58 resultados para Generalist and specialists
Resumo:
The secondary metabolites in the roots, leaves and flowers of the common dandelion (Taraxacum officinale agg.) have been studied in detail. However, little is known about the specific constituents of the plant’s highly specialized laticifer cells. Using a combination of liquid and gas chromatography, mass spectrometry and nuclear magnetic resonance spectrometry, we identified and quantified the major secondary metabolites in the latex of different organs across different growth stages in three genotypes, and tested the activity of the metabolites against the generalist root herbivore Diabrotica balteata. We found that common dandelion latex is dominated by three classes of secondary metabolites: phenolic inositol esters (PIEs), triterpene acetates (TritAc) and the sesquiterpene lactone taraxinic acid β-d-glucopyranosyl ester (TA-G). Purification and absolute quantification revealed concentrations in the upper mg g−1 range for all compound classes with up to 6% PIEs, 5% TritAc and 7% TA-G per gram latex fresh weight. Contrary to typical secondary metabolite patterns, concentrations of all three classes increased with plant age. The highest concentrations were measured in the main root. PIE profiles differed both quantitatively and qualitatively between plant genotypes, whereas TritAc and TA-G differed only quantitatively. Metabolite concentrations were positively correlated within and between the different compound classes, indicating tight biosynthetic co-regulation. Latex metabolite extracts strongly repelled D. balteata larvae, suggesting that the latex constituents are biologically active.
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The WTO is one of the most important intergovernmental organizations in the world, yet the way in which it functions as an organization and the scope of its authority and power are still poorly understood. This comprehensively revised new edition of the acclaimed work by an outstanding team of WTO law specialists provides a complete overview of the law and practice of the WTO.
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In monocotyledonous plants, 1,4-benzoxazin-3-ones, also referred to as benzoxazinoids or hydroxamic acids, are one of the most important chemical barriers against herbivores. However, knowledge about their behavior after attack, mode of action and potential detoxification by specialized insects remains limited. We chose an innovative analytical approach to understand the role of maize 1,4-benzoxazin-3-ones in plant–insect interactions. By combining unbiased metabolomics screening and simultaneous measurements of living and digested plant tissue, we created a quantitative dynamic map of 1,4-benzoxazin-3-ones at the plant–insect interface. Hypotheses derived from this map were tested by specifically developed in vitro assays using purified 1,4-benzoxazin-3-ones and active extracts from mutant plants lacking 1,4-benzoxazin-3-ones. Our data show that maize plants possess a two-step defensive system that effectively fends off both the generalist Spodoptera littoralis and the specialist Spodoptera frugiperda. In the first step, upon insect attack, large quantities of 2-β-d-glucopyranosyloxy-4,7-dimethoxy-1,4-benzoxazin-3-one (HDMBOA-Glc) are formed. In the second step, after tissue disruption by the herbivores, highly unstable 2-hydroxy-4,7-dimethoxy-1,4-benzoxazin-3-one (HDMBOA) is released by plant-derived β-glucosidases. HDMBOA acts as a strong deterrent to both S. littoralis and S. frugiperda. Although constitutively produced 1,4-benzoxazin-3-ones such as 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) are detoxified via glycosylation by the insects, no conjugation of HDMBOA in the insect gut was found, which may explain why even the specialist S. frugiperda has not evolved immunity against this plant defense. Taken together, our results show the benefit of using a plant–insect interface approach to elucidate plant defensive processes and unravel a potent resistance mechanism in maize.
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This study explores whether the high variability of vascular plant diversity among alpine plant communities can be explained by stress and/or disturbance intensities. Species numbers of 14 alpine plant communities were sampled in the Swiss Alps. To quantify the intensity of 13 stress and 6 disturbance factors potentially controlling plant life in these communities, a survey was conducted by asking numerous specialists in alpine vegetation to assess the importance of the different factors for each community. The estimated values were combined in stress- and disturbance-indices which were compared with diversity according to the Intermediate Stress Hypothesis, the Intermediate Disturbance Hypothesis, and the Dynamic Equilibrium Model, respectively. Each of these theories explained a part of the variability in the species richness, but only the Dynamic Equilibrium Model provided a complete and consistent explanation. The last model suggests that community species richness within the alpine life zone is generally controlled by stress intensity. Disturbance and competition seem to play a secondary role by fine-tuning diversity in specific communities. As diversity is primarily limited by stress, a moderation of temperature-related stress factors, as a result of global warming, may cause a shift of the equilibrium between stress, disturbance, and competition in alpine ecosystems.
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The ecosystem services concept (ES) is becoming a cornerstone of contemporary sustainability thought. Challenges with this concept and its applications are well documented, but have not yet been systematically assessed alongside strengths and external factors that influence uptake. Such an assessment could form the basis for improving ES thinking, further embedding it into environmental decisions and management. The Young Ecosystem Services Specialists (YESS) completed a Strengths–Weaknesses–Opportunities–Threats (SWOT) analysis of ES through YESS member surveys. Strengths include the approach being interdisciplinary, and a useful communication tool. Weaknesses include an incomplete scientific basis, frameworks being inconsistently applied, and accounting for nature's intrinsic value. Opportunities include alignment with existing policies and established methodologies, and increasing environmental awareness. Threats include resistance to change, and difficulty with interdisciplinary collaboration. Consideration of SWOT themes suggested five strategic areas for developing and implementing ES. The ES concept could improve decision-making related to natural resource use, and interpretation of the complexities of human-nature interactions. It is contradictory – valued as a simple means of communicating the importance of conservation, whilst also considered an oversimplification characterised by ambiguous language. Nonetheless, given sufficient funding and political will, the ES framework could facilitate interdisciplinary research, ensuring decision-making that supports sustainable development.
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Stable coronary artery disease is the most common clinical manifestation of ischaemic heart disease and a leading cause of mortality worldwide. Myocardial revascularisation is a mainstay in the treatment of symptomatic patients or those with ischaemia-producing coronary lesions, and reduces ischaemia to a greater extent than medical treatment. Documentation of ischaemia and plaque burden is fundamental in the risk stratification of patients with stable coronary artery disease, and several invasive and non-invasive techniques are available (eg, fractional flow reserve or intravascular ultrasound) or being validated (eg, instantaneous wave-free ratio and optical coherence tomography). The use of new-generation drug-eluting stents and arterial conduits greatly improve clinical outcome in patients undergoing percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). PCI is feasible, safe, and effective in many patients with stable coronary artery disease who remain symptomatic despite medical treatment. In patients with multivessel and left main coronary artery disease, the decision between PCI or CABG is guided by the local Heart Team (team of different cardiovascular specialists, including non-invasive and invasive cardiologists, and cardiac surgeons), who carefully judge the possible benefits and risks inherent to PCI and CABG. In specific subsets, such as patients with diabetes and advanced, multivessel coronary artery disease, CABG remains the standard of care in view of improved protection against recurrent ischaemic adverse events.
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BACKGROUND Pemphigus encompasses a group of life-threatening autoimmune bullous diseases characterized by blisters and erosions of the mucous membranes and skin. Before the era of immunosuppressive treatment, the prognosis of pemphigus was almost fatal. Due to its rarity, only few prospective controlled therapeutic trials are available. OBJECTIVES For this reason, a group of European dermatologists with a long-standing interest and expertise in basic and clinical pemphigus research has sought to define diagnostic and therapeutic guidelines for the management of patients with pemphigus. RESULTS This group identified the statements of major agreement or disagreement regarding the diagnostic and therapeutic management of pemphigus. The revised final version of the pemphigus guideline was finally passed on to the European Dermatology Forum (EDF) for a final consensus with the European Academy of Dermatology and Venereology (EADV) and the European Union of Medical Specialists (UEMS).
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The World Overview of Conservation Approaches and Technologies (WOCAT) is a program of the World Association of Soil and Water Conservation (WASWC), organized as a consortium of several international institutions. The overall goal of WOCAT is to contribute to sustainable utilization of soil and water. WOCAT collects and analyzes information on soil and water conservation (SWC) technologies and approaches world-wide, and presents the collected information in computer databases and decision support systems, and in the form of handbooks, reports and maps readily accessible to SWC specialists and policy-makers world-wide. WOCAT has prepared a framework for the evaluation of soil and water conservation and has started data collection. The paper presents preliminary results with promising SWC technologies and approaches used in Eastern and Southern Africa. The first finding is that hardly any promising SWC activities could be found on common grazing lands. Analysis of the cropland shows some of the bio-physical and socioeconomic conditions under which certain SWC technologies and approaches are used, including land use types, climatic zones and land tenure, and looks at issues such as participation and costs. Furthermore, classification criteria for SWC technologies and approaches are discussed.
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Edited by Annette Kern-Stähler, Beatrix Busse, and Wietse de Boer The essays collected in The Five Senses in Medieval and Early Modern England examine the interrelationships between sense perception and secular and Christian cultures in England from the medieval into the early modern periods. They address canonical texts and writers in the fields of poetry, drama, homiletics, martyrology and early scientific writing, and they espouse methods associated with the fields of corpus linguistics, disability studies, translation studies, art history and archaeology, as well as approaches derived from traditional literary studies. Together, these papers constitute a major contribution to the growing field of sensorial research that will be of interest to historians of perception and cognition as well as to historians with more generalist interests in medieval and early modern England.
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PURPOSE As survival rates of adolescent and young adult (AYA) cancer patients increase, a growing number of AYA cancer survivors need follow-up care. However, there is little research on their preferences for follow-up care. We aimed to (1) describe AYA cancer survivors' preferences for the organization and content of follow-up care, (2) describe their preferences for different models of follow-up, and (3) investigate clinical and sociodemographic characteristics associated with preferences for the different models. METHODS AYA cancer survivors (diagnosed with cancer at age 16-25 years; ≥5 years after diagnosis) were identified through the Cancer Registry Zurich and Zug. Survivors completed a questionnaire on follow-up attendance, preferences for organizational aspects of follow-up care (what is important during follow-up, what should be included during appointments, what specialists should be involved, location), models of follow-up (telephone/questionnaire, general practitioner (GP), pediatric oncologist, medical oncologist, multidisciplinary team), and sociodemographic characteristics. Information on tumor and treatment was available through the Cancer Registry Zurich and Zug. RESULTS Of 389 contacted survivors, 160 (41.1 %) participated and 92 (57.5 %) reported still attending follow-up. Medical aspects of follow-up care were more important than general aspects (p < 0.001). Among different organizational models, follow-up by a medical oncologist was rated higher than all other models (p = 0.002). Non-attenders of follow-up rated GP-led follow-up significantly higher than attenders (p = 0.001). CONCLUSION Swiss AYA cancer survivors valued medical content of follow-up and showed a preference for medical oncologist-led follow-up. Implementation of different models of follow-up care might improve accessibility and attendance among AYA cancer survivors.
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Biosecurity is crucial for safeguarding livestock from infectious diseases. Despite the plethora of biosecurity recommendations, published scientific evidence on the effectiveness of individual biosecurity measures is limited. The objective of this study was to assess the perception of Swiss experts about the effectiveness and importance of individual on-farm biosecurity measures for cattle and swine farms (31 and 30 measures, respectively). Using a modified Delphi method, 16 Swiss livestock disease specialists (8 for each species) were interviewed. The experts were asked to rank biosecurity measures that were written on cards, by allocating a score from 0 (lowest) to 5 (highest). Experts ranked biosecurity measures based on their importance related to Swiss legislation, feasibility, as well as the effort required for implementation and the benefit of each biosecurity measure. The experts also ranked biosecurity measures based on their effectiveness in preventing an infectious agent from entering and spreading on a farm, solely based on transmission characteristics of specific pathogens. The pathogens considered by cattle experts were those causing Bluetongue (BT), Bovine Viral Diarrhea (BVD), Foot and Mouth Disease (FMD) and Infectious Bovine Rhinotracheitis (IBR). Swine experts expressed their opinion on the pathogens causing African Swine Fever (ASF), Enzootic Pneumonia (EP), Porcine Reproductive and Respiratory Syndrome (PRRS), as well as FMD. For cattle farms, biosecurity measures that improve disease awareness of farmers were ranked as both most important and most effective. For swine farms, the most important and effective measures identified were those related to animal movements. Among all single measures evaluated, education of farmers was perceived by the experts to be the most important and effective for protecting both Swiss cattle and swine farms from disease. The findings of this study provide an important basis for recommendation to farmers and policy makers.
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Plant quality is one of the main factors influencing the fitness of phytophagous insects. Plant quality can vary not only among genotypes of the same host plant species, but also relative to the insect sex or its life stage. In the present study, the performance of larvae and adults of the pollen beetle (Meligethes aeneus F., Coleoptera: Nitidulidae), a major insect pest of oilseed rape crops, is compared on six genotypes of oilseed rape (Brassica napus). All of the traits that are measured vary among genotypes, and comprise larval developmental duration, life span of unfed emerging adults and survival time of field-sampled adults fed with pollen from the different genotypes. No correlation is found between insect performance and quantity of food available, showing that the quality of the food (i.e. pollen) is the fitness determinant for this insect species. Additionally, the performance of larvae and adults is also not correlated despite use of the same plant genotypes, suggesting that the determinants of pollen quality differ at least partially between both life stages. It is hypothesized that this may be a result of extensive differences in diet breadth between the life stages: larvae are specialists of brassicaceous plants, whereas adults are generalists. Finally, it is suggested that the manipulation of plant quality to increase pollen beetle development time may comprise a valuable strategy for favouring biological control by natural enemies of this pest; for example, as a result of extending the vulnerability window of larvae to attack by parasitoids.
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For industry people, journalists, activists, lawyers, diplomats, national legislators, and students of the World Trade Organization's Agreement on Trade-related Aspects of Intellectual Property (TRIPS) has awesome proportions. These are magnified by the fact that these groups lack detailed knowledge of either IP as such or international trade law. IP involves a broad spread of academic specialists and practitioners covering heterogeneous complex regimes of patents, copyright, trade marks, design, undisclosed information (trade secrets), and geographical indications. IP, and subsequently TRIPS, is the meeting point of many stakeholders and actors with conflicting interests spread between market aspirations and concepts of public good. In a globalized economy with deep interconnections across sectors, national borders challenged by inchoate technologies, dynamic social stakeholders, and converging technologies, it is fundamental to have a clear and uncluttered understanding of this Agreement. That is because TRIPS impinges on trade in many products of daily life, from pharmaceuticals to entertainment electronics, as well as mitigating and adaptive technologies for climate change and sustainable development. Given its saliency and ubiquity in economic life, TRIPS has often generated misunderstanding and controversy in the public debate. To complicate matters, technical and legal issues at the interface of technology, IP, and trade remain the province of an eclectic band of specialists and on the radar of interest groups with goals on opposite poles.