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Recent genomic study on Greenland halibut Reinhardtius hippoglossoides throughout the Northwest Atlantic revealed genetic differentiation between the Gulf of St. Lawrence and the remainder of the Northwest Atlantic. Knowledge of migration and thus connectivity among fish populations is key to understanding the stock dynamics of commercial species and establishing effective management strategies. In this study, we use otolith microchemistry to assess the population structure and define more clearly the potential connectivity of Greenland halibut among Saguenay Fjord, the Estuary, and the Gulf of St. Lawrence (EGSL) and outside this system. Otolith margins and cores were analyzed to determine the elemental fingerprints. The margin elemental fingerprints (Mg, Sr, and Ba) were used to infer spatial differentiation, and quadratic discriminant analysis resulted in an overall reclassification success of fish to their capture site of 59%. The core elemental fingerprints indicated three chemically distinct juvenile sources, suggesting high connectivity in the EGSL supporting the St. Lawrence Estuary as a main nursery. Our results also suggest that one of these three sources has a smaller contribution relative to the other sites. Key words: Reinhardtius hippoglossoides, otolith microchemistry, elemental fingerprint, natal sources, stock contribution, 1. Introduction Coastal communities depend on the exploitation of fishery resources to support their economies. Sustainable fishing practices must be used by the fishing industry to limit the risk of [...]

Carbon dioxide rebreathing (CO2 rebreathing) significantly influences respiratory drive and the work of breathing during BiPAP ventilation. We analyzed CO2 movement during BiPAP ventilation to find a method of real time detection of CO2 rebreathing without the need of CO2 concentration measurement sampled from the circuit (method expensive and not routinely used). Observational study during routine care in 15 bed university hospital ICU. At 18 patients who required BiPAP ventilation, intubated or during noninvasive ventilation, during weaning period airflow, pressure and CO2 concentration signals were registered on both sides of venting port and 17 respiratory parameters were measured or calculated for each of 4747 respiratory cycles analyzed. Based on CO2 movement (expiration–inspiration sequences) 3 types of cycle were identified, type I and II do not induce rebreathing but type III does. To test differences between the 3 types ANOVA, t-tests, and canonical discriminant analysis (CDA) were used. Then a multilayer perceptron (MLP) network, a type of artificial neural network, using the above parameters (excluding CO2 concentration) was applied to automatically identify the three types of respiratory cycles. Of the 4747 respiratory cycles, 1849 were type I, 1545 type II, and 1353 type III. ANOVA and t-tests showed significant differences between the types of respiratory cycles. CDA confirmed a correct apportionment of 93.9% of the cycles; notably, of 97.9% of type III. MLP automatically classified the respiratory cycles into the three types with 98.8% accuracy. Three types of respiratory cycles could be distinguished based on CO2 movement during BiPAP ventilation. Artificial neural networks can be used to automatically detect respiratory cycle type III, the only inducing CO2 rebreathing. [ABSTRACT FROM AUTHOR]

Purpose Physicians play an important role in strategies to control health care spending. Being aware of the cost of prescriptions is surely the first step to incorporating cost-consciousness into medical practice. The aim of this study was to evaluate current intensivists' knowledge of the costs of common prescriptions and to identify factors influencing the accuracy of cost estimations. Methods Junior and senior physicians in 99 French intensive care units were asked, by questionnaire, to estimate the true hospital costs of 46 selected prescriptions commonly used in critical care practice. Results With an 83 % response rate, 1092 questionnaires were examined, completed by 575 (53 %) and 517 (47 %) junior and senior intensivists, respectively. Only 315 (29 %) of the overall estimates were within 50 % of the true cost. Response errors included a 14,756 ± 301 [euro] underestimation, i.e., -58 ± 1 % of the total sum (25,595 [euro]). High-cost drugs (>1000 [euro]) were significantly (p < 0.001) the most underestimated prescriptions (-67 ± 1 %). Junior grade physicians underestimated more costs than senior physicians (p < 0.001). Using multivariate analysis, junior physicians [odds ratio (OR), 2.1; 95 % confidence interval (95 % CI), 1.43-3.08; p = 0.0002] and female gender (OR, 1.4; 95 % CI, 1.04-1.89; p = 0.02) were both independently associated with incorrect cost estimations. Conclusions ICU physicians have a poor awareness of prescriptions costs, especially with regards to high-cost drugs. Considerable emphasis and effort are still required to integrate the cost-containment problem into the daily prescriptions in ICUs., Author(s): Romain Hernu [sup.1], Martin Cour [sup.1] [sup.2], Sylvie de la Salle [sup.3], Dominique Robert [sup.1], Laurent Argaud [sup.1] [sup.2] [sup.4] Author Affiliations: (1) grid.412180.e, 0000000121984166, Service de Réanimation Médicale, [...]

Northern sand lance (Ammodytes dubius) are essential forage fish in most offshore, temperate-to-polar waters on the Northwest Atlantic shelf (NWA), but their population structure and genetic separation from the American sand lance (A. americanus) remain unresolved. We assembled a reference genome for A. dubius (first in the Ammodytidae) and then used low-coverage whole genome sequencing on 262 specimens collected across the species distribution (Mid-Atlantic Bight to Greenland) to quantify genetic differentiation between geographic regions based on single nucleotide polymorphisms. We found strong separation between A. dubius from locations north and south of the Scotian Shelf, largely due to massive genetic differentiation spanning most of chromosomes 21 and 24. Genetic distance increased with geographic distance in the smaller southern cluster but not in the larger northern cluster, where genetic homogeneity appeared across large geographic distances (>103 km). The two genetic clusters coincide with a clear break in winter sea surface temperature, suggesting that differential offspring survival, rather than limited transport, causes a break in realized connectivity. Nuclear and mitochondrial DNA both clearly delineated A. dubius from A. americanus , thereby confirming a species boundary through spatial niche partitioning into inshore (A. americanus) and offshore (A. dubius) sand lance species on the NWA. [ABSTRACT FROM AUTHOR]

Johan Hjort's "critical period" hypothesis, which postulates that year‐class strength is determined in the short period following the onset of exogenous feeding, has rarely been supported by empirical data. Instead, the current understanding is that recruitment is determined by cumulative mortality throughout early life. Recent studies relied on the measure of growth autocorrelation derived from otolith daily increment widths to test the link between growth rate achieved during the post‐hatch period and during subsequent phases of the larval stage. Based on this approach, we revisit the role of larval growth in driving survival potential in three clupeoid species: Japanese sardine Sardinops melanostictus, Japanese anchovy Engraulis japonicus, and Pacific round herring Etrumeus micropus throughout the larval stage, using a combination of published datasets of otolith increment widths. Strong growth autocorrelation was detected for all three species throughout the larval stage, suggesting that initial growth determines to some extent growth rates achieved later in life. The extent of autocorrelation was reduced in sardine relative to anchovy and round herring at older ages. This interspecific difference could be attributed to differences in sensitivity to variability of environmental factors such as water temperature and food availability. The present findings suggest that the effect of early growth rate persists into later life stages for driving survival potential, which could reconcile the classic concept of "critical period" and the current "growth–survival" paradigm. [ABSTRACT FROM AUTHOR]