Shock tunnel studies of scramjet phenomena

Commissioning of the new T4 shock tunnel at the University of Queensland implied that it was no longer necessary to focus the work of the research group about an annual test series conducted in the T3 shock tunnel in Canberra. Therefore, it has been possible to organize a group for work to proceed along lines such that particular personnel are associated with particular project areas. The format of this report consists of a series of reports on specific project areas, with a brief general introduction commenting on each report. The introduction is structured by project areas, with the title of the relevant report stated under the project area heading. The reports themselves follow in the order of the project area headings

Pharmacotherapy Challenges of Fontan‐Associated Plastic Bronchitis: A Rare Pediatric Disease

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99662/1/phar1290.pd

The influence of trees, shrubs, and grasses on microclimate, soil carbon, nitrogen, and CO2 efflux:Potential implications of shrub encroachment for Kalahari rangelands

Shrub encroachment is a well-documented phenomenon affecting many of the world's drylands. The alteration of vegetation structure and species composition can lead to changes in local microclimate and soil properties which in turn affect carbon cycling. The objectives of this paper were to quantify differences in air temperatures, soil carbon, nitrogen, and CO2 efflux under trees (Vachellia erioloba), shrubs (Grewia flava), annual and perennial grasses (Schmidtia kalahariensis and Eragrostis lehmanniana) collected over three seasons at a site in Kgalagadi District, Botswana, in order to determine the vegetation-soil feedback mechanism affecting the carbon cycle. Air temperatures were logged continuously and soil CO2 efflux was determined throughout the day and evening using closed respiration chambers and an infrared gas analyser. There were significant differences in soil carbon, total nitrogen, CO2 efflux, light and temperatures beneath the canopies of trees, shrubs and grasses. Daytime air temperatures beneath shrubs and trees were cooler compared to grass sites, particularly in summer months. Night time air temperatures under shrubs and trees were, however, warmer than at the grass sites. There was also significantly more soil carbon, nitrogen and CO2 efflux under shrubs and trees compared to grasses. Whilst the differences observed in soils and microclimate may reinforce the competitive dominance of shrubs and present challenges to strategies designed to manage encroachment they should not be viewed as entirely negative. Our findings highlight some of the dichotomies and challenges to be addressed before interventions aiming to bring about more sustainable land management can be implementedpublishersversionPeer reviewe

Pathology, infectious agents and horse- and management-level risk factors associated with signs of respiratory disease in Ethiopian working horses.

BACKGROUND:Respiratory disease is a common cause for presentation of working horses to clinics in Ethiopia and a priority concern for owners. OBJECTIVES:Identify risk factors for and association of pathogens with respiratory signs in working horses. Study design Unmatched case-control study. METHODS:Cases were those animals recently coughing (last 7 days) or observed with coughing, nasal discharge or altered respiration at the time of examination. A physical exam and respiratory endoscopy were performed including a tracheal wash sample to detect the presence of pathogens and serology performed on blood. An owner questionnaire was administered. Risk factors were determined using multivariable logistic regression. RESULTS:Data on 108 cases and 93 unmatched control horses were obtained. Case horses often had underlying lower airway pathology and were significantly more likely to have S zooepidemicus detected (OR 12.4, 95% CI 3.6-42.4). There was no evidence of a major role for viral respiratory pathogens. Risk factors included completion of strenuous work (OR 2.7, 95% CI 1.2-6.3), drinking from stagnant water sources (OR 2.3, 95% CI 1.0-5.2) or being housed on a cobbled floor (OR 2.0, 95% CI 1.1-3.8). There were increased odds of respiratory disease in young and old horses in this population. Main limitations Samples for pathogen detection and cytology were only taken from the trachea. CONCLUSION:S zooepidemicus, a common commensal, may play a role in clinical respiratory disease in this population

Point-of-Care Virologic Testing to Improve Outcomes of HIV-Infected Children in Zambia: A Clinical Trial Protocol

In the absence of early infant diagnosis (EID) and immediate antiretroviral therapy (ART), some 50% of untreated HIV-infected infants die before age 2. Conventional EID requires sophisticated instruments that are typically placed in centralized or reference laboratories. In low-resource settings, centralized systems often lead to result turnaround times of several months, long delays in diagnosis, and adverse outcomes for HIV-infected children. Our clinical trial tests the effectiveness of a new point-of-care (POC) diagnostic technology to identify HIV-infected infants and start providing them life-saving ART as soon as possible

Mock observations with the Millennium Simulation: cosmological downsizing and intermediate-redshift observations

Only by incorporating various forms of feedback can theories of galaxy formation reproduce the present-day luminosity function of galaxies. It has also been argued that such feedback processes might explain the counterintuitive behaviour of 'downsizing' witnessed since redshifts z ≃ 1–2. To examine this question, observations spanning 0.4 < z < 1.4 from the Deep Extragalactic Evolutionary Probe (DEEP)2/Palomar survey are compared with a suite of equivalent mock observations derived from the Millennium Simulation, populated with galaxies using the galform code. Although the model successfully reproduces the observed total mass function and the general trend of 'downsizing', it fails to accurately reproduce the colour distribution and type-dependent mass functions at all redshifts probed. This failure is shared by other semi-analytical models which collectively appear to 'over-quench' star formation in intermediate-mass systems. These mock lightcones are also a valuable tool for investigating the reliability of the observational results in terms of cosmic variance. Using variance estimates derived from the lightcones, we confirm the significance of the decline since z ∼ 1 in the observed number density of massive blue galaxies which, we argue, provides the bulk of the associated growth in the red sequence. We also assess the limitations arising from cosmic variance in terms of our ability to observe mass-dependent growth since z ∼ 1

Peer mentorship and positive effects on student mentor and mentee retention and academic success

This study examined how the introduction of peer mentorship in an undergraduate health and social welfare programme at a large northern university affected student learning. Using an ethnographic case study approach, the study draws upon data collected from a small group of mentors and their mentees over a period of one academic year using interviews, reflective journals, assessment and course evaluation data. Analysis of the data collected identified a number of key findings: peer mentorship improves assessment performance for both mentee and mentor; reduces stress and anxiety, enhances participation and engagement in the academic community, and adds value to student outcomes

Numerical investigation of laboratory tested cross-flow tidal turbines and Reynolds number scaling

The cross-flow, or vertical axis tidal turbine, is a prominent configuration of marine renewable energy device aimed at converting tidal currents into electrical energy. This paper highlights the hydrodynamic limitations of laboratory testing such devices and uses numerical simulation to explore the effect of device scaling. Using a 2D Reynolds-Averaged Navier-Stokes (RANS) numerical approach, a single turbine blade is initially modelled and validated against published data. The resultant numerical model is then expanded to emulate an experimental cross-flow tidal turbine designed and tested by the University of Oxford. The simulated turbine achieves a close quantitative match for coefficients of power, torque and thrust, forming the basis of a study exploring the effects of Reynolds number scaling in three alternative operating conditions. It is discovered that the coefficient of power (C&lt;inf&gt;P&lt;/inf&gt;) increases with Re- without a ubiquitous correlation until an Re- of ~350,000. Above this Re- the C&lt;inf&gt;P&lt;/inf&gt; values for all three operation conditions become both proportional and predictable. The study represents a significant contribution to understanding the application of detailed numerical modelling techniques to cross-flow tidal turbines. The findings, with regard to scaling from laboratory data, could reduce uncertainty and development costs for new and existing devices.</p

Development and evaluation of a molecular diagnostic method to rapidly detect Histoplasma capsulatum var. farciminosum, the causative agent of epizootic lymphangitis, in equine clinical samples.

Histoplasma capsulatum var. farciminosum (HCF), the causative agent of epizootic lymphangitis (EZL), is endemic in parts of Africa. Diagnosis based on clinical signs and microscopy lacks specificity, and is a barrier to further understanding this neglected disease. Here, a nested PCR method targeting the ITS region of the rRNA operon was validated for application to equine clinical samples. Twenty-nine horses with signs of EZL, from different climatic regions of Ethiopia, were clinically examined. Blood samples and aspirates of pus from cutaneous nodules were taken, along with blood from a further 20 horses with no cutaneous EZL lesions. HCF was confirmed in DNA extracts of pus and blood samples from 25 and 17 horses, respectively, of the 29 suspected EZL cases. Positive PCR results were also obtained from heat-inactivated pus (24 horses) and blood (23 horses) spotted onto Whatman FTA cards. Two positives were obtained among blood samples from 20 horses that did not exhibit clinical signs of EZL. These are the first reports of the direct detection of HCF in equine blood, and at high frequency amongst horses exhibiting cutaneous lesions. The nested PCR outperformed conventional microscopic diagnosis, as characteristic yeast cells could only be observed in 14 pus samples. HCF DNA was confirmed by sequencing the cloned PCR products, and while alignment of the ITS amplicons showed very little sequence variation, there was preliminary SNP-based evidence for the existence of two subgroups of HCF. This molecular diagnostic method now permits investigation of the epidemiology of EZL