Delivering the goods? Access to family physician services in Canada: a comparison of 1985 and 1991

In recent years considerable attention has been given to the effects of universal, first-dollar coverage for health care services as provided under Canada's health care system. However, no consideration has been given to the stability of these effects through periods of changing economic climate. In this paper we consider the extent to which the achievements of the Canadian approach to health care funding have been maintained in the presence of increasing attention to cost containment. Multivariate analyses are used to (a) explain variations in utilization of family physician services among the population and (b) explore the relationship between utilization and need for periods of differing economic circumstances. We observe that the relative importance of differences in need in explaining variations in use among the population was less in the period when cost containment was of greater concern. These findings indicate that policymakers cannot assume that removing financial barriers to access to service, although important in achieving a more equitable distribution of service utilization, may be sufficient to sustain such distributions during time of constraint.     

Estimating Respiratory Mechanical Parameters in Parallel Compartment Models

Four iterative parameter estimation algorithms were used to obtain estimates in three parallel compartment models of the respiratory system. The stability of the parameter estimates and the agreement between the forced random noise impedance data and the model's response were evaluated for each algorithm-model combination. The combination of a two-stage simplex algorithm with a five element model provided the most stable parameter estimates and the second best fit to the data.     

Breaking the frame-buffer bottleneck with logic-enhanced memories

Logic-enhanced memory chips that can remove the rasterizer/frame buffer bottleneck which limits the performance of current image-generation architectures are discussed. Putting pixel memory on-chip with rasterizing processors provides the two to three orders of magnitude improvement in access rates needed to support realistic shading models and aliasing in interactive systems. Current high-performance graphics systems and logic-enhanced memory architectural issues are reviewed. The design of the PixelFlow Enhanced Memory Chip (EMC), which exploits advances in semiconductor technology and circuit techniques to build compact, high-performance rasterizers, is described     

Vibrio cholerae and enteric bacteria in oyster-producing areas of two urban estuaries in Australia

Three sampling sites in oyster-producing areas of 2 estuaries were monitored at intervals of about 2 weeks for 1 year. Oysters (Crassostrea commercialis), water and sediment were examined for Vibrio cholerae, Escherichia coli and Salmonella. V. cholerae was detected in 20, 30 and 11% of oyster, water and sediment samples respectively. The highest incidence was in the autumn (March-May), with few isolations from July to October. Most isolates were non-O1 serotypes. The presence of V. cholerae and the enteric bacteria appeared to be influenced by different, but perhaps overlapping, sets of factors in these high salinity waters. There was no relationship between rainfall or salinity and the detection of V. cholerae, whereas high counts of E. coli in oysters and the presence of Salmonella were correlated wtih rainfall and, to a lesser degree, reduced salinity. High counts of E. coli were correlated with V. cholerae isolations from water and with the presence of Salmonella. Oysters concentrated E. coli effectively. The counts of E. coli in oysters were 7.3 times higher than those in water. Examination of 8 batches of purified and unpurified oysters indicated that purification reduces the incidence of V. cholerae. However V. cholerae was detected in 3 of 25 market samples of oysters, demonstrating that it can be present in oysters throughout the distribution system. The highest V. cholerae count observed in oysters was 3/g.     

Innovative processes and technologies for modified atmosphere packaging of fresh and fresh-cut fruits and vegetables

Modified atmosphere packaging (MAP) technology has been commercially viable since the 1970s. Currently, MAP is extensively used worldwide to preserve the quality and extend the shelf-life of whole fresh fruits and vegetables, but is also increasingly used to extend the shelf-life of minimally processed fresh fruit and vegetables. This review discusses new processes and technologies that can be used to improve quality preservation and consumer acceptability of minimally processed produce where high respiration rates and challenging degradation processes operate. New packaging innovations are enabling producers and retailers to further maintain quality for longer. Innovative approaches to extend shelf-life include active MAP with differentially permeable films, films that incorporate antimicrobial properties, edible coatings that confer barriers properties, and the use of non-traditional gases to modify respiration. Intelligent packaging using integrated sensor technologies that can indicate maturity, ripeness, respiration rate and spoilage are also appearing. This review demonstrates that preservation technologies and associated packaging developments that can be combined with modified atmosphere are constantly evolving technology platforms. Adoption of combinations of technology improvements will be critical in responding to commercial trends towards more minimally processed fresh-cut and ready-to-eat fruit and vegetable products, which require specialized packaging solutions.     

Phenolic Chemistry of Coast Live Oak Response to <Emphasis Type="Italic">Phytophthora ramorum</Emphasis> Infection

Since the mid 1990s, Phytophthora ramorum has been responsible for the widespread mortality of tanoaks, as well as several oak species throughout California and Oregon forests. However, not all trees die, even in areas with high disease pressure, suggesting that some trees may be resistant to the pathogen. In this study, the chemical basis of host resistance was investigated. Three field experiments were carried out in California between December 2004 and September 2005. The levels of nine phenolic compounds (gallic acid, catechin, tyrosol, a tyrosol derivative, ellagic acid, and four ellagic acid derivatives) extracted from the phloem of trees that had been either artificially inoculated with P. ramorum or trees putatively infected with P. ramorum (based on canker symptoms) were quantified by high-performance liquid chromatography (HPLC). Significant differences in phenolic profiles were found between phloem sampled from the active margins of cankers, healthy phloem from asymptomatic trees, and phloem sampled 60 cm away from canker sites, although the magnitude and direction of the responses was not consistent across all experiments. Concentrations of gallic acid, tyrosol, and ellagic acid showed the greatest differences in these different tissues, but varied considerably across treatments. Gallic acid and tyrosol were tested in in vitro bioassays and showed strong dose-dependent inhibitory effects against P. ramorum, P. cinnamomi, P. citricola, and P. citrophthora. These results suggest that phloem chemistry varies in response to pathogen infection in California coast live oak populations and that changes in phloem chemistry may be related to apparently resistant phenotypes observed in the field. Frances S. Ockels and Alieta Eyles contributed equally to the paper