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

An Efficient System for Heterologous Expression of Secondary Metabolite Genes in Aspergillus nidulans

This document is the Accepted Manuscript version of a Published Work that appeared in final form in the Journal of the American Chemical Society, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://doi.org/10.1021/ja401945a.Fungal secondary metabolites (SMs) are an important source of medically valuable compounds. Genome projects have revealed that fungi have many SM biosynthetic gene clusters that are not normally expressed. To access these potentially valuable, cryptic clusters, we have developed a heterologous expression system in Aspergillus nidulans. We have developed an efficient system for amplifying genes from a target fungus, placing them under control of a regulatable promoter, transferring them into A. nidulans and expressing them. We have validated this system by expressing non-reducing polyketide synthases of Aspergillus terreus and additional genes required for compound production and release. We have obtained compound production and release from six of these NR-PKSs and have identified the products. To demonstrate that the procedure allows transfer and expression of entire secondary metabolite biosynthetic pathways, we have expressed all the genes of a silent A. terreus cluster and demonstrate that it produces asperfuranone. Further, by expressing the genes of this pathway in various combinations, we have clarified the asperfuranone biosynthetic pathway. We have also developed procedures for deleting entire A. nidulans SM clusters. This allows us to remove clusters that might interfere with analyses of heterologously expressed genes and to eliminate unwanted toxins

Self-assembly in solution of a reversible comb-shaped supramolecular polymer

We report a single step synthesis of a polyisobutene with a bis-urea moiety in the middle of the chain. In low polarity solvents, this polymer self-assembles by hydrogen bonding to form a combshaped polymer with a central hydrogen bonded backbone and polyisobutene arms. The comb backbone can be reversibly broken, and consequently, its length can be tuned by changing the solvent, the concentration or the temperature. Moreover, we have proved that the bulkiness of the side-chains have a strong influence on both the self-assembly pattern and the length of the backbone. Finally, the density of arms can be reduced, by simply mixing with a low molar mass bis-urea

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

Hybrid cloud computing architecture based on open source technology

The advance of technologies such as distributed computing, Internetand grid computing, have enabled Cloud Computing to become part of a new model of computing and business. Cloud Computing is transforming the traditional ways in which companies use and acquire Information Technology (IT) resources. After an initial boom in Public Cloud, companies begun to mount hybrid Clouds that offer the advantages of Cloud Computing in addition to the privacy of data they consider strategic. A hybrid Cloud solution allows the integration of both systems. Leading companies in cloud solutions have understood this evolution and begun to offer hybrid solutions. Moreover, many of these companies are taking the next step by offering solutions based on open source standards that allow a high degree of interoperability and portability

Diagnosis and management of hyponatraemia: AGREEing the guidelines

Hyponatraemia is a common electrolyte disorder associated with significant complications and controversies regarding its optimal management. Clinical practice guidelines and consensus statements have attempted to provide clinicians with evidence-based diagnostic and treatment strategies for hyponatraemia. Recently published guidance documents differ in their methods employed to review the quality of available evidence. Nagler et al. used the Appraisal of Guideline for Research and Evaluation (AGREE II) instrument in a systematic review of guidelines and consensus statements for the diagnosis and management of hyponatraemia. Nagler and colleagues highlighted the variability in methodological rigour applied to guideline development and inconsistencies between publications in relation to management of hyponatraemia (including the recommended rate of correction of a low serum sodium concentration). These differences could cause confusion for practising physicians managing patients with hyponatraemia.</p

Rabdomiossarcoma de vesícula urinária em cão da Serra da Estrela adulto jovem. Relato de caso

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Promoting dental care to children using traditional and interactive media following threat appeals

In recent years, computer games have become an important part of children’s lives. Gaming is not only one of their favorite pastime activities, but games are also increasingly used by marketers in an attempt to influence children’s purchase behavior. Today, almost every food and beverage brand targeting children has an advergame on its website. Advergames are “computer games specifically created to function as advertisements to promote brands”, containing brand identifiers such as logos and brand characters (Kretchmer, 2005: 7). Games can also be powerful learning tools. Several authors (e.g., Gee, 2003; Prensky, 2001) argue that computer games can be more enjoyable, more interesting and thus more effective than traditional learning modes to increase children’s knowledge. Empirical studies that evaluated the impact of the use of games within disciplines such as mathematics, science, language, geography and computer science show positive outcomes in terms of learning effectiveness in relation to curricular objectives (e.g., Papastergiou, 2009; Rosas et al., 2003). However, these authors mainly focus on the learning ability of games rather than their persuasive impact for social marketing purposes. In the area of health education, playing computer games has often been seen with skepticism (e.g., Bale, 1994; Funk and Buchman, 1995)