G-quadruplexes in pathogens: a common route to virulence control?

DNA can form several secondary structures besides the classic double helix: one that has received much attention in recent years is the G-quadruplex (G4). This is a stable four-stranded structure formed by the stacking of quartets of guanine bases. Recent work has convincingly shown that G4s can form in vivo as well as in vitro and can affect both replication and transcription of DNA. They also play important roles at G-rich telomeres. Now, a spate of exciting reports has begun to reveal roles for G4 structures in virulence processes in several important microbial pathogens of humans. Interestingly, these come from a range of kingdoms--bacteria and protozoa as well as viruses--and all facilitate immune evasion in different ways. In particular, roles for G4s have been posited in the antigenic variation systems of bacteria and protozoa, as well as in the silencing of at least two major human viruses, human immunodeficiency virus (HIV) and Epstein-Barr virus (EBV). Although antigenic variation and the silencing of latent viruses are quite distinct from one another, both are routes to immune evasion and the maintenance of chronic infections. Thus, highly disparate pathogens can use G4 motifs to control DNA/RNA dynamics in ways that are relevant to common virulence phenotypes. This review explores the evidence for G4 biology in such processes across a range of important human pathogens

Distortional Buckling Formulae for Thin Walled Channel and Z-sections with Return Lips

Cold-formed Channel- and Z-sections subject to both flexure and torsion may undergo distortional buckling where the flange and lip rotate about the flange/web junction. This mode of failure is prevalent in purlin sections when lateral deformation of the section is prevented and when the sections are manufactured from high strength steel. In an attempt to prevent distortional buckling, some manufacturers have added additional return lips to the flange lips to produce complex edge stiffeners. The Australian/New Zealand Standard for Cold-Formed Steel Structures includes design rules for determining the distortional buckling strength of cold-formed beam and column sections. These design rules require the computation of the elastic distortional buckling stress. Appendix D of ASINZS 4600 provides design rules for computing the elastic distortional buckling stress of general channels in compression, simple lipped channels in compression and simple lipped Channel- and Z-sections in bending about an axis perpendicular to the web. The paper describes general formulations for computing the elastic distortional buckling stresses of sections with return lips including those with sloping lips and return lips. The accuracy of the formulations is compared with the results for a large range of section geometries using a finite strip buckling analysis which can be regarded as providing accurate solutions for distortional buckling stress. Explicit expressions are presented in the paper for the flange properties

Assessing the Utility of Restaurant Descriptors and Typologies for Advancing the Body of Knowledge in Restaurant Management

The study begins with a review of existing typologies in the restaurant management literature. Segment labels from three typologies are used as keywords to collect 251 empirical studies from nine relevant academic journals serving the restaurant management discipline. Content analysis of titles, abstracts, and methodology sections reveals inconsistent use of existing typologies and limited use of effective restaurant descriptors. Recommendations are offered to optimize the use of restaurant descriptors so that the content of empirical studies may be more effectively accessed, digested, and compared across, thereby enhancing the communication of advances in the restaurant management body of knowledge

Photoluminescence spectroscopy of bandgap reduction in dilute InNAs alloys

Photoluminescence (PL) has been observed from dilute InNxAs1–x epilayers grown by molecular-beam epitaxy. The PL spectra unambiguously show band gap reduction with increasing N content. The variation of the PL spectra with temperature is indicative of carrier detrapping from localized to extended states as the temperature is increased. The redshift of the free exciton PL peak with increasing N content and temperature is reproduced by the band anticrossing model, implemented via a (5×5) k·p Hamiltonian

Octilinear Force-Directed Layout with Mental Map Preservation for Schematic Diagrams

We present an algorithm for automatically laying out metro map style schematics using a force-directed approach, where we use a localized version of the standard spring embedder forces combined with an octilinear magnetic force. The two types of forces used during layout are naturally conflicting, and the existing method of simply combining these to generate a resultant force does not give satisfactory results. Hence we vary the forces, emphasizing the standard forces in the beginning to produce a well distributed graph, with the octilinear forces becoming prevalent at the end of the layout, to ensure that the key requirement of line angles at intervals of 45? is obtained. Our method is considerably faster than the more commonly used search-based approaches, and we believe the results are superior to the previous force-directed approach. We have further developed this technique to address the issues of dynamic schematic layout. We use a Delaunay triangulation to construct a schematic “frame”, which is used to retain relative node positions and permits full control of the level of mental map preservation. This technique is the first to combine mental map preservation techniques with the additional layout criteria of schematic diagrams. To conclude, we present the results of a study to investigate the relationship between the level of mental map preservation and the user response time and accuracy

TMC Behavior Modeling and Life Prediction Under Multiaxial Stresses

The goal of this program was to manufacture and burst test small diameter SCS-6/Ti-6Al-4V composite rings for use in the design of an advanced titanium matrix composite (TMC) impeller. The Textron Specialty Metals grooved foil-fiber process was successfully used to make high quality TMC rings. A novel spin test arbor with "soft touch" fingers to retain the TMC ring was designed and manufactured. The design of the arbor took into account its use for cyclic experiments as well as ring burst tests. Spin testing of the instrumented ring was performed at ambient, 149C (300F), and 316C (600F) temperatures. Assembly vibration was encountered during spin testing but this was overcome through simple modification of the arbor. A spin-to-burst test was successfully completed at 316C (600F). The rotational speed of the TMC ring at burst was close to that predicted. In addition to the spin test program, a number of SCS-6/Ti-6Al-4V test panels were made. Neat Ti-6Al-4V panels also were made

Office design and health: a systematic review

Aim: To carry out a systematic review of recent research into the effects of workplace design, comparing individual with shared workspaces, on the health of employees. Methods: The research question was "Does workplace design (specifically individual offices compared with shared workspaces) affect the health of workers?" A literature search limited to articles published between 2000 and 2017 was undertaken. A systematic review was carried out, and the findings of the reviewed studies grouped into themes according to the primary outcomes measured in the studies. Results: The literature search identified 15 relevant studies addressing health effects of shared or open-plan offices compared with individual offices. Our systematic review found that, compared with individual offices, shared or open-plan office space is not beneficial to employees' health, with consistent findings of deleterious effects on staff health, wellbeing and productivity. Our findings are also consistent with those of earlier reviews. Conclusion: These findings have public health implications for the New Zealand workforce. Decisions about workplace design should include weighing the short-term financial benefits of open-plan or shared workspaces against the significant harms, including increased sickness absence, lower job satisfaction and productivity, and possible threats to recruitment and retention of staff

Entrances and exits: changing perceptions of primary teaching as a career for men

Original article can be found at: http://www.informaworld.com/smpp/title~content=t713640830~db=all Copyright Informa / Taylor and Francis. DOI: 10.1080/03004430802352087The number of men in teaching has always been small, particularly in early childhood, but those that do come into teaching usually do so for the same reasons as women, namely enjoyment of working with children, of wanting to teach and wanting to make a difference to children's lives. However, in two separate studies, the authors have shown that on beginning teacher training in 1998, and at the point of leaving the profession in 2005, men and women tend to emphasise different concerns. This article will explore those differences and seek possible explanations for how men's views of teaching might be changing over time.Peer reviewe