No abstract

The Salmoniform whole-genome duplication is hypothesized to have facilitated the evolution of anadromy, but little is known about the contribution of paralogs from this event to the physiological performance traits required for anadromy, such as salinity tolerance. Here, we determined when two candidate, salinity-responsive paralogs of the Na(+) , K(+) ATPase α subunit (α1a and α1b) evolved and studied their evolutionary trajectories and tissue-specific expression patterns. We found that these paralogs arose during a small-scale duplication event prior to the Salmoniform, but after the teleost, whole-genome duplication. The 'freshwater paralog' (α1a) is primarily expressed in the gills of Salmoniformes and an unduplicated freshwater sister species (Esox lucius) and experienced positive selection in the freshwater ancestor of Salmoniformes and Esociformes. Contrary to our predictions, the 'saltwater paralog' (α1b), which is more widely expressed than α1a, did not experience positive selection during the evolution of anadromy in the Coregoninae and Salmonine. To determine whether parallel mutations in Na(+) , K(+) ATPase α1 may contribute to salinity tolerance in other fishes, we studied independently evolved salinity-responsive Na(+) , K(+) ATPase α1 paralogs in Anabas testudineus and Oreochromis mossambicus. We found that a quarter of the mutations occurring between salmonid α1a and α1b in functionally important sites also evolved in parallel in at least one of these species. Together, these data argue that paralogs contributing to salinity tolerance evolved prior to the Salmoniform whole-genome duplication and that strong selection and/or functional constraints have led to parallel evolution in salinity-responsive Na(+) , K(+) ATPase α1 paralogs in fishes.

Due to difficulties in identifying important within-species biodiversity for effective species management and conservation, the use of multiple complementary sources of information is required to identify and assess the designation of conservation units based on the degree of variation among populations within a species. In this study, we combined estimates of microsatellite and transcriptomic variation to assess the population structure and potential for adaptive variation of threatened Atlantic salmon, Salmo salar, among rivers in the Bay of Fundy. In general, population structure identified by genetic differentiation was consistent with the patterns of variation in gene expression, although there was not a strong correlation between neutral genetic variation and variation in gene expression. Both data sets provided clear indication of strong regional differentiation between rivers located within the inner Bay of Fundy relative to rivers located within the outer Bay of Fundy or the Southern Upland region, and there was also support for more refined population structure. Both data sets indicated that Atlantic salmon populations from the inner and outer Bay of Fundy reflect unique genetic lineages, with some evidence of population differentiation between regions of the inner Bay of Fundy, and between individual rivers within a region. Consistency of the microarray data across 2 years helped to validate the use of this technique as a useful tool in assessment of variation among wild populations for species conservation.

Background Physicians are often called to evaluate patients overnight with varying levels of clinical deterioration. Early warning scores predict critical clinical deterioration in patients; however, it is unknown whether they are able to reliably predict which patients will need to be seen overnight and whether these patients will require further resource use. Methods A prospective case cohort study of 522 patient nights in a single tertiary care hospital in Vancouver, British Columbia, Canada, was conducted to assess the ability of Modified Early Warning Score (MEWS) and National Early Warning Score (NEWS) to predict patients who will need to be seen overnight by physicians and will require other healthcare resources. Prediction ability was assessed using area under the receiver operating characteristic curve and logistic regression models. Results The MEWS and NEWS both significantly predicted which patients needed to be seen overnight, and area under the receiver operating characteristic curves (95% confidence interval) for MEWS and NEWS were 0.72 (0.66–0.78) and 0.69 (0.63–0.76), respectively. Odds ratios (95% confidence interval) for MEWS and NEWS predicting need to be seen overnight were 1.52 (1.34–1.73) and 1.22 (1.14–1.31), respectively. Conclusions Both MEWS and NEWS have fair ability to predict patients who will need to be seen overnight. This may be useful for improving handover and resource allocation for overnight care.

BackgroundThe effect of a multi-faceted handoff strategy in a high volume internal medicine inpatient setting on process and patient outcomes has not been clearly established. We set out to determine if a multi-faceted handoff intervention consisting of education, standardized handoff procedures, including fixed time and location for face-to-face handoff would result in improved rates of handoff compared with usual practice. We also evaluated resident satisfaction, health resource utilization and clinical outcomes.MethodsThis was a cluster randomized controlled trial in a large academic tertiary care center with 18 inpatient internal medicine ward teams from January-April 2013. We randomized nine inpatient teams to an intervention where they received an education session standardizing who and how to handoff patients, with practice and feedback from facilitators. The control group of 9 teams continued usual non-standardized handoffs. The primary process outcome was the rate of patients handed over per 1000 patient nights. Other process outcomes included perceptions of inadequate handoff by overnight physicians, resource utilization overnight and hospital length of stay. Clinical outcomes included medical errors, frequency of patients requiring higher level of care overnight, and in-hospital mortality.ResultsThe intervention group demonstrated a significant increase in the rate of patients handed over to the overnight physician (62.90/1000 person-nights vs. 46.86/1000 person-nights, p = 0.002). There was no significant difference in other process outcomes except resource utilization was increased in the intervention group (26.35/1000 person-days vs. 17.57/1000 person-days, p-value = 0.01). There was no significant difference between groups in medical errors (4.8% vs. 4.1%), need for higher level of care or in hospital mortality. Limitations include a dependence of accurate record keeping by the overnight physician, the possibility of cross-contamination in the handoff process, analysis at the cluster level and an overall low number of clinical events.ConclusionsImplementation of a multi-faceted resident handoff intervention did not result in a significant improvement in patient safety although did improve number of patients handed off. Novel methods to improve handoff need to be explored.Trial registrationRegistered at ClinicalTrials.gov: NCT01796756.