Stable Branched Electron Flow

The pattern of branched electron flow revealed by scanning gate microscopy shows the distribution of ballistic electron trajectories. The details of the pattern are determined by the correlated potential of remote dopants with an amplitude far below the Fermi energy. We find that the pattern persists even if the electron density is significantly reduced such that the change in Fermi energy exceeds the background potential amplitude. The branch pattern is robust against changes in charge carrier density, but not against changes in the background potential caused by additional illumination of the sample.Comment: Accepted for publication in New Journal of Physic

Prestige and content biases together shape the cultural transmission of narratives

Context-based cultural transmission biases such as prestige are thought to have been a primary driver in shaping the dynamics of human cultural evolution. However, few empirical studies have measured the importance of prestige relative to other effects, such as the content biases present within transmitted information. Here, we report the findings of an experimental transmission study designed to compare the simultaneous effects of a high- or low-prestige model with the presence of content containing social, survival, emotional, moral, rational, or counterintuitive information. Results from multimodel inference reveal that prestige is a significant factor in determining salience and recall, but that several content biases, specifically social, survival, negative emotional, and biological counterintuitive information, are significantly more influential. Further, we find evidence that prestige serves as a conditional learning strategy when no content cues are available. Our results demonstrate that content biases serve a vital and underappreciated role in cultural transmissionIntroduction Methods - Experimental protocol - Participants - Story production - Recordings - Data coding and transcription - Data analysis - Ethics statement Results - Sample demographics - Participants showed preferential recall of biased information - Content biases were more influential than prestige bias - Transmission biases explain little variance in recall Discussion - Prestige bias has a minor effect on transmission - Prestige is unconsciously employed as a secondary bias - Content biases have distinct effects - Narrative structural features may aid transmission - Implications for the understanding of transmissio

Molecular genetic analysis reveals that a nonribosomal peptide synthetase-like (NRPS-like) gene in Aspergillus nidulans is responsible for microperfuranone biosynthesis

Genome sequencing of Aspergillus species including Aspergillus nidulans has revealed that there are far more secondary metabolite biosynthetic gene clusters than secondary metabolites isolated from these organisms. This implies that these organisms can produce additional secondary metabolites, which have not yet been elucidated. The A. nidulans genome contains 12 nonribosomal peptide synthetase (NRPS), one hybrid polyketide synthase/NRPS, and 14 NRPS-like genes. The only NRPS-like gene in A. nidulans with a known product is tdiA, which is involved in terrequinone A biosynthesis. To attempt to identify the products of these NRPS-like genes, we replaced the native promoters of the NRPS-like genes with the inducible alcohol dehydrogenase (alcA) promoter. Our results demonstrated that induction of the single NRPS-like gene AN3396.4 led to the enhanced production of microperfuranone. Furthermore, heterologous expression of AN3396.4 in Aspergillus niger confirmed that only one NRPS-like gene, AN3396.4, is necessary for the production of microperfuranone

One job, one deal...or not: do generations respond differently to psychological contract fulfillment?

This paper investigates generational differences in the relations between psychological contract fulfillment and work attitudes. Data were collected from a sample of 909 employees in the Dutch service sector. Structural equation modeling analyses were used to test the moderating effects of generational differences on the influence of psychological contract fulfillment on affective commitment and turnover intention. The relationship between psychological contract fulfillment and these work outcomes was moderated by generational differences. Furthermore, results indicate that different generations respond differently to different aspects of psychological contract fulfillment, such as career development, job content, organizational policies, social atmosphere and rewards. The study provides evidence that generational differences impact the reciprocal relationship between employer and employee. Results from this study suggest that Baby Boomers and Generation X may be more motivated by social atmosphere, whereas Generation Y may be more motivated by job content and career development. Fair organizational policies are particularly motivating to Generation X, and providing rewards, though more important to Generation Y, seem mostly unrelated to work outcomes. This article is the first to study the moderation of generational differences in the relationships between psychological contract fulfillment and work outcomes

Molecular genetic characterization of a cluster in A. terreus for biosynthesis of the meroterpenoid terretonin

Meroterpenoids are natural products produced from polyketide and terpenoid precursors. A gene targeting system for A. terreus NIH2624 was developed and a gene cluster for terretonin biosynthesis was characterized. The intermediates and shunt products were isolated from the mutant strains and a pathway for terretonin biosynthesis is proposed. Analysis of two meroterpenoid pathways corresponding to terretonin in A. terreus and austinol in A. nidulans reveals that they are closely related evolutionarily