Canadian vegetation response to climate and projected climatic change

The equilibrium response of Canadian vegetation to climate and climatic change was modeled at three organizational levels of the vegetation mosaic. The climatic parameters used as model drivers (i.e., snowpack, degree-days, minimum temperature, soil moisture deficit, and actual evapotranspiration) are components of climate that physiologically constrain the distribution of dominant plant life-forms and species in Canada. The rule-based Canadian Climate-Vegetation Model (CCVM) predicts the response of vegetation formations to climate. The rules define climatic thresholds across which one formation gives way to another. The CCVM simulation for current climatic conditions is more accurate and detailed than those of other equilibrium models. A series of ecological response surfaces predict the probability of dominance for eight boreal tree species in Canada with a high degree of success. Variation in the probability of dominance is related to the species' individualistic response to climatic constraints within different airmass regions. A boreal forest-type classification based on the probabilities of dominance shows a high degree of geographic correspondence with observed forest-types. Under two doubled-CO2 climatic scenarios, CCVM predicts a reduction in arctic tundra and subarctic woodland, a northward shift in the distribution of boreal evergreen forest and an expansion of temperate forest, boreal summergreen woodland, and two prairie formations. The response surfaces predict significant changes in species dominance under both climatic scenarios. Species exhibit an individualistic response to climatic change and respond differently under the different scenarios. All but one of the boreal forest-types derived from future probabilities of dominance are analogous to extant forest-types, but fewer types are distinguished. Geographic correspondence in the boreal forest regions simulated by the rule-based and response surface models under both the current and projected climates provides a link between the results of the two modelling approaches. There are several constraints on the realism of the vegetation scenarios in this study, but they are arguably the most reliable and comprehensive predictions for Canada to date given the direct relationship between the climatic parameters and the distribution of vegetation and the simulation of vegetation at three different organizational levels

Long-term survival in people with transthyretin amyloid cardiomyopathy who took tafamidis: A Plain Language Summary

WHAT IS THIS PLAIN LANGUAGE SUMMARY ABOUT?: This summary presents the results from an ongoing, long-term extension study that followed an earlier study called ATTR-ACT. People who took part in this extension study and ATTR-ACT have a type of heart disease known as transthyretin amyloid cardiomyopathy (ATTR-CM for short), which causes heart failure and death. In ATTR-ACT, people took either a medicine called tafamidis or a placebo (a pill that looks like the study drug but does not contain any active ingredients) for up to 2½ years. So far, in the long-term extension study, people have continued taking tafamidis, or switched from taking a placebo to tafamidis, for another 2½ years. Researchers looked at how many people died in ATTR-ACT and the extension study. The long-term extension study is expected to end in 2027, so these are interim (not final) results. WHAT DID RESEARCHERS FIND OUT?: In the extension study of ATTR-ACT, the risk of dying was lower in people who took tafamidis continuously throughout ATTR-ACT and the extension study than in people who took placebo in ATTR-ACT and switched to tafamidis in the extension study. WHAT DO THE RESULTS MEAN?: Taking tafamidis increases how long people with ATTR-CM live. People with ATTR-CM who take tafamidis early and continuously are more likely to live longer than those who do not. These results highlight the importance of early detection and treatment in people with ATTR-CM. Clinical Trial Registration: NCT01994889 (ClinicalTrials.gov) Clinical Trial Registration: NCT02791230 (ClinicalTrials.gov)

Managing Bay and Estuarine Ecosystems for Multiple Services

Abstract Managers are moving from a model of managing individual sectors, human activities, or ecosystem services to an ecosystem-based management (EBM) approach which attempts to balance the range of services provided by ecosystems. Applying EBM is often difficult due to inherent tradeoffs in managing for different services. This challenge particularly holds for estuarine systems, which have been heavily altered in most regions and are often subject to intense management interventions. Estuarine managers can often choose among a range of management tactics to enhance a particular service; although some management actions will result in strong tradeoffs, others may enhance multiple services simultaneously. Management of estuarine ecosystems could be improved by distinguishing between optimal management actions for enhancing multiple services and those that have severe tradeoffs. This requires a framework that evaluates tradeoff scenarios and identifies management actions likely to benefit multiple services. We created a management action-services matrix as a first step towards assessing tradeoffs and providing managers with a DOI 10.1007/s12237-013-9602-7 decision support tool. We found that management actions that restored or enhanced natural vegetation (e.g., salt marsh and mangroves) and some shellfish (particularly oysters and oyster reef habitat) benefited multiple services. In contrast, management actions such as desalination, salt pond creation, sand mining, and large container shipping had large net negative effects on several of the other services considered in the matrix. Our framework provides resource managers a simple way to inform EBM decisions and can also be used as a first step in more sophisticated approaches that model service delivery

Simulating social-ecological systems: the Island Digital Ecosystem Avatars (IDEA) consortium

Abstract Systems biology promises to revolutionize medicine, yet human wellbeing is also inherently linked to healthy societies and environments (sustainability). The IDEA Consortium is a systems ecology open science initiative to conduct the basic scientific research needed to build use-oriented simulations (avatars) of entire social-ecological systems. Islands are the most scientifically tractable places for these studies and we begin with one of the best known: Moorea, French Polynesia. The Moorea IDEA will be a sustainability simulator modeling links and feedbacks between climate, environment, biodiversity, and human activities across a coupled marine-terrestrial landscape. As a model system, the resulting knowledge and tools will improve our ability to predict human and natural change on Moorea and elsewhere at scales relevant to management/conservation actions

Genomic investigations of unexplained acute hepatitis in children

Since its first identification in Scotland, over 1,000 cases of unexplained paediatric hepatitis in children have been reported worldwide, including 278 cases in the UK1. Here we report an investigation of 38 cases, 66 age-matched immunocompetent controls and 21 immunocompromised comparator participants, using a combination of genomic, transcriptomic, proteomic and immunohistochemical methods. We detected high levels of adeno-associated virus 2 (AAV2) DNA in the liver, blood, plasma or stool from 27 of 28 cases. We found low levels of adenovirus (HAdV) and human herpesvirus 6B (HHV-6B) in 23 of 31 and 16 of 23, respectively, of the cases tested. By contrast, AAV2 was infrequently detected and at low titre in the blood or the liver from control children with HAdV, even when profoundly immunosuppressed. AAV2, HAdV and HHV-6 phylogeny excluded the emergence of novel strains in cases. Histological analyses of explanted livers showed enrichment for T cells and B lineage cells. Proteomic comparison of liver tissue from cases and healthy controls identified increased expression of HLA class 2, immunoglobulin variable regions and complement proteins. HAdV and AAV2 proteins were not detected in the livers. Instead, we identified AAV2 DNA complexes reflecting both HAdV-mediated and HHV-6B-mediated replication. We hypothesize that high levels of abnormal AAV2 replication products aided by HAdV and, in severe cases, HHV-6B may have triggered immune-mediated hepatic disease in genetically and immunologically predisposed children

The Response of Vegetation Distribution, Ecosystem Productivity, and Fire in California to Future Climate Scenarios Simulated by the MC1 Dynamic Vegetation Model

The objective of this study was to dynamically simulate the response of vegetation distribution, carbon, and fire to three scenarios of future climate change for California using the MAPSSCENTURY (MC1) dynamic general vegetation model. Under all three scenarios, Alpine/Subalpine Forest cover declined with increased growing season length and warmth, and increases in the productivity of evergreen hardwoods with increased temperature led to the displacement of Evergreen Conifer Forest by Mixed Evergreen Forest. The simulated responses to changes in precipitation were complex, involving not only the effect on vegetation productivity, but also changes in tree-grass competition mediated by fire. Grassland expanded, largely at the expense of Woodland and Shrubland, even under the relatively cool and moist PCM-A2 climate scenario where increased woody plant production was offset by increased wildfire. Increases in net primary productivity (NPP) under the PCM-A2 climate scenario contributed to a simulated carbon sink of about 321 teragrams (353.8 million tons) for California by the end of the century. Declines in net primary productivity (NPP) under the two warmer and drier GFDL climate scenarios, most evident under the GFDL-A2 scenario, contributed to a net loss of carbon ranging from about 76 to 129 Tg (83.8 to 142.2 million tons) by the end of the century. Total annual area burned in California increased under all three scenarios, ranging from 9%–15% above the historical norm by the end of the century. Regional variation in the simulated changes in area burned was largely a product of changes in vegetation productivity and shifts in the relative dominance of woody plants and grasses. Annual biomass consumption by fire by the end of the century was about 18% greater than the historical norm under the more productive PCM-A2 scenario. Under the warmer and drier GFDL scenarios, simulated biomass consumption was also greater than normal for the first few decades of the century as droughtstressed woodlands and shrublands burned and were converted to grassland. After this transitional period, lower than normal NPP produced less fuel, and biomass consumed was at, or below, the historical norm by the end of the century under the GFDL scenarios. Considerable uncertainty exists with respect to regional-scale impacts of global warming on the natural ecosystem of California. Much of this uncertainty resides in the differences among different GCM climate scenarios and assumed trajectories of future greenhouse gas emissions as illustrated in this study. In addition, ecosystem models and their response to projected climate change can always be improved through careful testing and enhancement of model processes. The direct effects of increasing CO2 on ecosystem productivity and water use, and assumptions regarding fire suppression and the availability of ignition sources, were identified as sources of uncertainty to be addressed through further model testing and development