Landscape features exist at multiple spatial and temporal scales, and these naturally affect spatial genetic structure and our ability to make inferences about gene flow. This article discusses how ...decisions about sampling of genotypes (including choices about analytical methods and genetic markers) should be driven by the scale of spatial genetic structure, the time frame that landscape features have existed in their current state, and all aspects of a species' life history. Researchers should use caution when making inferences about gene flow, especially when the spatial extent of the study area is limited. The scale of sampling of the landscape introduces different features that may affect gene flow. Sampling grain should be smaller than the average home-range size or dispersal distance of the study organism and, for raster data, existing research suggests that simplifying the thematic resolution into discrete classes may result in low power to detect effects on gene flow. Therefore, the methods used to characterize the landscape between sampling sites may be a primary determinant for the spatial scale at which analytical results are applicable, and the use of only one sampling scale for a particular statistical method may lead researchers to overlook important factors affecting gene flow. The particular analytical technique used to correlate landscape data and genetic data may also influence results; common landscape-genetic methods may not be suitable for all study systems, particularly when the rate of landscape change is faster than can be resolved by common molecular markers.
ACC/AHA Task Force Members Jeffrey L. Anderson, MD, FACC, FAHA, Chair, Jonathan L. Halperin, MD, FACC, FAHA, Chair-Elect, Nancy M. Albert, PhD, CCNS, CCRN, FAHA, Biykem Bozkurt, MD, PhD, FACC, FAHA, ...Ralph G. Brindis, MD, MPH, MACC, Mark A. Creager, MD, FACC, FAHA§§Task Force member during the writing effort., Lesley H. Curtis, PhD, FAHA, David DeMets, PhD, Robert A. Guyton, MD, FACC§§, Judith S. Hochman, MD, FACC, FAHA, Richard J. Kovacs, MD, FACC, FAHA, E. Magnus Ohman, MD, FACC, Susan J. Pressler, PhD, RN, FAHA, Frank W. Sellke, MD, FACC, FAHA, Win-Kuang Shen, MD, FACC, FAHA, William G. Stevenson, MD, FACC, FAHA§§, Clyde W. Yancy, MD, FACC, FAHA§§ Table of Contents Preamble... An organized and directed approach to a thorough review of evidence has resulted in the production of clinical practice guidelines that assist clinicians in selecting the best management strategy for an individual patient. ...clinical practice guidelines can provide a foundation for other applications, such as performance measures, appropriate use criteria, and both quality improvement and clinical decision support tools. ...in view of the increasing number of comparative effectiveness studies, comparator verbs and suggested phrases for writing recommendations for the comparative effectiveness of one treatment or strategy versus another are included for COR I and IIa, LOE A or B only.\n Charney Division of Cardiology; Associate Director, Health Care Center None None None None None None Craig R. Smith Content Reviewer Columbia University College of Physicians and Surgeons--Professor of Surgery; Chair, Department of Surgery; New York-Presbyterian Hospital/Columbia University Medical Center--Surgeon-in-Chief None None None Edwards Lifesciences--PI None None Ruth H. Strasser Content Reviewer--AIG Heart Centre,University Hospital, University of Technology, Dresden--Professor, Director, and Chair, Internal Medicine and Cardiology Clinic; Medical Director, Heart Centre None None None None Abbottdagger AstraZenecadagger Bayerdagger Biosensorsdagger Pfizerdagger None Rakesh Suri Content Reviewer Mayo Clinic--Associate Professor of Surgery None None None None Edwards Lifesciencesdagger Sorindagger St. Jude Medicaldagger None Vinod Thourani Content Reviewer--Surgeon Council Emory University Edward Lifesciences Sorin St. Jude Medical None Apica Cardiovasculardagger Maquet None None Alec Vahanian Content Reviewer Hospital Bichat--Department de Cardiologie Abbott Vascular Edwards Lifesciences Medtronic St. Jude Medical Valtech None None None None None Andrew Wang Content Reviewer Duke University Medical Center--Professor of Medicine None None None Abbott Vascularlow * Edwards Lifescienceslow * None Defendant, Sudden death, 2012 * This table represents the relationships of reviewers with industry and other entities that were disclosed at the time of peer review and determined to be relevant to this document. Names are listed in alphabetical order within each category of review.According to the ACC/AHA, a person has a relevant relationship IF: a) The relationship or interest relates to the same or similar subject matter, intellectual property or asset, topic, or issue addressed in the document; or b) The company/entity (with whom the relationship exists) makes a drug, drug class, or device addressed in the document, or makes a competing drug or device addressed in the document; or c) The person or a member of the person's household, has a reasonable potential for financial, professional or other personal gain or loss as a result of the issues/content addressed in the document.AATS indicates American Association for Thoracic Surgery; ACC, American College of Cardiology; AHA, American Heart Association; AIG, Association of International Governors; ASE, American Society of Echocardiography; DSMB, Data and Safety Monitoring Board; MRI, magnetic resonance imaging; NIH, National Institutes of Health; NYU, New York University; PARTNERS, Placement Of Aortic Transcatheter Valves; PI, Principal Investigator; SCA, Society of Cardiovascular Anesthesiologists; SCAI, Society for Cardiovascular Angiography and Interventions; STS, Society of Thoracic Surgeons; and VA, Veterans Affairs.
Abstract Background The classification of aortic dissection into acute (<14 days from symptom onset) versus chronic (≥14 days) is based on survival estimates of patients treated decades before modern ...diagnostic and treatment modalities were available. A new classification of aortic dissection in the current era may provide clinicians with a more precise method of characterizing the interaction of time, dissection location, and treatment type with survival. Methods We developed separate Kaplan-Meier survival curves for Type A and Type B aortic dissection using data from the International Registry of Aortic Dissection (IRAD). Daily survival was stratified based on type of therapy provided: medical therapy alone (medical), nonsurgical intervention plus medical therapy (endovascular), and open surgery plus medical therapy (surgical). The log-rank statistic was used to compare the survival curves of each management type within Type A and Type B aortic dissection. Results There were 1815 patients included, 67.3% male with mean age 62.0 ± 14.2 years. When survival curves were constructed, 4 distinct time periods were noted: hyperacute (symptom onset to 24 hours), acute (2-7 days), subacute (8-30 days), and chronic (>30 days). Overall survival was progressively lower through the 4 time periods. Conclusions This IRAD classification system can provide clinicians with a more robust method of characterizing survival after aortic dissection over time than previous methods. This system will be useful for treating patients, counseling patients and families, and studying new diagnostic and treatment methods.
Population genetics theory is primarily based on mathematical models in which spatial complexity and temporal variability are largely ignored. In contrast, the field of landscape genetics expressly ...focuses on how population genetic processes are affected by complex spatial and temporal environmental heterogeneity. It is spatially explicit and relates patterns to processes by combining complex and realistic life histories, behaviours, landscape features and genetic data. Central to landscape genetics is the connection of spatial patterns of genetic variation to the usually highly stochastic space-time processes that create them over both historical and contemporary time periods. The field should benefit from a shift to computer simulation approaches, which enable incorporation of demographic and environmental stochasticity. A key role of simulations is to show how demographic processes such as dispersal or reproduction interact with landscape features to affect probability of site occupancy, population size, and gene flow, which in turn determine spatial genetic structure. Simulations could also be used to compare various statistical methods and determine which have correct type I error or the highest statistical power to correctly identify spatio-temporal and environmental effects. Simulations may also help in evaluating how specific spatial metrics may be used to project future genetic trends. This article summarizes some of the fundamental aspects of spatial-temporal population genetic processes. It discusses the potential use of simulations to determine how various spatial metrics can be rigorously employed to identify features of interest, including contrasting locus-specific spatial patterns due to micro-scale environmental selection.
Abstract
Time is running out to limit further devastating losses of biodiversity and nature's contributions to humans. Addressing this crisis requires accurate predictions about which species and ...ecosystems are most at risk to ensure efficient use of limited conservation and management resources. We review existing biodiversity projection models and discover problematic gaps. Current models usually cannot easily be reconfigured for other species or systems, omit key biological processes, and cannot accommodate feedbacks with Earth system dynamics. To fill these gaps, we envision an adaptable, accessible, and universal biodiversity modeling platform that can project essential biodiversity variables, explore the implications of divergent socioeconomic scenarios, and compare conservation and management strategies. We design a roadmap for implementing this vision and demonstrate that building this biodiversity forecasting platform is possible and practical.
Abstract
High-order mobile predators are generally thought to increase ecosystem stability and resilience to natural perturbations. In many insect food-webs, higher trophic positions are occupied by ...parasitoids, which are themselves hosts for hyperparasitoids that can reduce primary parasitoids’ efficiency in controlling insect pests. Hyperparasitoids can thus provide ecosystem disservices by facilitating pest outbreaks, or ecosystem services by stabilizing food web fluctuations over longer time periods. To better understand how hyperparasitism affects multitrophic forest systems, we examined for the first time spatial variations in hyperparasitism associated with the spruce budworm. We examined 2 common primary parasitoids of the spruce budworm during outbreaks (Apanteles fumiferanae and Glypta fumiferanae), and estimated their true and pseudohyperparasitism rates in 2014–2015 from 28 locations across a latitudinal gradient (over 450 km) of forest genus diversity. Hyperparasitoid cryptic diversity was also quantified using DNA-barcoding. We found that A. fumiferanae and G. fumiferanae share at least 2 of 5 common hyperparasitoid species, confirming the connected nature of the spruce budworm-parasitoid food web. Moreover, hyperparasitism is modulated by spatial context as we observed a positive correlation between forest genus diversity and hyperparasitism for A. fumiferanae, but not for G. fumiferanae. Further monitoring hyperparasitism holds significant potential to provide new insights into how forest composition affects multitrophic interactions and spatio-temporal outbreak dynamics.
Abstract Since the publication of the 2012 guidelines new literature has emerged to inform decision-making. The 2016 guidelines primary panel selected a number of clinically relevant questions and ...has produced updated recommendations, on the basis of important new findings. In subjects with clinical atherosclerosis, abdominal aortic aneurysm, most subjects with diabetes or chronic kidney disease, and those with low-density lipoprotein cholesterol ≥ 5 mmol/L, statin therapy is recommended. For all others, there is an emphasis on risk assessment linked to lipid determination to optimize decision-making. We have recommended nonfasting lipid determination as a suitable alternative to fasting levels. Risk assessment and lipid determination should be considered in individuals older than 40 years of age or in those at increased risk regardless of age. Pharmacotherapy is generally not indicated for those at low Framingham Risk Score (FRS; <10%). A wider range of patients are now eligible for statin therapy in the FRS intermediate risk category (10%-19%) and in those with a high FRS (> 20%). Despite the controversy, we continue to advocate for low-density lipoprotein cholesterol targets for subjects who start therapy. Detailed recommendations are also presented for health behaviour modification that is indicated in all subjects. Finally, recommendation for the use of nonstatin medications is provided. Shared decision-making is vital because there are many areas in which clinical trials do not fully inform practice. The guidelines are meant to be a platform for meaningful conversation between patient and care provider so that individual decisions can be made for risk screening, assessment, and treatment.
Context
Forest landscapes worldwide are shaped by abiotic drivers such as fire, windstorms, and drought, but also by biotic drivers like insect pests and pathogens. Although the effects of such ...drivers on forest dynamics have been studied extensively, knowledge of the interactions between insect pests and other drivers of change is still coarse and fragmented. Indeed, new invasive insect species and global change may lead to novel interactions and produce impacts on forest ecosystems never before experienced.
Objectives
We aimed to review the mechanisms underlying interactions between insect pest outbreaks and other forest disturbances, identify interactions emerging from current disturbance dynamics, and highlight the role of simulation models in exploring these interactions in a dynamic, mechanistic, and spatially explicit manner.
Methods
We reviewed the state of the science regarding interactions between insect pests and other forest disturbances, collecting a set of 216 scientific articles.
Results
Most studies focused on the interaction between insect outbreaks and fire, whereas interactions between insect pests and drought, forest management or forest diseases received much less attention. Although we identified some trends in how interactions were manifested, interactions were not more commonly found at particular spatial or temporal scales. Relatively few studies used simulation models to explore interactions between disturbances and very few studies explored multiple interactions.
Conclusions
Interactions between pests and other forest disturbances play critical roles in driving forest dynamics. The effects of these interactions are likely to increase in the face of continuing global change.
Context
Dispersal has a key role in the population dynamics of outbreaking species such as the spruce budworm (
Choristoneura fumiferana
) as it can synchronize the demography of distant populations ...and favor the transition from endemic to epidemic states. However, we know very little about how landscape structure influences dispersal in such systems while such knowledge is essential for better forecasting of spatially synchronous population dynamics and to guide management strategies.
Objectives
We aimed to characterize the spatial environmental determinants of spruce budworm dispersal to determine how these features affect outbreak spread in Quebec (Canada). We then apply our findings to predict expected future landscape connectivity and explore its potential consequences on future outbreaks.
Methods
We used a machine-learning landscape genetics approach on 447 larvae covering most of the outbreak area and genotyped at 3562 SNP loci to identify the main variables affecting connectivity.
Results
We found that the connectivity between outbreak populations was driven by the combination of precipitation and host cover. Our forecasting suggests that between the current and next outbreaks, connectivity may increase between Ontario and Quebec, and might decrease in the eastern part, which could have the effect of limiting outbreak spread from Ontario and Quebec to the eastern provinces.
Conclusions
Although we did not identify any discrete barriers, low connectivity areas might constrain dispersal in the current and future outbreaks and should in turn, be intensively monitored. However, continued sampling as the outbreak progresses is needed to confirm the temporal stability of the observed patterns.
Identifying adaptive loci is important to understand the evolutionary potential of species undergoing range expansion. However, in expanding populations, spatial demographic processes such as allele ...surfing can create spatial patterns of neutral genetic variation that appear similar to those generated through adaptive processes. As a result, the false discovery rate of adaptive loci may be inflated in landscape genomic analyses. Here, we take a simulation modelling approach to investigate how range expansion affects our ability to correctly distinguish between neutral and adaptive genetic variation, using the mountain pine beetle outbreak system as a motivating example. We simulated the demographic and population genetic dynamics of populations undergoing range expansion using an individual-based genetic model CDMetaPOP. We investigated how the false discovery rate of adaptive loci is affected by (i) dispersal capacity, (ii) timing of sampling, and (iii) the strength of selection on an adaptive reference locus. We found that a combination of weak dispersal, weak selection, and early sampling presents the greatest risk of misidentifying loci under selection. Expanding populations present unique challenges to the reliable identification of adaptive loci. We demonstrate that there is a need for further methodological development to account for directional demographic processes in landscape genomics.
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