Marine heatwave duration and intensity interact to reduce physiological tipping points of kelp species with contrasting thermal affinities.

BACKGROUND AND AIMS: Marine heatwaves (MHWs) are widely recognized as pervasive drivers of ecosystem change, yet our understanding of how different MHW properties mediate ecological responses remains largely unexplored. Understanding MHW impacts on foundation species is particularly important, given their structural role in communities and ecosystems. METHODS: We simulated a series of realistic MHWs with different levels of intensity (Control: 14 °C, Moderate: 18 °C, Extreme: 22 °C) and duration (14 or 28 d) and examined responses of two habitat-forming kelp species in the southwest UK. Here, Laminaria digitata reaches its trailing edge and is undergoing a range contraction, whereas Laminaria ochroleuca reaches its leading edge and is undergoing a range expansion. KEY RESULTS: For both species, sub-lethal stress responses induced by moderate-intensity MHWs were exacerbated by longer duration. Extreme-intensity MHWs caused dramatic declines in growth and photosynthetic performance, and elevated bleaching, which were again exacerbated by longer MHW duration. Stress responses were most pronounced in L. ochroleuca, where almost complete tissue necrosis was observed by the end of the long-duration MHW. This was unexpected given the greater thermal safety margins assumed with leading edge populations. It is likely that prolonged exposure to sub-lethal thermal stress exceeded a physiological tipping point for L. ochroleuca, presumably due to depletion of internal reserves. CONCLUSIONS: Overall, our study showed that exposure to MHW profiles projected to occur in the region in the coming decades can have significant deleterious effects on foundation kelp species, regardless of their thermal affinities and location within respective latitudinal ranges, which would probably have consequences for entire communities and ecosystems.

Establishing spirituality as an intermediary determinant of health among 42,843 children from eight countries.

The World Health Organization (WHO) Commission on the Social Determinants of Health (CSDH) conceptual framework identifies socio-economic position as a structural determinant of health. Recognized intermediary determinants include biological, behavioural, and psychosocial factors. We examined whether connections afforded by a healthy spirituality potentially act as unrecognized intermediary determinants in adolescent populations, contributing to inequities in mental health. Reports from 42,843 children (21,007 boys, 21,836 girls) from eight countries who participated in the 2017-2018 Health Behaviour in School-aged Children (HBSC) study were used to describe correlations between family affluence and positive levels of mental health, using a cross-sectional design. Based on the CSDH conceptual framework and multivariable regression analyses, we then examined whether these associations were mediated by spiritual health. Connections afforded by a high level of spiritual health were universally correlated with positive mental health status. In three Western European nations (England, Scotland, and Wales) and Canada affluence was correlated with better mental health and this was partially mediated by spiritual health. Among the four Eastern European countries (Latvia, Lithuania, Moldova, Poland), our findings did not support aspects of the CSDH framework that focus on affluence as a direct determinant of health. Spiritual health potentially is an intermediary determinant of children's health in some Western countries, but not in Eastern countries. The universality of social determinants of health models and the measures used in their evaluation require careful assessment across cultures, political contexts, and health outcomes.

Seasonal development of a tidal mixing front drives shifts in community structure and diversity of bacterioplankton.

Bacterioplankton underpin biogeochemical cycles and an improved understanding of the patterns and drivers of variability in their distribution is needed to determine their wider functioning and importance. Sharp environmental gradients and dispersal barriers associated with ocean fronts are emerging as key determinants of bacterioplankton biodiversity patterns. We examined how the development of the Celtic Sea Front (CF), a tidal mixing front on the Northwest European Shelf affects bacterioplankton communities. We performed 16S-rRNA metabarcoding on 60 seawater samples collected from three depths (surface, 20 m and seafloor), across two research cruises (May and September 2018), encompassing the intra-annual range of the CF intensity. Communities above the thermocline of stratified frontal waters were clearly differentiated and less diverse than those below the thermocline and communities in the well-mixed waters of the Irish Sea. This effect was much more pronounced in September, when the CF was at its peak intensity. The stratified zone likely represents a stressful environment for bacterioplankton due to a combination of high temperatures and low nutrients, which fewer taxa can tolerate. Much of the observed variation was driven by Synechococcus spp. (cyanobacteria), which were more abundant within the stratified zone and are known to thrive in warm oligotrophic waters. Synechococcus spp. are key contributors to global primary productivity and carbon cycling and, as such, variability driven by the CF is likely to influence regional biogeochemical processes. However, further studies are required to explicitly link shifts in community structure to function and quantify their wider importance to pelagic ecosystems.

Consistency and Variation in the Kelp Microbiota: Patterns of Bacterial Community Structure Across Spatial Scales.

Kelp species are distributed along ~ 25% of the world's coastlines and the forests they form represent some of the world's most productive and diverse ecosystems. Like other marine habitat-formers, the associated microbial community is fundamental for host and, in turn, wider ecosystem functioning. Given there are thousands of bacteria-host associations, determining which relationships are important remains a major challenge. We characterised the associated bacteria of two habitat-forming kelp species, Laminaria hyperborea and Saccharina latissima, from eight sites across a range of spatial scales (10 s of metres to 100 s of km) in the northeast Atlantic. We found no difference in diversity or community structure between the two kelps, but there was evidence of regional structuring (across 100 s km) and considerable variation between individuals (10 s of metres). Within sites, individuals shared few amplicon sequence variants (ASVs) and supported a very small proportion of diversity found across the wider study area. However, consistent characteristics between individuals were observed with individual host communities containing a small conserved "core" (8-11 ASVs comprising 25 and 32% of sample abundances for L. hyperborea and S. latissima, respectively). At a coarser taxonomic resolution, communities were dominated by four classes (Planctomycetes, Gammaproteobacteria, Alphaproteobacteria and Bacteroidia) that made up ~ 84% of sample abundances. Remaining taxa (47 classes) made up very little contribution to overall abundance but the majority of taxonomic diversity. Overall, our study demonstrates the consistent features of kelp bacterial communities across large spatial scales and environmental gradients and provides an ecologically meaningful baseline to track environmental change.

Core Community Persistence Despite Dynamic Spatiotemporal Responses in the Associated Bacterial Communities of Farmed Pacific Oysters.

A breakdown in host-bacteria relationships has been associated with the progression of a number of marine diseases and subsequent mortality events. For the Pacific oyster, Crassostrea gigas, summer mortality syndrome (SMS) is one of the biggest constraints to the growth of the sector and is set to expand into temperate systems as ocean temperatures rise. Currently, a lack of understanding of natural spatiotemporal dynamics of the host-bacteria relationship limits our ability to develop microbially based monitoring approaches. Here, we characterised the associated bacterial community of C. gigas, at two Irish oyster farms, unaffected by SMS, over the course of a year. We found C. gigas harboured spatiotemporally variable bacterial communities that were distinct from bacterioplankton in surrounding seawater. Whilst the majority of bacteria-oyster associations were transient and highly variable, we observed clear patterns of stability in the form of a small core consisting of six persistent amplicon sequence variants (ASVs). This core made up a disproportionately large contribution to sample abundance (34 ± 0.14%), despite representing only 0.034% of species richness across the study, and has been associated with healthy oysters in other systems. Overall, our study demonstrates the consistent features of oyster bacterial communities across spatial and temporal scales and provides an ecologically meaningful baseline to track environmental change.

Multiscale Spatial Variability and Stability in the Structure and Diversity of Bacterial Communities Associated with the Kelp Eisenia cokeri in Peru.

Ecological communities are structured by a range of processes that operate over a range of spatial scales. While our understanding of such biodiversity patterns in macro-communities is well studied, our understanding at the microbial level is still lacking. Bacteria can be free living or associated with host eukaryotes, forming part of a wider "microbiome," which is fundamental for host performance and health. For habitat forming foundation-species, host-bacteria relationships likely play disproportionate roles in mediating processes for the wider ecosystem. Here, we describe host-bacteria communities across multiple spatial scales (i.e., from 10s of m to 100s of km) in the understudied kelp, Eisenia cokeri, in Peru. We found that E. cokeri supports a distinct bacterial community compared to the surrounding seawater, but the structure of these communities varied markedly at the regional (~480 km), site (1-10 km), and individual (10s of m) scale. The marked regional-scale differences we observed may be driven by a range of processes, including temperature, upwelling intensity, or regional connectivity patterns. However, despite this variability, we observed consistency in the form of a persistent core community at the genus level. Here, the genera Arenicella, Blastopirellula, Granulosicoccus, and Litorimonas were found in >80% of samples and comprised ~53% of total sample abundance. These genera have been documented within bacterial communities associated with kelps and other seaweed species from around the world and may be important for host function and wider ecosystem health in general.

The Impact of the COVID-19 Pandemic on the Mental Health of First-Year Undergraduate Students Studying at a Major Canadian University: A Successive Cohort Study.

OBJECTIVE: To examine the impact of the COVID-19 pandemic on first year undergraduate student mental health. METHODS: As part of the Queen's University U-Flourish Student Well-Being and Academic Success study, three successive cohorts of students entering undergraduate studies in 2018 (pre-pandemic), 2019 (transitional), and 2020 (during pandemic) completed electronic surveys at entry and completion of first year. Validated self-report measures were used to assess mental health status including symptom levels of anxiety, depression, and insomnia, self-harm and frequency of substance use. Propensity matching and multivariable log-binomial regression were used in comparisons of mental health indicators across the cohorts. RESULTS: Clinically significant symptoms of depression, anxiety, insomnia, and self-harm were reported more frequently in the 2020-2021 cohort, coincident with remote learning and pandemic restrictions. In female students, screen positive rates for anxiety and depression, and suicidal ideation increased from about one-third to just under one-half in association with the pandemic (χ2, p < .01), while increases in mental health concerns were less pronounced among males. Among females, increases in clinically significant symptoms over first year appeared greatest during the pandemic year, while striking decreases in alcohol consumption in both females and males were reported in that same year. Studying under pandemic conditions had a negative impact on student well-being, social relationships and school connectedness, quality of learning experience, leisure activities, and optimism about future prospects. CONCLUSIONS: Mental health concerns including anxiety, depression and sleep problems increased in first year students during the pandemic, especially among females, while alcohol use declined. These findings highlight the negative mental health impact associated with studying under pandemic restrictions involving remote learning and social distancing.

Childhood Adversity and Mental Health Outcomes Among University Students: A Longitudinal Study.

BACKGROUND: Mental health concerns are common among university students and maybe elevated among those with specific risk exposures. The study examined the association between childhood adversities and mental health outcomes among undergraduate university students and assessed whether psychosocial and behavioral factors mediate those associations. METHODS: The Queen's University Student Well-Being and Academic Success Survey identified two large cohorts of first-year undergraduate students entering university in Fall 2018 and 2019 (n = 5,943). At baseline, students reported sociodemographic information, family-related mental health history, childhood physical abuse, sexual abuse, peer bullying, and parental separation or divorce. Baseline and follow-up surveys in Spring 2019, Fall 2019, and Spring 2020 included validated measures of anxiety (7-item Generalized Anxiety Disorder) and depressive symptoms (9-item Patient Health Questionnaire ), non-suicidal self-harm, and suicidality, along with psychological processes and lifestyle variables. Repeated measures logistic regression using Generalized Estimating Equations was used to characterize the associations between childhood adversities and mental health outcomes and examine potential mediation. RESULTS: Adjusting for age, gender, ethnicity, familial mental illness, and parental education, any childhood abuse (odds ratio: 2.89; 95% confidence interval, 2.58 to 3.23) and parental separation or divorce (odds ratio: 1.29; 95% confidence interval, 1.12 to 1.50) were significantly associated with a composite indicator of mental health outcomes (either 9-item Patient Health Questionnaire score ≥10 or 7-item Generalized Anxiety Disorderscore ≥10 or suicidality or self-harm). The association with childhood abuse weakened when adjusted for perceived stress, self-esteem, and insomnia (odds ratio: 2.05; 95% confidence interval, 1.80 to 2.34), and that with parental divorce weakened when adjusted for self-esteem (odds ratio: 1.17; 95% confidence interval, 1.00 to 1.36). CONCLUSION: Childhood abuse and parental separation or divorce were associated with mental health concerns among university students. Childhood adversities may impact later mental health through an association with stress sensitivity, self-esteem, and sleep problems. The findings suggest that prevention and early intervention focusing on improving sleep, self-esteem, and coping with stress while considering the individual risk profile of help-seeking students may help support student mental health.

Access to medical care and its association with physical injury in adolescents: a cross-national analysis.

BACKGROUND: Strong variations in injury rates have been documented cross-nationally. Historically, these have been attributed to contextual determinants, both social and physical. We explored an alternative, yet understudied, explanation for variations in adolescent injury reporting-that varying access to medical care is, in part, responsible for cross-national differences. METHODS: Age-specific and gender-specific rates of medically treated injury (any, serious, by type) were estimated by country using the 2013/2014 Health Behaviour in School-aged Children study (n=209 223). Available indicators of access to medical care included: (1) the Healthcare Access and Quality Index (HAQ; 39 countries); (2) the Universal Health Service Coverage Index (UHC; 37 countries) and (3) hospitals per 100 000 (30 countries) then physicians per 100 000 (36 countries). Ecological analyses were used to relate injury rates and indicators of access to medical care, and the proportion of between-country variation in reported injuries attributable to each indicator. RESULTS: Adolescent injury risks were substantial and varied by country and sociodemographically. There was little correlation observed between national level injury rates and the HAQ and UHC indices, but modest associations between serious injury and physicians and hospitals per 100 000. Individual indicators explained up to 9.1% of the total intercountry variation in medically treated injuries and 24.6% of the variation in serious injuries. CONCLUSIONS: Cross-national variations in reported adolescent serious injury may, in part, be attributable to national differences in access to healthcare services. Interpretation of cross-national patterns of injury and their potential aetiology should therefore consider access to medical care as a plausible explanation.

Connections associated with a healthy spirituality: are these unrecognized intermediary determinants that shape health inequities in Canadian young people?

BACKGROUND: The health of adolescents is determined by structural and intermediary factors. Such factors operate through pathways that foster different opportunities to achieve health and wellbeing, contributing to inequities. Past analyses of cross-national adolescent health data show that measures of child spirituality, conceptualized as the strength of the connections in our lives, may operate as intermediary determinants in some Western countries. Inspired by this idea, the current analysis provides an in-depth exploration of such pathways among Canadian adolescents. Our objectives were to confirm the existence of relationships between economic position and seven indicators of adolescent health status, then explore whether any observed inequities could be explained by the strength of connections afforded by a healthy spirituality. METHODS: Cycle 8 of the Canadian Health Behaviour in School-aged Children (HBSC) study was conducted in 2017-18. A school-based sample (n = 18,962) of adolescents was obtained from across Canada following a standard cross-national protocol. Eligible participants completed a general survey about their health, health behaviours and their determinants. Survey data were used to model the potential effect of perceived levels of relative affluence on each of seven health indicators. Comparison of crude and adjusted relative risks estimates from weighted log-binomial regression models provided evidence of indirect mediating effects attributable to each of four domains of spirituality. RESULTS: As perceived levels of family affluence increased, the percentages of young people who reported each (7/7) of the negative health outcomes decreased. The spiritual health domain "connections to self" (i.e., the importance of meaning, purpose, joy and happiness in life) mediated the strength of relationships between relative affluence and each (7/7) of the outcomes in boys and girls. "Connections to others" (the importance of kindness, respect and forgiveness) mediated the strength of relationships between relative affluence and each (7/7) of the outcomes among girls. Inconsistent evidence of possible mediation was identified for connections to others in boys, as well as the other two domains of spirituality (connections to nature, then connections to the transcendent) in boys and girls. CONCLUSION: Specific connections afforded by a healthy spirituality could be intermediary determinants of health in Canadian adolescent populations.

SILAC Phosphoproteomics Reveals Unique Signaling Circuits in CAR-T Cells and the Inhibition of B Cell-Activating Phosphorylation in Target Cells.

Chimeric antigen receptor (CAR) is a single-pass transmembrane receptor designed to specifically target and eliminate cancers. While CARs prove highly efficacious against B cell malignancies, the intracellular signaling events which promote CAR T cell activity remain elusive. To gain further insight into both CAR T cell signaling and the potential signaling response of cells targeted by CAR, we analyzed phosphopeptides captured by two separate phosphoenrichment strategies from third generation CD19-CAR T cells cocultured with SILAC labeled Raji B cells by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Here, we report that CD19-CAR T cells upregulated several key phosphorylation events also observed in canonical T cell receptor (TCR) signaling, while Raji B cells exhibited a significant decrease in B cell receptor-signaling related phosphorylation events in response to coculture. Our data suggest that CD19-CAR stimulation activates a mixture of unique CD19-CAR-specific signaling pathways and canonical TCR signaling, while global phosphorylation in Raji B cells is reduced after association with the CD19-CAR T cells.

Opioid Use After Laparoscopic Surgery for Endometriosis and Pelvic Pain.

STUDY OBJECTIVE: The primary objective was to quantify postoperative opioid use after laparoscopic surgery for endometriosis or pelvic pain. The secondary objective was to identify patient characteristics associated with greater postoperative opioid requirements. DESIGN: Prospective, survey-based study in which subjects completed 1 preoperative and 7 postoperative surveys within 28 days of surgery regarding medication usage and pain control. SETTING: Tertiary care, academic center. PATIENTS: A total of 100 women with endometriosis or pelvic pain. INTERVENTIONS: Laparoscopic same-day discharge surgery by fellowship-trained minimally invasive gynecologists. MEASUREMENTS AND MAIN RESULTS: A total of 100 patients were recruited and 8 excluded, for a final sample size of 92 patients. All patients completed the preoperative survey. Postoperative response rates ranged from 70.7% to 80%. The mean number of pills (5 mg oxycodone tablets) taken by day 28 was 6.8. The average number of pills prescribed was 10.2, with a minimum of 4 (n = 1) and maximum of 20 (n = 3). Previous laparoscopy for pelvic pain was associated with a significant increase in postoperative narcotic use (8.2 vs 5.6; p = .044). Hysterectomy was the only surgical procedure associated with a significant increase in postoperative narcotic use (9.7 vs 5.4; p = .013). There were no difference in number of pills taken by presence of deep endometriosis or pathology-confirmed endometriosis (all p >.36). There was a trend of greater opioid use in patients with diagnoses of self-reported chronic pelvic pain, anxiety, and depression (7.9 vs 5.7, p = .051; 7.7 vs 5.2, p = .155; 8.1 vs 5.6, p = .118). CONCLUSION: Most patients undergoing laparoscopic surgery for endometriosis and pelvic pain had a lower postoperative opioid requirement than prescribed, suggesting surgeons can prescribe fewer postoperative narcotics in this population. Patients with a previous surgery for pelvic pain, self-reported chronic pelvic pain syndrome, anxiety, and depression may represent a subset of patients with increased postoperative opioid requirements.

Discovery of the parasite Marteilia cocosarum sp. nov. In common cockle (Cerastoderma edule) fisheries in Wales, UK and its comparison with Marteilia cochillia.

Diseases of bivalve molluscs caused by paramyxid parasites of the genus Marteilia have been linked to mass mortalities and the collapse of commercially important shellfish populations. Until recently, no Marteilia spp. have been detected in common cockle (Cerastoderma edule) populations in the British Isles. Molecular screening of cockles from ten sites on the Welsh coast indicates that a Marteilia parasite is widespread in Welsh C. edule populations, including major fisheries. Phylogenetic analysis of ribosomal DNA (rDNA) gene sequences from this parasite indicates that it is a closely related but different species to Marteilia cochillia, a parasite linked to mass mortality of C. edule fisheries in Spain, and that both are related to Marteilia octospora, for which we provide new rDNA sequence data. Preliminary light and transmission electron microscope (TEM) observations support this conclusion, indicating that the parasite from Wales is located primarily within areas of inflammation in the gills and the connective tissue of the digestive gland, whereas M. cochillia is found mainly within the epithelium of the digestive gland. The impact of infection by the new species, here described as Marteilia cocosarum n. sp., upon Welsh fisheries is currently unknown.

Adolescent social media use and its association with relationships and connections: Canadian Health Behaviour in School-aged Children, 2017/2018.

Background: The development of healthy relationships and connections is of fundamental importance to adolescent well-being. The use of social media plays a vital role in the lives of young Canadians, yet the association between different types of social media use and the quality of relationships and connections remains unknown, and most existing analyses on this topic are based on modest and non-representative samples. Data and methods: Using 2017/2018 reports from the nationally representative Health Behaviour in School-aged Children study (n=17,149; ages 11 to 15 years), the strength, consistency and significance of associations was examined between intensive (frequent use to connect with other people) and problematic (use that depicts addictive qualities) social media use and available measures of adolescent relationships and connections. Results: Overall, intensive use (online communication with others almost all of the time) and problematic use (potential addiction to social media) were more common in girls than boys (38% of girls versus 30% of boys and 7.7% of girls versus 5.2% of boys, respectively), with prevalence levels that rose with age. Intensive use was associated with more positive social relationships with friends, especially among girls (relative risk [RR] = 1.40 [95% confidence interval (CI) 1.28 - 1.54]), while problematic use was consistently and negatively associated with strong relationships and connections in all groups in the study. Notably, problematic use was negatively associated with strong family relationships in boys (RR = 0.58 [95% CI 0.42 to 0.79]) and girls (RR=0.48 [95% CI 0.36 to 0.63]). Interpretation: Intensive use of social media has the potential to strengthen relationships and connections in adolescents. However, when social media use becomes addictive or "problematic", it is highly correlated with weaker relationships and a sense of social disconnection. Public health initiatives related to social media use should consider how different types of social media use have the potential to impact on different aspects of health.

Distinguishing between spiritual health and religious involvement as determinants of adolescent health in Canada and the Czech Republic.

Spiritual health is a topic of emergent interest; however, lack of a clear distinction between spiritual health and religious involvement makes it difficult to understand the potential role of spiritual health as a determinant of health. Analyses of such relationships that cross countries and cultures are rare. We therefore assessed whether differences exist between spiritual health and religious involvement and their respective associations with general indicators adolescent health. The study was based on the 2013/2014 Health Behaviour in School-aged Children study conducted in Canada (n = 10 761) and the Czech Republic (n = 4411). In both countries, we failed to identify strong or statistically significant associations between self-reported religiosity and adolescent health. In contrast, adolescents with higher spiritual health scores consistently reported enhanced levels of general health status. Study findings point to the importance of a strong sense of spiritual health as a protective determinant of adolescent health, and raise questions about religious involvement as protective to adolescent health outcomes.

Estimation of unregistered patients who left without being seen: At an urban mid-sized Canadian community emergency department.

OBJECTIVE: To determine whether changes to the appearance of an emergency department (ED) waiting room influenced the number of patients who left without being seen (LWBS). DESIGN: Retrospective analysis using National Ambulatory Care Reporting System data collected at the time of patient registration. SETTING: The ED of Belleville General Hospital, a mid-sized secondary care community hospital in Ontario with a catchment population of 125 000. PARTICIPANTS: All unscheduled patients registering at the hospital to be seen in the ED from July 1 to December 31, 2016 (control period), and from July 1 to December 31, 2017 (study period). MAIN OUTCOME MEASURES: The volume of patients registering by Canadian Triage and Acuity Scale (CTAS) level to be seen in the ED during the study period compared with the volume of patients registering during the control period, and the number of LWBS during the 2 time periods. RESULTS: The average number of patients registered per month was significantly greater in the study period than in the control period (t 10 = -5.53, P < .01). A total increase of 1881 registrations was recorded in the study period, or 10.47% (increase per month ranged from 9.59% to 11.66%). The proportion of patients with less acute triage scores decreased in the study period; however, the differences in CTAS levels between the 2 years was not statistically significant (χ 2 = 1.05, P = .90). The number of LWBS according to CTAS level was lower in all categories in the study period, including those in the less acute levels, decreasing from 60 in CTAS 5 in 2016 to 45 in 2017, and 585 in CTAS 4 in 2016 to 330 in 2017. Overall, the distribution of LWBS by CTAS level was significantly different between the control and study periods (P < .01). CONCLUSION: The number of patients registering is influenced by the apparent high or low occupancy of the waiting area at the time of registration.

Effect of a physician assistant on quality and efficiency metrics in an emergency department: Population cohort study.

OBJECTIVE: To determine the effect of a physician assistant (PA) working in a secondary care hospital emergency department (ED) on the overall performance of the ED. DESIGN: A retrospective review of ED data from April 1, 2017, to September 30, 2017. SETTING: Belleville General Hospital, a secondary care hospital, ED in Ontario. PARTICIPANTS: A physician assistant, 13 emergency physicians, and 7 family physicians. MAIN OUTCOME MEASURES: Overall ED performance was evaluated using metrics from the Ontario Ministry of Health and Long-Term Care: rate of patients who left without being seen, provider initial assessment time at the 90th percentile, and the average provider initial assessment time for all patients over a 6-month period. RESULTS: In the PA group, there was a lower average daily left without being seen rate (3.4% vs 5.2%; P < .001), a lower provider initial assessment time at the 90th percentile (3.9 hours vs 4.5 hours; P < .001), a lower average provider initial assessment time (114.83 minutes vs 139.46 minutes; P < .001), and a lower average length of stay (313.85 minutes vs 348.91 minutes; P < .001). CONCLUSION: This study suggests that a PA has a statistically significant positive effect on the overall performance of an ED. Future studies should examine the effect of a PA on quality of care and hospital funding.

Summer and Winter Marine Heatwaves Favor an Invasive Over Native Seaweeds.

Marine heatwaves (MHWs) are emerging as forceful agents of ecosystem change and are increasing in frequency, duration, and intensity with climate change. During MHWs, physiological thresholds of native species may be exceeded while the performance of invasive species with warm affinities may be enhanced. As a consequence, MHWs could significantly alter an ecosystem's invasive dynamics, but such interactions are poorly understood. Following a 10-d acclimation period, we investigated the physiological resistance and resilience of an intertidal rock pool assemblage invaded by the seaweed Sargassum muticum to realistic 14-d marine heatwave scenarios (+1.5°C, +2.0°C, +3.5°C) followed by a 14-d recovery period. We conducted mesocosm experiments in both summer and winter to investigate temporal variability of MHWs. MHW treatments had clear negative impacts on native seaweeds (Fucus serratus and Chondrus crispus) while enhancing the performance of S. muticum. This pattern was consistent across season indicating that acclimation to cooler ambient temperatures results in winter MHWs having significant impacts on native species. As climate warming advances, this may ultimately lead to changes in competitive interactions and potentially exclusion of native species, while invasive species may proliferate and become more conspicuous within temperate rocky shore environments.

Intra-Annual Variability in Responses of a Canopy Forming Kelp to Cumulative Low Tide Heat Stress: Implications for Populations at the Trailing Range Edge.

Anthropogenic climate change is driving the redistribution of species at a global scale. For marine species, populations at trailing edges often live very close to their upper thermal limits and, as such, poleward range contractions are one of the most pervasive effects of ongoing and predicted warming. However, the mechanics of processes driving such contractions are poorly understood. Here, we examined the response of the habitat forming kelp, Laminaria digitata, to realistic terrestrial heatwave simulations akin to those experienced by intertidal populations persisting at the trailing range edge in the northeast Atlantic (SW England). We conducted experiments in both spring and autumn to determine temporal variability in the effects of heatwaves. In spring, heatwave scenarios caused minimal stress to L. digitata but in autumn all scenarios tested resulted in tissue being nonviable by the end of each assay. The effects of heatwave scenarios were only apparent after consecutive exposures, indicating erosion of resilience over time. Monthly field surveys corroborated experimental evidence as the prevalence of bleaching (an indication of physiological stress and tissue damage) in natural populations was greatest in autumn and early winter. Overall, our data showed that L. digitata populations in SW England persist close to their upper physiological limits for emersion stress in autumn. As the intensity of extreme warming events is likely to increase with anthropogenic climate change, thermal conditions experienced during periods of emersion will soon exceed physiological thresholds and will likely induce widespread mortality and consequent changes at the population level.

Genetic analysis provides insights into species distribution and population structure in East Atlantic horse mackerel (Trachurus trachurus and T. capensis).

Two sister species of horse mackerel (Trachurus trachurus and T. capensis) are described that are intensively harvested in East Atlantic waters. To address long-standing uncertainties as to their respective geographical ranges, overlap and intraspecific population structure this study combined genetic (mitochondrial DNA and microsatellite) analysis and targeted sampling of the hitherto understudied West African coast. mtDNA revealed two reciprocally monophyletic clades corresponding to each species with interspecies nuclear differentiation supported by FST values. The T. trachurus clade was found across the north-east Atlantic down to Ghana but was absent from Angolan and South African samples. The T. capensis clade was found only in South Africa, Angola and a single Ghanaian individual. This pattern suggests that both species may overlap in the waters around Ghana. The potential for cryptic hybridization and/or indiscriminate harvesting of both species in the region is discussed. For T. capensis mtDNA supports high gene flow across the Benguela upwelling system, which fits with the species' ecology. The data add to evidence of a lack of significant genetic structure throughout the range of T. trachurus though the assumption of demographic panmixia is cautioned against. For both species, resolution of stock recruitment heterogeneity relevant to fishery management, as well as potential hybridization, will require more powerful genomic analyses.