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P Paddon

Publications and source records attributed to P Paddon.

12 recordsLinked to original sources
PubMed2001

Resonant scattering and mode coupling in two-dimensional textured planar waveguides.

A heuristic formalism is developed for efficiently determining the specular reflectivity spectrum of two-dimensionally textured planar waveguides. The formalism is based on a Green's function approach wherein the electric fields are assumed to vary little over the thickness of the textured part of the waveguide. Its accuracy, when the thickness of the textured region is much smaller than the wavelength of relevant radiation, is verified by comparison with a much less efficient, exact finite difference solution of Maxwell's equations. In addition to its numerical efficiency, the formalism provides an intuitive explanation of Fano-like features evident in the specular reflectivity spectrum when the incident radiation is phase matched to excite leaky electromagnetic modes attached to the waveguide. By associating various Fourier components of the scattered field with bare slab modes, the dispersion, unique polarization properties, and lifetimes of these Fano-like features are explained in terms of photonic eigenmodes that reveal the renormalization of the slab modes due to interaction with the two-dimensional grating. An application of the formalism, in the analysis of polarization-insensitive notch filters, is also discussed.

Journal Article↗
PubMed1990

Acute myocardial infarction. A feasibility study using record-linkage of routinely collected health information to create a two-year patient profile. Manitoba, 1984-85 and 1985-86.

Manitoba's hospital separations and physician medical files were linked for the fiscal years 1984-85 and 1985-86. The result was a study file consisting of records for 5,293 males and 3,143 females, who, during this period, suffered an Acute Myocardial Infarction (AMI), commonly called a heart attack. Merging the two types of files created a comprehensive data base for these AMI victims. The Manitoba age-sex standardized AMI rate was 38.0 per 10,000 population. Age-specific rates were higher for males than for females for all age groups. Hospitalized cases accounted for 7,201 individuals or 85.4% of AMI victims. Age-sex standardized rates of hospitalization per 10,000 population ranged from 27.1 in the Central region to 36.0 in the Westman region. The Manitoba age-specific rates of hospitalization for males in the 35-54 and 55-64 age groups were about three times the female rates for the same age groups. One quarter of AMI hospitalized victims died in hospital. The Manitoba age-specific death rates for males in the 35-54, 55-64 and 65-74 age groups were double the rates for females in the same age groups. Of the 8,436 AMI victims under study, 86.4% had at least one other concurrent medical condition such as angina, other forms of ischemic heart disease, diabetes, or hypertension. Of AMI victims, 93.8% underwent at least one of the following procedures: coronary artery bypass surgery, angiogram, electrocardiogram, cardiac catheterization, arteriography, or blood cholesterol testing. A higher percentage of procedures was performed on males than on females.

Acute Disease↗
PubMed1990

Coronary artery bypass surgery in Canada.

This report examines trends in the number and the rates of coronary artery bypass surgery (CABS) in Canada, performed over a six-year period from 1981-82 to 1986-87. The analysis includes comparisons of rates and events by sex, age and geographic location. In Canada 10,865 CABS were performed in 1986-87 representing a 39% increase over 1981-82. During the same period the rate of CABS rose to 43.2 per 100,000 population. In the twelve census metropolitan areas (CMAs) covered in this study, CABS increased 45.7% from 6,477 in 1981-82 to 9,439 in 1986-87, while hospital separations for Ischemic Heart Disease (IHD) increased by 22.6%. Regionally the coronary artery bypass surgery rate was lowest in Halifax at 62.4 per 100,000 population and highest in Ottawa-Hull at 131.8 per 100,000 population. The average annual proportion of CMAs ranged from 15.5% for residents in Halifax (84.5% for non-residents) to a high of 65.7% for residents in Montreal (34.3% for non-residents). Procedure rates increased consistently among the 65-74 and 75+ age groups, remained stable in the 55-64 age group, and decreased in the 35-54 age group. The variations among the CMAs may in part be due to the amount of resources available in each CMA, the demand for this type of service and perhaps to differing patterns of physician practice.

Adult↗
PubMed1989

Canadian nurses.

Explore the source record for details and available documents.

Canada↗
PubMed1989

Accidents in Canada: mortality and hospitalization.

For Canadians under 45, accidents are the leading cause of both death and hospitalization. For the Canadian population as a whole, accidents rank fourth as a cause of death, after cardiovascular disease (CVD), cancer and respiratory disease. This article analyzes accident mortality and hospitalization in Canada using age-specific rates, age-standardized mortality rates (ASMR), and potential years of life lost (PYLL). The six major causes of accidental death for men are motor vehicle traffic accidents (MVTA), falls, drowning, fires, suffocation and poisoning. For women, the order is slightly different: MVTA, falls, fires, suffocation, poisoning and drowning. From 1971 to 1986, age-standardized mortality rates (ASMR) for accidents decreased by 44% for men and 39% for women. The largest decrease occurred in the under 15 age group. Accidents accounted for 11.5% of total hospital days in 1985, and 8% of hospital discharges. Because young people have the highest rates of accidental death, potential years of life lost (PYLL) are almost as high for accidents as for cardiovascular disease, although CVD deaths outnumbered accidental deaths by almost five to one in 1985.

Accident Prevention↗