This paper describes an experimental investigation intothe effect of miniature vortex generators (VGs) onthe longitudinal aerodynamic characteristics of ahighly-swept wing with drooped leading edges. Theexperiments were performed in a low-speed windtunnelon a wing of the same delta planform as that used ina previous study. The latter wing was of fixedcamber, while the subject of the present study was awing with three different leading edge droop angles.The maximum reduction in drag due to the VGs wasfound to be about half that for the fixed-camberwing. This is reconciled with the differentbehaviour of the flow on the upper surface for thetwo types of wing. Without control, the drag of thevariable-droop wings is much lower than that of thefixed-camber wing. As a result, with control, thevariable droop wings have lower drag than that ofthe fixed-camber wing. Compared to that of thevariable-droop wings without control, thefixed-camber wing, with control, has lowerlift-dependent drag for lift coefficients between0·4 and 0·7. However, at higher lift coefficients,the reverse applies.

By conducting a case-control study in two university hospitals, we explored the association between modifiable risk behaviours and diarrhoea. Children aged <5 years attending outpatient clinics for diarrhoea were matched by age and sex with controls. Data were collected on family demographics, socioeconomic indicators, and risk behaviour practices. Two rectal swabs and a stool specimen were collected from cases and controls. Samples were cultured for bacterial pathogens using standard techniques and tested by ELISA to detect rotavirus and Cryptosporidium spp. Four hundred cases and controls were enrolled between 2007 and 2009. The strongest independent risk factors for diarrhoea were: presence of another household member with diarrhoea [matched odds ratio (mOR) 4·9, 95% CI 2·8–8·4] in the week preceding the survey, introduction to a new kind of food (mOR 3, 95% CI 1·7–5·4), and the child being cared for outside home (mOR 2·6, 95% CI 1·3–5·2). While these risk factors are not identifiable, in some age groups more easily modifiable risk factors were identified including: having no soap for handwashing (mOR 6·3, 95% CI 1·2–33·9) for children aged 7–12 months, and pacifier use (mOR 1·9, 95% CI 1·0–3·5) in children aged 0–6 months. In total, the findings of this study suggest that community-based interventions to improve practices related to sanitation and hygiene, handwashing and food could be utilized to reduce the burden of diarrhoea in Egyptian children aged <5 years.

Shigella is an important bacterial cause of infectious diarrhoea globally. The Shigella human challenge model has been used since 1946 for a variety of objectives including understanding disease pathogenesis, human immune responses and allowing for an early assessment of vaccine efficacy. A systematic review of the literature regarding experimental shigellosis in human subjects was conducted. Summative estimates were calculated by strain and dose. While a total of 19 studies evaluating nine strains at doses ranging from 10 to 1 × 1010 colony-forming units were identified, most studies utilized the S. sonnei strain 53G and the S. flexneri strain 2457T. Inoculum solution and pre-inoculation buffering has varied over time although diarrhoea attack rates do not appear to increase above 75–80%, and dysentery rates remain fairly constant, highlighting the need for additional dose-ranging studies. Expansion of the model to include additional strains from different serotypes will elucidate serotype and strain-specific outcome variability.

At the summit of the Antarctic plateau, Dome A offers an intriguing location for future large scale optical astronomical observatories. The Gattini Dome A project was created to measure the optical sky brightness and large area cloud cover of the winter-time sky above this high altitude Antarctic site. The wide field camera and multi-filter system was installed on the PLATO instrument module as part of the Chinese-led traverse to Dome A in January 2008. This automated wide field camera consists of an Apogee U4000 interline CCD coupled to a Nikon fisheye lens enclosed in a heated container with glass window. The system contains a filter mechanism providing a suite of standard astronomical photometric filters (Bessell B, V, R) and a long-pass red filter for the detection and monitoring of airglow emission. The system operated continuously throughout the 2009, and 2011 winter seasons and part-way through the 2010 season, recording long exposure images sequentially for each filter. We have in hand one complete winter-time dataset (2009) returned via a manned traverse. We present here the first measurements of sky brightness in the photometric V band, cloud cover statistics measured so far and an estimate of the extinction.

Despite the absence of artificial light pollution at Antarctic plateau sites such as Dome A, other factors such as airglow, aurorae and extended periods of twilight have the potential to adversely affect optical observations. We present a statistical analysis of the airglow and aurorae at Dome A using spectroscopic data from Nigel, an optical/near-IR spectrometer operating in the 300–850 nm range. The median auroral contribution to the B, V and R photometric bands is found to be 22.9, 23.4 and 23.0 mag arcsec−2 respectively. We are also able to quantify the amount of annual dark time available as a function of wavelength; on average twilight ends when the Sun reaches a zenith distance of 102.6°.

PLATO is a 6 tonne completely self-contained robotic observatory that provides its own heat, electricity, and satellite communications. It was deployed to Dome A in Antarctica in January 2008 by the Chinese expedition team, and is now in its second year of operation. PLATO is operating four 14.5cm optical telescopes with 1k × 1k CCDs, a wide-field sky camera with a 2k × 2k CCD and Sloan g, r, i filters, a fibre-fed spectrograph to measure the UV to near-IR sky spectrum, a 0.2m terahertz telescope, two sonic radars giving 1m resolution data on the boundary layer to a height of 180m, a 15m tower, meteorological sensors, and 8 web cameras. Beginning in 2010/11 PLATO will be upgraded to support a Multi Aperture Scintillation Sensor and three AST3 0.5m schmidt telescopes, with 10k × 10 CCDs and 100TB/annum data requirements.

The Protocol on Environmental Protection to the Antarctic Treaty requires that past and present work sites be cleaned up unless removal would result in greater adverse environmental impact than leaving the contaminant in its existing location. In the early 1990s Australia began the documentation of contaminated sites associated with its research stations, which resulted in an extensive record of contamination at abandoned stations and waste-disposal sites. Currently the technical capability to remediate these sites does not exist because of environmental challenges that are unique to the cold regions. Investigations indicate that clean-up operations in the past have proceeded without adequate precautions and without effective monitoring. To address these problems, three research priorities have been identified to assist meeting international and national obligations to clean up these sites. They are: understanding contaminant mobilisation processes; development of ecological risk assessment for use in monitoring and setting priorities; and development of clean-up and remediation procedures. This study provides sufficient information to guide the completion of a clean-up at Casey Station and to indicate how other similar sites should be managed. The next stage is to develop the theory into an operational plan to include detailed protocols for clean-up, monitoring, site remediation, and management of the waste stream from site to final repository. To achieve this, the Australian Antarctic Division has established a contaminated sites taskforce to facilitate the transition from research and development of techniques to implementation of suitable clean-up options.

Understanding the epidemiology of current health threats to deployed U.S. troops is important for medical assessment and planning. As part of a 2004 study among U.S. military personnel deployed to Al Asad Air Base, in the western Anbar Province of Iraq, over 500 subjects were enrolled, provided a blood specimen, and completed a questionnaire regarding history of febrile illness during this deployment (average ∼4 months in country). This mid-deployment serum was compared to pre-deployment samples (collected ∼3 months prior to deployment) and evaluated for seroconversion to a select panel of regional arboviral pathogens. At least one episode of febrile illness was reported in 84/504 (17%) of the troops surveyed. Seroconversion was documented in nine (2%) of deployed forces tested, with no association to febrile illness. Self-reported febrile illness was uncommon although often debilitating, and the risk of illness due to arbovirus infections was relatively low.

The Gimbal Top distribution system for blast furnaces was introducedin October 2006. With this solution any burden profile can begenerated by directing the feed material to any point on the furnacestock line. This is made possible by innovative design features whichallow the chute angle and position to be continuously adjustedduring material discharging. The described Gimbal Top Distributor isfit for the high-temperature and high-pressure environment of ironmakingplants.

Ninety-seven isolates of Shigella flexneri from children seeking medical care from three sites in Egypt were characterized. Overall, 46·4% of children (median age 17 months) were febrile or reported blood in their stools, 25·8% were dehydrated and 16·5% were admitted to hospital. Serotypes 2a (37·1%), 1b (18·6%), 1c (17·5%), and 6 (15·5%) comprised over 88·7% of the total isolates. We observed marked resistance to ampicillin (87·6%), tetracycline (84·5%) and trimethoprim–sulfamethoxazole (63·9%). Pulsed-field electrophoresis grouped the majority of isolates within a serotype together, separately from isolates of an alternative serotype. The set gene was present in all serogroup 2a isolates, however, the sen gene was detected in every isolate. Our results show S. flexneri 1c has emerged as a dominant S. flexneri serotype in Egypt. Development and application of a Shigella vaccine should consider the diversity of Shigella serotypes within a geographical region prior to administration.

A field experiment investigating the effect of oil contamination on benthic microbial communities was conducted near Casey Station, East Antarctica. Defaunated sediment was treated with a mixture of Special Antarctic Blend diesel and lubricating oil and deployed in three different bays for eleven weeks. A molecular fingerprinting technique, denaturing gradient gel electrophoresis (DGGE), was used to investigate the microbial community structure. The variation between replicate samples within treatment groups indicates that the benthic microbial populations are very diverse and evenly distributed. Comparisons to determine the significance of both deployment location and hydrocarbon treatment showed that the greatest effect was from a combination of location and treatment. Detailed analysis suggests that subtle differences may be obscured by variability introduced by PCR and gel stages in DGGE, undermining this experimental approach. It is concluded that both location and hydrocarbon contamination influenced the development of the microbial communities but that the effect of hydrocarbon treatment varied with location. This has important implications for the design of future experiments on the effect of hydrocarbons on benthic communities, especially if it is intended to generalize the conclusions drawn from site specific studies.

The ways by which contaminants in freezing ground disperse and interact with associated ecosystems is a new and challenging field of applied research that is crucial to effective assessment, monitoring, and remediation in cold regions. Three key issues have been identified as needing urgent research and development. The first concerns the development and application of meaningful environmental guidelines for cold regions. This usually means that contaminants in freezing ground per se need to be considered in their broadest context by also addressing associated ecosystems, such as the receiving marine environment. The second issue concerns developing best practice for bioremediation of seasonally frozen soils. Of particular concern are the risks, benefits, and costs of using so-called bioproducts, which may not offer substantial improvements over biostimulation of indigenous cold-adapted organisms. The third issue concerns the need for assessment and monitoring protocols and cost-effective analytical tools. In this respect the potential use of field portable instruments deserves careful consideration and on-site testing. Taken together, development of these issues during the coming years will be crucial if the science behind managing contaminants in freezing ground is to catch up with the knowledge that underpins the remediation industry elsewhere.