Super-directional light emission and emission reversal from micro cavity arrays

Optical microdisk cavities with certain asymmetric shapes are known to possess unidirectional far-field emission properties. Here, we investigate arrays of these dielectric microresonators with respect to their emission properties resulting from the coherent behaviour of the coupled constituents. This approach is inspired by electronic mesoscopic physics where the additional interference effects are known to enhance the properties of the individual system. As an example we study the linear arrangement of nominally identical Lima\c{c}on-shaped cavities and find mostly an increase of the portion of directional emitted light while its angular spread is largely diminished from 20 degrees for the single cavity to about 3 degrees for a linear array of 10 Lima\c{c}on resonators, in fair agreement with a simple array model. Moreover, by varying the inter-cavity distance we observe windows of reversion of the emission directionality and super-directionality that can be interesting for applications. We introduce a generalized array factor model that takes the coupling into account.Comment: 5 pages, 5 figures, supplemental materia

Serving followers or family? A trickle down model of how servant leadership shapes employee work performance

So far, little research attention has been given to the effects of servant leadership displayed by leaders across an organization’s hierarchy. Using a matched sample of employees and their supervisors from three companies in the Dominican Republic, multilevel structural equation modeling results show that manager servant leadership trickles down to inspire supervisor servant leadership, which increases employee prosocial motivation and subsequent work performance. Furthermore, supervisor family motivation buffered the trickle-down mechanism, so that the effect on employee work performance is weaker for supervisors with high levels of family motivation. Our research sheds light on how and when servant leadership tickles down to shape employee work performance

Family motivation of supervisors: Exploring the impact on subordinates’ work performance via family supportive supervisor behaviors and work–family balance satisfaction

Family supportive supervisor behaviors (FSSB) have emerged as a powerful resource of informal support for the well-being and development of employees. However, research to date offers limited insight into the antecedents and underlying processes that may trigger FSSBs. We investigate the association between family motivation of supervisors and FSSBs, and how the latter mediates the association between supervisors’ family motivation and subordinates’ work performance. Furthermore, we examine the role of supervisors’ satisfaction with their work–family balance as a contextual variable influencing our proposed associations. We draw on FSSB and perspective taking theory as over-arching frameworks for our hypotheses. Using matched and multisource supervisor-subordinate data collected from an organization in Chile (196 subordinates and 75 supervisors), our findings revealed that FSSBs are mechanisms linking supervisors’ family motivation to subordinates’ work performance. Interestingly, this positive association is moderated by supervisors’ satisfaction with their work–family balance, such that the mediation of FSSBs is stronger for supervisors who are not satisfied with their work–family balance

Serving followers and family?:A trickle-down model of how servant leadership shapes employee work performance

Previous studies have identified servant leadership as an important driver of organizational effectiveness. However, so far little research attention has been given to whether servant leadership displayed by leaders across an organization’s hierarchy can increase the effectiveness of its members. In this study, we integrate prosociality models with role motivation theory to examine how manager servant leadership trickles down to affect employee work performance as well as the role of supervisor family motivation in influencing the trickle-down process. Using a matched sample of employees and their supervisors from three companies in the Dominican Republic, multilevel structural equation modeling results show that manager servant leadership trickles down to inspire supervisor servant leadership, which in turn increases employee prosocial motivation and subsequent work performance. Furthermore, supervisor family motivation buffers the trickle-down mechanism in that the effect on employee work performance is weaker for supervisors with high levels of family motivation. Our research breaks new ground by shedding light on how and when servant leadership trickles down to shape employee work performance

Serving followers and family?:A trickle-down model of how servant leadership shapes employee work performance

Previous studies have identified servant leadership as an important driver of organizational effectiveness. However, so far little research attention has been given to whether servant leadership displayed by leaders across an organization’s hierarchy can increase the effectiveness of its members. In this study, we integrate prosociality models with role motivation theory to examine how manager servant leadership trickles down to affect employee work performance as well as the role of supervisor family motivation in influencing the trickle-down process. Using a matched sample of employees and their supervisors from three companies in the Dominican Republic, multilevel structural equation modeling results show that manager servant leadership trickles down to inspire supervisor servant leadership, which in turn increases employee prosocial motivation and subsequent work performance. Furthermore, supervisor family motivation buffers the trickle-down mechanism in that the effect on employee work performance is weaker for supervisors with high levels of family motivation. Our research breaks new ground by shedding light on how and when servant leadership trickles down to shape employee work performance

The tone at the top: A trickle-down model of how manager anger relates to employee moral behaviour

The question of how leaders’ expressions of anger influence employees have been the subject of considerable scholarly debate. So far, however, research on the consequences of angry leadership has predominantly focused on the effects of supervisor expressions of anger, neglecting the potential influence of higher-level managerial anger. In this study, we integrate the emotions as social information theory with the adapted elaboration likelihood model to examine how manager anger trickles down across organizational hierarchical levels (i.e., managers, supervisors, and employees) to affect employee moral behaviour. Results of a multi-source field study conducted in Chile demonstrate that perceptions of manager moral behaviour and supervisor servant leadership serially mediate a negative relationship between manager anger and employee moral behaviour. Furthermore, counter to our predictions, trait negative affectivity of supervisors did not moderate the trickle-down relation of manager anger on employee moral behaviour. Our research elucidates the process by which manager anger can “set the tone” in an organization and trickle down across hierarchical levels to predict the moral behaviour of employees

How do weekly obtained task i-deals improve work performance? The role of relational context and structural job resources

Previous research on idiosyncratic deals (i-deals) has treated them as concrete events, arguing that these i-deals shape employment relationships and impact on work performance over long periods of time. However, some types of i-deals may be negotiated and shaped over short periods of time. The aim of this research is to understand the social context within which these types of i-deals unfold and influence employee work performance. Focusing on task i-deals and adopting a weekly diary design approach, we explore the role of relationship quality with co-workers and managers that matter for the obtainment of task i-deals and how obtained task i-deals translate into work performance, over weeks. To explore our research questions, we collected weekly diary data (over 7 weeks; n = 67 employees; 67 co-workers and 23 managers) from employees, their co-workers and managers. The results from multi-level analyses demonstrate that weekly reports of co-worker support matter more to obtain task i-deals than employee’s relationship quality with their manager. Furthermore, results underline that weekly structural job resources explain how and why obtained task i-deals lead to enhanced work performance over weeks. HR managers and practitioners can design task i-deals as short-term intervention tools to drive work performance

Orbital decomposition of CALIFA spiral galaxies

Schwarzschild orbit-based dynamical models are widely used to uncover the internal dynamics of early-type galaxies and globular clusters. Here we present for the first time the Schwarzschild models of late-type galaxies: an SBb galaxy NGC4210 and an S0 galaxy NGC6278 from the Calar Alto Legacy Integral Field Area (CALIFA) survey. The mass profiles within 2R(e) are constrained well with 1 sigma statistical error of similar to 10 per cent. The luminous and dark mass can be disentangled with uncertainties of similar to 20 and similar to 50 per cent, respectively. From Re to 2Re, the dark matter fraction increases from 14 +/- 10 to 18 +/- 10 per cent for NGC4210 and from 15 +/- 10 to 30 +/- 20 per cent for NGC6278. The velocity anisotropy profiles of both sigma(r)/sigma(t) and sigma(z)/sigma(R) are well constrained. The inferred internal orbital distributions reveal clear substructures. The orbits are naturally separated into three components: a cold component with near circular orbits; a hot component with near radial orbits and a warm component in between. The photometrically identified exponential discs are predominantly made up of cold orbits only beyond similar to 1R(e), while they are constructed mainly with the warm orbits inside. Our dynamical hot components are concentrated in the inner regions, similar to the photometrically identified bulges. The reliability of the results, especially the orbit distribution, is verified by applying the model to mock data.</p

Post-starburst galaxies: more than just an interesting curiosity

From the VIMOS VLT DEEP Survey (VVDS) we select a sample of 16 galaxies with spectra which identify them as having recently undergone a strong starburst and subsequent fast quenching of star formation. These post-starburst galaxies lie in the redshift range 0.510^9.75Msun. They have a number density of 1x10^-4 per Mpc^3, almost two orders of magnitude sparser than the full galaxy population with the same mass limit. We compare with simulations to show that the galaxies are consistent with being the descendants of gas rich major mergers. Starburst mass fractions must be larger than ~5-10% and decay times shorter than ~10^8 years for post-starburst spectral signatures to be observed in the simulations. We find that the presence of black hole feedback does not greatly affect the evolution of the simulated merger remnants through the post-starburst phase. The multiwavelength spectral energy distributions of the post-starburst galaxies show that 5/16 have completely ceased the formation of new stars. These 5 galaxies correspond to a mass flux entering the red-sequence of rhodot(A->Q, PSB) = 0.0038Msun/Mpc^3/yr, assuming the defining spectroscopic features are detectable for 0.35Gyr. If the galaxies subsequently remain on the red sequence, this accounts for 38(+4/-11)% of the growth rate of the red sequence. Finally, we compare our high redshift results with a sample of galaxies with 0.05<z<0.1 observed in the SDSS and UKIDSS surveys. We find a very strong redshift evolution: the mass density of strong post-starburst galaxies is 230 times lower at z~0.07 than at z~0.7.Comment: 18 pages, 12 figures, to match version accepted to MNRAS. Minor reordering of text in places and Sec 2.2 on SPH simulation comparisons expande

Grow With the Challenge – Microbial Effects on Epithelial Proliferation, Carcinogenesis, and Cancer Therapy

The eukaryotic host is in close contact to myriads of resident and transient microbes, which influence the crucial physiological pathways. Emerging evidence points to their role of host–microbe interactions for controlling tissue homeostasis, cell fate decisions, and regenerative capacity in epithelial barrier organs including the skin, lung, and gut. In humans and mice, it has been shown that the malignant tumors of these organs harbor an altered microbiota. Mechanistic studies have shown that the altered metabolic properties and secreted factors contribute to epithelial carcinogenesis and tumor progression. Exciting recent work points toward a crucial influence of the associated microbial communities on the response to chemotherapy and immune-check point inhibitors during cancer treatment, which suggests that the modulation of the microbiota might be a powerful tool for personalized oncology. In this article, we provide an overview of how the bacterial signals and signatures may influence epithelial homeostasis across taxa from cnidarians to vertebrates and delineate mechanisms, which might be potential targets for therapy of human diseases by either harnessing barrier integrity (infection and inflammation) or restoring uncontrolled proliferation (cancer)