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Purpose : To measure the research productivity of trainees from the University of Toronto's Medical Imaging Clinician Investigator Program (MI-CIP) and comparing it with the research productivity of trainees from MI-non-CIP and General Surgery (GSx) Clinician Investigator Program. Methods : We identified residents who completed an MI-CIP, MI-non-CIP and GSx-CIP from 2006-2016. In each group of trainees, we assessed 3 research productivity outcomes with non-parametric tests before residency and at 7 years post-CIP completion/post-graduation. Research productivity outcomes include the number of total publications, the number of first-author publications, and the publication's average journal impact factor (IF). Results : We identified 11 MI-CIP trainees (male/female: 9 [82%]/2 [18%]), 74 MI-non-CIP trainees (46 [62%]/28 [38%]) and 41 GSx-CIP trainees (23 [56%]/18 [44%]). MI-CIP trainees had statistically significant higher research productivity than MI-non-CIP in all measured outcomes. The median (interquartile range, IQR) number of total publications of MI-CIP vs MI-non-CIP trainees was 5.0 (8.0) vs 1.0 (2.0) before residency and 6.0 (10.0) vs.0 (2.0) at 7 years post-CIP completion/post-graduation. The median (IQR) first-author publications of MI-CIP vs MI-non-CIP trainees was 2.0 (3.0) vs.0 (1.0) before residency and 2.0 (4.0) vs (.0) (1.0) at 7 years post-CIP completion/post-graduation. The median (IQR) average journal IF of MI-CIP vs MI-non-CIP trainees was 3.2 (2.0) vs.3 (2.4) before residency and 3.9 (3.2) vs.0 (2.6) at 7 years post-CIP completion/post-graduation. Between MI-CIP and GSx-CIP trainees, there were no significant differences in research productivity in all measured outcomes. Conclusion : MI-CIP trainees actively conducted research after graduation. These trainees demonstrated early research engagement before residency. The similar research productivity of MI-CIP vs GSx-CIP trainees shows initial success of MI-CIP trainees. [ABSTRACT FROM AUTHOR]

Case-crossover designs have been widely applied to epidemiological and medical investigations of associations between short-term exposures and risk of acute adverse health events. Much effort has been made in literature on understanding source of confounding and reducing systematic bias by reference-select strategies. In this paper, we explored the nature of bias in the ambi-directional and time-stratified case-crossover designs via simulation using actual air pollution data from urban Edmonton, Alberta, Canada. We further proposed a calibration approach for eliminating systematic bias in estimates (coefficient estimate, 95% confident interval, and p-value). Bias check for coefficient estimation, size check and power check for significance test were done via simulation experiments to show advantages of the calibrated case-crossover studies over the ones without calibration. An application was done to investigate associations between air pollutants and acute myocardial infarction hospitalizations in urban Edmonton. In conclusion, systematic bias in a case-crossover design is often unavoidable, leading to an obvious bias in the estimated effect and an unreliable p value in the significance test. The proposed calibration technique provides an efficient approach to eliminating systematic bias in a case-crossover study. [ABSTRACT FROM AUTHOR]

Background: Hypertrophy of the lingual tonsil tissue in the adult patient is thought to contribute to the pathophysiology of obstructive sleep apnea. The underlying etiology of lingual tonsil hypertrophy (LTH) in the adult patient is unclear and likely multifactorial. Previous studies have suggested that the lingual tonsils may undergo compensatory hyperplasia post-tonsillectomy in children, although it is unknown if this occurs or persists into adulthood. The purpose of this study was to determine what factors are associated with LTH in a population of Canadian adults. Methods: Adult patients presenting for consultation to an academic Rhinology/General Otolaryngology practice were eligible for enrollment. Demographic data including age, body mass index (BMI), Reflux Symptom Index (RSI), history of allergy, and history of tonsillectomy was collected via questionnaire. Endoscopic photographs of the base of tongue and larynx were captured. These were graded for LTH and Reflux Finding Scale (RFS) by blinded examiners. Statistical analysis was performed by comparing the mean LTH value to the variables of interest using two-tailed -test. <.05 was considered significant. Results: One hundred two subjects were enrolled. Age ranged from 18 to 78. 28 patients had previous tonsillectomy. This was not associated with a significant increase in lingual tonsil tissue ( = -0.05, = 0.61). RFS >7 or RSI >13 was considered positive for laryngopharyngeal reflux. There was no difference in LTH based on RSI positivity ( = 0.44). RFS positivity correlated with increased lingual tonsil tissue ( < 0.05). BMI >30 was associated with increased lingual tonsil hypertrophy ( <0.05). Conclusions: An elevated body mass index and positive Reflux Finding Score are associated with lingual tonsil hypertrophy in adults. Reflux symptom index, history of allergy and history of childhood tonsillectomy are not associated with LTH. [ABSTRACT FROM AUTHOR]

Objective: To investigate the prevalence of occipital bending (an occipital lobe crossing or twisting across the midline) in subjects with schizophrenia and matched healthy controls. Method: Occipital bending prevalence was investigated in 37 patients with schizophrenia and 44 healthy controls. Results: Ratings showed that prevalence was nearly three times higher among schizophrenia patients (13/37 [35.1%]) than in control subjects (6/44 [13.6%]). Furthermore, those with schizophrenia had greater normalized gray matter volume but less white matter volume and had larger brain-to-cranial ratio. Conclusion: The results suggest that occipital bending is more prevalent among schizophrenia patients than healthy subjects and that schizophrenia patients have different gray matter-white matter proportions. Although the cause and clinical ramifications of occipital bending are unclear, the results infer that occipital bending may be a marker of psychiatric illness. [ABSTRACT FROM AUTHOR]

In this paper we explore the links between internal migration and international immigration in Canada's three largest metropolitan areas. In particular, we use a place-specific approach to test the displacement hypothesis that the migration behaviour of the less-well-educated native-born population is sensitive to the inflows of immigrants. Based on analyses of microdata from five consecutive censuses covering the period from 1981 to 2001, we find that the migration - immigration relationships are complex, often subtle, and inconsistent across the three cities. Growth in the immigrant population is correlated with an increased out migration rate among the less-well-educated native-born population, but only in Toronto and Vancouver. This correlation, however, is not independent of changes in housing prices. We also find no consistent support for an alternative hypothesis that economic restructuring accounts for the net out-migration from immigrant gateway cities. [ABSTRACT FROM AUTHOR]