Children''s return to school after treatment for cancer: study days for teachers

We present a case of benign paradoxical vocal cord adduction' presenting to the emergency department as acute stridor. This patient received direct laryngoscopy at initial presentation documenting inspiratory vocal cord adduction. The syndrome is not well known to emergency physicians and, because it often mimics life-threatening airway compromise, prompt recognition of the benign nature of this syndrome may avert more aggressive airway interventions such as beta agonists, steroids, endotracheal intubation and tracheostomy. Successful treatment has included relaxation, sedatives and speech therapy to abort the acute attack and prevent further recurrence. As direct flexible laryngoscopy is more readily available in the emergency department, goals for the future are more rapid diagnosis and appropriate treatment of this benign syndrome.     

Effects of channel surface finish on blood flow in microfluidic devices

The behaviour of blood flow in relation to microchannel surface roughness has been investigated. Special attention was focused on the techniques used to fabricate the microchannels and on the apparent viscosity of the blood as it flowed through these microchannels. For the experimental comparison of smooth and rough surface channels, each channel was designed to be 10 mm long and rectangular in cross-section with aspect ratios of ≥100:1 for channel heights of 50 and 100 μm. Polycarbonate was used as the material for the device construction. The shims, which created the heights of the channels, were made of polyethylene terephthalate. Surface roughnesses of the channels were varied from R _z of 60 nm to 1.8 μm. Whole horse blood and filtered water were used as the test fluids and differential pressures ranged from 200 to 5,000 Pa. The defibrinated horse blood was treated further to prevent coagulation. The results indicate that a surface roughness above an unknown value lowers the apparent viscosity of blood dramatically due to boundary effects. Furthermore, the roughness seemed to influence both water and whole blood almost equally. A set of design rules for channel fabrication is also presented in accordance with the experiments performed.     

Self-citation: comparison between Radiology,European Radiology and Radiology for 1997–1998

This study investigates the incidence of self-citation (authors citing their own work) for scholarly articles in ten journals published by the American Physiological Society. We analysed authorship and referencing practices of all original research articles published in the first ordinary issue of each journal in both 2000 and 2010, comprising 271 and 212 articles, respectively. Self-citation is common in these journals and represents a total of 17.75% of all citations. Only 9 (1.86%) of the articles analysed did not self-cite. Author position significantly influenced the rate of self-citation with last authors being self-cited significantly more than any other author. This was likely a result of the cumulative nature of scientific research within a specific discipline and the necessary desire to promote ones own work for associated academic benefit. The country in which the work was conducted also influenced the rate of self-citation, with last authors based in North America self-citing more than last authors from Asian countries. A comparison of self-citation rates between decades (2000 and 2010) revealed an increase in the number of authors and number of citations per article between 2000 and 2010, however the mean percentage of self-cited articles did not differ between the years. Finally, there were no differences in the percentage of self-citation between the different journals analysed.     

Previous Influenza Infection Exacerbates Allergen Specific Response and Impairs Airway Barrier Integrity in Pre-Sensitized Mice

In this study we assessed the effects of antigen exposure in mice pre-sensitized with allergen following viral infection on changes in lung function, cellular responses and tight junction expression. Female BALB/c mice were sensitized to ovalbumin and infected with influenza A before receiving a second ovalbumin sensitization and challenge with saline, ovalbumin (OVA) or house dust mite (HDM). Fifteen days post-infection, bronchoalveolar inflammation, serum antibodies, responsiveness to methacholine and barrier integrity were assessed. There was no effect of infection alone on bronchoalveolar lavage cellular inflammation 15 days post-infection; however, OVA or HDM challenge resulted in increased bronchoalveolar inflammation dominated by eosinophils/neutrophils or neutrophils, respectively. Previously infected mice had higher serum OVA-specific IgE compared with uninfected mice. Mice previously infected, sensitized and challenged with OVA were most responsive to methacholine with respect to airway resistance, while HDM challenge caused significant increases in both tissue damping and tissue elastance regardless of previous infection status. Previous influenza infection was associated with decreased claudin-1 expression in all groups and decreased occludin expression in OVA or HDM-challenged mice. This study demonstrates the importance of the respiratory epithelium in pre-sensitized individuals, where influenza-infection-induced barrier disruption resulted in increased systemic OVA sensitization and downstream effects on lung function.     

Time Lapse Kinematography for Traffic Research

Time Lapse Kinematography is being increasingly used by research workers in the field of traffic engineering to define quantitatively the microscopic and macroscopic behaviour of traffic on the open highway and at channelized and signal-controlled intersections. The information obtained is being used to confirm and extend traffic flow theories and to provide the necessary field data to enable traffic situations to be realistically simulated on the electronic digital computor. The success of the method depends to a large extent on the reliability of the equipment used and the ease with which the analysis work can be carried out, since this part of the work can be extremely tedious. In this paper the authors describe in detail the equipment they have developed and used with success. The electronic time pulse unit which operates a standard Vinten Mark 3 16mm cine camera is portable and is powered by 12 volt lead acid accumulators and nickel cadmium button cells. The unit which incorporates two multivibrator circuits, produces pulses of the required magnitude and duration to operate the camera at set speeds of 1, 2, or 4 p.p.s. or a variable rate between I p.p.s. and I pulse per eight seconds with a maximum error in the order of 0.7 per cent. The complete circuit diagram is given. The analysis unit incorporates a Specto Mk. 2 analysis projector with a 32×23 in. rear projection screen. The projected image is reflected through 180° on to the screen, thus enabling the projector to be placed adjacent to the viewing position so that the operator can readily operate the projector and abstract data from the screen image. An accurate measuring device with 2 fiducial marks extending the full depth of the screen is incorporated. The full text of this paper is published in The Photographic Journal. 106, 311 (1966).     

Engineering mathematics: the crisis continues

This article raises the main points of discussion relevant to the gradual dilution and weakening of university mathematics as an integral part of the engineering degree, and attempts to present an assessment of the situation in the light of persistent problems facing engineering mathematics and its changing nature