La distribution ‘juste’ de la signature savante dans les collaborations de recherche multidisciplinaire en sciences de la santé

L’auteur qui appose son nom à une publication universitaire sera reconnu pour sa contribution à la recherche et devra également en assumer la responsabilité. Il existe divers types d’agencements pouvant être utilisés afin de nommer les auteurs et souligner l’ampleur de leur contribution à ladite recherche. Par exemple, les auteurs peuvent être nommés en ordre décroissant selon l’importance de leurs contributions, ce qui permet d’allouer davantage de mérite et de responsabilité aux premiers auteurs (à l’instar des sciences de la santé) ou bien les individus peuvent être nommés en ordre alphabétique, donnant une reconnaissance égale à tous (tel qu’on le note dans certains domaines des sciences sociales). On observe aussi des pratiques émergeant de certaines disciplines ou des champs de recherche (tel que la notion d’auteur correspondant, ou directeur de recherche nommé à la fin de la liste d’auteurs). En science de la santé, lorsque la recherche est de nature multidisciplinaire, il existe différentes normes et pratiques concernant la distribution et l’ordre de la signature savante, ce qui peut donner lieu à des désaccords, voire à des conflits au sein des équipes de recherche. Même si les chercheurs s’entendent pour dire que la signature savante devrait être distribué de façon ‘juste’, il n’y a pas de consensus sur ce que l’on qualifie de ‘juste’ dans le contexte des équipes de recherche multidisciplinaire. Dans cette thèse, nous proposons un cadre éthique pour la distribution juste de la signature savante dans les équipes multidisciplinaires en sciences de la santé. Nous présentons une critique de la documentation sur la distribution de la signature savante en recherche. Nous analysons les enjeux qui peuvent entraver ou compliquer une distribution juste de la signature savante tels que les déséquilibres de pouvoir, les conflits d’intérêts et la diversité de cultures disciplinaires. Nous constatons que les normes internationales sont trop vagues; par conséquent, elles n’aident pas les chercheurs à gérer la complexité des enjeux concernant la distribution de la signature savante. Cette limitation devient particulièrement importante en santé mondiale lorsque les chercheurs provenant de pays développés collaborent avec des chercheurs provenant de pays en voie de développement. Afin de créer un cadre conceptuel flexible en mesure de s’adapter à la diversité des types de recherche multidisciplinaire, nous proposons une approche influencée par le Contractualisme de T.M. Scanlon. Cette approche utilise le respect mutuel et la force normative de la raison comme fondation, afin de justifier l’application de principes éthiques. Nous avons ainsi développé quatre principes pour la distribution juste de la signature savante en recherche: le mérite, la juste reconnaissance, la transparence et la collégialité. Enfin, nous proposons un processus qui intègre une taxonomie basée sur la contribution, afin de délimiter les rôles de chacun dans le projet de recherche. Les contributions peuvent alors être mieux comparées et évaluées pour déterminer l’ordre de la signature savante dans les équipes de recherche multidisciplinaire en science de la santé.

The Broader Impact of Disability Research: Aligning Public Policy with the Experiences of People with Disabilities and Healthcare Providers

Thesis (Ph.D.)--University of Washington, 2016-07

Ecological health analysis of Caspian marine environment based on the diversity and distribution pattern of meiofauna in the Mazandaran Province, Caspian Sea

Biodiversity and distribution of benthic meiofauna in the sediments of the Southern Caspian Sea (Mazandaran) was studied in order to introducing and determining of their relationship with the environmental factors. From 12 stations (ranging in depths 5, 10, 20 and 50 meters), sediment samples were gathered in 6 months (2012). Environmental factors of water near the bottom including temperature, salinity, dissolved oxygen and pH were measured during sampling with CTD and grain size and total organic matter percentage and calcium carbonate were measured in laboratory. In different months, the average water temperature (9.52-23.93), dissolved oxygen (7.71-10.53 mg/L), salinity (10.57±0/07 and 10.75±0/04 ppt), pH (7.44±0/29 and 7.41±0/22), EC (17.97±0/12 and 18.30±0/04μs/cm2), TDS (8.92±0/04 and 9.14±0/02 mg/L), total organic matter (5.83±1/43 and 6.25±0/97%) and calcium carbonate (2.36±0/36 and 1.68±0/19%) were measured respectively. Structure of the sediment samples mostly consisted of fine sand; very fine sand, silt and clay. From the 4 group animals (Foraminifera, Crustacea, Worms and Mollusca), there were identified 40species belong to 29 genera of 25 families. The cosmopolitan foraminifer, Ammonia beccarii caspica, was common in all sampling stations. Result showed that depth was important factor on distribution of meiofauna. Most density of foraminifera and crustacean was observed in depth of 20m and for mollusca and worms observed in 5m. Shannon diversity index decreased with depth that showed in shallow water diversity was higher than deep water. Mean of maximum and minimum Shannon index was obsorvers in depth of 5m and 50 m that was measured in order 0.93 and 0.43. Account of Shannon index showed that this area is under pressure. Account of peioleo index showed distribution in this area was not steady.

Selenium and Mercury in the Brazilian Amazon: Opposing Influences on Age-Related Cataracts

BACKGROUND: Age-related cataracts (ARCs) are an important cause of blindness in developing countries. Although antioxidants may be part of the body's defense to prevent ARC, environmental contaminants may contribute to cataractogenesis. In fish-eating populations of the lower Tapajos region, elevated exposure to mercury (Hg) has been reported, and blood levels of selenium (Se) range from normal to very high (> 1,000 mu g/L). OBJECTIVES: We examined ARCs in relation to these elements among adults (>= 40 years of age) from 12 riverside communities. METHODS: Participants (n = 211) provided blood samples and underwent an extensive ocular examination. Inductively coupled plasma mass spectrometry was used to assess Hg and Se in blood and plasma. RESULTS: One-third (n = 69; 32.7%) of the participants had ARC. Lower plasma Se (P-Se; < 25th percentile, 110 mu g/L) and higher blood Hg (B-Hg; >= 25th percentile, 25 mu g/L) were associated with a higher prevalence odds ratio (POR) of ARC [adjusted POR (95% confidence interval), 2.69 (1.11-6.56) and 4.45 (1.43-13.83), respectively]. Among participants with high P-Se, we observed a positive but nonsignificant association with high B-Hg exposure, whereas among those with low B-Hg, we observed no association for P-Se. However, compared with the optimum situation (high P-Se, low B-Hg), the POR for those with low P-Se and high B-Hg was 16.4 (3.0-87.9). This finding suggests a synergistic effect. CONCLUSION: Our results suggest that persons in this population with elevated Hg, the cataractogenic effects of Hg may be offset by Se. Because of the relatively small sample size and possible confounding by other dietary nutrients, additional studies with sufficient power to assess multiple nutrient and toxic interactions are required to confirm these findings.

The International Collaboration on Air Pollution and Pregnancy Outcomes: Initial Results

BACKGROUND: The findings of prior studies of air pollution effects on adverse birth outcomes are difficult to synthesize because of differences in study design. OBJECTIVES: The International Collaboration on Air Pollution and Pregnancy Outcomes was formed to understand how differences in research methods contribute to variations in findings. We initiated a feasibility study to a) assess the ability of geographically diverse research groups to analyze their data sets using a common protocol and b) perform location-specific analyses of air pollution effects on birth weight using a standardized statistical approach. METHODS: Fourteen research groups from nine countries participated. We developed a protocol to estimate odds ratios (ORs) for the association between particulate matter <= 10 mu m in aerodynamic diameter (PM(10)) and low birth weight (LBW) among term births, adjusted first for socioeconomic status (SES) and second for additional location-specific variables. RESULTS: Among locations with data for the PM(10) analysis, ORs estimating the relative risk of term LBW associated with a 10-mu g/m(3) increase in average PM(10) concentration during pregnancy, adjusted for SES, ranged from 0.63 [95% confidence interval (CI), 0.30-1.35] for the Netherlands to 1.15 (95% CI, 0.61-2.18) for Vancouver, with six research groups reporting statistically significant adverse associations. We found evidence of statistically significant heterogeneity in estimated effects among locations. CONCLUSIONS: Variability in PM(10)-LBW relationships among study locations remained despite use of a common statistical approach. A more detailed meta-analysis and use of more complex protocols for future analysis may uncover reasons for heterogeneity across locations. However, our findings confirm the potential for a diverse group of researchers to analyze their data in a standardized way to improve understanding of air pollution effects on birth outcomes.

Traffic-Related Air Pollution and Perinatal Mortality: A Case-Control Study

BACKGROUND: Ambient levels of air pollution may affect the health of children, as indicated by studies of infant and perinatal mortality. Scientific evidence has also correlated low birth weight and preterm birth, which are important determinants of perinatal death, with air pollution. However, most of these studies used ambient concentrations measured at monitoring sites, which may not consider differential exposure to pollutants found at elevated concentrations near heavy-traffic roadways. OBJECTIVES: Our goal was to examine the association between traffic-related pollution and perinatal mortality. METHODS: We used the information collected for a case-control study conducted in 14 districts in the City of Sao Paulo, Brazil, regarding risk factors for perinatal deaths. We geocoded the residential addresses of cases (fetal and early neonatal deaths) and controls (children who survived the 28th day of life) and calculated a distance-weighted traffic density (DWTD) measure considering all roads contained in a buffer surrounding these homes. RESULTS: Logistic regression revealed a gradient of increasing risk of early neonatal death with higher exposure to traffic-related air pollution. Mothers exposed to the highest quartile of the DWTD compared with those less exposed exhibited approximately 50% increased risk (adjusted odds ratio = 1.47; 95% confidence interval, 0.67-3.19). Associations for fetal mortality were less consistent. CONCLUSIONS: These results suggest that motor vehicle exhaust exposures may be a risk factor for perinatal mortality.

Genotoxic potential generated by biomass burning in the Brazilian Legal Amazon by Tradescantia micronucleus bioassay: a toxicity assessment study

Background: The Brazilian Amazon has suffered impacts from non-sustainable economic development, especially owing to the expansion of agricultural commodities into forest areas. The Tangara da Serra region, located in the southern of the Legal Amazon, is characterized by non-mechanized sugar cane production. In addition, it lies on the dispersion path of the pollution plume generated by biomass burning. The aim of this study was to assess the genotoxic potential of the atmosphere in the Tangara da Serra region, using Tradescantia pallida as in situ bioindicator. Methods: The study was conducted during the dry and rainy seasons, where the plants were exposed to two types of exposure, active and passive. Results: The results showed that in all the sampling seasons, irrespective of exposure type, there was an increase in micronucleus frequency, compared to control and that it was statistically significant in the dry season. A strong and significant relationship was also observed between the increase in micronucleus incidence and the rise in fine particulate matter, and hospital morbidity from respiratory diseases in children. Conclusions: Based on the results, we demonstrated that pollutants generated by biomass burning in the Brazilian Amazon can induce genetic damage in test plants that was more prominent during dry season, and correlated with the level of particulates and elevated respiratory morbidity.

Stress at Work among Electric Utility Workers

In the last decades there was an increase in stress at work and its effects on workers' health. These issues are still little studied in the electric utility sector. This study aims to evaluate factors associated with stress at work and to verify its associations with health status among workers of an electric company in Sao Paulo State, Brazil. A cross-sectional study was conducted with 474 subjects (87.5% of the eligible workers). Data were collected using self-reported questionnaires. A descriptive analysis, a multiple linear hierarchical regression analysis and a correlation analysis were performed. The majority of participants were males (91.1%) and the mean age was 37.5 yr. The mean score of stress level was 2.3 points (scale ranging from 1.0 to 5.0). Hierarchical multiple analyses showed that: regular practice of physical activities (p=0.025) and individual monthly income (p=0.002) were inversely associated with stress level; BMI was marginally associated with the stress level (p=0.074). The demographic characteristics were not associated with stress. Stress at work was significantly associated with physical and mental health status (p<0.001). To improve health of electric utility workers, actions are suggested to decrease stress by remuneration and an appropriate practice of physical activity aiming reduction of BMI.

Artificial Lighting as a Vector Attractant and Cause of Disease Diffusion

BACKGROUND: Traditionally, epidemiologists have considered electrification to be a positive factor. In fact, electrification and plumbing are typical initiatives that represent the integration of an isolated population into modern society, ensuring the control of pathogens and promoting public health. Nonetheless, electrification is always accompanied by night lighting that attracts insect vectors and changes people's behavior. Although this may lead to new modes of infection and increased transmission of insect-borne diseases, epidemiologists rarely consider the role of night lighting in their surveys. OBJECTIVE: We reviewed the epidemiological evidence concerning the role of lighting in the spread of vector-borne diseases to encourage other researchers to consider it in future studies. DISCUSSION: We present three infectious vector-borne diseases-Chagas, leishmaniasis, and malaria-and discuss evidence that suggests that the use of artificial lighting results in behavioral changes among human populations and changes in the prevalence of vector species and in the modes of transmission. CONCLUSION: Despite a surprising lack of studies, existing evidence supports our hypothesis that artificial lighting leads to a higher risk of infection from vector-borne diseases. We believe that this is related not only to the simple attraction of traditional vectors to light sources but also to changes in the behavior of both humans and insects that result in new modes of disease transmission. Considering the ongoing expansion of night lighting in developing countries, additional research on this subject is urgently needed.

Arsenic and Chromium in Brazilian Agricultural Supplies

Arsenic (As) and chromium (Cr) contents were measured in agricultural supplies used at different farms in Sao Paulo State, Brazil. The highest mass fractions of As were found in thermophosphates, reaching levels of 4 mg/kg. The highest mass fractions of Cr (21 g/kg) were found in calcium magnesium silicate, while the thermophosphates also presented high values reaching approximately 1 g/kg. The levels of As were within Brazilian guidelines, but the values of Cr in thermophosphates exceeded the levels permitted in Brazil. The As content in fertilizers may be considered safe (5 mg/kg) in terms of environmental pollution. However, the Cr content in calcium magnesium silicate following continuous use may constitute a significant problem in Brazil due to potentially increasing levels of this metal in soils.

Mineralization and degradation of glyphosate and atrazine applied in combination in a Brazilian Oxisol

The aim of this study was to investigate the behavior of the association between atrazine and glyphosate in the soil through mineralization and degradation tests. Soil treatments consisted of the combination of a field dose of glyphosate (2.88 kg ha-1) with 0, 1/2, 1 and 2 times a field dose of atrazine (3.00 kg ha-1) and a field dose of atrazine with 0, 1/2, 1 and 2 times a field dose of glyphosate. The herbicide mineralization rates were measured after 0, 3, 7, 14, 21, 28, 35, 42, 49, 56 and 63 days of soil application, and degradation rates after 0, 7, 28 and 63 days. Although glyphosate mineralization rate was higher in the presence of 1 (one) dose of atrazine when compared with glyphosate alone, no significant differences were found when half or twice the atrazine dose was applied, meaning that differences in glyphosate mineralization rates cannot be attributed to the presence of atrazine. On the other hand, the influence of glyphosate on atrazine mineralization was evident, since increasing doses of glyphosate increased the atrazine mineralization rate and the lowest dose of glyphosate accelerated atrazine degradation.

Elevated blood lead levels in a riverside population in the Brazilian Amazon

Lead (Pb) is recognized as one of the most toxic metals. Sources of Pb exposure have been widely documented in North America, and the removal of Pb additives from gasoline was reflected in a dramatic lowering of blood Pb concentration. In Latin America, the removal of Pb from gasoline resulted in decreased exposure, but Pb levels in many areas remain high due to occupational and environmental sources of exposure. While many of the Pb sources have been identified (mining, industries, battery recycling, lead-based paint, ceramics), new ones occasionally crop up. Here we report on blood Pb (B-Pb) levels in remote riverside communities of the Brazilian Amazon. Blood Pb (B-Pb) levels were determined in 448 persons from 12 villages of the Lower Tapajos River Basin, Par, Brazil. Socio-demographic and dietary information, as well as occupational, residential and medical history was collected using an interview-administered questionnaire. B-Pb, measured by ICP-MS, showed elevated concentrations. Mean B-Pb was 13.1 mu g/dL +/- 8.5, median B-Pb was 11.2 mu g/dL and ranged from 0.59 to 48.3 mu g/dL. Men had higher B-Pb compared to women (median: 15.3 mu g/dL vs 7.9 mu g/dL respectively). B-Pb increased with age for women, while it decreased for men. For both genders, B-Pb decreased with education. There were significant differences between villages. Exploratory analyses, using linear partition models, showed that for men B-Pb was lower among those who were involved in cattle-raising, and higher among those who hunted, farmed and fished. The distribution profile of B-Pb directed us towards artisanal transformation of manioc to flour (farinha), which requires heating in a large metal pan, with stirring primarily done by young men. In the village with the highest B-Pb, analysis of Pb concentrations (dry weight) of manioc (prior to transformation) and farinha (following transformation) from 6 houses showed a tenfold increase in Pb concentration (mean: 0.017 +/- 0.016 to 0.19 +/- 0.10 mu g/g). This was confirmed in one of these villages where we sampled manioc paste Oust before roasting) and the roasted farinha (0.05 mu g/g vs 0.20 mu g/g). While there may be other sources (ammunition, sinkers for fishing nets), the high concentrations in farinha, a dietary staple, assuredly makes an important contribution. Further action needs to reduce Pb sources in this region. (C) 2009 Elsevier Inc. All rights reserved.

A plateau detected in lead accumulation in subsurface deciduous enamel from individuals exposed to lead may be useful to identify children and regions exposed to higher levels of lead

In a previous study, we showed 4 times more lead in surface deciduous enamel (1.9-5.9 mu m) of a notoriously contaminated area (Bauru, Sao Paulo State, Brazil) in comparison to samples from a region with no lead contamination described (Ribeirao Preto, Sao Paulo State, Brazil). The samples from the more superficial enamel (1.9-3.18 mu m) showed higher amounts of lead and the highest variability, while in the subsurface enamel (3.18-5.9 mu m) a plateau in lead content was detected in children living in the contaminated environment (around 600 mu g/g). Here we expand our previous study, and use only samples obtained from subsurface enamel (Ribeirao Preto, n = 186; Bauru, n = 20). We tried to distinguish regions with more children with lead above the threshold of 600 mu g/g of lead in enamel. We tested whether differences in the percentage of children with ""high"" lead (>= 600 mu g/g) could be observed among the different Kindergartens studied in Ribeirao Preto. We also tested whether these results were different from the ones provided by conventional comparison of the data. Ribeirao Preto showed almost 4 times less lead than Bauru (p < 0.0001), and a statistically significant difference was found only in Ribeirao Preto between Kindergarten 2 and 5 (p<0.01). Twelve percent of the children from Ribeirao Preto had ""high"" lead, while 55% of the children from Bauru did so. However, when we looked at the percentages of children with ""high"" lead in each Kindergarten, and compared them, a whole new picture emerged, in which we could see children with ""high"" lead concentrated mainly in 3 Kindergartens from Ribeirao Preto, with Kindergarten 5 with 33% of the children with ""high"" lead, being statistically different from all Kindergartens, except 4 and 6. The threshold of 600 mu g/g of lead in subsurface enamel was tentatively settled here after the plateau seen in exposed children, and enabled us to identify locations with more children exposed to a higher amount of lead. (C) 2008 Elsevier Inc. All rights reserved.

Biomarkers of selenium status in the amazonian context: Blood, urine and sequential hair segments

Selenium (Se) is an essential element and deficit or excess of dietary Se is associated with health disorders. Relatively elevated Se levels have been reported in the Brazilian Amazon, where there are also important annual variations in the availability of different foods. The present study was conducted among six riparian communities of the Tapajos River to evaluate seasonal variations in blood and sequential hair cm Se concentrations, and to examine the relationships between Se in blood and hair, and blood and urine. Two cross-sectional studies were conducted, at the descending water (DWS, n = 259) and the rising water (RWS, n = 137) seasons, with repeated measures for a subgroup (n = 112). Blood Se (B-Se), hair Se (H-Se) and urine Se (U-Se) were determined. Match-paired analyses were used for seasonal comparisons and the method of best fit was used to describe the relationships between biomarkers. B-Se levels presented a very large range (142-2447 mu g/l) with no overall seasonal variation (median 284 and 292 mu g/l, respectively). Sequential analysis of 13 cm hair strands showed significant variations over time: Se concentrations at the DWS were significantly lower compared with the rising water season (medians: 0.7 and 0.9 mu g/g; ranges: 0.2-4.3 mu g/g and 0.2-5.4 mu g/g, respectively). At both seasons, the relationships between B-Se and H-Se were linear and highly significant (r(2) = 67.9 and 63.6, respectively), while the relationship between B-Se and U-Se was best described by a sigmoid curve. Gender, age, education and smoking did not influence Se status or biomarker relationships. Variations in H-Se suggest that there may be seasonal availability of Se sources in local food. For populations presenting a large range and/or elevated Se exposure, sequential analyses of H-Se may provide a good reflection of variations in Se status.

El Nino and arboviral disease prediction

Recent El Nino events have stimulated interest in the development of modeling techniques to forecast extremes of climate and related health events. Previous studies have documented associations between specific climate variables (particularly temperature and rainfall) and outbreaks of arboviral disease. In some countries, such diseases are sensitive to Fl Nino. Here we describe a climate-based model for the prediction of Ross River virus epidemics in Australia. From a literature search and data on case notifications, we determined in which years there were epidemics of Ross River virus in southern Australia between 1928 and 1998. Predictor variables were monthly Southern Oscillation index values for the year of an epidemic or lagged by 1 year. We found that in southeastern states, epidemic years were well predicted by monthly Southern Oscillation index values in January and September in the previous year. The model forecasts that there is a high probability of epidemic Ross River virus in the southern states of Australia in 1999. We conclude that epidemics of arboviral disease can, at least in principle, be predicted on the basis of climate relationships.