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Biomedical subjects

R Dufresne

Publications and source records attributed to R Dufresne.

8 recordsLinked to original sources
PubMed1999

Stages of change across ten health risk behaviors for older adults.

Owing to the recent success of the Transtheoretical Model of behavior change and the possible relationships between health behaviors, this study investigated the stage distribution of 10 healthy behaviors (seatbelt use, avoidance of high fat food, eating a high-fiber diet, attempting to lose weight, exercising regularly, avoiding sun exposure, sunscreen use, attempting to reduce stress, stopping smoking, and conducting cancer self-exams) and their interrelationships in a representative sample of health maintenance organization (HMO) members. The majority of older adults were found to be in either precontemplation or maintenance, illustrating the need to target interventions to precontemplation. Most older individuals were in precontemplation for losing weight and/ or sunscreen use and exercise, making these behaviors a priority for intervention research. Possible gateway behaviors to general health could be identified; however, these results are preliminary and require longitudinal follow-up.

Aged↗
PubMed1996

Listening to Narcissus (when words alone do not suffice ...).

In the myth of Narcissus on which it is based, the author argues, narcissism is not a mere infatuation with one's self-image, but at once the fear of and the withdrawal from the apprehended power, possession and desire of the other. In the analysis of a survivor of the Holocaust, after a very long period of unspoken transference, an archaic and violent transference ultimately emerges in which the absolute fright before the risks of passivity and enslavement hinders the desperate search for the object. In order to avoid an impasse, the analyst must engage in more active listening and interpretations by anticipation. The analysis of narcissistic pain requires not that the narcissistic and the object relations perspectives stand in isolation from each other either in time or in theory, but that their intertwining be perceived and interpreted.

Concentration Camps↗
PubMed1992

Localized carcinoma of the external ear is an unrecognized aggressive disease with a high propensity for local regional recurrence.

Management problems in patients with recurrent squamous cell carcinoma (SCC) of the external ear (pinna) have prompted a review of the management and treatment outcomes of patients who present with localized disease. Forty patients were seen over a 15-year period (1972 to 1991). Thirty-six were men, and 4 were women, with an age range from 43 to 93 years (average age: 71 years). Presenting TNM status was stage 0 in 2 patients, stage I in 15 patients, stage II in 13 patients, stage III in 2 patients, stage IV in 4 patients, and unknown stage in 4 patients. Thirty-six patients had clinically negative nodes at presentation (N0), and 4 had palpable nodes (N+). The primary treatment was local excision in 13 patients, Mohs' micrographic surgery in 16 patients, local excision plus external beam radiotherapy in 4 patients, and radical resection (parotidectomy/neck dissection/mastoidectomy) with or without radiotherapy in 5 patients. Two patients with stage IV disease died after diagnosis and prior to treatment, and two other patients with stage IV disease received palliative chemotherapy. Twenty patients developed recurrence from 2 months to 8 years. It included nine local recurrences, eight regional recurrences (parotid/neck/mastoid), and three distant metastases (lung or brain). After treatment of the recurrences in 20 patients, 8 are alive 15 months to 16 years later, 2 patients died of other diseases, and 10 patients died of SCC. The recurrences were managed by reoperation, radiotherapy, or chemotherapy. From the results of this study, we conclude that localized carcinoma of the external ear has a high propensity for local and regional failure and merits more aggressive treatment of the primary lesion and elective treatment of the regional lymph nodes and parotid gland in high-risk patients.

Adult↗
PubMed1989

The relation between problem categorization and problem solving among experts and novices.

These investigations were conducted to examine the relationship between problem-solving ability and the criteria used to decide that two classical mechanics problems would be solved similarly. We began by comparing experts and novices on a similarity judgment task and found that the experts predominantly relied on the problems' deep structures in deciding on similarity of solution, although the presence of surface-feature similarity had a clear adverse effect on performance. The novices relied predominantly on surface features, but were capable of using the problems' deep structures under certain conditions. In a second experiment, we compared groups of novices, at the same level of experience, who tended to employ different types of reasoning in making similarity judgments. Compared to novices who relied predominantly on surface features, novices who made greater use of principles tended to categorize problems similarly to how experts categorized them, as well as score higher in problem solving. These results suggest that principles play a fundamental role in the organization of conceptual and procedural knowledge for good problem solvers at all levels.

Adult↗
PubMedDate not supplied

Anaerobic treatment of condensates: trial at a kraft pulp and paper mill.

The Domtar Papers pulp and paper mill in Windsor, Quebec, Canada, investigated the potential for anaerobic treatment of contaminated kraft mill condensates. The objectives of this project were to assess the technical feasibility of replacing the steam stripper with anaerobic treatment, to provide basic information for the design of an anaerobic treatment process for condensates, and to provide information on treated condensate quality for eventual reuse. The project involved extensive chemical characterization of condensates, followed by treatability tests. The tests included laboratory bench-scale tests and on-site pilot testing using direct feed from the process. Characterization showed that the organic content of the condensates was essentially methanol, as expected, but that foul evaporator condensates had high sulfide contents. It was found that undiluted foul condensates at the Windsor mill are toxic to the anaerobic biomass because of these high concentrations of sulfides. Treatment of combined condensates is possible at an approximate volumetric loading of 10 to 12 g/L.d chemical oxygen demand (COD) with good production of biogas (0.35 L/g of COD removed) and excellent methanol removal (better than 95%). The biogas produced is of excellent fuel quality with close to 90% methane, but with a high sulfide content (close to 4%).

Bacteria, Anaerobic↗