Fueled by a Fearful Leader: When, to What Extent and How Leader Fear of COVID-19 Promotes Employee Performance

The literature generally surmises that negative affective states of leaders are detrimental to leader effectiveness and work outcomes. Taking the opposite view, this study explores how the negative affective experiences of leaders related to COVID-19 may foster team commitment and employee performance. By integrating personality systems interaction theory, cognitive appraisal theory, and the literature on stress-based emotions, we develop a model that clarifies when, how, and to what extent leader fearful states related to COVID-19 drive employee performance. Using three-wave and multisource data from 579 employees and their leaders from 69 teams, we found that among leaders who exhibited higher levels of positive affectivity, leader fear of COVID-19 indirectly fostered employee performance via the mediating roles of leader promotion of team goals and team commitment. Moreover, these moderated indirect effects were strongest at moderate levels of leader fear of COVID-19. We discuss the theoretical and practical implications of these findings for research on leader affective states

Residual doses in recent alluvial sediments from the ardenne (S Belgium)

peer reviewedWe report on our first investigations into the potential of optical dating for determining the rate of river flood sedimentation in the Ardenne region (S Belgium). Two samples collected from a recent alluvial deposit were used to investigate the extent of resetting in different particle size fractions of quartz (4-11 mu m, 63-90 mu m, 90-125 mu m, 125-180 mu m, 180-212 mu m and 212-250 mu m) as well as in polymineral fine (4-11 mu m) grains. Both samples show satisfactory OSL and IRSL characteristics. The IRSL signals from the polymineral fine grains yield an equivalent dose (D-e) of 3-4 Gy, while a D-e of 0.3-0.6 Gy was measured using large aliquots of quartz. Small aliquot analyses of 63-90 mu m and 212-250 mu m quartz grains confirm that the coarser fraction contains more grains with lower D-e's. Furthermore, for a modern sample (< 3 years old), similar to 60% of the aliquots yields a D-e consistent with zero, indicating that these contain only well-bleached grains. These findings suggest that it might be possible to extract the true burial dose from dose distributions measured using small aliquots of coarse-grained (e.g. 212-250 mu m) quartz

Suivi de la lixiviation du nitrate en plein champ par la technique lysimétrique : retour de huit années d'expérience

Monitoring of nitrate leaching in open fields by lysimeters: results from an eight year study. Since 2003, nitrate leaching has been monitored in six plots located in a loamy area (Hesbaye, Belgium), mainly dedicated to wheat, sugarbeet and vegetable crops. Open-field lysimeters have been used in order not to impede agricultural operations. Lysimeters are used as follow-up tools to quantify the amounts of nitrate leaching below the root zone. This study aims to evaluate the suitability of PLN (Potentially Leachable Nitrogen – APL in French) defined in the Sustainable Nitrogen Management Program (PGDA in French) as an environmental indicator by relating nitrogen management practices (including fertilization recommendations) to PLN values and groundwater quality. This study demonstrates that lysimeters are efficient in collecting representative amounts of leaching water. Lysimeters show that PLN is identified as being related to the nitrate content in leaching water, which will not be taken up by the next crop. The amount of nitrate leaching below the root zone demonstrates the necessity and the relevance of the organic nitrogen spreading limits defined in the Sustainable Nitrogen Management Program. The lysimeter tool also shows that respect for leaching water quality standards under agricultural plots needs to be considered from an integrated and generalized approach, taking into account complete crop sequences and rotations, including rational fertilization rates and the introduction of catch crops in rotation. Some suitable or unsuitable crop sequences with regard to good groundwater quality are listed

Generalized phonon-assisted Zener tunneling in indirect semiconductors with non-uniform electric fields : a rigorous approach

A general framework to calculate the Zener current in an indirect semiconductor with an externally applied potential is provided. Assuming a parabolic valence and conduction band dispersion, the semiconductor is in equilibrium in the presence of the external field as long as the electronphonon interaction is absent. The linear response to the electron-phonon interaction results in a non-equilibrium system. The Zener tunneling current is calculated from the number of electrons making the transition from valence to conduction band per unit time. A convenient expression based on the single particle spectral functions is provided, enabling the numerical calculation of the Zener current under any three-dimensional potential profile. For a one dimensional potential profile an analytical expression is obtained for the current in a bulk semiconductor, a semiconductor under uniform field and a semiconductor under a non-uniform field using the WKB (Wentzel-Kramers-Brillouin) approximation. The obtained results agree with the Kane result in the low field limit. A numerical example for abrupt p - n diodes with different doping concentrations is given, from which it can be seen that the uniform field model is a better approximation than the WKB model but a direct numerical treatment is required for low bias conditions.Comment: 29 pages, 7 figure

Evaluating the adequacy of social-emotional measures in early childhood

Technical adequacy and usability are important considerations in selecting early childhood social-emotional (SE) screening and assessment measures. As identification of difficulties can be tied to programming, intervention, accountability, and funding, it is imperative that practitioners and decision makers select appropriate and quality measures from the plethora of measures available. This study systematically reviewed and evaluated the technical adequacy and usability of 10 commonly used SE assessment and screening measures, using a framework for evaluating selected properties of measures (e.g., reliability, validity). Through this review, it was found that there are inadequacies in many commonly used SE measures, deserving the attention of both users and developers