North American tree migration paced by climate in the West, lagging in the East.

Tree fecundity and recruitment have not yet been quantified at scales needed to anticipate biogeographic shifts in response to climate change. By separating their responses, this study shows coherence across species and communities, offering the strongest support to date that migration is in progress with regional limitations on rates. The southeastern continent emerges as a fecundity hotspot, but it is situated south of population centers where high seed production could contribute to poleward population spread. By contrast, seedling success is highest in the West and North, serving to partially offset limited seed production near poleward frontiers. The evidence of fecundity and recruitment control on tree migration can inform conservation planning for the expected long-term disequilibrium between climate and forest distribution.

Is there tree senescence? The fecundity evidence.

Despite its importance for forest regeneration, food webs, and human economies, changes in tree fecundity with tree size and age remain largely unknown. The allometric increase with tree diameter assumed in ecological models would substantially overestimate seed contributions from large trees if fecundity eventually declines with size. Current estimates are dominated by overrepresentation of small trees in regression models. We combined global fecundity data, including a substantial representation of large trees. We compared size-fecundity relationships against traditional allometric scaling with diameter and two models based on crown architecture. All allometric models fail to describe the declining rate of increase in fecundity with diameter found for 80% of 597 species in our analysis. The strong evidence of declining fecundity, beyond what can be explained by crown architectural change, is consistent with physiological decline. A downward revision of projected fecundity of large trees can improve the next generation of forest dynamic models.

Exploring Barriers and Facilitators to Reducing the Environmental Impact of the Operating Room.

INTRODUCTION: The operating room (OR) is a major contributor to greenhouse gas emissions both nationally and globally. Successful implementation of quality improvement initiatives requires understanding of key stakeholders' perspectives of the issues at hand. Our aim was to explore surgical, anesthesia, and OR staff member perspectives on barriers and facilitators to reducing OR waste. MATERIALS AND METHODS: Identified stakeholders from a single academic medical center were interviewed to identify important barriers and facilitators to reducing surgical waste. Two team members with qualitative research experience used deductive logic guided by the Theoretical Domains Framework of behavior change to identify themes within transcripts. RESULTS: Nineteen participants including surgeons (n = 3, 15.8%), surgical residents (n = 5, 26.3%), an anesthesiologist (n = 1, 5.3%), anesthesia residents (n = 2, 10.5%), nurse anesthetists (n = 2, 10.5%), nurses (n = 5, 26.3%), and a surgical technologist (n = 1, 5.3%) were interviewed. Twelve of the 14 themes within the Theoretical Domains Framework were discovered in transcripts. Barriers within these themes included lack of resources to pursue environmental sustainability in the OR and the necessity of maintaining sterility for patient safety. Facilitators included emphasizing surgeon leadership within the OR to reduce unused supplies and spreading awareness of the environmental and economic impact of surgical waste. CONCLUSIONS: Interviewed stakeholders were able to identify areas where improvements around surgical waste reduction and management could be made at the institution by describing barriers and facilitators to sustainability-driven interventions. Future surgical waste reduction initiatives at this institution will be guided by these important perspectives.

Management of lymphocele following anterior lumbar interbody fusion, case report and review of literature.

While anterior lumbar interbody fusion (ALIF) is known as an established and safe procedure for treatment of degenerative disc disease, albeit rare, the development of postoperative intra-abdominal or retroperitoneal collection of lymph warrants timely diagnosis and management. This study presents the case of a 62-year-old male who underwent L4-L5 and L5-S1 ALIF and developed a persistent left-sided fluid collection, resulting in a symptomatic retroperitoneal lymphocele confirmed by computed tomography (CT). After percutaneous drainage by interventional radiology (IR), output remained high at 1 liter (L) per day, necessitating sclerotherapy with doxycycline and ethanol. In the absence of improvement, a lymphangiogram demonstrating a persistent lymph leak and glue embolization was performed. Due to refractory symptoms, retroperitoneal exploration with methylene blue dye was utilized for lymphatic mapping, and a lymphatic capillary leak in proximity to the left iliac artery was identified and successfully ligated with resolution of symptoms. With suspected fluid collections following ALIF, confirmation with CT or ultrasound (US) imaging followed by percutaneous drainage and testing of fluid is necessary. In mild cases, drainage alone or nonsurgical chemical sclerotherapy may suffice. In symptomatic refractory cases, localization of the site with lymphangiogram or US-guided injection of methylene blue dye allows for easier identification and definitive management with either transabdominal laparoscopic fenestration or retroperitoneal surgical exploration and ligation.

The evolutionary assembly of forest communities along environmental gradients: recent diversification or sorting of pre-adapted clades?

Recent studies have demonstrated that ecological processes that shape community structure and dynamics change along environmental gradients. However, much less is known about how the emergence of the gradients themselves shape the evolution of species that underlie community assembly. In this study, we address how the creation of novel environments leads to community assembly via two nonmutually exclusive processes: immigration and ecological sorting of pre-adapted clades (ISPC), and recent adaptive diversification (RAD). We study these processes in the context of the elevational gradient created by the uplift of the Central Andes. We develop a novel approach and method based on the decomposition of species turnover into within- and among-clade components, where clades correspond to lineages that originated before mountain uplift. Effects of ISPC and RAD can be inferred from how components of turnover change with elevation. We test our approach using data from over 500 Andean forest plots. We found that species turnover between communities at different elevations is dominated by the replacement of clades that originated before the uplift of the Central Andes. Our results suggest that immigration and sorting of clades pre-adapted to montane habitats is the primary mechanism shaping tree communities across elevations.

Local species diversity, ß-diversity and climate influence the regional stability of bird biomass across North America.

Biodiversity often stabilizes aggregate ecosystem properties (e.g. biomass) at small spatial scales. However, the importance of species diversity within communities and variation in species composition among communities (ß-diversity) for stability at larger scales remains unclear. Using a continental-scale analysis of 1657 North American breeding-bird communities spanning 20-years and 35 ecoregions, we show local species diversity and ß-diversity influence two components of regional stability: local stability (stability of bird biomass within sites) and spatial asynchrony (asynchronous fluctuations in biomass among sites). We found spatial asynchrony explained three times more variation in regional stability of bird biomass than did local stability. This result contrasts with studies at smaller spatial scales-typically plant metacommunities under 1 ha-that find local stability to be more important than spatial asynchrony. Moreover, spatial asynchrony of bird biomass increased with bird ß-diversity and climate heterogeneity (temperature and precipitation), while local stability increased with species diversity. Our study reveals new insights into the scale-dependent processes regulating ecosystem stability, providing evidence that both local biodiversity loss and homogenization can destabilize ecosystem processes at biogeographic scales.

Accurate forest projections require long-term wood decay experiments because plant trait effects change through time.

Whether global change will drive changing forests from net carbon (C) sinks to sources relates to how quickly deadwood decomposes. Because complete wood mineralization takes years, most experiments focus on how traits, environments and decomposer communities interact as wood decay begins. Few experiments last long enough to test whether drivers change with decay rates through time, with unknown consequences for scaling short-term results up to long-term forest ecosystem projections. Using a 7 year experiment that captured complete mineralization among 21 temperate tree species, we demonstrate that trait effects fade with advancing decay. However, wood density and vessel diameter, which may influence permeability, control how decay rates change through time. Denser wood loses mass more slowly at first but more quickly with advancing decay, which resolves ambiguity about the after-life consequences of this key plant functional trait by demonstrating that its effect on decay depends on experiment duration and sampling frequency. Only long-term data and a time-varying model yielded accurate predictions of both mass loss in a concurrent experiment and naturally recruited deadwood structure in a 32-year-old forest plot. Given the importance of forests in the carbon cycle, and the pivotal role for wood decay, accurate ecosystem projections are critical and they require experiments that go beyond enumerating potential mechanisms by identifying the temporal scale for their effects.

Direct and indirect effects of climate on richness drive the latitudinal diversity gradient in forest trees.

Climate is widely recognised as an important determinant of the latitudinal diversity gradient. However, most existing studies make no distinction between direct and indirect effects of climate, which substantially hinders our understanding of how climate constrains biodiversity globally. Using data from 35 large forest plots, we test hypothesised relationships amongst climate, topography, forest structural attributes (stem abundance, tree size variation and stand basal area) and tree species richness to better understand drivers of latitudinal tree diversity patterns. Climate influences tree richness both directly, with more species in warm, moist, aseasonal climates and indirectly, with more species at higher stem abundance. These results imply direct limitation of species diversity by climatic stress and more rapid (co-)evolution and narrower niche partitioning in warm climates. They also support the idea that increased numbers of individuals associated with high primary productivity are partitioned to support a greater number of species.

Enhanced recovery program implementation: an evidence-based review of the art and the science.

BACKGROUND: The benefits of enhanced recovery program (ERP) implementation include patient engagement, improved patient outcomes and satisfaction, better team relationships, lower per episode costs of care, lower public consumption of narcotic prescription pills, and the promise of greater access to quality surgical care. Despite these positive attributes, vast numbers of surgical patients are not treated on ERPs, and many of those considered "on pathway" are unlikely to be exposed to a majority of recommended ERP elements. METHODS: To explain the gap between ERP knowledge and action, this manuscript reviewed formal implementation strategies, proposed a novel change adoption model and focused on common barriers (and corollary solutions) that are encountered during the journey to a fully implemented and successful ERP. Given the nature of this review, IRB approval was not required/obtained. RESULTS: The information reviewed indicates that implementation of best practice is both a science and an art. What many surgeons have learned is that the "soft" skills of emotional intelligence, leadership, team dynamics, culture, buy-in, motivation, and sustainability are central to a successful ERP implementation. CONCLUSIONS: To lead teams toward achievement of pervasive and sustained adherence to best practices, surgeons need to learn new strategies, techniques, and skills.

Overdispersed Spatial Patterning of Dominant Bunchgrasses in Southeastern Pine Savannas.

Spatial patterning is a key natural history attribute of sessile organisms that frequently emerges from and dictates potential for interactions among organisms. We tested whether bunchgrasses, the dominant plant functional group in longleaf pine savanna groundcover communities, are nonrandomly patterned by characterizing the spatial dispersion of three bunchgrass species across six sites in Louisiana and Florida. We mapped bunchgrass tussocks of >5.0 cm basal diameter in three [Formula: see text] plots at each site. We modeled tussocks as two-dimensional objects to analyze their spatial relationships while preserving sizes and shapes of individual tussocks. Tussocks were overdispersed (more regularly spaced than random) for all species and sites at the local interaction scale (<0.3 m). This general pattern likely arises from a tussock-centered, distance-dependent mechanism, for example, intertussock competition. Nonrandom spatial patterns of dominant species have implications for community assembly and ecosystem function in tussock-dominated grasslands and savannas, including those characterized by extreme biodiversity.

Integrating species traits into species pools.

Despite decades of research on the species-pool concept and the recent explosion of interest in trait-based frameworks in ecology and biogeography, surprisingly little is known about how spatial and temporal changes in species-pool functional diversity (SPFD) influence biodiversity and the processes underlying community assembly. Current trait-based frameworks focus primarily on community assembly from a static regional species pool, without considering how spatial or temporal variation in SPFD alters the relative importance of deterministic and stochastic assembly processes. Likewise, species-pool concepts primarily focus on how the number of species in the species pool influences local biodiversity. However, species pools with similar richness can vary substantially in functional-trait diversity, which can strongly influence community assembly and biodiversity responses to environmental change. Here, we integrate recent advances in community ecology, trait-based ecology, and biogeography to provide a more comprehensive framework that explicitly considers how variation in SPFD, among regions and within regions through time, influences the relative importance of community assembly processes and patterns of biodiversity. First, we provide a brief overview of the primary ecological and evolutionary processes that create differences in SPFD among regions and within regions through time. We then illustrate how SPFD may influence fundamental processes of local community assembly (dispersal, ecological drift, niche selection). Higher SPFD may increase the relative importance of deterministic community assembly when greater functional diversity in the species pool increases niche selection across environmental gradients. In contrast, lower SPFD may increase the relative importance of stochastic community assembly when high functional redundancy in the species pool increases the influence of dispersal history or ecological drift. Next, we outline experimental and observational approaches for testing the influence of SPFD on assembly processes and biodiversity. Finally, we highlight applications of this framework for restoration and conservation. This species-pool functional diversity framework has the potential to advance our understanding of how local- and regional-scale processes jointly influence patterns of biodiversity across biogeographic regions, changes in biodiversity within regions over time, and restoration outcomes and conservation efforts in ecosystems altered by environmental change.

Transdiaphragmatic Migration of a Spinal Fixation Rod into the Lung.

Adolescent idiopathic scoliosis may require surgical treatment for extreme curvature of the spine or loss of pulmonary function. We present a report of a 31-year-old woman with a history of scoliosis and anterolateral spinal fusion who developed chest pain and hemoptysis. Imaging revealed that a fixation rod had migrated cephalad, penetrating the diaphragm into the left lower lobe of the lung. The hardware was removed and lung repaired with good results. This is the first reported case of cranial spinal rod migration over a decade after initial implantation.

Dispersal and neutral sampling mediate contingent effects of disturbance on plant beta-diversity: a meta-analysis.

A major challenge in ecology, conservation and global-change biology is to understand why biodiversity responds differently to similar environmental changes. Contingent biodiversity responses may depend on how disturbance and dispersal interact to alter variation in community composition (ß-diversity) and assembly mechanisms. However, quantitative syntheses of these patterns and processes across studies are lacking. Using null-models and meta-analyses of 22 factorial experiments in herbaceous plant communities across Europe and North America, we show that disturbance diversifies communities when dispersal is limited, but homogenises communities when combined with increased immigration from the species pool. In contrast to the hypothesis that disturbance and dispersal mediate the strength of niche assembly, both processes altered ß-diversity through neutral-sampling effects on numbers of individuals and species in communities. Our synthesis suggests that stochastic effects of disturbance and dispersal on community assembly play an important, but underappreciated, role in mediating biotic homogenisation and biodiversity responses to environmental change.

The effect of tobacco use on outcomes of laparoscopic and open inguinal hernia repairs: a review of the NSQIP dataset.

BACKGROUND: As the effort to reduce postoperative morbidity and mortality continues, the search for modifiable patient risk factors to reduce complications is ongoing. Tobacco use is associated with impaired wound healing, but its effect on inguinal hernia repair has not been studied in a large population. An ACS-NSQIP dataset was used to evaluate the effect of tobacco use on outcomes of inguinal hernia repairs. METHODS: The ACS-NSQIP dataset was queried for patients who underwent open or laparoscopic inguinal hernia repairs, by primary procedure CPT codes, between years 2009-2012. Tobacco use was registered, as defined by the ACS-NSQIP, in two ways: current smoking (within the past 12 months), or history of smoking (having ever smoked). Univariate and multivariate analyses were used to investigate outcome variables for 30-day morbidity by type of smoking status, while adjusting for preoperative risk factors. RESULTS: During the study period, 90,162 patients underwent inguinal hernia repair. 76 % of the cases were open compared to 24 % laparoscopic. The population was overwhelmingly male, 91 %, compared to 9 % female. The average age of patients was 42.5 years. Of the available data (69 % of patients), 38.5 % had a history of smoking. 18 % had smoked within the 12 months prior to surgery (current smokers). Their average number of pack years was 27.2 (SD 24.0) compared to 4.5 pack years (SD 14.7) for those who had not smoked 12 months prior to surgery (historical smokers). Using Fisher's exact test, having ever smoked was found to be significantly associated with pneumonia (p = 0.0008) and return to the operating room (p = 0.010). This relationship held when preoperative variables were controlled for using logistic regression (pneumonia, p = 0.002; return to the operating room, p = 0.002). When preoperative variables were controlled for and logistic regression was performed for current smokers, there was also a significant association with pneumonia (p = 0.005) and return to the operating room (p = 0.01). CONCLUSION: Current smoking status is a modifiable risk of patients undergoing laparoscopic and open inguinal hernia repair. Failure to quit smoking prior to surgical repair is associated with complications like pneumonia and return to the operating room.

The effect of tobacco use on outcomes of laparoscopic and open ventral hernia repairs: a review of the NSQIP dataset.

INTRODUCTION: Tobacco smoking is a known risk factor for complications after major surgical procedures. The full effect of tobacco use on these complications has not been studied over large populations for ventral hernia repairs. This effect is more important as the preoperative conditioning, and optimization of patients is adopted. We sought to use the prospectively collected ACS-NSQIP dataset to evaluate respiratory and infectious complications for patients undergoing both laparoscopic and open ventral hernia repairs. METHODS: The ACS-NSQIP dataset was queried for patients who underwent open or laparoscopic ventral hernia repairs, by primary procedure CPT codes, between years 2009-2012. Smoking use was registered as defined by the ACS-NSQIP, as both a current smoker (within the prior 12 months) or as a history of smoking (having ever smoked). Univariate and multivariate analyses were used to investigate postoperative complications for 30-day morbidity and mortality by smoking status while adjusting for preoperative risk factors. RESULTS: The majority of cases were open, 82 %, compared to laparoscopic 18 %. Sex was evenly distributed with 58 % female and 42 % male; however, there was a difference in the distribution of current smokers (p = 0.03). On analysis there were significantly more respiratory complications (p = 0.0003) and infectious complications (p < 0.0001). When controlling for sex, age, and type of surgery, using logistic regression, there were associations between smoking in the prior 12 months and respiratory complications, including pneumonia (p < 0.0001), and re-intubation (p < 0.0001). Similar associations were seen on logistic regression if a patient ever smoked; including pneumonia (p < 0.0001), re-intubation (p < 0.0001), and failure to wean (p < 0.0001). CONCLUSION: Smoking tobacco, both current and historical use, leads to an increase in both respiratory and infectious complications. As more centers try to preoperatively condition patients for elective hernia repairs, it is important to note that patients may never return to the baseline outcomes of patients who never smoked.

Quantification of risk factors in 500 patients with postoperative urinary retention.

INTRODUCTION: An Institutional Quality and Safety Initiative to reduce postoperative urinary retention (POUR) and improve patient safety indicators (PSIs) was undertaken after a nurse driven protocol for catheter removal lead to an increase in POUR. The aim of this study was to identify the number of risk factors present in patients with POUR while examining the prevalence of those risk factors individually. MATERIALS AND METHODS: A retrospective review of our institution's surgical database was performed to identify 500 consecutive cases of POUR between July 1, 2013 and July 1, 2014. POUR was defined as the inability to void postoperatively with bladder scan volumes greater than 450 mL and subsequent need for catheterization with an output greater than 450 mL. These records were individually reviewed for 15 known independent risk factors for urinary retention. Patients with incomplete records or preoperative baseline urinary retention requiring catheterization were excluded. RESULTS: Of the 500 consecutive patients with POUR, 288 (57.6%) were male and 212 (42.4%) were female. At the time of voiding trial, all 500 patients with POUR (100%) had at least one perioperative risk factor identified and over 75% had six or more (mean 6.88, median 7, range 1-12). CONCLUSIONS: Multiple perioperative risk factors are present in the vast majority of patients with POUR. Many of the risk factors are modifiable and represent an opportunity for intervention. This could ultimately lead to a risk profile which could be used to optimize timing of postoperative voiding trials, thus improving patient care (improve PSIs and patient comfort, reduce trauma) while maintaining low rates of CAUTI.

Negative density dependence is stronger in resource-rich environments and diversifies communities when stronger for common but not rare species.

Conspecific negative density dependence is thought to maintain diversity by limiting abundances of common species. Yet the extent to which this mechanism can explain patterns of species diversity across environmental gradients is largely unknown. We examined density-dependent recruitment of seedlings and saplings and changes in local species diversity across a soil-resource gradient for 38 woody-plant species in a temperate forest. At both life stages, the strength of negative density dependence increased with resource availability, becoming relatively stronger for rare species during seedling recruitment, but stronger for common species during sapling recruitment. Moreover, negative density dependence appeared to reduce diversity when stronger for rare than common species, but increase diversity when stronger for common species. Our results suggest that negative density dependence is stronger in resource-rich environments and can either decrease or maintain diversity depending on its relative strength among common and rare species.

Using codispersion analysis to quantify and understand spatial patterns in species-environment relationships.

The analysis of spatial patterns in species-environment relationships can provide new insights into the niche requirements and potential co-occurrence of species, but species abundance and environmental data are routinely collected at different spatial scales. Here, we investigate the use of codispersion analysis to measure and assess the scale, directionality and significance of complex relationships between plants and their environment in large forest plots. We applied codispersion analysis to both simulated and field data on spatially located tree species basal area and environmental variables. The significance of the observed bivariate spatial associations between the basal area of key species and underlying environmental variables was tested using three null models. Codispersion analysis reliably detected directionality (anisotropy) in bivariate species-environment relationships and identified relevant scales of effects. Null model-based significance tests applied to codispersion analyses of forest plot data enabled us to infer the extent to which environmental conditions, tree sizes and/or tree spatial positions underpinned the observed basal area-environment relationships, or whether relationships were a result of other unmeasured factors. Codispersion analysis, combined with appropriate null models, can be used to infer hypothesized ecological processes from spatial patterns, allowing us to start disentangling the possible drivers of plant species-environment relationships.

Tree-mycorrhizal associations detected remotely from canopy spectral properties.

A central challenge in global ecology is the identification of key functional processes in ecosystems that scale, but do not require, data for individual species across landscapes. Given that nearly all tree species form symbiotic relationships with one of two types of mycorrhizal fungi - arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) fungi - and that AM- and ECM-dominated forests often have distinct nutrient economies, the detection and mapping of mycorrhizae over large areas could provide valuable insights about fundamental ecosystem processes such as nutrient cycling, species interactions, and overall forest productivity. We explored remotely sensed tree canopy spectral properties to detect underlying mycorrhizal association across a gradient of AM- and ECM-dominated forest plots. Statistical mining of reflectance and reflectance derivatives across moderate/high-resolution Landsat data revealed distinctly unique phenological signals that differentiated AM and ECM associations. This approach was trained and validated against measurements of tree species and mycorrhizal association across ~130 000 trees throughout the temperate United States. We were able to predict 77% of the variation in mycorrhizal association distribution within the forest plots (P < 0.001). The implications for this work move us toward mapping mycorrhizal association globally and advancing our understanding of biogeochemical cycling and other ecosystem processes.

The beta-diversity of species interactions: Untangling the drivers of geographic variation in plant-pollinator diversity and function across scales.

PREMISE OF THE STUDY: Geographic patterns of biodiversity have long inspired interest in processes that shape the assembly, diversity, and dynamics of communities at different spatial scales. To study mechanisms of community assembly, ecologists often compare spatial variation in community composition (beta-diversity) across environmental and spatial gradients. These same patterns inspired evolutionary biologists to investigate how micro- and macro-evolutionary processes create gradients in biodiversity. Central to these perspectives are species interactions, which contribute to community assembly and geographic variation in evolutionary processes. However, studies of beta-diversity have predominantly focused on single trophic levels, resulting in gaps in our understanding of variation in species-interaction networks (interaction beta-diversity), especially at scales most relevant to evolutionary studies of geographic variation. METHODS: We outline two challenges and their consequences in scaling-up studies of interaction beta-diversity from local to biogeographic scales using plant-pollinator interactions as a model system in ecology, evolution, and conservation. KEY RESULTS: First, we highlight how variation in regional species pools may contribute to variation in interaction beta-diversity among biogeographic regions with dissimilar evolutionary history. Second, we highlight how pollinator behavior (host-switching) links ecological networks to geographic patterns of plant-pollinator interactions and evolutionary processes. Third, we outline key unanswered questions regarding the role of geographic variation in plant-pollinator interactions for conservation and ecosystem services (pollination) in changing environments. CONCLUSIONS: We conclude that the largest advances in the burgeoning field of interaction beta-diversity will come from studies that integrate frameworks in ecology, evolution, and conservation to understand the causes and consequences of interaction beta-diversity across scales.