Emergent Group Research Articles

Towards a trait‐based framework for marine macroalgae: Using categorical data to explore the nature of emergent functional groups

Abstract While trait‐based approaches have been effectively leveraged by plant ecologists to advance our understanding of community responses to major global challenges, such as climate change and invasive species, the study of marine macroalgae is still mired in a functional group (FG) framework developed in the 1980s. In this paper, we used predominantly categorical data for 18 macroalgal traits that were accessible in public databases and/or the literature to explore their usefulness in a trait‐based framework for marine macroalgae. Species were clustered into emergent, data‐driven groups using a Gower dissimilarity matrix, then a k‐medoid clustering approach called partitioning around the medoids. We identified 14 emergent groups (EGs) that captured a spectrum of strategies used by different macroalgal species. However, significant ‘gaps’ in trait space may identify evolutionary constraints to algal adaptive strategies. Multivariate analysis showed how the 18 traits created trait space and drove the clustering. A spectrum of strategies and the influence of multiple traits imply that algal strategies are likely governed by complex multivariate, not bivariate, trade‐offs. Finally, we found that our EGs appeared to reflect multivariate trade‐offs and diverse ecological strategies more than the traditional FG model for macroalgae. We tested the usefulness of our EGs by comparing real‐world spatial distributions of species across habitats with known strong environmental filters to their area occupied in trait space. We found significant separation in trait space and divergent occupancy patterns across global distributions, attachment substrates and elevational zones. These results support the use of categorical data accessible in the literature as a useful step towards developing trait‐based ecology for marine macroalgae. Synthesis. Our findings indicate that readily accessible categorical traits produce emergent FGs that reflect environmental filtering and therefore demonstrate the power of trait‐based approaches over the current FG framework. Furthermore, we posit that categorical traits are a valuable and potentially complementary addition to a newly developing database of continuous traits because they encompass a broader, more globally accessible set of traits.

TH2.2 Optimum Timing of Emergency Cholecystectomy for Acute Cholecystitis - A Single Sited Retrospective Cohort Study

Abstract Aim To evaluate timing of emergency cholecystectomy performed at one of the hospital in West Midlands. Methods This is a retrospective single centre study conducted from September 2019 to August 2020. The patients were divided into two groups with those operated within 1 week as emergency group (EG) and those operated after a week but within 6 weeks as delayed group(DG). The outcome is to evaluate post-operative complications, conversion to open, re-admissions, hospital stay, intra-operative blood loss, surgery duration and level of surgeons. Results Among 176 patients, only 88 patients underwent LC. Only 40.9% (36) underwent LC within 1 week of index admission and 12.5% (11) underwent LC after 1 week but within 6 weeks of admission. The remaining 46.5% (41) underwent delayed LC after 6 weeks. 10.6% (5) developed post op complications. Among which only one developed complication in EG and 8.5% (4) developed in DG. Total number of readmissions after LC in both group was 5.5% (5) and 10.2% (9) respectively. Median Length of hospital stay in days (4.03 versus 8.72 days respectively), Duration of surgery was 81(23–153) mins versus 69 (28–122) mins respectively), Intra operative blood loss (64 ml versus 166 ml respectively). Level of surgeon by consultant and Registrar in both groups were 21:6 and 15:5 respectively. None of the patients were converted to open surgery in both group. Conclusion Early LC within 1 week can be performed safely in most patients with AC to minimise the intra-operative blood loss, total hospital stay, post-op complication and readmissions rate.

Emergency vs elective ureteroscopy for a single ureteric stone

ABSTRACT Objective To compare emergency with elective ureteroscopy (URS) for the treatment of a single ureteric stone. Patients and methods The files of adult patients with a single ureteric stone were retrospectively reviewed. Patients with fever or turbid urine on passage of the guidewire beside the stone underwent ureteric stenting or nephrostomy drainage. Patients who underwent URS were included and divided into two groups: the emergency (EM) Group, those who presented with persistent renal colic and underwent emergency URS within 24 h; and the elective (EL) Group, who underwent elective URS after ≥14 days of diagnosis. Patients with ureteric stents were excluded. The technique for URS was the same in both groups. Safety was defined as absence of complications. Efficacy was defined as the stone-free rate after a single URS session. Results From March 2015 to September 2018, 179 patients (107 in the EM Group and 72 in the EL Group) were included. There were significantly more hydronephrosis and smaller stones in the EM Group (P = 0.002 and P = 0.001, respectively). Laser disintegration was needed in more patients in the EL Group (83% vs 68%, P = 0.023). Post-URS ureteric stents were inserted in more patients in the EM Group (91% vs 72%, P = 0.001). Complications were comparable for both groups (4.2% for EL and 5.6% for EM, P = 0.665). Stone-free rates were also comparable (93% in the EL Group and 96% in the EM Group, P = 0.336). Conclusions Emergency URS can be as safe and effective as elective URS for the treatment of a single ureteric stone if it is performed in patients without fever or turbid urine. Abbreviations: EL Group: elective group; EM Group: emergency group; KUB: plain abdominal radiograph of the kidneys, ureters and bladder; MET: medical expulsive therapy; NCCT: non-contrast CT; SFR: stone-free rate; SWL: shockwave lithotripsy; URS: ureteroscopy

The Role of Medical Air Rescue Services in Medical Transport of Organ Recipients in Poland: Organizational Solutions Supporting Transplantation Medicine.

The aim of this study was to analyze the use of fixed-wing air ambulance (FWAA) services in Poland during the period 2012-2013, with particular emphasis on air transport of organ recipients to transplantation centers. This was a retrospective, cross-sectional analysis of data derived from standard FWAA medical documentation. In the years 2012-2013 there were 500 emergency (52.7%) and 447 elective (47.3%) missions. Children who were 1-10 years old comprised the single largest group in both emergency (EM) and elective (EL) missions, accounting for 17% of all flights. EM transports carried mainly patients aged 49-59 (18.5%), and 35.1% of all EM transports concerned patients with end-stage renal disease qualified as organ recipients who were transported to transplantation centers. With a total of 2278 kidney transplantations performed in Poland within the period analyzed, up to 7.8% recipients were transported by air medical services. For EL flights, the most numerous group were patients aged 1-10 (25.4%) and this group comprised mainly patients with congenital disorders (17.9%) and cardiovascular diseases (15.8%). The average flight duration was similar for both EM and EL groups (41.7±10.5 min vs. 40.4±8.7 min, respectively) (p=NS), as was the average distance covered (321.8±99.4 km vs. 310.5±87.4 km, respectively) (p=NS). In the case of patients with end-stage renal disease, the average distance and flight time were significantly longer than those for all other groups in total: 382.5±96.4 km vs. 302.6±87.3 km (p<0.001) and 74.9±10.2 min vs. 39.7±8.8 min (p<0.001), respectively. The most frequent clinical indication for FWAA transport was end-stage renal disease and most of those flights were carried out as EM. The FWAA service plays a vital role in the organization of pre-transplantation transport to referral centers in Poland. This analysis supports the data for evaluation and potential changes in the Polish distribution and allocation rules for kidney transplantation.

Colonization Credit in Restored Wet Heathlands

Although human‐driven landscape modification is generally characterized by habitat destruction and fragmentation, it may also result in the creation of new habitat patches, providing conditions conducive to spontaneous colonization. In this article, we propose the concept of “colonization credit” (i.e., the number of species yet to colonize a patch, following landscape changes) as a framework to evaluate the success of colonization, in terms of species richness, in new/restored habitats, taking into account the spatial structure of landscapes. The method mirrors similar approaches used to estimate extinction debt in the context of habitat fragmentation, that is, comparisons, between old and new habitat patches, of the relationships among spatial patch metrics and patch species richness. We applied our method to the case of spontaneous colonization of newly created habitat patches suitable for wet heathland plant communities in South Belgium. Colonization credit was estimated for the total species richness, the specialist species richness, and the species richness of three emergent groups (EGs) of specialist species, delineated on the basis of dispersal traits. No significant colonization credit was identified either in patches created 25–55 years ago or in those created within the past 25 years, with the exception of species from our first EG (mostly anemochorous species with long‐term persistent seed bank). However, the differential response of species in that first EG could not be explained through their characteristic life history traits. The results of this study are encouraging and suggest that deliberate, directed restoration activities could yield positive developments in a relatively short period of time.

Analysing the spatial heterogeneity of emergent groups to assess ecological restoration

Summary 1. Effective restoration of ecosystem structure and function needs to be built on a strong conceptual basis. The evaluation of restoration is critical in this respect, as it requires an accurate understanding of vegetation dynamics. This study was, therefore, designed to analyse how initial restoration treatments and spontaneous ecological processes act together to produce spatial heterogeneity of plant species at various scales, taking into account that species might respond differentially to these processes in accordance with their biological attributes. 2. In a model system consisting of a large land settlement located on the banks of the river Rhône (France), 85 geo‐referenced plots were located, and the abundance of all plant species and seven biotic and abiotic environmental factors that have been modified by restoration were recorded. All species were classified into emergent groups (EGs) based on 12 plant traits, and the abundance of each EG was derived for each plot. Spatial variables that explained the spatial autocorrelation of the EGs at four scales were computed. This was performed using a spatial eigenvector mapping technique. The spatial variables were then linked to a range of selected environmental factors. 3. Large‐scale patterning of EGs was explained mainly by the spatial heterogeneity of soil quality and vegetation cover. The attribute combination of the EGs that varied most at this scale suggested that the restoration had influenced vegetation development by inducing harsh physical conditions in some part of the studied area and biotic filtering (through competition) in others. 4. A large amount of the spatial variation of EGs was not explained by the environmental factors providing some evidence for pure spatial autocorrelation effects. At the finest scale, this was linked to poor dispersal abilities of some EGs. 5. Synthesis and applications. By combining a trait‐based approach with spatially explicit methods, we explained and quantified the role of environmental changes induced by restoration and spontaneous biotic processes in structuring plant communities on different spatial scales within a large land settlement. We discuss how such an approach offers new opportunities for an improved assessment of induced and spontaneous structuring factors for restoring and for monitoring plant communities during ecological restoration.

Do the risks of emergent colectomy justify nonoperative management strategies for recurrent diverticulitis?

Background The nonoperative approach to recurrent and even multiple recurrent diverticulitis has recently been advocated. This approach, however, may result in more frequent acute attacks requiring emergent colectomy. Our aim was to compare the colectomy outcomes for diverticulitis in the elective and acute settings. Methods All patients with diverticulitis undergoing elective (EL) and emergent (EM) colectomy selected from the 2001 to 2002 Nationwide Inpatient Sample Database were analyzed and compared. Results Five thousand ninety-seven (27.1% emergent) colectomy cases were analyzed. EL patients had a significantly reduced length of stay (7.5 vs 13.3 days) and total hospital charges ($25,420 vs $51,170). Postsurgical morbidity and mortality were significantly higher in the EM group (29.0% vs 14.9% and 7.4% vs .8%, respectively). Colostomy was needed in 5.7% of EL and in 48.9% of EM patients ( P = .001). Conclusions Emergent colectomy in the setting of diverticulitis is associated with significantly higher morbidity, longer hospitalization, greater hospital charges, and a 9-fold increase in mortality. Prophylactic resection in the setting of recurrent diverticulitis should continue to be an acceptable and possibly more “conservative” approach.

No evidence of a plant extinction debt in highly fragmented calcareous grasslands in Belgium

Long transient times in response to decreasing habitat area and increasing isolation may cause the present plant species distribution to reflect the historical rather than the present landscape configuration, resulting in a so-called extinction debt. To investigate how plant species richness is shaped by both present and historical landscape configuration and local environmental conditions in fragmented calcareous grasslands, 64 sites in Southern Belgium were surveyed for their total species richness and environmental characteristics. Species were subdivided in specialist and generalist groups and the former were clustered into emergent groups (EGs) according to 16 relevant life-history traits. Four specialist emergent groups were derived: orchids, rosette species, annuals and half-rosette species. Both specialist and generalist species richness increased with present fragment area, while present fragment connectivity only affected the number of specialist species. This trend was maintained for most EGs, although habitat area was mostly more important than connectivity. All species groups responded to an insolation gradient, except EGs of rosette and annual species. Differential response to fragmentation among emergent groups could be interpreted in terms of dispersal and persistence traits. No relation between species richness and historical area or connectivity was found, making an extinction debt unlikely. Hence, present-day variation in plant species diversity seems to be no legacy of past landscape configuration. Our results clearly indicate that plant species may be quickly lost in response to new fragmentation events. To restore plant diversity, management should focus both on mitigating landscape fragmentation and restoring habitat quality.

The relative importance of local, regional and historical factors determining the distribution of plants in fragmented riverine forests: an emergent group approach

AbstractAim To investigate how local, regional and historical factors shape the herbaceous plant communities in fragmented riverine forests, and how the community composition and species richness of these fragments is related to the interplay between the environmental factors and specific plant life‐trait combinations.Location Riverine forest fragments in the Grand‐duché de Luxembourg.Methods Forest fragments were surveyed for their abundance in herbaceous plant species. All plant species where clustered into Emergent Groups (EG) by means of a formal classification based on 14 life‐history traits. Within each EG, the local, regional and historical factors were related to the community composition using partial Canonical Correspondence Analyses (pCCA) and to the species richness using Generalized Linear Models (GLMs). The EG colonization ability was characterized by means of logistic regressions.Results We defined and characterized seven EGs, among which three consisted of forest specialist species (barochorous perennials, short geophytes and zoochorous perennials), which exhibited specific life‐trait combinations: large and short‐lived seeds and/or vernal phenology. Differences in EG composition between forest fragments were mainly explained by local environmental factors such as soil productivity and pH. The richness of barochorous perennials and short geophytes was well predicted by the historical and regional factors. The colonization ability appeared very low for barochorous perennials and short geophytes.Main conclusions Local environmental conditions appear to drive the differentiation of the riverine forest plant communities owing to the specific habitat requirements of many forest species. Spatial and temporal forest discontinuities affect the richness of forest specialist species, due to dispersal and/or recruitment limitations. The emergent group approach enhances the understanding of the relative influence of local, regional and historical factors by distinguishing between forest specialists from generalists or ‘matrix’ species, which have a masking effect.

Evaluation of the ecological restoration potential of plant communities in Norway spruce plantations using a life‐trait based approach

Summary In Europe, intensively managed coniferous plantations rarely achieve similar nature conservation functions as deciduous woodlands. The ability to identify coniferous plantations that might be successfully converted to deciduous woodland is a key goal in forest management. The herbaceous plant community composition of mature plantations may be an accurate selection criterion for stands that are most suitable for initiating the conversion process to deciduous forest. The herbaceous plant communities in Norway spruce plantations were analysed using a functional group approach. The analysis was conducted in three steps: (i) identification of emergent groups (EG) by multivariate classification; (ii) comparison of EG abundance between coniferous and deciduous stands (i.e. the target communities); (iii) partitioning the variation in EG abundance in coniferous plantations between forest management, local environmental and regional variables. Seven EG were identified: two core forest groups (short geophytes and zoochoreous perennials), two groups from open habitats (annuals and helophytes) and three mixed groups (anemochoreous perennials, graminoids and short perennials). Among the core forest groups, short geophytes were severely under‐represented in plantations (because of their low dispersal abilities and specific habitat requirements) while zoochoreous perennials were slightly more abundant (because of their good dispersal and competitive abilities). Regional variables largely influenced the abundance of core‐forest EG. Restoration of communities rich in zoochoreous perennials is far easier than restoring short geophyte‐rich communities because of the different colonization abilities of these EG. Forest management variables were of secondary importance for the restoration potential of plantations. Because generalist EG were favoured by low stand densities, forest practitioners should avoid large thinning operations. Local environmental variables played a minor role in determining EG abundance. However, short geophytes preferred rather high soil pH values and were therefore negatively affected by acidification caused by coniferous litter. Synthesis and applications. The performance of short geophytes is the key to conversion success of Norway spruce plantations to deciduous forest. Stands located on base‐rich soils and in landscapes with high forest connectivity are the most appropriate candidates for initiating the conversion process. For other types of stands, future work should explore the possibility of restoring other land‐use types, such as annually mown meadows.

Child-Turcotte-Pugh versus MELD score as a predictor of outcome after elective and emergent surgery in cirrhotic patients

Background Cirrhotic patients who present for elective and emergent surgery pose a formidable challenge for the surgeon because of the high reported morbidity and mortality. The Child-Turcotte-Pugh (CTP) score previously has been used to evaluate preoperative severity of liver dysfunction and to predict postoperative outcome. Recently, a more objective scoring classification, the model for end-stage liver disease (MELD), has been shown to predict accurately the 3-month mortality for cirrhotic patients awaiting transplantation. We sought to compare the CTP and MELD scores in predicting outcomes in cirrhotic patients undergoing surgical procedures requiring general anesthesia. Methods During the study period, 40 patients with a history of cirrhosis who required elective (E) or emergent (EM) surgical procedures under general anesthesia were reviewed (E = 24, EM = 16). The preoperative CTP and MELD scores were calculated and patient short- (30-day) and long-term (3-month) outcomes were recorded. Results There was a significant difference in the 1-month and 3-month mortality rates between the emergent and elective groups (EM group: 1 mo = 19%, 3 mo = 44%; E group: 1 mo = 17%, 3 mo = 21%, P <0.05). There was good correlation between the CP and MELD scores, which was greater in the emergent groups as compared with the elective group (EM: r = 0.81; E: r = 0.65). Conclusions Our study shows that cirrhotic patients who undergo surgery under general anesthesia have an extremely high 1- and 3-month mortality rate that progressively increases with severity of preoperative liver dysfunction. Additionally, the MELD score correlates well with the CTP score, providing a more objective predictor of postoperative mortality in cirrhotic patients undergoing surgery.