Background invertebrate herbivory on dwarf birch (Betula glandulosa-nana complex) increases with temperature and precipitation across the tundra biome

Chronic, low intensity herbivory by invertebrates, termed background herbivory, has been understudied in tundra, yet its impacts are likely to increase in a warmer Arctic. The magnitude of these changes is however hard to predict as we know little about the drivers of current levels of invertebrate herbivory in tundra. We assessed the intensity of invertebrate herbivory on a common tundra plant, the dwarf birch (Betula glandulosa-nana complex), and investigated its relationship to latitude and climate across the tundra biome. Leaf damage by defoliating, mining and gall-forming invertebrates was measured in samples collected from 192 sites at 56 locations. Our results indicate that invertebrate herbivory is nearly ubiquitous across the tundra biome but occurs at low intensity. On average, invertebrates damaged 11.2% of the leaves and removed 1.4% of total leaf area. The damage was mainly caused by external leaf feeders, and most damaged leaves were only slightly affected (12% leaf area lost). Foliar damage was consistently positively correlated with mid-summer (July) temperature and, to a lesser extent, precipitation in the year of data collection, irrespective of latitude. Our models predict that, on average, foliar losses to invertebrates on dwarf birch are likely to increase by 6–7% over the current levels with a 1 °C increase in summer temperatures. Our results show that invertebrate herbivory on dwarf birch is small in magnitude but given its prevalence and dependence on climatic variables, background invertebrate herbivory should be included in predictions of climate change impacts on tundra ecosystems. © 2017 Springer-Verlag GmbH GermanyAdditional co-authors: Katherine S. Christie, Yulia V. Denisova, Dagmar Egelkraut, Dorothee Ehrich, LeeAnn Fishback, Bruce C. Forbes, Maite Gartzia, Paul Grogan, Martin Hallinger, Monique M. P. D. Heijmans, David S. Hik, Annika Hofgaard, Milena Holmgren, Toke T. Høye, Diane C. Huebner, Ingibjorg Svala Jonsdottir, Elina Kaarlejarvi, Timo Kumpula, Cynthia Y. M. J. G. Lange, Jelena Lange, Esther Levesque, Juul Limpens, Marc Macias-Fauria, Isla Myers-Smith, Erik J. van Nieukerken, Signe Normand, Eric S. Post, Niels Martin Schmidt, Judith Sitters, Anna Skoracka, Alexander Sokolov, Natalya Sokolova, James D. M. Speed, Lorna E. Street, Maja K. Sundqvist, Otso Suominen, Nikita Tananaev, Jean-Pierre Tremblay, Christine Urbanowicz, Sergey A. Uvarov, David Watts, Martin Wilmking, Heike H. Zimmermann, Vitali Zverev, Mikhail V. Kozlo

Circum-Arctic distribution of chemical anti-herbivore compounds suggests biome-wide trade-off in defence strategies in Arctic shrubs

Spatial variation in plant chemical defence towards herbivores can help us understand variation in herbivore top-down control of shrubs in the Arctic and possibly also shrub responses to global warming. Less defended, non-resinous shrubs could be more influenced by herbivores than more defended, resinous shrubs. However, sparse field measurements limit our current understanding of how much of the circum-Arctic variation in defence compounds is explained by taxa or defence functional groups (resinous/non-resinous). We measured circum-Arctic chemical defence and leaf digestibility in resinous (Betula glandulosa, B. nana ssp. exilis) and non-resinous (B. nana ssp. nana, B. pumila) shrub birches to see how they vary among and within taxa and functional groups. Using liquid chromatography-mass spectrometry (LC-MS) metabolomic analyses and in vitro leaf digestibility via incubation in cattle rumen fluid, we analysed defence composition and leaf digestibility in 128 samples from 44 tundra locations. We found biogeographical patterns in anti-herbivore defence where mean leaf triterpene concentrations and twig resin gland density were greater in resinous taxa and mean concentrations of condensing tannins were greater in non-resinous taxa. This indicates a biome-wide trade-off between triterpene- or tannin-dominated defences. However, we also found variations in chemical defence composition and resin gland density both within and among functional groups (resinous/non-resinous) and taxa, suggesting these categorisations only partly predict chemical herbivore defence. Complex tannins were the only defence compounds negatively related to in vitro digestibility, identifying this previously neglected tannin group as having a potential key role in birch anti-herbivore defence. We conclude that circum-Arctic variation in birch anti-herbivore defence can be partly derived from biogeographical distributions of birch taxa, although our detailed mapping of plant defence provides more information on this variation and can be used for better predictions of herbivore effects on Arctic vegetation

Unlocking pre-1850 instrumental meteorological records

A global inventory of early instrumental meteorological measurements is compiled that comprises thousands of mostly nondigitized series, pointing to the potential or weather data rescu

Intersectionality in nursing research: A systematic review

Abstract Aim This systematic literature review aimed to identify, appraise and synthesize available research studies that apply intersectionality in nursing research. Design Systematic review. Data Sources Empirical and theoretical nursing studies published before February 2022 were identified from the PubMed and CINAHL databases. Studies were eligible for inclusion if they substantially covered the topics of intersectionality and nursing, had undergone peer‐review, and were written in English. Review Methods The PRISMA 2020 statement for reporting systematic reviews was used to report findings. The Joanna Briggs Institute Critical Appraisal tools were used to assess the quality of the included research studies. Results Out of 331 identified studies, 60 studies were substantially about nursing and intersectionality, and were included in the review. There are a myriad of ways that the concept of intersectionality has been adopted in nursing research. Furthermore, there was great heterogeneity in the definition and application of the concept of intersectionality, and only a few studies were empirical. Conclusion There is a need for robust and clear framing of how the concept of intersectionality is defined and understood in nursing research. There is also a need for more empirical research effectively adopting the concept of intersectionality to enhance our understanding of how health inequities operate within the field of nursing. No Patient or Public Contribution No patients, service users, caregivers or members of the public were involved in this work

Transposon mutagenesis as an approach to improved understanding of Borrelia pathogenesis and biology

Transposon insertion provides a method for near-random mutation of bacterial genomes, and has been utilized extensively for the study of bacterial pathogenesis and biology. This approach is particularly useful for organisms that are relatively refractory to genetic manipulation, including Lyme disease Borrelia. In this review, progress to date in the application of transposon mutagenesis to the study of Borrelia burgdorferi is reported. An effective Himar1-based transposon vector has been developed and used to acquire a sequence-defined library of nearly 4,500 mutants in the infectious, moderately transformable B. burgdorferi B31 derivative 5A18NP1. Analysis of these transposon mutants using signature-tagged mutagenesis (STM) and Tn-seq approaches has begun to yield valuable information regarding the genes important in the pathogenesis and biology of this organism

Genetic variation in genes of folate metabolism and neural-tube defect risk.

Contains fulltext : 50079.pdf (publisher's version ) (Open Access)Neural-tube defects (NTD) are common congenital malformations that can lead to severe disability or even death. Periconceptional supplementation with the B-vitamin folic acid has been demonstrated to prevent 50-70% of NTD cases. Since the identification of the first genetic risk factor of NTD, the C677T single-nucleotide polymorphism (SNP) in the methylenetetrahydrofolate reductase (MTHFR) gene, and the observation that elevated plasma homocysteine levels are associated with NTD, research has focused on genetic variation in genes encoding for enzymes of folate metabolism and the closely-related homocysteine metabolism. In the present review relevant SNP in genes that code for enzymes involved in folate transport and uptake, the folate cycles and homocysteine metabolism are summarised and the importance of these SNP discussed in relation to NTD risk

Interleukin-17A during Local and Systemic Staphylococcus aureus-Induced Arthritis in Mice▿

Staphylococcus aureus is one of the dominant pathogens that induce septic arthritis in immunocompromised hosts, e.g., patients suffering from rheumatoid arthritis treated with immunosuppressive drugs. S. aureus-induced arthritis leads to severe joint destruction and high mortality despite antibiotic treatment. Recently, interleukin-17A (IL-17A) has been discovered to be an important mediator of aseptic arthritis both in mice and humans, but its function in S. aureus-induced arthritis is largely unknown. Here, we investigated the role of IL-17A in host defense against arthritis following systemic and local S. aureus infection in vivo. IL-17A knockout mice and wild-type mice were inoculated systemically (intravenously) or locally (intra-articularly) with S. aureus. During systemic infection, IL-17A knockout mice lost significantly more weight than the wild-type mice did, but no differences were found in the mortality rate. The absence of IL-17A had no impact on clinical arthritis development but led to increased histopathological erosivity late during systemic S. aureus infection. Bacterial clearance in kidneys was increased in IL-17A knockout mice compared to the level in wild-type mice only 1 day after bacterial inoculation. During systemic S. aureus infection, serum IL-17F protein levels and mRNA levels in the lymph nodes were elevated in the IL-17A knockout mice compared to the level in wild-type mice. In contrast to systemic infection, the IL-17A knockout mice had increased synovitis and erosions and locally decreased clearance of bacteria 3 days after local bacterial inoculation. On the basis of these findings, we suggest that IL-17A is more important in local host defense than in systemic host defense against S. aureus-induced arthritis

The COPE Staff study : Study description and initial report regarding job satisfaction, work-life conflicts, stress, and burnout among Swedish maternal and neonatal healthcare workers during the COVID-19 pandemic

OBJECTIVE: To describe the study design of the COPE Staff cohort study on working conditions for maternal and neonatal healthcare workers (MNHCWs), and present baseline data regarding job satisfaction, work-life conflicts, stress, and burnout.METHODS: Between January and April 2021, 957 MNHCWs (administrative and medical staff) completed a baseline survey. Average levels of job satisfaction, work-life conflicts, stress, and burnout, and associations to perceived workload were assessed.RESULTS: The average levels of job satisfaction, work-life conflicts, stress, and burnout were 68.6 (95% confidence interval [CI] 64.3-72.8), 42.6 (95% CI 37.3-48.0), 42.0 (95% CI 37.7-46.3), and 1.9 (95% CI 1.6-2.2), respectively. The respondents scoring above critical values indicating clinical burnout ranged between 3% and 18%, respectively, for the four burnout sub-dimensions. Women reported significantly higher levels of stress and burnout. Younger participants had lower job satisfaction and higher levels of work-life conflicts, stress, and burnout. Higher perceived workload was significantly associated with lower job satisfaction levels and higher levels of work-life conflicts, stress, and burnout.CONCLUSIONS: Our results indicate associations between MNHCWs perceived workload and job satisfaction, work-life conflicts, stress, and burnout during the COVID-19 pandemic. Eighteen percent scored above critical values for exhaustion

Proof of concept: enthesitis and new bone formation in spondyloarthritis are driven by mechanical strain and stromal cells

Objectives: Spondyloarthritides (SpA) are characterised by both peripheral and axial arthritis. The hallmarks of peripheral SpA are the development of enthesitis, most typically of the Achilles tendon and plantar fascia, and new bone formation. This study was undertaken to unravel the mechanisms leading towards enthesitis and new bone formation in preclinical models of SpA. Results: First, we demonstrated that TNF Delta ARE mice show typical inflammatory features highly reminiscent of SpA. The first signs of inflammation were found at the entheses. Importantly, enthesitis occurred equally in the presence or absence of mature T and B cells, underscoring the importance of stromal cells. Hind limb unloading in TNF Delta ARE mice significantly suppressed inflammation of the Achilles tendon compared with weight bearing controls. Erk1/2 signalling plays a crucial role in mechanotransduction-associated inflammation. Furthermore, new bone formation is strongly promoted at entheseal sites by biomechanical stress and correlates with the degree of inflammation. Conclusions: These findings provide a formal proof of the concept that mechanical strain drives both entheseal inflammation and new bone formation in SpA