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The morphology of englacial drainage networks and their temporal evolution are poorly characterised, particularly within cold ice masses. At present, direct observations of englacial channels are restricted in both spatial and temporal resolution. Through novel use of a terrestrial laser scanning (TLS) system, the interior geometry of an englacial channel in Austre Brøggerbreen, Svalbard, was reconstructed and mapped. Twenty-eight laser scan surveys were conducted in March 2016, capturing the glacier surface around a moulin entrance and the uppermost 122 m reach of the adjoining conduit. The resulting point clouds provide detailed 3-D visualisation of the channel with point accuracy of 6.54 mm, despite low (<60%) overall laser returns as a result of the physical and optical properties of the clean ice, snow, hoar frost and sediment surfaces forming the conduit interior. These point clouds are used to map the conduit morphology, enabling extraction of millimetre-to-centimetre scale geometric measurements. The conduit meanders at a depth of 48 m, with a sinuosity of 2.7, exhibiting teardrop shaped cross-section morphology. This improvement upon traditional surveying techniques demonstrates the potential of TLS as an investigative tool to elucidate the nature of glacier hydrological networks, through reconstruction of channel geometry and wall composition. [ABSTRACT FROM PUBLISHER]

Longitudinal ice-surface structures in the Antarctic Ice Sheet can be traced continuously down-ice for distances of up to 1200 km. A map of the distribution of ~3600 of these features, compiled from satellite images, shows that they mirror the location of fast-flowing glaciers and ice streams that are dominated by basal sliding rates above tens of metres per annum and are strongly guided by subglacial topography. Longitudinal ice-surface structures dominate regions of converging flow, where ice flow is subject to non-coaxial strain and simple shear. They can be traced continuously through crevasse fields and through blue-ice areas, indicating that they represent the surface manifestation of a three-dimensional structure, interpreted as foliation. Flow lines are linear and undeformed for all major flow units described here in the Antarctic Ice Sheet except for the Kamb Ice Stream and the Institute and Möller Ice Stream areas, where areas of flow perturbation are evident. Parcels of ice along individual flow paths on the Lambert Glacier, Recovery Glacier, Byrd Glacier and Pine Island Glacier may reside in the glacier system for ~2500 to 18 500 years. Although it is unclear how long it takes for these features to form and decay, we infer that the major ice-flow configuration of the ice sheet may have remained largely unchanged for the last few hundred years, and possibly even longer. This conclusion has implications for our understanding of the long-term landscape evolution of Antarctica, including large-scale patterns of glacial erosion and deposition. [ABSTRACT FROM AUTHOR]

Posterior fossa subdural hygromas are very rare. They tend to occur following direct occipital trauma. We present an unusual case of complex subdural hygroma of the posterior fossa, which was associated with a supratentorial chronic subdural haematoma. This developed after an apparently minor injury to the head. The unusual features of our case are discussed. We also review the literature and discuss the natural history and pathogenesis of subdural hygroma. [ABSTRACT FROM AUTHOR]

Energy expenditure is an important parameter in the assessment of gait and orthotic treatment of locomotor disabilities. Up until now oxygen uptake measurement has been the most common method used to assess this. In able bodied subjects heart rate monitoring is also increasingly used. In high thoracic level lesion paraplegics monitoring heart rate was considered to be unreliable because of suspicion of injury to the sympathetic contribution to the cardiac plexus. Bar-On & Nene found that in paraplegics below the lesion level T3 heart rate still shows linear relation to oxygen uptake. MacGregor combined the heart rate and speed of locomotion to produce a single index called physiological cost index. This study consists of monitoring heart rate and speed of 16 adult thoracic level paraplegics walking with the ORLAU ParaWalker, calculation of their physiological cost index, and establishing a range of physiological cost index of paraplegic locomotion using the ORLAU ParaWalker.

Functional intramuscular electrical stimulation of the gluteus maximus and gluteus medius on the stance side whilst walking is reported. The subject was an adult, male, post-traumatic complete paraplegic with lesion level at T7. He had been using surface stimulation to aid his walking with the adult ParaWalker Orthosis but suffered unpleasant anterior abdominal wall muscle contractions with high amplitude stimulation. The experimental use of percutaneous intramuscular Platinum/Iridium wire electrodes demonstrated that more forceful contractions of the buttock muscles could be achieved without any effect on abdominal wall musculature. This prompted the use of a permanent, implanted system. The system is inductively coupled to an external control device and is working satisfactorily 7 months after implantation.

The efficacy and safety of haloperidol, lithium carbonate, and placebo were critically assessed in 61 treatment-resistant, hospitalized children aged 5.2 to 12.9 years with diagnoses of conduct disorder, aggressive type. In this double-blind and well-controlled study, the optimal dosages of haloperidol ranged from 1.0 to 6.0 mg/day and those of lithium carbonate from 500 to 2,000 mg/day. For the assessment of behavioral changes and untoward effects, various rating scales were used in different settings. Both haloperidol and lithium carbonate were found to be significantly superior to placebo in decreasing behavioral symptoms. Although both medications were clinically effective, haloperidol was associated more often with untoward effects than was lithium carbonate.