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We present techniques developed to calibrate and correct Murchison Widefield Array low-frequency (72–300 MHz) radio observations for polarimetry. The extremely wide field-of-view, excellent instantaneous (u, v)-coverage and sensitivity to degree-scale structure that the Murchison Widefield Array provides enable instrumental calibration, removal of instrumental artefacts, and correction for ionospheric Faraday rotation through imaging techniques. With the demonstrated polarimetric capabilities of the Murchison Widefield Array, we discuss future directions for polarimetric science at low frequencies to answer outstanding questions relating to polarised source counts, source depolarisation, pulsar science, low-mass stars, exoplanets, the nature of the interstellar and intergalactic media, and the solar environment.

Dose-response experiments showed that three samples of green foxtail collected from fields in southern Manitoba where trifluralin had not controlled the weed in 1987 were resistant to the herbicide. GR50 values indicated that the resistant populations were about 5 times more resistant to trifluralin than susceptible populations, about twice as resistant as wild oat, and about equally resistant as wheat. An additional 33 samples collected in 1988 from southwestern Manitoba where trifluralin has been used for nearly 20 yr in both cereal and oilseed crops were resistant to trifluralin.

It is commonly assumed in affluent, Western, democratic societies that by enhancing opportunities for choice, we enhance freedom and well-being, both by enabling people to get exactly what they want and by enabling people to express their identities. In this paper, we review evidence that the relationships between choice, freedom, and well-being are complex. The value of choice in itself may depend on culture, and even in cultural contexts that value choice, too much choice can lead to paralysis, bad decisions, and dissatisfaction with even good decisions. Policy-makers are often in a position to enhance well-being by limiting choice. We suggest five questions that policy-makers should be asking themselves when they consider promulgating policies that will limit choice in the service of enhanced well-being. The relationships between choice, freedom, and well-being are not simple, and an appreciation of their complexity may help policy-makers target their interventions more effectively.

Using a simple characterization of the Linnik distribution, discrete-time processes having a stationary Linnik distribution are constructed. The processes are structurally related to exponential processes introduced by Arnold (1989), Lawrance and Lewis (1981) and Gaver and Lewis (1980). Multivariate versions of the processes are also described. These Linnik models appear to be viable alternatives to stable processes as models for temporal changes in stock prices.

It was with great surprise and some disappointment that I took note in the July 1987 issue of the American Journal of International Law of the decision by the American Society of International Law to divest its investment portfolio of stocks in all corporations with direct investments in South Africa. Despite the sentiments that may have motivated this decision, many of which are reflected in the Note of Henry J. Richardson III, there were no doubt many arguments voiced to the contrary at the meeting of the Society when the matter was discussed.

Lawn burweed is a serious problem in warm-season golf courses, sports fields, and residential turfgrass. Field studies were conducted at three sites in Florida to evaluate herbicides applied postemergence for control of lawn burweed. Mecoprop + 2,4-D + dicamba provided > 95% control of lawn burweed when evaluated 47 to 55 d after treatment (DAT). MCPA + triclopyr + dicamba in either ester or amine forms, 2,4-D + triclopyr + dicamba, triclopyr, 2,4-D, and bromoxynil provided 88 to 100% control 40 to 55 DAT. Although triclopyr + clopyralid provided > 90% control in one study, it was not consistent and controlled < 75% of the lawn burweed present in another experiment. Simazine was unacceptable for lawn burweed control. Bermudagrass turf was not injured by any of the treatments evaluated. Mecoprop + 2,4-D + dicamba caused minimal short-term injury to centipedegrass.

We describe the evolution of neuropathology in Canada, beginning with William Osler who began working in Montréal in 1874 and finishing with the major period of expansion in the 1970s. Organized services began in the 1930s, in Montréal with the neurosurgeons Wilder Penfield and William Cone, and in Toronto with Eric Linell and Mary Tom, who both began their careers as neuroanatomists. Jerzy Olszewski and Gordon Mathieson, who trained in Montréal and Toronto, drove the creation of the CanadianAssociation of Neuropathologists in 1960. Training guided by the Royal College of Physicians and Surgeons of Canada was formalized in 1965, with the first certifying examination in 1968 and the subsequent creation of formal structured training programs. The number of neuropathologists in Canada increased rapidly through the 1960s and 1970s, with individuals coming from both clinical neuroscience and anatomic pathology backgrounds, a pattern that persists to the present day.

This article describes the properties of the Farm Financial Simulation Model (FFSM). FFSM is a tool for analyzing the financial consequences of various managerial strategies and policy options that may be implemented in responding to farm financial stress. Various farm types from different geographical regions having differing enterprises, financial structures, tenure arrangements, and consumption patterns can be analyzed. The emphasis of FFSM is placed on modeling a farm's profitability, liquidity, solvency, and financial position and the model produces a coordinated set of financial statements and an extensive set of financial ratios over a four-year period.

The entire series of Durchmusterung (DM) catalogs (Bonner, Southern, Córdoba, Cape Photographic) has been computerized through a collaborative effort among institutions and individuals in France and the United States of America. Complete verification of the data, both manually and by computer, the inclusion of all supplemental stars (represented by lower case letters), complete representation of all numerical data, and a consistent format for all catalogs, should make this collection of machine-readable data a valuable addition to digitized astronomical archives.

Using a simple characterization of the Linnik distribution, discrete-time processes having a stationary Linnik distribution are constructed. The processes are structurally related to exponential processes introduced by Arnold (1989), Lawrance and Lewis (1981) and Gaver and Lewis (1980). Multivariate versions of the processes are also described. These Linnik models appear to be viable alternatives to stable processes as models for temporal changes in stock prices.

We investigate some preservation properties of two nonparametric classes of survival distributions and their duals, under appropriate reliability operations. The aging properties defining these nonparametric classes are based on comparing the mean life of a new unit to the mean residual life function of the asymptotic remaining survival time of the unit under repeated perfect repairs. They are motivated from a point of view that realistic notions of degradation, applicable to repairable systems, should be based on contrasting some aspect of the remaining life of a repairable unit (under a given repair strategy, such as renewals) to the life of a new unit.

Active surveillance to identify asymptomatic carriers of carbapenem-resistant Enterobacteriaceae (CRE) is a recommended strategy for CRE control in healthcare facilities. Active surveillance using stool specimens tested for Clostridium difficile is a relatively low-cost strategy to detect CRE carriers. Further evaluation of this and other risk factor-based active surveillance strategies is warranted.

The impact of community-associated Clostridium difficile infection (CA-CDI) on patients with spinal cord injuries and disorders (SCI/Ds) is not fully understood. We examined CA-CDI cases among veterans with SCI/D, comparing them with community-onset, healthcare facility-associated (CO-HCFA) cases. Generally, patients with CA-CDI had less comorbidity, less severe CDI, and lower likelihood of antibiotic exposure.

A female child, TK, was born January 12, 1965, and was initially admitted to the Hospital for Sick Children, Toronto, on January 13, 1972, at age seven years with a sevenday history of runny nose, earache, headache, and fever. On the day before admission, she had a grand mal seizure and lumbar puncture revealed purulent cerebrospinal fluid (C.S.F.) which grew pneumococci. She was treated with antibiotics, her meningitis resolved, and she was discharged home nine days after admission.

In many areas of government policy there is a big gap between theory and practice, that is, there is a difference between what ought to occur and what actually eventuates. This is unfortunately true for education as well. That education actually alienates the young from the old and from their traditional life-style may in some way be substantiated. In theory this should not happen. Before any discussion on the pros and cons of such a state of affairs, however, there is a need to define what education is, to define some of the approaches officially accepted in Aboriginal education and to differentiate between the needs of some of the more recognizable Aboriginal groups and their life-styles.

In many areas of government policy there is a big gap between theory and practice, that is, there is a difference between what ought to occur and what actually eventuates. This is unfortunately true for education as well. That education actually alienates the young from the old and from their traditional life-style may in some way be substantiated. In theory this should not happen. Before any discussion on the pros and cons of such a state of affairs, however, there is a need to define what education is, to define some of the approaches officially accepted in Aboriginal education and to differentiate between the needs of some of the more recognizable Aboriginal groups and their life-styles.

Education can be defined as all the ways in which one person deliberately tries to influence the behaviour of another person. Behaviour may include knowledge, skills, habits, values and attitudes (Butts, n.d.). I believe education should serve either or both of two purposes -

1. the acquisition of knowledge, skills, habits, values and attitudes which can be used to assist his community/society to attain a better standard of living, that is, economic development and/or quality of life, and/or

2. to enable a person to be a better and more useful citizen in his/her society.

Farm level risk analyses have used price and yield variability almost exclusively to represent risk. Results from a survey of 149 agricultural producers in 12 states indicate that producers consider a broader range of sources of variability in their operations. Significant differences exist among categories with respect to the importance of the sources of variability in crop and livestock production. Producers also used a variety of management responses to variability. There were significant difference among categories in the importance given to particular responses and their use of them. These results have implications for research, extension, and policy programs.