Valley-addressable polaritons in atomically thin semiconductors

The locking of the electron spin to the valley degree of freedom in transition metal dichalcogenide (TMD) monolayers has seen these materials emerge as a promising platform in valleytronics. When embedded in optical microcavities, the large oscillator strengths of excitonic transitions in TMDs allow the formation of polaritons that are part-light part-matter quasiparticles. Here, we report that polaritons in MoSe2 show an efficient retention of the valley pseudospin contrasting them with excitons and trions in this material. We find that the degree of the valley pseudospin retention is dependent on the photon, exciton and trion fractions in the polariton states. This allows us to conclude that in the polaritonic regime, cavity-modified exciton relaxation inhibits loss of the valley pseudospin. The valley-addressable exciton-polaritons and trion-polaritons presented here offer robust valley-polarized states with the potential for valleytronic devices based on TMDs embedded in photonic structures and valley-dependent nonlinear polariton–polariton interactions

Chk2 mediates RITA-induced apoptosis

Reactivation of the p53 tumor-suppressor protein by small molecules like Nutlin-3 and RITA (reactivation of p53 and induction of tumor cell apoptosis) is a promising strategy for cancer therapy. The molecular mechanisms involved in the responses to RITA remain enigmatic. Several groups reported the induction of a p53-dependent DNA damage response. Furthermore, the existence of a p53-dependent S-phase checkpoint has been suggested, involving the checkpoint kinase Chk1. We have recently shown synergistic induction of apoptosis by RITA in combination with Nutlin-3, and we observed concomitant Chk2 phosphorylation. Therefore, we investigated whether Chk2 contributes to the cellular responses to RITA. Strikingly, the induction of apoptosis seemed entirely Chk2 dependent. Transcriptional activity of p53 in response to RITA required the presence of Chk2. A partial rescue of apoptosis observed in Noxa knockdown cells emphasized the relevance of p53 transcriptional activity for RITA-induced apoptosis. In addition, we observed an early p53- and Chk2-dependent block of DNA replication upon RITA treatment. Replicating cells seemed more prone to entering RITA-induced apoptosis. Furthermore, the RITA-induced DNA damage response, which was not a secondary effect of apoptosis induction, was strongly attenuated in cells lacking p53 or Chk2. In conclusion, we identified Chk2 as an essential mediator of the cellular responses to RITA

The antecedents and innovation outcomes of firms’ absorptive capacity in global buyer–supplier relationships

This article seeks to address two fundamental questions: (1) Does social capital (SC) embedded in global buyer–supplier (GBS) relationships enhance local firms’ potential absorptive capacity (PAC) and realized absorptive capacity (RAC)? And (2) What are the effects of local firms’ PAC and RAC on their innovation outcomes? Based on survey data collected from 297 Chinese firms engaged in GBS cooperation in China’s Yangtze River Delta region, we test our research hypotheses with the structural equation modelling approach. The empirical findings indicate that both structural and relational SC are important antecedents of PAC and RAC in global buyer–supplier relationships. More specifically, RAC not only improves local suppliers’ new product performance, but also fully mediates the relationship between PAC and new product performance. Our results have two major implications for practicing managers. First, local suppliers in emerging economies need to pay more attention to SC embedded in GBS relationships for it is an important means for them to overcome resource constraints and therefore to improve their new product performance. Second, it is important for managers in local firms to continuously improve their PAC to better assess and assimilate external knowledge, and extend their RAC to upgrade their interpretation and comprehension of commercialization possibilities, which allows for generating synergy of knowledge recombination with existing core competencies

Self-directed learning and absorptive capacity: the mediating role of trust and human capital

This chapter aims to provide a better understanding of how self-directed learning effects absorptive capacity by examining the influence of two mediators: specifically, affective trust in colleagues and human capital development climate. By using a sample of 181 participants from the creative industries sector, a sequential mediation via a three-step causal chain was conducted. This chapter contributes to human resource development and strategic management literature in showing that self-directed learning does not only have a strong effect on the organisational capability, but it also has an impact at the group-level dynamics involving trust and organisational-level climate. These findings show that organisations need to design jobs that allow discretion and autonomy from staff to shape their own learning and to cultivate an environment that recognises and rewards learning

What Fosters Individual-Level Absorptive Capacity in MNCs? : An Extended Motivation-Ability-Opportunity Framework

Absorptive capacity has been marked as one of the most important capabilities of Multinational Corporations for effective management of knowledge. To address calls for research on micro-level origins of the concept, this paper focuses on the determinants of individual-level absorptive capacity. We examine the extent to which individuals' capability to recognize, assimilate and exploit new knowledge from the environment is shaped by different forms of work motivation (i.e., intrinsic and extrinsic), overall ability, exposure to diverse country contexts and personal characteristics. Drawing on and extending the Motivation-Ability-Opportunity framework, we develop and test a set of hypotheses. Using a unique dataset collected from 648 individuals in a multinational corporation, we show that individuals' intrinsic motivation and overall ability are the key antecedents of absorptive capacity. In contrast, extrinsic motivation does not emerge as a significant predictor. We find that past international assignments to distant countries could be detrimental to individuals' absorptive capacity. However, our results suggest that for those individuals who are open to new experiences, assignments to distant countries become useful opportunity for absorptive capacity development. These findings contribute to existing literature by showing effects of alternative types of motivation and underscoring the importance of using selective assignment when considering exposure to diverse country context as a tool for employee capability development