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The kelp, Ecklonia radiata, is an abundant subtidal ecosystem engineer in southern Australia. Density-dependent changes in the abiotic environment engineered by Ecklonia may feedback to affect reproduction and subsequent recruitment. Here, we examined: 1) how the reproductive capacity of Ecklonia individuals in the field (zoospores released · mm-2 reproductive tissue) varied with adult density and time, and 2) how the recruitment of microscopic gametophytes and sporophytes was influenced by zoospore density at two times. Zoospore production did not vary with adult density, with only one month out of ten sampled over a 2-y period showing a significant effect of density. However, zoospore production varied hugely over time, being generally highest in mid-autumn and lowest in mid-late summer. There were strong effects of initial zoospore density on gametophyte and sporophyte recruitment with both a minimum and an optimum zoospore density for sporophyte recruitment, but these varied in time. Almost no sporophytes developed when initial zoospore density was 335 · mm-2 in spring and >261 · mm-2 in winter and was zero at very high zoospore densities. These findings suggest that although adult Ecklonia density does not affect per-capita zoospore production, because there is a minimum zoospore density for sporophyte production, a decline in population-level output could feedback to impact recruitment.

Iron supplementation has been evaluated in several randomized controlled trials (RCTs) for its potential to increase baseline hemoglobin and decrease red blood cell transfusion during cardiac surgery. This study’s main objective was to evaluate the current evidence for iron administration in cardiac surgery patients. We searched MEDLINE, EMBASE, CENTRAL, Web of Science databases, and Google Scholar from inception to 19 November 2020 for RCTs evaluating perioperative iron administration in adult patients undergoing cardiac surgery. The RCTs were assessed using a risk of bias assessment and the quality of evidence was assessed using the grading of recommendations, assessments, development, and evaluations. We reviewed 1,767 citations, and five studies (n = 554) met the inclusion criteria. The use of iron showed no statistical difference in incidence of transfusion (risk ratio, 0.86; 95% confidence interval, 0.65 to 1.13). Trial sequential analysis suggested an optimal information size of 1,132 participants, which the accrued information size did not reach. The current literature does not support or refute the routine use of iron therapy in cardiac surgery patients. PROSPERO (CRD42020161927); registered 19 December 2019.

Background Iron administration has been evaluated in several randomized controlled trials for the potential of increasing baseline hemoglobin values and decreasing the incidence of red blood cell transfusion during cardiac surgery. We describe the protocol for a study aiming to evaluate the efficacy and safety of perioperative iron administration in patients undergoing cardiac surgery. Methods We will search MEDLINE, Embase, the Cochrane Central Register of Controlled Trials and the Web of Science, from inception to Nov. 19, 2020, for randomized controlled trials in any language evaluating the perioperative administration of iron in adult patients undergoing cardiac surgery; we will also include the first 50 results from Google Scholar. The primary outcome will be the incidence of red blood cell transfusion from the study intervention time until 8 weeks postoperatively. The secondary outcomes will be the number of red blood cell units transfused; change in ferritin level, reticulocyte count and hemoglobin concentration after iron administration; and adverse events. We will assess the risk of bias with the Cochrane Collaboration Risk of Bias Tool, and will analyze the primary and secondary outcomes using a random-effects model. Interpretation This study will summarize the current evidence about perioperative iron administration in patients undergoing cardiac surgery, help determine whether this intervention should be included in enhanced-recovery protocols, and shape future research if needed. The final manuscript will be submitted to a peer-reviewed journal. Trial registration PROSPERO no. CRD42020161927.

Kelp forests in many regions are experiencing disturbance from anthropogenic sources such as ocean warming, pollution, and overgrazing. Unlike natural disturbances such as storms, anthropogenic disturbances often manifest as press perturbations that cause persistent alterations to the environment. One consequence is that some kelp forests are becoming increasingly sparse and fragmented. We manipulated patch size of the kelp Ecklonia radiata over 24 mo to simulate persistent habitat fragmentation and assessed how this influenced the demography of macro- and microscopic juvenile kelp within the patches. At the beginning of the experiment, patch formation resulted in short-term increases in E. radiata recruitment in patches 2. However, recruitment collapsed in those same patches over the extended period, with no recruits observed after 15 mo. Experimental transplants of microscopic and macroscopic juvenile sporophytes into the patches failed to identify the life stage impacted by the reductions in patch size, indicating that the effects may be subtle and require extended periods to manifest, and/or that another life stage is responsible. Abiotic measurements within the patches indicated that kelp were less able to engineer the sub-canopy environment in smaller patches. In particular, reduced shading of the sub-canopy in smaller patches was associated with proliferation of sediments and turf algae, which potentially contributed to the collapse of recruitment. We demonstrate the consequences of short- and longer-term degradation of E. radiata habitats and conclude that habitat fragmentation can lead to severe disruptions to kelp demography.

Habitat‐forming ecosystem engineers are the foundation of many marine ecosystems where they support diverse and productive food‐webs. A reduction in their patch size or density may affect the productivity, biodiversity and stability of these ecosystems. We determined the effects of different densities and patch sizes of Ecklonia radiata (the dominant kelp in southern Australia) on the secondary productivity, species richness, diversity and community structure of understory epifaunal invertebrates and how associated environmental covariates modified by kelp affected those patterns. We assessed sub‐canopy epifauna across 28 artificial reefs with transplanted E. radiata consisting of seven different patch sizes (0.12–7.68 m2) crossed with four kelp densities (0–16 kelp m−2) over two years. Epifaunal secondary productivity associated with both natural algal and standardised rope fibre habitats decreased with patch size and was elevated when kelp was absent, however, it was also high in natural habitat when there was a high density of kelp. Epifaunal productivity was positively associated with sub‐canopy light and water flow but negatively associated with the biomass of the dominant understory alga, Ulva sp. Epifaunal diversity declined with a reduction in reef size as did richness which correlated with a loss of algal species richness. Community structure of epifauna also differed between small and large reefs, between reefs with and without kelp, between rope habitats at the centre and at the edge of reefs, and within natural habitat between reefs supporting high and low densities of kelp. Overall, these results indicate complex effects of E. radiata decline on epifaunal communities, with high secondary productivity associated with dense kelp stands, but also areas without kelp that are dominated by turf algae. While the loss of standing kelp from rocky reefs may result in declines in epifaunal biodiversity, where turf algae replaces kelp, the reefs may still support high secondary productivity.

Ecosystem engineers are important in shaping the composition of associated communities, including the abundance of species which exert additional influences on the ecosystem. Using an array of 28 artificial reefs supporting transplants of a dominant canopy-forming kelp (Ecklonia radiata) representing 7 patch sizes (0.12-7.68 m2) crossed with 4 kelp densities (0-16 ind. m-2), we determined how differences in the patch size and density of this ecosystem engineer influenced the associated understorey assemblages, including the abundance of turf algae, foliose algae and sessile invertebrates. We then determined how abiotic and biotic factors modified by E. radiata related to the abundance of these functional groups and E. radiata recruitment. Decreasing patch size and absence of kelp led to the proliferation of turfs, whilst foliose algae and invertebrates were dominant on larger reefs with kelp, where intermediate densities of kelp supported the highest abundance of foliose algae. We postulate that benthic light was the most important factor positively influencing turf cover, which in turn suppressed foliose algae. Adverse effects of light and sediment deposition best explained the cover of invertebrates. Contrary to expectation, understorey species had little effect on the density of E. radiata recruits, which instead was strongly correlated with the abundance of transplanted kelp on each reef. These results highlight the capacity of E. radiata to influence major functional groups within the sub-canopy via abiotic ecosystem engineering and through control of turfs and indicate that the negative effect of understorey algae on kelp recruitment may be context specific.

Ecosystem engineers are species that influence the abiotic and biotic environment around them and may assist the restoration of associated species, including other habitat‐forming species. We deployed an array of 28 artificial reefs with transplanted Ecklonia radiata, the dominant canopy‐forming kelp species across southern Australia, to investigate how the patch size and density of E. radiata influenced the establishment of the associated communities of plants and animals. Many of the reefs were rapidly colonized by Ostrea angasi, a critically depleted reef‐forming oyster. Over the 24‐month deployment of the reefs, thick oyster mats formed across the entire surface of many of the reefs with estimated biomass densities exceeding 5 kg of live oysters/m2; however, oyster density was dependent on E. radiata patch size and density. Increasing patch size and the presence of kelp resulted in significantly higher densities of oysters 5 months after the reefs were deployed and at the end of the experiment, where oysters were approximately three times more numerous on reefs with kelp compared to those without kelp. E. radiata appeared to facilitate the establishment of O. angasi largely through its capacity to reduce benthic light and thus suppress competition from turfing algae. These results may inform the development of novel approaches to tackle recruitment bottlenecks affecting the restoration of O. angasi reefs.

Kelp forests around the world are under increasing pressure from anthropogenic stressors. A widespread consequence is that in many places, complex and highly productive kelp habitats have been replaced by structurally simple and less productive turf algae habitats. Turf algae habitats resist re‐establishment of kelp via recruitment inhibition; however, little is known about the specific mechanisms involved. One potential factor is the chemical environment within the turf algae and into which kelp propagules settle and develop. Using laboratory trials, we illustrate that the chemical microenvironment (O2 concentration and pH) 0.0–50 mm above the substratum within four multispecies macroalgal assemblages (including a turf‐sediment assemblage and an Ecklonia radiata kelp‐dominated assemblage) are characterized by elevated O2 and pH relative to the surrounding seawater. Notably however, O2 and pH were significantly higher within turf‐sediment assemblages than in kelp‐dominated assemblages, and at levels that have previously been demonstrated to impair the photosynthetic or physiological capacity of kelp propagules. Field observations of the experimental assemblages confirmed that recruitment of kelp was significantly lower into treatments with dense turf algae than in the kelp‐dominated assemblages. We demonstrate differences between the chemical microenvironments of kelp and turf algae assemblages that correlate with differences in kelp recruitment, highlighting how degradation of kelp habitats might result in the persistence of turf algae habitats and the localized absence of kelp.

Iron supplementation has been evaluated in several randomized controlled trials (RCTs) for its potential to increase baseline hemoglobin and decrease red blood cell transfusion during cardiac surgery. This study's main objective was to evaluate the current evidence for iron administration in cardiac surgery patients.We searched MEDLINE, EMBASE, CENTRAL, Web of Science databases, and Google Scholar from inception to 19 November 2020 for RCTs evaluating perioperative iron administration in adult patients undergoing cardiac surgery. The RCTs were assessed using a risk of bias assessment and the quality of evidence was assessed using the grading of recommendations, assessments, development, and evaluations.We reviewed 1,767 citations, and five studies (n = 554) met the inclusion criteria. The use of iron showed no statistical difference in incidence of transfusion (risk ratio, 0.86; 95% confidence interval, 0.65 to 1.13). Trial sequential analysis suggested an optimal information size of 1,132 participants, which the accrued information size did not reach.The current literature does not support or refute the routine use of iron therapy in cardiac surgery patients.PROSPERO (CRD42020161927); registered 19 December 2019.RéSUMé: OBJECTIF: La supplémentation en fer a été évaluée dans plusieurs études randomisées contrôlées (ERC) pour son potentiel à augmenter l’hémoglobine de base et à diminuer la transfusion d’érythrocytes pendant la chirurgie cardiaque. L’objectif principal de cette étude était d’évaluer les données probantes actuelles soutenant l’administration de fer chez les patients de chirurgie cardiaque. MéTHODE: Nous avons effectué des recherches dans les bases de données MEDLINE, EMBASE, CENTRAL, Web of Science et Google Scholar de leur création jusqu’au 19 novembre 2020 pour en extraire les ERC évaluant l’administration périopératoire de fer chez les patients adultes bénéficiant d’une chirurgie cardiaque. Les ERC ont été évaluées à l’aide d’une évaluation du risque de biais et la qualité des données probantes a été évaluée à l’aide du système de notation GRADE. RéSULTATS: Nous avons examiné 1767 citations et cinq études (n = 554) répondaient aux critères d’inclusion. L’administration de fer n’a montré aucune différence statistique dans l’incidence des transfusions (risque relatif, 0,86; intervalle de confiance à 95 %, 0,65 à 1,13). Selon l’analyse séquentielle des études, la taille d’information optimale serait de 1132 participants, une taille que l’information accumulée n’a pas atteint. CONCLUSION: La littérature actuelle ne soutient ni ne réfute l’utilisation systématique d’une thérapie à base de fer chez les patients de chirurgie cardiaque. ENREGISTREMENT DE L’éTUDE: PROSPERO (CRD42020161927); enregistrée le 19 décembre 2019.

Ecosystem engineering kelp forms habitat and influences associated communities by altering abiotic conditions. These conditions can also affect the engineer's own demographic rates but the mechanisms underpinning these feedbacks are not well known. Here, we tested the interactive effects of three abiotic factors engineered by the Australasian kelp Ecklonia radiata (light, water flow and scour) on the early survivorship and growth of its outplanted microscopic recruits. After six weeks, recruit survivorship was high in the absence of scour and low light (2–3 times higher than when scour was present) and under low water flow-ambient light conditions. Growth of sporophytes was strongly related to light, with recruits under ambient light approximately four times larger after six weeks. Overall, reduced scour (for survivorship) and ambient light (for growth) appear crucial for maximising E. radiata recruitment suggesting a healthy forest can provide microenvironments to enhance survivorship while gaps in the canopy enhance growth.

As foundation species, kelp support productive and species rich communities; however, the effects of kelp structure on mobile species within these complex natural systems are often difficult to assess. We used artificial reefs with transplanted kelp to quantify the influence of kelp patch size and density on fish assemblages including the arrival of recruiting cryptobenthic species. Large patches with dense kelp supported the highest abundance, species richness, and diversity of fishes, with the addition of dense kelp tripling biomass and doubling richness. The abundance of recruits in artificial collectors declined with patch size and was halved on reefs with sparse kelp compared to reefs with dense kelp or no kelp. These results highlight the importance of dense kelp cover in facilitating biodiversity and indicate that kelp addition could support the recovery of degraded coastal ecosystems. Kelp also apparently drives complex interactions affecting the recruitment/behaviour of some cryptobenthic species.

BACKGROUND Postoperative atrial fibrillation (POAF) is associated with early and late morbidity and mortality of cardiac surgical patients. Prophylactic treatment of atrial fibrillation (AF) has been recommended to improve outcome in cardiac surgical patients at high risk of developing POAF. Reliable models for prediction of POAF are needed to achieve that goal. This study attempted to externally validate 3 risk models proposed for preoperative prediction of POAF in cardiac surgical patients: the POAF score, the CHA2DS2-VASc score, and the Atrial Fibrillation Risk Index. METHODS This was a prospective cohort study of 1416 adult patients who underwent nonemergent coronary artery bypass graft and/or valve surgery in a single cardiac surgical center between February 2014 and September 2015. A risk score for each of the 3 prediction models was calculated in each patient. All patients were followed for up to 2 weeks, or until hospital discharge, to observe the primary outcome of new onset AF requiring treatment. Discrimination was assessed using receiver operating characteristic curves. Calibration was assessed using the Pearson χ goodness-of-fit test and calibration plots. Utility of the score to implement AF prophylaxis based on the risk of POAF, in comparison to strategies of treating all patients, or not treating any patients, was assessed via a net benefit analysis. RESULTS Of the 1416 patients included in this study, 478 had the primary outcome (33.8%). The areas under the receiver operating characteristic curve for prediction of POAF in the population subsets for which the scores were validated were as follows: 0.651 (95% confidence interval [CI], 0.621-0.681) for the POAF score, 0.593 (95% CI, 0.557-0.629) for the CHA2DS2-VASc score (P < .001 versus POAF score, P < .222 versus Atrial Fibrillation Risk Index), and 0.563 (95% CI, 0.522-0.604) for the Atrial Fibrillation Risk Index (P < .001 versus POAF score). The calibration analysis showed that the predictive models had a poor fit between the observed and expected rates of POAF. Net benefit analysis showed that AF preventive strategies based on these scores, and targeting patients with moderate or high risk of POAF, improve decision-making in comparison to preventive strategies of treating all patients. CONCLUSIONS The 3 prediction scores evaluated in this study have limited ability to predict POAF in cardiac surgical patients. Despite this, they may be useful in preventive strategies targeting patients with moderate or high risk of PAOF in comparison with preventive strategies applied to all patients.

Objectives To determine whether the administration of ketamine during coronary artery bypass grafting (CABG) surgery leads to a reduction in the quantity of opioids required over the first 48 hours after surgery. Design Randomized, controlled, double-blind clinical trial. Setting Single university academic center. Participants Patients undergoing CABG surgery with a normal left ventricular ejection fraction. Interventions Ketamine administered intravenously as a bolus dose of 0.5 mg/kg before skin incision, followed by an infusion of 0.5 mg/kg/h until the end of surgery. Measurements and Main Results One hundred eighty-three patients were screened, and 80 patients were randomized. Baseline characteristics were similar between the 2 groups. The intervention group received 53.6 mg (95% confidence interval [CI] 47.1-60.1 mg) of morphine equivalents in the first 48 hours after surgery, whereas the placebo group received 55.7 mg (95% CI 48.4-63.1 mg) over the same time period (p = 0.66). No significant difference was noted in morphine equivalents over the first 6, 12, or 24 hours postoperatively or in maximum, minimum, or average pain scores on postoperative days 1 or 2. Conclusions The administration of ketamine during CABG surgery did not result in reduced opioid consumption or pain scores postoperatively.

Habitat forming ‘ecosystem engineers’ such as kelp species create complex habitats that support biodiverse and productive communities. Studies of the resilience and stability of ecosystem engineers have typically focussed on the role of external factors such as disturbance. However, their population dynamics are also likely to be influenced by internal processes, such that the environmental modifications caused by engineer species feedback to affect their own demography (e.g. recruitment, survivorship). In numerous regions globally, kelp forests are declining and experiencing reductions in patch size and kelp density. To explore how resilience and stability of kelp habitats is influenced by this habitat degradation, we created an array of patch reefs of various sizes and supporting adult Ecklonia radiata kelp transplanted at different densities. This enabled testing of how sub-canopy abiotic conditions change with reductions in patch size and adult kelp density, and how this influenced demographic processes of microscopic and macroscopic juvenile kelp. We found that ecosystem engineering by adult E. radiata modified the environment to reduce sub-canopy water flow, sedimentation, and irradiance. However, the capacity of adult kelp canopy to engineer abiotic change was dependent on patch size, and to a lesser extent, kelp density. Reductions in patch size and kelp density also impaired the recruitment, growth and survivorship of microscopic and macroscopic juvenile E. radiata, and even after the provisioning of established juveniles, demographic processes were impaired in the absence of sufficient adult kelp. These results are consistent with the hypothesis that ecosystem engineering by adult E. radiata facilitates development of juvenile conspecifics. Habitat degradation seems to impair the ability of E. radiata to engineer abiotic change, causing breakdown of positive intraspecific feedback and collapse of demographic functions, and overall, leading to reductions in ecosystem stability and resilience well before local extirpation.

Multibeam sonar (MBS) hydro-acoustic technology allows for inexpensive, broadscale, fine-resolution assessment of marine fish habitats. Parallel advancements in geographic information systems and new analytical techniques are providing researchers with the ability to generate informative surrogate predictors of biodiversity and species responses. The aim of this study was to determine whether fine-scale bathymetric derivatives of MBS survey data could be effectively applied as surrogates to explain spatial patterns in reef fish diversity and species−habitat relationships. In the absence of direct metrics of habitat, these derivatives might prove to be effective tools for marine spatial planning. Species−habitat relationships were examined across a marine reserve on the south-eastern coast of Tasmania at fine spatial scales using boosted regression tree analyses. The most important explanatory variables of community diversity were those describing the degree of reef aspect deviation from east and south (seemingly as a proxy for swell exposure), reef bathymetry (depth), plane and slope. Models could account for up to 30% of the spatial variability in measures of species diversity. Responses in species abundance and occurrence to habitat structure appeared to be largely species-specific at the scales investigated. Models accounted for up to 67% and 58% of the abundance and occurrence, respectively, for the southern hulafish Trachinops caudimaculatus . Our results demonstrate that multibeam derived metrics of reef habitat structure, employed in combination with modern modelling approaches, have the potential to explain and predict fine-resolution patterns in temperate reef fish community structure. This knowledge is urgently required to effectively manage marine ecosystems and conserve biodiversity and fisheries resources.

The influence of habitat type upon reef fish assemblage structures has been extensively reported, but there is still a need to quantitatively demonstrate the factors driving reef fish assemblages within and among habitats. This mensurative study examined diversity and community composition of reef fish assemblages between five habitats (shallow kelp, deep kelp, sand, algal turf, and sponge fiats) within the Cape Rodney‐Okakari Point Marine Reserve, northeastern New Zealand. Two contrasting sampling techniques, point count and timed search were used to quantify a range of species with different life history strategies and characteristics. Diversity generally decreased from kelp to sand habitats. Different habitat types displayed significantly different assemblages irrespective of the sampling technique used, as tested using two different multivariate techniques: constrained canonical analysis of principal coordinates and analysis of similarities (CAP, ANOSIM). Differences in depth between defined ...

Internal and external program reviews are useful for targeting areas of Computer Science and Information Technology (CSIT) curriculums for revision and improvement. The successful working graduates from CSIT programs are perhaps the knowledge experts in the areas of curriculum that need to be improved. This paper argues in favor of surveying practicing CSIT graduates in industry to gather pertinent information for revamping curriculum. The paper discusses the results of a survey used to revise the instruction and core curriculum of the degree programs in Network Information Security (NIS) and Computer Network Modeling and Simulation (CNMS) at St. Cloud State University. The paper also presents the elements of a generic tool for a comprehensive student learning outcome assessment.