A novel video-tracking system to quantify the behaviour of nocturnal mosquitoes attacking human hosts in the field.

Many vectors of malaria and other infections spend most of their adult life within human homes, the environment where they bloodfeed and rest, and where control has been most successful. Yet, knowledge of peri-domestic mosquito behaviour is limited, particularly how mosquitoes find and attack human hosts or how insecticides impact on behaviour. This is partly because technology for tracking mosquitoes in their natural habitats, traditional dwellings in disease-endemic countries, has never been available. We describe a sensing device that enables observation and recording of nocturnal mosquitoes attacking humans with or without a bed net, in the laboratory and in rural Africa. The device addresses requirements for sub-millimetre resolution over a 2.0 × 1.2 × 2.0 m volume while using minimum irradiance. Data processing strategies to extract individual mosquito trajectories and algorithms to describe behaviour during host/net interactions are introduced. Results from UK laboratory and Tanzanian field tests showed that Culex quinquefasciatus activity was higher and focused on the bed net roof when a human host was present, in colonized and wild populations. Both C. quinquefasciatus and Anopheles gambiae exhibited similar behavioural modes, with average flight velocities varying by less than 10%. The system offers considerable potential for investigations in vector biology and many other fields.

Algorithms for the automated analysis of cellular dynamics within living fungal colonies.

We present robust and efficient algorithms to automate the measurement of nuclear movement and germ tube extension rates in living fungal networks. The aim is to facilitate the understanding of the dynamics and regulation of nuclear migration in growing fungal colonies. The proposed methodology combines a cascade correlation filter to identify nuclear centers from which 2D nuclear velocities are determined and a level set algorithm for centerline extraction to monitor spore (conidial) germling growth. We show how the proposed cascaded filter improves spatial resolution in the presence of noise and is robust when fluorescently labeled nuclei with different intensities are in close proximity to each other. The performance of the filter is evaluated by simulation in comparison to the well known Rayleigh and Sparrow criteria, and experimental evidence is given from clusters of nuclei and nuclei undergoing mitotic division. The capabilities developed have enabled the robust and objective analysis of 10's of Gigabytes of image data that is being exploited by biological scientists.

Clinical program development in an Alberta Capital Health Authority.

Developing a continuum of service delivery with provider input in a new health region has posed a major challenge. Planning service delivery by program has recently been considered an improvement over site-specific and discipline-specific planning. Implementing program councils has fundamentally restructured service planning in the Capital Health region: providers now plan together, focusing on the needs of patients/clients and the community.

Growth patterns in the eye of Petrolisthes elongatus (Crustacea; Decapoda; Anomura).

The eye of Petrolisthes elongatus is of the reflecting superposition type. The facets are square and the dioptric apparatus consists of a crystalline cone and a conestalk, each made up of four identical radially arranged units. The rhabdom has an elonagated (2-3 microns diameter) distal segment and a much thicker (6-16 microns diameter) proximal section. The distribution of screening pigments alters dramatically in a migration associated with changes in adaptational state. The following trends with increasing age, monitored as carapace length, were found: (1) increasing number of facets; (2) increasing size of eye and eye-stalk; (3) increasing length of eye-stalk in proportion to eye length; (4) increasing breadth of eye-stalk in proportion to eye breadth; (5) increasing breadth of eye-stalk and eye in proportion to length of eye-stalk and eye; (6) increase in volume of both retinal and dioptric structures; (7) slight increase in rhabdom width; (8) increase in crystalline cone length and breadth and (9) increase in focal length. The results of these trends were presumed to be, firstly, an increase in absolute sensitivity of single ommatidia; secondly, an increase in sensitivity to point sources of light and, thirdly, an increase in angular visual field of the whole eye.

A system of workload measurement for clinical dietitians.

Although the role of the clinical dietitian has undergone dramatic change in recent years, standards for staffing patterns that were developed in 1935 and often still in use. The need for workload measurement systems to quantify the daily activities performed by clinical dietitians led to the development of a new system at the University of Alberta Hospitals in 1984. The workload of clinical dietitians was divided into eight major categories and further divided into 60 activities. A one- or two-week study was conducted four times over an 18-month period. The results indicated that 44 to 54% of the dietitians' time was spent in activities involving direct patient care and team approach. The system has enabled this institution to quantify the workload of its clinical dietitians and may provide a vehicle to measure the impact of major changes on that workload. Since the system covers all possible activities of the clinical dietitian, it may be applicable for use in other institutions. In view of rising health care costs, hospitals must make greater efforts to improve the efficiency of their operations while maintaining the quality of health care services provided to patients. This issue, as it applies to clinical dietetics, was recently addressed by the Nutrition and Food Services Department at the University of Alberta Hospitals.