Search

When species simultaneously compete with two or more species of competitor, higher-order interactions (HOIs) can lead to emergent properties not present when species interact in isolated pairs. To extend ecological theory to multi-competitor communities, ecologists must confront the challenges of measuring and interpreting HOIs in models of competition fit to data from nature. Such efforts are hindered by the fact that different studies use different definitions, and these definitions have unclear relationships to one another. Here, we propose a distinction between 'soft' HOIs, which identify possible interaction modification by competitors, and 'hard' HOIs, which identify interactions uniquely emerging in systems with three or more competitors. We show how these two classes of HOI differ in their motivation and interpretation, as well as the tests one uses to identify them in models fit to data. We then show how to operationalise this structure of definitions by analysing the results of a simulated competition experiment underlain by a consumer resource model. In the course of doing so, we clarify the challenges of interpreting HOIs in nature, and suggest a more precise framing of this research endeavour to catalyse further investigations.

Aim: Addressing global environmental challenges requires access to biodiversity data across wide spatial, temporal and taxonomic scales. Availability of such data has increased exponentially recently with the proliferation of biodiversity databases. However, heterogeneous coverage, protocols, and standards have hampered integration among these databases. To stimulate the next stage of data integration, here we present a synthesis of major databases, and investigate (a) how the coverage of databases varies across taxonomy, space, and record type; (b) what degree of integration is present among databases; (c) how integration of databases can increase biodiversity knowledge; and (d) the barriers to database integration. Location: Global. Time period: Contemporary. Major taxa studied: Plants and vertebrates. Methods: We reviewed 12 established biodiversity databases that mainly focus on geographic distributions and functional traits at global scale. We synthesized information from these databases to assess the status of their integration and major knowledge gaps and barriers to full integration. We estimated how improved integration can increase the data coverage for terrestrial plants and vertebrates. Results: Every database reviewed had a unique focus of data coverage. Exchanges of biodiversity information were common among databases, although not always clearly documented. Functional trait databases were more isolated than those pertaining to species distributions. Variation and potential incompatibility of taxonomic systems used by different databases posed a major barrier to data integration. We found that integration of distribution databases could lead to increased taxonomic coverage that corresponds to 23 years’ advancement in data accumulation, and improvement in taxonomic coverage could be as high as 22.4% for trait databases. Main conclusions: Rapid increases in biodiversity knowledge can be achieved through the integration of databases, providing the data necessary to address critical environmental challenges. Full integration across databases will require tackling the major impediments to data integration: taxonomic incompatibility, lags in data exchange, barriers to effective data synchronization, and isolation of individual initiatives.

The complex spatial structure and dynamics of ecological communities continue to defy explanation by simple principles despite decades of attention from ecologists and theoreticians. For example, the relationship between plant spatial distributions and species coexistence is often challenging to resolve in empirical settings. By analysing the spatial patterns of trees in 21 large forest plots we find a general and strong latitudinal gradient in the relationship between conspecific aggregation and abundance of tree species, with stronger negative abundance-dependency as latitude increases. To derive theoretical expectations for how interactions between multiple spatial pattern and processes can impact species coexistence, we incorporate the observed spatial patterns together with neighbourhood crowding competition into a mathematical model to estimate the local extinction risk of species. Strikingly, we find simple relationships that predict species local extinction risk from their demography and spatial distribution. Compared to a corresponding non-spatial analysis, accounting for spatial patterns reduces the 1000-year extinction risk on average by 52% when species invade from low abundances of 50 individuals. Additionally, based on their current abundances, only 8% of the species had an extinction risk greater than 5%. Our approach opens up new avenues for integrating observed spatial patterns with multiple ecological processes into mathematical theory. Our results demonstrate that emerging spatial patterns can contribute substantially to coexistence in species-rich forests, emphasizing the need to understand the interacting multiple processes underpinning spatial patterns in greater detail than has previously been appreciated.

As Earth's climate has varied strongly through geological time, studying the impacts of past climate change on biodiversity helps to understand the risks from future climate change. However, it remains unclear how paleo-climate shapes spatial variation in biodiversity. Here, we assessed the influence of Quaternary climate change on spatial dissimilarity in taxonomic, phylogenetic, and functional composition among neighboring 200-kilometer cells (beta-diversity) for angiosperm trees worldwide. We found that larger glacial-interglacial temperature change was strongly associated with lower spatial turnover (species replacements) and higher nestedness (rich-ness changes) components of beta-diversity across all three biodiversity facets. Moreover, phylogenetic and functional turnover was lower and nestedness higher than random expectations based on taxonomic beta -di-versity in regions that experienced large temperature change, reflecting phylogenetically and functionally se-lective processes in species replacement, extinction, and colonization during glacial-interglacial oscillations. Our results suggest that future human-driven climate change could cause local homogenization and reduction in taxonomic, phylogenetic, and functional diversity of angiosperm trees worldwide. W.-B.X. and A.O. acknowledge support from the Aarhus University Research Foundation (AUFF) Starting Grant (AUFF-F-2018-7-8). J.-C.S. acknowledges support from the Danish Council for Independent Research|Natural Sciences (grant 6108-00078B) to the TREECHANGE Project. J.-C.S. also considers this work a contribution to the Center for Ecological Dynamics in a Novel Biosphere (ECONOVO) funded by Danish National Research Foundation (grant DNRF173) and the VILLUM Investigator project “Biodiversity Dynamics in a Changing World” funded by VILLUM FONDEN (grant 16549). W.L.E. was supported by the VILLUM FONDEN (grant 00025354). M.A. was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery grants program. C.B. was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (2022R1A2C1003504). A.G.G. was supported by the ANID PIA/BASAL (grant FB210006) and FONDECYT (grant 1200468). R.E.O. was supported by the German Research Foundation to German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig (DFG-FZT 118, 202548816). J.Pe. was supported by the Fundación Ramón Areces project (CIVP20A6621) and Spanish Government project (PID2019-110521GB-I00). J.Pi. was supported by the Estonian Research Council Grants (PUT1355, PRG 1405) and Mobilitas Pluss (MOBERC11). V.D.P. was supported by the National Council of Scientific and Technological Development (CNPq) of Brazil (grant 307689/2014-0).

High and equitable COVID-19 vaccination coverage is important for pandemic control and prevention of health inequity. However, little is known about socioeconomic correlates of booster vaccination coverage. In this cross-sectional study of all Norwegian adults in the national vaccination program (N = 4,190,655), we use individual-level registry data to examine coverage by levels of household income and education of primary (≥2 doses) and booster (≥3 doses) vaccination against COVID-19. We stratify the analyses by age groups with different booster recommendations and report relative risk ratios (RR) for vaccination by 25 August 2022. In the 18-44 years group, individuals with highest vs. lowest education had 94% vs. 79% primary coverage (adjusted RR (adjRR) 1.15, 95%CI 1.14-1.15) and 67% vs. 38% booster coverage (adjRR 1.55, 95% CI 1.55-1.56), while individuals with highest vs. lowest income had 94% vs. 81% primary coverage (adjRR 1.10, 95%CI 1.10-1.10) and 60% vs. 43% booster coverage (adjRR 1.23, 95%CI 1.22-1.24). In the≥45 years group, individuals with highest vs. lowest education had 96% vs. 92% primary coverage (adjRR 1.02, 95%CI 1.02-1.02) and 88% vs. 80% booster coverage (adjRR 1.09, 95%CI 1.09-1.09), while individuals with highest vs. lowest income had 98% vs. 82% primary coverage (adjRR 1.16, 95%CI 1.16-1.16) and 92% vs. 64% booster coverage (adjRR 1.33, 95%CI 1.33-1.34). In conclusion, we document large socioeconomic inequalities in COVID-19 vaccination coverage, especially for booster vaccination, even though all vaccination was free-of-charge. The results highlight the need to tailor information and to target underserved groups for booster vaccination.

The targeted degradation of histone deacetylase 6 (HDAC6) by heterobifunctional degraders constitutes a promising approach to treat HDAC6-driven diseases. Previous HDAC6 selective degraders utilised a hydroxamic acid as a zinc-binding group (ZBG) which features mutagenic and genotoxic potential. Here we report the development of a new class of selective HDAC6 degraders based on a difluoromethyl-1,3,4-oxadiazole warhead as ZBG.

Histone deacetylases (HDACs) play a key role in the control of transcription, cell proliferation, and migration. FDA-approved histone deacetylase inhibitors (HDACi) demonstrate clinical efficacy in the treatment of different T-cell lymphomas and multiple myeloma. However, due to unselective inhibition, they display a wide range of adverse effects. One approach to avoiding off-target effects is the use of prodrugs enabling a controlled release of the inhibitor in the target tissue. Herein, we describe the synthesis and biological evaluation of HDACi prodrugs with photo-cleavable protecting groups masking the zinc-binding group of the established HDACi DDK137 (I) and VK1 (II). Initial decaging experiments confirmed that the photocaged HDACi pc-I could be deprotected to its parent inhibitor I. In HDAC inhibition assays, pc-I displayed only low inhibitory activity against HDAC1 and HDAC6. After irradiation with light, the inhibitory activity of pc-I strongly increased. Subsequent MTT viability assays, whole-cell HDAC inhibition assays, and immunoblot analysis confirmed the inactivity of pc-I at the cellular level. Upon irradiation, pc-I demonstrated pronounced HDAC inhibitory and antiproliferative activities which were comparable to the parent inhibitor I. Additionally, only phototreated pc-I was able to induce apoptosis in Annexin V/PI and caspase-Glo 3/7 assays, making pc-I a valuable tool for the development of light-activatable HDACi.

Funding: Floristic identification in plots in the RAINFOR forest monitoring network have been supported by the Natural Environment Research Council (grants NE/B503384/1, NE/ D01025X/1, NE/I02982X/1, NE/F005806/1, NE/D005590/1 and NE/I028122/1) and the Gordon and Betty Moore Foundation. In a time of rapid global change, the question of what determines patterns in species abundance distribution remains a priority for understanding the complex dynamics of ecosystems. The constrained maximization of information entropy provides a framework for the understanding of such complex systems dynamics by a quantitative analysis of important constraints via predictions using least biased probability distributions. We apply it to over two thousand hectares of Amazonian tree inventories across seven forest types and thirteen functional traits, representing major global axes of plant strategies. Results show that constraints formed by regional relative abundances of genera explain eight times more of local relative abundances than constraints based on directional selection for specific functional traits, although the latter does show clear signals of environmental dependency. These results provide a quantitative insight by inference from large-scale data using cross-disciplinary methods, furthering our understanding of ecological dynamics. Publisher PDF

Minimally displaced fractures of the lateral humeral condyle (LHC) may be treated nonoperatively in a long arm cast, but there is not a standardized evidence-based protocol. The aim of this study was to evaluate our nonoperatively treated LHC fractures, determine the risk of subsequent displacement, analyze our practice variability, and develop an evidence-based protocol to safely manage children with LHC fractures and to evaluate potential savings related to this analysis.We retrospectively reviewed clinical and radiographic parameters of all patients with LHC fractures at our institution from 2009 to 2015. All patients treated nonoperatively initially were included. We recorded demographic data and calculated the number of visits, casts applied, and radiographs within the first 4 weeks. We also analyzed practice variation among 27 treating providers. The number of children with subsequent displacement needing operative fixation was determined. We also looked at the average duration for each follow-up visit and the charges/costs associated with casting and radiographs.There were 271 children with LHC fractures treated nonoperatively. Twenty-one were excluded because of the lack of adequate radiographs. There were 157 boys and 93 girls (average age 6.7 y). According to the Jakob classification, fracture types were as follows: 1 (230), 2 (20), and 3 (0). Within the first 4 weeks, the average number of visits was 2.6 (range: 1 to 5), average number of casts was 2.4 (range: 1 to 4), and the average number of radiographs was 9.4 (range: 2 to 31). Only 3 patients with LHC fracture type Jakob 1 were taken to the operating room post injury (9, 12, and 15 d, respectively) for subsequent displacement.Displacement in appropriately selected LHC fractures treated nonoperatively was rare (3/250, 1.2%) in this cohort, and the data question the need for multiple visits and radiographs in the first 4 weeks. Optimal follow-up (proposed follow-up at 10 to 15 d after injury and then 4 to 6 wk with radiographs, including an internal oblique view) would be safe, minimize waste, and result in better value-based care.Level IV.

Safeguarding Earth?s tree diversity is a conservation priority due to the importance of trees for biodiversity and ecosystem functions and services such as carbon sequestration. Here, we improve the foundation for effective conservation of global tree diversity by analyzing a recently developed database of tree species covering 46,752 species. We quantify range protection and anthropogenic pressures for each species and develop conservation priorities across taxonomic, phylogenetic, and functional diversity dimensions. We also assess the effectiveness of several influential proposed conservation prioritization frameworks to protect the top 17% and top 50% of tree priority areas. We find that an average of 50.2% of a tree species? range occurs in 110-km grid cells without any protected areas (PAs), with 6,377 small-range tree species fully unprotected, and that 83% of tree species experience nonnegligible human pressure across their range on average. Protecting highpriority areas for the top 17% and 50% priority thresholds would increase the average protected proportion of each tree species? range to 65.5% and 82.6%, respectively, leaving many fewer species (2,151 and 2,010) completely unprotected. The priority areas identified for trees match well to the Global 200 Ecoregions framework, revealing that priority areas for trees would in large part also optimize protection for terrestrial biodiversity overall. Based on range estimates for >46,000 tree species, our findings show that a large proportion of tree species receive limited protection by current PAs and are under substantial human pressure. Improved protection of biodiversity overall would also strongly benefit global tree diversity. Made available in DSpace on 2022-06-21T15:23:55Z (GMT). No. of bitstreams: 1 Guo-et-al.-2022-PNAS-High-exposure-of-global-tree-diversity-to-human-pressure.pdf: 2523289 bytes, checksum: 245be3df3fb487ed152d25bf50f4e984 (MD5) Previous issue date: 2022 Proceedings of the National Academy of Sciences of the United States of America.

Plant species can show considerable morphological and functional variation along environmental gradients. This intraspecific trait variation (ITV) can have important consequences for community assembly, biotic interactions, ecosystem functions and responses to global change. However, directly measuring ITV across many species and wide geographic areas is often infeasible. Thus, a method to predict spatial variation in a species’ functional traits could be valuable. We measured specific leaf area (SLA), height and leaf area (LA) of grasses across California, covering 59 species at 230 sampling locations. We asked how these traits change along climate gradients within each species and used machine learning to predict local trait values for any species at any location based on phylogenetic position, local climate and that species’ mean traits. We then examined how much these local predictions alter patterns of assemblage-level trait variation across the state. Most species exhibited higher SLA and grew taller at higher temperatures and produced larger leaves in drier conditions. The random forests predicted spatial variation in functional traits very accurately, with correlations up to 0.97. Because trait records were spatially biased towards warmer areas, and these areas tend to have higher SLA individuals within each species, species means of SLA were upwardly biased. As a result, using species means over-estimates SLA in the cooler regions of the state. Our results also suggest that height may be substantially under-predicted in the warmest areas. Synthesis. Using only species mean traits to characterize the functional composition of communities risks introducing substantial error into trait-based estimates of ecosystem properties including decomposition rates or NPP. The high performance of random forests in predicting local trait values provides a way forward for estimating high-resolution patterns of ITV without a massive data collection effort.

Climate change is leading to habitat shifts that threaten species persistence throughout California's unique ecosystems. Baseline biodiversity data would provide opportunities for habitats to be managed under short-term and long-term environmental change. Aiming to provide biodiversity data, the UC Conservation Genomics Consortium launched the California Environmental DNA (CALeDNA) program to be a citizen and community science biomonitoring initiative that uses environmental DNA (eDNA, DNA shed from organisms such as from fur, feces, spores, pollen or leaves). Now with results from 1,000 samples shared online, California biodiversity patterns are discoverable. Soil, sediment and water collected by researchers, undergraduates and the public reveal a new catalog of thousands of organisms that only slightly overlap with traditional survey bioinventories. The CALeDNA website lets users explore the taxonomic diversity in different ways, and researchers have created tools to help people new to eDNA to analyze community ecology patterns. Although eDNA results are not always precise, the program team is making progress to fit it into California's biodiversity management toolbox, such as for monitoring ecosystem recovery after invasive species removal or wildfire.

A 10-year-old girl sustained a radial neck fracture with a posterior elbow dislocation. She was treated with closed reduction of the elbow with subsequent intra-articular displacement of the radial head, which necessitated open reduction and pinning of the radial neck fracture.Displacement of the radial neck fracture from impingement of the capitellum on the anterior radial head during closed reduction of the elbow dislocation is a rare injury pattern. It is important to examine the radial neck in high-energy posterior elbow dislocations before attempted reduction. We present a case with imaging depicting the injury mechanism and successful management with subsequent open reduction and fixation of the radial neck fracture.

Aim: Here we examine the functional profile of regional tree species pools across the latitudinal distribution of Neotropical moist forests, and test trait–climate relationships among local communities. We expected opportunistic strategies (acquisitive traits, small seeds) to be overrepresented in species pools further from the equator, but also in terms of abundance in local communities in currently wetter, warmer and more seasonal climates. Location: Neotropics. Time period: Recent. Major taxa studied: Trees. Methods: We obtained abundance data from 471 plots across nine Neotropical regions, including c. 100,000 trees of 3,417 species, in addition to six functional traits. We compared occurrence-based trait distributions among regional species pools, and evaluated single trait–climate relationships across local communities using community abundance-weighted means (CWMs). Multivariate trait–climate relationships were assessed by a double-constrained correspondence analysis that tests both how CWMs relate to climate and how species distributions, parameterized by niche centroids in climate space, relate to their traits. Results: Regional species pools were undistinguished in functional terms, but opportunistic strategies dominated local communities further from the equator, particularly in the Northern Hemisphere. Climate explained up to 57% of the variation in CWM traits, with increasing prevalence of lower-statured, light-wooded and softer-leaved species bearing smaller seeds in more seasonal, wetter and warmer climates. Species distributions were significantly but weakly related to functional traits. Main conclusions: Neotropical moist forest regions share similar sets of functional strategies, from which local assembly processes, driven by current climatic conditions, select for species with different functional strategies. We can thus expect functional responses to climate change driven by changes in relative abundances of species already present regionally. Particularly, equatorial forests holding the most conservative traits and large seeds are likely to experience the most severe changes if climate change triggers the proliferation of opportunistic tree species.

Cannabis ist die weltweit am haufigsten konsumierte Droge. Medizinisches Cannabis, naturliche und synthetische Cannabinoide finden zunehmend Akzeptanz in der Medizin und werden von vielen Patienten zur Linderung von Schmerzen und anderer Beschwerden verwendet. Erste klinische Daten weisen auf einen erhohten Bedarf an Anasthetika und Analgetika bei Cannabiskonsumenten hin. Der Artikel fasst daher die aktuelle Literatur zu Auswirkungen und potenziellen Risiken von Cannabis/Cannabinoiden fur die perioperative Phase zusammen. Neben einem signifikant erhohten Bedarf an Propofol und Fentanyl bei der Narkose und einem erhohten postoperativen Analgetikabedarf besteht zudem ein hoheres Risiko fur das Auftreten von Tachykardien, pulmonalen oder thromboembolischen Komplikationen. Daher wird empfohlen, Patienten praoperativ gezielt nach Cannabiskonsum oder der Einnahme von cannabisbasierten Medikamenten zu fragen.

This is a case of a 7-year-old boy with a Lisfranc injury identified on weight-bearing films who was treated successfully with closed reduction with a clamp and smooth pin fixation. This patient returned to sports without pain or radiographic signs of arthritis at 1 year.Lisfranc fractures and ligamentous injuries are rare and can occur in skeletally immature children. They have high potential for long-term disability if not properly diagnosed and treated. Although there is no consensus on optimal management of pediatric Lisfranc injuries, restoration of an anatomic Lisfranc joint with smooth pins and immobilization for 6 weeks is a viable treatment option.

Contemporary studies of species coexistence are underpinned by deterministic models that assume that competing species have continuous (i.e., noninteger) densities, live in infinitely large landscapes, and coexist over infinite time horizons. By contrast, in nature, species are composed of discrete individuals subject to demographic stochasticity and occur in habitats of finite size where extinctions occur in finite time. One consequence of these discrepancies is that metrics of species' coexistence derived from deterministic theory may be unreliable predictors of the duration of species coexistence in nature. These coexistence metrics include invasion growth rates and niche and fitness differences, which are now commonly applied in theoretical and empirical studies of species coexistence. In this study, we tested the efficacy of deterministic coexistence metrics on the duration of species coexistence in a finite world. We introduce new theoretical and computational methods to estimate coexistence times in stochastic counterparts of classic deterministic models of competition. Importantly, we parameterized this model using experimental field data for 90 pairwise combinations of 18 species of annual plants, allowing us to derive biologically informed estimates of coexistence times for a natural system. Strikingly, we found that for species expected to deterministically coexist, community sizes containing only 10 individuals had predicted coexistence times of more than 1000 years. We also found that invasion growth rates explained 60% of the variation in intrinsic coexistence times, reinforcing their general usefulness in studies of coexistence. However, only by integrating information on both invasion growth rates and species' equilibrium population sizes could most (99%) of the variation in species coexistence times be explained. This integration was achieved with demographically uncoupled single-species models solely determined by the invasion growth rates and equilibrium population sizes. Moreover, because of a complex relationship between niche overlap/fitness differences and equilibrium population sizes, increasing niche overlap and increasing fitness differences did not always result in decreasing coexistence times, as deterministic theory would predict. Nevertheless, our results tend to support the informed use of deterministic theory for understanding the duration of species' coexistence while highlighting the need to incorporate information on species' equilibrium population sizes in addition to invasion growth rates.

Caregivers of children with cerebral palsy (CP) experience stress surrounding orthopaedic surgery related to their child’s pain and recovery needs. Social determinants of health can affect the severity of this stress and hinder health care delivery. A preoperative biopsychosocial assessment (BPSA) can identify risk factors and assist in alleviating psychosocial risk. This study examined the relationship between the completion of a BPSA, hospital length of stay (LOS), and 30-day readmission rates for children with CP who underwent hip reconstruction (HR) or posterior spinal fusion (PSF). Outcomes were compared with a matched group who did not have a preoperative BPSA. The BPSA involved meeting with a social worker to discuss support systems, financial needs, transportation, equipment, housing, and other services. A total of 92 children (28 HR pairs, 18 PSF pairs) were identified. Wilcoxon analysis was statistically significant (p = 0.000228) for shorter LOS in children who underwent PSF with preoperative BPSA (median = 7.0 days) vs. without (median = 12.5 days). Multivariate analysis showed that a BPSA, a lower Gross Motor Function Classification System level, and fewer comorbidities were associated with a shorter LOS after both PSF and HR (p < 0.05). Identifying and addressing the psychosocial needs of patients and caregivers prior to surgery can lead to more timely discharge postoperatively.

Herein we report the structure-activity and structure-physicochemical property relationships of a series of class I selective ortho-aminoanilides targeting the "foot-pocket" in HDAC12. To balance the structural benefits and the physicochemical disadvantages of these substances, we started with a set of HDACi related to tacedinaline (CI-994) and evaluated their solubility, lipophilicity (log D

Artemisinin-based combination therapies (ACTs) are the gold standard for the treatment of malaria, but the efficacy is threatened by the development of parasite resistance. Histone deacetylase inhibitors (HDACis) are an emerging new class of potential antiplasmodial drugs. In this work, we present the design, synthesis, and biological evaluation of a mini library of dihydroartemisinin–HDACi hybrid molecules. The screening of the hybrid molecules for their activity against selected human HDAC isoforms, asexual blood stage P. falciparum parasites, and a panel of leukemia cell lines delivered important structure–activity relationships. All synthesized compounds demonstrated potent activity against the 3D7 and Dd2 line of P. falciparum with IC50 values in the single-digit nanomolar range. Furthermore, the hybrid (α)-7c displayed improved activity against artemisinin-resistant parasites compared to dihydroartemisinin. The screening of the compounds against five cell lines from different leukemia entities revealed that all hydroxamate-based hybrids (7a–e) and the ortho-aminoanilide 8 exceeded the antiproliferative activity of dihydroartemisinin in four out of five cell lines. Taken together, this series of hybrid molecules represents an excellent starting point toward the development of antimalarial and antileukemia drug leads.

Plant functional traits can predict community assembly and ecosystem functioning and are thus widely used in global models of vegetation dynamics and land–climate feedbacks. Still, we lack a global understanding of how land and climate affect plant traits. A previous global analysis of six traits observed two main axes of variation: (1) size variation at the organ and plant level and (2) leaf economics balancing leaf persistence against plant growth potential. The orthogonality of these two axes suggests they are differently influenced by environmental drivers. We find that these axes persist in a global dataset of 17 traits across more than 20,000 species. We find a dominant joint effect of climate and soil on trait variation. Additional independent climate effects are also observed across most traits, whereas independent soil effects are almost exclusively observed for economics traits. Variation in size traits correlates well with a latitudinal gradient related to water or energy limitation. In contrast, variation in economics traits is better explained by interactions of climate with soil fertility. These findings have the potential to improve our understanding of biodiversity patterns and our predictions of climate change impacts on biogeochemical cycles., Nature Ecology & Evolution, 6 (1), ISSN:2397-334X

Although precipitation patterns have long been known to shape plant distributions

Glycans are ubiquitous and play important biological roles, yet chemical methods for probing their structure and function within cells remain limited. Strategies for studying other biomacromolecules, such as proteins, often exploit chemoselective reactions for covalent modification, capture, or imaging. Unlike amino acids that constitute proteins, glycan building blocks lack distinguishing reactivity because they are composed primarily of polyol isomers. Moreover, encoding glycan variants through genetic manipulation is complex. Therefore, we formulated a new, generalizable strategy for chemoselective glycan modification that directly takes advantage of cellular glycosyltransferases. Many of these enzymes are selective for the products they generate yet promiscuous in their donor preferences. Thus, we designed reagents with bioorthogonal handles that function as glycosyltransferase substrate surrogates. We validated the feasibility of this approach by synthesizing and testing probes of d-arabinofuranose (d-Araf), a monosaccharide found in bacteria and an essential component of the cell wall that protects mycobacteria, including Mycobacterium tuberculosis. The result is the first probe capable of selectively labeling arabinofuranose-containing glycans. Our studies serve as a platform for developing new chemoselective labeling agents for other privileged monosaccharides. This probe revealed an asymmetric distribution of d-Araf residues during mycobacterial cell growth and could be used to detect mycobacteria in THP1-derived macrophages.

Neighborhood models have allowed us to test many hypotheses regarding the drivers of variation in tree growth, but require considerable computation due to the many empirically supported non-linear relationships they include. Regularized regression represents a far more efficient neighborhood modeling method, but it is unclear whether such an ecologically unrealistic model can provide accurate insights on tree growth. Rapid computation is becoming increasingly important as ecological datasets grow in size, and may be essential when using neighborhood models to predict tree growth beyond sample plots or into the future. We built a novel regularized regression model of tree growth and investigated whether it reached the same conclusions as a commonly used neighborhood model, regarding hypotheses of how tree growth is influenced by the species identity of neighboring trees. We also evaluated the ability of both models to interpolate the growth of trees not included in the model fitting dataset. Our regularized regression model replicated most of the classical model’s inferences in a fraction of the time without using high-performance computing resources. We found that both methods could interpolate out-of-sample tree growth, but the method making the most accurate predictions varied among focal species. Regularized regression is particularly efficient for comparing hypotheses because it automates the process of model selection and can handle correlated explanatory variables. This feature means that regularized regression could also be used to select among potential explanatory variables (e.g., climate variables) and thereby streamline the development of a classical neighborhood model. Both regularized regression and classical methods can interpolate out-of-sample tree growth, but future research must determine whether predictions can be extrapolated to trees experiencing novel conditions. Overall, we conclude that regularized regression methods can complement classical methods in the investigation of tree growth drivers and represent a valuable tool for advancing this field toward prediction., Forests, 12 (9), ISSN:1999-4907

Latitudinal and elevational richness gradients have received much attention from ecologists but there is little consensus on underlying causes. One possible proximate cause is increased levels of species turnover, or β diversity, in the tropics compared to temperate regions. Here, we leverage a large botanical dataset to map taxonomic and phylogenetic β diversity, as mean turnover between neighboring 100 × 100 km cells, across the Americas and determine key climatic drivers. We find taxonomic and tip-weighted phylogenetic β diversity is higher in the tropics, but that basal-weighted phylogenetic β diversity is highest in temperate regions. Supporting Janzen's ‘mountain passes’ hypothesis, tropical mountainous regions had higher β diversity than temperate regions for taxonomic and tip-weighted metrics. The strongest climatic predictors of turnover were average temperature and temperature seasonality. Taken together, these results suggest β diversity is coupled to latitudinal richness gradients and that temperature is a major driver of plant community composition and change.

The unprecedented phospha-aza-Diels-Alder reaction between an activated electron-poor imine and 2H-phospholes yields 1-phospha-2-azanorbornenes in a highly chemoselective and moderately diastereoselective reaction. The intermediate 2H-phospholes, which act as dienes, are formed in situ from the corresponding 1H-phospholes. Theoretical calculations confirm that the phospha-aza-Diels-Alder reaction is of normal electron demand. The reactive P-N bond in 1-phospha-2-azanorbornenes can be cleaved by nucleophiles leading to the formation of 2,3-dihydrophospholes.

PurposeIt is well known that job stress is major cause of salesperson job dissatisfaction and turnover. Salespeople require the resources to cope adequately with a multitude of job stressors, and the purpose of this study is to demonstrate that salesperson wellness promotes the ability of salespeople to use effective coping strategies in the workplace and as a result decrease their intentions of leaving the firm.Design/methodology/approachData including measures of coping strategies and a wellness lifestyle orientation were collected from a sample of 441 full-time professional salespeople in two metropolitan statistical areas of the USA. Structural equation modeling was used to demonstrate the relationship of a wellness lifestyle to coping strategies and in turn the relationship of coping strategies to job satisfaction and turnover intentions.FindingsThe study demonstrated the influence of the wellness lifestyle on salespeople’s ability to cope effectively with job stress. It extends previous research by demonstrating the direct influence of salesperson wellness on coping behaviors and demonstrates the nomological validity of the wellness lifestyle construct by modeling its relationship with job satisfaction and the intent to leave the organization.Research limitations/implicationsThe study recommends new research on the synergies that might be produced by simultaneous consideration of the social, physical, and psychological elements of the multicomponent wellness lifestyle. This should be particularly valuable in the context of the Challenger Sale.Practical implicationsWellness programs may be introduced or improved following an assessment of coping resource weaknesses of the sales force. New employees could be screened by examining their wellness profiles.Originality/valueMajor firms have promoted wellness lifestyle programs for years, but no studies have examined the influence of such programs on coping with job stress by salespeople. The paper demonstrates the value of the salesperson wellness lifestyle by showing that it promotes the most adjustive form of coping strategy, problem-focused coping.

Glycans are ubiquitous and play important biological roles, yet chemical methods for probing their structure and function within cells remain limited. Strategies for studying other biomacromolecules, such as proteins, often exploit chemoselective reactions for covalent modification, capture, or imaging. Unlike amino acids that constitute proteins, glycan building blocks lack distinguishing reactivity because they are composed primarily of polyol isomers. Moreover, encoding glycan variants through genetic manipulation is complex. Therefore, we formulated a new, generalizable strategy for chemoselective glycan modification that directly takes advantage of cellular glycosyltransferases. Many of these enzymes are selective for the products they generate yet promiscuous in their donor preferences. Thus, we designed reagents with bioorthogonal handles that function as glycosyltransferase substrate surrogates. We validated the feasibility of this approach by synthesizing and testing probes of D-arabinofuranose (D-Araf), a monosaccharide found in bacteria and an essential component of the cell wall that protects mycobacteria, including Mycobacterium tuberculosis. The result is the first probe capable of selectively labeling arabinofuranose-containing glycans. Our studies serve as a platform for developing new chemoselective labeling agents for other privileged monosaccharides. This probe revealed an asymmetric distribution of D-Araf residues during mycobacterial cell growth and could be used to detect mycobacteria in THP1-derived macrophages.

Soil microorganisms influence a variety of processes in plant communities. Many theoretical and empirical studies have shown that dynamic feedbacks between plants and soil microbes can stabilize plant coexistence by generating negative frequency-dependent plant population dynamics. However, inferring the net effects of soil microbes on plant coexistence requires also quantifying the degree to which they provide one species an average fitness advantage, an effect that has received little empirical attention. We conducted a greenhouse study to quantify microbially mediated stabilization and fitness differences among 15 pairs of annual plants that co-occur in southern California grasslands. We found that although soil microbes frequently generate negative frequency-dependent dynamics that stabilize plant interactions, they simultaneously generate large average fitness differences between species. The net result is that if the plant species are otherwise competitively equivalent, the impact of plant-soil feedbacks is to often favor species exclusion over coexistence, a result that becomes evident only by quantifying the microbially mediated fitness difference. Our work highlights that comparing the stabilizing effects of plant-soil feedbacks to the fitness difference they generate is essential for understanding the influence of soil microbes on plant diversity.

Turnover in species composition and community-wide functional traits across environmental gradients is a ubiquitous pattern in ecology, and is generally assumed to reflect shifts in trait optima across these gradients. However, the demographic processes that give rise to these trait turnover patterns at the community level remain unclear.We asked whether shifts in the community-weighted means of three key functional traits across an environmental gradient in a southern California grassland reflect variation in the trait-performance relationship across the landscape.We planted seeds of 17 annual plant species in cleared patches with no competitors, and quantified the lifetime seed production of 1360 individuals. We then asked whether models that included trait-environment interactions help explain interspecific variation in demographic responses to the environment. This allowed us to evaluate whether observed shifts in community-weighted mean traits matched the direction of any trait-environment interactions detected in the plant performance experiment.Our results indicate that commonly-measured plant functional traits help explain variation in species responses to the environment – for example, high-SLA species had a demographic advantage in soils with high soil Ca:Mg levels, while low-SLA species had an advantage in low Ca:Mg soils. We also found that shifts in community-weighted mean traits often reflect the direction of these trait-environment interactions, though not all trait-environment relationships at the community level reflect interactive effects of traits and environment on species performance.Our results support the value of plant functional traits for predicting species responses to environmental variation, and highlight a need for more detailed evaluation of how trait-performance relationships change across environments to improve such predictions.

It has been increasingly argued that ecological restoration should focus more on targeting ecosystem services than on species composition of reference ecosystems. In this sense, the role that species play on community assembly and functioning through their functional traits is very relevant, because effect traits mediate ecosystem processes, ultimately resulting in provision of ecosystem services. One major challenge in ecological restoration is to know which species to use that will deliver the target ecosystem services. We developed an algorithm to select the minimum set of species that maximize the functional richness (FRic) and the functional redundancy (FR) of the restored community, a proxy for the provision of multiple ecosystem services and the resilience of the system to environmental changes, respectively. For this, we simulated the restoration of 24 riparian woody communities of the Brazilian Cerrado. Using the species pool of each original local community, we ran restoration simulations for gradually increasing species richness until reaching the total species richness of the original local community. We computed FRic and FR for each simulated restoration community using the traits specific leaf area, maximum plant height and seed mass. Our simulation results indicate that multiple ecosystem services could be restored with an average of 66% of the species of the original community. Moreover, an average of 59% of the species would be needed to restore communities resilient to environmental changes. Our approach contributes to solving one of the major challenges of ecological restoration, which is defining how many and which species should be used to achieve functional targets. We believe this approach can help in projects of restoration by enabling restoration practitioners to select minimum alternative sets of species that optimize the provision of multiple ecosystem services in a resilient restored ecosystem.