Elevated Levels of Trace Elements in Cores of Otoliths and Their Potential for Use as Natural Tags

Variation in the chemical composition of fish otoliths has been used in recent years to address a range of ecological questions, including levels of stock mixing, variation in habitat use, and rates of larval exchange. While some of these questions have been answered with varying success, the degree to which discrete populations are connected via larval exchange remains unknown. To identify larval sources using natural variation in otolith chemistry, we must distinguish and measure the chemical composition of the otolith core, the portion of the otolith formed at the spawning site. Using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS), we found that the core regions of otoliths from 6 different species of fishes were highly enriched in manganese (Mn), and elevated in magnesium (Mg) and barium (Ba), relative to adjacent regions of the otolith. These patterns were consistent for species drawn from different taxonomic groups, which inhabit temperate and tropical regions, are found in marine and freshwater, and utilize a variety of spawning modes. Variation among species in Mn concentration in the core also corresponds to maternal investment, measured by egg size. These data suggest that core enrichment may be a general characteristic of otoliths, and that the chemical composition of the otolith core is fundamentally different from other regions of the otolith. The localized elemental enrichment of the core underscores the importance of methods that analyze the core region in small, discrete samples if otolith chemistry is used to address questions of larval exchange among populations

Transformation du programme de baccalauréat en pharmacie de l’Université de Montréal en un programme de doctorat de 1er cycle en pharmacie (Première partie)

Résumé Objectif : À l’automne 2001, le Conseil de la Faculté de pharmacie de l’Université de Montréal confia à son Comité des études le mandat de planifier, d’organiser et de réaliser les travaux de révision du programme de baccalauréat en pharmacie, en concertation avec les divers intervenants du milieu de pratique. Mise en contexte : Pendant plus d’un an, un souscomité délégué par le Comité des études a évalué la pertinence et la faisabilité de modifier l’actuel programme de baccalauréat. Les travaux du sous-comité se sont faits en concertation avec les divers intervenants de la profession, entre autres l’Ordre des pharmaciens du Québec, les principales associations professionnelles québécoises, la Faculté de pharmacie de l’Université Laval ainsi que les étudiants et le corps professoral de la Faculté. La pertinence de modifier le programme de baccalauréat en pharmacie se justifie par les éléments suivants : 1) l’évolution du système de santé vers l’interdisciplinarité et la continuité des soins, 2) les besoins non comblés de la population en matière d’utilisation de médicaments, 3) l’adaptation de la pratique de la pharmacie, 4) la formation requise pour combler ces besoins, et 5) le contexte des programmes de formation dans le domaine des sciences de la santé. Conclusion : Après analyse des modifications à apporter à l’actuel programme, le grade de doctorat professionnel de 1er cycle en pharmacie (Pharm. D.) s’est imposé comme la mention la plus pertinente pour les étudiants qui termineront ce programme. Abstract Objective: In the fall of 2001, the council of the Université de Montréal pharmacy faculty gave its curriculum committee the mandate of planning, organizing, and implementing the revision of the Bachelor of Pharmacy program. Context: For more than a year, the curriculum committee delegated a sub-committee to evaluate the relevance and feasibility of modifying the current Bachelor’s program. The work of the sub-committee was done in concert with various representatives involved in the profession along with (among others) the Québec Order of Pharmacists, the main Quebec professional associations, and the Université Laval faculty of pharmacy as well as students and professors of the faculty. The relevance of modifying the Bachelor’s program in pharmacy is justified by the following elements: 1) the evolution of the healthcare system towards a multidisciplinary approach and continuity of care, 2) unmet needs of the population with respect to medication use, 3) the necessary adaptation of pharmacy practice, 4) required training to answer these needs, and, 5) the context of training programs in the health sciences field. Conclusion: After analyzing modifications to be integrated in the actual program, the Doctorate degree at the undergraduate level (Pharm. D) became a necessary alternative for students to succesfully finish this training program. Key Words: Pharm.D., revision of Bachelor of Pharmacy progra

2008 Inter-laboratory Comparison Study of a Reference Material for Nutrients in Seawater

Autoclaved natural seawater collected in the North Pacific Ocean was used as a reference material for nutrients in seawater (RMNS) during an inter-laboratory comparison (I/C) study conducted in 2008. This study was a follow-up to previous studies conducted in 2003 and 2006. A set of six samples was distributed to each of 58 laboratories in 15 countries around the globe, and results were returned by 54 of those laboratories (15 countries). The homogeneities of samples used in the 2008 I/C study, based on analyses for three determinants, were improved compared to those of samples used in the 2003 and 2006 I/C studies. Results of these I/C studies indicate that most of the participating laboratories have an analytical technique for nutrients that is sufficient to provide data of high comparability. The differences between reported concentrations from the same laboratories in the 2006 and 2008 I/C studies for the same batch of RMNS indicate that most of the laboratories have been maintaining internal comparability for two years. Thus, with the current high level of performance in the participating laboratories, the use of a common reference material and the adaptation of an internationally accepted nutrient scale system would increase comparability among laboratories worldwide, and the use of a certified reference material would establish traceability. In the 2008 I/C study we observed a problem of non-linearity of the instruments of the participating laboratories similar to that observed among the laboratories in the 2006 I/C study. This problem of non-linearity should be investigated and discussed to improve comparability for the full range of nutrient concentrations. For silicate comparability in particular, we see relatively larger consensus standard deviations than those for nitrate and phosphate

A Quasi-Exclusive European Ancestry in the Senepol Tropical Cattle Breed Highlights the Importance of the slick Locus in Tropical Adaptation

Background: The Senepol cattle breed (SEN) was created in the early XXth century from a presumed cross between a European (EUT) breed (Red Poll) and a West African taurine (AFT) breed (N'Dama). Well adapted to tropical conditions, it is also believed trypanotolerant according to its putative AFT ancestry. However, such origins needed to be verified to define relevant husbandry practices and the genetic background underlying such adaptation needed to be characterized. Methodology/Principal Findings: We genotyped 153 SEN individuals on 47,365 SNPs and combined the resulting data with those available on 18 other populations representative of EUT, AFT and Zebu (ZEB) cattle. We found on average 89% EUT, 10.4% ZEB and 0.6% AFT ancestries in the SEN genome. We further looked for footprints of recent selection using standard tests based on the extent of haplotype homozygosity. We underlined i) three footprints on chromosome (BTA) 01, two of which are within or close to the polled locus underlying the absence of horns and ii) one footprint on BTA20 within the slick hair coat locus, involved in thermotolerance. Annotation of these regions allowed us to propose three candidate genes to explain the observed signals (TIAM1, GRIK1 and RAI14). Conclusions/Significance: Our results do not support the accepted concept about the AFT origin of SEN breed. Initial AFT ancestry (if any) might have been counter-selected in early generations due to breeding objectives oriented in particular toward meat production and hornless phenotype. Therefore, SEN animals are likely susceptible to African trypanosomes which questions the importation of SEN within the West African tsetse belt, as promoted by some breeding societies. Besides, our results revealed that SEN breed is predominantly a EUT breed well adapted to tropical conditions and confirmed the importance in thermotolerance of the slick locus. (Résumé d'auteur

Otolith elemental signatures reflect residency in coastal water masses

We examined variability in otolith chemistry of wild caught fish in relation to in situ temperature and salinity within the California Current System. Barium, magnesium, and iron from the most recent growth zone in otoliths differentiated pelagic juvenile shortbelly rockfish (Sebastes jordani) residing in water masses with distinct temperature and salinity properties from central and southern California spanning nearly 500 km of coastline. The 3-element signature also discriminated fish that resided in different water masses that were associated with mesoscale cyclonic eddy circulation in the Santa Barbara Channel. Variability in otolith chemistry reflected the spatial patterns of both horizontal gradients and vertical gradients in water mass properties related to circulation. Although we found that the concentrations of particular elements in otoliths were correlated to ambient temperature or salinity, we suggest that these parameters are more useful as an identifying signature of distinct water masses associated with unique otolith signatures rather than as factors directly affecting otolith chemistry. Other factors varying among the water masses or among the fish populations residing in the water masses may also affect otolith chemistry. We discuss how oceanographic phenomena associated with the 1997–1998 El Niño and the persistent, recirculating eddy in the Channel may have affected coastal ocean conditions and variation in otolith chemistry of fish in the study area