The University-Public Health Partnership for Public Health Research Training in Quebec, Canada.

Enhancing effective preventive interventions to address contemporary public health problems requires improved capacity for applied public health research. A particular need has been recognized for capacity development in population health intervention research to address the complex multidisciplinary challenges of developing, implementing, and evaluating public health practices, intervention programs, and policies. Research training programs need to adapt to these new realities. We have presented an example of a 2003 to 2015 training program in transdisciplinary research on public health interventions that embedded doctoral and postdoctoral trainees in public health organizations in Quebec, Canada. This university-public health partnership for research training is an example of how to link science and practice to meet emerging needs in public health.

[Training in knowledge translation from the view of the learner]. / La formation en partage et utilisation des connaissances sous l'angle de l'apprenant.

Current training in knowledge translation (KT) in the field of population health is mainly carried out in an academic context. However, Quebec health and social services KT managers, as well as population health researchers express a need for developing KT practical learning in a workplace context. We argue that, in line with professional development and a constructivist approach to pedagogy, KT training should include practice-based learning in addition to academic education.

Information in the sample covariate distribution in prevalent cohorts.

Methods of estimation and inference about survival distributions based on length-biased samples are well-established. Comparatively little attention has been given to the assessment of covariate effects in the context of length-biased samples, but prevalent cohort studies often have this objective. We show that, like the survival distribution, the covariate distribution from a prevalent cohort study is length-biased, and that this distribution may contain parametric information about covariate effects on the survival time. As a result, a likelihood based on the joint distribution of the survival time and the covariates yields estimates of covariate effects which are at least as efficient as estimates arising from a traditional likelihood which conditions on covariate values in the length-biased sample. We also investigate the empirical bias of estimators arising from a joint likelihood when the population covariate distribution is misspecified. The asymptotic relative efficiencies and empirical biases under model misspecification are assessed for both proportional hazards and accelerated failure time models. The various methods considered are applied in an illustrative analysis of risk factors for death following onset of dementia using data collected in the Canadian Study of Health and Aging.

Two-stage design of clinical trials involving recurrent events.

Mixed Poisson models are often used for the design of clinical trials involving recurrent events since they provide measures of treatment effect based on rate and mean functions and accommodate between individual heterogeneity in event rates. Planning studies based on these models can be challenging when there is a little information available on the population event rates, or the extent of heterogeneity characterized by the variance of individual-specific random effects. We consider methods for adaptive two-stage clinical trial design, which enable investigators to revise sample size estimates using data collected during the first phase of the study. We describe blinded procedures in which the group membership and treatment received by each individual are not revealed at the interim analysis stage, and a 'partially blinded' procedure in which group membership is revealed but not the treatment received by the groups. An EM algorithm is proposed for the interim analyses in both cases, and the performance is investigated through simulation. The work is motivated by the design of a study involving patients with immune thrombocytopenic purpura where the aim is to reduce bleeding episodes and an illustrative application is given using data from a cardiovascular trial.

Health promotion research and practice require sound policy analysis models: the case of Quebec's Tobacco Act.

In this paper we illustrate how policy analysis models can deepen our understanding of the challenges facing health promoters advocating for policy change. Specifically we describe the factors underpinning the adoption of Québec's Tobacco Act (1998) and the role played by actors from governmental public health agencies (GPHAs). Data were collected through interviews (n=39), newspapers articles (n=569) and documents (n > 200) from GPHAs, NGOs, the Québec National Assembly, and opponents to the legislative measures. Data collection and analysis were based on Sabatier and Jenkins-Smith's Advocacy Coalition Framework (1999) and Lemieux's theorization of coalition structuring (1998). We explain the adoption of the Act by: (1) the broad recognition within the policy elite of the main parameters of tobacco use (i.e. lethality, addictive properties, and legitimacy of governmental intervention), (2) the impacts of a series of events (e.g. cigarette contraband crisis) that enabled tobacco control advocates to influence public debates, and the governmental agenda, (3) the critical contribution of a coalition of GPHAs pooling resources to address both the sanitary and economic aspects of the legislation while countering the opposition's strategy, and (4) the failure of the opponents to present an unified voice on the definition of the tobacco policy. This study illustrates the merits of applying a policy-change model to grasp the complexity of the process. Our findings call for the development of permanent policy analysis capabilities within public health agencies and for a broader scrutiny of the non-health-related dimensions of policy debates.

Reciprocal inhibition of Cd(2+) and Ca(2+) uptake in human intestinal crypt cells for voltage-independent Zn-activated pathways.

Cadmium-Ca-Zn interactions for uptake have been studied in human intestinal crypt cells HIEC. Our results failed to demonstrate any significant cross-inhibition between Cd and Ca uptake under single metal exposure conditions. However, they revealed a strong reciprocal inhibition for a Zn-stimulated mechanism of transport. Optimal stimulation was observed under exposure conditions that favor an inward-directed Zn gradient, suggesting activation by extracellular rather than intracellular Zn. The effect of Zn on the uptake of Ca was concentration-dependent, and zinc-induced stimulation of Cd uptake resulted in a 3- and 5.8-fold increase in the K(m) and V(max) values, respectively. Neither basal nor Zn-stimulated Ca uptakes were sensitive to membrane depolarization. However, the stimulated component of uptake was inhibited by the trivalent cations Gd(3+), and La(3+) and to a lesser extent by Mg(2+) and Ba(2+). RT-PCR analysis as well as uptake measurement performed with extracellular ATP and/or suramin do not support the involvement of purinergic P2X receptor channels. Uptake and fluorescence data led to the conclusion that Zn is unlikely to trigger Ca influx in response to Ca release from thapsigargin-sensitive intracellular pools. Our data show that Zn may potentiate Cd accumulation in intestinal crypt cells through mechanism that still needs to be clarified.

Why and How Political Science Can Contribute to Public Health? Proposals for Collaborative Research Avenues.

Written by a group of political science researchers, this commentary focuses on the contributions of political science to public health and proposes research avenues to increase those contributions. Despite progress, the links between researchers from these two fields develop only slowly. Divergences between the approach of political science to public policy and the expectations that public health can have about the role of political science, are often seen as an obstacle to collaboration between experts in these two areas. Thus, promising and practical research avenues are proposed along with strategies to strengthen and develop them. Considering the interdisciplinary and intersectoral nature of population health, it is important to create a critical mass of researchers interested in the health of populations and in healthy public policy that can thrive working at the junction of political science and public health.

Relativistic deflection of background starlight measures the mass of a nearby white dwarf star.

Gravitational deflection of starlight around the Sun during the 1919 total solar eclipse provided measurements that confirmed Einstein's general theory of relativity. We have used the Hubble Space Telescope to measure the analogous process of astrometric microlensing caused by a nearby star, the white dwarf Stein 2051 B. As Stein 2051 B passed closely in front of a background star, the background star's position was deflected. Measurement of this deflection at multiple epochs allowed us to determine the mass of Stein 2051 B-the sixth-nearest white dwarf to the Sun-as 0.675 ± 0.051 solar masses. This mass determination provides confirmation of the physics of degenerate matter and lends support to white dwarf evolutionary theory.

Characterization of cadmium uptake in human intestinal crypt cells HIEC in relation to inorganic metal speciation.

Cadmium (Cd) uptake was studied under inorganic exposure conditions in normal human intestinal crypt cells HIEC. The uptake time course of 0.3 microM Cd in a serum-free chloride medium was analyzed according to a first order equation with rapid initial (U0) and maximal (Umax) accumulation values of 14.1+/-1.4pmol/mgprotein and 41.4+/-2.0 pmol/mgprotein, respectively. The presence of a 300-fold excess of unlabeled Cd dramatically decreased tracer uptake, showing the involvement of specific mechanism(s) of transport. Our speciation studies revealed the preferential uptake of the free ion Cd2+, but also suggested that CdCln(2-n) species may contribute to Cd accumulation. Specific mechanisms of transport of very high and similar affinity (Km approximately 5 microM) have been characterized under both chloride and nitrate exposure conditions, but a two-fold higher capacity (Vmax) was estimated in the nitrate medium used to increase [Cd2+] over chlorocomplex formation. A clear inhibition of 109Cd uptake was observed at external acidic pH under both exposure media. An La-inhibitible 46% increase in 109Cd uptake was obtained in nominally Ca-free nitrate medium, whereas Zn provided additional inhibition. These results show different kinetic parameters for Cd uptake as a function of inorganic metal speciation. Cd2+ uptake would not involve the H+-coupled symport NRAMP2 but would be related instead to the Ca and/or Zn pathways. Because proliferative crypt cells play a critical role in the renewal process of the entire intestinal epithelium, studies on the impact of Cd on HIEC cell functions clearly deserve further investigation.

Fighting a tobacco-tax rollback: a political analysis of the 1994 cigarette contraband crisis in Canada.

We identify factors that led a regional government (Quebec, Canada) to opt for a reduction of its tobacco tax to combat tobacco smuggling. Then we explore the fallout of Quebec's tobacco-tax rollback on its tobacco control policy. We conducted qualitative research using a case-study design and multiple sources of data. We applied the Advocacy Coalition Framework in respect of data collection and analysis. Advocates of the tobacco-tax rollback framed the contraband problem in a way that won the support of an array of actors. However, anti-tobacco activists succeeded in convincing the government to invest more in tobacco control. The new resources were instrumental in enhancing the activists' ability to promote legislative measures. Our approach sheds light on the tobacco industry's strategy to have governments reducing their tobacco tax. Quebec offers an example of how tobacco control activists can transform defeat into the cornerstone of a comprehensive tobacco control policy.

[Integrating prevention and promotion in health systems: four realities, diverse similarities]. / L'intégration de la prévention et de la promotion dans les systèmes de santé: quatre réalités, plusiers similitudes.

The Forum Dialogue on national health systems which took place as a satellite meeting of the 2nd International Conference on Local and Regional Health Programmes compared four countries (Brazil, France, Switzerland and Canada) sustain "conditions to integrate prevention and promotion in health systems". Despite the diversity of the four systems presented, several similarities regarding difficulties faced and achievements obtained in the integration process have been extracted, which has allowed highlighting three perspectives of action. It is suggested that prevention and promotion can be integrated into health systems by mobilising the population and health professionals towards prevention, but with the condition that the promotion and prevention sector increase its credibility by developing practices of quality, organisation, discourse, and prevention practices adjusted to the health care context. Finally, exchange between the countries on this subject is the way forward to nourish the thinking and support each other to obtain this desired integration.

[Primary health care and responsibilities of public health in 6 countries of Europe and North America: a pilot study]. / Atencion primaria y responsabilidades de salud pública en seis países de Europa y América del Norte: un estudio piloto.

BACKGROUND: Rapidly occurring changes within the health care systems are creating an opportunity to re-orient the relationships between their different sectors. In order to know the locus of responsibility for various types of preventive activities, we undertook an inquiry on eight areas in six countries from Europe and North America. METHODS: An inquiry among experts based on a matrix which arrayed the type of preventive health services against the target population. Eight clinical conditions were identified (childhood immunizations; adult influenza vaccination; mammography screening, tuberculosis screening, hypertension screening. PKU screening, HIV screening, and osteoporosis testing) trying to know their target population and the locus of responsibility for setting of policy, level to contact individuals for testing, follow-up of people with abnormal tests and maintenance of their medical records. RESULTS: This pilot study showed very little results coincidence either within the eight surveyed areas or across them. There was no regular pattern for the preventive activities studied among the different countries, neither according to the type of health system, nor to the primary health care orientation of the different systems. CONCLUSIONS: There was a limited consensus in the activities studied concerning the best mode of doing public health interventions for personal health services.

Methodological issues in analyzing small populations using CCHS cycles based on the official language minority studies.

Statistical analyses for small populations or small domains of interest can be challenging. To obtain reliable estimates, only very large surveys such as the Canadian Community Health Survey can be considered. However, despite its good geographical and temporal coverage, the analysis of small populations in smaller regions (e.g., health regions) and in regards to specific health issues remains challenging. We will look at the methodological issues in analysis of small populations in relation to sampling and non-sampling survey errors that affect the precision and accuracy of the estimates. Francophone minorities in Canada will be used to illustrate the issues throughout the paper.