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Biomedical subjects

I Stewart

Publications and source records attributed to I Stewart.

At least 19 recordsLinked to original sources
PubMed2001

Where are the dolphins?

Interest in extraterrestrial life has tended to focus on a search for extrasolar planets similar to the Earth. But what of forms of intelligent life that are very different from those found on Earth? Some features of life will not be peculiar to our planet, and alien life will resemble ours in such universals. But if intelligent, non-humanoid aliens exist, where might they be? Would they wish to visit Earth and would we know if they did?

Animals↗
PubMed2000

Jumping champions

Explore the source record for details and available documents.

Journal Article↗
PubMed1999

Symmetry in locomotor central pattern generators and animal gaits.

Animal locomotion is controlled, in part, by a central pattern generator (CPG), which is an intraspinal network of neurons capable of generating a rhythmic output. The spatio-temporal symmetries of the quadrupedal gaits walk, trot and pace lead to plausible assumptions about the symmetries of locomotor CPGs. These assumptions imply that the CPG of a quadruped should consist of eight nominally identical subcircuits, arranged in an essentially unique matter. Here we apply analogous arguments to myriapod CPGs. Analyses based on symmetry applied to these networks lead to testable predictions, including a distinction between primary and secondary gaits, the existence of a new primary gait called 'jump', and the occurrence of half-integer wave numbers in myriapod gaits. For bipeds, our analysis also predicts two gaits with the out-of-phase symmetry of the walk and two gaits with the in-phase symmetry of the hop. We present data that support each of these predictions. This work suggests that symmetry can be used to infer a plausible class of CPG network architectures from observed patterns of animal gaits.

Animals↗
PubMed1999

Surgical treatment of chronic otitis media with effusion.

Otitis media with effusion is the most frequent reason for admission to hospital for surgery in children. There are worldwide differences in the management of the condition. Recent studies have evaluated indications for surgery, surgical treatment methods, outcome measures following surgery and sequelae. The present report defines the increased risk of behavioural problems in pre-school children with persistent disease. Factors affecting the outcome of surgery with ventilation tubes are discussed. Assessment is made of the complications due to the disease and those resulting from treatment with ventilation tubes. Finally, a review is made of the various international guidelines for the management of persistent disease as a basis for good clinical practice.

Child↗
PubMed1998

Chest computerized tomography scanning in patients presenting with head and neck cancer.

Between 1 to 16% of patients with head and neck squamous cell carcinoma (HNSCC) have synchronous tumours; the majority (> 50%) occurring within the lung. Previous studies have relied upon endoscopy and chest radiographs. The aim of this study was to determine the incidence of synchronous intrapulmonary tumours in this group of patients using computerized tomography (CT) scanning. Over 36 months, 111 consecutive patients were assessed at presentation by contrast enhanced CT scanning from the skull base to the diaphragm. Chest scans showed intrapulmonary lesions in 17 patients and 10 have, with time, been confirmed as neoplastic. These allowed treatment of three primary bronchial carcinomas following radical treatment of the index tumour and cancellation of radical treatment in five patients with metastases. Two patients with possible metastases at presentation underwent radical treatment to the index tumour with subsequent follow-up confirming metastatic chest disease. All 10 patients eventually died of either locoregional or metastatic disease. This is one of the first prospective reports of chest scanning in patients with head and neck cancer. An additional chest scan in this group, many of whom undergo a staging scan of the neck, requires an extra 10 min with no further contrast and in this study yielded a synchronous tumour rate of 9%.

Carcinoma, Squamous Cell↗