-state Li-like boron [B$^{2+}$(1s$^2$2s $^2$S)] ions were measured by employing the ion-photon merged-beams technique at the Advanced Light Source synchrotron radiation facility. The energy ranges 197.5--200.5 eV, 201.9--202.1 eV of the [1s(2s\,2p)$^3$P]$^2$P${\rm ^o}$ and [1s(2s\,2p)$^1$P] $^2$P${\rm ^o}$ resonances, respectively, were investigated using resolving powers of up to 17\,600. The energy range of the experiments was extended to about 238.2 eV yielding energies of the most prominent [1s(2$\ell$\,n$\ell^{\prime}$)]$^2$P$^o$ resonances with an absolute accuracy of the order of 130 ppm. The natural linewidths of the [1s(2s\,2p)$^3$P] $^2$P${\rm ^o}$ and [1s(2s\,2p)$^1$P] $^2$P${\rm ^o}$ resonances were measured to be $4.8 \pm 0.6$ meV and $29.7 \pm 2.5$ meV, respectively, which compare favourably with theoretical results of 4.40 meV and 30.53 meV determined using an intermediate coupling R-matrix method.Comment: 6 figures and 2 table

Fostering Flexibility in the New World of Work: A Model of Time-Spatial Job Crafting

In today’s “new world of work,” knowledge workers are often given considerable flexibility regarding where and when to work (i.e., time-spatial flexibility) and this has become a popular approach to redesigning work. Whilst the adoption of such practices is mainly considered a top-down approach to work design, we argue that successful utilization of time-spatial flexibility requires proactivity on the part of the employee in the form of time-spatial job crafting. Previous research has demonstrated that time-spatial flexibility can have both positive and negative effects on well-being, performance, and work-life balance; yet remains mute about the underlying reasons for this and how employees can handle the given flexibility. Drawing on research from work design, we posit that in order for employees to stay well and productive in this context, they need to engage in time-spatial job crafting (i.e., a context-specific form of job crafting that entails reflection on time and place), which can be considered a future work skill. We propose a theoretical model of time-spatial job crafting in which we discuss its components, shed light on its antecedents, and explain how time-spatial job crafting is related to positive work outcomes through a time/spatial-demands fit