High-pressure study of X-ray diffuse scattering in ferroelectric perovskites

We present a high-pressure x-ray diffuse scattering study of the ABO$_3$ ferroelectric perovskites BaTiO_3 and KNbO_3. The well-known diffuse lines are observed in all the phases studied. In KNbO_3, we show that the lines are present up to 21.8 GPa, with constant width and a slightly decreasing intensity. At variance, the intensity of the diffuse lines observed in the cubic phase of BaTiO_3 linearly decreases to zero at $\sim 11$ GPa. These results are discussed with respect to x-ray absorption measurements, which leads to the conclusion that the diffuse lines are only observed when the B atom is off the center of the oxygen tetrahedron. The role of such disorder on the ferroelectric instability of perovskites is discussed.Comment: 4 pages, Accepted in PR

Conformational flexibility of RNA polymerase III during transcriptional elongation

RNA polymerase (Pol) III is responsible for the transcription of genes encoding small RNAs, including tRNA, 5S rRNA and U6 RNA. Here, we report the electron cryomicroscopy structures of yeast Pol III at 9.9 Å resolution and its elongation complex at 16.5 Å resolution. Particle sub-classification reveals prominent EM densities for the two Pol III-specific subcomplexes, C31/C82/C34 and C37/C53, that can be interpreted using homology models. While the winged-helix-containing C31/C82/C34 subcomplex initiates transcription from one side of the DNA-binding cleft, the C37/C53 subcomplex accesses the transcription bubble from the opposite side of this cleft. The transcribing Pol III enzyme structure not only shows the complete incoming DNA duplex, but also reveals the exit path of newly synthesized RNA. During transcriptional elongation, the Pol III-specific subcomplexes tightly enclose the incoming DNA duplex, which likely increases processivity and provides structural insights into the conformational switch between Pol III-mediated initiation and elongation

Thinking about a limited future enhances the positivity of younger and older adults’ recall: support for socioemotional selectivity theory

Compared with younger adults, older adults have a relative preference to attend to and remember positive over negative information. This is known as the “positivity effect,” and researchers have typically evoked socioemotional selectivity theory to explain it. According to socioemotional selectivity theory, as people get older they begin to perceive their time left in life as more limited. These reduced time horizons prompt older adults to prioritize achieving emotional gratification and thus exhibit increased positivity in attention and recall. Although this is the most commonly cited explanation of the positivity effect, there is currently a lack of clear experimental evidence demonstrating a link between time horizons and positivity. The goal of the current research was to address this issue. In two separate experiments, we asked participants to complete a writing activity, which directed them to think of time as being either limited or expansive (Experiments 1 and 2) or did not orient them to think about time in a particular manner (Experiment 2). Participants were then shown a series of emotional pictures, which they subsequently tried to recall. Results from both studies showed that regardless of chronological age, thinking about a limited future enhanced the relative positivity of participants’ recall. Furthermore, the results of Experiment 2 showed that this effect was not driven by changes in mood. Thus, the fact that older adults’ recall is typically more positive than younger adults’ recall may index naturally shifting time horizons and goals with age

Corporate reputation past and future: a review and integration of existing literature and a framework for future research

The concept of corporate reputation is steadily growing in interest among management researchers and practitioners. In this article, we trace key milestones in the development of reputation literature over the past six decades to suggest important research gaps as well as to provide contextual background for a subsequent integration of approaches and future outlook. In particular we explore the need for better categorised outcomes; a wider range of causes; and a deeper understanding of contingencies and moderators to advance the field beyond its current state while also taking account of developments in the macro business environment. The article concludes by presenting a novel reputation framework that integrates insights from reputation theory and studies, outlines gaps in knowledge and offers directions for future research

Synthesising Corporate Responsibility on Organisational and Societal Levels of Analysis: An Integrative Perspective

This article develops an integrative perspective on corporate responsibility by synthesising competing perspectives on the responsibility of the corporation at the organisational and societal levels of analysis. We review three major corporate responsibility perspectives, which we refer to as economic, critical, and politico-ethical. We analyse the major potential uses and pitfalls of the perspectives, and integrate the debate on these two levels. Our synthesis concludes that when a society has a robust division of moral labour in place, the responsibility of a corporation may be economic (as suggested under the economic perspective) without jeopardising democracy and sustainability (as reported under the critical perspective). Moreover, the economic role of corporations neither signifies the absence of deliberative democratic mechanisms nor business practices extending beyond compliance (as called for under the politico-ethical perspective). The study underscores the value of integrating different perspectives and multiple levels of analysis to present comprehensive descriptions and prescriptions of the responsibility phenomenon